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Sample records for enhanced fusion reaction

  1. Fusion enhancement in the reactions of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Bian Baoan; Zhang Fengshou; Zhou Hongyu

    2009-01-01

    The neutron-rich fusion reactions are investigated systematically using the improved isospin dependent quantum molecular dynamics model. By studying the systematic dependence of fusion barrier on neuron excess, we find the enhancement of the fusion cross sections for neutron-rich nuclear reactions that give the lowered static Coulomb barriers. The calculated fusion cross sections agree quantitatively with the experimental data. We further discuss the mechanism of the fusion enhancement of the cross sections for neutron-rich nuclear reactions by analyzing the dynamical lowering of the Coulomb barrier that is attributed to the enhancement of the N/Z ratio at the neck region.

  2. Reaction mechanisms in heavy ion fusion

    Directory of Open Access Journals (Sweden)

    Lubian J.

    2011-10-01

    Full Text Available We discuss the reaction mechanisms involved in heavy ion fusion. We begin with collisions of tightly bound systems, considering three energy regimes: energies above the Coulomb barrier, energies just below the barrier and deep sub-barrier energies. We show that channel coupling effects may influence the fusion process at above-barrier energies, increasing or reducing the cross section predicted by single barrier penetration model. Below the Coulomb barrier, it enhances the cross section, and this effect increases with the system’s size. It is argued that this behavior can be traced back to the increasing importance of Coulomb coupling with the charge of the collision partners. The sharp drop of the fusion cross section observed at deep sub-barrier energies is addressed and the theoretical approaches to this phenomenon are discussed. We then consider the reaction mechanisms involved in fusion reactions of weakly bound systems, paying particular attention to the calculations of complete and incomplete fusion available in the literature.

  3. Applications of Skyrme energy-density functional to fusion reactions spanning the fusion barriers

    International Nuclear Information System (INIS)

    Liu Min; Wang, Ning; Li Zhuxia; Wu Xizhen; Zhao Enguang

    2006-01-01

    The Skyrme energy density functional has been applied to the study of heavy-ion fusion reactions. The barriers for fusion reactions are calculated by the Skyrme energy density functional with proton and neutron density distributions determined by using restricted density variational (RDV) method within the same energy density functional together with semi-classical approach known as the extended semi-classical Thomas-Fermi method. Based on the fusion barrier obtained, we propose a parametrization of the empirical barrier distribution to take into account the multi-dimensional character of real barrier and then apply it to calculate the fusion excitation functions in terms of barrier penetration concept. A large number of measured fusion excitation functions spanning the fusion barriers can be reproduced well. The competition between suppression and enhancement effects on sub-barrier fusion caused by neutron-shell-closure and excess neutron effects is studied

  4. A dynamical theory of incomplete fusion reactions: The breakup-fusion reaction approach

    International Nuclear Information System (INIS)

    Udagawa, T.

    1984-01-01

    A dynamical theory of partial fusion reactions is presented, which may fill the gap between direct and compound nuclear reaction theories. With the new theory one can calculate partial fusion taking place in three-body (and many more) channels reached via direct reactions, e.g., breakup and knockout reactions. The authors present first the results for the cross section for such reactions, taking as an example breakup followed by fusion. They then discuss a physical picture which emerges from their theory, namely that the partial fusion reactions, particularly of the massive-transfer type, take place in a so-called deep peripheral region. It is also shown that the deep peripheral character of such processes diminishes as the mass of the fused system decreases, so that the reactions essentially evolve to the usual peripheral character. Finally, comparisons are made of results of numerical calculations with experimental data, taking as an example the /sup 159/Tb(/sup 14/N,α) reaction with E/sub lab/ = 95 MeV

  5. Fusion reaction using low energy neutron-excess nucleus beam

    International Nuclear Information System (INIS)

    Fukuda, Tomokazu

    1994-01-01

    The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

  6. Measurement of inertial confinement fusion reaction rate

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Tang Daorun; Liu Shenye; Huang Tianxuan; Liu Yonggang; Xu Tao; Chen Ming; Mei Yu

    2011-01-01

    Fusion reaction rate is an important parameter for measuring compression during the implosion in inertial confinement fusion experiment. We have developed a system for fusion reaction history measurement with high temporal resolution. The system is composed of plastic scintillator and nose cone, optical system and streak camera. We have applied this system on the SG-III prototype for fusion reaction rate measuring. For the first time, fusion reaction rate history have been measured for deuterium-tritium filled targets with neutrons yields about 10 10 . We have analyzed possible influence factor during fusion reaction rate measuring. It indicates that the instrument measures fusion reaction bang time at temporal resolutions as low as 30 ps.(authors)

  7. Detailed determination of the fusion nuclear radius in reactions involving weakly bound projectiles

    International Nuclear Information System (INIS)

    Gomez Camacho, A.; Aguilera, E. F.; Quiroz, E. M.

    2007-01-01

    A detailed determination of the fusion radius parameter is performed within the Distorted Wave Born Approximation for reactions involving weakly bound projectiles. Specifically, a simultaneous X 2- analysis of elastic and fusion cross section data is done using a Woods-Saxon potential with volume and surface parts. The volume part is assumed to be responsible for fusion reactions while the surface part for all other direct reactions. It is proved that in order to fit fusion data, particularly for energies below the Coulomb barrier where fusion is enhanced, it is necessary to have a value of around 1.4 fm for the fusion radial parameter of the fusion potential (W F ). This value is much higher than that frequently used in Barrier Penetration models (1.0 fm). The calculations are performed for reactions involving the weakly bound projectile 9 Be with several medium mass targets. (Author)

  8. Outline of cold nuclear fusion reaction

    International Nuclear Information System (INIS)

    Tachikawa, Enzo

    1991-01-01

    In 2010, as the total supply capacity of primary energy, 666 million liter is anticipated under the measures of thorough energy conservation. The development of energy sources along the energy policy based on environment preservation, safety, the quantity of resources and economy is strongly demanded. The nuclear power generation utilizing nuclear fission has been successfully carried out. As the third means of energy production, the basic research and technical development have been actively advanced on the energy production utilizing nuclear fusion reaction. The main object of the nuclear fusion research being advanced now is D-D reaction and D-T reaction. In order to realize low temperature nuclear fusion reaction, muon nuclear fusion has been studied so far. The cold nuclear fusion reaction by the electrolysis of heavy water has been reported in 1989, and its outline is ixplained in this report. The trend of the research on cold nuclear fusion is described. But the possibility of cold nuclear fusion as an energy source is almost denied. (K.I.)

  9. Fusion enhancement/suppression and irreversibility in reactions induced by weakly bound nuclei

    International Nuclear Information System (INIS)

    Gomes, P.R.S.; Lubian, J.; Canto, L.F.; Chamon, L.C.; Crema, E.; Hussein, M.S.

    2011-01-01

    We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with the situation when there is no-halo. We introduce dimensionless fusion functions and energy variable quantity to investigate systematical trends in the fusion cross sections of weakly bound nuclei at near-barrier energies. We observe very clearly complete fusion suppression at energies above the barrier due to dynamic effects of the breakup on fusion. We explain this suppression in terms of the repulsive polarization potential produced by the breakup. (author)

  10. A light water excess heat reaction suggests that cold fusion may be alkali-hydrogen fusion

    International Nuclear Information System (INIS)

    Bush, R.T.

    1992-01-01

    This paper reports that Mills and Kneizys presented data in support of a light water excess heat reaction obtained with an electrolytic cell highly reminiscent of the Fleischmann-Pons cold fusion cell. The claim of Mills and Kneizys that their excess heat reaction can be explained on the basis of a novel chemistry, which supposedly also explains cold fusion, is rejected in favor of their reaction being, instead, a light water cold fusion reaction. It is the first known light water cold fusion reaction to exhibit excess heat, it may serve as a prototype to expand our understanding of cold fusion. From this new reactions are deduced, including those common to past cold fusion studies. This broader pattern of nuclear reactions is typically seen to involve a fusion of the nuclides of the alkali atoms with the simplest of the alkali-type nuclides, namely, protons, deuterons, and tritons. Thus, the term alkali-hydrogen fusion seems appropriate for this new type of reaction with three subclasses: alkali-hydrogen fusion, alkali-deuterium fusion, and alkali-tritium fusion. A new three-dimensional transmission resonance model (TRM) is sketched. Finally, preliminary experimental evidence in support of the hypothesis of a light water nuclear reaction and alkali-hydrogen fusion is reported. Evidence is presented that appears to strongly implicate the transmission resonance phenomenon of the new TRM

  11. On fusion/fission chain reactions in the Fleischmann-Pons cold fusion experiment

    International Nuclear Information System (INIS)

    Anghaie, S.; Froelich, P.; Monkhorst, H.J.

    1990-01-01

    In this paper the possibility of fusion/fission chain reactions following d-d source reactions in electrochemical cold fusion experiments have been investigated. The recycling factors for the charged particles in fusion reactions with consumable nuclei deuteron, 6 Li nd 7 Li, are estimated. It is concluded that, based on the established nuclear fusion cross sections and electronic stopping power, the recycling factor is four to five orders of magnitude less than required for close to critical conditions. It is argued that the cross generation of charged particles by neutrons does not play a significant role in this process, even if increased densities at the surface of electrodes do occur

  12. Fusion hindrance in reactions with very heavy ions: Border between normal and hindered fusion

    International Nuclear Information System (INIS)

    Shen Caiwan; Li Qingfeng; Boilley, David; Shen Junjie; Abe, Yasuhisa

    2011-01-01

    The fusion hindrance in heavy-ion collisions is studied in the framework of the two-center liquid drop model. It appears that the neck and the radial degrees of freedom might both be hampered by an inner potential barrier on their path between the contact configuration to the compound nucleus. Heavy-ion reactions with and without the two kinds of fusion hindrance are classified through systematic calculations. It is found that the number of reactions without radial fusion hindrance is much smaller than that without neck fusion hindrance, and for both kinds of fusion hindrance the number of reactions without fusion hindrance at small mass-asymmetry parameter α is smaller than that at large α. In the formation of a given compound nucleus, if a reaction with α c is not hindered, then other reactions with α>α c are also not hindered, as is well known experimentally.

  13. Systematic study of sub-barrier fusion enhancement in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Aleixo, A N; Barbosa, V C; Canto, L F; Donangelo, R [Universidade Federal Rural do Rio de Janeiro (Brazil). Dept. de Fisica

    1989-08-14

    A systematic study of the heavy-ion fusion-cross-section enhancement at sub-barrier energies is carried out. The asymptotic energy shift introduced in a previous paper as a measure of this enhancement is considered from a theoretical point of view. It is claimed that this energy shift is composed of two terms: One of them is related to the bulk properties of nuclear matter, and the other corresponds to deviations depending on the specific nuclear structure of the collision partners. We show that the former can be approximately described by the neck-formation model for fusion and the latter is frequently a consequence of static deformation or vibrational excitation of the projectile and/or the target. A comparison of the neck-formation effects with those arising from neutron flow suggests that there is a connection between these two mechanisms. (orig.).

  14. Fusion chain reaction - a chain reaction with charged particles

    International Nuclear Information System (INIS)

    Peres, A.; Shvarts, D.

    1975-01-01

    When a DT-plasma is compressed to very high density, the particles resulting from nuclear reactions give their energy mostly to D and T ions, by nuclear collisions, rather than to electrons as usual. Fusion can thus proceed as a chain reaction, without the need of thermonuclear temperatures. In this paper, we derive relations for the suprathermal ion population created by a fusion reaction. Numerical integration of these equations shows that a chain reaction can proceed in a cold infinite DT-plasma at densities above 8.4x10 27 ions.cm -3 . Seeding the plasma with a small amount of 6 Li reduces the critical density to 7.2x10 27 ions.cm -3 (140000times the normal solid density). (author)

  15. Verification of cold nuclear fusion reaction, (1)

    International Nuclear Information System (INIS)

    Yoshida, Zenko; Aratono, Yasuyuki; Hirabayashi, Takakuni

    1991-01-01

    Can cold nuclear fusion reaction occur as is expected? If it occurs, what extent is its reaction probability? At present after 2 years elapsed since its beginning, the clear solution of these questions is not yet obtained. In many reaction systems employing different means, the experiments to confirm the cold nuclear fusion reaction have been attempted. In order to confirm that the nuclear fusion reaction of deuterium mutually has occurred, the neutrons, He-3, protons, tritium or generated heat, which were formed by the reaction and released from the system, are measured. Since it is considered that the frequency of the occurrence at normal temperature of the reaction is very low, it is necessary to select the most suitable method upon evaluating the limit of detection peculiar to the measuring methods. The methods of measuring neutrons, protons, gamma ray and generated heat, and the reaction systems by electrolytic process and dry process are explained. The detection of plural kinds of the reaction products and the confirmation of synchronism of signals are important. (K.I.)

  16. Fusion and reactions of exotic nuclei

    Directory of Open Access Journals (Sweden)

    Sánchez-Benítez A.M.

    2011-10-01

    Full Text Available Close to the drip lines, the scattering cross sections of halo nuclei show a different behaviour as compared to the tightly bound projectiles of the stability line. Several experiments carried out in the last decade have been dedicated to investigate the competition between transfer, breakup and fusion channels at energies around and below the Coulomb barrier. The rather complex scenario gives rise to conflicting conclusions concerning the effect of breakup and transfer on reaction dynamics and the sub-barrier fusion process. In this work we discuss recent experimental findings in fusion and reactions of 6He halo nucleus at energies around the Coulomb barrier.

  17. Influence of collective nonideal shielding on fusion reaction in partially ionized classical nonideal plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

    The collective nonideal effects on the nuclear fusion reaction process are investigated in partially ionized classical nonideal hydrogen plasmas. The effective pseudopotential model taking into account the collective and plasma shielding effects is applied to describe the interaction potential in nonideal plasmas. The analytic expressions of the Sommerfeld parameter, the fusion penetration factor, and the cross section for the nuclear fusion reaction in nonideal plasmas are obtained as functions of the nonideality parameter, Debye length, and relative kinetic energy. It is found that the Sommerfeld parameter is suppressed due to the influence of collective nonideal shielding. However, the collective nonideal shielding is found to enhance the fusion penetration factor in partially ionized classical nonideal plasmas. It is also found that the fusion penetration factors in nonideal plasmas represented by the pseudopotential model are always greater than those in ideal plasmas represented by the Debye-Hückel model. In addition, it is shown that the collective nonideal shielding effect on the fusion penetration factor decreases with an increase of the kinetic energy.

  18. The role of chain carriers in fusion reaction kinetics

    International Nuclear Information System (INIS)

    Harms, A.A.; Krenciglowa, E.M.

    1980-01-01

    The role of chain carriers as contributors to multiplicative closed cycles in advanced fusion fuels is examined. Emphasis is placed on rate processes which can be used to characterize critical/supercritical/subcritical tendencies of arbitrary closed fusion cycles. Temporal trajectories for the chain carriers which describe both increasing and decreasing multiplicative processes have been found to exist and identified according to their fusion fuel cycle characteristics. Practical criteria to ensure the attainment of steady-state fusion reaction processes have been formulated in terms of fusion reaction rate relationships. (author)

  19. Cold fusion in symmetric 90Zr induced reactions

    International Nuclear Information System (INIS)

    Keller, J.G.

    1985-02-01

    At the velocity filter SHIP of the Society for Heavy Ion Research in Darmstadt cross sections for evaporation-residue-nucleus formation in the reactions 90 Zr+ 89 Y, sup(90,92,96)Zr, 94 Mo were measured. In four of the reactions leading to the compound nuclei 179 Au, 180 Hg, 182 Hg, and 184 Pb for the first time in reactions of two heavy partners with mass numbers >20 radiative capture, i.e. deexcitation only by emission of γ radiation, was observed. A comparison of the measured cross sections for radiative capture with evaporation calculations leads to the final conclusion that either the γ-strength in the different compound nuclei is very different, or that the energy or angular momentum dependence of the level-density is wrongly described by the Fermi gas model at energies between 5 and 20 MeV. From the cross sections for evaporation-residue-nucleus formation fusion probabilities for central collisions were derived. The fusion probabilities show a strong dependence of the sub-barrier fusion from the nuclear structure of the contributing reaction partners. The slope of the fusion probability below the classical fusion barrier cannot be consistently described even by newer models. Below the lowest fusion barrier the fusion probability decreases with decreasing energy remarkably faster that predicted by a WKB calculation. This indicates that either the shape of the barrier is different from that predicted by the potentials, or that the mass dependence of the tunnel effect is not correctly described by the WKB calculation. (orig.) [de

  20. How does the carbon fusion reaction happen in stars?

    International Nuclear Information System (INIS)

    Tang, X.; Bucher, B.; Fang, X.; Notani, M.; Tan, W.P.; Mooney, P.; Li, Y.; Esbensen, H.; Jiang, C.L.; Rehm, K.E.; Lin, C.J; Brown, E.

    2012-01-01

    The 12 C + 12 C fusion reaction is one of the most important reactions in the stellar evolution. Due to its complicated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of various stellar objects, such as massive stellar evolution, explosions on neutron stars, and supernovae from accreting white dwarf stars. In this paper, I will review the challenges in the study of carbon burning. I will also report recent results from our studies: 1) an upper limit for the 12 C + 12 C fusion cross sections, 2) measurement of the 12 C + 12 C at deep sub-barrier energies, and 3) a new measurement of the 12 C( 12 C, n) reaction. The outlook for the studies of the astrophysical heavy-ion fusion reactions will also be presented

  1. Fusion Reactions and Matter-Antimatter Annihilation for Space Propulsion

    Science.gov (United States)

    2005-07-13

    FUSION REACTIONS AND MATTER- ANTIMATTER ANNIHILATION FOR SPACE PROPULSION Claude DEUTSCH LPGP (UMR-CNRS 8578), Bât. 210, UPS, 91405 Orsay...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE šFusion Reactions And Matter- Antimatter Annihilation For Space Propulsion 5a...which is possible with successful MCF or ICF. Appropriate vessel designs will be presented for fusion as well as for antimatter propulsion. In

  2. Study of fusion reactions forming Cf nuclei

    International Nuclear Information System (INIS)

    Khuyagbaatar, J.; Hinde, D. J.; Du Rietz, R.; Carter, I. P.; Dasgupta, M.; Duellmann, C. E.; Evers, M.; Wakhle, A.; Williams, E.; Yakushev, A.

    2013-01-01

    The formation of a compound nucleus in different projectile and target combinations is a powerful method for investigating the fusion process. Recently, the dominance of quasi-fission over fusion-fission has been inferred for 34 S+ 208 Pb in comparison to 36 S+ 206 Pb; both reactions lead to the compound nucleus 242 Cf*.The mass and angle distributions of the fission fragments from these reactions were studied in order to further investigate the presence of quasi-fission. (authors)

  3. How does the carbon fusion reaction happen in stars?

    Directory of Open Access Journals (Sweden)

    X. Tang

    2013-09-01

    Full Text Available The 12C + 12C fusion reaction is one of the most important reactions in the stellar evolution. Due to its compli-cated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of vari-ous stellar objects, such as explosions on the surface of neutron stars, white dwarf (type Ia supernovae, and massive stellar evolution. In this paper, I will review the challenges in the study of carbon burning. I will also report recent re-sults from our studies: 1 an upper limit for the 12C + 12C fusion cross sections, 2 measurement of the 12C + 12C at deep sub-barrier energies, 3 a new measurement of the 12C(12C, n reaction. The outlook for the studies of the astrophysical heavy-ion fusion reactions will also be presented.

  4. Subsequent development of the normal temperature fusion reaction. Joon kakuyugo sonogo no shinten

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, T. (Hokkaido University, Sapporo (Japan). Faculty of Engineering)

    1991-04-24

    This paper reports on a NATTOH model made public in May 1989 by T. Matsumoto who took notice of abnormality of the normal temperature fusion reaction. The NATTO model is based on a chain reaction by hydrogen with a hydrogen-catalyzed fusion reaction which is the normal temperature fusion reaction as an elementary process. If a high temperature fusion reaction is a small-size simulation of the fusion reaction rising on the surface of the sparkling star like the sun, the normal temperature fusion reaction can be a small-size simulation of the phenomena in the last years of the star in the far distance of the space. This gives reality to the normal temperature fusion reaction. The reaction mechanism of the normal temperature fusion reaction is almost being clarified by a NATTOH model. There remain problems on a possibility of generation of unknown radioactive rays and identification of radioactive wastes, but it seems that a prospect of commercialization can be talked about now. As for the utilization as energy, sea water may be used as it is. 10 ref., 5 figs.

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

    Science.gov (United States)

    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.

  6. Neutron detector for fusion reaction-rate measurements

    International Nuclear Information System (INIS)

    Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

    1993-01-01

    We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response 7 neutrons

  7. Some thoughts on a simple mechanism for the 2H + 2H → 4He cold fusion reaction

    International Nuclear Information System (INIS)

    Park, A.E.

    1993-01-01

    A speculative mechanism for the creation of 4 He using cold fusion is proposed. The nuclear transformation can be made by the fusion of two excited rotating ground states of deuterium into a highly excited rotating ground state of 4 He. Under compression and relatively stable conditions, the formation of such a bound, stretched-out pnnp state of 4 He would be favored (with respect to Coulomb repulsion) over other nuclear ground states without as much angular momentum. The reaction likely occurs at the surface of palladium. A more descriptive name for this reaction is compressed-rotational-shielded (CRS) fusion. Potential experimental conditions for enhancing the initiation of CRS fusion are discussed. 8 refs., 2 figs

  8. Fusion dynamics of 2020Ne + 20882Pb reaction using static and energy dependent Woods-Saxon potential

    International Nuclear Information System (INIS)

    Gautam, Manjeet Singh; Kaur, Amandeep; Sharma, Manoj K.

    2015-01-01

    The present work compares the theoretical predictions based on static Woods-Saxon potential and the EDWSP model along with one dimensional Wong formula. For 20 20 Ne + 208 82 Pb reaction, the theoretical calculations obtained by using static Woods-Saxon potential are substantially smaller than that of experimental data at below barrier energies and explain the fusion data at above barrier energies only. On the other hand, the EDWSP model based calculations adequately describe the observed fusion enhancement of 20 20 Ne + 208 82 Pb reaction in whole range of energy spread across the Coulomb barrier. Furthermore, a wide range of the diffuseness parameter ranging from 0.96 fm to 0.85 fm is required to address the sub-barrier fusion data

  9. Enhanced pycnonuclear reactions in ultrahigh-pressure metals

    International Nuclear Information System (INIS)

    Ichimaru, Setsuo; Kitamura, Hikaru

    1995-01-01

    By combining the concepts of pycnonuclear reactions at low temperatures and their enhancement due to strong internuclear Coulomb correlations, we predict the possibilities of a novel scheme for fusion in ultrahigh-pressure liquid-metallic hydrogen near the freezing conditions, for the reactions 2 H(p,γ) 3 He, 3 H(d,n) 4 He, and 7 Li(p,α) 4 He. Time evolution is followed for p-d reaction after a pulsed compression with 1 kJ input and the initial conditions of mass density ≅ 20 g/cm 3 , temperature ≅ 1400 K, pressure ≅ 490 Mbar, and radius ≅ 0.017 cm; an energy yield of 33 kJ in 0.03 fs is thus predicted. (author)

  10. Influence of hexadecapole deformations of the nuclear shape of subbarrier fusion reactions

    International Nuclear Information System (INIS)

    Fernandez Niello, J.

    1989-01-01

    A systematic study of the contribution of hexadecapole deformations to the enhancement of subbarrier fusion cross reactions is carried out. The analysis is based on calculations that cover the full range of values of hexadecapole deformations found in actual nuclear systems. The interplay of this shape degree of freedom with the presence of prolate quadrupole deformations is also contemplated. (Author) [es

  11. Selected aspects of fusion reactions

    International Nuclear Information System (INIS)

    Lacroix, D.

    2003-01-01

    In this lecture, we present selected aspects of nuclear fusion. The importance of the initial geometry of the reaction and its relation to fusion barrier are first discussed. The effect of deformation leading to the notion of barrier distribution is then illustrated. After a brief overview of the advantages of macroscopic theories, the dynamics of nuclear system under large amplitude motion is reviewed. The di-nuclear concept is presented to understand the competition between fusion and quasi-fission. This concept is then generalized to account for the dissipative dynamics in multidimensional collective space. The last part of this lecture is devoted to new aspects encountered with radioactive beams specific properties of very extended neutron rich system, influence of pygmy or soft dipole resonances and charge exchange far from stability are discussed. (author)

  12. Quantum shielding effects on the Gamow penetration factor for nuclear fusion reaction in quantum plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-01-01

    The quantum shielding effects on the nuclear fusion reaction process are investigated in quantum plasmas. The closed expression of the classical turning point for the Gamow penetration factor in quantum plasmas is obtained by the Lambert W-function. The closed expressions of the Gamow penetration factor and the cross section for the nuclear fusion reaction in quantum plasmas are obtained as functions of the plasmon energy and the relative kinetic energy by using the effective interaction potential with the WKB analysis. It is shown that the influence of quantum screening suppresses the Sommerfeld reaction factor. It is also shown that the Gamow penetration factor increases with an increase of the plasmon energy. It is also shown that the quantum shielding effect enhances the deuterium formation by the proton-proton reaction in quantum plasmas. In addition, it is found that the energy dependences on the reaction cross section and the Gamow penetration factor are more significant in high plasmon-energy domains.

  13. Fusion reaction product diagnostics in ASDEX

    International Nuclear Information System (INIS)

    Bosch, H.S.

    1987-01-01

    A diagnostic method was developed to look for the charged fusion products from the D(D,p)T-reactions in the divertor tokamak ASDEX. With a semi-conductor detector it was possible to evaluate the ion temperature in thermal plasmas from the proton energy spectra as well as from the triton spectra. In lower-hybrid wave heated plasmas non-thermal (fast) ions were observed. These ions create fusion products with a characteristically different energy spectrum. (orig.)

  14. Effects of breakup of weakly bound projectile and neutron transfer on fusion reactions around Coulomb barrier

    International Nuclear Information System (INIS)

    Lin, C.J.; Zhang, H.Q.; Yang, F.; Ruan, M.; Liu, Z.H.; Wu, Y.W.; Wu, X.K.; Zhou, P.; Zhang, C.L.; Zhang, G.L.; An, G.P.; Jia, H.M.; Xu, X.X.

    2007-01-01

    The excitation functions of quasielastic and elastic scattering at backward angles have been measured for the systems of 16 O+ 152 Sm, 6,7 Li+ 208 Pb and 32 S+ 90,96 Zr. The barrier distributions are extracted from these measured excitation functions and compared with the corresponding fusion barrier distributions. Except some details, the barrier distributions derived from the data of fusion and quasielastic/elastic scattering are almost the same for the tightly bound reaction systems. For the reaction systems with weakly bound projectile, the barrier distributions extracted from quasielastic scattering are obviously different from the fusion barrier distributions. However, the barrier distributions extracted from the excitation functions of the quasielastic scattering plus breakup are almost the same as the one extracted from the complete fusion data. This result means that barrier distribution not only bears the information of nuclear structures but also contains the knowledge of reaction mechanisms. Our results show that the complete fusion of the weakly bound projectile with heavy target is suppressed at the above barrier energies as compared with the model predictions. In addition, the measured barrier distribution of 32 S+ 96 Zr is broaden and extends to lower energy than in the case of 32 S+ 90 Zr due to the coupling of neutron transfer with positive Q-values, which result in a significant enhancement of fusion cross sections at the subbarrier energies

  15. Effects of reaction channels in subbarrier fusion reactions

    International Nuclear Information System (INIS)

    Dasso, C.H.

    1984-01-01

    In this lecture we consider some aspects of fusion reactions between heavy ions at bombarding energies which are below or close to that of the Coulomb barrier. This problem has been traditionally confronted with simple barrier penetration calculations. So we start with a very brief review of what we can call the ''conventional'' procedure. (orig.)

  16. Screening effects on 12C+12C fusion reaction

    Science.gov (United States)

    Koyuncu, F.; Soylu, A.

    2018-05-01

    One of the important reactions for nucleosynthesis in the carbon burning phase in high-mass stars is the 12C+12C fusion reaction. In this study, we investigate the influences of the nuclear potentials and screening effect on astrophysically interesting 12C+12C fusion reaction observables at sub-barrier energies by using the microscopic α–α double folding cluster (DFC) potential and the proximity potential. In order to model the screening effects on the experimental data, a more general exponential cosine screened Coulomb (MGECSC) potential including Debye and quantum plasma cases has been considered in the calculations for the 12C+12C fusion reaction. In the calculations of the reaction observables, the semi-classical Wentzel-Kramers-Brillouin (WKB) approach and coupled channel (CC) formalism have been used. Moreover, in order to investigate how the potentials between 12C nuclei produce molecular cluster states of 24Mg, the normalized resonant energy states of 24Mg cluster bands have been calculated for the DFC potential. By analyzing the results produced from the fusion of 12C+12C, it is found that taking into account the screening effects in terms of MGECSC is important for explaining the 12C+12C fusion data, and the microscopic DFC potential is better than the proximity potential in explaining the experimental data, also considering that clustering is dominant for the structure of the 24Mg nucleus. Supported by the Turkish Science and Research Council (TÜBİTAK) with (117R015)

  17. A view on reactions of complete fusion

    International Nuclear Information System (INIS)

    Delchev, I.I.; Petkov, I.J.

    1978-11-01

    Complete fusion reactions are analysed within the framework of a theoretical model. Energy density interaction potentials are made use of and are renormalized for the purpose. A large number of heavy ion reactions are studied and the calculated critical angular moments are compared with experimental data

  18. Design of a fusion reaction-history measurement system with high temporal resolution

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Liu Shenye; Jiang Xiaohua; Tang Qi

    2010-01-01

    In order to accurately measure the history of fusion reaction for experimental study of inertial confinement fusion, we advance the design of a fusion reaction-history measurement system with high temporal resolution. The diagnostic system is composed of plastic scintillator and nose cone, an optical imaging system and the system of optic streak camera. Analyzing the capability of the system indicated that the instrument measured fusion reaction history at temporal resolution as low as 55ps and 40ps correspond to 2.45MeV DD neutrons and 14.03MeV DT neutrons. The instrument is able to measure the fusion reaction history at yields 1.5 x 10 9 DD neutrons, about 4 x 10 8 DT neutrons are required for a similar quality signal. (authors)

  19. Recent developments in heavy-ion fusion reactions around the Coulomb barrier

    Directory of Open Access Journals (Sweden)

    Hagino K.

    2016-01-01

    Full Text Available The nuclear fusion is a reaction to form a compound nucleus. It plays an important role in several circumstances in nuclear physics as well as in nuclear astrophysics, such as synthesis of superheavy elements and nucleosynthesis in stars. Here we discuss two recent theoretical developments in heavy-ion fusion reactions at energies around the Coulomb barrier. The first topic is a generalization of the Wong formula for fusion cross sections in a single-channel problem. By introducing an energy dependence to the barrier parameters, we show that the generalized formula leads to results practically indistinguishable from a full quantal calculation, even for light symmetric systems such as 12C+12C, for which fusion cross sections show an oscillatory behavior. We then discuss a semi-microscopic modeling of heavy-ion fusion reactions, which combine the coupled-channels approach to the state-of-the-art nuclear structure calculations for low-lying collective motions. We apply this method to subbarrier fusion reactions of 58Ni+58Ni and 40Ca+58Ni systems, and discuss the role of anharmonicity of the low-lying vibrational motions.

  20. Microscopic study on dynamic barrier in fusion reactions

    International Nuclear Information System (INIS)

    Wu Xizhen; Tian Junlong; Zhao Kai; Li Zhuxia; Wang Ning

    2004-01-01

    The authors briefly review the fusion process of very heavy nuclear systems and some theoretical models. The authors propose a microscopic transport dynamic model, i.e. the Improved Quantum Molecular Dynamic model, for describing fusion reactions of heavy systems, in which the dynamical behavior of the fusion barrier in heavy fusion systems has been studied firstly. The authors find that with the incident energy decreasing the lowest dynamic barrier is obtained which approaches to the adiabatic static barrier and with increase of the incident energy the dynamic barrier goes up to the diabatic static barrier. The authors also indicate that how the dynamical fusion barrier is correlated with the development of the configuration of fusion partners along the fusion path. Associating the single-particle potentials obtained at different stages of fusion with the Two Center Shell Model, authors can study the time evolution of the single particle states of fusion system in configuration space of single particle orbits along the fusion path. (author)

  1. SU-F-T-140: Assessment of the Proton Boron Fusion Reaction for Practical Radiation Therapy Applications Using MCNP6

    Energy Technology Data Exchange (ETDEWEB)

    Adam, D; Bednarz, B [University of Wisconsin, Madison, WI (United States)

    2016-06-15

    Purpose: The proton boron fusion reaction is a reaction that describes the creation of three alpha particles as the result of the interaction of a proton incident upon a 11B target. Theoretically, the proton boron fusion reaction is a desirable reaction for radiation therapy applications in that, with the appropriate boron delivery agent, it could potentially combine the localized dose delivery protons exhibit (Bragg peak) and the local deposition of high LET alpha particles in cancerous sites. Previous efforts have shown significant dose enhancement using the proton boron fusion reaction; the overarching purpose of this work is an attempt to validate previous Monte Carlo results of the proton boron fusion reaction. Methods: The proton boron fusion reaction, 11B(p, 3α), is investigated using MCNP6 to assess the viability for potential use in radiation therapy. Simple simulations of a proton pencil beam incident upon both a water phantom and a water phantom with an axial region containing 100ppm boron were modeled using MCNP6 in order to determine the extent of the impact boron had upon the calculated energy deposition. Results: The maximum dose increase calculated was 0.026% for the incident 250 MeV proton beam scenario. The MCNP simulations performed demonstrated that the proton boron fusion reaction rate at clinically relevant boron concentrations was too small in order to have any measurable impact on the absorbed dose. Conclusion: For all MCNP6 simulations conducted, the increase of absorbed dose of a simple water phantom due to the 11B(p, 3α) reaction was found to be inconsequential. In addition, it was determined that there are no good evaluations of the 11B(p, 3α) reaction for use in MCNPX/6 and further work should be conducted in cross section evaluations in order to definitively evaluate the feasibility of the proton boron fusion reaction for use in radiation therapy applications.

  2. Quasi-elastic scattering an alternative tool for mapping the fusion barriers for heavy-ion induced fusion reaction

    International Nuclear Information System (INIS)

    Behera, B.R.

    2016-01-01

    Heavy element synthesis through heavy-ion induced fusion reaction is an active field in contemporary nuclear physics. Exact knowledge of fusion barrier is one of the essential parameters for planning any experiments for heavy element production. Theoretically there are many models available to predict the exact barrier. Though these models are successful for predicting the fusion of medium mass nuclei, it somehow fails for predicting the exact location of barrier for fusion of heavy nuclei. Experimental determination of barrier for such reactions is required for future experiments for the synthesis of heavy elements. Traditionally fusion barrier is determined taking a double derivative of fusion excitation function. However, such method is difficult in case of fusion of heavy nuclei due to its very low fusion/capture cross section and its experimental complications. Alternatively fusion barrier can be determined by measuring the quasi-elastic cross section at backward angles. This method can be applied for determining the fusion barrier for the fusion of heavy nuclei. Experimental determination of fusion barrier by different methods and comparison of the fusion excitation function and quasi-elastic scattering methods for the determination of fusion barrier are reviewed. At IUAC, New Delhi recently a program has been started for the measurement of fusion barrier through quasi-elastic scattering methods. The experimental facility and the first results of the experiments carried out with this facility are presented. (author)

  3. Fusion dynamics in 40Ca induced reactions

    International Nuclear Information System (INIS)

    Prasad, E.; Hinde, D.J.; Williams, E.

    2017-01-01

    Synthesis of superheavy elements (SHEs) and investigation of their properties are among the most challenging research topics in modern science. A non-compound nuclear process called quasi fission is partly responsible for the very low production cross sections of SHEs. The formation and survival probabilities of the compound nucleus (CN) strongly depend on the competition between fusion and quasi fission. A clear understanding of these processes and their dynamics is required to make reliable predictions of the best reactions to synthesise new SHEs. All elements beyond Nh are produced using hot fusion reactions and beams of 48 Ca were used in most of these experiments. In this context a series of fission measurements have been carried out at the Australian National University (ANU) using 40;48 Ca beams on various targets ranging from 142 Nd to 249 Cf. Some of the 40 Ca reactions will be discussed in this symposium

  4. Recent developments in fusion and direct reactions with weakly bound nuclei

    International Nuclear Information System (INIS)

    Canto, L.F.; Gomes, P.R.S.; Donangelo, R.; Lubian, J.; Hussein, M.S.

    2015-01-01

    In this Report we give a balanced account of the experimental and theoretical advances acquired over the last decade in the field of near-barrier fusion reactions induced by weakly bound stable and unstable nuclei. The elastic scattering and breakup reactions of these systems are also extensively reviewed as they play an important role in the fusion process. We review several theoretical tools used in the description of the data. The concepts of Complete Fusion (CF), Incomplete Fusion (ICF) and Total Fusion (TF), which is the sum of CF and ICF, are discussed and recent work on the calculation of these quantities is reviewed. The Continuum Discretized Coupled Channels (CDCC) method and its semiclassical version are described in detail and their limitations are pointed out. More importantly, we describe the salient features of the conclusions reached from the more than 40 measurements made, over a decade, of near-barrier fusion, elastic scattering and breakup reactions, and confront these data with the CDCC or other methods appropriate for these processes at the energy regime in question.

  5. Enhancing the muon-catalyzed fusion yield

    International Nuclear Information System (INIS)

    Jones, S.E.

    1987-01-01

    Much has been learned about muon-catalyzed fusion since the last conference on emerging nuclear energy systems. Here the authors consider what they have learned about enhancing the muon-catalyzed fusion energy yield

  6. Effect of projectile structure on evaporation residue yields in incomplete fusion reactions

    CERN Document Server

    Babu, K S; Sudarshan, K; Shrivastava, B D; Goswami, A; Tomar, B S

    2003-01-01

    The excitation functions of heavy residues, representing complete and incomplete fusion products, produced in the reaction of sup 1 sup 2 C and sup 1 sup 3 C on sup 1 sup 8 sup 1 Ta have been measured over the projectile energy range of 5 to 6.5 MeV/nucleon by the recoil catcher method and off-line gamma-ray spectrometry. Comparison of the measured excitation functions with those calculated using the PACE2 code based on the statistical model revealed the occurrence of incomplete fusion reactions in the formation of alpha emission products. The fraction of incomplete fusion cross sections in the sup 1 sup 2 C + sup 1 sup 8 sup 1 Ta reaction was found to be higher, by a factor of approx 2, than that in the sup 1 sup 3 C + sup 1 sup 8 sup 1 Ta reaction. The results have been discussed in terms of the effect of alpha cluster structure of the projectile on incomplete fusion reactions.

  7. Plasma fluctuations and confinement of fusion reaction products

    International Nuclear Information System (INIS)

    Coppi, B.; Pegoraro, F.

    1981-01-01

    The interaction between the fluctuations that can be excited in a magnetically confined plasma and the high-energy-particle population produced by fusion reactions is analyzed in view of its relevance to the process of thermonuclear ignition. The spectrum of the perturbations that, in the absence of fusion reaction products, would be described by the incompressible ideal magnetohydrodynamic approximation is studied considering finite value of the plasma pressure relative ot the magnetic pressure. The combined effects of the magnetic field curvature and shear are taken into account and the relevant spectrum is shown to consist of a continuous portion, that could be identified as a mixture of shear-Alfven and interchange oscillations, and a discrete unstable part corresponding to the so-called ballooning modes. The rate of diffusion of the fusion reaction products induced by oscillations in the continuous part of the spectrum, as estimated from the appropriate quasi-linear theory, is found to be significantly smaller than could be expected if normal modes (i.e., nonconvective solutions) were excited. However, a relatively wide intermediate region is identified where opalescent fluctuations, capable of achieving significant amplitudes and corresponding to a quasi-discrete spectrum, can be excited

  8. Fusion reaction around the Coulomb barrier with neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Atsushi [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1997-07-01

    Two fusion reactions with neutron-rich nuclei are reported in this work. On the first reaction: {sup 9,10,11}Be+{sup 209}Bi, the fusion cross sections around the coulomb barrier were measured by determing {alpha} disintegration from compound nucleus Fr. In the field of 10-100 mb, the same total fusion cross sections were obtained. The phenomenon {sup 11}Be(neutron halo nucleus) alone increased and decreased was not observed. The fusion cross sections of {sup 27,29,31}Al+{sup 197}Au system were determined by using 130 kcps and 30 kcps of beam strength of {sup 29,31}Al, respectively. The value of {sup 27}Al was reproduced by calculation, but that of {sup 29}Al increased around barrier which could not be explained by CCDEF calculation. (S.Y.)

  9. Many-body treatment of subbarrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Akira; Kondratyev, V. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Bonasera, A.

    1998-07-01

    The subbarrier fusion of heavy-ions at energies around the Coulomb barrier is studied by using semiclassical mean-field theory. The paths connecting entrance and exit subbarrier fusion reaction channels are found by incorporating the Wick transformation into the mean-field kinetic equation. The polarization and deformation of nuclei is shown to lower the barrier height. It is demonstrated that preequilibrium nucleon exchange in classically forbidden region gives rise to the nonlocal effects lowering the effective barrier further at small relative distance. (author)

  10. Fusion barrier distributions in 28,30Si + 124Sn reactions

    International Nuclear Information System (INIS)

    Danu, L.S.; Nayak, B.K.; Biswas, D.C.; Saxena, A.; Thomas, R.G.; Mirgule, E.T.; Choudhury, R.K.

    2009-01-01

    The coupling of various degrees of freedom such as static deformation, inelastic excitation and nucleon transfer with the relative motion gives rise to a distribution of barrier in heavy ion induced fusion reactions. The barrier distribution is a fingerprint of the reaction characterizing the important channel couplings. The relative importance of various couplings in fusion reaction is of topical interest. In an earlier study with deformed projectiles 28,30 Si on 115 In target, it was observed that the barrier distributions get affected due to coulomb reorientation of the deformed projectile nuclei in the field of target nucleus thus giving rise to fusion hindrance at sub-barrier energies. In that study, we considered deformed projectile rotational and positive Q-value transfer channel couplings to relative motion in fusion for investigation of Coulomb reorientation and no inelastic coupling of the 115 In target was considered. In the present work, we have extended the measurements with 124 Sn target and inelastic coupling of target has been considered in the coupled channel calculations. The fusion barrier distributions for 28,30 Si + 124 Sn systems have been obtained by quasi-elastic scattering measurements at backward angles and the results compared with the predictions of coupled channel calculations

  11. Recent results on fusion and direct reactions with weakly bound stable nuclei

    International Nuclear Information System (INIS)

    Shrivastava, A.

    2011-01-01

    Recent measurements of fusion and direct reactions in case of weakly bound stable nuclei at extreme sub-barrier energies using a sensitive off beam technique are presented. First section deals with deep sub-barrier fusion cross-section measurement for 67 Li + 198 Pt followed by the study of fragment capture reaction of 7 Li + 198 Pt. Deviation in the slope of the fusion excitation function, as observed in case of medium heavy systems, is absent in the present asymmetric systems at these low energies. This study shows the absence of fusion hindrance, suggesting modifications in models that explain deep sub-barrier fusion data to incorporate weakly bound asymmetric systems

  12. Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility

    International Nuclear Information System (INIS)

    Wang Feng; Peng Xiao-Shi; Liu Shen-Ye; Xu Tao; Kang Dong-Guo

    2013-01-01

    A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of ∼ 30 ps at the Shen Guang-III (SG-III) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion

  13. Semi empirical model for astrophysical nuclear fusion reactions of 1≤Z≤15

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Seenappa, L.; Sridhar, K.N.

    2017-01-01

    The fusion reaction is one of the most important reactions in the stellar evolution. Due to the complicated reaction mechanism of fusion, there is great uncertainty in the reaction rate which limits our understanding of various stellar objects. Low z elements are formed through many fusion reactions such as "4He+"1"2C→"1"6O, "1"2C+"1"2C→"2"0Ne+"4He, "1"2C+"1"2C→"2"3Na, "1"2C+"1"2C→"2"3Mg, "1"6O+"1"6O→"2"8Si+"4He, "1"2C+"1H→"1"3N and "1"3C+"4He→"1"6O. A detail study is required on Coulomb and nuclear interaction in formation of low Z elements in stars through fusion reactions. For astrophysics, the important energy range extends from 1 MeV to 3 MeV in the center of mass frame, which is only partially covered by experiments. In the present work, we have studied the basic fusion parameters such as barrier heights (V_B), positions (R_B), curvature of the inverted parabola (ħω_1) for fusion barrier, cross section and compound nucleus formation probability (P_C_N) and fusion process in the low Z element (1≤Z≤15) formation process. For each isotope, we have studied all possible projectile-target combinations. We have also studied the astrophysical S(E) factor for these reactions. Based on this study, we have formulated the semi empirical relations for barrier heights (V_B), positions (R_B), curvature of the inverted parabola and hence for the fusion cross section and astrophysical S(E) factor. The values produced by the present model compared with the experiments and data available in the literature. (author)

  14. Incomplete fusion studies

    International Nuclear Information System (INIS)

    Singh, B.P.

    2011-01-01

    In order to study the incomplete fusion reaction dynamics at energies ≅ 4-7 MeV/nucleon, several experiments have been carried out using accelerator facilities available in India. The measurements presented here cover a wide range of projectile-target combinations and enhance significantly our knowledge about incomplete fusion reaction dynamics. Here, the three sets of measurements have been presented; (i) excitation functions, (ii) forward recoil range distributions and (iii) the spin distributions. The first evidence of these reactions has been obtained from the measurement and analysis of excitation functions for xn/αxn/2αxn-channels. The measured excitation functions have been analyzed within the framework of compound nucleus model. The results obtained indicate the occurrence of fusion incompleteness at low beam energies. However, in order to determine the relative contribution of complete and incomplete fusion reaction processes, the recoil range distributions of the heavy residues have also been measured and analyzed within the framework of breakup fusion model which confirmed the fusion incompleteness in several heavy ion reactions involving α-emitting reaction channels. Further, in order to study the role of l-values in these reactions the spin distributions of the residues populated in case of complete and incomplete channels have been measured and are found to be distinctly different. The analysis of the data on spin distribution measurements indicate that the mean values of driving input angular momenta associated with direct-α-emitting (incomplete fusion) channels are higher than that observed for fusion-evaporation xn or α-emitting (complete fusion) channels, and is found to increase with direct α-multiplicity in the forward cone. One of the important conclusions drawn in the present work is that, there is significant incomplete fusion contribution even at energies slightly above the barrier. Further, the projectile structure has been found to

  15. Competition between fusion and quasi-fission in heavy ion induced reactions

    International Nuclear Information System (INIS)

    Back, B.B.

    1986-09-01

    Quantitative analyses of angular distributions and angle-mass correlations have been applied to the U + Ca reaction to obtain upper limit estimates for the cross sections for complete fusion near or below the interaction barrier. Extrapolating to the systems Ca + Cm and Ca + Es using the well established scaling properties of the extra push model, an estimate of the cross sections relevant to the efforts of synthesizing super-heavy elements in the region Z = 116 and N = 184 via heavy-ion fusion reactions are obtained. A simple evaporation calculation using properties of the super heavy elements shows that the failure to observe super-heavy elements with the Ca + Cm reaction is consistent with estimates of the complete fusion process. 33 refs., 9 figs., 1 tab

  16. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    International Nuclear Information System (INIS)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang; Liu, Yan-Hong; Li, Yan; Wang, Jia-Ye; Hattori, Toshio; Ling, Hong; Zhang, Feng-Min

    2010-01-01

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  17. Cold fusion in symmetric 90Zr induced reactions

    International Nuclear Information System (INIS)

    Keller, J.G.; Schmidt, K.H.; Hessberger, F.P.; Muenzenberg, G.; Reisdorf, W.; Clerc, H.G.; Sahm, C.C.

    1985-08-01

    Excitation functions for evaporation residues were measured for the reactions 90 Zr+ 89 Y, 90 Zr, 92 Zr, 96 Zr, and 94 Mo. Deexcitation only by γ radiation was found for the compound nuclei 179 Au, 180 Hg, 182 Hg, and 184 Pb. The cross sections for this process were found to be considerably larger than predicted by a statistical-model calculation using standard parameters for the γ-strength function. Fusion probabilities as well as fusion-barrier distributions were deduced from the measured cross sections. There are strong nuclear structure effects in subbarrier fusion. For energies far below the fusion barrier the increase of the fusion probabilities with increasing energy is found to be much steeper than predicted by WKB calculations. As a by-product of this work new α-spectroscopic information could be obtained for neutron deficient isotopes between Ir and Pb. (orig.)

  18. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    International Nuclear Information System (INIS)

    Labaune, C.; Baccou, C.; Loisel, G.; Yahia, V.; Depierreux, S.; Goyon, C.; Rafelski, J.

    2013-01-01

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. (authors)

  19. Hyperenhanced Li - Li Chemonuclear Fusion

    International Nuclear Information System (INIS)

    Ikegami, Hidetsugu

    2006-01-01

    A new fusion scheme, the Li - Li chemonuclear fusion is presented, where nuclear fusion reactions are linked to atomic fusion reactions. Lithium ions are implanted on a surface of metallic Li liquid at an energy of nuclear stopping (several keV/amu). The ions collide slowly with liquid Li atoms without electronic excitation and lead to the Li - Li chemonuclear fusion through the formation of united atoms or quasi-C atoms at their turning points. Inside the quasi-atoms twin nuclei are confined within respective sub-pm scale spheres of zero-point oscillation and form themselves into ultradense intermediate nuclear complexes. Their density is million times as large as the solar interior density and close to densities of white dwarfs or white-dwarf progenitors of supernovae. This confinement of nuclear complexes is enormously prolonged towards the pycno-nuclear reactions induced by the zero-point oscillation under the presence of thermodynamic force specified by the Gibbs energy change in the quasi-atom formation in the liquid. Resulted rate enhancement of nuclear fusion by a factor of 10 48 has been anticipated. The enhancement is also argued in connection with the Bose-Einstein condensation

  20. Effect of projectile on incomplete fusion reactions at low energies

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2017-01-01

    Full Text Available Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n excess projectile 13C (as compared to 12C results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B and forward (F α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  1. Effect of projectile on incomplete fusion reactions at low energies

    Science.gov (United States)

    Sharma, Vijay R.; Shuaib, Mohd.; Yadav, Abhishek; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Singh, Devendra P.; Singh, B. P.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.; Prasad, R.

    2017-11-01

    Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF) is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n) excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B) and forward (F) α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  2. Enhancement of deuteron-fusion reactions in metals and experimental implications

    International Nuclear Information System (INIS)

    Huke, A.; Heide, P.; Czerski, K.; Ruprecht, G.; Targosz, N.; Zebrowski, W.

    2008-01-01

    Recent measurements of the reaction 2 H(d,p) 3 H in metallic environments at very low energies performed by different experimental groups point to an enhanced electron screening effect. However, the resulting screening energies differ strongly for diverse host metals and different experiments. Here, we present new experimental results and investigations of interfering processes in the irradiated targets. These measurements inside metals set special challenges and pitfalls that make them and the data analysis particularly error prone. There are multiparameter collateral effects that are crucial for the correct interpretation of the observed experimental yields. They mainly originate from target surface contaminations owing to residual gases in the vacuum as well as from inhomogeneities and instabilities in the deuteron density distribution in the targets. To address these problems an improved differential analysis method beyond the standard procedures has been implemented. Profound scrutiny of the other experiments demonstrates that the observed unusual changes in the reaction yields are mainly due to deuteron density dynamics simulating the alleged screening energy values. The experimental results are compared with different theoretical models of the electron screening in metals. The Debye-Hueckel model that has been previously proposed to explain the influence of the electron screening on both nuclear reactions and radioactive decays can be clearly excluded

  3. Neutron-induced reactions relevant for Inertial-Cofinement Fusion Experiments

    Science.gov (United States)

    Boswell, Melissa; Devlin, Mathew; Fotiadis, Nikolaos; Merrill, Frank; Nelson, Ronald; Tonchev, Anton

    2014-09-01

    The typical ignition experiment at the National Ignition Facility ablatively implodes a plastic capsule filled with DT fuel, generating a high flux of 14-MeV neutrons from the d(t,n) α reaction. There is some spread in the energy of these primary 14-MeV neutrons, which is mainly attributable to Doppler shifting from the relative thermal motion of the burning DT fuel. Neutrons created during this reaction have 5--10% chance of scattering before escaping the fuel assembly, losing some fraction of their energy in the scattering process. Neutrons emerging with an energy greater than the reaction energy are generated by a two-step process where neutrons first transfer momentum to a deuteron or tritium ion, these enhanced energy ions then fuse in flight to produce higher energy neutrons; some of these neutrons have energies in excess of 30 MeV. Measuring the fluencies of both the low- and high-energy neutrons is a powerful mechanism for studying the properties of the fuel assembly, and the various parameters important to inertial confinement fusion. We have developed a number of tools to measure the spectral characteristics of the NIF neutron spectrum. Most of these methods rely on exploiting the energy dependence of (n, γ), (n,2n), (n,3n) and (n,p) reactions on a variety o.

