Science.gov

Sample records for achieving nuclear fusion

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

    SciTech Connect

    Nuckolls, J.H.

    1994-06-01

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

  2. Nuclear Fusion

    NASA Astrophysics Data System (ADS)

    Veres, G.

    This chapter is devoted to the fundamental concepts of nuclear fusion. To be more precise, it is devoted to the theoretical basics of fusion reactions between light nuclei such as hydrogen, helium, boron, and lithium. The discussion is limited because our purpose is to focus on laboratory-scale fusion experiments that aim at gaining energy from the fusion process. After discussing the methods of calculating the fusion cross section, it will be shown that sustained fusion reactions with energy gain must happen in a thermal medium because, in beam-target experiments, the energy of the beam is randomized faster than the fusion rate. Following a brief introduction to the elements of plasma physics, the chapter is concluded with the introduction of the most prominent fusion reactions ongoing in the Sun.

  3. 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…

  4. 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.

  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. EDITORIAL: The Nuclear Fusion Award The Nuclear Fusion Award

    NASA Astrophysics Data System (ADS)

    Kikuchi, M.

    2011-01-01

    The Nuclear Fusion Award ceremony for 2009 and 2010 award winners was held during the 23rd IAEA Fusion Energy Conference in Daejeon. This time, both 2009 and 2010 award winners were celebrated by the IAEA and the participants of the 23rd IAEA Fusion Energy Conference. The Nuclear Fusion Award is a paper prize to acknowledge the best distinguished paper among the published papers in a particular volume of the Nuclear Fusion journal. Among the top-cited and highly-recommended papers chosen by the Editorial Board, excluding overview and review papers, and by analyzing self-citation and non-self-citation with an emphasis on non-self-citation, the Editorial Board confidentially selects ten distinguished papers as nominees for the Nuclear Fusion Award. Certificates are given to the leading authors of the Nuclear Fusion Award nominees. The final winner is selected among the ten nominees by the Nuclear Fusion Editorial Board voting confidentially. 2009 Nuclear Fusion Award nominees For the 2009 award, the papers published in the 2006 volume were assessed and the following papers were nominated, most of which are magnetic confinement experiments, theory and modeling, while one addresses inertial confinement. Sabbagh S.A. et al 2006 Resistive wall stabilized operation in rotating high beta NSTX plasmas Nucl. Fusion 46 635-44 La Haye R.J. et al 2006 Cross-machine benchmarking for ITER of neoclassical tearing mode stabilization by electron cyclotron current drive Nucl. Fusion 46 451-61 Honrubia J.J. et al 2006 Three-dimensional fast electron transport for ignition-scale inertial fusion capsules Nucl. Fusion 46 L25-8 Ido T. et al 2006 Observation of the interaction between the geodesic acoustic mode and ambient fluctuation in the JFT-2M tokamak Nucl. Fusion 46 512-20 Plyusnin V.V. et al 2006 Study of runaway electron generation during major disruptions in JET Nucl. Fusion 46 277-84 Pitts R.A. et al 2006 Far SOL ELM ion energies in JET Nucl. Fusion 46 82-98 Berk H.L. et al 2006

  7. 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

  8. 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…

  9. 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.

  10. Plasma Physics and Controlled Nuclear Fusion

    NASA Astrophysics Data System (ADS)

    Fisch, N. J.

    2010-01-01

    Already while making his famous contributions in uncontrolled nuclear fusion for wartime uses, Edward Teller contemplated how the abundant energy release through nuclear fusion might serve peacetime uses as well. His legacy in controlled nuclear fusion, and the associated physics of plasmas, spans both magnetic and inertial confinement approaches. His contributions in plasma physics, both the intellectual and the administrative, continue to impact the field.

  11. 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

  12. 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).

  13. High-Frequency Gravitational Wave Induced Nuclear Fusion

    NASA Astrophysics Data System (ADS)

    Fontana, Giorgio; Baker, Robert M. L.

    2007-01-01

    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.

  14. 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.

  15. 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.

  16. 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)

  17. Lithium question for nuclear fusion

    SciTech Connect

    Shieh, P.S.S.

    1981-01-01

    An attempt is made to estimate the lithium reserve (the economically recoverable lithium) for the tritium breeding in D-T fusion reactors and other uses. Similar development patterns for fusion energy and fission energy are assumed to estimate the future lithium requirements. These requirements are grouped into three categories; the commercial uses, the lithium batteries for electric cars, and the fusion reactor uses. 5 refs.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Design considerations for achieving high vacuum integrity in fusion devices

    SciTech Connect

    Fuller, G.M.; Haines, J.R.

    1983-01-01

    Achieving high vacuum integrity in fusion devices requires close attention to both the overall system configuration and the design details of joints and seals. This paper describes the factors in selecting the system configuration, from a vacuum standpoint, for the Princeton Plasma Physics Laboratory (PPPL) DCT-8 Tokamak device. The DCT-8 (driven current tokamak) is the eighth design in a series of tokamak concepts defined to cover the magnetic confinement and development gap between the Tokamak Fusion Test Reactor (TFTR) and the Engineering Test Reactor (ETR). Leak detection concept development is considered a vital activity, as well as the definition of a configuration that minimizes the consequences of leaks. A major part of the vacuum boundaries of the magnet system and the plasma system is common. For the major penetrations, primary and secondary seals are provided with vacuum control over the region between seals. The intent is to instrument these cavities and provide automated recordings of these measurements for leak maintenance.

  4. 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.

  5. 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. )

  6. 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. PMID:19570912

  7. 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.

  8. 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.

  9. Kinetic advantage of controlled intermediate nuclear fusion

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoming

    2012-09-01

    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.

  10. 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.

  11. Magnet design considerations for Fusion Nuclear Science Facility

    DOE PAGES

    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 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

  12. Nuclear diagnostics in support of inertial confinement fusion experiments (invited)

    SciTech Connect

    Moran, M.J.; Hall, J.

    1997-01-01

    As the yields of inertial confinement fusion (ICF) experiments increase to National Ignition Facility levels new diagnostic techniques for studying details of fusion burn behavior will become feasible. The new techniques will provide improved measurements of fusion burn temperature and history. Improved temperature measurements might be achieved with magnetic spectroscopy of fusion neutrons. High-bandwidth fusion reaction history will be measured with fusion-specific {gamma}-ray diagnostics. Additional energy-resolved {gamma}-ray diagnostics might be able to study a selection of specific behaviors during fusion burn. Present ICF yields greater that 10{sup 13} neutrons are sufficient to demonstrate the basic methods that underlie the new techniques. As ICF yields increase, the diagnostics designs can be adjusted accordingly in order to provide clear and specific data on fusion burn performance. {copyright} {ital 1997 American Institute of Physics.}

  13. 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.

  14. 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…

  15. Fusion option to dispose of spent nuclear fuel and transuranic elements

    SciTech Connect

    Gohar, Y.

    2000-02-10

    The fusion option is examined to solve the disposition problems of the spent nuclear fuel and the transuranic elements. The analysis of this report shows that the top rated solution, the elimination of the transuranic elements and the long-lived fission products, can be achieved in a fusion reactor. A 167 MW of fusion power from a D-T plasma for sixty years with an availability factor of 0.75 can transmute all the transuranic elements and the long-lived fission products of the 70,000 tons of the US inventory of spent nuclear fuel generated up to the year 2015. The operating time can be reduced to thirty years with use of 334 MW of fusion power, a system study is needed to define the optimum time. In addition, the fusion solution eliminates the need for a geological repository site, which is a major advantage. Meanwhile, such utilization of the fusion power will provide an excellent opportunity to develop fusion energy for the future. Fusion blankets with a liquid carrier for the transuranic elements can achieve a transmutation rate for the transuranic elements up to 80 kg/MW.y of fusion power with k{sub eff} of 0.98. In addition, the liquid blankets have several advantages relative to the other blanket options. The energy from this transmutation is utilized to produce revenue for the system. Molten salt (Flibe) and lithium-lead eutectic are identified as the most promising liquids for this application, both materials are under development for future fusion blanket concepts. The Flibe molten salt with transuranic elements was developed and used successfully as nuclear fuel for the molten salt breeder reactor in the 1960's.

  16. On the economic prospects of nuclear fusion with tokamaks

    NASA Astrophysics Data System (ADS)

    Pfirsch, D.; Schmitter, K. H.

    1987-12-01

    A method of cost and construction energy estimation for tokamak fusion power stations conforming to the present stage of fusion development is described. The method is based on first-wall heat load constraints rather than Beta limitations, which, however, might eventually be the more critical of the two. It is used to discuss the economic efficiency of pure fusion, with particular reference to the European study entitled Environmental Impact and Economic Prospects of Nuclear Fusion (1986). It is shown that the claims made therein for the economic prospects of pure fusion with tokamaks, when discussed on the basis of the present-day technology, do not stand up to critical examination. A fusion-fission hybrid, however, could afford more positive prospects. Support for the stated method is derived when it is properly applied for cost estimation of advanced gas-cooled and Magnox reactors, the two examples presented by the European study to disprove it.

  17. [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.

  18. 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

  19. NUCLEAR MEMBRANE FUSION IN FERTILIZED LYTECHINUS VARIEGATUS EGGS

    PubMed Central

    Aronson, John F.

    1973-01-01

    Fusion of apposed nuclear envelopes is frequently seen at telophase during postmitotic reorganization of the nucleus, but only rarely at other times in the cell cycle. We attempted to define an experimental system for studying changes in the nuclear envelope related to the cell cycle by varying the time of pronuclear apposition in fertilized Lytechinus variegatus eggs. This approach was based on the assumption that the period from fertilization to metaphase of the first cleavage division corresponds to the period from telophase to metaphase in the generalized cell cycle. The experimental approach used was to block the movement of the pronuclei with Colcemid and then to release this block at varying times after insemination by photochemically inactivating the Colcemid. The results show that apposed pronuclear envelopes can fuse from soon after insemination until the anticipated time of prometaphase. Fusion occurred in about 3 min as scored by light microscopy and this time did not vary significantly with the time after insemination. The potential for nuclear fusion is not restricted to pronuclei alone since diploid nuclei in binucleate cells could be fused using centrifugation in solutions of Colcemid to bring the nuclei into apposition. It is suggested that the potential for nuclear fusion is not necessarily related to the cell cycle and that modification of the nuclear envelope, possibly by association with chromatin or other fibrous material restricts nuclear fusion in most multinucleated cells. PMID:4125367

  20. Avalanche proton-boron fusion based on elastic nuclear collisions

    NASA Astrophysics Data System (ADS)

    Eliezer, Shalom; Hora, Heinrich; Korn, Georg; Nissim, Noaz; Martinez Val, Josè Maria

    2016-05-01

    Recent experiments done at Prague with the 600 J/0.2 ns PALS laser interacting with a layer of boron dopants in a hydrogen enriched target have produced around 109 alphas. We suggest that these unexpected very high fusion reactions of proton with 11B indicate an avalanche multiplication for the measured anomalously high nuclear reaction yields. This can be explained by elastic nuclear collisions in the broad 600 keV energy band, which is coincident with the high nuclear p-11B fusion cross section, by the way of multiplication through generation of three secondary alpha particles from a single primarily produced alpha particle.

  1. 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.

  2. 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.

  3. 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.

  4. Beyond the Coherent Coupled Channels Description of Nuclear Fusion

    SciTech Connect

    Dasgupta, M.; Hinde, D. J.; Diaz-Torres, A.; Bouriquet, B.; Low, Catherine I.; Newton, J. O.; Milburn, G. J.

    2007-11-09

    New measurements of fusion cross sections at deep sub-barrier energies for the reactions {sup 16}O+{sup 204,208}Pb show a steep but almost saturated logarithmic slope, unlike {sup 64}Ni-induced reactions. Coupled channels calculations cannot simultaneously reproduce these new data and above-barrier cross-sections with the same Woods-Saxon nuclear potential. It is argued that this highlights an inadequacy of the coherent coupled channels approach. It is proposed that a new approach explicitly including gradual decoherence is needed to allow a consistent description of nuclear fusion.

  5. 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

  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. Nuclear design of a very-low-activation fusion reactor

    SciTech Connect

    Cheng, E.T.; Hopkins, G.R.

    1983-06-01

    An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design.

  8. 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.

  9. 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.

  10. 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.

  11. Burning nuclear wastes in fusion reactors

    SciTech Connect

    Meldner, H.W.; Howard, W.M.

    1980-02-20

    We have studied actinide burn-up in ICF reactor pellets; i.e., 14 MeV neutron fission of the very long-lived actinides that pose storage problems. A major advantage of pellet fuel region burn-up is safety: only milligrams of highly toxic and active material need to be present in the fusion chamber, whereas blanket burn-up requires the continued presence of tons of actinides in a small volume. The actinide data tables required for Monte Carlo calculations of the burn-up of /sup 241/Am and /sup 243/Am are discussed in connection with a study of the sensitivity to cross section uncertainties. More accurate and complete cross sections are required for realistic quantitative calculations.

  12. 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.

  13. Seeking the Limits of Low-Temperature Nuclear Fusion: Sticking in Muon-Catalyzed Fusion, and Piezonuclear Fusion in Deuterium/condensed Matter Systems

    NASA Astrophysics Data System (ADS)

    Taylor, Stuart F.

    Studies seeking an upper limit of two types of low temperature nuclear fusion is presented. The upper limit for muon catalyzed fusion is generally considered to be the number of fusions per muon obtainable. The limiting factor has been found to be how often the muon remains bound to the alpha produced by the fusion, known as the "sticking fraction." Experiments directly measuring the sticking and determining the sticking using high tritium fractions are presented. In deuterium/condensed matter systems the question is nearly whether nuclear fusion proceeds at all. Experiments where neutrons around deuterided titanium and palladium are measured are presented.

  14. Concept evaluation of nuclear fusion driven symbiotic energy systems

    NASA Astrophysics Data System (ADS)

    Renier, J. P.; Hoffman, T. J.

    An analysis of systems based on D-T and semi-catalyzed D-D fusion-powered U233 breeders is presented. Metallic thorium pebble-bed blankets with a batch reprocessing mode and a molten salt blanket with on-line continuous or batch reprocessing were used. Neutronics depletion calculations are coupled with a scenario optimization and a cost analysis code. The fusion-driven symbiotes are compared with LMFBR-driven energy systems. The analyses of the symbiotic energy systems were performed at equilibrium, at the maximum rate of grid expansion and for a given nuclear power demand. Attractive schemes are identified based on D-T driven fusion-drivers operated with low plasma performance parameters.

  15. Fusion Nuclear Science Facility (FNSF) before Upgrade to Component Test Facility (CTF)

    SciTech Connect

    Peng, Yueng Kay Martin

    2010-01-01

    The compact (R0~1.2-1.3m) Fusion Nuclear Science Facility (FNSF) is aimed at providing a fully integrated, continuously driven fusion nuclear environment of copious fusion neutrons. This facility would be used to test, discover, understand, and innovate scientific and technical solutions for the challenges facing DEMO, by addressing the multi-scale synergistic interactions involving fusion plasma material interactions, tritium fuel cycle, power extraction, and the nuclear effects on materials. Such a facility properly designed would provide, initially at the JET-level plasma pressure (~30%T2) and conditions (e.g., Hot-Ion H-Mode), an outboard fusion neutron flux of 0.25 MW/m2 while requiring a fusion power of 19 MW. If and when this research operation is successful, its performance can be extended to 1 MW/m2 and 76 MW by reaching for twice the JET plasma pressure and Q. High-safety factor q and moderate- plasmas would minimize plasma-induced disruptions, helping to deliver reliably a neutron fluence of 1 MW-yr/m2 and a duty factor of 10% presently anticipated for the FNS research. Success of this research will depend on achieving time-efficient installation and replacement of all components using extensive remote handling (RH). This in turn requires modular designs for all internal components, including the single-turn toroidal field coil center-post with RH-compatible bi-directional sliding joints. Such device goals would further dictate placement of support structures and vacuum seal welds behind the internal and shielding components. If these further goals could be achieved, the FNSF would provide a ready upgrade path to the Component Test Facility (CTF), which would aim to test, at higher neutron fluence and duty cycle, the demanding fusion nuclear engineering and technologies for DEMO. This FNSF-CTF strategy would be complementary to the ITER and the Broader Approach programs, and thereby help mitigate the risks of an aggressive world fusion DEMO R&D Program

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Fusion-fission hybrids for nuclear waste transmutation : a synergistic step between Gen-IV fission and fusion reactors.

    SciTech Connect

    Olson, Craig Lee; Mehlhorn, Thomas Alan; Cipiti, Benjamin B.; Rochau, Gary Eugene

    2007-09-01

    Energy demand and GDP per capita are strongly correlated, while public concern over the role of energy in climate change is growing. Nuclear power plants produce 16% of world electricity demands without greenhouse gases. Generation-IV advanced nuclear energy systems are being designed to be safe and economical. Minimizing the handling and storage of nuclear waste is important. NIF and ITER are bringing sustainable fusion energy closer, but a significant gap in fusion technology development remains. Fusion-fission hybrids could be a synergistic step to a pure fusion economy and act as a technology bridge. We discuss how a pulsed power-driven Z-pinch hybrid system producing only 20 MW of fusion yield can drive a sub-critical transuranic blanket that transmutes 1280 kg of actinide wastes per year and produces 3000 MW. These results are applicable to other inertial and magnetic fusion energy systems. A hybrid system could be introduced somewhat sooner because of the modest fusion yield requirements and can provide both a safe alternative to fast reactors for nuclear waste transmutation and a maturation path for fusion technology. The development and demonstration of advanced materials that withstand high-temperature, high-irradiation environments is a fundamental technology issue that is common to both fusion-fission hybrids and Generation-IV reactors.

  2. 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

  3. Metal Catalyzed Fusion: Nuclear Active Environment vs. Process

    NASA Astrophysics Data System (ADS)

    Chubb, Talbot

    2009-03-01

    To achieve radiationless dd fusion and/or other LENR reactions via chemistry: some focus on environment of interior or altered near-surface volume of bulk metal; some on environment inside metal nanocrystals or on their surface; some on the interface between nanometal crystals and ionic crystals; some on a momentum shock-stimulation reaction process. Experiment says there is also a spontaneous reaction process.

  4. 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.

  5. A Sustainable Nuclear Fuel Cycle Based on Laser Inertial Fusion Energy

    SciTech Connect

    Moses, E; Diaz de la Rubia, T; Storm, E; Latkowski, J; Farmer, J; Abbott, R; Kramer, K; Peterson, P; Shaw, H; Lehman II, R

    2009-05-22

    The National Ignition Facility (NIF), a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, will soon be completed at the Lawrence Livermore National Laboratory. Experiments designed to accomplish the NIF's goal will commence in 2010, using laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 35 MJ are expected soon thereafter. They propose that a laser system capable of generating fusion yields of 35 to 75 MJ at 10 to 15 Hz (i.e., {approx} 350- to 1000-MW fusion and {approx} 1.3 to 3.6 x 10{sup 20} n/s), coupled to a compact subdritical fission blanket, could be used to generate several GW of thermal power (GWth) while avoiding carbon dioxide emissions, mitigating nuclear proliferation concerns and minimizing the concerns associated with nuclear safety and long-term nuclear waste disposition. this Laser Inertial Fusion Energy (LIFE) based system is a logical extension of the NIF laser and the yields expec ted from the early ignition experiments on NIF. The LIFE concept is a once-through,s elf-contained closed fuel cycle and would have the following characteristics: (1) eliminate the need for spent fuel chemical separation facilities; (4) maintain the fission blanket subcritical at all times (k{sub eff} < 0.90); and (5) minimize future requirements for deep underground geological waste repositories and minimize actinide content in the end-of-life nuclear waste below the Department of Energy's (DOE's) attractiveness Level E (the lowest). Options to burn natural or depleted U, Th, U/Th mixtures, Spent Nuclear Fuel (SNF) without chemical separations of weapons-attractive actinide streams, and excess weapons Pu or highly enriched U (HEU) are possible and under consideration. Because the fission blanket is always subcritical and decay heat removal is possible via passive mechanisms, the technology is inherently safe. Many technical challenges must be met, but a LIFE solution

  6. 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)

  7. 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.

  8. 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

  9. 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. PMID:16740666

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

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

    SciTech Connect

    Abdou, M.

