WorldWideScience

Sample records for low-energy three-nucleon photonuclear

  1. Final Technical Report Project: Low-Energy Photonuclear Studies at HIGS and Lund

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Gerald [George Washington Univ., Washington, DC (United States)

    2017-06-15

    This report summarizes a program of low-energy photonuclear studies at MAX-Lab in Lund (Sweden) and at the High Intensity Gamma Source (HIGS) at Duke University. A major emphasis has been on Compton scattering from deuterium in order to determine the electric and magnetic polarizabilities of the neutron. The studies at Lund utilized unpolarized photons at Egamma = 62-115 MeV to measure differential cross sections. The studies at HIGS utilized polarized and unpolarized photon beams (both linear and circular) at Egamma < 90 MeV. Polarization observables will be exploited to improve our understanding of the electric and magnetic polarizabilities, and in particular, double-polarization observables (using polarized targets) will be measured in the future to provide new information about the spin polarizabilities of the nucleon. The MAX-Lab experiments (using unpolarized photons) focused on an approved PAC proposal for Compton scattering on the deuteron aimed at making a precise determination of the electromagnetic polarizabilities of the neutron. At MAX-Lab we had three of the largest NaI detectors in the world, each capable of ~2% energy resolution. We have completed our measurements in two separate tagged photon energy ranges which overlap each other (62-97 MeV and 90-115 MeV) and the results of these experiments have been published. The photon beam at the High Intensity Gamma Source (HIGS) has several distinct advantages that make it unique: (1) ultra-high photon flux, ultimately reaching 100 MHz, (2) 100% linearly polarized photon beam, as well as circular polarization, (3) monoenergetic beam, with ~2% energy resolution, and (4) extremely low-background beam environment. Exploiting the high flux and polarization capabilities of the HIGS photon beam is central in the series of experiments being performed at this facility. Very little data exist on Compton scattering using polarized photons. We will exploit clear sensitivities in the polarization observables to the

  2. Three-nucleon forces

    International Nuclear Information System (INIS)

    Sauer, P.U.

    2014-01-01

    In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

  3. Three-nucleon scattering by using chiral perturbation theory potential

    International Nuclear Information System (INIS)

    Kamata, Hiroyuki

    2003-01-01

    Three-nucleon scattering problems are studied by using two-nucleon and three-nucleon potentials derived from chiral perturbation theory. The three-nucleon term is shown to appear in the effective potential of the rank of next-to-next-to-leading order (NNLO). New three-nucleon forces are taken into consideration in addition to the conventional Fujita-Miyazawa (FM) type three-nucleon potential. Two-nucleon potential of the chiral perturbation theory is as precise as the conventional ones in low energy region. The FM type three-nucleon force which explains Sagara discrepancy in high energy region is introduced automatically. Concerning the Ay puzzle, the results seems to behave as if the puzzle has been solved at the level of NLO, but at the NNLO (without three-nucleon force) level the result is similar to the cases of conventional potential indicating the need of three-nucleon force. In contrast to the FM type three-nucleon force, five free parameters exist in the new D and E type three-nucleon forces introduced by the NNLO, but they are reduced to two independent parameters by antisymmetrization, which are found to be sensitive to the coupling energy of tritons and to the nd scattering length (spin doublet state). Parameters determined from them cannot give satisfactory answer to the A y puzzle. It seems, however, too hasty to conclude that A y puzzle cannot be solved by the chiral perturbation theory. (S. Funahashi)

  4. Three-nucleon problem with phase equivalent potentials

    International Nuclear Information System (INIS)

    Pushkash, O.M.; Shapoval, D.V.; Simenog, I.V.

    1991-01-01

    The effect of the t-matrix off-shell variations with nonlocal phase equivalent N-N potentials on the three-nucleon parameters is studied. The variations, which lower or increase the tritium binding energy, are revealed. We show that under certain conditions, the three-nucleon low-energy observables are almost insensitive to the high energy behaviour of the negative parts of the scattering phase shifts. The inverse problem method is applied to reconstruct simple S-wave potentials which to provide a unified description of the two-nucleon and low-energy three-nucleon data. 22 refs.; 6 figs. (author)

  5. Photonuclear data

    International Nuclear Information System (INIS)

    Oblozinsky, Pavel

    2002-01-01

    We review the current status of photonuclear data, in particular in the light of recent major progress in developing internationally recognized library of evaluated photonuclear reaction data. The paper covers all aspects of photonuclear data, including experiments, photonuclear reaction theory, evaluation procedures, review of national photonuclear libraries, and description of the major IAEA library as well as its validation. This major library, prepared to suit transport calculations, contains data in the ENDF-6 format for 164 materials evaluated mostly up to 150 MeV. (author)

  6. Potentials of the inverse scattering problem in the three-nucleon problem

    International Nuclear Information System (INIS)

    Pushkash, A.M.; Simenog, I.V.; Shapoval, D.V.

    1993-01-01

    Possibilities of using the method of the inverse scattering problem for describing simultaneously the two-nucleon and the low-energy three-nucleon data in the S-interaction approximation are examined. 20 refs., 3 figs., 1 tab

  7. Qualitative treatment of three-nucleon properties

    International Nuclear Information System (INIS)

    Efimov, V.

    1981-01-01

    An attempt is made at consistent qualitative treatment of the three-nucleon system. The approach used is based on the physical concept of effective three-nucleon long-range interaction resulting from the existence of the deuteron and the virtual singlet deuteron. Within the framework of the approach, a qualitative treatment of the triton properties, nucleon-deuteron scattering, and triton-disintegration reactions is carried out. The following topics are dealt with: the Phillips line, the triton D-wave admixture, the doublet effective range of the n-d scattering, the triton virtual state, the anomaly of the n-d elastic cross section near the three-body threshold, and the partial cross sections of the inelastic n-d scattering and of the triton photo- and electrodisintegration. The discussion of these topics includes the evaluation of three-nucleon parameters and the qualitative interpretation of experimental data and calculation results; some predictions are also made. The results of our analysis lead to the conclusion that the concept of effective three-nucleon long-range interaction can indeed serve as grounds for consistent qualitative treatment of the three-nucleon phenomena. (orig.)

  8. Relativistic origin of three-nucleon force

    International Nuclear Information System (INIS)

    Haberzettl, H.; Parke, W.C.

    1995-01-01

    Based on the manifestly covariant cluster-dynamical formalism recently proposed by Haberzettl, the three-body forces entering three-nucleon equations are discussed. It is shown that there exist additional contributions to the (nonrelativistic) three-body force, not taken into account in the usual treatments, arising from the proper nonrelativistic limits of higher-order meson-exchange Feynman diagrams. Using the Paris potential, a five-channel triton bound-state calculation results in additional binding of about 0.6 MeV due to this new mechanism. copyright 1995 American Institute of Physics

  9. Three nucleon interaction and nuclear composition

    International Nuclear Information System (INIS)

    Pandharipande, V.R.

    1983-01-01

    The author discusses results of some of the calculations carried out by J. Carlson, I. Lagaris, J. Lomnitz-Adler, R.A. Smith, R.B. Wiringa and himself to study the three nucleon interaction. The group has attempted to calculate the wavefunctions and binding energies of 3 H, 3 He, 4 He and nuclear matter, with the variational method, from a nonrelativistic Hamiltonian. Only nucleon degrees of freedom are retained in this Hamiltonian; the effects of other degrees of freedom are implicit in the two and three nucleon potentials. The author discusses further the calculations carried out, in collaboration with B. Friman, and R.B. Wiringa, to study the composition of nuclei. Nucleons interact by many processes including exchange of pions with or without excitation to isobar (Δ) states. Thus the nucleus contains pions being exchanged, and some nucleons in the Δ state. The group attempts to calculate the number and momentum distribution of these exchanged pions, and the fraction of time a nucleon in the nucleus is in the Δ state. 21 references, 4 figures

  10. Three-nucleon forces and their importance in three-nucleon sys- tems and heavier nuclei

    NARCIS (Netherlands)

    Kalantar-Nayestanaki, N.

    2014-01-01

    Abstract In the past two decades, several laboratories have produced a large amount of data for cross sections, analyzing powers, and other spin observables from various reactions in the three-nucleon system. The experimental results are moderately described by only using the two-nucleon potentials

  11. Evaluation of the three-nucleon analyzing power puzzle

    International Nuclear Information System (INIS)

    Tornow, W.; Witala, H.

    1998-01-01

    The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the 3 P j nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the 3 P j nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the 3 P j nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the 3 P j nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.)

  12. Three-nucleon forces and the trinucleon bound states

    International Nuclear Information System (INIS)

    Friar, J.L.; Frois, B.

    1986-04-01

    A summary of the bound-state working group session of the ''International Symposium on the Three-Body Force in the Three-Nucleon System'' is presented. The experimental evidence for three-nucleon forces has centered on two ground state properties: the tritium binding energy and the trinucleon form factors. Both are discussed

  13. Evaluation of the three-nucleon analyzing power puzzle

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Univ. Nuclear Lab., Durham, NC (United States); Witala, H. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki

    1998-07-20

    The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the {sup 3}P{sub j} nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the {sup 3}P{sub j} nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the {sup 3}P{sub j} nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the {sup 3}P{sub j} nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.) 18 refs.

  14. Photonuclear reactions: astrophysical implications

    International Nuclear Information System (INIS)

    Nedorezov, V.G.

    2005-01-01

    Full text: Brief review on astrophysical aspects in photonuclear studies is presented. Main attention is paid on the two kind experiments. The first one was performed at ESRF by GRAAL collaboration using the back scattering laser photons technique to study light speed anisotropy with respect to the dipole of the Cosmic Microwave Background (CMB) radiation. This is a modern analog of the Michelson - Morley experiment. The results obtained are not only methologically different from those of the above mentioned experiments but also provide stronger constrains on the light speed anisotropy in CMB frame. Second subject is related to the electron scattering on exotic nuclei which can play significant role in explosive phenomena such as novae, supernovae and neutron stars. Such approach may be considered as the alternative to traditional low energy accelerator experiments. Exotic nuclei for these purposes can be obtained at CSI (ELISe project). The experiment is foreseen to be installed at the New Experimental Storage Ring (NESR) at RAIR where cooled secondary beams of radioactive ions will collide with an intense electron beam circulating in a small electron storage beam

  15. Two- and three-nucleon chiral interactions in quantum Monte Carlo calculations for nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, Joel [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Tews, Ingo [Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195 (United States); Carlson, Joseph; Gandolfi, Stefano [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Gezerlis, Alexandros [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Schmidt, Kevin [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Schwenk, Achim [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2016-07-01

    I present our recent work on Green's function Monte Carlo calculations of light nuclei using local two- and three-nucleon interactions derived from chiral effective field theory up to next-to-next-to-leading order (N{sup 2}LO). I discuss the choice of observables we make to fit the two low-energy constants which enter in the three-nucleon sector at N{sup 2}LO: the {sup 4}He binding energy and n-α elastic scattering P-wave phase shifts. I then show some results for light nuclei. I also show our results for the energy per neutron in pure neutron matter using the auxiliary-field diffusion Monte Carlo method and discuss regulator choices. Finally I discuss some exciting future projects which are now possible.

  16. Three-Nucleon Force Effects in p-"3H and n-"3He Scattering

    International Nuclear Information System (INIS)

    Viviani, M.; Kievsky, A.; Girlanda, L.; Marcucci, L. E.

    2017-01-01

    We present a preliminary study of the effect of a three-nucleon force (3NF) in p-"3H and n-"3 He scattering at low energies. The used 3NF is derived from effective field theory at next-to-next-to-leading order. The four-nucleon scattering observables are calculated using the Kohn variational principle and the hyperspherical harmonics technique and the results are compared with available experimental data. We have found that the effect of introducing this type of 3NF is tiny, and sometimes worsens the agreement with the experimental data. (author)

  17. Δ-excitations and the three-nucleon force

    International Nuclear Information System (INIS)

    Epelbaum, E.; Krebs, H.; Meissner, Ulf-G.

    2008-01-01

    We study the three-nucleon force in chiral effective field theory with explicit Δ-resonance degrees of freedom. We show that up to next-to-next-to-leading order, the only contribution to the isospin symmetric three-nucleon force involving the spin-3/2 degrees of freedom is given by the two-pion-exchange diagram with an intermediate delta, frequently called the Fujita-Miyazawa force. We also analyze the leading isospin-breaking corrections due to the delta. For that, we give the first quantitative analysis of the delta quartet mass splittings in chiral effective field theory including the leading electromagnetic corrections. The charge-symmetry breaking three-nucleon force due to an intermediate delta excitation is small, of the order of a few keV

  18. Quark cluster model in the three-nucleon system

    International Nuclear Information System (INIS)

    Osman, A.

    1986-11-01

    The quark cluster model is used to investigate the structure of the three-nucleon systems. The nucleon-nucleon interaction is proposed considering the colour-nucleon clusters and incorporating the quark degrees of freedom. The quark-quark potential in the quark compound bag model agrees with the central force potentials. The confinement potential reduces the short-range repulsion. The colour van der Waals force is determined. Then, the probability of quark clusters in the three-nucleon bound state systems are numerically calculated using realistic nuclear wave functions. The results of the present calculations show that quarks cluster themselves in three-quark systems building the quark cluster model for the trinucleon system. (author)

  19. KAERI photonuclear library

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jong Hwa; Lee, Young Ouk; Han, Yin Iu

    2000-03-01

    This report contains summary information and figures depicting the KAERI photonuclear data library that extends up to 140 MeV of incident photon. The library consists of 143 isotopes from C-12 to Bi-209, providing the photoabsorption cross section and the emission spectra for neutron, proton, deuteron, triton, alpha particles, and all residual nuclides in ENDF6 format. The contents of this report and ENDF-6 format data library are available at http://atom.kaeri.re.kr/.

  20. Three-body force in the three-nucleon system

    International Nuclear Information System (INIS)

    Gibson, B.F.

    1986-01-01

    A brief summary of the symposium is presented. Three-nucleon force models are discussed, including the two-pion exchange potential, NN-ΔN coupled-channels model, and phenomenological parametrization. Relevant experimental data and model calculations are discussed including form factors, binding energies, charge radii, and charge density for 3 H and 3 He. A calculation of the EMC effect for 3 He is also made using Sasakawa's wave function and compared to experimental data obtained at SLAC. The paper ends with discussions of proton-deuteron scattering, investigations at intermediate energies, and QCD efforts to understand the three-body problem

  1. The Sendai triton calculation with three-nucleon potentials

    International Nuclear Information System (INIS)

    Sasakawa, T.

    1986-01-01

    Where can we see the effects of quarks remains a fundamental question in nuclear theory physics. A bold approach is to try to reproduce physical quantities theoretically by utilizing a quark picture with imagination. A conservative but safer approach may be to study the triton as thoroughly as possible using realistic two- and three-nucleon potentials. We are taking the latter approach. In fact, our calculation of the EMC effect, which was one thought to be a realization of the quark-gluon picture of nuclei, suggests that we might not have to make recourse to this picture. The calculation was done for 3 He, while experimental data for 4 He are shown. We hope that an experiment for 3 He is done soon, to check whether our conservative approach actually works for the EMC effect. (orig./WL)

  2. Configuration space methods in the three-nucleon problem

    International Nuclear Information System (INIS)

    Friar, J.L.

    1985-01-01

    The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed. Those qualitative aspects of the two-nucleon problem which play an important role in the trinucleon are discussed. The geometrical aspects of the problem are developed, and the importance of the angular momentum barrier is demonstrated. The Faddeev-Noyes formulation of the Schroedinger equation is motivated, and the boundary conditions for various three-body problems is reviewed. The method of splines is shown to provide a particularly useful numerical modelling technique for solving the Faddeev-Noyes equation. The properties of explicit trinucleon solutions for various two-body force models are discussed, and the evidence for three-body forces is reviewed. The status of calculations of trinucleon observables is discussed, and conclusions are presented. 40 refs., 14 figs

  3. Comparative study of three-nucleon potentials in nuclear matter

    Science.gov (United States)

    Lovato, Alessandro; Benhar, Omar; Fantoni, Stefano; Schmidt, Kevin E.

    2012-02-01

    A new generation of local three-body potentials providing an excellent description of the properties of light nuclei, as well as of the neutron-deuteron doublet scattering length, has been recently derived. We have performed a comparative analysis of the equations of state of both pure neutron matter (PNM) and symmetric nuclear matter (SNM) at zero temperature obtained using these models of three-nucleon forces. In particular, we have carried out both variational and auxiliary field diffusion Monte Carlo calculations of the equation of state of PNM, while in the case of SNM we have only the variational approach has been considered. None of the considered potentials simultaneously explains the empirical equilibrium density and binding energy of symmetric nuclear matter. However, two of them provide reasonable values of the saturation density. The ambiguity concerning the treatment of the contact term of the chiral inspired potentials is discussed.

  4. Photonuclear physics at intermediate energies

    International Nuclear Information System (INIS)

    Arruda Neto, J.D.T.

    1984-01-01

    A review and a description of the state of the art in the field of photonuclear reactions is given. Future perspectives for works in this area in the linear accelarator laboratory at USP, Brazil are presented. (L.C.) [pt

  5. Three-nucleon hadronic and electromagnetic reactions with Δ-isobar excitation

    International Nuclear Information System (INIS)

    Deltuva, A.; Adam, J. Jr.; Fonseca, A.C.; Sauer, P.U.

    2005-01-01

    Three-nucleon hadronic and electromagnetic reactions are described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension CD-Bonn + Δ. Exact solutions of three-particle equations are employed for the initial and final states of the reactions. The Δ-isobar excitation yields an effective three-nucleon force and effective two- and three-nucleon currents beside other Δ-isobar effects; they are mutually consistent

  6. Electromagnetic properties of the three-nucleon ground state

    International Nuclear Information System (INIS)

    Strueve, W.

    1985-01-01

    The electromagnetic form factors of the three-nucleon ground state are calculated on the base of an exact solution of the Faddeev equations. In a Hilbert space of nucleons and a possible Δ-isobar the effects of a non-perturbative description of the Δ-isobar on the magnetic form factors are studied. Pure nucleonic current operators with two- and three-particle character can be described in the extended Hilbert space by simpler one-body operators. Additionally nonrelativistic meson-exchange corrections due to π and ρ exchange are calculated consistently with the requirements of current conservation. Further relativistic corrections are estimated on selected examples. The calculations yield a total magnetic contribution of the Δ-isobar which is smaller than hitherto assumed, a static approximation of the Δ propagation is proved as inadmissible and must be rejected. Together with the meson-exchange corrections a well agreement with the experimental data at low momentum transfers results. Especially the magnetic moments and magnetization radii can be explained. For higher momentum transfers the results show the importance of further corrections. The regard of selected relativistic corrections leads to a good description of the experimental magnetic form factors. Also by this way the position of the minimum and the height of the second maximum in the 3 He charge form factor can be explained. The comparison with the latest experimental results reveals furthermore unresolved problems in the description of the 3 H charge form factor. (orig.) [de

  7. Three-Nucleon Forces and Triplet Pairing in Neutron Matter

    Science.gov (United States)

    Papakonstantinou, P.; Clark, J. W.

    2017-12-01

    The existence of superfluidity of the neutron component in the core of a neutron star, associated specifically with triplet P-wave pairing, is currently an open question that is central to interpretation of the observed cooling curves and other neutron-star observables. Ab initio theoretical calculations aimed at resolving this issue face unique challenges in the relevant high-density domain, which reaches beyond the saturation density of symmetrical nuclear matter. These issues include uncertainties in the three-nucleon (3N) interaction and in the effects of strong short-range correlations—and more generally of in-medium modification of nucleonic self-energies and interactions. A survey of existing solutions of the gap equations in the triplet channel demonstrates that the net impact on the gap magnitude of 3N forces, coupled channels, and mass renormalization shows extreme variation dependent on specific theoretical inputs, in some cases even pointing to the absence of a triplet gap, thus motivating a detailed analysis of competing effects within a well-controlled model. In the present study, we track the effects of the 3N force and in-medium modifications in the representative case of the ^3P_2 channel, based on the Argonne v_{18} two-nucleon (2N) interaction supplemented by 3N interactions of the Urbana IX family. Sensitivity of the results to the input interaction is clearly demonstrated. We point out consistency issues with respect to the simultaneous treatment of 3N forces and in-medium effects, which warrant further investigation. We consider this pilot study as the first step toward a systematic and comprehensive exploration of coupled-channel ^3P F_2 pairing using a broad range of 2N and 3N interactions from the current generation of refined semi-phenomenological models and models derived from chiral effective field theory.

  8. Analysis of Three-Nucleon Forces Effects in the A = 3 System

    International Nuclear Information System (INIS)

    Kievsky, A.

    2011-01-01

    Using modern nucleon-nucleon interactions in the description of the A = 3, 4 nuclear systems the χ 2 per datum results to be much bigger than one. In particular it is not possible to reproduce the three- and four-nucleon binding energies and the n .d scattering length simultaneously. This is one manifestation of the necessity of including a three-nucleon force in the nuclear Hamiltonian. In this paper we perform an analysis of some, widely used, three-nucleon force models.We analyze their capability to describe the aforementioned quantities and, to improve their description, we propose modifications in the parametrization of the models. The effects of these new parametrizations are studied in some polarization observables at low energies. Due to the fact that some of the widely used TNF models do not reproduce simultaneously the triton and 4 He binding energies and the n -d doublet scattering length, possible modifications of their parametrizations have been analyzed. To this end we have used the AV18 as the reference NN interaction and we have analyze possible modifications of the URIX model. We have modified the regularization of the profile functions Y (r ) and T (r ) at the origin and we have introduced the Z 0 (r ) function in the central repulsive E-term. We have used one-parameter functions that have been chosen to match the short-range behavior of the corresponding functions in the N2LOL model. Furthermore the strengths of the b-, d-terms and E-terms have been fixed to reproduce the triton binding energy and 2 a nd . Then the predictions for some selected scattering observables in p - d scattering at 3 MeV have been compared to the results of the original model and the experimental data. We can observe that the description using the new parametrizations has the same quality of the original model. However, with the proposed parametrizations, the AV18+URIX model describes correctly B( 3 H) and 2 a nd . This analysis can be consider as a preliminary step in a

  9. Photonuclear reactions at intermediate energy

    International Nuclear Information System (INIS)

    Koch, J.H.

    1982-01-01

    The dominant feature of photonuclear reactions at intermediate energies is the excitation of the δ resonance and one can therefore use such reactions to study the dynamics of δ propagation in a nucleus. Following an introductory section the author comments on photoabsorption on a single nucleon in Section II. A review of the δ-n Greens function and of the photonuclear amplitude is given in Section III. Results for photoabsorption on 4 He are shown in Section IV and compared with the data. Coherent π 0 photoproduction is discussed in Section V and calculations for 12 C are compared to recent measurements. (Auth.)

  10. P-matrix approach and three-nucleon problem

    International Nuclear Information System (INIS)

    Babenko, V.A.; Petrov, N.M.; Teneva, G.N.

    1993-01-01

    The paper deals with the P-matrix approach application to the three strongly interacting particles systems description. On the basis of the obtained off-energy-shell scattering amplitude separable expansion in the P-matrix approach the low-energy three-particle quantities were calculated in the case of square-well potential. The results of calculations show good convergence of the calculated three-particle quantities. (author). 12 refs., 1 tab

  11. One, two or three-nucleon photo- absorption in 3He

    International Nuclear Information System (INIS)

    Tamas, G.

    1986-08-01

    Pion production and photodisintegration of 3 He are studied in the δ resonance region to try to separate the various photon absorption mechanism by one, two or three nucleons. The results are compared to the existing models

  12. Pionic retardation effects in two-pion-exchange three-nucleon forces

    International Nuclear Information System (INIS)

    Coon, S.A.; Friar, J.L.

    1986-01-01

    Those two-pion-exchange three-nucleon forces which arise from nuclear processes that involve only pions and nucleons are calculated. Among the processes which contribute are pion seagulls (e.g., nucleon-antinucleon pair terms) and overlapping, retarded pion exchanges. The resulting potential is shown to be a (v/c) 2 relativistic correction, and satisfies nontrivial constraints from special relativity. The relativistic ambiguities found before in treatments of relativistic corrections to the one-pion-exchange nuclear charge operator and two-body potential are also present in the three-nucleon potential. The resulting three-nucleon force differs from the original Tucson-Melbourne potential only in the presence of several new nonlocal terms, and in the specification of the choice of ambiguity parameters in the latter potential

  13. Pionic retardation effects in two-pion-exchange three-nucleon forces

    Science.gov (United States)

    Coon, S. A.; Friar, J. L.

    1986-09-01

    Those two-pion-exchange three-nucleon forces which arise from nuclear processes that involve only pions and nucleons are calculated. Among the processes which contribute are pion seagulls (e.g., nucleon-antinucleon pair terms) and overlapping, retarded pion exchanges. The resulting potential is shown to be a (v/c)2 relativistic correction, and satisfies nontrivial constraints from special relativity. The relativistic ambiguities found before in treatments of relativistic corrections to the one-pion-exchange nuclear charge operator and two-body potential are also present in the three-nucleon potential. The resulting three-nucleon force differs from the original Tucson-Melbourne potential only in the presence of several new nonlocal terms, and in the specification of the choice of ambiguity parameters in the latter potential.

  14. Pionic retardation effects in two-pion-exchange three-nucleon forces

    Energy Technology Data Exchange (ETDEWEB)

    Coon, S.A.; Friar, J.L.

    1986-09-01

    Those two-pion-exchange three-nucleon forces which arise from nuclear processes that involve only pions and nucleons are calculated. Among the processes which contribute are pion seagulls (e.g., nucleon-antinucleon pair terms) and overlapping, retarded pion exchanges. The resulting potential is shown to be a (v-italic/c-italic)/sup 2/ relativistic correction, and satisfies nontrivial constraints from special relativity. The relativistic ambiguities found before in treatments of relativistic corrections to the one-pion-exchange nuclear charge operator and two-body potential are also present in the three-nucleon potential. The resulting three-nucleon force differs from the original Tucson-Melbourne potential only in the presence of several new nonlocal terms, and in the specification of the choice of ambiguity parameters in the latter potential.

  15. General operator form of the non-local three-nucleon force

    Energy Technology Data Exchange (ETDEWEB)

    Topolnicki, K. [Jagiellonian University, M. Smoluchowski Institute of Physics, Krakow (Poland)

    2017-09-15

    This paper describes a procedure to obtain the general form of the three-nucleon force. The result is an operator form where the momentum space matrix element of the three-nucleon potential is written as a linear combination of 320 isospin-spin-momentum operators and scalar functions of momenta. Any spatial and isospin rotation invariant three-nucleon force can be written in this way and in order for the potential to be Hermitian, symmetric under parity inversion, time reversal and particle exchange, the scalar functions must have definite transformation properties under these discrete operations. A complete list of the isospin-spin-momentum operators and scalar function transformation properties is given. (orig.)

  16. Microscopic nucleon spectral function for finite nuclei featuring two- and three-nucleon short-range correlations: The model versus ab initio calculations for three-nucleon systems

    Science.gov (United States)

    Ciofi degli Atti, Claudio; Mezzetti, Chiara Benedetta; Morita, Hiko

    2017-04-01

    Background: Two-nucleon (2 N ) short-range correlations (SRC) in nuclei have been recently thoroughly investigated, both theoretically and experimentally and the study of three-nucleon (3 N ) SRC, which could provide important information on short-range hadronic structure, is underway. Novel theoretical ideas concerning 2 N and 3 N SRC are put forward in the present paper. Purpose: The general features of a microscopic one-nucleon spectral function which includes the effects of both 2 N and 3 N SRC and its comparison with ab initio spectral functions of the three-nucleon systems are illustrated. Methods: A microscopic and parameter-free one-nucleon spectral function expressed in terms of a convolution integral involving ab initio relative and center-of-mass (c.m.) momentum distributions of a 2 N pair and aimed at describing two- and three-nucleon short-range correlations, is obtained by using: (i) the two-nucleon momentum distributions obtained within ab initio approaches based upon nucleon-nucleon interactions of the Argonne family; (ii) the exact relation between one- and two-nucleon momentum distributions; (iii) the fundamental property of factorization of the nuclear wave function at short internucleon ranges. Results: The comparison between the ab initio spectral function of 3He and the one based upon the convolution integral shows that when the latter contains only two-nucleon short-range correlations the removal energy location of the peaks and the region around them exhibited by the ab initio spectral function are correctly predicted, unlike the case of the high and low removal energy tails; the inclusion of the effects of three-nucleon correlations brings the convolution model spectral function in much better agreement with the ab initio one; it is also found that whereas the three-nucleon short-range correlations dominate the high energy removal energy tail of the spectral function, their effects on the one-nucleon momentum distribution are almost one

  17. A new twist to the long-standing three-nucleon analyzing power puzzle

    Energy Technology Data Exchange (ETDEWEB)

    Neidel, E.M.; Tornow, W.; Gonzalez Trotter, D.E.; Howell, C.R.; Crowell, A.S.; Macri, R.A.; Walter, R.L.; Weisel, G.J.; Esterline, J.; Witala, H.; Crowe, B.J.; Pedroni, R.S.; Markoff, D.M

    2003-01-16

    New results for the neutron-deuteron analyzing power A{sub y}({theta}) at E{sub n}=1.2 and 1.9 MeV and their comparison to proton-deuteron data reveal a sizeable and unexpected difference which increases with decreasing center-of-mass energy. This finding calls for the theoretical treatment of a subtle electromagnetic effect presently not incorporated in rigorous three-nucleon scattering calculations, before it is justified to invoke charge-dependent three-nucleon forces and/or other new physics.

  18. The 20th anniversary of the three-nucleon analyzing power puzzle - a personal recollection

    International Nuclear Information System (INIS)

    Tornow, W. . Author

    2008-01-01

    The history of the three-nucleon analyzing power puzzle is described by an experimentalist who has been collaborating with few-body theoreticians in trying to unravel the physics of this long-standing phenomenon. Although surprising effects have been discovered along the way, the puzzle is still unexplained. Hopefully, some of the long-range three-nucleon force terms predicted by chiral effective field theory in N 3 LO will eventually solve the puzzle. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

  19. L-dependence in the 6Li induced three nucleon transfer excitation function

    International Nuclear Information System (INIS)

    Kraus, L.; Linck, I.

    1980-01-01

    The three nucleon transfer reactions induced by 6 Li on 12 C were studied from 5 to 9 MeV/n. The bell-shaped energy variation is used to select cluster states of progressively higher angular momentum. A modification to the Brink semi-classical model equations is proposed in order to reproduce the observed features

  20. Total disintegration of three-nucleon nuclei in charged-pion photo-production

    International Nuclear Information System (INIS)

    Dzhibuti, R.I.; Kezerashvili, R.Y.

    1984-01-01

    The total disintegration of three-nucleon nuclei in charged-pion photo-production is studied within the framework of the microscopic approach based on the method of hyperspherical functions. The initial and final nuclear states are described using the same NN potentials. The differential and total cross sections are calculated using various NN potentials. It is shown that the cross sections are sensitive to the form of the NN interaction and to the final-state interaction of the three nucleons. It is found that the cross section for π - meson production is systematically larger than the cross section for π + meson production. The importance of an experimental investigation of these reactions is shown

  1. Off-energy-shell variations of two-nucleon transition matrix and three-nucleon problem

    International Nuclear Information System (INIS)

    Stingl, M.; Sauer, P.U.

    1975-01-01

    For a schematic three-nucleon problem, approximate analytic expressions are derived for the functional derivatives of measurable three-particle quantities with respect to off-shell variations of the triplet-s two-nucleon transition matrix. Those quantities include neutron-deuteron scattering lengths, trinucleon binding energies, and the 3 He charge form-factor minimum; correlations between off-shell changes in the latter two are discussed. An indication is given how results of this kind may be to decide whether or not a given set of discrepancies between calculated and experimental three-nucleon observables can be reconciled in terms of off-shell variations of a nonretarded hermitean two-nucleon interaction. The treatment is not restricted to special classes of phase-shift equivalent potentials or phase-shift preserving transformations but instead makes use of a systematic parameterization of off-shell variations in terms of symmetric rational approximants of increasing order

  2. Investigation of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction

    Science.gov (United States)

    Ciepał, I.; Kłos, B.; Kistryn, St.; Stephan, E.; Biegun, A.; Bodek, K.; Deltuva, A.; Epelbaum, E.; Eslami-Kalantari, M.; Fonseca, A. C.; Golak, J.; Jha, V.; Kalantar-Nayestanaki, N.; Kamada, H.; Khatri, G.; Kirillov, Da.; Kirillov, Di.; Kliczewski, St.; Kozela, A.; Kravcikova, M.; Machner, H.; Magiera, A.; Martinska, G.; Messchendorp, J.; Nogga, A.; Parol, W.; Ramazani-Moghaddam-Arani, A.; Roy, B. J.; Sakai, H.; Sekiguchi, K.; Sitnik, I.; Siudak, R.; Skibiński, R.; Sworst, R.; Urban, J.; Witała, H.; Zejma, J.

    2014-08-01

    Precise and large sets of cross section, vector A x , A y and tensor A xx , A xy , A yy analyzing power data for the 1 H( d, pp) n breakup reactions were measured at 100 and 130 MeV deuteron beam energies with the SALAD and BINA detectors at KVI and the Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which model the three-nucleon system dynamics. The cross section data reveal a sizable three-nucleon force (3NF) and Coulomb force influence. In case of the analyzing powers very low sensitivity to these effects was found and the data are well describe by 2N models only. For A xy at 130 MeV, serious disagreements were observed when 3NF models are included in the calculations.

  3. Three-nucleon system dynamics studied via deuteron-proton breakup

    International Nuclear Information System (INIS)

    Kistryn, S.

    2011-01-01

    Nucleon-nucleon (NN) interaction is a basis for vast fields of fundamental nuclear physics and its application, therefore a detailed knowledge of the dynamics of few-nucleon systems has been a subject of intensive quest over several decades. Modern NN potential models can be probed quantitatively in the three-nucleon environment by comparing predictions based on rigorous solutions of the Faddeev equations with the measured observables. Proper description of the experimental data can be achieved only if the dynamical models include subtle effects of suppressed degrees of freedom, effectively introduced by means of genuine three-nucleon forces. A large set of high precision, exclusive cross-section data for the "1H(d,pp)n breakup reaction at 130 MeV, acquired in a first new-generation experiment at KVI Groningen, contributes significantly to constrain the physical assumptions underlying the theoretical interaction models. Comparison of nearly 1800 cross-section data points with the predictions using nuclear interactions generated in various ways, allowed to establish for the first time a clear evidence of importance of the three-nucleon forces in the breakup process. Moreover, the results, supplemented by a set of cross-sections from another dedicated experiment at FZ Juelich, confirmed predictions of sizable Coulomb force influences in this reaction. Following further, comparably rich and precise data sets, encompassing also polarization observables, will form a database to validate the theoretical models of few-nucleon system dynamics. (author)

  4. Photonuclear excitation of 103Rh by synchrotron radiation

    International Nuclear Information System (INIS)

    Yoshihara, Kenji; Kaji, Harumi; Sekine, Tsutomu; Mukoyama, Takeshi

    1989-01-01

    Photonuclear excitation of the 103 Rh nucleus was studied using synchrotron radiation. Formation of the excited state was confirmed by observing K X-rays emitted following the isomeric transition of the 103m Rh with a low-energy photon spectrometer. The intensity of induced activity due to 103 Rh(γ,γ') 103m Rh reaction was determined carefully by subtracting the fluorescent K X-rays due to natural background radiation. The integral cross-section for isomer production of 103m Rh by resonance absorption of photons at 295 keV is found to be (2.1±0.8) x 10 -28 cm 2 eV and is compared with that estimated from the previous experimental value for the 1277-keV level. (author)

  5. Photonuclear excitation of 103Rh by synchrotron radiation

    International Nuclear Information System (INIS)

    Kaji, Harumi; Yoshihara, Kenji; Mukoyama, Takeshi; Nakajima, Tetsuo

    1989-01-01

    Photonuclear excitation of 103 Rh nucleus was studied by the use of synchrotron radiation at KEK. Formation of excited state was confirmed by observing Rh K X-rays emitted following the isomeric transition of 103m Rh with a low-energy photon spectrometer. The induced activity due to 103 Rh(γ,γ') 103m Rh reaction was determined carefully by subtracting the fluorescent K X-rays due to natural background radiation. The integral cross-section for 103m Rh by resonance absorption at 295 keV is found to be (1∼2)x10 -28 cm 2 ·eV and is compared with that estimated from the previous experimental value for the 1277-keV level and the calculated value

  6. Some issues in photonuclear physics

    International Nuclear Information System (INIS)

    Tzara, C.

    1980-11-01

    Let us consider the simplest processes induced by the electromagnetic interaction, the emission or absorption of one photon. Their cross sections are unambiguously related to definite characteristics of the target, the charge and current form factors. In reality what is measured is different because higher order e.m. effects are unavoidable: (1) in photonuclear reactions, the radiative corrections, which are indeed negligible as long as the velocity imparted to the target or the emitted particles is small; (2) in contrast, the corrections to Born aproximation in electron scattering: distortion of the electron wave; two-photon exchange; radiative corrections, are far from negligible and pose eventually difficult problems. For the purpose of the following discussion, these will be considered as correctly handled, so that the final outcomes of the measurements are really form factors. At high energy, the so-called shadow effect comes into play. Whatever model is invoked to interpret it, the process is a one-photon and, as such, provides a form factor

  7. Photonuclear Physics in Radiation Transport - II: Implementation

    International Nuclear Information System (INIS)

    White, M.C.; Little, R.C.; Chadwick, M.B.; Young, P.G.; MacFarlane, R.E.

    2003-01-01

    This is the second of two companion papers. The first paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W, and Pb for incident photon energies up to 150 MeV. This paper describes the steps taken to process these files into transport libraries and to update the Monte Carlo N-Particle (MCNP) and MCNPX radiation transport codes to use tabular photonuclear reaction data. The evaluated photonuclear data files are created in the standard evaluated nuclear data file (ENDF) format. These files must be processed by the NJOY data processing system into A Compact ENDF (ACE) files suitable for radiation transport calculations. MCNP and MCNPX have been modified to use these new data in a self-consistent and fully integrated manner. Verification problems were used at each step along the path to check the integrity of the methodology. The resulting methodology and tools provide a comprehensive system for using photonuclear data in radiation transport calculations. Also described are initial validation simulations used to benchmark several of the photonuclear transport tables

  8. Recommended evaluation procedure for photonuclear cross section

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Ouk; Chang, Jonghwa; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In order to generate photonuclear cross section library for the necessary applications, data evaluation is combined with theoretical evaluation, since photonuclear cross sections measured cannot provide all necessary data. This report recommends a procedure consisting of four steps: (1) analysis of experimental data, (2) data evaluation, (3) theoretical evaluation and, if necessary, (4) modification of results. In the stage of analysis, data obtained by different measurements are reprocessed through the analysis of their discrepancies to a representative data set. In the data evaluation, photonuclear absorption cross sections are evaluated via giant dipole resonance and quasi-deutron mechanism. With photoabsorption cross sections from the data evaluation, theoretical evaluation is applied to determine various decay channel cross sections and emission spectra using equilibrium and preequilibrium mechanism. After this, the calculated results are compared with measured data, and in some cases the results are modified to better describe measurements. (author)

  9. Study of three nucleon mechanisms in the photodisintegration of 3 He

    International Nuclear Information System (INIS)

    Audit, G.; D'Hose, N.; Isbert, V.; Kerhoas, S.; Laget, J.M.; Mac Cormick, M.; Murphy, L.Y.; Tamas, G.; Panzeri, A.; Pinelli, T.; Ahrens, J.; Annand, J.R.M.; Crawford, R.; Hall, S.J.; Kellie, J.D.; Murphy, L.Y.

    1996-01-01

    The cross section of the 3 He (γ,pp)n reaction has been measured for the first time over a wide photon energy and proton angular range (200 MeV ≤ Eγ ≤ 800 MeV; 20 deg ≤ v lab p ≤ 160 deg) using the large acceptance detector DAPHNE at the tagged photon facility of the microtron in Mainz. The wide kinematical coverage of the measurement has allowed a detailed analysis of three nucleon absorption mechanisms. A model developed by Laget explains the main characteristics of the data in the Δ resonance region. (authors)

  10. Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction

    Science.gov (United States)

    Ciepał, I.; Kłos, B.; Stephan, E.; Kistryn, St.; Biegun, A.; Bodek, K.; Deltuva, A.; Epelbaum, E.; Eslami-Kalantari, M.; Fonseca, A. C.; Golak, J.; Jha, V.; Kalantar-Nayestanaki, N.; Kamada, H.; Khatri, G.; Kirillov, Da.; Kirillov, Di.; Kliczewski, St.; Kozela, A.; Kravcikova, M.; Machner, H.; Magiera, A.; Martinska, G.; Messchendorp, J.; Nogga, A.; Parol, W.; Ramazani-Moghaddam-Arani, A.; Roy, B. J.; Sakai, H.; Sekiguchi, K.; Sitnik, I.; Siudak, R.; Skibiński, R.; Sworst, R.; Urban, J.; Witała, H.; Zejma, J.

    2014-03-01

    One of the most important goals of modern nuclear physics is to contruct nuclear force model which properly describes the experimental data. To develop and test predictions of current models the breakup 1H(overrightarrow d, pp)n reaction was investigated experimentally at 100 and 130 MeV deuteron beam energies. Rich set of data for cross section, vector and tensor analyzing powers was obtained with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which describe the three-nucleon (3N) system dynamics. For correct description of the cross section data both, three-nucleon force (3NF) and Coulomb force, have to be included into calculations and influence of those ingredients is seizable at specific parts of the phase space. In case of the vector analyzing powers very low sensitivity to any effects beyond nucleon-nucleon interaction was found. At 130 MeV, the Axy data are not correctly described when 3NF models are included into calculations.

  11. Modern status of photonuclear data

    Science.gov (United States)

    Varlamov, V. V.; Ishkhanov, B. S.

    2017-09-01

    The reliability of experimental cross sections obtained for (γ, 1 n), (γ, 2 n), and (γ, 3 n) partial photoneutron reactions using beams of quasimonoenergetic annihilation photons and bremsstrahlung is analyzed by employing data for a large number of medium-heavy and heavy nuclei, including those of 63,65Cu, 80Se, 90,91,94Zr, 115In, 112-124Sn, 133Cs, 138Ba, 159Tb, 181Ta, 186-192Os, 197Au, 208Pb, and 209Bi. The ratios of the cross sections of definite partial reactions to the cross section of the neutron-yield reaction, F i = σ(γ, in)/ σ(γ, xn), are used as criteria of experimental-data reliability. By definition, positive values of these ratios should not exceed the upper limits of 1.00, 0.50, 0.33,... for i = 1, 2, 3,..., respectively. For many nuclei, unreliable values of the above ratios were found to correlate clearly in various photon-energy regions F i with physically forbidden negative values of cross sections of partial reactions. On this basis, one can conclude that correspondent experimental data are unreliable. Significant systematic uncertainties of the methods used to determine photoneutron multiplicity are shown to be the main reason for this. New partial-reaction cross sections that satisfy the above data-reliability criteria were evaluated within an experimental-theoretical method [ σ eval(γ, in) = F i theor (γ, in) × σ expt(γ, xn)] by employing the ratios F i theor (γ, in) calculated on the basis of a combined photonuclear-reaction model. It was obtained that cross sections evaluated in this way deviate substantially from the results of many experiments performed via neutron-multiplicity sorting, but, at the same time, agree with the results of alternative activation experiments. Prospects of employing methods that would provide, without recourse to photoneutron-multiplicity sorting, reliable data on cross sections of partial photoneutron reactions are discussed.

  12. Photonuclear experiments using large acceptance detectors

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1984-08-01

    Experimental programs in photonuclear physics are discussed. In experiments concentrate on the combined use of low intensity (real and virtual) photon beams and large acceptance detectors for the detection of multiple particle final states. Count rate estimates and the consequences for the operation of a high intensity accelerator are given. (orig.)

  13. Photonuclear studies in the few nucleon system

    International Nuclear Information System (INIS)

    Weiss, M.S.

    1975-02-01

    A brief review of photonuclear reactions in few nucleon systems is presented with comparison of theory with experiment. Discrepancies are examined and recent and current research aimed at resolving these problems are discussed. Emphasis is placed on two and three body photodisintegration. (33 figures) (U.S.)

  14. Photonuclear physics with low intensity photon beams

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1985-01-01

    Experiments in photonuclear physics are discussed that require a low intensity photon beam and large acceptance detectors. This combination is especially suitable for the investigation of photoprocesses on nucleons and light nuclei. A specific experimental setup for the electron stretcher ring ELSA is presented. (orig.)

  15. Probing the three-nucleon force using nucleon-deuteron breakup reactions

    International Nuclear Information System (INIS)

    Howell, C.R.; Lambert, J.M.; Witala, H.

    1995-01-01

    Results of our recent kinematically complete cross-section measurements of the space-star and coplanar-star configurations in n-d breakup at 13.0 MeV are reported. The experimental setup and details of the analysis are described. The new data for the space-star configuration are in good agreement with previous n-d data but differ significantly from both ''exact'' n-d calculations and p-d data. In contrast, the new coplanar-star data are in fair agreement with the calculations but are in gross disagreement with previous n-d data. The implications of these data for three-nucleon forces are discussed. (orig.)

  16. Probing the three-nucleon force using nucleon-deuteron breakup reactions

    Energy Technology Data Exchange (ETDEWEB)

    Howell, C.R. [Duke Univ., Durham, NC (United States). Dept. of Physics; Setze, H.R. [Duke Univ., Durham, NC (United States). Dept. of Physics; Braun, R.T. [Duke Univ., Durham, NC (United States). Dept. of Physics; Gonzalez Trotter, D.E. [Duke Univ., Durham, NC (United States). Dept. of Physics; Hussein, A.H. [Duke Univ., Durham, NC (United States). Dept. of Physics; Roper, C.D. [Duke Univ., Durham, NC (United States). Dept. of Physics; Salinas, F. [Duke Univ., Durham, NC (United States). Dept. of Physics; Slaus, I. [Duke Univ., Durham, NC (United States). Dept. of Physics; Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics; Vlahovic, B. [Duke Univ., Durham, NC (United States). Dept. of Physics; Walter, R.L. [Duke Univ., Durham, NC (United States). Dept. of Physics; Mertens, G. [Tuebingen Univ. (Germany); Lambert, J.M. [Department of Physics, Georgetown University, Washington, DC 20057 (United States); Witala, H. [Institute of Physics, Jagellonian University, Reymonta 4, PL-30059 Cracow (Poland)

    1995-05-01

    Results of our recent kinematically complete cross-section measurements of the space-star and coplanar-star configurations in n-d breakup at 13.0 MeV are reported. The experimental setup and details of the analysis are described. The new data for the space-star configuration are in good agreement with previous n-d data but differ significantly from both ``exact`` n-d calculations and p-d data. In contrast, the new coplanar-star data are in fair agreement with the calculations but are in gross disagreement with previous n-d data. The implications of these data for three-nucleon forces are discussed. (orig.).

