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Sample records for complete fusion quasifission

  1. Competition between complete fusion and quasifission in reactions with heavy nuclei

    SciTech Connect

    Antonenko, N. V.; Scheid, W.; Adamian, G. G.; Volkov, V. V.

    1998-02-15

    A model based on the dinuclear system concept is suggested for the calculation of the competition between complete fusion and quasifission in reactions with heavy nuclei. The fusion rate through the inner fusion barrier in mass asymmetry is found by using the Kramers-type expression. The calculated cross sections for the heaviest nuclei are in a good agreement with the experimental data. The experimentally observed rapid fall-off of the cross section of the cold fusion with increasing charge number Z of the compound nucleus is explained.

  2. Fusion, fission, and quasi-fission using TDHF

    NASA Astrophysics Data System (ADS)

    Umar, Sait; Oberacker, Volker

    2014-03-01

    We study fusion, fission, and quasi-fission reactions using the time-dependent Hartee-Fock (TDHF) approach together with the density-constrained TDHF method for fusion. The only input is the Skyrme NN interaction, there are no adjustable parameters. We discuss the identification of quasi-fission in 40Ca+238U, the scission dynamics in symmetric fission of 264Fm, as well as calculating heavy-ion interaction potentials V (R) , mass parameters M (R) , and total fusion cross sections from light to heavy systems. Some of the effects naturally included in these calculations are: neck formation, mass exchange, internal excitations, deformation effects, as well as nuclear alignment for deformed systems. Supported by DOE grant DE-FG02-96ER40975.

  3. Analysis of quasifission competition in fusion reactions forming heavy nuclei

    NASA Astrophysics Data System (ADS)

    Hammerton, Kalee; Kohley, Zachary; Morrissey, Dave; Wakhle, Aditya; Stiefel, Krystin; Hinde, David; Dasgupta, Mahananda; Williams, Elizabeth; Simenel, Cedric; Carter, Ian; Cook, Kaitlin; Jeung, Dongyun; Luong, Duc Huy; McNeil, Steven; Palshetkar, Chandani; Rafferty, Dominic

    2015-10-01

    Heavy-ion fusion reactions have provided a mechanism for the production of superheavy elements allowing for the extension of both the periodic table and chart of the nuclides. However, fusion of the projectile and target, forming a compound nucleus, is hindered by orders of magnitude by the quasifission process in heavy systems. In order to fully understand this mechanism, and make accurate predictions for superheavy element production cross sections, a clear description of the interplay between the fusion-fission and quasifission reaction channels is necessary. The mass-angle distributions of fragments formed in 8 different Cr + W reactions were measured at the Australia National University in order to explore the N/Z dependence of the quasifission process. Two sets of data were measured: one at a constant energy relative to the fusion barrier and one at a constant compound nucleus excitation energy. The results of this analysis will provide insight into the effect of using more neutron-rich beams in superheavy element production reactions.

  4. Quasifission dynamics in TDHF

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Simenel, C.

    2016-05-01

    For light and medium mass systems the capture cross-section may be considered to be the same as that for complete fusion, whereas for heavy systems leading to superheavy formations the evaporation residue cross-section is dramatically reduced due to the quasifission (QF) and fusion-fission processes thus making the capture cross-section to be essentially the sum of these two cross-sections, with QF occurring at a much shorter time-scale. Consequently, quasifission is the primary reaction mechanism that limits the formation of superheavy nuclei. Within the last few years the time-dependent Hartree-Fock (TDHF) approach has been utilized for studying the dynamics of quasifission. The study of quasifission is showing a great promise to provide insight based on very favorable comparisons with experimental data. In this article we will focus on the TDHF calculations of quasifission observables for the 48Ca+249Bk system.

  5. Description of quasifission reactions in the dinuclear system model

    NASA Astrophysics Data System (ADS)

    Adamian, G. G.; Antonenko, N. V.; Kalandarov, Sh. A.

    2016-01-01

    The formation and evolution of dinuclear systems in quasifission reactions are investigated. The process of formation of reaction products is analyzed based on the concept of a dinuclear system. Isotopic trends of cross sections of production of superheavy nuclei in quasifission reactions are discussed. The yields of new neutron-rich isotopes of nuclei with Z = 64-80 in quasifission reactions are predicted. The mechanism of production of complex fragments in complete fusion and quasifission reactions is analyzed.

  6. Production of the doubly magic nucleus Sn100 in fusion and quasifission reactions via light particle and cluster emission channels

    NASA Astrophysics Data System (ADS)

    Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Wieleczko, J. P.

    2014-08-01

    The possibilities of production of the doubly magic nucleus Sn100 in complete fusion and quasifission reactions with stable and radioactive ion beams are investigated within a dinuclear system model. The excitation functions for production of the exotic nuclei 100-103Sn and 112,114Ba via xn, pxn, αxn, and 12,14Cxn emission channels are predicted for future experiments.

  7. Role of angular momentum in the production of complex fragments in fusion and quasifission reactions

    SciTech Connect

    Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Scheid, W.

    2011-05-15

    The influence of angular momentum on the competition between complete fusion followed by the decay of compound nucleus and quasifission channels is treated within the dinuclear system model. The charge distributions of the products in the reactions {sup 28}Si+{sup 96}Zr, {sup 4}He+{sup 130}Te, and {sup 40}Ca+{sup 82}Kr are predicted at bombarding energies above the Coulomb barrier. The results of calculations for the reactions {sup 93}Nb+{sup 9}Be,{sup 12}C,{sup 27}Al; {sup 84}Kr+{sup 27}Al; {sup 86}Kr+{sup 63}Cu; {sup 139}La+{sup 12}C,{sup 27}Al; and {sup 45}Sc+{sup 65}Cu are compared with the available experimental data.

  8. The Processes of Fusion-Fission and Quasi-Fission of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Bogachev, A. A.; Itkis, I. M.; Kliman, J.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Rusanov, A. Ya.; Sagaidak, R. N.; Behera, B. R.; Corradi, L.; Fioretto, E.; Gadea, A.; Latina, A.; Stefanini, A. M.; Szilner, S.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Trotta, M.; Bouchat, V.; Hanappe, F.; Materna, T.; Dorvaux, O.; Rowley, N.; Schmitt, C.; Stuttge, L.

    2008-11-01

    Results of the experiments aimed at the study of fission and quasi-fission processes in the reactions 48Ca + 144,154Sm, 168Er, 208Pb, 238U, 244Pu, 248Cm; 50Ti + 208Pb, 244Pu; 58Fe + 208Pb, 244Pu, 248Cm, and 64Ni + 186W, 242Pu leading to the formation of heavy and super-heavy systems with Z = 82-122 are presented. Cross sections, mass-energy and angular distributions for fission and quasi-fission fragments have been studied at energies close and below the Coulomb barrier. The influence of the reaction entrance channel properties such as mass asymmetry, deformations, neutron excess, shell effects in the interacting nuclei and producing compound nucleus, the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed.

  9. Fusion and quasi-fission dynamics in nearly-symmetric reactions

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Zhao, Kai; Li, ZhuXia

    2015-11-01

    Some nearly-symmetric fusion reactions are systematically investigated with the improved quantum molecular dynamics (ImQMD) model. By introducing two-body inelastic scattering in the Fermi constraint procedure, the stability of an individual nucleus and the description of fusion cross sections at energies near the Coulomb barrier can be further improved. Simultaneously, the quasifission process in 154Sm+160Gd is also investigated with the microscopic dynamics model for the first time. We find that at energies above the Bass barrier, the fusion probability is smaller than 10-5 for this reaction, and the nuclear contact time is generally smaller than 1500 fm/ c. From the central collisions of Sm+Gd, the neutron-rich fragments such as 164,165Gd, 192W can be produced in the ImQMD simulations, which implies that the quasi-fission reaction could be an alternative way to synthesize new neutron-rich heavy nuclei.

  10. Quasifission and fusion-fission in reactions with massive nuclei: Comparison of reactions leading to the Z=120 element

    SciTech Connect

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Manganaro, M.; Hanappe, F.; Heinz, S.; Hofmann, S.; Muminov, A. I.; Scheid, W.

    2009-02-15

    The yields of evaporation residues, fusion-fission, and quasifission fragments in the {sup 48}Ca+{sup 144,154}Sm and {sup 16}O+{sup 186}W reactions are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues for the {sup 48}Ca+{sup 154}Sm reaction can be well reproduced. The measured yields of fission fragments are decomposed into contributions coming from fusion-fission, quasifission, and fast-fission. The decrease in the measured yield of quasifission fragments in {sup 48}Ca+{sup 154}Sm at the large collision energies and the lack of quasifission fragments in the {sup 48}Ca+{sup 144}Sm reaction are explained by the overlap in mass angle distributions of the quasifission and fusion-fission fragments. The investigation of the optimal conditions for the synthesis of the new element Z=120 (A=302) show that the {sup 54}Cr+{sup 248}Cm reaction is preferable in comparison with the {sup 58}Fe+{sup 244}Pu and {sup 64}Ni+{sup 238}U reactions because the excitation function of the evaporation residues of the former reaction is some orders of magnitude larger than that for the last two reactions.

  11. Fission and Quasifission in the 'Warm' Fusion Reactions

    SciTech Connect

    Itkis, M. G.; Bogachev, A. A.; Chernysheva, E. V.; Itkis, I. M.; Knyazheva, G. N.; Kozulin, E. M.

    2010-06-01

    Mass-energy distributions, as well as capture cross-section of fission-like fragments for the reactions of {sup 48}Ca, {sup 58}Fe and {sup 64}Ni ions with actinides leading to the formation of superheavy compound system with Z = 112-120 at energies near the Coulomb barrier have been measured. Fusion-fission cross sections were estimated from the analysis of mass and total kinetic energy distributions. It was found that the fusion probability is approximately the same for the reactions with {sup 48}Ca ions and drops three orders of magnitude at the transition to {sup 64}Ni ions.

  12. Quasifission at extreme sub-barrier energies

    NASA Astrophysics Data System (ADS)

    Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.; Scheid, W.; Zhang, H. Q.

    2012-12-01

    With the quantum diffusion approach the behavior of the capture cross-section is investigated in the reactions 92, 94Mo + 92, 94Mo , 100Ru + 100Ru , 104Pd + 104Pd , and 78Kr + 112Sn at deep sub-barrier energies which are lower than the ground-state energies of the compound nuclei. Because the capture cross-section is the sum of the complete fusion and quasifission cross-sections, and the complete fusion cross-section is zero at these sub-barrier energies, one can study experimentally the unique quasifission process in these reactions after the capture.

  13. Competing fusion and quasifission reaction mechanisms in the production of superheavy nuclei

    SciTech Connect

    Huang Minghui; Gan Zaiguo; Zhou Xiaohong; Li Junqing; Scheid, W.

    2010-10-15

    Within the framework of a dinuclear system model, a new master equation is constructed and solved, which includes the relative distance of nuclei as a new dynamical variable in addition to the mass asymmetry variable so that the nucleon transfer, which leads to fusion and the evolution of the relative distance, which leads to quasifission (QF) are treated simultaneously in a consistent way. The QF mass yields and evaporation residual cross sections to produce superheavy nuclei are systematically investigated under this framework. The results fit the experimental data well. It is shown that the Kramers formula gives results of QF, which agree with those by our diffusion treatment, only if the QF barrier is high enough. Otherwise some large discrepancies occur.

  14. Quasifission and fusion-fission processes in the reactions 78Kr+40Ca and 86Kr+48Ca at 10 MeV/nucleon bombarding energy

    NASA Astrophysics Data System (ADS)

    Kalandarov, Sh. A.; Lacroix, D.; Adamian, G. G.; Antonenko, N. V.; Wieleczko, J. P.; Pirrone, S.; Politi, G.

    2016-02-01

    Within the dinuclear system model the charge, mass, and isotopic distributions of the products in the reactions 78Kr+40Ca and 86Kr+48Ca are predicted at bombarding energy 10 MeV/nucleon. The heavy-ion phase-space exploration code is applied to take into consideration the pre-equilibrium emission of light particles. The competition is treated between complete fusion followed by the decay of compound nucleus and quasifission channels. The possible explanation of the odd-even staggering in the yield of the final reaction products at high excitation energies is discussed.

  15. Time scale in quasifission reactions

    SciTech Connect

    Back, B.B.; Paul, P.; Nestler, J.

    1995-08-01

    The quasifission process arises from the hindrance of the complete fusion process when heavy-ion beams are used. The strong dissipation in the system tends to prevent fusion and lead the system towards reseparation into two final products of similar mass reminiscent of a fission process. This dissipation slows down the mass transfer and shape transformation and allows for the emission of high energy {gamma}-rays during the process, albeit with a low probability. Giant Dipole {gamma} rays emitted during this time have a characteristic spectral shape and may thus be discerned in the presence of a background of {gamma} rays emitted from the final fission-like fragments. Since the rate of GDR {gamma} emission is very well established, the strength of this component may therefore be used to measure the timescale of the quasifission process. In this experiment we studied the reaction between 368-MeV {sup 58}Ni and a {sup 165}Ho target, where deep inelastic scattering and quasifission processes are dominant. Coincidences between fission fragments (detected in four position-sensitive avalanche detectors) and high energy {gamma} rays (measured in a 10{close_quotes} x 10{close_quotes} actively shielded NaI detector) were registered. Beams were provided by the Stony Brook Superconducting Linac. The {gamma}-ray spectrum associated with deep inelastic scattering events is well reproduced by statistical cooling of projectile and target-like fragments with close to equal initial excitation energy sharing. The y spectrum associated with quasifission events is well described by statistical emission from the fission fragments alone, with only weak evidence for GDR emission from the mono-nucleus. A 1{sigma} limit of t{sub ss} < 11 x 10{sup -21} s is obtained for the mono-nucleus lifetime, which is consistent with the lifetime obtained from quasifission fragment angular distributions. A manuscript was accepted for publication.

  16. Fusion hindrance and quasi-fission in heavy-ion induced reactions: disentangling the effect of different parameters

    SciTech Connect

    Fioretto, E.; Stefanini, A. M.; Behera, B. R.; Corradi, L.; Gadea, A.; Latina, A.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Chizhov, A. Yu.; Itkis, I. M.; Itkis, M. G.; Kniajeva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Pokrovsky, I. V.; Sagaidak, R. N.; Voskressensky, V. M.; Courtin, S.

    2006-04-26

    Experimental results on the fusion inhibition effect near the Coulomb barrier due to the onset of the quasi-fission mechanism are presented. The investigation was focused on reactions induced by 48Ca projectiles on different heavy targets and comparing them to reactions induced by light ions such as 12C and 16O leading to the same compound nuclei. Cross sections and angular distributions of evaporation residues and fission fragments have been measured.

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

    SciTech Connect

    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.

  18. The fusion fission and quasi-fission processes in the reaction 48Ca + 208Pb at energies near the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Prokhorova, E. V.; Bogachev, A. A.; Itkis, M. G.; Itkis, I. M.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Pashkevich, V. V.; Rusanov, A. Ya.

    2008-04-01

    Mass-energy distributions (MEDs) and capture-fission cross sections have been measured in the reaction 48Ca + 208Pb → 256No at the energies E=206-242 MeV using a double-arm time-of-flight spectrometer CORSET. It has been observed that MED of the fragments consists of two parts, namely, the classical fusion-fission process corresponding to the symmetric fission of 256No and quasi-fission "shoulders" corresponding to the light fragment masses ˜60-90 u and complimentary heavy fragment masses. The quasi-fission "shoulders" have a higher total kinetic energy (TKE) as compared with that expected for the classical fission. A mathematical formalism was employed for the MEDs fragment decomposition into fusion-fission and quasi-fission components. In the fusion-fission process a high-energy Super-Short mode has been discovered for the masses M=130-135 u and the TKE of ≈233 MeV.

  19. Competition between fusion-fission and quasifission processes in the {sup 32}S+{sup 184}W reaction

    SciTech Connect

    Zhang, H. Q.; Zhang, C. L.; Lin, C. J.; Liu, Z. H.; Yang, F.; Nasirov, A. K.; Mandaglio, G.; Manganaro, M.; Giardina, G.

    2010-03-15

    The angular distributions of fission fragments for the {sup 32}S+{sup 184}W reaction at center-of-mass energies of 118.8, 123.1, 127.3, 131.5, 135.8, 141.1, and 144.4 MeV are measured. The experimental fission excitation function is obtained. The anisotropy (A{sub exp}) is found by extrapolating each fission fragment angular distribution. The measured fission cross sections of the {sup 32}S+{sup 182,184}W reaction are decomposed into fusion-fission, quasifission, and fast-fission contributions by the dinuclear system model (DNS). The angular momentum distributions of the dinuclear system and compound nucleus calculated by the DNS model are used to reproduce the experimental capture and fusion excitation functions for both reactions and quantities K{sub 0}{sup 2}, , and A{sub exp}, which characterize angular distributions of the fission products at the considered range of beam energy. The total evaporation residue excitation function for the {sup 32}S+{sup 184}W reaction calculated in the framework of the advanced statistical model is close to the available experimental data only up to about E{sub c.m.}approx =160 MeV. The underestimation of the experimental data at high excitation energies E{sub c.m.}>160 MeV is explained by the fact that the statistical model cannot reproduce the cross section of evaporation residues formed by the nonequilibrium mechanism, that is, without formation of the compound nucleus in the statistical equilibrium state.

  20. Fusion and quasifission dynamics in the reactions 48Ca+249Bk and 50Ti+249Bk using a time-dependent Hartree-Fock approach

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Simenel, C.

    2016-08-01

    Background: Synthesis of superheavy elements (SHEs) with fusion-evaporation reactions is strongly hindered by the quasifission (QF) mechanism which prevents the formation of an equilibrated compound nucleus and which depends on the structure of the reactants. New SHEs have been recently produced with doubly-magic 48Ca beams. However, SHE synthesis experiments with single-magic 50Ti beams have so far been unsuccessful. Purpose: In connection with experimental searches for Z =117 ,119 superheavy elements, we perform a theoretical study of fusion and quasifission mechanisms in 48Ca,50Ti+249Bk reactions in order to investigate possible differences in reaction mechanisms induced by these two projectiles. Methods: The collision dynamics and the outcome of the reactions are studied using unrestricted time-dependent Hartree-Fock (TDHF) calculations as well as the density-constrained TDHF method to extract the nucleus-nucleus potentials and the excitation energy in each fragment. Results: Nucleus-nucleus potentials, nuclear contact times, masses and charges of the fragments, as well as their kinetic and excitation energies strongly depend on the orientation of the prolate 249Bk nucleus. Long contact times associated with fusion are observed in collisions of both projectiles with the side of the 249Bk nucleus, but not on collisions with its tip. The energy and impact parameter dependencies of the fragment properties, as well as their mass-angle and mass-total kinetic energy correlations are investigated. Conclusions: Entrance channel reaction dynamics are similar with both 48Ca and 50Ti projectiles. Both are expected to lead to the formation of a compound nucleus by fusion if they have enough energy to get in contact with the side of the 249Bk target.

  1. Multinucleon exchange in quasifission reactions

    NASA Astrophysics Data System (ADS)

    Ayik, S.; Yilmaz, B.; Yilmaz, O.

    2015-12-01

    The nucleon exchange mechanism is investigated in the central collisions of 40Ca+238U and 48Ca+238U systems near the quasifission regime in the framework of the stochastic mean-field (SMF) approach. Sufficiently below the fusion barrier, a dinuclear structure in the collisions is maintained to a large extent. Consequently, it is possible to describe nucleon exchange as a diffusion process familiar from deep-inelastic collisions. Diffusion coefficients for proton and neutron exchange are determined from the microscopic basis of the SMF approach in the semiclassical framework. Calculations show that after a fast charge equilibration the system drifts toward symmetry over a very long interaction time. Large dispersions of proton and neutron distributions of the produced fragments indicate that the diffusion mechanism may help to populate heavy transuranium elements near the quasifission regime in these collisions.

  2. Dynamics of quasifission

    SciTech Connect

    Umar, A. S. Oberacker, V. E.; Simenel, C.

