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1

Investigation of deuteron breakup and deuteron-induced fission on actinide nuclei at low incident energies  

NASA Astrophysics Data System (ADS)

The dominance of the deuteron breakup mechanism around the Coulomb barrier is shown by an analysis of the 231Pa(d,3n)230U reaction excitation function, while the same attribute was found within a former assessment for the deuteron-induced fission. The present alternative result is obtained by taking into account, in addition to pre-equilibrium and compound-nucleus processes, the opposite effects of deuteron breakup, namely the decrease of the deuteron total reaction cross section, and the inelastic-breakup enhancement of various deuteron-induced reaction channels.

Avrigeanu, M.; Avrigeanu, V.; Koning, A. J.

2012-03-01

2

Investigation of the intermediate-energy deuteron breakup reaction  

SciTech Connect

The Udagawa-Tamura formalism is employed to calculate the proton singles both in the bound and unbound regions. Both the Elastic-Breakup (EB) and the Breakup-Fusion (BF) processes are considered to calculate the doubly-differential cross section for light and intermediate mass nuclei. The calculated spectra for 25 and 56 MeV deuterons reproduce the experimental spectra very well except for the spectra at large angle and at low energies, of the outgoing particle. Contributions due to precompound and evaporation processes are estimated to supplement the spectral results based on the Elastic-Breakup and Breakup-Fusion mechanisms. An extension of the model calculations to higher deuteron energies is being made to test the (EB + BF) model limitations. 5 refs., 1 fig.

Divadeenam, M.; Ward, T.E.; Mustafa, M.G.; Udagawa, T.; Tamura, T.

1989-01-01

3

The Polarized Deuteron Breakup Experiment at COSY  

NASA Astrophysics Data System (ADS)

A study of the deuteron breakup reaction pd --> (pp)n with forward emission of a fast proton pair with small excitation energy Epp < 3 MeV has been performed using the ANKE spectrometer at COSY Jülich. The differential cross section of the breakup reaction, averaged up to 8° over the cm polar angle of the total momentum of the pp pairs, has been obtained at six proton beam energies Tp = 0.6, 0.7, 0.8, 0.95, 1.35, and 1.9 GeV. A first measurement of the vector analyzing power Ayp has been carried out, using a polarization normalization obtained with the EDDA detector. In addition, for the first time asymmetries of pvec d elastic scattering at Tp = 500 MeV have been recorded with the spectator setup at ANKE.

Rathmann, F.; Barsov, S.; Dymov, S.; Kacharava, A.; Khoukaz, A.; Komarov, V.; Kulikov, A.; Kurbatov, A.; Lang, N.; Lehmann, I.; Lorentz, B.; Macharashvili, G.; Mussgiller, A.; Paetz Gen. Schieck, H.; Schleichert, R.; Seyfarth, H.; Steffens, E.; Ströher, H.; Uzikov, Yu.; Yaschenko, S.; Zalikhanov, B.

2003-07-01

4

Quasielastic Neutron-Induced Deuteron Breakup.  

NASA Astrophysics Data System (ADS)

An experiment to measure the quasielastic d(n,np)n scattering cross-section was conducted at the Los Alamos Neutron Science Center (LANSCE) at intermediate incident neutron energies, ranging up to 800 MeV. Scattered protons from deuteron breakup travel through a magnetic spectrometer on beam right, consisting of a thin ?E scintillator, three drift chambers, two permanent magnets, and two thin E scintillators. An array of nine two-meter high plastic scintillators detects scattered neutrons on beam left. Analysis of the data from this experiment is underway to determine the scattered angles and energies of the particles, and subsequently the scattering cross-section for the n-d breakup reaction.

Koehler, Katrina; Kroening, Peter; Slye, Jonathon; Turkewitz, Jared; Uemura, Sho; Henzl, Vlad; Matthews, June; Wender, Steve; Yuly, Mark

2010-11-01

5

Probing vector mesons in deuteron breakup reactions  

NASA Astrophysics Data System (ADS)

We study vector meson photoproduction from the deuteron at high momentum transfer, accompanied by the breakup of the deuteron into a proton and neutron. The large ?t involved allows one of the nucleons to be identified as struck, and the other as a spectator to the ?N?VN subprocess. Corrections to the plane wave impulse approximation involve final-state interactions (FSIs) between the struck nucleon or the vector meson, either of which is energetic, with the slow spectator nucleon. In this regime, the eikonal approximation is valid, and so is employed to calculate the cross section for the reaction. Due to the high-energy nature of the FSIs, the maxima of the rescatterings are located at nearly transverse directions of the fast hadrons. This results in two peaks in the angular distribution of the spectator nucleon, each corresponding to either the V-N or the p-n rescattering. The V-N peak provides a means of probing the V-N interaction. This is checked for near-threshold ? and J/? photoproduction reactions, which demonstrate that the V-N peak can be used to extract the largely unknown amplitudes of ?-N and J/?-N interactions. Two additional phenomena are observed when extending the calculation of J/? photoproduction to the subthreshold and high-energy domains. In the first case we observe overall suppression of FSI effects due to a restricted phase space for subthreshold production in the rescattering amplitude. In the second, we observe cancellation of the V-N rescattering amplitudes for vector mesons produced off of different nucleons in the deuteron.

Freese, Adam J.; Sargsian, Misak M.

2013-10-01

6

Deuteron–proton breakup at medium energies  

NASA Astrophysics Data System (ADS)

Recently, the database for the breakup of a deuteron in collision with a proton has been significantly enriched in the domain of medium energies. High precision experimental data for the cross section, vector (proton)-analyzing power and vector- and tensor (deuteron)-analyzing powers were collected with detection systems covering a large part of the phase space of the 1H(vec d, pp)n and 2H(vec p, pp)n reactions. A series of experiments were carried out with deuteron beams with energies of 100, 130 and 160 MeV and proton beams with energies of 135 and 190 MeV, each of them providing a few hundred data points per observable, obtained on systematic grids of kinematical variables within the studied angular ranges. Usage of the multidetector systems with significant solid angle coverage provides not only very rich data sets but also a good opportunity for controlling the consistency of the results. The ways of exploiting all these advantages in high precision measurements are discussed. The experimental results are compared with the theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in different ways: realistic nucleon–nucleon (NN) potentials are combined with model 3N forces (3NF) or with an effective 3N interaction resulting from the explicit treatment of the ?-isobar excitation. On top of the NN and 3N nuclear forces Coulomb interaction can be also included into the calculational framework. Relativistic calculations can be performed with realistic NN potentials alone. 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, while at the next order without taking into account the corresponding 3NF contributions. Comparing the calculated observables with the experimental data shows the sensitivity of the cross sections to 3NFs and to Coulomb force effects, while there is no sensitivity of the deuteron vector analyzing powers to any additional dynamics beyond the NN forces. The behavior of the tensor analyzing powers and of the proton analyzing powers at higher energy is rather complicated, showing discrepancies between the calculations and the experimental data which must be considered as indications of deficiencies in the spin part of the assumed models of the 3N system dynamics. The richness of the database calls for a systematic survey of the results, therefore kinematical coordinates convenient for that purpose and certain methods of comparison to the theoretical calculations are discussed, together with signposts to future developments in the field of 3N system studies.

Kistryn, St.; Stephan, E.

2013-06-01

7

Faddeev Equations for Deuteron Break-Up on alpha Particles.  

National Technical Information Service (NTIS)

Faddeev equations for deuteron break-up on alpha particles are given. Total cross-sections for the reaction process d+ alpha implies n+p+ alpha are calculated by means of the Faddeev equations and separable potentials. Numerical solution of the resulting ...

A. Osman

1976-01-01

8

Hard breakup of the deuteron into two ? isobars  

NASA Astrophysics Data System (ADS)

We study high-energy photodisintegration of the deuteron into two ? isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of pn??? scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the pn??? scattering. We predict that the cross section of the deuteron breakup to ?++?- is 4-5 times larger than that of the breakup to the ?+?0 channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard ? isobars are the result of the disintegration of the preexisting ?? components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both ?++?- and ?+?0 channels to be similar.

Granados, Carlos G.; Sargsian, Misak M.

2011-05-01

9

Hard breakup of the deuteron into two ? -isobars  

NASA Astrophysics Data System (ADS)

Photodisintegration of the deuteron into two ?-isobars at large center of mass angles is studied within the QCD hard rescattering model (HRM). According to the HRM, the reaction proceeds in three main steps: the photon knocks the quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons emerging at large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of pn->?? scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. We predict that the cross section of the deuteron breakup to &++circ;&-circ; is 4-5 times larger than that of the breakup to the &+circ;0? channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard ?-isobars are the result of the disintegration of initial ?? components of the deuteron wave function. In this case, the angular distributions and cross sections of the breakup in both &++circ;&-circ; and &+circ;0? channels are expected to be similar.

Granados, Carlos; Sargsian, Misak

2011-04-01

10

Hard breakup of the deuteron into two {Delta} isobars  

SciTech Connect

We study high-energy photodisintegration of the deuteron into two {Delta} isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of pn{yields}{Delta}{Delta} scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the pn{yields}{Delta}{Delta} scattering. We predict that the cross section of the deuteron breakup to {Delta}{sup ++}{Delta}{sup -} is 4-5 times larger than that of the breakup to the {Delta}{sup +}{Delta}{sup 0} channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard {Delta} isobars are the result of the disintegration of the preexisting {Delta}{Delta} components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both {Delta}{sup ++}{Delta}{sup -} and {Delta}{sup +}{Delta}{sup 0} channels to be similar.

Granados, Carlos G.; Sargsian, Misak M. [Florida International University, Miami, Florida 33199 (United States)

2011-05-15

11

Three-body break-up in deuteron-deuteron scattering at 65 MeV/nucleon  

SciTech Connect

In an experiment with a 65 MeV/nucleon polarized deuteron beam on a liquid-deuterium target at Kernfysisch Versneller Instituut, several multibody final states in deuteron-deuteron scattering were identified. For these measurements, a unique and advanced detection system, called the Big Instrument for Nuclear-polarization Analysis, was utilized. We demonstrate the feasibility of measuring vector and tensor polarization observables of the deuteron break-up reaction leading to a three-body final state. The polarization observables were determined with high precision in a nearly background-free experiment. The analysis procedure and some results are presented.

Ramazani-Moghaddam-Arani, A. [Department of Physics, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); KVI, University of Groningen, Groningen (Netherlands); Amir-Ahmadi, H. R.; Biegun, A.; Joulaeizadeh, L.; Kalantar-Nayestanaki, N.; Mardanpour, H.; Messchendorp, J. G.; Moeini, H.; Shende, S. V. [KVI, University of Groningen, Groningen (Netherlands); Bacher, A. D.; Bailey, C. D.; Stephenson, E. J. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana (United States); Eslami-Kalantari, M. [KVI, University of Groningen, Groningen (Netherlands); Department of Physics, Faculty of Science, Yazd University, Yazd (Iran, Islamic Republic of); Gasparic, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Kistryn, St.; Sworst, R. [Institute of Physics, Jagiellonian University, Cracow (Poland); Kozela, A. [Henryk Niewodniczanski, Institute of Nuclear Physics, Cracow (Poland); Micherdzinska, A. M. [University of Winnipeg, Winnipeg (Canada); Stephan, E. [Institute of Physics, University of Silesia, Katowice (Poland)

2011-02-15

12

Deuteron break-up and three body forces  

NASA Astrophysics Data System (ADS)

The nucleon induced deuteron break-up reaction is only beginning to be set in an accurate quantitative basis near threshold and promises to yield precious information on nuclear interactions. The reactions d+p ? p+p+n, bombarding protons with deuterons have an interesting "magnifying" glass effect which allows a very detailed study of anomalies in the correlation cross section. The n+d?n+n+p reaction should also be investigated near threshold with high resolution neutron beams, or with techniques permitting to extract high resolution spectra, like associated particle tagging in the reactions producing the neutron beam. The field here is wide open, although the n-n interaction is less well known than the p-p interaction. Clearly, colliding neutron beams could improve our knowledge of the n-n interaction once and for all. It seems incredible that in the last ten years no serious effort has been directed to such a fundamental interaction as that of the neutron-neutron system at low energies.[/ p

Slobodrian, R. J.

13

Improved deuteron elastic breakup energy dependence via the continuum-discretized coupled-channels method  

SciTech Connect

Experimental elastic-scattering angular distributions for deuteron interaction with {sup 63}Cu and {sup 93}Nb targets are compared with calculations performed within the continuum-discretized coupled-channels (CDCC) method, in which coupling to breakup channels is explicitly taken into account. The calculated elastic breakup cross sections are compared with the predictions of an empirical parametrization for a wide range of deuteron incident energies. The good agreement between the calculations and the systematics at the energies where data are available indicates that the CDCC method permits a useful assessment of empirical parametrizations and provides useful guidance for the extrapolation of these parametrizations beyond the energies formerly considered.

Avrigeanu, M.; Moro, A. M. ['Horia Hulubei' National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, R-077125 Bucharest-Magurele (Romania); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain)

2010-09-15

14

Neutron Beams from Deuteron Breakup at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory  

SciTech Connect

Accelerator-based neutron sources offer many advantages, in particular tunability of the neutron beam in energy and width to match the needs of the application. Using a recently constructed neutron beam line at the 88-Inch Cyclotron at LBNL, tunable high-intensity sources of quasi-monoenergetic and broad spectrum neutrons from deuteron breakup are under development for a variety of applications.

McMahan, M.A.; Ahle, L.; Bleuel, D.L.; Bernstein, L.; Braquest, B.R.; Cerny, J.; Heilbronn, L.H.; Jewett, C.C.; Thompson, I.; Wilson, B.

2007-07-31

15

Spin observables in the three-body break-up process near the quasi-free limit in deuteron–deuteron scattering  

NASA Astrophysics Data System (ADS)

We have studied spin observables in the three-body break-up reaction in deuteron–deuteron scattering in the phase-space regime that corresponds to the quasi-free deuteron–proton scattering process with the neutron as spectator. The data are compared to measurements of the elastic deuteron–proton scattering process and state-of-the-art Faddeev calculations. The results for iT11 and T22 for the quasi-free scattering data agree very well with previously published elastic-scattering data. A significant discrepancy is found for T20, which could point to a break-down of the quasi-free assumption.

Ramazani-Moghaddam-Arani, A.; Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacher, A. D.; Bailey, C. D.; Biegun, A.; Eslami-Kalantari, M.; Gašpari?, I.; Joulaeizadeh, L.; Kalantar-Nayestanaki, N.; Kistryn, St.; Kozela, A.; Mardanpour, H.; Messchendorp, J. G.; Micherdzinska, A. M.; Moeini, H.; Shende, S. V.; Stephan, E.; Stephenson, E. J.; Sworst, R.

2013-10-01

16

Characterization of a Tunable Quasi-Monoenergetic Neutron Beamfrom Deuteron Breakup  

SciTech Connect

A neutron irradiation facility is being developed at the88-Inch Cyclotron at Lawrence Berkeley National Laboratory for thepurposes of measuring neutron reaction cross sections on radioactivetargets and for radiation effects testing. Applications are of benefit tostockpile stewardship, nuclear astrophysics, next generation advancedfuel reactors, and cosmic radiation biology and electronics in space. Thefacility will supply a tunable, quasi-monoenergetic neutron beam in therange of 10-30 MeV or a white neutron source, produced by deuteronbreakup reactions on thin and thick targets, respectively. Because thedeuteron breakup reaction has not been well studied at intermediateincident deuteron energies, above the target Coulomb barrier and below 56MeV, a detailed characterization was necessary of the neutron spectraproduced by thin targets.Neutron time of flight (TOF) methods have beenused to measure the neutron spectra produced on thin targets of low-Z(titanium) and high-Z (tantalum) materials at incident deuteron energiesof 20 MeV and 29 MeV at 0 deg. Breakup neutrons at both energies fromlow-Z targets appear to peak at roughly half of the available kineticenergy, while neutrons from high-Z interactions peak somewhat lower inenergy, owing to the increased proton energy due to breakup within theCoulomb field. Furthermore, neutron spectra appear narrower for high-Ztargets. These centroids are consistent with recent preliminary protonenergy measurements using silicon telescope detectors conducted at LBNL,though there is a notable discrepancy with spectral widths.

Bleuel, D.L.; McMahan, M.A.; Ahle, L.; Barquest, B.R.; Cerny, J.; Heilbronn, L.H.; Jewett, C.C.

2006-12-14

17

Scattering length measurements from radiative pion capture and neutron-deuteron breakup  

SciTech Connect

The neutron-neutron and neutron-proton {sup 1}S{sub 0} scattering lengths a{sub nn} and a{sub np}, respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from two body reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a{sub nn} from the two-body {pi}{sup {minus}}-d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given.

Gibson, B.F. [Los Alamos National Lab., NM (United States); Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Universities Nuclear Lab., Durham, NC (United States); Carman, T.S. [Lawrence Livermore National Lab., CA (United States)] [and others

1997-07-01

18

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

NASA Astrophysics Data System (ADS)

Precise and large sets of cross sections for the 1H(d, pp)n and 2H(p, pp)n breakup reactions were measured at 130 deuteron and 190 MeV proton beam energies with the use of detectors which covered almost the full phase space. The results are compared with various theoretical approaches which model the 3N system dynamics. The calculations are based on different 2N potentials which can be combined with models of the three-nucleon force (3NF). The differential cross sections appear to be a very sensitive tool for testing the interaction models and allow to search for various ingredients of the dynamics, not only the 3NF but also the Coulomb interaction and relativistic effects which are relatively new achievements of the theory.

Ciepa?, Izabela; K?os, Barbara; 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.; Skibi?ski, R.; Sworst, R.; Urban, J.; Wita?a, H.; Wro?ska, A.; Zejma, J.

2012-12-01

19

Increase in |SL| induced by channel coupling: The case of deuteron breakup  

NASA Astrophysics Data System (ADS)

For deuteron scattering from 58Ni at laboratory energies of 56, 79, and 120 MeV, we study the dynamic polarization potentials (DPPs) induced by S-wave and D-wave breakup (BU), separately and together, in order to gain insight into the nature of the DPP as well as a counterintuitive property: the existence of L values for which the BU coupling increases |SL|, a ‘wrong-way’ effect. The effect is associated with the existence of emissive regions in the imaginary DPP, suggesting a connection with the nonlocal nature of the DPP. The same relationship was previously found for 6Li scattering, indicating a generic effect bearing on the dynamics of nuclear reactions.

Mackintosh, R. S.; Pang, D. Y.

2012-10-01

20

Faddeev calculation for breakup neutron-deuteron scattering at 14.1 MeV lab energy  

NASA Astrophysics Data System (ADS)

A new computational method for solving nucleon-deuteron breakup scattering problem has been applied to study inelastic neutron-deuteron scattering in the framework of configuration-space Faddeev-Noyes-Noble-Merkuriev equations. This method is based on the spline-decomposition in angular variable and on a generalization of the Numerov method for hyperradius. The Merkuriev-Gignoux-Laverne approach has been generalized for arbitrary nucleon-nucleon potentials and arbitrary number of partial waves. Neutron-deuteron observables at the incident nucleon energy 14.1 MeV have been calculated using the charge-independent Argonne AV14 nucleon-nucleon potential. Results have been compared with those of other authors and with experimental nucleon-deuteron scattering data.

Suslov, Vladimir; Braun, Mikhail; Filikhin, Igor; Slaus, Ivo; Vlahovic, Branislav

2013-04-01

21

Measurement of the Reaction {sup 2}H(e,e{sup '}) at 180 deg. Close to the Deuteron Breakup Threshold  

SciTech Connect

Inclusive inelastic electron scattering off the deuteron under 180 deg. has been studied at the S-DALINAC close to the breakup threshold at momentum transfers q=0.27 fm{sup -1} and 0.74 fm{sup -1} with good energy resolution sufficient to map in detail the spin flip M1 response, which governs the starting reaction pn{yields}d{gamma} of big-bang nucleosynthesis over most of the relevant temperature region. Results from potential model calculations and (for q=0.27 fm{sup -1}) from pionless nuclear effective field theory are in excellent agreement with the data.

Ryezayeva, N.; Burda, O.; Byelikov, A.; Chernykh, M.; Enders, J.; Kalmykov, Y.; Neumann-Cosel, P. von; Poltoratska, I.; Pysmenetska, I.; Rathi, S.; Richter, A.; Schrieder, G.; Shevchenko, A.; Yevetska, O. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Arenhoevel, H. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Griesshammer, H. W. [Center for Nuclear Studies, Department of Physics, George Washington University, Washington, D.C. 20052 (United States); Oezel, B. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Science and Art Faculty, Cukurova University, 01330 Adana (Turkey); Rangacharyulu, C. [Department of Physics, University of Saskatchewan, Saskatoon, S7N 5E2 (Canada)

2008-05-02

22

Measurement of the reaction 2H(e,e') at 180 degrees close to the deuteron breakup threshold.  

PubMed

Inclusive inelastic electron scattering off the deuteron under 180 degrees has been studied at the S-DALINAC close to the breakup threshold at momentum transfers q=0.27 fm;{-1} and 0.74 fm;{-1} with good energy resolution sufficient to map in detail the spin flip M1 response, which governs the starting reaction pn-->dgamma of big-bang nucleosynthesis over most of the relevant temperature region. Results from potential model calculations and (for q=0.27 fm;{-1}) from pionless nuclear effective field theory are in excellent agreement with the data. PMID:18518283

Ryezayeva, N; Arenhövel, H; Burda, O; Byelikov, A; Chernykh, M; Enders, J; Griesshammer, H W; Kalmykov, Y; von Neumann-Cosel, P; Ozel, B; Poltoratska, I; Pysmenetska, I; Rangacharyulu, C; Rathi, S; Richter, A; Schrieder, G; Shevchenko, A; Yevetska, O

2008-04-28

23

Measurement of the neutron-induced deuteron breakup reaction cross-section between 5 and 25 MeV  

NASA Astrophysics Data System (ADS)

This article presents a full program devoted to the calculation and the measurement of the neutron-induced deuteron break-up reaction cross-section between 5 and 10 MeV, and between 20 and 25 MeV. Measurements are compared with theoretical calculations based on the solution of the Faddeev equations for a realistic nuclear Hamiltonian. The experiments were performed at the Tandem 7 MV accelerator at CEA, DAM, DIF, France. The measurements were carried out with a C6D6 detector as active deuterium target located at the center of a 4? neutron counter (see C. Varignon et al., Nucl. Instrum. Methods B 248, 329 (2006)) which allows to count the two neutrons emitted in the 2H(n, 2n)p reaction. Comparisons of the new data and calculations are made with the existing data as well as the CENDL2, JENDL3.3 and ENDF/B-VII evaluations.

Laborie, J.-M.; Ledoux, X.; Varignon, C.; Lazauskas, R.; Morillon, B.; Bélier, G.

2012-06-01

24

Nucleon-Deuteron Breakup Differential Cross Sections Derived from the Quark-Model NN Interaction  

NASA Astrophysics Data System (ADS)

The nd and pd breakup differential cross sections for E N ? 65 MeV are examined using the energy-independent quark-model nucleon-nucleon interaction fss2. The Coulomb effect is incorporated by the sharp cut-off Coulomb force, acting between quarks, without the phase-shift renormalization for the breakup amplitudes. Our model yields the results very similar to the meson-exchange potentials, including disagreement for some specific kinematical configurations. This includes the notorious space star anomaly of the nd and pd scattering at E N = 13 MeV. The KVI data for the breakup differential cross sections of E d = 130 MeV dp scattering are reasonably reproduced by taking the Coulomb cut-off radius ? = 16 fm.

Fujiwara, Y.; Fukukawa, K.

2013-03-01

25

Deuteron breakup at 2. 1 and 1. 25 GeV  

SciTech Connect

Inclusive differential cross section and analyzing power T/sub 20/ in A(d,p)X at 2.1 GeV and for protons at 0/sup 0/ are presented for the targets /sup 1/H, /sup 4/He, /sup 12/C, Ti, and Sn. In addition, data for /sup 1/H at 1.25 GeV are also shown. For all targets the cross-section data show a similarity in shape when plotted as a function of q, the proton momentum in the deuteron frame, each target exhibiting a shoulder near q = 0.30--0.35 GeV/c. Likewise, T/sub 20/ values are largely independent of the target's A value. When compared with higher-energy data for /sup 12/C(d,p)X, the new results establish the universality of the shoulder over the energy range 1.25--7.4 GeV, as well as the energy independence of T/sub 20/. The /sup 1/H(d,p)X data are compared with the results of a nonrelativistic calculation of the six lowest-order graphs of the process using elastic, on-shell NN amplitudes and the Paris NN potential deuteron wave function. The calculated cross sections have no shoulder at either of the two energies of this experiment; the observed behavior of T/sub 20/ is reproduced qualitatively only. Comparisons with /sup 2/H(p,2p) and /sup 2/H(e,e'p) data are made and various possible origins for the anomalous shoulder discussed, including ..pi.. rescattering, ..delta.. excitation, and a six quark component in the deuteron.

Punjabi, V.; Perdrisat, C.F.; Ulmer, P.; Lyndon, C.; Yonnet, J.; Beurtey, R.; Boivin, M.; Plouin, F.; Didelez, J.P.; Frascaria, R.; and others

1989-02-01

26

Vector and tensor analyzing powers in deuteron-proton breakup at 130 MeV  

SciTech Connect

High-precision data for vector and tensor analyzing powers for the {sup 1}H(d-vector,pp)n reaction at a 130-MeV deuteron beam energy have been measured over a large part of the phase space. Theoretical predictions based on various approaches to describe the three nucleon (3N) system reproduce very well the vector analyzing power data and no three-nucleon force effect is observed for these observables. Tensor analyzing powers are also very well reproduced by calculations in almost the whole studied region, but locally certain discrepancies are observed. For A{sub xy} such discrepancies usually appear, or are enhanced, when model 3N forces, TM99 or Urbana, are included. Problems of all theoretical approaches with describing A{sub xx} and A{sub yy} are limited to very small kinematical regions, usually characterized by the lowest energy of the relative motion of the two protons.

Stephan, E.; Biegun, A.; Klos, B.; Micherdzinska, A.; Zipper, W. [Institute of Physics, University of Silesia, PL-40007 Katowice (Poland); Kistryn, St.; Sworst, R.; Bodek, K.; Ciepal, I.; Golak, J.; Skibinski, R.; Witala, H.; Wronska, A.; Zejma, J. [Institute of Physics, Jagiellonian University, PL-30059 Krakow (Poland); Deltuva, A. [Centro de Fisica Nuclear da Universidade de Lisboa, P-1649-003 Lisboa (Portugal); Epelbaum, E. [Institute fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Fonseca, A. C. [Centro de Fisica Nuclear, Universidade de Lisboa, P-1649-003 Lisboa (Portugal); Kalantar-Nayestanaki, N.; Kis, M.; Mahjour-Shafiei, M. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747 AA Groningen (Netherlands)

2010-07-15

27

The Proton-Deuteron Break-Up Process in a Three-Dimensional Approach  

NASA Astrophysics Data System (ADS)

The pd break-up amplitude in the Faddeev scheme is calculated by employing a three-dimensional method without partial wave decomposition (PWD). In the first step and in view of higher energies only the leading term is evaluated and this for the process d(p,n)pp. A comparison with the results based on PWD reveals discrepancies in the cross section around 200 MeV. This indicates the onset of a limitation of the partial wave scheme. Also around 200 MeV relativistic effects are clearly visible and the use of relativistic kinematics shifts the cross section peak to where the experimental peak is located. The theoretical peak height, however, is wrong and calls first of all for the inclusion of rescattering terms, which are shown to be important in a nonrelativistic full Faddeev calculation in PWD.

Fachruddin, Imam; Elster, Charlotte; Glöckle, Walter

28

Similarity between the Primary and Secondary Air-Assisted Liquid Jet Breakup Mechanisms  

Microsoft Academic Search

We report an ultrafast synchrotron x-ray phase-contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. There exist great similarities between the primary (jet) and the secondary (drop) breakup, and in the primary breakup on different length scales. A transition from a ligament- to a membrane-mediated breakup is identified around an effective Weber number We'˜13. This

Yujie Wang; Kyoung-Su Im; Kamel Fezzaa

2008-01-01

29

Polarization observables in hard rescattering mechanism of deuteron photodisintegration  

NASA Astrophysics Data System (ADS)

Polarization properties of high energy photodisintegration of the deuteron are studied within the framework of the hard rescattering mechanism (HRM). In HRM, a quark of one nucleon knocked-out by the incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with high relative momentum. Summation of all relevant quark rescattering amplitudes allows us to express the scattering amplitude of the reaction through the convolution of a hard photon-quark interaction vertex, the large angle p-n scattering amplitude and the low momentum deuteron wave function. Within HRM, it is demonstrated that the polarization observables in hard photodisintegration of the deuteron can be expressed through the five helicity amplitudes of NN scattering at high momentum transfer. At 90° CM scattering HRM predicts the dominance of the isovector channel of hard pn rescattering, and it explains the observed smallness of induced, Py and transfered, Cx polarizations without invoking the argument of helicity conservation. Namely, HRM predicts that Py and Cx are proportional to the ?5 helicity amplitude which vanishes at ?cm=90° due to symmetry reasons. HRM predicts also a nonzero value for Cz in the helicity-conserving regime and a positive ? asymmetry which is related to the dominance of the isovector channel in the hard reinteraction. We extend our calculations to the region where large polarization effects are observed in pp scattering as well as give predictions for angular dependences.

Sargsian, Misak M.

2004-05-01

30

A PROPOSAL TO MEASURE THE CROSS SECTION OF THE SPACE STAR IN NEUTRON-DEUTERON BREAKUP IN A RECOIL GEOMETRY SETUP  

SciTech Connect

Nucleon-deuteron (Nd) breakup is an important tool for obtaining a better understanding of three-nucleon (3N) dynamics and for developing meson exchange descriptions of nuclear systems. The kinematics of the nd breakup reaction enable observables to be studied in a variety of exit-channel configurations that show sensitivity to realistic nucleon-nucleon (NN) potential models and three-nucleon force (3NF) models. Rigorous 3N calculations give very good descriptions of most 3N reaction data. However, there are still some serious discrepancies between data and theory. The largest discrepancy observed between theory and data for nd breakup is for the cross section for the space-star configuration. This discrepancy is known as the “Space star Anomaly”. Several experimental groups have obtained results consistent with the “Space Star Anomaly”, but it is important to note that they all used essentially the same experimental setup and so their experimental results are subject to the same systematic errors. We propose to measure the space-star cross-section at the Triangle Universities Nuclear Laboratory (TUNL) using an experimental technique that is significantly different from the one used in previous breakup experiments. This technique has been used by a research group from the University of Bonn to measure the neutron-neutron scattering length. There are three possible scenarios for the outcome of this work: 1) the new data are consistent with previous measurements; 2) the new data are not in agreement with previous measurements, but are in agreement with theory; and 3) the new data are not in agreement with either theory or previous measurements. Any one of the three scenarios will provide valuable insight on the Space Star Anomaly.

Benjamin J. Crowe III

2009-09-30

31

Similarity between the Primary and Secondary Air-Assisted Liquid Jet Breakup Mechanisms  

NASA Astrophysics Data System (ADS)

We report an ultrafast synchrotron x-ray phase-contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. There exist great similarities between the primary (jet) and the secondary (drop) breakup, and in the primary breakup on different length scales. A transition from a ligament- to a membrane-mediated breakup is identified around an effective Weber number We'˜13. This observation reveals the critical role an effective Weber number plays in determining the atomization process and strongly supports the cascade breakup model.

Wang, Yujie; Im, Kyoung-Su; Fezzaa, Kamel

2008-04-01

32

Similarity between the primary and secondary air-assisted liquid jet breakup mechanisms.  

PubMed

We report an ultrafast synchrotron x-ray phase-contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. There exist great similarities between the primary (jet) and the secondary (drop) breakup, and in the primary breakup on different length scales. A transition from a ligament- to a membrane-mediated breakup is identified around an effective Weber number We' approximately 13. This observation reveals the critical role an effective Weber number plays in determining the atomization process and strongly supports the cascade breakup model. PMID:18518113

Wang, Yujie; Im, Kyoung-Su; Fezzaa, Kamel

2008-04-18

33

Mechanisms and systematics of breakup in reactions of {sup 9}Be at near-barrier energies  

SciTech Connect

Below-barrier no-capture breakup measurements of the weakly bound {sup 9}Be nucleus, incident on targets ranging in atomic number from 62 to 83, have been carried out using a large-area high-resolution back-angle detector array. It is shown that the three-body reconstructed reaction Q-value and relative energy of the breakup fragments together reveal the full dynamics of the breakup mechanism, identifying all physical processes that lead to the breakup of the projectile-like nucleus. Contrasting with the simple expectation of direct breakup into the most energetically favored clusters, the data show that breakup following n-transfer dominates the total breakup yield. Breakup from long-lived states in the projectile-like nucleus, which on the reaction time scale may be considered stable, has been isolated from the prompt breakup yield. It has been shown that the prompt breakup probability essentially depends on the surface separation of the interacting nuclei. The measured prompt breakup probability functions for each target have been used together with a classical trajectory model to predict the above-barrier suppression of complete fusion. The suppression factor, expressed as the fraction of incomplete fusion, is nearly independent of target charge.

Rafiei, R.; Rietz, R. du; Luong, D. H.; Hinde, D. J.; Dasgupta, M.; Evers, M.; Diaz-Torres, A. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2010-02-15

34

Spin structure of the "Forward" nucleon charge-exchange reaction n + p ? p + n and the deuteron charge-exchange breakup  

NASA Astrophysics Data System (ADS)

The structure of the nucleon charge-exchange process n + p ? p + n is investigated basing on the isotopic invariance of the nucleon-nucleon scattering. Using the operator of permutation of the spin projections of the neutron and proton, the connection between the spin matrices, describing the amplitude of the nucleon charge-exchange process at zero angle and the amplitude of the elastic scattering of the neutron on the proton in the "backward" direction, has been considered. Due to the optical theorem, the spin-independent part of the differential cross section of the process n + p ? p + n at zero angle for unpolarized particles is expressed through the difference of total cross sections of unpolarized proton-proton and neutron-proton scattering. Meantime, the spin-dependent part of this cross section is proportional to the differential cross section of the deuteron charge-exchange breakup d + p ? ( pp) + n at zero angle at the deuteron momentum k d = 2 k n ( k n is the initial neutron momentum). Analysis shows that, assuming the real part of the spin-independent term of the "forward" amplitude of the process n + p ? p + n to be smaller or of the same order as compared with the imaginary part, in the wide range of neutron laboratory momenta k n > 700 MeV/ c the main contribution into the differential cross section of the process n + p ? p + n at zero angle is provided namely by the spin-dependent term.

Lyuboshitz, V. L.; Lyuboshitz, V. V.

2011-02-01

35

Droplet Breakup Mechanisms in Air-blast Atomizers  

NASA Astrophysics Data System (ADS)

Atomization processes are encountered in many natural and man-made phenomena. Examples are pollen release by plants, human cough or sneeze, engine fuel injectors, spray paint and many more. The physics governing the atomization of liquids is important in understanding and utilizing atomization processes in both natural and industrial processes. We have observed the governing physics of droplet breakup in an air-blast water atomizer using a high magnification, high speed, and high resolution LASER imaging technique. The droplet breakup mechanisms are investigated in three major categories. First, the liquid drops are flattened to form an oblate ellipsoid (lenticular deformation). Subsequent deformation depends on the magnitude of the internal forces relative to external forces. The ellipsoid is converted into a torus that becomes stretched and disintegrates into smaller drops. Second, the drops become elongated to form a long cylindrical thread or ligament that break up into smaller drops (Cigar-shaped deformation). Third, local deformation on the drop surface creates bulges and protuberances that eventually detach themselves from the parent drop to form smaller drops.

Aliabadi, Amir Abbas; Taghavi, Seyed Mohammad; Lim, Kelly

2011-11-01

36

Spin structure of the 'Forward' nucleon charge-exchange reaction n + p {yields} p + n and the deuteron charge-exchange breakup  

SciTech Connect

The structure of the nucleon charge-exchange process n + p {yields} p + n is investigated basing on the isotopic invariance of the nucleon-nucleon scattering. Using the operator of permutation of the spin projections of the neutron and proton, the connection between the spin matrices, describing the amplitude of the nucleon charge-exchange process at zero angle and the amplitude of the elastic scattering of the neutron on the proton in the 'backward' direction, has been considered. Due to the optical theorem, the spin-independent part of the differential cross section of the process n + p {yields} p + n at zero angle for unpolarized particles is expressed through the difference of total cross sections of unpolarized proton-proton and neutron-proton scattering. Meantime, the spin-dependent part of this cross section is proportional to the differential cross section of the deuteron charge-exchange breakup d + p {yields} (pp) + n at zero angle at the deuteron momentum k{sub d} = 2 k{sub n} (k{sub n} is the initial neutron momentum). Analysis shows that, assuming the real part of the spin-independent term of the 'forward' amplitude of the process n + p {yields} p + n to be smaller or of the same order as compared with the imaginary part, in the wide range of neutron laboratory momenta k{sub n} > 700 MeV/c the main contribution into the differential cross section of the process n + p {yields} p + n at zero angle is provided namely by the spin-dependent term.

Lyuboshitz, V. L., E-mail: Valery.Lyuboshitz@jinr.ru; Lyuboshitz, V. V. [Joint Institute for Nuclear Research (Russian Federation)

2011-02-15

37

Deuteron breakup pd->(pp){sub s}n with forward emission of a fast {sup 1}S{sub 0} diproton  

SciTech Connect

The deuteron breakup reaction pd->(pp){sub s}n, where (pp){sub s} is a fast proton pair emitted in forward direction with small excitation energy E{sub pp}<3 MeV, has been studied at proton beam energies of 0.5-2.0 GeV using the ANKE spectrometer at COSY-Juelich. The differential c.m. cross sections are measured in complete kinematics and provide angular distributions of the neutron emission angle in the range theta{sub n}=168 deg. - 180 deg., the dependence on beam energy at theta{sub n}=180 deg., angular distributions of the direction of the proton in the pp rest frame, and distributions of the excitation energy E{sub pp} of the proton pair. The obtained data are analyzed on the basis of theoretical models previously developed for the pd->dp process in a similar kinematics and properly modified for the diproton channel in pd->(pp){sub s}n. It is shown that the measured observables are highly sensitive to the short-range part of the nucleon-nucleon interaction.

Dymov, S.; Yaschenko, S. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Komarov, V.; Macharashvili, G.; Uzikov, Yu.; Azarian, T.; Kulikov, A.; Kurbatov, V.; Merzliakov, S.; Zalikhanov, B.; Zhuravlev, N. [Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Imambekov, O. [Laboratory of Nuclear Problems, JINR, RU-141980 Dubna (Russian Federation); Kazakh National University, KZ-050038, Almaty (Kazakhstan); Buescher, M.; Hartmann, M.; Hejny, V.; Kacharava, A.; Nekipelov, M.; Ohm, H.; Rathmann, F.; Seyfarth, H. [Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany)

2010-04-15

38

Mechanism of flow-induced biomolecular and colloidal aggregate breakup  

NASA Astrophysics Data System (ADS)

The drift-diffusion equation is first solved analytically for the dissociation rate and lifetime of a biomolecular or colloidal dimer bonded by realistic intermolecular potentials, under shear flow. Then we show using rigidity percolation concepts that the lifetime of a generic cluster formed under shear is controlled by the typical lifetime of a single bond in its interior. The latter, however, is also affected by collective stress transmission from other bonds in the aggregate, which we account for by introducing a semiempirical, analytical stress transmission efficiency 0???1 calibrated on several simulation data sets. We show that aggregate breakup is a thermally activated process in which the activation energy is controlled by the interplay between intermolecular forces and the shear drift. The collective contribution to the overall shear drift term is dominant for large enough fractal aggregates, while surface erosion prevails for small and compact aggregates. The crossover between the two regimes occurs when ?N?2, where both the number of particles in the cluster N and the stress transmission efficiency ? depend on the aggregate structure through the fractal dimension df. The analytical framework for the aggregate breakup rate is in quantitative agreement with experiments and can be used in future studies in the population balance modeling of colloidal and protein aggregation.

Conchúir, Breanndán Ó.; Zaccone, Alessio

2013-03-01

39

Nuclear-breakup mechanisms in the interaction of relativistic projectiles with heavy targets  

SciTech Connect

The breakup of a Au nucleus under bombardment with relativistic p, ..cap alpha.., and /sup 20/Ne has been investigated in an extensive, multi-detector study. The present discussion addresses some of the many aspects of the experimental results. A broad distribution of coincident fragment masses is observed, with the total fragment kinetic energy being higher than expected for a fission mechanism for total fragment mass less than or equal to 120. The formation of light fragments is shown to be inconsistent with a binary breakup mechanism, and a multi-fragment target breakup is suggested. In general, the results indicate a broad spectrum of violence in the collisions, from gentle, leading to the production of heavy spallation products and fission, to essentially explosive, leading to multi-fragment breakup into light mas products. These aspects of the reactions represent a late-stage breakup of the target residues and are positively correlated with the violence of the initial fast stage of the collision as measured by the charged particle multiplicity.

Steinberg, E.P.

1982-01-01

40

Mechanisms of free-surface breakup in vibration-induced liquid atomization  

NASA Astrophysics Data System (ADS)

The mechanisms of droplet formation that take place during vibration-induced drop atomization are investigated experimentally. Droplet ejection results from the breakup of transient liquid spikes that form following the localized collapse of free-surface waves. Breakup typically begins with capillary pinch-off of a droplet from the tip of the spike and can be followed by additional pinch-offs of satellite droplets if the corresponding capillary number is sufficiently small (e.g., in low-viscosity liquids). If the capillary number is increased (e.g., in viscous liquids), breakup first occurs near the base of the spike, with or without subsequent breakup of the detached, thread-like spike. The formation of these detached threads is governed by a breakup mechanism that is separated from the tip-dominated capillary pinch-off mechanism by an order of magnitude in terms of dimensionless driving frequency f*. The dependence of breakup time and unbroken spike length on fluid and driving parameters is established over a broad range of dimensionless driving frequencies (10-3=20, the droplet-ejection threshold becomes independent of dcirc (âc~4). This limit state is described by a scaling equivalent to that of Goodridge, Shi, and Lathrop [Phys. Rev. Lett. 76, 1824 (1996)] derived for the onset of droplet ejection from Faraday waves. It is shown in the present study that the acceleration threshold in this limit scales like ac~f4/3(?/?)1/3.

Vukasinovic, Bojan; Smith, Marc K.; Glezer, Ari

2007-01-01

41

Quantifying the thermo-mechanical impact of plume arrival on continental break-up  

NASA Astrophysics Data System (ADS)

The arrival of a plume head at Earth's continental lithosphere is often considered to be an important factor for continental break-up. However, the impact of plume impingement on strength and duration of a rift remains unclear. In this study, we quantify the mechanical and thermal influence of a plume (i.e. lithosphere erosion) on continental break-up. To do that we apply the three-dimensional numerical code SLIM3D that features realistic elasto-visco-plastic rheology. We model the thermo-mechanical response of a segment of Earth's lithosphere that is affected both by extension as well as plume-related lithosphere erosion in order to evaluate the influence on the overall force budget. We find that lithosphere erosion leads to a moderate lithospheric strength reduction of several TN/m. In a force-limited environment, however, this strength reduction may have strong influence on the timing of continental break-up, or it may even control whether continental break-up takes place at all. Additional reduction of the lithospheric strength is likely due to the massive emplacement of dikes that follows intensive melting within the plume head.

Brune, Sascha; Popov, Anton A.; Sobolev, Stephan V.

2013-09-01

42

Coulomb breakup mechanism of neutron-halo nuclei in a time-dependent method  

Microsoft Academic Search

The mechanism of the Coulomb breakup reactions of the nuclei with neutron-halo structure is investigated in detail. A time-dependent Schrödinger equation for the halo neutron is numerically solved by treating the Coulomb field of a target as an external field. The momentum distribution and the post-acceleration effect of the final fragments are discussed in a fully quantum mechanical way to

T. Kido; K. Yabana; Y. Suzuki

1996-01-01

43

Interplay between valence and core excitation mechanisms in the breakup of halo nuclei.  

PubMed

The phenomenon of core excitation in the breakup of a two-body halo nucleus is investigated. We show that this effect plays a significant role in the reaction dynamics and, furthermore, its interference with the valence excitation mechanism has sizable and measurable effects on the breakup angular distributions. These effects have been studied in the resonant breakup of (11)Be on a carbon target, populating the resonances at 1.78 MeV (5/2(+)) and 3.41 MeV (3/2(+)). The calculations have been performed using a recent extension of the distorted-wave Born approximation method, which takes into account the effect of core excitation in both the structure of the halo nucleus and in the reaction mechanism. The calculated angular distributions have been compared with the available data [Fukuda et al., Phys. Rev. C 70, 054606 (2004).]. Although each of these resonances is dominated by one of the two considered mechanisms, the angular patterns of these resonances depend in a very delicate way on the interference between them. This is the first clear evidence of this effect but the phenomenon is likely to occur in other similar reactions. PMID:23368187

Moro, A M; Lay, J A

2012-12-05

44

Interplay Between Valence and Core Excitation Mechanisms in the Breakup of Halo Nuclei  

NASA Astrophysics Data System (ADS)

The phenomenon of core excitation in the breakup of a two-body halo nucleus is investigated. We show that this effect plays a significant role in the reaction dynamics and, furthermore, its interference with the valence excitation mechanism has sizable and measurable effects on the breakup angular distributions. These effects have been studied in the resonant breakup of Be11 on a carbon target, populating the resonances at 1.78 MeV (5/2+) and 3.41 MeV (3/2+). The calculations have been performed using a recent extension of the distorted-wave Born approximation method, which takes into account the effect of core excitation in both the structure of the halo nucleus and in the reaction mechanism. The calculated angular distributions have been compared with the available data [Fukuda , Phys. Rev. C 70, 054606 (2004).]. Although each of these resonances is dominated by one of the two considered mechanisms, the angular patterns of these resonances depend in a very delicate way on the interference between them. This is the first clear evidence of this effect but the phenomenon is likely to occur in other similar reactions.

Moro, A. M.; Lay, J. A.

2012-12-01

45

Characterization of jet breakup mechanisms observed from simulant experiments of molten fuel penetrating coolant. Technical progress report, FY 1992  

SciTech Connect

The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.

Jones, B.G.

1992-08-01

46

Breakup Reactions of Halo Nuclei  

SciTech Connect

Different reaction mechanisms of breakup reactions are discussed and the microscopic reaction model for two-neutron halo dissociation is presented. Some examples of halo breakup in reactions with electrons, nucleons, and nuclei are given.

Ershov, S.N. [Bogolyubov Laboratory of Theoretical Physics, Joint Institute of Nuclear Research, Dubna, Moscow oblast, 141980 (Russian Federation)

2004-10-01

47

Fracture Mechanical Analysis of Frost Wedging in Ice Shelves as Break-Up Mechanism  

NASA Astrophysics Data System (ADS)

Disintegration events in ice shelves have been the subject of extensive investigations in the past years, however comprehensive explanations applicable to a majority of events are still missing. A popular assumption made by Scambos et al. (2000) [1] links disintegration events to a general thinning of the ice shelf in conjunction with growing melt-water ponds leading to hydro fractures. This explanation seems reasonable for break-up events that happened in Antarctic summers. Large parts of the Wilkins Ice Shelf, however broke-up in fall and winter periods. Therefore, the aim of the present study is to analyse the possibility of frost wedging of water filled surface crevasses in an ice shelf as a source of break-up events. Configurational forces are used to assess crack criticality. The simulations are performed on a 2-dimensional single crack with a mode-I type load, body forces and additional crack-face pressure due to freezing of the water. Depth-dependent density profiles are considered. The relevant parameters, Young's modulus, Poisson's ratio and external loading are obtained from literature, remote sensing data analysis and modelling of the ice dynamics. The investigation is performed using the finite element software COMSOL. The simulations show that in comparison to water filled crevasses without ice, thin layers of frozen water may lead to a decreasing criticality at the crack tip as long as the ice 'bridge' is allowed to take tensile loads. An increasing crack criticality can be seen for thicker layers of ice. The results are compared to findings from previous finite element analyses of dry and water filled cracks as presented in Plate et al. (2012) [2]. [1] Scambos, T., Hulbe, C., Fahnestock, M., & Bohlander, J. (2000). The link between climate warming and break-up of ice shelves in the Antarctic Peninsula. Journal of Glaciology, 46(154), 516-530. [2] Plate, C., Müller, R., Humbert, A., & Gross, D. (2012). Evaluation of the criticality of cracks in ice shelves using finite element simulations. The Cryosphere, 6(5), 973-984.

Plate, Carolin; Humbert, Angelika; Gross, Dietmar; Müller, Ralf

2013-04-01

48

Mechanisms of Coulomb breakup reactions of 6He and 11Li  

NASA Astrophysics Data System (ADS)

We investigate the three-body Coulomb breakup reactions of two-neutron halo nuclei and discuss the effect of binary subsystem correlations such as the of core-n and n-n. Furthermore, we calculate the invariant mass spectra. It is found that the final-state interactions of core-n and n-n binary subsystems dominantly determine the observed structures of the breakup cross sections, such as the low-lying enhancements.

Kikuchi, Y.; Myo, T.; Kat?, K.; Ikeda, K.

2013-04-01

49

Coulomb breakup of 6Li into ?+d in the field of a 208Pb ion  

NASA Astrophysics Data System (ADS)

The triple differential cross section of the 208Pb(6Li,?d)208Pb quasielastic breakup is calculated at a collision energy of 156 MeV and a scattering angle range of 2?-6?. We fit the parameters of the Woods-Saxon potential using the experimental ?-d phase shifts for different states to describe the relative motion of the ? particle and deuteron. To check the validity of the two particle approach for the ?-d system, we apply a potential model to describe the 2H(?,?)6Li radiative capture. We calculate the Coulomb breakup using the semiclassical method while an estimation of the nuclear breakup is made on the basis of the diffraction theory. A comparison of our calculation with the experimental data of Kiener [Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.44.2195 44, 2195 (1991)] gives evidence for the dominance of the Coulomb dissociation mechanism and the contribution of nuclear distortion, but is essentially smaller than the value reported by Hammache [Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.82.065803 82, 065803 (2010)]. The results of our calculation for the triple cross sections (contributed by the Coulomb and nuclear mechanisms) of the 6Li breakup hint toward a forward-backward asymmetry in the relative direction of the ? particle and deuteron emission, especially at smaller scattering angles, in the 6Li center-of-mass (c.m.) system.