    1984-10-01

    The following chapters are included in this study: (1) fusion nuclear issues, (2) survey of experimental needs, (3) requirements of the experiments, (4) non-fusion facilities, (5) fusion facilities for nuclear experiments, and (6) fusion research and development scenarios. (MOW)

  16. Laser in vessel-viewing system for nuclear fusion reactors

    NASA Astrophysics Data System (ADS)

    Bartolini, Luciano; Bordone, Andrea; Coletti, Alberto; Ferri De Collibus, Mario; Fornetti, Giorgio G.; Lupini, S.; Neri, Carlo; Poggi, Claudio; Riva, Marco; Semeraro, Luigi; Talarico, Carlo

    2000-11-01

    An amplitude modulated laser radar has been developed by ENEA (Italian Agency for New Technologies, Energy and Environment) for periodic in-vessel inspection in large fusion machines. Its overall optical design has been developed taking into account the extremely high radiation levels and operating temperatures foreseen in large European fusion machines such as JET (Joint European Torus) and ITER (International Thermo- nuclear Experimental Reactor). The viewing system is based on a transceiving optical radar using a RF modulated single mode 840 nm wavelength laser beam. The sounding beam is transmitted through a coherent optical fiber and a focusing optic to the inner part of the nuclear reactor vessel by a stainless steel probe on the tip of which a suitable scanning silica prism steers the laser beam along a linear raster spanning a -90 degree(s) to +60 degree(s) in elevation and 360 degree(s) in azimuth for a complete mapping of the vessel itself. All the electronics, including the laser source, avalanche photodiode and all the active components are located outside the bioshield, while passive components (receiving optics, transmitting collimator, fiber optics), located in the torus hall, are made of fused silica so that the overall laser radar is radiation resistant. The signal is acquired, the raster lines being synchronized with the aid of optical encoders linked to the scanning prism, thus yielding a TV like image. Preliminary results have been obtained scanning large sceneries including several real targets having different backscattering properties, colors and surface reflectivity ranging over several decades to simulate the expected dynamic range of the video signals incoming from the vessel.

  17. 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.

  18. 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.

  19. 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

    2012-08-01

    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.

  20. Outlook: Scientific obstacles. [Scientific obstacles to commercial nuclear fusion

    SciTech Connect

    Not Available

    1993-01-22

    There is no question that fusion technology has come a long way. And yet commercial fusion energy seems as distant as ever. Numerous questions remain unanswered: Is magnetic fusion more promising than inertial fusion Which physical concept for a reactor is the best one Will the fully developed technology be economically competitive with other sources of energy Will fusion be as clean as promised And most fundamentally, can scientists make it work at all This article summarizes some of technological issues and hurdles facing fusion programs. Also, potential considerations are examined.

  1. 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.

  2. 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.

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. Georgia Tech Studies of Sub-Critical Advanced Burner Reactors with a D-T Fusion Tokamak Neutron Source for the Transmutation of Spent Nuclear Fuel

    NASA Astrophysics Data System (ADS)

    Stacey, W. M.

    2009-09-01

    The possibility that a tokamak D-T fusion neutron source, based on ITER physics and technology, could be used to drive sub-critical, fast-spectrum nuclear reactors fueled with the transuranics (TRU) in spent nuclear fuel discharged from conventional nuclear reactors has been investigated at Georgia Tech in a series of studies which are summarized in this paper. It is found that sub-critical operation of such fast transmutation reactors is advantageous in allowing longer fuel residence time, hence greater TRU burnup between fuel reprocessing stages, and in allowing higher TRU loading without compromising safety, relative to what could be achieved in a similar critical transmutation reactor. The required plasma and fusion technology operating parameter range of the fusion neutron source is generally within the anticipated operational range of ITER. The implications of these results for fusion development policy, if they hold up under more extensive and detailed analysis, is that a D-T fusion tokamak neutron source for a sub-critical transmutation reactor, built on the basis of the ITER operating experience, could possibly be a logical next step after ITER on the path to fusion electrical power reactors. At the same time, such an application would allow fusion to contribute to meeting the nation's energy needs at an earlier stage by helping to close the fission reactor nuclear fuel cycle.

  8. 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.

  9. 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

  10. 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.

  11. Nuclear-data needs for inertial-confinement fusion (ICF)

    SciTech Connect

    Haight, R.C.; Motz, H.T.

    1983-05-09

    Our survey was limited to ICF programs in the United States. It included researchers in laser and heavy ion fusion, target design, target diagnostics, and conceptual reactor design. We asked each of these people to read the current data needs for magnetic fusion energy and to comment on additional data that they require.

  12. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

    2015-06-01

    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.

  14. 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.

  15. 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.

  16. Observation of nuclear fusion driven by a pyroelectric crystal.

    PubMed

    Naranjo, B; Gimzewski, J K; Putterman, S

    2005-04-28

    While progress in fusion research continues with magnetic and inertial confinement, alternative approaches--such as Coulomb explosions of deuterium clusters and ultrafast laser-plasma interactions--also provide insight into basic processes and technological applications. However, attempts to produce fusion in a room temperature solid-state setting, including 'cold' fusion and 'bubble' fusion, have met with deep scepticism. Here we report that gently heating a pyroelectric crystal in a deuterated atmosphere can generate fusion under desktop conditions. The electrostatic field of the crystal is used to generate and accelerate a deuteron beam (> 100 keV and >4 nA), which, upon striking a deuterated target, produces a neutron flux over 400 times the background level. The presence of neutrons from the reaction D + D --> 3He (820 keV) + n (2.45 MeV) within the target is confirmed by pulse shape analysis and proton recoil spectroscopy. As further evidence for this fusion reaction, we use a novel time-of-flight technique to demonstrate the delayed coincidence between the outgoing alpha-particle and the neutron. Although the reported fusion is not useful in the power-producing sense, we anticipate that the system will find application as a simple palm-sized neutron generator. PMID:15858570

  17. Cell fusion to study nuclear-cytoplasmic interactions in endothelial cell apoptosis.

    PubMed Central

    Polunovsky, V. A.; Ingbar, D. H.; Peterson, M.; Bitterman, P. B.

    1996-01-01

    Studies examining the regulation of nuclear rearrangements during apoptosis have led to conflicting results. Cytoplasmic control of nuclear events has been strongly suggested by cell-free experimental systems. In contrast, strict cytoplasmic control cannot account for the results of fibroblast-thymocyte fusion experiments in which dexamethasone induction of polykaryons led only to thymocyte nuclear apoptosis. Unresolved by these fusion studies was whether fibroblast nuclei were indifferent to heterologous cytoplasmic signals. Our objective was to resolve this discrepancy using cell fusion in a homologous system. Our strategy was to fuse endothelial cells with high levels of susceptibility to the induction of apoptosis (log phase cells arrested in G1 for 48 hours by isoleucine deprivation) with those manifesting low levels of susceptibility (serum-deprived, G0). Resultant fused and unfused cells were induced to undergo apoptosis by incubation with tumor necrosis factor-alpha and cycloheximide. Depending on the parental cell of origin, between 14 and 30% of dikaryons contained one apoptotic and one intact nucleus, indicating that strict cytoplasmic control was not occurring. In accord with this, the total frequency of nuclear apoptosis was unchanged after fusion. However, the distribution of apoptotic nuclei revealed a pronounced cytoplasmic influence, with a two- to fivefold increase in coordinate nuclear behavior. This pattern of nuclear apoptosis was consistent with a model of control in which both the state of nuclear susceptibility to apoptosis and expression of cytoplasmic pro-apoptotic regulators determined whether nuclear apoptosis would eventuate. Images Figure 3 Figure 4 PMID:8686735

  18. 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.

  19. Nuclear fuels for low-beta fusion reactors: Lithium resources revisited

    SciTech Connect

    Eckhartt, D.

    1995-12-01

    In searching to attain optimum conditions for the controlled release of nuclear energy by fusion processes, the stationary confinement of low-pressure ring-shaped plasmas by strong magnetic fields is now regarded as the most promising approach. The author considers a number of fuel combinations that could be operated in such low-beta reactor systems and looks upon the relevant fuel reserves. The {open_quotes}classical{close_quotes} D-T-Li cycle will be used as a standard and is extensively discussed therefore. It could supply most of mankind`s future long-term power needs - but only on condition that the required lithium fuel can be extracted from seawater at reasonable expenses. The estimated land-bound lithium reserves are too small to that end, they will last for about 500 years at most, depending on forecasts of future energy consumption and on assumptions about exploitable resources. Recovery of lithium from seawater would extend the possible range by a factor of 300 or so, provided that extraction technologies which are at present available in the laboratory, could be extended to a very large and industrial scale. Deuterium is abundant on earth but D-D fusion is difficult, if not impossible, to be achieved in the low-beta systems presently investigated for D-T fusion. The same arguments apply to so-called {open_quotes}advanced{close_quotes} concepts, such as the D-{sup 3}He and the D-{sup 6}Li cycles. 37 refs., 1 fig., 1 tab.

  20. 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.

  1. 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.

  2. 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.

  3. Role of surface energy coefficients and nuclear surface diffuseness in the fusion of heavy-ions

    NASA Astrophysics Data System (ADS)

    Dutt, Ishwar; Puri, Rajeev K.

    2010-04-01

    We discuss the effect of surface energy coefficients as well as nuclear surface diffuseness in the proximity potential and ultimately in the fusion of heavy-ions. Here we employ different versions of surface energy coefficients. Our analysis reveals that these technical parameters can influence the fusion barriers by a significant amount. A best set of these parameters is also given that explains the experimental data nicely.

  4. Fusion: The controversy continues

    SciTech Connect

    1989-07-01

    Nuclear fusion-the power of the stars that promises mankind an inexhaustible supply of energy-seems concurrently much closer and still distant this month. The recent flurry of announcements concerning the achievement of a cold fusion reaction has-if nothing else-underscored the historic importance of the basic fusion reaction which uses hydrogen ions to fuel an energy-producing reaction.

  5. 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

  6. 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.

  7. 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. )

  8. 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.

  9. 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.

  10. 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.

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

    PubMed Central

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

    2016-01-01

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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. A fusion-driven gas core nuclear rocket

    SciTech Connect

    Kammash, T.; Godfroy, T.

    1998-01-15

    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.

  18. 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. PMID:26064528

  19. 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.

  20. 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.

  1. 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.

  2. 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. PMID:25560310

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

    PubMed Central

    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. PMID:25560310

  4. 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.

  5. 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

  6. Nuclear fusion of protons with ions of boron

    SciTech Connect

    Ruggiero, A.G.

    1993-06-01

    This paper describes a method of extracting energy from the fusion events occurring between the collision of a beam of protons with a beam of ions of Boron 11. The two beams are circulating in separated and intersecting storage rings where they collide head-on in a common long-straight section. Requirements on the beam parameters in the collider are presented. Limitations due to space-charge forces are discussed; it is found necessary to provide beam-charge neutralization with electrons. The paper discusses also the effects of Coulomb scattering between particles of the same beam and in the opposing beams. Methods are proposed for the controlling of the electromagnetic interaction.

  7. Nuclear fusion of protons with ions of boron

    SciTech Connect

    Ruggiero, A.G.

    1993-01-01

    This paper describes a method of extracting energy from the fusion events occurring between the collision of a beam of protons with a beam of ions of Boron 11. The two beams are circulating in separated and intersecting storage rings where they collide head-on in a common long-straight section. Requirements on the beam parameters in the collider are presented. Limitations due to space-charge forces are discussed; it is found necessary to provide beam-charge neutralization with electrons. The paper discusses also the effects of Coulomb scattering between particles of the same beam and in the opposing beams. Methods are proposed for the controlling of the electromagnetic interaction.

  8. 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

  9. 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.

  10. Nuclear performance optimization of the molten-salt fusion breeder

    SciTech Connect

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

    1986-06-05

    Improved nuclear analysis, including the treatment of resonance and spatial self-shielding, coupled with an optimization procedure, has resulted in an improved performance estimate for the molten salt blanket. Net U-233 breeding ratio ranges between 0.58 and 0.63, and blanket energy multiplication ranges between 1.8 and 1.9.

  11. 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.

  12. Achieving cross-border consistency during a nuclear emergency.

    PubMed

    Haywood, Stephanie; Majerus, Patrick

    2014-11-01

    The aim of the HERCA working group on emergencies (WGE) is to develop proposals to align decisions of European national crisis management organisations in a consistent manner during a nuclear emergency. The focus is to enhance the cooperation between the European organisations responsible for emergency radiological assessment, such as nuclear safety and radiological safety authorities, and their respective technical support organisations. A common understanding of a given emergency situation between those bodies will form the basis for consistent appropriate recommendations on protective actions and other response actions. The aim is to develop proposals which apply both to an accident within the boundaries of the HERCA member countries and also to a distant accident (such as Fukushima). PMID:24184142

  13. 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. )

  14. Tokamak D T fusion neutron source requirements for closing the nuclear fuel cycle

    NASA Astrophysics Data System (ADS)

    Stacey, W. M.

    2007-03-01

    This paper summarizes a series of conceptual design studies conducted with the purpose of determining if tokamak fusion neutron sources based on ITER physics and technology could meet the neutron source requirements for sub-critical fast-spectrum nuclear reactors that would help to close the nuclear fuel cycle by transmuting the transuranics in spent nuclear fuel. The studies were constrained to nuclear reactor and materials technologies under consideration in the US nuclear programme. Fuel cycle studies indicate that fusion neutron sources in the range ~200-500 MW would meet the needs of transmutation reactors, depending on other constraints such as materials damage to the nuclear fuel. A tokamak with R = 3.75 m, a = 1.1 m, B = 5.7-5.9 T, q95 = 3.00-4.0, I = 8.3-10 MA, βN = 2.0-2.85, HIPB98 = 1.0-1.06, γcd = 0.6 A Wm-2 would meet these requirements.

  15. 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 "discipline" imposes…

  16. 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.

  17. Experiments and nuclear measurements in search of cold fusion processes

    NASA Astrophysics Data System (ADS)

    Gottesfeld, S.; Anderson, R. E.; Baker, D. A.; Bolton, R. D.; Butterfield, K. B.; Garzon, F. H.; Goulding, C. A.; Johnson, M. W.; Leonard, E. M.; Springer, T. E.; Zawodzinski, T.

    1990-09-01

    This paper reports a collaborative effort of a team which formed at Los Alamos to investigate the announcement that “cold fusion” may be occurring in electrochemical cells using palladium cathodes and platinum anodes in a LiOD electrolyte. Four electrochemical cells were construced and operated for 3-5 weeks under various geometrical and electrical conditions. Nuclear diagnostic measurements included high and low resolution gamma-ray spectroscopy, integral neutron counting with well detectors and banks of3He tubes, and neutron spectroscopy with NE-213 scintillators. For one of the cells, the deuterium loading of the cathode was determined from resistance measurements to be D/Pd⩽ 0.8. No conclusive evidence was found for the production of neutrons or 2.223-MeV gammas above levels consistent with background. The results of the measurements of tritium levels in the cell electrolytes are also reported. Experiments to reproduce the observation of neutrons from high pressure Ti- D 2 gas experiments were also performed with negative results.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. 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' demands for,…

  1. 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.

  2. Nuclear fusion as a probe for octupole deformation in 224Ra

    NASA Astrophysics Data System (ADS)

    Kumar, Raj; Lay, J. A.; Vitturi, A.

    2015-11-01

    Background: Nuclear fusion has been shown to be a useful probe to study the different nuclear shapes. However, the possibility of testing octupole deformation of a nucleus with this tool has not been fully explored yet. The presence of a static octupole deformation in nuclei will enhance a possible permanent electric dipole moment, leading to a possible demonstration of parity violation. Purpose: To check whether static octupole deformation and octupole vibration in fusion give different results so that both situations could be experimentally disentangled. Method: Fusion cross sections are computed in the coupled-channel formalism making use of the ingoing-wave boundary conditions (IWBC) for the systems 16O+144Ba and 16O+224Ra . Results: Barrier distributions of the two considered schemes show slightly different patterns. In the case of 144Ba, the difference between them is negligible. For the 224Ra case, perceptible differences are found in correspondence with its larger octupole deformation. However, the possibility of disentangling both schemes is not guaranteed and it will depend on the available experimental accuracy and the strength of the octupole deformation. Conclusions: The measurement of barrier distributions could be a complementary probe to support the presence of octupole deformation.

  3. NUP98 fusion in human leukemia: dysregulation of the nuclear pore and homeodomain proteins.

    PubMed

    Nakamura, Takuro

    2005-07-01

    NUP98 is fused to a variety of partner genes, including abdominal B-like HOX, in human myeloid and T-cell malignancies via chromosomal translocation involving 11p15. NUP98 encodes a 98-kd nucleoporin that is a component of the nuclear pore complex and functions in nucleocytoplasmic transport, with its N-terminal GLFG repeats used as a docking site for karyopherins. Disruption of NUP98 may affect the nuclear pore function, and the abnormal expression and altered function of fusion partners may also be critical for leukemia development. Recent studies using mouse models expressing NUP98-HOX have confirmed its leukemogenic potential, and cooperative genes for NUP98-HOXA9 in leukemogenesis have been identified in these studies.Thus, the NUP98 chimera is a unique molecule that provides valuable information regarding nuclear pore function and the role of the homeobox protein in leukemogenesis/carcinogenesis.

  4. 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.

  5. Big fusion, little fusion

    NASA Astrophysics Data System (ADS)

    Chen, Frank; ddtuttle

    2016-08-01

    In reply to correspondence from George Scott and Adam Costley about the Physics World focus issue on nuclear energy, and to news of construction delays at ITER, the fusion reactor being built in France.

  6. Investigations on inertial confinement fusion at the Russian Federal Nuclear Center—VNIIEF

    NASA Astrophysics Data System (ADS)

    Garanin, S.; Kirillov, G. A.; Kochemasov, G. G.; Mkhitaryan, L. S.; Murugov, V. M.; Sukharev, S. A.; Zhidkov, N. V.

    2003-12-01

    Since 30 years already, the All-Russia Institute of Experimental Physics (VNIIEF) is engaged in investigations on the problem of inertial confinement fusion. The high-power laser facilities 'Iskra 5' (Kirillov G A et al 1990 Laser Particle Beams 8 827 31) and 'Luch' (Sukharev S A 3rd Int. Conf. on Solid State Lasers for Application to Inertial Confinement Fusion ed W H Lowdermilk Proc. SPIE 3492 12 24) were created and are operating now in the framework of this programme. The main lines of the work at these facilities are the investigation of the physics of thermonuclear targets and the development of laser technologies. This work resulted in the development of a project of the new generation facility 'Iskra-6'. This report presents the main results of these works carried out at Russian Federal Nuclear Center—VNIIEF in the period 1991 2002.

  7. 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.

  8. 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.

  9. Interfaces MATXS Cross-Section Libraries to Nuclear Transport Codes for Fusion Systems Analysis.

    1985-04-10

    Version: 00 TRANSX-CTR is a computer code that reads nuclear data from a library in MATXS format and produces transport tables with many discrete-ordinates (Sn) and diffusion codes. Tables can be produced for neutron, photon, or coupled transport. Options include adjoint tables, mixtures, self-shielding, group collapse, homogenization, thermal upscatter, prompt or steady-state fission, transport corrections, elastic removal corrections, and flexible response-function edits. The ability to prepare coupled tables and response edits for heating, damage, gasmore » production, and delayed activity makes TRANSX-CTR especially useful for fusion reactor studies.« less

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. The role of Z-pinch fusion transmutation of waste in the nuclear fuel cycle.

    SciTech Connect

    Smith, James Dean; Drennen, Thomas E.; Rochau, Gary Eugene; Martin, William Joseph; Kamery, William; Phruksarojanakun, Phiphat; Grady, Ryan; Cipiti, Benjamin B.; Wilson, Paul Philip Hood; Mehlhorn, Thomas Alan; Guild-Bingham, Avery; Tsvetkov, Pavel Valeryevich

    2007-10-01

    The resurgence of interest in reprocessing in the United States with the Global Nuclear Energy Partnership has led to a renewed look at technologies for transmuting nuclear waste. Sandia National Laboratories has been investigating the use of a Z-Pinch fusion driver to burn actinide waste in a sub-critical reactor. The baseline design has been modified to solve some of the engineering issues that were identified in the first year of work, including neutron damage and fuel heating. An on-line control feature was added to the reactor to maintain a constant neutron multiplication with time. The transmutation modeling effort has been optimized to produce more accurate results. In addition, more attention was focused on the integration of this burner option within the fuel cycle including an investigation of overall costs. This report presents the updated reactor design, which is able to burn 1320 kg of actinides per year while producing 3,000 MWth.