    2015-10-15

    Quasifission is the primary reaction mechanism that limits the formation of superheavy nuclei and consequently an important ingredient for choosing the best target-projectile combinations for the heavy element searches. Quasifission is characterized by nuclear contact-times that are much longer than those found in deep-inelastic reactions, resulting in a substantial mass and charge transfer. In this manuscript we employ the fully microscopic time-dependent Hartree-Fock (TDHF) theory to study quasifission. New results are presented for the {sup 48}Ca+{sup 249}Bk system.

  3. Production of unknown transactinides in asymmetry-exit-channel quasifission reactions

    SciTech Connect

    Adamian, G.G.; Antonenko, N. V.; Zubov, A. S.

    2005-03-01

    Possibilities of production of new isotopes of superheavy nuclei with charge numbers 104-108 in asymmetry-exit-channel quasifission reactions are studied for the first time. The optimal conditions for the synthesis are suggested in this type of reaction. The products of suggested reactions can fill a gap of unknown isotopes between the isotopes of heaviest nuclei obtained in cold and hot complete fusion reactions.

  4. Dinuclear systems in complete fusion reactions

    NASA Astrophysics Data System (ADS)

    Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.

    2014-09-01

    Formation and evolution of dinuclear systems in reactions of complete fusion are considered. Based on the dinuclear system concept, the process of compound nucleus formation is studied. Arguments confirming the validity of this concept are given. The main problems of describing the complete fusion in adiabatic approximation are listed. Calculations of evaporation residue cross sections in complete fusion reactions leading to formation of superheavy nuclei are shown. Isotopic trends of the cross sections of heavy nuclei formation in complete fusion reactions are considered.

  5. Quasifission processes in {sup 40,48}Ca+{sup 144,154}Sm reactions

    SciTech Connect

    Knyazheva, G. N.; Kozulin, E. M.; Sagaidak, R. N.; Chizhov, A. Yu.; Itkis, M. G.; Kondratiev, N. A.; Voskressensky, V. M.; Stefanini, A. M.; Behera, B. R.; Corradi, L.; Fioretto, E.; Gadea, A.; Latina, A.; Szilner, S.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Haas, F.; Rowley, N.

    2007-06-15

    Mass-energy and angular distributions of fission fragments for the {sup 48}Ca+{sup 144,154}Sm{yields}{sup 192,202}Pb, {sup 40}Ca+{sup 154}Sm{yields}{sup 194}Pb reactions have been measured. Fusion suppression and the presence of quasifission at energies near and below the Coulomb barrier have been observed for the reactions with the deformed target {sup 154}Sm. In the case of the spherical {sup 144}Sm target no evidence of quasifission has been found. Quasifission cross sections have been extracted from total fission-like events by analysis of their mass and angular distributions.

  6. Systematic study of quasifission characteristics and timescales in heavy element formation reactions

    NASA Astrophysics Data System (ADS)

    Hinde, D. J.; Williams, E.; Mohanto, G.; Simenel, C.; Dasgupta, M.; Wakhle, A.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; Palshetkar, C. S.; Prasad, E.; Rafferty, D. C.; du Rietz, R.; Simpson, E. C.

    2016-05-01

    Superheavy elements can only be created in the laboratory by the fusion of two massive nuclei. Mass-angle distributions give the most direct information on the characteristics and time scales of quasifission, the major competitor to fusion in these reactions. The systematics of 42 mass-angle distributions provide information on the global characteristics of quasifission. Deviations from the systematics reveal the major role played by the nuclear structure of the two colliding nuclei in determining the reaction outcome, and in hindering or favouring heavy element production.

  7. Complete fusion of 15N+27Al

    NASA Astrophysics Data System (ADS)

    Prosser, F. W., Jr.; Racca, R. A.; Daneshvar, K.; Geesaman, D. F.; Henning, W.; Kovar, D. G.; Rehm, K. E.; Tabor, S. L.

    1980-05-01

    The total fusion cross section for the system 15N + 27Al has been measured over an energy range 27 MeV<=Elab<=70 MeV by detection of the fusion-evaporation residues. In addition elastic scattering was measured at six energies and fitted by optical model calculations. The fusion cross section for the system saturates at 1150+/-50 mb. The data can be well described by the model of Glas and Mosel, using a reasonable set of parameters. The model of Horn and Ferguson also describes the data well if an appropriate charge radius is used. Comparison is made between these results and the fusion cross sections for 16O + 26Mg and 18O + 24Mg, which lead to the same compound nucleus. The results for 15N + 27Al are quite similar to those for 18O + 24Mg, and the differences between the fusion cross sections for these two systems and those for 16O + 26Mg may be evidence for an entrance channel effect. NUCLEAR REACTIONS 15N+27Al, Elab=27-70 MeV; measured σfusion(E) measured dσdΩ elastic scattering; data fitted with Glas and Mosel model, Horn and Ferguson model.

  8. Shape evolution and collective dynamics of quasifission in the time-dependent Hartree-Fock approach

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Simenel, C.

    2015-08-01

    Background: At energies near the Coulomb barrier, capture reactions in heavy-ion collisions result either in fusion or in quasifission. The former produces a compound nucleus in statistical equilibrium, while the second leads to a reseparation of the fragments after partial mass equilibration without formation of a compound nucleus. Extracting the compound nucleus formation probability is crucial to predict superheavy-element formation cross sections. It requires a good knowledge of the fragment angular distribution which itself depends on quantities such as moments of inertia and excitation energies which have so far been somewhat arbitrary for the quasifission contribution. Purpose: Our main goal is to utilize the time-dependent Hartee-Fock (TDHF) approach to extract ingredients of the formula used in the analysis of experimental angular distributions. These include the moment-of-inertia and temperature. Methods: We investigate the evolution of the nuclear density in TDHF calculations leading to quasifission. We study the dependence of the relevant quantities on various initial conditions of the reaction process. Results: The evolution of the moment of inertia is clearly nontrivial and depends strongly on the characteristics of the collision. The temperature rises quickly when the kinetic energy is transformed into internal excitation. Then, it rises slowly during mass transfer. Conclusions: Fully microscopic theories are useful to predict the complex evolution of quantities required in macroscopic models of quasifission.

  9. Description of the Fusion-Fission Reactions in the Framework of Dinuclear System Conception

    NASA Astrophysics Data System (ADS)

    Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Wieleczko, J. P.

    2016-05-01

    Within the dinuclear system model fusion-fission reactions 78Kr+40Ca and 86Kr+48Ca is investigated. The charge distributions of the decay products are predicted at bombarding energy 10 MeV/nucleon. The competition is treated between complete fusion followed by the decay of compound nucleus and quasifission channels. The possible explanation of the odd-even staggering in the yield of the final reaction products at high excitation energies is discussed.

  10. Fusion of massive nuclei and synthesis of superheavy elements in the framework of the DNS concept

    SciTech Connect

    Cherepanov, E. A.; Adamian, G. G.; Volkov, V. V.; Antonenko, N. V.

    1998-02-15

    The dinuclear system (DNS) concept of formation of compound nuclei has been applied to analysis the conditions necessary to synthesize superheavy elements (SHE). For elements 110-114 the inner fusion barriers have been calculated. Thus, it has become possible to estimate the optimal collision kinetic energy. Using the model of competition between complete fusion and quasi-fission, the formation probability of a compound nucleus in element 110-114 synthesis reactions has been calculated.

  11. Critical energy deposit in heavy ion complete fusion

    SciTech Connect

    Fonte, R.; Insolia, A. Dipartimento di Fisica dell'Universita di Catania corso Italia, 57-95129 Catania, Italy)

    1991-07-01

    In the framework of an {ital l}-window model for complete fusion reactions within a sharp cutoff approximation, the problem of the maximum excitation energy which can be deposited in a compound nucleus is discussed. Predictions about the spin distribution of the compound nucleus are compared with the conclusions of a recent analysis of the {sup 28}Si+{sup 28}Si fusion reaction.

  12. Complete fusion of {sup 9}Be with spherical targets.

    SciTech Connect

    Esbensen, H.; Physics

    2010-01-01

    The complete fusion of {sup 9}Be with {sup 144}Sm and {sup 208}Pb targets is calculated in the coupled-channels approach. The calculations include couplings among the 3/2{sup -}, 5/2{sup -}, and 7/2{sup -} states in the K=3/2 ground-state rotational band of {sup 9}Be. It is shown that the B(E2) values for the excitation of these states are accurately described in the rotor model. The interaction of the strongly deformed {sup 9}Be nucleus with a spherical target is calculated using the double-folding technique and the effective M3Y interaction, which is supplemented with a repulsive term that is adjusted to optimize the fit to the data for the {sup 144}Sm target. The complete fusion is described by ingoing-wave boundary conditions. The decay of the unbound excited states in {sup 9}Be is considered explicitly in the calculations by using complex excitation energies. The model gives an excellent account of the complete fusion (CF) data for {sup 9}Be+{sup 144}Sm, and the cross sections for the decay of the excited states are in surprisingly good agreement with the incomplete fusion (ICF) data. Similar calculations for {sup 9}Be+{sup 208}Pb explain the total fusion data at high energies but fail to explain the CF data, which are suppressed by 20%, and the calculated cross section for the decay of excited states is a factor of 3 smaller than the ICF data at high energies. Possible reasons for these discrepancies are discussed.

  13. Complete fusion of {sup 9}Be with spherical targets

    SciTech Connect

    Esbensen, Henning

    2010-03-15

    The complete fusion of {sup 9}Be with {sup 144}Sm and {sup 208}Pb targets is calculated in the coupled-channels approach. The calculations include couplings among the 3/2{sup -}, 5/2{sup -}, and 7/2{sup -} states in the K=3/2 ground-state rotational band of {sup 9}Be. It is shown that the B(E2) values for the excitation of these states are accurately described in the rotor model. The interaction of the strongly deformed {sup 9}Be nucleus with a spherical target is calculated using the double-folding technique and the effective M3Y interaction, which is supplemented with a repulsive term that is adjusted to optimize the fit to the data for the {sup 144}Sm target. The complete fusion is described by ingoing-wave boundary conditions. The decay of the unbound excited states in {sup 9}Be is considered explicitly in the calculations by using complex excitation energies. The model gives an excellent account of the complete fusion (CF) data for {sup 9}Be+{sup 144}Sm, and the cross sections for the decay of the excited states are in surprisingly good agreement with the incomplete fusion (ICF) data. Similar calculations for {sup 9}Be+{sup 208}Pb explain the total fusion data at high energies but fail to explain the CF data, which are suppressed by 20%, and the calculated cross section for the decay of excited states is a factor of 3 smaller than the ICF data at high energies. Possible reasons for these discrepancies are discussed.

  14. Compound nucleus formation in reactions between massive nuclei: Fusion barrier

    SciTech Connect

    Antonenko, N.V.; Cherepanov, E.A.; Nasirov, A.K.; Permjakov, V.P.; Volkov, V.V.

    1995-05-01

    The evaporation residue cross sections {sigma}{sub ER} in reactions between massive nuclei have been analyzed within different models of complete fusion. The calculations in the framework of the optical model, the surface friction model, and the macroscopic dynamic model can give the results which are by few orders of magnitude different from experimental data. This takes place due to neglect of the competition between complete fusion and quasifission. A possible mechanism of compound nucleus formation in heavy-ion-induced reactions has been suggested. The analysis of the complete fusion of nuclei on the basis of dinuclear system approach has allowed one to reveal an important feature of the fusion process of massive nuclei, that is, the appearance of the fusion barrier during dinuclear system evolution to a compound nucleus. As a result, the competition between complete fusion and quasifission arises and strongly reduces the cross section of the compound nucleus formation. A model is proposed for calculation of this competition in a massive symmetric dinuclear system. This model is applied for collision energies above the Coulomb barrier. The {sigma}{sub ER} values calculated in the framework of dinuclear system approach seem to be close to the experimental data. For illustration the reactions {sup 100}Mo+{sup 100}Mo, {sup 110}Pd+{sup 110}Pd, and {sup 124}Sn+{sup 96}Zr have been considered.

  15. Complete fusion of 19F with Al and Si isotopes

    NASA Astrophysics Data System (ADS)

    Chiou, M. S.; Wu, M. W.; Easwar, N.; Maher, J. V.

    1981-12-01

    Complete fusion cross sections have been determined by directly detecting evaporation residuals for the systems 19F + 27Al and 19F + 28,30Si over a 19F laboratory energy range 34-75 MeV. In all cases σfus increases smoothly with energy and eventually saturates at 1200-1250 mb. In the barrier penetration region the cross section for 19F + 28Si is always sufficiently smaller than that for 19F + 30Si to make the reduced barrier radius in a Glas-Mosel parametrization significantly smaller for the former system than for the latter. Three entrance channels are now available for the fused-system 46Ti: Critical angular momentum data from the 16O + 30Si entrance channel approach the statistical yrast line at much lower fused-system excitation energy than do the data from the entrance channels 18O + 28Si and 19F + 27Al. NUCLEAR REACTIONS Measured complete fusion cross sections for the systems 19F + 27Al, 19F + 28Si, 19F + 30Si; E=34-75 MeV. Deduced Glas-Mosel model and statistical yrast model parameters.

  16. Fission and quasifission modes in heavy-ion-induced reactions leading to the formation of Hs{sup *}

    SciTech Connect

    Itkis, I. M.; Kozulin, E. M.; Itkis, M. G.; Knyazheva, G. N.; Bogachev, A. A.; Chernysheva, E. V.; Krupa, L.; Oganessian, Yu. Ts.; Zagrebaev, V. I.; Rusanov, A. Ya.; Goennenwein, F.; Dorvaux, O.; Stuttge, L.; Hanappe, F.; Vardaci, E.; Goes Brennand, E. de

    2011-06-15

    Mass and energy distributions of binary reaction products obtained in the reactions {sup 22}Ne+{sup 249}Cf,{sup 26}Mg+{sup 248}Cm, {sup 36}S+{sup 238}U, and {sup 58}Fe+{sup 208}Pb have been measured. All reactions lead to Hs isotopes. At energies below the Coulomb barrier the bimodal fission of Hs{sup *}, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed. In the reaction {sup 36}S+{sup 238}U, leading to the formation of a similar compound nucleus, the main part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier fusion-fission is the main process leading to the formation of symmetric fragments for both reactions with Mg and S ions. In the case of the {sup 58}Fe+{sup 208}Pb reaction the quasifission process dominates at all measured energies.

  17. Shell effects in fission and quasi-fission of heavy and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; A¨ysto¨, J.; Beghini, S.; Bogachev, A. A.; Corradi, L.; Dorvaux, O.; Gadea, A.; Giardina, G.; Hanappe, F.; Itkis, I. M.; Jandel, M.; Kliman, J.; Khlebnikov, S. V.; Kniajeva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Latina, A.; Materna, T.; Montagnoli, G.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Rowley, N.; Rubchenya, V. A.; Rusanov, A. Ya.; Sagaidak, R. N.; Scarlassara, F.; Stefanini, A. M.; Stuttge, L.; Szilner, S.; Trotta, M.; Trzaska, W. H.; Vakhtin, D. N.; Vinodkumar, A. M.; Voskressenski, V. M.; Zagrebaev, V. I.

    2004-04-01

    Results of the experiments aimed at the study of fission and quasi-fission processes in the reactions 12C+ 204Pb, 48Ca+ 144,154Sm, 168Er, 208Pb, 244Pu, 248Cm; 58Fe+ 208Pb, 244Pu, 248Cm, and 64Ni+ 186W, 242Pu are presented in the work. The choice of the above-mentioned reactions was inspired by recent experiments on the production of the isotopes 283112, 289114 and 283116 at Dubna [1],[2] using the same reactions. The 58Fe and 64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) and the Accelerator of the Laboratory of University of Jyvaskyla (JYFL, Finland) using the time-of-flight spectrometer of fission fragments CORSET[3] and the neutron multi-detector DEMON[4],[5]. The role of shell effects and the influence of the entrance channel on the mechanism of the compound nucleus fusion-fission and the competitive process of quasi-fission are discussed.

  18. Production of exotic isotopes in complete fusion reactions with radioactive beams

    NASA Astrophysics Data System (ADS)

    Sargsyan, V. V.; Zubov, A. S.; Adamian, G. G.; Antonenko, N. V.; Heinz, S.

    2013-11-01

    The isotopic dependence of the complete fusion (capture) cross section is analyzed in the reactions 130,132,134,136,138,140,142,144,146,148,150Xe+48Ca with stable and radioactive beams. It is shown for the first time that the very neutron-rich nuclei 186-191W can be reached with relatively large cross sections by complete fusion reactions with radioactive ion beams at incident energies near the Coulomb barrier. A comparison between the complete fusion and fragmentation reactions for the production of neutron-rich W and neutron-deficient Rn isotopes is performed.

  19. Fission following complete fusion for {sup 16}O + {sup 232}Th at 140 MeV

    SciTech Connect

    Frawley, A.D.

    1995-09-01

    Previously published results of coincidence measurements between incomplete fusion products and fission fragments from the reaction of 140 MeV {sup 16}O with {sup 232}Th have been used to determine the incomplete fusion contributions to the inclusive fission fragment angular distribution. The incomplete fusion contributions have been subtracted from the inclusive angular distribution, leaving the part due to complete fusion. Because the incomplete fusion processes account for 42% of the fission cross section, the maximum angular momentum contributing to complete fusion is reduced to approximately 55{h_bar}. The angular distribution for fission following complete fusion has been compared with calculations made with the saddle point transition state model and with Bond`s scission point model. When proper account is taken of the large reduction in nuclear temperature at the saddle point due to pre-fission neutron evaporation, the saddle point transition state model reproduces the data very well. Proper handling of the incomplete fusion contributions is found to greatly improve the agreement of Bond`s scission point model with the data for this reaction.

  20. Search for systematic behavior of incomplete-fusion probability and complete-fusion suppression induced by {sup 9}Be on different targets

    SciTech Connect

    Gomes, P. R. S.; Linares, R.; Lubian, J.; Lopes, C. C.; Cardozo, E. N.; Pereira, B. H. F.

    2011-07-15

    We present a trial to obtain a systematic behavior of the results available in the literature on the complete and incomplete fusion induced by the weakly bound projectile {sup 9}Be on targets with different masses and/or charges. We stress that although the incomplete-fusion probability and the complete-fusion suppression are very closely related quantities, the first is an experimental value whereas the later is model dependent. A trend of systematic behavior for the incomplete-fusion probability as a function of the target charge is achieved, but not for the complete-fusion suppression.

  1. Systematical Behavior of Breakup Effects on Complete Fusion at Energies above the Coulomb Barrier

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Zhao, Wei-Juan; Gomes, P. R. S.; Zhao, En-Guang; Zhou, Shan-Gui

    We investigate the systematical behavior of the breakup effects on the complete fusion (CF) cross sections at energies above the Coulomb barrier. The CF cross sections are suppressed by the prompt breakup of the projectiles. This suppression effect, expressed as the ratio of the reduced fusion function and the universal fusion function (UFF), for reactions induced by the same projectile, is independent of the target and mainly determined by the lowest energy breakup channel of the projectile. There holds a good exponential relation between the suppression factor and the energy corresponding to the lowest breakup threshold.

  2. Influence of incomplete fusion on complete fusion: Observation of a large incomplete fusion fraction at E {approx_equal}5-7 MeV/nucleon

    SciTech Connect

    Singh, Pushpendra P.; Singh, B. P.; Sharma, Manoj Kumar; Unnati,; Singh, Devendra P.; Prasad, R.; Kumar, Rakesh; Golda, K. S.

    2008-01-15

    Experiments have been carried out to explore the reaction dynamics leading to incomplete fusion of heavy ions at moderate excitation energies. Excitation functions for {sup 168}Lu{sup m}, {sup 167}Lu, {sup 167}Yb, {sup 166}Tm, {sup 179}Re, {sup 177}Re, {sup 177}W, {sup 178}Ta, and {sup 177}Hf radio-nuclides populated via complete and/or incomplete fusion of {sup 16}O with {sup 159}Tb and {sup 169}Tm have been studied over the wide projectile energy range E{sub proj}{approx_equal}75-95 MeV. Recoil-catcher technique followed by off-line {gamma}-spectrometry has been employed in the present measurements. Experimental data have been compared with the predictions of theoretical model code PACE2. The experimentally measured production cross sections of {alpha}-emitting channels were found to be larger as compared to the theoretical model predictions and may be attributed to incomplete fusion at these energies. During the analysis of experimental data, incomplete fusion has been found to be competing with complete fusion. As such, an attempt has been made to estimate the incomplete fusion fraction for both the systems, and has been found to be sensitive for projectile energy and mass asymmetry of interacting partners.