Irgaziev, B. F.; Nabi, Jameel-Un; Khan, Darwaish

2011-12-01

50

Reaction Mechanisms in HELIUM3 Induced Projectile Breakup: a Study of Breakup-Related Processes Induced by HELIUM3 Particles at E(HELIUM3) = 52 Mev  

Microsoft Academic Search

Inclusive proton and deuteron spectra from He induced reactions on ('12)C, ('28)Si and ('58)Ni have been studied. Each spectrum contains a continuum part that may be separated into a broad bump, centered around beam velocity energies at forward angles, and an exponential tail. The properties of each of these components have been investigated as function of outgoing particle, detection angle

Emile Hubertus Leonardus Aarts

1984-01-01

51

Inclusive quasielastic deuteron production  

Microsoft Academic Search

It is argued that the measurement of the inclusive quasielastic deuteron production cross section coming from intermediate energy nucleus bombarding nuclei is of considerable theoretical interest. The inclusivity of the measurement leads to simplifications and allows a quasiclassical description to be used. A simple, heuristic, and quantum mechanically well defined formula is derived which includes for the first time a

E. A. Remler; A. P. Sathe

1978-01-01

52

The Breakup  

ERIC Educational Resources Information Center

|This article reports on the breakup between Texas Southmost College (TSC) and the upper-division University of Texas at Brownsville (UTB). The split marks the official end of an unusual 20-year partnership between TSC and the University of Texas System that, for the first time, ushered four-year university education into overwhelmingly Latino…

Lum, Lydia

2011-01-01

53

Breakup mechanisms of electrostatic atomization of corn oil and diesel fuel  

NASA Astrophysics Data System (ADS)

High-viscosity organic oils may be considered as an alternative to the ordinary diesel fuel. These organic oils and the diesel fuel are all Newtonian liquids; however, viscosity values of the organic oils are more than 20 times higher than that of the diesel fuel. In the present work, the electrostatic atomization of corn oil jets is studied and compared to the electrostatic atomization of diesel fuel jets. The experimental data revealed that in addition to the varicose breakup of straight jets, bending modes set in and grow in conjunction with the varicose undulations. Bending instability, kindred to the aerodynamically-driven bending instability of high-speed liquid jets moving in air, and to the electrically-driven bending instability of polymer jets in electrospinning, is significantly more pronounced in the case of the highly-viscous corn oil jets than in diesel jets. The experimental results are interpreted using the theory of bending instability developed previously for electrospinning.

Malkawi, G.; Yarin, A. L.; Mashayek, F.

2010-09-01

54

Explosive break-up of Larsen Ice Shelf, Antarctica, by a meltwater-triggered iceberg capsize mechanism  

NASA Astrophysics Data System (ADS)

Two disintegration events leading to the loss of Larsen A and B ice shelves in 1995 and 2002, respectively, proceeded with extreme rapidity (order several days) and reduced integrated ice shelf to a jumble of small iceberg fragments. These events strongly correlate with warming regional climate and accumulation of surface melt water, supporting the hypothesis that meltwater induced propagation of pre-existing surface crevasses may have started ice-shelf fragmentation. What we address in this study is not the crevasse propagation process that triggers disintegration, but rather a mechanism that may sustain the ice-shelf break-up once it begins. The proposed mechanism involves the coherent capsize of narrow (less than thickness) ice-shelf fragments by rolling 90° in a direction toward the ice front. We envision such fragments as being pieces of ice shelf liberated when two surface or basal crevasses oriented across the pre break-up flow direction suddenly cleave the entire ice thickness, e.g., as a result of meltwater crevasse wedging. Fragment capsize liberates gravitational potential energy and creates forces that wedge open ice-shelf rifts (void space containing the fragment). We speculate that the wedging forces so created may stimulate further fragmentation of the ice shelf and thereby contribute to its sudden disintegration. The process we propose is analagous to the overflow of a champagne bottle that has been opened after having been vigorously shaken. In the analogy, bubbles play the role of ice-shelf voids (rifts) that contain floating ice fragments that can capsize, and CO2 gas within the bubbles plays the role of capsizing ice fragments that create wedging forces tending to widen the rifts that contain them. Observational support for our proposed mechanism is provided by post-break-up MODIS (visible) satellite imagery that reveals formerly englacial debris exposed at the surface and small, blue-colored sub-pixel-sized icebergs that have rolled onto their sides.

Macayeal, D. R.; Hulbe, C. L.; Scambos, T. A.; Fahnestock, M. A.

2002-12-01

55

Espalhamento elastico de deuteron num sistema de tres corpos com interacao Coulombiana. (Elastic scattering of deuteron in three-body system with Coulomb interaction).  

National Technical Information Service (NTIS)

The three-body formalism with coulomb interaction proposed by Alt, Sandhas and Ziegelmann is used in the calculation of the elastic deuteron-nucleus differential cross section, when the total energy of the three-body system is below the deuteron break-up ...

M. H. P. Martins

1985-01-01

56

Low-energy deuteron-induced reactions on 93Nb  

NASA Astrophysics Data System (ADS)

The activation cross sections of (d,p), (d,2n), (d,2np+nd+t), (d,2n?), and (d,p?) reactions on 93Nb were measured in the energy range from 1 to 20 MeV using the stacked-foil technique. Then, within a simultaneous analysis of elastic scattering and reaction data, the available elastic-scattering data analysis was carried out in order to obtain the optical potential for reaction cross-section calculations. Particular attention was paid to the description of the breakup mechanism and direct reaction stripping and pick-up, followed by pre-equilibrium and compound-nucleus calculations. The measured cross sections as well as all available deuteron activation data of 93Nb were compared with results of local model calculations carried out using the codes fresco and stapre-h and both default and particular predictions of the code talys-1.4 and tendl-2012-evaluated data.

Avrigeanu, M.; Avrigeanu, V.; Bém, P.; Fischer, U.; Honusek, M.; Koning, A. J.; Mrázek, J.; Šime?ková, E.; Štefánik, M.; Závorka, L.

2013-07-01

57

Delta-Isobar Production in the Hard Photodisintegration of a Deuteron  

NASA Astrophysics Data System (ADS)

Hard photodisintegration of the deuteron in delta-isobar production channels is proposed as a useful process in identifying the quark structure of hadrons and of hadronic interactions at large momentum and energy transfer. The reactions are modeled using the hard re scattering model, HRM, following previous works on hard breakup of a nucleon nucleon (NN) system in light nuclei. Here,quantitative predictions through the HRM require the numerical input of fits of experimental NN hard elastic scattering cross sections. Because of the lack of data in hard NN scattering into ?-isobar channels, the cross section of the corresponding photodisintegration processes cannot be predicted in the same way. Instead, the corresponding NN scattering process is modeled through the quark interchange mechanism, QIM, leaving an unknown normalization parameter. The observables of interest are ratios of differential cross sections of ?-isobar production channels to NN breakup in deuteron photodisintegration. Both entries in these ratios are derived through the HRM and QIM so that normalization parameters cancel out and numerical predictions can be obtained. )

Granados, Carlos; Sargsian, Misak

2010-02-01

58

Bubble Breakup Caused by Shape Instabilities  

Microsoft Academic Search

The breakup of a bubble is the most intriguing phenomenon in the bubble dynamics to many fluid dynamics researcher. Bubble may break up due to different kinds of mechanisms. However due to the complexity of the system, no general analytical approachis available for studying this breakup phenomenon of a bubble. Hence numerical approach is taken in our current work to

Y.-H. Su; Z. C. Feng

1998-01-01

59

Free Fall Breakup of Large Drops  

Microsoft Academic Search

The breakup of large water drops during free fall is of importance to meteorologists. Theories of precipitation lean heavily on drop multiplication resulting from the shattering of large drops. An experiment is described in which the actual breakup of large drops is observed, and data obtained from which the mechanism of break may be inferred. Drops in the various stages

R. H. Magarvey; B. W. Taylor

1956-01-01

60

Effective radii of deuteron-induced reactions  

SciTech Connect

The continuum-discretized coupled-channels method (CDCC) for exclusive reactions and the eikonal reaction theory (ERT) as an extension of CDCC to inclusive reactions are applied to deuteron-induced reactions. The CDCC result reproduces experimental data on the reaction cross section for d+{sup 58}Ni scattering at 200 MeV/nucleon, and ERT provides data on the neutron-stripping cross section for inclusive {sup 7}Li(d,n) reaction at 40 MeV. For deuteron-induced reactions at 200 MeV/nucleon, target-dependence of the reaction, elastic-breakup, nucleon-stripping, nucleon-removal, and complete- and incomplete-fusion cross sections is clearly explained by simple formulas. Accuracy of the Glauber model is also investigated.

Hashimoto, Shintaro; Chiba, Satoshi [Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Yahiro, Masanobu; Ogata, Kazuyuki; Minomo, Kosho [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2011-05-15

61

Semiclassical theory of fusion and breakup reactions  

SciTech Connect

We discuss the use of the semiclassical approximation of Alder and Winther in the description of fusion and breakup reactions with weakly bound nuclei. A comparison with realistic CDCC calculations shows that the method leads to accurate predictions for the breakup cross section. We show how the method can be extended to fusion reactions and apply it to a schematic two-channel model, in which the breakup states are approximated by a single effective channel. The complete fusion cross section so evaluated compares very well with predictions of fully quantum mechanical coupled-channels calculations.

Canto, L. F.; Donangelo, R. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68528, 21941-972 Rio de Janeiro, RJ (Brazil); Marta, H. D. [Instituto de Fisica, Facultad de Ingenieria, C.C. 30, C.P. 11000, Montevideo (Uruguay)

2007-02-12

62

Probing Neutron Correlations through Nuclear Breakup  

SciTech Connect

The effect of initial correlations between nucleons on the nuclear breakup mechanism is studied. A quantum transport theory which extends the standard mean-field approach is developed to incorporate short range pairing correlation as well as direct nucleon-nucleon collisions. A time evolution of the nuclear breakup from a correlated system leading to the emission of two particles to the continuum is performed. We show that initial correlations have strong influence on relative angles between particles emitted in coincidence. The present qualitative study indicates that nuclear breakup might be a tool to infer the residual interaction between nucleons in the nuclear medium.

Assie, Marlene [Institut de Physique Nucleaire, Universite Paris-Sud-11-CNRS/IN2P3, 91406 Orsay (France); GANIL, Boulevard Henri Becquerel, BP 55027, 14076 Caen Cedex 5 (France); Lacroix, Denis [GANIL, Boulevard Henri Becquerel, BP 55027, 14076 Caen Cedex 5 (France)

2009-05-22

63

Theory of Bose–Einstein condensation mechanism for deuteron-induced nuclear reactions in micro\\/nano-scale metal grains and particles  

Microsoft Academic Search

Recently, there have been many reports of experimental results which indicate occurrences of anomalous deuteron-induced nuclear\\u000a reactions in metals at low energies. A consistent conventional theoretical description is presented for anomalous low-energy\\u000a deuteron-induced nuclear reactions in metal. The theory is based on the Bose–Einstein condensate (BEC) state occupied by deuterons\\u000a trapped in a micro\\/nano-scale metal grain or particle. The theory

Yeong E. Kim

2009-01-01

64

Ab initio many-body calculations of deuteron-He4 scattering and Li6 states  

NASA Astrophysics Data System (ADS)

We extend the ab initio no-core shell model/resonating-group method (NCSM/RGM) to projectile-target binary-cluster states where the projectile is a deuteron. We discuss the formalism in detail and give algebraic expressions for the integration kernels. Using a soft similarity-renormalization-group evolved chiral nucleon-nucleon potential, we calculate deuteron-He4 scattering and investigate Li6 bound and unbound states. Virtual three-body breakup effects are obtained in an approximated way by including excited pseudostates of the deuteron in the calculation. We compare our results to experiment and to a standard NCSM calculation for Li6.

Navrátil, Petr; Quaglioni, Sofia

2011-04-01

65

Deuteron electric polarizability  

NASA Astrophysics Data System (ADS)

The deuteron electric polarizability is calculated and the various contributions are analyzed theoretically. Upper limits are constructed from zero-range approximations. These analytic approximations explicate the smallness of the deviation of the exact numerical results from the zero-range approximation using no odd-parity forces and no deuteron D state. [NUCLEAR STRUCTURE Electric polarizability.

Friar, J. L.; Fallieros, S.

1984-01-01

66

Effect of the phase space factor in the breakup of composite particles  

NASA Astrophysics Data System (ADS)

The need to include the phase space factor in the analysis of ? breakup spectra according to Fermi's Golden Rule is indicated. The importance of the number of particles present in the final state is exemplified by a model calculation for proton, deuteron, and triton spectra produced by the breakup of 160 MeV alphas on zirconium. NUCLEAR REACTIONS phase space factor, model alpha breakup spectra for Zr(?,xp), Zr(?,xd), and Zr(?,xt) reactions at E?=160 MeV.

Pai?, G.; Antolkovi?, B.

1981-04-01

67

6Li breakup from 208Pb target at Coulomb barrier energies: doorway to reaction mechanism induced by loosely bound\\/halo nuclei  

Microsoft Academic Search

The breakup cross section of the system 6Li + 208Pb has been measured at four beam energies close to the Coulomb barrier and the excitation energy distributions of the alpha + d\\/6Li* system have been deduced. Comparison of the experimental data with two different theoretical approaches strongly supports the direct breakup process description.

M. Mazzocco; P. Scopel; C. Signorini; L. Fortunato; F. Soramel; I. J. Thompson; A. Vitturi; M. Barbui; A. Brondi; M. Cinausero; D. Fabris; E. Fioretto; G. La Rana; M. Lunardon; R. Moro; A. Ordine; G. F. Prete; V. Rizzi; L. Stroe; M. Trotta; E. Vardaci; G. Viesti

2004-01-01

68

Theory and suppression of multibunch beam breakup in linear colliders  

SciTech Connect

The authors recently developed an analytic theory of cumulative multibunch beam breakup that includes a linear variation of transverse focusing across the bunch train. The focusing variation saturates the exponential growth of the beam breakup and establishes an algebraic decay of the transverse bunch displacement versus bunch number. In this paper they illustrate how the focusing variation works to suppress multibunch beam breakup, as well as how the mechanism scales with accelerator and beam parameters.

Courtlandt L. Bohn and King-Yuen Ng

2000-08-08

69

Peripherality of breakup reactions  

SciTech Connect

The sensitivity of elastic breakup to the interior of the projectile wave function is analyzed. Breakup calculations of loosely bound nuclei ({sup 8}B and {sup 11}Be) are performed with two different descriptions of the projectile. The descriptions differ strongly in the interior of the wave function, but exhibit identical asymptotic properties, namely the same asymptotic normalisation coefficient, and phase shifts. Breakup calculations are performed at intermediate energies (40-70 MeV/nucleon) on lead and carbon targets as well as at low energy (26 MeV) on a nickel target. No dependence on the projectile description is observed. This result confirms that breakup reactions are peripheral in the sense that they probe only the external part of the wave function. These measurements are thus not directly sensitive to the total normalization of the wave function, i.e., spectroscopic factor.

Capel, P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T2A3 (Canada); Nunes, F. M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

2007-05-15

70

Visualization of polymer blending and drop breakup  

NASA Astrophysics Data System (ADS)

Polymer blends are attractive because they provide improved performance and enhanced properties over homopolymers. The final blend properties depend on morphology, and the morphology, in turn, is controlled by the blending process. Therefore, it is vital to understand how one polymer drop incorporates into a second kind of polymer and how the final particle distribution is obtained. Accordingly, this thesis focuses on visualization of one polymer drop melting, deforming and breaking up inside another polymer melt under shear flow. Two kinds of visualization geometries were used: parallel plate and Couette. It was found that drop breakup in polymer systems can occur at all viscosity ratios even when the viscosity ratio is greater than 3.5. This has been proven to be impossible for Newtonian systems in simple shear flows. At least four kinds of distinct drop breakup mechanisms were observed in uncompatibilized polymer systems subject to simple shear: "erosion", "parallel breakup", "vorticity alignment and breakup" and "tip streaming". The first three mechanisms are unique to viscoelastic systems. In Newtonian systems, drop breakup can be well described with Capillary number and viscosity ratio. For polymer systems, besides interfacial tension, viscosity ratio and shear rate, there are other important governing factors, such as shear history, normal stresses and relaxation time. The stress ratio and the drop Deborah number are two important dimensionless parameters that were used to describe drop breakup in polymer systems. In compatibilized systems, the copolymer may promote drop breakup if the copolymer is saturated and distributes homogeneously across the interface; conversely, it may stabilize the drop if there is a concentration gradient and insufficient coverage at the interface in which case a tiny tip develops. Fast in-situ reaction assists drop breakup by stretching the drop into a thin sheet, whereas slow reaction delays drop breakup since newly formed copolymer product accumulates at the drop tips. Finally, this thesis shows that deformation, melting and mixing mechanisms affect the morphology of compatibilized polymers blends. By controlling melting and mixing sequences, it is possible to control the final mean particle size and particle size distribution and thereby influence final properties.

Lin, Bin

71

Ab initio many-body calculations of deuteron-{sup 4}He scattering and {sup 6}Li states  

SciTech Connect

We extend the ab initio no-core shell model/resonating-group method (NCSM/RGM) to projectile-target binary-cluster states where the projectile is a deuteron. We discuss the formalism in detail and give algebraic expressions for the integration kernels. Using a soft similarity-renormalization-group evolved chiral nucleon-nucleon potential, we calculate deuteron-{sup 4}He scattering and investigate {sup 6}Li bound and unbound states. Virtual three-body breakup effects are obtained in an approximated way by including excited pseudostates of the deuteron in the calculation. We compare our results to experiment and to a standard NCSM calculation for {sup 6}Li.

Navratil, Petr [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Lawrence Livermore National Laboratory, P.O. Box 808, L-414, Livermore, California 94551 (United States); Quaglioni, Sofia [Lawrence Livermore National Laboratory, P.O. Box 808, L-414, Livermore, California 94551 (United States)

2011-04-15

72

Secondary breakup of coal water slurry drops  

Microsoft Academic Search

To investigate secondary atomization of coal water slurry (CWS), deformation and breakup of eight kinds of CWS drops are presented using high speed digital camera. Based on morphology, deformation and breakup regimes of CWS drops can be termed some different modes: deformation, multimode breakup (including two sub-modes: hole breakup and tensile breakup), and shear breakup. Correlations on the ranges of

Hui Zhao; Hai-Feng Liu; Jian-Liang Xu; Wei-Feng Li

2011-01-01

73

Compact LINAC for deuterons  

SciTech Connect

We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

Kurennoy, S S [Los Alamos National Laboratory; O' Hara, J F [Los Alamos National Laboratory; Rybarcyk, L J [Los Alamos National Laboratory

2008-01-01

74

Configuration-space Faddeev calculation for proton-deuteron observables at energy E{sub lab} = 3 MeV  

SciTech Connect

A new computational method for solving the nucleon-deuteron breakup scattering problem has been applied to study the elastic neutron- and proton-deuteron scattering on the basis of the configuration-space Faddeev-Noyes-Noble-Merkuriev equations. This method is based on the spline-decomposition in the angular variable and on a generalization of the Numerov method for the hyperradius. The Merkuriev-Gignoux-Laverne approach has been generalized for arbitrary nucleon-nucleon potentials and with an arbitrary number of partial waves taken into account. The nucleon-deuteron observables at the incident nucleon energy 3 MeV have been calculated using the charge-independent AV14 nucleon-nucleon potential including the Coulomb force for the proton-deuteron scattering. Results have been compared with those of other authors and with experimental proton-deuteron scattering data.

Suslov, V. M.; Filikhin, I.; Vlahovic, B.; Slaus, I. [Department of Physics, North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707,USA (United States); Braun, M. A. [Department of Physics, North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707,USA (United States); Department of High Energy Physics and Elementary Particles,Saint-Petersburg State University, 198504, Petrodvorets, St. Petersburg (Russian Federation)

2011-10-24

75

Excitation of the ?(1232) isobar in deuteron charge exchange on hydrogen at 1.6, 1.8, and 2.3 GeV  

NASA Astrophysics Data System (ADS)

The charge-exchange break-up of polarised deuterons d?p?{n, where the final { diproton system has a very low excitation energy and hence is mainly in the S01 state, is a powerful tool to probe the spin-flip terms in the proton-neutron charge-exchange scattering. Recent measurements with the ANKE spectrometer at the COSY storage ring at 1.6, 1.8, and 2.27 GeV have extended these studies into the pion-production regime in order to investigate the mechanism for the excitation of the ?(1232) isobar in the d?p?{X reaction. Values of the differential cross section and two deuteron tensor analysing powers, A and A, have been extracted as functions of the momentum transfer to the diproton or the invariant mass MX of the unobserved system X. The unpolarised cross section in the high MX region is well described in a model that includes only direct excitation of the ? isobar through undistorted one pion exchange. However, the cross section is grossly underestimated for low MX, even when ? excitation in the projectile deuteron is included in the calculation. Furthermore, direct ? production through one pion exchange only reproduces the angular dependence of the difference between the two tensor analysing powers.

Mchedlishvili, D.; Barsov, S.; Carbonell, J.; Chiladze, D.; Dymov, S.; Dzyuba, A.; Engels, R.; Gebel, R.; Glagolev, V.; Grigoryev, K.; Goslawski, P.; Hartmann, M.; Imambekov, O.; Kacharava, A.; Kamerdzhiev, V.; Keshelashvili, I.; Khoukaz, A.; Komarov, V.; Kulessa, P.; Kulikov, A.; Lehrach, A.; Lomidze, N.; Lorentz, B.; Macharashvili, G.; Maier, R.; Merzliakov, S.; Mielke, M.; Mikirtychyants, M.; Mikirtychyants, S.; Nioradze, M.; Ohm, H.; Papenbrock, M.; Prasuhn, D.; Rathmann, F.; Serdyuk, V.; Seyfarth, H.; Stein, H. J.; Steffens, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Trusov, S.; Uzikov, Yu.; Valdau, Yu.; Wilkin, C.

2013-10-01

76

Coulomb breakup problem.  

PubMed

We formulate scattering theory in the framework of a surface-integral approach utilizing analytically known asymptotic forms of the three-body wave functions. This formulation is valid for both short-range and Coulombic potentials. The post and prior forms of the breakup amplitude are derived without any reference to renormalization procedures. PMID:19113531

Kadyrov, A S; Bray, I; Mukhamedzhanov, A M; Stelbovics, A T

2008-12-05

77

On the breakup and coalescence of continents  

Microsoft Academic Search

Reconstructions of the past positions of the continents indicate that at least twice a supercontinent has formed and subsequently split and dispersed as smaller continents. This has led to speculation about the existence of a periodic cycle of supercontinent coalescence and breakup, for which various mechanisms involving mantle dynamics have been proposed. In this paper we investigate the plate-tectonic system

Christopher C. Duncan; Donald L. Turcotte

1994-01-01

78

Inclusive Proton Energy Spectra of the Deuteron Induced Reaction  

NASA Astrophysics Data System (ADS)

The continuum-discritized coupled channel method and the glauber model are applied for the description of deuteron elastic breakup and the stripping processes, respectively. Combined with the conventional two-component exciton model for pre-equilibrium processes and the Hauser-Feshbach theory for compound process, an approach based on models is proposed to analyze the inclusive proton energy spectra of a deuteron-induced reaction. The contributions from each process to the energy spectra of the 58Ni(d,xp) reaction are quantitatively given. The results show that this approach is able to reasonably reproduce the experimental data of the double differential cross sections, energy spectra and cross sections, although further improvements are needed.

Wang, Jia; Ye, Tao; Sun, Wei-Li; Yukinobu, Watanabe; Kazuyuki, Ogata

2011-11-01

79

Large Q{sup 2} electrodisintegration of the deuteron in the virtual nucleon approximation  

SciTech Connect

The two-body breakup of the deuteron is studied at high-Q{sup 2} kinematics, with the main motivation to probe the deuteron at small internucleon distances. Such studies are associated with the probing of the high-momentum component of the deuteron wave function. For this, two main theoretical issues have been addressed: electromagnetic interaction of the virtual photon with the bound nucleon and the strong interaction of produced baryons in the final state of the breakup reaction. Within virtual nucleon approximation we developed a new prescription to account for the bound nucleon effects in electromagnetic interaction. The final-state interaction at high-Q{sup 2} kinematics is calculated within the generalized eikonal approximation (GEA). We studied the uncertainties involved in the calculation and performed comparisons with the first experimental data on deuteron electrodisintegration at large Q{sup 2}. We demonstrate that the experimental data confirm the GEA's early prediction that the rescattering is maximal at approx70 deg. of recoil nucleon production relative to the momentum of the virtual photon. Comparisons also show that the forward recoil nucleon angles are best suited for studies of the electromagnetic interaction of bound nucleons and the high-momentum structure of the deuteron. Backward recoil angle kinematics show sizable effects owing to the DELTA-isobar contribution. The latter indicates the importance of further development of the GEA to account for the inelastic transitions in the intermediate state of the electrodisintegration reactions.

Sargsian, Misak M. [Florida International University, Miami, Florida 33199 (United States)

2010-07-15

80

Electric polarizability of the deuteron  

NASA Astrophysics Data System (ADS)

An experimental value of the electric polarizability of the deuteron is extracted from deuteron photoabsoption data, a dispersion relation, and the low-energy theorem for Compton scattering. The experimental number requires the calculation of several small corrections, which are primarily magnetic in origin. Our value is somewhat smaller than, but consistent with, a recently reported experimental determination. NUCLEAR STRUCTURE Deuteron; electric polarizability; photodisintegration; sum rules.

Friar, J. L.; Fallieros, S.; Tomusiak, E. L.; Skopik, D.; Fuller, E. G.

1983-03-01

81

Study of three-nucleon force effects in p ? + d break-up with BINA  

Microsoft Academic Search

Extensive studies of three-nucleon force (3NF) effects in elastic proton-deuteron scattering have been performed at KVI and elsewhere in the past. In the present work, we explored 3NF effects in the break-up scattering process by performing high precision measurement of vector analyzing powers and differential cross sections using a 190 MeV polarized-proton beam on a liquid deuterium target. The experiment

H. Mardanpour; H. R. Amir-Ahmadi; R. Benard; A. Biegun; M. Eslami-Kalantari; N. Kalantar-Nayestanaki; M. Kis; A. Kozela; H. Kuboki; Y. Maeda; M. Mahjour-Shafiei; J. G. Messchendorp; K. Miki; S. Noji; A. Ramazani; H. Sakai; M. Sasano; K. Sekiguchi; E. Stephan; R. Sworst; Y. Takahashi; K. Yako

2007-01-01

82

Investigation of the mechanism of inelastic deuteron scattering on {sup 12}C at E{sub d} = 15.3 MeV by the method of d{gamma} angular correlations  

SciTech Connect

The results are presented that were obtained by measuring the differential cross sections for the reaction {sup 12}C(d,d) {sup 12}C occurring at E{sub d} = 15.3 MeV and leading to the production of a {sup 12}C nucleus in the ground and the first excited state. The energy dependences of the differential reaction cross sections were measured for three angles of deuteron emission in the range of projectile-deuteron energies E{sub d} between 12 and 15.3 MeV. The double-differential cross sections for the reaction in question were measured for the 2{sup +} state of the {sup 12}C nucleus at 4.44 MeV, and the angular dependences of the even spin-tensor components of the density matrix were determined, along with the angular dependences of the populations of magnetic sublevels and the components of the tensors of multipole-moment orientation. These experimental results are compared with their theoretical counterparts obtained under the assumption of various reaction mechanisms, including collective interaction, heavy-particle stripping, a two-step mechanism that takes into account the delay in the interaction, and the mechanism of compound-nucleus formation.

Galanina, L. I.; Zelenskaya, N. S.; Lebedev, V. M.; Orlova, N. V.; Serikov, O. I.; Spassky, A. V.; Konyukhova, I. A. [Moscow State University, Institute of Nuclear Physics (Russian Federation)], E-mail: wg2@anna19.sinp.msu.ru

2007-02-15

83

JET BREAK-UP IN ELECTROHYDRODYNAMIC ATOMIZATION IN THE CONE-JET MODE  

Microsoft Academic Search

The jet break-up mechanism has been investigated with a high-resolution camera . A model is presented, which is able to predict the droplet size, the velocity at jet break-u p, and the wavelength at jet break-up. A new theoretical derivation of the droplet size scaling will be given. It was found that the jet break-up mechanism depends on the ratio

R. P. A. Hartman; D. J. Brunner; D. M. A. Camelot; J. C. M. Marijnissen; B. Scarlett

2000-01-01

84

Benchmarking models of breakup reactions  

NASA Astrophysics Data System (ADS)

The continuum discretised couple-channel model (CDCC) and the dynamical eikonal approximation (DEA) are two state-of-the-art models used to study the breakup of halo nuclei. In this work, we compare them for the breakup of 15C on Pb at 68AMeV. Excellent agreement is obtained for both energy and angular distributions. Slight discrepancy is observed in the contributions of some partial waves, which might affect other breakup observables, like momentum distributions. The use of relativistic velocity has little effect on the energy distribution, but affects more significantly the angular distribution.

Capel, P.; Nunes, F. M.

2011-09-01

85

Magmatism and deformation during continental breakup  

NASA Astrophysics Data System (ADS)

The rifting of continents and the transition to seafloor spreading is characterised by extensional faulting and thinning of the lithosphere, and is sometimes accompanied by voluminous intrusive and extrusive magmatism. In order to understand how these processes develop over time to break continents apart, we have traditionally relied on interpreting the geological record at the numerous fully developed, ancient rifted margins around the world. In these settings, however, it is difficult to discriminate between different mechanisms of extension and magmatism because the continent-ocean transition is typically buried beneath thick layers of volcanic and sedimentary rocks, and the tectonic and volcanic activity that characterised breakup has long-since ceased. Ongoing continental breakup in the African and Arabian rift systems offers a unique opportunity to address these problems because it exposes several sectors of tectonically active rift sector development spanning the transition from embryonic continental rifting in the south to incipient seafloor spreading in the north. Here I synthesise exciting, multidisciplinary observational and modelling studies using geophysical, geodetic, petrological and numerical techniques that uniquely constrain the distribution, time-scales, and interactions between extension and magmatism during the progressive breakup of the African Plate. This new research has identified the previously unrecognised role of rapid and episodic dike emplacement in accommodating a large proportion of extension during continental rifting. We are now beginning to realise that changes in the dominant mechanism for strain over time (faulting, stretching and magma intrusion) impact dramatically on magmatism and rift morphology. The challenge now is to take what we're learned from East Africa and apply it to the rifted margins whose geological record documents breakup during entire Wilson Cycles.

Keir, Derek

2013-04-01

86

A new model for elastic deuteron-deuteron scattering  

Microsoft Academic Search

Summary  Straightforward application of the Glauber multiple scattering theory is dramatically challenged by data on elastic detueron-deuteron\\u000a (d-d) scattering. The challenge has been argued to be met by an improved representation of the ground-state wave function\\u000a of the deuteron as an admixture ofS-andD-waves. In the light of the failure of the Glauber and geometrical picture models in general, to explain proton-proton

E. Etim; L. Satta

1989-01-01

87

Secondary breakup of coal water slurry drops  

NASA Astrophysics Data System (ADS)

To investigate secondary atomization of coal water slurry (CWS), deformation and breakup of eight kinds of CWS drops are presented using high speed digital camera. Based on morphology, deformation and breakup regimes of CWS drops can be termed some different modes: deformation, multimode breakup (including two sub-modes: hole breakup and tensile breakup), and shear breakup. Correlations on the ranges of breakup modes are also obtained. The conventional Weber number and Ohnesorge number are found to be insufficient to classify all breakup modes of CWS drops, so two other non-dimensional numbers based on rheology of CWS are suggested to use in the deformation and breakup regime map. Finally, total breakup time is studied and correlated, which increases with Ohnesorge number.

Zhao, Hui; Liu, Hai-Feng; Xu, Jian-Liang; Li, Wei-Feng

2011-11-01

88

Dynamical effects in proton breakup from exotic nuclei  

NASA Astrophysics Data System (ADS)

This contribution discusses dynamical effects in proton breakup from a weakly bound state in an exotic nucleus on a heavy target. The Coulomb interactions between the proton and the core and the proton and the target are treated to all orders, including also the full multipole expansion of the Coulomb potential. The dynamics of proton Coulomb breakup is compared to that of an equivalent neutron of larger binding energy in order to elucidate the differences with the well understood neutron breakup mechanism. A number of experimentally measurable observables such as parallel momentum distributions, proton angular distributions and total breakup cross sections can be calculated. With respect to nuclear breakup it is found that a proton behaves exactly as a neutron of larger binding energy. The extra ``effective energy'' is due to the combined core-target Coulomb barrier. In Coulomb breakup we distinguish the effect of the core-target Coulomb potential (called recoil effect), with respect to which the proton behaves again as a more bound neutron, from the direct proton-target Coulomb potential. The latter gives cross sections about an order of magnitude larger than the recoil term. The two effects give rise to complicated interferences in the parallel momentum distributions. They are instead easily separable in the proton angular distributions which are therefore suggested as a very useful observable for future experimental studies.

Bonaccorso, Angela; Kumar, Ravinder

2012-10-01

89

Dynamical effects in proton breakup from exotic nuclei  

NASA Astrophysics Data System (ADS)

We study dynamical effects in proton breakup from a weakly bound state in an exotic nucleus on a heavy target. The Coulomb interactions between the proton and the core and between the proton and the target are treated to all orders, including also the full multipole expansion of the Coulomb potential. The dynamics of proton nuclear and Coulomb breakup is compared to that of an equivalent neutron of higher binding energy in order to elucidate the differences with the well-understood neutron breakup mechanism. A number of experimentally measurable observables such as parallel momentum distributions, proton angular distributions, and total breakup cross sections are calculated. With respect to nuclear breakup it is found that a proton behaves exactly as a neutron of higher binding energy. The extra “effective energy” is caused by the combined core-target Coulomb barrier. In Coulomb breakup we distinguish the effect of the core-target Coulomb potential (called the recoil effect), with respect to which the proton behaves, again, as a more bound neutron, from the direct proton-target Coulomb potential. The latter gives cross sections about an order of magnitude larger than the recoil term. The two effects give rise to complicated interferences in the parallel momentum distributions. They are instead easily separable in the proton angular distributions, which are therefore suggested as a very useful observable for future experimental studies.

Kumar, Ravinder; Bonaccorso, Angela

2011-07-01

90

Inclusive electrodisintegration of polarised deuterons  

Microsoft Academic Search

The general structure of the asymmetries of longitudinally polarised electron scattering by deuterons with vector and tensor polarisations has been established for the process e-+d to e-+n+p using the structure function formalism and considering the deuteron as an elementary particle with a unit spin and a positive space parity. The analysis has been performed in terms of the one-photon approximation

M. P. Rekalo; G. I. Gakh; A. P. Rekalo

1987-01-01

91

Basis for Breakup States of Three Identical Particles  

NASA Astrophysics Data System (ADS)

A new basis for expanding three-body momentum-space states for three identical particles is studied. The basis states are simultaneously eigenstates of the total angular momentum and the total antisymmetrization operator. The total kinetic energy and two Dalitz-Fabri variables are chosen as the remaining three continuous variables. Zernike polynomials are used as a basis set for a generalized Fourier expansion in the Dalitz-Fabri variables. Born approximations to the nucleon-deuteron breakup amplitude (zero total orbital angular momentum) are calculated for Malfliet-Tjon I-III potentials and displayed in a Dalitz plot that shows the global structures of the reaction probabilities. Numerical results are presented, which indicate favorable convergence properties of the generalized Fourier expansion. These results suggest that the new basis set may be attractive in more realistic calculations.

Chandler, C.; Gibson, A. G.

92

Dynamics of drop or bubble breakup in a turbulent flow  

Microsoft Academic Search

The deformation of a drop (or bubble) in a turbulent flow combines two complex physical mechanisms: turbulence and interfacial-tension driven flows (1). Our purpose is to determine the minimal description of these two mechanisms required to predict the occurrence of drop breakup. The first major step was achieved by Kolmogorov (2) and Hinze (3) who considered a drop immersed in

Frederic Risso

93

Deuteron and anti-deuteron production in CERN experiment NA44  

SciTech Connect

The abundances of light nuclei probe the later stages of the evolution of a system formed in a relativistic heavy-ion collision. After the system has cooled and expanded, nucleons in close proximity and moving with small relative momenta coalesce to form nuclei. Light nuclei production enables the study of several topics, including the mechanism of composite particle production, freeze-out temperature, size of the interaction region, and entropy of the system. NA44 is the only relativistic heavy-ion experiment to have both deuteron and anti-deuteron results in both pA and AA collisions and the first CERN experiment to study the physics topics addressed by d and {bar d} production.

Simon-Gillo, J.

1995-04-01

94

Polarized deuteron beam at the Dubna synchrophasotron.  

National Technical Information Service (NTIS)

The experimental equipment and setup used to accelerate a polarized deuteron beam at the Dubna synchrophasotron are briefly described. Basic characteristics of the cryogenic source of polarized deuterons POLARIS are presented. The results of measurements ...

V. P. Ershov V. V. Fimushkin G. I. Gai

1990-01-01

95

Phenomenology of the deuteron electromagnetic form factors  

Microsoft Academic Search

:   A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering,\\u000a at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is\\u000a used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer\\u000a range 0-7 fm?1. This procedure

David Abbott; Abdellah Ahmidouch; H. Anklin; J. Arvieux; James P. Ball; Shelton Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; Jim Dunne; Lars Ewell; L. Eyraud; C. Furget; M. Garçcon; Ron Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; A. Honegger; J. Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; Pete Markowitz; Justin McIntyre; David Meekins; F. Merchez; Joseph Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; Liming Qin; Ronald Ransome; J.-S. Réal; Philip Roos; Paul Rutt; Reyad Sawafta; Stepan Stepanyan; Raphael Tieulent; E. Tomasi-Gustafsson; William Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; Claude Williamson; Stephen Wood; Chen Yan; Jianguo Zhao; W. Zhao

2000-01-01

96

Hard breakup of two nucleons from the He3 nucleus  

NASA Astrophysics Data System (ADS)

We investigate a large angle photodisintegration of two nucleons from the He3 nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, NN hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic He3 wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for NN scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as s-11. Second, the s11 weighted cross section will have the shape of energy dependence similar to that of s10 weighted NN elastic scattering cross section. Also one predicts an enhancement of the pp breakup relative to the pn breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn breakup cross sections. This is due to the fact that the same-helicity pp-component is strongly suppressed in the ground state wave function of He3. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer NN breakup reactions for circularly polarized photons. For the pp breakup this asymmetry is predicted to be zero while for the pn it is close to (2)/(3).

Sargsian, Misak M.; Granados, Carlos

2009-07-01

97

Drop breakup and deformation in sudden onset strong flows  

NASA Astrophysics Data System (ADS)

This work characterizes the deformation and breakup of a single drop subjected to a sudden onset shear flow. The drop is immersed in a second fluid (the matrix) with which it is immiscible. A cylindrical couette device is used to create a flow field which, in the absence of the drop, would constitute a close approximation of simple shear flow. The magnitude of the imposed shear rate was greater than that which would be necessary to just break the drop. The experiments conducted were limited to matrix fluid viscosities above 7Pa? s and shear rates below 15/s, ensuring that the flows considered were inertialess. The matrix fluid was a corn syrup solution. The drop fluids were polybutadiene, paraffin oil and silicone oil, leading to a range of interfacial tensions. At the shear rates used in these experiments the fluids used Newtonian. Viscosity ratios (drop/matrix) ranging from 0.01 to 1 were considered. Two breakup mechanisms were observed to contribute to the dispersion of the original drop. In all cases elongative end pinching, defined by this study, caused the ends of a stretching drop to break off and form daughter drops. Breakup due to elongative end pinching was always the first breakup observed. The daughter drops formed by elongative end pinching were always the largest daughter drops formed. In cases when the experimental conditions were sufficiently stronger than the critical conditions (needed to just barely break up the drop), a second type of breakup, capillary wave breakup, was also observed. Measurement of the characteristic time scales and length scales were made of each type of breakup. The lengths (a) were found to scale as capillary numbers: Ca=a mg/s. The times (t) were found to scale as strains: s=t g. A qualitative explanation for the capillary number scaling is presented and quantitatively compared to predictions based on small deformation analysis. Additionally the daughter drop size distributions resulting from drop breakup is characterized. These distributions are shown to be dependent on the relative dominance of the two breakup mechanisms observed.

Marks, Charles Raphael

98

Phenomenology of the deuteron electromagnetic form factors  

SciTech Connect

A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.

David Abbott; Abdellah Ahmidouch; H. Anklin; J. Arvieux; James P. Ball; Shelton Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; Jim Dunne; Lars Ewell; L. Eyraud; C. Furget; Michel Garcon; Ron Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; A. Honegger; J. Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; Pete Markowitz; Justin McIntyre; David Meekins; F. Merchez; Joseph Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; Liming Qin; Ronald Ransome; J.-S. R'eal; Philip Roos; Paul Rutt; Reyad Sawafta; Stepan Stepanyan; Raphael Tieulent; E. Tomasi-Gustafsson; William Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; Claude Williamson; Stephen Wood; Chen Yan; Jianguo Zhao; W. Zhao

2000-04-01

99

Phenomenology of the deuteron electromagnetic form factors  

SciTech Connect

A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.

David Abbott; Abdellah Ahmidouch; H. Anklin; J. Arvieux; James P. Ball; Shelton Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; Jim Dunne; Lars Ewell; L. Eyraud; C. Furget; Michel Garcon; Ron Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; A. Honegger; J. Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; Pete Markowitz; Justin McIntyre; David Meekins; F. Merchez; Joseph Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; Liming Qin; Ronald Ransome; J.-S. R'eal; Philip Roos; Paul Rutt; Reyad Sawafta; Stepan Stepanyan; Raphael Tieulent; E. Tomasi-Gustafsson; William Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; Claude Williamson; Stephen Wood; Chen Yan; Jianguo Zhao; W. Zhao

2000-02-25

100

Review of semi-classical calculations for breakup  

SciTech Connect

In semi-classical approximations, the relative motion between target and projectile is represented by a classical trajectory but the projectile internal motion is treated quantum mechanically. A time-dependent Schroedinger equation describes the breakup of exotic nuclei induced by the Coulomb and nuclear forces. Different accurate techniques of resolution of this time-dependent equation are reviewed for one space dimension. The respective merits of their extensions to three dimensions are compared. Applications to the breakup of the 11Be, 15C, and 19C halo nuclei are presented and discussed. The first-order perturbation theory is compared with the time-dependent method and its relevance for the Coulomb breakup determination of the astrophysical S factor is analyzed.

Baye, Daniel [Physique Quantique, C.P. 165/82, Universite Libre de Bruxelles, B 1050 Brussels (Belgium); Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles, B 1050 Brussels (Belgium)

2005-10-14

101

Breakup of drops and bubbles translating through cylindrical capillaries  

NASA Astrophysics Data System (ADS)

We examine the shape deformation and breakup of air bubbles and viscous drops moving through vertical cylindrical capillaries under the action of pressure and/or buoyancy forces. Experimental observations of fluid particle shape are reported over a wide range of particle sizes and capillary numbers in a variety of two-phase systems. Four different modes of breakup are identified, and the critical conditions for the onset of various modes are examined. It is found that buoyancy forces can have a stabilizing effect on the breakup mechanism observed by Olbricht and Kung [Phys. Fluids 4, 134, (1992)] for low viscosity-ratio drops, wherein a growing indentation at the trailing end of the drop develops into a penetrating jet of outer phase fluid.

Borhan, A.; Pallinti, J.

1999-10-01

102

Surfactant Effects in Jet Breakup  

NASA Astrophysics Data System (ADS)

Surfactants are used in applications ranging from crop spraying to ink jet printing to control jet breakup. Nonlinear dynamics and breakup of a jet of a Newtonian fluid whose surface is covered with an insoluble surfactant are studied by a temporal analysis. An initially quiescent jet is subjected to axially periodic shape and/or surfactant concentration perturbations. The subsequent dynamics are followed numerically until pinch-off by both a 3-d axisymmetric (2-d) and a 1-d slender-jet algorithm. Results computed with the 2-d algorithm are verified against predictions from linear theory for short times and those from scaling analyses close to pinch-off. Breakup times and ratios of volumes of primary to satellite drops are reported over a wide range of Reynolds numbers, amplitudes and wavelengths of perturbations, and surface Peclet numbers. Conditions are identified where the 1-d algorithm can be used with confidence. Furthermore, it is demonstrated that jet breakup can be significantly delayed or enhanced by judicious use of simultaneous shape and surfactant perturbations.

McGough, Patrick; Basaran, Osman

2004-11-01

103

Polarization of the neutron induced by hadronic weak interactions in the photodisintegration of the deuteron  

NASA Astrophysics Data System (ADS)

New polarization observables with which we can study the two-nucleon weak interactions at low energies are considered. In the breakup of the deuteron by photons, polarization of outgoing neutrons can depend on the parity-violating component of two-nucleon interactions. We express the parity-violating polarization in general forms, and perform numerical calculations with a pionless effective field theory. The theory has three unknown parity-violating low energy constants, and new polarization observables are expressed in linear combinations of them. We discuss how the unknown constants may be determined and their implication to the understanding of the hadronic weak interactions.

Shin, J. W.; Hyun, C. H.; Ando, S.-I.; Hong, S. W.

2013-09-01

104

6Li direct breakup lifetimes  

NASA Astrophysics Data System (ADS)

?-d coincidence data are studied for the 6Li + 59Co reaction at E=29.6 MeV. A kinematic analysis is used to identify which process, leading to the same final state, has the major contribution for selected angular regions. The contributions of the 6Li sequential and direct breakup to the incomplete fusion/transfer process is discussed by considering the corresponding lifetimes obtained by using a semiclassical approach.

Souza, F. A.; Carlin, N.; Beck, C.; Keeley, N.; Diaz-Torres, A.; Liguori Neto, R.; Siqueira-Mello, C.; de Moura, M. M.; Munhoz, M. G.; Oliveira, R. A. N.; Del Santo, M. G.; Suaide, A. A. P.; Szanto, E. M.; Szanto de Toledo, A.

2010-03-01

105

Spin structure of the deuteron  

NASA Astrophysics Data System (ADS)

Double spin asymmetries for the proton and the deuteron have been measured in the EG1b experiment using the CLAS detector at Jefferson Lab. Longitudinally polarized electrons at energies 1.6, 2.5, 4.2 and 5.7 GeV were scattered from longitudinally polarized NH3 and ND3 targets. The double spin asymmetry A|| for the proton and the deuteron has been extracted from these data as a function of W and Q 2 with unprecedented precision. The virtual photon asymmetry A1 and the spin structure function g 1 can be calculated from these measurements by using parametrization to the world data for the virtual photon asymmetry A 2 and the unpolarized structure functions F1 and R. The large kinematic coverage of the experiment (0.05 GeV2 < Q2 < 5.0 GeV2 and 1.08 GeV < W < 3.0 GeV) helps us to better understand the spin structure of the nucleon, especially in the transition region between hadronic and quark-gluon degrees of freedom. The results on A1, g1 and the first moment G11 , as well as the higher moments G31 and G51 , using the entire data set for the deuteron, are presented in this thesis. The moments are compared to theoretical and phenomenological calculations. In addition, parameterizations of the world data on the asymmetries and the spin structure functions are studied to create and refine the models on these quantities that can be used in various applications. Finally, the neutron asymmetries are extracted from the combined proton and deuteron data and the preliminary results are demonstrated.

Guler, Nevzat

106

Exclusive Scattering from Unpolarized and Polarized Deuteron  

SciTech Connect

We present results for exclusive electron scattering from polarized and unpolarized deuteron. We employ the Gross equation to describe the deuteron ground state, and we use the SAID parametrization of the full NN scattering amplitude to describe the final state interactions (FSIs). %We include both on-shell and positive-energy off-shell contributions %in our FSI calculation. We discuss properties of various asymmetries accessible with a polarized deuteron target and/or a polarized beam.

Sabine Jeschonnek, Jay Van Orden

2011-03-01

107

Design of Breakup Ice Control Structures  

Microsoft Academic Search

ABSTRACT The primary purpose of a breakup ice control structure (ICS) is to retain a breakup ice run upstream of a traditional ice jam problem area and thereby miti- gate ice-jam flooding. By controlling ice-jam location, breakup ICSs also can prevent ice-related scour associated with dam removals or contaminated sedi- ment remediation projects. This report briefly describes basic ICS types,

Andrew M. Tuthill; James H. Lever

108

Isomer ratio measurements as a probe of the dynamics of breakup and incomplete fusion  

SciTech Connect

The incomplete fusion mechanism following breakup of {sup 6,7}Li and {sup 9}Be projectiles incident on targets of {sup 209}Bi and {sup 208}Pb is investigated through isomer ratio measurements for the {sup 212}At and {sup 211}Po products. The phenomenological analysis presented in this paper indicates that incomplete fusion brings relatively more angular momentum into the system than equivalent reactions with a direct beam of the fused fragment. This is attributed to the trajectories of breakup fragments. Calculations with a 3D classical trajectory model support this. Isomer ratio measurements for incomplete fusion reactions can provide a test of new theoretical models of breakup and fusion.

Gasques, L. R.; Dasgupta, M.; Hinde, D. J.; Peatey, T.; Diaz-Torres, A.; Newton, J. O. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2006-12-15

109

Electrohydrodynamic (EHD) stimulation of jet breakup  

NASA Astrophysics Data System (ADS)

Electrohydrodynamic (EHD) excitation of liquid jets offers an alternative to piezoelectric excitation without the complex frequency response caused by piezoelectric and mechanical resonances. In an EHD exciter, an electrode near the nozzle applies an alternating Coulomb force to the jet surface, generating a disturbance which grows until a drop breaks off downstream. This interaction is modelled quite well by a linear, long wave model of the jet together with a cylindrical electric field. The breakup length, measured on a 33 micrometer jet, agrees quite well with that predicted by the theory, and increases with the square of the applied voltage, as expected. In addition, the frequency response is very smooth, with pronounced nulls occurring only at frequencies related to the time which the jet spends inside the exciter.

Crowley, J. M.

1982-03-01

110

Beam breakup in a microtron  

SciTech Connect

In a microtron, the path length change from pass to pass is a fixed multiple of the RF wavelength, and the accelerating system can be reasonably well approximated as a single cavity. Under such circumstances it is possible to derive an analytical formula for the multipass beam breakup threshold current. The threshold current determined by numerical simulations agrees very well with the formula for a machine with a small number of passes. The analytic formula can serve as a useful guide in examining optics designs to improve the BBU threshold.

Yung, B.C.; Merminga, L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

1997-06-01

111

Development of Methods for Calculation of Deuteron-Lithium and Neutron-Lithium Cross Sections for Energies up to 50 MeV  

SciTech Connect

For the generation of evaluated nuclear data sets required for the International Fusion Materials Irradiation Facility project, the basic features of the deuteron-lithium and neutron-lithium nuclear interactions are examined. Factors complicating the evaluation of deuteron-lithium reaction characteristics and weak points of previous calculations and evaluations are discussed. A new method to obtain double differential cross sections of particles emitted in d+Li reactions is described. The method is based on the diffraction approach, a modified intranuclear cascade model, and the usual evaluation techniques. The cross sections predicted by this method are in good agreement with existing experimental data for deuteron interactions in thick lithium targets. The study of neutron-lithium interactions is performed on the basis of different approaches: coupled channels, diffraction scattering, and direct breakup models.

