Sample records for deuteron breakup mechanism

  1. Deuteron breakup mechanism in the intermediate-energy region

    SciTech Connect

    Divadeenam, M.; Ward, T.E.

    1991-01-01

    In an earlier investigation, we have explored the possibility of explaining the deuteron breakup mechanism in terms of the Udagawa and Tannura (UT) formalism of the breakup-fusion process. The experimental doubly differential data were very well reproduced for the test case studies. However, the application of UT formalism of the spirit of DWBA involves the use of optical-model parameters for different nuclei and at different energies. The optical model parameters are not always unique. In the present study we investigate the deuteron breakup mechanism in terms of the semiclassical models of Serber (for the nuclear interaction part) and Dancoff (for the electromagnetic dissociation). In the case of Serber model the modification due to the finite range of the deuteron and the Glauber correction for the diffractive disassociation are considered. The modified deuteron breakup cross section either for the (d,p) or the (d,n) process is proportional to the product of the target radius and the deuteron radius (R{sub target} {center dot} R{sub deuteron}). The predicted proton/neutron spectrum is centered around 1/2 E{sub d} and forward peaked. The Coulomb dissociation of deuteron is attributed to the deuteron dipole excitation in the presence of the nuclear Coulomb field. The neutron/proton spectrum, resulting from the Coulomb breakup of the deuteron, is highly forward peaked and also centered around 1/2 E{sub d}. The systematics of the deuteron breakup neutron/proton spectra are investigated for medium to heavy target nuclei at 50--200 MeV deuteron energies. 10 refs., 4 figs.

  2. Neutron-deuteron breakup and quasielastic scattering

    E-print Network

    Ohlson, Alice Elisabeth

    2009-01-01

    Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The ...

  3. Investigation of the intermediate-energy deuteron breakup reaction

    SciTech Connect

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

    1989-01-01

    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.

  4. Deuteron-proton breakup at medium energies

    NASA Astrophysics Data System (ADS)

    Kistryn, St.; Stephan, E.

    2013-06-01

    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.

  5. The Kohn Variational Principle for Elastic Proton--Deuteron Scattering above Deuteron Breakup Threshold

    E-print Network

    M. Viviani; A. Kievsky; S. Rosati

    2001-02-21

    The Kohn variational principle is formulated for calculating elastic proton-deuteron scattering amplitudes at energies above the deuteron breakup threshold. The use of such a principle with an expansion of the wave function on the (correlated) hyperspherical harmonic basis is discussed.

  6. Hard breakup of the deuteron into two ? isobars

    NASA Astrophysics Data System (ADS)

    Granados, Carlos G.; Sargsian, Misak M.

    2011-05-01

    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.

  7. Hard breakup of the deuteron into two ? -isobars

    NASA Astrophysics Data System (ADS)

    Granados, Carlos; Sargsian, Misak

    2011-04-01

    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 ?++?- 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 initial ?? components of the deuteron wave function. In this case, the angular distributions and cross sections of the breakup in both ?++?- and ?+?0 channels are expected to be similar. This work was supported by U.S. Department of Energy Grant under contract DE-FG02-01ER41172, and by the FIU DEA program.

  8. Hard breakup of the deuteron into two {Delta} isobars

    SciTech Connect

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

    2011-05-15

    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.

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

    SciTech Connect

    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

    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.

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

    Microsoft Academic Search

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

    2007-01-01

    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.

  11. Vector and Tensor Polarization Measurements for Deuteron-Proton and Deuteron-Neutron Quasifree Scattering Using the Polarized Deuteron + Deuteron Going to Deuteron + Proton + Neutron Breakup Reaction at 12 Mev

    NASA Astrophysics Data System (ADS)

    Felsher, Paul Daniel

    1991-02-01

    Measurements of vector and tensor analyzing powers A_{y}, A_ {yy} and A_{zz} for dp and dn quasifree scattering (QFS) have been made using the vec d+dto d+p+n breakup reaction at the Triangle Universities Nuclear Laboratory. The experiment was conducted with a 12-MeV tensor-polarized deuteron beam incident on a gas cell filled with one bar deuterium. The momenta of two (deuteron-neutron, deuteron -proton or proton-neutron) of the three outgoing particles were measured simultaneously, thereby completely defining the reaction kinematics. Deuteron-proton coincidence data were taken at five laboratory angle pairs: (theta _{d},theta_{p}) = (+/-10.0^circ, mp10.0^circ), (+/-10.0, mp41.2 ^circ), (+/-17.0 ^circ,mp17.0 ^circ), (+/-17.0 ^circ,mp34.5 ^circ) and (+/-19.4 ^circ,mp19.4 ^circ). Deuteron-neutron and proton -neutron coincidence data were taken at three laboratory angle pairs: (theta_{d}, theta_{n}) = (theta _{n},theta_{n}) = (+/-17.0^ circ,mp17.0^circ ), (+/-17.0^ circ,mp34.5^circ ) and (+/-19.4^ circ,mp28.9^circ ). The angle pairs (theta_ {d},theta_{n}), (theta_{p},theta_ {n}) and (theta_ {d},theta_{p}) were chosen such that the reaction would be well-suited for observing dn and dp QFS. Deuteron-proton coincidence data were sorted into two-dimensional (2D) spectra of deuteron energy versus proton energy, while proton-neutron and deuteron -neutron data were sorted into 2D spectra of neutron time -of-flight versus proton energy and deuteron energy, respectively. Each 2D spectrum was projected onto the kinematically allowed locus. Analyzing powers were computed as a function of arc length S along the locus for A_{y }, A_{yy} and A_{zz}. Since four-nucleon calculations involving polarization observables for the vec d+dto d+p+n breakup reaction are not yet available, the data are compared to Impulse-Approximation (IA) calculations. The IA calculations included off-the-energy-shell deuteron -nucleon (dN) amplitudes as well as on-the-energy-shell dN amplitudes and also included the coherent addition of scattering amplitudes for both target breakup and projectile breakup. The IA calculations fail to reproduce many of the details in the measured data, indicating that the vec d+dto d+p+n breakup process is inherently more complicated at 12 MeV than the single scattering assumption which forms the basis for the IA. The possibility of using the vec d+dto d+p+n breakup reaction to examine charge symmetry breaking in the nucleon-nucleon interaction is also explored. Some differences in the analyzing powers for charge symmetric processes were observed. Detailed examination of the breakup process suggests that while some of the differences can be attributed to electromagnetic effects, other differences cannot. These unexplained differences could be a signature of charge-symmetry breaking. The development of a computer code to conduct four-nucleon calculations using a realistic microscopic approach for the vec d+dto d+p+n reaction has recently been initiated by A. C. Fonseca of Lisbon. The forthcoming calculations will form the basis for interpreting the present data and stimulating further studies of nucleon-nucleon interactions through this breakup process.

  12. Vector and tensor analysing powers in deuteron-proton breakup reactions at intermediate energies

    E-print Network

    D. Chiladze; J. Carbonell; S. Dymov; V. Glagolev; M. Hartmann; V. Hejny; A. Kacharava; I. Keshelashvili; A. Khoukaz; H. R. Koch; V. Komarov; P. Kulessa; A. Kulikov; G. Macharashvili; Y. Maeda; T. Mersmann; S. Merzliakov; S. Mikirtytchiants; A. Mussgiller; M. Nioradze; H. Ohm; F. Rathmann; R. Schleichert; H. J. Stein; H. Stroeher; Yu. Uzikov; S. Yaschenko; C. Wilkin

    2006-03-15

    Vector and tensor analysing powers of the d(pol)p->(pp)n (charge-exchange) and d(pol)p->(pn)p (non-charge-exchange) breakup reactions have been measured with the ANKE spectrometer at the COSY ring at a deuteron beam energy of 1170 MeV for small momentum transfers to the low excitation energy (pp) or (pn) systems. A quantitative understanding of the values of A_xx and A_yy for the charge-exchange reaction is provided by impulse approximation calculations. The data suggest that spin-flip isospin-flip transitions, which dominate the charge-exchange breakup of the deuteron, are also important in the non-charge-exchange reaction.

  13. Characterization of a Tunable Quasi-Monoenergetic Neutron Beamfrom Deuteron Breakup

    SciTech Connect

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

    2006-12-14

    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.

  14. Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions

    SciTech Connect

    Konobeevski, E. S., E-mail: konobeev@inr.ru; Zuyev, S. V.; Mordovskoy, M. V.; Potashev, S. I.; Sharapov, I. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2013-11-15

    An analysis of the most recent data on the reaction nd {yields} pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10-60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.

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

    PubMed

    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

    2008-05-01

    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

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

    SciTech Connect

    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

    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.

  17. Electromagnetic deuteron form factors in point form relativistic quantum mechanics

    E-print Network

    N. A. Khokhlov

    2015-03-10

    A study of electromagnetic structure of the deuteron in the framework of relativistic quantum mechanics is presented. The deuteron form factors dependencies on the transferred 4-momentum Q are calculated. We compare results obtained with different realistic deuteron wave functions stemming from Nijmegen-I, Nijmegen-II, JISP16, CD-Bonn, Paris and Moscow (with forbidden states) potentials. A nucleon form factor parametrization consistent with modern experimental analysis was used as an input data.

  18. Analysis of experimental data on doublet neutron-deuteron scattering at energies below the deuteron-breakup threshold on the basis of the pole approximation of the effective-range function

    SciTech Connect

    Babenko, V. A.; Petrov, N. M. [National Academy of Sciences of Ukraine, Bogolyubov Institute for Theoretical Physics (Ukraine)], E-mail: pet@online.com.ua

    2008-01-15

    On the basis of the Bargmann representation of the S matrix, the pole approximation is obtained for the effective-range function k cot {delta}. This approximation is optimal for describing the neutron-deuteron system in the doublet spin state. The values of r{sub 0} = 412.469 fm and v{sub 2} = -35 495.62 fm{sup 3} for the doublet low-energy parameters of neutron-deuteron scattering and the value of D = 172.678 fm{sup 2} for the respective pole parameter are deduced by using experimental results for the triton binding energy E{sub T}, the doublet neutron-deuteron scattering length a{sub 2}, and van Oers-Seagrave phase shifts at energies below the deuteron-breakup threshold. With these parameters, the pole approximation of the effective-range function provides a highly precise description (the relative error does not exceed 1%) of the doublet phase shift for neutron-deuteron scattering at energies below the deuteron-breakup threshold. Physical properties of the triton in the ground (T) and virtual (v) states are calculated. The results are B{sub v} = 0.608 MeV for the virtuallevel position and C{sub T}{sup 2} = 2.866 and C{sub v}{sup 2} = 0.0586 for the dimensionless asymptotic normalization constants. It is shown that, in the Whiting-Fuda approximation, the values of physical quantities characterizing the triton virtual state are determined to a high precision by one parameter, the doublet neutron-deuteron scattering length a{sub 2}. The effective triton radii in the ground ({rho}{sub T} = 1.711 fm) and virtual ({rho}{sub v} = 74.184 fm) states are calculated for the first time.

  19. Theory of neutron-deuteron break-up at 14.4 MeV

    Microsoft Academic Search

    R. T. Cahill; I. H. Sloan

    1971-01-01

    We report numerical calculations of proton spectra for three separable potential models of the three-body break-up reaction n+d --> n+n+p, at a neutron laboratory energy of 14.4 MeV. The first (the YY model) is that used by Aaron and Amado, but with somewhat different results. The second (the YT model) replaces the Yamaguchi form factor for the singlet nucleon-nucleon interaction

  20. Breakup mechanisms in heavy-ion collisions at low energies

    SciTech Connect

    Shvedov, L.; Colonna, M. [Laboratori Nazionali del Sud, INFN, via S. Sofia 62, I-95123 Catania (Italy); Di Toro, M. [Laboratori Nazionali del Sud, INFN, via S. Sofia 62, I-95123 Catania (Italy); Physics and Astronomy Department, University of Catania, Catania (Italy)

    2010-05-15

    We investigate reaction mechanisms occurring in heavy-ion collisions at low energy (approx20 MeV/nucleon). In particular, we focus on the competition between fusion and breakup processes (deep inelastic and fragmentation) in semiperipheral collisions, where the formation of excited systems under various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration, described in terms of shape observables such as quadrupole and octupole moments, we derive fusion and fission probabilities, from which the corresponding fusion and breakup cross sections can finally be evaluated. The dependence of the results on shape, angular momentum, and excitation energy is discussed.

  1. Breakup mechanisms in heavy-ion collisions at low energies

    NASA Astrophysics Data System (ADS)

    Shvedov, L.; Colonna, M.; di Toro, M.

    2010-05-01

    We investigate reaction mechanisms occurring in heavy-ion collisions at low energy (~20 MeV/nucleon). In particular, we focus on the competition between fusion and breakup processes (deep inelastic and fragmentation) in semiperipheral collisions, where the formation of excited systems under various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration, described in terms of shape observables such as quadrupole and octupole moments, we derive fusion and fission probabilities, from which the corresponding fusion and breakup cross sections can finally be evaluated. The dependence of the results on shape, angular momentum, and excitation energy is discussed.

  2. Breakup mechanisms in heavy-ion collisions at low energies

    Microsoft Academic Search

    L. Shvedov; M. Colonna; M. di Toro

    2010-01-01

    We investigate reaction mechanisms occurring in heavy-ion collisions at low energy (~20 MeV\\/nucleon). In particular, we focus on the competition between fusion and breakup processes (deep inelastic and fragmentation) in semiperipheral collisions, where the formation of excited systems under various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration,

  3. Breakup mechanisms in heavy-ion collisions at low energies

    Microsoft Academic Search

    L. Shvedov; M. Colonna; M. Di Toro

    2010-01-01

    We investigate reaction mechanisms occurring in heavy-ion collisions at low energy (approx20 MeV\\/nucleon). In particular, we focus on the competition between fusion and breakup processes (deep inelastic and fragmentation) in semiperipheral collisions, where the formation of excited systems under various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration,

  4. Droplet Breakup Mechanisms in Air-blast Atomizers

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

    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.

  5. Polarization observables in hard rescattering mechanism of deuteron photodisintegration

    NASA Astrophysics Data System (ADS)

    Sargsian, Misak M.

    2004-05-01

    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.

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

    SciTech Connect

    Benjamin J. Crowe III

    2009-09-30

    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.

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

    SciTech Connect

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

    2005-08-11

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

  8. Mechanism of Water Droplet Breakup Near the Leading Edge of an Airfoil

    NASA Technical Reports Server (NTRS)

    Vargas, Mario; Sor, Suthyvann; Magarino, Adelaida, Garcia

    2012-01-01

    This work presents results of an experimental study on droplet deformation and breakup near the leading edge of an airfoil. The experiment was conducted in the rotating rig test cell at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid, Spain. The airfoil model was placed at the end of the rotating arm and a monosize droplet generator produced droplets that fell from above, perpendicular to the path of the airfoil. The interaction between the droplets and the airfoil was captured with high speed imaging and allowed observation of droplet deformation and breakup as the droplet approached the airfoil near the stagnation line. Image processing software was used to measure the position of the droplet centroid, equivalent diameter, perimeter, area, and the major and minor axes of an ellipse superimposed over the deforming droplet. The horizontal and vertical displacement of each droplet against time was also measured, and the velocity, acceleration, Weber number, Bond number, Reynolds number, and the drag coefficients were calculated along the path of the droplet to the beginning of breakup. Droplet deformation is defined and studied against main parameters. The high speed imaging allowed observation of the actual mechanism of breakup and identification of the sequence of configurations from the initiation of the breakup to the disintegration of the droplet. Results and comparisons are presented for droplets of diameters in the range of 500 to 1800 microns, and airfoil velocities of 70 and 90 m/sec.

  9. Multiple mechanisms of spiral wave breakup in a model of cardiac electrical activity

    NASA Astrophysics Data System (ADS)

    Fenton, Flavio H.; Cherry, Elizabeth M.; Hastings, Harold M.; Evans, Steven J.

    2002-09-01

    It has become widely accepted that the most dangerous cardiac arrhythmias are due to reentrant waves, i.e., electrical wave(s) that recirculate repeatedly throughout the tissue at a higher frequency than the waves produced by the heart's natural pacemaker (sinoatrial node). However, the complicated structure of cardiac tissue, as well as the complex ionic currents in the cell, have made it extremely difficult to pinpoint the detailed dynamics of these life-threatening reentrant arrhythmias. A simplified ionic model of the cardiac action potential (AP), which can be fitted to a wide variety of experimentally and numerically obtained mesoscopic characteristics of cardiac tissue such as AP shape and restitution of AP duration and conduction velocity, is used to explain many different mechanisms of spiral wave breakup which in principle can occur in cardiac tissue. Some, but not all, of these mechanisms have been observed before using other models; therefore, the purpose of this paper is to demonstrate them using just one framework model and to explain the different parameter regimes or physiological properties necessary for each mechanism (such as high or low excitability, corresponding to normal or ischemic tissue, spiral tip trajectory types, and tissue structures such as rotational anisotropy and periodic boundary conditions). Each mechanism is compared with data from other ionic models or experiments to illustrate that they are not model-specific phenomena. Movies showing all the breakup mechanisms are available at http://arrhythmia.hofstra.edu/breakup and at ftp://ftp.aip.org/epaps/chaos/E-CHAOEH-12-039203/ INDEX.html. The fact that many different breakup mechanisms exist has important implications for antiarrhythmic drug design and for comparisons of fibrillation experiments using different species, electromechanical uncoupling drugs, and initiation protocols.

  10. Mechanism of ternary breakup in the reaction {sup 197}Au+{sup 197}Au at 15A MeV

    SciTech Connect

    Tian Junlong [China Institute of Atomic Energy, P.O. Box 275(18), Beijing 102413 (China); College of Physics and Electrical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Wu Xizhen; Li Zhuxia; Zhao Kai; Zhang Yingxun [China Institute of Atomic Energy, P.O. Box 275(18), Beijing 102413 (China); Li Xian; Yan Shiwei [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

    2010-11-15

    The mechanism of the ternary breakup of the very heavy system {sup 197}Au+{sup 197}Au at an energy of 15A MeV has been studied by using the improved quantum molecular dynamics model. The calculation results reproduce the characteristic features in ternary breakup events explored in a series of experiments; i.e., the masses of three fragments are comparable in size and the very fast, nearly collinear breakup of the colliding system is dominant in the ternary breakup events. Further, the evolution of the time scales of different ternary reaction modes and the behavior of mass distributions of three fragments with impact parameters are studied. The time evolution of the configurations of the composite reaction systems is also studied. We find that for most of the ternary breakup events with the features found in the experiments, the configuration of the composite system has two-preformed-neck shape. The study shows that those ternary breakup events having the characteristic features found in the experiments happen at relatively small impact parameter reactions, but not at peripheral reactions. The ternary breakup reaction at peripheral reactions belongs to binary breakup with a neck emission.

  11. Break-up mechanisms in heavy ion collisions at low energies

    E-print Network

    Shvedov, L; Di Toro, M

    2010-01-01

    We investigate reaction mechanisms occurring in heavy ion collisions at low energy (around 20 MeV/u). In particular, we focus on the competition between fusion and break-up processes (Deep-Inelastic and fragmentation) in semi-peripheral collisions, where the formation of excited systems in various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration, described in terms of shape observables such as quadrupole and octupole moments, we derive fusion/fission probabilities, from which one can finally evaluate the corresponding fusion and break-up cross sections. The dependence of the results on shape, angular momentum and excitation energy is discussed.

  12. Measurement of tensor polarization of deuterons from 3He?d+p breakup at momenta from 4.60 to 5.66 GeV/c

    NASA Astrophysics Data System (ADS)

    Sitnik, I. M.; Perdrisat, C. F.; Tomasi-Gustafsson, E.; Ball, J.; Bimbot, L.; Bisson, Y.; Boivin, M.; Borzunov, Yu. T.; Boyard, J. L.; Courtat, Ph.; Gacougnolle, R.; Golovanov, L. B.; Hennino, T.; Jones, M. K.; Kunne, R.; Malinina, L. V.; Nedev, S.; Piskunov, N. M.; Punjabi, V.; Sans, J. L.; Skowron, R.; Strokovsky, E. A.; Yonnet, J.

    2011-09-01

    The tensor polarization ?20 of deuterons emitted in the 1H(3He,d?)X reaction at 0? in the laboratory system was measured at the Saturne National Laboratory in Saclay using the SPES-4 spectrometer with the HYPOM polarimeter located downstream from its focal plane. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the 3He beam was varied from 4.60 to 5.66 GeV/c, thus providing a range of internal momenta k of the deuteron in 3He from 0 up to 0.4 GeV/c. The data obtained are compared with theoretical predictions.

  13. Measurement of tensor polarization of deuterons from 3He ? d + p breakup at internal momenta up to 0.4 GeV/c

    NASA Astrophysics Data System (ADS)

    Sitnik, I. M.; Perdrisat, C. F.; Tomasi-Gustafsson, E.; Ball, J.; Bimbot, L.; Bisson, Y.; Boivin, M.; Borzunov, Yu T.; Boyard, J. L.; Courtat, Ph; Gacougnolle, R.; Garçon, M.; Golovanov, L. B.; Hennino, T.; Jones, M. K.; Kunne, R.; Malinina, L. V.; Nedev, S.; Piskunov, N. M.; Punjabi, V.; Sans, J. L.; Skowron, R.; Strokovsky, E. A.; Yonnet, J.

