Science.gov

Sample records for achieving nuclear fusion

  1. Controlled Nuclear Fusion.

    ERIC Educational Resources Information Center

    Glasstone, Samuel

    This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

  2. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

    Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

  3. Nuclear Fusion prize laudation Nuclear Fusion prize laudation

    NASA Astrophysics Data System (ADS)

    Burkart, W.

    2011-01-01

    Clean energy in abundance will be of critical importance to the pursuit of world peace and development. As part of the IAEA's activities to facilitate the dissemination of fusion related science and technology, the journal Nuclear Fusion is intended to contribute to the realization of such energy from fusion. In 2010, we celebrated the 50th anniversary of the IAEA journal. The excellence of research published in the journal is attested to by its high citation index. The IAEA recognizes excellence by means of an annual prize awarded to the authors of papers judged to have made the greatest impact. On the occasion of the 2010 IAEA Fusion Energy Conference in Daejeon, Republic of Korea at the welcome dinner hosted by the city of Daejeon, we celebrated the achievements of the 2009 and 2010 Nuclear Fusion prize winners. Steve Sabbagh, from the Department of Applied Physics and Applied Mathematics, Columbia University, New York is the winner of the 2009 award for his paper: 'Resistive wall stabilized operation in rotating high beta NSTX plasmas' [1]. This is a landmark paper which reports record parameters of beta in a large spherical torus plasma and presents a thorough investigation of the physics of resistive wall mode (RWM) instability. The paper makes a significant contribution to the critical topic of RWM stabilization. John Rice, from the Plasma Science and Fusion Center, MIT, Cambridge is the winner of the 2010 award for his paper: 'Inter-machine comparison of intrinsic toroidal rotation in tokamaks' [2]. The 2010 award is for a seminal paper that analyzes results across a range of machines in order to develop a universal scaling that can be used to predict intrinsic rotation. This paper has already triggered a wealth of experimental and theoretical work. I congratulate both authors and their colleagues on these exceptional papers. W. Burkart Deputy Director General Department of Nuclear Sciences and Applications International Atomic Energy Agency, Vienna

  4. Cell fusion and nuclear fusion in plants.

    PubMed

    Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

    2016-12-01

    Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall.

  5. Cold nuclear fusion

    NASA Astrophysics Data System (ADS)

    Tsyganov, E. N.; Bavizhev, M. D.; Buryakov, M. G.; Dabagov, S. B.; Golovatyuk, V. M.; Lobastov, S. P.

    2015-07-01

    If target deuterium atoms were implanted in a metal crystal in accelerator experiments, a sharp increase in the probability of DD-fusion reaction was clearly observed when compared with the reaction's theoretical value. The electronic screening potential, which for a collision of free deuterium atoms is about 27 eV, reached 300-700 eV in the case of the DD-fusion in metallic crystals. These data leads to the conclusion that a ban must exist for deuterium atoms to be in the ground state 1s in a niche filled with free conduction electrons. At the same time, the state 2p whose energy level is only 10 eV above that of state 1s is allowed in these conditions. With anisotropy of 2p, 3p or above orbitals, their spatial positions are strictly determined in the lattice coordinate system. When filling out the same potential niches with two deuterium atoms in the states 2p, 3p or higher, the nuclei of these atoms can be permanently positioned without creating much Coulomb repulsion at a very short distance from each other. In this case, the transparency of the potential barrier increases dramatically compared to the ground state 1s for these atoms. The probability of the deuterium nuclei penetrating the Coulomb barrier by zero quantum vibration of the DD-system also increases dramatically. The so-called cold nuclear DD-fusion for a number of years was registered in many experiments, however, was still rejected by mainstream science for allegedly having no consistent scientific explanation. Finally, it received the validation. Below, we outline the concept of this explanation and give the necessary calculations. This paper also considers the further destiny of the formed intermediate state of 4He∗.

  6. Nuclear Fusion Award 2009 speech Nuclear Fusion Award 2009 speech

    NASA Astrophysics Data System (ADS)

    Sabbagh, Steven Anthony

    2011-01-01

    of Dr Todd Evans, another significant mentor of mine, as winner of this prestigious award? Then, it happened. The paper covers several key topics related to high beta tokamak physics. For me, the greatest satisfaction in receiving this award is because it was the first Nuclear Fusion Award to recognize research on the National Spherical Torus Experiment (NSTX) located at the Princeton Plasma Physics Laboratory. The achievement of record stability parameters in a mega-Ampere class spherical torus (ST) device reported in the paper represents a multi-year effort, contributed to by the entire research team. Research to maintain such plasmas for an indefinite period continues today. Understanding RWM stabilization physics is crucial for this goal, and leveraging the high beta ST operating space uniquely tests theory for application to future STs and to tokamaks in general, including advanced operational scenarios of ITER. For instance, the RWM was found to have significant amplitude in components with the toroidal mode number greater than unity. This has important implications for general active RWM control. Evidence that the RWM passive stabilization physics and marginal stability criterion are indeed more complex than originally thought was shown in this paper. Present work shows the greater complexity has a direct impact on how we should extrapolate RWM stabilization to future devices. The paper also reported the qualitative observation of neoclassical toroidal viscosity (NTV), followed by a companion paper by our group in 2006 reporting the quantitative observation of this effect and comparison to theory. The physics of this interesting and important phenomenon was introduced to me by Professor J. Callen (who has given an overview talk at this conference including this subject) and Professor Kerchung Shaing of the University of Wisconsin, to whom I am quite indebted. The paper also reported the first measurement of resonant field amplification at high beta in the NSTX

  7. Introduction to Nuclear Fusion Power and the Design of Fusion Reactors. An Issue-Oriented Module.

    ERIC Educational Resources Information Center

    Fillo, J. A.

    This three-part module focuses on the principles of nuclear fusion and on the likely nature and components of a controlled-fusion power reactor. The physical conditions for a net energy release from fusion and two approaches (magnetic and inertial confinement) which are being developed to achieve this goal are described. Safety issues associated…

  8. Nuclear Fusion Award 2010 speech Nuclear Fusion Award 2010 speech

    NASA Astrophysics Data System (ADS)

    Rice, John

    2011-01-01

    Following the suggestion of Earl Marmar in 1995, I installed a compact von Hamos type x-ray spectrometer (originally built with Elisabeth Rachlew and Jan Kallne) on a tangentially viewing port on the Alcator C-Mod tokamak. The spectrometer views the plasma through a 2 cm diameter hole, and is tuned to H-like argon, suitable for passive measurement of the core toroidal rotation velocity from the Doppler shift. It soon became evident that the rotation in Ohmic L-mode discharges, while for the most part directed counter-current, depends in a very complicated fashion on plasma parameters, notably the electron density, current and magnetic configuration. The rotation can even flip sign for almost no apparent reason! In Ohmic and ion cyclotron range of frequencies (ICRF) heated H-mode plasmas the rotation is in the co-current direction and has a relatively simple dependence on plasma parameters, proportional to the stored energy normalized to the current. Rotation velocities as high as 130 km s-1 have been observed without external momentum input. In dimensionless terms this intrinsic (or spontaneous rotation) depends on the normalized plasma pressure. The association of toroidal rotation with plasma pressure in ICRF H-modes was first observed by Lars-Goran Eriksson in JET discharges. Similar results were subsequently reported for Tore Supra enhanced confinement plasmas. In the early 2000s concerns began to surface about the lack of substantial neutral beam driven rotation in ITER, and intrinsic rotation became a topic of interest in the ITPA Transport Group. Through that connection, similar observations from DIII-D, TCV and JT-60U were added to the growing list. A database of intrinsic rotation observations was assembled with the goal of extrapolating to the expected values for ITER. Both dimensional and dimensionless scalings were developed and formed the backbone of the 2007 Nuclear Fusion paper. I gratefully acknowledge the important contributions to this paper from

  9. Fusion Nuclear Science Pathways Assessment

    SciTech Connect

    C.E. Kessel, et. al.

    2012-02-23

    With the strong commitment of the US to the success of the ITER burning plasma mission, and the project overall, it is prudent to consider how to take the most advantage of this investment. The production of energy from fusion has been a long sought goal, and the subject of several programmatic investigations and time line proposals [1]. The nuclear aspects of fusion research have largely been avoided experimentally for practical reasons, resulting in a strong emphasis on plasma science. Meanwhile, ITER has brought into focus how the interface between the plasma and engineering/technology, presents the most challenging problems for design. In fact, this situation is becoming the rule and no longer the exception. ITER will demonstrate the deposition of 0.5 GW of neutron heating to the blanket, deliver a heat load of 10-20 MW/m2 or more on the divertor, inject 50-100 MW of heating power to the plasma, all at the expected size scale of a power plant. However, in spite of this, and a number of other technologies relevant power plant, ITER will provide a low neutron exposure compared to the levels expected to a fusion power plant, and will purchase its tritium entirely from world reserves accumulated from decades of CANDU reactor operations. Such a decision for ITER is technically well founded, allowing the use of conventional materials and water coolant, avoiding the thick tritium breeding blankets required for tritium self-sufficiency, and allowing the concentration on burning plasma and plasma-engineering interface issues. The neutron fluence experienced in ITER over its entire lifetime will be ~ 0.3 MW-yr/m2, while a fusion power plant is expected to experience 120-180 MW-yr/m2 over its lifetime. ITER utilizes shielding blanket modules, with no tritium breeding, except in test blanket modules (TBM) located in 3 ports on the midplane [2], which will provide early tests of the fusion nuclear environment with very low tritium production (a few g per year).

  10. Nuclear data requirements for fusion reactor nucleonics

    SciTech Connect

    Bhat, M.R.; Abdou, M.A.

    1980-01-01

    Nuclear data requirements for fusion reactor nucleonics are reviewed and the present status of data are assessed. The discussion is divided into broad categories dealing with data for Fusion Materials Irradiation Test Facility (FMIT), D-T Fusion Reactors, Alternate Fuel Cycles and the Evaluated Data Files that are available or would be available in the near future.

  11. Magnetic fusion driventransmutation of nuclear waste (FTW)

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.

    1993-01-01

    The possibility of magnetic Fusion driven Transmutation of Waste (FTW) was revisted and discussed recently. Nuclear wastes include all transuranium elements: Pu isotopes, minor actinides separated from the spent fission fuel, and fissile products. Elimination of thse long-life nuclear wastes is necessary for the long-term viability of fission power. A Small Business Innovative Research program has been initiated under the leadership of TSI Research to examine the efficacy of fusion transmutation of waste utilizing small fusion drivers.

  12. High-Frequency Gravitational Wave Induced Nuclear Fusion

    SciTech Connect

    Fontana, Giorgio; Baker, Robert M. L. Jr.

    2007-01-30

    Nuclear fusion is a process in which nuclei, having a total initial mass, combine to produce a single nucleus, having a final mass less than the total initial mass. Below a given atomic number the process is exothermic; that is, since the final mass is less than the combined initial mass and the mass deficit is converted into energy by the nuclear fusion. On Earth nuclear fusion does not happen spontaneously because electrostatic barriers prevent the phenomenon. To induce controlled, industrial scale, nuclear fusion, only a few methods have been discovered that look promising, but net positive energy production is not yet possible because of low overall efficiency of the systems. In this paper we propose that an intense burst of High Frequency Gravitational Waves (HFGWs) could be focused or beamed to a target mass composed of appropriate fuel or target material to efficiently rearrange the atomic or nuclear structure of the target material with consequent nuclear fusion. Provided that efficient generation of HFGW can be technically achieved, the proposed fusion reactor could become a viable solution for the energy needs of mankind and alternatively a process for beaming energy to produce a source of fusion energy remotely - even inside solid materials.

  13. 2015 Nuclear Fusion Prize acceptance speech

    SciTech Connect

    Goldston, R. J.

    2016-12-19

    This is the 2015 Nuclear Fusion Prize acceptance speech of R.J. Goldston: It is a great pleasure to receive the 2015 Nuclear Fusion award for my work developing a heuristic drift-based model for the power scrape-off width in tokamaks. I was particularly pleased to receive the award from IAEA Director General Yukiya Amano, whose thoughtful leadership has advanced the cause of nuclear non-proliferation mightily.

  14. 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.

  15. Controlled Nuclear Fusion: Status and Outlook

    ERIC Educational Resources Information Center

    Rose, David J.

    1971-01-01

    Presents the history, current concerns and potential developments of nuclear fusion as a major energy source. Controlled fusion research is summarized, technological feasibility is discussed and environmental factors are examined. Relationships of alternative energy sources as well as energy utilization are considered. (JM)

  16. Mass Producing Targets for Nuclear Fusion

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Elleman, D. D.; Kendall, J. M.

    1983-01-01

    Metal-encapsulating technique advances prospects of controlling nuclear fusion. Prefilled fusion targets form at nozzle as molten metal such as tin flows through outer channel and pressurized deuterium/tritium gas flows through inner channel. Molten metal completely encloses gas charge as it drops off nozzle.

  17. History of Nuclear Fusion Research in Japan

    NASA Astrophysics Data System (ADS)

    Iguchi, Harukazu; Matsuoka, Keisuke; Kimura, Kazue; Namba, Chusei; Matsuda, Shinzaburo

    In the late 1950s just after the atomic energy research was opened worldwide, there was a lively discussion among scientists on the strategy of nuclear fusion research in Japan. Finally, decision was made that fusion research should be started from the basic, namely, research on plasma physics and from cultivation of human resources at universities under the Ministry of Education, Science and Culture (MOE). However, an endorsement was given that construction of an experimental device for fusion research would be approved sooner or later. Studies on toroidal plasma confinement started at Japan Atomic Energy Research Institute (JAERI) under the Science and Technology Agency (STA) in the mid-1960s. Dualistic fusion research framework in Japan was established. This structure has lasted until now. Fusion research activities over the last 50 years are described by the use of a flowchart, which is convenient to glance the historical development of fusion research in Japan.

  18. Nuclear diagnostics for inertial confinement fusion implosions

    SciTech Connect

    Murphy, T.J.

    1997-11-01

    This abstract contains viewgraphs on nuclear diagnostic techniques for inertial confinement fusion implosions. The viewgraphs contain information on: reactions of interest in ICF; advantages and disadvantages of these methods; the properties nuclear techniques can measure; and some specifics on the detectors used.

  19. Nuclear structure and sub-barrier fusion

    SciTech Connect

    Esbensen, H. . Cyclotron Lab. Argonne National Lab., IL )

    1990-01-01

    The influence of nuclear structure on heavy-ion fusion and elastic scattering, at energies near and below the Coulomb barrier, is discussed within the coupled channels formalism. The coupled channels approach provides a consistent description of the enhancement of sub-barrier fusion and the energy dependence of the effective potential for elastic scattering. This is illustrated by comparison to the data for several systems. 48 refs., 4 figs.

  20. 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.

  1. 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.

  2. Sensor Fusion for Nuclear Proliferation Activity Monitoring

    SciTech Connect

    Adel Ghanem, Ph D

    2007-03-30

    The objective of Phase 1 of this STTR project is to demonstrate a Proof-of-Concept (PoC) of the Geo-Rad system that integrates a location-aware SmartTag (made by ZonTrak) and a radiation detector (developed by LLNL). It also includes the ability to transmit the collected radiation data and location information to the ZonTrak server (ZonService). The collected data is further transmitted to a central server at LLNL (the Fusion Server) to be processed in conjunction with overhead imagery to generate location estimates of nuclear proliferation and radiation sources.

  3. Is Deuterium Nuclear Fusion Catalyzed by Antineutrinos?

    NASA Astrophysics Data System (ADS)

    Shomer, Isaac

    2010-02-01

    The hypothesis of Fischbach and Jenkins that neutrinos emitted from the sun accelerate radioactive decay is noted. It is thought that neutrinos accelerate beta decay by reacting with neutron-rich nuclides to form a beta particle and a daughter product, with no antineutrino emitted. Conversely, it is proposed that antineutrinos can react with proton-rich nuclides to cause positron decay, with no neutrino emitted. It is also proposed that the nuclear fusion of the hydrogen bomb is triggered not only by the energy of the igniting fission bomb, but by the antineutrinos created by the rapid beta decay of the daughter products in the fission process. The contemplated mechanism for antineutrino initiated fusion is the following: 1. The antineutrinos from the fission daughter products cause positron decay of deuterium by the process outlined above. 2. In a later fusion step, these positrons subsequently react with neutrons in deuterium to create antineutrinos. Electrons are unavailable to annihilate positrons in the plasma of the hydrogen bomb. 3. These antineutrinos thereafter react with more deuterium to form positrons, thereby propagating a chain reaction. )

  4. Decoding the nuclear genome using nuclear binding and fusion energies

    NASA Astrophysics Data System (ADS)

    Yablon, Jay R.

    2015-04-01

    In several publications the author has presented the theory that protons and neutrons and other baryons are the chromo-magnetic monopoles of Yang-Mills gauge theory and used that to deduce the up and down current quark masses from the tightly-known Q = 0 empirical electron mass and the neutron minus proton mass difference with commensurately high precision. This is then used as a springboard to closely fit a wide range of empirical nuclear binding and fusion energy data and to obtain the proton and neutron masses themselves within all experimental errors. This presentation will systematically pull all of this together and a) establishes that this way of defining current quark masses constitutes a valid measurement scheme, b) lays out the empirical support for this theory via observed nuclear binding and fusion energies as well as the proton and neutron masses themselves, c) solidifies the interface used to connect the theory to these empirical results and uncovers a mixing between the up and down current quark masses, and d) presents clearly how and why the underlying theory is very conservative, being no more and no less than a deductive mathematical synthesis of Maxwell's classical theory with both the electric and magnetic field equations merged into one, Yang-Mills gauge theory, Dirac fermion theory, the Fermi-Dirac-Pauli Exclusion Principle, and to get from classical chromodynamics to QCD, Feynman path integration.

  5. Distinct roles for key karyogamy proteins during yeast nuclear fusion.

    PubMed

    Melloy, Patricia; Shen, Shu; White, Erin; Rose, Mark D

    2009-09-01

    During yeast mating, cell fusion is followed by the congression and fusion of the two nuclei. Proteins required for nuclear fusion are found at the surface (Prm3p) and within the lumen (Kar2p, Kar5p, and Kar8p) of the nuclear envelope (NE). Electron tomography (ET) of zygotes revealed that mutations in these proteins block nuclear fusion with different morphologies, suggesting that they act in different steps of fusion. Specifically, prm3 zygotes were blocked before formation of membrane bridges, whereas kar2, kar5, and kar8 zygotes frequently contained them. Membrane bridges were significantly larger and occurred more frequently in kar2 and kar8, than in kar5 mutant zygotes. The kinetics of NE fusion in prm3, kar5, and kar8 mutants, measured by live-cell fluorescence microscopy, were well correlated with the size and frequency of bridges observed by ET. However the kar2 mutant was defective for transfer of NE lumenal GFP, but not diffusion within the lumen, suggesting that transfer was blocked at the NE fusion junction. These observations suggest that Prm3p acts before initiation of outer NE fusion, Kar5p may help dilation of the initial fusion pore, and Kar2p and Kar8p act after outer NE fusion, during inner NE fusion.

  6. Kinetic advantage of controlled intermediate nuclear fusion

    SciTech Connect

    Guo Xiaoming

    2012-09-26

    The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion very difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.

  7. Magnet design considerations for Fusion Nuclear Science Facility

    SciTech Connect

    Zhai, Yuhu; Kessel, Chuck; El-guebaly, Laila; Titus, Peter

    2016-02-25

    The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility to provide a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between ITER and the demonstration power plant (DEMO). Compared to ITER, the FNSF is smaller in size but generates much higher magnetic field, 30 times higher neutron fluence with 3 orders of magnitude longer plasma operation at higher operating temperatures for structures surrounding the plasma. Input parameters to the magnet design from system code analysis include magnetic field of 7.5 T at the plasma center with plasma major radius of 4.8 m and minor radius of 1.2 m, and a peak field of 15.5 T on the TF coils for FNSF. Both low temperature superconductor (LTS) and high temperature superconductor (HTS) are considered for the FNSF magnet design based on the state-of-the-art fusion magnet technology. The higher magnetic field can be achieved by using the high performance ternary Restack Rod Process (RRP) Nb3Sn strands for toroidal field (TF) magnets. The circular cable-in-conduit conductor (CICC) design similar to ITER magnets and a high aspect ratio rectangular CICC design are evaluated for FNSF magnets but low activation jacket materials may need to be selected. The conductor design concept and TF coil winding pack composition and dimension based on the horizontal maintenance schemes are discussed. Neutron radiation limits for the LTS and HTS superconductors and electrical insulation materials are also reviewed based on the available materials previously tested. As a result, the material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets.

  8. Magnet Design Considerations for Fusion Nuclear Science Facility

    SciTech Connect

    Zhai, Y.; Kessel, C.; El-Guebaly, L.; Titus, P.

    2016-06-01

    The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility that provides a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between the International Thermonuclear Experimental Reactor (ITER) and the demonstration power plant (DEMO). Compared with ITER, the FNSF is smaller in size but generates much higher magnetic field, i.e., 30 times higher neutron fluence with three orders of magnitude longer plasma operation at higher operating temperatures for structures surrounding the plasma. Input parameters to the magnet design from system code analysis include magnetic field of 7.5 T at the plasma center with a plasma major radius of 4.8 m and a minor radius of 1.2 m and a peak field of 15.5 T on the toroidal field (TF) coils for the FNSF. Both low-temperature superconductors (LTS) and high-temperature superconductors (HTS) are considered for the FNSF magnet design based on the state-of-the-art fusion magnet technology. The higher magnetic field can be achieved by using the high-performance ternary restacked-rod process Nb3Sn strands for TF magnets. The circular cable-in-conduit conductor (CICC) design similar to ITER magnets and a high-aspect-ratio rectangular CICC design are evaluated for FNSF magnets, but low-activation-jacket materials may need to be selected. The conductor design concept and TF coil winding pack composition and dimension based on the horizontal maintenance schemes are discussed. Neutron radiation limits for the LTS and HTS superconductors and electrical insulation materials are also reviewed based on the available materials previously tested. The material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets.

  9. Magnet design considerations for Fusion Nuclear Science Facility

    DOE PAGES

    Zhai, Yuhu; Kessel, Chuck; El-guebaly, Laila; ...

    2016-02-25

    The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility to provide a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between ITER and the demonstration power plant (DEMO). Compared to ITER, the FNSF is smaller in size but generates much higher magnetic field, 30 times higher neutron fluence with 3 orders of magnitude longer plasma operation at higher operating temperatures for structures surrounding the plasma. Input parameters to the magnet design from system code analysis include magnetic field of 7.5 T at the plasma center withmore » plasma major radius of 4.8 m and minor radius of 1.2 m, and a peak field of 15.5 T on the TF coils for FNSF. Both low temperature superconductor (LTS) and high temperature superconductor (HTS) are considered for the FNSF magnet design based on the state-of-the-art fusion magnet technology. The higher magnetic field can be achieved by using the high performance ternary Restack Rod Process (RRP) Nb3Sn strands for toroidal field (TF) magnets. The circular cable-in-conduit conductor (CICC) design similar to ITER magnets and a high aspect ratio rectangular CICC design are evaluated for FNSF magnets but low activation jacket materials may need to be selected. The conductor design concept and TF coil winding pack composition and dimension based on the horizontal maintenance schemes are discussed. Neutron radiation limits for the LTS and HTS superconductors and electrical insulation materials are also reviewed based on the available materials previously tested. As a result, the material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets.« less

  10. Observation of Nuclear Fusion in Sonoluminescence

    SciTech Connect

    Taleyarkhan, Rusi

    2004-07-14

    The intense implosive collapse of bubbles, including acoustic cavitation bubbles, can lead to extremely high compressions and temperatures, and to the generation of light flashes attributed to sonoluminescence (SL). A novel technique was developed to induce ultra-high compressions and temperatures during SL events. Time spectra of neutron and SL emissions were measured in cavitation experiments with deuterated acetone. Statistically significant neutron and gamma ray emissions were measured with a calibrated liquid-scintillation detector along with SL emissions. The neutron and SL emissions were found to be time correlated over the time of significant bubble cluster dynamics. The neutron emission energy corresponded to < 2.45 MeV and had an emission rate of up to {approx}4-5 x 10{sup 5} n/s accompanied with gamma rays. Measurements of tritium production were also performed and these data implied a neutron emission rate due to D-D nuclear fusion which agreed with what was measured. In contrast, control experiments using normal acetone did not result in statistically significant tritium activity, or neutron or gamma ray emissions. The speaker will discuss experimental, modeling/simulation aspects along with remaining challenges and opportunities.

  11. Recent Developments in Cold Fusion / Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Krivit, Steven B.

    2006-03-01

    Krivit is recognized internationally as an expert on the subject matter of cold fusion / condensed matter nuclear science. He is the editor of New Energy Times, the leading source of information for the field of cold fusion. He is the author of the 2005 book, The Rebirth of Cold Fusion and founder of New Energy Institute, an independent nonprofit public benefit corporation dedicated to accelerating the progress of new, sustainable and environmentally friendly energy sources.

  12. The Fight for Fusion: A Modern Nuclear War.

    ERIC Educational Resources Information Center

    Rogers, Adam; Sereda, David

    1992-01-01

    Describes the work of Bogdan Maglich with helium-based fusion and barriers to its development resulting from lack of government support, competition for funding, and political pet projects. Compares tritium-based to helium-based fusion and the potential for nonradioactive nuclear power to supply the world's energy requirements with no negative…

  13. Penetration Factor for Nuclear Fusion Reaction in Nonthermal Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Ki, Dai-Han; Jung, Young-Dae

    2011-02-01

    The nonthermal effects on the nuclear fusion reaction process are investigated in Lorentzian astrophysical plasmas. The closed expression of the classical turning point in Lorentzian plasmas is obtained by the Lambert W-function. Using the WKB analysis with the effective screening length, the closed expressions of the fusion penetration factor and the cross section for the nuclear fusion reaction in Lorentzian plasmas are obtained as functions of the spectral index, relative kinetic energy, and plasma parameters. It is shown that the nonthermal character of the Lorentzian plasma enhances the fusion penetration factor. In addition, the nonthermal effect on the penetration factor is found to be more significant in plasmas with higher densities. It would be expected that the fusion reaction rates of the p-p chain and the CNO cycle in nonthermal plasmas are always greater than those in thermal Maxwellian plasmas.

  14. [Two-nuclear neurons: sincitial fusion or amitotic division].

    PubMed

    Sotnikov, O S; Frumkina, L E; Lactionova, A A; Paramonova, N M; Novakovskaia, S A

    2011-01-01

    In the review the history of research two-nuclear neurons is stated and two hypotheses about mechanisms of their formation are analysed: by sincitial fusion or amytotic divisions. The facts of discrepancy of the former orthodox cellular theory categorically denying possibility sincitial of communications in nervous system and of sincitial fusion neurons are mentioned. As an example results of ultrastructural researches of occurrence sincitium in a cortex of the big brain of rats, in autonomic ganglions, in hypocampus and a cerebellum of adult animals are presented. The video data of the sincitial fusion of live neurons and the mechanism of formation multinuclear neurons in tissue culture are analyzed. Existing data about amytotic a way of formation two-nuclear neurons are critically considered. The conclusion becomes, that the mechanism of formation two-nuclear neurons is cellular fusion. Simultaneously the review confirms our representations about existence in nervous system sincitial interneural communications.

  15. 2014 Nuclear Fusion Prize Acceptance Speech 2014 Nuclear Fusion Prize Acceptance Speech

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.

    2015-01-01

    It is a great honor to receive the 2014 Nuclear Fusion Prize, here at the 25th IAEA Fusion Energy Conference. On behalf of everyone involved in this work, I would like to thank the IAEA, the Nuclear Fusion journal team, the IOP, and specifically Mitsuru Kikuchi, for their support of this important award. I would also like to acknowledge the many important contributions made by the other ten papers nominated for this prize. Our paper investigates the physics of the H-mode pedestal in tokamaks, specifically the development of a predictive understanding of the pedestal structure based on electromagnetic instabilities which constrain it, and the testing of the resulting theoretical model (EPED) against detailed observations on multiple devices. In addition to making pedestal predictions for existing devices, the paper also presents predictions for ITER, including methods for optimizing its pedestal height and fusion performance. What made this work possible, and indeed a pleasure to be involved with, was an extensive set of collaborations, including theory-experiment, multi-institutional, and international collaborations. Many of these collaborations have gone on for over a decade, and have been fostered in part by the ITPA Pedestal Group. The eight authors of this paper, from five institutions, all made important contributions. Rich Groebner, Tom Osborne and Tony Leonard carried out dedicated experiments and data analysis on the DIII-D tokamak, testing the EPED model over a very wide range of parameters. Jerry Hughes led dedicated experiments on Alcator C-Mod which tested the model at high magnetic field and pedestal pressure. Marc Beurskens carried out experiments and data analysis on the JET tokamak, testing the model at large scale. Xueqiao Xu conducted two-fluid studies of diamagnetic stabilization, which enabled a more accurate treatment of this important effect. Finally, Howard Wilson and I have been working together for many years to develop analytic formalism

  16. Fusion Nuclear Science Facility (FNSF) motivation and required capabilities

    NASA Astrophysics Data System (ADS)

    Peng, Y. K. M.; Park, J. M.; Canik, J. M.; Diem, S. J.; Sontag, A. C.; Lumsdaine, A.; Murakami, M.; Katoh, Y.; Burgess, T. W.; Korsah, K.; Patton, B. D.; Wagner, J. C.; Yoder, G. L.; Cole, M. J.; Fogarty, P. J.; Sawan, M.

    2011-10-01

    A compact (R0 ~ 1.2-1.3m), low aspect ratio, low-Q (<3) Fusion Nuclear Science Facility (FNSF) was recently assessed to provide a fully integrated, D-T-fueled, continuously driven plasma, volumetric nuclear environment of copious neutrons. This environment would be used to carry out, for the first time, discovery-driven research in fusion nuclear science and materials, in parallel with and complementary to ITER. This research would aim to test, discover, and understand new nuclear-nonnuclear synergistic interactions involving plasma material interactions, neutron material interactions, tritium fuel breeding and transport, and power extraction, and innovate and develop solutions for DEMO components. Progress will be reported on the fusion nuclear-nonnuclear coupling effects identified that motivate research on such an FNSF, and on the required capabilities in fusion plasma, device operation, and fusion nuclear science and engineering to fulfill its mission. Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725.

  17. In vivo myomaker-mediated heterologous fusion and nuclear reprogramming.

    PubMed

    Mitani, Yasuyuki; Vagnozzi, Ronald J; Millay, Douglas P

    2017-01-01

    Knowledge regarding cellular fusion and nuclear reprogramming may aid in cell therapy strategies for skeletal muscle diseases. An issue with cell therapy approaches to restore dystrophin expression in muscular dystrophy is obtaining a sufficient quantity of cells that normally fuse with muscle. Here we conferred fusogenic activity without transdifferentiation to multiple non-muscle cell types and tested dystrophin restoration in mouse models of muscular dystrophy. We previously demonstrated that myomaker, a skeletal muscle-specific transmembrane protein necessary for myoblast fusion, is sufficient to fuse 10T 1/2 fibroblasts to myoblasts in vitro. Whether myomaker-mediated heterologous fusion is functional in vivo and whether the newly introduced nonmuscle nuclei undergoes nuclear reprogramming has not been investigated. We showed that mesenchymal stromal cells, cortical bone stem cells, and tail-tip fibroblasts fuse to skeletal muscle when they express myomaker. These cells restored dystrophin expression in a fraction of dystrophin-deficient myotubes after fusion in vitro. However, dystrophin restoration was not detected in vivo although nuclear reprogramming of the muscle-specific myosin light chain promoter did occur. Despite the lack of detectable dystrophin reprogramming by immunostaining, this study indicated that myomaker could be used in nonmuscle cells to induce fusion with muscle in vivo, thereby providing a platform to deliver therapeutic material.-Mitani, Y., Vagnozzi, R. J., Millay, D. P. In vivo myomaker-mediated heterologous fusion and nuclear reprogramming.

  18. Nuclear Propulsion through Direct Conversion of Fusion Energy: The Fusion Driven Rocket

    NASA Technical Reports Server (NTRS)

    Slough, John; Pancotti, Anthony; Kirtley, David; Pihl, Christopher; Pfaff, Michael

    2012-01-01

    The future of manned space exploration and development of space depends critically on the creation of a dramatically more proficient propulsion architecture for in-space transportation. A very persuasive reason for investigating the applicability of nuclear power in rockets is the vast energy density gain of nuclear fuel when compared to chemical combustion energy. Current nuclear fusion efforts have focused on the generation of electric grid power and are wholly inappropriate for space transportation as the application of a reactor based fusion-electric system creates a colossal mass and heat rejection problem for space application.

  19. Nuclear fusion and genome encounter during yeast zygote formation.

    PubMed

    Tartakoff, Alan Michael; Jaiswal, Purnima

    2009-06-01

    When haploid cells of Saccharomyces cerevisiae are crossed, parental nuclei congress and fuse with each other. To investigate underlying mechanisms, we have developed assays that evaluate the impact of drugs and mutations. Nuclear congression is inhibited by drugs that perturb the actin and tubulin cytoskeletons. Nuclear envelope (NE) fusion consists of at least five steps in which preliminary modifications are followed by controlled flux of first outer and then inner membrane proteins, all before visible dilation of the waist of the nucleus or coalescence of the parental spindle pole bodies. Flux of nuclear pore complexes occurs after dilation. Karyogamy requires both the Sec18p/NSF ATPase and ER/NE luminal homeostasis. After fusion, chromosome tethering keeps tagged parental genomes separate from each other. The process of NE fusion and evidence of genome independence in yeast provide a prototype for understanding related events in higher eukaryotes.

  20. 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.

  1. Cytosol-dependent membrane fusion in ER, nuclear envelope and nuclear pore assembly: biological implications.

    PubMed

    Rafikova, Elvira R; Melikov, Kamran; Chernomordik, Leonid V

    2010-01-01

    Endoplasmic reticulum and nuclear envelope rearrangements after mitosis are often studied in the reconstitution system based on Xenopus egg extract. In our recent work we partially replaced the membrane vesicles in the reconstitution mix with protein-free liposomes to explore the relative contributions of cytosolic and transmembrane proteins. Here we discuss our finding that cytosolic proteins mediate fusion between membranes lacking functional transmembrane proteins and the role of membrane fusion in endoplasmic reticulum and nuclear envelope reorganization. Cytosol-dependent liposome fusion has allowed us to restore, without adding transmembrane nucleoporins, functionality of nuclear pores, their spatial distribution and chromatin decondensation in nuclei formed at insufficient amounts of membrane material and characterized by only partial decondensation of chromatin and lack of nuclear transport. Both the mechanisms and the biological implications of the discovered coupling between spatial distribution of nuclear pores, chromatin decondensation and nuclear transport are discussed.

  2. 2013 Nuclear Fusion Prize Acceptance Speech 2013 Nuclear Fusion Prize Acceptance Speech

    NASA Astrophysics Data System (ADS)

    Whyte, D.

    2015-01-01

    I would like to express gratitude to the IAEA, the journal Nuclear Fusion and its board for this acknowledgement of work carried out at the MIT Alcator C-Mod tokamak. I must begin by making it clear that this is in no way an award to an individual. The experiments, data analysis and paper were a true collaborative effort from the C-Mod team. It is a honor to work with them and to accept the award on their behalf. I would also like to thank the US Department of Energy for their support in funding this research. The paper describes the exploration of the 'improved' confinement regime dubbed 'I-mode'. The distinguishing feature of this operational mode is a robust boundary pedestal in temperature with the somewhat surprising lack of any form of density pedestal. Thus the regime exhibits an enhanced energy confinement similar to H-mode, roughly double of L-mode at fixed input power, yet has global fuel and impurity particle transport of L-mode. These features are intriguing from a scientific and practical point of view. On the science side it is extremely useful to obtain such a clear demarcation between the energy and particle transport. For example, soon after its discovery, the I-mode was used to extract the observation that the edge T pedestal is the strongest determinant for intrinsic rotation in work by John Rice, Pat Diamond and colleagues. Recent results regarding core transport by Anne White, Nate Howard and colleagues show that I-mode has intriguing properties with respect to core response of fluctuations and profile stiffness. Mike Churchill's recent Ph. D study on C-Mod shows that I-mode exhibits no strong poloidal impurity asymmetry, unlike H-mode. The I-mode posed an interesting test for the peeling-ballooning-KBM model of the pedestal, the subject of the 2014 Nuclear Fusion award of Phil Snyder, and was examined by John Walk and Jerry Hughes showing that in fact the lack of the density pedestal pushed the I-mode far away from the P-B limit, and thus the

  3. Z-Pinch fusion-based nuclear propulsion

    NASA Astrophysics Data System (ADS)

    Miernik, J.; Statham, G.; Fabisinski, L.; Maples, C. D.; Adams, R.; Polsgrove, T.; Fincher, S.; Cassibry, J.; Cortez, R.; Turner, M.; Percy, T.

    2013-02-01

    Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Due to the great distances between the planets of our solar system and the harmful radiation environment of interplanetary space, high specific impulse (Isp) propulsion in vehicles with high payload mass fractions must be developed to provide practical and safe vehicles for human space flight missions. The Z-Pinch dense plasma focus method is a Magneto-Inertial Fusion (MIF) approach that may potentially lead to a small, low cost fusion reactor/engine assembly [1]. Recent advancements in experimental and theoretical understanding of this concept suggest favorable scaling of fusion power output yield [2]. The magnetic field resulting from the large current compresses the plasma to fusion conditions, and this process can be pulsed over short timescales (10-6 s). This type of plasma formation is widely used in the field of Nuclear Weapons Effects testing in the defense industry, as well as in fusion energy research. A Z-Pinch propulsion concept was designed for a vehicle based on a previous fusion vehicle study called "Human Outer Planet Exploration" (HOPE), which used Magnetized Target Fusion (MTF) [3] propulsion. The reference mission is the transport of crew and cargo to Mars and back, with a reusable vehicle. The analysis of the Z-Pinch MIF propulsion system concludes that a 40-fold increase of Isp over chemical propulsion is predicted. An Isp of 19,436 s and thrust of 3812 N s/pulse, along with nearly doubling the predicted payload mass fraction, warrants further development of enabling technologies.

  4. Importin beta negatively regulates nuclear membrane fusion and nuclear pore complex assembly.

    PubMed

    Harel, Amnon; Chan, Rene C; Lachish-Zalait, Aurelie; Zimmerman, Ella; Elbaum, Michael; Forbes, Douglass J

    2003-11-01

    Assembly of a eukaryotic nucleus involves three distinct events: membrane recruitment, fusion to form a double nuclear membrane, and nuclear pore complex (NPC) assembly. We report that importin beta negatively regulates two of these events, membrane fusion and NPC assembly. When excess importin beta is added to a full Xenopus nuclear reconstitution reaction, vesicles are recruited to chromatin but their fusion is blocked. The importin beta down-regulation of membrane fusion is Ran-GTP reversible. Indeed, excess RanGTP (RanQ69L) alone stimulates excessive membrane fusion, leading to intranuclear membrane tubules and cytoplasmic annulate lamellae-like structures. We propose that a precise balance of importin beta to Ran is required to create a correct double nuclear membrane and simultaneously to repress undesirable fusion events. Interestingly, truncated importin beta 45-462 allows membrane fusion but produces nuclei lacking any NPCs. This reveals distinct importin beta-regulation of NPC assembly. Excess full-length importin beta and beta 45-462 act similarly when added to prefused nuclear intermediates, i.e., both block NPC assembly. The importin beta NPC block, which maps downstream of GTPgammaS and BAPTA-sensitive steps in NPC assembly, is reversible by cytosol. Remarkably, it is not reversible by 25 microM RanGTP, a concentration that easily reverses fusion inhibition. This report, using a full reconstitution system and natural chromatin substrates, significantly expands the repertoire of importin beta. Its roles now encompass negative regulation of two of the major events of nuclear assembly: membrane fusion and NPC assembly.

  5. The Fukushima nuclear disaster and its effects on media framing of fission and fusion energy technologies

    SciTech Connect

    Schmidt, Luisa; Horta, Ana; Pereira, Sergio; Delicado, Ana

    2015-07-01

    This paper presents results of a comparison of media coverage of fusion and fission energy technologies in three countries (Germany, Spain and Portugal) and in the English language international print media addressing transnational elite, from 2008 to 2012. The analysis showed that the accident in Fukushima in March 2010 did not have significant impact on media framing of nuclear fusion in the major part of print media under investigation. In fact, fusion is clearly dissociated from traditional nuclear (fission) energy and from nuclear accidents. It tends to be portrayed as a safe, clean and unlimited source of energy, although less credited when confronted with research costs, technological feasibility and the possibility to be achieved in a reasonable period of time. On the contrary, fission is portrayed as a hazardous source of energy, expensive when compared to research costs of renewables, hardly a long-term energy option, susceptible to contribute to the proliferation of nuclear weapons or rogue military use. Fukushima accident was consistently discussed in the context of safety problems of nuclear power plants and in many cases appeared not as an isolated event but rather as a reminder of previous nuclear disasters such as Three Miles Island and Chernobyl. (authors)

  6. Preventing Nuclear War: What Physicians Can Achieve

    PubMed Central

    Bates, Don G.

    1986-01-01

    On its fifth anniversary, the International Physicians for the Prevention of Nuclear War was awarded the Nobel Peace Prize. The organization was conceived by two Boston cardiologists who joined with some Soviet colleagues to create an international forum for considering the medical consequences of and means for preventing nuclear war. This article by the organization's archivist documents its difficult progress yet remarkable growth. Overcoming serious obstacles has added to its strength and credibility: now involving organizations with 145,000 members in 41 countries, IPPNW has become the international voice of medicine's concern about nuclear war. PMID:21274253

  7. Inner/Outer nuclear membrane fusion in nuclear pore assembly: biochemical demonstration and molecular analysis.

    PubMed

    Fichtman, Boris; Ramos, Corinne; Rasala, Beth; Harel, Amnon; Forbes, Douglass J

    2010-12-01

    Nuclear pore complexes (NPCs) are large proteinaceous channels embedded in double nuclear membranes, which carry out nucleocytoplasmic exchange. The mechanism of nuclear pore assembly involves a unique challenge, as it requires creation of a long-lived membrane-lined channel connecting the inner and outer nuclear membranes. This stabilized membrane channel has little evolutionary precedent. Here we mapped inner/outer nuclear membrane fusion in NPC assembly biochemically by using novel assembly intermediates and membrane fusion inhibitors. Incubation of a Xenopus in vitro nuclear assembly system at 14°C revealed an early pore intermediate where nucleoporin subunits POM121 and the Nup107-160 complex were organized in a punctate pattern on the inner nuclear membrane. With time, this intermediate progressed to diffusion channel formation and finally to complete nuclear pore assembly. Correct channel formation was blocked by the hemifusion inhibitor lysophosphatidylcholine (LPC), but not if a complementary-shaped lipid, oleic acid (OA), was simultaneously added, as determined with a novel fluorescent dextran-quenching assay. Importantly, recruitment of the bulk of FG nucleoporins, characteristic of mature nuclear pores, was not observed before diffusion channel formation and was prevented by LPC or OA, but not by LPC+OA. These results map the crucial inner/outer nuclear membrane fusion event of NPC assembly downstream of POM121/Nup107-160 complex interaction and upstream or at the time of FG nucleoporin recruitment.

  8. Oral cancer/endothelial cell fusion experiences nuclear fusion and acquisition of enhanced survival potential

    SciTech Connect

    Song, Kai; Song, Yong; Zhao, Xiao-Ping; Shen, Hui; Wang, Meng; Yan, Ting-lin; Liu, Ke; Shang, Zheng-jun

    2014-10-15

    Most previous studies have linked cancer–macrophage fusion with tumor progression and metastasis. However, the characteristics of hybrid cells derived from oral cancer and endothelial cells and their involvement in cancer remained unknown. Double-immunofluorescent staining and fluorescent in situ hybridization (FISH) were performed to confirm spontaneous cell fusion between eGFP-labeled human umbilical vein endothelial cells (HUVECs) and RFP-labeled SCC9, and to detect the expression of vementin and cytokeratin 18 in the hybrids. The property of chemo-resistance of such hybrids was examined by TUNEL assay. The hybrid cells in xenografted tumor were identified by FISH and GFP/RFP dual-immunofluoresence staining. We showed that SCC9 cells spontaneously fused with cocultured endothelial cells, and the resultant hybrid cells maintained the division and proliferation activity after re-plating and thawing. Such hybrids expressed markers of both parental cells and became more resistant to chemotherapeutic drug cisplatin as compared to the parental SCC9 cells. Our in vivo data indicated that the hybrid cells contributed to tumor composition by using of immunostaining and FISH analysis, even though the hybrid cells and SCC9 cells were mixed with 1:10,000, according to the FACS data. Our study suggested that the fusion events between oral cancer and endothelial cells undergo nuclear fusion and acquire a new property of drug resistance and consequently enhanced survival potential. These experimental findings provide further supportive evidence for the theory that cell fusion is involved in cancer progression. - Highlights: • The fusion events between oral cancer and endothelial cells undergo nuclear fusion. • The resulting hybrid cells acquire a new property of drug resistance. • The resulting hybrid cells express the markers of both parental cells (i.e. vimentin and cytokeratin 18). • The hybrid cells contribute to tumor repopulation in vivo.

  9. Optical design of a laser system for nuclear fusion research.

    PubMed

    de Metz, J

    1971-07-01

    High power laser improvements, high quality aspheric lenses, and sharp focusing on a solid deuterium target enable us to get numerous nuclear fusion reactions inside the deuterium plasma. Since Maiman successfully built the first light amplifier in 1960 [Nature 187, 493 (1960)] and Terhune performed air breakdown experiments in 1962 ["Optical Third Harmonic Generation," Comptes rendus de la 3ème Conférence Internationale d'Electronique Quantique, Paris, 11-15 février 1963, P. Grivet and N. Bloembergen, Eds. (Dunod, Paris, 1964), pp. 1559-15761, the laser has been thought of as a valuable energy source for fusion devices. Now a kind of race has started toward high temperature plasmas created by powerful lasers. However, the peak power of solid state laser is limited by glass damage, pump efficiences, and unwanted effects such as superradiance. So it is necessary to improve all the optical properties of the laser and the focusing of the lens on the target. In this paper, requirements for fusion implying a very high flux will be stated. Successive optical designs will be described together with measurement methods, and the contribution of optical improvements to the occurrence of nuclear fusion reaction in deuterium targets will be evaluated.

  10. Review of LIBS application in nuclear fusion technology

    NASA Astrophysics Data System (ADS)

    Li, Cong; Feng, Chun-Lei; Oderji, Hassan Yousefi; Luo, Guang-Nan; Ding, Hong-Bin

    2016-12-01

    Nuclear fusion has enormous potential to greatly affect global energy production. The next-generation tokamak ITER, which is aimed at demonstrating the feasibility of energy production from fusion on a commercial scale, is under construction. Wall erosion, material transport, and fuel retention are known factors that shorten the lifetime of ITER during tokamak operation and give rise to safety issues. These factors, which must be understood and solved early in the process of fusion reactor design and development, are among the most important concerns for the community of plasma-wall interaction researchers. To date, laser techniques are among the most promising methods that can solve these open ITER issues, and laser-induced breakdown spectroscopy (LIBS) is an ideal candidate for online monitoring of the walls of current and next-generation (such as ITER) fusion devices. LIBS is a widely used technique for various applications. It has been considered recently as a promising tool for analyzing plasma-facing components in fusion devices in situ. This article reviews the experiments that have been performed by many research groups to assess the feasibility of LIBS for this purpose.

  11. Kem Mutations Affect Nuclear Fusion in Saccharomyces Cerevisiae

    PubMed Central

    Kim, J.; Ljungdahl, P. O.; Fink, G. R.

    1990-01-01

    We have identified mutations in three genes of Saccharomyces cerevisiae, KEM1, KEM2 and KEM3, that enhance the nuclear fusion defect of kar1-1 yeast during conjugation. The KEM1 and KEM3 genes are located on the left arm of chromosome VII. Kem mutations reduce nuclear fusion whether the kem and the kar1-1 mutations are in the same or in different parents (i.e., in both kem kar1-1 X wild-type and kem X kar1-1 crosses). kem1 X kem1 crosses show a defect in nuclear fusion, but kem1 X wild-type crosses do not. Mutant kem1 strains are hypersensitive to benomyl, lose chromosomes at a rate 10-20-fold higher than KEM(+) strains, and lose viability upon nitrogen starvation. In addition, kem1/kem1 diploids are unable to sporulate. Cells containing a kem1 null allele grow very poorly, have an elongated rod-shape and are defective in spindle pole body duplication and/or separation. The KEM1 gene, which is expressed as a 5.5-kb mRNA transcript, contains a 4.6-kb open reading frame encoding a 175-kD protein. PMID:2076815

  12. Cell-fusion method to visualize interphase nuclear pore formation.

    PubMed

    Maeshima, Kazuhiro; Funakoshi, Tomoko; Imamoto, Naoko

    2014-01-01

    In eukaryotic cells, the nucleus is a complex and sophisticated organelle that organizes genomic DNA to support essential cellular functions. The nuclear surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It is well known that the number of NPCs almost doubles during interphase in cycling cells. However, the mechanism of NPC formation is poorly understood, presumably because a practical system for analysis does not exist. The most difficult obstacle in the visualization of interphase NPC formation is that NPCs already exist after nuclear envelope formation, and these existing NPCs interfere with the observation of nascent NPCs. To overcome this obstacle, we developed a novel system using the cell-fusion technique (heterokaryon method), previously also used to analyze the shuttling of macromolecules between the cytoplasm and the nucleus, to visualize the newly synthesized interphase NPCs. In addition, we used a photobleaching approach that validated the cell-fusion method. We recently used these methods to demonstrate the role of cyclin-dependent protein kinases and of Pom121 in interphase NPC formation in cycling human cells. Here, we describe the details of the cell-fusion approach and compare the system with other NPC formation visualization methods.

  13. Oral cancer/endothelial cell fusion experiences nuclear fusion and acquisition of enhanced survival potential.

    PubMed

    Song, Kai; Song, Yong; Zhao, Xiao-Ping; Shen, Hui; Wang, Meng; Yan, Ting-Lin; Liu, Ke; Shang, Zheng-Jun

    2014-10-15

    Most previous studies have linked cancer-macrophage fusion with tumor progression and metastasis. However, the characteristics of hybrid cells derived from oral cancer and endothelial cells and their involvement in cancer remained unknown. Double-immunofluorescent staining and fluorescent in situ hybridization (FISH) were performed to confirm spontaneous cell fusion between eGFP-labeled human umbilical vein endothelial cells (HUVECs) and RFP-labeled SCC9, and to detect the expression of vementin and cytokeratin 18 in the hybrids. The property of chemo-resistance of such hybrids was examined by TUNEL assay. The hybrid cells in xenografted tumor were identified by FISH and GFP/RFP dual-immunofluoresence staining. We showed that SCC9 cells spontaneously fused with cocultured endothelial cells, and the resultant hybrid cells maintained the division and proliferation activity after re-plating and thawing. Such hybrids expressed markers of both parental cells and became more resistant to chemotherapeutic drug cisplatin as compared to the parental SCC9 cells. Our in vivo data indicated that the hybrid cells contributed to tumor composition by using of immunostaining and FISH analysis, even though the hybrid cells and SCC9 cells were mixed with 1:10,000, according to the FACS data. Our study suggested that the fusion events between oral cancer and endothelial cells undergo nuclear fusion and acquire a new property of drug resistance and consequently enhanced survival potential. These experimental findings provide further supportive evidence for the theory that cell fusion is involved in cancer progression.

  14. Development of an inertial confinement fusion platform to study charged-particle-producing nuclear reactions relevant to nuclear astrophysics

    DOE PAGES

    Gatu Johnson, M.; Zylstra, A. B.; Bacher, A.; ...

    2017-03-28

    Here, this paper describes the development of a platform to study astrophysically relevant nuclear reactions using inertial-confinement fusion implosions on the OMEGA and National Ignition Facility laser facilities, with a particular focus on optimizing the implosions to study charged-particle- producing reactions. Primary requirements on the platform are high yield, for high statistics in the fusion product measurements, combined with low areal density, to allow the charged fusion products to escape. This is optimally achieved with direct-drive exploding pusher implosions using thin-glass-shell capsules. Mitigation strategies to eliminate a possible target sheath potential which would accelerate the emitted ions are discussed. Themore » potential impact of kinetic effects on the implosions is also considered. The platform is initially employed to study the complementary T(t,2n)α, T(3He,np)α and 3He(3He,2p)α reactions. Proof-of-principle results from the first experiments demonstrating the ability to accurately measure the energy and yields of charged particles are presented. Lessons learned from these experiments will be used in studies of other reactions. Ultimately, the goals are to explore thermonuclear reaction rates and fundamental nuclear physics in stellarlike plasma environments, and to push this new frontier of nuclear astrophysics into unique regimes not reachable through existing platforms, with thermal ion velocity distributions, plasma screening, and low reactant energies.« less

  15. FENDL: International reference nuclear data library for fusion applications

    NASA Astrophysics Data System (ADS)

    Pashchenko, A. B.; Wienke, H.; Ganesan, S.

    1996-10-01

    The IAEA Nuclear Data Section, in co-operation with several national nuclear data centres and research groups, has created the first version of an internationally available Fusion Evaluated Nuclear Data Library (FENDL-1). The FENDL library has been selected to serve as a comprehensive source of processed and tested nuclear data tailored to the requirements of the engineering design activity (EDA) of the ITER project and other fusion-related development projects. The present version of FENDL consists of the following sublibraries covering the necessary nuclear input for all physics and engineering aspects of the material development, design, operation and safety of the ITER project in its current EDA phase: FENDL/A-1.1: neutron activation cross-sections, selected from different available sources, for 636 nuclides, FENDL/D-1.0: nuclear decay data for 2900 nuclides in ENDF-6 format, FENDL/DS-1.0: neutron activation data for dosimetry by foil activation, FENDL/C-1.0: data for the fusion reactions D(d,n), D(d,p), T(d,n), T(t,2n), He-3(d,p) extracted from ENDF/B-6 and processed, FENDL/E-1.0:data for coupled neutron—photon transport calculations, including a data library for neutron interaction and photon production for 63 elements or isotopes, selected from ENDF/B-6, JENDL-3, or BROND-2, and a photon—atom interaction data library for 34 elements. The benchmark validation of FENDL-1 as required by the customer, i.e. the ITER team, is considered to be a task of high priority in the coming months. The well tested and validated nuclear data libraries in processed form of the FENDL-2 are expected to be ready by mid 1996 for use by the ITER team in the final phase of ITER EDA after extensive benchmarking and integral validation studies in the 1995-1996 period. The FENDL data files can be electronically transferred to users from the IAEA nuclear data section online system through INTERNET. A grand total of 54 (sub)directories with 845 files with total size of about 2

  16. Charged fusion product loss measurements using nuclear activation

    SciTech Connect

    Bonheure, G.; Hult, M.; Gonzalez de Orduna, R.; Wieslander, E.; Arnold, D.; Dombrowski, H.; Laubenstein, M.; Murari, A.; Collaboration: JET-EFDA Contributors

    2010-10-15

    In ITER, {alpha} particle loss measurements will be required in order to understand the alpha particle physics. Techniques capable of operating in a fusion reactor environment need further development. Recent experimental studies on JET demonstrated the potential of nuclear activation to measure the flux of escaping MeV ions. New results from MeV ion induced activation of metallic, ceramic, and crystal samples placed near the plasma edge are reported. Activation products were measured as function of orientation with respect to the magnetic field as well as function of the distance to the plasma. Sample activity was measured using ultralow-level gamma-ray spectrometry. Distribution of 14.68 MeV fusion proton induced activation products is strongly anisotropic in agreement with simulations and falls off sharply with increasing distance to the plasma. Prospects for using the technique in ITER are discussed.

  17. Cluster dynamics transcending chemical dynamics toward nuclear fusion

    PubMed Central

    Heidenreich, Andreas; Jortner, Joshua; Last, Isidore

    2006-01-01

    Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 1015–1020 W·cm−2). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C4+(D+)4)n and (D+I22+)n at IM = 1018 W·cm−2, that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D2)n, (HT)n, (CD4)n, (DI)n, (CD3I)n, and (CH3I)n clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D2)n clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., 12C(P,γ)13N driven by CE of (CH3I)n clusters, were explored. PMID:16740666

  18. Cluster dynamics transcending chemical dynamics toward nuclear fusion.

    PubMed

    Heidenreich, Andreas; Jortner, Joshua; Last, Isidore

    2006-07-11

    Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10(15)-10(20) W.cm(-2)). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C(4+)(D(+))(4))(n) and (D(+)I(22+))(n) at I(M) = 10(18) W.cm(-2), that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D(2))(n), (HT)(n), (CD(4))(n), (DI)(n), (CD(3)I)(n), and (CH(3)I)(n) clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D(2))(n) clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., (12)C(P,gamma)(13)N driven by CE of (CH(3)I)(n) clusters, were explored.