  3. Probing systematic model dependence of complete fusion for reactions with the weakly bound projectiles Li,76

    NASA Astrophysics Data System (ADS)

    Kundu, A.; Santra, S.; Pal, A.; Chattopadhyay, D.; Nayak, B. K.; Saxena, A.; Kailas, S.

    2016-07-01

    Background: Complete fusion cross section measurements involving weakly bound projectiles show suppression at above-barrier energies compared to coupled-channels (CC) calculations, but no definite conclusion could be drawn for sub-barrier energies. Different CC models often lead to contrasting results. Purpose: We aim to investigate the differences in the fusion cross sections predicted by commonly used CC calculations, using codes such as fresco and ccfull, when compared to experimental data. Methods: The fusion cross sections are normalized to a dimensionless form by isolating the effect of only dynamic channel couplings calculated by both fresco and ccfull, by the method of fusion functions, and compared to a universal fusion function. This acts as a probe for obtaining the model dependence of fusion. Results: A difference is observed between the predictions of fresco and ccfull for all the reactions involving Li,76 as projectiles, and it is noticeably more for systems involving 7Li. Conclusions: With the theoretical foundations of the two CC models being different, their calculation of fusion is different even for the same system. The conclusion about the enhancement or suppression of fusion cross sections is model dependent.

  4. Pixel-level multisensor image fusion based on matrix completion and robust principal component analysis

    NASA Astrophysics Data System (ADS)

    Wang, Zhuozheng; Deller, J. R.; Fleet, Blair D.

    2016-01-01

    Acquired digital images are often corrupted by a lack of camera focus, faulty illumination, or missing data. An algorithm is presented for fusion of multiple corrupted images of a scene using the lifting wavelet transform. The method employs adaptive fusion arithmetic based on matrix completion and self-adaptive regional variance estimation. Characteristics of the wavelet coefficients are used to adaptively select fusion rules. Robust principal component analysis is applied to low-frequency image components, and regional variance estimation is applied to high-frequency components. Experiments reveal that the method is effective for multifocus, visible-light, and infrared image fusion. Compared with traditional algorithms, the new algorithm not only increases the amount of preserved information and clarity but also improves robustness.

  5. Systematic study of suppression of complete fusion in reactions involving weakly bound nuclei at energies above the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Zhao, Wei-Juan; Diaz-Torres, Alexis; Zhao, En-Guang; Zhou, Shan-Gui

    2016-01-01

    Complete fusion excitation functions of reactions involving breakup are studied by using the empirical coupled-channel (ECC) model with breakup effects considered. An exponential function with two parameters is adopted to describe the prompt-breakup probability in the ECC model. These two parameters are fixed by fitting the measured prompt-breakup probability or the complete fusion cross sections. The suppression of complete fusion at energies above the Coulomb barrier is studied by comparing the data with the predictions from the ECC model without the breakup channel considered. The results show that the suppression of complete fusion is roughly independent of the target for the reactions involving the same projectile.

  6. Expected production of new exotic α emitters 108Xe and 112Ba in complete fusion reactions

    NASA Astrophysics Data System (ADS)

    Kalandarov, Sh. A.; Adamian, G. G.; Antonenko, N. V.; Wieleczko, J. P.

    2016-05-01

    The production cross sections of neutron-deficient isotopes Xe-110108 and Ba-114112 in the complete fusion reactions Ni,5658+54Fe and Ni,5658+58Ni with stable and radioactive beams are studied with the dinuclear system model. The calculated results are compared with the available experimental data. The optimal beam energies and corresponding maximum production cross sections of new isotopes 108Xe and 112Ba are predicted.

  7. A transversal approach for patch-based label fusion via matrix completion.

    PubMed

    Sanroma, Gerard; Wu, Guorong; Gao, Yaozong; Thung, Kim-Han; Guo, Yanrong; Shen, Dinggang

    2015-08-01

    Recently, multi-atlas patch-based label fusion has received an increasing interest in the medical image segmentation field. After warping the anatomical labels from the atlas images to the target image by registration, label fusion is the key step to determine the latent label for each target image point. Two popular types of patch-based label fusion approaches are (1) reconstruction-based approaches that compute the target labels as a weighted average of atlas labels, where the weights are derived by reconstructing the target image patch using the atlas image patches; and (2) classification-based approaches that determine the target label as a mapping of the target image patch, where the mapping function is often learned using the atlas image patches and their corresponding labels. Both approaches have their advantages and limitations. In this paper, we propose a novel patch-based label fusion method to combine the above two types of approaches via matrix completion (and hence, we call it transversal). As we will show, our method overcomes the individual limitations of both reconstruction-based and classification-based approaches. Since the labeling confidences may vary across the target image points, we further propose a sequential labeling framework that first labels the highly confident points and then gradually labels more challenging points in an iterative manner, guided by the label information determined in the previous iterations. We demonstrate the performance of our novel label fusion method in segmenting the hippocampus in the ADNI dataset, subcortical and limbic structures in the LONI dataset, and mid-brain structures in the SATA dataset. We achieve more accurate segmentation results than both reconstruction-based and classification-based approaches. Our label fusion method is also ranked 1st in the online SATA Multi-Atlas Segmentation Challenge. PMID:26160394

  8. Fission barriers for Po nuclei produced in complete fusion reactions with heavy ions

    SciTech Connect

    Sagaidak, R. N.; Andreyev, A. N.

    2009-05-15

    Evaporation residues and fission excitation functions obtained in complete fusion reactions leading to Po compound nuclei have been analyzed in the framework of the standard statistical model. Macroscopic fission barriers deduced from the cross-section data analysis are compared with the predictions of various theoretical models and available data. A drop in the Po barriers with the decrease in a neutron number was found, which is stronger than predicted by any theory. The presence of entrance channel effects and collective excitations in the compound nucleus decay is considered as a possible reason for the barrier reduction.

  9. Importance of lifetime effects in breakup and suppression of complete fusion in reactions of weakly bound nuclei

    NASA Astrophysics Data System (ADS)

    Cook, K. J.; Simpson, E. C.; Luong, D. H.; Kalkal, Sunil; Dasgupta, M.; Hinde, D. J.

    2016-06-01

    Background: Complete fusion cross sections in collisions of light weakly bound nuclei and high-Z targets show suppression of complete fusion at above-barrier energies. This has been interpreted as resulting from the breakup of the weakly bound nucleus prior to reaching the fusion barrier, reducing the probability of complete charge capture. Below-barrier studies of reactions of 9Be have found that the breakup of 8Be formed by neutron stripping dominates over direct breakup and that transfer-triggered breakup may account for the observed suppression of complete fusion. Purpose: This paper investigates how the above conclusions are affected by lifetimes of the resonant states that are populated prior to breakup. If the mean life of a populated resonance (above the breakup threshold) is much longer than the fusion time scale, then its breakup (decay) cannot suppress complete fusion. For short-lived resonances, the situation is more complex. This work explicitly includes the mean life of the short-lived 2+ resonance in 8Be in classical dynamical model calculations to determine its effect on energy and angular correlations of the breakup fragments and on model predictions of suppression of cross sections for complete fusion at above-barrier energies. Method: Previously performed coincidence measurements of breakup fragments produced in reactions of 9Be with 144Sm, 168Er, 186W, 196Pt, 208Pb, and 209Bi at energies below the barrier have been reanalyzed using an improved efficiency determination of the BALiN detector array. Predictions of breakup observables and of complete and incomplete fusion at energies above the fusion barrier are then made using the classical dynamical simulation code platypus, modified to include the effect of lifetimes of resonant states. Results: The agreement of the breakup observables is much improved when lifetime effects are included explicitly. Sensitivity to subzeptosecond lifetime is observed. The predicted suppression of complete fusion

  10. Hindrance of complete fusion in the {sup 8}Li+{sup 208}Pb system at above-barrier energies

    SciTech Connect

    Aguilera, E. F.; Martinez-Quiroz, E.; Rosales, P.; Kolata, J. J.; DeYoung, P. A.; Peaslee, G. F.; Mears, P.; Guess, C.; Becchetti, F. D.; Lupton, J. H.; Chen, Yu

    2009-10-15

    The {sup 211,212}At yields resulting from the interaction of the radioactive projectile {sup 8}Li with a {sup 208}Pb target have been measured at energies between 3 and 8.5 MeV above the Coulomb barrier. They are signatures for fusion of the whole charge but not necessarily the whole mass of the projectile, so they are included in a corresponding operational definition of complete fusion. Within this definition, a fusion suppression factor of 0.70{+-}0.02 (stat.) {+-}0.04 (syst.) is deduced from a comparison to a one-dimensional barrier-penetration-model calculation using parameters extrapolated from values for {sup 6,7}Li+{sup 209}Bi and {sup 9}Be+{sup 208}Pb taken from the literature. Possible incomplete fusion processes are discussed and the results are fitted with a phenomenological model assuming breakup prior to fusion followed by capture of a {sup 7}Li fragment.

  11. Inhibition of HIV-1 endocytosis allows lipid mixing at the plasma membrane, but not complete fusion

    PubMed Central

    2011-01-01

    Background We recently provided evidence that HIV-1 enters HeLa-derived TZM-bl and lymphoid CEMss cells by fusing with endosomes, whereas its fusion with the plasma membrane does not proceed beyond the lipid mixing step. The mechanism of restriction of HIV-1 fusion at the cell surface and/or the factors that aid the virus entry from endosomes remain unclear. Results We examined HIV-1 fusion with a panel of target cells lines and with primary CD4+ T cells. Kinetic measurements of fusion combined with time-resolved imaging of single viruses further reinforced the notion that HIV-1 enters the cells via endocytosis and fusion with endosomes. Furthermore, we attempted to deliberately redirect virus fusion to the plasma membrane, using two experimental strategies. First, the fusion reaction was synchronized by pre-incubating the viruses with cells at reduced temperature to allow CD4 and coreceptors engagement, but not the virus uptake or fusion. Subsequent shift to a physiological temperature triggered accelerated virus uptake followed by entry from endosomes, but did not permit fusion at the cell surface. Second, blocking HIV-1 endocytosis by a small-molecule dynamin inhibitor, dynasore, resulted in transfer of viral lipids to the plasma membrane without any detectable release of the viral content into the cytosol. We also found that a higher concentration of dynasore is required to block the HIV-endosome fusion compared to virus internalization. Conclusions Our results further support the notion that HIV-1 enters disparate cell types through fusion with endosomes. The block of HIV-1 fusion with the plasma membrane at a post-lipid mixing stage shows that this membrane is not conducive to fusion pore formation and/or enlargement. The ability of dynasore to interfere with the virus-endosome fusion suggests that dynamin could be involved in two distinct steps of HIV-1 entry - endocytosis and fusion within intracellular compartments. PMID:22145853

  12. Transfer-type products accompanying cold fusion reactions

    SciTech Connect

    Adamian, G.G.; Antonenko, N.V.

    2005-12-15

    Production of nuclei heavier than the target is treated for projectile-target combinations used in cold fusion reactions leading to superheavy nuclei. These products are related to transfer-type or to asymmetry-exit-channel quasifission reactions. The production of isotopes in the transfer-type reactions emitting of {alpha} particles with large energies is discussed.

  13. Investigation of complete and incomplete fusion dynamics of {sup 20}Ne induced reactions at energies above the Coulomb barrier

    SciTech Connect

    Singh, D.; Ali, R.; Kumar, Harish; Ansari, M. Afzal; Rashid, M. H.; Guin, R.

    2014-08-14

    Experiment has been performed to explore the complete and incomplete fusion dynamics in heavy ion collisions using stacked foil activation technique. The measurement of excitation functions of the evaporation residues produced in the {sup 20}Ne+{sup 165}Ho system at projectile energies ranges ≈ 4-8 MeV/nucleon have been done. Measured cumulative and direct cross-sections have been compared with the theoretical model code PACE-2, which takes into account only the complete fusion process. The analysis indicates the presence of contributions from incomplete fusion processes in some α-emission channels following the break-up of the projectile {sup 20}Ne in the nuclear field of the target nucleus {sup 165}Ho.

  14. Possibilities of production of neutron-deficient isotopes of U, Np, Pu, Am, Cm, and Cf in complete fusion reactions

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.; Scheid, W.

    2008-10-15

    Within the dinuclear system model we analyze the production of yet unknown neutron-deficient isotopes of U, Np, Pu, Am, Cm, and Cf in various complete fusion reactions. Different deexcitation channels of the excited compound nucleus are treated. The results are obtained without special adjustment to the selected evaporation channel. The fusion probability is an important ingredient of the excitation function. The results are in good agreement with the available experimental data. The alpha decay half-life times in the neutron-deficient actinides are discussed.

  15. Rasiowa completion versus Keisler saturation: Towards a pragmatics of infinite fusion

    SciTech Connect

    Tomasik, J.A.

    1996-12-31

    The goal of this survey note is to make a step towards a semiotical approach to the control of Sensor Data Fusion systems. We try to adapt infinitistic methods of Rasiowa and Keisler as prototypes of a many-one pragmatics for the control of SDF in order to provide a faithful system - semantical or/and syntactical - adequate for simultaneous interpretation of signals received through several sensors. Intuitively, it is clear that the amount of the information captured during the fusion process depends strongly on the fusion itself. Nevertheless we can find (c.f. works of Kokar`s group) the following implicit heuristic in semiotical investigations on Sensory Data Fusion Z`s accepted.

  16. Atlanto-axial approach for cervical myelography in a Thoroughbred horse with complete fusion of the atlanto-occipital bones.

    PubMed

    Aleman, Monica; Dimock, Abigail N; Wisner, Erik R; Prutton, Jamie W; Madigan, John E

    2014-11-01

    A 2-year-old Thoroughbred gelding with clinical signs localized to the first 6 spinal cord segments (C1 to C6) had complete fusion of the atlanto-occipital bones which precluded performing a routine myelogram. An ultrasound-assisted myelogram at the intervertebral space between the atlas and axis was successfully done and identified a marked extradural compressive myelopathy at the level of the atlas and axis, and axis and third cervical vertebrae. PMID:25392550

  17. Complete and Incomplete Fusion Competition in 11B-INDUCED Fission Reactions on 197Au at the Intermediate Energy

    NASA Astrophysics Data System (ADS)

    Demekhina, N. A.; Karapetyan, G. S.; Balabekyan, A. R.

    2015-06-01

    Above Coulomb barrier cross sections of fission fragment production were measured in reactions of 11B with 197Au target. Induced-activity method was used for measurement the fission decay channel of the composite nuclei. Systematic of the fission fragment charge and mass distributions was used for fission cross section calculation. Fission fraction of the composite nuclei decay was compared with PACE-4 mode calculations. Estimated suppression for fission fraction followed the complete fusion have been obtained 35%.

  18. Atlanto-axial approach for cervical myelography in a Thoroughbred horse with complete fusion of the atlanto-occipital bones

    PubMed Central

    Aleman, Monica; Dimock, Abigail N.; Wisner, Erik R.; Prutton, Jamie W.; Madigan, John E.

    2014-01-01

    A 2-year-old Thoroughbred gelding with clinical signs localized to the first 6 spinal cord segments (C1 to C6) had complete fusion of the atlanto-occipital bones which precluded performing a routine myelogram. An ultrasound-assisted myelogram at the intervertebral space between the atlas and axis was successfully done and identified a marked extradural compressive myelopathy at the level of the atlas and axis, and axis and third cervical vertebrae. PMID:25392550

  19. Quasifission mass distributions in the synthesis of 274Hs with 26Mg and 36S projectiles

    NASA Astrophysics Data System (ADS)

    Budaca, R.; Sandulescu, A.; Mirea, M.

    2015-07-01

    The potential energy landscape for the 274Hs synthesis is evaluated in the framework of the macroscopic-microscopic model. The fragmentation potential calculated in a configuration space characterized by five degrees of freedom associated to elongation, mass asymmetry, necking, and left/right deformations reveals the existence of several minima and some pronounced valleys. The valleys correspond mainly to the 132Sn and 208Pb quasifission channels, but also for some paths in the formation of the compound nuclear system. In this context, two different paths are obtained for the 26Mg and 36S entrance channels. The 36S path leads to the formation of an isomeric minimum that decays by fission. The 26Mg path evidences a larger probability for the formation of the compound nucleus. Therefore, the two distributions obtained for the associated quasifission processes are very different.

  20. Suppression of complete fusion due to breakup in the reactions {sup 10,11}B+{sup 209}Bi

    SciTech Connect

    Gasques, L. R.; Hinde, D. J.; Dasgupta, M.; Mukherjee, A.; Thomas, R. G.

    2009-03-15

    Above-barrier cross sections of fission and {alpha}-active heavy reaction products were measured for the reactions of {sup 10,11}B with {sup 209}Bi. Systematic analysis showed that the fission originates almost exclusively from complete fusion (CF). Existing measurements of above-barrier fusion products for the {sup 30}Si+{sup 186}W reaction, assumed to proceed exclusively through CF, were extrapolated to the current systems using statistical model calculations. This extrapolation showed that the heavy reaction products from the {sup 10,11}B+{sup 209}Bi reactions include substantial components from incomplete fusion as well as from CF. Compared with fusion calculations without breakup, the CF cross sections are suppressed by 15% for {sup 10}B and 7% for {sup 11}B. A consistent and systematic variation of the suppression of CF for reactions of the weakly bound nuclei {sup 6,7}Li, {sup 9}Be, and {sup 10,11}B on targets of {sup 208}Pb and {sup 209}Bi is found as a function of the breakup threshold energy.

  1. Complete Fusion of FLUORINE-19 with ALUMINUM-27 and SILICON-28,30.

    NASA Astrophysics Data System (ADS)

    Chiou, Mei-Shiang Rosa

    Total fusion cross sections for the system ('19)F + ('27)Al and ('19)F + ('28,30)Si have been measured over the laboratory bombarding energy range 34 MeV-75 MeV by detecting the evaporation residues in a gas ionization (DELTA)E-E telescope. All three fusion excitation functions feature rather smooth energy-dependences, and the maximum fusion cross-sections reach 1200-1250 mb. Several commonly used macroscopic models have been applied to parametrize the cross sections and barrier parameters have been deduced. In the barrier penetration region the cross sections for ('19)F + ('28)Si is always sufficiently smaller than that for ('19)F + ('30)Si that the reduced barrier radius in a Glas -Mosel parameterization is significantly smaller for the former system than for the latter. Three entrance channels are now available for the fused system ('46)Ti: critical angular momentum data from the ('16)O + ('30)Si entrance channel approach the statistical Yrast line at much lower fused-system excitation energy than do the data from the entrance channels ('18)O + ('28)Si and ('19)F + ('27)Al.

  2. Complete and incomplete fusion in the reaction {sup 35}Cl+{sup 12}C at the energy range 70{endash}154 MeV

    SciTech Connect

    Pirrone, S.; Aiello, S.; Arena, N.; Cavallaro, S.; Femino, S.; Lanzalone, G.; Politi, G.; Porto, F.; Romano, S.; Sambataro, S.

    1997-05-01

    Velocity spectra of evaporation residues produced in the {sup 35}Cl+{sup 12}C reaction have been measured at bombarding energies of 125, 140, and 154 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate complete fusion and incomplete fusion components. The results show the presence of small contributions of incomplete fusion components which appear to be due to a cluster transfer reaction mechanism. Angular distributions and total and complete fusion evaporation residue cross sections were extracted at 70, 90, 110, 125, 140, and 154 MeV. The complete fusion cross sections and the deduced critical angular momenta are compared with other experimental data and the predictions of existing models. {copyright} {ital 1997} {ital The American Physical Society}

  3. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1990-10-01

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

  4. Population of ground-state rotational bands of superheavy nuclei produced in complete fusion reactions

    NASA Astrophysics Data System (ADS)

    Zubov, A. S.; Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.