  17. The effect of including tensor forces in nucleon-nucleon interaction on three-nucleon binding energy

    International Nuclear Information System (INIS)

    Osman, A.; Ramadan, S.

    1986-01-01

    Separable two-body interactions are used in considering the three-nucleon problem. The nucleon-nucleon potentials are taken to include attraction and repulsion as well as tensor forces. The separable approximation is used in order to investigate the effect of the tensor forces. The separable expansion is introduced in the three-nucleon problem, by which the Faddeev equations are reduced to a well-behaved set of coupled integral equations. Numerical calculations are carried out for the obtained integral equations using potential functions of the Yamaguchi, Gaussian, Takabin, Mongan and Reid forms. The present calculated values of the binding energies of the 3 H and 3 He nuclei are in good agreement with the experimental values. The effect of including the tensor forces in the nucleon-nucleon interactions is found to improve the three-nucleon binding energy by about 4.490% to 8.324%. 37 refs., 2 tabs. (author)

  18. Photonuclear data index 1986-1990

    Energy Technology Data Exchange (ETDEWEB)

    Varlamov, V A; Stepanov, M E; Sapunenko, V V [Moscow State University, Institute of Nuclear Physics, Centre for Photonuclear Experimental Data, Moscow (Russian Federation)

    1992-07-01

    This issue presents a bibliographic index to experimental photonuclear data published in periodical scientific literature during the years 1986-1990. The main tabulation is sorted by nucleus and reaction. It is supplemented by a reference index, an author index, explanatory tables of terms and abbreviations used, and a table of isotopic abundances and nucleon separation energies. The index is in English with an introduction in Russian and English. (author)

  19. Few-Nucleon Research at TUNL: Probing Two- and Three-Nucleon Interactions with Neutrons

    Science.gov (United States)

    Howell, C. R.; Tornow, W.; Witała, H.

    2016-03-01

    The central goal of few-nucleon research at the Triangle Universities Nuclear Laboratory (TUNL) is to perform measurements that contribute to advancing ab-initio calculations of nuclear structure and reactions. The program aims include evaluating theoretical treatments of few-nucleon reaction dynamics through strategically comparing theory predictions to data, determining properties of the neutron-neutron interaction that are not accessible in two-nucleon reactions, and searching for evidence of longrange features of three-nucleon interactions, e.g., spin and isospin dependence. This paper will review studies of three- and four-nucleon systems at TUNL conducted using unpolarized and polarized neutron beams. Measurements of neutron-induced reactions performed by groups at TUNL over the last six years are described in comparison with theory predictions. The results are discussed in the context of the program goals stated above. Measurements of vector analyzing powers for elastic scattering in A=3 and A=4 systems, differential cross sections for neutron-deuteron elastic scattering and neutrondeuteron breakup in several final-state configurations are described. The findings from these studies and plans for the coming three years are presented in the context of worldwide activities in this front, in particular, research presented in this session.

  20. Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, Hugo F. [University of Chile, Department of Physics - FCFM, Santiago (Chile); CEA, DAM, DIF, Arpajon (France); Isaule, Felipe [University of Chile, Department of Physics - FCFM, Santiago (Chile); Rios, Arnau [University of Surrey, Department of Physics, Faculty of Engineering and Physical Sciences, Guildford (United Kingdom)

    2016-09-15

    We investigate homogeneous nuclear matter within the Brueckner-Hartree-Fock (BHF) approach in the limits of isospin-symmetric nuclear matter (SNM) as well as pure neutron matter at zero temperature. The study is based on realistic representations of the internucleon interaction as given by Argonne v{sub 18}, Paris, Nijmegen I and II potentials, in addition to chiral N{sup 3}LO interactions, including three-nucleon forces up to N{sup 2}LO. Particular attention is paid to the presence of di-nucleon bound states structures in {sup 1}S{sub 0} and {sup 3}SD{sub 1} channels, whose explicit account becomes crucial for the stability of self-consistent solutions at low densities. A characterization of these solutions and associated bound states is discussed. We confirm that coexisting BHF single-particle solutions in SNM, at Fermi momenta in the range 0.13-0.3 fm{sup -1}, is a robust feature under the choice of realistic internucleon potentials. (orig.)

  1. Few-Nucleon Research at TUNL: Probing Two- and Three-Nucleon Interactions with Neutrons

    Directory of Open Access Journals (Sweden)

    Howell C.R.

    2016-01-01

    Full Text Available The central goal of few-nucleon research at the Triangle Universities Nuclear Laboratory (TUNL is to perform measurements that contribute to advancing ab-initio calculations of nuclear structure and reactions. The program aims include evaluating theoretical treatments of few-nucleon reaction dynamics through strategically comparing theory predictions to data, determining properties of the neutron-neutron interaction that are not accessible in two-nucleon reactions, and searching for evidence of longrange features of three-nucleon interactions, e.g., spin and isospin dependence. This paper will review studies of three- and four-nucleon systems at TUNL conducted using unpolarized and polarized neutron beams. Measurements of neutron-induced reactions performed by groups at TUNL over the last six years are described in comparison with theory predictions. The results are discussed in the context of the program goals stated above. Measurements of vector analyzing powers for elastic scattering in A=3 and A=4 systems, differential cross sections for neutron-deuteron elastic scattering and neutrondeuteron breakup in several final-state configurations are described. The findings from these studies and plans for the coming three years are presented in the context of worldwide activities in this front, in particular, research presented in this session.

  2. Updated Photonuclear Data Library and Database for Photon Strength Functions

    Directory of Open Access Journals (Sweden)

    Dimitriou Paraskevi

    2015-01-01

    Full Text Available Photonuclear cross sections and gamma-ray data used to extract Photon Strength Functions are important for a large range of applications including basic sciences. The recommendations of an IAEA Consultant’s Meeting to update the IAEA Photonuclear Data Library and create a Reference Database for Photon Strength Functions are presented.

  3. Laser induced photonuclear and fusion-reactions

    International Nuclear Information System (INIS)

    LoDato, V.A.

    1977-01-01

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

  4. Studies of the three-nucleon system dynamics : Cross sections of the deuteron-proton breakup at 130 MeV

    NARCIS (Netherlands)

    Kistryn, St.; Stephan, E.; Kalantar-Nayestanaki, N.; Biegun, A.; Bodek, K.; Ciepal, I.; Deltuva, A.; Epelbaum, E.; Fonseca, A. C.; Gloeckle, W.; Golak, J.; Kamada, H.; Kis, M.; Klos, B.; Kozela, A.; Nogga, A.; Mahjour-Shafiei, M.; Micherdzinska, A.; Sauer, P. U.; Skibinski, R.; Sworst, R.; Witala, H.; Zejma, J.; Zipper, W.

    2008-01-01

    The three-nucleon system is the simplest non-trivial testing ground in which the quality of modern nucleon-nucleon interaction models, as well as additional dynamical ingredients referred to as three-nucleon forces, can be probed quantitatively by means of a rigorous technique of solving the Faddeev

  5. Three-nucleon force contribution in the distorted-wave theory of (d ,p ) reactions

    Science.gov (United States)

    Timofeyuk, N. K.

    2018-05-01

    The distorted-wave theory of A (d ,p )B reactions, widely used to analyze experimental data, is based on a Hamiltonian that includes only two-nucleon interactions. However, numerous studies of few-nucleon systems and many modern developments in nuclear structure theory show the importance of the three-nucleon (3 N ) force. The purpose of this paper is to study the contribution of the 3 N force of the simplest possible form to the A (d ,p )B reaction amplitude. This contribution is given by a new term that accounts for the interaction of the neutron and proton in the incoming deuteron with one of the target nucleons. This term involves a new type of nuclear matrix elements containing an infinite number of target excitations in addition to the main part associated with the traditional overlap function between A and B . The nuclear matrix elements are calculated for double-closed shell targets within a mean field theory where target excitations are shown to be equivalent to exchanges between valence and core nucleons. These matrix elements can be readily incorporated into available reaction codes if the 3 N interaction has a spin-independent zero-range form. Distorted-wave calculations are presented for a contact 3 N force with the volume integral fixed by the chiral effective field theory at the next-to-next-to-leading order. For this particular choice, the 3 N contribution is noticeable, especially at high deuteron incident energies. No 3 N effects are seen for incident energies below the Coulomb barrier. The finite range can significantly affect the 3 N contribution to the (d ,p ) cross sections. Finite-range studies require new formal developments and, therefore, their contribution is preliminarily assessed within the plane-wave Born approximation, together with sensitivity to the choice of the deuteron model.

  6. Three-nucleon transfer reactions and cluster structure in the A = 15 to A = 19 nuclei

    International Nuclear Information System (INIS)

    Martz, L.M.

    1978-01-01

    The ( 6 Li,t) and ( 6 Li, 3 He) reactions were studied on targets of 12 C, 13 C, 14 N, 15 N, and 16 O at E/sub Li/ approx. = 44 MeV and theta/sub lab/ approx. = 15 0 . A preferential population of final states was exhibited in spectra for the A = 15 to A = 19 nuclei. The strong forward peaking of angular distributions in the 13 C( 6 Li,t) 16 O and 13 C( 6 Li, 3 He) 16 N reactions can be reproduced by DWBA calculations but not by the Hauser-Feshbach model. Such indications of a primarily direct mechanism at forward angles suggest use of these three-nucleon-transfer reactions to identify candidates for 3p-nh states. A comparison with other multinucleon transfer data, e.g., those from ( 7 Li,α) and ( 7 Li,t) reactions on 13 C and 15 N targets, further tests dominant particle-hole configurations. The relationship between ( 6 Li,t) and ( 6 Li, 3 He) spectra reveals analog states, notably T = 1, T/sub z/ = 0 levels at high excitation in 16 O. Nuclear theory is used to investigate the role of triton clustering in such structure. The 2N + L = 6 band predicted by a folded-potential model of 18 O = 15 N + t shows an underlying correspondence to the experimental levels in triton-transfer data. Triton spectroscopic factors calculated from the SU(3) shell model further suggest the broad influence of clustering phenomena in this mass region. Experimental evidence of systematic behavior in the triton binding energies of proposed p/sup -n/(sd) 3 configurations was found

  7. Bibliographic index to photonuclear reaction data

    International Nuclear Information System (INIS)

    Asami, Tetsuo; Nakagawa, Tsuneo.

    1993-10-01

    This report contains the bibliographic index data on photonuclear reactions and on their inverse ones, in the format similar to CINDA for neutron nuclear data. As photonuclear reactions the electron-induced reaction data are also included. As the inverse reactions considered are those induced by neutron, proton, deuteron, triton, helion and alpha particles. The index covers major journals on nuclear data published in 1995 to 1992, for all nuclides through hydrogen (H) to einsteinium (Es). The bibliographic index contains information on target nucleus, incident beam, type of reaction and quantity, energy range of incident beam, laboratory, type of work, reference citations, first author's name, and short comment. The index also contains the indication for information on cross-section data. All the index data are listed in the order of target element, target, mass and incident particle, and in the chronological order of reference data. Also a brief description is given on the data format, the abbreviations used and the journals surveyed. (author)

  8. Measurements of the n->d scattering at 250 MeV and three-nucleon forces

    International Nuclear Information System (INIS)

    Maeda, Y.; Sakai, H.; Fujita, K.; Hatano, M.; Kamiya, J.; Kawabata, T.; Kuboki, H.; Hatanaka, K.; Okamura, H.; Saito, T.; Sakemi, Y.; Sasano, M.; Sekiguchi, K.; Shimizu, Y.; Suda, K.; Tameshige, Y.; Tamii, A.; Wakasa, T.; Yako, K.; Greenfield, M.B.; Kamada, H.; Witala, H.

    2007-01-01

    The differential cross sections and the vector analyzing powers for the nd elastic scattering at E n = 250 MeV have been measured for the study of the three-nucleon force (3NF) effects in the Coulomb-free system. To cover a wide angular region, the experiments were performed by using two different methods at the (n, p) facility and at the NTOF facility which constructed at the Research Center for Nuclear Physics (RCNP). The results were compared with theoretical predictions of the Faddeev calculations based on the modern nucleon-nucleon (NN) forces with the three-nucleon force (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions with relativistic corrections. The direct data-to-data comparison of the cross sections of the nd and pd was performed

  9. Complete Set of Deuteron Analyzing Powers for dp Elastic Scattering at 250 MeV/nucleon and Three Nucleon Forces

    Directory of Open Access Journals (Sweden)

    Shimizu Y.

    2010-04-01

    Full Text Available Measurements of a complete set of deuteron analyzing powers (iT11, T20, T21, T22 for elastic deuteron–proton scattering at 250 MeV/nucleon have been performed with polarized deuteron beams at RIKEN RI Beam Factory. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne’99, and UrbanaIX three nucleon forces.

  10. Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain

    Science.gov (United States)

    Cipollone, A.; Barbieri, C.; Navrátil, P.

    2015-07-01

    Background: Three-nucleon forces (3NFs) have nontrivial implications on the evolution of correlations at extreme proton-neutron asymmetries. Recent ab initio calculations show that leading-order chiral interactions are crucial to obtain the correct binding energies and neutron driplines along the O, N, and F chains [A. Cipollone, C. Barbieri, and P. Navrátil, Phys. Rev. Lett. 111, 062501 (2013), 10.1103/PhysRevLett.111.062501]. Purpose: Here we discuss the impact of 3NFs along the oxygen chain for other quantities of interest, such has the spectral distribution for attachment and removal of a nucleon, spectroscopic factors, and radii. The objective is to better delineate the general effects of 3NFs on nuclear correlations. Methods: We employ self-consistent Green's function (SCGF) theory which allows a comprehensive calculation of the single-particle spectral function. For the closed subshell isotopes, 14O, 16O, 22O, 24O, and 28O, we perform calculations with the Dyson-ADC(3) method, which is fully nonperturbative and is the state of the art for both nuclear physics and quantum chemistry applications. The remaining open-shell isotopes are studied using the newly developed Gorkov-SCGF formalism up to second order. Results: We produce complete plots for the spectral distributions. The spectroscopic factors for the dominant quasiparticle peaks are found to depend very little on the leading-order (NNLO) chiral 3NFs. The latter have small impact on the calculated matter radii, which, however, are consistently obtained smaller than experiment. Similarly, single-particle spectra tend to be too spread with respect to the experiment. This effect might hinder, to some extent, the onset of correlations and screen the quenching of calculated spectroscopic factors. The most important effect of 3NFs is thus the fine tuning of the energies for the dominant quasiparticle states, which governs the shell evolution and the position of driplines. Conclusions: Although present chiral

  11. Low energy supersymmetry phenomenology

    International Nuclear Information System (INIS)

    Baer, H.; Chen, C.H.; Gunion, J.; Kamon, T.; Lopez, J.L.; Kao, C.

    1995-04-01

    The authors summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, they evaluate the capabilities of various e + e - , p bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, they discuss capabilities of future facilities to disentangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. The authors then comment upon the complementarity of proposed hadron and e + e - machines for a comprehensive study of low energy supersymmetry

  12. Low energy supersymmetry phenomenology

    CERN Document Server

    Baer, H.; Chen, C.H.; Eberl, H.; Feng, J.L.; Fujii, K.; Gunion, John F.; Kamon, T.; Kao, C.; Lopez, J.L.; Majerotto, W.; McIntyre, P.; Munroe, Ray B.; Murayama, H.; Paige, F.; Porod, W.; Sender, J.; Sopczak, A.; Tata, X.; Tsukamoto, T.; White, J.

    1996-01-01

    We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various e^+e^-, p\\bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and e^+e^- machines for a comprehensive study of low energy supersymmetry.

  13. The NIRA computer program package (photonuclear data center). Final report

    International Nuclear Information System (INIS)

    Vander Molen, H.J.; Gerstenberg, H.M.

    1976-02-01

    The Photonuclear Data Center's NIRA library of programs, executable from mass storage on the National Bureau of Standard's central computer facility, is described. Detailed instructions are given (with examples) for the use of the library to analyze, evaluate, synthesize, and produce for publication camera-ready tabular and graphical presentations of digital photonuclear reaction cross-section data. NIRA is the acronym for Nuclear Information Research Associate

  14. Bibliographic index to photonuclear reaction data (1955--1992)

    Energy Technology Data Exchange (ETDEWEB)

    Asami, Tetsuo [Data Engineering, Inc., Yokohama (Japan); Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Dept. of Reactor Engineering

    1993-10-01

    Japanese Nuclear Data Committee (JNDC) has a plan to compile the evaluated data library for photon-induced nuclear reaction cross sections, and the work on the data evaluation is in progress at the present. In the evaluations for these data a bibliographic index for neutron nuclear data is required. As the bibliographic index to photonuclear reactions, several excellent compilations have been done at some research institutes in the world, and have contributed to various basic and applied researches on the photonuclear reactions. For example, there are the abstract sheets published by US National Bureau of Standards and the data index published regularly in Russia. On the other hand, the four-center network on nuclear data (US National Nuclear Data Center at Brookhaven, Russian Nuclear Data Center at Obninsk, NEA Data Bank at Paris and IAEA Nuclear Data Section at Vienna) compiles and exchanges the numerical data on photonuclear reactions as well as on neutron-induced ones, in the EXFOR format. Those numerical data are available for users. There is, however, no bibliographic index to photonuclear reactions, available for general users. Therefore, the present work to make a photonuclear reaction data index has been done urgently to contribute to the above-mentioned data evaluation. Although these data might be still incomplete and have some defects, we have decided to serve this as the first edition of our photonuclear reaction index.

  15. Uncertainties in constraining low-energy constants from {sup 3}H β decay

    Energy Technology Data Exchange (ETDEWEB)

    Klos, P.; Carbone, A.; Hebeler, K. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Menendez, J. [University of Tokyo, Department of Physics, Tokyo (Japan); Schwenk, A. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2017-08-15

    We discuss the uncertainties in constraining low-energy constants of chiral effective field theory from {sup 3}H β decay. The half-life is very precisely known, so that the Gamow-Teller matrix element has been used to fit the coupling c{sub D} of the axial-vector current to a short-range two-nucleon pair. Because the same coupling also describes the leading one-pion-exchange three-nucleon force, this in principle provides a very constraining fit, uncorrelated with the {sup 3}H binding energy fit used to constrain another low-energy coupling in three-nucleon forces. However, so far such {sup 3}H half-life fits have only been performed at a fixed cutoff value. We show that the cutoff dependence due to the regulators in the axial-vector two-body current can significantly affect the Gamow-Teller matrix elements and consequently also the extracted values for the c{sub D} coupling constant. The degree of the cutoff dependence is correlated with the softness of the employed NN interaction. As a result, present three-nucleon forces based on a fit to {sup 3}H β decay underestimate the uncertainty in c{sub D}. We explore a range of c{sub D} values that is compatible within cutoff variation with the experimental {sup 3}H half-life and estimate the resulting uncertainties for many-body systems by performing calculations of symmetric nuclear matter. (orig.)

  16. Low-energy QCD

    International Nuclear Information System (INIS)

    Ecker, G.

    1995-11-01

    After a brief introduction to chiral perturbation theory, the effective field theory of the standard model at low energies, two recent applications are reviewed: elastic pion-pion scattering to two-loop accuracy and the complete renormalized pion-nucleon Lagrangian to O(P 3 ) in the chiral expansion. (author)

  17. The effect of higher order different meson exchange nucleon-nucleon interactions on the three-nucleon binding energy coupling problem

    International Nuclear Information System (INIS)

    Osman, A.; Ramadan, S.

    1989-01-01

    Faddeev equations of bound three-nucleon system are presented as a set of integral equations. To solve them, a sutable form of the nucleon-nucleon interactions is used: with the exchange of a scalar meson, a pseudoscalar meson and a massless vector meson. Higher orders of these different meson exchanges in the nucleon-nucleon interactions have been taken into account. With these nuclear forces and nucleon-nucleon interactions, the three-nucleon binding energy is calculated by solving the Faddeev integral equations. The obtained value of the three-nucleon binding energy is 8.441 MeV. The inclusion of the higher order terms of the different meson exchange in the nuclear nucleon-nucleon interaction is found to affect the three-nucleon binding by about 3.92%. 3 figs., 16 refs

  18. Weak interaction in a three nucleon system: search for an asymmetry in radiative capture n-d

    International Nuclear Information System (INIS)

    Avenier, M.

    1982-01-01

    Experimental determination of the weak interaction rate in a three nucleon neutron-deuteron system: this weak interaction is observed through pseudoscalar parameters such as the asymetric angular distribution of the capture photon in relation with the system polarization. Orientation of the system is achieved by use of a polarized cold neutron beam. This phenomena is explained as a result of weak coupling between nucleons and mesons. Measurements of the gamma asymmetries observed when tests are conducted with or without heavy water and effects of depolarization are discussed [fr

  19. Symbolic computation of the Hartree-Fock energy from a chiral EFT three-nucleon interaction at N2LO

    International Nuclear Information System (INIS)

    Gebremariam, B.; Bogner, S.K.; Duguet, T.

    2010-01-01

    We present the first of a two-part Mathematica notebook collection that implements a symbolic approach for the application of the density matrix expansion (DME) to the Hartree-Fock (HF) energy from a chiral effective field theory (EFT) three-nucleon interaction at N 2 LO. The final output from the notebooks is a Skyrme-like energy density functional that provides a quasi-local approximation to the non-local HF energy. In this paper, we discuss the derivation of the HF energy and its simplification in terms of the scalar/vector-isoscalar/isovector parts of the one-body density matrix. Furthermore, a set of steps is described and illustrated on how to extend the approach to other three-nucleon interactions. Program summary: Program title: SymbHFNNN; Catalogue identifier: AEGC v 1 0 ; Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEGC_v1_0.html; Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland; Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html; No. of lines in distributed program, including test data, etc.: 96 666; No. of bytes in distributed program, including test data, etc.: 378 083; Distribution format: tar.gz; Programming language: Mathematica 7.1; Computer: Any computer running Mathematica 6.0 and later versions; Operating system: Windows Xp, Linux/Unix; RAM: 256 Mb; Classification: 5, 17.16, 17.22; Nature of problem: The calculation of the HF energy from the chiral EFT three-nucleon interaction at N 2 LO involves tremendous spin-isospin algebra. The problem is compounded by the need to eventually obtain a quasi-local approximation to the HF energy, which requires the HF energy to be expressed in terms of scalar/vector-isoscalar/isovector parts of the one-body density matrix. The Mathematica notebooks discussed in this paper solve the latter issue. Solution method: The HF energy from the chiral EFT three-nucleon interaction at N 2 LO is cast into a form suitable for an automatic

  20. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  1. Unified description of ^{6}Li structure and deuterium-^{4}He dynamics with chiral two- and three-nucleon forces.

    Science.gov (United States)

    Hupin, Guillaume; Quaglioni, Sofia; Navrátil, Petr

    2015-05-29

    We provide a unified ab initio description of the ^{6}Li ground state and elastic scattering of deuterium (d) on ^{4}He (α) using two- and three-nucleon forces from chiral effective field theory. We analyze the influence of the three-nucleon force and reveal the role of continuum degrees of freedom in shaping the low-lying spectrum of ^{6}Li. The calculation reproduces the empirical binding energy of ^{6}Li, yielding an asymptotic D- to S-state ratio of the ^{6}Li wave function in the d+α configuration of -0.027, in agreement with a determination from ^{6}Li-^{4}He elastic scattering, but overestimates the excitation energy of the 3^{+} state by 350 keV. The bulk of the computed differential cross section is in good agreement with data. These results endorse the application of the present approach to the evaluation of the ^{2}H(α,γ)^{6}Li radiative capture, responsible for the big-bang nucleosynthesis of ^{6}Li.

  2. Low Energy Conference 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    11 of the 19 presentations have been indexed for the database. The following national organisations jointly organised the Low-energy Conference 2009: The Norwegian Society for the Conservation of Nature, the Norwegian Society of Engineers and Technologists, Norwegian Technology, the Federation of Norwegian Industries and the Low-Energy Program. Energy efficiency is often given little attention in the ongoing debates concerning different initiatives in order to reduce greenhouse emissions. The aim of the conference was to set energy efficiency on the agenda as an important environmental instrument. Both the Intergovernmental Panel on Climate Change - IPCC and the International Energy Agency - IEA regard energy efficiency as one of the fastest and most effective ways of reducing greenhouse emissions. Despite of this little is done. Many countries are ahead of Norway - why are we lagging behind? The Low-Energy conference has a broad approach: Nigel Jollands from the International Energy Agency -IEA puts energy efficiency in a global perspective. Soeren Rise from Teqniq in Denmark informs about the Danes' energy saving agreement, which appears to have been a success. The conference increased the competencies on concrete energy efficiency solutions, how to speed up the marketing of energy-friendly buildings and technologies, possibilities through industry and the impact of EU-directives and other instruments in order to trigger the potential. The conference closed with a discussion panel of leading energy politicians. The conference contributed to raise the debate in advance of the General election in Norway and the climate negotiations in Copenhagen during the autumn 2009. (EW)

  3. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  4. Extra Low ENergy Antiproton

    CERN Multimedia

    To produce dense antiproton beams at very low energies (110 keV), it has been proposed to install a small decelerator ring between the existing AD ring and the experimental area. Phase-space blowup during deceleration is compensated by electron cooling such that the final emittances are comparable to the 5MeV beam presently delivered by the AD. An immediate consequence is a significant increase in the number of trapped antiprotons at the experiments as outlined in the proposal CERN/SPSC-2009-026; SPCS-P-338. This report describes the machine parameters and layout of the proposal ELENA (Extra Low ENergy Antiproton)ring also gives an approximate estimate of cost and manpower needs. Since the initial estimate, published in 2007 (CERN-AB-2007-079), the ELENA design has evolved considerably. This is due to a new location in the AD hall to acommodate for the possibility of another experimental zone, as suggested by the SPCS, and also due to improvements in the ring optics and layout. The cost estimate that is prese...

  5. Photonuclear reactions triggered by lightning discharge.

    Science.gov (United States)

    Enoto, Teruaki; Wada, Yuuki; Furuta, Yoshihiro; Nakazawa, Kazuhiro; Yuasa, Takayuki; Okuda, Kazufumi; Makishima, Kazuo; Sato, Mitsuteru; Sato, Yousuke; Nakano, Toshio; Umemoto, Daigo; Tsuchiya, Harufumi

    2017-11-22

    Lightning and thunderclouds are natural particle accelerators. Avalanches of relativistic runaway electrons, which develop in electric fields within thunderclouds, emit bremsstrahlung γ-rays. These γ-rays have been detected by ground-based observatories, by airborne detectors and as terrestrial γ-ray flashes from space. The energy of the γ-rays is sufficiently high that they can trigger atmospheric photonuclear reactions that produce neutrons and eventually positrons via β + decay of the unstable radioactive isotopes, most notably 13 N, which is generated via 14 N + γ →  13 N + n, where γ denotes a photon and n a neutron. However, this reaction has hitherto not been observed conclusively, despite increasing observational evidence of neutrons and positrons that are presumably derived from such reactions. Here we report ground-based observations of neutron and positron signals after lightning. During a thunderstorm on 6 February 2017 in Japan, a γ-ray flash with a duration of less than one millisecond was detected at our monitoring sites 0.5-1.7 kilometres away from the lightning. The subsequent γ-ray afterglow subsided quickly, with an exponential decay constant of 40-60 milliseconds, and was followed by prolonged line emission at about 0.511 megaelectronvolts, which lasted for a minute. The observed decay timescale and spectral cutoff at about 10 megaelectronvolts of the γ-ray afterglow are well explained by de-excitation γ-rays from nuclei excited by neutron capture. The centre energy of the prolonged line emission corresponds to electron-positron annihilation, providing conclusive evidence of positrons being produced after the lightning.

  6. Three-body forces in nuclear matter from intermediate Δ-states in three-nucleon clusters

    International Nuclear Information System (INIS)

    Kouki, T.; Smulter, L.E.W.; Green, A.M.

    1976-10-01

    The three-body force contribution in nuclear matter is treated as a three-nucleon cluster, in which one of the nucleons becomes, in an intermediate state, a Δ(1236). All exchange diagrams are calculated and found to significantly reduce the energy per particle from the direct graph. This is contrary to earlier estimates of the exchanges, using more approximate approaches. The resulting attractive contribution is rather small, -1.1 MeV at ksub(F)=1.4 fm -1 , but the roughly linear density dependence has a crucial effect on the saturation properties. The sensitivity of the results to the correlations used, and to the two-body force spin structure, is displayed. The energy per particle from clusters with three intermediate Δ's is also estimated. (author)

  7. Δ effects in pion-nucleon scattering and the strength of the two-pion-exchange three-nucleon interaction

    International Nuclear Information System (INIS)

    Pandharipande, V.R.; Phillips, D.R.; Kolck, U. van

    2005-01-01

    We consider the relationship between p-wave πN scattering and the strength of the p-wave two-pion-exchange three-nucleon interaction (TPE3NI). We explain why effective theories that do not contain the Delta resonance as an explicit degree of freedom tend to overestimate the strength of the TPE3NI. The overestimation can be remedied by higher-order terms in these 'Delta-less' theories, but such terms are not yet included in state-of-the-art chiral effective field theory calculations of the nuclear force. This suggests that these calculations can predict the strength of the TPE3NI only to an accuracy of ±25%

  8. Inside bluetooth low energy

    CERN Document Server

    Gupta, Naresh

    2013-01-01

    Bluetooth Low Energy (LE) is one of the latest enhancement to Bluetooth technology and, as the name suggests, it is aimed at ultra low power devices, such as heart rate monitors, thermometers, and sensors. Due to very low power consumption, devices compliant with this standard can operate for several years on coin cell batteries without the need for recharging. This cutting-edge book helps you understand the whats , whys , and hows of Bluetooth LE. It includes a broad view of the technology, identifies the various building blocks, and explains how they come together. You also find discussions on Bluetooth basics, providing the background information needed to master Bluetooth LE.The book explains the architecture of Bluetooth LE stack and the functionality provided by each of the layers. You find expert guidance in setting up your own system in a quick and efficient manner with inexpensive, easily available hardware and just a couple of PCs running Linux. This unique volume features two chapters that are dedi...

  9. Solar low energy dwellings

    International Nuclear Information System (INIS)

    Hestnes, Anne Grete

    2000-01-01

    By now, a lot has been learnt about how to reduce energy use in dwellings using solar and low energy technologies, and many good examples can be found throughout Europe. Still, they are not quite the common feature we would expect them to be, i.e. they have not really penetrated the market. The reason for this is in part a result of the fact that the designers and developers of these buildings have not looked at what the market wants and needs, but rather at how to use a set of given technologies. The buildings are the result of a technology push rather than a market pull and have therefore, often, been detached or semidetached dwellings with different solar technologies added on in less than optimal ways. In order to increase market penetration, it is time to look at the market trends and relate to these. Fortunately, quite a few European architects have realized this and have started designing somewhat different residential buildings. The paper focuses on examples of the new trends in solar residential architecture and by that, hopefully, it shows that we are on the right track. (au)

  10. Very low energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

  11. The Saskatchewan-Alberta large acceptance detector for photonuclear physics

    Science.gov (United States)

    Cairns, E. B.; Cameron, J.; Choi, W. C.; Fielding, H. W.; Green, P. W.; Greeniaus, L. G.; Hackett, E. D.; Holm, L.; Kolb, N. R.; Korkmaz, E.; Langill, P. P.; McDonald, W. J.; Mack, D.; Olsen, W. C.; Peterson, B. A.; Rodning, N. L.; Soukup, J.; Zhu, J.; Hutcheon, D.; Caplan, H. S.; Pywell, R. E.; Skopik, D. M.; Vogt, J. M.; van Heerden, I. J.

    1992-09-01

    The Saskatchewan-Alberta Large Acceptance Detector (SALAD) is a 4 π detector designed and built for studies of photonuclear reactions with a tagged photon beam. The design and performance of the detector are described. Its characteristics have been studied by examining p-p elastic scattering with a proton beam at TRIUMF.

  12. Cross Sections of the Deuteron-Proton Breakup at 130 MeV : A Probe of Three-Nucleon System Dynamics

    NARCIS (Netherlands)

    Kistryn, St.; Stephan, E.; Kalantar-Nayestanaki, N.; Biegun, A.; Bodek, K.; Ciepal, I.; Deltuva, A.; Eslami-Kalantari, M.; Fonseca, A. C.; Kis, M.; Klos, B.; Kozela, A.; Mahjour-Shafiei, M.; Messchendorp, J.; Micherdzinska, A.; Parol, W.; Ramazani-Moghaddam-Arani, A.; Sworst, R.; Zejma, J.

    Three-nucleon system dynamics can be investigated quantitatively by comparing observables calculated with the use of Faddeev equations with results of precise measurements. Proper description of the experimental data can be achieved only if the dynamical models include, in addition to the

  13. /sup 58,60,62/Ni (. cap alpha. ,p) three--nucleon transfer reactions and. cap alpha. optical potential ambiguities

    Energy Technology Data Exchange (ETDEWEB)

    Yuanda, Wang; Xiuming, Bao; Zhiqiang, Mao; Rongfang, Yuan; Keling, Wen; Binyin, Huang; Zhifu, Wang; Shuming, Li; Jianan, Wang; Zuxun, Sun; others, and

    1985-11-01

    The differential cross sections are measured using 26.0 MeV ..cap alpha.. particle for /sup 58,62/Ni(..cap alpha.., ..cap alpha..) /sup 58,62/Ni and /sup 58,62/Ni(..cap alpha..,p) /sup 61,65/Cu reactions as well as 25.4 MeV ..cap alpha.. particle for /sup 60/Ni(..cap alpha.., ..cap alpha..)/sup 69/Ni and /sup 60/Ni(..cap alpha.., p)/sup 63/Cu reactions. Consistent calculations with optical model and ZR DWBA are made for (..cap alpha.., ..cap alpha..) and (..cap alpha.., p) reactions by using of single, two, three and four nucleon optical potential parameters. For elastic scattering due to the ..cap alpha.. optical potential ambiguities, all the above optical potential can reproduce the experimental angular distributions. However, the single, two and three nucleon potential, including the Baird's mass systematics and the Chang's energy systematics of ..cap alpha.. potentials, obviously can not provide a reasonable fitting with the (..cap alpha..,p) reaction experimental data. Only the results from the four nucleon potential is in good agreement with the (..cap alpha..,p) reaction experimental data. This reveals that in the ..cap alpha..-particle induced transfer reactions, the real depth of the ..cap alpha..-nucleus optical potential should be rather deep.

  14. Three-body dynamics in one dimension: a test model for the three-nucleon system with irreducible pionic diagrams

    International Nuclear Information System (INIS)

    Melde, T.; Canton, L.; Svenne, J.P.

    2002-01-01

    We formulate the three-body problem in one dimension in terms of the (Faddeev-type) integral equation approach. As an application, we develop a spinless, one-dimensional (1-D) model that mimics three-nucleon dynamics in one dimension. Using simple two-body potentials that reproduce the deuteron binding, we obtain that the three-body system binds at about 7.5 MeV. We then consider two types of residual pionic corrections in the dynamical equation; one related to the 2π-exchange three-body diagram, the other to the 1π-exchange three-body diagram. We find that the first contribution can produce an additional binding effect of about 0.9 MeV. The second term produces smaller binding effects, which are, however, dependent on the uncertainty in the off-shell extrapolation of the two-body t-matrix. This presents interesting analogies with what occurs in three dimensions. The paper also discusses the general three-particle quantum scattering problem, for motion restricted to the fall line. (author)

  15. Nucleosynthesis of heavy elements by the photonuclear reaction

    International Nuclear Information System (INIS)

    Hayakawa, Takehito

    2002-01-01

    Nucleosynthesis of heavy elements is important for understanding of the site mechanism in the stellar and cosmochronology. The nuclei heavier than iron have been synthesized mainly by the s-process and the β-decay after the r-process. The light isotope p-nuclei produced by the photonuclear reaction in Type II supernovae explosions. In order to understand the role of each process, the ratios of the processes are calculated. I propose the experimental plan using the photon sources. (author)

  16. Application of a Betatron in Photonuclear Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D [AB Atomenergi, Nykoeping (Sweden); Mattsson, K; Liden, K [Dept . of Radiation Physics, Univ. of Lund (Sweden)

    1968-08-15

    The present study concerns the determination of fluorine, iodine, lead and mercury by means of photonuclear activation technique using a betatron. The detection limit obtained for the elements in the above given sequence amounted to 3, 50, 400 and 15 {mu}g respectively. The technique has been applied in the determination of iodine in pharmaceuticals. A rotating sample holder device was inserted in the Bremsstrahlung beam of the betatron in order to ensure uniform irradiation of the samples.

  17. Effects of chiral three-nucleon forces on 4He-nucleus scattering in a wide range of incident energies

    Science.gov (United States)

    Toyokawa, Masakazu; Yahiro, Masanobu; Matsumoto, Takuma; Kohno, Michio

    2018-02-01

    An important current subject is to clarify the properties of chiral three-nucleon forces (3NFs) not only in nuclear matter but also in scattering between finite-size nuclei. Particularly for elastic scattering, this study has just started and the properties are not understood for a wide range of incident energies (E_in). We investigate basic properties of chiral 3NFs in nuclear matter with positive energies by using the Brueckner-Hartree-Fock method with chiral two-nucleon forces at N3LO and 3NFs at NNLO, and analyze the effects of chiral 3NFs on 4He elastic scattering from targets ^{208}Pb, ^{58}Ni, and ^{40}Ca over a wide range of 30 ≲ E_in/A_P ≲ 200 MeV by using the g-matrix folding model, where A_P is the mass number of the projectile. In symmetric nuclear matter with positive energies, chiral 3NFs make the single-particle potential less attractive and more absorptive. The effects mainly come from the Fujita-Miyazawa 2π-exchange 3NF and become slightly larger as E_in increases. These effects persist in the optical potentials of 4He scattering. As for the differential cross sections of 4He scattering, chiral-3NF effects are large for E_in/A_P ≳ 60 MeV and improve the agreement of the theoretical results with the measured ones. Particularly for E_in/A_P ≳ 100 MeV, the folding model reproduces measured differential cross sections pretty well. Cutoff (Λ) dependence is investigated for both nuclear matter and 4He scattering by considering two cases of Λ=450 and 550 MeV. The uncertainty coming from the dependence is smaller than chiral-3NF effects even at E_in/A_P=175 MeV.

  18. Improved proton-deuteron phase-shift analysis above the deuteron breakup threshold and the three-nucleon analyzing-power puzzle

    International Nuclear Information System (INIS)

    Tornow, W.; Kievsky, A.; Witala, H.

    2002-01-01

    Using the existing high-accuracy data for proton-deuteron and deuteron-proton elastic scattering, a phase-shift analysis has been performed in the laboratory proton energy range from E p = 4 to 10 MeV The AV 18-based proton-deuteron phase shifts were used as starting values in the phase-shift search procedure. The low-partial wave phase shifts, especially the 4 P j phase shifts have been determined very precisely, thus providing valuable guidance for theoretical approaches to tackle the quest for a successful description of three-nucleon bound-state and continuum observables in a more efficient and consistent way. Furthermore, it was found that the 4 P 1/2 phase shift and the mixing parameter ε 3/2 - determined in the present analysis cannot be generated by 3 P j nucleon-nucleon interactions which are consistent with two-nucleon analyzing power data. Therefore, three-nucleon forces must play an essential role in resolving the long-standing three-nucleon analyzing-power puzzle. Refs. 44 (author)

  19. Photoneutron and Photonuclear Cross Sections According to Packed cluster Model

    International Nuclear Information System (INIS)

    El-Mekkawi, L.S.; El-Bakty, O.M.

    1998-01-01

    Photonuclear gross sections have been estimated for 232 Th, 237 Np, 239 Pu, 233 U, 234 U, 235 U, 238 U in the energy range from threshold up to 20 MeV, by perturbation balance in Packed Cluster. The Packed Cluster (gamma, f) and (gamma, n) cross sections require complete absence of any (gamma,2n) or (gamma,nf) cross sections for 233 U and 234 U as in experiment. It also explains the early (gamma,n) and gamma,nf) reactions in 235 U

  20. Electro- and photonuclear physics with polarized beams and targets

    International Nuclear Information System (INIS)

    Holt, R.J.

    1987-01-01

    Two long-standing issues in photonuclear physics, the giant M1 resonance in Pb and deuteron photodisintegration, have been studied recently with polarized photons at Urbana and Frascati, respectively. The implications that this work has for settling these key issues will be discussed. In addition, the advantages of the internal polarized target method for electron scattering studies will be discussed and the technology of internal polarized target development will be reviewed. The first results from a spin-exchange, optically-pumped polarized H and D source will be presented

  1. Photonuclear reactions in the Δ-resonance region

    International Nuclear Information System (INIS)

    Arends, J.

    1988-02-01

    The following review is intended to give an overview of the experimental information on photon-induced reactions in comparison with theoretical calculations. Most of the experimental data presented here, were measured at the Bonn 500 MeV synchrotron. In section II the experimental techniques used for the measurements are briefly described. Section III deals with the most inclusive information, the total hadronic photoabsorption cross section. In sections IV and V, pion production and proton emission channels are discussed. A brief outlook to prospects for future photonuclear experiments at the new electron stretcher ELSA is given in section VI. (orig./HSI)

  2. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    2012-10-05

    Oct 5, 2012 ... Abstract. Low-energy solar neutrino detection plays a fundamental role in ... the experimental point of view, there are multiple ways to shed light among the different .... compared to the two metallicity expectations [16]. ..... from the Earth; solar neutrinos; indirect dark matter searches) and GeV physics (pro-.

  3. Low-energy nuclear physics

    International Nuclear Information System (INIS)

    1985-01-01

    The 1985 annual report of the Schuster Laboratory, Manchester University, England, on low-energy nuclear physics, is presented. The report includes experiments involving: high spin states, nuclei far from stability, reactions and fission, spectroscopy and related subjects. Technical developments are also described. (U.K.)

  4. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    Low-energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND ...

  5. Low Energy Neutrino Cross Sections

    International Nuclear Information System (INIS)

    Zeller, G.P.

    2004-01-01

    Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ∼ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies.Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy

  6. A low energy solar town

    Energy Technology Data Exchange (ETDEWEB)

    Svendsen, Svend; Balocco, Carla

    1998-12-31

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m{sup 2}/year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs.

  7. A low energy solar town

    International Nuclear Information System (INIS)

    Svendsen, Svend; Balocco, Carla

    1998-01-01

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m 2 /year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs

  8. Improved proton-deuteron phase-shift analysis above the deuteron breakup threshold and the three-nucleon analyzing-power puzzle

    CERN Document Server

    Tornow, W; Witala, H

    2002-01-01

    Using the existing high-accuracy data for proton-deuteron and deuteron-proton elastic scattering, a phase-shift analysis has been performed in the laboratory proton energy range from E sub p = 4 to 10 MeV The AV 18-based proton-deuteron phase shifts were used as starting values in the phase-shift search procedure. The low-partial wave phase shifts, especially the sup 4 P sub j phase shifts have been determined very precisely, thus providing valuable guidance for theoretical approaches to tackle the quest for a successful description of three-nucleon bound-state and continuum observables in a more efficient and consistent way. Furthermore, it was found that the sup 4 P sub 1 sub / sub 2 phase shift and the mixing parameter epsilon sub 3 sub / sub 2 sub sup - determined in the present analysis cannot be generated by sup 3 P sub j nucleon-nucleon interactions which are consistent with two-nucleon analyzing power data. Therefore, three-nucleon forces must play an essential role in resolving the long-standing thre...

  9. Photonuclear physics at the Bonn synchrotrons. Present status and future plans at the Bonn synchrotron

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1983-11-01

    The activities in the field of photonuclear physics at the Bonn 500 MeV and 2.5 GeV synchrotrons are reviewed. The experiments concentrate on photodisintegration and pion-photoproduction reactions on light nuclei. (orig.)

  10. Low energy bar pp physics

    International Nuclear Information System (INIS)

    Amsler, C.; Crowe, K.

    1989-02-01

    A detailed investigation of proton-antiproton interactions at low energy has become feasible with the commissioning of the LEAR facility in 1983. We shall shortly review the status of bar pp annihilation at rest and the physics motivations for second generation experiments with the Crystal Barrel detector. This type of detector would be adequate for the study of both Kp and bar pp interactions on an extracted beam of the KAON Factory. We shall conclude with a few remarks on the physics opportunities with bar p's at the KAON Factory which, in our opinion, will not be covered by the present LEAR facility. 11 refs., 10 figs., 2 tabs

  11. Photonuclear-based Detection of Nuclear Smuggling in Cargo Containers

    Science.gov (United States)

    Jones, J. L.; Haskell, K. J.; Hoggan, J. M.; Norman, D. R.; Yoon, W. Y.

    2003-08-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) and the Los Alamos National Laboratory (LANL) have performed experiments in La Honda, California and at the Idaho Accelerator Center in Pocatello, Idaho to assess and develop a photonuclear-based detection system for shielded nuclear materials in cargo containers. The detection system, measuring photonuclear-related neutron emissions, is planned for integration with the ARACOR Eagle Cargo Container Inspection System (Sunnyvale, CA). The Eagle Inspection system uses a nominal 6-MeV electron accelerator and operates with safe radiation exposure limits to both container stowaways and to its operators. The INEEL has fabricated custom-built, helium-3-based, neutron detectors for this inspection application and is performing an experimental application assessment. Because the Eagle Inspection system could not be moved to LANL where special nuclear material was available, the response of the Eagle had to be determined indirectly so as to support the development and testing of the detection system. Experiments in California have successfully matched the delayed neutron emission performance of the ARACOR Eagle with that of the transportable INEEL electron accelerator (i.e., the Varitron) and are reported here. A demonstration test is planned at LANL using the Varitron and shielded special nuclear materials within a cargo container. Detector results are providing very useful information regarding the challenges of delayed neutron counting near the photofission threshold energy of 5.5 - 6.0 MeV, are identifying the possible utilization of prompt neutron emissions to allow enhanced signal-to-noise measurements, and are showing the overall benefits of using higher electron beam energies.