  19. FINESSE: study of the issues, experiments and facilities for fusion nuclear technology research and development. Interim report. Volume II

    SciTech Connect

    Abdou, M.

    1984-10-01

    The Nuclear Fusion Issues chapter contains a comprehensive list of engineering issues for fusion reactor nuclear components. The list explicitly defines the uncertainties associated with the engineering option of a fusion reactor and addresses the potential consequences resulting from each issue. The next chapter identifies the fusion nuclear technology testing needs up to the engineering demonstration stage. (MOW)

  20. Tritium Plasma Experiment Upgrade for Fusion Tritium and Nuclear Sciences

    NASA Astrophysics Data System (ADS)

    Shimada, Masashi; Taylor, Chase N.; Kolasinski, Robert D.; Buchenauer, Dean A.

    2015-11-01

    The Tritium Plasma Experiment (TPE) is a unique high-flux linear plasma device that can handle beryllium, tritium, and neutron-irradiated plasma facing materials, and is the only existing device dedicated to directly study tritium retention and permeation in neutron-irradiated materials [M. Shimada et.al., Rev. Sci. Instru. 82 (2011) 083503 and and M. Shimada, et.al., Nucl. Fusion 55 (2015) 013008]. Recently the TPE has undergone major upgrades in its electrical and control systems. New DC power supplies and a new control center enable remote plasma operations from outside of the contamination area for tritium, minimizing the possible exposure risk with tritium and beryllium. We discuss the electrical upgrade, enhanced operational safety, improved plasma performance, and development of tritium plasma-driven permeation and optical spectrometer system. This upgrade not only improves operational safety of the worker, but also enhances plasma performance to better simulate extreme plasma-material conditions expected in ITER, Fusion Nuclear Science Facility (FNSF), and Demonstration reactor (DEMO). This work was prepared for the U.S. Department of Energy, Office of Fusion Energy Sciences, under the DOE Idaho Field Office contract number DE-AC07-05ID14517.

  1. Mission and Readiness Assessment for Fusion Nuclear Facilities

    SciTech Connect

    G.H. Neilson, et. al.

    2012-12-12

    Magnetic fusion development toward DEMO will most likely require a number of fusion nuclear facilities (FNF), intermediate between ITER and DEMO, to test and validate plasma and nuclear technologies and to advance the level of system integration. The FNF mission space is wide, ranging from basic materials research to net electricity demonstration, so there is correspondingly a choice among machine options, scope, and risk in planning such a step. Readiness requirements to proceed with a DEMO are examined, and two FNF options are assessed in terms of the contributions they would make to closing DEMO readiness gaps, and their readiness to themselves proceed with engineering design about ten years from now. An advanced tokamak (AT) pilot plant with superconducting coils and a mission to demonstrate net electricity generation would go a long way toward DEMO. As a next step, however, a pilot plant would entail greater risk than a copper-coil FNSF-AT with its more focussed mission and technology requirements. The stellarator path to DEMO is briefly discussed. Regardless of the choice of FNF option, an accompanying science and technology development program, also aimed at DEMO readiness, is absolutely essential.

  2. Secondary Nuclear Reactions in Magneto-Inertial Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Knapp, Patrick

    2014-10-01

    The goal of Magneto-Inertial Fusion (MIF) is to relax the extreme pressure requirements of inertial confinement fusion by magnetizing the fuel. Understanding the level of magnetization at stagnation is critical for charting the performance of any MIF concept. We show here that the secondary nuclear reactions in magnetized deuterium plasma can be used to infer the magnetic field-radius product (BR), the critical confinement parameter for MIF. The secondary neutron yields and spectra are examined and shown to be extremely sensitive to BR. In particular, embedded magnetic fields are shown to affect profoundly the isotropy of the secondary neutron spectra. Detailed modeling of these spectra along with the ratio of overall secondary to primary neutron yields is used to form the basis of a diagnostic technique used to infer BR at stagnation. Effects of gradients in density, temperature and magnetic field strength are examined, as well as other possible non-uniform fuel configurations. Computational results employing a fully kinetic treatment of charged reaction product transport and Monte Carlo treatment of secondary reactions are compared to results from recent experiments at Sandia National Laboratories' Z machine testing the MAGnetized Liner Inertial Fusion (MagLIF) concept. The technique reveals that the charged reaction products were highly magnetized in these experiments. Implications for eventual ignition-relevant experiments with deuterium-tritium fuel are discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  3. Nuclear Fusion Rate Study of a Muonic Molecule via Nuclear Threshold Resonances

    NASA Astrophysics Data System (ADS)

    Faghihi, F.; Eskandari, M. R.

    This work follows our previous calculations of the ground state binding energy, size, and the effective nuclear charge of the muonic T3 molecule, using the Born-Oppenheimer adiabatic approximation. In our past articles, we showed that the system possesses two minimum positions, the first one at the muonic distance and the second at the atomic distance. Also, the symmetric planner vibrational model assumed between the two minima and the approximated potential were calculated. Following from the previous studies, we now calculate the fusion rate of the T3 muonic molecule according to the overlap integral of the resonance nuclear compound nucleus and the molecular wave functions.

  4. Nuclear inner membrane fusion facilitated by yeast Jem1p is required for spindle pole body fusion but not for the first mitotic nuclear division during yeast mating.

    PubMed

    Nishikawa, Shuh-ichi; Hirata, Aiko; Endo, Toshiya

    2008-11-01

    During mating of budding yeast, Saccharomyces cerevisiae, two haploid nuclei fuse to produce a diploid nucleus. The process of nuclear fusion requires two J proteins, Jem1p in the endoplasmic reticulum (ER) lumen and Sec63p, which forms a complex with Sec71p and Sec72p, in the ER membrane. Zygotes of mutants defective in the functions of Jem1p or Sec63p contain two haploid nuclei that were closely apposed but failed to fuse. Here we analyzed the ultrastructure of nuclei in jem1 Delta and sec71 Delta mutant zygotes using electron microscope with the freeze-substituted fixation method. Three-dimensional reconstitution of nuclear structures from electron microscope serial sections revealed that Jem1p facilitates nuclear inner-membrane fusion and spindle pole body (SPB) fusion while Sec71p facilitates nuclear outer-membrane fusion. Two haploid SPBs that failed to fuse could duplicate, and mitotic nuclear division of the unfused haploid nuclei started in jem1 Delta and sec71 Delta mutant zygotes. This observation suggests that nuclear inner-membrane fusion is required for SPB fusion, but not for SPB duplication in the first mitotic cell division.

  5. Actinide incineration in fusion-fission hybrid-A model nuclear synergy

    NASA Astrophysics Data System (ADS)

    Taczanowski, Stefan

    2012-06-01

    The alliance of fusion with fission is a cause worthy of great efforts, as being able to ease (if not even to solve) serious problems that both these forms of nuclear energy are facing. Very high investment costs caused by tokamak enormous size, material consumption and difficult technology put in doubt whether alone the minute demand for fuel raw material (Li) and lack of danger of uncontrolled supercriticality prove sufficient for making it competitive. Preliminary evaluations demonstrated that a radical shift of energy production i.e. the energy gain from plasma to fission blanket is feasible [1]. A reduction in the fusion component to about 2% at given system power allows for a radical drop in plasma Q down to the values of ˜0.2-0.3 achievable in small systems [2] (e.g. mirrors) of sizes comparable to fission reactors. As a result in a Fusion-Driven Actinide Incinerator (FDI) both radiations from the plasma: corpuscular (i.e. neutrons and ions) and photons are drastically reduced. Thus are too, first of all - the neutron induced radiation damage: DPA and gas production, then plasma-wall interactions. The fundamental safety of the system has been proved by simulation of its collapse that has shown preservation its subcriticality. Summarizing, all the above problems may be solved with synergic union of fusion with fission embodied in the concept of FDI - small and less expensive.

  6. Survey of nuclear fusion technology. A prospect analysis of Tokamak fusion research

    NASA Astrophysics Data System (ADS)

    Hwang, W. K.

    The fusion research evaluation model for analyzing various R and D sinarios, the trend analysis of Tokamak research, and the near-term technologies are discussed. A computer code, FUSREV, was developed. It consists of the plasma power model and the cost/benefit model. Since the state-of-the-arts which are expected to be achieve as the result of subproject R and D's can only be obtained in the form of probability distribution functions Monte Carlo method is employed. The test computation of the code shows acceptable results. However, FUSREV was continuously modified employing new models for both technology and economics.

  7. High-performance superconductors for Fusion Nuclear Science Facility

    SciTech Connect

    Zhai, Yuhu; Kessel, Chuck; Barth, Christian; Senatore, Carmine

    2016-11-09

    High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steel jacket for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced JcNb3Sn RRP strands (Jc > 1000 A/mm2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.

  8. High-performance superconductors for Fusion Nuclear Science Facility

    DOE PAGES

    Zhai, Yuhu; Kessel, Chuck; Barth, Christian; ...

    2016-11-09

    High-performance superconducting magnets play an important role in the design of the next step large-scale, high-field fusion reactors such as the fusion nuclear science facility (FNSF) and the spherical tokamak (ST) pilot plant beyond ITER. Here, Princeton Plasma Physics Laboratory is currently leading the design studies of the FNSF and the ST pilot plant study. ITER, which is under construction in the south of France, utilizes the state-of-the-art low temperature superconducting magnet technology based on the cable-in-conduit conductor design, where over a thousand multifilament Nb3Sn superconducting strands are twisted together to form a high-current-carrying cable inserted into a steel jacketmore » for coil windings. We present design options of the high-performance superconductors in the winding pack for the FNSF toroidal field magnet system based on the toroidal field radial build from the system code. For the low temperature superconductor options, the advanced JcNb3Sn RRP strands (Jc > 1000 A/mm2 at 16 T, 4 K) from Oxford Superconducting Technology are under consideration. For the high-temperature superconductor options, the rectangular-shaped high-current HTS cable made of stacked YBCO tapes will be considered to validate feasibility of TF coil winding pack design for the ST-FNSF magnets.« less

  9. Achievement of Core Conditions for Alpha Heating in Direct-Drive Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Bose, A.; Woo, K. M.; Betti, R.; Mangino, D.; Christopherson, A. R.; Theobald, W.; Campbell, E. M.; McCrory, R. L.; Regan, S. P.; Goncharov, V. N.; Sangster, T. C.; Forrest, C. J.; Glebov, V. Yu.; Knauer, J. P.; Marshall, F. J.; Stoeckl, C.; Nora, R.; Frenje, J. A.; Gatu Johnson, M.; Shvarts, D.

    2016-10-01

    It is shown for the first time that direct-drive implosions on the OMEGA laser have achieved core conditions that would lead to significant alpha heating at incident energies available at the National Ignition Facility (NIF) scale. The extrapolation of the experimental results from OMEGA to NIF energy assumes only that the implosion hydrodynamic efficiency is unchanged at higher energies. This approach is independent of the uncertainties in the physical mechanism that degrade implosions on OMEGA, and relies solely on a volumetric scaling of the experimentally observed core conditions. It is estimated that the current best-performing OMEGA implosion extrapolated to a 1.9-MJ laser driver with the same illumination configuration and laser-target coupling would produce 125 kJ of fusion energy with similar levels of alpha heating observed in current highest performing indirect-drive NIF implosions. This conclusion is reached using an analytic scaling as well as direct numerical simulations of energy-scaled targets. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  10. Multi-layered nanoparticles for penetrating the endosome and nuclear membrane via a step-wise membrane fusion process.

    PubMed

    Akita, Hidetaka; Kudo, Asako; Minoura, Arisa; Yamaguti, Masaya; Khalil, Ikramy A; Moriguchi, Rumiko; Masuda, Tomoya; Danev, Radostin; Nagayama, Kuniaki; Kogure, Kentaro; Harashima, Hideyoshi

    2009-05-01

    Efficient targeting of DNA to the nucleus is a prerequisite for effective gene therapy. The gene-delivery vehicle must penetrate through the plasma membrane, and the DNA-impermeable double-membraned nuclear envelope, and deposit its DNA cargo in a form ready for transcription. Here we introduce a concept for overcoming intracellular membrane barriers that involves step-wise membrane fusion. To achieve this, a nanotechnology was developed that creates a multi-layered nanoparticle, which we refer to as a Tetra-lamellar Multi-functional Envelope-type Nano Device (T-MEND). The critical structural elements of the T-MEND are a DNA-polycation condensed core coated with two nuclear membrane-fusogenic inner envelopes and two endosome-fusogenic outer envelopes, which are shed in stepwise fashion. A double-lamellar membrane structure is required for nuclear delivery via the stepwise fusion of double layered nuclear membrane structure. Intracellular membrane fusions to endosomes and nuclear membranes were verified by spectral imaging of fluorescence resonance energy transfer (FRET) between donor and acceptor fluorophores that had been dually labeled on the liposome surface. Coating the core with the minimum number of nucleus-fusogenic lipid envelopes (i.e., 2) is essential to facilitate transcription. As a result, the T-MEND achieves dramatic levels of transgene expression in non-dividing cells.

  11. Prm3p is a pheromone-induced peripheral nuclear envelope protein required for yeast nuclear fusion.

    PubMed

    Shen, Shu; Tobery, Cynthia E; Rose, Mark D

    2009-05-01

    Nuclear membrane fusion is the last step in the mating pathway of the yeast Saccharomyces cerevisiae. We adapted a bioinformatics approach to identify putative pheromone-induced membrane proteins potentially required for nuclear membrane fusion. One protein, Prm3p, was found to be required for nuclear membrane fusion; disruption of PRM3 caused a strong bilateral defect, in which nuclear congression was completed but fusion did not occur. Prm3p was localized to the nuclear envelope in pheromone-responding cells, with significant colocalization with the spindle pole body in zygotes. A previous report, using a truncated protein, claimed that Prm3p is localized to the inner nuclear envelope. Based on biochemistry, immunoelectron microscopy and live cell microscopy, we find that functional Prm3p is a peripheral membrane protein exposed on the cytoplasmic face of the outer nuclear envelope. In support of this, mutations in a putative nuclear localization sequence had no effect on full-length protein function or localization. In contrast, point mutations and deletions in the highly conserved hydrophobic carboxy-terminal domain disrupted both protein function and localization. Genetic analysis, colocalization, and biochemical experiments indicate that Prm3p interacts directly with Kar5p, suggesting that nuclear membrane fusion is mediated by a protein complex.

  12. Dynamic assembly of brambleberry mediates nuclear envelope fusion during early development.

    PubMed

    Abrams, Elliott W; Zhang, Hong; Marlow, Florence L; Kapp, Lee; Lu, Sumei; Mullins, Mary C

    2012-08-03

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres.

  13. Nuclear Data for Fusion Energy Technologies: Requests, Status and Development Needs

    SciTech Connect

    Fischer, U.; Batistoni, P.; Cheng, E.; Forrest, R.A.

    2005-05-24

    The current status of nuclear data evaluations for fusion technologies is reviewed. Well-qualified data are available for neutronics and activation calculations of fusion power reactors and the next-step device ITER, the International Thermonuclear Experimental Reactor. Major challenges for the further development of fusion nuclear data arise from the needs of the long-term fusion programme. In particular, co-variance data are required for uncertainty assessments of nuclear responses. Further, the nuclear data libraries need to be extended to higher energies above 20 MeV to enable neutronics and activation calculations of IFMIF, the International Fusion Material Irradiation Facility. A significant experimental effort is required in this field to provide a reliable and sound database for the evaluation of cross-section data in the higher energy range.

  14. Laser Intertial Fusion Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    SciTech Connect

    Kramer, Kevin James

    2010-04-08

    of fixed fuel configurations that would normally require a computationally burdensome number of depletion zones. Alternatively, Adaptive Mesh Refinement (AMR) adjusts the depletion zone size according to the variation in flux across the zone or fractional contribution to total absorption or fission. A parametric analysis on a fully mixed fuel core was performed using the LNC and ABL code suites. The resulting system parameters are found to optimize performance metrics using a 20 MT DU fuel load with a 20% TRISO packing and a 300 μm kernel radius operated with a fusion input power of 500 MW and a fission blanket gain of 4.0. LFFH potentially offers a proliferation resistant technology relative to other nuclear energy systems primarily because of no need for fuel enrichment or reprocessing. A figure of merit of the material attractiveness is examined and it is found that the fuel is effectively contaminated to an unattractive level shortly after the system is started due to fission product and minor actinide build up.

  15. Nuclear fusion during yeast mating occurs by a three-step pathway.

    PubMed

    Melloy, Patricia; Shen, Shu; White, Erin; McIntosh, J Richard; Rose, Mark D

    2007-11-19

    In Saccharomyces cerevisiae, mating culminates in nuclear fusion to produce a diploid zygote. Two models for nuclear fusion have been proposed: a one-step model in which the outer and inner nuclear membranes and the spindle pole bodies (SPBs) fuse simultaneously and a three-step model in which the three events occur separately. To differentiate between these models, we used electron tomography and time-lapse light microscopy of early stage wild-type zygotes. We observe two distinct SPBs in approximately 80% of zygotes that contain fused nuclei, whereas we only see fused or partially fused SPBs in zygotes in which the site of nuclear envelope (NE) fusion is already dilated. This demonstrates that SPB fusion occurs after NE fusion. Time-lapse microscopy of zygotes containing fluorescent protein tags that localize to either the NE lumen or the nucleoplasm demonstrates that outer membrane fusion precedes inner membrane fusion. We conclude that nuclear fusion occurs by a three-step pathway.

  16. The Activities of the European Consortium on Nuclear Data Development and Analysis for Fusion

    SciTech Connect

    Fischer, U.; Avrigeanu, M.; Avrigeanu, V.; Cabellos, O.; Kodeli, I.; Koning, A.; Konobeyev, A.Yu.; Leeb, H.; Rochman, D.; Pereslavtsev, P.; Sauvan, P.; Sublet, J.-C.; Dupont, E.; Leichtle, D.; Izquierdo, J.

    2014-06-15

    This paper presents an overview of the activities of the European Consortium on Nuclear Data Development and Analysis for Fusion. The Consortium combines available European expertise to provide services for the generation, maintenance, and validation of nuclear data evaluations and data files relevant for ITER, IFMIF and DEMO, as well as codes and software tools required for related nuclear calculations.

  17. FINESSE: study of the issues, experiments and facilities for fusion nuclear technology research and development. Interim report. Volume III

    SciTech Connect

    Abdou, M.

    1984-10-01

    This chapter deals with the analysis and engineering scaling of solid breeded blankets. The limits under which full component behavior can be achieved under changed test conditions are explored. The characterization of these test requirements for integrated testing contributes to the overall test matrix and test plan for the understanding and development of fusion nuclear technology. The second chapter covers the analysis and engineering scaling of liquid metal blankets. The testing goals for a complete blanket program are described. (MOW)

  18. The possibilities of cold nuclear fusion of deuterium

    NASA Astrophysics Data System (ADS)

    Jin, Shangxian; Ding, Yibing; Liu, Yongzhen; Wu, Bailu; Yao, Decheng

    1990-01-01

    The possible mechanisms of deuteron-deuteron fusion during electrolytic infusion of deuterons into metallic palladium electrode are studied, and a rough estimations of the fusion rate are made. Our results show that D-D fusion rate in the equilibrium deuteron system at normal temperature and atmospheric pressure can not reach the level which can be measured experimentally.

  19. Nuclear fusion occurs during mating in Candida albicans and is dependent on the KAR3 gene.

    PubMed

    Bennett, Richard J; Miller, Mathew G; Chua, Penelope R; Maxon, Mary E; Johnson, Alexander D

    2005-02-01

    It is now well established that mating can occur between diploid a and alpha cells of Candida albicans. There is, however, controversy over when, and with what efficiency, nuclear fusion follows cell fusion to create stable tetraploid a/alpha cells. In this study, we have analysed the mating process between C. albicans strains using both cytological and genetic approaches. Using strains derived from SC5314, we used a number of techniques, including time-lapse microscopy, to demonstrate that efficient nuclear fusion occurs in the zygote before formation of the first daughter cell. Consistent with these observations, zygotes micromanipulated from mating mixes gave rise to mononuclear tetraploid cells, even when no selection for successful mating was applied to them. Mating between different clinical isolates of C. albicans revealed that while all isolates could undergo nuclear fusion, the efficiency of nuclear fusion varied in different crosses. We also show that nuclear fusion in C. albicans requires the Kar3 microtubule motor protein. Deletion of the CaKAR3 gene from both mating partners had little or no effect on zygote formation but reduced the formation of stable tetraploids more than 600-fold, as determined by quantitative mating assays. These findings demonstrate that nuclear fusion is an active process that can occur in C. albicans at high frequency to produce stable, mononucleate mating products.

  20. Chiral EFT based nuclear forces: achievements and challenges

    NASA Astrophysics Data System (ADS)

    Machleidt, R.; Sammarruca, F.

    2016-08-01

    During the past two decades, chiral effective field theory has become a popular tool to derive nuclear forces from first principles. Two-nucleon interactions have been worked out up to sixth order of chiral perturbation theory and three-nucleon forces up to fifth order. Applications of some of these forces have been conducted in nuclear few- and many-body systems—with a certain degree of success. But in spite of these achievements, we are still faced with great challenges. Among them is the issue of a proper uncertainty quantification of predictions obtained when applying these forces in ab initio calculations of nuclear structure and reactions. A related problem is the order by order convergence of the chiral expansion. We start this review with a pedagogical introduction and then present the current status of the field of chiral nuclear forces. This is followed by a discussion of representative examples for the application of chiral two- and three-body forces in the nuclear many-body system including convergence issues.

  1. Vegetative hyphal fusion and subsequent nuclear behavior in Epichloë grass endophytes.

    PubMed

    Shoji, Jun-Ya; Charlton, Nikki D; Yi, Mihwa; Young, Carolyn A; Craven, Kelly D

    2015-01-01

    Epichloë species (including the former genus Neotyphodium) are fungal symbionts of many agronomically important forage grasses, and provide their grass hosts with protection from a wide range of biotic and abiotic stresses. Epichloë species include many interspecific hybrids with allodiploid-like genomes, which may provide the potential for combined traits or recombination to generate new traits. Though circumstantial evidence suggests that such interspecific hybrids might have arisen from nuclear fusion events following vegetative hyphal fusion between different Epichloë strains, this hypothesis has not been addressed empirically. Here, we investigated vegetative hyphal fusion and subsequent nuclear behavior in Epichloë species. A majority of Epichloë strains, especially those having a sexual stage, underwent self vegetative hyphal fusion. Vegetative fusion also occurred between two hyphae from different Epichloë strains. Though Epichloë spp. are uninucleate fungi, hyphal fusion resulted in two nuclei stably sharing the same cytoplasm, which might ultimately lead to nuclear fusion. In addition, protoplast fusion experiments gave rise to uninucleate putative hybrids, which apparently had two markers, one from each parent within the same nucleus. These results are consistent with the notion that interspecific hybrids arise from vegetative hyphal fusion. However, we also discuss additional factors, such as post-hybridization selection, that may be important to explain the recognized prevalence of hybrids in Epichloë species.

  2. Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype

    PubMed Central

    Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

    2016-01-01

    Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis. PMID:27031510

  3. Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype.

    PubMed

    Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

    2016-01-01

    Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis.

  4. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    SciTech Connect

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.; Giardina, G.; Eidelman, S.; Venanzoni, G.; Battaglieri, M.; Mandaglio, G.

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  5. A fusion nuclear science facility for a fast-track path to DEMO

    DOE PAGES

    Garofalo, A. M.; Abdou, M. A.; Canik, John M.; ...

    2014-04-24

    An accelerated fusion energy development program, a fast-track approach, requires proceeding with a nuclear and materials testing program in parallel with research on burning plasmas, ITER. A Fusion Nuclear Science Facility (FNSF) would address many of the key issues that need to be addressed prior to DEMO, including breeding tritium and completing the fuel cycle, qualifying nuclear materials for high fluence, developing suitable materials for the plasma-boundary interface, and demonstrating power extraction. The Advanced Tokamak (AT) is a strong candidate for an FNSF as a consequence of its mature physics base, capability to address the key issues, and the directmore » relevance to an attractive target power plant. The standard aspect ratio provides space for a solenoid, assuring robust plasma current initiation,and for an inboard blanket, assuring robust tritium breeding ratio (TBR) >1 for FNSF tritium self-sufficiency and building of inventory needed to start up DEMO. An example design point gives a moderate sized Cu-coil device with R/a = 2.7 m/0.77 κ = 2.3, BT= 5.4 T, IP = 6.6 MA, βN = 2.75, Pfus = 127 MW. The modest bootstrap fraction of fBS = 0.55 provides an opportunity to develop steady state with sufficient current drive for adequate control. Lastly, proceeding with a FNSF in parallel with ITER provides a strong basis to begin construction of DEMO upon the achievement of Q ~ 10 in ITER.« less

  6. A fusion nuclear science facility for a fast-track path to DEMO

    SciTech Connect

    Garofalo, A. M.; Abdou, M. A.; Canik, John M.; Chan, Vincent S.; Hyatt, A. W.; Hill, D. N.; Morley, N. B.; Navratil, G. A.; Sawan, M. E.; Taylor, T. S.; Wong, C. P. C.; Wu, W.; Ying, Alice

    2014-04-24

    An accelerated fusion energy development program, a fast-track approach, requires proceeding with a nuclear and materials testing program in parallel with research on burning plasmas, ITER. A Fusion Nuclear Science Facility (FNSF) would address many of the key issues that need to be addressed prior to DEMO, including breeding tritium and completing the fuel cycle, qualifying nuclear materials for high fluence, developing suitable materials for the plasma-boundary interface, and demonstrating power extraction. The Advanced Tokamak (AT) is a strong candidate for an FNSF as a consequence of its mature physics base, capability to address the key issues, and the direct relevance to an attractive target power plant. The standard aspect ratio provides space for a solenoid, assuring robust plasma current initiation,and for an inboard blanket, assuring robust tritium breeding ratio (TBR) >1 for FNSF tritium self-sufficiency and building of inventory needed to start up DEMO. An example design point gives a moderate sized Cu-coil device with R/a = 2.7 m/0.77 κ = 2.3, BT= 5.4 T, IP = 6.6 MA, βN = 2.75, Pfus = 127 MW. The modest bootstrap fraction of fBS = 0.55 provides an opportunity to develop steady state with sufficient current drive for adequate control. Lastly, proceeding with a FNSF in parallel with ITER provides a strong basis to begin construction of DEMO upon the achievement of Q ~ 10 in ITER.

  7. Inhibition of CRM1-mediated nuclear export of transcription factors by leukemogenic NUP98 fusion proteins.

    PubMed

    Takeda, Akiko; Sarma, Nayan J; Abdul-Nabi, Anmaar M; Yaseen, Nabeel R

    2010-05-21

    NUP98 is a nucleoporin that plays complex roles in the nucleocytoplasmic trafficking of macromolecules. Rearrangements of the NUP98 gene in human leukemia result in the expression of numerous fusion oncoproteins whose effect on nucleocytoplasmic trafficking is poorly understood. The present study was undertaken to determine the effects of leukemogenic NUP98 fusion proteins on CRM1-mediated nuclear export. NUP98-HOXA9, a prototypic NUP98 fusion, inhibited the nuclear export of two known CRM1 substrates: mutated cytoplasmic nucleophosmin and HIV-1 Rev. In vitro binding assays revealed that NUP98-HOXA9 binds CRM1 through the FG repeat motif in a Ran-GTP-dependent manner similar to but stronger than the interaction between CRM1 and its export substrates. Two NUP98 fusions, NUP98-HOXA9 and NUP98-DDX10, whose fusion partners are structurally and functionally unrelated, interacted with endogenous CRM1 in myeloid cells as shown by co-immunoprecipitation. These leukemogenic NUP98 fusion proteins interacted with CRM1, Ran, and the nucleoporin NUP214 in a manner fundamentally different from that of wild-type NUP98. NUP98-HOXA9 and NUP98-DDX10 formed characteristic aggregates within the nuclei of a myeloid cell line and primary human CD34+ cells and caused aberrant localization of CRM1 to these aggregates. These NUP98 fusions caused nuclear accumulation of two transcription factors, NFAT and NFkappaB, that are regulated by CRM1-mediated export. The nuclear entrapment of NFAT and NFkappaB correlated with enhanced transcription from promoters responsive to these transcription factors. Taken together, the results suggest a new mechanism by which NUP98 fusions dysregulate transcription and cause leukemia, namely, inhibition of CRM1-mediated nuclear export with aberrant nuclear retention of transcriptional regulators.

  8. Cell fusion through a microslit between adhered cells and observation of their nuclear behavior.

    PubMed

    Wada, Ken-Ichi; Hosokawa, Kazuo; Kondo, Eitaro; Ito, Yoshihiro; Maeda, Mizuo

    2014-07-01

    This paper describes a novel cell fusion method which induces cell fusion between adhered cells through a microslit for preventing nuclear mixing. For this purpose, a microfluidic device which had ∼ 100 cell pairing structures (CPSs) making cell pairs through microslits with 2.1 ± 0.3 µm width was fabricated. After trapping NIH3T3 cells with hydrodynamic forces at the CPSs, the cells were fused through the microslit by the Sendai virus envelope method. With following timelapse observation, we discovered that the spread cells were much less susceptible to nuclear migration passing through the microslit compared with round cells, and that cytoplasmic fraction containing mitochondria was transferred through the microslit without nuclear mixing. These findings will provide an effective method for cell fusion without nuclear mixing, and will lead to an efficient method for reprograming and transdifferentiation of target cells toward regenerative medicine.

  9. ER-associated SNAREs and Sey1p mediate nuclear fusion at two distinct steps during yeast mating.

    PubMed

    Rogers, Jason V; Arlow, Tim; Inkellis, Elizabeth R; Koo, Timothy S; Rose, Mark D

    2013-12-01

    During yeast mating, two haploid nuclei fuse membranes to form a single diploid nucleus. However, the known proteins required for nuclear fusion are unlikely to function as direct fusogens (i.e., they are unlikely to directly catalyze lipid bilayer fusion) based on their predicted structure and localization. Therefore we screened known fusogens from vesicle trafficking (soluble N-ethylmaleimide-sensitive factor attachment protein receptors [SNAREs]) and homotypic endoplasmic reticulum (ER) fusion (Sey1p) for additional roles in nuclear fusion. Here we demonstrate that the ER-localized SNAREs Sec20p, Ufe1p, Use1p, and Bos1p are required for efficient nuclear fusion. In contrast, Sey1p is required indirectly for nuclear fusion; sey1Δ zygotes accumulate ER at the zone of cell fusion, causing a block in nuclear congression. However, double mutants of Sey1p and Sec20p, Ufe1p, or Use1p, but not Bos1p, display extreme ER morphology defects, worse than either single mutant, suggesting that retrograde SNAREs fuse ER in the absence of Sey1p. Together these data demonstrate that SNAREs mediate nuclear fusion, ER fusion after cell fusion is necessary to complete nuclear congression, and there exists a SNARE-mediated, Sey1p-independent ER fusion pathway.

  10. Argonne National Laboratory contributions to the International Symposium on Fusion Nuclear Technology (ISFNT)

    SciTech Connect

    Not Available

    1988-10-01

    A total of sixteen papers with authors from Argonne National Laboratory were presented at the First International Symposium on Fusion Nuclear Technology (ISFNT), held in Tokyo, Japan, in April 1988. The papers cover the results of recent investigations in blanket design and analysis, fusion neutronics, materials experiments in liquid metal corrosion and solid breeders, tritium recovery analysis, experiments and analysis for liquid metal MHD, reactor safety and economic analysis, and transient electromagnetic analysis.

  11. Conservation of proteo-lipid nuclear membrane fusion machinery during early embryogenesis.

    PubMed

    Byrne, Richard D; Veeriah, Selvaraju; Applebee, Christopher J; Larijani, Banafshé

    2014-01-01

    The fusogenic lipid diacylglycerol is essential for remodeling gamete and zygote nuclear envelopes (NE) during early embryogenesis. It is unclear whether upstream signaling molecules are likewise conserved. Here we demonstrate PLCγ and its activator SFK1, which co-operate during male pronuclear envelope formation, also promote the subsequent male and female pronuclear fusion. PLCγ and SFK1 interact directly at the fusion site leading to PLCγ activation. This is accompanied by a spatially restricted reduction of PtdIns(4,5)P2. Consequently, pronuclear fusion is blocked by PLCγ or SFK1 inhibition. These findings identify new regulators of events in the early embryo and suggest a conserved "toolkit" of fusion machinery drives successive NE fusion events during embryogenesis.

  12. Kar5p is required for multiple functions in both inner and outer nuclear envelope fusion in Saccharomyces cerevisiae.

    PubMed

    Rogers, Jason V; Rose, Mark D

    2014-12-02

    During mating in the budding yeast Saccharomyces cerevisiae, two haploid nuclei fuse via two sequential membrane fusion steps. SNAREs (i.e., soluble N-ethylmaleimide-sensitive factor attachment protein receptors) and Prm3p mediate outer nuclear membrane fusion, but the inner membrane fusogen remains unknown. Kar5p is a highly conserved transmembrane protein that localizes adjacent to the spindle pole body (SPB), mediates nuclear envelope fusion, and recruits Prm3p adjacent to the SPB. To separate Kar5p's functions, we tested localization, Prm3p recruitment, and nuclear fusion efficiency in various kar5 mutants. All domains and the conserved cysteine residues were essential for nuclear fusion. Several kar5 mutant proteins localized properly but did not mediate Prm3p recruitment; other kar5 mutant proteins localized and recruited Prm3p but were nevertheless defective for nuclear fusion, demonstrating additional functions beyond Prm3p recruitment. We identified one Kar5p domain required for SPB localization, which is dependent on the half-bridge protein Mps3p. Electron microscopy revealed a kar5 mutant that arrests with expanded nuclear envelope bridges, suggesting that Kar5p is required after outer nuclear envelope fusion. Finally, a split-GFP assay demonstrated that Kar5p localizes to both the inner and outer nuclear envelope. These insights suggest a mechanism by which Kar5p mediates inner nuclear membrane fusion.

  13. An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas

    NASA Technical Reports Server (NTRS)

    De, B. R.; Srnka, L. J.

    1978-01-01

    Consideration of the nuclear electric quadrupole terms in the expression for the fusion Coulomb barrier suggests that this electrostatic barrier may be substantially modified from that calculated under the usual plasma assumption that the nuclei are electric monopoles. This effect is a result of the nonspherical potential shape and the spatial quantization of the nuclear spins of the fully stripped ions in the presence of a magnetic field. For monopole-quadrupole fuel cycles like p-B-11, the fusion cross-section may be substantially increased at low energies if the protons are injected at a small angle relative to the confining magnetic field.

  14. Fusion nuclear science facilities and pilot plants based on the spherical tokamak

    SciTech Connect

    Menard, J. E.; Brown, T.; El-Guebaly, L.; Boyer, M.; Canik, J.; Colling, B.; Raman, R.; Wang, Z.; Zhai, Y.; Buxton, P.; Covele, B.; D’Angelo, C.; Davis, A.; Gerhardt, S.; Gryaznevich, M.; Harb, M.; Hender, T. C.; Kaye, S.; Kingham, D.; Kotschenreuther, M.; Mahajan, S.; Maingi, R.; Marriott, E.; Meier, E. T.; Mynsberge, L.; Neumeyer, C.; Ono, M.; Park, J. -K.; Sabbagh, S. A.; Soukhanovskii, V.; Valanju, P.; Woolley, R.

    2016-08-16

    Here, a fusion nuclear science facility (FNSF) could play an important role in the development of fusion energy by providing the nuclear environment needed to develop fusion materials and components. The spherical torus/tokamak (ST) is a leading candidate for an FNSF due to its potentially high neutron wall loading and modular configuration. A key consideration for the choice of FNSF configuration is the range of achievable missions as a function of device size. Possible missions include: providing high neutron wall loading and fluence, demonstrating tritium self-sufficiency, and demonstrating electrical self-sufficiency. All of these missions must also be compatible with a viable divertor, first-wall, and blanket solution. ST-FNSF configurations have been developed simultaneously incorporating for the first time: (1) a blanket system capable of tritium breeding ratio TBR ≈ 1, (2) a poloidal field coil set supporting high elongation and triangularity for a range of internal inductance and normalized beta values consistent with NSTX/NSTX-U previous/planned operation, (3) a long-legged divertor analogous to the MAST-U divertor which substantially reduces projected peak divertor heat-flux and has all outboard poloidal field coils outside the vacuum chamber and superconducting to reduce power consumption, and (4) a vertical maintenance scheme in which blanket structures and the centerstack can be removed independently. Progress in these ST-FNSF missions versus configuration studies including dependence on plasma major radius R 0 for a range 1 m–2.2 m are described. In particular, it is found the threshold major radius for TBR = 1 is ${{R}_{0}}\\geqslant 1.7$ m, and a smaller R 0 = 1 m ST device has TBR ≈ 0.9 which is below unity but substantially reduces T consumption relative to not breeding. Calculations of neutral beam heating and current drive for non-inductive ramp-up and sustainment are described. An A = 2, R = 3 m device incorporating high

  15. Fusion nuclear science facilities and pilot plants based on the spherical tokamak

    NASA Astrophysics Data System (ADS)

    Menard, J. E.; Brown, T.; El-Guebaly, L.; Boyer, M.; Canik, J.; Colling, B.; Raman, R.; Wang, Z.; Zhai, Y.; Buxton, P.; Covele, B.; D'Angelo, C.; Davis, A.; Gerhardt, S.; Gryaznevich, M.; Harb, M.; Hender, T. C.; Kaye, S.; Kingham, D.; Kotschenreuther, M.; Mahajan, S.; Maingi, R.; Marriott, E.; Meier, E. T.; Mynsberge, L.; Neumeyer, C.; Ono, M.; Park, J.-K.; Sabbagh, S. A.; Soukhanovskii, V.; Valanju, P.; Woolley, R.

    2016-10-01

    A fusion nuclear science facility (FNSF) could play an important role in the development of fusion energy by providing the nuclear environment needed to develop fusion materials and components. The spherical torus/tokamak (ST) is a leading candidate for an FNSF due to its potentially high neutron wall loading and modular configuration. A key consideration for the choice of FNSF configuration is the range of achievable missions as a function of device size. Possible missions include: providing high neutron wall loading and fluence, demonstrating tritium self-sufficiency, and demonstrating electrical self-sufficiency. All of these missions must also be compatible with a viable divertor, first-wall, and blanket solution. ST-FNSF configurations have been developed simultaneously incorporating for the first time: (1) a blanket system capable of tritium breeding ratio TBR  ≈  1, (2) a poloidal field coil set supporting high elongation and triangularity for a range of internal inductance and normalized beta values consistent with NSTX/NSTX-U previous/planned operation, (3) a long-legged divertor analogous to the MAST-U divertor which substantially reduces projected peak divertor heat-flux and has all outboard poloidal field coils outside the vacuum chamber and superconducting to reduce power consumption, and (4) a vertical maintenance scheme in which blanket structures and the centerstack can be removed independently. Progress in these ST-FNSF missions versus configuration studies including dependence on plasma major radius R 0 for a range 1 m-2.2 m are described. In particular, it is found the threshold major radius for TBR  =  1 is {{R}0}≥slant 1.7 m, and a smaller R 0  =  1 m ST device has TBR  ≈  0.9 which is below unity but substantially reduces T consumption relative to not breeding. Calculations of neutral beam heating and current drive for non-inductive ramp-up and sustainment are described. An A  =  2, R 0

  16. Fusion nuclear science facilities and pilot plants based on the spherical tokamak

    DOE PAGES

    Menard, J. E.; Brown, T.; El-Guebaly, L.; ...

    2016-08-16

    Here, a fusion nuclear science facility (FNSF) could play an important role in the development of fusion energy by providing the nuclear environment needed to develop fusion materials and components. The spherical torus/tokamak (ST) is a leading candidate for an FNSF due to its potentially high neutron wall loading and modular configuration. A key consideration for the choice of FNSF configuration is the range of achievable missions as a function of device size. Possible missions include: providing high neutron wall loading and fluence, demonstrating tritium self-sufficiency, and demonstrating electrical self-sufficiency. All of these missions must also be compatible with a viable divertor, first-wall, and blanket solution. ST-FNSF configurations have been developed simultaneously incorporating for the first time: (1) a blanket system capable of tritium breeding ratio TBR ≈ 1, (2) a poloidal field coil set supporting high elongation and triangularity for a range of internal inductance and normalized beta values consistent with NSTX/NSTX-U previous/planned operation, (3) a long-legged divertor analogous to the MAST-U divertor which substantially reduces projected peak divertor heat-flux and has all outboard poloidal field coils outside the vacuum chamber and superconducting to reduce power consumption, and (4) a vertical maintenance scheme in which blanket structures and the centerstack can be removed independently. Progress in these ST-FNSF missions versus configuration studies including dependence on plasma major radius R 0 for a range 1 m–2.2 m are described. In particular, it is found the threshold major radius for TBR = 1 ismore » $${{R}_{0}}\\geqslant 1.7$$ m, and a smaller R 0 = 1 m ST device has TBR ≈ 0.9 which is below unity but substantially reduces T consumption relative to not breeding. Calculations of neutral beam heating and current drive for non-inductive ramp-up and sustainment are described. An A = 2, R = 3 m device incorporating high

  17. Tate Medal for International Leadership in Physics Talk: Nuclear Fusion Power: Are we really serious about our future?

    NASA Astrophysics Data System (ADS)

    Voss, Gustav-Adolf

    2010-02-01

    There's a frantic search under way for new energy sources that do not damage global climate. In the public discussion of this subject, nuclear fusion is hardly ever mentioned. Yet nuclear fusion is the answer to the problem. It's the best way to generate large amounts of baseload power, needed in the intermediate and far future. The long-standing joke about fusion always being ``just 50 years away'' illustrates the unfavourable attitude most people have towards fusion technology, and while this is understandable in the light of fusion's history, it is unwarranted. We need a strong international effort to develop this energy source to help avoid climate change turning into global disaster. )

  18. Nuclear export of the glucocorticoid receptor is accelerated by cell fusion-dependent release of calreticulin.

    PubMed

    Walther, Rhian F; Lamprecht, Claudia; Ridsdale, Andrew; Groulx, Isabelle; Lee, Stephen; Lefebvre, Yvonne A; Haché, Robert J G

    2003-09-26

    Nucleocytoplasmic exchange of nuclear hormone receptors is hypothesized to allow for rapid and direct interactions with cytoplasmic signaling factors. In addition to recycling between a naïve, chaperone-associated cytoplasmic complex and a liganded chaperone-free nuclear form, the glucocorticoid receptor (GR) has been observed to shuttle between nucleus and cytoplasm. Nuclear export of GR and other nuclear receptors has been proposed to depend on direct interactions with calreticulin, which is predominantly localized to the lumen of the endoplasmic reticulum. We show that rapid calreticulin-mediated nuclear export of GR is a specific response to transient disruption of the endoplasmic reticulum that occurs during polyethylene glycol-mediated cell fusion. Using live and digitonin-permeabilized cells we demonstrate that, in the absence of cell fusion, GR nuclear export occurs slowly over a period of many hours independent of direct interaction with calreticulin. Our findings temper expectations that nuclear receptors respond rapidly and directly to cytoplasmic signals in the absence of additional regulatory control. These results highlight the importance of verifying findings of nucleocytoplasmic trafficking using techniques in addition to heterokaryon cell fusion.

  19. Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.; Dudzinski, Leonard A.; Borowski, Stanley K.; Juhasz, Albert J.

    2005-01-01

    A conceptual vehicle design enabling fast, piloted outer solar system travel was created predicated on a small aspect ratio spherical torus nuclear fusion reactor. The initial requirements were satisfied by the vehicle concept, which could deliver a 172 mt crew payload from Earth to Jupiter rendezvous in 118 days, with an initial mass in low Earth orbit of 1,690 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including artificial gravity payload, central truss, nuclear fusion reactor, power conversion, magnetic nozzle, fast wave plasma heating, tankage, fuel pellet injector, startup/re-start fission reactor and battery bank, refrigeration, reaction control, communications, mission design, and space operations. Detailed fusion reactor design included analysis of plasma characteristics, power balance/utilization, first wall, toroidal field coils, heat transfer, and neutron/x-ray radiation. Technical comparisons are made between the vehicle concept and the interplanetary spacecraft depicted in the motion picture 2001: A Space Odyssey.

  20. Hybrid fusion reactor for production of nuclear fuel with minimum radioactive contamination of the fuel cycle

    SciTech Connect

    Velikhov, E. P.; Kovalchuk, M. V.; Azizov, E. A. Ignatiev, V. V.; Subbotin, S. A. Tsibulskiy, V. F.

    2015-12-15

    The paper presents the results of the system research on the coordinated development of nuclear and fusion power engineering in the current century. Considering the increasing problems of resource procurement, including limited natural uranium resources, it seems reasonable to use fusion reactors as high-power neutron sources for production of nuclear fuel in a blanket. It is shown that the share of fusion sources in this structural configuration of the energy system can be relatively small. A fundamentally important aspect of this solution to the problem of closure of the fuel cycle is that recycling of highly active spent fuel can be abandoned. Radioactivity released during the recycling of the spent fuel from the hybrid reactor blanket is at least two orders of magnitude lower than during the production of the same number of fissile isotopes after the recycling of the spent fuel from a fast reactor.

  1. Hybrid fusion reactor for production of nuclear fuel with minimum radioactive contamination of the fuel cycle

    NASA Astrophysics Data System (ADS)

    Velikhov, E. P.; Kovalchuk, M. V.; Azizov, E. A.; Ignatiev, V. V.; Subbotin, S. A.; Tsibulskiy, V. F.

    2015-12-01

    The paper presents the results of the system research on the coordinated development of nuclear and fusion power engineering in the current century. Considering the increasing problems of resource procurement, including limited natural uranium resources, it seems reasonable to use fusion reactors as high-power neutron sources for production of nuclear fuel in a blanket. It is shown that the share of fusion sources in this structural configuration of the energy system can be relatively small. A fundamentally important aspect of this solution to the problem of closure of the fuel cycle is that recycling of highly active spent fuel can be abandoned. Radioactivity released during the recycling of the spent fuel from the hybrid reactor blanket is at least two orders of magnitude lower than during the production of the same number of fissile isotopes after the recycling of the spent fuel from a fast reactor.

  2. Apparatus and method for extracting power from energetic ions produced in nuclear fusion

    DOEpatents

    Fisch, N.J.; Rax, J.M.

    1994-12-20

    An apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor. 4 figures.

  3. Apparatus and method for extracting power from energetic ions produced in nuclear fusion

    DOEpatents

    Fisch, Nathaniel J.; Rax, Jean M.

    1994-01-01

    An apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor.

  4. 1991 US-Japan workshop on Nuclear Fusion in Dense Plasmas

    SciTech Connect

    Ichimaru, S. . Dept. of Physics); Tajima, T. . Inst. for Fusion Studies)

    1991-10-01

    The scientific areas covered at the Workshop may be classified into the following subfields: (1) basic theory of dense plasma physics and its interface with atomic physics and nuclear physics; (2) physics of dense z-pinches, ICF plasmas etc; (3) stellar interior plasmas; (4) cold fusion; and (5) other dense plasmas.

  5. 1991 US-Japan workshop on Nuclear Fusion in Dense Plasmas. Proceedings

    SciTech Connect

    Ichimaru, S.; Tajima, T.

    1991-10-01

    The scientific areas covered at the Workshop may be classified into the following subfields: (1) basic theory of dense plasma physics and its interface with atomic physics and nuclear physics; (2) physics of dense z-pinches, ICF plasmas etc; (3) stellar interior plasmas; (4) cold fusion; and (5) other dense plasmas.

  6. A fusion-driven gas core nuclear rocket

    NASA Astrophysics Data System (ADS)

    Kammash, T.; Godfroy, T.

    1998-01-01

    A magnetic confinement scheme is investigated as a potential propulsion device in which thrust is generated by a propellant heated by radiation emanating from a fusion plasma. The device in question is the gasdynamic mirror (GDM) machine in which a hot dense plasma is confined long enough to generate fusion energy while allowing a certain fraction of its charged particle population to go through one end to a direct converter. The energy of these particles is converted into electric power which is recirculated to sustain the steady state operation of the system. The injected power heats the plasma to thermonuclear temperatures where the resulting fusion energy appears a charged particle power, neutron power, and radiated power in the form of bremsstrahlung and synchrotron radiation. The neutron power can be converted through a thermal converter to electric power that can be combined with the direct converter power before being fed into the injector. The radiated power, on the other hand, can be used to heat a hydrogen propellant introduced into the system at a specified pressure and mass flow rate. This propellant can be pre-heated by regeneratively cooling the (mirror) nozzle or other components of the system if feasible, or by an electrothermal unit powered by portions of the recirculated power. Using a simple heat transfer model that ignores the heat flux to the wall, and assuming total absorption of radiation energy by the propellant it is shown that such a gas core rocket is capable of producing tens of kilonewtons of thrust and several thousands of seconds of specific impulse. It is also shown that the familiar Kelvin-Helmholtz instability which arises from the relative motion of the neutral hydrogen to the ionized fuel is not likely to occur in this system due to the presence of the confining magnetic field.

  7. To the non-local theory of cold nuclear fusion.

    PubMed

    Alexeev, Boris V

    2014-10-01

    In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the 'acoustic CF' could be realized from the position of the non-local hydrodynamics.

  8. Nuclear fusion reaction rates for strongly coupled ionic mixtures

    SciTech Connect

    Chugunov, A. I.; DeWitt, H. E.

    2009-07-15

    We analyze the effect of plasma screening on nuclear reaction rates in dense matter composed of atomic nuclei of one or two types. We perform semiclassical calculations of the Coulomb barrier penetrability taking into account a radial mean-field potential of plasma ions. The mean-field potential is extracted from the results of extensive Monte Carlo calculations of radial pair distribution functions of ions in binary ionic mixtures. We calculate the reaction rates in a wide range of plasma parameters and approximate these rates by an analytical expression that is expected to be applicable to multicomponent ion mixtures. Also, we analyze Gamow-peak energies of reacting ions in various nuclear burning regimes. For illustration, we study nuclear burning in {sup 12}C-{sup 16}O mixtures.

  9. Autophagy contributes to regulation of nuclear dynamics during vegetative growth and hyphal fusion in Fusarium oxysporum.

    PubMed

    Corral-Ramos, Cristina; Roca, M Gabriela; Di Pietro, Antonio; Roncero, M Isabel G; Ruiz-Roldán, Carmen

    2015-01-01

    In the fungal pathogen Fusarium oxysporum, vegetative hyphal fusion triggers nuclear mitotic division in the invading hypha followed by migration of a nucleus into the receptor hypha and degradation of the resident nucleus. Here we examined the role of autophagy in fusion-induced nuclear degradation. A search of the F. oxysporum genome database for autophagy pathway components identified putative orthologs of 16 core autophagy-related (ATG) genes in yeast, including the ubiquitin-like protein Atg8, which is required for the formation of autophagosomal membranes. F. oxysporum Foatg8Δ mutants were generated in a strain harboring H1-cherry fluorescent protein (ChFP)-labeled nuclei to facilitate analysis of nuclear dynamics. The Foatg8Δ mutants did not show MDC-positive staining in contrast to the wild type and the FoATG8-complemented (cFoATG8) strain, suggesting that FoAtg8 is required for autophagy in F. oxysporum. The Foatg8Δ strains displayed reduced rates of hyphal growth, conidiation, and fusion, and were significantly attenuated in virulence on tomato plants and in the nonvertebrate animal host Galleria mellonella. In contrast to wild-type hyphae, which are almost exclusively composed of uninucleated hyphal compartments, the hyphae of the Foatg8Δ mutants contained a significant fraction of hyphal compartments with 2 or more nuclei. The increase in the number of nuclei per hyphal compartment was particularly evident after hyphal fusion events. Time-lapse microscopy analyses revealed abnormal mitotic patterns during vegetative growth in the Foatg8Δ mutants. Our results suggest that autophagy mediates nuclear degradation after hyphal fusion and has a general function in the control of nuclear distribution in F. oxysporum.

  10. 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.

  11. Application of Recommended Design Practices for Conceptual Nuclear Fusion Space Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2004-01-01

    An AIAA Special Project Report was recently produced by AIAA's Nuclear and Future Flight Propulsion Technical Committee and is currently in peer review. The Report provides recommended design practices for conceptual engineering studies of nuclear fusion space propulsion systems. Discussion and recommendations are made on key topics including design reference missions, degree of technological extrapolation and concomitant risk, thoroughness in calculating mass properties (nominal mass properties, weight-growth contingency and propellant margins, and specific impulse), and thoroughness in calculating power generation and usage (power-flow, power contingencies, specific power). The report represents a general consensus of the nuclear fusion space propulsion system conceptual design community and proposes 15 recommendations. This paper expands on the Report by providing specific examples illustrating how to apply each of the recommendations.

  12. To the non-local theory of cold nuclear fusion

    PubMed Central

    Alexeev, Boris V.

    2014-01-01

    In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the ‘acoustic CF’ could be realized from the position of the non-local hydrodynamics. PMID:26064528

  13. Ion traps in nuclear physics-Recent results and achievements

    NASA Astrophysics Data System (ADS)

    Eronen, Tommi; Kankainen, Anu; Äystö, Juha

    2016-11-01

    Ion traps offer a way to determine nuclear binding energies through atomic mass measurements with a high accuracy and they are routinely used to provide isotopically or even isomerically pure beams of short-living ions for post-trap decay spectroscopy experiments. In this review, different ion-trapping techniques and progresses in recent nuclear physics experiments employing low-energy ion traps are discussed. The main focus in this review is on the benefit of recent high accuracy mass measurements to solve some key problems in physics related to nuclear structure, nuclear astrophysics as well as neutrinos. Also, several cases of decay spectroscopy experiments utilizing trap-purified ion samples are summarized.

  14. Nuclear dynamics during germination, conidiation, and hyphal fusion of Fusarium oxysporum.

    PubMed

    Ruiz-Roldán, M Carmen; Köhli, Michael; Roncero, M Isabel G; Philippsen, Peter; Di Pietro, Antonio; Espeso, Eduardo A

    2010-08-01

    In many fungal pathogens, infection is initiated by conidial germination. Subsequent stages involve germ tube elongation, conidiation, and vegetative hyphal fusion (anastomosis). Here, we used live-cell fluorescence to study the dynamics of green fluorescent protein (GFP)- and cherry fluorescent protein (ChFP)-labeled nuclei in the plant pathogen Fusarium oxysporum. Hyphae of F. oxysporum have uninucleated cells and exhibit an acropetal nuclear pedigree, where only the nucleus in the apical compartment is mitotically active. In contrast, conidiation follows a basopetal pattern, whereby mononucleated microconidia are generated by repeated mitotic cycles of the subapical nucleus in the phialide, followed by septation and cell abscission. Vegetative hyphal fusion is preceded by directed growth of the fusion hypha toward the receptor hypha and followed by a series of postfusion nuclear events, including mitosis of the apical nucleus of the fusion hypha, migration of a daughter nucleus into the receptor hypha, and degradation of the resident nucleus. These previously unreported patterns of nuclear dynamics in F. oxysporum could be intimately related to its pathogenic lifestyle.

  15. Sub-Barrier Fusion in the HI + 208Pb Systems and Nuclear Potentials for Cluster Decay

    SciTech Connect

    Sagaidak, R.N.; Tretyakova, S.P.; Khlebnikov, S.V.; Ogloblin, A.A.; Rowley, N.

    2005-11-21

    Near-barrier fusion excitation functions for the 12,14C, 16,18O + 208Pb reactions have been analyzed in the framework of the barrier-passing model using different forms of the nuclear potential and the phenomenology of a fluctuating barrier. The best-fit fusion potentials were used to estimate cluster decay probabilities from the corresponding ground states of Ra and Th, i.e., for the inverse decay process. The analysis supports the 'alpha-decay-like' scenario for carbon and oxygen emission from these nuclei.