  4. Classical simulations of heavy-ion fusion reactions and weakly ...

    Indian Academy of Sciences (India)

    82, No. 5. — journal of. May 2014 physics pp. 879–891. Classical simulations of heavy-ion fusion reactions and weakly-bound projectile breakup reactions ... on the collision energy and the moment of inertia of the deformed nucleus. ... where each individual nucleus consists of a number of protons and neutrons, in some.

  5. Process and device for energy production from thermonuclear fusion reactions

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, Bruno.

    1977-01-01

    An energy generating system is described using a fusion reaction. It includes several contrivances for confining a plasma in an area, a protective device around a significant part of each of these confinement contrivances, an appliance for introducing a fusion reaction fuel in each of the confinements so that the plasma may be formed. Each confinement can be separated from the protective device so that it may be replaced by another. The system is connected to the confinements, to the protective devices or to both. It enables the thermal energy to be extracted and transformed into another form, electric, mechanical or both [fr

  6. Study of incomplete fusion reaction dynamics in 13C +165 Ho system and its dependence on various entrance channel parameters

    Science.gov (United States)

    Tali, Suhail A.; Kumar, Harish; Ansari, M. Afzal; Ali, Asif; Singh, D.; Ali, Rahbar; Giri, Pankaj K.; Linda, Sneha B.; Parashari, Siddharth; Kumar, R.; Singh, R. P.; Muralithar, S.

    2018-02-01

    The excitation functions for the evaporation residues populated in the interaction of 13C +165 Ho system have been measured at projectile energies ≈ 4-7 MeV/nucleon. Stacked foil activation technique followed by off-line γ-ray spectroscopy have been employed in the present work. The experimentally measured cross-sections are analyzed in the frame work of statistical model code PACE4, which takes into account only the complete fusion reaction cross-sections. The evaporation residues populated via xn and pxn channels were found to be in good agreement with the PACE4 predictions, while a significant enhancement in the measured cross-sections over PACE4 predictions is observed in case of α-emitting channels, which may be attributed to the incomplete fusion process. For the better understanding of incomplete fusion dynamics, the incomplete fusion fraction has also been deduced and its sensitivity with various entrance channel parameters like: projectile energy, mass-asymmetry, projectile structure in terms of Qα-value and Coulomb effect has been studied in the present work. The incomplete fusion fraction is found to increase with increasing the projectile energy and a strong projectile structure dependent mass-asymmetry systematic is also observed. The incomplete fusion fraction is also found to be small for more negative Qα-value projectile (13C) induced reactions as compared to less negative Qα-value projectiles (12C, 16O and 20Ne) induced reactions with the same target nucleus 165Ho. An interesting trend is obtained on further investigation of incomplete fusion dependence on Coulomb effect (ZPZT).

  7. The influence of transfer reactions on the sub-barrier fusion enhancement in the systems {sup 58.64}Ni +, {sup 92,100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

    1995-08-01

    High resolution experiments performed during the past few years demonstrated that the various reaction modes occurring in heavy ion collisions can strongly influence each other. This interrelation of the different reaction modes brings a nuclear structure dependence to the fusion and deep-inelastic channels that were previously described in the framework of pure statistical models. In order to fully understand the interrelation between these reaction channels, a complete set of measurements including elastic and inelastic scattering, few-nucleon transfer and fusion is required. In continuation of our earlier measurements of the fusion cross sections in the system {sup 58,64}Ni + {sup 92,100}Mo we finished the studies of the quasielastic process in these systems. The experiments were done in inverse reaction kinematics using the split-pole spectrograph with its hybrid focal-plane detector for particle identification. The experiments with {sup 100}Mo beams were performed previously. First test runs with {sup 92}Mo showed the possible interference with {sup 98}Mo ions which could be eliminated by using the 13{sup +} charge state from the ECR source. The data from these experiments were completely analyzed. The smallest transfer cross sections are observed for the systems {sup 64}Ni + {sup 100}Mo and {sup 58}Ni + {sup 92}Mo, i.e., the most neutron-rich and neutron-deficient systems, respectively. For the other systems, {sup 64}Ni + {sup 92}Mo and {sup 58}Ni + {sup 100}Mo, the transfer cross sections at energies close to the barrier are about of equal magnitude. This observation does not correlate with the deviation of the experimental fusion cross sections from the coupled-channels predictions. While for {sup 58}Ni + {sup 100}Mo discrepancies between the experimental and theoretical fusion cross sections are observed, the system {sup 64}Ni + {sup 92}Mo which shows about the same transfer yields, is quite well described by the coupled-channels calculations.

  8. Stochastic semi-classical description of sub-barrier fusion reactions

    Directory of Open Access Journals (Sweden)

    Ayik Sakir

    2011-10-01

    Full Text Available A semi-classical method that incorporates the quantum effects of the low-lying vibrational modes is applied to fusion reactions. The quantum effect is simulated by stochastic sampling of initial zero-point fluctuations of the surface modes. In this model, dissipation of the relative energy into non-collective excitations of nuclei can be included straightforwardly. The inclusion of dissipation is shown to increase the agreement with the fusion cross section data of Ni isotopes.

  9. Potential design modifications for the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber

    International Nuclear Information System (INIS)

    Pitts, J.H.; Hovingh, J.; Meier, W.R.; Monsler, M.J.; Powell, E.G.; Walker, P.E.

    1979-01-01

    Generation of electric power from inertial confinement fusion requires a reaction chamber. One promising type, the High Yield Lithium Injection Fusion Energy (HYLIFE) chamber, includes a falling array of liquid lithium jets. These jets act as: (1) a renewable first wall and blanket to shield metal components from x-ray and neutron exposure, (2) a tritium breeder to replace tritium burned during the fusion process, and (3) an absorber and transfer medium for fusion energy. Over 90% of the energy produced in the reaction chamber is absorbed in the lithium jet fall. Design aspects are included

  10. Study of Cold Fusion Reactions Using Collective Clusterization Approach

    Science.gov (United States)

    Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

    2017-10-01

    Within the framework of the dynamical cluster decay model (DCM), the 1n evaporation cross-sections ({σ }1n) of cold fusion reactions (Pb and Bi targets) are calculated for {Z}{CN}=104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy {E}{CN}* =15+/- 1 {MeV}, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers (B f ) and neutron separation energies ({S}1n) are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β 2i-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile (t,p) combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the 1n cross-sections are addressed for {Z}{CN}=104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto {Z}{CN}=109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia ({I}{NS}) is also investigated at these energies. Supported by the Council of Scientific and Industrial Research (CSIR), in the Form of Research Project Grant No. 03(1341)/15/EMR-II, and to DST, New Delhi, for INSPIRE-Fellowship Grant No. DST/INSPIRE/03/2015/000199

  11. Fusion barrier distributions from capture and quasi-elastic excitation functions measured in reaction 36S, 48Ca, 64Ni+238U

    International Nuclear Information System (INIS)

    Kozulin, E. M.

    2009-01-01

    The subbarrier fusion enhancement in reactions with heavy ions were explained by taking into account coupling between relative motion and intrinsic degrees of freedom of interacting nuclei. The coupling of reaction channels manifests itself in the potential barrier between interacting nuclei giving rise to a distribution of fusion barrier instead of single barrier.Capture and quasi-elastic scattering excitation functions at backward angles were measured for 3 6S , 4 8C a, 6 4N i+2 38U reactions systems at energies close and below the Coulomb barrier (i.e. when the influence of the shell effects on the fusion and characteristics of the decay of the composite system is considerable). Representations of the barrier distributions were extracted from both capture and quasi-elastic data. The experimental representations of barrier distributions were compared with coupled-channel calculations using CCFULL code. The major part of these experiments has been performed at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Dubna); at the TANDEM-ALPI accelerator of the LNL (INFN, Legnaro, Italy) and at the Accelerator Laboratory of University of Jyvaeskylae (JYFL, Finland) using a time-of-flight spectrometer of fission fragments CORSET (CORrelation SET-up.) The extraction of the masses and Total Kinetic Energy (TKE) of the binary reaction products is based upon the analysis of the two-body velocity In the case of the fusion-fission and quasi-fission processes, the observed peculiarities of mass and energy distributions of the fragments, the ratio between the fusion-fission and quasi-fission cross sections are determined deformations of interaction nuclei and angular momentum carried in the di-nuclear system and the shell structure of the formed fragments. In this work, the high-precision capture and quasi-elastic scattering excitation function data are presented.The influence of projectile and target excitations and nucleon transfer on fusion barrier

  12. Constraining statistical-model parameters using fusion and spallation reactions

    Directory of Open Access Journals (Sweden)

    Charity Robert J.

    2011-10-01

    Full Text Available The de-excitation of compound nuclei has been successfully described for several decades by means of statistical models. However, such models involve a large number of free parameters and ingredients that are often underconstrained by experimental data. We show how the degeneracy of the model ingredients can be partially lifted by studying different entrance channels for de-excitation, which populate different regions of the parameter space of the compound nucleus. Fusion reactions, in particular, play an important role in this strategy because they fix three out of four of the compound-nucleus parameters (mass, charge and total excitation energy. The present work focuses on fission and intermediate-mass-fragment emission cross sections. We prove how equivalent parameter sets for fusion-fission reactions can be resolved using another entrance channel, namely spallation reactions. Intermediate-mass-fragment emission can be constrained in a similar way. An interpretation of the best-fit IMF barriers in terms of the Wigner energies of the nascent fragments is discussed.

  13. Incomplete fusion analysis of the 7Li-induced reaction on 93Nb within 3-6.5 MeV/nucleon

    Science.gov (United States)

    Kumar, Deepak; Maiti, Moumita

    2017-10-01

    Background: It is understood from the recent experimental studies that prompt/resonant breakup, and transfer followed by breakup in the weakly bound Li,76-induced reactions play a significant role in the complete-incomplete fusion (CF-ICF), suppression/enhancement in the fusion cross section around the Coulomb barrier. Purpose: Investigation of ICF over CF by measuring cross sections of the populated residues, produced via different channels in the 7Li-induced reaction on a natNb target within the 3-6.5 MeV/nucleon energy region. Method: The 7Li beam was allowed to hit the self-supporting 93Nb targets, backed by the aluminium (Al) foil alternately, within 3-6.5 MeV/nucleon energy. Populated residues were identified by offline γ -ray spectrometry. Measured excitation functions of different channels were compared with different equilibrium and pre-equilibrium models. Result: The enhancement in cross sections in the proton (˜20 -30 MeV) and α -emitting channels, which may be ascribed to ICF, was observed in the measured energy range when compared to the Hauser-Feshbach and exciton model calculations using empire, which satisfactorily reproduces the neutron channels, compared to the Weisskopf-Ewing model and hybrid Monte Carlo calculations. The increment of the incomplete fusion fraction was observed with rising projectile energy. Conclusion: Contrary to the alice14, experimental results are well reproduced by the empire throughout the measured energy range. The signature of ICF over CF indicates that the breakup/transfer processes are involved in the weakly bound 7Li-induced reaction on 93Nb slightly above the Coulomb barrier.

  14. Spectroscopic study of 126I via incomplete fusion reaction

    International Nuclear Information System (INIS)

    Kanagalekar, B.A.; Das, Pragya; Kumar, Vinod; Kumar, R.; Singh, R.P.; Muralithar, S.; Bhowmik, R.K.

    2006-01-01

    The experiment at Inter University Accelerator Centre consisted of identifying the yrast high-spin states of 126 I using the incomplete fusion reaction 124 Sn ( 10 B, α4n) 126 I at beam energy of 70 MeV

  15. Cross-sections and average angular momenta in fusion reactions near the coulomb barrier

    International Nuclear Information System (INIS)

    Dasgupta, M.

    1992-01-01

    In recent years there has been an increasing interest in the study of heavy ion collisions near the Coulomb barrier. This has been triggered mainly by the observations of enhancements by factors of about one to two order of magnitude in sub-Coulomb barrier fusion (SBF) cross-sections between medium mass nuclei, as compared to predictions based on one-dimensional barrier penetration model (l-d BPM). Though, a considerable amount of work both theoretical and experimental has been done in this field, a complete understanding of the SBF phenomenon has not yet been achieved. The relation between fusion excitation function and angular momentum (l) distribution in SBF reactions is a topic of current interest. It is believed that l-distributions provide a more stringent test of SBF models that the excitation functions alone. Simultaneous measurement of l-distribution (or its moments) and fusion excitation function is expected to lead to a better understanding of the relationship between these two qualities. Such information has been obtained in experiments done at pelletron accelerator facility. In the present talk the measurement of fusion cross-sections and the method of determination of average l from partial evaporation residue cross-section has been elaborated. An analysis of the experimental data on the basis of some of the SBF models has been discussed briefly. (author). 13 refs

  16. Roles of multi-step transfer in fusion process induced by heavy-ion reactions

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1993-06-01

    In nucleus-nucleus collisions of the systems, 12 C+ 13 C and 13 C+ 16 O- 12 C+ 17 O, the effects of the multi-step transfers and inelastic excitations on the fusion cross sections are investigated in the framework of the coupled-reaction-channel (CRC) method. Strong CRC effects of the multi-step processes are observed. Namely, the valence neutron in 13 C or 17 O plays an important role in the enhancement of the fusion. The potential barrier is effectively lowered with the formation of the covalent molecule of the configuration, 12 C+n+ 12 C or 12 C+n+ 16 O. In the analyses of the system 12 C+ 13 C, however, it is still required to introduce core-core optical potential of lower barrier height in the state of the positive total parity. This could be due to the neck formation with the nucleons contained in two core nuclei. (author)

  17. Incomplete fusion reactions in 16O+159Tb system: Spin distribution measurements

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2015-01-01

    Full Text Available In order to explore the reaction modes on the basis of their entry state spin population, an experiment has been done by employing particle-γ coincidence technique carried out at the Inter University Accelerator Centre, New Delhi. The preliminary analysis conclusively demonstrates, spin distribution for some reaction products populated via complete and/or incomplete fusion of 16O with 159Tb system found to be distinctly different. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states.

  18. Reaching to a featured formula to deduce the energy of the heaviest particles producing from the controlled thermonuclear fusion reactions

    Science.gov (United States)

    Majeed, Raad H.; Oudah, Osamah N.

    2018-05-01

    Thermonuclear fusion reaction plays an important role in developing and construction any power plant system. Studying the physical behavior for the possible mechanism governed energies released by the fusion products to precise understanding the related kinematics. In this work a theoretical formula controlled the general applied thermonuclear fusion reactions is achieved to calculating the fusion products energy depending upon the reactants physical properties and therefore, one can calculate other parameters governed a given reaction. By using this formula, the energy spectrum of 4He produced from T-3He fusion reaction has been sketched with respect to reaction angle and incident energy ranged from (0.08-0.6) MeV.

  19. Breakup-fusion analyses of light ion induced stripping reactions to both bound and unbound regions

    International Nuclear Information System (INIS)

    Lee, Y.J.

    1987-01-01

    The breakup-fusion theory developed recently by our group at the University of Texas has been very successful in explaining observed continuum spectra of particles emitted from breakup type reactions, such as (d,p), (h,p), (h,d), (α,p), and (α,t) reactions. The aim of the present work is to extend the breakup-fusion formalism to calculate the usual stripping reaction, in which a nucleon or a nucleon-cluster is transferred into abound orbit in the target nucleus. With this extension, it is now possible to calculate the spectra of particles emitted from stripping type reactions. We particularly explore the possibility of using the breakup-fusion theory as a spectroscopic tool to obtain information about single particle states in both bound and unbound regions. For this purpose, we extend the theory so as to include the spin-orbit interaction between the transferred particle and the target which has been neglected in all the breakup-fusion studies made in the past. We then apply the thus extended breakup-fusion theory to analyze data of (d,p) and (α,t) reactions. The results of the calculations fit the observed spectra very well and the BF method is shown indeed to be useful for extracting information about the single particle states observed as bumps in both the continuum and discrete regions

  20. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and 3 He ions, respectively. When the plasma was compressed, the d(d,n) 3 He fusion reaction rate increased a factor of five, and the 3 He(d,p) 4 He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling

  1. Direct inner shell ionization accompanying heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1987-07-01

    51 V+ 40 Ar (180 MeV) fusion reaction is studied by means of K X-ray-particle-γ-ray coincidences. K X-ray yields associated with various evaporation residues are determined separately for two ionization processes: the direct ionization by the projectile prior to the nuclear interaction and the postcollisional ionization due to the internal conversion of γ-rays. Implications for possible measurements of nuclear reaction times are discussed. 24 refs., 9 figs., 2 tabs. (author)

  2. Cold fusion reactions with 48Ca

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Jost, D.T.; Tuerler, A.

    1989-04-01

    Cold fusion reactions with 48 Ca on the targets 208 Pb, 209 Bi, 197 Au, 184 W, 180 Hf are reported. The experiments were performed at the velocity filter SHIP of GSI. The maximum cross sections show a steep descent by about four orders of magnitude when going from 224 Th to 228 U as compound nuclei. Between uranium and einsteinium the cross sections stay rather low and increase by about two orders of magnitude for nobelium. For lawrencium the cross section decrease again. 7 figs., 1 tab., 38 refs

  3. Energy dependence of fusion evaporation-residue cross sections in the 28Si+12C reaction

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Mateja, J.F.; Beck, C.; Atencio, S.E.; Dennis, L.C.; Frawley, A.D.; Henderson, D.J.; Janssens, R.V.F.; Kemper, K.W.; Kovar, D.G.; Maguire, C.F.; Padalino, S.J.; Prosser, F.W.; Stephans, G.S.F.; Tiede, M.A.; Wilkins, B.D.; Zingarelli, R.A.

    1993-01-01

    Fusion evaporation-residue cross sections for the 28 Si+ 12 C reaction have been measured in the energy range 18≤E c.m. ≤136 MeV using time-of-flight techniques. Velocity distributions of mass-identified reaction products were used to identify evaporation residues and to determine the complete-fusion cross sections at high energies. The data are in agreement with previously established systematics which indicate an entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models

  4. Evaluation of charged-particle reactions for fusion applications

    International Nuclear Information System (INIS)

    White, R.M.; Resler, D.A.; Warshaw, S.I.

    1991-01-01

    New evaluations of the total reaction cross sections for 2 H(d,n) 3 He, 2 H(d,p) 3 H, 3 H(t,2n) 4 He, 3 H(d,n) 4 He, and 3 He(d,p) 4 He have been completed. These evaluations are based on all known published data from 1946 to 1990 and include over 1150 measured data points from 67 references. The purpose of this work is to provide a consistent and well-documented set of cross sections for use in calculations relating to fusion energy research. A new thermonuclear data file, TDF, and a library of FORTRAN subprograms to read the file have been developed. Calculated from the new evaluations, the TDF file contains information on the Maxwellian-averaged reaction rates as a function of reaction and plasma temperature and the Maxwellian-averaged average energy of the interacting particles and reaction products. Routines are included that provide thermally-broadened spectral information for the secondary reaction products. 67 refs., 18 figs

  5. Fusion and nonfusion phenomena in the 6Li+40Ca reaction at 156 MeV

    International Nuclear Information System (INIS)

    Brzychczyk, J.; Freindl, L.; Grotowski, K.

    1982-01-01

    Reaction products from 6 Li-induced reactions on 40 Ca at 156 MeV have been studied using the dE x E identification as well as the inclusive γ-ray method. The complete fusion cross-section has been found to be σsub(f)=(77 +- 11)mb. The Z distribution of fusion evaporation residues is compared with statistical model predictions. The Z spectrum of reaction products shows a maximum at 15 6 Li break-up. (author)

  6. Fusion and nonfusion phenomena in the 6Li+40Ca reaction at 156 MeV

    International Nuclear Information System (INIS)

    Brzychczyk, J.; Freindl, L.; Grotowski, K.; Majka, Z.; Micek, S.; Planeta, R.; Uniwersytet Jagiellonski, Krakow; Albinska, M.; Buschmann, J.; Klewe-Nebenius, H.; Gils, H.J.; Rebel, H.; Zagromski, S.

    1984-01-01

    Reaction products from 6 Li-induced reactions on 40 Ca at 156 MeV have been studied using the dExE idenitification as well as the inclusive γ-ray method. The complete fusion cross section has been found to be sigmasub(F)=67 +- 20 mb. The Z-distribution of fusion evaporation residues is compared with statistical model predictions. The Z-spectrum of reaction products shows a maximum at 15 6 Li-break-up processes. (orig.)

  7. Fusion Yield Enhancement in Magnetized Laser-Driven Implosions

    International Nuclear Information System (INIS)

    Chang, P. Y.; Fiksel, G.; Hohenberger, M.; Knauer, J. P.; Marshall, F. J.; Betti, R.; Meyerhofer, D. D.; Seguin, F. H.; Petrasso, R. D.

    2011-01-01

    Enhancement of the ion temperature and fusion yield has been observed in magnetized laser-driven inertial confinement fusion implosions on the OMEGA Laser Facility. A spherical CH target with a 10 atm D 2 gas fill was imploded in a polar-drive configuration. A magnetic field of 80 kG was embedded in the target and was subsequently trapped and compressed by the imploding conductive plasma. As a result of the hot-spot magnetization, the electron radial heat losses were suppressed and the observed ion temperature and neutron yield were enhanced by 15% and 30%, respectively.

  8. Investigation of the influence of incomplete fusion on complete fusion of {sup 12}C-induced reactions at {approx} 4-7.2 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Amanuel, F.K. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy); Zelalem, B.; Chaubey, A.K. [Addis Ababa University, Department of Physics, P.O.Box 1176, Addis Ababa (Ethiopia); Agarwal, Avinash [Bareilly College, Department of Physics, Bareilly (India); Rizvi, I.A.; Maheshwari, Anjana; Ahmed, Tauseef [Aligarh Muslim University, Department of Physics, Aligarh (India)

    2011-12-15

    In this paper, we present the results of our investigation of reaction dynamics leading to incomplete fusion of heavy ions at moderate excitation energies, especially the influence of incomplete fusion on complete fusion of {sup 12}C -induced reactions at specific energies {approx} 4-7.2M eV/nucleon. Excitation functions of various reaction products populated via complete and/or incomplete fusions of a {sup 12}C projectile with {sup 93}Nb, {sup 59}Co and {sup 52}Cr targets were measured at several specific energies {approx} 4-7.2 MeV/nucleon, using a recoil catcher technique, followed by off-line {gamma}-ray spectrometry. The measured excitation functions were compared with theoretical values obtained using the PACE4 statistical model code. For representative non-{alpha}-emitting channels in the {sup 12}C + {sup 93}Nb system, the experimentally measured excitation functions were, in general, found to be in good agreement with the theoretical predictions. However, for {alpha}-emitting channels in the {sup 12}C + {sup 93}Nb, {sup 12}C + {sup 59}Co, and {sup 12}C + {sup 52}Cr systems, the measured excitation functions were higher than the predictions of the theoretical model code, which may be credited to incomplete fusion reactions at these energies. An attempt was made to estimate the incomplete fusion fraction for the present systems, which revealed that the fraction was sensitive to the projectile energy and mass asymmetry of the entrance channel. (orig.)

  9. Fusion energy

    International Nuclear Information System (INIS)

    Gross, R.A.

    1984-01-01

    This textbook covers the physics and technology upon which future fusion power reactors will be based. It reviews the history of fusion, reaction physics, plasma physics, heating, and confinement. Descriptions of commercial plants and design concepts are included. Topics covered include: fusion reactions and fuel resources; reaction rates; ignition, and confinement; basic plasma directory; Tokamak confinement physics; fusion technology; STARFIRE: A commercial Tokamak fusion power plant. MARS: A tandem-mirror fusion power plant; and other fusion reactor concepts

  10. Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier

    International Nuclear Information System (INIS)

    Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.

    2008-01-01

    Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions

  11. Study of α-particle multiplicity in 16O+196Pt fusion-fission reaction

    International Nuclear Information System (INIS)

    Kapoor, K.; Kumar, A.; Bansal, N.

    2016-01-01

    Study of dynamics of fusion-fission reaction is one of the interesting parts of heavy-ion-induced nuclear reaction. Extraction of fission time scales using different probes is of central importance for understanding the dynamics of fusion-fission process. In the past, extensive theoretical and experimental efforts have been made to understand the various aspects of the heavy ion induced fusion-fission reactions. Compelling evidences have been obtained from the earlier studies that the fission decay of hot nuclei is protracted process i.e. slowed down relative to the expectations of the standard statistical model, and large dynamical delays are required due to this hindrance. Nuclear dissipation is assumed to be responsible for this delay and more light particles are expected to be emitted during the fission process. One of neutron multiplicity measurements have been performed for the 16,18 O+ 194,198 Pt populating the CN 210,212,214,216 Rn and observed fission delay due to nuclear viscosity. In order to have complete understanding for the dynamics of 212 Rn nucleus, we measured the charged particle multiplicity for 16 O+ 196 Pt system. Study of charged particles will give us more information about the emitter in comparison to neutrons as charged particles faces Coulomb barrier and are more sensitive probe for understanding the dynamics of fusion-fission reactions. In the present work, we are reporting some of the preliminary results of charged particle multiplicity

  12. Enhanced chemical weapon warning via sensor fusion

    Science.gov (United States)

    Flaherty, Michael; Pritchett, Daniel; Cothren, Brian; Schwaiger, James

    2011-05-01

    Torch Technologies Inc., is actively involved in chemical sensor networking and data fusion via multi-year efforts with Dugway Proving Ground (DPG) and the Defense Threat Reduction Agency (DTRA). The objective of these efforts is to develop innovative concepts and advanced algorithms that enhance our national Chemical Warfare (CW) test and warning capabilities via the fusion of traditional and non-traditional CW sensor data. Under Phase I, II, and III Small Business Innovative Research (SBIR) contracts with DPG, Torch developed the Advanced Chemical Release Evaluation System (ACRES) software to support non real-time CW sensor data fusion. Under Phase I and II SBIRs with DTRA in conjunction with the Edgewood Chemical Biological Center (ECBC), Torch is using the DPG ACRES CW sensor data fuser as a framework from which to develop the Cloud state Estimation in a Networked Sensor Environment (CENSE) data fusion system. Torch is currently developing CENSE to implement and test innovative real-time sensor network based data fusion concepts using CW and non-CW ancillary sensor data to improve CW warning and detection in tactical scenarios.

  13. Synthesis and decay process of superheavy nuclei with Z=119-122 via hot-fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Ghahramany, N.; Ansari, A. [Shiraz University, Department of Physics and Biruni Observatory, College of Science, Shiraz (Iran, Islamic Republic of)

    2016-09-15

    In this research article attempts have been made to calculate the superheavy-nuclei synthesis characteristics including, the potential energy parameters, fusion probability, fusion and evaporation residue (ER) cross sections as well as, decay properties of compound nucleus and the residue nuclei formation probability for elements with Z=119-122 by using the hot-fusion reactions. It is concluded that, although a selection of double magic projectiles such as {sup 48}Ca with high binding energy, simplifies the calculations significantly due to spherical symmetric shape of the projectile, resulting in high evaporation residue cross section, unfortunately, nuclei with Z > 98 do not exist in quantities sufficient for constructing targets for the hot-fusion reactions. Therefore, practically our selection is fusion reactions with titanium projectile because the mass production of target nuclei for experimental purposes is more feasible. Based upon our findings, it is necessary, for new superheavy-nuclei production with Z > 119, to use neutron-rich projectiles and target nuclei. Finally, the maximal evaporation residue cross sections for the synthesis of superheavy elements with Z=119-122 have been calculated and compared with the previously founded ones in the literature. (orig.)

  14. Description of heavy-ion fusion in terms of direct reaction theory

    International Nuclear Information System (INIS)

    Hong, S.W.

    1987-01-01

    A direct reaction description of the heavy-ion fusion, proposed by Udagawa, Kim and Tamura, has been successfully used in calculating the fusion cross sections and the spin distributions for a number of systems in the energy regions from the sub-barrier to the above-barrier region. A fusion potential is introduced in this theory and the radius of the fusion potential is treated as an adjustable parameter. The theory is thus a one-parameter theory. The results obtained by Udagawa, Kim and Tamura showed that the radius parameter ranges from 1.4 to 1.5 fm, which is much larger than the radius (1.0 fm) used in other models. A hard evidence is shown to demonstrate the necessity of the long-ranged fusion potential radius in the near-barrier region. In the above-barrier region, the use of the energy-dependent optical potential and the energy-dependent fusion potential radius is proved to be essential in reproducing the measured fusion cross sections. As a further application of the theory, the double folded potential model is utilized to provide the real part of the optical potential. The imaginary part of the optical potential is determined so that not only the elastic scattering but also the fusion cross sections can be reproduced

  15. Comparison of cross sections for C+O reactions in the second regime of complete fusion

    International Nuclear Information System (INIS)

    Beck, C.; Haas, F.; Freeman, R.M.; Heusch, B.; Coffin, J.P.; Guillaume, G.; Rami, F.; Wagner, P.

    1985-01-01

    Kinetic energy spectra, angular distributions, and elemental yield distributions have been measured for the 12 C + 16 O, 12 C + 18 O and 13 C + 17 O reaction products over an energy range from 2 to 7 times the Coulomb barrier energy. A careful kinematic analysis of the evaporation residues and comparisons with statistical model calculations show that fusion proceeds with full momentum transfer followed by a statistical decay of the compound nucleus. The competition between complete fusion process and peripheral reactions in the 12 C + 16 O system is less important than for the 12 C + 18 O and 13 C + 17 O reactions. The unexpectedly high 12 C + 16 O complete fusion cross sections are related to the possible occurence of a superdeformation of the 28 Si compound nucleus

  16. Effect of a generalized particle momentum distribution on plasma nuclear fusion rates

    International Nuclear Information System (INIS)

    Kim, Yeong E.; Zubarev, Alexander L.

    2006-01-01

    We investigate the effect of a generalized particle momentum distribution derived by Galitskii and Yakimets (GY) on nuclear reaction rates in plasma. We derive an approximate semi-analytical formula for nuclear fusion reaction rate between nuclei in a plasma (quantum plasma nuclear fusion; or QPNF). The QPNF formula is applied to calculate deuteron-deuteron fusion rate in a plasma, and the results are compared with the results calculated with the conventional Maxwell-Boltzmann velocity distribution. As an application, we investigate the deuteron-deuteron fusion rate for mobile deuterons in a deuterated metal/alloy. The calculated deuteron-deuteron fusion rates at low energies are enormously enhanced due to the modified tail of the GY's generalized momentum distribution. Our preliminary estimates indicate also that the deuteron-lithium (D+Li) fusion rate and the proton-lithium (p+Li) fusion rate in a metal/alloy at ambient temperatures are also substantially enhanced. (author)

  17. Recent experimental results in sub- and near-barrier heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Montagnoli, Giovanna [Dipartimento di Fisica e Astronomia, Universita di Padova (Italy); INFN Sezione di Padova (Italy); Stefanini, Alberto M. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

    2017-08-15

    Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus is mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations overpredict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars. (orig.)

  18. Maturation of the viral core enhances the fusion of HIV-1 particles with primary human T cells and monocyte-derived macrophages

    International Nuclear Information System (INIS)

    Jiang Jiyang; Aiken, Christopher

    2006-01-01

    HIV-1 infection requires fusion of viral and cellular membranes in a reaction catalyzed by the viral envelope proteins gp120 and gp41. We recently reported that efficient HIV-1 particle fusion with target cells is linked to maturation of the viral core by an activity of the gp41 cytoplasmic domain. Here, we show that maturation enhances the fusion of a variety of recombinant viruses bearing primary and laboratory-adapted Env proteins with primary human CD4 + T cells. Overall, HIV-1 fusion was more dependent on maturation for viruses bearing X4-tropic envelope proteins than for R5-tropic viruses. Fusion of HIV-1 with monocyte-derived macrophages was also dependent on particle maturation. We conclude that the ability to couple fusion to particle maturation is a common feature of HIV-1 Env proteins and may play an important role during HIV-1 replication in vivo

  19. Search for entrance channel effects in fusion reactions via neutron evaporation

    International Nuclear Information System (INIS)

    Ajay Kumar; Kaur, J.; Kumar, A.; Singh, G.; Govil, I.M.; Rakesh Kumar; Datta, S.K.; Chatterjee, M.B.; Yogi, B.K.

    2001-01-01

    It is generally expected that the compound nuclei formed at the given excitation energies and the angular momenta follow a statistical decay pattern independent of a particular reaction that led to fusion. In order to search the entrance channel effects in the decay of compound nucleus, the reaction 16 O + 64 Zn at oxygen beam energy of 91 MeV and 95 MeV are investigated

  20. Competition between peripheral and central emission in incomplete fusion reactions

    International Nuclear Information System (INIS)

    Tricoire, H.

    1984-01-01

    In the frame of a classical model we show that the emission of fast particles in incomplete fusion reactions may occur either from a PEP emission which happens preferentially at low angular momenta or from an inertial emission with a maximum of the cross section located near the critical angular momentum for complete fusion. The competition of these mechanisms depends crucialy of the interaction between the particle to be emitted and the target nucleus. Numerical calculations are performed with various particle target potentials. Using a proximity potential, one gets results in good agreement with experimental data

  1. Study of heavy ion fusion reaction of 58Ni + 24Mg at 11 MeV/nucleon

    International Nuclear Information System (INIS)

    Shea, J.Y.

    1991-01-01

    This thesis presents a study of the heavy ion fusion reaction in which a 58 Ni projectile bombards a 24 Mg target at 11 MeV/nucleon. The incident projectile energy was purposefully chosen so as the system studied to be at the onset of the more complex and interesting phenomenon of incomplete fusion. The physics motivation is to probe the central collision of a heavy, energetic, and asymmetric system by means of both inclusive and exclusive experimental measurements. The experiment was performed at HHIRF (Holifield Heavy Ion Research Facility) by using the coupled accelerators at Oak Ridge National Laboratory. The reaction products were measured by the new open-quotes HILI-Ringclose quotes large solid angle detector system at Oak Ridge National Laboratory. The thesis discusses the physics motivation and the systematics of heavy ion fusion reactions. Details of the design and construction of a new CsI(T1) Ring detector is given. Since this is the first such study performed on the Heavy Ion Light Ion (HILI) detector, an extensive discussion of the calibration procedures and the data reduction methods are given. The fusion reaction data were analyzed in both inclusive and exclusive modes with the result that a valuable new perspective on the deconvolution of the reaction mechanism has been achieved

  2. Application of spin-polarized fuel to fusion reactions

    International Nuclear Information System (INIS)

    Wakuta, Y.; Nakao, Y.; Honda, T.; Honda, Y.; Nakashima, H.

    1990-01-01

    Studies on the application of the polarized fuel to the inertial fusion reaction have been carried out. It is shown that the use of the spin-polarized fuel D vector·T vector or D vector· 3 (He)vector reduces the irradiating laser power more than 50% compared with the use of the unpolarized fuel. The depolarization rate of the polarized fuel during the fusing process is found to be almost negligible. (author)

  3. Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening

    DEFF Research Database (Denmark)

    Nocente, M.; Källne, J.; Salewski, Mirko

    2015-01-01

    First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution instrume......First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution...... instruments. An analytical formula for the spectrum from Maxwellian plasmas, which extends to higher temperatures than the results previously available in the literature, has been derived and used to discuss the assumptions and limitations of earlier models. In case of radio-frequency injection, numerical...... results based on a Monte Carlo method are provided, focusing in particular on improved relations between the peak shift and width from the reaction and the temperature of protons accelerated by radio-frequency heating.The results presented in this paper significantly improve the accuracy of diagnostic...

  4. Some introductory notes on the problem of nuclear energy by controlled fusion reactions

    International Nuclear Information System (INIS)

    Pedretti, E.

    1988-01-01

    Written for scientists and technologist interested in, but unfamiliar with nuclear energy by controlled fusion reactions, this ''sui generis'' review paper attempts to provide the reader, as shortly as possible, with a general idea of the main issues at stake in nuclear fusion research. With the purpose of keeping this paper within a reasonable length, the various subjects are only outlined in their essence, basic features, underlying principles, etc., without entering into details, which are left to the quoted literature. Due to the particular readership of this journal, vacuum problems and/or aspects of fusion research anyhow related with vacuum science and technology are evidentiated. After reviewing fusion reactions' cross sections, fusion by accelerators and muon catalyzed fusion are described, followed by mention of Lawson's criteria and of plasma confinement features. Then, inertial confinement fusion is dealt with, also including one example of laser system (Nova), one of accelerator facility (PBFA-II) and some guesses on the classified Centurion-Halite program. Magnetic confinement fusion research is also reviewed, in particulary reporting one example of linear machine (MFTF-B), two examples of toroidal machines other than Tokamak (ATF and Eta-Beta-II) and various examples of Tokamaks, including PBX and PBX-M; TFTR, JET, JT-60, T-15 and Tore-Supra (large machines); Alcator A, FT, Alcator C/MTX, Alcator C-Mod and T-14 (compact high field machines). Tokamaks under design for ignition experiments (Ignitor, CIT, Ignitex and NET) are also illustrated. Thermal conversion of fusion power and direct generation of electricity are mentioned; conceptual design of fusion power plants are considered and illustrated by four examples (STARFIRE, WILDCAT, MARS and CASCADE). The D 3 He fuel cycle is discussed as an alternative more acceptable than Deuterium-Tritium, and thw Candor proposal is reported. After recalling past experience of the fission power development, some

  5. Formation, separation and detection of evaporation residues produced in complete fusion reactions

    CERN Document Server

    Sagaidak, R N

    2015-01-01

    Some aspects of formation, separation and detection of evaporation residues (ERs) produced in complete fusion reactions induced by accelerated heavy ions are considered. These reactions allow to obtain heavy neutron-deficient nuclei and to study their properties. The statistical model analysis of the production cross sections for these nuclei obtained in a wide range of their neutron numbers allows to trace the changes in their macroscopic properties such as fission barriers. The fusion probability of massive projectile and target nuclei is of interest. Empirical estimates of this value allow to verify the predictions of theoretical models for the optimal ways of synthesis of unknown nuclei. Some peculiarities in the separation and detection of ERs in experiments are briefly considered by the example of the Ra ERs produced in the 12 C+Pb reactions. The reliable cross sections for ERs produced in very asymmetric projectile-target combination, such as 12 C+Pb, are important for the em...

  6. Magneized target fusion: An overview of the concept

    International Nuclear Information System (INIS)

    Kirkpatrick, R.C.

    1994-01-01

    Magnetized target fusion (MTF) seeks to take advantage of the reduction of thermal conductivity through the application of a strong magneticfield and thereby ease the requirements for reaching fusion conditions in a thermonuclear (TN) fusion fuel. A potentially important benefit of the strong field in the partial trapping of energetic charged particles to enhance energy deposition by the TN fusion reaction products. The essential physics is described. MTF appears to lead to fusion targets that require orders of magnitude less power and intensity for fusion ignition than currently proposed (unmagnetized) inertial confinement fusion (ICF) targets do, making some very energetic pulsed power drivers attractive for realizing controlled fusion

  7. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    International Nuclear Information System (INIS)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H.

    2002-01-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H 2 O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction

  8. Fusion reaction spectra produced by anisotropic fast ions in the PLT tokamak

    International Nuclear Information System (INIS)

    Heidbrink, W.W.

    1984-02-01

    For beam-target fusion reactions, collimated measurements of the energy spectrum of one of the reaction products can provide information on the degree of anisotropy of the reacting beam ions. Measurements of the spectrum of 15 MeV protons produced by reactions between energetic 3 He ions and relatively cold deuterons during fast wave minority heating in the PLT tokamak indicate that the velocity distribution of fast 3 He ions is peaked perpendicular to the tokamak magnetic field

  9. Evaluation of early tissue reactions after lumbar intertransverse process fusion using CT in a rabbit

    International Nuclear Information System (INIS)

    Shinbo, Jun; Mainil-Varlet, Pierre; Watanabe, Atsuya; Pippig, Suzanne; Koener, Jens; Anderson, Suzanne E.

    2010-01-01

    The objective of the study was to evaluate tissue reactions such as bone genesis, cartilage genesis and graft materials in the early phase of lumbar intertransverse process fusion in a rabbit model using computed tomography (CT) imaging with CT intensity (Hounsfield units) measurement, and to compare these data with histological results. Lumbar intertransverse process fusion was performed on 18 rabbits. Four graft materials were used: autograft bone (n=3); collagen membrane soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) (n=5); granular calcium phosphate (n=5); and granular calcium phosphate coated with rhBMP-2 (n=5). All rabbits were euthanized 3 weeks post-operatively and lumbar spines were removed for CT imaging and histological examination. Computed tomography imaging demonstrated that each fusion mass component had the appropriate CT intensity range. CT also showed the different distributions and intensities of bone genesis in the fusion masses between the groups. Each component of tissue reactions was identified successfully on CT images using the CT intensity difference. Using CT color mapping, these observations could be easily visualized, and the results correlated well with histological findings. The use of CT intensity is an effective approach for observing and comparing early tissue reactions such as newly synthesized bone, newly synthesized cartilage, and graft materials after lumbar intertransverse process fusion in a rabbit model. (orig.)

  10. Fusion cross-sections of 16O+16O reaction in pseudonucleon picture

    International Nuclear Information System (INIS)

    Mishra, R.C.; Waghmare, Y.R.

    1991-01-01

    Fusion cross-sections for 16 O+ 16 O reaction are calculated in classical equations of motion approach using the pseudonucleon picture. These calculated fusion cross-sections are very close to measured values than earlier calculated using the same NN interaction. The aim of the paper is to test the pseudonucleon picture. Use of this picture does not require one to consider the number of relative random orientations of the colliding clusters. (author). 22 refs., 2 tabs., 4 figs

  11. Catalysis of Nuclear Reactions by Electrons

    Science.gov (United States)

    Lipoglavšek, Matej

    2018-01-01

    Electron screening enhances nuclear reaction cross sections at low energies. We studied the nuclear reaction 1H(19F,αγ)16O in inverse kinematics in different solid hydrogen targets. Measured resonance strengths differed by up to a factor of 10 in different targets. We also studied the 2H(p,γ)3He fusion reaction and observed electrons emitted as reaction products instead of γ rays. In this case electron screening greatly enhances internal conversion probability.

  12. Hybrid Image Fusion for Sharpness Enhancement of Multi-Spectral Lunar Images

    Science.gov (United States)

    Awumah, Anna; Mahanti, Prasun; Robinson, Mark

    2016-10-01

    Image fusion enhances the sharpness of a multi-spectral (MS) image by incorporating spatial details from a higher-resolution panchromatic (Pan) image [1,2]. Known applications of image fusion for planetary images are rare, although image fusion is well-known for its applications to Earth-based remote sensing. In a recent work [3], six different image fusion algorithms were implemented and their performances were verified with images from the Lunar Reconnaissance Orbiter (LRO) Camera. The image fusion procedure obtained a high-resolution multi-spectral (HRMS) product from the LRO Narrow Angle Camera (used as Pan) and LRO Wide Angle Camera (used as MS) images. The results showed that the Intensity-Hue-Saturation (IHS) algorithm results in a high-spatial quality product while the Wavelet-based image fusion algorithm best preserves spectral quality among all the algorithms. In this work we show the results of a hybrid IHS-Wavelet image fusion algorithm when applied to LROC MS images. The hybrid method provides the best HRMS product - both in terms of spatial resolution and preservation of spectral details. Results from hybrid image fusion can enable new science and increase the science return from existing LROC images.[1] Pohl, Cle, and John L. Van Genderen. "Review article multisensor image fusion in remote sensing: concepts, methods and applications." International journal of remote sensing 19.5 (1998): 823-854.[2] Zhang, Yun. "Understanding image fusion." Photogramm. Eng. Remote Sens 70.6 (2004): 657-661.[3] Mahanti, Prasun et al. "Enhancement of spatial resolution of the LROC Wide Angle Camera images." Archives, XXIII ISPRS Congress Archives (2016).

  13. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    International Nuclear Information System (INIS)

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

    2015-01-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the 10,13,15 C+ 12 C fusion reactions at energies around the Coulomb barrier

  14. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    Energy Technology Data Exchange (ETDEWEB)

    Carnelli, P.F.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Almaraz-Calderon, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Rehm, K.E., E-mail: rehm@anl.gov [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Albers, M.; Alcorta, M.; Bertone, P.F.; Digiovine, B.; Esbensen, H. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Fernández Niello, J. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Universidad Nacional de San Martín, Campus Miguelete, B1650BWA San Martín, Buenos Aires (Argentina); Henderson, D.; Jiang, C.L. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Lai, J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Marley, S.T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R.C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel); Ugalde, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2015-11-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the {sup 10,13,15}C+{sup 12}C fusion reactions at energies around the Coulomb barrier.

  15. Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

    Science.gov (United States)

    Kaur, Gurpreet; Hagino, K.; Rowley, N.

    2018-06-01

    The vast knowledge regarding the strong influence of quadrupole deformation β2 of colliding nuclei in heavy-ion sub-barrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as β4 and β6 deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of β4 of the projectile nucleus in the fusion of the 28Si+92Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and value of the β4 parameter of the projectile, 28Si, and confirmed that the 28Si nucleus has a large positive β4. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult because of experimental constraints.

  16. Elastic scattering and fusion studies in the reactions $^{10,11}$Be + $^{64}$Zn

    CERN Multimedia

    2002-01-01

    We propose to measure elastic scattering and fusion excitation functions for the reactions $^{10,11}$Be + $^{64}$Zn at 3.1 MeV/u . The aim of the experiment is to investigate possible effects of the halo structure of the $^{11}$Be nucleus on the reaction mechanisms at energy around the Coulomb barrier. For this purpose a comparison with the reaction induced by the $^{10}$Be nucleus is required.

  17. Application of the high-spin isomer beams to the secondary fusion reaction and the measurement of g-factor

    International Nuclear Information System (INIS)

    Watanabe, H.; Asahi, K.; Kishida, T.; Ueno, H.; Sato, W.; Yoshimi, A.; Kobayashi, Y.; Kameda, D.; Miyoshi, H.; Fukuchi, T.; Wakabayashi, Y.; Sasaki, T.; Kibe, M.; Hokoiwa, N.; Odahara, A.; Cederwall, B.; Lagergren, K.; Podolyak, Zs.; Ishihara, M.; Gono, Y.

    2004-01-01

    A technique for providing high-spin isomers as probes of the fusion reaction and the measurement of g-factor has been worked out at RIKEN. In the study of the fusion reaction 12 C( 145m Sm,xn) 157-x Er, the γ rays emitted from the fusion-evaporation residue 154 Er have been successfully observed. The nuclear g-factor of the T 1/2 = 28 ns high-spin isomer in 149 Dy has been measured with the γ-ray TDPAD method

  18. Complete and incomplete fusion dynamics of {sup 6,7}Li + {sup 159}Tb reactions near the Coulomb barrier

    Energy Technology Data Exchange (ETDEWEB)

    Gautam, Manjeet Singh [Thapar University, School of Physics and Materials Science, Patiala (India); Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Grover, Neha; Sharma, Manoj K. [Thapar University, School of Physics and Materials Science, Patiala (India)

    2017-01-15

    The complete fusion (CF) and incomplete fusion (ICF) cross-sections are estimated for {sup 6,} {sup 7}Li + {sup 159}Tb reactions using the energy-dependent Woods-Saxon potential model (EDWSP model) and dynamical cluster-decay model (DCM). The CF data of the {sup 6}Li + {sup 159}Tb({sup 7}Li + {sup 159}Tb) reaction at above barrier energies is suppressed with reference to expectations of the EDWSP model by 25% (20%) which is smaller than the reported data by ∝ 9% (6%). This suppression is correlated with the projectile breakup effect. The projectiles {sup 6,7}Li are loosely bound systems, which may break up into charged fragments prior to reaching the fusion barrier and subsequently one of the fragment is captured by the target leading to the suppression of fusion data at above barrier energies. The sum of CF and ICF, which is termed as total fusion cross-section (TF), removes the discrepancies between theoretical predictions and the above barrier complete fusion data and hence is adequately explained via the EDWSP model over a wide range of energy spread across the Coulomb barrier. In addition to fusion, the decay mechanism of {sup 6}Li + {sup 159}Tb reaction is studied within the framework of the dynamical cluster-decay model (DCM). The breakup of the projectile ({sup 6}Li) in the entrance channel indicates the presence of ICF, which is investigated further using the collective clusterization approach of DCM. The present theoretical analysis suggests that a larger barrier modification is needed to address the fusion data of chosen reactions in the below barrier energy region. (orig.)

  19. Estimation of the {alpha} particles and neutron distribution generated during a fusion reaction; Evaluation de la distribution des particules {alpha} et des neutrons issus de la reaction de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Dellacherie, S.

    1997-12-01

    The respective distributions (or density probabilities) of {alpha} particles and neutrons have been modeled using a Monte-Carlo method for the thermonuclear fusion reaction D + T {yields} {alpha} + n + 17.6 MeV. (N.T.).

  20. Achievement of solid-state plasma fusion ('Cold-Fusion')

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue-Chang

    1995-01-01

    Using a 'QMS' (Quadrupole Mass Spectrometer), the authors detected a significantly large amount (10 20 -10 21 [cm -3 ]) of helium ( 2 4 He), which was concluded to have been produced by a deuterium nuclear reaction within a host solid. These results were found to be fully repeatable and supported the authors' proposition that solid state plasma fusion ('Cold Fusion') can be generated in energetic deuterium Strongly Coupled Plasma ('SC-plasma'). This fusion reaction is thought to be sustained by localized 'Latticequake' in a solid-state media with the deuterium density equivalent to that of the host solid. While exploring this basic proposition, the characteristic differences when compared with ultra high temperature-state plasma fusion ('Hot Fusion') are clarified. In general, the most essential reaction product in both types of the deuterium plasma fusion is considered to be helium, irrespective of the 'well-known and/or unknown reactions', which is stored within the solid-state medium in abundance as a 'Residual Product', but which generally can not enter into nor be released from host-solid at a room temperature. Even measuring instruments with relatively poor sensitivity should be able to easily detect such residual helium. An absence of residual helium means that no nuclear fusion reaction has occurred, whereas its presence provides crucial evidence that nuclear fusion has, in fact, occurred in the solid. (author)

  1. Light particle revelation on incomplete fusion reactions

    International Nuclear Information System (INIS)

    Gillibert, A.

    1984-01-01

    Incomplete fusion reactions have been studied through light particles emission in the reaction 116 Sn + 16 O at 125 MeV (ALICE facility in Orsay). We measured energy angular distributions and correlations between any two of these particles (α particles, protons, neutrons), while γ multiplicity measurements provide us fuller informations. From collected data, the following pictures can be drawn: - the only fast particles observed are α particles, while protons and neutrons seem to come only from statistical evaporation; - outgoing channels where two α particles are emitted cannot be solely explained by the sequential emission of 8 Be → 2α: about half of the cross section proceeds from statistical evaporation of one α particle. Accordingly, 2αxn channels do not necessarily agree with high value of angular momentum in the entrance channel. From the study of experimental results in the yrast plane, we can assign a large width to the angular momentum distribution [fr

  2. The abundant excess heat production during low energy nuclear reaction in the nano scale solid state the cold fusion, 14 years' legacy

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho; Miley, George H.; Lipson, Andrei; Kim, Sung O.; Luo, Nie; Castano, Carlos H. [The University of Illinois, Urbana (United States)

    2002-05-01

    The quite abundant excess heat and radioactive materials are found during the solid state reaction. This phenomenon has done during the Low Energy Nuclear Reaction (LENR) in the nano scale molecular structure electrodes and Hydrogen compound electrolytes. The Palladium (or Nickel) and Platinum are incorporated as the electrode and the Light Water (H{sub 2}O) as the electrolyte. The excess heat was produced up to 40% in year 2001. The Alpha particles are also detected. The computer code, Coherent Lattice Accelerator Inter-Ionic Reaction Enhancer (CLAIRE) Code System, is constructed for the simulation. The 0.1 A of the distance between two the Hydrogen ion (proton) and Palladium nucleus is the critical point for the nuclear fusion reaction.

  3. A classical approach in simple nuclear fusion reaction 1H2+1H3 using two-dimension granular molecular dynamics model

    International Nuclear Information System (INIS)

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

    2012-01-01

    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 1 H 2 and 1 H 3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2 He 4 nucleus.

  4. Pulsed fusion space propulsion: Computational Magneto-Hydro Dynamics of a multi-coil parabolic reaction chamber

    Science.gov (United States)

    Romanelli, Gherardo; Mignone, Andrea; Cervone, Angelo

    2017-10-01

    Pulsed fusion propulsion might finally revolutionise manned space exploration by providing an affordable and relatively fast access to interplanetary destinations. However, such systems are still in an early development phase and one of the key areas requiring further investigations is the operation of the magnetic nozzle, the device meant to exploit the fusion energy and generate thrust. One of the last pulsed fusion magnetic nozzle design is the so called multi-coil parabolic reaction chamber: the reaction is thereby ignited at the focus of an open parabolic chamber, enclosed by a series of coaxial superconducting coils that apply a magnetic field. The field, beside confining the reaction and preventing any contact between hot fusion plasma and chamber structure, is also meant to reflect the explosion and push plasma out of the rocket. Reflection is attained thanks to electric currents induced in conductive skin layers that cover each of the coils, the change of plasma axial momentum generates thrust in reaction. This working principle has yet to be extensively verified and computational Magneto-Hydro Dynamics (MHD) is a viable option to achieve that. This work is one of the first detailed ideal-MHD analysis of a multi-coil parabolic reaction chamber of this kind and has been completed employing PLUTO, a freely distributed computational code developed at the Physics Department of the University of Turin. The results are thus a preliminary verification of the chamber's performance. Nonetheless, plasma leakage through the chamber structure has been highlighted. Therefore, further investigations are required to validate the chamber design. Implementing a more accurate physical model (e.g. Hall-MHD or relativistic-MHD) is thus mandatory, and PLUTO shows the capabilities to achieve that.