Konobeyev, A.Yu. [Obninsk Institute of Nuclear Power Engineering (Russian Federation); Korovin, Yu.A. [Obninsk Institute of Nuclear Power Engineering (Russian Federation); Pereslavtsev, P.E. [Obninsk Institute of Nuclear Power Engineering (Russian Federation); Fischer, Ulrich [Forschungszentrum Karlsruhe (Germany); Moellendorff, Ulrich von [Forschungszentrum Karlsruhe (Germany)

2001-09-15

112

High Energy Break-Up of Few-Nucleon Systems  

NASA Astrophysics Data System (ADS)

We discus recent developments in theory of high energy two-body break-up reactions of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon by the outgoing two nucleons. Within HRM we discuss hard break-up reactions involving 2D and 3He targets. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Sargsian, Misak

2008-03-01

113

Effect of drop breakup on fuel sprays  

SciTech Connect

Recently developed computer models are being applied to calculate complex interactions between sprays and gas motions. The three-dimensional KIVA code was modified to address drop breakup and was used to study fuel sprays. The results show that drop breakup influences spray penetration, vaporization and mixing in high pressure sprays. The spray drop size is the outcome of a competition between drop breakup and drop coalescence phenomena, and the atomization details at the injector are lost during these size rearrangements. Drop breakup dominates in hollow-cone sprays because coalescence is minimized by the expanding spray geometry. The results imply that it may be possible to use a simple injector and still control spray drop size and vaporization if the flow details are modified so as to enhance drop breakup and coalescence.

Reitz, R.D.; Diwaker, R.

1986-01-01

114

Pickup coupling effects in deuteron scattering: The case of d+Ca40  

NASA Astrophysics Data System (ADS)

The dynamic polarization potential (DPP) contribution to the effective deuteron-nucleus interaction is evaluated by means of coupled reaction channel (CRC) calculations followed by S-matrix-to-potential inversion. The full coupled channel S matrix Sl'lJ is inverted using the iterative-perturbative algorithm to yield a potential that includes a complex TR tensor term as well as central and spin-orbit components. The differences between the various components of the inverted potential and the corresponding terms in the bare potential of the CRC calculation constitute a local equivalent representation of the complete DPP that is generated by the reaction channel coupling. The magnitude of the DPP, the real part in particular, is much less than that found in earlier calculations in which the nonorthogonality terms were omitted. The characteristic features of the tensor part of the DPP were traced to breakup and reorientation processes in the entrance deuteron channel that had been included with the pickup. The contribution of stripping to the deuteron-nucleus interaction is also discussed.

Keeley, N.; Mackintosh, R. S.

2008-05-01

115

Pickup coupling effects in deuteron scattering: The case of d+{sup 40}Ca  

SciTech Connect

The dynamic polarization potential (DPP) contribution to the effective deuteron-nucleus interaction is evaluated by means of coupled reaction channel (CRC) calculations followed by S-matrix-to-potential inversion. The full coupled channel S matrix S{sub l{sup '}}{sub l}{sup J} is inverted using the iterative-perturbative algorithm to yield a potential that includes a complex T{sub R} tensor term as well as central and spin-orbit components. The differences between the various components of the inverted potential and the corresponding terms in the bare potential of the CRC calculation constitute a local equivalent representation of the complete DPP that is generated by the reaction channel coupling. The magnitude of the DPP, the real part in particular, is much less than that found in earlier calculations in which the nonorthogonality terms were omitted. The characteristic features of the tensor part of the DPP were traced to breakup and reorientation processes in the entrance deuteron channel that had been included with the pickup. The contribution of stripping to the deuteron-nucleus interaction is also discussed.

Keeley, N.; Mackintosh, R. S. [CEA/DSM/IRFU/SPhN Saclay, F-91191 Gif-sur-Yvette Cedex (France); Department of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA (United Kingdom)

2008-05-15

116

The instability growth leading to a liquid sheet breakup  

NASA Astrophysics Data System (ADS)

The instability growth leading to a liquid sheet breakup has been studied with the objective of improving the understanding of the fundamental mechanisms of atomization. A three-dimensional Lagrangian code based on vortex dynamics methods has been implemented to track the air/liquid interfaces treated as inviscid vortex sheets. The results of these numerical simulations indicate a possible explanation for the presence of transverse and longitudinal filaments observed in liquid sheet air-assisted atomization experiments.

Lozano, Antonio; García-Olivares, Antonio; Dopazo, César

1998-09-01

117

Cold Nuclear Matter Effects on J/{psi} Production as Constrained by Deuteron-Gold Measurements at s_NN = 200 GeV  

SciTech Connect

We present a new analysis of J/{psi} production yields in deuteron-gold collisions at {radical}s{sub NN}=200 GeV using data taken from the PHENIX experiment in 2003 and previously published in S. S. Adler et al. The high statistics proton-proton J/psi data taken in 2005 are used to improve the baseline measurement and thus construct updated cold nuclear matter modification factors (R{sub dAu}). A suppression of J/psi in cold nuclear matter is observed as one goes forward in rapidity (in the deuteron-going direction), corresponding to a region more sensitive to initial-state low-x gluons in the gold nucleus. The measured nuclear modification factors are compared to theoretical calculations of nuclear shadowing to which a J/psi (or precursor) breakup cross section is added. Breakup cross sections of {sigma}breakup=2.8{sub -1.4}{sup +1.7} (2.2{sub -1.5}{sup +1.6}) mb are obtained by fitting these calculations to the data using two different models of nuclear shadowing. These breakup cross-section values are consistent within large uncertainties with the 4.2{+-}0.5 mb determined at lower collision energies. Projecting this range of cold nuclear matter effects to copper-copper and gold-gold collisions reveals that the current constraints are not sufficient to firmly quantify the additional hot nuclear matter effect.

Adare, A. [University of Colorado, Boulder; Awes, Terry C [ORNL; Cianciolo, Vince [ORNL; Read Jr, Kenneth F [ORNL; Silvermyr, David O [ORNL; Sorensen, Soren P [University of Tennessee, Knoxville (UTK); Stankus, Paul W [ORNL; Young, Glenn R [ORNL; PHENIX, Collaboration [The

2008-01-01

118

Deuteron-proton breakup reaction at E/sub d/ = 7. 4 MeV  

SciTech Connect

The reaction d+p..-->..p+p+n is investigated at E/sub lab//sup d/ = 7.4 MeV. Calculations of the cross section are compared with recent kinematically complete measurements. The Coulomb potential is taken fully into account in the calculations based on the strong approximation of Moller wave operator approach.

Kroeger, H.; Nachabe, A.M.; Slobodrian, R.J.

1986-04-01

119

Resonant breakup of C19 on a proton target  

NASA Astrophysics Data System (ADS)

The resonant breakup of C19 on a proton target at 70 MeV/nucleon is analyzed using Faddeev-Alt, Grassberger, Sandhas (Faddeev-AGS) and continuum-discretized coupled-channels (CDCC) reaction frameworks, where in both cases a three-body model (18C+n+p) for the reaction is considered. Taking a C18 + p potential from a global nucleon-nucleus parametrization and a L-independent Gaussian proton-neutron potential, both methods provide very similar results for the calculated observables. However, when this simplified proton-neutron potential is replaced by the more realistic CD-Bonn potential, the breakup cross section, calculated with the Faddeev AGS formalism, decreases by almost one order of magnitude, largely underestimating the experimental data. From this calculation, we conclude that, within a core + valence neutron model, the single-particle mechanism gives a negligible contribution to the calculated resonant breakup and therefore core-excitation mechanisms should be taken into account.

Crespo, R.; Rodríguez-Gallardo, M.; Moro, A. M.; Deltuva, A.; Cravo, E.; Fonseca, A. C.

2011-05-01

120

Resonant breakup of {sup 19}C on a proton target  

SciTech Connect

The resonant breakup of {sup 19}C on a proton target at 70 MeV/nucleon is analyzed using Faddeev-Alt, Grassberger, Sandhas (Faddeev-AGS) and continuum-discretized coupled-channels (CDCC) reaction frameworks, where in both cases a three-body model ({sup 18}C+n+p) for the reaction is considered. Taking a {sup 18}C + p potential from a global nucleon-nucleus parametrization and a L-independent Gaussian proton-neutron potential, both methods provide very similar results for the calculated observables. However, when this simplified proton-neutron potential is replaced by the more realistic CD-Bonn potential, the breakup cross section, calculated with the Faddeev AGS formalism, decreases by almost one order of magnitude, largely underestimating the experimental data. From this calculation, we conclude that, within a core + valence neutron model, the single-particle mechanism gives a negligible contribution to the calculated resonant breakup and therefore core-excitation mechanisms should be taken into account.

Crespo, R. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, P-1649-003 Lisboa (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Taguspark, Av. Prof. Cavaco Silva, Taguspark, P-2780-990 Porto Salvo, Oeiras (Portugal); Rodriguez-Gallardo, M. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, P-1649-003 Lisboa (Portugal); Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Moro, A. M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Deltuva, A.; Cravo, E.; Fonseca, A. C. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, P-1649-003 Lisboa (Portugal)

2011-05-15

121

Spin-Flipping Polarized Deuterons At COSY  

NASA Astrophysics Data System (ADS)

We recently stored a 1.85 GeV/c vertically polarized deuteron beam in the COSY Ring in Jülich we then spin-flipped it by ramping a new air-core rf dipole's frequency through an rf-induced spin resonance to manipulate the polarization direction of the deuteron beam. We first experimentally determined the resonance's frequency and set the dipole's rf voltage to its maximum; then we varied its frequency ramp time and frequency range. We used the EDDA detector to measure the vector and tensor polarization asymmetries. We have not yet extracted the deuteron's tensor polarization spin-flip parameters from the measured data, since our short run did not provide adequate tensor analyzing-power data at 1.85 GeV/c. However, with a 100 Hz frequency ramp and our longest ramp time of 400 s, the deuterons' vector polarization spin-flip efficiency was 48+/-1%.

Yonehara, K.; Krisch, A. D.; Morozov, V. S.; Raymond, R. S.; Wong, V. K.; Bechstedt, U.; Gebel, R.; Lehrach, A.; Lorenz, B.; Maier, R.; Prasuhn, D.; Schnase, A.; Stockhorst, H.; Eversheim, D.; Hinterberger, F.; Rohdjess, H.; Ulbrich, K.; Scobel, W.

2004-02-01

122

Nanojets: Electrification, Energetics, Dynamics, Stability and Breakup.  

National Technical Information Service (NTIS)

Simulation methodologies, algorithms, and computer codes allowing molecular dynamics simulations of formation, propagation, and breakup processes of nanojets, generated either through the application of pressure or through the action of an electric field ...

U. Landman

2006-01-01

123

Nuclear and Coulomb breakup of 8 B  

Microsoft Academic Search

One-proton removal reactions of 936 MeV\\/u 8B have been studied with carbon and lead as breakup targets. Using the FRS at GSI, the longitudinal momentum distributions of the 7Be fragments and the one-proton removal cross section of 8B were measured. The relative contributions of the breakup channels leading to 7Be in its ground state and excited state at 429 keV (7Be?) have

D. Cortina-Gil; J. Fernandez-Vazquez; F. Attallah; T. Baumann; J. Benlliure; M. J. G. Borge; L. Chulkov; C. Forssén; L. M. Fraile; H. Geissel; J. Gerl; K. Itahashi; R. Janik; B. Jonson; S. Karlsson; H. Lenske; S. Mandal; K. Markenroth; M. Meister; M. Mocko; G. Münzenberg; T. Ohtsubo; A. Ozawa; Yu. Parfenova; V. Pribora; A. Richter; K. Riisager; R. Schneider; H. Scheit; G. Schrieder; N. Shulgina; H. Simon; B. Sitar; A. Stolz; P. Strmen; K. Sümmerer; I. Szarka; S. Wan; H. Weick; M. V. Zhukov

2003-01-01

124

Bubble Dynamics and Breakup in Straining Flows.  

NASA Astrophysics Data System (ADS)

The dynamics and breakup of a bubble in axisymmetric flow fields has been investigated using numerical and analytical techniques. In particular, the transient bubble deformation, oscillation, and overshoot effects are considered in conjunction with the existence of steady-state solutions. To explore the dynamics of a bubble with a high degree of deformation, a numerical technique suitable for solving axisymmetric, unsteady free boundary problems in fluid mechanics has been developed. The technique is based on a finite-difference solution of the equations of motion on a moving orthogonal curvilinear coordinate system, which is constructed numerically and adjusted to fit the boundary at any time. For example, the steady and unsteady deformations of a bubble in uniaxial and biaxial straining flows are examined for wide ranges of the Reynolds number and the Weber number. As a complementary analytical study to the numerical analysis, the method of domain perturbations is used to investigate the problem of a nearly spherical bubble in an inviscid, axisymmetric straining flow. In order to include the weak viscous effect in the analytical study, a general formula for viscous pressure correction for a spherical bubble in an arbitrary axisymmetric flow has been derived in terms of the vorticity distribution. This formula has also been applied to obtain the drag coefficient C_{D} = 48/R by directly integrating the normal stress over the surface for a spherical bubble in a uniform streaming flow at a high Reynolds number.

Kang, In Seok

125

A literature review of theoretical models for drop and bubble breakup in turbulent dispersions  

Microsoft Academic Search

This paper presents a literature review on mechanisms and models for the breakage of bubbles and drops (fluid particles) in turbulent dispersions. For the mechanisms, four categories are summarized, namely, turbulence fluctuation, viscous shear stress, shearing-off process and interfacial instability. The models for breakup frequency and daughter size distribution available in literature are reviewed thoroughly. The development and limitation of

Yixiang Liao; Dirk Lucas

2009-01-01

126

Relativistically invariant analysis of polarization effects in exclusive deuteron electrodisintegration process  

SciTech Connect

A general formalism for the calculation of the differential cross-section and polarization observables, for the process of deuteron electrodisintegration, is developed in the framework of relativistic impulse approximation. A detailed analysis of the general structure of the differential cross-section and polarization observables for the e {sup -} + d {yields} e {sup -} + n + p reaction is derived, using the formalism of the structure functions. The obtained expressions have a general nature and they hold in the one-photon-exchange mechanism, assuming P-invariance of the hadron electromagnetic interaction. The model of relativistic impulse approximation is introduced and the final state interaction is taken into account by means of the unitarization of the helicity amplitudes. A detailed description of the unitarization procedure is also presented. Using different parametrizations of the deuteron wave functions, the following polarization observables are calculated in the kinematical region of quasi-elastic deuteron electrodisintegration: the asymmetry for the scattering of longitudinally polarized electrons on a polarized deuteron target, the proton and neutron polarizations (for longitudinally polarized electron beam or vector-polarized deuteron target). The sensitivity to the neutron electric form factor is also thoroughly investigated. The predictions of the model are compared with the results of recent polarization measurements and a good agreement with the existing experimental data has been obtained.

Gakh, G.I. [DAPNIA/SPhN, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France); Rekalo, A.P. [DAPNIA/SPhN, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France); Tomasi-Gustafsson, E. [DAPNIA/SPhN, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France)]. E-mail: etomasi@cea.fr

2005-09-01

127

Hard breakup of two nucleons from the {sup 3}He nucleus  

SciTech Connect

We investigate a large angle photodisintegration of two nucleons from the {sup 3}He nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, NN hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic {sup 3}He wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for NN scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as s{sup -11}. Second, the s{sup 11} weighted cross section will have the shape of energy dependence similar to that of s{sup 10} weighted NN elastic scattering cross section. Also one predicts an enhancement of the pp breakup relative to the pn breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn breakup cross sections. This is due to the fact that the same-helicity pp-component is strongly suppressed in the ground state wave function of {sup 3}He. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer NN breakup reactions for circularly polarized photons. For the pp breakup this asymmetry is predicted to be zero while for the pn it is close to (2/3)

Sargsian, Misak M.; Granados, Carlos [Florida International University, Miami, Florida 33199 (United States)

2009-07-15

128

Evaluation of Reentry Breakup and Debris Generation  

NASA Astrophysics Data System (ADS)

Orbital missions launching from Cape Canaveral typically overfly Europe or African before achieving orbital insertion and pose a risk that must be evaluated as part of the overall mission casualty expectation. During the downrange overflight phase, the vehicle is well above the atmosphere and has achieved near orbital velocity, consequently a loss of thrust, loss of control or high altitude breakup will bring either the intact upper stage or smaller secondary debris fragments into the atmosphere and subject them to intense aerodynamic heating. In order to make reasonable risk estimates, it is necessary to first predict the reentry breakup characteristics and the survival of debris fragments. ACTA has developed the Coupled Aeroheating and Thermal Network Solver (CATNS) code to help range safety analysts evaluate reentry breakup and demise.

Nyman, R. L.

2012-01-01

129

Break-up in unsteady separation  

NASA Astrophysics Data System (ADS)

The unsteady break-up of otherwise steady or unsteady separating flows, and unsteady boundary layers in general, is addressed theoretically. The aspects involved are intimately bound up with transition to turbulence in practice. The first aspect is the prediction of the critical position for enhanced instability to occur in separating flow. The second, as a consequence, is the break-up of a separated eddy due to nonlinear unsteady effects, on the small or the large scale. The third aspect is the nonlinear receptivity of attached and separating flows to freestream disturbances. Fourth, and again in consequence, the complete break-up of an unsteady interacting boundary layer is described. Two-versus three-dimensional effects, comparisons with some experimental and computational results, and applications in a number of external and internal flows are also discussed.

Smith, F. T.

130

Prospects for Acceleration of Deuterons and Helions  

SciTech Connect

In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular accelerator, it is the anomalous part of the magnetic moment which is important. If the anomaly is too small, then manipulation becomes difficult as in the case of deuterons--spin rotators and Siberian snakes become ineffective. {sup 3}He nuclei appear to be the easiest choice for a polarized neutron beam. In this paper I discuss the prospects for both helions and deuterons as polarized beams in RHIC or in an electron-ion collider.

MacKay, W. W. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

2008-02-06

131

PROSPECTS FOR ACCELERATION OF DEUTERONS AND HELIONS.  

SciTech Connect

In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular accelerator, it is the anomalous part of the magnetic moment which is important. If the anomaly is too small, then manipulation becomes difficult as in the case of deuterons--spin rotators and Siberian snakes become ineffective. {sup 3}He nuclei appear to be the easiest choice for a polarized neutron beam. In this paper I discuss the prospects for both helions and deuterons as polarized beams in RHIC or in an electron-ion collider.

MACKAY,W.W.

2007-09-10

132

Breakup of microdroplets in asymmetric T junctions  

NASA Astrophysics Data System (ADS)

Symmetric T junctions have been used widely in microfluidics to generate equal-sized microdroplets, which are applicable in drug delivery systems. A newly proposed method for generating unequal-sized microdroplets at a T junction is investigated theoretically and experimentally. Asymmetric T junctions with branches of identical lengths and different cross sections are utilized for this aim. An equation for the critical breakup of droplets at asymmetric T junctions and one for determining the breakup point of droplets are developed. A good agreement was observed between the theories (present and previous) and the experiments.

Samie, Milad; Salari, Alinaghi; Shafii, Mohammad Behshad

2013-05-01

133

Dynamics and Breakup of Viscoelastic Liquids (A Review)  

Microsoft Academic Search

The phenomena of hydrodynamic breakup of liquid jets, drops, films, bridges, and filaments are reviewed for liquids with viscoelastic\\u000a properties. The reasons for breakup are capillary instabilities, collisions with rigid obstacles, and other forms of dynamic\\u000a action. The relationship between the properties of the liquids and the features of the breakup process is discussed.

A. N. Rozhkov

2005-01-01

134

Fluvial thermal erosion during the ice break-up of the Lena river (Siberia)  

NASA Astrophysics Data System (ADS)

The Lena River is one of the largest Arctic rivers; its periglacial environment implies an excessive fluvial regime and a spectacular flood occurring at the end of the winter. From the beginning of November to May, a continuous ice cover can be observed as thick as 2 m on the Lena River in Central Siberia. The break up starts around May 15 at the latitude of Yakutsk, corresponding to a flood wave coming from the South and to an increase of the water stream temperature up to 18°C. In spite of a relatively good understanding of the initial stage of the breakup period of these periglacial rivers [Beltaos and Burrell, 2002; Shen, 2003; Billfalk, 1982], only a few studies report on the role of mechanical and thermal erosion during the breakup Observations and measurements of erosion of the island heads during the first days of the ice breakup were made during breakup periods over a 4-year period (2008-2011). Here, we reassess the efficiency of the fluvial thermal erosion using both high resolution records from field measurements and modeling. We analyze the impact of the breakup on the erosional process on the head of several fluvial islands. Only a few days are enough to produce erosion rate as high as 30 m. The protective effect of the ice cover at the very beginning of the break up has been studied in more detailed during 3 field trips. These values are relatively high but are in good agreement with our modeling.

Costard, F.; Gautier, E.; Fedorov, A.; Konstantinov, P.; Dupeyrat, L.

2012-04-01

135

Phenomenological Lagrangian approach to the electromagnetic deuteron form factors  

SciTech Connect

A phenomenological Lagrangian approach is employed to study the electromagnetic properties of the deuteron. The deuteron is regarded as a weakly bound state of the proton and neutron. We construct a general form for the electromagnetic one- and two-body transition operators formulated in terms of the nucleon fields, which are then used in the calculation of the electromagnetic deuteron form factors. One of the two-body operators is responsible for explaining the quadrupole moment form factor. We show that in our approach the data on the deuteron form factors as well as on the differential cross section of elastic electron-deuteron scattering are well explained.

Dong Yubing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Theoretical Physics Center for Science Facilities (TPCSF), CAS (China); Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E. [Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)

2008-09-15

136

Critical role of pinning defects in scroll-wave breakup in active media  

NASA Astrophysics Data System (ADS)

The breakup of rotating scroll waves in three-dimensional excitable media has been linked to important biological processes. The known mechanisms for this transition almost exclusively involve the dynamics of the scroll filament, i.e., the line connecting the phase singularities. In this paper, we describe a novel defect-induced route to breakup of a scroll wave pinned by an inexcitable obstacle partially extending through the bulk of the medium. The wave is helically wound around the defect inducing sudden changes in velocity components of the wavefront at the obstacle boundary. This results in breakup far from the filament, eventually giving rise to spatiotemporal chaos. Our results suggest a potentially critical role of pinning obstacles in the onset of life-threatening disturbances of cardiac activity.

Sridhar, S.; Ghosh, Antina; Sinha, Sitabhra

2013-09-01

137

Breakup Fusion Theory of Nuclear Reactions  

Microsoft Academic Search

Continuum spectra of particles emitted in incomplete fusion reactions are one of the major interests in current nuclear reaction studies. Based on an idea of the so-called breakup fusion (BF) reaction, several authors derived closed formulas for the singles cross section of the particles that are emitted. There have been presented, however, two conflicting cross section formulas for the same

Ricardo Camanho Mastroleo

1987-01-01

138

BNS damping of beam breakup instability.  

National Technical Information Service (NTIS)

The author studies BNS damping of the beam breakup instability in a simple model assuming a constant beam energy, flat bunch distribution, and a smooth transverse focusing. The model allows an analytic solution for a constant and linear wake functions. Sc...

G. V. Stupakov

1997-01-01

139

Bubble Dynamics and Breakup in Straining Flows  

Microsoft Academic Search

The dynamics and breakup of a bubble in axisymmetric flow fields has been investigated using numerical and analytical techniques. In particular, the transient bubble deformation, oscillation, and overshoot effects are considered in conjunction with the existence of steady-state solutions. To explore the dynamics of a bubble with a high degree of deformation, a numerical technique suitable for solving axisymmetric, unsteady

1988-01-01

140

Nuclear induced breakup of halo nuclei  

Microsoft Academic Search

We investigate the validity of approximations that are sometimes made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled-channels calculations, in which the nuclear couplings between continuum states are ignored, gives almost the same result as a first-order calculation. However, the couplings are much too strong to justify these approximations. This is demonstrated in

H. Esbensen; G. F. Bertsch

1999-01-01

141

Deuteron emission following 6He beta decay  

Microsoft Academic Search

The measured spectrum shape and branching ratio for deuteron emission following 6He beta decay are reproduced in a one-level R-matrix approximation, by including an external contribution to the beta decay matrix element that is calculated using wave functions with the correct asymptotic forms.

F. C. Barker

1994-01-01

142

Break-up of an air bubble in water: Memory of azimuthal asymmetry  

Microsoft Academic Search

Recent experiments showed that the break-up of an air bubble in water retains a detailed memory of asymmetries present in the initial shape [1]. To gain insight into the physical mechanism for this memory, we analyze how non-axisymmetric perturbations change the collapse dynamics of a cylindrical void in water. We also consider the effects of surface tension and viscous dissipation,

Laura Schmidt; Wendy Zhang

2006-01-01

143

Fusion and breakup of weakly bound nuclei  

NASA Astrophysics Data System (ADS)

In this review the phenomenon of heavy-ion fusion at low energies is discussed in detail, with special emphasis given to the fusion of loosely bound stable and unstable projectiles. Experimental results on fusion and breakup of systems such as 6Li, 7Li, 9Be, the two-neutron halo nuclei 6He, the one-neutron halo nucleus 11Be and the one-proton halo nucleus 8B on light, medium and heavy targets are reviewed. An extensive review of the experimental methods and techniques used to measure the fusion and the breakup cross section is also presented, and the experimental challenges encountered in the measurement of the fusion cross section of these systems are pointed out. The theoretical description of the fusion of these loosely bound nuclei with a variety of targets is reviewed. Approaches based on the dynamic polarization potential arising from the strong coupling of the entrance channel to the breakup channel, as well as the Continuum Discretized Coupled Channels method are described at length. In contrast to the fusion of tightly bound projectiles, where enhancement of the complete fusion cross section at sub-barrier energies has been confirmed in the past, the fusion of loosely bound nuclei may exhibit hindrance effects, whose intensity is directly related to the Q-value of the breakup channel. The flux which is removed from the complete fusion channel feeds into what came to be known as the incomplete fusion channel. The elastic scattering of these systems is shown to shed light into the nature of the breakup polarization effect responsible for the fusion hindrance.

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

2006-02-01

144

Cold nuclear matter effects on J/{psi} production as constrained by deuteron-gold measurements at {radical}(s{sub NN})=200 GeV  

SciTech Connect

We present a new analysis of J/{psi} production yields in deuteron-gold collisions at {radical}(s{sub NN})=200 GeV using data taken from the PHENIX experiment in 2003 and previously published in S. S. Adler et al. [Phys. Rev. Lett 96, 012304 (2006)]. The high statistics proton-proton J/{psi} data taken in 2005 are used to improve the baseline measurement and thus construct updated cold nuclear matter modification factors (R{sub dAu}). A suppression of J/{psi} in cold nuclear matter is observed as one goes forward in rapidity (in the deuteron-going direction), corresponding to a region more sensitive to initial-state low-x gluons in the gold nucleus. The measured nuclear modification factors are compared to theoretical calculations of nuclear shadowing to which a J/{psi} (or precursor) breakup cross section is added. Breakup cross sections of {sigma}{sub breakup}=2.8{sub -1.4}{sup +1.7} (2.2{sub -1.5}{sup +1.6}) mb are obtained by fitting these calculations to the data using two different models of nuclear shadowing. These breakup cross-section values are consistent within large uncertainties with the 4.2{+-}0.5 mb determined at lower collision energies. Projecting this range of cold nuclear matter effects to copper-copper and gold-gold collisions reveals that the current constraints are not sufficient to firmly quantify the additional hot nuclear matter effect.

Adare, A.; Bickley, A. A.; Ellinghaus, F.; Kinney, E.; Seele, J.; Wysocki, M. [University of Colorado, Boulder, Colorado 80309 (United States); Adler, S. S.; Aronson, S. H.; Azmoun, B.; Belikov, S.; David, G.; Desmond, E. J.; Franz, A.; Haggerty, J. S.; Harvey, M.; Johnson, B. M.; Kistenev, E.; Kroon, P. J.; Lynch, D.; Makdisi, Y. I. [Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)] (and others)

2008-02-15

145

Breakup of dense colloidal aggregates under hydrodynamic stresses.  

PubMed

Flow-induced aggregation of colloidal particles leads to aggregates with fairly high fractal dimension (df approximately 2.4-3.0) which are directly responsible for the observed rheological properties of sheared dispersions. We address the problem of the decrease in aggregate size with increasing hydrodynamic stress, as a consequence of breakup, by means of a fracture-mechanics model complemented by experiments in a multipass extensional (laminar) flow device. Evidence is shown that as long as the inner density decay with linear size within the aggregate (due to fractality) is not negligible (as for df approximately 2.4-2.8), this imposes a substantial limitation to the hydrodynamic fragmentation process as compared with nonfractal aggregates (where the critical stress is practically size independent). This is due to the fact that breaking up a fractal object leads to denser fractals which better withstand stress. In turbulent flows, accounting for intermittency introduces just a small deviation with respect to the laminar case, while the model predictions are equally in good agreement with experiments from the literature. Our findings are summarized in a diagram for the breakup exponent (governing the size versus stress scaling) as a function of fractal dimension. PMID:19658503

Zaccone, Alessio; Soos, Miroslav; Lattuada, Marco; Wu, Hua; Bäbler, Matthäus U; Morbidelli, Massimo

2009-06-03

146

Nuclear induced breakup of halo nuclei  

SciTech Connect

We investigate the validity of approximations that are sometimes made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled-channels calculations, in which the nuclear couplings between continuum states are ignored, gives almost the same result as a first-order calculation. However, the couplings are much too strong to justify these approximations. This is demonstrated in the frozen limit of a semiclassical description, where one can compare to exact results. We find in this limit that the one-neutron removal cross section of {sup 11}Be obtained in the approximate treatment is much larger than the exact result. This trend is also indicated at low energy by comparing a perturbative calculation of the breakup of {sup 8}B to the result of a more realistic treatment, which evolves the wave function of the valence proton essentially to all orders in the target fields. {copyright} {ital 1999} {ital The American Physical Society}

Esbensen, H. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bertsch, G.F. [Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195 (United States)

1999-06-01

147

Nuclear induced breakup of halo nuclei  

NASA Astrophysics Data System (ADS)

We investigate the validity of approximations that are sometimes made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled-channels calculations, in which the nuclear couplings between continuum states are ignored, gives almost the same result as a first-order calculation. However, the couplings are much too strong to justify these approximations. This is demonstrated in the frozen limit of a semiclassical description, where one can compare to exact results. We find in this limit that the one-neutron removal cross section of 11Be obtained in the approximate treatment is much larger than the exact result. This trend is also indicated at low energy by comparing a perturbative calculation of the breakup of 8B to the result of a more realistic treatment, which evolves the wave function of the valence proton essentially to all orders in the target fields.

Esbensen, H.; Bertsch, G. F.

1999-06-01

148

Exclusive nuclear reactions: Can you count on the deuteron  

SciTech Connect

Three of the simplest nuclear reactions -- (1) electron-deuteron elastic scattering, (2) electro-disintegration of the deuteron near threshold and at high momentum transfer, and (3) photodisintegration of the deuteron at high energy -- were believed to have unique signatures for OCD effects in nuclei. The progress in the past few years with regard to these reactions will be traced and the results will be compared with recent theoretical predictions. 36 refs., 12 figs., 1 tab.

Holt, R.J.

1991-01-01

149

The tab method for numerical calculation of spray droplet breakup  

SciTech Connect

The authors present a method for calculating drop aerodynamic breakup in engine sprays. A short history is first give of the major milestones in the development of the stochastic particle method for calculating liquid fuel sprays. The most recent advance has been the discovery of the importance of drop breakup in engine sprays. They present a new method, called the TAB method, for calculating drop breakup. Some theoretical properties of the method are derived; its numerical implementation in the computer program KIVA is described; and comparisons are presented between TAB-method calculations and experiments and calculations using another breakup model.

O'Rourke, P.J.; Amsden, A.A.

1987-01-01

150

Numerical investigation on the primary breakup of an inelastic non-Newtonian liquid jet with inflow turbulence  

NASA Astrophysics Data System (ADS)

Direct Numerical Simulations of the primary breakup of an inelastic non-Newtonian liquid jet with inflow turbulence are presented in this paper. The jet's structure, surface behavior, non-Newtonian characteristics as well as its specific breakup mechanism are investigated and discussed. The shear thinning viscosity of the liquid phase plays an important role during jet injection resulting in circumferential rotation of interfacial waves. Streamwise contra-rotating vortex pairs as well as triple vortex structures are observed in the liquid phase. The local Ohnesorge number, which has a branch-structure distribution in the liquid phase before disintegration, is found to be 30% smaller in regions near the nozzle exit and in the shear layer than in the jet tip, suggesting a clear non-Newtonian influence. A cavity breakup mechanism for this type of non-Newtonian jet is identified and explained, giving a new perspective for jet disintegration analysis.

Zhu, Chengxiang; Ertl, Moritz; Weigand, Bernhard

2013-08-01

151

Recent Breakups in the Asteroid Belt  

NASA Astrophysics Data System (ADS)

Much of what we see in the asteroid belt today is a consequence of past collisions, which shaped the size-frequency distribution of asteroids and led to their heavily-cratered surfaces. Perhaps the most remarkable features of the belt are the asteroid families [1]. An asteroid family is a group of asteroid fragments with similar orbits and spectra produced by a collisional breakup of a large parent body. More than fifty families have been identified to date in the main belt [2]. These structures, when properly analyzed, hold important clues to the interior structure of asteroids, the physics of large scale collisions, and the overall evolution of the main belt since its formation [3]. Most of the known families are very old and thus have experienced significant dynamical and collisional erosion since their formation. This makes it difficult to clearly distinguish between features produced by the original breakup and those produced by on-going processes. Recent dynamical studies, however, have identified several asteroid families that are extremely young: the Iannini, Karin and Veritas families apparently formed at <5, 5.8 and 8.3 Ma, respectively [4,5]. These families represent nearly pristine examples of ejected fragments produced by disruptive asteroid collisions, because the observed remnants of recent breakups have apparently suffered limited dynamical and collisional erosion. Here we will discuss how studies of young asteroid families help us glean insights into the physics of large scale collisions, dynamical processes that affect small bodies in the Solar System, and the surface and interior properties of asteroids. [1] Hirayama, 1918, AJ 31, 185--188. [2] Zappala et al., 2002, In Asteroids III, pp. 619-629. [3] Bottke et al., 2005, Icarus, 175, 111-140. [4] Nesvorny et al., 2002, Nature 417, 720--722. [5] Nesvorny et al., 2003, ApJ 591, 486--497.

Nesvorny, D.

2005-08-01

152

Study of the 6Li(n, ?)3H reaction via the 2H quasi-free break-up  

NASA Astrophysics Data System (ADS)

The quasi-free break-up of deuteron was used to study the neutron-induced 6Li + n reaction via the 2H(6Li, ?3H)p. The aim of the experiment was to check whether the deuteron can be considered as a source of virtual neutrons. This was done by studying the excitation function of the 6Li(n, ?)3H two-body reaction at low energy where the resonance corresponding to the excited level at 7.454 MeV of 7Li is present. Two experimental runs were performed at the Laboratori Nazionali del Sud (LNS) in Catania, Italy. In both experiments, the energy and the position of the outgoing ? and 3H particles were measured and the kinematics were reconstructed assuming a proton as the third particle. The quasi-free events were selected in order to reconstruct the 6Li(n, ?)3H cross section in the center-of-mass energy by using the plane wave impulse approximation approach. The obtained cross section is in very good agreement with the directly measured one.

Gulino, M.; Spitaleri, C.; Cherubini, S.; Crucillà, V.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Sergi, M. L.; Tumino, A.; Chengbo, Li; Elekes, Z.; Somorjai, E.; Burjan, V.; Kroha, V.; Mukhamedzhanov, A.

2010-12-01

153

He6 breakup dynamic polarization potential reexamined  

NASA Astrophysics Data System (ADS)

The dynamic polarization potential contribution to the effective interaction between He6 and Pb208 at 27 MeV, due to breakup channels, is recalculated exploiting a recently developed improved model for He6. The most general features of the long-range attractive and absorptive components remain the same as were found in an earlier study, but the asymptotic magnitudes are reduced by factors of about 2.5 and 4.5, respectively. We draw conclusions from these results, as well as from further calculations at 22 MeV, closer to the Coulomb barrier, and at 32 MeV.

Mackintosh, R. S.; Keeley, N.

2009-01-01

154

Multipass Beam Breakup in Energy Recovery Linacs  

SciTech Connect

This paper is a compilation of several presentations on multipass beam breakup (BBU) in energy recovery linacs (ERL) given at the 32nd Advanced ICFA Beam Workshop on ERLs. The goal of this paper is to summarize the progress achieved in analytical, numerical, and experimental studies of the instability and outline available and proposed BBU mitigation techniques. In this paper, a simplified theory of multipass BBU in recirculating linacs is presented. Several BBU suppression techniques and their working principles are discussed. The paper presents an overview of available BBU codes. Results of experimental studies of multipass BBU at the Jefferson Laboratory (JLab) FEL Upgrade are described.

Eduard Pozdeyev; Christopher Tennant; Joseph Bisognano; M Sawamura; R. Hajima; T.I. Smith

2005-03-19

155

Pangea formation and break-up  

NASA Astrophysics Data System (ADS)

The Palaeozoic was dominated by the great continent Gondwana. Other continents included Laurentia and Baltica that fused (together with Avalonia), forming Laurussia after the closure of the Iapetus Ocean, making the second largest continental entity in the Silurian. By the Carboniferous at around 320 Ma, Gondwana and Laurussia amalgamated, forming Pangea that was surrounded by the Panthalassa and Paleotethys Oceans. Pangea did not include all continental crust. For example, the South and North China Blocks were not part of Pangea at any given time and also during the Early Permian phase of Pangea assembly, the Neotethys opened, and Cimmerian terranes drifted away from the NE Gondwana margin while the Paleotethys was being subducted beneath Eurasia. An additional, unresolved question is whether Siberia was fully joined to Pangea before the eruption of the Siberian Traps (251 Ma). Practically all Permian Pangea reconstructions using palaeomagnetic data result in considerable overlap between Laurussia and Gondwana, as both are straddling the equator, and thus Gondwana must be moved sideways to avoid this overlap, and at a younger time displaced dextrally to achieve the well established starting point for Pangea break-up in the Jurassic. Octupole contributions can eliminate this overlap, but just by changing the internal fits within Laurussia and correcting all detrital sedimentary poles for inclination shallowing using a use a benchmark flattening (f) value of 0.6 (unless previously corrected using either the inclination-elongation method or anisotropy of magnetic susceptibility information) lead to an almost perfect Pangea-A type fit. Pangea break-up profoundly changed our planet, and the most important phase of break-up started when the Central Atlantic Ocean opened (ca. 195 Ma). Perhaps not coincidentally, the region where the Atlantic spreading started was preceded by the emplacement of the Central Atlantic Magmatic Province, one of the largest large igneous provinces (LIPs). Also the Early Permian opening of the Neotethys was preceded by a LIP, the Panjal Traps at around 285 Ma. Pangea was centred above the African large low shear velocity province (LLSVP) at the core-mantle boundary. The African LLSVP has been stable for at least 300 Myrs. Its edges, the plume generation zones, are favourable sites for the initiation of large plumes rising through the mantle and causing extensive upper mantle melting and eruption of LIPs that contributed to the break-up of Pangea.

Torsvik, Trond

2013-04-01

156

Pion-less effective field theory on low-energy deuteron electrodisintegration  

SciTech Connect

In view of its relation to Big Bang nucleosynthesis and a reported discrepancy between nuclear models and data taken at S-DALINAC, electro-induced deuteron breakup {sup 2}H(e,e{sup '}p)n is studied at momentum transfer q<100 MeV and close to threshold in the low-energy nuclear effective field theory without dynamical pions, EFT({pi} /). The result at next-to-next-to-leading order (N{sup 2}LO) for electric dipole currents and at next-to-leading order (NLO) for magnetic ones converges order-by-order better than quantitatively predicted and contains no free parameter. It is at this order determined by simple, well-known observables. Decomposing the triple differential cross section into the longitudinal-plus-transverse (L+T), transverse-transverse (TT), and longitudinal-transverse interference (LT) terms, we find excellent agreement with a potential-model calculation by Arenhoevel and co-workers, based on the Bonn potential. Theory and data also agree well on {sigma}{sub L+T}. There is however no space on the theory side for the discrepancy of up to 30%(3{sigma}) between theory and experiment in {sigma}{sub LT}. From universality of EFT({pi} /), we conclude that no theoretical approach with the correct deuteron asymptotic wave function can explain the data. Undetermined short-distance contributions that could affect {sigma}{sub LT} enter only at high orders (i.e., at the few-percent level). We notice some issues with the kinematics and normalization of the data reported.

Christlmeier, Stefan [Institut fuer Theoretische Physik (T39), Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany); Griesshammer, Harald W. [Institut fuer Theoretische Physik (T39), Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany); Center for Nuclear Studies, Department of Physics, The George Washington University, Washington DC 20052 (United States)

2008-06-15

157

Electromagnetic form factors of the deuteron and QCD sum rules  

SciTech Connect

In the framework of the method of finite-energy QCD sum rules we calculate the electromagnetic form factors of the deuteron at intermediate momentum transfer 1approx. deuteron by the QCD sum-rule method.

Larin, S.A.; Matveev, V.A.

1987-07-01

158

Toroidal quadrupole form factor of the deuteron  

NASA Astrophysics Data System (ADS)

We calculate the toroidal quadrupole moment and form factor of the deuteron, which violate time-reversal symmetry but conserve parity, at leading order in two-flavor chiral effective field theory with perturbative pion exchange. We take into account time-reversal and parity violation owing to the QCD vacuum angle combined with parity violation resulting from the weak interaction in the Standard Model. We also consider time-reversal and parity violation that at the quark-gluon level results from effective dimension-six operators originating from physics beyond the Standard Model.

Mereghetti, E.; de Vries, J.; Timmermans, R. G. E.; van Kolck, U.

2013-09-01

159

Nuclear effects in the deuteron structure function  

NASA Astrophysics Data System (ADS)

An analysis of nuclear effects in the deuteron quark distributions is carried out in connection with the Gottfried sum rule (GSR), the Drell-Yan proton-neutron asymmetry and the Bjorken sum rule (BSR). It is shown that the small amount of nuclear effects necessary to saturate the GSR experimental data modifies the Drell-Yan asymmetry in an entirely different way as an asymmetric sea does. These effects are of little consequence in the convergence of the BSR to the expected value.

Epele, L. N.; Fanchiotti, H.; Canal, C. A. García; Sassot, R.

1992-08-01

160

Deuteron dipole polarizabilities and sum rules  

SciTech Connect

The scalar, vector, and tensor components of the (generalized) deuteron electric dipole polarizability are calculated, as well as their logarithmic modifications. Several of these quantities arise in the treatment of the nuclear corrections to the deuterium Lamb shift and the deuterium hyperfine structure. A variety of second-generation potential models are used, and a (subjective) error is assigned to the calculations. The zero-range approximation is used to analyze a subset of the results, and a simple relativistic version of this approximation is developed.

Friar, J.L.; Payne, G.L. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

2005-07-01

161

MEC and relativistic effects in the deuteron  

NASA Astrophysics Data System (ADS)

This talk shows recent results for the contributions of Meson Exchange Currents (MEC) and relativistic effects on the elastic electron scattering structure functions of the deuteron in the context of several recent models. These calculations show that these effects are substantial at 1 GeV2 and above and that care must be taken in consistently treating these effects within the context of a given model. The current data suggest that the contributions to the structure functions from the ??? meson exchange current must be small. .

van Orden, J. W.

2000-06-01

162

Some features of spray breakup in effervescent atomizers  

Microsoft Academic Search

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray

Hrishikesh P. Gadgil; B. N. Raghunandan

2011-01-01

163

Some features of spray breakup in effervescent atomizers  

Microsoft Academic Search

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray

Hrishikesh P. Gadgil; B. N. Raghunandan

2010-01-01

164

Dynamics and Breakup of Pulse Microjets of Polymeric Liquids  

Microsoft Academic Search

The possibilities of controlling the dynamics and breakup of pulsed low-viscosity liquid microjets by means of small amounts of polymeric additives are considered. Significant differences between the breakup of pulse jets of Newtonian and viscoelastic polymeric liquids are recorded by means of high-speed photography. In flight a standard Newtonian fluid jet fragments into many secondary droplets. Depending on the molecular

A. V. Bazilevskii; J. D. Meyer; A. N. Rozhkov

2005-01-01

165

Breakup channels for C12 triple-? continuum states  

NASA Astrophysics Data System (ADS)

The triple-?-particle breakup of states in the triple-? continuum of C12 has been investigated by way of coincident detection of all three ? particles of the breakup. The states have been fed in the ? decay of N12 and B12, and the ? particles measured using a setup that covers all of the triple-? phase space. Contributions from the breakup through the Be8(0+) ground state as well as other channels—interpreted as breakup through excited energies in Be8—have been identified. Spins and parities of C12 triple-? continuum states are deduced from the measured phase-space distributions for breakup through Be8 above the ground state by comparison to a fully symmetrized sequential R-matrix description of the breakup. At around 10 MeV in C12, the breakup is found to be dominated by 0+ strength breaking up through the ghost of the Be8(0+) ground state with L=0 angular momentum between the first emitted ? particle and the intermediate Be8 nucleus. For C12 energies above the 12.7 MeV 1+ state, however, L=2 breakup of a C12 2+ state through the Be8(2+) excited state dominates. Furthermore, the possibility of a 2+ excited state in the 9-12 MeV region of C12 is investigated.

Diget, C. Aa.; Barker, F. C.; Borge, M. J. G.; Boutami, R.; Dendooven, P.; Eronen, T.; Fox, S. P.; Fulton, B. R.; Fynbo, H. O. U.; Huikari, J.; Hyldegaard, S.; Jeppesen, H. B.; Jokinen, A.; Jonson, B.; Kankainen, A.; Moore, I.; Nieminen, A.; Nyman, G.; Penttilä, H.; Pucknell, V. F. E.; Riisager, K.; Rinta-Antila, S.; Tengblad, O.; Wang, Y.; Wilhelmsen, K.; Äystö, J.

2009-09-01

166

University Students' Experiences of Nonmarital Breakups: A Grounded Theory  

ERIC Educational Resources Information Center

|Prior nonmarital breakup research has been focused on negative outcomes, rarely examining the personal growth aspects of this experience. In this study, we used a qualitative grounded theory methodology to explore the changes that university students reported experiencing as a result of a heterosexual nonmarital breakup and how those changes…

Hebert, Sarah; Popadiuk, Natalee

2008-01-01

167

Time-dependent analysis of the breakup of halo nuclei  

Microsoft Academic Search

The breakup of halo nuclei is studied by numerically solving the semiclassical time-dependent Schrödinger equation on an angular Lagrange mesh and on a quasiuniform radial mesh. The merits of different mesh choices and approximations of the time evolution operator are discussed. The numerical technique is applied to the breakup of the 11Be and 15C halo nuclei at energies around 70

P. Capel; D. Baye; V. Melezhik

2003-01-01

168

Nonperturbative time-dependent approach to breakup of halo nuclei  

Microsoft Academic Search

The time-dependent mesh method is proposed as an efficient tool for a quantitative analysis of the Coulomb breakup of halo nuclei. The approach allows a treatment of breakup reactions in the nonperturbative regime. It avoids any multipole expansion for the Coulomb interaction between the projectile and the target. Moreover, it permits using more general trajectories allowing an estimation of postacceleration

V. S. Melezhik; D. Baye

1999-01-01

169

Breakup Effects on University Students' Perceived Academic Performance  

ERIC Educational Resources Information Center

The Problem: Problems that might be expected to affect perceived academic performance were studied in a sample of 283 university students. Results: Breakup Distress Scale scores, less time since the breakup and no new relationship contributed to 16% of the variance on perceived academic performance. Variables that were related to academic…

Field, Tiffany; Diego, Miguel; Pelaez, Martha; Deeds, Osvelia; Delgado, Jeannette

2012-01-01

170

Breakup Effects on University Students' Perceived Academic Performance  

ERIC Educational Resources Information Center

|The Problem: Problems that might be expected to affect perceived academic performance were studied in a sample of 283 university students. Results: Breakup Distress Scale scores, less time since the breakup and no new relationship contributed to 16% of the variance on perceived academic performance. Variables that were related to academic…

Field, Tiffany; Diego, Miguel; Pelaez, Martha; Deeds, Osvelia; Delgado, Jeannette

2012-01-01

171

Three-dimensional simulation of primary break-up in a close-coupled atomizer  

NASA Astrophysics Data System (ADS)

Until now much of the modelling activity around close-coupled gas atomization has been mainly focused on gas-only flow with discrete phase interaction using Lagrangian-based models. However, this approach is unable to supply valuable information regarding the primary break-up mechanism of the melt being injected. Furthermore, much of existing numerical work is based on two-dimensional axisymmetric geometries, and therefore suffers the absence of three-dimensional flow features. In order to overcome these aspects the authors have carried out an analysis using a three-dimensional geometry by means of an Eulerian, Volume of Fluid, model to accurately present the early stages of melt stream behaviour at the atomizer's melt inlet. The study investigates the mechanisms associated with primary break-up, and the results obtained highlight three modes under which a close-coupled atomizer may operate.

Zeoli, N.; Tabbara, H.; Gu, S.

2012-09-01

172

The cometary breakup hypothesis re-examined  

NASA Astrophysics Data System (ADS)

The theory that a Chiron-like progenitor of both Comet Encke and the Tunguska cosmic body may have fragmented beginning around 22,000 years BP and that debris from this breakup was responsible for producing the high heavy metal concentrations observed in the Late Wisconin stage polar ice is shown to be incorrectly founded. This paper reexamines the geochemical comparison which Clube and Napier (1984) make between the composition of the Tunguska cosmic body and elemental abundances previously reported for a sample of Sn-rich dust retrieved from the Wisconsin section of the Camp Century ice core. No evidence is found that would link these two sources to a common origin. Thus the hypothesis that a cometary breakup was responsible for modulating the earth's climate and perpetuating the last ice age is unfounded. On the other hand, evidence is presented indicating that debris from the Tunguska explosion may be present in a firm layer at Dome C, East Antarctica. Analysis of the geochemical data for this stratum leads to an estimate of 10 to the 6th to 10 to the 7th t for the mass of the Tunguska body, in approximate agreement with previous determinations.

La Violette, P. A.

1987-02-01

173

Integral relations and the adiabatic expansion method for 1+2 reactions above the breakup threshold: Helium trimers with soft-core potentials  

NASA Astrophysics Data System (ADS)

The integral relations formalism introduced in [P. Barletta , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.103.090402 103, 090402 (2009); C. Romero-Redondo , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.83.022705 83, 022705 (2011)] and designed to describe 1+N reactions is extended here to collision energies above the threshold for the target breakup. These two relations are completely general, and in this work they are used together with the adiabatic expansion method for the description of 1+2 reactions. The neutron-deuteron breakup, for which benchmark calculations are available, is taken as a test of the method. The s-wave collision between the 4He atom and 4He2 dimer above the breakup threshold and the possibility of using soft-core two-body potentials plus a short-range three-body force will be investigated. Comparisons to previous calculations for the three-body recombination and collision dissociation rates will be shown.