  15. 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.

  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. 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.

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

    PubMed Central

    Wang, Shunfang; Liu, Shuhui

    2015-01-01

    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. PMID:26703574

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. Low-Energy Fusion-Fission Dynamics of Heavy Nuclear Systems

    SciTech Connect

    Zagrebaev, Valery; Greiner, Walter

    2006-08-14

    A new approach is proposed for a unified description of strongly coupled deep-inelastic (DI) scattering, fusion, fission, and quasi-fission (QF) processes of heavy ion collisions. A unified driving-potential and a unified set of dynamic Langevin-type equations of motion are used in this approach. This makes it possible to perform a full (continuous) time analysis of the evolution of heavy nuclear systems, starting from the approaching stage, moving up to the formation of the compound nucleus or emerging into two final fragments. The calculated mass, charge, energy and angular distributions of the reaction products agree well with the corresponding experimental data for heavy and superheavy nuclear systems. Collisions of very heavy nuclei (such as 238U+248Cm) are investigated as an alternative way for production of superheavy elements. Large charge and mass transfer was found in these reactions due to the inverse (anti-symmetrizing) quasi-fission process leading to formation of surviving superheavy long-lived neutron-rich nuclei.

  11. 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.

  12. 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.

  13. Bubble fusion: Preliminary estimates

    SciTech Connect

    Krakowski, R.A.

    1995-02-01

    The collapse of a gas-filled bubble in disequilibrium (i.e., internal pressure {much_lt} external pressure) can occur with a significant focusing of energy onto the entrapped gas in the form of pressure-volume work and/or acoustical shocks; the resulting heating can be sufficient to cause ionization and the emission of atomic radiations. The suggestion that extreme conditions necessary for thermonuclear fusion to occur may be possible has been examined parametrically in terms of the ratio of initial bubble pressure relative to that required for equilibrium. In this sense, the disequilibrium bubble is viewed as a three-dimensional ``sling shot`` that is ``loaded`` to an extent allowed by the maximum level of disequilibrium that can stably be achieved. Values of this disequilibrium ratio in the range 10{sup {minus}5}--10{sup {minus}6} are predicted by an idealized bubble-dynamics model as necessary to achieve conditions where nuclear fusion of deuterium-tritium might be observed. Harmonic and aharmonic pressurizations/decompressions are examined as means to achieve the required levels of disequilibrium required to create fusion conditions. A number of phenomena not included in the analysis reported herein could enhance or reduce the small levels of nuclear fusions predicted.

  14. Adapting computational optimization concepts from aeronautics to nuclear fusion reactor design

    NASA Astrophysics Data System (ADS)

    Dekeyser, W.; Reiter, D.; Baelmans, M.

    2012-10-01

    Even on the most powerful supercomputers available today, computational nuclear fusion reactor divertor design is extremely CPU demanding, not least due to the large number of design variables and the hybrid micro-macro character of the flows. Therefore, automated design methods based on optimization can greatly assist current reactor design studies. Over the past decades, "adjoint methods" for shape optimization have proven their virtue in the field of aerodynamics. Applications include drag reduction for wing and wing-body configurations. Here we demonstrate that also for divertor design, these optimization methods have a large potential. Specifically, we apply the continuous adjoint method to the optimization of the divertor geometry in a 2D poloidal cross section of an axisymmetric tokamak device (as, e.g., JET and ITER), using a simplified model for the plasma edge. The design objective is to spread the target material heat load as much as possible by controlling the shape of the divertor, while maintaining the full helium ash removal capabilities of the vacuum pumping system.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Achievement of high nuclear spin polarization using lanthanides as low-temperature NMR relaxation agents.

    PubMed

    Peat, David T; Horsewill, Anthony J; Köckenberger, Walter; Perez Linde, Angel J; Gadian, David G; Owers-Bradley, John R

    2013-05-28

    Many approaches are now available for achieving high levels of nuclear spin polarization. One of these methods is based on the notion that as the temperature is reduced, the equilibrium nuclear polarization will increase, according to the Boltzmann distribution. The main problem with this approach is the length of time it may take to approach thermal equilibrium at low temperatures, since nuclear relaxation times (characterized by the spin-lattice relaxation time T1) can become very long. Here, we show, by means of relaxation time measurements of frozen solutions, that selected lanthanide ions, in the form of their chelates with DTPA, can act as effective relaxation agents at low temperatures. Differential effects are seen with the different lanthanides that were tested, holmium and dysprosium showing highest relaxivity, while gadolinium is ineffective at temperatures of 20 K and below. These observations are consistent with the known electron-spin relaxation time characteristics of these lanthanides. The maximum relaxivity occurs at around 10 K for Ho-DTPA and 20 K for Dy-DTPA. Moreover, these two agents show only modest relaxivity at room temperature, and can thus be regarded as relaxation switches. We conclude that these agents can speed up solid state NMR experiments by reducing the T1 values of the relevant nuclei, and hence increasing the rate at which data can be acquired. They could also be of value in the context of a simple low-cost method of achieving several-hundred-fold improvements in polarization for experiments in which samples are pre-polarized at low temperatures, then rewarmed and dissolved immediately prior to analysis.

  20. West European magnetic confinement fusion research

    SciTech Connect

    McKenney, B.L.; McGrain, M. . Foreign Applied Sciences Assessment Center); Hazeltine, R.D. . Inst. for Fusion Studies); Gentle, K.W. ); Hogan, J.T. ); Porkolab, M. . Dept. of Physics); Sigmar

    1990-01-01

    This report presents a technical assessment and review of the West European program in magnetic confinement fusion by a panel of US scientists and engineers active in fusion research. Findings are based on the scientific and technical literature, on laboratory reports and preprints, and on the personal experiences and collaborations of the panel members. Concerned primarily with developments during the past 10 years, from 1979 to 1989, the report assesses West European fusion research in seven technical areas: tokamak experiments; magnetic confinement technology and engineering; fusion nuclear technology; alternate concepts; theory; fusion computations; and program organization. The main conclusion emerging from the analysis is that West European fusion research has attained a position of leadership in the international fusion program. This distinction reflects in large measure the remarkable achievements of the Joint European Torus (JET). However, West European fusion prominence extends beyond tokamak experimental physics: the program has demonstrated a breadth of skill in fusion science and technology that is not excelled in the international effort. It is expected that the West European primacy in central areas of confinement physics will be maintained or even increased during the early 1990s. The program's maturity and commitment kindle expectations of dramatic West European advances toward the fusion energy goal. For example, achievement of fusion breakeven is expected first in JET, before 1995.

  1. In search of nuclear fusion in electrolytic cells and in metal/gas systems

    NASA Astrophysics Data System (ADS)

    McCracken, D. R.; Paquette, J.; Boniface, H. A.; Graham, W. R. C.; Johnson, R. E.; Briden, N. A.; Cross, W. G.; Arneja, A.; Tennant, D. C.; Lone, M. A.; Buyers, W. J. L.; Chambers, K. W.; McIlwain, A. K.; Attas, E. M.; Dutton, R.

    1990-06-01

    It has been reported recently in the literature that unexpected thermal and nuclear effects (production of excess heat, neutrons, γ-rays, and tritium) can occur during the electrolysis of heavy water at palladium or titanium electrodes, or during temperature and pressure cycling of the titanium/deuterium gas system. We have attempted to reproduce some of these experiments. A variety of electrochemical cells having palladium cathodes in the form of wires, tubes, sheets, and rods have been used to electrolyze heavy water containing 0.1 mol.dm-3 LiOH, 0.1 mol.dn-3 LiOD or 0.5 mol.dm-3 D3PO4. Current densities of up to 200 mA.cm-2 were applied. The mass of the palladium cathodes covered the range from 1-40 grams and the surface area varied from 8-140 cm2. Neutron detection systems with low constant backgrounds were used to search for neutron emission during electrolysis. These included3He- and10BF3-based detectors. After running some of the cells for more than 30 days, no neutron emission above background could be detected. This puts upper limits of 0.5 s-1 and 2×10-23 fus. D-D.s-1 on the neutron emission and the fusion rate, respectively. A sensitive and accurate heat-flow calorimeter was built and used to monitor the energy balance of some of the cells during electrolysis. No unexpected heat effects were observed. This puts an upper limit of 0.13 W.cm-3 on the specific excess power. No enrichment of the electrolyte in tritium was evident after electrolysis. Experiments were also performed with the titanium/ deuterium gas system. These consisted of exposing titanium metal to a deuterium gas pressure of 40 atmospheres, lowering the temperature to -196°C, releasing the pressure and gradually warming the titanium to room temperature. No neutron emission above background was observed during these experiments, which puts upper limits of 0.5 s-1 and 4×10-25 fus.D-D.s-1 on the neutron emission and fusion rate, respectively.

  2. 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.

  3. Fracture evaluations of fusion line cracks in nuclear pipe bimetallic welds

    SciTech Connect

    Scott, P.; Francini, R.; Rahman, S.; Rosenfield, A.; Wilkowski, G.

    1995-04-01

    In both BWRs and PWRs there are many locations where carbon steel pipe or components are joined to stainless steel pipe or components with a bimetallic weld. The objective of the research described in this report was to assess the accuracy of current fracture analyses for the case of a crack along a carbon steel to austenitic weld fusion line. To achieve the program objective, material property data and data from a large-diameter pipe fracture experiment were developed to assess current analytical methods. The bimetallic welds evaluated in this program were bimetallic welds obtained from a cancelled Combustion Engineering plant. The welds joined sections of the carbon steel cold-leg piping system to stainless steel safe ends that were to be welded to stainless steel pump housings. The major conclusion drawn as a result of these efforts was that the fracture behavior of the bimetallic weld evaluated in this program could be evaluated with reasonable accuracy using the strength and toughness properties of the carbon steel pipe material in conjunction with conventional elastic-plastic fracture mechanics or limit-load analyses. This may not be generally true for all bimetallic welds, as discussed in this report.

  4. 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.

  5. 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.

  6. Evidence for an inhibitory feedback loop regulating simian virus 40 large T-antigen fusion protein nuclear transport.

    PubMed Central

    Seydel, U; Jans, D A

    1996-01-01

    Nuclear protein import is central to eukaryotic cell function. It is dependent on ATP, temperature and cytosolic factors, and requires specific targeting sequences called nuclear localization signals (NLSs). Nuclear import kinetics was studied in vitro using digitonin-permeabilized cells of the HTC rat hepatoma cell line and a fluorescently labelled beta-galactosidase fusion protein carrying amino acids 111-135 of the simian virus 40 large T-antigen (T-ag), including the NLS. Nuclear accumulation was rapid, reaching steady-state after about 80 min at 37 degrees C (t1/2 at about 17 min). Surprisingly, maximal nuclear concentration was found to be directly proportional to the concentration of the cytosolic extract and of cytoplasmic T-ag protein. Neither preincubation of cells for 1 h at 37 degrees C before the addition of T-ag protein nor the addition of fresh transport medium after 1 h and continuation of the incubation for another hour affected the maximal nuclear concentration. If cells were allowed to accumulate T-ag protein for 1 h before the addition of fresh transport medium containing different concentrations of T-ag protein and incubated for a further hour, the maximal nuclear concentration did not change unless the concentration of T-ag protein in the second transport mixture exceeded that in the first, in which case the nuclear concentration increased. Nuclear import of T-ag thus appeared (i) to be strictly unidirectional over 2 h at 37 degrees C and (ii) to be regulated by an inhibitory feedback loop, whereby the cytosolic concentration of protein appears to determine directly the precise end point of nuclear accumulation. This study represents the first characterization of this previously undescribed mechanism of regulation of nuclear protein import. PMID:8670127

  7. 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.

  8. 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.

  9. Nuclear localization and hepatic zonation of rat "spot 14" protein: immunohistochemical investigation employing anti-fusion protein antibodies.

    PubMed

    Kinlaw, W B; Tron, P; Friedmann, A S

    1992-12-01

    S14 protein and mRNA levels are rapidly regulated by hormones and diet. We have purified a 45-Kd fusion protein from lysates of transformed E. coli that includes the entire S14 polypeptide. Affinity-purified rabbit anti-fusion protein antibodies were used in immunohistochemistry to determine the distribution of S14 protein across the hepatic lobule, and to reassess its intracellular location. In hyperthyroid liver, S14 protein clustered near the central venous zone, and was not detectable in the periportal area of the acinus. The signal in perivenous hepatocytes was primarily nuclear in location, in stark contrast to previous subcellular fractionation studies. Visualization of identical hepatic distribution and subcellular localization employing anti-synthetic peptide antiserum provided evidence for the specificity of the immunostaining, as did attenuation of the signal by preincubation of the antibody with its antigen. No staining was observed in sections of heart or hypothyroid liver, as expected from the low levels of S14 protein in those tissues. The data indicate that induction of S14 protein expression by T3 occurs through enhanced expression by perivenous hepatocytes, rather than by recruitment of cells in more peripheral zones of the lobule. Nuclear localization of the S14 protein by immunohistochemistry suggests that it is lost from nuclei during standard fractionation procedures, and prompts consideration of a role for S14 in regulation of nuclear structure and/or function.

  10. 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. PMID:27114368

  11. 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.

  12. Nuclear Diagnostics of Implosion and Fusion Burn at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Barnes, Cris W.

    2005-04-01

    The National Ignition Facility will be the most revolutionary scientific facility of the early 21st century. The ability to drive inertial confinement fusion implosions with over 1 MegaJoule of laser energy will lead to tremendous advances in the study of fusion burn, hydrodynamic mix, and other research areas. Diagnostics of the fusion burn will be central to these studies. Los Alamos is leading efforts to develop three main fusion product diagnostic systems for the NIF: a Neutron Imaging System using pinhole-apertures; a burn or reaction history diagnostic that measures the DT fusion gammas using a Gas Cerenkov Detector; and a set of Neutron Scintillators to measure relative fusion yield and ion temperature, possibly with time dependence. All these systems are presently under development using implosions at the OMEGA Laser at the University of Rochester. An overview of the requirements and systems proposed for NIF will be presented. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W- 7405-ENG-36.

  13. 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.

  14. 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.

  15. 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!!!

  16. 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!!!

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Future of Inertial Fusion Energy

    SciTech Connect

    Nuckolls, J H; Wood, L L

    2002-09-04

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

  4. 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.

  5. 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.

  6. Two generic concepts for space propulsion based on thermal nuclear fusion

    NASA Astrophysics Data System (ADS)

    Gabrielli, R. A.; Petkow, D.; Herdrich, G.; Laufer, R.; Röser, H.-P.

    2014-08-01

    In the present work, two different concepts for fusion based space propulsion are compared. While the first concept is based solely on propulsion by hypothetic ejection of fusion products and hence may be called ash drive, the second one uses an additional coolant for thrust enhancement. Since this coolant was initially assumed to be gaseous and since it is doing most of the propulsion work, the name of “working gas drive” has been proposed. Propulsive characteristics for both types are evaluated for four fusion reactant couples (D-T; D-3He; 3He-3He; 11B-p). In working gas drives, only hydrogen is considered as coolant due to its exceptionally good caloric and propulsive properties. The results of comparative studies show that while ash drives excel working gas drives in terms of specific impulse the latter yield considerably more thrust than ash drives. Another major drawback of the ash drives is relatively small thrust efficiencies. The plasma power has to be disposed of nearly entirely as waste heat leading to prohibitive radiator masses.

  7. 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

  8. 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.

  9. An efficient nonclassical quadrature for the calculation of nonresonant nuclear fusion reaction rate coefficients from cross section data

    NASA Astrophysics Data System (ADS)

    Shizgal, Bernie D.

    2016-08-01

    Nonclassical quadratures based on a new set of half-range polynomials, Tn(x) , orthogonal with respect to w(x) =e - x - b /√{ x } for x ∈ [ 0 , ∞) are employed in the efficient calculation of the nuclear fusion reaction rate coefficients from cross section data. The parameter b = B /√{kB T } in the weight function is temperature dependent and B is the Gamow factor. The polynomials Tn(x) satisfy a three term recurrence relation defined by two sets of recurrence coefficients, αn and βn. These recurrence coefficients define in turn the tridiagonal Jacobi matrix whose eigenvalues are the quadrature points and the weights are calculated from the first components of the eigenfunctions. For nonresonant nuclear reactions for which the astrophysical function can be expressed as a lower order polynomial in the relative energy, the convergence of the thermal average of the reactive cross section with this nonclassical quadrature is extremely rapid requiring in many cases 2-4 quadrature points. The results are compared with other libraries of nuclear reaction rate coefficient data reported in the literature.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-09-01

    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.

  16. 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.

  17. 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.

  18. 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…

  19. 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.…

  20. 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.

  1. 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.

  2. Nuclear fuel cycle analysis of the SABR fusion-fission hybrid transmutation reactor

    NASA Astrophysics Data System (ADS)

    Sommer, Chris; Stacey, Weston; Petrovic, Bojan

    2009-11-01

    Various fuel cycles have been designed and analyzed for the Subcritical Advanced Burner Reactor (SABR). SABR is a sodium cooled fast reactor fueled with transuranics (TRU) from spent fuel of light water reactors and driven by a tokamak fusion neutron source based on ITER physics and technology. SABR employs a four batch fuel cycle using an out-to-in shuffling pattern, with the fuel being reprocessed at the end of each cycle. The reprocessing method assumes recovery rates of 99.9% of the actinides and 0.1% of the fission products remain in the recycled fuel. The reprocessing fuel cycles were analyzed to find an optimal cycle length in terms of burn up, power distribution, and materials limitations. Fuel cycles are analyzed using CEA's ERANOS2.0 code, with fuel residence times limited by radiation damage at 100, 150 and 200 dpa.

  3. 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.

  4. 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

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

    SciTech Connect

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

    2013-05-15

    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.

  6. 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

  7. 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.

  8. The Role of Plastids in the Expression of Nuclear Genes for Thylakoid Proteins Studied with Chimeric [beta]-Glucuronidase Gene Fusions.

    PubMed Central

    Bolle, C.; Sopory, S.; Lubberstedt, T.; Klosgen, R. B.; Herrmann, R. G.; Oelmuller, R.

    1994-01-01

    We have analyzed plastid and nuclear gene expression in tobacco seedlings using the carotenoid biosynthesis inhibitor nor-flurazon. mRNA levels for three nuclear-encoded chlorophyll-binding proteins of photosystem I and photosystem II (CAB I and II and the CP 24 apoprotein) are no longer detectable in photobleached seedlings, whereas those for other components of the thylakoid membrane (the 33- and 23-kD polypeptides and Rieske Fe/S polypeptide) accumulate to some extent. Transgenic tobacco seedlings with promoter fusions from genes for thylakoid membrane proteins exhibit a similar expression behavior: a CAB-[beta]-glucuronidase (GUS) gene fusion is not expressed in herbicide-treated seedlings, whereas PC-, FNR-, PSAF-, and ATPC-promoter fusions are expressed, although at reduced levels. All identified segments in nuclear promoters analyzed that have been shown to respond to light also respond to photodamage to the plastids. Thus, the regulatory signal pathways either merge prior to gene regulation or interact with closely neighboring cis elements. These results indicate that plastids control nuclear gene expression via different and gene-specific cis-regulatory elements and that CAB gene expression is different from the expression of the other genes tested. Finally, a plastid-directing import sequence from the maize Waxy gene is capable of directing the GUS protein into the photodamaged organelle. Therefore, plastid import seems to be functional in photobleached organelles. PMID:12232290

  9. Magneto-Inertial Fusion

    DOE PAGES

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

    2015-11-17

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

  10. 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.

  11. The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries

    NASA Astrophysics Data System (ADS)

    Arnould, M.; Goriely, S.; Takahashi, K.