  5. Enhanced fuel production in thorium fusion hybrid blankets utilizing uranium multipliers

    International Nuclear Information System (INIS)

    Pitulski, R.H.; Chapin, D.L.; Klevans, E.

    1979-01-01

    The multiplication of 14 MeV D-T fusion neutrons via (n,2n), (n,3n), and fission reactions by 238 U is well known and established. This study consistently evaluates the effectiveness of a depleted (tails) UO 2 multiplier on increasing the production of 233 U and tritium in a thorium/lithium fusion--fission hybrid blanket. Nuclear performance is evaluated as a function of exposure and zone thickness

  6. Study of fusion mechanism of halo nuclear 11Be+208Pb by applying QMD model

    International Nuclear Information System (INIS)

    Wang Ning; Li Zhuxia

    2001-01-01

    The authors have studied the fusion reaction for 11 Be + 208 Pb near barrier by applying QMD model, and find that in t he fusion reaction induced by halo nuclei there simultaneously exist two mechanisms competing with each other. On one hand, 11 Be is a weakly bound nuclear system and is easily broke up caused by the interaction with target, when it approaches to target, so the fusion cross section is suppressed. On the other hand, several neutrons of 11 Be transfer into 208 Pb and interact with 208 Pb to cause the local radius of 208 Pb increase and result in an enhancement of fusion cross section. The fusion cross sections calculated show an enhancement near barrier, and the calculated results agree with the experimental data reasonably well

  7. Collinear laser spectroscopy on In isotopes from heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Ulm, G.

    1984-07-01

    Indium isotopes 107-111 were produced by 16 O-fusion reactions and investigated in a collinear laser geometry. The hyperfine structure and isotopic shifts are measured and the deduced magnetic dipole moments are in agreement with shell model calculations. The nuclear charge radii are determined from the isotopic shifts. (WL)

  8. Liquid-drop effects in sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Barbosa, V C; Canto, L F; Donangelo, R

    1988-01-28

    We introduce an operational measure for the enhancement of the fusion cross section at sub-barrier energies in terms of an asymptotic energy shift ..delta..E. It is shown that ..delta..E has a continuously growing trend with the size of the system. This trend is explained in terms of neck formation using the liquid-drop model. Deviations from this trend are attributed to strong coupling to specific channels.

  9. Low-energy nuclear reaction of the 14N+169Tm system: Incomplete fusion

    Science.gov (United States)

    Kumar, R.; Sharma, Vijay R.; Yadav, Abhishek; Singh, Pushpendra P.; Agarwal, Avinash; Appannababu, S.; Mukherjee, S.; Singh, B. P.; Ali, R.; Bhowmik, R. K.

    2017-11-01

    Excitation functions of reaction residues produced in the 14N+169Tm system have been measured to high precision at energies above the fusion barrier, ranging from 1.04 VB to 1.30 VB , and analyzed in the framework of the statistical model code pace4. Analysis of α -emitting channels points toward the onset of incomplete fusion even at slightly above-barrier energies where complete fusion is supposed to be one of the dominant processes. The onset and strength of incomplete fusion have been deduced and studied in terms of various entrance channel parameters. Present results together with the reanalysis of existing data for various projectile-target combinations conclusively suggest strong influence of projectile structure on the onset of incomplete fusion. Also, a strong dependence on the Coulomb effect (ZPZT) has been observed for the present system along with different projectile-target combinations available in the literature. It is concluded that the fraction of incomplete fusion linearly increases with ZPZT and is found to be more for larger ZPZT values, indicating significantly important linear systematics.

  10. Smooth transition from sudden to adiabatic states in heavy-ion fusion reactions at deep-subbarrier incident energies

    International Nuclear Information System (INIS)

    Takatoshi, Ichikawa; Kouichi, Hagino; Akira, Iwamoto

    2011-01-01

    We propose a novel extension of the standard coupled-channel (CC) model in order to account for the steep falloff of fusion cross sections at deep-subbarrier incident energies. We introduce a damping factor in the coupling potential in the CC model, simulating smooth transitions from sudden to adiabatic states in deep- subbarrier fusion reactions. The CC model extended with the damping factor can reproduce well not only the steep falloff of the fusion cross section but also the saturation of the logarithmic derivatives for the fusion cross sections at deep-subbarrier energies for the 16 O+ 208 Pb, 64 Ni+ 64 Ni, and 58 Ni+ 58 Ni reactions at the deep-subbarrier energies. The important point in our model is that the transition takes place at different places for each Eigen channel. We conclude that the smooth transition from the two-body to the adiabatic one-body potential is responsible for the steep falloff of the fusion cross section

  11. Fusion and direct reactions for strongly and weakly bound projectiles

    International Nuclear Information System (INIS)

    Hugi, M.; Lang, J.; Mueller, R.; Ungricht, E.; Bodek, K.; Jarczyk, L.; Kamys, B.; Magiera, A.; Strzalkowski, A.; Willim, G.

    1981-01-01

    The interaction of 6 Li, 9 Be and 12 C projectiles with a 28 Si target was investigated by measuring the angular distributions of the elasitcally scattered projectiles and of the emitted protons, deuterons and α-particles. The experiment was perfomred in order to deduce direct and compound nucleus process contributions to the total reaction cross section and to study the influence of the projectile structure on the relative importance of these two mechanisms. Optical model parameters and therefore the total reaction cross section are strongly influenced by the binding energy of the projectile. The parameters of the Glas-Mosel describing the fusion reaction vary smoothly with the atomic number. In the system 9 B + 28 Si around 50% of all reactions are direct processes even at energies near the Coulomb barrier, whereas in the other systeme the direct part amounts to 15% ( 12 C) and 30% ( 6 Li) only. (orig.)

  12. Fusion and quasifission studies for the 40Ca+186W,192Os reactions

    Science.gov (United States)

    Prasad, E.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; Palshetkar, C. S.; Rafferty, D. C.; Ramachandran, K.; Simenel, C.; Wakhle, A.

    2017-09-01

    Background: All elements above atomic number 113 have been synthesized using hot fusion reactions with calcium beams on statically deformed actinide target nuclei. Quasifission and fusion-fission are the two major mechanisms responsible for the very low production cross sections of superheavy elements. Purpose: To achieve a quantitative measurement of capture and quasifission characteristics as a function of beam energy in reactions forming heavy compound systems using calcium beams as projectiles. Methods: Fission fragment mass-angle distributions were measured for the two reactions 40Ca+186W and 40C+192Os, populating 226Pu and 232Cm compound nuclei, respectively, using the Heavy Ion Accelerator Facility and CUBE spectrometer at the Australian National University. Mass ratio distributions, angular distributions, and total fission cross sections were obtained from the experimental data. Simulations to match the features of the experimental mass-angle distributions were performed using a classical phenomenological approach. Results: Both 40Ca+186W and 40C+192Os reactions show strong mass-angle correlations at all energies measured. A maximum fusion probability of 60 -70 % is estimated for the two reactions in the energy range of the present study. Coupled-channels calculations assuming standard Woods-Saxon potential parameters overpredict the capture cross sections. Large nuclear potential diffuseness parameters ˜1.5 fm are required to fit the total capture cross sections. The presence of a weak mass-asymmetric quasifission component attributed to the higher angular momentum events can be reproduced with a shorter average sticking time but longer mass-equilibration time constant. Conclusions: The deduced above-barrier capture cross sections suggest that the dissipative processes are already occurring outside the capture barrier. The mass-angle correlations indicate that a compact shape is not achieved for deformation aligned collisions with lower capture barriers

  13. Fusability and fissionability in 86Kr induced reactions near and below the fusion barrier

    International Nuclear Information System (INIS)

    Reisdorf, W.; Hessberger, F.P.; Hildenbrand, K.D.; Hofmann, S.; Muenzenberg, G.; Schmidt, K.H.; Schneider, W.F.W.; Suemmerer, K.; Wirth, G.; Kratz, J.V.; Schlitt, K.; Sahm, C.C.

    1985-04-01

    Evaporation-residue excitation functions for the reactions 86 Kr + sup(70,76)Ge, sup(92,100)Mo, sup(99,102,104)Ru have been measured using activation methods and the velocity filter SHIP. The data span the region from well below the fusion barrier up to and beyond the energy where limitation by fission competition takes place. The data are shown to be compatible with the concept of complete fusion followed by the statistical decay of the equilibrated compound nucleus. Information on both the fusion probability at and below the fusion threshold and the fissionability of the compound nuclei formed is extracted. The model dependence of the extracted fission barriers is discussed in detail. In analogy to studies involving lighter projectiles, strong correlations between the low-energy nuclear-structure properties of the nuclei and the subbarrier fusion probability are found. A relative shift of the fusion barrier to higher energies, that increases with the number of valence neutrons in the target nuclei, is observed. (orig.)

  14. Detail-enhanced multimodality medical image fusion based on gradient minimization smoothing filter and shearing filter.

    Science.gov (United States)

    Liu, Xingbin; Mei, Wenbo; Du, Huiqian

    2018-02-13

    In this paper, a detail-enhanced multimodality medical image fusion algorithm is proposed by using proposed multi-scale joint decomposition framework (MJDF) and shearing filter (SF). The MJDF constructed with gradient minimization smoothing filter (GMSF) and Gaussian low-pass filter (GLF) is used to decompose source images into low-pass layers, edge layers, and detail layers at multiple scales. In order to highlight the detail information in the fused image, the edge layer and the detail layer in each scale are weighted combined into a detail-enhanced layer. As directional filter is effective in capturing salient information, so SF is applied to the detail-enhanced layer to extract geometrical features and obtain directional coefficients. Visual saliency map-based fusion rule is designed for fusing low-pass layers, and the sum of standard deviation is used as activity level measurement for directional coefficients fusion. The final fusion result is obtained by synthesizing the fused low-pass layers and directional coefficients. Experimental results show that the proposed method with shift-invariance, directional selectivity, and detail-enhanced property is efficient in preserving and enhancing detail information of multimodality medical images. Graphical abstract The detailed implementation of the proposed medical image fusion algorithm.

  15. Fusion and quasi-elastic processes near the Coulomb barrier

    International Nuclear Information System (INIS)

    Abriola, D.

    1987-01-01

    An overview of the fusion phenomenon below Coulomb barrier is presented. The current theoretical descriptions, emphasizing the relations with direct reactions are discussed. The definition and systematic behaviour of the fusion enhancement below the Coulomb barrier are also presented. The role of coupling to surface degrees of freedom, namely permanent deformations of nuclei, inelastic and transfer channels is shown. The importance of studies describing simultaneously quase-elastic processes and fusion are also shown. (M.C.K.) [pt

  16. Effects on nuclear fusion reaction on diffusion and thermal conduction in a magnetoplasma

    International Nuclear Information System (INIS)

    Sakai, Kazuo; Aono, Osamu.

    1976-12-01

    In spite of the well spread belief in the field of irreversible thermodynamics, vectorial phenomena couple thermodynamically with the scalar phenomena. Transport coefficients concerning the diffusion and the thermal conduction across a strong magnetic field are calculated in the presence of the deuteron-triton fusion reaction on the basis of the gas kinetic theory. When the reaction takes place, the diffusion increases and the thermal conduction decreases. Effects of the reaction exceed those of the Coulomb collision as the temperature is high enough. (auth.)

  17. Study of the role of complete fusion in the reaction of 48Ca and 56Fe with cerium and terbium

    International Nuclear Information System (INIS)

    Morrissey, D.J.

    1978-05-01

    48 Ca and 56 Fe beams from the Super HILAC accelerator were used to irradiate thick metal foils of cerium and terbium. Product gamma ray activities were detected offline and individual products were identified by half-life, gamma ray energy and gamma ray abundances. The production cross sections were iteratively fit to charge and mass dispersions to allow correction for parent decay and calculation of mass yields. From the mass yield curves contributions from quasielastic transfer, deep inelastic transfer and complete fusion reaction mechanisms were interred. Complete fusion was made up on contributions from both evaporation residue and fusion-fission products for the 48 Ca induced reactions. However, only fusion-fission products were detected in the 56 Fe induced reactions. Critical angular momenta for fusion were found to be 82 +- 8 h for 48 Ca + 159 Tb and 34 +- 5 h for 56 Fe + 140 Ce, which can be compared with 53 +- 8 h for 12 C + 197 Au (Natowitz, 1970) and 86 +- 5 h for 40 Ar + 165 Ho (Hanappe, 1973). All of these reactions lead to essentially the same compound nucleus and seem to show the dramatic decline in complete fusion for heavy ions larger than 40 Ar. The prediction of this decline was found to be beyond the model calculations of Bass and the critical distance approach of Glas and Mosel

  18. Reaction-rate coefficients, high-energy ions slowing-down, and power balance in a tokamak fusion reactor plasma

    International Nuclear Information System (INIS)

    Tone, Tatsuzo

    1978-07-01

    Described are the reactivity coefficient of D-T fusion reaction, slowing-down processes of deuterons injected with high energy and 3.52 MeV alpha particles generated in D-T reaction, and the power balance in a Tokamak reactor plasma. Most of the results were obtained in the first preliminary design of JAERI Experimental Fusion Reactor (JXFR) driven with stationary neutral beam injection. A manual of numerical computation program ''BALTOK'' developed for the calculations is given in the appendix. (auth.)

  19. Energy dependence of fusion evaporation-residue cross sections in the 28Si+28Si reaction

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Bauer, J.S.; Gosdin, C.H.; Trotter, R.S.; Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D.; Rosner, G.; Chowdhury, P.; Ikezoe, H.; Kuhn, W.; Kolata, J.J.; Hinnefeld, J.D.; Maguire, C.F.; Mateja, J.F.; Prosser, F.W.; Stephans, G.S.F.

    1990-01-01

    Velocity distributions of mass-identified evaporation residues produced in the 28 Si+ 28 Si reaction have been measured at bombarding energies of 174, 215, 240, 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and total cross sections were extracted at all six bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with lower energy data and the predictions of existing models

  20. Application of SSNTDs for measurements of fusion reaction products in high-temperature plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Malinowska, A., E-mail: a.malinowska@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Szydlowski, A.; Malinowski, K. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Scholz, M.; Paduch, M.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion (IPPLM), 00-908 Warsaw (Poland); Jaskola, M.; Korman, A. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2009-10-15

    The paper describes the application of SSNTDs of the PM-355 type to diagnostics of reaction products emitted from high-temperature deuterium plasmas produced in Plasma Focus (PF) facilities. Acceleration processes occurring in plasma lead often to the generation of high-energy ion beams. Such beams induce nuclear reactions and contribute to the emission of fast neutrons, fusion protons and alpha particles from PF discharges with a deuterium gas. Ion measurements are of primary importance for understanding the mechanisms of the physical processes which drive the charged-particle acceleration. The main aim of the present studies was to perform measurements of spatial- and energy-distributions of fusion-reaction protons (about 3 MeV) within a PF facility. Results obtained from energy measurements were compared with the proton-energy spectra computed theoretically. The protons were measured by means of a set of ion pinhole cameras equipped with PM-355 detectors, which were placed at different angles relative to the electrode axis of the PF facility.

  1. Coupled-channels analyses for 9,11Li + 208Pb fusion reactions with multi-neutron transfer couplings

    Science.gov (United States)

    Choi, Ki-Seok; Cheoun, Myung-Ki; So, W. Y.; Hagino, K.; Kim, K. S.

    2018-05-01

    We discuss the role of two-neutron transfer processes in the fusion reaction of the 9,11Li + 208Pb systems. We first analyze the 9Li + 208Pb reaction by taking into account the coupling to the 7Li + 210Pb channel. To this end, we assume that two neutrons are directly transferred to a single effective channel in 210Pb and solve the coupled-channels equations with the two channels. By adjusting the coupling strength and the effective Q-value, we successfully reproduce the experimental fusion cross sections for this system. We then analyze the 11Li + 208Pb reaction in a similar manner, that is, by taking into account three effective channels with 11Li + 208Pb, 9Li + 210Pb, and 7Li + 212Pb partitions. In order to take into account the halo structure of the 11Li nucleus, we construct the potential between 11Li and 208Pb with a double folding procedure, while we employ a Woods-Saxon type potential with the global Akyüz-Winther parameters for the other channels. Our calculation indicates that the multiple two-neutron transfer process plays a crucial role in the 11Li + 208Pb fusion reaction at energies around the Coulomb barrier.

  2. Indirect Study of the 16O+16O Fusion Reaction Toward Stellar Energies by the Trojan Horse Method

    Directory of Open Access Journals (Sweden)

    Hayakawa S.

    2016-01-01

    Full Text Available The 16O+16O fusion reaction is important in terms of the explosive oxygen burning process during late evolution stage of massive stars as well as understanding of the mechanism of low-energy heavy-ion fusion reactions. We aim to determine the excitation function for the most major exit channels, α+28Si and p+31P, toward stellar energies indirectly by the Trojan Horse Method via the 16O(20Ne, α28Siα and 16O(20Ne, p31Pα three-body reactions. We report preliminary results involving reaction identification, and determination of the momentum distribution of α-16O intercluster motion in the projectile 20Ne nucleus.

  3. The controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2014-01-01

    After some generalities on particle physics, and on fusion and fission reactions, the author outlines that the fission reaction is easier to obtain than the fusion reaction, evokes the fusion which takes place in stars, and outlines the difficulty to manage and control this reaction: one of its application is the H bomb. The challenge is therefore to find a way to control this reaction and make it a steady and continuous source of energy. The author then presents the most promising way: the magnetic confinement fusion. He evokes its main issues, the already performed experiments (tokamak), and gives a larger presentation of the ITER project. Then, he evokes another way, the inertial confinement fusion, and the two main experimental installations (National Ignition Facility in Livermore, and the Laser Megajoule in Bordeaux). Finally, he gives a list of benefits and drawbacks of an industrial nuclear fusion

  4. A comparison of the radiological impact of energy production by fission and fusion reactions

    International Nuclear Information System (INIS)

    Rancillac, F.; Despres, A.

    1990-04-01

    The impacts of respectively a light water reactor and a planned fusion reactor, for which tritium-deuterium fusion reactions will act as energy source have been compared. The comparison is made on the basis of a generated capacity of 1 GWe.year, using the following criteria: fuel inventories, radioactive releases, collective effective dose equivalent commitments to the public and the volume of wastes. The accidental risk is not introduced. Fusion reactor parameters are still subject to uncertainties, which prevent accurate quantification of radionuclide releases (tritium apart) from the nuclear plant. Only orders of magnitude extrapolated from values for the NET tokamak are given. Despite these uncertainties, it would seem more interesting, from the dosimetric point of view, to use fusion reactors to produce electricity, although problems of radioactive releases, handling and long-term storage of radioactive waste would remain. Fusion reactors also generate generate high-level wastes with long-term exposure rates that are lower than those of light water reactors [fr

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kai [Department of Oral and Maxillofacial Surgery, The Affiliated Hospital of Qingdao University, Shandong Province (China); The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Song, Yong [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Department of Stomatology, Liu Zhou People' s Hospital, Guangxi (China); Zhao, Xiao-Ping; Shen, Hui; Wang, Meng; Yan, Ting-lin [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Liu, Ke, E-mail: liuke.1999@aliyun.com [Department of Oral and Maxillofacial-Head and Neck oncology, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China); The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Shang, Zheng-jun, E-mail: shangzhengjun@hotmail.com [Department of Oral and Maxillofacial-Head and Neck oncology, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China); The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China)

    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.

  7. Suprathermal fusion reactions in laser-imploded D-T pellets. Applicability to pellet diagnosis and necessity of nuclear data

    International Nuclear Information System (INIS)

    Tabaru, Y.; Nakao, Y.; Kudo, K.; Nakashima, H.

    1995-01-01

    The suprathermal fusion reaction is examined on the basis of coupled transport/hydrodynamic calculation. We also calculate the energy spectrum of neutrons bursting from DT pellet. Because of suprathermal fusion and rapid pellet expansion, these neutrons contain fast components whose maximum energy reachs about 40 MeV. The pellet ρR diagnosis by the detection of suprathermal fusion neutrons is discussed. (author)

  8. Does PEEK/HA Enhance Bone Formation Compared With PEEK in a Sheep Cervical Fusion Model?

    Science.gov (United States)

    Walsh, William R; Pelletier, Matthew H; Bertollo, Nicky; Christou, Chris; Tan, Chris

    2016-11-01

    Polyetheretherketone (PEEK) has a wide range of clinical applications but does not directly bond to bone. Bulk incorporation of osteoconductive materials including hydroxyapatite (HA) into the PEEK matrix is a potential solution to address the formation of a fibrous tissue layer between PEEK and bone and has not been tested. Using in vivo ovine animal models, we asked: (1) Does PEEK-HA improve cortical and cancellous bone ongrowth compared with PEEK? (2) Does PEEK-HA improve bone ongrowth and fusion outcome in a more challenging functional ovine cervical fusion model? The in vivo responses of PEEK-HA Enhanced and PEEK-OPTIMA ® Natural were evaluated for bone ongrowth in the form of dowels implanted in the cancellous and cortical bone of adult sheep and examined at 4 and 12 weeks as well as interbody cervical fusion at 6, 12, and 26 weeks. The bone-implant interface was evaluated with radiographic and histologic endpoints for a qualitative assessment of direct bone contact of an intervening fibrous tissue later. Gamma-irradiated cortical allograft cages were evaluated as well. Incorporating HA into the PEEK matrix resulted in more direct bone apposition as opposed to the fibrous tissue interface with PEEK alone in the bone ongrowth as well as interbody cervical fusions. No adverse reactions were found at the implant-bone interface for either material. Radiography and histology revealed resorption and fracture of the allograft devices in vivo. Incorporating HA into PEEK provides a more favorable environment than PEEK alone for bone ongrowth. Cervical fusion was improved with PEEK-HA compared with PEEK alone as well as allograft bone interbody devices. Improving the bone-implant interface with a PEEK device by incorporating HA may improve interbody fusion results and requires further clinical studies.

  9. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  10. Image enhancement using thermal-visible fusion for human detection

    Science.gov (United States)

    Zaihidee, Ezrinda Mohd; Hawari Ghazali, Kamarul; Zuki Saleh, Mohd

    2017-09-01

    An increased interest in detecting human beings in video surveillance system has emerged in recent years. Multisensory image fusion deserves more research attention due to the capability to improve the visual interpretability of an image. This study proposed fusion techniques for human detection based on multiscale transform using grayscale visual light and infrared images. The samples for this study were taken from online dataset. Both images captured by the two sensors were decomposed into high and low frequency coefficients using Stationary Wavelet Transform (SWT). Hence, the appropriate fusion rule was used to merge the coefficients and finally, the final fused image was obtained by using inverse SWT. From the qualitative and quantitative results, the proposed method is more superior than the two other methods in terms of enhancement of the target region and preservation of details information of the image.

  11. Calculations of Excitation Functions of Some Structural Fusion Materials for ( n, t) Reactions up to 50 MeV Energy

    Science.gov (United States)

    Tel, E.; Durgu, C.; Aktı, N. N.; Okuducu, Ş.

    2010-06-01

    Fusion serves an inexhaustible energy for humankind. 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. Tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So, the working out the systematics of ( n, t) 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. In this study, ( n, t) reactions for some structural fusion materials such as 27Al, 51V, 52Cr, 55Mn, and 56Fe have been investigated. The new calculations on the excitation functions of 27Al( n, t)25Mg, 51V( n, t)49Ti, 52Cr( n, t)50V, 55Mn( n, t)53Cr and 56Fe( n, t)54Mn reactions have been carried out up to 50 MeV incident neutron energy. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model, hybrid model and the cascade exciton model. Equilibrium effects are calculated according to the Weisskopf-Ewing model. Also in the present work, we have calculated ( n, t) reaction cross-sections by using new evaluated semi-empirical formulas developed by Tel et al. at 14-15 MeV energy. The calculated results are discussed and compared with the experimental data taken from the literature.

  12. Some considerations of ''cold fusion'' including the calculation of fusion rates in molecules of hydrogen isotopes

    International Nuclear Information System (INIS)

    Cowley, S.C.; Kulsrud, R.M.

    1989-11-01

    We calculate the fusion reaction rates in molecules of hydrogen isotopes. The rates are calculated analytically (for the first time) as an asymptotic expansion in the ratio of the electron mass to the reduced mass of the nucleii. The fusion rates of the P-D, D-D, and D-T reactions are given for a variable electron mass by a simple analytic formula. However, we do not know any mechanism by which a sufficiently localized electron in solid can have an 'effective mass' large enough to explain the result of Fleischman and Pons (FP). This calculation indicates that P-D rates should exceed D-D rates for D-D fusion rates less than approximately 10 -23 per molecule per second. The D-D fusion rate is enhanced by a factor of 10 5 at 10,000 degree K if the excited vibrational states are populated with a Boltzmann distribution and the rotational excitations suppressed. The suggestion that experimental results could be explained by bombardment of cold deuterons by kilovolt deuterons is shown to be an unlikely from an energetic point of view. 12 refs., 3 figs., 1 tab

  13. Absorption-Fluctuation Theorem for Nuclear Reactions: Brink-Axel, Incomplete Fusion and All That

    International Nuclear Information System (INIS)

    Hussein, M. S.

    2008-01-01

    We discuss the connection between absorption, averages and fluctuations in nuclear reactions. The fluctuations in the entrance channel result in the compound-nucleus Hauser-Feshbach cross section, and the fluctuations in the intermediate channels result in modifications of multistep reaction cross sections, while the fluctuations in the final channel result in hybrid cross sections that can be used to describe incomplete fusion reactions. We discuss the latter in detail and comment on the validity of the assumptions used in the development of the Surrogate method. We also discuss the theory of multistep reactions with regards to intermediate state fluctuations and the energy dependence and non-locality of the intermediate-channel optical potentials

  14. The IGNITEX fusion project

    International Nuclear Information System (INIS)

    Carrera, R.

    1987-01-01

    The author discusses the recently proposed fusion ignition experiment, IGNITEX. He emphasizes the basic ideas of this concept rather than the specific details of the physics and engineering aspects of the experiment. This concept is a good example of the importance of maintaining an adequate balance between the basic scientific progress in fusion physics and the new technologies that are becoming available in order to make fusion work. The objective of the IGNITEX project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. Being able to study this not-yet-produced regime of plasma operation is essential to fusion research. Two years after the fission nuclear reaction was discovered, a non-self-sustained fission reaction was produced in a laboratory, and in one more year a self-sustained reaction was achieved at the University of Chicago. However, after almost forty years of fusion research, a self-sustained fusion reaction has yet not been produced in a laboratory experiment. This fact indicates the greater difficulty of the fusion experiment. Because of the difficulty involved in the production of a self-sustained fusion reaction, it is necessary to propose such an experiment with maximum ignition margins, maximum simplicity, and minimum financial risk

  15. Potential surfaces in symmetric heavy-ion reactions

    International Nuclear Information System (INIS)

    Royer, G.; Piller, C.; Mignen, J.; Raffray, Y.

    1989-01-01

    The entrance channel in symmetric heavy-ion reactions is studied in the liquid-drop model approach including the nuclear proximity energy and allowing ellipsoidal deformations of the colliding nuclei. In the whole mass range a sudden transition occurs from oblate to prolate shapes when the proximity forces become important. This strongly affects the effective moment of inertia. The ellipsoidal deformations reduce the fusion barrier width for light systems and lower the potential barrier height for medium and heavy nuclei. The results are in agreement with the empirical effective barrier shift determined by Aguiar et al for the 58 Ni + 58 Ni, 74 Ge + 74 Ge and 80 Se + 80 Se systems. The sub-barrier fusion enhancement in heavy-ion reactions might be explained by the slowness of the process. Below the static fusion barrier, the reaction time is long; allowing some adiabaticity and deformations of the colliding ions. Above the barrier, the reaction is more sudden and the deformation degree of freedom is frozen

  16. Inertial confinement fusion reaction chamber and power conversion system study. Final report

    International Nuclear Information System (INIS)

    Maya, I.; Schultz, K.R.; Bourque, R.F.

    1985-10-01

    This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO 2 granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO 2 granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs

  17. Comparative studies for different proximity potentials applied to sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.L. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Beihang University, Key Laboratory of Micro-Nano Measurement-Manipulation and Physics (Ministry of Education), Beijing (China); Qu, W.W. [Medical College of Soochow University, School of Radiation Medicine and Protection, Soochow (China); Guo, M.F.; Qian, J.Q. [Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Zhang, H.Q. [China Institute of Atomic Energy, Beijing (China); Wolski, R. [Henryk Niewodniczanski Institute of Nuclear Physics PAS, Cracow (Poland)

    2016-02-15

    Coulomb barrier heights calculated by using 14 different versions of proximity potentials are studied and applied for experimental data of fusion in terms of a recently proposed energy scaling approach. The results show that the descriptions of proximity potentials 77 and 88 for the barrier heights seem to be closest to the values required by the systematics. On the basis of proximity potential 77, the parameterized formulas of the barrier height and radius are obtained. These formulas can calculate the barrier positions and barrier heights reasonably well within the error, respectively. Thus it provides a simple and direct way to calculate the barrier positions and barrier heights for heavy-ion fusion reactions. (orig.)

  18. Cluster expression in fission and fusion in high-dimensional macroscopic-microscopic calculations

    International Nuclear Information System (INIS)

    Iwamoto, Akira; Ichikawa, Takatoshi; Moller, Peter; Sierk, Arnold J.

    2004-01-01

    We discuss the relation between the fission-fusion potential-energy surfaces of very heavy nuclei and the formation process of these nuclei in cold-fusion reactions. In the potential-energy surfaces, we find a pronounced valley structure, with one valley corresponding to the cold-fusion reaction, the other to fission. As the touching point is approached in the cold-fusion entrance channel, an instability towards dynamical deformation of the projectile occurs, which enhances the fusion cross section. These two 'cluster effects' enhance the production of superheavy nuclei in cold-fusion reactions, in addition to the effect of the low compound-system excitation energy in these reactions. Heavy-ion fusion reactions have been used extensively to synthesize heavy elements beyond actinide nuclei. In order to proceed further in this direction, we need to understand the formation process more precisely, not just the decay process. The dynamics of the formation process are considerably more complex than the dynamics necessary to interpret the spontaneous-fission decay of heavy elements. However, before implementing a full dynamical description it is useful to understand the basic properties of the potential-energy landscape encountered in the initial stages of the collision. The collision process and entrance-channel landscape can conveniently be separated into two parts, namely the early-stage separated system before touching and the late-stage composite system after touching. The transition between these two stages is particularly important, but not very well understood until now. To understand better the transition between the two stages we analyze here in detail the potential energy landscape or 'collision surface' of the system both outside and inside the touching configuration of the target and projectile. In Sec. 2, we discuss calculated five-dimensional potential-energy landscapes inside touching and identify major features. In Sec. 3, we present calculated

  19. Effect of breakup on near barrier fusion

    International Nuclear Information System (INIS)

    Dasgupta, M.; Berriman, A.C.; Butt, R.D.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    2000-01-01

    Full text: Unstable neutron-rich nuclei having very weakly bound neutrons exhibit characteristic features such as a neutron halo extending to large radii, and a low energy threshold for breakup. These features may dramatically affect fusion and other reaction processes. It is well accepted that the extended nuclear matter distribution will lead to an enhancement in fusion cross-sections over those for tightly bound nuclei. The effect of couplings to channels which act as doorways to breakup is, however, controversial, with model predictions differing in the relative magnitudes of enhancement and suppression. To investigate the effect on fusion of couplings specific to unstable neutron-rich nuclei, it is necessary to understand (and then predict) the cross-sections expected for their stable counterparts. This requires knowledge of the energy of the average fusion barrier, and information on the couplings. Experimentally all this information can be obtained from precisely measured fusion cross-sections. Such precision measurements of complete fusion cross-sections for 9 Be + 208 Pb and 6 Li, 7 Li + 209 Bi systems have been done at the Australian National University. The distribution of fusion barriers extracted from these data were used to reliably predict the expected fusion cross-sections. Comparison of the theoretical expectations with the experimentally measured cross-sections show conclusively that complete fusion, at above barrier energies, for all three systems is suppressed (by about 30%) compared with the fusion of more tightly bound nuclei. These measurements, in conjunction with incomplete fusion cross-sections, which were also measured, should encourage a complete theoretical description of fusion and breakup

  20. A survey of selected neutron-activation reactions with short-lived products of importance to fusion reactor technology

    International Nuclear Information System (INIS)

    Ward, R.C.; Gomes, I.C.; Smith, D.L.

    1994-11-01

    The status of the cross sections for production of short-lived radioactivities in the intense high-energy neutron fields associated with D-T fusion reactors is investigated. The main concerns relative to these very radioactive isotopes are with radiation damage to sensitive components such as superconducting magnets, the decay-heat problem and the safety of personnel during operation of the facility. The present report surveys the status of nuclear data required to assess these problems. The study is limited to a few high-priority nuclear reactions which appear to be of critical concern in this context. Other reactions of lesser concern are listed but are not treated in the present work. Among the factors that were considered in defining the relevant reactions and setting priorities are: quantities of the elemental materials in a fusion reactor, isotopic abundances within elemental categories, the decay properties of the induced radioactive byproducts, the reaction cross sections, and the nature of the decay radiations. Attention has been focused on radioactive species with half lives in the range from about 1 second to 15 minutes. Available cross-section and reaction-product decay information from the literature has been compiled and included in the report. Uncertainties have been estimated by examining several sets of experimental as well as evaluated data. Comments on the general status of data for various high-priority reactions are offered. On the basis of this investigation, it has been found that the nuclear data are in reasonably good shape for some of the most important reactions but are unacceptable for others. Based on this investigation, the reactions which should be given the greatest attention are: 16 O(n,p) 16 N, 55 Mn(n,p) 55 Cr, 57 Fe(n,p) 57 Mn, 186 W(n,2n) 185m W, and 207 Pb(n,n') 207m Pb. However, the development of fusion power would benefit from an across-the-board refinement in these nuclear data so that a more accurate quantitative

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Low-energy d+d fusion reactions via the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A., E-mail: tumino@lns.infn.it [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Universita degli Studi di Enna ' Kore' , Enna (Italy); Spitaleri, C. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mukhamedzhanov, A.M. [Cyclotron Institute Texas A and M University, College Station, TX (United States); Typel, S. [Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH - Theorie, Darmstadt (Germany); Aliotta, M. [School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland (United Kingdom); Scottish Universities Physics Alliance (United Kingdom); Burjan, V. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Gimenez del Santo, M. [Departamento de Fisica Nuclear, Universitade de Sao Paulo, Sao Paulo (Brazil); Kiss, G.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); ATOMKI, Debrecen (Hungary); Kroha, V.; Hons, Z. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); La Cognata, M.; Lamia, L. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mrazek, J. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Pizzone, R.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Piskor, S. [Nuclear Physics Institute of ASCR, Rez (Czech Republic); Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy)

    2011-06-06

    The bare nucleus S(E) factors for the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions have been measured for the first time via the Trojan Horse Method off the proton in {sup 3}He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4{+-}1.8 MeVb for {sup 3}H+p and 60.1{+-}1.9 MeVb for {sup 3}He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  3. Low-energy d+d fusion reactions via the Trojan Horse Method

    International Nuclear Information System (INIS)

    Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A.M.; Typel, S.; Aliotta, M.; Burjan, V.; Gimenez del Santo, M.; Kiss, G.G.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Mrazek, J.; Pizzone, R.G.; Piskor, S.; Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R.

    2011-01-01

    The bare nucleus S(E) factors for the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions have been measured for the first time via the Trojan Horse Method off the proton in 3 He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3 H+p and 60.1±1.9 MeVb for 3 He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  4. Spin distribution studies: a sensitive probe for in-complete fusion reaction dynamics

    International Nuclear Information System (INIS)

    Singh, Pushpendra P.; Singh, B.P.; Unnati; Sharma, Bhavna; Sharma, Manoj Kumar; Singh, D.; Afzal Ansari, M.; Prasad, R.; Rakesh Kumar; Golda, K.S.; Muralithar, S.; Singh, R.P.; Bhowmik, R.K.; Bhardwaj, H.D.

    2006-01-01

    With the view to get the conclusive information on critical angular momentum involvement for various degrees of incomplete fusion, an in-beam particle-gamma coincidence experiment has been performed in 16 O + 169 Tm system at ≅ 5.6 MeV/nucleon. Spin distributions for different reaction products have been measured by studying the relative population of different levels in a rotational band

  5. Experimental investigation of the confinement of d(3He,p)α and d(d,p)t fusion reaction products in JET

    DEFF Research Database (Denmark)

    Bonheure, Georges; Hult, M.; Gonzalez de Orduna, R.

    2012-01-01

    In ITER, magnetic fusion will explore the burning plasma regime. Because such burning plasma is sustained by its own fusion reactions, alpha particles need to be confined (Hazeltine 2010 Fusion Eng. Des. 7–9 85). New experiments using d(3He,p)α and d(d,p)t fusion reaction products were performed...... in JET. Fusion product loss was measured from MHD-quiescent plasmas with a charged particle activation probe installed at a position opposite to the magnetic field ion gradient drift (see figure 1)—1.77 m above mid-plane—in the ceiling of JET tokamak. This new kind of escaping ion detector (Bonheure et...... al 2008 Fusion Sci. Technol. 53 806) provides for absolutely calibrated measurements. Both the mechanism and the magnitude of the loss are dealt with by this research. Careful analysis shows measured loss is in quantitative agreement with predictions from the classical orbit loss model. However...

  6. Enhancing Health Risk Prediction with Deep Learning on Big Data and Revised Fusion Node Paradigm

    Directory of Open Access Journals (Sweden)

    Hongye Zhong

    2017-01-01

    Full Text Available With recent advances in health systems, the amount of health data is expanding rapidly in various formats. This data originates from many new sources including digital records, mobile devices, and wearable health devices. Big health data offers more opportunities for health data analysis and enhancement of health services via innovative approaches. The objective of this research is to develop a framework to enhance health prediction with the revised fusion node and deep learning paradigms. Fusion node is an information fusion model for constructing prediction systems. Deep learning involves the complex application of machine-learning algorithms, such as Bayesian fusions and neural network, for data extraction and logical inference. Deep learning, combined with information fusion paradigms, can be utilized to provide more comprehensive and reliable predictions from big health data. Based on the proposed framework, an experimental system is developed as an illustration for the framework implementation.

  7. Thermonuclear fusion

    International Nuclear Information System (INIS)

    Weisse, J.

    2000-01-01

    This document takes stock of the two ways of thermonuclear fusion research explored today: magnetic confinement fusion and inertial confinement fusion. The basic physical principles are recalled first: fundamental nuclear reactions, high temperatures, elementary properties of plasmas, ignition criterion, magnetic confinement (charged particle in a uniform magnetic field, confinement and Tokamak principle, heating of magnetized plasmas (ohmic, neutral particles, high frequency waves, other heating means), results obtained so far (scale laws and extrapolation of performances, tritium experiments, ITER project), inertial fusion (hot spot ignition, instabilities, results (Centurion-Halite program, laser experiments). The second part presents the fusion reactor and its associated technologies: principle (tritium production, heat source, neutron protection, tritium generation, materials), magnetic fusion (superconducting magnets, divertor (role, principle, realization), inertial fusion (energy vector, laser adaptation, particle beams, reaction chamber, stresses, chamber concepts (dry and wet walls, liquid walls), targets (fabrication, injection and pointing)). The third chapter concerns the socio-economic aspects of thermonuclear fusion: safety (normal operation and accidents, wastes), costs (costs structure and elementary comparison, ecological impact and external costs). (J.S.)

  8. Muon-catalyzed fusion: A new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  9. Muon-catalyzed fusion: a new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  10. Modelling third harmonic ion cyclotron acceleration of deuterium beams for JET fusion product studies experiments

    DEFF Research Database (Denmark)

    Schneider, M.; Johnson, T.; Dumont, R.

    2016-01-01

    Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 (3He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) of the beam. This scenario generates a fast ion deuterium tail...... enhancing DD and D3He fusion reactions. Modelling and measuring the fast deuterium tail accurately is essential for quantifying the fusion products. This paper presents the modelling of the D distribution function resulting from the NBI+ICRF heating scheme, reinforced by a comparison with dedicated JET fast...

  11. Estimates of fission barrier heights for neutron-deficient Po to Ra nuclei produced in fusion reactions

    Directory of Open Access Journals (Sweden)

    Sagaidak Roman

    2017-01-01

    Full Text Available The cross section data for fission and evaporation residue production in fusion reactions leading to nuclei from Po to Ra have been considered in a systematic way in the framework of the conventional barrier-passing (fusion model coupled with the statistical model. The cross section data obtained in very asymmetric projectile-target combinations can be described within these models rather well with the adjusted model parameters. In particular, one can scale and fix the macroscopic (liquid-drop fission barrier heights (FBHs for nuclei involved in the de-excitation of compound nuclei produced in the reactions. The macroscopic FBHs for nuclei from Po to Ra have been derived in the framework of such analysis and compared with the predictions of various theoretical models.

  12. Complete fusion excitation function for the 16O + natS reaction

    International Nuclear Information System (INIS)

    Wang Sufang; Zheng Jiwen; Liu Guoxing

    1994-01-01

    The complete fusion excitation function for the 16 O + nat S reaction has been measured in the range of 50-75 MeV with a step of 1.0 MeV by using a position sensitive ΔE-E telescope system. The model parameters have been extracted from data analysis. The striking gross structure of the excitation function has been observed. The energies of peaks are at E CM 38,43 and 48 MeV respectively

  13. Cold fusion reaction ignition at cavitation effect on deuterium-containing media

    International Nuclear Information System (INIS)

    Lipson, A.G.; Deryagin, B.V.; Klyuev, V.A.

    1992-01-01

    A possibility to induce 'cold' nuclear fusion reactions in the process of ultrasound cavitation in heavy water is studied. Nonstationary neutron emission is detected under cavitation in D 2 O on titanium vibrator which has the tracks of cavitation erosion (the vibrator ran in D 2 O to 20 hours). Maximum excess over background (12σ) was recorded under cavitation impact on the suspension of LaNi 5 D x dispersed particle in D 2 O

  14. Vaccine-induced anti-HA2 antibodies promote virus fusion and enhance influenza virus respiratory disease.

    Science.gov (United States)

    Khurana, Surender; Loving, Crystal L; Manischewitz, Jody; King, Lisa R; Gauger, Phillip C; Henningson, Jamie; Vincent, Amy L; Golding, Hana

    2013-08-28

    Vaccine-induced disease enhancement has been described in connection with several viral vaccines in animal models and in humans. We investigated a swine model to evaluate mismatched influenza vaccine-associated enhanced respiratory disease (VAERD) after pH1N1 infection. Vaccinating pigs with whole inactivated H1N2 (human-like) virus vaccine (WIV-H1N2) resulted in enhanced pneumonia and disease after pH1N1 infection. WIV-H1N2 immune sera contained high titers of cross-reactive anti-pH1N1 hemagglutinin (HA) antibodies that bound exclusively to the HA2 domain but not to the HA1 globular head. No hemagglutination inhibition titers against pH1N1 (challenge virus) were measured. Epitope mapping using phage display library identified the immunodominant epitope recognized by WIV-H1N2 immune sera as amino acids 32 to 77 of pH1N1-HA2 domain, close to the fusion peptide. These cross-reactive anti-HA2 antibodies enhanced pH1N1 infection of Madin-Darby canine kidney cells by promoting virus membrane fusion activity. The enhanced fusion activity correlated with lung pathology in pigs. This study suggests a role for fusion-enhancing anti-HA2 antibodies in VAERD, in the absence of receptor-blocking virus-neutralizing antibodies. These findings should be considered during the evaluation of universal influenza vaccines designed to elicit HA2 stem-targeting antibodies.

  15. Fusion evaporation residues and the distribution of reaction strength in 16O + 40Ca and 28Si + 28Si reactions

    International Nuclear Information System (INIS)

    Kolata, J.J.; Hinnefeld, J.; Kovar, D.G.

    1985-01-01

    In measurements performed previously at ANL, studying the two entrance channels 16 O + 40 Ca and 28 Si + 28 Si which form the same compound nucleus 56 Ni, it was found that at higher bombarding energies (E/sub Lab/ > 5-7 MeV/nucleon) the distributions of reaction strength was dramatically different. Although the total reaction cross section behaviors for the two entrance channels are similar, the total evaporation residue (ER) cross sections for 28 Si + 28 Si decrease rapidly with increasing bombarding energies and up to the highest energy studied show no evidence for incomplete fusion processes. For 16 O + 40 Ca the ER cross section remains constant at approximately 1 barn with increasing bombarding energy and shows evidence of increasing contributions from incomplete fusion. To better understand this apparent dependence on the mass asymmetry in the entrance channel, coincidence measurements between evaporation residue-like products and heavy ions on the opposite side of the beam were performed for the two systems at E/sub Lab/ = 8 MeV/nucleon

  16. Molecular resonances, fusion reactions and surface transparency of interaction between heavy ions

    International Nuclear Information System (INIS)

    Abe, Yasuhisa.

    1980-01-01

    A review of the Band Crossing Model is given, including recent results on the 16 O + 16 O system. Surface Transparency is discussed in the light of the recent development in our understanding of the fusion reaction mechanisms and by calculating the number of open channels available to direct reactions. The existence of the Molecular Resonance Region is suggested in several systems by the fact that Band Crossing Region overlaps with the Transparent Region. A systematic study predicts molecular resonances in the 14 C + 14 C and 12 C + 14 C systems as prominent as those observed in the 16 O + 16 O and 12 C + 16 O systems

  17. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation.

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

    Science.gov (United States)

    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.

  19. Neutrons and fusion

    International Nuclear Information System (INIS)

    Maynard, C.W.

    1976-01-01

    The production of energy from fusion reactions does not require neutrons in the fundamental sense that they are required in a fission reactor. Nevertheless, the dominant fusion reaction, that between deuterium and tritium, yields a 14 MeV neutron. To contrast a fusion reactor based on this reaction with the fission case, 3 x 10 20 such neutrons produced per gigawatt of power. This is four times as many neutrons as in an equivalent fission reactor and they carry seven times the energy of the fission neutrons. Thus, they dominate the energy recovery problem and create technological problems comparable to the original plasma confinement problem as far as a practical power producing device is concerned. Further contrasts of the fusion and fission cases are presented to establish the general role of neutrons in fusion devices. Details of the energy deposition processes are discussed and those reactions necessary for producing additional tritium are outlined. The relatively high energy flux with its large intensity will activate almost any materials of which the reactor may be composed. This activation is examined from the point of view of decay heat, radiological safety, and long-term storage. In addition, a discussion of the deleterious effects of neutron interactions on materials is given in some detail; this includes the helium and hydrogen producing reactions and displacement rate of the lattice atoms. The various materials that have been proposed for structural purposes, for breeding, reflecting, and moderating neutrons, and for radiation shielding are reviewed from the nuclear standpoint. The specific reactions of interest are taken up for various materials and finally a report is given on the status and prospects of data for fusion studies

  20. Numerical simulation by a random particle method of Deuterium-Tritium fusion reactions in a plasma*

    Directory of Open Access Journals (Sweden)

    Charles Fréderique

    2013-01-01

    Full Text Available We propose and we justify a Monte-Carlo algorithm which solves a spatially homogeneous kinetic equation of Boltzmann type that models the fusion reaction between a deuterium ion and a tritium ion, and giving an α particle and a neutron. The proposed algorithm is validated with the use of explicit solutions of the kinetic model obtained by replacing the fusion cross-section by a Maxwellian cross section. On propose et on justifie un algorithme de type Monte-Carlo permettant de résoudre un modèle cinétique homogène en espace de type Boltzmann modélisant la réaction de fusion entre un ion deutérium et un ion tritium, et donnant une particule α et un neutron. L’algorithme proposé est par ailleurs validé via des solutions explicites du modèle cinétique obtenues en remplaçant la section efficace de fusion par une section efficace maxwellienne.

  1. Data Fusion for Enhanced Aircraft Engine Prognostics and Health Management

    Science.gov (United States)

    Volponi, Al

    2005-01-01

    Aircraft gas-turbine engine data is available from a variety of sources, including on-board sensor measurements, maintenance histories, and component models. An ultimate goal of Propulsion Health Management (PHM) is to maximize the amount of meaningful information that can be extracted from disparate data sources to obtain comprehensive diagnostic and prognostic knowledge regarding the health of the engine. Data fusion is the integration of data or information from multiple sources for the achievement of improved accuracy and more specific inferences than can be obtained from the use of a single sensor alone. The basic tenet underlying the data/ information fusion concept is to leverage all available information to enhance diagnostic visibility, increase diagnostic reliability and reduce the number of diagnostic false alarms. This report describes a basic PHM data fusion architecture being developed in alignment with the NASA C-17 PHM Flight Test program. The challenge of how to maximize the meaningful information extracted from disparate data sources to obtain enhanced diagnostic and prognostic information regarding the health and condition of the engine is the primary goal of this endeavor. To address this challenge, NASA Glenn Research Center, NASA Dryden Flight Research Center, and Pratt & Whitney have formed a team with several small innovative technology companies to plan and conduct a research project in the area of data fusion, as it applies to PHM. Methodologies being developed and evaluated have been drawn from a wide range of areas including artificial intelligence, pattern recognition, statistical estimation, and fuzzy logic. This report will provide a chronology and summary of the work accomplished under this research contract.

  2. Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

    Science.gov (United States)

    Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

    2018-03-01

    In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

  3. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Directory of Open Access Journals (Sweden)

    Jadambaa Khuyagbaatar

    2017-01-01

    Full Text Available The synthesis of superheavy elements beyond oganesson (Og, which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98 forces the use of projectiles heavier than 48Ca (Z = 20, which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to “cold” and “hot” fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  4. The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

    Science.gov (United States)

    Jadambaa, Khuyagbaatar

    2017-11-01

    The synthesis of superheavy elements beyond oganesson (Og), which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98) forces the use of projectiles heavier than 48Ca (Z = 20), which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to "cold" and "hot" fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

  5. Atomic fusion, Gerrard atomic fusion

    International Nuclear Information System (INIS)

    Gerrard, T.H.

    1980-01-01

    In the approach to atomic fusion described here the heat produced in a fusion reaction, which is induced in a chamber by the interaction of laser beams and U.H.F. electromagnetic beams with atom streams, is transferred to a heat exchanger for electricity generation by a coolant flowing through a jacket surrounding the chamber. (U.K.)

  6. Nuclear dynamics in heavy ion induced fusion-fission reactions

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    1992-01-01

    Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

  7. Some fusion perspectives

    International Nuclear Information System (INIS)

    McNally, J.R. Jr.

    1977-01-01

    Some of the concepts of nuclear fusion reactions, advanced fusion fuels, environmental impacts, etc., are explored using the following general outline: I. Principles of Fusion (Nuclear Fuels and Reactions, Lawson Condition, n tau vs T, Nuclear Burn Characteristics); II. Magnetic Mirror Possibilities (the Ion Layer and Electron Layer, Exponential Build-up at MeV energies, Lorentz trapping at GeV energies); III. Pellet Fuel Fusion Prospects (Advanced Pellet Fuel Fusion Prospects, Burn Characteristics and Applications, Excitation-heating Prospects for Runaway Ion Temperatures). Inasmuch as the outline is very skeletal, a significant research and development effort may be in order to evaluate these prospects in more detail and hopefully ''harness the H-bomb'' for peaceful applications, the author concludes. 28 references

  8. Near and sub-barrier fusion studies with radioactive nuclei: an overview

    International Nuclear Information System (INIS)

    Majumdar, Harashit

    2004-01-01

    Full text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

  9. Near and sub-barrier fusion studies with radioactive nuclei: an overview

    International Nuclear Information System (INIS)

    Majumdar, Harashit

    2004-01-01

    Full Text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

  10. Extricate of incomplete fusion reactions at 4-7 MeV/A System:19F+159Tb

    International Nuclear Information System (INIS)

    Unnati; Mandal, S.K.; Yadav, A.; Singh, D.P.; Goswami, S.; Singh, B.P.; Sharma, M.K.

    2015-01-01

    Probing of heavy ion interactions and extricating of incomplete fusion (ICF) reactions at low energy regime is a topic of current interest. The main points of such studies is to explore the effect of various entrance channel parameters, viz., (i) the projectile energy, (ii) the mass asymmetry of interacting partners, and (iii) the input angular momenta imparted into the system. It is also pointed out that a separation of CF (Complete Fusion) from ICF is important for meaningful interpretation towards the splitting of nuclei. Further, considerable efforts are being employed to synthesize super heavy nuclei, the presence of various competing channels may add complexity to the synthesis of super heavy nuclei and obstruct the formation of such nuclei. Although, it is now possible to investigate reaction mechanism involved in formation of such nuclei but experimental studies are limited

  11. Influence of the entrance channel in the fusion reaction 318 MeV 74Ge+74Ge

    International Nuclear Information System (INIS)

    Zhu, L.H.; Cinausero, M.; Angelis, G. de; De Poli, M.; Fioretto, E.; Gadea, A.; Napoli, D.R.; Prete, G.; Lucarelli, F.

