Science.gov

Sample records for fusion reaction products

  1. 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.

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

    SciTech Connect

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

    2013-03-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    PubMed

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

    2013-03-01

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

  5. Production cross sections of superheavy elements Z =119 and 120 in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Zhu, Long; Xie, Wen-Jie; Zhang, Feng-Shou

    2014-02-01

    The production cross sections of superheavy nuclei in hot fusion reactions are investigated systematically. In hot fusion reactions, the capture cross section can be obtained by calculating the weighted average of the transmission probability for different orientations of deformed colliding nuclei. An analytical formula for calculating the value of the fusion probability is proposed, which is suitable for both hot and cold fusion reactions. The orientation effects are considered empirically in calculating the fusion probability. The method proposed in the present work reproduces the measured evaporation residue (ER) cross sections in hot fusion reactions acceptably well. The formula also gives reasonable results for fusion probability in cold fusion reactions. Using this method the evaporation residue cross sections for synthesizing Z =119 and 120 are predicted. It is found that for hot fusion reaction's larger maximal ER cross section of the 4n channel corresponds to lower optimal incident energy.

  6. Possibilities of production of transfermium nuclei in complete fusion reactions with radioactive beams

    NASA Astrophysics Data System (ADS)

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

    2017-07-01

    The possibilities of direct production of new isotopes of transfermium nuclei 261,263,264No, 264Lr263, 263,264,266,268Rf, 265Db264, and 267,268,270,272Sg are studied in various asymmetric hot fusion-evaporation reactions with radioactive beams. The optimal reaction partners and conditions for the synthesis of new isotopes are suggested. The products of the suggested reactions can fill a gap of unknown isotopes between the isotopes of heaviest nuclei obtained in the x n evaporation channels of the cold and hot complete fusion reactions with the stable beams.

  7. Nuclear reaction products that would appear if substantial cold fusion occurred

    SciTech Connect

    Mueller, D.; Grisham, L.R. . Plasma Physics Lab.)

    1989-11-01

    This paper reports on recent claims of net energy production by cold fusion that have prompted an examination of all the positive Q value, two-body nuclear reactions that might result from the fusion of any of the isotopes in the apparatus used by Fleischmann and Pons. Any energy production that may result from cold fusion would be accompanied by copious production of nuclear reaction products (on the order of 10{sup 13}/s). Furthermore, the elementary properties of the alpha particle at the deuteron + deuteron threshold are discussed. An important property of the alpha at this high excitation is its nearly prompt (10{sup {minus}20} s) decay by particle emission to {sup 3}He + n or triton + proton.

  8. Near threshold two meson production in hardonic fusion reactions

    NASA Astrophysics Data System (ADS)

    Jahn, Rainer

    1991-04-01

    An approved and funded exclusive COSY experiment is presented, which focuses on near threshold two meson production via the reactions p+d→3 He+π+π- and p+d→3 He+K+K-. It takes advantage of the high quality of the cooled external COSY beam and the existing spectrometer BIG KARL. The setup consists of a vertex wall and a scintillator cylinder and endcap covering a 4π solid angle. The large efficiency and high resolution of this detection method will yield precision data on the low energy (T<50 MeV) meson-meson interaction and probe into questions like the ABC-effect and KḲ molecule. The detector further allows a measurement of possible radiative φ (1020) decay, which will directly probe the strange quark content of the f0(975). Existing inclusive data as well as first results of a very recent `semi-exclusive' experiment performed at SATURNE will be also be presented.

  9. Study of Complete Fusion Reactions Leading to the Production of Heavy and Superheavy Nuclei

    SciTech Connect

    Roman N. Sagaidak

    1999-12-31

    Cross section values for heavy evaporation residues (ER) produced in complete fusion reactions induced by heavy ions on spherical and deformed target nuclei are analyzed in the framework of barrier penetration and statistical model approximations. For the reactions leading to Rn-Pa nuclei, a strong influence of the entrance channel on the measured cross section values is observed for nearly symmetric projectile-target combinations. In order to reproduce the observed excitation functions in such combinations we had to introduce the quantity of fusion probability. Considering the asymmetric reactions leading to the heaviest nuclei we also had to use the fusion probability to reproduce the cross section values obtained for cold fusion reactions induced by {sup 50}Ti and heavier projectiles on the Pb and Bi target nuclei, and also the values obtained for hot fusion reactions induced by {sup 34}S on actinide target nuclei. The scaling of fusion probabilities derived for both the reactions allowed us to predict the values of cross sections for superheavy elements (SHE) produced in the {sup 48}Ca induced reactions on actinide target nuclei and in the cold fusion reactions induced by the Zn and heavier projectiles.

  10. Study of complete fusion reactions leading to the production of heavy and superheavy nuclei

    SciTech Connect

    Sagaidak, Roman N.

    1999-11-16

    Cross section values for heavy evaporation residues (ER) produced in complete fusion reactions induced by heavy ions on spherical and deformed target nuclei are analyzed in the framework of barrier penetration and statistical model approximations. For the reactions leading to Rn-Pa nuclei, a strong influence of the entrance channel on the measured cross section values is observed for nearly symmetric projectile-target combinations. In order to reproduce the observed excitation functions in such combinations we had to introduce the quantity of fusion probability. Considering the asymmetric reactions leading to the heaviest nuclei we also had to use the fusion probability to reproduce the cross section values obtained for cold fusion reactions induced by {sup 50}Ti and heavier projectiles on the Pb and Bi target nuclei, and also the values obtained for hot fusion reactions induced by {sup 34}S on actinide target nuclei. The scaling of fusion probabilities derived for both the reactions allowed us to predict the values of cross sections for superheavy elements (SHE) produced in the {sup 48}Ca induced reactions on actinide target nuclei and in the cold fusion reactions induced by the Zn and heavier projectiles.

  11. 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.

  12. Effect of fusion reaction products heating on the volume ignition of DT and D3He fuel pellets

    NASA Astrophysics Data System (ADS)

    Khoda-Bakhsh, R.

    1996-05-01

    Laser fusion simulations are carried out for the DT and D-3He pellets by using a hydrodynamic code including heating from all charged reaction products and neutron. It is shown that, the inclusion of the side reactions and heating from all reactions products in the fuel pellets has an appreciable affect on the plasma temperature, the ICF drive energy requirement, fusion gain and the ignition conditions. The total input energy is decreased, the burn efficiency and total gain are increased compared to the results of simple volume ignition calculations.

  13. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-01-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  14. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-03-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  15. Fusion-Evaporation Cross Sections in Reactions Leading to Production of Super-Heavy Nuclei

    SciTech Connect

    Siwek-Wilczynska, K.; Skwira-Chalot, I.; Wilczynski, J.

    2006-08-14

    Fusion-evaporation cross sections were calculated for the 48Ca+204-208Pb and 50Ti+206,208Pb reactions and compared with the existing experimental data of the Dubna and GSI groups. The survival probabilities of the compound Z 102 and Z = 104 nuclei formed in these reactions were calculated using a Monte Carlo program based on the conventional Bohr-Wheeler theory of fission and statistical model of particle evaporation with Reisdorf-Ignatyuk prescription for the level densities and Strutinsky shell corrections of Moeller et al. 'Empirical' magnitudes of the dynamical hindrance of fusion have been deduced for these reactions.

  16. Production of proton-rich nuclei around Z = 84-90 in fusion-evaporation reactions

    NASA Astrophysics Data System (ADS)

    Chen, Peng-Hui; Feng, Zhao-Qing; Niu, Fei; Guo, Ya-Fei; Zhang, Hong-Fei; Li, Jun-Qing; Jin, Gen-Ming

    2017-05-01

    Within the framework of the dinuclear system model, production cross sections of proton-rich nuclei with charged numbers of Z = 84-90 are investigated systematically. Possible combinations with the 28Si, 32S, 40Ar bombarding the target nuclides 165Ho, 169Tm, 170-174Yb, 175,176Lu, 174, 176-180Hf and 181Ta are analyzed thoroughly. The optimal excitation energies and evaporation channels are proposed to produce the proton-rich nuclei. The systems are feasible to be constructed in experiments. It is found that the neutron shell closure of N = 126 is of importance during the evaporation of neutrons. The experimental excitation functions in the 40Ar induced reactions can be nicely reproduced. The charged particle evaporation is comparable with neutrons in cooling the excited proton-rich nuclei, in particular for the channels with α and proton evaporation. The production cross section increases with the mass asymmetry of colliding systems because of the decrease of the inner fusion barrier. The channels with pure neutron evaporation depend on the isotopic targets. But it is different for the channels with charged particles and more sensitive to the odd-even effect.

  17. Product PCNPsurv or the "reduced" evaporation residue cross section σER/σfusion for "hot" fusion reactions studied with the dynamical cluster-decay model

    NASA Astrophysics Data System (ADS)

    Chopra, Sahila; Kaur, Arshdeep; Hemdeep, Gupta, Raj K.

    2016-04-01

    The product PCNPsurv of compound nucleus (CN) fusion probability PCN and survival probability Psurv is calculated to determine the reduced evaporation residue cross section σER/σfusion , denoted σERreduced, with (total) fusion cross section σfusion given as a sum of CN-formation cross section σCN and non-CN cross section σnCN for each reaction, where σCN is the sum of evaporation residue cross section σER and fusion-fission cross section σff and σnCN, if not measured, is estimated empirically as the difference between measured and calculated σfusion. Our calculations of PCN and Psurv, based on the dynamical cluster-decay model, were successfully made for some 17 "hot" fusion reactions, forming different CN of mass numbers ACN˜100 -300 , with deformations of nuclei up to hexadecapole deformations and "compact" orientations for both coplanar (Φc=0∘ ) and noncoplanar (Φc≠0∘ ) configurations, using various different nuclear interaction potentials. Interesting variations of σERreduced with CN excitation energy E*, fissility parameter χ , CN mass ACN, and Coulomb parameter Z1Z2 show that, independent of entrance channel, different isotopes of CN, and nuclear interaction potentials used, the dominant quantity in the product is Psurv, which classifies all the studied CN into three groups of weakly fissioning, radioactive, and strongly fissioning superheavy nuclei, with relative magnitudes of σERreduced˜1 , ˜10-6 , and ˜10-11 , which, like for PCN, get further grouped in two dependencies of (i) weakly fissioning and strongly fissioning superheavy nuclei decreasing with increasing E* and (ii) radioactive nuclei increasing with increasing E*.

  18. 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.

  19. Characterization of Discontinuous Coarsening Reaction Products in INCONEL® Alloy 740H® Fusion Welds

    NASA Astrophysics Data System (ADS)

    Bechetti, Daniel H.; Dupont, John N.; Watanabe, Masashi; de Barbadillo, John J.

    2017-04-01

    Characterization of γ' coarsened zones (CZs) in alloy 740H fusion welds via a variety of electron microscopy techniques was conducted. The effects of solute partitioning during nonequilibrium solidification on the amount of strengthening precipitates along the grain boundaries were evaluated via electron-probe microanalysis and scanning electron microscopy. Electron backscatter diffraction was used to present evidence for the preferential growth of CZs toward regions of lower γ' content, even if growth in that direction increases grain boundary area. Scanning electron microscopy and image analysis were used to quantify the propensity for CZs to develop along certain segments of the grain boundaries, as governed by the local variations in γ' content. Scanning transmission electron microscopy with X-ray energy-dispersive spectrometry (XEDS) was used to assess the compositions of the matrix and precipitate phases within the CZs and to quantify the segregation of alloying components to the reaction front. Thermodynamic and kinetic modeling were used to compare calculated and experimental compositions. The work presented here provides new insight into the progression of the discontinuous coarsening (DC) reaction in a complex engineering alloy.

  20. Characterization of Discontinuous Coarsening Reaction Products in INCONEL® Alloy 740H® Fusion Welds

    NASA Astrophysics Data System (ADS)

    Bechetti, Daniel H.; Dupont, John N.; Watanabe, Masashi; de Barbadillo, John J.

    2017-02-01

    Characterization of γ' coarsened zones (CZs) in alloy 740H fusion welds via a variety of electron microscopy techniques was conducted. The effects of solute partitioning during nonequilibrium solidification on the amount of strengthening precipitates along the grain boundaries were evaluated via electron-probe microanalysis and scanning electron microscopy. Electron backscatter diffraction was used to present evidence for the preferential growth of CZs toward regions of lower γ' content, even if growth in that direction increases grain boundary area. Scanning electron microscopy and image analysis were used to quantify the propensity for CZs to develop along certain segments of the grain boundaries, as governed by the local variations in γ' content. Scanning transmission electron microscopy with X-ray energy-dispersive spectrometry (XEDS) was used to assess the compositions of the matrix and precipitate phases within the CZs and to quantify the segregation of alloying components to the reaction front. Thermodynamic and kinetic modeling were used to compare calculated and experimental compositions. The work presented here provides new insight into the progression of the discontinuous coarsening (DC) reaction in a complex engineering alloy.

  1. Excitation functions for the production of superheavy nuclei in cold fusion reactions

    SciTech Connect

    Smolanczuk, Robert

    2000-01-01

    Excitation energy dependence of the cross sections of the reactions {sup 208}Pb{sub 126}({sup 50}Ti{sub 28},1n){sup 257}Rf{sub 153} and {sup 208}Pb{sub 126}({sup 58}Fe{sub 32},1n){sup 265}Hs{sub 157} is calculated and compared with the experimental data measured at GSI-Darmstadt. Such a dependence is also calculated for the reaction {sup 208}Pb{sub 126}({sup 86}Kr{sub 50},1n){sup 293}118{sub 175} reported recently by the Berkeley group, and for reactions which may lead to the synthesis of element 119 and production of its odd-Z descendants. Recommendations for future experiments based on the present study are presented. (c) 1999 The American Physical Society.

  2. PRODUCTION OF {sup 9}Be THROUGH THE {alpha}-FUSION REACTION OF METAL-POOR COSMIC RAYS AND STELLAR FLARES

    SciTech Connect

    Kusakabe, Motohiko; Kawasaki, Masahiro E-mail: kawasaki@icrr.u-tokyo.ac.jp

    2013-04-10

    Spectroscopic observations of metal-poor stars have indicated possible {sup 6}Li abundances that are much larger than the primordial abundance predicted in the standard big bang nucleosynthesis model. Possible mechanisms of {sup 6}Li production in metal-poor stars include pregalactic and cosmological cosmic-ray (CR) nucleosynthesis and nucleosynthesis by flare-accelerated nuclides. We study {sup 9}Be production via two-step {alpha}-fusion reactions of CR or flare-accelerated {sup 3,4}He through {sup 6}He and {sup 6,7}Li, in pregalactic structure, intergalactic medium, and stellar surfaces. We solve transfer equations of CR or flare particles and calculate nuclear yields of {sup 6}He, {sup 6,7}Li, and {sup 9}Be taking account of probabilities of processing {sup 6}He and {sup 6,7}Li into {sup 9}Be via fusions with {alpha} particles. Yield ratios, i.e., {sup 9}Be/{sup 6}Li, are then calculated for the CR and flare nucleosynthesis models. We suggest that the future observations of {sup 9}Be in metal-poor stars may find enhanced abundances originating from metal-poor CR or flare activities.

  3. Fusion reactions at low energy

    SciTech Connect

    Beckerman, M.

    1985-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  5. Stockpile tritium production from fusion

    SciTech Connect

    Lokke, W.A.; Fowler, T.K.

    1986-03-21

    A fusion breeder holds the promise of a new capability - ''dialable'' reserve capacity at little additional cost - that offers stockpile planners a new way to deal with today's uncertainties in forecasting long range needs. Though still in the research stage, fusion can be developed in time to meet future military requirements. Much of the necessary technology will be developed by the ongoing magnetic fusion energy program. However, a specific program to develop the nuclear technology required for materials production is needed if fusion is to become a viable option for a new production complex around the turn of the century.

  6. Formation of superheavy nuclei in cold fusion reactions

    SciTech Connect

    Feng Zhaoqing; Jin Genming; Li Junqing; Scheid, Werner

    2007-10-15

    Within the concept of the dinuclear system (DNS), a dynamical model is proposed for describing the formation of superheavy nuclei in complete fusion reactions by incorporating the coupling of the relative motion to the nucleon transfer process. The capture of two heavy colliding nuclei, the formation of the compound nucleus, and the de-excitation process are calculated by using an empirical coupled channel model, solving a master equation numerically and applying statistical theory, respectively. Evaporation residue excitation functions in cold fusion reactions are investigated systematically and compared with available experimental data. Maximal production cross sections of superheavy nuclei in cold fusion reactions with stable neutron-rich projectiles are obtained. Isotopic trends in the production of the superheavy elements Z=110, 112, 114, 116, 118, and 120 are analyzed systematically. Optimal combinations and the corresponding excitation energies are proposed.

  7. 28C fusion reactions at high energies

    NASA Astrophysics Data System (ADS)

    Kim, B. T.; Cha, D.

    1987-04-01

    We present a model based on the direct reaction concept which is able to describe the fusion cross section consistently throughout the entire range of the measured energies from the sub-barrier region to the very high energies where the cross section decreases linearly as the inverse of the center of mass energy. The model is applied to the fusion reaction of 28Si with 12C where Harmon et al. measured the cross section at energies up to three times the Coulomb barrier.

  8. Measurements of fusion reactions from a Tokamak plasma

    NASA Astrophysics Data System (ADS)

    Chrien, R. E.

    1981-11-01

    Tokamak fusion reaction diagnostics were extended to include measurements of d-t, dp-3He, and d-d (proton branch) reactions. The confinement and slowing down of 1 MeV d-d tritons were studied y measuring d-t meutrons. The first charged fusion products to be detected in a Tokamak were the 3 MeV d-d and 14.7 MeV d- 3He protons. Beam-target d-3He reactions were measured during deuterium beam injection to study the transport and vessel retention of helium. Large d-3He reaction rates were produced by ion cyclotron heating of a 3He minority in a deuterium plasma. Measurements of the reaction rate, energy spectrum, and decay time indicate that the reactions are produced by 200 - 400 keV3He ions. Sawtooth and m = 2 oscillations in the proton emission were observed.

  9. Nucleus-nucleus cold fusion reactions analyzed with the l-dependent ``fusion by diffusion'' model

    NASA Astrophysics Data System (ADS)

    Cap, T.; Siwek-Wilczyńska, K.; Wilczyński, J.

    2011-05-01

    We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section σcap(l), the fusion probability Pfus(l), and the survival probability Psurv(l). The fusion hindrance factor, the inverse of Pfus(l), is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The l dependence of Pfus(l) results from the l-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1n reaction is determined by the Q value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

  10. Fusion Reaction Rate in an Inhomogeneous Plasma

    SciTech Connect

    S. Son; N.J. Fisch

    2004-09-03

    The local fusion rate, obtained from the assumption that the distribution is a local Maxwellian, is inaccurate if mean-free-paths of fusing particles are not sufficiently small compared with the inhomogeneity length of the plasma. We calculate the first order correction of P0 in terms of the small spatial gradient and obtain a non-local modification of P(sub)0 in a shock region when the gradient is not small. Use is made of the fact that the fusion reaction cross section has a relatively sharp peak as a function of energy.

  11. 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.

  12. From nucleons to nuclei to fusion reactions

    NASA Astrophysics Data System (ADS)

    Quaglioni, S.; Navrátil, P.; Roth, R.; Horiuchi, W.

    2012-12-01

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  13. From Nucleons To Nuclei To Fusion Reactions

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R; Horiuchi, W

    2012-02-15

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  14. Ab initio calculations of light-ion fusion reactions

    SciTech Connect

    Hupin, G.; Quaglioni, S.; Navratil, P.

    2012-10-20

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches. The ab initio No-Core Shell Model/Resonating-Group Method (NCSM/RGM) complements a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach is capable of describing simultaneously both bound and scattering states in light nuclei. Recent applications to light nuclei scattering and fusion reactions relevant to energy production in stars and Earth based fusion facilities, such as the deuterium-{sup 3}He fusion, are presented. Progress toward the inclusion of the three nucleon force into the formalism is outlined.

  15. Neutron suppression in polarized dd fusion reaction

    NASA Astrophysics Data System (ADS)

    Zhang, J. S.; Liu, K. F.; Shuy, G. W.

    1999-11-01

    We report a model-independent partial-wave analysis of polarized dd fusion reactions at low energies. The radial transition amplitudes, designated by the central, spin-orbit, and tensor forces, are determined by fitting angular distributions of the tensor and vector analyzing powers AXZ(θ), AZZ(θ), AXX-YY(θ), and AY(θ), and the unpolarized cross section σ0(θ). The polarized fusion cross section σ1,1(θ) is then predicted from these radial transition amplitudes. We stress that this is feasible only when these amplitudes are separated according to the tensor rank of the interaction. This study includes the D-state components of the deuteron, triton, and 3He, and the partial-wave expansion is done up to the d wave for both the entrance and exit channels. Experimental data at Elab=30, 50, 70, and 90 keV for the d(d,p)t reaction are very well fitted with this method. It is found that the ratio of polarized to unpolarized cross sections is about 86% at 30 keV and goes down to 22% at 90 keV. The implication of the suppression of a polarized dd fusion reaction is discussed in the context of the neutron-lean fusion reactor with polarized D-3He fuel. It turns out that the important range of energy for suppressing the d(d,p)t and d(d,n)3He reactions at the plasma temperature T=60 keV is Ed=80-600 keV. More experimental data are needed in this range to make a detailed study of the neutron suppression.

  16. Comparative Investigation of Fusion Reactions for Space Propulsion Applications

    NASA Astrophysics Data System (ADS)

    Petkow, Dejan; Herdrich, Georg; Laufer, Rene; Gabrielli, Roland; Zeile, Oliver

    A space propulsion system based on the acceleration of fusion ash is discussed by use of the energy balance equation and a hypothetic ash extraction and acceleration system. The fusion reactions D-T, D-3He, p-11B and 3He-3He are investigated under the condition of thermal generation of high energy ions and equal plasma system conditions in terms of Ti/Te relation and plasma beta. External plasma heating is defined by an equal efficiency concerning thermal energy conversion and energy transfer back into the plasma. There is no additional external heating applied to the fusion system. Power losses are based on neutrons, bremsstrahlung, synchrotron radiation and convection. We compare the plasma pressures, volumetric power densities, magnetic field strengths, heat waste, exhaust velocities and thrust density levels depending on the temperature and the hot ion mode. We show that, based on the fusion products, the exhaust velocity may reach several percent of speed of light in the case of 3He-3He. The temperature driven radiation losses of the 3He-3He reaction puts the purely aneutronic property into perspective. The mass flow rate densities of the considered fusion products are very low leading to very low thrust power densities. Considering the supposed system masses of a fusion based space vessel the thrust density levels are negligible and reach the order of 1 N/m3 near the optimum in the case of 3He-3He. We conclude that a propulsion system based on the acceleration of fusion products or ash is unfeasible for typical manned missions e.g. to Mars.

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

    SciTech Connect

    Bush, R.T. )

    1992-09-01

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

  18. Nucleus-nucleus cold fusion reactions analyzed with the l-dependent 'fusion by diffusion' model

    SciTech Connect

    Cap, T.; Siwek-Wilczynska, K.; Wilczynski, J.

    2011-05-15

    We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section {sigma}{sub cap}(l), the fusion probability P{sub fus}(l), and the survival probability P{sub surv}(l). The fusion hindrance factor, the inverse of P{sub fus}(l), is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The l dependence of P{sub fus}(l) results from the l-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1n reaction is determined by the Q value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

  19. Barrier Distributions for Cold-Fusion Reactions

    SciTech Connect

    Ikezoe, Hiroshi; Mitsuoka, Shin-ichi; Nishio, Katsuhisa; Tsuruta, Kaoru; Watanabe, Yutaka; Jeong, Sunchan; Satou, Ken-ichiro

    2006-08-14

    Coulomb barrier distributions for the capture process in the cold fusion reactions for 48Ti, 54Cr, 56Fe, 64Ni, 70Zn projectiles incident on 208Pb target are obtained by the measurement of the quasi-elastic scattering cross sections at backward angles. The obtained barrier distributions are compared with the result of a coupled-channels calculation. It is found that the barrier distributions are well reproduced by the calculation taking account of the coupling of one phonon of the quadrupole vibration for these projectile nuclei and two phonons of the octupole vibration for 208Pb.

  20. Synthesis of the heaviest nuclei in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Münzenberg, G.; Morita, K.

    2015-12-01

    Cold fusion of heavy ions paved the way to superheavy elements. It was proposed by Yu.Ts. Oganessian more than forty years ago in 1974 [1,2]. First experiments were carried out at JINR Dubna, starting with the reaction 40Ar + 208Pb → 248Fm* where several hundreds to thousand atoms were produced on one day. The large production rate indicating an enhancement of the fusion cross section, especially for the evaporation of two or three neutrons, proved the concept of cold-fusion with the use of the doubly magic nucleus 208Pb as a target. The Dubna experiments were extended to the transactinide region beyond rutherfordium. The breakthrough came with the separation in-flight. Two different approaches were used: kinematic separation with the velocity filter SHIP [3] at GSI Darmstadt, and with the gasfilled separator GARIS [4,5] at RIKEN. With SHIP the concept of cold fusion of massive nuclear systems was convincingly confirmed by the observation of the one-neutron evaporation channel in the production of 247Rf in an irradiation of 208Pb with 50Ti [6] in 1981 which opened the way to the transactinide region. At SHIP the elements bohrium (107) to copernicium (112) were discovered [7]. A new closed shell region around hassium was found. The RIKEN experiments started in 2002. They confirmed the GSI results and in addition improved the data on structure and production of elements hassium to copernicium significantly. The heaviest element ever created in a cold fusion reaction, Z = 113, was observed at GARIS [8,9].

  1. Trojan Horse particle invariance in fusion reactions

    NASA Astrophysics Data System (ADS)

    Pizzone, R. G.; Spitaleril, C.; Bertulani, C.; Mukhamedzhanov, A.; Blokhintsev, L.; La Cognata, M.; Lamia, L.; Spartá, R.; Tumino, A.

    2015-01-01

    Trojan Horse method plays an important part for the measurement of several charged particle induced reactions cross sections of astrophysical interest. In order to better understand its cornerstones and the related applications to different astrophysical scenarios several tests were performed to verify all its properties and the possible future perspectives. The Trojan Horse nucleus invariance for the binary reactions d(d,p)t, 6,7Li(p,α)3,4He was therefore tested using the appropriate quasi free break- ups, respectively. In the first cases results from 6Li and 3He break up were used, while for the lithium fusion reactions break-ups of 2H and 3He were compared. The astrophysical S(E)-factors for the different processes were then extracted in the framework of the PlaneWave Approximation applied to the different break-up schemes. The obtained results are compared with direct data as well as with previous indirect investigations. The very good agreement between data coming from different break-up schemes confirms the applicability of the plane wave approximation and suggests the independence of binary indirect cross section on the chosen Trojan Horse nucleus also for the present cases. Moreover the astrophysical implications of the results will also be discussed in details.

  2. Secondary Nuclear Reactions in Magneto-Inertial Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Knapp, Patrick

    2014-10-01

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

  3. Confirmation Of Super Heavy Element Production In {sup 48}Ca Induced Fusion Reactions A Handshake Of Physics And Chemistry For Element 112

    SciTech Connect

    Hofmann, S.; Ackermann, D.; Burkhard, H. G.; Heinz, S.; Hessberger, F. P.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Muenzenberg, G.; Schoett, H. J.; Sulignano, B.; Antalic, S.; Saro, S.; Streicher, B.; Venhart, M.; Yeremin, A. V.; Comas, V. F.; Heredia, J. A.

    2008-05-12

    The production of {sup 283}112 in {sup 48}Ca induced nuclear reactions was investigated using physical and chemical separation techniques. In the reaction {sup 48}Ca on {sup 238}U, four events were registered at the SHIP velocity filter. The mean atomic mass of the evaporation residues (EVR)

  4. Measuring D(d,p)T fusion reactant energy spectra with Doppler shifted fusion products

    SciTech Connect

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

    2010-06-15

    Deuterium fusion reactant energy spectra have been measured using a diagnostic that records the Doppler shift imparted to charged particle fusion products of the D(d,p)T reaction by the center-of-mass velocity of the deuterium reactants. This diagnostic, known as the fusion ion Doppler shift diagnostic (FIDO) measures fast deuterium energy spectra in the inertial electrostatic confinement (IEC) experiment at the University of Wisconsin-Madison {l_brace}Santarius et al. [Fusion Sci. Technol. 47, 1238 (2005)]{r_brace}, a device to confine high energy light ions in a spherically symmetric, electrostatic potential well. This article details the first measurements of the fusion reactant energy spectra in an IEC device as well as the design and principles of operation of the FIDO diagnostic. Scaling of reactant energy spectra with a variety of experimental parameters have been explored.

  5. Fusion reactions of Ni,6458+124Sn

    NASA Astrophysics Data System (ADS)

    Jiang, C. L.; Stefanini, A. M.; Esbensen, H.; Rehm, K. E.; Almaraz-Calderon, S.; Avila, M. L.; Back, B. B.; Bourgin, D.; Corradi, L.; Courtin, S.; Fioretto, E.; Galtarossa, F.; Goasduff, A.; Haas, F.; Mazzocco, M. M.; Montanari, D.; Montagnoli, G.; Mijatovic, T.; Sagaidak, R.; Santiago-Gonzalez, D.; Scarlassara, F.; Strano, E. E.; Szilner, S.

    2015-04-01

    Measurements of fusion excitation functions of 58Ni+124Sn and 64Ni+124Sn are extended towards lower energy to cross sections of 1 μ b and are compared to detailed coupled-channels calculations. The calculations clearly show the importance of including transfer reactions in a coupled-channels treatment for such heavy systems. This result is different from the conclusion made in a previous article which claimed that the influence of transfer on fusion is not important for fusion reactions of Ni +Sn . In the energy region studied in this experiment no indication of fusion hindrance has been observed, which is consistent with a systematic study of this behavior.

  6. Fusion product studies via fast ion D-D and D-3He fusion on JET

    NASA Astrophysics Data System (ADS)

    Sharapov, S. E.; Hellsten, T.; Kiptily, V. G.; Craciunescu, T.; Eriksson, J.; Fitzgerald, M.; Girardo, J.-B.; Goloborod'ko, V.; Hellesen, C.; Hjalmarsson, A.; Johnson, T.; Kazakov, Y.; Koskela, T.; Mantsinen, M.; Monakhov, I.; Nabais, F.; Nocente, M.; Perez von Thun, C.; Rimini, F.; Santala, M.; Schneider, M.; Tardocchi, M.; Tsalas, M.; Yavorskij, V.; Zoita, V.; Contributors, JET

    2016-11-01

    Dedicated fast ion D-D and D-3He fusion experiments were performed on JET with carbon wall (2008) and ITER-like wall (2014) for testing the upgraded neutron and energetic ion diagnostics of fusion products. Energy spectrum of D-D neutrons was the focus of the studies in pure deuterium plasmas. A significant broadening of the energy spectrum of neutrons born in D-D fast fusion was observed, and dependence of the maximum D and D-D neutron energies on plasma density was established. Diagnostics of charged products of aneutronic D-3He fusion reactions, 3.7 MeV alpha-particles similar to those in D-T fusion, and 14.6 MeV protons, were the focus of the studies in D-3He plasmas. Measurements of 16.4 MeV gamma-rays born in the weak secondary branch of D(3He, γ)5Li reaction were used for assessing D-3He fusion power. For achieving high yield of D-D and D-3He reactions at relatively low levels of input heating power, an acceleration of D beam up to the MeV energy range was used employing 3rd harmonic (f=3{{f}CD} ) ICRH technique. These results were compared to the techniques of D beam injection into D-3He mixture, and 3He-minority ICRH in D plasmas.

  7. Evaluation of charged-particle reactions for fusion applications

    SciTech Connect

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

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Ki, Dai-Han; Jung, Young-Dae

    2011-02-01

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

  9. The effect of proton halo on fusion reactions

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    In a recent brief report [Kumar et al., Phys. Rev. C 89, 027601 (2014)] we proposed a method to include the effect of a large break up in fusion reactions with neutron and proton halo nuclei. A stronger enhancement on the total fusion cross section was found for the proton case. However, neither complete nor incomplete fusion was studied and only one target was considered. Here, we revisit the problem in order to address the importance of complete and incomplete fusion. The sensitivity of the cross section to the target is also explored.

  10. Bibliography of fusion product physics in tokamaks

    SciTech Connect

    Hively, L. M.; Sigmar, D. J.

    1989-09-01

    Almost 700 citations have been compiled as the first step in reviewing the recent research on tokamak fusion product effects in tokamaks. The publications are listed alphabetically by the last name of the first author and by subject category.

  11. Basic distinctions between cold- and hot-fusion reactions in the synthesis of superheavy elements

    NASA Astrophysics Data System (ADS)

    Nasirov, A. K.; Muminov, A. I.; Giardina, G.; Mandaglio, G.

    2014-07-01

    Superheavy elements (SHE) of charge number in the range of Z = 106-112 were synthesized in so-called cold-fusion reactions. The smallness of the excitation energy of compound nuclei is the main advantage of cold-fusion reactions. However, the synthesis of SHEs of charge number in the region of Z ≥ 112 is strongly complicated in cold-fusion reactions by a sharp decrease in the cross section of a compound nucleus formation in the entrance channel because of superiority of quasifission in the competition with complete fusion. Two favorable circumstances contributed to the success of the experiments aimed at the synthesis of the Z = 113-118 elements and performed at the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research: large cross sections for the production of a compound nucleus, which are characteristic of hot-fusion reactions, and an increase in the fission barrier for nuclei toward the stability island. The factor that complicates the formation of a compound nucleus in cold-fusion reactions is discussed.

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

    SciTech Connect

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

    1990-05-01

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

  13. Adiabatic self-consistent collective path in nuclear fusion reactions

    NASA Astrophysics Data System (ADS)

    Wen, Kai; Nakatsukasa, Takashi

    2017-07-01

    Collective reaction paths for fusion reactions 16O+α →20Ne and 16O+16O→32S are microscopically determined on the basis of the adiabatic self-consistent collective coordinate (ASCC) method. The collective path is maximally decoupled from other intrinsic degrees of freedom. The reaction paths turn out to deviate from those obtained with standard mean-field calculations with constraints on quadrupole and octupole moments. The potentials and inertial masses defined in the ASCC method are calculated along the reaction paths, which leads to the collective Hamiltonian used for calculation of the subbarrier fusion cross sections. The inertial mass inside the Coulomb barrier may have a significant influence on the fusion cross section at the deep subbarrier energy.

  14. Recent developments in heavy-ion fusion reactions

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Esbensen, H.; Jiang, C. L.; Rehm, K. E.

    2014-01-01

    In this review the main advances in heavy-ion fusion research that have taken place over the last decade are addressed. During this period, experimental studies have been extended to deep sub-barrier energies to reveal the unexpected phenomenon of fusion hindrance. The coupled-channels descriptions have been refined to include the effects of nucleon transfer and to account for the fusion hindrance in terms of the ion-ion potential in the strongly overlapping region. Substantial progress has been made in time-dependent Hartree-Fock theory to the point that this approach now can make parameter-free predictions of heavy-ion fusion excitation functions. As several heavy-ion fusion reactions are of crucial importance in late-stage giant-star evolution, these reactions continue to be studied with better experimental and theoretical tools in order to provide improved input to astrophysical models. The effects of loosely bound valence nucleons on the fusion cross sections are the focus of a number of experimental studies involving radioactive beams, which have only recently become available. And finally, as the active field of synthesizing superheavy elements relies on heavy-ion fusion to reach the nuclei of interest, it is important to understand the fusion dynamics that plays a crucial role in both the "cold-fusion" and "hot-fusion" approaches to the superheavy island of stability. Also this area has seen significant progress in several different approaches to the problem of predicting the cross sections for formation and survival of these rare nuclei.

  15. /sup 18/O + /sup 12/C fusion-evaporation reaction

    SciTech Connect

    Heusch, B; Beck, C; Coffin, J P; Freeman, R M; Gallmann, A; Haas, F; Rami, F; Wagner, P; Alburger, D E

    1980-01-01

    A study of the /sup 18/O + /sup 12/C fusion evaporation reaction has been undertaken for 2 reasons: to make a systematic study of the formation cross section for each individual evaporation residue over a broad excitation energy region in the compound nucleus /sup 30/Si:30 to 62 MeV; and to compare all results to fusion-evaporation calculations done in the framework of the Hauser-Feschbach statistical model.

  16. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics.

    PubMed

    Cheon, MunSeong; Kim, Junghee

    2015-08-01

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  17. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    NASA Astrophysics Data System (ADS)

    Cheon, MunSeong; Kim, Junghee

    2015-08-01

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  18. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    SciTech Connect

    Cheon, MunSeong Kim, Junghee

    2015-08-15

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  19. The new possibility of the fusion p + 11B chain reaction being induced by intense laser pulses

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    We discuss the experimental and theoretical principal schemes of a thermonuclear reactor, based on the fusion reaction p + 11B: beam collisions, fusion in degenerate plasmas, ignition at the plasma, particle acceleration by nonlinear ponderomotive forces and irradiation of the solid 11B target by a proton beam at the Coulomb explosion of hydrogen microdroplets. The fusion reaction p + 11B can be initiated by ultrashort high intensity laser pulses under conditions far from thermodynamic equilibrium. This may result in fusion products containing a small amount of neutrons and other nuclear radiation effects. It was found that the fusion reaction p + 11B produces further nuclear reactions and generates high-energy protons. The latter can support the chain reaction process. Our approach allows us to also investigate nuclear reactions in the early Universe and in stars.

  20. Fusion by diffusion. II. Synthesis of transfermium elements in cold fusion reactions

    SciTech Connect

    Swiatecki, W.J.; Siwek-Wilczynska, K.; Wilczynski, J.

    2005-01-01

    We describe a method of estimating cross sections for the synthesis of very heavy nuclei by the fusion of two lighter ones. The cross section is considered to be the product of three factors: the cross section for the projectile to overcome the Coulomb barrier, the probability that the resulting composite nucleus reaches the compound nucleus configuration by a shape fluctuation treated as a diffusion of probability in one dimension, and the probability that the excited compound nucleus survives fission. Semi-empirical formulas for the mean Coulomb barrier height and its distribution around the mean are constructed. After overcoming the Coulomb barrier the system is assumed to be injected into an 'asymmetric fission valley' by a rapid growth of the neck between the target and projectile at approximately frozen asymmetry and elongation. Diffusion in the elongation coordinate in this valley can occasionally bring the system over the saddle separating the injection point from the compound nucleus configuration. This is the stage that accounts for the hindrance to fusion observed for very heavy reacting systems. The competition between deexcitation of the compound nucleus by neutron emission and fission is treated by standard methods, but an interesting insight allows one to predict in an elementary way the location of the maximum in the resulting excitation function. Adjusting one parameter in the theory causes the calculated peak cross sections to agree within about a factor of 2 or so with 12 measured or estimated values for 'cold' one-neutron-out reactions where targets of {sup 208}Pb and {sup 209}Bi are bombarded with projectiles ranging from {sup 48}Ca to {sup 70}Zn. The centroids of the excitation functions agree with theory to within 1 or 2 MeV for the six cases where they have been determined, and their widths are reproduced. 'Hot' fusion reactions, where several neutrons are emitted, are not treated, except that a comparison is made between the hindrance

  1. Fusion reactors for hydrogen production via electrolysis

    NASA Astrophysics Data System (ADS)

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

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of 50 to 70% are projected for fusion reactors using high temperature blankets.

  2. Accelerators for Inertial Fusion Energy Production

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  3. Calculation of evaporation residue cross sections for the synthesis of superheavy nuclei in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Zhang, Jinjuan; Wang, Chengbin; Ren, Zhongzhou

    2013-07-01

    A systematic calculation of the production cross sections of superheavy elements (SHEs) in hot fusion reactions is performed. First, we analyze the reactions of 48Ca + 238U, 244Pu, and 248Cm, from which the parameter values in the model for each process are determined by comparing the calculated capture, fusion, and evaporation residue (ER) cross sections, respectively, with the measured data. Then, we calculate the ER cross sections of other hot fusion reactions with the derived parameter values. The calculated results are in good agreement with the available data. Furthermore, the possible isotope production cross sections of elements 118 and 117 in the reactions of 48Ca + ACf and ABk are computed. We find that with the increase of the neutron number of the target, the production cross sections of the SHEs increase, primarily caused by the smaller neutron separation energies of the corresponding neutron-rich compound nucleus (CN). Finally, the production cross sections of elements 120 and 119 are evaluated in fusion-evaporation reactions with 50Ti as a projectile.

  4. Effects of entrance channel on fusion probability in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Zhu, Long; Su, Jun; Huang, Ching-Yuan; Zhang, Feng-Shou

    2016-12-01

    Within the framework of the dinuclear system (DNS) model, the fusion reactions leading to the compound nuclei 274Hs* and 286Cn* are investigated. The fusion probability as a function of DNS excitation energy is studied. The calculated results are in good agreement with the available experimental data. The obtained results show that the fusion probabilities are obviously enhanced for the reactions located at high place in potential energy surface, although these reactions may have small values of mass asymmetry. It is found that the enhancement is due to the large potential energy of the initial DNS. Supported by Natural Science Foundation of Guangdong Province China (2016A030310208). National Natural Science Foundation of China (11605296, 11405278, 11505150, 11635003), Fundamental Research Funds for the Central Universities (15 lgpy 30) and China Postdoctoral Science Foundation (2015M582730)

  5. Dynamical Dipole mode in heavy-ion fusion reactions

    NASA Astrophysics Data System (ADS)

    Parascandolo, C.; Pierroutsakou, D.; Alba, R.; Del Zoppo, A.; Maiolino, C.; Santonocito, D.; Agodi, C.; Baran, V.; Boiano, A.; Colonna, M.; Coniglione, R.; De Filippo, E.; Di Toro, M.; Emanuele, U.; Farinon, F.; Guglielmetti, A.; La Commara, M.; Martin, B.; Mazzocchi, C.; Mazzocco, M.; Rizzo, C.; Romoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Torresi, D.; Trifirò, A.; Trimarchi, M.

    2017-06-01

    In this work we give evidence for the first time of the Dynamical Dipole mode in a heavy system in the A˜190 mass region, in both fusion-evaporation and fission events. The 40,48Ca + 152,144Sm reactions at E lab =11(10.1) MeV/nucleon were employed. Our results for evaporation and fission events (preliminary) show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously.

  6. Microdroplet fusion mass spectrometry for fast reaction kinetics

    PubMed Central

    Lee, Jae Kyoo; Kim, Samuel; Nam, Hong Gil; Zare, Richard N.

    2015-01-01

    We investigated the fusion of high-speed liquid droplets as a way to record the kinetics of liquid-phase chemical reactions on the order of microseconds. Two streams of micrometer-size droplets collide with one another. The droplets that fused (13 μm in diameter) at the intersection of the two streams entered the heated capillary inlet of a mass spectrometer. The mass spectrum was recorded as a function of the distance x between the mass spectrometer inlet and the droplet fusion center. Fused droplet trajectories were imaged with a high-speed camera, revealing that the droplet fusion occurred approximately within a 500-μm radius from the droplet fusion center and both the size and the speed of the fused droplets remained relatively constant as they traveled from the droplet fusion center to the mass spectrometer inlet. Evidence is presented that the reaction effectively stops upon entering the heated inlet of the mass spectrometer. Thus, the reaction time was proportional to x and could be measured and manipulated by controlling the distance x. Kinetic studies were carried out in fused water droplets for acid-induced unfolding of cytochrome c and hydrogen–deuterium exchange in bradykinin. The kinetics of the former revealed the slowing of the unfolding rates at the early stage of the reaction within 50 μs. The hydrogen–deuterium exchange revealed the existence of two distinct populations with fast and slow exchange rates. These studies demonstrated the power of this technique to detect reaction intermediates in fused liquid droplets with microsecond temporal resolution. PMID:25775573

  7. Microdroplet fusion mass spectrometry for fast reaction kinetics.

    PubMed

    Lee, Jae Kyoo; Kim, Samuel; Nam, Hong Gil; Zare, Richard N

    2015-03-31

    We investigated the fusion of high-speed liquid droplets as a way to record the kinetics of liquid-phase chemical reactions on the order of microseconds. Two streams of micrometer-size droplets collide with one another. The droplets that fused (13 μm in diameter) at the intersection of the two streams entered the heated capillary inlet of a mass spectrometer. The mass spectrum was recorded as a function of the distance x between the mass spectrometer inlet and the droplet fusion center. Fused droplet trajectories were imaged with a high-speed camera, revealing that the droplet fusion occurred approximately within a 500-μm radius from the droplet fusion center and both the size and the speed of the fused droplets remained relatively constant as they traveled from the droplet fusion center to the mass spectrometer inlet. Evidence is presented that the reaction effectively stops upon entering the heated inlet of the mass spectrometer. Thus, the reaction time was proportional to x and could be measured and manipulated by controlling the distance x. Kinetic studies were carried out in fused water droplets for acid-induced unfolding of cytochrome c and hydrogen-deuterium exchange in bradykinin. The kinetics of the former revealed the slowing of the unfolding rates at the early stage of the reaction within 50 μs. The hydrogen-deuterium exchange revealed the existence of two distinct populations with fast and slow exchange rates. These studies demonstrated the power of this technique to detect reaction intermediates in fused liquid droplets with microsecond temporal resolution.

  8. Target production for inertial fusion energy

    SciTech Connect

    Woodworth, J.G.; Meier, W.

    1995-03-01

    Inertial fusion energy (IFE) power plants will require the ignition and burn of 5-10 fusion fuel targets every second. The technology to economically mass produce high-quality, precision targets at this rate is beyond the current state of the art. Techniques that are scalable to high production rates, however, have been identified for all the necessary process steps, and many have been tested in laboratory experiments or are similar to current commercial manufacturing processes. In this paper, we describe a baseline target factory conceptual design and estimate its capital and operating costs. The result is a total production cost of {approximately}16{cents} per target. At this level, target production represents about 6% of the estimated cost of electricity from a 1-GW{sub e} IFE power plant. Cost scaling relationships are presented and used to show the variation in target cost with production rate and plant power level.

  9. Thermochemical hydrogen production based on magnetic fusion

    NASA Astrophysics Data System (ADS)

    Krikorian, O. H.; Brown, L. C.

    1982-06-01

    Conceptual design studies were carried out on an integrated fusion/chemical plant system using a Tandem Mirror Reactor fusion energy source to drive the General Atomic Sulfur-Iodine Water-Splitting Cycle and produce hydrogen as a future feedstock for synthetic fuels. Blanket design studies for the Tandem Mirror Reactor show that several design alternatives are available for providing heat at sufficiently high temperatures to drive the General Atomic Cycle. The concept of a Joule-boosted decomposer is introduced in one of the systems investigated to provide heat electrically for the highest temperature step in the cycle (the SO3 decomposition step), and thus lower blanket design requirements and costs. Flowsheeting and conceptual process designs have been developed for a complete fusion-driven hydrogen plant, and the information has been used to develop a plot plan for the plant and to estimate hydrogen production costs.

  10. Macroscopic theory of heavy-ion fusion reactions

    NASA Astrophysics Data System (ADS)

    Hong, S.-W.; Lee, Y. J.; Kim, B. T.; Cha, D.

    1989-05-01

    We have studied the heavy-ion fusion reactions by a macroscopic model which was proposed by Bertsch several years ago. It employed the Newtonian dynamics and was constructed in such a way that the essential features of time-dependent Hartree-Fock results could be reproduced. We have applied the model to fusion of light heavy-ion systems leading to the same compound nucleus 56Ni. It is shown that the model, being incorporated with the angular-momentum-dependent extra-push energy of Swiatecki, can account well for the fusion cross sections up to very high energies where cross section decreases as energy increases, and that the main reason for the decrease is the opening of the low angular momentum window.

  11. Angular momentum effects in fusion-fission and fusion-evaporation reactions

    SciTech Connect

    Plasil, F.

    1980-01-01

    The study of heavy-ion fusion reactions is complicated by the possible contributions of several mechanisms. The various types of heavy-ion-induced fission are discussed. Then compound-nucleus fission is considered with reference to fission barriers deduced from heavy-ion-induced fission. Next, the problems associated with measured values of evaporation-residue cross sections and the angular momentum dependence of incomplete fusion are examined. Finally, the de-excitation of compound nuclei is again taken up, this time with reference to the greatly enhanced ..cap alpha.. emission predicted on the basis of the rotating liquid drop model. 24 figures. (RWR)

  12. Reproducible cold fusion reaction using a complex cathode

    SciTech Connect

    Arata, Y.; Zhang, Y.C. )

    1992-09-01

    This paper discusses a new complex cathode which was developed, consisting of a nickel (or palladium) rod with a palladium layer applied by plasma spraying. High reproducibility of a cold fusion reaction is confirmed by using this cathode. The palladium layer activates the surface functions of the deuterated cathode, and reliable evidence is obtained that a new type of heat generation occurred in the complex cathode.

  13. Possibilities for synthesis of new isotopes of superheavy elements in fusion reactions

    NASA Astrophysics Data System (ADS)

    Zagrebaev, V. I.; Karpov, A. V.; Greiner, Walter

    2012-01-01

    Background. In the “cold” fusion reactions based on the use of lead and bismuth targets, the proton-rich isotopes of superheavy (SH) elements up to Z=113 have been produced. More neutron-rich isotopes of SH elements (up to Z=118) have been synthesized in “hotter” fusion reactions of 48Ca with actinide targets. α-decay half-lives of different isotopes of the same SH elements (for example, 112) were found to vary by several orders of magnitude. This indicates strong shell effects in this area of the nuclear map. The understanding of these effects and other properties of SH nuclei is strongly impeded by the absence of experimental data on decay properties of the not-yet-synthesized isotopes of SH elements located between those produced in the “cold” fusion reactions and those produced in the “hot” fusion reactions and also by the yet missing neutron-enriched isotopes of these elements.Purpose. In this paper we search for the optimal fusion reactions which may be used to fill this gap of the nuclear map and significantly extend the area of known SH nuclei.Method. For the calculation of the cross sections we use the same approach which was employed earlier for successful predictions of all 48Ca induced fusion reactions.Results. Several fusion reactions of the stable projectiles 40Ar, 44Ca, and 48Ca with different isotopes of actinides (lighter and heavier than those that have been already utilized in the Dubna experiments) could be used for synthesis of new SH nuclei. Predicted cross sections for the production of new isotopes of SH nuclei were found to be quite large, and the corresponding experiments can be easily performed at existing facilities. For the first time a “narrow pathway” to the middle of the island of stability was found owing to possible β+ decay of SH nuclei 291115 and 291114 which could be formed in ordinary fusion reactions.

  14. Neutron detectors for fusion reaction-rate measurements

    SciTech Connect

    Lerche, R.A.; Phillion, D.W.; Landen, O.L.; Murphy, T.J.; Jaanimagi, P.A.

    1994-02-10

    Fusion reactions in an inertial-confinement fusion (ICF) target filled with deuterium or a deuterium/tritium fuel release nearly monoenergetic neutrons. Because most the neutrons leave the compressed target without collision, they preserve reaction-rate information as they travel radially outward from their point of origin. Three fast, neutron detector techniques, each capable of measuring the fusion reaction-rate of ICF targets, have been demonstrated. The most advanced detector is based on the fast rise-time of a commercial plastic scintillator material (BC-422) which acts as a neutron-to-light converter. Signals, which are recorded with a fast optical streak camera, have a resolution of 25 ps. Good signals can be recorded for targets producing only 5 x 10{sup 7} DT neutrons. Two other detectors use knock-on collisions between neutrons and protons in a thin polyethylene (CH{sub 2}) converter. In one, the converter is placed in front of the photocathode of an x-ray streak camera. Recoil protons pass through the photocathode and knock out electrons which are accelerated and deflected to produce a signal. Resolutions < 25 ps are possible. In the other, the converter is placed in front of a microchannel plate (MCP) with a gated microstrip. Recoil protons eject electrons from the gold layer forming the microstrip. If a gate pulse is present, the signal is amplified. Present gate times are about 80 ps.