    2007-09-01

    The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of various metallicities, as well as in the solar system. A very large amount of nuclear information is necessary in order to model the r-process. This concerns the static characteristics of a large variety of light to heavy nuclei between the valley of stability and the vicinity of the neutron-drip line, as well as their beta-decay branches or their reactivity. Fission probabilities of very neutron-rich actinides have also to be known in order to determine the most massive nuclei that have a chance to be involved in the r-process. Even the properties of asymmetric nuclear matter may enter the problem. The enormously challenging experimental and theoretical task imposed by all these requirements is reviewed, and the state-of-the-art development in the field is presented. Nuclear-physics-based and astrophysics-free r-process models of different levels of sophistication have been constructed over the years. We review their merits and their shortcomings. The ultimate goal of r-process studies is clearly to identify realistic sites for the development of the r-process. Here too, the challenge is enormous, and the solution still eludes us. For long, the core collapse supernova of massive stars has been envisioned as the privileged r-process location. We present a brief summary of the one- or multidimensional spherical or non-spherical explosion simulations available to-date. Their predictions are confronted with the requirements imposed to obtain an r-process. The possibility of r-nuclide synthesis during the decompression of the matter of neutron stars following their merging is also discussed. Given the uncertainties remaining on the astrophysical r-process site and on the involved nuclear physics, any confrontation between predicted r

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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)

  17. Competition between fusion and quasifission in a heavy fusing system: Diffusion of nuclear shapes through a dynamical collective potential energy landscape

    SciTech Connect

    Diaz-Torres, Alexis

    2006-12-15

    A theory of the competition between fusion and quasifission in a heavy fusing system is proposed, which is based on a master equation and the two-center shell model. Fusion and quasifission arise from a diffusion process in an ensemble of nuclear shapes, each of which evolves toward the thermal equilibrium. The fusing system moves on a dynamical (time-dependent) collective potential energy surface that is initially diabatic and gradually becomes adiabatic. Calculations for several reactions leading to {sup 256}No are performed within a simplified two-dimensional model. Among other important conclusions, the results indicate that (i) the diabatic effects play a very important role in the onset of fusion hindrance for heavy systems and (ii) very asymmetric reactions induced by closed-shell nuclei seem to be the best suited to synthesize the heaviest compound nuclei.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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!!!

  3. 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.

  4. 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

    2012-01-01

    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.

  5. Effects of the time interval between fusion and activation on in vitro rabbit nuclear transfer efficiency when nuclear donor cells are derived from older adults.

    PubMed

    Cervera, R P; Garcia-Ximénez, F

    2004-05-01

    Cloning older adult rabbits can serve as a model in animal breeding, biodiversity preservation and in human therapeutic cloning. To establish the required exposure time of fibroblasts from these kind of animals to reprogramming factors, in the present study three different time intervals between fusion and activation were tested (30 min, 30-ADF group; 60 min, 60-ADF group; and 90 min, 90-ADF group). Vitrified epithelial fibroblasts derived from four older adult rabbit females (D1, D2, D3 and D4) and cultured from passages 0 to 4 were used as nuclear donors. Nuclear status of reconstructed embryos was not evaluated. No differences were observed in blastocyst rate (30-ADF 21% vs 60-ADF 19% vs 90-ADF 18%). Differences in hatching rates did not reach significance (30-ADF 11% vs 60-ADF 18% vs 90-ADF 18%). However, in the 60- and 90-ADF groups, embryos reached the blastocyst stage earlier than in the 30-ADF group (day 4: 40% and 50% vs 8%; p > 0.05). Moreover, the quality of blastocysts (good vs poor) was lower in the 30-ADF group (good: 30-ADF 38% vs 60-ADF 90% vs 90-ADF 90%; p > 0.05). Overall, these results suggest an unfavourable effect of the shortest exposure time tested (30 min). Differences between specimen origins were detected (blastocyst and hatching rates: D2 (26%; 25%) and D4 (25%; 27%) vs D1 (10%; 11%) and D3 (12%; 12%)), but significance were not reached. Effect of culture passage was not detected in any parameter studied. PMID:15460108

  6. '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. PMID:26746203

  7. '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.

  8. Applications of (n, p) and (n, α) reactions and a backscattering technique to fusion reactor materials, archeometry, and nuclear spectroscopy

    NASA Astrophysics Data System (ADS)

    Fink, D.; Biersack, J. P.; Grawe, H.; Riederer, J.; Müller, K.; Henkelmann, R.

    1980-01-01

    Depth profiles of He, Li and B are determined by 3He(n, p)T, 6Li(n, α)T and 10B(n, α) 7Li reactions with thermal neutrons at the high flux reactor of the ILL, Grenoble. The behaviour of Li in Be is examined with respect to future fusion reactors. Range profiles of 70-300 keV Li + are measured and found to agree with theory based on Lindhard-Scharff electronic stopping and Molière potential. Li becomes mobile in Be above 100°C. Further, B and Li distributions in glaze of ancient pottery are examined for studying ancient production techniques. It is found that all examined samples (of Islamic, Thai and North American provenience) show Li and B concentrations which are enriched relative to the original material. Li is mostly depleted in a surface layer of 0.1-1.6 μm half-width due to various burning conditions. In experimental nuclear physics, gas cells are now often replaced by thin foils with implanted gas. In many cases the knowledge of the concentration profile is required, and is presently evaluated for the case of 3He in Ni and Au with the (n, p) reaction. This is compared to results obtained by a special Rutherford backscattering technique yielding good agreement.

  9. Spinal fusion

    MedlinePlus

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

  10. 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

  11. Nuclear measurements of fuel-shell mix in inertial confinement fusion implosions at OMEGAa)

    NASA Astrophysics Data System (ADS)

    Rygg, J. R.; Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Delettrez, J. A.; Glebov, V. Yu.; Goncharov, V. N.; Meyerhofer, D. D.; Radha, P. B.; Regan, S. P.; Sangster, T. C.

    2007-05-01

    Direct drive spherical implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have shown that increased capsule convergence results in increased susceptibility to fuel-shell mix. Mix results from saturation of the Rayleigh-Taylor instability, leading to small-scale, turbulent eddies and atomic-level mixing of the high-density compressed shell with hot, low-density fuel from the core. To sensitively probe the extent of mix, nuclear yields were measured from implosions of capsules filled with pure He3. The plastic capsule shell contains a deuterated plastic (CD) layer either on the inner surface or offset from the inner surface by 1μm. Mixing of D from the shell with hot He3 in the core is necessary to produce 14.7MeV DHe3 protons in such capsules. DHe3-proton spectral measurements have been used to constrain the amount of mix at shock time, to demonstrate that some of the fuel mixes with the offset CD layer, and that capsules with a higher initial fill density or thicker shell are less susceptible to the effects of mix.

  12. Magnetic fusion and project ITER

    SciTech Connect

    Park, H.K.

    1992-01-01

    It has already been demonstrated that our economics and international relationship are impacted by an energy crisis. For the continuing prosperity of the human race, a new and viable energy source must be developed within the next century. It is evident that the cost will be high and will require a long term commitment to achieve this goal due to a high degree of technological and scientific knowledge. Energy from the controlled nuclear fusion is a safe, competitive, and environmentally attractive but has not yet been completely conquered. Magnetic fusion is one of the most difficult technological challenges. In modem magnetic fusion devices, temperatures that are significantly higher than the temperatures of the sun have been achieved routinely and the successful generation of tens of million watts as a result of scientific break-even is expected from the deuterium and tritium experiment within the next few years. For the practical future fusion reactor, we need to develop reactor relevant materials and technologies. The international project called International Thermonuclear Experimental Reactor (ITER)'' will fulfill this need and the success of this project will provide the most attractive long-term energy source for mankind.

  13. Magnetic fusion and project ITER

    SciTech Connect

    Park, H.K.

    1992-09-01

    It has already been demonstrated that our economics and international relationship are impacted by an energy crisis. For the continuing prosperity of the human race, a new and viable energy source must be developed within the next century. It is evident that the cost will be high and will require a long term commitment to achieve this goal due to a high degree of technological and scientific knowledge. Energy from the controlled nuclear fusion is a safe, competitive, and environmentally attractive but has not yet been completely conquered. Magnetic fusion is one of the most difficult technological challenges. In modem magnetic fusion devices, temperatures that are significantly higher than the temperatures of the sun have been achieved routinely and the successful generation of tens of million watts as a result of scientific break-even is expected from the deuterium and tritium experiment within the next few years. For the practical future fusion reactor, we need to develop reactor relevant materials and technologies. The international project called ``International Thermonuclear Experimental Reactor (ITER)`` will fulfill this need and the success of this project will provide the most attractive long-term energy source for mankind.

  14. 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

  15. 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.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, R. C.

    2009-07-01

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

  18. Development of tokamak experiment technology: A study on the nuclear fusion reactor

    NASA Astrophysics Data System (ADS)

    Lee, Kwang Won; Hwang, Chul Kew; In, Sang Ryul; Kim, Sung Kyu; Oh, Byung Hoon; Jeong, Seung Ho; Hong, Bong Guen; Yoon, Jae Sung; Yoon, Byung Joo; Song, Woo Sup

    1994-07-01

    Overall test operation of KT-1 tokamak has been done with the modified power supplies and constructed plasma position feedback control system. The achieved plasma parameters of KT-1 are Ip (plasma current) greater than 15 kA (9ms) and Td (plasma current sustaining time) greater than 12 ms (7.5 kA) until now. Instrumentations for the carbonization/boronization are also equipped and applied to the first boronization of invessel components of KT-1 tokamak. As a preliminary treatment of the 1st wall of tokamak vacuum torus, RG discharge cleaning has been done. Plasma qualities have been improved by discharge cleaning. In addition, helicon plasma device is designed succeeding exploitation of the first wall conditioning program which are all for the development of conditioning technology of 1st wall facing the plasma. As a part of the development program on the plasma monitoring technologies, conceptual design study on the FIR interferometer- polarimeter is accomplished. Parallel to these experimental activities, an effort has been made in designing the operating scenario of poloidal field system of KT-2 tokamak.

  19. Establishment of an Institute for Fusion Studies

    NASA Astrophysics Data System (ADS)

    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. 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.

  1. 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.

  2. Status of fusion maintenance

    SciTech Connect

    Fuller, G.M.

    1984-01-01

    Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission.

  3. Some new inequalities for continuous fusion frames and fusion pairs.

    PubMed

    Zhang, Wei; Li, Yun-Zhang

    2016-01-01

    This paper addresses continuous fusion frames and fusion pairs which are extensions of discrete fusion frames and continuous frames. The study of equalities and inequalities for various frames has seen great achievements. In this paper, using operator methods we establish some new inequalities for continuous fusion frames and fusion pairs. Our results extend and improve ones obtained by Balan, Casazza and Găvruţa. PMID:27652173

  4. 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.

  5. 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.

  6. 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

    2013-07-01

    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.

  7. A fusion protein of the estrogen receptor (ER) and nuclear receptor corepressor (NCoR) strongly inhibits estrogen-dependent responses in breast cancer cells.

    PubMed

    Chien, P Y; Ito, M; Park, Y; Tagami, T; Gehm, B D; Jameson, J L

    1999-12-01

    Nuclear receptor corepressor (NCoR) mediates repression (silencing) of basal gene transcription by nuclear receptors for thyroid hormone and retinoic acid. The goal of this study was to create novel estrogen receptor (ER) mutants by fusing transferable repressor domains from the N-terminal region of NCoR to a functional ER fragment. Three chimeric NCoR-ER proteins were created and shown to lack transcriptional activity. These fusion proteins silenced basal transcription of the ERE2-tk-Luc reporter gene and inhibited the activity of co-transfected wild-type ER (wtER), indicating that they possess dominant negative activity. One of the fusion proteins (CDE-RD1), containing the ER DNA-binding and ligand-binding domains linked to the NCoR repressor domain (RD1), was selected for detailed examination. Its hormone affinity, intracellular localization, and level of expression in transfected cells were similar to wtER, and it bound to the estrogen response element (ERE) DNA in gel shift assays. Glutathione-S-transferase pull-down assays showed that CDE-RD1 retains the ability to bind to steroid receptor coactivator-1. Introduction of a DNA-binding domain mutation into the CDE-RD1 fusion protein eliminated silencing and dominant negative activity. Thus, the RD1 repressor domain prevents transcriptional activation despite the apparent ability of CDE-RD1 to bind DNA, ligand, and coactivators. Transcriptional silencing was incompletely reversed by trichostatin A, suggesting a histone deacetylase-independent mechanism for repression. CDE-RD1 inhibited ER-mediated transcription in T47D and MDA-MB-231 breast cancer cells and repressed the growth of T47D cells when delivered to the cells by a retroviral vector. These ER-NCoR fusion proteins provide a novel means for inhibiting ER-mediated cellular responses, and analogous strategies could be used to create dominant negative mutants of other transcription factors.

  8. 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.

  9. 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;…

  10. 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.

  11. 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

  12. 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. PMID:27441240

  13. 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.

  14. 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

  15. 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

  16. (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)

  17. 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.

  18. UK fusion breakthrough revealed at last

    NASA Astrophysics Data System (ADS)

    Evans, Roger

    2010-03-01

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

  19. The fusion breeder

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1982-10-01

    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 U.S. fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the U.S. fusion program and the U.S. nuclear energy program. There is wide agreement that many approaches will work and will produce fuel for five equal-sized LWRs, and some approach as many as 20 LWRs at electricity costs within 20% of those at today's price of uranium (30/lb of U3O8). The blankets designed to suppress fissioning, called symbiotes, fusion fuel factories, or just fusion breeders, will have safety characteristics more like pure fusion reactors and will support as many as 15 equal power LWRs. The blankets designed to maximize fast fission of fertile material will have safety characteristics more like fission reactors and will support 5 LWRs. This author strongly recommends development of the fission suppressed blanket type, a point of view not agreed upon by everyone. There is, however, wide agreement that, to meet the market price for uranium which would result in LWR electricity within 20% of today's cost with either blanket type, fusion components can cost severalfold more than would be allowed for pure fusion to meet the goal of making electricity alone at 20% over today's fission costs. Also widely agreed is that the critical-path-item for the fusion breeder is fusion development itself; however, development of fusion breeder specific items (blankets, fuel cycle) should be started now in order to have the fusion breeder by the time the rise in uranium prices forces other more costly choices.

  20. 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.

  1. Laser erosion diagnostics of plasma facing materials with displacement sensors and their application to safeguard monitors to protect nuclear fusion chambers

    NASA Astrophysics Data System (ADS)

    Kasuya, Koichi; Motokoshi, Shinji; Taniguchi, Seiji; Nakai, Mitsuo; Tokunaga, Kazutoshi; Mroz, Waldemar; Budner, Boguslaw; Korczyc, Barbara

    2015-02-01

    Tungsten and SiC are candidates for the structural materials of the nuclear fusion reactor walls, while CVD poly-crystal diamond is candidate for the window material under the hazardous fusion stresses. We measured the surface endurance strength of such materials with commercial displacement sensors and our recent evaluation method. The pulsed high thermal input was put into the material surfaces by UV lasers, and the surface erosions were diagnosed. With the increase of the total number of the laser shots per position, the crater depth increased gradually. The 3D and 2D pictures of the craters were gathered and compared under various experimental conditions. For example, the maximum crater depths were plotted as a function of shot accumulated numbers, from which we evaluated the threshold thermal input for the surface erosions to be induced. The simple comparison-result showed that tungsten was stronger roughly two times than SiC. Then we proposed how to monitor the surface conditions of combined samples with such diamonds coated with thin tungsten layers, when we use such samples as parts of divertor inner walls, fusion chamber first walls, and various diagnostic windows. We investigated how we might be able to measure the inner surface erosions with the same kinds of displacement sensors. We found out the measurable maximum thickness of such diamond which is useful to monitor the erosion. Additionally we showed a new scheme of fusion reactor systems with injectors for anisotropic pellets and heating lasers under the probable use of W and/or SiC.

  2. 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.

  3. Does the Sun work as a nuclear fusion amplifier of planetary tidal forcing? A proposal for a physical mechanism based on the mass-luminosity relation

    NASA Astrophysics Data System (ADS)

    Scafetta, Nicola

    2012-06-01

    Numerous empirical evidences suggest that planetary tides may influence solar activity. In particular, it has been shown that: (1) the well-known 11-year Schwabe sunspot number cycle is constrained between the spring tidal period of Jupiter and Saturn, ˜9.93 year, and the tidal orbital period of Jupiter, ˜11.86 year, and a model based on these cycles can reconstruct solar dynamics at multiple time scales (Scafetta, in press); (2) a measure of the alignment of Venus, Earth and Jupiter reveals quasi 11.07-year cycles that are well correlated to the 11-year Schwabe solar cycles; and (3) there exists a 11.08 year cyclical recurrence in the solar jerk-shock vector, which is induced mostly by Mercury and Venus. However, Newtonian classical physics has failed to explain the phenomenon. Only by means of a significant nuclear fusion amplification of the tidal gravitational potential energy dissipated in the Sun, may planetary tides produce irradiance output oscillations with a sufficient magnitude to influence solar dynamo processes. Here we explain how a first order magnification factor can be roughly calculated using an adaptation of the well-known mass-luminosity relation for main-sequence stars similar to the Sun. This strategy yields a conversion factor between the solar luminosity and the potential gravitational power associated to the mass lost by nuclear fusion: the average estimated amplification factor is A≈4.25×106. We use this magnification factor to evaluate the theoretical luminosity oscillations that planetary tides may potentially stimulate inside the solar core by making its nuclear fusion rate oscillate. By converting the power related to this energy into solar irradiance units at 1 AU we find that the tidal oscillations may be able to theoretically induce an oscillating luminosity increase from 0.05-0.65 W/m2 to 0.25-1.63 W/m2, which is a range compatible with the ACRIM satellite observed total solar irradiance fluctuations. In conclusion, the Sun

  4. 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.

  5. 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.

  6. Improvements of image fusion methods

    NASA Astrophysics Data System (ADS)

    Ben-Shoshan, Yotam; Yitzhaky, Yitzhak

    2014-03-01

    Fusion of images from different imaging modalities, obtained by conventional fusion methods, may cause artifacts, including destructive superposition and brightness irregularities, in certain cases. This paper proposes two methods for improving image multimodal fusion quality. Based on the finding that a better fusion can be achieved when the images have a more positive correlation, the first method is a decision algorithm that runs at the preprocessing fusion stage and determines whether a complementary gray level of one of the input images should be used instead of the original one. The second method is suitable for multiresolution fusion, and it suggests choosing only one image from the lowest-frequency sub-bands in the pyramids, instead of combining values from both sub-bands. Experimental results indicate that the proposed fusion enhancement can reduce fusion artifacts. Quantitative fusion quality measures that support this conclusion are shown.

  7. 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.

  8. 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.

  9. Relapsed APL patient with variant NPM-RARalpha fusion responded to arsenic trioxide-based therapy and achieved long-term survival.

    PubMed

    Chen, Yan; Gu, Ling; Zhou, Chenyan; Wu, Xueqiang; Gao, Ju; Li, Qiang; Zhu, Yiping; Jia, Cangsong; Ma, Zhigui

    2010-05-01

    The t(5;17)/NPM-RARalpha is the second variant chromosomal translocation in acute promyelocytic leukemia (APL) to be characterized and also the second most plentiful variant translocation. So far, there is a lack of information on the effectiveness of arsenic trioxide (ATO) in relapsed APL with variant RARalpha chimera including t(5;17)/NPM-RARalpha. We report here a long-term survived APL patient with variant NPM-RARalpha fusion who relapsed four times and each time responded well to ATO or ATO-based re-induction therapy. The patient had received a total of more than 3,500 mg of ATO, but showed no obvious arsenic-related toxicities. This case illustrates the long-term efficiency and safety of ATO-based therapy not only in newly diagnosed APL, but also in relapsed APL including those with variant translocations.