  12. The low-energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Low-energy geothermal resources are characterized by temperatures ranging from 30 to 100 C. The principal worldwide applications are: towns and greenhouses heating, spa bathing, agriculture products drying, etc.. Sources depth ranges from 1500 to 2500 m in porous and permeable formations (sandstones, sands, conglomerates, limestones..) carrying aquifers. The worldwide installed power was of about 11500 MWth in 1990, with an annual production of about 36000 GWh (about 1% of worldwide energy consumption). The annual production rate is estimated to 10% and would represent a 30000 and 80000 MWth power in 2000 and 2010, respectively. In France, low-energy geothermal resources are encountered principally in Mesozoic sediments of the Parisian and Aquitanian basins. French geothermics has developed during the last 30 years and principally between 1980 and 1985 after the second petroleum crack. After 1985, the decay of fossil fuel costs and the development of corrosion problems in the geothermal wells have led to the abandonment of the less productive fields and to the study of technical solutions to solve the corrosion problems. (J.S.). 1 fig., 5 photos

  13. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

    and with as little energy consumption as 41.1 kWh/m2/year including heating and all building services with no use of renewable energy such as PVcells or solar heating. One of the key means of reaching the objectives was to implement mechanical ventilation with low pressure loss and therefore low energy consumption....... The project consists of two buildings, building one is 6 stories high, and building two is 4 stories high. The buildings have a gross area of 50,500 m2 including underground parking. The ventilation and indoor climate concept was to use mechanical ventilation together with mechanical cooling and fanassisted......, with an average of 1.1 kJ/m3. The yearly mean SFP based on estimated runtime is approx. 0.8 kJ/m3. The case shows the unlocked potential that lies within mechanical ventilation for nearzero energy consuming buildings....

  14. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    For a class of negative slowly decaying potentials, including with , we study the quantum mechanical scattering theory in the low-energy regime. Using modifiers of the Isozaki--Kitada type we show that scattering theory is well behaved on the {\\it whole} continuous spectrum of the Hamiltonian......, including the energy . We show that the --matrices are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use appropriate weighted spaces. These results are used...... from positive energies to the limiting energy . This change corresponds to the behaviour of the classical orbits. Under stronger conditions we extract the leading term of the asymptotics of the kernel of at its singularities; this leading term defines a Fourier integral operator in the sense...

  15. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    2009-01-01

    For a class of negative slowly decaying potentials, including V(x):=−γ|x|−μ with 0quantum mechanical scattering theory in the low-energy regime. Using appropriate modifiers of the Isozaki–Kitada type we show that scattering theory is well behaved on the whole continuous spectrum...... of the Hamiltonian, including the energy 0. We show that the modified scattering matrices S(λ) are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the modified wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use...... of the kernel of S(λ) experiences an abrupt change from passing from positive energies λ to the limiting energy λ=0 . This change corresponds to the behaviour of the classical orbits. Under stronger conditions one can extract the leading term of the asymptotics of the kernel of S(λ) at its singularities....

  16. Theory of low energy collisions

    International Nuclear Information System (INIS)

    Sparenberg, J.M.

    2007-01-01

    The basic notions of low-energy quantum scattering theory are introduced (cross sections, phase shifts, resonances,... ), in particular for positively-charged particles, in view of nuclear physics applications. An introduction to the reaction-matrix (or R-matrix) method is then proposed, as a tool to both solve the Schroedinger equation describing collisions and fit experimental data phenomenologically. Most results are established without proof but with a particular emphasis on their intuitive understanding and their possible analogs in classical mechanics. Several choices are made consequently: (i) the text starts with a detailed reminder of classical scattering theory, (ii) the concepts are first introduced in ideal theoretical cases before going to the more complicated formalism allowing the description of realistic experimental situations, (iii) a single example is used throughout nearly the whole text, (iv) all concepts are established for the elastic scattering of spinless particles, with only a brief mention of their multichannel generalization at the end of the text. (author)

  17. Techniques for vector analyzing power measurements of the 2H(n vector,np)n breakup reaction at low energies

    International Nuclear Information System (INIS)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L.; Lambert, J.M.; Treado, P.A.

    1990-01-01

    Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the 2 H(d vector, n vector) 3 He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.)

  18. Techniques for vector analyzing power measurements of the sup 2 H(n vector,np)n breakup reaction at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L. (Duke Univ., Durham, NC (USA) Triangle Universities Nuclear Lab., Durham, NC (USA)); Lambert, J.M.; Treado, P.A. (Georgetown Univ., Washington, DC (USA). Dept. of Physics); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia))

    1990-05-10

    Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the {sup 2}H(d vector, n vector){sup 3}He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.).

  19. Intense low energy positron beams

    International Nuclear Information System (INIS)

    Lynn, K.G.; Jacobsen, F.M.

    1993-01-01

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e + beams exist producing of the order of 10 8 - 10 9 e + /sec. Several laboratories are aiming at high intensity, high brightness e + beams with intensities greater than 10 9 e + /sec and current densities of the order of 10 13 - 10 14 e + sec - 1 cm -2 . Intense e + beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B + moderators or by increasing the available activity of B + particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e + collisions with atoms and molecules. Within solid state physics high intensity, high brightness e + beams are in demand in areas such as the re-emission e + microscope, two dimensional angular correlation of annihilation radiation, low energy e + diffraction and other fields. Intense e + beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies

  20. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Hoshi, Masaharu; Antoku, Shigetoshi; Russell, W.J.; Miller, R.C.; Nakamura, Nori; Mizuno, Masayoshi; Nishio, Shoji.

    1987-05-01

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60 Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60 Co. The RBE of 200 kVp X rays relative to 60 Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  1. Low energy physics from superstrings

    International Nuclear Information System (INIS)

    Segre, G.C.

    1987-01-01

    The developments of the past year have resulted in growing interest in the theory of superstrings, a subject which is on the one hand extraordinarily exciting in the promise it holds for solutions of many of the outstanding problems of particle physics and on the other hand rather forbidding in the amount of new knowledge which needs to be acquired by the average theorist to understand the papers that are now being published on the recent developments. In a sense the term low energy superstrings is misleading: the work of the past fifteen years in string theory, culminating in last summer's stunning developments by Green and Schwartz have led theorists to believe a finite, consistent superstring theory can be formulated. An enormous amount of work is going on in this subject, the premise that an effective field theory in ten space-time dimensions can be obtained from the superstring theory is the start of the lectures. The lectures will cover this later stage, namely how does one proceed from the effective ten dimensional theory to an effective four dimensional theory, describing the world as we see it. 87 references, 2 tables

  2. Pre-equilibrium particle decay in the photonuclear reactions

    International Nuclear Information System (INIS)

    Wu, J.R.; Chang, C.C.

    1976-11-01

    Calculations of particle energy spectra resulting from the photonuclear reactions at energies below the meson production threshold have been carried out in the framework of combining the pre-equilibrium exiton model and the quasi-deuteron model. A 2p-2h initial state in the exciton model is assumed because in the energy region above giant resonance the quasi-deuteron absorption is the dominant process. With these combined models, the subsequent secondary interactions of the emerging particle with the rest of the nucleus following the initial photon-nucleus interaction are appropriately taken into account. The experimental difference energy spectra of fast photoneutrons from several elements (Al, Cu, In, Sn, Ta, Pb, Bi and U) at bremsstrahlung energies of 55 and 85 MeV and the photoproton energy spectra from 12 C at bremsstrahlung energy 110 MeV were compared with the theoretical predictions. General agreements in both spectral shapes and cross sections are obtained. The relative yields of the reactions (γ, xn) resulting from monoenergetic photons on 127 I at 50, 100 and 150 MeV are also predicted reasonably well by the combined models together with the conventional evaporation theory

  3. Towards Low Energy Atrial Defibrillation

    Directory of Open Access Journals (Sweden)

    Philip Walsh

    2015-09-01

    . Efficient transcutaneous power transfer and sensing of ICI during cardioversion are evidenced as key to the advancement of low-energy atrial defibrillation.

  4. Atlas of giant dipole resonances. Parameters and graphs of photonuclear reaction cross sections

    International Nuclear Information System (INIS)

    Varlamov, A.V.; Varlamov, V.V.; Rudenko, D.S.; Stepanov, M.E.

    1999-01-01

    Parameters of giant dipole resonances (GDR) observed in photonuclear reaction cross sections using various beams of incident photons are presented. Data, given for 200 stable isotopes from 2 H to 243 Am including their natural compositions, were collected from papers published over the years 1951-1996. GDR parameters, such as energy positions, amplitudes and widths, are included into the table and organized by element, isotope and reaction. Graphs of the majority of the photonuclear reaction cross sections, included in the international nuclear data library EXFOR by the end of 1998, are presented. The graphs are provided for 182 stable isotopes and natural compositions. (author)

  5. Perspectives for photonuclear research at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility

    Energy Technology Data Exchange (ETDEWEB)

    Filipescu, D.; Balabanski, D.L.; Constantin, P.; Gales, S.; Tesileanu, O.; Ur, C.A.; Ursu, I.; Zamfir, N.V. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Bucharest-Magurele (Romania); Anzalone, A.; La Cognata, M.; Spitaleri, C. [INFN-LNS, Catania (Italy); Belyshev, S.S. [Lomonosov Moscow State University, Physics Faculty, Moscow (Russian Federation); Camera, F. [Departement of Physics, University of Milano, Milano (Italy); INFN section of Milano, Milano (Italy); Csige, L.; Krasznahorkay, A. [Hungarian Academy of Sciences (MTA Atomki), Institute of Nuclear Research, Post Office Box 51, Debrecen (Hungary); Cuong, P.V. [Vietnam Academy of Science and Technology, Centre of Nuclear Physics, Institute of Physics, Hanoi (Viet Nam); Cwiok, M.; Dominik, W.; Mazzocchi, C. [University of Warsaw, Warszawa (Poland); Derya, V.; Zilges, A. [University of Cologne, Institute for Nuclear Physics, Cologne (Germany); Gai, M. [University of Connecticut, LNS at Avery Point, Connecticut, Groton (United States); Gheorghe, I. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Bucharest-Magurele (Romania); University of Bucharest, Nuclear Physics Department, Post Office Box MG-11, Bucharest-Magurele (Romania); Ishkhanov, B.S. [Lomonosov Moscow State University, Physics Faculty, Moscow (Russian Federation); Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Kuznetsov, A.A.; Orlin, V.N.; Stopani, K.A.; Varlamov, V.V. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Pietralla, N. [Technische Universitat Darmstadt, Institut fur Kernphysik, Darmstadt (Germany); Sin, M. [University of Bucharest, Nuclear Physics Department, Post Office Box MG-11, Bucharest-Magurele (Romania); Utsunomiya, H. [Konan University, Department of Physics, Kobe (Japan); University of Tokyo, Center for Nuclear Study, Saitama (Japan); Weller, H.R. [Triangle Universities Nuclear Laboratory, North Carolina, Durham (United States); Duke University, Department of Physics, North Carolina, Durham (United States)

    2015-12-15

    The perspectives for photonuclear experiments at the new Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility are discussed in view of the need to accumulate novel and more precise nuclear data. The parameters of the ELI-NP gamma beam system are presented. The emerging experimental program, which will be realized at ELI-NP, is presented. Examples of day-one experiments with the nuclear resonance fluorescence technique, photonuclear reaction measurements, photofission experiments and studies of nuclear collective excitation modes and competition between various decay channels are discussed. The advantages which ELI-NP provides for all these experiments compared to the existing facilities are discussed. (orig.)

  6. Systematic study of three-nucleon force effects in the cross section of the deuteron-proton breakup at 130 MeV

    International Nuclear Information System (INIS)

    St. Kistryn; E. Stephan; A. Biegun; K. Bodek; A. Deltuva; E. Epelbaum; K. Ermisch; W. Gloeckle; J. Golak; N. Kalantar-Nayestanaki; H. Kamada; M. Kis; B. Klos; A. Kozela; J. Kuros-Zolnierczuk; M. Mahjour-Shafiei; U.-G. Meissner; A. Micherdzinska; A. Nogga; P. U. Sauer; R. Skibinski; R. Sworst; H. Witala; J. Zejma; W. Zipper

    2005-01-01

    High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (NN) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the Delta-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant NN and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics

  7. Neutron-deuteron analyzing power data at En = 21 MeV and the energy dependence of the three-nucleon analyzing power puzzle

    Science.gov (United States)

    Weisel, G. J.; Tornow, W.; Esterline, J. H.

    2015-08-01

    We present measurements of n-d analyzing power, {A}y(θ ), at En = 21.0 MeV. The experiment produces neutrons via the 2H(d, n)3He reaction and uses a deuterated liquid-scintillator center detector and six pairs of liquid-scintillator neutron side detectors. Elastic neutron scattering events are identified by using time-of-flight techniques and by setting a gate in the center-detector pulse-height spectrum. Beam polarization is monitored by using a high-pressure helium gas scintillator. The n-d {A}y(θ ) data at 21.0 MeV show a significant discrepancy with the results of rigorous three-body calculations and are consistent with data taken previously by us at 19.0 and 22.5 MeV. We review the overall energy dependence of the three-nucleon analyzing power puzzle in neutron-deuteron elastic scattering, using the best data available. We find that the relative difference between calculations and data is nearly constant at 25% up to En = 22.5 MeV.

  8. The 58606264Ni(p,α)55575961Co reactions and their description by the semi-microscopic model for three-nucleon transfer

    International Nuclear Information System (INIS)

    Smits, J.W.; Siemssen, R.H.; Werf, S.Y. van der; Woude, A. van der

    1979-01-01

    The (p,α) reaction on the even-A nickel isotopes has been studied at an incident proton energy of 30 MeV. Between 14 and 26 states, or groups of states, were analysed for each of the residual cobalt isotopes. For these transitions angular distributions were determined from thetasub(lab) = 7.5 0 to 70 0 . In all reactions the proton-hole states (0fsub(7/2), 1ssub(1/2) and 0dsub(3/2)) stand out in the spectra. Also, states formed by the weak-coupling of the proton-holes to excitations of the neutron core were seen. Differences in the relative strengths of the positive-parity hole states between the proton pickup and the (p,α) data can be explained by a semi-microscopic model for three-nucleon transfer. Also the strength distribution of the transitions to the lowest weak-coupling quintuplet is correctly predicted. These results underline the importance of the inclusion of non-zero coupled neutron pairs into the description of (p, α) reactions. Several T> states are observed in the 58 Ni(p, α) 55 Co reactions

  9. Low-energy Electro-weak Reactions

    International Nuclear Information System (INIS)

    Gazit, Doron

    2012-01-01

    Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.

  10. Theorems of low energy in Compton scattering

    International Nuclear Information System (INIS)

    Chahine, J.

    1984-01-01

    We have obtained the low energy theorems in Compton scattering to third and fouth order in the frequency of the incident photon. Next we calculated the polarized cross section to third order and the unpolarized to fourth order in terms of partial amplitudes not covered by the low energy theorems, what will permit the experimental determination of these partial amplitudes. (Author) [pt

  11. Weisskopf–Ewing and Hauser–Feshbach calculations of photonuclear cross sections used for electromagnetic dissociation

    International Nuclear Information System (INIS)

    Adamczyk, Anne M.; Norbury, John W.; Townsend, Lawrence W.

    2013-01-01

    The Weisskopf–Ewing (WE) and Hauser–Feshbach (HF) theory are statistical methods, which are often used to calculate photonuclear cross sections for compound nucleus reactions. In our past work, WE methodology was presented and photonuclear reaction cross sections for nucleon emission were calculated using WE theory. Here, our previous results, which neglect pre-equilibrium emissions and do not include multiple particle emission, are compared to those calculated with HF theory and experimental data. For the reactions considered herein, it is found that the WE theory and HF method are in reasonable agreement below the two neutron separation energy assuming an energy dependent branching ratio for intermediate and heavy nuclei. In addition, qualitative confidence of WE theory for electromagnetic dissociation (EMD) cross section calculations was found. - Author-Highlights: • The Weisskopf–Ewing (WE) theory is reviewed. • Photonuclear cross sections calculated with WE theory are compared to HF predictions. • The WE theory and the HF method give similar photonuclear cross sections. • Qualitative confidence of WE theory for EMD cross section calculations is found

  12. A measurement of the photonuclear interactions of 180 GeV muons in iron

    Czech Academy of Sciences Publication Activity Database

    Alexa, C.; Anderson, K.; Antonaki, A.; Lokajíček, Miloš; Němeček, Stanislav; Nessi, M.; Sýkora, I.; Vartapetian, A.; Vinogradov, V.; Zaitsov, A.

    2003-01-01

    Roč. 28, - (2003), s. 297-304 ISSN 1434-6044 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : hadronic calorimeter * cross section * photonuclear ineractions * tile calorimeter Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.580, year: 2003

  13. Hyperon production in photonuclear reactions on protons and deuterons : The Kappa(0)Sigma(+) channel

    NARCIS (Netherlands)

    Lohner, H; Bacelar, J; Castelijns, R; Messchendorp, J; Shende, S; Maeda, K; Tamura, H; Nakamura, SN; Hashimoto, O

    2004-01-01

    With the combined setup of the Crystal Barrel and TAPS photonspectrometers at ELSA in Bonn we have studied photonuclear reactions on protons and deuterons. From the series of experiments on single and multiple neutral meson emission we concentrate here on the hyperon production off protons and

  14. Code and data benchmarking with the new IAEA photonuclear data library

    International Nuclear Information System (INIS)

    Ridikas, D.; Vertes, P.

    2004-01-01

    As a result of an international co-operative activity, a recommended file of photonuclear reactions of 164 isotopes became available. The format and practical quality of these data are examined by using them for the calculation of photoneutron production in thick targets bombarded by photons and electrons. The Monte Carlo calculations are accomplished with a recent version of the MCNP code enhanced with a photonuclear capability. The energy range of our investigations is from the photonuclear threshold up to 150 MeV. In some cases, a comparison between our calculations and a new version of the MCNPX code, recently updated with the LANL photonuclear data files (12 isotopes) is established. Our results are also compared with the experimental data when available. These data include early measurements of the total neutron yields from thick targets bombarded by electrons as a function of energy, target thickness and atomic number, as well as recent measurements of 238 U photofission yields. We show that in general the agreement between the experimental and calculated results is satisfactory. However, a number of particular examples where this is not the case seem to exist. Most of these cases are identified. (author)

  15. The International Evaluated Nuclear Structure Data File (ENSDF) in fundamental and applied photonuclear research

    International Nuclear Information System (INIS)

    Boboshin, I.N.; Varlamov, V.V.

    1989-04-01

    In order to provide the necessary nuclear physics data from the ENSDF file to those carrying out fundamental or applied photonuclear research a specialized software system was set up on an ES computer. A brief description of the block diagram of this software package and of one of the programs in this package (SUPER) is given. 4 refs, 6 figs

  16. Summary report of the 1. research co-ordination meeting on compilation and evaluation of photonuclear data for applications

    International Nuclear Information System (INIS)

    1997-04-01

    The present report contains the summary of the first Research Co-ordination Meeting on ''Compilation and Evaluation of Photonuclear Data for Applications'', held in Obninsk, Russia, from 3 to 6 December 1996. The project aims to produce a Technical Document on Photonuclear Data Library for Applications and to develop an IAEA Photonuclear Data Library. Summarized are the conclusions and recommendations of the meeting together with a detailed list of actions. Attached is the information sheet on the project, the agenda of the meeting and the list of participants along with extended abstracts of their presentations. Refs, figs, tabs

  17. Solar-assisted low energy dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, T V

    1980-02-01

    The Zero Energy House Group was formed as a subproject of the CCMS Solar Energy Pilot Study in 1974 by seven participating countries experimenting with solar-assisted low-energy dwellings for temperate and northern European climatic conditions. A Zero Energy House is one in which solar energy is used to meet the reduced energy needs of buildings incorporating various thermal energy conservation features. This final report of the Zero Energy House Group includes brief descriptions of 13 major low-energy dwellings in the participating CCMS countries. An overall assessment of the state-of-the-art in solar-assisted low-energy dwellings is also included.

  18. Electromagnetic interactions of nucleons and nuclei at low energy and momentum transfer

    International Nuclear Information System (INIS)

    Arenhoevel, H.

    1994-01-01

    In these lectures I concentrate on the manifestation of subnuclear degrees of freedom in terms of meson and isobar degrees of freedom in electromagnetic processes where their presence usually is described in terms of so-called exchange or interaction currents. In Section 2 I first discuss the general properties of the electromagnetic interaction, the gauge conditions and low-energy theorems which follow from gauge invariance, the charge and current density operators for a non-relativistic system of nucleons and the Siegert theorem. In Section 3 I sketch the basic ideas and construction methods for the exchange current operators as effective operators and in Section 4 the model of nuclear isobar configurations introducing explicitly isobar degrees of freedom into the nuclear wave function. The general features of one- and two-photon processes are discussed in Section 5. First the expressions for the cross sections of photoabsorption and electron scattering are reviewed. As a specific but important example, I then discuss the two-body break-up of the deuteron since it permits the cleanest analysis and provides one of the best evidences for the presence of subnuclear degrees of freedom due to its simple two-body structure within the classical nuclear physics framework. This is a unique situation because in more complex nuclei the analysis is often hampered by presently still unavoidable approximations of the many-body problem. I furthermore discuss the role of meson exchange currents in the photonuclear TRK sum rule, in particular, I carefully analyse what determines the enhancement. This section ends with a brief discussion of elastic photon scattering with special emphasis on the low-energy theorem for the scattering amplitude and the sum rule relations for the low-energy parameters. (orig.)

  19. Fundamental physics with low-energy neutrons

    International Nuclear Information System (INIS)

    Barrón-Palos, Libertad

    2016-01-01

    Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing. (paper)

  20. Pion nucleon interaction at low energy

    International Nuclear Information System (INIS)

    Banerjee, M.K.

    1979-03-01

    A theory of the πN interaction at low energy is described. An analogy is made with an unusual approach to potential scattering theory. Phase shifts, cross sections, and scattering amplitudes and lengths are calculated. 28 references

  1. Current status of low energy EB machine

    International Nuclear Information System (INIS)

    Toshiro Nishikimi; Shuichi Taniguchi; Kenichi Mizusawa

    1999-01-01

    Electron beam processing systems have been in use in a variety of applications such as curing of paints and printing inks, crosslinking of PE products, treating of rubber tire and so on. Low energy electron processing systems have become popular as self-shielded machines, which are compact and easy to use and do not require special facility as an irradiation room. This manuscript introduces the status of low energy EB (electron beam) machine through Nissin's products current

  2. Enhancement Mechanisms of Low Energy Nuclear Reactions

    OpenAIRE

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

    2005-01-01

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

  3. Exploring the Hidden Sector @ Low Energies

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Over the years we have accumulated a large number of indications for physics beyond the standard model. This new physics is often sought-after at high masses and energies. Here collider experiments can bring decisive insights. However, over recent years it has become increasingly clear that new physics can also appear at low energy, but extremely weak coupling. Experiments and observations at this `low energy frontier' therefore provide a powerful tool to gain insight into fundamental physics, which is complementary to accelerators.

  4. Contribution to the study of neutron-neutron interactions using the three-nucleon experiment D(n,nnp) at 14.5 MeV: evaluation of parasitic events

    International Nuclear Information System (INIS)

    Ducharme, C.

    1969-01-01

    This work is related to the interpretation of the results concerning the three nucleon experiment, D(n,nnp), at 14.5 MeV, carried out by double time-of-flight spectrometry. The present work consists in the simulation of the main parasitic events using the Monte-Carlo method for extracting them from the experimental distribution around the n-n pole. (author) [fr

  5. Surface sterilization by low energy electron beams

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Tabei, Masae

    1989-01-01

    The germicidal effectiveness of low energy electron beams (175 KV) against bacterial cells was investigated. The dry spores of Bacillus pumilus ATCC 27142 and Bacillus globigii ATCC 9372 inoculated on carrier materials and irradiated by gamma rays showed the exponential type of survival curves whereas they showed sigmoidal ones when exposed to low energy electron beams. When similarly irradiated, the wet spores inoculated on membrane filter showed the same survival curves as the dry spores inoculated on carrier materials. The wet vegetative cells of Escherichia coli ATCC 25922 showed exponential curves when exposed to gamma and electron beam irradiation. Low energy electron beams in air showed little differences from nitrogen stream in their germicidal effectiveness against dry spores of B. pumilus. The D values of B. pumilus spores inoculated on metal plates decreased as the amounts of backscattering electrons from the plates increased. There was adequate correlation between the D value (linear region of survival curve), average D value (6D/6) and 1% survival dose and backscattering factor. Depth dose profile and backscatterig dose of low energy electron beams were measured by radiochromic dye film dosimeter (RCD). These figures were not always in accord with the observed germicidal effectiveness against B. pumilus spores because of varying thickness of RCD and spores inoculated on carrier material. The dry spores were very thin and this thinness was useful in evaluating the behavior of low energy electrons. (author)

  6. Handbook on photonuclear data for applications. Cross-sections and spectra. Final report of a co-ordinated research project 1996-1999

    International Nuclear Information System (INIS)

    2000-10-01

    This document provides users of photonuclear data with an up-to-date overview of photonuclear reaction data. In addition to production cross sections, energy and angular distributions of the emitted particles are provided. The material is presented in a systematic way, covering experimental data and their compilation, an introduction to relevant parts of nuclear reaction theory, an exposition of evaluation methodology used to generate evaluations, an intercomparison of different evaluations, and a description of the IAEA Photonuclear Data Library

  7. Low energy plasma observations at synchronous orbit

    International Nuclear Information System (INIS)

    Reasoner, D.L.; Lennartsson, W.

    1977-08-01

    The University of California at San Diego Auroral Particles Experiment on the ATS-6 Satellite in synchronous orbit has detected a low-energy plasma population which is separate and distinct from both the ring current and plasma sheet populations. These observations suggest that this plasma is the outer zone of the plasmasphere. During magnetically active periods, this low energy plasma is often observed flowing sunward. In the dusk sector, enhanced plasma flow is often observed for 1-2 hours prior to the onset of a substorm-associated particle injection. (author)

  8. Low-energy meson physics (chiral theory)

    International Nuclear Information System (INIS)

    Volkov, M.K.; Pervushin, V.N.

    1976-01-01

    A quantum chiral theory which allows to obtain low-energy expansions of various hadron processes without introducing arbitrary parameters into the theory with the exception of hadron masses and interaction constants is presented. A hypothesis about the dynamic symmetry of strong interactions is suggested. The interaction lagrangian is derived which satisfies conditions of the dynamic symmetry. Examples of the use of the quantum chiral theory for describing low-energy processes of meson interaction are given. It is noted that the results obtained reproduce the actual qualitative pattern of various physical processes and in most cases result in good quantitative agreement with experiments

  9. Photonuclear reaction as a probe for α -clustering nuclei in the quasi-deuteron region

    Science.gov (United States)

    Huang, B. S.; Ma, Y. G.; He, W. B.

    2017-03-01

    Photon-nuclear reaction in a transport model frame, namely an extended quantum molecular dynamics model, has been realized at the photon energy of 70-140 MeV in the quasi-deuteron regime. For an important application, we pay a special focus on photonuclear reactions of 12C(γ ,n p )10B where 12C is considered as different configurations including α clustering. Obvious differences for some observables have been observed among different configurations, which can be attributed to spatial-momentum correlation of a neutron-proton pair inside nucleus, and therefore it gives us a sensitive probe to distinguish the different configurations including α clustering with the help of the photonuclear reaction mechanism.

  10. Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

    CERN Document Server

    Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

    2005-01-01

    An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

  11. Application of photonuclear methods of analysis in biology, medicine, ecological studies

    International Nuclear Information System (INIS)

    Burmistenko, Yu.N.

    1986-01-01

    Examples of application of photonuclear methods of analysis (PhMA) of the substance composition in biology, medicine, ecology are considered. The methods for determining the element composition of soft and bone tissues, blood, urine are developed. The results of studying the limits of determination of different elements are presented. In ecological investigations PhMA is applied for studying the composition of atmospheric aerosols, industrial sewage, canalization wastes, pollution of soil, plants, animals with toxic elements

  12. On the usage of electron beam as a tool to produce radioactive isotopes in photonuclear reactions

    International Nuclear Information System (INIS)

    Bunatyan, G.G.; Nikolenko, V.G.; Popov, A.B.

    2009-01-01

    We treat the Bremsstrahlung, induced by initial electron beam in converter, and the production of a desirable radioisotope due to the photonuclear reaction caused by this Bremsstrahlung. By way of illustration, the yield of a number of some, the most applicable in practice, radioisotopes is evaluated. The acquired findings persuade us that usage of modern electron accelerators offers a practicable way to produce the radioisotopes needful nowadays for various valuable applications in the nuclear medicine

  13. Interstellar propagation of low energy cosmic rays

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1975-01-01

    Wave particles interactions prevent low energy cosmic rays from propagating at velocities much faster than the Alfven velocity, reducing their range by a factor of order 50. Therefore, supernovae remnants cannot fill the neutral portions of the interstellar medium with 2 MeV cosmic rays [fr

  14. Virtual compton scattering at low energy

    International Nuclear Information System (INIS)

    Lhuillier, D.

    1997-09-01

    The work described in this PhD is a study of the Virtual Compton scattering (VCS) off the proton at low energy, below pion production threshold. Our experiment has been carried out at MAMI in the collaboration with the help of two high resolution spectrometers. Experimentally, the VCS process is the electroproduction of photons off a liquid hydrogen target. First results of data analysis including radiative corrections are presented and compared with low energy theorem prediction. VCS is an extension of the Real Compton Scattering. The virtuality of the incoming photon allows us to access new observables of the nucleon internal structure which are complementarity to the elastic form factors: the generalized polarizabilities (GP). They are function of the squared invariant mass of the virtual photo. The mass limit of these observables restore the usual electric and magnetic polarizabilities. Our experiment is the first measurement of the VCS process at a virtual photon mass equals 0.33 Ge V square. The experimental development presents the analysis method. The high precision needed in the absolute cross-section measurement required an accurate estimate of radiative corrections to the VCS. This new calculation, which has been performed in the dimensional regulation scheme, composes the theoretical part of this thesis. At low q', preliminary results agree with low energy theorem prediction. At higher q', substraction of low energy theorem contribution to extract GP is discussed. (author)

  15. Physics with low energy pions and muons

    International Nuclear Information System (INIS)

    Konijn, J.

    1981-01-01

    This document is a collection of texts used for a course of lectures given by the author at the Technical University of Delft (NL) in 1981. It is therefore a comprehensive, Dutch language, review article starting with the discovery of pions and muons, describing their properties and finally discussing their applications in low energy physics. (C.F.)

  16. Cooking exhaust systems for low energy dwellings

    NARCIS (Netherlands)

    Jacobs, P.; Borsboom, W.A.

    2017-01-01

    Especially in airtight low energy dwellings exhaust systems are of utmost importance as cooking can be a major source of PM2.5 exposure. Dwellings should be designed including facilities enabling extraction of at least 83 dm3/s (300 m3/h) directly to outside. Residents should be able to select an

  17. Low energy antiproton experiments - A review

    NARCIS (Netherlands)

    Jungmann, KP; Yamazaki, Y; Wada, M

    2005-01-01

    Low energy antiprotons offer excellent opportunities to study properties of fundamental forces and symmetries in nature. Experiments with them can contribute substantially to deepen our fundamental knowledge in atomic, nuclear and particle physics. Searches for new interactions can be carried out by

  18. The Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Lechner, Peter

    2009-01-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  19. The Simbol-X Low Energy Detector

    Science.gov (United States)

    Lechner, Peter

    2009-05-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  20. Low energy analysis techniques for CUORE

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Avignone, F.T.; Chott, N.; Creswick, R.J.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Alfonso, K.; Huang, H.Z.; Sakai, M.; Schmidt, J. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Artusa, D.R.; Rusconi, C. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Azzolini, O.; Camacho, A.; Keppel, G.; Palmieri, V.; Pira, C. [INFN-Laboratori Nazionali di Legnaro, Padua (Italy); Bari, G.; Deninno, M.M. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cosmelli, C.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Benato, G.; Singh, V. [University of California, Department of Physics, Berkeley, CA (United States); Bersani, A.; Caminata, A. [INFN-Sezione di Genova, Genoa (Italy); Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Fiorini, E.; Gironi, L.; Gotti, C.; Maino, M.; Nastasi, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Branca, A.; Taffarello, L. [INFN-Sezione di Padova, Padua (Italy); Bucci, C.; Cappelli, L.; D' Addabbo, A.; Gorla, P.; Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Canonica, L. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Massachusetts Institute of Technology, Cambridge, MA (United States); Cao, X.G.; Fang, D.Q.; Ma, Y.G.; Wang, H.W.; Zhang, G.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China); Cardani, L.; Casali, N.; Dafinei, I.; Morganti, S.; Mosteiro, P.J.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Copello, S.; Di Domizio, S.; Marini, L.; Pallavicini, M. [INFN-Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Cremonesi, O.; Ferri, E.; Giachero, A.; Pessina, G.; Previtali, E. [INFN-Sezione di Milano Bicocca, Milan (Italy); Cushman, J.S.; Davis, C.J.; Heeger, K.M.; Lim, K.E.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); D' Aguanno, D.; Pagliarone, C.E. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita degli Studi di Cassino e del Lazio Meridionale, Dipartimento di Ingegneria Civile e Meccanica, Cassino (Italy); Dell' Oro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); INFN-Gran Sasso Science Institute, L' Aquila (Italy); Di Vacri, M.L.; Santone, D. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, L' Aquila (Italy); Drobizhev, A.; Hennings-Yeomans, R.; Kolomensky, Yu.G.; Wagaarachchi, S.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Franceschi, M.A.; Ligi, C.; Napolitano, T. [INFN-Laboratori Nazionali di Frascati, Rome (Italy); Freedman, S.J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Fujikawa, B.K.; Mei, Y.; Schmidt, B.; Smith, A.R.; Welliver, B. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Giuliani, A.; Novati, V. [Universite Paris-Saclay, CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Orsay (France); Gladstone, L.; Leder, A.; Ouellet, J.L.; Winslow, L.A. [Massachusetts Institute of Technology, Cambridge, MA (United States); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Han, K. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Shanghai (China); Hansen, E. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Saragossa (Spain); Moggi, N.; Zucchelli, S. [INFN-Sezione di Bologna, Bologna (Italy); Universita di Bologna - Alma Mater Studiorum, Dipartimento di Fisica e Astronomia, Bologna (IT); Nones, C. [CEA/Saclay, Service de Physique des Particules, Gif-sur-Yvette (FR); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (US); University of California, Department of Nuclear Engineering, Berkeley, CA (US); O' Donnell, T. [Virginia Polytechnic Institute and State University, Center for Neutrino Physics, Blacksburg, VA (US); Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (US); Wise, T. [Yale University, Department of Physics, New Haven, CT (US); University of Wisconsin, Department of Physics, Madison, WI (US); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (GB); Zimmermann, S. [Lawrence Berkeley National Laboratory, Engineering Division, Berkeley, CA (US)

    2017-12-15

    CUORE is a tonne-scale cryogenic detector operating at the Laboratori Nazionali del Gran Sasso (LNGS) that uses tellurium dioxide bolometers to search for neutrinoless double-beta decay of {sup 130}Te. CUORE is also suitable to search for low energy rare events such as solar axions or WIMP scattering, thanks to its ultra-low background and large target mass. However, to conduct such sensitive searches requires improving the energy threshold to 10 keV. In this paper, we describe the analysis techniques developed for the low energy analysis of CUORE-like detectors, using the data acquired from November 2013 to March 2015 by CUORE-0, a single-tower prototype designed to validate the assembly procedure and new cleaning techniques of CUORE. We explain the energy threshold optimization, continuous monitoring of the trigger efficiency, data and event selection, and energy calibration at low energies in detail. We also present the low energy background spectrum of CUORE-0 below 60 keV. Finally, we report the sensitivity of CUORE to WIMP annual modulation using the CUORE-0 energy threshold and background, as well as an estimate of the uncertainty on the nuclear quenching factor from nuclear recoils in CUORE-0. (orig.)

  1. Large solid angle detectors (low energy)

    International Nuclear Information System (INIS)

    L'Hote, D.

    1988-01-01

    This lecture deals with large solid angle detectors used in low energy experiments (mainly in Nuclear Physics). The reasons for using such detectors are discussed, and several basic principles of their design are presented. Finally, two examples of data analysis from such detectors are given [fr

  2. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  3. Studies in Low-Energy Nuclear Science

    Energy Technology Data Exchange (ETDEWEB)

    Carl R. Brune; Steven M. Grimes

    2010-01-13

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187.

  4. Low energy intense electron beams with extra-low energy spread

    International Nuclear Information System (INIS)

    Aleksandrov, A.V.; Calabrese, R.; Ciullo, G.; Dikansky, N.S.; Guidi, V.; Kot, N.C.; Kudelainen, V.I.; Lamanna, G.; Lebedev, V.A.; Logachov, P.V.; Tecchio, L.; Yang, B.

    1994-01-01

    Maximum achievable intensity for low energy electron beams is a feature that is not very often compatible with low energy spread. We show that a proper choice of the source and the acceleration optics allows one to match them together. In this scheme, a GaAs photocathode excited by a single-mode infrared laser and adiabatic acceleration in fully magnetised optics enables the production of a low-energy-spread electron beam with relatively high intensity. The technological problems associated with the method are discussed together with its limitations. (orig.)

  5. Experimentation with low-energy positron beams

    International Nuclear Information System (INIS)

    Mills, A.P. Jr.

    1983-01-01

    The capability of studying the interactions of positrons with surfaces has recently been exploited by using ultra-high-vacuum techniques. The result has been a new understanding of how positrons interact with surfaces and because of this we are now able to make much stronger fluxes of slow positrons. The higher beam strengths in turn are opening up new possibilities for experimentation on surfaces and solids and for studying the atomic physics of positronium and positron-molecule scattering at low energies. The lectures are intended to review some of the history of this subject and to outline the present state of our knowledge of experimentation with low-energy positron beams. (orig./TW)

  6. Natural gas in low energy house Zittau

    International Nuclear Information System (INIS)

    Maertens, L.; Koschack, A.

    1999-01-01

    This paper describes a low-energy house in Zittau, Germany. The house consists of two parts A and B. Part A is heated by means of gas boilers and condensed boilers, while part B is solar heated. Energy for heating and warming of tap water is an important part of the primary energy consumption in Germany. Therefore, one way of reducing the CO2 emissions is to reduce the heat losses of buildings through outer facades and air ventilation, to use regenerative energy sources, to use fuels with low CO2 emissivity like natural gas, and to install efficient heating- and hot water preparation systems. The low-energy house in Zittau is used for energy research

  7. LINAC4 low energy beam measurements

    CERN Document Server

    Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

    2012-01-01

    Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

  8. Enhancement mechanisms of low energy nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L. [Joint Institute for Nuclear Research, JINR, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation)

    2006-07-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong.

  9. Enhancement mechanisms of low energy nuclear reactions

    International Nuclear Information System (INIS)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L.

    2006-01-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong

  10. A Low-Energy Ring Lattice Design

    International Nuclear Information System (INIS)

    Cai, Yunhai

    2002-01-01

    The PEP-N project at SLAC [1] consists of a Very Low-Energy small electron Ring (VLER) that will collide with the low-energy 3.1 GeV positron beam (LER) of PEP-II, producing center-of-mass energies between the 1.1 GeV and the J/ψ. The beams will collide head-on and will be separated in the detector magnetic field which is part of the Interaction Region [2]. The IP β functions were chosen such as to optimize both luminosity and beam-beam tune shifts, while keeping the LER tune shifts small. This paper describes the lattice design of the VLER for the ''baseline'' at 500 MeV

  11. Food irradiation by low energy electrons

    International Nuclear Information System (INIS)

    Bird, J.R.

    1985-01-01

    For some special cases, the use of low energy electrons has advantages over the use of gamma-rays or higher energy electrons for the direct irradiation of food. These advantages arise from details of the interaction processes which are responsible for the production of physical, chemical and biological effects. Factors involved include depth of penetration, dose distribution, irradiation geometry, the possible production of radioactivity and costs

  12. Architectural Quality of Low Energy Houses

    DEFF Research Database (Denmark)

    Lauring, Michael; Marsh, Rob

    2008-01-01

    This paper expounds a systematic vocabulary concerning architectural quality in houses in general and low energy houses in particular. The vocabulary consists of nine themes. Inside each theme, examples are given of how to achieve both architectural quality and good environmental performance....... The purpose is to provide a useful tool for communication and argumentation in order to further integrated design of houses with good architecture and good environmental performance. ...

  13. Physics with ultra-low energy antiprotons

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Holzscheiter, M.H.; Hughes, R.J.

    1989-01-01

    The experimental observation that all forms of matter experience the same gravitational acceleration is embodied in the weak equivalence principle of gravitational physics. However no experiment has tested this principle for particles of antimatter such as the antiproton or the antihydrogen atom. Clearly the question of whether antimatter is in compliance with weak equivalence is a fundamental experimental issue, which can best be addressed at an ultra-low energy antiproton facility. This paper addresses the issue. 20 refs

  14. PHYSICS WITH ULTRA-LOW ENERGY ANTIPROTONS

    Energy Technology Data Exchange (ETDEWEB)

    M. HOLZSCHEITER

    2001-02-01

    In this report the author describes the current status of the antiproton deceleration (AD) facility at CERN, and highlights the physics program with ultra-low energy antiproton at this installation. He also comments on future possibilities provided higher intensity antiproton beams become available at Fermilab, and review possibilities for initial experiments using direct degrading of high energy antiprotons in material has been developed and proven at CERN.

  15. Workshop on low energy neutrino physics

    International Nuclear Information System (INIS)

    2009-01-01

    The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

  16. The low-energy experiment on EXOSAT

    International Nuclear Information System (INIS)

    Bleeker, J.A.M.

    1975-01-01

    The present concept of the Low-Energy-Experiment (LEE) for EXOSAT was proposed by a collaboration of the X-ray astronomy groups at Mullard Space Science Laboratories at University College London, the Space Research Laboratory at Utrecht and the Cosmic Ray Working Group at Leiden. In the following paragraphs the major characteristics of the instrumentation and the expected scientific return will be discussed. The summary comprises both the approved baseline configuration and the proposed option of a small imaging telescope

  17. FLSR - The Frankfurt low energy storage ring

    International Nuclear Information System (INIS)

    Stiebing, K.E.; Alexandrov, V.; Doerner, R.; Enz, S.; Kazarinov, N.Yu.; Kruppi, T.; Schempp, A.; Schmidt Boecking, H.; Voelp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-01-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut fuer Kernphysik der Johann Wolfgang Goethe-Universitaet Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  18. Low-energy scattering data for oxygen

    International Nuclear Information System (INIS)

    Kopecky, S.; Plompen, A.J.M.

    2014-01-01

    A survey of literature data of the scattering lengths of oxygen is performed, and these values are compared to low-energy precise total cross-section data. To check the quality of the data and the correctness of the relation between coherent scattering lengths and low-energy total cross-sections the situation is examined first for carbon. A value and uncertainty for the coherent scattering length of oxygen is recommended for use in future evaluations of 16 O. This coherent scattering length is fully consistent with the high-precision, low-energy total cross-section data. The consistency requires the use of a larger uncertainty than claimed in the most accurate cross-section papers. This larger uncertainty is nevertheless very small and well within the requirements of applications of this cross-section. The recommended value is b c ( 16 O) = 5.816±0.015 fm and the associated total cross-section for the neutron-energy range 0.5 to 2 000 eV is 3.765±0.025 b. The stated uncertainties are one standard deviation total uncertainty. (authors)

  19. Targeting Low-Energy Ballistic Lunar Transfers

    Science.gov (United States)

    Parker, Jeffrey S.

    2010-01-01

    Numerous low-energy ballistic transfers exist between the Earth and Moon that require less fuel than conventional transfers, but require three or more months of transfer time. An entirely ballistic lunar transfer departs the Earth from a particular declination at some time in order to arrive at the Moon at a given time along a desirable approach. Maneuvers may be added to the trajectory in order to adjust the Earth departure to meet mission requirements. In this paper, we characterize the (Delta)V cost required to adjust a low-energy ballistic lunar transfer such that a spacecraft may depart the Earth at a desirable declination, e.g., 28.5(white bullet), on a designated date. This study identifies the optimal locations to place one or two maneuvers along a transfer to minimize the (Delta)V cost of the transfer. One practical application of this study is to characterize the launch period for a mission that aims to launch from a particular launch site, such as Cape Canaveral, Florida, and arrive at a particular orbit at the Moon on a given date using a three-month low-energy transfer.

  20. The Low-Energy Neutrino Factory

    International Nuclear Information System (INIS)

    Brass, Alan; Geer, Steve; Ellis, Malcolm; Mena, Olga; Pascoli, Silvia

    2008-01-01

    To date most studies of Neutrino Factories have focused on facilities where the energy of the muon in the storage ring has been in the range of 25-50 GeV. In this paper we present a concept for a Low-Energy (∼ 4 GeV) neutrino factory. For baselines of O(1000 km), the rich oscillation pattern at low neutrino interaction energy (0.5 - ∼3 GeV) provides the unique performance of this facility with regard to its sensitivity to CP violation and the determination of the neutrino mass hierarchy. A unique neutrino detector is needed, however, in order to exploit this oscillation pattern. We will describe the basic accelerator facility, demonstrate the methodology of the analysis and give an estimate on how well the Low-Energy neutrino factory can measure θ 13 , CP violation and the mass hierarchy. We will also describe the detector concept that is used, show a preliminary analysis regarding its performance and indicate what R and D is still needed. Finally we will show how the Low-Energy neutrino factory could be a step towards an energy frontier muon collider.