  15. An accelerator based fusion-product source for development of inertial confinement fusion nuclear diagnostics.

    PubMed

    McDuffee, S C; Frenje, J A; Séguin, F H; Leiter, R; Canavan, M J; Casey, D T; Rygg, J R; Li, C K; Petrasso, R D

    2008-04-01

    A fusion-product source, utilizing a 150 kV Cockraft-Walton linear accelerator, has been refurbished to provide a reliable nuclear diagnostic development tool to the national inertial confinement fusion (ICF) research program. The accelerator is capable of routinely generating DD reaction rates at approximately 10(7)/s when using a 150 kV, 150 microA deuterium (D) beam onto an erbium (Er) or titanium (Ti) target doped with D, and D(3)He reaction rates at approximately 5 x 10(5)/s when using a using a 120 kV, approximately 100 microA D beam onto a Er or Ti target doped with (3)He. The new accelerator is currently being used in a number of projects related to the national ICF program at the OMEGA Laser Fusion Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], which includes the wedge range filter charged-particle spectrometry program [F. H. Seguin et al., Rev. Sci Instrum. 75, 3520 (2004)] and the magnetic recoil neutron spectrometer [J. A. Frenje et al., Rev. Sci. Instrum. 72, 854 (2001)].

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

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

    PubMed

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

    2014-10-10

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

  18. Formation of superheavy elements in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Smolańczuk, Robert

    2001-04-01

    We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are 209Bi(86Kr, 1n)294119, 208Pb(88Sr, 1n)295120, and 209Bi(88Sr, 1n)296121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions 136Xe(124Sn, 1n)259Rf, 136Xe(136Xe, 1n)271Hs,138Ba(136Xe, 1n)273110, and 140Ce(136Xe, 1n)275112. Although shell effects in the magic nuclei 124Sn, 136Xe, 138Ba, and 140Ce are not as strong as in 208Pb and 209Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.

  19. Reaction product imaging

    SciTech Connect

    Chandler, D.W.

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  20. New information on survival probabilities in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Loveland, Walter

    2014-09-01

    Recently we studied the fission-neutron emission competition in highly excited (E* = 63 MeV) 274Hs (Z = 108) (where the fission barrier is due to shell effects) formed by a hot fusion reaction. At this excitation energy, these shell effects are expected to be ``washed out'' leaving a barrier height of <= 1 MeV. Matching cross bombardments (26Mg + 248Cm and 25Mg + 248Cm) were used to identify the properties of first chance fission of 274Hs. A Harding-Farley analysis of the fission neutrons emitted in the 25,26Mg + 248Cm reaction was performed to identify the pre- and post-scission components of the neutron multiplicities in each system. (Γn/ Γt) for the first chance fission of 274Hs is 0.89 +/- 0.13, i.e., ~ 90% of the highly excited nuclei survive. The high value of that survival probability is due to dissipative effects (Kramers) during de-excitation. A proper description of the survival probabilities of excited superheavy nuclei formed in hot fusion reactions requires consideration of both dynamic and static (shell-related) effects. A re-analysis of several hot fusion survival probabilities under these constraints is presented. Recently we studied the fission-neutron emission competition in highly excited (E* = 63 MeV) 274Hs (Z = 108) (where the fission barrier is due to shell effects) formed by a hot fusion reaction. At this excitation energy, these shell effects are expected to be ``washed out'' leaving a barrier height of <= 1 MeV. Matching cross bombardments (26Mg + 248Cm and 25Mg + 248Cm) were used to identify the properties of first chance fission of 274Hs. A Harding-Farley analysis of the fission neutrons emitted in the 25,26Mg + 248Cm reaction was performed to identify the pre- and post-scission components of the neutron multiplicities in each system. (Γn/ Γt) for the first chance fission of 274Hs is 0.89 +/- 0.13, i.e., ~ 90% of the highly excited nuclei survive. The high value of that survival probability is due to dissipative effects (Kramers

  1. Charged fusion product diagnostics in Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Boivin, R. L.; Kurz, C.; Lo, D. H.; Fiore, C. L.; Granetz, R.; Petrasso, R. D.

    1992-10-01

    With a plasma current of up to 3 MA, toroidal field of up to 9 T, the confinement of the charged fusion products (CFPs) in Alcator C-Mod is expected to be excellent. For example, at maximum current and field, classical losses of the 0.8 MeV 3He, 1 MeV triton, 3 MeV proton, 3.5 and 3.7 MeV alphas are expected to be less than 5%. For the study of the global confinement of CFPs, we plan to measure the burnup of the 1 MeV triton (from the D-D reaction) using a proton recoil detector (NE-213) for the detection of the 14 MeV neutron resulting from the secondary fusion reaction (D-T). On the other hand, loss measurements of CFPs will be made inside the first wall with two detectors (one at the bottom, one at the midplane) using silicon based detectors. The midplane detector will be used to diagnose D-3He plasmas by looking at the unconfined 14.7 MeV proton. In addition to the derivation of fusion yield, energy distribution of the escaping protons will provide information about the ion velocity distribution of the reactants. The bottom detector is time, pitch angle and energy resolved, and thus will be used to study loss mechanisms such as first orbit, toroidal field ripple and magnetohydrodynamics-induced diffusion.

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

    SciTech Connect

    Peterson, I.

    1996-10-19

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

  3. 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.

  4. Possibilities of synthesis of unknown isotopes of superheavy nuclei with charge numbers Z > 108 in asymmetric actinide-based complete fusion reactions

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    The possibilities of production of new isotopes of superheavy nuclei with charge numbers Z = 109-114 in various asymmetric hot fusion reactions are studied for the first time. The excitation functions of the formation of these isotopes in the xn evaporation channels are predicted and the optimal conditions for the synthesis are proposed. The products of the suggested reactions can fill a gap of unknown isotopes between the isotopes of the heaviest nuclei obtained in cold and hot complete fusion reactions.

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

    SciTech Connect

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

    2012-06-06

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

  6. Detailed studies of survival probabilities in hot fusion reactions

    NASA Astrophysics Data System (ADS)

    Yao, Liangyu; Yanez, Ricardo; Loveland, Walter

    2011-10-01

    In the synthesis of new heavy nuclei by hot fusion reactions, the cross section for producing a new heavy nucleus, σEVR, can be represented as σEVR(EC.M.)=&Jmaxcirc;J=0σCN(Ec.m.,J) .Wsur(Ec.m.,J) where σCN is the complete fusion cross section and Wsur is the survival probability of the completely fused system. The survival probability is essentially the probability of de-exciting by neutron emission instead of fission. In this work, we are attempting to measure the survival probability, Wsur, for the first chance fission of excited Hs nuclei. We form the Hs nuclei using the ^25,26Mg + ^248Cm reaction. We measure the neutrons associated with pre-fission emission and those emitted by the fission fragments after fission using six BC501 neutron detectors and six silicon fission fragment detectors. We measure the angular distribution of the emitted neutrons and are able to separate the pre- and post-fission neutrons.

  7. Measurement of the Survival Probabilities for Hot Fusion Reactions

    NASA Astrophysics Data System (ADS)

    Yanez, R.; Loveland, W.; Yao, L.; Barrett, J. S.; Zhu, S.; Back, B. B.; Khoo, T. L.; Alcorta, M.; Albers, M.

    2014-04-01

    We have studied the fission-neutron emission competition in highly excited Hs274 (Z =108) (where the fission barrier is due to shell effects) formed by a hot fusion reaction. Matching cross bombardments (Mg26+Cm248 and Mg25+Cm248) were used to identify the properties of first chance fission of Hs274. A Harding-Farley analysis of the fission neutrons emitted in the Mg25,26+Cm248 was performed to identify the prescission and postscission components of the neutron multiplicities in each system. (Γn/Γt) for the first chance fission of Hs274 (E*=63 MeV) is 0.89±0.13; i.e., ˜90% of the highly excited nuclei survive. The high value of that survival probability is due to dissipative effects during deexcitation. A proper description of the survival probabilities of excited superheavy nuclei formed in hot fusion reactions requires consideration of both dynamic and static (shell-related) effects.

  8. Studies of Neutron-Deficient Nuclei Near the Z = 82 Shell Closure via Cold Fusion Reactions

    NASA Astrophysics Data System (ADS)

    Carpenter, M. P.; Kondev, F. G.; Janssens, R. V. F.; Seweryniak, D.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Zhu, S.; Camera, F.; Bracco, A.; Million, B.; Leoni, S.; Jenkins, D. G.; Wadsworth, R.

    2009-03-01

    Over the last decade, we have performed in-beam experiments using Gammasphere+FMA to measure excited states in proton-rich Au, Hg, Tl and Pb isotopes. In these studies, the use of the FMA is essential in order to differentiate evaporation residues from the large fission background which dominates the reaction cross-section. In addition, we have found that using near-symmetric reactions at bombarding energies near the Coloumb barrier is beneficial in performing these studies. By keeping the bombarding energy low, fission is minimized and the reaction products are concentrated in only a few channels. New results have recently been obtained using the 90Zr+92Mo reaction to study shape co-existence in 181Tl via the lp evaporation channel. In addition, we have measured the total γ-ray energy and multiplicity associated with the surviving compund system, 179Au, following the fusion reaction, 90Zr+89Y.

  9. Formation of superheavy elements in cold fusion reactions

    SciTech Connect

    Smolanczuk, Robert

    2001-04-01

    We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are {sup 209}Bi({sup 86}Kr, 1n){sup 294}119, {sup 208}Pb({sup 88}Sr, 1n){sup 295}120, and {sup 209}Bi({sup 88}Sr, 1n){sup 296}121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions {sup 136}Xe({sup 124}Sn, 1n){sup 259}Rf, {sup 136}Xe({sup 136}Xe, 1n){sup 271}Hs,{sup 138}Ba({sup 136}Xe, 1n){sup 273}110, and {sup 140}Ce({sup 136}Xe, 1n){sup 275}112. Although shell effects in the magic nuclei {sup 124}Sn, {sup 136}Xe, {sup 138}Ba, and {sup 140}Ce are not as strong as in {sup 208}Pb and {sup 209}Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.

  10. Methods of detection using a cellulose binding domain fusion product

    DOEpatents

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1999-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  11. Methods of detection using a cellulose binding domain fusion product

    DOEpatents

    Shoseyov, O.; Shpiegl, I.; Goldstein, M.A.; Doi, R.H.

    1999-01-05

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques. 34 figs.

  12. Innovative energy production in fusion reactors

    NASA Astrophysics Data System (ADS)

    Iiyoshi, A.; Momota, H.; Motojima, O.; Okamoto, M.; Sudo, S.; Tomita, Y.; Yamaguchi, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-10-01

    Concepts of innovative energy production in neutron-lean fusion reactors without having the conventional turbine-type generator are proposed for improving the plant efficiency. These concepts are: (1) traveling wave direct energy conversion of 14.7 MeV protons; (2) cusp type direct energy conversion of charged particles; (3) efficient use of radiation with semiconductor and supplying clean fuel in a form of hydrogen gas; and (4) direct energy conversion from deposited heat to electric power with semiconductor utilizing Nernst effect. The candidates of reactors such as a toroidal system and an open system are also studied for application of the new concepts. The study shows the above concepts for a commercial reactor are promising.

  13. Neutron detector for fusion reaction-rate measurements

    SciTech Connect

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

    1993-09-03

    We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25-ps FWHM. A thin piece of scintillator material acts as a neutron-to- light converter. A zoom lens images light from the scintillator surface to a high-speed (15 ps) optical streak camera for recording. The zoom lens allows the scintillator to be positioned between 1 and 50 cm from a target. The camera simulaneously records an optical fiducial pulse which allows the camera time base to be calibrated relative to the incident laser power. Bursts of x rays formed by focusing 20-ps, 2.5-TW laser pulses onto gold disk targets demonstrate the detector resolution to be < 25 ps. We have recorded burn histories for deuterium/tritium-filled targets producing as few as 3 {times} 10{sup 7} neutrons.

  14. Measurements of fusion product emission profiles in tokamaks

    SciTech Connect

    Strachan, J.D.; Heidbrink, W.W.; Hendel, H.W.; Lovberg, J.; Murphy, T.J.; Nieschmidt, E.B.; Tait, G.D.; Zweben, S.J.

    1986-11-01

    The techniques and results of fusion product emission profile measurements are reviewed. While neutron source strength profile measurements have been attempted by several methods, neutron scattering is a limitation to the results. Profile measurements using charged fusion products have recently provided an alternative since collimation is much easier for the charged particles.

  15. RF heating for fusion product studies

    SciTech Connect

    Hellsten, T. Johnson, T.; Sharapov, S. E.; Kiptily, V.; Rimini, F.; Eriksson, J.; Mantsinen, M.; Schneider, M.; Tsalas, M.

    2015-12-10

    Third harmonic cyclotron heating is an effective tool for accelerating deuterium (D) beams to the MeV energy range, suitable for studying ITER relevant fast particle physics in plasmas without significant tritium content. Such experiments were recently conducted in JET with an ITER like wall in D plasmas with {sup 3}He concentrations up to 30% in order to boost the fusion reactivity by D-{sup 3}He reactions. The harmonic cyclotron heating produces high-energy tails in the MeV range of D ions by on-axis heating and of {sup 3}He ions by tangential off-axis heating. The discharges are characterized by long sawtooth free periods and a rich spectrum of MHD modes excited by the fast D and {sup 3}He ions. The partitions of the power, which depend on the distribution function of D, vary strongly over several slowing down times. Self-consistent modelling of the distribution function with the SELFO-light code are presented and compared with experimental data from fast particle diagnostics.

  16. RF heating for fusion product studies

    NASA Astrophysics Data System (ADS)

    Hellsten, T.; Johnson, T.; Sharapov, S. E.; Kiptily, V.; Eriksson, J.; Mantsinen, M.; Schneider, M.; Rimini, F.; Tsalas, M.

    2015-12-01

    Third harmonic cyclotron heating is an effective tool for accelerating deuterium (D) beams to the MeV energy range, suitable for studying ITER relevant fast particle physics in plasmas without significant tritium content. Such experiments were recently conducted in JET with an ITER like wall in D plasmas with 3He concentrations up to 30% in order to boost the fusion reactivity by D-3He reactions. The harmonic cyclotron heating produces high-energy tails in the MeV range of D ions by on-axis heating and of 3He ions by tangential off-axis heating. The discharges are characterized by long sawtooth free periods and a rich spectrum of MHD modes excited by the fast D and 3He ions. The partitions of the power, which depend on the distribution function of D, vary strongly over several slowing down times. Self-consistent modelling of the distribution function with the SELFO-light code are presented and compared with experimental data from fast particle diagnostics.

  17. Escaping charged fusion product spectrometer on Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Lo, Daniel H.; Boivin, Réjean L.; Petrasso, Richard D.

    1995-01-01

    A spectrometer for studying escaping charged fusion products has been designed, built, and installed on the Alcator C-Mod tokamak. The ultimate goal of deploying this diagnostic is to evaluate the effectiveness of 3He minority heating through the broadened spectrum of unconfined 14.7 MeV protons from D-3He reactions. Other physics issues that will be addressed with this diagnostic include: first-orbit losses, central ion temperature, 3He burnup, etc. The spectrometer is located 25.8 cm below the midplane and at least 5 cm behind the shadow of the rf limiter. The diagnostic is equipped with a 300 μm thick ion-implanted-silicon detector that is bakeable up to 200 °C. Eighteen apertures of various dimensions and viewing angles, with aluminum foils of various thicknesses, allow for a choice of different charged fusion products and a control of the signal level. In-vessel calibration is provided by two weak radioactive sources of α particles.

  18. Evidence of complete fusion in the subbarrier {sup 16}O+{sup 238}U reaction

    SciTech Connect

    Nishio, K. Ikezoe, H.; Asai, M.; Tsukada, K.; Mitsuoka, S.; Tsuruta, K.; Satou, K.; Lin, C. J.; Ohsawa, T.

    2006-08-15

    Evaporation residue cross sections in the {sup 16}O+{sup 238}U reaction were measured for the energy range from above-to extreme subbarrier. We used a He-gas-jet system to transport the fusion products, and the {alpha} decay of the evaporation residues was measured by using a rotating wheel system. The measured cross sections for {sup 248,249,250}Fm are reproduced by a statistical model calculation, for which partial cross sections are calculated by a coupled-channel model taking into account the prolate deformation of {sup 238}U. We conclude that complete fusion is the main process in the subbarrier energy region, and quasifission is not an important channel.

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  20. Effects of magnetization on fusion product trapping and secondary neutron spectraa)

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    By magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner Inertial Fusion experiments conducted on the Z machine at Sandia National Laboratories. We show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG . cm, a ˜ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. This is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  1. Effects of magnetization on fusion product trapping and secondary neutron spectra

    DOE PAGES

    Knapp, Patrick F.; Schmit, Paul F.; Hansen, Stephanie B.; ...

    2015-05-14

    In magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, we found that the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used tomore » infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner InertialFusion experiments conducted on the Z machine at Sandia National Laboratories. Furthermore, we show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG · cm, a ~ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. Lastly, this is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.« less

  2. Effects of magnetization on fusion product trapping and secondary neutron spectra

    SciTech Connect

    Knapp, Patrick F.; Schmit, Paul F.; Hansen, Stephanie B.; Gomez, Matthew R.; Hahn, Kelly D.; Sinars, Daniel Brian; Peterson, Kyle J.; Slutz, Stephen A.; Sefkow, Adam B.; Awe, Thomas James; Harding, Eric; Jennings, Christopher A.; Desjarlais, M. P.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Geissel, Matthias; Harvey-Thompson, Adam James; Porter, John L.; Rochau, Gregory A.; Rovang, Dean C.; Ruiz, Carlos L.; Savage, Mark E.; Smith, Ian C.; Stygar, William A.; Herrmann, Mark

    2015-05-14

    In magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, we found that the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner InertialFusion experiments conducted on the Z machine at Sandia National Laboratories. Furthermore, we show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG · cm, a ~ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. Lastly, this is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  3. Effects of magnetization on fusion product trapping and secondary neutron spectra

    SciTech Connect

    Knapp, P. F.; Schmit, P. F.; Hansen, S. B.; Gomez, M. R.; Hahn, K. D.; Sinars, D. B.; Peterson, K. J.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Harding, E.; Jennings, C. A.; Desjarlais, M. P.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Geissel, M.; Harvey-Thompson, A. J.; Porter, J. L.; Rochau, G. A.; and others

    2015-05-15

    By magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner Inertial Fusion experiments conducted on the Z machine at Sandia National Laboratories. We show that in these experiments BR ≈ 0.34(+0.14/−0.06) MG · cm, a ∼ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. This is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  4. Study of near-stability nuclei populated as fission fragments in heavy-ion fusion reactions

    SciTech Connect

    Fotiadis, Nikolaos; Nelson, Ronald O; Devlin, Matthew; Cizewski, Jolie A; Krucken, Reiner; Clark, R M; Fallon, Paul; Lee, I Yang; Macchiavelli, Agusto O; Becker, John A; Younes, Walid

    2010-01-01

    Examples are presented to illustrate the power of prompt {gamma}-ray spectroscopy of fission fragments from compound nuclei with A {approx} 200 formed in fusion-evaporation reactions in experiments using the Gammasphere Ge-detector array. Complementary methods, such as Coulomb excitation and deep-inelastic processes, are also discussed. In other cases (n, xn{gamma}) reactions on stable isotopes have been used to establish neutron excitation functions for {gamma}-rays using a pulsed 'white'-neutron source, coupled to a high-energy-resolution germanium-detector array. The excitation functions can unambiguously assign {gamma}-rays to a specific reaction product. Results from all these methods bridge the gaps in the systematics of high-spin states between the neutron-deficient and neutron-rich nuclei. Results near shell closures should motivate new shell model calculations.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

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

    SciTech Connect

    Maya, I.; Schultz, K.R.; Bourque, R.F.; Cheng, E.T.; Creedon, R.L.; Norman, J.H.; Price, R.J.; Porter, J.; Schuster, H.L.; Simnad, M.J.

    1985-10-01

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

  7. Excitation functions for complete-fusion and transfer reactions in {sup 4}He interaction with {sup 197}Au nuclei

    SciTech Connect

    Kulko, A. A.; Demekhina, N. A.; Kalpakchieva, R.; Muzychka, Yu. A.; Penionzhkevich, Yu. E.; Rassadov, D. N.; Skobelev, N. K.; Testov, D. A.

    2007-04-15

    Excitation functions are measured for the fusion reactions {sup 197}Au({sup 4}He, xn){sup 201-xn}Tl that are induced by alpha-particle interaction with gold nuclei in the energy range 14-36 MeV and in which x neutrons (0 {<=} x {<=} 3) are evaporated. The stack-activation technique was used to record and separate reaction products. Experimental data on the fusion reactions followed by evaporation of one to three neutrons agree with results of previous studies. For the radiative-capture reaction {sup 197}Au({sup 4}He,{gamma}){sup 201}Tl, the upper limit on the cross section proved to be much lower. The excitation functions for the reactions subjected to measurements are compared with the results of calculations based on the statistical model and with the results of an experiment performed previously in a {sup 6}He beam.

  8. Excitation functions for complete-fusion and transfer reactions in 4He interaction with 197Au nuclei

    NASA Astrophysics Data System (ADS)

    Kulko, A. A.; Demekhina, N. A.; Kalpakchieva, R.; Muzychka, Yu. A.; Penionzhkevich, Yu. E.; Rassadov, D. N.; Skobelev, N. K.; Testov, D. A.

    2007-04-01

    Excitation functions are measured for the fusion reactions 197Au(4He, xn)201-xn Tl that are induced by alpha-particle interaction with gold nuclei in the energy range 14 36 MeV and in which x neutrons (0 ≤ x ≤ 3) are evaporated. The stack-activation technique was used to record and separate reaction products. Experimental data on the fusion reactions followed by evaporation of one to three neutrons agree with results of previous studies. For the radiative-capture reaction 197Au(4He,γ)201Tl, the upper limit on the cross section proved to be much lower. The excitation functions for the reactions subjected to measurements are compared with the results of calculations based on the statistical model and with the results of an experiment performed previously in a 6He beam.

  9. Fusion of agarase and neoagarobiose hydrolase for mono-sugar production from agar.

    PubMed

    Alkotaini, Bassam; Han, Nam Soo; Kim, Beom Soo

    2017-02-01

    In enzymatic saccharification of agar, endo- and exo-agarases together with neoagarobiose hydrolase (NABH) are important key enzymes for the sequential hydrolysis reactions. In this study, a bifunctional endo/exo-agarase was fused with NABH for production of mono-sugars (D-galactose and 3,6-anhydro-L-galactose) from agar using only one fusion enzyme. Two fusion enzymes with either bifunctional agarase (Sco3476) or NABH (Zg4663) at the N-terminus, Sco3476-Zg4663 (SZ) and Zg4663-Sco3476 (ZS), were constructed. Both fusion enzymes exhibited their optimal agarase and NABH activities at 40 and 35 °C, respectively. Fusions SZ and ZS enhanced the thermostability of the NABH activity, while only fusion SZ showed a slight enhancement in the NABH catalytic efficiency (K cat/K M) from 14.8 (mg/mL)(-1) s(-1) to 15.8 (mg/mL)(-1) s(-1). Saccharification of agar using fusion SZ resulted in 2-fold higher mono-sugar production and 3-fold lower neoagarobiose accumulation when compared to the physical mixture of Sco3476 and Zg4663. Therefore, this fusion has the potential to reduce enzyme production cost, decrease intermediate accumulation, and increase mono-sugar yield in agar saccharification.

  10. Ion transport of Fr nuclear reaction products

    SciTech Connect

    Behr, J.A.; Cahn, S.B.; Dutta, S.B.

    1993-04-01

    Experiments planned for fundamental studies of radioactive atoms in magneto-optic traps require efficient deceleration and transport of nuclear reaction products to energies and locations where they can be trapped. The authors have built a low-energy ion transport system for Francium and other alkalis. A thick Au target is held on a W rod at 45{degrees} to the accelerator beam direction. The heavy-ion fusion reaction 115 MeV {sup 18}O + {sup 197}Au produces {sup 211,210,209}Fr recoil products which are stopped in the target. The target is heated to close to the melting point of Au to allow the Fr to diffuse to the surface, where it is ionized due to Au`s high work function, and is directly extracted by an electrode at 90{degrees} to the accelerator beam direction. The Fr is transported by electrostatic optics {approximately}1 m to a catcher viewed by an {alpha} detector: {ge}15% of the Fr produced in the target reaches the catcher. 2{times}10{sup 5} Fr/sec have been produced at the catcher, yielding at equilibrium a sample of 3x10{sup 7}Fr nuclei. This scheme physically decouples the target diffusion from the surface neutralization process, which can occur at a lower temperature more compatible with the neutral-atom trap.

  11. The cytoplasmic domain of the gamete membrane fusion protein HAP2 targets the protein to the fusion site in Chlamydomonas and regulates the fusion reaction

    PubMed Central

    Liu, Yanjie; Pei, Jimin; Grishin, Nick; Snell, William J.

    2015-01-01

    Cell-cell fusion between gametes is a defining step during development of eukaryotes, yet we know little about the cellular and molecular mechanisms of the gamete membrane fusion reaction. HAP2 is the sole gamete-specific protein in any system that is broadly conserved and shown by gene disruption to be essential for gamete fusion. The wide evolutionary distribution of HAP2 (also known as GCS1) indicates it was present in the last eukaryotic common ancestor and, therefore, dissecting its molecular properties should provide new insights into fundamental features of fertilization. HAP2 acts at a step after membrane adhesion, presumably directly in the merger of the lipid bilayers. Here, we use the unicellular alga Chlamydomonas to characterize contributions of key regions of HAP2 to protein location and function. We report that mutation of three strongly conserved residues in the ectodomain has no effect on targeting or fusion, although short deletions that include those residues block surface expression and fusion. Furthermore, HAP2 lacking a 237-residue segment of the cytoplasmic region is expressed at the cell surface, but fails to localize at the apical membrane patch specialized for fusion and fails to rescue fusion. Finally, we provide evidence that the ancient HAP2 contained a juxta-membrane, multi-cysteine motif in its cytoplasmic region, and that mutation of a cysteine dyad in this motif preserves protein localization, but substantially impairs HAP2 fusion activity. Thus, the ectodomain of HAP2 is essential for its surface expression, and the cytoplasmic region targets HAP2 to the site of fusion and regulates the fusion reaction. PMID:25655701

  12. The cytoplasmic domain of the gamete membrane fusion protein HAP2 targets the protein to the fusion site in Chlamydomonas and regulates the fusion reaction.

    PubMed

    Liu, Yanjie; Pei, Jimin; Grishin, Nick; Snell, William J

    2015-03-01

    Cell-cell fusion between gametes is a defining step during development of eukaryotes, yet we know little about the cellular and molecular mechanisms of the gamete membrane fusion reaction. HAP2 is the sole gamete-specific protein in any system that is broadly conserved and shown by gene disruption to be essential for gamete fusion. The wide evolutionary distribution of HAP2 (also known as GCS1) indicates it was present in the last eukaryotic common ancestor and, therefore, dissecting its molecular properties should provide new insights into fundamental features of fertilization. HAP2 acts at a step after membrane adhesion, presumably directly in the merger of the lipid bilayers. Here, we use the unicellular alga Chlamydomonas to characterize contributions of key regions of HAP2 to protein location and function. We report that mutation of three strongly conserved residues in the ectodomain has no effect on targeting or fusion, although short deletions that include those residues block surface expression and fusion. Furthermore, HAP2 lacking a 237-residue segment of the cytoplasmic region is expressed at the cell surface, but fails to localize at the apical membrane patch specialized for fusion and fails to rescue fusion. Finally, we provide evidence that the ancient HAP2 contained a juxta-membrane, multi-cysteine motif in its cytoplasmic region, and that mutation of a cysteine dyad in this motif preserves protein localization, but substantially impairs HAP2 fusion activity. Thus, the ectodomain of HAP2 is essential for its surface expression, and the cytoplasmic region targets HAP2 to the site of fusion and regulates the fusion reaction.

  13. A charged fusion product diagnostic for a spherical tokamak

    NASA Astrophysics Data System (ADS)

    Perez, Ramona Leticia Valenzuela

    Designs for future nuclear fusion power reactors rely on the ability to create a stable plasma (hot ionized gas of hydrogen isotopes) as a medium with which to sustain nuclear fusion reactions. My dissertation work involves designing, constructing, testing, installing, operating, and validating a new diagnostic for spherical tokamaks, a type of reactor test facility. Through detecting charged particles emitted from the plasma, this instrument can be used to study fusion reaction rates within the plasma and how they are affected by plasma perturbations. Quantitatively assessing nuclear fusion reaction rates at specific locations inside the plasma and as a function of time can provide valuable data that can be used to evaluate theory-based simulations related to energy transport and plasma stability. The Proton Detector (PD), installed in the Mega Amp Spherical Tokamak (MAST) at the Culham Centre for Fusion Energy (CCFE) in Abingdon, England, was the first instrument to experimentally detect 3 MeV Protons and 1 MeV Tritons created from deuterium- deuterium (hydrogen isotopes) nuclear fusion reactions inside a spherical tokamak's plasma. The PD consists of an array of particle detectors with a protective housing and the necessary signal conditioning electronics and readout. After several years of designing (which included simulations for detector orientations), fabricating, and testing the PD, it was installed in MAST and data were collected over a period of two months in the summer of 2013. Proton and triton rates as high as 200 kHz were measured and an initial radial profile of these fusion reaction rates inside the plasma was extracted. These results will be compared to a complementary instrument at MAST as well as theory-based simulations and form the knowledge basis for developing a larger future instrument. The design and performance of all instrument components (electrical, computational, mechanical), and subsequent data analysis methods and results are

  14. Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

    SciTech Connect

    Wang Ning; Scheid, Werner; Wu Xizhen; Liu Min; Li Zhuxia

    2006-10-15

    The Skyrme energy-density functional approach has been extended to study massive heavy-ion fusion reactions. Based on the potential barrier obtained and the parametrized barrier distribution the fusion (capture) excitation functions of a lot of heavy-ion fusion reactions are studied systematically. The average deviations of fusion cross sections at energies near and above the barriers from experimental data are less than 0.05 for 92% of 76 fusion reactions with Z{sub 1}Z{sub 2}<1200. For the massive fusion reactions, for example, the {sup 238}U-induced reactions and {sup 48}Ca+{sup 208}Pb, the capture excitation functions have been reproduced remarkably well. The influence of structure effects in the reaction partners on the capture cross sections is studied with our parametrized barrier distribution. By comparing the reactions induced by double-magic nucleus {sup 48}Ca and by {sup 32}S and {sup 35}Cl, the ''threshold-like'' behavior in the capture excitation function for {sup 48}Ca-induced reactions is explored and an optimal balance between the capture cross section and the excitation energy of the compound nucleus is studied. Finally, the fusion reactions with {sup 36}S, {sup 37}Cl, {sup 48}Ca, and {sup 50}Ti bombarding {sup 248}Cm, {sup 247,249}Bk, {sup 250,252,254}Cf, and {sup 252,254}Es, as well as the reactions leading to the same compound nucleus with Z=120 and N=182, are studied further. The calculation results for these reactions are useful for searching for the optimal fusion configuration and suitable incident energy in the synthesis of superheavy nuclei.

  15. Calculations of Proton Emission Cross Sections in Deuteron Induced Reactions of Some Fusion Structural Materials

    NASA Astrophysics Data System (ADS)

    Yiğit, M.; Tel, E.; Tanır, G.

    2013-06-01

    The growing demands for energy consumption have led to the increase of the research and development activities on new energy sources. Fusion energy has the highest potential to become a very safe, clean and abundant energy source for the future. To get energy from fusion are needed for development of fusion reactor technology. Particularly, the design and development of international facilities as International Thermonuclear Experimental Reactor and International Fusion Material Irradiation Facility requires for the cross-section data of deuteron induced reactions. Moreover, the selection of fusion structural materials are an indispensable component for this technology. Therefore, the cross-section data of deuteron induced reactions on fusion structural materials are of great importance for development of fusion reactor technology. In this study, reaction model calculations of the cross sections of deuteron induced reactions on structural fusion materials such as 27Al, 59Co, 55Mn, 50Cr, 54Cr, 64Ni, 109Ag, 184W and 186W have been carried out for incident energies up to 50 MeV. In these calculations, the pre-equilibrium and equilibrium effects for ( d, p) stripping reactions have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model and hybrid model. Equilibrium effects are calculated according to the Weisskopf-Ewing model. In the calculations the program code ALICE/ASH was used. The calculated results are discussed and compared with the experimental data taken from the literature.

  16. Discriminating Acquisition of 15-MeV Protons from D-3He Fusion Reaction in LHD

    NASA Astrophysics Data System (ADS)

    Watanabe, Tsuguhiro; Miyazawa, Junichi; Yamada, Hiroshi; Murakami, Sadayoshi; Masuzaki, Suguru; Osakabe, Masaki; Isobe, Mitsutaka; Tokitani, Masayuki; Motojima, Osamu

    Discriminating acquisition of 15-MeV protons is possible in LHD D-3He experiments (D+ beam to 3He plasma), due to the nonaxisymmetric structure of the magnetic field and the ultra-high energy of the fusion products. The collisionless orbits of D-3He fusion products are studied numerically in the standard magnetic field configuration of LHD. Three sets of fusion product acquisition systems are installed in LHD and numerical computations show the possibility of discriminating between fusion products and plasma particles. The acquisition rate of 15-MeV protons is expected to be in the range of 12 ˜ 28 %.

  17. ConnesFusionTensorProduct/Photon GluonFusion in Mitochondria

    NASA Astrophysics Data System (ADS)

    Wh-Maksoed, Prodi Of Physics Ui, Depok 16415-Indonesia; Ssi, Wh-Maksoed

    2016-05-01

    As in AJ Wassermann distinguished of classical invariant theory & quantum invariant theory subfactor, in S. Palcoux:``From Neveu-Schwarz Subfactors & Connes Fusion'' described the subfactor theory & Witt-algebra whereas Andreas Thom's explanation about ConnesFusionTensorProduct/CFTP related Connes fusion to composition of homomorphism (i). classical tensor product O-X adds the changes,(ii). Relative tensor product H-X preserve the changes. For photonGluonFusion/PGF defined:''photon is the gauge boson of QED, the simplest of all boson'' devotes to CFT as ``quantum field theory which are invariant under conformal transformation & in 2D there are infinite dimensional algebra. Alain Connes states theirselves Connes fusion as ``associative tensor operation'' to be in coincidences with ``their dynamic behavior driven by the balance in mitochondrial fusion & fission (Carveney, 2007) from Peter Alexander Williams: ``Retinal neuronal remodeling in a model of Optic Atrophy'', Dec, 2011. Great acknowledged to the VicePresident of the R.I, HE.Mr. Drs. M. JUSUF KALLA.

  18. Possibilities for synthesis of new isotopes of superheavy nuclei in cold fusion reactions

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Gao, Y.; Li, J. Q.; Zhang, H. F.

    2016-04-01

    In order to find a way to produce superheavy nuclei (SHN), which appear in the gap between the SHN synthesized by cold fusion and those by hot fusion, or those so far not yet been produced in the laboratory, we tried to make use of a set of projectile isotopic chains, to use a radioactive beam projectile, and to test symmetric fusion reactions for gaining more neutrons to synthesize neutron-richer SHN based on the dinuclear system (DNS) model via cold fusion reactions. It is found that the nuclei 265Mt,Ds,272268,273Rg, and 274,275,276Cn may be produced with the detectable evaporation residual cross sections. The intensities of radioactive beams are significantly less than those of the stable beams, therefore using a stable beam is predicted to be the most favorable method for producing SHN. From the symmetric reaction system 136Xe+136Xe , no fusion event was found.

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

    SciTech Connect

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.; Chan, A.A.; England, A.C.; Hendel, H.W.; Medley, S.S.; Nieschmidt, E.; Roquemore, A.L.; Scott, S.D.

    1986-04-01

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

  20. Fusion and quasifission studies in reactions forming Rn via evaporation residue measurements

    NASA Astrophysics Data System (ADS)

    Shamlath, A.; Prasad, E.; Madhavan, N.; Laveen, P. V.; Gehlot, J.; Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Nath, S.; Banerjee, Tathagata; Vinodkumar, A. M.; Shareef, M.; Jhingan, A.; Varughese, T.; Kumar, Dvgrks; Devi, P. Sandya; Khushboo, Jisha, P.; Kumar, Neeraj; Hosamani, M. M.; Kailas, S.

    2017-03-01

    Background: Formation of the compound nucleus (CN) is highly suppressed by quasifission in heavy-ion collisions involving massive nuclei. Though considerable progress has been made in the understanding of fusion-fission and quasifission, the exact dependence of fusion probability on various entrance channel variables is not completely clear, which is very important for the synthesis of new heavy and superheavy elements. Purpose: To study the interplay between fusion and quasifission in reactions forming CN in the boundary region where the fusion probability starts to deviate from unity. Methods: Fusion evaporation residue cross sections were measured for the Si,3028+180Hf reactions using the Hybrid Recoil Mass Analyser at IUAC, New Delhi. Experimental data were compared with data from other reactions forming the same CN or isotopes of the CN. Theoretical calculations were performed using the dinuclear system and statistical models. Results: Reduced evaporation residue cross sections were observed for the reactions studied compared with the asymmetric reaction forming the same CN, indicating fusion suppression in more symmetric systems. The observations are consistent with fission fragment measurements performed in the same or similar systems. Larger ER cross sections are observed with increase in mass in the isotopic chain of the CN. Conclusions: Fusion probability varies significantly with the entrance channels in reactions forming the same CN. While complete fusion occurs for the 16O+194Pt reaction, the fusion probability drops to approximately 60 -70 % for the 30Si+180Hf and less than 20 % for the 50Ti+160Gd reactions, respectively, forming the same CN at similar excitation energies.

  1. Production of specific antibodies against protein A fusion proteins.

    PubMed Central

    Löwenadler, B; Nilsson, B; Abrahmsén, L; Moks, T; Ljungqvist, L; Holmgren, E; Paleus, S; Josephson, S; Philipson, L; Uhlén, M

    1986-01-01

    The gene for Staphylococcal protein A was fused to the coding sequence of bacterial beta-galactosidase, alkaline phosphatase and human insulin-like growth factor I (IGF-I). The fusion proteins, expressed in bacteria, were purified by affinity chromatography on IgG-Sepharose and antibodies were raised in rabbits. All three fusion proteins elicited specific antibodies against both the inserted protein sequences and the protein A moiety. In the case of IGF-I, the protein A moiety in the fusion protein may act as an adjuvant since native IGF-I alone is a poor immunogen. The results suggest that the protein A fusion system can be used for efficient antibody production against peptides or proteins expressed from cloned or synthetic genes. To facilitate such gene fusions a set of optimized vectors have been constructed. Images Fig. 2. Fig. 3. Fig. 4. Fig. 6. PMID:3096719

  2. Microscopic dynamics simulations of heavy-ion fusion reactions induced by neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Ou, Li; Zhang, Yingxun; Li, Zhuxia

    2014-06-01

    The heavy-ion fusion reactions induced by neutron-rich nuclei are investigated with the improved quantum molecular dynamics (ImQMD) model. With a subtle consideration of the neutron skin thickness of nuclei and the symmetry potential, the stability of nuclei and the fusion excitation functions of heavy-ion fusion reactions O16 + Ge76, O16 + Sm154, Ca40 + Zr96, and Sn132 + Ca40 are systematically studied. The fusion cross sections of these reactions at energies around the Coulomb barrier can be well reproduced by using the ImQMD model. The corresponding slope parameter of the symmetry energy adopted in the calculations is L ≈78 MeV and the surface energy coefficient is gsur=18±1.5 MeV fm2. In addition, it is found that the surface-symmetry term significantly influences the fusion cross sections of neutron-rich fusion systems. For sub-barrier fusion, the dynamical fluctuations in the densities of the reaction partners and the enhanced surface diffuseness at neck side result in the lowering of the fusion barrier.

  3. Transfer/Breakup Channel Couplings in Sub-barrier Fusion Reactions

    NASA Astrophysics Data System (ADS)

    Beck, C.

    2013-03-01

    With the recent availability of state-of-the-art radioactive ion beams, there has been a renew interest in the investigation of nuclear reactions with heavy ions near the Coulomb barrier. The role of inelastic and transfer channel couplings in fusion reactions induced by stable heavy ions can be revisited. Detailed analysis of recent experimental fusion cross sections by using standard coupled-channel calculations is first discussed. Multi-neutron transfer effects are introduced in the fusion process below the Coulomb barrier by analyzing 32S+90,96Zr as benchmark reactions. The enhancement of fusion cross sections for 32S+96Zr is well reproduced at sub-barrier energies by NTFus code calculations including the coupling of the neutrontransfer channels following the Zagrebaev semi-classical model. Similar effects for 40Ca+90Zr and 40Ca+96Zr fusion excitation functions are found. The breakup coupling in both the elastic scattering and in the fusion process induced by weakly bound stable projectiles is also shown to be crucial. In the second part of this work, full coupled-channel calculations of the fusion excitation functions are performed by using the breakup coupling for the more neutron-rich reaction and for the more weakly bound projectiles. We clearly demonstrate that Continuum-Discretized Coupled-Channel calculations are capable to reproduce the fusion enhancement from the breakup coupling in 6Li+59Co.

  4. Fusion, reaction, and breakup cross sections of {sup 9}Be on a light mass target

    SciTech Connect

    Marti, G.V.; Capurro, O.A.; Pacheco, A.J.; Testoni, J.E.; Ramirez, M.; Arazi, A.; Gomes, P.R.S.; Padron, I.; Anjos, R.M.; Lubian, J.; Crema, E.

    2005-02-01

    The total fusion cross section for the {sup 9}Be+{sup 27}Al system has been measured at energies close and above the Coulomb barrier. Reaction cross sections for this system were derived from elastic scattering data, and the breakup-plus-transfer-channel cross sections were estimated from the difference between these data and measured cross-section fusion.

  5. Reaction products of chlorine dioxide.

    PubMed Central

    Stevens, A A

    1982-01-01

    Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

  6. Upgrade of the IGN-14 neutron generator for research on detection of fusion-plasma products

    NASA Astrophysics Data System (ADS)

    Igielski, Andrzej; Kurowski, Arkadiusz; Janik, Władysław; Gabańska, Barbara; Woźnicka, Urszula

    2015-10-01

    The fast neutron generator (IGN-14) at the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Kraków (Poland) is a laboratory multi-purpose experimental device. Neutrons are produced in a beam-target D-D or D-T reactions. A new vacuum chamber installed directly to the end of the ion guide of IGN-14 makes it possible to measure not only neutrons but also alpha particles in the presence of a mixed radiation field of other accompanying reaction products. The new experimental setup allows test detectors dedicated to spectrometric measurements of thermonuclear fusion reaction products.

  7. Transmutation of high-level fission products and actinides in a laser-driven fusion reactor

    SciTech Connect

    Basov, N.; Rozanov, V.B. ); Belousov, N.I.; Grishunin, P.A.; Kharitonov, V.V. ); Subbotin, V.I. )

    1992-11-01

    Incineration of [sup 90]Sr and [sup 137]Cs b thermal or fast neutrons is a very difficult problem. A 14-MeV neutron source based on intertial confinement fusion is a more appropriate choice. For the first time, the contribution of the (n,2n) reaction to incineration is revealed. The energy and nuclei balance for a system of several nuclear power plants and a fusion reactor for transmutation is analyzed. If the fusion reactor supports a sufficient number of nuclear power plants, it need not produce energy or tritium. Target and blanket material problems are considered. This paper reports that laser fusion incinerator has the best prospects because of its fast neutron spectrum and high driver efficiency by target gain product.

  8. Fusion-fission and quasifission in the reactions with heavy ions leading to the formation of Hs

    SciTech Connect

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

    2012-10-20

    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 leading to Hs isotopes have been measured. At energies below the Coulomb barrier the bimodal fission of Hs*, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed. In the reaction {sup 36}S+{sup 238}U the considerable part of the symmetric fragments arises from the quasifission process. At energies above the Coulomb barrier the symmetric fragments originate mainly from fusion-fission process 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. The pre- and post-scission neutron multiplicities as a function of the fragment mass have been obtained for the reactions studied.

  9. Immediate reactions to rubber products.

    PubMed

    Fuchs, T; Wahl, R

    1992-01-01

    There is an increasing incidence of contact urticaria (CU) and systemic reactions to rubber products. Thirty-one patients are presented: most were atopic (20/31) and women (26/31); 71% worked in the medical field; 32.2% (10/31) showed signs of hand dermatitis. In 28 patients (90.3%), rub and/or prick tests with liquid latex in different dilutions and with latex gloves led to an immediate type of positive reaction. The allergen(s) appear in part to be water soluble: 20 of 28 patients (71.4%) revealed positive test reactions to an aqueous glove extract. In two patients, urticarial test reactions to tetramethylthiuram disulfide (TMTD), mercapto mix, and p-phenylenediamine (PPD mix) were considered as possible contributing factors of CU. Cornstarch was negative in all patients (scratch). Sixteen of 27 sera (59.2%) showed radioallergosorbent (RAST) class 0 using latex allergen disks. Sodium dodecyl sulfate-polyacoyl-amide (SDS-PAGE) determined protein bands of less than or equal to 14 kD (not allergen specific) and approx 28 kD. The Western blot detected the 28 kD protein as allergen in the sera of three patients. Isoelectric focusing (IEF) proved no protein bands. Immunoprinting performed with sera of five patients presented allergen bands in a pH range between 3.8 and 4.55. This shows the radio staining (immunoprint) is more sensitive than is the Coomassie blue staining. Although three sera showed RAST class 0, immunoblotting detected allergen bands. In this case the immunoblot appears to be more sensitive than the RAST. A cross reactivity between latex and banana could not be established. Alternative gloves are Neolon (neoprene) or Elastyren (styrene-butadiene polymer).

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

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

    PubMed

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

    2013-01-01

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

  12. 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.

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

    NASA Astrophysics Data System (ADS)

    Gatu Johnson, M.; Zylstra, A. B.; Bacher, A.; Brune, C. R.; Casey, D. T.; Forrest, C.; Herrmann, H. W.; Hohenberger, M.; Sayre, D. B.; Bionta, R. M.; Bourgade, J.-L.; Caggiano, J. A.; Cerjan, C.; Craxton, R. S.; Dearborn, D.; Farrell, M.; Frenje, J. A.; Garcia, E. M.; Glebov, V. Yu.; Hale, G.; Hartouni, E. P.; Hatarik, R.; Hohensee, M.; Holunga, D. M.; Hoppe, M.; Janezic, R.; Khan, S. F.; Kilkenny, J. D.; Kim, Y. H.; Knauer, J. P.; Kohut, T. R.; Lahmann, B.; Landoas, O.; Li, C. K.; Marshall, F. J.; Masse, L.; McEvoy, A.; McKenty, P.; McNabb, D. P.; Nikroo, A.; Parham, T. G.; Paris, M.; Petrasso, R. D.; Pino, J.; Radha, P. B.; Remington, B.; Rinderknecht, H. G.; Robey, H.; Rosenberg, M. J.; Rosse, B.; Rubery, M.; Sangster, T. C.; Sanchez, J.; Schmitt, M.; Schoff, M.; Séguin, F. H.; Seka, W.; Sio, H.; Stoeckl, C.; Tipton, R. E.

    2017-04-01

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

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

    DOE PAGES

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

    2017-03-28

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

  15. Studies of Neutron-Deficient Nuclei Near the Z = 82 Shell Closure via Cold Fusion Reactions

    SciTech Connect

    Carpenter, M. P.; Kondev, F. G.; Janssens, R. V. F.; Seweryniak, D.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Zhu, S.; Camera, F.; Bracco, A.; Million, B.; Leoni, S.; Jenkins, D. G.; Wadsworth, R.

    2009-03-04

    Over the last decade, we have performed in-beam experiments using Gammasphere+FMA to measure excited states in proton-rich Au, Hg, Tl and Pb isotopes. In these studies, the use of the FMA is essential in order to differentiate evaporation residues from the large fission background which dominates the reaction cross-section. In addition, we have found that using near-symmetric reactions at bombarding energies near the Coloumb barrier is beneficial in performing these studies. By keeping the bombarding energy low, fission is minimized and the reaction products are concentrated in only a few channels. New results have recently been obtained using the {sup 90}Zr+{sup 92}Mo reaction to study shape co-existence in {sup 181}Tl via the lp evaporation channel. In addition, we have measured the total {gamma}-ray energy and multiplicity associated with the surviving compound system, {sup 179}Au, following the fusion reaction, {sup 90}Zr+{sup 89}Y.

  16. Attempt to produce the isotopes of element 108 in the fusion reaction {sup 136}Xe+{sup 136}Xe

    SciTech Connect

    Oganessian, Yu. Ts.; Dmitriev, S. N.; Yeremin, A. V.; Aksenov, N. V.; Bozhikov, G. A.; Chepigin, V. I.; Chelnokov, M. L.; Lebedev, V. Ya.; Malyshev, O. N.; Petrushkin, O. V.; Shishkin, S. V.; Svirikhin, A. I.; Tereshatov, E. E.; Vostokin, G. K.

    2009-02-15

    A setup of the experiment on the production of the isotopes with Z=108 in the fusion reaction {sup 136}Xe+{sup 136}Xe and the obtained results are presented. At the excitation energy 0{<=}E{sub x}{<=}30 MeV of the {sup 272}Hs* compound nucleus the upper limit of the cross section for evaporation residues {sigma}{sub (1-3)n}{<=}4 pb has been measured. The experimental results together with the data from asymmetric reactions point to a strong limitation of the Hs compound nucleus formation with increasing Coulomb forces in the entrance channel of the reaction.

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

    NASA Astrophysics Data System (ADS)

    Schneider, M.; Johnson, T.; Dumont, R.; Eriksson, J.; Eriksson, L.-G.; Giacomelli, L.; Girardo, J.-B.; Hellsten, T.; Khilkevitch, E.; Kiptily, V. G.; Koskela, T.; Mantsinen, M.; Nocente, M.; Salewski, M.; Sharapov, S. E.; Shevelev, A. E.; Contributors, JET

    2016-11-01

    Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 (3He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) of the beam. This scenario generates a fast ion deuterium tail enhancing DD and D3He fusion reactions. Modelling and measuring the fast deuterium tail accurately is essential for quantifying the fusion products. This paper presents the modelling of the D distribution function resulting from the NBI+ICRF heating scheme, reinforced by a comparison with dedicated JET fast ion diagnostics, showing an overall good agreement. Finally, a sawtooth activity for these experiments has been observed and interpreted using SPOT/RFOF simulations in the framework of Porcelli’s theoretical model, where NBI+ICRH accelerated ions are found to have a strong stabilizing effect, leading to monster sawteeth.