  10. Frontier of Fusion Research: Path to the Steady State Fusion Reactor by Large Helical Device

    NASA Astrophysics Data System (ADS)

    Motojima, Osamu

    2006-12-01

    The ITER, the International Thermonuclear Experimental Reactor, which will be built in Cadarache in France, has finally started this year, 2006. Since the thermal energy produced by fusion reactions divided by the external heating power, i.e., the Q value, will be larger than 10, this is a big step of the fusion research for half a century trying to tame the nuclear fusion for the 6.5 Billion people on the Earth. The source of the Sun's power is lasting steadily and safely for 8 Billion years. As a potentially safe environmentally friendly and economically competitive energy source, fusion should provide a sustainable future energy supply for all mankind for ten thousands of years. At the frontier of fusion research important milestones are recently marked on a long road toward a true prototype fusion reactor. In its own merits, research into harnessing turbulent burning plasmas and thereby controlling fusion reaction, is one of the grand challenges of complex systems science. After a brief overview of a status of world fusion projects, a focus is given on fusion research at the National Institute for Fusion Science (NIFS) in Japan, which is playing a role of the Inter University Institute, the coordinating Center of Excellence for academic fusion research and by the Large Helical Device (LHD), the world's largest superconducting heliotron device, as a National Users' facility. The current status of LHD project is presented focusing on the experimental program and the recent achievements in basic parameters and in steady state operations. Since, its start in a year 1998, a remarkable progress has presently resulted in the temperature of 140 Million degree, the highest density of 500 Thousand Billion/cc with the internal density barrier (IDB) and the highest steady average beta of 4.5% in helical plasma devices and the largest total input energy of 1.6 GJ, in all magnetic confinement fusion devices. Finally, a perspective is given of the ITER Broad Approach program

  11. Frontier of Fusion Research: Path to the Steady State Fusion Reactor by Large Helical Device

    SciTech Connect

    Motojima, Osamu

    2006-12-01

    The ITER, the International Thermonuclear Experimental Reactor, which will be built in Cadarache in France, has finally started this year, 2006. Since the thermal energy produced by fusion reactions divided by the external heating power, i.e., the Q value, will be larger than 10, this is a big step of the fusion research for half a century trying to tame the nuclear fusion for the 6.5 Billion people on the Earth. The source of the Sun's power is lasting steadily and safely for 8 Billion years. As a potentially safe environmentally friendly and economically competitive energy source, fusion should provide a sustainable future energy supply for all mankind for ten thousands of years. At the frontier of fusion research important milestones are recently marked on a long road toward a true prototype fusion reactor. In its own merits, research into harnessing turbulent burning plasmas and thereby controlling fusion reaction, is one of the grand challenges of complex systems science.After a brief overview of a status of world fusion projects, a focus is given on fusion research at the National Institute for Fusion Science (NIFS) in Japan, which is playing a role of the Inter University Institute, the coordinating Center of Excellence for academic fusion research and by the Large Helical Device (LHD), the world's largest superconducting heliotron device, as a National Users' facility. The current status of LHD project is presented focusing on the experimental program and the recent achievements in basic parameters and in steady state operations. Since, its start in a year 1998, a remarkable progress has presently resulted in the temperature of 140 Million degree, the highest density of 500 Thousand Billion/cc with the internal density barrier (IDB) and the highest steady average beta of 4.5% in helical plasma devices and the largest total input energy of 1.6 GJ, in all magnetic confinement fusion devices. Finally, a perspective is given of the ITER Broad Approach program

  12. A Spherical Torus Nuclear Fusion Reactor Space Propulsion Vehicle Concept for Fast Interplanetary Piloted and Robotic Missions

    NASA Astrophysics Data System (ADS)

    Williams, C. H.; Borowski, S. K.; Dudzinski, L. A.; Juhasz, A. J.

    1999-11-01

    A conceptual space vehicle concept to support NASA's 21^st century requirements was designed to enable human, multi-month travel throughout the outer solar system. The design was predicated on an ignited, spherical torus fusion reactor (R=2.5 m; a=1.25 m) burning spin polarized D^3He fuel and operating at high beta (30%). Peaked plasma temperature (50 keV) and number density (5×10^20 m-3) profiles were used. Engineering design was performed on all major vehicle systems including fusion reactor, fast wave plasma heating, power conversion, magnetic nozzle (for direct plasma propulsion), tankage and others, with emphasis on 1D fusion power balance, operation physics, first wall, toroidal field coils, and heat transfer. Two related proof-of-concept experiments at OSU, LANL, and PPPL are discussed. Results showed a 108 mt crew habitat payload could be delivered to Saturn rendezvous in 214 days using 6,145 MW of plasma jet power.

  13. 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.

  14. 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. PMID:26667208

  15. 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.

  16. 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.

  17. 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. PMID:27147038

  18. 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

  19. 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. PMID:26827318

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. The status of cold fusion

    NASA Astrophysics Data System (ADS)

    Storms, E.

    This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Superconductivity Engineering and Its Application for Fusion 3.Superconducting Technology as a Gateway to Future Technology

    NASA Astrophysics Data System (ADS)

    Asano, Katsuhiko

    Hopes for achieving a new source of energy through nuclear fusion rest on the development of superconducting technology that is needed to make future equipments more energy efficient as well as increase their performance. Superconducting technology has made progress in a wide variety of fields, such as energy, life science, electronics, industrial use and environmental improvement. It enables the actualization of equipment that was unachievable with conventional technology, and will sustain future “IT-Based Quality Life Style”, “Sustainable Environmental” and “Advanced Healthcare” society. Besides coil technology with high magnetic field performance, superconducting electoronics or device technology, such as SQUID and SFQ-circuit, high temperature superconducting material and advanced cryogenics technology might be great significance in the history of nuclear fusion which requires so many wide, high and ultra technology. Superconducting technology seems to be the catalyst for a changing future society with nuclear fusion. As society changes, so will superconducting technology.

  13. An evaluation of fusion gain in the compact helical fusion reactor FFHR-c1

    NASA Astrophysics Data System (ADS)

    Miyazawa, J.; Goto, T.; Sakamoto, R.; Sagara, A.; the FFHR Design Group

    2014-01-01

    A new procedure to predict achievable fusion gain in a sub-ignition fusion reactor is proposed. This procedure uses the direct profile extrapolation (DPE) method based on the gyro-Bohm model. The DPE method has been developed to predict the radial profiles in a fusion reactor sustained without auxiliary heating (i.e., in the self-ignition state) from the experimental data. To evaluate the fusion gain in a fusion reactor sustained with auxiliary heating (i.e., in the sub-ignition state), the DPE method is modified to include the influence of the auxiliary heating. The beta scale factor from experiment to reactor is assumed to be 1. Under this assumption, it becomes reasonable to apply the magnetohydrodynamic (MHD) equilibrium (which is calculated to reproduce the experimental data) to the reactor. At the same time, the MHD stability of the reactor plasma is also guaranteed to a certain extent since that beta was already proven in the experiment. The fusion gain in the helical type nuclear test machine FFHR-c1 has been evaluated using this modified DPE method. FFHR-c1 is basically a large duplication of the Large Helical Device (LHD) with a scale factor of 10/3, which corresponds to the major radius of the helical coils of 13.0 m and the plasma volume of ∼1000 m3. Two options with different magnetic field strengths are considered. The fusion gain in FFHR-c1 extrapolated from a set of radial profile data obtained in LHD ranges from 1 to 7, depending on the profiles used together with the assumptions of the magnetic field strength and the alpha heating efficiency.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. 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.

  17. 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.

  18. 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. PMID:26932032

  19. Inertial fusion research in China

    NASA Astrophysics Data System (ADS)

    He, X. T.; Zhang, W. Y.

    2007-08-01

    The goal of the first milestone of the inertial fusion program in China is to reach fusion ignition and plasma burning in about 2020. Under the program, in the past years, the inertial fusion physics research achieved great progress; the laser facilities and the support technologies for laser drivers are advanced; the advanced diagnostic techniques are developed and the relatively integrated system is set up; the precise target fabrications are coordinately developed.

  20. A realistic, gradual and economical approach to fusion power

    NASA Astrophysics Data System (ADS)

    Szoeke, A.; Moir, R. W.

    1991-06-01

    This article describes, in broad outline, a nuclear power plant that generates power by means of repetitive, low-yield explosions in an underground chamber. Such a plant can be built in the near future by using modest extensions of existing technology, and it could be economically competitive if certain parts of the cost are controlled. This is in contrast to magnetic and inertial confinement fusion, of which the technical and economic feasibility will remain highly uncertain for the foreseeable future. Technical improvements of the envisioned plant can be introduced gradually with corresponding reductions in cost of power production. With advancing technology, an increasingly larger fraction of the power can be extracted from fusion reactions, thus providing a smooth transition to a fusion-based economy. Eventually, pure (inertial) fusion schemes could be incorporated into the power plant in a natural way, thereby shortening the time required to achieve large-scale use of fusion power, possibly by decades. This article considers both the technical aspects of this route to fusion power and the relevant issues of public policy.

  1. Heterologous signals allow efficient targeting of a nuclear-encoded fusion protein to plastids and endoplasmic reticulum in diverse plant species.

    PubMed

    Gnanasambandam, Annathurai; Polkinghorne, Ian G; Birch, Robert G

    2007-03-01

    Approximately 30% of plant nuclear genes appear to encode proteins targeted to the plastids or endoplasmic reticulum (ER). The signals that direct proteins into these compartments are diverse in sequence, but, on the basis of a limited number of tests in heterologous systems, they appear to be functionally conserved across species. To further test the generality of this conclusion, we tested the ability of two plastid transit peptides and an ER signal peptide to target green fluorescent protein (GFP) in 12 crops, including three monocots (barley, sugarcane, wheat) and nine dicots (Arabidopsis, broccoli, cabbage, carrot, cauliflower, lettuce, radish, tobacco, turnip). In all species, transient assays following microprojectile bombardment or vacuum infiltration using Agrobacterium showed that the plastid transit peptides from tomato DCL (defective chloroplast and leaves) and tobacco RbcS [ribulose bisphosphate carboxylase (Rubisco) small subunit] genes were effective in targeting GFP to the leaf plastids. GFP engineered as a fusion to the N-terminal ER signal peptide from Arabidopsis basic chitinase and a C-terminal HDEL signal for protein retention in the ER was accumulated in the ER of all species. The results in tobacco were confirmed in stably transformed cells. These signal sequences should be useful to direct proteins to the plastid stroma or ER lumen in diverse plant species of biotechnological interest for the accumulation of particular recombinant proteins or for the modification of particular metabolic streams.

  2. 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.

  3. 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).

  4. Fusion Implementation

    SciTech Connect

    J.A. Schmidt

    2002-02-20

    If a fusion DEMO reactor can be brought into operation during the first half of this century, fusion power production can have a significant impact on carbon dioxide production during the latter half of the century. An assessment of fusion implementation scenarios shows that the resource demands and waste production associated with these scenarios are manageable factors. If fusion is implemented during the latter half of this century it will be one element of a portfolio of (hopefully) carbon dioxide limiting sources of electrical power. It is time to assess the regional implications of fusion power implementation. An important attribute of fusion power is the wide range of possible regions of the country, or countries in the world, where power plants can be located. Unlike most renewable energy options, fusion energy will function within a local distribution system and not require costly, and difficult, long distance transmission systems. For example, the East Coast of the United States is a prime candidate for fusion power deployment by virtue of its distance from renewable energy sources. As fossil fuels become less and less available as an energy option, the transmission of energy across bodies of water will become very expensive. On a global scale, fusion power will be particularly attractive for regions separated from sources of renewable energy by oceans.

  5. 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

  6. 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....

  7. 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.

  8. SABR Fusion-Fission Hybrid Studies

    NASA Astrophysics Data System (ADS)

    Stewart, Chris

    2012-03-01

    The Subcritical Advanced Burner Reactor (SABR) concept is a fast reactor comprised of a tokamak fusion neutron source based on ITER surrounded by an annular fission core adapted from Integral Fast Reactor designs. Previous work has examined SABR used to help close the nuclear fuel cycle by fissioning the transuranics from spent nuclear fuel. One focus of the present work is a SABR Breeder Reactor to achieve tritium self-sufficieny and a Pu breeding ratio significantly above 1 in order to provide fuel for SABR as well as for MOX-fueled LWR's and other fast reactors. Another focus of this research is the dynamic safety simulation of lloss-of-flow loss-of-heat-sink, loss-of-power, and positive reactivity accidents in the TRU fuel SABR burner reactor. The reactivity effect of thermal-induced bowing of fuel pins has been modeled, which is expected to provide passive safety.

  9. 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

  10. 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.

  11. 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.

  12. A fusion-driven subcritical system concept based on viable technologies

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Jiang, J.; Wang, M.; Jin, M.; FDS Team

    2011-10-01

    A fusion-driven hybrid subcritical system (FDS) concept has been designed and proposed as spent fuel burner based on viable technologies. The plasma fusion driver can be designed based on relatively easily achieved plasma parameters extrapolated from the successful operation of existing fusion experimental devices such as the EAST tokamak in China and other tokamaks in the world, and the subcritical fission blanket can be designed based on the well-developed technologies of fission power plants. The simulation calculations and performance analyses of plasma physics, neutronics, thermal-hydraulics, thermomechanics and safety have shown that the proposed concept can meet the requirements of tritium self-sufficiency and sufficient energy gain as well as effective burning of nuclear waste from fission power plants and efficient breeding of nuclear fuel to feed fission power plants.

  13. 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.

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

    SciTech Connect

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

    2010-10-15

    The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded {gamma}-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 {gamma}-rays, with a branching ratio of the order of 10{sup -5}{gamma}/(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 {gamma}-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available {gamma}-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 {gamma}-rays produced by inelastic scatter of DT fusion neutrons on {sup 12}C nuclei in the ablating plastic capsule material.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. Lateral Lumbar Interbody Fusion.

    PubMed

    Pawar, Abhijit; Hughes, Alexander; Girardi, Federico; Sama, Andrew; Lebl, Darren; Cammisa, Frank

    2015-12-01

    The lateral lumbar interbody fusion (LLIF) is a relatively new technique that allows the surgeon to access the intervertebral space from a direct lateral approach either anterior to or through the psoas muscle. This approach provides an alternative to anterior lumbar interbody fusion with instrumentation, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion for anterior column support. LLIF is minimally invasive, safe, better structural support from the apophyseal ring, potential for coronal plane deformity correction, and indirect decompression, which have has made this technique popular. LLIF is currently being utilized for a variety of pathologies including but not limited to adult de novo lumbar scoliosis, central and foraminal stenosis, spondylolisthesis, and adjacent segment degeneration. Although early clinical outcomes have been good, the potential for significant neurological and vascular vertebral endplate complications exists. Nevertheless, LLIF is a promising technique with the potential to more effectively treat complex adult de novo scoliosis and achieve predictable fusion while avoiding the complications of traditional anterior surgery and posterior interbody techniques. PMID:26713134

  1. Lateral Lumbar Interbody Fusion

    PubMed Central

    Hughes, Alexander; Girardi, Federico; Sama, Andrew; Lebl, Darren; Cammisa, Frank

    2015-01-01

    The lateral lumbar interbody fusion (LLIF) is a relatively new technique that allows the surgeon to access the intervertebral space from a direct lateral approach either anterior to or through the psoas muscle. This approach provides an alternative to anterior lumbar interbody fusion with instrumentation, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion for anterior column support. LLIF is minimally invasive, safe, better structural support from the apophyseal ring, potential for coronal plane deformity correction, and indirect decompression, which have has made this technique popular. LLIF is currently being utilized for a variety of pathologies including but not limited to adult de novo lumbar scoliosis, central and foraminal stenosis, spondylolisthesis, and adjacent segment degeneration. Although early clinical outcomes have been good, the potential for significant neurological and vascular vertebral endplate complications exists. Nevertheless, LLIF is a promising technique with the potential to more effectively treat complex adult de novo scoliosis and achieve predictable fusion while avoiding the complications of traditional anterior surgery and posterior interbody techniques. PMID:26713134

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Application of polarized nuclei to fusion

    SciTech Connect

    Kulsrud, R.M.

    1987-07-01

    It is shown that the d-t fusion reaction can be modified by polarizing nuclear spins. The ways in which this improves reactor performance are mentioned and the feasibility of the process of spin polarization for magnetic fusion is discussed. 18 refs.

  9. 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.

  10. 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)

  11. 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

  12. Nuclear behavior in triple-conjugant fusion complexes of the ciliate Stylonychia pustulata: Inhibition of meiosis and retention of the macronucleus.

    PubMed

    Yano, J; Suhama, M

    1990-06-29

    The relationship between temporary conjugation and the conjugant fusion of the hypotrich ciliate Stylonychia pustulata was examined by use of singlet cells of stocks HH1 and TK1, and back-to-back doublet cells of stock NM2 with two attachment sites. The TK1 cells caused conjugant fusion in cell pairing. Triple-conjugant fusion (TCF) complexes composed of an HH1 cell, an NM2 doublet and a TK1 cell were obtained by mixing cells from three stocks. Multiple-conjugant fusion complexes composed of a TK1 cell and three or four NM2 doublets were also found. Initiation of meiosis in TCF complexes was not disturbed by the union of a TK1 cell and a component of the doublet member, but meiosis was blocked at the parachute stage. Thereafter, many micronuclei underwent mitosis. These results suggest that a meiosis blocking factor is present in the cytoplasm of the TK1 cell and migrates to both the doublet and the HH1 members. The macronuclei in doublet and HH1 members changed from elongated and fragmented shapes to spheres. The HH1 and doublet members shifted from conjugation to conjugant fusion. The doublet and HH1 members split from TCF complexes within an hour of the onset of pairing underwent either autogamy or cell division. PMID:23196046

  13. (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.

  14. 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.

  15. Fission-fusion neutron source

    NASA Astrophysics Data System (ADS)

    Yu, Jinnan; Yu, Gang

    2009-04-01

    In order to meet the requirements of fusion power reactors and nuclear waste treatment, a concept of fission-fusion neutron source is proposed, which consists of a LiD assembly located in the heavy water region of the China Advanced Research Reactor. This assembly of LiD fuel rods will be irradiated with slow neutrons and will produce fusion neutrons in the central hole via the reaction 6Li(n, α). More precisely, tritium ions with a high energy of 2.739 MeV will be produced in LiD by the impinging slow neutrons. The tritium ions will in turn bombard the deuterium ions present in the LiD assembly, which will induce fusion reaction and then the production of 14 MeV neutrons. The fusion reaction rate will increase with the accumulation of tritium in LiD by the reaction between tritium and deuteron recoils produced by the 14 MeV neutrons. When the concentration of tritium reaches 0.5 · 10 22 and the fraction of fusion reactions between tritium and deuteron recoils approaches 1, the 14 MeV neutron flux is doubled and redoubled, an so forth, approaching saturation in which the tritium produced at a time t is exhausted by the fusion reactions to keep constant the tritium concentration in LiD.

  16. 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

  17. 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

  18. Cold Fusion Has Now Come Out of the Cold

    NASA Astrophysics Data System (ADS)

    Storms, Edmund

    2003-10-01

    The phenomenon called cold fusion or LENR (Low-Energy-Nuclear-Reaction) has now achieved a level of reproducibility and understanding that warrants re-examination of the claims. A summary of what is known and want is being done worldwide to obtain more knowledge will be given. Rather than disappearing as better data are obtained, the effects are becoming more reproducible and of greater magnitude. Justification for this claim can be obtained at www.LENR-CANR.org. The phenomenon is too important to ignore any longer even though it conflicts with conventional theory.

  19. Fusion blanket inherent safety assessment

    SciTech Connect

    Sze, D.K.; Jung, J.; Cheng, E.T.

    1986-01-01

    The inherent safety aspect of TPSS reactor blankets has been investigated. The idea is to design the blanket so safe that cost savings can be realized such as through non-nuclear grading construction. If the blanket materials are carefully selected, inherent safety is feasible for fusion reactor blankets up to 5 to 10 MW/m/sup 2/ neutron wall loading.

  20. Medical image fusion by wavelet transform modulus maxima

    NASA Astrophysics Data System (ADS)

    Guihong, Qu; Dali, Zhang; Pingfan, Yan

    2001-08-01

    Medical image fusion has been used to derive useful information from multimodality medical image data. In this research, we propose a novel method for multimodality medical image fusion. Using wavelet transform, we achieved a fusion scheme. Afusion rule is proposed and used for calculating the wavelet transformation modulus maxima of input images at different bandwidths and levels. To evaluate the fusion result, a metric based on mutual information (MI) is presented for measuring fusion effect. The performances of other two methods of image fusion based on wavelet transform are briefly described for comparison. The experiment results demonstrate the effectiveness of the fusion scheme.