    1998-01-01

    Entrance channel effects in the fusion of heavy ions have been studied by using the 74 Ge+ 74 Ge reaction at 318 MeV. The population of the yrast superdeformed band in 144 Gd shows an increase when compared with the results obtained in the more asymmetric 48 Ti+ 100 Mo reaction at 215 MeV. The relative yields of the different evaporation residues produced in the 74 Ge+ 74 Ge and in the 48 Ti+ 100 Mo reactions are very similar, with the exception of the 145,144 Gd residual nuclei (3n and 4n decay channels) which are populated with a larger yield in the symmetric reaction. Statistical model calculations reproduce qualitatively such effect if a fission delay is explicitly taken into account. Effects related to fusion barrier fluctuations seem to be important in determining the spin distributions of the compound nucleus. The spectra of the high energy γ-rays emitted in the 74 Ge+ 74 Ge reaction have been measured as a function of the γ-ray multiplicity as well as in coincidence with selected evaporation residues. They are reproduced by standard statistical model calculations with GDR parameters taken from systematics, demonstrating that, in agreement with dynamical model prediction, the emission of γ-rays from the dinucleus formed in the earlier stage of the collision is unimportant. (orig.)

  12. Fusion and particle transfer around the Coulomb-Barrier in intermediate systems

    International Nuclear Information System (INIS)

    Pascholati, P.R.

    1989-01-01

    The most important characteristics of fusion reactions below and around the Coulomb-barrier are summarized. Experimental fusion cross sections for typical systems are discussed and compared with current formulae obtained from semi-classical and quantum tunneling approaches. The influence of nucleons transfer in the enhancement of the fusion cross section below the Coulomb-barrier is also shown. Sub-barrier fusion cross sections for the systems 35,37 Cl + 58,64 Ni and 33 S + 90,91,92 Zr, and near-barrier cross sections of all important transfer channels have been measured using the XTU-TANDEM at Legnaro, Italy. In 35,37 Cl + 58,64 Ni systems, the motivation further investigated was the influence of the valence proton in the enhancement of the sub-barrier fusion cross section. The data are discussed in comparison with the similar data of 34,36 S + 58,64 Ni with the aim of revealing the influence of coupled proton transfer channels. Calculations were performed using the simplified coupled channel code CCFUS including ''pick-up'' of one and two neutrons and ''stripping'' of two neutrons channels. Signatures of positive Q-values transfer channels coupled to fusion were clearly identified. For the 33 S + 90,91,92 Zr systems taking into account the coupling effects between transfer and fusion and using the semi-classical approach, transfer form-factors were extracted and succesfully employed to described the isotopic effects in fusion enhancement. (Author) [es

  13. Application of the water gas shift reaction to fusion fuel exhaust streams

    International Nuclear Information System (INIS)

    McKay, A.M.; Cheh, C.H.; Glass, R.W.

    1983-10-01

    In a Fusion Fuel Clean Up (FCU) system, impurities will be removed from the fusion reactor exhaust and neutral beam line streams. Tritium in this impurity stream will be recovered and recycled to the fuel stream. In one flowsheet configuration of the Tritium Systems Test Assembly (TSTA), tritium is recovered from a simulated impurity stream via uranium hot metal beds and recycled to an isotope separation system. This study has shown, however, that the catalyzed water gas shift reaction, by which (H,D,T) 2 O and CO are converted to (H,D,T) 2 and CO 2 is a better method of (H,D,T) 2 O reduction than the hot metal beds. Catalytic reactors were designed, built and tested to provide data for the design of a prototype reactor to replace the hot metal beds in the FCU system. The prototype reactor contains only 10 g of catalyst and is expected to last at least 5 years. The reactor is small (1.3 cm OD x 13 cm long), operates at low temperatures (approximately 490 K) and will convert water to hydrogen, at a CO/H 2 O ratio of 1.5, with an efficiency of greater than 98 percent. Results show that the catalytic reactor is very stable even during upset conditions. Wide ranges of flow and a CO/H 2 O ratio variance from 1.3 upward have little effect on the conversion efficiency. Short term high temperature excursions do not affect the catalyst and lower temperatures will simply decrease the reaction rate resulting in lower conversions. The reactor appears to be unaffected by NO 2 , CO 2 , O 2 and N 2 in the feed stream at concentration levels expected in a fusion reactor exhaust stream

  14. Nuclear halo and its related reactions

    International Nuclear Information System (INIS)

    Zhang Huanqiao

    2005-01-01

    nuclear halo in terms of the analytical expressions of the expectation value for the operator r 2 in a finite square-well potential. Nuclear reactions induced by halo and weekly bound nuclei are a topic of current interest. We have measured the complete fusion cross sections of 6 Li+ 208 Pb and found the fusion cross sections above the Coulomb barrier are suppressed due to the breakup effects of weekly bound projectile 6 Li. We have also measured the elastic and quasi-elastic excitation functions of 6,7 Li, 9 Be+ 208 Pb, 209 Ri. From these excitation functions, barrier distributions are extracted and compared with the predictions of the coupled-channels model. It is found that the barrier distributions are somehow broaden and shift to lower energies which may be a signature of the breakup effects of the weekly bound projectiles. Gomes et al. study the behavior of the fusion, breakup, reaction, and elastic scattering of different projectiles on 64 Zn at near and above barrier energies. They found that the elastic (noncapture) breakup cross section is important at energies close to and above the Coulomb barrier and increases the reaction cross sections. In addition, they show that the breakup process at near and below barrier energies is responsible for the vanishing of the usual threshold anomaly of the optical and gives rise to a new type of anomaly. Recently, Newton et al. systematically analyzed the high precision fusion cross sections for Z p Z t p Z t 48 Ca+ 90,96 Zr at the XTU Tandem accelerator facility of the Laboratori Nazionali di Legnaro, Italy. The comparison of experimental 40,48 Ca+ 90,96 Zr fusion data shows that fusion of 40 Ca+ 96 Zr is much enhanced due to the positive Q-values of the transfer channels. The much larger enhancement for the 40 Ca+ 96 Zr as compared to other three systems clearly indicates that neutron transfer with the positive Q-value should play a significant role in sub-barrier fusion. In order to extract the information on the complex

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  16. Enhanced human somatic cell reprogramming efficiency by fusion of the MYC transactivation domain and OCT4

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2017-12-01

    Full Text Available The development of human induced pluripotent stem cells (iPSCs holds great promise for regenerative medicine. However the iPSC induction efficiency is still very low and with lengthy reprogramming process. We utilized the highly potent transactivation domain (TAD of MYC protein to engineer the human OCT4 fusion proteins. Applying the MYC-TAD-OCT4 fusion proteins in mouse iPSC generation leads to shorter reprogramming dynamics, with earlier activation of pluripotent markers in reprogrammed cells than wild type OCT4 (wt-OCT4. Dramatic enhancement of iPSC colony induction efficiency and shortened reprogramming dynamics were observed when these MYC-TAD-OCT4 fusion proteins were used to reprogram primary human cells. The OCT4 fusion proteins induced human iPSCs are pluripotent. We further show that the MYC Box I (MBI is dispensable while both MBII and the linking region between MBI/II are essential for the enhanced reprogramming activity of MYC-TAD-OCT4 fusion protein. Consistent with an enhanced transcription activity, the engineered OCT4 significantly stimulated the expression of genes specifically targeted by OCT4-alone, OCT4/SOX2, and OCT4/SOX2/KLF4 during human iPSC induction, compared with the wt-OCT4. The MYC-TAD-OCT4 fusion proteins we generated will be valuable tools for studying the reprogramming mechanisms and for efficient iPSC generation for humans as well as for other species.

  17. Origin of a maximum of the astrophysical S factor in heavy-ion fusion reactions at deep subbarrier energies

    Science.gov (United States)

    Hagino, K.; Balantekin, A. B.; Lwin, N. W.; Thein, Ei Shwe Zin

    2018-03-01

    The hindrance phenomenon of heavy-ion fusion cross sections at deep subbarrier energies often accompanies a maximum of an astrophysical S factor at a threshold energy for fusion hindrance. We argue that this phenomenon can naturally be explained when the fusion excitation function is fitted with two potentials, with a larger (smaller) logarithmic slope at energies lower (higher) than the threshold energy. This analysis clearly suggests that the astrophysical S factor provides a convenient tool to analyze the deep subbarrier hindrance phenomenon, even though the S factor may have a strong energy dependence for heavy-ion systems unlike that for astrophysical reactions.

  18. Dynamics of the fusion reaction in the dtμ- system

    International Nuclear Information System (INIS)

    Belyaev, V.B.; Revai, J.; Zubarev, A.L.

    1988-08-01

    A dynamical scheme based on the (td,αn) two-channel model is derived for the description of the fusion reaction in the dtμ - system. Special attention is paid to the correct specification of the final states. Several possibilities are pointed out for the systematic improvement of the sudden approximation for the sticking coefficient. It seems to be useful to outline a general formulation of these processes which would allow a clear comparison of existing approaches. The lack of satisfactory agreement between experimental and theoretical values of the sticking coefficient is a further argument in favour of the programme. (R.P.) 10 refs

  19. Dynamical limitations to heavy-ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    In spite of the many attempts to synthesize superheavy elements in recent years, these efforts have not yet been successful. Recent improved theoretical models of heavy-ion fusion reactions suggest that the formation of super-heavy elements is hindered by the dynamics of the process. Several recent experiments lend support to these theories. The necessity of an excess radial velocity (extra push) over the Coulomb barrier in order to induce fusion is observed experimentally as predicted by the theory. So is a new reaction mechanism, called quasi-fission which tend to exhaust the part of the reaction cross section, which would otherwise lead to fusion. The present study shows that the angular distribution of fragments from quasi-fission processes are very sensitive to the occurrence of this reaction mechanism. A slight modification of one parameter in the theory demanded by the observation of quasi-fission for lighter projectiles via the angular distributions, has the consequence of posing even more-stringent limitations on heavy-ion-fusion reactions. This reduces even further the possibility for synthesizing and identifying superheavy elements in heavy-ion-fusion reactions

  20. Fusion reactor wastes

    International Nuclear Information System (INIS)

    Young, J.R.

    1976-01-01

    The fusion reactor currently is being developed as a clean source of electricity with an essentially infinite source of fuel. These reactors are visualized as using a fusion reaction to generate large quantities of high temperature energy which can be used as process heat or for the generation of electricity. The energy would be created primarily as the kinetic energy of neutrons or other reaction products. Neutron energy could be converted to high-temperature heat by moderation and capture of the neutrons. The energy of other reaction products could be converted to high-temperature heat by capture, or directly to electricity by direct conversion electrostatic equipment. An analysis to determine the wastes released as a result of operation of fusion power plants is presented

  1. Towards fusion power

    International Nuclear Information System (INIS)

    Venkataraman, G.

    1975-01-01

    An attempt has been made to present general but broad review of the recent developments in the field of plasma physics and its application to fusion power. The first chapter describes the fusion reactions and fusion power systems. The second chapter deals in detail with production and behaviour of plasma, screening, oscillations, instability, energy losses, temperature effects, etc. Magnetic confinements, including pinch systems, toroidal systems such as Tokamac and stellarator, minor machine, etc. are discussed in detail in chapter III. Laser produced plasma, laser implosion and problems associated with it and future prospects are explained in chapter IV. Chapter V is devoted entirely to the various aspects of hybrid systems. The last chapter throws light on problems of fusion technology, such as plasma heating, vacuum requirements, radiation damage, choice of materials, blanket problems, hazards of fusion reactions, etc. (K.B.)

  2. Process and apparatus for producing nuclear fusion reactions

    International Nuclear Information System (INIS)

    Maglich, B.C.; Nering, J.E.; Mazarakis, M.G.; Miller, R.A.

    1976-01-01

    A process is submitted for the production of fusion reactions between particles of like polarity. This process consists essentially in delimitating a pumped down space comprising a central axis and a central plane arranged radially, and perpendicular to this central axis, in developing in this space a magnetic field the intensity of which decreases when the radial distance increases from the central axis and of which the intensity increases from the central plane, along this central axis. Particles of the same polarity are produced according to a population distribution in which the density of the particles in the greatest vibrational state exceeds the density of the particles in the greatest vibrational state in a normal distribution. These particles are injected near the centre of the magnetic field, by radial injection towards the inside as from the periphery of the space, in the same plane as the central plane [fr

  3. Resonances and fusion in heavy ion reactions: new models and developments

    International Nuclear Information System (INIS)

    Cindro, N.

    1982-01-01

    Several aspects of the problem of the resonant behaviour of heavy-ion induced reactions are discussed. First, the problem is set in its relation to fundamental nuclear physics and our understanding of nuclear structure. It is suggested that, if the resonant behaviour of heavy-ion reactions is indeed due to the presence of particular configurations in the composite systems, these configurations must have a very specific nature which prevents their mixing with the adjacent states or else other conditons (e.g. low level density) should be met. Further on, the problem of resonant behaviour observed in back-angle elastic scattering and in forward-angle reaction data is discussed. Collisions between heavy ions leading to the composite systems 36 Ar and 40 Ca are used to discuss the apparent lack of correlation between these two sets of data. A way to understand it, based on the fragmentation of broad resonances, is suggested. In the third part the relation between structure in the fusion cross section excitation functions and that in reaction channel cross sections is discussed. Finally, in the fourth part, the orbiting-cluster model of heavy-ion resonances is briefly described and its predictions discussed. Based on this model a list is given of colliding heavy-ion systems where resonances are expected. (author)

  4. Nuclear fusion

    International Nuclear Information System (INIS)

    Al-zaelic, M.M.

    2013-01-01

    Nuclear fusion can be relied on to solve the global energy crisis if the process of limiting the heat produced by the fusion reaction (Plasma) is successful. Currently scientists are progressively working on this aspect whereas there are two methods to limit the heat produced by fusion reaction, the two methods are auto-restriction using laser beam and magnetic restriction through the use of magnetic fields and research is carried out to improve these two methods. It is expected that at the end of this century the nuclear fusion energy will play a vital role in overcoming the global energy crisis and for these reasons, acquiring energy through the use of nuclear fusion reactors is one of the most urge nt demands of all mankind at this time. The conclusion given is that the source of fuel for energy production is readily available and inexpensive ( hydrogen atoms) and whole process is free of risks and hazards, especially to general health and the environment . Nuclear fusion importance lies in the fact that energy produced by the process is estimated to be about four to five times the energy produced by nuclear fission. (author)

  5. Dynamics of complete and incomplete fusion of 6,7Li, 15N and 16O with a 209Bi target

    International Nuclear Information System (INIS)

    Gautam, Manjeet Singh; Vinod, K.; Khatri, Hitender

    2017-01-01

    The dynamics of complete and incomplete fusion of 6,7 Li, 15 N and 16 O with a common target ( 209 Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ( 209 Bi) gets suppressed at above barrier energies. In the case of the 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of 6,7 Li + 209 Bi reactions. In contrast to this, the observed fusion dynamics of 15 N + 209 Bi and 16 O + 209 Bi reactions, wherein the collective excitations such as two phonon, three phonon vibrational states contribute

  6. Can 250+ fusions per muon be achieved?

    International Nuclear Information System (INIS)

    Jones, S.E.

    1987-01-01

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

  7. Proximity approach to study fusion probabilities in heavy-ion collisions

    International Nuclear Information System (INIS)

    Raj Kumari

    2013-01-01

    The fusion cross-sections at the sub-barrier energies are found to be enhanced compared to the predictions of the barrier penetration model. The aim is to test Bass 80, Aage Winther (AW) 95, Denisov DP, Proximity 2010 and Skyrme Energy Density Formalism (SEDF) at energies above as well as below barrier height. For the present systematic study, the fusion probabilities for the reactions of 28 Si+ 24,26 Mg 30 Si+ 24 Mg and 28,30 Si+ 58,62 Ni have been calculated

  8. Fusion enhancement at near and sub-barrier energies in {sup 19}O + {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Varinderjit; Vadas, J.; Steinbach, T.K.; Wiggins, B.B.; Hudan, S. [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Souza, R.T. de, E-mail: deSouza@indiana.edu [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Lin, Zidu; Horowitz, C.J. [Department of Physics and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Baby, L.T.; Kuvin, S.A.; Tripathi, Vandana; Wiedenhöver, I. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Umar, A.S. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)

    2017-02-10

    Measuring the fusion excitation function for an isotopic chain of projectile nuclei provides a stringent test of a microscopic description of fusion. We report the first measurement of the fusion excitation function at near-barrier energies for the {sup 19}O + {sup 12}C system. The measured excitation function is compared with the fusion excitation function of {sup 18}O + {sup 12}C. A significant enhancement in the fusion probability of {sup 19}O ions with a {sup 12}C target as compared to {sup 18}O ions is observed. The experimental cross-sections observed at near-barrier energies are compared with a state-of-the-art microscopic model.

  9. Improving iris recognition performance using segmentation, quality enhancement, match score fusion, and indexing.

    Science.gov (United States)

    Vatsa, Mayank; Singh, Richa; Noore, Afzel

    2008-08-01

    This paper proposes algorithms for iris segmentation, quality enhancement, match score fusion, and indexing to improve both the accuracy and the speed of iris recognition. A curve evolution approach is proposed to effectively segment a nonideal iris image using the modified Mumford-Shah functional. Different enhancement algorithms are concurrently applied on the segmented iris image to produce multiple enhanced versions of the iris image. A support-vector-machine-based learning algorithm selects locally enhanced regions from each globally enhanced image and combines these good-quality regions to create a single high-quality iris image. Two distinct features are extracted from the high-quality iris image. The global textural feature is extracted using the 1-D log polar Gabor transform, and the local topological feature is extracted using Euler numbers. An intelligent fusion algorithm combines the textural and topological matching scores to further improve the iris recognition performance and reduce the false rejection rate, whereas an indexing algorithm enables fast and accurate iris identification. The verification and identification performance of the proposed algorithms is validated and compared with other algorithms using the CASIA Version 3, ICE 2005, and UBIRIS iris databases.

  10. MHD deceleration of fusion reaction products

    International Nuclear Information System (INIS)

    Chow, S.; Bohachevsky, I.O.

    1979-04-01

    The feasibility of magnetohydrodynamic (MHD) deceleration of fuel pellet debris ions exiting from an inertial confinement fusion (ICF) reactor cavity is investigated using one-dimensional flow equations. For engineering reasons, induction-type devices are emphasized; their performance characteristics are similar to those of electrode-type decelerators. Results of the analysis presented in this report indicate that MHD decelerators can be designed within conventional magnet technology to not only decelerate the high-energy fusion pellet debris ions but also to produce some net electric power in the process

  11. Direct projectile break up its relation to the astrophysically revelant fusion reactions

    International Nuclear Information System (INIS)

    Bertulani, C.A.; Hussein, M.S.

    1990-05-01

    The break-up into two pieces of weakly bound nuclei passing by the Coulomb field of a large Z nucleus can provide useful information on the inverse fusion reactions which are important for the elemental formation in the stars. However, the nuclear interaction complicates considerably the extraction of such information. A study is made of the contributions of the Coulomb and nuclear interaction to the process, showing when the Coulomb break-up prevails and how a reliable separation of multipolarities can be done. (author)

  12. The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

    Energy Technology Data Exchange (ETDEWEB)

    Harca, I. M. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna, Russia and Faculty of Physics, University of Bucharest - P.O. Box MG 11, RO 77125, Bucharest-Magurele (Romania); Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna (Russian Federation); Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D. [IPN, CNRS/IN2P3, Univ. Paris-Sud, 91405 Orsay (France); Chubarian, G. [Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); Hanappe, F. [Universite Libre de Bruxelles (ULB), Bruxelles (Belgium); Piot, J.; Schmitt, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Trzaska, W. H. [Accelerator Laboratory of University of Jyväskylä (JYFL), Jyväskylä (Finland); Vardaci, E. [Dipartamento di Scienze Fisiche and INFN (INFN-Na), Napoli (Italy)

    2015-02-24

    The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  13. Enhancement of D-T reaction rate due to D-T contact

    International Nuclear Information System (INIS)

    Hitoki, Shigehisa; Ogasawara, Masatada; Aono, Osamu.

    1979-09-01

    The reaction rate that is appropriate for magnetized nonuniform plasma is numerically calculated to investigate the enhancement of the D-T reaction rate. Spatial separation of the guiding center distributions of D and T enhances the reaction rate. Cases of several guiding center configurations are investigated. The largest enhancement is obtained, when both guiding center distributions are delta-functions which are separated by a length that corresponds to the Gamow peak energy. As compared with the case of no separation of D and T, the maximum enhancing factors obtained are 2.3 for total reaction rate and 1.6 for local reaction rate. Cases of the guiding center distributions with finite widths are also investigated. (author)

  14. Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

    Science.gov (United States)

    Giuffrida, L.; Margarone, D.; Cirrone, G. A. P.; Picciotto, A.; Cuttone, G.; Korn, G.

    2016-10-01

    We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [Yoon et al. Applied Physics Letters 105, 223507 (2014)], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

  15. Fusion reaction yield in focused discharges with variable energy and plasma fine structure

    International Nuclear Information System (INIS)

    Bortolotti, A.; Brzosko, J.S.; Chiara, P. De; Kilic, H.; Mezzetti, F.; Nardi, V.; Powell, C.; Wang, J.

    1992-01-01

    The same linear correlation between the distribution parameters (ΔT and Max ΔV) of the radial current density J between electrodes and the fusion reaction yield per pulse, Y, in the plasma focus (PF) pinch was quantitatively determined from different PF machines. Contact prints of current-sheath fragments (CSF) ejected from the pinch are obtained from 2.5-MeV-D + ions. CSF's show the same submillimetric fine structure of the pinch. (author) 3 refs., 2 tabs

  16. Enhanced EDX images by fusion of multimodal SEM images using pansharpening techniques.

    Science.gov (United States)

    Franchi, G; Angulo, J; Moreaud, M; Sorbier, L

    2018-01-01

    The goal of this paper is to explore the potential interest of image fusion in the context of multimodal scanning electron microscope (SEM) imaging. In particular, we aim at merging the backscattered electron images that usually have a high spatial resolution but do not provide enough discriminative information to physically classify the nature of the sample, with energy-dispersive X-ray spectroscopy (EDX) images that have discriminative information but a lower spatial resolution. The produced images are named enhanced EDX. To achieve this goal, we have compared the results obtained with classical pansharpening techniques for image fusion with an original approach tailored for multimodal SEM fusion of information. Quantitative assessment is obtained by means of two SEM images and a simulated dataset produced by a software based on PENELOPE. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  17. Fusion breeder: its potential role and prospects

    International Nuclear Information System (INIS)

    Lee, J.D.

    1981-01-01

    The fusion breeder is a concept that utilizes 14 MeV neutrons from D + T → n(14.1 MeV) + α(3.5 MeV) fusion reactions to produce more fuel than the tritium (T) needed to sustain the fusion process. This excess fuel production capacity is used to produce fissile material (Pu-239 or U-233) for subsequent use in fission reactors. We are concentrating on a class of blankets we call fission suppressed. The blanket is the region surrounding the fusion plasma in which fusion neutrons interact to produce fuel and heat. The fission-suppressed blanket uses non-fission reactions (mainly (n,2n) or (n,n't)) to generate excess neutrons for the production of net fuel. This is in contrast to the fast fission class of blankets which use (n,fiss) reactions to generate excess neutrons. Fusion reactors with fast fission blankets are commony known as fusion-fission hybrids because they combine fusion and fission in the same device

  18. Laser induced photonuclear and fusion-reactions

    International Nuclear Information System (INIS)

    LoDato, V.A.

    1977-01-01

    The energy release from the fusion-fission pellets is demonstrated. It is shown that the coupling of the fusion-fission process is extremely efficient provided one can obtain the proper compression heating. The pellet of an outer core of (Li6D-Li6T) with an inner core of U238 is shown to be an efficient and practical fuel and can be ignited by the present generation of lasers to produce thermonuclear burn. The demonstration of the efficiency for photonuclear and photofission pellets is shown. However no suitable gamma ray source exists at present to initiate these processes. (orig.) [de

  19. Neuraminidase treatment of respiratory syncytial virus-infected cells or virions, but not target cells, enhances cell-cell fusion and infection

    International Nuclear Information System (INIS)

    Barretto, Naina; Hallak, Louay K.; Peeples, Mark E.

    2003-01-01

    Respiratory syncytial virus (RSV) infection of HeLa cells induces fusion, but transient expression of the three viral glycoproteins induces fusion poorly, if at all. We found that neuraminidase treatment of RSV-infected cells to remove sialic acid (SA) increases fusion dramatically and that the same treatment of transiently transfected cells expressing the three viral glycoproteins, or even cells expressing the fusion (F) protein alone, results in easily detectable fusion. Neuraminidase treatment of the effector cells, expressing the viral glycoproteins, enhanced fusion while treatment of the target cells did not. Likewise, infectivity was increased by treating virions with neuraminidase, but not by treating target cells. Reduction of charge repulsion by removal of the negatively charged SA is unlikely to explain this effect, since removal of negative charges from either membrane would reduce charge repulsion. Infection with neuraminidase-treated virus remained heparan-sulfate-dependent, indicating that a novel attachment mechanism is not revealed by SA removal. Interestingly, neuraminidase enhancement of RSV infectivity was less pronounced in a virus expressing both the G and the F glycoproteins, compared to virus expressing only the F glycoprotein, possibly suggesting that the G protein sterically hinders access of the neuraminidase to its fusion-enhancing target

  20. Advanced Fusion Reactors for Space Propulsion and Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, John J.

    2011-06-15

    In recent years the methodology proposed for conversion of light elements into energy via fusion has made steady progress. Scientific studies and engineering efforts in advanced fusion systems designs have introduced some new concepts with unique aspects including consideration of Aneutronic fuels. The plant parameters for harnessing aneutronic fusion appear more exigent than those required for the conventional fusion fuel cycle. However aneutronic fusion propulsion plants for Space deployment will ultimately offer the possibility of enhanced performance from nuclear gain as compared to existing ionic engines as well as providing a clean solution to Planetary Protection considerations and requirements. Proton triggered 11Boron fuel (p- 11B) will produce abundant ion kinetic energy for In-Space vectored thrust. Thus energetic alpha particles' exhaust momentum can be used directly to produce high Isp thrust and also offer possibility of power conversion into electricity. p-11B is an advanced fusion plant fuel with well understood reaction kinematics but will require some new conceptual thinking as to the most effective implementation.

  1. Advanced Fusion Reactors for Space Propulsion and Power Systems

    Science.gov (United States)

    Chapman, John J.

    2011-01-01

    In recent years the methodology proposed for conversion of light elements into energy via fusion has made steady progress. Scientific studies and engineering efforts in advanced fusion systems designs have introduced some new concepts with unique aspects including consideration of Aneutronic fuels. The plant parameters for harnessing aneutronic fusion appear more exigent than those required for the conventional fusion fuel cycle. However aneutronic fusion propulsion plants for Space deployment will ultimately offer the possibility of enhanced performance from nuclear gain as compared to existing ionic engines as well as providing a clean solution to Planetary Protection considerations and requirements. Proton triggered 11Boron fuel (p- 11B) will produce abundant ion kinetic energy for In-Space vectored thrust. Thus energetic alpha particles "exhaust" momentum can be used directly to produce high ISP thrust and also offer possibility of power conversion into electricity. p- 11B is an advanced fusion plant fuel with well understood reaction kinematics but will require some new conceptual thinking as to the most effective implementation.

  2. Reaction and fusion cross sections for 32S on 27Al and 48Ti

    International Nuclear Information System (INIS)

    Porto, F.; Sambataro, S.; Kusterer, K.; Liu Ken Pao; Doukellis, G.; Harney, H.L.

    1981-01-01

    Elastic scattering and evaporation residues have been measured for the system 32 S + 27 Al at Esub(c)sub(.)sub(m)sub(.) = 66.4, 73.2 MeV and 32 S + 48 Ti at Esub(c)sub(.)sub(m)sub(.) = 96.0 MeV. Reaction cross sections have been obtained by use of the optical theorem and are found to be about 60% larger than the fusion cross sections. (orig.)

  3. Muon-catalyzed fusion revisited

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    A negative muon can induce nuclear fusion in the reaction of deuteron and triton nuclei giving a helium nucleus, a neutron and an emerging negative muon. The muon forms a tightlybound deuteron-triton-muon molecule and fusion follows in about 10{sup -12}s. Then the muon is free again to induce further reactions. Thus the muon can serve as a catalyst for nuclear fusion, which can proceed without the need for the high temperatures which are needed in the confinement and inertial fusion schemes. At room temperature, up to 80 fusions per muon have recently been observed at the LAMPF machine at Los Alamos, and it is clear that this number can be exceeded. These and other results were presented at a summer Workshop on Muon-Catalyzed Fusion held in Jackson, Wyoming. Approximately fifty scientists attended from Austria, Canada, India, Italy, Japan, South Africa, West Germany, and the United States. The Workshop itself is symbolic of the revival of interest in this subject.

  4. ALKALI FUSION OF ROSETTA ZIRCON

    International Nuclear Information System (INIS)

    DAHER, A.

    2008-01-01

    The decomposition of Rosetta zircon by fusion with different types of alkalis has been investigated. These alkalis include sodium hydroxide, potassium hydroxide and eutectic mixture of both. The influences of the reaction temperature, zircon to alkalis ratio, fusion time and the stirring of the reactant on the fusion reaction have been evaluated. The obtained results favour the decomposition of zircon with the eutectic alkalis mixture by a decomposition efficiency of 96% obtained at 500 0 C after one hour

  5. Nuclear fusion: power for the next century

    International Nuclear Information System (INIS)

    1980-05-01

    The basis of fusion reactions is outlined, with special reference to deuterium and tritium (from lithium, by neutron reaction) as reactants, and the state of research worldwide is indicated. The problems inherent in fusion reactions are discussed, plasma is defined, and the steps to be taken to generate electricity from controlled nuclear fusion are stated. Methods of plasma heating and plasma confinement are considered, leading to a description of the tokamak plasma confinement system. Devices under construction include the JET (Joint European Torus) Undertaking in the UK. Plans and possibilities for fusion reactors are discussed. (U.K.)

  6. Enhanced SUMOylation of proteins containing a SUMO-interacting motif by SUMO-Ubc9 fusion

    International Nuclear Information System (INIS)

    Kim, Eui Tae; Kim, Kyeong Kyu; Matunis, Mike J.; Ahn, Jin-Hyun

    2009-01-01

    Identifying new targets for SUMO and understanding the function of protein SUMOylation are largely limited by low level of SUMOylation. It was found recently that Ubc9, the SUMO E2 conjugating enzyme, is covalently modified by SUMO at a lysine 14 in the N-terminal alpha helix, and that SUMO-modified Ubc9 has enhanced conjugation activity for certain target proteins containing a SUMO-interacting motif (SIM). Here, we show that, compared to intact Ubc9, the SUMO-Ubc9 fusion protein has higher conjugating activity for SIM-containing targets such as Sp100 and human cytomegalovirus IE2. Assays using an IE2 SIM mutant revealed the requirement of SIM for the enhanced IE2 SUMOylation by SUMO-Ubc9. In pull-down assays with cell extracts, the SUMO-Ubc9 fusion protein bound to more diverse cellular proteins and interacted with some SIM-containing proteins with higher affinities than Ubc9. Therefore, the devised SUMO-Ubc9 fusion will be useful for identifying SIM-containing SUMO targets and producing SUMO-modified proteins.

  7. Plasma nuclear fusion method

    International Nuclear Information System (INIS)

    Yamazaki, Shunpei; Miyanaga, Shoji; Wakaizumi, Kazuhiro; Takemura, Yasuhiko.

    1990-01-01

    Nuclear fusion reactions are attained by plasma gas phase reactions using magnetic fields and microwaves, and the degree of the reactions is controlled. That is, deuterium (D 2 ) is introduced into a plasma container by utilizing the resonance of microwaves capable of generating plasmas at high density higher by more than 10 - 10 3 times as compared with the high frequency and magnetic fields, and an electric energy is applied to convert gaseous D 2 into plasmas and nuclear fusion is conducted. Further, the deuterium ions in the plasmas are attracted to a surface of a material causing nuclear fusion under a negatively biased electric field from the outside (typically represented by Pd or Ti). Then, deuterium nuclei (d) or deuterium ions collide to the surface of the cathode on the side of palladium to conduct nuclear reaction at the surface or the inside (vicinity) thereof. However, a DC bias is applied as an external bias with the side of the palladium being negative. The cold nuclear fusion was demonstrated by placing a neutron counter in the vicinity of the container and confirming neutrons generated there. (I.S.)

  8. First dedicated in-beam X-ray measurement in heavy-ion fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, C. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); RIKEN, Research Group for Superheavy Elements (Japan); Henning, W. [Argonne National Laboratory, Physics Division (United States); RIKEN, Research Group for Superheavy Elements (Japan); Muecher, D.; Gernhaeuser, R.; Hellgartner, S.; Maier, L. [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Morita, K.; Morimoto, K.; Kaji, D.; Wakabayashi, Y.; Baba, H. [RIKEN, Research Group for Superheavy Elements (Japan); Lutter, R. [Ludwig-Maximilians-Universitaet, Muenchen (Germany)

    2016-07-01

    We report on an experiment aiming at in-beam X-ray spectroscopy of heavy and superheavy elements (SHE). The goal is to establish K-X-ray spectroscopy as a sensitive tool to identify SHE produced in fusion reactions. SHE, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. However, various theories predict spontaneous fission as the dominant decay mode for the daughter nuclides. Additionally, half-lives of these elements are expected to increase to values impeding the identification of SHE solely by their decay. The in-beam identification of the characteristic X-rays would precisely allow to identify the charge number of the produced SHE. Experiments were performed at the RIKEN Nishina Centre for Accelerator based Science by using the gas-filled magnet separator GARIS for superheavy element detection. A high-purity, low-energy planar germanium LEGe-detector was adapted to the GARIS system at the target place for the first time in order to measure the element-characteristic, prompt X-ray emission.

  9. Barriers to fusion

    International Nuclear Information System (INIS)

    Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    1999-01-01

    The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

  10. Study of the role of complete fusion in the reaction of /sup 48/Ca and /sup 56/Fe with cerium and terbium. [Cross sections, yield curves, tables

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, D.J.

    1978-05-01

    /sup 48/Ca and /sup 56/Fe beams from the Super HILAC accelerator were used to irradiate thick metal foils of cerium and terbium. Product gamma ray activities were detected offline and individual products were identified by half-life, gamma ray energy and gamma ray abundances. The production cross sections were iteratively fit to charge and mass dispersions to allow correction for parent decay and calculation of mass yields. From the mass yield curves contributions from quasielastic transfer, deep inelastic transfer and complete fusion reaction mechanisms were interred. Complete fusion was made up on contributions from both evaporation residue and fusion-fission products for the /sup 48/Ca induced reactions. However, only fusion-fission products were detected in the /sup 56/Fe induced reactions. Critical angular momenta for fusion were found to be 82 +- 8 h for /sup 48/Ca + /sup 159/Tb and 34 +- 5 h for /sup 56/Fe + /sup 140/Ce, which can be compared with 53 +- 8 h for /sup 12/C + /sup 197/Au (Natowitz, 1970) and 86 +- 5 h for /sup 40/Ar + /sup 165/Ho (Hanappe, 1973). All of these reactions lead to essentially the same compound nucleus and seem to show the dramatic decline in complete fusion for heavy ions larger than /sup 40/Ar. The prediction of this decline was found to be beyond the model calculations of Bass and the critical distance approach of Glas and Mosel.

  11. Fusion, reaction and break-up cross sections of weakly bound projectiles on 64Zn

    International Nuclear Information System (INIS)

    Gomes, P.R.S.; Padron, I.; Rodriguez, M.D.; Marti, G.V.; Anjos, R.M.; Lubian, J.; Veiga, R.; Liguori Neto, R.; Crema, E.; Added, N.; Chamon, L.C.; Fernandez Niello, J.O.; Capurro, O.A.; Pacheco, A.J.; Testoni, J.E.; Abriola, D.; Arazi, A.; Ramirez, M.; Hussein, M.S.

    2004-01-01

    We present new measurements and a general discussion of the behavior of the fusion, break-up and reaction cross sections of different projectiles on the same target 64 Zn, at near and above barrier energies. The projectiles are the tightly bound 16 O, the stable weakly bound 6 Li, 7 Li and 9 Be and the radioactive very weakly bound 6 He nuclei. We also compare the results with the ones for heavier targets

  12. Fusion barrier distributions and fission anisotropies

    International Nuclear Information System (INIS)

    Hinde, D.J.; Morton, C.R.; Dasgupta, M.; Leigh, J.R.; Lestone, J.P.; Lemmon, R.C.; Mein, J.C.; Newton, J.O.; Timmers, H.; Rowley, N.; Kruppa, A.T.

    1995-01-01

    Fusion excitation functions for 16,17 O+ 144 Sm have been measured to high precision. The extracted fusion barrier distributions show a double-peaked structure interpreted in terms of coupling to inelastic collective excitations of the target. The effect of the positive Q-value neutron stripping channel is evident in the reaction with 17 O. Fission and evaporation residue cross-sections and excitation functions have been measured for the reaction of 16 O+ 208 Pb and the fusion barrier distribution and fission anisotropies determined. It is found that the moments of the fusion l-distribution determined from the fusion and fission measurements are in good agreement. ((orig.))

  13. Fusion events

    International Nuclear Information System (INIS)

    Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.

    1998-01-01

    The fusion reactions between low energy heavy ions have a very high cross section. First measurements at energies around 30-40 MeV/nucleon indicated no residue of either complete or incomplete fusion, thus demonstrating the disappearance of this process. This is explained as being due to the high amount o energies transferred to the nucleus, what leads to its total dislocation in light fragments and particles. Exclusive analyses have permitted to mark clearly the presence of fusion processes in heavy systems at energies above 30-40 MeV/nucleon. Among the complete events of the Kr + Au reaction at 60 MeV/nucleon the majority correspond to binary collisions. Nevertheless, for the most considerable energy losses, a class of events do occur for which the detected fragments appears to be emitted from a unique source. These events correspond to an incomplete projectile-target fusion followed by a multifragmentation. Such events were singled out also in the reaction Xe + Sn at 50 MeV/nucleon. For the events in which the energy dissipation was maximal it was possible to isolate an isotropic group of events showing all the characteristics of fusion nuclei. The fusion is said to be incomplete as pre-equilibrium Z = 1 and Z = 2 particles are emitted. The cross section is of the order of 25 mb. Similar conclusions were drown for the systems 36 Ar + 27 Al and 64 Zn + nat Ti. A cross section value of ∼ 20 mb was determined at 55 MeV/nucleon in the first case, while the measurement of evaporation light residues in the last system gave an upper limit of 20-30 mb for the cross section at 50 MeV/nucleon

  14. Incomplete fusion reactions in Ho

    Indian Academy of Sciences (India)

    model [9], promptly emitted particles (PEPs) model [10], exciton model [11], etc. During the past decade a large number of reports have appeared [12–14] showing the occurrence of incomplete fusion at beam energy just above the Coulomb barrier. Recoil range distribution (RRD) measurements are particularly attractive for ...

  15. Energy from inertial fusion

    International Nuclear Information System (INIS)

    1995-03-01

    This book contains 22 articles on inertial fusion energy (IFE) research and development written in the framework of an international collaboration of authors under the guidance of an advisory group on inertial fusion energy set up in 1991 to advise the IAEA. It describes the actual scientific, engineering and technological developments in the field of inertial confinement fusion (ICF). It also identifies ways in which international co-operation in ICF could be stimulated. The book is intended for a large audience and provides an introduction to inertial fusion energy and an overview of the various technologies needed for IFE power plants to be developed. It contains chapters on (i) the fundamentals of IFE; (ii) inertial confinement target physics; (iii) IFE power plant design principles (requirements for power plant drivers, solid state laser drivers, gas laser drivers, heavy ion drivers, and light ion drivers, target fabrication and positioning, reaction chamber systems, power generation and conditioning and radiation control, materials management and target materials recovery), (iv) special design issues (radiation damage in structural materials, induced radioactivity, laser driver- reaction chamber interfaces, ion beam driver-reaction chamber interfaces), (v) inertial fusion energy development strategy, (vi) safety and environmental impact, (vii) economics and other figures of merit; (viii) other uses of inertial fusion (both those involving and not involving implosions); and (ix) international activities. Refs, figs and tabs

  16. A D-D/D-T fusion reaction based neutron generator system for liver tumor BNCT

    International Nuclear Information System (INIS)

    Koivunoro, H.; Lou, T.P.; Leung, K. N.; Reijonen, J.

    2003-01-01

    Boron-neutron capture therapy (BNCT) is an experimental radiation treatment modality used for highly malignant tumor treatments. Prior to irradiation with low energetic neutrons, a 10B compound is located selectively in the tumor cells. The effect of the treatment is based on the high LET radiation released in the 10 B(n,α) 7 Li reaction with thermal neutrons. BNCT has been used experimentally for brain tumor and melanoma treatments. Lately applications of other severe tumor type treatments have been introduced. Results have shown that liver tumors can also be treated by BNCT. At Lawrence Berkeley National Laboratory, various compact neutron generators based on D-D or D-T fusion reactions are being developed. The earlier theoretical studies of the D-D or D-T fusion reaction based neutron generators have shown that the optimal moderator and reflector configuration for brain tumor BNCT can be created. In this work, the applicability of 2.5 MeV neutrons for liver tumor BNCT application was studied. The optimal neutron energy for external liver treatments is not known. Neutron beams of different energies (1eV < E < 100 keV) were simulated and the dose distribution in the liver was calculated with the MCNP simulation code. In order to obtain the optimal neutron energy spectrum with the D-D neutrons, various moderator designs were performed using MCNP simulations. In this article the neutron spectrum and the optimized beam shaping assembly for liver tumor treatments is presented

  17. Nuclear science experiments with a bright neutron source from fusion reactions on the OMEGA Laser System

    Science.gov (United States)

    Forrest, C. J.; Knauer, J. P.; Schroeder, W. U.; Glebov, V. Yu.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Sickles, M.; Stoeckl, C.; Szczepanski, J.

    2018-04-01

    Subnanosecond impulses of 1013 to 1014 neutrons, produced in direct-drive laser inertial confinement fusion implosions, have been used to irradiate deuterated targets at the OMEGA Laser System (Boehly et al., 1997). The target compounds include heavy water (D2O) and deuterated benzene (C6D6). Yields and energy spectra of neutrons from D(n,2n)p to study the breakup reaction have been measured at a forward angle of θlab = 3 .5∘ ± 3.5° with a sensitive, high-dynamic-range neutron time-of-flight spectrometer to infer the double-differential breakup cross section d2 σ/dE d Ω for 14-MeV D-T fusion neutrons.

  18. Possibilities of achieving fusion reaction with a 4{pi} focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Barsanti, G; Barsella, B; Camerini, M; Federighi, U; Musumeci, L; Talini, N [CAMEN., Leghorn (Italy)

    1958-07-01

    The 4{pi} focusing by means of an electromagnetic field is analysed. The following points considered: (a) The general solutions of system for equations of motion of a mass m with charge +e valid for arbitrary initial conditions. This is necessary for the consideration of imperfectly focused primary trajectories, of the effect of collisions in the vicinity of the origin and of ions produced in the neutral gas which diffuses into the reaction chamber. (b) Investigation of the primary ion injection system, of the density of the ions in the chamber and of the energy balance as a matter of principle. (c) The experimental apparatus needed for 4{pi} focusing of deuterons and a sketch of a fusion reactor.

  19. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    Energy Technology Data Exchange (ETDEWEB)

    Chan, C. K.

    1977-07-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H/sub 2/O(l)..-->..Na/sub 2/O(l)+H/sub 2/(g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated.

  20. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    International Nuclear Information System (INIS)

    Chan, C.K.

    1977-01-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H 2 O(l)→Na 2 O(l)+H 2 (g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated

  1. Pycnonuclear fusion rates. [In white dwarf and neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, S.; Koonin, S.E. (California Institute of Technology, Pasadena (USA))

    1990-12-01

    Pycnonuclear fusion processes in an ionic crystal at zero temperature are discussed. Rearrangement effects of the lattice during the fusion process are accounted for exactly in the screening potential by computing the relaxation of the surrounding nuclei. The dynamics of the rearranging ions also generates an increased effective mass that must be used in describing the tunneling of the fusing nuclei. The opposing effects of lattice polarization through enhanced screening and the effective mass results in pycnonuclear reaction rates that are several orders of magnitude smaller than those calculated in the Wigner-Seitz approximation and are roughly equal to those obtained in the static approximation that neglects polarization entirely. 12 refs.

  2. How much laser power can propagate through fusion plasma?

    International Nuclear Information System (INIS)

    Lushnikov, Pavel M; Rose, Harvey A

    2006-01-01

    Propagation of intense laser beams is crucial for inertial confinement fusion, which requires precise beam control to achieve the compression and heating necessary to ignite the fusion reaction. The National Ignition Facility (NIF), where fusion will be attempted, is now under construction. Control of intense beam propagation may be ruined by laser beam self-focusing. We have identified the maximum laser beam power that can propagate through fusion plasma without significant self-focusing and have found excellent agreement with recent experimental data. This maximum is determined by the collective forward stimulated Brillouin scattering instability which suggests a way to increase the maximum power by appropriate choice of plasma composition with implication for NIF designs. Our theory also leads to the prediction of anti-correlation between beam spray and backscatter and therefore raises the possibility of indirect control of backscatter through manipulation of plasma ionization state or acoustic damping. We find a simple expression for laser intensity at onset of enhanced beam angular divergence (beam spray)

  3. Fusion reaction cross-sections using the Wong model within Skyrme energy density based semiclassical extended Thomas Fermi approach

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Raj, E-mail: rajkumarfzr@gmail.com [Department of Physics, Panjab University, Chandigarh-160014 (India); School of Physics and Material Science, Thapar University, Patiala-147004 (India); Sharma, Manoj K. [School of Physics and Material Science, Thapar University, Patiala-147004 (India); Gupta, Raj K. [Department of Physics, Panjab University, Chandigarh-160014 (India)

    2011-11-15

    First, the nuclear proximity potential, obtained by using the semiclassical extended Thomas Fermi (ETF) approach in Skyrme energy density formalism (SEDF), is shown to give more realistic barriers in frozen density approximation, as compared to the sudden approximation. Then, taking advantage of the fact that, in ETF method, different Skyrme forces give different barriers (height, position and curvature), we use the l-summed extended-Wong model of Gupta and collaborators (2009) under frozen densities approximation for calculating the cross-sections, where the Skyrme force is chosen with proper barrier characteristics, not-requiring additional 'barrier modification' effects (lowering or narrowing, etc.), for a best fit to data at sub-barrier energies. The method is applied to capture cross-section data from {sup 48}Ca + {sup 238}U, {sup 244}Pu, and {sup 248}Cm reactions and to fusion-evaporation cross-sections from {sup 58}Ni + {sup 58}Ni, {sup 64}Ni + {sup 64}Ni, and {sup 64}Ni + {sup 100}Mo reactions, with effects of deformations and orientations of nuclei included, wherever required. Interestingly, whereas the capture cross-sections in Ca-induced reactions could be fitted to any force, such as SIII, SV and GSkI, by allowing a small change of couple of units in deduced l{sub max}-values at below-barrier energies, the near-barrier data point of {sup 48}Ca + {sup 248}Cm reaction could not be fitted to l{sub max}-values deduced for below-barrier energies, calling for a check of data. On the other hand, the fusion-evaporation cross-sections in Ni-induced reactions at sub-barrier energies required different Skyrme forces, representing 'modifications of the barrier', for the best fit to data at all incident center-of-mass energies E{sub c.m.}'s, displaying a kind of fusion hindrance at sub-barrier energies. This barrier modification effect is taken into care here by using different Skyrme forces for reactions belonging to different regions of

  4. Fusion reactors - types - problems

    International Nuclear Information System (INIS)

    Schmitter, K.H.

    1979-07-01

    A short account is given of the principles of fusion reactions and of the expected advantages of fusion reactors. Descriptions are presented of various Tokamak experimental devices being developed in a number of countries and of some mirror machines. The technical obstacles to be overcome before a fusion reactor could be self-supporting are discussed. (U.K.)

  5. Material for fusion reactor

    International Nuclear Information System (INIS)

    Abhishek, Anuj; Ranjan, Prem

    2011-01-01

    To make nuclear fusion power a reality, the scientists are working restlessly to find the materials which can confine the power generated by the fusion of two atomic nuclei. A little success in this field has been achieved, though there are still miles to go. Fusion reaction is a special kind of reaction which must occur at very high density and temperature to develop extremely large amount of energy, which is very hard to control and confine within using the present techniques. As a whole it requires the physical condition that rarely exists on the earth to carry out in an efficient manner. As per the growing demand and present scenario of the world energy, scientists are working round the clock to make effective fusion reactions to real. In this paper the work presently going on is considered in this regard. The progress of the Joint European Torus 2010, ITER 2005, HiPER and minor works have been studied to make the paper more object oriented. A detailed study of the technological and material requirement has been discussed in the paper and a possible suggestion is provided to make a contribution in the field of building first ever nuclear fusion reactor

  6. Cluster correlation effects in 12C+12C and 14N+10B fusion-evaporation reactions

    Directory of Open Access Journals (Sweden)

    Morelli L.

    2015-01-01

    Full Text Available The decay of highly excited states of 24Mg is studied in fusion evaporation events completely detected in charge in the reactions 12C+12C and 14N+10B at 95 and 80 MeV incident energy respectively. The comparison of light charged particles measured spectra with statistical model predictions suggests that the dominant reaction mechanism is compound nucleus (CN formation and decay. However, in both reactions, a discrepancy with statistical expectations is found for α particles detected in coincidence with Carbon, Oxigen and Neon residues. The comparison between the two reactions shows that this discrepancy is only partly explained by an entrance channel effect. Evidence for cluster correlations in excited 24Mg CN is suggested by the comparison between the measured and calculated branching ratios for the channels involving α particles.

  7. Heavy ion fusion reactions: comparison among different models

    Energy Technology Data Exchange (ETDEWEB)

    Canto, L F; Carlson, B V; Hussein, M S

    1988-03-01

    A comparison among different ion fusion models is presented. In particular, the multistep aspects of the recently proposed Dinucleus Doorway Model are made explicit and the model is confronted with other compound nucleus limitation models. It is suggested that the latter models provide effective one-step descriptions of heavy ion fusion.

  8. Tumor necrosis factor-α enhanced fusions between oral squamous cell carcinoma cells and endothelial cells via VCAM-1/VLA-4 pathway

    International Nuclear Information System (INIS)

    Song, Kai; Zhu, Fei; Zhang, Han-zhong; Shang, Zheng-jun

    2012-01-01

    Fusion between cancer cells and host cells, including endothelial cells, may strongly modulate the biological behavior of tumors. However, no one is sure about the driving factors and underlying mechanism involved in such fusion. We hypothesized in this study that inflammation, one of the main characteristics in tumor microenvironment, serves as a prominent catalyst for fusion events. Our results showed that oral cancer cells can fuse spontaneously with endothelial cells in co-culture and inflammatory cytokine tumor necrosis factor-α (TNF-α) increased fusion of human umbilical vein endothelium cells and oral cancer cells by up to 3-fold in vitro. Additionally, human oral squamous cell carcinoma cell lines and 35 out of 50 (70%) oral squamous carcinoma specimens express VLA-4, an integrin, previously implicated in fusions between human peripheral blood CD34-positive cells and murine cardiomyocytes. Expression of VCAM-1, a ligand for VLA-4, was evident on vascular endothelium of oral squamous cell carcinoma. Moreover, immunocytochemistry and flow cytometry analysis revealed that expression of VCAM-1 increased obviously in TNF-α-stimulated endothelial cells. Anti-VLA-4 or anti-VCAM-1 treatment can decrease significantly cancer–endothelial adhesion and block such fusion. Collectively, our results suggested that TNF-α could enhance cancer–endothelial cell adhesion and fusion through VCAM-1/VLA-4 pathway. This study provides insights into regulatory mechanism of cancer–endothelial cell fusion, and has important implications for the development of novel therapeutic strategies for prevention of metastasis. -- Highlights: ► Spontaneous oral cancer–endothelial cell fusion. ► TNF-α enhanced cell fusions. ► VCAM-1/VLA-4 expressed in oral cancer. ► TNF-α increased expression of VCAM-1 on endothelial cells. ► VCAM-1/VLA-4 mediated TNF-α-enhanced cell fusions.