    2011-05-01

    The tensor polarization (?20) of deuterons emitted in the p(3He,d)X reaction at 0° in the lab. system was measured at the Saturne National Laboratory in Saclay, using the SPES-4 spectrometer with the HYPOM polarimeter in the area of its focal plane. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the 3He beam was varied from 4.60 to 5.66 GeV/c, thus providing a range of internal momenta k of the deuteron inside the 3He from 0 up to 0.4 GeV/c. The obtained data are compared with the theoretical predictions.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  16. The role of mechanical heterogeneities during continental breakup: a 3D lithospheric-scale modelling approach

    NASA Astrophysics Data System (ADS)

    Duclaux, Guillaume; Huismans, Ritske S.; May, Dave

    2015-04-01

    How and why do continents break? More than two decades of analogue and 2D plane-strain numerical experiments have shown that despite the origin of the forces driving extension, the geometry of continental rifts falls into three categories - or modes: narrow rift, wide rift, or core complex. The mode of extension itself is strongly influenced by the rheology (and rheological behaviour) of the modelled layered system. In every model, an initial thermal or mechanical heterogeneity, such as a weak seed or a notch, is imposed to help localise the deformation and avoid uniform stretching of the lithosphere by pure shear. While it is widely accepted that structural inheritance is a key parameter for controlling rift localisation - as implied by the Wilson Cycle - modelling the effect of lithospheric heterogeneities on the long-term tectonic evolution of an extending plate in full 3D remains challenging. Recent progress in finite-element methods applied to computational tectonics along with the improved accessibility to high performance computers, now enable to switch from plane strain thermo-mechanical experiments to full 3D high-resolution experiments. Here we investigate the role of mechanical heterogeneities on rift opening, linkage and propagation during extension of a layered lithospheric systems with pTatin3d, a geodynamics modeling package utilising the material-point-method for tracking material composition, combined with a multigrid finite-element method to solve heterogeneous, incompressible visco-plastic Stokes problems. The initial model setup consists in a box of 1200 km horizontally by 250 km deep. It includes a 35 km layer of continental crust, underlaid by 85 km of sub-continental lithospheric mantle, and an asthenospheric mantle. Crust and mantle have visco-plastic rheologies with a pressure dependent yielding, which includes strain weakening, and a temperature, stress, strain-rate-dependent viscosity based on wet quartzite rheology for the crust, and wet olivine for the mantle. A constant extension rate is imposed on two opposite walls in the horizontal direction; the model' surface evolves freely; an isostatic boundary condition is imposed on the bottom wall. We explore a range of weak notches geometries, as well as the presence of random noise across a central region of the model. We compare the evolution of the geometry of the surface rift segments, their linkage and faults propagation during ongoing extension. These models allow us to assess the importance of mechanical heterogeneities for controlling passive margin geometries, and to precise the underlying physics governing continental breakup.

  17. Neutron-Deuteron Breakup and Quasielastic Scattering

    Microsoft Academic Search

    Alice Ohlson; June Matthews; Wilbur Franklin; Brian Daub; Taylan Akdogan; Mark Yuly; Steven Wallace; Stephen Thomson; Daniel Haas

    2008-01-01

    Quasielastic scattering in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The scattered neutrons from the d(n,np)n reaction are detected by a wall of neutron time-of-flight scintillators, and scattered protons are detected by a permanent magnet spectrometer with two

  18. Description of Jet Breakup

    NASA Technical Reports Server (NTRS)

    Papageorgiou, Demetrios T.

    1996-01-01

    In this article we review recent results on the breakup of cylindrical jets of a Newtonian fluid. Capillary forces provide the main driving mechanism and our interest is in the description of the flow as the jet pinches to form drops. The approach is to describe such topological singularities by constructing local (in time and space) similarity solutions from the governing equations. This is described for breakup according to the Euler, Stokes or Navier-Stokes equations. It is found that slender jet theories can be applied when viscosity is present, but for inviscid jets the local shape of the jet at breakup is most likely of a non-slender geometry. Systems of one-dimensional models of the governing equations are solved numerically in order to illustrate these differences.

  19. Stream breakup by waves

    NASA Astrophysics Data System (ADS)

    Samuelsen, G. S.; Ateshkadi, Arash

    1995-04-01

    An imaging technique is used to investigate the fluid dynamics associated with the breakup of a liquid jet by a passing transverse shock wave. This mechanism is believed to be a potential source of combustion instability in liquid propellant rocket engines. Combustion instability is caused by the release of heat in phase with a passing pressure disturbance. The jet/wave interaction causes rapid atomization and propellant redistribution, and enhances mixing, vaporization, and reaction rates. Knowledge of the breakup process aids in prediction of local heat release with respect to the passing wave and provides insight on its viability as a potential instability mechanism. The present shock tube study applies high-speed, high-resolution photography to explore the jet/wave interaction that might be experienced in a large scale liquid oxygen/hydrogen (LOX/H2) engine similar to the Space Shuttle Main Engine (SSME) or other such engines being considered for the next generation of launch systems. Fluid parameters deemed important were simulated as well as possible. Two types of wave induced breakup were examined: a constant velocity flow field (square wave) and an exponentially decaying velocity field (N-wave). Time resolved images of the jet/wave interaction indicate very rapid and fire atomization within 500 microns of impingement. Shock interaction with the primary atomization process produces a substantial change to the breakup mechanism and serves as a principal candidate for the promotion and acceleration of rocket engine instability. Results of the qualitative and quantitative study reveal that the step wave produces a long duration tangential and normal stress on the liquid column as compared to the N-wave. As a result, N-waves decelerate jet displacement and extend the jet breakup time.

  20. 2 dimensional finite stochastic breakup model of biomass particle breakup.

    PubMed

    Guo, Qiang; Liu, Haifeng; Chen, Xueli

    2013-02-01

    Due to the high content of cellulose, hemicellulose and lignin, the anisotropy of biomass particle in spatial structure induces the difference of mechanical properties in different directions. In this paper, based on the finite stochastic breakup model and anisotropy of biomass particles, 2-dimensional finite stochastic breakup model (2D-FSBM) of biomass particle was proposed, and the breakup process of biomass particle was investigated. In this model, the strength difference in different directions and the minimum mass ratio of a sub-particle to the parent particle were both considered. The simulation results agreed well with the experimental results in particle shapes, which indicated that 2D-FSBM could predict the breakup process of biomass particles. PMID:23232219

  1. Note on Breakup Densities in Fragmentation

    E-print Network

    V. E. Viola

    2007-05-02

    This note elaborates the procedures involved in the derivation of breakup densities in nuclear fragmentation. It is stressed that the formalism employed in the analysis served only as a spectral fitting function and does not imply any specific reaction mechanism.

  2. Theoretical Modeling of J/psi Yield Modifications in Proton (Deuteron) - Nucleus Collisions at High Energy

    E-print Network

    J. L. Nagle; A. D. Frawley; L. A. Linden Levy; M. G. Wysocki

    2010-11-19

    Understanding the detailed production and hadronization mechanisms for heavy quarkonia and their modification in a nuclear environment presents one of the major challenges in QCD. Calculations including nuclear-modified parton distribution functions (nPDFs) and fitting of break-up cross sections (sigma_breakup) as parameters have been successful at describing many features of J/psi modification in proton(deuteron)-nucleus collisions. In this paper, we extend these calculations to explore different geometric dependencies of the modification and confront them with new experimental results from the PHENIX experiment. We find that no combination of nPDFs and sigma_breakup, regardless of the nPDF parameter set and the assumed geometric dependence, can simultaneously describe the entire rapidity and centrality dependence of J/psi modifications in d+Au collisions at sqrt(s_NN) = 200 GeV. We also compare the data with coherence calculations and find them unable to describe the full rapidity and centrality dependence as well. We discuss how these calculations might be extended and further tested, in addition to discussing other physics mechanisms including initial-state parton energy loss.

  3. Polarization in three-nucleon breakup: experiment and theory

    SciTech Connect

    Brown, R.E.; Hardekopf, R.A.; Jarmie, N.; Correll, F.D.; Lambert, J.M.; Treado, P.A.; Slaus, I.; Schwandt, P.; Jacobs, W.W.; Meyer, H.O.

    1984-01-01

    A variety of analyzing powers for d+p breakup reactions initiated by polarized deuterons incident on protons have been measured at deuteron bombarding energies of 16 and 79 MeV. The results are compared with Faddeev calculations using both separable (at 16 and 79 MeV) and local (at 79 MeV) interactions. These calculations include nucleon-nucleon forces in the S, P, and D states and the /sup 3/S/sub 1/-/sup 3/D/sub 1/ tensor force. 19 references.

  4. Semiclassical theory of fusion and breakup reactions

    SciTech Connect

    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

    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.

  5. Geometrical deuteron stripping revisited

    SciTech Connect

    Neoh, Y. S.; Yap, S. L. [Plasma Research Technology Center, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05

    We investigate the reality of the idea of geometrical deuteron stripping originally envisioned by Serber. By taking into account of realistic deuteron wavefunction, nuclear density, and nucleon stopping mean free path, we are able to estimate inclusive deuteron stripping cross section for deuteron energy up to before pion production. Our semiclassical model contains only one global parameter constant for all nuclei which can be approximated by Woods-Saxon or any other spherically symmetric density distribution.

  6. Effective radii of deuteron induced reactions

    E-print Network

    Shintaro Hashimoto; Masanobu Yahiro; Kazuyuki Ogata; Kosho Minomo; Satoshi Chiba

    2011-04-08

    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 $d+^{58}$Ni scattering at 200 MeV/nucleon and ERT does data on the neutron-stripping cross section for inclusive $^7$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, complete- and incomplete-fusion cross sections is clearly explained by simple formulae. Accuracy of the Glauber model is also investigated.

  7. Muon Capture on the Proton and Deuteron

    E-print Network

    Frederick Gray

    2008-08-11

    By measuring the lifetime of the negative muon in pure protium (hydrogen-1), the MuCap experiment determines the rate of muon capture on the proton, from which the proton's pseudoscalar coupling g_p may be inferred. A precision of 15% for g_p has been published; this is a step along the way to a goal of 7%. This coupling can be calculated precisely from heavy baryon chiral perturbation theory and therefore permits a test of QCD's chiral symmetry. Meanwhile, the MuSun experiment is in its final design stage; it will measure the rate of muon capture on the deuteron using a similar technique. This process can be related through pionless effective field theory and chiral perturbation theory to other two-nucleon reactions of astrophysical interest, including proton-proton fusion and deuteron breakup.

  8. Peripherality of breakup reactions

    NASA Astrophysics Data System (ADS)

    Capel, P.; Nunes, F. M.

    2007-05-01

    The sensitivity of elastic breakup to the interior of the projectile wave function is analyzed. Breakup calculations of loosely bound nuclei (B8 and Be11) 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.

  9. Bubble Breakup Caused by Shape Instabilities

    NASA Astrophysics Data System (ADS)

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

    1998-11-01

    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 investigate the breakup of a single ideal gas bubble oscillating in an infinite region of an inviscid and incompressible fluid due to the one-to two resonance mechanism. Boundary element method combined with 4-th order Runge-Kutta integrator is used to simulate the bubble motion. Several simulations with different time steps are conducted to ensure the convergence of numerical integration. Conservation of energy is used as a measure of justifying the accuracy of our calculation. Our numerical data shows that the velocity of two poles of an axisymmetric bubble starts to vary at a very high frequency before the bubble breaks up. Several flow fields just before the breakup show that the velocity at the two poles is much larger than the velocity elsewhere.

  10. Coastal landfast sea ice decay and breakup in northern Alaska: Key processes and seasonal prediction

    NASA Astrophysics Data System (ADS)

    Petrich, Chris; Eicken, Hajo; Zhang, Jing; Krieger, Jeremy; Fukamachi, Yasushi; Ohshima, Kay I.

    2012-02-01

    Seasonal breakup of landfast sea ice consists of movement and irreversible ice detachment in response to winds or oceanic forces in the late stages of ice decay. The breakup process of landfast sea ice in the Chukchi Sea at Barrow, Alaska, was analyzed for the years 2000 through 2010 on the basis of local observations of snow and ice conditions, weather records, image sequences obtained from cameras, coastal X band marine radar, and satellite imagery. We investigated the relation of breakup to winds, tides, and nearshore current measurements from a moored acoustic Doppler current profiler. Two breakup modes are distinguished at Barrow on the basis of the degree of ice decay. Mechanical breakup due to wind and oceanic forces follows ablation and weakening of the ice. Thermal breakup is the result of ice disintegration under melt ponds, requiring little force to induce dispersion. Grounded pressure ridges are pivotal in determining the breakup mode. The timing of thermal breakup of the nearshore ice cover was found to correlate with the measured downwelling solar radiation in June and July. This linkage allows for the development of an operational forecast of landfast ice breakup. Results from forecasts during 2 years demonstrate that thermal breakup can be predicted to within a couple of days 2 weeks in advance. The cumulative shortwave energy absorbed by the ice cover provides for a measure of the state of ice decay and potential for disintegration. Discriminating between the two modes of breakup bears the potential to greatly increase forecasting skill.

  11. Supercontinent break-up: Causes and consequences

    NASA Astrophysics Data System (ADS)

    Li, Z. X.

    2014-12-01

    Supercontinent break-up has most commonly been linked to plume or superplume events, and/or supercontinent thermal insulation, but precise mechanisms are yet to be worked out. Even less know is if and what roles other factors may play. Key factors likely include gravitational force due to the continental superswell driven by both the lower-mantle superplume and continental thermal insulation, mental convention driven by the superplume and individual plumes atop the superplume, assisted by thermal/magmatic weakening of the supercontinent interior (both plume heat and thermal insulation heat). In addition, circum-supercontinent slab downwelling may not only drive the formation of the antipodal superplumes (thus the break-up of the supercontinent), the likely roll-back of the subduction system would also create extension within the supercontinent, facilitating supercontinent break-up. Consequences of supercontinent break-up include long-term sea-level rise, climatic changes due to changes in ocean circulation pattern and carbon cycle, and biodiversification. It has long been demonstrated that the existence of the supercontinent Pangea corresponds to a long-term sea-level drop, whereas the break-up of the supercontinent corresponds to a long-term sea-level rise (170 m higher than it is today). A recent analysis of Neoproterozoic sedimentary facies illustrates that the time of Neoproterozoic supercontinent Rodinia corresponds to a low in the percentage of deep marine facies occurrence, whereas the time of Rodinia break-up corresponds to a significantly higher percentage of deep marine facies occurrence. The long-tern sea-level drop during supercontinent times were likely caused by both plume/superplume dynamic topography and an older mean age of the oceanic crust, whereas long-tern sea-level rise during supercontinent break-up (720-580 Ma for Rodinia and Late Jurassic-Cretaceous for Pangea) likely corresponds to an younger mean age of the oceanic crust, massive plume-induced magmatism in the oceans, and perhaps the effect of continents drifting away from a weakening sub-supercontinent superplume.

  12. Large Q2 electrodisintegration of the deuteron in the virtual nucleon approximation

    NASA Astrophysics Data System (ADS)

    Sargsian, Misak M.

    2010-07-01

    The two-body breakup of the deuteron is studied at high-Q2 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-Q2 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 Q2. We demonstrate that the experimental data confirm the GEA’s early prediction that the rescattering is maximal at ~70° 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 ?-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.

  13. Low-energy neutron-deuteron reactions with N 3 LO chiral forces

    NASA Astrophysics Data System (ADS)

    Golak, J.; Skibi?ski, R.; Topolnicki, K.; Wita?a, H.; Epelbaum, E.; Krebs, H.; Kamada, H.; Meißner, Ulf-G.; Bernard, V.; Maris, P.; Vary, J.; Binder, S.; Calci, A.; Hebeler, K.; Langhammer, J.; Roth, R.; Nogga, A.; Liebig, S.; Minossi, D.

    2014-11-01

    We solve three-nucleon Faddeev equations with nucleon-nucleon and three-nucleon forces derived consistently in the framework of chiral perturbation theory at next-to-next-to-next-to-leading order in the chiral expansion. In this first investigation we include only matrix elements of the three-nucleon force for partial waves with the total two-nucleon (three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron elastic scattering and deuteron breakup reaction are studied. Emphasis is put on A y puzzle in elastic scattering and cross sections in symmetric-space-star and neutron-neutron quasi-free-scattering breakup configurations, for which large discrepancies between data and theory have been reported.

  14. The Flat Deuteron

    E-print Network

    Omar Yepez

    2005-10-18

    The new model was applied to the femtometer toroidal structures found for the deuteron. It was possible to relate the magnetic moment and the energy of the particle to the torus geometric parameters. Excellent agreement between the magnetic moment of the deuteron and the theory developed for a time consuming intersecting 3D torus in a 2D space was found. It was possible to discriminate between which structures present a magnetic moment and which one would produce an anapole moment. This supports the concept that there are orientations of the torus that make it lose its magnetic moment, which is the key to understanding the EPR paradox. The mass energy of the particle changed with each structure, but the mass density was constant, which is consistent with the tension exerted on the space as the source of the particle's "mass" or more appropriately said the particle's density.

  15. Generation and breakup of Worthington jets after cavity collapse. Part 2. Tip breakup of stretched jets

    Microsoft Academic Search

    J. M. Gordillo; Stephan Gekle

    2010-01-01

    The capillary breakup of the high-speed Worthington jets ejected after a cavity collapse in water occurs due to the high-Reynolds-number version of the capillary end-pinching mechanism first described, in the creeping flow limit, by Stone & Leal (J. Fluid Mech., vol. 198, 1989, p. 399). Using potential flow numerical simulations and theory, we find that the resulting drop ejection process

  16. Contrasting Historical and Recent Breakup Styles on the Meade River of Arctic Alaska in the Context of a Warming Climate

    NASA Astrophysics Data System (ADS)

    Beck, R. A.; Hinkel, K. M.; Eisner, W. R.; Whiteman, D.; Arp, C. D.; Machida, R.; Cuomo, C.; Su, H.; Liu, H.; Kim, C.; Rettig, A.; Ivenso, C.; Yang, B.; Wu, Q.; Wang, S.; Frey, K. E.; Lenters, J. D.; Potter, B. L.

    2013-12-01

    Although data for temporal spring river ice breakup are available for a number of Arctic rivers, there is a paucity of information related to the type of breakup. The Arctic Climate Impact Assessment (ACIA) of 2005 predicted a transition from mechanical to thermal spring breakup of ice cover on arctic rivers, with this shift being greatest in exclusively Arctic watersheds where observed warming is most pronounced. We describe a rare instance of an entirely Arctic river with limited but well documented historical and recent data regarding the type of breakup. Time-series ground imagery of spring breakup from 1966, 1975, 1978, 2009, 2010 and 2012, in combination with interviews of local inhabitants, documents a shift from predominantly mechanical to predominantly thermal breakup after spring 1978 and by spring 2009 within the context of a locally and regionally warming Arctic. Recent (post-2010) and rare cloud-free visible satellite imagery shows an irregular pattern of breakup along the southern two thirds of the river. The resultant shift from predominantly mechanical to predominantly thermal breakup is predicted to result in significant changes to water, sediment, nutrient and organic carbon fluxes, as well as riparian ecology and human activities. Meade River Breakup - Spring 1966 Meade River Breakup - Spring 2010

  17. Solar Wind-Magnetosphere Coupling Influences on Pseudo-Breakup Activity

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Brittnacher, M.; Parks, G. K.; Germany, G. A.; Spann, J. F.

    1998-01-01

    Pseudo-breakups are brief, localized aurora[ arc brightening, which do not lead to a global expansion, are historically observed during the growth phase of substorms. Previous studies have demonstrated that phenomenologically there is very little difference between substorm onsets and pseudo-breakups except for the degree of localization and the absence of a global expansion phase. A key open question is what physical mechanism prevents a pseudo-breakup form expanding globally. Using Polar Ultraviolet Imager (UVI) images, we identify periods of pseudo-breakup activity. Foe the data analyzed we find that most pseudo-breakups occur near local midnight, between magnetic local times of 21 and 03, at magnetic latitudes near 70 degrees, through this value may change by several degrees. While often discussed in the context of substorm growth phase events, pseudo-breakups are also shown to occur during prolonged relatively inactive periods. These quiet time pseudo-breakups can occur over a period of several hours without the development of a significant substorm for at least an hour after pseudo-breakup activity stops. In an attempt to understand the cause of quiet time pseudo-breakups, we compute the epsilon parameter as a measure of the efficiency of solar wind-magnetosphere coupling. It is noted that quiet time pseudo-breakups occur typically when epsilon is low; less than about 50 GW. We suggest that quiet time pseudo-breakups are driven by relatively small amounts of energy transferred to the magnetosphere by the solar wind insufficient to initiate a substorm expansion onset.

  18. Drop Breakup in Fixed Bed Flows as Model Stochastic Flow Fields

    NASA Technical Reports Server (NTRS)

    Shaqfeh, Eric S. G.; Mosler, Alisa B.; Patel, Prateek

    1999-01-01

    We examine drop breakup in a class of stochastic flow fields as a model for the flow through fixed fiber beds and to elucidate the general mechanisms whereby drops breakup in disordered, Lagrangian unsteady flows. Our study consists of two parallel streams of investigation. First, large scale numerical simulations of drop breakup in a class of anisotropic Gaussian fields will be presented. These fields are generated spectrally and have been shown in a previous publication to be exact representations of the flow in a dilute disordered bed of fibers if close interactions between the fibers and the drops are dynamically unimportant. In these simulations the drop shape is represented by second and third order small deformation theories which have been shown to be excellent for the prediction of drop breakup in steady strong flows. We show via these simulations that the mechanisms of drop breakup in these flows are quite different than in steady flows. The predominant mechanism of breakup appears to be very short lived twist breakups. Moreover, the occurrence of breakup events is poorly predicted by either the strength of the local flow in which the drop finds itself at breakup, or the degree of deformation that the drop achieves prior to breakup. It is suggested that a correlation function of both is necessary to be predictive of breakup events. In the second part of our research experiments are presented where the drop deformation and breakup in PDMS/polyisobutylene emulsions is considered. We consider very dilute emulsions such that coalescence is unimportant. The flows considered are simple shear and the flow through fixed fiber beds. Turbidity, small angle light scattering, dichroism and microscopy are used to interrogate the drop deformation process in both flows. It is demonstrated that breakup at very low capillary numbers occurs in both flows but larger drop deformation occurs in the fixed bed flow. Moreover, it is witnessed that breakup in the bed occurs continuously during flow and apparently with uniform probability through the bed length. The drop deformations witnessed in our experiments are larger than those predicted by the numerical simulations, and future plans to investigate these differences are discussed.

  19. Deuteron and anti-deuteron production in CERN experiment NA44

    SciTech Connect

    Simon-Gillo, J.

    1995-04-01

    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.

  20. Electrohydrodynamic (EHD) stimulation of jet breakup

    NASA Technical Reports Server (NTRS)

    Crowley, J. M.

    1982-01-01

    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.

  1. High Energy Break-Up of Few-Nucleon Systems

    NASA Astrophysics Data System (ADS)

    Sargsian, Misak

    2008-03-01

    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.

  2. Electromagnetic Structure of the Deuteron

    SciTech Connect

    Franz Gross

    2002-06-01

    Recent high energy measurements of elastic ed scattering support the use of a relativistic theory based on an accurate description of the NN channel, but theory needed for an understanding of the high energy deuteron photodisintegration cross sections and polarized observables is not yet mature.

  3. Antimisting fuel breakup and flammability

    NASA Technical Reports Server (NTRS)

    Parikh, P.; Fleeter, R.; Sarohia, V.