  1. Photonuclear reactions in astrophysical p-process: Theoretical calculations and experiment simulation based on ELI-NP

    Science.gov (United States)

    Xu, Yi; Luo, Wen; Balabanski, Dimiter; Goriely, Stephane; Matei, Catalin; Tesileanu, Ovidiu

    2017-09-01

    The astrophysical p-process is an important way of nucleosynthesis to produce the stable and proton-rich nuclei beyond Fe which can not be reached by the s- and r-processes. In the present study, the astrophysical reaction rates of (γ,n), (γ,p), and (γ,α) reactions are computed within the modern reaction code TALYS for about 3000 stable and proton-rich nuclei with 12 Infrastructure-Nuclear Physics (ELI-NP) facility is being developed, which will provide the great opportunity to experimentally study the photonuclear reactions in p-process. Simulations of the experimental setup for the measurements of the photonuclear reactions 96Ru(γ,p) and 96Ru(γ,α) are performed. It is shown that the experiments of photonuclear reactions in p-process based on ELI-NP are quite promising.

  2. Dosimetry of low-energy beta radiation

    International Nuclear Information System (INIS)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

  3. Hydrogen-antihydrogen interactions at low energies

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Carr, J.M.; Zeman, V.

    1999-01-01

    The main cause of loss of trapped AH is due to collisions with H 2 and He. As a first step towards treating these reactions we are studying the interaction of AH with H. We have carried out variational calculations to determine an upper bound to the smallest internuclear distance at which the light particles are still bound to the nuclei. We are currently in the process of taking into account the motion of the nuclei. This will enable us to calculate cross-sections for low energy H-AH scattering

  4. The low energy booster project status

    International Nuclear Information System (INIS)

    Tuttle, G.W.

    1993-05-01

    In order to achieve the required injection momentum, the Superconducting Super Collider (SSC) has an accelerator chain comprised of a Linear Accelerator and three synchrotrons. The Low Energy Booster (LEB) is the first synchrotron in this chain. The LEB project has made significant progress in the development of major subsystems and conventional construction. This paper briefly reviews the performance requirements of the LEB and describes significant achievements in each of the major subsystem areas. Highlighted among these achievements are the LEB foreign collaborations with the Budker Institute of Nuclear Physics (BINP) located in Novosibirsk, Russia

  5. Low energy constraints and scalar leptoquarks⋆

    Directory of Open Access Journals (Sweden)

    Fajfer Svjetlana

    2014-01-01

    Full Text Available The presence of a colored weak doublet scalar state with mass below 1 TeV can provide an explanation of the observed branching ratios in B → D(∗τντ decays. Constraints coming from Z → bb̄, muon g − 2, lepton flavor violating decays are derived. The colored scalar is accommodated within 45 representation of SU(5 group of unification. We show that presence of color scalar can improve mass relations in the up-type quark sector mass. Impact of the colored scalar embedding in 45-dimensional representation of SU(5 on low-energy phenomenology is also presented.

  6. Round Gating for Low Energy Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things....... Additionally, we discuss how to needed gating wave can be generated. Experimental results show that our technique is able to reduce the energy consumption in most block ciphers by over 60% while incurring only a minimal overhead in hardware....

  7. Low-energy phenomenological chiral Lagrangians

    International Nuclear Information System (INIS)

    Cavopol, A.V.

    1987-01-01

    We develop a phenomenological Lagrangian that satisfies the requirements of the so called alternative schemes designed to model low energy meson phenomenology. Linear and nonlinear σ type Lagrangians and symmetry breaking schemes are used to describe pions that exhibit masses proportional to the square of the symmetry breaking term's coefficient, ε. (m π 2 ∼ 0(ε 2 )). The invariance of the theory under coordinate dependent transformations is achieved by introducing gauge fields for both linear and nonlinear Lagrangians. Finally, analogies between the minimal symmetry breaking terms in Quantum Electrodynamics and in our phenomenological lagrangians are used to generate a discussion of the quark-pion mass dependence indicated by the model

  8. FLSR - The Frankfurt low energy storage ring

    Science.gov (United States)

    Stiebing, K. E.; Alexandrov, V.; Dörner, R.; Enz, S.; Kazarinov, N. Yu.; Kruppi, T.; Schempp, A.; Schmidt Böcking, H.; Völp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-02-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut für Kernphysik der Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  9. The relation between the photonuclear E1 sum rule and the effective orbital g-factor

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, Wolfgang E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Arima, Akito

    2004-05-17

    The connection between the enhancement factor (1+{kappa}) of the photonuclear E1 sum rule and the orbital angular momentum g-factor (g{sub l}) of a bound nucleon is investigated in the framework of the Landau-Migdal theory for isospin asymmetric nuclear matter. Special emphasis is put on the role of gauge invariance to establish the {kappa}-g{sub l} relation. By identifying the physical processes which are taken into account in {kappa} and g{sub l}, the validity and limitations of this relation will be discussed. The connections to the collective excitations and to nuclear Compton scattering are also shown.

  10. Studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region using microtrons

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Nguyen Van Do; Nguyen Khac Thi; Truong Thi An; Nguyen Ngoc Son

    2004-01-01

    Microtrons are accelerators of electrons and are simultaneous source of Bremsstrahlung photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam. Though very modest, microtrons are very useful for developing countries such as Vietnam in both fundamental and applied physics research. During the recent years by using the above mentioned MT - 17 and microtrons from other institutes we have carried out different investigation. In this report we present some results obtained in the studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region. (author)

  11. Measurement of neutron spectra for photonuclear reaction with linearly polarized photons

    Directory of Open Access Journals (Sweden)

    Kirihara Yoichi

    2017-01-01

    Full Text Available Spectra of neutrons produced by a photonuclear reaction from a 197Au target were measured using 16.95 MeV linearly and circularly polarized photon beams at NewSUBARU-BL01 using a time-of-flight method. The difference in the neutron spectra between the cases of a linearly and circularly polarized photon was measured. The difference in the neutron yield increased with the neutron energy and was approximately threefold at the maximum neutron energy. In a direction perpendicular to that of the linear polarization, the neutron yields decreased as the neutron energy increased.

  12. Low-energy QCD and ultraviolet renormalons

    International Nuclear Information System (INIS)

    Peris, S.

    1997-01-01

    We discuss the contribution of ultraviolet (UV) renormalons in QCD to two-point functions of quark current operators. This explicitly includes effects due to the exchange of one renormalon chain as well as two chains. It is shown that, when the external Euclidean momentum of the two-point functions becomes smaller than the scale Λ L associated with the Landau singularity of the QCD one-loop running coupling constant, the positions of the UV renormalons in the Borel plane become true singularities in the integration range of the Borel transform. This introduces ambiguities in the evaluation of the corresponding two-point functions. The ambiguities associated with the leading UV renormalon singularity are of the same type as the contribution due to the inclusion of dimension d=6 local operators in a low-energy effective Lagrangian valid at scales smaller than Λ L . We then discuss the inclusion of an infinite number of renormalon chains and argue that the previous ambiguity hints at a plausible approximation scheme for low-energy QCD, resulting in an effective Lagrangian similar to the one of the extended Nambu-Jona-Lasinio (ENJL) model of QCD at large N c . (orig.)

  13. Analysis of low energy beta-emitters

    International Nuclear Information System (INIS)

    Murphy, D.L.

    1979-10-01

    A survey was made of the instruments used for the determination of low energy beta radioactivity. Techniques commonly used are gas flow proportional counting, liquid scintillation counting, solid scintillation counting, and internal ionization chamber counting, solid state detector counting, and radiochemical separation followed by counting using one of the preceeding techniques. The first four techniques were examined and compared with each other. The sensitivities of the techniques were compared on the basis of the detection limits quoted for instruments described in the technical and reviewed literature. The detection limits were then related to the occupational and public individual maximum levels for air and water. Attention is focused primarily on the continuous monitoring of air for 3 H and 85 Kr, a medium energy β-emitter. It is clear that several continuous air monitoring instruments are readily available for measuring low energy β concentrations, even in presence of certain other activity, at occupational levels. However, these instruments do not typically have sensitivities comparable to the public individual levels. Moreover, their capabilities for giving results in real time and for differentiating among the radionuclides actually present is limited

  14. Low energy accelerators for research and applications

    International Nuclear Information System (INIS)

    Bhandari, R.K.

    2013-01-01

    Charged particle accelerators are instruments for producing a variety of radiations under controlled conditions for basic and applied research as well as applications. They have helped enormously to study the matter, atoms, nuclei, sub-nuclear particles and their constituents, forces involved in the related phenomena etc. No other man-made instrument has been so effective in such studies as the accelerator. The large accelerator constructed so far is the Large Hadron Collider (LHC) housed in a tunnel of 27 km circumference, while a small accelerator can fit inside a room. Small accelerators accelerate charged particles such as electrons, protons, deuterons, alphas and, in general ions to low energy, generally, below several MeV. These particle beams are used for studies in nuclear astrophysics, atomic physics, material science, surface physics, bio sciences etc. They are used for ion beam analysis such as RBS, PIXE, NRA, AMS, CPAA etc. More importantly, the ion beams have important industrial applications like ion implantation, surface modification, isotope production etc. while electron beams are used for material processing, material modification, sterilization, food preservation, non destructive testing etc. In this talk, role of low energy accelerators in research and industry as well as medicine will be discussed. (author)

  15. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2010-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187. We describe here research into low-energy nuclear reactions and structure. The statistical properties of nuclei have been studied by measuring level densities and also calculating them theoretically. Our approach of measuring level densities via evaporation spectra is able to reach a very wide range of nuclei by using heavy ion beams (we expect to develop experiments using radioactive beams in the near future). Another focus of the program has been on γ-ray strength functions. These clearly impact nuclear reactions, but they are much less understood than corresponding transmission coefficients for nucleons. We have begun investigations of a new approach, using γ-γ coincidences following radiative capture. Finally, we have undertaken several measurements of cross sections involving light nuclei which are important in various applications. The 9 Be(α,n) and B(d,n) reactions have been measured at Ohio University, while neutron-induced reactions have been measured at Los Alamos (LANSCE).

  16. Low energy theorems of hidden local symmetries

    International Nuclear Information System (INIS)

    Harada, Masayasu; Kugo, Taichiro; Yamawaki, Koichi.

    1994-01-01

    We prove to all orders of the loop expansion the low energy theorems of hidden local symmetries in four-dimensional nonlinear sigma models based on the coset space G/H, with G and H being arbitrary compact groups. Although the models are non-renormalizable, the proof is done in an analogous manner to the renormalization proof of gauge theories and two-dimensional nonlinear sigma models by restricting ourselves to the operators with two derivatives (counting a hidden gauge boson field as one derivative), i.e., with dimension 2, which are the only operators relevant to the low energy limit. Through loop-wise mathematical induction based on the Ward-Takahashi identity for the BRS symmetry, we solve renormalization equation for the effective action up to dimension-2 terms plus terms with the relevant BRS sources. We then show that all the quantum corrections to the dimension-2 operators, including the finite parts as well as the divergent ones, can be entirely absorbed into a re-definition (renormalization) of the parameters and the fields in the dimension-2 part of the tree-level Lagrangian. (author)

  17. Low Energy Nuclear Reactions: 2007 Update

    Science.gov (United States)

    Krivit, Steven B.

    2007-03-01

    This paper presents an overview of low energy nuclear reactions, a subset of the field of condensed matter nuclear science. Condensed matter nuclear science studies nuclear effects in and/or on condensed matter, including low energy nuclear reactions, an entirely new branch of science that gained widespread attention and notoriety beginning in 1989 with the announcement of a previously unrecognized source of energy by Martin Fleischmann and Stanley Pons that came to be known as cold fusion. Two branches of LENR are recognized. The first includes a set of reactions like those observed by Fleischmann and Pons that use palladium and deuterium and yield excess heat and helium-4. Numerous mechanisms have been proposed to explain these reactions, however there is no consensus for, or general acceptance of, any of the theories. The claim of fusion is still considered speculative and, as such, is not an ideal term for this work. The other branch is a wide assortment of nuclear reactions that may occur with either hydrogen or deuterium. Anomalous nuclear transmutations are reported that involve light as well as heavy elements. The significant questions that face this field of research are: 1) Are LENRs a genuine nuclear reaction? 2) If so, is there a release of excess energy? 3) If there is, is the energy release cost-effective?

  18. Low energy cyclotron for radiocarbon dating

    International Nuclear Information System (INIS)

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14 C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14 C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14 C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

  19. Experimental perspectives in low energy lepton physics

    International Nuclear Information System (INIS)

    Fiorini, E.

    1986-01-01

    Low energy nuclear physics has been and is going to be an essential tool for the study of weak interaction and neutrino physics. The use of the atomic nucleus as a ''microlaboratory'' with well defined quantum numbers is undoubtedly going to yield important and sometimes perhaps unexpected results on the symmetry laws governing the subnuclear world. These searches are however very hard experimentally and the bottleneck on obtaining more stringent results only rarely depends on the need of large and expensive apparatuses as those used in high energy physics: more limiting are technical difficulties. The author believes therefore that a real break-through to overcome the present experimental limitations can only be obtained with totally new and sometime ''non canonical'' technical approaches. This paper is an admittedly incomplete discussion of some of them. The author considers separately searches for rare decays, detection of low energy neutrinos and measurements of the neutrino mass, even if some of these new techniques are common to more than one of these subjects

  20. Beam diagnostics for low energy beams

    Directory of Open Access Journals (Sweden)

    J. Harasimowicz

    2012-12-01

    Full Text Available Low-energetic ion and antimatter beams are very attractive for a number of fundamental studies. The diagnostics of such beams, however, is a challenge due to low currents down to only a few thousands of particles per second and significant fraction of energy loss in matter at keV beam energies. A modular set of particle detectors has been developed to suit the particular beam diagnostic needs of the ultralow-energy storage ring (USR at the future facility for low-energy antiproton and ion research, accommodating very low beam intensities at energies down to 20 keV. The detectors include beam-profile monitors based on scintillating screens and secondary electron emission, sensitive Faraday cups for absolute intensity measurements, and capacitive pickups for beam position monitoring. In this paper, the design of all detectors is presented in detail and results from beam measurements are shown. The resolution limits of all detectors are described and options for further improvement summarized. Whilst initially developed for the USR, the instrumentation described in this paper is also well suited for use in other low-intensity, low-energy accelerators, storage rings, and beam lines.

  1. Occupant satisfaction with new low-energy houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Jensen, Ole Michael; Kristensen, Lars

    2012-01-01

    The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low-energy ho......The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low......-energy houses. The purpose was to study occupant satisfaction with new low-energy houses concerning i.a. the perceived indoor climate and the technical installations for heating and ventilation. The survey showed an overall satisfaction with the new low-energy houses, but also that there were problems...... occupant satisfaction in existing and future low-energy houses are given....

  2. Coherent and incoherent J /ψ photonuclear production in an energy-dependent hot-spot model

    Science.gov (United States)

    Cepila, J.; Contreras, J. G.; Krelina, M.

    2018-02-01

    In a previous publication, we have presented a model for the photoproduction of J /ψ vector mesons off protons, where the proton structure in the impact-parameter plane is described by an energy-dependent hot-spot profile. Here we extend this model to study the photonuclear production of J /ψ vector mesons in coherent and incoherent interactions of heavy nuclei. We study two methods to extend the model to the nuclear case: using the standard Glauber-Gribov formalism and using geometric scaling to obtain the nuclear saturation scale. We find that the incoherent cross section changes sizably with the inclusion of subnucleonic hot spots and that this change is energy dependent. We propose to search for this behavior by measuring the ratio of the incoherent to coherent cross sections at different energies. We compare the results of our model to results from the Relativistic Heavy-Ion Collider (RHIC) and from run 1 at the Large Hadron Collider (LHC), finding satisfactory agreement. We also present predictions for the LHC at the new energies reached in run 2. The predictions include J /ψ production in ultraperipheral collisions, as well as the recently observed photonuclear production in peripheral collisions.

  3. Nuclear Computational Low Energy Initiative (NUCLEI)

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Sanjay K. [University of Washington

    2017-08-14

    This is the final report for University of Washington for the NUCLEI SciDAC-3. The NUCLEI -project, as defined by the scope of work, will develop, implement and run codes for large-scale computations of many topics in low-energy nuclear physics. Physics to be studied include the properties of nuclei and nuclear decays, nuclear structure and reactions, and the properties of nuclear matter. The computational techniques to be used include Quantum Monte Carlo, Configuration Interaction, Coupled Cluster, and Density Functional methods. The research program will emphasize areas of high interest to current and possible future DOE nuclear physics facilities, including ATLAS and FRIB (nuclear structure and reactions, and nuclear astrophysics), TJNAF (neutron distributions in nuclei, few body systems, and electroweak processes), NIF (thermonuclear reactions), MAJORANA and FNPB (neutrino-less double-beta decay and physics beyond the Standard Model), and LANSCE (fission studies).

  4. Redesign of a Low Energy Probe Head

    CERN Document Server

    Rao, Yi-Nong; Ries, Thomas

    2005-01-01

    The present situation of the low energy probe LE2 in TRIUMF cyclotron is that the thickness of the finger 5 is uniform over a radial length of 3.25 inch and its weight which amounts to ~447 g is affecting its re-circulating ball mechanism and causing it to fall below the median plane over its range of movement. We therefore re-design it in order to reduce its weight. First, we made simulations and determined the optimum thickness of the probe head vs its radial length. These simulation results are found to be in good agreement with experimental measurements made. Finally, we calculated the temperature rise caused by the beam power dumped on the probe, and figured out the maximum current of beam that can be dumped on the finger.

  5. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  6. Low-energy pion-nucleon scattering

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Ai, L.; Kaufmann, W.B.

    1998-01-01

    An analysis of low-energy charged pion-nucleon data from recent π ± p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f 2 =0.0756±0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P 31 and P 13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the Σ term. Off-shell amplitudes are also provided. copyright 1998 The American Physical Society

  7. Low energy ion-molecule reactions

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, J.M. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project is concerned with elucidating the dynamics of elementary ion-molecule reactions at collision energies near and below 1 eV. From measurements of the angular and energy distributions of the reaction products, one can infer intimathe details about the nature of collisions leading to chemical reaction, the geometries and lifetimes of intermediate complexes that govern the reaction dynamics, and the collision energy dependence of these dynamical features. The author employs crossed-beam low energy mass spectrometry technology developed over the last several years, with the focus of current research on proton transfer and hydrogen atom transfer reactions of te O{sup {minus}} ion with species such as HF, H{sub 2}O, and NH{sub 3}.

  8. Knowledge from the low energy results

    International Nuclear Information System (INIS)

    Gosset, J.

    1988-01-01

    Before being used at very high energies, in order to search for the quark-gluon plasma, nucleus-nucleus central collisions have been studied at low energy, between about 20 MeV per nucleon and 10 GeV per nucleon, with the same objective to explore the phase diagram of nuclear matter, but in a regime where both temperature and energy are too small for plasma formation. Approaching this very complicated problem of nuclear physics led to many difficulties. They are first reviewed, and various means developed in order to solve them are considered. These difficulties are then detailed along discussions about temperature and nuclear collective flow. Temperature is a concept which is commonly used but also a quantity which is difficult to measure. Nuclear collective flow is a very interesting compression effect; it has been observed experimentally after being predicted theoretically, but its interpretation in terms of the nuclear matter equation of state remains quite difficult [fr

  9. Windows in Low Energy Houses. Size Matters

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Mari-Louise

    2004-06-01

    A generally accepted way of building passive houses has been to have small windows facing north and a large glass facade to the south. This is to minimize losses on the north side while gaining as much solar heat as possible on the south. In spring 2001, twenty terraced houses were built outside Goeteborg partly in this way. The indoor temperature is kept at a comfortable level by passive methods, using solar gains and internal gains from household appliances and occupants. Heat losses are very low, since the building envelope is well insulated and since modern coated triple-glazed windows have been installed. The purpose of this work is to investigate how decreasing the window size facing south and increasing the window size facing north in low energy houses will influence the energy consumption and maximum power needed to keep the indoor temperature between 23 and 26 deg C. Different climates and orientations have been investigated and so have the influence of occupancy and window type. A dynamic building simulation tool, DEROB, has been used and the simulations indicate an extremely low energy demand for the houses. The results show that the size of the energy efficient windows does not have a major influence on the heating demand in winter, but is of relevant signification looking at the cooling need in summer. This indicates that instead of the traditional technique of building passive houses it is possible to enlarge the window area facing north and get better lighting conditions. To decrease the energy need for cooling, there is an optimal window size facing south that is smaller than the original size of the investigated buildings.

  10. Low energy demonstration accelerator technical area 53

    International Nuclear Information System (INIS)

    1996-01-01

    As part of the Department of Energy's (DOE) need to maintain the capability of producing tritium in support of its historic and near-term stewardship of the nation's nuclear weapons stockpile, the agency has recently completed a Programmatic Environmental Impact Statement for Tritium Supply and Recycling. The resulting Record of Decision (ROD) determined that over the next three years the DOE would follow a dual-track acquisition strategy that assures tritium production for the nuclear weapon stockpile in a rapid, cost effective, and safe manner. Under this strategy the DOE will further investigate and compare two options for producing tritium: (1) purchase of an existing commercial light-water reactor or irradiation services with an option to purchase the reactor for conversion to a defense facility; and (2) design, build, and test critical components of a system for accelerator production of tritium (APT). The final decision to select the primary production option will be made by the Secretary of Energy in the October 1998 time frame. The alternative not chosen as the primary production method, if feasible, would be developed as a back-up tritium supply source. This Environmental Assessment (EA) analyzes the potential environmental effects that would be expected to occur if the DOE were to design, build, and test critical prototypical components of the accelerator system for tritium production, specifically the front-end low-energy section of the accelerator, at Los Alamos National Laboratory. The Low Energy Demonstration Accelerator (LEDA) would be incrementally developed and tested in five separate stages over the next seven years. The following issues were evaluated for the proposed action: utility demands, air, human health, environmental restoration, waste management, transportation, water, threatened and endangered species, wetlands, cultural resources, and environmental justice

  11. Capture and photonuclear reaction rates involving charged-particles: Impacts of nuclear ingredients and future measurement on ELI-NP

    Directory of Open Access Journals (Sweden)

    Xu Y.

    2018-01-01

    Full Text Available The astrophysical p-process is an important way of nucleosynthesis to produce the stable and proton-rich nuclei beyond Fe which can not be reached by the s- and r-processes. In the present study, the impact of nuclear ingredients, especially the nuclear potential, level density and strength function, to the astrophysical re-action rates of (p,γ, (α,γ, (γ,p, and (γ,α reactions are systematically studied. The calculations are performed basad on the modern reaction code TALYS for about 3000 stable and proton-rich nuclei with 12≤Z≤110. In particular, both of the Wood-Saxon potential and the microscopic folding potential are taken into account. It is found that both the capture and photonuclear reaction rates are very sensitive to the nuclear potential, thus the better determination of nuclear potential would be important to reduce the uncertainties of reaction rates. Meanwhile, the Extreme Light Infrastructure-Nuclear Physics (ELI-NP facility is being developed, which will provide the great opportunity to experimentally study the photonuclear reactions in p-process. Simulations of the experimental setup for the measurements of the photonuclear reactions 96Ru(γ,p and 96Ru(γ,α are performed. It is shown that the experiments of photonuclear reactions in p-process based on ELI-NP are quite promising.

  12. Capture and photonuclear reaction rates involving charged-particles: Impacts of nuclear ingredients and future measurement on ELI-NP

    Science.gov (United States)

    Xu, Y.; Goriely, S.; Balabanski, D. L.; Chesnevskaya, S.; Guardo, G. L.; La Cognata, M.; Lan, H. Y.; Lattuada, D.; Luo, W.; Matei, C.

    2018-05-01

    The astrophysical p-process is an important way of nucleosynthesis to produce the stable and proton-rich nuclei beyond Fe which can not be reached by the s- and r-processes. In the present study, the impact of nuclear ingredients, especially the nuclear potential, level density and strength function, to the astrophysical re-action rates of (p,γ), (α,γ), (γ,p), and (γ,α) reactions are systematically studied. The calculations are performed basad on the modern reaction code TALYS for about 3000 stable and proton-rich nuclei with 12≤Z≤110. In particular, both of the Wood-Saxon potential and the microscopic folding potential are taken into account. It is found that both the capture and photonuclear reaction rates are very sensitive to the nuclear potential, thus the better determination of nuclear potential would be important to reduce the uncertainties of reaction rates. Meanwhile, the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) facility is being developed, which will provide the great opportunity to experimentally study the photonuclear reactions in p-process. Simulations of the experimental setup for the measurements of the photonuclear reactions 96Ru(γ,p) and 96Ru(γ,α) are performed. It is shown that the experiments of photonuclear reactions in p-process based on ELI-NP are quite promising.

  13. Solving The Longstanding Problem Of Low-Energy Nuclear Reactions At the Highest Microscopic Level - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-22

    A 2011 DOE-NP Early Career Award (ECA) under Field Work Proposal (FWP) SCW1158 supported the project “Solving the Long-Standing Problem of Low-Energy Nuclear Reactions at the Highest Microscopic Level” in the five-year period from June 15, 2011 to June 14, 2016. This project, led by PI S. Quaglioni, aimed at developing a comprehensive and computationally efficient framework to arrive at a unified description of structural properties and reactions of light nuclei in terms of constituent protons and neutrons interacting through nucleon-nucleon (NN) and three-nucleon (3N) forces. Specifically, the project had three main goals: 1) arriving at the accurate predictions for fusion reactions that power stars and Earth-based fusion facilities; 2) realizing a comprehensive description of clustering and continuum effects in exotic nuclei, including light Borromean systems; and 3) achieving fundamental understanding of the role of the 3N force in nuclear reactions and nuclei at the drip line.

  14. Low energy electron scattering from fuels

    International Nuclear Information System (INIS)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M.

    2011-01-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  15. Low energy electron scattering from fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M. [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil). Dept. de Fisica; Yates, Brent; Hong, Ling; Khakoo, Murtadha A. [California State University at Fullerton, CA (US). Physics Department; Bettega, Marcio H.F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Costa, Romarly F. da [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Lima, Marco A.P. [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE/CNPEM), Campinas, SP (Brazil)

    2011-07-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  16. Low energy atom-atom collisions

    International Nuclear Information System (INIS)

    Child, M.S.

    1980-01-01

    The semiclassical theory of atom-atom potential scattering and of low energy inelastic atom-atom scattering is reviewed. Particular attention is given to the origin and interpretation of rainbow structure, diffraction oscillations and exchange oscillations in the potential scattering differential cross-section, and to the glory structure and symmetry oscillations in the integral cross-section. Available methods for direct inversion of the cross-section data to recover the potential are reviewed in some detail. The theory of non-adiabatic transitions is introduced by a short discussion of interaction mechanisms and of diabetic and adiabatic representations. Analytical S matrix elements are presented for two state curve-crossing (Landau-Zener-Stuckelberg), Demkov and Nikitin models. The relation between Stuckelberg oscillations in the S matrix and in the differential cross-section is discussed in terms of interference between trajectories belonging to two different classical deflection functions. The energy dependences of the inelastic integral cross-section for curve-crossing and Demkov type transitions are also discussed. Finally the theory is reviewed in relation to a recent close-coupled study of fine structure transitions in F( 2 P) + Xe( 2 S) scattering

  17. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2006-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  18. Low Energy Desalination Using Battery Electrode Deionization

    KAUST Repository

    Kim, Taeyoung

    2017-09-21

    New electrochemical technologies that use capacitive or battery electrodes are being developed to minimize energy requirements for desalinating brackish waters. When a pair of electrodes is charged in capacitive deionization (CDI) systems, cations bind to the cathode and anions bind to the anode, but high applied voltages (>1.2 V) result in parasitic reactions and irreversible electrode oxidation. In the battery electrode deionization (BDI) system developed here, two identical copper hexacyanoferrate (CuHCF) battery electrodes were used that release and bind cations, with anion separation occurring via an anion exchange membrane. The system used an applied voltage of 0.6 V, which avoided parasitic reactions, achieved high electrode desalination capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes between CuHCF electrodes (up to three anion and two cation exchange membranes) reduced energy consumption to only 0.02 kWh/m3 (approximately an order of magnitude lower than values reported for CDI), for an influent desalination similar to CDI (25 mM decreased to 17 mM). These results show that BDI could be effective as a very low energy method for brackish water desalination.

  19. Operating Characteristics of the low energy accelerator

    International Nuclear Information System (INIS)

    Abd El-Baki, M.M.; Abd El-Rahman, M.M.

    2000-01-01

    The main purpose of this work is to describe the construction and operation of low energy accelerator with energy in the range from (zero to 100 KeV.). This accelerator includes an ion source of the cold cathode penning type (with pierce geometry for ion beam extraction), an accelerating tube (with 8 electrodes) and faraday cup for measuring ion current. A vacuum system which gives vacuum of the order 3.0 x 10 8 torr is used. A palladium tube is used to supply the source with pure hydrogen atoms. It was possible to operate this accelerator with an energy 50 KeV. at minimum hydrogen pressure. 6.3 x 10 6 torr. The total resistance applied between the accelerating electrodes R T = 31.5 M OMEGA. These data includes the influence of the pressure in the accelerating tube, the magnetic field of the ion source, the extraction potential and the accelerating potential on the collector ion current. It was possible to accelerate protons with an energy 50 KeV with current about 100 MU A at pressure 6.3 x 10 6 Torr, the source magnetic field + 1100 gauss (I B = 2A), the current = 0.4 A and the extraction potential = 10 K. V

  20. Low energy spin excitations in chromium metal

    International Nuclear Information System (INIS)

    Pynn, R.; Azuah, R.T.; Stirling, W.G.

    1997-01-01

    Neutron scattering experiments with full polarization analysis have been performed with a single crystal of chromium to study the low-energy spin fluctuations in the transverse spin density wave (TSDW) state. A number of remarkable results have been found. Inelastic scattering observed close to the TSDW satellite positions at (1 ± δ,0,0) does not behave as expected for magnon scattering. In particular, the scattering corresponds to almost equally strong magnetization fluctuations both parallel and perpendicular to the ordered moments of the TSDW phase. As the Neel temperature is approached from below, scattering at the commensurate wavevector (1,0,0) increases in intensity as a result of critical scattering at silent satellites (1,0, ± δ) being included within the spectrometer resolution function. This effect, first observed by Sternlieb et al, does not account for all of the inelastic scattering around the (1,0,0) position, however, Rather, there are further collective excitations, apparently emanating from the TSDW satellites, which correspond to magnetic fluctuations parallel to the ordered TSDW moments. These branches have a group velocity that is close to that of (1,0,0) longitudinal acoustic (LA) phonons, but assigning their origin to magneto-elastic scattering raises other unanswered questions

  1. Low energy pion-16O scattering

    International Nuclear Information System (INIS)

    Wafelbakker, C.K.

    1981-01-01

    In spite of some outward appearances, the modern microscopic theories of the pion-nucleus (πA) interaction are not fundamentally very different from each other. They can all be derived from the same source, multiple-scattering theory. They all treat the first-order optical potential in a comparatively detailed way and in all of them it is necessary to incorporate higher-order effects in general and pion-annihilation in particular phenomenologically. Basically the same physical features can be embodied in all of them. The presentation of the theoretical scheme underlying the present thesis is designed to stress this conceptual unity of current πA theory. In this thesis the methods developed by De Kam to incorporate Pauli- and binding-corrections to the impulse-approximation first-order optical potential for 4 He are extended to a more complicated nucleus, 16 O, for the first time. In concreto two situations are considered: π- 16 O scattering at energies below nucleon-knockout threshold (13.5 MeV) - 7 and 12 MeV - and at energies 40 and 49.7 MeV, above nucleon-knockout threshold but still well within the low-energy region. (Auth.)

  2. Low energy scattering with a nontrivial pion

    International Nuclear Information System (INIS)

    Fariborz, Amir H.; Jora, Renata; Schechter, Joseph

    2007-01-01

    An earlier calculation in a generalized linear sigma model showed that the well-known current algebra formula for low energy pion-pion scattering held even though the massless Nambu Goldstone pion contained a small admixture of a two-quark two-antiquark field. Here we turn on the pion mass and note that the current algebra formula no longer holds exactly. We discuss this small deviation and also study the effects of a SU(3) symmetric quark mass type term on the masses and mixings of the eight SU(3) multiplets in the model. We calculate the s-wave scattering lengths, including the beyond current algebra theorem corrections due to the scalar mesons, and observe that the effect of the scalar mesons is to improve the agreement with experiment. In the process, we uncover the way in which linear sigma models give controlled corrections (due to the presence of scalar mesons) to the current algebra scattering formula. Such a feature is commonly thought to exist only in the nonlinear sigma model approach

  3. DOD low energy model installation program

    International Nuclear Information System (INIS)

    Fournier, D.F. Jr.

    1993-01-01

    The Model Low Energy Installation Program is a demonstration of an installation-wide, comprehensive energy conservation program that meets the Department of Defense (DoD) energy management goals of reducing energy usage and costs by at least 20%. It employs the required strategies for meeting these goals, quantifies the environmental compliance benefits resulting from energy conservation and serves as a prototype for DoD wide application. This project will develop both analysis tools and implementation procedures as well as demonstrate the effectiveness of a comprehensive, coordinated energy conservation program based on state-of-the-art technologies. A military installation is in reality a small to medium sized city. It generally has a complete utilities infrastructure including water supply and distribution, sewage collection and treatment, electrical supply and distribution, central heating and cooling plants with thermal distribution, and a natural gas distribution system. These utilities are quite extensive and actually consume about 10-15% of the energy on the facility not counting the energy going into the central plants

  4. Study on the application of low energy U-window

    International Nuclear Information System (INIS)

    Li Binghai; Liu Shikai; Chen Guosheng

    2012-01-01

    For using the low energy U-window information, based on the theory and experiment, the advantage of identifying the subtle anomaly that the low energy U-window information has given is discussed, the method of drawing the low energy U-window information is stated; a method of calibration and obtaining the calibration parameters was developed which was applied to Dongsheng region. The result indicated that the anomaly of low energy U-window information upon known field is more easy identified by comparing with the standard three windows U-window information, which proved the practicability of the method of low energy U-windows information. (authors)

  5. New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field

    International Nuclear Information System (INIS)

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

    2006-01-01

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system. (author)

  6. New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

    Science.gov (United States)

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

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

  7. Low energy nuclear reactions: 2007 update

    International Nuclear Information System (INIS)

    Krivit, S. B.

    2007-01-01

    Introduction: This paper presents an overview of the field of low energy nuclear reactions (LENR), a branch of condensed matter nuclear science. It explains some of the various terminologies that have been used to describe this field since it debuted as 'cold fusion' in 1989. The paper also reviews some of the most interesting news and developments regarding low energy nuclear reaction experiments and theory, and some of the sociological and political trends that have affected the field over the last 18 years. It concludes with a list of resources and information for scientists, journalists and decision makers. Understanding the Nature of the Reactions The worldwide LENR research effort includes 200 researchers in 13 nations. Over the last 18 years, 12 international conferences have been held, as well as 7 regional conferences in Italy, 14 in Russia and 7 in Japan. The significant questions that face this field of research are: a) Are LENRs a genuine nuclear reaction? b) If so, is there a release of excess energy? and c) Are transmutations possible? If the answers to these questions turn out to be positive, the next questions will be: d) Is the energy release cost-effective? and e) Are the transmutations useful? Despite the fact that repeatability and reproducibility are challenging, the required parameters for achieving the excess heat effect are well understood. First, a high atomic loading ratio of D into Pd is required. In most conditions, 0.90 is the minimum threshold required to produce an excess heat effect. Second, a high electrical current density in the cathode is needed, 250 mA/cm 2 under most conditions. The third requirement is for some kind of dynamic trigger to impose a deuterium flux in, on or around the cathode. The challenge that researchers face is how to achieve these conditions. Some of the Most Interesting Research Developments Work by Stanislaw Szpak, Pamela Boss and Frank Gordon at the U.S. Navy's SPAWAR Systems Center in San Diego has

  8. Low-energy scattering on the lattice

    International Nuclear Information System (INIS)

    Bour Bour, Shahin

    2014-01-01

    In this thesis we present precision benchmark calculations for two-component fermions in the unitarity limit using an ab initio method, namely Hamiltonian lattice formalism. We calculate the ground state energy for unpolarized four particles (Fermi gas) in a periodic cube as a fraction of the ground state energy of the non-interacting system for two independent representations of the lattice Hamiltonians. We obtain the values 0.211(2) and 0.210(2). These results are in full agreement with the Euclidean lattice and fixed-node diffusion Monte Carlo calculations. We also give an expression for the energy corrections to the binding energy of a bound state in a moving frame. These corrections contain information about the mass and number of the constituents and are topological in origin and will have a broad applications to the lattice calculations of nucleons, nuclei, hadronic molecules and cold atoms. As one of its applications we use this expression and determine the low-energy parameters for the fermion dimer elastic scattering in shallow binding limit. For our lattice calculations we use Luescher's finite volume method. From the lattice calculations we find κa fd =1.174(9) and κr fd =-0.029(13), where κ represents the binding momentum of dimer and a fd (r fd ) denotes the scattering length (effective-range). These results are confirmed by the continuum calculations using the Skorniakov-Ter-Martirosian integral equation which gives 1.17907(1) and -0.0383(3) for the scattering length and effective range, respectively.

  9. Low energy x-ray spectrometer

    International Nuclear Information System (INIS)

    Woodruff, W.R.

    1981-01-01

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

  10. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  11. An online low energy gaseous ion source

    International Nuclear Information System (INIS)

    Jin Shuoxue; Guo Liping; Peng Guoliang; Zhang Jiaolong; Yang Zheng; Li Ming; Liu Chuansheng; Ju Xin; Liu Shi

    2010-01-01

    The accumulation of helium and/or hydrogen in nuclear materials may cause performance deterioration of the materials. In order to provide a unique tool to investigate the He-and/or H-caused problems, such as interaction of helium with hydrogen and defects, formation of gas bubbles and its evolution, and the related effects, we designed a low energy (≤ 20 keV) cold cathode Penning ion source, which will be interfaced to a 200 kV transmission electron microscope (TEM), for monitoring continuously the evolution of micro-structure during the He + or H + ion implantation. Studies on discharge voltage-current characteristics of the ion source, and extraction and focusing of the ion beam were performed. The ion source works stably with 15-60 mA of the discharge current.Under the gas pressure of 5 x 10 -3 Pa and 1.5 x 10 -2 Pa, the discharge voltage are about 380 V and 320 V, respectively. The extracted ion current under lower gas pressure is greater than that under higher gas pressure, and it increases with the discharge current and extraction voltage. The ion lens consisting of three equal-diameter metal cylinder focus the ion beam effectively, so that the beam density at the 150 cm away from the lens exit increases by a over one order of magnitude. For ion beams of around 10 keV, the measured beam density is about 200 nA · cm -2 , which is applicable for ion implantation and in situ TEM observation for many kinds of nuclear materials. (authors)

  12. Low energy beam transport for HIDIF

    International Nuclear Information System (INIS)

    Meusel, O.; Pozimski, J.; Jakob, A.; Lakatos, A.

    2001-01-01

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe + beam are presented and the results of numerical simulations are shown

  13. Low energy beam transport for HIDIF

    Energy Technology Data Exchange (ETDEWEB)

    Meusel, O. E-mail: o.meusel@iap.uni-frankfurt.de; Pozimski, J.; Jakob, A.; Lakatos, A

    2001-05-21

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe{sup +} beam are presented and the results of numerical simulations are shown.

  14. Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection

    International Nuclear Information System (INIS)

    Chadwick, M.B.

    1998-01-01

    The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given

  15. Photonuclear processes in the treatment room and patient during radiation therapy with 50 MV photons

    Energy Technology Data Exchange (ETDEWEB)

    Gudowska, Irena [Karolinska Inst., Stockholm (Sweden). Dept. of Radiation Physics

    1997-10-01

    The objectives of this project were to determine the level of photoneutron radiation around the MM50 Racetrack Microtron at Karolinska Hospital, operating in different modes and to evaluate the photonuclear absorbed dose to the treated volume during therapy with a 50 MV photon beam. The photoneutron radiation has been studied both using a {sup 235}U fission chamber and by computer simulation. The estimated neutron equivalent dose due to accelerator produced neutrons delivered to the tissues inside and outside the treatment volume do not exceed the recommended values. However, there is a potential risk that the sensitive tissues (lens of the eye and gonads), outside the treatment volume, can receive a dose of about 300-500 mSv per photon treatment course of 60 Gy with a slight increase for secondary malignancies. 47 refs, 15 figs, 6 tabs.

  16. Photonuclear processes in the treatment room and patient during radiation therapy with 50 MV photons

    International Nuclear Information System (INIS)

    Gudowska, Irena

    1997-01-01

    The objectives of this project were to determine the level of photoneutron radiation around the MM50 Racetrack Microtron at Karolinska Hospital, operating in different modes and to evaluate the photonuclear absorbed dose to the treated volume during therapy with a 50 MV photon beam. The photoneutron radiation has been studied both using a 235 U fission chamber and by computer simulation. The estimated neutron equivalent dose due to accelerator produced neutrons delivered to the tissues inside and outside the treatment volume do not exceed the recommended values. However, there is a potential risk that the sensitive tissues (lens of the eye and gonads), outside the treatment volume, can receive a dose of about 300-500 mSv per photon treatment course of 60 Gy with a slight increase for secondary malignancies. 47 refs, 15 figs, 6 tabs

  17. Evaluation of photonuclear reaction cross-sections using the reduction method for large systematic uncertainties

    International Nuclear Information System (INIS)

    Varlamov, V.V.; Efimkin, N.G.; Ishkhanov, B.S.; Sapunenko, V.V.

    1994-12-01

    The authors describe a method based on the reduction method for the evaluation of photonuclear reaction cross-sections obtained under conditions where there are large systematic uncertainties (different instrumental functions, calibration and normalization errors). The evaluation method involves using the actual instrumental function (photon spectrum) of each individual experiment to reduce the data to a representation generated by an instrumental function of better quality. The objective is to find the most reasonably achievable monoenergetic representation of the information on the reaction cross-section derived from the results of various experiments and to take into account the calibration and normalization errors in these experiments. The method was used to obtain the evaluated total photoneutron reaction cross-section (γ,xn) for a large number of nuclei. Data obtained for 16 O and 208 Pb are presented. (author). 36 refs, 6 figs, 4 tabs

  18. Development of the low energy linac systems

    International Nuclear Information System (INIS)

    Cho, Yong Sub; Kwon, H. J.; Kim, Y. H.

    2005-08-01

    The project 'Development of the Low Energy Linac System' is aiming to develop the 20 MeV proton linac system. This consists of a 50 keV proton injector, a 3 MeV RFQ, and a 20 MeV DTL. We obtained the first beam signal after the 20 MeV linac. The high power switch installed in the ion source supplies the pulsed beam into the following LEBT. The pulse operation was successfully tested. The main role of the LEBT is to match the beam into the 3 MeV RFQ. The total length of the four-vane type RFQ is about 3.26m. For the field stabilization, we used the resonant coupling scheme and dipole stabilizer rods. An 1 MW klystron supplies the RF power into the RFQ. After tuning, the field deviation of the quadrupole mode is less than 2% of the design value and the dipole fraction is less than 5% of the operating mode. The following accelerating structure is DTL which accelerate 20 mA proton beams up to 20 MeV. It consists of 4 tanks and the length of each tank is less than 5 m. The lattice is FFDD type and the integrated fields of the quadrupole magnets are 1.75 T. The inner walls of the tanks are copper-plated by PR plating method. The thickness is 100m with the roughness of 0.3m. Each drift tube consists of 6 parts and assembled by e-beam welding. The tanks and drift tubes are aligned under the installation limit of 50m by using the laser-tracker. The tuning by the slug tuners and post couplers results in the field uniformity of 2% and field sensitivity of 100%/MHz. In order to detect the beam signal, we installed the Faraday cup after the RFQ or the DTL. For the RFQ, we observed the beam of 12 A under the forward RF power of 450 kW. The beam current after DTL is about 0.5 A when RF power of 150 kW was fed into each tank

  19. Low-Energy Ballistic Transfers to Lunar Halo Orbits

    Science.gov (United States)

    Parker, Jeffrey S.

    2009-01-01

    Recent lunar missions have begun to take advantage of the benefits of low-energy ballistic transfers between the Earth and the Moon rather than implementing conventional Hohmann-like lunar transfers. Both Artemis and GRAIL plan to implement low-energy lunar transfers in the next few years. This paper explores the characteristics and potential applications of many different families of low-energy ballistic lunar transfers. The transfers presented here begin from a wide variety of different orbits at the Earth and follow several different distinct pathways to the Moon. This paper characterizes these pathways to identify desirable low-energy lunar transfers for future lunar missions.

  20. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Prasad, R; Yadav, R S [Aligarh Muslim Univ. (India). Dept. of Physics; Naqvi, T H [Z.H. Engineering Coll., Aligarh (India); Ahmed, Rais [National Council of Educational Research and Training, New Delhi (India)

    1975-12-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described.

  1. UPC photo-nuclear dijet production in 5.02 TeV 
Pb+Pb collisions

    CERN Document Server

    Angerami, Aaron; The ATLAS collaboration

    2017-01-01

    Ultra-peripheral heavy ion collisions provide a unique opportunity to study the parton distributions in the colliding nuclei via the measurement of photo-nuclear dijet production. An analysis of dijet production in ultra-peripheral $\\sqrt{s}_{\\mathrm{NN}}$=5.02 TeV Pb+Pb collisions performed using data collected in 2015 is described. The data set corresponds to a total integrated luminosity of 0.38 $\\mathrm{nb}^{−1}$. The ultra-peripheral collisions are selected using a combination of trigger, zero degree calorimeter, and gap requirements. The jets are reconstructed using the anti-$k_t$ algorithm. The results of the measurement include cross-sections for photo-nuclear dijet production as a function of different dijet kinematic variables.

  2. Photonuclear reactions in the GNASH code: Benchmarking model calculations for reactions on lead up to 140 MeV

    International Nuclear Information System (INIS)

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

    1994-08-01

    The authors have developed the GNASH code to include photonuclear reactions for incident energies up to 140 MeV. Photoabsorption is modeled through the giant resonance at the lower energies, and the quasideuteron mechanism at the higher energies, and the angular momentum coupling of the incident photon to the target is properly accounted for. After the initial interaction, primary and multiple preequilibrium emission of fast particles can occur before compound nucleus decay from the equilibrated compound nucleus. The angular distributions from compound nucleus decay are taken as isotropic, and those from preequilibrium emission (which they obtain from a phase-space model which conserves momentum) are forward-peaked. To test the new modeling they apply the code to calculate photonuclear reactions on 208 Pb for incident energies up to 140 MeV

  3. A Low Energy Intelligent Clustering Protocol for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Li, Qiao; Cui, Lingguo; Zhang, Baihai

    2010-01-01

    LEACH (low-energy adaptive clustering hierarchy) is a well-known self-organizing, adaptive clustering protocol of wireless sensor networks. However it has some shortcomings when it faces such problems as the cluster construction and energy management. In this paper, LEICP (low energy intelligent...