  18. Cold fusion reaction of 58Fe + 208Pb analyzed by a generalized model of fusion by diffusion

    NASA Astrophysics Data System (ADS)

    Liu, Zu-Hua; Bao, Jing-Dong

    2012-05-01

    A generalized version of the fusion by diffusion model is proposed, in which evolution from dinuclear to mononuclear regimes is taken into account in terms of the coupled Langevin equations in the three-dimensional collective space of neck, radial, and asymmetric degrees of freedom. By simulating numerically these dynamic equations, the probability distribution of sinj, the separation between the surfaces of two approaching nuclei at the injection point in the asymmetric fission valley, is obtained. From the injection points, the system starts its climb uphill over the saddle point in the presence of thermal fluctuation; thus for very heavy systems the injection-point distance is a very critical constituent in the calculations of fusion probability. The present model is applied for the study of the mass asymmetric system 58Fe+208Pb. The excitation function for the 208Pb(58Fe,n)265Hs reaction is calculated and compared with the experimental data. By comparing the theoretical results with and without taking the asymmetric degree of freedom into account, we have arrived at the conclusion that nucleon flow between the asymmetric reaction partners in the early stage of the fusion process plays an important role in the formation of superheavy nuclei in the cold fusion reactions.

  19. Measurements of fusion reactions of low-intensity radioactive carbon beams on 12C and their implications for the understanding of X-ray bursts.

    PubMed

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

    2014-05-16

    The interaction between neutron-rich nuclei plays an important role for understanding the reaction mechanism of the fusion process as well as for the energy production through pycnonuclear reactions in the crust of neutron stars. We have performed the first measurements of the total fusion cross sections in the systems (10,14,15)C+(12)C using a new active target-detector system. In the energy region accessible with existing radioactive beams, a good agreement between the experimental and theoretical cross sections is observed. This gives confidence in our ability to calculate fusion cross sections for systems which are outside the range of today's radioactive beam facilities.

  20. Measurements of Fusion Reactions of Low-Intensity Radioactive Carbon Beams on C12 and their Implications for the Understanding of X-Ray Bursts

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    The interaction between neutron-rich nuclei plays an important role for understanding the reaction mechanism of the fusion process as well as for the energy production through pycnonuclear reactions in the crust of neutron stars. We have performed the first measurements of the total fusion cross sections in the systems C10,14,15+C12 using a new active target-detector system. In the energy region accessible with existing radioactive beams, a good agreement between the experimental and theoretical cross sections is observed. This gives confidence in our ability to calculate fusion cross sections for systems which are outside the range of today's radioactive beam facilities.

  1. Comparative analysis of the fusion reactions 48Ti+58Fe and 58Ni+54Fe

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

    The experimental fusion excitation functions of the reactions 48Ti+58Fe and 58Ni+54Fe , measured down to the low sub-barrier energies, are described within the quantum diffusion approach and the universal fusion function representation. For these systems, the s -wave capture probabilities are extracted from the experimental excitation functions and are also analyzed. An enhancement of the sub-barrier fusion cross section observed in the 48Ti+58Fe reaction in comparison to the relatively close system 58Ni+54Fe is explained.

  2. Observation of d-3He Fusion Reactions in a Tokamak Plasma

    NASA Astrophysics Data System (ADS)

    Chrien, R. E.; Colestock, P. L.; Eubank, H. P.; Hosea, J. C.; Hwang, D. Q.; Strachan, J. D.; Thompson, H. R., Jr.

    1981-02-01

    d-3He reactions have been observed in the Princeton Large Torus by detecting the unconfined 14.7-MeV proton. Reaction rates as high as 2×1013 sec-1 resulting in 60 W of fusion power were obtained by 500-kW heating of a 3He minority in the ion-cyclotron range of frequencies to energies above 80 keV. The fusion-power multiplication of about 10-4 is equal to the highest obtained in any controlled-fusion experiment.

  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. Fusion Reactions and Matter-Antimatter Annihilation for Space Propulsion

    DTIC Science & Technology

    2005-07-13

    Wittenberg, J.F. Santarius and G . Kulcinski , Lunar Source of He-3 for commercial fusion power, Fusion Technology 10, 167 (1986). [5] E. Stuhlinger...Nature, 258, 512 (1975). [13] J. Nuckolls, A. Thiessen, L . Wood and G . Zimmermann, Laser compression of matter to super high densities, Nature, 239...of rocket system to carry out each of these missions can be calculated from the rocket equation R = mv + m p m v = e∆V / vex = e ∆V / g Isp ^ , [1

  5. 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.

  6. Proliferation Risks of Fusion Energy: Clandestine Production, Covert Production, and Breakout

    SciTech Connect

    R.J. Goldston, A. Glaser, A.F. Ross

    2009-08-13

    Nuclear proliferation risks from fusion associated with access to weapon-usable material can be divided into three main categories: 1) clandestine production of fissile material in an undeclared facility, 2) covert production of such material in a declared and safeguarded facility, and 3) use of a declared facility in a breakout scenario, in which a state begins production of fissile material without concealing the effort. In this paper we address each of these categories of risk from fusion. For each case, we find that the proliferation risk from fusion systems can be much lower than the equivalent risk from fission systems, if commercial fusion systems are designed to accommodate appropriate safeguards.

  7. Role of Barrier Modification and Nuclear Structure Effects in Sub-Barrier Fusion Dynamics of Various Heavy Ion Fusion Reactions

    NASA Astrophysics Data System (ADS)

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

    2017-10-01

    The role of barrier modifications and the relevant nuclear structure effects in the fusion of the {}_8{}^{16}O+{}_{62}{}^{144,148,150,152,154}Sm and {}_3{}^{6,7}Li+{}_{62}{}^{152}Sm systems is analyzed within the context of the energy-dependent Woods-Saxon potential model (EDWSP model) and the coupled channel model. For the {}_8{}^{16}O+{}_{62}{}^{144,148,150,152,154}Sm reactions, where the colliding pairs are stable against breakup, the collective excitations and/or static deformations are sufficient to account for the observed fusion enhancement. In contrast, the model calculations overpredict the complete fusion data at above - barrier energies for the {}_3{}^{6,7}Li+{}_{62}{}^{152}Sm systems, where the importance of projectile breakup effects has been pointed out. Due to the low threshold of the alpha-breakup channel, the weakly bound projectiles ({}_3{}^{6,7}Li) break up into charged fragments before reaching the fusion barrier and consequently the complete fusion cross section is suppressed by 28% (25%) in the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction with respect to predictions of coupled channel calculations. However, the EDWSP model based calculations can minimize the suppression factor by as much as of 13% (8%) in the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction with reference to the predictions made by the coupled channel calculations. Therefore, the complete fusion data of the {}_3{}^6Li+{}_{62}{}^{152}Sm({}_3{}^7Li+{}_{62}{}^{152}Sm) reaction at above - barrier energies is reduced by 15% (17%) with respect to the expectations of the EDWSP model. The extracted suppression factors for the studied reactions are due to the modifications of the barrier profile as a consequence of the energy - dependence in nucleus-nucleus potential, and thus greater barrier modifications occur for more weakly bound system, which in turn, confirms the breakup of projectile in the incoming channel.

  8. Fusion-product transport in axisymmetric tokamaks: losses and thermalization

    SciTech Connect

    Hively, L.M.

    1980-01-01

    High-energy fusion-product losses from an axisymmetric tokamak plasma are studied. Prompt-escape loss fluxes (i.e. prior to slowing down) are calculated including the non-separable dependence of flux as a function of poloidal angle and local angle-of-incidence at the first wall. Fusion-product (fp) thermalization and heating are calculated assuming classical slowing down. The present analytical model describes fast ion orbits and their distribution function in realistic, high-..beta.., non-circular tokamak equilibria. First-orbit losses, trapping effects, and slowing-down drifts are also treated.

  9. Demazure Modules, Chari-Venkatesh Modules and Fusion Products

    NASA Astrophysics Data System (ADS)

    Ravinder, Bhimarthi

    2014-12-01

    Let g be a finite-dimensional complex simple Lie algebra with highest root θ. Given two non-negative integers m, n, we prove that the fusion product of m copies of the level one Demazure module D(1,θ) with n copies of the adjoint representation ev_0 V(θ) is independent of the parameters and we give explicit defining relations. As a consequence, for g simply laced, we show that the fusion product of a special family of Chari-Venkatesh modules is again a Chari-Venkatesh module. We also get a description of the truncated Weyl module associated to a multiple of θ.

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

    NASA Astrophysics Data System (ADS)

    Hagino, K.; Rowley, N.; Yao, J. M.

    2016-06-01

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

  11. Application of immobilized bovine enterokinase in repetitive fusion protein cleavage for the production of mucin 1.

    PubMed

    Kubitzki, Tina; Minör, Daniel; Mackfeld, Ursula; Oldiges, Marco; Noll, Thomas; Lütz, Stephan

    2009-11-01

    Bovine enterokinase is a serine protease that catalyzes the hydrolysis of peptide bonds and plays a key role in mammalian metabolism. Because of its high specificity towards the amino acid sequence (Asp)(4)-Lys, enterokinase is a potential tool for the cleavage of fusion proteins, which are gaining more importance in biopharmaceutical production. A candidate for adaptive cancer immunotherapy is mucin 1, which is produced recombinantly as a fusion protein in CHO cells. Here, we present the first repetitive application of immobilized enterokinase for the cleavage of the mucin fusion protein. The immobilization enables a facile biocatalytic process due to simplified separation of the biocatalyst and the target protein. Immobilized enterokinase was applied in a maximum of 18 repetitive reactions. The enzyme utilization (total turnover number) was increased significantly 419-fold compared to unbound enzyme by both immobilization and optimization of process conditions. Slight enzyme inactivation throughout the reaction cycles was observed, but was compensated by adjusting the process time accordingly. Thus, complete fusion protein cleavage was achieved. Furthermore, we obtained isolated mucin 1 with a purity of more than 90% by applying a simple and efficient purification process. The presented results demonstrate enterokinase to be an attractive tool for fusion protein cleavage.

  12. Revised analysis of Ca40+Zr96 fusion reactions

    DOE PAGES

    Esbensen, H.; Montagnoli, G.; Stefanini, A. M.

    2016-03-10

    Fusion data for 40Ca + 96Zr are analyzed by coupled-channels calculations that are based on a standard Woods-Saxon potential and include couplings to multiphonon excitations and transfer channels. The couplings to multiphonon excitations are the same as those used in a previous work. The transfer couplings are calibrated to reproduce the measured neutron transfer data. This type of calculation gives a poor fit to the fusion data. However, by multiplying the transfer couplings with a √2 one obtains an excellent fit. Finally, the scaling of the transfer strengths is supposed to simulate the combined effect of neutron and proton transfer,more » and the calculated one- and two-nucleon transfer cross sections are indeed in reasonable agreement with the measured cross sections.« less

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  15. Role of the neck degree of freedom in cold fusion reactions

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    Mass parameters for collective variables of dinuclear systems formed in cold fusion reactions are microscopically calculated with the linear response theory making use of the width of single-particle states and the fluctuation-dissipation theorem. The single-particle spectrum and potential energy surface of the adiabatic two-center shell model are used. The microscopical mass parameter in the neck is found to be much larger than one obtained with the hydrodynamical model. Therefore, the dinuclear system lives a rather long time, comparable to the characteristic time of fusion and, correspondingly, the fusion can be considered at fixed neck parameter. With an adiabatic melting of the dinuclear system along the internuclear distance into a compound system one cannot explain the experimental trends in cold fusion reactions.

  16. Antibody-independent Targeted Quantification of TMPRSS2-ERG Fusion Protein Products in Prostate Cancer

    SciTech Connect

    He, Jintang; Sun, Xuefei; Shi, Tujin; Schepmoes, Athena A.; Fillmore, Thomas L.; Petyuk, Vladislav A.; Xie, Fang; Zhao, Rui; Gritsenko, Marina A.; Yang, Feng; Kitabayashi, Naoki; Chae, Sung Suk; Rubin, Mark; Siddiqui, Javed; Wei, John; Chinnaiyan, Arul M.; Qian, Weijun; Smith, Richard D.; Kagan, Jacob; Srivastava, Sudhir; Rodland, Karin D.; Liu, Tao; Camp, David G.

    2014-10-01

    Fusions between the transmembrane protease serine 2 (TMPRSS2) and ETS related gene (ERG) represent one of the most specific biomarkers that define a distinct molecular subtype of prostate cancer. The studies on TMPRSS2-ERG gene fusions have seldom been performed at the protein level, primarily due to the lack of high-quality antibodies or an antibody-independent method that is sufficiently sensitive for detecting the truncated ERG protein products resulting from TMPRSS2-ERG gene fusions and alternative splicing. Herein, we applied a recently developed PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM (selected reaction monitoring) strategy for quantifying ERG protein in prostate cancer cell lines and tumors. The highly sensitive PRISM-SRM assays led to confident detection of 6 unique ERG peptides in either the TMPRSS2-ERG positive cell lines or tissues but not in the negative controls, indicating that ERG protein expression is highly correlated with TMPRSS2-ERG gene rearrangements. Significantly, our results demonstrated for the first time that at least two groups of ERG protein isoforms were simultaneously expressed at variable levels in TMPRSS2-ERG positive samples as evidenced by concomitant detection of two mutually exclusive peptides. Three peptides shared across almost all fusion protein products were determined to be the most abundant peptides, and hence can be used as “signature” peptides for detecting ERG overexpression resulting from TMPRSS2-ERG gene fusion. These PRISM-SRM assays provide valuable tools for studying TMPRSS2-ERG gene fusion protein products, thus improving our understanding of the role of TMPRSS2-ERG gene fusion in the biology of prostate cancer.

  17. Simulation of a fusion gamma reaction history diagnostic for the Shenguang-III facility

    NASA Astrophysics Data System (ADS)

    Song, Zifeng; Chen, Jiabin; Xu, Tao; Liu, Zhongjie; Zhan, Xiayu; Tang, Qi

    2017-05-01

    The fusion gamma has an advantage to measure fusion reaction history in the deuterium-tritium (DT) fuel implosion experiments. A gas Cherenkov detector is available to measure DT fusion gamma in a high background environment. Simulation is carried out by Geant4 to evaluate the conversion efficiency and the time response of this Cherenkov detector. The background gamma rays are roughly estimated based on ENDF/B-VII.0 data, and the signal-to-noise (SNR) is evaluated based on the simulated energy response curve. The simulation result and the SNR analysis are helpful to construct the Cherenkov detector at Shenguang-III facility.

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

    NASA Astrophysics Data System (ADS)

    Sagaidak, Roman

    2017-09-01

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

  19. Synthesis of transactinide nuclei in cold fusion reactions using radioactive beams

    SciTech Connect

    Smolanczuk, Robert

    2010-06-15

    Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out reactions) using radioactive beams are evaluated. Because in most of the cases intensities of radioactive beams are significantly less than those of the stable beams, reactions with the greatest radioactive-beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland [Phys. Rev. C 76, 014612 (2007)], who investigated the same nuclei.

  20. 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.

  1. An evolved Mxe GyrA intein for enhanced production of fusion proteins.

    PubMed

    Marshall, Carrie J; Grosskopf, Vanessa A; Moehling, Taylor J; Tillotson, Benjamin J; Wiepz, Gregory J; Abbott, Nicholas L; Raines, Ronald T; Shusta, Eric V

    2015-02-20

    Expressing antibodies as fusions to the non-self-cleaving Mxe GyrA intein enables site-specific, carboxy-terminal chemical modification of the antibodies by expressed protein ligation (EPL). Bacterial antibody-intein fusion protein expression platforms typically yield insoluble inclusion bodies that require refolding to obtain active antibody-intein fusion proteins. Previously, we demonstrated that it was possible to employ yeast surface display to express properly folded single-chain antibody (scFv)-intein fusions, therefore permitting the direct small-scale chemical functionalization of scFvs. Here, directed evolution of the Mxe GyrA intein was performed to improve both the display and secretion levels of scFv-intein fusion proteins from yeast. The engineered intein was shown to increase the yeast display levels of eight different scFvs by up to 3-fold. Additionally, scFv- and green fluorescent protein (GFP)-intein fusion proteins can be secreted from yeast, and while fusion of the scFvs to the wild-type intein resulted in low expression levels, the engineered intein increased scFv-intein production levels by up to 30-fold. The secreted scFv- and GFP-intein fusion proteins retained their respective binding and fluorescent activities, and upon intein release, EPL resulted in carboxy-terminal azide functionalization of the target proteins. The azide-functionalized scFvs and GFP were subsequently employed in a copper-free, strain-promoted click reaction to site-specifically immobilize the proteins on surfaces, and it was demonstrated that the functionalized, immobilized scFvs retained their antigen binding specificity. Taken together, the evolved yeast intein platform provides a robust alternative to bacterial intein expression systems.

  2. An Evolved Mxe GyrA Intein for Enhanced Production of Fusion Proteins

    PubMed Central

    2015-01-01

    Expressing antibodies as fusions to the non-self-cleaving Mxe GyrA intein enables site-specific, carboxy-terminal chemical modification of the antibodies by expressed protein ligation (EPL). Bacterial antibody-intein fusion protein expression platforms typically yield insoluble inclusion bodies that require refolding to obtain active antibody-intein fusion proteins. Previously, we demonstrated that it was possible to employ yeast surface display to express properly folded single-chain antibody (scFv)-intein fusions, therefore permitting the direct small-scale chemical functionalization of scFvs. Here, directed evolution of the Mxe GyrA intein was performed to improve both the display and secretion levels of scFv-intein fusion proteins from yeast. The engineered intein was shown to increase the yeast display levels of eight different scFvs by up to 3-fold. Additionally, scFv- and green fluorescent protein (GFP)-intein fusion proteins can be secreted from yeast, and while fusion of the scFvs to the wild-type intein resulted in low expression levels, the engineered intein increased scFv-intein production levels by up to 30-fold. The secreted scFv- and GFP-intein fusion proteins retained their respective binding and fluorescent activities, and upon intein release, EPL resulted in carboxy-terminal azide functionalization of the target proteins. The azide-functionalized scFvs and GFP were subsequently employed in a copper-free, strain-promoted click reaction to site-specifically immobilize the proteins on surfaces, and it was demonstrated that the functionalized, immobilized scFvs retained their antigen binding specificity. Taken together, the evolved yeast intein platform provides a robust alternative to bacterial intein expression systems. PMID:25384269

  3. 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.

  4. Cross sections calculated for cold fusion reactions for producing superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Smolańczuk, Robert

    2008-08-01

    We propose a handy formula for calculating the formation cross sections for optimal bombarding energies for transactinides (superheavy elements). By means of the proposed formula the cross sections for asymmetric and symmetric cold fusion reactions (one-neutron-out reactions) are calculated. The fusion barrier and its position are calculated by using the folding heavy-ion potential that for spherical reaction partners has the form of a seventh-order polynomial of the radial coordinate with built-in dependence on the thickness of the nuclear surface, as well as on the separation energy of the least bound nucleon. Possibilities of further experimental exploitation of cold fusion in producing the superheavy nuclei are briefly discussed.

  5. Cross sections calculated for cold fusion reactions for producing superheavy nuclei

    SciTech Connect

    Smolanczuk, Robert

    2008-08-15

    We propose a handy formula for calculating the formation cross sections for optimal bombarding energies for transactinides (superheavy elements). By means of the proposed formula the cross sections for asymmetric and symmetric cold fusion reactions (one-neutron-out reactions) are calculated. The fusion barrier and its position are calculated by using the folding heavy-ion potential that for spherical reaction partners has the form of a seventh-order polynomial of the radial coordinate with built-in dependence on the thickness of the nuclear surface, as well as on the separation energy of the least bound nucleon. Possibilities of further experimental exploitation of cold fusion in producing the superheavy nuclei are briefly discussed.

  6. 7Li-induced reaction on natMo: A study of complete versus incomplete fusion

    NASA Astrophysics Data System (ADS)

    Kumar, Deepak; Maiti, Moumita; Lahiri, Susanta

    2017-07-01

    Background: Several investigations on the complete-incomplete fusion (CF-ICF) dynamics of α -cluster well-bound nuclei have been contemplated above the Coulomb barrier (˜4 -7 MeV/nucleon) in recent years. It is therefore expected to observe significant ICF over CF in the reactions induced by a weakly bound α -cluster nucleus at slightly above the barrier. Purpose: Study of the CF-ICF dynamics by measuring the populated residues in the weakly bound 7Li+natMo system at energies slightly above the Coulomb barrier to well above it. Method: In order to investigate CF-ICF in the loosely bound system, 7Li beam was bombarded on the natMo foils, separated by the aluminium (Al) catcher foils alternatively, within ˜3 -6.5 MeV/nucleon. Evaporation residues produced in each foil were identified by the off-line γ -ray spectrometry. Measured cross section data of the residues were compared with the theoretical model calculations based on the equilibrium (EQ) and pre-equilibrium (PEQ) reaction mechanisms. Results: The experimental cross section of Rh 101 m,100 ,99 m,97 ,Ru,9597,Tc 99 m,96 ,95 ,94 ,93 m+g , and 93mMo residues measured at various projectile energies were satisfactorily reproduced by the simplified coupled channel approach in comparison to single barrier penetration model calculation. Significant cross section enhancement in the α -emitting channels was observed compared to EQ and PEQ model calculations throughout observed energy region. The ICF process over CF was analyzed by comparing with EMPIRE. The increment of the incomplete fusion fraction was observed with increasing projectile energies. Conclusions: Theoretical model calculations reveal that the compound reaction mechanism is the major contributor to the production of residues in 7Li+natMo reaction. Theoretical evaluations substantiate the contribution of ICF over the CF in α -emitting channels. EMPIRE estimations shed light

  7. Analysis of the role of neutron transfer in asymmetric fusion reactions at subbarrier energies

    SciTech Connect

    Ogloblin, A. A.; Zhang, H. Q.; Lin, C. J.; Jia, H. M.; Khlebnikov, S. V.; Kuzmin, E. A.; Danilov, A. N.; Demyanova, A. S.; Trzaska, W. H.; Xu, X. X.; Yang, F.; Sargsyan, V. V. Adamian, G. G.; Antonenko, N. V.; Scheid, W.

    2015-12-15

    The excitation functions were measured for the {sup 28}Si + {sup 208}Pb complete-fusion (capture) reaction at deep subbarrier energies. The results were compared with the cross sections predicted within the quantum diffusion approach. The role of neutron transfer in the case of positive Q values in the {sup 28}Si + {sup 124}Sn, {sup 208}Pb; {sup 30}Si + {sup 124}Sn, {sup 208}Pb; {sup 20}Ne + {sup 208}Pb; {sup 40}Ca + {sup 96}Zr; and {sup 134}Te + {sup 40}Ca complete-fusion (capture) reactions is discussed.

  8. Barrier for cold-fusion production of superheavy elements

    SciTech Connect

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

    2005-04-01

    We estimate the fusion-barrier height B{sub fu}{sup (two-body)} for approaching ions in cold-fusion reactions in a model where the projectile deformation and quadrupole zero-point vibrational energy are taken into account. This barrier height is defined as the barrier energy at the target and projectile separation distance where an original oblate deformation of projectile and/or target caused by a repulsive Coulomb force turns into a large prolate deformation caused by the attractive nuclear force as the target and projectile come closer. The instability develops before touching because the attractive short-range nuclear force overcomes the repulsive Coulomb force and the shape-stabilizing effect of shell structure. The shell structure of the doubly magic {sup 208}Pb target is sufficiently strong that its shape remains very close to spherical in all cases studied here. The fusion potential for approaching ions in the two-body channel is calculated in the macroscopic-microscopic model with the quadrupole vibrational zero-point energy obtained in the WKB approximation. We compare our results with data from 10 experimental cold-fusion reactions and with the Bass barriers. Differences and similarities between the Yukawa-plus-exponential model and the Bass model are discussed. We also calculate five-dimensional potential-energy surfaces for the single compound system and show that well-established fission and fusion valleys are both present. For heavy systems, B{sub fu}{sup (two-body)} becomes lower than the fission barrier just beyond the ground state of the compound system. In the vicinity of this transition, the optimum collision energy for formation of evaporation residues can be expected to depend in a delicate fashion on the interplay among B{sub fu}{sup (two-body)}, the fusion valley, the fission barrier of the compound system, and the one- and two-neutron separation energies S{sub 1n} and S{sub 2n}. We discuss these issues in detail and calculate fission

  9. Excitation Functions for Complete Fusion and Transfer Reactions in the Interaction of 4He Nuclei with 197Au

    NASA Astrophysics Data System (ADS)

    Kulko, A. A.; Demekhina, N. A.; Kalpakchieva, R.; Muzychka, Yu. A.; Penionzhkevich, Yu. E.; Rassadov, D. N.; Skobelev, N. K.; Testov, D. A.

    2007-05-01

    Excitation functions have been measured for the fusion reaction 197Au(αxn)201-xnTl with the evaporation of x neutrons (0⩽x⩽3) in the energy range 14-36 MeV. The induced-activation method was used for registration and identification of the reaction products. The experimental cross sections for the (1-3)-neutron evaporation residues are in good agreement with the results known from literature. For the radiation capture reaction 197Au(α,γ)201Tl, the upper limit was obtained essentially lower. The excitation functions for the measured reactions are compared with calculations in the frame of the statistical model, as well as with formerly measured similar data with a 6He beam.

  10. Excitation Functions for Complete Fusion and Transfer Reactions in the Interaction of 4He Nuclei with 197Au

    SciTech Connect

    Kulko, A. A.; Demekhina, N. A.; Kalpakchieva, R.; Muzychka, Yu. A.; Penionzhkevich, Yu. E.; Rassadov, D. N.; Skobelev, N. K.; Testov, D. A.

    2007-05-22

    Excitation functions have been measured for the fusion reaction 197Au({alpha}xn)201-xnTl with the evaporation of x neutrons (0{<=}x{<=}3) in the energy range 14-36 MeV. The induced-activation method was used for registration and identification of the reaction products. The experimental cross sections for the (1-3)-neutron evaporation residues are in good agreement with the results known from literature. For the radiation capture reaction 197Au({alpha},{gamma})201Tl, the upper limit was obtained essentially lower. The excitation functions for the measured reactions are compared with calculations in the frame of the statistical model, as well as with formerly measured similar data with a 6He beam.

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

    NASA Astrophysics Data System (ADS)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

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

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

    PubMed

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

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

  13. Fusion reactions and experimental approaches to the synthesis of superheavy nuclei

    SciTech Connect

    Yeremin, A. V.; Utyonkov, V. K.; Oganessian, Yu. Ts.

    1998-02-15

    The question whether the asymmetric actinide based heavy ion reactions could be used for the synthesis of heavy (Z{>=}106) nuclides is essential from the point of view of the study of limitation on fusion, it is also important in such reactions new nuclides close to the magic number N=162 can be produced. Thus as the problem of a hindrance to fusion still remains unsolved the high excitation energy of the compound nucleus looks to be an obvious obstacle to using these reactions. Using the gas-filled recoil separator and electrostatic recoil separator VAS-SILISSA installed at the beam lines of the U-400 heavy ion cyclotron of the FLNR JINR we investigated the fusion reactions leading to 102, 103, 104, 105 and heaviest isotopes of the 106, 108 and 110 elements. The analysis of the measured cross-sections did not reveal any evidence of a hindrance to fusion at the ion bombarding energy close to the Coulomb barrier. {sup 48}Ca+{sup 232}Th{yields}{sup 280}110*, {sup 48}Ca+{sup 238}U{yields}{sup 286}112*, {sup 48}Ca+{sup 244}Pu{yields}{sup 292}114* appear to be the best reactions from the point of view of their cross-sections.

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

    SciTech Connect

    Harca, I. M.; Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Hanappe, F.; Piot, J.; Schmitt, C.; Vardaci, E.

    2015-02-24

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

  15. Inertial confinement fusion reaction chamber and power conversion system study

    SciTech Connect

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  16. Dynamical Dipole mode in heavy-ion fusion reactions in the 192Pb mass region

    NASA Astrophysics Data System (ADS)

    Parascandolo, C.; Pierroutsakou, D.; Alba, R.; Del Zoppo, A.; Maiolino, C.; Santonocito, D.; Agodi, C.; Baran, V.; Boiano, A.; Colonna, M.; Coniglione, R.; De Filippo, E.; Di Toro, M.; Emanuele, U.; Farinon, F.; Guglielmetti, A.; La Commara, M.; Martin, B.; Mazzocchi, C.; Mazzocco, M.; Rizzo, C.; Romoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Torresi, D.; Trifiró, A.; Trimarchi, M.

    2015-04-01

    The dynamical dipole mode was investigated in the mass region of the 192Pb compound nucleus, by using the 40Ca + 152Sm and 48Ca + 144Sm reactions at Elab=11 and 10.1 MeV/nucleon, respectively. Both fusion-evaporation and fission events were studied simultaneously for the first time. Our results for evaporation and fission events (preliminary) show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously.

  17. Charged fusion product loss measurements using nuclear activation

    SciTech Connect

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

    2010-10-15

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

  18. Nuclear fusion reaction rates for strongly coupled ionic mixtures

    SciTech Connect

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

    2009-07-15

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

  19. Influence of projectile neutron number on cross section in cold fusion reactions

    SciTech Connect

    Dragojevic, Irena; Dragojevic, I.; Gregorich, K.E.; Dullmann, Ch.E.; Folden III, C.M.; Garcia, M.A.; Gates, J.M.; Nelson, S.L.; Sudowe, R.; Nitsche, H.

    2007-09-01

    Elements 107-112 [1,2] have been discovered in reactions between {sup 208}Pb or {sup 209}Bi targets and projectiles ranging from {sup 54}Cr through {sup 70}Zn. In such reactions, the compound nucleus can be formed at excitation energies as low as {approx}12 MeV, thus this type of reaction has been referred to as 'cold fusion'. The study of cold fusion reactions is an indispensable approach to gaining a better understanding of heavy element formation and decay. A theoretical model that successfully predicts not only the magnitudes of cold fusion cross sections, but also the shapes of excitation functions and the cross section ratios between various reaction pairs was recently developed by Swiatecki, Siwek-Wilczynska, and Wilczynski [3,4]. This theoretical model, also referred to as Fusion by Diffusion, has been the guide in all of our cold fusion studies. One particularly interesting aspect of this model is the large predicted difference in cross sections between projectiles differing by two neutrons. The projectile pair where this difference is predicted to be largest is {sup 48}Ti and {sup 50}Ti. To test and extend this model, {sup 208}Pb({sup 48}Ti,n){sup 255}Rf and {sup 208}Pb({sup 50}Ti,n){sup 257}Rf excitation functions were recently measured at the Lawrence Berkeley National Laboratory's (LBNL) 88-Inch Cyclotron utilizing the Berkeley Gas-filled Separator (BGS). The {sup 50}Ti reaction was carried out with thin lead targets ({approx}100 {micro}g/cm{sup 2}), and the {sup 48}Ti reaction with both thin and thick targets ({approx}470 {micro}g/cm{sup 2}). In addition to this reaction pair, reactions with projectile pairs {sup 52}Cr and {sup 54}Cr [5], {sup 56}Fe and {sup 58}Fe [6], and {sup 62}Ni [7] and {sup 64}Ni [8] will be discussed and compared to the Fusion by Diffusion predictions. The model predictions show a very good agreement with the data.

  20. Antibody-independent targeted quantification of TMPRSS2-ERG fusion protein products in prostate cancer.

    PubMed

    He, Jintang; Sun, Xuefei; Shi, Tujin; Schepmoes, Athena A; Fillmore, Thomas L; Petyuk, Vladislav A; Xie, Fang; Zhao, Rui; Gritsenko, Marina A; Yang, Feng; Kitabayashi, Naoki; Chae, Sung-Suk; Rubin, Mark A; Siddiqui, Javed; Wei, John T; Chinnaiyan, Arul M; Qian, Wei-Jun; Smith, Richard D; Kagan, Jacob; Srivastava, Sudhir; Rodland, Karin D; Liu, Tao; Camp, David G

    2014-10-01

    Fusions between the transmembrane protease serine 2 (TMPRSS2) and ETS related gene (ERG) represent one of the most specific biomarkers that define a distinct molecular subtype of prostate cancer. Studies of TMPRSS2-ERG gene fusions have seldom been performed at the protein level, primarily due to the lack of high-quality antibodies suitable for quantitative studies. Herein, we applied a recently developed PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM (selected reaction monitoring) strategy for quantifying ERG protein in prostate cancer cell lines and tumors. The highly sensitive PRISM-SRM assays provided confident detection of 6 unique ERG peptides in both TMPRSS2-ERG positive cell lines and tissues, but not in cell lines or tissues lacking the TMPRSS2-ERG rearrangement, clearly indicating that ERG protein expression is significantly increased in the presence of the TMPRSS2-ERG gene fusion. Significantly, our results provide evidence that two distinct ERG protein isoforms are simultaneously expressed in TMPRSS2-ERG positive samples as evidenced by the concomitant detection of two mutually exclusive peptides in two patient tumors and in the VCaP prostate cancer cell line. Three peptides, shared across almost all fusion protein products, were determined to be the most abundant peptides, providing "signature" peptides for detection of ERG over-expression resulting from TMPRSS2-ERG gene fusion. The PRISM-SRM assays provide valuable tools for studying TMPRSS2-ERG gene fusion protein products in prostate cancer. Copyright © 2014. Published by Elsevier B.V.

  1. Nattoh model for cold fusion

    SciTech Connect

    Matsumoto, T. . Dept. of Nuclear Engineering)

    1989-12-01

    A hypothetical model, the Nattoh model, is proposed to answer the questions that result from cold fusion experiments. This model proposes the formation of a small cluster of deuterons and examines the feasibility of many-body fusion reactions. The gamma-ray spectrum, heat production, neutron emissions, and fusion products are discussed.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

    Montagnoli, Giovanna; Stefanini, Alberto M.

    2017-08-01

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

  4. Fusion of artificial membranes with mammalian spermatozoa. Specific involvement of the equatorial segment after acrosome reaction.

    PubMed

    Arts, E G; Kuiken, J; Jager, S; Hoekstra, D

    1993-11-01

    The fusogenic properties of bovine and human spermatozoa membranes were investigated, using phospholipid bilayers (liposomes) as target membranes. Fusion was monitored by following lipid mixing, as revealed by an assay based on resonance-energy transfer. In addition, fusion was visualized by fluorescence microscopy, using fluorescent lipid vesicles. Cryopreserved bovine sperm fused with liposomes before induction of the acrosome reaction, fluorescence being located in essentially all spermatozoa membrane domains. Fresh bovine and human spermatozoa fused with liposomes only after the induction of the acrosome reaction, as triggered by calcium ionophore A23187 or zonae pellucidae (proteins), while the fluorescence distribution was mainly restricted to the equatorial segment (ES). However, with spermatozoa that had undergone a freeze/thawing cycle, domains other than ES also became labeled. Hence, the redistribution of the lipid probes over the entire membrane occurring during lipid mixing with cryopreserved bovine sperm is probably related to membrane perturbations caused by long-term cryopreservation. Fusion with liposomes was governed by spermatozoa factors and required the presence of acidic phospholipids like cardiolipin and phosphatidylserine in the liposomal bilayer. Incorporation of the zwitterionic lipid phosphatidylcholine in the vesicles inhibited the fusion reaction. Fusion was pH dependent. The results indicate that the ES is the primary domain of spermatozoa membranes that harbours the fusogenic capacity of sperm. Liposomes appear a valuable tool in further characterizing the properties of this domain, which has been claimed [Yanagimachi, R. (1988) in The physiology of reproduction (Knobil, E. & Neill, J., eds) pp. 135-185, Raven Press, New York] to represent the putative, initial fusion site for the oocyte.

  5. Proliferation Risks of Magneetic Fusion Energy: Clandestine Production, Covert Production and Breakout

    SciTech Connect

    A. Glaser and R.J. Goldston

    2012-03-13

    Nuclear proliferation risks from magnetic fusion energy associated with access to weapon-usable materials can be divided into three main categories: (1) clandestine production of weapon-usable material in an undeclared facility, (2) covert production of such material inn a declared facility, and (3) use of a declared facility in a breakout scenario, in which a state begins production of fissile material without concealing the effort. In this paper we address each of these categories of risks from fusion. For each case, we find that the proliferation risk from fusion systems can be much lower than the equivalent risk from fission systems, if the fusion system is designed to accommodate appropriate safeguards.

  6. SU-D-304-07: Application of Proton Boron Fusion Reaction to Radiation Therapy

    SciTech Connect

    Jung, J; Yoon, D; Shin, H; Kim, M; Suh, T

    2015-06-15

    Purpose: we present the introduction of a therapy method using the proton boron fusion reaction. The purpose of this study is to verify the theoretical validity of proton boron fusion therapy using Monte Carlo simulations. Methods: After boron is accumulated in the tumor region, the emitted from outside the body proton can react with the boron in the tumor region. An increase of the proton’s maximum dose level is caused by the boron and only the tumor cell is damaged more critically. In addition, a prompt gamma ray is emitted from the proton boron reaction point. Here we show that the effectiveness of the proton boron fusion therapy (PBFT) was verified using Monte Carlo simulations. Results: We found that a dramatic increase by more than half of the proton’s maximum dose level was induced by the boron in the tumor region. This increase occurred only when the proton’s maximum dose point was located within the boron uptake region (BUR). In addition, the 719 keV prompt gamma ray peak produced by the proton boron fusion reaction was positively detected. Conclusion: This therapy method features the advantages such as the application of Bragg-peak to the therapy, the accurate targeting of tumor, improved therapy effects, and the monitoring of the therapy region during treatment.

  7. Energy distribution among reaction products. IV.

    NASA Technical Reports Server (NTRS)

    Maylotte, D. H.; Polanyi, J. C.; Woodall, K. B.

    1972-01-01

    Use of an infrared chemiluminescence technique, called 'Method II,' or the 'method of arrested relaxation' to measure the distribution of energy among products of the Cl + HI and Cl + DI reactions. Preliminary results are also given for the Br + HI and Cl + HBr reactions. Instead of measuring vibrational relaxation, Method II attempts to arrest vibrational and rotational relaxation by the rapid removal of excited products at a cold surface.

  8. Reaction products of ozone: a review.

    PubMed Central

    Glaze, W H

    1986-01-01

    The reaction products of ozone that form during the oxidation of compounds found in aqueous media are reviewed. Reaction products of ozone are well documented only for a limited number of substrates, and mechanistic information is quite rare. Decomposition of ozone during its reactions, sometimes induced by matrix impurities or by the by-products of the reactions, will generate highly reactive hydroxyl radicals. Thus, even reactions occurring at pH less than 7 may have radical character. More complete destruction of organic substrates may be enhanced by using catalysts, such as ultraviolet radiation or hydrogen peroxide, to accelerate radical formation. However, complete mineralization is generally not practical economically, so partially oxidized by-products can be expected under typical treatment conditions. Ozone by-products tend to be oxygenated compounds that are usually, but not always, more biodegradable and less toxic than xenobiotic precursors. Of particular interest are hydroperoxide by-products, which may have escaped detection because of their lability, and unsaturated aldehydes. Inorganic by-products tend to be in high oxidation states, which in some cases (e.g., some metallic elements) may lead to enhanced removal by flocculation and sedimentation. In other cases oxidation may lead to formation of reactive species such as hypobromous acid from bromide ion or permanganate from manganous ion. In general, more research is required before a valid assessment of the risks of ozone by-products can be made. PMID:3545802

  9. Synthesis of transactinide nuclei in cold fusion reactions using radioactive beams

    NASA Astrophysics Data System (ADS)

    Smolańczuk, Robert

    2010-06-01

    Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out reactions) using radioactive beams are evaluated. Because in most of the cases intensities of radioactive beams are significantly less than those of the stable beams, reactions with the greatest radioactive-beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland [Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.76.014612 76, 014612 (2007)], who investigated the same nuclei.

  10. Study of the mechanism of muon-catalyzed t + t fusion reaction

    SciTech Connect

    Bogdanova, L. N.; Demin, D. L.; Filchenkov, V. V.

    2015-01-15

    The mechanism for the muon catalyzed fusion reaction t + t → {sup 4}He + 2n + 11.33 MeV is investigated. The model of the cascade reaction with {sup 5}He as an intermediate state is considered, both the ground and the first exited states being taken into account. The neutron energy spectrum measured in the recent experiment is compared with the Monte-Carlo-simulated one. Varying reaction parameters, we obtain optimum values for the relative weights of the {sup 5}He ground and excited states and for the excitation energy and width of the excited state.

  11. Hyperon production from neutrino-nucleon reaction

    SciTech Connect

    Wu, Jia -Jun; Zou, Bing -Song

    2015-04-10

    The neutrino induced hyperon production processes ν¯e/μ + p → e++ + π + Λ/Σ may provide a unique clean place for studying low energy πΛ/Σ interaction and hyperon resonances below KN threshold. The production rates for some neutrino induced hyperon production processes are estimated with theoretical models. Lastly, suggestions are made for the study of hyperon production from neutrino–nucleon reaction at present and future neutrino facilities.

  12. Hyperon production from neutrino-nucleon reaction

    DOE PAGES

    Wu, Jia -Jun; Zou, Bing -Song

    2015-04-10

    The neutrino induced hyperon production processes ν¯e/μ + p → e+/μ+ + π + Λ/Σ may provide a unique clean place for studying low energy πΛ/Σ interaction and hyperon resonances below KN threshold. The production rates for some neutrino induced hyperon production processes are estimated with theoretical models. Lastly, suggestions are made for the study of hyperon production from neutrino–nucleon reaction at present and future neutrino facilities.

  13. Systematics of calculated cold-fusion barriers for reactions leading to compound systems from Z=104 to Z=126

    SciTech Connect

    Moeller, P.; Armbruster, P.; Hofmann, S.; Muenzenberg, G.

    1998-12-21

    We have previously shown that just as the decay properties of nuclei in the heavy region depend strongly on shell structure, shell structure also dramatically affects the fusion entrance channel. The six most recently discovered new elements were all formed in cold-fusion reactions. We discuss here the effect of the doubly-magic structure of the target in cold-fusion reactions on the fusion barrier and present a systematic study of cold-fusion heavy-ion reaction barriers for elements from Rf to Z=126. We find that the systematics of the optimum reaction energy may change near Z=112, because here the highest point on the interaction barrier shifts in location from near the touching distance at r/R{sub 0}{approx_equal}1.5 to r/R{sub 0}{approx_equal}1.0, which is a shape configuration just slightly more deformed than the ground state.

  14. Systematics of calculated cold-fusion barriers for reactions leading to compound systems from Z=104 to Z=126

    SciTech Connect

    Moller, P.; Hofmann, S.; Munzenberg, G.

    1998-12-01

    We have previously shown that just as the decay properties of nuclei in the heavy region depend strongly on shell structure, shell structure also dramatically affects the fusion entrance channel. The six most recently discovered new elements were all formed in cold-fusion reactions. We discuss here the effect of the doubly-magic structure of the target in cold-fusion reactions on the fusion barrier and present a systematic study of cold-fusion heavy-ion reaction barriers for elements from Rf to Z=126. We find that the systematics of the optimum reaction energy may change near Z=112, because here the highest point on the interaction barrier shifts in location from near the touching distance at r/R{sub 0}{approx}1.5 to r/R{sub 0}{approx}1.0, which is a shape configuration just slightly more deformed than the ground state. {copyright} {ital 1998 American Institute of Physics.}

  15. Universal damping mechanism of quantum vibrations in deep sub-barrier fusion reactions

    NASA Astrophysics Data System (ADS)

    Ichikawa, Takatoshi; Matsuyanagi, Kenichi

    2015-08-01

    We demonstrate the damping of quantum octupole vibrations near the touching point when two colliding nuclei approach each other in the mass-asymmetric 16 O + 208 Pb system, for which the strong fusion hindrance was clearly observed. We, for the first time, apply the random-phase approximation method to the heavy-mass asymmetric dinuclear system to calculate the transition strength B (E 3 ) as a function of the center-of-mass distance. The obtained B (E 3 ) strengths are substantially damped near the touching point, because the single-particle wave functions of the two nuclei strongly mix with each other and a neck is formed. The energy-weighted sums of B (E 3 ) are also strongly correlated with the damping factor, which is phenomenologically introduced in the standard coupled-channel calculations to reproduce the fusion hindrance. This strongly indicates that the damping of the quantum vibrations universally occurs in the deep sub-barrier fusion reactions.

  16. Deep Sub-Barrier Fusion Enhancement in the {sup 6}He+{sup 206}Pb Reaction

    SciTech Connect

    Penionzhkevich, Yu.E.; Zagrebaev, V.I.; Lukyanov, S.M.; Kalpakchieva, R.

    2006-04-28

    The fusion of {sup 6}He with {sup 206}Pb has been studied at energies close to and below the Coulomb barrier. The experiment was carried out at the Dubna Radioactive Ion Beams complex of FLNR, JINR. The {sup 6}He beam intensity was about 5x10{sup 6} pps, the maximum energy being 60.3{+-}0.4 MeV. The yield of the {sup 210}Po isotope, produced in the 2n-evaporation channel, demonstrates an extremely large enhancement of the sub-barrier fusion cross section as compared with the {sup 4}He+{sup 208}Pb reaction. This enhancement is most likely due to the mechanism of 'sequential fusion' with an intermediate neutron transfer from {sup 6}He to the Pb nucleus with positive Q values.

  17. Analysis of the radial potential structure and neutron production rate in the spherical inertial electrostatic confinement fusion devices

    NASA Astrophysics Data System (ADS)

    Ramzanpour, M. A.; Pahlavani, M. R.

    2017-01-01

    The radial dependent potential and neutron production rate in spherical inertial electrostatic confinement fusion (IECF) devices is investigated. The electrostatic potential is determined by solving the Poisson equation for various deuteron and electron distribution functions. The fusion reaction rates are determined using energy distribution function. Also, dependence of potential structure and neutron production rate on some important parameters as the ion and electron convergence, working pressure, kinetic energy of the secondary electrons emitted from the cathode and the fraction of secondary electrons drawn inside the cathode are studied. Total produced neutrons as a function of input power at different working conditions are also obtained.

  18. Spin polarization effects in the /sup 3/H(d,n)/sup 4/He fusion reaction

    SciTech Connect

    Conzett, H.E.; Rioux, C.

    1985-06-01

    A recent investigation has shown that the /sup 3/H(d,n)/sup 4/He fusion reaction rate could be enhanced by a factor of 3/2 if the fusion plasma consisted of both polarized deuterons and tritons, forming exclusively the channel-spin S = 3/2, J = 3/2/sup +/ state. This result follows simply from the statistical weights of the quartet S = 3/2 and doublet S = 1/2 initial states, with the assumption of the single J = 3/2/sup +/ reaction amplitude. Since, with a small but nonzero J = 1/2/sup +/ amplitude, the maximum enhancement of the reaction occurs at the peak of the J = 3/2/sup +/ resonance, corresponding to a deuteron lab energy of 107 keV, it is of obvious interest to know what the enhancement would be at the lower energies that are typical of fusion plasmas. We are able to address this question by extending earlier calculations which gave the values of all of the spin-polarization observables at this J = 3/2/sup +/ resonance in both the /sup 3/H(d,n)/sup 4/He and the /sup 3/He(d,p)/sup 4/He reactions.

  19. Heterologous production of peptides in plants: fusion proteins and beyond.

    PubMed

    Viana, Juliane Flávia Cançado; Dias, Simoni Campos; Franco, Octávio Luiz; Lacorte, Cristiano

    2013-11-01

    Recombinant DNA technology has allowed the ectopic production of proteins and peptides of different organisms leading to biopharmaceutical production in large cultures of bacterial, yeasts and mammalian cells. Otherwise, the expression of recombinant proteins and peptides in plants is an attractive alternative presenting several advantages over the commonly used expression systems including reduced production costs, easy scale-up and reduced risks of pathogen contamination. Different types of proteins and peptides have been expressed in plants, including antibodies, antigens, and proteins and peptides of medical, veterinary and industrial applications. However, apart from providing a proof of concept, the use of plants as platforms for heterologous protein and peptide production still depends on key steps towards optimization including the enhancement of expression levels, manipulation of post-transcriptional modifications and improvements in purification methods. In this review, strategies to increase heterologous protein and peptide stability and accumulation are discussed, focusing on the expression of peptides through the use of gene fusions.

  20. Contribution of activation products to fusion accident risk. I - A preliminary investigation

    NASA Astrophysics Data System (ADS)

    Holdren, J. P.

    1981-01-01

    The health hazards of activation products from fusion-reactor accidents are dealt with in a study on an early conceptual tokamak reactor, using a simple consequence model based on that of the Nuclear Regulatory Commission's Reactor Safety Study (the Rasmussen Report) in order to determine conceivable radiation doses near the plant boundary. Though tritium releases appear to result in fewer casualties than those predicted for the most severe accidents in fission reactors of similar electrical-generating capacity, the boundary doses of stainless-steel and molybdenum structures subject to massive lithium fires are comparable to the doses similarly calculated for 'worst case' light water reactor accidents. Calculations and tables are given for major activation products, their stored energy and their boundary doses in severe fusion and fission accidents. Remedies are suggested for greatly reducing the potential for activation product release from fusion reactors, such as the use of low activation materials, the reduction of stored energy by putting lithium in relatively non-reactive form and the use of deuterium-deuterium instead of D-T reactions.

  1. Suppression of the chain nuclear fusion reaction based on the p+{sup 11}B reaction because of the deceleration of alpha particles

    SciTech Connect

    Shmatov, M. L.

    2016-09-15

    It is shown that a rapid deceleration of alpha particles in matter of electron temperature up to 100 keV leads a strong suppression of the chain nuclear fusion reaction on the basis of the p+{sup 11}B reaction with the reproduction of fast protons in the α+{sup 11}B and n+{sup 10}B reactions. The statement that the chain nuclear fusion reaction based on the p+{sup 11}B reaction with an acceleration of {sup 11}B nuclei because of elastic alpha-particle scattering manifests itself in experiments at the PALS (Prague Asterix Laser System) facility is analyzed.

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  3. Threshold region for Higgs boson production in gluon fusion.

    PubMed

    Bonvini, Marco; Forte, Stefano; Ridolfi, Giovanni

    2012-09-07

    We provide a quantitative determination of the effective partonic kinematics for Higgs boson production in gluon fusion in terms of the collider energy at the LHC. We use the result to assess, as a function of the Higgs boson mass, whether the large m(t) approximation is adequate and Sudakov resummation advantageous. We argue that our results hold to all perturbative orders. Based on our results, we conclude that the full inclusion of finite top mass corrections is likely to be important for accurate phenomenology for a light Higgs boson with m(H)~125 GeV at the LHC with √s=14 TeV.

  4. Effect of charge polarization on the Coulomb barrier for cold-fusion reactions

    SciTech Connect

    Ichikawa, Takatoshi; Iwamoto, Akira

    2005-06-01

    We estimate the decrease of the Coulomb-barrier height between colliding partners due to charge polarizations in the entrance channel for cold-fusion reactions. The resulting charge displacements between protons and neutrons are the sum of the surface- and volume-charge components. We show the difference between the charge polarization of light and heavy nuclei and the decrease of the Coulomb barrier height for synthesizing superheavy elements.

  5. A reassessment of surface friction model for maximum cold fusion reactions in superheavy mass region

    SciTech Connect

    Fukushima, A.; Wada, T.; Ohta, M.; Nasirov, A.; Aritomo, Y.

    2007-02-26

    We have made a study on the capture process of 40,48Ca+ 208Pb systems with a dynamical approach based on the surface friction model. The deformation of the nuclei due to the mutual excitation is taken into account. We have calculated the capture cross sections for several values of the friction coefficients. It was shown that, in the cold fusion reactions, the friction parameters of the surface friction model needs to be reexamined.