  16. Mitochondrial Fusion Is Increased by the Nuclear Coactivator PGC-1β

    PubMed Central

    Liesa, Marc; Borda-d'Água, Bárbara; Medina-Gómez, Gema; Lelliott, Christopher J.; Paz, José Carlos; Rojo, Manuel; Palacín, Manuel; Vidal-Puig, Antonio; Zorzano, Antonio

    2008-01-01

    Background There is no evidence to date on whether transcriptional regulators are able to shift the balance between mitochondrial fusion and fission events through selective control of gene expression. Methodology/Principal Findings Here, we demonstrate that reduced mitochondrial size observed in knock-out mice for the transcriptional regulator PGC-1β is associated with a selective reduction in Mitofusin 2 (Mfn2) expression, a mitochondrial fusion protein. This decrease in Mfn2 is specific since expression of the remaining components of mitochondrial fusion and fission machinery were not affected. Furthermore, PGC-1β increases mitochondrial fusion and elongates mitochondrial tubules. This PGC-1β-induced elongation specifically requires Mfn2 as this process is absent in Mfn2-ablated cells. Finally, we show that PGC-1β increases Mfn2 promoter activity and transcription by coactivating the nuclear receptor Estrogen Related Receptor α (ERRα). Conclusions/Significance Taken together, our data reveal a novel mechanism by which mammalian cells control mitochondrial fusion. In addition, we describe a novel role of PGC-1β in mitochondrial physiology, namely the control of mitochondrial fusion mainly through Mfn2. PMID:18974884

  17. Low-energy nuclear fusion data and their relation to magnetic and laser fusion

    SciTech Connect

    Jarmie, N.

    1980-04-01

    The accuracy of the basic fusion data for the T(d,n)/sup 4/He, /sup 3/He(d,p)/sup 4/He, T(t,2n)/sup 4/He, D(d,n)/sup 3/He, and D(d,p)T reactions was investigated in the 10- to 100-keV bombarding energy region, and the effects of inaccuracies on the design of fusion reactors were assessed. The data base for these reactions (particularly, the most critical T(d,n)/sup 4/He reaction) rests on 25-year-old experiments the accuracy (often assumed to be +- 5%) of which has rarely been questioned: yet, in all except the d + d reactions, there are significant differences among data sets. The errors in the basic data sets may be considerably larger than previously expected, and the effect on design calculations should be significant. Much of the trouble apparently lies in the accuracy of the energy measurements, which are difficult at low energies. Systematic errors of up to 50% are possible in the reactivity values of the present T(d,n)/sup 4/He data base. The errors in the reactivity will propagate proportionately into the errors in fusion probabilities in reactor calculations. /sup 3/He(d,p)/sup 4/He reaction cross sections could be in error by as much as 50% in the low-energy region. The D(d,n)/sup 3/He and D(d,p)T cross sections appear to be well known and consistent. The T(t,2n)/sup 4/He cross section is poorly known and may be subject to large systematic errors. Improved absolute measurements for all the reactions in the low bombarding energy region (10 to 100 keV) are needed, but until they are done, the data sets should be left as they are (except for T(t,2n)/sup 4/He data, which could be lowered by about 50%). The apparent uncertainties of these data sets should be kept in mind. 14 figures.

  18. The Sustainable Nuclear Future: Fission and Fusion E.M. Campbell Logos Technologies

    NASA Astrophysics Data System (ADS)

    Campbell, E. Michael

    2010-02-01

    Global industrialization, the concern over rising CO2 levels in the atmosphere and other negative environmental effects due to the burning of hydrocarbon fuels and the need to insulate the cost of energy from fuel price volatility have led to a renewed interest in nuclear power. Many of the plants under construction are similar to the existing light water reactors but incorporate modern engineering and enhanced safety features. These reactors, while mature, safe and reliable sources of electrical power have limited efficiency in converting fission power to useful work, require significant amounts of water, and must deal with the issues of nuclear waste (spent fuel), safety, and weapons proliferation. If nuclear power is to sustain its present share of the world's growing energy needs let alone displace carbon based fuels, more than 1000 reactors will be needed by mid century. For this to occur new reactors that are more efficient, versatile in their energy markets, require minimal or no water, produce less waste and more robust waste forms, are inherently safe and minimize proliferation concerns will be necessary. Graphite moderated, ceramic coated fuel, and He cooled designs are reactors that can satisfy these requirements. Along with other generation IV fast reactors that can further reduce the amounts of spent fuel and extend fuel resources, such a nuclear expansion is possible. Furthermore, facilities either in early operations or under construction should demonstrate the next step in fusion energy development in which energy gain is produced. This demonstration will catalyze fusion energy development and lead to the ultimate development of the next generation of nuclear reactors. In this presentation the role of advanced fission reactors and future fusion reactors in the expansion of nuclear power will be discussed including synergies with the existing worldwide nuclear fleet. )

  19. Nuclear fusion and carbon flashes on neutron stars

    NASA Technical Reports Server (NTRS)

    Taam, R. E.; Picklum, R. E.

    1978-01-01

    This paper reports on detailed calculations of the thermal evolution of the carbon-burning shells in the envelopes of accreting neutron stars for mass-accretion rates of 1 hundred-billionth to 2 billionths of a solar mass per yr and neutron-star masses of 0.56 and 1.41 solar masses. The work of Hansen and Van Horn (1975) is extended to higher densities, and a more detailed treatment of nuclear processing in the hydrogen- and helium-burning regions is included. Results of steady-state calculations are presented, and results of time-dependent computations are examined for accretion rates of 3 ten-billionths and 1 billionth of solar mass per yr. It is found that two evolutionary sequences lead to carbon flashes and that the carbon abundance at the base of the helium shell is a strong function of accretion rate. Upper limits are placed on the accretion rates at which carbon flashes will be important.

  20. Discourse, Power, and Knowledge in the Management of "Big Science": The Production of Consensus in a Nuclear Fusion Research Laboratory.

    ERIC Educational Resources Information Center

    Kinsella, William J.

    1999-01-01

    Extends a Foucauldian view of power/knowledge to the archetypical knowledge-intensive organization, the scientific research laboratory. Describes the discursive production of power/knowledge at the "big science" laboratory conducting nuclear fusion research and illuminates a critical incident in which the fusion research…

  1. 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.

  2. Laser inertial fusion-based energy: Neutronic design aspects of a hybrid fusion-fission nuclear energy system

    NASA Astrophysics Data System (ADS)

    Kramer, Kevin James

    . Alternatively, Adaptive Mesh Refinement (AMR) adjusts the depletion zone size according to the variation in flux across the zone or fractional contribution to total absorption or fission. A parametric analysis on a fully mixed fuel core was performed using the LNC and ABL code suites. The resulting system parameters are found to optimize performance metrics using a 20 MT DU fuel load with a 20% TRISO packing and a 300 im kernel diameter operated with a fusion input power of 500 MW and a fission blanket gain of 4.0. LFFH potentially offers a proliferation resistant technology relative to other nuclear energy systems primarily because of no need for fuel enrichment or reprocessing. A figure of merit of the material attractiveness is examined and it is found that the fuel is effectively contaminated to an unattractive level shortly after the system is started due to fission product and minor actinide build up.

  3. ``Cold nuclear fusion'': A hypothetical model to probe an elusive phenomenon

    NASA Astrophysics Data System (ADS)

    Bush, Robert T.; Eagleton, Robert D.

    1990-12-01

    The natural tendency of identical bosons to clump in ordinary space is ascribed to a “symmetry force,” whose action is equivalent to the effects of the wavefunction for a collection of degenerate bosons. The symmetry force is hypothesized to produce clusters of deuterons in the lattice for a high enough stoichiometric ratio of deuterons to Pd atoms and to catalyze tunneling to achieve cold fusion. A semiempirical power law is derived as a function of the number of deuterons, N, in a representative cluster: for large enough N the fusion products are He4 plus heat, while for small clusters the fusion rate is much lower and the Oppenheimer-Phillips process favors the production of tritium over neutrons. Pulsed production of heat and neutrons is suggested. Finally, three additional roles in physics for the symmetry force are hypothesized.

  4. Accuracy and convergence of coupled finite-volume/Monte Carlo codes for plasma edge simulations of nuclear fusion reactors

    SciTech Connect

    Ghoos, K.; Dekeyser, W.; Samaey, G.; Börner, P.; Baelmans, M.

    2016-10-01

    The plasma and neutral transport in the plasma edge of a nuclear fusion reactor is usually simulated using coupled finite volume (FV)/Monte Carlo (MC) codes. However, under conditions of future reactors like ITER and DEMO, convergence issues become apparent. This paper examines the convergence behaviour and the numerical error contributions with a simplified FV/MC model for three coupling techniques: Correlated Sampling, Random Noise and Robbins Monro. Also, practical procedures to estimate the errors in complex codes are proposed. Moreover, first results with more complex models show that an order of magnitude speedup can be achieved without any loss in accuracy by making use of averaging in the Random Noise coupling technique.

  5. Analysis of nuclear export using photoactivatable GFP fusion proteins and interspecies heterokaryons.

    PubMed

    Nakrieko, Kerry-Ann; Ivanova, Iordanka A; Dagnino, Lina

    2010-01-01

    In this chapter, we review protocols for the analysis of nucleocytoplasmic shuttling of transcription factors and nuclear proteins, using two different approaches. The first involves the use of photoactivatable forms of the protein of interest by fusion to photoactivatable green fluorescent protein to follow its movement out of the nucleus by live-cell confocal microscopy. This methodology allows for the kinetic characterization of protein movements as well as measurement of steady-state levels. In a second procedure to assess the ability of a nuclear protein to move into and out of the nucleus, we describe the use of interspecies heterokaryon assays, which provide a measurement of steady-state distribution. These technologies are directly applicable to the analysis of nucleocytoplasmic movements not only of transcription factors, but also other nuclear proteins.

  6. A short analysis of new nuclear data evaluations and their impact on nuclear responses in fusion structural materials

    SciTech Connect

    Gomes, I.C.; Smith, D.L.; Cheng, E.T.

    1998-08-01

    Current emphasis in the design of fusion reactor systems entails meeting the objective of having radiation resistant materials with low-activation characteristics. Therefore, the reactors will have a long usable lifetime and, once they are decommissioned, these facilities will not present serious waste-disposal problems due to the presence of long-lived radioactive byproducts generated in the high-neutron-intensity environments encountered during their operation. A reliable estimation of the performance of a fusion reactor in this context requires accurate knowledge of half lives and neutron-reaction cross sections. A large number of materials, reactions, and radioactive byproducts must be considered. For the most part, the half lives of the radioactive species involved are reasonably well known. Therefore, the main emphasis in improving of the data base needs to be in the area of cross sections. This paper focuses on only two nuclear data issues concerning recent evaluations of cross sections: hydrogen production in vanadium from the {sup 51}V(n,p){sup 51}Ti and {sup 51}V(n,np+d){sup 50}Ti reactions and the production of 7.4 e + 05 y {sup 26}Al (a major waste-disposal concern). Al-26 can be generated mainly by the {sup 27}Al(n,2n){sup 26}Al, and {sup 28}Si(n,np+d){sup 27}Al(n,2n){sup 26}Al reaction processes. The current status and quality of the evaluated cross sections related to these nuclear-reaction processes is examined and the impact on generation of hydrogen gas and {sup 26}Al radioactive in fusion reactors is assessed in the present study.

  7. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins.

    PubMed

    Maric, Martina; Haugo, Alison C; Dauer, William; Johnson, David; Roller, Richard J

    2014-07-01

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway.

  8. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins

    SciTech Connect

    Maric, Martina; Haugo, Alison C.; Dauer, William; Johnson, David; Roller, Richard J.

    2014-07-15

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. - Highlights: • We show that wild-type HSV can induce breakdown of the nuclear envelope in a specific cell system. • The viral fusion proteins gB and gH are required for induction of nuclear envelope breakdown. • Nuclear envelope breakdown cannot compensate for deletion of the HSV UL34 gene.

  9. Revitalizing Fusion via Fission Fusion

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2001-10-01

    Existing tokamaks could generate significant nuclear fuel. TFTR, operating steady state with DT might generate enough fuel for a 300 MW nuclear reactor. The immediate goals of the magnetic fusion program would necessarily shift from a study of advanced plasma regimes in larger sized devices, to mostly known plasmas regimes, but at steady state or high duty cycle operation in DT plasmas. The science and engineering of breeding blankets would be equally important. Follow on projects could possibly produce nuclear fuel in large quantity at low price. Although today there is strong opposition to nuclear power in the United States, in a 21st century world of 10 billion people, all of whom will demand a middle class life style, nuclear energy will be important. Concern over greenhouse gases will also drive the world toward nuclear power. There are studies indicating that the world will need 10 TW of carbon free energy by 2050. It is difficult to see how this can be achieved without the breeding of nuclear fuel. By using the thorium cycle, proliferation risks are minimized. [1], [2]. 1 W. Manheimer, Fusion Technology, 36, 1, 1999, 2.W. Manheimer, Physics and Society, v 29, #3, p5, July, 2000

  10. Comparative studies of Coulomb barrier heights for nuclear models applied to sub-barrier fusion

    NASA Astrophysics Data System (ADS)

    Qu, W. W.; Zhang, G. L.; Zhang, H. Q.; Wolski, R.

    2014-12-01

    Coulomb barrier heights provided by different nuclear interaction models including the Bass model, the proximity potential model, and the double folding model have been applied for experimental data of fusion in terms of a recently proposed energy scaling approach. The results show that the proximity potential description of the barrier heights seems to be closest to the values required by the systematics. It is suggested that the proximity potential model is the most suitable model to calculate the barrier height. However, the double folding model gives the lowest barrier heights.

  11. 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.

  12. 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.

  13. A spherical torus nuclear fusion reactor space propulsion vehicle concept for fast interplanetary travel

    NASA Astrophysics Data System (ADS)

    Williams, Craig H.; Borowski, Stanley K.; Dudzinski, Leonard A.; Juhasz, Albert J.

    1999-01-01

    A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Initial requirements were for a human mission to Saturn with a>5% payload mass fraction and a one way trip time of less than one year. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 235 days, with an initial mass in low Earth orbit of 2,941 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including payload, central truss, nuclear reactor (including diverter and fuel injector), power conversion (including turbine, compressor, alternator, radiator, recuperator, and conditioning), magnetic nozzle, neutral beam injector, tankage, start/re-start reactor and battery, refrigeration, communications, reaction control, and in-space operations. Detailed assessment was done on reactor operations, including plasma characteristics, power balance, and component design.

  14. A Spherical Torus Nuclear Fusion Reactor Space Propulsion Vehicle Concept for Fast Interplanetary Travel

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.; Borowski, Stanley K.; Dudzinski, Leonard A.; Juhasz, Albert J.

    1998-01-01

    A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Initial requirements were for a human mission to Saturn with a greater than 5% payload mass fraction and a one way trip time of less than one year. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 235 days, with an initial mass in low Earth orbit of 2,941 mt. Engineering conceptual design, analysis, and assessment was performed on all ma or systems including payload, central truss, nuclear reactor (including divertor and fuel injector), power conversion (including turbine, compressor, alternator, radiator, recuperator, and conditioning), magnetic nozzle, neutral beam injector, tankage, start/re-start reactor and battery, refrigeration, communications, reaction control, and in-space operations. Detailed assessment was done on reactor operations, including plasma characteristics, power balance, power utilization, and component design.

  15. Failure of the Woods-Saxon nuclear potential to simultaneously reproduce precise fusion and elastic scattering measurements

    SciTech Connect

    Mukherjee, A.; Hinde, D. J.; Dasgupta, M.; Newton, J. O.; Butt, R. D.; Hagino, K.

    2007-04-15

    A precise fusion excitation function has been measured for the {sup 12}C+{sup 208}Pb reaction at energies around the barrier, allowing the fusion barrier distribution to be extracted. The fusion cross sections at high energies differ significantly from existing fusion data. Coupled reaction channels calculations have been carried out with the code FRESCO. A bare potential previously claimed to uniquely describe a wide range of {sup 12}C+{sup 208}Pb near-barrier reaction channels failed to reproduce the new fusion data. The nuclear potential diffuseness of 0.95 fm which fits the fusion excitation function over a broad energy range fails to reproduce the elastic scattering. A diffuseness of 0.55 fm reproduces the fusion barrier distribution and elastic scattering data, but significantly overpredicts the fusion cross sections at high energies. This may be due to physical processes not included in the calculations. To constrain calculations, it is desirable to have precisely measured fusion cross sections, especially at energies around the barrier.

  16. Nuclear Symbiosis - A Means to Achieve Sustainable Nuclear Growth while Limiting the Spread of Sensititive Nuclear Technology

    SciTech Connect

    David Shropshire

    2009-09-01

    Global growth of nuclear energy in the 21st century is creating new challenges to limit the spread of nuclear technology without hindering adoption in countries now considering nuclear power. Independent nuclear states desire autonomy over energy choices and seek energy independence. However, this independence comes with high costs for development of new indigenous fuel cycle capabilities. Nuclear supplier states and expert groups have proposed fuel supply assurance mechanisms such as fuel take-back services, international enrichment services and fuel banks in exchange for recipient state concessions on the development of sensitive technologies. Nuclear states are slow to accept any concessions to their rights under the Non-Proliferation Treaty. To date, decisions not to develop indigenous fuel cycle capabilities have been driven primarily by economics. However, additional incentives may be required to offset a nuclear state’s perceived loss of energy independence. This paper proposes alternative economic development incentives that could help countries decide to forgo development of sensitive nuclear technologies. The incentives are created through a nuclear-centered industrial complex with “symbiotic” links to indigenous economic opportunities. This paper also describes a practical tool called the “Nuclear Materials Exchange” for identifying these opportunities.

  17. Cold nuclear fusion and muon-catalyzed fusion. January 1976-April 1989 (Citations from the INSPEC: Information Services for the Physics and Engineering Communities data base). Report for January 1976-April 1989

    SciTech Connect

    Not Available

    1989-04-01

    This bibliography contains citations concerning experiments and research in a type of nuclear fusion process which occurs at lower temperatures and pressures than conventional fusion reactions. The references describe theoretical and experimental results for a proposed muon-catalyzed fusion reactor, and for studies on muon sticking and reactivation, temperature dependence of fusion rates, and resolution of some engineering challenges. (Contains 82 citations fully indexed and including a title list.)

  18. Protein Sub-Nuclear Localization Based on Effective Fusion Representations and Dimension Reduction Algorithm LDA.

    PubMed

    Wang, Shunfang; Liu, Shuhui

    2015-12-19

    An effective representation of a protein sequence plays a crucial role in protein sub-nuclear localization. The existing representations, such as dipeptide composition (DipC), pseudo-amino acid composition (PseAAC) and position specific scoring matrix (PSSM), are insufficient to represent protein sequence due to their single perspectives. Thus, this paper proposes two fusion feature representations of DipPSSM and PseAAPSSM to integrate PSSM with DipC and PseAAC, respectively. When constructing each fusion representation, we introduce the balance factors to value the importance of its components. The optimal values of the balance factors are sought by genetic algorithm. Due to the high dimensionality of the proposed representations, linear discriminant analysis (LDA) is used to find its important low dimensional structure, which is essential for classification and location prediction. The numerical experiments on two public datasets with KNN classifier and cross-validation tests showed that in terms of the common indexes of sensitivity, specificity, accuracy and MCC, the proposed fusing representations outperform the traditional representations in protein sub-nuclear localization, and the representation treated by LDA outperforms the untreated one.

  19. Evidence of parasexual activity in "asexual amoebae" Cochliopodium spp. (Amoebozoa): extensive cellular and nuclear fusion.

    PubMed

    Tekle, Yonas I; Anderson, O Roger; Lecky, Ariel F

    2014-09-01

    The majority of microbial eukaryotes have long been considered asexual, though new evidence indicates sex, or sexual-like (parasexual) behaviors that deviate from the usual union of two gametes, among other variant aspects. Over a dozen amoebozoans are implicated to have sexual stages. However, the exact mechanism by which sex occurs in these lineages remains elusive. This is mainly due to the diverse quality and cryptic nature of their life cycle. In this study we present evidence of some previously unreported aspects of the life cycle of an amoeba, Cochliopodium, that undergoes unusual intraspecific interactions using light microscopy and immunocytochemistry. Similar to other amoebozoans, Cochliopodium, is considered asexual with no published reports of sex or parasexuality. We also investigated environmental conditions that govern the observed intraspecific interactions. Both light microscopic and immunocytochemistry evidence demonstrates Cochliopodium undergoes cellular fusion (plasmogamy) and nuclear fusion (karyogamy). Large plasmodia eventually undergo karyogamy and contain large fused, polyploid, nuclei. These are observed to fragment, subsequently, by karyotomy (nuclear fission) and cytoplasmic fission to yield uninucleated amoebae. This process could lead to a non-meiotic, parasexual exchange of chromosomes in Cochliopodium. These findings strongly suggest that Cochliopodium is involved in parasexual activity and should no longer be considered strictly asexual.

  20. Different sets of ER-resident J-proteins regulate distinct polar nuclear-membrane fusion events in Arabidopsis thaliana.

    PubMed

    Maruyama, Daisuke; Yamamoto, Masaya; Endo, Toshiya; Nishikawa, Shuh-ichi

    2014-11-01

    Angiosperm female gametophytes contain a central cell with two polar nuclei. In many species, including Arabidopsis thaliana, the polar nuclei fuse during female gametogenesis. We previously showed that BiP, an Hsp70 in the endoplasmic reticulum (ER), was essential for membrane fusion during female gametogenesis. Hsp70 function requires partner proteins for full activity. J-domain containing proteins (J-proteins) are the major Hsp70 functional partners. A. thaliana ER contains three soluble J-proteins, AtERdj3A, AtERdj3B, and AtP58(IPK). Here, we analyzed mutants of these proteins and determined that double-mutant ovules lacking AtP58(IPK) and AtERdj3A or AtERdj3B were defective in polar nuclear fusion. Electron microscopy analysis identified that polar nuclei were in close contact, but no membrane fusion occurred in mutant ovules lacking AtP58(IPK) and AtERdj3A. The polar nuclear outer membrane appeared to be connected via the ER remaining at the inner unfused membrane in mutant ovules lacking AtP58(IPK) and AtERdj3B. These results indicate that ER-resident J-proteins, AtP58(IPK)/AtERdj3A and AtP58(IPK)/AtERdj3B, function at distinct steps of polar nuclear-membrane fusion. Similar to the bip1 bip2 double mutant female gametophytes, the aterdj3a atp58(ipk) double mutant female gametophytes defective in fusion of the outer polar nuclear membrane displayed aberrant endosperm proliferation after fertilization with wild-type pollen. However, endosperm proliferated normally after fertilization of the aterdj3b atp58(ipk) double mutant female gametophytes defective in fusion of the inner membrane. Our results indicate that the polar nuclear fusion defect itself does not cause an endosperm proliferation defect.

  1. Nuclear fusion of deuterons with light nuclei driven by Coulomb explosion of nanodroplets

    SciTech Connect

    Ron, Shlomo; Last, Isidore; Jortner, Joshua

    2012-11-15

    Theoretical-computational studies of table-top laser-driven nuclear fusion of high energy (up to 15 MeV) deuterons with {sup 7}Li, {sup 6}Li, T, and D demonstrate the attainment of high fusion yields. The reaction design constitutes a source of Coulomb exploding deuterium nanodroplets driven by an ultraintense, near-infrared, femtosecond Gaussian laser pulse (peak intensity 2 Multiplication-Sign 10{sup 18}-5 Multiplication-Sign 10{sup 19} W cm{sup -2}) and a solid, hollow cylindrical target containing the second reagent. The exploding nanodroplets source is characterized by the deuteron kinetic energies, their number, and the laser energy absorbed by a nanodroplet. These were computed by scaled electron and ion dynamics simulations, which account for intra-nanodroplet laser intensity attenuation and relativistic effects. The fusion yields Y are determined by the number of the source deuterons and by the reaction probability. When laser intensity attenuation is weak within a single nanodroplet and throughout the nanodroplets assembly, Y exhibits a power law increase with increasing the nanodroplet size. Y is maximized for the nanodroplet size and laser intensity corresponding to the 'transition' between the weak and the strong intensity attenuation domains. The dependence of Y on the laser pulse energy W scales as W{sup 2} for weak assembly intensity attenuation, and as W for strong assembly intensity attenuation. This reaction design attains the highest table-top fusion efficiencies (up to 4 Multiplication-Sign 10{sup 9} J{sup -1} per laser pulse) obtained up to date.

  2. Constraining the equation of state of nuclear matter from fusion hindrance in reactions leading to the production of superheavy elements

    NASA Astrophysics Data System (ADS)

    Veselsky, M.; Klimo, J.; Ma, Yu-Gang; Souliotis, G. A.

    2016-12-01

    The mechanism of fusion hindrance, an effect preventing the synthesis of superheavy elements in the reactions of cold and hot fusion, is investigated using the Boltzmann-Uehling-Uhlenbeck equation, where Coulomb interaction is introduced. A strong sensitivity is observed both to the modulus of incompressibility of symmetric nuclear matter, controlling the competition of surface tension and Coulomb repulsion, and to the stiffness of the density-dependence of symmetry energy, influencing the formation of the neck prior to scission. The experimental fusion probabilities were for the first time used to derive constraints on the nuclear equation of state. A strict constraint on the modulus of incompressibility of nuclear matter K0=240 -260 MeV is obtained while the stiff density-dependences of the symmetry energy (γ >1 ) are rejected.

  3. Neutron Transport and Nuclear Burnup Analysis for the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine

    SciTech Connect

    Kramer, K J; Latkowski, J F; Abbott, R P; Boyd, J K; Powers, J J; Seifried, J E

    2008-10-24

    Lawrence Livermore National Laboratory is currently developing a hybrid fusion-fission nuclear energy system, called LIFE, to generate power and burn nuclear waste. We utilize inertial confinement fusion to drive a subcritical fission blanket surrounding the fusion chamber. It is composed of TRISO-based fuel cooled by the molten salt flibe. Low-yield (37.5 MJ) targets and a repetition rate of 13.3 Hz produce a 500 MW fusion source that is coupled to the subcritical blanket, which provides an additional gain of 4-8, depending on the fuel. In the present work, we describe the neutron transport and nuclear burnup analysis. We utilize standard analysis tools including, the Monte Carlo N-Particle (MCNP) transport code, ORIGEN2 and Monteburns to perform the nuclear design. These analyses focus primarily on a fuel composed of depleted uranium not requiring chemical reprocessing or enrichment. However, other fuels such as weapons grade plutonium and highly-enriched uranium are also under consideration. In addition, we have developed a methodology using {sup 6}Li as a burnable poison to replace the tritium burned in the fusion targets and to maintain constant power over the lifetime of the engine. The results from depleted uranium analyses suggest up to 99% burnup of actinides is attainable while maintaining full power at 2GW for more than five decades.

  4. 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.

  5. Solid-State Nuclear Magnetic Resonance Investigation of the Structural Topology and Lipid Interactions of a Viral Fusion Protein Chimera Containing the Fusion Peptide and Transmembrane Domain.

    PubMed

    Yao, Hongwei; Lee, Myungwoon; Liao, Shu-Yu; Hong, Mei

    2016-12-13

    The fusion peptide (FP) and transmembrane domain (TMD) of viral fusion proteins play important roles during virus-cell membrane fusion, by inducing membrane curvature and transient dehydration. The structure of the water-soluble ectodomain of viral fusion proteins has been extensively studied crystallographically, but the structures of the FP and TMD bound to phospholipid membranes are not well understood. We recently investigated the conformations and lipid interactions of the separate FP and TMD peptides of parainfluenza virus 5 (PIV5) fusion protein F using solid-state nuclear magnetic resonance. These studies provide structural information about the two domains when they are spatially well separated in the fusion process. To investigate how these two domains are structured relative to each other in the postfusion state, when the ectodomain forms a six-helix bundle that is thought to force the FP and TMD together in the membrane, we have now expressed and purified a chimera of the FP and TMD, connected by a Gly-Lys linker, and measured the chemical shifts and interdomain contacts of the protein in several lipid membranes. The FP-TMD chimera exhibits α-helical chemical shifts in all the membranes examined and does not cause strong curvature of lamellar membranes or membranes with negative spontaneous curvature. These properties differ qualitatively from those of the separate peptides, indicating that the FP and TMD interact with each other in the lipid membrane. However, no (13)C-(13)C cross peaks are observed in two-dimensional correlation spectra, suggesting that the two helices are not tightly associated. These results suggest that the ectodomain six-helix bundle does not propagate into the membrane to the two hydrophobic termini. However, the loosely associated FP and TMD helices are found to generate significant negative Gaussian curvature to membranes that possess spontaneous positive curvature, consistent with the notion that the FP-TMD assembly may

  6. Fusion Power measurement at ITER

    SciTech Connect

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M.

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  7. Multiscale integral analysis of a HT leakage in a fusion nuclear power plant

    NASA Astrophysics Data System (ADS)

    Velarde, M.; Fradera, J.; Perlado, J. M.; Zamora, I.; Martínez-Saban, E.; Colomer, C.; Briani, P.

    2016-05-01

    The present work presents an example of the application of an integral methodology based on a multiscale analysis that covers the whole tritium cycle within a nuclear fusion power plant, from a micro scale, analyzing key components where tritium is leaked through permeation, to a macro scale, considering its atmospheric transport. A leakage from the Nuclear Power Plants, (NPP) primary to the secondary side of a heat exchanger (HEX) is considered for the present example. Both primary and secondary loop coolants are assumed to be He. Leakage is placed inside the HEX, leaking tritium in elementary tritium (HT) form to the secondary loop where it permeates through the piping structural material to the exterior. The Heating Ventilation and Air Conditioning (HVAC) system removes the leaked tritium towards the NPP exhaust. The HEX is modelled with system codes and coupled to Computational Fluid Dynamic (CFD) to account for tritium dispersion inside the nuclear power plants buildings and in site environment. Finally, tritium dispersion is calculated with an atmospheric transport code and a dosimetry analysis is carried out. Results show how the implemented methodology is capable of assessing the impact of tritium from the microscale to the atmospheric scale including the dosimetric aspect.

  8. Evaluation of CFETR as a Fusion Nuclear Science Facility using multiple system codes

    NASA Astrophysics Data System (ADS)

    Chan, V. S.; Costley, A. E.; Wan, B. N.; Garofalo, A. M.; Leuer, J. A.

    2015-02-01

    This paper presents the results of a multi-system codes benchmarking study of the recently published China Fusion Engineering Test Reactor (CFETR) pre-conceptual design (Wan et al 2014 IEEE Trans. Plasma Sci. 42 495). Two system codes, General Atomics System Code (GASC) and Tokamak Energy System Code (TESC), using different methodologies to arrive at CFETR performance parameters under the same CFETR constraints show that the correlation between the physics performance and the fusion performance is consistent, and the computed parameters are in good agreement. Optimization of the first wall surface for tritium breeding and the minimization of the machine size are highly compatible. Variations of the plasma currents and profiles lead to changes in the required normalized physics performance, however, they do not significantly affect the optimized size of the machine. GASC and TESC have also been used to explore a lower aspect ratio, larger volume plasma taking advantage of the engineering flexibility in the CFETR design. Assuming the ITER steady-state scenario physics, the larger plasma together with a moderately higher BT and Ip can result in a high gain Qfus ˜ 12, Pfus ˜ 1 GW machine approaching DEMO-like performance. It is concluded that the CFETR baseline mode can meet the minimum goal of the Fusion Nuclear Science Facility (FNSF) mission and advanced physics will enable it to address comprehensively the outstanding critical technology gaps on the path to a demonstration reactor (DEMO). Before proceeding with CFETR construction steady-state operation has to be demonstrated, further development is needed to solve the divertor heat load issue, and blankets have to be designed with tritium breeding ratio (TBR) >1 as a target.

  9. First experimental results at the gran sasso laboratory on cold nuclear fusion in titanium electrodes

    NASA Astrophysics Data System (ADS)

    Bertin, A.; Bruschi, M.; Capponi, M.; De Castro, S.; Marconi, U.; Moroni, C.; Piccinini, M.; Semprini-Cesari, N.; Trombini, A.; Vitale, A.; Zoccoli, A.; Czirr, J. B.; Jensen, G. L.; Jones, S. E.; Palmer, E. P.

    1990-06-01

    We present here the first results obtained at the Gran Sasso Laboratory on the neutron emission following the electrolytic infusion of deuterons into titanium electrodes. The measurements were carried out under a 4000-m water equivalent rock thickness, i.e., in an extremely reduced cosmic-radiation background. The neutrons were detected by proton-recoil liquid scintillation detectors, allowing a huge reduction of the local gamma-ray background. The results obtained provide a neutron emission rate comparable in size to the one recently reported by Jones et al. in an electrolysis experiment performed with a different apparatus in ordinary laboratory conditions. They provide more evidence in favor of low-level cold nuclear fusions in metals.

  10. ARC: A compact, high-field, disassemblable fusion nuclear science facility and demonstration power plant

    NASA Astrophysics Data System (ADS)

    Sorbom, Brandon; Ball, Justin; Palmer, Timothy; Mangiarotti, Franco; Sierchio, Jennifer; Bonoli, Paul; Kasten, Cale; Sutherland, Derek; Barnard, Harold; Haakonsen, Christian; Goh, Jon; Sung, Choongki; Whyte, Dennis

    2014-10-01

    The Affordable, Robust, Compact (ARC) reactor conceptual design aims to reduce the size, cost, and complexity of a combined Fusion Nuclear Science Facility (FNSF) and demonstration fusion pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has Rare Earth Barium Copper Oxide (REBCO) superconducting toroidal field coils with joints to allow disassembly, allowing for removal and replacement of the vacuum vessel as a single component. Inboard-launched current drive of 25 MW LHRF power and 13.6 MW ICRF power is used to provide a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing Fluorine Lithium Beryllium (FLiBe) molten salt. The liquid blanket acts as a working fluid, coolant, and tritium breeder, and minimizes the solid material that can become activated. The large temperature range over which FLiBe is liquid permits blanket operation at 800-900 K with single phase fluid cooling and allows use of a high-efficiency Brayton cycle for electricity production in the secondary coolant loop.

  11. Mutagenesis and nuclear magnetic resonance analyses of the fusion peptide of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus F protein.

    PubMed

    Tan, Ying; Jiang, Ling; Wang, Manli; Yin, Feifei; Deng, Fei; Liu, Maili; Hu, Zhihong; Wang, Hualin

    2008-08-01

    The entry of enveloped viruses into cells is normally mediated by fusion between viral and cellular membranes, in which the fusion peptide plays a crucial role. The fusion peptides of group II nucleopolyhedrovirus (NPV) F proteins are quite conserved, with a hydrophobic region located at the N terminal of the F(1) fragment. For this report, we used mutagenesis and nuclear magnetic resonance (NMR) to study the structure and function of the fusion peptide of the Helicoverpa armigera single-nucleocapsid NPV (HearNPV) F protein (HaF). Five mutations in the fusion peptide of HaF, N(1)G, N(1)L, I(2)N, G(3)L, and D(11)L, were generated separately, and the mutated f genes were transformed into the f-null HearNPV bacmid. The mutations N(1)L, I(2)N, and D(11)L were found to completely abolish the ability of the recombinant bacmids to produce infectious budded virus, while the mutations N(1)G and G(3)L did not. The low-pH-induced envelope fusion assay demonstrated that the N(1)G substitution increased the fusogenicity of HaF, while the G(3)L substitution reduced its fusogenicity. NMR spectroscopy was used to determine the structure of a synthetic fusion peptide of HaF in the presence of sodium dodecyl sulfate micelles at pH 5.0. The fusion peptide appeared to be an amphiphilic structure composed of a flexible coil in the N terminus from N(1) to N(5), a 3(10)-helix from F(6) to G(8), a turn at S(9), and a regular alpha-helix from V(10) to D(19). The data provide the first NMR structure of a baculovirus fusion peptide and allow us to further understand the relationship of structure and function of the fusion peptide.

  12. From Entrepreneurial Fission to Entrepreneurial Fusion: Achieving Interaction Resonance in a Micro-Innovation Ecology

    ERIC Educational Resources Information Center

    Curley, Martin G.; Formica, Piero; Nicolo, Vincenzo

    2011-01-01

    Incubators are embedded in the culture of the economics of (value-added) services. To date, at least in Europe, they have operated in a manner analogous to the generation of nuclear power; that is, attempting to produce "entrepreneurial energy" through a process of fission that creates a division between the aspiring entrepreneurs'…

  13. Laser-Driven Ultra-Relativistic Plasmas - Nuclear Fusion in Coulomb Shock Waves, Rouge Waves, and Background Matter

    DTIC Science & Technology

    2015-05-05

    non-relativistic matter , radiation, and dark energy components. - 10 - In application to astrophysics and cosmology, our theory can describe the...AND SUBTITLE LASER-DRIVEN ULTRA-RELATIVISTIC PLASMAS - NUCLEAR FUSION IN COULOMB SHOCK WAVES, ROUGE WAVES, AND BACKGROUND MATTER . 5a.  CONTRACT

  14. 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.

  15. Nuclear replacement of in vitro-matured porcine oocytes by a serial centrifugation and fusion method.

    PubMed

    Maedomari, N; Kikuchi, K; Nagai, T; Fahrudin, M; Kaneko, H; Noguchi, J; Nakai, M; Ozawa, M; Somfai, T; Nguyen, L V; Ito, J; Kashiwazaki, N

    2010-08-01

    The objective of the present study was to establish a method for nuclear replacement in metaphase-II (M-II) stage porcine oocytes. Karyoplasts containing M-II chromosomes (K) and cytoplasts without chromosomes (C) were produced from in vitro-matured oocytes by a serial centrifugation method. The oocytes were then reconstructed by fusion of one karyoplast with 1, 2, 3 or 4 cytoplasts (K + 1C, K + 2C, K + 3C and K + 4C, respectively). Reconstructed oocytes, karyoplasts without fusion of any cytoplast (K) and zona-free M-II oocytes (control) were used for experiments. The rates of female pronucleus formation after parthenogenetic activation in all groups of reconstructed oocytes (58.2-77.4%) were not different from those of the K and control groups (58.2% and 66.0%, respectively). In vitro fertilization was carried out to assay the fertilization ability and subsequent embryonic development of the reconstructed oocytes. The cytoplast : karyoplast ratio did not affect the fertilization status (penetration and male pronuclear formation rates) of the oocytes. A significantly high monospermy rate was found in K oocytes (p < 0.05, 61.6%) compared with the other groups (18.2-32.8%). Blastocyst formation rates increased significantly as the number of the cytoplasts fused with karyoplasts increased (p < 0.05, 0.0-15.3%). The blastocyst rate in the K + 4C group (15.3%) was comparable with that of the control (17.8%). Total cell numbers in both the K + 3C and K + 4C groups (16.0 and 15.3 cells, respectively) were comparable with that of the control (26.2 cells). Our results demonstrate that a serial centrifugation and fusion (Centri-Fusion) is an effective method for producing M-II chromosome transferred oocytes with normal fertilization ability and in vitro development. It is suggested that the number of cytoplasts fused with a karyoplast plays a critical role in embryonic development.

  16. PREFACE: 11th International Spring Seminar on Nuclear Physics: Shell Model and Nuclear Structure - achievements of the past two decades

    NASA Astrophysics Data System (ADS)

    2015-02-01

    The 11th International Seminar on Nuclear Physics was held in Ischia from May 12 to May 16, 2014. This Seminar was dedicated to Aldo Covello, who has been the promoter of this series of meetings, which started in Sorrento in 1986 and continued with meetings held every two or three years in the Naples area. Aldo's idea was to offer to a group of researchers, actively working in selected fields of Nuclear Physics, the opportunity to confront their points of view in a lively and informal way. The choice for the period of the year, Spring, as well as the sites chosen reflected this intent. The first meeting was of a purely theoretical nature, but it was immediately clear that the scope of these conferences needed to be enlarged calling into play the experimental community. Then, starting from the second meeting, all the following ones have been characterized by fruitful discussion between theoretical and experimental researchers on current achievements and future developments of nuclear structure. This may be read, in fact, as one of the motivating factors for Aldo's election as Fellow of the American Physical Society in 2008 "... for his outstanding contributions to the international nuclear physics community by providing, for over two decades, a venue for theorists and experimentalists to share their latest ideas." The present meeting, organized by Aldo's former students and with the benefit of his suggestions, has maintained this tradition. The title "Shell model and nuclear structure: achievements of the past two decades" recalls that of the 2nd International Spring Seminar "Shell Model and Nuclear Structure: where do we stand?". The main aim of this 11th Seminar was, in fact, to discuss the changes of the past two decades on our view of nuclei in terms of shell structure as well as the perspectives of the shell model, which has been one of the key points in Aldo's research. This point is well accounted by the Opening Speech of Igal Talmi, one of the fathers of the

  17. NSF- and SNARE-mediated membrane fusion is required for nuclear envelope formation and completion of nuclear pore complex assembly in Xenopus laevis egg extracts.

    PubMed

    Baur, Tina; Ramadan, Kristijan; Schlundt, Andreas; Kartenbeck, Jürgen; Meyer, Hemmo H

    2007-08-15

    Despite the progress in understanding nuclear envelope (NE) reformation after mitosis, it has remained unclear what drives the required membrane fusion and how exactly this is coordinated with nuclear pore complex (NPC) assembly. Here, we show that, like other intracellular fusion reactions, NE fusion in Xenopus laevis egg extracts is mediated by SNARE proteins that require activation by NSF. Antibodies against Xenopus NSF, depletion of NSF or the dominant-negative NSF(E329Q) variant specifically inhibited NE formation. Staging experiments further revealed that NSF was required until sealing of the envelope was completed. Moreover, excess exogenous alpha-SNAP that blocks SNARE function prevented membrane fusion and caused accumulation of non-flattened vesicles on the chromatin surface. Under these conditions, the nucleoporins Nup107 and gp210 were fully recruited, whereas assembly of FxFG-repeat-containing nucleoporins was blocked. Together, we define NSF- and SNARE-mediated membrane fusion events as essential steps during NE formation downstream of Nup107 recruitment, and upstream of membrane flattening and completion of NPC assembly.

  18. Possible generation of heat from nuclear fusion in Earth’s inner core

    NASA Astrophysics Data System (ADS)

    Fukuhara, Mikio

    2016-11-01

    The cause and source of the heat released from Earth’s interior have not yet been determined. Some research groups have proposed that the heat is supplied by radioactive decay or by a nuclear georeactor. Here we postulate that the generation of heat is the result of three-body nuclear fusion of deuterons confined in hexagonal FeDx core-centre crystals; the reaction rate is enhanced by the combined attraction effects of high-pressure (~364 GPa) and high-temperature (~5700 K) and by the physical catalysis of neutral pions: 2D + 2D + 2D → 21H + 4He + 2  + 20.85 MeV. The possible heat generation rate can be calculated as 8.12 × 1012 J/m3, based on the assumption that Earth’s primitive heat supply has already been exhausted. The H and He atoms produced and the anti-neutrino are incorporated as Fe-H based alloys in the H-rich portion of inner core, are released from Earth’s interior to the universe, and pass through Earth, respectively.

  19. Possible generation of heat from nuclear fusion in Earth’s inner core

    PubMed Central

    Fukuhara, Mikio

    2016-01-01

    The cause and source of the heat released from Earth’s interior have not yet been determined. Some research groups have proposed that the heat is supplied by radioactive decay or by a nuclear georeactor. Here we postulate that the generation of heat is the result of three-body nuclear fusion of deuterons confined in hexagonal FeDx core-centre crystals; the reaction rate is enhanced by the combined attraction effects of high-pressure (~364 GPa) and high-temperature (~5700 K) and by the physical catalysis of neutral pions: 2D + 2D + 2D → 21H + 4He + 2  + 20.85 MeV. The possible heat generation rate can be calculated as 8.12 × 1012 J/m3, based on the assumption that Earth’s primitive heat supply has already been exhausted. The H and He atoms produced and the anti-neutrino are incorporated as Fe-H based alloys in the H-rich portion of inner core, are released from Earth’s interior to the universe, and pass through Earth, respectively. PMID:27876860

  20. Possible generation of heat from nuclear fusion in Earth's inner core.

    PubMed

    Fukuhara, Mikio

    2016-11-23

    The cause and source of the heat released from Earth's interior have not yet been determined. Some research groups have proposed that the heat is supplied by radioactive decay or by a nuclear georeactor. Here we postulate that the generation of heat is the result of three-body nuclear fusion of deuterons confined in hexagonal FeDx core-centre crystals; the reaction rate is enhanced by the combined attraction effects of high-pressure (~364 GPa) and high-temperature (~5700 K) and by the physical catalysis of neutral pions: (2)D + (2)D + (2)D → 2(1)H + (4)He + 2  + 20.85 MeV. The possible heat generation rate can be calculated as 8.12 × 10(12) J/m(3), based on the assumption that Earth's primitive heat supply has already been exhausted. The H and He atoms produced and the anti-neutrino are incorporated as Fe-H based alloys in the H-rich portion of inner core, are released from Earth's interior to the universe, and pass through Earth, respectively.

  1. Nuclear energy acceptance and potential role to meet future energy demand. Which technical/scientific achievements are needed?

    SciTech Connect

    Schenkel, Roland

    2012-06-19

    25 years after Chernobyl, the Fukushima disaster has changed the perspectives of nuclear power. The disaster has shed a negative light on the independence, reliability and rigor of the national nuclear regulator and plant operator and the usefulness of the international IAEA guidelines on nuclear safety. It has become clear that, in the light of the most severe earthquake in the history of Japan, the plants at Fukushima Daiichi were not adequately protected against tsunamis. Nuclear acceptance has suffered enormously and has changed the perspectives of nuclear energy dramatically in countries that have a very risk-sensitive population, Germany is an example. The paper analyses the reactions in major countries and the expected impact on future deployment of reactors and on R and D activities. On the positive side, the disaster has demonstrated a remarkable robustness of most of the 14 reactors closest to the epicentre of the Tohoku Seaquake although not designed to an event of level 9.0. Public acceptance can only be regained with a rigorous and worldwide approach towards inherent reactor safety and design objectives that limit the impact of severe accidents to the plant itself (like many of the new Gen III reactors). A widespread release of radioactivity and the evacuation (temporary or permanent) of the population up to 30 km around a facility are simply not acceptable. Several countries have announced to request more stringent international standards for reactor safety. The IAEA should take this move forward and intensify and strengthen the different peer review mission schemes. The safety guidelines and peer reviews should in fact become legally binding for IAEA members. The paper gives examples of the new safety features developed over the last 20 years and which yield much safer reactors with lesser burden to the environment under severe accident conditions. The compatibility of these safety systems with the current concepts for fusion-fission hybrids, which

  2. Nuclear energy acceptance and potential role to meet future energy demand. Which technical/scientific achievements are needed?

    NASA Astrophysics Data System (ADS)

    Schenkel, Roland

    2012-06-01

    25 years after Chernobyl, the Fukushima disaster has changed the perspectives of nuclear power. The disaster has shed a negative light on the independence, reliability and rigor of the national nuclear regulator and plant operator and the usefulness of the international IAEA guidelines on nuclear safety. It has become clear that, in the light of the most severe earthquake in the history of Japan, the plants at Fukushima Daiichi were not adequately protected against tsunamis. Nuclear acceptance has suffered enormously and has changed the perspectives of nuclear energy dramatically in countries that have a very risk-sensitive population, Germany is an example. The paper analyses the reactions in major countries and the expected impact on future deployment of reactors and on R&D activities. On the positive side, the disaster has demonstrated a remarkable robustness of most of the 14 reactors closest to the epicentre of the Tohoku Seaquake although not designed to an event of level 9.0. Public acceptance can only be regained with a rigorous and worldwide approach towards inherent reactor safety and design objectives that limit the impact of severe accidents to the plant itself (like many of the new Gen III reactors). A widespread release of radioactivity and the evacuation (temporary or permanent) of the population up to 30 km around a facility are simply not acceptable. Several countries have announced to request more stringent international standards for reactor safety. The IAEA should take this move forward and intensify and strengthen the different peer review mission schemes. The safety guidelines and peer reviews should in fact become legally binding for IAEA members. The paper gives examples of the new safety features developed over the last 20 years and which yield much safer reactors with lesser burden to the environment under severe accident conditions. The compatibility of these safety systems with the current concepts for fusion-fission hybrids, which have

  3. Nuclear Fusion Within Extremely Dense Plasma Enhanced by Quantum Particle Waves

    NASA Astrophysics Data System (ADS)

    Miao, Feng; Zheng, Xianjun; Deng, Baiquan

    2015-05-01

    Quantum effects play an enhancement role in p-p chain reactions occurring within stars. Such an enhancement is quantified by a wave penetration factor that is proportional to the density of the participating fuel particles. This leads to an innovative theory for dense plasma, and its result shows good agreement with independent data derived from the solar energy output. An analysis of the first Z-pinch machine in mankind's history exhibiting neutron emission leads to a derived deuterium plasma beam density greater than that of water, with plasma velocities exceeding 10000 km/s. Fusion power could be achieved by the intersection of four such pinched plasma beams with powerful head-on collisions in their common focal region due to the beam and target enhanced reaction. supported by the Fund for the Construction of Graduate Degree of China (No. 2014XWD-S0805)

  4. Effective donor cell fusion conditions for production of cloned dogs by somatic cell nuclear transfer.

    PubMed

    Park, JungEun; Oh, HyunJu; Hong, SoGun; Kim, MinJung; Kim, GeonA; Koo, OkJae; Kang, SungKeun; Jang, Goo; Lee, ByeongChun

    2011-03-01

    As shown by the birth of the first cloned dog 'Snuppy', a protocol to produce viable cloned dogs has been reported. In order to evaluate optimum fusion conditions for improving dog cloning efficiency, in vivo matured oocytes were reconstructed with adult somatic cells from a female Pekingese using different fusion conditions. Fusion with needle vs chamber methods, and with low vs high pulse strength was compared by evaluating fusion rate and in vivo development of canine cloned embryos. The fusion rates in the high voltage groups were significantly higher than in the low voltage groups regardless of fusion method (83.5 vs 66.1% for the needle fusion method, 67.4 vs 37.9% for the fusion chamber method). After embryo transfer, one each pregnancy was detected after using the needle fusion method with high and low voltage and in the chamber fusion method with high voltage, whereas no pregnancy was detected using the chamber method with low voltage. However, only the pregnancy from the needle fusion method with high voltage was maintained to term and one healthy puppy was delivered. The results of the present study demonstrated that two DC pulses of 3.8 to 4.0 kV/cm for 15 μsec using the needle fusion method were the most effective method for the production of cloned dogs under the conditions of this experiment.

  5. Particle beam fusion

    SciTech Connect

    1980-12-31

    Today, in keeping with Sandia Laboratories` designation by the Department of Energy as the lead laboratory for the pulsed power approach to fusion, its efforts include major research activities and the construction of new facilities at its Albuquerque site. Additionally, in its capacity as lead laboratory, Sandia coordinates DOE-supported pulsed power fusion work at other government operated laboratories, with industrial contractors, and universities. The beginning of Sandia`s involvement in developing fusion power was an outgrowth of its contributions to the nation`s nuclear weapon program. The Laboratories` work in the early 1960`s emphasized the use of pulsed radiation environments to test the resistance of US nuclear weapons to enemy nuclear bursts. A careful study of options for fusion power indicated that Sandia`s expertise in the pulsed power field could provide a powerful match to ignite fusion fuel. Although creating test environments is an achieved goal of Sandia`s overall program, this work and other military tasks protected by appropriate security regulations will continue, making full use of the same pulsed power technology and accelerators as the fusion-for-energy program. Major goals of Sandia`s fusion program including the following: (1) complete a particle accelerator to deliver sufficient beam energy for igniting fusion targets; (2) obtain net energy gain, this goal would provide fusion energy output in excess of energy stored in the accelerator; (3) develop a technology base for the repetitive ignition of pellets in a power reactor. After accomplishing these goals, the technology will be introduced to the nation`s commercial sector.

  6. Ion acceleration and D-D nuclear fusion in laser-generated plasma from advanced deuterated polyethylene.

    PubMed

    Torrisi, Lorenzo

    2014-10-23

    Deuterated polyethylene targets have been irradiated by means of a 1016 W/cm2 laser using 600 J pulse energy, 1315 nm wavelength, 300 ps pulse duration and 70 micron spot diameter. The plasma parameters were measured using on-line diagnostics based on ion collectors, SiC detectors and plastic scintillators, all employed in time-of-flight configuration. In addition, a Thomson parabola spectrometer, an X-ray streak camera, and calibrated neutron dosimeter bubble detectors were employed. Characteristic protons and neutrons at maximum energies of 3.0 MeV and 2.45 MeV, respectively, were detected, confirming that energy spectra of reaction products coming from deuterium-deuterium nuclear fusion occur. In thick advanced targets a fusion rate of the order of 2 × 108 fusions per laser shot was calculated.

  7. Additive manufacturing of 316L stainless steel by electron beam melting for nuclear fusion applications

    NASA Astrophysics Data System (ADS)

    Zhong, Yuan; Rännar, Lars-Erik; Liu, Leifeng; Koptyug, Andrey; Wikman, Stefan; Olsen, Jon; Cui, Daqing; Shen, Zhijian

    2017-04-01

    A feasibility study was performed to fabricate ITER In-Vessel components by one of the metal additive manufacturing methods, Electron Beam Melting® (EBM®). Solid specimens of SS316L with 99.8% relative density were prepared from gas atomized precursor powder granules. After the EBM® process the phase remains as austenite and the composition has practically not been changed. The RCC-MR code used for nuclear pressure vessels provides guidelines for this study and tensile tests and Charpy-V tests were carried out at 22 °C (RT) and 250 °C (ET). This work provides the first set of mechanical and microstructure data of EBM® SS316L for nuclear fusion applications. The mechanical testing shows that the yield strength, ductility and toughness are well above the acceptance criteria and only the ultimate tensile strength of EBM® SS316L is below the RCC-MR code. Microstructure characterizations reveal the presence of hierarchical structures consisting of solidified melt pools, columnar grains and irregular shaped sub-grains. Lots of precipitates enriched in Cr and Mo are observed at columnar grain boundaries while no sign of element segregation is shown at the sub-grain boundaries. Such a unique microstructure forms during a non-equilibrium process, comprising rapid solidification and a gradient 'annealing' process due to anisotropic thermal flow of accumulated heat inside the powder granule matrix. Relations between process parameters, specimen geometry (total building time) and sub-grain structure are discussed. Defects are formed mainly due to the large layer thickness (100 μm) which generates insufficient bonding between a few of the adjacently formed melt pools during the process. Further studies should focus on adjusting layer thickness to improve the strength of EBM® SS316L and optimizing total building time.

  8. 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.

  9. Vesicular PtdIns(3,4,5)P3 and Rab7 are key effectors of sea urchin zygote nuclear membrane fusion.

    PubMed

    Lete, Marta G; Byrne, Richard D; Alonso, Alicia; Poccia, Dominic; Larijani, Banafshé

    2017-01-15

    Regulation of nuclear envelope dynamics is an important example of the universal phenomena of membrane fusion. The signalling molecules involved in nuclear membrane fusion might also be conserved during the formation of both pronuclear and zygote nuclear envelopes in the fertilised egg. Here, we determine that class-I phosphoinositide 3-kinases (PI3Ks) are needed for in vitro nuclear envelope formation. We show that, in vivo, PtdIns(3,4,5)P3 is transiently located in vesicles around the male pronucleus at the time of nuclear envelope formation, and around male and female pronuclei before membrane fusion. We illustrate that class-I PI3K activity is also necessary for fusion of the female and male pronuclear membranes. We demonstrate, using coincidence amplified Förster resonance energy transfer (FRET) monitored using fluorescence lifetime imaging microscopy (FLIM), a protein-lipid interaction of Rab7 GTPase and PtdIns(3,4,5)P3 that occurs during pronuclear membrane fusion to create the zygote nuclear envelope. We present a working model, which includes several molecular steps in the pathways controlling fusion of nuclear envelope membranes.

  10. Antiproton catalyzed fusion

    SciTech Connect

    Morgan, D.L. Jr.; Perkins, L.J.; Haney, S.W.

    1995-05-15

    Because of the potential application to power production, it is important to investigate a wide range of possible means to achieve nuclear fusion, even those that may appear initially to be infeasible. In antiproton catalyzed fusion, the negative antiproton shields the repulsion between the positively charged nuclei of hydrogen isotopes, thus allowing a much higher level of penetration through the repulsive Coulomb barrier, and thereby greatly enhancing the fusion cross section. Because of their more compact wave function, the more massive antiprotons offer considerably more shielding than do negative muons. The effects of the shielding on fusion cross sections are most predominate, at low energies. If the antiproton could exist in the ground state with a nucleus for a sufficient time without annihilating, the fusion cross sections are so enhanced that at room temperature energies, values up to about 1,000 barns (that for d+t) would be possible. Unfortunately, the cross section for antiproton annihilation with the incoming nucleus is even higher. A model that provides an upper bound for the fusion to annihilation cross section for all relevant energies indicates that each antiproton will catalyze no more than about one fusion. Because the energy required to make one antiproton greatly exceeds the fusion energy that is released, this level of catalysis is far from adequate for power production.