  4. Passive and low energy cooling techniques for the Czech Republic

    NARCIS (Netherlands)

    Lain, M.; Hensen, J.L.M.; Santamouris, M.

    2005-01-01

    This paper deals with the applicability of passive and low energy cooling technologies in the Czech Republic. The work includes climate analysis as well as buildings and systems analysis in order to estimate the potential of passive and low energy cooling technologies. The latter is based on case

  5. Low-energy antiprotons physics and the FLAIR facility

    International Nuclear Information System (INIS)

    Widmann, E

    2015-01-01

    FLAIR, the Facility for low-energy antiproton and ion research has been proposed in 2004 as an extension of the planned FAIR facility at Darmstadt, Germany. FLAIR was not included into the modularized start version of FAIR, but the recent installation of the CRYRING storage ring at GSI Darmstadt has opened new perspectives for physics with low-energy antiprotons at FAIR. (paper)

  6. Positron impact ionization of atomic hydrogen at low energies

    Indian Academy of Sciences (India)

    The study of low energy ionization of atomic hydrogen has undergone a rapid ... Three distinct theories for describing low energy ionization can now .... clear evidence that the backward peak for ΘЅѕ = 180° is due to positron-nucleus scat-.

  7. Low-energy-consumption hybrid lasers for silicon photonics

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Ran, Qijiang; Mørk, Jesper

    2012-01-01

    Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed.......Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed....

  8. Low-energy heavy-ion reactions: Some recent developments

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1989-01-01

    We address three areas: behavior of the optical model at low energies and associated phenomena, fusion at near- and sub-barrier energies; where does fusion occur?, and recent examples of explicit coupled-channels effects at low energies. 74 refs., 18 figs

  9. Low energy dynamics of self-dual A1 strings

    International Nuclear Information System (INIS)

    Gustavsson, Andreas

    2003-01-01

    We examine the interrelation between the (2,0) supersymmetric six-dimensional effective action for the A 1 theory, and the corresponding low-energy theory for the collective coordinates associated to selfdual BPS strings. We argue that this low energy theory is a two-dimensional N=4 supersymmetric sigma model

  10. What is a low-energy house and who cares?

    Energy Technology Data Exchange (ETDEWEB)

    Litt, B.R.

    1994-12-01

    Most energy analysts view low-energy houses as good things, yet differ in their expectations of what exactly a low energy house is. There are two intertwining threads to this report. The first is an evaluation of 50 buildings that have been claimed to be low-energy residences, for which monitored energy performance data have been collected. These data represent the preliminary effort in the ongoing update of the Buildings Energy-Use Compilation and Analysis (BECA) data base for new residences. The second thread concerns the definition of a low-energy house. After the elements of a definition are presented, their implications for actors involved in providing housing are identified. Several more tractable definitions are applied to the houses in this compilation. The outcomes illustrate ways in which different interests are served by various definitions. Different definitions can yield very different energy rankings. No single definition of a low-energy house is universally applicable.

  11. Studies of photonuclear neutron emission during the start-up phase of the Alcator C tokamak

    International Nuclear Information System (INIS)

    Pappas, D.S.; Furnstahl, R.; Kochanski, G.P.

    1981-05-01

    Alcator C operations commenced with discharge cleaning and tokamak operation using hydrogen filling gas. Prior to and during these experiments no deuterium gas was allowed into the device. The earliest operation resulted in dosimeter readings of a few Roentgen per shot in the vicinity of the limiter and a localized source of neutron emission of up to 10 9 neutrons/shot. A strong correlation of the neutron emissions with hard x-ray emissions from the limiter and nonthermal features on the synchrotron emissions was observed during these discharges. Gamma energy spectroscopy of the activated limiter after removal from Alcator allowed identification of 16 radioisotopes which were consistent with photonuclear processes (γ,n , γ,p , γ,α reactions) arising in the limiter. After seven months of hydrogen operation conditions were achieved that resulted in substantially less non-thermal activity. Typical neutron emission rates of equal to or less than 10 6 n/sec were observed, i.e., about four orders of magnitude less than the expected D-D thermonuclear neutron emission rates for the same type of discharge if D 2 was used as the filling gas

  12. Mathematical modeling and multicriterion optimization for photonuclear production of the 67cu isotope

    International Nuclear Information System (INIS)

    Dikij, N.P.; Rudychev, Y.V.; Fedorchenko, D.V.; Khazhmuradov, M.A.

    2014-01-01

    This paper considers a method for 67 Cu isotope production using electron bremsstrahlung by the 68 Zn(gamma, p) 67 Cu reaction. The facility for 67 Cu isotope production contains an electron accelerator, electron-gamma converter and zinc target. To optimize this facility we developed three-dimensional model of the converter and the target. Using this model, we performed the mathematical modeling of zinc target irradiation and thermal-hydraulic processes inside the target for various parameters of the electron beam and converter configurations. For mathematical modeling of radiation processes we used the MCNPX software. Thermal-hydraulic simulation utilized the commercial SolidWorks software with Flow Simulation module. Mathematical modeling revealed that efficient 67 Cu isotope production needs smaller beam diameter and higher electron energy. Under these conditions target heat power also increases, thus additional cooling is necessary. If the beam diameter and the electron energy are fixed the most effective method to satisfy the operating parameters and retain an efficient isotope yield is to optimize photonuclear spectra of the target by variation of converter thickness. We developed an algorithm for multicriterion optimization and performed the optimization of the facility with account to coupled radiation and heat transfer processes.

  13. Applications of the photo-nuclear reaction data for activation analysis

    International Nuclear Information System (INIS)

    Odsuren, M.; Khuukhenkhuu, G.; Turbold, A.; Davaa, S.; Baatarkhuu, D.

    2015-01-01

    In the relative method of activation analysis by continuum wide spectrum gamma-rays the same isotope is usually used for standard reference element and sample material in connection with different dependence of the reaction cross sections on the irradiation beam energy. But, in practice suitable isotopes for reference element are not always available. So, in this paper, we suggest a new method for photo-activation analysis in which is used the correction factor. This factor takes into account the difference in the photo-nuclear reaction cross section dependence on the gamma-ray energy for standard reference isotope and sample elements. The correction factor is determined by three methods of experimental, theoretical and TALYS evaluation. Pure metal foils of Au, Cu and Mo were irradiated by bremsstrahlung gamma-rays on the electron cyclic accelerator Microtron MT-22 at the Nuclear Research Center, National University of Mongolia. Gamma spectra of the activated metal foils were measured by HP-Ge detector to obtain element contents in the samples. It was shown that experimental results with correction factors are satisfactorily in agreement with real values of the element contents in the samples

  14. States of low energy on Robertson-Walker spacetimes

    International Nuclear Information System (INIS)

    Olbermann, Heiner

    2007-01-01

    We construct a new class of physical states of the free Klein-Gordon field in Robertson-Walker spacetimes. This is done by minimizing the expectation value of smeared stress-energy. We get an explicit expression for the state depending on the smearing function. We call it a state of low energy. States of low energy are an improvement of the concept of adiabatic vacua on Robertson-Walker spacetimes. The latter are approximations of the former. It is shown that states of low energy are Hadamard states

  15. Low-energy effective action for the superstring

    International Nuclear Information System (INIS)

    Burgess, C.P.; Font, A.; Quevedo, F.

    1986-01-01

    We construct the low-energy D=4, N=1 supergravity that arises in superstring theories for an arbitrary number of generations. The coupling of all massless modes that carry low-energy gauge quantum numbers are calculated by truncating the heavy Kaluza-Klein modes of the ten-dimensional effective field theory. The resulting action is compared to the most general effective action compatible with the symmetries of the underlying ten-dimensional field (and string) theories. This comparison indicates which features of the truncation correctly approximate the exact low-energy action. (orig.)

  16. DCARR: a spectrograph for measuring low-energy x rays

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    DCARR, the Differential Critical Angle Reflection Refraction detector system, is described. This detector was designed to measure low-energy x rays, 500 to 5000 eV, with a high degree of resolution, 250 eV. DCARR was developed because these low-energy measurements are of interest in the diagnostics of x-radiation in nuclear tests and available equipment could not make measurements at this low an energy in field tests. DCARR is a versatile piece of equipment that can also be used as a laboratory tool, such as in measuring the low-energy x rays emitted by lasers and various x-ray machines

  17. Low-energy hadronic interactions beyond the current algebra approach

    International Nuclear Information System (INIS)

    Ivanov, A.N.; Troitskaya, N.I.; Nagy, M.

    1993-06-01

    The new low-energy AP 3 -interaction, which is produced by convergent box-constituent-quark-loop diagrams, is obtained within chiral perturbation theory at the quark level (CHPT) q with linear realization of chiral U(3) x U(3) symmetry. Its contributions to processes of low-energy interactions of low-lying mesons are investigated. The new interaction goes beyond the framework of the low-energy current algebra approach and of the effective chiral Lagrangians with linear realization of chiral symmetry, constructed at the hadronic level. (author). 17 refs, 3 figs

  18. A primer on Higgs boson low-energy theorems

    International Nuclear Information System (INIS)

    Dawson, S.; Haber, H.E.; California Univ., Santa Cruz, CA

    1989-05-01

    We give a pedagogical review of Higgs boson low-energy theorems and their applications in the study of light Higgs boson interactions with mesons and baryons. In particular, it is shown how to combine the chiral Lagrangian method with the Higgs low-energy theorems to obtain predictions for the interaction of Higgs bosons and pseudoscalar mesons. Finally, we discuss the relation between the low-energy theorems and a technique which makes use of the trace of the QCD energy-momentum tensor. 35 refs

  19. Low-energy buildings on mainstream market terms

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Elle, Morten; Hoffmann, Birgitte

    2008-01-01

    implementation of strict energy performance requirements in mainstream building. The paper describes how the municipality of Egedal experienced a collapse in regulation for low-energy buildings and what struggles it had to take on in order to convince the mainstream building industry and their customers......This paper looks into the challenge of actually implementing energy efficient technologies and concepts in mainstream new build. The aim of the paper is to point out some of the provisos of promoting low-energy buildings on mainstream market terms, emphasising the need to understand forces working...... against implementation of low-energy buildings. The study is based on actor-network theory, emphasising the relations and struggles that form the basis for pushing for low-energy buildings. The paper is based on a case study of the proactive attempt of a Danish municipality to force through an actual...

  20. Classification of low energy houses in Danish Building Regulations

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    The new Danish Building Regulations (Building Regulations, 2005) introduces the total energy consumption, i.e. energy use for heating, ventilation, cooling and domestic hot water, for buildings as a measure for the energy efficiency of new buildings, i.e. moving away from the former U-value demands....... In addition to the minimum requirements for new buildings, the new Building Regulations also specify requirements for characterizing a building as either low energy building class 1 or low energy building class 2. This paper describes a type-house that is presently being built in Denmark. The type......-house easily meets the requirements for being categorized as a low energy building class 1, and the paper investigates how much U-values can be increased if the type-house were to fulfil the requirements for a low energy building class 2 or a building that just fulfils the minimum demands....

  1. Biological assessments for the low energy demonstration accelerator, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1997-03-01

    This report discusses the biological impact to the area around the Los Alamos National Laboratory of the Low Energy Demonstration Accelerator. In particular the impact to the soils, water quality, vegetation, and wildlife are discussed.

  2. Low-energy nuclear reactions with double-solenoid- based ...

    Indian Academy of Sciences (India)

    solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

  3. Low energy effective Lagrangians in open superstring theory

    International Nuclear Information System (INIS)

    Medina, Ricardo

    2008-01-01

    The low energy effective Lagrangian describes the interactions of the massless modes of String Theory. Present work is being done to obtain all alpha' 3 terms (bosonic and fermionic) by means of the known 5-point amplitudes and SUSY

  4. Bag-model quantum chromodynamics for hyperons at low energy

    International Nuclear Information System (INIS)

    Weber, H.J.; Maslow, J.N.

    1980-01-01

    In a non-perturbative bag model framework, gluon exchange which mediates quark exchange scattering in conjunction with quark interchange is shown to be the basis of the OBE interactions of hyperons at low energy. (orig.)

  5. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The Ward identities of current algebra are combined with gauge invariance constraints, on-shell PCAC and the Bjorken limit to obtain the low-energy expressions of the pion photo- and electroproduction invariant amplitudes for physical pions

  6. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    International Nuclear Information System (INIS)

    Kumar, S.; Prasad, R.; Yadav, R.S.; Ahmed, Rais

    1975-01-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described. (author)

  7. Surface Passivation and Junction Formation Using Low Energy Hydrogen Implants

    Science.gov (United States)

    Fonash, S. J.

    1985-01-01

    New applications for high current, low energy hydrogen ion implants on single crystal and polycrystal silicon grain boundaries are discussed. The effects of low energy hydrogen ion beams on crystalline Si surfaces are considered. The effect of these beams on bulk defects in crystalline Si is addressed. Specific applications of H+ implants to crystalline Si processing are discussed. In all of the situations reported on, the hydrogen beams were produced using a high current Kaufman ion source.

  8. Low-energy limit of two-scale field theories

    International Nuclear Information System (INIS)

    Leon, J.; Perez-Mercader, J.; Sanchez, M.F.

    1991-01-01

    We present a full and self-contained discussion of the decoupling theorem applied to several general models in four-dimensional field theory. We compute in each case the low-energy effective action and show the explicit one-loop expressions for each of the effective parameters. We find that for suitable conditions one can always build an effective low-energy theory where the conditions of the decoupling theorem are satisfied

  9. Chromium and titanium isotopes produced in photonuclear reactions of vanadium, revisited

    Science.gov (United States)

    Sakamoto, K.; Yoshida, M.; Kubota, Y.; Fukasawa, T.; Kunugise, A.; Hamajima, Y.; Shibata, S.; Fujiwara, I.

    1989-10-01

    Photonuclear production yields of 51Ti und 51,49,48Cr from 51V were redetermined for bremsstrahlung end-point energies ( E0) of 30 to 1000 or 1050 MeV with the aid of radiochemical separation of Cr. The yield curves for 51Ti, 51Cr, 49Cr and 48Cr show a clear evidence for two components in the production process; one tor secondary-proton reactions at E0 Q, Qπ being Q-values for (γ, π +) and ( γ, π+xn) reactions. The contributions of the secondary reactions for production of the Ti and Cr isotopes at E0 > Qπ were then estimated by fitting calculated secondary yields to the observed ones at E0 code and the reported photoneutron and photoproton spectra from 12C and some other complex nuclei. The present results for 49Cr are close to the reported ones, while the present 48Cr yields differ by a factor of about 50. For the 51Ti and 51Cr yields, there are some discrepancies between the present and reported ones. The yield corrected for the secondaries, in units of μb/equivalent quantum, were unfolded into cross sections per photon, in units of μb, as a function ol monochromatic photon energy with the LOUHI-82 code. The results for the 51Ti and 49Cr are in disagreement in both the magnitude and shape with the theoretical predictions based on DWIA and PWIA. A Monte Carlo calculation based on the PICA code by Gabriel and Alsmiller does reproduce the gross feature of the present results.

  10. Studies and comparisons of two photon-tagging systems for the production of monochromatic photon beams for photonuclear experiments

    International Nuclear Information System (INIS)

    Aniel, Thierry.

    1982-06-01

    The performance of photon beams obtained by two different tagging processes (tagging of ''hard'' annihilation photons with ''soft'' associated photons, tagging of bremstrahlung photons with associated electrons) on the same facility was studied. The two processes are described and experimental results on the characteristics of the resulting beams given. The respective advantages of both methods are compared with one another and with those of a quasi-monochromatic beam obtained by the in-flight annihilation of a positron beam. A development based on the second process is then studied together with its applications to photonuclear physics [fr

  11. Updating Photonuclear Data Library and Generating a Reference Database for Photon Strength Functions. 1st Research Coordination Meeting. Summary Report

    International Nuclear Information System (INIS)

    Goriely, S.; Dimitriou, P.

    2016-07-01

    A summary is given of the 1 st Research Coordination Meeting of the new IAEA Co-ordinated Research Project (CRP) on Updating the Photonuclear Data Library and Generating a Reference Database for Photon Strength Functions. Participants presented their work, reviewed the current status of the field with regards to measurements, theoretical models and evaluations, discussed the scope of the work to be undertaken and agreed on a list of priorities and task assignments necessary to achieve the goals of the CRP. A summary of the presentations and discussions is presented in this report. (author)

  12. Internal defibrillation: pain perception of low energy shocks.

    Science.gov (United States)

    Steinhaus, David M; Cardinal, Debbie S; Mongeon, Luc; Musley, Shailesh Kumar; Foley, Laura; Corrigan, Susie

    2002-07-01

    Recently, device-based low energy cardoversion shocks have been used as therapy for AF. However, discomfort from internal low energy electrical shocks is poorly understood. The aim of this study was to evaluate pain perception with low energy internal discharges. Eighteen patients with ICD devices for malignant ventricular arrhythmias were recruited to receive shocks of 0.4 and 2 J in the nonsedated state. Discharges were delivered in a blinded, random order and questionnaires were used to determine discomfort levels and tolerability. Patients perceived discharges at these energies as relatively uncomfortable, averaging a score of 7.3 on a discomfort scale of 0-10, and could not distinguish 0.4-J shocks from 2-J shocks. Second shocks were perceived as more uncomfortable than initial discharges, regardless of the order in which the shocks were delivered. Despite the perceived discomfort, 83% of patients stated that they would tolerate discharges of this magnitude once per month, and 44% would tolerate weekly discharges. Patients perceive low energy discharges as painful and cannot distinguish between shocks of 0.4 and 2 J. The results suggest that ICD systems developed to treat atrial tachyarrhythmias should minimize the number of shocks delivered to terminate an atrial tachyarrhythmia episode. The majority of the patients tolerated low energy shocks provided the discharges are infrequent (once per month).

  13. Coulomb effects in low-energy nuclear fragmentation

    Science.gov (United States)

    Wilson, John W.; Chun, Sang Y.; Badavi, Francis F.; John, Sarah

    1993-01-01

    Early versions of the Langley nuclear fragmentation code NUCFRAG (and a publicly released version called HZEFRG1) assumed straight-line trajectories throughout the interaction. As a consequence, NUCFRAG and HZEFRG1 give unrealistic cross sections for large mass removal from the projectile and target at low energies. A correction for the distortion of the trajectory by the nuclear Coulomb fields is used to derive fragmentation cross sections. A simple energy-loss term is applied to estimate the energy downshifts that greatly alter the Coulomb trajectory at low energy. The results, which are far more realistic than prior versions of the code, should provide the data base for future transport calculations. The systematic behavior of charge-removal cross sections compares favorably with results from low-energy experiments.

  14. European national strategies to move towards very low energy buildings

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Thomsen, Kirsten Engelund

    high energy performance. It is important to stress the need for MS to introduce a national or regional definition of very low energy buildings in their building regulation and to develop a national strategy towards this level of energy performance to become the standard. This market transformation...... the ambition in the EU Action plan - to develop an EU strategy towards very low energy houses. The current recast of the EPBD is an opportunity, which must not be missed to introduce the requirement to MS to define very low energy buildings and a national strategy towards this level of energy performance....... A strategy for improved energy efficiency of existing buildings is a necessity if the energy consumption is to be reduced significantly over a limited period of time. The life time of buildings ranges from 50 to 100 years and improvement of the existing building stock will thus have much higher impact than...

  15. Coulomb and Nuclear Breakup at Low Energies: Scaling Laws

    Directory of Open Access Journals (Sweden)

    Hussein M. S.

    2013-12-01

    Full Text Available We report on a recent work on the low-energy behavior of the breakup cross section in so far as it has important role in the fusion of weakly bound and halo nuclei at near-barrier energies. We assess the way the nuclear component of this cross section scales with the target mass. In complete accord with previous finding at higher energies we verify that the low energy behavior of the breakup cross section for a given projectile and relative center of mass energy with respect to the Coulomb barrier height scales as the cubic root of the mass number of the target. Surprisingly we find that the Coulomb component of the breakup cross section at these low energies also obeys scaling, but with a linear dependence on the target charge. Our findings are important when planning for experiments involving these exotic nuclei.

  16. Low-energy limit of the extended Linear Sigma Model

    Energy Technology Data Exchange (ETDEWEB)

    Divotgey, Florian [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Kovacs, Peter [Wigner Research Center for Physics, Hungarian Academy of Sciences, Institute for Particle and Nuclear Physics, Budapest (Hungary); GSI Helmholtzzentrum fuer Schwerionenforschung, ExtreMe Matter Institute, Darmstadt (Germany); Giacosa, Francesco [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Jan-Kochanowski University, Institute of Physics, Kielce (Poland); Rischke, Dirk H. [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); University of Science and Technology of China, Interdisciplinary Center for Theoretical Study and Department of Modern Physics, Hefei, Anhui (China)

    2018-01-15

    The extended Linear Sigma Model is an effective hadronic model based on the linear realization of chiral symmetry SU(N{sub f}){sub L} x SU(N{sub f}){sub R}, with (pseudo)scalar and (axial-)vector mesons as degrees of freedom. In this paper, we study the low-energy limit of the extended Linear Sigma Model (eLSM) for N{sub f} = flavors by integrating out all fields except for the pions, the (pseudo-)Nambu-Goldstone bosons of chiral symmetry breaking. The resulting low-energy effective action is identical to Chiral Perturbation Theory (ChPT) after choosing a representative for the coset space generated by chiral symmetry breaking and expanding it in powers of (derivatives of) the pion fields. The tree-level values of the coupling constants of the effective low-energy action agree remarkably well with those of ChPT. (orig.)

  17. Low-energy physics of high-temperature superconductors

    International Nuclear Information System (INIS)

    Emery, V.J.; Kivelson, S.A.

    1992-01-01

    It is argued that the low-energy properties of high temperature superconductors are dominated by the interaction between the mobile holes and a particular class of collective modes, corresponding to local large-amplitude low-energy fluctuations in the hole density. The latter are a consequence of the competition between the effects of long-range Coulomb interactions and the tendency of a low concentration of holes in an antiferromagnet to phase separate. The low-energy behavior of the system is governed by the same fixed point as the two-channel Kondo problem, which accounts for the ''universality'' of the properties of the cuprate superconductors. Predictions of the optical properties and the spin dynamics are compared with experiment. The pairing resonance of the two Kondo problem gives a mechanism of high temperature superconductivity with an unconventional symmetry of the order parameter

  18. Electric and Magnetic Dipole Strength at Low Energy

    Science.gov (United States)

    Sieja, K.

    2017-08-01

    A low-energy enhancement of radiative strength functions was deduced from recent experiments in several mass regions of nuclei, which is believed to impact considerably the calculated neutron capture rates. In this Letter we investigate the behavior of the low-energy γ -ray strength of the Sc 44 isotope, for the first time taking into account both electric and magnetic dipole contributions obtained coherently in the same theoretical approach. The calculations are performed using the large-scale shell-model framework in a full 1 ℏω s d -p f -g d s model space. Our results corroborate previous theoretical findings for the low-energy enhancement of the M 1 strength but show quite different behavior for the E 1 strength.

  19. Electron polarimetry at low energies in Hall C at JLab

    International Nuclear Information System (INIS)

    Gaskell, D.

    2013-01-01

    Although the majority of Jefferson Lab experiments require multi-GeV electron beams, there have been a few opportunities to make electron beam polarization measurements at rather low energies. This proceedings will discuss some of the practical difficulties encountered in performing electron polarimetry via Mo/ller scattering at energies on the order of a few hundred MeV. Prospects for Compton polarimetry at very low energies will also be discussed. While Mo/ller scattering is likely the preferred method for electron polarimetry at energies below 500 MeV, there are certain aspects of the polarimeter and experiment design that must be carefully considered

  20. A facility for low energy charged particle induced reaction studies

    International Nuclear Information System (INIS)

    Vilaithong, T.; Singkarat, S.; Yu, L.D.; Intarasiri, S.; Tippawan, U.

    2000-01-01

    In Chiang Mai, a highly stable low energy ion accelerator (0 - 350 kV) facility is being established. A subnano-second pulsing system will be incorporated into the beam transport line. The detecting system will consist of a time-of-flight charged particle spectrometer and a high resolution gamma-ray system. The new facility will be used in the studies of low energy heavy ion backscattering and charged particle induced cross section measurement in the interests of material characterization and nucleosynthesis. (author)

  1. Scattering of polarized low-energy electrons by ferromagnetic metals

    International Nuclear Information System (INIS)

    Helman, J.S.

    1981-01-01

    A source of spin polarized electrons with remarkable characteristics based on negative electron affinity (NEA) GaAs has recently been developed. It constitutes a unique tool to investigate spin dependent interactions in electron scattering processes. The characteristics and working principles of the source are briefly described. Some theoretical aspects of the scattering of polarized low-energy electrons by ferromagnetic metals are discussed. Finally, the results of the first polarized low-energy electron diffraction experiment using the NEA GaAs source are reviewed; they give information about the surface magnetization of ferromagnetic Ni (110). (Author) [pt

  2. Very low energy scanning electron microscopy in nanotechnology

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Hovorka, Miloš; Mika, Filip; Mikmeková, Eliška; Mikmeková, Šárka; Pokorná, Zuzana; Frank, Luděk

    2012-01-01

    Roč. 9, 8/9 (2012), s. 695-716 ISSN 1475-7435 R&D Projects: GA MŠk OE08012; GA MŠk ED0017/01/01; GA AV ČR IAA100650902 Institutional research plan: CEZ:AV0Z20650511 Keywords : scanning electron microscopy * very low energy electrons * cathode lens * grain contrast * strain contrast * imaging of participates * dopant contrast * very low energy STEM * graphene Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.087, year: 2012

  3. Obervations of low energy magnetospheric plasma outside the plasmasphere

    International Nuclear Information System (INIS)

    Hultqvist, B.

    1985-01-01

    After some introductory discussions about morphological concepts and limitations of various measurement techniques, existing low energy plasma data, orginating primarily from the GEOS, Dynamics Explorer, and Prognoz spacecraft, is described and discussed. The plasmasphere measurements are not included (but for some observations of plasmasphere refilling). It is finally concluded that we are very far from a complete picture of the low-energy plasma component in the magnetosphere and that this problem has to be given high priority in planning payloads of future space plasma physics missions. (Author)

  4. Progress on a spherical TPC for low energy neutrino detection

    International Nuclear Information System (INIS)

    Aune, S; Colas, P; Deschamps, H; Dolbeau, J; Fanourakis, G; Ribas, E Ferrer; Enqvist, T; Geralis, T; Giomataris, Y; Gorodetzky, P; Gounaris, G J; Gros, M; Irastorza, I G; Kousouris, K; Lepeltier, V; Morales, J; Patzak, T; Paschos, E A; Salin, P; Savvidis, I; Vergados, J D

    2006-01-01

    The new concept of the spherical TPC aims at relatively large target masses with low threshold and background, keeping an extremely simple and robust operation. Such a device would open the way to detect the neutrino-nucleus interaction, which, although a standard process, remains undetected due to the low energy of the neutrino-induced nuclear recoils. The progress in the development of the first 1 m 3 prototype at Saclay is presented. Other physics goals of such a device could include supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino, among others

  5. Universality in low energy three-body systems

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Tomio, L; Frederico, T.

    1997-01-01

    The renormalizability of the quantum theory of non-relativistic three-body system with zero range interaction, warranties that all the low-energy three-body properties are well defined and the low-energy two-body and only one three-body physical information are known. Considering this observation, we have shown that the conditions for the occurrence of Efimov states can be easily reached with any model of short range potential where the three-body ground state and the corresponding binding energy of the subsystems are kept fixed. This approach was applied to the recently discovered halo nuclei. (author)

  6. Ultra-low-energy wide electron exposure unit

    International Nuclear Information System (INIS)

    Yonago, Akinobu; Oono, Yukihiko; Tokunaga, Kazutoshi; Kishimoto, Junichi; Wakamoto, Ikuo

    2001-01-01

    Heat and ultraviolet ray processes are used in surface dryness of paint, surface treatment of construction materials and surface sterilization of food containers. A process using a low-energy wide-area electron beam (EB) has been developed that features high speed and low drive cost. EB processing is not widespread in general industry, however, due to high equipment cost and difficult maintenance. We developed an ultra-low-energy wide-area electron beam exposure unit, the Mitsubishi Wide Electron Exposure Unit (MIWEL) to solve these problems. (author)

  7. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  8. Occupant Experiences and Satisfaction with New Low-Energy Houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Thomsen, Kirsten Engelund; Mørck, Ove

    2013-01-01

    -energy houses that meet the future lower energy requirements of the planned Danish Building Regulations 2015. The purpose was to study experiences and satisfaction among occupants living in new low-energy houses. It included i.a. overall satisfaction, perceived indoor climate and experiences and satisfaction...... be addressed in order to make low-energy houses attractive to ordinary people. Occupants experienced among other things noise from the technical installations and that it was too hot in summer and too cold in winter, that there were a series of problems with the technical installations and that their use...

  9. Implementation of the n-body Monte-Carlo event generator into the Geant4 toolkit for photonuclear studies

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wen, E-mail: wenluo-ok@163.com [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Lan, Hao-yang [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Xu, Yi; Balabanski, Dimiter L. [Extreme Light Infrastructure-Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului, 077125 Bucharest-Magurele (Romania)

    2017-03-21

    A data-based Monte Carlo simulation algorithm, Geant4-GENBOD, was developed by coupling the n-body Monte-Carlo event generator to the Geant4 toolkit, aiming at accurate simulations of specific photonuclear reactions for diverse photonuclear physics studies. Good comparisons of Geant4-GENBOD calculations with reported measurements of photo-neutron production cross-sections and yields, and with reported energy spectra of the {sup 6}Li(n,α)t reaction were performed. Good agreements between the calculations and experimental data were found and the validation of the developed program was verified consequently. Furthermore, simulations for the {sup 92}Mo(γ,p) reaction of astrophysics relevance and photo-neutron production of {sup 99}Mo/{sup 99m}Tc and {sup 225}Ra/{sup 225}Ac radioisotopes were investigated, which demonstrate the applicability of this program. We conclude that the Geant4-GENBOD is a reliable tool for study of the emerging experiment programs at high-intensity γ-beam laboratories, such as the Extreme Light Infrastructure – Nuclear Physics facility and the High Intensity Gamma-Ray Source at Duke University.

  10. Isomeric ratios in photonuclear reactions of molybdenum isotopes induced by bremsstrahlung in the giant dipole resonance region

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Truong Thi An; Phan Viet Cuong; Nguyen The Vinh; Bui Minh Hue; Belov, A.G.; Maslov, O.D.; Mishinsky, G.V.; Zhemenik, V.I.

    2017-01-01

    We have determined the isomeric ratios of isomeric pairs "9"7"m","gNb, "9"5"m","gNb and "9"1"m","gMo produced in "9"8Mo(γ, p)"9"7"m","gNb, "9"6Mo(γ, p)"9"5"m","gNb and "9"2Mo(γ, n)"9"1"m","gMo photonuclear reactions in the giant dipole resonance (GDR) region by the activation method. The results were analyzed, discussed and compared with the similar data from literature to examine the role of excitation energy, neutron configuration, channel effect, and direct and pre-equilibrium processes in (γ, p) photonuclear reactions. In this work the isomeric ratios for "9"7"m","gNb from 14 to 19 MeV, for "1"9"5"m","gNb from 14 to 24 MeV except 20 and 23.5 MeV and for "9"1"m","gMo at 14 and 15 MeV were first measured.

  11. Development of dose delivery verification by PET imaging of photonuclear reactions following high energy photon therapy

    International Nuclear Information System (INIS)

    Janek, S; Svensson, R; Jonsson, C; Brahme, A

    2006-01-01

    A method for dose delivery monitoring after high energy photon therapy has been investigated based on positron emission tomography (PET). The technique is based on the activation of body tissues by high energy bremsstrahlung beams, preferably with energies well above 20 MeV, resulting primarily in 11 C and 15 O but also 13 N, all positron-emitting radionuclides produced by photoneutron reactions in the nuclei of 12 C, 16 O and 14 N. A PMMA phantom and animal tissue, a frozen hind leg of a pig, were irradiated to 10 Gy and the induced positron activity distributions were measured off-line in a PET camera a couple of minutes after irradiation. The accelerator used was a Racetrack Microtron at the Karolinska University Hospital using 50 MV scanned photon beams. From photonuclear cross-section data integrated over the 50 MV photon fluence spectrum the predicted PET signal was calculated and compared with experimental measurements. Since measured PET images change with time post irradiation, as a result of the different decay times of the radionuclides, the signals from activated 12 C, 16 O and 14 N within the irradiated volume could be separated from each other. Most information is obtained from the carbon and oxygen radionuclides which are the most abundant elements in soft tissue. The predicted and measured overall positron activities are almost equal (-3%) while the predicted activity originating from nitrogen is overestimated by almost a factor of two, possibly due to experimental noise. Based on the results obtained in this first feasibility study the great value of a combined radiotherapy-PET-CT unit is indicated in order to fully exploit the high activity signal from oxygen immediately after treatment and to avoid patient repositioning. With an RT-PET-CT unit a high signal could be collected even at a dose level of 2 Gy and the acquisition time for the PET could be reduced considerably. Real patient dose delivery verification by means of PET imaging seems to be

  12. SU-E-T-612: Photonuclear Activation of Prosthetic Hips in Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Keehan, S; Taylor, M; Franich, R [RMIT University, Melbourne, VIC (Australia); Smith, R; Millar, J; Esser, M [William Buckland Radiotherapy Centre, Melbourne, VIC (Australia); Kron, T [Peter MacCallum Cancer Instit., Melbourne (Australia)

    2015-06-15

    Purpose: To measure the neutron induced activation of a prosthetic hip when exposed to an 18 MV radiotherapy linac beam to assess the potential dose to patients. Methods: A prosthetic hip (Thackray, UK) was placed in a water phantom and irradiated (both in-field and out-of-field) with an 18 MV linac beam. Gamma spectroscopy was used to identify the radioisotopes produced. Following the in-field irradiation where the induced activity is higher, high sensitivity lithium fluoride Thermoluminescence Dosimeters (TLD-100H) (Harshaw, USA) were placed on the surface to measure the dose which would be deposited to nearby tissue resulting from the induced radioactivity. Results: The radioisotopes produced in the hip prosthesis have been identified as {sup 5{sup 2}}V, {sup 5{sup 3}}Fe, and {sup 56}Mn which have half-lives of 3.74, 8.51 and minutes respectively. The 378 and 511 keV characteristic peaks of {sup 5{sup 3}}Fe do not appear in the spectra collected from hips irradiated in the out-of-field region. This isotope is produced by photonuclear interactions within the hip itself. {sup 52}V and {sup 56}Mn appear in spectra collected from hips irradiated either within the photon beam or in the nearby out-of-field region, implying that they are produced by incident neutron radiation produced in components of the linear accelerator.The integrated dose which would be deposited in the tissue immediately surrounding the hip after four hours (1.5 half-lives of the longest lived product) was measured as approximately 100 µGy, following a 10,000 MU irradiation of the prosthesis. A highly accurate measurement of the dose is challenging because of the irregular shape of the prosthesis. Conclusion: The cumulative dose measured at the surface of the hip is 0.0001% of the in-field dose, and is therefore negligible compared with the doses the patient receives as a consequence of their treatment.

  13. Chromium and titanium isotopes produced in photonuclear reactions of vanadium, revisited

    International Nuclear Information System (INIS)

    Sakamoto, K.; Yoshida, M.; Kubota, Y.; Fukasawa, T.; Kunugise, A.; Hamajima, Y.; Shibata, S.; Fujiwara, I.

    1988-10-01

    Photonuclear production yields of 51 Ti and 51,49,48 Cr from 51 V were redetermined for bremsstrahlung end-point energies (E 0 ) of 30 to 1000 or 1050 MeV with an aid of radiochemical separation of Cr. The yield curves for 51 Ti, 51 Cr, 49 Cr and 48 Cr show a clear evidence for two components ; one for secondary-proton reaction at E 0 π ± and the other for photopion reaction, at E 0 > Q π ±, Q π ± being Q values for (γ,π + ) and (γ,π - xn)-reactions. The contributions of the secondary reactions for production of the Ti and Cr isotopes at E 0 > Q π ± were then estimated by fitting a calculated secondary yields to the observed ones at E 0 π ±, and found to be about 40, 20, 4 and 4 % for 51 Ti, 51 Cr, 49 Cr and 48 Cr, respectively, at E 0 = 400 to 1000 MeV. The calculation of the secondary yields was based on the excitation functions for 51 V(n,p) and (p,x'n) calculated with ALICE code and the reported photoneutron and photoproton spectra from 12 C and some other complex nuclei. The present results for 49 Cr are very close to the reported ones, while the present 48 Cr yields differ by a factor of about 50. For the 51 Ti and 51 Cr yields, there are some discrepancies between the present and reported ones. The yields corrected for the secondaries, in unit of μb/equivalent quantum, were unfolded into cross sections per photon, in unit of μb, as a function of monochromatic photon energy with the LOUHI-82 code. The results for the 51 Ti and 49 Cr are in disagreement in both the magnitude and shape with the theoretical predictions based on DWIA and PWIA. A Monte Carlo calculation does not reproduce the present result for the 49 Cr yield. (author)

  14. Web server of the Centre for Photonuclear Experiments Data of the Scientific Research Institute for Nuclear Physics, Moscow State University: Hypertext version of the nuclear physics database

    Energy Technology Data Exchange (ETDEWEB)

    Boboshin, I N; Varlamov, A V; Varlamov, V V; Rudenko, D S; Stepanov, M E [D.V. Skobel' tsyn Scientific Research Institute for Nuclear Physics, M.V. Lomonosov Moscow State University, Centre for Photonuclear Experiments Data (Russian Federation)

    2001-02-01

    The nuclear databases which have been developed at the Centre for Photonuclear Experiments Data of the D.V. Skobel'tsyn Scientific Research Institute for Nuclear Physics, M.V. Lomonosov Moscow State University, and put on the Centre's web server, are presented. The possibilities for working with these databases on the Internet are described. (author)

  15. Web server of the Centre for Photonuclear Experiments Data of the Scientific Research Institute for Nuclear Physics, Moscow State University: Hypertext version of the nuclear physics database

    International Nuclear Information System (INIS)

    Boboshin, I.N.; Varlamov, A.V.; Varlamov, V.V.; Rudenko, D.S.; Stepanov, M.E.

    2001-01-01

    The nuclear databases which have been developed at the Centre for Photonuclear Experiments Data of the D.V. Skobel'tsyn Scientific Research Institute for Nuclear Physics, M.V. Lomonosov Moscow State University, and put on the Centre's web server, are presented. The possibilities for working with these databases on the Internet are described. (author)

  16. Charge-coupled device area detector for low energy electrons

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    2003-01-01

    Roč. 74, č. 7 (2003), s. 3379 - 3384 ISSN 0034-6748 R&D Projects: GA ČR GA102/00/P001 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy electrons * charged-coupled device * detector Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.343, year: 2003

  17. Utilization of low-energy electron accelerators in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2003-02-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  18. Corrosion behavior of low energy, high temperature nitrogen ion ...

    Indian Academy of Sciences (India)

    Corrosion behavior of low energy, high temperature nitrogen ion-implanted AISI 304 stainless steel. M GHORANNEVISS1, A SHOKOUHY1,∗, M M LARIJANI1,2,. S H HAJI HOSSEINI 1, M YARI1, A ANVARI4, M GHOLIPUR SHAHRAKI1,3,. A H SARI1 and M R HANTEHZADEH1. 1Plasma Physics Research Center, Science ...

  19. Acceleration of low energy charged particles by gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Voyatzis, G. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)]. E-mail: voyatzis@auth.gr; Vlahos, L. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Ichtiaroglou, S. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Papadopoulos, D. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)

    2006-04-03

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

  20. Acceleration of low energy charged particles by gravitational waves

    International Nuclear Information System (INIS)

    Voyatzis, G.; Vlahos, L.; Ichtiaroglou, S.; Papadopoulos, D.

    2006-01-01

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state

  1. Low energy supersymmetric models for several generations and proton decay

    International Nuclear Information System (INIS)

    Deo, B.B.; Sarkar, U.

    1983-08-01

    It is found that by invoking additional horizontal gauge symmetries required to explain the generational structure the low energy standard supersymmetric unified theories avoid the renormalizable unsuppressed baryon number violating interactions in a natural way. Theories considered here are anomaly-free by construction. (author)

  2. Low energy house in existing buildings; Niedrigenergiehaus im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Sahner, G. [BDA, Stuttgart/Augsburg (Germany)

    2008-07-01

    Presented is an energetic sanitation of residential units in the frame of a German pilot program (''low energy houses in the existing building sector'') initiated by the ministry of traffic, civil engineering and city development. (GL)

  3. Chiral symmetry and nucleon structure: Low energy aspects

    International Nuclear Information System (INIS)

    Weise, W.

    1989-01-01

    The symmetries and currents of QCD at low energy and long wavelength are realized in the form of mesons, rather than quarks and gluons. In this talk I summarize the merits, but also the limits, of chiral non-linear meson theories and their soliton solutions, in descriptions of nucleon structure and the nucleon-nucleon interaction. (orig.)

  4. Low-energy cosmic rays in the Orion region

    DEFF Research Database (Denmark)

    Pohl, M.

    1998-01-01

    The recently observed nuclear gamma-ray line emission from the Orion complex implies a high flux of low-energy cosmic rays (LECR) with unusual abundance. This cosmic ray component would dominate the energy density, pressure, and ionising power of cosmic rays, and thus would have a strong impact...

  5. Overview of the low energy accelerator scanning system

    International Nuclear Information System (INIS)

    Leo Kwee Wah; Lojius Lombigit; Muhamad Zahidee Taat; Abu Bakar Ghazali; Mohd Rizal Ibrahim; Mohd Rizal Chulan Md Chulan; Azaman Ahmad; Abdul Halim Baijan; Rokiah Mohd Sabri

    2009-01-01

    This paper describes the specification of the low energy accelerator (Baby-EBM; Electron Beam Machine) scanning system. It comprises a discussion of coil inductance measurement, power supply design and the test results. The scanning horn system was completely assembled and tested; it was found that the system is able to scan the beam across the scanning window with a required beam profile. (Author)

  6. Low-energy nuclear reactions with double-solenoid

    Indian Academy of Sciences (India)

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems ...

  7. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  8. MEIC Proton Beam Formation with a Low Energy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  9. Low-energy properties of fractional helical Luttinger liquids

    NARCIS (Netherlands)

    Meng, T.; Fritz, L.|info:eu-repo/dai/nl/371569559; Schuricht, D.|info:eu-repo/dai/nl/369284690; Loss, D.

    2014-01-01

    We investigate the low-energy properties of (quasi) helical and fractional helical Luttinger liquids. In particular, we calculate the Drude peak of the optical conductivity, the density of states, as well as charge transport properties of the interacting system with and without attached Fermi liquid

  10. Utilization of low-energy electron accelerators in Korea

    International Nuclear Information System (INIS)

    Lee, Byung Cheol

    2003-01-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  11. Elastic scattering of low energy γ-rays

    International Nuclear Information System (INIS)

    Whittingham, I.B.

    1978-01-01

    The current status of the theory of the elastic scattering of low energy γ rays is reviewed and a detailed analysis of the theoretical background to the recent calculation of Rayleigh scattering by W.R.Johnson and co-workers is presented

  12. Characterization of low energy radioactive beams using direct reactions

    DEFF Research Database (Denmark)

    Johansen, J.G.; Fraser, M.A.; Bildstein, V.

    2013-01-01

    We demonstrate a new technique to determine the beam structure of low energy radioactive beams using coincidence events from a direct reaction. The technique will be described and tested using Geant4 simulations. We use the technique to determine for the first time the width, divergence and energy...

  13. Low-energy positron beams - origins, developments and applications

    International Nuclear Information System (INIS)

    Beling, C.D.; Charlton, M.

    1987-01-01

    Over the last 15 years there have been rapid advances in the technology associated with low-energy positron beams. The origins of these advances, and some of the major developments, are discussed. Some applications from the diverse fields of surface physics, atomic scattering and positronium studies are highlighted. (author)

  14. Performance of the Low-energy House in Sisimiut

    DEFF Research Database (Denmark)

    Rode, Carsten; Kragh, Jesper; Borchersen, Egil

    2009-01-01

    A low-energy house was built in Sisimiut, Greenland in 2004-05 and since its inauguration in April 2005, its performance and operation have been object of study for researchers and students. The house is characterised by a highly insulated building envelope, advanced windows and a ventilation sys...

  15. QCD at low energy: a many-body approach

    International Nuclear Information System (INIS)

    Yépez-Martínez, T; Hess, P O; Lerma, S; Szczepaniak, A; Civitarese, O

    2011-01-01

    A review is given on recent results in the treatment of an arbitrary number of orbital levels in low energy QCD. For the pure quark part, analytic results for the dominant part of the Hamiltonian are presented. Possible extensions, including dynamic gluons, are discussed.

  16. Layout of the LER [Low Energy Ring] Arc

    International Nuclear Information System (INIS)

    Hutton, A.

    1990-01-01

    We have recently been trying to accumulate all of the information necessary to decide on the layout of the regular curved arcs of the Low Energy Ring (LER) and there have been several ABC Notes published on different aspects of the problem. This note will describe the layout that has been derived from these considerations

  17. Low energy quasi free scattering on nuclear surface

    Energy Technology Data Exchange (ETDEWEB)

    Shiyuan, S.

    1983-05-01

    The result of RGM calculation of low energy /sup 3/He(n, n)/sup 3/ He total elastic cross section does not agree well with experimental data for E/sub n/<1 MeV. This discrepancy can be improved by assuming lwo energy quasi-free scattering of particles beyond the nuclear surface.