  6. Results of an attempt to measure increased rates of the reaction D-2 + D-2 yields He-3 + n in a nonelectrochemical cold fusion experiment

    NASA Technical Reports Server (NTRS)

    Fralick, Gustave C.; Decker, Arthur J.; Blue, James W.

    1989-01-01

    An experiment was performed to look for evidence of deuterium fusion in palladium. The experiment, which involved introducing deuterium into the palladium filter of a hydrogen purifier, was designed to detect neutrons produced in the reaction D-2 + D-2 yields He-3 + n as well as heat production. The neutron counts for deuterium did not differ significantly from background or from the counts for a hydrogen control. Heat production was detected when deuterium, but not hydrogen, was pumped from the purifier.

  7. Heavy-ion inertial fusion: influence of target gain on accelerator parameters for vacuum-propagation regimes in reaction chambers

    SciTech Connect

    Mark, J.W.K.; Bangerter, R.O.; Barletta, W.A.; Fawley, W.M.; Judd, D.L.

    1982-03-04

    Target physics imposes requirements on the design of inertial fusion drivers. The influence of beam propagation in near vacuum fusion reaction chambers is evaluated for the relation between target gain and the phase-space requirements of heavy-ion accelerators. Initial results suggest that neutralization of the ion beam has a much greater positive effect than the deleterious one of beam stripping provided that the fusion chamber pressure is < 10/sup -3/ torr (of Li vapor or equivalent).

  8. Parameterization of fusion barriers for light-projectiles-induced reactions using the proximity approach

    NASA Astrophysics Data System (ADS)

    Gharaei, R.; Sheibani, J.

    2016-05-01

    In this article we propose a pocket formula for fusion barriers calculated by three versions of the proximity formalism, namely AW 95, Bass 80 and Prox. 2010 potentials, for fusion reactions involving the collisions of the proton and helium projectiles with different targets in mass ranges 51≤ AT ≤ 130 and 40≤ AT ≤ 233 , respectively. For the first type of the colliding systems, it is shown that the proposed pocket formulas are able to predict the actual values of RB and VB within accuracies of ±0.4% and ±0.45% , respectively. Moreover, for the second type of the selected reactions, these accuracies are obtained ±0.24% and ±0.36% , respectively. In this study, the ability of the present pocket formulas is also demonstrated to predict the exact values of the fusion cross sections for our selected mass ranges. A comparison with the results of the previous pocket formulas reveals that our parameterized forms are more successful to reproduce the empirical data of the barrier height and position in the proton- and helium-induced reactions.

  9. 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.

  10. Dynamical Dipole Mode in Fusion Heavy-Ion Reactions in the Mass Region of a = 192

    NASA Astrophysics Data System (ADS)

    Parascandolo, C.; Pierroutsakou, D.; Agodi, C.; Alba, R.; Baran, V.; Boiano, A.; Colonna, M.; Coniglione, R.; de Filippo, E.; Del Zoppo, A.; di Toro, M.; Emanuele, U.; Farinon, F.; Guglielmetti, A.; La Commara, M.; Maiolino, C.; Martin, B.; Mazzocco, M.; Mazzocchi, C.; Rizzo, C.; Romoli, M.; Santonocito, D.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Torresi, D.; Trifirò, A.; Trimarchi, M.

    2013-06-01

    The dynamical dipole mode was investigated in the mass region of the 192Pb compound nucleus, by using the 40Ca + 152Sm and 48Ca +144Sm reactions at Elab = 11 and 10.1 MeV/nucleon, respectively. The -ray energy spectra at various polar angles were obtained for fusion-evaporation and fission events by detecting the high energy -rays with the MEDEA experimental apparatus in coincidence with evaporation residues and fission fragments. Our results show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously. However, its yield is lower than that expected within BNV calculations.

  11. Photo-fusion reactions in a new compact device for ELI

    SciTech Connect

    Moustaizis, S. D.; Auvray, P.; Hora, H.; Lalousis, P.; Larour, J.; Mourou, G.

    2012-07-09

    In the last few years significant progress on technological, experimental and numerical studies on fusion process in high density and high temperature plasmas produced by a high intensity laser pulse interaction with clusters in a high external applied magnetic field, enable us to propose a compact photo-fusion magnetic device for high neutron production. For the purpose of the project a pulsed magnetic field driver with values up to 110 Tesla has been developed which allows increasing the trapping time of the high density plasma in the device and improving the neutron yield. Numerical simulations show that the proposed device is capable of producing up to 10{sup 9}-10{sup 10} neutrons per laser shot with an external magnetic field of 150 Tesla. The proposed device can be used for experiments and numerical code validation concerning different conventional and (or) exotic fusion fuels.

  12. Strong screening by lattice confinement and resultant fusion reaction rates in fcc metals

    NASA Astrophysics Data System (ADS)

    Prados-Estévez, F. M.; Subashiev, A. V.; Nee, H. H.

    2017-09-01

    The effects of electronic screening on the cross sections and reactivities for the nuclear reactions between light nuclei in Pd and Ni is studied. We consider the applicability of the theory of thermonuclear burning in stars to the D-D nuclear reaction in metals. The screening model based on the mean field potential of the electron cloud in the metal plasma is used. We discuss the specifics of the screening for the H (D) atoms embedded in vacancies and divacancies. High concentration of hydrogen isotopes segregated to monovacancies and divacancies in face-centered cubic (fcc) metals such as Ni and Pd with densities of ∼ 6 ×1023atom /cm3 , makes the hydrogen cluster a favorable active site for the fusion reaction. Still the observation of a nuclear reaction requires an accumulation of energy in D nuclei of at least several eV, which is far above what can be achieved in the thermal heating experiments.

  13. Astrophysical S factors for fusion reactions involving C, O, Ne, and Mg isotopes

    SciTech Connect

    Beard, M.; Afanasjev, A.V.; Chamon, L.C.; Gasques, L.R.; Wiescher, M.; Yakovlev, D.G.

    2010-09-15

    Using the Sao Paulo potential and the barrier penetration formalism we have calculated the astrophysical factor S(E) for 946 fusion reactions involving stable and neutron-rich isotopes of C, O, Ne, and Mg for center-of-mass energies E varying from 2 to {approx}18-30 MeV (covering the range below and above the Coulomb barrier). We have parameterized the energy dependence, S(E), by an accurate universal 9-parameter analytic expression and present tables of fit parameters for all the reactions. We also discuss the reduced 3-parameter version of our fit which is highly accurate at energies below the Coulomb barrier, and outline the procedure for calculating the reaction rates. The results can be easily converted to thermonuclear or pycnonuclear reaction rates to simulate various nuclear burning phenomena, in particular, stellar burning at high temperatures and nucleosynthesis in high density environments.

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

    SciTech Connect

    Hussein, M. S.

    2008-04-17

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

  15. Measurement of the ^12C+^12C Fusion Reaction with MUSIC

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    The fusion of the ^12C+^12C system is of great interest in nuclear structure and nuclear astrophysics. Above the Coulomb barrier, the excitation function of this system exhibits oscillations, which are not well understood. There is also a significant discrepancy between the experimental fusion cross-section and recent coupled-channel calculations that is not present in other carbon systems. To address these issues, we have re-measured the fusion excitation function for ^12,13C+^12C in the energy range of 10 MeV < Ecm < 20 MeV using a Multi-Sampling Ionization Chamber (MUSIC) detector. The gas of the ionization chamber (CH4) served as both the target material and the counter gas. One of the main advantages of this method is that the excitation function is measured over a large range of energies using only one beam energy. This method has been proven to be successful and it will be used to measure fusion reactions in other light systems. The experimental results will be presented and compared to previous experimental data and theoretical models.

  16. Trotter products and reaction-diffusion equations

    NASA Astrophysics Data System (ADS)

    Popescu, Emil

    2010-01-01

    In this paper, we study a class of generalized diffusion-reaction equations of the form , where A is a pseudodifferential operator which generates a Feller semigroup. Using the Trotter product formula we give a corresponding discrete time integro-difference equation for numerical solutions.

  17. 3D Fokker-Planck modeling of axisymmetric collisional losses of fusion products in TFTR

    SciTech Connect

    Goloborod`ko, V.Ya.; Reznik, S.N.; Yavorskij, V.A.; Zweben, S.J.

    1995-10-01

    Results of a 3D (in constants of motion space) Fokker-Planck simulation of collisional losses of fusion products in axisymmetric DT and DD discharges on TFTR are presented. The distributions of escaped ions over poloidal angle, pitch angle, and their energy spectra are obtained. Axisymmetric collisional losses of fusion products are found to be less than (2--5)%. The distribution of confined fusion products is shown to be strongly anisotropic and nonuniform in the radial coordinate mainly for slowed-down fusion products with small longitudinal energy. Comparison of these results of modeling and experimental data is done.

  18. Cross Section Measurements of 12C+16O Fusion Reaction at Stellar Energies

    NASA Astrophysics Data System (ADS)

    Tan, Wanpeng; Fang, X.; Beard, M.; Gilardy, G.; Jung, H.; Liu, Q.; Lyons, S.; Robertson, D.; Setoodehnia, K.; Seymour, C.; Stech, E.; Vande Kolk, B.; Wiescher, M.; de Souza, R.; Hudan, S.; Singh, V.; Tang, X.; Uberseder, E.

    2016-09-01

    12C+16O is one of the three fusion reactions (12C+12C, 12C+16O, and 16O+16O) that play an important role at the late stage of stellar evolution in massive stars. The previous meassurements of its cross section at low energies rely on the singles measurements of either gamma rays or charged particles. New measurement was conducted for the 12C+16O reaction at Ecm = 3.64 - 4.93 MeV with the detection of both gammas and charged particles using the high intensity St ANA accelerator at the University of Notre Dame. The protons and alphas from the fusion evaporation were measured by a large area silicon strip detector array (SAND) while the gamma rays were detected by one large volume HPGe detector right after the target. Statistical model calculation were employed to interpret the experimental results. This provided a more reliable extrapolation for the 12C+16O fusion cross section, reducing substantially the uncertainty for stellar model simulations. This work was supported by the National Science Foundation through Grant Numbers PHY-1068192 and PHY-1419765 and the Joint Institute for Nuclear Astrophysics under Grant No. PHY-0822648.

  19. Cell-free mitochondrial fusion assay detected by specific protease reaction revealed Ca2+ as regulator of mitofusin-dependent mitochondrial fusion.

    PubMed

    Ishihara, Naotada; Maeda, Maki; Ban, Tadato; Mihara, Katsuyoshi

    2017-04-27

    Mitochondrial dynamic by frequent fusion and fission have important roles in various cellular signaling processes and pathophysiology in vivo. However, the molecular mechanisms that regulate mitochondrial fusion, especially in mammalian cells, are not well understood. Accordingly, we developed a novel biochemical cell-free mitochondrial fusion assay system using isolated human mitochondria. We used a protease and its specific substrate that are essential for yeast autophagy; Atg4 protease is required for maturation and the de-conjugation of the ubiquitin-like modifier Atg8. Atg4-FLAG and Atg8-GFP were separately expressed in the mitochondrial matrix of HeLa cells. Isolated mitochondria were then mixed and packed in the presence of energy regeneration mix. Immunoblotting with an anti-GFP antibody revealed Atg8 processing, suggesting that the double membranes of isolated mitochondria were indeed fused. The mitochondrial fusion reaction required GTP hydrolysis, mitochondrial membrane potential, and intact outer membrane proteins containing two mitofusin isoforms. Using this assay, we searched for stimulators of mitochondrial fusion and found that rabbit reticulocyte lysate and Ca2+ chelator EGTA stimulate mitochondrial fusion. This novel cell-free assay system using isolated human mitochondria is simple, sensitive, and reproducible; thus, it is useful for screening proteins and molecules that modulate mitochondrial fusion. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  20. Experimental Study of p-11B Reaction Related to the Clean Fusion Fuel

    NASA Astrophysics Data System (ADS)

    Lin, Erh-kang; Wang, Chang-wan; Yuan, Jian; Liu, Xiao-dong; Li, Cheng-bo; Sun, Zu-xun; Zhang, Pei-hua; Chen, Jin-xiang; Yang, Qi-xiang; Wang, Jian-yong; Ling-hua, Gong

    1998-11-01

    Whole continuous α spectra of the p-11B three-body sequential decay reaction have been measured by using a charge particle time-of-flight (TOF) spectrometer with the high-resolution passivated implanted planar silicon detector. A characteristic shape of the saddle-type distribution was obtained. The Monte Carlo calculations show that observed α spectra can be interpreted by anisotropy sequential decay process of the intermediate nucleus 8Be (1) for the p-11B reaction. In the measurement, angular distributions were obtained for proton energies at 667 and 1370 keV, respectively. Total cross-sections for the 11B(p,α)8Be(2α) reaction related to the clean fusion fuel were also reported at two bombarding energies.

  1. 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.

  2. Fusion of Polarized Deuterons

    NASA Astrophysics Data System (ADS)

    Hofmann, H. M.; Fick, D.

    1984-06-01

    The nuclear physics aspects of the d-d reactions initiated by low-energy polarized deuterons are discussed. It is shown that the use of polarized deuterons does not suppress the fusion of deuterons with deuterons and hence does not suppress neutron production. Therefore a recently proposed "neutron-free" d-3He fusion reactor is unlikely to work.

  3. Application of proton boron fusion reaction to radiation therapy: A Monte Carlo simulation study

    SciTech Connect

    Yoon, Do-Kun; Jung, Joo-Young; Suh, Tae Suk

    2014-12-01

    Three alpha particles are emitted from the point of reaction between a proton and boron. The alpha particles are effective in inducing the death of a tumor cell. After boron is accumulated in the tumor region, the emitted from outside the body proton can react with the boron in the tumor region. An increase of the proton's maximum dose level is caused by the boron and only the tumor cell is damaged more critically. In addition, a prompt gamma ray is emitted from the proton boron reaction point. Here, we show that the effectiveness of the proton boron fusion therapy was verified using Monte Carlo simulations. We found that a dramatic increase by more than half of the proton's maximum dose level was induced by the boron in the tumor region. This increase occurred only when the proton's maximum dose point was located within the boron uptake region. In addition, the 719 keV prompt gamma ray peak produced by the proton boron fusion reaction was positively detected. This therapy method features the advantages such as the application of Bragg-peak to the therapy, the accurate targeting of tumor, improved therapy effects, and the monitoring of the therapy region during treatment.

  4. Application of proton boron fusion reaction to radiation therapy: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Yoon, Do-Kun; Jung, Joo-Young; Suh, Tae Suk

    2014-12-01

    Three alpha particles are emitted from the point of reaction between a proton and boron. The alpha particles are effective in inducing the death of a tumor cell. After boron is accumulated in the tumor region, the emitted from outside the body proton can react with the boron in the tumor region. An increase of the proton's maximum dose level is caused by the boron and only the tumor cell is damaged more critically. In addition, a prompt gamma ray is emitted from the proton boron reaction point. Here, we show that the effectiveness of the proton boron fusion therapy was verified using Monte Carlo simulations. We found that a dramatic increase by more than half of the proton's maximum dose level was induced by the boron in the tumor region. This increase occurred only when the proton's maximum dose point was located within the boron uptake region. In addition, the 719 keV prompt gamma ray peak produced by the proton boron fusion reaction was positively detected. This therapy method features the advantages such as the application of Bragg-peak to the therapy, the accurate targeting of tumor, improved therapy effects, and the monitoring of the therapy region during treatment.

  5. 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.

  6. 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.

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

    PubMed

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

    2011-03-01

    As shown by the birth of the first cloned dog 'Snuppy', a protocol to produce viable cloned dogs has been reported. In order to evaluate optimum fusion conditions for improving dog cloning efficiency, in vivo matured oocytes were reconstructed with adult somatic cells from a female Pekingese using different fusion conditions. Fusion with needle vs chamber methods, and with low vs high pulse strength was compared by evaluating fusion rate and in vivo development of canine cloned embryos. The fusion rates in the high voltage groups were significantly higher than in the low voltage groups regardless of fusion method (83.5 vs 66.1% for the needle fusion method, 67.4 vs 37.9% for the fusion chamber method). After embryo transfer, one each pregnancy was detected after using the needle fusion method with high and low voltage and in the chamber fusion method with high voltage, whereas no pregnancy was detected using the chamber method with low voltage. However, only the pregnancy from the needle fusion method with high voltage was maintained to term and one healthy puppy was delivered. The results of the present study demonstrated that two DC pulses of 3.8 to 4.0 kV/cm for 15 μsec using the needle fusion method were the most effective method for the production of cloned dogs under the conditions of this experiment. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Thermal-to-fusion neutron convertor and Monte Carlo coupled simulation of deuteron/triton transport and secondary products generation

    NASA Astrophysics Data System (ADS)

    Wang, Guan-bo; Liu, Han-gang; Wang, Kan; Yang, Xin; Feng, Qi-jie

    2012-09-01

    Thermal-to-fusion neutron convertor has being studied in China Academy of Engineering Physics (CAEP). Current Monte Carlo codes, such as MCNP and GEANT, are inadequate when applied in this multi-step reactions problems. A Monte Carlo tool RSMC (Reaction Sequence Monte Carlo) has been developed to simulate such coupled problem, from neutron absorption, to charged particle ionization and secondary neutron generation. "Forced particle production" variance reduction technique has been implemented to improve the calculation speed distinctly by making deuteron/triton induced secondary product plays a major role. Nuclear data is handled from ENDF or TENDL, and stopping power from SRIM, which described better for low energy deuteron/triton interactions. As a validation, accelerator driven mono-energy 14 MeV fusion neutron source is employed, which has been deeply studied and includes deuteron transport and secondary neutron generation. Various parameters, including fusion neutron angle distribution, average neutron energy at different emission directions, differential and integral energy distributions, are calculated with our tool and traditional deterministic method as references. As a result, we present the calculation results of convertor with RSMC, including conversion ratio of 1 mm 6LiD with a typical thermal neutron (Maxwell spectrum) incidence, and fusion neutron spectrum, which will be used for our experiment.

  9. Dynamical Dipole Mode in Heavy-Ion Fusion-Evaporation and Fission Reactions in the {sup 192}Pb Mass Region

    SciTech Connect

    Silvestri, R.; Inglima, G.; La Commara, M.; Martin, B.; Sandoli, M.; Pierroutsakou, D.; Parascandolo, C.; Boiano, A.; Romoli, M.; Agodi, C.; Alba, R.; Colonna, M.; Coniglione, R.; Del Zoppo, A.; Maiolino, C.; Santonocito, D.; Baran, V.; De Filippo, E.; Di Toro, M.; Rizzo, C.

    2011-10-28

    The prompt {gamma}-ray emission related with the dynamical dipole mode decay was investigated in the {sup 192}Pb mass region by means of the {sup 40}Ca+{sup 152}Sm and {sup 48}Ca+{sup 144}Sm fusion-evaporation and fission reactions at E{sub lab} = 11 and 10.1 MeV/nucleon, respectively. The two reactions populate, through entrance channel having different charge asymmetries, the {sup 192}Pb compound nucleus at an excitation energy of 236 MeV with identical spin distribution. Preliminary results of this experiment show that the dynamical dipole mode survives in collisions involving heavier mass reaction partners than those studied previously. As a fast cooling mechanism on the fusion path, the prompt dipole {gamma} radiation could be of interest for the synthesis of super-heavy elements through ''hot'' fusion reactions.

  10. An overview on incomplete fusion reaction dynamics at energy range ∼ 3-8 MeV/A

    SciTech Connect

    Ali, Rahbar; Singh, D.; Ansari, M. Afzal; Kumar, Rakesh; Muralithar, S.; Golda, K. S.; Singh, R. P.; Bhowmik, R. K.; Rashid, M. H.; Guin, R.; Das, S. K.

    2014-08-14

    The information of ICF reaction has been obtained from the measurement of excitation function (EF) of ERs populated in the interaction of {sup 20}Ne and {sup 16}O on {sup 55}Mn, {sup 159}Tb and {sup 156}Gd targets. Sizable enhancement in the measured cross-sections has been observed in α-emitting channels over theoretical predictions, which has been attributed to ICF of the projectile. In order to confirm the findings of the measurements and analysis of EFs, the forward recoil range distributions of ERs populated in {sup 20}Ne+{sup 159}Tb (E ∼165MeV) and {sup 16}O+{sup 156}Gd (E ∼ 72, 82 and 93MeV) systems, have been measured. It has been observed that peaks appearing at different cumulative thicknesses in the stopping medium are related with different degree of linear momentum transfer from projectile to target nucleus by adopting the break-up fusion model consideration. In order to deduce the angular momentum involved in various CF and / or ICF reaction products, spin distribution and side-feeding intensity profiles of radio-nuclides populated via CF and ICF channels in {sup 16}O+{sup 160}Gd system at energy, E ∼ 5.6 MeV/A, have been studied. Spin distribution of ICF products are found to be distinctly different than that observed from CF products.

  11. Comment on ‘On the fusion triple product and fusion power gain of tokamak pilot plants and reactors’, by A. Costley

    NASA Astrophysics Data System (ADS)

    Biel, W.; Lackner, K.; Sauter, O.; Wenninger, R.; Zohm, H.

    2017-03-01

    In this comment, we discuss the arguments raised in two recent papers (Costley 2016 Nucl. Fusion 56 066003, Costley et al 2015 Nucl. Fusion 55 033001) on the claimed size independence of fusion power, triple product and fusion gain in tokamak reactors, and we show that all these three quantities actually do depend on the size of the tokamak, when distinguishing between independent input parameters (design parameters) and output quantities, and when taking into account technological limitations.

  12. Advanced scheme for high-yield laser driven proton-boron fusion reaction

    NASA Astrophysics Data System (ADS)

    Margarone, D.; Picciotto, A.; Velyhan, A.; Krasa, J.; Kucharik, M.; Morrissey, M.; Mangione, A.; Szydlowsky, A.; Malinowska, A.; Bertuccio, G.; Shi, Y.; Crivellari, M.; Ullschmied, J.; Bellutti, P.; Korn, G.

    2015-02-01

    A low contrast nanosecond laser pulse with relatively low intensity (3 × 1016 W cm-2) was used to enhance the yield of induced nuclear reactions in advanced solid targets. In particular the "ultraclean" proton-boron fusion reaction, producing energetic alpha-particles without neutron generation, was chosen. A spatially well-defined layer of boron dopants in a hydrogen-enriched silicon substrate was used as target. The combination of the specific target geometry and the laser pulse temporal shape allowed enhancing the yield of alpha-particles up to 109 per steradian, i.e 100 times higher than previous experimental achievements. Moreover the alpha particle stream presented a clearly peaked angular and energy distribution, which make this secondary source attractive for potential applications. This result can be ascribed to the interaction of the long laser pre-pulse with the target and to the optimal target geometry and composition.

  13. Entrance Channel Dynamics of Hot and Cold Fusion Reactions Leading to Superheavy Elements

    NASA Astrophysics Data System (ADS)

    Umar, Sait; Oberacker, Volker

    2010-11-01

    One of the most fascinating research areas involving low-energy nuclear reactions is the search for superheavy elements. Experimentally, two approaches have been used for the synthesis of these elements, one utilizing closed shell nuclei with lead-based targets (cold-fusion), the other utilizing deformed actinide targets with ^48Ca projectiles (hot-fusion). In this talk we investigate the entrance channel dynamics for the reactions ^70Zn+^208Pb and ^48Ca+^238U using the fully microscopic time-dependent Hartree-Fock (TDHF) theory coupled with a density constraint [1-3]. We calculate excitation energies and capture cross-sections relevant for the study of superheavy formations. We discuss the deformation dependence of the ion-ion potential for the ^48Ca+^238U system and perform an alignment angle averaging for the calculation of the capture cross-section. The results show that this approach can generate results in good agreement with experiment and other theories.[4pt] [1] Umar, Oberacker, PRC 74, 061601(R) (2006).[0pt] [2] Umar, Oberacker, EPJA 39, 243 (2009).[0pt] [3] Umar, Maruhn, Itagaki, and Oberacker, PRL 104, 212503.

  14. Detailed determination of the nuclear fusion radius by a simultaneous optical model calculation of elastic scattering and fusion cross sections in reactions involving weakly bound projectiles

    SciTech Connect

    Camacho, A. Gomez; Aguilera, E. F.; Gomes, P. R. S.; Lubian, J.

    2007-10-15

    Within the optical model for direct reactions, simultaneous calculations of elastic scattering, complete fusion, and total reaction cross sections for energies around the Coulomb barrier are presented for reactions involving the weakly bound projectile {sup 9}Be on {sup 64}Zn. Volume (W{sub F}) and surface (W{sub DR}) Woods-Saxon optical potentials are used such that the former is responsible only for complete fusion reactions while the latter for all direct reactions plus incomplete fusion. Simultaneous fits can be obtained with several sets of potential parameters, but if we impose the condition that the strength of W{sub F} is smaller than the strength of W{sub DR} at the tail region of the potential (this condition is discussed in detail), then values are required for r{sub F} and r{sub DR} of around 1.6 and 1.7-1.9 fm, respectively. These values are much larger than those frequently used in barrier penetration model calculations. Through the energy dependence of the real and imaginary parts of the polarization potentials, we show that the usual threshold anomaly does not show up for this system, but instead there is evidence of the presence of a breakup threshold anomaly.

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

    SciTech Connect

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

    2015-07-15

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

  16. Complete and incomplete fusion dynamics of 6,7Li + 159Tb reactions near the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Gautam, Manjeet Singh; Grover, Neha; Sharma, Manoj K.

    2017-01-01

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

  17. Confinement of fusion reaction products during the fishbone instability

    SciTech Connect

    Heidbrink, W.W.; Hay, R.; Strachan, J.D.

    1984-11-12

    The presence of fishbone events in the PDX tokamak is correlated with a reduction in the burnup of 0.8-MeV /sup 3/He ions. This reduction is probably caused by distortion of the /sup 3/He drift orbitals in the helical magnetic fields associated with the instability, resulting in the loss of about 70% of the confined /sup 3/He ions in a moderately strong fishbone. Such a nonresonant loss of particles with large orbits indicates that fishbone events may influence 3.5-MeV alphas in ignition experiments.

  18. Confinement of fusion reaction products during the fishbone instability

    SciTech Connect

    Heidbrink, W.W.; Hay, R.; Strachan, J.D.

    1984-09-01

    The presence of fishbone events in the PDX tokamak is correlated with a reduction in the burnup of 0.8 MeV /sup 3/He ions. This reduction is probably caused by distortion of the /sup 3/He drift orbits in the helical magnetic fields associated with the instability, resulting in the loss of about 70% of the confined /sup 3/He ions in a moderately strong fishbone. Such a nonresonant loss of particles with large orbits indicates that fishbone events may influence 3.5 MeV alphas in ignition experiments.

  19. Analysis of complete, incomplete and total fusion data of 9Be +169Tm, 187Re, 209Bi reactions

    NASA Astrophysics Data System (ADS)

    Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

    2016-11-01

    We have analyzed the incomplete fusion (ICF), complete fusion (CF) and total fusion (TF) excitation functions for reactions induced by 9Be on 169Tm, 187Re and 209Bi targets at near barrier energies using Wong’s formula in conjunction with the energy dependent Woods-Saxon potential. A phenomenological selection function is proposed to separate out the contribution of ICF and CF cross-sections in TF cross-section. The variation of relative contribution of ICF and CF in TF with respect to incident beam energy is very well reproduced through this approach.

  20. Inertial fusion: an energy-production option for the future

    SciTech Connect

    Hovingh, J.; Pitts, J.H.; Monsler, M.J.; Grow, G.R.

    1982-05-01

    The authors discuss the inertial-confinement approach to fusion energy. After explaining the fundamentals of fusion, they describe the state of the art of fusion experiments, emphasizing the results achieved through the use of neodymium-doped glass lasers at Lawrence Livermore National Laboratory and at other laboratories. They highlight recent experimental results confirming theoretical predictions that short-wavelength lasers have excellent energy absorption on fuel pellets. Compressions of deuterium-tritium fuel of over 100 times liquid density have been measured, only a factor of 10 away from the compression required for a commercial reactor. Finally, it is shown how to exploit the unique characteristics of inertial fusion to design reactor chambers that have a very high power density and a long life, features that the authors believe will eventually lead to fusion power at a competitive cost.

  1. Charge-exchange reaction by Reggeon exchange and W{sup +}W{sup −}-fusion

    SciTech Connect

    Schicker, R.

    2015-04-10

    Charge-exchange reactions at high energies are examined. The existing cross section data on the Reggeon induced reaction pp → n + Δ{sup ++} taken at the ZGS and ISR accelerators are extrapolated to the energies of the RHIC and LHC colliders. The interest in the charge-exchange reaction induced by W{sup ±}-fusion is presented, and the corresponding QCD-background is examined.

  2. Advanced fusion diagnostics

    NASA Astrophysics Data System (ADS)

    Moses, K. G.

    1993-07-01

    Key among various issues of ignited plasmas is understanding the physics of energy transfer between thermal plasma particles and magnetically confined, highly energetic charged ions in a tokamak device. The superthermal particles are products of fusion reactions. The efficiency of energy transfer by collisions, from charged fusion products (e.g., (alpha)-particles) to plasma ions, grossly determines whether or not plasma conditions are self-sustaining without recourse to auxiliary heating. Furthermore, should energy transfer efficiency be poor, and substantial auxiliary heating power is required to maintain reacting conditions within the plasma, economics may preclude commercial viability of fusion reactors. The required charged fusion product information is contained in the energy distribution function of these particles. Knowledge of temporal variations of the superthermal particle energy distribution function could be used by a fusion reactor control system to balance plasma conditions between thermal runaway and a modicum of fusion product energy transfer. Therefore, diagnostics providing data on the dynamical transfer of alpha-particle and other charged fusion product energy to the plasma ions are essential elements for a fusion reactor control system to insure that proper plasma conditions are maintained. The objective of this work is to assess if spectral analysis of RF radiation emitted by charged fusion products confined in a magnetized plasma, called ion cyclotron emission (ICE), can reveal the vital data of the distribution function of the superthermal particles.

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

    SciTech Connect

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

    2003-04-02

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

  4. Study of fusion product effects in field-reversed mirrors

    SciTech Connect

    Driemeyer, D.E.

    1980-01-01

    The effect of fusion products (fps) on Field-Reversed Mirror (FRM) reactor concepts has been evaluated through the development of two new computer models. The first code (MCFRM) treats fps as test particles in a fixed background plasma, which is represented as a fluid. MCFRM includes a Monte Carlo treatment of Coulomb scattering and thus provides an accurate treatment of fp behavior even at lower energies where pitch-angle scattering becomes important. The second code (FRMOD) is a steady-state, globally averaged, two-fluid (ion and electron), point model of the FRM plasma that incorporates fp heating and ash buildup values which are consistent with the MCFRM calculations. These codes have been used extensively in the development of an advanced-fuel FRM reactor design (SAFFIRE). A Catalyzed-D version of the plant is also discussed along with an investigation of the steady-state energy distribution of fps in the FRM. User guides for the two computer codes are also included.

  5. Fusion of pyruvate decarboxylase and alcohol dehydrogenase increases ethanol production in Escherichia coli.

    PubMed

    Lewicka, Aleksandra J; Lyczakowski, Jan J; Blackhurst, Gavin; Pashkuleva, Christiana; Rothschild-Mancinelli, Kyle; Tautvaišas, Dainius; Thornton, Harry; Villanueva, Hugo; Xiao, Weike; Slikas, Justinas; Horsfall, Louise; Elfick, Alistair; French, Christopher

    2014-12-19

    Ethanol is an important biofuel. Heterologous expression of Zymomonas mobilis pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) increases ethanol production in Escherichia coli. A fusion of PDC and ADH was generated and expressed in E. coli. The fusion enzyme was demonstrated to possess both activities. AdhB activity was significantly lower when fused to PDC than when the two enzymes were expressed separately. However, cells expressing the fusion protein generated ethanol more rapidly and to higher levels than cells coexpressing Pdc and AdhB, suggesting a specific rate enhancement due to the fusion of the two enzymes.

  6. Transport and deposition of activation products in a helium cooled fusion power plant

    SciTech Connect

    Bickford, W.E.

    1980-09-01

    The transport and deposition of neutron activation products in a helium cooled tokamak fusion power plant are investigated. Stainless steel is used as coolant channel material for a helium/steam system. The important gamma emitting nuclides /sup 56/Mn, /sup 54/Mn, /sup 57/Co, /sup 58/Co, /sup 60/Co, /sup 51/Cr, and /sup 99/Mo are considered. The dominant release mechanism identified is direct daughter recoil emission from (n,x) type reactions. Corrosion and evaporation are discussed. The radionuclide inventory released by these mechanisms is predicted to exceed 1 x 10/sup 4/ Ci for a reference reactor design after only several days of operation, and approach 3.5 x 10/sup 4/ Ci in equilibrium. A mass transport model is then used to predict the deposition pattern of this inventory in the reactor cooling system.

  7. Utility of spectral measurements of secondary reaction products

    SciTech Connect

    Heidbrink, W.E.

    1986-02-01

    The spectra of 15 MeV protons and 14 MeV neutrons produced in the burnup of 0.8 MeV THe ions and 1 MeV tritons through the d(THe,p) and d(t,n) fusion reactions contain information on the velocity distributions of the energetic THe ions and tritons. 11 refs., 2 figs.

  8. Measurement of long-lived isotopes and helium production in fusion materials

    SciTech Connect

    Greenwood, L.R.

    1989-01-01

    Results are summarized for measurements of the production rates for long-lived radioisotopes and helium in fusion reactor materials. Measurements have been performed at T(d,n) generators, near 14 MeV; at broad-spectrum Be(d,n) accelerator-based neutron fields; and in various fission reactors. These activation data are used to predict the production of these isotopes in fusion reactor materials for the simulation of fusion materials damage in fission reactor irradiations and as a stable product dosimeter. Nuclear data needs and future plans are discussed. 20 refs., 5 figs., 4 tabs.

  9. Linear induction accelerators for fusion and neutron production

    SciTech Connect

    Barletta, W.A. |

    1993-08-01

    Linear induction accelerators (LIA) with pulsed power drives can produce high energy, intense beams or electrons, protons, or heavy ions with megawatts of average power. The continuing development of highly reliable LIA components permits the use such accelerators as cost-effective beam sources to drive fusion pellets with heavy ions, to produce intense neutron fluxes using proton beams, and to generate with electrons microwave power to drive magnetic fusion reactors and high gradient, rf-linacs.

  10. An investigation of alpha-like particles in the DIII-D tokamak using fusion-product diagnostics

    SciTech Connect

    Duong, H.H.

    1993-01-01

    Two important issues associated with alpha physics, the single-particle behavior and the effect of collective fast-ion-driven instabilities on fast-ion confinement, have been studied in the DIII-D tokamak using fusion product diagnostics. The single-particle behavior of alpha-like tritons and [sup 3]He ions produced in deuterium-deuterium fusion reactions is studied using the d(t,n)[alpha] and d([sup 3]he,p)[alpha] fusion reactions. Fusion-produced MeV ions exhibit classical behavior in high field (B[sub T] [ge] 1.0 T) DIII-D discharges, including the new class of [open quotes]very high[close quotes] confinement plasmas. However, discharges with strong sawtooth, fishbone, or TAE activity exhibit anomalous fusion product losses. For the high field discharges without strong MHD activity, the data imply an effective diffusion coefficient smaller than [approximately]0.1 m[sup 2]/s, but in the presence of strong MHD activity, the effective diffusion of the MeV ions exceeds 1.0 m[sup 2]/s. Collective alpha particle processes are simulated by means of neutral beam injected energetic ion minorities. Toroidicity-induced Alfven Eigenmodes (TAE) are observed in DIII-D when energetic beam ions ([approximately]75 keV) are used to destabilize the mode. Measurements of the neutron emission indicate that up to 70% of the injected power is lost during strong TAE activity. Measurements of the poloidal distribution of fast-ion losses suggest that the losses are greatest near the vessel midplane. Fast-ion losses in discharges with combined fishbones and TAE bursts are 1.5 to 2 times greater than losses in fishbone discharges without TAE activity. The scaling of fast ion losses with MHD mode amplitude exhibits no threshold in the mode amplitude, suggesting that mode-particle pumping is the dominant loss mechanism.

  11. Calculations of long-lived isomer production in neutron reactions

    SciTech Connect

    Chadwick, M.B.; Young, P.G.

    1991-01-01

    We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. 16 refs., 9 figs., 6 tabs.

  12. Clustering effects in fusion evaporation reactions with light even-even N=Z nuclei

    NASA Astrophysics Data System (ADS)

    Morelli, L.; D'Agostino, M.; Bruno, M.; Frosin, C.; Gulminelli, F.; Gramegna, F.; Cinausero, M.; Marchi, T.; Fabris, D.; Degerlier, M.; Casini, G.; Barlini, S.; Bini, M.; Pasquali, G.; Olmi, A.; Piantelli, S.; Valdré, S.; Pastore, G.; Gelli, N.; Vardaci, E.

    2017-06-01

    In the recent years, cluster structures have been evidenced in many ground and excited states of light nuclei [1, 2]. In the currently experimental campaign, the NUCL-EX collaboration has measured the12C+12C and14N+10B reactions at 95 MeV and 80 MeV respectively. The experimental data corresponding to complete fusion of target and projectile into an excited24Mg nucleus was compared to the results of a pure statistical model [3, 4]. In addition, data from12C+12C have been analyzed to investigate the decay of the Hoyle state of12C* [12] obtained as an intermediate step in the 6α decay channel of the24Mg* formed in central events.

  13. Reaction-Based SiC Materials for Joining Silicon Carbide Composites for Fusion Energy

    SciTech Connect

    Lewinsohn, Charles A.; Jones, Russell H.; Singh, M.; Serizawa, H.; Katoh, Y.; Kohyama, A.

    2000-09-01

    The fabrication of large or complex silicon carbide-fiber-reinforced silicon carbide (SiC/SiC) components for fusion energy systems requires a method to assemble smaller components that are limited in size by manufacturing constraints. Previous analysis indicates that silicon carbide should be considered as candidate joint materials. Two methods to obtain SiC joints rely on a reaction between silicon and carbon to produce silicon carbide. This report summarizes preliminary mechanical properties of joints formed by these two methods. The methods appear to provide similar mechanical properties. Both the test methods and materials are preliminary in design and require further optimization. In an effort to determine how the mechanical test data is influenced by the test methodology and specimen size, plans for detailed finite element modeling (FEM) are presented.

  14. Measurements of charged fusion product diffusion in TFTR

    SciTech Connect

    Boivin, Rejean Louis

    1991-12-01

    The single particle confinement of charged fusion products, namely the 1 MeV triton and the 3 MeV proton, has been studied using a detector located near the outer midplane of TFTR. The detector, which measure the flux of escaping particles, is composed of a scintillator [ZnS(Ag)] and a system of collimating apertures, which permit pitch angle, energy and time resolution. It is mounted on a movable probe which can be inserted 25 cm into the vacuum vessel. Measurements indicate a level of losses higher than expected from a first-orbit loss mechanism alone. The primary candidate for explaining the observed anomalous losses is the toroidal field (TF) stochastic ripple diffusion, theoretically discovered by Goldston, White and Boozer. This loss mechanism is expected to be localized near the outer midplane where, at least at high current (≳ 1.0 MA) it would locally dominate over first-orbit losses. Calculations made with a mapping particle orbit code (MAPLOS) show a semi-quantitative agreement with the measurements. The predominant uncertainties in the numerical simulations were found to originate from the modeling of the first wall geometry and also from the assumed plasma current and source profiles. Direct measurements of the diffusion rate were performed by shadowing the detector with a second movable probe used as an obstacle. The diffusion rate was also measured by moving the detector behind the radius of the RF limiters, located on the outer wall. Comparisons of these experimental results with numerical simulations, which include diffusive mechanisms, indicate a quantitative agreement with the TF stochastic ripple diffusion model.

  15. Measurements of charged fusion product diffusion in TFTR

    SciTech Connect

    Boivin, R.L.

    1991-12-01

    The single particle confinement of charged fusion products, namely the 1 MeV triton and the 3 MeV proton, has been studied using a detector located near the outer midplane of TFTR. The detector, which measure the flux of escaping particles, is composed of a scintillator (ZnS(Ag)) and a system of collimating apertures, which permit pitch angle, energy and time resolution. It is mounted on a movable probe which can be inserted 25 cm into the vacuum vessel. Measurements indicate a level of losses higher than expected from a first-orbit loss mechanism alone. The primary candidate for explaining the observed anomalous losses is the toroidal field (TF) stochastic ripple diffusion, theoretically discovered by Goldston, White and Boozer. This loss mechanism is expected to be localized near the outer midplane where, at least at high current ({approx gt} 1.0 MA) it would locally dominate over first-orbit losses. Calculations made with a mapping particle orbit code (MAPLOS) show a semi-quantitative agreement with the measurements. The predominant uncertainties in the numerical simulations were found to originate from the modeling of the first wall geometry and also from the assumed plasma current and source profiles. Direct measurements of the diffusion rate were performed by shadowing the detector with a second movable probe used as an obstacle. The diffusion rate was also measured by moving the detector behind the radius of the RF limiters, located on the outer wall. Comparisons of these experimental results with numerical simulations, which include diffusive mechanisms, indicate a quantitative agreement with the TF stochastic ripple diffusion model.

  16. Production of pesticide metabolites by oxidative reactions.

    PubMed

    Hodgson, E

    1982-08-01

    The cytochrome P-450-dependent monooxygenase system catalyzes a wide variety of oxidations of pesticide chemicals and related compounds. These reactions include epoxidation and aromatic hydroxylation, aliphatic hydroxylation, O-, N- and S-dealkylation, N-oxidation, oxidative deamination, S-oxidation, P-oxidation, desulfuration and ester cleavage and may result in either detoxication or activation of the pesticide. The current status of such reactions, relative to the production, in vivo, of biologically active intermediates in pesticide metabolism is summarized. More recently we have shown that the FAD-containing monooxygenase of mammalian liver (E.C.1.14.13.8), a xenobiotic metabolizing enzyme of broad specificity formerly known as an amine oxidase, is involved in a variety of pesticide oxidations. These include sulfoxidation of organophosphorus insecticides such as phorate and disulfoton, oxidative desulfuration of phosphonate insecticides such as fonofos and oxidation at the phosphorus atom in such compounds as the cotton defoliant, folex. The relative importance of the FAD-containing monooxygenase vis-a-vis the cytochrome P-450-dependent monooxygenase system is discussed, based on in vitro studies on purified enzymes.

  17. Reactions of uranium hexafluoride photolysis products

    NASA Astrophysics Data System (ADS)

    Lyman, John L.; Laguna, Glenn; Greiner, N. R.

    1985-01-01

    This paper confirms that the ultraviolet photolysis reactions of UF6 in the B band spectral region is simple bond cleavage to UF5 and F. The photolysis products may either recombine to UF6 or the UF5 may dimerize, and ultimately polymerize, to solid UF5 particles. We use four methods to set an upper limit for the rate constant for recombination of kr<2.0×10-12cm3 molecule-1 s-1. We measure the rate constant for UF5 dimerization to be kd=(1.0±0.2)×10-11 cm3 molecule-1 s-1. The principal method employed in these studies is the use of diode lasers to monitor, in real time, the changes in density of the species UF6 and UF5 after laser photolysis of the UF6 gas sample.

  18. Advanced fusion welding processes, solid state joining and a successful marriage. [production of aerospace structures

    NASA Technical Reports Server (NTRS)

    Miller, F. R.

    1972-01-01

    Joining processes for aerospace systems combine fusion welding and solid state joining during production of metal structures. Detailed characteristics of electron beam welding, plasma arc welding, diffusion welding, inertia welding and weldbond processes are discussed.

  19. Particle emission in the light heavy-ion fusion reactions: 14N, 16,18O+ 12C

    NASA Astrophysics Data System (ADS)

    Carlin Filho, N.; Coimbra, M. M.; Acquadro, J. C.; Liguori Neto, R.; Szanto, E. M.; Farrelly-Pessoa, E.; Szanto de Toledo, A.

    1985-01-01

    From the energy spectra of light particles produced in light-heavy-ion-induced reactions, level densities of the final nuclei as well as the critical angular momenta for fusion may be obtained. The 14N, 16,18O+ 12C reactions were investigated in the energy range 30 MeVfusion critical angular momentum (Jcr), offering an alternative method for the total fusion cross-section determination.

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

    NASA Astrophysics Data System (ADS)

    Hayakawa, S.; Spitaleri, C.; Burtebayev, N.; Aimaganbetov, A.; Figuera, P.; Fisichella, M.; Guardo, G. L.; Igamov, S.; Indelicato, I.; Kiss, G.; Kliczewski, S.; La Cognata, M.; Lamia, L.; Lattuada, M.; Piasecki, E.; Rapisarda, G. G.; Romano, S.; Sakuta, S. B.; Siudak, R.; Trzcińska, A.; Tumino, A.; Urkinbayev, A.

    2016-05-01

    The 16O+16O fusion reaction is important in terms of the explosive oxygen burning process during late evolution stage of massive stars as well as understanding of the mechanism of low-energy heavy-ion fusion reactions. We aim to determine the excitation function for the most major exit channels, α+28Si and p+31P, toward stellar energies indirectly by the Trojan Horse Method via the 16O(20Ne, α28Si)α and 16O(20Ne, p31P)α three-body reactions. We report preliminary results involving reaction identification, and determination of the momentum distribution of α-16O intercluster motion in the projectile 20Ne nucleus.

  1. 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.

  2. 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

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

    NASA Astrophysics Data System (ADS)

    Giaz, Agnese; Corsi, Anna; Camera, Franco; Wieland, Oliver; Kravchuk, Vladimir L.; Barlini, Sandro; Alba, Rosa; Bednarczyk, P.; Bracco, Angela; Baiocco, Giorgio; Bardelli, Luigi; Benzoni, Giovanna; Bini, M.; Blasi, Nives; Brambilla, Sergio; Bruno, Mauro; Casini, Giovanni; Ciemala, Michal; Cinausero, Marco; Chiari, M.; Colonna, Maria; Crespi, Fabio Celso Luigi; D'Agostino, Michela; Degerlier, Meltem; Di Toro, Massimo; Gramegna, Fabiana; Kmiecik, Maria; Leoni, Silvia; Maiolino, C.; Maj, Adam; Marchi, Tommaso; Mazurek, K.; Meczynski, W.; Million, Benedicte; Montanari, Daniele; Morelli, Luca; Nannini, Adriana; Nicolini, Roberto; Pasquali, G.; Piantelli, S.; Ordine, A.; Poggi, Giacomo; Rizzi, V.; Rizzo, Carmelo; Santonocito, Domenico; Vandone, Valeria; Vannini, G.

    2014-03-01

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

  4. Electroweak meson production reaction in the nucleon resonance region

    SciTech Connect

    Sato, Toru

    2015-10-15

    We report on our recent study of the the neutrino-nucleon reaction in the nucleon resonance region. The dynamical reaction model of meson production reaction on the nucleon for the pion and photon induced reaction has been developed in order to investigate the spectrum of nucleon excited state. We have extended this model in order to describe the weak meson production reactions with the πN, ηN, KΛ, KΣ and ππN final states. We also studied the role of the final state interaction in the photon and the neutrino induced pion production reaction on the deuteron around the Δ(1232) resonance region.

  5. Synthesis of superheavy element 120 via {sup 50}Ti+{sup A}Cf hot fusion reactions

    SciTech Connect

    Liu, Z. H.; Bao Jingdong

    2009-11-15

    Synthesis of superheavy element 120 in terms of the {sup 50}Ti+{sup 249-252}Cf fusion-evaporation reactions is evaluated and discussed. It is found that the reactions of {sup 250,251}Cf({sup 50}Ti,3n){sup 297,298}120 and {sup 251,252}Cf({sup 50}Ti,4n){sup 297,298}120 are relatively favorable with the maximum evaporation-residue cross sections of 0.12, 0.09, 0.11, and 0.25 pb, respectively. However, {sup 252}Cf may be difficult to be target because its spontaneous fission will bring about serious background in the experiment. Fusion probabilities for different target-projectile combinations leading to the formation of surperheavy nucleus {sup 302}120 are estimated with the ''fusion-by-diffusion'' model and presented as a function of the Coulomb parameter Z{sub 1}Z{sub 2}/(A{sub 1}{sup 1/3}+A{sub 2}{sup 1/3}). Among the reactions {sup 50}Ti+{sup 252}Cf, {sup 54}Cr+{sup 248}Cm, {sup 58}Fe+{sup 244}Pu, and {sup 64}Ni+{sup 238}U, the reaction {sup 50}Ti+{sup 252}Cf has the largest fusion probability. Synthesis of superheavy element 120 is of essential importance for determining whether the magic proton shell should be at Z=114 or at higher proton numbers Z=120-126. Therefore, the experiment to produce isotopes with Z=120 in the fusion reactions {sup 50}Ti+{sup 250,251}Cf is of great interest.

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  7. A protein disulfide isomerase gene fusion expression system that increases the extracellular productivity of Bacillus brevis.

    PubMed

    Kajino, T; Ohto, C; Muramatsu, M; Obata, S; Udaka, S; Yamada, Y; Takahashi, H

    2000-02-01

    We have developed a versatile Bacillus brevis expression and secretion system based on the use of fungal protein disulfide isomerase (PDI) as a gene fusion partner. Fusion with PDI increased the extracellular production of heterologous proteins (light chain of immunoglobulin G, 8-fold; geranylgeranyl pyrophosphate synthase, 12-fold). Linkage to PDI prevented the aggregation of the secreted proteins, resulting in high-level accumulation of fusion proteins in soluble and biologically active forms. We also show that the disulfide isomerase activity of PDI in a fusion protein is responsible for the suppression of the aggregation of the protein with intradisulfide, whereas aggregation of the protein without intradisulfide was prevented even when the protein was fused to a mutant PDI whose two active sites were disrupted, suggesting that another PDI function, such as chaperone-like activity, synergistically prevented the aggregation of heterologous proteins in the PDI fusion expression system.

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

    SciTech Connect

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

    2016-07-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  10. Compactness of the {sup 48}Ca induced hot fusion reactions and the magnitudes of quadrupole and hexadecapole deformations

    SciTech Connect

    Gupta, Raj K.; Manhas, Monika; Greiner, Walter

    2006-05-15

    Based on fragmentation theory extended to include the orientation degrees of freedom and higher multipole deformations up to hexadecapole deformations, the compactness of {sup 48}Ca induced reactions on various actinides is studied for Ds (Z=110) to 118 nuclei. It is shown that the reactions leading to Z{>=}114 nuclei are 'compact' hot fusion reactions at {theta}=90 deg. orientation angles (equatorial compact or ec; collisions that are in the direction of the minor axis of the deformed reaction partner), but the ones for Z<114 nuclei are compact at {theta}<90 deg. (not-equatorial compact or nec). The phenomenon of 'barrier distribution in orientation degrees of freedom' is observed for the first time to be related to the magnitudes of both the quadrupole and hexadecapole deformations of the deformed reaction partner. The ec configurations are obtained for the cases of quadrupole deformation alone and with small (including negative values) hexadecapole deformations. The presence of large (positive) hexadecapole deformations result in the nec configurations. These results are found to be quite general, applicable also to other lighter targets such as W and Ra with the {sup 48}Ca beam and to Pb based reactions. Furthermore, for compact hot fusion reactions, in addition to the {sup 48}Ca reaction valley, a number of other new reaction valleys (target-projectile combinations) are obtained, the most important one (next to {sup 48}Ca) being the {sup 54}Ti nucleus used previously in Pb based cold fusion reaction studies but now proposed with deformed actinide nuclei such as {sup 226}Ra, {sup 232}Th, {sup 238}U, and {sup 242}Pu.