Garrido, E.; Romero-Redondo, C.; Kievsky, A.; Viviani, M.

2012-11-01

174

Hydro and thermodynamics of the subcavitation breakup of emulsions in the valve gap of a homogenizer  

Microsoft Academic Search

The hydrodynamic features of valve homogenizers for the mechanical treatment of emulsions (breakup of dispersion medium) are\\u000a considered. Distributions of the hydro- and thermodynamic characteristics of flow are derived based on the hypothesis of the\\u000a discreteness of the liquid phase. The existence of ultralow-pressure zones in the cavitation regions is theoretically proven.\\u000a The thermodynamic characteristics of emulsion drops in an

V. G. Kulenko; E. A. Fialkova; V. I. Baronov

2009-01-01

175

General design of the International Fusion Materials Irradiation Facility deuteron injector: Source and beam line  

SciTech Connect

In the framework of the International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities (IFMIF-EVEDA) project, CEA/IRFU is in charge of the design and realization of the 140 mA cw deuteron Injector. The electron cyclotron resonance ion source operates at 2.45 GHz and a 4 electrode extraction system has been chosen. A 2 solenoid beam line, together with a high space charge compensation have been optimized for a proper beam injection in the 175 MHz radio frequency quadrupole. The injector will be tested with proton and deuteron beam production either in pulsed mode or in cw mode on the CEA-Saclay site before to be shipped to Japan. Special attention was paid to neutron emission due to (d,D) reaction. In this paper, the general IFMIF Injector design is reported, pointing out beam dynamics, radioprotection, diagnostics, and mechanical aspects.

Gobin, R.; Blideanu, V.; Bogard, D.; Bourdelle, G.; Chauvin, N.; Delferriere, O.; Girardot, P.; Jannin, J. L.; Langlois, S.; Loiseau, D.; Pottin, B.; Rousse, J.-Y.; Senee, F. [Commissariat a l'Energie Atomique, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France)

2010-02-15

176

Measurement of T20(90°) in the 1H(d-->,?)3He reaction below deuteron breakup threshold  

NASA Astrophysics Data System (ADS)

The tensor analyzing powers of the 1H(d-->,?)3He reaction are sensitive to the tensor component of the nucleon-nucleon force, which mixes the L=2 D state into the 3He ground state wave function. Modern Faddeev calculations of this reaction allow a quantitative comparison to the parametrization of the tensor force in the trinucleon system. The T20 analyzing power was measured at an incident beam energy of 5.25 MeV and a laboratory angle of 90° (?c.m.=92.9°), where the comparison to theory is especially rigorous. The measured value of T20(90°lab) is -0.035+/-0.004, which differs by ~=3? from a recent Faddeev calculation which uses the separable expansion of the Paris potential.

Browne, K. P.; Pitts, W. K.; Smith, M. K.; McAninch, J. E.; Knutson, L. D.

1996-10-01

177

Cross section and T/sub 20/ in 0/sup 0/ deuteron breakup at 2. 1 GeV  

SciTech Connect

Cross sections and T/sub 20/ analyzing powers for dA..-->..pX are presented. A shoulder in the cross section previously reported at higher energies and for carbon is observed for H, C, and Ti at the same d-c.m.-frame proton momentum q = 0.35 GeV/c. At q<0.2 GeV/c both cross-section and T/sub 20/ data depend only weakly upon the target atomic number A. Calculations in the plane-wave impulse approximation with several NN wave functions, and with either a ..delta delta.. or a six-quark component added, are discussed.

Perdrisat, C.F.; Punjabi, V.; Lyndon, C.; Yonnet, J.; Beurtey, R.; Boivin, M.; Boudard, A.; Didelez, J.P.; Frascaria, R.; Reposeur, T.; and others

1987-12-21

178

Breakup of an oxygen nucleus to light fragments of mass number in the range A ? 4 in 16O p interactions at a momentum of 3.25 GeV/ c per nucleon  

NASA Astrophysics Data System (ADS)

New experimental data on the correlations of the yields of 4He and 2H nuclei in semi-inclusive reactions involving by the production of 3He and 3H mirror nuclei in 16O p collisions at a momentum of 3.25 GeV/ c per nucleon are presented. The mean multiplicities of protons and neutrons appearing as fragments are found to be independent of the number of associated deuterons, this indicating that a considerable part of these fragments originate from the breakup of the alpha-particle clusters forming the oxygen nucleus.

Olimov, K.; Glagolev, V. V.; Gulamov, K. G.; Kurbanov, A.; Lutpullaev, S. L.; Olimov, A. K.; Petrov, V. I.; Yuldashev, A. A.

2012-04-01

179

Coulomb breakup of 7Li for nuclear astrophysics  

NASA Astrophysics Data System (ADS)

A new Coulomb breakup experiment was performed for 7Li with an improved experimental technique and theoretical treatment. Energy spectra of ? particles and tritons were examined to find the signature of post-Coulomb acceleration in the breakup of 7Li at E?t=0. The data revealed the delayed nature of nonresonant breakup of astrophysical relevance that stems from quantum tunneling. Semiclassical discussions are presented of the lifetime of continuum states in 7Li and distortion of relative kinetic energies between ? and t by post-Coulomb acceleration. Dynamical calculations of Coulomb breakup were performed by solving a time-dependent Schrödinger equation. A simple potential model of 7Li was employed. The dynamical calculations reasonably reproduced experimental cross sections for both resonant and nonresonant breakup with two key ingredients: higher order effects and mixture of E1 and E2 multipoles. Considering the dominant role of the first-order E1 nature in adiabatic Coulomb breakup, cross sections in the v?>=vt branch at 7 °-15 ° for 64Zn and 90Zr were used to deduce astrophysical S factors S(E) for t(?,?)7Li. They exhibit a moderate energy dependence at small energies. The strongly energy-dependent S(E) resulted from the previous Coulomb breakup experiment based on cross sections with v?<=vt they are most likely Coulomb distorted and are revised in the present work.

Tokimoto, Y.; Utsunomiya, H.; Yamagata, T.; Ohta, M.; Lui, Y.-W.; Schmitt, R. P.; Typel, S.; Aoki, Y.; Ieki, K.; Katori, K.

2001-03-01

180

Capillary breakup of discontinuously rate thickening suspensions.  

PubMed

Using discontinuously rate thickening suspensions (DRTS) as a model system, we show that beads-on-a-string morphologies can arise as a result of external viscous drag acting during capillary-driven breakup of a non-Newtonian fluid. To minimize the perturbative effect of gravity, we developed a new experimental test platform in which the filament is supported in a horizontal position at the surface of an immiscible oil bath. We show that the evolution of thin DRTS filaments during the capillary thinning process is well described by a set of one-dimensional slender filament equations. The strongly rate-dependent rheology of the test fluid and the aspect ratio of the filament couple to control the thinning dynamics and lead to a simple criterion describing the localized arrest of the capillary thinning process and the subsequent formation of complex, high aspect ratio beads-on-a-string structures. PMID:23909338

Zimoch, Pawel J; McKinley, Gareth H; Hosoi, A E

2013-07-19

181

Transfer and breakup reactions at intermediate energies  

SciTech Connect

The origin of the quasi-elastic peak in peripheral heavy-ion reactions is discussed in terms of inelastic scattering and transfer reactions to unbound states of the primary projectile-like fragment. The situation is analogous to the use of reverse kinematics in fusion reactions, a technique in which the object of study is moving with nearly the beam velocity. It appears that several important features of the quasi-elastic peak may be explained by this approach. Projectile-breakup reactions have attractive features for the study of nuclear structure. They may also be used to determine the partition of excitation energy in peripheral reactions. At intermediate energies, neutron-pickup reactions leading to four-body final states become important. Examples of experiments are presented that illustrate these points. 15 refs., 14 figs.

Stokstad, R.G.

1986-04-01

182

Two-component model for the deuteron electromagnetic structure  

SciTech Connect

We suggest a simple phenomenological parametrization for the deuteron electromagnetic structure, and show that a good fit on all available data for the three deuteron electromagnetic form factors (in the range Q{sup 2}{<=}2 GeV{sup 2}) can be obtained with a small number of parameters. The present description of the deuteron is based on two components with different radii, one corresponding to two nucleons separated by {approx_equal}2 fm, and a standard isoscalar contribution, saturated by {omega} and {phi} mesons, only.

Tomasi-Gustafsson, E.; Gakh, G.I.; Adamuscin, C. [DAPNIA/SPhN, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex (France)

2006-04-15

183

Possible PET isotope production using linear deuteron accelerators  

NASA Astrophysics Data System (ADS)

PET isotopes like 11C and 18F may be produced in deuteron-induced reactions using linear deuteron accelerators for energies 2 2.5 MeV. It is shown that the yield of PET isotopes in reactions 10B(d,n)11C and 20Ne(d,a)18F may be higher than the yield of the same isotopes in proton-induced reactions at higher energies, where protons are accelerated by a cyclotron. The lower cost and smaller size of linear accelerators make deuteron-induced reactions very promising for industrial PET production.

Volkovitsky, P.; Gilliam, D. M.

2005-08-01

184

Calculating Beam Breakup in Superconducting Linear Accelerators  

SciTech Connect

As the intensity of a particle beam passing through a linear accelerator is raised, interactions between particles play an increasingly prominent role in determining the overall dynamics of the beam. These many body effects, known collectively as beam breakup, tend to degrade the quality of the transported beam, and hence they must be calculated to accurately predict the evolution of the beam as it traverses the accelerator. Several codes which compute various collective effects have been developed and used to simulate the dynamics of beams passing through superconducting accelerator structures. All the codes use the same basic algorithm: the beam is tracked through elements giving the focusing forces on the particles, and at the appropriate locations in the linac, localized forces are impressed on the particles which model the electromagnetic interactions. Here, a difficulty is that the usual ''Coulomb'' interaction between particles is changed by the electromagnetic environment of the accelerator. By such calculations it has been shown that recirculating linear accelerators such as the one being built at the Continuous Electron Beam Accelerator Facility (CEBAF) should remain stable against multipass beam breakup instability as long as the average current does not exceed about 20 mA, that the beam quality at CEBAF will be degraded when the single bunch charge approaches 10{sup 9} electrons, and that the beam quality of superconducting linacs that are optimized for high current transport begins to decrease at around 10{sup 10} electrons per bunch. The latter result is of interest to individuals who would use superconducting linacs as beam sources for free electron lasers or for superconducting colliders for high energy physics research.

Geoffrey Krafft; Joseph Bisognano; Sharon Laubach

1990-02-09

185

Age of Seychelles India break-up  

NASA Astrophysics Data System (ADS)

Many continental flood basalt provinces are spatially and temporally linked with continental break-up. Establishing the relative timing of the two events is a key step in determining their causal relationship. Here we investigate the example of the Deccan Traps and the separation of India and the Seychelles. Whilst there has been a growing consensus as to the age of the main phase of the Deccan emplacement (65.5 ± 1 Ma, chron 29r), the age of the rifting has remained unclear. We resolve this issue through detailed seafloor magnetic anomaly modeling (supported by wide-angle and reflection seismic results) of the north Seychelles and conjugate Laxmi Ridge/Gop Rift margins, and geochemistry and 40Ar/39Ar geochronology of rocks from the north Seychelles margin. We show that syn-rift volcanics offshore the Seychelles Islands in the form of seaward-dipping reflectors were most likely erupted during chron 28n, and the first organized seafloor spreading at the Carlsberg Ridge also initiated during this chron at 63.4 Ma. The severing of the Seychelles occurred by a south-eastward ridge propagation that was completed by the start of chron 27n (~ 62 Ma). A brief, pre-28r phase of seafloor spreading occurred in the Gop Rift, possibly as early as 31r 32n (~ 71 Ma). Initial extension at the margin therefore preceded or was contemporaneous with the Deccan emplacement, and separation of the Seychelles was achieved less than 3.5 Ma afterwards. This is the shortest time interval between flood basalt emplacement and break-up yet reported for any continental flood basalt-rifted margin pair. A contributing factor to the apparently short interval in the Deccan case may be that rifting occurred by a ridge jump into already thinned continental lithosphere. However, we conclude that external plate-boundary forces, rather than the impact of a mantle plume, were largely responsible for the rifting of the Seychelles from India.

Collier, J. S.; Sansom, V.; Ishizuka, O.; Taylor, R. N.; Minshull, T. A.; Whitmarsh, R. B.

2008-07-01

186

The Mesozoic breakup of the Weddell Sea  

NASA Astrophysics Data System (ADS)

A new set of rotations is presented that describes a refined model for the early opening of the Weddell Sea between South America and Antarctica and the Mesozoic breakup of Gondwana. Published high-resolution aeromagnetic data from the eastern Weddell Sea and additional track data farther west in the Weddell Sea were used to constrain the new model for the opening of the Weddell Sea. Rotation parameters derived for the South America-Antarctica spreading regime were combined with constraints on the South America-Africa and Africa-Antarctica spreading systems to calculate a refined model for the Mesozoic breakup of Gondwana. Thereafter, at the time when the north-south oriented separation between Africa and Antarctica is initiated by rifting in the Somali and Mozambique basins (˜167 Ma), stretching and extension takes place in a basin comprising continental crust of the Filchner-Ronne Shelf, the Falkland Island block and the Maurice Ewing Bank. The first true ocean floor in the Weddell Sea is formed at about 147 Ma, after rifting between the Antarctic Peninsula and southernmost South America occurred. This is about 15-20 Myr later than previously estimated. Separation between South America and Antarctica takes place at slow spreading rates (14-12 mm/yr half rate) from 147 to 122 Ma and after 122 Ma (M2) at ultraslow spreading rates (˜8 mm/yr half rate) with little change in the NNW spreading direction throughout this time. A revised age range is proposed for the formation of the Explora Wedge (150-138 Ma), which is more than 30 Myr later than previously published (˜183 Ma).

KöNig, Matthias; Jokat, Wilfried

2006-12-01

187

New description of four-body break-up reaction  

SciTech Connect

We present a new method of smoothing discrete breakup cross sections calculated by the method of continuum-discretized coupled-channels. In the four-body breakup reaction of {sup 12}C({sup 6}He, nn{sup 4}He) at E{sub in} = 229.8 MeV, the continuous breakup cross section is evaluated as a function of the excitation energy of {sup 6}He. Convergence of the cross section with respect to extending the modelspace is also confirmed.

Matsumoto, T. [Meme Media Laboratory, Hokkaido University, Sapporo 060-8628 (Japan); Kato, K. [Division of Physics, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Yahiro, M. [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2011-06-28

188

The TAB method for numerical calculation of spray droplet breakup  

NASA Astrophysics Data System (ADS)

A short history is given of the major milestones in the development of the stochastic particle method for calculating liquid fuel sprays. The most recent advance has been the discovery of the importance of drop breakup in engine sprays. A new method, called TAB, for calculating drop breakup is presented. Some theoretical properties of the method are derived; its numerical implementation in the computer program KIVA is described; and comparisons are presented between TAB-method calculations and experiments and calculations using another breakup model.

Orourke, P. J.; Amsden, A. A.

189

Deuteron forward photodisintegration: meson currents and relativity  

SciTech Connect

The few-nucleon problem in nuclear physics and the few-electron problem in atomic physics are shown to possess similarities. Relativistic aspects of the latter are reviewed. The radiative decay of the /sup 3/P/sub 1/ excited state of helium-like ions to the /sup 1/S/sub 0/ ground state is shown to be a theoretical analogue of low-energy deuteron forward photodisintegration. Both have large relativistic components. The extended Siegert's theorem, which permits application of Siegert's technique to arbitrary photon wave lengths, is applied to both transitions. Physical arguments for the two processes are stressed, and the relevance of interaction currents is discussed. 28 references.

Friar, J.L.

1983-01-01

190

Muon-Deuteron Deep Inelastic Scattering  

Microsoft Academic Search

We have measured deep inelastic muon-deuteron scattering in the range 0.4

I. J. Kim; A. Entenberg; H. Joestlein; K. Koenigsmann; I. Kostoulas; A. C. Melissinos; E. Aslanides; L. Lederman; P. Limon; M. May; P. Rapp; H. Gittleson; T. Kirk; M. Murtagh; M. J. Tannenbaum; J. Sculli; T. White; T. Yamanouchi

1974-01-01

191

Nucleon and Deuteron Form Factors from BLAST  

NASA Astrophysics Data System (ADS)

The BLAST experiment was designed to study in a systematic manner the spin-dependent, electromagnetic interaction on hydrogen and deuterium. Measuring only asymmetries in electron scattering with respect to the beam helicity, target spin, or both; the BLAST experiment was able to extract information on nucleon and deuteron form factors independent of beam intensity or target density. By further forming ``super-ratios'' of asymmetries, measurements were possible independent of beam and target polarization thus reducing uncertainties due to these quantities as well. Some of the form factor results from BLAST will be briefly presented here. Also, in response to observed discrepancies between polarization measurements and those obtained using traditional Rosenbluth separation techniques a proposed experiment, OLYMPUS, which will use the BLAST detector to measure the two photon contribution to elastic electron scattering will also be presented.

Hasell, D. K.

2009-12-01

192

Deuterons and flow: At intermediate AGS energies  

SciTech Connect

A quantitative model, based on hadronic physics and Monte Carlo cascading is applied to heavy ion collisions at BNL-AGS and BEVALAC energies. The model was found to be in excellent agreement with particle spectra where data previously existed, for Si beams, and was able to successfully predict the spectra where data was initially absent, for Au beams. For Si + Au collisions baryon densities of three or four times the normal nuclear matter density ({rho}{sub 0}) are seen in the theory, while for Au + Au collisions, matter at densities up to 10 {rho}{sub 0} is anticipated. The possibility that unusual states of matter may be created in the Au beams and potential signatures for its observation, in particular deuterons and collective flow, are considered.

Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States); Pang, Y. [Brookhaven National Lab., Upton, NY (United States)]|[Columbia Univ., New York, NY (United States); Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States)

1996-06-01

193

Deuteron Acceleration and Fusion Neutron Production in Z-pinch plasmas  

NASA Astrophysics Data System (ADS)

Fusion neutron measurements were carried out on the S-300 generator (Kurchatov Institute, Moscow). We tried deuterated fibers, various types of wire arrays imploding onto a deuterated fiber, and deuterium gas puffs as Z-pinch loads. On the current level of 2 MA, the peak neutron yield of 1010 was achieved with a deuterium gas-puff. The neutron and deuteron energy spectra were quite similar in various types of Z-pinch configurations. The broad width of radial neutron spectra implied a high radial component of deuteron velocity. On the basis of neutron measurements, we concluded that neutron production mechanism is connected with the study of plasma voltage. It means that the acceleration of fast deuterons is not a secondary process but it reflects the global dynamics of Z-pinch plasmas. For this reason it is useful to add deuterium as a ``tracer'' in Z-pinch loads more often. For instance, it seems attractive to prepare wire-arrays from deuterated metal wires such as Pd.

Klir, D.; Kravarik, J.; Kubes, P.; Rezac, K.; Ananeev, S. S.; Bakshaev, Yu. L.; Blinov, P. I.; Chernenko, A. S.; Kazakov, E. D.; Korolev, V. D.; Ustroev, G. I.

2009-01-01

194

Deuteron Acceleration and Fusion Neutron Production in Z-pinch plasmas  

SciTech Connect

Fusion neutron measurements were carried out on the S-300 generator (Kurchatov Institute, Moscow). We tried deuterated fibers, various types of wire arrays imploding onto a deuterated fiber, and deuterium gas puffs as Z-pinch loads. On the current level of 2 MA, the peak neutron yield of 10{sup 10} was achieved with a deuterium gas-puff. The neutron and deuteron energy spectra were quite similar in various types of Z-pinch configurations. The broad width of radial neutron spectra implied a high radial component of deuteron velocity. On the basis of neutron measurements, we concluded that neutron production mechanism is connected with the study of plasma voltage. It means that the acceleration of fast deuterons is not a secondary process but it reflects the global dynamics of Z-pinch plasmas. For this reason it is useful to add deuterium as a 'tracer' in Z-pinch loads more often. For instance, it seems attractive to prepare wire-arrays from deuterated metal wires such as Pd.

Klir, D.; Kravarik, J.; Kubes, P.; Rezac, K. [Czech Technical University, Faculty of Electrical Engineering, Department of Physics, Technicka 2, 166 27 Prague 6 (Czech Republic); Ananeev, S. S.; Bakshaev, Yu. L.; Blinov, P. I.; Chernenko, A. S.; Kazakov, E. D.; Korolev, V. D.; Ustroev, G. I. [Russian Research Center Kurchatov Institute, 1 Kurchatov Sq., 123182 Moscow (Russian Federation)

2009-01-21

195

Fractal Model for Dielectric Relaxation in Deuteron Pseudospin Glass DRADP  

NASA Astrophysics Data System (ADS)

Proton and deuteron glasses such as Rb1-x(ND4)xD2PO4 (DRADP) are ideal systems for investigating dynamics of spin-glass-type systems because the basic mechanism for their dynamics is well understood. This mechanism consists of three processes; creation, effective diffusion, and annihilation of DPO4 and D3PO4 "Takagi groups." Each process involves a deuteron transfer from one side of an OSingle_Bond]D[centered_ellipsisO bond to the other. The effective diffusion changes the configurational energies of the D2PO4 "Slater groups" traversed by the Takagi groups. Each diffusion step changes this energy by a random amount with magnitude of order epsilond. This epsilond is comparable to the basic energy epsilon0 of the Slater model for RbD2PO4, and considerably smaller than the Takagi DPO4-D3PO4 pair creation energy 2epsilonc. The Takagi group diffusion path between creation and annihilation on average does not change the configurational energy. Thus the energy landscape along the path has an unbiased fractal nature, with small energy barriers superimposed on larger ones. The Takagi group diffusion path has side branches that are retraced, and loops of six or more steps. We approximate this path by a deterministic fractal path, having shorter side branches superimposed on longer ones, attached to a trunk running from the creation to the annihilation site. The longest dielectric relaxation time constant is governed by the Boltzmann factor for the highest barrier on the entire trunk. Shorter time constants correspond to the highest barriers on shorter trunk or branch segments. The relaxation strength distribution over these time constants depends on the basic fractal path unit, namely the number m of forward steps per side step. It depends also on temperature T and on epsilonc and epsilond. This model predicts with good qualitative accuracy the T and f (frequency) dependences of the real (epsilon') and imaginary (epsilon") parts of the dielectric permittivity measured by Courtens in x=0.62 DRADP over wide T and f ranges. No adjustable parameters were used except for m. The static and high-f permittivities epsilons, and epsiloninfinityf were chosen to fit Courtens' data, while epsilonc and epsilond were set at the values epsilonc/k=940 K and epsilond/k=140 K chosen by the Blinc/Kind groups to fit DRADP NMR data. This consideration of diffusion path topology and prediction of dielectric permittivity are major extensions of our previous work.

Schmidt, V. Hugo; Arbogast, Darin

2002-08-01

196

Deuteron as a toroidal Skyrmion: Electromagnetic form factors  

SciTech Connect

The minimal-energy solution in the baryon-number-two sector of the Skyrme model is a toroidally shaped soliton, and its ground state can be identified with the deuteron. A stringent test of this identification is provided by the electromagnetic form factors, since they probe the internal structure of the soliton. These form factors are calculated in the semiclassical approximation and are found to be in qualitative, although not quantitative, agreement with the form factors of the deuteron.

Braaten, E.; Carson, L.

1989-02-01

197

Deuteron Magnetic Resonance Study of Cupric Sulfate Pentahydrate  

Microsoft Academic Search

A deuteron magnetic resonance study is made of single crystals of CuSO4·5D2O between 130° and 360°K. The electric quadrupole coupling constant, the asymmetry parameter, and the directions of the principal axes of the field-gradient tensor are determined for each deuteron at 133.2° and 294.8°K. At low temperatures ten pairs of lines are observed, corresponding to five nonequivalent stationary water molecules.

Gen Soda; Takehiko Chiba

1969-01-01

198

Deuterons and space-momentum correlations in high energy nuclearcollisions  

SciTech Connect

Using a microscopic transport model together with a coalescence after-burner, we study the formation of deuterons in Au + Au central collisions at ?s=200 AGeV. It is found that the deuteron transverse momentum distributions are strongly affected by the nucleon space-momentum correlations, at the moment of freeze-out, which are mostly determined by the number of rescatterings. This feature is useful for studying collision dynamics at ultrarelativistic energies.

Monreal, B.; Bass, S.A.; Bleicher, M.; Esumi, S.; Greiner, W.; Li, Q.; Liu, H.; Llope, W.J.; Mattiello, R.; Panitkin, S.; Sakrejda, I.; Snellings, R.; Sorge, H.; Spieles, C.; Stocker, H.; Thomas, J.; Voloshin,S.; Wang, F.; Xu, N.

1999-06-26

199

Secondary Breakup of Aerated Liquid Jets in Subsonic Crossflow (Postprint).  

National Technical Information Service (NTIS)

An experimental investigation of the secondary breakup of an aerated liquid jet in subsonic crossflow is described. The present test conditions were similar to those encountered in fuel injection in ramjet engines. Previous studies of spray structures of ...

B. Miller C. Carter K. Lin K. A. Sallam M. Bingabr

2008-01-01

200

Fusion, Breakup and Scattering of Weakly Bound Nuclei  

SciTech Connect

We discuss the fusion, breakup and scattering of weakly bound nuclei, with emphasis on the experimental methods to measure fusion cross sections and results from experiments performed by our group in collaborative experiments.

Gomes, P. R. S.; Lubian, J.; Paes, B.; Monteiro, D. S.; Shorto, J. B.; Otomar, D. R.; Correa, T.; Lacerda, T.; Nunes, V. [Instituto de Fisica, Universidade Federal Fluminense Av. Litoranea s/n, Campus da Praia Vermelha, Niteroi, R.J., 24210-340 (Brazil)

2009-06-03

201

Analysis of the Low and List Drop-Breakup Formulation.  

NASA Astrophysics Data System (ADS)

An analysis of the Low and List drop-breakup formulation has uncovered several computational problems that arise in calculating both the fragment distribution function and the Bleck expansion coefficients that appear in the discrete coalcacence/breakup equation. Special procedures have been developed to deal effectively with these problems. The discrete coalescence/breakup equation has been solved using the Low and List breakup formulation and the earlier List and Gillespie formulation. Comparison shows that the Low and List model solutions approach equilibrium more slowly than do the earlier model solutions; moreover, the Low and List equilibrium drop spectra exhibit a bimodality in the small-drop end of the spectrum. The longer time constants associated with the Low and List equations ease somewhat the severe computational stability problem associated with List and Gillespie equations.

Brown, Philip S., Jr.

1986-03-01

202

The Lockerbie disaster and other aircraft breakups in midair.  

PubMed

This is a review of the experiences and activities of various specialty groups that constituted the organization developed to investigate the Lockerbie air disaster. Circumstances surrounding other aircraft midair breakup crashes are also discussed. PMID:2343852

Eckert, W G

1990-06-01

203

{sup 17}F breakup reactions: a touchstone for indirect measurements  

SciTech Connect

An exclusive study of {sup 17}F breakup reactions has been performed at the FRIBs facility of the Laboratori Nazionali del Sud in Catania (Italy). The experiment has been performed with the aim of testing the accuracy of the Coulomb-breakup indirect technique used to infer radiative-capture cross sections at low energies. This technique has been used in the {sup 7}Be(p,{gamma}){sup 8}B case, but has never been tested. By measuring the breakup of {sup 17}F into {sup 16}O+p, and comparing the inferred cross section for {sup 16}O(p,{gamma}){sup 17}F to direct precise measurements, the influence of E2 transitions and higher-order effects, that are predicted to be significant in Coulomb-breakup reactions, can be evaluated. The first results and preliminary model comparison are reported.

De Napoli, M. [INFN-Laboratori Nazionali del Sud, I-95123 Catania (Italy); Raciti, G.; Sfienti, C. [Dipartimento di Fisica e Astronomia, Universita di Catania, I-95123, Catania (Italy); INFN-Sezione di Catania, I-95123, Catania (Italy); Capel, P. [National Superconducting Cyclotron Laboratory, MSU, East Lansing, MI 48824-1321 (United States); Baye, D.; Descouvemont, P.; Sparenberg, J.-M. [Physique Quantique et Nucleaire (CP 229) ULB, B-1050 Brussels (Belgium); Giacoppo, F. [INFN-Laboratori Nazionali del Sud, I-95123 Catania (Italy); Dipartimento di Fisica, Universita di Messina, I-98166 Messina (Italy); Rapisarda, E. [INFN-Sezione di Catania, I-95123, Catania (Italy); Centro Siciliano di Fisica Nucleare e Struttura della Materia, I-95125 Catania (Italy); Cardella, G. [INFN-Sezione di Catania, I-95123, Catania (Italy); Mazzocchi, C. [INFN-Sezione di Milano and Universita di Milano, I-20133, Milano (Italy)

2011-10-28

204

Cumulative beam breakup in radio-frequency linacs.  

National Technical Information Service (NTIS)

An analytic model of cumulative beam breakup has been developed which is applicable to both low-velocity ion and high-energy electron linear accelerators. The model includes arbitrary velocity, acceleration, focusing, initial conditions, beam-cavity reson...

C. L. Bohn J. R. Delayen

1990-01-01

205

New description of the four-body breakup reaction  

SciTech Connect

We present a novel method of smoothing discrete breakup cross sections calculated by the method of continuum-discretized coupled channels. The smoothing method based on the complex scaling method is tested with success for a {sup 58}Ni(d,pn) reaction at 80 MeV as an example of three-body breakup reactions and applied to a {sup 12}C({sup 6}He,nn {sup 4}He) reaction at 229.8 MeV as an example of four-body breakup reactions. Fast convergence of the breakup cross section with respect to extending the model space is confirmed. The method is also applied to {sup 12}C({sup 6}He,nn {sup 4}He) and {sup 208}Pb({sup 6}He,nn {sup 4}He) reactions at 240 MeV/A and compared with the experimental data.

Matsumoto, Takuma [Meme Media Laboratory, Hokkaido University, Sapporo 060-8628 (Japan); Kato, Kiyoshi [Division of Physics, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Yahiro, Masanobu [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2010-11-15

206

17F breakup reactions: a touchstone for indirect measurements  

NASA Astrophysics Data System (ADS)

An exclusive study of 17F breakup reactions has been performed at the FRIBs facility of the Laboratori Nazionali del Sud in Catania (Italy). The experiment has been performed with the aim of testing the accuracy of the Coulomb-breakup indirect technique used to infer radiative-capture cross sections at low energies. This technique has been used in the 7Be(p,?)8B case, but has never been tested. By measuring the breakup of 17F into 16O+p, and comparing the inferred cross section for 16O(p,?)17F to direct precise measurements, the influence of E2 transitions and higher-order effects, that are predicted to be significant in Coulomb-breakup reactions, can be evaluated. The first results and preliminary model comparison are reported.

de Napoli, M.; Raciti, G.; Sfienti, C.; Capel, P.; Baye, D.; Giacoppo, F.; Rapisarda, E.; Cardella, G.; Descouvemont, P.; Mazzocchi, C.; Sparenberg, J.-M.

2011-10-01

207

17F Breakup Reactions:. a Touchstone for Indirect Measurements  

NASA Astrophysics Data System (ADS)

An exclusive study of 17F breakup reactions has been performed at the FRIBs facility of the Laboratori Nazionali del Sud in Catania (Italy). The experiment has been performed with the aim of testing the accuracy of the Coulomb-breakup indirect technique used to infer radiative-capture cross sections at low energies. This technique has been used in the 7Be(p, ?)8B case, but has never been tested. By measuring the breakup of 17F into 16O+p, and comparing the inferred cross section for 16O(p,?)17F to direct precise measurements, the influence of E2 transitions and higher-order effects, that are predicted to be significant in Coulomb-breakup reactions, can be evaluated. The first results and preliminary model comparison are reported.

Sfienti, C.; Raciti, G.; Capel, P.; Baye, D.; de Napoli, M.; Giacoppo, F.; Rapisarda, E.; Cardella, G.; Descouvemont, P.; Sparenberg, J.-M.; Mazzocchi, C.

208

Breakup and quench of molten metal fuel in sodium  

SciTech Connect

Tests have been conducted in which the breakup behavior of kilogram quantities of molten uranium, uranium-zirconium alloy, and uranium-iron alloy pour streams in 600C sodium was studied. A sodium depth of less than 0.3 m was required for hydrodynamic breakup and freezing of 25-mm pour streams of uranium and uranium-zirconium alloy with up to 400C melt superheat. The breakup material was primarily in the form of filaments and sheets with a settled bed voidage on the order of 0.9. The uranium-iron alloy with 800C melt superheat exhibited similar behavior except a sodium depth somewhat greater than 0.3 m was required for breakup and freezing of the particles.

Gabor, J.D.; Purviance, R.T.; Aeschlimann, R.W.; Spencer, B.W.

1988-01-01

209

Some features of spray breakup in effervescent atomizers  

Microsoft Academic Search

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally\\u000a using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified\\u000a into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray

Hrishikesh P. GadgilB; B. N. Raghunandan

2011-01-01

210

A review of Wilson Cycle plate margins: What is the role of mantle plumes in continental break-up along former sutures?  

NASA Astrophysics Data System (ADS)

It was Tuzo Wilson (1966) who recognised that the different faunal distributions on both sides of the present-day North Atlantic Ocean required the existence of an earlier proto-Atlantic Ocean. The observation that the present-day Atlantic Ocean mainly opened along a former suture was a crucial step in the formulation of the Wilson Cycle theory. The theory implies that collision zones are structures that are able to localize extensional deformation for long times after the collision has waned. We review margin pairs around the Atlantic and Indian Oceans with the aim to evaluate the extent to which oceanic opening used former sutures and to analyse the role of mantle plumes in continental break-up. We aid our analyses with plate tectonic reconstructions using GPlates (www.gplates.org). Already Wilson recognized that Atlantic break-up did not always follow the precise line of previous junction. For example, Atlantic opening did not utilize the Iapetus suture in Great Britain and rather than opening along the younger Rheic suture north of Florida, break-up occurred along the older Pan-African structures south of Florida. As others before us, we find no correlation of suture and break-up age. Often continental break-up occurs some hundreds of Myrs after collision, but it may also take more than a Gyr, as for example for Australia-Antarctica and Congo-São Francisco. This places serious constraints on potential collision zone weakening mechanisms. Several studies have pointed to a link between continental break-up and large-scale mantle upwellings. It is, however, much debated whether plumes use existing rifts as a pathway, or whether plumes play an active role in causing rifting. It is also important to realise that in several cases break-up cannot be related to plume activity. Examples are the Iberia-Newfoundland, Equatorial Atlantic Ocean, and Australia-Antarctica plate margins. For margins that are associated with large igneous provinces (LIPs), we find a positive correlation between break-up age and LIP age. We interpret this to indicate that plumes can aid the factual continental break-up. However, plumes may have been guided towards the rift for margins that experienced a long rift history (e.g., Norway-Greenland), to then trigger the break-up. This could offer a partial reconciliation in the debate of a passive or active role for mantle plumes in continental break-up. (Wilson, J.T., 1966. Did the Atlantic close and then re-open? Nature 211, 676-681)

Buiter, Susanne; Torsvik, Trond

2013-04-01

211

Breakup of a Liquid Drop Falling Through a Quiescent Media: A DNS Study  

NASA Astrophysics Data System (ADS)

The breakup of falling liquid droplets in a stationary media is studied using Direct Numerical Simulations (DNS). An adaptive Volume of Fluid (VOF) method based on an octree Cartesian grid generation is employed, considerably reducing the computational cost. Fragmentations are followed reaching approximately stable clouds of droplets up to 1/1000 of the initial droplet diameter. Three different simulations are performed investigating the influence of the initial E"otv"os number. The mechanism of breakup, one of the most unclear phenomena in multiphase systems is described in detail. The wave growth over the bag, creation and retraction of punctures and ligament formation are presented and results are compared with recent theoretical investigations of (Savva & Bush, J. Fluid. Mech. 626: 211-240.) and (Bermond & Villermaux, J. Fluid. Mech. 524: 121-130.). The roles of Rayleigh-Taylor and Rayleigh-Plateau instabilities on breakup are also described and their influences on further cluster-of-fragments creation are shown. The outcomes can be used to develop current secondary atomization models. Moreover, the results can be used for better understanding of rain drop atomization during precipitation, as well as water droplet atomization in cooling towers.

Jalaal, Maziyar; Mehravaran, Kian

2011-11-01

212

The breakup of (16)O and its astrophysical implications  

NASA Astrophysics Data System (ADS)

The feasibility of using the breakup of 16O to obtain information about the 12C(/alpha,/gamma)16O radiative capture reaction has been studied in a series of experiments performed at the Nuclear Structure Research Laboratory at the University of Rochester. The 16O breakup fragments-12C and 4He-were identified using a new focal-plane detector capable of identifying these fragments down to a relative energy of 50 keV. The relative energy spectra obtained from 16O breakup on a 58Ni target are dominated by sequential breakup from 9.85 MeV, and 10.36 MeV excited states in 16O. There is also some evidence of breakup at relative energies below 1 MeV. Interpretation of this low energy yield in terms of E2 Coulomb excitation leads to a value of SE2=346 keV b at Erel=0.828 MeV after making a correction for the contribution due to nuclear breakup. This suggests that the rate of the 12C(/alpha,/gamma)16O reaction at astrophysical energies is much higher than is presently accepted, which would have an enormous impact on stellar nucleosynthesis.

Bryan, Diane Carol

1998-07-01

213

Breakup of an electrified viscous thread with charged surfactants  

NASA Astrophysics Data System (ADS)

The dynamics and breakup of electrified viscous jets in the presence of ionic surfactants at the interface are investigated theoretically. Axisymmetric configurations are considered and the jet is surrounded by a concentrically placed cylindrical electrode, which is held at a constant voltage potential. The annular region between the jet and the electrode is taken to be a hydrodynamically passive dielectric medium and an electric field is set up there and drives the flow, along with other physical mechanisms including capillary instability and viscous effects. The jet fluid is taken to be a symmetric electrolyte and proper modeling of the cationic and anionic species is used by considering the Nernst-Planck equations in order to find the volume charge density that influences the electric field in the jet. A positively charged insoluble surfactant is present at the interface, and its evolution, as well as the resulting value of the local surface tension coefficient, is coupled with the voltage potential at the interface. The resulting coupled nonlinear systems are derived and analytical progress is made by carrying out a nonlinear slender jet approximation. The reduced model is described by a number of hydrodynamic, electrical, and electrokinetic parameters, and an extensive computational study is undertaken to elucidate the dynamics along with allied linear properties. It is established that the jet ruptures in finite time provided the outer electrode is sufficiently far away, and numerous examples are given where the dimensionless parameters can be used to control the size of the satellite drops that form beyond the topological transition, as well as the time to break up. It is also shown that pinching solutions follow the self-similar dynamics of clean viscous jets at times close to the breakup time. Finally, a further asymptotic theory is developed for large Debye layers to produce an additional model that incorporates the effects of surface charge diffusion. Numerical solutions establish that the presence of electrostatic and electrokinetic effects increases the sizes of satellites but have a rather weak influence on the time to rupture.

Conroy, D. T.; Matar, O. K.; Craster, R. V.; Papageorgiou, D. T.

2011-02-01

214

Fluctuations in Rayleigh breakup induced by particulates.  

PubMed

A jet of liquid is intrinsically unstable to radial perturbations and will spontaneously break to form a series of droplets. This well known instability, the Rayleigh-Plateau instability, is controlled and used commercially in continuous inkjet printing. In this application it is important that fluctuations in drop velocity are minimised. However, the addition of particulates to the liquid is observed to strongly increase these fluctuations. The particulates are usually in the form of pigment particles of size O(100 nm) and at a concentration where they may hydrodynamically interact, particularly in the strong shear field within the nozzle (O(10(7) s(-1))). The boundary layer thickness within the nozzle is O(1 ?m) and therefore the particulate size is a significant fraction. We therefore expect that the particles are capable of perturbing the boundary layer and hence the jet. Measurement of jet breakup fluctuation leads to a description of particulates interacting within and with the shear field associated with the boundary layer at the nozzle wall. PMID:19846049

Clarke, A; Rieubland, S

2009-10-06

215

Tiny Traces of a Big Asteroid Breakup  

NASA Astrophysics Data System (ADS)

Ancient geologic conditions in southern Sweden were ideal to preserve meteorites that fell to Earth about half a billion years ago. Researcher Birger Schmitz (working as a visiting professor at Rice University and now at the University of Lund, Sweden) and his colleagues in Goteborg, Sweden have analyzed over 40 of these rare fossil meteorites along with relict chromite grains collected from sites in a 250,000-square-kilometer area of 480-million-year-old limestone. They attribute the abundance and wide distribution of this space debris to a meteorite influx at least one hundred times more intense than the influx today. Rather than a smorgasbord of different types, cosmochemical evidence shows that the fossil meteorites are L or LL chondrites leading the team to conclude that these meteorites and chromite grains derived from a major collision in the asteroid belt. The age of the limestone is very close to the impact age of many L chondrites suggesting that this major collision was the breakup of the L chondrite parent body, possibly the largest impact in the asteroid belt in the last few billion years.

Martel, L. M. V.

2004-03-01

216

Photoproduction of the {phi} meson off the deuteron near threshold  

SciTech Connect

We discuss coherent and incoherent {phi} meson photoproduction off the deuteron at low energy and small momentum transfer with the aim of checking whether the recent experimental data need for their interpretation an inclusion of exotic channels. Our analysis of the differential cross section and spin-density matrix elements shows that new data on the {gamma}D{yields}{phi}X reaction at E{sub {gamma}}{approx}2 GeV may be understood on the basis of conventional dynamics. However, a certain ambiguity of the deviation between the model predictions and the data from the laser electron photon beamline at SPring-8 (LEPS) on the {gamma}p{yields}{phi}p reaction still remains. To make a firm conclusion about a possible manifestation of exotic channels, one has to improve the resolution of the data by providing additional information on the channels with spin- and double-spin-flip transitions which are sensitive to the properties of the photoproduction amplitude in the {gamma}p and {gamma}D reactions. This information may be used as an additional independent test of the {phi} meson photoproduction mechanism.

Titov, A. I. [Forschungzentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, RU-141980 (Russian Federation); Kaempfer, B. [Forschungzentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Institut fuer Theoretische Physik, TU Dresden, D-01062 Dresden (Germany)

2007-09-15

217

Vibration-Induced Gas-Liquid Interface Breakup  

NASA Astrophysics Data System (ADS)

Gas-liquid interfaces can be forced to break up when subjected to vibrations within critical ranges of frequency and amplitude. This breakup mechanism was examined experimentally using deep layers of silicone oils over a range of viscosity and sinusoidal, primarily axial vibration conditions that can produce dramatic disturbances at the gas-liquid free surface. Although small-amplitude vibrations produce standing Faraday waves, large-amplitude vibrations produce liquid jets into the gas, droplets pinching off from the jets, gas cavities in the liquid from droplet impact, and bubble transport below the interface. Experiments used several different silicone oils over a range of pressures and vibration conditions. Computational simulations exhibiting similar behavior will be included in the presentation. Applications include liquid fuel rockets, inertial sensing devices, moving vehicles, mixing processes, and acoustic excitation. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

O'Hern, Timothy; Torczynski, John; Romero, Ed; Shelden, Bion

2010-11-01

218

Morphological classification of low viscosity drop bag breakup in a continuous air jet stream  

NASA Astrophysics Data System (ADS)

To investigate the effect of Rayleigh-Taylor wave number in the region of maximum cross stream dimension (NRT) on drop breakup morphology, the breakup properties of accelerating low viscosity liquid drops (water and ethanol drops, diameter=1.2-6.6 mm, Weber number=10-80) were investigated using high-speed digital photography. The results of morphological analysis show a good correlation of the observed breakup type with NRT; bag breakup occurred when NRT was 1/3-1, bag-stamen breakup at 1-2, and dual-bag breakup at 2-3. The number of nodes in bag breakup, bag-stamen breakup, and dual-bag breakup all increased with Weber number. The experimental results are consistent with the model estimates and in good agreement with those reported in the literature.

Zhao, Hui; Liu, Hai-Feng; Li, Wei-Feng; Xu, Jian-Liang

2010-11-01

219

Middle-high latitude N2O distributions related to the arctic vortex breakup  

NASA Astrophysics Data System (ADS)

The relationship of N2O distributions with the Arctic vortex breakup is first analyzed with a probability distribution function (PDF) analysis. The N2O concentration shows different distributions between the early and late vortex breakup years. In the early breakup years, the N2O concentration shows low values and large dispersions after the vortex breakup, which is related to the inhomogeneity in the vertical advection in the middle and high latitude lower stratosphere. The horizontal diffusion coefficient (K,,) shows a larger value accordingly. In the late breakup years, the N2O concentration shows high values and more uniform distributions than in the early years after the vortex breakup, with a smaller vertical advection and K,, after the vortex breakup. It is found that the N2O distributions are largely affected by the Arctic vortex breakup time but the dynamically defined vortex breakup time is not the only factor.

Zhou, L. B.; Zou, H.; Gao, Y. Q.

2006-03-01

220

Three-nucleon force effects in the analyzing powers of the d(pol.) p breakup at 130-MeV  

SciTech Connect

A measurement of the analyzing powers for the 1H(\\vec {d},pp)n breakup reaction at 130 MeV polarized deuteron beam energy was carried out at KVI Groningen. The experimental setup covered a large fraction of the phase space. Obtained tensor analyzing powers T22 for selected kinematical configurations have been compared to theoretical predictions based on various approaches: the rigorous Faddeev calculations using the realistic nucleon--nucleon potentials with and without three nucleon force (3NF) models, predictions of the chiral perturbation theory, and coupled channel calculations with the explicit \\Delta degrees of freedom. In the presented configurations the results of all predictions are very close to one another and there are no significant 3NF influences. Not all of the data can be satisfactory reproduced by the theoretical calculations.

Avagyan, Harutyun; Stephan, E.; Kistryn, St.; Bodek, K.; Ciepal, I.; Deltuva, A.; Epelbaum, Evgeny; Gloeckle, Walter; Golak, J.; Kalantar-Nayestanaki, Nasser; Kamada, H.; Kis, M.; Klos, B.; Kozela, A.; Kuros-Zolnierczuk, J.; Mahjour-Shafiei, M.; Meissner, Ulf-G.; Micherdzinska, Anna; Nogga, Andreas; Sauer, Peter; Skibinski, R.; Sworst, R.; Witala, Henryk; Zejma, J.; Zipper, W.

2008-01-01

221

Deuteron injector for Peking University Neutron Imaging Facility project  

NASA Astrophysics Data System (ADS)

The deuteron injector developed for the PKUNIFTY (Peking University Neutron Imaging Facility) has been installed and commissioned at Peking University (PKU). The injector system must transfer 50 keV 50 mA of D+ ion beam to the entrance of the 2 MeV radio frequency quadrupole (RFQ) with 10% duty factor (1 ms, 100 Hz). A compact 2.45 GHz permanent magnet electron cyclotron resonance (PMECR) ion source and a 1.36 m long low energy beam transport (LEBT) line using two solenoids was developed as the deuteron injector. A ?5 mm four-quadrant diaphragm was used to simulate the entrance of RFQ electrodes. The beam parameters are measured after this core with an emittance measurement unit (EMU) and a bending magnet for ion fraction analysis at the end of injector. During the commissioning, 77 mA of total deuteron beam was extracted from PMECR and 56 mA of pure D+ beam that passed through the ?5 mm four-quadrant diaphragm was obtained at the position of RFQ entrance with the measured normalized rms emittance 0.12-0.16? mm mrad. Ion species analysis results show that the deuteron fraction is as high as 99.5%. All of the parameters satisfy PKUNIFTY's requirements. In this paper, we will describe the deuteron injector design and report the commissioning results as well as the initial operation.

Ren, H. T.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Yuan, Z. X.; Zhao, J.; Zhang, M.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y.; Chen, J. E.

2012-02-01

222

Deuteron induced secondary electron emission from titanium deuteride surface  

NASA Astrophysics Data System (ADS)

The secondary electron yield from titanium deuteride surface induced by deuterons was measured in the 80-254 keV energy range using a quotient method. The clean surface was produced by removing the oxide layers and absorbed gases on the titanium deuteride target by self-sputtering with deuterons. The maximum value of the secondary electron yield is about 1.37 at 143 keV. The secondary electron yield of deuterons in titanium deuteride was compared with the yield of deuterons in Ti, measured in the current study, and with the yield of protons in Ti, measured by Hasselkamp et al. in 1990: values were found to be similar when comparing ions with the same velocity. This suggests the weak influence of the deuteriding process on secondary electron emission. The relation between secondary electron yield and electronic stopping power of deuterons in titanium deuteride was also discussed, with an expansion of the theory of Sternglass. From the results the partition factor B is a little larger than 0.5, which may be related to the derivation from the equipartition rule near the stopping power maximum or to the cascade process which is neglected in the theory of Sternglass.

Jianlin, Ke; Meng, Liu; Changgeng, Zhou

2012-06-01

223

Deuteron injector for Peking University Neutron Imaging Facility project  

SciTech Connect

The deuteron injector developed for the PKUNIFTY (Peking University Neutron Imaging Facility) has been installed and commissioned at Peking University (PKU). The injector system must transfer 50 keV 50 mA of D{sup +} ion beam to the entrance of the 2 MeV radio frequency quadrupole (RFQ) with 10% duty factor (1 ms, 100 Hz). A compact 2.45 GHz permanent magnet electron cyclotron resonance (PMECR) ion source and a 1.36 m long low energy beam transport (LEBT) line using two solenoids was developed as the deuteron injector. A {phi}5 mm four-quadrant diaphragm was used to simulate the entrance of RFQ electrodes. The beam parameters are measured after this core with an emittance measurement unit (EMU) and a bending magnet for ion fraction analysis at the end of injector. During the commissioning, 77 mA of total deuteron beam was extracted from PMECR and 56 mA of pure D{sup +} beam that passed through the {phi}5 mm four-quadrant diaphragm was obtained at the position of RFQ entrance with the measured normalized rms emittance 0.12-0.16{pi} mm mrad. Ion species analysis results show that the deuteron fraction is as high as 99.5%. All of the parameters satisfy PKUNIFTY's requirements. In this paper, we will describe the deuteron injector design and report the commissioning results as well as the initial operation.

Ren, H. T.; Chen, J. E. [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Yuan, Z. X.; Zhao, J.; Zhang, M.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y. [SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

2012-02-15

224

Strength And Flow Effects In The Atmospheric Breakup Of Meteoroids  

NASA Astrophysics Data System (ADS)

When meteoroids enter a planetary atmosphere, the breakup process is governed by the Rayleigh-Taylor instability, mitigated by the strength of the meteoritic material. Particle sizes in the breakup cascade depend on the perturbation length scales exhibiting growth, and on the spatial variation of strength in the body. The physics of meteoroid entry is thus related closely to high-pressure strength experiments using lasers, where strength is inferred by studying the Rayleigh-Taylor growth of perturbations. There are significant discrepancies between predicted and observed breakup altitudes of meteoroids, which in turn reduce the accuracy of assessments of the impact threat from asteroids. We have found that samples of Fe-Ni meteorite material exhibit significantly higher static and dynamic strength than previously reported, largely eliminating the discrepancy. Simulations of stress and flow within and around a meteor describe the onset and evolution of the breakup process in reasonable detail, including the transport of small particles into the lower atmosphere. These results can be used to calibrate compact expressions describing the breakup conditions.