  9. Tumor necrosis factor-{alpha} enhanced fusions between oral squamous cell carcinoma cells and endothelial cells via VCAM-1/VLA-4 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kai; Zhu, Fei; Zhang, Han-zhong [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Shang, Zheng-jun, E-mail: shangzhengjun@hotmail.com [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); First Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan (China)

    2012-08-15

    Fusion between cancer cells and host cells, including endothelial cells, may strongly modulate the biological behavior of tumors. However, no one is sure about the driving factors and underlying mechanism involved in such fusion. We hypothesized in this study that inflammation, one of the main characteristics in tumor microenvironment, serves as a prominent catalyst for fusion events. Our results showed that oral cancer cells can fuse spontaneously with endothelial cells in co-culture and inflammatory cytokine tumor necrosis factor-{alpha} (TNF-{alpha}) increased fusion of human umbilical vein endothelium cells and oral cancer cells by up to 3-fold in vitro. Additionally, human oral squamous cell carcinoma cell lines and 35 out of 50 (70%) oral squamous carcinoma specimens express VLA-4, an integrin, previously implicated in fusions between human peripheral blood CD34-positive cells and murine cardiomyocytes. Expression of VCAM-1, a ligand for VLA-4, was evident on vascular endothelium of oral squamous cell carcinoma. Moreover, immunocytochemistry and flow cytometry analysis revealed that expression of VCAM-1 increased obviously in TNF-{alpha}-stimulated endothelial cells. Anti-VLA-4 or anti-VCAM-1 treatment can decrease significantly cancer-endothelial adhesion and block such fusion. Collectively, our results suggested that TNF-{alpha} could enhance cancer-endothelial cell adhesion and fusion through VCAM-1/VLA-4 pathway. This study provides insights into regulatory mechanism of cancer-endothelial cell fusion, and has important implications for the development of novel therapeutic strategies for prevention of metastasis. -- Highlights: Black-Right-Pointing-Pointer Spontaneous oral cancer-endothelial cell fusion. Black-Right-Pointing-Pointer TNF-{alpha} enhanced cell fusions. Black-Right-Pointing-Pointer VCAM-1/VLA-4 expressed in oral cancer. Black-Right-Pointing-Pointer TNF-{alpha} increased expression of VCAM-1 on endothelial cells. Black

  10. The DD Cold Fusion-Transmutation Connection

    Science.gov (United States)

    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.

  11. Controlled Nuclear Fusion.

    Science.gov (United States)

    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…

  12. Sensitivity of fusion and quasi-elastic barrier distributions of {sub 16}O+{sub 144}Sm reaction on the coupling radius parameter

    Energy Technology Data Exchange (ETDEWEB)

    Zamrun, Muhammad; Usman, Ida; Variani, Viska Inda [Department of Physics, Haluoleo University, Kendari, Sulawesi Tengagra, 93232 (Indonesia); Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05

    We study the heavy-ion collision at sub-barrier energies of {sub 16}O+{sub 144}Sm system using full order coupled-channels formalism. We especially investigate the sensitivity of fusion and quasi-elastic barrier distributions for this system on the coupling radius parameter. We found that the coupled-channels calculations of the fusion and the quasi-elastic barrier distributions are sensitive to the coupling radius for this reaction in contrast to the fusion and quasi-elastic cross section. Our study indicates that the larger coupling radius, i.e., r{sub coup}=1.20, is required by the experimental quasi-elastic barrier distribution. However, the experimental fusion barrier distribution compulsory the small value, i.e., r{sub coup}=1.06.

  13. Theoretical model of the probability of fusion between deuterons within deformed lattices with microcracks at room temperature

    International Nuclear Information System (INIS)

    Frisone, Fulvio

    2006-01-01

    In this work we wish to demonstrate that a reaction path as the following dislocations, deformations due to thermodynamic stress and, finally, microcrack occurrence, can enhance the process of fusion of the deuterons introduced into the lattice by deuterium loading (F. Frisone, Can variations in temperature influence deuteron interaction within crystalline lattices?, Nuovo Cimento D, 18, 1279 (1996)). In fact, calculating the rate of deuteron-plasmon-deuteron fusion within a microcrack, showed, together with an enhancement of the tunneling effect, an increase of at least 2 - 3 orders of magnitude compared to the probability of fusion on the no deformed lattice. In fact, strong electric fields can take place in the microcrack and the deuterons are accelerated to the energy which is enough for the D-D tunnelling (M. Rabinowitz, High temperature superconductivity and cold fusion, Mod. Phys, Lett. B, 4, 233 (1990); J. Price Hirt and J. Lothe, Theory of Dislocation (McGraw Hill); Z. Phys., 457, 156 (1960)). These phenomena open the way to the theoretical hypothesis that a kind of chain reaction, catalyzed by the microcracks produced in the structure as a result of deuterium loading, can favour tho process of deuteron-plasmon fusion (N. W. Ashcroft and N. D. Mermin (Eds.), Solid State Physics, Chapter 25 (Saunders College, Philadelphia, 1972, pp. 492-509)

  14. On experimental determination of characteristics of nuclear fusion reactions from mu-molecular resonance states

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Pen'kov, F.M.

    1997-01-01

    Charge-nonsymmetrical deuterium-helium muon complexes (dμHe) are studied. A method is proposed for experimentally determining the rates of nuclear fusion reactions in dμHe molecules in the J=1 and J=0 states (J is the orbital moment of the system) and the partial rates for radiative decay of these complexes in these states. Experiments are supposed to be carried out at meson factories with gaseous and cryogenic targets filled with a mixture of deuterium and helium

  15. Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium

    Directory of Open Access Journals (Sweden)

    Ma YF

    2013-06-01

    amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion. Furthermore, the fluid liposomal encapsulated tobramycin was prepared, and the bactericidal effect occurred more quickly when bacteria were cultured with liposomal encapsulated tobramycin. Conclusion: The bactericidal potency of fluid liposomes is dramatically enhanced with respect to fusion ability when the fusogenic lipid, DOPE, is included. Regardless of changes in liposome composition, fluid liposomes-bacterium fusion is universally enhanced by calcium ions. The information obtained in this study will increase our understanding of fluid liposomal action mechanisms, and help in optimizing the new generation of fluid liposomal formulations for the treatment of pulmonary bacterial infections. Keywords: liposomes, fusion, bacteria, Pseudomonas aeruginosa, lipid composition

  16. Nuclear physics for nuclear fusion

    International Nuclear Information System (INIS)

    Li Xingzhong; Liu Bin; Wei Qingming; Ren Xianzhe

    2004-01-01

    The D-T fusion cross-section is calculated using quantum mechanics with the model of square nuclear potential well and Coulomb potential barrier. The agreement between ENDF data and the theoretically calculated results is well in the range of 0.2-280 keV. It shows that the application of Breit-Wigner formula is not suitable for the case of the light nuclei fusion reaction. When this model is applied to the nuclear reaction between the charged particles confined in a lattice, it explains the 'abnormal phenomena'. It implies a prospect of nuclear fusion energy without strong nuclear radiations

  17. Nuclear fusion power

    International Nuclear Information System (INIS)

    Dinghee, D.A.

    1983-01-01

    In this chapter, fusion is compared with other inexhaustible energy sources. Research is currently being conducted both within and outside the USA. The current confinement principles of thermonuclear reactions are reveiwed with the discussion of economics mainly focusing on the magnetic confinement concepts. Environmental, health and safety factors are of great concern to the public and measures are being taken to address them. The magnetic fusion program logic and the inertial fusion program logic are compared

  18. Controlled thermonuclear fusion

    CERN Document Server

    Bobin, Jean Louis

    2014-01-01

    The book is a presentation of the basic principles and main achievements in the field of nuclear fusion. It encompasses both magnetic and inertial confinements plus a few exotic mechanisms for nuclear fusion. The state-of-the-art regarding thermonuclear reactions, hot plasmas, tokamaks, laser-driven compression and future reactors is given.

  19. Investigation of fission properties and evaporation residue measurement in the reactions using 238U target nucleus

    Directory of Open Access Journals (Sweden)

    Saro S.

    2011-10-01

    Full Text Available Fragment mass distributions for fission after full momentum transfer were measured in the reactions of 30Si,34,36 S,31P,40Ar + 238U at bombarding energies around the Coulomb barrier. Mass distributions change significantly as a function of incident beam energy. The asymmetric fission probability increases at sub-barrier energy. The phenomenon is interpreted as an enhanced quasifission probability owing to orientation effects on fusion and/or quasifission. The evaporation residue (ER cross sections were measured in the reactions of 30Si + 238U and 34S + 238U to obtain information on fusion. In the latter reaction, significant suppression of fusion was implied. This suggests that fission events different from compound nucleus are included in the masssymmetric fragments. The results are supported by a model calculation based on a dynamical calculation using Langevin equation, in which the mass distribution for fusion-fission and quasifission fragments are separately determined.

  20. FENDL/C-1.0. Charged-particle reaction data library for fusion applications Version 1.0 of November 1991. Summary documentation

    International Nuclear Information System (INIS)

    Pashchenko, A.B.

    1995-01-01

    This document describes the FENDL/C-1.0 charged-particle reaction data library which is a sublibrary of FENDL, the evaluated nuclear data library for fusion applications. This file contains evaluated data in ENDF-6 format for the D(d,n), D(d,p), T(d,n), T(t,2n), He-3(d,p) reactions. The processed information, i.e. Maxwellian-averaged reaction rates, and related quantities, calculated from reaction cross-sections, are also included. The data are available from the Nuclear Data Section online via INTERNET by FTP command, or on magnetic tape upon request. (author). 1 tab

  1. Dynamical limitations to heavy ion fusion

    International Nuclear Information System (INIS)

    Back, B.B.

    1983-01-01

    Dynamical limitations to heavy ion fusion reaction are considered. The experimental signatures and the importance of a quasi-fission process are examined. The anaular distributions of fission fragments for the 32 S+ 208 Pb and 16 O+ 238 U systems are presented. It is shown that the observations of quasi-fission for even rather ''light'' heavy ions poeess severe limitations on the fusion process. This result may consequently be responsible for the lack of success of the search for super heavy elements in heavy ion fusion reactions

  2. Fusion barriers in heavy ion collisions

    International Nuclear Information System (INIS)

    Zhu Long; Su Jun; Xie Wenjie; Guo Chenchen; Zhang Donghong; Zhang Fengshou

    2014-01-01

    Study of fusion barrier is very important for people to better understand fusion reactions. In this paper the Improved Isospin-dependent Quantum Molecular Dynamics (ImIQMD) model is introduced firstly. Then the shell correction effects, energy dependence, isospin effects and orientation effects of fusion barrier are studied. The fusion barriers for the fusion reactions "4"0Ca + "4"0Ca, "4"8Ca + "2"0"8Pb, "4"8Ca + "2"0"4Pb and "1"6O + "1"5"4Sm are extracted. The negative shell correction energies lower potential barriers of a certain reaction. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier are also discussed for the system "1"6O + "1"5"4Sm. (authors)

  3. Multisensor data fusion for enhanced respiratory rate estimation in thermal videos.

    Science.gov (United States)

    Pereira, Carina B; Xinchi Yu; Blazek, Vladimir; Venema, Boudewijn; Leonhardt, Steffen

    2016-08-01

    Scientific studies have demonstrated that an atypical respiratory rate (RR) is frequently one of the earliest and major indicators of physiological distress. However, it is also described in the literature as "the neglected vital parameter", mainly due to shortcomings of clinical available monitoring techniques, which require attachment of sensors to the patient's body. The current paper introduces a novel approach that uses multisensor data fusion for an enhanced RR estimation in thermal videos. It considers not only the temperature variation around nostrils and mouth, but the upward and downward movement of both shoulders. In order to analyze the performance of our approach, two experiments were carried out on five healthy candidates. While during phase A, the subjects breathed normally, during phase B they simulated different breathing patterns. Thoracic effort was the gold standard elected to validate our algorithm. Our results show an excellent agreement between infrared thermography (IRT) and ground truth. While in phase A a mean correlation of 0.983 and a root-mean-square error of 0.240 bpm (breaths per minute) was obtained, in phase B they hovered around 0.995 and 0.890 bpm, respectively. In sum, IRT may be a promising clinical alternative to conventional sensors. Additionally, multisensor data fusion contributes to an enhancement of RR estimation and robustness.

  4. Ecotropic murine leukemia virus-induced fusion of murine cells

    International Nuclear Information System (INIS)

    Pinter, A.; Chen, T.; Lowy, A.; Cortez, N.G.; Silagi, S.

    1986-01-01

    Extensive fusion occurs upon cocultivation of murine fibroblasts producing ecotropic murine leukemia viruses (MuLVs) with a large variety of murine cell lines in the presence of the polyene antibiotic amphotericin B, the active component of the antifungal agent Fungizone. The resulting polykaryocytes contain nuclei from both infected and uninfected cells, as evidenced by autoradiographic labeling experiments in which one or the other parent cell type was separately labeled with [ 3 H]thymidine and fused with an unlabeled parent. This cell fusion specifically requires the presence of an ecotropic MuLV-producing parent and is not observed for cells producing xenotropic, amphotropic, or dualtropic viruses. Mouse cells infected with nonecotropic viruses retain their sensitivity toward fusion, whereas infection with ecotropic viruses abrogates the fusion of these cells upon cocultivation with other ecotropic MuLV-producing cells. Nonmurine cells lacking the ecotropic gp70 receptor are not fused under similar conditions. Fusion is effectively inhibited by monospecific antisera to gp70, but not by antisera to p15(E), and studies with monoclonal antibodies identify distinct amino- and carboxy-terminal gp70 regions which play a role in the fusion reaction. The enhanced fusion which occurs in the presence of amphotericin B provides a rapid and sensitive assay for the expression of ecotropic MuLVs and should facilitate further mechanistic studies of MuLV-induced fusion of murine cells

  5. ENDF/B-VI nuclear data evaluations for fusion applications

    International Nuclear Information System (INIS)

    Dunford, C.L.; Larson, D.C.; Young, P.G.

    1988-01-01

    The next release of the ENDF/B data library planned for 1989 contains improved data evaluations of interest to the fusion neutronics community. New data formats permit inclusion of energy-angle correlated particle emission spectra and recoil nucleus energy spectra. Enhanced formats for covariance information have been developed. Many new isotopic evaluations will lead to improved energy conservation and kerma factor calculations. Improved nuclear model calculations will provide reliable particle emission data where experimental information is sparse. Improved Bayssian fitting codes will provide more accurate evaluations for data rich reactions such as Li(n,nt)α. All of the most important fusion material evaluations contain these new features. 32 refs., 8 figs

  6. Dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a {sup 209}Bi target

    Energy Technology Data Exchange (ETDEWEB)

    Gautam, Manjeet Singh; Vinod, K. [Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Khatri, Hitender [Dr. B.R. Ambedekar Institute of Technology, Department of Physics, Port Blair, Andaman and Nicobar (India)

    2017-10-15

    The dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a common target ({sup 209}Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ({sup 209}Bi) gets suppressed at above barrier energies. In the case of the {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of {sup 6,7}Li + {sup 209}Bi reactions. In contrast to this, the observed fusion dynamics of {sup 15}N + {sup 209}Bi and {sup 16}O + {sup 209}Bi reactions, wherein

  7. Observation of stars produced during cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1992-01-01

    It has been indicated tht multiple-neutron nuclei such as quad-neutrons can be emitted during cold fusion. These multiple-neutrons might bombard the nuclei of materials outside a cold fusion cell to cause nuclear reactions. In this paper, observations of nuclear emulsions that were irradiated during a cold fusion experiment with heavy water and palladium foil are described. Various traces, like stars, showing nuclear reactions caused by the multiple-neutrons have been clearly observed

  8. Muon nuclear fusion and low temperature nuclear fusion

    International Nuclear Information System (INIS)

    Nagamine, Kanetada

    1990-01-01

    Low temperature (or normal temperature) nuclear fusion is one of the phenomena causing nuclear fusion without requiring high temperature. In thermal nuclear fusion, the Coulomb barrier is overcome with the help of thermal energy, but in the low temperature nuclear fusion, the Coulomb barrier is neutralized by the introduction of the particles having larger mass than electrons and negative charges, at this time, if two nuclei can approach to the distance of 10 -13 cm in the neutral state, the occurrence of nuclear fusion reaction is expected. As the mass of the particles is heavier, the neutral region is smaller, and nuclear fusion is easy to occur. The particles to meet this purpose are the electrons within substances and muons. The research on muon nuclear fusion became suddenly active in the latter half of 1970s, the cause of which was the discovery of the fact that the formation of muons occurs resonantly rapidly in D-T and D-D systems. Muons are the unstable elementary particles having the life of 2.2 μs, and they can have positive and negative charges. In the muon catalyzed fusion, the muons with negative charge take part. The principle of the muon catalyzed fusion, its present status and future perspective, and the present status of low temperature nuclear fusion are reported. (K.I.)

  9. Stripping of two protons and one alpha particle transfer reactions for 16 O + A Sm and their influence on the fusion cross section

    International Nuclear Information System (INIS)

    Maciel, A.M.M.; Gomes, P.R.S.

    1995-01-01

    Transfer cross section angular distribution data for the stripping of two protons and one alpha particle are studied for the 16 O + A Sm systems (A=144, 148, 150, 152 and 154), at near barrier energies. A semiclassical formalism is used to derive the corresponding transfer form factors. For only one channel the analysis shows evidences that the transfer reaction mechanism at backward angles - corresponding to small distances, may behave as a multi-step process leading to fusion. Simplified coupled channel calculations including transfer channels are performed for the study of the sub-barrier of these systems. The influence of short distance transfer reactions on the fusion is discussed. (author)

  10. Fusion research principles

    CERN Document Server

    Dolan, Thomas James

    2013-01-01

    Fusion Research, Volume I: Principles provides a general description of the methods and problems of fusion research. The book contains three main parts: Principles, Experiments, and Technology. The Principles part describes the conditions necessary for a fusion reaction, as well as the fundamentals of plasma confinement, heating, and diagnostics. The Experiments part details about forty plasma confinement schemes and experiments. The last part explores various engineering problems associated with reactor design, vacuum and magnet systems, materials, plasma purity, fueling, blankets, neutronics

  11. Overview of safety and environmental issues for inertial fusion energy

    International Nuclear Information System (INIS)

    Piet, S.J.; Brereton, S.J.; Tanaka, S.

    1996-01-01

    This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the first structural wall from fusion pulses. This protective fluid or granular bed also moderates and absorbs most neutrons before they reach the first structural wall. Although the protective fluid activates, most candidate fluids have low activation hazard. Hands-on maintenance seems practical for the driver, target factory, and secondary coolant systems; remote maintenance is likely required for the reaction chamber, primary coolant, and vacuum exhaust cleanup systems. The driver and fuel target facility are well separated from the main reaction chamber

  12. Enhancement Mechanisms of Low Energy Nuclear Reactions

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2005-01-01

    The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy o...

  13. Enhancing Activity for the Oxygen Evolution Reaction

    DEFF Research Database (Denmark)

    Frydendal, Rasmus; Busch, Michael; Halck, Niels Bendtsen

    2014-01-01

    Electrochemical production of hydrogen, facilitated in electrolyzers, holds great promise for energy storage and solar fuel production. A bottleneck in the process is the catalysis of the oxygen evolution reaction, involving the transfer of four electrons. The challenge is that the binding energies...... of all reaction intermediates cannot be optimized individually. However, experimental investigations have shown that drastic improvements can be realized for manganese and cobalt-based oxides if gold is added to the surface or used as substrate. We propose an explanation for these enhancements based...... that the oxygen evolution reaction overpotential decreases by 100–300 mV for manganese oxides and 100 mV for cobalt oxides....

  14. The fusion-fission hybrid

    International Nuclear Information System (INIS)

    Teller, E.

    1985-01-01

    As the history of the development of fusion energy shows, a sustained controlled fusion reaction is much more difficult to produce than rapid uncontrolled release of fusion energy. Currently, the ''magnetic bottle'' technique shows sufficient progress that it might applied for the commercial fuel production of /sup 233/U, suitable for use in fission reactors, by developing a fusion-fission hybrid. Such a device would consist of a fusion chamber core surrounded by a region containing cladded uranium pellets cooled by helium, with lithium salts also present to produce tritium to refuel the fusion process. Successful development of this hybrid might be possible within 10 y, and would provide both experience and funds for further development of controlled fusion energy

  15. Cold nuclear fusion. Germany 2012

    Energy Technology Data Exchange (ETDEWEB)

    Petrescu, Florian Ion

    2012-07-01

    Nuclear fusion is the process by which two or more atomic nuclei join together, or ''fuse'', to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. The binding energy of the resulting nucleus is greater than the binding energy of each of the nuclei that fused to produce it. Fusion is the process that powers active stars. Creating the required conditions for fusion on Earth is very difficult, to the point that it has not been accomplished at any scale for protium, the common light isotope of hydrogen that undergoes natural fusion in stars. In nuclear weapons, some of the energy released by an atomic bomb (fission bomb) is used for compressing and heating a fusion fuel containing heavier isotopes of hydrogen, and also sometimes lithium, to the point of ''ignition''. At this point, the energy released in the fusion reactions is enough to briefly maintain the reaction. Fusion-based nuclear power experiments attempt to create similar conditions using far lesser means, although to date these experiments have failed to maintain conditions needed for ignition long enough for fusion to be a viable commercial power source.

  16. ChimerDB 3.0: an enhanced database for fusion genes from cancer transcriptome and literature data mining.

    Science.gov (United States)

    Lee, Myunggyo; Lee, Kyubum; Yu, Namhee; Jang, Insu; Choi, Ikjung; Kim, Pora; Jang, Ye Eun; Kim, Byounggun; Kim, Sunkyu; Lee, Byungwook; Kang, Jaewoo; Lee, Sanghyuk

    2017-01-04

    Fusion gene is an important class of therapeutic targets and prognostic markers in cancer. ChimerDB is a comprehensive database of fusion genes encompassing analysis of deep sequencing data and manual curations. In this update, the database coverage was enhanced considerably by adding two new modules of The Cancer Genome Atlas (TCGA) RNA-Seq analysis and PubMed abstract mining. ChimerDB 3.0 is composed of three modules of ChimerKB, ChimerPub and ChimerSeq. ChimerKB represents a knowledgebase including 1066 fusion genes with manual curation that were compiled from public resources of fusion genes with experimental evidences. ChimerPub includes 2767 fusion genes obtained from text mining of PubMed abstracts. ChimerSeq module is designed to archive the fusion candidates from deep sequencing data. Importantly, we have analyzed RNA-Seq data of the TCGA project covering 4569 patients in 23 cancer types using two reliable programs of FusionScan and TopHat-Fusion. The new user interface supports diverse search options and graphic representation of fusion gene structure. ChimerDB 3.0 is available at http://ercsb.ewha.ac.kr/fusiongene/. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Liquid-drop model description of heavy ion fusion at sub-barrier energies

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Barbosa, V C; Canto, L F; Donangelo, R

    1987-10-05

    The enhancement of the heavy ion fusion cross section at sub-barrier energies is studied in the liquid-drop model approach. The shape of the system is described by two spheres smoothly connected by a neck, and the kinetic and potential energies are calculated within this parametrization. Underbarrier fusion cross sections for symmetric projectile-target combinations are calculated in the WKB approximation and a comparison with the available data is made. The agreement is quite satisfactory, except for those systems in which the reaction is strongly affected by the details of the nuclear structure of the collision partners.

  18. Measurements of fusion cross section for 12C +63,65 Cu systems

    International Nuclear Information System (INIS)

    Rocha, C.A. da.

    1987-01-01

    Cross-section measurements for nuclear fusion in the 12 C+ 63.65 Cu system, at 12 C energy range from 0.9 to 1.8 times the Coulomb barrier are presented. In order to detect and to obtain the mass identification of the evaporation residues following the fusion process, the time of flight method was adopted in conjunction with an eletrostatic deflector capable of separating the evaporation residues from the beam particles. The limitation and advantadges of this method of measurement are discussed. The excitation functions were analysed using the unidimensional barrier penetration model with different nuclear potentials. Theoretical fusion cross-section values obtained from this analysis were systematically smaller than our measured values, in the energy region below the Coulomb barrier. In order to discover which channel enhances the fusion cross-section in this region, a coupled channel calculation was performed, with the CCFUS code. The experimental data for the above reactions were compared with the systems 16.18 O+ 63.65 Cu, measured by our group. In this comparison, it was noted that the systems 12 C+ 63.65 Cu, have greater fusion cross section below the Coulomb barrier. The comparison of velocity spectra of the evaporated residues for the two systems shows that 12 C+ 63 Cu has a strong reaction channel that was not present in the 12 C+ 65 Cu system. (author) [pt

  19. Fusion - 2050 perspective (in Polish)

    CERN Document Server

    Romaniuk, R S

    2013-01-01

    The results of strongly exothermic reaction of thermonuclear fusion between nuclei of deuterium and tritium are: helium nuclei and neutrons, plus considerable kinetic energy of neutrons of over 14 MeV. DT nuclides synthesis reaction is probably not the most favorable one for energy production, but is the most advanced technologically. More efficient would be possibly aneutronic fusion. The EU by its EURATOM agenda prepared a Road Map for research and implementation of Fusion as a commercial method of thermonuclear energy generation in the time horizon of 2050.The milestones on this road are tokomak experiments JET, ITER and DEMO, and neutron experiment IFMIF. There is a hope, that by engagement of the national government, and all research and technical fusion communities, part of this Road Map may be realized in Poland. The infrastructure build for fusion experiments may be also used for material engineering research, chemistry, biomedical, associated with environment protection, power engineering, security, ...

  20. Dynamical Dipole and Equation of State in N/Z Asymmetric Fusion Reactions

    Directory of Open Access Journals (Sweden)

    Giaz Agnese

    2014-03-01

    Full Text Available In heavy ion reactions, in the case of N/Z asymmetry between projectile and target, the process leading to complete fusion is expected to produce pre-equilibrium dipole γ-ray emission. It is generated during the charge equilibration process and it is known as Dynamical Dipole. A new measurement of the dynamical dipole emission was performed by studying 16O + 116Sn at 12 MeV/u. These data, together with those measured at 8.1 MeV/u and 15.6 MeV/u for the same reaction, provide the dependence on the Dynamical Dipole total emission yield with beam energy and they can be compared with theoretical expectations. The experimental results show a weak increase of the Dynamical Dipole total yield with beam energies and are in agreement with the prediction of a theoretical model based on the Boltzmann–Nordheim–Vlasov (BNV approach. The measured trend with beam energy does not confirm the rise and fall behavior previously reported for the same fused compound but with a much higher dipole moment.

  1. Consistent analysis of peripheral reaction channels and fusion for the 16,18O+58Ni systems

    International Nuclear Information System (INIS)

    Alves, J.J.S.; Gomes, P.R.S.; Lubian, J.; Chamon, L.C.; Pereira, D.; Anjos, R.M.; Rossi, E.S.; Silva, C.P.; Alvarez, M.A.G.; Nobre, G.P.A.; Gasques, L.R.

    2005-01-01

    We have measured elastic scattering and peripheral reaction channel cross sections for the 16,18 O+ 58 Ni systems at ELab=46 MeV. The data were analyzed through extensive coupled-channel calculations. It was investigated the consistency of the present analysis with a previous one at sub-barrier energies. Experimental fusion cross sections for these systems are also compared with the corresponding predictions of the coupled-channel calculations

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. Aggregation and fusion of low-density lipoproteins in vivo and in vitro

    Science.gov (United States)

    Gursky, Olga

    2014-01-01

    Low-density lipoproteins (LDLs, also known as ‘bad cholesterol’) are the major carriers of circulating cholesterol and the main causative risk factor of atherosclerosis. Plasma LDLs are 20- to 25-nm nanoparticles containing a core of cholesterol esters surrounded by a phospholipid monolayer and a single copy of apolipoprotein B (550 kDa). An early sign of atherosclerosis is the accumulation of LDL-derived lipid droplets in the arterial wall. According to the widely accepted ‘response-to-retention hypothesis’, LDL binding to the extracellular matrix proteoglycans in the arterial intima induces hydrolytic and oxidative modifications that promote LDL aggregation and fusion. This enhances LDL uptake by the arterial macrophages and triggers a cascade of pathogenic responses that culminate in the development of atherosclerotic lesions. Hence, LDL aggregation, fusion, and lipid droplet formation are important early steps in atherogenesis. In vitro, a variety of enzymatic and nonenzymatic modifications of LDL can induce these reactions and thereby provide useful models for their detailed analysis. Here, we summarize current knowledge of the in vivo and in vitro modifications of LDLs leading to their aggregation, fusion, and lipid droplet formation; outline the techniques used to study these reactions; and propose a molecular mechanism that underlies these pro-atherogenic processes. Such knowledge is essential in identifying endogenous and exogenous factors that can promote or prevent LDL aggregation and fusion in vivo and to help establish new potential therapeutic targets to decelerate or even block these pathogenic reactions. PMID:25197325

  4. Advanced fusion reactor

    International Nuclear Information System (INIS)

    Tomita, Yukihiro

    2003-01-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p- 6 Li and p- 11 B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D- 3 He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D- 3 He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of 3 He per a year. On the other hand, 1 million tons of 3 He is estimated to be in the moon. The 3 He of about 10 23 kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  5. Muon catalyzed fusion under compressive conditions

    International Nuclear Information System (INIS)

    Cripps, G.; Goel, B.; Harms, A.A.

    1991-01-01

    The viability of a symbiotic combination of Muon Catalyzed Fusion (μCF) and high density generation processes has been investigated. The muon catalyzed fusion reaction rates are formulated in the temperature and density range found under moderate compressive conditions. Simplified energy gain and power balance calculations indicate that significant energy gain occurs only if standard type deuterium-tritium (dt) fusion is ignited. A computer simulation of the hydrodynamics and fusion kinetics of a spherical deuterium-tritium pellet implosion including muons is performed. Using the muon catalyzed fusion reaction rates formulated and under ideal conditions, the pellet ignites (and thus has a significant energy gain) only if the initial muon concentration is approximately 10 17 cm -3 . The muons need to be delivered to the pellet within a very short-time (≅ 1 ns). The muon pulse required in order to make the high density and temperature muon catalyzed fusion scheme viable is beyond the present technology for muon production. (orig.) [de

  6. Reduction methodology for reaction cross sections induced by weakly bound nuclei

    International Nuclear Information System (INIS)

    Deshmukh, N.N.; Mukherjee, S.; Appannababu, S.; Guimaraees, V.; Lubian, J.; Gomes, P.R.S.

    2009-01-01

    The interest in nuclear reactions with weakly bound nuclei has increased considerably along the last decade. Several experiments with stable and unstable projectiles have been performed and a variety of theoretical approaches have been developed. In particular, fusion and breakup reactions induced by such projectiles have been the object of several studies. Owing to the weak binding of the projectile, the breakup cross section may be quite large and coupling with the breakup channel can strongly affect the fusion cross section at near barrier energies. This influence stems from two effects, one of a static and the other of a dynamic nature, which are, however, not easy to be disentangled. The static effect results from the more diffuse density of the weakly bound nuclei, as compared with a strongly bound one. The contribution from weakly bound nucleons to the nuclear density extends further out and this gives rise to a lower and thicker potential barrier. There is general understanding that this static effect enhances the fusion cross section at near barrier energies. On the other hand, there is the dynamic effect corresponding to the coupling with the breakup channel. It is well known that the coupling with a finite number of bound channels enhances the sub-barrier fusion cross section. However, the effect of coupling to channels in the continuum (breakup) is controversial. In first place, one should have in mind that there are different fusion processes in collisions of weakly bound projectiles. One of such processes is the complete fusion, which takes place when the whole mass of the projectile fuses with the target. There may be fusion following breakup. In this case, the compound nucleus may contain the whole mass of the projectile (through sequential fusion of the fragments), or some fragment can escape the interaction region. The former corresponds also to complete fusion (sequential complete fusion) while the latter is known as incomplete fusion. So far

  7. Atomic data for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.); Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

  8. Atomic data for fusion

    International Nuclear Information System (INIS)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A.; Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research

  9. Concepts for fusion fuel production blankets

    International Nuclear Information System (INIS)

    Gierszewski, P.

    1986-06-01

    The fusion blanket surrounds the burning hydrogen core of the fusion reactor. It is in this blanket that most of the energy released by the DT fusion reaction is converted into useable product, and where tritium fuel is produced to enable further operation of the reactor. Blankets will involve new materials, conditions and processes. Several recent fusion blanket concepts are presented to illustrate the range of ideas

  10. Detection of alveolar rhabdomyosarcoma in pleural fluid with immunocytochemistry on cell block and determination of PAX/FKHR fusion mRNA by reverse transcription-polymerase chain reaction.

    Science.gov (United States)

    Sawangpanich, Ruchchadol; Larbcharoensub, Noppadol; Jinawath, Artit; Pongtippan, Atcharaporn; Anurathapan, Usanarat; Hongeng, Suradej

    2011-11-01

    Alveolar rhabdomyosarcoma is a primitive malignant round cell neoplasm, which shows skeletal muscle differentiation. Although their histopathologic and immunohistochemical findings are well known, the cytology, immunocytochemistry and molecular study on pleural effusion have not been well documented. To apply molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma. The case of a 14-year-old Thai male, who presented with dyspnea and left pleural effusion. Computed tomography of the chest and abdomen showed a huge heterogeneous enhancing mass at the left retroperitoneum. Pleural fluid cytology showed malignant small round blue cells. Immunocytochemical stains on cell block material showed positive reactivity to vimentin, sarcomeric actin, desmin, MyoD1, myogenin, and CD56 in round cell tumor Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated PAX/FKHR fusion transcript. The patient received chemotherapeutic regimen for advanced-stage rhabdomyosarcoma. Finally, he succumbed to the disease, thirteen months after the diagnosis. Immunocytochemistry on cell block in conjunction with determination of PAX/FKHR fusion mRNA by RT-PCR is a molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma inpleural fluid.

  11. Assessment of fusion facility dose rate map using mesh adaptivity enhancements of hybrid Monte Carlo/deterministic techniques

    International Nuclear Information System (INIS)

    Ibrahim, Ahmad M.; Wilson, Paul P.; Sawan, Mohamed E.; Mosher, Scott W.; Peplow, Douglas E.; Grove, Robert E.

    2014-01-01

    Highlights: •Calculate the prompt dose rate everywhere throughout the entire fusion energy facility. •Utilize FW-CADIS to accurately perform difficult neutronics calculations for fusion energy systems. •Develop three mesh adaptivity algorithms to enhance FW-CADIS efficiency in fusion-neutronics calculations. -- Abstract: Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer

  12. Development of Portable Pulsed Neutron Generators Utilizing a D-T or D-D Fusion Reaction

    International Nuclear Information System (INIS)

    Nishimura, Kazuya; Miake, Yoshinobu; Kato, Michio; Rintsu, Yukou

    2001-01-01

    Prototypes of sealed neutron tubes in a D-T or D-D fusion reaction for logging while drilling (LWD) were developed; then operational tests were performed to check their functional properties. One of the prototypes passed most of the specified conditions for using LWD. Further studies were needed to put a sealed neutron tube into practical use. For applications to other fields, such as an in situ calibration source for neutron detector efficiencies and an in situ calibration source for fusion systems, a sealed neutron tube is needed to have higher-intensity neutron output and a long life. Thus, the performance of the ion source used in the neutron tube is improved to obtain high gas utilization efficiencies or low-pressure operation with high ionization efficiencies. The characteristics of the new ion sources used in the foregoing sealed neutron tube are discussed in terms of preliminary tests. The aforementioned performances are obtained

  13. Breeder control fusion reactor. Topical interview

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, A [Max-Planck-Institut fuer Plasmaphysik, Garching/Muenchen (Germany, F.R.)

    1977-09-01

    The energy sources of the future are extremely controversial. The consumption of fossil fuel shall decrease during the next decades, because exhaustion of the resources, pollution, increase of CO/sub 2/ in the atmosphere and other reasons. But at present the question it not yet settled which alternative energy system should replace the fossil fuel. First of all nuclear energy in the form of fission reactions seems to come into operation to a larger extent. The next step may be the controlled thermonuclear fusion reaction. Furthermore, a comparison between fusion and fission is given which shows that fusion would bring about less risks than the breeders. An advantage of the fusion reactor would be the fact that the fuel cycle is closed. Unfortunately, the physical questions are not as yet satisfactorily clarified so that one cannot be sure whether a fusion reactor can really be built.

  14. Comparison of different Skyrme forces: Fusion barriers and fusion cross sections

    International Nuclear Information System (INIS)

    Puri, R.K.; Gupta, R.K.

    1995-01-01

    Fusion barriers and fusion cross sections are calculated using the Skyrme energy-density formalism. To study the role of different parametrizations of the Skyrme interaction, we use two typical forces, i.e., the original Skyrme force S and the widely used Skyrme force SIII. Our calculations show that, in the reactions considered here, the Skyrme force S gives higher fusion cross sections compared to that of the Skyrme force SIII. The main part of this difference can be associated with the presence of the spin-density contribution in the Skyrme force SIII

  15. Coatings for fusion reactor environments

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1979-01-01

    The internal surfaces of a tokamak fusion reactor control the impurity injection and gas recycling into the fusion plasma. Coating of internal surfaces may provide a desirable and possibly necessary design flexibility for achieving the temperatures, ion densities and containment times necessary for net energy production from fusion reactions to take place. In this paper the reactor environments seen by various componentare reviewed along with possible materials responses. Characteristics of coating-substrate systems, important to fusion applications, are delineated and the present status of coating development for fusion applications is reviewed. Coating development for fusion applications is just beginning and poses a unique and important challenge for materials development

  16. Advanced fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Yukihiro [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2003-04-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p-{sup 6}Li and p-{sup 11}B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D-{sup 3}He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D-{sup 3}He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of {sup 3}He per a year. On the other hand, 1 million tons of {sup 3}He is estimated to be in the moon. The {sup 3}He of about 10{sup 23} kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  17. Nuclear fusion

    International Nuclear Information System (INIS)

    Huber, H.

    1978-01-01

    A comprehensive survey is presented of the present state of knowledge in nuclear fusion research. In the first part, potential thermonuclear reactions, basic energy balances of the plasma (Lawson criterion), and the main criteria to be observed in the selection of appropriate thermonuclear reactions are dealt with. This is followed by a discussion of the problems encountered in plasma physics (plasma confinement and heating, transport processes, plasma impurities, plasma instabilities and plasma diagnostics) and by a consideration of the materials problems involved, such as material of the first wall, fuel inlet and outlet, magnetic field generation, as well as repair work and in-service inspections. Two main methods have been developed to tackle these problems: reactor concepts using the magnetic pinch (stellarator, Tokamak, High-Beta reactors, mirror machines) on the one hand, and the other concept using the inertial confinement (laser fusion reactor). These two approaches and their specific problems as well as past, present and future fusion experiments are treated in detail. The last part of the work is devoted to safety and environmental aspects of the potential thermonuclear aspects of the potential thermonuclear reactor, discussing such problems as fusion-specific hazards, normal operation and potential hazards, reactor incidents, environmental pollution by thermal effluents, radiological pollution, radioactive wastes and their disposal, and siting problems. (orig./GG) [de

  18. Ch. 37, Inertial Fusion Energy Technology

    International Nuclear Information System (INIS)

    Moses, E.

    2010-01-01

    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

  19. Reaction mechanisms for the synthesis of the heaviest elements from heavy ion reactions

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1988-10-01

    This review paper concerns fusion reactions with light heavy-ions, cold fusion, transfer reactions using light heavy-ions or heavy ions. In two appendices, methods for the separation and detection of nuclides in the domain of heaviest elements are described and a comment on the discovery of the element 104 is given. 51 figs., 10 tabs., 335 refs

  20. Fusion as a source of synthetic fuels

    International Nuclear Information System (INIS)

    Powell, J.R.; Fillo, J.A.; Steinberg, M.

    1981-01-01

    In the near-term, coal derived synthetic fuels will be used; but in the long-term, resource depletion and environmental effects will mandate synthetic fuels from inexhaustible sources - fission, fusion, and solar. Of the three sources, fusion appears uniquely suited for the efficient production of hydrogen-based fuels, due to its ability to directly generate very high process temperatures (up to approx. 2000 0 C) for water splitting reactions. Fusion-based water splitting reactions include high temperature electrolysis (HTE) of steam, thermochemical cycles, hybrid electrochemical/thermochemical, and direct thermal decomposition. HTE appears to be the simplest and most efficient process with efficiencies of 50 to 70% (fusion to hydrogen chemical energy), depending on process conditions

  1. Intense fusion neutron sources

    International Nuclear Information System (INIS)

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

    2010-01-01

    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 10 15 -10 21 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 10 20 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.

  2. Intense fusion neutron sources

    Science.gov (United States)

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

    2010-04-01

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

  3. Examining empirical evidence of the effect of superfluidity on the fusion barrier

    Science.gov (United States)

    Scamps, Guillaume

    2018-04-01

    Background: Recent time-dependent Hartree-Fock-Bogoliubov (TDHFB) calculations predict that superfluidity enhances fluctuations of the fusion barrier. This effect is not fully understood and not yet experimentally revealed. Purpose: The goal of this study is to empirically investigate the effect of superfluidity on the distribution width of the fusion barrier. Method: Two new methods are proposed in the present study. First, the local regression method is introduced and used to determine the barrier distribution. The second method, which requires only the calculation of an integral of the cross section, is developed to determine accurately the fluctuations of the barrier. This integral method, showing the best performance, is systematically applied to 115 fusion reactions. Results: Fluctuations of the barrier for open-shell systems are, on average, larger than those for magic or semimagic nuclei. This is due to the deformation and the superfluidity. To disentangle these two effects, a comparison is made between the experimental width and the width estimated from a model that takes into account the tunneling, the deformation, and the vibration effect. This study reveals that superfluidity enhances the fusion barrier width. Conclusions: This analysis shows that the predicted effect of superfluidity on the width of the barrier is real and is of the order of 1 MeV.

  4. Review for 'Nattoh' model and experimental findings during cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, Takaaki

    1993-01-01

    A review is described for the Nattoh model that provides the framework of the mechanisms of cold fusion. The model classifies the reactions into two categories: fundamental and associated reactions. The former involves the new 'hydrogen-catalyzed' fusion reaction and the chain-reactions of hydrogens. And extremely exciting physics are involved in the latter. Furthermore experimental findings are described. (author)

  5. Study of fusion cross-sections of 16O + 208Pb and 28Si + 208Pb reactions by effective soft-core nucleon-nucleon interaction

    International Nuclear Information System (INIS)

    Ghodsi, O. N.; Mahmodi, M.; Ariai, J.; O. N. Ghodsi)

    2007-01-01

    In this paper, the cross-sections of fusion reactions 16 O + 208 Pb, 28 Si + 208 Pb, 40 C + 40 Ca, 40 Ca + 48 Ca, 58 Ni + 58 Ni, and 16 O + 154 Sm at bombarding energies above and near the fusion barrier have been investigated. The fusion cross-sections have been studied by means of the Monte Carlo method and effective soft-core nucleon-nucleon interaction. One adjustable parameter was used in these calculations. This parameter can change the strength and repulsive parts of soft-core potential values. It has to be adjusted, so that the analytical results are in acceptable agreement with the experimental data. In our calculations, we have taken the range of the nucleon-nucleon soft-core interaction to be constant and equal to that of the M3Y-Raid potential. Results show that the higher values for the diffusion parameter in the Woods-Saxon potential obtained from a careful analysis of 16 O + 208 Pb and 28 Si + 208 Pb reactions are due to the many particle effects on the nucleon-nucleon potential. (author)

  6. Study of fusion cross-sections of 16O + 208Pb and 28Si + 208Pb reactions by effective soft-core nucleon-nucleon interaction

    Directory of Open Access Journals (Sweden)

    Ghodsi Omid N.

    2007-01-01

    Full Text Available In this paper, the cross-sections of fusion reactions 16O + 208Pb, 28Si + 208Pb, 40C + + 40Ca, 40Ca + 48Ca, 58Ni + 58Ni, and 16O + 154Sm at bombarding energies above and near the fusion barrier have been investigated. The fusion cross-sections have been studied by means of the Monte Carlo method and effective soft-core nucleon-nucleon interaction. One adjustable parameter was used in these calculations. This parameter can change the strength and repulsive parts of soft-core potential values. It has to be adjusted, so that the analytical results are in acceptable agreement with the experimental data. In our calculations, we have taken the range of the nucleon-nucleon soft-core interaction to be constant and equal to that of the M3Y-Raid potential. Results show that the higher values for the diffusion parameter in the Woods-Saxon potential obtained from a careful analysis of 16O + 208Pb and 28Si + 208Pb reactions are due to the many particle effects on the nucleon-nucleon potential.

  7. Laser-induced nuclear fusion

    International Nuclear Information System (INIS)

    Jablon, Claude

    1977-01-01

    Research programs on laser-induced thermonuclear fusion in the United States, in Europe and in USSR are reviewed. The principle of the fusion reactions induced is explained, together with the theoretical effects of the following phenomena: power and type of laser beams, shape and size of the solid target, shock waves, and laser-hydrodynamics coupling problems [fr

  8. Elastic scattering, fusion, and breakup of light exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kolata, J.J. [University of Notre Dame, Physics Department, Notre Dame, IN (United States); Guimaraes, V. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Aceleradores, Mexico, Distrito Federal (Mexico)

    2016-05-15

    The present status of fusion reactions involving light (A< 20) radioactive projectiles at energies around the Coulomb barrier (E<10 MeV per nucleon) is reviewed, emphasizing measurements made within the last decade. Data on elastic scattering (providing total reaction cross section information) and breakup channels for the involved systems, demonstrating the relationship between these and the fusion channel, are also reviewed. Similarities and differences in the behavior of fusion and total reaction cross section data concerning halo nuclei, weakly-bound but less exotic projectiles, and strongly-bound systems are discussed. One difference in the behavior of fusion excitation functions near the Coulomb barrier seems to emerge between neutron-halo and proton-halo systems. The role of charge has been investigated by comparing the fusion excitation functions, properly scaled, for different neutron- and proton-rich systems. Possible physical explanations for the observed differences are also reviewed. (orig.)

  9. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  10. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  11. Cold fusion produces more tritium than neutrons

    International Nuclear Information System (INIS)

    Rajagopalan, S.R.

    1989-01-01

    The results of the major cold fusion experiments performed in various laboratories of the world and attempts to explain them are reviewed in brief. Particular reference is made to the experiments carried out in the Bhabha Atomic Research Centre (BARC), Bombay. In BARC experiments, it is found that tritium is the primary product of cold fusion. Author has put forward two hypothetical pictures of D-D fusion. (1) When a metal like Pd or Ti is loaded with D 2 , a crack forms. Propogation of such a crack accelerates deuterons which bombard Pd D 2 /D held by Pd or Ti leading to neutron capture or tritium formation with the release of protons and energy. The released protons might transfer its energy to some other deuteron and a chain reaction is started. This chain reaction terminates when a substantial portion of D in the crack tip is transmuted. This picture explains fusion reaction bursts and the random distribution of reaction sites, but does not explain neutron emission. (2) The deuterons accelerated by a propogating crack may hit a Pd/Ti nucleus instead of a deuterium nucleus and may transmute Pd/Ti. (M.G.B.). 18 refs

  12. Decomposition of incomplete fusion

    International Nuclear Information System (INIS)

    Sobotka, L.B.; Sarantities, D.G.; Stracener, D.W.; Majka, Z.; Abenante, V.; Semkow, T.M.; Hensley, D.C.; Beene, J.R.; Halbert, M.L.

    1989-01-01

    The velocity distribution of fusion-like products formed in the reaction 701 MeV 28 Si+ 100 Mo is decomposed into 26 incomplete fusion channels. The momentum deficit of the residue per nonevaporative mass unit is approximately equal to the beam momentum per nucleon. The yields of the incomplete fusion channels correlate with the Q-value for projectile fragmentation rather than that for incomplete fusion. The backward angle multiplicities of light particles and heavy ions increase with momentum transfer, however, the heavy ion multiplicities also depend on the extent of the fragmentation of the incomplete fusion channel. These data indicate that at fixed linear momentum transfer, increased fragmentation of the unfused component is related to a reduced transferred angular momentum. 22 refs., 6 figs., 1 tab

  13. Fusion Physics

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Mitsuru; Lackner, Karl; Tran, Minh Quang [eds.

    2012-09-15

    Recreating the energy production process of the Sun - nuclear fusion - on Earth in a controlled fashion is one of the greatest challenges of this century. If achieved at affordable costs, energy supply security would be greatly enhanced and environmental degradation from fossil fuels greatly diminished. Fusion Physics describes the last fifty years or so of physics and research in innovative technologies to achieve controlled thermonuclear fusion for energy production. The International Atomic Energy Agency (IAEA) has been involved since its establishment in 1957 in fusion research. It has been the driving force behind the biennial conferences on Plasma Physics and Controlled Thermonuclear Fusion, today known as the Fusion Energy Conference. Hosted by several Member States, this biennial conference provides a global forum for exchange of the latest achievements in fusion research against the backdrop of the requirements for a net energy producing fusion device and, eventually, a fusion power plant. The scientific and technological knowledge compiled during this series of conferences, as well as by the IAEA Nuclear Fusion journal, is immense and will surely continue to grow in the future. It has led to the establishment of the International Thermonuclear Experimental Reactor (ITER), which represents the biggest experiment in energy production ever envisaged by humankind.

  14. Observed side feeding in incomplete fusion dynamics in 16O + 160Gd reaction at energy ∼5.6 MeV/A: Spin distribution measurements

    Science.gov (United States)

    Ali, Rahbar; Afzal Ansari, M.; Singh, D.; Kumar, Rakesh; Singh, D. P.; Sharma, M. K.; Gupta, Unnati; Singh, B. P.; Shidling, P. D.; Negi, Dinesh; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

    2017-12-01

    Spin distributions of various residues populated via complete fusion (CF) and incomplete fusion (ICF) reactions in the interaction of 16O with 160Gd at the projectile energy Eproj ∼ 5.6 MeV/A have been studied. The experimentally measured spin distributions of the residues associated with the ICF reactions are found to be distinctly different from those populated via the CF reactions. An attempt has been made to extract the side-feeding pattern from the spin distributions of CF and ICF reaction products. It has been observed that the CF products are strongly fed over a broad spin range. But, no side-feeding takes place in the low observed spins as low partial waves are strongly hindered in the fast α-emission channels (associated with ICF) in the forward direction. It has also been observed that the mean input angular momentum for direct α-emitting (ICF) channels is relatively higher than evaporation α-emitting (CF) channels, and it increases with direct α-multiplicity in forward direction.

  15. Reactions with Weakly Bound Nuclei, at near Barrier Energies, and the Breakup and Transfer Influences on the Fusion and Elastic Scattering

    International Nuclear Information System (INIS)

    Gomes, P. R. S.; Lubian, J.; Mendes-Junior, D. R.; Faria, P. N. de; Linares, R.; Sigaud, L.; Rangel, J.; Ferreira, J. L.; Paes, B.; Cardozo, E. N.; Cortes, M. R.; Canto, L. F.; Ermamatov, M. J.; Otomar, D. R.; Ferioli, E.; Lotti, P.; Hussein, M. S.

    2016-01-01

    We present a brief review of the reaction mechanisms involved in collisions of weakly bound projectiles with tightly bound targets, at near-barrier energies. We discuss systematic behaviors of the data, with emphasis in fusion, breakup, nucleon transfer and elastic scattering. The dependence of the breakup cross section on the charge and mass of the target is discussed, and the influence of the breakup channel on complete fusion is investigated. For this purpose, we compare reduced fusion cross sections with a benchmark universal curve. The behaviors observed in the comparisons are explained in terms of polarization potentials and of nucleon transfer followed by breakup. The influence of the breakup process on elastic scattering is also discussed. Some apparent contradictions between results of different authors are explained and some perspectives of the field are presented. (author)

  16. Enhanced emission of non-compound light particles in the reaction plane

    International Nuclear Information System (INIS)

    Tsang, M.B.

    1984-01-01

    In an experiment performed at the K500 cyclotron at Michigan State University, light particles in coincidence with two fission fragments for 14 N induced reactions on 197 Au at 420 MeV incident energy have been measured. The fission fragments were detected with two large area position sensitive parallel plate avalanche detectors. Light particle telescopes consisting of silicon-ΔE and Nal-E detectors were placed both in and out of the plane defined by the centers of the two fission detectors and the beam axis. The momentum transferred to the composite system was determined by measuring the folding angle between the two outgoing fission fragments. Unlike observations with more fissile targets, however, transfer and inelastic reactions characterized by small linear momentum transfers contribute negligibly to the fission cross section for reactions on the 197 Au target. For events which lead to fission, the most probable linear momentum transfer corresponded to about 85% of the beam momentum. This is similar to the most probable momentum transfer observed for fusion-like reactions on 238 U at the same beam energy. Much of the missing momentum is carried away by non-equilibrium light particle emission

  17. HALO: a reconfigurable image enhancement and multisensor fusion system

    Science.gov (United States)

    Wu, F.; Hickman, D. L.; Parker, Steve J.

    2014-06-01

    Contemporary high definition (HD) cameras and affordable infrared (IR) imagers are set to dramatically improve the effectiveness of security, surveillance and military vision systems. However, the quality of imagery is often compromised by camera shake, or poor scene visibility due to inadequate illumination or bad atmospheric conditions. A versatile vision processing system called HALO™ is presented that can address these issues, by providing flexible image processing functionality on a low size, weight and power (SWaP) platform. Example processing functions include video distortion correction, stabilisation, multi-sensor fusion and image contrast enhancement (ICE). The system is based around an all-programmable system-on-a-chip (SoC), which combines the computational power of a field-programmable gate array (FPGA) with the flexibility of a CPU. The FPGA accelerates computationally intensive real-time processes, whereas the CPU provides management and decision making functions that can automatically reconfigure the platform based on user input and scene content. These capabilities enable a HALO™ equipped reconnaissance or surveillance system to operate in poor visibility, providing potentially critical operational advantages in visually complex and challenging usage scenarios. The choice of an FPGA based SoC is discussed, and the HALO™ architecture and its implementation are described. The capabilities of image distortion correction, stabilisation, fusion and ICE are illustrated using laboratory and trials data.