  11. Magneized target fusion: An overview of the concept

    SciTech Connect

    Kirkpatrick, R.C.

    1994-12-31

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

  12. Electropionics and fusion

    SciTech Connect

    Kenny, J.P. )

    1991-05-01

    This paper reports on the electropionic mass formula which does not differentiate between nuclei and elementary particles, but gives the deuteron a unique bifurcated space-time description. This hints at fusion products produced by anomalous intermediate mass states of 3026, 3194, and 3515 MeV/c{sup 2} that then decay to produce energy. Another unique possibility in electropionics is that no fusion of deuterons occurs, but the deuteron is changed by electron capture into a D-meson that then decays to produce observed cold fusion energies. All these cold fusion electropionic reactions violate baryon conservation but do produce energy yields consistent with reported cold fusion decay products and energy levels.

  13. Cross sections of the (HI, αn) channel in the cold-fusion-type reactions 209Bi+ 40Ar and 208Pb+ 37Cl

    NASA Astrophysics Data System (ADS)

    Lazarev, Yu. A.; Oganessian, Yu. Ts.; Szeglowki, Z.; Utyonkov, V. K.; Kharitonov, Yu. P.; Constantinescu, O.; Liên, Dinh Thi; Shirokovsky, I. V.; Tretyakova, S. P.

    1994-11-01

    By applying an off-line radiochemistry technique, cross sections for the production of the isotope 240Cm(T {1}/{2}=27 d) in the cold-fusion-type reactions 209Bi+ 40Ar and 208Pb+ 37Cl at the bombarding energy Elab⩽230 MeV were determined to be 0.5±0.2 nb and 0.6±0.3 nb, respectively. The production of 240Cm was attributed to the 1n-deexcitation channel of the composite systems 249Md and 245Es. At the same time, the measured 240Cm production cross sections represent upper cross-section limits for the (HI, αn) channel of the reactions under study. These upper limits are about 100 times lower than the cross-section values reported recently by Nomura et al. for the ( 40Ar, αx n) channels with x=1,2 of the 209Bi+ 40Ar reaction at Elab=208 MeV. In the context of the above measurements, presented and discussed is the up-to-date summary of the available evidence on cross sections of the (HI, αxn) channels in the cold-fusion-type reactions induced by projectiles ranging from 37Cl to 50Ti on targets of 203,205Tl, 208Pb, and 209Bi nuclei. Appreciable EC(β +)-delayed or/and spontaneous fission effects were detected in the 209Bi+ 40Ar, 208Pb+ 37Cl, and 206Pb+ 37Cl reactions. The obtained data point, in particular, to the EC(β +)-delayed fission occuring in the decay chains ? and ?.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  15. Reply to ‘Comment “On the fusion triple product and fusion power gain of tokamak pilot plants and reactors”’

    NASA Astrophysics Data System (ADS)

    Costley, A. E.; Buxton, P. F.; Hugill, J.

    2017-03-01

    In reply to the Comment by Biel et al (2016 Nucl. Fusion 57 038001) on our recent papers Costley et al (2015 Nucl Fusion 55 033001) and Costley (2016 Nucl. Fusion 56 066003), we point out that the fusion triple product, nTτ E, and fusion power gain, Q fus, cannot be expressed solely in terms of independent engineering design variables such as major radius, R, and toroidal field, B; output performance variables such as normalised beta, β N, safety factor, q, and fusion power P fus, have to be invoked. Further, we show that the density limit has the effect of largely cancelling the size dependence in nTτ E and Q fus, which would otherwise be present, when these parameters are expressed in terms of P fus. Considerations of engineering aspects are also briefly discussed.

  16. Intracellular protein production in Trichoderma reesei (Hypocrea jecorina) with hydrophobin fusion technology.

    PubMed

    Mustalahti, Eero; Saloheimo, Markku; Joensuu, Jussi Joonas

    2013-01-25

    Insufficient accumulation and the lack of efficient purification methods are the two major bottlenecks hindering the recombinant production of many proteins. Alternative production schemes are urgently needed for proteins that remain challenging to express and purify with conventional techniques. We have found that hydrophobin fusions targeted to endoplasmic reticulum (ER) can enhance the expression of target proteins simultaneously providing means for straightforward purification. Here we show that hydrophobin fusion technology induces formation of large protein bodies in the filamentous fungus Trichoderma reesei. The fusion protein remained soluble in the ER-derived protein bodies. A simple and scalable aqueous two-phase system was demonstrated to purify the hydrophobin fusion protein GFP-HFBI from the complex intracellular extracts with a recovery of up to 62%. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Energy distribution among reaction products. V.

    NASA Technical Reports Server (NTRS)

    Anlauf, K. G.; Horne, D. S.; Macdonald, R. G.; Polanyi, J. C.; Woodall, K. B.

    1972-01-01

    Discussion of three reactions, one point of theoretical interest being the predicted correlation between barrier height and barrier location. The H + Br 2 reaction having a lower activation barrier than H + Cl 2, should have an earlier barrier, and hence a greater percentage attractive energy release and higher efficiency of vibrational excitation. Information is developed concerning the effect of isotopic substitution in the pair of reactions H + Cl 2 and D + Cl 2. The 'arrested relaxation' method was used. Essentially, the method involves reacting two diffuse reagent beams in a reaction vessel with background pressure less than 0.001 torr, and with walls cooled by liquid nitrogen or liquid helium.

  18. Calculated cross sections for production and destruction of some long-lived nuclides of importance in fusion energy applications

    SciTech Connect

    Gardner, M.A.; Gardner, D.G.

    1993-07-08

    Knowledge of the production and destruction of long-lived species via neutrons, photons, and charged-particles is required in many fusion energy applications, such as reactor first-wall and blanket design, radioactive waste management, etc. Here we describe our calculational results for the production, via the (n,2n) reaction, of the following long-lived species: {sup 150}Eu(t{sub 1/2} = 36 y), {sup 152}Eu(t{sub 1/2} = 13 y), and {sup 192m2}Ir(t{sub 1/2} = 241 y). Some comments on calculations that we`ve made for destruction reactions of these species are also included.

  19. Laser-plasma energetic particle production for aneutronic nuclear fusion experiments

    NASA Astrophysics Data System (ADS)

    Giulietti, D.; Andreoli, P.; Batani, D.; Bonasera, A.; Boutoux, G.; Burgy, F.; Cipriani, M.; Consoli, F.; Cristofari, G.; De Angelis, R.; Di Giorgio, G.; Ducret, J. E.; Ingenito, F.; Jakubowska, K.; Verona, C.; Verona-Rinati, G.

    2017-07-01

    Protons at energies up to a few hundreds of keV have been accelerated, by irradiating thin Al foils with an intense, fs laser pulses. The produced energetic protons, directed on a massive natural Boron sample, induced (p + 11B) fusion reactions accompanied by alpha particles emission, detected by a CR39 plate.

  20. 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.

  1. Making genes green: creating green fluorescent protein (GFP) fusions with blunt-end PCR products.

    PubMed

    Lo, W; Rodgers, W; Hughes, T

    1998-07-01

    The jellyfish green fluorescent protein (GFP) has proven to be a useful tool in protein localization and trafficking studies. Fused to GFP, a protein of interest can be visualized and tracked in vivo through fluorescence microscopy. However, the process of making these fusion proteins is often tedious and painstaking. Here, we describe a simple and quick method for creating GFP fusion proteins using blunt-end PCR product ligation.

  2. Double Higgs Boson Production via WW Fusion in TeV e+e- Collisions

    NASA Astrophysics Data System (ADS)

    Barger, V.; Han, T.

    The production of two standard model Higgs bosons via the WW fusion process e+e- → bar ve ve HH would test the predicted HHH, HWW and HHWW couplings. At TeV energies this fusion cross section dominates over that from e+e- →ZHH and would give significant event rates for mH ≲ 1/2 MZ at high luminosity e+e- colliders. We evaluate the rates and present the dynamical distributions.

  3. Position-sensitive coincidence detection of nuclear reaction products at the Prague Van-de-Graaff accelerator

    NASA Astrophysics Data System (ADS)

    Granja, Carlos; Kraus, Vaclav; Pugatch, Valery; Kohout, Zdenek

    2017-06-01

    In low-energy nuclear reactions of astrophysical interest or fusion studies the spatial- and time-correlated detection of two and more reaction products can be a valuable tool in studies of reaction mechanisms, resolving reaction channels and measuring angular distributions of reaction products. For this purpose we constructed a configurable array of position-sensitive detectors based on the hybrid semiconductor pixel detector Timepix. Additional analog-signal electronics provide self-trigger together with extended multi-device control and synchronized readout electronics by a customized control and coincidence unit. The instrumentation, developed and used for detection of fission fragments in spontaneous and neutron induced fission as well as in charged particle detection in neutron induced reactions, is being implemented for low-energy light-ion induced nuclear reactions. Application and demonstration of the technique with two Timepix detectors on p+p elastic scattering at the Van-de-Graaff (VdG) accelerator in Prague is given.

  4. Soft Fusion Energy Path: Isotope Production in Energy Subcritical/Economy Hypercritical D +D Colliding-Beam Mini Fusion Reactor `Exyder'

    NASA Astrophysics Data System (ADS)

    Hester, Tim; Maglich, Bogdan; Calsec Collaboration

    2015-03-01

    Bethe1 and Sakharov2 argued for soft fusion energy path via isotope production, substantiated by Manheimer3. - Copious T and 3He production4 , 5 from D(d, p) T and D(d, n) 3He reactions in 725 KeV D +D colliding beams was measured in weak-focusing Self-Collider6 , 7 radius 0.15 m, in B = 3.12 T, non-linearly stabilized by electron cloud oscillations8 to confinement time = 24 s. Simulations6 predict that by switching to strong focusing9, 10 deuterons 0.75 MeV each, generate 1 3He +1T +1p + 1n at total input energy cost 10.72 MeV. Economic value of T and 3He is 65 and 120 MeV/atom, respectively. We obtain economic gain 205MeV/10.72 MeV ~ 2,000% i.e. 3He production funds cost of T. If first wall is made of Thorium n's will breed 233U releasing 200 MeV/fission, at neutron cost 5.36 MeV versus 160 MeV in beam on target, resulting in no cost 3He production, valued 75K/g. 1. Physics Today, May 1979, p.44; 2. Memoirs, Vintage Books, (1992); 3. Phys. Today, May 2012 p. 12; 4. Phys. Rev. Lett. 54, 796 (1985); 5. Bull. APS, 57, No. 3 (2012); 6. Part. Acc.1, (1970); 7. ANEUTRONIC FUSION NIM A 271 1-167 (1988); 8. Phys. Rev. Lett. 70, 1818 (1993); 9. Part. Acc. 34, 13 (1990).

  5. Mitofusin 1 and 2 play distinct roles in mitochondrial fusion reactions via GTPase activity.

    PubMed

    Ishihara, Naotada; Eura, Yuka; Mihara, Katsuyoshi

    2004-12-15

    The mammalian homologues of yeast and Drosophila Fzo, mitofusin (Mfn) 1 and 2, are both essential for mitochondrial fusion and maintenance of mitochondrial morphology. Though the GTPase domain is required for Mfn protein function, the molecular mechanisms of the GTPase-dependent reaction as well as the functional division of the two Mfn proteins are unknown. To examine the function of Mfn proteins, tethering of mitochondrial membranes was measured in vitro by fluorescence microscopy using green fluorescence protein- or red fluorescent protein-tagged and Mfn1-expressing mitochondria, or by immunoprecipitation using mitochondria harboring HA- or FLAG-tagged Mfn proteins. These experiments revealed that Mfn1-harboring mitochondria were efficiently tethered in a GTP-dependent manner, whereas Mfn2-harboring mitochondria were tethered with only low efficiency. Sucrose density gradient centrifugation followed by co-immunoprecipitation revealed that Mfn1 produced oligomerized approximately 250 kDa and approximately 450 kDa complexes in a GTP-dependent manner. The approximately 450 kDa complex contained oligomerized Mfn1 from distinct apposing membranes (docking complex), whereas the approximately 250 kDa complex was composed of Mfn1 present on the same membrane or in the membrane-solubilized state (cis complex). These results were also confirmed using blue-native PAGE. Mfn1 exhibited higher activity for this reaction than Mfn2. Purified recombinant Mfn1 exhibited approximately eightfold higher GTPase activity than Mfn2. These findings indicate that the two Mfn proteins have distinct activities, and suggest that Mfn1 is mainly responsible for GTP-dependent membrane tethering.

  6. Tumor Growth Prediction with Reaction-Diffusion and Hyperelastic Biomechanical Model by Physiological Data Fusion

    PubMed Central

    Wong, Ken C. L.; Summers, Ronald M.; Kebebew, Electron; Yao, Jianhua

    2015-01-01

    The goal of tumor growth prediction is to model the tumor growth process, which can be achieved by physiological modeling and model personalization from clinical measurements. Although image-driven frameworks have been proposed with promising results, several issues such as infinitesimal strain assumptions, complicated personalization procedures, and the lack of functional information, may limit their prediction accuracy. In view of these issues, we propose a framework for pancreatic neuroendocrine tumor growth prediction, which comprises a FEM-based tumor growth model with coupled reaction-diffusion equation and nonlinear biomechanics. Physiological data fusion of structural and functional images is used to improve the subject-specificity of model personalization, and a derivative-free global optimization algorithm is adopted to facilitate the complicated model and accommodate flexible choices of objective functions. With this flexibility, we propose an objective function accounting for both the tumor volume difference and the root-mean-squared error of intracellular volume fractions. Experiments were performed on synthetic and clinical data to verify the parameter estimation capability and the prediction performance. Comparisons of using different biomechanical models and objective functions were also performed. From the experimental results of eight patient data sets, the average recall, precision, Dice coefficient, and relative volume difference between predicted and measured tumor volumes were 84.5±6.9%, 85.8±8.2%, 84.6±1.7%, and 14.2±8.4%, respectively. PMID:25962846

  7. 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.

  8. Compound nucleus formation probability PCN determined within the dynamical cluster-decay model for various "hot" fusion reactions

    NASA Astrophysics Data System (ADS)

    Kaur, Arshdeep; Chopra, Sahila; Gupta, Raj K.

    2014-08-01

    The compound nucleus (CN) fusion/formation probability PCN is defined and its detailed variations with the CN excitation energy E*, center-of-mass energy Ec .m., fissility parameter χ, CN mass number ACN, and Coulomb interaction parameter Z1Z2 are studied for the first time within the dynamical cluster-decay model (DCM). The model is a nonstatistical description of the decay of a CN to all possible processes. The (total) fusion cross section σfusion is the sum of the CN and noncompound nucleus (nCN) decay cross sections, each calculated as the dynamical fragmentation process. The CN cross section σCN is constituted of evaporation residues and fusion-fission, including intermediate-mass fragments, each calculated for all contributing decay fragments (A1, A2) in terms of their formation and barrier penetration probabilities P0 and P. The nCN cross section σnCN is determined as the quasi-fission (qf) process, where P0=1 and P is calculated for the entrance-channel nuclei. The DCM, with effects of deformations and orientations of nuclei included in it, is used to study the PCN for about a dozen "hot" fusion reactions forming a CN of mass number A ˜100 to superheavy nuclei and for various different nuclear interaction potentials. Interesting results are that PCN=1 for complete fusion, but PCN<1 or PCN≪1 due to the nCN contribution, depending strongly on different parameters of the entrance-channel reaction but found to be independent of the nuclear interaction potentials used.

  9. Simulation and Experimental Study on the Efficiency of Traveling Wave Direct Energy Conversion for Application to Aneutronic Fusion Reactions

    NASA Astrophysics Data System (ADS)

    Tarditi, Alfonso; Chap, Andrew; Miley, George; Scott, John

    2013-10-01

    A study based on both Particle-in-cell (PIC) simulation and experiments is being developed to study the physics of the Traveling Wave Direct Energy Converter (TWDEC,) with the perspective of application to aneutronic fusion reaction products and space propulsion. The PIC model is investigating in detail the key TWDEC physics process by simulating the time-dependent transfer of energy from the ion beam to an electric load connected to ring-type electrodes in cylindrical symmetry. An experimental effort is in progress on a TWDEC test article at NASA, Johnson Space Center with the purpose of studying the conditions for improving the efficiency of the direct energy conversion process. Using a scaled-down ion energy source, the experiment is primarily focused on the effect of the (bunched) beam density on the efficiency and on the optimization of the electrode design. The simulation model is guiding the development of the experimental configuration and will provide details of the beam dynamics for direct comparison with experimental diagnostics. Work supported by NASA, Johnson Space Center.

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

    NASA Astrophysics Data System (ADS)

    Romanelli, Gherardo; Mignone, Andrea; Cervone, Angelo

    2017-10-01

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

  11. Productions of heavy charged leptons via gluon fusion at the LHC: A revisit

    SciTech Connect

    Liu Chun; Yang Shuo

    2010-05-01

    Heavy charged lepton productions via gluon fusion at the LHC are revisited. Full loop calculations are adopted with an updated parton distribution function and electroweak data. Including contribution from new generation quarks in the loop, pair production of the sequential heavy lepton via gluon fusion at the LHC dominates over that via the Drell-Yan mechanism in some heavy lepton mass range. Exotic lepton single production of vectorlike lepton extended models is also calculated. In the later case, the gluon fusion mechanism via the Higgs exchange is emphasized. Our numerical results for both pair and single production of heavy leptons are smaller than previous studies especially for a large heavy lepton mass as a result of full loop calculation and due to the mixing angles.

  12. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    SciTech Connect

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in the critical reactors

  13. An insight into fusion technology aiding efficient recombinant protein production for functional proteomics.

    PubMed

    Yadav, Dinesh K; Yadav, Neelam; Yadav, Sarika; Haque, Shafiul; Tuteja, Narendra

    2016-12-15

    Advancements in peptide fusion technologies to maximize the protein production has taken a big leap to fulfill the demands of post-genomics era targeting elucidation of structure/function of the proteome and its therapeutic applications, by over-expression in heterologous expression systems. Despite being most preferred protein expression system armed with variety of cardinal fusion tags, expression of the functionally active recombinant protein in E. coli remains plagued. The present review critically analyses the aptness of well-characterized fusion tags utilized for over-expression of recombinant proteins with improved solubility and their compatibility with downstream purification procedures. The combinatorial tandem affinity strategies have shown to provide more versatile options. Solubility decreasing fusion tags have proved to facilitate the overproduction of antimicrobial peptides. Efficient removal of fusion tags prior to final usage is of utmost importance and has been summarized discussing the efficiency of various enzymatic and chemical methods of tag removal. Unfortunately, no single fusion tag works as a magic bullet to completely fulfill the requirements of protein expression and purification in active form. The information provided might help in selection and development of a successful protocol for efficient recombinant protein production for functional proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Traveling-Wave Direct Energy Converter for Fusion Products

    NASA Astrophysics Data System (ADS)

    Sato, Kunihiro; Katayama, Hideaki

    1999-11-01

    A Traveling-Wave Direct Energy Converter (TWDEC), which is designed to recover kinetic energy of fusion protons escaped from a FRC/ D^3He fusion reactor, is studied by numerical calculation and computer simulation. To develop a simulation code, a transmission line loop for an electrostatic traveling wave is designed using lumped constant elements L, C, R. Electrostatic coupling between proton beam and circuits is treated by directly solving Poisson's equation. Circuit equations are transformed to temporal finite-difference equations, which are solved following the leap-flog scheme. Simulation results display desirable performance characteristics of the TWDEC. Traveling wave with a fixed frequency is excited spontaneously without any external electric power supply. High energy conversion rate of the TWDEC up to 0.8 is obtained both from orbit calculation and from computer simulation as a result of improvement of proton beam bunching. The wave keeps its equilibrium state under loading, and the wave responds to variation of the electric load stably.

  15. Excitation functions for {sup 208-211}Fr produced in the {sup 18}O+{sup 197}Au fusion reaction

    SciTech Connect

    Corradi, L.; Behera, B.R.; Fioretto, E.; Gadea, A.; Latina, A.; Stefanini, A.M.; Szilner, S.; Trotta, M.; Wu, Y.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Sagaidak, R.N.; Atutov, S.N.; Mai, B.; Stancari, G.; Tomassetti, L.; Mariotti, E.; Khanbekyan, A.; Veronesi, S.

    2005-01-01

    Excitation functions for {sup 208-211}Fr isotopes produced in the {sup 18}O+{sup 197}Au fusion-evaporation reaction have been measured at E{sub lab}=75-130 MeV via characteristic {alpha} decays by means of an electrostatic deflector and a semiconductor detector. Data have been compared with calculations giving barrier-passing (capture) cross sections and probabilities of the compound nucleus decay into different channels according to the standard statistical model.

  16. Products of the reaction of chlorine atoms and ozone

    NASA Technical Reports Server (NTRS)

    Hall, J. H., Jr.; Merideth, C. W.; Bhatia, S.; Guillory, W. A.; Gayles, J. N.

    1976-01-01

    Preliminary matrix-isolation infrared spectroscopic studies of the gas-phase reaction of chlorine atoms and ozone are reported. It was shown that the major product of the reaction is the symmetric OClO radical, while very little of the asymmetric ClOO radical is produced. It was also shown that the presence of O2 enhances the OClO production and the ClOO is the primary product in the reaction of Cl atoms and pure O2. The radical ClO was observed for the first time in a gas-phase reaction of Cl and O3. A mechanism for these observations is proposed.

  17. Performance requirements of an inertial-fusion-energy source for hydrogen production

    SciTech Connect

    Hovingh, J.

    1983-01-01

    Performance of an inertial fusion system for the production of hydrogen is compared to a tandem-mirror-system hydrogen producer. Both systems use the General Atomic sulfur-iodine hydrogen-production cycle and produce no net electric power to the grid. An ICF-driven hydrogen producer will have higher system gains and lower electrical-consumption ratios than the design point for the tandem-mirror system if the inertial-fusion-energy gain eta Q > 8.8. For the ICF system to have a higher hydrogen production rate per unit fusion power than the tandem-mirror system requires that eta Q > 17. These can be achieved utilizing realistic laser and pellet performances.

  18. Anomalous delayed loss of trapped D-D fusion products in TFTR

    SciTech Connect

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.

    1993-02-01

    A new anomalous delayed loss of D-D fusion products has been measured at the bottom of the TFRR vessel. This loss is delayed by [approximately] 0.2 sec with respect to the usual prompt first-orbit loss, and has a correspondingly lower energy, i.e. about half the fusion product birth energy. This loss process dominates the total fusion product loss measured 90[degrees] below the midplane for plasma currents. I[ge] 1.8 MA and major radii near R=2.45 m, e.g. for recent TFTR supershots. This delayed feature can occur without large coherent MED activity, although it can be strongly modulated by such activity. Several possible causes for this phenomenon are discussed, but no clear explanation for this delayed loss has yet been found.

  19. Anomalous delayed loss of trapped D-D fusion products in TFTR

    SciTech Connect

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.

    1993-02-01

    A new anomalous delayed loss of D-D fusion products has been measured at the bottom of the TFRR vessel. This loss is delayed by {approximately} 0.2 sec with respect to the usual prompt first-orbit loss, and has a correspondingly lower energy, i.e. about half the fusion product birth energy. This loss process dominates the total fusion product loss measured 90{degrees} below the midplane for plasma currents. I{ge} 1.8 MA and major radii near R=2.45 m, e.g. for recent TFTR supershots. This delayed feature can occur without large coherent MED activity, although it can be strongly modulated by such activity. Several possible causes for this phenomenon are discussed, but no clear explanation for this delayed loss has yet been found.

  20. The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi

    PubMed Central

    Joosten, Vivi; Lokman, Christien; van den Hondel, Cees AMJJ; Punt, Peter J

    2003-01-01

    In this review we will focus on the current status and views concerning the production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi. We will focus on single-chain antibody fragment production (scFv and VHH) by these lower eukaryotes and the possible applications of these proteins. Also the coupling of fragments to relevant enzymes or other components will be discussed. As an example of the fusion protein strategy, the 'magic bullet' approach for industrial applications, will be highlighted. PMID:12605725

  1. The production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi.

    PubMed

    Joosten, Vivi; Lokman, Christien; Van Den Hondel, Cees AMJJ; Punt, Peter J

    2003-01-30

    In this review we will focus on the current status and views concerning the production of antibody fragments and antibody fusion proteins by yeasts and filamentous fungi. We will focus on single-chain antibody fragment production (scFv and VHH) by these lower eukaryotes and the possible applications of these proteins. Also the coupling of fragments to relevant enzymes or other components will be discussed. As an example of the fusion protein strategy, the 'magic bullet' approach for industrial applications, will be highlighted.

  2. Unexpected heterogeneity of BCR-ABL fusion mRNA detected by polymerase chain reaction in Philadelphia chromosome-positive acute lymphoblastic leukemia

    SciTech Connect

    Hooberman, A.L.; Carrino, J.J.; Leibowitz, D.; Rowley, J.D.; Le Beau, M.M.; Arlin, Z.A.; Westbrook, C.A. )

    1989-06-01

    The Philadelphia (Ph{sup 1}) chromosome results in a fusion of portions of the BCR gene from chromosome 22 and the ABL gene from chromosome 9, producing a chimeric BCR-ABL mRNA and protein. In lymphoblastic leukemias, there are two molecular subtypes of the Ph{sup 1} chromosome, one with a rearrangement of the breakpoint cluster region (bcr) of the BCR gene, producing the same 8.5-kilobase BCR-ABL fusion mRNA seen in chronic myelogenous leukemia (CML), and the other, without a bcr rearrangement, producing a 7.0-kilobase BCR-ABL fusion mRNA that is seen only in acute lymphoblastic leukemia (ALL). The authors studied the molecular subtype of the Ph{sup 1} chromosome in 11 cases of Ph{sup 1}-positive ALL, including 2 with a previous diagnosis of CML, using a sensitive method to analyze the mRNA species based on the polymerase chain reaction (PCR). They observed unexpected heterogeneity in BCR-ABL mRNA in this population. They conclude that the PCR gives additional information about the Ph{sup 1} chromosome gene products that cannot be obtained by genomic analysis, but that it cannot be used as the sole means of detection of this chromosomal abnormality in ALL because of the high incidence of false negative results.

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

    NASA Astrophysics Data System (ADS)

    Morelli, L.; Baiocco, G.; D'Agostino, M.; Gulminelli, F.; Bruno, M.; Cinausero, M.; Degerlier, M.; Fabris, D.; Gramegna, F.; Marchi, T.; Barlini, S.; Bini, M.; Casini, G.; Gelli, N.; Olmi, A.; Pasquali, G.; Piantelli, S.; Valdré, S.

    2015-04-01

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

  4. Ion cyclotron emission due to the newly-born fusion products induced fast Alfven wave radiative instabilities in tokamaks

    SciTech Connect

    Arunasalam, V.

    1995-08-01

    The velocity distribution functions of the newly born (t = 0) charged fusion products of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v{sub {parallel}} such that v{sub {perpendicular}} {approx} v{sub {parallel}} {approx} v{sub j} where (M{sub j}V{sub j}{sup 2}/2) = E{sub j}, the directed birth energy of the charged fusion product species j of mass M{sub j}. As the time t progresses these distribution functions will evolve into a Gaussian in velocity with thermal spreadings given by the perpendicular and parallel temperatures T{sub {perpendicular}j}(t) = T{sub {parallel}j}(t) with T{sub j}(t) increasing as t increases and finally reaches an isotropic saturation value of T{sub {perpendicular}j}(t {approx} {tau}{sub j}) = T{sub {parallel}j}(t {approx} {tau}{sub j}) = T{sub j}(t {approx} {tau}{sub j}) {approx} [M{sub j}T{sub d}E{sub j}/(M{sub j} + M)]{sup 1/2}, where T{sub d} is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles, respectively, and {tau}{sub j} {approx} {tau}{sub sj}/4 is the thermalization time of the fusion product species j in the background deuterium plasma and {tau}{sub sj} is the slowing-down time. For times t of the order of {tau}{sub j} their distributions can be approximated by a Gaussian in their total energy. Then for times t {ge} {tau}{sub sj} the velocity distributions of these fusion products will relax towards their appropriate slowing-down distributions. Here the authors will examine the radiative stability of all these distributions. The ion cyclotron emission from energetic ion produced by fusion reactions or neutral beam injection promises to be a useful diagnostic tool.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    SciTech Connect

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

    2015-12-15

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

  7. Production of radioactive nuclides in inverse reaction kinematics

    NASA Astrophysics Data System (ADS)

    Traykov, E.; Rogachevskiy, A.; Bosswell, M.; Dammalapati, U.; Dendooven, P.; Dermois, O. C.; Jungmann, K.; Onderwater, C. J. G.; Sohani, M.; Willmann, L.; Wilschut, H. W.; Young, A. R.

    2007-03-01

    Efficient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for various applications. It is particularly relevant when the isotope of interest is only a few nucleons away from a stable isotope. In this article production via charge exchange and stripping reactions in combination with a magnetic separator is explored. The relation between the separator transmission efficiency, the production yield, and the choice of beam energy is discussed. The results of some exploratory experiments will be presented.

  8. Exploring contributions from incomplete fusion in Li,76+209Bi and Li,76+198Pt reactions

    NASA Astrophysics Data System (ADS)

    Parkar, V. V.; Jha, V.; Kailas, S.

    2016-08-01

    We use the breakup absorption model to simultaneously describe the measured cross sections of complete fusion (CF), incomplete fusion (ICF), and total fusion (TF) in nuclear reactions induced by weakly bound nuclei Li,76 on 209Bi and 198Pt targets. The absorption cross sections are calculated using the continuum discretized coupled channels (CDCC) method with different choices of short-range imaginary potentials to get the ICF, CF, and TF cross sections. It is observed that the cross sections for deuteron ICF / deuteron capture and α ICF / α capture are of similar magnitude, in the case of the 6Li projectile, while the cross sections for the triton ICF / triton capture is more dominant than that of α ICF / α capture in the case of the 7Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross sections, which defines the value of fusion suppression factor, is found to be in agreement with the data available from the literature. The cross-section ratios of CF/TF and ICF/TF show opposite behavior at below-barrier energies the former decreases while the latter increases as the energy is lowered, which shows the dominance of ICF at below-barrier energies. We have also studied the correlation of the ICF cross sections with the noncapture breakup (NCBU) cross sections as a function of energy, which shows that the NCBU is more significant than ICF at below-barrier energies.

  9. Meson Production in p+d Reactions

    NASA Astrophysics Data System (ADS)

    Klimala, W.; Betigeri, M.; Bojowald, J.; Budzanowski, A.; Chatterjee, A.; Ernst, J.; Freindl, L.; Frekers, D.; Garske, W.; Grewer, K.; Hamacher, A.; Ilieva, J.; Jarczyk, L.; Kilian, K.; Kliczewski, S.; Kolev, D.; Kutsarova, T.; Lieb, J.; Machner, H.; Magiera, A.; Nann, H.; Pentchev, L.; Plendl, H. S.; Protic, D.; Razen, B.; von Rossen, P.; Roy, B.; Siudak, R.; Smyrski, J.; Strzalkowski, A.; Tsenov, R.; Zwoll, K.

    2000-10-01

    Differential cross sections of the pd→ 3H π +/ 3He π 0 reactions were measured simultaneously at three beam momenta: 750 MeV/c, 800 MeV/c and 850 MeV/c. The differential cross section of the pd→ 3He η was measured at 1675 MeV/c beam momentum. All measurements cover a wide angular range in the CM system. The experiments were performed at the COSY accelerator in Juelich, Germany, by means of high purity Germanium Wall detector together with the magnetic spectrometer BIG KARL. Estimated cross sections were compared with the predictions of simple theoretical models. In case of isospin symmetric pd→ 3H π +/ 3He π 0 reactions, the average cross section ratio was estimated.

  10. Massive production of nanoparticles via mist reaction

    NASA Astrophysics Data System (ADS)

    Liu, Ran; Liu, Lei; Liu, Jing

    2009-06-01

    A novel conceptual nanoparticle fabrication method is proposed in this paper. It can be easily implemented for the preparation of micro or nanoparticles through a reaction between mists with different specific chemical compounds produced by ultrasonic atomization technology. Ultrasonic atomization is an established technology that easily atomizes liquid to produce very small droplets-in the orders of tens to hundreds of micrometers. The results reveal that metal oxide nanoparticles, such as iron oxide can be massively produced via reactions between metal chlorides and sodium carbonate in an experimental set-up based on physical and chemical principles. The density of the nanoparticle distribution is also investigated and determined to be dependent on the amount of mist reacted and the collection time. Moreover, since the vibrational frequency of ultrasound can be adjusted, we can control the size of micro-droplets of reactants, hence producing particles of different dimensions. Given that the double mist reaction method is easily controllable, environmentally friendly and extremely low in cost, it can potentially become a significant method for making micro/nano particles in the newly emerging field of nanofabrication and integration.

  11. Population of isomeric states in fusion and transfer reactions in beams of loosely bound nuclei near the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Skobelev, N. K.

    2015-07-01

    The influence of the mechanisms of nuclear reactions on the population of 195 m Hg and 197 m Hg(7/2-), 198 m Tl and 196 m Tl(7+), and 196 m Au and 198 m Au(12-) isomeric nuclear states obtained in reactions induced by beams of 3He, 6Li, and 6He weakly bound nuclei is studied. The behavior of excitation functions and high values of isomeric ratios ( δ m/ δ g) for products of nuclear reactions proceeding through a compound nucleus and involving neutron evaporation are explained within statistical models. Reactions in which the emission of charged particles occurs have various isomeric ratios depending on the reaction type. The isomeric ratio is lower in direct transfer reactions involving charged-particle emission than in reactions where the evaporation of charged particles occurs. Reactions accompanied by neutron transfer usually have a lower isomeric ratio, which behaves differently for different direct-reaction types (stripping versus pickup reactions).

  12. Effect of soluble P55 tumour-necrosis factor binding fusion protein on the local Shwartzman and Arthus reactions.

    PubMed Central

    Norman, K. E.; Williams, T. J.; Feldmann, M.; Rossi, A. G.

    1996-01-01

    1. In this study, the effects of a protein synthesis inhibitor, cycloheximide, and a soluble tumour necrosis factor (TNF) binding/IgG fusion protein, p55-sf2, on the priming and challenge stages of the local Shwartzman reaction (LSR) were assessed and compared with their effects on the acute inflammatory response induced by recombinant human tumour necrosis factor-alpha (rhTNF), lipopolysaccharide (LPS) and a reversed passive Arthus (RPA) reaction in rabbit skin. 2. The LSR was induced in skin by giving an intradermal (i.d.) priming injection of LPS followed by two i.v. challenge injections 20 h and 22 h later. Accumulation of 51-Cr-labelled red blood cells and [125I]-albumin were measured at 24 h as markers of haemorrhage and oedema formation, respectively. 3. The RPA reaction was induced in the rabbit by giving i.d. injections of Arthus anti-serum (anti-bovine-gamma-globulin, BGG) followed 5 min later by an i.v. injection of the antigen (BGG). Oedema formation and the accumulation of 111In-labelled neutrophils produced in the RPA reaction and in response to i.d. injection of rhTNF and LPS were measured over the 4 h period after inducing the responses. 4. A single local injection of cycloheximide (10 micrograms/site) did not inhibit neutrophil accumulation or oedema formation produced by 100% Arthus anti-sera. Although LPS injected i.d. induced a marked dose-dependent neutrophil accumulation, there was little associated plasma leakage. Cycloheximide (10 micrograms/site) did not significantly inhibit the neutrophil accumulation induced by LPS (0.1 microgram/site). In the LSR, priming i.d. injections of LPS caused a dose-dependent increase in haemorrhage and plasma leakage at skin sites after challenge with LPS (two injections of 100 micrograms, i.v.). Co-injection of a single dose of cycloheximide (10 micrograms/site) with LPS (30 micrograms/site) caused a marked reduction in the amount of haemorrhage. Local cycloheximide (10 micrograms/site) administered

  13. Regulation of mitochondrial morphology by membrane potential, and DRP1-dependent division and FZO1-dependent fusion reaction in mammalian cells.

    PubMed

    Ishihara, Naotada; Jofuku, Akihiro; Eura, Yuka; Mihara, Katsuyoshi

    2003-02-21

    Mitochondria are dynamic organelles that undergo frequent fission and fusion or branching. To analyze the mitochondrial fusion reaction, mitochondria were separately labeled with green or red fluorescent protein (GFP and RFP, respectively) in HeLa cells, and the cells were fused using hemagglutinating virus of Japan (HVJ). The resulting mixing of the fluorescent reporters was then followed using fluorescence microscopy. This system revealed that mitochondria fuse frequently in mammalian cells, and the fusion depends on the membrane potential across the inner membrane. The protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), led to fragmentation of the mitochondria and inhibited the fusion reaction. Removal of CCCP recovered the fusion activity to reform filamentous mitochondrial networks. Analysis of the effects of GTP-binding proteins, DRP1 and two FZO1 isoforms, and the GTPase-domain mutants on the CCCP-induced mitochondrial morphologic changes revealed that DRP1 and FZO1 are involved in membrane budding and fusion, respectively. Furthermore, a HVJ-dependent cell fusion assay combined with RNA interference (RNAi) demonstrated that both FZO1 isoforms are essential and must be acting in cis for the mitochondrial fusion reaction to occur.

  14. Developments in inertial fusion energy and beam fusion at magnetic confinement

    NASA Astrophysics Data System (ADS)

    Hora, Heinrich

    2004-10-01

    The 70-year anniversary of the first nuclear fusion reaction of hydrogen isotopes by Oliphant, Harteck, and Rutherford is an opportunity to realize how beam fusion is the path for energy production, including both branches, the magnetic confinement fusion and the inertial fusion energy (IFE). It is intriguing that Oliphant's basic concept for igniting controlled fusion reactions by beams has made a comeback even for magnetic confinement plasma, after this beam fusion concept was revealed by the basically nonlinear processes of the well-known alternative of inertial confinement fusion using laser or particle beams. After reviewing the main streams of both directions some results are reported—as an example of possible alternatives—about how experiments with skin layer interaction and avoiding relativistic self-focusing of clean PW ps laser pulses for IFE may possibly lead to a simplified fusion reactor scheme without the need for special compression of solid deuterium tritium fuel.

  15. Cluster Productions in Intermediate-Energy Proton-Nucleus Reactions

    SciTech Connect

    Iwamoto, Hiroki; Uozumi, Yusuke

    2008-04-17

    We propose a model to describe cluster productions within the framework of the intranuclear cascade (INC) model. In our model, combination of the 'surface coalescence' and the 'knockout' is implemented to describe cluster productions in intermediate-energy nuclear reactions. In the present work, the basic ingredients of our INC model are defined and applied to nucleon and cluster productions for the proton-nucleus reactions. Although our INC model has some difficulties and room for improvement, it gives a good overall agreement with experimental data of not only nucleon productions but also cluster productions at intermediate energies.

  16. NCG gluon fusion for the Higgs production at large hadron colliders

    SciTech Connect

    Chadou, I.; Mebarki, N.; Bekli, M. R.

    2012-06-27

    A pure NCG gluon fusion contribution to the Higgs production at large hadron colliders is discussed. It is shown that the NCG results become relevant at very high energies. This can be a good signal for the space-time non commutativity events.

  17. Moderator design studies for a new neutron reference source based on the D-T fusion reaction

    NASA Astrophysics Data System (ADS)

    Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

    2016-06-01

    The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuteriumtritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2-5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

  18. Moderator design studies for a new neutron reference source based on the D–T fusion reaction

    SciTech Connect

    Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

    2016-06-01

    The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuterium-tritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14.6 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2 to 5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

  19. 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.

  20. 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.

  1. Fusion power production from TFTR plasmas fueled with deuterium and tritium*

    SciTech Connect

    Strachan, J. D.; Adler, H.; Alling, P.; Synakowski, E.

    1994-03-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 1017 m₋3 without the appearance of either disruptive MHD events or detectable changes in Alfvén wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits.

  2. Fusion power production from TFTR plasmas fueled with deuterium and tritium

    SciTech Connect

    Strachan, J. D.; Adler, H.; Alling, P.; Ancher, C.; Anderson, H.; Anderson, J. L.; Ashcroft, D.; Barnes, Cris W.; Barnes, G.; Batha, S.; Bell, M. G.; Bell, R.; Bitter, M.; Blanchard, W.; Bretz, N. L.; Budny, R.; Bush, C. E.; Camp, R.; Caorlin, M.; Cauffman, S.; Chang, Z.; Cheng, C. Z.; Collins, J.; Coward, G.; Darrow, D. S.; DeLooper, J.; Duong, H.; Dudek, L.; Durst, R.; Efthimion, P. C.; Ernst, D.; Fisher, R.; Fonck, R. J.; Fredrickson, E.; Fromm, N.; Fu, G. Y.; Furth, H. P.; Gentile, C.; Gorelenkov, N.; Grek, B.; Grisham, L. R.; Hammett, G.; Hanson, G. R.; Hawryluk, R. J.; Heidbrink, W.; Herrmann, H. W.; Hill, K. W.; Hosea, J.; Hsuan, H.; Janos, A.; Jassby, D. L.; Jobes, F. C.; Johnson, D. W.; Johnson, L. C.; Kamperschroer, J.; Kugel, H.; Lam, N. T.; LaMarche, P. H.; Loughlin, M. J.; LeBlanc, B.; Leonard, M.; Levinton, F. M.; Machuzak, J.; Mansfield, D. K.; Martin, A.; Mazzucato, E.; Majeski, R.; Marmar, E.; McChesney, J.; McCormack, B.; McCune, D. C.; McGuire, K. M.; McKee, G.; Meade, D. M.; Medley, S. S.; Mikkelsen, D. R.; Mueller, D.; Murakami, M.; Nagy, A.; Nazikian, R.; Newman, R.; Nishitani, T.; Norris, M.; O’Connor, T.; Oldaker, M.; Osakabe, M.; Owens, D. K.; Park, H.; Park, W.; Paul, S. F.; Pearson, G.; Perry, E.; Petrov, M.; Phillips, C. K.; Pitcher, S.; Ramsey, A. T.; Rasmussen, D. A.; Redi, M. H.; Roberts, D.; Rogers, J.; Rossmassler, R.; Roquemore, A. L.; Ruskov, E.; Sabbagh, S. A.; Sasao, M.; Schilling, G.; Schivell, J.; Schmidt, G. L.; Scott, S. D.; Sissingh, R.; Skinner, C. H.; Snipes, J. A.; Stevens, J.; Stevenson, T.; Stratton, B. C.; Synakowski, E.; Tang, W.; Taylor, G.; Terry, J. L.; Thompson, M. E.; Tuszewski, M.; Vannoy, C.; von Halle, A.; von Goeler, S.; Voorhees, D.; Walters, R. T.; Wieland, R.; Wilgen, J. B.; Williams, M.; Wilson, J. R.; Wong, K. L.; Wurden, G. A.; Yamada, M.; Young, K. M.; Zarnstorff, M. C.; Zweben, S. J.

    1994-05-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 1017 m ₋3 without the appearance of either disruptive magnetohydrodynamics events or detectable changes in Alfvén wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits.

  3. 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.

  4. 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.

  5. NLO QCD corrections to the jet activity in Higgs boson production via vector-boson fusion

    NASA Astrophysics Data System (ADS)

    Figy, Terrance Maynard

    Higgs production plus two jets via vector-boson fusion is expected to provide crucial information on the Higgs boson couplings at the CERN Large Hadron Collider. The achievable statistical accuracy demands comparison with next-to-leading order QCD calculations, which are presented here in the form of a fully flexible partonic Monte Carlo program. QCD corrections are determined for jet distributions and are shown to be modest, of the order of 5%--10% in most cases, but reaching 30% occasionally. Remaining scale uncertainties range from the order of 5% or less for distributions to below +/-2% for the Higgs boson cross section in typical vector-boson fusion search regions. Higgs boson production plus two jets via vector-fusion is sensitive to the tensor of the HVV (V = W, Z ) couplings, which distinguishes loop induced vertices from SM expectations. At the CERN Large Hadron Collider this information shows up in the azimuthal angle correlations of the two forward and backward quark jets which are typical for weak boson fusion. The next-to-leading order QCD corrections to this process, in the presence of anomalous HVV couplings are computed. It is shown that gluon emission does not significantly change the azimuthal jet correlations. For Higgs production via vector boson fusion (VBF), there is suppressed jet activity in the central region of rapidity. Higgs production via VBF in the association of three jets (Hjjj) is computed to NLO accuracy in QCD. K factors for Hjjj are modest, typically, 1.03 to 1.06. Scale uncertainties for the total cross section at NLO are less than 5%. 3-jet ratios for Higgs production via VBF are computed at LO and NLO. The scale dependence of 3-jet ratios is shown to be reduced at NLO.

  6. Products of the Benzene + O(3P) Reaction

    SciTech Connect

    Taatjes, Craig A.; Osborn, David L.; Selby, Talitha M.; Meloni, Giovanni; Trevitt, Adam J.; Epifanovsky, Evgeny; Krylov, Anna I.; Sirjean, Baptiste; Dames, Enoch; Wang, Hai

    2009-12-21

    The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and helium buffer in a slow-flow reactor, and reaction products were identified by using the multiplexed chemical kinetics photoionization mass spectrometer operating at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Phenol and phenoxy radical were detected and quantified. Cyclopentadiene and cyclopentadienyl radical were directly identified for the first time. Finally, ab initio calculations and master equation/RRKM modeling were used to reproduce the experimental branching ratios, yielding pressure-dependent rate expressions for the reaction channels, including phenoxy + H, phenol, cyclopentadiene + CO, which are proposed for kinetic modeling of benzene oxidation.

  7. Products of reaction of OH radicals with α-pinene

    NASA Astrophysics Data System (ADS)

    Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

    2002-07-01

    Products of the gas-phase reaction of α-pinene with OH radicals in the presence of NO have been investigated using gas chromatography with flame ionization detection to quantify pinonaldehyde and in situ atmospheric pressure ionization mass spectrometry in the negative ion mode to quantify selected other products as their NO2- adducts by utilizing C6-dihydroxycarbonyls and C6-hydroxynitrates formed in situ from the reaction of OH radicals with 1-hexene as an internal standard. The products quantified, and their molar formation yields, were: pinonaldehyde, 28 +/- 5% molecular weight 184 product (dihydroxycarbonyl), 19% (with an estimated uncertainty of a factor of ~2) molecular weight 200 product, 11% (with an estimated uncertainty of a factor of ~2). Together with a very approximate yield from our API-MS analyses for the formation of organic nitrates (~1%) and literature data for acetone (plus coproducts), ~65-70% of the reaction products and pathways are accounted for.

  8. Thermal properties of light nuclei from 12C + 12C fusion-evaporation reactions

    NASA Astrophysics Data System (ADS)

    Morelli, L.; Baiocco, G.; D'Agostino, M.; Gulminelli, F.; Bruno, M.; Abbondanno, U.; Appannababu, S.; Barlini, S.; Bini, M.; Casini, G.; Cinausero, M.; Degerlier, M.; Fabris, D.; Gelli, N.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Olmi, A.; Pasquali, G.; Piantelli, S.; Valdré, S.; Raduta, Ad R.

    2014-07-01

    The 12C + 12C reaction at 95 MeV has been studied through the complete charge identification of its products by means of the GARFIELD+RCo experimental set-up at INFN Laboratori Nazionali di Legnaro (LNL). In this paper, the first of a series of two, a comparison to a dedicated Hauser-Feshbach calculation allows selecting a set of dissipative events which corresponds, to a large extent, to the statistical evaporation of highly excited 24Mg. Information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain is also extracted. The set of data puts strong constraints on the behaviour of the level density (LD) of light nuclei above the threshold for particle emission. In particular, a fast increase of the LD parameter with excitation energy is supported by the data. Residual deviations from a statistical behaviour are seen in two specific channels, and tentatively associated with a contamination from direct reactions and/or α-clustering effects. These channels are studied in further details in the second paper of the series.

  9. Periplasmic production of native human proinsulin as a fusion to E. coli ecotin.

    PubMed

    Malik, Ajamaluddin; Jenzsch, Marco; Lübbert, Andreas; Rudolph, Rainer; Söhling, Brigitte

    2007-09-01

    Native proinsulin belongs to the class of the difficult-to-express proteins in Escherichia coli. Problems mainly arise due to its small size, a high proteolytic decay, and the necessity to form a native disulfide pattern. In the present study, human proinsulin was produced in the periplasm of E. coli as a fusion to ecotin, which is a small periplasmic protein of 16 kDa encoded by the host, containing one disulfide bond. The fusion protein was secreted to the periplasm and native proinsulin was determined by ELISA. Cultivation parameters were studied in parallel batch mode fermentations using E. coli BL21(DE3)Gold as a host. After improvement of fed-batch high density fermentation conditions, 153 mg fusion protein corresponding to 51.5mg native proinsulin was obtained per L. Proteins were extracted from the periplasm by osmotic shock treatment. The fusion protein was purified in one step by ecotin affinity chromatography on immobilized trypsinogen. After thrombin cleavage of the fusion protein, the products were separated by Ni-NTA chromatography. Proinsulin was quantified by ELISA and characterized by mass spectrometry. To evaluate the influence of periplasmic proteases, the amount of ecotin-proinsulin was determined in E. coli BL21(DE3)Gold and in a periplasmic protease deficient strain, E. coli SF120.

  10. Fusion reactions in collisions induced by Li isotopes on Sn targets

    SciTech Connect

    Fisichella, M.; Shotter, A. C.; Di Pietro, A.; Figuera, P.; Lattuada, M.; Marchetta, C.; Musumarra, A.; Pellegriti, M. G.; Ruiz, C.; Scuderi, V.; Strano, E.; Torresi, D.; Zadro, M.

    2012-10-20

    Fusion cross sections for the {sup 6}Li+{sup 120}Sn and {sup 7}Li+{sup 119}Sn systems have been measured. We aim to search for possible effects due to the different neutron transfer Q-values, by comparing the fusion cross sections for the two systems below the barrier. This experiment is the first step of a wider systematic aiming to study the above problems in collisions induced by stable and unstable Li isotopes on tin all forming the same compound nucleus.

  11. Diphoton production in gluon fusion at small transverse momentum

    NASA Astrophysics Data System (ADS)

    Nadolsky, P. M.; Schmidt, C. R.

    2003-04-01

    We discuss the production of photon pairs in gluon-gluon scattering in the context of the position-space resummation formalism at small transverse momentum. We derive the remaining unknown coefficients that arise at O(αS), as well as the remaining O(αS2) coefficient that occurs in the Sudakov factor. We comment on the impact of these coefficients on the normalization and shape of the resummed transverse momentum distribution of photon pairs, which comprise an important background to Higgs boson production at the LHC.

  12. Production and measurement of engineered surfaces for inertial confinement fusion research

    SciTech Connect

    Day, Robert D; Hatch, Douglas J; Rivera, Gerald

    2011-01-19

    Inertial Confinement Fusion uses the optical energy from a very high power laser to implode spherical capsules that contain a fuel mixture of deuterium and tritium. The capsules are made of either Beryllium, plastic, or glass and range from 0.1 mm to 2 mm in diameter. As a capsule implodes, thereby compressing the fuel to reach nuclear fusion conditions, it achieves temperatures of millions of degrees Centigrade and very high pressures. In this state, the capsule materials act like fluids and often a low density fluidic material will push on a higher density material which can be a very unstable condition depending upon the smoothness of the interface between the two materials. This unstable condition is called a hydrodynamic instabillity which results in the mixing of the two materials. If the mixing occurs between the fuel and a non-fuel material, it can stop the fusion reaction just like adding significant amounts of water to gasoline can stop the operation of an automobile. Another region in the capsule where surface roughness can cause capsule performance degradation is at a joint. For instance, many capsules are made of hemispheres that are joined together. If the joint surfaces are too rough, then there will an effective reduction in density at the joint. This density reduction can cause a non-uniform implosion which will reduce the fusion energy coming out of the capsule.