Swift, Damian; Chen, L.; Kraus, R.; Mulford, R.; El-Dasher, B.; Milathianaki, D.; Remington, B.; Eakins, D.

2012-10-01

225

Semi-inclusive deep inelastic electron scattering off the deuteron and the neutron to proton structure function ratio  

Microsoft Academic Search

The production of slow nucleons in semi-inclusive deep inelastic electron scattering off the deuteron is investigated in the region x ? 0.3. It is shown that within the spectator mechanism the semi-inclusive cross section exhibits a scaling property even at moderate values of Q2 (? few (GeV\\/c)2) accessible at present facilities, like CEBAF. Such a scaling property can be used

Silvano Simula

1996-01-01

226

Deuteron magnetic quadrupole moment from chiral effective field theory  

NASA Astrophysics Data System (ADS)

We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading order in the systematic expansion provided by chiral effective field theory. We take into account parity (P) and time-reversal (T) violation which, at the quark-gluon level, results from the QCD vacuum angle and dimension-six operators that originate from physics beyond the Standard Model. We show that the deuteron MQM can be expressed in terms of five low-energy constants that appear in the P- and T-violating nuclear potential and electromagnetic current, four of which also contribute to the electric dipole moments of light nuclei. We conclude that the deuteron MQM has an enhanced sensitivity to the QCD vacuum angle and that its measurement would be complementary to the proposed measurements of light-nuclear EDMs.

Liu, C.-P.; de Vries, J.; Mereghetti, E.; Timmermans, R. G. E.; van Kolck, U.

2012-07-01

227

Scaling laws for near-barrier Coulomb and nuclear breakup  

NASA Astrophysics Data System (ADS)

We investigate the nuclear and the Coulomb contributions to the breakup cross sections of 6Li in collisions with targets in different mass ranges. Comparing cross sections for different targets at collision energies corresponding to the same E/VB, we obtain interesting scaling laws. First, we derive an approximate linear expression for the nuclear breakup cross section as a function of AT1/3. We then confirm the validity of this expression performing continuum-discretized coupled-channels (CDCC) calculations. Scaling laws for the Coulomb breakup cross section are also investigated. In this case, our CDCC calculations indicate that this cross section has a linear dependence on the atomic number of the target. This behavior is explained by qualitative arguments. Our findings, which are consistent with previously obtained results for higher energies, are important when planning for experiments involving exotic weakly bound nuclei.

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

2013-10-01

228

Influence of the projectile description on breakup calculations  

SciTech Connect

Calculations of the breakup of {sup 8}B and {sup 11}Be are performed with the aim of analyzing their sensitivity to the projectile description. Several potentials adjusted on the same experimental data are used for each projectile. The results vary significantly with the potential choice, and this sensitivity differs from one projectile to the other. In the {sup 8}B case, the breakup cross section is approximately scaled by the asymptotic normalization coefficient (ANC) of the initial bound state. For {sup 11}Be, the overall normalization of the breakup cross section is no longer solely determined by the ANC. The partial waves describing the continuum are found to play a significant role in this variation, as the sensitivity of the phase shifts to the projectile description changes with the physical constraints imposed to the potential.

Capel, P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T2A3 (Canada); Nunes, F.M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

2006-01-15

229

Dynamics of thin-film breakup in a constricted pore  

SciTech Connect

To understand foam formation in porous media, this work considers the dynamics of a wetting liquid film forming an unstable collar (or collars) in a constricted cylindrical tube. A hydrodynamic lubrication analysis is presented to describe the time evolution of a thin viscous film under the influence of surface tension and conjoining or disjoining forces. Time to breakup depends on the pore shape, the strength of the conjoining or disjoining force, the initial film profile, and also, the fluid viscosity, interfacial tension, and unconstricted pore radius which combine to form a characteristic scaling time. Agreement is found between breakup times predicted from the hydrodynamic analysis, and from 16 mm movies taken of the breakup phenomena over a wide range of initial film thicknesses. 11 references, 5 figures.

Gauglitz, P.A.; Radke, C.J.

1985-01-01

230

Effect of boiling regime on melt stream breakup in water  

SciTech Connect

A study has been performed examining the breakup and mixing behavior of an initially coherent stream of high-density melt as it flows downward through water. This work has application to the quenching of molten core materials as they drain downward during a postulated severe reactor accident. The study has included examination of various models of breakup distances based upon interfacial instabilities dominated either by liquid-liquid contact or by liquid-vapor contact. A series of experiments was performed to provide a data base for assessment of the various modeling approaches. The experiments involved Wood's metal (T/sub m/ = 73/sup 0/C, rho = 9.2 g/cm/sup 3/, d/sub j/ = 20 mm) poured into a deep pool of water. The temperature of the water and wood's metal were varied to span the range from single-phase, liquid-liquid contact to the film boiling regime. Experiment results showed that breakup occurred largely as a result of the spreading and entrainment from the leading edge of the jet. However, for streams of sufficient lengths a breakup length could be discerned at which there was no longer a coherent central core of the jet to feed the leading edge region. The erosion of the vertical trailing column is by Kelvin-Helmoltz instabilities and related disengagement of droplets from the jet into the surrounding fluid. For conditions of liquid-liquid contact, the breakup length has been found to be about 20 jet diameters; when substantial vapor is produced at the interface due to heat transfer from the jet to the water, the breakup distance was found to range to as high as 50 jet diameters. The former values are close to the analytical prediction of Taylor, whereas the latter values are better predicted by the model of Epstein and Fauske.

Spencer, B.W.; Gabor, J.D.; Cassulo, J.C.

1986-01-01

231

A Spin-Frozen Polarized Target of Proton and Deuteron  

NASA Astrophysics Data System (ADS)

A spin-frozen polarized target of proton and deuteron was constructed for the measurement of spin dependent parameters of hadron-hadron scatterings at the 12 GeV KEK proton synchrotron. The target was also used for experiments at LAMPF-HRS. As the proton and deuteron targets, 1,2-propanediol and fully deuterated propanediol (D-8) with stable Crv complex (EHBA) were used, respectively. The characteristics and performance of the targets are described. Data on the nuclear spin lattice relaxation time (Tln) with proton beam give us information on the Kapitza resistance between the target material and liquid 3He/4He mixture.

Ishimoto, Shigeru; Hiramatsu, Shigenori; Isagawa, Shigeru; Masaike, Akira; Morimoto, Kimio

1989-10-01

232

The deuteron structure function F2 with CLAS  

SciTech Connect

The inclusive, inelastic eD scattering cross section has been measured with the CLAS detector in Hall B of the Thomas Jefferson National Accelerator Facility (TJNAF). Combining these data and previously measured world data we have extracted Nachtmann moments of the deuteron structure function F2 in the region 0.4 < Q2 < 100 GeV2/c2. These results are published in hep-ex/0506004. The purpose of the present CLAS-Note is to tabulate the CLAS deuteron F2 data. A description of the data analysis is reported in hep-ex/0506004.

M. Osipenko; G. Ricco; S. Simula; M. Battaglieri; M. Ripani

2005-07-01

233

Fast ignition by a laser-accelerated deuteron beam  

NASA Astrophysics Data System (ADS)

Fast ignition (FI) of a conically guided DT assembly by a laser-accelerated deuteron beam is proposed. The uniformly pre-compressed fuel of 300 g cm-3 is heated by the deuteron beam of a Maxwellian energy distribution with a temperature of 3 MeV. This scheme makes full use of the deposited energy of the alpha particles produced by the athermal nuclear reactions and can save about 4.5% ion-beam energy compared with the FI by fast proton or carbon ion beams. The ignition energy delivered by the external beam can be reduced appreciably.

Liu, Dong-Xiao; Hong, Wei; Shan, Lian-Qiang; Wu, Shun-Chao; Gu, Yu-Qiu

2011-03-01

234

Elastic electron-deuteron scattering beyond one-photon exchange  

SciTech Connect

We discuss elastic electron-deuteron (ed) scattering beyond the Born approximation. The reaction amplitude contains six generalized form factors, but only three linearly independent combinations of them (generalized charge, quadrupole, and magnetic form factors) contribute to the reaction cross section in second-order perturbation theory. We examine the two-photon exchange and find that it includes two types of diagrams, where two virtual photons are interacting with the same nucleon and where the photons are interacting with different nucleons. It is shown that the two-photon-exchange amplitude is strongly connected with the deuteron wave function at short distances.

Kobushkin, A. P.; Krivenko-Emetov, Ya. D.; Dubnicka, S. [Bogolyubov Institute for Theoretical Physics, Metrologicheskaya Street 14B, 03680 Kiev (Ukraine); Institute for Nuclear Research, Prospekt Nauki 47, 03680 Kiev (Ukraine); Institute of Physics, Slovak Academy of Sciences, Bratislava (Slovakia)

2010-05-15

235

P and T Violating Form Factors of the Deuteron  

SciTech Connect

We calculate the electric-dipole and magnetic-quadrupole form factors of the deuteron that arise as a low-energy manifestation of parity and time-reversal violation in quark-gluon interactions. We consider the QCD vacuum angle and the dimension-six operators that originate from physics beyond the standard model: the quark electric and chromoelectric dipole moments and the gluon chromoelectric dipole moment. Within the framework of two-flavor chiral perturbation theory, we show that in combination with the nucleon electric dipole moment, the deuteron moments would allow an identification of the dominant source(s) of symmetry violation.

Vries, J. de; Timmermans, R. G. E. [KVI, Theory Group, University of Groningen, 9747 AA Groningen (Netherlands); Mereghetti, E.; Kolck, U. van [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2011-08-26

236

P and T Violating Form Factors of the Deuteron  

NASA Astrophysics Data System (ADS)

We calculate the electric-dipole and magnetic-quadrupole form factors of the deuteron that arise as a low-energy manifestation of parity and time-reversal violation in quark-gluon interactions. We consider the QCD vacuum angle and the dimension-six operators that originate from physics beyond the standard model: the quark electric and chromoelectric dipole moments and the gluon chromoelectric dipole moment. Within the framework of two-flavor chiral perturbation theory, we show that in combination with the nucleon electric dipole moment, the deuteron moments would allow an identification of the dominant source(s) of symmetry violation.

de Vries, J.; Mereghetti, E.; Timmermans, R. G. E.; van Kolck, U.

2011-08-01

237

Breakup of 11Li in a three-cluster model  

NASA Astrophysics Data System (ADS)

The 11Li breakup on a 208Pb target is studied in the Coulomb corrected eikonal approximation by using a 9Li+n+n three-body description of the projectile. The 11Li wave functions are defined in the hyperspherical formalism for bound and scattering states, and are obtained from effective 9Li+n and n+n interactions. The 9Li+n+n three-body phase shifts suggest the existence of a narrow 1- resonance near 0.5 MeV above threshold. This resonance shows up as a peak in the breakup cross section, and is supported by experimental data.

Pinilla, E.; Descouvemont, P.; Baye, D.

2013-04-01

238

Transfer and breakup of light weakly-bound nuclei  

SciTech Connect

We investigate the origin of the effects observed in the fusion cross section of light weakly bound nuclei, through a review of the most recent experimental and theoretical works. In particular we focus on the well-documented fusion suppression at energies just above the potential barrier. We show that, besides the couplings to the breakup process, effects due to the couplings to transfer need be taken into account. The magnitude of the cross section for the direct process, breakup or transfer, is not a reliable indicator of the size of the effects induced on the elastic scattering and fusion.

Raabe, R. [GANIL, Bd Henri Becquerel, BP 55027, 14076 CAEN Cedex 05 (France)

2009-03-04

239

Solving the three-body Coulomb breakup problem using exterior complex scaling  

SciTech Connect

Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a ''reduction to computation'' of all aspects of the physics is given by the application of exterior complex scaling, a modern variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations, and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wave function can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium.

McCurdy, C.W.; Baertschy, M.; Rescigno, T.N.

2004-05-17

240

Coulomb and nuclear-induced break-up of halo nuclei at bombarding energies around the Coulomb barrier  

Microsoft Academic Search

We investigate the relative importance of the Coulomb and nuclear fields to induce the break-up of neutron-rich nuclei such as 11Li at energies close to the Coulomb barrier. We assume that the mechanism that leads to the separation is the excitation of a low-lying dipole mode in which the weakly-bound neutron halo performs a collective oscillation against the residual nuclear

C. H. Dasso; J. L. Guisado; S. M. Lenzi; A. Vitturi

1996-01-01

241

Measurements of the Cross Sections and A y for D( p, n) Inclusive Breakup Reaction at 170 MeV  

NASA Astrophysics Data System (ADS)

The effects of three-nucleon force (3NF) has been actively studied by using the nucleon-deuteron ( Nd) scattering states. The differential cross sections of the elastic Nd scattering at the energy below 150 MeV can be well reproduced by incorporating 3NF in the Faddeev calculation based on modern nucleon-nucleon (NN) interactions. On the other hand, the differential cross sections of Nd elastic and inelastic scatterings at 250 MeV show large discrepancies between the data and the Faddeev calculations with 3NF. It indicates the presence of the missing features of the three nucleon system at this energy region. For the systematic study about the energy dependence of this large discrepancies, we measured the differential cross sections and the vector analyzing power A y for the 2H( p, n) inclusive breakup reaction at 170 MeV. The experiment was carried out at RCNP by detecting scattered neutrons by using the neutron detector NPOL3. The data was compared with the results of the Faddeev calculations with and without the 3NF.

Maeda, Y.; Saito, T.; Miyasako, H.; Uesaka, T.; Ota, S.; Kawase, S.; Kikuchi, T.; Tokieda, H.; Kawabata, T.; Yako, K.; Wakasa, T.; Sakaguchi, S.; Chen, R.; Sakaguchi, H.; Shima, T.; Suzuki, T.; Tamii, A.

2013-03-01

242

Neutrino Deuteron Scattering and the Virtual Nucleon Density Matrix.  

National Technical Information Service (NTIS)

The formalism of the virtual nucleon density matrix has been suggested for the relativistic description of the inelastic scattering on the deuteron a + d implies b + N sub 1 + N sub 2 . The efficiency of the suggested formalism is demonstrated for the cas...

M. P. Rekalo G. I. Gakh A. P. Rekalo

1979-01-01

243

Pion-deuteron scattering and the. delta. N interaction  

SciTech Connect

We evaluate the contribution of a J/sup P/ = 2/sup +/ dibaryon resonance to the forward ..pi..d amplitude, taking into account the fact that the deuteron is a loosely bound structure. Comparison with the data shows that these are well compatible with a resonance in the /sup 5/S/sub 2/, I = 1 ..delta..-N channel.

Dosch, H.G.; de Andrade, S.C.B.; Ferreira, E.; Munguia, G.P.

1984-04-01

244

SPINatCOSY: Spin-Manipulating Polarized Deuterons and Protons  

NASA Astrophysics Data System (ADS)

We studied spin manipulation of 1.85 GeV/c polarized deuteron beam stored in COSY obtaining a spin-flip efficiency of 97+/-1%. We first discovered experimentally and then explained theoretically interesting behavior of the deuteron tensor polarization. We, for the first time, studied systematically spin resonance strengths induced by rf dipoles and solenoids. We found huge disagreements between the strengths measured in controlled Froissart-Stora sweeps and the theoretical values calculated using the well-known formulae. These data instigated re-examination of these formulae. We tested Chao's proposed new matrix formalism for describing the spin dynamics due to a single spin resonance, which may be the first fundamental improvement of the Froissart-Stora equation in that it allows analytic calculation of the beam polarization's behavior inside a resonance. Our measurements of the deuteron's polarization near and inside the resonance agreed precisely with the Chao formalism's predicted oscillations. We tested Kondratenko's proposal to overcome depolarizing resonances by ramping through them with a crossing pattern, which should force the depolarizing contributions to cancel themselves. Our first test of this idea with 2.1 GeV/c protons was not conclusive but a later test with 1.85 GeV/c deuterons demonstrated a rather substantial reduction in the depolarization compared to the tune jump at the same rate.

Leonova, M. A.; Chao, A. W.; Krisch, A. D.; Morozov, V. S.; Raymond, R. S.; Sivers, D. W.; Wong, V. K.; Garishvili, A.; Gebel, R.; Lehrach, A.; Lorentz, B.; Maier, R.; Prasuhn, D.; Stockhorst, H.; Welsch, D.; Hinterberger, F.; Ulbrich, K.; Derbenev, Ya. S.; Kondratenko, A. M.; Stephenson, E. J.

2009-08-01

245

JLAB Measurements of the Deuteron Electric and Magnetic Form Factors  

SciTech Connect

Large-momentum transfer JLab measurements of the deuteron electric and magnetic form factors are reported. The data are compared to theoretical models based on the relativistic impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark-dimensional scaling and perturbative QCD.

Gerassimos G. Petratos

2000-12-12

246

Photodissociation of the Deuteron from 150 to 450 Mev  

Microsoft Academic Search

The photodissociation of the deuteron has been investigated for laboratory photon energies of 150, 200, 250, 300, 350, 400, and 450 Mev at laboratory angles of 39, 56, 74, 93, 115, and 138 degrees. The process was identified by detecting the recoil protons in a range-ionization telescope. The total cross section has a relative minimum at 150 Mev followed by

J. C. Keck; A. V. Tollestrup

1956-01-01

247

Remaining problems in the low-energy pd breakup reaction  

SciTech Connect

Space star anomalies in nd and pd breakup reactions are peculiar phenomena, different from other discrepancies in the 3N systems. Recently progress on the pd star anomaly has been made both in experiment and in theoretical calculations. We have started systematic experiments on the pd star, and some preliminary data are presented.

Sagara, K.; Sueta, T.; Sugimoto, T.; Shimoda, H.; Kuroita, S.; Maeda, Y. [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan)

2008-04-29

248

Three-body breakup within the fully discretized Faddeev equations  

NASA Astrophysics Data System (ADS)

A novel approach is developed to find the three-body breakup amplitudes and cross sections within the modified Faddeev equation framework. The method is based on the latticelike discretization of the three-body continuum with a three-body stationary wave-packet basis in momentum space. The approach makes it possible to simplify drastically all the three- and few-body breakup calculations due to discrete representation for the few-body continuum and lattice representation for all the scattering operators entering the integral equation kernels. As a result, the few-body breakup can be treated as a particular case of multichannel scattering in which part of the channels represents the true few-body continuum states. As an illustration for the novel approach, an accurate calculations for the three-body breakup process n+d?n+n+p with nonlocal and local NN interactions are calculated. The results obtained reproduce nicely the benchmark calculation results using the traditional Faddeev scheme which requires much more tedious and time-consuming calculations.

Rubtsova, O. A.; Pomerantsev, V. N.; Kukulin, V. I.; Faessler, Amand

2012-09-01

249

Drop Breakup in the Flow Through Fixed Beds  

Microsoft Academic Search

The flow through a dilute, disordered fixed bed of fibers has been shown to produce large polymer conformation change beyond a certain critical flow rate^1. We now examine the effect of this flow on the shape and breakup of viscous drops. The stochastic, Lagrangian time-varying flow through fixed beds is of particular interest since it may efficiently induce drop fragmentation

Alisa B. Mosler; Eric S. G. Shaqfeh

1996-01-01

250

ISS Update: ATV-3 ReEntry Breakup Recorder  

NASA Video Gallery

ISS Update Commentator Pat Ryan talks with Dr. William Ailor, Principal Investigator for the ReEntry Breakup Recorder (REBR) for The Aerospace Corporation. Ailor talks about capturing data as Europe’s ATV-3 cargo craft re-enters the Earth’s atmosphere for a fiery destruction over the Pacific Ocean.

Mark Garcia

2012-09-24

251

The Soviet Breakup and U.S. Foreign Policy.  

ERIC Educational Resources Information Center

|This issue of a quarterly publication on world affairs explores the historical significance of the disintegration of the Soviet Union and the implication for U.S. foreign policy. With the breakup of the USSR in 1990-91, Russia for the first time this century does not have control over the non-Russian nations of its former empire in Central Asia,…

Lynch, Allen

1991-01-01

252

When Good Friends Say Goodbye: A Parasocial Breakup Study  

Microsoft Academic Search

This study examines viewers'reactions to parasocial breakup with medi- ated characters in light of interpersonal and mass communication theo- ries. Following the airing of the last episode of the television show Friends, 279 students completed surveys assessing their viewing habits, their attitudes toward the show and their favorite character, and their loneliness. The intensity of the parasocial relationship with the

Keren Eyal; Jonathan Cohen

2006-01-01

253

The Breakup of Temperature Inversions In Steep Valleys  

Microsoft Academic Search

The purpose of this research is to model and provide a better understanding of tem- perature inversions breakup in steep valleys. The Advanced Regional Prediction Sys- tem (ARPS), a three-dimensional, compressible, and non-hydrostatic modeling tool developed by the Center for Analysis and Prediction of Storms at the University of Oklahoma was used. Many field studies indicate that the evolution of

A. Colette

2002-01-01

254

Breakup of New Orleans Households after Hurricane Katrina  

ERIC Educational Resources Information Center

|Theory and evidence on disaster-induced population displacement have focused on individual and population-subgroup characteristics. Less is known about impacts on households. I estimate excess incidence of household breakup resulting from Hurricane Katrina by comparing a probability sample of pre-Katrina New Orleans resident adult household heads…

Rendall, Michael S.

2011-01-01

255

On the rotational breakup of cometary nuclei and centaurs  

Microsoft Academic Search

Here we estimate the regions of stability, fragmentation, and destruction for cometary bodies versus rotational breakup in the radius–rotational period plane. By testing different plausible physical models of the cometary nucleus equation of state, we show that the plane is divided into 3 segments: the allowed, damaged, and forbidden regions. We then compare the location of well-observed comets with respect

I. Toth; C. M. Lisse

2006-01-01

256

Investigation of Precipitating Electrons During an Auroral Breakup.  

National Technical Information Service (NTIS)

During a breakup aurora a sounding rocket detected two different types of particle spectra. The optical aurora was monitored by low light level TV. The first type of spectra consisted of two populations, a low energy population of secondary electrons and ...

I. Sandahl L. Eliasson B. Holback

1986-01-01

257

Effects of bubble coalescence and breakup on conduit dynamics  

Microsoft Academic Search

Volatiles play a central role in eruption behavior. The ability of an exsolved gas phase to move through, and escape from, ascending magma controls whether an eruption is explosive or effusive. In this study, we investigate the dynamics and interactions of gas bubbles as they rise in a conduit. We focus on the coalescence and breakup dynamics of buoyant bubbles

C. Huber; J. Dufek; A. Parmigiani; M. Manga

2008-01-01

258

SIMULATION OF BUBBLE BREAKUP DYNAMICS IN HOMOGENEOUS TURBULENCE  

Microsoft Academic Search

This article presents numerical simulation results for the deformation and breakup of bubbles in homogeneous turbulence under zero gravity conditions. The lattice Boltzmann method was used in the simulations. Homogeneous turbulence was generated by a random stirring force that acted on the fluid in a three-dimensional periodic box. The grid size was sufficiently small that the smallest scales of motion

D. Qian; J. B. McLaughlin; K. Sankaranarayanan; S. Sundaresan; K. Kontomaris

2006-01-01

259

An Ellipsoidal Model for Secondary Breakup of Spray Droplets  

Microsoft Academic Search

In sprays of liquid drops dynamic interaction with the gas can cause drops to breakup into daughter drops. To analyse this situation it is assumed that the drop has the shape of a deformable ellipsoid of revolution. When placed in a stream the high stagnation pressure at the symmetry axis, coupled with Bernoulli suction around the equator tends to squeeze

T. S. Lundgren

1998-01-01

260

Modes of Aero-Breakup with Visco-Elastic Liquids  

NASA Astrophysics Data System (ADS)

We use Laser-Induced Fluorescence (LIF) at 15 nanosecond exposures to resolve the fine structure of interfacial instabilities and their evolutions (complete, to final particle-cloud formation) in supersonic aero-breakup of visco-elastic liquid drops. With fixed elasticity (3.8% aPTBP), the key parameter is the Weber (We) number, and the behavior can be summarized as follows: (a) initial loss of stability is at We~6.103 breakup, gradual and sporadic, occurs from the ends of long filamentous structures stretched out of the drop equatorial region in a tentacle-like fashion; (b) a second transition is at We~4.104 within a similar overall pattern the breakup process is greatly intensified; detachments occur in a rather coherent, rupture-like fashion, thus limiting the growth of the ``root'' filaments which become much thinner and more numerous. This mode of breakup remains effective, but further intensifies, as the We increases to ~1.6.105, reached in the present work. With our distributed visualization system we are able to capture in a statistically comprehensive manner the resulting clouds (i.e. conserving mass), and we demonstrate this capability by showing a sample particle-size distribution at near the second transition (We = 3.7.104).

Ng, Chee-Loon; Theofanous, Theo G.

2008-07-01

261

Breakup of an electrified viscous thread with charged surfactants  

Microsoft Academic Search

The dynamics and breakup of electrified viscous jets in the presence of ionic surfactants at the interface are investigated theoretically. Axisymmetric configurations are considered and the jet is surrounded by a concentrically placed cylindrical electrode, which is held at a constant voltage potential. The annular region between the jet and the electrode is taken to be a hydrodynamically passive dielectric

D. T. Conroy; O. K. Matar; R. V. Craster; D. T. Papageorgiou

2011-01-01

262

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction  

NASA Astrophysics Data System (ADS)

We discus recent developments in theory of high energy two-body break-up of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon between two outgoing nucleons. This final state hard rescattering can be expressed through the hard NN scattering amplitude. Within HRM we discuss hard break-up reactions involving D and 3He targets and demonstrate how these reactions are sensitive to the dynamics of hard pn and pp interaction. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Sargsian, Misak

2008-10-01

263

Separation of Cowling channel and local closure currents in the vicinity of a substorm breakup spiral  

NASA Astrophysics Data System (ADS)

The substorm breakup spiral demarcates the westernmost terminator of the substorm current wedge. A long-standing debate has been devoted to the question of to what extent the strong upward field-aligned currents (FAC) in that spiral are either closed by downward FAC through Pedersen currents flowing radially to the center of the spiral ("local closure") or by currents that flow westward though a Cowling channel which extends in the region eastward of the spiral ("Cowling closure"). In particular, studies using ground-based and space-based instrumentation came to systematically different results. In order to address this question, we reanalyze a pseudobreakup spiral event on 3 February 1999, ˜2204 UT, that has been observed with the MIRACLE network of ground-based instruments in Fennoscandia and for which spatial results of electric fields, conductances, and currents have been calculated by Amm et al. (2001). We apply a new technique that allows, under certain geometrical assumptions, the current systems to separate in the vicinity of the breakup spiral into their local closure and Cowling closure parts. The result shows that for the event analyzed, ˜68% of the upward FAC in the spiral is closed via the local closure current system and the remaining ˜32% via the Cowling closure current system. Therefore, the local closure mechanism is the dominating provider of the upward FAC in the breakup spiral overall. However, a localized area at the western flank of the spiral, where conductance gradients are largest, exists in which the Cowling closure dominates and feeds more than 80% of the upward FAC in that area. Further studies are required in order to examine the generality of the results obtained for our specific event.

Amm, O.; Fujii, R.

2008-06-01

264

Breakup characteristics of a liquid jet in subsonic crossflow  

NASA Astrophysics Data System (ADS)

This thesis describes an experimental investigation of the breakup processes involved in the formation of a spray created by a liquid jet injected into a gaseous crossflow. This work is motivated by the utilization of this method to inject fuel in combustors and afterburners of airplane engines. This study aims to develop a better understanding of the spray breakup processes and to provide better experimental inputs to improve the fidelity of numerical models. A review of the literature in this field identified the fundamental physical processes involved in the breakup of the spray and the dependence of spray properties on operating conditions. The time taken for the liquid column to break up into ligaments and droplets, the primary breakup time and the effect of injector geometry on the spray formation processes and spray properties as the key research areas in which research done so far has been inadequate. Determination of the location where the liquid column broke up was made difficult by the presence of a large number of droplets surrounding it. This study utilizes the liquid jet light guiding technique that enables accurate measurements of this location for a wide range of operating conditions. Prior to this study, the primary breakup time was thought to be a function the density ratio of the liquid and the gas, the diameter of the orifice and the air velocity. This study found that the time to breakup of the liquid column depends on the Reynolds number of the liquid jet. This suggests that the breakup of a turbulent liquid jet is influenced by both the aerodynamic breakup processes and the turbulent breakup processes. Observations of the phenomenon of the liquid jet splitting up into two or more jets were made at some operating conditions with the aid of the new visualization technique. Finally, this thesis investigates the effect of injector geometry on spray characteristics. One injector was a round edged orifice with a length to diameter ratio of 1 and a discharge coefficient of 0.95 at the operating conditions of interest. The other injector was a sharp edged orifice with a length to diameter ratio of 10 and a discharge coefficient of 0.74 at the operating conditions of interest. It was shown that the sharp edged orifice was likely to develop cavitation bubbles beyond a flow Reynolds number of 8,000. It was found that a sharp transition in the injector can lead to the liquid column disintegrating sooner. The classical Rayleigh Taylor instabilities that are usually seen with a smooth transition in the injector were not seen in the presence of a sharp transition. The droplets produced with such an injector are larger in size and the spray penetrated deeper into the crossflow.

Gopala, Yogish

265

Deuteron scattering on {sup 6}Li at an energy of 25 MeV  

SciTech Connect

At an energy of 25 MeV and in the angular range 7{sup o}-175{sup o} in the laboratory frame, angular distributions were measured for elastic deuteron scattering on {sup 6}Li nuclei and for the respective inelastic-scattering processes accompanied by the transitions to the ground state (1+) of the {sup 6}Li nucleus and to its excited state at E{sub x} = 2.186 MeV (J{sup {pi}} = 3{sup +}). The resulting data were analyzed on the basis of the optical model of the nucleus and the coupled-reaction-channel method with allowance for the mechanism of alpha-particle-cluster exchange. It is shown that only upon including, in the analysis, channel coupling and the exchange mechanism can the experimental cross sections for elastic and inelastic scattering be reproduced over the entire range of angles.

Burtebayev, N. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Artemov, S. V. [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan); Duisebayev, B. A.; Kerimkulov, Zh. K. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Kuranov, S. B. [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan); Sakuta, S. B., E-mail: sakuta@dni.polyn.kiae.s [Russian Research Center Kurchatov Institute (Russian Federation)

2010-05-15

266

A 'snowball Earth' climate triggered by continental break-up through changes in runoff.  

PubMed

Geological and palaeomagnetic studies indicate that ice sheets may have reached the Equator at the end of the Proterozoic eon, 800 to 550 million years ago, leading to the suggestion of a fully ice-covered 'snowball Earth'. Climate model simulations indicate that such a snowball state for the Earth depends on anomalously low atmospheric carbon dioxide concentrations, in addition to the Sun being 6 per cent fainter than it is today. However, the mechanisms producing such low carbon dioxide concentrations remain controversial. Here we assess the effect of the palaeogeographic changes preceding the Sturtian glacial period, 750 million years ago, on the long-term evolution of atmospheric carbon dioxide levels using the coupled climate-geochemical model GEOCLIM. In our simulation, the continental break-up of Rodinia leads to an increase in runoff and hence consumption of carbon dioxide through continental weathering that decreases atmospheric carbon dioxide concentrations by 1,320 p.p.m. This indicates that tectonic changes could have triggered a progressive transition from a 'greenhouse' to an 'icehouse' climate during the Neoproterozoic era. When we combine these results with the concomitant weathering effect of the voluminous basaltic traps erupted throughout the break-up of Rodinia, our simulation results in a snowball glaciation. PMID:15029192

Donnadieu, Yannick; Goddéris, Yves; Ramstein, Gilles; Nédélec, Anne; Meert, Joseph

2004-03-18

267

Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression.  

PubMed

Rifting of the continents leading to plate rupture occurs by a combination of mechanical deformation and magma intrusion, yet the spatial and temporal scales over which these alternate mechanisms localize extensional strain remain controversial. Here we quantify anisotropy of the upper crust across the volcanically active Afar Triple Junction using shear-wave splitting from local earthquakes to evaluate the distribution and orientation of strain in a region of continental breakup. The pattern of S-wave splitting in Afar is best explained by anisotropy from deformation-related structures, with the dramatic change in splitting parameters into the rift axis from the increased density of dyke-induced faulting combined with a contribution from oriented melt pockets near volcanic centres. The lack of rift-perpendicular anisotropy in the lithosphere, and corroborating geoscientific evidence of extension dominated by dyking, provide strong evidence that magma intrusion achieves the majority of plate opening in this zone of incipient plate rupture. PMID:21505441

Keir, Derek; Belachew, M; Ebinger, C J; Kendall, J-M; Hammond, J O S; Stuart, G W; Ayele, A; Rowland, J V

2011-01-01

268

Mapping the evolving strain field during continental breakup from crustal anisotropy in the Afar Depression  

NASA Astrophysics Data System (ADS)

Rifting of the continents leading to plate rupture occurs by a combination of mechanical deformation and magma intrusion, yet the spatial and temporal scales over which these alternate mechanisms localize extensional strain remains controversial. Here we quantify anisotropy of the upper crust across the volcanically active Afar Triple Junction using shear-wave splitting from local earthquakes to evaluate the distribution and orientation of strain in a region of continental breakup. The pattern of S-wave splitting in Afar is best explained by anisotropy from deformation-related structures, with the dramatic change in splitting parameters into the rift axis from the increased density of dyke-induced faulting combined with a contribution from oriented melt pockets near volcanic centres. The lack of rift-perpendicular anisotropy in the lithosphere, and corroborating geoscientific evidence of extension dominated by dyking, provide strong evidence that magma intrusion achieves the majority of plate opening in this zone of incipient plate rupture.

Keir, D.; Belachew, M.; Ebinger, C.; Kendall, M.; Hammond, J.; Stuart, G.; Ayele, A.; Rowland, J.

2012-04-01

269

{sup 9}Be breakup polarization potential at near barrier energies  

SciTech Connect

In this work, we study the {sup 9}Be+{sup 144}Sm system with the aim of extracting the breakup polarization potential and to check the influence of this channel on other reaction channels at energies close to the Coulomb barrier. As the projectile breaks up into four fragments the Continuum Discretized Coupled Channel (CDCC) method becomes a tool very difficult to be used. For this reason, we developed a methodology that consists in calculating the dynamic polarization potential (DPP) for the breakup channel using a very simple approximate technique. This technique has already been recently used in obtaining the dynamic polarization potential for the {sup 7}Li+{sup 27}Al system.

Garcia, V. N.; Lubian, J.; Gomes, P. R. S. [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, Gragoata, Niteroi, 24210-340, Rio de Janeiro (Brazil); Canto, L. F. [Intituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68528, 21941-972, Rio de Janeiro (Brazil); Gomez-Camacho, A. [Departamento del Acelerador, Instituto Nacional de Investigaciones Nucleares-Mexico D. F. Centro-Mexico (Mexico)

2009-06-03

270

Systematic study of {sup 8}B breakup cross sections  

SciTech Connect

Breakup cross sections of {sup 8}B are analyzed in a two-body structure model, with an inert {sup 7}Be core and a loosely bound valence proton. The nuclear induced breakup is calculated in an eikonal approximation, and Coulomb dissociation is calculated to first order. There is a strong correlation within this model between the total E1 strength and the one-proton removal cross section {sigma}{sub 1p}. Thus we find that the measured values of {sigma}{sub 1p} for a carbon target are consistent with the E1 strength extracted in recent Coulomb dissociation experiments. The predicted {sigma}{sub 1p} values on high-Z targets are significantly larger than measured. We discuss how this discrepancy can be reduced by improving the description of Coulomb dissociation. (c) 2000 The American Physical Society.

Esbensen, Henning [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hencken, Kai [Institut fuer Physik, Universitaet Basel, 4056 Basel, (Switzerland)

2000-05-01

271

High deuteron polarization in trityl radical doped deuterated polystyrene  

NASA Astrophysics Data System (ADS)

Deuterated polystyrene for polarized solid targets has been prepared by chemical doping with the trityl radical 'Finland D36' (AH 110 355 deutero acid form). Thin foils doped with various radical densities have been produced using tetrahydrofuran as solvent. Dynamic nuclear polarization technique has been applied to polarize deuterons in the samples (98%-D) at the temperature range of about 1 K and magnetic fields of 2.5 T and 5.0 T. A maximum deuteron polarization of ?61.5% with a build-up time of 100 min has been achieved at 5.0 T and about 500 mK at a radical density of 1.16×1019 spins/g.

Wang, Li; Berlin, A.; Doshita, N.; Herick, J.; Hess, C.; Iwata, T.; Kondo, K.; Meyer, W.; Reicherz, G.

2013-11-01

272

Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST  

NASA Astrophysics Data System (ADS)

We report a precision measurement of the deuteron tensor analyzing powers T20 and T21 at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50fm-1 with the Bates Large Acceptance Spectrometer Toroid using a highly polarized deuterium internal gas target. The data are in excellent agreement with calculations in a framework of effective field theory. The deuteron charge monopole and quadrupole form factors GC and GQ were separated with improved precision, and the location of the first node of GC was confirmed at Q=4.19±0.05fm-1. The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T20 and the first node of GC.

Zhang, C.; Kohl, M.; Akdogan, T.; Alarcon, R.; Bertozzi, W.; Booth, E.; Botto, T.; Calarco, J. R.; Clasie, B.; Crawford, C.; Degrush, A.; Dow, K.; Farkhondeh, M.; Fatemi, R.; Filoti, O.; Franklin, W.; Gao, H.; Geis, E.; Gilad, S.; Hasell, D.; Karpius, P.; Kolster, H.; Lee, T.; Maschinot, A.; Matthews, J.; McIlhany, K.; Meitanis, N.; Milner, R.; Rapaport, J.; Redwine, R.; Seely, J.; Shinozaki, A.; Sindile, A.; Širca, S.; Six, E.; Smith, T.; Tonguc, B.; Tschalär, C.; Tsentalovich, E.; Turchinetz, W.; Xiao, Y.; Xu, W.; Zhou, Z.-L.; Ziskin, V.; Zwart, T.

2011-12-01

273

Spin Manipulating Vector and Tensor Polarized Deuterons Stored in COSY  

NASA Astrophysics Data System (ADS)

We recently studied spin flipping and spin manipulation of a simultaneously vector and tensor polarized deuteron beam stored in the COSY Cooler Synchrotron at 1.85 GeV/c. Using the EDDA detector we calibrated vector and tensor analyzing powers, which were earlier unknown at this energy; thus, we were able to obtain the absolute values for both the vector and tensor polarizations. We manipulated the deuteron's polarization using a new water-cooled ferrite rf dipole, by adiabatically sweeping its frequency through an rf-induced spin resonance. We first experimentally determined the resonance's frequency and then varied the dipole's frequency range and frequency ramp time. This allowed us to maximize the vector polarization spin-flip efficiency to about 97 ± 1%. We also studied the interesting tensor polarization manipulation in considerable detail.

Morozov, Vassili; Krisch, Alan; Leonova, Maria; Raymond, Richard; Sivers, Dennis; Wong, Victor; Yonehara, Katsuya; Bechstedt, Ulf; Gebel, Ralf; Lehrach, Andreas; Lorentz, Bernd; Maier, Rudolf; Schnase, Alexander; Stockhorst, Hans; Eversheim, Dieter; Hinterberger, Frank; Rohdjess, Heiko; Ulbrich, Kay

2004-05-01

274

?-Delayed Deuteron Emission from Li11: Decay of the Halo  

NASA Astrophysics Data System (ADS)

The deuteron-emission channel in the ? decay of the halo nucleus Li11 was measured at the Isotope Separator and Accelerator facility at TRIUMF by implanting postaccelerated Li11 ions into a segmented silicon detector. The events of interest were identified by correlating the decays of Li11 with those of the daughter nuclei. This method allowed the energy spectrum of the emitted deuterons to be extracted, free from contributions from other channels, and a precise value for the branching ratio Bd=1.30(13)×10-4 to be deduced for Ec.m.>200keV. The results provide the first unambiguous experimental evidence that the decay takes place essentially in the halo of Li11 and that it proceeds mainly to the Li9+d continuum, opening up a new means to study the halo wave function of Li11.

Raabe, R.; Andreyev, A.; Borge, M. J. G.; Buchmann, L.; Capel, P.; Fynbo, H. O. U.; Huyse, M.; Kanungo, R.; Kirchner, T.; Mattoon, C.; Morton, A. C.; Mukha, I.; Pearson, J.; Ponsaers, J.; Ressler, J. J.; Riisager, K.; Ruiz, C.; Ruprecht, G.; Sarazin, F.; Tengblad, O.; van Duppen, P.; Walden, P.

2008-11-01

275

Neutron structure effects in the deuteron and one neutron halos  

NASA Astrophysics Data System (ADS)

Although the neutron (n) does not carry a total electric charge, its charge and magnetization distributions represented in momentum space by the electromagnetic form factors, F1(n)(q2) and F2(n)(q2), lead to an electromagnetic potential of the neutron. Using this fact, we calculate the electromagnetic corrections to the binding energy, Bd, of the deuteron and a one-neutron halo nucleus (Be11) by evaluating the neutron-proton and the neutron-charged core (Be10) potential, respectively. The correction to Bd (˜9 keV) is comparable to that arising due to the inclusion of the ?-isobar component in the deuteron wave function. In the case of the more loosely bound halo nucleus, Be11, the correction is close to about 2 keV.

Nowakowski, M.; Kelkar, N. G.; Mart, T.

2006-08-01

276

Deuteron production and elliptic flow in relativistic heavy ion collisions  

SciTech Connect

The hadronic transport model ART is extended to include the production and annihilation of deuterons via the reactions BB{r_reversible}dM, where B and M stand for baryons and mesons, respectively, as well as their elastic scattering with mesons and baryons in the hadronic matter. This new hadronic transport model is used to study the transverse momentum spectrum and elliptic flow of deuterons in relativistic heavy ion collisions, with the initial hadron distributions after hadronization of the produced quark-gluon plasma taken from a blast wave model. The results are compared with those measured by the PHENIX and STAR Collaborations for Au+Au collisions at {radical}(s{sub NN})=200 GeV and also with those obtained from the coalescence model based on freeze-out nucleons in the transport model.

Oh, Yongseok [Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843 (United States); Korea Institute of Science and Technology Information, Daejeon 305-806 (Korea, Republic of); Lin Ziwei [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Ko, Che Ming [Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843 (United States)

2009-12-15

277

Deuteron Beam Driven Fast Ignition of a Pre-Compressed Inertial Confinement Fusion (ICF) Target  

NASA Astrophysics Data System (ADS)

Fast Ignition (FI) is recognized as the most promising approach to achieving the high energy gain target performance needed for commercial inertial confinement fusion (ICF). Deuteron beams not only provide heating via linear energy transfer when slowing down, but can also provide extra ?bonus? fusion energy through reactions in the target. In view of the recent observation of ultra-high-density deuterium clusters, in addition to the extra energy gain expected from the deuterons, we estimate the impact of the added deposition energy from the deuteron beam to the target fuel based on calculations using a modified energy multiplication factor Fc. The deuteron beam energy deposition range and time are also calculated in order to estimate optimized deuteron initial energy. The aim of this study is to explore the potential advantages of a deuteron beam driven FI scheme for ICF. However, a much more comprehensive calculation is needed to realize a full 3D experimental design for maximum fusion gain.

Yang, Xiaoling; Miley, George; Flippo, Kirk; Hora, Heinrich

2010-11-01

278

Core excitation contributions to the breakup of the one-neutron halo nucleus {sup 11}Be on a proton  

SciTech Connect

The effect of the core excitation in the breakup of a one-neutron halo nucleus is studied within two different reaction formalisms, namely, the core excited model and the single-scattering approximation of the three-body Faddeev-Alt-Grassberger-Sandhas equations with target-core potential allowing for the core excitation. As an example, we consider the breakup of {sup 11}Be on a proton target at 63.7 MeV/nucleon incident energy and calculate the semi-inclusive cross section in the excitation energy interval E{sub x}=3.0-5.5 MeV (E{sub rel}=2.5-5 MeV) containing the 3/2{sup +} resonance with dominant contribution of the {sup 10}Be(2{sup +}) core excited state. The effect of the core excitation to the breakup cross section integrated around this resonance is found to be very significant. Moreover, when resonant and nonresonant contributions are added, the resulting semi-inclusive cross section is in reasonable agreement with the existing data, demonstrating the relevance of the core excitation mechanism for this observable. The present calculations also show the importance of incorporating the energy dependence of the core-target transition operators in the reaction formalism.

Crespo, R. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, PT-1649-003 Lisboa (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Taguspark, Av. Prof. Cavaco Silva, Taguspark, PT-2780-990 Porto Salvo, Oeiras (Portugal); Deltuva, A. [Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, PT-1649-003 Lisboa (Portugal); Moro, A. M. [Departamento de Fisica Atomica, Molecular e Nuclear, Universidad Seville, Universidad de Sevilla, Apartado 1065, ES-41080 Sevilla (Spain)

2011-04-15

279

Laser-induced break-up of water jet waveguide  

Microsoft Academic Search

In this article, an optical method to control the break-up of high-speed liquid jets is proposed. The method consists of focusing the light of a pulsed laser source into the jet behaving as a waveguide. Experiments were performed with the help of a Q-switched frequency doubled Nd:Yag laser ( ?=532 nm). The jet diameter was 48 µm and jet velocities from 100

P. Couty; Á. Spiegel; N. Vágó; B. I. Ugurtas; P. Hoffmann

2004-01-01

280

Breakup and early seafloor spreading between India and Antarctica  

Microsoft Academic Search

We present a tectonic interpretation of the breakup and early seafloor spreading between India and Antarctica based on improved coverage of potential field and seismic data off the east Antarctic margin between the Gunnerus Ridge and the Bruce Rise. We have identified a series of ENE trending Mesozoic magnetic anomalies from chron M9o (~130.2 Ma) to M2o (~124.1 Ma) in

Carmen Gaina; R. Dietmar Müller; Belinda Brown; Takemi Ishihara; Sergey Ivanov

2007-01-01

281

JET BREAKUP AND SPRAY FORMATION IN A DIESEL ENGINE.  

SciTech Connect

The breakup of injected fuel into spray is of key interest to the design of a fuel efficient, nonpolluting diesel engine. We report preliminary progress on the numerical simulation of diesel fuel injection spray with the front tracking code FronTier. Our simulation design is set to match experiments at ANL, and our present agreement is semi-quantitative. Future efforts will include mesh refinement studies, which will better model the turbulent flow.

GLIMM,J.; LI,X.; KIM,M.N.; OH,W.; MARCHESE,A.; SAMULYAK,R.; TZANOS,C.

2003-06-17

282

Breakup of simple and compound drops and bubbles  

Microsoft Academic Search

Micro- and nano-scale free surface flows with interface rupture, e.g. drop or bubble breakup, are not only of fundamental scientific importance but also lie at the heart of diverse engineering applications such as ink jet printing, DNA and protein micro-\\/nano-arraying, and fabrication of particles and capsules for controlled release of medicines. The primary goal of this thesis is to advance

Ronald Suryo

2006-01-01

283

Fusion and breakup at the barrier with unstable nuclei  

Microsoft Academic Search

Present experiments related to fusion and breakup processes in the energy region immediately above the Coulomb barrier are reviewed and discussed. The most of the material utilised concerns very recent experimental work not yet published, still subject to possible slight changes. These data involve skin, skin-like and halo nuclei with weakly bound outer nucleons.Skin nuclei: 1) the results on 4,6He

C. Signorini

1997-01-01

284

Breakup Reactions and Exotic Structures of Halo Nuclei  

Microsoft Academic Search

We have performed breakup experiments of halo nuclei: 11Li with a Pb target, 14Be with 12C and proton targets, and 19C on a proton target at approximately 70 MeV\\/nucleon at RIKEN. These experiments aim at investigating the E1 response of 11Li, and at searching for the low-lying discrete resonances of 14Be and 19C above the neutron decay threshold. The former

Takashi Nakamura; Yoshiteru Satou; Takashi Sugimoto; Yosuke Kondo

2009-01-01

285

Radial electron-beam-breakup transit-time oscillator  

SciTech Connect

A new radially-driven electron-beam-breakup transit-time oscillator has been investigated analytically and through computer simulation as a compact low-impedance high-power microwave generator. In a 1MV, 50kA device 35cm in radius and 15cm long, with no external magnetic field, 5GW of extracted power and a growth rate of 0.26/ns have been observed. Theoretical maximum efficiencies are several times higher.

Mostrom, M.A. [Mission Research Corp., Albuquerque, NM (United States); Kwan, T.J.T. [Los Alamos National Lab., NM (United States)

1995-01-01

286

Spin structure functions: Proton / deuteron measurements in the resonance region  

SciTech Connect

The RSS experiment ran in Hall C at Jefferson Lab and measured the proton and deuteron beam-target asymmetries for parallel and perpendicular target fields over a W range from pion threshold to 1.9 GeV at Q{sup 2} {approx} 1.3 GeV{sup 2}. Preliminary results for the proton spin structure functions g{sub 1} and g{sub 2} are presented.

Mark Jones; RSS Collaboration

2006-02-01

287

The Photodisintegration of the Deuteron at Intermediate Energies. I  

Microsoft Academic Search

Measurements have been made of the absolute cross section for photodisintegration of the deuteron at six gamma-ray energies in a range where the photomagnetic effect is small compared with the photoelectric. The methods of determining the gamma-ray flux are described as are the high pressure deuterium-filled ionization chamber and proportional counter used to determine the disintegration rate. The results are

C. A. Barnes; J. H. Carver; G. H. Stafford; D. H. Wilkinson

1952-01-01

288

FROM NEUTRON FLUX REACTOR TO DEUTERON FLUX REACTOR  

SciTech Connect

Comparison between nuclear fission and nuclear fusion shows their similarity and disparity in development. It addresses the importance of the understanding in physics. The wave nature of the deuterons inside the crystal lattice means that the boundary conditions are essential to understand the physics of condensed matter nuclear science. Five steps are discussed to show the progress of the understanding in the development of the selective resonant tunneling. The suggestions for the future development are proposed as well.

Li, Xing Z. [Department of Physics, Tsinghua University, Beijing 100084 (China)

2009-07-26

289

Deuteron irradiation creep of chemically vapor deposited silicon carbide fibers  

Microsoft Academic Search

Irradiation creep tests were conducted on Textron SCS-6 silicon carbide (SiC) fibers during irradiation with 14 MeV deuterons at 450 and 600°C. The fibers are produced by a CVD procedure; their microstructure may therefore be representative for the matrix of a SiC composite. There is a significant radiation induced increase in creep deformation. Both quantities, irradiation creep strain and creep

R. Scholz

1998-01-01

290

Deuteron Spin Structure Functions in the Resonance and DIS Regions  

SciTech Connect

We derive relations between spin-dependent nuclear and nucleon g_1 and g_2 structure functions, valid at all Q^2, and in both the resonance and deep inelastic regions. We apply the formalism to the specific case of the deuteron, which is often used as a source of neutron structure information, and compare the size of the nuclear corrections calculated using exact kinematics and using approximations applicable at large Q^2.