    2011-10-01

    Using the statistical and quantum diffusion approaches, we study the population of ground-state rotational bands of superheavy nuclei produced in the fusion-evaporation reactions 208Pb(48Ca,2n)254No, 206Pb(48Ca,2n)252No, and 204Hg(48Ca,2n)250Fm. By describing the relative intensities of E2 transitions between the rotational states, the entry spin distributions of residual nuclei, and the excitation functions for these reactions, the dependence of fission barriers of shell-stabilized nuclei on angular momentum is investigated.

  5. Complete and incomplete fusion in the {sup 32}S+{sup 12}C reaction at E({sup 32}S)=20 MeV/A

    SciTech Connect

    Aiello, S.; Pirrone, S.; Politi, G.; Arena, N.; Cavallaro, Seb.; Sambataro, S.; Geraci, E.; Porto, F.; Lanzalone, G.

    1999-11-16

    Velocity distribution of mass identified evaporation residues produced in the {sup 32}S+{sup 12}C reaction at E({sup 32}S)=20 MeV/A have been measured using time-of-flight techniques. These distributions were used to separate the complete and incomplete fusion components. The complete fusion cross section and the deduced critical angular momenta are compared with other experimental data and the predictions of existing models.

  6. Complete and Incomplete fusion in the {sup 32}S+{sup 12}C reaction at E({sup 32}S)=20 MeV/A

    SciTech Connect

    S. Aiello; N. Arena; S. Cavallaro; E. Geraci; G. Lanzalone; S. Pirrone; G. Politi; F. Porto; S. Sambataro

    1999-12-31

    Velocity distribution of mass identified evaporation residues produced in the {sup 32}S+{sup 12}C reaction at E({sup 32}S)=20 MeV/A have been measured using time-of-flight techniques. These distributions were used to separate the complete and incomplete fusion components. The complete fusion cross section and the deduced critical angular momenta are compared with other experimental data and the predictions of existing models.

  7. Measurement of the complete fusion cross section of /sup 12/C+/sup 159/Tb, /sup 12/C+/sup 165/Ho

    SciTech Connect

    Wang Sufang; Cai Wei; Zheng Jiwen

    1989-07-01

    Complete fusion cross sections have been measured for /sup 12/C+/sup 159/Tb and /sup 12/C+/sup 165/Ho reactions by measuring /ital K/--/ital X/ rays of evaporation residues with a Si (Li) spectrometer. The half-lives of evaporation residues and their yield distributions as a function of incident energy have also been obtained. The experimental values for complete fusion cross sections were compared with the theoretical ones.

  8. Exploring quasifission characteristics for +232Th34S forming 266Sg

    NASA Astrophysics Data System (ADS)

    Prasad, E.; Wakhle, A.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Evers, M.; Luong, D. H.; Mohanto, G.; Simenel, C.; Vo-Phuoc, K.

    2016-02-01

    Background: Fission fragments from heavy ion collisions with actinide nuclei show mass-asymmetric and mass-symmetric components. The relative probabilities of these two components vary rapidly with beam energy with respect to the capture barrier, indicating a strong dependence on the alignment of the deformed nucleus with the partner in the collisions. Purpose: To study the characteristics of the mass-asymmetric quasifission component by reproducing the experimental mass-angle distributions to investigate mass evolution and sticking times. Methods: Fission fragment mass-angle distributions were measured for the +232Th34S reaction. Simulations to match the measurements were made by using a classical phenomenological approach. Mass ratio distributions and angular distributions of the mass-asymmetric quasifission component were simultaneously fit to constrain the free parameters used in the simulation. Results: The mass-asymmetric quasifission component—predominantly originating from tip (axial) collisions with the prolate deformed 232Th —is found to be peaked near A =200 at all energies and center-of-mass angles. A Monte Carlo model using the standard mass equilibration time constant of 5.2 ×10-21 s predicts more symmetric mass splits. Three different hypotheses assuming (i) a mass halt at A =200 , (ii) a slower mass equilibration time, or (iii) a Fermi-type mass drift function reproduced the main experimental features. Conclusions: In tip collisions for the +232Th34S reaction, mass-asymmetric fission with A ˜200 is the dominant outcome. The average sticking time is found to be ˜7 ×10-21 s, independent of the scenario used for mass evolution.

  9. Fusion and fission of heavy and superheavy nuclei (experiment)

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Vardaci, E.; Itkis, I. M.; Knyazheva, G. N.; Kozulin, E. M.

    2015-12-01

    The scope of this review is to summarize the main advancements in the search of signatures of the compound nucleus fission and quasifission processes in heavy and superheavy systems. The understanding of fusion and fission in heavy and superheavy elements is needed for tracing paths aimed at reaching the island of stability situated near Z = 114- 122 and N = 184. With increasing charge of the interacting nuclei other processes, like quasifission, emerge and compete against fusion. Hence also their study must be pursued. After a brief look at the experimental techniques, the behavior of several observables is extracted from the most recent data to aid in the disentanglement of the various competing processes which hinder the production of superheavy elements.

  10. The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine

    SciTech Connect

    Farmer, J C; Diaz de la Rubia, T; Moses, E

    2008-12-23

    The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission blanket in a fusion

  11. Fusion Hindrance and the Role of Shell Effects in the Superheavy Mass Region

    SciTech Connect

    Aritomo, Y.

    2006-08-14

    We present the first attempt of the systematical investigation about the effects of shell correction energy for dynamical processes, which include fusion, fusion-fission and quasi-fission processes. In the superheavy mass region, for the fusion process, the shell correction energy plays a very important role and enhances the fusion probability, when the colliding partner has strong shell structure. By analyzing the trajectory in the three-dimensional coordinate space with a Langevin equation, we reveal the mechanism of the enhancement of the fusion probability caused by shell effects.

  12. Effects of extracellular calcium and surgical techniques on restoration of axonal continuity by polyethylene glycol fusion following complete cut or crush severance of rat sciatic nerves.

    PubMed

    Ghergherehchi, Cameron L; Bittner, George D; Hastings, Robert Louis; Mikesh, Michelle; Riley, D Colton; Trevino, Richard C; Schallert, Tim; Thayer, Wesley P; Sunkesula, Solomon Raju Bhupanapadu; Ha, Tu-Anh N; Munoz, Nicolas; Pyarali, Monika; Bansal, Aakarshita; Poon, Andrew D; Mazal, Alexander T; Smith, Tyler A; Wong, Nicole S; Dunne, Patrick J

    2016-03-01

    Complete crush or cut severance of sciatic nerve axons in rats and other mammals produces immediate loss of axonal continuity. Loss of locomotor functions subserved by those axons is restored only after months, if ever, by outgrowths regenerating at ∼1 mm/day from the proximal stumps of severed axonal segments. The distal stump of a severed axon typically begins to degenerate in 1-3 days. We recently developed a polyethylene glycol (PEG) fusion technology, consisting of sequential exposure of severed axonal ends to hypotonic Ca(2+) -free saline, methylene blue, PEG in distilled water, and finally Ca(2+) -containing isotonic saline. This study examines factors that affect the PEG fusion restoration of axonal continuity within minutes, as measured by conduction of action potentials and diffusion of an intracellular fluorescent dye across the lesion site of rat sciatic nerves completely cut or crush severed in the midthigh. Also examined are factors that affect the longer-term PEG fusion restoration of lost behavioral functions within days to weeks, as measured by the sciatic functional index. We report that exposure of cut-severed axonal ends to Ca(2+) -containing saline prior to PEG fusion and stretch/tension of proximal or distal axonal segments of cut-severed axons decrease PEG fusion success. Conversely, trimming cut-severed ends in Ca(2+) -free saline just prior to PEG fusion increases PEG fusion success. PEG fusion prevents or retards the Wallerian degeneration of cut-severed axons, as assessed by measures of axon diameter and G ratio. PEG fusion may produce a paradigm shift in the treatment of peripheral nerve injuries. © 2016 Wiley Periodicals, Inc. PMID:26728662

  13. Stability of superheavy nuclei produced in actinide-based complete fusion reactions: Evidence for the next magic proton number at Z{>=}120

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Sargsyan, V. V.

    2009-05-15

    Using the experimental evaporation residue cross sections in the {sup 48}Ca-induced complete fusion reactions and the complete fusion cross sections calculated within the dinuclear system model, the survival probabilities of superheavy nuclei with charge numbers Z=112-116 and 118 in the xn-evaporation channels are extracted. The effects of angular momentum and deformations of colliding nuclei are taken into account. The obtained dependence of the survival probability on Z indicates the next doubly magic nucleus beyond {sup 208}Pb at Z{>=}120.

  14. Complete and incomplete fusion reactions in the {sup 16}O+{sup 169}Tm system: Excitation functions and recoil range distributions

    SciTech Connect

    Sharma, Manoj Kumar; Unnati,; Sharma, B.K.; Singh, B.P.; Prasad, R.; Bhardwaj, H.D.; Kumar, Rakesh; Golda, K.S.

    2004-10-01

    With the view to study complete and incomplete fusion in heavy ion induced reactions, experiments have been carried out for measuring excitation functions for several reactions in the system {sup 16}O+{sup 169}Tm at energies near the Coulomb barrier to well above it, using an activation technique. The measured excitation functions have been compared with those calculated theoretically using three different computer codes viz., ALICE-91, CASCADE and PACE2. The enhancement of experimentally measured cross sections for alpha emission channels over their theoretical prediction has been attributed to the fact that these residues are formed not only by complete fusion but also through incomplete fusion. In order to separate out the relative contributions of complete and incomplete fusion, the recoil range distributions of eight residues produced in the interaction of {sup 16}O with {sup 169}Tm at {approx_equal}87 MeV have been measured. The recoil range distributions indicate significant contributions from incomplete fusion at {approx_equal}87 MeV for some of the channels.

  15. Cross section systematics for the lightest Bi and Po nuclei produced in complete fusion reactions with heavy ions

    SciTech Connect

    Andreyev, A.N.; Ackermann, D.; Muenzenberg, G.; Antalic, S.; Saro, S.; Streicher, B.; Darby, I.G.; Page, R.D.; Wiseman, D.R.; Franchoo, S.; Hessberger, F.P.; Kuusiniemi, P.; Lommel, B.; Kindler, B.; Mann, R.; Sulignano, B.; Hofmann, S.; Huyse, M.; Vel, K. van de; Duppen, P. van

    2005-07-01

    The production of the very neutron-deficient nuclides {sup 184-192}Bi and {sup 186-192}Po in the vicinity of the neutron midshell at N = 104 has been studied by using heavy-ion-induced complete fusion reactions in a series of experiments at the velocity filter SHIP. The cross sections for the xn and pxn evaporation channels of the {sup 46}Ti+{sup 144}Sm{yields}{sup 190}Po*,{sup 98}Mo+{sup 92}Mo{yields}{sup 190}Po*,{sup 50,52}Cr+{sup 142}Nd{yields}{sup 192,194}Po*, and {sup 94,95}Mo+{sup 93}Nb{yields}{sup 187,188}Bi* reactions were measured. The results obtained, together with the previously known cross section data for the heavier Bi and Po nuclides, are compared with the results of statistical model calculations carried out with the HIVAP code. It is shown that a satisfactory description of the experimental data requires a significant (up to 35%) reduction of the theoretical fission barriers. The optimal reactions for production of the lightest Bi and Po isotopes are discussed.

  16. Strong evidence for quasifission in asymmetric reactions forming {sup 202}Po

    SciTech Connect

    Rafiei, R.; Thomas, R. G.; Hinde, D. J.; Dasgupta, M.; Morton, C. R.; Gasques, L. R.; Brown, M. L.; Rodriguez, M. D.

    2008-02-15

    Fission fragment mass-angle correlations and mass ratio distributions have been measured for the reactions {sup 16}O+{sup 186}Os, {sup 24}Mg+{sup 178}Hf, {sup 34}S+{sup 168}Er, and {sup 48}Ti+{sup 154}Sm, forming the {sup 202}Po composite nucleus, at near barrier energies. Systematic analysis based on the expected dependence of the variance of the mass distribution on the angular momentum and temperature of the compound nucleus indicate that the two lighter systems evolve through true compound nucleus fission. Evidence of quasifission was observed for the two most mass-symmetric reactions, through strong mass-angle correlations for the {sup 48}Ti+{sup 154}Sm reaction and a broadened mass ratio distribution for the {sup 34}S+{sup 168}Er reaction. Furthermore, the increase in mass width at near barrier energies shows the influence of the alignment of statically deformed target nuclei.

  17. Complete and incomplete fusion and emission of preequilibrium nucleons in the interaction of [sup 12]C with [sup 197]Au below 10 MeV/nucleon

    SciTech Connect

    Vergani, P.; Gadioli, E.; Vaciago, E.; Fabrici, E.; Gadioli Erba, E.; Galmarini, M. ); Ciavola, G.; Marchetta, C. )

    1993-10-01

    The excitation functions for production of nineteen isotopes of At, Po, Bi, Pb, and Tl in the interaction of [sup 12]C with [sup 197]Au between 57 and 97 MeV incident energy have been measured with the activation technique. The analysis of these data allows one to estimate the cross sections for complete fusion of [sup 12]C and incomplete fusion of [sup 8]Be and [alpha] fragments with gold, and shows the presence of preequilibrium emissions at incident energies only slightly higher than the Coulomb barrier acting between [sup 12]C and [sup 197]Au.

  18. Effect of breakup and transfer on complete and incomplete fusion in 6Li+209Bi reaction in multi-body classical molecular dynamics calculation

    NASA Astrophysics Data System (ADS)

    Morker, Mitul R.; Godre, Subodh S.

    2016-05-01

    The effect of breakup and transfer in 6Li+209Bi reaction is studied in a multi-body classical molecular dynamics approach in which the weakly-bound projectile 6Li is constructed as a 2-body cluster of 4He and 2H in a configuration corresponding to the observed breakup energy. This 3-body system with their individual nucleon configuration in their ground state is dynamically evolved with given initial conditions using Classical Rigid Body Dynamics (CRBD) approach up to distances close to the barrier when the rigid-body constraint on the target, inter-fragment distance, and 2H itself are relaxed, allowing for possible breakup of 2H which may result in incomplete fusion following the transfer of the n or p. Relative probabilities of the possible events such as scattering with and without breakup, DCF, SCF, ICF(x) where x may be 4He, 2H, 4He+n, 4He+p, n, p are calculated. Comparison of the calculated event-probabilities, complete, and incomplete fusion cross sections with the calculation in which 2H is kept rigid demonstrates the effect of the transfer reactions on complete and incomplete fusion in the 4-body reaction. Events ICF(4He+n) corresponding to nstripping followed by breakup of the resultant 5Li to 4He+p are found to contribute significantly in the fusion process in agreement with a recent experimental observation of direct reaction processes in breakup of weakly-bound projectiles.

  19. Constitutively active IRF7/IRF3 fusion protein completely protects swine against Foot-and-Mouth Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease (FMD) remains one of the most devastating livestock diseases around the world. Several serotype specific vaccine formulations exist but require about 5-7 days to induce protective immunity. Our previous studies have shown that a constitutively active fusion protein of porcine ...

  20. Spectroscopy of A˜190 Ir-Pt-Au Nuclei Near Stability from Complete and Incomplete Fusion Reaction

    NASA Astrophysics Data System (ADS)

    Fang, Y. D.; Zhang, Y. H.; Zhou, X. H.; Liu, M. L.; Wang, J. G.; Guo, Y. X.; Lei, X. G.; Hua, W.; Ma, F.; Wang, S. C.; Gao, B. S.; Li, S. C.; Wu, X. G.; He, C. Y.; Zheng, Y.; Wang, Z. M.; Shi, Y.; Xu, F. R.

    2013-11-01

    High-spin states of 194, 195Au, 195Pt and 193Ir have been studied using an in-beam γ-ray spectroscopic technique following the reaction of 7Li on an 192Os target at 44 MeV. The emitted γ rays were observed using an array of 14 Compton-suppressed HPGe detectors. Several bands in these nuclei have been identified and extended up to high-spin states. The α and t emission channels leading to 193Ir and 195Pt, respectively, are strongly enhanced which may be explained by incomplete fusion reaction; the t and α fragments from the break-up of weakly bound 7Li nucleus fusion with 192Os target.

  1. How the projectile neutron number influences the evaporation cross section in complete fusion reactions with heavy ions

    SciTech Connect

    Wang Chengbin; Zhang Jinjuan; Ren, Z. Z.; Shen, C. W.

    2010-11-15

    The influence of the projectile neutron number on the evaporation residue cross sections for the reactions {sup 208}Pb({sup 52,54}Cr,n,2n){sup 258-261}Sg and {sup 208}Pb({sup 48,50}Ti,n,2n){sup 254-257}Rf has been studied within the framework of a fusion-fission statistical model. The results obtained with the kewpie2 code are compared with recent experimental data. The excitation functions represent the experimental results well both in the maximum value and the lactation of the peak. The calculations show that the projectile neutron number greatly influences both the capture cross section and the fusion probability.

  2. Complete and Incomplete Fusion of {sup 6}He and {sup 6}Li Projectiles with Medium Mass Targets at Energy {approx}10 AMeV

    SciTech Connect

    Krupko, S. A.; Daniel, A. V.; Fomichev, A. S.; Golovkov, M. S.; Gorshkov, V. A.; Oganessian, Yu. Ts.; Popeko, G. S.; Sidorchuk, S. I.; Ter-Akopian, G. M.; Slepnev, R. S.; Chudoba, V.; Standylo, L.; Chepigin, V. I.; Katrasev, D. E.; Malyshev, O. N.; Svirikhin, A. I.; Yeremin, A. V.; Wolski, R.; Briancon, Ch.; Hauschild, K.

    2009-03-04

    Complete fusion (CF) and incomplete fusion (ICF) reactions were studied with the beams of loosely bound {sup 6}He and {sup 6}Li bombarding {sup 166}Er and {sup 165}Ho targets. Experiments were carried out to test an approach exploiting the measured intensities of {gamma} rays emitted at the transitions between the yrast-band levels of reaction products formed after the termination of neutron evaporation. Partial waves feeding the CF [{sup 165}Ho({sup 6}Li,5n){sup 166}Yb, {sup 166}Er({sup 6}He,6n){sup 166}Yb] and ICF [{sup 165}Ho({sup 6}Li,{alpha}3n){sup 164}Er, and {sup 166}Er({sup 6}He,{alpha}4n){sup 164}Er] reaction channels were revealed from the obtained {gamma}-ray data.

  3. Effective temperatures in complete fusion for the system {sup 58}Ni + {sup 58}Ni at 500 MeV bombarding energy

    SciTech Connect

    D`Onofrio, A.; Campajola, L.; Inglima, G.; Roca, V.

    1996-12-01

    Triple coincidences between complex fragments with Z > 3, light charged particles and {gamma} transitions have been measured for the system {sup 58}Ni+{sup 58}Ni at 500 MeV incident energy. To this end the HILI detector and a 19 pack BaF{sub 2} cluster made of 19 crystals of TAPS geometry have been used. Effective temperatures have been obtained from the ratios of the bound excited level cross sections to the ground states ones for C. N and 0 evaporated after complete fusion of {sup 58}Ni +{sup 58}Ni at 500 MeV incident energy. The dependence of the effective temperature on the charged light particle multiplicity has been investigated.

  4. Angular momentum effects and barrier modification in sub-barrier fusion reactions using the proximity potential in the Wong formula

    SciTech Connect

    Kumar, Raj; Bansal, Manie; Arun, Sham K.; Gupta, Raj K.