  18. Working group report: Low energy and flavour physics

    Indian Academy of Sciences (India)

    This is a report of the low energy and flavour physics working group at ... that calculates the non-leptonic decay amplitudes including the long-distance con- tributions. There were three lectures that lasted for over seven hours, and were.

  19. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

  20. Low energy p anti p strong interactions: theoretical perspective

    International Nuclear Information System (INIS)

    Dover, C.B.

    1985-01-01

    Several of the frontier problems in low energy nucleon-antinucleon phenomenology are addressed. Spin observables and dynamical selection rules in N anti N annihilation are used as examples of phenomena which offer particularly strong constraints on theoretical models, formulated either in terms of meson and baryon exchange or as effective operators in a non-perturbative quark-gluon picture. 24 refs

  1. Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV.

    Science.gov (United States)

    Gudowska, I; Brahme, A; Andreo, P; Gudowski, W; Kierkegaard, J

    1999-09-01

    The absorbed dose due to photonuclear reactions in soft tissue, lung, breast, adipose tissue and cortical bone has been evaluated for a scanned bremsstrahlung beam of end point 50 MeV from a racetrack accelerator. The Monte Carlo code MCNP4B was used to determine the photon source spectrum from the bremsstrahlung target and to simulate the transport of photons through the treatment head and the patient. Photonuclear particle production in tissue was calculated numerically using the energy distributions of photons derived from the Monte Carlo simulations. The transport of photoneutrons in the patient and the photoneutron absorbed dose to tissue were determined using MCNP4B; the absorbed dose due to charged photonuclear particles was calculated numerically assuming total energy absorption in tissue voxels of 1 cm3. The photonuclear absorbed dose to soft tissue, lung, breast and adipose tissue is about (0.11-0.12)+/-0.05% of the maximum photon dose at a depth of 5.5 cm. The absorbed dose to cortical bone is about 45% larger than that to soft tissue. If the contributions from all photoparticles (n, p, 3He and 4He particles and recoils of the residual nuclei) produced in the soft tissue and the accelerator, and from positron radiation and gammas due to induced radioactivity and excited states of the nuclei, are taken into account the total photonuclear absorbed dose delivered to soft tissue is about 0.15+/-0.08% of the maximum photon dose. It has been estimated that the RBE of the photon beam of 50 MV acceleration potential is approximately 2% higher than that of conventional 60Co radiation.

  2. Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV

    International Nuclear Information System (INIS)

    Gudowska, I.; Brahme, A.; Andreo, P.; Gudowski, W.; Kierkegaard, J.

    1999-01-01

    The absorbed dose due to photonuclear reactions in soft tissue, lung, breast, adipose tissue and cortical bone has been evaluated for a scanned bremsstrahlung beam of end point 50 MeV from a racetrack accelerator. The Monte Carlo code MCNP4B was used to determine the photon source spectrum from the bremsstrahlung target and to simulate the transport of photons through the treatment head and the patient. Photonuclear particle production in tissue was calculated numerically using the energy distributions of photons derived from the Monte Carlo simulations. The transport of photoneutrons in the patient and the photoneutron absorbed dose to tissue were determined using MCNP4B; the absorbed dose due to charged photonuclear particles was calculated numerically assuming total energy absorption in tissue voxels of 1 cm 3 . The photonuclear absorbed dose to soft tissue, lung, breast and adipose tissue is about (0.11-0.12)±0.05% of the maximum photon dose at a depth of 5.5 cm. The absorbed dose to cortical bone is about 45% larger than that to soft tissue. If the contributions from all photoparticles (n, p, 3 He and 4 He particles and recoils of the residual nuclei) produced in the soft tissue and the accelerator, and from positron radiation and gammas due to induced radioactivity and excited states of the nuclei, are taken into account the total photonuclear absorbed dose delivered to soft tissue is about 0.15±0.08% of the maximum photon dose. It has been estimated that the RBE of the photon beam of 50 MV acceleration potential is approximately 2% higher than that of conventional 60 Co radiation. (author)

  3. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    International Nuclear Information System (INIS)

    King, F; Kruppi, T; Müller, J; Dörner, R; Schmidt, L Ph H; Schmidt-Böcking, H; Stiebing, K E

    2015-01-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections. (paper)

  4. Radiation processing of liquid with low energy electron accelerator

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2003-01-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

  5. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  6. Utilization of bio-resources by low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2003-01-01

    Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  7. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  8. Low-energy restoration of parity and maximal symmetry

    International Nuclear Information System (INIS)

    Raychaudhuri, A.; Sarkar, U.

    1982-01-01

    The maximal symmetry of fermions of one generation, SU(16), which includes the left-right-symmetric Pati-Salam group, SU(4)/sub c/ x SU(2) /sub L/ x SU(2)/sub R/, as a subgroup, allows the possibility of a low-energy (M/sub R/approx.100 GeV) breaking of the left-right symmetry. It is known that such a low-energy restoration of parity can be consistent with weak-interaction phenomenology. We examine different chains of descent of SU(16) that admit a low value of M/sub R/ and determine the other intermediate symmetry-breaking mass scales associated with each of these chains. These additional mass scales provide an alternative to the ''great desert'' expected in some grand unifying models. The contributions of the Higgs fields in the renormalization-group equations are retained and are found to be important

  9. Experimental nuclear physics research challenges at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E.; Morales G, L. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Murillo O, G. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2010-02-15

    Experimental research with low energy beams of ions (a few MeV) in nuclear physics has gone through a phase transition along its evolution in fifty years because of the increasing complexity (and cost) of the equipment required to conduct meaningful investigations. Many of the small cyclotrons and Van de Graaff (single ended and tandem) accelerators have been used for the last three decades mostly in applications related to the characterization and modification of materials. Specific experimental investigations in nuclear physics with low energy accelerators are proposed in this work. Specifically we discuss the topic of nuclear radii measurements of radioactive species produced via (d,n) reactions. Some emphasis is given to the instrumentation required. (Author)

  10. Si etching with reactive neutral beams of very low energy

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Yasuhiro [Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-chou, Suita, Osaka 565-0871 (Japan); Hamagaki, Manabu; Mise, Takaya [RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan); Iwata, Naotaka; Hara, Tamio [Toyota Technological Institute, 2-12-1 Hisakata, Tenpaku-ku, Nagoya 468-8511 (Japan)

    2014-12-14

    A Si etching process has been investigated with reactive neutral beams (NBs) extracted using a low acceleration voltage of less than 100 V from CF{sub 4} and Ar mixed plasmas. The etched Si profile shows that the etching process is predominantly anisotropic. The reactive NB has a constant Si etching rate in the acceleration voltage range from 20 V to 80 V. It is considered that low-energy NBs can trigger Si etching because F radicals adsorb onto the Si surface and weaken Si–Si bonds. The etching rate per unit beam flux is 33 times higher than that with Ar NB. These results show that the low-energy reactive NB is useful for damage-free high speed Si etching.

  11. Diagnosis and dynamics of low energy electron beams using DIADYN

    International Nuclear Information System (INIS)

    Marghitu, S.; Oproiu, C.; Toader, D.; Ruset, C.; Grigore, E.; Marghitu, O.; Vasiliu, M.

    2008-01-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  12. Diagnosis and dynamics of low energy electron beams using DIADYN

    Energy Technology Data Exchange (ETDEWEB)

    Marghitu, S [Electrostatica, ICPE-CA S.A., Spaiul Unirii 313, Sector 3, RO-74204 Bucharest (Romania); Oproiu, C; Toader, D; Ruset, C; Grigore, E [National Institute for Laser, Plasma and Radiation Physics, PO Box MG-36, 409 Atomistilor Street, RO-76900 Bucharest-Magurele (Romania); Marghitu, O [Institute for Space Sciences, INCDLPFR, PO Box MG-23, RO-76911 Bucharest-Magurele (Romania); Vasiliu, M [Politehnica University, 313 Splaiul Independentei, RO-060032, Bucharest (Romania)

    2008-07-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  13. Low-energy proton increases associated with interplanetary shock waves.

    Science.gov (United States)

    Palmeira, R. A. R.; Allum, F. R.; Rao, U. R.

    1971-01-01

    Impulsive increases in the low energy proton flux observed by the Explorer 34 satellite, in very close time association with geomagnetic storm sudden commencements are described. It is shown that these events are of short duration (20-30 min) and occur only during the decay phase of a solar cosmic-ray flare event. The differential energy spectrum and the angular distribution of the direction of arrival of the particles are discussed. Two similar increases observed far away from the earth by the Pioneer 7 and 8 deep-space probes are also presented. These impulsive increases are compared with Energetic Storm Particle events and their similarities and differences are discussed. A model is suggested to explain these increases, based on the sweeping and trapping of low energy cosmic rays of solar origin by the advancing shock front responsible for the sudden commencement detected on the earth.

  14. Energy performance of the low-energy house in Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Svendsen, Svend

    2005-01-01

    by ventilation heat recovery (90% efficiency) specially designed for arctic conditions, by using thicker insulation in walls (300 mm) and roof/floor (350 mm), and by using solar hot water heating (3250 kWh/year). The building is intended to enhance sustainability in the building sector in Greenland....... energy gain, efficient ventilation system with heat recovery and solar heating. In this paper the results of a calculation of the energy consumption of low-energy house is presented. The calculation was done using the program BSim2002 [1] and a new weather test reference year based on climatic data......The object of the low-energy house in Sisimiut in Greenland was to build a house with an energy consumption less than 80 kWh/m² corresponding to half the energy frame of the coming building code. Therefore the focus in this project has been on large insulation thicknesses, windows with high net...

  15. Revealing low-energy part of the beta spectra

    International Nuclear Information System (INIS)

    Selvi, S.; Celiktas, C.

    2002-01-01

    An effective method is proposed to separate electronic noise from the beta-particle spectra revealing lower energy part of the spectra. The available methods for reducing the noise problem cut the noise along with the low-energy part of the beta spectra by using a discriminator. Our setup eliminates this undesirable effect by shifting the noise toward the lowest energy scale leaving the low-energy part of spectra undisturbed. We achieved this noise-pulse-separation by treating the noise as a pulse so that we can exploit the application of the pulse-shape analyzer equipment used for pulse shape identification of particles and rejection of defective pulses. To the best of our knowledge this method of the noise separation is a novel approach

  16. Challenges in validating radiation sterilization with low energy electron irradiation

    International Nuclear Information System (INIS)

    Miller, A.; Helt-Hansen, J.

    2011-01-01

    Complete text of publication follows. Low energy electron irradiation (80-300 keV) is used increasingly for sterilization or decontamination in connection with isolators for aseptic filling lines in the pharmaceutical industry. It is not defined how validation for this process shall be carried out. A method can be derived from the medical device standard for radiation sterilization, ISO 11137, because the principles described in this standard can be applied to almost any industrial irradiation process. The validations elements are: Process definition, concerning specification of the dose required for the process and the maximum acceptable dose for the product. Installation qualification, concerning acceptance the irradiation facility. Operational qualification, concerning characterization of the facility. Performance qualification, concerning setting up the process. Process control, concerning routine monitoring. The limited penetration of the low energy electrons leads to problems with respect to executing these validation steps. This paper discusses these problems, and shows with examples how they can be solved.

  17. Consumer Unit for Low Energy District Heating Net

    DEFF Research Database (Denmark)

    Paulsen, Otto; Fan, Jianhua; Furbo, Simon

    2008-01-01

    to reduce heat loss in the network. The consumer’s installation is a unit type with an accumulation tank for smoothing the heat load related to the domestic hot water. The building heat load is delivered by an under-floor heating system. The heavy under-floor heating system is assumed to smooth the room...... heat load on a daily basis, having a flow temperature control based on outdoor climate. The unit is designed for a near constant district heating water flow. The paper describes two concepts. The analyses are based on TRNSYS (Klein et al., 2006) simulation, supplied with laboratory verification......A low energy/ low temperature consumer installation is designed and analyzed. The consumer type is a low energy single family house 145 m2 with annual energy consumption in the range of 7000 kWh, incl. domestic hot water in a 2800 degree day climate. The network is an extreme low temperature system...

  18. Low-energy neutral current phenomenology and grand unified theories

    International Nuclear Information System (INIS)

    Del Aguila, F.; Mendez, A.

    1981-01-01

    We derive necessary and sufficient conditions to be satisfied by any expanded electroweak gauge model in order to reproduce the standard model low-energy neutral current predictions. These conditions imply several constraints on the neutral gauge boson masses and the quantum number assignments for the ordinary fermions. Using these conditions, we prove that the popular grand unified theories based on the gauge groups SO(10) and E6 can only accommodate trivial extensions of the standard model. As a consequence, if any of these grand unified models works at some energy scale, present low-energy neutral current phenomenology implies that the Z-boson must be produced with the expected mass and couplings to the ordinary fermions. Any additional neutral gauge boson (with the possible exception of very heavy ones) could only be produced in hadronic collisions and it would not decay in e + e - . (orig.)

  19. The Phobos low energy telescope charged particle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

    1990-05-01

    The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

  20. Luminescence model with quantum impact parameter for low energies

    International Nuclear Information System (INIS)

    Cruz G, H.S.; Michaelian, K.; Galindo U, S.; Martinez D, A.; Belmont M, E.

    2000-01-01

    The analytical model of induced light production in scintillator materials by energetic ions proposed by Michaelian and Menchaca (M-M) adjusts very well the luminescence substance data in a wide energy interval of the incident ions (10-100 MeV). However at low energies, that is, under to 10 MeV, the experimental deviations of the predictions of M-M model, show that the causes may be certain physical effects, all they important at low energies, which were not considered. We have modified lightly the M-M model using the basic fact that the Quantum mechanics gives to a different limit for the quantum impact parameter instead of the classic approximation. (Author)

  1. Comparison Study on Low Energy Physics Model of GEANT4

    International Nuclear Information System (INIS)

    Park, So Hyun; Jung, Won Gyun; Suh, Tae Suk

    2010-01-01

    The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2

  2. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    Science.gov (United States)

    King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.

    2015-11-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.

  3. Negative ions as a source of low energy neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems.

  4. Low energy pion--nucleon and pion--deuteron interactions

    International Nuclear Information System (INIS)

    Burman, R.L.

    1975-01-01

    This survey concentrates upon current experiments in the fields of pion-nucleon and pion-deuteron interactions, for low-energy incident pions--below 300 MeV. The discussion is restricted to very recent work. The topics to be covered are: π +- p → π +- p, Elastic Scattering; π +- p → π +- pγ, Bremsstrahlung; π + d → pp, Absorption; π d → π + d, Elastic Scattering; and π + d → π + pn, Breakup. (14 figures) (U.S.)

  5. Low Energy Supersymmetry from the Heterotic String Landscape

    CERN Document Server

    Lebedev, O; Raby, S; Ramos-Sanchez, S; Ratz, M; Vaudrevange, P K S; Wingerter, A; Lebedev, Oleg; Nilles, Hans-Peter; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K. S.; Wingerter, Akin

    2007-01-01

    We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favoured. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

  6. Low Energy Electron Gun on Board a Scientific Satellite GEOTAIL

    OpenAIRE

    TSUTSUI, Minoru; ONISHI, Yoshiaki; MATSUMOTO, Hiroshi; KIMURA, Iwane; 筒井, 稔; 大西, 嘉昭; 松本, 紘; 木村, 磐根

    1988-01-01

    A low energy electron gun to be used for beam-plasma interaction experiments by a scientific satellite GEOTAIL has been designed and manufactured. Electrodes of the gun have been modified from the Pierce type gun because of the use of a directly heated cathode. Spatial density distributions of beam electrons emitted from the new gun have been measured in a large vacuum chamber, and characteristic curves of emission currents for some beam energies and cathode powers have been checked repeatedl...

  7. Practical Use of Scanning Low Energy Electron Microscope (SLEEM)

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Mikmeková, Eliška; Mikmeková, Šárka; Konvalina, Ivo; Frank, Luděk

    2016-01-01

    Roč. 22, S3 (2016), s. 1650-1651 ISSN 1431-9276 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : scanning low energy * SLEEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  8. The TRIUMF low energy pion spectrometer and channel

    International Nuclear Information System (INIS)

    Sobie, R.J.; Drake, T.E.; Barnett, B.M.; Erdman, K.L.; Gyles, W.; Johnson, R.R.; Roser, H.W.; Tacik, R.; Blackmore, E.W.; Gill, D.R.

    1983-08-01

    A low energy pion spectrometer has been developed for use with the TRIUMF M13 pion channel. The combined channel and spectrometer resolution is presently 1.1 MeV at T = 50 MeV. This is limited by the amount of gas and detector material in the spectrometer in addition to the inherent resolution of the channel. Improvements to both the spectrometer and channel are discussed

  9. Delayed hot spots in a low energy plasma focus

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1991-01-01

    In a low energy Mather-type plasma focus device, hot spots having temperature in the range of few keV have been observed even 1 μs after the pinch disintegration and in regions away from the pinch area. These hot spots are perhaps created by the thermal runaway due to temperature fluctuations in the background gas. (author). 12 refs., 6 figs

  10. Programs for low-energy nuclear physics data processing

    International Nuclear Information System (INIS)

    Antuf'ev, Yu.P.; Dejneko, A.S.; Ekhichev, O.I.; Kuz'menko, V.A.; Mashkarov, Yu.G.; Nemashkalo, B.A.; Skakun, E.A.; Storizhko, V.E.; Shlyakhov, N.A.

    1978-01-01

    Purpose of six computer programs developed in KhPTI of AN USSR for the processing of the experimental data on low energy nuclear physics ia friendly described. The programs are written in Algol-60 language. They are applied to some types of nuclear reactions and permit to process differential cross sections and γ spectra, to compute statistical tensors and excitation functions as well as to analyze some processes by means of theoretical models

  11. Radiation processing of natural polymers using low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2004-01-01

    Radiation processing is widely used in Japan and the economic scale of radiation application amounted to about 71 b$ (ratio relative to GDP: 1.7%) in total. It consisted of 60 b$ (85%) in industry, 10 b$ (14%) in medicine and 1 b$ (1%) in agriculture. Irradiation using gamma-ray from 60 Co and electron beam is commercially used for the sterilization and modification of materials. Utilization of natural polymers by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin were easily degraded by irradiation and induced various kinds of biological activities, i.e. anti-bacterial activity, elicitor activity, plant growth promotion, suppression of environmental stress on plants. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. Low energy electron beam (EB) irradiation has a variety of applications and good safety. A self-shielded low energy electron accelerator system needs an initial investment much lower than a 60 Co facility. It was demonstrated that the liquid sample irradiation system using low energy EB was effective not only for the preparation of degraded polysaccharides but also for radiation vulcanization of natural rubber latex (RVNRL). Some carbohydrate derivatives, carboxymethylcellulose (CMC), carboxymethyl-starch and carboxymethyl-chitin/chitosan, can be crosslinked under certain radiation condition and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  12. Method of making a low energy gamma ray collimator

    International Nuclear Information System (INIS)

    Muehllehner, Gerd.

    1975-01-01

    Described herein is a method for making a low energy gamma ray collimator which involves corrugating lead foil strips by passing them through pinion wire rollers and gluing corrugated strips between straight strips using an adhesive such as epoxy to build up a honeycomb-like structure. A thin aluminum sheet is glued to both edges of the strips to protect them and to provide a more rigid assembly which may be sawed to a desired shape. (Patent Office Record)

  13. Negative ions as a source of low energy neutral beams

    International Nuclear Information System (INIS)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems

  14. Sausage instability threshold in a low energy plasma focus

    International Nuclear Information System (INIS)

    Zakaullah, M.; Nasir, M.; Khattak, F.Y.; Murtaza, G.

    1993-01-01

    Development of sausage instability (m = 0 mode) is studied in a small low energy Mather-type plasma focus. A shadow graphic study of the current sheath has shown that the focused plasma necks off during the radial phase before the maximum compression. This may indicate the lowering of the instability threshold. Three hook-type structures are observed which may not be due to the multifoci formation. The bubble shape structure is observed to be developed in the expansion phase. (author)

  15. Low energy He+ irradiation effect on graphite surface

    International Nuclear Information System (INIS)

    Asari, E.; Nakamura, K.G.; Kitajima, M.; Kawabe, T.

    1992-01-01

    Study on the lattice disordering and the secondary electron emission under low energy (1-5keV) He + irradiation is reported. Real-time Raman measurements show that difference in the observed Raman spectra for different ion energies is due to the difference of the damage depth. The relation between the observed Raman spectrum and the depth profile of lattice damage is discussed. Energy dependence of the secondary electron emission coefficient are also described. (author)

  16. Low-energy phenomenology of a realistic composite model

    International Nuclear Information System (INIS)

    Korpa, C.; Ryzak, Z.

    1986-01-01

    The low-energy limit of the strongly coupled standard model (Abbott-Farhi composite model) is analyzed. The effects of the excited W isotriplet and isoscalar bosons are investigated and compared with experimental data. As a result, constraints on parameters (masses, coupling constants, etc.) of these vector bosons are obtained. They are not severe enough (certain cancellations are possible) to exclude the model on experimental basis

  17. Overview of Light Hydrogen-Based Low Energy Nuclear Reactions

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.

    This paper reviews light water and hydrogen-based low-energy nuclear reactions (LENRs) including the different methodologies used to study these reactions and the results obtained. Reports of excess heat production, transmutation reactions, and nuclear radiation emission are cited. An aim of this review is to present a summary of the present status of light water LENR research and provide some insight into where this research is heading.

  18. Elastic scattering of low energy electrons by hydrogen molecule

    International Nuclear Information System (INIS)

    Freitas, L.C.G.; Mu-Tao, L.; Botelho, L.F.

    1987-01-01

    The coherent version of the Renormalized Multiple-Centre Potential Model (RMPM) has been extended to treat the elastic scattering of low energy electrons by H2 molecule. The intramolecular Multiple Scattering (MS) effect has also been included. The comparison against the experimental data shows that the inclusion of the MS improves significantly with experiment. The extension of the present method to study electron-polyatomic molecule interaction is also discussed. (author) [pt

  19. Generation of low-energy muons with laser resonant ionization

    International Nuclear Information System (INIS)

    Matsuda, Y.; Bakule, P.; Iwasaki, M.; Matsuzaki, T.; Miyake, Y.; Ikedo, Y.; Strasser, P.; Shimomura, K.; Makimura, S.; Nagamine, K.

    2006-01-01

    We have constructed a low-energy muSR spectrometer at RIKEN-RAL muon facility in ISIS, the UK. With low-background of pulsed muon beam, and short pulse width from laser resonant ionization method, it is hoped this instrument will open new possibilities for studies of material sciences with muon beam. It is enphasized that this method is well suited to the facility where intense pulsed proton beam is available

  20. Low Energy Contrast of Metal Matrix Composite in SEM

    Czech Academy of Sciences Publication Activity Database

    Frank, Luděk; Matsuda, K.; Hrnčiřík, Petr; Müllerová, Ilona

    2003-01-01

    Roč. 9, Sup. 3 (2003), s. 328 - 329 ISSN 1431-9276. [MC 2003. Dresden, 07.09.2003-12.09.2003] R&D Projects: GA AV ČR IAA1065304 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy contrasts * scanning electron microscope * aluminium alloys Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.648, year: 2003

  1. Nuclear reactions video (knowledge base on low energy nuclear physics)

    International Nuclear Information System (INIS)

    Zagrebaev, V.; Kozhin, A.

    1999-01-01

    The NRV (nuclear reactions video) is an open and permanently extended global system of management and graphical representation of nuclear data and video-graphic computer simulation of low energy nuclear dynamics. It consists of a complete and renewed nuclear database and well known theoretical models of low energy nuclear reactions altogether forming the 'low energy nuclear knowledge base'. The NRV solves two main problems: 1) fast and visualized obtaining and processing experimental data on nuclear structure and nuclear reactions; 2) possibility for any inexperienced user to analyze experimental data within reliable commonly used models of nuclear dynamics. The system is based on the realization of the following principal things: the net and code compatibility with the main existing nuclear databases; maximal simplicity in handling: extended menu, friendly graphical interface, hypertext description of the models, and so on; maximal visualization of input data, dynamics of studied processes and final results by means of real three-dimensional images, plots, tables and formulas and a three-dimensional animation. All the codes are composed as the real Windows applications and work under Windows 95/NT

  2. Low Energy Electrons in the Mars Plasma Environment

    Science.gov (United States)

    Link, Richard

    2001-01-01

    The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although electron fluxes were estimated from changes in the ion currents. Using these derived low-energy electron fluxes, Mantas and Hanson studied the photoelectron and the solar wind electron interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy electron fluxes in the vicinity of the Mars plasma boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/Electron Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to electron impact ionization of exospheric neutral species by solar wind electrons. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (internal (photoelectron) sources of ionization, and accounts for Auger electron production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining plasma densities in the region of the Mars plasma boundary.

  3. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1991-01-01

    A major accomplishment of this project in the past year is the completion of a fairly comprehensive paper describing the survey of radiative capture reactions of protons on light nuclei at low energies. In addition we have completed a preliminary set of measurements of (d,p)/(d,α) cross section ratios on the charge symmetric nuclei 6 Li and 10 B as a test of the Oppenheimer-Phillips effect. While the 6 Li data remain inconclusive, the 10 B data show solid evidence for the Oppenheimer-Phillips enhancement of the (d,p) reaction relative to the (d,α) reaction for deuteron bombarding energies below about 100 keV. We have continued our investigation of fusion reaction products from deuterium-metal systems at room temperatures with the startling observation of intense burst of energetic charged particles from deuterium gas loaded thin titaium foils subject to non-equilibrium thermal and electrical conditions. We have completed two projects involving the application of the low energy particle accelerator to material science problems; firstly a study of the transformation of crystalline to amorphous Fe-Zr systems by proton irradiation and secondly the effects of ion bombardment on the critical temperature of YBCO high-temperature superconductors. Finally we have made progress in several instrumentation projects which will be used in some of the up-coming measurements of nuclear cross sections at very low energies

  4. Ultra-low energy storage ring at FLAIR

    International Nuclear Information System (INIS)

    Welsch, Carsten P.; Papash, A. I.; Gorda, O.; Harasimowicz, J.; Karamyshev, O.; Karamysheva, G.; Newton, D.; Panniello, M.; Putignano, M.; Siggel-King, M. R. F.; Smirnov, A.

    2012-01-01

    The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV and possibly less. The USR has been completely redesigned over the past three years. The ring structure is based on a “split achromat” lattice that allows in-ring experiments with internal gas jet target. Beam parameters might be adjusted in a wide range: from very short pulses in the nanosecond regime to a Coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Detailed investigations of the USR, including studies into the ring’s long term beam dynamics, life time, equilibrium momentum spread and equilibrium lateral spread during collisions with an internal target were carried out. New tools and beam handling techniques for diagnostics of ultra-low energy ions at beam intensities less than 10 6 were developed by the QUASAR Group. In this paper, progress on the USR project will be presented with an emphasis on the expected beam parameters available to the experiments at FLAIR.

  5. Energy sharing and sputtering in low-energy collision cascades

    International Nuclear Information System (INIS)

    Weller, R.A.; Weller, M.R.

    1982-01-01

    Using a non-linear transport equation to describe the energy-sharing process in an isotropic collision cascade, we have numerically calculated sputtered particle velocity spectra for several very low energy (=< 10 eV) primary recoil distributions. Our formulation of the sputtering process is essentially that used in the linear model and our equations yield the familiar linear model results in the appropriate limit. Discrepancies between our calculations and the linear model results in other cases may be understood by considering the effects of the linear model assumptions on the sputtering yield at very low energies. Our calculations are also compared with recent experimental results investigating ion-explosion sputtering. The results of this comparison support the conclusion that in insulators sputtering is initiated by very low energy recoil atoms when the energy of the incident beam is high enough that the stopping power is dominated by the electronic contribution. The calculations also suggest that energy spectra similar to those for evaporation may result from non-equilibrium processes but that the apparent temperatures of evaporation are not related in a simple way to any real temperature within the target. (author)

  6. Improving Indoor Localization Using Bluetooth Low Energy Beacons

    Directory of Open Access Journals (Sweden)

    Pavel Kriz

    2016-01-01

    Full Text Available The paper describes basic principles of a radio-based indoor localization and focuses on the improvement of its results with the aid of a new Bluetooth Low Energy technology. The advantage of this technology lies in its support by contemporary mobile devices, especially by smartphones and tablets. We have implemented a distributed system for collecting radio fingerprints by mobile devices with the Android operating system. This system enables volunteers to create radio-maps and update them continuously. New Bluetooth Low Energy transmitters (Apple uses its “iBeacon” brand name for these devices have been installed on the floor of the building in addition to existing WiFi access points. The localization of stationary objects based on WiFi, Bluetooth Low Energy, and their combination has been evaluated using the data measured during the experiment in the building. Several configurations of the transmitters’ arrangement, several ways of combination of the data from both technologies, and other parameters influencing the accuracy of the stationary localization have been tested.

  7. Scanning ion microscopy with low energy lithium ions

    International Nuclear Information System (INIS)

    Twedt, Kevin A.; Chen, Lei; McClelland, Jabez J.

    2014-01-01

    Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500 eV to 5 keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process. - Highlights: • We use an ion source based on photoionization of laser-cooled lithium atoms. • The ion source makes possible a low energy (500 eV to 5 keV) scanning ion microscope. • Low energy is preferred for ion microscopy with backscattered ions. • We use the microscope to image a thin resist used in nano-imprint lithography

  8. Status of photonuclear method of analysis among other nuclear analytical methods and main fields of its application

    International Nuclear Information System (INIS)

    Burmistenko, Yu.N.

    1986-01-01

    Technical, organizational and economical aspects as applied to the field of application of photonuclear methods of analysis of substance composition are considered. As for the technical aspect, the most important factors are nuclear-physical characteristics of the elements under determination and the elements composing the sample matrix. As for the organizational aspect, the governing factor in a number of cases is the availability of an irradiation device in the close vicinity of the analytical laboratory. Studying the technical and organizational aspects while choosing the proper method one can obtain the main source data to perform feasibility studies of a nuclear analytical complex with this or that activation source. Therefore, the economical aspect is governing for the choice of the method

  9. Developing effective rockfall protection barriers for low energy impacts

    Science.gov (United States)

    Mentani, Alessio; Giacomini, Anna; Buzzi, Olivier; Govoni, Laura; Gottardi, Guido; Fityus, Stephen

    2016-04-01

    Recently, important progresses have been made towards the development of high capacity rockfall barriers (100 kJ - 8000 kJ). The interest of researchers and practitioners is now turning to the development of fences of minor capacity, whose use becomes essential in areas where rockfall events generally have low intensity and the use of high capacity barriers would be accompanied by excessive costs and high environmental impact. Low energy barriers can also provide a cost-effective solution even in areas where high energies events are expected. Results of full-scale tests are vital to any investigation on the behaviour of these structures. An experimental set-up has been developed at The University of Newcastle (AUS), to investigate the response of low energy rockfall barrier prototypes to low energy impacts. The Australian territory, and in particular New South Wales, is in fact characterised by rockfall events of low-to-medium intensity (50 kJ - 500 kJ) and the need of protection structures working within such energy range, is particularly felt [1]. The experiments involved the impact of a test block onto three spans, low energy barrier prototypes, made of steel structural posts, fully fixed at the base, side cables and a steel meshwork constituted by a double twist hexagonal wire net [2]. Test data enabled the development, calibration and assessment of FE models [3], on which non-linear and dynamic analyses have been performed addressing the effect of the block size. Results have shown that the response of the structure is strongly governed by the net. Data from tests conducted on the sole net and on the entire barrier showed in fact a similar trend, different to what typically observed for high capacity barriers, whose behaviour is also led by the presence of uphill cables and brakes. In particular, the numerical analyses have demonstrated a dependence of the net performance on the block size. In particular, a loss of capacity in the order of 50% occurred as the

  10. Low-energy electron microdosimetry of CS-137

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Wrenn, M.E.

    1980-09-01

    The mass of tissue irradiated by an internal emitter depends upon the distribution of the radionuclide within the organism and the type of radiation emitted. The range (95% absorption) of low-energy electron effectively defines the sensitive volume in which the energy of the emitted electron is deposited. Accordingly, in the case of Auger electron microdosimetry of internal emitters the correct definition of the sensitive volume is of paramount importance. The amount of energy delivered by the monoenergetic electrons emitted by the decay system 137 Cs → sup(137m)Ba to spherical volumes of water-like tissue media of radii equivalent to the estimated ranges of those electrons in water is calculated and discussed as far as the variations of the estimated ranges of electrons as a function of the initial energy of emission are concerned. Although there are still many uncertainties on the actual ranges of low-energy electrons, one can state confidently that the ranges of the Auger electrons of the decay system 137 Cs → 137 sup(m) Ba → 137 Ba can be considered to be in the same order of magnitude of the diameter of a cell. The energy deposition in spherical volumes of water-like tissue media, considered equivalent to the sensitive volumes for the Auger electrons of the decay system 137 Cs → 137 sub(m) Ba → 137 Ba, range for several orders of magnitude from 10 2 to about 10 10 times higher than the energy deposition in similar media by the internal conversion electrons of this decay system. If equivalent variations of energy deposition per unit mass occur when the masses considered are cellular, and subcellular structures, then the effects into the sensitive volume should be taken into biological consideration as far as the microdosimetry of low-energy electrons (approximately equal to 10 keV) is considered, whenever there is internal localization of Auger emitters. (Author) [pt

  11. Clinical application of low energy intracardiac cardioversion of atrial fibrillation

    International Nuclear Information System (INIS)

    Wu Liqun; Gu Gang; Su Kan; Su Renying; Shen Yongchu; Shen Weifeng

    2002-01-01

    Objective: To evaluate the efficacy and safety of low energy intracardiac cardioversion in persistent atria fibrillation. Methods: Low energy intracardiac cardioversion was performed by delivering R wave-synchronized biphasic shocks in 7 patients (4 men, 3 women) with persistent atrial fibrillation. Prior to the procedure, all patients underwent transesophageal echocardiographic examinations to rule out the presence of intracardiac thrombus and received subcutaneous injection of low molecular weight heparin for 3-5 days. Two custom-made 6 Fr catheters (Rhythm Technologies of Getz, USA) were used for de-fibrillation shock delivery. One catheter was positioned in the lower right atrium so that the majority of the catheter electrodes had firm contact with the right atrial free wall. The second catheter was placed randomly either in coronary sinus through right internal jugular vein or in the left pulmonary artery through femoral vein. In addition, a standard diagnostic 6-F quadrupolar catheter was placed at the right ventricular apex for ventricular synchronization and postshock ventricular pacing. Shocks were delivered by Implant Support Device (Model 4510, Teleceronics). After conversion, all patients were treated with intravenous amiodarone in the first 24 hours followed by oral administration. Results: In all 7 patients cardioversion of atrial fibrillation to sinus rhythm was successfully obtained. A mean of 2 ± 1 shocks per patient has been delivered with a total amount of 13 shocks. The average delivered energy was 7.8 ± 2.2 Joules. No complication occurred. At a mean follow-up of 18 ± 9 months, 4 of the 7 patients treated successfully showed sinus rhythm there after. Atrial fibrillation recurred in 3 patients at the second, fifth day and eighth month after cardioversion. Conclusions: Low energy intracardiac cardioversion is effective and safe, and can be easily performed in patients without general anesthesia. It offers a new option for restoring sinus

  12. Low energy electron beam processing of YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chromik, Š., E-mail: stefan.chromik@savba.sk [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Camerlingo, C. [CNR-SPIN, Istituto Superconduttori, Materiali Innovativi e Dispositivi, via Campi Flegrei 34, 80078 Pozzuoli (Italy); Sojková, M.; Štrbík, V.; Talacko, M. [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Malka, I.; Bar, I.; Bareli, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Jung, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-02-15

    Highlights: • Improvement of superconducting properties of irradiated bridges under certain conditions. • 30 keV irradiation influence CuO{sub 2} planes as well as oxygen chains. • Direct confirmation of changes in oxygen chains using micro-Raman spectroscopy. • Possibility of electron writing. - Abstract: Effects of low energy 30 keV electron irradiation of superconducting YBa{sub 2}Cu{sub 3}O{sub 7−δ} thin films have been investigated by means of transport and micro-Raman spectroscopy measurements. The critical temperature and the critical current of 200 nm thick films initially increase with increasing fluency of the electron irradiation, reach the maximum at fluency 3 − 4 × 10{sup 20} electrons/cm{sup 2}, and then decrease with further fluency increase. In much thinner films (75 nm), the critical temperature increases while the critical current decreases after low energy electron irradiation with fluencies below 10{sup 20} electrons/cm{sup 2}. The Raman investigations suggest that critical temperature increase in irradiated films is due to healing of broken Cu−O chains that results in increased carrier’s concentration in superconducting CuO{sub 2} planes. Changes in the critical current are controlled by changes in the density of oxygen vacancies acting as effective pinning centers for flux vortices. The effects of low energy electron irradiation of YBCO turned out to result from a subtle balance of many processes involving oxygen removal, both by thermal activation and kick-off processes, and ordering of chains environment by incident electrons.

  13. EPIDEMIOLOGICAL STUDY OF LOW ENERGY FRACTURES IN REPUBLIC OF ARMENIA

    Directory of Open Access Journals (Sweden)

    S. Saakyan

    2017-01-01

    Full Text Available Until present no data was available inArmeniain respect of incidence of low energy fractures that are typical of osteoporotic locations which consequently did not allow to evaluate the scope of this problem across the country.Purpose of the study – to identify the incidence of low energy fractures in proximal femur, in distal forearm, in proximal humerus and in distal tibia across population ofArmenia aged 50 years and older.Materials and methods. An observing population study was performed in two regions of Armenia during 2011-2013 where the frequency of selected locations in cases of moderate trauma was identified. During 2011-2012 the information was collected based on traumatology service records adding in 2013 other sources including primary level of healthcare due to observed infrequent applications for medical help in cases of trauma. Results. In 2013 the incidence of proximal femur fractures in men was reported as 136 cases per 100 000 of population aged 50 years and older, in women – 201 cases per 100 000. At the same time only 57.7% of patients with proximal femur fractures were admitted to hospital. Distal forearm fractures incidence in men and women was observed correspondingly 56/100 000 and 176/100 000 cases, proximal humerus fractures – 39/100 000 and 86/100 000 cases and distal tibia fractures – 39/100 000 and 86/100 000 cases. The predicted annual number of proximal femur fracture in Armenia amounts to 2067 cases, distal forearm fractures – 1205, proximal humerus fractures – 640.Conclusion. Epidemiological data that was collected for the first time on low energy fractures incidence confirmed the acute osteoporosis issue inArmenia and revealed the problems in organization of medical care for the group of senior patients with injuries.

  14. Collisions between low-energy antihydrogen and atoms

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Chamberlain, C.W.; Liu, Y.; Martin, G.D.R.

    2004-01-01

    Antihydrogen is currently the subject of great interest as cold H-bar has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH-bar scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H-bar system and give a progress report on the calculation that we are currently carrying out for this system

  15. Use of a streamer chamber for low energy nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Van Bibber, K.; Pang, W.; Avery, M.; Bloemhof, E.

    1979-10-01

    A small streamer chamber has been implemented for low energy heavy ion reaction studies at the LBL 88-inch cyclotron. The response of the chamber to light and heavy ions below 35 MeV/nucleon has been examined. The limited sensitivity of light output as a function of ionization works to advantage in recording a wide variety of tracks in the same photograph whose energy loss may vary considerably. Furthermore, as gas targets are attractive for several reasons, we have investigated the suitability of Ar and Xe for use in streamer chambers.

  16. Use of a streamer chamber for low energy nuclear physics

    International Nuclear Information System (INIS)

    Van Bibber, K.; Pang, W.; Avery, M.; Bloemhof, E.

    1979-10-01

    A small streamer chamber has been implemented for low energy heavy ion reaction studies at the LBL 88-inch cyclotron. The response of the chamber to light and heavy ions below 35 MeV/nucleon has been examined. The limited sensitivity of light output as a function of ionization works to advantage in recording a wide variety of tracks in the same photograph whose energy loss may vary considerably. Furthermore, as gas targets are attractive for several reasons, we have investigated the suitability of Ar and Xe for use in streamer chambers

  17. MITP Workshop on Low-Energy Precision Physics

    CERN Document Server

    2013-01-01

    The scientific program will be focussed on the theory of low-energy precision physics relevant to the MESA and TRIGA initiatives. Topics include searches for TeV-scale physics beyond the Standard Model via ultra-precise measurements of parity-violating electron scattering asymmetries, determinations of neutron decay parameters via precision measurements of its lifetime and decay asymmetries, and searches for EDMs of nucleons, nuclei and atoms. The necessary high-precision theoretical tools to analyse these experiments, which include advanced calculations of radiative corrections, will be explored and developed.

  18. Energy loss and thermalization of low-energy electrons

    International Nuclear Information System (INIS)

    LaVerne, J.A.; Mozumder, A.; Notre Dame Univ., IN

    1984-01-01

    Various processes involved in the moderation of low-energy electrons (< 10 keV in energy) have been delineated in gaseous and liquid media. The discussion proceeds in two stages. The first stage ends and the second stage begins when the electron energy equals the first excitation potential of the medium. The second stage ends with thermalization. Cross sections for electronic excitation and for the excitation (and de-excitation) of sub-electronic processes have been evaluated and incorporated in suitable stopping power and transport theories. Comparison between experiment and theory and intercomparisons between theories and experiments have been provided where possible. (author)

  19. Shock waves in water at low energy pulsed electric discharges

    International Nuclear Information System (INIS)

    Pinchuk, M E; Kolikov, V A; Rutberg, Ph G; Leks, A G; Dolinovskaya, R V; Snetov, V N; Stogov, A Yu

    2012-01-01

    Experimental results of shock wave formation and propagation in water at low energy pulsed electric discharges are presented. To study the hydrodynamic structure of the shock waves, the direct shadow optical diagnostic device with time resolution of 5 ns and spatial resolution of 0.1 mm was designed and developed. Synchronization of the diagnostic and electrodischarge units by the fast optocouplers was carried out. The dependences of shock wave velocities after breakdown of interelectrode gap for various energy inputs (at range of ≤1 J) into discharge were obtained. Based on the experimental results the recommendations for the adjustment parameters of the power supply and load were suggested.

  20. Interpretation of diffuse low-energy electron diffraction intensities

    International Nuclear Information System (INIS)

    Saldin, D.K.; Pendry, J.B.; Van Hove, M.A.; Somorjai, G.A.

    1985-01-01

    It is shown that the diffuse low-energy electron diffraction (LEED) that occurs between sharp LEED beams can be used to determine the local bonding configuration near disordered surface atoms. Two approaches to the calculation of diffuse LEED intensities are presented for the case of lattice-gas disorder of an adsorbate on a crystalline substrate. The capabilities of this technique are most similar to those of near-edge extended x-ray absorption fine structure, but avoid the restrictions due to the use of photons

  1. Low-energy house in Sisimiut - Data overview

    Energy Technology Data Exchange (ETDEWEB)

    Hvidthoeft Delff Andersen, P.; Rode, C.; Madsen, Henrik

    2013-08-15

    Experiments with persistently exciting heat inputs are a fundamental tool in identification of heat dynamics in buildings. The Low-energy house in Sisimiut, Greenland, provides an advanced experimental setup with frequent measurements of temperatures, heat inputs, and much more. This paper presents an overview of data collected since the installation of the new measurement and control system. Focus is on heat dynamics so only data related to that will be shown. 5 experiments have been conducted. They are described, and resulting data is shown. (Author)

  2. Degradation of vitamin C by low-energy electrons

    Science.gov (United States)

    Abdoul-Carime, Hassan; Illenberger, Eugen

    2004-06-01

    We report on the degradation of gas phase vitamin C (ascorbic acid, AA) induced by low-energy electrons. In the energy range of (0-12) eV, different negatively charged fragments, attributed to the dehydro-ascorbic acid anion ((AA-H) -), OH -, O - and H -, are observed. The yield functions indicate that these ions are formed via dissociative electron attachment, DEA. While the formation of (AA-H) - is exclusively observed at sub-excitation energies (<1.5 eV), the other fragments arise from resonance features at higher energies. Possible implications of these observations for radiation damage and food treatment by high energy radiation are considered.

  3. Low energy, low cost, efficient CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Trachtenberg; Lihong Bao; David A. Smith; Remy Dumortier [Carbozyme, Inc., Monmouth Junction, NJ (United States)

    2006-07-01

    This paper discusses the development and some characteristics of a new, enzyme-based, contained liquid membrane contactor to capture CO{sub 2}. The enzyme carbonic anhydrase catalyzes the removal of CO{sub 2} while the membrane contactor increases the surface area to allow the reduction of the size of the system. The modular system design is easily scaled to any required size reducing the investment costs. The system captures CO{sub 2} at a low energy and low cost promising to be a cost effective technology for CO{sub 2} capture. 5 refs., 7 figs.

  4. Collisions between low-energy antihydrogen and atoms

    Energy Technology Data Exchange (ETDEWEB)

    Armour, E.A.G. E-mail: edward.armour@nottingham.ac.uk; Chamberlain, C.W.; Liu, Y.; Martin, G.D.R

    2004-07-01

    Antihydrogen is currently the subject of great interest as cold H-bar has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH-bar scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H-bar system and give a progress report on the calculation that we are currently carrying out for this system.

  5. Measurements of low energy neutral hydrogen efflux during ICRF heating

    International Nuclear Information System (INIS)

    Cohen, S.A.; Ruzic, D.; Voss, D.E.

    1984-09-01

    Using the Low Energy Neutral Atom Spectrometer, measurements were made of the H 0 and D 0 efflux from PLT during ion cyclotron heating experiments. The application of rf power at frequencies appropriate to fundamental and 2nd-harmonic heating results in a rapid, toroidally uniform rise in the charge-exchange efflux at a rate of about 10 15 cm -2 s -1 MW -1 . This flux increase is larger at lower plasma currents. The cause of this flux and its impact on plasma behavior are discussed

  6. Radiation degradation of marine polysaccharides by low energy electron beam

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Nagasawa, Naotsugu; Kume, Tamikazu

    2003-01-01

    The radiation degradations of marine polysaccharides by both gamma Co-60 and electron beam irradiations are investigated. Polysaccharides and oligosaccharides can be produced by degradation of corresponding polysaccharides including marine polysaccharides such as alginates, chitin chitosan and carrageenan. The viscosity of alginate, chitosan and carrageenan solution decreases markedly with increase of the low energy electron beam irradiation time and the beam current. Furthermore, the viscosity is reduced sharply in short time for polysaccharide solution with low concentration, for instance carrageenan solution of 1%. (author)

  7. Treatment of surfaces with low-energy electrons

    Czech Academy of Sciences Publication Activity Database

    Frank, Luděk; Mikmeková, Eliška; Lejeune, M.