  13. Making radioactive ion beams - Detecting reaction products

    NASA Astrophysics Data System (ADS)

    Raabe, Riccardo

    2016-10-01

    We present a didactical overview of the methods for the production of radioactive ion beams (RIBs), discussing the main characteristics and associated advantages and drawbacks of the in-flight separation and isotope separation on-line methods. We include a short overview of present and planned facilities, focusing on Europe. In the second part of the paper a brief introduction on the detection of radiation is given, followed by a discussion of the specific problems related to radiation detection in measurements involving RIBs. A few illustrative examples of detection setups are presented.

  14. Description of nucleon-transfer and fusion reactions within time-dependent approaches and coupled-channel method

    SciTech Connect

    Samarin, V. V.

    2015-01-15

    The time-dependent Schrödinger equation and the method of perturbed stationary states that is based on the expansion of the total wave function for the system of two nuclear cores and a nucleon in a set of nucleon two-center functions are used to describe nucleon transfers and fusion in low-energy nuclear reactions. A set of multichannel equations that couple the relative motion of nuclei to the motion of the nucleon is obtained. The kinetic-energy coupling matrix is similar to the coupling matrix for collective excitations of nuclei.

  15. Hydrogen generation arising from the {sup 59}Ni(n,p) reaction and its impact on fission-fusion correlations

    SciTech Connect

    Greenwood, L.R.; Garner, A.F.

    1996-04-01

    Whilte the influence of transmutant helium on radiation-induced microstructural evolution has often been studied, there is a tendency to overlook the influence of concurrently-generated hydrogen. There have been some recent speculation and studies, however, that suggest that the influence of hydrogen may be enhanced in the presence of large amounts of helium, especially at lower irradiation temperatures typical of projected ITER operation. The impact of the (n,p) reaction on both hydrogen generation rates and displacement rates are evaluated in this paper for a variety of neutron spectra employed in fission-fusion correlation.

  16. Intraspecific protoplast fusion of Brettanomyces anomalus for improved production of an extracellular β-glucosidase

    PubMed Central

    Wu, Peng; Zhao, Xihong; Pan, Siyi

    2014-01-01

    Improvement of production of an extracellular β-glucosidase with high activity by Brettanomyces anomalus PSY-001 was performed by using recursive protoplast fusion in a genome-shuffling format. The initial population was generated by ultraviolet irradiation, ultrasonic mutagenesis and, then, subjected to recursive protoplast fusion. Mutant strains exhibiting significantly higher β-glucosidase activities in liquid media were isolated. The best mutant strain showed increased cell growth in a flask culture, as well as increased β-glucosidase production. A recombinant strain, F3-25, was obtained after three rounds of genome shuffling and its production of β-glucosidase activity reached 4790 U L−1, which was a nearly eightfold increase compared to the original strain B. anomalus PSY-001. The subculture experiments indicated that F3-25 was genetically stable. PMID:26019572

  17. A simulation study for radiation treatment planning based on the atomic physics of the proton-boron fusion reaction

    NASA Astrophysics Data System (ADS)

    Kim, Sunmi; Yoon, Do-Kun; Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Kyeong-Hyeon; Jang, Hong-Seok; Suh, Tae Suk

    2017-03-01

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

  18. T4-lysozyme fusion for the production of human formyl peptide receptors for structural determination.

    PubMed

    Wang, Xiaoqiang; Cui, Ying; Wang, Jiqian

    2014-03-01

    T4-lysozyme (T4L) fusion was introduced in the intracellular loop of a G protein-coupled receptor (GPCR) of human formyl peptide receptor 3 (FPR3), and the ability of T4L fusion to be used in the production of human FPR3 for structural determination was evaluated in this work. The T4L variant of human FPR3 termed FPR3-T4L was expressed in stable tetracycline-inducible HEK293 cells. A systematic detergent screening showed that fos-choline-14 was the optimal detergent to solubilize and subsequently purify FPR3-T4L from HEK293 cells. Immunoaffinity purification in combination with gel filtration was employed to purify the T4L-fused receptor to high homogeneity. The final yield of the human FPR3-T4L monomer from 2 g of cells was 0.2 mg. Circular dichroism spectroscopy indicated that the receptor adopted a correct secondary structure after purification, while ligand binding measurement indicated that the receptor was functional. Thus, the presence of T4L fusion did not evidently disturb the expression in HEK293 cells, proper folding, and functionality of human FPR3. Our study of evaluating T4L fusion for the recombinant production of human formyl peptide receptor would facilitate ongoing efforts in the structural characterization of GPCRs.

  19. Development of a Gas Stopper for Fusion-Evaporation Products

    NASA Astrophysics Data System (ADS)

    Sefcik, Jordan; Folden, Charles, III; Alfonso, Marisa

    2010-10-01

    New plans are needed in order to chemically study superheavy elements. According to a design from Michigan State University, implementing a gas stopper is the best way to do this. After being transferred through a Momentum Achromat Recoil Separator (MARS), produced ions of ^158Hf eventually reach a variable angle mylar degrader, Reaction Transfer Chamber (RTC) window, which is followed by a gas stopper of helium. Inside the gas cell is a series of electrodes, followed by a funneled ``flower petal'' design. Using the simulating program SIMION, the electrodes have electric potentials applied to each of them in order to funnel the ions into a small opening at the end of the gas stopper. Here the ions will undergo certain chemistry experiments in order to learn more about them. The hafnium ions enter the gas stopper with an energy of ˜3 MeV. However, when they reach the end of the cell, they must have an energy on the order of 0.1 eV in order perform certain chemistry experiments on them. Using an optimized set of potentials, the survival rate for the simulated ions was 96%. These results are agreeable in the sense that within error bars, there is no room for improvement in extraction efficiency. This set-up also gives desirable results for ^257Rf, which is considered a superheavy element and is thought to have the same periodicity as hafnium.

  20. Reaction and fusion cross sections for the near-symmetric system 129Xe+natSn from 8 A to 35 A MeV

    NASA Astrophysics Data System (ADS)

    Manduci, L.; Lopez, O.; Chbihi, A.; Rivet, M. F.; Bougault, R.; Frankland, J. D.; Borderie, B.; Galichet, E.; La Commara, M.; Le Neindre, N.; Lombardo, I.; Pârlog, M.; Rosato, E.; Roy, R.; Verde, G.; Vient, E.; Indra Collaboration

    2016-10-01

    Background: We study heavy-ion reactions from barrier up to Fermi energy. The data were acquired with the INDRA detector at the GANIL (Caen, France) facility. Purpose: We aim to determine the reaction and fusion cross sections for the reactions induced by 129Xe projectiles on natSn targets for incident energies ranging from 8 A to 35 A MeV. In particular, the evaluation of the fusion and incomplete fusion cross sections is the main purpose, altogether with the comparison with the systematics of Eudes et al. [Europhys. Lett. 104, 22001 (2013), 10.1209/0295-5075/104/22001]. Method: The reaction cross sections are evaluated at each beam energy with data acquired thanks to the INDRA 4 π array. The events are sorted with the help of the observable Eiso,max. We focus therefore our study on a selected sample of events, in such a way that the fusion and incomplete fusion cross sections can be estimated. Results: We present the excitation function of reaction and fusion cross sections for the heavy and nearly symmetric system 129Xe+natSn from 8 A to 35 A MeV. For the fusion excitation function the comparison with the systematics of Eudes et al. seems to be in a fair agreement starting from the beam energy 20 A MeV. For the lower beam energies (8 A and 12 A MeV) discrepancies are observed. Conclusions: The evaluated fusionlike cross sections show a good agrement with a recent systematics for beam energies greater than 20 A MeV. For low beam energies the cross-sectional values are lower than the expected ones. A probable reason for these low values is in the fusion hindrance at energies above or close to the barrier.

  1. Toxicity of aerosols of sodium reaction products.

    PubMed

    Zwicker, G M; Allen, M D; Stevens, D L

    1979-01-01

    Sodium is used as the heat transfer medium in several new energy technologies such as liquid-metal fast-breeder reactors and solar-thermal collection systems. Because sodium burns in air and reacts violently with water, the potential exists for an airborne release of sodium combustion products and subsequent human exposure. To help evaluate the potential short-term hazard from an accidental sodium fire, male juvenile or adult Wistar rats were exposed to sodium aerosols for 2 hours to determine the dose at which 50 percent of the animals were affected (ED50) for each age group. The estimated ED50 of 510 microgram/l for adults was not significantly different from the estimated ED50 of 489 microgram/l for juveniles. The incidence of acute laryngitis, attributed to exposure, was three times higher for juvenile rats than for adults, and the degree of severity of this lesion was significantly (P less than 0.05) higher for juveniles.

  2. Resummation improved rapidity spectrum for gluon fusion Higgs production

    NASA Astrophysics Data System (ADS)

    Ebert, Markus A.; Michel, Johannes K. L.; Tackmann, Frank J.

    2017-05-01

    Gluon-induced processes such as Higgs production typically exhibit large perturbative corrections. These partially arise from large virtual corrections to the gluon form factor, which at timelike momentum transfer contains Sudakov logarithms evaluated at negative arguments ln2(-1) = - π 2. It has been observed that resumming these terms in the timelike form factor leads to a much improved perturbative convergence for the total cross section. We discuss how to consistently incorporate the resummed form factor into the perturbative predictions for generic cross sections differential in the Born kinematics, including in particular the Higgs rapidity spectrum. We verify that this indeed improves the perturbative convergence, leading to smaller and more reliable perturbative uncertainties, and that this is not affected by cancellations between resummed and unresummed contributions. Combining both fixed-order and resummation uncertainties, the perturbative uncertainty for the total cross section at N3LO + N3LL φ ' is about a factor of two smaller than at N3LO. The perturbative uncertainty of the rapidity spectrum at NNLO + NNLL φ ' is similarly reduced compared to NNLO. We also study the analogous resummation for quark-induced processes, namely Higgs production through bottom quark annihilation and the Drell-Yan rapidity spectrum. For the former the resummation leads to a small improvement, while for the latter it confirms the already small uncertainties of the fixed-order predictions.

  3. First measurements of deuterium-tritium and deuterium-deuterium fusion reaction yields in ignition-scalable direct-drive implosions

    DOE PAGES

    Forrest, C. J.; Radha, P. B.; Knauer, J. P.; ...

    2017-03-03

    In this study, the deuterium-tritium (D-T) and deuterium-deuterium neutron yield ratio in cryogenic inertial confinement fusion (ICF) experiments is used to examine multifluid effects, traditionally not included in ICF modeling. This ratio has been measured for ignition-scalable direct-drive cryogenic DT implosions at the Omega Laser Facility using a high-dynamic-range neutron time-of-flight spectrometer. The experimentally inferred yield ratio is consistent with both the calculated values of the nuclear reaction rates and the measured preshot target-fuel composition. These observations indicate that the physical mechanisms that have been proposed to alter the fuel composition, such as species separation of the hydrogen isotopes, aremore » not significant during the period of peak neutron production in ignition-scalable cryogenic direct-drive DT implosions.« less

  4. Multinucleon transfer in O,1816,19F+208Pb reactions at energies near the fusion barrier

    NASA Astrophysics Data System (ADS)

    Rafferty, D. C.; Dasgupta, M.; Hinde, D. J.; Simenel, C.; Simpson, E. C.; Williams, E.; Carter, I. P.; Cook, K. J.; Luong, D. H.; McNeil, S. D.; Ramachandran, K.; Vo-Phuoc, K.; Wakhle, A.

    2016-08-01

    Background: Nuclear reactions are complex, involving collisions between composite systems where many-body dynamics determines outcomes. Successful models have been developed to explain particular reaction outcomes in distinct energy and mass regimes, but a unifying picture remains elusive. The irreversible transfer of kinetic energy from the relative motion of the collision partners to their internal states, as is known to occur in deep inelastic collisions, has yet to be successfully incorporated explicitly into fully quantal reaction models. The influence of these processes on fusion is not yet quantitatively understood. Purpose: To investigate the population of high excitation energies in transfer reactions at sub-barrier energies, which are precursors to deep inelastic processes, and their dependence on the internuclear separation. Methods: Transfer probabilities and excitation energy spectra have been measured in collisions of O,1816,19F+208Pb , at various energies below and around the fusion barrier, by detecting the backscattered projectile-like fragments in a Δ E -E telescope. Results: The relative yields of different transfer outcomes are strongly driven by Q values, but change with the internuclear separation. In 16O+208Pb , single nucleon transfer dominates, with a strong contribution from -2 p transfer close to the Coulomb barrier, though this channel becomes less significant in relation to the -2 p 2 n transfer channel at larger separations. For 18O+208Pb , the -2 p 2 n channel is the dominant charge transfer mode at all separations. In the reactions with 19F,-3 p 2 n transfer is significant close to the barrier, but falls off rapidly with energy. Multinucleon transfer processes are shown to lead to high excitation energies (up to ˜15 MeV), which is distinct from single nucleon transfer modes which predominantly populate states at low excitation energy. Conclusions: Kinetic energy is transferred into internal excitations following transfer, with this

  5. In-beam measurements of 13C+12C fusion reaction cross section at energies around and below Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Stefanescu, I.; Chilug, A.; Tudor, D.; Trache, L.; Straticiuc, M.; Burducea, I.; Focsa, I. M.; Ghita, D. G.; Zhang, N.; Tang, X.; Chen, H.

    2017-06-01

    The reaction cross section of the 12C+12C system is difficult to measure because of the presence of the resonances in the Gamow energy window. It has been proved that the 13C+12C reaction is a good alternative to study the behavior of the reaction cross section at energies relevant for astrophysics. We have measured it with activation and online techniques. During online measurements we were interested to determine the relative contributions of the open channels of the 13C+12C reaction. These determinations are necessary to evaluate the total fusion reaction cross section. Therefore, we have measured the γ-ray yields of proton, neutron and alpha particle evaporation channels from the resulting 25Mg compound nucleus using prompt γ-rays measurements. This complements the activation method. The irradiations took place at the 3 MV Tandetron Accelerator at IFIN-HH [1], Bucharest and the prompt gamma-rays were measured using a hyper-pure germanium detector with 100% relative efficiency, shielded with lead bricks. The energy range for the irradiation was from 4.6 up to 11 MeV (in laboratory frame), in steps of 0.2 MeV and the online measurements were performed from 6.4 up to 11 MeV.

  6. Distributed Bosonic States and Condensed Matter Fusion

    DTIC Science & Technology

    1990-02-01

    not further consider either Li reaction . Let us now consider whether the formation of a D + BBC can lead to the observed heat release in Pd by fusion ... fusion being dominated by interactions in which both the products and reactants obey Bose-Einstein statistics. As a result tritium release and 3He ...function. A condition for fusion is that a portion of the D atoms (and possibly other atoms and ions) that enter the electrode reside in a screened

  7. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    NASA Technical Reports Server (NTRS)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

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

    ERIC Educational Resources Information Center

    Kinsella, William J.

    1999-01-01

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

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

    ERIC Educational Resources Information Center

    Kinsella, William J.

    1999-01-01

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

  10. Investigation of cold fusion phenomena in deuterated metals. Final report, Volume 1. Overview, executive summary, chemistry, physics, gas reactions, metallurgy. Technical information series

    SciTech Connect

    Anderson, L.; Barrowes, S.C.; Bergeson, H.E.; Bourgeois, F.; Cedzynska, K.

    1991-06-01

    The March 1989 announcement by Pons and Fleischmann stimulated worldwide interest in the cold fusion phenomenon. In Utah the legislature appropriated $5 million to support cold fusion research and development. As cold fusion inquiries continue worldwide, this interim report has been written to document the scientific and legal work that has been funded by the Utah legislature. Partial contents include these titles of papers: Cold Fusion Studies in a High-Pressure Sealed Cell; Tritium and Neutron Generation in Palladium Cathodes with High Deuterium Loading; Deuterium-Gas Phase Reactions on Palladium; Excess Heat Estimation with the Kalman Filter; Ultrasonic Energy Effects on Palladium Electrodes in Cold Fusion Cells; Nuclear Measurements on Deuterium-Loaded Palladium and Titanium.

  11. Analysis of the energy transport and deposition within the reaction chamber of the prometheus inertial fusion energy reactor

    SciTech Connect

    Eggleston, J.E.; Abdou, M.A.; Tillack, M.S.

    1994-12-31

    One of the parameters affecting the feasibility of Inertial Fusion Energy (IFE) devices is the number of shots per unit time, i.e. the repetition rate. The repetition rate limits the achievable power that can be obtained from the reactor. To obtain an estimate of the allowable time between shots, a code named RECON was developed to model the response of the reaction chamber to the pellet explosion. This paper discusses how the code treats the thermodynamic response of the cavity gas and models the condensation/evaporation of this vapor to and from the first wall. A large amount of energy from the pellet microexplosion is carried by the pellet debris and the x-rays generated in the fusion reaction. Models of x-ray attenuation and ion slowing down are used to estimate the fraction of the pellet energy that is absorbed in the vapor. A large amount of energy is absorbed into the cavity gas, which causes it to become partially ionized. The ionization complicates the calculation of the temperature, pressure, and the radiative heat transfer from the gas to the first wall. To treat this problem, methods developed by Zel`dovich and Raizer are used in modeling the internal energy and the radiative heat flux. RECON was developed to run with a relatively short computational time, yet accurate enough for conceptual reactor design calculations.

  12. Some thoughts on a simple mechanism for the [sup 2]H + [sup 2]H [yields] [sup 4]He cold fusion reaction

    SciTech Connect

    Park, A.E.

    1993-11-01

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

  13. Ion cyclotron emission due to collective instability of fusion products and beam ions in TFTR and JET

    NASA Astrophysics Data System (ADS)

    Dendy, R. O.; McClements, K. G.; Lashmore-Davies, C. N.; Cottrell, G. A.; Majeski, R.; Cauffman, S.

    1995-12-01

    Ion cyclotron emission (ICE) has been observed from neutral beam heated TFTR, and JET tritium experiments at sequential cyclotron harmonics of both fusion products and beam ions. The emission originates from the outer midplane plasma, where fusion products and beam ions are likely to have a drifting ring-type velocity-space distribution that is anisotropic and sharply peaked. Fusion product driven ICE in both TFTR and JET can be attributed to the magnetoacoustic cyclotron instability, which involves the excitation of obliquely propagating waves on the fast Alfven/ion Bernstein branch at cyclotron harmonics of the fusion products. Differences between ICE observations in JET and TFTR appear to reflect the sensitivity of the instability growth rate to the ratio vbirth/cA where vbirth is the fusion product birth speed and cA is the local Alfven speed for fusion products in the outer midplane edge of TFTR supershots, vbirth < cA for alpha particles in the outer midplane edge of JET, the opposite inequality applies. If sub-Alfvenic fusion products are isotropic or have undergone even a moderate degree of thermalization, the magnetoacoustic instability cannot occur. In contrast, the super-Alfvenic alpha particles that are present in the outer midplane of JET can drive the magnetoacoustic cyclotron instability even if they are isotropic or have a relatively broad distribution of speeds. These conclusions may account for the observation that fusion product driven ICE in JET persists for longer than fusion product driven ICE in TFTR. Moreover, the time evolution of the maximum growth rate, obtained using the Sigmar model for the alpha particle distribution and TFTR data for the fusion product source rate, closely follows the observed time evolution of the ICE amplitude in TFTR supershot discharges. Other observed features of fusion product driven ICE that match the linear instability include the scaling with fusion product density, doublet splitting of spectral peaks, the

  14. Kinetics, mechanisms and products of reactions of Criegee intermediates

    NASA Astrophysics Data System (ADS)

    Orr-Ewing, Andrew

    The atmospheric ozonolysis of alkenes such as isoprene produces Criegee intermediates which are increasingly recognized as important contributors to oxidation chemistry in the Earth's troposphere. Stabilized Criegee intermediates are conveniently produced in the laboratory by ultraviolet photolysis of diiodoalkanes in the presence of O2, and can be detected by absorption spectroscopy using their strong electronic bands in the near ultraviolet region. We have used these techniques to study a wide range of reactions of Criegee intermediates, including their self-reactions, and reactions with carboxylic acids and various other trace atmospheric constituents. In collaboration with the Sandia National Laboratory group led by Drs C.A. Taatjes and D.L. Osborn, we have used photoionization and mass spectrometry methods, combined with electronic structure calculations, to characterize the products of several of these reactions. Our laboratory studies determine rate coefficients for the Criegee intermediate reactions, many of which prove to be fast. In the case of reactions with carboxylic acids, a correlation between the dipole moments of the reactants and the reaction rate coefficients suggests a dipole-capture controlled reaction and allows us to propose a structure-activity relationship to predict the rates of related processes. The contributions of these various Criegee intermediate reactions to the chemistry of the troposphere have been assessed using the STOCHEM-CRI global atmospheric chemistry model. This work was supported by NERC grant NE/K004905/1.

  15. Recent progress on MHD-induced loss of D-D fusion products in TFTR

    SciTech Connect

    Zweben, S.J.; Darrow, D.S.; Budny, R.V.; Cheng, C.Z.; Fredrickson, E.D.; Herrmann, H.; Mynick, H.E.; Schivell, J.; Chang, Z.

    1993-08-01

    This paper reviews the recent progress made toward understanding the MHD-induced loss of D-D fusion products which has been seen on TFTR since 1988. These measurements have been made using the ``lost alpha`` diagnostic, which is described briefly. The largest MHD- induced loss occurs with coherent 3/2 or 2/1 MHD activity (kink/tearing modes), which can cause up to {approx}3--5 times the first-orbit loss at I{approx}1.6--1.8 MA, roughly a {approx}20--30% global los of D-D fusion products. Modeling of these MHD-induced losses has progressed to the point where the basic loss mechanism can be accounted for qualitatively, but the experimental results can not yet be understood quantitatively. Several alpha loss codes are being developed to improve the quantitative comparison between experiment and theory.

  16. Fusion of product and process data: Batch-mode and real-time streaming

    SciTech Connect

    Vincent De Sapio; Spike Leonard

    1999-12-01

    In today's DP product realization enterprise it is imperative to reduce the design-to-fabrication cycle time and cost while improving the quality of DP parts (reducing defects). Much of this challenge resides in the inherent gap between the product and process worlds. The lack of seamless, bi-directional flow of information prevents true concurrency in the product realization world. This report addresses a framework for product-process data fusion to help achieve next generation product realization. A fundamental objective is to create an open environment for multichannel observation of process date, and subsequent mapping of that data onto product geometry. In addition to the sensor-based observation of manufacturing processes, model-based process data provides an important complement to empirically acquired data. Two basic groups of manufacturing models are process physics, and machine kinematics and dynamics. Process physics addresses analytical models that describe the physical phenomena of the process itself. Machine kinematic and dynamic models address the mechanical behavior of the processing equipment. As a secondary objective, an attempt has been made in this report to address part of the model-based realm through the development of an open object-oriented library and toolkit for machine kinematics and dynamics. Ultimately, it is desirable to integrate design definition, with all types of process data; both sensor-based and model-based. Collectively, the goal is to allow all disciplines within the product realization enterprise to have a centralized medium for the fusion of product and process data.

  17. Systematic analysis of advanced fusion fuel in inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Velarde, G.; Eliezer, S.; Henis, Z.; Piera, M.; Martinez-Val, J. M.

    1997-04-01

    Aneutronic fusion reactions can be considered as the cleanest way to exploit nuclear energy. However, these reactions present in general two main drawbacks.—very high temperatures are needed to reach relevant values of their cross sections—Moderate (and even low) energy yield per reaction. This value is still lower if measured in relation to the Z number of the reacting particles. It is already known that bremsstrahlung overruns the plasma reheating by fusion born charged-particles in most of the advanced fuels. This is for instance the case for proton-boron-11 fusion in a stoichiometric plasma and is also so in lithium isotopes fusion reactions. In this paper, the use of deuterium-tritium seeding is suggested to allow to reach higher burnup fractions of advanced fuels, starting at a lower ignition temperature. Of course, neutron production increases as DT contents does. Nevertheless, the ratio of neutron production to energy generation is much lower in DT-advanced fuel mixtures than in pure DT plasmas. One of the main findings of this work is that some natural resources (as D and Li-7) can be burned-up in a catalytic regime for tritium. In this case, neither external tritium breeding nor tritium storage are needed, because the tritium inventory after the fusion burst is the same as before it. The fusion reactor can thus operate on a pure recycling of a small tritium inventory.

  18. Theory of the compactness of the hot fusion reaction {sup 48}Ca+{sup 244}Pu{yields}{sup 292}114*

    SciTech Connect

    Gupta, Raj K.; Manhas, Monika; Muenzenberg, G.; Greiner, Walter

    2005-07-01

    Within the fragmentation theory, extended to include the orientations degrees of freedom and hexadecupole deformations, for optimized orientations, the {sup 48}Ca+{sup 244}Pu{yields}{sup 292}114* reaction is shown to be a 'compact' hot fusion reaction. The barrier is highest (hot fusion) and interaction radius smallest (compact), which occur for the collisions in the direction of the minor axis of the deformed reaction partner (i.e. for 90 deg. orientation of {sup 244}Pu). In addition to the {sup 48}Ca+{sup 244}Pu reaction valley, a number of other new reaction valleys (target-projectile combinations) are shown to arise for the 'optimally oriented hot' fusion process, the {sup 48}Ca+{sup 244}Pu being the best (lowest barrier) and {sup 54}Ti+{sup 238}U as the next possible best reaction for forming the cold compound nucleus {sup 292}114*. A similar reaction valley for {sup 48}Ca+{sup 244}Pu is found absent in the 'optimally oriented cold' fusion process.

  19. Production of a KK-graviton and a vector boson in ADD model via gluon fusion

    NASA Astrophysics Data System (ADS)

    Shivaji, Ambresh; Ravindran, V.; Agrawal, Pankaj

    2012-02-01

    In the models with large extra-dimensions, we examine the production of a vector boson (γ/ Z) in association with the Kaluza-Klein (KK) modes of the graviton via gluon fusion. At the leading order, the process takes place through quark-loop box and triangle diagrams and it is ultraviolate finite. We report the results for the LHC. We also discuss the issues of anomaly and decoupling of heavy quarks in the amplitude.

  20. Design of a new in-flight separator for heavy and superheavy fusion and transfer products

    NASA Astrophysics Data System (ADS)

    Heinz, S.; Barth, W.; Franczak, B.; Geissel, H.; Gupta, M.; Hofmann, S.; Mickat, S.; Münzenberg, G.; Plaß, W. R.; Scheidenberger, C.; Weick, H.; Winkler, M.

    2013-12-01

    We are developing a new velocity filter which is foreseen for separation of fusion and deep inelastic transfer products in the region of heavy and superheavy nuclei. The device is developed in collaboration with GSI Darmstadt, the University of Giessen and the Manipal University, India. In parallel to the separator design we are developing new techniques for particle detection and identification, especially for heavy nuclei which are not accessible with the presently available techniques.

  1. Thermal and structural design aspects of high-temperature blankets for fusion synfuel production

    SciTech Connect

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

    1981-01-01

    The most promising process, high temperature electrolysis (HTE) of steam at temperatures of greater than or equal to 1000/sup 0/C is examined. In HTE, a large fraction (up to approx. 50%) of the energy input to split water to hydrogen and oxygen comes from thermal energy. For the projected operating conditions achieved by high temperature fusion blankets, overall efficiencies for hydrogen production should be on the order of 60%. The design, thermal-hydraulics, and materials for such blankets are discussed.

  2. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  3. 40 CFR 721.10058 - Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction product of alkylphenol... Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and formaldehyde... identified generically as reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl...

  4. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  5. 40 CFR 721.10058 - Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of alkylphenol... Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and formaldehyde... identified generically as reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl...

  6. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  7. 40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ester, reaction products with substituted alkylamine (generic). 721.10448 Section 721.10448 Protection... Acetic acid, hydroxy- methoxy-, methyl ester, reaction products with substituted alkylamine (generic). (a... generically as acetic acid, hydroxymethoxy-, methyl ester, reaction products with substituted alkylamine...

  8. 40 CFR 721.10058 - Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of alkylphenol... Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and formaldehyde... identified generically as reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl...

  9. 40 CFR 721.10058 - Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction product of alkylphenol... Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and formaldehyde... identified generically as reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl...

  10. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721.10679 Section 721... Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester... identified generically as carboxylic acid, substituted alkylstannylene ester, reaction products...

  11. 40 CFR 721.10448 - Acetic acid, hydroxy- methoxy-, methylester, reaction products with substituted alkylamine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-, methylester, reaction products with substituted alkylamine (generic). 721.10448 Section 721.10448 Protection... Acetic acid, hydroxy- methoxy-, methylester, reaction products with substituted alkylamine (generic). (a... generically as acetic acid, hydroxymethoxy-, methyl ester, reaction products with substituted alkylamine...

  12. 40 CFR 721.10058 - Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of alkylphenol... Reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl dibenzene, and formaldehyde... identified generically as reaction product of alkylphenol, aromatic cyclicamine, alkyl diglycidyl...

  13. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  14. 40 CFR 721.10059 - Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of alkylphenyl... Reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and alkyl diglycidyl dibenzene... identified generically as reaction product of alkylphenyl glycidyl ether, polyalkylenepolyamine, and...

  15. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T [perpendicular] [ne] T[parallel]and with appreciable drift velocity along the confining magnetic field. Single dressed'' test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between kinetic or causal instabilities'' and hydrodynamic instabilities'' are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k[parallel] = 0 for k[parallel] [ne] 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an inverted'' population of states.

  16. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T {perpendicular} {ne} T{parallel}and with appreciable drift velocity along the confining magnetic field. Single ``dressed`` test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between ``kinetic or causal instabilities`` and ``hydrodynamic instabilities`` are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k{parallel} = 0 for k{parallel} {ne} 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an ``inverted`` population of states.

  17. Electroweak and QCD corrections to Higgs production via vector-boson fusion at the CERN LHC

    SciTech Connect

    Ciccolini, M.; Denner, A.; Dittmaier, S.

    2008-01-01

    The radiative corrections of the strong and electroweak interactions are calculated at next-to-leading order for Higgs-boson production in the weak-boson-fusion channel at hadron colliders. Specifically, the calculation includes all weak-boson fusion and quark-antiquark annihilation diagrams to Higgs-boson production in association with two hard jets, including all corresponding interferences. The results on the QCD corrections confirm that previously made approximations of neglecting s-channel diagrams and interferences are well suited for predictions of Higgs production with dedicated vector-boson fusion cuts at the LHC. The electroweak corrections, which also include real corrections from incoming photons and leading heavy Higgs-boson effects at two-loop order, are of the same size as the QCD corrections, viz. typically at the level of 5%-10% for a Higgs-boson mass up to {approx}700 GeV. In general, both types of corrections do not simply rescale differential distributions, but induce distortions at the level of 10%. The discussed corrections have been implemented in a flexible Monte Carlo event generator.

  18. Adjoint Monte Carlo simulation of fusion product activation probe experiment in ASDEX Upgrade tokamak

    NASA Astrophysics Data System (ADS)

    Äkäslompolo, S.; Bonheure, G.; Tardini, G.; Kurki-Suonio, T.; The ASDEX Upgrade Team

    2015-10-01

    The activation probe is a robust tool to measure flux of fusion products from a magnetically confined plasma. A carefully chosen solid sample is exposed to the flux, and the impinging ions transmute the material making it radioactive. Ultra-low level gamma-ray spectroscopy is used post mortem to measure the activity and, thus, the number of fusion products. This contribution presents the numerical analysis of the first measurement in the ASDEX Upgrade tokamak, which was also the first experiment to measure a single discharge. The ASCOT suite of codes was used to perform adjoint/reverse Monte Carlo calculations of the fusion products. The analysis facilitates, for the first time, a comparison of numerical and experimental values for absolutely calibrated flux. The results agree to within a factor of about two, which can be considered a quite good result considering the fact that all features of the plasma cannot be accounted in the simulations.Also an alternative to the present probe orientation was studied. The results suggest that a better optimized orientation could measure the flux from a significantly larger part of the plasma. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  19. Alternate applications of fusion power: development of a high-temperature blanket for synthetic-fuel production

    SciTech Connect

    Howard, P.A.; Mattas, R.F.; Krajcinovic, D.; DePaz, J.; Gohar, Y.

    1981-11-01

    This study has shown that utilization of the unique features of a fusion reactor can result in a novel and potentially economical method of decomposing steam into hydrogen and oxygen. Most of the power of fusion reactors is in the form of energetic neutrons. If this power could be used to produce high temperature uncontaminated steam, a large fraction of the energy needed to decomposee the steam could be supplied as thermal energy by the fusion reaction. Proposed high temperature electrolysis processes require steam temperature in excess of 1000/sup 0/C for high efficiency. The design put forth in this study details a system that can accomplish that end.

  20. Probing dynamics of fusion reactions through cross-section and spin distribution measurement

    NASA Astrophysics Data System (ADS)

    Kaur, Maninder; Behera, B. R.; Singh, Gulzar; Singh, Varinderjit; Madhavan, N.; Muralithar, S.; Nath, S.; Gehlot, J.; Mohanto, G.; Mukul, Ish; Siwal, D.; Thakur, M.; Kapoor, K.; Sharma, P.; Banerjee, T.; Jhingan, A.; Varughese, T.; Bala, Indu; Nayak, B. K.; Saxena, A.; Chatterjee, M. B.; Stevenson, P. D.

    2016-05-01

    Present work aims to explicate the effect of entrance channel mass asymmetry on fusion dynamics for the Compound Nucleus 80Sr populated through two different channels, 16O+64Zn and 32S+48Ti, using cross-section and spin distribution measurements as probes. The evaporation spectra studies for these systems, reported earlier indicate the presence of dynamical effects for mass symmetric 32S+48Ti system.The CCDEF and TDHF calculations have been performed for both the systems and an attempt has been made to explain the reported deviations in the α-particle spectrum for the mass symmetric system.

  1. 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.

  2. Population of isomeric states in fusion and transfer reactions in beams of loosely bound nuclei near the Coulomb barrier

    SciTech Connect

    Skobelev, N. K.

    2015-07-15

    The influence of the mechanisms of nuclear reactions on the population of {sup 195m}Hg and {sup 197m}Hg(7/2{sup −}), {sup 198m}Tl and {sup 196m}Tl(7{sup +}), and {sup 196m}Au and {sub 198m}Au(12{sup −}) isomeric nuclear states obtained in reactions induced by beams of {sup 3}He, {sup 6}Li, and {sup 6}He weakly bound nuclei is studied. The behavior of excitation functions and high values of isomeric ratios (δ{sub m}/δ{sub g}) for products of nuclear reactions proceeding through a compound nucleus and involving neutron evaporation are explained within statistical models. Reactions in which the emission of charged particles occurs have various isomeric ratios depending on the reaction type. The isomeric ratio is lower in direct transfer reactions involving charged-particle emission than in reactions where the evaporation of charged particles occurs. Reactions accompanied by neutron transfer usually have a lower isomeric ratio, which behaves differently for different direct-reaction types (stripping versus pickup reactions)

  3. Using multiple secondary fusion products to evaluate fuel ρR, electron temperature, and mix in deuterium-filled implosions at the NIF

    SciTech Connect

    Rinderknecht, H. G. Rosenberg, M. J.; Zylstra, A. B.; Lahmann, B.; Séguin, F. H.; Frenje, J. A.; Li, C. K.; Gatu Johnson, M.; Petrasso, R. D.; Berzak Hopkins, L. F.; Caggiano, J. A.; Divol, L.; Hartouni, E. P.; Hatarik, R.; Hatchett, S. P.; Le Pape, S.; Mackinnon, A. J.; McNaney, J. M.; Meezan, N. B.; Moran, M. J.; and others

    2015-08-15

    In deuterium-filled inertial confinement fusion implosions, the secondary fusion processes D({sup 3}He,p){sup 4}He and D(T,n){sup 4}He occur, as the primary fusion products {sup 3}He and T react in flight with thermal deuterons. In implosions with moderate fuel areal density (∼5–100 mg/cm{sup 2}), the secondary D-{sup 3}He reaction saturates, while the D-T reaction does not, and the combined information from these secondary products is used to constrain both the areal density and either the plasma electron temperature or changes in the composition due to mix of shell material into the fuel. The underlying theory of this technique is developed and applied to three classes of implosions on the National Ignition Facility: direct-drive exploding pushers, indirect-drive 1-shock and 2-shock implosions, and polar direct-drive implosions. In the 1- and 2-shock implosions, the electron temperature is inferred to be 0.65 times and 0.33 times the burn-averaged ion temperature, respectively. The inferred mixed mass in the polar direct-drive implosions is in agreement with measurements using alternative techniques.

  4. Using multiple secondary fusion products to evaluate fuel ρR, electron temperature, and mix in deuterium-filled implosions at the NIF

    NASA Astrophysics Data System (ADS)

    Rinderknecht, H. G.; Rosenberg, M. J.; Zylstra, A. B.; Lahmann, B.; Séguin, F. H.; Frenje, J. A.; Li, C. K.; Gatu Johnson, M.; Petrasso, R. D.; Berzak Hopkins, L. F.; Caggiano, J. A.; Divol, L.; Hartouni, E. P.; Hatarik, R.; Hatchett, S. P.; Le Pape, S.; Mackinnon, A. J.; McNaney, J. M.; Meezan, N. B.; Moran, M. J.; Bradley, P. A.; Kline, J. L.; Krasheninnikova, N. S.; Kyrala, G. A.; Murphy, T. J.; Schmitt, M. J.; Tregillis, I. L.; Batha, S. H.; Knauer, J. P.; Kilkenny, J. D.

    2015-08-01

    In deuterium-filled inertial confinement fusion implosions, the secondary fusion processes D(3He,p)4He and D(T,n)4He occur, as the primary fusion products 3He and T react in flight with thermal deuterons. In implosions with moderate fuel areal density (˜5-100 mg/cm2), the secondary D-3He reaction saturates, while the D-T reaction does not, and the combined information from these secondary products is used to constrain both the areal density and either the plasma electron temperature or changes in the composition due to mix of shell material into the fuel. The underlying theory of this technique is developed and applied to three classes of implosions on the National Ignition Facility: direct-drive exploding pushers, indirect-drive 1-shock and 2-shock implosions, and polar direct-drive implosions. In the 1- and 2-shock implosions, the electron temperature is inferred to be 0.65 times and 0.33 times the burn-averaged ion temperature, respectively. The inferred mixed mass in the polar direct-drive implosions is in agreement with measurements using alternative techniques.

  5. Using multiple secondary fusion products to evaluate fuel ρR, electron temperature, and mix in deuterium-filled implosions at the NIF

    SciTech Connect

    Rinderknecht, H. G.; Rosenberg, M. J.; Zylstra, A. B.; Lahmann, B.; Séguin, F. H.; Frenje, J. A.; Li, C. K.; Gatu Johnson, M.; Petrasso, R. D.; Berzak Hopkins, L. F.; Caggiano, J. A.; Divol, L.; Hartouni, E. P.; Hatarik, R.; Hatchett, S. P.; Le Pape, S.; Mackinnon, A. J.; McNaney, J. M.; Meezan, N. B.; Moran, M. J.; Bradley, P. A.; Kline, J. L.; Krasheninnikova, N. S.; Kyrala, G. A.; Murphy, T. J.; Schmitt, M. J.; Tregillis, I. L.; Batha, S. H.; Knauer, J. P.; Kilkenny, J. D.

    2015-08-25

    In deuterium-filled inertial confinement fusion implosions, the secondary fusion processes D(3He,p)4He and D(T,n)4He occur, as the primary fusion products 3He and T react in flight with thermal deuterons. In implosions with moderate fuel areal density (~ 5–100 mg/cm2), the secondary D-3He reaction saturates, while the D-T reaction does not, and the combined information from these secondary products is used to constrain both the areal density and either the plasma electron temperature or changes in the composition due to mix of shell material into the fuel. The underlying theory of this technique is developed and applied to three classes of implosions on the National Ignition Facility: direct-drive exploding pushers, indirect-drive 1-shock and 2-shock implosions,and polar direct-drive implosions. In the 1- and 2-shock implosions, the electron temperature is inferred to be 0.65 x and 0.33 x the burn-averaged ion temperature, respectively. The inferred mixed mass in the polar direct-drive implosions is in agreement with measurements using alternative techniques.

  6. Using multiple secondary fusion products to evaluate fuel ρR, electron temperature, and mix in deuterium-filled implosions at the NIF

    DOE PAGES

    Rinderknecht, H. G.; Rosenberg, M. J.; Zylstra, A. B.; ...

    2015-08-25

    In deuterium-filled inertial confinement fusion implosions, the secondary fusion processes D(3He,p)4He and D(T,n)4He occur, as the primary fusion products 3He and T react in flight with thermal deuterons. In implosions with moderate fuel areal density (~ 5–100 mg/cm2), the secondary D-3He reaction saturates, while the D-T reaction does not, and the combined information from these secondary products is used to constrain both the areal density and either the plasma electron temperature or changes in the composition due to mix of shell material into the fuel. The underlying theory of this technique is developed and applied to three classes of implosionsmore » on the National Ignition Facility: direct-drive exploding pushers, indirect-drive 1-shock and 2-shock implosions,and polar direct-drive implosions. In the 1- and 2-shock implosions, the electron temperature is inferred to be 0.65 x and 0.33 x the burn-averaged ion temperature, respectively. The inferred mixed mass in the polar direct-drive implosions is in agreement with measurements using alternative techniques.« less

  7. Doc2b promotes GLUT4 exocytosis by activating the SNARE-mediated fusion reaction in a calcium- and membrane bending–dependent manner

    PubMed Central

    Yu, Haijia; Rathore, Shailendra S.; Davis, Eric M.; Ouyang, Yan; Shen, Jingshi

    2013-01-01

    The glucose transporter GLUT4 plays a central role in maintaining body glucose homeostasis. On insulin stimulation, GLUT4-containing vesicles fuse with the plasma membrane, relocating GLUT4 from intracellular reservoirs to the cell surface to uptake excess blood glucose. The GLUT4 vesicle fusion reaction requires soluble N-ethylmaleimide–sensitive factor attachment protein receptors (SNAREs) as the core fusion engine and a group of regulatory proteins. In particular, the soluble C2-domain factor Doc2b plays a key role in GLUT4 vesicle fusion, but its molecular mechanism has been unclear. Here we reconstituted the SNARE-dependent GLUT4 vesicle fusion in a defined proteoliposome fusion system. We observed that Doc2b binds to GLUT4 exocytic SNAREs and potently accelerates the fusion kinetics in the presence of Ca2+. The stimulatory activity of Doc2b requires intact Ca2+-binding sites on both the C2A and C2B domains. Using electron microscopy, we observed that Doc2b strongly bends the membrane bilayer, and this membrane-bending activity is essential to the stimulatory function of Doc2b in fusion. These results demonstrate that Doc2b promotes GLUT4 exocytosis by accelerating the SNARE-dependent fusion reaction by a Ca2+- and membrane bending–dependent mechanism. Of importance, certain features of Doc2b function appear to be distinct from how synaptotagmin-1 promotes synaptic neurotransmitter release, suggesting that exocytic Ca2+ sensors may possess divergent mechanisms in regulating vesicle fusion. PMID:23427263

  8. Doc2b promotes GLUT4 exocytosis by activating the SNARE-mediated fusion reaction in a calcium- and membrane bending-dependent manner.

    PubMed

    Yu, Haijia; Rathore, Shailendra S; Davis, Eric M; Ouyang, Yan; Shen, Jingshi

    2013-04-01

    The glucose transporter GLUT4 plays a central role in maintaining body glucose homeostasis. On insulin stimulation, GLUT4-containing vesicles fuse with the plasma membrane, relocating GLUT4 from intracellular reservoirs to the cell surface to uptake excess blood glucose. The GLUT4 vesicle fusion reaction requires soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) as the core fusion engine and a group of regulatory proteins. In particular, the soluble C2-domain factor Doc2b plays a key role in GLUT4 vesicle fusion, but its molecular mechanism has been unclear. Here we reconstituted the SNARE-dependent GLUT4 vesicle fusion in a defined proteoliposome fusion system. We observed that Doc2b binds to GLUT4 exocytic SNAREs and potently accelerates the fusion kinetics in the presence of Ca(2+). The stimulatory activity of Doc2b requires intact Ca(2+)-binding sites on both the C2A and C2B domains. Using electron microscopy, we observed that Doc2b strongly bends the membrane bilayer, and this membrane-bending activity is essential to the stimulatory function of Doc2b in fusion. These results demonstrate that Doc2b promotes GLUT4 exocytosis by accelerating the SNARE-dependent fusion reaction by a Ca(2+)- and membrane bending-dependent mechanism. Of importance, certain features of Doc2b function appear to be distinct from how synaptotagmin-1 promotes synaptic neurotransmitter release, suggesting that exocytic Ca(2+) sensors may possess divergent mechanisms in regulating vesicle fusion.

  9. Phenomenological analysis of Higgs boson production through gluon fusion in association with jets

    DOE PAGES

    Greiner, Nicolas; Hoeche, Stefan; Luisoni, Gionata; ...

    2016-01-27

    In this study, we present a detailed phenomenological analysis of the production of a Standard Model Higgs boson in association with up to three jets. We consider the gluon fusion channel using an effective theory in the large top-quark mass limit. Higgs boson production in gluon fusion constitutes an irreducible background to the vector boson fusion (VBF) process; hence the precise knowledge of its characteristics is a prerequisite for any measurement in the VBF channel. The calculation is carried out at next-to-leading order (NLO) in QCD in a fully automated way by combining the two programs GoSam and Sherpa. Wemore » present numerical results for a large variety of observables for both standard cuts and VBF selection cuts. We find that for all jet multiplicities the NLO corrections are sizeable. This is particularly true in the presence of kinematic selections enhancing the VBF topology, which are based on vetoing additional jet activity. In this case, precise predictions for the background can be made using our calculation by taking the difference between the inclusive H+2 jets and the inclusive H+3 jets result.« less

  10. Functional expression and purification of recombinant Hepcidin25 production in Escherichia coli using SUMO fusion technology.

    PubMed

    Sadr, Vahideh; Saffar, Behnaz; Emamzadeh, Rahman

    2017-04-30

    Hepcidin25 is a small cysteine-rich peptide hormone known as a new class of antimicrobial peptides. The purpose of the present study was to express, purify and investigate the antibacterial properties of recombinant human hepcidin25 protein production in Escherichia coli. Human hepcidin25 gene was optimized and fused to a small ubiquitin-related modifier (SUMO) gene for higher expression. Then SUMO-hepcidin25 was cloned into the pET-32a (+) vector and expressed in E. coli Origami. The fusion protein with a molecular weight of approximately 35kDa was analyzed on SDS-PAGE gel. The highest expression was observed after 6h induction and the fusion protein consisted approximately 47% of the total cellular protein. The purified SUMO-hepcidin25 purity was determined to be higher than 95%, with a final yield of 3.9mgl(-)(1) of media. The recombinant hepcidin25 showed antibacterial activity against both Gram negative (Klebsiella pneumonia) and Gram positive (Staphylococcus aureus and Bacillus cereus) bacteria with minimum inhibitory concentrations (MICs) of 150μgml(-1), 18.7μg/ml(-1) and 37.5μg/ml(-1), respectively. These results indicated that thioredoxin and SUMO dual fusion system is an efficient production system for synthesis functional human hepcidin25. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Phenomenological analysis of Higgs boson production through gluon fusion in association with jets

    SciTech Connect

    Greiner, Nicolas; Hoeche, Stefan; Luisoni, Gionata; Schonherr, Marek; Winter, Jan -Christopher; Yundin, Valery

    2016-01-27

    In this study, we present a detailed phenomenological analysis of the production of a Standard Model Higgs boson in association with up to three jets. We consider the gluon fusion channel using an effective theory in the large top-quark mass limit. Higgs boson production in gluon fusion constitutes an irreducible background to the vector boson fusion (VBF) process; hence the precise knowledge of its characteristics is a prerequisite for any measurement in the VBF channel. The calculation is carried out at next-to-leading order (NLO) in QCD in a fully automated way by combining the two programs GoSam and Sherpa. We present numerical results for a large variety of observables for both standard cuts and VBF selection cuts. We find that for all jet multiplicities the NLO corrections are sizeable. This is particularly true in the presence of kinematic selections enhancing the VBF topology, which are based on vetoing additional jet activity. In this case, precise predictions for the background can be made using our calculation by taking the difference between the inclusive H+2 jets and the inclusive H+3 jets result.

  12. Measurement of tritium production rate distribution for a fusion-fission hybrid conceptual reactor

    NASA Astrophysics Data System (ADS)

    Wang, Xin-Hua; Guo, Hai-Ping; Mou, Yun-Feng; Zheng, Pu; Liu, Rong; Yang, Xiao-Fei; Yang, Jian

    2013-05-01

    A fusion-fission hybrid conceptual reactor is established. It consists of a DT neutron source and a spherical shell of depleted uranium and hydrogen lithium. The tritium production rate (TPR) distribution in the conceptual reactor was measured by DT neutrons using two sets of lithium glass detectors with different thicknesses in the hole in the vertical direction with respect to the D+ beam of the Cockcroft-Walton neutron generator in direct current mode. The measured TPR distribution is compared with the calculated results obtained by the three-dimensional Monte Carlo code MCNP5 and the ENDF/B-VI data file. The discrepancy between the measured and calculated values can be attributed to the neutron data library of the hydrogen lithium lack S(α, β) thermal scattering model, so we show that a special database of low-energy and thermal neutrons should be established in the physics design of fusion-fission hybrid reactors.

  13. Dynamical Dipole mode in the 40,48 Ca +152,144Sm fusion reactions at 11 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Parascandolo, C.; Pierroutsakou, D.; Alba, R.; Del Zoppo, A.; Maiolino, C.; Santonocito, D.; Agodi, C.; Baran, V.; Boiano, A.; Colonna, M.; Coniglione, R.; De Filippo, E.; Di Toro, M.; Emanuele, U.; Farinon, F.; Guglielmetti, A.; La Commara, M.; Martin, B.; Mazzocchi, C.; Mazzocco, M.; Rizzo, C.; Romoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Torresi, D.; Trifirò, A.; Trimarchi, M.

    2016-05-01

    The excitation of the dynamical dipole mode along the fusion path was investigated in the formation of a heavy compound nucleus in the A=190 mass region. To form the compound nucleus, the 40Ca + 152Sm and 48Ca + 144Sm reactions were employed at Elab=11 and 10.1 MeV/nucleon, respectively. Both fusion-evaporation and fission events were studied simultaneously for the first time. Our results for evaporation and fission events (preliminary) show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously.

  14. Study of the 20,22Ne+20,22Ne and 10,12,13,14,15C+12C Fusion Reactions with MUSIC

    NASA Astrophysics Data System (ADS)

    Avila, M. L.; Rehm, K. E.; Almaraz-Calderon, S.; Carnelli, P. F. F.; DiGiovine, B.; Esbensen, H.; Hoffman, C. R.; Jiang, C. L.; Kay, B. P.; Lai, J.; Nusair, O.; Pardo, R. C.; Santiago-Gonzalez, D.; Talwar, R.; Ugalde, C.