S. Kulagin; W. Melnitchouk

2007-10-03

291

Light Front Field Theory Calculation of Deuteron Properties  

NASA Astrophysics Data System (ADS)

Light front dynamics is a promising approach for calculating the deuteron wave function and form factors at high momentum transfers. However, in light-front dynamics rotational invariance is not manifest, which results in a splitting in the binding energies of states with different magnetic quantum numbers and a breaking of the angular condition for the matrix elements of the deuteron current operator. The objective of this work is to investigate the symptoms of broken rotational invariance. We first consider the Wick-Cutkosky model. The binding energies of states with different m values are split when calculated with the OME potential, but this splitting is reduced for all states when the TME potential is included. Next, we derive light-front nucleon-nucleon OME and TME potentials from an effective nuclear Lagrangian. We consider first the potentials generated by the exchange of pions only, then the potentials generated by all the mesons. For both models, there is a splitting in the binding energies between the m=0 and m=1 deuteron states when the OME potential is used, which is reduced when we include the TME potential. The deuteron wave functions are used to calculate the electromagnetic and axial current matrix elements and form factors. The matrix elements of the electromagnetic current operator have better transformation properties under rotations when we use the OME potential instead of the OME+TME potential to calculate the wave functions. At momentum transfers greater than about 2 GeV^2, the breaking of rotational invariance causes less uncertainty in the A and B form factors than do the uncertainties in the nucleon form factors.

Cooke, Jason R.

2001-12-01

292

Measurement of inclusive spin structure functions of the deuteron  

Microsoft Academic Search

We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer [Q2=0.27 1.3 (GeV\\/c)2] and final hadronic state mass in the nucleon resonance region (W=1.08 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (15ND3) and

J. Yun; S. E. Kuhn; G. E. Dodge; T. A. Forest; M. Taiuti; G. S. Adams; M. J. Amaryan; E. Anciant; M. Anghinolfi; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; S. Barrow; M. Battaglieri; K. Beard; M. Bektasoglu; W. Bertozzi; N. Bianchi; A. S. Biselli; S. Boiarinov; P. Bosted; S. Bouchigny; R. Bradford; D. Branford; W. K. Brooks; S. Bueltmann; V. D. Burkert; C. Butuceanu; J. R. Calarco; D. S. Carman; B. Carnahan; C. Cetina; L. Ciciani; P. L. Cole; A. Coleman; J. Connelly; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. Cummings; E. De Sanctis; R. De Vita; P. V. Degtyarenko; R. A. Demirchyan; H. Denizli; L. C. Dennis; K. V. Dharmawardane; C. Djalali; J. Domingo; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; M. Eckhause; Y. V. Efremenko; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; A. Empl; L. Farhi; R. Fatemi; R. J. Feuerbach; J. Ficenec; K. Fissum; A. Freyberger; V. Frolov; H. Funsten; S. J. Gaff; M. Gai; G. Gavalian; V. B. Gavrilov; S. Gilad; G. P. Gilfoyle; K. L. Giovanetti; P. Girard; E. Golovatch; C. I. Gordon; K. A. Griffioen; M. Guidal; M. Guillo; L. Guo; V. Gyurjyan; C. Hadjidakis; D. Hancock; J. Hardie; D. Heddle; P. Heimberg; F. W. Hersman; K. Hicks; R. S. Hicks; M. Holtrop; J. Hu; C. E. Hyde-Wright; M. M. Ito; D. Jenkins; K. Joo; C. Keith; J. H. Kelley; M. Khandaker; K. Y. Kim; W. Kim; A. Klein; F. J. Klein; A. V. Klimenko; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; J. Kuhn; J. Lachniet; J. M. Laget; D. Lawrence; G. A. Leksin; K. Loukachine; R. W. Major; J. J. Manak; C. Marchand; S. McAleer; J. W. McNabb; J. McCarthy; B. A. Mecking; M. D. Mestayer; C. A. Meyer; R. Minehart; M. Mirazita; R. Miskimen; V. Mokeev; S. Morrow; V. Muccifora; J. Mueller; L. Y. Murphy; G. S. Mutchler; J. Napolitano; S. O. Nelson; S. Niccolai; G. Niculescu; B. Niczyporuk; R. A. Niyazov; M. Nozar; G. V. O'Rielly; M. S. Ohandjanyan; A. Opper; M. Ossipenko; Y. Patois; G. A. Peterson; S. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; B. M. Preedom; J. W. Price; D. Protopopescu; L. M. Qin; B. A. Raue; G. Riccardi; G. Ricco; M. Ripani; B. G. Ritchie; S. Rock; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; K. Sabourov; C. W. Salgado; V. Sapunenko; M. Sargsyan; R. A. Schumacher; V. S. Serov; Y. G. Sharabian; J. Shaw; S. M. Shuvalov; S. Simionatto; A. Skabelin; E. S. Smith; L. C. Smith; T. Smith; D. I. Sober; L. Sorrell; M. Spraker; S. Stepanyan; P. Stoler; S. Taylor; D. Tedeschi; U. Thoma; R. Thompson; L. Todor; T. Y. Tung; C. Tur; M. F. Vineyard; A. Vlassov; K. Wang; L. B. Weinstein; H. Weller; R. Welsh; D. P. Weygand; S. Whisnant; M. Witkowski; E. Wolin; M. H. Wood; A. Yegneswaran; B. Zhang; J. Zhao; Z. Zhou

2003-01-01

293

Some features of spray breakup in effervescent atomizers  

NASA Astrophysics Data System (ADS)

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray is quantified in terms of the mean bubble bursting distance from the orifice. The parametric study indicates that the mean bubble bursting distance mainly depends on airflow rate, jet diameter and mixture velocity. It is also observed that the jet diameter has a dominant effect on the bubble bursting distance when compared to mixture velocity at a given airflow rate. The mean bubble bursting distance is shown to be governed by a nondimensional two-phase flow number consisting of all the aforementioned parameters. The location of bubble bursting is found to be highly unsteady spatially, which is influenced by flow dynamics inside the injector. It is proposed that this unsteadiness in jet breakup length is a consequence of varying degree of bubble expansion caused due to the intermittent occurrence of single phase and two-phase flow inside the orifice.

Gadgil, Hrishikesh P.; Raghunandan, B. N.

2011-02-01

294

Some features of spray breakup in effervescent atomizers  

NASA Astrophysics Data System (ADS)

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray is quantified in terms of the mean bubble bursting distance from the orifice. The parametric study indicates that the mean bubble bursting distance mainly depends on airflow rate, jet diameter and mixture velocity. It is also observed that the jet diameter has a dominant effect on the bubble bursting distance when compared to mixture velocity at a given airflow rate. The mean bubble bursting distance is shown to be governed by a nondimensional two-phase flow number consisting of all the aforementioned parameters. The location of bubble bursting is found to be highly unsteady spatially, which is influenced by flow dynamics inside the injector. It is proposed that this unsteadiness in jet breakup length is a consequence of varying degree of bubble expansion caused due to the intermittent occurrence of single phase and two-phase flow inside the orifice.

Gadgil, Hrishikesh P.; Raghunandan, B. N.

2010-07-01

295

Breakup of spectator residues in relativistic nuclear collisions  

NASA Astrophysics Data System (ADS)

Low energy nuclear fragments (12<=A<=140) from the bombardment of Au by high energy protons, 4He, and 20Ne projectiles are measured to yield information on the breakup of the target nucleus. We discuss the shapes of the fragment energy spectra across this broad range of fragment mass and pick out the fission component by its binary breakup. Multiplicities of coincident fast charged particles are presented as a measure of the degree of violence of the initial stage of the collision. Angular distribution of light fragments (8<=Z<=11) give the average velocities imparted to the residue in central collisions, and these values are compared to the results of cascade calculations. Measurements of slow fragment multiplicities from central events reveal a many-fragment final state. In the light of this finding we develop a simple calculation of the Coulomb features of the observed spectra. The applicability of a statistical breakup model is discussed. NUCLEAR REACTIONS Au(20Ne, heavy fragment) E=5, 8, 21, and 42 GeV; Au(4He, heavy fragment) E=5 GeV; Au(p, heavy fragment) E=4.9 GeV. Measured d2?dEd?, associated multiplicities of fast charged particles, binary coincidences, slow fragment multiplicities.

Warwick, A. I.; Wieman, H. H.; Gutbrod, H. H.; Maier, M. R.; Péter, J.; Ritter, H. G.; Stelzer, H.; Weik, F.; Freedman, M.; Henderson, D. J.; Kaufman, S. B.; Steinberg, E. P.; Wilkins, B. D.

1983-03-01

296

Transverse liquid fuel jet breakup, burning, and ignition  

SciTech Connect

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Li, H.

1990-12-31

297

17F breakup reactions: A touchstone for indirect measurements  

NASA Astrophysics Data System (ADS)

Dissociation has become an essential tool in several domains of nuclear physics. It provides useful information about the structure of halo nuclei, and Coulomb breakup can be used as an indirect method to measure radiative-capture cross sections at stellar energies. Though simple it may seem, this indirect technique relies on peculiar assumptions. Recent theoretical analyses of the Coulomb breakup of 8B have shown that these assumptions are not all satisfied. Whereas many experimental investigations on such a phenomenon have been conducted on 8B, the case of 17F has been poorly addressed up to now. An exclusive study of 17F breakup reactions has thus been performed at the FRIBs facility of the Laboratori Nazionali del Sud, Catania (Italy). The experimental setup and the detector systems allowed the measurement, event-by-event, of the X-Y coordinates of the interaction point on the target as well as the momenta and angles of all outgoing decay particles with a geometrical efficiency of 72% and a resolution of approximately 300 keV. The first results and preliminary model comparison are reported.

Sfienti, C.; Raciti, G.; Capel, P.; Baye, D.; De Napoli, M.; Giacoppo, F.; Rapisarda, E.; Cardella, G.; Descouvemont, P.; Mazzocchi, C.; Sparenberg, J.-M.

2011-09-01

298

Breakup of the Bell monopoly: Lessons for electric utilities  

SciTech Connect

Technological change, not regulatory change, was the prime mover behind the Bell breakup. Now, for the first time, technology threatens to recast the economic structure of the electric utility industry as well. Previous analyses of the restructuring of the telecommunications industry, as represented by the 1984 breakup of the Bell monopoly, focus on regulatory change as the precipitator and principal agent. Technology is recognized as an important factor but not the primary trigger. This view confounds the roles of the independent and dependent variables in the economic system. The mistake is more than misperception of a single, isolated event that is now over and done with; it is fundamental and it must be corrected in order to understand the implications that restructuring holds for electric utility monopolies. Technology, not regulation, was the primary trigger in the Bell System breakup. Technology acted as a virus, infecting the monopoly economics of telecommunications and in turn driving a complete transformation of that industry. Regulatory change was the consequence, not the cause.

Piepmeier, J.M. (James M. Piepmeier and Co., Evanston, IL (United States)); Jermain, D.O. (David O. Jermain Associates, Portland, OR (United States)); Egnor, T.L. (MicroGrid, Portland, OR (United States))

1993-07-01

299

Nuclear scattering of deuterons at 4. 3, 6. 3, and 8. 9 GeV\\/c  

Microsoft Academic Search

Momentum spectra of secondary deuterons from interactions of deuterons of momentum 4.3, 6.3, and 8.9 GeV\\/c with nuclei of carbon, aluminum, and bismuth have been measured at an angle 103 mrad. The results are analyzed in terms of the model of multiple nucleon-nucleon scattering. The observed momentum spectra of deuterons from dC collisions can be qualitatively reproduced on the assumption

L. S. Azhgirei; I. K. Vzorov; V. N. Zhmyrov; V. V. Ivanov; M. A. Ignatenko; A. S. Kuznetsov; M. G. Meshcheryakov; A. S. Pak; S. V. Rasin; G. D. Stoletov; A. V. Tarasov; C. Tseren

1979-01-01

300

Quark momentum-space charge distribution in deuteron and neutron\\/proton structure functions ratio  

Microsoft Academic Search

.  The aim of the present article is to extract the free neutron structure function, which is experimentally unknown, form proton\\u000a and deuteron deep inelastic scattering (DIS) data in the deep valence region. We begin by using the quark-exchange formalism,\\u000a deuteron wave function and Fermi motion effect to investigate the deep inelastic electron scattering from the deuteron. The\\u000a up- and down-quark

M. Modarres; M. M. Yazdanpanah; F. Zolfagharpour

2007-01-01

301

Precise Measurement of the Deuteron Elastic structure Function A(Q{sup 2})  

SciTech Connect

The A(Q{sup 2}) structure function in elastic electron-deuteron scattering was measured at six momentum transfers Q{sup 2} between 0.66 and 1.80 (GeV/c){sup 2} in Hall C at Jefferson Laboratory. The scattered electrons and recoil deuterons were detected in coincidence, at a fixed deuteron angle of 60.5{sup o}. These new precise measurements resolve discrepancies between older sets of data. They put significant constraints on existing models of the deuteron electromagnetic structure, and on the strength of isoscalar meson exchange currents.

D. Abbott; A. Ahmidouch; H. Anklin; J. Arvieux; J. Bail; S. Beedoe; E. J. Beise; L. Bimbot; W. Boeglin; H. Breuer; R. Carlini; N. S. Chant; S. Danagoulian; K. Dow; J.E. Ducret; J. Dunne; R. Ent; L. Ewell; L. Eyraud; C. Furget; M. Garcon; R. Gilman; C. Glashausser; P. Gucye; K. Gustafsson; K. Hafidi; A. Honegger; J. Jourdan; S. Kox; G. Kumbartzki; L. Lu; A. Lung; D. Mack; P. Markowitz; J. McIntyre; D. Meekins; F. Merchez; J. Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; L. Qin; R. Ransome; J.S. Real; P. G. Roos; P. Rutt; R. Sawafta; S. Stepanyan; R. Tieulent; E. Tomasi-Gustafsson; W. Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; W. Vulcan; C. Williamson; S. A. Wood; C. Yan; J. Zhao; W. Zhao

1999-02-15

302

Precise Measurement of the Deuteron Elastic Structure Function A(Q{sup 2 })  

SciTech Connect

The A(Q{sup 2}) structure function in elastic electron-deuteron scattering was measured at six momentum transfers Q{sup 2} between 0.66 and 1.80 (GeV/c){sup 2} in Hall C at Jefferson Laboratory. The scattered electrons and recoil deuterons were detected in coincidence, at a fixed deuteron angle of 60.5{degree}. These new precise measurements resolve discrepancies between older sets of data. They put significant constraints on existing models of the deuteron electromagnetic structure, and on the strength of isoscalar meson exchange currents. {copyright} {ital 1999} {ital The American Physical Society}

Ball, J.; Ducret, J.; Garcon, M.; Hafidi, K.; Pitz, D.; Tomasi-Gustafsson, E. [DAPNIA/SPhN, CEA/Saclay, 91191 Gif-sur-Yvette (France); Honegger, A.; Jourdan, J.; Zhao, J. [Basel Institut fur Physik, Basel (Switzerland); Beise, E.J.; Breuer, H.; Chant, N.S.; Ewell, L.; Gustafsson, K.; Lung, A.; Mohring, R.; Pitz, D.; Roos, P.G. [University of Maryland, College Park, Maryland 20742 (United States); Eyraud, L.; Furget, C.; Kox, S.; Lu, L.; Merchez, F.; Real, J.; Tieulent, R.; Voutier, E. [ISN, IN2P3-UJF, 38026 Grenoble (France); Abbott, D.; Carlini, R.; Dunne, J.; Ent, R.; Gilman, R.; Gueye, P.; Mack, D.; Meekins, D.; Mitchell, J.; Pitz, D.; Qin, L.; Vansyoc, K.; Volmer, J.; Vulcan, W.; Wood, S.A.; Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Gilman, R.; Glashausser, C.; Kumbartzki, G.; McIntyre, J.; Ransome, R.; Rutt, P. [Rutgers University, Piscataway, New Jersey 08855 (United States); Ahmidouch, A.; Dow, K.; Turchinetz, W.; Williamson, C.; Zhao, W. [MIT-Bates Linear Accelerator, Middleton, Massachusetts 01949 (United States); Anklin, H.; Boeglin, W.; Markowitz, P. [Florida International University, Miami, Florida 33199 (United States); Mrktchyan, H.; Stepanyan, S. [Yerevan Physics Institute, 375036 Yerevan (Armenia); Ahmidouch, A.; Beedoe, S.; Danagoulian, S.; Mtingwa, S.; Sawafta, R. [North Carolina A. T. State University, Greensboro, North Carolina 27411 (United States); Arvieux, J.; Ball, J.; Tomasi-Gustafsson, E. [LNS-Saclay, 91191 Gif-sur-Yvette (France); Arvieux, J.; Bimbot, L. [IPNO, IN2P3, BP 1, 91406 Orsay (France)

1999-02-01

303

Measurement of Tensor Polarization in Elastic Electron-Deuteron Scattering at Large Momentum Transfer  

SciTech Connect

Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c) 2. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q 2 the deuteron charge form factors GC and GQ. They are in good agreement with relativistic calculations and disagree with pQCD predictions.

David Abbott; A. Ahmidouch; H. Anklin; J. Arvieux; J. Ball; S. Beedoe; E.J. Beise; L. Bimbot; W. Boeglin; H. Breuer; R. Carlini; N.S. Chant; S. Danagoulian; K. Dow; J.-E. Ducret; J. Dunne; L. Ewell; L. Eyraud; C. Furget; M. Garcon; R. Gilman; C. Glashausser; P. Gueye; K. Gustafsson; K. Hadi; A. Honegger; J. Jourdan; S. Kox; G. Kumbartzki; L. Lu; A. Lung; D. Mack; P. Markowitz; J. McIntyre; D. Meekins; F. Merchez; J. Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; L. Qin; R.D. Ransome; J.-S. Real; P.G. Roos; P. Rutt; R. Sawafta; S. Stepanyan; R. Tieulent; E. Tomasi-Gustafsson; W. Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; W. Vulcan; C. Williamson; S.A. Wood; C. Yan; J. Zhao; W. Zhao

2000-05-01

304

Measurement of Tensor Polarization in Elastic Electron-Deuteron Scattering at Large Momentum Transfer  

SciTech Connect

Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c){sup 2}. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q{sup 2} the deuteron charge form factors G{sub C} and G{sub Q}. They are in good agreement with relativistic calculations and disagree with pQCD predictions.

David Abbott; Abdellah Ahmidouch; Heinz Anklin; Francois Arvieux; Jacques Ball; S. Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; James Dunne; Lars Ewell; Laurent Eyraud; Christophe Furget; Michel Garcon; Ronald Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; Adrian Honegger; Juerg Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; David Mack; Pete Markowitz; Justin McIntyre; David Meekins; Fernand Merchez; Joseph Mitchell; R. Mohring; Sekazi Mtingwa; Hamlet Mkrtchyan; David Pitz; Liming Qin; Ronald Ransome; Jean-Sebastien Real; Philip Roos; Paul Rutt; Reyad Sawafta; Samuel Stepanyan; Raphael Tieulent; Egle Tomasi-Gustafsson; William Turchinetz; Kelley Vansyoc; Jochen Volmer; Eric Voutier; William Vulcan; Claude Williamson; Stephen Wood; Chen Yan; Jie Zhao; Wenxia Zhao

2000-05-01

305

Oscillations and breakup of a bubble immersed in a turbulent field  

NASA Astrophysics Data System (ADS)

This work is an experimental study of the deformation and breakup of a bubble in a turbulent flow. A special facility was designed to obtain intense turbulence without significant mean flow. The experiments were performed under microgravity conditions to ensure that turbulence was the only cause of bubble deformation. A scalar parameter, characteristic of this deformation, was obtained by video processing of high-speed movies. The time evolution and spectral representation of this scalar parameter showed the dynamical characteristics of bubble deformation. The signatures of the eigenmodes of oscillation predicted by the linear theory were clearly observed and the predominance of the second mode was proved. In addition, numerical simulations were performed by computing the response of a damped oscillator to the measured turbulence forcing. Simulations and experiments were found to be in good agreement both qualitatively, from visual inspections of the signals, and quantitatively, from a statistical analysis. The role of bubble dynamics in the deformation process has been clarified. On the one hand, the time response of the bubble controls the maximum amount of energy which can be extracted from each turbulent eddy. On the other hand, the viscous damping limits the energy that the bubble can accumulate during its fluctuating deformation. Moreover, two breakup mechanisms have been identified. One mechanism results from the balance between two opposing dominant forces, and the other from a resonance oscillation. A new parameter, the mean efficiency coefficient, has been introduced to take into account the various aspects of bubble dynamics. Used together with the Weber number, this parameter allows the prediction of the occurrence of these two mechanisms. Finally, the influence of the residence time of the bubble on the statistics of the deformation has been analysed and quantified.

Risso, Frédéric; Fabre, Jean

1998-10-01

306

Comparing Nonperturbative Models of the Breakup of Neutron-Halo Nuclei  

SciTech Connect

Breakup reactions of loosely bound nuclei are often used to extract structure and/or astrophysical information. Here we compare three nonperturbative reaction theories often used when analyzing breakup experiments, namely the continuum discretized coupled channel model, the time-dependent approach relying on a semiclassical approximation, and the dynamical eikonal approximation. Our test case consists of the breakup of {sup 15}C on Pb at 68 MeV/nucleon and 20 MeV/nucleon.

Capel, P.; Esbensen, H.; Nunes, F. M. (Physics); (Michigan State Univ.); (Johannes Gutenberg-Univ.); (Univ. Libre de Bruxelles)

2012-01-01

307

Dynamics of bubble breakup in a microfluidic T-junction divergence  

Microsoft Academic Search

The aim of this work is to investigate experimentally the bubble breakup in a microfluidic T-junction divergence using a high-speed digital camera and a micro-Particle Image Velocimetry (micro-PIV) system. The breakup and non-breakup of N2 bubbles in glycerol–water mixtures with several concentrations of sodium dodecyl sulphate (SDS) as surfactant were studied with capillary number ranging from 0.001 to 0.1. The

Taotao Fu; Youguang Ma; Denis Funfschilling; Huai Z. Li

2011-01-01

308

Breakup of eutectic carbide network of white cast irons at high temperatures  

Microsoft Academic Search

The fracture toughness of white cast irons is related to the morphology of eutectic carbides,being better when isolated than when network-like. In this paper observations on the breakup of eutectic cementite network during annealing treatment of white cast irons are reported using a high temperature microscope and scanning electron microscopy (SEM). Dissolution-induced breakup and capillarity-induced breakup are identified. The former

Ma Qian; Liu Baicheng; Wang Zhaochang

1995-01-01

309

Fine structure of breakup development inferred from satellite and ground-based observations  

NASA Astrophysics Data System (ADS)

More than 60 breakups, including weak activations of the pseudo-breakup type, moderate breakups, and events of very strong auroral activity, were analyzed using ground-based TV data, together with satellite auroral images. We studied the fine subvisual details of spatial and temporal dynamics of active auroral forms and surrounding diffuse luminosity, both in the longitudinal and latitudinal directions of the TV camera field of view. For all types of breakups a close interconnection of auroral activity was found across and along the auroral oval.

Kornilova, T. A.; Kornilov, I. A.; Kornilov, O. I.

2008-05-01

310

Continental break-up in Ethiopia: results from the EAGLE experiment  

NASA Astrophysics Data System (ADS)

The rifting of continents and eventual formation of ocean basins is a fundamental component of plate tectonics, yet the mechanism for break-up has, until recently, been poorly understood. The East Africa Rift system (EARS) is an ideal place to study this process since it captures the initiation of a rift in the south through to incipient oceanic spreading in northern Ethiopia. Here we present the results of EAGLE (Ethiopia, Afar, Geoscientific, Lithospheric Experiment), a multi-disciplinary project that aimed to study the anatomy of a rift immediately prior to break-up. Also presented here are the results of a new P wave tomographic inversion for Ethiopia that utilizes broadband seismological data from both the EAGLE and Penn State University Ethiopia networks. With up to 100 stations, a network aperture of ~1000km, and more than three years of continuous seismic data, we are able to present the most detailed picture to date of the upper mantle velocity structure beneath a region of incipient lithospheric rupture. Mantle and crustal tomography studies, magnetotelluric, gravity, and seismic anisotropy studies all indicate localized zones of magma intrusion beneath the rift, with the shallowest levels of intrusion beneath the seismically and volcanically active tectono-magmatic segments in the rift valley. The intimate relationship between faulting and magmatism in the northern MER is strikingly similar to that of slow-spreading mid-ocean ridges, but without the hard linkage zones of transform faults. Seismological, gravity, magnetotelluric, geochemical and structural observations all point to fundamental modification of crust and upper mantle by magma intrusion during the syn-rift stage. These observations support models of magma assisted rifting, rather than those of simple mechanical stretching.

Bastow, I. D.; Ebinger, C. J.; Maguire, P. K.; Stuart, G. W.; Keller, G. R.; Kendall, J. M.; Klemperer, S. L.; Whaler, K. A.; Asfaw, L. M.; Nyblade, A. A.; Benoit, M. H.; Group, E. W.

2006-05-01

311

Temperature dependence of normal and quasi-deuteron pairing in asymmetric nuclear matter  

SciTech Connect

Nuclear matter calculations show the quasi-deuteron pairing mode to be the most important one and to furnish values of the pairing fields that are in reasonable agreement with the recent measurements. Here, we study the effects of temperature on normal and quasi-deuteron pairing in asymmetric nuclear matter, using a Bonn-type meson exchange interaction.

Dalmolin, F. T.; Carlson, B. V. [Depto. de Fisica, Instituto Tecnologico de Aeronautica, Sao Jose dos Campos SP (Brazil)

2009-06-03

312

{sup 6}He breakup dynamic polarization potential reexamined  

SciTech Connect

The dynamic polarization potential contribution to the effective interaction between {sup 6}He and {sup 208}Pb at 27 MeV, due to breakup channels, is recalculated exploiting a recently developed improved model for {sup 6}He. The most general features of the long-range attractive and absorptive components remain the same as were found in an earlier study, but the asymptotic magnitudes are reduced by factors of about 2.5 and 4.5, respectively. We draw conclusions from these results, as well as from further calculations at 22 MeV, closer to the Coulomb barrier, and at 32 MeV.

Mackintosh, R. S.; Keeley, N. [Department of Physics and Astronomy, Open University, Milton Keynes, MK7 6AA (United Kingdom); Department of Nuclear Reactions, Andrzej Soltan Institute for Nuclear Studies, Hoza 69, PL-00681 Warsaw (Poland)

2009-01-15

313

Multifragment emission and the experimental characterization of breakup reactions  

SciTech Connect

The production of three or more particles in nuclear reactions is discussed in terms of physically meaningful variables for the description of the asymptotic exit-channel configuration. The emphasis is placed in a direct comparison between these basic variables obtained in a purely experimental way and the corresponding results of generic model calculations. Applications of this approach to a few examples of recent inclusive and exclusive measurements of breakup reactions in the {sup 6,7}Li+{sup 144}Sm systems are presented.

Martinez Heimann, D.; Pacheco, A. J.; Arazi, A.; Fernandez Niello, J. O.; Figueira, J. M.; Negri, A. [Departamento de Fisica-Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Capurro, O. A.; Carnelli, P.; Cardona, M. A.; Barbara, E. de; Fimiani, L.; Hojman, D. L.; Marti, G. V. [Departamento de Fisica-Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina)

2010-08-04

314

Beam Breakup Studies for New Cryo-Unit  

SciTech Connect

In this paper, we report the numerical simulations of cumulative beam breakup studies for a new cryo-unit for booster design at Jefferson lab. The system consists of two 1-cell and one 7-cell superconducting RF cavities. Combining two 1-cell into a 2-cell together with a 7-cell is also an option. Simulations have been performed using the 2-dimensional time-domain code. The 1-cell+1-cell+7-cell combination confirms beam stability, however, the arrangement 2-cell+7-cell shows instability.

S. Ahmed, I. Shin, R. Kazimi, F. Marhauser ,F. Hannon ,G. Krafft ,B. Yunn ,A. Hofler

2011-03-01

315

The Breakup of Temperature Inversions In Steep Valleys  

NASA Astrophysics Data System (ADS)

The purpose of this research is to model and provide a better understanding of tem- perature inversions breakup in steep valleys. The Advanced Regional Prediction Sys- tem (ARPS), a three-dimensional, compressible, and non-hydrostatic modeling tool developed by the Center for Analysis and Prediction of Storms at the University of Oklahoma was used. Many field studies indicate that the evolution of the convective and inversion layers are strongly dependant on the surrounding topography. In relatively open valleys, the convective boundary layer usually grows from the bottom of the valley while in steeper cases, the upslope morning winds affects the dynamic of the mixing layer resulting in the destruction of the inversion from its bottom and its top (see Whiteman 1980). ARPS allows one to perform accurate simulation of such situations. First, written in terrain following coordinates, it handles steep topographies; then its extensive radi- ation and surface flux packages provide a good treatment of land related processes. Moreover, ARPS accounts for the incidence angle of sunrays, differencing the ex- posed and non-exposed mountain slopes. However, it neglects the topographic shade which can delay the sunrise of a hour or more in steep valleys. A new subroutine described by Colette etal. 2002 is thus used to compute the projected shade on the surrounding topography. Simulations of temperature inversion breakup for various two-dimensional valleys are presented. The time scale of evolution of the mixing layer is in good agreement with field studies and, as expected, the convective boundary layer shows an asymmetry between east and west facing slopes. The different patterns of inversion breakup doc- umented by Whiteman are also reproduced. These simulations of idealized cases give a better understanding of inversion breakup in steep valleys. Our code is now being applied to a real case: the study of a peculiar wind, la Ora del Garda, caused by the interaction between a lake breeze and a valley wind in the Garda Valley (Northern Italy). Preliminary simulations will be presented. The support of AC by TotalFinaElf and RS by the Physical Meteorology Program of NSF and the VTMX Program of DoE is appreciated.

Colette, A.; Street, R.

316

Obstructed breakup of slender drops in a microfluidic T junction.  

PubMed

In this Letter we present a theoretical analysis of the droplet breakup with "permanent obstruction" in a microfluidic T junction [M.-C. Jullien et al., Phys. Fluids 21, 072001 (2009)]. The proposed theory is based on a simple geometric construction for the interface shape combined with Tanner's law for the local contact angle. The resulting scaling of the droplet deformation with time and capillary number is in excellent agreement with the results of direct numerical simulations and prior experiments. More rigorous analysis based on the lubrication approximation reveals a self-similar behavior analogous to the classical problem of a droplet spreading over a preexisting liquid film. PMID:23004987

Leshansky, A M; Afkhami, S; Jullien, M-C; Tabeling, P

2012-06-26

317

Viscous droplet deformation and breakup in microfluidic cross-flows  

NASA Astrophysics Data System (ADS)

The dynamic response of translating high-viscosity droplets is experimentally investigated by means of a sharp increase of the flow velocity in a microchannel junction. The additional local injection of the continuous phase from symmetric side-channels into a square microchannel produces a broad range of time-dependent deformations and breakup. In particular, due to microscale wall confinement, the system displays a non-linear behavior with the initial droplet size. Deformations, relaxation times, and fragmentation processes are examined as a function of flow and fluids properties with a particular emphasis on the formation of slender viscous structures and spoon-like droplets, i.e., asymmetrical droplets.

Cubaud, Thomas

2009-03-01

318

Core excitation effects in the breakup of halo nuclei  

NASA Astrophysics Data System (ADS)

The role of core excitation in the structure and dynamics of two-body halo nuclei is investigated. We present calculations for the resonant breakup of 11Be on protons at an incident energy of 63.7 MeV/nucleon, where core excitation effects were shown to be important. To describe the reaction, we use a recently developed extension of the DWBA formalism which incorporates these core excitation effects within the no-recoil approximation. The validity of the no-recoil approximation is also examined by comparing with DWBA calculations which take into account core recoil. In addition, calculations with two different continuum representations are presented and compared.

Moro, A. M.; de Diego, R.; Lay, J. A.; Crespo, R.; Johnson, R. C.; Arias, J. M.; Gómez-Camacho, J.

2012-10-01

319

Core excitation effects in the breakup of halo nuclei  

SciTech Connect

The role of core excitation in the structure and dynamics of two-body halo nuclei is investigated. We present calculations for the resonant breakup of {sup 11}Be on protons at an incident energy of 63.7 MeV/nucleon, where core excitation effects were shown to be important. To describe the reaction, we use a recently developed extension of the DWBA formalism which incorporates these core excitation effects within the no-recoil approximation. The validity of the no-recoil approximation is also examined by comparing with DWBA calculations which take into account core recoil. In addition, calculations with two different continuum representations are presented and compared.

Moro, A. M.; Diego, R. de; Lay, J. A.; Crespo, R.; Johnson, R. C.; Arias, J. M.; Gomez-Camacho, J. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal) and Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Prof. Cavaco Silva, Taguspark (Portugal); Physics Department, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain) and Centro Nacional de Aceleradores, Universidad de Sevilla/Junta de Andalucia, E-41092 Sevilla (Spain)

2012-10-20

320

Deuteron Quadrupole Coupling Constant in CH3D  

Microsoft Academic Search

The deuteron electric-field gradient qD and quadrupole coupling constant (eqQ\\/h)D for CH3D have been calculated from extended basis-set LCAO-MO-SCF wavefunctions determined by Woznick for this system. Comparison of the results for different wavefunctions and different distances suggest that a reasonable theoretical estimate is (eqQ\\/h)D=210±30 kc\\/sec. Since this disagrees significantly with the present experimental estimate [(eqQ\\/h)D=100±50 kc\\/sec], a more refined measurement

T. Caves; M. Karplus

1966-01-01

321

Deuteron matrix elements in chiral effective theory at leading order  

NASA Astrophysics Data System (ADS)

We consider matrix elements of two-nucleon operators that arise in chiral effective theories of the two-nucleon system. Generically, the short-distance piece of these operators scales as 1/r, with r the relative separation of the two nucleons. We show that, when evaluated between the leading-order wave functions obtained in this effective theory, these two-nucleon operators are independent of the cutoff used to renormalize the two-body problem for n=1 and 2. However, for n?3 general arguments about the short-distance behavior of the leading-order deuteron wave function show that the matrix element will diverge.

Platter, L.; Phillips, D. R.

2006-10-01

322

Parity violation in radiative neutron capture on the deuteron  

NASA Astrophysics Data System (ADS)

Parity-violating (PV) effects in neutron-deuteron radiative capture are studied using Desplanques, Donoghue, and Holstein (DDH) and effective field theory weak potentials. The values of PV effects are calculated using wave functions, obtained by solving three-body Faddeev equations in configuration space for realistic strong potentials. The relations between physical observables and low-energy constants are presented, and dependencies of the calculated PV effects on strong and weak potentials are discussed. The presented analysis shows the possible reason for the existing discrepancy in PV nuclear data analysis using the DDH approach and reveals a new opportunity to study short-range interactions in nuclei.

Song, Young-Ho; Lazauskas, Rimantas; Gudkov, Vladimir

2012-10-01

323

Tensor polarization in pion-deuteron elastic scattering  

NASA Astrophysics Data System (ADS)

Angular distributions of the deuteron tensor polarization, t20, in ?-d elastic scattering have been measured at pion energies of 180, 220, and 256 MeV. The experiment and analysis are described in detail. Theoretical calculations in which the effects of pion absorption on the elastic channel are small seem to reproduce the data. An excitation function was measured in order to search for a rap- id energy dependence of t20. No rapid angular or energy dependence was found near a pion energy of 134 MeV, where other experiments have suggested the existence of dibaryon resonances.

Ungricht, E.; Freeman, W. S.; Geesaman, D. F.; Holt, R. J.; Specht, J. R.; Zeidman, B.; Stephenson, E. J.; Moses, J. D.; Farkhondeh, M.; Gilad, S.; Redwine, R. P.

1985-03-01

324

Tensor electric polarizability of the deuteron in storage-ring experiments  

SciTech Connect

The tensor electric polarizability of the deuteron gives important information about spin-dependent nuclear forces. If a resonant horizontal electric field acts on a deuteron beam circulating into a storage ring, the tensor electric polarizability stimulates the buildup of the vertical polarization of the deuteron (the Baryshevsky effect). General formulas describing this effect have been derived. Calculated formulas agree with the earlier obtained results. The problem of the influence of tensor electric polarizability on spin dynamics in such a deuteron electric-dipole-moment experiment in storage rings has been investigated. Doubling the resonant frequency used in this experiment dramatically amplifies the Baryshevsky effect and provides the opportunity to make high-precision measurements of the deuteron's tensor electric polarizability.

Silenko, Alexander J. [Institute of Nuclear Problems, Belarusian State University, Minsk 220080 (Belarus)

2007-01-15

325

The study of the reduced ?-width and ANC of 16O states through its sequential breakup  

Microsoft Academic Search

In this work we theoretically study using continuum-discretized-coupled channel (CDCC) theory, the resonant breakup of 16O by comparison with a recent measurement. The ground state Asymptotic Normalization Coefficient (ANC) and the alpha spectroscopic factor of 16O are evaluated in this work. The peripheral aspect of resonance breakup through a 2+ unbound state has been also studied.

Sucheta Adhikari; Chinmay Basu

2009-01-01

326

An investigation of soft launch and instability breakup with a two-stage light gas gun  

SciTech Connect

Exploratory research has been performed in the use of a two-stage light gas gun facility to investigate the soft acceleration and breakup physics of rapidly launched thin plates. A flash radiograph system was joined with the gun facility to provide the principal diagnostic. In the study, radiographs of thin-plate acceleration and breakup were obtained.

Grady, D.E.; Moody, R.L.

1988-05-01

327

An investigation of soft launch and instability breakup with a two-stage light gas gun  

Microsoft Academic Search

Exploratory research has been performed in the use of a two-stage light gas gun facility to investigate the soft acceleration and breakup physics of rapidly launched thin plates. A flash radiograph system was joined with the gun facility to provide the principal diagnostic. In the study, radiographs of thin-plate acceleration and breakup were obtained.

D. E. Grady; R. L. Moody

1988-01-01

328

Effects of Spring Breakup on Microscale Air Temperatures in the Mackenzie River Delta  

Microsoft Academic Search

The effects of spring breakup on microscale air temperatures in the Mackenzie River delta were investigated by means of intervention analysis. Small but statistically significant increases in temperatures were detected for some areas within the delta and appeared to be related to ice breakup events in nearby channels and lake systems. The magnitude of the temperature increase appeared to be

STANLEY M. HIRST

1984-01-01

329

Bouncing Back from a Breakup: Attachment, Time Perspective, Mental Health, and Romantic Loss  

Microsoft Academic Search

Coping with a romantic breakup is a normal developmental task of emerging adulthood. Because of their role in influencing interpersonal relationships and adjustment, attachment history and time perspectives may influence resilience to romantic loss. In an online survey of 1,404 university students ages 18–25 who reported experiencing recent breakups, individuals with secure parental bonding, past positive time orientation, and lower

Steven P. Gilbert; Sarah K. Sifers

2011-01-01

330

Relationships between ice breakup dates of lakes and local air temperature on the Eurasian continent  

Microsoft Academic Search

Ice breakup dates on lakes are related to the local air temperature, and are useful for understanding the local climate. However, little study has been done on lakes on the Eurasian continent. Therefore, an ice breakup date estimation method, using water temperature trend and threshold surface temperature and aided by satellite remote sensing, was developed in our previous study in

T. Nonaka; T. Matsunaga; A. Hoyano

2007-01-01

331

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry  

Microsoft Academic Search

Using high-speed video, we have studied air bubbles detaching from an underwater nozzle. As a bubble distorts, it forms a thin neck which develops a singular shape as it pinches off. As in other singularities, the minimum neck radius scales with the time until the breakup. However, because the air-water interfacial tension does not drive the breakup, even small initial

Nathan C. Keim; Peder Møller; Wendy W. Zhang; Sidney R. Nagel

2006-01-01

332

The breakup of levitating water drops observed with a high speed camera  

Microsoft Academic Search

A wind tunnel was used to interact water drops and were recorded using a high speed camera. Three distinct collisional breakup types were observed and the drop size spectra from each were analysed for comparison with parameterisations constructed by Low and List (1982a). The spectra predicted by the parameterisations did not accurately correlate with the observed breakup distributions for each

C. Emersic; P. J. Connolly

2011-01-01

333

The breakup of levitating water drops observed with a high speed camera  

NASA Astrophysics Data System (ADS)

Collision-induced water drop breakup in a vertical wind tunnel was observed using a high speed camera for interactions between larger drop sizes (up to 7 mm diameter) than have previously been experimentally observed. Three distinct collisional breakup types were observed and the drop size distributions from each were analysed for comparison with predictions of fragment distributions from larger drops by two sets of established breakup parameterisations. The observations showed some similarities with both parameterisations but also some marked differences for the breakup types that could be compared, particularly for fragments 1 mm and smaller. Modifications to the parameterisations are suggested and examined. Presented is also currently the largest dataset of bag breakup distributions observed. Differences between this and other experimental research studies and modelling parameterisations, and the associated implications for interpreting results are discussed. Additionally, the stochastic coalescence and breakup equation was solved computationally using a breakup parameterisation, and the evolving drop-size distribution for a range of initial conditions was examined. Initial cloud liquid water content was found to have the greatest influence on the resulting distribution, whereas initial drop number was found to have relatively little influence. This may have implications when considering the effect of aerosol on cloud evolution, raindrop formation and resulting drop size distributions. Calculations presented show that, using an ideal initial cloud drop-size distribution, ~1-3% of the total fragments are contributed from collisional breakup between drops of 4 and 6 mm.

Emersic, C.; Connolly, P. J.

2011-10-01

334

Breakup of a bubble into a convergent-divergent pipe flow  

Microsoft Academic Search

We present the results of experiments study on the dynamics a bubble into a convergent-divergent pipe flow. The amplitude of the constriction and the magnitude of the flow may result in the breakup of the bubble. The occurrence of a liquid high speed jet in the direction of the flow as an initial step of the bubble breakup is reported

Jorge Peixinho; Kazuhiro Hashiguchi; Shu Takagi; Yoichiro Matsumoto

2007-01-01

335

Breakup time and morphology of drops and bubbles in a high-Reynolds-number flow  

Microsoft Academic Search

The breakup process of a drop or a bubble immersed in a straining flow at high Reynolds numbers, is studied numerically with the aim at comparing the breakup frequencies obtained with those measured in real flows. We assume that both the inner and the outer velocity fields are axisymmetric and irrotational. Under these assumptions the time evolution of the drop's

J. Rodríguez-Rodríguez; J. M. Gordillo; C. Martínez-Bazán

2006-01-01

336

Breakup reactions of the halo nuclei 11Be and 8B  

Microsoft Academic Search

We calculate the nuclear induced breakup of 11Be and 8B using a more realistic treatment of the diffraction and stripping processes than in previous work. The breakup is treated in the eikonal approximation with a profile function calculated from a realistic optical potential at low energies and from free nucleon-nucleon cross sections at high energies. This treatment gives a good

Kai Hencken; George Bertsch; Henning Esbensen

1996-01-01

337

Break-up of New Orleans Households after Hurricane Katrina  

PubMed Central

Theory and evidence on disaster-induced population displacement have focused on individual and population-subgroup characteristics. Less is known about impacts on households. I estimate excess incidence of household break-up due to Hurricane Katrina by comparing a probability sample of pre-Katrina New Orleans resident adult household heads and non–household heads (N = 242), traced just over a year later, with a matched sample from a nationally representative survey over an equivalent period. One in three among all adult non–household heads, and one in two among adult children of household heads, had separated from the household head 1 year post-Katrina. These rates were, respectively, 2.2 and 2.7 times higher than national rates. A 50% higher prevalence of adult children living with parents in pre-Katrina New Orleans than nationally increased the hurricane’s impact on household break-up. Attention to living arrangements as a dimension of social vulnerability in disaster recovery is suggested.

Rendall, Michael S.

2011-01-01

338

Beam-breakup calculations for the DARHT accelerator  

SciTech Connect

We have modeled an induction linac that will accelerate a 4-MeV, 3-kA beam of electrons to 16- to 20-MeV in 64 gaps. To suppress beam- breakup (BBU) instabilities induced by excitation of rf deflecting modes, the growth factor {Gamma} must be kept sufficiently small (e.g. < 3). On prototype DARHT cavities, rf measurements have shown that the normally degenerate TM modes are split in frequency by the asymmetry that the two pulsed-power drive rods present to the cavity. If half the cavities had vertical and half had horizontal drive-rod orientations, the effective number of gaps would be reduced by half if there were no coupling between the modes by the solenoidal focusing and if the split modes had no overlap. The LLNL code BREAKUP was used to study BBU growth for drive rod alternation patterns of blocks of 1, 2, 4, 8, 16, 24, 32, or 64 (no alternation) for both constant and alternating polarity solenoids. For alternating polarities the optimum alternation pattern is 2 or 4, whereas for constant polarities BBU is approximately independent of pattern. 9 refs., 5 figs. 2 tabs.

Allison, P.; Burns, M.J. (Los Alamos National Lab., NM (USA)); Caporaso, G.J.; Cole, A.G. (Lawrence Livermore National Lab., CA (USA))

1991-01-01

339

Breakup Reaction Models for Two- and Three-Cluster Projectiles  

NASA Astrophysics Data System (ADS)

Breakup reactions are one of the main tools for the study of exotic nuclei, and in particular of their continuum. In order to get valuable information from measurements, a precise reaction model coupled to a fair description of the projectile is needed. We assume that the projectile initially possesses a cluster structure, which is revealed by the dissociation process. This structure is described by a few-body Hamiltonian involving effective forces between the clusters. Within this assumption, we review various reaction models. In semiclassical models, the projectile-target relative motion is described by a classical trajectory and the reaction properties are deduced by solving a time-dependent Schrödinger equation. We then describe the principle and variants of the eikonal approximation: the dynamical eikonal approximation, the standard eikonal approximation, and a corrected version avoiding Coulomb divergence. Finally, we present the continuum-discretized coupled-channel method (CDCC), in which the Schrödinger equation is solved with the projectile continuum approximated by square-integrable states. These models are first illustrated by applications to two-cluster projectiles for studies of nuclei far from stability and of reactions useful in astrophysics. Recent extensions to three-cluster projectiles, like two-neutron halo nuclei, are then presented and discussed. We end this review with some views of the future in breakup-reaction theory.

Baye, D.; Capel, P.

340

Distribution of living Cupressaceae reflects the breakup of Pangea  

PubMed Central

Most extant genus-level radiations in gymnosperms are of Oligocene age or younger, reflecting widespread extinction during climate cooling at the Oligocene/Miocene boundary [?23 million years ago (Ma)]. Recent biogeographic studies have revealed many instances of long-distance dispersal in gymnosperms as well as in angiosperms. Acting together, extinction and long-distance dispersal are likely to erase historical biogeographic signals. Notwithstanding this problem, we show that phylogenetic relationships in the gymnosperm family Cupressaceae (162 species, 32 genera) exhibit patterns expected from the Jurassic/Cretaceous breakup of Pangea. A phylogeny was generated for 122 representatives covering all genera, using up to 10,000 nucleotides of plastid, mitochondrial, and nuclear sequence per species. Relying on 16 fossil calibration points and three molecular dating methods, we show that Cupressaceae originated during the Triassic, when Pangea was intact. Vicariance between the two subfamilies, the Laurasian Cupressoideae and the Gondwanan Callitroideae, occurred around 153 Ma (124–183 Ma), when Gondwana and Laurasia were separating. Three further intercontinental disjunctions involving the Northern and Southern Hemisphere are coincidental with or immediately followed the breakup of Pangea.

Mao, Kangshan; Milne, Richard I.; Zhang, Libing; Peng, Yanling; Liu, Jianquan; Thomas, Philip; Mill, Robert R.; S. Renner, Susanne

2012-01-01

341

Beam-breakup instability theory for energy recovery linacs  

NASA Astrophysics Data System (ADS)

Here we will derive the general theory of the beam-breakup instability in recirculating linear accelerators, in which the bunches do not have to be at the same rf phase during each recirculation turn. This is important for the description of energy recovery linacs where bunches are recirculated at a decelerating phase of the rf wave and for other recirculator arrangements where different rf phases are of an advantage. Furthermore it can be used for the analysis of phase errors of recirculated bunches. It is shown how the threshold current for a given linac can be computed and a remarkable agreement with tracking data is demonstrated. The general formulas are then analyzed for several analytically solvable cases, which show (a) why different higher order modes (HOMs) in one cavity do not couple so that the most dangerous modes can be considered individually; (b) how different HOM frequencies have to be in order to consider them separately; (c) that no optics can cause the HOMs of two cavities to cancel; (d) how an optics can avoid the addition of the instabilities of two cavities; and (e) how a HOM in a multiple-turn recirculator interferes with itself. Furthermore, a simple method to compute the orbit deviations produced by cavity misalignments has also been introduced. It is shown that the beam-breakup instability always occurs before the orbit excursion becomes very large.

Hoffstaetter, Georg H.; Bazarov, Ivan V.

2004-05-01

342

Break-up of New Orleans Households after Hurricane Katrina.  

PubMed

Theory and evidence on disaster-induced population displacement have focused on individual and population-subgroup characteristics. Less is known about impacts on households. I estimate excess incidence of household break-up due to Hurricane Katrina by comparing a probability sample of pre-Katrina New Orleans resident adult household heads and non-household heads (N = 242), traced just over a year later, with a matched sample from a nationally representative survey over an equivalent period. One in three among all adult non-household heads, and one in two among adult children of household heads, had separated from the household head 1 year post-Katrina. These rates were, respectively, 2.2 and 2.7 times higher than national rates. A 50% higher prevalence of adult children living with parents in pre-Katrina New Orleans than nationally increased the hurricane's impact on household break-up. Attention to living arrangements as a dimension of social vulnerability in disaster recovery is suggested. PMID:21709733

Rendall, Michael S

2011-06-01

343

Projectile breakup dynamics for 6Li + 59Co : Kinematical analysis of ? - d coincidences  

NASA Astrophysics Data System (ADS)

A study of the kinematics of the ? - d coincidences in the 6Li + 59Co system at a bombarding energy of E lab = 29.6 MeV is presented. With exclusive measurements performed over different angular intervals it is possible to identify the respective contributions of the sequential and direct projectile breakup components. The angular distributions of both breakup components are fairly well described by the Continuum-Discretized Coupled-Channels framework (CDCC). Furthermore, a careful analysis of these processes using a semiclassical approach provides information on both their lifetime and their distance of occurrence with respect to the target. Breakup to the low-lying (near-threshold) continuum is delayed, and happens at large internuclear distances. This suggests that the influence of the projectile breakup on the complete fusion process can be related essentially to the direct breakup to the 6Li high-lying continuum spectrum.