  18. Effect of deformations on the compactness of odd-Z superheavy nuclei formed in cold and hot fusion reactions

    Science.gov (United States)

    Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

    2018-03-01

    Using the extended fragmentation theory, the compactness of hot and cold fusion reactions is analyzed for odd-Z nuclei ranging Z = 105- 117. The calculations for the present work are carried out at T = 0MeV and ℓ = 0 ħ, as the temperature and angular momentum effects remain silent while addressing the orientation degree of freedom (i.e. compact angle configuration). In the hot fusion, 48Ca (spherical) + actinide (prolate) reaction, the non-equatorial compact (nec) shape is obtained for Z = 113 nucleus. On the other hand, Z > 113 nuclei favor equatorial compact (ec) configuration. The distribution of barrier height (VB) illustrate that the ec-shape is obtained when the magnitude of quadrupole deformation of the nucleus is higher than the hexadecupole deformation. In other words, negligible or small -ve β4-deformations support ec configurations. On the other hand, large (+ve) magnitude of the β4-deformation suggests that the configuration appears for compact angle θc < 90 °, leading to nec structure. Similar deformation effects are observed for Bi-induced reactions, in which not belly-to-belly compact (nbbc) configurations are seen at θc = 42 °. In addition to the effect of β2 and β4-deformations, the exclusive role of octupole deformations (β3) is also analyzed. The β3-deformations do not follow the reflection symmetry as that of β2 and β4, leading to the possible occurrence of compact configuration within 0° to 180° angular range.

  19. Perspectives of fusion power

    International Nuclear Information System (INIS)

    Jensen, V.O.

    1984-01-01

    New and practically inexhaustible sources of energy must be developed for the period when oil, coal and uranium will become scarce and expensive. Nuclear fusion holds great promise as one of these practically inexhaustible energy sources. Based on the deuteriumtritium reaction with tritium obtained from naturally occuring lithium, which is also widely available in Europe, the accessible energy resources in the world are 3.10 12 to 3.10 16 toe; based on the deuterium-deuterium reaction, the deuterium content of the oceans corresponds to 10 20 toe. It is presently envisaged that in order to establish fusion as a large-scale energy source, three major thresholds must be reached: - Scientific feasibility, - Technical feasibility, i.e. the proof that the basic technical problems of the fusion reactor can be solved. - Commercial feasibility, i.e. proof that fusion power reactors can be built on an industrial scale, can be operated reliably and produce usable energy at prices competitive with other energy sources. From the above it is clear that the route to commercial fusion will be long and costly and involve the solution of extremely difficult technical problems. In view of the many steps which have to be taken, it appears unlikely that commercial fusion power will be in general use within the next 50 years and by that time world-wide expenditure on research, development and demonstration may well have exceeded 100 Bio ECU. (author)

  20. Analysis of complete fusion excitation functions for 7Li+152Sm, 197Au and 209Bi reactions at around barrier energies

    International Nuclear Information System (INIS)

    Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

    2017-01-01

    In the present work we have analyzed the fusion excitation function for CF process using the simple Wong’s formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in near barrier energy region for 7 Li+ 152 Sm, 197 Au and 209 Bi reactions

  1. Nuclear structure and fusion at the barrier

    International Nuclear Information System (INIS)

    Reisdorf, W.

    1985-01-01

    A comparative study of measured fusion excitation functions in the vicinity of the barrier reveals nuclear structure effects, due in particular to the coupling of the fusion process to direct-reaction channels. (orig.)

  2. Stripping of two protons and one alpha particle transfer reactions for {sup 16} O + {sup A} Sm and their influence on the fusion cross section

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, A.M.M.; Gomes, P.R.S

    1995-12-31

    Transfer cross section angular distribution data for the stripping of two protons and one alpha particle are studied for the {sup 16} O + {sup A} Sm systems (A=144, 148, 150, 152 and 154), at near barrier energies. A semiclassical formalism is used to derive the corresponding transfer form factors. For only one channel the analysis shows evidences that the transfer reaction mechanism at backward angles - corresponding to small distances, may behave as a multi-step process leading to fusion. Simplified coupled channel calculations including transfer channels are performed for the study of the sub-barrier of these systems. The influence of short distance transfer reactions on the fusion is discussed. (author) 16 refs., 5 figs., 5 tabs.

  3. A compensatory mutation provides resistance to disparate HIV fusion inhibitor peptides and enhances membrane fusion.

    Directory of Open Access Journals (Sweden)

    Matthew P Wood

    Full Text Available Fusion inhibitors are a class of antiretroviral drugs used to prevent entry of HIV into host cells. Many of the fusion inhibitors being developed, including the drug enfuvirtide, are peptides designed to competitively inhibit the viral fusion protein gp41. With the emergence of drug resistance, there is an increased need for effective and unique alternatives within this class of antivirals. One such alternative is a class of cyclic, cationic, antimicrobial peptides known as θ-defensins, which are produced by many non-human primates and exhibit broad-spectrum antiviral and antibacterial activity. Currently, the θ-defensin analog RC-101 is being developed as a microbicide due to its specific antiviral activity, lack of toxicity to cells and tissues, and safety in animals. Understanding potential RC-101 resistance, and how resistance to other fusion inhibitors affects RC-101 susceptibility, is critical for future development. In previous studies, we identified a mutant, R5-tropic virus that had evolved partial resistance to RC-101 during in vitro selection. Here, we report that a secondary mutation in gp41 was found to restore replicative fitness, membrane fusion, and the rate of viral entry, which were compromised by an initial mutation providing partial RC-101 resistance. Interestingly, we show that RC-101 is effective against two enfuvirtide-resistant mutants, demonstrating the clinical importance of RC-101 as a unique fusion inhibitor. These findings both expand our understanding of HIV drug-resistance to diverse peptide fusion inhibitors and emphasize the significance of compensatory gp41 mutations.

  4. A systematic study on the influence of nuclear surface tension and temperature upon the parameterization of the fusion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Gharaei, R.; Hadikhani, A. [Hakim Sabzevari University, Department of Physics, Sciences Faculty, Sabzevar (Iran, Islamic Republic of)

    2017-07-15

    For the first time the influence of the surface energy coefficient γ and temperature T on the parameterization of the fusion barriers is systematically analyzed within the framework of the proximity formalism, namely proximity 1977, proximity 1988 and proximity 2010 models. A total of 114 fusion reactions with the condition 39 ≤ Z{sub 1}Z{sub 2} ≤ 1520 for the charge product of their participant nuclei have been studied. We present γ-dependent and T -dependent pocket formulas which reproduce the theoretical and empirical data of the fusion barrier height and position for our considered reactions with good accuracy. It is shown that the quality of the γ-dependent formula enhances by increasing the strength of the surface energy coefficient. Moreover, the obtained results confirm that imposing the thermal effects improves the agreement between the parameterized and empirical data of the barrier characteristics. (orig.)

  5. Yrast spectroscopy in {sup 49-51}Ti via fusion-evaporation reaction induced by a radioactive beam

    Energy Technology Data Exchange (ETDEWEB)

    Niikura, M.; Ideguchi, E.; Michimasa, S.; Ota, S.; Shimoura, S.; Wakabayashi, Y. [University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Aoi, N.; Baba, H.; Fukuchi, T.; Ichikawa, Y.; Kubo, T.; Kurokawa, M.; Ohnishi, T.; Suzuki, H.; Yoshida, K. [RIKEN Nishina Center, Wako, Saitama (Japan); Iwasaki, H.; Onishi, T.K.; Suzuki, D. [University of Tokyo, Department of Physics, Tokyo (Japan); Liu, M.; Zheng, Y. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2009-12-15

    In-beam {gamma} -ray spectroscopy of high-spin states in {sup 49-51}Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and {gamma} - {gamma} coincidence analysis, yrast high-spin levels up to I=(21/2{sup -}),(11{sup +}),(17/2{sup -}) in {sup 49-51}Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N=28 shell gap at yrast states in {sup 49-51}Ti. (orig.)

  6. Application of polarized nuclei to fusion

    International Nuclear Information System (INIS)

    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

  7. Gross resonance-like structure of the complete fusion excitation function for the 16O + 28Si reaction

    International Nuclear Information System (INIS)

    Zheng Jiwen; Zheng Pingzi; Liu Guoxing

    1993-01-01

    The complete fusion excitation function for the 16 O + 28 Si reaction is measured in the incident energy range from 50 to 90 MeV with step of 1.0 MeV using a position sensitive ΔE-E telescope system. The striking gross resonance-like structure is observed when E c.m. c.m. 34.5, 38.5 and 43.0 MeV respectively. The structure vanishes gradually when E c.m. > 46.0 MeV

  8. An electrolytic route to fusion?

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    A patent has been granted by the Swedish Patent Authority for a new process to initiate and control energy generation through fusion reactions of hydrogen. According to the patent-holder, the Swedish company AB Technology Development, the fusion power process could be available for commercial applications within 4-5 years if laboratory and pilot plant tests prove successful. The new process employs a high voltage discharge in heavy water to create conditions under which, according to the patent holder, a high probability of fusion is achieved without the extraordinary high temperatures required in a conventional fusion reactor. (author)

  9. Inertial fusion with hypervelocity impact

    International Nuclear Information System (INIS)

    Olariu, S.

    1998-01-01

    The physics of the compression and ignition processes in inertial fusion is to a certain extent independent of the nature of the incident energy pulse. The present strategy in the field of inertial fusion is to study several alternatives of deposition of the incident energy, and, at the same time, of conducting studies with the aid of available incident laser pulses. In a future reactor based on inertial fusion, the laser beams may be replaced by ion beams, which have a better energy efficiency. The main projects in the field of inertial fusion are the National Ignition Facility (NIF) in USA, Laser Megajoule (LMJ) in France, Gekko XII in Japan and Iskra V in Russia. NIF will be constructed at Lawrence Livermore National Laboratory, in California. LMJ will be constructed near Bordeaux. In the conventional approach to inertial confinement fusion, both the high-density fuel mass and the hot central spot are supposed to be produced by the deposition of the driver energy in the outer layers of the fuel capsule. Alternatively, the driver energy could be used only to produce the radial compression of the fuel capsule to high densities but relatively low temperatures, while the ignition of fusion reactions in the compressed capsule should be effected by a synchronized hypervelocity impact. Using this arrangement, it was supposed that a 54 μm projectile is incident with a velocity of 3 x 10 6 m s -1 upon a large-yield deuterium-tritium target at rest. The collision of the incident projectile and of the large-yield target takes place inside a high-Z cavity. A laser or heavy-ion pulse is converted at the walls of the cavity into X-rays, which compresses the incident projectile and the large-yield target in high-density states. The laser pulse and the movement of the incident projectile are synchronized such that the collision should take place when the densities are the largest. The collision converts the kinetic energy of the incident projectile into thermal energy, the

  10. Fusion, magnetic confinement

    International Nuclear Information System (INIS)

    Berk, H.L.

    1992-01-01

    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 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

  11. Fusion, resonances and scattering in C reaction

    Indian Academy of Sciences (India)

    respectively. In each of these regions, we find some important features in the results ofσfus. ... draws attention in the astrophysical studies [2,7]. Here, Ecm and η .... We outline the concept of selective resonance tunneling for fusion in Ü3. In Ü4 ...

  12. Near and sub-barrier reactions of 8B

    Directory of Open Access Journals (Sweden)

    Kolata J. J.

    2017-01-01

    Full Text Available Four classes of measurements that are important for achieving a complete understanding of the reactions of exotic nuclei are identified and classified according to their degree of difficulty. Previously reported data for near- and sub-barrier fusion of 8B+58Ni are critically reviewed. The influence of breakup protons on the evaporation proton measurements for this system is shown to be small at all energies except for the lowest one measured, and corrections are made for this process. Model dependencies in the deduced fusion cross sections are assessed using three different evaporation codes. Data sets for targets of 58Ni and 28Si are shown to be consistent with each other, and with fusion enhancement up to energies that are greater than the Coulomb barrier Vb (Ec.m. ≲ Vb + 1.5×ћω. An important difference with the behavior of neutron-halo systems is thereby confirmed. Possible fusion suppression beyond this energy is suggested by the 28Si data. A proposal to measure the 8B+40Ar fusion cross section using an active-target time projection chamber is discussed.

  13. Nuclear Landau-Zener phenomena and the fusion cross sections in the system 13C + 16O → 12C + 17O

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1990-07-01

    Reaction mechanism of the system 13 C+ 16 O- 12 C+ 17 O is investigated with the use of the nucleon molecular-orbital model in the framework of the orthogonalized coupled-reaction-channel (OCRC) theory. The adiabatic potentials obtained are quite different from the diagonal potentials of the original OCRC basis. The Landau-Zener radial coupling explains the backward enhancement of measured differential cross sections of the transfer reaction 13 C( 16 O, 17 O) 12 C. In the OCRC calculation the fusion cross sections of the channel 13 C+ 16 O is enhanced at low bombarding energies, in agreement with the experimental data. (author)

  14. Evaluation of cell binding peptide (p15) with silk fibre enhanced hydroxyappatite bone substitute for posterolateral spinal fusion in sheep

    DEFF Research Database (Denmark)

    Axelsen, M.; Jespersen, Stig; Overgaard, Søren

    2015-01-01

    Background: Spinal fusion is indicated in the surgical management of various spinal disorders. To ensure stabile fusion, bone graft materials are essential. Traditionally allo- or autograft has been used, but both are associated with limitations. Synthetic bone graft materials that reassemble today......: In this study, we compared fusion rates between silk fibre enhanced anorganic bovine derived hydroxyapatite matrix (ABM) with and without P15 peptide coating in uninstrumented PLF in a preclinical setting. Study design: Randomised prospective study in sheep. Method/materials: Twelve Tex/got sheep underwent open...

  15. Unichannel description of the fusion reactions

    International Nuclear Information System (INIS)

    Franzin, V.L.M.

    1987-01-01

    Using an effective one channel model which contains channel coupling effects through the presence of an inclusive energy - dependent polarization potential it was studied sub-barrier fusion of the systems A1 Ni+ A2 N1 and 16 O+ A Sm. The consistency of this method is checked by comparing this empirical polarization potential with the one determined from the explicit consideration of a specific channel coupling. (A.C.A.S.) [pt

  16. $\\gamma$ -spectroscopy of n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li

    CERN Multimedia

    We propose an experiment with MINIBALL coupled to T-REX to investigate n-rich $^{95,96}$Rb nuclei by the incomplete fusion reaction of $^{94}$Kr on $^{7}$Li. The nuclei of interest will be populated by transfer of a triton into $^{94}$Kr, forming the excited $^{97}$Rb nucleus, followed by the emission of an alpha particle, which will be detected in the Si telescopes of T-REX. The $^{97}$Rb product will evaporate 1 or 2 (with the highest probability) neutrons leading to $^{96}$Rb or $^{95}$Rb, respectively. The aim of the experiment is twofold: \\\\ i) to perform a $\\gamma$- spectroscopy study of $^{95,96}$Rb nuclei with N=58,59, the structure of which is of particular interest in investigating the transition towards stable deformation at N=60, \\\\ ii) to acquire experience in using incomplete fusion reactions with the weakly bound $^{7}$Li target, in order to perform, at a later stage with HIE-ISOLDE, similar measurements induced by n-rich radioactive beams of Sn and Hg, for which at least 5 MeV/nucleon are need...

  17. Pulsed fission/fusion hybrid engines

    International Nuclear Information System (INIS)

    Hudson, G.C.

    1979-01-01

    Research into high-thrust, high-specific impulse rocket engines using energy from nuclear reactions which has been conducted at this organization will be discussed. The engines are all conceptual in nature, yet are within the realization of conventional or near-term technology. The engine concepts under study at Foundation, Inc. are designed to obviate or minimize these negative effects of the ORION scheme. By using non-chemical triggers to initiate a non-breakeven fusion reaction at the core of a target composed of both fission and fusion fuel, it should be possible to employ the fusion neutrons thus produced to begin a fission reaction in U-235 or Pu-239. Since the density of the target can be increased by as much as a factor of 250 through compression of the pellet, the amount of fission material necessary to produce a critical mass can be greatly reduced. (This also means that the amount of fission products produced for a giventhrust level is also reduced from the ORION levels.) Coupling this eeffect to the large number of 14 MeV fusion neutrons produced early in the compression process and subsequently to the heating of some additional fusion fuel surrounding the critical mass leads to the very efficient burnup of the target. This insures both high yield from the target as well as low cost per MJ energy released. Finally, the use of such small pellets allows the scale of the energy released to be tailored to a level usable in rocket engines of a few tens of tons thrust level. (orig.) [de

  18. Influence of projectile α-breakup threshold on complete fusion

    International Nuclear Information System (INIS)

    Mukherjee, A.; Subinit Roy; Pradhan, M.K.; Saha Sarkar, M.; Basu, P.; Dasmahapatra, B.; Bhattacharya, T.; Bhattacharya, S.; Basu, S.K.; Chatterjee, A.; Tripathi, V.; Kailas, S.

    2006-01-01

    Complete fusion excitation functions for B11,10+Tb159 have been measured at energies around the respective Coulomb barriers, and the existing complete fusion measurements for Li7+Tb159 have been extended to higher energies. The measurements show significant reduction of complete fusion cross sections at above-barrier energies for both the reactions, B10+Tb159 and Li7+Tb159, when compared to those for B11+Tb159. The comparison shows that the extent of suppression of complete fusion cross sections is correlated with the α-separation energies of the projectiles. Also, the two reactions, B10+Tb159 and Li7+Tb159 were found to produce incomplete fusion products at energies near the respective Coulomb barriers, with the α-particle emitting channel being the favoured incomplete fusion process in both the cases

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

    Science.gov (United States)

    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.

  20. Near- and sub-barrier fusion of 6He+40Ar

    International Nuclear Information System (INIS)

    Hinnefeld, J.D.; Kolata, J.J.; Belbot, M.; Lamkin, K.; Zahar, M.; Santi, P.; Kugi, J.

    1993-01-01

    A measurement of the fusion cross section for 6 He + 40 Ar near and below the Coulomb barrier has been performed using a 6 He beam from the UND/Um radioactive beam facility. The 6 He nucleus is thought to have a neutron skin surrounding a 6 He core. If this is the case, then Coulomb polarization of the core relative to the halo might result in neutron flow along a neck, and therefore to a large enhancement of the sub-barrier fusion cross section. 6 He nuclei, of incident energy 10.05 ± 0.44 MeV, were directed into a segmented ionization counter (MUSIC) filled with P10 at 40 torr. The 40 Ar in the detector gas served also as the target nuclei. 6 He energies in the 50-cm active length of the detector varied from 7.75 MeV down to 3.05 MeV. Calculations indicate that fusion events should be distinguishable from most non-fusion events on the basis of energy deposition patterns in the ten MUSIC detector segments. For some large-angle scattering events a more elaborate analysis involving detailed Monte Carlo simulation of the various reactions is necessary

  1. On the existence of and mechanism for microwave-specific reaction rate enhancement.

    Science.gov (United States)

    Dudley, Gregory B; Richert, Ranko; Stiegman, A E

    2015-04-01

    The use of microwave radiation to drive chemical reactions has become ubiquitous in almost all fields of chemistry. In all of these areas it is principally due to rapid and convenient heating resulting in significantly higher rates of reaction, with other advantages including enhanced product selectivity and control of materials properties. Although microwave heating continues to grow as an enabling technology, fundamental research into the nature of microwave heating has not grown at the same rate. In the case of chemical reactions run in homogeneous solution, particularly synthetic organic reactions, there is considerable controversy over the origins of rate enhancement, with a fundamental question being whether there exist microwave-specific effects, distinct from what can be attained under conventional convective heating, that can accelerate a reaction rate. In this Perspective, we discuss unique aspects of microwave heating of molecules in solution and discuss the origin and nature of microwave-specific effects arising from the process of "selective heating" of reactants in solution. Integral to this discussion is work from the field of dielectric relaxation spectroscopy, which provides a model for selective heating by Debye relaxation processes. The Perspective also includes a critical discussion of hypotheses of non-thermal effects (alternatively classified here as resonant processes) and an outline of specific reaction parameters for chemical systems in which microwave-specific Debye relaxation processes can result in observable reaction rate enhancement.

  2. Dynamical fission life-times deduced from gamma-ray emission observed in the fusion-fission reaction : Ne-20 on Bi-209.

    NARCIS (Netherlands)

    vanderPloeg, H; Bacelar, JCS; Buda, A; Dioszegi, [No Value; vantHof, G; vanderWoude, A

    1996-01-01

    The gamma-ray emission spectra between 4 and 20 MeV have been measured for the fusion-fission reactions Ne-20 on Bi-209 --> Np-229* at beam energies 150, 186 and 220 MeV. In addition for the latter experiment the angular dependence of the gamma-ray emission with respect to the spin axis has been

  3. Tritium Aspects of Fueling and Exhaust Pumping in Magnetic Fusion Energy

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, Larry R. [ORNL; Meitner, Steven J. [ORNL

    2017-04-01

    Magnetically confined fusion plasmas generate energy from deuterium-tritium (DT) fusion reactions that produce energetic 3.5 MeV alpha particles and 14 MeV neutrons. Since the DT fusion reaction rate is a strong function of plasma density, an efficient fueling source is needed to maintain high plasma density in such systems. Energetic ions in fusion plasmas are able to escape the confining magnetic fields at a much higher rate than the fusion reactions occur, thus dictating the fueling rate needed. These lost ions become neutralized and need to be pumped away as exhaust gas to be reinjected into the plasma as fuel atoms.The technology to fuel and pump fusion plasmas has to be inherently compatible with the tritium fuel. An ideal holistic solution would couple the pumping and fueling such that the pump exhaust is directly fed back into pellet formation without including impurity gases. This would greatly reduce the processing needs for the exhaust. Concepts to accomplish this are discussed along with the fueling and pumping needs for a DT fusion reactor.

  4. Status of fusion technology

    International Nuclear Information System (INIS)

    Mohan, Ashok

    1978-01-01

    The current status of fusion technology is surveyed. Limited reserves of fossil fuel and dangers of proliferation from nuclear reactors have brought into focus the need to develop an optional energy source. Fusion is being looked upon as an optional energy source which is free from environmental hazards unlike fossil fuels and nuclear reactors. Investments in R and D of fusion energy have increased rapidly in USA, Japan, USSR and European countries. Out of the various fusion fuels known, a mixture of D and T is widely chosen. The main problem in fusion technology is the confinement of plasma for a time sufficient to start the fusion reaction. This can be done magnetically or inertially. The three approaches to magnetic confinement are : (1) tokamak, (2) mirror and (3) pinch. Inertial confinement makes use of lasers or electron beams or ion beams. Both the methods of confinement i.e. magnetic and inertial have problems which are identified and their nature is discussed. (M.G.B.)

  5. The status of cold fusion

    Science.gov (United States)

    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.

  6. Cell fusion by ionizing radiation

    International Nuclear Information System (INIS)

    Khair, M.B.

    1993-08-01

    The relevance and importance of cell fusion are illustrated by the notion that current interest in this phenomenon is shared by scientists in quite varied disciplines. The diversity of cellular membrane fusion phenomena could provoke one to think that there must be a multitude of mechanisms that can account for such diversity. But, in general, the mechanism for the fusion reaction itself could be very similar in many, or even all, cases. Cell fusion can be induced by several factors such as virus Sendai, polyethylene glycol, electric current and ionizing radiation. This article provides the reader with short view of recent progress in research on cell fusion and gives some explanations about fusion mechanisms. This study shows for the first time, the results of the cell fusion induced by ionizing radiations that we have obtained in our researches and the work performed by other groups. (author). 44 refs

  7. Analysis of the synaptotagmin family during reconstituted membrane fusion. Uncovering a class of inhibitory isoforms.

    Science.gov (United States)

    Bhalla, Akhil; Chicka, Michael C; Chapman, Edwin R

    2008-08-01

    Ca(2+)-triggered exocytosis in neurons and neuroendocrine cells is regulated by the Ca(2+)-binding protein synaptotagmin (syt) I. Sixteen additional isoforms of syt have been identified, but little is known concerning their biochemical or functional properties. Here, we assessed the abilities of fourteen syt isoforms to directly regulate SNARE (soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor)-catalyzed membrane fusion. One group of isoforms stimulated neuronal SNARE-mediated fusion in response to Ca(2+), while another set inhibited SNARE catalyzed fusion in both the absence and presence of Ca(2+). Biochemical analysis revealed a strong correlation between the ability of syt isoforms to bind 1,2-dioleoyl phosphatidylserine (PS) and t-SNAREs in a Ca(2+)-promoted manner with their abilities to enhance fusion, further establishing PS and SNAREs as critical effectors for syt action. The ability of syt I to efficiently stimulate fusion was specific for certain SNARE pairs, suggesting that syts might contribute to the specificity of intracellular membrane fusion reactions. Finally, a subset of inhibitory syts down-regulated the ability of syt I to activate fusion, demonstrating that syt isoforms can modulate the function of each other.

  8. Experimental study of the fusion dynamics of 32,34S + 197Au with quasi-elastic scattering

    International Nuclear Information System (INIS)

    Schuck, T.J.; Dasgupta, M.; Timmers, H.

    2000-01-01

    Full text: The fusion dynamics of heavy systems, such as 64 Ni + 208 Pb, leading to the synthesis of super-heavy elements is presently not fully understood. Typical beam energies in such reactions are of the order or smaller than the Coulomb barrier height to minimize the excitation energy of the compound system and increase the survival probability of evaporation residues. It is known that at such energies the relative motion of projectile and target couples to internal degrees of freedom of the system, such as collective motion and particle transfer. This can give rise to a distribution of fusion barriers, which generally leads to an enhancement of the fusion cross-section below the Coulomb barrier. The important role of the individual degrees of freedom can be identified by extracting representations of the barrier distribution from fusion excitation functions. Complementary representations can be obtained from measurements of the quasi-elastic or elastic scattering excitation functions at backward angles. The sensitivity of the representations from scattering is limited to the lower energy part of the barrier distribution, which, however, may contain important signatures of positive Q-value neutron transfer channels. Neutron transfer may be a precursor of neutron flow and neck-formation, which are considered in macroscopic models of the fusion of heavy systems. In order to study the influence of neutron transfer in heavy fusion reactions, quasielastic scattering has been measured for 32 , 34 S + 197 Au at energies spanning the Coulomb barrier. The quasi-elastic yield, including inelastic and transfer reactions, was detected at 165 deg with a Si-surface barrier detector. The excitation functions have been normalized to Rutherford scattering, detected at 30 deg using an existing gas ionisation detector. Representations of the barrier distributions have been extracted and are compared with earlier measurements for 32 S + 208 Pb

  9. Fusion reactor start-up without an external tritium source

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, S., E-mail: Shanliang.Zheng@ccfe.ac.uk; King, D.B.; Garzotti, L.; Surrey, E.; Todd, T.N.

    2016-02-15

    Highlights: • Investigated the feasibility (including plasma physics, neutronics and economics) of starting a fusion reactor from running pure D–D fusion reactor to gradually move towards the D–T operation. • Proposed building up tritium from making use of neutrons generated by D–D fusion reactions. • Studied plasma physics feasibility for pure D–D operation and provided consistent fusion power and neutron yield in the plasma with different mixture of deuterium and tritium. • Discussed the economics aspect for operating a pure D–D fusion reactor towards a full-power D–T fusion reactor. - Abstract: It has long been recognised that the shortage of external tritium sources for fusion reactors using D–T, the most promising fusion fuel, requires all such fusion power plants (FPP) to breed their own tritium. It is also recognised that the initial start-up of a fusion reactor will require several kilograms of tritium within a scenario in which radioactive decay, ITER and subsequent demonstrator reactors are expected to have consumed most of the known tritium stockpile. To circumvent this tritium fuel shortage and ultimately achieve steady-state operation for a FPP, it is essential to first accumulate sufficient tritium to compensate for loss due to decay and significant retention in the materials in order to start a new FPP. In this work, we propose to accumulate tritium starting from D–D fusion reactions, since D exists naturally in water, and to gradually build up the D–T plasma targeted in fusion reactor designs. There are two likely D–D fusion reaction channels, (1) D + D → T + p, and (2) D + D → He3 + n. The tritium can be generated via the reaction channel ‘(1)’ and the 2.45 MeV neutrons from ‘(2)’ react with lithium-6 in the breeding blanket to produce more tritium to be fed back into plasma fuel. Quantitative evaluations are conducted for two blanket concepts to assess the feasibility and suitability of this approach to FPP

  10. Predicting the enhancement of mixing-driven reactions in nonuniform flows using measures of flow topology.

    Science.gov (United States)

    Engdahl, Nicholas B; Benson, David A; Bolster, Diogo

    2014-11-01

    The ability for reactive constituents to mix is often the key limiting factor for the completion of reactions across a huge range of scales in a variety of media. In flowing systems, deformation and shear enhance mixing by bringing constituents into closer proximity, thus increasing reaction potential. Accurately quantifying this enhanced mixing is key to predicting reactions and typically is done by observing or simulating scalar transport. To eliminate this computationally expensive step, we use a Lagrangian stochastic framework to derive the enhancement to reaction potential by calculating the collocation probability of particle pairs in a heterogeneous flow field accounting for deformations. We relate the enhanced reaction potential to three well known flow topology metrics and demonstrate that it is best correlated to (and asymptotically linear with) one: the largest eigenvalue of the (right) Cauchy-Green tensor.

  11. LLL magnetic fusion research: the first 25 years

    International Nuclear Information System (INIS)

    Post, R.F.

    1978-01-01

    From its inception, the Laboratory has supported research directed at tapping controlled fusion. Our magnetic fusion energy program--now one of the major elements of the national fusion energy research effort--dates back to the Laboratory's founding in 1952. This article reviews the program's beginnings, progress, and present status in terms of its ultimate goal: to demonstrate a practical and economical means of generating power from controlled fusion reactions

  12. ACT-XN: Revised version of an activation calculation code for fusion reactor analysis. Supplement of the function for the sequential reaction activation by charged particles

    International Nuclear Information System (INIS)

    Yamauchi, Michinori; Sato, Satoshi; Nishitani, Takeo; Konno, Chikara; Hori, Jun-ichi; Kawasaki, Hiromitsu

    2007-09-01

    The ACT-XN is a revised version of the ACT4 code, which was developed in the Japan Atomic Energy Research Institute (JAERI) to calculate the transmutation, induced activity, decay heat, delayed gamma-ray source etc. for fusion devices. The ACT4 code cannot deal with the sequential reactions of charged particles generated by primary neutron reactions. In the design of present experimental reactors, the activation due to sequential reactions may not be of great concern as it is usually buried under the activity by primary neutron reactions. However, low activation material is one of the important factors for constructing high power fusion reactors in future, and unexpected activation may be produced through sequential reactions. Therefore, in the present work, the ACT4 code was newly supplemented with the calculation functions for the sequential reactions and renamed the ACT-XN. The ACT-XN code is equipped with functions to calculate effective cross sections for sequential reactions and input them in transmutation matrix. The FISPACT data were adopted for (x,n) reaction cross sections, charged particles emission spectra and stopping powers. The nuclear reaction chain data library were revised to cope with the (x,n) reactions. The charged particles are specified as p, d, t, 3 He(h) and α. The code was applied to the analysis of FNS experiment for LiF and Demo-reactor design with FLiBe, and confirmed that it reproduce the experimental values within 15-30% discrepancies. In addition, a notice was presented that the dose rate due to sequential reaction cannot always be neglected after a certain period cooling for some of the low activation material. (author)

  13. Effects of successive critical distances in heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Lee, S.M.; Nakagawa, T.; Matsuse, T.

    1984-01-01

    The concept of Successive Critical Distances is presented. It appears that whether the fusion cross section is limited by compound nucleus or entrance channel properties depends on the degree of asymmetry of the fusing nuclei. Only in the near to symmetry case does the Statistical Yrast Line emerge as a limiting factor. Otherwise, the critical angular momentum for fusion is restricted by a critical distance

  14. What have fusion reactor studies done for you today?

    International Nuclear Information System (INIS)

    Kulchinski, G.L.

    1985-01-01

    The University of Wisconsin examines the fusion program and puts into perspective what return is being made on investments in fusion reactor studies. Illustations show financial support for fusion research from the four major programs, FY'82 expenditures on fusion research, and the total expenditures on fusion research since 1951. Topics discussed include the estimated number of scientists conducting fusion research, the conceptual design study of a fusion reactor, scoping study of a reactor, the chronology of fusion reactor design studies, published fusion reactor studies 1967-1983, conceptual fusion reactor design studies, STARFIRE reference design, MARS central cell, HYLIFE reaction chamber, and selected contributions of reactor design studies to base programs

  15. Nuclear dynamics around the barrier: from fusion to evaporation

    International Nuclear Information System (INIS)

    Simenel, Cedric

    2003-01-01

    This work is devoted to aspects of nuclear dynamics around the barrier. It is shown that for fusion reactions, the Coulomb field couples relative motion of nuclei to rotation of a deformed projectile independently of the energy and the charge of the nuclei. An experimental study of the reaction 6 He + 190 Os via gamma spectroscopy of product nuclei has shown that the break up of the 6 He is coupled to the relative motion too, a strong hindrance resulting in the fusion around and above the fusion barrier. The path to fusion after overcoming the barrier, especially the charge equilibration, have been studied in the framework of the TDHF theory via the preequilibrium GDR excited in N/Z asymmetric reactions. An application to formation of the super-heavy elements has been proposed. Finally, couplings between protons and neutrons have been shown up in mean field calculations. Their main expected effect is an emission of protons under the Coulomb barrier. (author)

  16. Dispersion relation approach to sub-barrier heavy ion fusion reactions

    International Nuclear Information System (INIS)

    Franzin, V.L.M.; Hussein, M.S.

    1986-07-01

    With the aid of an inverse dispersion relation, which gives the imaginary part of the fusion inclusive polarization potential (IPP) in terms of the principal part integral involving the real part of the IPP, the sub-barrier fusion of heavy ions is discussed. The system 16 O+ A Sm is taken as an example. The reactive content of the extracted IPP is analysed within the coupled channels theory. (Author) [pt

  17. Warming up to cold fusion

    International Nuclear Information System (INIS)

    Storms, E.

    1994-01-01

    The idea that tabletop equipment at room temperature could produce nuclear fusion was widely rejected five years ago by the scientific community. Nevertheless, recent results from numerous labs show that a novel phenomena of some kind may indeed be occurring, though theorist are still groping for an explanation. Many aspects of the cold fusion effect are now reproducible if known procedures are used. Palladium, when reacted with enough deuterium, apparently converts to a special condition of matter in which various nuclear reactions--including deuterium-deuterium fusion--can occur despite the repulsive force of the two positive charged nuclei. These reactions can be made to proceed rapidly enough to produce measurable heat. Scientist have published several dozen models, ranging from highly analytical approaches to pictorial representations, to explain these events. Most theories address only the problem of overcoming the coulombic barrier--how it is possible for nuclei to overcome their natural repulsion for each other without an infusion of massive amounts of energy from the outside. None of the proposed explanations accounts for the full range of experimental observations. Nevertheless a workable theory is crucial if we ever hope to apply cold fusion

  18. Fusion reactors and the environment

    International Nuclear Information System (INIS)

    Hancox, R.

    1990-04-01

    Fusion power, based on the nuclear fusion of light elements to yield a net gain of energy, has the potential to extend the world's resources in a way which is environmentally attractive. Nevertheless, the easiest route to fusion - the reaction between deuterium and tritium - involves hazards from the use of tritium and the neutron activation of the structural materials. These hazards have been considered on the basis of simple conceptual reactor designs, both in relation to normal operation and decommissioning and to potential accident situations. Results from several studies are reviewed and suggest that fusion reactors appear to have an inherently lower environmental impact than fission reactors. However, the realization of this potential has yet to be demonstrated. (author)

  19. Nuclear fusion: technology development and achievements

    International Nuclear Information System (INIS)

    Ana, G.; Brad, S.; Lazar, A.; Spiridon, I.; Vijulie, M.

    2009-01-01

    The strategy for reducing the enhanced greenhouse effect, affecting our planet and the increasing energy demand caused by global growth of population, as well, is, certainly, that of adopting, all the three long-term carbon-free options for energy: renewable sources, fission and fusion reactions. All of them should be further explored and developed for the welfare of future generations, thus leaving them the option of a clean and green energy. From all those available options, the fusion is viewed as an energy source that would be effective in solving future demands, referring to the amount of the energy that can be produced taking into account spent fuel to obtain it. The slow (but steady) progress of fusion development linked with the need for large and expensive experimental devices is remarkable; all available technical and scientific information from experiment shows that progress is being made towards a successful reactor (ITER). The desired objective of this intensive research is obtaining of an industrial reactor able to cover energy future requirements. For the construction of this desired reactor, special designs systems are required. The TRF (TRITIUM RECOVERY FACILITY) is one of the installations that have a major importance maintaining an efficient fuel cycle of the reactor in proper function stage. A test model of TRF for implementation in reactor systems, proposed and developed at ICIT Ramnicu Valcea is presented. (authors)

  20. Reaction enhancement of initially distant scalars by Lagrangian coherent structures

    International Nuclear Information System (INIS)

    Pratt, Kenneth R.; Crimaldi, John P.; Meiss, James D.

    2015-01-01

    Turbulent fluid flows have long been recognized as a superior means of diluting initial concentrations of scalars due to rapid stirring. Conversely, experiments have shown that the structures responsible for this rapid dilution can also aggregate initially distant reactive scalars and thereby greatly enhance reaction rates. Indeed, chaotic flows not only enhance dilution by shearing and stretching but also organize initially distant scalars along transiently attracting regions in the flow. To show the robustness of this phenomenon, a hierarchical set of three numerical flows is used: the periodic wake downstream of a stationary cylinder, a chaotic double gyre flow, and a chaotic, aperiodic flow consisting of interacting Taylor vortices. We demonstrate that Lagrangian coherent structures (LCS), as identified by ridges in finite time Lyapunov exponents, are directly responsible for this coalescence of reactive scalar filaments. When highly concentrated filaments coalesce, reaction rates can be orders of magnitude greater than would be predicted in a well-mixed system. This is further supported by an idealized, analytical model that was developed to quantify the competing effects of scalar dilution and coalescence. Chaotic flows, known for their ability to efficiently dilute scalars, therefore have the competing effect of organizing initially distant scalars along the LCS at timescales shorter than that required for dilution, resulting in reaction enhancement

  1. Cathodic current enhancement via manganese and oxygen related reactions in marine biofilms

    Science.gov (United States)

    Strom, Matthew James

    Corrosion is a threat that has economic, and environmental impacts worldwide. Many types of corrosive attack are the subject of ongoing research. One of these areas of research is microbiologically influenced corrosion, which is the enhancement and/or initiation of corrosion events caused by microorganisms. It is well known that colonies of microorganisms can enhance cathodic currents through biofilm formation. The aim of the present work was to elucidate the role of manganese in enhancing cathodic currents in the presence of biofilms. Repeated polarizations conducted in Delaware Bay waters, on biofilm coated Cr identified potentially sustainable reduction reactions. The reduction of MnO2 and the enhancement of the oxygen reduction reaction (ORR) were proven to be factors that influence cathodic current enhancement. The removal of ambient oxygen during polarizations resulted in a shutdown of cathodic current enhancement. These field data led to an exploration of the synergistic relationship between MnO2 and the ORR. Laboratory studies of the catalysis of peroxide disproportionation by MnO2 were monitored using a hanging mercury drop electrode. Experiments were run at an ambient sweater pH of 8 and pH 9, which simulated the near-surface conditions typical of cathodes immersed in seawater. Rapid reoxidation at the more basic pH was shown to allow manganese to behave as a persistent catalyst under the typical electrochemical surface conditions of a cathode. As a result a mechanism for ORR enhancement by manganese was proposed as a unique mechanism for cathodic current enhancement in biofilms. A separate field study of Delaware biofilms on stainless steel coupled to a sacrificial Al anode was carried out to identify the ORR enhancement mechanism and sustainable redox reactions at the cathode. Chemical treatments of glutaraldehyde and formaldoxime were applied to cathodes with biofilms to distinguish between enzymatic and MnO2 related ORR enhancement. The results ruled

  2. Trends in fusion reactor safety research

    International Nuclear Information System (INIS)

    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

  3. Added Value of Contrast-Enhanced Ultrasound on Biopsies of Focal Hepatic Lesions Invisible on Fusion Imaging Guidance.

    Science.gov (United States)

    Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun

    2017-01-01

    To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5-1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making.

  4. Volume navigation with contrast enhanced ultrasound and image fusion for percutaneous interventions: first results.

    Directory of Open Access Journals (Sweden)

    Ernst Michael Jung

    Full Text Available OBJECTIVE: Assessing the feasibility and efficiency of interventions using ultrasound (US volume navigation (V Nav with real time needle tracking and image fusion with contrast enhanced (ce CT, MRI or US. METHODS: First an in vitro study on a liver phantom with CT data image fusion was performed, involving the puncture of a 10 mm lesion in a depth of 5 cm performed by 15 examiners with US guided freehand technique vs. V Nav for the purpose of time optimization. Then 23 patients underwent ultrasound-navigated biopsies or interventions using V Nav image fusion of live ultrasound with ceCT, ceMRI or CEUS, which were acquired before the intervention. A CEUS data set was acquired in all patients. Image fusion was established for CEUS and CT or CEUS and MRI using anatomical landmarks in the area of the targeted lesion. The definition of a virtual biopsy line with navigational axes targeting the lesion was achieved by the usage of sterile trocar with a magnetic sensor embedded in its distal tip employing a dedicated navigation software for real time needle tracking. RESULTS: The in vitro study showed significantly less time needed for the simulated interventions in all examiners when V Nav was used (p<0.05. In the study involving patients, in all 10 biopsies of suspect lesions of the liver a histological confirmation was achieved. We also used V Nav for a breast biopsy (intraductal carcinoma, for a biopsy of the abdominal wall (metastasis of ovarial carcinoma and for radiofrequency ablations (4 ablations. In 8 cases of inflammatory abdominal lesions 9 percutaneous drainages were successfully inserted. CONCLUSION: Percutaneous biopsies and drainages, even of small lesions involving complex access pathways, can be accomplished with a high success rate by using 3D real time image fusion together with real time needle tracking.

  5. Mission to Mars by catalyzed nuclear reactions of the commercialized cold fusion power

    International Nuclear Information System (INIS)

    Woo, Tae Ho

    2016-01-01

    The chemical compound source is deficient to reach to the power as much as the journey to Mars, unless the massive equipment is installed like the nuclear fusion reactor. However, there is very significant limitations of making up the facility due to the propellant power. Therefore, the light and cheap energy source, Low energy nuclear reactions (LENRs), powered rocket has been proposed. In this paper, the power conditions by LENRs are analyzed. After the successful Apollo mission to Moon of the National Aeronautics and Space Administration (NASA) in the U.S. government, the civilian companies have proposed for the manned mission to Mars for the commercial journey purposes. The nuclear power has been a critical issue for the energy source in the travel, especially, by the LENR of LENUCO, Champaign, USA. As the velocity of the rocket increases, the mass flow rate decreases. It could be imaginable to take the reasonable velocity of spacecraft. The energy of the travel system is and will be created for the better one in economical and safe method. There is the imagination of boarding pass for spacecraft ticket shows the selected companies of cold fusion products. In order to solve the limitations of the conventional power sources like the chemical and solar energies, it is reasonable to design LENR concept. Since the economical and safe spacecraft is very important in the long journey on and beyond the Mars orbit, a new energy source, LENR, should be studied much more

  6. Mission to Mars by catalyzed nuclear reactions of the commercialized cold fusion power

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Yonsei University, Wonju (Korea, Republic of)

    2016-05-15

    The chemical compound source is deficient to reach to the power as much as the journey to Mars, unless the massive equipment is installed like the nuclear fusion reactor. However, there is very significant limitations of making up the facility due to the propellant power. Therefore, the light and cheap energy source, Low energy nuclear reactions (LENRs), powered rocket has been proposed. In this paper, the power conditions by LENRs are analyzed. After the successful Apollo mission to Moon of the National Aeronautics and Space Administration (NASA) in the U.S. government, the civilian companies have proposed for the manned mission to Mars for the commercial journey purposes. The nuclear power has been a critical issue for the energy source in the travel, especially, by the LENR of LENUCO, Champaign, USA. As the velocity of the rocket increases, the mass flow rate decreases. It could be imaginable to take the reasonable velocity of spacecraft. The energy of the travel system is and will be created for the better one in economical and safe method. There is the imagination of boarding pass for spacecraft ticket shows the selected companies of cold fusion products. In order to solve the limitations of the conventional power sources like the chemical and solar energies, it is reasonable to design LENR concept. Since the economical and safe spacecraft is very important in the long journey on and beyond the Mars orbit, a new energy source, LENR, should be studied much more.

  7. Use of time-dependent Schroedinger equation to analyze effect of collectivization of valence neutrons on near-barrier nuclear fusion enhancement

    International Nuclear Information System (INIS)

    Zagrebaev, V.I.; ); Samarin, V.V.

    2006-01-01

    Fusion of heavy nuclei was analyzed on the basis of the numerical solution of the Schroedinger three-body and three-dimensional nonstationary equations. One revealed the increase of fuss ion probability in 66 He + 2O Pb reaction caused by transfer and collectivization of valent neutrons [ru

  8. Commissioning of a DT fusion reactor without external supply of tritium

    International Nuclear Information System (INIS)

    Asaoka, Y.; Konishi, S.; Nishio, S.; Hiwatari, R.; Okano, K.; Yoshida, T.; Tomabechi, K.

    2001-01-01

    Commissioning of a DT fusion reactor without external supply of tritium is discussed. The DD reactions in a DT-oriented fusion reactor with external power injection by neutral beams produce tritium and neutrons. Tritium produced by the DD reaction together with that produced in the blanket by the 2.45 MeV neutron is re-circulated into the plasma. Then, the DT reaction rate increases gradually, as tritium concentration in plasma builds up towards the level of nominal operation. Time required to reach the nominal operational condition, i.e. 50 % tritium in plasma, is estimated with assumptions based on a model of fusion power plant. As a result, the start-up period of a DT fusion reactor without external supply of tritium is estimated to be approximately 55 days, with the plasma parameters of CREST having a high performance blanket and tritium processing systems. Major factors to determine the start-up period are DD and DT reaction rates, net tritium breeding gain of the plant and dead inventory in/on facing materials. Elimination of a constraint for fusion reactor deployment and operation without any tritium transportation in and out of plant through its entire life may be possible. (author)

  9. Advanced fuels for nuclear fusion reactors

    International Nuclear Information System (INIS)

    McNally, J.R. Jr.

    1974-01-01

    Should magnetic confinement of hot plasma prove satisfactory at high β (16 πnkT//sub B 2 / greater than 0.1), thermonuclear fusion fuels other than D.T may be contemplated for future fusion reactors. The prospect of the advanced fusion fuels D.D and 6 Li.D for fusion reactors is quite promising provided the system is large, well reflected and possesses a high β. The first generation reactions produce the very active, energy-rich fuels t and 3 He which exhibit a high burnup probability in very hot plasmas. Steady state burning of D.D can ensue in a 60 kG field, 5 m reactor for β approximately 0.2 and reflectivity R/sub mu/ = 0.9 provided the confinement time is about 38 sec. The feasibility of steady state burning of 6 Li.D has not yet been demonstrated but many important features of such systems still need to be incorporated in the reactivity code. In particular, there is a need for new and improved nuclear cross section data for over 80 reaction possibilities

  10. Proceedings of the symposium on the many facets of heavy ion fusion reactions

    International Nuclear Information System (INIS)

    1986-01-01

    The topics of the symposium are sub- and near-barrier fusion, limitations to fusion, compound nucleus decay and spectroscopy, incomplete fusion processes, and fragmentation and liquid-gas phase transition. Separate abstracts were prepared for 54 papers in these proceedings

  11. A Simulation Study for Radiation Treatment Planning Based on the Atomic Physics of the Proton-Boron Fusion Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunmi; Yoon, Do-Kun; Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Kyeong-Hyeon; Jang, Hong-Seok; Suh, Tae Suk [the Catholic University of Korea, Seoul (Korea, Republic of)

    2017-03-15

    The purpose of this research is to demonstrate, based on a Monte Carlo simulation code, the procedure of radiation treatment planning for proton-boron fusion therapy (PBFT). A discrete proton beam (60 - 120 MeV) relevant to the Bragg peak was simulated using a Monte Carlo particle extended (MCNPX, Ver. 2.6.0, National Laboratory, Los Alamos NM, USA) simulation code. After computed tomography (CT) scanning of a virtual water phantom including air cavities, the acquired CT images were converted using the simulation source code. We set the boron uptake regions (BURs) in the simulated water phantom to achieve the proton-boron fusion reaction. Proton sources irradiated the BUR, in the phantom. The acquired dose maps were overlapped with the original CT image of the phantom to analyze the dose volume histogram (DVH). We successfully confirmed amplifications of the proton doses (average: 130%) at the target regions. From the DVH result for each simulation, we acquired a relatively accurate dose map for the treatment. A simulation was conducted to characterize the dose distribution and verify the feasibility of proton boron fusion therapy (PBFT). We observed a variation in proton range and developed a tumor targeting technique for treatment that was more accurate and powerful than both conventional proton therapy and boron-neutron capture therapy.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  13. Astrophysical Nuclear Reaction Rates in the Dense Metallic Environments

    Science.gov (United States)

    Kilic, Ali Ihsan

    2017-09-01

    Nuclear reaction rates can be enhanced by many orders of magnitude in dense and relatively cold astrophysical plasmas such as in white dwarfs, brown dwarfs, and giant planets. Similar conditions are also present in supernova explosions where the ignition conditions are vital for cosmological models. White dwarfs are compact objects that have both extremely high interior densities and very strong local magnetic fields. For the first time, a new formula has been developed to explain cross section and reaction rate quantities for light elements that includes not only the nuclear component but also the material dependence, magnetic field, and crystal structure dependency in dense metallic environments. I will present the impact of the developed formula on the cross section and reaction rates for light elements. This could have possible technological applications in energy production using nuclear fusion reactions.

  14. Evaluation of innovative means of hydrogen risk mitigation in thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Maruejouls, C.

    2003-01-01

    One of the main accidents in ITER-type thermonuclear fusion reactors is the loss of coolant leading to hydrogen production. Within the framework of the studies on the ITER fusion reactor, a mitigation strategy for this risk must be devised by focusing on a system, which can be placed near the hydrogen source. The uncertainty as to the air content during such a scenario forbids the use of classic methods based on the hydrogen/oxygen reaction such as passive catalytic recombiners. Former studies have proposed a process based on the reduction of metallic oxides and more particularly that of the manganese dioxide enhanced by silver oxide mixture. The reaction studied is H 2 + MnO 2 → MnO + H 2 O (reaction enhanced by Ag 2 O). The purpose is to study the kinetic. The method used consists in comparing the experimental results obtained on the pilot facility CIGNE with those provided by a model. The experimental results were obtained from tests made on a pilot facility with a solid/gas reaction in a fixed bed. These underlined the importance of favoring the solid/gas contact surface. The modeling used in the MITRHY simulation program, coupled to an optimizer helped determine the kinetic parameters and the data on the material and temperature transfers. The kinetic is of first order rate for hydrogen with an activation energy of 29428 J/mol and a kinetic coefficient of 142 m.s -1 . Integrated in the MITRHY program, the kinetic parameters were used to simulate the hydrogen elimination in the accident conditions on the ITER experimental reactor. This study achieved a pre-design basis of the device (bed of about 30 cm with grains of a diameter of less than 5 mm) to be implemented. It also underlined the need to favor the specific surface to improved process efficiency. (author)

  15. LLNL nuclear data libraries used for fusion calculations

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1984-01-01

    The Physical Data Group of the Computational Physics Division of the Lawrence Livermore National Laboratory has as its principal responsibility the development and maintenance of those data that are related to nuclear reaction processes and are needed for Laboratory programs. Among these are the Magnetic Fusion Energy and the Inertial Confinement Fusion programs. To this end, we have developed and maintain a collection of data files or libraries. These include: files of experimental data of neutron induced reactions; an annotated bibliography of literature related to charged particle induced reactions with light nuclei; and four main libraries of evaluated data. We also maintain files of calculational constants developed from the evaluated libraries for use by Laboratory computer codes. The data used for fusion calculations are usually these calculational constants, but since they are derived by prescribed manipulation of evaluated data this discussion will describe the evaluated libraries

  16. Correlations between transfer and fusion in heavy ion collisions at the Coulomb barrier

    International Nuclear Information System (INIS)

    Bellwied, R.