    2017-01-01

    Roč. 407, JUN 15 (2017), s. 105-108 ISSN 0169-4332 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Low- energy electrons * Electron beam induced release * Graphene * Ultimate cleaning of surfaces Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Nano-processes (applications on nano-scale) Impact factor: 3.387, year: 2016

  8. The Low Energy Level Structure of {sup 191}lr

    Energy Technology Data Exchange (ETDEWEB)

    Malmskog, S G; Berg, V [AB Atomenergi, Nykoeping (Sweden); [Inst. of Physics, U niv. of Stockholm (Sweden); Baecklin, A; Hedin, G [Inst. of Physics, Univ. of Upp sala (Sweden)

    1970-02-15

    The decay of {sup 191}Pt to {sup 191}Ir has been investigated using Ge(Li)-detectors and a double focusing beta spectrometer. 35 transitions were observed and most of them were placed in a level scheme. Special attention was given to the low energy level band structure. Several multipolarity mixing ratios were determined from L-subshell ratio measurements. Using the delayed coincidence technique the half-life of the 179.05 keV level was measured to 40 {+-} 12 psec. The low level decay properties are discussed in terms of the Nilsson model with the inclusion of Coriolis coupling.

  9. GEANT4 simulations for low energy proton computerized tomography

    International Nuclear Information System (INIS)

    Milhoretto, Edney; Schelin, Hugo R.; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A.; Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O.; Lopes, Ricardo T.; Vinagre Filho, Ubirajara M.

    2010-01-01

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  10. GEANT4 simulations for low energy proton computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Milhoretto, Edney [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O. [Polytechnic Institute/UERJ, Rua Alberto Rangel s/n, N. Friburgo, RJ, Brazil 28630-050 (Brazil); Lopes, Ricardo T. [Nuclear Instr. Lab./COPPE/UFRJ, Av. Horacio Macedo 2030, Rio de Janeiro-RJ (Brazil); Vinagre Filho, Ubirajara M. [Institute of Nuclear Engineering-IEN/CNEN, Rua Helio de Almeida 75, Rio de Janeiro-RJ (Brazil)

    2010-04-15

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  11. A simple model for low energy ion-solid interactions

    International Nuclear Information System (INIS)

    Mohajerzadeh, S.; Selvakumar, C.R.

    1997-01-01

    A simple analytical model for ion-solid interactions, suitable for low energy beam depositions, is reported. An approximation for the nuclear stopping power is used to obtain the analytic solution for the deposited energy in the solid. The ratio of the deposited energy in the bulk to the energy deposited in the surface yields a ceiling for the beam energy above which more defects are generated in the bulk resulting in defective films. The numerical evaluations agree with the existing results in the literature. copyright 1997 American Institute of Physics

  12. Low-energy CZT detector array for the ASIM mission

    DEFF Research Database (Denmark)

    Cenkeramaddi, Linga Reddy; Genov, Georgi; Kohfeldt, Anja

    2012-01-01

    In this article we introduce the low-energy CZT (CdZnTe) 16 384-pixel detector array on-board the Atmosphere Space Interaction Monitor (ASIM), funded by the European Space Agency. This detector is a part of the larger Modular X-and Gamma-ray sensor (MXGS). The CZT detector array is sensitive...... to photons with energies between 15 keV and 400 keV. The principal objective of the MXGS instrument is to detect Terrestrial Gamma ray Flashes (TGFs), which are related to thunderstorm activity. The concept of the detector array is presented, together with brief descriptions of its mechanical structure...

  13. The low energy tagger for the KLOE-2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Babusci, D. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Bini, C. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Ciambrone, P.; Corradi, G. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); De Santis, A.; De Zorzi, G.; Di Domenico, A. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Fiore, S., E-mail: salvatore.fiore@roma1.infn.i [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Gauzzi, P. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Iannarelli, M.; Miscetti, S.; Paglia, C.; Tagnani, D.; Turri, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy)

    2010-05-21

    The KLOE experiment at the upgraded DAFNE e{sup +}e{sup -} collider in Frascati (KLOE-2) is going to start a new data taking at the beginning of 2010 with its detector upgraded with a tagging system for the identification of gamma-gamma interactions. The tagging stations for low-energy e{sup +}e{sup -} will consist in two calorimeters placed between the beam-pipe outer support structure and the inner wall of the KLOE drift chamber. This calorimeter will be made of LYSO crystals readout by Silicon Photomultipliers, to achieve an energy resolution better than 8% at 200 MeV.

  14. Nuclear data and low energy nuclear research in Israel

    International Nuclear Information System (INIS)

    Yiftah, S.

    1978-07-01

    The Israel Nuclear Data and Low Energy Nuclear Research relevant to the International Nuclear Data Committee was continued in the various institutions listed in previous Progress Reports (LS-270 for 1976). The latest major experimental facility, the 14 UD pelletron, was installed in the Koffler Accelerator Tower at the Weizmann Institute of Science, Rehovot, and accepted on April 1st 1977. A report in Revue de Physique Appliquee of October 1977 including a description of the facility, acceptance performance, as well as some supplementary devices, is reproduced in the beginning of this report. Brief abstracts of the research work, both published and unpublished, are presented. (author)

  15. The interaction of low-energy electrons with fructose molecules

    Science.gov (United States)

    Chernyshova, I. V.; Kontrosh, E. E.; Markush, P. P.; Shpenik, O. B.

    2017-11-01

    Using a hypocycloidal electronic spectrometer, the interactions of low energy electrons (0-8.50 eV) with fructose molecules, namely, electron scattering and dissociative attachment, are studied. The results of these studies showed that the fragmentation of fructose molecules occurs effectively even at an electron energy close to zero. In the total electron-scattering cross section by molecules, resonance features (at energies 3.10 and 5.00 eV) were first observed near the formation thresholds of light ion fragments OH- and H-. The correlation of the features observed in the cross sections of electron scattering and dissociative attachment is analyzed.

  16. Selected challenges in low-energy QCD and hadron physics

    Energy Technology Data Exchange (ETDEWEB)

    Weise, Wolfram [Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany)

    2009-11-15

    This presentation briefly addresses three basic issues of low-energy QCD: first, whether the Nambu-Goldstone scenario of spontaneous chiral symmetry breaking is well established; secondly, whether there is a dynamical entanglement of the chiral and deconfinement crossover transitions in QCD; and thirdly, what is the status of knowledge about the phase diagram of QCD at low temperature and non-zero baryon density. These three topics were injected as key words into a panel discussion at the Schladming school on Challenges in QCD. The following exposition reflects the style and character of the discussions, with no claim of completeness.

  17. Qt based control system software for Low Energy Accelerator Facility

    International Nuclear Information System (INIS)

    Basu, A.; Singh, S.; Nagraju, S.B.V.; Gupta, S.; Singh, P.

    2012-01-01

    Qt based control system software for Low Energy Accelerating Facility (LEAF) is operational at Bhabha Atomic Research Centre (BARC), Trombay, Mumbai. LEAF is a 50 keV negative ion electrostatic accelerator based on SNICS ion source. Control system uses Nokia Trolltech's QT 4.x API for control system software. Ni 6008 USB based multifunction cards has been used for control and read back field equipments such as power supplies, pumps, valves etc. Control system architecture is designed to be client server. Qt is chosen for its excellent GUI capability and platform independent nature. Control system follows client server architecture. The paper will describe the control system. (author)

  18. Early forest fire detection using low-energy hydrogen sensors

    Directory of Open Access Journals (Sweden)

    K. Nörthemann

    2013-11-01

    Full Text Available Most huge forest fires start in partial combustion. In the beginning of a smouldering fire, emission of hydrogen in low concentration occurs. Therefore, hydrogen can be used to detect forest fires before open flames are visible and high temperatures are generated. We have developed a hydrogen sensor comprising of a metal/solid electrolyte/insulator/semiconductor (MEIS structure which allows an economical production. Due to the low energy consumption, an autarkic working unit in the forest was established. In this contribution, first experiments are shown demonstrating the possibility to detect forest fires at a very early stage using the hydrogen sensor.

  19. Electronuclear amplifiers with low-energy proton beams

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Shelaev, I.A.

    1998-01-01

    The use of proton accelerators with energy 200-300 MeV in subcritical electronuclear systems seems more preferable in comparison with more complicated and expensive machines with energy about 1 GeV, which are considered as favourite now. Such an approach allows one to build comparatively simple electronuclear plants in particular, for a safety and profitable incineration of plutonium from power plants and spells, in fact, a new strategy of electronuclear technology. Potentialities of the use of low-energy accelerators are illustrated by an electronuclear arrangements designed now in Dubna

  20. Some advances in medical applications of low energy accelerators

    Science.gov (United States)

    Valković, V.; Moschini, G.

    1991-05-01

    Medical applications of low energy accelerators include: the use of nuclear analytical methods and procedures for laboratory studies and routine measurements; material productions and modifications to meet special requirements; radioisotope productions and their applications in radiopharmaceuticals as well as in positron emission tomography; and radiotherapy with ions, based on improved understanding of the interaction of charged particles with living tissue. Some of the recent advances in these fields are critically summarized. The plan for an improved charged particle facility in a hospital environment dedicated to applications in biology and medicine is presented.

  1. Combining high-scale inflation with low-energy SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan [Basel Univ. (Switzerland). Dept. of Physics; Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut; Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Halter, Sebastian [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut

    2011-12-15

    We propose a general scenario for moduli stabilization where low-energy supersymmetry can be accommodated with a high scale of inflation. The key ingredient is that the stabilization of the modulus field during and after inflation is not associated with a single, common scale, but relies on two different mechanisms. We illustrate this general scenario in a simple example, where during inflation the modulus is stabilized with a large mass by a Kaehler potential coupling to the field which provides the inflationary vacuum energy via its F-term. After inflation, the modulus is stabilized, for instance, by a KKLT superpotential. (orig.)

  2. Status of the low energy neutron source at Indiana University

    International Nuclear Information System (INIS)

    Baxter, D.V.; Cameron, J.M.; Derenchuk, V.P.; Lavelle, C.M.; Leuschner, M.B.; Lone, M.A.; Meyer, H.O.; Rinckel, T.; Snow, W.M.

    2005-01-01

    The National Science Foundation has recently approved funding for LENS (the low energy neutron source) at Indiana University and construction of this facility has begun. LENS represents a new paradigm for economically introducing neutron scattering into a university or industrial setting. In this design, neutrons are produced in a long-pulse (1 ms) mode through (p,n) reactions on a water-cooled Be target and the target is tightly coupled to a cryogenic moderator with a water reflector. This design gives a facility suitable for materials research, the development of new neutron instrumentation, and the education of new neutron scientists

  3. Determination of the low energy spectra in the superstring theory

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1990-01-01

    There is one solution to the superstring theory in 10 dimensions (SO(32) ou E8xE8) but in a 4-dimensions space, there are plenty of solutions, so a classification is necessary. The author has used a formulation named fermionic, where the solution is easy to build and he has developed a program in terms of formal calculation (REDUCE). In a first time, this program verifies the constraints induced by the modular invariance and then reproduces the low energy spectra

  4. Introduction to the theory of low-energy electron diffraction

    International Nuclear Information System (INIS)

    Fingerland, A.; Tomasek, M.

    1975-01-01

    An elementary introduction to the basic principles of the theory of low-energy electron diffraction is presented. General scattering theory is used to classify the hitherto known approaches to the problem (optical potential and one-electron approximation; formal scattering theory: Born expansion and multiple scattering; translational symmetry: Ewald construction; classification of LEED theories by means of the T matrix; pseudokinematical theory for crystal with clean surface and with an adsorbed monomolecular layer; dynamical theory; inclusion of inelastic collisions; discussion of a simple example by means of the band-structure approach)

  5. Low-energy electron scattering from molecules, biomolecules and surfaces

    CERN Document Server

    Carsky, Petr

    2011-01-01

    Since the turn of the 21st century, the field of electron molecule collisions has undergone a renaissance. The importance of such collisions in applications from radiation chemistry to astrochemistry has flowered, and their role in industrial processes such as plasma technology and lighting are vital to the advancement of next generation devices. Furthermore, the development of the scanning tunneling microscope highlights the role of such collisions in the condensed phase, in surface processing, and in the development of nanotechnology.Low-Energy Electron Scattering from Molecules, Biomolecule

  6. Collisions between low-energy antihydrogen and atoms

    CERN Document Server

    Armour, E A G; Liu, Y; Martin, G D R

    2004-01-01

    Antihydrogen is currently the subject of great interest as cold H has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H system and give a progress report on the calculation that we are currently carrying out for this system.

  7. The low energy tagger for the KLOE-2 experiment

    International Nuclear Information System (INIS)

    Babusci, D.; Bini, C.; Ciambrone, P.; Corradi, G.; De Santis, A.; De Zorzi, G.; Di Domenico, A.; Fiore, S.; Gauzzi, P.; Iannarelli, M.; Miscetti, S.; Paglia, C.; Tagnani, D.; Turri, E.

    2010-01-01

    The KLOE experiment at the upgraded DAFNE e + e - collider in Frascati (KLOE-2) is going to start a new data taking at the beginning of 2010 with its detector upgraded with a tagging system for the identification of gamma-gamma interactions. The tagging stations for low-energy e + e - will consist in two calorimeters placed between the beam-pipe outer support structure and the inner wall of the KLOE drift chamber. This calorimeter will be made of LYSO crystals readout by Silicon Photomultipliers, to achieve an energy resolution better than 8% at 200 MeV.

  8. Low-energy gamma rays from Cygnus X-1

    International Nuclear Information System (INIS)

    Roques, J.P.; Mandrou, P.; Lebrun, F.; Paul, J.

    1985-08-01

    Cyg X-1 was observed by the CESR balloon borne telescope OPALE, in June 1976. The high-energy spectrum of the source, which was in its ''superlow state'', was seen to extend well beyond 1 MeV. In this paper, the observed low-energy γ-ray component of Cyg X-1 is compared with the predictions of recent models involving accretion onto a stellar black hole, and including a possible contribution from the pair-annihilation 511 keV γ-ray line

  9. Development of real-time low energy electron calorimeter

    International Nuclear Information System (INIS)

    Noriah Mod Ali; Smith, F.A.

    1999-01-01

    A low energy electron beam calorimeter with a thin film window has been fabricated to facilitate a reliable method of dose assessment for electron beam energies down to 200 keV. The system was designed to incorporate a data-logger in order that it could be used on the self-shielded 200 keV facility at MINT. In use, the calorimeter started logging temperature a short time before it passed under the beam and it continued taking data until well after the end of the irradiation. Data could be retrieved at any time after the calorimeter had emerged from the irradiator

  10. Implantation profile of low-energy positrons in solids

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Lynn, K.G.

    1990-01-01

    A simple form for an implantation profile of monoenergetic, low-energy (1--10 keV) positrons in solids is presented. Materials studied include aluminum, copper, molybdenum, palladium, and gold with atomic number ranging from 13 to 79. A simple set of parameters can describe the currently used Makhov profile in slow positron studies of solids. We provide curves and tables for the parameters that can be used to describe the implantation profiles of positrons in any material with atomic number in between 13 and 79

  11. Mott transition: Low-energy excitations and superconductivity

    International Nuclear Information System (INIS)

    Ioffe, L.B.; Larkin, A.I.

    1988-09-01

    It is possible that metal-dielectric transition does not result in changes of magnetic or crystallographic symmetry. In this case a fermionic spectrum is not changed at the transition, but additional low-energy excitations appear which can be described as a gauge field that has the same symmetry as an electromagnetic one. In the case of a non half-filled band gapless scalar Bose excitations also appear. Due to the presence of additional gauge field the physical conductivity is determined by the lowest conductivity of the Fermi or Bose subsystems. (author). 11 refs

  12. Low energy electron beams for industrial and environmental applications

    CERN Document Server

    Skarda, Vlad

    2017-01-01

    EuCARD-2 Workshop, 8-9 December 2016, Warsaw, Poland. Organizers: Science and Technology Facilities Council, UK CERN - The European Organization for Nuclear Research, Switzerland, Institute of Nuclear Chemistry and Technology, Poland, Fraunhofer Institute for Electron Beam and Plasma Technology, Germany, Warsaw University of Technology, Poland. An article presents short information about EuCARD-2 Workshop “Low energy electron beams for industrial and environmental applications”, which was held in December 2016 in Warsaw. Objectives, main topics and expected output of meeting are described. List of organizers is included.

  13. Development of a low energy micro sheet forming machine

    Science.gov (United States)

    Razali, A. R.; Ann, C. T.; Shariff, H. M.; Kasim, N. I.; Musa, M. A.; Ahmad, A. F.

    2017-10-01

    It is expected that with the miniaturization of materials being processed, energy consumption is also being `miniaturized' proportionally. The focus of this study was to design a low energy micro-sheet-forming machine for thin sheet metal application and fabricate a low direct current powered micro-sheet-forming machine. A prototype of low energy system for a micro-sheet-forming machine which includes mechanical and electronic elements was developed. The machine was tested for its performance in terms of natural frequency, punching forces, punching speed and capability, energy consumption (single punch and frequency-time based). Based on the experiments, the machine can do 600 stroke per minute and the process is unaffected by the machine's natural frequency. It was also found that sub-Joule of power was required for a single stroke of punching/blanking process. Up to 100micron thick carbon steel shim was successfully tested and punched. It concludes that low power forming machine is feasible to be developed and be used to replace high powered machineries to form micro-products/parts.

  14. Low energy recoil detection with a spherical proportional counter

    Science.gov (United States)

    Savvidis, I.; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2018-01-01

    We present results for the detection of low energy nuclear recoils in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An 241Am-9Be fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the keV energy region was measured by observing the 5.9 keV line of a 55Fe X-ray source, with energy resolution of 10% (σ). The toolkit GEANT4 was used to simulate the irradiation of the detector by an 241Am-9Be source, while SRIM was used to calculate the Ionization Quenching Factor (IQF), the simulation results are compared with the measurements. The potential of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searches (via coherent elastic scattering).

  15. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1993-01-01

    This report summarizes the accomplishments of the project ''Studies of nuclear reactions at very low energies''. This project was undertaken in 1987 and completed in 1993. All but one of the major objectives of this study have been accomplished. Specifically the authors have completed their investigation of the (p,γ) on light nuclei, a study of the Oppenheimer-Phillips effect, a measurements of the astrophysically interesting reaction D(α,γ) 6 Li at low energies and an extension of the reaction D(d,γ) 4 He to lower energies than previously observed. Preliminary investigation of te reaction 7 Li( 3 He,p) 9 Be was begun and is continuing under a separate DOE grant. In addition to these tasks, they have completed some very interesting projects which were not included in the original proposal. These include a study of the (d,γ) reactions on 6 Li, 7 Li and 10 B and an investigation of the possibility of observing terrestrial antineutrinos from the beta decay chains of U and Th as a diagnostic of terrestrial heat flow

  16. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

    Directory of Open Access Journals (Sweden)

    Tanya M. S. David

    2014-01-01

    Full Text Available Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO level of −3.33 eV based on optical energy gap. The polymer was synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.

  17. rf quadrupole linac: a new low-energy accelerator

    International Nuclear Information System (INIS)

    Hamm, R.W.; Crandall, K.R.; Fuller, C.W.

    1980-01-01

    A new concept in low-energy particle accelerators, the radio-frequency quadrupole (RFQ) linac, is currently being developed at the Los Alamos National Scientific Laboratory. In this new linear accelerating structure both the focusing and accelerating forces are produced by the rf fields. It can accept a high-current, low-velocity dc ion beam and bunch it with a high capture efficiency. The performance of this structure as a low-energy linear accelerator has been verified with the successful construction of a proton RFQ linac. This test structure has accelerated 38 mA of protons from 100 keV to 640 keV in 1.1 meters with a capture efficiency greater than 80%. In this paper a general description of the RFQ linac and an outline of the basic RFQ linac design procedure are presented in addition to the experimental results from the test accelerator. Finally, several applications of this new accelerator are discussed

  18. Formation of a high intensity low energy positron string

    Science.gov (United States)

    Donets, E. D.; Donets, E. E.; Syresin, E. M.; Itahashi, T.; Dubinov, A. E.

    2004-05-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5×109 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production.

  19. Formation of a high intensity low energy positron string

    International Nuclear Information System (INIS)

    Donets, E.D.; Donets, E.E.; Syresin, E.M.; Itahashi, T.; Dubinov, A.E.

    2004-01-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5x10 9 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production

  20. Low-energy control of electrical turbulence in the heart

    Science.gov (United States)

    Luther, Stefan; Fenton, Flavio H.; Kornreich, Bruce G.; Squires, Amgad; Bittihn, Philip; Hornung, Daniel; Zabel, Markus; Flanders, James; Gladuli, Andrea; Campoy, Luis; Cherry, Elizabeth M.; Luther, Gisa; Hasenfuss, Gerd; Krinsky, Valentin I.; Pumir, Alain; Gilmour, Robert F.; Bodenschatz, Eberhard

    2011-07-01

    Controlling the complex spatio-temporal dynamics underlying life-threatening cardiac arrhythmias such as fibrillation is extremely difficult, because of the nonlinear interaction of excitation waves in a heterogeneous anatomical substrate. In the absence of a better strategy, strong, globally resetting electrical shocks remain the only reliable treatment for cardiac fibrillation. Here we establish the relationship between the response of the tissue to an electric field and the spatial distribution of heterogeneities in the scale-free coronary vascular structure. We show that in response to a pulsed electric field, E, these heterogeneities serve as nucleation sites for the generation of intramural electrical waves with a source density ρ(E) and a characteristic time, τ, for tissue depolarization that obeys the power law τ~Eα. These intramural wave sources permit targeting of electrical turbulence near the cores of the vortices of electrical activity that drive complex fibrillatory dynamics. We show in vitro that simultaneous and direct access to multiple vortex cores results in rapid synchronization of cardiac tissue and therefore, efficient termination of fibrillation. Using this control strategy, we demonstrate low-energy termination of fibrillation in vivo. Our results give new insights into the mechanisms and dynamics underlying the control of spatio-temporal chaos in heterogeneous excitable media and provide new research perspectives towards alternative, life-saving low-energy defibrillation techniques.

  1. Do paralympic track and field athletes have low energy availability?

    Directory of Open Access Journals (Sweden)

    Daniel Paduan Joaquim

    2018-03-01

    Full Text Available One of the greatest challenges when working with athletes is to achieve the energy demands for physiological processes and exercise expenditure. The aim of this study was to assess the energy availability (EA of Paralympic track and field athletes (sprinters. Seventeen athletes (9 male and 8 female with visual impairment (VI, n=10, cerebral palsy (CP, n=4 and limb deficiency (LD, n=3 were assessed for energy intake (EI (4-day food photographic record, energy expenditure with exercise (EEex (motion sensor, and body composition (skinfolds method. Energy availability was estimated using the equation: EA = (EIkcal - EEexkcal / fat-free mass (FFM / day, and values ≤ 30kcal/kgFFM/day were considered as low energy availability (LEA. EEex varied from 130 to 477kcal/h and athletes trained in average for 3.2 hours per day. Mean EA for VI, LD and CP were 36 (2.19, 37 (1.90 and 38 (3.38 kcal/kgFFM/day, respectively. Most (82.3% participants presented EA below ≥ 45kcal/kgFFM/day, throughout the days, which are the recommended values for athletes without disability. Athletes should be encouraged to consume adequate EA to avoid consequences related to low energy availability. There is need of further research to identify cut-off values adequate for this population.

  2. Low-energy-state dynamics of entanglement for spin systems

    International Nuclear Information System (INIS)

    Jafari, R.

    2010-01-01

    We develop the ideas of the quantum renormalization group and quantum information by exploring the low-energy-state dynamics of entanglement resources of a system close to its quantum critical point. We demonstrate that low-energy-state dynamical quantities of one-dimensional magnetic systems can show a quantum phase transition point and show scaling behavior in the vicinity of the transition point. To present our idea, we study the evolution of two spin entanglements in the one-dimensional Ising model in the transverse field. The system is initialized as the so-called thermal ground state of the pure Ising model. We investigate the evolution of the generation of entanglement with increasing magnetic field. We obtain that the derivative of the time at which the entanglement reaches its maximum with respect to the transverse field diverges at the critical point and its scaling behaviors versus the size of the system are the same as the static ground-state entanglement of the system.

  3. Low-Energy Electron Scattering by Sugarcane Lignocellulosic Biomass Molecules

    Science.gov (United States)

    Oliveira, Eliane; Sanchez, Sergio; Bettega, Marcio; Lima, Marco; Varella, Marcio

    2012-06-01

    The use of second generation (SG) bioethanol instead of fossil fuels could be a good strategy to reduce greenhouse gas emissions. However, the efficient production of SG bioethanol has being a challenge to researchers around the world. The main barrier one must overcome is the pretreatment, a very important step in SG bioethanol aimed at breaking down the biomass and facilitates the extraction of sugars from the biomass. Plasma-based treatment, which can generate reactive species, could be an interesting possibility since involves low-cost atmospheric-pressure plasma. In order to offer theoretical support to this technique, the interaction of low-energy electrons from the plasma with biomass is investigated. This study was motived by several works developed by Sanche et al., in which they understood that DNA damage arises from dissociative electron attachment, a mechanism in which electrons are resonantly trapped by DNA subunits. We will present elastic cross sections for low-energy electron scattering by sugarcane biomass molecules, obtained with the Schwinger multichannel method. Our calculations indicate the formation of π* shape resonances in the lignin subunits, while a series of broad and overlapping σ* resonances are found in cellulose and hemicellulose subunits. The presence of π* and σ* resonances could give rise to direct and indirect dissociation pathways in biomass. Then, theoretical resonance energies can be useful to guide the plasma-based pretreatment to break down specific linkages of interest in biomass.

  4. Low energy description of quantum gravity and complementarity

    International Nuclear Information System (INIS)

    Nomura, Yasunori; Varela, Jaime; Weinberg, Sean J.

    2014-01-01

    We consider a framework in which low energy dynamics of quantum gravity is described preserving locality, and yet taking into account the effects that are not captured by the naive global spacetime picture, e.g. those associated with black hole complementarity. Our framework employs a “special relativistic” description of gravity; specifically, gravity is treated as a force measured by the observer tied to the coordinate system associated with a freely falling local Lorentz frame. We identify, in simple cases, regions of spacetime in which low energy local descriptions are applicable as viewed from the freely falling frame; in particular, we identify a surface called the gravitational observer horizon on which the local proper acceleration measured in the observer's coordinates becomes the cutoff (string) scale. This allows for separating between the “low-energy” local physics and “trans-Planckian” intrinsically quantum gravitational (stringy) physics, and allows for developing physical pictures of the origins of various effects. We explore the structure of the Hilbert space in which the proposed scheme is realized in a simple manner, and classify its elements according to certain horizons they possess. We also discuss implications of our framework on the firewall problem. We conjecture that the complementarity picture may persist due to properties of trans-Planckian physics.

  5. Low energy nanoemulsification to design veterinary controlled drug delivery devices

    Directory of Open Access Journals (Sweden)

    Thierry F Vandamme

    2010-10-01

    Full Text Available Thierry F Vandamme, Nicolas Anton, University of Strasbourg, Faculty of Pharmacy, Illkirch Cedex, France; UMR CNRS 7199, Laboratoire de Conception et Application de Molécules Bioactives, équipe de Pharmacie Biogalénique, Illkirch Cedex, France,  This work is selected as Controlled Release Society Outstanding Veterinary Paper Award 2010Abstract: The unique properties of nanomaterials related to structural stability and quantum-scale reactive properties open up a world of possibilities that could be exploited to design and to target drug delivery or create truly microscale biological sensors for veterinary applications. We developed cost-saving and solvent-free nanoemulsions. Formulated with a low-energy method, these nanoemulsions can find application in the delivery of controlled amounts of drugs into the beverage of breeding animals (such as poultry, cattle, pigs or be used for the controlled release of injectable poorly water-soluble drugs.Keywords: nanoemulsion, nanomedicine, low-energy emulsification, veterinary, ketoprofen, sulfamethazine

  6. The low energy detector of Simbol-X

    Science.gov (United States)

    Lechner, P.; Andricek, L.; Briel, U.; Hasinger, G.; Heinzinger, K.; Herrmann, S.; Huber, H.; Kendziorra, E.; Lauf, T.; Lutz, G.; Richter, R.; Santangelo, A.; Schaller, G.; Schnecke, M.; Schopper, F.; Segneri, G.; Strüder, L.; Treis, J.

    2008-07-01

    Simbol-X is a French-Italian-German hard energy X-ray mission with a projected launch in 2014. Being sensitive in the energy range from 500 eV to 80 keV it will cover the sensitivity gap beyond the energy interval of today's telescopes XMM-Newton and Chandra. Simbol-X will use an imaging telescope of nested Wolter-I mirrors. To provide a focal length of 20 m it will be the first mission of two independent mirror and detector spacecrafts in autonomous formation flight. The detector spacecraft's payload is composed of an imaging silicon low energy detector in front of a pixelated cadmium-telluride hard energy detector. Both have a sensitive area of 8 × 8 cm2 to cover a 12 arcmin field of view and a pixel size of 625 × 625 μm2 adapted to the telescope's resolution of 20 arcsec. The additional LED specifications are: high energy resolution, high quantum efficiency, fast readout and optional window mode, monolithic device with 100 % fill factor and suspension mounting, and operation at warm temperature. To match these requirements the low energy detector is composed of 'active macro pixels', combining the large, scalable area of a Silicon Drift Detector and the low-noise, on-demand readout of an integrated DEPFET amplifier. Flight representative prototypes have been processed at the MPI semiconductor laboratory, and the prototype's measured performance demonstrates the technology readiness.

  7. Low energy electron point source microscopy: beyond imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Andre; Goelzhaeuser, Armin [Physics of Supramolecular Systems and Surfaces, University of Bielefeld, Postfach 100131, 33501 Bielefeld (Germany)

    2010-09-01

    Low energy electron point source (LEEPS) microscopy has the capability to record in-line holograms at very high magnifications with a fairly simple set-up. After the holograms are numerically reconstructed, structural features with the size of about 2 nm can be resolved. The achievement of an even higher resolution has been predicted. However, a number of obstacles are known to impede the realization of this goal, for example the presence of electric fields around the imaged object, electrostatic charging or radiation induced processes. This topical review gives an overview of the achievements as well as the difficulties in the efforts to shift the resolution limit of LEEPS microscopy towards the atomic level. A special emphasis is laid on the high sensitivity of low energy electrons to electrical fields, which limits the structural determination of the imaged objects. On the other hand, the investigation of the electrical field around objects of known structure is very useful for other tasks and LEEPS microscopy can be extended beyond the task of imaging. The determination of the electrical resistance of individual nanowires can be achieved by a proper analysis of the corresponding LEEPS micrographs. This conductivity imaging may be a very useful application for LEEPS microscopes. (topical review)

  8. Homestake result, sterile neutrinos, and low energy solar neutrino experiments

    Science.gov (United States)

    de Holanda, P. C.; Smirnov, A. Yu.

    2004-06-01

    The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E=(0.5 5) MeV thus suppressing the Be, or/and pep, CNO, as well as B electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

  9. New Mechanism of Low Energy Nuclear Reactions Using Superlow

    Science.gov (United States)

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

    2006-03-01

    We proposed a new mechanism of LENR (low energy nuclear reactions) cooperative processes in the whole system - nuclei+atoms+condensed matter can occur at smaller threshold than the corresponding ones assoiciated with free constituents. The cooperative processes can be induced and enhanced by (``superlow energy'') external fields. The excess heat is the emission of internal energy, and transmutations from LENR are the result of redistribution of the internal energy of the whole system. A review of possible stimulation mechanisms of LENR is presented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the known fundamental physical laws: The universal resonance synchronization principle, and based on it, different enhancement mechanisms of reaction rates are responsible for these processes. The excitation and ionization of atoms may play the role of a trigger for LENR. F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0511092 v1 30 Nov 2005. F.A. Gareev, In: FPB-98, Novosibirsk, June 1998, p.92; F.A.Gareev, G.F. Gareeva, in: Novosibirsk, July 2000, p.161. F.A. Gareev, I.E. Zhidkova and Yu.L. Ratis, Preprint JINR P4-2004-68, Dubna, 2004. F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0505021 9 May 2005.

  10. Calculation and Measurement of Low-Energy Radiative Moller Scattering

    Science.gov (United States)

    Epstein, Charles; DarkLight Collaboration

    2017-09-01

    A number of current nuclear physics experiments have come to rely on precise knowledge of electron-electron (Moller) and positron-electron (Bhabha) scattering. Some of these experiments, having lepton beams on targets containing atomic electrons, use these purely-QED processes as normalization. In other scenarios, with electron beams at low energy and very high intensity, Moller scattering and radiative Moller scattering have such enormous cross-sections that the backgrounds they produce must be understood. In this low-energy regime, the electron mass is also not negligible in the calculation of the cross section. This is important, for example, in the DarkLight experiment (100 MeV). As a result, we have developed a new event generator for the radiative Moller and Bhabha processes, with new calculations that keep all terms of the electron mass. The MIT High Voltage Research Laboratory provides us a unique opportunity to study this process experimentally and compare it with our work, at a low beam energy of 2.5 MeV where the effects of the electron mass are significant. We are preparing a dedicated apparatus consisting of a magnetic spectrometer in order to directly measure this process. An overview of the calculation and the status of the experiment will be presented.

  11. Low energy probes of PeV scale sfermions

    Energy Technology Data Exchange (ETDEWEB)

    Altmannshofer, Wolfgang; Harnik, Roni; Zupan, Jure

    2013-11-27

    We derive bounds on squark and slepton masses in mini-split supersymmetry scenario using low energy experiments. In this setup gauginos are at the TeV scale, while sfermions are heavier by a loop factor. We cover the most sensitive low energy probes including electric dipole moments (EDMs), meson oscillations and charged lepton flavor violation (LFV) transitions. A leading log resummation of the large logs of gluino to sfermion mass ratio is performed. A sensitivity to PeV squark masses is obtained at present from kaon mixing measurements. A number of observables, including neutron EDMs, mu->e transitions and charmed meson mixing, will start probing sfermion masses in the 100 TeV-1000 TeV range with the projected improvements in the experimental sensitivities. We also discuss the implications of our results for a variety of models that address the flavor hierarchy of quarks and leptons. We find that EDM searches will be a robust probe of models in which fermion masses are generated radiatively, while LFV searches remain sensitive to simple-texture based flavor models.

  12. Dynamical black holes in low-energy string theory

    Energy Technology Data Exchange (ETDEWEB)

    Aniceto, Pedro [Departamento de Matemática, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Rocha, Jorge V. [Departament de Física Quàntica i Astrofísica, Institut de Ciències del Cosmos (ICCUB),Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain)

    2017-05-08

    We investigate time-dependent spherically symmetric solutions of the four-dimensional Einstein-Maxwell-axion-dilaton system, with the dilaton coupling that occurs in low-energy effective heterotic string theory. A class of dilaton-electrovacuum radiating solutions with a trivial axion, previously found by Güven and Yörük, is re-derived in a simpler manner and its causal structure is clarified. It is shown that such dynamical spacetimes featuring apparent horizons do not possess a regular light-like past null infinity or future null infinity, depending on whether they are radiating or accreting. These solutions are then extended in two ways. First we consider a Vaidya-like generalisation, which introduces a null dust source. Such spacetimes are used to test the status of cosmic censorship in the context of low-energy string theory. We prove that — within this family of solutions — regular black holes cannot evolve into naked singularities by accreting null dust, unless standard energy conditions are violated. Secondly, we employ S-duality to derive new time-dependent dyon solutions with a nontrivial axion turned on. Although they share the same causal structure as their Einstein-Maxwell-dilaton counterparts, these solutions possess both electric and magnetic charges.

  13. Low energy methods of molecular laser isotope separation

    International Nuclear Information System (INIS)

    Makarov, G N

    2015-01-01

    Of the many proposals to date for laser-assisted isotope separation methods, isotope-selective infrared (IR) multiphoton dissociation (MPD) of molecules has been the most fully developed. This concept served as the basis for the development and operation of the carbon isotope separation facility in Kaliningrad, Russia. The extension of this method to heavy elements, including uranium, is hindered by, among other factors, the high power consumption and the lack of high-efficiency high-power laser systems. In this connection, research and development covering low energy methods for the laser separation of isotopes (including those of heavy atoms) is currently in high demand. This paper reviews approaches to the realization of IR-laser-induced isotope-selective processes, some of which are potentially the basis on which low-energy methods for molecular laser isotope separation can be developed. The basic physics and chemistry, application potential, and strengths and weaknesses of these approaches are discussed. Potentially promising alternatives to the title methods are examined. (reviews of topical problems)

  14. Quantification of the validity of simulations based on Geant4 and FLUKA for photo-nuclear interactions in the high energy range

    Science.gov (United States)

    Quintieri, Lina; Pia, Maria Grazia; Augelli, Mauro; Saracco, Paolo; Capogni, Marco; Guarnieri, Guido

    2017-09-01

    Photo-nuclear interactions are relevant in many research fields of both fundamental and applied physics and, for this reason, accurate Monte Carlo simulations of photo-nuclear interactions can provide a valuable and indispensable support in a wide range of applications (i.e from the optimisation of photo-neutron source target to the dosimetric estimation in high energy accelerator, etc). Unfortunately, few experimental photo-nuclear data are available above 100 MeV, so that, in the high energy range (from hundreds of MeV up to GeV scale), the code predictions are based on physical models. The aim of this work is to compare the predictions of relevant observables involving photon-nuclear interaction modelling, obtained with GEANT4 and FLUKA, to experimental data (if available), in order to assess the code estimation reliability, over a wide energy range. In particular, the comparison of the estimated photo-neutron yields and energy spectra with the experimental results of the n@BTF experiment (carried out at the Beam Test Facility of DaΦne collider, in Frascati, Italy) is here reported and discussed. Moreover, the preliminary results of the comparison of the cross sections used in the codes with the"evaluated' data recommended by the IAEA are also presented for some selected cases (W, Pb, Zn).

  15. Assessing risk from low energy radionuclide aerosol dispersal

    International Nuclear Information System (INIS)

    Waller, Edward; Perera, Sharman; Erhardt, Lorne; Cousins, Tom; Desrosiers, Marc

    2008-01-01

    Full text: When considering the potential dispersal of radionuclides into the environment, there are two broad classifications: explosive and non-explosive dispersal. An explosive dispersal relies on a violent and sudden release of energy, which may disrupt or vapourised any source containment. As such, the explosion provides the energy to both convert the source into a dispersable physical form and provides initial kinetic energy to transport the source away from the initiation point. This would be the case for sources of radiation in proximity to a steam or chemical explosion of high energy density. A low energy dispersal, on the other hand, may involve a lower energy initiator event (such as a fire or water spray) that transports particles into the near release zone, to be spread via wind or mechanical fields. For this type of dispersion to take place, the source must be in physical form ready for dispersal. In broad terms, this suggests either an ab initio powder form, or soluble/insoluble particulate form in a liquid matrix. This may be the case for radioactive material released from pressurized piping systems, material released through ventilation systems, or deliberate dispersals. To study aerosol dispersion of radionuclides and risk from low energy density initiators, there are a number of important parameters to consider. For example, particle size distribution, physicochemical form, atmospheric effects, charge effects, coagulation and agglomeration. At the University of Ontario Institute of Technology (UOIT) a unique small scale aerosol test chamber has been developed to study the low energy dispersal properties of a number of radioactive source simulant. Principle emphasis has been given to salts (CsCl and CoCl 2 ) and oxides (SrTiO 3 , CeO 2 and EuO 2 ). A planetary ball mill has been utilized to reduce particle size distributions when required. Particle sizing has been performed using Malvern Spraytec spray particle analyzers, cascade impactors, and

  16. Low energy, high power injection in JT-60 NBI

    International Nuclear Information System (INIS)

    Mizuno, Makoto; Dairaku, Masayuki; Horiike, Hiroshi

    1988-05-01

    JT-60 neutral beam injector (JT-60 NBI) is designed to inject 20 MW neutral hydrogen beam at energies of 70 ∼ 100 keV and the injection power decreases significantly at low energies (∼40 keV). For the extention of operation region aiming at the low density plasma heating and achieving H-mode by plasma periphery heating, increment of the injection power at low beam energies was required. The single-stage acceleration system was investigated in advance at the Prototype Injector Unit. From this result, the total injection power of 17 MW at 40 keV, 48 A per source was expected at the JT-60 NBI. This system was adopted in the JT-60 NBI from June, 1987 to July, 1987 and 17.6 MW neutral beam injection power was achieved. In the NB heating experiment, the H-mode transition phenomena was observed in JT-60 plasma. (author)

  17. The nuclear structure and low-energy reactions (NSLER) collaboration

    International Nuclear Information System (INIS)

    Dean, D J

    2006-01-01

    The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible

  18. Safety in design and operation of low energy particle accelerators

    International Nuclear Information System (INIS)

    Badawy, I.

    1991-01-01

    This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

  19. Development of a low energy neutral analyzer (LENA). Final report

    International Nuclear Information System (INIS)

    Curtis, C.C.; Fan, C.Y.; Hsieh, K.C.; McCullen, J.D.

    1986-05-01

    A low energy neutral particle analyzer (LENA) has been developed at the University of Arizona to detect particles originating in the edge plasma of fusion reactors. LENA was designed to perform energy analysis and measure flux levels of neutrals having energies between 5 and 50 eV (with possible extension to 500 eV neutrals), and do this with 1 to 10 ms time resolution. The instrument uses hot filaments to produce a 10 mA diffusion electron beam which ionizes incoming neutrals in a nearly field free region so that their velocity distribution is nearly undisturbed. The resultant ions are energy analyzed in a hyperbolic electrostatic analyzer, and detected by an MCP detector. LENA has been installed and operated on the ALCATOR C tokamak at the MIT Plasma Fusion Center. Results to date are discussed. At present, the LENA exhibits excessive sensitivity to the extremely high ultraviolet photon flux emanating from the plasma. Measures to correct this are suggested

  20. Radiation from silver films bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Chung, M.S.; Callcott, T.A.; Kretschmann, E.; Arakawa, E.T.

    1980-01-01

    Emission spectra from Ag films irradiated by low energy electrons (20-1500 eV) have been measured, and the results compared with theory. For relatively smooth films, two peaks in the spectra are resolved. One at 3.73 eV, the volume plasmon energy, is attributed to transition radiation and/or bremsstrahlung. The second, at about 3.60 eV, is very sensitive to surface roughness in both position and magnitude and is produced by roughness-coupled radiation from surface plasmons. For rough films, the roughness-coupled radiation dominates the emission. In addition to spectral shapes, the polarization of the radiation and its intensity as a function of electron energy were measured. The experimental results are compared with new calculations of roughness-coupled emission which account for most of our observations. They indicate that high wavevector roughness components play the dominant role in the emission process. (orig.)

  1. Elastic scattering of low-energy electrons with Sr atoms

    International Nuclear Information System (INIS)

    Yuan, J.; Zhang, Z.; Wan, H.

    1990-01-01

    Static-exchange, plus correlation-polarization-potential calculations are performed for elastic low-energy electron scattering from Sr atoms while paying attention to the low-lying shape resonances. The correlation potential is calculated both with and without a scaling factor. A 2 D-shape resonance is produced at 1.0 eV with a parameter-free, and at 1.25 eV with a scaled, correlation potential. No 2 P-shape resonances are predicted, but evidence to support the existence of a stable negative ion Sr - in the 5s 2 5p electron configuration is given from the viewpoint of electron scattering. The bound energy of the extra electron in the negative ion is estimated by transforming the phase shift of the corresponding partial wave into the polarization quantum-defect number and extrapolating the number from positive to negative energies

  2. Confab - Systematic generation of diverse low-energy conformers

    Directory of Open Access Journals (Sweden)

    O'Boyle Noel M

    2011-03-01

    Full Text Available Abstract Background Many computational chemistry analyses require the generation of conformers, either on-the-fly, or in advance. We present Confab, an open source command-line application for the systematic generation of low-energy conformers according to a diversity criterion. Results Confab generates conformations using the 'torsion driving approach' which involves iterating systematically through a set of allowed torsion angles for each rotatable bond. Energy is assessed using the MMFF94 forcefield. Diversity is measured using the heavy-atom root-mean-square deviation (RMSD relative to conformers already stored. We investigated the recovery of crystal structures for a dataset of 1000 ligands from the Protein Data Bank with fewer than 1 million conformations. Confab can recover 97% of the molecules to within 1.5 Å at a diversity level of 1.5 Å and an energy cutoff of 50 kcal/mol. Conclusions Confab is available from http://confab.googlecode.com.

  3. Automorphic properties of low energy string amplitudes in various dimensions

    International Nuclear Information System (INIS)

    Green, Michael B.; Russo, Jorge G.; Vanhove, Pierre

    2010-01-01

    This paper explores the moduli-dependent coefficients of higher-derivative interactions that appear in the low-energy expansion of the four-supergraviton amplitude of maximally supersymmetric string theory compactified on a d torus. These automorphic functions are determined for terms up to order ∂ 6 R 4 and various values of d by imposing a variety of consistency conditions. They satisfy Laplace eigenvalue equations with or without source terms, whose solutions are given in terms of Eisenstein series, or more general automorphic functions, for certain parabolic subgroups of the relevant U-duality groups. The ultraviolet divergences of the corresponding supergravity field theory limits are encoded in various logarithms, although the string theory expressions are finite. This analysis includes intriguing representations of SL(d) and SO(d,d) Eisenstein series in terms of toroidally compactified one and two-loop string and supergravity amplitudes.