    2009-09-15

    Using the capture cross-section data from {sup 48}Ca+{sup 238}U, {sup 48}Ca+{sup 244}Pu, and {sup 48}Ca+{sup 248}Cm reactions in the superheavy mass region, and 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 known for fusion hindrance phenomenon in coupled-channels calculations, the Wong formula is assessed for its angular momentum and barrier-modification effects at sub-barrier energies. The simple, l=0 barrier-based Wong formula is shown to ignore the modifications of the barrier due to its inbuilt l dependence via l summation, which is found to be adequate enough to explain the capture cross sections for all the three above-mentioned {sup 48}Ca-based reactions forming superheavy systems. For the capture (equivalently, quasifission) reactions, the complete l-summed Wong formula is shown to be the same as the dynamical cluster-decay model expression, of one of us (R.K.G.) and collaborators, with the condition of fragment preformation probability P{sub 0}{sup l}=1 for all the angular momentum l values. In the case of fusion-evaporation cross sections, however, a further modification of barriers is required for below-barrier energies, affected in terms of either the barrier 'lowering' or barrier 'narrowing' via the curvature constant. Calculations are made for use of nuclear proximity potential, with effects of multipole deformations included up to hexadecapole, and orientation degrees of freedom integrated for both the coplanar and noncoplanar configurations.

  5. Calculation of the energy dependence of the fusion cross section and total cross sections for peripheral reactions on the basis of an analysis of data on elastic heavy-ion scattering: Strongly bound ions

    SciTech Connect

    Pozdnyakov, Yu. A.

    2007-09-15

    A method is proposed for calculating the energy dependence of the fusion cross section (in general, the sum of the cross sections for complete and incomplete fusion, quasifission, and reactions of deep-inelastic scattering) {sigma}{sub F}(E) and the total cross section for peripheral (or quasielastic) reactions, {sigma}{sub D}(E). The method is based on an analysis of a limited set of angular distributions for the elastic scattering in a given pair of nuclei. The predictive power of the method is illustrated by considering the {sup 16}O + {sup 208}Pb, {sup 16}O + {sup 40}Ca, and {sup 16}O + {sup 28}Si systems. For each of these systems, the calculations were performed at energies in the range extending from subbarrier values to those exceeding the barrier height substantially. The results of the calculations are found to be in good agreement with relevant experimental data, whereby the reliability of the method is confirmed. By virtue of this, it is proposed to employ the method to study the energy dependences {sigma}{sub F}(E) and {sigma}{sub D}(E) in collisions involving unstable nuclei, for which it is difficult to determine experimentally the above dependences because of a low intensity of secondary beams.

  6. Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in the 238U+64Ni reaction

    NASA Astrophysics Data System (ADS)

    Sekizawa, Kazuyuki; Yabana, Kazuhiro

    2016-05-01

    Background: Multinucleon transfer (MNT) and quasifission (QF) processes are dominant processes in low-energy collisions of two heavy nuclei. They are expected to be useful to produce neutron-rich unstable nuclei. Nuclear dynamics leading to these processes depends sensitively on nuclear properties such as deformation and shell structure. Purpose: We elucidate reaction mechanisms of MNT and QF processes involving heavy deformed nuclei, making detailed comparisons between microscopic time-dependent Hartree-Fock (TDHF) calculations and measurements for the 238U+64Ni reaction. Methods: Three-dimensional Skyrme-TDHF calculations are performed. Particle-number projection method is used to evaluate MNT cross sections from the TDHF wave function after collision. Results: Fragment masses, total kinetic energy (TKE), scattering angle, contact time, and MNT cross sections are investigated for the 238U+64Ni reaction. They show reasonable agreements with measurements. At small impact parameters, collision dynamics depends sensitively on the orientation of deformed 238U. In tip (side) collisions, we find a larger (smaller) TKE and a shorter (longer) contact time. In tip collisions, we find a strong influence of quantum shells around 208Pb. Conclusions: It is confirmed that the TDHF calculations reasonably describe both MNT and QF processes in the 238U64Ni reaction. Analyses of this system indicate the significance of the nuclear structure effects such as deformation and quantum shells in nuclear reaction dynamics at low energies.

  7. Fission-fragment angular distributions and excitation functions in fission following complete fusion and targetlike-fragment fission reactions of 19F+232Th at near- and sub-barrier energies

    NASA Astrophysics Data System (ADS)

    Majumdar, N.; Bhattacharya, P.; Biswas, D. C.; Choudhury, R. K.; Nadkarni, D. M.; Saxena, A.

    1995-06-01

    The fragment angular distributions and excitation functions of the fission following complete fusion (FFCF) have been measured after separating them from targetlike-fragment fission (TLFF) for the 19F+232Th system in the bombarding energy range of 84.5 to 106.5 MeV. The fraction of the targetlike-fragment fission was observed to increase with decreasing bombarding energy below the Coulomb barrier. The excitation function for fission following complete fusion reaction agrees well with coupled channel calculations. However, the values derived from the fragment anisotropy data of the FFCF events are found to be much larger than those calculated using the coupled channel transmission coefficient values. The discrepancy between the experimental and calculated values increases as the bombarding energy is decreased below the barrier.

  8. A dumbbell model with five parameters describing nuclear fusion or fission

    NASA Astrophysics Data System (ADS)

    Sun, Qian; Shangguan, Dan-Hua; Bao, Jing-Dong

    2013-01-01

    We propose a five-parameter dumbbell model to describe the fusion and fission processes of massive nuclei, where the collective variables are: the distance ρ between the center-of-mass of two fusing nuclei, the neck parameter υ, asymmetry D, two deformation variables β1 and β2. The present model has macroscopic qualitative expression of polarization and nuclear collision of head to head, sphere to sphere, waist to waist and so on. The conception of the “projectile eating target" based on open mouth and swallow is proposed to describe the nuclear fusion process, and our understanding of the probability of fusion and quasi-fission is in agreement with some previous work. The calculated fission barriers of a lot of compound nuclei are compared with the experimental data.

  9. Spinal fusion

    MedlinePlus

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

  10. Observation of the 3n evaporation channel in the complete hot-fusion reaction 26Mg + 248Cm leading to the new superheavy nuclide 271Hs.

    PubMed

    Dvorak, J; Brüchle, W; Chelnokov, M; Düllmann, Ch E; Dvorakova, Z; Eberhardt, K; Jäger, E; Krücken, R; Kuznetsov, A; Nagame, Y; Nebel, F; Nishio, K; Perego, R; Qin, Z; Schädel, M; Schausten, B; Schimpf, E; Schuber, R; Semchenkov, A; Thörle, P; Türler, A; Wegrzecki, M; Wierczinski, B; Yakushev, A; Yeremin, A

    2008-04-01

    The analysis of a large body of heavy ion fusion reaction data with medium-heavy projectiles (6 < or = Z < or = 18) and actinide targets suggests a disappearance of the 3n exit channel with increasing atomic number of the projectile. Here, we report a measurement of the excitation function of the reaction (248)Cm ((26)Mg,xn)(274-x)Hs and the observation of the new nuclide (271)Hs produced in the 3n evaporation channel at a beam energy well below the Bass fusion barrier with a cross section comparable to the maxima of the 4n and 5n channels. This indicates the possible discovery of new neutron-rich transactinide nuclei using relatively light heavy ion beams of the most neutron-rich stable isotopes and actinide targets. PMID:18517941

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

    SciTech Connect

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

    2010-04-30

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

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

    SciTech Connect

    Zagrebaev, Valery; Greiner, Walter

    2006-08-14

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

  13. Capture and Fusion-Fission Processes in Heavy Ion Induced Reactions

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Beghini, S.; Behera, B. R.; Bogatchev, A. A.; Bouchat, V.; Corradi, L.; Dorvaux, O.; Fioretto, E.; Gadea, A.; Hanappe, F.; Itkis, I. M.; Jandel, M.; Kliman, J.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Latina, A.; Lyapin, V. G.; Materna, T.; Montagnoli, G.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Rowley, N.; Rubchenya, V. A.; Rusanov, A. Ya.; Sagaidak, R. N.; Scarlassara, F.; Schmitt, C.; Stefanini, A. M.; Stuttge, L.; Szilner, S.; Trotta, M.; Trzaska, W. H.; Voskresenski, V. M.

    2005-11-01

    Results of the experiments aimed at the study of fission and quasi-fission processes in the reactions 12C+204Pb, 48Ca+144,154Sm, 168Er, 208Pb, 238U, 244Pu, 248Cm; 58Fe+208Pb, 244Pu, 248Cm, and 64Ni+186W, 242Pu are presented. The choice of the above-mentioned reactions was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 at Dubna using the same reactions. The 58Fe and 64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) and the Accelerator of the Laboratory of University of Jyvaskyla (JYFL, Finland) using the time-of-flight spectrometer of fission fragments CORSET and the neutron multi-detector DEMON. The role of shell effects and the influence of the entrance channel asymmetry and the deformations of colliding nucleus on the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed.

  14. Persistent Suppression of Type 1 Diabetes by a Multicomponent Vaccine Containing a Cholera Toxin B Subunit-Autoantigen Fusion Protein and Complete Freund's Adjuvant

    PubMed Central

    Dénes, Béla; Fodor, István; Langridge, William H. R.

    2013-01-01

    Data presented here demonstrate multifunctional vaccination strategies that harness vaccinia virus mediated delivery of a gene encoding an immunoenhanced diabetes autoantigen in combination with complete Freund's adjuvant (CFA) that can maintain safe and durable immunologic homeostasis in NOD mice. Systemic coinoculation of prediabetic mice with recombinant vaccinia virus rVV-CTB::GAD and undiluted or 10-fold diluted CFA demonstrated a significant decrease in hyperglycemia and pancreatic islet inflammation in comparison with control animals during 17–61 and 17–105 weeks of age, respectively. Synergy in these beneficial effects was observed during 43–61 and 61–105 wks of age, respectively. Inflammatory cytokine and chemokine levels in GAD-stimulated splenocytes isolated from vaccinated mice were generally lower than those detected in unvaccinated mice. The overall health and humoral immune responses of the vaccinated animals remained normal throughout the duration of the experiments. PMID:24319466

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

    SciTech Connect

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

    2010-06-01

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

  16. Charged particle decay of hot and rotating 88Mo nuclei in fusion-evaporation reactions

    NASA Astrophysics Data System (ADS)

    Valdré, S.; Piantelli, S.; Casini, G.; Barlini, S.; Carboni, S.; Ciemała, M.; Kmiecik, M.; Maj, A.; Mazurek, K.; Cinausero, M.; Gramegna, F.; Kravchuk, V. L.; Morelli, L.; Marchi, T.; Baiocco, G.; Bardelli, L.; Bednarczyk, P.; Benzoni, G.; Bini, M.; Blasi, N.; Bracco, A.; Brambilla, S.; Bruno, M.; Camera, F.; Chbihi, A.; Corsi, A.; Crespi, F. C. L.; D'Agostino, M.; Degerlier, M.; Fabris, D.; Fornal, B.; Giaz, A.; Krzysiek, M.; Leoni, S.; Matejska-Minda, M.; Mazumdar, I.; MÈ©czyński, W.; Million, B.; Montanari, D.; Myalski, S.; Nicolini, R.; Olmi, A.; Pasquali, G.; Prete, G.; Roberts, O. J.; Styczeń, J.; Szpak, B.; Wasilewska, B.; Wieland, O.; Wieleczko, J. P.; ZiÈ©bliński, M.

    2016-03-01

    A study of fusion-evaporation and (partly) fusion-fission channels for the 88Mo compound nucleus, produced at different excitation energies in the reaction 48Ti+40Ca at 300, 450, and 600 MeV beam energies, is presented. Fusion-evaporation and fusion-fission cross sections have been extracted and compared with the existing systematics. Experimental data concerning light charged particles have been compared with the prediction of the statistical model in its implementation in the gemini++ code, well suited even for high spin systems, in order to tune the main model parameters in a mass region not abundantly covered by exclusive experimental data. Multiplicities for light charged particles emitted in fusion evaporation events are also presented. Some discrepancies with respect to the prediction of the statistical model have been found for forward emitted α particles; they may be due both to pre-equilibrium emission and to reaction channels (such as deep inelastic collisions or quasifission/quasifusion) different from the compound nucleus formation.

  17. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-04-20

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

  18. Fusion Implementation

    SciTech Connect

    J.A. Schmidt

    2002-02-20

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

  19. Fusion and Breakup of Weakly Bound Nuclei

    SciTech Connect

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

    2006-08-14

    We discuss the influence of the breakup process of weakly bound nuclei on the fusion cross section. The complete fusion for heavy targets is found to be suppressed due to the incomplete fusion following the breakup, whereas this effect is negligible for light targets. The total fusion cross sections for stable projectiles are not affected by the breakup process, whereas it is suppressed for halo projectiles. The non capture breakup is the dominant process at sub-barrier energies.

  20. Image fusion

    NASA Technical Reports Server (NTRS)

    Pavel, M.

    1993-01-01

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

  1. Incomplete fusion dynamics by spin distribution measurements

    SciTech Connect

    Singh, D.; Ali, R.; Ansari, M. Afzal; Singh, Pushpendra P.; Sharma, M. K.; Singh, B. P.; Babu, K. Surendra; Sinha, Rishi K.; Kumar, R.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

    2010-02-15

    Spin distributions for various evaporation residues populated via complete and incomplete fusion of {sup 16}O with {sup 124}Sn at 6.3 MeV/nucleon have been measured, using charged particles (Z=1,2)-{gamma} coincidence technique. Experimentally measured spin distributions of the residues produced as incomplete fusion products associated with 'fast'{alpha}- and 2{alpha}-emission channels observed in the 'forward cone' are found to be distinctly different from those of the residues produced as complete fusion products. Moreover, 'fast'{alpha}-particles that arise from larger angular momentum in the entrance channel are populated at relatively higher driving input angular momentum than those produced through complete fusion. The incomplete fusion residues are populated in a limited, higher-angular-momentum range, in contrast to the complete fusion products, which are populated over a broad spin range.

  2. OCULUS Sea Track Fusion Service

    NASA Astrophysics Data System (ADS)

    Panagiotou, Stylianos C.; Rizogiannis, Constantinos; Katsoulis, Stavros; Lampropoulos, Vassilis; Kanellopoulos, Sotirios; Thomopoulos, Stelios C. A.

    2015-06-01

    Oculus Sea is a complete solution regarding maritime surveillance and communications at Local as well as Central Command and Control level. It includes a robust and independent track fusion service whose main functions include: 1) Interaction with the User to suggest the fusion of two or more tracks, confirm Track ID and Vessel Metadata creation for the fused track, and suggest de-association of two tracks 2) Fusion of same vessel tracks arriving simultaneously from multiple radar sensors featuring track Association, track Fusion of associated tracks to produce a more accurate track, and Multiple tracking filters and fusion algorithms 3) Unique Track ID Generator for each fused track 4) Track Dissemination Service. Oculus Sea Track Fusion Service adopts a system architecture where each sensor is associated with a Kalman estimator/tracker that obtains an estimate of the state vector and its respective error covariance matrix. Finally, at the fusion center, association and track state estimation fusion are carried out. The expected benefits of this system include multi-sensor information fusion, enhanced spatial resolution, and improved target detection.

  3. Collescipoli - An unusual fusion crust glass. [chondrite

    NASA Technical Reports Server (NTRS)

    Nozette, S.

    1979-01-01

    An electron microprobe study was conducted on glass fragments taken from the fusion crust and an internal glass-lined vein in the H-5 chondrite Collescipoli. Microprobe analyses of the glasses revealed an unusual fusion crust composition, and analyses of glass from inside the meteorite showed compositions expected for a melt of an H-group chondrite. Studies of fusion crusts by previous workers, e.g., Krinov and Ramdohr, showed that fusion crusts contain large amounts of magnetite and other oxidized minerals. The Collescipoli fusion crusts do contain these minerals, but they also contain relatively large amounts of reduced metal, sulphide, and a sodium-rich glass. This study seems to indicate that Collescipoli preserved an early type of fusion crust. Oxidation was incomplete in the fusion crust melt that drained into a crack. From this study it is concluded that fusion crust formation does not invariably result in complete oxidation of metal and sulphide phases.

  4. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

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

  5. Observation of the 3n Evaporation Channel in the Complete Hot-Fusion Reaction {sup 26}Mg+{sup 248}Cm Leading to the New Superheavy Nuclide {sup 271}Hs

    SciTech Connect

    Dvorak, J.; Dvorakova, Z.; Kruecken, R.; Nebel, F.; Perego, R.; Schuber, R.; Tuerler, A.; Wierczinski, B.; Yakushev, A.; Bruechle, W.; Jaeger, E.; Schaedel, M.; Schausten, B.; Schimpf, E.; Chelnokov, M.; Kuznetsov, A.; Yeremin, A.; Duellmann, Ch. E.; Eberhardt, K.; Nagame, Y.

    2008-04-04

    The analysis of a large body of heavy ion fusion reaction data with medium-heavy projectiles (6{<=}Z{<=}18) and actinide targets suggests a disappearance of the 3n exit channel with increasing atomic number of the projectile. Here, we report a measurement of the excitation function of the reaction {sup 248}Cm({sup 26}Mg,xn){sup 274-x}Hs and the observation of the new nuclide {sup 271}Hs produced in the 3n evaporation channel at a beam energy well below the Bass fusion barrier with a cross section comparable to the maxima of the 4n and 5n channels. This indicates the possible discovery of new neutron-rich transactinide nuclei using relatively light heavy ion beams of the most neutron-rich stable isotopes and actinide targets.

  6. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

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

  7. Complete diphallia.

    PubMed

    Acimi, Smail

    2008-01-01

    A case of complete diphallia in a 4-month-old boy is reported. This is the second case to be published from this institution. The embryogenesis and associated anomalies of diphallia are discussed, together with a proposal for a classification based on anatomical, functional and therapeutic aspects of the malformation. PMID:19230173

  8. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

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

  9. Working with Fusion in Lesbian Couples.

    ERIC Educational Resources Information Center

    Roth, Nicki F.

    The phenomena of fusion within a lesbian relationship is described in a six-phased model. Fusion in relationships is defined as two incomplete people coming together in an attempt to make one more complete whole, the merging of two ego boundaries. The six phases discussed include ecstacy, getting married, the routine, depression/withdrawal,…

  10. Mass Producing Targets for Nuclear Fusion

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  11. National Ignition Facility for Inertial Confinement Fusion

    SciTech Connect

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

    1997-10-08

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

  12. Complete prewetting

    NASA Astrophysics Data System (ADS)

    Yatsyshin, P.; Parry, A. O.; Kalliadasis, S.

    2016-07-01

    We study continuous interfacial transitions, analagous to two-dimensional complete wetting, associated with the first-order prewetting line, which can occur on steps, patterned walls, grooves and wedges, and which are sensitive to both the range of the intermolecular forces and interfacial fluctuation effects. These transitions compete with wetting, filling and condensation producing very rich phase diagrams even for relatively simple prototypical geometries. Using microscopic classical density functional theory to model systems with realistic Lennard-Jones fluid–fluid and fluid–substrate intermolecular potentials, we compute mean-field fluid density profiles, adsorption isotherms and phase diagrams for a variety of confining geometries.

  13. Is Fusion Inhibited for Weakly Bound Nuclei?

    SciTech Connect

    Takahashi, J.; Munhoz, M.; Szanto, E.M.; Carlin, N.; Added, N.; Suaide, A.A.; de Moura, M.M.; Liguori Neto, R.; Szanto de Toledo, A.; Canto, L.F.

    1997-01-01

    Complete fusion of light radioactive nuclei is predicted to be hindered at near-barrier energies. This feature is investigated in the case of the least bound stable nuclei. Evaporation residues resulting from the {sup 6,7}Li+{sup 9}Be and {sup 6,7}Li+{sup 12}C fusion reactions have been measured in order to study common features in reactions involving light weakly bound nuclei. The experimental excitation functions revealed that the fusion cross section is significantly smaller than the total reaction cross section and also smaller than the fusion cross section expected from the available systematics. A clear correlation between the fusion probability and nucleon (cluster) separation energy has been established.The results suggest that the breakup process has a strong influence on the hindrance of the fusion cross section. {copyright} {ital 1996} {ital The American Physical Society}

  14. Complete Makeover

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released July 23, 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    We finish our look at Mars's dynamic atmosphere with an image of the surface that has been completely modified by the wind. Even the small ridges that remain have been ground down to a cliff-face with a 'tail' of eroded material. The crosshatching shows that the wind regime has remained mainly E/W to ENE/WSW.