  11. Fusion between perinuclear virions and the outer nuclear membrane requires the fusogenic activity of herpes simplex virus gB.

    PubMed

    Wright, Catherine C; Wisner, Todd W; Hannah, Brian P; Eisenberg, Roselyn J; Cohen, Gary H; Johnson, David C

    2009-11-01

    Herpesviruses cross nuclear membranes (NMs) in two steps, as follows: (i) capsids assemble and bud through the inner NM into the perinuclear space, producing enveloped virus particles, and (ii) the envelopes of these virus particles fuse with the outer NM. Two herpes simplex virus (HSV) glycoproteins, gB and gH (the latter, likely complexed as a heterodimer with gL), are necessary for the second step of this process. Mutants lacking both gB and gH accumulate in the perinuclear space or in herniations (membrane vesicles derived from the inner NM). Both gB and gH/gL are also known to act directly in fusing the virion envelope with host cell membranes during HSV entry into cells, i.e., both glycoproteins appear to function directly in different aspects of the membrane fusion process. We hypothesized that HSV gB and gH/gL also act directly in the membrane fusion that occurs during virus egress from the nucleus. Previous studies of the role of gB and gH/gL in nuclear egress involved HSV gB and gH null mutants that could potentially also possess gross defects in the virion envelope. Here, we produced recombinant HSV-expressing mutant forms of gB with single amino acid substitutions in the hydrophobic "fusion loops." These fusion loops are thought to play a direct role in membrane fusion by insertion into cellular membranes. HSV recombinants expressing gB with any one of four fusion loop mutations (W174R, W174Y, Y179K, and A261D) were unable to enter cells. Moreover, two of the mutants, W174Y and Y179K, displayed reduced abilities to mediate HSV cell-to-cell spread, and W174R and A261D exhibited no spread. All mutant viruses exhibited defects in nuclear egress, enveloped virions accumulated in herniations and in the perinuclear space, and fewer enveloped virions were detected on cell surfaces. These results support the hypothesis that gB functions directly to mediate the fusion between perinuclear virus particles and the outer NM.

  12. Numerical Solution of the Electron Heat Transport Equation and Physics-Constrained Modeling of the Thermal Conductivity via Sequential Quadratic Programming Optimization in Nuclear Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Paloma, Cynthia S.

    The plasma electron temperature (Te) plays a critical role in a tokamak nu- clear fusion reactor since temperatures on the order of 108K are required to achieve fusion conditions. Many plasma properties in a tokamak nuclear fusion reactor are modeled by partial differential equations (PDE's) because they depend not only on time but also on space. In particular, the dynamics of the electron temperature is governed by a PDE referred to as the Electron Heat Transport Equation (EHTE). In this work, a numerical method is developed to solve the EHTE based on a custom finite-difference technique. The solution of the EHTE is compared to temperature profiles obtained by using TRANSP, a sophisticated plasma transport code, for specific discharges from the DIII-D tokamak, located at the DIII-D National Fusion Facility in San Diego, CA. The thermal conductivity (also called thermal diffusivity) of the electrons (Xe) is a plasma parameter that plays a critical role in the EHTE since it indicates how the electron temperature diffusion varies across the minor effective radius of the tokamak. TRANSP approximates Xe through a curve-fitting technique to match experimentally measured electron temperature profiles. While complex physics-based model have been proposed for Xe, there is a lack of a simple mathematical model for the thermal diffusivity that could be used for control design. In this work, a model for Xe is proposed based on a scaling law involving key plasma variables such as the electron temperature (Te), the electron density (ne), and the safety factor (q). An optimization algorithm is developed based on the Sequential Quadratic Programming (SQP) technique to optimize the scaling factors appearing in the proposed model so that the predicted electron temperature and magnetic flux profiles match predefined target profiles in the best possible way. A simulation study summarizing the outcomes of the optimization procedure is presented to illustrate the potential of the

  13. Post-fusion treatment with MG132 increases transcription factor expression in somatic cell nuclear transfer embryos in pigs.

    PubMed

    You, Jinyoung; Lee, Joohyeong; Kim, Jinyoung; Park, Junhong; Lee, Eunsong

    2010-02-01

    The objective of this study was to examine the effect of post-fusion treatment of somatic cell nuclear transfer (SCNT) oocytes with the proteasomal inhibitor MG132 on maturation promoting factor (MPF) activity, nuclear remodeling, embryonic development, and gene expression of cloned pig embryos. Immediately after electrofusion, SCNT oocytes were treated with MG132 and/or caffeine for 2 hr, vanadate for 0.5 hr, or vanadate for 0.5 hr followed by MG132 for 1.5 hr. Of the MG132 concentrations tested (0-5 microM), the 1 microM concentration showed a higher rate of blastocyst formation (25.9%) than 0 (14.2%), 0.5 (16.9%), and 5 microM (16.9%). Post-fusion treatment with MG132, caffeine, and both MG132 and caffeine improved blastocyst formation (22.1%, 21.4%, and 24.4%, respectively), whereas vanadate treatment inhibited blastocyst formation (6.5%) compared to the control (11.1%). When examined 2 hr after fusion and 1 hr after activation, MPF activity remained at a higher (P < 0.05) level in SCNT oocytes that were treated post-fusion with caffeine and/or MG132, but it was decreased by vanadate. The rate of oocytes showing premature chromosome condensation was not altered by MG132 but was decreased by vanadate treatment. In addition, formation of single pronuclei was increased by MG132 compared to control and vanadate treatment. MG132-treated embryos showed increased expression of POU5F1, DPPA2, DPPA3, DPPA5, and NDP52l1 genes compared to control embryos. Our results demonstrate that post-fusion treatment of SCNT oocytes with MG132 prevents MPF degradation and increases expression of transcription factors in SCNT embryos, which are necessary for normal development of SCNT embryos.

  14. A review of nuclear data needs and their status for fusion reactor technology with some suggestions on a strategy to satisfy the requirements

    SciTech Connect

    Smith, D.L. ); Cheng, E.T. )

    1991-09-01

    A review was performed on the needs and status of nuclear data for fusion-reactor technology. Generally, the status of nuclear data for fusion has been improved during the past two decades due to the dedicated effort of the nuclear data developers. However, there are still deficiencies in the nuclear data base, particularly in the areas of activation and neutron scattering cross sections. Activation cross sections were found to be unsatisfactory in 83 of the 153 reactions reviewed. The scattering cross sections for fluorine and boron will need to be improved at energies above 1 MeV. Suggestions concerning a strategy to address the specific fusion nuclear data needs for dosimetry and activation are also provided.

  15. NUCLEAR FUSION DEFECTIVE1 encodes the Arabidopsis RPL21M protein and is required for karyogamy during female gametophyte development and fertilization.

    PubMed

    Portereiko, Michael F; Sandaklie-Nikolova, Linda; Lloyd, Alan; Dever, Chad A; Otsuga, Denichiro; Drews, Gary N

    2006-07-01

    Karyogamy, or nuclear fusion, is essential for sexual reproduction. In angiosperms, karyogamy occurs three times: twice during double fertilization of the egg cell and the central cell and once during female gametophyte development when the two polar nuclei fuse to form the diploid central cell nucleus. The molecular mechanisms controlling karyogamy are poorly understood. We have identified nine female gametophyte mutants in Arabidopsis (Arabidopsis thaliana), nuclear fusion defective1 (nfd1) to nfd9, that are defective in fusion of the polar nuclei. In the nfd1 to nfd6 mutants, failure of fusion of the polar nuclei is the only defect detected during megagametogenesis. nfd1 is also affected in karyogamy during double fertilization. Using transmission electron microscopy, we showed that nfd1 nuclei fail to undergo fusion of the outer nuclear membranes. nfd1 contains a T-DNA insertion in RPL21M that is predicted to encode the mitochondrial 50S ribosomal subunit L21, and a wild-type copy of this gene rescues the mutant phenotype. Consistent with the predicted function of this gene, an NFD1-green fluorescent protein fusion protein localizes to mitochondria and the NFD1/RPL21M gene is expressed throughout the plant. The nfd3, nfd4, nfd5, and nfd6 mutants also contain T-DNA insertions in genes predicted to encode proteins that localize to mitochondria, suggesting a role for this organelle in nuclear fusion.

  16. Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

    PubMed

    Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

    2012-03-01

    Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion.

  17. Different patterns of Robertsonian fusion pairing in Bovidae and the house mouse: the relationship between chromosome size and nuclear territories.

    PubMed

    Wesche, Philipp L; Robinson, Terence J

    2012-04-01

    Using a dataset of karyotypic changes reported for bovids and the house mouse (Mus musculus domesticus) together with information from the cattle (Bos taurus) and mouse genomes, we examined two principal variables that have been proposed to predict chromosomal positioning in the nucleus, chromosome size and GC content. These were expected to influence the distribution of Robertsonian (Rb) fusions, the predominant mode of chromosomal change in both taxa. We found the largest chromosomes to be most frequently involved in fusions in bovids, and confirm earlier reports that chromosomes of intermediate size were the most frequent fusers in mice. We then tested whether chromosomal positioning can explain Rb fusion frequencies. We classified chromosomes into groups by size and considered the frequency of interactions between specific groups. Among the interactions, mouse chromosomes showed a slight tendency to fuse with neighbouring chromosomes, in line with expectations of chromosomal positioning, but also resembling predictions from meiotic spindle-induced bias. Bovids, on the other hand, showed no trend in interactions, with small chromosomes being the least frequent partner for all size classes. We discuss the results in terms of nuclear organization at various cell cycle stages and the proposed mechanisms of Rb fusion formation, and note that the difference can be explained by (i) considering bovid species generally to be characterized by a greater intermingling of chromosomal size classes than the house mouse, or (ii) by the vastly different timescales underpinning their evolutionary histories.

  18. Nuclear power supplies: their potential and the practical problems to their achievement for space missions

    SciTech Connect

    Colston, B.W.; Brehm, R.L.

    1985-01-01

    The anticipated growth of the space station power requirement provides a good example of the problem the space nuclear power supply developers have to contend with: should a reactor power supply be developed that attempts to be all things to all missions, i.e., is highly flexible in its ability to meet a wide variety of missions, or should the development of a reactor system await a specific mission definition and be customized to this mission. This leads, of course, to a chicken-and-egg situation. For power requirements of several hundreds of kilowatts or more, no nuclear power source exists or is even far enough along in the definition stage (much less the development stage) for NASA to reasonably assume probable availability within the next 10 years. The real problem of space nuclear power is this ''chicken-and-egg'' syndrome: DOE will not develop a space reactor system for NASA without a firm mission, and NASA will not specify a firm mission requiring a space reactor because such a system doesn't exist and is perceived not to be developable within the time frame of the mission. The problem is how to break this cycle. The SP-100 program has taken an important first step to breaking this cycle, but this program is much more design-specific than what is required to achieve a broad technology base and latitude in achievable power level. In contrast to the SP-100 approach, a wider perspective is required: the development of the appropriate technologies for power levels can be broken into ranges, say, from 100 kWe to 1000 kWe, and from 1000 kWe to 10,000 kWe.

  19. Double-Pionic Fusion of Nuclear Systems and the 'ABC' Effect: Approaching a Puzzle by Exclusive and Kinematically Complete Measurements

    SciTech Connect

    Bashkanov, M.; Clement, H.; Doroshkevich, E.; Khakimova, O.; Kren, F.; Meier, R.; Pricking, A.; Skorodko, T.; Wagner, G. J.; Bargholtz, C.; Geren, L.; Lindberg, K.; Tegner, P.-E.; Zartova, I.; Berlowski, M.; Stepaniak, J.; Bogoslawsky, D.; Ivanov, G.; Jiganov, E.; Morosov, B.

    2009-02-06

    The ABC effect--a puzzling low-mass enhancement in the {pi}{pi} invariant mass spectrum, first observed by Abashian, Booth, and Crowe--is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn{yields}d{pi}{sup 0}{pi}{sup 0} at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a ({pi}{pi}){sub I=L=0} channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a {delta}{delta} system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data.

  20. Leukemia-Associated Nup214 Fusion Proteins Disturb the XPO1-Mediated Nuclear-Cytoplasmic Transport Pathway and Thereby the NF-κB Signaling Pathway

    PubMed Central

    Cigdem, Sadik; Okuwaki, Mitsuru; Nagata, Kyosuke

    2016-01-01

    Nuclear-cytoplasmic transport through nuclear pore complexes is mediated by nuclear transport receptors. Previous reports have suggested that aberrant nuclear-cytoplasmic transport due to mutations or overexpression of nuclear pore complexes and nuclear transport receptors is closely linked to diseases. Nup214, a component of nuclear pore complexes, has been found as chimeric fusion proteins in leukemia. Among various Nup214 fusion proteins, SET-Nup214 and DEK-Nup214 have been shown to be engaged in tumorigenesis, but their oncogenic mechanisms remain unclear. In this study, we examined the functions of the Nup214 fusion proteins by focusing on their effects on nuclear-cytoplasmic transport. We found that SET-Nup214 and DEK-Nup214 interact with exportin-1 (XPO1)/CRM1 and nuclear RNA export factor 1 (NXF1)/TAP, which mediate leucine-rich nuclear export signal (NES)-dependent protein export and mRNA export, respectively. SET-Nup214 and DEK-Nup214 decreased the XPO1-mediated nuclear export of NES proteins such as cyclin B and proteins involved in the NF-κB signaling pathway by tethering XPO1 onto nuclear dots where Nup214 fusion proteins are localized. We also demonstrated that SET-Nup214 and DEK-Nup214 expression inhibited NF-κB-mediated transcription by abnormal tethering of the complex containing p65 and its inhibitor, IκB, in the nucleus. These results suggest that SET-Nup214 and DEK-Nup214 perturb the regulation of gene expression through alteration of the nuclear-cytoplasmic transport system. PMID:27114368

  1. Leukemia-Associated Nup214 Fusion Proteins Disturb the XPO1-Mediated Nuclear-Cytoplasmic Transport Pathway and Thereby the NF-κB Signaling Pathway.

    PubMed

    Saito, Shoko; Cigdem, Sadik; Okuwaki, Mitsuru; Nagata, Kyosuke

    2016-07-01

    Nuclear-cytoplasmic transport through nuclear pore complexes is mediated by nuclear transport receptors. Previous reports have suggested that aberrant nuclear-cytoplasmic transport due to mutations or overexpression of nuclear pore complexes and nuclear transport receptors is closely linked to diseases. Nup214, a component of nuclear pore complexes, has been found as chimeric fusion proteins in leukemia. Among various Nup214 fusion proteins, SET-Nup214 and DEK-Nup214 have been shown to be engaged in tumorigenesis, but their oncogenic mechanisms remain unclear. In this study, we examined the functions of the Nup214 fusion proteins by focusing on their effects on nuclear-cytoplasmic transport. We found that SET-Nup214 and DEK-Nup214 interact with exportin-1 (XPO1)/CRM1 and nuclear RNA export factor 1 (NXF1)/TAP, which mediate leucine-rich nuclear export signal (NES)-dependent protein export and mRNA export, respectively. SET-Nup214 and DEK-Nup214 decreased the XPO1-mediated nuclear export of NES proteins such as cyclin B and proteins involved in the NF-κB signaling pathway by tethering XPO1 onto nuclear dots where Nup214 fusion proteins are localized. We also demonstrated that SET-Nup214 and DEK-Nup214 expression inhibited NF-κB-mediated transcription by abnormal tethering of the complex containing p65 and its inhibitor, IκB, in the nucleus. These results suggest that SET-Nup214 and DEK-Nup214 perturb the regulation of gene expression through alteration of the nuclear-cytoplasmic transport system.

  2. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  3. Fusion, magnetic confinement

    SciTech Connect

    Berk, H.L.

    1992-08-06

    An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or {sup 3}He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied.

  4. Petawatt laser pulses for proton-boron high gain fusion with avalanche reactions excluding problems of nuclear radiation

    NASA Astrophysics Data System (ADS)

    Hora, Heinrich; Lalousis, Paraskevas; Giuffrida, Lorenzo; Margarone, Daniele; Korn, Georg; Eliezer, Shalom; Miley, George H.; Moustaizis, Stavros; Mourou, Gérard

    2015-05-01

    An alternative way may be possible for igniting solid density hydrogen-11B (HB11) fuel. The use of >petawatt-ps laser pulses from the non-thermal ignition based on ultrahigh acceleration of plasma blocks by the nonlinear (ponderomotive) force, has to be combined with the measured ultrahigh magnetic fields in the 10 kilotesla range for cylindrical trapping. The evaluation of measured alpha particles from HB11 reactions arrives at the conclusion that apart from the usual binary nuclear reactions, secondary reactions by an avalanche multiplication may cause the high gains, even much higher than from deuterium tritium fusion. This may be leading to a concept of clean economic power generation.

  5. Fusion between Intestinal epithelial cells and macrophages in a cancer context results in nuclear reprogramming.

    PubMed

    Powell, Anne E; Anderson, Eric C; Davies, Paige S; Silk, Alain D; Pelz, Carl; Impey, Soren; Wong, Melissa H

    2011-02-15

    The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial-mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells.

  6. Prolonged interval between fusion and activation impairs embryonic development by inducing chromosome scattering and nuclear aneuploidy in pig somatic cell nuclear transfer.

    PubMed

    You, Jinyoung; Song, Kilyoung; Lee, Eunsong

    2010-01-01

    The aim of the present study was to examine the effect of various intervals between electrofusion and activation (FA interval) on the nuclear remodelling and development of somatic cell nuclear transfer (SCNT) embryos in pigs. Reconstructed oocytes were activated at 0 (simultaneous fusion and activation; SFA), 1, 2 and 3 h (delayed activation) after electrofusion; these groups were designated as DA1, DA2 and DA3, respectively. When oocyte nuclear status was examined at 0.5, 1, 2 and 3 h after electrofusion, the incidence of chromosome scattering was increased (P < 0.01) as the FA interval was extended (0.0%, 12.0%, 77.3% and 78.0%, respectively). Extending the FA interval led to an increase (P < 0.01) in the percentage of oocytes containing multiple (>or=3) pseudopronuclei (PPN) (0.0% of SFA; 5.3% of DA1; 21.7% of DA2; and 33.5% of DA3). The development of SCNT embryos to the blastocyst stage was decreased (P < 0.05) in DA2 (5.7%) and DA3 (5.0%) compared with SFA (18.1%) and DA1 (19.5%). Our results demonstrate that extending the FA interval impairs the development of SCNT pig embryos by inducing chromosome scattering and the formation of multiple PPN, which may result in increased nuclear aneuploidy.

  7. The nuclear dynamo; Can a nuclear tornado annihilate nations

    SciTech Connect

    McNally, J.R. Jr.

    1991-01-01

    This paper reports on the development of the hypothesis of a nuclear dynamo for a controlled nuclear fusion reactor. This dynamo hypothesis suggests properties for a nuclear tornado that could annihilate nations if accidentally triggered by a single high yield to weight nuclear weapon detonation. The formerly classified reports on ignition of the atmosphere, the properties of a nuclear dynamo, methods to achieve a nuclear dynamo in the laboratory, and the analogy of a nuclear dynamo to a nuclear tornado are discussed. An unclassified international study of this question is urged.

  8. Meningeal hemangiopericytoma and solitary fibrous tumors carry the NAB2-STAT6 fusion and can be diagnosed by nuclear expression of STAT6 protein.

    PubMed

    Schweizer, Leonille; Koelsche, Christian; Sahm, Felix; Piro, Rosario M; Capper, David; Reuss, David E; Pusch, Stefan; Habel, Antje; Meyer, Jochen; Göck, Tanja; Jones, David T W; Mawrin, Christian; Schittenhelm, Jens; Becker, Albert; Heim, Stephanie; Simon, Matthias; Herold-Mende, Christel; Mechtersheimer, Gunhild; Paulus, Werner; König, Rainer; Wiestler, Otmar D; Pfister, Stefan M; von Deimling, Andreas

    2013-05-01

    Non-central nervous system hemangiopericytoma (HPC) and solitary fibrous tumor (SFT) are considered by pathologists as two variants of a single tumor entity now subsumed under the entity SFT. Recent detection of frequent NAB2-STAT6 fusions in both, HPC and SFT, provided additional support for this view. On the other hand, current neuropathological practice still distinguishes between HPC and SFT. The present study set out to identify genes involved in the formation of meningeal HPC. We performed exome sequencing and detected the NAB2-STAT6 fusion in DNA of 8/10 meningeal HPC thereby providing evidence of close relationship of these tumors with peripheral SFT. Due to the considerable effort required for exome sequencing, we sought to explore surrogate markers for the NAB2-STAT6 fusion protein. We adopted the Duolink proximity ligation assay and demonstrated the presence of NAB2-STAT6 fusion protein in 17/17 HPC and the absence in 15/15 meningiomas. More practical, presence of the NAB2-STAT6 fusion protein resulted in a strong nuclear signal in STAT6 immunohistochemistry. The nuclear reallocation of STAT6 was detected in 35/37 meningeal HPC and 25/25 meningeal SFT but not in 87 meningiomas representing the most important differential diagnosis. Tissues not harboring the NAB2-STAT6 fusion protein presented with nuclear expression of NAB2 and cytoplasmic expression of STAT6 proteins. In conclusion, we provide strong evidence for meningeal HPC and SFT to constitute variants of a single entity which is defined by NAB2-STAT6 fusion. In addition, we demonstrate that this fusion can be rapidly detected by STAT6 immunohistochemistry which shows a consistent nuclear reallocation. This immunohistochemical assay may prove valuable for the differentiation of HPC and SFT from other mesenchymal neoplasms.

  9. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

    NASA Astrophysics Data System (ADS)

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-01

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  10. Mini Fission-Fusion-Fission Explosions (Mini-Nukes). A Third Way Towards the Controlled Release of Nuclear Energy by Fission and Fusion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2004-06-01

    Chemically ignited nuclear microexplosions with a fissile core, a DT reflector and U238 (Th232) pusher, offer a promising alternative to magnetic and inertial confinement fusion, not only burning DT, but in addition U238 (or Th232), and not depending on a large expensive laser of electric pulse power supply. The prize to be paid is a gram size amount of fissile material for each microexplosion, but which can be recovered by breeding in U238. In such a "mini-nuke" the chemical high explosive implodes a spherical metallic shell onto a smaller shell, with the smaller shell upon impact becoming the source of intense black body radiation which vaporizes the ablator of a spherical U238 (Th232) pusher, with the pusher accelerated to a velocity of ˜200 km/s, sufficient to ignite the DT gas placed in between the pusher and fissile core, resulting in a fast fusion neutron supported fission reaction in the core and pusher. Estimates indicate that a few kg of high explosives are sufficient to ignite such a "mini-nuke", with a gain of ˜103, releasing an energy equivalent to a few tons of TNT, still manageable for the microexplosion to be confined in a reactor vessel. A further reduction in the critical mass is possible by replacing the high explosive with fast moving solid projectiles. For light gas gun driven projectiles with a velocity of ˜ 10 km/s, the critical mass is estimated to be 0.25 g, and for magnetically accelerated 25 km/s projectiles it is as small as ˜ 0.05 g. With the much larger implosion velocities, reached by laser- or particle beam bombardment of the outer shell, the critical mass can still be much smaller with the fissile core serving as a fast ignitor. Increasing the implosion velocity decreases the overall radius of the fission-fusion assembly in inverse proportion to this velocity, for the 10 km/s light gas gun driven projectiles from 10 cm to 5 cm, for the 25 km/s magnetically projectiles down to 2 cm, and still more for higher implosion velocities.

  11. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    NASA Astrophysics Data System (ADS)

    Siegel, Edward

    2011-04-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility /factor-ization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 x 2]; (4+1)=(fusion)=5; (5+1)=(fission)=6[=2 x 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 x 4 = 2 x 2 x 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 x 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16,... Could inter-digit Feshbach-resonances exist??? Applications to: quantum-information and computing non-Shore factorization, millennium-problem Riemann-hypotheses physics-proof as numbers/digits Goodkin Bose-Einstein Condensation intersection with graph-theory ``short-cut'' method: Rayleigh(1870)-Polya(1922)-``Anderson'' (1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics;... abound!!!

  12. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    NASA Astrophysics Data System (ADS)

    Siegel, Edward

    2011-10-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility /factor-ization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 × 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 × 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 × 4 = 2 × 2 × 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 × 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16,... Could inter-digit Feshbach-resonances exist??? Applications to: quantum-information/computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory ``short-cut'' method: Rayleigh(1870)-Polya(1922)-``Anderson'' (1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics;... abound!!!

  13. The EWSR1/NR4A3 fusion protein of extraskeletal myxoid chondrosarcoma activates the PPARG nuclear receptor gene.

    PubMed

    Filion, C; Motoi, T; Olshen, A B; Laé, M; Emnett, R J; Gutmann, D H; Perry, A; Ladanyi, M; Labelle, Y

    2009-01-01

    The NR4A3 nuclear receptor is implicated in the development of extraskeletal myxoid chondrosarcoma (EMC), primitive sarcoma unrelated to conventional chondrosarcomas, through a specific fusion with EWSR1 resulting in an aberrant fusion protein that is thought to disrupt the transcriptional regulation of specific target genes. We performed an expression microarray analysis of EMC tumours expressing the EWSR1/NR4A3 fusion protein, comparing their expression profiles to those of other sarcoma types. We thereby identified a set of genes significantly overexpressed in EMC relative to other sarcomas, including PPARG and NDRG2. Western blot or immunohistochemical analyses confirm that PPARG and NDRG2 are expressed in tumours positive for EWSR1/NR4A3. Bioinformatic analysis identified a DNA response element for EWSR1/NR4A3 in the PPARG promoter, and band-shift experiments and transient transfections indicate that EWSR1/NR4A3 can activate transcription through this element. Western blots further show that an isoform of the native NR4A3 receptor lacking the C-terminal domain is very highly expressed in tumours positive for EWSR1/NR4A3, and co-transfections of this isoform along with EWSR1/NR4A3 indicate that it may negatively regulate the activity of the fusion protein on the PPARG promoter. These results suggest that the overall expression of PPARG in EMC may be regulated in part by the balance between EWSR1/NR4A3 and NR4A3, and that PPARG may play a crucial role in the development of these tumours. The specific up-regulation of PPARG by EWSR1/NR4A3 may also have potential therapeutic implications.

  14. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-04-20

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

  15. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-02-22

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

  16. The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export.

    PubMed

    Port, Sarah A; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H

    2016-10-28

    Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A)(+) RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A)(+) RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors.

  17. Comment on: Deuterium nuclear fusion at room temperature: A pertinent inequality on barrier penetration

    SciTech Connect

    Morgan, J.D. III Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA )

    1990-10-15

    Gerald Rosen claims to justify the large value apparently observed by Fleischman and Pons and also by Jones {ital et} {ital al}., in their experiments on cold fusion. Rosen derives an inequality for the Coulomb barrier penetration factor. This comment points out a crucial error in his derivation. (AIP)

  18. 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.

  19. A multi-temporal fusion-based approach for land cover mapping in support of nuclear incident response

    NASA Astrophysics Data System (ADS)

    Sah, Shagan

    An increasingly important application of remote sensing is to provide decision support during emergency response and disaster management efforts. Land cover maps constitute one such useful application product during disaster events; if generated rapidly after any disaster, such map products can contribute to the efficacy of the response effort. In light of recent nuclear incidents, e.g., after the earthquake/tsunami in Japan (2011), our research focuses on constructing rapid and accurate land cover maps of the impacted area in case of an accidental nuclear release. The methodology involves integration of results from two different approaches, namely coarse spatial resolution multi-temporal and fine spatial resolution imagery, to increase classification accuracy. Although advanced methods have been developed for classification using high spatial or temporal resolution imagery, only a limited amount of work has been done on fusion of these two remote sensing approaches. The presented methodology thus involves integration of classification results from two different remote sensing modalities in order to improve classification accuracy. The data used included RapidEye and MODIS scenes over the Nine Mile Point Nuclear Power Station in Oswego (New York, USA). The first step in the process was the construction of land cover maps from freely available, high temporal resolution, low spatial resolution MODIS imagery using a time-series approach. We used the variability in the temporal signatures among different land cover classes for classification. The time series-specific features were defined by various physical properties of a pixel, such as variation in vegetation cover and water content over time. The pixels were classified into four land cover classes - forest, urban, water, and vegetation - using Euclidean and Mahalanobis distance metrics. On the other hand, a high spatial resolution commercial satellite, such as RapidEye, can be tasked to capture images over the

  20. Refined Calculations of Secondary Nuclear Reactions in Magneto-Inertial Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Schmit, Paul; Knapp, Patrick; Hansen, Stephanie; Gomez, Matthew; Hahn, Kelly; Sinars, Daniel; Peterson, Kyle; Slutz, Stephen; Sefkow, Adam; Awe, Thomas; Harding, Eric; Jennings, Christopher

    2014-10-01

    Diagnosing the degree of magnetic flux compression at stagnation in magneto-inertial fusion (MIF) is critical for charting the performance of any MIF concept. In pure deuterium plasma, the transport of high-energy tritons produced by the aneutronic DD fusion reaction depends strongly on the magnetic field. The tritons probe and occasionally react with the fuel, emitting secondary DT neutrons. We show that the DT/DD neutron yield ratio and the secondary DT neutron spectra can be used to infer the magnetic field-radius product (BR), the critical confinement parameter for MIF. The amount of fuel-pusher mix also can be constrained by secondary reactions. We discuss the sensitivity to plasma inhomogeneities of the calculations and outline methods to relate secondary yields to alpha particle energy deposition in ignition-relevant experiments employing DT fuel. We compare our calculations to recent tests of the Magnetized Liner Inertial Fusion (MagLIF) concept on the Z Pulsed Power Facility. Supported in part by the SNL Truman Fellowship, which is part of the LDRD Program, and sponsored by Sandia Corporation (a wholly owned subsidiary of Lockheed Martin Corporation) as Operator of SNL under its U.S. DoE Contract No. DE-AC04-94AL85000.

  1. Ensuring safe and quality medication use in nuclear medicine: a collaborative team achieves compliance with medication management standards.

    PubMed

    Beach, Trent A; Griffith, Karen; Dam, Hung Q; Manzone, Timothy A

    2012-03-01

    As hospital nuclear medicine departments were established in the 1960s and 1970s, each department developed detailed policies and procedures to meet the specialized and specific handling requirements of radiopharmaceuticals. In many health systems, radiopharmaceuticals are still unique as the only drugs not under the control of the health system pharmacy; however, the clear trend--and now an accreditation requirement--is to merge radiopharmaceutical management with the overall health system medication management system. Accomplishing this can be a challenge for both nuclear medicine and pharmacy because each lacks knowledge of the specifics and needs of the other field. In this paper we will first describe medication management standards, what they cover, and how they are enforced. We will describe how we created a nuclear medicine and pharmacy team to achieve compliance, and we will present the results of their work. We will examine several specific issues raised by incorporating radiopharmaceuticals in the medication management process and describe how our team addressed those issues. Finally, we will look at how the medication management process helps ensure ongoing quality and safety to patients through multiple periodic reviews. The reader will gain an understanding of medication management standards and how they apply to nuclear medicine, learn how a nuclear medicine and pharmacy team can effectively merge nuclear medicine and pharmacy processes, and gain the ability to achieve compliance at the reader's own institution.

  2. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 2: Power from nuclear fission

    NASA Technical Reports Server (NTRS)

    Clement, J. D.

    1973-01-01

    Different types of nuclear fission reactors and fissionable materials are compared. Special emphasis is placed upon the environmental impact of such reactors. Graphs and charts comparing reactor facilities in the U. S. are presented.

  3. Production of cloned dogs by decreasing the interval between fusion and activation during somatic cell nuclear transfer.

    PubMed

    Kim, Sue; Park, Sun Woo; Hossein, Mohammad Shamim; Jeong, Yeon Woo; Kim, Joung Joo; Lee, Eugine; Kim, Yeun Wook; Hyun, Sang Hwan; Shin, Taeyoung; Hwang, Woo Suk

    2009-05-01

    To improve the efficiency of somatic cell nuclear transfer (SCNT) in dogs, we evaluated whether or not the interval between fusion and activation affects the success rate of SCNT. Oocytes retrieved from outbred dogs were reconstructed with adult somatic cells from a male or female Golden Retriever. In total, 151 and 225 reconstructed oocytes were transferred to 9 and 14 naturally synchronized surrogates for male and female donor cells, respectively. Chromosomal morphology was evaluated in 12 oocytes held for an interval of 2 hr between fusion and activation and 14 oocytes held for an interval of 4 hr. Three hundred seventy-six and 288 embryos were transferred to 23 and 16 surrogates for the 2 and 4 hr interval groups, respectively. Both the male (two pregnant surrogates gave birth to three puppies) and female (one pregnant surrogate gave birth to one puppy) donor cells gave birth to live puppies (P > 0.05). In the 2 hr group, significantly more reconstructed oocytes showed condensed, metaphase-like chromosomes compared to the 4 hr group (P < 0.05). A significantly higher pregnancy rate and a greater number of live born puppies were observed in the 2 hr group (13.0% and 1.1%, respectively) compared to the 4 hr group (0%) (P < 0.05). In total, three surrogate dogs carried pregnancies to term and four puppies were born. These results demonstrate that decreasing the interval between fusion and activation increases the success rate of clone production and pregnancy. These results may increase the overall efficiency of SCNT in the canine family.

  4. EFFECTS OF NUCLEAR INDUCED BREAKUP ON THE FUSION OF 6Li+12C AND 6He+12C SYSTEMS AROUND BARRIER ENERGIES

    NASA Astrophysics Data System (ADS)

    Duhan, Sukhvinder S.; Singh, Manjeet; Kharab, Rajesh

    2012-06-01

    We have studied the effects of nuclear induced breakup channel coupling on the fusion cross-section for 6Li+12C and 6He+12C systems in the near barrier energy regime using the dynamic polarization potential (DPP) approach. It has been found that there is enhancement in the fusion cross-section with respect to standard one-dimensional barrier penetration model in the below barrier energy regime while at energies above the barrier there is suppression of fusion cross-section with respect to simple barrier penetration model is observed. The agreement between data and predictions for 6Li+12C system improves significantly as a result of the inclusion of nuclear induced DPP.

  5. Office of Basic Energy Sciences program to meet high priority nuclear data needs of the Office of Fusion Energy 1983 review

    SciTech Connect

    Haight, R.C.; Larson, D.C.

    1983-11-01

    This review was prepared during a coordination meeting held at Oak Ridge National Laboratory on September 28-29, 1983. Participants included research scientists working for this program, a representative from the OFE's Coordination of Magnetic Fusion Energy (MFE) Nuclear Data Needs Activities, and invited specialists.

  6. Herpes simplex virus glycoproteins gB and gH function in fusion between the virion envelope and the outer nuclear membrane.

    PubMed

    Farnsworth, Aaron; Wisner, Todd W; Webb, Michael; Roller, Richard; Cohen, Gary; Eisenberg, Roselyn; Johnson, David C

    2007-06-12

    Herpesviruses must traverse the nuclear envelope to gain access to the cytoplasm and, ultimately, to exit cells. It is believed that herpesvirus nucleocapsids enter the perinuclear space by budding through the inner nuclear membrane (NM). To reach the cytoplasm these enveloped particles must fuse with the outer NM and the unenveloped capsids then acquire a second envelope in the trans-Golgi network. Little is known about the process by which herpesviruses virions fuse with the outer NM. Here we show that a herpes simplex virus (HSV) mutant lacking both the two putative fusion glycoproteins gB and gH failed to cross the nuclear envelope. Enveloped virions accumulated in the perinuclear space or in membrane vesicles that bulged into the nucleoplasm (herniations). By contrast, mutants lacking just gB or gH showed only minor or no defects in nuclear egress. We concluded that either HSV gB or gH can promote fusion between the virion envelope and the outer NM. It is noteworthy that fusion associated with HSV entry requires the cooperative action of both gB and gH, suggesting that the two types of fusion (egress versus entry) are dissimilar processes.

  7. Expansion of nanoplasmas and laser-driven nuclear fusion in single exploding clusters

    SciTech Connect

    Peano, F.; Martins, J. L.; Silva, L. O.; Peinetti, F.; Mulas, R.; Coppa, G.

    2008-09-07

    The expansion of laser-irradiated clusters can be controlled by acting on the amount of energy delivered to the electrons. When increasing the electron energy, the expansion regime varies smoothly from a quasineutral, hydrodinamic-like to a Coulomb explosion (CE), as revealed by self-consistent kinetic analysis. A double-pump irradiation scheme can produce hybrid expansion regimes wherein a slow hydrodynamic expansion is followed by a fast CE, leading to ion overtaking and producing multiple ion flows expanding with different velocities, which can lead to intracluster fusion reactions in homonuclear deuterium clusters.

  8. Deuterium nuclear fusion at room temperature: A pertinent inequality on barrier penetration

    SciTech Connect

    Rosen, G. )

    1989-10-01

    For a D{sub 2} molecule with linear vibrational energy {ital E}, it is shown that {lambda}({ital E}) in the WKB {ital d}--{ital d} fusion rate expression {Lambda}({ital E}){congruent}(5.7{times}10{sup 8} s{sup {minus}1})(exp{minus}{lambda}({ital E})) satisfies a useful scaling inequality. It follows from this inequality that {Lambda}({ital E}){approx gt}2.8{times}10{sup {minus}20} s{sup {minus}1} for a lattice-caged D{sub 2} with vibrational energy {ital E}=9.0 eV.

  9. Spindle pole body-anchored Kar3 drives the nucleus along microtubules from another nucleus in preparation for nuclear fusion during yeast karyogamy.

    PubMed

    Gibeaux, Romain; Politi, Antonio Z; Nédélec, François; Antony, Claude; Knop, Michael

    2013-02-01

    Nuclear migration during yeast karyogamy, termed nuclear congression, is required to initiate nuclear fusion. Congression involves a specific regulation of the microtubule minus end-directed kinesin-14 motor Kar3 and a rearrangement of the cytoplasmic microtubule attachment sites at the spindle pole bodies (SPBs). However, how these elements interact to produce the forces necessary for nuclear migration is less clear. We used electron tomography, molecular genetics, quantitative imaging, and first principles modeling to investigate how cytoplasmic microtubules are organized during nuclear congression. We found that Kar3, with the help of its light chain, Cik1, is anchored during mating to the SPB component Spc72 that also serves as a nucleator and anchor for microtubules via their minus ends. Moreover, we show that no direct microtubule-microtubule interactions are required for nuclear migration. Instead, SPB-anchored Kar3 exerts the necessary pulling forces laterally on microtubules emanating from the SPB of the mating partner nucleus. Therefore, a twofold symmetrical application of the core principle that drives nuclear migration in higher cells is used in yeast to drive nuclei toward each other before nuclear fusion.

  10. Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions

    SciTech Connect

    Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.; Santarius, J. F.; Piefer, G. R.

    2013-03-15

    A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage ({approx}100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

  11. Improved efficacy of soluble human receptor activator of nuclear factor kappa B (RANK) fusion protein by site-directed mutagenesis.

    PubMed

    Son, Young Jun; Han, Jihye; Lee, Jae Yeon; Kim, HaHyung; Chun, Taehoon

    2015-06-01

    Soluble human receptor activator of nuclear factor kappa B fusion immunoglobulin (hRANK-Ig) has been considered as one of the therapeutic agents to treat osteoporosis or diseases associated with bone destruction by blocking the interaction between RANK and the receptor activator of nuclear factor kappa B ligand (RANKL). However, no scientific record showing critical amino acid residues within the structural interface between the human RANKL and RANK complex is yet available. In this study, we produced several mutants of hRANK-Ig by replacement of amino acid residue(s) and tested whether the mutants had increased binding affinity to human RANKL. Based on the results from flow cytometry and surface plasmon resonance analyses, the replacement of E(125) with D(125), or E(125) and C(127) with D(125) and F(127) within loop 3 of cysteine-rich domain 3 of hRANK-Ig increases binding affinity to human RANKL over the wild-type hRANK-Ig. This result may provide the first example of improvement in the efficacy of hRANK-Ig by protein engineering and may give additional information to understand a more defined structural interface between hRANK and RANKL.

  12. Cold-fusion television show angers APS

    NASA Astrophysics Data System (ADS)

    Cartwright, Jon

    2009-06-01

    Cold fusion has been controversial since its inception on 23 March 1989, when chemists Martin Fleischmann and Stanley Pons at the University of Utah in the US announced that they had achieved a sustained nuclear-fusion reaction at room temperature. Two decades on, a US television documentary about the field has stirred up fresh debate after it linked the American Physical Society (APS) to an evaluation of some cold-fusion results by Robert Duncan, a physicist and vice chancellor of the University of Missouri.

  13. 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.

  14. Nuclear performance optimization of the Be/Li/Th blanket for the fusion breeder

    SciTech Connect

    Lee, J.D.; Bandini, B.R.

    1985-02-26

    More rigorous nuclear analysis, including treatment of resonance self-shielding effects coupled with an optimization procedure, has resulted in improved performance of the Be/Li/Th blanket. Net U-233 breeding ratio has increased 36% (to 0.84) while at an average U-233/Th ratio of 0.5 a/o average energy multiplication has increased only 12% (to 2.1) compared with earlier results.

  15. The Malleable Nature of the Budding Yeast Nuclear Envelope: Flares, Fusion, and Fenestrations.

    PubMed

    Meseroll, Rebecca A; Cohen-Fix, Orna

    2016-11-01

    In eukaryotes, the nuclear envelope (NE) physically separates nuclear components and activities from rest of the cell. The NE also provides rigidity to the nucleus and contributes to chromosome organization. At the same time, the NE is highly dynamic; it must change shape and rearrange its components during development and throughout the cell cycle, and its morphology can be altered in response to mutation and disease. Here we focus on the NE of budding yeast, Saccharomyces cerevisiae, which has several unique features: it remains intact throughout the cell cycle, expands symmetrically during interphase, elongates during mitosis and, expands asymmetrically during mitotic delay. Moreover, its NE is safely breached during mating and when large structures, such as nuclear pore complexes and the spindle pole body, are embedded into its double membrane. The budding yeast NE lacks lamins and yet the nucleus is capable of maintaining a spherical shape throughout interphase. Despite these eccentricities, studies of the budding yeast NE have uncovered interesting, and likely conserved, processes that contribute to NE dynamics. In particular, we discuss the processes that drive and enable NE expansion and the dramatic changes in the NE that lead to extensions and fenestrations. J. Cell. Physiol. 231: 2353-2360, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  16. Nuclear potentials for sub-barrier fusion and cluster decay in {sup 14}C, {sup 18}O+{sup 208}Pb systems

    SciTech Connect

    Sagaidak, R. N.; Tretyakova, S. P.; Khlebnikov, S. V.; Ogloblin, A. A.; Rowley, N.; Trzaska, W. H.

    2007-09-15

    Near-barrier fusion excitation functions for the {sup 14}C and {sup 18}O+{sup 208}Pb reactions have been analyzed in the framework of the barrier-passing model using different forms of the nuclear potential and the phenomenology of a fluctuating barrier. The best-fit fusion potentials were used to estimate cluster decay probabilities from the corresponding ground states of Ra and Th (i.e., for the inverse decay process). The analysis supports the ''{alpha}-decay-like'' scenario for carbon and oxygen emission from these nuclei.

  17. Nuclear power supplies: Their potential and the practical problems to their achievement for space missions

    NASA Technical Reports Server (NTRS)

    Colston, B. W.

    1986-01-01

    Various issues associated with getting technology development of nuclear power systems moving at a pace which will support the anticipated need for such systems in later years is discussed. The projected power needs of such advanced space elements as growth space stations and lunar and planetary vehicles and bases are addressed briefly, and the relevance of nuclear power systems is discussed. A brief history and status of the U.S. nuclear reactor systems is provided, and some of the problems (real and/or perceived) are dealt with briefly. Key areas on which development attention should be focused in the near future are identified, and a suggested approach is recommended to help accelerate the process.

  18. Inertial-confinement fusion with lasers

    SciTech Connect

    Betti, R.; Hurricane, O. A.

    2016-05-03

    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 to 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.

  19. Inertial-confinement fusion with lasers

    DOE PAGES

    Betti, R.; Hurricane, O. A.

    2016-05-03

    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 to themore » 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

  20. The High Field Compact Approach in Nuclear Fusion: Present and Foreseeable Developments vs. Damnatio Memoriae

    NASA Astrophysics Data System (ADS)

    Spillantini, P.; Coppi, B.; Grasso, G.

    2016-10-01

    A confirmation of the fact that the most promising approach, in the effort to demonstrate experimentally that fusion burning D-T plasmas can reach near-ignition conditions, is that of high field compact (HFC) machines, has come from recent analyses of confinement experiments conducted over the years. In fact, this approach can be adopted to begin investigations of D-D and D-3 He burning regimes. An important development that can be used in these experiments is that of high field super-conductor technology. This technology was pioneered with the adoption and design of the largest (vertical field) coils of the Ignitor machine using MgB2 super-conductors cooled to about 10oK. The use of hybrid magnets combining MgB2 and high temperature super-conductors to reach the needed high fields for all the machine components has been proposed also with a specific configuration for envisioned future experiments. A surprising occurrence, related to the ideas at the basis of the HFC machine approach has been the practice of the ``damnatio memoriae'' inflicted on their originators. Sponsored in part by the U.S. D.O.E.

  1. Characterization of scintillator materials for fast-ion loss detectors in nuclear fusion reactors

    NASA Astrophysics Data System (ADS)

    Jiménez-Ramos, M. C.; García López, J.; García-Muñoz, M.; Rodríguez-Ramos, M.; Carmona Gázquez, M.; Zurro, B.

    2014-08-01

    In fusion plasma reactors, fast ion generated by heating systems and fusion born particles must be well confined. The presence of magnetohydrodynamic (MHD) instabilities can lead to a significant loss of these ions, which may reduce drastically the heating efficiency and may cause damage to plasma facing components in the vacuum vessel. In order to understand the physics underlying the fast ion loss mechanism, scintillator based detectors have been installed in several fusion devices. In this work we present the absolute photon yield and its degradation with ion fluence in terms of the number of photons emitted per incident ion of several scintillators thin coatings: SrGa2S4:Eu2+ (TG-Green), Y3Al5O12:Ce3+ (P46) and Y2O3:Eu3+ (P56) when irradiated with light ions of different masses (deuterium ions, protons and α-particles) at energies between approximately 575 keV and 3 MeV. The photon yield will be discussed in terms of the energy deposited by the particles into the scintillator. For that, the actual composition and thickness of the thin layers were determined by Rutherford Backscattering Spectrometry (RBS). A collimator with 1 mm of diameter, which defines the beam size for the experiments, placed at the entrance of the chamber. An electrically isolated sample holder biased to +300 V to collect the secondary electrons, connected to a digital current integrator (model 439 by Ortec) to measure the incident beam current. A home made device has been used to store the real-time evolution of the beam current in a computer file allowing the correction of the IL yields due to the current fluctuations. The target holder is a rectangle of 150 × 112 mm2 and can be tilted. The X and Y movements are controlled through stepping motors, which permits a fine control of the beam spot positioning as well as the study of several samples without venting the chamber. A silica optical fiber of 1 mm diameter fixed to the vacuum chamber, which collects the light from the scintillators

  2. Effects of nuclear orientation on fusion and fission process for reactions using actinide target nuclei

    SciTech Connect

    Nishio, K.; Ikezoe, H.; Mitsuoka, S.; Nishinaka, I.; Makii, H.; Nagame, Y.; Watanabe, Y.; Ohtsuki, T.; Hirose, K.; Hofmann, S.

    2010-04-30

    Fission fragment mass distributions in the reaction of {sup 30}Si+{sup 238}U were measured at the energies around the Coulomb barrier. At the above-barrier energies, the mass distribution showed Gaussian shape. At the sub-barrier energies, triple-humped distribution was observed, which consists of symmetric fission and asymmetric fission peaked at A{sub L}/A{sub H}approx =90/178. The asymmetric fission should be attributed to quasifission from the results of the measured evaporation residue (ER) cross-sections produced by {sup 30}Si+{sup 238}U. The cross-section for {sup 263}Sg at the above-barrier energy agree with the statistical model calculation which assumes that the measured fission cross-sections are equal to the fusion cross-sections, whereas the one for {sup 264}Sg measured at the sub-barrier energy is smaller than the calculation, indicating the presence for quasifission. We also report the results on the fragment mass distributions for {sup 36,34}S+{sup 238}U and {sup 40}Ar+{sup 238}U.

  3. A viable process for producing hydrogen synfuel using nuclear fusion heat

    NASA Astrophysics Data System (ADS)

    Galloway, T. R.; Brown, L. C.

    Analytical and costing analyses of a thermochemical water splitting plant powered by a tandem mirror fusion reactor are presented. Design criteria indicated directing high quality steam to the chemical plant, where no liquid metal coolants would be used. Minimal pumping distances for high pressure He, multiple barriers between the neutron-activated blanket and the hydrogen product, and modular construction where possible are necessary. A He-Brayton topping cycle, coupled to a steam-Rankine bottoming cycle are selected. Slightly over 1111 MWt and about 720 MWe could be produced by the plant if all low grade waste heat is directed to the Rankine cycle. SO3 is used with water for the splitting process, then recombined. H2 is siphoned off as a fuel and O2 is delivered to a coal reforming plant. A 30 yr plant life is projected, operating at a 70% thermal efficiency for the splitting process and producing H2 at $10-12/GJ. The plant is expected to become economically viable in the year 2030 if debt financing is available at 12.25% per year.

  4. HES6 reverses nuclear reprogramming of insulin-producing cells following cell fusion

    SciTech Connect

    Ball, Andrew J.; Abrahamsson, Annelie E.; Tyrberg, Bjoern; Itkin-Ansari, Pamela; Levine, Fred; E-mail: flevine@ucsd.edu

    2007-04-06

    To examine the mechanism by which growth-stimulated pancreatic {beta}-cells dedifferentiate, somatic cell fusions were performed between MIN6, a highly differentiated mouse insulinoma, and {beta}lox5, a cell line derived from human {beta}-cells which progressively dedifferentiated in culture. MIN6/{beta}lox5 somatic cells hybrids underwent silencing of insulin expression and a marked decline in PDX1, NeuroD, and MafA, indicating that {beta}lox5 expresses a dominant transacting factor(s) that represses {beta}-cell differentiation. Expression of Hes1, which inhibits endocrine differentiation was higher in hybrid cells than in parental MIN6 cells. Hes6, a repressor of Hes1, was highly expressed in primary {beta}-cells as well as MIN6, but was repressed in hybrids. Hes6 overexpression using a retroviral vector led to a decrease in Hes1 levels, an increase in {beta}-cell transcription factors and partial restoration of insulin expression. We conclude that the balance of Notch activators and inhibitors may play an important role in maintaining the {beta}-cell differentiated state.

  5. Perspective for special Gurdon issue for differentiation: can cell fusion inform nuclear reprogramming?

    PubMed

    Burns, David; Blau, Helen M

    2014-07-01

    Nuclear reprogramming was first shown to be possible by Sir John Gurdon over a half century ago. The process has been revolutionized by the production of induced pluripotent cells by overexpression of the four transcription factors discovered by Shinya Yamanaka, which now enables mammalian applications. Yet, reprogramming by a few transcription factors remains incomplete and inefficient, whether to pluripotent or differentiated cells. We propose that a better understanding of mechanistic insights based on developmental principles gained from heterokaryon studies may inform the process of directing cell fate, fundamentally and clinically.

  6. Particle-beam fusion research facilities at Sandia National Laboratories

    SciTech Connect

    1980-12-31

    Sandia research in inertial-confinement fusion (ICF) is based on pulse-power capabilities that grew out of earlier developments of intense relativistic electron-beam (e-beam) radiation sources for weapon effects studies. ICF involves irradiating a deuterium-tritium pellet with either laser light or particle beams until the center of the pellet is compressed and heated to the point of nuclear fusion. This publication focuses on the use of particle beams to achieve fusion, and on the various facilities that are used in support of the particle-beam fusion (PBF) program.

  7. Attitudes toward Nuclear Energy: One Potential Path for Achieving Scientific Literacy.

    ERIC Educational Resources Information Center

    Dulski, Richard E.; And Others

    1995-01-01

    Identifies the attitudes of secondary school students toward several science-related topical areas (i.e., nuclear energy, environmental issues, energy concepts, science concepts, space exploration, and metrication) for the purpose of enhancing students' attitudinal development toward science-related topical areas. Discusses respondents attitude…

  8. The Role of Nuclear Power in Achieving the World We Want

    ERIC Educational Resources Information Center

    Driscoll, M. J.

    1970-01-01

    Supports the development of nuclear power plants and considers some problems and possible solutions: future power needs, power costs, thermal pollution, radionuclide discharge. Describes advantages and applications of dual purpose power plants for purifying water, producing phosphorus and ammonia, and serving as fast breeder reactors for Pu 239.…

  9. 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

  10. Hybrid fusion-fission reactor with a thorium blanket: Its potential in the fuel cycle of nuclear reactors

    NASA Astrophysics Data System (ADS)

    Shmelev, A. N.; Kulikov, G. G.; Kurnaev, V. A.; Salahutdinov, G. H.; Kulikov, E. G.; Apse, V. A.

    2015-12-01

    Discussions are currently going on as to whether it is suitable to employ thorium in the nuclear fuel cycle. This work demonstrates that the 231Pa-232U-233U-Th composition to be produced in the thorium blanket of a hybrid thermonuclear reactor (HTR) as a fuel for light-water reactors opens up the possibility of achieving high, up to 30% of heavy metals (HM), or even ultrahigh fuel burnup. This is because the above fuel composition is able to stabilize its neutron-multiplying properties in the process of high fuel burnup. In addition, it allows the nuclear fuel cycle (NFC) to be better protected against unauthorized proliferation of fissile materials owing to an unprecedentedly large fraction of 232U (several percent!) in the uranium bred from the Th blanket, which will substantially hamper the use of fissile materials in a closed NFC for purposes other than power production.

  11. Sixth coordination meeting of the Division of Nuclear Physics Program to meet high-priority nuclear data needs of the Office of Fusion Energy

    SciTech Connect

    Not Available

    1990-06-01

    The Sixth Coordination Meeting of the Program to Meet Nuclear Data Needs for Fusion Energy was held in Athens, September 19--21, 1989. The principal change from the previous meeting at Argonne was the larger international participation. One scientist from Japan represented the only non-US participation at Argonne. The present meeting included about 20% non-US participants. This change is a welcome one since the data needs are international and the limited availability of manpower and facilities will likely make international cooperation increasingly important in the future. The organization of the meeting involved collecting and distributing to all participants progress reports from the Department of Energy laboratories in advance of the meeting. Twenty-five oral presentations were made at the meeting, including many from non-DOE labs. The meeting then divided into experimental and theoretical task force groups, which carried out assigned agenda items. The reports of these groups, abstracts of the talks presented at the meeting, and the progress reports are included in this report. The topics discussed will be very familiar to participants in past meetings, but continued progress in most areas was reported. One discussion topic which reflects continuing and perhaps worsening problems was the aging of facilities and personnel, coupled with a lack of programs to renew.

  12. Neutronic Model of a Mirror Based Fusion-Fission Hybrid for the Incineration of Spent Nuclear Fuel and with Potential for Energy Amplification

    NASA Astrophysics Data System (ADS)

    Noack, Klaus; Moiseenko, V. E.; Agren, O.; Hagnestall, A.

    2010-11-01

    In the last decade the Georgia Institute of Technology (Georgia Tech) published several design concepts of tokamak based fusion-fission hybrids which use solid fuels consisting of transuranic elements of the spent nuclear fuel from Light-Water-Reactors. The objectives of the hybrids are the incineration of the transuranic elements and an additional net energy production under the condition of tritium self-sufficiency. The present paper presents a preliminary scientific design of the blanket of a mirror based hybrid which was derived from the results of Monte Carlo neutron transport calculations. The main operation parameters of two hybrid options were specified. One is the analog to Georgia Techs first version of a ``fusion transmutation of waste reactor'' (FTWR) and the other is a possible near-term option which requires minimal fusion power. The latter version shows considerably better performance parameters.

  13. Unconventional approaches to fusion

    SciTech Connect

    Brunelli, B.; Leotta, G.G.