  4. A New Instrument Design for Imaging Low Energy Neutral Atoms

    Science.gov (United States)

    Keller, John W.; Collier, Michael R.; Chornay, Dennis; Rozmarynowski, Paul; Getty, Stephanie; Cooper, John F.; Smith, Billy

    2007-01-01

    The MidSTAR-2 satellite, to be built at the US Naval Academy as a follow-on to the successful MidSTAR-1 satellite (http://web.ew.usna.edu/midstar/), will launch in 2011 and carry three Goddard Space Flight Center (GSFC) experiments developed under Goddard's Internal Research and Development (IRAD) program. One of these GSFC instruments, the Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons (MINI-ME) builds on the heritage of the Goddard-developed Low-Energy Neutral Atom (LENA) imager launched on the IMAGE spacecraft in 2000. MINI-ME features a Venetian-blind conversion surface assembly that improves both light rejection and conversion efficiency in a smaller and lighter package than LENA making this an highly effective instrument for viewing solar wind charge exchange with terrestrial and planetary exospheres. We will describe the MINI-ME prototyping effort and its science targets.

  5. Simulation of a low energy beam transport line

    International Nuclear Information System (INIS)

    Yang Yao; Liu Zhanwen; Zhang Wenhui; Ma Hongyi; Zhang Xuezhen; Zhao Hongwei; Yao Ze'en

    2012-01-01

    A 2.45 GHz electron cyclotron resonance intense proton source and a low energy beam transport line with dual-Glaser lens were designed and fabricated by Institute of Modern Physics for a compact pulsed hadron source at Tsinghua. The intense proton beams extracted from the ion source are transported through the transport line to match the downstream radio frequency quadrupole accelerator. Particle-in-cell code BEAMPATH was used to carry out the beam transport simulations and optimize the magnetic field structures of the transport line. Emittance growth due to space charge and spherical aberrations of the Glaser lens were studied in both theory and simulation. The results show that narrow beam has smaller aberrations and better beam quality through the transport line. To better match the radio frequency quadrupole accelerator, a shorter transport line is desired with sufficient space charge neutralization. (authors)

  6. A simulation of low energy channeling of protons in silicon

    International Nuclear Information System (INIS)

    Sabin, J.R.

    1994-01-01

    The authors present early results from the CHANNEL code, which simulates the passage of ionized projectiles through bulk solids. CHANNEL solves the classical equations of motion for the projectile using the force obtained from the gradient of the quantum mechanically derived coulombic potential of the solid (determined via a full potential augmented plane wave FLAPW calculation on the bulk) and a quantum mechanical energy dissipation term, the stopping power, as determined from the local electron density, using the method of Echenique, Nieminen, and Ritchie. The code then generates the trajectory of the ionic projectile for a given initial velocity and a given incident position on the unit cell face. For each incident projectile velocity, the authors generate trajectories for incidence distributed over the channel face. The distribution of ranges generates an implantation profile. In this paper, they report ion (proton) implantation profiles for low energy protons with initial velocity along the (100) and (110) channel directions of diamond structured Silicon

  7. The quasi deuteron model for low energy pion absorption

    International Nuclear Information System (INIS)

    Gouweloos, M.

    1986-01-01

    In this thesis pion absorption in complex nuclei is studied in the quasi-deuteron model in which the pion is absorbed on a nucleon pair in the nucleus. The mechanism is studied in the low-energy domain since then the in-medium (pi→NN) operator turns out to be of simple character. In Ch. 2 and 3 this operator is constructed and analytical expressions are derived for (pi,NN) distributions in a plane wave impulse approximation for nuclei. The results turn out to be very useful for developing insight in the possibilities inherent in the QDM and the interpretation of the results in later chapters. Ch. 4 to 6 are devoted to the more realistic distorted wave calculations. In Ch. 4 the formal framework is presented and the calculational details are discussed. Ch.5 and 6 contain the comparison to stopped pion and in-flight data respectively. In Ch. 7 the main results are summarized. (Auth.)

  8. Elastic positron-cadmium scattering at low energies

    International Nuclear Information System (INIS)

    Bromley, M. W. J.; Mitroy, J.

    2010-01-01

    The elastic and annihilation cross sections for positron-cadmium scattering are reported up to the positronium-formation threshold (at 2.2 eV). The low-energy phase shifts for the elastic scattering of positrons from cadmium were derived from the bound and pseudostate energies of a very large basis configuration-interaction calculation of the e + -Cd system. The s-wave binding energy is estimated to be 126±42 meV, with a scattering length of A scat =(14.2±2.1)a 0 , while the threshold annihilation parameter, Z eff , was 93.9±26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Z eff of 91±17 at a collision energy of about 490±50 meV.

  9. Measurements of sputtering yields for low-energy plasma ions

    International Nuclear Information System (INIS)

    Nishi, M.; Yamada, M.; Suckewer, S.; Rosengaus, E.

    1979-04-01

    Sputtering yields of various wall/limiter materials of fusion devices have been extensively measured in the relevant plasma environment for low-energy light ions (E 14 cm -3 and electron temperature up to 10eV. Target materials used were C (graphite), Ti, Mo, Ta, W, and Fe (stainless steel). In order to study the dependence of the sputtering yields on the incident energy of ions, the target samples were held at negative bias voltage up to 300V. The sputtering yields were determined by a weight-loss method and by spectral line intensity measurements. The data obtained in the present experiment agree well with those previously obtained at the higher energies (E greater than or equal to 200eV) by other authors using different schemes; the present data also extend to substantially lower energies (E approx. > 30eV) than hitherto

  10. Degradation of carrageenan by low energy electron accelerator

    International Nuclear Information System (INIS)

    Relleve, L.; Aranilla, C.; Abad, L.; Dela Rosa, A.; Nagasawa, Naotsugu; Yagi, Toshiaki; Kume, Tamikazu; Yoshii, Fumio

    2004-01-01

    Degradation of κ-carrageenan using vessel-type low energy electron accelerator was investigated. Carrageenan with different molecular weights were obtained from irradiation of high molecular weight (HMW) and low molecular weight (LMW) κ-carrageenan. Other results presented were obtained from degradation studies of carrageenan by gamma rays. The decrease in molecular weight was accompanied by partial desulfation. From comparison of radiation degradation yield (Gd), it was found that the susceptibility to radiation of the three types of carrageenans in aqueous/gel forms follows the order of λ->ι->>κ- and could have been influenced by their conformational state. κ-carrageenan with molecular weight of ca. 10,000 showed strong growth promotion effect for potato in tissue culture. (author)

  11. The low-energy frontier of particle physics

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2010-02-01

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  12. A theory of low energy π-3He elastic scattering

    International Nuclear Information System (INIS)

    Geffen, F.M.M. van.

    1991-01-01

    The main aim of this work is the construction of a first-order optical potential for the scattering of pions by 3 He at low energy with as few approximations as possible. In particular the Fermi motion is treated extremely carefully by using microscopic 3 He wave functions and by performing the complete Fermi-integral. Differential cross-sections and analyzing powers have been calculated. In a detailed comparison between the first-order optical with one which results from using the semi-factored approximation, it became clear that the latter has the following shortcomings: 1. the dependence of the subenergy on the pion-nucleus scattering angle, and 2. the independence of this energy on the relative motion of the spectator nucleons. (author). 101 refs.; 15 figs.; 3 tabs

  13. Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

    Science.gov (United States)

    Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

    2017-07-28

    We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

  14. Medipix 2 detector applied to low energy electron microscopy

    International Nuclear Information System (INIS)

    Gastel, R. van; Sikharulidze, I.; Schramm, S.; Abrahams, J.P.; Poelsema, B.; Tromp, R.M.; Molen, S.J. van der

    2009-01-01

    Low energy electron microscopy (LEEM) and photo-emission electron microscopy (PEEM) traditionally use microchannel plates (MCPs), a phosphor screen and a CCD-camera to record images and diffraction patterns. In recent years, however, MCPs have become a limiting factor for these types of microscopy. Here, we report on a successful test series using a solid state hybrid pixel detector, Medipix 2, in LEEM and PEEM. Medipix 2 is a background-free detector with an infinite dynamic range, making it very promising for both real-space imaging and spectroscopy. We demonstrate a significant enhancement of both image contrast and resolution, as compared to MCPs. Since aging of the Medipix 2 detector is negligible for the electron energies used in LEEM/PEEM, we expect Medipix to become the detector of choice for a new generation of systems.

  15. Medipix 2 detector applied to low energy electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gastel, R. van, E-mail: R.vanGastel@utwente.nl [University of Twente, MESA Institute for Nanotechnology, P.O. Box 217, NL-7500 AE Enschede (Netherlands); Sikharulidze, I. [Leiden University, Leiden Institute of Chemistry, P.O. Box 9502, NL-2300 RA Leiden (Netherlands); Schramm, S. [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands); Abrahams, J.P. [Leiden University, Leiden Institute of Chemistry, P.O. Box 9502, NL-2300 RA Leiden (Netherlands); Poelsema, B. [University of Twente, MESA Institute for Nanotechnology, P.O. Box 217, NL-7500 AE Enschede (Netherlands); Tromp, R.M. [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands); IBM Research Division, T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598 (United States); Molen, S.J. van der [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands)

    2009-12-15

    Low energy electron microscopy (LEEM) and photo-emission electron microscopy (PEEM) traditionally use microchannel plates (MCPs), a phosphor screen and a CCD-camera to record images and diffraction patterns. In recent years, however, MCPs have become a limiting factor for these types of microscopy. Here, we report on a successful test series using a solid state hybrid pixel detector, Medipix 2, in LEEM and PEEM. Medipix 2 is a background-free detector with an infinite dynamic range, making it very promising for both real-space imaging and spectroscopy. We demonstrate a significant enhancement of both image contrast and resolution, as compared to MCPs. Since aging of the Medipix 2 detector is negligible for the electron energies used in LEEM/PEEM, we expect Medipix to become the detector of choice for a new generation of systems.

  16. New directions in low energy electron molecule collision calculations

    International Nuclear Information System (INIS)

    Burke, P.G.; Noble, C.J.

    1982-01-01

    New theoretical and computational methods for studying low energy electron molecule collisions are discussed. Having considered the fixed-nuclei approximation and the form of the expansion of the total collision wavefunction, the various approximations which have been made are examined, including the static plus model exchange approximation, the static exchange approximation and the close coupling approximation, particular attention being paid to methods of including the molecular charge polarisation. Various ways which have been developed to solve the resultant equations are discussed and it is found that there is increasing emphasis being given to methods which combine the advantages of discrete multi-centre analytic bases with single centre numerical bases. (U.K.)

  17. Does the effective Lagrangian for low-energy QCD scale?

    International Nuclear Information System (INIS)

    Birse, M.C.

    1994-01-01

    Quantum chromodynamics is not an approximately scale-invariant theory. Hence a dilaton field is not expected to provide a good description of the low-energy dynamics associated with the gluon condensate. Even if such a field is introduced, it remains almost unchanged in hadronic matter at normal densities. This is because the large glueball mass together with the size of the phenomenological gluon condensate ensure that changes to that condensate are very small at such densities. Any changes in hadronic masses and decay constants in matter generated by that condensate will be much smaller than those produced directly by changes in the quark condensate. Hence, masses and decay constants are not expected to display a universal scaling. (author)

  18. B meson mixing and low-energy dynamical flavour

    International Nuclear Information System (INIS)

    Chkareuli, J.L.

    1990-01-01

    The low-energy quantum flavour dynamics offered by the local horizontal symmetry SU(3) H for quark-lepton families is presented in some detail. It is shown that spontaneous breaking of this symmetry naturally leads to the simple Fritzsch ansatz for the quark mass matrices and simultaneously provides the observed magnitude of B d 0 -anti B d 0 mixing without any appreciable perturbation of the K 0 -anti K 0 system. This mixing determines a real scale for the masses of the SU(3) H gauge bosons. In marked contrast to the standard model this new approach is certain to give rise to small B s 0 -anti B s 0 mixing and large D 0 -anti D 0 mixing that can be of real interest in the near future. (orig.)

  19. Nuclear data and low energy nuclear research in Israel

    International Nuclear Information System (INIS)

    Yiftah, S.

    1977-04-01

    The Israel Nuclear Data and Low Energy Nuclear Research relevant to the International Nuclear Data Committee was continued in various institutions. The major experimental facilities consist of: A 5 Megawatt swimming pool enriched uranium reactor at the Soreq Nuclear Research Centre; A 26 Megawatt heavy water tank-type natural uranium reactor at the Negev Research Centre; A 6-million volt EN tandem accelerator at the Weizmann Institute of Science, Rehovot; The new most modern high energy 14 UD pelletron accelerator manufactured by the National Electrostatic Corporation of Middleton, Wisconsin, installed inside the Koffler Accelerator Tower at the Weizmann Institute of Science, Rehovot. Brief abstracts of the research work, both published and unpublished, listed according to the various laboratories, are reported in the following pages. (author)

  20. Cost analysis of low energy electron accelerator for film curing

    International Nuclear Information System (INIS)

    Ochi, Masafumi

    2003-01-01

    Low energy electron accelerators are recognized as one of the advanced curing means of converting processes for films and papers. In the last three years the price of the accelerator equipment has been greatly reduced. The targeted application areas are mainly processes of curing inks, coatings, and adhesives to make packaging materials. The operating cost analyses were made for electron beam (EB) processes over the conventional ones without EB. Then three new proposals for cost reduction of EB processes are introduced. Also being developed are new EB chemistries such as coatings, laminating adhesives and inks. EB processes give instantaneous cure and EB chemistries are basically non solvent causing less VOC emission to the environment. These developments of both equipment and chemistries might have a potential to change conventional packaging film industries. (author)

  1. Very low-energy hydrogen-antihydrogen scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Chamberlain, C.W.

    2003-01-01

    In view of current interest in the trapping of antihydrogen (H-bar) atoms at very low temperatures, we have carried out a calculation of s-wave hydrogen-antihydrogen scattering at very low energies, using the Kohn variational method, taking into account rearrangement scattering into the three channels that contain positronium in its ground state and lie closest to threshold. We find that our values for the elastic cross section are in good agreement with the values obtained by Jonsell et al. [2001 Phys. Rev. A 64 052712] using a distorted wave approximation. However, our values for the total rearrangement cross section are much larger than their values and we predict that cooling of H-bar by cold H would be considerably less efficient than was found to be the case by Jonsell et al.. (author)

  2. New results for single stage low energy carbon AMS

    International Nuclear Information System (INIS)

    Klody, G.M.; Schroeder, J.B.; Norton, G.A.; Loger, R.L.; Kitchen, R.L.; Sundquist, M.L.

    2005-01-01

    A new configuration of the NEC single stage, low energy carbon AMS system (U.S. Patent 6,815,666 B2) has been built and tested. The injector includes two 40-sample ion sources, electrostatic and magnetic analysis, and fast sequential injection. The gas stripper, analyzing magnet, electrostatic analyzer, and detector are on an open air 250 kV deck. Both 12 C and 13 C currents are measured on the deck after the stripper, and an SSB detector is used for 14 C counting. Injected 12 C and mass 13 ( 13 C and 12 CH) currents are also measured. Automated controls follow a user-specified run list for unattended operation. Initial test results show precision for 14 C/ 12 C ratios of better than 5 per mil, and backgrounds for unprocessed graphite of less than 0.005 x modern. We will report final results for precision, background, and throughput and discuss related design features

  3. Analysis of parity violating nuclear effects at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Desplanques, B; Missimer, J [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1978-05-15

    The authors present an analysis of parity-violating nuclear effects at low energy which attempts to circumvent the uncertainties due to the weak and strong nucleon-nucleon interactions at short distances. Extending Danilov's parametrization of the parity-violating nucleon-nucleon scattering amplitude, they introduce six parameters: one for the long-range contribution due to the pion exchange and five for the shorter-range contributions. This choice gives an accurate representation of parity-violating effects in the nucleon-nucleon system up to a lab energy of 75 MeV. For calculations in nuclei, an effective two-body potential is derived in terms of the parameters. The analysis of presently measured effects shows that they are consistent, and, in particular, that the circular polarization of photons in n + p ..-->.. d + ..gamma.. is not incompatible with the other measurements. It does not imply a dominant isotensor component.

  4. The reactor antineutrino anomaly and low energy threshold neutrino experiments

    Science.gov (United States)

    Cañas, B. C.; Garcés, E. A.; Miranda, O. G.; Parada, A.

    2018-01-01

    Short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. In this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. We discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. We find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. We also analyze the measurements of antineutrino scattering off electrons from short distance reactor experiments. In this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the Gallium anomaly.

  5. Auger vs resonance neutralization in low energy He+ ion scattering

    International Nuclear Information System (INIS)

    Woodruff, D.P.

    1983-01-01

    He + ions incident on a metal surface can neutralize either by an Auger or resonant charge exchange. While the Auger process has always been thought to be dominant, recent theoretical interest in the simpler one-electron resonance process has led to suggestions that this alone can account for the neutralization seen in low energy He + ion scattering. In this paper this assertion is analysed by looking at the wider information available on charge exchange processes for He + ion scattering through comparison with Li + ion scattering, the importance of multiple scattering in both these scattering experiments and the results of ion neutralization spectroscopy. These lead to the conclusion that while resonance neutralization to produce metastable He* may well occur at a substantial rate in He + ion scattering, the dominant process leading to loss of ions from the final scattered signal is Auger neutralization as originally proposed. (author)

  6. Linac4 Low Energy Beam Measurements with Negative Hydrogen

    CERN Document Server

    Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

    2014-01-01

    Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  7. Further evidence for low-energy protonium production in vacuum

    CERN Document Server

    Lodi Rizzini, E; Zurlo, N; Charlton, M; Amsler, C; Bonomi, G; Canali, C; Carraro, C; Fontana, A; Genova, P; Hayano, R; Jorgensen, L V; Kellerbauer, A; Lagomarsino, V; Landua, R; Macri, M; Manuzio, G; Montagna, P; Regenfus, C; Rotondi, A; Testera, G; Variola, A; van der Werf, D P

    2012-01-01

    We describe an experiment performed in the ATHENA apparatus in which there is evidence that the antiproton-proton bound state, protonium, has been produced at very low energies in vacuum following the interaction of cold antiprotons with a trapped cloud of molecular hydrogen ions. The latter were confined in a centrifugally separated belt outside a positron plasma used for antihydrogen formation. Studies have been performed at low positron plasma temperatures in which the protonium annihilation signal has been identified along with that from antihydrogen, and we discuss how their contributions can be disentangled. With the positron plasma heated to around 10000 K the ions become distributed in the positrons, and the majority of the annihilation signal can be explained in terms of protonium formation, as antihydrogen creation is heavily suppressed. In this case we compare the observed protonium formation rate with expectations from theory and find reasonable accord, when experimental systematics are taken into...

  8. Precocious scaling in antiproton-proton scattering at low energies

    International Nuclear Information System (INIS)

    Ion, D.B.; Petrascu, C.; Topor Pop, V.; Popa, V.

    1993-08-01

    The scaling of the diffraction peak in antiproton-proton scattering has been investigated from nera threshold up to 3 GeV/c laboratory momenta. It was shown that the scaling of the differential cross sections are evidentiated with a surprising accuracy not only at high energies, but also at very low ones (e.g. p LAB = 0.1 - 0.5 GeV/c), beyond the resonance and exotic resonance regions. This precocious scaling strongly suggests that the s-channel helicity conservation (SCHC) can be a peculiar property that should be tested in antiproton-proton interaction not only at high energies but also at low energy even below p LAB = 1 GeV/c. (author). 36 refs, 9 figs

  9. New development for low energy electron beam processor

    International Nuclear Information System (INIS)

    Takei, Taro; Goto, Hitoshi; Oizumi, Matsutoshi; Hirakawa, Tetsuya; Ochi, Masafumi

    2003-01-01

    Newly developed low-energy electron beam (EB) processors that have unique designs and configurations compared to conventional ones enable electron-beam treatment of small three-dimensional objects, such as grain-like agricultural products and small plastic parts. As the EB processor can irradiate the products from the whole angles, the uniform EB treatment can be achieved at one time regardless the complex shapes of the product. Here presented are two new EB processors: the first system has cylindrical process zone, which allows three-dimensional objects to be irradiated with one-pass treatment. The second is a tube-type small EB processor, achieving not only its compactor design, but also higher beam extraction efficiency and flexible installation of the irradiation heads. The basic design of each processor and potential applications with them will be presented in this paper. (author)

  10. Pion-nucleon interactions in low energy region

    International Nuclear Information System (INIS)

    Hiroshige, Noboru; Tsujimura, Tadakuni.

    1977-01-01

    Pion-nucleon interactions in low energy region (below 320 MeV in kinetic energy) are investigated on the basis of the one-particle-exchange model. The model is directly compared with the experimental data, i.e., differential cross sections and recoil nucleon polarizations, since phase shifts have not been uniquely determined. It is shown that these experimental data can be well reproduced by taking account of N (nucleon), Δ 33 , N 11 , N 13 , rho, f 0 and S (scalar meson) in the intermediate state. Some comments are given on the coupling constants which are determined so as to minimize chi-squared value (chi 2 ). Our predicted phase shifts for s-, p- and d-waves are also compared with other authors'. (auth.)

  11. Opportunistic Sensor Data Collection with Bluetooth Low Energy

    Directory of Open Access Journals (Sweden)

    Sergio Aguilar

    2017-01-01

    Full Text Available Bluetooth Low Energy (BLE has gained very high momentum, as witnessed by its widespread presence in smartphones, wearables and other consumer electronics devices. This fact can be leveraged to carry out opportunistic sensor data collection (OSDC in scenarios where a sensor node cannot communicate with infrastructure nodes. In such cases, a mobile entity (e.g., a pedestrian or a vehicle equipped with a BLE-enabled device can collect the data obtained by the sensor node when both are within direct communication range. In this paper, we characterize, both analytically and experimentally, the performance and trade-offs of BLE as a technology for OSDC, for the two main identified approaches, and considering the impact of its most crucial configuration parameters. Results show that a BLE sensor node running on a coin cell battery can achieve a lifetime beyond one year while transferring around 10 Mbit/day, in realistic OSDC scenarios.

  12. Opportunistic Sensor Data Collection with Bluetooth Low Energy.

    Science.gov (United States)

    Aguilar, Sergio; Vidal, Rafael; Gomez, Carles

    2017-01-23

    Bluetooth Low Energy (BLE) has gained very high momentum, as witnessed by its widespread presence in smartphones, wearables and other consumer electronics devices. This fact can be leveraged to carry out opportunistic sensor data collection (OSDC) in scenarios where a sensor node cannot communicate with infrastructure nodes. In such cases, a mobile entity (e.g., a pedestrian or a vehicle) equipped with a BLE-enabled device can collect the data obtained by the sensor node when both are within direct communication range. In this paper, we characterize, both analytically and experimentally, the performance and trade-offs of BLE as a technology for OSDC, for the two main identified approaches, and considering the impact of its most crucial configuration parameters. Results show that a BLE sensor node running on a coin cell battery can achieve a lifetime beyond one year while transferring around 10 Mbit/day, in realistic OSDC scenarios.

  13. Bluetooth low energy: wireless connectivity for medical monitoring.

    Science.gov (United States)

    Omre, Alf Helge

    2010-03-01

    Electronic wireless sensors could cut medical costs by enabling physicians to remotely monitor vital signs such as blood pressure, blood glucose, and blood oxygenation while patients remain at home. According to the IDC report "Worldwide Bluetooth Semiconductor 2008-2012 Forecast," published November 2008, a forthcoming radio frequency communication ("wireless connectivity") standard, Bluetooth low energy, will link wireless sensors via radio signals to the 70% of cell phones and computers likely to be fitted with the next generation of Bluetooth wireless technology, leveraging a ready-built infrastructure for data transmission. Analysis of trends indicated by this data can help physicians better manage diseases such as diabetes. The technology also addresses the concerns of cost, compatibility, and interoperability that have previously stalled widespread adoption of wireless technology in medical applications. (c) 2010 Diabetes Technology Society.

  14. Linac4 low energy beam measurements with negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Scrivens, R., E-mail: richard.scrivens@cern.ch; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T. [CERN, 1211 Geneva 23 (Switzerland)

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  15. Search for low Energy solar Axions with CAST

    CERN Document Server

    Cantatore, Giovanni; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Boydag, F.S.; Brauninger, H.; Cantatore, G.; Carmona, J.M.; Cebrian, S.; Cetin, S.A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O.B.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Franz, J.; Galan, J.; Gazis, E.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, F.H.; Hikmet, I.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Karageorgopoulou, T.; Karuza, M.; Konigsmann, Kay; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lozza, V.; Lutz, G.; Luzon, G.; Miller, D.; Morales, A.; Morales, J.; Niinikoski, T.; Nordt, A.; Ortiz, A.; Papaevangelou, T.; Pivovaroff, M.; Placci, A.; Raiteri, G.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Solanki, S.K.; Soufli, R.; Stewart, L.; Tsagri, M.; van Bibber, K.; Villar, J.; Vogel, J.; Walckiers, L.; Zioutas, K.

    2008-01-01

    We have started the development of a detector system, sensitive to single photons in the eV energy range, to be suitably coupled to one of the CAST magnet ports. This system should open to CAST a window on possible detection of low energy Axion Like Particles emitted by the sun. Preliminary tests have involved a cooled photomultiplier tube coupled to the CAST magnet via a Galileian telescope and a switched 40 m long optical fiber. This system has reached the limit background level of the detector alone in ideal conditions, and two solar tracking runs have been performed with it at CAST. Such a measurement has never been done before with an axion helioscope. We will present results from these runs and briefly discuss future detector developments.

  16. Manipulation of rare isotope beams - from high to low energies

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States)], E-mail: bollen@nscl.msu.edu; Campbell, C.; Chouhan, S.; Guenaut, C.; Lawton, D.; Marti, F. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Pang, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Schwarz, S.; Zeller, A.F.; Zavodszky, P. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States)

    2008-10-15

    Projectile fragmentation above 50 MeV/u and in-flight separation is a powerful technique for the production and delivery of rare isotopes. The production is fast and chemistry independent, providing nuclides far away from the valley of beta stability and for a very large range of elements. These benefits can be maximized if the produced rare isotopes are made available also as low-energy beams (<15 MeV/u) and at rest. For this purpose the fast beams need to be slowed down and thermalized before being re-accelerated to the desired energy. This can be achieved with gas stopping techniques. This paper discusses various aspects of stopping fast rare isotope beams, including the development of a 'cyclotron gas stopper' that promises to overcome the limitations of present linear gas stopping schemes.

  17. Low Energy Reaction cell for advanced space power applications

    International Nuclear Information System (INIS)

    Miley, George H.; Rice, Eric

    2001-01-01

    Power units using Low Energy Reactions (LENRs) are under study as a radical new approach to power units that could potentially replace nuclear and chemical power sources for a number of space applications. These cells employ thin metallic films (order of 500 deg., using variously Ni, Pd and Ti) as cathodes with various electrolytes such as 0.5-1 molar lithium sulfate in light water. Power densities exceeding 10 W/cm3 in the thin-films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies ∼20% of the total cell volume. If this is achieved, overall power densities of ∼20 W/cm3 appear feasible, opening the way to a number of potential applications ranging from distributed power units in spacecraft to advanced propulsion

  18. Five low energy phosphorene allotropes constructed through gene segments recombination.

    Science.gov (United States)

    He, Chaoyu; Zhang, ChunXiao; Tang, Chao; Ouyang, Tao; Li, Jin; Zhong, Jianxin

    2017-04-27

    Based on the crystal structures of the previously proposed low energy η-P and θ-P, five new phosphorene allotropes were predicted through gene segments recombination method. These five new phosphorene allotropes are confirmed dynamically stable and energetically more favorable than their parents (η-P and θ-P). Especially, the XX-XX type G1-P is confirmed energetically more favorable than most of all the previously proposed phosphorene allotropes, including black phosphorene and blue phosphorene, which is highly expected to be synthesized in future experiment through vapor deposition or epitaxial growth method like blue β-P. The calculated results also show that such a new promising phosphorene allotrope G1-P is a potential candidate for application in nano-electronics according to its middle band gap of about 1.491 eV from DFT-HSE06 calculation.

  19. The nucleon-antinucleon interaction at low energies

    International Nuclear Information System (INIS)

    Alvear, C.

    1977-08-01

    A theoretical analysis is made of recent low energy data relative to scattering process p sup(-)d → p + pions from 300 to 600 Mev/c laboratory incident momentum, with the purpose of obtaining information about resonances in the pure iso-spin system p sup(-)n (I = 1). The single and double term of the multiple scattering series are evaluated using a formalism based on Glauber theory and Feynman rules. Then, the differential cross section with respect to the invariant mass of the produced pions is obtained. The theoretical results are used to analyse the available data, which are then shown to be consistent with a non resonant behavior of the p sup(-)n system. (Author) [pt

  20. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    In the future energy system a considerable increase in the penetration of renewable energy is expected, challenging the stability of the system, as both production and consumption will have fluctuating patterns. Hence, the concept of energy flexibility will be necessary in order for the consumption...... to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study...... the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...

  1. Low energy current accumulator for high-energy proton rings

    International Nuclear Information System (INIS)

    Month, M.

    1977-01-01

    Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum

  2. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The background resonance Δ(1230), Nsup(*)(1520), Nsup(*)(1470) and Nsup(*)(1535)pion and axial-vector amplitudes are first calculated in the soft pion and on-shell configuration, respectively. Then a comparison is made with the usual soft pion theorems and on-shell low-energy expansions of current algebra as worked out in the previous paper. The agreement is good and we also deduce a nucleon dipole form factor axial-vector mass of msub(A)approximately equal to 1,23 GeV. Finally an approximate value for the non-strange current quark mass of m equal to 0,64 +- 1,11μ is extracted from the data

  3. Low-energy house in Sisimiut - Measurement equipment

    Energy Technology Data Exchange (ETDEWEB)

    Hvidthoeft Delff Andersen, P.; Rode, C.; Madsen, Henrik

    2013-08-15

    This paper documents the measurement equipment in a low-energy house in Sisimiut, Greenland. Detailed measurements are being taken on energy consumption, indoor temperatures, floor heating, ventilation, open/closed state of doors and windows, and indoors climate. Equipped with a central control unit, experiments can be designed in order to study heat dynamics of the building. It is described how to plan and execute such experiments in one apartment in the building. The building also features both a solar thermal system and extra buffer tank facilitating testing of storage strategies on the power generated by the solar thermal system. A weather station equipped with thermometer, pyranometer and anemometer is installed on the building as well. Finally, it is described how to retrieve data from an SQL server which is configured to take monthly backups. R functions have been implemented to fetch and prepare the data for time series analysis. Examples are given on the use of these. (Author)

  4. Geometric low-energy effective action in a doubled spacetime

    Science.gov (United States)

    Ma, Chen-Te; Pezzella, Franco

    2018-05-01

    The ten-dimensional supergravity theory is a geometric low-energy effective theory and the equations of motion for its fields can be obtained from string theory by computing β functions. With d compact dimensions, an O (d , d ; Z) geometric structure can be added to it giving the supergravity theory with T-duality manifest. In this paper, this is constructed through the use of a suitable star product whose role is the one to implement the weak constraint on the fields and the gauge parameters in order to have a closed gauge symmetry algebra. The consistency of the action here proposed is based on the orthogonality of the momenta associated with fields in their triple star products in the cubic terms defined for d ≥ 1. This orthogonality holds also for an arbitrary number of star products of fields for d = 1. Finally, we extend our analysis to the double sigma model, non-commutative geometry and open string theory.

  5. Hierarchical fuzzy control of low-energy building systems

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhen; Dexter, Arthur [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom)

    2010-04-15

    A hierarchical fuzzy supervisory controller is described that is capable of optimizing the operation of a low-energy building, which uses solar energy to heat and cool its interior spaces. The highest level fuzzy rules choose the most appropriate set of lower level rules according to the weather and occupancy information; the second level fuzzy rules determine an optimal energy profile and the overall modes of operation of the heating, ventilating and air-conditioning system (HVAC); the third level fuzzy rules select the mode of operation of specific equipment, and assign schedules to the local controllers so that the optimal energy profile can be achieved in the most efficient way. Computer simulation is used to compare the hierarchical fuzzy control scheme with a supervisory control scheme based on expert rules. The performance is evaluated by comparing the energy consumption and thermal comfort. (author)

  6. First evidence of low energy enhancement in Ge isotopes

    Directory of Open Access Journals (Sweden)

    Renstrøm T.

    2015-01-01

    Full Text Available The γ-strength functions and level densities of 73,74Ge have been extracted from particle-γ coincidence data using the Oslo method. In addition the γ-strength function of 74Ge above the neutron separation threshold, Sn = 10.196 MeV has been extracted from photoneutron measurements. When combined, these two experiments give a γ-strength function covering the energy range of ∼1-13 MeV for 74Ge. This thorough investigation of 74Ge is a part of an international campaign to study the previously reported low energy enhancement in this mass region in the γ-strength function from ∼3MeV towards lower γ energies. The obtained data show that both 73,74Ge display an increase in strength at low γ energies.

  7. Luminescence model with quantum impact parameter for low energy ions

    CERN Document Server

    Cruz-Galindo, H S; Martínez-Davalos, A; Belmont-Moreno, E; Galindo, S

    2002-01-01

    We have modified an analytical model of induced light production by energetic ions interacting in scintillating materials. The original model is based on the distribution of energy deposited by secondary electrons produced along the ion's track. The range of scattered electrons, and thus the energy distribution, depends on a classical impact parameter between the electron and the ion's track. The only adjustable parameter of the model is the quenching density rho sub q. The modification here presented, consists in proposing a quantum impact parameter that leads to a better fit of the model to the experimental data at low incident ion energies. The light output response of CsI(Tl) detectors to low energy ions (<3 MeV/A) is fitted with the modified model and comparison is made to the original model.

  8. Development and Implementation of Photonuclear Cross-Section Data for Mutually Coupled Neutron-Photon Transport Calculations in the Monte Carlo N-Particle (MCNP) Radiation Transport Code

    International Nuclear Information System (INIS)

    White, Morgan C.

    2000-01-01

    The fundamental motivation for the research presented in this dissertation was the need to development a more accurate prediction method for characterization of mixed radiation fields around medical electron accelerators (MEAs). Specifically, a model is developed for simulation of neutron and other particle production from photonuclear reactions and incorporated in the Monte Carlo N-Particle (MCNP) radiation transport code. This extension of the capability within the MCNP code provides for the more accurate assessment of the mixed radiation fields. The Nuclear Theory and Applications group of the Los Alamos National Laboratory has recently provided first-of-a-kind evaluated photonuclear data for a select group of isotopes. These data provide the reaction probabilities as functions of incident photon energy with angular and energy distribution information for all reaction products. The availability of these data is the cornerstone of the new methodology for state-of-the-art mutually coupled photon-neutron transport simulations. The dissertation includes details of the model development and implementation necessary to use the new photonuclear data within MCNP simulations. A new data format has been developed to include tabular photonuclear data. Data are processed from the Evaluated Nuclear Data Format (ENDF) to the new class ''u'' A Compact ENDF (ACE) format using a standalone processing code. MCNP modifications have been completed to enable Monte Carlo sampling of photonuclear reactions. Note that both neutron and gamma production are included in the present model. The new capability has been subjected to extensive verification and validation (V and V) testing. Verification testing has established the expected basic functionality. Two validation projects were undertaken. First, comparisons were made to benchmark data from literature. These calculations demonstrate the accuracy of the new data and transport routines to better than 25 percent. Second, the ability to

  9. Development and Implementation of Photonuclear Cross-Section Data for Mutually Coupled Neutron-Photon Transport Calculations in the Monte Carlo N-Particle (MCNP) Radiation Transport Code

    Energy Technology Data Exchange (ETDEWEB)

    White, Morgan C. [Univ. of Florida, Gainesville, FL (United States)

    2000-07-01

    The fundamental motivation for the research presented in this dissertation was the need to development a more accurate prediction method for characterization of mixed radiation fields around medical electron accelerators (MEAs). Specifically, a model is developed for simulation of neutron and other particle production from photonuclear reactions and incorporated in the Monte Carlo N-Particle (MCNP) radiation transport code. This extension of the capability within the MCNP code provides for the more accurate assessment of the mixed radiation fields. The Nuclear Theory and Applications group of the Los Alamos National Laboratory has recently provided first-of-a-kind evaluated photonuclear data for a select group of isotopes. These data provide the reaction probabilities as functions of incident photon energy with angular and energy distribution information for all reaction products. The availability of these data is the cornerstone of the new methodology for state-of-the-art mutually coupled photon-neutron transport simulations. The dissertation includes details of the model development and implementation necessary to use the new photonuclear data within MCNP simulations. A new data format has been developed to include tabular photonuclear data. Data are processed from the Evaluated Nuclear Data Format (ENDF) to the new class ''u'' A Compact ENDF (ACE) format using a standalone processing code. MCNP modifications have been completed to enable Monte Carlo sampling of photonuclear reactions. Note that both neutron and gamma production are included in the present model. The new capability has been subjected to extensive verification and validation (V&V) testing. Verification testing has established the expected basic functionality. Two validation projects were undertaken. First, comparisons were made to benchmark data from literature. These calculations demonstrate the accuracy of the new data and transport routines to better than 25 percent. Second

  10. Photon energy-fluence correction factor in low energy brachytherapy

    International Nuclear Information System (INIS)

    Antunes, Paula C.G.; Yoriyaz, Hélio; Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo

    2017-01-01

    The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D tis ) and dose-to-water (D w ). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the 125 I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

  11. Photon energy-fluence correction factor in low energy brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Paula C.G.; Yoriyaz, Hélio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo, E-mail: pacrisguian@gmail.com [Department of Atomic, Molecular, and Nuclear Physics and Instituto de Física Corpuscular (UV-CSIC), University of Valencia (Spain)

    2017-07-01

    The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D{sub tis}) and dose-to-water (D{sub w}). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the {sup 125}I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

  12. Low energy ion beam dynamics of NANOGAN ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sarvesh, E-mail: sarvesh@iuac.res.in; Mandal, A.

    2016-04-01

    A new low energy ion beam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ion beams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ion beams. Higher emittance at low energy of intense ion beam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ion beam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ion beams similar to the trend observed theoretically.

  13. Performance Evaluation of Bluetooth Low Energy: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Jacopo Tosi

    2017-12-01

    Full Text Available Small, compact and embedded sensors are a pervasive technology in everyday life for a wide number of applications (e.g., wearable devices, domotics, e-health systems, etc.. In this context, wireless transmission plays a key role, and among available solutions, Bluetooth Low Energy (BLE is gaining more and more popularity. BLE merges together good performance, low-energy consumption and widespread diffusion. The aim of this work is to review the main methodologies adopted to investigate BLE performance. The first part of this review is an in-depth description of the protocol, highlighting the main characteristics and implementation details. The second part reviews the state of the art on BLE characteristics and performance. In particular, we analyze throughput, maximum number of connectable sensors, power consumption, latency and maximum reachable range, with the aim to identify what are the current limits of BLE technology. The main results can be resumed as follows: throughput may theoretically reach the limit of ~230 kbps, but actual applications analyzed in this review show throughputs limited to ~100 kbps; the maximum reachable range is strictly dependent on the radio power, and it goes up to a few tens of meters; the maximum number of nodes in the network depends on connection parameters, on the network architecture and specific device characteristics, but it is usually lower than 10; power consumption and latency are largely modeled and analyzed and are strictly dependent on a huge number of parameters. Most of these characteristics are based on analytical models, but there is a need for rigorous experimental evaluations to understand the actual limits.

  14. Negotiating comfort in low energy housing: The politics of intermediation

    International Nuclear Information System (INIS)

    Grandclément, Catherine; Karvonen, Andrew; Guy, Simon

    2015-01-01

    Optimising the energy performance of buildings is technically and economically challenging but it also has significant social implications. Maintaining comfortable indoor conditions while reducing energy consumption involves careful design, construction, and management of the built environment and its inhabitants. In this paper, we present findings from the study of a new low energy building for older people in Grenoble, France where conflicts emerged over the simultaneous pursuit of energy efficiency and comfort. The findings contribute to the contemporary literature on the sociotechnical study of buildings and energy use by focusing on intermediation, those activities that associate a technology to end users. Intermediation activities take many forms, and in some cases, can result in the harmonisation or alignment of energy efficiency goals and comfort goals. In other cases, intermediation is unsuccessful, leading to the conventional dichotomy between optimising technical performance and meeting occupant preferences. By highlighting the multiple ways that comfort and energy efficiency is negotiated, we conclude that buildings are provisional achievements that are constantly being intermediated. This suggests that building energy efficiency policies and programmes need to provide opportunities for intermediaries to negotiate the desires and preferences of the multiple stakeholders that are implicated in low energy buildings. -- Highlights: •Energy efficiency and comfort are two possibly contradictory aims of buildings. •We study the pursuit of these aims at the occupation stage of a new building. •Aligning these aims involve negotiating them with occupants. •Intermediation processes are key to such negotiations. •Intermediation processes involve both actors and technical devices

  15. Performance of broiler chicken fed multicarbohydrases supplemented low energy diet

    Directory of Open Access Journals (Sweden)

    Kumar Govil

    2017-07-01

    Full Text Available Aim: Objective of this study was to investigate the effect of multicarbohydrases supplementation on performance of broilers fed low energy diet. Materials and Methods: A total of 75 days old chicks were selected and randomly divided into three treatments groups (T1, T2, and T3; each group contained 25 chicks distributed in five replicates of five chicks each. T1 group (positive control was offered control ration formulated as per Bureau of Indian Standards recommendations. In T2 group (negative control ration, metabolizable energy (ME was reduced by 100 kcal/kg diet. T3 group ration was same as that of T2 except that it was supplemented with multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton. Feed intake and body weight of all experimental birds were recorded weekly. Metabolic trial was conducted for 3 days at the end of experiment to know the retention of nutrients. Results: Significant improvement (p<0.01 was observed in total weight gain, feed conversion efficiency, and performance index in broilers under supplementary group T3 as compared to T1 and T2 groups. Retention of crude protein and ether extract was significantly increased (p<0.05 in T3 group supplemented with multicarbohydrases as compared to other groups. Retention of dry matter, crude fiber, and nitrogen-free extract was comparable in all the three groups. Significantly highest dressed weight, eviscerated weight, and drawn weight (% of live body weight were observed in multicarbohydrases supplemented T3 group, however it was comparable in T1 and T2 groups. Conclusion: It was concluded that the supplementation of multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton in low energy diet improved overall performance of broilers.

  16. Variations of Low-energy Ion Distributions Measured in the Heliosheath

    International Nuclear Information System (INIS)

    Decker, R. B.; Roelof, E. C.; Hill, M. E.; Krimigis, S. M.

    2010-01-01

    This report is an update of low-energy ion intensities and angular distributions measured recently by the Low Energy Charged Particle instruments on the Voyager 1 and 2 spacecraft in the inner heliosheath.

  17. Probing quark mass effects in low-energy hadron physics

    International Nuclear Information System (INIS)

    Ditsche, Christoph

    2012-01-01

    Since quarks are confined inside hadrons, their properties as well as their contributions to hadronic observables can be assessed by indirect methods only. As the strength of the strong interaction increases with the spatial distance, the treatment of quantum chromodynamics at low energies in general requires non-perturbative methods like dispersion relations or lattice gauge theory. Based on the fact that the light quark masses are very small with respect to the typical hadronic mass scales for mesons and baryons, furthermore effective field theories can be constructed to describe low-energy properties and dynamics of hadrons perturbatively. The present work is concerned with two particularly interesting hadronic processes that are closely related to the light quark masses. Although distinct theoretical frameworks utilizing different calculational techniques are applied, in both cases the investigations at hand are prerequisites for high-precision analyses of the respective quark-mass effects. In the first part of this thesis, we investigate higher-order isospin-breaking effects in η→3π decays, namely η→π 0 π + π - and η→3π 0 , in chiral perturbation theory. By evaluating the second-order mixed strong and electromagnetic isospin-breaking corrections, we confirm the picture that the electromagnetic contributions are small. Therefore, η→3π is perfectly suited to extract isospin-breaking ratios of light quark masses via comparing theoretical predictions with experimental results. Since for an accurate determination a detailed description of the Dalitz plot distributions is necessary, we study the different effects of higher-order isospin breaking in η→3π on a more general basis. In particular, we investigate corrections to isospin relations between both decay channels at the level of Dalitz plot parameters, showing that the branching ratio of the two partial decay widths entails sizeable uncertainties. In the second part, we develop a dispersive

  18. Low-energy lepton violation from supersymmetric flipped SU(5)

    Energy Technology Data Exchange (ETDEWEB)

    Brahm, D.E.; Hall, L.J. (Physics Department, University of California, Berkeley, California 94720 (US) Theoretical Physics Group, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720)

    1989-10-01

    We construct a supersymmetric flipped SU(5){direct product}U(1) model which violates {ital R} parity and electron number at low energies, through a superpotential term (1/2{ital C}{sup {ital ijk}}L{sub i}L{sub j}E{sub k}{sup c}). Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the {ital C}{sup {ital ijk}} coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting {ital Z}{sup 0} decays are predicted: e.g., {ital Z}{sup 0}{r arrow}e{sup {minus}}{mu}{sup +}e{sup +}{mu}{sup {minus}} with invariant-mass peaks in the ({ital e},{mu}) channels.

  19. Dose controlled low energy electron irradiator for biomolecular films.

    Science.gov (United States)

    Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

    2016-03-01

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  20. Generalized hidden symmetry for low-energy hadron phsics

    International Nuclear Information System (INIS)

    Kaiser, N.; Meissner, U.G.

    1990-01-01

    We present a detailed study of an effective chiral meson lagrangian involving pseudoscalar, vector and axial-vector mesons. We employ the recently proposed technique to introduce vector and axial-vector mesons as composite gauge bosons of an extended hidden gauge symmetry of the non-linear σ-model. In particular, we write down the most general anomalous action (Wess-Zumino term) in accordance with low-energy theorems and chiral symmetry. The global flavor anomalies of QCD are given by the standard (5-dimensional) Wess-Zumino-Witten action of the pseudoscalar mesons, whereas all the processes violating natural parity for the vectors and axials are chirally (gauge) symmetric and therefore do not contribute to the Wess-Zumino anomaly equation. We find fourteen independent terms with a priori unknown (real) coefficients. We are able to fix some of these coefficients from anomalous hadronic and radiative vector/axial-vector meson decays. A comparison to the gauged Wess-Zumino action in the so-called massive Yang-Mills approach shows that both anomalous actions are indeed equivalent for a special choice of the unknown coefficients. We finally propose a realistic two-flavor chiral effective lagrangian incorporating pions, the vector mesons ρ and ω as well as the axial A 1 meson which should be used in skyrmion physics at energy scales up to about 1 GeV. (orig.)