    1989-03-01

    For the fusion of heavy atomic nuclei the nuclear-charge product exceeds Z 1 Z 2 =1600 in experiments at the Coulomb barrier a dynamical hindrance was detected. For the study of all binary reaction channels first 86 Kr induced reactions with 76 Ge, 104 Ru, and 130 Te were radiochemically studied. The relative to the fusion still unhindered system Kr+Ge shows beside the fusion only the transfer of few nucleons between projectile and target. In the reactions with Ru and Te (onsetting fusion hindrance) goes indeed a certain part (about 20%) of the missing fusion cross section in reactions with large mass flux, on the other hand however a sudden increasing of the quasi-elastic transfer of few nucleons strikes which fits well into the trend of the literature data for lighter and heavier systems and signalizes a sharply localized correlation between the vanishing of the fusion and the increasing of the transfer. In order to study further this threshold behaviour and to get additional kinematical informations on the binary reaction channels the reactions 96 Zr+ 90 Zr and 124 Sn+ 96 Zr were measured at the magnetic spectrometer of the GSI. With the spectrometer it is contrarily to the radiochemical experiments possible to determine fourfold differential cross section distributions. The sudden increasing of the cross section for quasi-elastic transfer at the threshold for fusion hindrance is completely confirmed whereby from measurements of the energy loss in the exit channel follows that (with lower weight) also complex transfer channels with essential energy damping are formed. By these experiments it has been shown for the first time that the dynamical fusion hindrance already onsets before the collisional partners reach the barrier. (orig./HSI) [de

  17. Heavy-ion accelerator research for inertial fusion

    International Nuclear Information System (INIS)

    1987-08-01

    Thermonuclear fusion offers a most attractive long-term solution to the problem of future energy supplies: The fuel is virtually inexhaustible and the fusion reaction is notably free of long-lived radioactive by-products. Also, because the fuel is in the form of a plasma, there is no solid fuel core that could melt down. The DOE supports two major fusion research programs to exploit these virtues, one based on magnetic confinement and a second on inertial confinement. One part of the program aimed at inertial fusion is known as Heavy Ion Fusion Accelerator Research, or HIFAR. In this booklet, the aim is to place this effort in the context of fusion research generally, to review the brief history of heavy-ion fusion, and to describe the current status of the HIFAR program

  18. Disentangling effects of breakup coupling and incomplete fusion in 6Li + 232Th reaction

    International Nuclear Information System (INIS)

    Jha, V.; Parkar, V.V.; Mohanty, A.K.; Kailas, S.

    2014-01-01

    A component of fusion that is very important but quite difficult to evaluate is the incomplete fusion (ICF), in which only a part of the nucleus fuses with the target. ICF occurs together with the usual complete fusion (CF), in which the whole projectile fuses or all the projectile fragments after breakup fuse with the target nucleus. The ICF leads to the flux removal from the fusion channel and its calculation is essential for a comprehensive description of the fusion process. In the present work, a recently developed method of calculating the ICF cross-section (σ ICF ) is used in a novel way to disentangle the ICF effect on the fusion process from those due to breakup couplings. The total fusion cross-section σ TF and σ ICF for the 6 Li + 232 Th system are calculated at energies above and below the Coulomb barrier, where the measured fusion-fission data is available

  19. Quark-level analogue of nuclear fusion with doubly heavy baryons.

    Science.gov (United States)

    Karliner, Marek; Rosner, Jonathan L

    2017-11-01

    The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm quarks (c) and one up quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm quarks. Here we report that this strong binding enables a quark-rearrangement, exothermic reaction in which two heavy baryons (Λ c ) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4 He n). The much larger binding energy (approximately 280 MeV) between two bottom quarks (b) causes the analogous reaction with bottom quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setups in which the highly exothermic nature of the fusion of two heavy-quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

  20. Overview of fusion reactor safety

    International Nuclear Information System (INIS)

    Cohen, S.; Crocker, J.G.

    1981-01-01

    Use of deuterium-tritium burning fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control, (2) neutron activation of structural materials, fluid streams and reactor hall environment, (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions, (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting magnets and radio frequency heating devices, and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power

  1. Reactions with weakly bound nuclei at near barrier energies

    International Nuclear Information System (INIS)

    Nanal, Vandana

    2014-01-01

    In reactions with weakly bound nuclei, the effect of breakup on fusion process has attracted much attention in recent years. The experimental study shows that breakup channel leads to suppression of complete fusion at above barrier energies due to loss of flux. The fusion barrier distribution can provide a further insight into understanding the influence of coupling to the breakup channels. Similar information could be obtained from the elastic and quasielastic (QEL) scattering because of the conservation of the reaction flux (i.e. R+T= 1), where R is the reflection probability and T is the transmission probability. Thus, quasi-elastic scattering at backward angles is the counterpart of the fusion process and it is expected that the barrier distributions extracted from two processes, namely, QEL and fusion should be similar. While this is true for tightly bound reaction systems, in reactions involving weakly bound projectiles significant differences have been observed for QEL barrier distributions with and without inclusion of breakup processes. This talk will present the recent results for fusion and quasi-elastic scattering in "6","7Li + "1"9"7Au system. Developmental efforts towards a momentum achromatic separator, MARIE, to extract projectile-like secondary ion beams following the reactions of heavy-ion beams from superconducting LINAC booster at Mumbai will also be presented. (author)

  2. Enhancement of isotope exchange reactions over ceramic breeder material by deposition of catalyst metal

    International Nuclear Information System (INIS)

    Narisato, Y.; Munakata, K.; Koga, A.; Yokoyama, Y.; Takata, T.; Okabe, H.

    2004-01-01

    The deposition of catalyst metals in ceramic breeders could enhance the release rate of tritium due to the promotion of isotope exchange reactions taking place at the interface of the breeder surface and the sweep gas. In this work, the authors examined the effects of catalytic active metal deposited on lithium titanate on the isotope exchange reactions. With respect to the virgin lithium titanate, it was found that the rate of the isotope exchange reactions taking place on the surface is quite low. However, the deposition of palladium greatly increased the exchange reaction rate. The effect of the amounts of deposited palladium on the isotope exchange reaction rate was also investigated. The results indicate that the exchange reactions are still enhanced even if the amounts of deposited palladium are as low as 0.04%

  3. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Schultz, K.R.; Smith, A.C. Jr.

    1978-01-01

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

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

    International Nuclear Information System (INIS)

    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)

  5. Fusion Power measurement at ITER

    Energy Technology Data Exchange (ETDEWEB)

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-07-01

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

  6. Enhanced exo-inulinase activity and stability by fusion of an inulin-binding module.

    Science.gov (United States)

    Zhou, Shun-Hua; Liu, Yuan; Zhao, Yu-Juan; Chi, Zhe; Chi, Zhen-Ming; Liu, Guang-Lei

    2016-09-01

    In this study, an inulin-binding module from Bacillus macerans was successfully fused to an exo-inulinase from Kluyveromyces marxianus, creating a hybrid functional enzyme. The recombinant exo-inulinase (rINU), the hybrid enzyme (rINUIBM), and the recombinant inulin-binding module (rIBM) were, respectively, heterologously expressed and biochemically characterized. It was found that both the inulinase activity and the catalytic efficiency (k cat/K m(app)) of the rINUIBM were considerably higher than those of rINU. Though the rINU and the rINUIBM shared the same optimum pH of 4.5, the optimum temperature of the rINUIBM (60 °C) was 5 °C higher than that of the rINU. Notably, the fused IBM significantly enhanced both the pH stability and the thermostability of the rINUIBM, suggesting that the rINUIBM obtained would have more extensive potential applications. Furthermore, the fusion of the IBM could substantially improve the inulin-binding capability of the rINUIBM, which was consistent with the determination of the K m(app). This meant that the fused IBM could play a critical role in the recognition of polysaccharides and enhanced the hydrolase activity of the associated inulinase by increasing enzyme-substrate proximity. Besides, the extra supplement of the independent non-catalytic rIBM could also improve the inulinase activity of the rINU. However, this improvement was much better in case of the fusion. Consequently, the IBM could be designated as a multifunctional domain that was responsible for the activity enhancement, the stabilization, and the substrate binding of the rINUIBM. All these features obtained in this study make the rINUIBM become an attractive candidate for an efficient inulin hydrolysis.

  7. Added value of contrast-enhanced ultrasound on biopsies of focal hepatic lesions invisible on fusion imaging guidance

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-01-15

    To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5–1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p < 0.001). The technical success rate of biopsy was 87.6% (14/16). After biopsy, there were changes in clinical decision making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making.

  8. Added value of contrast-enhanced ultrasound on biopsies of focal hepatic lesions invisible on fusion imaging guidance

    International Nuclear Information System (INIS)

    Kang, Tae Wook; Lee, Min Woo; Song, Kyoung Doo; Kim, Mimi; Kim, Seung Soo; Kim, Seong Hyun; Ha, Sang Yun

    2017-01-01

    To assess whether contrast-enhanced ultrasonography (CEUS) with Sonazoid can improve the lesion conspicuity and feasibility of percutaneous biopsies for focal hepatic lesions invisible on fusion imaging of real-time ultrasonography (US) with computed tomography/magnetic resonance images, and evaluate its impact on clinical decision making. The Institutional Review Board approved this retrospective study. Between June 2013 and January 2015, 711 US-guided percutaneous biopsies were performed for focal hepatic lesions. Biopsies were performed using CEUS for guidance if lesions were invisible on fusion imaging. We retrospectively evaluated the number of target lesions initially invisible on fusion imaging that became visible after applying CEUS, using a 4-point scale. Technical success rates of biopsies were evaluated based on histopathological results. In addition, the occurrence of changes in clinical decision making was assessed. Among 711 patients, 16 patients (2.3%) were included in the study. The median size of target lesions was 1.1 cm (range, 0.5–1.9 cm) in pre-procedural imaging. After CEUS, 15 of 16 (93.8%) focal hepatic lesions were visualized. The conspicuity score was significantly increased after adding CEUS, as compared to that on fusion imaging (p < 0.001). The technical success rate of biopsy was 87.6% (14/16). After biopsy, there were changes in clinical decision making for 11 of 16 patients (68.8%). The addition of CEUS could improve the conspicuity of focal hepatic lesions invisible on fusion imaging. This dual guidance using CEUS and fusion imaging may affect patient management via changes in clinical decision-making

  9. Laser drivers for inertial confinement fusion

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1983-01-01

    Inertial Confinement Fusion (ICF) is the technology that we are developing to access the vast stored energy potential of deuterium fuel located in the world's water supply. This form of fusion is accomplished by compressing and heating small volumes of D-T fuel to very high temperatures (greater than 100M 0 C) and to very high densities (greater than 1000 times the normal liquid density). Under these fuel conditions, a thermonuclear reaction can occur, leading to a net energy release compared to the energy used to heat the fuel initially. To accomplish the condition where fusion reactions begin, effective drivers are required. These are lasers or particle beam accelerators which can provide greater than 10 14 W/cm 2 over millimeter scale targets with an appropriately programmed intensity vs time. At present, we are using research lasers to obtain an understanding of the physics and engineering of fuel compression

  10. Atomic and Plasma-Material Interaction Data for Fusion. V. 16

    International Nuclear Information System (INIS)

    Braams, B.J.; Chung, H.-K.

    2014-03-01

    A wide variety of atomic, molecular, radiative and plasma-wall interaction processes involving a mixture of atoms, ions and molecules occur in the plasmas produced in nuclear fusion experiments. In the low temperature divertor and near wall region, molecules and molecular ions are formed. The plasma particles react with electrons and with each other. Plasma modelling requires cross-sections and rate coefficients for all these processes, and in addition spectral signatures to support interpretation of data from fusion experiments. The mission of the International Atomic Energy Agency Nuclear Data Section (IAEA/NDS) in the area of atomic and molecular data is to enhance the competencies of Member States in their research into nuclear fusion through the provision of internationally recommended atomic, molecular, plasma-material interaction and material properties databases. One mechanism by which the IAEA pursues this mission is the Coordinated Research Project (CRP). The present volume of Atomic and Plasma-Material Interaction Data for Fusion contains contributions from participants in the CRP 'Atomic and Molecular Data for Plasma Modelling' (2004-2008). This CRP was concerned with data for processes in the near wall and divertor plasma and plasma-wall interaction in fusion experiments, with focus on cross-sections for molecular reactions. Participants in the CRP came from 14 different institutes, many with strong ties to fusion plasma modelling and experiment. D. Humbert of the Nuclear Data Section was scientific secretary of the CRP. Participants' contributions for this volume were collected and refereed after the conclusion of the CRP

  11. Coherently enhanced radiation reaction effects in laser-vacuum acceleration of electron bunches

    NARCIS (Netherlands)

    Smorenburg, P.W.; Kamp, L.P.J.; Geloni, G.; Luiten, O.J.

    2010-01-01

    The effects of coherently enhanced radiation reaction on the motion of subwavelength electron bunches in interaction with intense laser pulses are analyzed. The radiation reaction force behaves as a radiation pressure in the laser beam direction, combined with a viscous force in the perpendicular

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

    International Nuclear Information System (INIS)

    Jarmie, N.

    1980-04-01

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

  13. Tore supra: towards the 'long time' fusion. Press journey

    International Nuclear Information System (INIS)

    2008-01-01

    After a recall of the interest in the fusion for the development of energy sources, the document presents the fusion from the solar reaction to the nuclear fusion in laboratory. Then it discusses the great challenges of this technology and the Tore Supra installation. The last part is devoted to ITER and DEMO projects. (A.L.B.)

  14. Public acceptance of fusion energy and scientific feasibility of a fusion reactor. Spin-off effects of fusion research and development

    International Nuclear Information System (INIS)

    Morino, Nobuyuki; Ogawa, Yuichi

    1998-01-01

    It is observed that new and sophisticated technologies developed through research and development in relation to magnetic confinement fusion have been transferred to other industrial and scientific fields with remarkable spin-off effects. Approximately 10 years ago, the Japan Atomic Industrial Forum (JAIF) has investigated technical transfer and spin-off effects of fusion technologies developed in Japan. The essence of the results of this investigation as well as high technologies developed in the last decade, some of which are in the early stage of technical spin-off, are described. It is additionally explained that independent technical development conducted by our country as well as by engineers themselves is important in achieving effective spin-off. An outline of scientific spin-off effects is also described, including utilization technologies of fusion reactions besides those for energy production purposes, the progress of scientific understanding in the course of fusion research, and scientific information transfer and communication with other fields. (author)

  15. Spectator invariance test in the study of the Trojan Horse Method 6,7Li fusion reactions via the Trojan Horse Method

    Directory of Open Access Journals (Sweden)

    Li C.

    2011-10-01

    Full Text Available Fusion reactions play a crucial role for several astrophysical scenarios. At the low energies typical of such environments direct measurements of reaction cross sections are very difficult, and even sometimes impossible. In such cases the use of indirect methods can give a substantial help. The Trojan Horse Method (THM is based on the quasi-free break-up of a nucleus, which can be described in terms of a cluster structure. In such applications the independence of THM results with different break-up schemes, was tested using the quasi free3 He(6Li,ααH and 3He(7Li,αα2H reactions. Results were then compared with the direct behaviours obtained from available data as well as with the cross sections extracted from previous indirect investigations of the same binary reactions using a different nuclide as a Trojan Horse nucleus.

  16. FENDL/C-2.0. Charged-particle reaction data library for fusion applications. Version 1 of March 1997. Data extracted from ENDF/B-6 evaluations. Summary documentation

    International Nuclear Information System (INIS)

    Pashchenko, A.B.; Wienke, H.

    1997-01-01

    This document describes the FENDL/C-2.0 charged-particle reaction data library which is a sublibrary of FENDL-2, the evaluated nuclear data library for fusion applications. This file contains evaluated data in ENDF-6 format for the D(d,n), D(d,p), T(d,n), T(t,2n), He-3(d,p) reactions. The processed information, i.e. Maxwellian-averaged reaction rates, and related quantities, calculated from reaction cross-sections, are also included. The data are available from the Nuclear Data Section online via INTERNET by FTP command, or on magnetic tape upon request. (author)

  17. Fusion peptides from oncogenic chimeric proteins as putative specific biomarkers of cancer.

    Science.gov (United States)

    Conlon, Kevin P; Basrur, Venkatesha; Rolland, Delphine; Wolfe, Thomas; Nesvizhskii, Alexey I; MacCoss, Michael J; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2013-10-01

    Chromosomal translocations encoding chimeric fusion proteins constitute one of the most common mechanisms underlying oncogenic transformation in human cancer. Fusion peptides resulting from such oncogenic chimeric fusions, though unique to specific cancer subtypes, are unexplored as cancer biomarkers. Here we show, using an approach termed fusion peptide multiple reaction monitoring mass spectrometry, the direct identification of different cancer-specific fusion peptides arising from protein chimeras that are generated from the juxtaposition of heterologous genes fused by recurrent chromosomal translocations. Using fusion peptide multiple reaction monitoring mass spectrometry in a clinically relevant scenario, we demonstrate the specific, sensitive, and unambiguous detection of a specific diagnostic fusion peptide in clinical samples of anaplastic large cell lymphoma, but not in a diverse array of benign lymph nodes or other forms of primary malignant lymphomas and cancer-derived cell lines. Our studies highlight the utility of fusion peptides as cancer biomarkers and carry broad implications for the use of protein biomarkers in cancer detection and monitoring.

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

    Science.gov (United States)

    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

  19. Tore supra: towards the 'long time' fusion. Press journey; Tore Supra: vers la fusion 'longue duree'. Voyage de presse

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    After a recall of the interest in the fusion for the development of energy sources, the document presents the fusion from the solar reaction to the nuclear fusion in laboratory. Then it discusses the great challenges of this technology and the Tore Supra installation. The last part is devoted to ITER and DEMO projects. (A.L.B.)

  20. Fusion probability and survivability in estimates of heaviest nuclei production

    International Nuclear Information System (INIS)

    Sagaidak, Roman

    2012-01-01

    A number of theoretical models have been recently developed to predict production cross sections for the heaviest nuclei in fusion-evaporation reactions. All the models reproduce cross sections obtained in experiments quite well. At the same time they give fusion probability values P fus ≡ P CN differed within several orders of the value. This difference implies a corresponding distinction in the calculated values of survivability. The production of the heaviest nuclei (from Cm to the region of superheavy elements (SHE) close to Z = 114 and N = 184) in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing (fusion) model coupled with the standard statistical model (SSM) of the compound nucleus (CN) decay. Both models are incorporated into the HIVAP code. Available data on the excitation functions for fission and evaporation residues (ER) produced in very asymmetric combinations can be described rather well within the framework of HIVAP. Cross-section data obtained in these reactions allow one to choose model parameters quite definitely. Thus one can scale and fix macroscopic (liquid-drop) fission barriers for nuclei involved in the evaporation-fission cascade. In less asymmetric combinations (with 22 Ne and heavier projectiles) effects of fusion suppression caused by quasi-fission are starting to appear in the entrance channel of reactions. The P fus values derived from the capture-fission and fusion-fission cross-sections obtained at energies above the Bass barrier were plotted as a function of the Coulomb parameter. For more symmetric combinations one can deduce the P fus values semi-empirically, using the ER and fission excitation functions measured in experiments, and applying SSM model with parameters obtained in the analysis of a very asymmetric combination leading to the production of (nearly) the same CN, as was done for reactions leading to the pre-actinide nuclei formation

  1. Controlled thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Walstrom, P.L.

    1976-01-01

    Controlled production of energy by fusion of light nuclei has been the goal of a large portion of the physics community since the 1950's. In order for a fusion reaction to take place, the fuel must be heated to a temperature of 100 million degrees Celsius. At this temperature, matter can exist only in the form of an almost fully ionized plasma. In order for the reaction to produce net power, the product of the density and energy confinement time must exceed a minimum value of 10 20 sec m -3 , the so-called Lawson criterion. Basically, two approaches are being taken to meet this criterion: inertial confinement and magnetic confinement. Inertial confinement is the basis of the laser fusion approach; a fuel pellet is imploded by intense laser beams from all sides and ignites. Magnetic confinement devices, which exist in a variety of geometries, rely upon electromagnetic forces on the charged particles of the plasma to keep the hot plasma from expanding. Of these devices, the most encouraging results have been achieved with a class of devices known as tokamaks. Recent successes with these devices have given plasma physicists confidence that scientific feasibility will be demonstrated in the next generation of tokamaks; however, an even larger effort will be required to make fusion power commercially feasible. As a result, emphasis in the controlled thermonuclear research program is beginning to shift from plasma physics to a new branch of nuclear engineering which can be called fusion engineering, in which instrumentation and control engineers will play a major role. Among the new problem areas they will deal with are plasma diagnostics and superconducting coil instrumentation

  2. The existence and characterization of self-sustaining multiplicative fusion and fission reaction chains

    International Nuclear Information System (INIS)

    Harms, A.A.; Heindler, M.

    1980-01-01

    The mathematical-physical similarities and differences between fusion and fission multiplication processes are investigated. It is shown that advanced fusion cycles can sustain excursion tendencies which are essentially analogous to conventional fission cycles. The result that fission excursions are unbounded and that fusion excursions eventually attain an asymptote represents a significant distinction between these fundamental self-sustaining nuclear multiplicative chains. (Auth.)

  3. Theory of nuclear reactions with participation of slow charged particles in solids

    International Nuclear Information System (INIS)

    Barts, B.I.; Barts, D.B.; Grinenko, A.A.

    1992-01-01

    In the last two years, there has been a sharp increase of interest in various aspects of the interaction of nuclear particles in solids. This is due, above all, to the sensational reports of the possibility that deuteron fusion reactions take place at normal temperatures. At the present time, it is clear that, among the various factors, an important role for the understanding of this remarkable phenomenon is played by crystal fields that significantly change the tail of the Coulomb barrier and, thus, its penetrability. Here, in connection with the problem of the cold fusion of deuterons, an analysis is made of the influence of screening of the deuteron charges by electrons of the crystal on the penetrability of the Coulomb barrier. A study is made of the reaction-enhancement method in the case when the deuterons move in the general crystal potential well near one of the minima of the crystal potential

  4. Membrane fusion and exocytosis.

    Science.gov (United States)

    Jahn, R; Südhof, T C

    1999-01-01

    Membrane fusion involves the merger of two phospholipid bilayers in an aqueous environment. In artificial lipid bilayers, fusion proceeds by means of defined transition states, including hourglass-shaped intermediates in which the proximal leaflets of the fusing membranes are merged whereas the distal leaflets are separate (fusion stalk), followed by the reversible opening of small aqueous fusion pores. Fusion of biological membranes requires the action of specific fusion proteins. Best understood are the viral fusion proteins that are responsible for merging the viral with the host cell membrane during infection. These proteins undergo spontaneous and dramatic conformational changes upon activation. In the case of the paradigmatic fusion proteins of the influenza virus and of the human immunodeficiency virus, an amphiphilic fusion peptide is inserted into the target membrane. The protein then reorients itself, thus forcing the fusing membranes together and inducing lipid mixing. Fusion of intracellular membranes in eukaryotic cells involves several protein families including SNAREs, Rab proteins, and Sec1/Munc-18 related proteins (SM-proteins). SNAREs form a novel superfamily of small and mostly membrane-anchored proteins that share a common motif of about 60 amino acids (SNARE motif). SNAREs reversibly assemble into tightly packed helical bundles, the core complexes. Assembly is thought to pull the fusing membranes closely together, thus inducing fusion. SM-proteins comprise a family of soluble proteins that bind to certain types of SNAREs and prevent the formation of core complexes. Rab proteins are GTPases that undergo highly regulated GTP-GDP cycles. In their GTP form, they interact with specific proteins, the effector proteins. Recent evidence suggests that Rab proteins function in the initial membrane contact connecting the fusing membranes but are not involved in the fusion reaction itself.

  5. Fusion barrier distributions - What have we learned?

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    1998-01-01

    The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

  6. Solenoidal fusion system

    International Nuclear Information System (INIS)

    Linlor, W.I.

    1980-01-01

    This invention discloses apparatus and methods to produce nuclear fusion utilizing fusible material in the form of high energy ion beams confined in magnetic fields. For example, beams of deuterons and tritons are injected in the same direction relative to the axis of a vacuum chamber. The ion beams are confined by the magnetic fields of long solenoids. The products of the fusion reactions, such as neutrons and alpha particles, escape to the wall surrounding the vacuum chamber, producing heat. The momentum of the deuterons is approximately equal to the momentum of the tritons, so that both types of ions follow the same path in the confining magnetic field. The velocity of the deuteron is sufficiently greater than the velocity of the triton so that overtaking collisions occur at a relative velocity which produces a high fusion reaction cross section. Electrons for space charge neutralization are obtained by ionization of residual gas in the vacuum chamber, and additionally from solid material (Irradiated with ultra-violet light or other energetic radiation) adjacent to the confinement region. For start-up operation, injected high-energy molecular ions can be dissociated by intense laser beam, producing trapping via change of charge state. When sufficiently intense deuteron and triton beams have been produced, the laser beam can be removed, and subsequent change of charge state can be achieved by collisions

  7. Role of hydrodynamic instability growth in hot-spot mass gain and fusion performance of inertial confinement fusion implosions

    International Nuclear Information System (INIS)

    Srinivasan, Bhuvana; Tang, Xian-Zhu

    2014-01-01

    In an inertial confinement fusion target, energy loss due to thermal conduction from the hot-spot will inevitably ablate fuel ice into the hot-spot, resulting in a more massive but cooler hot-spot, which negatively impacts fusion yield. Hydrodynamic mix due to Rayleigh-Taylor instability at the gas-ice interface can aggravate the problem via an increased gas-ice interfacial area across which energy transfer from the hot-spot and ice can be enhanced. Here, this mix-enhanced transport effect on hot-spot fusion-performance degradation is quantified using contrasting 1D and 2D hydrodynamic simulations, and its dependence on effective acceleration, Atwood number, and ablation speed is identified

  8. Ultradense Nuclear Fusion in Metallic Lithium Liquid. A report on research performed at the R and D Center, Sakaguchi E.H VOC Co. under the auspices of the Swedish Energy Agency

    International Nuclear Information System (INIS)

    Ikegami, Hidetsugu; Pettersson, Roland

    2006-10-01

    This report is concerned with research and development on a new fusion scheme, 'chemonuclear fusion'. In this scheme, lithium or deuterium ions are implanted in liquid lithium whereby huge reaction rate enhancements, as much as up to 10 15 compared to what is expected for a free two-body deuterium-lithium interaction, are obtained. The enhancement is suggested to be a result of nuclear, atomic and chemical reactions taking place cooperatively. Experimental studies on the Li - D chemonuclear fusion is supported financially by the Swedish Energy Agency and were initiated at the Dept. of Analytical Chemistry, Uppsala University. The studies were continued in a collaboration with the R and D Centre, Sakaguchi E.H VOC Co. in Tokyo where a new and modified setup was constructed. Here, besides the Li - D chemonuclear fusion, the Li - Li fusion and the D 2 - 2Li molecular chemonuclear fusion were developed. In 2005 at the R and D Centre, molecular ions D 2 + of energies 30keV were implanted on a surface of metallic Li liquid. Product alpha particles were identified and measured by a single solid state detector. The energies were around 7.6MeV corresponding to what would be expected for the reaction 7 Li + D → 2x 4 He + n. Under some conditions of the Li liquid, the reaction rate was intermittently so high that the particle detector was saturated and stopped counting simultaneously with an appreciable temperature rise in the Li liquid. The results were discussed in March at the University of Tokyo and in October at the Royal Swedish Academy of Sciences, The Royal Swedish Engineering Academy of Sciences and at Uppsala University. This report presents a full description of the results. It also contains more recent results where an additional detector setup, a ΔE-E detector was used for validation of the results in particular the identity of the alpha particles

  9. Inclusion and difusion studies of D in fusion breeding blanket candidate materials

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.

    2015-07-01

    Deuterium-Tritium (D-T) reaction is the most practical fusion reaction on the way to harness fusion energy. As tritium presents trace quantities on Earth [1], tritium fuel is essential to be generated simultaneously with the D-T reaction in a commerical fusion power plant. Tritium can be obtained in the lithium contained breeding blanket as a transmutation product of nuclear reaction 6Li (n, a)T. Li2T iO3 is considered to be one promising candidate solid tritium breeder material, due to its high lithium density, low activation, compatiblity with structure materials and high chemical stability. The tritium generated in Li2T iO3 breeding blanket needs to be collected and recycled back to the fusion reaction. Therefore, the study of the diffusion characteristic of breeder material Li2T iO3 is necessary to determine tritium mobility and tritium extraction efficiency. In order to study tritium release mechanism of Li2T iO3 breeding material in a fusion power plant environment, a fusion like neutron spectrum is essential while it is now not availble in any laboratory. One alternative is using ion accelerator or implantor to get energetic hydrogenic (H,D,T) ions impacting on breeding material, to simulate the tritium distribution situation. Because of the radioactive property of tritium which will complicate processing procedure, another isotope of hydrogen Deuterium is actually used to be studied. The defect structure in Li2T iO3, due to reactor exposure to fusion generated particles and ? ray irradiation, is achieved by energetic Ti ions. SRIM program is implemented to simulate the D ion or Ti ion distributions after bombarding, as well as the defects. X-ray diffraction technique helps to identify phase compositions. Transmission electron microscopy technique is used to observe the microstructures (Author)

  10. Quantum calculation of dipole excitation in fusion reaction

    International Nuclear Information System (INIS)

    Simenel, C.; Chomaz, Ph.; De France, G.

    2000-01-01

    The excitation of the giant dipole resonance by fusion is studied with N/Z asymmetry in the entrance channel. The TDHF solution exhibits a strong dipole vibration which can be associated with a giant vibration along the main axis of a fluctuating prolate shape. The consequences on the gamma-ray emission from hot compound nuclei are discussed. (author)

  11. Recent developments concerning the fusion; Developpements recents sur la fusion

    Energy Technology Data Exchange (ETDEWEB)

    Jacquinot, J. [CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee, DRFC, 13 - Saint Paul lez Durance (France); Andre, M. [CEA/DAM Ile de France, 91 - Bruyeres Le Chatel (France); Aymar, R. [ITER Joint Central Team Garching, Muenchen (Germany)] [and others

    2000-09-04

    Organized the 9 march 2000 by the SFEN, this meeting on the european program concerning the fusion, showed the utility of the exploitation and the enhancement of the actual technology (JET, Tore Supra, ASDEX) and the importance of the Europe engagement in the ITER program. The physical stakes for the magnetic fusion have been developed with a presentation of the progresses in the knowledge of the stability limits. A paper on the inertial fusion was based on the LMJ (Laser MegaJoule) project. The two blanket concepts chosen in the scope of the european program on the tritium blankets, have been discussed. These concepts will be validated by irradiation tests in the ITER-FEAT and adapted for a future reactor. (A.L.B.)

  12. Nuclear fusion an energetic option to the future

    International Nuclear Information System (INIS)

    Medialdea Utande, A.; Sanchez Sanz, J.

    2007-01-01

    Nuclear fusion is the energy source of the Sun and the rest of starts. The great availability of deuterium on Earth, the inherent safety of the reactions involved and the intrinsic environmental respect make fusion an attractive energy source for the future of making of man king. International promising contributions are making Fusion Science and Technology progress by leaps and bounds to achieve its long term goal of cost-effective energy-producing plasmas. (Author)

  13. Measurement of nuclear potentials from fusion excitation functions

    International Nuclear Information System (INIS)

    Huizenga, J.R.; Birkelund, J.R.

    1984-01-01

    The basis for measuring nuclear potentials from fusion excitation functions at energies above barrier is reviewed. It is argued that because of experimental and conceptual problems fusion excitation functions at high energies cannot lead to model independent measurements of internuclear potential at small separations. The Al 27 + Ne 20 reaction previously analyzed by others is used as an example of problems arising from the inability to distinguish complete and incomplete fusion in experimental data

  14. Cold nuclear fusion device

    International Nuclear Information System (INIS)

    Ogino, Shinji.

    1991-01-01

    Selection of cathode material is a key to the attainment of cold nuclear fusion. However, there are only few reports on the cathode material at present and an effective development has been demanded. The device comprises an anode and a cathode and an electrolytic bath having metal salts dissolved therein and containing heavy water in a glass container. The anode is made of gold or platinum and the cathode is made of metals of V, Sr, Y, Nb, Hf or Ta, and a voltage of 3-25V is applied by way of a DC power source between them. The metal comprising V, Sr, Y, Nb, Hf or Ta absorbs deuterium formed by electrolysis of heavy water effectively to cause nuclear fusion reaction at substantially the same frequency and energy efficiency as palladium and titanium. Accordingly, a cold nuclear fusion device having high nuclear fusion generation frequency can be obtained. (N.H.)

  15. Energy by nuclear fusion

    International Nuclear Information System (INIS)

    Buende, R.; Daenner, W.; Herold, H.; Raeder, J.

    1976-12-01

    This report reviews the state of knowledge in a number of fields of fusion research up to autumn 1976. Section 1 gives a very brief presentation of the elementary fusion reactions, the energies delivered by them and the most basic energy balances leading to Lawson-type diagrams. Section 2 outlines the reserves and cost of lithium and deuterium, gives estimates of the total energy available from DT fusion and comments on production technology, availlability and handling of the fuels. In section 3 a survey is given of the different concepts of magnetic confinement (stellarators, tokamaks, toroidal pinches, mirror machines, two-component plasmas), of confinement by walls, gas blankets and imploding liners and, finally, of the concepts of interial confinement (laser fusion, beam fusion). The reactors designed or outlined on the basis of the tokamak, high-β, mirror, and laser fusion concepts are presented in section 4, which is followed in section 5 by a discussion of the key problems of fusion power plants. The present-day knowledge of the cost structure of fusion power plants and the sensitivity of this structure with respect to the physical and technical assumptions made is analysed in section 6. Section 7 and 8 treat the aspects of safety and environment. The problems discussed include the hazard potentials of different designs (radiological, toxicological, and with respect to stored energies), release of radioactivity, possible kinds of malfunctioning, and the environmental impact of waste heat, radiation and radioactive waste (orig.) [de

  16. Enhanced vaccine-induced CD8+ T cell responses to malaria antigen ME-TRAP by fusion to MHC class ii invariant chain.

    Directory of Open Access Journals (Sweden)

    Alexandra J Spencer

    Full Text Available The orthodox role of the invariant chain (CD74; Ii is in antigen presentation to CD4+ T cells, but enhanced CD8+ T cells responses have been reported after vaccination with vectored viral vaccines encoding a fusion of Ii to the antigen of interest. In this study we assessed whether fusion of the malarial antigen, ME-TRAP, to Ii could increase the vaccine-induced CD8+ T cell response. Following single or heterologous prime-boost vaccination of mice with a recombinant chimpanzee adenovirus vector, ChAd63, or recombinant modified vaccinia virus Ankara (MVA, higher frequencies of antigen-specific CD4+ and CD8+ T cells were observed, with the largest increases observed following a ChAd63-MVA heterologous prime-boost regimen. Studies in non-human primates confirmed the ability of Ii-fusion to augment the T cell response, where a 4-fold increase was maintained up to 11 weeks after the MVA boost. Of the numerous different approaches explored to increase vectored vaccine induced immunogenicity over the years, fusion to the invariant chain showed a consistent enhancement in CD8+ T cell responses across different animal species and may therefore find application in the development of vaccines against human malaria and other diseases where high levels of cell-mediated immunity are required.

  17. Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

    Science.gov (United States)

    Parkar, V. V.; Jha, V.; Kailas, S.

    2017-11-01

    We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

  18. Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

    Directory of Open Access Journals (Sweden)

    Parkar V. V.

    2017-01-01

    Full Text Available We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

  19. Atomic and plasma-material interaction data for fusion. V. 7, part B. Particle induced erosion of Be, C and W in fusion plasmas. Part B: Physical sputtering and radiation-enhanced sublimation

    International Nuclear Information System (INIS)

    Eckstein, W.; Stephens, J.A.; Clark, R.E.H.; Davis, J.W.; Haasz, A.A.; Vietzke, E.; Hirooka, Y.

    2001-01-01

    The present volume of Atomic and Plasma-Material Interaction Data for Fusion is devoted to a critical review of the physical sputtering and radiation enhanced sublimation (RES) behaviour of fusion plasma-facing materials, in particular carbon, beryllium and tungsten. The present volume is intended to provide fusion reactor designers a detailed survey and parameterization of existing, critically assessed data for the chemical erosion of plasma-facing materials by particle impact. The survey and data compilation is presented for a variety of materials containing the elements C, Be and W (including dopants in carbon materials) and impacting plasma species. The dependencies of physical sputtering and RES yields on the material temperature, incident projectile energy, and incident flux are considered. The main data compilation is presented as separate data sheets indicating the material, impacting plasma species, experimental conditions, and parameterizations in terms of analytic functions

  20. Neutron dosimetry for radiation damage in fission and fusion reactors

    International Nuclear Information System (INIS)

    Smith, D.L.

    1979-01-01

    The properties of materials subjected to the intense neutron radiation fields characteristic of fission power reactors or proposed fusion energy devices is a field of extensive current research. These investigations seek important information relevant to the safety and economics of nuclear energy. In high-level radiation environments, neutron metrology is accomplished predominantly with passive techniques which require detailed knowledge about many nuclear reactions. The quality of neutron dosimetry has increased noticeably during the past decade owing to the availability of new data and evaluations for both integral and differential cross sections, better quantitative understanding of radioactive decay processes, improvements in radiation detection technology, and the development of reliable spectrum unfolding procedures. However, there are problems caused by the persistence of serious integral-differential discrepancies for several important reactions. There is a need to further develop the data base for exothermic and low-threshold reactions needed in thermal and fast-fission dosimetry, and for high-threshold reactions needed in fusion-energy dosimetry. The unsatisfied data requirements for fission reactor dosimetry appear to be relatively modest and well defined, while the needs for fusion are extensive and less well defined because of the immature state of fusion technology. These various data requirements are examined with the goal of providing suggestions for continued dosimetry-related nuclear data research

  1. Study of multi nucleon transfer in "9","1"1Li + "2"0"8Pb reactions

    International Nuclear Information System (INIS)

    Vinodkumar, A.M.

    2014-01-01

    One of the most active areas of research with radioactive beams is the study of the fusion of weakly bound nuclei, such as the halo nuclei. The central issue is whether the fusion cross section will be enhanced due to the large nuclear size of the halo nucleus or whether fusion-limiting breakup of the weakly bound valence nucleons will lead to a decreased fusion cross section. The fusion of "9","1"1Li with "2"0"8Pb were reported. These measurements were carried out at TRIUMF, Canada. These measurements suggests at above barrier energies, fusion hindrance is taking place in the case of "1"1Li projectile. However, sub barrier fusion measurement need a lower energy measurement. These measurements also suggest need for further measurement of transfer and breakup channels in these reactions. So we suggest a measurement of multi nucleon transfer in the case of "9Li + "2"0"8Pb. Also, these measurement will be able to produce the same nuclei as suggested in the ISOLDE experiment by, where "2"1"2","2"1"4Pb and "2"0"8","2"1"0Hg nuclei for studying the spectroscopy of these nuclei. (author)

  2. Structural and kinetic analysis of the unnatural fusion protein 4-coumaroyl-CoA ligase::stilbene synthase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yechun; Yi, Hankuil; Wang, Melissa; Yu, Oliver; Jez, Joseph M. (WU); (Danforth)

    2012-10-24

    To increase the biochemical efficiency of biosynthetic systems, metabolic engineers have explored different approaches for organizing enzymes, including the generation of unnatural fusion proteins. Previous work aimed at improving the biosynthesis of resveratrol, a stilbene associated a range of health-promoting activities, in yeast used an unnatural engineered fusion protein of Arabidopsis thaliana (thale cress) 4-coumaroyl-CoA ligase (At4CL1) and Vitis vinifera (grape) stilbene synthase (VvSTS) to increase resveratrol levels 15-fold relative to yeast expressing the individual enzymes. Here we present the crystallographic and biochemical analysis of the 4CL::STS fusion protein. Determination of the X-ray crystal structure of 4CL::STS provides the first molecular view of an artificial didomain adenylation/ketosynthase fusion protein. Comparison of the steady-state kinetic properties of At4CL1, VvSTS, and 4CL::STS demonstrates that the fusion protein improves catalytic efficiency of either reaction less than 3-fold. Structural and kinetic analysis suggests that colocalization of the two enzyme active sites within 70 {angstrom} of each other provides the basis for enhanced in vivo synthesis of resveratrol.

  3. An accelerated beam-plasma neutron/proton source and early application of a fusion plasma

    International Nuclear Information System (INIS)

    Ohnishi, M.; Yoshikawa, K.; Yamamoto, Y.; Hoshino, C.; Masuda, K.; Miley, G.; Jurczyk, B.; Stubbers, R.; Gu, Y.

    1999-01-01

    We measured the number of the neutrons and protons produced by D-D reactions in an accelerated beam-plasma fusion and curried out the numerical simulations. The linear dependence of the neutron yield on a discharge current indicates that the fusion reactions occur between the background gas and the fast particles. i.e. charge exchanged neutrals and accelerated ions. The neutron yield divided by (fusion cross section x ion current x neutral gas pressure) still possesses the dependence of the 1.2 power of discharge voltage. which shows the fusion reactions are affected by the electrostatic potential built-up in the center. The measured proton birth profiles suggest the existence of a double potential well, which is supported by the numerical simulations. (author)

  4. Failure rate data for fusion safety and risk assessment

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1993-01-01

    The Fusion Safety Program (FSP) at the Idaho National Engineering Laboratory (INEL) conducts safety research in materials, chemical reactions, safety analysis, risk assessment, and in component research and development to support existing magnetic fusion experiments and also to promote safety in the design of future experiments. One of the areas of safety research is applying probabilistic risk assessment (PRA) methods to fusion experiments. To apply PRA, we need a fusion-relevant radiological dose code and a component failure rate data base. This paper describes the FSP effort to develop a failure rate data base for fusion-specific components

  5. Image fusion for enhanced forest structural assessment

    CSIR Research Space (South Africa)

    Roberts, JW

    2011-01-01

    Full Text Available This research explores the potential benefits of fusing active and passive medium resolution satellite-borne sensor data for forest structural assessment. Image fusion was applied as a means of retaining disparate data features relevant to modeling...

  6. Measurement and analysis of excitation functions and observation of mass-asymmetry effect on incomplete fusion dynamics

    Directory of Open Access Journals (Sweden)

    Rashid M.H.

    2011-10-01

    Full Text Available Excitation functions for sixteen evaporation residues produced in the interaction of 20Ne with 165Ho have been measured in the projectile energy range ≈88-164 MeV, using catcher foil activation technique followed by gamma-ray spectrometry. It has been found in general that the excitation functions of evaporation residues produced via xn/pxn channels satisfactorily reproduced with the statistical model code PACE-2 after subtraction of precursor decay contribution. The significant enhancement in the measured excitation functions for the residues produced in alpha emission channels over the PACE-2 predictions has been observed. These alpha emission channels are attributed to incomplete fusion reaction process. The results indicate the occurrence of incomplete fusion involving break-up of projectile 20Ne into 4He + 16O and /or 8Be + 12C followed by fusion of one of the fragments with target nucleus 165Ho. The analysis of the present data suggest that probability of incomplete fusion increases with projectile energy. The ICF fraction FICF also increases with increasing mass-asymmetry of the entrance channel.

  7. Quantum theory of enhanced unimolecular reaction rates below the ergodicity threshold

    International Nuclear Information System (INIS)

    Leitner, David M.; Wolynes, Peter G.

    2006-01-01

    A variety of unimolecular reactions exhibit measured rates that exceed Rice-Ramsperger-Kassel-Marcus (RRKM) predictions. We show using the local random matrix theory (LRMT) of vibrational energy flow how the quantum localization of the vibrational states of a molecule, by violating the ergodicity assumption, can give rise to such an enhancement of the apparent reaction rate. We present an illustrative calculation using LRMT for a model 12-vibrational mode organic molecule to show that below the ergodicity threshold the reaction rate may exceed many times the RRKM prediction due to quantum localization of vibrational states

  8. Spatial resolution enhancement of satellite image data using fusion approach

    Science.gov (United States)

    Lestiana, H.; Sukristiyanti

    2018-02-01

    Object identification using remote sensing data has a problem when the spatial resolution is not in accordance with the object. The fusion approach is one of methods to solve the problem, to improve the object recognition and to increase the objects information by combining data from multiple sensors. The application of fusion image can be used to estimate the environmental component that is needed to monitor in multiple views, such as evapotranspiration estimation, 3D ground-based characterisation, smart city application, urban environments, terrestrial mapping, and water vegetation. Based on fusion application method, the visible object in land area has been easily recognized using the method. The variety of object information in land area has increased the variation of environmental component estimation. The difficulties in recognizing the invisible object like Submarine Groundwater Discharge (SGD), especially in tropical area, might be decreased by the fusion method. The less variation of the object in the sea surface temperature is a challenge to be solved.

  9. Applications of solid-state nuclear track detectors (SSNTDs) for fast ion and fusion reaction product measurements in TEXTOR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, A.; Malinowski, K.; Malinowska, A. [Association EURTOM-IPPLM Warsaw, The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Wassenhove, G. Van [EURATOM-Belgium State Association, LPP, ERM/KMS, Trilateral Euregio Cluster, B-1000 Brussels (Belgium); Schweer, B. [Association EURATOM-FZJ, Institutte of Plasma Physicx, Juelich (Germany)

    2011-07-01

    Full text of publication follows: The paper reports on measurements of fusion reaction protons which were performed on TEXTOR facility in January 2009. The basic experimental scheme was similar to that applied in the previous measurements [1, 2]. The main experimental tool equipment was a small ion pinhole camera which was equipped with a PM-355 detector sample and was attached to a water cooled manipulator. The camera was placed below the plasma ring in the direction of ion drifts, at a distance of 4.4 cm from LCFS. However, in the described experiment it was aligned at an angle to the mayor TEXTOR radius (contrary to previous experiments), so that the input pinhole was oriented first at {gamma} = 45 degrees (shots 108799 - 108818) and then {gamma} = 600 (shots 108832 - 108847). The discharges were executed with one neutral beam of the total power 0.6 - 1.0 MW. In the first series (Nos 108799 - 108818) the plasma was additionally heated by ICRH of frequency 38 MHz. The irradiated detector samples were subjected to the same interrupted etching procedure as the samples used in the CR-39/PM-355 detector calibration measurements [1, 2]. After that, track density distributions and track diameter histograms were measured under an optical microscope. By the use of the calibration curves, it was possible to distinguish craters produced by protons from other craters and to convert the obtained histograms into proton energy spectra. The craters induced by lower energy ions appeared to be concentrated in narrower areas, whereas higher energy ions were registered in a more diffused detector fields. The paper shows again that the CR-39/PM-355 detector is an useful diagnostic tool for tokamak experiments, for measurement of charged ions. References: [1] A. Szydlowski, A. Malinowska, M. Jaskola, A. Korman, M.J. Sadowski, G. Van Wassenhove, B. Schweer and the TEXTOR team, A. Galkowski, 'Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements

  10. Fusion-fission dynamics and perspectives of future experiments

    International Nuclear Information System (INIS)

    Zagrebaev, V.I.; Itkis, M.G.; Oganessian, Yu.Ts.

    2003-01-01

    The paper is focused on reaction dynamics of superheavy-nucleus formation and decay at beam energies near the Coulomb barrier. The aim is to review the things we have learned from recent experiments on fusion-fission reactions leading to the formation of compound nuclei with Z ≥ 102 and from their extensive theoretical analysis. Major attention is paid to the dynamics of formation of very heavy compound nuclei taking place in strong competition with the process of fast fission (quasifission). The choice of collective degrees of freedom playing a fundamental role and finding the multidimensional driving potential and the corresponding dynamic equation regulating the whole process are discussed. A possibility of deriving the fission barriers of superheavy nuclei directly from performed experiments is of particular interest here. In conclusion, the results of a detailed theoretical analysis of available experimental data on the 'cold' and 'hot' fusion-fission reactions are presented. Perspectives of future experiments are discussed along with additional theoretical studies in this field needed for deeper understanding of the fusion-fission processes of very heavy nuclear systems

  11. Microscopic observations of palladium used for cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1991-01-01

    This paper examines the microscopic structures of palladium metals used for cold fusion experiments. Tiny spot defects suggesting cold fusion have been observed in grain boundaries as the Nattoh model predicts. The relationship between these defects and a series of neutron busts and an indirect loop of hydrogen chain reactions are discussed

  12. Fusion energy for the 21st century

    International Nuclear Information System (INIS)

    Harris, J.H.

    1999-01-01

    Fusion reactions like those that power the stars have the potential of providing bulk electricity generation with reduced emissions and low radioactive hazard, but pose many challenges in physics and technology. The H-1 Heliac Major National Research Facility now being developed offers Australian scientists and engineers an opportunity to participate in the collaborative international fusion research program. Work on H-1NF contributes not only to the realisation of fusion power, but offers the stimulus and opportunity for advanced training and the development of spin-off technology

  13. Measurements of fusion cross sections in the systems {sup 58,64}Ni +, {sup 78,86}Kr

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

    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.

  14. ROK-PRC Cooperation on Laser Fusion Energy

    International Nuclear Information System (INIS)

    Rhee, Yong Joo; Han, J. M.; Lee, S. M.; Nam, S. M.; Kwan, D. H.; Cha, Y. H.; Baek, S. H.

    2009-03-01

    International treaties on the reduction of green-house gases are now being established worldwide and Korea is supposed to join these treaties in a near future. Meanwhile the energy production via fission reactors proposed as a solution to this global environmental contamination has still inherent problems in that it also produces long-life radioactive nuclear waste in the long run, causing many serious social issues. Now the ultimate solution in this situation is believed to be the production of energy by the nuclear fusion reaction. In this project, the collaboration regarding high energy laser fusion has been carried out mainly at the Chinese facility such as ShengGuang II (SG II) laser facility, and ultrahigh intensity laser system of KAERI has been used for the small scale laser fusion and production of fast neutrons. Thomson scattering experiment to analyze the fusion plasma, opacity measurement to understand and develop the computer simulation techniques have been carried out at SG II facility, and experiments on implosion reaction which is basic to laser fusion as well as that of X-ray absorption and transmission have been done at the GEKKO XII facility of ILE, Japan. Satisfactory results both for Korea and China have been deduced by the strategy of project such that different approaches for high energy laser fusion and low energy laser fusion were applied. That is, Korean partner could get opportunities of doing experiments at the large laser facilities to get plasma diagnostic technologies and high density simulation technologies, besides the opportunity to participate in the K-C-J collaborative experiments of implosion and X-ray spectroscopy. And Chinese partner could solve their problem related to the laser fusion and neutron generation which were not successful even with their far high 300TW laser system

  15. Unexpected heterogeneity of BCR-ABL fusion mRNA detected by polymerase chain reaction in Philadelphia chromosome-positive acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Hooberman, A.L.; Carrino, J.J.; Leibowitz, D.; Rowley, J.D.; Le Beau, M.M.; Arlin, Z.A.; Westbrook, C.A.

    1989-01-01

    The Philadelphia (Ph 1 ) chromosome results in a fusion of portions of the BCR gene from chromosome 22 and the ABL gene from chromosome 9, producing a chimeric BCR-ABL mRNA and protein. In lymphoblastic leukemias, there are two molecular subtypes of the Ph 1 chromosome, one with a rearrangement of the breakpoint cluster region (bcr) of the BCR gene, producing the same 8.5-kilobase BCR-ABL fusion mRNA seen in chronic myelogenous leukemia (CML), and the other, without a bcr rearrangement, producing a 7.0-kilobase BCR-ABL fusion mRNA that is seen only in acute lymphoblastic leukemia (ALL). The authors studied the molecular subtype of the Ph 1 chromosome in 11 cases of Ph 1 -positive ALL, including 2 with a previous diagnosis of CML, using a sensitive method to analyze the mRNA species based on the polymerase chain reaction (PCR). They observed unexpected heterogeneity in BCR-ABL mRNA in this population. They conclude that the PCR gives additional information about the Ph 1 chromosome gene products that cannot be obtained by genomic analysis, but that it cannot be used as the sole means of detection of this chromosomal abnormality in ALL because of the high incidence of false negative results

  16. Study of charged fusion products in laser produced plasmas

    International Nuclear Information System (INIS)

    Rosenblum, M.

    1981-07-01

    Charged reaction products play a central role in inertial confinement fusion. The investigation of the various processes these particles undergo in laser produced plasmas, their influence on the dynamics of the fusion and their utilization as a diagnostic tool are the main subjects of this thesis. (author)

  17. Aldimine Formation Reaction, the First Step of the Maillard Early-phase Reaction, Might be Enhanced in Variant Hemoglobin, Hb Himeji.

    Science.gov (United States)

    Koga, Masafumi; Inada, Shinya; Shimizu, Sayoko; Hatazaki, Masahiro; Umayahara, Yutaka; Nishihara, Eijun

    2015-01-01

    Hb Himeji (β140Ala→Asp) is known as a variant hemoglobin in which glycation is enhanced and HbA1c measured by immunoassay shows a high value. The phenomenon of enhanced glycation in Hb Himeji is based on the fact that the glycation product of variant hemoglobin (HbX1c) shows a higher value than HbA1c. In this study, we investigated whether aldimine formation reaction, the first step of the Maillard early-phase reaction, is enhanced in Hb Himeji in vitro. Three non-diabetic subjects with Hb Himeji and four non-diabetic subjects without variant hemoglobin were enrolled. In order to examine aldimine formation reaction, whole blood cells were incubated with 500 mg/dl of glucose at 37°C for 1 hour and were analyzed by high-performance liquid chromatography. Both HbA1c and HbX1c were not increased in this condition. After incubation with glucose, labile HbA1c (LA1c) fraction increased in the controls (1.1±0.3%). In subjects with Hb Himeji increases in the labile HbX1c (LX1c) fraction as well as the LA1c fraction were observed, and the degree of increase in the LX1c fraction was significantly higher than that of the LA1c fraction (1.8±0.1% vs. 0.5±0.2%, Preaction might be enhanced in Hb Himeji in vitro. The 140th amino acid in β chain of hemoglobin is suggested to be involved in aldimine formation reaction. © 2015 by the Association of Clinical Scientists, Inc.