  1. Nuclear Fusion In Gases Of Deuterium Clusters And Hot Electron Generation In Droplet Sprays Under Irradiation With An Intense Femtosecond Laser

    SciTech Connect

    T. Ditmire; Zweiback, J; Cowan, T E; Hays, G; Wharton, K B; Crane, J K; Wilks, S C; Smith, R A; Donnelly, T D; Rust, M; Weiner, I; Allen, M

    2001-07-18

    In conclusion, we have observed the production of 2.45 MeV deuterium fusion neutrons when a gas of deuterium clusters is irradiated with a 120 mJ, 35 fs laser pulse. When the focal position is optimized, we have observed as many as 10{sup 4} neutrons per laser shot. This yield is consistent with some simple estimates for the fusion yield. We also find that the fusion yield is a sensitive function of the deuterium cluster size in the target jet, a consequence of the Coulomb explosion origin of the fast deuterons. We also find that the neutron pulse duration is fast, with a characteristic burn time of well under 1 ns. This experiment may represent a means for producing a compact, table-top source of short pulse fusion neutrons for applications. Furthermore, we have measured hard x-ray yield from femtosecond laser interactions with both solid and micron scale droplet targets. Strong hard x-ray production is observed from both targets. However, the inferred electron temperature is somewhat higher in the case of irradiation of the droplets. These data are consistent with PIC simulations. This finding indicates that quite unique hot electron dynamics occur during the irradiation of wavelength scale particles by an intense laser field and likely warrants further study.

  2. 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.

  3. Neutron scattering effects on fusion ion temperature measurements.

    SciTech Connect

    Ziegler, Lee; Starner, Jason R.; Cooper, Gary Wayne; Ruiz, Carlos L.; Franklin, James Kenneth; Casey, Daniel T.

    2006-06-01

    To support the nuclear fusion program at Sandia National Laboratories (SNL), a consistent and verifiable method to determine fusion ion temperatures needs to be developed. Since the fusion temperature directly affects the width in the spread of neutron energies produced, a measurement of the neutron energy width can yield the fusion temperature. Traditionally, the spread in neutron energies is measured by using time-of-flight to convert a spread in neutron energies at the source to a spread in time at detector. One potential obstacle to using this technique at the Z facility at SNL is the need to shield the neutron detectors from the intense bremsstrahlung produced. The shielding consists of eight inches of lead and the concern is that neutrons will scatter in the lead, artificially broaden the neutron pulse width and lead to an erroneous measurement. To address this issue, experiments were performed at the University of Rochester's Laboratory for Laser Energetics, which demonstrated that a reliable ion temperature measurement can be achieved behind eight inches of lead shielding. To further expand upon this finding, Monte Carlo N-Particle eXtended (MCNPX) was used to simulate the experimental geometric conditions and perform the neutron transport. MCNPX was able to confidently estimate results observed at the University of Rochester.

  4. 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.

  5. 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.

  6. Prospects for fusion applications of reversed-field pinches

    NASA Astrophysics Data System (ADS)

    Bathke, C. G.; Krakowski, R. A.; Hagenson, R. L.

    1985-11-01

    The applicability of the Reversed-Field Pinch (RFP) as a source of fusion neutrons for use in developing key fusion nuclear technologies is examined. This Fusion Test Facility (FTF) would emphasize high neutron wall loading, small plasma volume, low fusion and driver powers, and steady-state operation. Both parametric tradeoffs based on present-day physics understanding and a conceptual design based on an approx. 1-MW/m (neutron) driven operation are reported.

  7. 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.

  8. 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.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

    Yamanaka, C.

    2008-05-01

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

  11. Ch. 37, Inertial Fusion Energy Technology

    SciTech Connect

    Moses, E

    2010-06-09

    Nuclear fission, nuclear fusion, and renewable energy (including biofuels) are the only energy sources capable of satisfying the Earth's need for power for the next century and beyond without the negative environmental impacts of fossil fuels. Substantially increasing the use of nuclear fission and renewable energy now could help reduce dependency on fossil fuels, but nuclear fusion has the potential of becoming the ultimate base-load energy source. Fusion is an attractive fuel source because it is virtually inexhaustible, widely available, and lacks proliferation concerns. It also has a greatly reduced waste impact, and no danger of runaway reactions or meltdowns. The substantial environmental, commercial, and security benefits of fusion continue to motivate the research needed to make fusion power a reality. Replicating the fusion reactions that power the sun and stars to meet Earth's energy needs has been a long-sought scientific and engineering challenge. In fact, this technological challenge is arguably the most difficult ever undertaken. Even after roughly 60 years of worldwide research, much more remains to be learned. the magnitude of the task has caused some to declare that fusion is 20 years away, and always will be. This glib criticism ignores the enormous progress that has occurred during those decades, progress inboth scientific understanding and essential technologies that has enabled experiments producing significant amounts of fusion energy. For example, more than 15 megawatts of fusion power was produced in a pulse of about half a second. Practical fusion power plants will need to produce higher powers averaged over much longer periods of time. In addition, the most efficient experiments to date have required using about 50% more energy than the resulting fusion reaction generated. That is, there was no net energy gain, which is essential if fusion energy is to be a viable source of electricity. The simplest fusion fuels, the heavy isotopes of

  12. Reviewers Comments on the 5th Symposium and the Status of Fusion Research 2003

    SciTech Connect

    Post, R F

    2005-02-03

    Better to understand the status of fusion research in the year 2003 we will first put the research in its historical context. Fusion power research, now beginning its sixth decade of continuous effort, is unique in the field of scientific research. Unique in its mixture of pure and applied research, unique in its long-term goal and its promise for the future, and unique in the degree that it has been guided and constrained by national and international governmental policy. Though fusion research's goal has from the start been precisely defined, namely, to obtain a net release of energy from controlled nuclear fusion reactions between light isotopes (in particular those of hydrogen and helium) the difficulty of the problem has spawned in the past a very wide variety of approaches to the problem. Some of these approaches have had massive international support for decades, some have been pursued only at a ''shoestring'' level by dedicated groups in small research laboratories or universities. In discussing the historical and present status of fusion research the implications of there being two distinctly different approaches to achieving net fusion power should be pointed out. The first, and oldest, approach is the use of strong magnetic fields to confine the heated fuel, in the form of a plasma and at a density typically four or five orders of magnitude smaller than the density of the atmosphere. In steady state this fusion fuel density is still sufficient to release fusion energy at the rate of many megawatts per cubic meter. The plasma confinement times required for net energy release in this regime are long--typically a second or more, representing an extremely difficult scientific challenge --witness the five decades of research in magnetic fusion, still without having reaching that goal. The second, more recently initiated approach, is of course the ''inertial'' approach. As its name implies, the ''confinement'' problem is solved ''inertially,'' that is by

  13. The elementary fusion modalities of osteoclasts.

    PubMed

    Søe, Kent; Hobolt-Pedersen, Anne-Sofie; Delaisse, Jean-Marie

    2015-04-01

    The last step of the osteoclast differentiation process is cell fusion. Most efforts to understand the fusion mechanism have focused on the identification of molecules involved in the fusion process. Surprisingly, the basic fusion modalities, which are well known for fusion of other cell types, are not known for the osteoclast. Here we show that osteoclast fusion partners are characterized by differences in mobility, nuclearity, and differentiation level. Our demonstration was based on time-laps videos of human osteoclast preparations from three donors where 656 fusion events were analyzed. Fusions between a mobile and an immobile partner were most frequent (62%), while fusion between two mobile (26%) or two immobile partners (12%) was less frequent (p<0.001). In general, the immobile fusion partner contained more nuclei than the mobile one (p<0.01). Furthermore, enrichment in nuclei of an osteoclast with three or more nuclei resulted from fusion with a mono-nucleated cell in 67% of the cases (p<0.001), while mono-nucleated cells fused with a multinucleated cell in 61% of the cases (p<0.05). This observation suggested that a more mature osteoclast prefers to fuse with a less mature pre-osteoclast. This hypothesis was supported by a nucleus-tracing approach in a co-culture of more and less differentiated pre-osteoclasts/osteoclasts. Furthermore, we found that osteoclast fusion proceeds through primarily two different types of cell contacts: phagocytic-cup and broad-contact-surfaces (>80% of all fusions). We conclude that osteoclasts most often gain nuclei by addition of one nucleus at a time, and that this nucleus is most often delivered by a moving cell to an immobile cell. These characteristics fit the in vivo observations where mono-nucleated precursors migrating from the bone marrow fuse with more mature osteoclasts sitting on the bone surface. They also fit the fusion modalities of other cell types.

  14. Electromagnetic computations for fusion devices

    SciTech Connect

    Turner, L.R.

    1989-09-01

    Among the difficulties in making nuclear fusion a useful energy source, two important ones are producing the magnetic fields needed to drive and confine the plasma, and controlling the eddy currents induced in electrically conducting components by changing fields. All over the world, researchers are developing electromagnetic codes and employing them to compute electromagnetic effects. Ferromagnetic components of a fusion reactor introduce field distortions. Eddy currents are induced in the vacuum vessel, blanket and other torus components of a tokamak when the plasma current disrupts. These eddy currents lead to large forces, and 3-D codes are being developed to study the currents and forces. 35 refs., 6 figs.

  15. 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.

  16. 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

    SciTech Connect

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

    2015-08-15

    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.

  17. 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.

  18. 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. PMID:26329181

  19. Tandem mirror fusion-fission hybrid studies

    NASA Astrophysics Data System (ADS)

    Lee, J. D.

    1980-04-01

    The concept of combining nuclear fusion and nuclear fission techniques is discussed. Initial tandem mirror hybrid studies predict the ability to produce large amounts of fissile fuel (2 to 7 tons U233 per year from a 4000 MW plant) at a cost that adds less than 25% to the cost of power from a light water reactor.

  20. 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…

  1. 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.

  2. 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)

  3. Protoplast Fusion

    PubMed Central

    Yamada, Yasuyuki; Hara, Yasuhiro; Katagi, Hiroaki; Senda, Mitsugi

    1980-01-01

    The relation between the composition of the phospholipid molecular species in a cell membrane and the velocity of protoplast fusion was studied using cells cultured at a low temperature (10 C). Cells cultured at a low temperature contained larger proportions of phospholipids of low phase transition point, the 1,2-dilinoleoyl-type, than those cultured at a normal temperature (25 C). When treated with polyethylene glycol 6000, protoplasts from cells cultured at 10 C fused and progressed to the fused sphere stage more rapidly than did those from cells cultured at 25 C. PMID:16661339

  4. Splenogonadal fusion.

    PubMed

    Tsingoglou, S; Wilkinson, A W

    1976-04-01

    The fusion between splenic tissue and the left gonad or the derivatives of the left mesonephros is a rare congenital anomaly first described in detail by Pommer in 1887/9 and divided into two forms by Putschar and Manion in 1956. In the first or continuous type a cord of splenic or fibrous tissue connects the spleen and the gonadalmesonephric structures. In the second type the fused splenomesonephric structures have lost continuity with the main spleen. An example of the continuous form is presented and the previous reports are briefly reviewed.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 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. PMID:20873683

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Fusion Blanket Development in FDF

    NASA Astrophysics Data System (ADS)

    Wong, C. P. C.; Smith, J. P.; Stambaugh, R. D.

    2008-11-01

    To satisfy the electricity and tritium self-sufficiency missions of a Fusion Development Facility (FDF), suitable blanket designs will need to be evaluated, selected and developed. To demonstrate closure of the fusion fuel cycle, 2-3 main tritium breeding blankets will be used to cover most of the available chamber surface area in order to reach the project goal of achieving a tritium breeding ratio, TBR > 1. To demonstrate the feasibility of electricity and tritium production for subsequent devices such as the fusion demonstration power reactor (DEMO), several advanced test blankets will need to be selected and tested on the FDF to demonstrate high coolant outlet temperature necessary for efficient electricity production. Since the design goals for the main and test blankets are different, the design criteria of these blankets will also be different. The considerations in performing the evaluation of blanket and structural material options in concert with the maintenance approach for the FDF will be reported in this paper.

  15. 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.

  16. 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.

  17. Mitochondrial Fusion Is Essential for Steroid Biosynthesis

    PubMed Central

    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. PMID:23029265

  18. 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.

  19. Contribution of neutron reactions in hybrid targets of inertial heavy ion fusion (HIF)

    NASA Astrophysics Data System (ADS)

    Imshennik, V. S.; Zhukov, V. T.

    2006-08-01

    Recently some simple estimations (Koskarev, Sharkov) were made for capability of achievement of critical conditions in an uranium shell of HIF energetic target, and afterwards it was proved use of an uranium shell (pusher) for substantial expansion of energy-release in a such hybrid target. The mentioned justification is included accounting of neutron-induced fission in the pusher. This accounting is formulated as generalization for cylindrical geometry of the well-known Axiezer-Pomeranchuk solution. A corresponding analytical solution of one-speed Payerls equation allows sufficiently accurately to compute the critical parameters of the uranium pusher in hydrodynamic model of compression and fusion of HIF target ( taking into account of development of chain nuclear fission reaction under critical condition achievement). Nevertheless the implemented computations show that the most essential effect is forced nuclear fission of uranium under the influence of thermonuclear neutrons generated by fusion of deuterium- tritium fuel in the central region of the target. In these computations we use a simple analytical description of forced nuclear fission of uranium by thermonuclear neutrons. The critical conditions are not achieved in the considered ( not optimized) hybrid targets but they are close to accomplishment in the investigated shock-free compression regime. This regime of compression is the most adequate one for hybrid HIF targets. The obtained results allow us to make conclusion of advisability of further development of energetic hybrid HIF targets particularly their optimization and utilization of natural uranium as pusher materials.

  20. 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

  1. Heavy-ion versus {sup 3}He/{sup 4}He fusion-fission reactions: Angular momentum dependence of dissipation in nuclear fission

    SciTech Connect

    Ye, W.

    2011-09-15

    The stochastic Langevin model is employed to study dissipation properties in fission in the {sup 16}O + {sup 181}Ta {yields}{sup 197}Tl system by analyzing prescission neutron yields measured in this reaction. It has been found that the {sup 197}Tl nuclei undergo fission that is not in accordance with the standard Bohr-Wheeler statistical theory. A detailed comparison with previously published work in which fission excitation functions measured in {sup 3,4}He + {sup 197}Au {yields}{sup 200,201}Tl are shown to be in excellent agreement with the fission width formula predicted by the traditional models of nuclear fission suggests that nuclear dissipation strength may have an angular momentum dependence in addition to the known deformation and temperature dependence. Implications for the basic understanding of the observed abnormal rise in prescission particles at high energy and the need for further experimental confirmations are discussed.

  2. Somatic cell nuclear transfer in buffalos: effect of the fusion and activation protocols and embryo culture system on preimplantation embryo development.

    PubMed

    Simon, Liz; Veerapandian, C; Balasubramanian, S; Subramanian, A

    2006-01-01

    The present study was conducted primarily to evaluate several factors that affect the nuclear transfer programme in water buffalos, in which relatively few studies have been performed. Embryos reconstructed with quiescent fetal fibroblasts and metaphase II cytoplasts were matured for 24 h, and activation was found to be comparatively better than in those matured for 30 h. A significantly higher proportion of embryos fused (52.0 +/- 1.9) and cleaved (51.2 +/- 1.7) when the couplets were fused 4-6 h before activation than when fused and activated simultaneously (46.5 +/- 1.6 and 44.5 +/- 2.0, respectively). Development of nuclear transfer embryos to the blastocyst stage (4.8 +/- 2.2) was supported by a commercially available sequential medium, and cleavage (76.5 +/- 2.8) was significantly higher in this medium compared with cleavage in TCM-199 with oviduct epithelial cell coculture (45.6 +/- 1.5) and synthetic oviduct fluid (21.8 +/- 6.6). Of the 16 cloned embryos transferred, none resulted in pregnancy. The present study demonstrates that optimal numbers of cloned buffalo blastocysts can be obtained from oocytes matured for 24 h, fused 3-4 h before activation and cultured in a commercially available sequential media (G1/G2), thus providing further information to enable successful nuclear transfer in buffalos.

  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. 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.

  5. 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.

  6. NESST: A nuclear energy safety and security treaty-Separating nuclear energy from nuclear weapons

    NASA Astrophysics Data System (ADS)

    McNamara, Brendan

    2012-06-01

    Fission and Fusion energy is matched by the need to completely separate civilian energy programmes from the production of nuclear weapons. The Nuclear Proliferation Treaty (NPT, 1968) muddles these issues together. The case is presented here for making a new Nuclear Energy Security Treaty (NESST) which is rigorous, enforceable without violence, and separate from the political quagmire of nuclear weapons.

  7. Image processing with cellular nonlinear networks implemented on field-programmable gate arrays for real-time applications in nuclear fusion

    NASA Astrophysics Data System (ADS)

    Palazzo, S.; Murari, A.; Vagliasindi, G.; Arena, P.; Mazon, D.; de Maack, A.; Jet-Efda Contributors

    2010-08-01

    In the past years cameras have become increasingly common tools in scientific applications. They are now quite systematically used in magnetic confinement fusion, to the point that infrared imaging is starting to be used systematically for real-time machine protection in major devices. However, in order to guarantee that the control system can always react rapidly in case of critical situations, the time required for the processing of the images must be as predictable as possible. The approach described in this paper combines the new computational paradigm of cellular nonlinear networks (CNNs) with field-programmable gate arrays and has been tested in an application for the detection of hot spots on the plasma facing components in JET. The developed system is able to perform real-time hot spot recognition, by processing the image stream captured by JET wide angle infrared camera, with the guarantee that computational time is constant and deterministic. The statistical results obtained from a quite extensive set of examples show that this solution approximates very well an ad hoc serial software algorithm, with no false or missed alarms and an almost perfect overlapping of alarm intervals. The computational time can be reduced to a millisecond time scale for 8 bit 496×560-sized images. Moreover, in our implementation, the computational time, besides being deterministic, is practically independent of the number of iterations performed by the CNN—unlike software CNN implementations.

  8. The DD Cold Fusion-Transmutation Connection

    NASA Astrophysics Data System (ADS)

    Chubb, Talbot A.

    2005-12-01

    LENR theory must explain dd fusion, alpha-addition transmutations, radiationless nuclear reactions, and three-body nuclear particle reactions. Reaction without radiation requires many-body D Bloch+ periodicity in both location and internal structure dependencies. Electron scattering leads to mixed quantum states. The radiationless dd fusion reaction is 2-D Bloch+ -> {}4 He Bloch2+. Overlap between {}4 He Bloch2+ and surface Cs leads to alpha absorption. In the Iwamura et al. studies active deuterium is created by scattering at diffusion barriers.

  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. Role of Fusion Energy in a Sustainable Global Energy Strategy

    SciTech Connect

    Sheffield, J.

    2001-03-07

    Fusion can play an important role in sustainable global energy because it has an available and unlimited fuel supply and location not restricted by climate or geography. Further, it emits no greenhouse gases. It has no potential for large energy releases in an accident, and no need for more than about 100 years retention for radioactive waste disposal. Substantial progress in the realization of fusion energy has been made during the past 20 years of research. It is now possible to produce significant amounts of energy from controlled deuterium and tritium (DT) reactions in the laboratory. This has led to a growing confidence in our ability to produce burning plasmas with significant energy gain in the next generation of fusion experiments. As success in fusion facilities has underpinned the scientific feasibility of fusion, the high cost of next-step fusion facilities has led to a shift in the focus of international fusion research towards a lower cost development path and an attractive end product. The increasing data base from fusion research allows conceptual fusion power plant studies, of both magnetic and inertial confinement approaches to fusion, to translate commercial requirements into the design features that must be met if fusion is to play a role in the world's energy mix; and identify key R and D items; and benchmark progress in fusion energy development. This paper addresses the question, ''Is mankind closer or farther away from controlled fusion than a few decades ago?'' We review the tremendous scientific progress during the last 10 years. We use 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 of an attractive fusion system with present achievements and to identify remaining technical challenges for fusion. We discuss scenarios for fusion energy deployment in the

  11. Control of a laser inertial confinement fusion-fission power plant

    SciTech Connect

    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.

  12. Mirror Fusion Test Facility magnet system

    SciTech Connect

    VanSant, J.H.; Kozman, T.A.; Bulmer, R.H.; Ng, D.S.