    2016-05-01

    A highly efficient MUlti-Sampling Ionization Chamber (MUSIC) detector has been developed for measurements of fusion reactions. A study of fusion cross sections in the 10,12,13,14,15C+12C and 20,22Ne+20,22Ne systems has been performed at ATLAS. Experimental results and comparison with theoretical predictions are presented. Furthermore, results of direct measurements of the 17O(α, n)20Ne, 23Ne(α, p)26Mg and 23Ne(α, n)26Al reactions will be discussed.

  15. Acid-catalyzed reactions of hexanal on sulfuric acid particles: Identification of reaction products

    NASA Astrophysics Data System (ADS)

    Garland, Rebecca M.; Elrod, Matthew J.; Kincaid, Kristi; Beaver, Melinda R.; Jimenez, Jose L.; Tolbert, Margaret A.

    While it is well established that organics compose a large fraction of the atmospheric aerosol mass, the mechanisms through which organics are incorporated into atmospheric aerosols are not well understood. Acid-catalyzed reactions of compounds with carbonyl groups have recently been suggested as important pathways for transfer of volatile organics into acidic aerosols. In the present study, we use the aerodyne aerosol mass spectrometer (AMS) to probe the uptake of gas-phase hexanal into ammonium sulfate and sulfuric acid aerosols. While both deliquesced and dry non-acidic ammonium sulfate aerosols showed no organic uptake, the acidic aerosols took up substantial amounts of organic material when exposed to hexanal vapor. Further, we used 1H-NMR, Fourier transform infrared (FTIR) spectroscopy and GC-MS to identify the products of the acid-catalyzed reaction of hexanal in acidic aerosols. Both aldol condensation and hemiacetal products were identified, with the dominant reaction products dependent upon the initial acid concentration of the aerosol. The aldol condensation product was formed only at initial concentrations of 75-96 wt% sulfuric acid in water. The hemiacetal was produced at all sulfuric acid concentrations studied, 30-96 wt% sulfuric acid in water. Aerosols up to 88.4 wt% organic/11.1 wt% H 2SO 4/0.5 wt% water were produced via these two dimerization reaction pathways. The UV-VIS spectrum of the isolated aldol condensation product, 2-butyl 2-octenal, extends into the visible region, suggesting these reactions may impact aerosol optical properties as well as aerosol composition. In contrast to previous suggestions, no polymerization of hexanal or its products was observed at any sulfuric acid concentration studied, from 30 to 96 wt% in water.

  16. Comparison of complementary reactions for the production of {sup 261,262}Bh

    SciTech Connect

    Nelson, S. L.; Folden III, C. M.; Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nitsche, H.; Gregorich, K. E.; Sudowe, R.; Duellmann, Ch. E.; Eichler, R.

    2008-08-15

    Two heavy-ion induced fusion reactions producing {sup 261,262}Bh were studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. An excitation function for the production of {sup 262}Bh via the reaction {sup 209}Bi({sup 54}Cr,n){sup 262}Bh was measured with a maximum cross section from a fit to the data of 430 {+-} 110 pb observed at a compound nucleus excitation energy of 15.7 MeV. New data have been measured for the 1n exit channel of the {sup 208}Pb({sup 55}Mn, n){sup 262}Bh reaction. We present an updated excitation function with an observed maximum cross section of 530{+-}100 pb at a compound nucleus excitation energy of 14.1 MeV. Events corresponding to the 2n exit channel for the {sup 209}Bi({sup 54}Cr,2n){sup 261}Bh and {sup 208}Pb({sup 55}Mn,2n){sup 261}Bh reactions were also observed and are presented as partial excitation functions. The measured decay properties correspond well with existing experimental data. We compare these experimental results to cross section predictions from a model by Swiatecki et al. and discuss entrance channel effects on the magnitude of 1n cross sections.

  17. Isospin Dependence of Incomplete Fusion Reactions at 25 MeV/Nucleon

    SciTech Connect

    Amorini, F.; Agodi, C.; Alba, R.; Anzalone, A.; Coniglione, R.; Di Pietro, A.; Figuera, P.; Maiolino, C.; Santonocito, D.; Sapienza, P.; Cardella, G.; Papa, M.; De Filippo, E.; Pagano, A.; Pirrone, S.; Verde, G.; Giuliani, G.; Berceanu, I.; Pop, A.; Cavallaro, S.

    2009-03-20

    {sup 40}Ca+{sup 40,48}Ca,{sup 46}Ti reactions at 25 MeV/nucleon have been studied using the 4{pi} CHIMERA detector. An isospin effect on the competition between fusionlike and binarylike reaction mechanisms has been observed. The probability of producing a heavy residue is lower in the case of N{approx_equal}Z colliding systems as compared to the case of reactions induced on the neutron rich {sup 48}Ca target. Predictions based on constrained molecular dynamics II calculations show that the competition between fusionlike and binary reactions in the selected centrality bins can constrain the parametrization of the symmetry energy and its density dependence in the nuclear equation of state.

  18. Effects of level density parameter on the superheavy production in cold fusion

    NASA Astrophysics Data System (ADS)

    Pahlavani, M. R.; Alavi, S. A.

    2014-12-01

    By using semiclassical method and considering Woods-Saxon and Coulomb potentials, the level density parameter a was calculated for three superheavy nuclei 270110, 278112 and 290116. Obtained results showed that the value of level density parameter of these nuclei is near to the simple relation a ≈ A/10. In framework of the dinuclear system model, the effects of level density parameter on the probability of the formation of a compound nucleus, the ratio of neutron emission width and fission width, and evaporation residue cross-section of three cold fusion reactions 62Ni+208Pb, 70Zn+208Pb and 82Se+208Pb, leading to superheavy elements were investigated. The findings indicate that the level density parameter play a significant role in calculations of heavy-ion fusion-fission reactions. The obtained results in the case of a = A/12 have larger values in comparison with calculated level density parameter with Woods-Saxon potential (aWS) and a = A/10. The theoretical results of the evaporation residue cross-section are very sensitive to the choice of level density parameter. The calculated values with aWS are in good agreement with experimental values.

  19. Detection of an unknown fusion protein in confiscated black market products.

    PubMed

    Walpurgis, Katja; Krug, Oliver; Thomas, Andreas; Laussmann, Tim; Schänzer, Wilhelm; Thevis, Mario

    2014-01-01

    Even without clinical approval, many performance-enhancing drugs are available on the black market and can therefore be easily obtained by cheating athletes. The misuse of these preparations can be associated with unforeseeable health risks - either due to a poor quality of the drugs or as a result of an insufficient clinical assessment. Moreover, confiscated black market products have frequently been shown to contain ingredients other than those declared on the label as well as additional by-products or compounds with a modified molecular structure. This communication describes the identification of an unknown fusion protein observed in several unlabelled black market products obtained from independent sources. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of the confiscated preparations indicated the presence of an 18-kDa fusion protein consisting of the bacterial redox protein thioredoxin-1 (Trx, 12 kDa) and a 6-kDa peptide of unassigned composition. Trx has no relevance as performance enhancing agent but is routinely used as solubility tag for recombinant protein production. Further evaluation of the acquired MS/MS data revealed both an additional His tag and a thrombin cleavage site between the tags and the presumed bioactive peptide. However, thrombin cleavage of the fusion protein and LC-MS/MS analysis of the resulting peptide fragment finally suggested that the unknown protein is only the product of an empty expression vector without the DNA insert of interest. These findings are a further alarming example for the high level of risk that athletes take when misusing drugs obtained from the black market.

  20. Increased D-D Fusion Reaction Boosted by Electron Screening at the Inner Shell of Metal Atoms

    NASA Astrophysics Data System (ADS)

    Luo, Nie; Miley, George

    2004-10-01

    Recent experiments indicate an abnormally high electron screening effect on the D-D fusion cross-section during low energy (< 10 keV) bombardment of select deuterated metals [1]. The authors attribute this effect to a contribution from core electrons ignored in normal screening calculations [2]. This research studies the contribution of the atomic potential distribution on the classical dynamics of keV deuterons in a host metal, taken here as Pd. A standard atomic code is used to obtain the atomic electron charge density and the potential profile in the metal atom. Using these results, the deuterons are found to spend most of their penetration time near the Pd M shell. This effect drastically increases the probability of a rendezvous between two deuterons in a rather confined area roughly 0.1 angstrom from the Pd nucleus. This mechanism, combined with the increased tunneling rate due to screening from the high electron density at M-shell, enhances the low energy D-D fusion cross-section for metal hydrides. Results from these calculations and comparisons with experimental data will be presented. [1] F. Strieder, C. Rolfs, C. Spitaleri, and P.Corvisiero, Naturwissenschaften, 88 (2001) 461. [2] G. H. Miley, H. Hora, N. Luo, ¡°Screening in Low Energy Nuclear Reactions of Importance to Nuclear Astrophysics¡±, APS April Mtg. (2004), Denver, CO.

  1. Investigation of the impact of the nonlinear relations among soil moisture products over data fusion process

    NASA Astrophysics Data System (ADS)

    Hesami Afshar, Mahdi; Bulut, Burak; Tugrul Yilmaz, M.

    2017-04-01

    Soil moisture is one of the terrestrial essential climate variables that has critical role in the water, energy, and carbon cycles. There are different ways available for the retrieval of this essential variable (e.g., remote sensing, hydrological models, insitu measurements, and etc.). However, the time series of these retrievals often contain systematic differences, which need to be removed via different rescaling approaches before these data sets could be used in data fusion type studies. In this study, the added utility of nonlinear rescaling methods relative to linear methods in the framework of data fusion has been explored. Nonlinear rescaling methods implemented in this study include: multivariate adaptive regression splines (MARS), Support vector machines (SVM), and artificial neural network (ANN), while the linear methods include linear regression, variance-matching, and triple collocation. Land Parameter Retrieval Model (LPRM) and NOAH soil moisture datasets are rescaled into the space of in-situ measurements obtained over four United States Department of Agriculture (USDA) Agricultural Research Service (ARS) watersheds and later merged using a simple linear weighting method. Validation of the fused products using linear and nonlinear methods show that on average, fusing of nonlinearly rescaled LPRM and NOAH soil moisture products yields 3 percent correlation (i.e., against the in situ data) improvement against nonlinearly rescaled NOAH soil moisture product, while this improvement is more than 5 percent when the fused product is compared against the linearly rescaled NOAH product.

  2. Energy distribution among reaction products. VII - H + F2.

    NASA Technical Reports Server (NTRS)

    Polanyi, J. C.; Sloan, J. J.

    1972-01-01

    The 'arrested relaxation' variant of the IR chemiluminescence technique is used in a study of the distribution of vibrational, rotational and translational energies between the products of the reaction by which H + F2 yields HF + F. Diagrams are plotted and numerical values are obtained for the energy distribution rate constants.

  3. Ozone-cyclohexene reaction in air: quantitative analysis of particulate products and the reaction mechanism

    SciTech Connect

    Hatakeyama, S.; Tanonaka, T.; Weng, J.; Bandow, H.; Takagi, H.; Akimot, H.

    1985-10-01

    Both gaseous and particulate products of the cyclohexene-ozone reaction were analyzed. Major gaseous products were aldehydes that consist of adipaldehyde (CHO(CH/sub 2/)/sub 4/CHO), glutaraldehyde (CHO(CH/sub 2/)/sub 3/CHO), and pentanal (CH/sub 3/(CH/sub 2/)/sub 3/CHO). The sum of the primary yields of aldehydes reaches as high as 50%. In addition to aldehydes, formic acid, CO, and CO/sub 2/ were produced, but formaldehyde was not detected. Main particulate products were adipaldehyde, 6-oxohexanoic acid (CHO(CH/sub 2/)/sub 4/COOH), adipic acid (HOOC(CH/sub 2/)/sub 4/COOH), glutaraldehyde, 5-oxopentanoic acid (CHO(CH/sub 2/)/sub 3/COOH), and glutaric acid (HOOC(CH/sub 2/)/sub 3/COOH). All these compounds were analyzed quantitatively, and the fraction of initial cyclohexene converted to aerosol organic carbon was estimated to be 13 +/- 3% as the value extrapolated to a ppm concentration range of reactants. Although the reaction mechanism is in general explainable in terms of the Criegee mechanism, the reaction pathway to form formic acid is quite unique in this reaction system. The entire mechanism was discussed on the basis of the quantitative product analysis data.

  4. Challenges on the road towards fusion electricity

    NASA Astrophysics Data System (ADS)

    Donné, Tony

    2016-11-01

    The ultimate aim of fusion research is to generate electricity by fusing light atoms into heavier ones, thereby converting mass into energy. The most efficient fusion reaction is based on merging the hydrogenic isotopes: Deuterium (2D) and Tritium (3T) into Helium (4He) and a neutron, which releases 17.6 MeV in the form of kinetic energy of the reaction products.

  5. Search for entrance channel effects in sub-barrier fusion reactions

    SciTech Connect

    Charlop, A.; Bierman, J.; Drebi, Z.; Garcia, A.; Gil, S.; Prindle, D.; Sonzogni, A.; Vandenbosch, R.; Ye, D. )

    1995-02-01

    In order to explore the possibility that previously observed anomalous mean angular momenta are related to the mass asymmetry of the entrance channel, we have studied three systems, [sup 28]Si + [sup 142]Ce, [sup 32]S + [sup 138]Ba, and [sup 48]Ti + [sup 122]Sn, all of which lead to the same compound nucleus, [sup 170]Hf. Gamma ray multiplicities for fusion have been determined using an electrostatic deflector and time of flight to identify the evaporation residues. Results have been obtained for bombarding energies from approximately 20% above the Coulomb barrier down to nearly 10% below the barrier. The mean angular momenta deduced from the gamma ray multiplicities are generally well reproduced by coupled channels calculations employing known deformation parameters and an estimate of the transfer strength and do not show any evidence of an unexpected effect related to the mass asymmetry of the entrance channel.

  6. Pion production in high-energy neutrino reactions with nuclei

    NASA Astrophysics Data System (ADS)

    Mosel, U.

    2015-06-01

    Background: A quantitative understanding of neutrino interactions with nuclei is needed for precision era neutrino long baseline experiments (MINOS, NOvA, DUNE) which all use nuclear targets. Pion production is the dominant reaction channel at the energies of these experiments. Purpose: Investigate the influence of nuclear effects on neutrino-induced pion production cross sections and compare predictions for pion-production with available data. Method: The Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) model is used for the description of all incoherent channels in neutrino-nucleus reactions. Results: Differential cross sections for charged and neutral pion production for the MINER ν A neutrino and antineutrino flux are calculated. An estimate for the coherent cross section is obtained from a comparison of data with theoretical results for incoherent cross sections. The invariant mass (W ) distribution of the Δ resonances produced is analyzed. Conclusions: Final state interactions affect the pion kinetic energy spectra significantly. The data for charged pion production at MINER ν A are compatible with the results of calculations using elementary data taken from an old Argonne National Laboratory experiment. Remaining differences for charged pion production can be attributed to coherent production; the data for antineutrino induced neutral pion production, where no coherent contribution is present, are reproduced quite well. The analysis of W distributions shows that sharp cuts on experimentally reconstructed invariant masses lead to shape distortions of the true W distributions for nuclear targets.

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

    SciTech Connect

    Zamrun, Muhammad; Usman, Ida; Variani, Viska Inda; Kassim, Hasan Abu

    2014-03-05

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

  8. Hydrogen production from methane through catalytic partial oxidation reactions

    NASA Astrophysics Data System (ADS)

    Freni, S.; Calogero, G.; Cavallaro, S.

    This paper reviews recent developments in syn-gas production processes used for partial methane oxidation with and/or without steam. In particular, we examined different process charts (fixed bed, fluidised bed, membrane, etc.), kinds of catalysts (powders, foams, monoliths, etc.) and catalytically active phases (Ni, Pt, Rh, etc.). The explanation of the various suggested technical solutions accounted for the reaction mechanism that may selectively lead to calibrated mixtures of CO and H 2 or to the unwanted formation of products of total oxidation (CO 2 and H 2O) and pyrolysis (coke). Moreover, the new classes of catalysts allow the use of small reactors to treat large amounts of methane (monoliths) or separate hydrogen in situ from the other reaction products (membrane). This leads to higher conversions and selectivity than could have been expected thermodynamically. Although catalysts based on Rh are extremely expensive, they can be used to minimise H 2O formation by maximising H 2 yield.

  9. Productive infection of human immunodeficiency virus type 1 in dendritic cells requires fusion-mediated viral entry

    SciTech Connect

    Janas, Alicia M.; Dong, Chunsheng; Wang Jianhua; Wu Li

    2008-06-05

    Human immunodeficiency virus type 1 (HIV-1) enters dendritic cells (DCs) through endocytosis and viral receptor-mediated fusion. Although endocytosis-mediated HIV-1 entry can generate productive infection in certain cell types, including human monocyte-derived macrophages, productive HIV-1 infection in DCs appears to be dependent on fusion-mediated viral entry. It remains to be defined whether endocytosed HIV-1 in DCs can initiate productive infection. Using HIV-1 infection and cellular fractionation assays to measure productive viral infection and entry, here we show that HIV-1 enters monocyte-derived DCs predominately through endocytosis; however, endocytosed HIV-1 cannot initiate productive HIV-1 infection in DCs. In contrast, productive HIV-1 infection in DCs requires fusion-mediated viral entry. Together, these results provide functional evidence in understanding HIV-1 cis-infection of DCs, suggesting that different pathways of HIV-1 entry into DCs determine the outcome of viral infection.

  10. Damage production and accumulation in SiC structures in inertial and magnetic fusion systems

    NASA Astrophysics Data System (ADS)

    Sawan, M. E.; Ghoniem, N. M.; Snead, L.; Katoh, Y.

    2011-10-01

    Radiation damage parameters in SiC/SiC composite structures are determined in both magnetic (MFE) and inertial (IFE) confinement fusion systems. Variations in the geometry, neutron energy spectrum, and pulsed nature of neutron production result in significant differences in damage parameters between the two systems. With the same neutron wall loading, the displacement damage rate in the first wall in an IFE system is ˜10% lower than in an MFE system, while gas production and burnup rates are a factor of 2 lower. Self-cooled LiPb and Flibe blankets were analyzed. While using LiPb results in higher displacement damage, Flibe yields higher gas production and burnup rates. The effects of displacement damage and helium production on defect accumulation in SiC/SiC composites are also discussed.

  11. Sorption enhanced reaction process (SERP) for production of hydrogen

    SciTech Connect

    Sircar, S.; Anand, M.; Carvill, B.

    1995-09-01

    Sorption Enhanced Reaction (SER) is a novel process that is being developed for the production of lower cost hydrogen by steam-methane reforming (SMR). In this process, the reaction of methane with steam is carried out in the presence of an admixture of a catalyst and a selective adsorbent for carbon dioxide. The consequences of SER are: (1) reformation reaction at a significantly lower temperature (300-500{degrees}C) than conventional SMR (800-1100{degrees}C), while achieving the same conversion of methane to hydrogen, (2) the product hydrogen is obtained at reactor pressure (200-400 psig) and at 99+% purity directly from the reactor (compared to only 70-75% H{sub 2} from conventional SMR reactor), (3) downstream hydrogen purification step is either eliminated or significantly reduced in size. The early focus of the program will be on the identification of an adsorbent/chemisorbent for CO{sub 2} and on the demonstration of the SER concept for SMR in our state-of-the-art bench scale process. In the latter stages, a pilot plant will be built to scale-up the technology and to develop engineering data. The program has just been initiated and no significant results for SMR will be reported. However, results demonstrating the basic principles and process schemes of SER technology will be presented for reverse water gas shift reaction as the model reaction. If successful, this technology will be commercialized by Air Products and Chemicals, Inc. (APCI) and used in its existing hydrogen business. APCI is the world leader in merchant hydrogen production for a wide range of industrial applications.

  12. Automatic polymerase chain reaction product detection system for food safety monitoring using zinc finger protein fused to luciferase.

    PubMed

    Yoshida, Wataru; Kezuka, Aki; Murakami, Yoshiyuki; Lee, Jinhee; Abe, Koichi; Motoki, Hiroaki; Matsuo, Takafumi; Shimura, Nobuaki; Noda, Mamoru; Igimi, Shizunobu; Ikebukuro, Kazunori

    2013-11-01

    An automatic polymerase chain reaction (PCR) product detection system for food safety monitoring using zinc finger (ZF) protein fused to luciferase was developed. ZF protein fused to luciferase specifically binds to target double stranded DNA sequence and has luciferase enzymatic activity. Therefore, PCR products that comprise ZF protein recognition sequence can be detected by measuring the luciferase activity of the fusion protein. We previously reported that PCR products from Legionella pneumophila and Escherichia coli (E. coli) O157 genomic DNA were detected by Zif268, a natural ZF protein, fused to luciferase. In this study, Zif268-luciferase was applied to detect the presence of Salmonella and coliforms. Moreover, an artificial zinc finger protein (B2) fused to luciferase was constructed for a Norovirus detection system. In the luciferase activity detection assay, several bound/free separation process is required. Therefore, an analyzer that automatically performed the bound/free separation process was developed to detect PCR products using the ZF-luciferase fusion protein. By means of the automatic analyzer with ZF-luciferase fusion protein, target pathogenic genomes were specifically detected in the presence of other pathogenic genomes. Moreover, we succeeded in the detection of 10 copies of E. coli BL21 without extraction of genomic DNA by the automatic analyzer and E. coli was detected with a logarithmic dependency in the range of 1.0×10 to 1.0×10(6) copies.

  13. The Trojan Horse Method as a tool for investigating astrophysically relevant fusion reactions

    NASA Astrophysics Data System (ADS)

    Lamia, L.; Spitaleri, C.; Tognelli, E.; Degl'Innocenti, S.; Pizzone, R. G.; Prada Moroni, P. G.

    2016-05-01

    The Trojan Horse Method (THM) has been largely adopted for investigating astrophysically relevant charged-particle induced reactions at Gamow energies. Indeed, THM allows one to by pass extrapolation procedures, thus overcoming this source of uncertainty. Here, the recent THM results and their impact in astrophysics are going to be discussed.

  14. Experiments on screening effect in deuteron fusion reactions at extremely low energies

    NASA Astrophysics Data System (ADS)

    Targosz-Ślȩczka, N.; Czerski, K.; Huke, A.; Ruprecht, G.; Weissbach, D.; Martin, L.; Kiliç, A. i.; Kaczmarski, M.; Winter, H.

    2013-10-01

    The enhanced electron screening effect in nuclear reactions taking place in dense astrophysical plasmas is extremely important for determination of stellar reaction rates in terrestrial laboratories as well as in prediction of cross sections enhancement in interiors of stars such as White and Brown Dwarfs or Giant Planets. This effect resulting in reduction of the nuclear Coulomb potential by the atomic electrons has been confirmed in many laboratory experiments. Unfortunately, experimental screening energies are much higher than the theoretical predictions and the reason for that remains unknown. Here, we present absorbing results of the experiment studying d + d nuclear reactions in different deuterized metallic targets under ultra high vacuum conditions. The total cross sections and angular distributions of the 2H( d, p)3H and 2H( d, n)3He reactions have been measured using a deuteron beam of energies between 8 and 30 keV provided by the electron cyclotron ion source. The atomic cleanness of the target surface has been secured by combining Ar sputtering of the target and Auger electrons spectroscopy. Due to application of an on-line analysis method, the homogeneity of the implanted deuteron densities could be continuously monitored. We will discuss probable causes of the large discrepancy between theoretical and experimental data.

  15. Probing the Structure of {sup 74}Ge Nucleus with Coupled-channels Analysis of {sup 74}Ge+{sup 74}Ge Fusion Reaction

    SciTech Connect

    Zamrun F, Muhammad; Kasim, Hasan Abu

    2010-12-23

    We study the fusion reaction of the {sup 74}Ge+{sup 74}Ge system in term of the full order coupled-channels formalism. We especially calculated the fusion cross section as well as the fusion barrier distribution of this reaction using transition matrix suggested by recent Coulomb excitation experiment. We compare the results with the one obtained by coupling matrix based on pure vibrational and rotational models. The present coupled-channels calculations for the barrier distributions obtained using experiment coupling matrix is in good agreement with the one obtained with vibrational model, in contrast to the rotational model. This is indicates that {sup 74}Ge nucleus favor a spherical shape than a deformed shape in its ground state. Our results will resolve the debates concerning the structure of this nucleus.

  16. Dynamical dipole mode in fusion reactions at 16 MeV/nucleon and beam energy dependence

    NASA Astrophysics Data System (ADS)

    Pierroutsakou, D.; Martin, B.; Agodi, C.; Alba, R.; Baran, V.; Boiano, A.; Cardella, G.; Colonna, M.; Coniglione, R.; Filippo, E. De; Zoppo, A. Del; Toro, M. Di; Inglima, G.; Glodariu, T.; Commara, M. La; Maiolino, C.; Mazzocco, M.; Pagano, A.; Parascandolo, C.; Piattelli, P.; Pirrone, S.; Rizzo, C.; Romoli, M.; Sandoli, M.; Santonocito, D.; Sapienza, P.; Signorini, C.

    2009-08-01

    High-energy γ rays and light charged particles from the Ar36+Zr96 and Ar40+Zr92 reactions at Elab=16 and 15.1 MeV/nucleon, respectively, were measured in coincidence with evaporation residues by means of the MEDEA multidetector array coupled to four parallel plate avalanche counters. The aim of this experiment was to investigate the prompt γ radiation, emitted in the decay of the dynamical dipole mode, in the ~16 MeV/nucleon energy range and to map its beam energy dependence, comparing the present results with our previous ones obtained at lower energies. The studied reactions populate, through entrance channels having different charge asymmetries, a compound nucleus in the region of Ce under the same conditions of excitation energy and spin. Light charged particle energy spectra were used to pin down the average excitation energy and the average mass of the system. By studying the γ-ray spectra of the charge symmetric reaction Ar40+Zr92, the statistical giant dipole resonance (GDR) parameters and angular distribution were extracted, and a comparison of the linearized 90°γ-ray spectra of the two reactions revealed a 12% extra yield in the GDR energy region for the more charge asymmetric system. The center-of-mass angular distribution data of this extra γ yield, compatible with a dipole oscillating along the symmetry axis of the dinuclear system, support its dynamical nature. The experimental findings are compared with theoretical predictions performed within a Boltzmann-Nordheim-Vlasov transport model and based on a collective bremsstrahlung analysis of the entrance channel reaction dynamics. An interesting sensitivity to the symmetry term of the equation of state and to in-medium effects on nucleon-nucleon (nn) cross sections is finally discussed.

  17. Ab initio many-body calculations of the (3)H(d,n)(4)He and (3)He(d,p)(4)He fusion reactions.

    PubMed

    Navrátil, Petr; Quaglioni, Sofia

    2012-01-27

    We apply the ab initio no-core shell model combined with the resonating-group method approach to calculate the cross sections of the (3)H(d,n)(4)He and (3)He(d,p)(4)He fusion reactions. These are important reactions for the big bang nucleosynthesis and the future of energy generation on Earth. Starting from a selected similarity-transformed chiral nucleon-nucleon interaction that accurately describes two-nucleon data, we performed many-body calculations that predict the S factor of both reactions. Virtual three-body breakup effects are obtained by including excited pseudostates of the deuteron in the calculation. Our results are in satisfactory agreement with experimental data and pave the way for microscopic investigations of polarization and electron-screening effects, of the (3)H(d,γn)(4)He bremsstrahlung and other reactions relevant to fusion research.

  18. A comparison of simple reaction time, visual discrimination and critical flicker fusion frequency in professional divers at elevated pressure.

    PubMed

    Tikkinen, Janne; Wuorimaa, Tomi; Siimes, Martti A

    2016-06-01

    Inert gas narcosis (IGN) impairs cognitive performance and some divers are more susceptible to IGN than others. We compared the sensitivity of two reaction time tests to detect changes in performance at pressure and compared these results with critical flicker fusion frequency (CFF) changes at the same ambient pressures. The study assessed simple reaction time (RT), mean time correct of the discrimination reaction time (MTC) and CFF in 30 professional divers breathing air at 101 kPa and 608 kPa in a hyperbaric chamber. RT and MTC increased at 608 kPa by 5.1 ± 9.4% (P = 0.04) and 7.3 ± 12.3% (P = 0.01) respectively. RT decreased to pre-compression level after decompression and MTC decreased to a level lower than pre-compression (P < 0.001) values. CFF increased by 2.5 ± 2.8% (P < 0.001) at 608 kPa. CFF decreased to pre-compression level after decompression. An increase in CFF was inversely correlated with a decrease in RT (r = 0.38, P = 0.04) and in MTC (r = 0.43, P = 0.02) at 608 kPa. Response speeds of the same subjects were impaired in both reaction time tasks at 608 kPa, whereas CFF increased at depth. An association between changes in response times and changes in CFF suggests that divers susceptible to IGN may also be susceptible to the effects of elevated oxygen partial pressure. If this holds true, the future selection of professional divers could be improved by the use of simple cognitive tests.

  19. Higgs production in bottom-quark fusion: Matching beyond leading order

    NASA Astrophysics Data System (ADS)

    Forte, Stefano; Napoletano, Davide; Ubiali, Maria

    2016-12-01

    We compute the total cross-section for Higgs boson production in bottom-quark fusion using the so-called FONLL method for the matching of a scheme in which the b-quark is treated as a massless parton to that in which it is treated as a massive final-state particle, and extend our previous results to the case in which the next-to-next-to-leading-log five-flavour scheme result is combined with the next-to-leading-order O (αs3) four-flavour scheme computation.

  20. Higgs characterisation via vector-boson fusion and associated production: NLO and parton-shower effects.

    PubMed

    Maltoni, Fabio; Mawatari, Kentarou; Zaro, Marco

    Vector-boson fusion and associated production at the LHC can provide key information on the strength and structure of the Higgs couplings to the Standard Model particles. Using an effective field theory approach, we study the effects of next-to-leading order (NLO) QCD corrections matched to a parton shower on selected observables for various spin-0 hypotheses. We find that inclusion of NLO corrections is needed to reduce the theoretical uncertainties on the total rates as well as to reliably predict the shapes of the distributions. Our results are obtained in a fully automatic way via FeynRules and MadGraph5_aMC@NLO.

  1. Maillard reaction products from chitosan-xylan ionic liquid solution.

    PubMed

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. N(pro) fusion technology: On-column complementation to improve efficiency in biopharmaceutical production.

    PubMed

    Schindler, S; Missbichler, B; Walther, C; Sponring, M; Cserjan-Puschmann, M; Auer, B; Schneider, R; Dürauer, A

    2016-04-01

    N(pro) fusion technology, a highly efficient system for overexpression of proteins and peptides in Escherichia coli, was further developed by splitting the autoprotease N(pro) into two fragments to generate a functional complementation system. The size of the expression tag is thus reduced from 168 to 58 amino acids, so by 66%. Upon complementation of the fragments auto-proteolytic activity is restored. This process has been shown for three model proteins of different size, a short 16 aa-peptide, MCP-1, and lysozyme. Moreover, the complementation was still functional after immobilization of the N-terminal fragment to a solid support which enables recycling of the immobilized fragment. This strategy enhances overall productivity of N(pro) Fusion Technology and thus allows more efficient production of recombinant proteins with reduced costs and in higher yields. Overall, the N(pro) complementation system has, depending on the size of the target molecule, potential to increase the productivity up to 4 fold for batch refolding and even more for on-column refolding strategies by the proven possibility of regeneration of the immobilized fragment.

  3. Evidence for vector-boson fusion production of H --> WW* --> lνlν

    NASA Astrophysics Data System (ADS)

    Chang, Philip; Atlas Collaboration

    2015-04-01

    Evidence for the vector-boson fusion (VBF) production of the Higgs boson in its WW* decay channel in the dilepton final state is reported. The analysis was performed on 7 and 8 TeV pp collisions recorded by the ATLAS detector with an integrated luminosity of 25fb-1 . One of the main improvements over the previous result is the adoption of multivariate technique for an improved sensitivity to the VBF signal. For a Higgs boson mass of 125.36 GeV, the best-fit value for the ratio of the signal strength for gluon fusion (ggF) and VBF production, μmath VBF /μggF , is measured to be 1 . 26-0.45+0.61 (stat .) -0.26+0.50 (syst .) . The observed significance of the VBF production is 3.2 standard deviations; the expected is 2.7 standard deviations. This marks the final run 1 measurement in this channel; the inclusion of the upcoming run 2 data will improve the precision further and take us to the next step towards the Higgs boson precision era.

  4. Higgs pair production in vector-boson fusion at the LHC and beyond.

    PubMed

    Bishara, Fady; Contino, Roberto; Rojo, Juan

    2017-01-01

    The production of pairs of Higgs bosons at hadron colliders provides unique information on the Higgs sector and on the mechanism underlying electroweak symmetry breaking (EWSB). Most studies have concentrated on the gluon-fusion production mode which has the largest cross section. However, despite its small production rate, the vector-boson fusion channel can also be relevant since even small modifications of the Higgs couplings to vector bosons induce a striking increase of the cross section as a function of the invariant mass of the Higgs boson pair. In this work we exploit this unique signature to propose a strategy to extract the hhVV quartic coupling and provide model-independent constraints on theories where EWSB is driven by new strong interactions. We take advantage of the higher signal yield of the [Formula: see text] final state and make extensive use of jet-substructure techniques to reconstruct signal events with a boosted topology, characteristic of large partonic energies, where each Higgs boson decays to a single collimated jet. Our results demonstrate that the hhVV coupling can be measured with 45% (20%) precision at the LHC for [Formula: see text] (3000) fb[Formula: see text], while a 1% precision can be achieved at a 100 TeV collider.

  5. Isotopic resolution of fission fragments from 238U+12C transfer and fusion reactions

    NASA Astrophysics Data System (ADS)

    Caamaño, M.; Rejmund, F.; Derkx, X.; Schmidt, K.-H.; Andouin, L.; Bacri, C.-O.; Barreau, G.; Benlliure, J.; Casarejos, E.; Fernández-Domínguez, B.; Gaudefroy, L.; Golabek, C.; Jurado, B.; Lemasson, A.; Navin, A.; Rejmund, M.; Roger, T.; Shrivastava, A.; Schmitt, C.; Taieb, J.

    2009-10-01

    Recent results from an experiment at GANIL, performed to investigate the main properties of fission-fragment yields and energy distributions in different fissioning nuclei as a function of the excitation energy, in a neutron-rich region of actinides, are presented. Transfer reactions in inverse kinematics between a 238U beam and a 12C target produced different actinides, within a range of excitation energy below 30 MeV. These fissioning nuclei are identified by detecting the target-like recoil, and their kinetic and excitation energy are determined from the reconstruction of the transfer reaction. The large-acceptance spectrometer VAMOS was used to identify the mass, atomic number and charge state of the fission fragments in flight. As a result, the characteristics of the fission-fragment isotopic distributions of a variety of neutron-rich actinides are observed for the first time over the complete range of fission fragments.

  6. Taste-active maillard reaction products: the "tasty" world of nonvolatile maillard reaction products.

    PubMed

    Hofmann, Thomas

    2005-06-01

    This study was done to obtain greater insight into the structures and sensory activities of those tastants that are not present in foods per se, but are generated during food processing by Maillard-type reactions from carbohydrates and amino acids and thus remain unknown. In order to rank the tastants according to their relative taste impact and to identify the key tastants generated during thermal food processing, the so-called taste dilution analysis (TDA), which uses the human tongue as a biosensor for tastants, was applied to heated, intensely bitter tasting binary mixtures of glucose or xylose and proline or alanine, respectively. This screening technique led to the identification of previously unknown taste compounds, among which intensely bitter tastants such as quinizolate and homoquinizolate, a pungent-tasting pyranopyranone, cyclopentenone derivatives exhibiting a physiological cooling effect, as well as a taste-enhancing pyridinium betaine named alapyridaine will be presented.

  7. Dual Position Sensitive MWPC for tracking reaction products at VAMOS++

    NASA Astrophysics Data System (ADS)

    Vandebrouck, M.; Lemasson, A.; Rejmund, M.; Fremont, G.; Pancin, J.; Navin, A.; Michelagnoli, C.; Goupil, J.; Spitaels, C.; Jacquot, B.

    2016-03-01

    The characteristics and performance of a Dual Position Sensitive Multi-Wire Proportional Counter (DPS-MWPC) used to measure the scattering angle, the interaction position on the target and the velocity of reaction products detected in the VAMOS++ magnetic spectrometer, are reported. The detector consists of a pair of position sensitive low pressure MWPCs and provides both fast timing signals, along with the two-dimensional position coordinates required to define the trajectory of the reaction products. A time-of-flight resolution of 305(11) ps (FWHM) was measured. The measured resolutions (FWHM) were 2.5(3) mrad and 560(70) μm for the scattering angle and the interaction point at the target respectively. The subsequent improvement of the Doppler correction of the energy of the γ-rays, detected in the γ-ray tracking array AGATA in coincidence with isotopically identified ions in VAMOS++, is also discussed.

  8. Product detection of the CH radical reaction with acetaldehyde.

    PubMed

    Goulay, Fabien; Trevitt, Adam J; Savee, John D; Bouwman, Jordy; Osborn, David L; Taatjes, Craig A; Wilson, Kevin R; Leone, Stephen R

    2012-06-21

    The reaction of the methylidyne radical (CH) with acetaldehyde (CH(3)CHO) is studied at room temperature and at a pressure of 4 Torr (533.3 Pa) using a multiplexed photoionization mass spectrometer coupled to the tunable vacuum ultraviolet synchrotron radiation of the Advanced Light Source at Lawrence Berkeley National Laboratory. The CH radicals are generated by 248 nm multiphoton photolysis of CHBr(3) and react with acetaldehyde in an excess of helium and nitrogen gas flow. Five reaction exit channels are observed corresponding to elimination of methylene (CH(2)), elimination of a formyl radical (HCO), elimination of carbon monoxide (CO), elimination of a methyl radical (CH(3)), and elimination of a hydrogen atom. Analysis of the photoionization yields versus photon energy for the reaction of CH and CD radicals with acetaldehyde and CH radical with partially deuterated acetaldehyde (CD(3)CHO) provides fine details about the reaction mechanism. The CH(2) elimination channel is found to preferentially form the acetyl radical by removal of the aldehydic hydrogen. The insertion of the CH radical into a C-H bond of the methyl group of acetaldehyde is likely to lead to a C(3)H(5)O reaction intermediate that can isomerize by β-hydrogen transfer of the aldehydic hydrogen atom and dissociate to form acrolein + H or ketene + CH(3), which are observed directly. Cycloaddition of the radical onto the carbonyl group is likely to lead to the formation of the observed products, methylketene, methyleneoxirane, and acrolein.

  9. Polysorbate 80 in medical products and nonimmunologic anaphylactoid reactions.

    PubMed

    Coors, Esther A; Seybold, Heidi; Merk, Hans F; Mahler, Vera

    2005-12-01

    Polyoxyethylene-sorbitan-20-monooleate (also known as polysorbate 80 and Tween 80) is a solubilizing agent ubiquitously used in nutritives, creams, ointments, lotions, and multiple medical preparations (e.g., vitamin oils, vaccines, and anticancer agents) and as an additive in tablets. Whereas its relevance as a contact allergen has declined during the past decades, it is of current relevance as a "hidden" inductor of anaphylactoid reactions. To identify polysorbate 80 (generally believed to be an inert vehicle) as an inductor of a severe anaphylactoid reaction. Skin prick testing, enzyme-linked immunosorbent assay, IgE immunoblotting, and flow cytometric detection of basophil activation were performed in controls and in a patient with a medical history of anaphylactic shock due to intravenous administration of a multivitamin product during pregnancy. Polysorbate 80 was identified as the causative agent for the anaphylactoid reaction of nonimmunologic origin in the patient. Polysorbate specific IgE antibodies were not identified in enzyme-linked immunosorbent assay and immunoblot examinations, confirming the nonimmunologic nature of the anaphylactoid reaction. Polysorbate 80 is a ubiquitously used solubilizing agent that can cause severe nonimmunologic anaphylactoid reactions.

  10. Angular Distributions of η Meson Production in pp Reactions

    NASA Astrophysics Data System (ADS)

    Fröhlich, I.; Balestra, F.; Bedfer, Y.; Bertini, R.; Bland, L. C.; Brenschede, A.; Brochard, F.; Bussa, M. P.; Choi, Seonho; Colantoni, M. L.; Dressler, R.; Dzemidzic, M.; Faivre, J.-Cl.; Ferrero, A.; Ferrero, L.; Foryciarz, J.; Frolov, V.; Garfagnini, R.; Grasso, A.; Heinz, S.; Jacobs, W. W.; Kühn, W.; Maggiora, A.; Maggiora, M.; Manara, A.; Panzieri, D.; Pfaff, H.-W.; Piragino, G.; Popov, A.; Ritman, J.; Salabura, P.; Tchalyshev, V.; Tosello, F.; Vigdor, S. E.; Zosi, G.

    With the DISTO spectrometer, exclusive η production in pp collisions have been measured at kinetic energies of Tbeam=2.15, 2.50 and 2.85 GeV, respectively, via the π+π-π0 decay channel. The resulting angular distributions of the η are important for the interpretation of dilepton spectra obtained in elementary as well as heavy ion reactions.

  11. 48Ca+249Bk fusion reaction leading to element Z = 117: long-lived α-decaying 270Db and discovery of 266Lr.

    PubMed

    Khuyagbaatar, J; Yakushev, A; Düllmann, Ch E; Ackermann, D; Andersson, L-L; Asai, M; Block, M; Boll, R A; Brand, H; Cox, D M; Dasgupta, M; Derkx, X; Di Nitto, A; Eberhardt, K; Even, J; Evers, M; Fahlander, C; Forsberg, U; Gates, J M; Gharibyan, N; Golubev, P; Gregorich, K E; Hamilton, J H; Hartmann, W; Herzberg, R-D; Heßberger, F P; Hinde, D J; Hoffmann, J; Hollinger, R; Hübner, A; Jäger, E; Kindler, B; Kratz, J V; Krier, J; Kurz, N; Laatiaoui, M; Lahiri, S; Lang, R; Lommel, B; Maiti, M; Miernik, K; Minami, S; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Pang, G K; Papadakis, P; Renisch, D; Roberto, J; Rudolph, D; Runke, J; Rykaczewski, K P; Sarmiento, L G; Schädel, M; Schausten, B; Semchenkov, A; Shaughnessy, D A; Steinegger, P; Steiner, J; Tereshatov, E E; Thörle-Pospiech, P; Tinschert, K; Torres De Heidenreich, T; Trautmann, N; Türler, A; Uusitalo, J; Ward, D E; Wegrzecki, M; Wiehl, N; Van Cleve, S M; Yakusheva, V

    2014-05-02

    The superheavy element with atomic number Z=117 was produced as an evaporation residue in the (48)Ca+(249)Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope (294)117 and its decay products. A hitherto unknown α-decay branch in (270)Db (Z = 105) was observed, which populated the new isotope (266)Lr (Z = 103). The identification of the long-lived (T(1/2) = 1.0(-0.4)(+1.9) h) α-emitter (270)Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an "island of stability."

  12. Ca48+Bk249 Fusion Reaction Leading to Element Z =117: Long-Lived α-Decaying Db270 and Discovery of Lr266

    NASA Astrophysics Data System (ADS)

    Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; Ackermann, D.; Andersson, L.-L.; Asai, M.; Block, M.; Boll, R. A.; Brand, H.; Cox, D. M.; Dasgupta, M.; Derkx, X.; Di Nitto, A.; Eberhardt, K.; Even, J.; Evers, M.; Fahlander, C.; Forsberg, U.; Gates, J. M.; Gharibyan, N.; Golubev, P.; Gregorich, K. E.; Hamilton, J. H.; Hartmann, W.; Herzberg, R.-D.; Heßberger, F. P.; Hinde, D. J.; Hoffmann, J.; Hollinger, R.; Hübner, A.; Jäger, E.; Kindler, B.; Kratz, J. V.; Krier, J.; Kurz, N.; Laatiaoui, M.; Lahiri, S.; Lang, R.; Lommel, B.; Maiti, M.; Miernik, K.; Minami, S.; Mistry, A.; Mokry, C.; Nitsche, H.; Omtvedt, J. P.; Pang, G. K.; Papadakis, P.; Renisch, D.; Roberto, J.; Rudolph, D.; Runke, J.; Rykaczewski, K. P.; Sarmiento, L. G.; Schädel, M.; Schausten, B.; Semchenkov, A.; Shaughnessy, D. A.; Steinegger, P.; Steiner, J.; Tereshatov, E. E.; Thörle-Pospiech, P.; Tinschert, K.; Torres De Heidenreich, T.; Trautmann, N.; Türler, A.; Uusitalo, J.; Ward, D. E.; Wegrzecki, M.; Wiehl, N.; Van Cleve, S. M.; Yakusheva, V.

    2014-05-01

    The superheavy element with atomic number Z =117 was produced as an evaporation residue in the Ca48+Bk249 fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope 117294 and its decay products. A hitherto unknown α-decay branch in Db270 (Z =105) was observed, which populated the new isotope Lr266 (Z =103). The identification of the long-lived (T1/2=1.0-0.4+1.9 h) α-emitter Db270 marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an "island of stability."

  13. ρ0 Meson Production in the pp Reactions with Disto

    NASA Astrophysics Data System (ADS)

    Salabura, P.; Balestra, F.; Bedfer, Y.; Bertini, R.; Bland, L. C.; Brenschede, A.; Brochard, F.; Bussa, M. P.; Choi, Seonho; Colantoni, M. L.; Dressler, R.; Dzemidzic, M.; Faivre, J.-Cl.; Ferrero, A.; Ferrero, L.; Foryciarz, J.; Fröhlich, I.; Frolov, V.; Garfagnini, R.; Grasso, A.; Heinz, S.; Jacobs, W. W.; Kühn, W.; Maggiora, A.; Maggiora, M.; Manara, A.; Panzieri, D.; Pfaff, H.-W.; Piragino, G.; Popov, A.; Ritman, J.; Tchalyshev, V.; Tosello, F.; Vigdor, S. E.; Zosi, G.

    2003-01-01

    Total and differential cross sections for the exclusive reaction pp → ppρ0 observed via the π+π- decay channel have been measured at pbeam= 3.67 GeV/c. The observed total meson production cross section is determined to be (23.4 ± 0.8 ± 8)μb and is significantly lower than typical cross sections used in model calculations for heavy ion collisions. The differential cross sections measured indicate a strong anisotropy ( ˜ \\cos2 θ ρ0^ CM) in the ρ0 meson production.

  14. Plasma fusion and cold fusion

    SciTech Connect

    Hideo, Kozima

    1996-12-31

    Fundamental problems of plasma fusion (controlled thermonuclear fusion) due to the contradicting demands of the magnetic confinement of plasma and suppression of instabilities occurring on and in plasma are surveyed in contrast with problems of cold fusion. Problems in cold fusion due to the complicated constituents and types of force are explained. Typical cold fusion events are explained by a model based on the presence of trapped neutrons in cold fusion materials. The events include Pons-Fleishmann effect, tritium anomaly, helium 4 production, and nuclear transmutation. Fundamental hypothesis of the model is an effectiveness of a new concept--neutron affinity of elements. The neutron affinity is defined and some bases supporting it are explained. Possible justification of the concept by statistical approach is given.

  15. Production of recombinant human erythropoietin/Fc fusion protein by genetically manipulated chickens.

    PubMed

    Penno, Carlos Alberto; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

    2010-04-01

    We previously reported the production of human erythropoietin (hEpo) using genetically manipulated (GM) chickens. The recombinant hEpo was produced in the serum and egg white of the GM chickens, and the oligosaccharide chain structures of the serum-derived hEpo were more favorable than those of the egg white-derived hEpo. In the present study, a retroviral vector encoding an expression cassette for a fusion protein of hEpo and the Fc region of human immunoglobulin G (hEpo/Fc) was injected into developing chicken embryos, with the aim of recovering the serum-derived hEpo from egg yolk through the yolk accumulation mechanism of maternal antibodies. The GM chickens that hatched stably produced the hEpo/Fc fusion protein not only in their serum and egg white, but also in the egg yolk as expected. Lectin blot analyses revealed that significant amounts of the oligosaccharide chains of hEpo/Fc produced in the serum and eggs of GM chickens terminated with galactose, and that the oligosaccharide chains of the serum- and yolk-derived hEpo/Fc incorporated sialic acid residues. Moreover, biological activity assessment using Epo-dependent cells revealed that the yolk-derived hEpo/Fc exhibited a comparable performance to the serum- and CHO-derived hEpo/Fc. These results indicate that transport of Fc fusion proteins from the blood circulation to the yolk in chickens represents an effective strategy for the production of pharmaceutical glycoproteins using transgenic chicken bioreactors.

  16. The Fusion Energy Option

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    2004-06-01

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

  17. Multi-strangeness production in hadron induced reactions

    NASA Astrophysics Data System (ADS)

    Gaitanos, T.; Moustakidis, Ch.; Lalazissis, G. A.; Lenske, H.

    2016-10-01

    We discuss in detail the formation and propagation of multi-strangeness particles in reactions induced by hadron beams relevant for the forthcoming experiments at FAIR. We focus the discussion on the production of the decuplet-particle Ω and study for the first time the production and propagation mechanism of this heavy hyperon inside hadronic environments. The transport calculations show the possibility of Ω-production in the forthcoming P ‾ANDA-experiment, which can be achieved with measurable probabilities using high-energy secondary Ξ-beams. We predict cross sections for Ω-production. The theoretical results are important in understanding the hyperon-nucleon and, in particular, the hyperon-hyperon interactions also in the high-strangeness sector. We emphasize the importance of our studies for the research plans at FAIR.

  18. Fusion breeder: its potential role and prospects

    SciTech Connect

    Lee, J.D.

    1981-01-01

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

  19. Entrance channel dynamics of hot and cold fusion reactions leading to superheavy elements

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Maruhn, J. A.; Reinhard, P.-G.

    2010-06-01

    We investigate the entrance channel dynamics for the reactions Zn70+Pb208 and Ca48+U238 by using the fully microscopic time-dependent Hartree-Fock theory coupled with a density constraint. We calculate excitation energies and capture cross sections relevant for the study of superheavy formations. We discuss the deformation dependence of the ion-ion potential for the Ca48+U238 system and perform an alignment angle averaging for the calculation of the capture cross section. The results show that this approach can generate results in good agreement with experiments and other theories.

  20. Entrance channel dynamics of hot and cold fusion reactions leading to superheavy elements

    SciTech Connect

    Umar, A. S.; Oberacker, V. E.; Maruhn, J. A.; Reinhard, P.-G.

    2010-06-15

    We investigate the entrance channel dynamics for the reactions {sup 70}Zn+{sup 208}Pb and {sup 48}Ca+{sup 238}U by using the fully microscopic time-dependent Hartree-Fock theory coupled with a density constraint. We calculate excitation energies and capture cross sections relevant for the study of superheavy formations. We discuss the deformation dependence of the ion-ion potential for the {sup 48}Ca+{sup 238}U system and perform an alignment angle averaging for the calculation of the capture cross section. The results show that this approach can generate results in good agreement with experiments and other theories.

  1. Study of nuclear fusion-fission dynamics in 16O+194Pt reaction

    NASA Astrophysics Data System (ADS)

    Kapoor, K.; Verma, S.; Sharma, P.; Mahajan, R.; Kaur, N.; Kaur, G.; Behera, B. R.; Singh, K. P.; Singh, H.; Dubey, R.; Saneesh, N.; Jhingan, A.; Sugathan, P.; Mohanto, G.; Nayak, B. K.; Saxena, A.; Sharma, H. P.; Chamoli, S. K.; Mukul, I.; Kumar, A.