  18. Programmable fusion of liposomes mediated by lipidated PNA

    DEFF Research Database (Denmark)

    Rabe, A; Löffler, P M G; Ries, O

    2017-01-01

    We recently reported a DNA-programmed fusion cascade enabling the use of liposomes as nanoreactors for compartmentalized chemical reactions. This communication reports an alternative and robust strategy based on lipidated peptide nucleic acids (LiPs). LiPs enabled fusion of liposomes with remarka...... with remarkable 31% efficiency at 50 °C with low leakage (5%)....

  19. Fusion17 summary talk: windsurfing on a cross section profile

    Directory of Open Access Journals (Sweden)

    Ackermann Dieter

    2017-01-01

    Full Text Available The spectrum of physics, discussed in the 7th edition of the “Fusion” conference series, included a number of topics, ranging from reaction dynamics to structure studies, from the lightest to the heaviest nuclei, from inelastic reactions to fusion and fission, with applications of astrophysical interest and the newest developments and findings in theory and experiment. With this paper we try to summarize the most relevant issues discussed during the five days of Fusion17.

  20. Prospects for developing attractive inertial fusion concepts

    International Nuclear Information System (INIS)

    Cornwall, T.; Bodner, S.; Herrmannsfeldt, W.B.; Hogan, W.; Storm, E.; VanDevender, J.P.

    1986-01-01

    The authors discuss the role of inertial fusion in relationship to defense activities as well as in relation to energy alternatives. Other general advantages to inertial fusion besides maintaining the system more cheaply and easily, are discussed such as certain designs and the use of very short wavelength with a very modest laser intensity. A discussion on the direct illumination approach is offered. The progress made in high-gain target physics and the potential for development of solid-state lasers as a potential multimegajoule driver and a potential high-rep-rate fusion driver are discussed. Designs for reaction chambers are examined, as is the heavy-ion fusion program. Light-ion accelerators are also discussed

  1. Fusion Safety Program annual report, fiscal year 1992

    International Nuclear Information System (INIS)

    Holland, D.F.; Cadwallader, L.C.; Herring, J.S.; Longhurst, G.R.; McCarthy, K.A.; Merrill, B.J.; Piet, S.J.

    1993-01-01

    This report summarizes the major activities of the Fusion Safety Program in fiscal year 1992. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory and EG ampersand G Idaho, Inc. is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL and in participating organizations including the Westinghouse Hanford Company at the Hanford Engineering Development Laboratory, the Massachusetts Institute of Technology, and the University of Wisconsin. The technical areas covered in the report include tritium safety, activation product release, reactions involving beryllium, reactions involving lithium breeding materials, safety of fusion magnet systems, plasma disruptions, risk assessment failure rate data base, and computer code development for reactor transients. Also included in the report is a summary of the safety and environmental studies performed by the INEL for the Tokamak Physics Experiments and the Tokamak Fusion Test Reactor, the safety analysis for the International Thermonuclear Experimental Reactor design, and the technical support for the ARIES commercial reactor design study

  2. Cluster dynamics transcending chemical dynamics toward nuclear fusion.

    Science.gov (United States)

    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.

  3. Controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Trocheris, M.

    1975-01-01

    An outline is given of the present position of research into controlled fusion. After a brief reminder of the nuclear reactions of fusion and the principle of their use as a source of energy, the results obtained by the method of magnetic confinement are summarized. Among the many solutions that have been imagined and tried out to achieve a magnetic containing vessel capable of holding the thermonuclear plasma, the devices of the Tokamak type have a good lead and that is why they are described in greater detail. An idea is then given of the problems that arise when one intends conceiving the thermonuclear reactor based on the principle of the Tokamaks. The last section deals with fusion by lasers which is a new and most attractive alternative, at least from the viewpoint of basis physics. The report concludes with an indication of the stages to be passed through to reach production of energy on an industrial scale [fr

  4. The Role of the JET Project in Global Fusion Research

    DEFF Research Database (Denmark)

    Jensen, Vagn Orla

    1983-01-01

    The aim of nuclear fusion research is to make fusion energy available as a new energy source. Fusion processes occur naturally in the sun, where hydrogen nuclei release energy by combining to form helium. A fusion reactor on earth will require even higher temperatures than in the interior...... of the sun, and it will be based on deuterium and tritium reactions. JET (Joint European Torus) is a major fusion experiment now under construction near Abingdon in the UK It is aimed at producing conditions approximating those necessary in a fusion reactor. The results expected from JET should permit...... a realistic evaluation of the prospects for fusion power and serve as a basis for the design of the next major fusion experiment....

  5. Chloroquine Increases Glucose Uptake via Enhancing GLUT4 Translocation and Fusion with the Plasma Membrane in L6 Cells

    Directory of Open Access Journals (Sweden)

    Qi Zhou

    2016-05-01

    Full Text Available Background/Aims: Chloroquine can induce an increase in the cellular uptake of glucose; however, the underlying mechanism is unclear. Methods: In this study, translocation of GLUT4 and intracellular Ca2+ changes were simultaneously observed by confocal microscope in L6 cells stably over-expressing IRAP-mOrange. The GLUT4 fusion with the plasma membrane (PM was traced using HA-GLUT4-GFP. Glucose uptake was measured using a cell-based glucose uptake assay. GLUT4 protein was detected by Western blotting and mRNA level was detected by RT-PCR. Results: We found that chloroquine induced significant increases in glucose uptake, glucose transporter GLUT4 translocation to the plasma membrane (GTPM, GLUT4 fusion with the PM, and intracellular Ca2+ in L6 muscle cells. Chloroquine-induced increases of GTPM and intracellular Ca2+ were inhibited by Gallein (Gβγ inhibitor and U73122 (PLC inhibitor. However, 2-APB (IP3R blocker only blocked the increase in intracellular Ca2+ but did not inhibit GTPM increase. These results indicate that chloroquine, via the Gβγ-PLC-IP3-IP3R pathway, induces elevation of Ca2+, and this Ca2+ increase does not play a role in chloroqui-ne-evoked GTPM increase. However, GLUT4 fusion with the PM and glucose uptake were significantly inhibited with BAPTA-AM. This suggests that Ca2+ enhances GLUT4 fusion with the PM resulting in glucose uptake increase. Conclusion: Our data indicate that chloroquine via Gβγ-PLC-IP3-IP3R induces Ca2+ elevation, which in turn promotes GLUT4 fusion with the PM. Moreover, chloroquine can enhance GLUT4 trafficking to the PM. These mechanisms eventually result in glucose uptake increase in control and insulin-resistant L6 cells. These findings suggest that chloroquine might be a potential drug for improving insulin tolerance in diabetic patients.

  6. Light particle emission in light heavy-ion induced reactions

    International Nuclear Information System (INIS)

    Bozek, E.; Cassagnou, Y.; Dayras, R.

    1982-01-01

    A detailed study was made of the different processes which may compete with fusion in the energy domain where the cross section for fusion deviates from the reaction cross section. Both reactions 14 N + 12 C and 16 O + 10 B were used to form the compound nucleus 26 Al at the same excitation energy of 44 MeV

  7. On the energy gain enhancement of DT+D3He fuel configuration in nuclear fusion reactor driven by heavy ion beams

    Directory of Open Access Journals (Sweden)

    S Khoshbinfar

    2016-09-01

    Full Text Available It is expected that advanced fuels be employed in the second generation of nuclear fusion reactors. Theoretical calculations show that in such a fuel, a high plasma temperature about 100 keV is a requisite for reaction rate improvement of nuclear fusion. However, creating such a temporal condition requires a more powerful driver than we have today. Here, introducing an optimal fuel configuration consisting of DT and D-3He layers, suitable for inertial fusion reactors and driven by heavy ion beams, the optimal energy gain conditions have been simulated and derived for 1.3 MJ system. It was found that, in this new fuel configuration, the ideal energy gain, is 22 percent more comparing with energy gain in corresponding single DT fuel layer. Moreover, the inner DT fuel layer contributed as an ignition trigger, while the outer D3He fuel acts as particle and radiation shielding as well as fuel layer.

  8. Suppression of the stellar enhancement factor and the reaction 85Rb(p,n)85Sr

    International Nuclear Information System (INIS)

    Rauscher, T.; Kiss, G. G.; Gyuerky, Gy.; Simon, A.; Fueloep, Zs.; Somorjai, E.

    2009-01-01

    It is shown that a Coulomb suppression of the stellar enhancement factor occurs in many endothermic reactions at and far from stability. Contrary to common assumptions, reaction measurements for astrophysics with minimal impact of stellar enhancement should be preferably performed for those reactions instead of their reverses, despite of their negative Q value. As a demonstration, the cross section of the astrophysically relevant 85 Rb(p,n) 85 Sr reaction has been measured by activation between 2.16≤E c.m. ≤3.96 MeV and the astrophysical reaction rates at p process temperatures for (p,n) as well as (n,p) are directly inferred from the data. Additionally, our results confirm a previously derived modification of a global optical proton potential. The presented arguments are also relevant for other α- and proton-induced reactions in the p, rp, and νp processes.

  9. Single-flux-quantum logic circuits exploiting collision-based fusion gates

    International Nuclear Information System (INIS)

    Asai, T.; Yamada, K.; Amemiya, Y.

    2008-01-01

    We propose a single-flux-quantum (SFQ) logic circuit based on the fusion computing systems--collision-based and reaction-diffusion fusion computers. A fusion computing system consists of regularly arrayed unit cells (fusion gates), where each unit has two input arms and two output arms and is connected to its neighboring cells with the arms. We designed functional SFQ circuits that implemented the fusion computation. The unit cell was able to be made with ten Josephson junctions. Circuit simulation with standard Nb/Al-AlOx/Nb 2.5-kA/cm 2 process parameters showed that the SFQ fusion computing systems could operate at 10 GHz clock

  10. Fusion probability and survivability in estimates of heaviest nuclei production

    Directory of Open Access Journals (Sweden)

    Sagaidak Roman N.

    2012-02-01

    Full Text Available Production of the heavy and heaviest nuclei (from Po to the region of superheavy elements close to Z=114 and N=184 in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing model coupled with the statistical model (SM of de-excitation of a compound nucleus (CN. Excitation functions for fission and evaporation residues (ER measured in very asymmetric combinations can be described rather well. One can scale and fix macroscopic (liquid-drop fission barriers for nuclei involved in the calculation of survivability with SM. In less asymmetric combinations, effects of fusion suppression caused by quasi-fission (QF are starting to appear in the entrance channel of reactions. QF effects could be semi-empirically taken into account using fusion probabilities deduced as the ratio of measured ER cross sections to the ones obtained in the assumption of absence of the fusion suppression in corresponding reactions. SM parameters (fission barriers obtained at the analysis of a very asymmetric combination leading to the production of (nearly the same CN should be used for this evaluation.

  11. Application of Fusion Gyrotrons to Enhanced Geothermal Systems (EGS)

    Science.gov (United States)

    Woskov, P.; Einstein, H.; Oglesby, K.

    2013-10-01

    The potential size of geothermal energy resources is second only to fusion energy. Advances are needed in drilling technology and heat reservoir formation to realize this potential. Millimeter-wave (MMW) gyrotrons and related technologies developed for fusion energy research could contribute to enabling EGS. Directed MMW energy can be used to advance rock penetration capabilities, borehole casing, and fracking. MMWs are ideally suited because they can penetrate through small particulate extraction plumes, can be efficiently guided long distances in borehole dimensions, and continuous megawatt sources are commercially available. Laboratory experiments with a 10 kW, 28 GHz CPI gyrotron have shown that granite rock can be fractured and melted with power intensities of about 1 kW/cm2 and minute exposure times. Observed melted rock MMW emissivity and estimated thermodynamics suggest that penetrating hot, hard crystalline rock formations may be economic with fusion research developed MMW sources. Supported by USDOE, Office of Energy Efficiency and Renewable Energy and Impact Technologies, LLC.

  12. Studies of 4He emission in both fusion-like and inelastic reactions of 340-MeV 40Ar + 238U

    International Nuclear Information System (INIS)

    Kildir, M.; Logan, D.; Kaplan, M.; Zisman, M.S.; Guerreau, D.; Alexander, J.M.; Vaz, L.C.

    1982-01-01

    The fission-fragment angular correlation technique has been used in conjunction with a position-sensitive avalanche detector to identify the fusion-like and inelastic collisions of 340-MeV 40 Ar + 238 U. For each of these two reaction types, we have characterized the correlated 4 He emission by measuring three-fold coincidences between two fission fragments and the light charged particle. We find an abundance of both evaporation-like and direct 4 He emission, each of which is associated with both fusion-fission and sequential-fission processes. Several comparison tests of both the coincidence and singles data strongly indicate that very little 4 He emission is due to evaporation from accelerated fission fragments in this system. The evaporative 4 He emission appears instead to have a strong contribution originating from the composite system prior to fission. The forward angle 4 He emissions, characterized by prominent forward-peaking and relatively high energies, suggest an origin associated with the very early stages of the collision

  13. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    International Nuclear Information System (INIS)

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG 2a rather than IgG 1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8 + T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  14. Fusion Materials Irradiation Test Facility: a facility for fusion-materials qualification

    International Nuclear Information System (INIS)

    Trego, A.L.; Hagan, J.W.; Opperman, E.K.; Burke, R.J.

    1983-01-01

    The Fusion Materials Irradiation Test Facility will provide a unique testing environment for irradiation of structural and special purpose materials in support of fusion power systems. The neutron source will be produced by a deuteron-lithium stripping reaction to generate high energy neutrons to ensure damage similar to that of a deuterium-tritium neutron spectrum. The facility design is now ready for the start of construction and much of the supporting lithium system research has been completed. Major testing of key low energy end components of the accelerator is about to commence. The facility, its testing role, and the status and major aspects of its design and supporting system development are described

  15. Controlled nuclear fusion apparatus

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, B.

    1982-01-01

    A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to bootstrap the device to a region of high temperatures and high densities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time. A series of potentially disposable and replaceable central core regions are disclosed for a large-scale economical electrical power generating plant

  16. What can we learn about heavy ion fusion by studying fission angular distributions

    International Nuclear Information System (INIS)

    Back, B.B.

    1984-01-01

    Determinations of complete fusion reactions leading to fissionable systems are associated with problems of separating fragments from quasi-fission reactions from those arising from fission of the completely fused system. Inferring complete fusion cross sections from the minute cross sections for the evaporation residue channel is hampered by the insufficient knowledge of the branching ratio for neutron emission and fission in the decay sequence of the completely fused system. From a quantitative analysis of the fragment angular distributions it is, however, possible under certain assumptions to deduce the relative contribution of complete fusion and quasi-fission. It is found that the complete fusion process is hindered for heavy projectiles. The excess radial energy over the interaction barrier needed to induce fusion with heavy projectiles is determined in several cases and systematic trends are presented

  17. International fusion research

    International Nuclear Information System (INIS)

    Pease, R.S.

    1983-01-01

    Nuclear energy of the light elements deuterium and lithium can be released if the 100 MK degree temperature required for deuterium-tritium thermonuclear fusion reactions can be achieved together with sufficient thermal insulation for a net energy yield. Progress of world-wide research shows good prospect for these physical conditions being achieved by the use of magnetic field confinement and of rapidly developing heating methods. Tokamak systems, alternative magnetic systems and inertial confinement progress are described. International co-operation features a number of bilateral agreements between countries: the Euratom collaboration which includes the Joint European Torus, a joint undertaking of eleven Western European nations of Euratom, established to build and operate a major confinement experiment; the development of co-operative projects within the OECD/IEA framework; the INTOR workshop, a world-wide study under IAEA auspices of the next major step in fusion research which might be built co-operatively; and assessments of the potential of nuclear fusion by the IAEA and the International Fusion Research Council. The INTOR (International Tokamak Reactor) studies have outlined a major plant of the tokamak type to study the engineering and technology of fusion reactor systems, which might be constructed on a world-wide basis to tackle and share the investment risks of the developments which lie ahead. This paper summarizes the recent progress of research on controlled nuclear fusion, featuring those areas where international co-operation has played an important part, and describes the various arrangements by which this international co-operation is facilitated. (author)

  18. Systematic analysis of above-barrier fusion of 9,10,11Be+209Bi

    International Nuclear Information System (INIS)

    Hinde, D. J.; Dasgupta, M.

    2010-01-01

    Measurements of fusion for 9,10,11 Be allow testing of the relative importance to fusion and breakup of the α-cluster structure found in all these Be isotopes, compared with the neutron-halo structure only present for 11 Be. However, disagreements exist among different published experimental data sets for the reactions of 9,10,11 Be with 209 Bi. Accurate measurements of above-barrier cross sections for the products of complete fusion (fission and evaporation residues) in the reaction of 9 Be with 209 Bi and 208 Pb provide the basis for a reanalysis of above-barrier fusion for 10,11 Be+ 209 Bi. This includes procedures making full use of the higher precision stable beam data and resolves many of the disagreements. The improved self-consistency of the analysis allows investigation of the experimental average fusion barriers. Although showing some scatter, these suggest a higher barrier for the neutron halo nucleus 11 Be. Comparison of published cross sections for fusion associated with capture of all the charge of the projectile suggest that all these Be isotopes show significant suppression of complete fusion, a surprising result given that the α-breakup threshold energies are 1.57 MeV for 9 Be but over 7 MeV for 10,11 Be. Further experimental studies to investigate in more detail the division between complete and incomplete fusion for reactions of 10,11 Be are needed.

  19. Indirect drive targets for fusion power

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, Peter A.; Miles, Robin R.

    2016-10-11

    A hohlraum for an inertial confinement fusion power plant is disclosed. The hohlraum includes a generally cylindrical exterior surface, and an interior rugby ball-shaped surface. Windows over laser entrance holes at each end of the hohlraum enclose inert gas. Infrared reflectors on opposite sides of the central point reflect fusion chamber heat away from the capsule. P2 shields disposed on the infrared reflectors help assure an enhanced and more uniform x-ray bath for the fusion fuel capsule.

  20. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    International Nuclear Information System (INIS)

    Barboza, N.O.

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of ∼17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, ∼200 g/cm 3 and ∼20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases ∼350 MJ of energy in optimized power plant scenarios

  1. Synthesis of superheavy elements by cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S [Gesellschaft fuer Schwerionenforschung (GSI), Helmholtzzentrum fuer Schwerionenforschung Gmbh (Germany)

    2009-12-31

    The nuclear shell model predicts that the next doubly magic shell-closure beyond {sup 208}Pb is at the proton number Z=114, 120, or 126 and at the neutron number N=172 or 184. The outstanding aim of experimental investigations is the exploration of this region of spherical 'Super Heavy Elements' (SHEs). Using cold fusion reactions which are based on lead and bismuth targets, the new elements from 107 to 112 were synthesized at GSI in Darmstadt, Germany. Some of these results were confirmed at RIKEN in Wako, Japan, where also a relatively neutron-deficient isotope of element 113 was synthesized. In hot fusion reactions of {sup 48}Ca projectiles with actinide targets, a more neutron-rich isotope of element 112 and the new elements from 113 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these hot fusion data, which represent the first identification of nuclei located on the predicted island of SHEs, were confirmed in two independent experiments. The decay data reveal that for the heaviest elements, the dominant decay mode is alpha emission rather than fission. The decay properties as well as reaction cross-sections are compared with results of theoretical studies.

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

    Science.gov (United States)

    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.

  3. Experimental Determination of the Possible Deuterium - Deuterium Fusion Reaction Originated in a Single Cavitation Bubble Luminescence System Using CDCL3 and D2 O

    International Nuclear Information System (INIS)

    Barbaglia, Mario; Florido, Pablo; Mayer, Roberto; Bonetto, Fabian

    2003-01-01

    We focus this work on the measurement of the possible Deuterium - Deuterium reaction in a SCBL (Single Cavitation Bubble Luminescence) system.We measure the possible reaction at the bubble generation time and at the bubble collapse time. We use a Nd:YAG laser and CDCl 3 and D 2 O as a medium to generate the bubble. Since CDCl 3 accommodation coefficient is best than that of D 2 O, it is expected a greater collapse force than using D 2 O.To benefit the bubble collapse violence, we diminish the temperature of the liquids.To avoid false neutron detection, we developed a measuring system with high background reject using the characteristic experiment times.No neutrons attributable to Deuterium - Deuterium fusion reaction were measured

  4. The present role of superconductivity in fusion

    International Nuclear Information System (INIS)

    Shimamoto, S.

    1986-01-01

    After completion of large fusion devices in the world, such as JT-60, JET and TFTR, high temperature plasma is proceeding to critical condition for fusion. The devices up to now use mainly conventional magnet. However, for the next generation machine which demonstrates fusion reaction, deuterium-tritium burning, superconducting magnet system is indispensable from view point of both net energy extraction and capacity limitation of power supply. In order to realize such a large and complicated system, a lot of development works is being carried out. This paper describes required parameters of superconducting magnet and helium refrigerator, the state of plasma condition and superconducting magnet. It is shown that the present technology of superconducting magnet is not so far from realization of fusion experimental reactor

  5. Development of target capsules for muon catalyzed fusion experiments

    International Nuclear Information System (INIS)

    Watts, K.D.; Jones, S.E.; Caffrey, A.J.

    1983-01-01

    A series of Muon Catalyzed Fusion experiments has been conducted at the Los Alamos Meson Physics Facility to determine how many fusion reactions one muon would catalyze under various temperature, pressure, contamination, and tritium concentration conditions. Target capsules to contain deuterium and tritium at elevated temperatures and pressures were engineered for a maximum temperature of 540 K (512 0 F) and a maximum pressure of 103 MPa (15,000 psig). Experimental data collected with these capsules indicated that the number of fusion reactions per muon continued to increase with temperature up to the 540-K design limit. Theory had indicated that the reaction rate should peak at approximately 540 K, but this was not confirmed during the experiments. A second generation of capsules which have a maximum design temperature of 800 K (980 0 F) and a maximum design pressure of 103 MPa (15,000 psig) has now been engineered. These new capsules will be used to further study the muon catalysis rate versus deuterium-tritium mixture temperature

  6. Structure information from fusion barriers

    Indian Academy of Sciences (India)

    Pb, using the coupled reaction channel (CRC) method and correct structure information, have been analysed. The barrier distributions derived from these excitation functions including many of the significant channels are featureless, although these channels have considerable effects on the fusion excitation function.

  7. Cold fusion and hot history

    International Nuclear Information System (INIS)

    Lewenstein, B.

    1996-01-01

    The history of cold fusion research following the announcement of the Pons-Fleischmann experiment is described in detail, including all the confusion, responses of scientists, personal impressions, personal quotations, reactions of the media, references to contemporary sources, etc. (P.A.). 5 figs

  8. The conserved glycine residues in the transmembrane domain of the Semliki Forest virus fusion protein are not required for assembly and fusion

    International Nuclear Information System (INIS)

    Liao Maofu; Kielian, Margaret

    2005-01-01

    The alphavirus Semliki Forest virus (SFV) infects cells via a low pH-triggered fusion reaction mediated by the viral E1 protein. Both the E1 fusion peptide and transmembrane (TM) domain are essential for membrane fusion, but the functional requirements for the TM domain are poorly understood. Here we explored the role of the five TM domain glycine residues, including the highly conserved glycine pair at E1 residues 415/416. SFV mutants with alanine substitutions for individual or all five glycine residues (5G/A) showed growth kinetics and fusion pH dependence similar to those of wild-type SFV. Mutants with increasing substitution of glycine residues showed an increasingly more stringent requirement for cholesterol during fusion. The 5G/A mutant showed decreased fusion kinetics and extent in fluorescent lipid mixing assays. TM domain glycine residues thus are not required for efficient SFV fusion or assembly but can cause subtle effects on the properties of membrane fusion

  9. Progress of laser fusion research

    International Nuclear Information System (INIS)

    Yamanaka, Chiyoe

    1988-01-01

    The history of the research on nuclear fusion utilizing laser is described. It started in USSR in 1968, but the full scale start of laser implosion nuclear fusion was in 1972. In Osaka University, nuclear fusion neutrons were detected with a solid deuterium target and the phenomenon of parametric abnormal absorption in laser plasma was found in 1971. The new type target for implosion nuclear fusion ''Canon ball'' was devised in 1975. The phenomenon of the abnormal transmission of laser beam through a thin metal film in a multiple film target was found in 1976, and named ''Osaka effect''. Also the development of lasers has been advanced, and in 1983, a largest glass laser in the world, Gekko 12, with 12 beams, 30 kJ output, 55 TW, was completed. The new target LHART was devised, which enabled the generation of 10 trillion D-T reaction neutrons. Due to the development of high power laser technology, the realization of the new design of fuel pellets, the evaluation of the data by computer simulation, and the realization of new plasma diagnostic method, the research on laser nuclear fusion has developed rapidly, and the attainment of break-even is expected in 1990s. The features of inertial nuclear fusion are enumerated. (Kako, I.)

  10. Cold fusion in perspective

    International Nuclear Information System (INIS)

    Sanford, L.

    1989-01-01

    Since early April a great deal of excitement has been created over the Fleischmann/Pons cold fusion experiment, which if it performs as advertised, could turn out to be mankind's best hope of heading off the energy crisis scheduled for early in the next century. Dozens of groups around the world are now attempting to duplicate the experiment to see if Fleischmann and Pons' discovery is an experimental mistake, an unknown electrochemical effect or a new kind of fusion reaction. This article puts the experiment into the perspective of today and looks at how it might affect the energy scene tomorrow if it should turn out to be commercially exploitable. (author)

  11. Site-directed antibody immobilization using a protein A-gold binding domain fusion protein for enhanced SPR immunosensing.

    Science.gov (United States)

    de Juan-Franco, Elena; Caruz, Antonio; Pedrajas, J R; Lechuga, Laura M

    2013-04-07

    We have implemented a novel strategy for the oriented immobilization of antibodies onto a gold surface based on the use of a fusion protein, the protein A-gold binding domain (PAG). PAG consists of a gold binding peptide (GBP) coupled to the immunoglobulin-binding domains of staphylococcal protein A. This fusion protein provides an easy and fast oriented immobilization of antibodies preserving its native structure, while leaving the antigen binding sites (Fab) freely exposed. Using this immobilization strategy, we have demonstrated the performance of the immunosensing of the human Growth Hormone by SPR. A limit of detection of 90 ng mL(-1) was obtained with an inter-chip variability lower than 7%. The comparison of this method with other strategies for the direct immobilization of antibodies over gold surfaces has showed the enhanced sensitivity provided by the PAG approach.

  12. Binding of cholesterol and inhibitory peptide derivatives with the fusogenic hydrophobic sequence of F-glycoprotein of HVJ (Sendai virus): possible implication in the fusion reaction

    International Nuclear Information System (INIS)

    Asano, K.; Asano, A.

    1988-01-01

    Specificity of the binding of sterols and related compounds with purified F-protein (fusion protein) of the HVJ (Sendai virus) was studied by binding competition with [ 3 H] cholesterol. Requirement for cholesterol or the A/B ring trans structure and nonrequirement for the 3-hydroxyl group were found in this binding. Binding of 125 I-labeled Z-Phe-Tyr, an inhibitory peptide of viral membrane-cell membrane fusion, was studied by using purified proteins and virions. F-Protein and virions showed a specific binding with the peptide, whereas the result was negative with hemagglutinin and neuraminidase protein. Thermolysin-truncated F-protein (an F-protein derivative deprived of a 2.5-kDa fragment from the N-terminal of the F 1 subunit and without fusogenic activity) exhibited a considerably diminished binding ability both to cholesterol and to inhibitory peptides. Therefore, the N-terminal hydrophobic sequence that was previously assigned as fusogenic seems to be the binding site of these molecules. In support of this, the binding of cholesterol with F-protein was inhibited by Z-Phe-Tyr and other fusion inhibitory peptides, whereas it was not affected with non-fusion-inhibitory Z-Gly-Phe. These results are discussed in relation to the notion that the binding of the N-terminal portion of the F 1 subunit of F-protein with cholesterol in the target cell membranes facilitiates the fusion reaction

  13. Maltose-binding protein enhances secretion of recombinant human granzyme B accompanied by in vivo processing of a precursor MBP fusion protein.

    Directory of Open Access Journals (Sweden)

    Benjamin Dälken

    Full Text Available BACKGROUND: The apoptosis-inducing serine protease granzyme B (GrB is an important factor contributing to lysis of target cells by cytotoxic lymphocytes. Expression of enzymatically active GrB in recombinant form is a prerequisite for functional analysis and application of GrB for therapeutic purposes. METHODS AND FINDINGS: We investigated the influence of bacterial maltose-binding protein (MBP fused to GrB via a synthetic furin recognition motif on the expression of the MBP fusion protein also containing an N-terminal α-factor signal peptide in the yeast Pichia pastoris. MBP markedly enhanced the amount of GrB secreted into culture supernatant, which was not the case when GrB was fused to GST. MBP-GrB fusion protein was cleaved during secretion by an endogenous furin-like proteolytic activity in vivo, liberating enzymatically active GrB without the need of subsequent in vitro processing. Similar results were obtained upon expression of a recombinant fragment of the ErbB2/HER2 receptor protein or GST as MBP fusions. CONCLUSIONS: Our results demonstrate that combination of MBP as a solubility enhancer with specific in vivo cleavage augments secretion of processed and functionally active proteins from yeast. This strategy may be generally applicable to improve folding and increase yields of recombinant proteins.

  14. Maltose-Binding Protein Enhances Secretion of Recombinant Human Granzyme B Accompanied by In Vivo Processing of a Precursor MBP Fusion Protein

    Science.gov (United States)

    Dälken, Benjamin; Jabulowsky, Robert A.; Oberoi, Pranav; Benhar, Itai; Wels, Winfried S.

    2010-01-01

    Background The apoptosis-inducing serine protease granzyme B (GrB) is an important factor contributing to lysis of target cells by cytotoxic lymphocytes. Expression of enzymatically active GrB in recombinant form is a prerequisite for functional analysis and application of GrB for therapeutic purposes. Methods and Findings We investigated the influence of bacterial maltose-binding protein (MBP) fused to GrB via a synthetic furin recognition motif on the expression of the MBP fusion protein also containing an N-terminal α-factor signal peptide in the yeast Pichia pastoris. MBP markedly enhanced the amount of GrB secreted into culture supernatant, which was not the case when GrB was fused to GST. MBP-GrB fusion protein was cleaved during secretion by an endogenous furin-like proteolytic activity in vivo, liberating enzymatically active GrB without the need of subsequent in vitro processing. Similar results were obtained upon expression of a recombinant fragment of the ErbB2/HER2 receptor protein or GST as MBP fusions. Conclusions Our results demonstrate that combination of MBP as a solubility enhancer with specific in vivo cleavage augments secretion of processed and functionally active proteins from yeast. This strategy may be generally applicable to improve folding and increase yields of recombinant proteins. PMID:21203542

  15. Fusion Plasma Physics and ITER - An Introduction (2/4)

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    The second lecture will explore some of the key physics phenomena which govern the behaviour of magnetic fusion plasmas and which have been the subject of intense research during the past 50 years: plasma confinement, magnetohydrodynamic stability and plasma-wall interactions encompass the major areas of plasma physics which must be understood to assemble an overall description of fusion plasma behaviour. In addition, as fusion plasmas approach the “burning plasma” regime, where internal heating due to fusion products dominates other forms of heating, the physics of the interaction between the α-particles produced by D-T fusion reactions and the thermal “background” plasma becomes significant. This lecture will also introduce the basic physics of fusion plasma production, plasma heating and current drive, and plasma measurements (“diagnostics”).

  16. Fusion safety program Annual report, Fiscal year 1995

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Cadwallader, L.C.; Carmack, W.J.

    1995-12-01

    This report summarizes the major activities of the Fusion Safety Program in FY-95. The Idaho National Engineering Laboratory (INEL) is the designated lead laboratory, and Lockheed Idaho Technologies Company is the prime contractor for this program. The Fusion Safety Program was initiated in 1979. Activities are conducted at the INEL, at other DOE laboratories, and at other institutions. Among the technical areas covered in this report are tritium safety, beryllium safety, chemical reactions and activation product release, safety aspects of fusion magnet systems, plasma disruptions, risk assessment failure rate database development, and safety code development and application to fusion safety issues. Most of this work has been done in support of the International Thermonuclear Experimental Reactor (ITER). Also included in the report are summaries of the safety and environmental studies performed by the Fusion Safety Program for the Tokamak Physics Experiment and the Tokamak Fusion Test Reactor and the technical support for commercial fusion facility conceptual design studies. A final activity described is work to develop DOE Technical Standards for Safety of Fusion Test Facilities

  17. Electrodeless, multi-megawatt reactor for room-temperature, lithium-6/deuterium nuclear reactions

    International Nuclear Information System (INIS)

    Drexler, J.

    1993-01-01

    This paper describes a reactor design to facilitate a room-temperature nuclear fusion/fission reaction to generate heat without generating unwanted neutrons, gamma rays, tritium, or other radioactive products. The room-temperature fusion/fission reaction involves the sequential triggering of billions of single-molecule, 6 LiD 'fusion energy pellets' distributed in lattices of a palladium ion accumulator that also acts as a catalyst to produce the molecules of 6 LiD from a solution comprising D 2 O, 6 LiOD with D 2 gas bubbling through it. The D 2 gas is the source of the negative deuterium ions in the 6 LiD molecules. The next step is to trigger a first nuclear fusion/fission reaction of some of the 6 LiD molecules, according to the well-known nuclear reaction: 6 Li + D → 2 4 He + 22.4 MeV. The highly energetic alpha particles ( 4 He nuclei) generated by this nuclear reaction within the palladium will cause shock and vibrations in the palladium lattices, leading to compression of other 6 LiD molecules and thereby triggering a second series of similar fusion/fission reactions, leading to a third series, and so on. The absorption of the kinetic energy in the palladium will, in turn, generate a continuous flow of heat into the heavy water carrier, which would be removed with a heat exchanger. (author)

  18. Nuclear Fusion Fuel Cycle Research Perspectives

    International Nuclear Information System (INIS)

    Chung, Hongsuk; Koo, Daeseo; Park, Jongcheol; Kim, Yeanjin; Yun, Sei-Hun

    2015-01-01

    As a part of the International Thermonuclear Experimental Reactor (ITER) Project, we at the Korea Atomic Energy Research Institute (KAERI) and our National Fusion Research Institute (NFRI) colleagues are investigating nuclear fusion fuel cycle hardware including a nuclear fusion fuel Storage and Delivery System (SDS). To have a better knowledge of the nuclear fusion fuel cycle, we present our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). To have better knowledge of the nuclear fusion fuel cycle, we presented our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). Our efforts to enhance the tritium confinement will be continued for the development of cleaner nuclear fusion power plants

  19. Electron screening in molecular fusion reactions

    International Nuclear Information System (INIS)

    Shoppa, T.D.

    1996-01-01

    Recent laboratory experiments have measured fusion cross sections at center-of-mass energies low enough for the effects of atomic and molecular electrons to be important. To extract the cross section for bare nuclei from these data (as required for astrophysical applications), it is necessary to understand these screening effects. We study electron screening effects in the low-energy collisions of Z=1 nuclei with hydrogen molecules. Our model is based on a dynamical evolution of the electron wave functions within the TDHF scheme, while the motion of the nuclei is treated classically. We find that at the currently accessible energies the screening effects depend strongly on the molecular orientation. The screening is found to be larger for molecular targets than for atomic targets, due to the reflection symmetry in the latter. The results agree fairly well with data measured for deuteron collisions on molecular deuterium and tritium targets. (orig.)

  20. Thermodynamic and molecular origin of interfacial rate enhancements and endo-selectivities of a Diels-Alder reaction.

    Science.gov (United States)

    Beniwal, Vijay; Kumar, Anil

    2017-02-08

    Organic reactions in general display large rate accelerations when performed under interfacial conditions, such as on water or at ionic liquid interfaces. However, a clear picture of the physicochemical factors responsible for this large rate enhancements is not available. To gain an understanding of the thermodynamic and molecular origin of these large rate enhancements, we performed a Diels-Alder reaction between cyclopentadiene and methyl acrylate at ionic liquid/n-hexane interfaces. This study describes, for the first time, a methodology for the calculation of the activation parameters of an interfacial reaction. It has been seen that the energy of activation for an interfacial reaction is much smaller than that of the corresponding homogeneous reaction, resulting into the large rate acceleration for the interfacial reaction. Furthermore, the study describes the effects of the alkyl chain length of ionic liquid cations, the extent of heterogeneity, and the polarity of ionic liquids on the rate constants and stereoselectivity of the reaction.

  1. TPE upgrade for enhancing operational safety and improving in-vessel tritium inventory assessment in fusion nuclear environment

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, M., E-mail: Masashi.Shimada@inl.gov [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Taylor, C.N.; Moore-McAteer, L.; Pawelko, R.J. [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Kolasinski, R.D.; Buchenauer, D.A. [Sandia National Laboratories, Hydrogen and Materials Science Department, Livermore, CA 94550 (United States); Cadwallader, L.C.; Merrill, B.J. [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2016-11-01

    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 evaluate in-vessel tritium inventory in the nuclear environment for fusion safety. The electrical upgrade were recently carried out to enhance operational safety and to improve plasma performance. 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 and eliminating heat stress issue. In November 2015, the TPE successfully achieved first deuterium plasma via remote operation after a significant three-year upgrade. Simple linear scaling estimate showed that the TPE is expected to achieve Γ{sub i}{sup max} of >1.0 × 10{sup 23} m{sup −2} s{sup −1} and q{sub heat} of >1 MW m{sup −2} with new power supplies. 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, FNSF, and DEMO for improving in-vessel tritium inventory assessment in fusion nuclear environment.

  2. Inertial fusion and energy production

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1982-01-01

    Inertial-confinement fusion (ICF) is a technology for releasing nuclear energy from the fusion of light nuclei. For energy production, the most reactive hydrogen isotopes (deuterium (D) and tritium (T)) are commonly considered. The energy aplication requires the compression of a few milligrams of a DT mixture to great density, approximately 1000 times its liquid-state density, and to a high temperature, nearly 100 million 0 K. Under these conditions, efficient nuclear-fusion reactions occur, which can result in over 30% burn-up of the fusion fuel. The high density and temperature can be achieved by focusing very powerful laser or ion beams onto the target. The resultant ablation of the outer layers of the target compresses the fuel in the target, DT ignition occurs, and burn-up of the fuel results as the thermonuclear burn wave propagates outward. The DT-fuel burn-up occurs in about 199 picoseconds. On this short time scale, inertial forces are sufficiently strong to prevent target disassembly before fuel burn-up occurs. The energy released by the DT fusion is projected to be several hundred times greater than the energy delivered by the driver. The present statuds of ICF technology is described

  3. Thinking about the cold fusion fever

    International Nuclear Information System (INIS)

    Kitsunezaki, Akio

    1989-01-01

    The excitement since March 23 on cold fusion seems to be unprecedented evidence that the people of the world are waiting for fusion power with much enthusiasm. Cold fusion is really a surprise because it does not need high temperature and because it seems to be easy to enlarge the test tube into a useful power source if the claim by Professors Pons and Fleischmann at the University of Utah are true. The second announcement of cold fusion came from the Brigham Young University, also in the state of Utah, by Professor Jones, but his report was totally different from that given by Pons and Fleischmann. From the beginning of the 'fever', physicists have been very skeptical about cold fusion. Most of the critics and criticisms are targeted on Pons and Fleischmann rather than Jones, because not only was their paper poor but also their statements have not been scientific. They insisted that the heat came from fusion reaction, but without any scientific proof. They had not carried out the basic control experiment by running the same test with ordinary water instead of heavy water. A meeting on cold fusion was held at JAERI on May 15. At the end of the meeting, the some 260 attendants knew that cold fusion was not conceivable with the current scientific knowledge. (N.K.)

  4. Some safety considerations of liquid lithium as a fusion breeder material

    International Nuclear Information System (INIS)

    Jeppson, D.W.; Muhlestein, L.D.

    1986-01-01

    Test results and conclusions are presented for the reaction of steam with a high temperature lithium pool and for the reaction of high temperature lithium spray with a nitrogen atmosphere. The reactions are characterized and evaluated in regard to the potential for mobilization of radioactive species associated with the liquid breeder under postulated fusion reactor accident conditions. These evaluations include measured lithium temperature responses, atmosphere temperature and pressure responses, gas consumption and generation, aerosol quantities and particle size characterization, and potentially radioactive species releases. Conclusions are made as to the consequences of these safety considerations for the use of lithium as a fusion reactor breeder material

  5. Barrier for cold-fusion production of superheavy elements

    International Nuclear Information System (INIS)

    Ichikawa, Takatoshi; Iwamoto, Akira; Moeller, Peter; Sierk, Arnold J.

    2005-01-01

    We estimate the fusion-barrier height B fu (two-body) for approaching ions in cold-fusion reactions in a model where the projectile deformation and quadrupole zero-point vibrational energy are taken into account. This barrier height is defined as the barrier energy at the target and projectile separation distance where an original oblate deformation of projectile and/or target caused by a repulsive Coulomb force turns into a large prolate deformation caused by the attractive nuclear force as the target and projectile come closer. The instability develops before touching because the attractive short-range nuclear force overcomes the repulsive Coulomb force and the shape-stabilizing effect of shell structure. The shell structure of the doubly magic 208 Pb target is sufficiently strong that its shape remains very close to spherical in all cases studied here. The fusion potential for approaching ions in the two-body channel is calculated in the macroscopic-microscopic model with the quadrupole vibrational zero-point energy obtained in the WKB approximation. We compare our results with data from 10 experimental cold-fusion reactions and with the Bass barriers. Differences and similarities between the Yukawa-plus-exponential model and the Bass model are discussed. We also calculate five-dimensional potential-energy surfaces for the single compound system and show that well-established fission and fusion valleys are both present. For heavy systems, B fu (two-body) becomes lower than the fission barrier just beyond the ground state of the compound system. In the vicinity of this transition, the optimum collision energy for formation of evaporation residues can be expected to depend in a delicate fashion on the interplay among B fu (two-body) , the fusion valley, the fission barrier of the compound system, and the one- and two-neutron separation energies S 1n and S 2n . We discuss these issues in detail and calculate fission-barrier heights. Except for reactions in which

  6. Exploring dissipative processes at high angular momentum in 58Ni+60Ni reactions

    Directory of Open Access Journals (Sweden)

    Williams E.

    2016-01-01

    Full Text Available Current coupled channels (CC models treat fusion as a coherent quantum-mechanical process, in which coupling between the collective states of the colliding nuclei influences the probability of fusion in near-barrier reactions. While CC models have been used to successfully describe many experimental fusion barrier distribution (BD measurements, the CC approach has failed in the notable case of 16O+208Pb. The reason for this is poorly understood; however, it has been postulated that dissipative processes may play a role. Traditional BD experiments can only probe the physics of fusion for collisions at the top of the Coulomb barrier (L = 0ħ. In this work, we will present results using a novel method of probing dissipative processes inside the Coulomb barrier. The method exploits the predicted sharp onset of fission at L ~ 60ħ for reactions forming compound nuclei with A < 160. Using the ANU’s 14UD tandem accelerator and CUBE spectrometer, reaction outcomes have been measured for the 58Ni+60Ni reaction at a range of energies, in order to explore dissipative processes at high angular momentum. In this reaction, deep inelastic processes have been found to set in before the onset fission at high angular momentum following fusion. The results will be discussed in relation to the need for a dynamical model of fusion.

  7. Probing of complete and incomplete fusion dynamics in heavy-ion ...

    Indian Academy of Sciences (India)

    2014-04-04

    Apr 4, 2014 ... Heavy-ion induced reactions; complete and incomplete fusion; ... CF reaction the projectile completely fuses with the target nucleus and the highly excited .... input parameters have been used as default except the charge and ...

  8. Liquid metal technology in fusion

    International Nuclear Information System (INIS)

    Torre Cabezas, M. de la; Martin Espigares, M.; Lapena, J.

    1985-01-01

    Lithium (or Li-Pb) is one of the several possible coolants being considered for the blanket of magnetic toroidal fusion reactor, not only because of its good thermal and neutron properties, but also because the tritium required to fuel the reactor can be produced by neutron reactions in the lithium. In this paper two main technology tasks to be proposed in our fusion programme have been identified: 1) the development of impurity monitoring devices for use in lithium and Li-Pb environments; 2) effects of Li and Li-Pb environments on the low cycle fatigue properties of different steels. (author)

  9. Nuclear fusion in a solid body

    International Nuclear Information System (INIS)

    Romodanov, V.A.; Savin, V.I.; Shakhurin, M.V.; Chernyavskij, V.T.; Pustovit, A.E.

    1991-01-01

    The present work was aimed at investigating a possibility to have a fusion reaction during the interaction of gaseous deuterium with various metals under conditions of glow discharge. It is shown that neutron flux which presumably occurs due to the reaction of nuclear fusion exceeded the background level two times maximum for such materials as Cr, Pd, B, Li. A conclusion is made that for the recording of neutrons which can be generated under bombardment of material surfaces with accelerated ions an additional shielding of standard recorders is required against electromagnetic oscillations both in the input circuits and power supply circuits. A significant increase of tritium concentration in deuterium was recorded (by mass spectrometry and β activity measurement) during the passage of the latter through the metal being bombarded with accelerated ions from glow discharge plasma

  10. Accelerators for Fusion Materials Testing

    Science.gov (United States)

    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

  11. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  12. Characterization of the functional requirements of West Nile virus membrane fusion.

    Science.gov (United States)

    Moesker, Bastiaan; Rodenhuis-Zybert, Izabela A; Meijerhof, Tjarko; Wilschut, Jan; Smit, Jolanda M

    2010-02-01

    Flaviviruses infect their host cells by a membrane fusion reaction. In this study, we performed a functional analysis of the membrane fusion properties of West Nile virus (WNV) with liposomal target membranes. Membrane fusion was monitored continuously using a lipid mixing assay involving the fluorophore, pyrene. Fusion of WNV with liposomes occurred on the timescale of seconds and was strictly dependent on mildly acidic pH. Optimal fusion kinetics were observed at pH 6.3, the threshold for fusion being pH 6.9. Preincubation of the virus alone at pH 6.3 resulted in a rapid loss of fusion capacity. WNV fusion activity is strongly promoted by the presence of cholesterol in the target membrane. Furthermore, we provide direct evidence that cleavage of prM to M is a requirement for fusion activity of WNV.

  13. Structural materials for fusion and spallation sources

    International Nuclear Information System (INIS)

    Cottrell, G.A.; Baker, L.J.

    2003-01-01

    Experimental investigation of neutron-induced irradiation damage in structural materials is fundamental to the development of magnetic confinement fusion. Proposals for the testing of candidate materials are described, indicating that a period of at least 10 years will elapse before a suitable high neutron fluence fusion test facility becomes available. In this circumstance, the possibility that neutron spallation sources could be exploited to shorten the time-scale of fusion materials development is attractive. Although fusion displacement and transmutation reaction rates can be replicated in spallation sources, there are significant differences arising from the harder neutron spectra and the presence of energetic protons. These differences, including higher energy PKA, electron heating effects, transmutation rates and pulsing are described and their consequences discussed, together with the concomitant development of theoretical models, needed to understand the effects. It is concluded that spallation source experiments could make a significant contribution to the database required for the validation of theoretical models, and hence reduce the time scale of fusion materials development

  14. TMX: a new fusion plasma experiment

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The primary goal of the magnetic fusion energy program at LLL is the development of a technically and economically feasible approach to the generation of fusion energy. Results from our earlier 2XIIB experiment lead us to believe that a fusion power plant based on a mirror system is technically feasible, assuming a favorable extrapolation to plasmas of reactor size. Achieving economic feasibility is more difficult. For power-producing applications, a reactor needs a large Q, the ratio of fusion power output to the power injected to sustain the system. In a conventional mirror reactor, the fusion power is only about equal to the power injected by the neutral beams--that is, Q is only about unity. A new idea, the tandem mirror concept described in this article, promises to increase this gain, enhancing Q by at least a factor of 5

  15. Clinical experience of adverse drug reaction in gadolinium-DTPA enhancement of MRI

    International Nuclear Information System (INIS)

    Kim, Mi Hyae; Hong, Ju Hee; Lee, Yeon Su; Cha, Kyung Soo; Chang, Suk Il; Lee, Young Chul; Kim, Yeong Soo

    1992-01-01

    Gadopentetate dimenglumine(Gd-DTPA) has low toxicity and good tolerance and it is said that the observed adverse drug reaction of Gd-DTPA is compatible to those of iodinated nonionic contrast media. The overall incidence of adverse drug reaction of Gd-DTPA is even lower than those of iodinated nonionic contrast media. Then, the possibility of potential adverse drug reaction of these contrast media is not fully known and recently, many authors have a growing interest in this point. We have taken 2501 cases of MRI and executed 1467 case of Gd-DTPA enhancement scanning(58.7%) and experienced 12 cases of adverse drug reaction(11 cases: mild reaction, 1 case: severs anaphylactic shock) and the overall incidence of our adverse drug reaction of Gd-DTPA was 0.8%. In conclusion, the adverse drug reaction of Gd-DTPA is not rare and the severe adverse drug reaction of Gd-DTPA may occur. So, the possibility of adverse drug reaction after Gd-DTPA injection should always be kept in mind, especially when the patient has a history of reaction to contrast material, allergy(particularly asthma) and cardiac disease. For the safe use of Gd-DTPA, well trained personnel and nearby emergent care facilities should be available

  16. Fusion Nuclear Data activities at FNL, IPR

    OpenAIRE

    P. M. Prajapati; B. Pandey; S. Jakhar; C.V. S. Rao; T. K. Basu; B. K. Nayak; S. V. Suryanarayana; A. Saxena

    2015-01-01

    This paper briefly describes the current fusion nuclear data activities at Fusion Neutronics Laboratory, Institute for Plasma Research. It consist of infrastructure development for the cross-section measurements of structural materials with an accelerator based 14 MeV neutron generator and theoretical study of the cross-section using advanced nuclear reaction modular codes EMPIRE and TALYS. It will also cover the proposed surrogate experiment to measure 55Fe (n, p) 55Mn using BARC-TIFR Pel...

  17. The many languages of subbarrier heavy ion fusion

    International Nuclear Information System (INIS)

    Wolter, H.H.

    1991-01-01

    The different pictures to describe subbarrier fusion are reviewed and related to each other. The direct reaction approach to fusion is developed in a Feshbach picture of open and closed channels and the role of absorptive potentials is discussed. This mono-nuclear picture which treats the degrees of freedom of one nucleus is seen versus a di-nuclear picture where the degrees of freedom of the fusing system are directly treated. Here we have performed a study of multidimensional tunneling which shows the importance of neck formation. We also discuss the problem of dissipation in subbarrier fusion. (author)

  18. Enhancing the efficiency of polymerase chain reaction using graphene nanoflakes.

    Science.gov (United States)

    Abdul Khaliq, R; Kafafy, Raed; Salleh, Hamzah Mohd; Faris, Waleed Fekry

    2012-11-16

    The effect of the recently developed graphene nanoflakes (GNFs) on the polymerase chain reaction (PCR) has been investigated in this paper. The rationale behind the use of GNFs is their unique physical and thermal properties. Experiments show that GNFs can enhance the thermal conductivity of base fluids and results also revealed that GNFs are a potential enhancer of PCR efficiency; moreover, the PCR enhancements are strongly dependent on GNF concentration. It was found that GNFs yield DNA product equivalent to positive control with up to 65% reduction in the PCR cycles. It was also observed that the PCR yield is dependent on the GNF size, wherein the surface area increases and augments thermal conductivity. Computational fluid dynamics (CFD) simulations were performed to analyze the heat transfer through the PCR tube model in the presence and absence of GNFs. The results suggest that the superior thermal conductivity effect of GNFs may be the main cause of the PCR enhancement.

  19. Theoretical study of cross sections of proton-induced reactions on cobalt

    Directory of Open Access Journals (Sweden)

    Mustafa Yiğit

    2018-04-01

    Full Text Available Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on 59Co structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code. Keywords: Cobalt, Nuclear Structural Materials, Reaction Cross Section, TENDL Database

  20. The fusion of heavy ions in an interaction potential model

    International Nuclear Information System (INIS)

    Zipper, W.

    1980-01-01

    The paper contains the problems connected with fusion processes in heavy ions collision. Results of experimental fusion data for reactions: 9 Be + 12 C, 6 Li + 28 Si, 9 Be + 28 Si, 12 C + 28 Si, 12 C + 16 O and 16 O + 16 O are presented. Comparison of measured fusion cross sections with predictions of the fusion potential model have been made. The validity of this model for both light systems, like 9 Be + 12 C and heavy systems, like 35 Cl + 62 Ni, have been discussed. In conclusion, it should be stated that fusion cross sections could be correctly predicted by the potential model with a potential describing the elastic scattering data. (author)