    1983-01-01

    The breakup behavior and flammability of antimisting turbine fuels subjected to aerodynamic shear are investigated. Fuels tested were Jet A containing 0.3% FM-9 polymer at various levels of degradation ranging from virgin AMK to neat Jet A. The misting behavior of the fuels was quantified by droplet size distribution measurements. A technique based on high resolution laser photography and digital image processing of photographic records for rapid determination of droplet size distribution was developed. The flammability of flowing droplet-air mixtures was quantified by direct measurements of temperature rise in a flame established in the wake of a continuous ignition source. The temperature rise measurements were correlated with droplet size measurements. The flame anchoring phenomenon associated with the breakup of a liquid fuel in the wake of bluff body was shown to be important in the context of a survivable crash scenario. A pass/fail criterion for flammability testing of antimisting fuels, based on this flame-anchoring phenomenon, was proposed. The role of various ignition sources and their intensity in ignition and post-ignition behavior of antimisting fuels was also investigated.

  4. Deuteron and anti-deuteron production in ee collisions at the Z resonance

    NASA Astrophysics Data System (ADS)

    ALEPH Collaboration; Schael, S.; Barate, R.; Brunelière, R.; de Bonis, I.; Decamp, D.; Goy, C.; Jézéquel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocmé, B.; Bravo, S.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Filippis, N.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Barklow, T.; Buchmüller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R. W.; Frank, M.; Gianotti, F.; Hansen, J. B.; Harvey, J.; Hutchcroft, D. E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J. M.; Perret, P.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Kraan, A. C.; Nilsson, B. S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rougé, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, G. P.; Passalacqua, L.; Kennedy, J.; Lynch, J. G.; Negus, P.; O'Shea, V.; Thompson, A. S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Cameron, W.; Davies, G.; Dornan, P. J.; Girone, M.; Marinelli, N.; Nowell, J.; Rutherford, S. A.; Sedgbeer, J. K.; Thompson, J. C.; White, R.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C. K.; Clarke, D. P.; Ellis, G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Pearson, M. R.; Robertson, N. A.; Sloan, T.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Hölldorfer, F.; Jakobs, K.; Kayser, F.; Müller, A.-S.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Hüttmann, K.; Lütjens, G.; Männer, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Foà, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P. G.; Awunor, O.; Blair, G. A.; Cowan, G.; Garcia-Bellido, A.; Green, M. G.; Medcalf, T.; Misiejuk, A.; Strong, J. A.; Teixeira-Dias, P.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Tomalin, I. R.; Ward, J. J.; Bloch-Devaux, B.; Boumediene, D.; Colas, P.; Fabbro, B.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, B.; Litke, A. M.; Taylor, G.; Booth, C. N.; Cartwright, S.; Combley, F.; Hodgson, P. N.; Lehto, M.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S. R.; Berkelman, K.; Cranmer, K.; Ferguson, D. P. S.; Gao, Y.; González, S.; Hayes, O. J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P. A.; Nielsen, J.; Pan, Y. B.; von Wimmersperg-Toeller, J. H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.

    2006-08-01

    Deuteron and anti-deuteron production in Z decays has been observed in the ALEPH experiment at LEP. The production rate of anti-deuterons is measured to be (5.9±1.8±0.5)×10 per hadronic Z decay in the anti-deuteron momentum range from 0.62 to 1.03 GeV/c. The coalescence parameter B, which characterizes the likelihood of anti-deuteron production, is measured to be 0.0033±0.0013 GeV in Z decays. These measurements indicate that the production of anti-deuterons is suppressed in ee collisions compared to that in pp and photoproduction collisions.

  5. Intrusive Thoughts: A Primary Variable in Breakup Distress

    ERIC Educational Resources Information Center

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

    2013-01-01

    University students who were high versus low on breakup distress scores were given self-report measures to assess their intrusive thoughts about the romantic breakup and their somatic symptoms that followed the breakup as well as their extracurricular activities and social support that might alleviate their breakup distress. In a regression…

  6. The naming of the deuteron

    NASA Astrophysics Data System (ADS)

    Stuewer, Roger H.

    1986-03-01

    The naming of the deuteron involved a protracted debate between 1933 and 1935. The principal protagonists were Harold C. Urey, Gilbert N. Lewis, Ernest O. Lawrence, and Ernest Rutherford, but others on both sides of the Atlantic entered the fray as well. This paper examines the arguments and issues that emerged in the debate, and the process by which agreement was finally achieved on the name for this new particle.

  7. Deuteron photodisintegration with polarized lasers

    E-print Network

    G. Ramachandran; S. P. Shilpashree

    2011-04-07

    A model independent theoretical analysis of recent experimental data on deuteron photodisintegration with polarized laser beams is presented. We find that it is important to distinguish between the three isovector E1 amplitudes $E1_v^j$ in reaction channels with total angular momentum $j=0,1,2$ and that the isoscalar M1 amplitude $M1_s$ is non-zero in the photon energy range $3.5 MeV < E_\\gamma < 10 MeV$

  8. Nonlocality in deuteron stripping reactions.

    PubMed

    Timofeyuk, N K; Johnson, R C

    2013-03-15

    We propose a new method for the analysis of deuteron stripping reactions, A(d,p)B, in which the nonlocality of nucleon-nucleus interactions and three-body degrees of freedom are accounted for in a consistent way. The model deals with equivalent local nucleon potentials taken at an energy shifted by ?40??MeV from the "E(d)/2" value frequently used in the analysis of experimental data, where E(d) is the incident deuteron energy. The "E(d)/2" rule lies at the heart of all three-body analyses of (d, p) reactions performed so far with the aim of obtaining nuclear structure properties such as spectroscopic factors and asymptotic normalization coefficients that are crucial for our understanding of nuclear shell evolution in neutron- and proton-rich regions of the nuclear periodic table and for predicting the cross sections of stellar reactions. The large predicted shift arises from the large relative kinetic energy of the neutron and proton in the incident deuteron in those components of the n+p+A wave function that dominate the (d, p) reaction amplitude. The large shift reduces the effective d-A potentials and leads to a change in predicted (d, p) cross sections, thus affecting the interpretation of these reactions in terms of nuclear structure. PMID:25166525

  9. Capillary breakup of Discontinuously Rate Thickening Suspensions

    E-print Network

    Zimoch, Pawel

    2012-01-01

    In this study, we investigated the behavior of Discontinuously Rate Thickening Suspensions (DRTS) in capillary breakup, where a thin suspension filament breaks up under the action of surface tension forces. We performed ...

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

    SciTech Connect

    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

    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.

  11. Supercontinent Breakup and the Deep Earth

    NASA Astrophysics Data System (ADS)

    Torsvik, T. H.

    2014-12-01

    As many as five supercontinents have been proposed and the deep Earth probably holds the key to understand their breakup. The African and Pacific large low shear-wave velocity provinces (LLSVPs) have been stable for the entire Phanerozoic and possibly much longer. Their edges are the dominant source of deep plumes which travel from the base of the mantle to the surface where episodic large igneous province (LIP) activity has punctuated plate tectonics by creating and modifying plate boundaries. Pangea, the best-documented supercontinent, formed at the end of the Carboniferous (320 Ma) by fusing Gondwana and Laurussia. The Panjal Traps (289 Ma) probably assisted in an early Pangea breakup phase (opening of the Neotethys) but the most important phase of breakup started when the Central Atlantic Ocean opened at around 195 Ma. Perhaps not coincidentally, the region where the Atlantic spreading started was preceded by the emplacement of the Central Atlantic Magmatic Province (201 Ma), one of the largest LIPs. The Karoo LIP (183 Ma) heralded the Jurassic breakup of Pangea (separation of East and West Gondwana) whereas Paraná-Etendeka LIP activity (134 Ma) preceded South Atlantic break-up by a few million years. The North Atlantic realm experienced prolonged Late Palaeozoic to Cenozoic extension and sedimentary basin formation but the final Early Eocene break-up occurred shortly after a massive episode of volcanism and LIP formation (North Atlantic Igneous Province, 62 Ma) as in most Pangea breakup examples. All LIPs assisting Pangea breakup were sourced by plumes from the margin of the African LLSVP.

  12. On the breakup of viscous liquid threads

    NASA Technical Reports Server (NTRS)

    Papageorgiou, Demetrios T.

    1995-01-01

    A one-dimensional model evolution equation is used to describe the nonlinear dynamics that can lead to the breakup of a cylindrical thread of Newtonian fluid when capillary forces drive the motion. The model is derived from the Stokes equations by use of rational asymptotic expansions and under a slender jet approximation. The equations are solved numerically and the jet radius is found to vanish after a finite time yielding breakup. The slender jet approximation is valid throughout the evolution leading to pinching. The model admits self-similar pinching solutions which yield symmetric shapes at breakup. These solutions are shown to be the ones selected by the initial boundary value problem, for general initial conditions. Further more, the terminal state of the model equation is shown to be identical to that predicted by a theory which looks for singular pinching solutions directly from the Stokes equations without invoking the slender jet approximation throughout the evolution. It is shown quantitatively, therefore, that the one-dimensional model gives a consistent terminal state with the jet shape being locally symmetric at breakup. The asymptotic expansion scheme is also extended to include unsteady and inerticial forces in the momentum equations to derive an evolution system modelling the breakup of Navier-Stokes jets. The model is employed in extensive simulations to compute breakup times for different initial conditions; satellite drop formation is also supported by the model and the dependence of satellite drop volumes on initial conditions is studied.

  13. Nonlocality and the radius of the deuteron

    Microsoft Academic Search

    M. W. Kermode; S. A. Moszkowski; M. M. Mustafa; W. van Dijk

    1991-01-01

    We consider the effects of nonlocality on the determination of the deuteron radius for model potentials. We show that the relation between the model values for the radius and the scattering length which holds for local potentials is not necessarily valid for nonlocal potentials. It is possible for nonlocal potential models to produce a deuteron of smaller radius as required

  14. Structure effects in the deuteron wavefunction

    Microsoft Academic Search

    M. W. Kermode; W. van Dijk; D. W. L. Sprung; M. M. Mustafa; S. A. Moszkowski

    1991-01-01

    The authors present deuteron wavefunctions that are radically different from the conventional ones at short distances. These wavefunctions give a value of the root mean square radius of the deuteron in agreement with the experimental result. Also, they arise from a potential that reproduces the experimental value of the scattering length. These wavefunctions may be a reflection of the quark

  15. Spin-manipulating polarized deuterons

    SciTech Connect

    Morozov, V S; Krisch, A D; Leonova, M A; Raymond, R S; Sivers, D W; Wong, V K; Hinterberger, F; Kondratenko, A M

    2011-03-01

    Spin dynamics of polarized deuteron beams near depolarization resonances, including a new polarization preservation concept based on specially-designed multiple resonance crossings, has been tested in a series of experiments in the COSY synchrotron. Intricate spin dynamics with sophisticated pre-programmed patterns as well as effects of multiple crossings of a resonance were studied both theoretically and experimentally with excellent agreement. Possible applications of these results to preserve, manipulate and spin-flip polarized beams in synchrotrons and storage rings are discussed.

  16. Two-valued breakup length of a water jet issuing from a finite-length nozzle under normal gravity.

    PubMed

    Umemura, Akira; Kawanabe, Sho; Suzuki, Sousuke; Osaka, Jun

    2011-09-01

    Laboratory experiments are conducted in which water is issued vertically downward from a finite-length nozzle at a constant speed using a piston. The results of these experiments indicate that the breakup length of the liquid jet is two-valued at Weber numbers greater than unity but less than a certain value, which depends on the nozzle length-to-radius ratio and the Bond number. In addition to a long breakup length, which is consistent with the conventional observation, another shorter breakup length is realized at the same jet issue speed. Each experimental run for a specific jet issue speed begins from the start of liquid issue so that each run is independent of the other runs. Transition between the two breakup lengths seldom occurs in each run. Which of the two breakup lengths occurs is determined at the start of liquid issue, when the capillary wave produced by the liquid jet tip contraction easily reaches the nozzle exit. Unlike the conventional belief, which is based on the Plateau-Rayleigh instability theory, this experimental evidence demonstrates that liquid jet disintegration occurs in a deterministic manner. The previously proposed self-destabilizing mechanism of a liquid jet in microgravity, in which the origin of the unstable wave responsible for the breakups is attributed to the formation of an upstream propagating capillary wave at every breakup, is extended to explore the physics underlying the observed liquid jet disintegration behaviors. PMID:22060494

  17. The Breakup Cross Section of the D+D Reaction at 6.94 MeV

    NASA Astrophysics Data System (ADS)

    Richard, A. L.; Brune, C. R.; Ingram, D. C.; Dhakal, S.; Karki, A.; Massey, T. N.; O'Donnell, J. E.; Parker, C. E.

    2015-04-01

    The D+D reactions are well known and widely used for a variety of purposes, mainly due to the mono-energetic neutrons from the D(d , n) 3 He reaction. The least studied of the D+D reactions is the D(d , np) D reaction known as the deuteron breakup reaction. The D(d , np) D reaction produces a continuum of neutrons at energies lower than that of the mono-energetic peak. In this work, the D(d,np)D reaction has been studied for the purpose of use as a neutron source for the active interrogation of hidden fissile materials. The neutron energy distribution as a function of angle for the cross section, d2/? d?dE , of the D(d,np)D reaction has been measured at the Edwards Accelerator Laboratory of Ohio University, using a 6.94-MeV pulsed deuteron beam incident upon a D2 gas target. The time-of-flight technique was used to determine the energy of the neutrons detected in the array of two lithium glass scintillators and one NE-213 scintillator. The breakup cross section was determined as low as 225-keV neutron energy in the lithium glass detectors. This project was funded in part by the Defense Threat Reduction Agency (DTRA) through Grant Number HDTRA1-09-1-0059.

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

    SciTech Connect

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

    2009-07-15

    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)

  19. Deuteron and anti-deuteron production in e+e- collisions at the Z resonance

    NASA Astrophysics Data System (ADS)

    Schael, S.; Barate, R.; Brunelière, R.; de Bonis, I.; Decamp, D.; Goy, C.; Jézéquel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocmé, B.; Bravo, S.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Filippis, N.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Barklow, T.; Buchmüller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R. W.; Frank, M.; Gianotti, F.; Hansen, J. B.; Harvey, J.; Hutchcroft, D. E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J. M.; Perret, P.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Kraan, A. C.; Nilsson, B. S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rougé, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, G. P.; Passalacqua, L.; Kennedy, J.; Lynch, J. G.; Negus, P.; O'Shea, V.; Thompson, A. S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Cameron, W.; Davies, G.; Dornan, P. J.; Girone, M.; Marinelli, N.; Nowell, J.; Rutherford, S. A.; Sedgbeer, J. K.; Thompson, J. C.; White, R.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C. K.; Clarke, D. P.; Ellis, G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Pearson, M. R.; Robertson, N. A.; Sloan, T.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Hölldorfer, F.; Jakobs, K.; Kayser, F.; Müller, A.-S.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Hüttmann, K.; Lütjens, G.; Männer, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Foà, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P. G.; Awunor, O.; Blair, G. A.; Cowan, G.; Garcia-Bellido, A.; Green, M. G.; Medcalf, T.; Misiejuk, A.; Strong, J. A.; Teixeira-Dias, P.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Tomalin, I. R.; Ward, J. J.; Bloch-Devaux, B.; Boumediene, D.; Colas, P.; Fabbro, B.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, B.; Litke, A. M.; Taylor, G.; Booth, C. N.; Cartwright, S.; Combley, F.; Hodgson, P. N.; Lehto, M.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S. R.; Berkelman, K.; Cranmer, K.; Ferguson, D. P. S.; Gao, Y.; González, S.; Hayes, O. J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P. A.; Nielsen, J.; Pan, Y. B.; von Wimmersperg-Toeller, J. H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.; Aleph Collaboration

    2006-08-01

    Deuteron and anti-deuteron production in Z decays has been observed in the ALEPH experiment at LEP. The production rate of anti-deuterons is measured to be (5.9 ± 1.8 ± 0.5) ×10-6 per hadronic Z decay in the anti-deuteron momentum range from 0.62 to 1.03 GeV/c. The coalescence parameter B2, which characterizes the likelihood of anti-deuteron production, is measured to be 0.0033 ± 0.0013 GeV2 in Z decays. These measurements indicate that the production of anti-deuterons is suppressed in e+e- collisions compared to that in pp and photoproduction collisions.

  20. Breakup of finite thickness viscous shell microbubbles by ultrasound: A simplified zero-thickness shell model

    PubMed Central

    Hsiao, Chao-Tsung; Chahine, Georges L.

    2013-01-01

    A simplified three-dimensional (3-D) zero-thickness shell model was developed to recover the non-spherical response of thick-shelled encapsulated microbubbles subjected to ultrasound excitation. The model was validated by comparison with previously developed models and was then used to study the mechanism of bubble break-up during non-spherical deformations resulting from the presence of a nearby rigid boundary. The effects of the shell thickness and the bubble standoff distance from the solid wall on the bubble break-up were studied parametrically for a fixed insonification frequency and amplitude. A diagram of bubble shapes versus the normalized shell thickness and wall standoff was derived, and the potential bubble shapes at break-up from reentrant jets were categorized resulting in four distinct zones. PMID:23556560

  1. Electron-induced deuteron disintegration at threshold

    SciTech Connect

    Bernheim, M.; Jans, E.; Mougey, J.; Royer, D.; Tarnowski, D.; Turck-Chieze, S.; Sick, I.; Capitani, G.P.; De Sanctis, E.; Frullani, S.

    1981-02-09

    Electroexcitation of the singlet S state of the deuteron has been measured for the range of momentum transfer q/sup 2/=6--19 fm/sup -2/ where meson-exchange current contributions dominate the cross section.

  2. The Folding Deuteron Optical Model Potentials

    E-print Network

    Xiaohua Li; Haixia An; Chonghai Cai

    2008-06-04

    For 52 target nuclei with deuteron as projectile, we calculate the reaction cross sections and elastic scattering angular distributions, as well as the $\\chi^2$ values for 11 kinds of deuteron optical model potentials: our global deuteron optical potentials and 10 folding optical potentials calculated with 2 phenomenological global nucleon optical potentials given by Koning \\textit{et al}(KD) and by Varner\\textit{et al}(CH89), and 8 microscopic nucleon optical potentials with the generalized Skyrme force parameters(GS1-6) and modified Skyrme force parameters(SKa, SKb). We find that for constructing the folding deuteron optical potential, both SKa and SKb are the best Skyrme force parameters of the microscopic nucleon optical potential proposed by Q. Shen \\textit{et al}.

  3. Deuteron production in p-Be interactions at 450 GeV/c and the coalescing model NA56 collaboration

    NASA Astrophysics Data System (ADS)

    Bonesini, M.

    2008-05-01

    The analysis of the deuteron production in p-Be interactions at 450 GeV/c taken by the NA56/SPY experiment at CERN SPS is presented. In the framework of the coalescence model, the coalescence factor k is determined as (0.79±0.05±0.13) × 10-2. Our results disfavour the hypothesis that coalescence be the dominant mechanism for deuteron production in p + Be interactions at low pT.

  4. Ice breakup on the Skunk River

    USGS Multimedia Gallery

    This image and associated video captures the breakup of ice cover on the Skunk River at Augusta, Iowa, on February 17, 2011, at approximately 3:00 p.m. local time. The river stage at the time was 14.50 feet (elevation 1,179.41 feet NGVD29). A preliminary estimate of the discharge at the time of the ...

  5. The Spectrum of Satellite Breakup and Fragmentation

    Microsoft Academic Search

    D. Finkleman

    2009-01-01

    The objective of this paper is to expose the spectrum of satellite breakup physics and is implications for debris production and observables. Satellite response to the debris environment generally emphasizes small scale hypervelocity impact or the interaction of intense, coherent radiation with satellite surfaces or internals. There are empirical correlations of fragment size distributions based on arena tests and extremely

  6. On the driving forces of the Pangea breakup and northward drift of the Indian subcontinent

    NASA Astrophysics Data System (ADS)

    Yoshida, Masaki; Hamano, Yozo

    2015-04-01

    During the breakup of the supercontinent Pangea, the Indian subcontinent became isolated from the southern part of Pangea, called Gondwanaland, at around 130 Ma, moved northwards, and eventually collided with Eurasia to form the Himalayas at around 40-50 Ma. The reason why the Indian subcontinent moved at such a high speed of up to c. 20 cm/yr remains a controversial issue in geodynamics. Here, numerical simulation of 3-D spherical mantle convection with an Earth-like Rayleigh number is reported, considering the assembly of highly viscous continental blocks with the configuration of Pangea, to determine the geodynamic mechanisms of the Pangea breakup, the subsequent continental drift, and the high-speed northward drift of the Indian subcontinent. Our numerical simulations approximately reproduced the process of continental drift from the breakup of Pangea at 200 Ma to the present-day continental distribution. These simulations revealed that a major factor in the northward drift of the Indian subcontinent was the large-scale cold mantle downwelling that developed spontaneously in the North Tethys Ocean, attributed to the overall shape of Pangea. The strong lateral mantle flow caused by the high-temperature anomaly beneath Pangea, due to the thermal insulation effect, enhanced the acceleration of the Indian subcontinent during the early stage of the Pangea breakup. The large-scale hot upwelling plumes from the lower mantle, initially located under Africa, might have contributed to the formation of the large-scale cold mantle downwelling in the North Tethys Ocean. References: [1] Yoshida, M., Effects of various lithospheric yield stresses and different mantle-heating modes on the breakup of the Pangea supercontinent, Geophys. Res. Lett., 41(9), 3060-3067, doi:10.1002/2014GL060023, 2014. [2] Yoshida, M. and Y. Hamano, Pangea breakup and northward drift of the Indian subcontinent reproduced by a numerical model of mantle convection, Submitted to Scientific Reports, 2015. (in revision)

  7. Deuteron Elastic-Scattering at 110 and 120 Mev 

    E-print Network

    Betker, A. C.; Gagliardi, Carl A.; Semon, D. R.; Tribble, Robert E.; Xu, HM; Zaruba, A. F.

    1993-01-01

    Deuteron elastic scattering cross sections have been measured at 110 and 120 MeV on C, Ni-58, and Pb-208. Optical model potentials have been extracted and compared to deuteron global optical model potentials....