    2017-06-01

    Pre- and post-scission α-particle multiplicities have been measured for the reaction 16O + 194Pt at 98.4 MeV forming compound nucleus 210Rn. The α-particle's yield has been measured in coincidence with the fission fragments at various angles. The moving source analysis was performed to extract the alpha particle multiplicity which yielded the contribution of pre- and post- scission components. The pre-scission α-particle multiplicity has been compared with JOANNE2 statistical model code predictions to extract fission time scale and which is observed to be around 55zs (1zs=10-21s).

  2. Calculations of long-lived isomer production in neutron reactions

    SciTech Connect

    Chadwick, M.B.; Young, P.G.

    1991-01-01

    We have carried out theoretical calculations for the production of the long-lived isomers {sup 93m}Nb({1/2}{sup {minus}}, 16y), {sup 121m}Sn(11/2{minus}, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors. We consider (n, 2n), (n,n{prime}), and (n, {gamma}) production modes and compare our results both with experimental data (where available) and systematic. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. 16 refs., 8 figs.

  3. Hot fusion or cold fusion, best route to the SHEs?

    NASA Astrophysics Data System (ADS)

    Loveland, Walter

    2010-02-01

    Elements 102-113 have been synthesized using cold fusion reactions (Pb or Bi target nuclei, massive projectiles., E*=13 MeV, high survival probabilities,significant fusion hindrance). The production cross sections decrease with increasing ZCN with a cross section of 27 fb being measured for element 113. Synthesis of elements 102-108 by hot fusion reactions (actinide target nuclei, intermediate mass projectiles, E*=30-50 MeV, low survival probability, small fusion hindrance) shows decreasing production cross sections for Z=102 to Z=108 and then the cross sections level out at a few pb out to Z=118. Upper limit cross sections for the production of Z=120 nuclei in hot fusion reactions are ˜ 0.1 pb. How should one go forward to make nuclei with Z > 120 or with large neutron numbers, N ˜ 184? The cross section for the production of an evaporation residue, σEVR, is σEVR=σCNWsur where σCN is the complete fusion cross section and Wsur is the survival probability of the completely fused system. The complete fusion cross section can be written as σCN=∑J=0^J σcapture (Ec.m.,J)PCN( Ec.m.,J) where σcapture(Ec.m.,J) is the capture cross section and PCN is the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than reseparating (quasifission). I have used this formalism to make estimates of the best reactions to make new heavy nuclei using stable and radioactive beams. I conclude that stable beams offer the best opportunities to make new chemical elements and that radioactive beams offer new opportunities to make nuclei to study the atomic physics and chemistry of the heaviest elements. The radioactive beam reactions involve the light neutron-rich projectiles interacting in hot fusion reactions. If time permits I will also discuss recent experiments to make heavy nuclei using multi-nucleon transfer reactions. )

  4. Production of three-dimensional tissue-engineered cartilage through mutual fusion of chondrocyte pellets.

    PubMed

    Hoshi, K; Fujihara, Y; Mori, Y; Asawa, Y; Kanazawa, S; Nishizawa, S; Misawa, M; Numano, T; Inoue, H; Sakamoto, T; Watanabe, M; Komura, M; Takato, T

    2016-09-01

    In this study, the mutual fusion of chondrocyte pellets was promoted in order to produce large-sized tissue-engineered cartilage with a three-dimensional (3D) shape. Five pellets of human auricular chondrocytes were first prepared, which were then incubated in an agarose mold. After 3 weeks of culture in matrix production-promoting medium under 5.78g/cm(2) compression, the tissue-engineered cartilage showed a sufficient mechanical strength. To confirm the usefulness of these methods, a transplantation experiment was performed using beagles. Tissue-engineered cartilage prepared with 50 pellets of beagle chondrocytes was transplanted subcutaneously into the cell-donor dog for 2 months. The tissue-engineered cartilage of the beagles maintained a rod-like shape, even after harvest. Histology showed fair cartilage regeneration. Furthermore, 20 pellets were made and placed on a beta-tricalcium phosphate prism, and this was then incubated within the agarose mold for 3 weeks. The construct was transplanted into a bone/cartilage defect in the cell-donor beagle. After 2 months, bone and cartilage regeneration was identified on micro-computed tomography and magnetic resonance imaging. This approach involving the fusion of small pellets into a large structure enabled the production of 3D tissue-engineered cartilage that was close to physiological cartilage tissue in property, without conventional polyper scaffolds.

  5. Cold Fusion, A Journalistic Investigation

    NASA Astrophysics Data System (ADS)

    Krivit, Steven B.

    2005-03-01

    Author of the recent book, The Rebirth of Cold Fusion, and founder of New Energy Times, Steven B. Krivit presents a summary of cold fusion's, past, present and possible future. This talk will briefly review five highlights of the recent New Energy Times investigation into cold fusion research:1. Analysis of early studies that supposedly disproved cold fusion.2. Key early corroborations that supported the claims of Fleischmann and Pons.3. The evolving understanding of cold fusion reaction paths and by-products.4. A look at volumetric power density.5. Brief comparison of the progress in hot fusion research as compared to cold fusion research.New Energy Times, founded in 2000, is an independent communications company which currently specializes in reporting on cold fusion researchootnotetextReferences and copies of the presentation are available at www.newenergytimes.com/reports/aps2005.htmhttp://www.newenergytimes.com/reports/aps2005.htm. It has no affiliations with any organization, entity or party which invests in these technologies, nor any individual researcher or research facility.

  6. 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.

  7. Reaction products and mass balances from irradiated TCE vapor

    SciTech Connect

    Matthews, S.M.; Wang, F.T.; Mill, T.

    1995-12-31

    Trichloroethylene (TCE) vapor, at a concentration of 3000 ppmv in synthetic air, was sealed in Tedlar bags and irradiated with a 3.7 MeV electron beam. Bags of dry vapor and vapor at 90% relative humidity were irradiated. Doses up to 11 megarads (11 MR) were applied. Each bag was chemically analyzed for reaction products and a mass balance of the chlorine and carbon was obtained within the 11 MR dose range. The results of these radiolysis experiments and chemical analysis show that, given the proper treatment, the TCE concentration is reduced to below detection limit and the reaction products of the organic carbon and chlorine are carbon monoxide (CO), carbon dioxide (CO{sub 2}), chlorine gas (Cl{sub 2}) and hydrochloric acid (140). No detectable amounts of dichloroacetyl chloride (DCAC) or phosgene (PG) remained in the sample after proper treatment. DCAC and PG were found only as intermediary oxidation products of the TCE. High energy ionizing radiation, as electron beams and bremsstrahlung, is a new treatment technology for destroying toxic compounds and hazardous Wastes. A demonstration of complete destruction of organic products, using this treatment at standard temperature and pressure, is expected to help implement the use of this technology.

  8. Oxidation and volatilization of a niobium alloy. Fusion Safety Program/Activation Products Task

    SciTech Connect

    Smolik, G.R.; McCarthy, K.A.

    1992-07-01

    This report presents the findings from a preliminary investigation into oxidation and volatilization characteristics of a niobium alloy. Niobium is a candidate alloy for use in plasma facing components (PFCS) in experimental fusion reactors like the Intemational Thermonuclear Experimental Reactor (ITER). An experimental alloy was tailored to simulate small changes in chemistry which could result from transmutations from irradiation. The alloy was exposed in air and steam between 800{degree}C and 1200{degree}C. Volatilized products and hydrogen were collected and measured. Post-test examinations were also performed on the samples to determine the amount of material loss during the exposures. The obtained measurements of volatilization flux (g/m{sup 2}-s), hydrogen generation rates (liters/m{sup 2}-s), and recession rates (mm/s) are data which can be used for safety analyses and material performance to predict consequences which may result from an accident involving the ingress of air or steam into the plasma chamber of fusion reactor. In our volatility tests, only molybdenum and niobium were found at release levels above the detection limit. Although molybdenum is present at only 0.12 wt%, the quantities of this element volatilized in air are nearly comparable to the quantities of niobium released. The niobium release in steam is only three to four times higher than that of molybdenum in steam. The hydrogen production of the niobium alloy is compared with other PFC materials that we have tested, specifically, beryllium, graphite, and a tunesten alloy. At high temperatures, the hydrogen production rate of the niobium alloy is among the lowest of these materials, significantly lower than beryllium. To understand what this means in an accident situation, modeling is necessary to predict temperatures, and therefore total hydrogen production. The INEL is currently doing this modeling.

  9. Production and decay of baryonic resonances in pion induced reactions

    NASA Astrophysics Data System (ADS)

    Przygoda, Witold

    2016-11-01

    Pion induced reactions give unique opportunities for an unambiguous description of baryonic resonances and their coupling channels. A systematic energy scan and high precision data, in conjunction with a partial wave analysis, allow for the study of the excitation function of the various contributions. A review of available world data unravels strong need for modern facilities delivering measurements with a pion beam. Recently, HADES collaboration collected data in pion-induced reactions on light (12C) and heavy (74W) nuclei at a beam momentum of 1.7 GeV/c dedicated to strangeness production. It was followed by a systematic scan at four different pion beam momenta (0.656, 0.69, 0.748 and 0.8 GeV/c) in π- - p reaction in order to tackle the role of N(1520) resonance in conjunction with the intermediate ρ production. First results on exclusive channels with one pion (π- p) and two pions (nπ+π-, pπ-π0) in the final state are discussed.

  10. A study of switchgrass pyrolysis: Product variability and reaction kinetics

    NASA Astrophysics Data System (ADS)

    Bovee, Jonathan Matthew

    Samples of the same cultivar of cave-in-rock switchgrass were harvested from plots in Frankenmuth, Roger City, Cass County, and Grand Valley, Michigan. It was determined that variation exists, between locations, among the pyrolytic compounds which can lead to variability in bio-oil and increased processing costs at bio-refineries to make hydrocarbon fuels. Washed and extractives-free switchgrass samples, which contain a lower alkali and alkaline earth metals content than untreated samples, were shown to produce lower amounts of acids, esters, furans, ketones, phenolics, and saccharides and also larger amounts of aldehydes upon pyrolysis. Although the minerals catalyzed pyrolytic reactions, there was no evidence indicating their effect on reducing the production of anhydrosugars, specifically levoglucosan. To further link minerals present in the biomass to a catalytic pathway, mathematic models were employed to determine the kinetic parameters of the switchgrass. While the calculated activation energies of switchgrass, using the FWO and KAS methods, were 227.7 and 217.8 kJ/mol, correspondingly, it was concluded that the activation energies for the switchgrass hemicellulose and cellulose peaks were 115.5 and 158.2 kJ/mol, respectively, using a modified model-fitting method. The minerals that effect the production of small molecules and levoglucosan also have an observable catalytic effect on switchgrass reaction rate, which may be quantifiable through the use of reaction kinetics so as to determine activation energy.

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

    SciTech Connect

    Rehm, K.E.; Jiang, C.L.; Esbensen, H.

    1995-08-01

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

  12. Production of Hev b5 as a fluorescent biotin-binding tripartite fusion protein in insect cells

    SciTech Connect

    Nordlund, Henri R. . E-mail: henri.nordlund@uta.fi; Laitinen, Olli H.; Uotila, Sanna T.H.; Kulmala, Minna; Kalkkinen, Nisse; Kulomaa, Markku S.

    2005-10-14

    The presented green fluorescent protein and streptavidin core-based tripartite fusion system provides a simple and efficient way for the production of proteins fused to it in insect cells. This fusion protein forms a unique tag, which serves as a multipurpose device enabling easy optimization of production, one-step purification via streptavidin-biotin interaction, and visualization of the fusion protein during downstream processing and in applications. In the present study, we demonstrate the successful production, purification, and detection of a natural rubber latex allergen Hev b5 with this system. We also describe the production of another NRL allergen with the system, Hev b1, which formed large aggregates and gave small yields in purification. The aggregates were detected at early steps by microscopical inspection of the infected insect cells producing this protein. Therefore, this fusion system can also be utilized as a fast indicator of the solubility of the expressed fusion proteins and may therefore be extremely useful in high-throughput expression approaches.

  13. Systematics of precise nuclear fusion cross sections: the need for a new dynamical treatment of fusion?

    NASA Astrophysics Data System (ADS)

    Newton, J. O.; Butt, R. D.; Dasgupta, M.; Hinde, D. J.; Gontchar, I. I.; Morton, C. R.; Hagino, K.

    2004-04-01

    A large number of precision fusion excitation functions, at energies above the average fusion barriers, have been fitted using the Woods-Saxon form for the nuclear potential. Values of the empirical diffuseness parameter greatly exceed those which generally reproduce elastic scattering data and tend to increase strongly with the reaction charge product Z1Z2. Possible reasons for this may lie in the Woods-Saxon form being inappropriate, or in the reduction of fusion cross sections by processes such as deep-inelastic collisions. These results point to a need for renewed efforts in dynamical calculations of fusion.

  14. Production of medical 99 m Tc isotope via photonuclear reaction

    NASA Astrophysics Data System (ADS)

    Fujiwara, M.; Nakai, K.; Takahashi, N.; Hayakawa, T.; Shizuma, T.; Miyamoto, S.; Fan, G. T.; Takemoto, A.; Yamaguchi, M.; Nishimura, M.

    2017-01-01

    99 m Tc with a 6 hour half-life is one of the most important medical isotopes used for the Single-Photon Emission Computed Tomography (SPECT) inspection in hospitals of US, Canada, Europe and Japan. 99 m Tc isotopes are extracted by the milking method from parent 99Mo isotopes with a 66 hour half-life. The supply of 99Mo isotopes now encounters a serious crisis. Hospitals may not suitably receive 99Mo medical isotopes in near future, due to difficulties in production by research nuclear reactors. Many countries are now looking for alternative ways to generate 99Mo isotopes other than those with research reactors. We discuss a sustained availability of 99 m Tc isotopes via the nat Mo(γ, n) photonuclear reaction, and discuss to solve technical problems for extracting pure 99 m Tc isotopes from other output materials of photonuclear reactions.

  15. Theoretical aspects of product formation from the NCO + NO reaction

    SciTech Connect

    Lin, M.C.; He, Y. ); Melius, C.F. )

    1993-09-09

    The reaction of NCO with NO, an important elementary process involved in the reduction of NO[sub x] by HNCO, has been studied theoretically using the BAC-MP4 technique in conjunction with RRKM calculations. The computed molecular structures and thermochemical data for various intermediates and transition states suggest that the reaction takes place primarily via the singlet, ground electronic state OCNNO molecule according to the following mechanism; (step a) NCO + NO [leftrightarrow] [sup 1]OCNNO [yields] N[sub 2]O + CO; (step b) NCO + NO [leftrightarrow] [sup 1]OCNNO [yields] c-OCNNO[minus] N[sub 2] + CO[sub 2]. The formation of N[sub 2]O + CO occurs by the fragmentation of the singlet OCNNO intermediate step (a), whereas the production of N[sub 2] + CO[sub 2] by cyclization-fragmentation occurs via step b. The tight transition states leading to the formation of these products, coupled with the loose entrance channel, give rise to the experimentally observed strong negative temperature dependence which can be quantitatively accounted for by the results of RRKM calculations based on the BAC-MP4 data. The experimentally measured product branching ratio for channels a and b could be accounted for theoretically by lowering the calculated energy barrier for step a by 3.6 kcal/mol, corresponding to about 15% of the barrier height. 22 refs., 3 figs., 5 tabs.

  16. Manifestation of macroscopic correlations in elementary reaction kinetics. I. Irreversible reaction A +A→product

    NASA Astrophysics Data System (ADS)

    Doktorov, Alexander B.; Kipriyanov, Alexander A.; Kipriyanov, Alexey A.

    2010-05-01

    Using an modern many-particle method for the derivation of non-Markovian binary kinetic equations, we have treated theoretically the applicability of the encounter theory (ET) (the prototype of the collision theory) concepts to the widely known diffusion assisted irreversible bulk reaction A +A→product (for example, radical reaction) in dilute solutions. The method shows that the agreement with the ET is observed when the familiar integral ET is employed which in this method is just a step in the derivation of kinetic equations. It allows for two-particle correlations only, but fails to take account of correlation of reactant simultaneously with the partner of the encounter and the reactant in the bulk. However, the next step leading to the modified ET under transformation of equations to the regular form both extends the time range of the applicability of ET rate equation (as it was for reactions proceeding with one of the reactants in excess), and gives the equation of the generalized ET. In full agreement with physical considerations, this theory reveals macroscopic correlations induced by the encounters in the reservoir of free walks. This means that the encounters of reactants in solution are correlated on a rather large time interval of the reaction. Though any nonstationary (non-Markovian) effects manifest themselves rather weakly in the kinetics of the bimolecular reaction in question, just the existence of the revealed macroscopic correlations in the binary theory is of primary importance. In particular, it means that the well-known phenomena which are generally considered to be associated solely with correlation of particles on the encounter (for example, chemically induced dynamic nuclear polarization) may be induced by correlation in the reservoir of free random walks of radicals in solution.

  17. Manifestation of macroscopic correlations in elementary reaction kinetics. I. Irreversible reaction A+A-->product.

    PubMed

    Doktorov, Alexander B; Kipriyanov, Alexander A; Kipriyanov, Alexey A

    2010-05-28

    Using an modern many-particle method for the derivation of non-Markovian binary kinetic equations, we have treated theoretically the applicability of the encounter theory (ET) (the prototype of the collision theory) concepts to the widely known diffusion assisted irreversible bulk reaction A+A-->product (for example, radical reaction) in dilute solutions. The method shows that the agreement with the ET is observed when the familiar integral ET is employed which in this method is just a step in the derivation of kinetic equations. It allows for two-particle correlations only, but fails to take account of correlation of reactant simultaneously with the partner of the encounter and the reactant in the bulk. However, the next step leading to the modified ET under transformation of equations to the regular form both extends the time range of the applicability of ET rate equation (as it was for reactions proceeding with one of the reactants in excess), and gives the equation of the generalized ET. In full agreement with physical considerations, this theory reveals macroscopic correlations induced by the encounters in the reservoir of free walks. This means that the encounters of reactants in solution are correlated on a rather large time interval of the reaction. Though any nonstationary (non-Markovian) effects manifest themselves rather weakly in the kinetics of the bimolecular reaction in question, just the existence of the revealed macroscopic correlations in the binary theory is of primary importance. In particular, it means that the well-known phenomena which are generally considered to be associated solely with correlation of particles on the encounter (for example, chemically induced dynamic nuclear polarization) may be induced by correlation in the reservoir of free random walks of radicals in solution.

  18. 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.

  19. Production of FMDV virus-like particles by a SUMO fusion protein approach in Escherichia coli

    PubMed Central

    Lee, Chien-Der; Yan, Yao-Pei; Liang, Shu-Mei; Wang, Ting-Fang

    2009-01-01

    Virus-like particles (VLPs) are formed by the self-assembly of envelope and/or capsid proteins from many viruses. Some VLPs have been proven successful as vaccines, and others have recently found applications as carriers for foreign antigens or as scaffolds in nanoparticle biotechnology. However, production of VLP was usually impeded due to low water-solubility of recombinant virus capsid proteins. Previous studies revealed that virus capsid and envelope proteins were often posttranslationally modified by SUMO in vivo, leading into a hypothesis that SUMO modification might be a common mechanism for virus proteins to retain water-solubility or prevent improper self-aggregation before virus assembly. We then propose a simple approach to produce VLPs of viruses, e.g., foot-and-mouth disease virus (FMDV). An improved SUMO fusion protein system we developed recently was applied to the simultaneous expression of three capsid proteins of FMDV in E. coli. The three SUMO fusion proteins formed a stable heterotrimeric complex. Proteolytic removal of SUMO moieties from the ternary complexes resulted in VLPs with size and shape resembling the authentic FMDV. The method described here can also apply to produce capsid/envelope protein complexes or VLPs of other disease-causing viruses. PMID:19671144

  20. Enhancing the specificity of the enterokinase cleavage reaction to promote efficient cleavage of a fusion tag.

    PubMed

    Shahravan, S Hesam; Qu, Xuanlu; Chan, I-San; Shin, Jumi A

    2008-06-01

    In our work with designed minimalist proteins based on the bZIP motif, we have found our His-tagged proteins to be prone to inclusion body formation and aggregation; we suspect this problem is largely due to the His tag, known to promote aggregation. Using AhR6-C/EBP, a hybrid of the AhR basic region and C/EBP leucine zipper, as representative of our bZIP-like protein family, we attempted removal of the His tag with enterokinase (EK) but obtained the desired cleavage product in very small yield. EK is known for proteolysis at noncanonical sites, and most cleavage occurred at unintended sites. We manipulated experimental conditions to improve specificity of proteolysis and analyzed the cleavage products; no effect was observed after changing pH, temperature, or the amount of EK. We then suspected the accessibility of the EK site was impeded due to protein aggregation. We found that the easily implemented strategy of addition of urea (1-4 M) greatly improved EK cleavage specificity at the canonical site and reduced adventitious cleavage. We believe that this enhancement in specificity is due to a more "open" protein structure, in which the now accessible canonical target can compete effectively with adventitious cleavage sites of related sequence.

  1. First Measurements of Deuterium-Tritium and Deuterium-Deuterium Fusion Reaction Yields in Ignition-Scalable Direct-Drive Implosions

    NASA Astrophysics Data System (ADS)

    Forrest, C. J.; Radha, P. B.; Knauer, J. P.; Glebov, V. Yu.; Goncharov, V. N.; Regan, S. P.; Rosenberg, M. J.; Sangster, T. C.; Shmayda, W. T.; Stoeckl, C.; Gatu Johnson, M.

    2017-03-01

    The deuterium-tritium (D-T) and deuterium-deuterium neutron yield ratio in cryogenic inertial confinement fusion (ICF) experiments is used to examine multifluid effects, traditionally not included in ICF modeling. This ratio has been measured for ignition-scalable direct-drive cryogenic DT implosions at the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997), 10.1016/S0030-4018(96)00325-2] using a high-dynamic-range neutron time-of-flight spectrometer. The experimentally inferred yield ratio is consistent with both the calculated values of the nuclear reaction rates and the measured preshot target-fuel composition. These observations indicate that the physical mechanisms that have been proposed to alter the fuel composition, such as species separation of the hydrogen isotopes [D. T. Casey et al., Phys. Rev. Lett. 108, 075002 (2012), 10.1103/PhysRevLett.108.075002], are not significant during the period of peak neutron production in ignition-scalable cryogenic direct-drive DT implosions.

  2. 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.

  3. Electrochemical product detection of an asymmetric convective polymerase chain reaction.

    PubMed

    Duwensee, Heiko; Mix, Maren; Stubbe, Marco; Gimsa, Jan; Adler, Marcel; Flechsig, Gerd-Uwe

    2009-10-15

    For the first time, we describe the application of heated microwires for an asymmetric convective polymerase chain reaction (PCR) in a modified PCR tube in a small volume. The partly single-stranded product was labeled with the electrochemically active compound osmium tetroxide bipyridine using a partially complementary protective strand with five mismatches compared to the single-stranded product. The labeled product could be successfully detected at a gold electrode modified with a complementary single-stranded capture probe immobilized via a thiol-linker. Our simple thermo-convective PCR yielded electrochemically detectable products after only 5-10 min. A significant discrimination between complementary and non-complementary target was possible using different immobilized capture probes. The total product yield was approx. half the amount of the classical thermocycler PCR. Numerical simulations describing the thermally driven convective PCR explain the received data. Discrimination between complementary capture probes and non-complementary capture probes was performed using square-wave voltammetry. The coupling of asymmetric thermo-convective PCR with electrochemical detection is very promising for future compact DNA sensor devices.

  4. Fusion: The controversy continues

    SciTech Connect

    1989-07-01

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

  5. Prediction of new particle emission on cold fusion

    SciTech Connect

    Matsumoto, T. . Dept. of Nuclear Engineering)

    1990-12-01

    In this paper the energy distribution of cold fusion products is analyzed based on the Nattoh model. A new hydrogen-catalyzed fusion reaction is proposed to occur in a metal. From the differences in the Q value and other parameters, a new particles, the iton, is predicted to be emitted, with a rest mass 2 to 26 times that of an electron.

  6. Isomer ratios for products of photonuclear reactions on 121Sb

    NASA Astrophysics Data System (ADS)

    Bezshyyko, Oleg; Dovbnya, Anatoliy; Golinka-Bezshyyko, Larisa; Kadenko, Igor; Vodin, Oleksandr; Olejnik, Stanislav; Tuller, Gleb; Kushnir, Volodymyr; Mitrochenko, Viktor

    2017-09-01

    Over the past several years various preequilibrium model approaches for nuclear reactions were developed. Diversified detailed experimental data in the medium excitation energy region for nucleus are needed for reasonable selection among these theoretical models. Lack of experimental data in this energy region does essentially limit the possibilities for analysis and comparison of different preequilibrium theoretical models. For photonuclear reactions this energy region extends between bremsstrahlung energies nearly 30-100 MeV. Experimental measurements and estimations of isomer ratios for products of photonuclear reactions with multiple particle escape on antimony have been performed using bremsstrahlung with end-point energies 38, 43 and 53 MeV. Method of induced activity measurement was applied. For acquisition of gamma spectra we used HPGe spectrometer with 20% efficiency and energy resolution 1.9 keV for 1332 keV gamma line of 60Co. Linear accelerator of electrons LU-40 was a source of bremsstrahlung. Energy resolution of electron beam was about 1% and mean current was within (3.8-5.3) μA.

  7. Dynamical explanation for the anomaly in the diffuseness parameter of the nucleus-nucleus potential in heavy-ion fusion reactions

    NASA Astrophysics Data System (ADS)

    Zanganeh, V.; Gharaei, R.; Wang, N.

    2017-03-01

    The abnormally large diffuseness parameter of the Woods-Saxon (WS) potential in heavy-ion fusion reactions is explained for the first time based on the microscopic dynamics simulations. With the improved quantum molecular dynamic (ImQMD) model, we systematically explore the dynamical processes in the fusion reactions 12C+92Zr , 16O+92Zr , 28Si+92Zr , 35Cl+92Zr , 40Ca+46Ti , and 16O+154Sm . Without introducing any free model parameters or additional assumptions, the microscopic ImQMD model can reproduce the measured fusion cross sections of all selected colliding systems with good accuracy. Due to the dynamical evolutions of the density distributions in the fusion processes, the energy dependence of nucleus-nucleus potential can be clearly observed. Based on the dynamical nucleus-nucleus potential of the ImQMD simulations, we extract the corresponding diffuseness parameters of the WS potential. The obtained values locate in a range between a =0.83 and 1.17 fm at different incident energies. In addition, the regular decreasing trend for the diffuseness parameter with the increase of the incident energies is also observed.

  8. DNA fusion product of phage P2 with plasmid pBR322 - A new phasmid

    NASA Technical Reports Server (NTRS)

    Nicoletti, M.; Bertani, G.

    1983-01-01

    The chromosome of the temperate bacteriophage P2 and that of the plasmid pBR322 have been joined in vitro after treatment with restriction endonuclease EcoRI. The fusion product - a phasmid - can behave as a plasmid, as a phage and as a prophage. It can replicate its DNA under the control of either the specific replication mechanism of the parent phage in a polA mutant or that of the parent plasmid in a rep mutant. Several interesting interactions between the two replication modes are indicated. In particular, phage particles may be produced even when the phage mode of DNA replication is blocked, and this throws new light on the involvement of the early gene A in the regulation of late gene expression in phage P2.

  9. DNA fusion product of phage P2 with plasmid pBR322 - A new phasmid

    NASA Technical Reports Server (NTRS)

    Nicoletti, M.; Bertani, G.

    1983-01-01

    The chromosome of the temperate bacteriophage P2 and that of the plasmid pBR322 have been joined in vitro after treatment with restriction endonuclease EcoRI. The fusion product - a phasmid - can behave as a plasmid, as a phage and as a prophage. It can replicate its DNA under the control of either the specific replication mechanism of the parent phage in a polA mutant or that of the parent plasmid in a rep mutant. Several interesting interactions between the two replication modes are indicated. In particular, phage particles may be produced even when the phage mode of DNA replication is blocked, and this throws new light on the involvement of the early gene A in the regulation of late gene expression in phage P2.

  10. Vector-Boson Fusion Higgs Production at Three Loops in QCD.

    PubMed

    Dreyer, Frédéric A; Karlberg, Alexander

    2016-08-12

    We calculate the next-to-next-to-next-to-leading-order (N^{3}LO) QCD corrections to inclusive vector-boson fusion Higgs production at proton colliders, in the limit in which there is no color exchange between the hadronic systems associated with the two colliding protons. We also provide differential cross sections for the Higgs transverse momentum and rapidity distributions. We find that the corrections are at the 1‰-2‰ level, well within the scale uncertainty of the next-to-next-to-leading-order calculation. The associated scale uncertainty of the N^{3}LO calculation is typically found to be below the 2‰ level. We also consider theoretical uncertainties due to missing higher order parton distribution functions, and provide an estimate of their importance.

  11. Fully Differential Vector-Boson-Fusion Higgs Production at Next-to-Next-to-Leading Order.

    PubMed

    Cacciari, Matteo; Dreyer, Frédéric A; Karlberg, Alexander; Salam, Gavin P; Zanderighi, Giulia

    2015-08-21

    We calculate the fully differential next-to-next-to-leading-order (NNLO) corrections to vector-boson fusion (VBF) Higgs boson production at proton colliders, in the limit in which there is no cross talk between the hadronic systems associated with the two protons. We achieve this using a new "projection-to-Born" method that combines an inclusive NNLO calculation in the structure-function approach and a suitably factorized next-to-leading-order VBF Higgs plus three-jet calculation, using appropriate Higgs plus two-parton counterevents. An earlier calculation of the fully inclusive cross section had found small NNLO corrections, at the 1% level. In contrast, the cross section after typical experimental VBF cuts receives NNLO contributions of about (5-6)%, while differential distributions show corrections of up to (10-12)% for some standard observables. The corrections are often outside the next-to-leading-order scale-uncertainty band.

  12. Higgs production via gluon fusion in k{sub T} factorisation

    SciTech Connect

    Hautmann, F.; Jung, H.; Pandis, V.

    2011-07-15

    Theoretical studies of Higgs production via gluon fusion are frequently carried out in the limit where the top quark mass is much larger than the Higgs mass, an approximation which reduces the top quark loop to an effective vertex. We present a numerical analysis of the error thus introduced by performing a Monte Carlo calculation for gg{yields}h in k{sub T}-factorisation, using the parton shower generator CASCADE. By examining both inclusive and exclusive quantities, we find that retaining the top-mass dependence results in only a small enhancement of the cross-section. We then proceed to compare CASCADE to the collinear Monte Carlos PYTHIA, MC-NLO and POWHEG.

  13. FEASIBILITY OF HYDROGEN PRODUCTION USING LASER INERTIAL FUSION AS THE PRIMARY ENERGY SOURCE

    SciTech Connect

    Gorensek, M

    2006-11-03

    The High Average Power Laser (HAPL) program is developing technology for Laser IFE with the goal of producing electricity from the heat generated by the implosion of deuterium-tritium (DT) targets. Alternatively, the Laser IFE device could be coupled to a hydrogen generation system where the heat would be used as input to a water-splitting process to produce hydrogen and oxygen. The production of hydrogen in addition to electricity would allow fusion energy plants to address a much wider segment of energy needs, including transportation. Water-splitting processes involving direct and hybrid thermochemical cycles and high temperature electrolysis are currently being developed as means to produce hydrogen from high temperature nuclear fission reactors and solar central receivers. This paper explores the feasibility of this concept for integration with a Laser IFE plant, and it looks at potential modifications to make this approach more attractive. Of particular interest are: (1) the determination of the advantages of Laser IFE hydrogen production compared to other hydrogen production concepts, and (2) whether a facility of the size of FTF would be suitable for hydrogen production.

  14. Role of Mediator and Effects of Temperature on ortho-C-N Bond Fusion Reactions of Aniline Using Ruthenium Templates: Isolation and Characterization of New Ruthenium Complexes of the in-Situ-Generated Ligands.

    PubMed

    Roy, Suman K; Sengupta, Debabrata; Rath, Santi Prasad; Saha, Tanushri; Samanta, Subhas; Goswami, Sreebrata

    2017-05-01

    In this work, ortho-C-N bond fusion reactions of aniline are followed by the use of two different ruthenium mediators. Reaction of aniline with [Ru(III)(terpy)Cl3] (terpy = 2,2':6',2″-terpyridine) resulted in a trans bis-aniline ruthenium(II) complex [1](+) which upon oxidation with H2O2 produced compound [2](+) of a bidentate ligand, N-phenyl-1,2-benzoquinonediimine, due to an oxidative ortho-C-N bond fusion reaction. Complex [1](+) and aniline (neat) at 185 °C produced a bis-chelated ruthenium complex (3). A previously reported complex [Ru(II)(N-phenyl-1,2-benzoquinonediimine)(aniline)2(Cl)2] (5) undergoes similar oxidation by air at 185 °C to produce complex [3]. A separate chemical reaction between aniline and strongly oxidizing tetra-n-propylammonium perruthenate [(n-pr)4N](+)[RuO4](-) in air produced a ruthenium complex [4] of a N(4)-tetraamidophenylmacrocycle ligand via multiple ortho-C-N bond fusion reaction. Notably, the yield of this product is low (5%) at 100 °C but increases to 25% in refluxing aniline. All these complexes are characterized fully by their physicochemical characterizations and X-ray structure determination. From their structural parameters and other spectroscopic studies, complex [2](+) is assigned as [Ru(II)(terpy)(N-phenyl-1,2-benzoquinonediimine)(Cl)](+) whereas complex [4] is described as a ruthenium(VI) complex comprised of a reduced deprotonated N-phenyl-1,2-diamidobenzene and N(4)-tetraamidophenylmacrocyclic ligand. Complex [2](+) exhibits one reversible oxidation at 1.32 V and one reversible reduction at -0.75 V vs Ag/AgCl reference electrode. EPR of the electrogenerated complexes has revealed that the oxidized complex is a ruthenium(III) complex with an axial EPR spectrum at gav= 2.06. The reduced complex [2], on the other hand, shows a single-line EPR signal at gav= 1.998. In contrast, complex [4] shows two successive one-electron oxidation waves at 0.5 and 0.8 V and an irreversible reduction wave at -0.9 V. EPR studies of

  15. High-level production of human interleukin-10 fusions in tobacco cell suspension cultures

    PubMed Central

    Kaldis, Angelo; Ahmad, Adil; Reid, Alexandra; McGarvey, Brian; Brandle, Jim; Ma, Shengwu; Jevnikar, Anthony; Kohalmi, Susanne E; Menassa, Rima

    2013-01-01

    The production of pharmaceutical proteins in plants has made much progress in recent years with the development of transient expression systems, transplastomic technology and humanizing glycosylation patterns in plants. However, the first therapeutic proteins approved for administration to humans and animals were made in plant cell suspensions for reasons of containment, rapid scale-up and lack of toxic contaminants. In this study, we have investigated the production of human interleukin-10 (IL-10) in tobacco BY-2 cell suspension and evaluated the effect of an elastin-like polypeptide tag (ELP) and a green fluorescent protein (GFP) tag on IL-10 accumulation. We report the highest accumulation levels of hIL-10 obtained with any stable plant expression system using the ELP fusion strategy. Although IL-10-ELP has cytokine activity, its activity is reduced compared to unfused IL-10, likely caused by interference of ELP with folding of IL-10. Green fluorescent protein has no effect on IL-10 accumulation, but examining the trafficking of IL-10-GFP over the cell culture cycle revealed fluorescence in the vacuole during the stationary phase of the culture growth cycle. Analysis of isolated vacuoles indicated that GFP alone is found in vacuoles, while the full-size fusion remains in the whole-cell extract. This indicates that GFP is cleaved off prior to its trafficking to the vacuole. On the other hand, IL-10-GFP-ELP remains mostly in the ER and accumulates to high levels. Protein bodies were observed at the end of the culture cycle and are thought to arise as a consequence of high levels of accumulation in the ER. PMID:23297698

  16. Integrated bioprocess for production of human proinsulin C-peptide via heat release of an intracellular heptameric fusion protein.

    PubMed

    Jonasson, P; Nygren, P A; Jörnvall, H; Johansson, B L; Wahren, J; Uhlén, M; Ståhl, S

    2000-01-21

    An integrated bioprocess has been developed suitable for production of recombinant peptides using a gene multimerization strategy and site-specific cleavage of the resulting gene product. The process has been used for production in E. coli of the human proinsulin C-peptide via a fusion protein BB-C7 containing seven copies of the 31-residues C-peptide monomer. The fusion protein BB-C7 was expressed at high level, 1.8 g l(-1), as a soluble gene product in the cytoplasm. A heat treatment procedure efficiently released the BB-C7 fusion protein into the culture medium. This step also served as an initial purification step by precipitating the majority of the host cell proteins, resulting in a 70% purity of the BB-C7 fusion protein. Following cationic polyelectrolyte precipitation of the nucleic acids and anion exchange chromatography, native C-peptide monomers were obtained by enzymatic cleavage at flanking arginine residues. The released C-peptide material was further purified by reversed-phase chromatography and size exclusion chromatography. The overall yield of native C-peptide at a purity exceeding 99% was 400 mg l(-1) culture, corresponding to an overall recovery of 56%. The suitability of this process also for the production of other recombinant proteins is discussed.

  17. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification.

    PubMed

    Li, Jianhua; Peng, Jianbiao; Zhang, Ya; Ji, Yuefei; Shi, Huanhuan; Mao, Liang; Gao, Shixiang

    2016-06-05

    This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H2O2 concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H2O2 concentration, while the optimal pH and H2O2 concentration were 7.0 and 8μM, respectively. 98% TCS was removed with only 0.1UmL(-1) SBP in 30min reaction time, while an HRP dose of 0.3UmL(-1) was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (KCAT) and catalytic efficiency (KCAT/KM) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via CC and CO coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water/wastewater treatment.

  18. Actinide Production in the Reaction of Heavy Ions withCurium-248

    SciTech Connect

    Moody, K.J.

    1983-07-01

    Chemical experiments were performed to examine the usefulness of heavy ion transfer reactions in producing new, neutron-rich actinide nuclides. A general quasi-elastic to deep-inelastic mechanism is proposed, and the utility of this method as opposed to other methods (e.g. complete fusion) is discussed. The relative merits of various techniques of actinide target synthesis are discussed. A description is given of a target system designed to remove the large amounts of heat generated by the passage of a heavy ion beam through matter, thereby maximizing the beam intensity which can be safely used in an experiment. Also described is a general separation scheme for the actinide elements from protactinium (Z = 91) to mendelevium (Z = 101), and fast specific procedures for plutonium, americium and berkelium. The cross sections for the production of several nuclides from the bombardment of {sup 248}Cm with {sup 18}O, {sup 86}Kr and {sup 136}Xe projectiles at several energies near and below the Coulomb barrier were determined. The results are compared with yields from {sup 48}Ca and {sup 238}U bombardments of {sup 248}Cm. Simple extrapolation of the product yields into unknown regions of charge and mass indicates that the use of heavy ion transfer reactions to produce new, neutron-rich above-target species is limited. The substantial production of neutron-rich below-target species, however, indicates that with very heavy ions like {sup 136}Xe and {sup 238}U the new species {sup 248}Am, {sup 249}Am and {sup 247}Pu should be produced with large cross sections from a {sup 248}Cm target. A preliminary, unsuccessful attempt to isolate {sup 247}Pu is outlined. The failure is probably due to the half life of the decay, which is calculated to be less than 3 minutes. The absolute gamma ray intensities from {sup 251}Bk decay, necessary for calculating the {sup 251}Bk cross section, are also determined.

  19. Fusion measurements in light and medium mass heavy-ion reactions. Progress report, June 1, 1980-May 31, 1981

    SciTech Connect

    Prosser, F.W.

    1981-01-01

    The data obtained for fusion residues from the /sup 16/ /sup 18/O + /sup 24/ /sup 26/Mg systems have been analyzed and are being compared to each other and to predictions from the fusion-evaporation code CASCADE. Analysis of data obtained for a small step excitation curve for the /sup 16/O + /sup 24/Mg system has been started to determine the possible presence of structure in the fusion cross section. Additional data for the fusion cross sections of these systems have been obtained at energies from 100 to 140 MeV at the ATLAS facility and are being analyzed. Initial measurements of the fusion-fission cross sections for /sup 58/Ni beams, at energies up to 320 MeV on targets from /sup 116/Sn to /sup 170/Yb have been made. Analysis is in progress and additional experiments are planned. A collaboration is planned at Notre Dame for experiments to determine the entry line for fusion in the /sup 12/C + /sup 16/O system, both for the interest in this system and for preparation for additional experiments at higher energies at Michigan State when the new facility there becomes available. These experiments should lead to information about the importance of incomplete fusion in this system. Experiments to test the limitation on fusion cross sections predicted by the rotating liquid drop model are planned as higher energies become available at ATLAS and MSU.

  20. Water-soluble reaction products from ozonolysis of grasses

    SciTech Connect

    Morrison, W.H. III; Akin, D.E. )

    1990-03-01

    Ozone has been used to pretreat agricultural byproducts with the aim of increasing nutritive value for ruminants. However, not all treatments with ozone result in enhanced digestibility, suggesting reaction products from ozone treatment of plants might inhibit rumen microbial activity. Coastal Bermuda grass (Cynodon dactylon L. Pers.) (CBG) and Kentucky-31 tall fescue (Festuca arundinacea Schreb.) (K-31) were treated with ozone and the water-soluble products determined. The following acids were identified: caproic, levulinic, p-hydroxybenzoic, vinillic, azelaic, and malonic. In addition, vanillin and p-hydroxybenzaldehyde were also identified. Ozone treatment of the cell walls of CBG produced mainly p-hydroxybenzoic acid, vanillic acid, azelaic acid, p-hydroxybenzaldehyde, and vanillin. Ozone treatment of K-31 cell walls produced levulinic acid in addition to those products found from CBG cell walls. The production of vanillin and p-hydroxybenzaldehyde, which have been shown to be especially toxic to rumen microorganisms, offers an explanation for the negative affects of ozone treatment on forage.

  1. Design Considerations for Clean QED Fusion Propulsion Systems

    NASA Astrophysics Data System (ADS)

    Bussard, Robert W.; Jameson, Lorin W.

    1994-07-01

    The direct production of electric power appears possible from fusion reactions between fuels whose products consist solely of charged particles and thus do not present radiation hazards from energetic neutron production, as do reactions involving deuteron-bearing fuels. Among these are the fuels p, 11B, 3He, and 6Li. All of these can be ``burned'' in inertial-electrostatic-fusion (IEF) devices to power QED fusion-electric rocket engines. These IEF sources provide direct-converted electrical power at high voltage (MeV) to drive e-beams for efficient propellant heating to extreme temperatures, with resulting high specific impulse performance capabilities. IEF/QED engine systems using p11B can outperform all other advanced concepts for controlled fusion propulsion by 2-3 orders of magnitude, while 6Li6Li fusion yields one order of magnitude less advance. Either of these fusion rocket propulsion systems can provide very rapid transit for solar system missions, with high payload fractions in single-stage vehicles. The 3He3He reaction can not be used practically for direct electric conversion because of the wide spread in energy of its fusion products. However, it may eventually prove useful for thermal/electrical power generation in central station power plants, or for direct-fusion-product (DFP) propellant heatingin advanced deep-space rocket engines.

  2. Review of fusion synfuels

    SciTech Connect

    Fillo, J.A.

    1980-01-01

    Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  3. H + CD4 abstraction reaction dynamics: product energy partitioning.

    PubMed

    Hu, Wenfang; Lendvay, György; Troya, Diego; Schatz, George C; Camden, Jon P; Bechtel, Hans A; Brown, Davida J A; Martin, Marion R; Zare, Richard N

    2006-03-09

    This paper presents experimental and theoretical studies of the product energy partitioning associated with the H + CD4 (nu = 0) --> HD + CD3 reaction for the collision energy range 0.5-3.0 eV. The theoretical results are based on quasiclassical trajectories from (1) first principles direct dynamics calculations (B3LYP/6-31G), (2) an empirical surface developed by Espinosa-García [J. Chem. Phys. 2002, 116, 10664] (EG), and (3) two semiempirical surfaces (MSINDO and reparametrized MSINDO). We find that most of the energy appears in product translation at energies just above the reactive threshold; however, HD vibration and rotation become quite important at energies above 1 eV, each accounting for over 20% of the available energy above 1.5 eV, according to the B3LYP calculations. The barrier on the B3LYP surface, though being later than that on EG, predicts significantly higher HD vibrational excitation than EG. This deviation is contradictory to what would be expected on the basis of the Polanyi rules and derives from modest differences in the potential energy surfaces. The CD3 internal energy is generally quite low, and we present detailed rotational state distributions which show that the CD3 rotational distribution is largely independent of collision energy in the 0.75-1.95 eV range. The most populated rotational levels are N = 5 and 6 on B3LYP, with most of that excitation being associated with motion about the C2 axes, rather than C3 axis, of the CD3 product, in good agreement with the experimental results. Through our extensive studies in this and previous work concerning the scattering dynamics, we conclude that B3LYP/6-31G provides the best available description of the overall dynamics for the title reaction at relatively high collision energies.

  4. Role of Barrier Modification and Inelastic Surface Excitations in Sub-Barrier Fusion of 16 32 S + 40 94 Zr Reaction

    NASA Astrophysics Data System (ADS)

    Gautam, Manjeet Singh; Rajni; Sharma, Manoj K.

    2016-04-01

    The fusion dynamics of 16 32 S + 40 94 Zr reaction at near and sub-barrier energies is investigated within the context of different theoretical approaches. The various theoretical models like one-dimensional Wong formula, ℓ-summed extended Wong formula, the energy-dependent Woods-Saxon potential model (EDWSP model), and coupled channel formulation have been used to address the impacts of nuclear structure degrees of freedom of the colliding pairs. The roles of different Skyrme forces along with Wong formalism are also tested in the analysis of the sub-barrier fusion dynamics of the 16 32 S + 40 94 Zr reaction. The influence of the low-lying surface vibrational states of the collision partners is investigated within the framework of coupled channel calculations performed by the code CCFULL. In the present work, it has been observed that the EDWSP model introduces barrier modification effects somewhat similar to those of the coupled channel approach, as well as those of using different Skyrme forces and hence it reasonably addresses the observed fusion data of 16 32 S + 40 94 Zr reaction in the close vicinity of the Coulomb barrier.

  5. Jet clustering dependence of Higgs boson production in vector-boson fusion

    NASA Astrophysics Data System (ADS)

    Rauch, Michael; Zeppenfeld, Dieter

    2017-06-01

    Precise predictions for Higgs production via vector-boson fusion (VBF) play an important role when testing the properties of the Higgs boson and probing new-physics effects. While the inclusive cross section changes little when including next-to-next-to-leading order (NNLO) and next-to-next-to-next-to-leading order QCD corrections, a differential NNLO calculation with typical VBF cuts [1] shows large corrections of up to 10% in distributions. In this article, we investigate the dependence of the differential NNLO QCD calculation on the jet definition. Starting from the known results at a fixed jet clustering choice, we use the electroweak H +3 jets production cross section at NLO precision to derive NNLO results for H +2 jets production for other jet definitions. We find that larger clustering radii significantly reduce the impact of NNLO corrections. The sizable NNLO corrections for distributions are largely caused by the broader energy flow inside jets at NNLO and are to be expected generally for processes with jets at leading order.

  6. Paramagnetic products of the reaction of hydrogen atoms with sodium azide

    SciTech Connect

    Vasil'ev, A.A.; Lisetskii, V.N.; Kulikov, N.F.; Savel'ev, G.G.

    1987-09-01

    The reaction of hydrogen atoms with sodium azide in high-frequency discharges has been postulated to lead to NaNH and molecular nitrogen as reaction products. This article investigates these products via electron spin resonance spectroscopy. Data are given on reaction and ionization kinetics as well as on the electronic structure and hyperfine interaction of the products.

  7. 40 CFR 721.4461 - Hydrofluoric acid, reaction products with octane (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hydrofluoric acid, reaction products... New Uses for Specific Chemical Substances § 721.4461 Hydrofluoric acid, reaction products with octane... identified generically as a hydrofluoric acid, reaction products with octane (PMN P-99-0052) is subject to...

  8. 40 CFR 721.4461 - Hydrofluoric acid, reaction products with octane (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Hydrofluoric acid, reaction products... New Uses for Specific Chemical Substances § 721.4461 Hydrofluoric acid, reaction products with octane... identified generically as a hydrofluoric acid, reaction products with octane (PMN P-99-0052) is subject to...

  9. 40 CFR 721.4461 - Hydrofluoric acid, reaction products with octane (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hydrofluoric acid, reaction products... New Uses for Specific Chemical Substances § 721.4461 Hydrofluoric acid, reaction products with octane... identified generically as a hydrofluoric acid, reaction products with octane (PMN P-99-0052) is subject to...

  10. 40 CFR 721.10428 - Fatty acids, C18-unsatd., dimers, reaction products with 1-piperazineethanamine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., reaction products with 1-piperazineethanamine. 721.10428 Section 721.10428 Protection of Environment..., reaction products with 1-piperazineethanamine. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as fatty acids, C18-unsatd., dimers, reaction products...

  11. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  12. 40 CFR 721.4461 - Hydrofluoric acid, reaction products with octane (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydrofluoric acid, reaction products... New Uses for Specific Chemical Substances § 721.4461 Hydrofluoric acid, reaction products with octane... identified generically as a hydrofluoric acid, reaction products with octane (PMN P-99-0052) is subject...

  13. 40 CFR 721.9265 - Reaction product of dichlorobenzidine and substituted alkylamide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction product of dichlorobenzidine... Significant New Uses for Specific Chemical Substances § 721.9265 Reaction product of dichlorobenzidine and... substance identified generically as a reaction product of dichlorobenzidine and substituted alkylamide...

  14. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propen-1-ol, reaction products with... Significant New Uses for Specific Chemical Substances § 721.10445 2-Propen-1-ol, reaction products with...) The chemical substance identified as 2-propen-1-ol, reaction products with hydrogen sulfide,...

  15. 40 CFR 721.4461 - Hydrofluoric acid, reaction products with octane (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrofluoric acid, reaction products... New Uses for Specific Chemical Substances § 721.4461 Hydrofluoric acid, reaction products with octane... identified generically as a hydrofluoric acid, reaction products with octane (PMN P-99-0052) is subject...

  16. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...

  17. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  18. 40 CFR 721.2582 - Reaction product of alkylene diamine, MDl, substituted carbomonocyclic amine and alkylamine...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reaction product of alkylene diamine... Reaction product of alkylene diamine, MDl, substituted carbomonocyclic amine and alkylamine (generic). (a... generically as reaction product of alkylene diamine, MDl, substituted carbomonocyclic amine and...

  19. 40 CFR 721.4385 - Hydrofluoric acid, reaction products with heptane.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydrofluoric acid, reaction products... Specific Chemical Substances § 721.4385 Hydrofluoric acid, reaction products with heptane. (a) Chemical... hydrofluoric acid, reaction products with heptane (PMN P-98-1036; CAS No. 207409-71-0) is subject to...

  20. 40 CFR 721.9270 - Reaction product of epoxy with anhydride and glycerol and glycol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reaction product of epoxy with... Significant New Uses for Specific Chemical Substances § 721.9270 Reaction product of epoxy with anhydride and... substance identified generically as reaction product of epoxy with anhydride and glycerol and glycol (PMN...