    1981-09-11

    In 1979, R.H. Bulmer of Lawrence Livermore National Laboratory (LLNL) discussed a proposed tandem-mirror magnet system for the Mirror Fusion Test Facility (MFTF) at the 8th symposium on Engineering Problems in Fusion Research. Since then, Congress has voted funds for expanding LLNL's MFTF to a tandem-mirror facility (designated MFTF-B). The new facility, scheduled for completion by 1985, will seek to achieve two goals: (1) Energy break-even capability (Q or the ratio of fusion energy to plasma heating energy = 1) of mirror fusion, (2) Engineering feasibility of reactor-scale machines. Briefly stated, 22 superconducting magnets contained in a 11-m-diam by 65-m-long vacuum vessel will confine a fusion plasma fueled by 80 axial streaming-plasma guns and over 40 radial neutral beams. We have already completed a preliminary design of this magnet system.

  13. 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.

  14. Sub-barrier fusion in generalized boson models

    SciTech Connect

    Balantekin, A.B.; Bennett, J.R.; Kuyucak, S.

    1994-03-01

    The interacting boson model with {ital s} and {ital d} bosons has been used to describe the nuclear structure effects in sub-barrier fusion. We generalize the previous formalism to include arbitrary kinds of bosons in the target nucleus and investigate whether {ital g} bosons have any discernible effect on fusion reactions. In particular, we compare the fusion cross sections, barrier distributions, and the average angular momentum of the compound nucleus in the {ital sd} and {ital sdg} boson models.

  15. 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.

  16. Rho GTPase activity modulates paramyxovirus fusion protein-mediated cell-cell fusion

    SciTech Connect

    Schowalter, Rachel M.; Wurth, Mark A.; Aguilar, Hector C.; Lee, Benhur; Moncman, Carole L.; McCann, Richard O.; Dutch, Rebecca Ellis . E-mail: rdutc2@uky.edu

    2006-07-05

    The paramyxovirus fusion protein (F) promotes fusion of the viral envelope with the plasma membrane of target cells as well as cell-cell fusion. The plasma membrane is closely associated with the actin cytoskeleton, but the role of actin dynamics in paramyxovirus F-mediated membrane fusion is unclear. We examined cell-cell fusion promoted by two different paramyxovirus F proteins in three cell types in the presence of constitutively active Rho family GTPases, major cellular coordinators of actin dynamics. Reporter gene and syncytia assays demonstrated that expression of either Rac1{sup V12} or Cdc42{sup V12} could increase cell-cell fusion promoted by the Hendra or SV5 glycoproteins, though the effect was dependent on the cell type expressing the viral glycoproteins. In contrast, RhoA{sup L63} decreased cell-cell fusion promoted by Hendra glycoproteins but had little affect on SV5 F-mediated fusion. Also, data suggested that GTPase activation in the viral glycoprotein-containing cell was primarily responsible for changes in fusion. Additionally, we found that activated Cdc42 promoted nuclear rearrangement in syncytia.

  17. Magnetless magnetic fusion

    NASA Astrophysics Data System (ADS)

    Beklemishev, A. D.; Tajima, T.

    1994-02-01

    The authors propose a concept of thermonuclear fusion reactor in which the plasma pressure is balanced by direct gas-wall interaction in a high-pressure vessel. The energy confinement is achieved by means of the self-contained toroidal magnetic configuration sustained by an external current drive or charged fusion products. This field structure causes the plasma pressure to decrease toward the inside of the discharge and thus it should be magnetohydrodynamically stable. The maximum size, temperature and density profiles of the reactor are estimated. An important feature of confinement physics is the thin layer of cold gas at the wall and the adjacent transitional region of dense arc-like plasma. The burning condition is determined by the balance between these nonmagnetized layers and the current-carrying plasma. They suggest several questions for future investigation, such as the thermal stability of the transition layer and the possibility of an effective heating and current drive behind the dense edge plasma. The main advantage of this scheme is the absence of strong external magnets and, consequently, potentially cheaper design and lower energy consumption.

  18. A hidden Markov model for multimodal biometrics score fusion

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng

    2011-05-01

    There are strong evidences of that multimodal biometric score fusion can significantly improve human identification performance. Score level fusion usually involves score normalization, score fusion, and fusion decision. There are several types of score fusion methods, direct combination of fusion scores, classifier-based fusion, and density-based fusion. The real applications require achieving greater reliability in determining or verifying person's identity. The goal of this research is to improve the accuracy and robustness of human identification by using multimodal biometrics score fusion. The accuracy means high verification rate if tested on a closed dataset, or a high genuine accept rate under low false accept rate if tested on an open dataset. While the robustness means the fusion performance is stable with variant biometric scores. We propose a hidden Markov model (HMM) for multiple score fusion, where the biometric scores include multimodal scores and multi-matcher scores. The state probability density functions in a HHM model are estimated by Gaussian mixture model. The proposed HMM model for multiple score fusion is accurate for identification, flexible and reliable with biometrics. The proposed HMM method are tested on three NIST-BSSR1 multimodal databases and on three face-score databases. The results show the HMM method is an excellent and reliable score fusion method.

  19. Magnetic fusion: progress -> stagnation -> degradation

    NASA Astrophysics Data System (ADS)

    Zakharov, Leonid

    2012-10-01

    ``The theory of the failure of magnetic fusion,'' created in 2004 and presented to APS-2007 introduced the notion of the ``difficult'' and ``complicated'' stages of the program and described them details. At the first phase the emerging fusion science was created under strong leadership. Progress was visible on year to year basis, and the program was easy to manage. The complicated phase started in the late 1980s, when the plasma physics appeared to be incapable to implement the mission of ITER to test nuclear components of a fusion reactor. Then, the failure of TFTR (PPPL, USA) and JET (Culham, UK) in the mid 1990 to demonstrate QDT=1 and the blindness of their leaders to already visible means to resolve the problem, were a clear indication of an irreversible stagnation. In fact, right after 2007, it became clear that in the case of a large system of human ``particles'' (scientists) two phases have a continuation. The internal degrees of freedom, otherwise protected from external perturbations by a strong dedication to the scientific method, are now eroding and collapsing. The loss of science in addressing confinement, stability, power extraction, fueling, stationary regimes issues makes the current program irrelevant to fusion energy. A fresh approach should be taken.

  20. 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.

  1. [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. PMID:27192844

  2. Influence of the colloidal structure of dairy gels on milk fat fusion behavior: quantification of the liquid fat content by in situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR).

    PubMed

    Bouteille, Romain; Perez, Jeanne; Khifer, Farid; Jouan-Rimbaud-Bouveresse, Delphine; Lecanu, Bruno; This, Hervé

    2013-04-01

    Dairy gels (DG), such as yoghurts, contain both solid and liquid fats at the time of consumption, as their temperature rises to anything between 10 and 24 °C after being introduced into the mouth at 4 °C. The mass ratio between solid and liquid fats, which depends on the temperature, impacts the organoleptic properties of DG. As the ordinary methods for determining this ratio can only be applied to samples consisting mainly in fat materials, a fat extraction step needs to be added into the analytical process when applied to DG, which prevents the study of the potential impact of their colloidal structure on milk fat fusion behavior. In situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR) was investigated as a method for direct measurements in DG: at temperatures between 20.0 and 70.0 °C, the liquid fat content and the composition of triacylglycerols of the liquid phase (in terms of alkyl chains length) were determined. Spectra of isolated milk fat also enable the quantification of the double bonds of triacylglycerols. Statistical tests showed no significant difference between isolated milk fat and milk fat inside a DG in terms of melting behavior: the fat globule membrane does not seem to have a significant influence on the fat melting behavior.

  3. [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.

  4. Influence of the colloidal structure of dairy gels on milk fat fusion behavior: quantification of the liquid fat content by in situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR).

    PubMed

    Bouteille, Romain; Perez, Jeanne; Khifer, Farid; Jouan-Rimbaud-Bouveresse, Delphine; Lecanu, Bruno; This, Hervé

    2013-04-01

    Dairy gels (DG), such as yoghurts, contain both solid and liquid fats at the time of consumption, as their temperature rises to anything between 10 and 24 °C after being introduced into the mouth at 4 °C. The mass ratio between solid and liquid fats, which depends on the temperature, impacts the organoleptic properties of DG. As the ordinary methods for determining this ratio can only be applied to samples consisting mainly in fat materials, a fat extraction step needs to be added into the analytical process when applied to DG, which prevents the study of the potential impact of their colloidal structure on milk fat fusion behavior. In situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR) was investigated as a method for direct measurements in DG: at temperatures between 20.0 and 70.0 °C, the liquid fat content and the composition of triacylglycerols of the liquid phase (in terms of alkyl chains length) were determined. Spectra of isolated milk fat also enable the quantification of the double bonds of triacylglycerols. Statistical tests showed no significant difference between isolated milk fat and milk fat inside a DG in terms of melting behavior: the fat globule membrane does not seem to have a significant influence on the fat melting behavior. PMID:23464867

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  12. Hot and cold fusion

    SciTech Connect

    Not Available

    1990-08-01

    This article presents an overview of research in cold fusion research and development in cold fusion at the Tokomak Fusion Test Reactor at the Princeton Plasma Physics Lab, and at the inertial containment facility at Lawrence Livermore National Lab. is described.

  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. 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

  15. 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.

  16. 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

  17. Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Yang, Y.; Xu, H.

    2011-10-01

    This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

  18. 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.

  19. 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.

  20. Bloch-symmetric fusion in PdD sub x

    SciTech Connect

    Chubb, T.A. ); Chubb, S.R. )

    1990-07-01

    A theory of solid-state fusion based on the formation of a D{sup +} Bose Bloch condensate (BBC) is summarized. The first step toward fusion is a coalescence reaction that converts a multiple-occupation state of chemical density into a state of nuclear density. In PdD{sub x}, conditions for formation of a BBC are favorable when x is near unity, due to avoidance of lattice strain energy that otherwise contributes to the chemical potential. Fusion obeys a boson in, boson out selection rule and avoids the proton and neutron fluxes of collision-induced fusion. Some cold fusion studies are compatible with the theory and indicate the possibility of largely radiation-free commercial nuclear power from an inexhaustible fuel supply.

  1. Fission Fusion Hybrids: a nearer term application of Fusion

    NASA Astrophysics Data System (ADS)

    Kotschenreuther, M.; Valanju, P.; Mahajan, S.; Covele, B.

    2011-10-01

    Fission-fusion hybrids enjoy unique advantages for addressing long standing societal acceptability issues of nuclear fission power at a much lower level of technical development than a competitive fusion power plant. For waste incineration, hybrids burn intransigent transuranic residues (with the long lived biohazard) from light water reactors (LWRs). The number of hybrids needed is 5-10 times less than the corresponding number of fast reactors (FRs). The highly sub-critical hybrids, with a thermal/epithermal spectrum, incinerate > 95% of the waste in decades rather than the centuries needed for FRs. For fuel production, hybrids can produce fuel for 3-4 times as many LWRs with no fuel reprocessing. Thorium fuel rods exposed to neutrons in the hybrid reach fissile concentrations that enable efficient burning in LWR without the proliferation risks of reprocessing. The proliferation risks of this method are far less than other fuel breeding approaches, including today's gas centrifuge. With this cycle, US Thorium reserves could supply the entire US electricity supply for centuries. The centerpiece of the fuel cycle is a high power density Compact Fusion Neutron Source (major+minor radius ~ 2.5-3.5 m), which is made feasible by the super-X divertor.

  2. 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.

  3. Multisensor image fusion guidelines in remote sensing

    NASA Astrophysics Data System (ADS)

    Pohl, C.

    2016-04-01

    Remote sensing delivers multimodal and -temporal data from the Earth's surface. In order to cope with these multidimensional data sources and to make the most of them, image fusion is a valuable tool. It has developed over the past few decades into a usable image processing technique for extracting information of higher quality and reliability. As more sensors and advanced image fusion techniques have become available, researchers have conducted a vast amount of successful studies using image fusion. However, the definition of an appropriate workflow prior to processing the imagery requires knowledge in all related fields - i.e. remote sensing, image fusion and the desired image exploitation processing. From the findings of this research it can be seen that the choice of the appropriate technique, as well as the fine-tuning of the individual parameters of this technique, is crucial. There is still a lack of strategic guidelines due to the complexity and variability of data selection, processing techniques and applications. This paper gives an overview on the state-of-the-art in remote sensing image fusion including sensors and applications. Putting research results in image fusion from the past 15 years into a context provides a new view on the subject and helps other researchers to build their innovation on these findings. Recommendations of experts help to understand further needs to achieve feasible strategies in remote sensing image fusion.

  4. Status and problems of fusion reactor development.

    PubMed

    Schumacher, U

    2001-03-01

    Thermonuclear fusion of deuterium and tritium constitutes an enormous potential for a safe, environmentally compatible and sustainable energy supply. The fuel source is practically inexhaustible. Further, the safety prospects of a fusion reactor are quite favourable due to the inherently self-limiting fusion process, the limited radiologic toxicity and the passive cooling property. Among a small number of approaches, the concept of toroidal magnetic confinement of fusion plasmas has achieved most impressive scientific and technical progress towards energy release by thermonuclear burn of deuterium-tritium fuels. The status of thermonuclear fusion research activity world-wide is reviewed and present solutions to the complicated physical and technological problems are presented. These problems comprise plasma heating, confinement and exhaust of energy and particles, plasma stability, alpha particle heating, fusion reactor materials, reactor safety and environmental compatibility. The results and the high scientific level of this international research activity provide a sound basis for the realisation of the International Thermonuclear Experimental Reactor (ITER), whose goal is to demonstrate the scientific and technological feasibility of a fusion energy source for peaceful purposes.

  5. Research in theoretical nuclear physics. Final report, April 1, 1993--March 31, 1996

    SciTech Connect

    Udagawa, Takeshi

    1997-08-01

    This report describes the accomplishments in basic research in nuclear physics carried out by the theoretical nuclear physics group in the Department of Physics at the University of Texas at Austin, during the period of April 1, 1993 to March 31, 1996. The work done covers three separate areas, low energy nuclear reactions, intermediate energy physics, and nuclear structure studies. Although the various subjects are spread among different areas, they are all based on two techniques that they have developed in previous years. These techniques are: (a) a powerful method for continuum-random-phase-approximation (CRPA) calculations of the nuclear response; and, (b) the direct reaction approach to complete and incomplete fusion reactions, which enables them to describe on a single footing all the different types of nuclear reactions, i.e., complete fusion, incomplete fusion and direct reactions, in a systematic way based on a single theoretical framework. In this report, the authors first summarize their achievements in these three areas, and then present final remarks.

  6. Experimental study of fusion neutron and proton yields produced by petawatt-laser-irradiated D2-3He or CD4-3He clustering gases

    NASA Astrophysics Data System (ADS)

    Bang, W.; Barbui, M.; Bonasera, A.; Quevedo, H. J.; Dyer, G.; Bernstein, A. C.; Hagel, K.; Schmidt, K.; Gaul, E.; Donovan, M. E.; Consoli, F.; De Angelis, R.; Andreoli, P.; Barbarino, M.; Kimura, S.; Mazzocco, M.; Natowitz, J. B.; Ditmire, T.

    2013-09-01

    We report on experiments in which the Texas Petawatt laser irradiated a mixture of deuterium or deuterated methane clusters and helium-3 gas, generating three types of nuclear fusion reactions: D(d,3He)n, D(d,t)p, and 3He(d,p)4He. We measured the yields of fusion neutrons and protons from these reactions and found them to agree with yields based on a simple cylindrical plasma model using known cross sections and measured plasma parameters. Within our measurement errors, the fusion products were isotropically distributed. Plasma temperatures, important for the cross sections, were determined by two independent methods: (1) deuterium ion time of flight and (2) utilizing the ratio of neutron yield to proton yield from D(d,3He)n and 3He(d,p)4He reactions, respectively. This experiment produced the highest ion temperature ever achieved with laser-irradiated deuterium clusters.

  7. 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

  8. 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

  9. Principles and rationale of the Fusion-Fission Hybrid burner reactor

    NASA Astrophysics Data System (ADS)

    Stacey, Weston M.

    2012-06-01

    The potential advantages of Fusion-Fission Hybrid (FFH) reactors (relative to critical fast reactors) for closing the back end of the nuclear fuel cycle are discussed. The choices of fission and fusion technologies for FFH burner reactors that would fission the transuranics remaining in spent fuel discharged from nuclear power reactors are summarized. The conceptual design and fuel cycle performance of the SABR FFH burner reactor are presented, and a fusion power development schedule with a symbiotic dual FFH path is outlined.

  10. 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.

  11. 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.

  12. Status of cold fusion (2010)

    NASA Astrophysics Data System (ADS)

    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.

  13. 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.

  14. Superheavy Elements - Achievements and Challenges

    SciTech Connect

    Ackermann, Dieter

    2009-03-04

    The search for superheavy elements (SHE) has yielded exciting results for both the 'cold fusion' approach with reactions employing Pb and Bi targets and the ''hot fusion'' reactions with {sup 48}Ca beams on actinide targets. The most recent activities at GSI were the successful production of a more neutron rich isotope of element 112 in the reaction {sup 48}Ca+{sup 238}U confirming earlier result from FLNR, and the attempt to synthesize an isotope with Z 120 in the reaction {sup 64}Ni+{sup 238}U. Apart from the synthesis of new elements, advanced nuclear structure studies for heavy and super heavy elements promise a detailed insight in the properties of nuclear matter under the extreme conditions of high Z and A. The means are evaporation residue(ER)-{alpha}-{alpha} and -{alpha}-{gamma} coincidence techniques applied after separation of the reaction products from the beam. Recent examples of interesting physics to be discovered in this region of the chart of nuclides are the investigation of K-isomers observed for {sup 252,254}No and indicated for {sup 270}Ds. Fast chemistry and precision mass measurements deliver in addition valuable information on the fundamental properties of the SHE.

  15. 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.

  16. 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…

  17. Fusion facility siting considerations

    NASA Astrophysics Data System (ADS)

    Bussell, G. T.

    1985-02-01

    Inherent in the fusion program's transition from hydrogen devices to commercial power machines is a general increase in the size and scope of succeeding projects. This growth will lead to increased emphasis on safety, environmental impact, and the external effects of fusion in general, and of each new device in particular. An important consideration in this regard is site selection. Major siting issues that may affect the economics, safety, and environmental impact of fusion are examined.

  18. Meteorite fusion crust variability.

    NASA Astrophysics Data System (ADS)

    Thaisen, Kevin G.; Taylor, Lawrence A.

    2009-06-01

    Two assumptions commonly employed in meteorite interpretation are that fusion crust compositions represent the bulk-rock chemistry of the interior meteorite and that the vesicles within the fusion crust result from the release of implanted solar wind volatiles. Electron microprobe analyses of thin sections from lunar meteorite Miller Range (MIL) 05035 and eucrite Bates Nunataks (BTN) 00300 were performed to determine if the chemical compositions of the fusion crust varied and/or represented the published bulk rock composition. It was determined that fusion crust compositions are significantly influenced by the incorporation of fragments from the substrate, and by the composition and grain size of those minerals. Because of compositional heterogeneities throughout the meteorite, one cannot assume that fusion crust composition represents the bulk rock composition. If the compositional variability within the fusion crust and mineralogical differences among thin sections goes unnoticed, then the perceived composition and petrogenetic models of formation will be incorrect. The formation of vesicles within these fusion crusts were also compared to current theories attributing vesicles to a solar wind origin. Previous work from the STONE-5 experiment, where terrestrial rocks were exposed on the exterior of a spacecraft heatshield, produced a vesicular fusion crust without prolonged exposure to solar wind suggesting that the high temperatures experienced by a meteorite during passage through the Earth's atmosphere are sufficient to cause boiling of the melt. Therefore, the assumption that all vesicles found within a fusion crust are due to the release of implanted volatiles of solar wind may not be justified.

  19. Views on Inertial Fusion Energy Development (lirpp Vol. 11)

    NASA Astrophysics Data System (ADS)

    Nakai, S.

    2016-10-01

    It is my great honor to receive the Edward Teller Award. Representing the Institute of Laser Engineering, Osaka University, I would like to appreciate your favorite recognition on our achievements in laser fusion research...