  8. Coupled map lattice model of jet breakup

    SciTech Connect

    Minich, R W; Schwartz, A J; Baker, E L

    2001-01-25

    An alternative approach is described to evaluate the statistical nature of the breakup of shaped charge liners. Experimental data from ductile and brittle copper jets are analyzed in terms of velocity gradient, deviation of {Delta}V from linearity, R/S analysis, and the Hurst exponent within the coupled map lattice model. One-dimensional simulations containing 600 zones of equal mass and using distinctly different force-displacement curves are generated to simulate ductile and brittle behavior. A particle separates from the stretching jet when an element of material reaches the failure criterion. A simple model of a stretching rod using brittle, semi-brittle, and ductile force-displacement curves is in agreement with the experimental results for the Hurst exponent and the phase portraits and indicates that breakup is a correlated phenomenon.

  9. SINGLE BUNCH BEAM BREAKUP - A GENERAL SOLUTION

    Microsoft Academic Search

    Jiunn-Ming Wang; S. R. MANE; Nathan Towne

    2000-01-01

    Caporaso, Barletta and Neil (CBN) found in a solution to the problem of the single-bunch beam breakup in a linac[1]. However, their method applies only to the case of a beam traveling in a strongly betatron-focused linac under the influence of the resistive wall impedance. We suggest in this paper a method for dealing with the same problem. Our methods

  10. Prospects for Acceleration of Deuterons and Helions

    SciTech Connect

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

    2008-02-06

    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.

  11. Numerical Study of Drop Interface Deformation and Breakup in Shear Flow

    NASA Astrophysics Data System (ADS)

    Lin, C. Z.; Guo, L. J.; Han, X. X.

    2010-03-01

    This paper presents numerical simulation results of the deformation and breakup of an isolated liquid drop suspended in an ambient, immiscible viscous fluid under shear flow. The model predicting the dynamic behavior of the drop is based on a diffuse interface method. The interface between the two fluids is tracked by an order parameter, namely the mass concentration. The fully transient, three dimensional Navier-Stokes equations for an incompressible fluid are solved by a projection method on a fixed Cartesian grid which the interface moves through to ensure accurate calculation of the surface evolution. Surface tension effects are incorporated into the model through a modified stress. This paper focuses on steady shape analysis and the end pinching mechanism of drop breakup. The numerical results of drop deformation and breakup show very good agreement with theoretical analysis and experimental observations, which indicate that the diffuse interface method can successfully capture the main behavior of the drop deformation and breakup Detailed instructions for typing your article are given in the following.

  12. A discussion of deuteron transverse charge densities

    E-print Network

    Cuiying Liang; Yubing Dong; Weihong Liang

    2014-08-27

    The deuteron transverse charge density $\\rho_C(b)$ is the two-dimensional Fourier transform of its charge form factor in the impact space. We show that different parameterizations of the charge form factors provide different $\\rho_C(b)$, in particular at the central value of impact parameter ($b=0$), although all the parameterizations can well reproduce the form factors in the region of small $Q^2$. In addition, we also check the explicit contributions from the different coordinate intervals of the deuteron wave function to its root-mean-square radius.

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

    Zhu, Chengxiang; Ertl, Moritz; Weigand, Bernhard

    2013-08-01

    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.

  15. The Break-up and Drifting of the Continental Plates in 2D Models of Convecting Mantle

    NASA Astrophysics Data System (ADS)

    Dal Zilio, L.; Faccenda, M.; Capitanio, F. A.

    2014-12-01

    Since the early theory of Wegener, the break-up and drift of continents have been controversial and hotly debated topics. To assist the interpretation of the break-up and drift mechanisms and its relation with mantle circulation patterns, we carried out a 2D numerical modelling of the dynamics of these processes. Different regimes of upper plate deformation are studied as consequence of stress coupling with convection patterns. Subduction of the oceanic plate and induced mantle flow propagate basal tractions to the upper plate. This mantle drag forces (FMD) can be subdivided in two types: (1) active mantle drag occurring when the flow drives plate motion (FAD), and (2) passive mantle drag (FPD), when the asthenosphere resists plate motion. The active traction generated by the convective cell is counterbalanced by passive mantle viscous drag away from it and therefore tension is generated within the continental plate. The shear stress profiles indicate that break-up conditions are met where the gradient of the basal shear stress is maximised, however the break-up location varies largely depending on the convection style primarily controlled by slab stagnation on the transition zone, avalanching through or subduction in the lower mantle. We found good correspondence between our models and the evolution of convergent margins on Earth, giving precious insights into the break-up and drifting mechanisms of some continental plates, such as the North and South American plates, Calabria and the Japan Arc.

  16. Modeling mud flocculation using variable collision and breakup efficiencies

    NASA Astrophysics Data System (ADS)

    Strom, K.; Keyvani, A.

    2013-12-01

    Solution of the Winterwerp (1998) floc growth and breakup equation yields time dependent median floc size as an outcome of collision driven floc growth and shear induced floc breakage. The formulation is quite nice in that it is an ODE that yields fast solution for median floc size and can be incorporated into sediment transport models. The Winterwerp (1998) floc size equation was used to model floc growth and breakup data from laboratory experiments conducted under both constant and variable turbulent shear rate (Keyvani 2013). The data showed that floc growth rate starts out very high and then reduces with size to asymptotically approach an equilibrium size. In modeling the data, the Winterwerp (1998) model and the Son and Hsu (2008) variant were found to be able to capture the initial fast growth phase and the equilibrium state, but were not able to well capture the slow growing phase. This resulted in flocs reaching the equilibrium state in the models much faster than the experimental data. The objective of this work was to improve the ability of the general Winterwerp (1998) formulation to better capture the slow growth phase and more accurately predict the time to equilibrium. To do this, a full parameter sensitivity analysis was conducted using the Winterwerp (1998) model. Several modifications were tested, including the variable fractal dimension and yield strength extensions of Son and Hsu (2008, 2009). The best match with the in-house data, and data from the literature, was achieved using floc collision and breakup efficiency coefficients that decrease with floc size. The net result of the decrease in both of these coefficients is that floc growth slows without modification to the equilibrium size. Inclusion of these new functions allows for substantial improvement in modeling the growth phase of flocs in both steady and variable turbulence conditions. The improvement is particularly noticeable when modeling continual growth in a decaying turbulence field similar to what might be experienced in a river mouth jet. Inclusion of the functions does, however, result in problems with capturing rapid floc breakage due to a stepwise increase in turbulent shear. References Keyvani, A. (2013). Flocculation processes in river mouth fluvial to marine transitions. Ph.D. dissertation, University of Houston. Son, M. & Hsu, T.J. (2008). Flocculation model of cohesive sediment using variable fractal dimension. Environmental Fluid Mechanics, 8(1), 55-71. Son, M. & Hsu, T.J. (2009). The effect of variable yield strength and variable fractal dimension on flocculation of cohesive sediment. Water Research, 43(14), 3582 - 3592. Winterwerp, J. C. (1998). A simple model for turbulence induced flocculation of cohesive sediment. Journal of Hydraulic Research, 36(3), 309-326.

  17. Pangea formation and break-up

    NASA Astrophysics Data System (ADS)

    Torsvik, Trond

    2013-04-01

    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.

  18. SINGLE BUNCH BEAM BREAKUP - A GENERAL SOLUTION.

    SciTech Connect

    WANG,J.M.; MANE,S.R.; TOWNE,N.

    2000-06-26

    Caporaso, Barletta and Neil (CBN) found in a solution to the problem of the single-bunch beam breakup in a linac[1]. However, their method applies only to the case of a beam traveling in a strongly betatron-focused linac under the influence of the resistive wall impedance. We suggest in this paper a method for dealing with the same problem. Our methods is more general; it applies to the same problem under any impedance, and it applies to a linac with or without external betatron focusing.

  19. Polar lake circulation during ice break-up

    NASA Astrophysics Data System (ADS)

    Kirillin, Georgiy; Forrest, Alexander; Graves, Kelly; Laval, Bernard

    2014-05-01

    An extensive dataset on lake physical properties has been collected during the final stage of the ice-covered period in May-June 2013 in polar Lake Kilpisjärvi, Finland. The data reveal several important features of lake dynamics, which shed new light on the mechanism of ice cover break-up and ice melting in lakes and marginal seas. CTD transects with high spatial resolution showed up a 300m-wide upwelling zone in the center of the lake, driven by downslope converging flow of warm waters from open-water 'moat' along the lake shoreline. The resulting radial density gradient, balanced by the Coriolis force, created a lake-wide anti-cyclonically rotating gyre with a measured peak azimuthal velocity of 0.05 m/s. Appreciable marginal heating is driven in polar enclosed basins by high amount of solar radiation and by surface inflow of meltwater. Hence, quasi-geostrophic anticyclonic circulation is suggested to be a general feature of polar lakes, redistributing heat within a water body and potentially accelerating ice melting. In addition, high-resolution records of pressure, current velocities and water temperature revealed under-ice seiches with periods of 10 to 25 min. The ice breakup was associated with 10 times increase of seiche amplitudes under ice. The seiches decayed within 10-15 hours; during this short period, the previously ice-covered lake became ice-free. We suggest that seiche-driven vertical motions of the soft ice sheet contribute significantly to breaking and melting of seasonal ice in enclosed reservoirs.

  20. LES of atomizing spray with stochastic modeling of secondary breakup

    E-print Network

    Apte, Sourabh V.

    deterministic breakup models based on Taylor analogy breakup (TAB) (OÕRourke and Amsden, 1987) or wave (Reitz on the liquid phase. In the TAB model (OÕRourke and Amsden, 1987), oscillations of the parent droplet-scaleÕ production of new droplets. In many combustion applications, however, injection of liquid jet takes place

  1. Modeling of Turbulence Effects on Liquid Jet Atomization and Breakup

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Chen, C. P.

    2005-01-01

    Recent experimental investigations and physical modeling studies have indicated that turbulence behaviors within a liquid jet have considerable effects on the atomization process. This study aims to model the turbulence effect in the atomization process of a cylindrical liquid jet. Two widely used models, the Kelvin-Helmholtz (KH) instability of Reitz (blob model) and the Taylor-Analogy-Breakup (TAB) secondary droplet breakup by O Rourke et al, are further extended to include turbulence effects. In the primary breakup model, the level of the turbulence effect on the liquid breakup depends on the characteristic scales and the initial flow conditions. For the secondary breakup, an additional turbulence force acted on parent drops is modeled and integrated into the TAB governing equation. The drop size formed from this breakup regime is estimated based on the energy balance before and after the breakup occurrence. This paper describes theoretical development of the current models, called "T-blob" and "T-TAB", for primary and secondary breakup respectivety. Several assessment studies are also presented in this paper.

  2. Long term orbital debris environment sensitivity to spacecraft breakup parameters

    Microsoft Academic Search

    Al Reinhardt; William Borer; Kenneth Yates

    1993-01-01

    The long term prediction of the orbital debris environment depends fundamentally on the dynamics of spacecraft breakups. These processes provide the numbers, initial velocities, positions, and ballistic coefficients for newly formed debris fragments. Efforts are ongoing to model satellite breakup phenomenon using a variety of models with varying degrees of complexity. This paper provides a comparison of four of the

  3. 24 CFR 982.315 - Family break-up.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 false Family break-up. 982.315 Section 982.315 Housing...Leasing a Unit § 982.315 Family break-up. (a)(1) The PHA has discretion...assistance in the program if the family breaks up. The PHA administrative plan must...

  4. 24 CFR 982.315 - Family break-up.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 false Family break-up. 982.315 Section 982.315 Housing...Leasing a Unit § 982.315 Family break-up. (a)(1) The PHA has discretion...assistance in the program if the family breaks up. The PHA administrative plan must...

  5. 24 CFR 982.315 - Family break-up.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Family break-up. 982.315 Section 982.315 Housing...Leasing a Unit § 982.315 Family break-up. (a)(1) The PHA has discretion...assistance in the program if the family breaks up. The PHA administrative plan must...

  6. 24 CFR 982.315 - Family break-up.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Family break-up. 982.315 Section 982.315 Housing...Leasing a Unit § 982.315 Family break-up. (a)(1) The PHA has discretion...assistance in the program if the family breaks up. The PHA administrative plan must...

  7. Fractofusion Mechanism

    Microsoft Academic Search

    Tatsuoki Takeda; Tomonori Takizuka

    1989-01-01

    With respect to cold fusion, a fractofusion mechanism is investigated. Deuterons are accelerated by the electric field generated between crack surfaces in a crystal. By assuming the possible magnitude of the potential difference, we calculate the fusion rate and energy multiplication factor. The results are consistent with those of the cold fusion experiments, and the fractofusion mechanism can explain the

  8. Sikuliqiruq: Ice dynamics of the Meade river - Arctic Alaska, from freezeup to breakup from time-series ground imagery

    USGS Publications Warehouse

    Beck, R.A.; Rettig, A.J.; Ivenso, C.; Eisner, Wendy R.; Hinkel, Kenneth M.; Jones, Benjamin M.; Arp, C.D.; Grosse, G.; Whiteman, D.

    2010-01-01

    Ice formation and breakup on Arctic rivers strongly influence river flow, sedimentation, river ecology, winter travel, and subsistence fishing and hunting by Alaskan Natives. We use time-series ground imagery ofthe Meade River to examine the process at high temporal and spatial resolution. Freezeup from complete liquid cover to complete ice cover ofthe Meade River at Atqasuk, Alaska in the fall of 2008 occurred in less than three days between 28 September and 2 October 2008. Breakup in 2009 occurred in less than two hours between 23:47 UTC on 23 May 2009 and 01:27 UTC on 24 May 2009. All times in UTC. Breakup in 2009 and 2010 was ofthe thermal style in contrast to the mechanical style observed in 1966 and is consistent with a warming Arctic. ?? 2010 Taylor & Francis.

  9. New Candidates for Recent Asteroid Breakups

    NASA Astrophysics Data System (ADS)

    Nesvorný, D.; Vokrouhlický, D.

    2006-11-01

    Asteroids in our solar system formed in a dynamically quiescent disk, but their orbits became gravitationally stirred enough by Jupiter to lead to high-speed collisions. As a result, several dozen large asteroids have been disrupted by impacts over the past several gigayears and have produced groups of fragments called asteroid families. Here we report three new candidates for asteroid families that were formed by collisions occurring in the last 1 Myr. According to our modeling of the past orbital histories of known cluster members, we estimate that the Emilkowalski, 1992 YC2, and Lucascavin clusters are 220+/-30, 50-250, and 300-800 kyr old, respectively. Together with the previously identified Datura cluster, estimated to be 450+/-50 kyr old, they are the most recent asteroid breakups ever discovered in the main belt. Astronomical observations of identified family members can be used to better understand impact physics, asteroid composition, and surface-aging processes. Discovered breakups may also be important sources of interplanetary dust.

  10. Volcanic Versus Non-Volcanic Passive Margins: Two Different Ways to Break-up Continents

    NASA Astrophysics Data System (ADS)

    Geoffroy, L.; Burov, E. B.; Werner, P.; Unternehr, P.

    2014-12-01

    Volcanic passive margins (VPMs) are distinctive features of Larges Igneous Provinces. They characterize continental breakup associated with the extrusion and intrusion of large volumes of magma, predominantly mafic. In Large Igneous Provinces, regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere, suggesting that mantle melting is a cause of continental break-up, not a consequence. Early melt covers as volcanic traps large cratonic or/and cratonic-edge continental areas. Crustal dilatation through dyking in the upper crust and magma underplating at Moho level is thought to occur massively during this early stage. Lithosphere extension leading to break-up and VPMs development is coeval with a 3D focusing of mantle melting, giving rise to VPMs. From a combination of deep seismic reflection profiles and onshore observations, we show that the mechanism of continental breakup at volcanic passive margins is very different from the one generally proposed for non-magmatic systems. Crustal extension and coeval extrusion of thick wedges of seaward-dipping basalts are accommodated by continentward-dipping detachment-faults at both conjugate margins. Those faults root on a deformed ductile crust whose composition seems partly magmatic. Our numerical modeling show that hardening of deep continental crust during the early magmatic stages provokes a divergent flow of the ductile lithosphere (mantle and lower crust) away from a central continental block which thins through advection with time. Magma-assisted crustal-scale faults dipping continentward root over this flowing material, isolating micro-continents which may be lost in the future oceanic domain. The structure and tectonic evolution of volcanic passive margins cannot therefore be compared to non-volcanic ones, where major detachment faults dip oceanward during the necking-stage and where mantle is finally exhumed during the mechanical breakup. Confusions may exist where ancient hyper-extended rift systems parallel VPMs. In such cases, VPMs develop within a continental lithosphere made harder by previous crust thinning and lithosphere thermal relaxation.

  11. Thermonuclear breakup reactions of light nuclei. I - Processes and effects. [in astrophysic plasmas

    NASA Technical Reports Server (NTRS)

    Guessoum, Nidhal; Gould, Robert J.

    1989-01-01

    Temperature and density conditions are considered for the occurrence of breakup reactions of light nuclei in astrophysical plasmas. The proton-induced endothermic process is shown to be the principal mechanism for nuclear breakdown in a plasma. The phenomenon occurs at a temperature of about 1 MeV, which is a fraction of the typical binding energy per nucleon in nuclei. The temperature for breakup of He-4 is about twice as large, because of the higher binding energy. Depending on the temperature attained in the plasma, the initial concentration of elements heavier than hydrogen can be depleted. However, if it attains a temperature of about 1 MeV, breaking up the metals (C, N, O, Ne, Mg) but not He-4, an increase in the He-4 abundance by as much as 10 percent can result, since these elements essentially break down to alpha particles.

  12. Quark correlations and deuteron electromagnetic form factors

    SciTech Connect

    Robson, D. [Florida State University, Tallahassee, Florida 32306 (United States)] [Florida State University, Tallahassee, Florida 32306 (United States)

    2000-01-01

    The recent preliminary values of A(Q{sup 2}) and t{sub 20}(70 degree sign ) elastic electron-scattering data extracted from deuterium at larger values of Q{sup 2} have placed more stringent constraints on models of the nucleon-nucleon system. Comparisons of the data with conventional hadronic models and with perturbative QCD have been made, and are strongly in favor of the hadronic picture provided isoscalar meson exchange currents are included. In this work a nonperturbative quark model of the deuteron with parameters determined from earlier work is used to investigate the role of quark correlations in describing the deuteron electromagnetic form factors. The results give a good description of the recent data and show that this model with many-body confinement has quark correlation contributions to the charge form factors which are remarkably similar to the meson exchange current contributions. (c) 1999 The American Physical Society.

  13. An Empirically Based Shaped Charge Jet Break-Up Model

    NASA Astrophysics Data System (ADS)

    Baker, Ernest; Pham, James; Vuong, Tan

    2013-06-01

    This paper discusses an empirically based shaped charge jet break-up model based around Walsh's breakup theory and provides significant experimental confirmation over a broad range of velocity gradients. The parameters which affect jet length and breakup times are fairly well known, but there is some controversy over the exact nature of the dependencies. Walsh theorized that the dependence of jet length would take a particular form, based on his determination of a dimensionless parameter for the problem and numerical experiments in which initial perturbation strengths were varied. Walsh did not present comparisons with experimental results. Chou has presented a variety of different jet break-up models with some data comparisons. Mostert [3] has suggested that breakup time is proportional to (?m/?v) 1/3. It is shown here that the parameter (?m/?v)1/2 or (dm/dv)1/3, closely related to Walsh's dimensionless parameter, whose values were obtained from either experiments or simulations correlates quite well with jet breakup times for a very wide variety of shaped charge devices. The values of ?m and ?v are respectively the jet mass and the velocity difference of the portion of jet in question. For a typical shaped charge ?m/?v is essentially invariant with respect to time. In this paper, we present the mathematical basis for an empirically based break-up model with a similar basis to Walsh and Mostert, as well as supporting empirical data for a broad range of shaped charge geometries.

  14. Shadowing in multiparton proton - deuteron collisions

    E-print Network

    B. Blok; M. Strikman

    2014-08-07

    We study the screening effect for the multiparton interactions (MPI) for proton--deuteron collisions in the kinematics where one parton belonging to the deuteron has small $x_1$ so the leading twist shadowing is present while the second parton ($x_2$) is involved in the interaction %%ms in the kinematics where shadowing effects are small. We find that the ratio of the shadowing and the impulse approximation terms is approximately factor of two larger for MPI than for the single parton distributions. We also calculate the double parton antishadowing (DPA) contribution to the cross section due to the independent interactions of the partons ofthe projectile proton with two nucleons of the deuteron and find that shadowing leads to a strong reduction ofthe DPA effect.For example, for the resolution scale $Q_1^2 \\sim 4$~$\\mbox{GeV}^2$ of the interaction with parton $x_1$ we find that shadowing reduces the DPA effect by $\\sim$ 30%. It is argued that in the discussed kinematics the contribution of interference diagrams, which correspond to the interchange ofpartonsbetween the proton and neutron, constitutes only a small correction to the shadowing contributions.

  15. Shadowing in multiparton proton-deuteron collisions

    NASA Astrophysics Data System (ADS)

    Blok, B.; Strikman, M.

    2014-09-01

    We study the screening effect for the multiparton interactions (MPI) for proton--deuteron collisions in the kinematics where one parton belonging to the deuteron has small $x_1$ so the leading twist shadowing is present while the second parton ($x_2$) is involved in the interaction %%ms in the kinematics where shadowing effects are small. We find that the ratio of the shadowing and the impulse approximation terms is approximately factor of two larger for MPI than for the single parton distributions. We also calculate the double parton antishadowing (DPA) contribution to the cross section due to the independent interactions of the partons ofthe projectile proton with two nucleons of the deuteron and find that shadowing leads to a strong reduction ofthe DPA effect.For example, for the resolution scale $Q_1^2 \\sim 4$~$\\mbox{GeV}^2$ of the interaction with parton $x_1$ we find that shadowing reduces the DPA effect by $\\sim$ 30%. It is argued that in the discussed kinematics the contribution of interference diagrams, which correspond to the interchange ofpartonsbetween the proton and neutron, constitutes only a small correction to the shadowing contributions.

  16. Deuteron-Proton Elastic Scattering at Intermediate Energies

    E-print Network

    N. B. Ladygina

    2007-05-22

    The deuteron-proton elastic scattering has been studied in the multiple scattering expansion formalism. The essential attention has been given to such relativistic problem as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parameterization of the nucleon-nucleon $t$-matrix has been used to take the off-energy shell effects into account. The vector, $A_y,$ and tensor, $A_{yy}$, analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 MeV and 1200 MeV. The obtained results are compared with the experimental data.

  17. Deuteron-proton elastic scattering at intermediate energies

    SciTech Connect

    Ladygina, N. B., E-mail: nladygina@jinr.r [Joint Institute for Nuclear Research (Russian Federation)

    2008-12-15

    The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon-nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A{sub y}, and tensor, A{sub yy}, analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data.