Souza, F. A.; Carlin, N.; Beck, C.; Keeley, N.; Diaz-Torres, A.; Liguori Neto, R.; Siqueira-Mello, C.; de Moura, M. M.; Munhoz, M. G.; Oliveira, R. A. N.; Del Santo, M. G.; Suaide, A. A. P.; Szanto, E. M.; Szanto de Toledo, A.

2010-05-01

344

Fine structure of auroras during auroral breakup according to the ground-based and satellite observations  

NASA Astrophysics Data System (ADS)

The dynamics and fine structure of auroras before and during 60 auroral breakups, including pseudobreakups and breakups at moderate and high auroral activity, have been studied using the developed method for processing television images. The IMAGE and POLAR satellite and simultaneous ground images of auroras, ground magnetic data, and measurements of IMF and solar wind plasma parameters have been analyzed. The signatures that can be precursors of breakup have been found out in the auroral dynamics and morphology in the spatial—temporal vicinity of breakup. The morphological characteristics of auroral structures have been analyzed statistically. The directions of motion of weak subvisual structures have been determined. The velocities of motion of such structures are presented. The relation of the initial auroral arc bright-ening during breakups and pseudobreakups to the beginning of magnetic activation and formation of rayed structures has been analyzed.

Kornilov, I. A.; Antonova, E. E.; Kornilova, T. A.; Kornilov, O. I.

2008-02-01

345

Fragment angular correlation in the breakup of 16O ions at 95 MeV/A  

NASA Astrophysics Data System (ADS)

Fragment angular correlations in projectile breakup reactions are very sensitive to interference between different multipolarities entering in the excitation-dissociation process of the projectile. In particular, it was proposed to disentangle L=1 and L=2 contributions in direct breakup reactions of 16O with low relative energy between the ? and 12C fragment, which are of astrophysical interest. We studied the experimental aspects of extracting those angular correlations in extreme kinematical conditions usually encountered in breakup experiments of astrophysical interest. The breakup of 95 MeV/A 16O projectiles induced by a 208Pb target was measured using the high-resolution spectrometer SPEG at Ganil for the coincident detection of the fragments. Sequential breakup via the 12.53 MeV level of 16O is analyzed in this framework and it favors an one-step M2 excitation of this level.

Tatischeff, V.; Kiener, J.; Aguer, P.; Bogaert, G.; Coc, A.; Disdier, D.; Ichihara, T.; Kraus, L.; Lefebvre, A.; Linck, I.; Mittig, W.; Motobayashi, T.; de Oliveira Santos, F.; Roussel-Chomaz, P.; Stephan, C.; Thibaud, J. P.

1998-04-01

346

Experimental investigation on cellular breakup of a planar liquid sheet from an air-blast nozzle  

NASA Astrophysics Data System (ADS)

The cellular breakup phenomenon is investigated experimentally for a planar liquid sheet from an air-blast nozzle. The dominant sinuous wave growing spatially downstream forms complicated cellular structures of perforated thin films and surrounding ligaments. Several characteristic parameters are measured from photographic images and compared with linear temporal analysis. The dominant wavelength is proportional to the inverse square of the relative velocity between air and liquid. The estimated breakup time matches the growth time of the most unstable wave, while the breakup length corresponds to a product of breakup time and liquid velocity. Numerical simulation shows a substantially reduced mean effective velocity near flow reattachment region of the air stream. Air turbulence seems to play a major role on initial perturbations of cellular breakup in the given nozzle configuration. The measured spatial growth rates are always less than linear predictions due to deviation from the linear regime at higher amplitudes.

Park, Jaewan; Huh, Kang Y.; Li, Xianguo; Renksizbulut, Metin

2004-03-01

347

Study of charged pion photoproduction on deuteron and proton  

NASA Astrophysics Data System (ADS)

Pion photoproduction on nucleon and nuclei is an important tool to explore hadron structure and meson-baryon interaction. Charged pion production ?d->?^- pp and ?d->?^+?^-np with E?from 0.67 to 1.1 GeV, and ?p->?^+?^- p with E?from 0.67 to 0.92 GeV were measured with the second generation of Neutral Kaon Spectrometer, and tagged photon facility at the Laboratory of Nuclear Science, Tohoku University. The aim is to investigate the pion photoproduction process on the nucleus in the second and third resonance regions. The quasi-free process on bound proton and neutron inside deuteron and also non-quasi-free contributions were derived individually. The study on the proton follows our previous research with E?from 0.8 to 1.1 GeV.The excitation function of ?d->?^-pp will be reported with an energy bin of 6 MeV. This will be an improvement on the world data with the energy resolution of 10 MeV. A new method of the tagged photon energy calibration using the kinematically complete measurement of d(?, ?^- pp) will be introduced. The ?^+?^- photoproduction on bound proton in deuteron will be reported. The cross sections for ?d->?^+?^-np reaction with intermediate double delta channel were derived. This reaction is one of the important non-quasi-free processes, and is expected to be relevant to the ABC effect.

Han, Yuncheng

2009-10-01

348

Spin manipulating vector & tensor polarized deuterons stored in COSY  

NASA Astrophysics Data System (ADS)

We recently studied the spin manipulation of a simultaneously vector and tensor polarized deuteron beam stored at 1.85 GeV/c in the COSY Cooler Synchrotron. Using the EDDA detector, we first calibrated the vector and tensor analyzing powers, which were earlier unmeasured at 1.85 GeV/c; this allowed us to measure the absolute values of both the vector and tensor polarizations. Then we manipulated the deuteron's polarization by sweeping the frequency of a ferrite rf dipole through an rf-induced spin resonance. We first experimentally determined the resonance's frequency and then varied the rf dipole's frequency sweep range ?f and frequency ramp time ?t to maximize the spin-flip efficiency. We then obtained a measured vector spin-flip efficiency of 98.5 ± 0.3% [1]. We also studied, in detail, the behavior of the tensor polarization during spin manipulation; these new data may allow a better understanding of the interesting quantum behavior of spin-1 bosons. This research was supported by the German BMBF Science Ministry. [1] V.S. Morozov et al., Phys. Rev. ST Accel. Beams 8, 061001 (2005).

Morozov, V. S.; Krisch, A. D.; Leonova, M. A.; Raymond, R. S.; Sivers, D. W.; Wong, V. K.; Yonehara, K.; Gebel, R.; Lehrach, A.; Lorentz, B.; Maier, R.; Prasuhn, D.; Schnase, A.; Stockhorst, H.; Eversheim, D.; Hinterberger, F.; Rohdjess, H.; Ulbrich, K.

2006-04-01

349

Photodisintegration of the Deuteron at 20 MeV  

NASA Astrophysics Data System (ADS)

This dissertation describes the measurements of the differential cross section for the d( g? , n)p reaction performed using 20 MeV circularly polarized photons from the High Intensity gamma-ray Source (HIGS) located at the Duke Free Electron Laser Laboratory. The circularly polarized photons were incident on D2 O targets of differing lengths and the ejected neutrons were detected using the Blowfish neutron detector array. As the photodisintegration process breaks up the deuteron into only two particles, one neutron and one proton, and no other reaction channels have been conclusively demonstrated to exist below pion threshold, the measurement of the emitted neutron yields a direct measurement of the deuteron disintegration cross section. The differential cross section was expanded in terms of associated Legendre polynomial functions. Each term was simulated and fitted to the experimental data. The results were compared to the predictions of Arenhovel et al. Several systematic checks were also made on the data to help us understand the beam, target, and detector characteristics in preparation for planned experiments to test the Gerasimov-Drell-Hearn (GDH) sum rule using a dynamically polarized target to measure the spin-polarized d?(g? , n)p total cross sections. The GDH measurement is a high priority measurement for the HIGS collaboration.

Kucuker, Serpil

350

Generation of Radioisotopes with Accelerator Neutrons by Deuterons  

NASA Astrophysics Data System (ADS)

A new system proposed for the generation of radioisotopes with accelerator neutrons by deuterons (GRAND) is described by mainly discussing the production of 99Mo used for nuclear medicine diagnosis. A prototype facility of this system consists of a cyclotron to produce intense accelerator neutrons from the \\text{natC(d,n) reaction with 40 MeV 2 mA deuteron beams, and a sublimation system to separate \\text{99mTc from an irradiated 100MoO3 sample. About 8.1 TBq/week of 99Mo is produced by repeating irradiation on an enriched 100Mo sample (251 g) with accelerator neutrons for two days three times. It meets about 10% of the 99Mo demand in Japan. The characteristic feature of the system lies in its capability to reliably produce a wide variety of high-quality, carrier-free, carrier-added radioisotopes with a minimum level of radioactive waste without using uranium. The system is compact in size, and easy to operate; therefore it could be used worldwide to produce radioisotopes for medical, research, and industrial applications.

Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Sato, Nozomi; Kawabata, Masako; Harada, Hideo; Kin, Tadahiro; Tsukada, Kazuaki; Sato, Tetsuya K.; Minato, Futoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Seki, Yohji; Yokoyama, Kenji; Shiina, Takehiko; Ohta, Akio; Takeuchi, Nobuhiro; Kawauchi, Yukimasa; Sato, Norihito; Yamabayashi, Hisamichi; Adachi, Yoshitsugu; Kikuchi, Yuji; Mitsumoto, Toshinori; Igarashi, Takashi

2013-06-01

351

Asymptotic behavior of the deuteron form factors in the two-nucleon model and electron scattering experiments at GeV energies at JLab  

NASA Astrophysics Data System (ADS)

Using the instant form dynamics of Poincaré invariant quantum mechanics and the modified relativistic impulse approximation proposed previously, we calculate asymptotic behavior of electromagnetic form factors for the deuteron considered as a two-nucleon system. We show that today, experimentation on elastic ed scattering has reached the asymptotic regime. We also estimate the possible range of momentum transfer in which the quark degrees of freedom will possibly be seen in future JLab experiments. The explicit relation between the behavior of the deuteron wave function at r=0 and the form factors asymptotic behavior is obtained, and the conditions of wave functions that give the asymptotic behavior predicted by QCD and quark counting rules are formulated.

Krutov, A. F.; Troitsky, V. E.; Tsirova, N. A.

2008-10-01

352

Breakup and early seafloor spreading between India and Antarctica  

NASA Astrophysics Data System (ADS)

We present a tectonic interpretation of the breakup and early seafloor spreading between India and Antarctica based on improved coverage of potential field and seismic data off the east Antarctic margin between the Gunnerus Ridge and the Bruce Rise. We have identified a series of ENE trending Mesozoic magnetic anomalies from chron M9o (~130.2 Ma) to M2o (~124.1 Ma) in the Enderby Basin, and M9o to M4o (~126.7 Ma) in the Princess Elizabeth Trough and Davis Sea Basin, indicating that India-Antarctica and India-Australia breakups were roughly contemporaneous. We present evidence for an abandoned spreading centre south of the Elan Bank microcontinent; the estimated timing of its extinction corresponds to the early surface expression of the Kerguelen Plume at the Southern Kerguelen Plateau around 120 Ma. We observe an increase in spreading rate from west to east, between chron M9 and M4 (38-54 mm yr-1), along the Antarctic margin and suggest the tectono-magmatic segmentation of oceanic crust has been influenced by inherited crustal structure, the kinematics of Gondwanaland breakup and the proximity to the Kerguelen hotspot. A high-amplitude, E-W oriented magnetic lineation named the Mac Robertson Coast Anomaly (MCA), coinciding with a landwards step-down in basement observed in seismic reflection data, is tentatively interpreted as the boundary between continental/transitional zone and oceanic crust. The exposure of lower crustal rocks along the coast suggests that this margin formed in a metamorphic core complex extension mode with a high strength ratio between upper and lower crust, which typically occurs above anomalously hot mantle. Together with the existence of the MCA zone this observation suggests that a mantle temperature anomaly predated the early surface outpouring/steady state magmatic production of the Kerguelen LIP. An alternative model suggests that the northward ridge jump was limited to the Elan Bank region, whereas seafloor spreading continued in the West Enderby Basin and its Sri Lankan conjugate margin. In this case, the MCA magnetic anomaly could be interpreted as the southern arm of a ridge propagator that stopped around 120 Ma.

Gaina, Carmen; Müller, R. Dietmar; Brown, Belinda; Ishihara, Takemi; Ivanov, Sergey

2007-07-01

353

Radiological concerns in operation of intense low-energy deuteron beams.  

PubMed

A 40-keV, 5-mA DC deuteron beam was operated at the SARAF with the purpose of characterizing the ion source and the low-energy beam transport system. We used this opportunity to address radiological concern of operating an intense deuteron beam. Fast and thermal neutrons produced via the D(d,n) reaction were measured in the vicinity of the components intercepting the beam using various methods. We found that the neutron yield from implantation of a deuteron beam in a graphite matrix is of the order of 2 x 10(6) n s(-1) mA(-1) into 4pi. PMID:19001902

Weissman, Leo; Berkovits, Dan; Grof, Yair; Ben-Dov, Yair

2008-12-01

354

Comment on the A dependence of quasielastic deuteron knockout from nuclei  

SciTech Connect

The A dependence recently measured in an experiment of our group in full kinematics for quasielastic deuteron knockout by pions revealed that the effective number of quasideuterons in a nucleus is independent of its atomic number. This result differs strongly from the A dependence measured in experiments that studied quasielastic inclusive deuteron knockout by protons, in which case one observes an A{sup 0.33} power-law dependence. Calculations performed on the basis of a simple deuteron-knockout model show that stronger absorptive effects in measurements under conditions of full kinematics may indeed lead to this change in the A dependence.

Abramov, B. M.; Borodin, Yu. A.; Bulychjov, S. A.; Dukhovskoi, I. A.; Krutenkova, A. P.; Kulikov, V. V., E-mail: kulikov@itep.ru; Martemianov, M. A.; Matsuk, M. A.; Turdakina, E. N. [Institute of Theoretical and Experimental Physics (Russian Federation)

2008-12-15

355

Himalayan ironstones, "superplumes," and the breakup of Gondwana  

NASA Astrophysics Data System (ADS)

Oolitic ironstones or glauco-phosphorites were deposited all along the northern India continental margin during major tectonically enhanced transgressions in Frasnian, Permian, Norian, Callovian, Early Cretaceous, and Paleocene time. These regional events of starvation and drowning were commonly associated with alkalic to tholeiitic magmatism and invariably coincided in time with multiple rifting events that punctuated the progressive disintegration of Gondwana. Deposition of major condensed horizons enriched in iron, silica, and phosphorus was fostered by global factors such as eustatic rise, warm "greenhouse" climates, sluggish circulation, increased fertility, and poor ventilation in the oceans. Such anomalous sedimentary conditions recurred synchronously during magnetic quiet zones, pointing to successive episodes of global fast spreading and accelerated terrestrial heat loss. Multiple "pulsations" of Earth are inferred to have triggered supercontinent breakup and widespread volcanism, thus altering the atmosphere and hydrosphere, and dramatically affecting sedimentary and biological systems.

Garzanti, Eduardo

1993-02-01

356

Effect of rf structure on cumulative beam breakup  

SciTech Connect

We treat the effect of rf structure of a linac beam on cumulative beam breakup in the presence of external focusing. Starting with the difference equations of Helm and Loew, we derive two forms of an exact analytic solution for coasting beams: as a sum of products of Gegenbauer polynomials involving external focusing and rf structure, and as an integral involving these same parameters. The continuous-beam limit of Neil, Hall, and Cooper is obtained as the bunch separation goes to zero. An explicit solution is presented for the steady state, including modulation of the incoming displacement, showing both stable and unstable behavior with distance. Asymptotic amplitude expressions are derived for the transient solution, which can lead to even larger beam displacements. Approximate solutions also are obtained for accelerated and decelerated beams. Comparison with numerical simulations are presented.

Gluckstern, R.L.; Cooper, R.K.; Channell, P.J.

1983-01-01

357

Dynamics of water droplets breakup in electric fields  

SciTech Connect

In this paper the authors present an experimental and analytical study of the deformations and breakup of large water droplets that are approximately 1.4 cm in diameter, generated in microgravity, and subjected to an electric field. The deformations were recorded on films taken with a high-speed camera. The films show that under the electric field forces, the droplet extends along the direction of the electric field, forms Taylor cones at the elongated ends, and starts to eject several very small droplets form the tips of the cones before the entire mass breaks up in two or three droplets. The mathematical analysis and computer simulation presented in the paper show a successful reproduction of the various stages of the deformation process in time up to the formation of the Taylor cones.

Inculet, I.I. (Electrical Engineering Dept., Univ. of Western Ontario, London N6A 5B9 (Canada)); Floryan, J.M. (Mechanical Engineering Dept., Univ. of Western Ontario, London N6A 5B9 (Canada)); Haywood, R.J. (Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering)

1992-10-01

358

Obstructed Breakup of Slender Drops in a Microfluidic T Junction  

NASA Astrophysics Data System (ADS)

In this Letter we present a theoretical analysis of the droplet breakup with “permanent obstruction” in a microfluidic T junction [M.-C. Jullien et al., Phys. FluidsPHFLE61070-6631 21, 072001 (2009)10.1063/1.3170983]. The proposed theory is based on a simple geometric construction for the interface shape combined with Tanner’s law for the local contact angle. The resulting scaling of the droplet deformation with time and capillary number is in excellent agreement with the results of direct numerical simulations and prior experiments. More rigorous analysis based on the lubrication approximation reveals a self-similar behavior analogous to the classical problem of a droplet spreading over a preexisting liquid film.

Leshansky, A. M.; Afkhami, S.; Jullien, M.-C.; Tabeling, P.

2012-06-01

359

Neutrino breakup of A=3 nuclei in supernovae  

SciTech Connect

We extend the virial equation of state to include {sup 3}H and {sup 3}He nuclei, and predict significant mass-three fractions near the neutrinosphere in supernovae. While alpha particles are often more abundant, we demonstrate that energy transfer cross sections for muon and tau neutrinos at low densities are dominated by breakup of the loosely-bound {sup 3}H and {sup 3}He nuclei. The virial coefficients involving A=3 nuclei are calculated directly from the corresponding nucleon-{sup 3}H and nucleon-{sup 3}He scattering phase shifts. For the neutral-current inelastic cross sections and the energy transfer cross sections, we perform ab initio calculations based on microscopic two- and three-nucleon interactions and meson-exchange currents.

O'Connor, E. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Department of Physics, UPEI, 550 University Ave, Charlottetown, Prince Edward Island, C1A 4P3 (Canada); Gazit, D.; Barnea, N. [Racah Institute of Physics, Hebrew University, 91904 Jerusalem (Israel); Horowitz, C. J. [Nuclear Theory Center and Department of Physics, Indiana University, Bloomington, Indiana 47408 (United States); Schwenk, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada)

2007-05-15

360

Breakup of molten aluminum jets injected into water  

SciTech Connect

A series of eighteen tests were performed to investigate the behavior of a molten jet of aluminum as it penetrates a deep pool of subcooled water. Jet penetration lengths required for breakup were found to agree with an existing model. Debris size and density were measured and are presented as a function of the jet diameter and water pool temperature. For those tests that exhibited the ability to spread across the steel baseplate under the water, the melt spreading behavior is compared to the existing melt spreading correlation. In the jet mode of melt-water contact, no explosive interactions were observed in these tests. Due to the nearly prototypical nature of these tests, it appears reasonable to conclude that gamma heating of non-fuel components during the DEGB-LOCA would, at worst, benignly melt some aluminum components in the reactor tank, resulting in large particles or debris formations which would remain in the tank and be coolable.

Greene, G.A.; Finfrock, C.C.; Schwarz, C.E. [Brookhaven National Lab., Upton, NY (United States); Hyder, M.L. [Westinghouse Savannah River Co., Aiken, SC (United States)

1992-01-01

361

AKR breakup and auroral particle acceleration at substorm onset  

NASA Astrophysics Data System (ADS)

The dynamical behavior of auroral kilometric radiation (AKR) is investigated in connection with auroral particle acceleration at substorm onsets using high-time-resolution wave spectrograms provided by Polar/PWI electric field observations. AKR develops explosively at altitudes above a preexisting low-altitude AKR source at substorm onsets. This "AKR breakup" suggests an abrupt formation of a new field-aligned acceleration region above the preexisting acceleration region. The formation of the new acceleration region is completed in a very short time (amplitude increases 10,000 times in 30 seconds), suggesting that the explosive development is confined to a localized region. AKR breakups are usually preceded (1-3 minutes) by the appearance and/or gradual enhancement of the low-altitude AKR. This means that the explosive formation of the high-altitude electric field takes place in the course of the growing low-altitude acceleration. The development of the low-altitude acceleration region is thus a necessary condition for the ignition of the high-altitude bursty acceleration. The dH/dt component from a search-coil magnetometer at ground shows that a few minutes prior to substorm onsets, the quasi-DC component begins a negative excursion that is nearly synchronized with the start of the gradual enhancement of the low-altitude AKR, indicating a precursor-like behavior for the substorm. This negative variation of dH/dt suggests an exponentially increasing ionospheric current induced by the upward field-aligned current. At substorm onsets, the decrease in the quasi-DC variation of dH/dt further accelerates, indicating a sudden reinforcement of the field-aligned current.

Morioka, A.; Miyoshi, Y.; Tsuchiya, F.; Misawa, H.; Yumoto, K.; Parks, G. K.; Anderson, R. R.; Menietti, J. D.; Donovan, E. F.; Honary, F.; Spanswick, E.

2008-09-01

362

Intracratonic basin subsidence: a legacy of continental break-up?  

NASA Astrophysics Data System (ADS)

Intracratonic basins are enigmatic, large, and very long-lived sedimentary basins that exits across all the continental landmasses. After formation the subsidence history continues for hundreds of millions of years, providing a potential archive of change in climate and mantle dynamics. Subsidence within these basins initiates during periods of break-up and dispersal of super-continental assemblies. The long-lived subsidence history then contains episodic periods of uplift and subsidence at intervals of 20 to 50 Myr. We propose that intracontinental basins are formed by extension of the lithosphere, related to continental break-up. The subsequent episodic subsidence is driven by the lateral density contrast at the transition from oceanic to continental lithosphere at the passive margin. Continental lithosphere is melt depleted, buoyant and thick. It will resist convective breakdown into the asthenosphere below, but will be prone to lateral flow due to horizontal density contrasts. Changes in lithosphere thickness at the transition between continent and ocean will nucleate convection cells. Using a numerical model of viscous upper mantle flow we show that stability or instability of the continental lithosphere at a passive margin is a function of the lithospheric rheology and composition. In model simulations, a continental lithosphere thought typical of the Phanerozoic continental platform experiences a topographic fluctuations due to an evolving array of convection cells in the mantle. The timing and magnitude of predicted changes in topography are similar to those observed at the eastern North American margin and the Congo Basin in Africa. The open question is if these small-scale instabilities will eventually lead to the onset of subduction and the destruction of the margin.

Armitage, John; Lucazeau, Francis; Jaupart, Claude

2013-04-01

363

Correlating early evolution of parasitic platyhelminths to Gondwana breakup.  

PubMed

Investigating patterns and processes of parasite diversification over ancient geological periods should involve comparisons of host and parasite phylogenies in a biogeographic context. It has been shown previously that the geographical distribution of host-specific parasites of sarcopterygians was guided, from Palaeozoic to Cainozoic times, mostly by evolution and diversification of their freshwater hosts. Here, we propose phylogenies of neobatrachian frogs and their specific parasites (Platyhelminthes, Monogenea) to investigate coevolutionary processes and historical biogeography of polystomes and further discuss all the possible assumptions that may account for the early evolution of these parasites. Phylogenetic analyses of concatenated rRNA nuclear genes (18S and partial 28S) supplemented by cophylogenetic and biogeographic vicariance analyses reveal four main parasite lineages that can be ascribed to centers of diversity, namely Australia, India, Africa, and South America. In addition, the relationships among these biogeographical monophyletic groups, substantiated by molecular dating, reflect sequential origins during the breakup of Gondwana. The Australian polystome lineage may have been isolated during the first stages of the breakup, whereas the Indian lineage would have arisen after the complete separation of western and eastern Gondwanan components. Next, polystomes would have codiverged with hyloid sensu stricto and ranoid frog lineages before the completion of South American and African plate separation. Ultimately, they would have undergone an extensive diversification in South America when their ancestral host families diversified. Therefore, the presence of polystome parasites in specific anuran host clades and in discrete geographic areas reveals the importance of biogeographic vicariance in diversification processes and supports the occurrence and radiation of amphibians over ancient and recent geological periods. PMID:21856629

Badets, Mathieu; Whittington, Ian; Lalubin, Fabrice; Allienne, Jean-Francois; Maspimby, Jean-Luc; Bentz, Sophie; Du Preez, Louis H; Barton, Diane; Hasegawa, Hideo; Tandon, Veena; Imkongwapang, Rangpenyuba; Imkongwapang, Rangpenyubai; Ohler, Annemarie; Combes, Claude; Verneau, Olivier

2011-08-18

364

Fits to data for a stored uncooled polarized deuteron beam  

NASA Astrophysics Data System (ADS)

I perform tracking simulations to fit various measurements of the polarization for a stored uncooled polarized deuteron beam, published in the recent paper by Benati et al. [P. Benati et al., Physical Review Special Topics—Accelerators and Beams 15 (2012) 124202]. The collaboration kindly sent me datafiles of the polarization measurements, and also pertinent details of the experimental data acquisition procedure. The latter are essential to obtain quantitative fits to the data. I describe my findings and inferences from the data. In some cases I offer alternative interpretations of the data from that given by Benati et al. [1]. I also correct some mistakes in my recent paper [S.R. Mane, Nuclear Instruments and Methods in Physics Research Section A 726 (2013) 104–112].

Mane, S. R.

2013-11-01

365

The size of the proton and the deuteron  

NASA Astrophysics Data System (ADS)

We have recently measured the 2S1/2F=1 - 2P3/2F = 2 energy splitting in the muonic hydrogen atom ?p to be 49881.88 (76) GHz. Using recent QED calculations of the fine-, hyperfine, QED and finite size contributions we obtain a root-mean-square proton charge radius of rp = 0.84184 (67) fm. This value is ten times more precise, but 5 standard deviations smaller, than the 2006 CODATA value of rp = 0.8768 (69) fm. The source of this discrepancy is unknown. Using the precise measurements of the 1S-2S transition in regular hydrogen and deuterium and our value of rp we obtain improved values of the Rydberg constant, R? = 10973731.568160 (16) m-1and the rms charge radius of the deuteron rd = 2.12809 (31) fm.

Pohl, Randolf; Amaro, Fernando D.; Antognini, Aldo; Biraben, François; Cardoso, João M. R.; Covita, Daniel S.; Dax, Andreas; Dhawan, Satish; Fernandes, Luis M. P.; Giesen, Adolf; Graf, Thomas; Hänsch, Theodor W.; Indelicato, Paul; Julien, Lucile; Kao, Cheng-Yang; Knowles, Paul; Le Bigot, Eric-Olivier; Liu, Yi-Wei; Lopes, José A. M.; Ludhova, Livia; Monteiro, Cristina M. B.; Mulhauser, Françoise; Nebel, Tobias; Nez, François; Rabinowitz, Paul; dos Santos, Joaquim M. F.; Schaller, Lukas A.; Schuhmann, Karsten; Schwob, Catherine; Taqqu, David; Veloso, João F. C. A.; Kottmann, Franz

2011-01-01

366

Incoherent pion photoproduction on the deuteron including polarization effects  

NASA Astrophysics Data System (ADS)

Incoherent pion photoproduction on the deuteron including polarization effects is studied in the energy region from ?-threshold up to the ?(1232)-resonance with inclusion of all leading ?NN effects. For the elementary pion photoproduction operator, a realistic effective Lagrangian approach is used which displays chiral symmetry, gauge invariance, and crossing symmetry, as well as a consistent treatment of the spin-3/2 interaction. The interactions in the final two-body subsystems are taken in separable form. Effects of final state interaction are investigated and their role in unpolarized and polarization observables are found to be significant. The extracted cross sections and spin asymmetries are compared with available experimental data and predictions of other works, and a satisfactory agreement is obtained. In addition, the sensitivity of results to the elementary N(?, ?)N operator is investigated. Considerable dependence of the d(?, ?)NN results on the elementary amplitude is found. This indicates that it can serve as a filter for different elementary operators.

Darwish, E. M.; Al-Thoyaib, S. S.

2011-03-01

367

Conventional approach to the problem of the deuteron smearing corrections  

SciTech Connect

A comprehensive analysis of the problem of deuteron smearing corrections is given. Some problems of the usual approach (the conventional approach) are discussed. It is shown that the formalism adopted by this approach leads to (i) the existence of the so-called West ..beta.. correction and (ii) the disagreement of the sum rules with the quark parton model expectations in leptonic scattering. It is also shown that in this formalism the electroproduction expression is not inconsistent. Following West for the identification of the wave function, it is found that the smearing correction sigma/sub s/ of the high-energy (50--370 GeV) pion and nucleon process is non-negligible, and hence, in contradiction with the usual expectations. Another test for this approach is suggested.

Kusno, D.; Moravcsik, M.J.

1983-05-01

368

Correcting systematic errors in high-sensitivity deuteron polarization measurements  

NASA Astrophysics Data System (ADS)

This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Jülich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10-5 for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10-6 in a search for an electric dipole moment using a storage ring.

Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F. E.; van der Hoek, D. J.; Imig, A.; Kruithof, W. L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G. A.; Onderwater, C. J. G.; Özben, C. S.; Prasuhn, D.; Levi Sandri, P.; Semertzidis, Y. K.; da Silva E Silva, M.; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, O. O.

2012-02-01

369

Operator evolution via the similarity renormalization group: The deuteron  

SciTech Connect

Similarity renormalization group (SRG) flow equations can be used to unitarily soften nuclear Hamiltonians by decoupling high-energy intermediate-state contributions to low-energy observables while maintaining the natural hierarchy of many-body forces. Analogous flow equations can be used to consistently evolve operators so that observables are unchanged if no approximations are made. The question in practice is whether the advantages of a softer Hamiltonian and less-correlated wave functions might be offset by complications in approximating and applying other operators. Here we examine the properties of SRG-evolved operators, focusing in this article on applications to the deuteron but leading toward methods for few-body systems. We find the advantageous features generally carry over to other operators with additional simplifications in some cases from factorization of the unitary transformation operator.

Anderson, E. R.; Furnstahl, R. J.; Perry, R. J. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Bogner, S. K. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

2010-11-15

370

Electron-deuteron scattering in a relativistic theory of hadrons  

SciTech Connect

The author reviews a three-dimensional formalism that provides a systematic way to include relativistic effects including relativistic kinematics, the effects of negative-energy states, and the boosts of the two-body system in calculations of two-body bound-states. He then explains how to construct a conserved current within this relativistic three-dimensional approach. This general theoretical framework is specifically applied to electron-deuteron scattering both in impulse approximation and when the {rho}{pi}{gamma} meson-exchange current is included. The experimentally-measured quantities A, B, and T{sub 20} are calculated over the kinematic range that is probed in Jefferson Lab experiments. The role of both negative-energy states and meson retardation appears to be small in the region of interest.

Phillips, D.

1998-11-01

371

Energy variable deuteron linac for materials research neutron source  

SciTech Connect

Basic research in new materials and materials technology is a key national resource, and several countries are making plans for advanced capabilities, including intense neutron sources. Advances in high-intensity linear accelerator technology can provide efficient drivers for such sources. Aspects such as energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new opportunities in the experimental program. These considerations are discussed in the context of 20--40 mA continuous-current, 35-MeV compact deuteron linac facility, as a subset of designs with much larger (250 mA) current capability. The possibility for a current-upgradeable facility is briefly described. 11 refs., 2 figs., 1 tab.

Jameson, R.A.

1990-01-01

372

Quasifree compton scattering from the deuteron and nucleon polarizabilities  

PubMed

Cross sections for quasifree Compton scattering from the deuteron were measured for incident energies of E(gamma) = 236-260 MeV at the laboratory angle straight theta(gamma(')) = -135 degrees. The recoil nucleons were detected in a liquid-scintillator array situated at straight theta(N) = 20 degrees. The measured differential cross sections were used, with the calculations of Levchuk et al., to determine the polarizabilities of the bound nucleons. For the bound proton, the extracted values were consistent with the accepted value for the free proton. Combining our results for the bound neutron with those from Rose et al., we obtain 1-sigma constraints of alpha;(n) = 7.6-14.0 and beta;(n) = 1.2-7.6. PMID:10970511

Kolb; Rauf; Igarashi; Hornidge; Pywell; Warkentin; Korkmaz; Feldman; O'Rielly

2000-08-14

373

Neutron Halo Structure at the Limit of Stability Probed by Breakup Reactions  

NASA Astrophysics Data System (ADS)

Atomic nuclei along the neutron drip line are investigated experimentally by breakup reactions of the rare isotope beams. Such exotic nuclei often show the neutron halo structure, which is the main focus of this paper. Characteristic features of the Coulomb and nuclear breakup at intermediate to high incident energies are described. Then, recent experimental results on halo nuclei, mainly on 31Ne, obtained at the new-generation RI-beam facility, RIBF (RI Beam factory) at RIKEN, are presented. Perspectives for the breakup experiments using the new facility SAMURAI at RIBF ara also discussed.

Nakamura, Takashi

2013-08-01

374

Explanation of 3He and triton rates in the alpha breakup inclusive cross sections  

NASA Astrophysics Data System (ADS)

(?, 3He) and (?, t) continuum inclusive spectra are measured on target nuclei ranging from 58Ni to 209Bi. Systematic differences in the absolute magnitudes of the 3He and triton spectra are found. To explain these differences the distorted-wave Born approximation calculations in the post form for inclusive breakup reactions are performed. It is shown that Coulomb effects are responsible for these differences. NUCLEAR REACTIONS (?, t), (?, 3He) breakup reactions: measured d2?d ? dE; targets: 58Ni, 90Zr, 120Sn, 209Bi; post form DWBA breakup theory.

Shyam, R.; Baur, G.; Budzanowski, A.; Bojowald, J.; Dabrowski, H.; Mayer-Böricke, C.; Oelert, W.; Riepe, G.; Rogge, M.; Turek, P.; Rösel, F.; Trautmann, D.

1983-05-01

375

Prediction and suppression of beam breakup instability in multicell superconducting cavities  

NASA Astrophysics Data System (ADS)

Beam breakup instability in superconducting cavities is a serious problem. In this work, a four-cell LEP cavity installed in the KAERI linear accelerator is considered as an example. Dependence of the breakup instability threshold currents on the characteristics of a dipole mode was determined both analytically and numerically. An efficient technique to suppress breakup instability using rf beam focusing within a cavity is suggested. The technique involves applying TE-type monopole higher-order modes and is useful for multicell superconducting cavities with many trapped high-Q dipole modes.

Volkov, V.

2009-01-01

376

Breakup of strongly absorptive projectiles: Application to (h,dp) reaction  

NASA Astrophysics Data System (ADS)

The well known distorted-wave Born-approximation formula for breakup processes was first simplified by introducing several approximations, all of which are believed justified for strongly absorptive high-energy projectiles. This made the theory very transparent and the ensuing numerical calculations rather easy to perform. This new formula, which was applied earlier with success to the breakup of 20Ne, is applied in the present work to that of 3He, again with success. NUCLEAR REACTION Distorted-wave Born approximation; breakup reaction of strongly absorptive projectiles; 51V(3He,dp) reaction, calculated d3?dE d? d? E(3He)=90 MeV.

Udagawa, T.; Tamura, T.

1980-04-01

377

Determination of the Azimuthal Asymmetry of Deuteron Photodisintegration in the Energy Region Egamma = 1.1-2.3 GeV  

NASA Astrophysics Data System (ADS)

Deuteron photodisintegration is a benchmark process for the investigation of the role of quarks and gluons in nuclei. Existing theoretical models of this process describe the available cross sections with the same degree of success. Therefore, spin-dependent observables are crucial for a better understanding of the underlying dynamical mechanisms. However, data on the induced polarization, along with the polarization transfers, have been shown to be insensitive to differences between theoretical models. On the other hand, the beam-spin asymmetry is predicted to have a large sensitivity and is expected to help in identifying the energy at which the transition from the hadronic to the quark-gluon picture of the deuteron takes place. Here, the work done to determine the experimental values of the beam-spin asymmetry in deuteron photodisintegration for photon energies between 1.1--2.3 GeV is presented. The data were taken with the CLAS at the Thomas Jefferson National Accelerator Facility during the g13 experiment. Photons with linear polarization of the order of 80% were produced using the coherent bremsstrahlung facility in Hall B. This work shows that the collected data provide the kinematic coverage and statistics to test the available QCD-based models. The results of this study show that the available theoretical models in their current state do not adequately predict the azimuthal asymmetry in the energy region 1.1--2.3 GeV.

Zachariou, Nicholas

378

Quark-Model Nucleon-Nucleon Interaction Applied to Nucleon-Deuteron Scattering  

NASA Astrophysics Data System (ADS)

We have examined the neutron-deuteron low-energy effective-range parameters, differential cross sections and spin polarization observables of the elastic nucleon-deuteron scattering up to the incident nucleon energy E N = 65 MeV, using the quark-model nucleon-nucleon interaction fss2. These observables are consistently described without introducing three nucleon forces except for the nucleon analyzing power A y ( ?) and the deuteron vector analyzing power iT 11( ?) in the low-energy region E N ? 25 MeV. The long-standing A y puzzle is slightly improved, but still remains. We have incorporated the screened Coulomb force to the proton-deuteron scattering, modifying the Vincent-Phatak approach for the sharp cutoff Coulomb force. The Coulomb effect on the elastic scattering observables is discussed.

Fukukawa, Kenji; Fujiwara, Yoshikazu

2013-03-01

379

Resonating group Faddeev approach to deuteron-alpha scattering  

NASA Astrophysics Data System (ADS)

The resonating group Faddeev method is formulated and applied to d-? elastic and breakup scattering. The effective interaction of the three-cluster resonating group model for the neutron, proton, and ? particle is approximated by the fish bone optical model potential and decomposed into two-body and three-body potentials. The three-body potential is neglected, after being reduced in strength by an off-shell transformation. The two-body potentials are fitted to subsystem on-shell data. Equivalence of subsystem wave functions with resonating group wave functions is checked. Results of the numerical calculation indicate that the three-body observables are sensitive to Pauli effects but are not sensitive to the (unknown) high energy behavior of two-body phase shifts.

Hahn, K.; Schmid, E. W.; Doleschall, P.

1985-02-01

380

Measurements of the Deuteron Elastic Structure Function A(Q{sup 2}) at Jefferson Lab  

SciTech Connect

Measurements of the deuteron elastic structure function A(Q{sup 2}) for 0.7 {le} Q{sup 2} {le} 6.0 (GeV/c){sup 2} are reported. The experiment performed elastic electron-deuteron scattering in coincidence, using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics.

Gerassimos Petratos

1999-06-01

381

Magma-assisted strain migration during the progression from rifting to break-up  

NASA Astrophysics Data System (ADS)

It is important to understand a mechanism of the strain redistribution in order to progress our understanding of sedimentary basin migration and/or continental-ribbon/micro-continent insulation. The change in the lithospheric strength due to thermal relaxation and/or replacement of weaker crust with stronger mantle has usually been considered as a possible mechanism that cases successive deformation to migrate to adjacent regions. This is, however, hardly applicable for an extensional process that can lead to continental break-up. In our previous studies (Yamasaki and Gernigon, Tectonophysics, 468, 169-184, 2009; J. Geol. Soc. Lond., 167, 961-971, 2010), the effect of underplated mafic bodies (UPMB) on the redistribution of extensional strain was examined quantitatively, in which UPMB is emplaced beneath a different region some time after the first rifting process has initiated. It was showed that there possibly exist three different modes of strain redistribution, 1) a shift-completed mode: the strain is completely shifted into a newly weakened region, 2) a transition mode: the strain is redistributed, but lithospheric extension is accommodated by thinning in two regions and 3) a shift-failed mode where the strain is not redistributed. The modes are dependent on the configuration of UPMB and on the initial rheological heterogeneity in the initially deformed region, but it becomes difficult for any UPMB to initiate the redistribution of the deformation once the stretching factor in the first deformed region exceeds a critical value. The general model behaviour can characterise the dynamic process of the strain migration, in terms of which the geological process observed during rifting and break-up is discussed in this study, providing an important implication for a typical rift/margin configuration that the shift-completed or transition mode can be applied for the regions where UPMB has been clearly observed (e.g., the Indian Ocean, the Norwegian-Greenland Sea, the Red Sea/Afar region, the Western Barents Sea and the Brazilian margin).

Yamasaki, Tadashi; Gernigon, Laurent

2013-04-01

382

Li11 Breakup on Pb208 at Energies Around the Coulomb Barrier  

NASA Astrophysics Data System (ADS)

The inclusive breakup for the Li11+Pb208 reaction at energies around the Coulomb barrier has been measured for the first time. A sizable yield of Li9 following the Li11 dissociation has been observed, even at energies well below the Coulomb barrier. Using the first-order semiclassical perturbation theory of Coulomb excitation it is shown that the breakup probability data measured at small angles can be used to extract effective breakup energy as well as the slope of B(E1) distribution close to the threshold. Four-body continuum-discretized coupled-channels calculations, including both nuclear and Coulomb couplings between the target and projectile to all orders, reproduce the measured inclusive breakup cross sections and support the presence of a dipole resonance in the Li11 continuum at low excitation energy.

Fernández-García, J. P.; Cubero, M.; Rodríguez-Gallardo, M.; Acosta, L.; Alcorta, M.; Alvarez, M. A. G.; Borge, M. J. G.; Buchmann, L.; Diget, C. A.; Falou, H. A.; Fulton, B. R.; Fynbo, H. O. U.; Galaviz, D.; Gómez-Camacho, J.; Kanungo, R.; Lay, J. A.; Madurga, M.; Martel, I.; Moro, A. M.; Mukha, I.; Nilsson, T.; Sánchez-Benítez, A. M.; Shotter, A.; Tengblad, O.; Walden, P.

2013-04-01

383

Experimental signatures for distinguishing breakup fusion and transfer in {sup 7}Li+{sup 165}Ho  

SciTech Connect

Reactions involving weakly bound nuclei of {sup 7}Li show large yields of {alpha} particles that have their origin in elastic breakup, breakup followed by fusion, or triton transfer. The latter two processes, breakup fusion and transfer, have similar characteristics and produce the same residual fragments. We report here results of exclusive measurements of charged particles and characteristic {gamma} rays from the heavy residues in the {sup 7}Li+{sup 165}Ho system at 42 MeV (E/V{sub b}{approx_equal}1.6) to look for experimental signatures to differentiate between transfer and breakup fusion. Such a distinction is essential for a better theoretical understanding of both the fusion process and direct reactions involving weakly bound stable and unstable beams.

Tripathi, V.; Navin, A.; Mahata, K.; Ramachandran, K.; Shrivastava, A.; Chatterjee, A.; Kailas, S. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Nanal, V.; Pillay, R.G. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

2005-07-01

384

Breakup of {sup 6}He incident on {sup 209}Bi near the Coulomb barrier  

SciTech Connect

A neutron-{alpha}-particle coincidence experiment was performed to study breakup of {sup 6}He on a {sup 209}Bi target at an incident energy of 22.5 MeV. Direct breakup, as well as breakup through the 2{sup +} excited state of {sup 6}He and also the {sup 5}He+n channel, could be distinguished. A total breakup cross section of 205{+-}65 mb was measured. The data compare well with a coupled-channels calculation that assumes a 50% reduction in the B(E1) computed from a pure {sup 4}He+2n cluster configuration, in agreement with results obtained at much higher energies. A value of B(E2{up_arrow})=5.4{+-}0.7e{sup 2}fm{sup 4} is deduced for the 2{sup +} state in {sup 6}He.

Kolata, J. J.; Spencer, Tabatha [Physics Department, University of Notre Dame, Notre Dame, Indiana 46556-5670 (United States); Amro, H.; Becchetti, F. D. [Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States); Brown, J. A.; Fritsch, A. L.; O'Rourke, P.; Williams, T. [Physics Department, Wabash College, Crawfordsville, Indiana 47933 (United States); DeYoung, P. A.; Hall, C.; Khadka, U.; Mears, Patrick J.; Padilla, D.; Rieth, J. [Department of Physics and Engineering, Hope College, Holland, Michigan 49423-9000 (United States); Hencheck, M. [Physics Department, University of Wisconsin-Green Bay, Green Bay, Wisconsin 54311-7001 (United States); Hinnefeld, J. D. [Physics Department, Indiana University South Bend, South Bend, Indiana 46634-7111 (United States); Peaslee, G. F. [Department of Chemistry, Hope College, Holland, Michigan 49423-9000 (United States)

2007-03-15

385

Faddeev-Yakubovsky Calculation above 4-BODY Break-Up Threshold  

NASA Astrophysics Data System (ADS)

This is the first attempt to solve the four-body Faddeev-Yakubovsky equation at an energy above the 4-body break-up threshold. The calculation is carried out with minimal inputs employing a separable type of the Paris potential, and numerical convergence is checked. About two digits convergence is obtained below the 4-body break-up threshold, however, one or less above that.

Uzu, Eizo; Kamada, Hiroyuki; Koike, Yasuro

2003-04-01

386

Modeling of the break-up of deformable particles in developed turbulent flow  

Microsoft Academic Search

Dynamic behavior of the drops and bubbles in developed turbulent flow depend on turbulent length scale (?), Morton (Mo), Weber (We) and Reynolds (Rea) numbers. In the present work, in order to calculate the maximum stable size of drops and bubbles, the A factor of break-up, Ay (Ay=?a\\/U), that is the ratio of the break-up rate in developed turbulent flow

A. Sarimeseli; G. Kelbaliyev

2004-01-01

387

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry  

Microsoft Academic Search

Using high-speed video, we have studied air bubbles detaching from an\\u000aunderwater nozzle. As a bubble distorts, it forms a thin neck which develops a\\u000asingular shape as it pinches off. As in other singularities, the minimum neck\\u000aradius scales with the time until breakup. However, because the air-water\\u000ainterfacial tension does not drive breakup, even small initial cylindrical\\u000aasymmetries

Nathan C. Keim; Peder Møller; Wendy W. Zhang; Sidney R. Nagel

2006-01-01

388

Binary Subsystem Correlations in Coulomb Breakup Reactions of Two-Neutron Halo Nuclei  

NASA Astrophysics Data System (ADS)

We investigate the three-body Coulomb breakup reactions of two-neutron halo nuclei and discuss the effect of binary subsystem correlations such as of core-n and n-n. We furthermore calculate the invariant mass spectra. It is found that the final-state interactions of core-n and n-n binary subsystems dominantly determine the observed structures of the breakup cross sections, such as the low-lying enhancements.

Kikuchi, Y.

389

Dynamical description of the breakup of one-neutron halo nuclei 11Be and 19C  

Microsoft Academic Search

We investigate the breakup of the one-neutron halo nuclei 11Be and 19C within a dynamical model of the continuum excitation of the projectile. The time evolution of the projectile in coordinate space is described by solving the three-dimensional time dependent Schrödinger equation, treating the projectile-target (both Coulomb and nuclear) interaction as a time dependent external perturbation. The pure Coulomb breakup

S. Typel; R. Shyam

2001-01-01

390

Transverse liquid fuel jet breakup, burning, and ignition. M. S. Thesis  

Microsoft Academic Search

An analytical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion. Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, were used

Hsishang

1990-01-01

391

Curious Fluid Flows: From Complex Fluid Breakup to Helium Wetting  

NASA Astrophysics Data System (ADS)

This work encompasses three projects; pinch-off dynamics in non-Newtonian fluids; helium wetting on alkali metals; and the investigation of quartz tuning forks as cryogenic pressure transducers. Chapter 1 discusses the breakup of a non-Newtonian yield stress fluid bridge. We measured the minimum neck radius, hmin, as a function of time and fit it to a power law with exponent n 1. We then compare n1 to exponent n2, obtained from a rotational rheometer using a Herschel-Bulkley model. We confirm n1=n2 for the widest variety of non-Newtonian fluids to date. When these fluids are diluted with a Newtonian fluid n1 does not equal n2. No current models predict that behavior, identifying a new class of fluid breakup. Chapter 2 presents the first chemical potential-temperature phase diagram of helium on lithium, sodium and gold, using a novel pressure measurement system. The growth and superfluid transition of a helium film on these substrates is measured via an oscillator for isotherms (fixed temperature, varying amount of helium gas), and quenches (fixed amount of helium gas, varying temperature). The chemical potential-temperature plot is similar for gold, lithium and sodium despite the large difference in the substrate binding energies. No signs of a 2-D liquid-vapor transition were seen. Chapter 3 discusses the creation of a 32.768 kHz quartz tuning fork in situ pressure transducer. Tuning forks are used to measure pressure at room temperature, but no work addresses their potential as cryogenic pressure transducers. We mapped out the behavior of a tuning fork as a function of pressure at 298, 7.0, 2.5, 1.6, 1.0 and 0.7 K by measuring the quality factor. The fork is sensitive to pressures above 0.1 mTorr, limiting its use as a pressure gauge at 0.6 K and below. The experimental curves were compared to a theoretical Q(P, T) function that was refined using the 298 K data. At cryogenic temperatures the formula breaks down in the viscous region and becomes inaccurate. The qualitative shape of the theory, but not its quantitative values, matches the data. The discrepancy between the experimental and theoretical Q values appears to be due to unaccounted for dissipation.

Huisman, Fawn Mitsu

392

Source Dynamics from Deuteron and Anti-deuteron Measurements in Au+Au Collisions at sqrt SNN = 200 GeV in PHENIX  

SciTech Connect

The production of deuterons and anti-deuterons in the transverse momentum range 1.1 < p{sub T} < 5.0 GeV/c at mid-rapidity in Au+Au collisions at {radical}S{sub NN} = 200 GeV has been studied by PHENIX for six different centralities. The coalescence of neutrons and protons into deuterons as a function of p{sub T} and N{sub part} has been studied. The large R{sub CP} of deuterons at intermediate p{sub T} is consistent with neutron production having similar centrality dependence to that of protons.

Valle, Hugo [Vanderbilt University; Awes, Terry C [ORNL; Cianciolo, Vince [ORNL; Efremenko, Yuri V [ORNL; Enokizono, Akitomo [Lawrence Livermore National Laboratory (LLNL); Read Jr, Kenneth F [ORNL; Silvermyr, David O [ORNL; Sorensen, Soren P [University of Tennessee, Knoxville (UTK); Stankus, Paul W [ORNL; Young, Glenn R [ORNL; PHENIX, Collaboration [The

2008-01-01

393

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction  

NASA Astrophysics Data System (ADS)

We investigate hard photodisintegration of two nucleons from ^3He nucleus within the framework of hard rescattering model (HRM). In HRM a quark of one nucleon knocked-out by incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with high relative momentum. HRM allows to express the amplitude of two-nucleon break-up reaction through the convolution of photon-quark scattering, NN hard scattering amplitude and nuclear spectral function which can be calculated using nonrelativistic ^3He wave function. HRM predicts several specific features for hard break-up reaction. First, the cross section will approximately scale as s-11. Also one predicts comparable or larger cross section for pp break up as compared to that of pn break-up, which is opposite to what is observed in low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn break-up cross sections. This is due to the fact that same-helicity pp-component is strongly suppressed in the ground state wave function of ^3He. Due to this suppression HRM predicts significantly different asymmetries for the cross section of polarization transfer NN break-up reactions for circularly polarized photons. For the pp break-up this asymmetry is predicted to be zero while for the pn it is close to 23.