    Image information: VIS instrument. Latitude 8.9, Longitude 221 East (139 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip

  15. Fusion bonding and alignment fixture

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2000-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all the components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  16. Method for vacuum fusion bonding

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2001-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  17. Fusion metrics for dynamic situation analysis

    NASA Astrophysics Data System (ADS)

    Blasch, Erik P.; Pribilski, Mike; Daughtery, Bryan; Roscoe, Brian; Gunsett, Josh

    2004-08-01

    To design information fusion systems, it is important to develop metrics as part of a test and evaluation strategy. In many cases, fusion systems are designed to (1) meet a specific set of user information needs (IN), (2) continuously validate information pedigree and updates, and (3) maintain this performance under changing conditions. A fusion system"s performance is evaluated in many ways. However, developing a consistent set of metrics is important for standardization. For example, many track and identification metrics have been proposed for fusion analysis. To evaluate a complete fusion system performance, level 4 sensor management and level 5 user refinement metrics need to be developed simultaneously to determine whether or not the fusion system is meeting information needs. To describe fusion performance, the fusion community needs to agree on a minimum set of metrics for user assessment and algorithm comparison. We suggest that such a minimum set should include feasible metrics of accuracy, confidence, throughput, timeliness, and cost. These metrics can be computed as confidence (probability), accuracy (error), timeliness (delay), throughput (amount) and cost (dollars). In this paper, we explore an aggregate set of metrics for fusion evaluation and demonstrate with information need metrics for dynamic situation analysis.

  18. Production of recombinant peptides as fusions with SUMO.

    PubMed

    Satakarni, Makkapati; Curtis, Robin

    2011-08-01

    Recombinant production of non-native peptides requires using protein fusion technology to prevent peptide degradation by host-cell proteases. In this work, we have used SUMO protein as a fusion partner for the production of difficult-to-express, antimicrobial, self-assembling and amyloidogenic peptides using Escherichia coli. SUMO-peptide fusions were expressed as intracellular products by utilizing pET based expression vectors constructed by Life Sensors Inc., USA. Histidine tagged SUMO-peptide fusions were purified using Ni-NTA affinity chromatography. Complete (100%) cleavage of the SUMO-peptide fusion was achieved using SUMO protease-1. Our findings demonstrate that SUMO fusion technology is a promising alternative for production of peptides in E. coli. The key advantage of this technology is that the enzymatic activity of SUMO protease-1 is specific and efficient leading to inexpensive costs for cleaving the peptide fusion when compared with other fusion systems. PMID:21586326

  19. Grand challenges of inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Nuckolls, J. H.

    2010-08-01

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

  20. Fusion energy

    NASA Astrophysics Data System (ADS)

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the Max Planck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989 to 1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R and D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R and D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  1. Fusion energy

    SciTech Connect

    Not Available

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the MaxPlanck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989--1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  2. COLLABORATIVE: FUSION SIMULATION PROGRAM

    SciTech Connect

    Chang, Choong Seock

    2012-06-05

    New York University, Courant Institute of Mathematical Sciences, participated in the “Fusion Simulation Program (FSP) Planning Activities” [http://www.pppl.gov/fsp], with C.S. Chang as the institutional PI. FSP’s mission was to enable scientific discovery of important new plasma phenomena with associated understanding that emerges only upon integration. This requires developing a predictive integrated simulation capability for magnetically-confined fusion plasmas that are properly validated against experiments in regimes relevant for producing practical fusion energy. Specific institutional goal of the New York University was to participate in the planning of the edge integrated simulation, with emphasis on the usage of large scale HPCs, in connection with the SciDAC CPES project which the PI was leading. New York University successfully completed its mission by participating in the various planning activities, including the edge physics integration, the edge science drivers, and the mathematical verification. The activity resulted in the combined report that can be found in http://www.pppl.gov/fsp/Overview.html. Participation and presentations as part of this project are listed in a separation file.

  3. Completely extruded talus without soft tissue attachments.

    PubMed

    Choi, Young Rak; Jeong, Jae Jung; Lee, Ho Seong; Kim, Sang Woo; Suh, Jin-Soo

    2011-03-29

    A completely extruded talus without any remaining soft tissue attachments is extremely rare. The present report describes treatment of a 45-year-old man who sustained a completely extruded talus injury following a rock-climbing fall. Upon admission, the extruded talus was deep-frozen in our bone bank. The open ankle joint underwent massive wound debridement and irrigation for 3 days. Four days later we performed a primary subtalar fusion between the extruded talus and the calcaneus, anticipating revascularization from the calcaneus. However, aseptic loosening and osteolysis developed around the screw and talus. At 12 months post-trauma we performed a tibiocalcaneal ankle fusion with a femoral head allograft to fill the talar defect. Follow-up at 24 months post-trauma showed the patient had midfoot motion, tibio-talar-calcaneal fusion, and was able partake in 4-hour physical activity twice per week. PMID:24765266

  4. Synthesis of superheavy elements and dinuclear-system concept of compound-nucleus formation

    SciTech Connect

    Antonenko, N.V.; Adamian, G.G.; Cherepanov, E.A.

    1996-12-31

    Dinuclear system concept is applied to the analysis of reactions used for the synthesis of elements with Z = 110, 112, 114, and 116. The inner fusion barriers obtained for these reactions are in good agreement with the experimental estimations resulted from the excitation energies of compound nuclei. A model is suggested for the calculation of the competition between complete fusion and quasifission in reactions with heavy nuclei. The fusion rate through the inner fusion barrier in mass asymmetry is found by using the multidimensional Kramers-type stationary solution of the Fokker-Planck equation. The influence of dissipative effects on the dynamics of nuclear fusion is considered.

  5. Feasibility study on sensor data fusion for the CP-140 aircraft: fusion architecture analyses

    NASA Astrophysics Data System (ADS)

    Shahbazian, Elisa

    1995-09-01

    Loral Canada completed (May 1995) a Department of National Defense (DND) Chief of Research and Development (CRAD) contract, to study the feasibility of implementing a multi- sensor data fusion (MSDF) system onboard the CP-140 Aurora aircraft. This system is expected to fuse data from: (a) attributed measurement oriented sensors (ESM, IFF, etc.); (b) imaging sensors (FLIR, SAR, etc.); (c) tracking sensors (radar, acoustics, etc.); (d) data from remote platforms (data links); and (e) non-sensor data (intelligence reports, environmental data, visual sightings, encyclopedic data, etc.). Based on purely theoretical considerations a central-level fusion architecture will lead to a higher performance fusion system. However, there are a number of systems and fusion architecture issues involving fusion of such dissimilar data: (1) the currently existing sensors are not designed to provide the type of data required by a fusion system; (2) the different types (attribute, imaging, tracking, etc.) of data may require different degree of processing, before they can be used within a fusion system efficiently; (3) the data quality from different sensors, and more importantly from remote platforms via the data links must be taken into account before fusing; and (4) the non-sensor data may impose specific requirements on the fusion architecture (e.g. variable weight/priority for the data from different sensors). This paper presents the analyses performed for the selection of the fusion architecture for the enhanced sensor suite planned for the CP-140 aircraft in the context of the mission requirements and environmental conditions.

  6. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C.

    2015-01-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. PMID:25866377

  7. Slow liner fusion

    SciTech Connect

    Shaffer, M.J.

    1997-08-01

    {open_quotes}Slow{close_quotes} liner fusion ({approximately}10 ms compression time) implosions are nondestructive and make repetitive ({approximately} 1 Hz) pulsed liner fusion reactors possible. This paper summarizes a General Atomics physics-based fusion reactor study that showed slow liner feasibility, even with conservative open-line axial magnetic field confinement and Bohm radial transport.

  8. Magneto-Inertial Fusion

    DOE PAGESBeta

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

    2015-11-17

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

  9. Cold fusion research

    SciTech Connect

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  10. Cluster-impact fusion

    SciTech Connect

    Echenique, P.M.; Manson, J.R.; Ritchie, R.H. )

    1990-03-19

    We present a model for the cluster-impact-fusion experiments of Buehler, Friedlander, and Friedman, Calculated fusion rates as a function of bombarding energy for constant cluster size agree well with experiment. The dependence of the fusion rate on cluster size at fixed bombarding energy is explained qualitatively. The role of correlated, coherent collisions in enhanced energy loss by clusters is emphasized.

  11. Impact of Reaction Cross Section on the Unified Description of Fusion Excitation Function

    NASA Astrophysics Data System (ADS)

    Basrak, Z.; Eudes, P.; de la Mota, V.; Sébille, F.; Royer, G.

    A systematics of over 300 complete and incomplete fusion cross section data points covering energies beyond the barrier for fusion is presented. Owing to a usual reduction of the fusion cross sections by the total reaction cross sections and an original scaling of energy, a fusion excitation function common to all the data points is established. A universal description of the fusion exci- tation function relying on basic nuclear concepts is proposed and its dependence on the reaction cross section used for the cross section normalization is discussed. The pioneering empirical model proposed by Bass in 1974 to describe the complete fusion cross sections is rather successful for the incomplete fusion too and provides cross section predictions in satisfactory agreement with the observed universality of the fusion excitation function. The sophisticated microscopic transport DYWAN model not only reproduces the data but also predicts that fusion reaction mechanism disappears due to weakened nuclear stopping power around the Fermi energy.

  12. Elements of Successful and Safe Fusion Experiment Operations

    SciTech Connect

    K. Rule, L. Cadwallader, Y. Takase, T. Norimatsu, O. Kaneko, M. Sato, and R. Savercool

    2009-02-03

    A group of fusion safety professionals contribute to a Joint Working Group (JWG) that performs occupational safety walkthroughs of US and Japanese fusion experiments on a routine basis to enhance the safety of visiting researchers. The most recent walkthrough was completed in Japan in March 2008 by the US Safety Monitor team. This paper gives the general conclusions on fusion facility personnel safety that can be drawn from the series of walkthroughs.

  13. Secretion is required for late events in the cell-fusion pathway of mating yeast.

    PubMed

    Grote, Eric

    2010-06-01

    Secretory vesicles accumulate adjacent to the contact site between the two cells of a yeast mating pair before they fuse, but there is no direct evidence that secretion is required to complete fusion. In this study, temperature-sensitive secretion (sec(ts)) mutants were used to investigate the role of secretion in yeast cell fusion. Cell fusion arrested less than 5 minutes after inhibiting secretion. This rapid fusion arrest was not an indirect consequence of reduced mating pheromone signaling, mating-pair assembly or actin polarity. Furthermore, secretion was required to complete cell fusion when it was transiently inhibited by addition and removal of the lipophilic styryl dye, FM4-64. These results indicate that ongoing secretion is required for late events in the cell-fusion pathway, which include plasma-membrane fusion and the completion of cell-wall remodeling, and they demonstrate a just-in-time delivery mechanism for the cell-fusion machinery. PMID:20460435

  14. Interplanetary propulsion using inertial fusion

    NASA Technical Reports Server (NTRS)

    Orth, C. D.; Hogan, W. J.; Hoffman, N.; Murray, K.; Klein, G.; Diaz, F. C.

    1987-01-01

    Inertial fusion can be used to power spacecraft within the solar system and beyond. Such spacecraft have the potential for short-duration manned-mission performance exceeding other technologies. We are conducting a study to assess the systems aspects of inertial fusion as applied to such missions, based on the conceptual engine design of Hyde (1983) we describe the required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel. We give preliminary design details for the power conversion and power conditioning systems for manned missions to Mars of total duration of about 100 days. Specific mission performance results will be published elsewhere, after the study has been completed.

  15. Viral membrane fusion

    SciTech Connect

    Harrison, Stephen C.

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

  16. Spin-distribution measurement: A sensitive probe for incomplete fusion dynamics

    SciTech Connect

    Singh, Pushpendra P.; Singh, B. P.; Sharma, Manoj Kumar; Unnati,; Singh, D.; Ansari, M. A.; Prasad, R.; Kumar, R.; Golda, K. S.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.

    2008-07-15

    Spin distributions of various reaction products populated via complete and/or incomplete fusion of {sup 16}O with {sup 169}Tm have been measured at projectile energy {approx_equal}5.6 MeV/nucleon. Particle (Z=1,2) {gamma}-coincidences have been employed to achieve the information about involved reaction modes on the basis of their entry state spin populations. The experimentally measured spin distributions for incomplete fusion products have been found to be distinctly different than those observed for complete fusion products. The driving input angular momenta associated with incomplete fusion products have been found to be relatively higher than complete fusion products, and increases with direct {alpha}-multiplicity. It has also been observed that incomplete fusion products are less fed and/or the population of lower spin states are strongly hindered, while complete fusion products indicating strong feeding over a broad spin range.

  17. The fusion breeder

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1982-10-01

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the U.S. fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the U.S. fusion program and the U.S. nuclear energy program. There is wide agreement that many approaches will work and will produce fuel for five equal-sized LWRs, and some approach as many as 20 LWRs at electricity costs within 20% of those at today's price of uranium (30/lb of U3O8). The blankets designed to suppress fissioning, called symbiotes, fusion fuel factories, or just fusion breeders, will have safety characteristics more like pure fusion reactors and will support as many as 15 equal power LWRs. The blankets designed to maximize fast fission of fertile material will have safety characteristics more like fission reactors and will support 5 LWRs. This author strongly recommends development of the fission suppressed blanket type, a point of view not agreed upon by everyone. There is, however, wide agreement that, to meet the market price for uranium which would result in LWR electricity within 20% of today's cost with either blanket type, fusion components can cost severalfold more than would be allowed for pure fusion to meet the goal of making electricity alone at 20% over today's fission costs. Also widely agreed is that the critical-path-item for the fusion breeder is fusion development itself; however, development of fusion breeder specific items (blankets, fuel cycle) should be started now in order to have the fusion breeder by the time the rise in uranium prices forces other more costly choices.

  18. Fusion probability in heavy nuclei

    NASA Astrophysics Data System (ADS)

    Banerjee, Tathagata; Nath, S.; Pal, Santanu

    2015-03-01

    Background: Fusion between two massive nuclei is a very complex process and is characterized by three stages: (a) capture inside the potential barrier, (b) formation of an equilibrated compound nucleus (CN), and (c) statistical decay of the CN leading to a cold evaporation residue (ER) or fission. The second stage is the least understood of the three and is the most crucial in predicting yield of superheavy elements (SHE) formed in complete fusion reactions. Purpose: A systematic study of average fusion probability, , is undertaken to obtain a better understanding of its dependence on various reaction parameters. The study may also help to clearly demarcate onset of non-CN fission (NCNF), which causes fusion probability, PCN, to deviate from unity. Method: ER excitation functions for 52 reactions leading to CN in the mass region 170-220, which are available in the literature, have been compared with statistical model (SM) calculations. Capture cross sections have been obtained from a coupled-channels code. In the SM, shell corrections in both the level density and the fission barrier have been included. for these reactions has been extracted by comparing experimental and theoretical ER excitation functions in the energy range ˜5 %-35% above the potential barrier, where known effects of nuclear structure are insignificant. Results: has been shown to vary with entrance channel mass asymmetry, η (or charge product, ZpZt ), as well as with fissility of the CN, χCN. No parameter has been found to be adequate as a single scaling variable to determine . Approximate boundaries have been obtained from where starts deviating from unity. Conclusions: This study quite clearly reveals the limits of applicability of the SM in interpreting experimental observables from fusion reactions involving two massive nuclei. Deviation of from unity marks the beginning of the domain of dynamical models of fusion. Availability of precise ER cross

  19. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  20. Fusion Simulation Program Definition. Final report

    SciTech Connect

    Cary, John R.

    2012-09-05

    We have completed our contributions to the Fusion Simulation Program Definition Project. Our contributions were in the overall planning with concentration in the definition of the area of Software Integration and Support. We contributed to the planning of multiple meetings, and we contributed to multiple planning documents.

  1. Muon Catalyzed Fusion

    NASA Technical Reports Server (NTRS)

    Armour, Edward A.G.

    2007-01-01

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

  2. Observation of incomplete fusion reactions at l < l {sub crit}

    SciTech Connect

    Yadav, Abhishek Sharma, Vijay R. Singh, Devendra P. Unnati,; Singh, B. P.; Prasad, R.; Singh, Pushpendra P.; Bala, Indu; Kumar, R.; Muralithar, S.; Singh, R. P.; Sharma, M. K.

    2014-08-14

    In order to understand the presence of incomplete fusion at low energies i.e. 4-7MeV/nucleon and also to study its dependence on various entrance-channel parameters, the two type of measurements (i) excitation function for {sup 12}C+{sup 159}Tb, and (ii) forward recoil ranges for {sup 12}C+{sup 159}Tb systems have been performed. The experimentally measured excitation functions have been analyzed within the framework of compound nucleus decay using statistical model code PACE4. Analysis of data suggests the production of xn/px)n-channels via complete fusion, as these are found to be well reproduced by PACE4 predictions, while, a significant enhancement in the excitation functions of α-emitting channels has been observed over the theoretical ones, which has been attributed due to the incomplete fusion processes. Further, the incomplete fusion events observed in case of forward recoil range measurements have been explained on the basis of the breakup fusion model, where these events may be attributed to the fusion of {sup 8}Be and/or {sup 4}He from {sup 12}C projectile to the target nucleus. In the present work, the SUMRULE model calculations are found to highly underestimate the observed incomplete fusion cross-sections which indicate that the l-values lower than l {sub crit} (limit of complete fusion) significantly contribute to the incomplete fusion reactions.

  3. Laser fusion target illumination system.

    PubMed

    Thomas, C E

    1975-06-01

    Laser fusion experiments require the focusing of very intense pulsed laser beams onto very small fuel pellets. All reported experiments to date have used lenses to focus one or more laser beams onto the target. This paper describes a combined refractive/reflective illumination system that provides nearly uniform irradiance with nearly orthogonal incidence over the complete spherical target, with only two laser beams. This illumination system was used in the experiments that produced the first known symmetric target implosions. Furthermore, these experiments produced what we believe were the first thermonuclear neutrons generated by a laser-driven implosion. PMID:20154815

  4. National Mirror Fusion Program Plan

    SciTech Connect

    Gerich, C.A.

    1982-08-01

    This Plan is current as of August 1982. The major milestones listed herein represent an aggressive, success-oriented program paced primarily by technical results. Consistent with applicable government policies and the overall program planning of the Department's Office of Fusion Energy, this Plan assumes approval of the Mirror Program's next major step beyond MFTF-B - a deuterium-tritium (D-T) burning engineering reactor called the Fusion Power Demonstration (FPD) facility (formerly the Tandem Mirror Next Step). The near-term goal of the tandem mirror program is to lay the scientific and technical groundwork for an economically attractive, D-T fusion reactor design before the end of the 1980s. Construction of the FPD facility based on the tandem mirror could be initited around 1988. A second phase, complete with a nuclear power blanket demonstration, could be initiated in the mid-1990s, based on nuclear engineering data from a facility such as the Technology Demonstration Facility (TDF) described below. The outline of an acceptable tandem mirror reactor (TMR) design was first published in 1981, and will be further developed and described in the Mirror Advanced Reactor Study (MARS) during FY 1982-1983.

  5. Magnetic-confinement fusion

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  6. Comparison of SUMO fusion technology with traditional gene fusion systems: enhanced expression and solubility with SUMO.