    1982-01-01

    This volume is dedicated to unconventional approaches to fusionthose thermonuclear reactors that, in comparison with Tokamak and other main lines, have received little attention in the worldwide scientific community. Many of the approaches considered are still in the embryonic stages. The authors-an international group of active nuclear scientists and engineers-focus on the parameters achieved in the use of these reactors and on the meaning of the most recent physical studies and their implications for the future. They also compare these approaches with conventional ones, the Tokamak in particular, stressing the non-plasma-physics requirements of fusion reactors. Unconventional compact toroids, linear systems, and multipoles are considered, as are the ''almost conventional'' fusion machines: stellarators, mirrors, reversed-field pinches, and EBT.

  14. Nuclear imaging of the breast: translating achievements in instrumentation into clinical use.

    PubMed

    Hruska, Carrie B; O'Connor, Michael K

    2013-05-01

    Approaches to imaging the breast with nuclear medicine and∕or molecular imaging methods have been under investigation since the late 1980s when a technique called scintimammography was first introduced. This review charts the progress of nuclear imaging of the breast over the last 20 years, covering the development of newer techniques such as breast specific gamma imaging, molecular breast imaging, and positron emission mammography. Key issues critical to the adoption of these technologies in the clinical environment are discussed, including the current status of clinical studies, the efforts at reducing the radiation dose from procedures associated with these technologies, and the relevant radiopharmaceuticals that are available or under development. The necessary steps required to move these technologies from bench to bedside are also discussed.

  15. Nuclear imaging of the breast: Translating achievements in instrumentation into clinical use

    PubMed Central

    Hruska, Carrie B.; O'Connor, Michael K.

    2013-01-01

    Approaches to imaging the breast with nuclear medicine and/or molecular imaging methods have been under investigation since the late 1980s when a technique called scintimammography was first introduced. This review charts the progress of nuclear imaging of the breast over the last 20 years, covering the development of newer techniques such as breast specific gamma imaging, molecular breast imaging, and positron emission mammography. Key issues critical to the adoption of these technologies in the clinical environment are discussed, including the current status of clinical studies, the efforts at reducing the radiation dose from procedures associated with these technologies, and the relevant radiopharmaceuticals that are available or under development. The necessary steps required to move these technologies from bench to bedside are also discussed. PMID:23635248

  16. A novel integrated approach for the hazardous radioactive dust source terms estimation in future nuclear fusion power plants.

    PubMed

    Poggi, L A; Malizia, A; Ciparisse, J F; Gaudio, P

    2016-10-01

    An open issue still under investigation by several international entities working on the safety and security field for the foreseen nuclear fusion reactors is the estimation of source terms that are a hazard for the operators and public, and for the machine itself in terms of efficiency and integrity in case of severe accident scenarios. Source term estimation is a crucial key safety issue to be addressed in the future reactors safety assessments, and the estimates available at the time are not sufficiently satisfactory. The lack of neutronic data along with the insufficiently accurate methodologies used until now, calls for an integrated methodology for source term estimation that can provide predictions with an adequate accuracy. This work proposes a complete methodology to estimate dust source terms starting from a broad information gathering. The wide number of parameters that can influence dust source term production is reduced with statistical tools using a combination of screening, sensitivity analysis, and uncertainty analysis. Finally, a preliminary and simplified methodology for dust source term production prediction for future devices is presented.

  17. 'Papillary' solitary fibrous tumor/hemangiopericytoma with nuclear STAT6 expression and NAB2-STAT6 fusion.

    PubMed

    Ishizawa, Keisuke; Tsukamoto, Yoshitane; Ikeda, Shunsuke; Suzuki, Tomonari; Homma, Taku; Mishima, Kazuhiko; Nishikawa, Ryo; Sasaki, Atsushi

    2016-04-01

    This report describes clinicopathological findings, including genetic data of STAT6, in a solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) of the central nervous system in an 83-year-old woman with a bulge in the left forehead. She noticed it about 5 months before, and it had grown rapidly for the past 1 month. Neuroradiological studies disclosed a well-demarcated tumor that accompanied the destruction of the skull. The excised tumor showed a prominent papillary structure, where atypical cells were compactly arranged along the fibrovascular core ('pseudopapillary'). There was rich vasculature, some of which resembled 'staghorn' vessels. Mitotic figures were occasionally found. Whorls, psammoma bodies, or intra-nuclear pseudoinclusions were not identified. By immunohistochemistry, CD34 was strongly positive in the tumor cells, and STAT6 was localized in their nuclei. By reverse transcription-polymerase chain reaction (RT-PCR), an NAB2-STAT6 fusion gene, NAB2 exon6-STAT6 exon17, was detected, establishing a definite diagnosis of SFT/HPC. 'Papillary' SFT/HPC needs to be recognized as a possible morphological variant of SFT/HPC, and should be borne in mind in its diagnostic practice.

  18. Knockdown of MAP4 and DNAL1 produces a post-fusion and pre-nuclear translocation impairment in HIV-1 replication

    SciTech Connect

    Gallo, Daniel E. Hope, Thomas J.

    2012-01-05

    DNAL1 and MAP4 are both microtubule-associated proteins. These proteins were identified as HIV-1 dependency factors in a screen with wild-type HIV-1. In this study we demonstrate that knockdown using DNAL1 and MAP4 siRNAs and shRNAs inhibits HIV-1 infection regardless of envelope. Using a fusion assay, we show that DNAL1 and MAP4 do not impact fusion. By assaying for late reverse transcripts and 2-LTR circles, we show that DNAL1 and MAP4 inhibit both by approximately 50%. These results demonstrate that DNAL1 and MAP4 impact reverse transcription but not nuclear translocation. DNAL1 and MAP4 knockdown cells do not display cytoskeletal defects. Together these experiments indicate that DNAL1 and MAP4 may exert their functions in the HIV life cycle at reverse transcription, prior to nuclear translocation.

  19. Knockdown of MAP4 and DNAL1 produces a post-fusion and pre-nuclear translocation impairment in HIV-1 replication.

    PubMed

    Gallo, Daniel E; Hope, Thomas J

    2012-01-05

    DNAL1 and MAP4 are both microtubule-associated proteins. These proteins were identified as HIV-1 dependency factors in a screen with wild-type HIV-1. In this study we demonstrate that knockdown using DNAL1 and MAP4 siRNAs and shRNAs inhibits HIV-1 infection regardless of envelope. Using a fusion assay, we show that DNAL1 and MAP4 do not impact fusion. By assaying for late reverse transcripts and 2-LTR circles, we show that DNAL1 and MAP4 inhibit both by approximately 50%. These results demonstrate that DNAL1 and MAP4 impact reverse transcription but not nuclear translocation. DNAL1 and MAP4 knockdown cells do not display cytoskeletal defects. Together these experiments indicate that DNAL1 and MAP4 may exert their functions in the HIV life cycle at reverse transcription, prior to nuclear translocation.

  20. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    NASA Astrophysics Data System (ADS)

    Smith, A.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility/ factorization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 x 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 x 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 x 4 = 2 x 2 x 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 x 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16, ... Could inter-digit Feshbach-resonances exist??? Possible applications to: quantum-information/ computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory "short-cut" method: Rayleigh(1870)-Polya(1922)-"Anderson"(1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics; ...abound!!! Watkins [www.secamlocal.ex.ac.uk/people/staff/mrwatkin/] "Number-Theory in Physics" many interconnections: "pure"-maths number-theory to physics including Siegel [AMS Joint Mtg.(2002)-Abs.# 973-60-124] inversion of statistics on-average digits' Newcomb(1881)-Weyl(14-16)-Benford(38)-law to reveal both the quantum and BEQS (digits = bosons = digits:"spinEless-boZos"). 1881 1885 1901 1905 1925 < 1927, altering quantum-theory history!!!

  1. Superconducting magnets for fusion applications

    SciTech Connect

    Henning, C.D.

    1987-07-02

    Fusion magnet technology has made spectacular advances in the past decade; to wit, the Mirror Fusion Test Facility and the Large Coil Project. However, further advances are still required for advanced economical fusion reactors. Higher fields to 14 T and radiation-hardened superconductors and insulators will be necessary. Coupled with high rates of nuclear heating and pulsed losses, the next-generation magnets will need still higher current density, better stability and quench protection. Cable-in-conduit conductors coupled with polyimide insulations and better steels seem to be the appropriate path. Neutron fluences up to 10/sup 19/ neutrons/cm/sup 2/ in niobium tin are achievable. In the future, other amorphous superconductors could raise these limits further to extend reactor life or decrease the neutron shielding and corresponding reactor size.

  2. Herpesvirus gB-induced fusion between the virion envelope and outer nuclear membrane during virus egress is regulated by the viral US3 kinase.

    PubMed

    Wisner, Todd W; Wright, Catherine C; Kato, Akihisa; Kawaguchi, Yasushi; Mou, Fan; Baines, Joel D; Roller, Richard J; Johnson, David C

    2009-04-01

    Herpesvirus capsids collect along the inner surface of the nuclear envelope and bud into the perinuclear space. Enveloped virions then fuse with the outer nuclear membrane (NM). We previously showed that herpes simplex virus (HSV) glycoproteins gB and gH act in a redundant fashion to promote fusion between the virion envelope and the outer NM. HSV mutants lacking both gB and gH accumulate enveloped virions in herniations, vesicles that bulge into the nucleoplasm. Earlier studies had shown that HSV mutants lacking the viral serine/threonine kinase US3 also accumulate herniations. Here, we demonstrate that HSV gB is phosphorylated in a US3-dependent manner in HSV-infected cells, especially in a crude nuclear fraction. Moreover, US3 directly phosphorylated the gB cytoplasmic (CT) domain in in vitro assays. Deletion of gB in the context of a US3-null virus did not add substantially to defects in nuclear egress. The majority of the US3-dependent phosphorylation of gB involved the CT domain and amino acid T887, a residue present in a motif similar to that recognized by US3 in other proteins. HSV recombinants lacking gH and expressing either gB substitution mutation T887A or a gB truncated at residue 886 displayed substantial defects in nuclear egress. We concluded that phosphorylation of the gB CT domain is important for gB-mediated fusion with the outer NM. This suggested a model in which the US3 kinase is incorporated into the tegument layer (between the capsid and envelope) in HSV virions present in the perinuclear space. By this packaging, US3 might be brought close to the gB CT tail, leading to phosphorylation and triggering fusion between the virion envelope and the outer NM.

  3. 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

  4. (Nuclear theory). [Research in nuclear physics

    SciTech Connect

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion. (LSP)

  5. 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)

  6. Fusion Materials Research at Oak Ridge National Laboratory in Fiscal Year 2014

    SciTech Connect

    Wiffen, Frederick W.; Noe, Susan P.; Snead, Lance Lewis

    2014-10-01

    The realization of fusion energy is a formidable challenge with significant achievements resulting from close integration of the plasma physics and applied technology disciplines. Presently, the most significant technological challenge for the near-term experiments such as ITER, and next generation fusion power systems, is the inability of current materials and components to withstand the harsh fusion nuclear environment. The overarching goal of the ORNL fusion materials program is to provide the applied materials science support and understanding to underpin the ongoing DOE Office of Science fusion energy program while developing materials for fusion power systems. In doing so the program continues to be integrated both with the larger U.S. and international fusion materials communities, and with the international fusion design and technology communities.

  7. Investigating the degree of "stigma" associated with nuclear energy technologies: A cross-cultural examination of the case of fusion power.

    PubMed

    Horlick-Jones, Tom; Prades, Ana; Espluga, Josep

    2012-07-01

    The extent to which nuclear energy technologies are, in some sense, "stigmatised" by historical environmental and military associations is of particular interest in contemporary debates about sustainable energy policy. Recent claims in the literature suggest that despite such stigmatisation, lay views on such technologies may be shifting towards a "reluctant acceptance," in the light of concerns about issues like anthropogenic climate change. In this paper, we report on research into learning and reasoning processes concerned with a largely unknown nuclear energy technology; namely fusion power. We focus on the role of the nuclear label, or "brand," in informing how lay citizens make sense of the nature of this technology. Our findings derive from a comparative analysis of data generated in Spain and Britain, using the same methodology.

  8. INTRODUCTION: Status report on fusion research

    NASA Astrophysics Data System (ADS)

    Burkart, Werner

    2005-10-01

    members' personal views on the latest achievements in fusion research, including magnetic and inertial confinement scenarios. The report describes fusion fundamentals and progress in fusion science and technology, with ITER as a possible partner in the realization of self-sustainable burning plasma. The importance of the socio-economic aspects of energy production using fusion power plants is also covered. Noting that applications of plasma science are of broad interest to the Member States, the report addresses the topic of plasma physics to assist in understanding the achievements of better coatings, cheaper light sources, improved heat-resistant materials and other high-technology materials. Nuclear fusion energy production is intrinsically safe, but for ITER the full range of hazards will need to be addressed, including minimising radiation exposure, to accomplish the goal of a sustainable and environmentally acceptable production of energy. We anticipate that the role of the Agency will in future evolve from supporting scientific projects and fostering information exchange to the preparation of safety principles and guidelines for the operation of burning fusion plasmas with a Q > 1. Technical progress in inertial and magnetic confinement, as well as in alternative concepts, will lead to a further increase in international cooperation. New means of communication will be needed, utilizing the best resources of modern information technology to advance interest in fusion. However, today the basis of scientific progress is still through journal publications and, with this in mind, we trust that this report will find an interested readership. We acknowledge with thanks the support of the members of the IFRC as an advisory body to the Agency. Seven chairmen have presided over the IFRC since its first meeting in 1971 in Madison, USA, ensuring that the IAEA fusion efforts were based on the best professional advice possible, and that information on fusion developments has

  9. Magneto-Inertial Fusion

    SciTech Connect

    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.; Betti, R.; Bauer, B. S.; Lindemuth, I. R.; Siemon, R. E.; Miller, R. L.; Laberge, M.; Delage, M.

    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.

  10. On the role of fusion neutron source with thorium blanket in forming the nuclide composition of the nuclear fuel cycle of the Russian Federation

    NASA Astrophysics Data System (ADS)

    Shmelev, A. N.; Kulikov, G. G.

    2016-12-01

    The possible role of available thorium resources of the Russian Federation in utilization of thorium in the closed (U-Pu)-fuel cycle of nuclear power is considered. The efficiency of application of fusion neutron sources with thorium blanket for economical use of available thorium resources is demonstrated. The objective of this study is the search for a solution of such major tasks of nuclear power as reduction of the amount of front-end operations in the nuclear fuel cycle and enhancement of its protection against uncontrolled proliferation of fissile materials with the smallest possible alterations in the fuel cycle. The earlier results are analyzed, new information on the amount of thorium resources of the Russian Federation is used, and additional estimates are made. The following basic results obtained on the basis of the assumption of involving fusion reactors with Th-blanket in future nuclear power for generation of the light uranium fraction 232+233+234U and 231Pa are formulated. (1) The fuel cycle would shift from fissile 235U to 233U, which is more attractive for thermal power reactors. (2) The light uranium fraction is the most "protected" in the uranium fuel component, and being mixed with regenerated uranium, it would become reduced-enrichment uranium fuel, which would relieve the problem of nonproliferation of the fissile material. (3) The addition of 231Pa into the fuel would stabilize its neutron-multiplying properties, thus making it possible to implement a long fuel residence time and, as a consequence, increase the export potential of the whole nuclear power technology. (4) The available thorium resource in the vicinity of Krasnoufimsk is sufficient for operation of the large-scale nuclear power industry of the Russian Federation with an electric power of 70 GW for more than one quarter of a century. The general conclusion is that involvement of a small number of fusion reactors with Th-blanket in the future nuclear power industry of the Russian

  11. Non-Gaussian fluctuations and non-Markovian effects in the nuclear fusion process: Langevin dynamics emerging from quantum molecular dynamics simulations.

    PubMed

    Wen, Kai; Sakata, Fumihiko; Li, Zhu-Xia; Wu, Xi-Zhen; Zhang, Ying-Xun; Zhou, Shan-Gui

    2013-07-05

    Macroscopic parameters as well as precise information on the random force characterizing the Langevin-type description of the nuclear fusion process around the Coulomb barrier are extracted from the microscopic dynamics of individual nucleons by exploiting the numerical simulation of the improved quantum molecular dynamics. It turns out that the dissipation dynamics of the relative motion between two fusing nuclei is caused by a non-Gaussian distribution of the random force. We find that the friction coefficient as well as the time correlation function of the random force takes particularly large values in a region a little bit inside of the Coulomb barrier. A clear non-Markovian effect is observed in the time correlation function of the random force. It is further shown that an emergent dynamics of the fusion process can be described by the generalized Langevin equation with memory effects by appropriately incorporating the microscopic information of individual nucleons through the random force and its time correlation function.

  12. Effect of the time interval between fusion and activation on epigenetic reprogramming and development of bovine somatic cell nuclear transfer embryos.

    PubMed

    Liu, Jun; Wang, Yongsheng; Su, Jianmin; Wang, Lijun; Li, Ruizhe; Li, Qian; Wu, Yongyan; Hua, Song; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2013-04-01

    Previous studies have shown that the time interval between fusion and activation (FA interval) play an important role in nuclear remodeling and in vitro development of somatic cell nuclear transfer (SCNT) embryos. However, the effects of FA interval on the epigenetic reprogramming and in vivo developmental competence of SCNT embryos remain unknown. In the present study, the effects of different FA intervals (0 h, 2 h, and 4 h) on the epigenetic reprogramming and developmental competence of bovine SCNT embryos were assessed. The results demonstrated that H3 lysine 9 (H3K9ac) levels decreased rapidly after fusion in all three groups. H3K9ac was practically undetectable 2 h after fusion in the 2-h and 4-h FA interval groups. However, H3K9ac was still evidently detectable in the 0-h FA interval group. The H3K9ac levels increased 10 h after fusion in all three groups, but were higher in the 2-h and 4-h FA interval groups than that in the 0-h FA interval group. The methylation levels of the satellite I region in day-7 blastocysts derived from the 2-h or 4-h FA interval groups was similar to that of in vitro fertilization blastocysts and is significantly lower than that of the 0-h FA interval group. SCNT embryos derived from 2-h FA interval group showed higher developmental competence than those from the 0-h and 4-h FA interval groups in terms of cleavage rate, blastocyst formation rate, apoptosis index, and pregnancy and calving rates. Hence, the FA interval is an important factor influencing the epigenetic reprogramming and developmental competence of bovine SCNT embryos.

  13. Experimental results on the irradiation of nuclear fusion relevant materials at the dense plasma focus ‘Bora’ device

    NASA Astrophysics Data System (ADS)

    Cicuttin, A.; Crespo, M. L.; Gribkov, V. A.; Niemela, J.; Tuniz, C.; Zanolli, C.; Chernyshova, M.; Demina, E. V.; Latyshev, S. V.; Pimenov, V. N.; Talab, A. A.

    2015-06-01

    Samples of materials counted as perspective ones for use in the first-wall and construction elements in nuclear fusion reactors (FRs) with magnetic and inertial plasma confinement (W, Ti, Al, low-activated ferritic steel ‘Eurofer’ and some alloys) were irradiated in the dense plasma focus (DPF) device ‘Bora’ having a bank energy of ⩽5 kJ. The device generates hot dense (T ˜ 1 keV, n ˜ 1019 cm-3) deuterium plasma, powerful plasma streams (v ˜ 3 × 107 cm s-1) and fast (E ˜ 0.1 … 1.0 MeV) deuterons of power flux densities q up to 1010 and 1012 W cm-2 correspondingly. ‘Damage factor’ F = q × τ0.5 ensures an opportunity to simulate radiation loads (predictable for both reactors types) by the plasma/ion streams, which have the same nature and namely those parameters as expected in the FR modules. Before and after irradiation we provided investigations of our samples by means of a number of analytical techniques. Among them we used optical and scanning electron microscopy to understand character and parameters of damageability of the surface layers of the samples. Atomic force microscopy was applied to measure roughness of the surface after irradiation. These characteristics are quite important for understanding mechanisms and values of dust production in FR that may relate to tritium retention and emergency situations in FR facilities. We also applied two new techniques. For the surface we elaborated the portable x-ray diffractometer that combines x-ray single photon detection with high spectroscopic and angular resolutions. For bulk damageability investigations we applied an x-ray microCT system where x-rays were produced by a Hamamatsu microfocus source (150 kV, 500 µA, 5 µm minimum focal spot size). The detector was a Hamamatsu CMOS flat panel coupled to a fibre optic plate under the GOS scintillator. The reconstruction of three-dimensional data was run with Cobra 7.4 and DIGIX CT software while VG Studio Max 2.1, and Amira 5.3 were used for

  14. The nuclear option

    SciTech Connect

    Herken, G.

    1992-03-01

    A development history and current status evaluation are presented for nuclear-thermal rocket propulsion systems applicable to interplanetary flight. While the most advanced current chemical rocket engines, such as the SSMEs of the Space Shuttle, produce specific impulses of the order of 450 secs, a nuclear-thermal rocket engine tested at Los Alamos in 1969 generated 845 secs; such specific impulse improvements could represent weeks or months of interplanetary travel time. Attention is given to the achievements of the historical Nuclear Engine for Rocket Vehicle Application, Helios, and Orion design programs, as well as to the current Vehicle for Interplanetary Space Transportation Applications, which is fusion-based.

  15. Fusion body formation, germ tube anastomosis, and nuclear migration during the germination of urediniospores of the wheat leaf rust fungus, Puccinia triticina.

    PubMed

    Wang, Xiben; McCallum, Brent

    2009-12-01

    ABSTRACT Vegetative or parasexual recombination is thought to be a key mechanism for the genetic diversity of cereal rust fungi. The process of germ tube fusion leading to hyphal anastomosis and nuclear recombination was analyzed in wheat leaf rust fungus, Puccinia triticina. Germ tube anastomosis was observed in 27 P. triticina isolates, each representing a different virulence phenotype. Germ tube fusion bodies (GFBs), which appeared as viscid globules formed at tips of germ tubes, were essential for germ tube anastomosis. The formation of GFBs was affected by the urediniospore density and the length of illumination during germination. GFBs were formed at the highest frequency when urediniospores were spread to a concentration of 1 x 10(6) urediniospores/ml and incubated in dark for 12 to 24 h during germination. GFB attached to either the side of another germ tube ("tip to side") or to another GFB formed at the tip of a second germ tube ("tip to tip"). In "tip to side" anastomosis, two nuclei in the germ tube bearing the GFB migrated into the second germ tube through the GFB which resulted in four nuclei within this germ tube. In "tip to tip" anastomosis, nuclei in both germ tubes migrated into the fused GFB and all four nuclei came into close proximity. Urediniospores of isolates MBDS-3-115 and TBBJ-5-11 were stained with DAPI (4',6'diamine-2-phenylindole) and Nuclear Yellow (Hoechst S769121), respectively, and then mixed and germinated on water agar. Some fused GFBs contained nuclei stained with DAPI and nuclei stained with Nuclear Yellow in close proximity, demonstrating the fusion between genetically different P. triticina isolates. In some fused GFBs, "bridge-like" structures connecting different nuclei were observed.

  16. Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion.

    PubMed

    Tanabe, Katsuaki

    2016-01-01

    We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

  17. A TUTORIAL ON IGNITION AND GAIN FOR SMALL FUSION TARGETS

    SciTech Connect

    Kirkpatrick, R. C.

    2009-07-26

    Nuclear fusion was discovered experimentally in 1933-34 and other charged particle nuclear reactions were documented shortly thereafter. 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 (rhoR), 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.

  18. Role of nuclear dissipation and entrance channel mass asymmetry in pre-scission neutron multiplicity enhancement in fusion-fission reactions

    SciTech Connect

    Singh, Hardev; Sandal, Rohit; Behera, Bivash R.; Singh, Gulzar; Govil, I. M.; Golda, K. S.; Ranjeet,; Jhingan, Akhil; Singh, R. P.; Sugathan, P.; Chatterjee, M. B.; Datta, S. K.; Pal, Santanu; Viesti, G.

    2008-08-15

    Pre-scission neutron multiplicities are measured for {sup 12}C + {sup 204}Pb and {sup 19}F + {sup 197}Au reactions at laboratory energies of 75-95 MeV for the {sup 12}C beam and 98-118 MeV for the {sup 19}F beam. The chosen projectile-target combinations in the present study lie on either side of the Businaro-Gallone mass asymmetry ({alpha}{sub BG}) and populate the {sup 216}Ra compound nucleus. The dissipation strength is deduced after comparing the experimentally measured neutron yield with the statistical model predictions which contains the nuclear viscosity as a free parameter. Present results demonstrate the combined effects of entrance channel mass asymmetry and the dissipative property of nuclear matter on the pre-scission neutron multiplicity in fusion-fission reactions.

  19. Establishment of an Institute for Fusion Studies

    SciTech Connect

    Hazeltine, R.D.

    1992-07-01

    The Institute for Fusion Studies is a national center for theoretical fusion plasma physics research. Its purposes are: (1) to conduct research on theoretical questions concerning the achievement of controlled fusion energy by means of magnetic confinement--including both fundamental problems of long-range significance, as well as shorter-term issues; (2) to serve as a center for information exchange, nationally and internationally, by hosting exchange visits, conferences, and workshops; (3) and to train students and postdoctoral research personnel for the fusion energy program and plasma physics research areas. The theoretical research results that are obtained by the Institute contribute mainly to the progress of national and international efforts in nuclear fusion research, whose goal is the development of fusion power.as a basic energy source. In addition to its primary focus on fusion physics, the Institute is also involved with research in related fields, such as advanced computing techniques, nonlinear dynamics, plasma astrophysics, and accelerator physics. The work of EFS scientists continued to receive national and international recognition. Numerous invited papers were given during the past year at workshops, conferences, and scientific meetings. Last year IFS scientists published 95 scientific articles in technical journals and monographs.

  20. Engineering Challenges in Antiproton Triggered Fusion Propulsion

    SciTech Connect

    Cassenti, Brice; Kammash, Terry

    2008-01-21

    During the last decade antiproton triggered fusion propulsion has been investigated as a method for achieving high specific impulse, high thrust in a nuclear pulse propulsion system. In general the antiprotons are injected into a pellet containing fusion fuel with a small amount of fissionable material (i.e., an amount less than the critical mass) where the products from the fission are then used to trigger a fusion reaction. Initial calculations and simulations indicate that if magnetically insulated inertial confinement fusion is used that the pellets should result in a specific impulse of between 100,000 and 300,000 seconds at high thrust. The engineering challenges associated with this propulsion system are significant. For example, the antiprotons must be precisely focused. The pellet must be designed to contain the fission and initial fusion products and this will require strong magnetic fields. The fusion fuel must be contained for a sufficiently long time to effectively release the fusion energy, and the payload must be shielded from the radiation, especially the excess neutrons emitted, in addition to many other particles. We will review the recent progress, possible engineering solutions and the potential performance of these systems.

  1. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+{sup 11}B process

    SciTech Connect

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-15

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+{sup 11}B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from {sup 11}B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+{sup 11}B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+{sup 11}B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+{sup 11}B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  2. LIFE: The Case for Early Commercialization of Fusion Energy

    SciTech Connect

    Anklam, T; Simon, A J; Powers, S; Meier, W R

    2010-11-30

    This paper presents the case for early commercialization of laser inertial fusion energy (LIFE). Results taken from systems modeling of the US electrical generating enterprise quantify the benefits of fusion energy in terms of carbon emission, nuclear waste and plutonium production avoidance. Sensitivity of benefits-gained to timing of market-entry is presented. These results show the importance of achieving market entry in the 2030 time frame. Economic modeling results show that fusion energy can be competitive with other low-carbon energy sources. The paper concludes with a description of the LIFE commercialization path. It proposes constructing a demonstration facility capable of continuous fusion operations within 10 to 15 years. This facility will qualify the processes and materials needed for a commercial fusion power plant.

  3. Telomere elongation and naive pluripotent stem cells achieved from telomerase haplo-insufficient cells by somatic cell nuclear transfer.

    PubMed

    Sung, Li-Ying; Chang, Wei-Fang; Zhang, Qian; Liu, Chia-Chia; Liou, Jun-Yang; Chang, Chia-Chun; Ou-Yang, Huan; Guo, Renpeng; Fu, Haifeng; Cheng, Winston T K; Ding, Shih-Torng; Chen, Chuan-Mu; Okuka, Maja; Keefe, David L; Chen, Y Eugene; Liu, Lin; Xu, Jie

    2014-12-11

    Haplo-insufficiency of telomerase genes in humans leads to telomere syndromes such as dyskeratosis congenital and idiopathic pulmonary fibrosis. Generation of pluripotent stem cells from telomerase haplo-insufficient donor cells would provide unique opportunities toward the realization of patient-specific stem cell therapies. Recently, pluripotent human embryonic stem cells (ntESCs) have been efficiently achieved by somatic cell nuclear transfer (SCNT). We tested the hypothesis that SCNT could effectively elongate shortening telomeres of telomerase haplo-insufficient cells in the ntESCs with relevant mouse models. Indeed, telomeres of telomerase haplo-insufficient (Terc(+/-)) mouse cells are elongated in ntESCs. Moreover, ntESCs derived from Terc(+/-) cells exhibit naive pluripotency as evidenced by generation of Terc(+/-) ntESC clone pups by tetraploid embryo complementation, the most stringent test of naive pluripotency. These data suggest that SCNT could offer a powerful tool to reprogram telomeres and to discover the factors for robust restoration of telomeres and pluripotency of telomerase haplo-insufficient somatic cells.

  4. Effects of recipient oocyte age and interval from fusion to activation on development of buffalo (Bubalus bubalis) nuclear transfer embryos derived from fetal fibroblasts.

    PubMed

    Lu, F; Jiang, J; Li, N; Zhang, S; Sun, H; Luo, C; Wei, Y; Shi, D

    2011-09-15

    The objective was to investigate the effect of recipient oocyte age and the interval from activation to fusion on developmental competence of buffalo nuclear transfer (NT) embryos. Buffalo oocytes matured in vitro for 22 h were enucleated by micromanipulation under the spindle view system, and a fetal fibroblast (pretreated with 0.1 μg/mL aphidicolin for 24 h, followed by culture for 48 h in 0.5% fetal bovine serum) was introduced into the enucleated oocyte, followed by electrofusion. Both oocytes and NT embryos were activated by exposure to 5 μM ionomycin for 5 min, followed by culture in 2 mM 6-dimethyl-aminopurine for 3 h. When oocytes matured in vitro for 28, 29, 30, 31, or 32 h were activated, more oocytes matured in vitro for 30 h developed into blastocysts in comparison with oocytes matured in vitro for 32 h (31.3 vs 19.9%, P < 0.05). When electrofusion was induced 27 h after the onset of oocyte maturation, the cleavage rate (78.0%) was higher than that of electrofusion induced at 28 h (67.2%, P < 0.05), and the blastocyst yield (18.1%) was higher (P < 0.05) than that of electrofusion induced at 25 or 26 h (7.4 and 8.5%, respectively). A higher proportion of NT embryos activated at 3 h after electrofusion developed to the blastocyst stage (18.6%) in comparison with NT embryos activated at 1 h (6.0%), 2 h (8.3%), or 4 h (10.6%) after fusion (P < 0.05). No recipient was pregnant 60 d after transfer of blastocysts developed from NT embryos activated at 1 h (0/8), 2 h (0/10), or 4 h (0/9) after fusion. However, 3 of 16 recipients were pregnant following transfer of blastocysts developed from the NT embryos activated at 3 h after fusion, and two of these recipients maintained pregnancy to term. We concluded that the developmental potential of buffalo NT embryos was related to recipient oocyte age and the interval from fusion to activation.

  5. Muon Catalyzed Fusion

    NASA Technical Reports Server (NTRS)

    Armour, Edward A.G.

    2007-01-01

    Muon catalyzed fusion is a process in which a negatively charged muon combines with two nuclei of isotopes of hydrogen, e.g, a proton and a deuteron or a deuteron and a triton, to form a muonic molecular ion in which the binding is so tight that nuclear fusion occurs. The muon is normally released after fusion has taken place and so can catalyze further fusions. As the muon has a mean lifetime of 2.2 microseconds, this is the maximum period over which a muon can participate in this process. This article gives an outline of the history of muon catalyzed fusion from 1947, when it was first realised that such a process might occur, to the present day. It includes a description of the contribution that Drachrnan has made to the theory of muon catalyzed fusion and the influence this has had on the author's research.

  6. 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

  7. 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

  8. 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.

  9. The Use of Two-Photon FRET-FLIM to Study Protein Interactions During Nuclear Envelope Fusion In Vivo and In Vitro.

    PubMed

    Byrne, Richard D; Larijani, Banafshé; Poccia, Dominic L

    2016-01-01

    FRET-FLIM techniques have wide application in the study of protein and protein-lipid interactions in cells. We have pioneered an imaging platform for accurate detection of functional states of proteins and their interactions in fixed cells. This platform, two-site-amplified Förster resonance energy transfer (a-FRET), allows greater signal generation while retaining minimal noise thus enabling application of fluorescence lifetime imaging microscopy (FLIM) to be routinely deployed in different types of cells and tissue. We have used the method described here, time-resolved FRET monitored by two-photon FLIM, to demonstrate the direct interaction of Phospholipase Cγ (PLCγ) by Src Family Kinase 1 (SFK1) during nuclear envelope formation and during male and female pronuclear membrane fusion in fertilized sea urchin eggs. We describe here a generic method that can be applied to monitor any proteins of interest.

  10. Tri-membrane nanoparticles produced by combining liposome fusion and a novel patchwork of bicelles to overcome endosomal and nuclear membrane barriers to cargo delivery.

    PubMed

    Yamada, Asako; Mitsueda, Asako; Hasan, Mahadi; Ueda, Miho; Hama, Susumu; Warashina, Shota; Nakamura, Takashi; Harashima, Hideyoshi; Kogure, Kentaro

    2016-03-01

    Membrane fusion is a rational strategy for crossing intracellular membranes that present barriers to liposomal nanocarrier-mediated delivery of plasmid DNA into the nucleus of non-dividing cells, such as dendritic cells. Based on this strategy, we previously developed nanocarriers consisting of a nucleic acid core particle coated with four lipid membranes [Akita, et al., Biomaterials, 2009, 30, 2940-2949]. However, including the endosomal membrane and two nuclear membranes, cells possess three intracellular membranous barriers. Thus, after entering the nucleus, nanoparticles coated with four membranes would still have one lipid membrane remaining, and could impede cargo delivery. Until now, coating a core particle with an odd number of lipid membranes was challenging. To produce nanocarriers with an odd number of lipid membranes, we developed a novel coating method involving lipid nano-discs, also known as bicelles, as a material for packaging DNA in a carrier with an odd number of lipid membranes. In this procedure, bicelles fuse to form an outer coating that resembles a patchwork quilt, which allows the preparation of nanoparticles coated with only three lipid membranes. Moreover, the transfection activity of dendritic cells with these three-membrane nanoparticles was higher than that for nanoparticles coated with four lipid membranes. In summary, we developed novel nanoparticles coated with an odd number of lipid membranes using the novel "patchwork-packaging method" to deliver plasmid DNA into the nucleus via membrane fusion.

  11. Image computing techniques to extrapolate data for dust tracking in case of an experimental accident simulation in a nuclear fusion plant

    NASA Astrophysics Data System (ADS)

    Camplani, M.; Malizia, A.; Gelfusa, M.; Barbato, F.; Antonelli, L.; Poggi, L. A.; Ciparisse, J. F.; Salgado, L.; Richetta, M.; Gaudio, P.

    2016-01-01

    In this paper, a preliminary shadowgraph-based analysis of dust particles re-suspension due to loss of vacuum accident (LOVA) in ITER-like nuclear fusion reactors has been presented. Dust particles are produced through different mechanisms in nuclear fusion devices, one of the main issues is that dust particles are capable of being re-suspended in case of events such as LOVA. Shadowgraph is based on an expanded collimated beam of light emitted by a laser or a lamp that emits light transversely compared to the flow field direction. In the STARDUST facility, the dust moves in the flow, and it causes variations of refractive index that can be detected by using a CCD camera. The STARDUST fast camera setup allows to detect and to track dust particles moving in the vessel and then to obtain information about the velocity field of dust mobilized. In particular, the acquired images are processed such that per each frame the moving dust particles are detected by applying a background subtraction technique based on the mixture of Gaussian algorithm. The obtained foreground masks are eventually filtered with morphological operations. Finally, a multi-object tracking algorithm is used to track the detected particles along the experiment. For each particle, a Kalman filter-based tracker is applied; the particles dynamic is described by taking into account position, velocity, and acceleration as state variable. The results demonstrate that it is possible to obtain dust particles' velocity field during LOVA by automatically processing the data obtained with the shadowgraph approach.

  12. Image computing techniques to extrapolate data for dust tracking in case of an experimental accident simulation in a nuclear fusion plant

    SciTech Connect

    Camplani, M.; Malizia, A.; Gelfusa, M.; Poggi, L. A.; Ciparisse, J. F.; Richetta, M.; Gaudio, P.; Barbato, F.; Antonelli, L.; Salgado, L.

    2016-01-15

    In this paper, a preliminary shadowgraph-based analysis of dust particles re-suspension due to loss of vacuum accident (LOVA) in ITER-like nuclear fusion reactors has been presented. Dust particles are produced through different mechanisms in nuclear fusion devices, one of the main issues is that dust particles are capable of being re-suspended in case of events such as LOVA. Shadowgraph is based on an expanded collimated beam of light emitted by a laser or a lamp that emits light transversely compared to the flow field direction. In the STARDUST facility, the dust moves in the flow, and it causes variations of refractive index that can be detected by using a CCD camera. The STARDUST fast camera setup allows to detect and to track dust particles moving in the vessel and then to obtain information about the velocity field of dust mobilized. In particular, the acquired images are processed such that per each frame the moving dust particles are detected by applying a background subtraction technique based on the mixture of Gaussian algorithm. The obtained foreground masks are eventually filtered with morphological operations. Finally, a multi-object tracking algorithm is used to track the detected particles along the experiment. For each particle, a Kalman filter-based tracker is applied; the particles dynamic is described by taking into account position, velocity, and acceleration as state variable. The results demonstrate that it is possible to obtain dust particles’ velocity field during LOVA by automatically processing the data obtained with the shadowgraph approach.

  13. Image computing techniques to extrapolate data for dust tracking in case of an experimental accident simulation in a nuclear fusion plant.

    PubMed

    Camplani, M; Malizia, A; Gelfusa, M; Barbato, F; Antonelli, L; Poggi, L A; Ciparisse, J F; Salgado, L; Richetta, M; Gaudio, P

    2016-01-01

    In this paper, a preliminary shadowgraph-based analysis of dust particles re-suspension due to loss of vacuum accident (LOVA) in ITER-like nuclear fusion reactors has been presented. Dust particles are produced through different mechanisms in nuclear fusion devices, one of the main issues is that dust particles are capable of being re-suspended in case of events such as LOVA. Shadowgraph is based on an expanded collimated beam of light emitted by a laser or a lamp that emits light transversely compared to the flow field direction. In the STARDUST facility, the dust moves in the flow, and it causes variations of refractive index that can be detected by using a CCD camera. The STARDUST fast camera setup allows to detect and to track dust particles moving in the vessel and then to obtain information about the velocity field of dust mobilized. In particular, the acquired images are processed such that per each frame the moving dust particles are detected by applying a background subtraction technique based on the mixture of Gaussian algorithm. The obtained foreground masks are eventually filtered with morphological operations. Finally, a multi-object tracking algorithm is used to track the detected particles along the experiment. For each particle, a Kalman filter-based tracker is applied; the particles dynamic is described by taking into account position, velocity, and acceleration as state variable. The results demonstrate that it is possible to obtain dust particles' velocity field during LOVA by automatically processing the data obtained with the shadowgraph approach.

  14. 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;…

  15. Advanced Concepts: Aneutronic Fusion Power and Propulsion

    NASA Technical Reports Server (NTRS)

    Chapman, John J.

    2012-01-01

    Aneutronic Fusion for In-Space thrust, power. Clean energy & potential nuclear gains. Fusion plant concepts, potential to use advanced fuels. Methods to harness ionic momentum for high Isp thrust plus direct power conversion into electricity will be presented.

  16. Fusion technology development. Annual report, October 1, 1994--September 30, 1995

    SciTech Connect

    1996-08-01

    In FY95, the General Atomics (GA) Fusion Group made significant contributions to the technology needs of the magnetic fusion program. The work is reported in the following sections on Fusion Power Plant Studies (Section 2), DiMES (Section 3), SiC Composite Studies (Section 4), Magnetic Probe (Section 5) and RF Technology (Section 6). Meetings attended and publications are listed in their respective sections. The overall objective of GA`s fusion technology research is to develop the technologies necessary for fusion to move successfully from present-day physics experiments to ITER and other next-generation fusion experiments, and ultimately to fusion power plants. To achieve this overall objective, they carry out fusion systems design studies to evaluate the technologies needed for next-step experiments and power plants, and they conduct research to develop basic knowledge about these technologies, including plasma technologies, fusion nuclear technologies, and fusion materials. They continue to be committed to the development of fusion power and its commercialization by US industry.

  17. Fusion technology development annual report, October 1, 1995--September 30, 1996

    SciTech Connect

    1997-03-01

    In FY96, the General Atomics (GA) Fusion Group made significant contributions to the technology needs of the magnetic fusion program. The work is reported in the following sections on Fusion Power Plant Design Studies (Section 2), Plasma Interactive Materials (Section 3), SiC/SiC Composite Material Development (Section 4), Magnetic Diagnostic Probes (Section 5) and RF Technology (Section 6). Meetings attended and publications are listed in their respective sections. The overall objective of GA`s fusion technology research is to develop the technologies necessary for fusion to move successfully from present-day physics experiments to ITER and other next-generation fusion experiments, and ultimately to fusion power plants. To achieve this overall objective, the authors carry out fusion systems design studies to evaluate the technologies needed for next-step experiments and power plants, and they conduct research to develop basic knowledge about these technologies, including plasma technologies, fusion nuclear technologies, and fusion materials. They continue to be committed to the development of fusion power and its commercialization by US industry.

  18. Commercial objectives, technology transfer, and systems analysis for fusion power development

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    1988-03-01

    Fusion is an essentially inexhaustible source of energy that has the potential for economically attractive commercial applications with excellent safety and environmental characteristics. The primary focus for the fusion-energy development program is the generation of centralstation electricity. Fusion has the potential, however, for many other applications. The fact that a large fraction of the energy released in a DT fusion reaction is carried by high-energy neutrons suggests potentially unique applications. These include breeding of fissile fuels, production of hydrogen and other chemical products, transmutation or “burning” of various nuclear or chemical wastes, radiation processing of materials, production of radioisotopes, food preservation, medical diagnosis and medical treatment, and space power and space propulsion. In addition, fusion R&D will lead to new products and new markets. Each fusion application must meet certain standards of economic and safety and environmental attractiveness. For this reason, economics on the one hand, and safety and environment and licensing on the other hand, are the two primary criteria for setting long-range commercial fusion objectives. A major function of systems analysis is to evaluate the potential of fusion against these objectives and to help guide the fusion R&D program toward practical applications. The transfer of fusion technology and skills from the national laboratories and universities to industry is the key to achieving the long-range objective of commercial fusion applications.

  19. Fusion safety regulations in the United States: Progress and trends

    SciTech Connect

    DeLooper, J.

    1994-07-01

    This paper explores the issue of regulations as they apply to current and future fusion experimental machines. It addresses fusion regulatory issues, current regulations used for fusion, the Tokamak Fusion Test Reactor experience with regulations, and future regulations to achieve fusion`s safety and environmental potential.

  20. Z-Pinch Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Miernik, Janie

    2011-01-01

    Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Shorter trips are better for humans in the harmful radiation environment of deep space. Nuclear propulsion and power plants can enable high Ispand payload mass fractions because they require less fuel mass. Fusion energy research has characterized the Z-Pinch dense plasma focus method. (1) Lightning is form of pinched plasma electrical discharge phenomena. (2) Wire array Z-Pinch experiments are commonly studied and nuclear power plant configurations have been proposed. (3) Used in the field of Nuclear Weapons Effects (NWE) testing in the defense industry, nuclear weapon x-rays are simulated through Z-Pinch phenomena.

  1. Cold fusion verification

    NASA Astrophysics Data System (ADS)

    North, M. H.; Mastny, G. F.; Wesley, E. J.

    1991-03-01

    The objective of this work to verify and reproduce experimental observations of Cold Nuclear Fusion (CNF), as originally reported in 1989. The method was to start with the original report and add such additional information as became available to build a set of operational electrolytic CNF cells. Verification was to be achieved by first observing cells for neutron production, and for those cells that demonstrated a nuclear effect, careful calorimetric measurements were planned. The authors concluded, after laboratory experience, reading published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater. The neutron detector used for these tests was a completely packaged unit built into a metal suitcase that afforded electrostatic shielding for the detectors and self-contained electronics. It was battery-powered, although it was on charge for most of the long tests. The sensor element consists of He detectors arranged in three independent layers in a solid moderating block. The count from each of the three layers as well as the sum of all the detectors were brought out and recorded separately. The neutron measurements were made with both the neutron detector and the sample tested in a cave made of thick moderating material that surrounded the two units on the sides and bottom.

  2. Differential transactivation by orphan nuclear receptor NOR1 and its fusion gene product EWS/NOR1: possible involvement of poly(ADP-ribose) polymerase I, PARP-1.

    PubMed

    Ohkura, Naganari; Nagamura, Yuko; Tsukada, Toshihiko

    2008-10-15

    In extraskeletal myxoid chondrosarcoma, a chromosomal translocation creates a gene fusion between EWS and an orphan nuclear receptor, NOR1. The resulting fusion protein EWS/NOR1 has been believed to lead to malignant transformation by functioning as a transactivator for NOR1-target genes. By comparing the gene expression profiles of NOR1- and EWS/NOR1-overexpressing cells, we found that they largely shared up-regulated genes, but no significant correlation was observed with respect to the transactivation levels of each gene. In addition, the proteins associated with NOR1 and EWS/NOR1 were mostly the same in these cells. The results suggest that these proteins differentially transactivate overlapping target genes through a similar transcriptional machinery. To clarify the mechanisms underlying the transcriptional divergence between NOR1 and EWS/NOR1, we searched for alternatively associated proteins, and identified poly(ADP-ribose) polymerase I (PARP-1) as an NOR1-specific binding protein. Consistent with its binding properties, PARP-1 acted as a transcriptional repressor of NOR1, but not EWS/NOR1, in a luciferase reporter assay employing PARP-1(-/-) fibroblasts. Interestingly, suppressive activity of PARP-1 was observed in a DNA response element-specific manner, and in a subtype-specific manner toward the NR4A family (Nur77, Nurr1, and NOR1), suggesting that PARP-1 plays a role in the diversity of transcriptional regulation mediated by the NR4A family in normal cells. Altogether, our findings suggest that NOR1 and EWS/NOR1 regulate overlapping target genes differently by utilizing associated proteins, including PARP-1; and that EWS/NOR1 may acquire oncogenic activities by avoiding (or gaining) transcription factor-specific modulation by the associated proteins.

  3. Prospects for bubble fusion

    SciTech Connect

    Nigmatulin, R.I.; Lahey, R.T. Jr.

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  4. Effects of nuclear orientation on fusion and fission process for reactions using {sup 238}U target nucleus

    SciTech Connect

    Nishio, K.; Ikezoe, H.; Mitsuoka, S.; Nishinaka, I.; Makii, H.; Nagame, Y.; Watanabe, Y.; Ohtsuki, T.; Hirose, K.; Hofmann, S.

    2010-06-01

    Fission fragment mass distributions in the reaction of {sup 30}Si+{sup 238}U were measured at the energies around the Coulomb barrier. At the above-barrier energies, the mass distribution showed Gaussian shape. At the sub-barrier energies, asymmetric fission mode peaked at A{sub L}/A{sub H}approx =90/178 was observed. The asymmetric fission should be attributed to quasifission from the results of the measured evaporation residue (ER) cross-sections produced by {sup 30}Si+{sup 238}U. The cross-section for {sup 263}Sg at the above-barrier energy agree with the statistical model calculation which assumes that the measured fission cross-sections are equal to the fusion cross-sections, whereas the one for {sup 264}Sg measured at the sub-barrier energy is smaller than the calculation, indicating the presence for quasifission. The fragment mass distributions are compared to those for {sup 36}S+{sup 238}U and {sup 40}Ar+{sup 238}U.

  5. Development of design technique for vacuum insulation in large size multi-aperture multi-grid accelerator for nuclear fusion

    SciTech Connect

    Kojima, A. Hanada, M.; Tobari, H.; Nishikiori, R.; Hiratsuka, J.; Kashiwagi, M.; Umeda, N.; Yoshida, M.; Ichikawa, M.; Watanabe, K.; Yamano, Y.; Grisham, L. R.

    2016-02-15

    Design techniques for the vacuum insulation have been developed in order to realize a reliable voltage holding capability of multi-aperture multi-grid (MAMuG) accelerators for fusion application. In this method, the nested multi-stage configuration of the MAMuG accelerator can be uniquely designed to satisfy the target voltage within given boundary conditions. The evaluation of the voltage holding capabilities of each acceleration stages was based on the previous experimental results about the area effect and the multi-aperture effect. Since the multi-grid effect was found to be the extension of the area effect by the total facing area this time, the total voltage holding capability of the multi-stage can be estimated from that per single stage by assuming the stage with the highest electric field, the total facing area, and the total apertures. By applying these consideration, the analysis on the 3-stage MAMuG accelerator for JT-60SA agreed well with the past gap-scan experiments with an accuracy of less than 10% variation, which demonstrated the high reliability to design MAMuG accelerators and also multi-stage high voltage bushings.

  6. Immunogenicity of nuclear-encoded LTB:ST fusion protein from Escherichia coli expressed in tobacco plants.

    PubMed

    Rosales-Mendoza, Sergio; Soria-Guerra, Ruth E; Moreno-Fierros, Leticia; Govea-Alonso, Dania O; Herrera-Díaz, Areli; Korban, Schuyler S; Alpuche-Solís, Ángel G

    2011-06-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the main causative agents of diarrhea in infants and for travelers. Inclusion of a heat-stable (ST) toxin into vaccine formulations is mandatory as most ETEC strains can produce both heat-labile (LT) and ST enterotoxins. In this study, a genetic fusion gene encoding for an LTB:ST protein has been constructed and transferred into tobacco via Agrobacterium tumefaciens-mediated transformation. Transgenic tobacco plants carrying the LTB:ST gene are then subjected to GM1-ELISA revealing that the LTB:ST has assembled into pentamers and displays antigenic determinants from both LTB and ST. Protein accumulation of up to 0.05% total soluble protein is detected. Subsequently, mucosal and systemic humoral responses are elicited in mice orally dosed with transgenic tobacco leaves. This has suggested that the plant-derived LTB:ST is immunogenic via the oral route. These findings are critical for the development of a plant-based vaccine capable of eliciting broader protection against ETEC and targeting both LTB and ST. Features of this platform in comparison to transplastomic approaches are discussed.

  7. Development of design technique for vacuum insulation in large size multi-aperture multi-grid accelerator for nuclear fusion.

    PubMed

    Kojima, A; Hanada, M; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    Design techniques for the vacuum insulation have been developed in order to realize a reliable voltage holding capability of multi-aperture multi-grid (MAMuG) accelerators for fusion application. In this method, the nested multi-stage configuration of the MAMuG accelerator can be uniquely designed to satisfy the target voltage within given boundary conditions. The evaluation of the voltage holding capabilities of each acceleration stages was based on the previous experimental results about the area effect and the multi-aperture effect. Since the multi-grid effect was found to be the extension of the area effect by the total facing area this time, the total voltage holding capability of the multi-stage can be estimated from that per single stage by assuming the stage with the highest electric field, the total facing area, and the total apertures. By applying these consideration, the analysis on the 3-stage MAMuG accelerator for JT-60SA agreed well with the past gap-scan experiments with an accuracy of less than 10% variation, which demonstrated the high reliability to design MAMuG accelerators and also multi-stage high voltage bushings.

  8. The role of nuclear reactions and {alpha}-particle transport in the dynamics of inertial confinement fusion capsules

    SciTech Connect

    Garnier, Josselin; Cherfils-Clerouin, Catherine

    2008-10-15

    This paper is devoted to the study of the deceleration phase of inertial confinement capsules. The purpose is to obtain a zero-dimensional model that has the form of a closed system of ordinary differential equations for the main hydrodynamic quantities. The model takes into account the energy released by nuclear reactions, a nonlocal model for the {alpha}-particle energy deposition process, and radiation loss by electron bremsstrahlung. The asymptotic analysis is performed in the case of a strong temperature dependence of the thermal conductivity. We finally study the beginning of the expansion phase after stagnation to derive an ignition criterion.

  9. Fusion Materials Research at Oak Ridge National Laboratory in Fiscal Year 2015

    SciTech Connect

    Wiffen, F. W.; Katoh, Yutai; Melton, Stephanie G.

    2015-12-01

    The realization of fusion energy is a formidable challenge with significant achievements resulting from close integration of the plasma physics and applied technology disciplines. Presently, the most significant technological challenge for the near-term experiments such as ITER, and next generation fusion power systems, is the inability of current materials and components to withstand the harsh fusion nuclear environment. The overarching goal of the Oak Ridge National Laboratory (ORNL) fusion materials program is to provide the applied materials science support and understanding to underpin the ongoing Department of Energy (DOE) Office of Science fusion energy program while developing materials for fusion power systems. In doing so the program continues to be integrated both with the larger United States (US) and international fusion materials communities, and with the international fusion design and technology communities.This document provides a summary of Fiscal Year (FY) 2015 activities supporting the Office of Science, Office of Fusion Energy Sciences Materials Research for Magnetic Fusion Energy (AT-60-20-10-0) carried out by ORNL. The organization of this report is mainly by material type, with sections on specific technical activities. Four projects selected in the Funding Opportunity Announcement (FOA) solicitation of late 2011 and funded in FY2012-FY2014 are identified by “FOA” in the titles. This report includes the final funded work of these projects, although ORNL plans to continue some of this work within the base program.

  10. Hybrid-view programming of nuclear fusion simulation code in the PGAS parallel programming language XcalableMP

    SciTech Connect

    Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi; Sato, Mitsuhisa; Tang, William; Wang, Bei

    2016-06-01

    Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensional gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.

  11. Hybrid-view programming of nuclear fusion simulation code in the PGAS parallel programming language XcalableMP

    DOE PAGES

    Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi; ...

    2016-06-01

    Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensionalmore » gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.« less

  12. Segmentation of biological target volumes on multi-tracer PET images based on information fusion for achieving dose painting in radiotherapy.

    PubMed

    Lelandais, Benoît; Gardin, Isabelle; Mouchard, Laurent; Vera, Pierre; Ruan, Su

    2012-01-01

    Medical imaging plays an important role in radiotherapy. Dose painting consists in the application of a nonuniform dose prescription on a tumoral region, and is based on an efficient segmentation of biological target volumes (BTV). It is derived from PET images, that highlight tumoral regions of enhanced glucose metabolism (FDG), cell proliferation (FLT) and hypoxia (FMiso). In this paper, a framework based on Belief Function Theory is proposed for BTV segmentation and for creating 3D parametric images for dose painting. We propose to take advantage of neighboring voxels for BTV segmentation, and also multi-tracer PET images using information fusion to create parametric images. The performances of BTV segmentation was evaluated on an anthropomorphic phantom and compared with two other methods. Quantitative results show the good performances of our method. It has been applied to data of five patients suffering from lung cancer. Parametric images show promising results by highlighting areas where a high frequency or dose escalation could be planned.

  13. The Role of Spraying Parameters and Inert Gas Shrouding in Hybrid Water-Argon Plasma Spraying of Tungsten and Copper for Nuclear Fusion Applications

    NASA Astrophysics Data System (ADS)

    Matějíček, J.; Kavka, T.; Bertolissi, G.; Ctibor, P.; Vilémová, M.; Mušálek, R.; Nevrlá, B.

    2013-06-01

    Tungsten-based coatings have potential application in the plasma-facing components in future nuclear fusion reactors. By the combination of refractory tungsten with highly thermal conducting copper, or steel as a construction material, functionally graded coatings can be easily obtained by plasma spraying, and may result in the development of a material with favorable properties. During plasma spraying of these materials in the open atmosphere, oxidation is an important issue, which could have adverse effects on their properties. Among the means to control it is the application of inert gas shrouding, which forms the subject of this study and represents a lower-cost alternative to vacuum or low-pressure plasma spraying, potentially applicable also for spraying of large surfaces or spacious components. It is a continuation of recent studies focused on the effects of various parameters of the hybrid water-argon torch on the in-flight behavior of copper and tungsten powders and the resultant coatings. In the current study, argon shrouding with various configurations of the shroud was applied. The effects of torch parameters, such as power and argon flow rate, and powder morphology were also investigated. Their influence on the particle in-flight behavior as well as the structure, composition and properties of the coatings were quantified. With the help of auxiliary calculations, the mass changes of the powder particles, associated with oxidation and evaporation, were assessed.