  18. Deuteron-proton elastic scattering at intermediate energies

    NASA Astrophysics Data System (ADS)

    Ladygina, N. B.

    2008-12-01

    The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon—nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A y , and tensor, A yy , analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data.

  19. Impacts, tillites, and the breakup of Gondwanaland

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.; Marshall, John R.; Aggarwal, Hans

    1993-01-01

    Mathematical analysis demonstrates that substantial impact crater deposits should have been produced during the last 2 Gy of Earth's history. Textures of impact deposits are shown to resemble textures of tillites and diamictites of Precambrian and younger ages. The calculated thickness distribution for impact crater deposits produced during 2 Gy is similar to that of tillites and diamictites of 2 Ga or younger. We suggest, therefore, that some tillites/diamictites could be of impact origin. Extensive tillite/diamictite deposits predated continental flood basalts on the interior of Gondwanaland. Significantly, other investigators have already associated impact cratering with flood basalt volcanism and continental rifting. Thus, it is proposed that the breakup of Gondwanaland could have been initiated by crustal fracturing from impacts.

  20. The Mesozoic breakup of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    KöNig, Matthias; Jokat, Wilfried

    2006-12-01

    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).

  1. Self-similar Breakup of Near-inviscid Fluids

    E-print Network

    Castrejon-Pita, J.R.; Castrejon-Pita, A.A.; Hinch, E.J.; Lister, J.R.; Hutchings, I.M.

    2012-01-01

    Castrejon-Pita, J.R., Castrejon-Pita, A.A., Hinch, E.J., Lister, J.R., Hutchings, I.M., Physical Review (in press 2012) 'Self-similar Breakup of Near-inviscid Fluids' Self-similar Breakup of Near-inviscid Fluids J.R. Castrejo´n-Pita, A.A. Castrejo... 3 9EW, U.K. The final stages of pinchoff and breakup of dripping droplets of near-inviscid Newtonian fluids are studied experimentally for pure water and ethanol. High speed imaging and image analysis are used to determine the angle and the minimum...

  2. New description of four-body break-up reaction

    SciTech Connect

    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

    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.

  3. Multibunch beam break-up in detuned structures

    SciTech Connect

    Thompson, K.A.; Adolphsen, C.; Bane, K.L.F.

    1993-05-01

    A key problem in next-generation linear collider design utilizing multibunching is the control of multibunch beam break-up. One method of controlling the break-up is detuning, i.e., varying the frequency of the transverse deflecting modes by varying the cell dimensions within the accelerating structures. In this case, the beam breakup is sensitive to the resonances between the bunch frequency and some of the deflecting mode frequencies. It is also sensitive to errors in the fabrication and alignment of the accelerating structures. We examine these effects in the context of the SLAC NLC design.

  4. Study on the cylindrical liquid nanojet break-up phenomenon

    NASA Astrophysics Data System (ADS)

    Zhao, Jianbo

    2015-04-01

    In this paper the liquid argon nanojet break-up phenomenon was studied using the molecular dynamics method. The effects of temperature, nozzle diameter and body force on the nanojet break-up length and time were simulated. Meanwhile, the particle size, wave length and the frequency of the disturbance were compared with the results of linear stability analysis. The results showed that even though the fluid becomes discontinuous, the traditional linear stability analysis can be used to make a rough calculation of the nanojet break-up.

  5. The TAB method for numerical calculation of spray droplet breakup

    SciTech Connect

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

    1987-01-01

    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. We 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.

  6. Signatures of Pseudo-breakup, Breakup of a Full Substorm Onset, and Poleward Border Intensifications Compared.

    NASA Astrophysics Data System (ADS)

    Voronkov, I.; Donovan, E. F.; Samson, J. C.

    2001-12-01

    For several exceptional events, we use ground-based and in-situ data to compare the ionospheric, geostationary, and mid-tail signatures of the pseudo-breakup, breakup, and poleward border intensifications (PBIs). In doing so, we utilize CANOPUS magnetometer and multi-wavelength photometer and All-sky imager data, as well as field measurements provided by the GOES 8, GOES 9, and Geotail spacecraft. We have identified a set of distinguishable signatures of each process. Pseudo-breakup consists of two distinct stages: near-linear arc intensification corresponding to the ``explosive growth phase" at geostationary orbit, and poleward vortex expansion that starts simultaneously with explosive onset of short period pulsations (Pi1, Pi2) and dipolarization observed at geostationary orbit. It can be accompanied by local perturbations of the equatorward part of the electron precipitation region and by formation of the substorm-like local current system but neither by optical signatures of the lobe flux reconnection nor by perturbations in the mid-tail. It typically saturates near the equatorward border of the electron precipitation region producing a mushroom-like auroral structure. Breakup starts with the same two-stage initial scenario of the arc intensification and vortex evolution but it rapidly expands poleward and is accompanied by optical signatures of reconnection onset, namely the aurora develops into a cell-like structure of the size compatible with the whole auroral zone width. This occurs at the time when mid-tail disruption signatures are observed. Full onset launches a second, more global, larger Pi2 burst. Finally, we show an example of PBIs observed as long period pulses of electron precipitation at the poleward border of auroral region, followed by the high-latitude proton aurora. The commencement of PBI coincided with bursty bulk flows and pulses of plasma energization in the mid-tail. Observed features are discussed with respect to recent ideas claiming that we are dealing with processes (breakup, full onset, and PBI) of distinct physical nature that require different conditions and thresholds for their commencement.

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

    SciTech Connect

    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

    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.

  8. 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)

    Buiter, Susanne; Torsvik, Trond

    2013-04-01

    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)

  9. Liquid jet breakup characterization with application to melt-water mixing

    SciTech Connect

    Ginsberg, T.

    1986-01-01

    Severe accidents in light-water reactors could lead to the flow of molten core material from the initial core region of the reactor vessel to the lower plenum. Steam explosions have been predicted to occur as a result of the contact of the melt with water available in the plenum. It is presently judged by many workers, that the magnitude of the energy released during such an in-vessel explosion would be insufficient to lead to failure of the containment building (SERG, 1985). A major contributing factor in this judgment is that the mass of melt which would participate in the interaction would be limited by the quantity of melt delivered to the lower plenum to the time of the explosion and by the limited breakup of the molten pour stream as it flows through the plenum prior to the explosion. Limited pour stream breakup would lead to limited melt-water mixing and, in addition, to the existence of ''large-scale'' melt masses which may lead to very inefficient thermal-to-mechanical energy conversion. The objective of this paper is to assess the available literature relevant to liquid jet breakup and to assess its implications with respect to the behavior of molten corium pour streams as they would flow from the core region through the lower plenum. Uncertainties in application of the available literature are discussed. 7 refs., 2 figs.

  10. Break-ups Before Marriage: The End of 103 Affairs

    ERIC Educational Resources Information Center

    Hill, Charles T.; And Others

    1976-01-01

    Factors that predicted breakups before marriage, investigated as part of a two-year study of dating relationships among college students include unequal involvement in the relationship and discrepant age, educational aspirations, intelligence, and physical attractiveness. (Author/AM)

  11. [MRO] Capillary Breakup of Discontinuously Rate Thickening Suspensions

    E-print Network

    McKinley, Gareth H.

    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 ...

  12. New description of the four-body breakup reaction

    SciTech Connect

    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

    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.

  13. Coincident UVI and Wind Observations of Pseudo-Breakups

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Brittnacher, M.; Parks, G. K.; Germany, G. A.; Spann, J. F.; Lin, R. P.

    1998-01-01

    Using images taken by the Ultraviolet Imager (UVI) onboard the Polar spacecraft, we identify periods of pseudo-breakup activity coincident with perigee passes of the WIND spacecraft through the magnetotail. Previous studies have shown that from both observations on the ground and in the magnetotail there is very little difference phenomenologically between substorm onset and pseudo-breakups except for the degree of localization and the absence of global expansion. This raises the question of what prevents a pseudo-breakup from expanding globally. For the time intervals studied, we find a high correlation between pseudo-breakups and short-lived particle flux enhancements in the magnetotail. The velocity distribution of the plasma during some of these flux enhancements are indicative of bursty bulk flows.

  14. The Spectrum of Satellite Breakup and Fragmentation

    NASA Astrophysics Data System (ADS)

    Finkleman, D.

    The objective of this paper is to expose the spectrum of satellite breakup physics and is implications for debris production and observables. Satellite response to the debris environment generally emphasizes small scale hypervelocity impact or the interaction of intense, coherent radiation with satellite surfaces or internals. There are empirical correlations of fragment size distributions based on arena tests and extremely rare observations of breakups in space. Klinkrad describes well research on material response to hypervelocity impact such as the ballistic limit for various materials and shielding walls. Smirnov, et. al., report well the phenomenology of breakups under the influence of nonuniform internal loading of monolithic bodies, such as pressurized tanks. They set forth the transformation of elastic energy into fragment kinetic energy. They establish a sound physical framework for bounding the number of fragments. We took advantage of these works in our previous papers. There is not much research into the response of nonuniform structures to hypervelocity collisions with similarly massive and complex objects. This work generally employs complex hydrodynamic and finite element computation that is not well suited to real time, operational assessment of the consequences of such encounters. We hope to diminish the void between the extremes of microscopic impact and complex hydrocodes. Our previous reports employed the framework established by Chobotov and Spencer, fundamentally equilibrium, Newtonian approach. We now explore the spectrum of interactions and debris evolutions possible with realistic combinations of these theories. The spectrum encompasses Newtonian, semi-elastic energy and momentum transfer through little or no momentum exchange and from virtually all of the mass of the colliders being involved through fractional mass involvement. We observe that the more Newtonian outcomes do not agree well with sparse observations of the few collisions that have occurred in space at high relative velocities. High speed images of collisions such as the Delta 183 intercept reveal that the objects appear to pass through each other, emerging as a collection of fragments that then disperse with diverse particular velocities under the influence of gravitation and other astrodynamic forces. We previously introduced the concept of partial involvement in which the portions of the colliders that do not make intimate contact tear off, retaining their parent momenta and subsequently fragmenting as elastic energy is released. We now conjecture that the duration of the collision is so short (fractional milliseconds) that stress waves cannot propagate within the involved portions either, and that the involved masses fragment inertially, each fragment inheriting the velocity of the parent object rather than the involved masses evolving about the vector sum of collider parent masses. We call this ghosting. We also observe that ghosted outcomes appear in aggregate to match much more closely observed outcomes, particularly that of the recent Iridium 33 Cosmos 2251 event. We will discuss the range of outcomes we predict over the spectrum of interaction and fragmentation models. We will examine how the range of outcomes might affect fragment size, mass, and trajectory evolution, with implications for what might be observable and where the less observable fragments might reside.

  15. A new model for auroral breakup during substorms

    SciTech Connect

    Rothwell, P.L.; Block, L.P.; Falthammar, C.G.; Silevitch, M.B.

    1989-04-01

    A model for substorm breakup is developed, based on the relaxation of stretched (closed) dipolar field lines, and the formation of an incipient current wedge within a single arc structure. It is argued that the establishment of a coupled current structure within a single arc leads to a quasi-stable system; i.e., the pre-breakup regime. Perturbation of the pre-breakup structure leads to an instability criterion. It is found, consistent with observations, that narrower auroral arcs at lower L shells undergo the most explosive poleward expansion. According to this model, the precise location at which breakup occurs depends on the O/sup +/ density in the plasma sheet, the level of magnetic activity (K/sub p/), and the intensity of the substorm westward electrojet in the ionosphere. An enhancement of any of these features will cause breakup to occur at lower L shells. Comparison of our model with the Heppner-Maynard polar-cap potential model indicates that breakup is restricted to the west of the Harang discontinuity consistent with recent observations from the Viking satellite.

  16. Jet impingement and thin film breakup on a superhydrophobic surface

    NASA Astrophysics Data System (ADS)

    Crockett, Julie; Prince, Joseph; Maynes, Daniel

    2013-11-01

    A vertical laminar jet impinging on a horizontal surface spreads out in a thin film on the surface. If the surface is hydrophobic, and a downstream depth is not maintained the film will breakup into droplets. This occurs where the jet's outward radial momentum is balanced by the inward surface tension force of the advancing film. An analytical model has been created to estimate this location. All surfaces explored are hydrophobic or superhydrophobic (SH), where the SH surfaces exhibit an apparent slip at the surface. For SH surfaces with random micropatterning, the slip on the surface is uniform in all directions and droplet breakup occurs in a circular pattern. When alternating rib/cavity microstructures are used to create a SH surface the slip varies as a function azimuth resulting in an elliptically shaped breakup. The location of breakup for multiple surfaces over a range of jet Weber numbers and realistic slip length values is determined. Results show the breakup radius increases with increasing Weber number and slip length. The eccentricity of the breakup ellipse for the rib/cavity SH structures increases with increasing Weber number and slip length as well. The model results compare well to experimental measurements.

  17. Effect of gas mass flux on cryogenic liquid jet breakup

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1992-01-01

    A scattered-light scanning instrument developed at NASA Lewis Research Center was used to measure the characteristic drop size of clouds of liquid nitrogen droplets. The instrument was calibrated with suspensions of monosized polystyrene spheres. In this investigation of the mechanism of liquid nitrogen jet disintegration in a high-velocity gas flow, the Sauter mean diameter, D32, was found to vary inversely with the nitrogen gas mass flux raised to the power 1.33. Values of D32 varied from 5 to 25 microns and the mass flux exponent of 1.33 agrees well with theory for liquid jet breakup in high-velocity gas flows. The loss of very small droplets due to the high vaporization rate of liquid nitrogen was avoided by sampling the spray very close to the atomizer, i.e., 1.3 cm downstream of the nozzle orifice. The presence of high velocity and thermal gradients in the gas phase also made sampling of the particles difficult. As a result, it was necessary to correct the measurements for background noise produced by both highly turbulent gas flows and thermally induced density gradients in the gas phase.

  18. Modeling of Turbulence Effects on Liquid Jet Atomization and Breakup

    NASA Technical Reports Server (NTRS)

    Trinh, Huu; Chen, C. P.

    2004-01-01

    Recent experimental investigations and physical modeling studies have indicated that turbulence behaviors within a liquid jet have considerable effects on the atomization process. For certain flow regimes, it has been observed that the liquid jet surface is highly turbulent. This turbulence characteristic plays a key role on the breakup of the liquid jet near to the injector exit. Other experiments also showed that the breakup length of the liquid core is sharply shortened as the liquid jet is changed from the laminar to the turbulent flow conditions. In the numerical and physical modeling arena, most of commonly used atomization models do not include the turbulence effect. Limited attempts have been made in modeling the turbulence phenomena on the liquid jet disintegration. The subject correlation and models treat the turbulence either as an only source or a primary driver in the breakup process. This study aims to model the turbulence effect in the atomization process of a cylindrical liquid jet. In the course of this study, two widely used models, Reitz's primary atomization (blob) and Taylor-Analogy-Break (TAB) secondary droplet breakup by O Rourke et al. are examined. Additional terms are derived and implemented appropriately into these two models to account for the turbulence effect on the atomization process. Since this enhancement effort is based on a framework of the two existing atomization models, it is appropriate to denote the two present models as T-blob and T-TAB for the primary and secondary atomization predictions, respectively. In the primary breakup model, the level of the turbulence effect on the liquid breakup depends on the characteristic time scales and the initial flow conditions. This treatment offers a balance of contributions of individual physical phenomena on the liquid breakup process. For the secondary breakup, an addition turbulence force acted on parent drops is modeled and integrated into the TAB governing equation. The drop size formed from this breakup regime is estimated based on the energy balance before and after the breakup occurrence. The turbulence energy is also considered in this process.

  19. Modern nuclear force predictions for n -3H scattering above the three- and four-nucleon breakup thresholds

    NASA Astrophysics Data System (ADS)

    Lazauskas, Rimantas

    2015-04-01

    Background: Description of the collision process, which includes breakup, is one of the most challenging problems of the quantum mechanics. Recently I have developed a formalism based on the complex-scaling method, which describes accurately nuclear collisions in three- and four-body systems. Purpose: To provide accurate calculations for n -3H scattering above the three- and four-nucleon breakup thresholds. Method: A four-nucleon system is described in configuration space employing Faddeev-Yakubovsky equations. The complex-scaling method is applied to overcome the difficulties related with the complicated boundary conditions. Results: Elastic observables as well as total breakup cross sections are calculated for neutron scattering on tritium at 14.1, 18, and 22.1 MeV using realistic NN interactions. Excellent agreement is found with the pioneering calculations of this process reported by A. Deltuva et al. [Phys. Rev. C 86, 011001 (2012), 10.1103/PhysRevC.86.011001]. Strong correlation of the calculated cross sections is established with model-predicted trinucleon binding energy. The forementioned observables reveal little sensitivity to the short-range details of NN interaction. Conclusion: Reliable and accurate methods are now available to study four-nucleon scattering including the breakup.

  20. Birefringence (rotation of polarization plane and spin dichroism) of deuterons in carbon target

    E-print Network

    V. Baryshevsky; A. Rouba

    2007-10-05

    Birefringence phenomenon for deuteron with energy up 20 MeV in carbon target is considered. The estimation for spin dichroism and for angle of rotation of polarization plane of deuterons is presented. It is shown that magnitude of the phenomenon strongly depends on behavior of the deuteron wave functions on small distance between nucleon in deuteron.

  1. Extracting electric dipole breakup cross section of one-neutron halo nuclei from breakup observables

    E-print Network

    Kazuki Yoshida; Tokuro Fukui; Kosho Minomo; Kazuyuki Ogata

    2014-07-25

    How to extract an electric dipole (E1) breakup cross section \\sigma(E1) from one- neutron removal cross sections measured by using 12C and 208Pb targets, \\sigma_(-1n)^C and \\sigma_(-1n)^Pb, respectively, is discussed. It is shown that within about 5% error, \\sigma(E1) can be obtained by subtracting \\Gamma \\sigma_(-1n)^C from \\sigma_(- 1n)^Pb, as assumed in preceding studies. However, for the reaction of weakly-bound projectiles, the scaling factor \\Gamma is found to be two times as large as that usually adopted. As a result, we obtain 13-20% smaller \\sigma(E1) of 31Ne at 250 MeV/nucleon than extracted in a previous analysis of experimental data. By compiling the values of \\Gamma obtained for several projectiles, \\Gamma=(2.30 +/- 0.41)\\exp(- S_n)+(2.43 +/- 0.21) is obtained, where S_n is the neutron separation energy. The target mass number dependence of the nuclear parts of the one-neutron removal cross section and the elastic breakup cross section is also investigated.

  2. History of satellite break-ups in space

    NASA Technical Reports Server (NTRS)

    Gabbard, J.

    1985-01-01

    By 28 June 1961 the 1st Aerospace Control Squadron had cataloged 115 Earth orbiting satellites from data supplied by a rather diverse collection of radar and optical sensors. On 29 June 1961, the Able Star rocket of the 1961 Omicron launch exploded causing a quantum jump in the number of Earth orbiting objects. Since that time there have been 69 Earth orbiting satellites break up in space whose debris remained in orbit long enough for orbital elements to be developed. A list of the 69 breakups is provided. The debris from some of the lower altitude breakups has all decayed. Among the 69 breakups, 44 have cataloged debris remaining in orbit. As of 1 July 1982, the size of the cataloged orbiting population was exactly 4700. Forty-nine percent of these objects are fragments of the forty-four breakups. For each breakup the various orbits of its debris represent a family of orbits that are related in characteristics due to their common impulse launch. A few examples are shown of how the families are oriented in space.

  3. Deuteron polarimetry studies at low and intermediate energies

    NASA Astrophysics Data System (ADS)

    Arvieux, J.; Baker, S. D.; Boudard, A.; Cameron, J.; Hasegawa, T.; Hutcheon, D.; Kerboul, C.; Gaillard, G.; Van Sen, Nguyen

    1988-12-01

    A polarized deuteron beam has been developed at the Saturne 2 synchrotron for energies up to 2.3 GeV. Calibration of the vector and tensor polarization before injection is done with the d(d, p)t reaction induced by 386 keV deuterons. The possibility of depolarizing effects is discussed. Determination of the absolute analyzing powers using quasi-free proton-proton scattering, induced by high energy polarized deuterons, and the p(d, 3He)? 0 reaction are described. New polarization standards are proposed.

  4. New forms of deuteron equations and wave function representations

    SciTech Connect

    Fachruddin, I.; Elster, Ch.; Glo''ckle, W.

    2001-05-01

    A recently developed helicity basis for nucleon-nucleon (NN) scattering is applied to the deuteron bound state. Here the total spin of the deuteron is treated in such a helicity representation. For the bound state, two sets of two coupled eigenvalue equations are developed, where the amplitudes depend on two variables and one variable, respectively. Numerical illustrations based on the realistic Bonn-B NN potential are given. In addition, an ''operator form'' of the deuteron wave function is presented, and several momentum dependent spin densities are derived and shown, in which the angular dependence is given analytically.

  5. Deuteron formation in the reaction /sup 12/C(e,e'd)/sup 10/B/sub T//sub //sub = //sub 1/

    SciTech Connect

    Ent, R.; Berman, B.L.; Blok, H.P.; van den Brand, J.F.J.; Briscoe, W.J.; Jans, E.; Kramer, G.J.; Lanen, J.B.J.M.; Lapikas, L.; Norum, B.E.; and others

    1989-01-02

    In the reaction /sup 12/C(e,e'd)/sup 10/B the lowest-lying T = 1 state in /sup 10/B is found to be as strongly excited as the T = 0 ground state of /sup 10/B, although the transition to the T = 1 state is isospin forbidden for direct deuteron knockout. A mechanism of integration of a p-n pair in a relative T = 1 state into a deuteron is proposed to explain this result. This new proposed mechanism is consistent with both the observed purely transverse character of the transition and the momentum-transfer dependence of the cross section.

  6. Effect of startup conditions on drop breakup under shear with inertia

    E-print Network

    Renardy, Yuriko

    Effect of startup conditions on drop breakup under shear with inertia Yuriko Renardy 1 Department startup induces drop oscillations which are sufficiently large to lead to breakup , while a gentle startup

  7. Deuteron forward photodisintegration: meson currents and relativity

    SciTech Connect

    Friar, J.L.

    1983-01-01

    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.