    PubMed

    Marblestone, Jeffrey G; Edavettal, Suzanne C; Lim, Yiting; Lim, Peter; Zuo, Xun; Butt, Tauseef R

    2006-01-01

    Despite the availability of numerous gene fusion systems, recombinant protein expression in Escherichia coli remains difficult. Establishing the best fusion partner for difficult-to-express proteins remains empirical. To determine which fusion tags are best suited for difficult-to-express proteins, a comparative analysis of the newly described SUMO fusion system with a variety of commonly used fusion systems was completed. For this study, three model proteins, enhanced green fluorescent protein (eGFP), matrix metalloprotease-13 (MMP13), and myostatin (growth differentiating factor-8, GDF8), were fused to the C termini of maltose-binding protein (MBP), glutathione S-transferase (GST), thioredoxin (TRX), NUS A, ubiquitin (Ub), and SUMO tags. These constructs were expressed in E. coli and evaluated for expression and solubility. As expected, the fusion tags varied in their ability to produce tractable quantities of soluble eGFP, MMP13, and GDF8. SUMO and NUS A fusions enhanced expression and solubility of recombinant proteins most dramatically. The ease at which SUMO and NUS A fusion tags were removed from their partner proteins was then determined. SUMO fusions are cleaved by the natural SUMO protease, while an AcTEV protease site had to be engineered between NUS A and its partner protein. A kinetic analysis showed that the SUMO and AcTEV proteases had similar KM values, but SUMO protease had a 25-fold higher kcat than AcTEV protease, indicating a more catalytically efficient enzyme. Taken together, these results demonstrate that SUMO is superior to commonly used fusion tags in enhancing expression and solubility with the distinction of generating recombinant protein with native sequences. PMID:16322573

  7. Direct observation of intermediate states in model membrane fusion

    NASA Astrophysics Data System (ADS)

    Keidel, Andrea; Bartsch, Tobias F.; Florin, Ernst-Ludwig

    2016-03-01

    We introduce a novel assay for membrane fusion of solid supported membranes on silica beads and on coverslips. Fusion of the lipid bilayers is induced by bringing an optically trapped bead in contact with the coverslip surface while observing the bead’s thermal motion with microsecond temporal and nanometer spatial resolution using a three-dimensional position detector. The probability of fusion is controlled by the membrane tension on the particle. We show that the progression of fusion can be monitored by changes in the three-dimensional position histograms of the bead and in its rate of diffusion. We were able to observe all fusion intermediates including transient fusion, formation of a stalk, hemifusion and the completion of a fusion pore. Fusion intermediates are characterized by axial but not lateral confinement of the motion of the bead and independently by the change of its rate of diffusion due to the additional drag from the stalk-like connection between the two membranes. The detailed information provided by this assay makes it ideally suited for studies of early events in pure lipid bilayer fusion or fusion assisted by fusogenic molecules.

  8. Direct observation of intermediate states in model membrane fusion.

    PubMed

    Keidel, Andrea; Bartsch, Tobias F; Florin, Ernst-Ludwig

    2016-01-01

    We introduce a novel assay for membrane fusion of solid supported membranes on silica beads and on coverslips. Fusion of the lipid bilayers is induced by bringing an optically trapped bead in contact with the coverslip surface while observing the bead's thermal motion with microsecond temporal and nanometer spatial resolution using a three-dimensional position detector. The probability of fusion is controlled by the membrane tension on the particle. We show that the progression of fusion can be monitored by changes in the three-dimensional position histograms of the bead and in its rate of diffusion. We were able to observe all fusion intermediates including transient fusion, formation of a stalk, hemifusion and the completion of a fusion pore. Fusion intermediates are characterized by axial but not lateral confinement of the motion of the bead and independently by the change of its rate of diffusion due to the additional drag from the stalk-like connection between the two membranes. The detailed information provided by this assay makes it ideally suited for studies of early events in pure lipid bilayer fusion or fusion assisted by fusogenic molecules. PMID:27029285

  9. Direct observation of intermediate states in model membrane fusion

    PubMed Central

    Keidel, Andrea; Bartsch, Tobias F.; Florin, Ernst-Ludwig

    2016-01-01

    We introduce a novel assay for membrane fusion of solid supported membranes on silica beads and on coverslips. Fusion of the lipid bilayers is induced by bringing an optically trapped bead in contact with the coverslip surface while observing the bead’s thermal motion with microsecond temporal and nanometer spatial resolution using a three-dimensional position detector. The probability of fusion is controlled by the membrane tension on the particle. We show that the progression of fusion can be monitored by changes in the three-dimensional position histograms of the bead and in its rate of diffusion. We were able to observe all fusion intermediates including transient fusion, formation of a stalk, hemifusion and the completion of a fusion pore. Fusion intermediates are characterized by axial but not lateral confinement of the motion of the bead and independently by the change of its rate of diffusion due to the additional drag from the stalk-like connection between the two membranes. The detailed information provided by this assay makes it ideally suited for studies of early events in pure lipid bilayer fusion or fusion assisted by fusogenic molecules. PMID:27029285

  10. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  11. Congenital Bilateral Zygomatico-Maxillo-Mandibular Fusion Associated With Gum Fusion.

    PubMed

    Al-Mahdi, Akmam H; Koppel, David A; Al-Jumaily, Hassanien A; Mohammed, Ali Abdul Hameed; Boyd, Deborah

    2016-01-01

    A congenial syngnathia is very rare condition. It can be simple mucosal fusion (synechiae), or complete bony fusion (synostosis) between the maxilla or zygoma and the mandible. Fusion of the ascending ramus of mandible to maxilla and zygoma is less common than fusions of the alveolar ridges of the mandible to the maxilla. Bony syngnathia is either isolated or complex in form. There are 59 cases of congenital bony syngnathia reported in the literature: the first report was by Burket in 1936. There are 16 reported cases of zygomatico-maxillo-mandibular fusion. In the reported cases, women expressed the isolated form more commonly whereas men demonstrated a more complex pattern of disease. The authors present another patient of bony syngnathia involving bilateral fusion of the ascending ramus and body of the mandible with the maxillary complex in a young man. Early surgery was performed to release the bony and soft tissue fusion on the eighth day from the baby's birth. A second operation was performed for recurrence when the baby was 2.5 months old. A customized splint, an intense postoperative program of mouth exercises, and close follow-up aims to prevent further refusion. PMID:26703053

  12. Effect of the Target Deformation on Incomplete Fusion Dynamics

    NASA Astrophysics Data System (ADS)

    Singh, D.; Ali, Rahbar; Afzal Ansari, M.; Kumar, R.; Singh, R. P.; Muralither, S.; Bhowmik, R. K.

    2015-01-01

    To investigate the role of target deformation on incomplete fusion dynamics, a particle-gamma coincidence experiment has been performed at Inter University Accelerator Centre, New Delhi. Spin distributions for various evaporation residues populated via complete and incomplete fusion of 16O with 124Sn at 6.3MeV/nucleon have been measured. Experimentally measured spin distributions of the residues produced as incomplete fusion products associated with fast α and 2α-emission channels observed in forward cone are found to be distinctly different from those of the residues produced as complete fusion products. The mean value of input angular momentum J0 for evaporation residues produced through xn channels (complete fusion products) is found to be J0≈ 7ħ, while the mean value of input angular momentum J0 for the residues produced through direct αxn and 2αxn channels (incomplete fusion products) in forward cone, are found to be J0 ≈ 9ħ and ≈ 12ħ respectively for 16O + 124Sn (spherical) system [7]. The mean value of input angular momentum J0 for the system 16O + 169Tm (deformed) reported in ref. [8], are found to be ≈10ħ for xn-channels (complete fusion products) and for direct αxn and 2αxn channels (incomplete fusion products) the value of J0 approaches to ≈ 13ħ and ≈16ħ, respectively. The mean values of the input angular momentum observed for xn (complete fusion products), αxn and 2αxn (incomplete fusion products) in 16O + 124Sn (spherical) system are smaller than that of the mean values of the input angular momentum observed for xn (complete fusion products), αxn and 2αxn (incomplete fusion products) in 16O + 169Tm (deformed) system. The comparison of data inferred that the mean values of the input angular momentum are smaller in case of spherical target than that of deformed target at same projectile energy of 16O-ion beam. It means that the target deformation affect the incomplete fusion dynamics.

  13. Complete Fusion and Break-up Fusion Reactions in Light Ion Interactions at Low Energies

    SciTech Connect

    Cerutti, F.; Ferrari, A.; Gadioli, E.; Mairani, A.; Foertsch, S. V.; Buthelezi, E. Z.; Fujita, H.; Neveling, R.; Smit, F. D.; Dlamini, J.; Cowley, A. A.; Connell, S. H.

    2007-10-26

    Experimental spectra of intermediate mass fragments (IMFs) produced in the interaction of two {sup 12}C ions at incident energy of 200 MeV and their reproduction by a binary fragmentation model and the Boltzmann Master Equation theory as implemented into the Monte Carlo transport and interaction code FLUKA are shown.

  14. Low latency long wave infrared visible fusion

    NASA Astrophysics Data System (ADS)

    Robison, Derek

    2014-06-01

    Human factors issues related to head mounted imaging systems have driven the requirements for system latency to nearly the bounds of sensor physics. Image processing must therefore be performed in an envelope that is ever decreasing in size. This paper presents a complete method for intelligent fusion of a long wave infrared and visible sensor, including contrast enhancement in both spectrums, with end to end processing latency of less than 1 millisecond. The use of image statistics and opponent color theory allows fusion with minimal computational resources and latency. This algorithm has demonstrated performance without inducing any noticeable human factors issues during user trials.

  15. Fusion Science Education Outreach

    NASA Astrophysics Data System (ADS)

    Danielson, C. A.; DIII-D Education Group

    1996-11-01

    This presentation will focus on education outreach activities at General Atomics that have been expanded to include the general population on science education with a focus on fusion energy. Outreach materials are distributed upon request both nationally and internationally. These materials include a notebook containing copies of DIII--D tour panels, fusion poster, new fusion energy video, new fusion energy brochure, and the electromagnetic spectrum curriculum. The 1996 Fusion Forum (held in the House Caucus Room) included a student/ teacher lunch with Energy Secretary Hazel O'Leary and a private visit to the Forum exhibits. The continuing partnership with Kearny High School includes lectures, job shadowing, internship, equipment donations and an award-winning electric car-racing program. Development of distribution by CD of the existing interactive fusion energy kiosk and a virtual reality tour of the DIII--D facility are underway. The DIII--D fusion education WWW site includes e-mail addresses to ``Ask the Wizard,'' and/or receive GA's outreach materials. Steve Rodecker, a local science teacher, aided by DIII--D fusion staff, won his second Tapestry Award; he also was named the ``1995 National Science Teacher of the Year'' and will be present to share his experiences with the DIII--D educational outreach program.

  16. Two Horizons of Fusion

    ERIC Educational Resources Information Center

    Lo, Mun Ling; Chik, Pakey Pui Man

    2016-01-01

    In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

  17. Controlled Nuclear Fusion.

    ERIC Educational Resources Information Center

    Glasstone, Samuel

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

  18. Magnetic systems for fusion devices

    SciTech Connect

    Henning, C.D.

    1985-02-01

    Mirror experiments have led the way in applying superconductivity to fusion research because of unique requirements for high and steady magnetic fields. The first significant applications were Baseball II at LLNL and IMP at ORNL. More recently, the MFTF-B yin-yang coil was successfully tested and the entire tandem configuration is nearing completion. Tokamak magnets have also enjoyed recent success with the large coil project tests at ORNL, preceded by single coil tests in Japan and Germany. In the USSR, the T-7 Tokamak has been operational for many years and the T-15 Tokamak is under construction, with the TF coils nearing completion. Also the Tore Supra is being built in France.

  19. Decomposition of incomplete fusion

    SciTech Connect

    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 /sup 28/Si+/sup 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.

  20. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

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

  1. Membrane Fusion Induced by Small Molecules and Ions

    PubMed Central

    Mondal Roy, Sutapa; Sarkar, Munna

    2011-01-01

    Membrane fusion is a key event in many biological processes. These processes are controlled by various fusogenic agents of which proteins and peptides from the principal group. The fusion process is characterized by three major steps, namely, inter membrane contact, lipid mixing forming the intermediate step, pore opening and finally mixing of inner contents of the cells/vesicles. These steps are governed by energy barriers, which need to be overcome to complete fusion. Structural reorganization of big molecules like proteins/peptides, supplies the required driving force to overcome the energy barrier of the different intermediate steps. Small molecules/ions do not share this advantage. Hence fusion induced by small molecules/ions is expected to be different from that induced by proteins/peptides. Although several reviews exist on membrane fusion, no recent review is devoted solely to small moleculs/ions induced membrane fusion. Here we intend to present, how a variety of small molecules/ions act as independent fusogens. The detailed mechanism of some are well understood but for many it is still an unanswered question. Clearer understanding of how a particular small molecule can control fusion will open up a vista to use these moleucles instead of proteins/peptides to induce fusion both in vivo and in vitro fusion processes. PMID:21660306

  2. Spherical torus fusion reactor

    DOEpatents

    Martin Peng, Y.K.M.

    1985-10-03

    The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

  3. Amodal Completion in Bonobos

    ERIC Educational Resources Information Center

    Nagasaka, Yasuo; Brooks, Daniel I.; Wasserman, Edward A.

    2010-01-01

    We trained two bonobos to discriminate among occluded, complete, and incomplete stimuli. The occluded stimulus comprised a pair of colored shapes, one of which appeared to occlude the other. The complete and incomplete stimuli involved the single shape that appeared to have been partially covered in the occluded stimulus; the complete stimulus…

  4. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  5. Sensor fusion for intelligent alarm analysis

    SciTech Connect

    Nelson, C.L.; Fitzgerald, D.S.

    1995-03-01

    The purpose of an intelligent alarm analysis system is to provide complete and manageable information to a central alarm station operator by applying alarm processing and fusion techniques to sensor information. This paper discusses the sensor fusion approach taken to perform intelligent alarm analysis for the Advanced Exterior Sensor (AES). The AES is an intrusion detection and assessment system designed for wide-area coverage, quick deployment, low false/nuisance alarm operation, and immediate visual assessment. It combines three sensor technologies (visible, infrared, and millimeter wave radar) collocated on a compact and portable remote sensor module. The remote sensor module rotates at a rate of 1 revolution per second to detect and track motion and provide assessment in a continuous 360` field-of-regard. Sensor fusion techniques are used to correlate and integrate the track data from these three sensors into a single track for operator observation. Additional inputs to the fusion process include environmental data, knowledge of sensor performance under certain weather conditions, sensor priority, and recent operator feedback. A confidence value is assigned to the track as a result of the fusion process. This helps to reduce nuisance alarms and to increase operator confidence in the system while reducing the workload of the operator.

  6. Gene Fusion: A Genome Wide Survey

    NASA Technical Reports Server (NTRS)

    Liang, Ping; Riley, Monica

    2001-01-01

    As a well known fact, organisms form larger and complex multimodular (composite or chimeric) and mostly multi-functional proteins through gene fusion of two or more individual genes which have independent evolution histories and functions. We call each of these components a module. The existence of multimodular proteins may improves the efficiency in gene regulation and in cellular functions, and thus may give the host organism advantages in adaptation to environments. Analysis of all gene fusions in present-day organisms should allow us to examine the patterns of gene fusion in context with cellular functions, to trace back the evolution processes from the ancient smaller and uni-functional proteins to the present-day larger and complex multi-functional proteins, and to estimate the minimal number of ancestor proteins that existed in the last common ancestor for all life on earth. Although many multimodular proteins have been experimentally known, identification of gene fusion events systematically at genome scale had not been possible until recently when large number of completed genome sequences have been becoming available. In addition, technical difficulties for such analysis also exist due to the complexity of this biological and evolutionary process. We report from this study a new strategy to computationally identify multimodular proteins using completed genome sequences and the results surveyed from 22 organisms with the data from over 40 organisms to be presented during the meeting. Additional information is contained in the original extended abstract.

  7. Cdc42 controls the dilation of the exocytotic fusion pore by regulating membrane tension

    PubMed Central

    Bretou, Marine; Jouannot, Ouardane; Fanget, Isabelle; Pierobon, Paolo; Larochette, Nathanaël; Gestraud, Pierre; Guillon, Marc; Emiliani, Valentina; Gasman, Stéphane; Desnos, Claire; Lennon-Duménil, Ana-Maria; Darchen, François

    2014-01-01

    Membrane fusion underlies multiple processes, including exocytosis of hormones and neurotransmitters. Membrane fusion starts with the formation of a narrow fusion pore. Radial expansion of this pore completes the process and allows fast release of secretory compounds, but this step remains poorly understood. Here we show that inhibiting the expression of the small GTPase Cdc42 or preventing its activation with a dominant negative Cdc42 construct in human neuroendocrine cells impaired the release process by compromising fusion pore enlargement. Consequently the mode of vesicle exocytosis was shifted from full-collapse fusion to kiss-and-run. Remarkably, Cdc42-knockdown cells showed reduced membrane tension, and the artificial increase of membrane tension restored fusion pore enlargement. Moreover, inhibiting the motor protein myosin II by blebbistatin decreased membrane tension, as well as fusion pore dilation. We conclude that membrane tension is the driving force for fusion pore dilation and that Cdc42 is a key regulator of this force. PMID:25143404

  8. Progress toward fusion energy

    SciTech Connect

    Thomassen, K.I.

    1981-03-11

    This paper summarizes the basis for the present optimism in the magnetic fusion program, and describes some of the remaining tasks leading to a demonstration power reactor and the primary technologies necessary for that endeavor.

  9. Label fusion strategy selection.

    PubMed

    Robitaille, Nicolas; Duchesne, Simon

    2012-01-01

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

  10. HIV-1 Fusion Assay

    PubMed Central

    Cavrois, Marielle; Neidleman, Jason; Greene, Warner C.

    2016-01-01

    The HIV-1 fusion assay measures all steps in the HIV-1 life cycle up to and including viral fusion. It relies on the incorporation of a β-lactamase Vpr (BlaM-Vpr) protein chimera into the virion and the subsequent transfer of this chimera into the target cell by fusion (Figure 1). The transfer is monitored by the enzymatic cleavage of CCF2, a fluorescent dye substrate of β-lactamase, loaded into the target cells. Cleavage of the β-lactam ring in CCF2 by β-lactamase changes the fluorescence emission spectrum of the dye from green (520 nm) to blue (447 nm). This change reflects virion fusion and can be detected by flow cytometry (Figure 2).

  11. Fusion power demonstration

    SciTech Connect

    Henning, C.D.; Logan, B.G.

    1983-09-01

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

  12. Laser-Driven Fusion.

    ERIC Educational Resources Information Center

    Gibson, A. F.

    1980-01-01

    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  13. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

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

  14. Glossary of fusion energy

    SciTech Connect

    Whitson, M.O.

    1985-02-01

    The Glossary of Fusion Energy is an attempt to present a concise, yet comprehensive collection of terms that may be beneficial to scientists and laymen who are directly or tangentially concerned with this burgeoning energy enterprise. Included are definitions of terms in theoretical plasma physics, controlled thermonuclear fusion, and some related physics concepts. Also, short descriptions of some of the major thermonuclear experiments currently under way in the world today are included.

  15. Advances in fusion technology

    NASA Astrophysics Data System (ADS)

    Baker, Charles C.

    2000-12-01

    The US fusion technology program is an essential element in the development of the knowledge base for an attractive fusion power source. The technology program incorporates both near and long term R&D, contributes to material and engineering sciences as well as technology development, ranges from hardware production to theory and modeling, contributes significantly to spin-off applications, and performs global systems assessments and focused design studies.

  16. Systematics for low energy incomplete fusion: Still a puzzle?

    NASA Astrophysics Data System (ADS)

    Yadav, Abhishek; Shuaib, Mohd; Aggarwal, Abhay V.; Sharma, Vijay R.; Bala, Indu; Singh, D. P.; Singh, P. P.; Unnati; Sharma, M. K.; Kumar, R.; Singh, R. P.; Muralithar, S.; Singh, B. P.; Prasad, R.

    2016-05-01

    In order to have a better and clear picture of incomplete fusion reactions at energies ≈4-7MeV/nucleon, the excitation function measurements have been performed for 18O+159Tb system. The experimental data have been analyzed within the framework of compound nucleus decay. The cross-section for xn/pxn-channels are found to be well reproduced by PACE4 predictions, which suggest their production via complete fusion process. However, a significant enhancement in the excitation functions of α-emitting channels has been observed over the theoretical ones, which has been attributed due to the incomplete fusion processes. The incomplete fusion fractions have been deduced at each studied energy and compared with other nearby systems for better insight into the underlying dynamics. The incomplete fusion fraction has been found to be sensitive to the projectile's energy and α-Q-value.

  17. Magnetized Target Fusion

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.

    2002-01-01

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

  18. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2010-01-08

    ITER (in Latin ?the way?) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen ? deuterium and tritium ? fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project ? China, the European Union, India, Japan, Korea, Russia and the United States ? represent more than half the world?s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

  19. COMPLETE SURFACE MAPPING OF ICF SHELLS

    SciTech Connect

    STEPHENS,R.B; OLSON,D; HUANG,H; GIBSON,J.B

    2003-06-01

    OAK-B135 Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. they have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r({theta},{psi}) surface map for accurate 3-D modeling of a shot.