  14. Cold fusion; Myth versus reality

    SciTech Connect

    Rabinowitz, M. )

    1990-01-01

    Experiments indicate that several different nuclear reactions are taking place. Some of the experiments point to D-D fusion with a cominant tritium channel as one of the reactions. The article notes a similarity between Prometheus and the discoveries of cold fusion.

  15. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    SciTech Connect

    Sarantites, D.G.

    1990-01-01

    This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP).

  16. Architecture of CRM1/Exportin1 suggests how cooperativity is achieved during formation of a nuclear export complex.

    PubMed

    Petosa, Carlo; Schoehn, Guy; Askjaer, Peter; Bauer, Ulrike; Moulin, Martine; Steuerwald, Ulrich; Soler-López, Montserrat; Baudin, Florence; Mattaj, Iain W; Müller, Christoph W

    2004-12-03

    CRM1/Exportin1 mediates the nuclear export of proteins bearing a leucine-rich nuclear export signal (NES) by forming a cooperative ternary complex with the NES-bearing substrate and the small GTPase Ran. We present a structural model of human CRM1 based on a combination of X-ray crystallography, homology modeling, and electron microscopy. The architecture of CRM1 resembles that of the import receptor transportin1, with 19 HEAT repeats and a large loop implicated in Ran binding. Residues critical for NES recognition are identified adjacent to the cysteine residue targeted by leptomycin B (LMB), a specific CRM1 inhibitor. We present evidence that a conformational change of the Ran binding loop accounts for the cooperativity of Ran- and substrate binding and for the selective enhancement of CRM1-mediated export by the cofactor RanBP3. Our findings indicate that a single architectural and mechanistic framework can explain the divergent effects of RanGTP on substrate binding by many import and export receptors.

  17. Magnetized Target Fusion: Prospects for Low-Cost Fusion Energy

    NASA Technical Reports Server (NTRS)

    Siemon, Richard E.; Turchi, Peter J.; Barnes, Daniel C.; Degnan, James; Parks, Paul; Ryutov, Dmitri D.; Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    Magnetized Target Fusion (MTF) has attracted renewed interest in recent years because it has the potential to resolve one of the major problems with conventional fusion energy research - the high cost of facilities to do experiments and in general develop practical fusion energy. The requirement for costly facilities can be traced to fundamental constraints. The Lawson condition implies large system size in the case of conventional magnetic confinement, or large heating power in the case of conventional inertial confinement. The MTF approach is to use much higher fuel density than with conventional magnetic confinement (corresponding to megabar pressures), which results in a much-reduced system size to achieve Lawson conditions. Intrinsically the system must be pulsed because the pressures exceed the strength of any known material. To facilitate heating the fuel (or "target") to thermonuclear conditions with a high-power high-intensity source of energy, magnetic fields are used to insulate the high-pressure fuel from material surroundings (thus "magnetized target"). Because of magnetic insulation, the required heating power intensity is reduced by many orders of magnitude compared to conventional inertial fusion, even with relatively poor energy confinement in the magnetic field, such as that characterized by Bohm diffusion. In this paper we show semi-quantitatively why MTF-should allow fusion energy production without costly facilities within the same generally accepted physical constraints used for conventional magnetic and inertial fusion. We also briefly discuss potential applications of this technology ranging from nuclear rockets for space propulsion to a practical commercial energy system. Finally, we report on the exploratory research underway, and the interesting physics issues that arise in the MTF regime of parameters. Experiments at Los Alamos are focused on formation of a suitable plasma target for compression, utilizing the knowledge base for compact

  18. Soldier systems sensor fusion

    NASA Astrophysics Data System (ADS)

    Brubaker, Kathryne M.

    1998-08-01

    This paper addresses sensor fusion and its applications in emerging Soldier Systems integration and the unique challenges associated with the human platform. Technology that,provides the highest operational payoff in a lightweight warrior system must not only have enhanced capabilities, but have low power components resulting in order of magnitude reductions coupled with significant cost reductions. These reductions in power and cost will be achieved through partnership with industry and leveraging of commercial state of the art advancements in microelectronics and power sources. As new generation of full solution fire control systems (to include temperature, wind and range sensors) and target acquisition systems will accompany a new generation of individual combat weapons and upgrade existing weapon systems. Advanced lightweight thermal, IR, laser and video senors will be used for surveillance, target acquisition, imaging and combat identification applications. Multifunctional sensors will provide embedded training features in combat configurations allowing the soldier to 'train as he fights' without the traditional cost and weight penalties associated with separate systems. Personal status monitors (detecting pulse, respiration rate, muscle fatigue, core temperature, etc.) will provide commanders and highest echelons instantaneous medical data. Seamless integration of GPS and dead reckoning (compass and pedometer) and/or inertial sensors will aid navigation and increase position accuracy. Improved sensors and processing capability will provide earlier detection of battlefield hazards such as mines, enemy lasers and NBC (nuclear, biological, chemical) agents. Via the digitized network the situational awareness database will automatically be updated with weapon, medical, position and battlefield hazard data. Soldier Systems Sensor Fusion will ultimately establish each individual soldier as an individual sensor on the battlefield.

  19. Establishment of pregnancy after the transfer of nuclear transfer embryos produced from the fusion of argali (Ovis ammon) nuclei into domestic sheep (Ovis aries) enucleated oocytes.

    PubMed

    White, K L; Bunch, T D; Mitalipov, S; Reed, W A

    1999-01-01

    Cloning mammalian species from cell lines of adult animals has been demonstrated. Aside from its importance for cloning multiple copies of genetically valuable livestock, cloning now has the potential to salvage endangered or even extinct species. The aim of this study was to investigate the effect of the bovine and domestic (Ovis aries) ovine oocyte cytoplasm on the nucleus of an established cell line from an endangered argali wild sheep (Ovis ammon) after nuclear transplantation. A fibroblast cell line was established from skin biopsies from an adult argali ram from the People's Republic of China. Early karyotype analysis of cells between 3-6 passages revealed a normal diploid chromosome number of 56. The argali karyotype consisted of 2 pairs of biarmed and 25 pairs of acrocentric autosomes, a large acrocentric and minute biarmed Y. Bovine ovaries were collected from a local abattoir, oocytes aspirated, and immediately placed in maturation medium consisting of M-199 containing 10% fetal bovine serum, 100 IU/mL penicillin, 100 microg/mL streptomycin, 0.5 microg/mL follicle-stimulating hormone (FSH), 5.0 microg/mL luetinizing hormone (LH) and 1.0 microg/mL estradiol. Ovine (O. aries) oocytes were collected at surgery 25 hours postonset of estrus from the oviducts of superovulated donor animals. All cultures were carried out at 39 degrees C in a humidified atmosphere of 5% CO2 and air. In vitro matured MII bovine oocytes were enucleated 16-20 hours after onset of maturation and ovine oocytes within 2-3 hours after collection. Enucleation was confirmed using Hoechst 33342 and UV light. The donor argali cells were synchronized in G0-G1 phase by culturing in Dulbecco's modified Eagle's medium (DMEM) plus 0.5% fetal bovine serum for 5-10 days. Fusion of nuclear donor cell to an enucleated oocyte (cytoplast) to produce nuclear transfer (NT) embryos was induced by 2 electric pulses of 1.4 kV/cm for 30 microsc. Fused NT embryos were activated after 24 hours of maturation

  20. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

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

    PubMed

    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.

  2. 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

  3. EDITORIAL: Safety aspects of fusion power plants

    NASA Astrophysics Data System (ADS)

    Kolbasov, B. N.

    2007-07-01

    This special issue of Nuclear Fusion contains 13 informative papers that were initially presented at the 8th IAEA Technical Meeting on Fusion Power Plant Safety held in Vienna, Austria, 10-13 July 2006. Following recommendation from the International Fusion Research Council, the IAEA organizes Technical Meetings on Fusion Safety with the aim to bring together experts to discuss the ongoing work, share new ideas and outline general guidance and recommendations on different issues related to safety and environmental (S&E) aspects of fusion research and power facilities. Previous meetings in this series were held in Vienna, Austria (1980), Ispra, Italy (1983), Culham, UK (1986), Jackson Hole, USA (1989), Toronto, Canada (1993), Naka, Japan (1996) and Cannes, France (2000). The recognized progress in fusion research and technology over the last quarter of a century has boosted the awareness of the potential of fusion to be a practically inexhaustible and clean source of energy. The decision to construct the International Thermonuclear Experimental Reactor (ITER) represents a landmark in the path to fusion power engineering. Ongoing activities to license ITER in France look for an adequate balance between technological and scientific deliverables and complying with safety requirements. Actually, this is the first instance of licensing a representative fusion machine, and it will very likely shape the way in which a more common basis for establishing safety standards and policies for licensing future fusion power plants will be developed. Now that ITER licensing activities are underway, it is becoming clear that the international fusion community should strengthen its efforts in the area of designing the next generations of fusion power plants—demonstrational and commercial. Therefore, the 8th IAEA Technical Meeting on Fusion Safety focused on the safety aspects of power facilities. Some ITER-related safety issues were reported and discussed owing to their potential

  4. Role of Fusion Energy in a Sustainable Global Energy Strategy

    SciTech Connect

    Meier, W; Najmabadi, F; Schmidt, J; Sheffield, J

    2001-03-07

    Fusion energy is one of only a few truly long-term energy options. Since its inception in the 1950s, the vision of the fusion energy research program has been to develop a viable means of harnessing the virtually unlimited energy stored in the nuclei of light atoms--the primary fuel deuterium is present as one part in 6,500 of all hydrogen. This vision grew out of the recognition that the immense power radiated by the sun is fueled by nuclear fusion in its hot core. Such high temperatures are a prerequisite for driving significant fusion reactions. The fascinating fourth state of matter at high temperatures is known as plasma. It is only in this fourth state of matter that the nuclei of two light atoms can fuse, releasing the excess energy that was needed to separately bind each of the original two nuclei. Because the nuclei of atoms carry a net positive electric charge, they repel each other. Hydrogenic nuclei, such as deuterium and tritium, must be heated to approximately 100 million degrees Celsius to overcome this electric repulsion and fuse. There have been dramatic recent advances in both the scientific understanding of fusion plasmas and in the generation of fusion power in the laboratory. Today, there is little doubt that fusion energy production is feasible. For this reason, the general thrust of fusion research has focused on configuration improvements leading to an economically competitive product. The risk of conflicts arising from energy shortages and supply cutoffs, as well as the risk of severe environmental impacts from existing methods of energy production, are among the reasons to pursue these opportunities [1]. In this paper we review the tremendous scientific progress in fusion during the last 10 years. We utilize the detailed engineering design activities of burning plasma experiments as well as conceptual fusion power plant studies to describe our visions of attractive fusion power plants. We use these studies to compare technical requirements

  5. Spinal Fusion

    MedlinePlus

    ... concept of fusion is similar to that of welding in industry. Spinal fusion surgery, however, does not ... bone taken from the patient has a long history of use and results in predictable healing. Autograft ...

  6. Enhancement of Fusion Rate by Superthermal Tritium Ions

    NASA Astrophysics Data System (ADS)

    Castaldo, Carmine; Cardinali, Alessandro; Marinucci, Massimo

    2011-10-01

    We propose a new concept of a nuclear fusion reactor. It is based on the enhancement of the DT fusion rate in tokamak plasmas by a superthermal population of Tritium ions heated by ICRH. It was already shown that break-even conditions might be reached [C. Castaldo and A. Cardinali, Phys. Plasmas 17, 072513 (2010)]. Here we show that Q ~20, suitable for nuclear fusion power station, can be achieved in a compact tokamak configuration (major radius R=160cm, minor radius a=55cm, elongation k=1.9, triangularity δ=0.4, q95=3.5), operating with IP=8MA plasma current, BT=11.3T toroidal field, line averaged plasma density n=5X1020m-3, and 40% D, 35% H, 25% T concentrations of the Hydrogen isotopes. The burning plasma is obtained by the injection of 15 MW ICRF power, coupled by six antennas, with radiating areas of 0.25m2, at the operating frequency f=125 MHz and toroidal wave number n//=4. The heating scenario has been analyzed by the code TORIC, and approximated analytical equilibria are considered. As a result the total fusion power expected for the proposed scenario is about 350MW, with Q ~20, assuming that at least 70% of the fusion power carried by the α particles is absorbed by the electrons in the plasma core so that the expected central plasma temperature is about 10keV.

  7. Investigation of the Possibility of Using Nuclear Magnetic Spin Alignment

    NASA Technical Reports Server (NTRS)

    Dent, William V., Jr.

    1998-01-01

    The goal of the program to investigate a "Gasdynamic fusion propulsion system for space exploration" is to develop a fusion propulsion system for a manned mission to the planet mars. A study using Deuterium and Tritium atoms are currently in progress. When these atoms under-go fusion, the resulting neutrons and alpha particles are emitted in random directions (isotropically). The probable direction of emission is equal for all directions, thus resulting in wasted energy, massive shielding and cooling requirements, and serious problems with the physics of achieving fusion. If the nuclear magnetic spin moments of the deuterium and tritium nuclei could be precisely aligned at the moment of fusion, the stream of emitted neutrons could be directed out the rear of the spacecraft for thrust and the alpha particles directed forward into an electromagnet ot produce electricity to continue operating the fusion engine. The following supporting topics are discussed: nuclear magnetic moments and spin precession in magnetic field, nuclear spin quantum mechanics, kinematics of nuclear reactions, and angular distribution of particles.

  8. Tritium breeding in fusion reactors

    SciTech Connect

    Abdou, M.A.

    1982-10-01

    Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements.

  9. Radioscapholunate Fusions

    PubMed Central

    McGuire, Duncan Thomas; Bain, Gregory Ian

    2012-01-01

    Radiocarpal fusions are performed for a variety of indications, most commonly for debilitating painful arthritis. The goal of a wrist fusion is to fuse the painful, diseased joints and to preserve motion through the healthy joints. Depending on the extent of the disease process, radiocarpal fusions may take the form of radiolunate, radioscapholunate, or total wrist fusions. Surgical techniques and instrumentation have advanced over the last few decades, and consequently the functional outcomes have improved and complications decreased. Techniques for partial carpal fusions have improved and now include distal scaphoid and triquetrum excision, which improves range of motion and fusion rates. In this article we discuss the various surgical techniques and fixation methods available and review the corresponding evidence in the literature. The authors' preferred surgical technique of radioscapholunate fusion with distal scaphoid and triquetrum excision is outlined. New implants and new concepts are also discussed. PMID:24179717

  10. Magnetized Target Fusion

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.

    2002-01-01

    Magnetized target fusion (MTF) is under consideration as a means of building a low mass, high specific impulse, and high thrust propulsion system for interplanetary travel. This unique combination is the result of the generation of a high temperature plasma by the nuclear fusion process. This plasma can then be deflected by magnetic fields to provide thrust. Fusion is initiated by a small traction of the energy generated in the magnetic coils due to the plasma's compression of the magnetic field. The power gain from a fusion reaction is such that inefficiencies due to thermal neutrons and coil losses can be overcome. Since the fusion reaction products are directly used for propulsion and the power to initiate the reaction is directly obtained from the thrust generation, no massive power supply for energy conversion is required. The result should be a low engine mass, high specific impulse and high thrust system. The key is to successfully initiate fusion as a proof-of-principle for this application. Currently MSFC is implementing MTF proof-of-principle experiments. This involves many technical details and ancillary investigations. Of these, selected pertinent issues include the properties, orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the target plasma's behavior under compression and the convergence and mixing of the gun plasma are under investigation. This work is to focus on the gun characterization and development as it relates to plasma initiation and repeatability.

  11. A classical approach in simple nuclear fusion reaction {sub 1}H{sup 2}+{sub 1}H{sup 3} using two-dimension granular molecular dynamics model

    SciTech Connect

    Viridi, S.; Kurniadi, R.; Waris, A.; Perkasa, Y. S.

    2012-06-06

    Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between {sub 1}H{sup 2} and {sub 1}H{sup 3} is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary {sub 2}He{sup 4} nucleus.

  12. 76 FR 4645 - Fusion Energy Sciences Advisory Committee; Notice of Open Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... Fusion Nuclear Sciences Pathways Assessment Activities Public Comments Public Participation: The meeting... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Fusion... Science. SUMMARY: This notice announces a meeting of the Fusion Energy Sciences Advisory Committee....

  13. Simulation of Fusion Plasmas

    ScienceCinema

    Holland, Chris [UC San Diego, San Diego, California, United States

    2016-07-12

    The upcoming ITER experiment (www.iter.org) represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the “burning plasma” regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

  14. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are

  15. Prospects for inertial fusion as an energy source

    SciTech Connect

    Hogan, W.J.

    1989-06-26

    Progress in the Inertial Confinement Fusion (ICF) Program has been very rapid in the last few years. Target physics experiments with laboratory lasers and in underground nuclear tests have shown that the drive conditions necessary to achieve high gain can be achieved in the laboratory with a pulse-shaped driver of about 10 MJ. Requirements and designs for a Laboratory Microfusion Facility (LMF) have been formulated. Research on driver technology necessary for an ICF reactor is making progress. Prospects for ICF as an energy source are very promising. 11 refs., 5 figs.

  16. Cross Sections Calculations of ( d, t) Nuclear Reactions up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tel, E.; Yiğit, M.; Tanır, G.

    2013-04-01

    In nuclear fusion reactions two light atomic nuclei fuse together to form a heavier nucleus. Fusion power is the power generated by nuclear fusion processes. In contrast with fission power, the fusion reaction processes does not produce radioactive nuclides. The fusion will not produce CO2 or SO2. So the fusion energy will not contribute to environmental problems such as particulate pollution and excessive CO2 in the atmosphere. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production is still believed to be unlikely before 2050. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. In the fusion reactor, tritium self-sufficiency must be maintained for a commercial power plant. Therefore, for self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( d, t) nuclear reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. Since the experimental data of charged particle induced reactions are scarce, self-consistent calculation and analyses using nuclear theoretical models are very important. In this study, ( d, t) cross sections for target nuclei 19F, 50Cr, 54Fe, 58Ni, 75As, 89Y, 90Zr, 107Ag, 127I, 197Au and 238U have been investigated up to 50 MeV deuteron energy. The excitation functions for ( d, t) reactions have been calculated by pre-equilibrium reaction mechanism. Calculation results have been also compared with the available measurements in

  17. Applications of nuclear physics.

    PubMed

    Hayes, A C

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  18. Applications of nuclear physics

    DOE PAGES

    Hayes-Sterbenz, Anna Catherine

    2017-01-10

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applicationsmore » of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Lastly, each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.« less

  19. Applications of nuclear physics

    NASA Astrophysics Data System (ADS)

    Hayes, A. C.

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  20. Applications of Fusion Energy Sciences Research - Scientific Discoveries and New Technologies Beyond Fusion

    SciTech Connect

    Wendt, Amy; Callis, Richard; Efthimion, Philip; Foster, John; Keane, Christopher; Onsager, Terry; O'Shea, Patrick

    2015-09-01

    Since the 1950s, scientists and engineers in the U.S. and around the world have worked hard to make an elusive goal to be achieved on Earth: harnessing the reaction that fuels the stars, namely fusion. Practical fusion would be a source of energy that is unlimited, safe, environmentally benign, available to all nations and not dependent on climate or the whims of the weather. Significant resources, most notably from the U.S. Department of Energy (DOE) Office of Fusion Energy Sciences (FES), have been devoted to pursuing that dream, and significant progress is being made in turning it into a reality. However, that is only part of the story. The process of creating a fusion-based energy supply on Earth has led to technological and scientific achievements of far-reaching impact that touch every aspect of our lives. Those largely unanticipated advances, spanning a wide variety of fields in science and technology, are the focus of this report. There are many synergies between research in plasma physics (the study of charged particles and fluids interacting with self-consistent electric and magnetic fields), high-energy physics, and condensed matter physics dating back many decades. For instance, the formulation of a mathematical theory of solitons, solitary waves which are seen in everything from plasmas to water waves to Bose-Einstein Condensates, has led to an equal span of applications, including the fields of optics, fluid mechanics and biophysics. Another example, the development of a precise criterion for transition to chaos in Hamiltonian systems, has offered insights into a range of phenomena including planetary orbits, two-person games and changes in the weather. Seven distinct areas of fusion energy sciences were identified and reviewed which have had a recent impact on fields of science, technology and engineering not directly associated with fusion energy: Basic plasma science; Low temperature plasmas; Space and astrophysical plasmas; High energy density

  1. Image fusion

    NASA Technical Reports Server (NTRS)

    Pavel, M.

    1993-01-01

    The topics covered include the following: a system overview of the basic components of a system designed to improve the ability of a pilot to fly through low-visibility conditions such as fog; the role of visual sciences; fusion issues; sensor characterization; sources of information; image processing; and image fusion.

  2. Establishment of an Institute for Fusion Studies. Technical progress report, 1 November 1993--31 October 1994

    SciTech Connect

    Hazeltine, R.D.

    1994-07-01

    The Institute for Fusion Studies is a national center for theoretical fusion plasma physics research. Its purposes are: (1) to conduct research on theoretical questions concerning the achievement of controlled fusion energy by means of magnetic confinement--including both fundamental problems of long-range significance, as well as shorter-term issues; (2) to serve as a national and international center for information exchange by hosting exchange visits, conferences, and workshops; (3) and to train students and postdoctoral research personnel for the fusion energy program and plasma physics research areas. The theoretical research results obtained by the Institute contribute to the progress of nuclear fusion research, whose goal is the development of fusion power as a basic energy source. Close collaborative relationships have been developed with other university and national laboratory fusion groups, both in the US and abroad. In addition to its primary focus on mainstream fusion physics, the Institute is also involved with research in fusion-sidestream fields, such as advanced computing techniques, nonlinear dynamics, space plasmas and astrophysics, statistical mechanics, fluid dynamics, and accelerator physics. Important research discoveries are briefly described.

  3. Nuclear Science.

    ERIC Educational Resources Information Center

    Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum Services.

    This document is a report on a course in nuclear science for the high school curriculum. The course is designed to provide a basic but comprehensive understanding of the atom in the light of modern knowledge, and to show how people attempt to harness the tremendous energy liberated through fission and fusion reactions. The course crosses what are…

  4. Diagnosing inertial confinement fusion gamma ray physics (invited)a)

    NASA Astrophysics Data System (ADS)

    Herrmann, H. W.; Hoffman, N.; Wilson, D. C.; Stoeffl, W.; Dauffy, L.; Kim, Y. H.; McEvoy, A.; Young, C. S.; Mack, J. M.; Horsfield, C. J.; Rubery, M.; Miller, E. K.; Ali, Z. A.

    2010-10-01

    The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10-5γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional γ-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available γ-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV γ-rays produced by inelastic scatter of DT fusion neutrons on C12 nuclei in the ablating plastic capsule material.

  5. Diagnosing inertial confinement fusion gamma ray physics (invited).

    PubMed

    Herrmann, H W; Hoffman, N; Wilson, D C; Stoeffl, W; Dauffy, L; Kim, Y H; McEvoy, A; Young, C S; Mack, J M; Horsfield, C J; Rubery, M; Miller, E K; Ali, Z A

    2010-10-01

    The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10(-5)γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional γ-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available γ-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV γ-rays produced by inelastic scatter of DT fusion neutrons on (12)C nuclei in the ablating plastic capsule material.

  6. ICENES '91:Sixth international conference on emerging nuclear energy systems

    SciTech Connect

    Not Available

    1991-01-01

    This document contains the program and abstracts of the sessions at the Sixth International Conference on Emerging Nuclear Energy Systems held June 16--21, 1991 at Monterey, California. These sessions included: The plenary session, fission session, fission and nonelectric session, poster session 1P; (space propulsion, space nuclear power, electrostatic confined fusion, fusion miscellaneous, inertial confinement fusion, [mu]-catalyzed fusion, and cold fusion); Advanced fusion session, space nuclear session, poster session 2P, (nuclear reactions/data, isotope separation, direct energy conversion and exotic concepts, fusion-fission hybrids, nuclear desalting, accelerator waste-transmutation, and fusion-based chemical recycling); energy policy session, poster session 3P (energy policy, magnetic fusion reactors, fission reactors, magnetically insulated inertial fusion, and nuclear explosives for power generation); exotic energy storage and conversion session; and exotic energy storage and conversion; review and closing session.

  7. Fusion Policy Advisory Committee (FPAC)

    SciTech Connect

    Not Available

    1990-09-01

    This document is the final report of the Fusion Policy Advisory Committee. The report conveys the Committee's views on the matters specified by the Secretary in his charge and subsequent letters to the Committee, and also satisfies the provisions of Section 7 of the Magnetic Fusion Energy Engineering Act of 1980, Public Law 96-386, which require a triennial review of the conduct of the national Magnetic Fusion Energy program. Three sub-Committee's were established to address the large number of topics associated with fusion research and development. One considered magnetic fusion energy, a second considered inertial fusion energy, and the third considered issues common to both. For many reasons, the promise of nuclear fusion as a safe, environmentally benign, and affordable source of energy is bright. At the present state of knowledge, however, it is uncertain that this promise will become reality. Only a vigorous, well planned and well executed program of research and development will yield the needed information. The Committee recommends that the US commit to a plan that will resolve this critically important issue. It also outlines the first steps in a development process that will lead to a fusion Demonstration Power Plant by 2025. The recommended program is aggressive, but we believe the goal is reasonable and attainable. International collaboration at a significant level is an important element in the plan.

  8. Ceramics for fusion applications

    SciTech Connect

    Clinard, F.W. Jr.

    1986-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al/sub 2/O/sub 3/, MgAl/sub 2/O/sub 4/, BeO, Si/sub 3/N/sub 4/ and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications.

  9. Nuclear reprogramming.

    PubMed

    Halley-Stott, Richard P; Pasque, Vincent; Gurdon, J B

    2013-06-01

    There is currently particular interest in the field of nuclear reprogramming, a process by which the identity of specialised cells may be changed, typically to an embryonic-like state. Reprogramming procedures provide insight into many mechanisms of fundamental cell biology and have several promising applications, most notably in healthcare through the development of human disease models and patient-specific tissue-replacement therapies. Here, we introduce the field of nuclear reprogramming and briefly discuss six of the procedures by which reprogramming may be experimentally performed: nuclear transfer to eggs or oocytes, cell fusion, extract treatment, direct reprogramming to pluripotency and transdifferentiation.

  10. Network-centric data fusion

    NASA Astrophysics Data System (ADS)

    Nicholson, David; Lloyd, C. M.; Collins, Peter R. C.

    2002-08-01

    The performance of three distributed sensor fusion network architectures is investigated: a fully-connected and a partially-connected measurement fusion system and a partially-connected track fusion system. The investigation employs an advanced military scenario generator, FLAMES, which was customised for exercising a range of distributed data fusion experiments. Specifically, it includes a representative model of the delays in a communication system (such as JTIDS or Link 16). Here the delays were used to modify communication bandwidth and to evaluate how this affected the performance of the fusion architectures/algorithms. Under certain specific scenario conditions, it was found that decentralised measurement fusion system was severely affected by reduced bandwidth. This is because each node loads its communication buffer with every measurement and consequently some measurements are never transmitted. The decentralised track fusion system exhibits improved performance because it lumps measurements into tracks and thereby it makes much more effective use of the bandwidth. Moreover, it was found that the performance of the partially connected decentralised track fusion system was very close to the optimal performance achieved by the fully-connected decentralised measurement fusion system.

  11. Economic potential of inertial fusion

    SciTech Connect

    Nuckolls, J.H.

    1984-04-01

    Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents.

  12. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

    Discusses the extraordinary potential, the technical difficulties, and the financial problems that are associated with research and development of fusion power plants as a major source of energy. (GA)

  13. Establishment of an Institute for Fusion Studies. Technical progress report, November 1, 1991--October 31, 1992

    SciTech Connect

    Hazeltine, R.D.

    1992-07-01

    The Institute for Fusion Studies is a national center for theoretical fusion plasma physics research. Its purposes are: (1) to conduct research on theoretical questions concerning the achievement of controlled fusion energy by means of magnetic confinement--including both fundamental problems of long-range significance, as well as shorter-term issues; (2) to serve as a center for information exchange, nationally and internationally, by hosting exchange visits, conferences, and workshops; (3) and to train students and postdoctoral research personnel for the fusion energy program and plasma physics research areas. The theoretical research results that are obtained by the Institute contribute mainly to the progress of national and international efforts in nuclear fusion research, whose goal is the development of fusion power.as a basic energy source. In addition to its primary focus on fusion physics, the Institute is also involved with research in related fields, such as advanced computing techniques, nonlinear dynamics, plasma astrophysics, and accelerator physics. The work of EFS scientists continued to receive national and international recognition. Numerous invited papers were given during the past year at workshops, conferences, and scientific meetings. Last year IFS scientists published 95 scientific articles in technical journals and monographs.

  14. Fusion materials science and technology research opportunities now and during the ITER era

    SciTech Connect

    S.J. Zinkle; J.P. Planchard; R.W. Callis; C.E. Kessel; P.J. Lee; K.A. McCarty; Various Others

    2014-10-01

    Several high-priority near-term potential research activities to address fusion nuclear science challenges are summarized. General recommendations include: (1) Research should be preferentially focused on the most technologically advanced options (i.e., options that have been developed at least through the singleeffects concept exploration stage, technology readiness levels >3), (2) Significant near-term progress can be achieved by modifying existing facilities and/or moderate investment in new medium-scale facilities, and (3) Computational modeling for fusion nuclear sciences is generally not yet sufficiently robust to enable truly predictive results to be obtained, but large reductions in risk, cost and schedule can be achieved by careful integration of experiment and modeling.

  15. Mars manned fusion spaceship

    SciTech Connect

    Hedrick, J.; Buchholtz, B.; Ward, P.; Freuh, J.; Jensen, E.

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium. Helium can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  16. Mars manned fusion spaceship

    NASA Technical Reports Server (NTRS)

    Hedrick, James; Buchholtz, Brent; Ward, Paul; Freuh, Jim; Jensen, Eric

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  17. Tritium accountancy in fusion systems

    SciTech Connect

    Klein, J.E.; Clark, E.A.; Harvel, C.D.; Farmer, D.A.; Tovo, L.L.; Poore, A.S.; Moore, M.L.

    2015-03-15

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MCA) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MCA requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBA) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material sub-accounts (MSA) are established along with key measurement points (KMP) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSA. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breeding, burn-up, and retention of tritium in the fusion device. The concept of 'net' tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines. (authors)

  18. TRITIUM ACCOUNTANCY IN FUSION SYSTEMS

    SciTech Connect

    Klein, J. E.; Farmer, D. A.; Moore, M. L.; Tovo, L. L.; Poore, A. S.; Clark, E. A.; Harvel, C. D.

    2014-03-06

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MC&A) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MC&A requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBAs) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material subaccounts (MSAs) are established along with key measurement points (KMPs) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSAs. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breading, burn-up, and retention of tritium in the fusion device. The concept of “net” tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines.

  19. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are

  20. Nuclear energy.

    PubMed

    Grandin, Karl; Jagers, Peter; Kullander, Sven

    2010-01-01

    Nuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow's energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues. If successfully developed, such reactors may have an important and sustainable part in future energy production. Working fusion reactors may be even more materials efficient and environmental friendly, but also need more development and research. The roadmap for development of fourth generation fission and fusion reactors, therefore, asks for attention and research in these fields must be strengthened.

  1. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schmidt, George R.; Santarius, John F.; Turchi, Peter J.; Siemon, Richard E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The need for fusion propulsion for interplanetary flights is discussed. For a propulsion system, there are three important system attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For efficient and affordable human exploration of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion obviously cannot meet the requirement in propellant exhaust velocity. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the fission energy to heat a low atomic weight propellant produces propellant velocity of the order of 10 kinds. Alternatively the fission energy can be converted into electricity that is used to accelerate particles to high exhaust velocity. However, the necessary power conversion and conditioning equipment greatly increases the mass of the propulsion system. Fundamental considerations in waste heat rejection and power conditioning in a fission electric propulsion system place a limit on its jet specific power to the order of about 0.2 kW/kg. If fusion can be developed for propulsion, it appears to have the best of all worlds - it can provide the largest absolute amount of energy, the propellant exhaust velocity (> 100 km/s), and the high specific jet power (> 10 kW/kg). An intermediate step towards fusion propulsion might be a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. There are similarities as well as differences between applying fusion to propulsion and to terrestrial electrical power generation. The similarities are the underlying plasma and fusion physics, the enabling component technologies, the computational and the diagnostics capabilities. These physics and

  2. Neutron transport-burnup code MCORGS and its application in fusion fission hybrid blanket conceptual research

    NASA Astrophysics Data System (ADS)

    Shi, Xue-Ming; Peng, Xian-Jue

    2016-09-01

    Fusion science and technology has made progress in the last decades. However, commercialization of fusion reactors still faces challenges relating to higher fusion energy gain, irradiation-resistant material, and tritium self-sufficiency. Fusion Fission Hybrid Reactors (FFHR) can be introduced to accelerate the early application of fusion energy. Traditionally, FFHRs have been classified as either breeders or transmuters. Both need partition of plutonium from spent fuel, which will pose nuclear proliferation risks. A conceptual design of a Fusion Fission Hybrid Reactor for Energy (FFHR-E), which can make full use of natural uranium with lower nuclear proliferation risk, is presented. The fusion core parameters are similar to those of the International Thermonuclear Experimental Reactor. An alloy of natural uranium and zirconium is adopted in the fission blanket, which is cooled by light water. In order to model blanket burnup problems, a linkage code MCORGS, which couples MCNP4B and ORIGEN-S, is developed and validated through several typical benchmarks. The average blanket energy Multiplication and Tritium Breeding Ratio can be maintained at 10 and 1.15 respectively over tens of years of continuous irradiation. If simple reprocessing without separation of plutonium from uranium is adopted every few years, FFHR-E can achieve better neutronic performance. MCORGS has also been used to analyze the ultra-deep burnup model of Laser Inertial Confinement Fusion Fission Energy (LIFE) from LLNL, and a new blanket design that uses Pb instead of Be as the neutron multiplier is proposed. In addition, MCORGS has been used to simulate the fluid transmuter model of the In-Zinerater from Sandia. A brief comparison of LIFE, In-Zinerater, and FFHR-E will be given.

  3. G-protein coupled receptor 56 promotes myoblast fusion through serum response factor- and nuclear factor of activated T-cell-mediated signalling but is not essential for muscle development in vivo.

    PubMed

    Wu, Melissa P; Doyle, Jamie R; Barry, Brenda; Beauvais, Ariane; Rozkalne, Anete; Piao, Xianhua; Lawlor, Michael W; Kopin, Alan S; Walsh, Christopher A; Gussoni, Emanuela

    2013-12-01

    Mammalian muscle cell differentiation is a complex process of multiple steps for which many of the factors involved have not yet been defined. In a screen to identify the regulators of myogenic cell fusion, we found that the gene for G-protein coupled receptor 56 (GPR56) was transiently up-regulated during the early fusion of human myoblasts. Human mutations in the gene for GPR56 cause the disease bilateral frontoparietal polymicrogyria; however, the consequences of receptor dysfunction on muscle development have not been explored. Using knockout mice, we defined the role of GPR56 in skeletal muscle. GPR56(-/-) myoblasts have decreased fusion and smaller myotube sizes in culture. In addition, a loss of GPR56 expression in muscle cells results in decreases or delays in the expression of myogenic differentiation 1, myogenin and nuclear factor of activated T-cell (NFAT)c2. Our data suggest that these abnormalities result from decreased GPR56-mediated serum response element and NFAT signalling. Despite these changes, no overt differences in phenotype were identified in the muscle of GPR56 knockout mice, which presented only a mild but statistically significant elevation of serum creatine kinase compared to wild-type. In agreement with these findings, clinical data from 13 bilateral frontoparietal polymicrogyria patients revealed mild serum creatine kinase increase in only two patients. In summary, targeted disruption of GPR56 in mice results in myoblast abnormalities. The absence of a severe muscle phenotype in GPR56 knockout mice and human patients suggests that other factors may compensate for the lack of this G-protein coupled receptor during muscle development and that the motor delay observed in these patients is likely not a result of primary muscle abnormalities.

  4. CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification.

    PubMed

    Baccou, C; Yahia, V; Depierreux, S; Neuville, C; Goyon, C; Consoli, F; De Angelis, R; Ducret, J E; Boutoux, G; Rafelski, J; Labaune, C

    2015-08-01

    Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.

  5. Magnetic fusion 1985: what next

    SciTech Connect

    Fowler, T.K.

    1985-03-01

    Recent budget reductions for magnetic fusion have led to a re-examination of program schedules and objectives. Faced with delays and postponement of major facilities as previously planned, some have called for a near-term focus on science, others have stressed technology. This talk will suggest a different focus as the keynote for this conference, namely, the applications of fusion. There is no doubt that plasma science is by now mature and fusion technology is at the forefront. This has and will continue to benefit many fields of endeavor, both in actual new discoveries and techniques and in attracting and training scientists and engineers who move on to make significant contributions in science, defense and industry. Nonetheless, however superb the science or how challenging the technology, these are means, not ends. To maintain its support, the magnetic fusion program must also offer the promise of power reactors that could be competitive in the future. At this conference, several new reactor designs will be described that claim to be smaller and economically competitive with fission reactors while retaining the environmental and safety characteristics that are the hallmark of fusion. The American Nuclear Society is an appropriate forum in which to examine these new designs critically, and to stimulate better ideas and improvements. As a preview, this talk will include brief discussions of new tokamak, tandem mirror and reversed field pinch reactor designs to be presented in later sessions. Finally, as a preview of the session on fusion breeders, the talk will explore once again the economic implications of a new nuclear age, beginning with improved fission reactors fueled by fusion breeders, then ultimately evolving to reactors based solely on fusion.

  6. (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.

  7. Study of fusion Q-value rule in sub-barrier fusion of heavy ions

    NASA Astrophysics Data System (ADS)

    Liu, Xing-Xing; Zhang, Gao-Long; Zhang, Huan-Qiao

    2015-07-01

    A vast body of fusion data has been analyzed for different projectiles and target nuclei. It is indicated that the sub-barrier fusion depends on the fusion Q-value. In terms of a recently introduced fusion Q-value rule and an energy scaling reduction procedure, the experimental fusion excitation functions are reduced and compared with each other. It is found that the reduced fusion excitations of selected fusion systems show a similar trend. The fusion data for massive nuclei are in agreement with the Q-value rule. In the fusion process, the Q contribution should be considered. Within this approach, the sub-barrier fusion cross sections of most fusion systems can be predicted without involving any structure effects of colliding nuclei. Instances of disagreement are presented in a few fusion systems. The use of the energy scaling as a criterion of possible experimental data inconsistency is discussed. More precise experimental fusion data need to be measured. Supported by National Nature Science Foundation of China (11475013, 11035007, 11175011), State Key Laboratory of Software Development Environment (SKLSDE-2014ZX-08), Fundamental Research Funds for the Central Universities and the Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences

  8. Magnetized Target Fusion Collaboration. Final report

    SciTech Connect

    Slough, John

    2012-04-18

    Nuclear fusion has the potential to satisfy the prodigious power that the world will demand in the future, but it has yet to be harnessed as a practical energy source. The entry of fusion as a viable, competitive source of power has been stymied by the challenge of finding an economical way to provide for the confinement and heating of the plasma fuel. It is the contention here that a simpler path to fusion can be achieved by creating fusion conditions in a different regime at small scale (~ a few cm). One such program now under study, referred to as Magnetized Target Fusion (MTF), is directed at obtaining fusion in this high energy density regime by rapidly compressing a compact toroidal plasmoid commonly referred to as a Field Reversed Configuration (FRC). To make fusion practical at this smaller scale, an efficient method for compressing the FRC to fusion gain conditions is required. In one variant of MTF a conducting metal shell is imploded electrically. This radially compresses and heats the FRC plasmoid to fusion conditions. The closed magnetic field in the target plasmoid suppresses the thermal transport to the confining shell, thus lowering the imploding power needed to compress the target. The undertaking described in this report was to provide a suitable target FRC, as well as a simple and robust method for inserting and stopping the FRC within the imploding liner. The FRC must also survive during the time it takes for the metal liner to compress the FRC target. The initial work at the UW was focused on developing adequate preionization and flux trapping that were found to be essential in past experiments for obtaining the density, flux and most critically, FRC lifetime required for MTF. The timescale for testing and development of such a source can be rapidly accelerated by taking advantage of a new facility funded by the Department of Energy. At this facility, two inductive plasma accelerators (IPA) were constructed and tested. Recent experiments with

  9. World progress toward fusion energy

    NASA Astrophysics Data System (ADS)

    Clarke, J. F.

    1989-09-01

    This paper will describe the progress in fusion science and technology from a world perspective. The paper will cover the current technical status, including the understanding of fusion's economic, environmental, and safety characteristics. Fusion experiments are approaching the energy breakeven condition. An energy gain (Q) of 30 percent has been achieved in magnetic confinement experiments. In addition, temperatures required for an ignited plasma (Ti = 32 KeV) and energy confinements (about 75 percent of that required for ignition) have been achieved in separate experiments. Two major facilities have started the experimental campaign to extend these results and achieve or exceed Q = 1 plasma conditions by 1990. Inertial confinement fusion experiments are also approaching thermonuclear conditions and have achieved a compression factor 100-200 times liquid D-T. Because of this progress, the emphasis in fusion research is turning toward questions of engineering feasibility. Leaders of the major fusion R and D programs in the European Community (EC), Japan, the United States, and the U.S.S.R. have agreed on the major steps that are needed to reach the point at which a practical fusion system can be designed. The United States is preparing for an experiment to address the last unexplored scientific issue, the physics of an ignited plasma, during the late 1990's. The EC, Japan, U.S.S.R., and the United States have joined together under the auspices of the International Atomic Energy Agency (IAEA) to jointly design and prepare the validating R&D for an international facility, the International Thermonuclear Experimental Reactor (ITER), to address all the remaining scientific issues and to explore the engineering technology of fusion around the turn of the century.

  10. Comprehensive Nuclear Materials

    SciTech Connect

    Konings, Dr. Rudy J. M.; Allen, Todd R.; Stoller, Roger E; Yamanaka, Prof. Shinsuke

    2012-01-01

    This book encompasses a rich seam of current information on the vast and multidisciplinary field of nuclear materials employed in fission and prototype fusion systems. Discussion includes both historical and contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds leading scientists and engineers. Synthesizes pertinent current science to support the selection, assessment, validation and engineering of materials in extreme nuclear environments. The work discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials.

  11. Cold Fusion Verification.

    DTIC Science & Technology

    1991-03-01

    published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater ...way of N-rays and polywater . To date, no one, including Pons and Fleischmann, has been able to construct a so-called CNF electrochemical cell that...Cold Nuclear Fusion (CNF), as originally reported in 1989. The conclusion is that CNF probably is chimera and will go the way of N-rays and polywater

  12. Fusion reactor pumped laser

    DOEpatents

    Jassby, Daniel L.

    1988-01-01

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

  13. JPRS Report Nuclear Developments

    DTIC Science & Technology

    2007-11-02

    release; Distribution Unlimited | -—fb 40 Nuclear Developments JPRS-TND-88-016 CONTENTS 2 SEPTEMBER 1988 CHINA Nuclear Power Chief Seeks...Foreign Cooperation [Yuan Zhou; CHINA DAILY (BUSINESS WEEKLY) 1 Aug 88] 1 Nuclear Fusion Study Reaches Advanced Level [Xiao Longlian; Beijing...Government ’Welcomes’ Group [Beijing XINHUA 12 Aug 88] 4 No Decision on Disposal of Daya Nuclear Waste [Andy Ho; Hong Kong SOUTH CHINA MORNING POST

  14. Spinal fusion

    MedlinePlus

    Liu G, Wong HK. Laminectomy and fusion. In: Shen FH, Samartzis D, Fessler RG, eds. Textbook of the Cervical Spine . Philadelphia, PA: Elsevier Saunders; 2015:chap 34. Wood GW. Arthrodesis of the spine. In: Canale ST, Beaty JH, eds. Campbell's Operative ...

  15. Laser glass: a key material in the search for fusion energy

    SciTech Connect

    Campbell, J H

    1999-06-02

    Nuclear fusion is the energy source that powers the sun. For more than four decades man has sought to develop this essentially inexhaustible, clean power source for use on earth. Unfortunately the conditions needed to initiate fusion are daunting; the nuclear fuel, consisting of isotopes of hydrogen, must be heated to temperatures in excess of 100,000,000 C and maintained at that temperature long enough for the nuclear fuel to ignite and burn. Lasers are being used as one of the tools to achieve these conditions. The best lasers for this work are those that derive their energy from a unique set of optical glasses called laser glasses. The work to develop, manufacture and test these glasses has involved a partnership between university and industry that has spanned more than 25 years. During this time lasers used in fusion development have grown from small systems that could fit on the top of a table to systems currently under construction that are approximately the size of a municipal sports stadium. A brief historical and anecdotal account of the development of laser glasses for fusion energy research applications is the subject of the presentation.

  16. Tritium and workers in fusion devices-lessons learnt.

    PubMed

    Rodriguez-Rodrigo, Lina; Elbez-Uzan, Joelle; Alejaldre, Carlos

    2009-09-01

    Fusion machines from all over the world have contributed to the knowledge accumulated in fusion science. This knowledge has been applied to design new experimental fusion machines and in particular ITER. Only two fusion devices based on magnetic confinement have used deuterium and tritium fuels to-date-the Tokamak Fusion Test Reactor, TFTR, in Princeton, USA, and JET, the European tokamak. These machines have demonstrated that the fusion reaction is achievable with these fuels, and have provided valuable lessons on radioprotection-related issues as concerns tritium and workers. Dedicated tritium installations for fusion research and development have also contributed to this knowledge base.

  17. Information integration for data fusion

    SciTech Connect

    Bray, O.H.

    1997-01-01

    Data fusion has been identified by the Department of Defense as a critical technology for the U.S. defense industry. Data fusion requires combining expertise in two areas - sensors and information integration. Although data fusion is a rapidly growing area, there is little synergy and use of common, reusable, and/or tailorable objects and models, especially across different disciplines. The Laboratory-Directed Research and Development project had two purposes: to see if a natural language-based information modeling methodology could be used for data fusion problems, and if so, to determine whether this methodology would help identify commonalities across areas and achieve greater synergy. The project confirmed both of the initial hypotheses: that the natural language-based information modeling methodology could be used effectively in data fusion areas and that commonalities could be found that would allow synergy across various data fusion areas. The project found five common objects that are the basis for all of the data fusion areas examined: targets, behaviors, environments, signatures, and sensors. Many of the objects and the specific facts related to these objects were common across several areas and could easily be reused. In some cases, even the terminology remained the same. In other cases, different areas had their own terminology, but the concepts were the same. This commonality is important with the growing use of multisensor data fusion. Data fusion is much more difficult if each type of sensor uses its own objects and models rather than building on a common set. This report introduces data fusion, discusses how the synergy generated by this LDRD would have benefited an earlier successful project and contains a summary information model from that project, describes a preliminary management information model, and explains how information integration can facilitate cross-treaty synergy for various arms control treaties.

  18. Object recognition approach based on feature fusion

    NASA Astrophysics Data System (ADS)

    Wang, Runsheng

    2001-09-01

    Multi-sensor information fusion plays an important pole in object recognition and many other application fields. Fusion performance is tightly depended on the fusion level selected and the approach used. Feature level fusion is a potential and difficult fusion level though there might be mainly three fusion levels. Two schemes are developed for key issues of feature level fusion in this paper. In feature selecting, a normal method developed is to analyze the mutual relationship among the features that can be used, and to be applied to order features. In object recognition, a multi-level recognition scheme is developed, whose procedure can be controlled and updated by analyzing the decision result obtained in order to achieve a final reliable result. The new approach is applied to recognize work-piece objects with twelve classes in optical images and open-country objects with four classes based on infrared image sequence and MMW radar. Experimental results are satisfied.

  19. Stabilized Spheromak Fusion Reactors

    SciTech Connect

    Fowler, T

    2007-04-03

    The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

  20. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

  1. Current status and recent research achievements in SiC/SiC composites

    NASA Astrophysics Data System (ADS)

    Katoh, Y.; Snead, L. L.; Henager, C. H.; Nozawa, T.; Hinoki, T.; Iveković, A.; Novak, S.; Gonzalez de Vicente, S. M.

    2014-12-01

    The silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) composite system for fusion applications has seen a continual evolution from development a fundamental understanding of the material system and its behavior in a hostile irradiation environment to the current effort which is directed at a broad-based program of technology maturation program. In essence, over the past few decades this material system has steadily moved from a laboratory curiosity to an engineering material, both for fusion structural applications and other high performance application such as aerospace. This paper outlines the recent international scientific and technological achievements towards the development of SiC/SiC composite material technologies for fusion application and discusses future research directions. It also reviews the materials system in the larger context of progress to maturity as an engineering material for both the larger nuclear community and broader engineering applications.

  2. Fusion of Epstein-Barr virus nuclear antigen-1-derived glycine-alanine repeat to trans-dominant HIV-1 Gag increases inhibitory activities and survival of transduced cells in vivo.

    PubMed

    Hammer, Diana; Wild, Jens; Ludwig, Christine; Asbach, Benedikt; Notka, Frank; Wagner, Ralf

    2008-06-01

    Trans-dominant human immunodeficiency virus type 1 (HIV-1) Gag derivatives have been shown to efficiently inhibit late steps of HIV-1 replication in vitro by interfering with Gag precursor assembly, thus ranking among the interesting candidates for gene therapy approaches. However, efficient antiviral activities of corresponding transgenes are likely to be counteracted in particular by cell-mediated host immune responses toward the transgene-expressing cells. To decrease this potential immunogenicity, a 24-amino acid Gly-Ala (GA) stretch derived from Epstein-Barr virus nuclear antigen-1 (EBNA1) and known to overcome proteasomal degradation was fused to a trans-dominant Gag variant (sgD1). To determine the capacity of this fusion polypeptide to repress viral replication, PM-1 cells were transduced with sgD1 and GAsgD1 transgenes, using retroviral gene transfer. Challenge of stably transfected permissive cell lines with various viral strains indicated that N-terminal GA fusion even enhanced the inhibitory properties of sgD1. Further studies revealed that the GA stretch increased protein stability by blocking proteasomal degradation of Gag proteins. Immunization of BALB/c mice with a DNA vaccine vector expressing sgD1 induced substantial Gag-specific immune responses that were, however, clearly diminished in the presence of GA. Furthermore, recognition of cells expressing the GA-fused transgene by CD8(+) T cells was drastically reduced, both in vitro and in vivo, resulting in prolonged survival of the transduced cells in recipient mice.

  3. Nonconventional applications of nuclear technology to space

    SciTech Connect

    Woodall, D.M.; Dolan, T.J. )

    1991-01-01

    The application of nuclear energy to power and propulsion to support President Bush's Space Exploration Initiative (SEI) has received considerable technical attention. This paper discusses the application of other nuclear technologies in space, including nuclear fusion, advanced accelerator research, antimatter research, nuclear technologies for exploration and mining, and nuclear astronomy.

  4. Fusion Propulsion Z-Pinch Engine Concept

    NASA Technical Reports Server (NTRS)

    Miernik, J.; Statham, G.; Fabisinski, L.; Maples, C. D.; Adams, R.; Polsgrove, T.; Fincher, S.; Cassibry, J.; Cortez, R.; Turner, M.; Percy, T.

    2011-01-01

    Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Due to the great distances between the planets of our solar system and the harmful radiation environment of interplanetary space, high specific impulse (Isp) propulsion in vehicles with high payload mass fractions must be developed to provide practical and safe vehicles for human spaceflight missions. The Z-Pinch dense plasma focus method is a Magneto-Inertial Fusion (MIF) approach that may potentially lead to a small, low cost fusion reactor/engine assembly1. Recent advancements in experimental and theoretical understanding of this concept suggest favorable scaling of fusion power output yield 2. The magnetic field resulting from the large current compresses the plasma to fusion conditions, and this process can be pulsed over short timescales (10(exp -6 sec). This type of plasma formation is widely used in the field of Nuclear Weapons Effects testing in the defense industry, as well as in fusion energy research. A Decade Module 2 (DM2), approx.500 KJ pulsed-power is coming to the RSA Aerophysics Lab managed by UAHuntsville in January, 2012. A Z-Pinch propulsion concept was designed for a vehicle based on a previous fusion vehicle study called "Human Outer Planet Exploration" (HOPE), which used Magnetized Target Fusion (MTF) 3 propulsion. The reference mission is the transport of crew and cargo to Mars and back, with a reusable vehicle.

  5. A universal support vector machines based method for automatic event location in waveforms and video-movies: applications to massive nuclear fusion databases.

    PubMed

    Vega, J; Murari, A; González, S

    2010-02-01

    Big physics experiments can collect terabytes (even petabytes) of data under continuous or long pulse basis. The measurement systems that follow the temporal evolution of physical quantities translate their observations into very large time-series data and video-movies. This article describes a universal and automatic technique to recognize and locate inside waveforms and video-films both signal segments with data of potential interest for specific investigations and singular events. The method is based on regression estimations of the signals using support vector machines. A reduced number of the samples is shown as outliers in the regression process and these samples allow the identification of both special signatures and singular points. Results are given with the database of the JET fusion device: location of sawteeth in soft x-ray signals to automate the plasma incremental diffusivity computation, identification of plasma disruptive behaviors with its automatic time instant determination, and, finally, recognition of potential interesting plasma events from infrared video-movies.

  6. ICENES `91:Sixth international conference on emerging nuclear energy systems. Program and abstracts

    SciTech Connect

    Not Available

    1991-12-31

    This document contains the program and abstracts of the sessions at the Sixth International Conference on Emerging Nuclear Energy Systems held June 16--21, 1991 at Monterey, California. These sessions included: The plenary session, fission session, fission and nonelectric session, poster session 1P; (space propulsion, space nuclear power, electrostatic confined fusion, fusion miscellaneous, inertial confinement fusion, {mu}-catalyzed fusion, and cold fusion); Advanced fusion session, space nuclear session, poster session 2P, (nuclear reactions/data, isotope separation, direct energy conversion and exotic concepts, fusion-fission hybrids, nuclear desalting, accelerator waste-transmutation, and fusion-based chemical recycling); energy policy session, poster session 3P (energy policy, magnetic fusion reactors, fission reactors, magnetically insulated inertial fusion, and nuclear explosives for power generation); exotic energy storage and conversion session; and exotic energy storage and conversion; review and closing session.

  7. 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.

  8. Study on the Feasibility of Direct Fusion Energy Conversion for Deep-Space Propulsion

    NASA Astrophysics Data System (ADS)

    Tarditi, Alfonso G.; Miley, George H.; Scott, John H.

    2012-10-01

    A significant change in the current space mission capabilities can be achieved with a highly efficient integration of a fusion energy source with an advanced space propulsion thruster, both with low specific mass. With aneutronic nuclear fusion as the high-density primary energy source, this study considers first electric energy extraction from the fusion reaction products via direct energy conversion to recirculate power as required for the operation of the fusion core. Then the beam of remaining reaction products is conditioned to achieve the optimal thrust and specific impulse for the mission. The research is specifically focused on two key issues: (i) Efficiency improvement of a Traveling Wave Direct Energy Converter (TWDEC, [1]) by achieving a higher ion beam density and optimization of the electrode coupling and of the neutralizing electron flow. (ii) A fast-particle kinetic energy-to-thrust conversion process based on collective interaction between ion bunches well separated in space [2]. Computer simulation results and a design for a basic physics experiment currently under development are reported. [4pt] [1] H. Momota et al., Fus. Tech., 35, 60(1999)[0pt] [2] A. G. Tarditi et al. Proc. NETS 2012 Conf., Woodlands, TX (2012)

  9. Inertial fusion: strategy and economic potential

    SciTech Connect

    Nuckolls, J.H.