  8. Intermediate energy proton-deuteron elastic scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1973-01-01

    A fully symmetrized multiple scattering series is considered for the description of proton-deuteron elastic scattering. An off-shell continuation of the experimentally known twobody amplitudes that retains the exchange symmeteries required for the calculation is presented. The one boson exchange terms of the two body amplitudes are evaluated exactly in this off-shell prescription. The first two terms of the multiple scattering series are calculated explicitly whereas multiple scattering effects are obtained as minimum variance estimates from the 146-MeV data of Postma and Wilson. The multiple scattering corrections indeed consist of low order partial waves as suggested by Sloan based on model studies with separable interactions. The Hamada-Johnston wave function is shown consistent with the data for internucleon distances greater than about 0.84 fm.

  9. Nucleon and Deuteron Form Factors from BLAST

    SciTech Connect

    Hasell, D. K. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2009-12-17

    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.

  10. Surface-integral formalism of deuteron stripping

    E-print Network

    A. M. Mukhamedzhanov; D. Y. Pang; C. A. Bertulani; A. S. Kadyrov

    2014-08-24

    The purpose of this paper is to develop an alternative theory of deuteron stripping to resonance states based on the surface integral formalism of Kadyrov et al. [Ann. Phys. 324, 1516 (2009)] and continuum-discretized coupled channels (CDCC). First we demonstrate how the surface integral formalism works in the three-body model and then we consider a more realistic problem in which a composite structure of target nuclei is taken via optical potentials. We explore different choices of channel wave functions and transition operators and show that a conventional CDCC volume matrix element can be written in terms of a surface-integral matrix element, which is peripheral, and an auxiliary matrix element, which determines the contribution of the nuclear interior over the variable $r_{nA}$. This auxiliary matrix element appears due to the inconsistency in treating of the $n-A$ potential: this potential should be real in the final state to support bound states or resonance scattering and complex in the initial state to describe $n-A$ scattering. Our main result is formulation of the theory of the stripping to resonance states using the prior form of the surface integral formalism and CDCC method. It is demonstrated that the conventional CDCC volume matrix element coincides with the surface matrix element, which converges for the stripping to the resonance state. Also the surface representation (over the variable $r_{nA}$ of the stripping matrix element enhances the peripheral part of the amplitude although the internal contribution doesn't disappear and increases with increase of the deuteron energy. We present calculations corroborating our findings for both stripping to the bound state and the resonance.

  11. Novel Physics with Tensor Polarized Deuteron Targets

    SciTech Connect

    Slifer, Karl J. [UNH; Long, Elena A. [UNH

    2013-09-01

    Development of solid spin-1 polarized targets will open the study of tensor structure functions to precise measurement, and holds the promise to enable a new generation of polarized scattering experiments. In this talk we will discuss a measurement of the leading twist tensor structure function b1, along with prospects for future experiments with a solid tensor polarized target. The recently approved JLab experiment E12-13-011 will measure the lead- ing twist tensor structure function b1, which provides a unique tool to study partonic effects, while also being sensitive to coherent nuclear properties in the simplest nuclear system. At low x, shadowing effects are expected to dominate b1, while at larger values, b1 provides a clean probe of exotic QCD effects, such as hidden color due to 6-quark configuration. Since the deuteron wave function is relatively well known, any non-standard effects are expected to be readily observable. All available models predict a small or vanishing value of b1 at moderate x. However, the first pioneer measurement of b1 at HERMES revealed a crossover to an anomalously large negative value in the region 0.2 < x < 0.5, albeit with relatively large experimental uncertainty. E12-13-011 will perform an inclusive measurement of the deuteron tensor asymmetry in the region 0.16 < x < 0.49, for 0.8 < Q2 < 5.0 GeV2. The UVa solid polarized ND3 target will be used, along with the Hall C spectrometers, and an unpolarized 115 nA beam. This measurement will provide access to the tensor quark polarization, and allow a test of the Close-Kumano sum rule, which vanishes in the absence of tensor polarization in the quark sea. Until now, tensor structure has been largely unexplored, so the study of these quantities holds the potential of initiating a new field of spin physics at Jefferson Lab.

  12. On the breakup of tectonic plates by polar wandering

    NASA Technical Reports Server (NTRS)

    Liu, H.-S.

    1974-01-01

    The equations for the stresses in a homogeneous shell of uniform thickness caused by a shift of the axis of rotation are derived. The magnitude of these stresses reaches a maximum value of the order of 10 to the 9th power dyn/sq cm, which is sufficient for explaining a tectonic breakup. In order to deduce the fracture pattern according to which the breakup of tectonic plates can be expected the theory of plastic deformation of shells is applied. The analysis of this pattern gives an explanation of the existing boundary systems of the major tectonic plates as described by Morgan (1968), LePichon (1968) and Isacks et al. (1968).

  13. Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST

    E-print Network

    Kohl, M.

    We report a precision measurement of the deuteron tensor analyzing powers T[subscript 20] and T[subscript 21] at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range ...

  14. Deuteron-nucleus collisions in a multiphase transport model 

    E-print Network

    Lin, ZW; Ko, Che Ming.

    2003-01-01

    Using a multiphase transport model, we study pseudorapidity distributions and transverse momentum spectra in deuteron-gold collisions at RHIC. We find that final-state partonic and hadronic interactions affect the transverse momentum spectrum...

  15. GENTLE IONISATION AND VIOLENT BREAK-UP OF MOLECULES USING SOFT X-RAYS

    E-print Network

    Bapat, Bhas

    GENTLE IONISATION AND VIOLENT BREAK-UP OF MOLECULES USING SOFT X-RAYS Bhas Bapat PRL, Ahmedabad RRCAT Indore, June 2012 BHAS BAPAT (PRL, AHMEDABAD) BREAK-UP OF MOLECULES USING SOFT X-RAYS RRCAT INDORE INVESTIGATED RECENT RESULTS BHAS BAPAT (PRL, AHMEDABAD) BREAK-UP OF MOLECULES USING SOFT X-RAYS RRCAT INDORE

  16. Modeling suggests that oblique extension facilitates rifting and continental break-up

    E-print Network

    Kaus, Boris

    Modeling suggests that oblique extension facilitates rifting and continental break-up Sascha Brune; accepted 5 June 2012; published 2 August 2012. [1] In many cases the initial stage of continental break-up was and is associated with oblique rifting. That includes break-up in the Southern and Equatorial Atlantic, separation

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

    SciTech Connect

    Sargsian, Misak [Department of Physics, Florida International University, Miami, FL 33199 (United States)

    2008-10-13

    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 {sup 3}He 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.

  18. NOTE: A Model for the Breakup of Comet LINEAR (C/1999 S4)

    NASA Astrophysics Data System (ADS)

    Samarasinha, Nalin H.

    2001-12-01

    We propose a mechanism based on the rubble-pile hypothesis of the cometary nucleus (Weissman 1986, Nature320, 242-244) to explain the catastrophic breakup of comet LINEAR (C/1999 S4) observed during July-August 2000. We suggest that a solid nucleus made up of 10-100 m "cometesimals" (Weidenschilling 1997, Icarus127, 290-306) contains a network of interconnected voids in the intercometesimal regions. The production of super-volatile (i.e., species more volatile than water) gasses into these voids occurs as a result of the thermal wave propagating through the nucleus and associated phase transitions of water ice. The network of voids provides an efficient pathway for rapid propagation of these gasses within the nucleus resulting in gas pressure caused stresses over a wide regime of the nucleus. This provides a mechanism for catastrophic breakups of small cometary nuclei such as comet LINEAR (C/1999 S4) as well as for some observed cometary outbursts including those that occur at large heliocentric distances (e.g., West et al. 1991, Astron. Astrophys.246, L77-L80). We emphasize the importance of techniques such as radar reflection tomography and radiowave transmission tomography (e.g., Kofman et al. 1998, Adv. Space Res. 21, 1589-1598) aboard cometary missions to determine the three-dimensional structure of the nucleus, in particular the extent of large-scale voids.

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

    NASA Astrophysics Data System (ADS)

    Sargsian, Misak

    2008-10-01

    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.

  20. Primary breakup of a liquid jet in a transverse shock-induced flow

    NASA Astrophysics Data System (ADS)

    Ateshkadi, A.; Eastes, T. W.; Samuelsen, G. S.

    1993-06-01

    An imaging technique is used to investigate the fluid dynamics associated with the breakup of a liquid jet by a passing transverse shock wave. This mechanism is believed to be a potential source of combustion instability in liquid propellant rocket engines. Combustion instability is caused by the release of heat in phase with a passing pressure disturbance. The jet/wave interaction causes rapid atomization and propellant redistribution, and enhances mixing, vaporization, and reaction rates. Knowledge of the breakup process aids in prediction of local heat release with respect to the passing wave and provides insight on its viability as a potential instability mechanism. The present shock tube study applies high-speed, high-resolution photography to explore the jet/wave interaction that might be experienced in a large scale liquid oxygen/hydrogen (LOX/H2) engine similar to the SSME or other such engines being considered for the next generation of launch systems. Fluid parameters deemed important were simulated as well as possible. Time-resolved images of the jet/wave interaction indicate very rapid and fine atomization within 500 microsec of impingement.

  1. A Model for the Breakup of Comet Linear (C/1999 S4)

    NASA Technical Reports Server (NTRS)

    Samarasinha, Nalin H.

    2001-01-01

    We propose a mechanism based on the rubble-pile hypothesis of the cometary nucleus (Weissman 1986) to explain the catastrophic breakup of comet LINEAR (C/1999 S4) observed during July-August 2000. We suggest that a solid nucleus made up of 10-100 m "cometesimals" (Weidenschilling 1997) contains a network of inter-connected voids in the inter-cometesimal regions. The production of super-volatile (i.e., species more volatile than water) gases into these voids occurs due to the thermal wave propagating through the nucleus and associated phase transitions of water ice. The network of voids provides an efficient pathway for rapid propagation of these gases within the nucleus resulting in gas pressure caused stresses over a wide regime of the nucleus. This provides a mechanism for catastrophic breakups of small cometary nuclei such as comet LINEAR (C/1999 S4) as well as for some observed cometary outbursts including those that occur at large heliocentric distances (e.g., West et al. 1991). We emphasize the importance of techniques such as radar reflection tomography and radiowave transmission tomography (e.g., Kofman et al. 1998) aboard cometary missions to determine the three dimensional structure of the nucleus in particular the extent of large scale voids.

  2. Critical behavior of droplet breakup in T-junction microchannels

    NASA Astrophysics Data System (ADS)

    van Steijn, Volkert; Hoang, Duong; Portela, Luis; Kleijn, Chris; Kreutzer, Michiel

    2013-11-01

    The critical behavior of droplet breakup in T-junction mirochannels is studied using three-dimensional numerical simulations. Two scenarios can happen when a droplet flows into a T-junction: (i) if the flow is strong enough, it breaks into two daughter droplets and (ii) otherwise, it drifts away into one branch of the T-junction owing to flow perturbations. Whether a droplet breaks or not is determined by the ratio between two timescales: breakup time and drifting time. Symmetric-boundary-condition simulations allow us to study the breakup time without any flow perturbations, thus to accurately compute the critical capillary number below which the droplet does not break. We study the drifting using full-T-junction simulations, identifying three phases in drifting process: (i) an exponential drifting, (ii) a transition phase and (iii) a linear drifting. Combining the understanding of the breakup and drifting behavior, we found that the critical capillary number below which the droplet drifts away increases more than 10% with respect to the one obtained in free-perturbation flow systems.

  3. Capillary instability and breakup of a viscous thread

    Microsoft Academic Search

    C. Pozrikidis

    1999-01-01

    Papageorgiou derived a similarity solution that describes the asymptotic behavior of a thinning viscous thread suspended in vacuum, near the critical time and around the location of breakup. The motion is driven by surface tension, and the fluid inertia is neglected throughout the evolution. To assess the physical relevance of the similarity solution, the evolution of an infinite thread immersed

  4. Mass estimation in the breakups of Soviet satellites

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.; Anz-Meador, Phillip D.

    1990-01-01

    An attempt is made to estimate the mass of the parent satellite from the mass of the debris remaining from its breakup using a technique based on the decay rate and radar cross-section time history. The decay of perigee and apogee with time of an object in orbit provides the area-to-mass ratio and the radar cross-section provides a measure of the effective area of the object, while combining the two gives the mass of the object. The technique has been successfully applied to 12 U.S. breakups and one Arianespace breakup. Calculations exhibiting good agreement with reference mass are also discussed for Soviet intact C-class boosters, intact ASAT target satellites, and intact navigational satellites. It is found that the calculated mass of the ASAT interceptor spacecraft is about one-half of the expected mass, but it is pointed out that this may be due to fuel carried on board. For ASAT target breakups the calculated mass is 20-30 times too low; no clear explanation can yet be found for this phenomenon.

  5. Breakup of New Orleans Households after Hurricane Katrina

    ERIC Educational Resources Information Center

    Rendall, Michael S.

    2011-01-01

    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…

  6. Surfactant effects in dynamics and breakup of a contracting liquid filament

    NASA Astrophysics Data System (ADS)

    Xu, Qi

    2005-11-01

    The effects of a monolayer of insoluble surfactant on the dynamics of contraction and breakup of a liquid filament in air are studied by solving numerically the Navier-Stokes system that governs the time evolution of the filament shape and the velocity and pressure fields within it and the time-dependent convection-diffusion equation that governs surfactant transport on the air-liquid interface. Five dimensionless parameters govern this free boundary problem: dimensionless filament half-length L, Ohnesorge number Oh (viscous/capillary force), dimensionless initial surfactant loading ?, a parameter ? which provides a measure of the strength of the surfactant, and surface Peclet number Pe (convection/diffusion of surfactant). Computational results show that when Pe is low, Marangoni effects are weak and the dynamics closely resemble those of a surfactant-free filament. In contrast, when Pe is high, Marangoni stresses can prevent filament breakup via the end-pinching mode. Vorticity dynamics within the filament are also examined to help shed light on the fluid mechanics of the contraction process.

  7. Exotic break-up modes in heavy ion reactions at low energies

    E-print Network

    C. Rizzo; M. Colonna; V. Baran; M. Di Toro

    2014-07-03

    New reaction mechanisms occurring in heavy ion collisions at low energy (10- 30 MeV/A) are investigated within the Stochastic Mean Field model. We concentrate on the analysis of ternary breakup events, of dynamical origin, occurring in semi-central reactions, where the formation of excited systems in various conditions of shape and angular momentum is observed. We show how this fragmentation mode, which can be considered as a precursor of the neck emission observed at higher beam energies, emerges from the combined action of surface (neck) instabilities and angular momentum effects. Interesting perspectives are opening towards the investigation of this mechanism in neutron-rich (or exotic) systems, with the possibility to access information on the low-density behavior of the nuclear symmetry energy.

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

    PubMed Central

    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

    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

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

    PubMed

    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

    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

  10. Deuteron injector for Peking University Neutron Imaging Facility project

    SciTech Connect

    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

    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.

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

    SciTech Connect

    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

    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.

  12. Using Tensor Momentum Dependent Deuteron Potential to Extract the Asymptotic D/S Ratio

    SciTech Connect

    Emad El-Deen, A. Sultan; Mustafa, Mustafa M. [Physics department, Faculty of Science, Sohag University (Egypt); Zahran, Elbadry S. [Physics department, Faculty of Science, Assiut University (Egypt)

    2010-09-30

    A new value for the deuteron asymptotic D/S ratio {eta} = 0.02640{+-}0.00024 is extracted from an empirical linear {eta}-Q relation found for a class of deuteron momentum dependent potentials with tensor momentum dependent part. These potentials fit a recently published phase shift analysis and the binding energy of the deuteron.

  13. Structure and evolution of a magmatic rift segment close to continental breakup

    NASA Astrophysics Data System (ADS)

    Medynski, Sarah; Pik, Raphaël; Burnard, Peter; Stab, Martin; Vye-Brown, Charlotte; France, Lyderic

    2014-05-01

    The continental-oceanic transition (OCT) at volcanic margins is often associated with large volcanic provinces and with specific tecto/volcanic structures, notably seaward dipping reflectors (SDRs), of which the origin and processes of formation are still debated. The Afar province corresponds to the very last observable stages of continental rifting before breakup. Interestingly, in this area where the continental crust remains ~20 km thick, magmatism and tectonic activity are already clearly expressed in well-individualised rift segments, presenting the morphological characteristics of mature oceanic ridges. The Afar region therefore represents an ideal natural laboratory to study the processes responsible for maintaining magmatic accretion and their links with the distribution of deformation in a pre-breakup context. We have focussed on the Dabbahu segment that experienced a diking event in 2005 that has been studied in detail. The subsequent tectono-volcanic crisis that lasted 5 years, has provided invaluable information on the mechanisms controlling dyke intrusion, the main process responsible for extension at the scale of a single rifting event. Our investigations focussed on the 1 to 100 kyrs timescales - a key period over which the main morphology of a rift/ridge segment is acquired, but which currently lacks chronological constraints. In order to bridge this gap in temporal evolution, our multidisciplinary approach combines surface exposure dating (3He and 36Cl) of lavas and fault scarps with major & trace element compositions and field/remote sensing mapping of the Dabbahu rift. Our results show that accretion is maintained by individual magmatic chambers, distributed along the active rift segment. There, we have identified magmatic cycles of 30-40 kyrs duration during which the magmas progressively differentiate, until the magmatic centre is abandoned. These cycles exert a strong control on the building of topography: the tectonic activity is subdued during the active phases of the magma chamber, and are enhanced when the magmatic activity decreases. Our measurements show that the fault scarps have a continuous slip rate along the neo-volcanic zone, between 1-2 mm/yr. We also identify several individual palaeo-tectonic events of metric amplitude (very similar to the 2005 crisis) which suggest that the main process responsible for the building of the axial depression is indeed dike intrusions. This implies that in pre-breakup stages accretion is already organised and maintained by processes similar to those occurring in mature oceanic ridges. The question arises to know if these mechanisms, observed here on the scale of a few tens of kyrs, could be responsible for the creation of SDRs, implying these mechanisms operate on timescales of a few million years.

  14. A methodology of MSL breakup analysis for Earth accidental reentry and its application to breakup analysis for Mars off-nominal entry

    NASA Technical Reports Server (NTRS)

    Salama, Ahmed; Ling, Lisa

    2005-01-01

    Vehicle breakup analysis has been performed for missions that may carry nuclear fuel for heating or power purposes to assess nuclear safety in case of launch failure leading to atmospheric reentry. Also, failure scenarios exist which could lead to breakup during Entry / Descent / Landing (EDL) at Mars due to off-nominal entries, with implications for planetary protection requirements. Since the Mars Science Laboratory (MSL) spacecraft may include a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), an analysis of breakup in case of launch failure is required. Also, breakup during Mars EDL due to off-nominal entries could release the RTG heat source that has implications for planetary protection requirements. This paper presents a methodology of MSL breakup analysis for launch failure with application to Mars off-nominal entry.

  15. Semiclassical calculations of observable cross sections in breakup reactions

    SciTech Connect

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

    2008-09-15

    We develop a semiclassical procedure to calculate breakup reaction products' angular and energy distributions in the laboratory frame of reference. The effects of the Coulomb and nuclear interaction potentials on the classical trajectories, as well as bound-bound, bound-continuum, and continuum-continuum couplings, are included. As an example we consider the {sup 8}B+{sup 58}Ni system at E{sub lab}=26 MeV and find very good agreement with the available experimental data.

  16. Radial electron-beam-breakup transit-time oscillator

    SciTech Connect

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

    1995-01-01

    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.

  17. Fusion and breakup at the barrier with unstable nuclei

    Microsoft Academic Search

    C. Signorini

    1997-01-01

    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

  18. A Spin-Frozen Polarized Target of Proton and Deuteron

    NASA Astrophysics Data System (ADS)

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

    1989-10-01

    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.

  19. Large enhancement of deuteron polarization with frequency modulated microwaves

    E-print Network

    The SMC Collaboration

    1995-10-01

    We report a large enhancement of 1.7 in deuteron polarization up to values of 0.6 due to frequency modulation of the polarizing microwaves in a two liters polarized target using the method of dynamic nuclear polarization. This target was used during a deep inelastic polarized muon-deuteron scattering experiment at CERN. Measurements of the electron paramagnetic resonance absorption spectra show that frequency modulation gives rise to additional microwave absorption in the spectral wings. Although these results are not understood theoretically, they may provide a useful testing ground for the deeper understanding of dynamic nuclear polarization.

  20. Elliptic flow of deuterons in relativistic heavy-ion collisions

    SciTech Connect

    Oh, Yongseok; Ko, Che Ming [Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843-3366 (United States)

    2007-11-15

    Using a dynamical model based on the NN{yields}d{pi},NNN{yields}dN, and NN{pi}{yields}d{pi} reactions and measured proton and pion transverse momentum spectra and elliptic flows, we study the production of deuterons and their elliptic flow in heavy-ion collisions at RHIC. The results are compared with those from the coalescence model. The deviation of deuteron elliptic flow from the constituent nucleon number scaling expected from the coalescence model and the comparison with the experimental data are discussed in connection to the allowed nucleon phase space in these reactions.

  1. The deuteron structure function F2 with CLAS

    SciTech Connect

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

    2005-07-01

    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.

  2. P and T Violating Form Factors of the Deuteron

    SciTech Connect

    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

    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.

  3. A model of plate kinematics in Gondwana breakup

    NASA Astrophysics Data System (ADS)

    Eagles, Graeme; König, Matthias

    2008-05-01

    An accurate model of relative plate motions in Gondwana breakup is based on visual fitting of seafloor isochrons and fracture zones (FZ) from the Riiser-Larsen Sea and Mozambique Basin. Used predictively, the model precisely locates kinematic markers in the West Somali Basin, which allows the conclusion that the spreading centres in the West Somali and Mozambique basins and the Riiser-Larsen Sea formed parts of the boundary between the same two plates. The locations of FZ and less well-defined isochrons from neighbouring regions are also consistent with their formation on other lengths of this same boundary and with its relocation from the West Somali Basin and northern Natal Valley to the West Enderby Basin and Lazarev Sea during chron M10n. Small independently moving plates thus played no role in the breakup of this core part of Gondwana. In an inversion procedure, the data from these areas yield more precise finite rotations that describe the history of the two plates' separation. Breakup is most simply interpreted to have occurred in coincidence with Karoo volcanism, and a reconstruction based on the rotations shows the Lebombo and Mateke-Sabi monoclines and the Mozambique and Astrid ridges as two sets of conjugate volcanic margins. Madagascar's pre-drift position can be used as a constraint to reassess the positions of India and Sri Lanka in the supercontinent.

  4. Transverse liquid fuel jet breakup, burning, and ignition

    SciTech Connect

    Li, H.

    1990-12-31

    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.