Sargsian, Misak; Granados, Carlos

2009-05-01

394

Simulation of slide-coating flows using a fixed grid and a volume-of- fluid front-tracking technique: Startup and bead breakup  

SciTech Connect

Slide coating flow is a workhorse process for manufacturing precision film-coating products. Properly starting up a slide coating process is very important in reducing wastage during startup and ensuring that the process operates within the desired `coating window.` A two-phase flow analysis of slide-coating startup was performed by Palmquist and Scriven (1994) using Galerkin`s method with finite-element basis functions and an elliptic mesh generation scheme. As reported by Chen (1992) from flow visualization experiments, a continuously coated liquid film breaks up into rivulets, which are coating stripes with dry lanes in between, when the coated film becomes thinner and thinner due to either the increase in substrate speed or the reduction in pre-metered feed-liquid pump speed. It was observed that the coated-film breakup process originated from the coating bead, thus the name of bead breakup. Understanding the bead-breakup phenomena and elucidating mechanisms involved will provide guidance for manufacturing thinner coating, an industrial trend for better product performance. In this paper we present simulation results of slide-coating flows obtained from a computational method capable of describing arbitrary, three-dimensional and time-dependent deformations. The method, which is available in a commercial code, uses a fixed grid through which fluid interfaces are tracked by a Volume-of-Fluid technique (Hirt and Nichols, 1981). Surface tension, wall adhesion, and viscous stresses are fully accounted for in our analysis. We illustrate our computational approach by application to startup and the bead-breakup problems. As will be shown, for rapid processes our approach offers the computational efficiency and robustness that are difficult o achieve in conventional finite-element-based methods.

Hirt, C.W. [Flow Science, Inc., Los Alamos, NM (United States); Chen, K.S. [Sandia National Labs., Albuquerque, NM (United States)

1996-03-01

395

Relativistic nuclear corrections to the spin structure function of the deuteron in the light-cone variables  

SciTech Connect

The relativistic deuteron has been considered in the light-cone formalism as a system of two strongly interacting nucleons (two-nucleon approximation). The technique for the calculation of the average helicity of the proton in the deuteron has been considered in the light-cone variables. A receipt has been pro-posed for the consistent calculation of relativistic nuclear corrections to the average helicity of the proton in the deuteron and to the spin structure function of the deuteron g{sub 1}{sup D}. Relativistic-correction-induced change in the Bjorken sum rule has been discussed.

Pavlov, F. F., E-mail: f.pavlov@tuexph.stu.neva.ru [St. Petersburg State Polytechnic University (Russian Federation)

2012-06-15

396

Aerosol cluster impact and break-up : model and implementation.  

SciTech Connect

In this report a model for simulating aerosol cluster impact with rigid walls is presented. The model is based on JKR adhesion theory and is implemented as an enhancement to the granular (DEM) package within the LAMMPS code. The theory behind the model is outlined and preliminary results are shown. Modeling the interactions of small particles is relevant to a number of applications (e.g., soils, powders, colloidal suspensions, etc.). Modeling the behavior of aerosol particles during agglomeration and cluster dynamics upon impact with a wall is of particular interest. In this report we describe preliminary efforts to develop and implement physical models for aerosol particle interactions. Future work will consist of deploying these models to simulate aerosol cluster behavior upon impact with a rigid wall for the purpose of developing relationships for impact speed and probability of stick/bounce/break-up as well as to assess the distribution of cluster sizes if break-up occurs. These relationships will be developed consistent with the need for inputs into system-level codes. Section 2 gives background and details on the physical model as well as implementations issues. Section 3 presents some preliminary results which lead to discussion in Section 4 of future plans.

Lechman, Jeremy B.

2010-10-01

397

Breakup of {sup 12}C resonances into three alpha particles  

SciTech Connect

The reaction {sup 3}He+{sup 11}B->d+{sup 12}C* has been used to populate resonances in {sup 12}C up to an excitation energy of 15 MeV. The subsequent breakup to three alpha particles has been measured in complete kinematics. Dalitz plots are used to visualize and analyze the data. The Dalitz plot intensity distribution exhibits zero points characteristic of the total spin and parity of the 3alpha system allowing us to determine the spin and parity of a state in {sup 12}C at 13.35 MeV whose quantum numbers were hitherto not well established. The Dalitz plot intensity distributions of the 2{sup -} state at 11.83 MeV and the 1{sup +} state at 12.71 MeV are compared with the predictions of a recent three-body calculation as well as with simpler models. All are able to reproduce the gross structures seen in the Dalitz plot, but none give an accurate description of the detailed profile of the distributions.

Kirsebom, O. S.; Fynbo, H. O. U.; Hyldegaard, S.; Riisager, K. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Alcorta, M.; Borge, M. J. G.; Cubero, M.; Dominguez-Reyes, R.; Madurga, M.; Perea, A.; Tengblad, O. [Instituto de Estructura de la Materia, CSIC, ES-28006 Madrid (Spain); Diget, C. A.; Fulton, B. R. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Fraile, L. M. [PH Department, CERN, CH-1211 Geneva 23 (Switzerland); Jonson, B.; Nilsson, T.; Nyman, G. [Fundamental Physics, Chalmers University of Technology, SE-41296 Goeteborg (Sweden); Munoz Martin, A. [CMAM, Universidad Autonoma de Madrid, Cantoblanco, ES-28049 Madrid (Spain)

2010-06-15

398

Initial diversification of living amphibians predated the breakup of Pangaea.  

PubMed

The origin and divergence of the three living orders of amphibians (Anura, Caudata, Gymnophiona) and their main lineages are one of the most hotly debated topics in vertebrate evolution. Here, we present a robust molecular phylogeny based on the nuclear RAG1 gene as well as results from a variety of alternative independent molecular clock calibrations. Our analyses suggest that the origin and early divergence of the three living amphibian orders dates back to the Palaeozoic or early Mesozoic, before the breakup of Pangaea, and soon after the divergence from lobe-finned fishes. The resulting new biogeographic scenario, age estimate, and the inferred rapid divergence of the three lissamphibian orders may account for the lack of fossils that represent plausible ancestors or immediate sister taxa of all three orders and the heretofore paradoxical distribution of some amphibian fossil taxa. Furthermore, the ancient and rapid radiation of the three lissamphibian orders likely explains why branch lengths connecting their early nodes are particularly short, thus rendering phylogenetic inference of implicated relationships especially difficult. PMID:15795855

San Mauro, Diego; Vences, Miguel; Alcobendas, Marina; Zardoya, Rafael; Meyer, Axel

2005-03-17

399

Breakup of evaporating/burning slurry drops by additives  

NASA Astrophysics Data System (ADS)

Single drops of silicon carbide-cumene slurry were suspended from a quartz fiber and ignited. An inert material such as silicon carbide was chosen so that the droplets can be burned until all the fuel is consumed and only the inert residue is left on the quartz fiber. Benzoyl peroxide was added to cumene and the time to disruption of the liquid drop was measured. In the case of benzoyl peroxide, the breaking up of the drop resulting from its thermal decomposition produced CO 2. Both the drop disruption time and the burning of the slurry to dryness were predicted theoretically. Radiation absorption was found to be an important factor in the case of the slurry. Benzoyl peroxide and carbamide peroxide were investigated as additives to a boron slurry to determine if effective drop break-up could be achieved. Both additives produced drop shattering. The carbamide peroxide was particularly effective due to the production of O 2. The green flame associated with boron burning was clearly evident.

Choudhury, P. Roy; Gerstein, M.

400

Cheating, breakup, and divorce: is facebook use to blame?  

PubMed

Abstract The purpose of the present study was to investigate the relationship between using the social networking site known as Facebook and negative interpersonal relationship outcomes. A survey of 205 Facebook users aged 18-82 was conducted using a 16-question online survey to examine whether high levels of Facebook use predicted negative relationship outcomes (breakup/divorce, emotional cheating, and physical cheating). It was hypothesized that those with higher levels of Facebook use would demonstrate more negative relationship outcomes than those with lower use. The study then examined whether these relationships were mediated by Facebook-related conflict. Furthermore, the researchers examined length of relationship as a moderator variable in the aforementioned model. The results indicate that a high level of Facebook usage is associated with negative relationship outcomes, and that these relationships are indeed mediated by Facebook-related conflict. This series of relationships only holds for those who are, or have been, in relatively newer relationships of 3 years or less. The current study adds to the growing body of literature investigating Internet use and relationship outcomes, and may be a precursor to further research investigating whether Facebook use attributes to the divorce rate, emotional cheating, and physical cheating. PMID:23745615

Clayton, Russell B; Nagurney, Alexander; Smith, Jessica R

2013-06-07

401

Capture of comets and the break-up hypothesis  

NASA Astrophysics Data System (ADS)

The input and output osculating heliocentric elements are considered in an ideal model which solves the shock problem for a small body. The model of capture is treated as though it occurs at the vertex of the incoming and outcome orbits, where the orbital plane remains unchanged for a short period close to the time of shock. The analysis permits the application of an instantaneous impulse to the comet's heliocentric velocity vector at the perihelion of a direct parabolic orbit. For comets which have a Tisserand quantity greater than 2 and an inclination of less than 45 degrees, and when the comet's postshock period is similar to that of the planet, the outcome orbit is shown to be direct. The heliocentric motion is shown to be rectilinear when the Tisserand quantity equals 2, and capture can only occur with direct parabolic comets. These and other results of the ideal model of capture are shown to correspond to some observations of Jovian comets, and the break-up of giant comets is suggested by analyzing numerical tests and historical observation data.

Edelman, C.

1991-04-01

402

Dynamical effects in nuclear collisions in the Fermi energy range: aligned breakup of heavy projectiles  

NASA Astrophysics Data System (ADS)

Recent experimental results concerning heavy systems (Pb+Au, Pb+Ag, Pb+Al, Gd+C, Gd+U, Xe+Sn, /...) obtained at GANIL with the INDRA and NAUTILUS /4? arrays will be presented. The study of reaction mechanisms has shown the dominant binary and highly dissipative character of the process. The two heavy and excited fragments produced after the first stage of the interaction can decay into various decay modes from evaporation to multifragmentation including fission. However, deviations from this simple picture have been found by analyzing angular and velocity distributions of light charged particles, and fragments. Indeed, there is a certain amount of matter in excess emitted between the two primary sources suggesting either the existence of a mid-rapidity source similar to the one observed in the relativistic regime (participants) or a strong deformation induced by the dynamics of the collision (neck instability). This last possibility has been suggested by analyzing in detail the angular distributions of the fragments. More precisely, we observe an isotropic component which is compatible with the prediction of statistical models and a second one corresponding to breakup aligned with the recoil direction of the projectile like source which should be compared with the predictions of dynamical calculations based on microscopic transport models.

Bocage, F.; Colin, J.; Louvel, M.; Auger, G.; Bacri, C. O.; Bellaize, N.; Borderie, B.; Bougault, R.; Brou, R.; Buchet, P.; Charvet, J. L.; Chbihi, A.; Cussol, D.; Dayras, R.; De Cesare, N.; Demeyer, A.; Doré, D.; Durand, D.; Frankland, J. D.; Galichet, E.; Genouin-Duhamel, E.; Gerlic, E.; Guinet, D.; Lautesse, P.; Laville, J. L.; Lecolley, J. F.; Legrain, R.; Le Neindre, N.; Lopez, O.; Maskay, A. M.; Nalpas, L.; Nguyen, A. D.; Pârlog, M.; Péter, J.; Plagnol, E.; Rivet, M. F.; Rosato, E.; Saint-Laurent1, F.; Salou, S.; Steckmeyer, J. C.; Stern, M.; T?b?caru, G.; Tamain, B.; Tirel, O.; Tassan-Got, L.; Vient, E.; Vigilante, M.; Volant, C.; Wieleczko, J. P.; Le Brun, C.; Genoux-Lubain2, A.; Rudolf, G.; Stuttgé, L.

2000-08-01

403

Effects of Breakup of Weakly Bound Projectile and Neutron Transfer on Fusion Reactions  

SciTech Connect

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

Lin, C. J.; Zhang, H. Q.; Yang, F.; Ruan, M.; Liu, Z. H.; Wu, X. K.; Zhou, P.; Zhang, C. L.; Zhang, G. L.; An, G. P.; Jia, H. M.; Xu, X. X. [China Institute of Atomic Energy, P.O. Box 275 (10), Beijing 102413 (China)

2006-11-02

404

Variability of the fluvial thermal process during ice breakups of the Lena river (Siberia)  

NASA Astrophysics Data System (ADS)

A 4-years observation program was initiated to quantify the variability of the fluvial thermal erosion during the ice breakups of the Lena River in Central Siberia. Parameters affecting fluvial thermal erosion have been collected in the middle valley near Yakutsk city where active fluvial thermal erosion on frozen islands has been recorded. The heads of islands undergo strong erosion with mean values of 12 m per year and maximal values reaching 40 m. The careful analysis of the annual data shows a high variability of the erosion rate, mostly due to the variability of the water stream temperature and to the duration and timing of the flood season. A laboratory simulation was proposed to quantify the potential impact of the recent global warming, by means of an increase of the water stream temperature. A hydraulic channel in a cold chamber simulate the ground thawing produced by heat transfer from the flow of water through the frozen ground; followed by mechanical transport of the thawed sediments. The measured increase up to 2°C of the water stream temperature could alone multiply the erosion rate by 16% and explains the acceleration of the mobility of fluvial islands on the Lena river.

Costard, Francois; Gautier, Emmanuele; Fedorov, Alexander; Konstantinov, Pacha; Dupeyrat, Laure

2013-04-01

405

Predominance of transfer in triggering breakup in sub-barrier reactions of 6,7Li with 144Sm, 207,208Pb, and 209Bi  

NASA Astrophysics Data System (ADS)

Coincidence measurements of breakup fragments were carried out for the 7Li+144Sm and 6,7Li+207,208Pb,209Bi reactions at sub-barrier energies. Breakup modes in reactions of 6,7Li were identified through the reaction Q values, and the time-scales of each process inferred through the relative energy of the breakup fragments. Breakup was found to be predominantly triggered by nucleon transfer, with p pickup leading to ?+? coincidences being the preferred breakup mode for 7Li, and n stripping leading to ?+p for 6Li. Breakup triggered by 2n stripping was also found to be prominent in the 7Li+144Sm reaction. The breakup yields were separated into prompt and delayed components based on the relative energies of the breakup fragments. This enables the identification of breakup process important in the suppression of complete fusion of 6,7Li at above-barrier energies.

Luong, D. H.; Dasgupta, M.; Hinde, D. J.; du Rietz, R.; Rafiei, R.; Lin, C. J.; Evers, M.; Diaz-Torres, A.

2013-09-01

406

Two-pion exchange currents in photodisintegration of the deuteron  

SciTech Connect

Chiral effective field theory (ChEFT) is a modern framework to analyze the properties of few-nucleon systems at low energies. It is based on the most general effective Lagrangian for pions and nucleons consistent with the chiral symmetry of QCD. For energies below the pion-production threshold it is possible to eliminate the pionic degrees of freedom and derive nuclear potentials and nuclear current operators solely in terms of the nucleonic degrees of freedom. This is very important because, despite a lot of experience gained in the past, the consistency between two-nucleon forces, many-nucleon forces and the corresponding current operators has not been achieved yet. In this presentation we consider the recently derived long-range two-pion exchange (TPE) contributions to the nuclear current operator which appear at next-to leading order of the chiral expansion. These operators do not contain any free parameters. We study their role in the deuteron photodisintegration reaction and compare our predictions with experimental data from Refs [3]. The bound and scattering states are calculated using five different chiral N2LO nucleon-nucleon (NN) potentials which allows to estimate the theoretical uncertainty at a given order in the chiral expansion. For some observables the results are very close to the reference predictions based on the AV18 NN potential and the current operator (partly) consistent with this force.

Rozp edzik, D.; Golak, J. [M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30059 Krakow (Poland); Koelling, S. [Forschungszentrum Juelich, Institut fuer Kernphysik (IKP-3), D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Epelbaum, E. [Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

2011-10-24

407

Incoherent pion photoproduction on the deuteron including polarization effects  

SciTech Connect

Incoherent pion photoproduction on the deuteron including polarization effects is studied in the energy region from {pi}-threshold up to the {Delta}(1232)-resonance with inclusion of all leading {pi}NN effects. For the elementary pion photoproduction operator, a realistic effective Lagrangian approach is used which displays chiral symmetry, gauge invariance, and crossing symmetry, as well as a consistent treatment of the spin-3/2 interaction. The interactions in the final two-body subsystems are taken in separable form. Effects of final state interaction are investigated and their role in unpolarized and polarization observables are found to be significant. The extracted cross sections and spin asymmetries are compared with available experimental data and predictions of other works, and a satisfactory agreement is obtained. In addition, the sensitivity of results to the elementary N({gamma}, {pi})N operator is investigated. Considerable dependence of the d({gamma}, {pi})NN results on the elementary amplitude is found. This indicates that it can serve as a filter for different elementary operators.

Darwish, E.M., E-mail: eeddarwish@yahoo.com [Applied Physics Department, Faculty of Applied Science, Taibah University, P.O. Box 1343, Al-Madinah Al-Munawarah (Saudi Arabia); Physics Department, Faculty of Science, Sohag University, Sohag 82524 (Egypt); Al-Thoyaib, S.S. [Physics Department, Faculty of Science, Qassim University, Buraydah 51452, P.O. Box 6644 (Saudi Arabia)

2011-03-15

408

Radiative corrections to the neutrino-deuteron reactions  

SciTech Connect

The O({alpha}) QED and electroweak radiative corrections to neutrino-deuteron reactions is investigated with particular emphasis given to the constant terms, which have not been treated properly in the literature. This problem is related to the definition of the axial-vector coupling constant g{sub A} as to the inclusion of radiative corrections. After proper calculations of the constants for the Fermi and Gamow-Teller transitions, we find the radiative correction to the neutral current induced reaction, with the usually adopted definition of g{sub A}, is 1.017 for the Higgs boson mass m{sub H}=1.5m{sub Z}. This value is close to that given by Kurylov et al., but this is due to an accidental cancellation of the errors, between those caused by putative identification of constant terms for the Fermi and Gamow-Teller transitions for the charged current reactions and minor errors in their treatment of the constant terms for the neutral current induced reactions.

Fukugita, Masataka; Kubota, Takahiro [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2005-10-01

409

The Use of Satellite Imagery for Monitoring Ice Break-up along the Mackenzie River, N.W.T  

Microsoft Academic Search

The usefulness of satellite imagery for providing comprehensive infor- mation concerning break-up of river ice is discussed. For the years 1975-77, dates of break-up along the Mackenzie River derived from satellite images correlated well with the dates noted at six ground stations in the valley. It is suggested that satellite imagery could also be used to study ice break-up along

B. DEY; H. MOORE; A. F. GREGORY

410

Energy enhancement for deuteron beam fast ignition of a precompressed inertial confinement fusion target  

SciTech Connect

Fast Ignition (FI) is recognized as a potentially promising approach to achieve the high-energy-gain target performance needed for commercial inertial confinement fusion. Here we consider deuteron beam driven FI which provides not only the 'hot spot' ignition spark, but also extra ''bonus'' fusion energy through reactions in the target. In this study, we estimate the impact of the added deposition energy due to the fusion reactions occurring, based on calculations using a modified energy multiplication factor F{sub c}. The deuteron beam energy deposition range and time are also evaluated in order to estimate the desired deuteron initial energy. It is shown that an average of 30% extra energy can be gained from deuterons with 1 MeV initial energy and 12% from deuterons with 3 MeV initial energy. These results indicate that the energy benefit of this approach could be significant, but a much more comprehensive calculation is needed to realize a full 3D design for realistic experimental studies.

Yang Xiaoling; Miley, George H. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Flippo, Kirk A. [P-24 Plasma Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hora, Heinrich [University of New South Wales, Sydney 2052 (Australia)

2011-03-15

411

LSP simulations of fast deuteron generation from CD2 foils by high-intensity laser pulses  

NASA Astrophysics Data System (ADS)

High-energy, high-flux neutron sources have been extensively used in many areas, such as crystallography, radiography, detection of nuclear material and probing of material properties. Previous studies of nuclear reactions through either the D(d,n)^3He or ^7Li(p,n)Be^7 reactions have encountered difficulties in producing neutrons with energies > 10 MeV, required for some of the above applications. A recent novel approach [1,2] that uses the ^7Li(d,n)Be^8 reaction has the advantage of producing energetic neutron beams (>10 MeV) with a short pulse laser produced deuteron beam. In this meeting, we report LSP simulation results on the production of fast deuterons from CD2 foils by high-intensity laser pulses. The properties of the deuteron beam, laser to deuteron conversion efficiency, and impact of hydrocarbon contaminants on the fast deuteron acceleration will be discussed.[4pt] [1] J. Davis et al., Plasma Phys. Control. Fus. 52, 045015 (2010).[0pt] [2] D. P. Higgingson et al., submitted to Phys. Plasmas (2011).

Qiao, Bin; Higginson, D. P.; Stephens, R. B.; Petrov, G.; Wei, M. S.; Beg, F. N.

2011-11-01

412

Energy enhancement for deuteron beam fast ignition of a precompressed inertial confinement fusion target  

NASA Astrophysics Data System (ADS)

Fast Ignition (FI) is recognized as a potentially promising approach to achieve the high-energy-gain target performance needed for commercial inertial confinement fusion. Here we consider deuteron beam driven FI which provides not only the ``hot spot'' ignition spark, but also extra ``bonus'' fusion energy through reactions in the target. In this study, we estimate the impact of the added deposition energy due to the fusion reactions occurring, based on calculations using a modified energy multiplication factor Fc. The deuteron beam energy deposition range and time are also evaluated in order to estimate the desired deuteron initial energy. It is shown that an average of 30% extra energy can be gained from deuterons with 1 MeV initial energy and 12% from deuterons with 3 MeV initial energy. These results indicate that the energy benefit of this approach could be significant, but a much more comprehensive calculation is needed to realize a full 3D design for realistic experimental studies.

Yang, Xiaoling; Miley, George H.; Flippo, Kirk A.; Hora, Heinrich

2011-03-01

413

Deuteron formation in expanding nuclear matter from a strong coupling BCS approach  

SciTech Connect

The process of deuteron formation in intermediate heavy ion reactions is approached within the strong coupling BCS theory assuming that the final stage of the reaction can be described as an adiabatic expansion of a piece of nuclear matter. Since the gap equation in the {sup 3}{ital S}{sub 1}-{sup 3}{ital D}{sub 1} channel goes over into the deuteron Schroedinger equation in the low density limit, a smooth transition from the superfluid Cooper pair phase to a Bose deuteron gas is found. For a fixed entropy ranging from 0.5 to 2 units per particle the deuteron fraction, the chemical potential and temperature are reported as a function of density. For densities down to {rho}=0.1 fm{sup {minus}3} and lower, the deuteron-to-nucleon ratio rapidly increases from a density threshold strongly depending on the entropy. Decreasing further the density this ratio tends logarithmically to one. The possible relevance of these results for heavy ion collisions and the shortcomings of the present approach are briefly discussed.

Baldo, M.; Lombardo, U.; Schuck, P. [INFN, Sezione di Catania, 57 Corso Italia, I-95129 Catania (Italy)]|[Dipartimento di Fisica and INFN, 57 Corso Italia, I-95129 Catania (Italy)]|[CNRS-IN2P3 Universite Joseph Fourier, Institute des Sciences Nucleaires, 53 Av. des Martyrs, F38026 Grenoble Cedex (France)

1995-08-01

414

Deuteron binding energies and form factors from light-front Hamiltonian field theory  

NASA Astrophysics Data System (ADS)

This paper investigates how the breaking of manifest rotational invariance in light-front dynamics affects the binding energy and the form factors of the deuteron. To do this, we derive new light-front nucleon-nucleon one- and two-meson-exchange potentials, and use the potentials to solve for the deuteron wave function and binding energy. We find that including two-meson-exchange (TME) potentials partially repairs the broken rotational invariance of the one-meson-exchange (OME) potential. This is shown by a decrease in the binding energy difference of different m states of the deuteron. We calculate the matrix elements of the electromagnetic current using the deuteron wave functions obtained from the OME and OME+TME potentials. Rotational invariance requires that the matrix elements satisfy an angular condition, but in light-front dynamics that condition is only partially satisfied. The current matrix elements from the OME calculation satisfy the angular condition better than the ones from the OME+TME calculation. The matrix elements of the axial current satisfy the angular condition to the same extent regardless of which wave functions are used for the calculation. Finally, we find that at momentum transfers greater than about 2 GeV2, the breaking of rotational invariance causes less uncertainty in the computed deuteron form factors than do the uncertainties in the nucleon form factors.

Cooke, Jason R.; Miller, Gerald A.

2002-09-01

415

Large Momentum Transfer ed Elastic Scattering and the Structure of the Deuteron  

NASA Astrophysics Data System (ADS)

The deuteron, as the only A = 2 nucleus, is a primary test case for microscopic models of nuclear structure. Elastic electron-deuteron scattering measures the ground-state structure, allowing a test of models to high momentum transfers and short ranges. New high-precision results are available from two Jefferson Laboratory experiments, made possible by the combination of a high-intensity continuous electron beam and high-power cryotargets. The Hall A collaboration has measured the deuteron A structure function to a four-momentum transfer of 6 (GeV/c)^2, and has reduced uncertainties in the B structure function at lower momentum transfer. The t_20 collaboration used the deuteron polarimeter POLDER to extend polarization measurements to a four-momentum transfer of nearly 2 (GeV/c)^2, allowing the charge, magnetic, and quadrupole form factors to be extracted. At the larger momentum transfers, corresponding to shorter internucleonic distances, one may look for a breakdown in the standard nonrelativistic and relativistic meson-baryon models, and perhaps the applicability of QCD-inspired models of the deuteron structure.

Gilman, Ronald

1998-11-01

416

Barrier distribution from {sup 9}Be+{sup 208}Pb quasielastic scattering: Breakup effects in the interaction processes  

SciTech Connect

Excitation function of the quasielastic (QEL) scattering at a backward angle was measured for the weakly bound projectile {sup 9}Be, which bombarded a {sup 208}Pb target at near-barrier energies. Barrier distribution was extracted by means of the first derivative of the experimental cross sections with respect to the effective energies. Theoretical fusion barrier distribution has been calculated with the coupled-channels model and compared with the experimental barrier distribution. By this comparison, it is shown that the experimental barrier distribution extracted from QEL scattering is shifted to low energy by 1.5 MeV as compared with the theoretical one. This energy discrepancy between the theoretical prediction and the experimental data indicates the breakup is an important reaction mechanism in the colliding processes of the weakly bound projectile {sup 9}Be on a spherical target {sup 208}Pb.

Jia, H. M.; Lin, C. J.; Zhang, H. Q.; Liu, Z. H.; Yu, N.; Yang, F.; Jia, F.; Xu, X. X.; Wu, Z. D.; Zhang, S. T.; Bai, C. L. [China Institute of Atomic Energy, P. O. Box 275(10), Beijing 102413 (China)

2010-08-15

417

Breakup of a Transient Wetting Layer in Polymer Blend Thin Films: Unification with 1D Phase Equilibria  

NASA Astrophysics Data System (ADS)

We show that lateral phase separation in polymer blend thin films can proceed via the formation of a transient wetting layer which breaks up to give a laterally segregated film. We show that the growth of lateral inhomogeneities at the walls in turn causes the distortion of the interface in the transient wetting layer. By addressing the 1D phase equilibria of a polymer blend thin film confined between selectively attracting walls, we show that the breakup of a transient wetting layer is due to wall-blend interactions; there are multiple values of the volume fraction at the walls which solve equilibrium boundary conditions. This mechanism of lateral phase separation should be general.

Coveney, Sam; Clarke, Nigel

2013-09-01

418

Beam breakup instability suppression in multicell superconducting rf guns  

NASA Astrophysics Data System (ADS)

In this paper, we provide an analytical description for transverse coupling impedances with dipole high order modes (HOMs) and beam breakup (BBU) instability suppression of relativistic, high-current beams undergoing strong acceleration, such as those typically produced by rf photoinjectors. The model adopted is based on the accepted theory of coupling impedances extended to the case of beams characterized by a fast transition due to strong acceleration, from the nonrelativistic to the relativistic regime in which a bunch trajectory may not be rigidly directed parallel to the axis of the electric field. The trajectory oscillations in a dipole HOM field in the transverse plane are effective in perturbing the bunch energy, which causes an increase of the coupling impedance up to the BBU instability. This BBU instability analysis is based on equations obtained by Volkov [Phys. Rev. ST Accel. Beams 12, 011301 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.011301] in which external focusing due to both the applied transverse electric (TE) HOM and the accelerating fundamental mode as well as dipole HOM damping by external loads are investigated. This analysis is valid in the limit in which the weak nonlinearity of applied fields near the axis may be neglected. The solution suggests a means of enhancing the BBU threshold current. The possibility of obtaining BBU instability suppression in a long, integrated photoinjector and linac structure, such as the superconducting rf source at Forschungs Zentrum Dresden (FZD), are numerically examined. New designs of photoinjectors that provide BBU instability suppression of all dipole HOMs to enhance the threshold currents are suggested.

Volkov, V.; Knobloch, J.; Matveenko, A.

2011-05-01

419

The breakup of levitating water drops observed with a high speed camera  

NASA Astrophysics Data System (ADS)

A wind tunnel was used to interact water drops and were recorded using a high speed camera. Three distinct collisional breakup types were observed and the drop size spectra from each were analysed for comparison with parameterisations constructed by Low and List (1982a). The spectra predicted by the parameterisations did not accurately correlate with the observed breakup distributions for each breakup type when applied to the relatively larger and similarly-sized drop-pairs of size 4-8 mm, comparable to those sometimes observed in nature. We discuss possible reasons for the discrepancies and suggest potential areas for future investigation. A computer programme was subsequently used to solve the stochastic coalescence and breakup equation using the Low and List breakup parameterisation, and the evolving drop spectra for a range of initial conditions were examined. Initial cloud liquid water content was found to be the most influential parameter, whereas initial drop number was found to have relatively little influence. This may have implications when considering the effect of aerosol on cloud evolution, raindrop formation and resulting drop spectra.

Emersic, C.; Connolly, P. J.

2011-04-01

420

Practical method to identify orbital anomaly as spacecraft breakup in the geostationary region  

NASA Astrophysics Data System (ADS)

Identifying a spacecraft breakup is an essential issue to define the current orbital debris environment. This paper proposes a practical method to identify an orbital anomaly, which appears as a significant discontinuity in the observation data, as a spacecraft breakup. The proposed method is applicable to orbital anomalies in the geostationary region. Long-term orbital evolutions of breakup fragments may conclude that their orbital planes will converge into several corresponding regions in inertial space even if the breakup epoch is not specified. This empirical method combines the aforementioned conclusion with the search strategy developed at Kyushu University, which can identify origins of observed objects as fragments released from a specified spacecraft. This practical method starts with selecting a spacecraft that experienced an orbital anomaly, and formulates a hypothesis to generate fragments from the anomaly. Then, the search strategy is applied to predict the behavior of groups of fragments hypothetically generated. Outcome of this predictive analysis specifies effectively when, where and how we should conduct optical measurements using ground-based telescopes. Objects detected based on the outcome are supposed to be from the anomaly, so that we can confirm the anomaly as a spacecraft breakup to release the detected objects. This paper also demonstrates observation planning for a spacecraft anomaly in the geostationary region.

Hanada, Toshiya; Uetsuhara, Masahiko; Nakaniwa, Yoshitaka

2012-07-01

421

Exclusive Measurements of Breakup Reactions in the {sup 7}Li+{sup 144}Sm System  

SciTech Connect

Breakup reactions induced by a 30 MeV {sup 7}Li beam on a {sup 144}Sm target were measured through the coincident detection of the light particles emitted in the reaction plane. The emphasis of the measurements and data analysis was placed in the complete characterization of the reaction by means of the identification of the breakup products and the experimental extraction of the physically relevant magnitudes. The coincident yield of the emitted light particles was compared with the results of kinematical calculations that were done assuming different distributions for these magnitudes and taking into account the geometric response of the detection system. The results of this comparison indicate in all cases a clear dominance of a process compatible with the breakup of {sup 6}Li through the 3{sup +} resonant state at 2.186 MeV following one-neutron transfer from the projectile to the target, over the breakup of the projectile itself. Relative cross sections as a function of the emission angle of the {sup 6}Li and the in-plane anisotropy of the subsequent emission of breakup products were extracted from the data.

Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A. [Departamento de Fisica-TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Capurro, O. A.; Carnelli, P.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Testoni, J. E. [Departamento de Fisica-TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina); Monteiro, D. S. [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, Gragoata, Niteroi, R.J., 24210-340 (Brazil); Niello, J. O. Fernandez [Departamento de Fisica-TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Universidad Nacional de General San Martin, Ayacucho 2197, 1650 San Martin (Argentina); Marta, H. D. [Instituto de Fisica, Facultad de Ingenieria, CC 30 Montevideo (Uruguay)

2009-03-04

422

Quantum Field Theory, and Screening the Coulomb Potential by Mobile Deuterons for the Low-Energy Nuclear Reaction  

Microsoft Academic Search

The Coulomb potential is screened by high density mobile deuterons more than the electrons in the PdDx deuteride, and the coherent motion of deuteron might play an important role for analysis of the low-energy nuclear reaction in condensed matter. Together with the group theoretical approach used in nuclear physics, the quantum field theory might provide a sound foundation for analysis

Hiroshi Takahashi

2005-01-01

423

Measurement of t_20 in the momentum transfer, Q, range of 4.1 fm-1 to 6.8 fm-1 in elastic electron deuteron scattering  

Microsoft Academic Search

The electromagnetic structure of the deuteron can be studied through the measurement of polarization observables in elastic electron deuteron scattering. New d(e,ed) data were recently acquired in experiment E94018 in Hall C at Jefferson Lab. The recoil deuterons from a 12 cm liquid deuterium target were transported by a QQQD magnetic channel to the POLDER polarimeter where their tensor polarizations

Kenneth Gustafsson

1998-01-01

424

Measurement of Tensor Analyzing Powers in Elastic Electron Deuteron Scattering with BLAST  

NASA Astrophysics Data System (ADS)

A precision measurement of the deuteron tensor analyzing powers T20 and T21 in elastic electron-deuteron scattering has been carried out at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range of 2.15 to 4.5 fm-1 using a polarised, stored electron beam; the Bates Large Acceptance Spectrometer Toroid (BLAST) detector; and a highly polarized, internal deuterium gas target. The elastic deuteron form factors GC and GQ were extracted with improved precision using the new data; confirming the location of the first node of the charge monopole form factor. The new data provide strong constraints on nuclear models in a momentum transfer range covering the minimum of T20 and the first node of GC.

Kohl, Michael

2007-04-01

425

Dominant deuteron acceleration with a high-intensity laser for isotope production and neutron generation  

NASA Astrophysics Data System (ADS)

Experiments on the interaction of an ultra-short pulse laser with heavy-water, ice-covered copper targets, at an intensity of 2×1019 W/cm2, were performed demonstrating the generation of a ``pure'' deuteron beam with a divergence of 20°, maximum energy of 8 MeV, and a total of 3×1011 deuterons with energy above 1 MeV--equivalent to a conversion efficiency of 1.5% +/- 0.2%. Subsequent experiments on irradiation of a 10B sample with deuterons and neutron generation from d-d reactions in a pitcher-catcher geometry, resulted in the production of ~106 atoms of the positron emitter 11C and a neutron flux of (4+/-1)×105 neutrons/sterad, respectively.

Maksimchuk, A.; Raymond, A.; Yu, F.; Petrov, G. M.; Dollar, F.; Willingale, L.; Zulick, C.; Davis, J.; Krushelnick, K.

2013-05-01

426

Deuteron-induced X-ray emission - The case for simultaneous PIXE, NRA and RBS  

NASA Astrophysics Data System (ADS)

The use of deuterons for simultaneous PIXE, NRA and RBS is proposed. The quality of deuteron-induced K X-ray emission analysis, evaluated in terms of precision (minimum detection and minimum quantitation limits) and accuracy, is quite satisfactory at the minor element level. Deuteron RBS is found to be a useful compromise between proton and alpha-particle RBS for the thicker layers often encountered in art and archaeology. Some general limitations of PIXE are discussed and accelerator-based techniques in which the ion beam does not make contact with the sample are outlined. Present address VLSI Process Research Laboratory, GEC Research Laboratories Hirst Research Centre East Lane Wemblev, Middlesex HA9 7PP, England.

Barfoot, Keith M.

1986-01-01

427

Deuteron energy of 15 MK in ultra-dense deuterium without plasma formation: Temperature of the interior of the Sun  

NASA Astrophysics Data System (ADS)

Deuterons are released with kinetic energy up to 630 eV from ultra-dense deuterium as shown previously, by Coulomb explosions initiated by ns laser pulses at ?1011 Wcm-2. With higher laser intensity at <1014 Wcm-2, the initial kinetic energy now observed by TOF-MS with variable acceleration energy is up to 1100 eV per deuteron. This indicates ejection of one deuteron by Coulomb repulsion from two stationary charges in the material. It proves a full kinetic energy release of 1260 eV or a deuteron temperature of 15 MK, similar to the temperature in the interior of the Sun. Plasma processes are excluded by the sharp TOF peaks observed and by the slow signal variation with laser intensity. Deuterons with even higher energy from multiple charge repulsion are probably detected. D + D fusion processes are expected to exist in the ultra-dense phase without plasma formation.

Andersson, Patrik U.; Holmlid, Leif

2010-06-01

428

[sup 16]O breakup in quasielastic reactions near the Fermi energy  

SciTech Connect

The quasielastic breakup of an [sup 16]O nucleus at 32.5 MeV/nucleon on a [sup 197]Au target has been investigated by measuring the projectilelike fragments in coincidence with the emitted light charged particles. It is found that the breakup proceeds via sequential, two-step processes in which inelastic scattering and one-neutron pickup are the most significant components in the formation of the primary fragment. This is followed by statistical decay of the highly excited primary fragment. A Monte Carlo simulation was used to identify these processes and to deduce differential and total cross sections for the breakup of [sup 16]O into the [alpha]+[sup 12,13]C channels.

Chavez-Lomeli, E.; Dacal, A.; Ortiz, M.E. (Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A. P. 20-364, Del A. Obregon, Mexico D. F. (Mexico)); Gazes, S.B. (Nuclear Structure Research Laboratory, University of Rochester, Rochester, New York 14627 (United States)); Chan, Y.; Stokstad, R.G. (Nuclear Science Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)); Plagnol, E. (Grand Accelerator National d'Ions Lourds (GANIL), 14021 Caen CEDEX (France)); Siwek-Wilczynska, K. (Institute of Experimental Physics, Warsaw University, 00-681 Warsaw (Poland)); Wilczynski, J. (Institute for Nuclear Studies, 05-400 Swierk-Otwock (Poland))

1993-08-01

429

Three-body breakup in dissociative electron attachment to the water molecule  

SciTech Connect

We report the results of {\\em ab initio} calculations on dissociative electron attachment (DEA) to water that demonstrate the importance of including three-body breakup in the dissociation dynamics. While three-body breakup is ubiquitous in the analogous process of dissociative recombination, its importance in low-energy dissociative electron attachment to a polyatomic target has not previously been quantified. Our calculations, along with our earlier studies of DEA into two-body channels, indicate that three-body breakup is a major component of the observed O- cross section. The local complex potential model provides a generally accurate picture of the experimentallyobserved features in this system, reproducing some quantitatively, others qualitatively, and one not at all.

Haxton, Daniel J.; Rescigno, Thomas N.; McCurdy, C. William

2008-08-28

430

Features of auroral breakup obtained using data of ground-based television observations: case study  

NASA Astrophysics Data System (ADS)

The knowledge about the relative timing of events during the substorm expansion phase onset is very important for understanding the physics of substorms. In this work ground-based television (TV) imaging technique was used for observations of the first auroral arc brightening near zenith of TV chamber for the case of an isolated substorm. The method of the TV image filtration was used giving the possibility to analyze motion of sub visual auroral arcs. The analysis of the connection between the first auroral arc brightening and the beginning of magnetic disturbance was carried out. It was shown that luminosity disturbance is absent to the pole of breakup arc before the breakup and there exist a delay time between the brightening and start of intense magnetic fluctuations in the Pi1-Pi2 frequency ranges. The results obtained have been compared with predictions of theories of auroral breakup.

Antonova, E. E.; Kornilov, I. A.; Kornilova, T. A.; Kornilov, O. I.; Stepanova, M. V.

2009-04-01

431

Formation of Long Tails during Breakup of Oil Droplets Mixed with Dispersants in Locally Isotropic Turbulence  

NASA Astrophysics Data System (ADS)

This study investigates experimentally, the effects of adding dispersants on the breakup of crude oil droplets in turbulent flows during oceanic spills. The current measurements are performed in a nearly homogeneous and isotropic turbulence facility, the central portion of which is characterized using 2-D PIV. Sample crude oil from Alaska National Slope is mixed with dispersant COREXIT 9527 and injected into the central portion of the turbulent facility. High speed, in-line digital holographic cinematography is utilized to visualize the breakup of droplets at high spatial and temporal resolution. We observe that, in some cases, after the droplet breaks up, the elongated portion of the droplet does not recoil, leaving an elongated tail, probably due to the low local surface tension. At high dispersant to oil ratios, extremely thin tails extend from the droplet, and are stretched by the flow. Breakup of these thin threads produces very small oil droplets, a desired effect during cleanup of oil spill.

Gopalan, Balaji; Katz, Joseph

2008-11-01

432

Can the Neutron-Neutron Scattering Length be Determined from n-d Breakup Experiments?  

SciTech Connect

Two recent nd breakup experiments are discussed which were aimed at the determination of ann, the neutron-neutron scattering length. In both cases, the data were analyzed by means of state-of-the-art Monte-Carlo simulations based on rigorous three-nucleon calculations with realistic nucleon-nucleon potentials. Yet, the two results differ greatly, whereat one of them agrees with the value obtained via the 2H({pi}-,nn){gamma} reaction, while the second one reproduces the average result of all previous nd breakup experiments. Moreover, some other recent findings regarding the nd breakup process raise the old question anew whether the nn scattering length can be extracted at all from this reaction using present-day theories.

Witsch, W. von [Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, D-53115 Bonn (Germany)

2003-08-26

433

Practical method to identify orbital anomaly as spacecraft breakup in the geostationary region  

NASA Astrophysics Data System (ADS)

Identifying spacecraft breakup events is an essential issue for better understanding of the current orbital debris environment. This paper proposes an observation planning approach to identify an orbital anomaly, which appears as a significant discontinuity in archived orbital history, as a spacecraft breakup. The proposed approach is applicable to orbital anomalies in the geostationary region. The proposed approach selects a spacecraft that experienced an orbital anomaly, and then predicts trajectories of possible fragments of the spacecraft at an observation epoch. This paper theoretically demonstrates that observation planning for the possible fragments can be conducted. To do this, long-term behaviors of the possible fragments are evaluated. It is concluded that intersections of their trajectories will converge into several corresponding regions in the celestial sphere even if the breakup epoch is not specified and it has uncertainty of the order of several weeks.

Uetsuhara, Masahiko; Hanada, Toshiya

2013-09-01

434

Tensor polarization in elastic electron-deuteron scattering to the highest possible momentum transfers  

SciTech Connect

In elastic electron-deuteron scattering, the tensor polarization moments t{sub 20}, t{sub 21} and t{sub 22}, together with the unpolarized cross-sections, have been measured up to a momentum transfer of 1.8 (GeV/c){sup 2}, or 6.8 fm{sup -1}. The experiment was performed at Jefferson Laboratory using the recoil deuteron polarimeter POLDER. Preliminary results are presented and discussed, especially in view of their significance concerning the applicability of perturbative QCD to this exclusive process.

Garcon, M; Ahmidouch, A; Anklin, H; Arvieux, J; Ball, J; Beedoe, S; Beise, E J; Bimbo, L; Boeglin, W; Breuer, H; Carlini, R; Chant, N S; Danagoulian, S; Dow, K; Ducret, J -E; Dunne, J; Ewell, L; Eyraud, L; Furget, C; Gilman, R; Glashausser, C; Gueye, P; Gustafsson, K; Hafidi, K; Honegger, A; Jourdan, J; Kox, S; Kumbartzki, G; Lu, L; Lung, A; Mack, D; Markowitz, P; McIntyre, J; Meekins, D; Merchez, F; Mitchell, J; Mohring, R; Mtingwa, S; Mrktchyan, H; Pitz, D; Qin, L; Ransome, R; Raoul, J -S; Roos, P G; Rutt, P; Schmidt, W; Sawafta, R; Stepanyan, S; Stephenson, R; Tieulent, R; Tomasi-Gustafsson, E

1999-07-01

435

Study By Spin Tracking of A Storage Ring For Deuteron Electric Dipole Moment  

SciTech Connect

Spin tracking of polarized deuterons for a proposed experiment to measure a possible Electric Dipole Moment (EDM) of the deuteron was done by using the codes UAL and SPINK. In the experiment the direction of spin polarization will be frozen using crossed electric and magnetic fields. Systematics, in particular the effects of non-linearities of the lattice on a beam with finite emittance and energy spread, have been extensively simulated and the effect of sextuple corrections to increase the spin coherence time has been studied.

Lin, F.; Malitsky, N. D.; Luccio, A. U.; Morse, W. M.; Semertzidis, Y. K. [Brookhaven National Laboratory, Upton, NY (United States); Onderwater, C. J. G. [University of Groningen, NL-9747AA Groningen (Netherlands); Orlov, Y. F. [Cornell University, Ithaca, NY (United States)

2009-08-04

436

Measurements of the Deuteron Elastic Structure Function A(Q{sup 2}) for 0.7  

SciTech Connect

The deuteron elastic structure function A(Q{sup 2}) has been extracted in the range 0.7 < or = Q{sup 2} < or = 6.0 (GeV/c){sup 2} from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics.

L. C. Alexa; B. D. Anderson; K. A. Aniol; K. Arundell; L. Auerbach; F. T. Baker; J. Berthot; P. Y. Bertin; W. Bertozzi; L. Bimbot; W. U. Boeglin; E. J. Brash; V. Breton; H. Breuer; E. Burtin; J. R. Calarco; L. S. Cardman; C. Cavata; C.-C. Chang; J.-P. Chen; E. Chudakov; E. Cisbani; D. S. Dale; N. Degrande; R. De Leo; A. Deur; N. d'Hose; B. Diederich; J. J. Domingo; M. B. Epstein; L. A. Ewell; J. M. Finn; K. G. Fissum; H. Fonvieille; B. Frois; S. Frullani; H. Gao; J. Gao; F. Garibaldi; A. Gasparian,; S. Gilad; R. Gilman; A. Glamazdin; C. Glashausser; J. Gomez; V. Gorbenko; J.-O. Hansen; R. Holmes; M. Holtrop; C. Howell; G. M. Huber; C. Hyde-Wright; M. Iodice; C. W. de Jager; S. Jaminion; J. Jardillier; M. K. Jones; C. Jutier,; W. Kahl; S. Kato; A. T. Katramatou; J. J. Kelly; S. Kerhoas; A. Ketikyan; M. Khayat; K. Kino; L. H. Kramer; K. S. Kumar; G. Kumbartzki; M. Kuss; G. Lavessiere; A. Leone; J. J. LeRose; M. Liang; R. A. Lindgren; N. Liyanage; G. J. Lolos; R. W. Lourie; R. Madey,; K. Maeda; S. Malov; D. M. Manley; D. J. Margaziotis; P. Markowitz; J. Marroncle; J. Martino; C. J. Martoff; K. McCormick; J. McIntyre; R. L. J. van der Meer; S. Mehrabyan; Z.-E. Meziani; R. Michaels; G. W. Miller; J. Y. Mougey; S. K. Nanda; D. Neyret; E. A. J. M. Offermann; Z. Papandreou; C. F. Perdrisat; R. Perrino; G. G. Petratos; S. Platchkov; R. Pomatsalyuk; D. L. Prout; V. A. Punjabi; T. Pussieux; G. Quemener; R. D. Ransome; O. Ravel; Y. Roblin; D. Rowntree; G. Rutledge; P. M. Rutt; A. Saha; T. Saito; A. J. Sarty; A. Serdarevic,; T. Smith; K. Soldi; P. Sorokin; P. A. Souder; R. Suleiman; J. A. Templon; T. Terasawa; L. Todor; H. Tsubota; H. Ueno; P. E. Ulmer; G. M. Urciuoli; L. Van Hoorebeke; P. Vernin; B. Vlahovic; H. Voskanyan; J. W. Watson; L. B. Weinstein; K. Wijesooriya; R. Wilson; B. B. Wojtsekhowski; D. G. Zainea; W-M. Zhang; J. Zhao; Z.-L. Zhou

1999-02-15

437

Measurement of (anti)deuteron and (anti)proton production in DIS at HERA  

NASA Astrophysics Data System (ADS)

The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300 318 GeV using an integrated luminosity of 120 pb-1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range 0.3

deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements.

ZEUS Collaboration; Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Nuncio-Quiroz, A. E.; Paul, E.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Dossanov, A.; Drugakov, V.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Hüttmann, A.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Notz, D.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Korcsak-Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

2007-12-01

438

Deuteron structure studies from electron scattering from vector and tensor polarized deuterium with BLAST  

NASA Astrophysics Data System (ADS)

The electromagnetic structure of the deuteron is manifest in many polarization observables accessible by electron scattering in elastic, quasielastic, and pion production kinematics which have been measured simultaneously with the BLAST experiment at MIT-Bates. The deuteron's quadrupole moment and associated nonspherical shape give rise to elastic tensor analyzing powers and vector correlation parameters. Electrodisintegration in the quasielastic regime allows for a systematic study of final state interaction, meson exchange and relativistic effects. Pion electroproduction from tensor-polarized deuterium is well suited to probe effects due to the two-nucleon singlet-S state. This talk will discuss the current status of the data analysis and present preliminary results.

Kohl, Michael

2007-10-01

439

Test of the Glauber formula for nucleon-deuteron scattering at intermediate energies  

SciTech Connect

A high-precision test of the Glauber formula for the amplitude of nucleon-deuteron scattering is performed. Nucleon-nucleon amplitudes used in the calculations depend on the spins of interacting particles, phase shifts, and mixing parameters. These amplitudes were derived by using the Njim I, Njim II, Njim 93, and Reid 93 realistic potentials. The differential cross sections for nucleon-deuteron scattering were calculated for the projectile-nucleon energies of 65, 95, 135, 150, 190, and 250 MeV, and the results of these calculations were compared with experimental data.

Kovalchuk, V. I., E-mail: sabkiev@gmail.com [Taras Shevchenko National University of Kyiv (Ukraine)

2012-01-15

440