  20. Low-Convergence Magnetized Liner Inertial Fusion

    NASA Astrophysics Data System (ADS)

    Slutz, Stephen; Vesey, Roger; Sinars, Daniel; Sefkow, Adam

    2013-10-01

    Numerical simulations indicate that pulsed-power driven liner-implosions could produce substantial fusion yields if the deuterium-tritium (DT) fuel is first magnetized and preheated [S.A. Slutz et al., Phys. Plasmas 17, 056303 (2010)]. As with all inertial fusion, the implosions could be degraded by the Rayleigh-Taylor instability. Since highly convergent implosions are more susceptible to this instability, we have explored the necessary conditions to obtain significant fusion yield with low-convergence liner-implosions. Such low-convergence implosions can be obtained if the fuel is sufficiently preheated and magnetized. We present analytic and numerical studies of laser plasma heating, which indicate that low convergence implosions should be possible with sufficient laser energy. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contra.

  1. Visual programming environment for multisensor data fusion

    NASA Astrophysics Data System (ADS)

    Hall, David L.; Kasmala, Gerald

    1996-06-01

    In recent years, numerous multisensor data fusion systems have been developed for a wide variety of applications. Defense related applications include; automatic target recognition systems, identification-friend-foe-neutral, automated situation assessment and threat assessment systems, and systems for smart weapons. Non-defense applications include; robotics, condition-based maintenance, environmental monitoring, and medical diagnostics. For each of these applications, multiple sensor data are combined to achieve inferences which are not generally possible using only a single sensor. Implementation of these data fusion systems often involves a significant amount of effort. In particular, software must be developed for components such as data base access, human computer interfaces and displays, communication software, and data fusion algorithms. While commercial software packages exist to assist development of data bases, communications, and human computer interfaces, there are no general purpose packages available to support the implementation of the data fusion algorithms. This paper describes a visual programming tool developed to assist in rapid prototyping of data fusion systems. This toolkit is modeled after the popular tool, Khoros, used by the image processing community. The tool described here is written in visual C, and provides the capability to rapidly implement and apply data fusion algorithms. An application to condition based maintenance is described.

  2. Detail preserving exposure fusion for a dual sensor camera

    NASA Astrophysics Data System (ADS)

    Chen, Kuo; Chen, Yueting; Feng, Huajun; Xu, Zhihai

    2014-11-01

    Dual sensor cameras are widely used to capture multi-exposure image of high dynamic range scene without ghost effect. The local details and luminance contrast can not be achieved well at the same time by conventional exposure fusion. A novel technique of exposure fusion is proposed to balance the local details and global luminance adaptively for dual sensor camera. Such fusion weight map is calculated by a new down-up-sampling method. And then, a guided filter is employed to refine the weight map and exposure fusion is realized using pixel by pixel approach. Finally, multiple experiments are carried out and six common exposure fusion algorithms are compared to verify the proposed exposure fusion technique. The experimental results show that the proposed method performs excellently and robustly with highest spatial frequency and visual fidelity.

  3. Fundamentals in Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Basdevant, Jean-Louis, Rich, James, Spiro, Michael

    This course on nuclear physics leads the reader to the exploration of the field from nuclei to astrophysical issues. Much nuclear phenomenology can be understood from simple arguments such as those based on the Pauli principle and the Coulomb barrier. This book is concerned with extrapolating from such arguments and illustrating nuclear systematics with experimental data. Starting with the basic concepts in nuclear physics, nuclear models, and reactions, the book covers nuclear decays and the fundamental electro-weak interactions, radioactivity, and nuclear energy. After the discussions of fission and fusion leading into nuclear astrophysics, there is a presentation of the latest ideas about cosmology. As a primer this course will lay the foundations for more specialized subjects. This book emerged from a series of topical courses the authors delivered at the Ecole Polytechnique and will be useful for graduate students and for scientists in a variety of fields.

  4. 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.

  5. Coatings for laser fusion

    SciTech Connect

    Lowdermilk, W.H.

    1981-12-18

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors.

  6. 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.

  7. 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…

  8. Clinical and Radiological Outcomes of Segmental Spinal Fusion in Transforaminal Lumbar Interbody Fusion with Spinous Process Tricortical Autograft

    PubMed Central

    Tangviriyapaiboon, Teera

    2014-01-01

    Study Design A retrospective study. Purpose To investigate clinical and radiological outcomes when using spinous process as a tricortical autograft for segmental spinal fusion in transforaminal lumbar interbody fusion (TLIF). Overview of Literature Interbody spinal fusion is one of the important procedures in spinal surgery. Many types of autografts are harvested at the expense of complications. Clinical and radiographic results of patients who underwent TLIF with intraoperative harvested spinous process autograft in Prasat Neurological Institue, Bangkok, Thailand, were assessed as new technical innovation. Methods Between October 2005 to July 2009, 30 cases of patients who underwent TLIF with spinous process tricortical autograft were included. Clinical evaluations were assessed by visual analog scales (VAS) and Prolo functional and economic scores at the preoperation and postoperation and at 2 years postoperation. Static and dynamic plain radiograph of lumbar spine were reviewed for achievement of fusion. Results Initial successful fusion time in lumbar interbody fusion with spinous process tricortical autograft was 4.72 months (range, 3.8-6.1 months) postoperation and 100% fusion rate was reported at 2 years. Our initial successful fusion time in lumbar interbody fusion was compared to the other types of grafts in previous literatures. Conclusions The use of intraoperative harvested spinous process tricortical autograft has overcome many disadvantages of harvesting autograft with better initial successful fusion time (4.72 months). VAS and Prolo scores showed some improvement in the outcomes between the preoperative and postoperative periods. PMID:24761199

  9. Influenza Virus-Mediated Membrane Fusion: Determinants of Hemagglutinin Fusogenic Activity and Experimental Approaches for Assessing Virus Fusion

    PubMed Central

    Hamilton, Brian S.; Whittaker, Gary R.; Daniel, Susan

    2012-01-01

    Hemagglutinin (HA) is the viral protein that facilitates the entry of influenza viruses into host cells. This protein controls two critical aspects of entry: virus binding and membrane fusion. In order for HA to carry out these functions, it must first undergo a priming step, proteolytic cleavage, which renders it fusion competent. Membrane fusion commences from inside the endosome after a drop in lumenal pH and an ensuing conformational change in HA that leads to the hemifusion of the outer membrane leaflets of the virus and endosome, the formation of a stalk between them, followed by pore formation. Thus, the fusion machinery is an excellent target for antiviral compounds, especially those that target the conserved stem region of the protein. However, traditional ensemble fusion assays provide a somewhat limited ability to directly quantify fusion partly due to the inherent averaging of individual fusion events resulting from experimental constraints. Inspired by the gains achieved by single molecule experiments and analysis of stochastic events, recently-developed individual virion imaging techniques and analysis of single fusion events has provided critical information about individual virion behavior, discriminated intermediate fusion steps within a single virion, and allowed the study of the overall population dynamics without the loss of discrete, individual information. In this article, we first start by reviewing the determinants of HA fusogenic activity and the viral entry process, highlight some open questions, and then describe the experimental approaches for assaying fusion that will be useful in developing the most effective therapies in the future. PMID:22852045

  10. 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.

  11. 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. PMID:27659994

  12. 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.

  13. 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.

  14. 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.

  15. The in-situ diagnosis of plasma-wall interactions on magnetic fusion devices with accelerators

    NASA Astrophysics Data System (ADS)

    Hartwig, Zachary

    2013-10-01

    We present the first in-situ, time-resolved measurements of low-Z isotope composition and deuterium retention over a large plasma-facing component (PFC) surface area in a magnetic fusion device. These critical measurements were made using a novel diagnostic technique based on the analysis of induced nuclear reactions from PFC surfaces on the Alcator C-Mod tokamak. Achieving an integrated understanding of plasma physics and materials science in magnetic fusion devices is severely hindered by a dearth of in-situ PFC surface diagnosis. Plasma-wall interactions, such as the erosion/redeposition of PFC material, the evolution of PFC surface isotope composition, and fusion fuel retention present significant plasma physics and materials science challenges for long pulse or steady-state devices. Our diagnostic uses a compact (~1 meter), high-current (~1 milliamp) radio-frequency quadrupole accelerator to inject ~1 MeV deuterons into the vacuum vessel. We control the tokamak's magnetic fields - in between plasma shots - to steer the deuterons to PFC surfaces, where they induce high-Q nuclear reactions with low-Z isotopes in the first ~10 microns of material. Analysis of the induced gamma and neutron energy spectra provides quantitative reconstruction of PFC surface conditions. This nondestructive, in-situ technique achieves PFC surface composition measurements with plasma shot-to-shot time resolution and 1 centimeter spatial resolution over large PFC areas. Work supported by U.S. DOE Grant DE-FG02-94ER54235 and Cooperative Agreement DE-FC02-99ER54512.

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

    NASA Astrophysics Data System (ADS)

    Moses, Edward I.

    2009-10-01

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

  17. 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.

  18. Fusion Physics Toward ITER

    NASA Astrophysics Data System (ADS)

    Stambaugh, R. D.

    2006-04-01

    Stars are powered by fusion, the energy released by fusing together light nuclei, using gravitational confinement of plasma. Fusion on earth will be done in a 100 million degree plasma made of deuterium and tritium and confined by magnetic fields or inertia. The worldwide fusion research community will construct ITER, the first experiment that will burn a DT plasma by copious fusion reactions. ITER's nominal goal is to create 500 MW of fusion power. An energy gain of 10 will mean the plasma is dominantly self-heated by the fusion-produced alpha particles. ITER's all superconducting magnet technology and steady-state heat removal technology will enable nominal 400 s pulses to allow the study of burning plasmas on the longest intrinsic timescale of the confined plasma - diffusive redistribution of the electrical currents in the plasma. The advances in magnetic confinement physics that have led to this opportunity will be described, as well as the research opportunities afforded by ITER. The physics of confining stable plasmas and heating them will produce the high gain state in ITER. Sustained burn will come from the physics of controlling currents in plasmas and how the hot plasma is interfaced to its room temperature surroundings. ITER will provide our first experience with how fusion plasma self-heating will profoundly affect the complex, interlinked physical processes that occur in confined plasmas.

  19. Muon-catalyzed fusion theory: Introduction and review

    SciTech Connect

    Cohen, J.S.

    1989-01-01

    Muon-catalyzed fusion ({mu}CF) has proved to be a fruitful subject for basic physics research as well as a source of cold nuclear fusion. Experiments have demonstrated that over 100 fusions per muon can be catalyzed by formation of the dt{mu} molecule in mixtures of deuterium and tritium. After a brief review of the subject's history, the dt{mu} catalysis cycle and the principal relations used in its analysis are described. Some of the important processes in the {mu}CF cycle are then discussed. Finally, the status of current research is appraised. 52 refs., 7 figs.

  20. Heavy ion fusion--Using heavy ions to make electricity

    SciTech Connect

    Celata, C.M.

    2004-03-15

    The idea of using nuclear fusion as a source of commercial electrical power has been pursued worldwide since the 1950s. Two approaches, using magnetic and inertial confinement of the reactants, are under study. This paper describes the difference between the two approaches, and discusses in more detail the heavy-ion-driven inertial fusion concept. A multibeam induction linear accelerator would be used to bring {approx}100 heavy ion beams to a few GeV. The beams would then heat and compress a target of solid D-T. This approach is unique among fusion concepts in its ability to protect the reaction chamber wall from neutrons and debris.

  1. 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.

  2. Cost assessment of a generic magnetic fusion reactor

    SciTech Connect

    Sheffield, J.; Dory, R.A.

    1984-01-01

    A generic magnetic fusion reactor model is used to determine the conditions under which electricity generation from fusion would be economically viable. The use of a generic model helps to circumvent problems associated with present perceptions of magnetic configurations. It helps also to decouple those limitations set by generic constraints such as nuclear cross sections from those set by the state of development today. The model shows that only moderate advances are required in reactor characteristics over current designs to make an economically attractive magnetic fusion reactor.

  3. 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.

  4. Nuclear hostages

    SciTech Connect

    O'Keefe, B.J.

    1983-01-01

    Classical physics since Roentgen's discovery of X-rays led quickly to work on atomic structure and the Nuclear Age. The author traces the history of decisions to pursue nuclear fission, the organization of the Manhattan Project, the compromises of the 1963 test ban treaty, and the dilemma of nuclear weapons development and deployment that now hold mankind hostage. He reviews the rationale for limited nuclear war, first strike, massive retaliation, non-proliferation, and the Strategic Arms Limitation Talks (SALT) treaties. He argues that the concepts of mobile MX weapons, fratricide, and population dispersal for civil defense are unworkable, suggesting a program of unilaterally withdrawing tactical nuclear weapons from Europe and strengthening intelligence and law-enforcement powers to withstand terrorist activity. Economic cooperation and political reconciliation may take a generation to achieve, but should be our national goal.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. A brief overview of the European Fusion File (EFF) Project

    NASA Astrophysics Data System (ADS)

    Kellett, M. A.; Forrest, R. A.; Batistoni, P.; EFF Project members

    2004-04-01

    The European Fusion File (EFF) Project is a collaborative project with work funded by the European Fusion Development Agreement (EFDA). The emphasis is on the pooling of resources and removal of duplication of effort, leading to the efficient development of two types of nuclear data libraries for use in fusion power plant design and operation studies. The two branches consist of, on the one hand, a general purpose file for modelling and design capabilities and, second, an activation file for the calculation and simulation of dose rates and energy release during operation of a future power plant. Efforts are directed towards a continued improvement of the quality of the nuclear data needed for these analyses. The OECD Nuclear Energy Agency's Data Bank acts as the central repository for the files and all information discussed during twice yearly meetings. It offers its services at no charge to the Project.

  11. SKIDS data fusion project

    NASA Astrophysics Data System (ADS)

    Greenway, Phil

    1992-04-01

    The European Community's strategic research initiative in information technology (ESPRIT) has been in place for nearly five years. An early example of the pan-European collaborative projects being conducted under this initiative is 'SKIDS': Signal and Knowledge Integration with Decisional Control for Multisensory Systems. This four year project, which is approaching completion, aims to build a real-time multisensor perception machine. This machine will be capable of performing data fusion, interpretation, situation assessment, and resource allocation tasks, under the constraints of both time and resource availability, and in the presence of uncertain data. Of the many possible applications, the surveillance and monitoring of a semi-automated 'factory environment' has been chosen as a challenging and representative test scenario. This paper presents an overview of the goals and objectives of the project, the makeup of the consortium, and roles of the members within it, and the main technical achievements to data. In particular, the following are discussed: relevant application domains, and the generic requirements that can be inferred from them; sensor configuration, including choice, placement, etc.; control paradigms, including the possible trade-offs between centralized, hierarchical, and decentralized approaches; the corresponding hardware architectural choices, including the need for parallel processing; and the appropriate software architecture and infra-structure required to support the chosen task oriented approach. Specific attention is paid to the functional decomposition of the system and how the requirements for control impact the organization of the identified interpretation tasks. Future work and outstanding problems are considered in some concluding remarks. By virtue of limited space, this paper is descriptive rather than explanatory.

  12. Sensor fusion for hand-held multisensor landmine detection

    NASA Astrophysics Data System (ADS)

    Agarwal, Sanjeev; Chander, Venkat S.; Palit, Partha P.; Stanley, Joe; Mitchell, O. Robert

    2001-10-01

    Sensor fusion issues in a streamlined assimilation of multi-sensor information for landmine detection are discussed. In particular multi-sensor fusion in hand-held landmine detection system with ground penetrating radar (GPR) and metal detector sensors is investigated. The fusion architecture consists of feature extraction for individual sensors followed by a feed-forward neural network training to learn the feature space representation of the mine/no-mine classification. A correlation feature from GPR, and slope and energy feature from metal detector are used for discrimination. Various fusion strategies are discussed and results compared against each other and against individual sensors using ROC curves for the available multi-sensor data. Both feature level and decision level fusion have been investigated. Simple decision level fusion scheme based on Dempster-Shafer evidence accumulation, soft AND, MIN and MAX are compared. Feature level fusion using neural network training is shown to provide best results. However comparable performance is achieved using decision level sensor fusion based on Dempster-Shafer accumulation. It is noted that, the above simple feed-forward fusion scheme lacks a means to verify detections after a decision has been made. New detection algorithms that are more than anomaly detectors are needed. Preliminary results with features based on independent component analysis (ICA) show promising results towards this end.

  13. Inertial fusion commercial power plants

    NASA Astrophysics Data System (ADS)

    Logan, B. Grant

    1994-09-01

    This presentation discusses the motivation for inertial fusion energy, a brief synopsis of five recently-completed inertial fusion power plant designs, some general conclusions drawn from these studies, and an exmaple of an IEE hydrogen synfuel plant to suggest that future fusion studies consider broadening fusion use to low-emission fuels production as well as electricity.

  14. Label fusion strategy selection.

    PubMed

    Robitaille, Nicolas; Duchesne, Simon

    2012-01-01

    Label fusion is used in medical image segmentation to combine several different labels of the same entity into a single discrete label, potentially more accurate, with respect to the exact, sought segmentation, than the best input element. Using simulated data, we compared three existing label fusion techniques-STAPLE, Voting, and Shape-Based Averaging (SBA)-and observed that none could be considered superior depending on the dissimilarity between the input elements. We thus developed an empirical, hybrid technique called SVS, which selects the most appropriate technique to apply based on this dissimilarity. We evaluated the label fusion strategies on two- and three-dimensional simulated data and showed that SVS is superior to any of the three existing methods examined. On real data, we used SVS to perform fusions of 10 segmentations of the hippocampus and amygdala in 78 subjects from the ICBM dataset. SVS selected SBA in almost all cases, which was the most appropriate method overall. PMID:22518113

  15. Fusion-power demonstration

    NASA Astrophysics Data System (ADS)

    Henning, C. D.; Logan, B. G.; Carlson, G. A.; Neef, W. S.; Moir, R. W.; Campbell, R. B.; Botwin, R.; Clarkson, I. R.; Carpenter, T. J.

    1983-03-01

    As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment.

  16. Spinal fusion - series (image)

    MedlinePlus

    ... muscles hold the graft in place until it fuses with the vertebrae. A fusion will setup within ... hollow threaded titanium or carbon fiber cylinder to fuse two vertebrae together. The diseased disk is removed ...

  17. Magnetized Target Fusion collaboration

    NASA Astrophysics Data System (ADS)

    Intrator, Thomas

    2004-11-01

    Magnetized Target Fusion (MTF) may be a low cost path to fusion, in a regime that is intermediate between magnetic and inertial fusion energy. It requires compression of a magnetized target plasma and consequent heating to fusion relevant conditions inside a converging flux conserver. We hope to demonstrate the physics basis for MTF, with a Field Reversed Configuration (FRC) target plasma to be translated axially to a compression region. We show recent and improved FRC formation data, example deformable liner implosions, and a conceptual design for the upcoming translation experiments, and describe a multi institution collaboration. The FRC is an elongated, compact toroid equilibrium that is extreme among magnetic configurations, and relaxed to a non force free state. There is high plasma beta, small toroidal field, cross-field diamagnetic current and flows, vanishing rotational transform, magnetic shear, helicity and anomalously large resistivity. Scientific issues include MTF with and without FRC's, and fundamental plasma physics beyond MHD, relevant to geophysical and astrophysical phenomena.

  18. Fusion moves for Markov random field optimization.

    PubMed

    Lempitsky, Victor; Rother, Carsten; Roth, Stefan; Blake, Andrew

    2010-08-01

    The efficient application of graph cuts to Markov Random Fields (MRFs) with multiple discrete or continuous labels remains an open question. In this paper, we demonstrate one possible way of achieving this by using graph cuts to combine pairs of suboptimal labelings or solutions. We call this combination process the fusion move. By employing recently developed graph-cut-based algorithms (so-called QPBO-graph cut), the fusion move can efficiently combine two proposal labelings in a theoretically sound way, which is in practice often globally optimal. We demonstrate that fusion moves generalize many previous graph-cut approaches, which allows them to be used as building blocks within a broader variety of optimization schemes than were considered before. In particular, we propose new optimization schemes for computer vision MRFs with applications to image restoration, stereo, and optical flow, among others. Within these schemes the fusion moves are used 1) for the parallelization of MRF optimization into several threads, 2) for fast MRF optimization by combining cheap-to-compute solutions, and 3) for the optimization of highly nonconvex continuous-labeled MRFs with 2D labels. Our final example is a nonvision MRF concerned with cartographic label placement, where fusion moves can be used to improve the performance of a standard inference method (loopy belief propagation).

  19. 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.

  20. 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.