    1983-01-01

    Inertial fusion must demonstrate that the high target gains required for practical fusion energy can be achieved with driver energies not larger than a few megajoules. Before a multi-megajoule scale driver is constructed, inertial fusion must provide convincing experimental evidence that the required high target gains are feasible. This will be the principal objective of the NOVA laser experiments. Implosions will be conducted with scaled targets which are nearly hydrodynamically equivalent to the high gain target implosions. Experiments which demonstrate high target gains will be conducted in the early nineties when multi-megajoule drivers become available. Efficient drivers will also be demonstrated by this time period. Magnetic fusion may demonstrate high Q at about the same time as inertial fusion demonstrates high gain. Beyond demonstration of high performance fusion, economic considerations will predominate. Fusion energy will achieve full commercial success when it becomes cheaper than fission and coal. Analysis of the ultimate economic potential of inertial fusion suggests its costs may be reduced to half those of fission and coal. Relative cost escalation would increase this advantage. Fusions potential economic advantage derives from two fundamental properties: negligible fuel costs and high quality energy (which makes possible more efficient generation of electricity).

  10. Heterogeneous Vision Data Fusion for Independently Moving Cameras

    DTIC Science & Technology

    2010-03-01

    transformed images . This work achieves the fusion of images ...wavelet transforms W of the two registered input images I1(m,n) and I2(m,n) are computed and these transforms are combined using some kind of fusion ... image transform , image registration, image fusion , and target detection. This research doesn’t assume that multiple cameras are mounted on the

  11. Outlook for the fusion hybrid and tritium-breeding fusion reactors

    NASA Astrophysics Data System (ADS)

    Richardson, J. M.; Cohen, R.; Simpson, J. W.

    The study examines the outlook for fusion hybrid reactors. The study evaluates the status of fusion hybrid technology in the United States and analyzes the circumstances under which such reactors might be deployed. The study also examines a related concept, the tritium-breeding fusion reactor. The study examined two potential applications for fusion hybrid technology: (1) the production of fissile material to fuel light-water reactors, and (2) the direct production of baseload electricity. For both applications, markets were sufficiently problematical or remote (mid-century or later) to warrant only modest current research and development emphasis on technology specific to the fusion hybrid reactor. For the tritium-breeding fusion reactor, a need for tritium for use in nuclear weapons might arise well before the middle of the next century, so that a program of design studies, experimentation, and evaluation should be undertaken.

  12. Fusion reactions at low energy

    SciTech Connect

    Beckerman, M.

    1985-01-01

    Fusion measurement methods at low energies are briefly described, and experimental and theoretical fusion cross sections for /sup 58/Ni + /sup 58/Ni, /sup 58/Ni + /sup 64/Ni and /sup 64/Ni + /sup 64/Ni reactions are discussed. It is shown that quantal tunneling calculations do not describe the near- and sub-barrier behavior of the fusion data. Instead, the WKB predictions fall progressively further blow the experimental results as the energy is lowered. At far subbarrier energies the measured cross sections exceed the WKB predictions by more than three orders of magnitude. The unexpectedly strong dependence of the fusion probability upon the nuclear valence structure is illustrated and discussed. The relationship of channel coupling and quantal tunneling is discussed. In conclusion, it was established that atomic nuclei fuse far more readily at low energies that would be expected from quantal tunneling considerations alone. It was found that the behavior of the cross sections for fusion depends strongly upon the valence structure of the collision partners. This structural dependence extends from light 1p-shell systems to systems involving nearly 200 nucleons. These new phenomena may be viewed as characterizing the tunneling of a quantal system with many degrees of freedom. The failure of standard tunneling models may be understood as resulting from the ability of the dinuclear system to tunnel into the classically forbidden region by means of couplings to intrinsic degrees of freedom. 38 refs. (WHK)

  13. Advanced fission and fossil plant economics-implications for fusion

    SciTech Connect

    Delene, J.G.

    1994-09-01

    In order for fusion energy to be a viable option for electric power generation, it must either directly compete with future alternatives or serve as a reasonable backup if the alternatives become unacceptable. This paper discusses projected costs for the most likely competitors with fusion power for baseload electric capacity and what these costs imply for fusion economics. The competitors examined include advanced nuclear fission and advanced fossil-fired plants. The projected costs and their basis are discussed. The estimates for these technologies are compared with cost estimates for magnetic and inertial confinement fusion plants. The conclusion of the analysis is that fusion faces formidable economic competition. Although the cost level for fusion appears greater than that for fission or fossil, the costs are not so high as to preclude fusion`s potential competitiveness.

  14. [On Atomic Nuclear Fusion Processes at Low-Temperatures. An Enhancement of the Probability of Transition through a Potential Barrier Due to the So-Called Barrier Anti-Zeno Effect].

    PubMed

    Namiot, V A

    2016-01-01

    It is known that in quantum mechanics the act of observing the experiment can affect the experimental findings in some cases. In particular, it happens under the so-called Zeno effect. In this work it is shown that in contrast to the "standard" Zeno-effect where the act of observing a process reduces the probability of its reality, an inverse situation when a particle transmits through a potential barrier (a so-called barrier anti-Zeno effect) can be observed, the observation of the particle essentially increases the probability of its transmission through the barrier. The possibility of using the barrier anti-Zeno effect is discussed to explain paradoxical results of experiments on "cold nuclear fusion" observed in various systems including biological ones. (According to the observers who performed the observations, the energy generation, which could not be explained by any chemical processes, as well as the change in the isotope and even element composition of the studied object may occur in these systems.

  15. The Fusion Energy Option

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    2004-06-01

    Presentations from a Fusion Power Associates symposium, The Fusion Energy Option, are summarized. The topics include perspectives on fossil fuel reserves, fusion as a source for hydrogen production, status and plans for the development of inertial fusion, planning for the construction of the International Thermonuclear Experimental Reactor, status and promise of alternate approaches to fusion and the need for R&D now on fusion technologies.

  16. Effects of intrinsic degrees of freedom in enhancement of sub-barrier fusion excitation function data and energy-dependent one-dimensional barrier penetration model

    NASA Astrophysics Data System (ADS)

    Gautam, M. S.

    2016-03-01

    We have analyzed the role of barrier modification effects (barrier height, barrier position, barrier curvature) introduced due to the energy-dependent Woods-Saxon potential model (EDWSP model) and the coupled channel model on the sub-barrier fusion dynamics of {}_{16}^{32,36} {{S}} + {}_{40}^{90,96} {{Zr}} reactions. The influence of inelastic surface excitations of colliding pairs and multi-neutron transfer channels is found to be a dominant mode of couplings. The coupling of relative motion of colliding nuclei to these dominant intrinsic degrees of freedom leads to a substantially large fusion enhancement at below-barrier energies over the expectations of one-dimensional barrier penetration model. The coupled channel calculations based upon static Woods-Saxon potential must include the internal nuclear structure degrees of freedom of colliding nuclei for complete description of experimental data. On the other hand, theoretical calculations based upon the EDWSP model along with Wong formula provide a complete description of sub-barrier fusion enhancement of various heavy-ion fusion reactions. In EDWSP model calculations, significantly larger values of diffuseness parameter ranging from a = 0.98 fm to a = 0.85 fm are required to address the observed sub-barrier fusion enhancement of {}_{16}^{32,36} {{S}} + {}_{40}^{90,96} {{Zr}} reactions. Furthermore, within the context of EDWSP model, it is possible to achieve an agreement with the experimental fusion cross-sectional data within 10 %. For four heavy-ion fusion reactions, only at 4 fusion data points out of 90 fusion data points deviates exceeding 5 %, while 86 fusion data points lie within 5 % and hence the EDWSP model is able to account the above-barrier portion of the fusion cross-sectional data within 5 % with a probability greater than 90 %.

  17. Safety of magnetic fusion facilities: Requirements

    SciTech Connect

    1996-05-01

    This Standard identifies safety requirements for magnetic fusion facilities. Safety functions are used to define outcomes that must be achieved to ensure that exposures to radiation, hazardous materials, or other hazards are maintained within acceptable limits. Requirements applicable to magnetic fusion facilities have been derived from Federal law, policy, and other documents. In addition to specific safety requirements, broad direction is given in the form of safety principles that are to be implemented and within which safety can be achieved.

  18. Impact of Energy Gain and Subsystem Characteristics on Fusion Propulsion Performance

    NASA Technical Reports Server (NTRS)

    Chakrabarti, S.; Schmidt, G. R.

    2001-01-01

    Rapid transport of large payloads and human crews throughout the solar system requires propulsion systems having very high specific impulse (I(sub sp) > 10(exp 4) to 10(exp 5) s). It also calls for systems with extremely low mass-power ratios (alpha < 10(exp -1) kg/kW). Such low alpha are beyond the reach of conventional power-limited propulsion, but may be attainable with fusion and other nuclear concepts that produce energy within the propellant. The magnitude of energy gain must be large enough to sustain the nuclear process while still providing a high jet power relative to the massive energy-intensive subsystems associated with these concepts. This paper evaluates the impact of energy gain and subsystem characteristics on alpha. Central to the analysis are general parameters that embody the essential features of any 'gain-limited' propulsion power balance. Results show that the gains required to achieve alpha = 10(exp -1) kg/kW with foreseeable technology range from approximately 100 to over 2000, which is three to five orders of magnitude greater than current fusion state of the arL Sensitivity analyses point to the parameters exerting the most influence for either: (1) lowering a and improving mission performance or (2) relaxing gain requirements and reducing demands on the fusion process. The greatest impact comes from reducing mass and increasing efficiency of the thruster and subsystems downstream of the fusion process. High relative gain, through enhanced fusion processes or more efficient drivers and processors, is also desirable. There is a benefit in improving driver and subsystem characteristics upstream of the fusion process, but it diminishes at relative gains > 100.

  19. Successful anterior fusion following posterior cervical fusion for revision of anterior cervical discectomy and fusion pseudarthrosis.

    PubMed

    Elder, Benjamin D; Sankey, Eric W; Theodros, Debebe; Bydon, Mohamad; Goodwin, C Rory; Lo, Sheng-Fu; Kosztowski, Thomas A; Belzberg, Allen J; Wolinsky, Jean-Paul; Sciubba, Daniel M; Gokaslan, Ziya L; Bydon, Ali; Witham, Timothy F

    2016-02-01

    Pseudarthrosis occurs after approximately 2-20% of anterior cervical discectomy and fusion (ACDF) procedures; it is unclear if posterior or anterior revision should be pursued. In this study, we retrospectively evaluate the outcomes in 22 patients with pseudarthrosis following ACDF and revision via posterior cervical fusion (PCF). Baseline demographics, preoperative symptoms, operative data, time to fusion failure, symptoms of pseudarthrosis, and revision method were assessed. Fusion outcome and clinical outcome were determined at last follow-up (LFU). Thirteen females (59%) and 9 (41%) males experienced pseudarthrosis at a median of 11 (range: 3-151)months after ACDF. Median age at index surgery was 51 (range: 33-67)years. All patients with pseudarthrosis presented with progressive neck pain, with median visual analog scale (VAS) score of 8 (range: 0-10), and/or myeloradiculopathy. Patients with pseudarthrosis <12 months compared to >12 months after index surgery were older (p=0.013), had more frequent preoperative neurological deficits (p=0.064), and lower baseline VAS scores (p=0.006). Fusion was successful after PCF in all patients, with median time to fusion of 10 (range: 2-14)months. Eighteen patients fused both anteriorly and posteriorly, two patients fused anteriorly only, and two patients fused posteriorly only. Median VAS neck score at LFU significantly improved from the time of pseudarthrosis (p=0.012). While uncommon, pseudarthrosis may occur after ACDF. All patients achieved successful fusion after subsequent posterior cervical fusion, with 91% fusing a previous anterior pseudarthrosis after posterior stabilization. Neck pain significantly improved by LFU in the majority of patients in this study.

  20. Fusion reactor pumped laser

    DOEpatents

    Jassby, D.L.

    1987-09-04

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

  1. Inertial confinement fusion

    SciTech Connect

    Powers, L.; Condouris, R.; Kotowski, M.; Murphy, P.W.

    1992-01-01

    This issue of the ICF Quarterly contains seven articles that describe recent progress in Lawrence Livermore National Laboratory's ICF program. The Department of Energy recently initiated an effort to design a 1--2 MJ glass laser, the proposed National Ignition Facility (NIF). These articles span various aspects of a program which is aimed at moving forward toward such a facility by continuing to use the Nova laser to gain understanding of NIF-relevant target physics, by developing concepts for an NIF laser driver, and by envisioning a variety of applications for larger ICF facilities. This report discusses research on the following topics: Stimulated Rotational Raman Scattering in Nitrogen; A Maxwell Equation Solver in LASNEX for the Simulation of Moderately Intense Ultrashort Pulse Experiments; Measurements of Radial Heat-Wave Propagation in Laser-Produced Plasmas; Laser-Seeded Modulation Growth on Directly Driven Foils; Stimulated Raman Scattering in Large-Aperture, High-Fluence Frequency-Conversion Crystals; Fission Product Hazard Reduction Using Inertial Fusion Energy; Use of Inertial Confinement Fusion for Nuclear Weapons Effects Simulations.

  2. Non-electric applications for magneto-inertial fusion

    NASA Astrophysics Data System (ADS)

    Slough, John

    2016-10-01

    In addition to the generation of commercial electric power, there are several other applications for an intense pulse of neutrons that would be produced by magneto-inertial fusion (MIF) systems. Many of these applications can be achieved without the need for a fully developed reactor at high gain, and could thus be pursued at a much earlier stage of development which would dramatically reduce the risk of the long-term development and concern for the expense of an all-encompassing, single use system such as the tokamak or stellerator. A short list of applications well suited for MIF would include: (1) production of radioisotopes for medical applications and research, (2) efficient, high power propulsion through direct fusion heating of lithium propellants (3) Noninvasive interrogation of objects for homeland security (4) neutron radiography and tomography (5) destruction of long-lived radioactive waste, and (6) breeding of proliferation proof fissile fuel for existing nuclear reactors. These applications could all be pursued at lower neutron yield, but clearly the energy goals are by far the most significant and far reaching such as applying fusion energy as a hybrid to enable thorium cycle reactors which produce very little waste compared to the current uranium reactors. A discussion of how MIF could be configured and utilized to realize several of these uses will be discussed.

  3. Research on stellarator-mirror fission-fusion hybrid

    NASA Astrophysics Data System (ADS)

    Moiseenko, V. E.; Kotenko, V. G.; Chernitskiy, S. V.; Nemov, V. V.; Ågren, O.; Noack, K.; Kalyuzhnyi, V. N.; Hagnestål, A.; Källne, J.; Voitsenya, V. S.; Garkusha, I. E.

    2014-09-01

    The development of a stellarator-mirror fission-fusion hybrid concept is reviewed. The hybrid comprises of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is the transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, neutrons are generated in deuterium-tritium (D-T) plasma, confined magnetically in a stellarator-type system with an embedded magnetic mirror. Based on kinetic calculations, the energy balance for such a system is analyzed. Neutron calculations have been performed with the MCNPX code, and the principal design of the reactor part is developed. Neutron outflux at different outer parts of the reactor is calculated. Numerical simulations have been performed on the structure of a magnetic field in a model of the stellarator-mirror device, and that is achieved by switching off one or two coils of toroidal field in the Uragan-2M torsatron. The calculations predict the existence of closed magnetic surfaces under certain conditions. The confinement of fast particles in such a magnetic trap is analyzed.

  4. Fission or fusion for Mars missions - Expectations and challenges

    NASA Astrophysics Data System (ADS)

    Kammash, Terry

    1993-10-01

    A fission-based system in the form of the Gas Core Nuclear Rocket (GCR) and a laser-driven inertial fusion system that utilizes a self-generated magnetic field (MICF) are compared as potential propulsion systems for manned planetary travel. The first generates thrust by a hydrogen propellant that is heated by radiation emitted from a critical reactor with a uranium fuel in plasma form, to take advantage of high achievable temperatures. The fusion system produces attractive propulsion characteristics through energy magnification of a hot hydrogenous plasma which is guided by a magnetic nozzle that allows thermal energy to be converted into thrust. Each system faces some formidable physics and engineering problems that must be addressed if they are to become viable propulsion systems. With the aid of an appropriate set of fluid and plasma equations, we assess the dynamics of each system and identify those issues that could detract from their performance. In the case of GCR, thermal hydraulic considerations reveal deterioration of propulsive capability when wall heat flux limitations and turbulent mixing are taken into account. Moreover, hydrodynamics and acoustic instabilities could also adversely affect its performance, although they may be amenable to stabilization by magnetic fields. For MICF, large energy multiplication at modest input laser energies appears to be a major concern, but if antihydrogen can be used to initiate the fusion reactions, this concept can be truly an outstanding propulsion device.

  5. 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.

  6. A New Innovative Spherical Cermet Nuclear Fuel Element to Achieve an Ultra-Long Core Life for use in Grid-Appropriate LWRs

    SciTech Connect

    Senor, David J.; Painter, Chad L.; Geelhood, Ken J.; Wootan, David W.; Meriwether, George H.; Cuta, Judith M.; Adkins, Harold E.; Matson, Dean W.; Abrego, Celestino P.

    2007-12-01

    Spherical cermet fuel elements are proposed for use in the Atoms For Peace Reactor (AFPR-100) concept. AFPR-100 is a small-scale, inherently safe, proliferation-resistant reactor that would be ideal for deployment to nations with emerging economies that decide to select nuclear power for the generation of carbon-free electricity. The basic concept of the AFPR core is a water-cooled fixed particle bed, randomly packed with spherical fuel elements. The flow of coolant within the particle bed is at such a low rate that the bed does not fluidize. This report summarizes an approach to fuel fabrication, results associated with fuel performance modeling, core neutronics and thermal hydraulics analyses demonstrating a ~20 year core life, and a conclusion that the proliferation resistance of the AFPR reactor concept is high.

  7. Personnel Safety for Future Magnetic Fusion Power Plants

    SciTech Connect

    Lee Cadwallader

    2009-07-01

    The safety of personnel at existing fusion experiments is an important concern that requires diligence. Looking to the future, fusion experiments will continue to increase in power and operating time until steady state power plants are achieved; this causes increased concern for personnel safety. This paper addresses four important aspects of personnel safety in the present and extrapolates these aspects to future power plants. The four aspects are personnel exposure to ionizing radiation, chemicals, magnetic fields, and radiofrequency (RF) energy. Ionizing radiation safety is treated well for present and near-term experiments by the use of proven techniques from other nuclear endeavors. There is documentation that suggests decreasing the annual ionizing radiation exposure limits that have remained constant for several decades. Many chemicals are used in fusion research, for parts cleaning, as use as coolants, cooling water cleanliness control, lubrication, and other needs. In present fusion experiments, a typical chemical laboratory safety program, such as those instituted in most industrialized countries, is effective in protecting personnel from chemical exposures. As fusion facilities grow in complexity, the chemical safety program must transition from a laboratory scale to an industrial scale program that addresses chemical use in larger quantity. It is also noted that allowable chemical exposure concentrations for workers have decreased over time and, in some cases, now pose more stringent exposure limits than those for ionizing radiation. Allowable chemical exposure concentrations have been the fastest changing occupational exposure values in the last thirty years. The trend of more restrictive chemical exposure regulations is expected to continue into the future. Other issues of safety importance are magnetic field exposure and RF energy exposure. Magnetic field exposure limits are consensus values adopted as best practices for worker safety; a typical

  8. Control of a laser inertial confinement fusion-fission power plant

    DOEpatents

    Moses, Edward I.; Latkowski, Jeffery F.; Kramer, Kevin J.

    2015-10-27

    A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

  9. Magnetized Target Fusion and Prospects for Truly Low-Cost Energy

    NASA Astrophysics Data System (ADS)

    Simon, Richard E.

    1998-04-01

    As the world population grows, and standards of living improve, the demand for energy will increase considerably. At the same time, the importance of shifting away from burning fossil fuel and reducing emissions of CO2 is becoming widely recognized. Many technologies are possible in principle, but nuclear fission or nuclear fusion are among the more promising. Fission is technically well established, continues to be improved in its economics, reliability and safety, and in this speaker's opinion is bound to play a major role. Fusion is generally viewed as a long shot that remains to be proven technically. Not everyone realizes that fusion tokamak devices studied around the world have demonstrated impressive scientific advances. In recent years, tokamaks TFTR at Princeton and JET at Culham have come close to demonstrating energy break even. Some recent tokamak data will be described. The main problem with the tokamak is that it must operate with a very large unit size (many Gigawatts) for well-understood fundamental reasons. Consequently, tokamak cost of development is high, even invoking international collaborations to build future facilities such as the proposed 10-billion dollar International Thermonuclear Tokamak Reactor. An exciting alternative approach to fusion being examined at Los Alamos in collaboration with LLNL, SNL, AFRL, GA, PPPL, and other institutions is called Magnetized Target Fusion. The basic idea is to burn a small amount of DT fuel in a short very-high-pressure pulse. The 14-MeV neutrons produced by the fusion reactions could then be used to flash heat a blanket of lithium or lithium-containing material to a temperature of 10,000 to 20,000 degrees Kelvin. The vaporized neutron-absorbing blanket thus becomes a hot working fluid, which can be used to create electricity by passing it through a magnetohydrodynamic generator. Estimates of the capital cost for such a system are even lower than for fission reactors, suggesting 2-cent

  10. Mitochondrial fusion is essential for steroid biosynthesis.

    PubMed

    Duarte, Alejandra; Poderoso, Cecilia; Cooke, Mariana; Soria, Gastón; Cornejo Maciel, Fabiana; Gottifredi, Vanesa; Podestá, Ernesto J

    2012-01-01

    Although the contribution of mitochondrial dynamics (a balance in fusion/fission events and changes in mitochondria subcellular distribution) to key biological process has been reported, the contribution of changes in mitochondrial fusion to achieve efficient steroid production has never been explored. The mitochondria are central during steroid synthesis and different enzymes are localized between the mitochondria and the endoplasmic reticulum to produce the final steroid hormone, thus suggesting that mitochondrial fusion might be relevant for this process. In the present study, we showed that the hormonal stimulation triggers mitochondrial fusion into tubular-shaped structures and we demonstrated that mitochondrial fusion does not only correlate-with but also is an essential step of steroid production, being both events depend on PKA activity. We also demonstrated that the hormone-stimulated relocalization of ERK1/2 in the mitochondrion, a critical step during steroidogenesis, depends on mitochondrial fusion. Additionally, we showed that the SHP2 phosphatase, which is required for full steroidogenesis, simultaneously modulates mitochondrial fusion and ERK1/2 localization in the mitochondrion. Strikingly, we found that mitofusin 2 (Mfn2) expression, a central protein for mitochondrial fusion, is upregulated immediately after hormone stimulation. Moreover, Mfn2 knockdown is sufficient to impair steroid biosynthesis. Together, our findings unveil an essential role for mitochondrial fusion during steroidogenesis. These discoveries highlight the importance of organelles' reorganization in specialized cells, prompting the exploration of the impact that organelle dynamics has on biological processes that include, but are not limited to, steroid synthesis.

  11. Direct Fusion Drive for a Human Mars Orbital Mission

    SciTech Connect

    Paluszek, Michael; Pajer, Gary; Razin, Yosef; Slonaker, James; Cohen, Samuel; Feder, Russ; Griffin, Kevin; Walsh, Matthew

    2014-08-01

    The Direct Fusion Drive (DFD) is a nuclear fusion engine that produces both thrust and electric power. It employs a field reversed configuration with an odd-parity rotating magnetic field heating system to heat the plasma to fusion temperatures. The engine uses deuterium and helium-3 as fuel and additional deuterium that is heated in the scrape-off layer for thrust augmentation. In this way variable exhaust velocity and thrust is obtained.

  12. Impact of Reaction Cross Section on the Unified Description of Fusion Excitation Function

    NASA Astrophysics Data System (ADS)

    Basrak, Z.; Eudes, P.; de la Mota, V.; Sébille, F.; Royer, G.

    A systematics of over 300 complete and incomplete fusion cross section data points covering energies beyond the barrier for fusion is presented. Owing to a usual reduction of the fusion cross sections by the total reaction cross sections and an original scaling of energy, a fusion excitation function common to all the data points is established. A universal description of the fusion exci- tation function relying on basic nuclear concepts is proposed and its dependence on the reaction cross section used for the cross section normalization is discussed. The pioneering empirical model proposed by Bass in 1974 to describe the complete fusion cross sections is rather successful for the incomplete fusion too and provides cross section predictions in satisfactory agreement with the observed universality of the fusion excitation function. The sophisticated microscopic transport DYWAN model not only reproduces the data but also predicts that fusion reaction mechanism disappears due to weakened nuclear stopping power around the Fermi energy.

  13. Fusion energy

    NASA Astrophysics Data System (ADS)

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the Max Planck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989 to 1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R and D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R and D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  14. Fusion energy

    SciTech Connect

    Not Available

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the MaxPlanck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989--1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  15. Effects of ROCK inhibitor Y-27632 on cell fusion through a microslit.

    PubMed

    Wada, Ken-Ichi; Hosokawa, Kazuo; Ito, Yoshihiro; Maeda, Mizuo

    2015-11-01

    We previously reported a direct cytoplasmic transfer method using a microfluidic device, in which cell fusion was induced through a microslit (slit-through-fusion) by the Sendai virus envelope (HVJ-E) to prevent nuclear mixing. However, the method was impractical due to low efficiency of slit-through-fusion formation and insufficient prevention of nuclear mixing. The purpose of this study was to establish an efficient method for inducing slit-through-fusion without nuclear mixing. We hypothesized that modulation of cytoskeletal component can decrease nuclear migration through the microslit considering its functions. Here we report that supplementation with Y-27632, a specific ROCK inhibitor, significantly enhances cell fusion induction and prevention of nuclear mixing. Supplementation with Y-27632 increased the formation of slit-through-fusion efficiency by more than twofold. Disruption of F-actin by Y-27632 prevented nuclear migration between fused cells through the microslit. These two effects of Y-27632 led to promotion of the slit-through-fusion without nuclear mixing with a 16.5-fold higher frequency compared to our previous method (i.e., cell fusion induction by HVJ-E without supplementation with Y-27632). We also confirmed that mitochondria were successfully transferred to the fusion partner under conditions of Y-27632 supplementation. These findings demonstrate the practicality of our cell fusion system in producing direct cytoplasmic transfer between live cells.

  16. Prospects for fusion neutron NPLs

    SciTech Connect

    Petra, M.; Miley, G.H.; Batyrbekov, E.; Jassby, D.L.; McArthur, D.

    1996-05-01

    To date, nuclear pumped lasers (NPLs) have been driven by neutrons from pulsed research fission reactors. However, future applications using either a Magnetic Confinement Fusion (MCF) neutron source or an Inertial Confinement Fusion (ICF) source appear attractive. One unique combination proposed earlier would use a neutron feedback NPL driver in an ICF power plant. 14-MeV D-T neutrons (and 2.5-MeV D-D neutrons) provide a unique opportunity for a neutron recoil pumped NPL. Alternatively, these neutrons can be thermalized to provide thermal-neutron induced reactions for pumping. Initial experience with a fusion-pumped NPL can possibly be obtained using the D-T burn experiments in progress/planning at the Tokamak Fusion Test Reactor (TFTR) and Joint European Torus (JET) tokamak devices or at the planned National Ignition Facility (NIF) high-gain ICF target experimental facility. With neutron fluxes presently available, peak thermalized fluxes at a test laser in the shield region could exceed 10{sup 14} n/cm{sup 2}/sec. Several low-threshold NPLs might be utilized in such an experiment, including the He-Ne-H{sub 2} NPL and the Ar-Xe NPL. Experimental set-ups for both the tokamak and the NIF will be described. {copyright} {ital 1996 American Institute of Physics.}

  17. Magnetic Inertial Confinement Fusion (MICF)

    NASA Astrophysics Data System (ADS)

    Miao, Feng; Zheng, Xianjun; Deng, Baiquan; Liu, Wei; Ou, Wei; Huang, Yi

    2016-11-01

    Based on the similarity in models of the early Sun and the 3-D common focal region of the micro-pinch in X-pinch experiments, a novel hybrid fusion configuration by continuous focusing of multiple Z-pinched plasma beams on spatially symmetric plasma is proposed. By replacing gravity with Lorentz force with subsequent centripetal spherical pinch, the beam-target fusion reactivity is enhanced in a quasi-spherical converging region, thus achieving MICF. An assessment, presented here, suggests that a practical fusion power source could be achieved using deuterium alone. Plasma instabilities can be suppressed by fast rotation resulting from an asymmetric tangential torsion in the spherical focal region of this configuration. Mathematical equivalence with the Sun allows the development of appropriate equations for the focal region of MICF, which are solved numerically to provide density, temperature and pressure distributions that produce net fusion energy output. An analysis of MICF physics and a preliminary experimental demonstration of a single beam are also carried out. supported by National Natural Science Foundation of China (Nos. 11374217 and 11176020)

  18. Fusion rates for hydrogen isotopic molecules of relevance for 'cold fusion'

    NASA Astrophysics Data System (ADS)

    Szalewicz, K.; Morgan, J. D., III; Monkhorst, H. J.

    1989-09-01

    In response to the recent announcements of evidence for room-temperature fusion in the electrolysis of D2O, an analysis is presented of how the fusion rate depends on the reduced mass of the fusing nuclei, the effective mass of a 'heavy' electron, and the degree of vibrational excitation. The results have been obtained both by accurately solving the Schroedinger equation for the hydrogen molecule and by using the WKB approximation. It is found that in light of the reported d-d fusion rate, the excess heat in the experiment by Fleischmann, Pons, and Hawkins is difficult to explain in terms of conventional nuclear processes.

  19. Investigation of condensed matter fusion

    SciTech Connect

    Jones, S.E.; Berrondo, M.; Czirr, J.B.; Decker, D.L.; Harrison, K.; Jensen, G.L.; Palmer, E.P.; Rees, L.B.; Taylor, S.; Vanfleet, H.B.; Wang, J.C.; Bennion, D.N.; Harb, J.N.; Pitt, W.G.; Thorne, J.M.; Anderson, A.N.; McMurtry, G.; Murphy, N.; Goff, F.E.

    1990-12-01

    Work on muon-catalyzed fusion led to research on a possible new type of fusion occurring in hydrogen isotopes embedded in metal lattices. While the nuclear-product yields observed to date are so small as to require careful further checking, rates observed over short times appear sufficiently large to suggest that significant neutrons and triton yields could be realized -- if the process could be understood and controlled. During 1990, we have developed two charged-particle detection systems and three new neutron detectors. A segmented, high-efficiency neutron counter was taken into 600 m underground in a mine in Colorado for studies out of the cosmic-ray background. Significant neutron emissions were observed in this environment in both deuterium-gas-loaded metals and in electrolytic cells, confirming our earlier observations.

  20. Particle beam fusion progress report for 1989

    SciTech Connect

    Sweeney, M.A.

    1994-08-01

    This report summarizes the progress on the pulsed power approach to inertial confinement fusion. In 1989, the authors achieved a proton focal intensity of 5 TW/cm{sup 2} on PBFA-II in a 15-cm-radius applied magnetic-field (applied-B) ion diode. This is an improvement by a factor of 4 compared to previous PBFA-II experiments. They completed development of the three-dimensional (3-D), electromagnetic, particle-in-cell code QUICKSILVER and obtained the first 3-D simulations of an applied-B ion diode. The simulations, together with analytic theory, suggest that control of electromagnetic instabilities could reduce ion divergence. In experiments using a lithium fluoride source, they delivered 26 kJ of lithium energy to the diode axis. Rutherford-scattered ion diagnostics have been developed and tested using a conical foil located inside the diode. They can now obtain energy density profiles by using range filters and recording ion images on nuclear track recording film. Timing uncertainties in power flow experiments on PBFA-II have been reduced by a factor of 5. They are investigating three plasma opening switches that use magnetic fields to control and confine the injected plasma. These new switches provide better power flow than the standard plasma erosion switch. Advanced pulsed-power fusion drivers will require extraction-geometry applied-B ion diodes. During this reporting period, progress was made in evaluating the generation, transport, and focus of multiple ion beams in an extraction geometry and in assessing the probable damage to a target chamber first wall.

  1. Surgical techniques for lumbo-sacral fusion.

    PubMed

    Tropiano, P; Giorgi, H; Faure, A; Blondel, B

    2017-02-01

    Lumbo-sacral (L5-S1) fusion is a widely performed procedure that has become the reference standard treatment for refractory low back pain. L5-S1 is a complex transition zone between the mobile lordotic distal lumbar spine and the fixed sacral region. The goal is to immobilise the lumbo-sacral junction in order to relieve pain originating from this site. Apart from achieving inter-vertebral fusion, the main challenge lies in the preoperative determination of the fixed L5-S1 position that will be optimal for the patient. Many lumbo-sacral fusion techniques are available. Stabilisation can be achieved using various methods. An anterior, posterior, or combined approach may be used. Recently developed minimally invasive techniques are gaining in popularity based on their good clinical outcomes and high fusion rates. The objective of this conference is to resolve the main issues faced by spinal surgeons in their everyday practice.

  2. Review of fusion synfuels

    SciTech Connect

    Fillo, J.A.

    1980-01-01

    Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  3. Nuclear Photonics for the 21st Century

    SciTech Connect

    Barty, Christopher P.J.

    2015-03-10

    Lasers and laser-based sources are now routinely used to control and manipulate nuclear processes, e.g. fusion, fission and resonant nuclear excitation. Two such “nuclear photonics” activities with the potential for profound societal impact will be reviewed in this presentation: the pursuit of laser-driven inertial confinement fusion at the National Ignition Facility and the development of laser-based, mono-energetic gamma-rays for isotope-specific detection, assay and imaging of materials.

  4. Fusion heating technology

    SciTech Connect

    Cole, A.J.

    1982-06-01

    John Lawson established the criterion that in order to produce more energy from fusion than is necessary to heat the plasma and replenish the radiation losses, a minimum value for both the product of plasma density and confinement time t, and the temperature must be achieved. There are two types of plasma heating: neutral beam and electromagnetic wave heating. A neutral beam system is shown. Main development work on negative ion beamlines has focused on the difficult problem of the production of high current sources. The development of a 30 keV-1 ampere multisecond source module is close to being accomplished. In electromagnetic heating, the launcher, which provides the means of coupling the power to the plasma, is most important. The status of heating development is reviewed. Electron cyclotron resonance heating (ECRH), lower hybrid heating (HHH), and ion cyclotron resonance heating (ICRH) are reviewed.

  5. Final report on the Magnetized Target Fusion Collaboration

    SciTech Connect

    John Slough

    2009-09-08

    Nuclear fusion has the potential to satisfy the prodigious power that the world will demand in the future, but it has yet to be harnessed as a practical energy source. The entry of fusion as a viable, competitive source of power has been stymied by the challenge of finding an economical way to provide for the confinement and heating of the plasma fuel. It is the contention here that a simpler path to fusion can be achieved by creating fusion conditions in a different regime at small scale (~ a few cm). One such program now under study, referred to as Magnetized Target Fusion (MTF), is directed at obtaining fusion in this high energy density regime by rapidly compressing a compact toroidal plasmoid commonly referred to as a Field Reversed Configuration (FRC). To make fusion practical at this smaller scale, an efficient method for compressing the FRC to fusion gain conditions is required. In one variant of MTF a conducting metal shell is imploded electrically. This radially compresses and heats the FRC plasmoid to fusion conditions. The closed magnetic field in the target plasmoid suppresses the thermal transport to the confining shell, thus lowering the imploding power needed to compress the target. The undertaking to be described in this proposal is to provide a suitable target FRC, as well as a simple and robust method for inserting and stopping the FRC within the imploding liner. The timescale for testing and development can be rapidly accelerated by taking advantage of a new facility funded by the Department of Energy. At this facility, two inductive plasma accelerators (IPA) were constructed and tested. Recent experiments with these IPAs have demonstrated the ability to rapidly form, accelerate and merge two hypervelocity FRCs into a compression chamber. The resultant FRC that was formed was hot (T&ion ~ 400 eV), stationary, and stable with a configuration lifetime several times that necessary for the MTF liner experiments. The accelerator length was less than

  6. Lessons Learned from ASCI applied to the Fusion Simulation Project (FSP)

    NASA Astrophysics Data System (ADS)

    Post, Douglass

    2003-10-01

    The magnetic fusion program has proposed a 20M dollar per year project to develop a computational predictive capability for magnetic fusion experiments. The DOE NNSA launched a program in 1996, the Accelerated Strategic Computing Initiative (ASCI) to achieve the same goal for nuclear weapons to allow certification of the stockpile without testing. We present a "lessons learned" analysis of the 3B dollary 7 year ASCI program with the goal of improving the FSP to maximize the likelihood of success. The major lessons from ASCI are: 1. Build on your institution's successful history; 2.Teams are the key element; 3. Sound Software Project Management is essential: 4. Requirements, schedule and resources must be consistent; 5. Practices, not processes, are important; 6. Minimize and mitigate risks; 7. Minimize the computer science research aspect and maximize the physics elements; and 8. Verification and Validation are essential. We map this experience and recommendations into the FSP.

  7. Nuclear phenomena in low-energy nuclear reaction research.

    PubMed

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  8. Trends in fusion reactor safety research

    SciTech Connect

    Herring, J.S.; Holland, D.F.; Piet, S.J.

    1991-01-01

    Fusion has the potential to be an attractive energy source. From the safety and environmental perspective, fusion must avoid concerns about catastrophic accidents and unsolvable waste disposal. In addition, fusion must achieve an acceptable level of risk from operational accidents that result in public exposure and economic loss. Finally, fusion reactors must control routine radioactive effluent, particularly tritium. Major progress in achieving this potential rests on development of low-activation materials or alternative fuels. The safety and performance of various material choices and fuels for commercial fusion reactors can be investigated relatively inexpensively through reactor design studies. These studies bring together experts in a wide range of backgrounds and force the group to either agree on a reactor design or identify areas for further study. Fusion reactors will be complex with distributed radioactive inventories. The next generation of experiments will be critical in demonstrating that acceptable levels of safe operation can be achieved. These machines will use materials which are available today and for which a large database exists (e.g. for 316 stainless steel). Researchers have developed a good understanding of the risks associated with operation of these devices. Specifically, consequences from coolant system failures, loss of vacuum events, tritium releases, and liquid metal reactions have been studied. Recent studies go beyond next step designs and investigate commercial reactor concerns including tritium release and liquid metal reactions. 18 refs.

  9. On the path to fusion energy

    NASA Astrophysics Data System (ADS)

    Tabak, M.

    2006-06-01

    There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls, et al., leads to reactors compatible with civilian power production. Methods to achieve the good control of hydrodynamic stability (adiabat shaping) and implosion symmetry required to achieve these high fuel densities will be discussed. Examples of symmetry control for targets driven by Z-pinches or heavy ion beams are given. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described. If these innovations are successful, the fusion specific capital costs can be reduced below 10% of the balance of plant.

  10. Viral membrane fusion.

    PubMed

    Harrison, Stephen C

    2015-05-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.

  11. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C.

    2015-01-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. PMID:25866377

  12. Interpretation and Visualization of Non-Linear Data Fusion in Kernel Space: Study on Metabolomic Characterization of Progression of Multiple Sclerosis

    PubMed Central

    Smolinska, Agnieszka; Blanchet, Lionel; Coulier, Leon; Ampt, Kirsten A. M.; Luider, Theo; Hintzen, Rogier Q.; Wijmenga, Sybren S.; Buydens, Lutgarde M. C.

    2012-01-01

    Background In the last decade data fusion has become widespread in the field of metabolomics. Linear data fusion is performed most commonly. However, many data display non-linear parameter dependences. The linear methods are bound to fail in such situations. We used proton Nuclear Magnetic Resonance and Gas Chromatography-Mass Spectrometry, two well established techniques, to generate metabolic profiles of Cerebrospinal fluid of Multiple Sclerosis (MScl) individuals. These datasets represent non-linearly separable groups. Thus, to extract relevant information and to combine them a special framework for data fusion is required. Methodology The main aim is to demonstrate a novel approach for data fusion for classification; the approach is applied to metabolomics datasets coming from patients suffering from MScl at a different stage of the disease. The approach involves data fusion in kernel space and consists of four main steps. The first one is to extract the significant information per data source using Support Vector Machine Recursive Feature Elimination. This method allows one to select a set of relevant variables. In the next step the optimized kernel matrices are merged by linear combination. In step 3 the merged datasets are analyzed with a classification technique, namely Kernel Partial Least Square Discriminant Analysis. In the final step, the variables in kernel space are visualized and their significance established. Conclusions We find that fusion in kernel space allows for efficient and reliable discrimination of classes (MScl and early stage). This data fusion approach achieves better class prediction accuracy than analysis of individual datasets and the commonly used mid-level fusion. The prediction accuracy on an independent test set (8 samples) reaches 100%. Additionally, the classification model obtained on fused kernels is simpler in terms of complexity, i.e. just one latent variable was sufficient. Finally, visualization of variables importance in

  13. Fusion probability in heavy nuclei

    NASA Astrophysics Data System (ADS)

    Banerjee, Tathagata; Nath, S.; Pal, Santanu

    2015-03-01

    Background: Fusion between two massive nuclei is a very complex process and is characterized by three stages: (a) capture inside the potential barrier, (b) formation of an equilibrated compound nucleus (CN), and (c) statistical decay of the CN leading to a cold evaporation residue (ER) or fission. The second stage is the least understood of the three and is the most crucial in predicting yield of superheavy elements (SHE) formed in complete fusion reactions. Purpose: A systematic study of average fusion probability, , is undertaken to obtain a better understanding of its dependence on various reaction parameters. The study may also help to clearly demarcate onset of non-CN fission (NCNF), which causes fusion probability, PCN, to deviate from unity. Method: ER excitation functions for 52 reactions leading to CN in the mass region 170-220, which are available in the literature, have been compared with statistical model (SM) calculations. Capture cross sections have been obtained from a coupled-channels code. In the SM, shell corrections in both the level density and the fission barrier have been included. for these reactions has been extracted by comparing experimental and theoretical ER excitation functions in the energy range ˜5 %-35% above the potential barrier, where known effects of nuclear structure are insignificant. Results: has been shown to vary with entrance channel mass asymmetry, η (or charge product, ZpZt ), as well as with fissility of the CN, χCN. No parameter has been found to be adequate as a single scaling variable to determine . Approximate boundaries have been obtained from where starts deviating from unity. Conclusions: This study quite clearly reveals the limits of applicability of the SM in interpreting experimental observables from fusion reactions involving two massive nuclei. Deviation of from unity marks the beginning of the domain of dynamical models of fusion. Availability of precise ER cross

  14. Production and measurement of engineered surfaces for inertial confinement fusion research

    SciTech Connect

    Day, Robert D; Hatch, Douglas J; Rivera, Gerald

    2011-01-19

    Inertial Confinement Fusion uses the optical energy from a very high power laser to implode spherical capsules that contain a fuel mixture of deuterium and tritium. The capsules are made of either Beryllium, plastic, or glass and range from 0.1 mm to 2 mm in diameter. As a capsule implodes, thereby compressing the fuel to reach nuclear fusion conditions, it achieves temperatures of millions of degrees Centigrade and very high pressures. In this state, the capsule materials act like fluids and often a low density fluidic material will push on a higher density material which can be a very unstable condition depending upon the smoothness of the interface between the two materials. This unstable condition is called a hydrodynamic instabillity which results in the mixing of the two materials. If the mixing occurs between the fuel and a non-fuel material, it can stop the fusion reaction just like adding significant amounts of water to gasoline can stop the operation of an automobile. Another region in the capsule where surface roughness can cause capsule performance degradation is at a joint. For instance, many capsules are made of hemispheres that are joined together. If the joint surfaces are too rough, then there will an effective reduction in density at the joint. This density reduction can cause a non-uniform implosion which will reduce the fusion energy coming out of the capsule.

  15. Cold fusion research

    SciTech Connect

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  16. Dynamical effects in fusion with exotic nuclei

    NASA Astrophysics Data System (ADS)

    Vo-Phuoc, K.; Simenel, C.; Simpson, E. C.

    2016-08-01

    Background: Reactions with stable beams have demonstrated strong interplay between nuclear structure and fusion. Exotic beam facilities open new perspectives to understand the impact of neutron skin, large isospin, and weak binding energies on fusion. Microscopic theories of fusion are required to guide future experiments. Purpose: To investigate new effects of exotic structures and dynamics in near-barrier fusion with exotic nuclei. Method: Microscopic approaches based on the Hartree-Fock (HF) mean-field theory are used for studying fusion barriers in -54Ca40+116Sn reactions for even isotopes. Bare potential barriers are obtained assuming frozen HF ground-state densities. Dynamical effects on the barrier are accounted for in time-dependent Hartree-Fock (TDHF) calculations of the collisions. Vibrational couplings are studied in the coupled-channel framework and near-barrier nucleon transfer is investigated with TDHF calculations. Results: The development of a neutron skin in exotic calcium isotopes strongly lowers the bare potential barrier. However, this static effect is not apparent when dynamical effects are included. On the contrary, a fusion hindrance is observed in TDHF calculations with the most neutron-rich calcium isotopes which cannot be explained by vibrational couplings. Transfer reactions are also important in these systems due to charge equilibration processes. Conclusions: Despite its impact on the bare potential, the neutron skin is not seen as playing an important role in the fusion dynamics. However, the charge transfer with exotic projectiles could lead to an increase of the Coulomb repulsion between the fragments, suppressing fusion. The effects of transfer and dissipative mechanisms on fusion with exotic nuclei deserve further studies.

  17. The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine

    SciTech Connect

    Farmer, J C; Diaz de la Rubia, T; Moses, E

    2008-12-23

    The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission blanket in a fusion

  18. Current Status and Recent Research Achievements in SiC/SiC Composites

    SciTech Connect

    Katoh, Yutai; Snead, Lance L.; Henager, Charles H.; Nozawa, T.; Hinoki, Tetsuya; Ivekovic, Aljaz; Novak, Sasa; Gonzalez de Vicente, Sehila M.

    2014-12-01

    The development and maturation of the silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) composite system for fusion applications has seen the evolution from fundamental development and understanding of the material system and its behavior in a hostile irradiation environment to the current effort which essentially is a broad-based program of technology, directed at moving this material class from a laboratory curiosity to an engineering material. This paper lays out the recent international scientific and technological achievements in the development of SiC/SiC composite material technologies for fusion application and will discuss future research directions. It also reviews the materials system in the larger context of progress to maturity as an engineering material for both the larger nuclear community and for general engineering applications.

  19. Spatial Regulation of Membrane Fusion Controlled by Modification of Phosphoinositides

    PubMed Central

    Dumas, Fabrice; Byrne, Richard D.; Vincent, Ben; Hobday, Tina M. C.; Poccia, Dominic L.; Larijani, Banafshé

    2010-01-01

    Membrane fusion plays a central role in many cell processes from vesicular transport to nuclear envelope reconstitution at mitosis but the mechanisms that underlie fusion of natural membranes are not well understood. Studies with synthetic membranes and theoretical considerations indicate that accumulation of lipids characterised by negative curvature such as diacylglycerol (DAG) facilitate fusion. However, the specific role of lipids in membrane fusion of natural membranes is not well established. Nuclear envelope (NE) assembly was used as a model for membrane fusion. A natural membrane population highly enriched in the enzyme and substrate needed to produce DAG has been isolated and is required for fusions leading to nuclear envelope formation, although it contributes only a small amount of the membrane eventually incorporated into the NE. It was postulated to initiate and regulate membrane fusion. Here we use a multidisciplinary approach including subcellular membrane purification, fluorescence spectroscopy and Förster resonance energy transfer (FRET)/two-photon fluorescence lifetime imaging microscopy (FLIM) to demonstrate that initiation of vesicle fusion arises from two unique sites where these vesicles bind to chromatin. Fusion is subsequently propagated to the endoplasmic reticulum-derived membranes that make up the bulk of the NE to ultimately enclose the chromatin. We show how initiation of multiple vesicle fusions can be controlled by localised production of DAG and propagated bidirectionally. Phospholipase C (PLCγ), GTP hydrolysis and (phosphatidylinsositol-(4,5)-bisphosphate (PtdIns(4,5)P2) are required for the latter process. We discuss the general implications of membrane fusion regulation and spatial control utilising such a mechanism. PMID:20808914

  20. Status of cold fusion (2010).

    PubMed

    Storms, Edmund

    2010-10-01

    The phenomenon called cold fusion has been studied for the last 21 years since its discovery by Profs. Fleischmann and Pons in 1989. The discovery was met with considerable skepticism, but supporting evidence has accumulated, plausible theories have been suggested, and research is continuing in at least eight countries. This paper provides a brief overview of the major discoveries and some of the attempts at an explanation. The evidence supports the claim that a nuclear reaction between deuterons to produce helium can occur in special materials without application of high energy. This reaction is found to produce clean energy at potentially useful levels without the harmful byproducts normally associated with a nuclear process. Various requirements of a model are examined.

  1. Could Advanced Fusion Fuels Be Used with Today's Technology?

    NASA Astrophysics Data System (ADS)

    Santarius, J. F.; Kulcinski, G. L.; El-Guebaly, L. A.; Khater, H. Y.

    1998-03-01

    Could today's technology suffice for engineering advanced-fuel, magnetic-fusion power plants, thus making fusion development primarily a physics problem? Such a path would almost certainly cost far less than the present D-T development program, which is driven by daunting engineering challenges as well as physics questions. Advanced fusion fuels, in contrast to D-T fuel, produce a smaller fraction of the fusion power as neutrons but have lower fusion reactivity, leading to a trade-off between engineering and physics. This paper examines the critical fusion engineering issues and related technologies with an eye to their application in tokamak and alternate-concept D-3He power plants. These issues include plasma power balance, magnets, surface heat flux, input power, fuel source, radiation damage, radioactive waste disposal, and nuclear proliferation.

  2. Magnetized target fusion and fusion propulsion

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Ronald C.

    2002-01-01

    Magnetized target fusion (MTF) is a thermonuclear fusion concept that is intermediate between the two mainline approaches, magnetic confinement and inertial confinement fusion (MCF and ICF). MTF incorporates some aspects of each and offers advantages over each of the mainline approaches. First, it provides a means of reducing the driver power requirements, thereby admitting a wider range of drivers than ICF. Second, the magnetic field is only used for insulation, not confinement, and the plasma is wall confined, so that plasma instabilities are traded in for hydrodynamic instabilities. However, the degree of compression required to reach fusion condition is lower than for ICF, so that hydrodynamic instabilities are much less threatening. The standoff driver innovation proposes to dynamically form the target plasma and a gaseous shell that compresses and confines the target plasma. Therefore, fusion target fabrication is traded in for a multiplicity of plasma guns, which must work in synchrony. The standoff driver embodiment of MTF leads to a fusion propulsion system concept that is potentially compact and lightweight. We will discuss the underlying physics of MTF and some of the details of the fusion propulsion concept using the standoff driver approach. We discuss here the optimization of an MTF target design for space propulsion. .

  3. Fusion research: the past is prologue

    SciTech Connect

    Post, R F

    1998-10-14

    At this juncture fusion research can be viewed as being at a turning point, a time to review its past and to imagine its future. Today, almost 50 years since the first serious attempts to address the daunting problem of achieving controlled fusion, we have both an opportunity and a challenge. Some predictions place fusion research today at a point midway between its first inception and its eventual maturation - in the middle of the 21st century - when fusion would become a major source of energy. Our opportunity therefore is to assess what we have learned from 50 years of hard work and use that knowledge as a starting point for new and better approaches to solving the fusion problem. Our challenge is to prove the "50 more years" prophesy wrong, by finding ways to shorten the time when fusion power becomes a reality. The thesis will be advanced that in the magnetic confinement approach to fusion open-ended magnetic confinement geometries offer much in responding to the challenge. A major advantage of open systems is that, owing to their theoretically and experimentally demonstrated ability to suppress plasma instabilities of both the MHD and the high-frequency wave-particle variety, the confinement becomes predictable from "classical," i.e., Fokker-Planck-type analysis. In a time of straitened budgetary circumstances for magnetic fusion research now being faced in the United States, the theoretical tractability of mirror-based systems is a substantial asset. In pursuing this avenue it is also necessary to keep an open mind as to the forms that mirror-based fusion power plants might take. For example, one can look to the high-energy physics community for a possible model: This community has shown the feasibility of constructing large and complex particle accelerators using superconducting magnets, vacuum chambers and complicated particle-handling technology, housed in underground tunnels that are 20 or more kilometers long. In the paper examples of mirror

  4. A review of pulse fusion propulsion

    NASA Astrophysics Data System (ADS)

    Cassenti, Brice N.

    2002-01-01

    During the last forty years there has been considerable interest in both internal and external pulse propulsion systems. Over this time the nuclear devices being considered have grown considerably smaller than those initially examined. Now pellets are normally in the range from 15 cm down to 2 cm in diameter, and fusion devices are generally preferred. High energy density triggers (such as lasers, particle beams or antiprotons) have been considered for detonating the fusion fuel. When antiprotons are considered it is more efficient to annihilate the antiprotons in a fissionable material, and then use the energy from the fission reaction to drive the fusion reaction in the pellet, than to use the annihilation energy directly. Finally, fissionable material can be used to boost the performance of a fusion system. The early concepts, which used critical mass devices, do not satisfy the ban on nuclear weapons in space, and are only rarely considered today. Concepts based on inertial confinement fusion are heavier than those that use antiprotons for the trigger since the mass associated with the lasers, or particle beams and their power supplies are considerably heavier than the traps used for antiprotons. Hence, from a performance, and even a political, point of view the antiproton-triggered approach is the most desirable, but it also requires more development. Not only is the trigger lighter but an external pulse propulsion rocket does not necessarily need radiators to reject excess heat and, hence, can be even lighter. Propulsion systems based on critical mass devices are clearly feasible, so the primary problem is to reduce the size of the explosive devices so that a critical mass is not required. If pulse nuclear fusion propulsion can become a reality then the performance is enough to complete manned missions to the inner planets in weeks and the outer planets in months. .

  5. Scientific and technological advancements in inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Hinkel, D. E.

    2013-10-01

    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. This synergy is summarized here, and future scientific studies are detailed.

  6. 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.

  7. Scientific and technological advancements in inertial fusion energy

    DOE PAGES

    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

  8. Viral membrane fusion

    SciTech Connect

    Harrison, Stephen C.

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

  9. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). This device would operate at much higher plasma densities and with much larger LD ratios than previous mirror machines. Several advantages accrue from such a design. First, the high LA:) ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. Second, the high plasma density will result in the plasma behaving much more Re a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. An experimental GDM device is currently being constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. Initial experiments are expected to commence in the late fall of 2000.

  10. Macron Formed Liner Compression as a Practical Method for Enabling Magneto-Inertial Fusion

    SciTech Connect

    Slough, John

    2011-12-10

    The entry of fusion as a viable, competitive source of power has been stymied by the challenge of finding an economical way to provide for the confinement and heating of the plasma fuel. The main impediment for current nuclear fusion concepts is the complexity and large mass associated with the confinement systems. To take advantage of the smaller scale, higher density regime of magnetic fusion, an efficient method for achieving the compressional heating required to reach fusion gain conditions must be found. The very compact, high energy density plasmoid commonly referred to as a Field Reversed Configuration (FRC) provides for an ideal target for this purpose. To make fusion with the FRC practical, an efficient method for repetitively compressing the FRC to fusion gain conditions is required. A novel approach to be explored in this endeavor is to remotely launch a converging array of small macro-particles (macrons) that merge and form a more massive liner inside the reactor which then radially compresses and heats the FRC plasmoid to fusion conditions. The closed magnetic field in the target FRC plasmoid suppresses the thermal transport to the confining liner significantly lowering the imploding power needed to compress the target. With the momentum flux being delivered by an assemblage of low mass, but high velocity macrons, many of the difficulties encountered with the liner implosion power technology are eliminated. The undertaking to be described in this proposal is to evaluate the feasibility achieving fusion conditions from this simple and low cost approach to fusion. During phase I the design and testing of the key components for the creation of the macron formed liner have been successfully carried out. Detailed numerical calculations of the merging, formation and radial implosion of the Macron Formed Liner (MFL) were also performed. The phase II effort will focus on an experimental demonstration of the macron launcher at full power, and the demonstration

  11. American Nuclear Society 1994 student conference eastern region

    SciTech Connect

    1994-12-31

    This report contains abstracts from the 1994 American Nuclear Society Student Conference. The areas covered by these abstracts are: fusion and plasma physics; nuclear chemistry; radiation detection; reactor physics; thermal hydraulics; and corrosion science and waste issues.

  12. A,B,C`s of nuclear science

    SciTech Connect

    Noto, V.A.; Norman, E.B.; Chan, Yuen-Dat; Dairiki, J.; Matis, H.S.; McMahan, M.A.; Otto, R.