  5. Isoscalar Spin Strength in CARBON-12 and Calcium -40 Measured by Polarized Deuteron, Polarized Deuteron' Scattering

    NASA Astrophysics Data System (ADS)

    Johnson, Barry Newell

    1993-01-01

    The distribution of isoscalar spin strength in ^{12}C and ^ {40}Ca was measured with the inelastic scattering of 400 MeV polarized deuterons. Both nuclei were studied at laboratory angles from 3^ circ to 7^circ, and the isoscalar spin strength distributions were mapped out up to approximately 57 MeV in excitation energy for ^{12}C and 42 MeV in ^{40}Ca. Previously unknown concentrations of isoscalar spin strength were found in ^{40}Ca in the regions around 8 MeV and 15 MeV. New clusters of strength were also found in ^{12}C, near 21 and 30 MeV, as well as a possible new Delta T = 0, Delta S = 1 discrete state at 20.5 MeV. Very little collectivity was seen in either nucleus, which is consistent with theoretical and experimental predictions of a weakly repulsive residual interaction in this channel.

  6. Systematic study of breakup effects on complete fusion at energies above the Coulomb barrier

    E-print Network

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

    2014-09-09

    A large number of complete fusion excitation functions of reactions including the breakup channel were measured in recent decades, especially in the last few years. It allows us to investigate the systematic behavior of the breakup effects on the complete fusion cross sections. To this end, we perform a systematic study of the breakup effects on the complete fusion cross sections at energies above the Coulomb barrier. The reduced fusion functions F(x) are compared with the universal fusion functions which are used as a uniform standard reference. The complete fusion cross sections at energies above the Coulomb barrier are suppressed by the breakup of projectiles. This suppression effect for reactions induced by the same projectile is independent of the target and mainly determined by the lowest energy breakup channel of the projectile. There holds a good exponential relation between the suppression factor and the energy corresponding to the lowest breakup threshold.

  7. Analysis of video imagery of the reentry and breakup of the STS31 external tank

    Microsoft Academic Search

    Michael W. Snyder; David E. Pitts

    1992-01-01

    Some of the major questions concerning the reentry and breakup of the STS-31 external tank (ET), which had a deactivated tumble valve, are addressed. The time of breakup, the altitude, and the geographic location of the ET at breakup were determined. The tumble rate was estimated to be between 8.59 deg and 8.84 deg\\/s. The ET broke up into at

  8. Analysis of video imagery of the reentry and breakup of the STS-31 external tank

    NASA Technical Reports Server (NTRS)

    Snyder, Michael W.; Pitts, David E.

    1992-01-01

    Some of the major questions concerning the reentry and breakup of the STS-31 external tank (ET), which had a deactivated tumble valve, are addressed. The time of breakup, the altitude, and the geographic location of the ET at breakup were determined. The tumble rate was estimated to be between 8.59 deg and 8.84 deg/s. The ET broke up into at least 50 pieces 7 s after initial rupture.

  9. Analysis of video imagery of the reentry and breakup of the STS-31 external tank

    NASA Astrophysics Data System (ADS)

    Snyder, Michael W.; Pitts, David E.

    Some of the major questions concerning the reentry and breakup of the STS-31 external tank (ET), which had a deactivated tumble valve, are addressed. The time of breakup, the altitude, and the geographic location of the ET at breakup were determined. The tumble rate was estimated to be between 8.59 deg and 8.84 deg/s. The ET broke up into at least 50 pieces 7 s after initial rupture.

  10. Barrier distribution from Be9+Pb208 quasielastic scattering: Breakup effects in the interaction processes

    NASA Astrophysics Data System (ADS)

    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.

    2010-08-01

    Excitation function of the quasielastic (QEL) scattering at a backward angle was measured for the weakly bound projectile Be9, which bombarded a Pb208 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 Be9 on a spherical target Pb208.

  11. Evidence of Ni break-up from total production cross sections in p+Ni collisions

    E-print Network

    Budzanowski, A; Filges, D; Goldenbaum, F; Hodde, H; Jarczyk, L; Kamys, B; Kistryn, M; Kistryn, St; Kliczewski, St; Kowalczyk, A; Kozik, E; Kulessa, P; Machner, H; Magiera, A; Piskor-Ignatowicz, B; Pysz, K; Rudy, Z; Siudak, R; Wojciechowski, M

    2009-01-01

    The total production cross sections of light charged particles (LCPs), intermediate mass fragments (IMFs) and heavy reaction products of p+Ni collisions available in the literature have been compared with predictions of a two-step model in the proton beam energy range from reaction threshold up to approximately 3 GeV. Model cross sections were calculated assuming, that the reaction proceeds via an intranuclear cascade of nucleon-nucleon collisions followed by evaporation of particles from an equilibrated, heavy target residuum. The shape of the excitation functions was well described by model calculations for all reaction products. The magnitude of the cross sections was reasonably well reproduced for heavy reaction products, i.e. for nuclei heavier than Al, but the cross sections for lighter products were systematically underestimated. This fact was used as an argument in favor of a significant break-up contribution to the reaction mechanism. The present conclusions are supported by recently published result...

  12. An Analysis of Recent Major Breakups in the Low Earth Orbit Region

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.; Anz-Meador, P. D.

    2010-01-01

    Of the 4 recent major breakup events, the FY-1C ASAT test and the collision between Iridium 33 and Cosmos 2251 generated the most long-term impact to the environment. About half of the fragments will still remain in orbit at least 20 years after the breakup. The A/M distribution of the Cosmos 2251 fragments is well-described by the NASA Breakup Model. Satellites made of modern materials (such as Iridium 33), equipped with large solar panels, or covered with large MLI layers (such as FY-1C) may generated significant amount of high A/M fragments upon breakup.

  13. Observations of breakup processes of liquid jets using real-time X-ray radiography

    NASA Technical Reports Server (NTRS)

    Char, J. M.; Kuo, K. K.; Hsieh, K. C.

    1988-01-01

    To unravel the liquid-jet breakup process in the nondilute region, a newly developed system of real-time X-ray radiography, an advanced digital image processor, and a high-speed video camera were used. Based upon recorded X-ray images, the inner structure of a liquid jet during breakup was observed. The jet divergence angle, jet breakup length, and fraction distributions along the axial and transverse directions of the liquid jets were determined in the near-injector region. Both wall- and free-jet tests were conducted to study the effect of wall friction on the jet breakup process.

  14. The visibility of color breakup and a means to reduce it

    PubMed Central

    Johnson, Paul V.; Kim, Joohwan; Banks, Martin S.

    2014-01-01

    Color breakup is an artifact seen on displays that present colors sequentially. When the eye tracks a moving object on such a display, different colors land on different places on the retina, and this gives rise to visible color fringes at the object's leading and trailing edges. Interestingly, color breakup is also observed when the eye is stationary and an object moves by. Using a novel psychophysical procedure, we measured breakup both when viewers tracked and did not track a moving object. Breakup was somewhat more visible in the tracking than in the non-tracking condition. The video frames contained three subframes, one each for red, green, and blue. We spatially offset the green and blue stimuli in the second and third subframes, respectively, to find the values that minimized breakup. In the tracking and non-tracking conditions, spatial offsets of ?x/3 in the second subframe (where ?x is the displacement of the object in one frame) and 2?x/3 in the third eliminated breakup. Thus, this method offers a way to minimize or even eliminate breakup whether the viewer is tracking or not. We suggest ways to implement the method with real video content. We also developed a color-breakup model based on spatiotemporal filtering in color-opponent pathways in early vision. We found close agreement between the model's predictions and the experimental results. The model can be used to predict breakup for a wide variety of conditions. PMID:25527148

  15. Photonuclear sum rules and interaction effects in the deuteron

    Microsoft Academic Search

    Hartmuth Arenhövel; Werner Fabian

    1977-01-01

    The photonuclear sum rules sigmao, sigma-1, and sigma-2 are evaluated for the deuteron by direct integration of the theoretical cross section up to the pi-threshold. Effects of isobar configurations and mesonexchange currents are included. The integrated cross section is also determined from the double commutator of the dipole operator with the Hamiltonian. The usual potentials increase the classical sum rule

  16. Time Reversal Invariance Violation in Neutron Deuteron Scattering

    E-print Network

    Young-Ho Song; Rimantas Lazauskas; Vladimir Gudkov

    2011-04-15

    Time reversal invariance violating (TRIV) effects for low energy elastic neutron deuteron scattering are calculated for meson exchange and EFT-type of TRIV potentials in a Distorted Wave Born Approximation, using realistic hadronic strong interaction wave functions, obtained by solving three-body Faddeev equations in configuration space. The relation between TRIV and parity violating observables are discussed.

  17. Spin Structure Moments of the Proton and Deuteron

    SciTech Connect

    Slifer, Karl; Rondon-Aramayo, Oscar; Aghalaryan, Aram; Ahmidouch, Abdellah; Asaturyan, Razmik; Bloch, Frederic; Boeglin, Werner; Bosted, Peter; Carasco, Cedric; Carlini, Roger; Cha, Jinseok; Chen, Jian-Ping; Christy, Michael; Cole, Leon; Coman, Luminita; Crabb, Donald; Danagoulian, Samuel; Day, Donal; Dunne, James; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Frlez, Emil; Gaskell, David; Gan, Liping; Gomez, Javier; Hu, Bitao; Jourdan, Juerg; Jones, Mark; Keith, Christopher; Keppel, Cynthia; Khandaker, Mahbubul; Klein, Andreas; Kramer, Laird; Liang, Yongguang; Lichtenstadt, Jechiel; Lindgren, Richard; Mack, David; McKee, Paul; McNulty, Dustin; Meekins, David; Mkrtchyan, Hamlet; Nasseripour, Rakhsha; Niculescu, Maria-Ioana; Normand, Kristoff; Norum, Blaine; Pocanic, Dinko; Prok, Yelena; Raue, Brian; Reinhold, Joerg; Roche, Julie; Rohe, Daniela; Savvinov, Nikolai; Sawatzky, Bradley; Seely, Mikell; Sick, Ingo; Smith, C.; Smith, G.; Stepanyan, Samuel; Tang, Liguang; Tajima, Shigeyuki; Testa, Giuseppe; Vulcan, William; Wang, Kebin; Warren, G.; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yuan, Lulin; Yun, Junho; Zeier, Markus; Guo Zhu, Hong

    2009-01-01

    Moments of the spin structure functions g1 and g2 of the proton and deuteron have been measured in the resonance region at intermediate four momentum transfer. We perform a Nachtmann moment analysis of this data, along with isovector and isoscalar combinations, in order to rigorously account for target mass effects. This analysis provides the first definitive evidence for dynamic higher twists.

  18. Studying the Delta-Delta component in the Deuteron

    NASA Astrophysics Data System (ADS)

    Adhikari, Shankar; Sargsian, Misak

    2015-04-01

    The Delta-Delta component is expected to be one of the largest non-nucleonic components in the high momenta part of the deuteron wave function. It's magnitude will reveal indirectly the extend of the hidden-color in the deuteron as well as the dynamics relevant to the repulsive core of the NN interaction. To describe this component we developed a theoretical model based on the light-cone perturbation theory in which the Delta-Delta state is due to highly virtual NN-> Delta Delta transition in the intermediate state. Calculation is based on the collinear approximation in which the initial NN state is described by light-cone pn deuteron wave function and the NN-> Delta Delta transition amplitude is parameterized from the experiment with off-shell extrapolation. The model allowed us to calculate the total normalization of the Delta-Delta component as well as predict its momentum distribution. We then demonstrate how this component can be probed in deep-inelastic scattering off the deuteron tagged by fast backward Deltas or in high momentum transfer exclusive reactions that can identify two Delta Isobars in the final state. This work is supported by US DOE Grant DE-FG02-01ER41172.

  19. On the large COMPASS polarized deuteron target , N. Doshitac

    E-print Network

    Dutz, Hartmut

    On the large COMPASS polarized deuteron target J. Balla , G. Baumb , N. Doshitac , M. Finger, Jr target in the COMPASS experiment at CERN since 2001. To achieve high luminosities a large solid polarized target is used. The COMPASS polarized target consists of a high cooling power 3 He/4 He dilution refriger

  20. Neutron-deuteron elastic scattering and three-nucleon force

    E-print Network

    Chtangeev, Maxim B

    2005-01-01

    The differential cross section for neutron-deuteron elastic scattering was measured at six angles over the center-of-mass angular range 65? - 1300? and incident neutron energies 140 - 240 MeV at the LANSCE/WNR facility of ...

  1. Elliptic flow of deuterons in relativistic heavy-ion collisions 

    E-print Network

    Oh, Yongseok; Ko, Che Ming.

    2007-01-01

    Using a dynamical model based on the NN -> d pi,NNN -> dN, and NN pi -> d pi reactions and measured proton and pion transverse momentum spectra and elliptic flows, we study the production of deuterons and their elliptic ...

  2. JLAB Measurements of the Deuteron Electric and Magnetic Form Factors

    SciTech Connect

    Gerassimos G. Petratos

    2000-12-12

    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.

  3. Assessing river ice breakup date, coastal tundra vegetation and climate divisions in the context of Alaska climate variability

    NASA Astrophysics Data System (ADS)

    Bieniek, Peter A.

    In Alaska, there exists a substantial knowledge gap of key climate drivers and filling these gaps is vital since life and the economy are inexorably linked with climate in the state. This thesis identifies and investigates three topics that advance the understanding of Alaska climate variability: the role of large-scale climate in Interior river ice breakup, the link between climate and arctic tundra vegetation, and climate divisions based on objective methods. River ice breakup in the Yukon-Kuskoswim watershed is occurring earlier by 1.3 days decade-1 1948-2008 and displays large year-to-year variability. April-May Interior Alaska air temperatures are the best predictor of river ice breakup and were linked to El Niño Southern Oscillation (ENSO). During the warm phase of ENSO, fewer storms track into the Gulf of Alaska during Boreal Spring, resulting in reduced April-May cloudiness over Alaska, increased solar insolation at the land surface, warmer air temperatures and consequently earlier breakup. Northern Alaska tundra vegetation productivity has increased 1982-2011, based on the Normalized Difference Vegetation Index (NDVI), a satellite measure of vegetation correlated with above ground biomass. Vegetation productivity was linked to the Beaufort High circulation as well as snowfall, in addition to land surface temperatures and coastal sea ice extent. NDVI has decreased from 1982-2011 over the coastal tundra along the Bering Sea and was correlated with delayed springtime warming due to enhanced coastal sea ice and a delayed snowmelt. Cluster analysis was applied to 2-meter air temperature data 1977-2010 at meteorological stations to construct climate divisions for Alaska. Stations were grouped together objectively based on similar homogeneous seasonal and annual climate variability and were refined using local expert knowledge to ultimately identify 13 divisions. Correlation analysis using gridded downscaled temperature and precipitation data validated the final division lines and documented that each division has similar a similar annual cycle in temperature and precipitation. Overall, this work documented substantial links and identified mechanisms joining the large-scale climate to that of Alaska. A better understanding of the role of large-scale climate variability in river ice breakup or tundra greening holds promise for developing seasonal and longer-term forecasts.

  4. Measurement of the Tensor Structure Function b{sub 1} of the Deuteron

    SciTech Connect

    Airapetian, A.; Akopov, N.; Akopov, Z.; Avakian, R.; Avetissian, A.; Elbakian, G.; Gharibyan, V.; Marukyan, H.; Rostomyan, A.; Taroian, S. [Yerevan Physics Institute, 375036 Yerevan (Armenia); Amarian, M. [DESY, 15738 Zeuthen (Germany); Yerevan Physics Institute, 375036 Yerevan (Armenia); Ammosov, V.V.; Bryzgalov, V.; Gapienko, G.; Gapienko, V.; Ivanilov, A.; Korotkov, V.; Salomatin, Y.; Tchuiko, B. [Institute for High Energy Physics, Protvino, 142281 (Russian Federation); Andrus, A. [Department of Physics, University of Illinois, Urbana, Illinois 61801-3080 (United States)] [and others

    2005-12-09

    The Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of DESY HERA. The use of a tensor-polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry A{sub zz}{sup d} and the tensor structure function b{sub 1}{sup d} for average values of the Bjorken variable 0.01<<0.45 and of the negative of the squared four-momentum transfer 0.5 GeV{sup 2}<<5 GeV{sup 2}. The quantities A{sub zz}{sup d} and b{sub 1}{sup d} are found to be nonzero. The rise of b{sub 1}{sup d} for decreasing values of x can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering.

  5. Neutron emission from low energy deuteron injection of deuteron-implanted metal foils (Pd, Ti and In)

    NASA Astrophysics Data System (ADS)

    McKee, J. S. C.; Smith, G. R.; Durocher, J. J. G.; Furutani, K.; Kwok, C. B.; Johnston, H. L.; Mathur, M. S.; Mayer, J. K.; Mirzai, A.; Yeo, Y. H.; Sharma, K. S.; Williams, G.

    1991-05-01

    In examination of the possibility of observing D-D fusion reactions at or near room temperature, our group at Manitoba has searched for an enhancement in the neutron production rate resulting from stopping deuterons interacting with implanted deuterons in a metal matrix. This non-equilibrium process was selected as an alternative to electrolysis as a means of injecting the material. The deuterons were implanted into the metal matrix by a small high current accelerator which accelerated a mixed beam of D+ of energy 60 keV and molecular D2+ which upon dissociation at the surface of the metal yields two 30 keV D+ ions. The precise composition of the beam was unknown. The presence of neutrons was registered continuously during the experimental runs. Scintillation light was detected as the neutrons transferred a portion of their energy to protons in a large plastic scintillator detector. Anomalous occurrences were observed during the operation of the experiment, in the form of sudden increases in the observed neutron detection rates. We undertook to repeat the experiment under more controlled conditions, with the intent of resolving to our satisfaction whether anomalous neutron production was actually occurring. In addition, an attempt to measure X-ray production within the target metal was made. The build up to deuterons in the metal matrix was such that where the density of deuterons in a commercially available TiD target would be expected to be on the order of 4×1028 m-3, our implantation scheme resulted in deuteron densities up to 2×1031 m-3 in the matrix. We argue that the loss of deuterons from the matrix will be small compared to build up rates. The results of our 1989 experiment are being compared with theory and the results of a more recent one (July 1990), currently under analysis. Funding has recently been obtained from our local electric utility, Manitoba Hydro, for the production of analyzed beams of D0, D+ and D2+ for future implantation experiments. Work in this area is now under way.

  6. Final Rifting and Continental Breakup in the South China Sea

    NASA Astrophysics Data System (ADS)

    Franke, D.; Savva, D.; Pubellier, M. F.; Steuer, S.; Mouly, B.; Auxietre, J. L.; Meresse, F.; Chamot-Rooke, N. R. A.

    2014-12-01

    The magma-poor or intermediate magmatic South China Sea basin shows a triangular shape with a SW pointing apex, which manifests a preceding propagating rift. The earliest phase of rifting started in the Early Paleocene when a Mesozoic convergent margin changed to extension. After about 30 Myrs of rifting, breakup in the major eastern subbasin of the SCS occurred in the Early Oligocene and subsequent breakup of the southwest subbasin took place in the Late Oligocene. Seismic reflection data imaging conjugate crustal sections result in a conceptual model for rift-evolution at conjugate margins in time and space. Distinct are regular undulations in the crust-mantle boundary. Individual rift basins are bounded to crustal blocks by listric normal faults on either side. Moho uplifts are distinct beneath major rift basins, while the Moho is downbended beneath crustal blocks. Most of the basin-bounding faults sole out within the middle crust. At the distal margins, detachment faults are located at a mid-crustal level where a weak zone decouples crust and mantle lithosphere during rifting. The lower crust in contrast is interpreted as being strong. Only in the region within about 50 km from the oceanic domain we suggest that normal faults reach the mantle, enabling potentially a coupling between the crust and the mantle. Here, at the proximal margins detachment fault dip either seaward or landward. Largely symmetric structures result from the initial rifting stage. At the future breakup position either of the rift basin bounding faults subsequently penetrates the entire crust, resulting in asymmetry at this location. However, asymmetric deformation which is controlled by large scale detachment faulting is confined to narrow areas and does not result in a margin-wide simple-shear model. Rather considerable along-margin variations are suggested resulting in alternating "upper and lower plate" margins.

  7. Radial electron-beam-breakup transit-time oscillator

    DOEpatents

    Kwan, Thomas J. T. (Los Alamos, NM); Mostrom, Michael A. (Albuquerque, NM)

    1998-01-01

    A radial electron-beam-breakup transit-time oscillator (RBTO) provides a compact high power microwave generator. The RBTO includes a coaxial vacuum transmission line having an outer conductor and an inner conductor. The inner conductor defines an annular cavity with dimensions effective to support an electromagnetic field in a TEM.sub.00m mode. A radial field emission cathode is formed on the outer conductor for providing an electron beam directed toward the annular cavity electrode. Microwave energy is then extracted from the annular cavity electrode.

  8. North Atlantic Margins: Case studies of Magmatic Continental Breakup

    NASA Astrophysics Data System (ADS)

    Eccles, J. D.; White, R. S.; Christie, P. A. F.

    2012-04-01

    Continental breakup between Europe and Greenland was accompanied by the rapid eruption of the > 1 million cubic kilometres of extruded basalts forming North Atlantic Igneous Province. With episodes of extension in the region dating back to the Devonian, rifting finally proceeded to full breakup and oceanic spreading in the Paleocene. Flood basalt units flowed up to 150 km over pre-existing sedimentary basins, discrete volcanic centres formed and intrusion into the thinned continental crust occurred. Marine seismic investigations utilising industry-leading seismic reflection imaging technologies and large deployments of ocean bottom seismometers across the Faroes and Hatton Bank margins have been used to better resolve margin structure and composition, improving our understanding of breakup processes. Seismic reflection imaging reveals sub-aerial and submarine seaward-dipping reflector sequences tracking the interplay of uplift (transient and permanent), crustal loading through extrusion and ongoing extension. Lower crustal reflectors, cross-cutting the continental fabric and interpreted as intrusions, are observed within the narrow continent-ocean transition. P-wave tomography of wide-angle reflections and refractions, recorded to offsets of up to ~200 km, reveals unusually thick oceanic crust with lower crustal velocities in excess of those expected for MORB compositions. High P-wave velocities are attributed to magnesium-rich compositions which, combined with the large oceanic crustal thickness, would be consistent with an elevated mantle temperature (~150°C higher than 'normal') at the time of breakup. Vp/Vs ratios derived from tomography of converted shear wave phases also support high magnesium melt composition. P-wave velocities and Vp/Vs ratios across the continent-ocean transition show a mixing trend between magnesium-rich gabbroic compositions (100% for oceanic crust) and compositions consistent with the Lewisian gneiss basement or Early Proterozoic metamorphic basement of the Faroes and Hatton Bank areas respectively. Sedimentary units forming a low velocity zone beneath the flood basalts across the Faroe Ridge and into the Faroe-Shetland Trough are hypothesised to represent Paleocene sedimentary rock emplaced as transient thermal uplift across the nascent rift zone led to increased weathering and clastic sediment transport from Greenland.