  20. Investigation of contribution of incomplete fusion in the total fusion process induced by 9Be on 181Ta target at near barrier energies

    NASA Astrophysics Data System (ADS)

    Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

    2016-02-01

    We have studied the relative contribution of incomplete fusion (ICF) and complete fusion (CF) in total fusion (TF) induced by 9Be on 181Ta target at energies in the vicinity of Coulomb barrier using classical dynamical model and Wong's formula in conjugation with energy dependent Woods-Saxon formula. It is found that at above barrier energies ICF contributes almost 30% in TF while at energies below the barrier qualitatively its contribution is much more than thirty percent.

  1. Spatial Statistical Data Fusion for Remote Sensing Applications

    NASA Technical Reports Server (NTRS)

    Nguyen, Hai

    2010-01-01

    Data fusion is the process of combining information from heterogeneous sources into a single composite picture of the relevant process, such that the composite picture is generally more accurate and complete than that derived from any single source alone. Data collection is often incomplete, sparse, and yields incompatible information. Fusion techniques can make optimal use of such data. When investment in data collection is high, fusion gives the best return. Our study uses data from two satellites: (1) Multiangle Imaging SpectroRadiometer (MISR), (2) Moderate Resolution Imaging Spectroradiometer (MODIS).

  2. Complete analyticity for 2D Ising completed

    NASA Astrophysics Data System (ADS)

    Schonmann, Roberto H.; Shlosman, Senya B.

    1995-06-01

    We study the behavior of the two-dimensional nearest neighbor ferromagnetic Ising model under an external magnetic field h. We extend to every subcritical value of the temperature a result previously proven by Martirosyan at low enough temperature, and which roughly states that for finite systems with — boundary conditions under a positive external field, the boundary effect dominates in the bulk if the linear size of the system is of order B/h with B small enough, while if B is large enough, then the external field dominates in the bulk. As a consequence we are able to complete the proof that “complete analyticity for nice sets” holds for every value of the temperature and external field in the interior of the uniqueness region in the phase diagram of the model. The main tools used are the results and techniques developed to study large deviations for the block magnetization in the absence of the magnetic field, and recently extended to all temperatures below the critical one by Ioffe.

  3. Matched Comparison of Fusion Rates between Hydroxyapatite Demineralized Bone Matrix and Autograft in Lumbar Interbody Fusion

    PubMed Central

    Kim, Dae Hwan; Lee, Nam; Shin, Dong Ah; Yi, Seong; Kim, Keung Nyun

    2016-01-01

    Objective To compare the fusion rate of a hydroxyapatite demineralized bone matrix (DBM) with post-laminectomy acquired autograft in lumbar interbody fusion surgery and to evaluate the correlation between fusion rate and clinical outcome. Methods From January 2013 to April 2014, 98 patients underwent lumbar interbody fusion surgery with hydroxyapatite DBM (HA-DBM group) in our institute. Of those patients, 65 received complete CT scans for 12 months postoperatively in order to evaluate fusion status. For comparison with autograft, we selected another 65 patients who underwent lumbar interbody fusion surgery with post-laminectomy acquired autograft (Autograft group) during the same period. Both fusion material groups were matched in terms of age, sex, body mass index (BMI), and bone mineral density (BMD). To evaluate the clinical outcomes, we analyzed the results of visual analogue scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey (SF-36). Results We reviewed the CT scans of 149 fusion levels in 130 patients (HA-DBM group, 75 levels/65 patients; Autograft group, 74 levels/65 patients). Age, sex, BMI, and BMD were not significantly different between the groups (p=0.528, p=0.848, p=0.527, and p=0.610, respectively). The HA-DBM group showed 39 of 75 fused levels (52%), and the Autograft group showed 46 of 74 fused levels (62.2%). This difference was not statistically significant (p=0.21). In the HA-DBM group, older age and low BMD were significantly associated with non-fusion (61.24 vs. 66.68, p=0.027; -1.63 vs. -2.29, p=0.015, respectively). VAS and ODI showed significant improvement after surgery when fusion was successfully achieved in both groups (p=0.004, p=0.002, HA-DBM group; p=0.012, p=0.03, Autograft group). Conclusion The fusion rates of the hydroxyapatite DBM and Autograft groups were not significantly different. In addition, clinical outcomes were similar between the groups. However, older age and low BMD are risk factors that might

  4. Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

    NASA Astrophysics Data System (ADS)

    Diaz-Torres, A.; Boselli, M.

    2016-05-01

    Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.

  5. Multisensor Fusion for Change Detection

    NASA Astrophysics Data System (ADS)

    Schenk, T.; Csatho, B.

    2005-12-01

    Combining sensors that record different properties of a 3-D scene leads to complementary and redundant information. If fused properly, a more robust and complete scene description becomes available. Moreover, fusion facilitates automatic procedures for object reconstruction and modeling. For example, aerial imaging sensors, hyperspectral scanning systems, and airborne laser scanning systems generate complementary data. We describe how data from these sensors can be fused for such diverse applications as mapping surface erosion and landslides, reconstructing urban scenes, monitoring urban land use and urban sprawl, and deriving velocities and surface changes of glaciers and ice sheets. An absolute prerequisite for successful fusion is a rigorous co-registration of the sensors involved. We establish a common 3-D reference frame by using sensor invariant features. Such features are caused by the same object space phenomena and are extracted in multiple steps from the individual sensors. After extracting, segmenting and grouping the features into more abstract entities, we discuss ways on how to automatically establish correspondences. This is followed by a brief description of rigorous mathematical models suitable to deal with linear and area features. In contrast to traditional, point-based registration methods, lineal and areal features lend themselves to a more robust and more accurate registration. More important, the chances to automate the registration process increases significantly. The result of the co-registration of the sensors is a unique transformation between the individual sensors and the object space. This makes spatial reasoning of extracted information more versatile; reasoning can be performed in sensor space or in 3-D space where domain knowledge about features and objects constrains reasoning processes, reduces the search space, and helps to make the problem well-posed. We demonstrate the feasibility of the proposed multisensor fusion approach

  6. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  7. Mitochondrial fusion and inheritance of the mitochondrial genome.

    PubMed

    Takano, Hiroyoshi; Onoue, Kenta; Kawano, Shigeyuki

    2010-03-01

    Although maternal or uniparental inheritance of mitochondrial genomes is a general rule, biparental inheritance is sometimes observed in protists and fungi,including yeasts. In yeast, recombination occurs between the mitochondrial genomes inherited from both parents.Mitochondrial fusion observed in yeast zygotes is thought to set up a space for DNA recombination. In the last decade,a universal mitochondrial fusion mechanism has been uncovered, using yeast as a model. On the other hand, an alternative mitochondrial fusion mechanism has been identified in the true slime mold Physarum polycephalum.A specific mitochondrial plasmid, mF, has been detected as the genetic material that causes mitochondrial fusion in P. polycephalum. Without mF, fusion of the mitochondria is not observed throughout the life cycle, suggesting that Physarum has no constitutive mitochondrial fusion mechanism.Conversely, mitochondria fuse in zygotes and during sporulation with mF. The complete mF sequence suggests that one gene, ORF640, encodes a fusogen for Physarum mitochondria. Although in general, mitochondria are inherited uniparentally, biparental inheritance occurs with specific sexual crossing in P. polycephalum.An analysis of the transmission of mitochondrial genomes has shown that recombinations between two parental mitochondrial genomes require mitochondrial fusion,mediated by mF. Physarum is a unique organism for studying mitochondrial fusion. PMID:20196232

  8. Latino College Completion: Georgia

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  9. Latino College Completion: Virginia

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  10. Latino College Completion: Oklahoma

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  11. Latino College Completion: Washington

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  12. Latino College Completion: Wisconsin

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  13. Latino College Completion: Wyoming

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  14. Latino College Completion: Utah

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  15. Latino College Completion: Massachusetts

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  16. Latino College Completion: Kansas

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  17. Latino College Completion: Colorado

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  18. Latino College Completion: Alabama

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  19. Latino College Completion: Arizona

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  20. Latino College Completion: Michigan

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  1. Latino College Completion: Illinois

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  2. Latino College Completion: Minnesota

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  3. Latino College Completion: Maine

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  4. Latino College Completion: Connecticut

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  5. Latino College Completion: Indiana

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  6. Latino College Completion: Maryland

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  7. Latino College Completion: Arkansas

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  8. Latino College Completion: Delaware

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  9. Latino College Completion: Alaska

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  10. Latino College Completion: Kentucky

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  11. Latino College Completion: Mississippi

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  12. Latino College Completion: Nevada

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  13. Latino College Completion: California

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  14. Latino College Completion: Missouri

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  15. Latino College Completion: Nebraska

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  16. Latino College Completion: Vermont

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  17. Latino College Completion: Montana

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  18. Latino College Completion: Florida

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  19. Latino College Completion: Oregon

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  20. Latino College Completion: Louisiana

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  1. Latino College Completion: Ohio

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  2. Latino College Completion: Hawaii

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  3. Latino College Completion: Idaho

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  4. Latino College Completion: Iowa

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  5. Latino College Completion: Tennessee

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  6. Latino College Completion: Pennsylvania

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  7. Classical versus quantum completeness

    NASA Astrophysics Data System (ADS)

    Hofmann, Stefan; Schneider, Marc

    2015-06-01

    The notion of quantum-mechanical completeness is adapted to situations where the only adequate description is in terms of quantum field theory in curved space-times. It is then shown that Schwarzschild black holes, although geodesically incomplete, are quantum complete.

  8. Latino College Completion: Texas

    ERIC Educational Resources Information Center

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  9. A review of pulse fusion propulsion

    NASA Astrophysics Data System (ADS)

    Cassenti, Brice N.

    2002-01-01

    During the last forty years there has been considerable interest in both internal and external pulse propulsion systems. Over this time the nuclear devices being considered have grown considerably smaller than those initially examined. Now pellets are normally in the range from 15 cm down to 2 cm in diameter, and fusion devices are generally preferred. High energy density triggers (such as lasers, particle beams or antiprotons) have been considered for detonating the fusion fuel. When antiprotons are considered it is more efficient to annihilate the antiprotons in a fissionable material, and then use the energy from the fission reaction to drive the fusion reaction in the pellet, than to use the annihilation energy directly. Finally, fissionable material can be used to boost the performance of a fusion system. The early concepts, which used critical mass devices, do not satisfy the ban on nuclear weapons in space, and are only rarely considered today. Concepts based on inertial confinement fusion are heavier than those that use antiprotons for the trigger since the mass associated with the lasers, or particle beams and their power supplies are considerably heavier than the traps used for antiprotons. Hence, from a performance, and even a political, point of view the antiproton-triggered approach is the most desirable, but it also requires more development. Not only is the trigger lighter but an external pulse propulsion rocket does not necessarily need radiators to reject excess heat and, hence, can be even lighter. Propulsion systems based on critical mass devices are clearly feasible, so the primary problem is to reduce the size of the explosive devices so that a critical mass is not required. If pulse nuclear fusion propulsion can become a reality then the performance is enough to complete manned missions to the inner planets in weeks and the outer planets in months. .

  10. Lateral Lumbar Interbody Fusion

    PubMed Central

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

    2015-01-01

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

  11. Lateral Lumbar Interbody Fusion.

    PubMed

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

    2015-12-01

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

  12. Fusion, magnetic confinement

    SciTech Connect

    Berk, H.L.

    1992-08-06

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

  13. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  14. Fusion of the weakly bound projectile {sup 9}Be with {sup 89}Y

    SciTech Connect

    Palshetkar, C. S.; Santra, S.; Chatterjee, A.; Ramachandran, K.; Pandit, S. K.; Mahata, K.; Shrivastava, A.; Thakur, Shital; Parkar, V. V.; Nanal, V.

    2010-10-15

    The excitation function for the complete fusion of {sup 9}Be+{sup 89}Y has been measured at near-barrier energies, and the barrier distribution has been extracted from the fusion data. Coupled-channels calculations have been carried out to understand the effect of coupling of both the projectile and target excitations on the above quantities. The complete fusion cross sections, especially at above-barrier energies, have been found to be suppressed by (20{+-}5)% compared to the ones predicted by the coupled-channels calculations that do not include the couplings to the projectile continuum, indicating the loss of flux from the entrance channel before fusion. This conclusion is also supported by a considerable incomplete fusion cross section observed for this system. Fusion measurements for two more systems have been carried out, namely, for {sup 4}He+{sup 93}Nb and {sup 12}C+{sup 89}Y, which involve tightly bound projectiles and form compound nuclei nearby to that formed in {sup 9}Be+{sup 89}Y fusion. Comparison of the fusion data obtained for all three systems further confirms the suppression of complete fusion in the {sup 9}Be+{sup 89}Y system. Systematics of the suppression factor observed for {sup 9}Be induced fusion in different mass targets is discussed.

  15. Exocytotic fusion pore stability and topological defects in the membrane with orientational degree of ordering.

    PubMed

    Jesenek, Dalija; Perutková, Sárka; Kralj-Iglič, Veronika; Kralj, Samo; Iglič, Aleš

    2012-01-01

    Regulated exocytosis is a process that strongly depends on the formation and stability of the fusion pore. It was indicated experimentally and theoretically that narrow and highly curved fusion pore may be stabilized by accumulation of anisotropic membrane components possessing orientational ordering. On the other hand, narrow fusion pore may also undergo repetitive opening and closing, disruption in the so called kiss and run process or become completely opened in the process of full fusion of the vesicle with the membrane. In this paper we attempt to elucidate the subtle interplay between the stabilizing and destabilizing processes in the fusion neck. A possible physical mechanism which may lead to disruption of the stable fusion pore or complete fusion of the vesicle with the membrane is discussed. It is indicated that topologically driven defects of the in-plane orientational membrane ordering in the region of the fusion pore may disrupt the fusion. Alternatively, it may facilitate repetitive opening and closing of the fusion pore or induce full fusion of the vesicle with the target membrane. PMID:22541648

  16. Ceramics for fusion applications

    SciTech Connect

    Clinard, F.W. Jr.

    1986-01-01

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

  17. Colliding Beam Fusion Reactors

    NASA Astrophysics Data System (ADS)

    Rostoker, Norman; Qerushi, Artan; Binderbauer, Michl

    2003-06-01

    The recirculating power for virtually all types of fusion reactors has previously been calculated [1] with the Fokker-Planck equation. The reactors involve non-Maxwellian plasmas. The calculations are generic in that they do not relate to specific confinement devices. In all cases except for a Tokamak with D-T fuel the recirculating power was found to exceed the fusion power by a large factor. In this paper we criticize the generality claimed for this calculation. The ratio of circulating power to fusion power is calculated for the Colliding Beam Reactor with fuels D-T, D-He3 and p-B11. The results are respectively, 0.070, 0.141 and 0.493.

  18. Peaceful Uses of Fusion

    DOE R&D Accomplishments Database

    Teller, E.

    1958-07-03

    Applications of thermonuclear energy for peaceful and constructive purposes are surveyed. Developments and problems in the release and control of fusion energy are reviewed. It is pointed out that the future of thermonuclear power reactors will depend upon the construction of a machine that produces more electric energy than it consumes. The fuel for thermonuclear reactors is cheap and practically inexhaustible. Thermonuclear reactors produce less dangerous radioactive materials than fission reactors and, when once brought under control, are not as likely to be subject to dangerous excursions. The interaction of the hot plasma with magnetic fields opens the way for the direct production of electricity. It is possible that explosive fusion energy released underground may be harnessed for the production of electricity before the same feat is accomplished in controlled fusion processes. Applications of underground detonations of fission devices in mining and for the enhancement of oil flow in large low-specific-yield formations are also suggested.

  19. Simulation of Fusion Plasmas

    ScienceCinema

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

    2010-01-08

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

  20. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-04-04

    A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

  1. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-01-01

    A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

  2. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

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

  3. DD fusion in crystals

    SciTech Connect

    Tsyganov, E. N.

    2010-12-15

    The article discusses the mechanism of DD {sup {yields} 4}He fusion and so-called nonradiative thermalization of the reaction in crystals. The dynamics of this process is considered. The assumption that the decay time of the compound nucleus depends on its excitation energy makes experiments in crystals compatible with the acceleration data.We consider the processes in the crystals that increase the intensity ofDD fusion in comparison to the amorphous media, and the yield of the reaction is estimated.

  4. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  5. Fusion welding process

    DOEpatents

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  6. Atomic data for fusion

    SciTech Connect

    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.

  7. Multisensor data fusion algorithm development

    SciTech Connect

    Yocky, D.A.; Chadwick, M.D.; Goudy, S.P.; Johnson, D.K.

    1995-12-01

    This report presents a two-year LDRD research effort into multisensor data fusion. We approached the problem by addressing the available types of data, preprocessing that data, and developing fusion algorithms using that data. The report reflects these three distinct areas. First, the possible data sets for fusion are identified. Second, automated registration techniques for imagery data are analyzed. Third, two fusion techniques are presented. The first fusion algorithm is based on the two-dimensional discrete wavelet transform. Using test images, the wavelet algorithm is compared against intensity modulation and intensity-hue-saturation image fusion algorithms that are available in commercial software. The wavelet approach outperforms the other two fusion techniques by preserving spectral/spatial information more precisely. The wavelet fusion algorithm was also applied to Landsat Thematic Mapper and SPOT panchromatic imagery data. The second algorithm is based on a linear-regression technique. We analyzed the technique using the same Landsat and SPOT data.

  8. Fusion technology status and requirements

    SciTech Connect

    Thomassen, K.I.

    1982-01-26

    This paper summarizes the status of fusion technology and discusses the requirements to be met in order to build a demonstration fusion plant. Strategies and programmatic considerations in pursuing engineering feasibility are also outlined.

  9. Human-Centered Fusion Framework

    SciTech Connect

    Posse, Christian; White, Amanda M.; Beagley, Nathaniel

    2007-05-16

    In recent years the benefits of fusing signatures extracted from large amounts of distributed and/or heterogeneous data sources have been largely documented in various problems ranging from biological protein function prediction to cyberspace monitoring. In spite of significant progress in information fusion research, there is still no formal theoretical framework for defining various types of information fusion systems, defining and analyzing relations among such types, and designing information fusion systems using a formal method approach. Consequently, fusion systems are often poorly understood, are less than optimal, and/or do not suit user needs. To start addressing these issues, we outline a formal humancentered fusion framework for reasoning about fusion strategies. Our approach relies on a new taxonomy for fusion strategies, an alternative definition of information fusion in terms of parameterized paths in signature related spaces, an algorithmic formalization of fusion strategies and a library of numeric and dynamic visual tools measuring the impact as well as the impact behavior of fusion strategies. Using a real case of intelligence analysis we demonstrate that the proposed framework enables end users to rapidly 1) develop and implement alternative fusion strategies, 2) understand the impact of each strategy, 3) compare the various strategies, and 4) perform the above steps without having to know the mathematical foundations of the framework. We also demonstrate that the human impact on a fusion system is critical in the sense that small changes in strategies do not necessarily correspond to small changes in results.

  10. Status of inertial fusion

    NASA Astrophysics Data System (ADS)

    Keefe, D.

    1987-04-01

    The technology advancement to high-power beams has also given birth to new technologies. That class of Free Electron Lasers that employs RF linacs, synchrotrons, and storage rings - although the use of the tools of High Energy Physics (HEP) - was developed well behind the kinetic energy frontier. The induction linac, however, is something of an exception; it was born directly from the needs of the magnetic fusion program, and was not motivated by a high-energy physics application. The heavy-ion approach to inertial fusion starts with picking from the rich menu of accelerator technologies those that have, ab initio, the essential ingredients needed for a power plant driver: multigap acceleration - which leads to reliability/lifetime; electrical efficiency; repetition rate; and beams that can be reliably focused over a suitably long distance. The report describes the programs underway in Heavy Ion Fusion Accelerator Research as well as listing expected advances in driver, target, and beam quality areas in the inertial fusion power program.