    1995-08-07

    This introductory level presentation contains information on nuclear structure, radioactivity, alpha decay, beta decay, gamma decay, half-life, nuclear reactions, fusion, fission, cosmic rays, and radiation protection. Nine experiments with procedures and test questions are included.

  13. Nuclear Chemistry: Include It in Your Curriculum.

    ERIC Educational Resources Information Center

    Atwood, Charles H.; Sheline, R. K.

    1989-01-01

    Some of the topics that might be included in a nuclear chemistry section are explored. Offers radioactivity, closed shells in nuclei, energy of nuclear processes, nuclear reactions, and fission and fusion as topics of interest. Provided are ideas and examples for each. (MVL)

  14. Nuclear technology for the year 2000

    SciTech Connect

    Not Available

    1987-01-01

    Eighteen papers and abstracts are presented under the following session headings: space nuclear power, health physics and dosimetry, nuclear design and thermal hydraulics, nuclear diagnostics, and fusion technology and plasma physics. The papers were processed separately for the data base. (DLC)

  15. History of Nuclear India

    NASA Astrophysics Data System (ADS)

    Chaturvedi, Ram

    2000-04-01

    India emerged as a free and democratic country in 1947, and entered into the nuclear age in 1948 by establishing the Atomic Energy Commission (AEC), with Homi Bhabha as the chairman. Later on the Department of Atomic Energy (DAE) was created under the Office of the Prime Minister Jawahar Lal Nehru. Initially the AEC and DAE received international cooperation, and by 1963 India had two research reactors and four nuclear power reactors. In spite of the humiliating defeat in the border war by China in 1962 and China's nuclear testing in 1964, India continued to adhere to the peaceful uses of nuclear energy. On May 18, 1974 India performed a 15 kt Peaceful Nuclear Explosion (PNE). The western powers considered it nuclear weapons proliferation and cut off all financial and technical help, even for the production of nuclear power. However, India used existing infrastructure to build nuclear power reactors and exploded both fission and fusion devices on May 11 and 13, 1998. The international community viewed the later activity as a serious road block for the Non-Proliferation Treaty and the Comprehensive Test Ban Treaty; both deemed essential to stop the spread of nuclear weapons. India considers these treaties favoring nuclear states and is prepared to sign if genuine nuclear disarmament is included as an integral part of these treaties.

  16. Endoscopic Accessory Navicular Synchondrosis Fusion.

    PubMed

    Lui, Tun Hing

    2016-12-01

    The accessory navicular bone is one of the most common accessory ossicles of the foot. Fewer than 1% of accessory navicular bones are symptomatic, and most of these are type II accessory navicular bones. A separation of the synchondrosis is considered one of the main causes of pain. After an injury to the synchondrosis has resulted in a chondro-osseous disruption, the combined forces of tension and shear from the posterior tibial tendon and the foot aggravate the injury and prevent it from healing. Fusion of the synchondrosis is a logical surgical treatment option if the pain is recalcitrant to conservative measures. The purpose of this technical note is to report an endoscopic approach to achieve fusion. It has the advantages of better cosmesis, less scar pain, less risk of nonunion, and potential to examine the tibialis posterior tendon and the talonavicular joint.

  17. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  18. On the path to fusion energy

    NASA Astrophysics Data System (ADS)

    Tabak, M.

    2016-10-01

    There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls et al. leads reaction chambers compatible with civilian power production. Methods to achieve the good control of hydrodynamic stability and implosion symmetry required to achieve these high fuel densities will be discussed. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described.

  19. Graphite for the nuclear industry

    SciTech Connect

    Burchell, T.D.; Fuller, E.L.; Romanoski, G.R.; Strizak, J.P.

    1991-01-01

    Graphite finds applications in both fission and fusion reactors. Fission reactors harness the energy liberated when heavy elements, such as uranium or plutonium, fragment or fission''. Reactors of this type have existed for nearly 50 years. The first nuclear fission reactor, Chicago Pile No. 1, was constructed of graphite under a football stand at Stagg Field, University of Chicago. Fusion energy devices will produce power by utilizing the energy produced when isotopes of the element hydrogen are fused together to form helium, the same reaction that powers our sun. The role of graphite is very different in these two reactor systems. Here we summarize the function of the graphite in fission and fusion reactors, detailing the reasons for their selection and discussing some of the challenges associated with their application in nuclear fission and fusion reactors. 10 refs., 15 figs., 1 tab.

  20. Review of new developments in fusion reactor nucleonics

    SciTech Connect

    Dudziak, D.J.; Young, P.G.

    1980-01-01

    A review is presented of recent developments in nuclear data, computational methods, and computer codes, especially as pertains to fusion reactor nucleonics. Important nuclear data measurements, evaluations, nuclear model codes and processing codes are discussed. Progress in solution acceleration and deterministic streaming methods for discrete-ordinates codes is covered, along with comments on recent Monte Carlo developments. Finally, sensitivity and uncertainty analysis methods are reviewed.

  1. Thermonuclear Fusion: An Energy Source for the Future

    ERIC Educational Resources Information Center

    Drummond, William E.

    1973-01-01

    Discusses current research in thermonuclear fusion with particular emphasis on the problem of confining hot plasma. Recent experiments indicate that magnetic bottles called tokamaks may achieve the necessary confinement times, and this break-through has given renewed optimism to the feasibility of commercial fusion power by the turn of the…

  2. Fission or fusion for Mars missions. Expectations and challenges

    NASA Astrophysics Data System (ADS)

    Kammash, Terry

    A fission based system in the form of the Gas Core Nuclear Rocket (GCR) and a laser-driven inertial fusion system that utilizes a self-generated magnetic field (MICF) are compared as potential propulsion systems for manned planetary travel. The first generates thrust by a hydrogen propellant that is heated by radiation emitted from a critical reactor with a uranium fuel in plasma form, to take advantage of high achievable temperatures. The fusion system produces attractive propulsion characteristics through energy magnification of a hot hydrogenous plasma which is guided by a magnetic nozzle that allows thermal energy to be converted into thrust. Although both systems are capable of producing several thousand seconds of specific impulse, and tens to hundreds of kilonewtons of thrust, each faces some formidable physics and engineering problems that must be addressed if they are to become viable propulsion systems. With the aid of an appropriate set of fluid and plasma equations, we assess the dynamics of each system and identify those issues that could detract from their performance. In the case of GCR, thermal hydraulic considerations reveal deterioration of propulsive capability when wall heat flux limitations and turbulent mixing are taken into account. Moreover, hydrodynamics and acoustic instabilities could also adversely affect its performance, although they may be amenable to stabilization by magnetic fields. For MICF, large energy multiplication at modest input laser energies appears to be a major concern, but if anti-hydrogen can be used to initiate the fusion reactions, this concept can be truly an outstanding propulsion device.

  3. Acoustically Driven Magnetized Target Fusion At General Fusion: An Overview

    NASA Astrophysics Data System (ADS)

    O'Shea, Peter; Laberge, M.; Donaldson, M.; Delage, M.; the Fusion Team, General

    2016-10-01

    Magnetized Target Fusion (MTF) involves compressing an initial magnetically confined plasma of about 1e23 m-3, 100eV, 7 Tesla, 20 cm radius, >100 μsec life with a 1000x volume compression in 100 microseconds. If near adiabatic compression is achieved, the final plasma of 1e26 m-3, 10keV, 700 Tesla, 2 cm radius, confined for 10 μsec would produce interesting fusion energy gain. General Fusion (GF) is developing an acoustic compression system using pneumatic pistons focusing a shock wave on the CT plasma in the center of a 3 m diameter sphere filled with liquid lead-lithium. Low cost driver, straightforward heat extraction, good tritium breeding ratio and excellent neutron protection could lead to a practical power plant. GF (65 employees) has an active plasma R&D program including both full scale and reduced scale plasma experiments and simulation of both. Although acoustic driven compression of full scale plasmas is the end goal, present compression studies use reduced scale plasmas and chemically accelerated Aluminum liners. We will review results from our plasma target development, motivate and review the results of dynamic compression field tests and briefly describe the work to date on the acoustic driver front.

  4. The Quest for Fusion at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Hartouni, Edward

    2017-01-01

    Arthur Eddington speculated in 1920 on the internal constitution of stars and described the possibility of nuclear fusion based on the then new results from special relativity and measurements of light nuclei masses. By 1929 Atkinson and Houtermans worked out the calculations for nuclear fusion in stars and initiating nuclear astrophysics. All of these sciences were pressed into service during the World War II, and the applications developed, particularly under the auspices of the Manhattan Project provided both weapons with which to wage and win that conflict, but also the possibilities to harness these applications of the nuclear processes of fission and fusion for peaceful purposes. 32 years after Eddington's speculation the United States demonstrated the application of fusion in a famous nuclear weapons test. In the following years many ideas for producing ``controlled'' fusion through inertial confinement were pursued. The invention of the laser opened up new avenues which have culminated in the National Ignition Facility, NIF. I will attempt to cover the ground between Eddington, through the Manhattan Project and provide a current status of this quest at NIF. LLNL-ABS-704367-DRAFT. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  5. Magnetic fusion reactor economics

    SciTech Connect

    Krakowski, R.A.

    1995-12-01

    An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant.

  6. Safeguard Requirements for Fusion Power Plants

    SciTech Connect

    Robert J. Goldston and Alexander Glaser

    2012-08-10

    Nuclear proliferation risks from magnetic fusion energy associated with access to fissile materials can be divided into three main categories: 1) clandestine production of fissile material in an undeclared facility, 2) covert production and diversion of such material in a declared and safeguarded facility, and 3) use of a declared facility in a breakout scenario, in which a state openly produces fissile material in violation of international agreements. The degree of risk in each of these categories is assessed, taking into account both state and non-state actors, and it is found that safeguards are required for fusion energy to be highly attractive from a non-proliferation standpoint. Specific safeguard requirements and R&D needs are outlined for each category of risk, and the technical capability of the ITER experiment, under construction, to contribute to this R&D is noted. A preliminary analysis indicates a potential legal pathway for fusion power systems to be brought under the Treaty for the Non-Proliferation of Nuclear Weapons. "Vertical" proliferation risks associated with tritium and with the knowledge that can be gained from inertial fusion energy R&D are outlined.

  7. Reprogramming of Somatic Cells Towards Pluripotency by Cell Fusion.

    PubMed

    Malinowski, Andrzej R; Fisher, Amanda G

    2016-01-01

    Pluripotent reprogramming can be dominantly induced in a somatic nucleus upon fusion with a pluripotent cell such as embryonic stem (ES) cell. Cell fusion between ES cells and somatic cells results in the formation of heterokaryons, in which the somatic nuclei begin to acquire features of the pluripotent partner. The generation of interspecies heterokaryons between mouse ES- and human somatic cells allows an experimenter to distinguish the nuclear events occurring specifically within the reprogrammed nucleus. Therefore, cell fusion provides a simple and rapid approach to look at the early nuclear events underlying pluripotent reprogramming. Here, we describe a polyethylene glycol (PEG)-mediated cell fusion protocol to generate interspecies heterokaryons and intraspecies hybrids between ES cells and B lymphocytes or fibroblasts.

  8. 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.

  9. Fusion cross sections and the new dynamics

    SciTech Connect

    Swiatecki, W.J.

    1981-05-01

    The prediction of the need for an extra push over the interaction barrier in order to make the heavier nuclei fuse is made the basis of a simple algebraic theory for the energy-dependence of the fusion cross-section. A comparison with recent experiments promises to provide a quantitative test of the New Dynamics (the theory of macroscopic nuclear shape evolutions based on the one-body dissipation concept).

  10. Measurements of fusion cross sections in the systems {sup 58,64}Ni +, {sup 78,86}Kr

    SciTech Connect

    Rehm, K.E.; Jiang, C.L.; Esbensen, H.

    1995-08-01

    We investigated the nuclear structure dependence of the sub-barrier fusion enhancement in heavy-ion induced reactions by studying the systems {sup 58,64}Ni + {sup 78,86}Kr at energies in the vicinity of the Coulomb barrier. These {sup 78,86}Kr selected because, similar to the Mo case discussed isotopes were above, there are strong changes in nuclear structure as a function of the neutron number. However, contrary to Mo, where the {open_quotes}softness{close_quotes} of the nucleus increases with higher neutron number, the most collective nucleus for the Kr case is the neutron-deficient {sup 78}Kr. The experiment was performed with Kr beams from the positive-ion injector using enriched {sup 78,86}Kr gas in the ECR ion source. The separation of evaporation residues from the elastically-scattered particles was achieved by using their difference in time-of-flight and magnetic rigidity in the gas-filled spectrograph. The excitation functions for the four systems were compared to coupled-channels calculations including inelastic excitations of one- and two-phonon states in projectile and target. For systems involving {sup 86}Kr, good agreement between theory and experiment is obtained, while for {sup 78}Kr + {sup 58,64}Ni an additional enhancement of the cross sections persisted at the lowest energies. It was found that this fusion enhancement correlates with the nuclear structure of the individual nucleus. Characterizing the structure of vibrational even-even nuclei by their restoring force parameter C{sub 2}, which can be calculated from the energy of the lowest 2{sup +} state and the associated B(E2) value, one observes that nuclei with small C{sub 2} values exhibit a large sub-barrier fusion enhancement, while nuclei with high values of C{sub 2} (usually closed-shell nuclei), show smaller fusion yields.

  11. Fusion Science Education Outreach

    NASA Astrophysics Data System (ADS)

    Danielson, C. A.; DIII-D Education Group

    1996-11-01

    This presentation will focus on education outreach activities at General Atomics that have been expanded to include the general population on science education with a focus on fusion energy. Outreach materials are distributed upon request both nationally and internationally. These materials include a notebook containing copies of DIII--D tour panels, fusion poster, new fusion energy video, new fusion energy brochure, and the electromagnetic spectrum curriculum. The 1996 Fusion Forum (held in the House Caucus Room) included a student/ teacher lunch with Energy Secretary Hazel O'Leary and a private visit to the Forum exhibits. The continuing partnership with Kearny High School includes lectures, job shadowing, internship, equipment donations and an award-winning electric car-racing program. Development of distribution by CD of the existing interactive fusion energy kiosk and a virtual reality tour of the DIII--D facility are underway. The DIII--D fusion education WWW site includes e-mail addresses to ``Ask the Wizard,'' and/or receive GA's outreach materials. Steve Rodecker, a local science teacher, aided by DIII--D fusion staff, won his second Tapestry Award; he also was named the ``1995 National Science Teacher of the Year'' and will be present to share his experiences with the DIII--D educational outreach program.

  12. Two Horizons of Fusion

    ERIC Educational Resources Information Center

    Lo, Mun Ling; Chik, Pakey Pui Man

    2016-01-01

    In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

  13. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment.

  14. Integrated systems for pulsed-power driven inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Cuneo, M. E.; Slutz, S. A.; Stygar, W. A.; Herrmann, M. C.; Sinars, D. B.; McBride, R. D.; Vesey, R. A.; Sefkow, A. B.; Mazarakis, M. G.; Vandevender, J. P.; Waisman, E. M.; Hansen, D. L.; Owen, A. C.; Jones, J. F.; Romero, J. A.; McKenney, J.

    2011-10-01

    Pulsed power fusion concepts integrate: (i) directly-magnetically-driven fusion targets that absorb large energies (10 MJ), (ii) efficient, rep-rated driver modules, (iii) compact, scalable, integrated driver architectures, (iv) driver-to-target coupling techniques with standoff and driver protection, and (v) long lifetime fusion chambers shielded by vaporizing blankets and thick liquid walls. Large fusion yields (3-30 GJ) and low rep-rates (0.1-1 Hz) may be an attractive path for IFE. Experiments on the ZR facility are validating physics issues for magnetically driven targets. Scientific breakeven (fusion energy = fuel energy) may be possible in the next few years. Plans for system development and integration will be discussed. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  16. Assessment of NDE Methods to Detect Lack of Fusion in HDPE Butt Fusion Joints

    SciTech Connect

    Crawford, Susan L.; Doctor, Steven R.; Cinson, Anthony D.; Watts, Michael W.; Moran, Traci L.; Anderson, Michael T.

    2011-07-31

    Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, were conducted to evaluate nondestructive examinations (NDE) coupled with mechanical testing of butt fusion joints in high-density polyethylene (HDPE) pipe for assessing lack of fusion. The work provided information to the United States Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques of HDPE butt fusion joints in Section III, Division 1, Class 3, buried piping systems in nuclear power plants. This paper describes results from assessments using ultrasonic and microwave nondestructive techniques and mechanical testing with the high-speed tensile impact test and the side-bend test for determining joint integrity. A series of butt joints were fabricated in 3408, 12-inch (30.5-cm) IPS DR-11 HDPE material by varying the fusion parameters to create good joints and joints containing a range of lack-of-fusion conditions. Six of these butt joints were volumetrically examined with time-of-flight diffraction (TOFD), phased-array (PA) ultrasound, and the Evisive microwave system. The outer diameter (OD) weld beads were removed for microwave evaluation and the pipes ultrasonically re-evaluated. In two of the six pipes, both the outer and inner diameter (ID) weld beads were removed and the pipe joints re-evaluated. Some of the pipes were sectioned and the joints destructively evaluated with the high-speed tensile test and the side-bend test. The fusion parameters, nondestructive and destructive evaluation results have been correlated to validate the effectiveness of what each NDE technology detects and what each does not detect. There was no single NDE method that detected all of the lack-of-fusion flaws but a combination of NDE methods did detect most of the flaws.

  17. Impact of Fast Ignition on Laser Fusion Energy Development

    NASA Astrophysics Data System (ADS)

    Mirna, Kunioki

    2016-10-01

    Reviewed are the early history of Japanese laser fusion research and the recent achievement of fast ignition research at Institute of Laser Engineering (ILE), Osaka University. After the achievement of high density compression at Osaka University, LLE of University Rochester, and LLNL, the critical issue of Inertial Fusion Energy (IFE) research became the formation of hot spark in a compressed plasma. In this lecture, the history of the fast ignition research will be reviewed and future prospects are presented.

  18. Solid-State Nuclear Magnetic Resonance Measurements of HIV Fusion Peptide 13CO to Lipid 31P Proximities Support Similar Partially Inserted Membrane Locations of the α Helical and β Sheet Peptide Structures

    NASA Astrophysics Data System (ADS)

    Gabrys, Charles M.; Qiang, Wei; Sun, Yan; Xie, Li; Schmick, Scott D.; Weliky, David P.

    2013-10-01

    Fusion of the human immunodeficiency virus (HIV) membrane and the host cell membrane is an initial step of infection of the host cell. Fusion is catalyzed by gp41, which is an integral membrane protein of HIV. The fusion peptide (FP) is the -25 N-terminal residues of gp41 and is a domain of gp41 that plays a key role in fusion catalysis likely through interaction with the host cell membrane. Much of our understanding of the FP domain has been accomplished with studies of -HFP-, i.e., a -25-residue peptide composed of the FP sequence but lacking the rest of gp41. HFP catalyzes fusion between membrane vesicles and serves as a model system to understand fusion catalysis. HFP binds to membranes and the membrane location of HFP is likely a significant determinant of fusion catalysis perhaps because the consequent membrane perturbation reduces the fusion activation energy. In the present study, many HFPs were synthesized and differed in the residue position that was 13CO backbone labeled. Samples were then prepared that each contained a singly 13CO labeled HFP incorporated into membranes that lacked cholesterol. HFP had distinct molecular populations with either α helical or oligomeric - sheet structure. Proximity between the HFP 13CO nuclei and 31P nuclei in the membrane headgroups was probed by solid-state NMR (SSNMR) rotational-echo double-resonance (REDOR) measurements. For many samples, there were distinct 13CO shifts for the α helical and - sheet structures so that the proximities to 31P nuclei could be determined for each structure. Data from several differently labeled HFPs were then incorporated into a membrane location model for the particular structure. In addition to the 13CO labeled residue position, the HFPs also differed in sequence and/or chemical structure. -HFPmn- was a linear peptide that contained the 23 N-terminal residues of gp41. -HFPmn_V2E- contained the V2E mutation that for HIV leads to greatly reduced extent of fusion and infection. The

  19. Solid-state nuclear magnetic resonance measurements of HIV fusion peptide 13CO to lipid 31P proximities support similar partially inserted membrane locations of the α helical and β sheet peptide structures.

    PubMed

    Gabrys, Charles M; Qiang, Wei; Sun, Yan; Xie, Li; Schmick, Scott D; Weliky, David P

    2013-10-03

    Fusion of the human immunodeficiency virus (HIV) membrane and the host cell membrane is an initial step of infection of the host cell. Fusion is catalyzed by gp41, which is an integral membrane protein of HIV. The fusion peptide (FP) is the ∼25 N-terminal residues of gp41 and is a domain of gp41 that plays a key role in fusion catalysis likely through interaction with the host cell membrane. Much of our understanding of the FP domain has been accomplished with studies of "HFP", i.e., a ∼25-residue peptide composed of the FP sequence but lacking the rest of gp41. HFP catalyzes fusion between membrane vesicles and serves as a model system to understand fusion catalysis. HFP binds to membranes and the membrane location of HFP is likely a significant determinant of fusion catalysis perhaps because the consequent membrane perturbation reduces the fusion activation energy. In the present study, many HFPs were synthesized and differed in the residue position that was (13)CO backbone labeled. Samples were then prepared that each contained a singly (13)CO labeled HFP incorporated into membranes that lacked cholesterol. HFP had distinct molecular populations with either α helical or oligomeric β sheet structure. Proximity between the HFP (13)CO nuclei and (31)P nuclei in the membrane headgroups was probed by solid-state NMR (SSNMR) rotational-echo double-resonance (REDOR) measurements. For many samples, there were distinct (13)CO shifts for the α helical and β sheet structures so that the proximities to (31)P nuclei could be determined for each structure. Data from several differently labeled HFPs were then incorporated into a membrane location model for the particular structure. In addition to the (13)CO labeled residue position, the HFPs also differed in sequence and/or chemical structure. "HFPmn" was a linear peptide that contained the 23 N-terminal residues of gp41. "HFPmn_V2E" contained the V2E mutation that for HIV leads to greatly reduced extent of fusion and

  20. Muon sticking factor in muon catalyzed fusion and the other aspect of this fusion process

    SciTech Connect

    Takahashi, H.

    1986-01-01

    The effect of resonance nuclear fusion reaction on the initial muon sticking factor is formulated. The analysis shows that it is very sensitive to the resonance parameter, and the factor calculated, using the molecular wave function obtained by the Diffusion Monte Carlo method, is 0.1 +- 0.01 for the presently evaluated resonance parameter. The analysis of the multistep excitation effect on the reactivation factor shows that the effect is not so large, and the analysis of muonic x-ray spectra of ..mu../sup 3/He from P..mu..d and d..mu..d fusions is in good agreement with the values measured by Bossy et al.

  1. [Metapneumovirus expands the understanding of Paramyxovirus cell fusion--a review].

    PubMed

    Liu, Xiaoyu; Zhang, Xiaodong; Wei, Yongwei

    2014-04-04

    For most viruses in Paramyxoviridae, cell fusion requires both attachment protein and fusion protein. The attachment protein is responsible for the binding to its cognate receptors, while the interaction between fusion protein and attachment protein triggers the fusion protein which is responsible for the fusion. However, the Metapneumovirus fusion in Pneumovirinae subfamily displayed different mechanism where the attachment protein is not required. The cell fusion is accomplished by fusion protein alone without the help of the attachment protein. Recent studies indicate that low pH is required for cell fusion promoted by some hMPV strains. The fusion protein of aMPV type A is highly fusogenic, whereas that of type B is low. The original fusion models for Paramyxovirus cannot explain the phenomenon above. The mechanism to regulate the cell fusion of Metapneumovirus is poorly understood. It is becoming a hot spot for the study of cell fusion triggered by Paramyxovirus where it enlarged the traditional scope of Paramyxovirus fusion. In this review, we discuss the new achievements and advances in the understanding of cell fusion triggered by Metapneumovirus.

  2. Accelerator and Fusion Research Division: summary of activities, 1983

    SciTech Connect

    Not Available

    1984-08-01

    The activities described in this summary of the Accelerator and Fusion Research Division are diverse, yet united by a common theme: it is our purpose to explore technologically advanced techniques for the production, acceleration, or transport of high-energy beams. These beams may be the heavy ions of interest in nuclear science, medical research, and heavy-ion inertial-confinement fusion; they may be beams of deuterium and hydrogen atoms, used to heat and confine plasmas in magnetic fusion experiments; they may be ultrahigh-energy protons for the next high-energy hadron collider; or they may be high-brilliance, highly coherent, picosecond pulses of synchrotron radiation.

  3. Cold fusion verification. Final report for period ending 1989

    SciTech Connect

    North, M.H.; Mastny, G.F.; Wesley, E.J.

    1991-03-01

    The objective of this work to verify and reproduce experimental observations of Cold Nuclear Fusion (CNF), as originally reported in 1989. The method was to start with the original report and add such additional information as became available to build a set of operational electrolytic CNF cells. Verification was to be achieved by first observing cells for neutron production, and for those cells that demonstrated a nuclear effect, careful calorimetric measurements were planned. The authors concluded, after laboratory experience, reading published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater. The neutron detector used for these tests was a completely packaged unit built into a metal suitcase that afforded electrostatic shielding for the detectors and self-contained electronics. It was battery-powered, although it was on charge for most of the long tests. The sensor element consists of He detectors arranged in three independent layers in a solid moderating block. The count from each of the three layers as well as the sum of all the detectors were brought out and recorded separately. The neutron measurements were made with both the neutron detector and the sample tested in a cave made of thick moderating material that surrounded the two units on the sides and bottom.

  4. 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.

  5. 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.

  6. Achieving "Fairness" in Data Fusion Performance Evaluation Development

    DTIC Science & Technology

    2006-04-30

    DF response resources to include: communications , countermeasures, collection, and target management plus user interfaces & responses "* DF system...data link MADL, SATCOM intelligence broadcast links, voice and data communications , messaging, GPS, integrated navigation, IRS, TACAN and other landing...tactical picture across platforms) > communications management (balance BW with mission communications needs) > threat and target response management

  7. Qubit-loss-free fusion of W states

    NASA Astrophysics Data System (ADS)

    Li, Ke; Kong, Fan-Zhen; Yang, Ming; Yang, Qing; Cao, Zhuo-Liang

    2016-12-01

    Fusion technique plays a key role in the preparation of large-scale W states, but the currently existing fusion schemes are suffering from the qubit loss problem, i.e., the number of the output entangled qubits is smaller than the sum of numbers of the input entangled qubits, which will inevitably decrease the fusion efficiency and increase the number of fusion steps as well as the requirement of quantum memories. In this paper, we design a fusion mechanism to fuse two small-size W states into a large-scale W state without qubit loss, and thus we call it qubit-loss-free (QLF) fusion mechanism. This QLF fusion mechanism is based on a two-outcome positive-operator valued measurement on two qubits extracting from two small-size W states, and works for both pure and mixed W states. The QLF nature of this fusion mechanism clearly increases the final size of the obtained W state, and greatly reduces the number of fusion steps as well as the requirement of quantum memories required to achieve a W state of a target size, so it is more efficient and feasible than the currently existing fusion schemes. There is no complete failure output in our QLF fusion scheme, and all the garbage states are recyclable. Two example schemes are proposed to realize this QLF fusion mechanism in a cavity quantum electrodynamics system and three-qubit Heisenberg XYZ model, respectively, which demonstrates the possibility of the physical realization of this QLF fusion mechanism.

  8. Fast Radiometry Guided Fusion of Disparity Images

    NASA Astrophysics Data System (ADS)

    Schmid, Stephan; Fritsch, Dieter

    2016-06-01

    Previous work on disparity map fusion has mostly focused on geometric or statistical properties of disparity maps. Since failure of stereo algorithms is often consistent in many frames of a scene, it cannot be detected by such methods. Instead, we propose to use radiometric information from the original camera images together with externally supplied camera pose information to detect mismatches. As radiometric information is local information, the computations in the proposed algorithm for disparity fusion can be decoupled and parallelized to a very large degree, which allows us to easily achieve real-time performance.

  9. Advanced nuclear propulsion technologies

    SciTech Connect

    Cassenti, B.N. )

    1991-01-01

    Advanced nuclear propulsion can take on several forms. Radioactive thrust sheets directly use the decay of radioactive nuclei to provide propulsion. The fissioning of nuclei has been extensively studied for propulsion both analytically and experimentally. Fusion has been analytically examined as a means of providing propulsion during the last few decades. In the last decade, serious attention has been given to the direct annihilation of matter. Each of these technologies is discussed in this paper with the greatest emphasis on antiproton annihilation propulsion.

  10. Materials issues in fusion reactors

    NASA Astrophysics Data System (ADS)

    Suri, A. K.; Krishnamurthy, N.; Batra, I. S.

    2010-02-01

    The world scientific community is presently engaged in one of the toughest technological tasks of the current century, namely, exploitation of nuclear fusion in a controlled manner for the benefit of mankind. Scientific feasibility of controlled fusion of the light elements in plasma under magnetic confinement has already been proven. International efforts in a coordinated and co-operative manner are presently being made to build ITER - the International Thermonuclear Experimental Reactor - to test, in this first step, the concept of 'Tokamak' for net fusion energy production. To exploit this new developing option of making energy available through the route of fusion, India too embarked on a robust fusion programme under which we now have a working tokamak - the Aditya and a steady state tokamak (SST-1), which is on the verge of functioning. The programme envisages further development in terms of making SST-2 followed by a DEMO and finally the fusion power reactor. Further, with the participation of India in the ITER program in 2005, and recent allocation of half - a - port in ITER for placing our Lead - Lithium Ceramic Breeder (LLCB) based Test Blanket Module (TBM), meant basically for breeding tritium and extracting high grade heat, the need to understand and address issues related to materials for these complex systems has become all the more necessary. Also, it is obvious that with increasing power from the SST stages to DEMO and further to PROTOTYPE, the increasing demands on performance of materials would necessitate discovery and development of new materials. Because of the 14.1 MeV neutrons that are generated in the D+T reaction exploited in a tokamak, the materials, especially those employed for the construction of the first wall, the diverter and the blanket segments, suffer crippling damage due to the high He/dpa ratios that result due to the high energy of the neutrons. To meet this challenge, the materials that need to be developed for the tokamaks

  11. Robust fusion with reliabilities weights

    NASA Astrophysics Data System (ADS)

    Grandin, Jean-Francois; Marques, Miguel

    2002-03-01

    The reliability is a value of the degree of trust in a given measurement. We analyze and compare: ML (Classical Maximum Likelihood), MLE (Maximum Likelihood weighted by Entropy), MLR (Maximum Likelihood weighted by Reliability), MLRE (Maximum Likelihood weighted by Reliability and Entropy), DS (Credibility Plausibility), DSR (DS weighted by reliabilities). The analysis is based on a model of a dynamical fusion process. It is composed of three sensors, which have each it's own discriminatory capacity, reliability rate, unknown bias and measurement noise. The knowledge of uncertainties is also severely corrupted, in order to analyze the robustness of the different fusion operators. Two sensor models are used: the first type of sensor is able to estimate the probability of each elementary hypothesis (probabilistic masses), the second type of sensor delivers masses on union of elementary hypotheses (DS masses). In the second case probabilistic reasoning leads to sharing the mass abusively between elementary hypotheses. Compared to the classical ML or DS which achieves just 50% of correct classification in some experiments, DSR, MLE, MLR and MLRE reveals very good performances on all experiments (more than 80% of correct classification rate). The experiment was performed with large variations of the reliability coefficients for each sensor (from 0 to 1), and with large variations on the knowledge of these coefficients (from 0 0.8). All four operators reveal good robustness, but the MLR reveals to be uniformly dominant on all the experiments in the Bayesian case and achieves the best mean performance under incomplete a priori information.

  12. SABR fusion-fission hybrid transmutation reactor design concept

    NASA Astrophysics Data System (ADS)

    Stacey, Weston

    2009-11-01

    A conceptual design has been developed for a sub-critical advanced burner reactor (SABR) consisting of i) a sodium cooled fast reactor fueled with the transuranics (TRU) from spent nuclear fuel, and ii) a D-T tokamak fusion neutron source based on ITER physics and technology. Subcritical operation enables more efficient transmutation fuel cycles in TRU fueled reactors (without compromising safety), which may be essential for significant reduction in high-level waste repository requirements. ITER will serve as the prototype for the fusion neutron source, which means SABRs could be implemented to help close the nuclear fuel cycle during the 2^nd quarter of the century.

  13. Spherical torus fusion reactor

    DOEpatents

    Martin Peng, Y.K.M.

    1985-10-03

    The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

  14. Nuclear Terrorism.

    SciTech Connect

    Hecker, Siegfried S.

    2001-01-01

    As pointed out by several speakers, the level of violence and destruction in terrorist attacks has increased significantly during the past decade. Fortunately, few have involved weapons of mass destruction, and none have achieved mass casualties. The Aum Shinrikyo release of lethal nerve agent, sarin, in the Tokyo subway on March 20, 1995 clearly broke new ground by crossing the threshold in attempting mass casualties with chemical weapons. However, of all weapons of mass destruction, nuclear weapons still represent the most frightening threat to humankind. Nuclear weapons possess an enormous destructive force. The immediacy and scale of destruction are unmatched. In addition to destruction, terrorism also aims to create fear among the public and governments. Here also, nuclear weapons are unmatched. The public's fear of nuclear weapons or, for that matter, of all radioactivity is intense. To some extent, this fear arises from a sense of unlimited vulnerability. That is, radioactivity is seen as unbounded in three dimensions - distance, it is viewed as having unlimited reach; quantity, it is viewed as having deadly consequences in the smallest doses (the public is often told - incorrectly, of course - that one atom of plutonium will kill); and time, if it does not kill you immediately, then it will cause cancer decades hence.

  15. The Parameter Space of Magnetized Target Fusion (aka Magneto-Inertial Fusion)

    NASA Astrophysics Data System (ADS)

    Lindemuth, Irvin

    2016-10-01

    Magnetized Target Fusion (MTF), aka Magneto-Inertial Fusion (MIF), is an approach to fusion that compresses a preformed, magnetized (but not necessarily magnetically confined) plasma with an imploding liner or pusher. MTF/MIF operates in a density regime in between the eleven orders of magnitude (1011) in density that separate inertial confinement fusion (ICF) from magnetic confinement fusion MCF. Compared to MCF, the higher density, shorter confinement times, and compressional heating as the dominant heating mechanism potentially reduce the impact of magnetic instabilities. Compared to ICF, the magnetically reduced thermal transport and lower density leads to orders-of-magnitude reduction in the difficult-to-achieve areal-density parameter and a significant reduction in required implosion velocity and radial convergence, potentially reducing the deleterious effects of implosion hydrodynamic instabilities. This tutorial presents fundamental analysis and simple time-dependent modeling to show where significant fusion gain might be achieved in the intermediate-density regime. The analysis shows that the fusion design space is potentially a continuum between ICF and MCF but practical considerations limit the space in which ignition might be obtained. Generic time-dependent modeling addresses the key physics requirements and defines ``ball-park'' values needed for target-plasma initial density, temperature, and magnetic field and implosion system size, energy, and velocity. The modeling shows energy gains greater than 30 can potentially be achieved and that high gain may be obtained at low convergence ratios, e.g., less than 15. A non-exhaustive review of past and present MTF/MIF efforts is presented and the renewed interest in MTF/MIF within the US (e.g., ARPA-E's ALPHA program) and abroad is noted.

  16. Search for systematic behavior of incomplete-fusion probability and complete-fusion suppression induced by {sup 9}Be on different targets

    SciTech Connect

    Gomes, P. R. S.; Linares, R.; Lubian, J.; Lopes, C. C.; Cardozo, E. N.; Pereira, B. H. F.

    2011-07-15

    We present a trial to obtain a systematic behavior of the results available in the literature on the complete and incomplete fusion induced by the weakly bound projectile {sup 9}Be on targets with different masses and/or charges. We stress that although the incomplete-fusion probability and the complete-fusion suppression are very closely related quantities, the first is an experimental value whereas the later is model dependent. A trend of systematic behavior for the incomplete-fusion probability as a function of the target charge is achieved, but not for the complete-fusion suppression.

  17. Generic Stellarator-like Magnetic Fusion Reactor

    NASA Astrophysics Data System (ADS)

    Sheffield, John; Spong, Donald

    2015-11-01

    The Generic Magnetic Fusion Reactor paper, published in 1985, has been updated, reflecting the improved science and technology base in the magnetic fusion program. Key changes beyond inflation are driven by important benchmark numbers for technologies and costs from ITER construction, and the use of a more conservative neutron wall flux and fluence in modern fusion reactor designs. In this paper the generic approach is applied to a catalyzed D-D stellarator-like reactor. It is shown that an interesting power plant might be possible if the following parameters could be achieved for a reference reactor: R/ < a > ~ 4 , confinement factor, fren = 0.9-1.15, < β > ~ 8 . 0 -11.5 %, Zeff ~ 1.45 plus a relativistic temperature correction, fraction of fast ions lost ~ 0.07, Bm ~ 14-16 T, and R ~ 18-24 m. J. Sheffield was supported under ORNL subcontract 4000088999 with the University of Tennessee.

  18. Designing a tokamak fusion reactor—How does plasma physics fit in?

    NASA Astrophysics Data System (ADS)

    Freidberg, J. P.; Mangiarotti, F. J.; Minervini, J.

    2015-07-01

    This paper attempts to bridge the gap between tokamak reactor design and plasma physics. The analysis demonstrates that the overall design of a tokamak fusion reactor is determined almost entirely by the constraints imposed by nuclear physics and fusion engineering. Virtually, no plasma physics is required to determine the main design parameters of a reactor: a , R 0 , B 0 , T i , T e , p , n , τ E , I . The one exception is the value of the toroidal current I , which depends upon a combination of engineering and plasma physics. This exception, however, ultimately has a major impact on the feasibility of an attractive tokamak reactor. The analysis shows that the engineering/nuclear physics design makes demands on the plasma physics that must be satisfied in order to generate power. These demands are substituted into the well-known operational constraints arising in tokamak physics: the Troyon limit, Greenwald limit, kink stability limit, and bootstrap fraction limit. Unfortunately, a tokamak reactor designed on the basis of standard engineering and nuclear physics constraints does not scale to a reactor. Too much current is required to achieve the necessary confinement time for ignition. The combination of achievable bootstrap current plus current drive is not sufficient to generate the current demanded by the engineering design. Several possible solutions are discussed in detail involving advances in plasma physics or engineering. The main contribution of the present work is to demonstrate that the basic reactor design and its plasma physics consequences can be determined simply and analytically. The analysis thus provides a crisp, compact, logical framework that will hopefully lead to improved physical intuition for connecting plasma physic to tokamak reactor design.

  19. A. Sakharov and Fusion Research

    NASA Astrophysics Data System (ADS)

    Coppi, Bruno

    2012-02-01

    In the landmark paper by Tamm and Sakharov [1], a controlled nuclear fusion reactor based on an axisymmetric magnetic confinement configuration whose principles remain valid to this day, was proposed. In the light of present understanding of plasma physics the virtues (e.g. that of considering the D-D reaction) and the shortcomings of this paper are pointed out. In fact, relatively recent results of theoretical plasma physics (e.g. discovery of the so called second stability region) and advances in high field magnet technology have made it possible to identify the parameters of meaningful experiments capable of exploring D-D and D-^3He burn conditions. At the same time an experimental program (IGNIR) has been undertaken through a (funded) collaboration between Italy and Russia to investigate D-T plasmas close to ignition conditions based on an advanced high field toroidal confinement configuration. A. Sakharov envisioned a bolder approach to fusion research than that advocated by some of his contemporaries. The time taken to design and decide to fabricate the first experiment capable of reaching ignition conditions is due in part to the problem of gaining an adequate understanding the expected physics of fusion burning plasmas. However, most of the relevant financial effort has gone in the pursuit of slow and indirect enterprises complying with the ``playing it safe'' tendencies of large organizations or motivated by the purpose to develop technologies or maintain a high level of expertise in plasma physics to the expected benefit of other kinds of endeavors. The creativity demonstrated by A. Sakharov in dealing with civil rights and disarmament issues is needed, while maintaining our concerns for energy and the environment on a global scale, to orient the funding for fusion research toward a direct and well based scientific effort on concepts for which a variety of developments can be envisioned. These can span from uncovering new physics relevant, for instance

  20. Laser-Driven Fusion.

    ERIC Educational Resources Information Center

    Gibson, A. F.

    1980-01-01

    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  1. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C

    2008-01-01

    Infection by viruses having lipid-bilayer envelopes proceeds through fusion of the viral membrane with a membrane of the target cell. Viral ‘fusion proteins’ facilitate this process. They vary greatly in structure, but all seem to have a common mechanism of action, in which a ligand-triggered, large-scale conformational change in the fusion protein is coupled to apposition and merger of the two bilayers. We describe three examples—the influenza virus hemagglutinin, the flavivirus E protein and the vesicular stomatitis virus G protein—in some detail, to illustrate the ways in which different structures have evolved to implement this common mechanism. Fusion inhibitors can be effective antiviral agents. PMID:18596815

  2. Fusion-breeder program

    SciTech Connect

    Moir, R.W.

    1982-11-19

    The various approaches to a combined fusion-fission reactor for the purpose of breeding /sup 239/Pu and /sup 233/U are described. Design aspects and cost estimates for fuel production and electricity generation are discussed. (MOW)

  3. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  4. Glossary of fusion energy

    NASA Astrophysics Data System (ADS)

    Whitson, M. O.

    1985-02-01

    The Glossary of Fusion Energy is an attempt to present a concise, yet comprehensive collection of terms that may be beneficial to scientists and laymen who are directly or tangentially concerned with this burgeoning energy enterprise. Included are definitions of terms in theoretical plasma physics, controlled thermonuclear fusion, and some related physics concepts. Also, short descriptions of some of the major thermonuclear experiments currently under way in the world today are included.

  5. Fusion ignition research experiment

    SciTech Connect

    Dale Meade

    2000-07-18

    Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.

  6. Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Biberian, Jean-Paul

    2006-02-01

    1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

  7. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2016-07-12

    ITER (in Latin “the way”) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen – deuterium and tritium – fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project – China, the European Union, India, Japan, Korea, Russia and the United States – represent more than half the world’s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

  8. Adaptive fusion of infrared and visible images in dynamic scene

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Yin, Yafeng; Man, Hong; Desai, Sachi

    2011-11-01

    Multiple modalities sensor fusion has been widely employed in various surveillance and military applications. A variety of image fusion techniques including PCA, wavelet, curvelet and HSV has been proposed in recent years to improve human visual perception for object detection. One of the main challenges for visible and infrared image fusion is to automatically determine an optimal fusion strategy for different input scenes along with an acceptable computational cost. This paper, we propose a fast and adaptive feature selection based image fusion method to obtain high a contrast image from visible and infrared sensors for targets detection. At first, fuzzy c-means clustering is applied on the infrared image to highlight possible hotspot regions, which will be considered as potential targets' locations. After that, the region surrounding the target area is segmented as the background regions. Then image fusion is locally applied on the selected target and background regions by computing different linear combination of color components from registered visible and infrared images. After obtaining different fused images, histogram distributions are computed on these local fusion images as the fusion feature set. The variance ratio which is based on Linear Discriminative Analysis (LDA) measure is employed to sort the feature set and the most discriminative one is selected for the whole image fusion. As the feature selection is performed over time, the process will dynamically determine the most suitable feature for the image fusion in different scenes. Experiment is conducted on the OSU Color-Thermal database, and TNO Human Factor dataset. The fusion results indicate that our proposed method achieved a competitive performance compared with other fusion algorithms at a relatively low computational cost.

  9. Magnetized Target Fusion: Principles and Status

    NASA Astrophysics Data System (ADS)

    Siemon, Richard; Lindemuth, Irvin; Ekdahl, Carl; Reinovsky, Robert; Schoenberg, Kurt

    1997-11-01

    Magnetized Target Fusion (MTF) is a relatively unexplored, low-cost approach that is intermediate in time and density scales between MFE and ICF and can be considered a marriage of the two. In contrast to ICF, MTF involves two steps: (a) formation of a warm (e.g., 100 eV or higher), magnetized (e.g., 100 kG), wall-confined plasma within a fusion target prior to implosion; (b) subsequent quasi-adiabatic compression and heating of the plasma by imploding the confining wall, or liner. Although the possible benefit of a magnetic field in a fusion target was recognized in the 40's by Fermi at Los Alamos and at approximately the same time by Sakharov in the former Soviet Union, it is only because of recent advancements in plasma formation techniques, implosion system drivers, plasma diagnostics, and large-scale numerical simulation capabilities that MTF can potentially achieve fusion ignition and substantial fuel burn-up without a major capital investment in a next-generation facility. Because MTF is qualitatively different from inertial or magnetic confinement fusion--different time, length, and density scales--MTF reactors will have different characteristics and trade-offs.

  10. HEDP and new directions for fusion energy

    SciTech Connect

    Kirkpatrick, Ronald C

    2009-01-01

    The Quest for fusion energy has a long history and the demonstration of thermonuclear energy release in 1951 represented a record achievement for high energy density. While this first demonstration was in response to the extreme fears of mankind, it also marked the beginning of a great hope that it would usher in an era of boundless cheap energy. In fact, fusion still promises to be an enabling technology that can be compared to the prehistoric utilization of fire. Why has the quest for fusion energy been so long on promises and so short in fulfillment? This paper briefly reviews past approaches to fusion energy and suggests new directions. By putting aside the old thinking and vigorously applying our experimental, computational and theoretical tools developed over the past decades we should be able to make rapid progress toward satisfying an urgent need. Fusion not only holds the key to abundant green energy, but also promises to enable deep space missions and the creation of rare elements and isotopes for wide-ranging industrial applications and medical diagnostics.

  11. 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.

  12. Pionic fusion in light-ion systems

    NASA Astrophysics Data System (ADS)

    Joulaeizadeh, L.; Gašparić, I.; Amir-Ahmadi, H. R.; Bacelar, J.; Čaplar, R.; Eslami-Kalantari, M.; Kalantar-Nayestanaki, N.; Löhner, H.; Mardanpour, H.; Messchendorp, J. G.; Moeini, H.; Ramazani-Moghaddam-Arani, A.; Shende, S. V.; Stephan, E.

    2011-01-01

    The role of pions in the nuclear interaction has been studied in pionic fusion experiments using the AGOR accelerator facility at KVI. Pionic fusion is a highly coherent process in which two nuclei fuse to a united nucleus and the available centre-of-mass (C.M.) energy is emitted through the pion channel. The examined reactions were 4He(3He, π0)7Be and 6Li(4He, π0)10B* and both reactions were performed at C.M. energies about 10 MeV above the coherent pion production threshold. Here, the experimental results for the 6Li(4He, π0)10B* reaction will be presented and discussed. In order to provide sensitivity to the full dynamics and relevant processes involved in the pionic fusion reaction, almost the full angular distribution of neutral pions has been determined. In a phenomenological analysis, the contributions of Legendre polynomials to reproduce the behaviour of the angular distribution have been studied. The results of this analysis confirm the importance of the clustering correlations for the 6Li(4He, π0)10B* reaction. The mass dependence of the pionic fusion reaction is in agreement with the results of the existing models extrapolated to this reaction.

  13. Fusion excitation functions involving transitional nuclei

    SciTech Connect

    Rehm, K.E.; Jiang, C.L.; Esbensen, H.

    1995-08-01

    Measurements of fusion excitation functions involving transitional nuclei {sup 78}Kr and {sup 100}Mo showed a different behavior at low energies, if compared to measurements with {sup 86}Kr and {sup 92}Mo. This points to a possible influence of nuclear structure on the fusion process. One way to characterize the structure of vibrational nuclei is via their restoring force parameters C{sub 2} which can be calculated from the energy of the lowest 2{sup +} state and the corresponding B(E2) value. A survey of the even-even nuclei between A = 28-150 shows strong variations in C{sub 2} values spanning two orders of magnitude. The lowest values for C{sub 2} are observed for {sup 78}Kr, {sup 104}Ru and {sup 124}Xe followed by {sup 74,76}Ge, {sup 74,76}Se, {sup 100}Mo and {sup 110}Pd. In order to learn more about the influence of {open_quotes}softness{close_quotes} on the sub-barrier fusion enhancement, we measured cross sections for evaporation residue production for the systems {sup 78}Kr + {sup 104}Ru and {sup 78}Kr + {sup 76}Ge with the gas-filled magnet technique. For both systems, fusion excitation functions involving the closed neutron shell nucleus {sup 86}Kr were measured previously. The data are presently being analyzed.

  14. Fusion product studies via fast ion D-D and D-3He fusion on JET

    NASA Astrophysics Data System (ADS)

    Sharapov, S. E.; Hellsten, T.; Kiptily, V. G.; Craciunescu, T.; Eriksson, J.; Fitzgerald, M.; Girardo, J.-B.; Goloborod'ko, V.; Hellesen, C.; Hjalmarsson, A.; Johnson, T.; Kazakov, Y.; Koskela, T.; Mantsinen, M.; Monakhov, I.; Nabais, F.; Nocente, M.; Perez von Thun, C.; Rimini, F.; Santala, M.; Schneider, M.; Tardocchi, M.; Tsalas, M.; Yavorskij, V.; Zoita, V.; Contributors, JET

    2016-11-01

    Dedicated fast ion D-D and D-3He fusion experiments were performed on JET with carbon wall (2008) and ITER-like wall (2014) for testing the upgraded neutron and energetic ion diagnostics of fusion products. Energy spectrum of D-D neutrons was the focus of the studies in pure deuterium plasmas. A significant broadening of the energy spectrum of neutrons born in D-D fast fusion was observed, and dependence of the maximum D and D-D neutron energies on plasma density was established. Diagnostics of charged products of aneutronic D-3He fusion reactions, 3.7 MeV alpha-particles similar to those in D-T fusion, and 14.6 MeV protons, were the focus of the studies in D-3He plasmas. Measurements of 16.4 MeV gamma-rays born in the weak secondary branch of D(3He, γ)5Li reaction were used for assessing D-3He fusion power. For achieving high yield of D-D and D-3He reactions at relatively low levels of input heating power, an acceleration of D beam up to the MeV energy range was used employing 3rd harmonic (f=3{{f}CD} ) ICRH technique. These results were compared to the techniques of D beam injection into D-3He mixture, and 3He-minority ICRH in D plasmas.

  15. Dielectric and electrical design consideration of ceramics for fusion devices

    NASA Astrophysics Data System (ADS)

    Ohno, H.

    1991-03-01

    The research and development of high performance ceramics for nuclear applications are increasing their importance. Especially in nuclear development, innovative and application of ceramics are needed in fusion reactors. Summarized are the development of new materials such as silicon nitride with good mechanical and electrical properties and the application of zirconia-based ceramics for high temperature electrolysis of tritiated water in a tritium recycling system.

  16. Infrared and color visible image fusion system based on luminance-contrast transfer technique

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Gong, Wenfeng; Wang, Chensheng

    2012-12-01

    In this paper, an infrared and color image fusion algorithm based on luminance-contrast transfer technique is presented. This algorithm shall operate YCbCr transform on color visible image, and obtain the luminance component. Then, the grey-scale image fusion methods are utilized to fuse the luminance component of visible and infrared images to acquire grey-scale fusion image. After that, the grey-scale fusion image and visible image are fused to form color fusion image based on inversed YCbCr transform. To acquire better details appearance, a natural-sense color transfer fusion algorithm based on reference image is proposed. Furthermore, a real-time infrared/visible image fusion system based on FPGA is realized. Finally, this design and achievement is verified experimentally, and the experimental results show that the system can produce a color fusion image with good image quality and real-time performance.

  17. Inertial fusion: an energy-production option for the future

    SciTech Connect

    Hovingh, J.; Pitts, J.H.; Monsler, M.J.; Grow, G.R.

    1982-05-01

    The authors discuss the inertial-confinement approach to fusion energy. After explaining the fundamentals of fusion, they describe the state of the art of fusion experiments, emphasizing the results achieved through the use of neodymium-doped glass lasers at Lawrence Livermore National Laboratory and at other laboratories. They highlight recent experimental results confirming theoretical predictions that short-wavelength lasers have excellent energy absorption on fuel pellets. Compressions of deuterium-tritium fuel of over 100 times liquid density have been measured, only a factor of 10 away from the compression required for a commercial reactor. Finally, it is shown how to exploit the unique characteristics of inertial fusion to design reactor chambers that have a very high power density and a long life, features that the authors believe will eventually lead to fusion power at a competitive cost.

  18. Optical sensed image fusion with dynamic neural networks

    NASA Astrophysics Data System (ADS)

    Shkvarko, Yuri V.; Ibarra-Manzano, Oscar G.; Jaime-Rivas, Rene; Andrade-Lucio, Jose A.; Alvarado-Mendez, Edgar; Rojas-Laguna, R.; Torres-Cisneros, Miguel; Alvarez-Jaime, J. A.

    2001-08-01

    The neural network-based technique for improving the quality of the image fusion is proposed as required for the remote sensing (RS) imagery. We prose to exit information about the point spread functions of the corresponding RS imaging systems combining it with prior realistic knowledge about the properties of the scene contained in the maximum entropy (ME) a priori image model. Applying the aggregate regularization method to solve the fusion tasks aimed to achieve the best resolution and noise suppression performances of the overall resulting image solves the problem. The proposed fusion method assumes the availability to control the design parameters, which influence the overall restoration performances. Computationally, the fusion method is implemented using the maximum entropy Hopfield-type neural network with adjustable parameters. Simulations illustrate the improved performances of the developed MENN-based image fusion method.

  19. Soldered joints—an essential component of demountable high temperature superconducting fusion magnets

    NASA Astrophysics Data System (ADS)

    Tsui, Yeekin; Surrey, Elizabeth; Hampshire, Damian

    2016-07-01

    Demountable superconducting magnet coils would offer significant benefits to commercial nuclear fusion power plants. Whether large pressed joints or large soldered joints provide the solution for demountable fusion magnets, a critical component or building block for both will be the many, smaller-scale joints that enable the supercurrent to leave the superconducting layer, cross the superconducting tape and pass into the solder that lies between the tape and the conductor that eventually provides one of the demountable surfaces. This paper considers the electrical and thermal properties of this essential component part of demountable high temperature superconducting (HTS) joints by considering the fabrication and properties of jointed HTSs consisting of a thin layer of solder (In52Sn48 or Pb38Sn62) sandwiched between two rare-earth-Ba2Cu3O7 (REBCO) second generation HTS coated conductors (CCs). The HTS joints are analysed using numerical modelling, critical current and resistivity measurements on the joints from 300 to 4.2 K in applied magnetic fields up to 12 T, as well as scanning electron microscopy studies. Our results show that the copper/silver layers significantly reduce the heating in the joints to less than a few hundred mK. When the REBCO alone is superconducting, the joint resistivity (R J) predominantly has two sources, the solder layer and an interfacial resistivity at the REBCO/silver interface (∼25 nΩ cm2) in the as-supplied CCs which together have a very weak magnetoresistance in fields up to 12 T. We achieved excellent reproducibility in the R J of the In52Sn48 soldered joints of better than 10% at temperatures below T c of the REBCO layer which can be compared to variations of more than two orders of magnitude in the literature. We also show that demountable joints in fusion energy magnets are viable and need only add a few percent to the total cryogenic cost for a fusion tokamak.

  20. Additive effects on the energy barrier for synaptic vesicle fusion cause supralinear effects on the vesicle fusion rate.

    PubMed

    Schotten, Sebastiaan; Meijer, Marieke; Walter, Alexander Matthias; Huson, Vincent; Mamer, Lauren; Kalogreades, Lawrence; ter Veer, Mirelle; Ruiter, Marvin; Brose, Nils; Rosenmund, Christian; Sørensen, Jakob Balslev; Verhage, Matthijs; Cornelisse, Lennart Niels

    2015-04-14

    The energy required to fuse synaptic vesicles with the plasma membrane ('activation energy') is considered a major determinant in synaptic efficacy. From reaction rate theory, we predict that a class of modulations exists, which utilize linear modulation of the energy barrier for fusion to achieve supralinear effects on the fusion rate. To test this prediction experimentally, we developed a method to assess the number of releasable vesicles, rate constants for vesicle priming, unpriming, and fusion, and the activation energy for fusion by fitting a vesicle state model to synaptic responses induced by hypertonic solutions. We show that complexinI/II deficiency or phorbol ester stimulation indeed affects responses to hypertonic solution in a supralinear manner. An additive vs multiplicative relationship between activation energy and fusion rate provides a novel explanation for previously observed non-linear effects of genetic/pharmacological perturbations on synaptic transmission and a novel interpretation of the cooperative nature of Ca(2+)-dependent release.