  9. The Breakup of Temperature Inversions In Steep Valleys

    NASA Astrophysics Data System (ADS)

    Colette, A.; Street, R.

    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.

  10. Beam breakup simulation study for high energy ERL

    E-print Network

    Chen, Si; Nakamura, Norio; Huang, Senlin; Liu, Kexin; Chen, Jia-er

    2014-01-01

    The maximum beam current can be accelerated in an Energy Recovery Linac (ERL) can be severely limited by the transverse multi-pass beam breakup instability (BBU), especially in future ERL light sources with multi-GeV high energy beam energy and more than 100 mA average current. In this paper, the multi-pass BBU of such a high energy ERL is studied based on the simulation on a 3-GeV ERL light source proposed by KEK. It is expected to provide a reference to the future high energy ERL projects by this work.

  11. Beam breakup simulation study for a high energy ERL

    NASA Astrophysics Data System (ADS)

    Chen, Si; Shimada, M.; Nakamura, N.; Huang, Sen-Lin; Liu, Ke-Xin; Chen, Jia-Er

    2015-01-01

    The maximum beam current that can be accelerated in an energy recovery linac (ERL) can be severely limited by the transverse multi-pass beam breakup instability (BBU), especially in future ERL light sources with multi-GeV high energy beam energy and more than 100 mA average current. In this paper, the multi-pass BBU of such a high energy ERL is studied based on the simulation of a 3-GeV ERL light source that is proposed by KEK. This work is expected to provide a reference for future high energy ERL projects.

  12. The Davie Ridge: a Marginal Transform Ridge not Formed During Continental Breakup

    NASA Astrophysics Data System (ADS)

    Phethean, J. J. J.; Van Hunen, J.; McCaffrey, K. J. W.; Davies, R. J.

    2014-12-01

    The breakup of Gondwana translated Madagascar southwards relative to Africa along the Davie Fracture Zone (DFZ). This fracture zone now forms the Transform Passive Continental Margin (TPCM) from Kenya to Mozambique. The Davie Ridge (DR), a transform marginal ridge, has formed along the DFZ between 5 and 2°S and 22 and 11°S, but with little expression in-between. It has been proposed that this marginal ridge was formed by the thermal effects of a passing Mid Ocean Ridge (MOR) during the separation of Gondwana. Plate kinematic reconstructions, however, constrained by ocean magnetic anomalies, show that the MOR only passed between the north and south expressions of the DR. Therefore the positive linear gravity anomalies of the DR cannot be attributed to the effects of a passing MOR, and some other mechanism must be found to explain their formation. Interpretation of seismic reflection profiles along the DR shows that the gravity highs occur adjacent to large basin structures. In the north this correlates with a basin-bounding basement high of ~Albian age, and in the south with the rift flank uplifts of the currently active Quirimbas graben. This suggests that the northern and southern DR segments are instead shoulder uplifts resulting from two separate extensional episodes during different stress regimes. These are the Cretaceous NE-SW extension during the breakup of the south Atlantic, and the E-W extension of the Neogene-recent Afar-East Africa rift system, respectfully. The lack of deformation and DR formation along the region of the TPCM passed by the MOR suggests it has been coupled by thermal effects and/or the injection of magma.

  13. The effects of nozzle geometry on waterjet breakup at high Reynolds numbers

    Microsoft Academic Search

    H. Vahedi Tafreshi; B. Pourdeyhimi

    2003-01-01

    Waterjet breakup is traditionally considered to follow the Ohnesorge classification. In this classification, high Reynolds number waterjets are considered to atomize quickly after discharge. By generating a constricted waterjet where the water flow stays detached all the way through the nozzle, we have observed the first wind-induced breakup mode at high Reynolds numbers. Such a peculiar behavior, however, was not

  14. Correlation of empirical spacecraft breakup model's predictions with data from hypervelocity impact experiments

    Microsoft Academic Search

    Scott R. Maethner

    1993-01-01

    An accurate problem of the short and long term man-made orbital debris environment depends on the fidelity of spacecraft breakup models. These models provide post-breakup information for spacecraft collisions and explosions, including the number of fragments produced and the state vectors for each fragment. One way to verify the predictive capabilities of these models is to compare their predictions with

  15. Numerical Simulation of Droplet Breakup and Collision in the Solution Precursor Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Shan, Y.; Coyle, T. W.; Mostaghimi, J.

    2007-12-01

    Finely structured ceramic coatings can be obtained by solution precursor plasma spraying. The final structure of the coating highly depends on the droplet size and velocity distribution at the injection, the evolution of the spray in the jet, and droplet breakup and collision within the spray. This article describes a 3D model to simulate the transport phenomena and the trajectory and heating of the solution spray in the process. O’Rourke’s droplet collision model is used to take into account the influence of droplet collision. The influence of droplet breakup is also considered by implementing TAB droplet breakup models into the plasma jet model. The effects of droplet collisions and breakup on the droplet size, velocity, and temperature distribution of the solution spray are investigated. The results indicate that droplet breakup and collision play an important role in determining the final particle size and velocity distributions on the substrate.

  16. Near Term Effects from Satellite Break-Ups on Manned Space Activities

    NASA Technical Reports Server (NTRS)

    Theall, J. R.; Matney, M. J.

    2000-01-01

    Since 1961, almost 160 satellite break-ups have occurred on-orbit, and have been the major contributor to the growth of the orbital debris population. When a satellite breaks up, the debris exists in a relatively concentrated form, orbiting in a loose cloud with the parent body until orbital perturbations disperse the cloud into the average background. Manned space activities, which usually take place in low Earth orbit at altitudes less than 500 km, have been continuous for the past I I years while Mir was inhabited and promise to be again continuous when the International Space Station becomes permanently manned. This paper surveys historical breakups over the last I I years to determine the number that affect altitudes lower than 500 km. Selected breakup are analyzed using NASA's Satellite Breakup Risk Assessment Model (SBRAM) to determine the specific short term risk from those breakups to manned missions.

  17. Effect of the breakup context on unwanted pursuit behavior perpetration between former partners.

    PubMed

    De Smet, Olivia; Buysse, Ann; Brondeel, Ruben

    2011-07-01

    Former partners comprise the most important subgroup of stalkers. However, contextual factors related to the breakup are hardly examined to explain ex-partner pursuit. In a community sample of 194 separated persons, about one-fifth perpetrated at least one unwanted pursuit behavior in the past 2 weeks. Being female, lowly educated, and socially undesirable raised the number of perpetrated behaviors. Beyond these effects, the number of behaviors increased when the cause of the break was attributed to the ex-partner or external factors and when the ex was appraised as the breakup initiator. Breakup reasons, the ex-partner's lack in meeting family obligations and own infidelity, also related to pursuit behaviors albeit inferior to subjective attributions and appraisals of initiation. Finally, participants who felt more anxious or lonely negative showed more behaviors. The results enlighten that the breakup context gains further attention. Clinical treatment might benefit from fostering cognitive reconstructions and breakup adjustment. PMID:21470223

  18. Azimuthal structure of substorm breakup arcs prior to expansive phase onset using ISUAL/FORMOSAT-2

    NASA Astrophysics Data System (ADS)

    Chang, T.; Cheng, C.; Chiang, C.; Tam, S. W.; Chen, A. B.; Hsu, R.; Su, H.

    2008-12-01

    Substorm breakup arcs are investigated for substorm onset that occurs at the location of "Harang discontinuity" at pre-midnight. The auroral breakup arc images are obtained by the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) onboard FORMOSAT-2 satellite. We identify that the auroral breakup arc brightening occurs at the same time as the associated negative H-Bay and Pi 2 pulsations. It begins with a brightening on the arc and evolves into clear bead-like structure with approximate equally spaced separation along the arc direction. The enhanced auroral arcs finally break up into several parts. The azimuthal mode number of auroral breakup arcs prior to expansive phase onset ranges from ~200 to ~300. Based on the observations, we suggest that the substorm initial breakup arcs are consistent with kinetic ballooning instability, which is localized at the center of cross tail current sheet at about -(8-10) RE for strong substorms.

  19. Development of a droplet breakup model considering aerodynamic and droplet collision effects

    NASA Technical Reports Server (NTRS)

    Wert, K. L.; Jacobs, H. R.

    1993-01-01

    A model is currently under development to predict the occurrence and outcome of spray droplet breakup induced by aerodynamic forces and droplet collisions. It is speculated that these phenomena may be significant in determining the droplet size distribution in a spray subjected to acoustic velocity fluctuations. The goal is to integrate this breakup model into a larger spray model in order to examine the effects of combustion instabilities on liquid rocket motor fuel sprays. The model is composed of three fundamental components: a dynamic equation governing the deformation of the droplet, a criterion for breakage based on the amount of deformation energy stored in the droplet and an energy balance based equation to predict the Sauter mean diameter of the fragments resulting from breakup. Comparison with published data for aerodynamic breakup indicates good agreement in terms of predicting the occurrence of breakup. However, the model significantly over predicts the size of the resulting fragments. This portion of the model is still under development.

  20. Break-up dynamics of fluctuating liquid threads

    PubMed Central

    Petit, Julien; Rivière, David; Kellay, Hamid; Delville, Jean-Pierre

    2012-01-01

    The thinning dynamics of a liquid neck before break-up, as may happen when a drop detaches from a faucet or a capillary, follows different rules and dynamic scaling laws depending on the importance of inertia, viscous stresses, or capillary forces. If now the thinning neck reaches dimensions comparable to the thermally excited interfacial fluctuations, as for nanojet break-up or the fragmentation of thermally annealed nanowires, these fluctuations should play a dominant role according to recent theory and observations. Using near-critical interfaces, we here fully characterize the universal dynamics of this thermal fluctuation-dominated regime and demonstrate that the cross-over from the classical two-fluid pinch-off scenario of a liquid thread to the fluctuation-dominated regime occurs at a well-defined neck radius proportional to the thermal length scale. Investigating satellite drop formation, we also show that at the level of the cross-over between these two regimes it is more probable to produce monodisperse droplets because fluctuation-dominated pinch-off may allow the unique situation where satellite drop formation can be inhibited. Nonetheless, the interplay between the evolution of the neck profiles from the classical to the fluctuation-dominated regime and the satellites’ production remains to be clarified. PMID:23090994

  1. Distribution of living Cupressaceae reflects the breakup of Pangea

    PubMed Central

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

    2012-01-01

    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. PMID:22550176

  2. Effects of bubble coalescence and breakup on conduit dynamics

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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 in a shear flow (conduit flow) below the fragmentation level. We use a 3D multiphase lattice Boltzmann model to investigate the dynamics at the scale of the bubbles. The net coalescence rate and evolution of the bubble size distribution and number density depend exponentially on the capillary number, Ca (ratio of shear forces to surface tension forces). The Bond number (ratio of buoyancy force to surface tension force) also influences breakup dynamics at large Ca. The results obtained from our 3D lattice Boltzmann model are used to develop a parameterization for the evolution of both bubble size distribution and number density. This parameterization is then used as a model for subgrid scale processes in a 2D conduit model in which the bubbly fluid is treated as a continuum. Our bubble-scale dynamics model can also be used to quantify the development of permeability as bubbles coalesce and connect with the fragmentation surface. We use this multiscale approach to investigate the eruption dynamics of the mafic andesite eruptions that have recently occurred at Tungurahua volcano, Ecuador

  3. Deformation and breakup of viscoelastic droplets in confined shear flow.

    PubMed

    Gupta, A; Sbragaglia, M

    2014-08-01

    The deformation and breakup of Newtonian and viscoelastic droplets are studied in confined shear flow. Our numerical approach is based on a combination of lattice-Boltzmann models and finite difference schemes, the former used to model two immiscible fluids with variable viscosity ratio and the latter used to model the polymer dynamics. The kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible nonlinear elastic dumbbells with Peterlin's closure. We quantify the droplet response by changing the polymer relaxation time ?(P), the maximum extensibility L of the polymers, and the degree of confinement, i.e., the ratio of the droplet diameter to wall separation. In unconfined shear flow, the effects of droplet viscoelasticity on the critical capillary number Ca(cr) for breakup are moderate in all cases studied. However, in confined conditions a different behavior is observed: The critical capillary number of a viscoelastic droplet increases or decreases, depending on the maximum elongation of the polymers, the latter affecting the extensional viscosity of the polymeric solution. Force balance is monitored in the numerical simulations to validate the physical picture. PMID:25215849

  4. BREAK-UP DATES OF ALPINE LAKES AS PROXY DATA FOR LOCAL AND REGIONAL MEAN SURFACE AIR TEMPERATURES

    E-print Network

    Livingstone, David M.

    BREAK-UP DATES OF ALPINE LAKES AS PROXY DATA FOR LOCAL AND REGIONAL MEAN SURFACE AIR TEMPERATURES. The calendar date of ice break-up on Lej da San Murezzan, a high-altitude (1768 m a.s.l.) lake in the Swiss records from two neighbouring lakes, the potential use of the timing of spring break-up as a proxy

  5. Neutron structure effects in the deuteron and one neutron halos

    E-print Network

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

    2006-08-29

    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, $F_1^{(n)} (q^2)$ and $F_2^{(n)} (q^2)$, lead to an electromagnetic potential of the neutron. Using this fact, we calculate the electromagnetic corrections to the binding energy, $B_d$, of the deuteron and a one neutron halo nucleus (11Be), by evaluating the neutron-proton and the neutron-charged core (10Be) potential, respectively. The correction to $B_d$ (~9 keV) is comparable to that arising due to the inclusion of the $\\Delta$-isobar component in the deuteron wave function. In the case of the more loosely bound halo nucleus, 11Be, the correction is close to about 2 keV.

  6. Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST

    SciTech Connect

    Zhang, C.; Akdogan, T.; Bertozzi, W.; Botto, T.; Clasie, B.; DeGrush, A.; Dow, K.; Farkhondeh, M.; Franklin, W.; Gilad, S.; Hasell, D.; Kolster, H.; Maschinot, A.; Matthews, J.; Meitanis, N.; Milner, R.; Redwine, R.; Seely, J.; Shinozaki, A.; Tschalaer, C. [Laboratory for Nuclear Science and Bates Linear Accelerator Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2011-12-16

    We report a precision measurement of the deuteron tensor analyzing powers T{sub 20} and T{sub 21} at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50 fm{sup -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 G{sub C} and G{sub Q} were separated with improved precision, and the location of the first node of G{sub C} was confirmed at Q=4.19{+-}0.05 fm{sup -1}. The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T{sub 20} and the first node of G{sub C}.

  7. Sonofusion: Squeezed Deuteron Clusters, With Small Size, High Energy Density but No High Energy Particles

    NASA Astrophysics Data System (ADS)

    Stringham, Roger

    2009-03-01

    Inertial confined fusion when viewed as a natural process compares with sonofusion's electromagnetically squeezed deuteron cluster. Sonofusion capitalizes on its very small size and its higher energy densities. It is a relatively cool process, with the endothermic removal of heat, 13.6 ev, from a target implanted with clusters of deuterons; the fusion environment. The energy densities approach those of the deuteron sepaaration in muon DD fusion. This helps explain sonofusion's experimental results of heat and helium four.

  8. Deuteron Spin Structure Functions in the Resonance and DIS Regions

    SciTech Connect

    S. Kulagin; W. Melnitchouk

    2007-10-03

    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.

  9. Single and Double Pion Photoproduction off the Deuteron

    E-print Network

    Manuel Dieterle

    2011-08-31

    There is evidence that the photoproduction of single and double pions off bound nucleons inside a nucleus are not only affected by Fermi motion but also by other nuclear effects, such as final state interactions or meson rescattering. We will present preliminary results of a high statistics measurement of single and double pion photoproduction of quasi-free protons and neutrons off the deuteron carried out at the Mainzer Microtron.

  10. Theoretical study of incoherent ? photoproduction on a deuteron target

    NASA Astrophysics Data System (ADS)

    Sekihara, T.; Martínez Torres, A.; Jido, D.; Oset, E.

    2012-01-01

    We study the photoproduction of ? mesons in deuteron, paying attention to the modification of the cross-section from bound protons to the free ones. For this purpose we take into account Fermi motion in single scattering and rescattering of ? to account for ? absorption on a second nucleon as well as the rescattering of the proton on the neutron. We find that the contribution of the double scattering for ? is much smaller than the typical cross-section of ? p ? ? p in free space, which implies a very small screening of the ? production in deuteron. The contribution from the proton rescattering, on the other hand, is found to be not negligible compared to the cross-section of ? p ? ? p in free space, and leads to a moderate reduction of the ? photoproduction cross-section on a deuteron at forward angles if the LEPS set-up is taken into account. The Fermi motion allows contribution of the single scattering in regions forbidden by phase-space in the free case. In particular, we find that for momentum transfer squared close to the maximum value, the Fermi motion changes drastically the shape of d?/d t, to the point that the ratio of this cross-section to the free one becomes very sensitive to the precise value of t chosen, or the size of the bin used in an experimental analysis. Hence, this particular region of t does not seem to be the most indicated to find effects of a possible ? absorption in the deuteron. This reaction is studied theoretically as a function of t and the results are contrasted with recent experiments at LEPS and Jefferson Lab. The effect of the experimental angular cuts at LEPS is also discussed, providing guidelines for future experimental analyses of the reaction.

  11. Light Front Field Theory Calculation of Deuteron Properties

    NASA Astrophysics Data System (ADS)

    Cooke, Jason R.

    2001-12-01

    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.

  12. Deuteron and triton production with high energy sulphur and lead beams

    NASA Astrophysics Data System (ADS)

    Bearden, I. G.; Bøggild, H.; Boissevain, J.; Christiansen, P. H. L.; Conin, L.; Dodd, J.; Erazmus, B.; Esumi, S.; Fabjan, C. W.; Ferenc, D.; Franz, A.; Gaardhøje, J. J.; Hansen, A. G.; Hansen, O.; Hardtke, D.; van Hecke, H.; Holzer, E. B.; Humanic, T. J.; Hummel, P.; Jacak, B. V.; Kaimi, K.; Kaneta, M.; Kohama, T.; Kopytine, M.; Leltchouk, M.; Ljubi?i?, A., Jr.; Lörstad, B.; Martin, L.; Medvedev, A.; Murray, M.; Ohnishi, H.; Pai?, G.; Pandey, S. U.; Piuz, F.; Pluta, J.; Polychronakos, V.; Potekhin, M.; Poulard, G.; Reichhold, D.; Sakaguchi, A.; Schmidt-Sørensen, J.; Simon-Gillo, J.; Sondheim, W.; Sugitate, T.; Sullivan, J. P.; Sumi, Y.; Willis, W. J.; Wolf, K.; Xu, N.; Zachary, D. S.

    2002-03-01

    Proton and deuteron production has been observed in S+S and S+Pb collisions at 200 A\\cdotGeV and in Pb+Pb reactions at 158 A\\cdotGeV at the CERN SPS accelerator. For Pb+Pb triton production was also measured. The p and d spectra as well as the p and t spectra were observed in similar rapidity ranges and over similar ranges of transverse momenta per nucleon, making it possible to interpret the cross sections of the composite particles in terms of coalescence mechanisms. Volumes of homogeneity were extracted and compared to pion-pair HBT interferometry results. Special attention is given to the dependence on transverse mass, centrality and rapidity.

  13. Covariant spectator theory of np scattering: Deuteron magnetic moment

    NASA Astrophysics Data System (ADS)

    Gross, Franz

    2014-06-01

    The deuteron magnetic moment is calculated using two model wave functions obtained from 2007 high-precision fits to np scattering data. Included in the calculation are a new class of isoscalar np interaction currents, which are automatically generated by the nuclear force model used in these fits. After normalizing the wave functions, nearly identical predictions are obtained: model WJC-1, with larger relativistic P-state components, gives 0.863(2), while model WJC-2 with very small P-state components gives 0.864(2). These are about 1% larger than the measured value of the moment, 0.857 n.m., giving a new CST prediction for the size of the ??? exchange, and other purely transverse interaction currents that are largely unconstrained by the nuclear dynamics. The physical significance of these results is discussed, and general formulas for the deuteron form factors, expressed in terms of deuteron wave functions and a new class of interaction current wave functions, are given.

  14. Nuclear physics in soft-wall AdS/QCD: Deuteron electromagnetic form factors

    E-print Network

    Thomas Gutsche; Valery E. Lyubovitskij; Ivan Schmidt; Alfredo Vega

    2015-06-02

    We present a high-quality description of the deuteron electromagnetic form factors in a soft-wall AdS/QCD approach. We first propose an effective action describing the dynamics of the deuteron in the presence of an external vector field. Based on this action the deuteron electromagnetic form factors are calculated, displaying the correct 1/Q^10 power scaling for large Q^2 values. This finding is consistent with quark counting rules and the earlier observation that this result holds in confining gauge/gravity duals. The Q^2 dependence of the deuteron form factors is defined by a single and universal scale parameter kappa, which is fixed from data.

  15. Simulation of dependence of the cross section of deuterons beam fragmentation into cumulative pions and protons on the mass of the target nucleus

    NASA Astrophysics Data System (ADS)

    Litvinenko, A. G.; Litvinenko, E. I.

    2015-03-01

    We have studied the mechanisms influencing production of cumulative pions and protons in the fragmentation of the incident deuterons into cumulative pions and protons emitted at zero angle. We argue that the peripheral dependence on the atomic mass of the target nucleus, which was obtained in the experiments for medium and heavy nuclei, can be explained by scattering on target nucleons without introducing additional parameters.

  16. Evidence of recent warming and El Nino-related variations in ice breakup of Wisconsin lakes

    USGS Publications Warehouse

    Anderson, W.L.; Robertson, D.M.; Magnuson, J.J.

    1996-01-01

    Ice breakup dates from 1968 to 1988 were examined for 20 Wisconsin lakes to determine whether consistent interannual and long-term changes exist. Each ice record had a trend toward earlier breakup dates, as demonstrated by a negative slope with time, indicating a recent warming trend. The average change in breakup dates was 0.82 d earlier per year for the lakes in southern Wisconsin, which was more extreme than that for the northern Wisconsin lakes (0.45 d yr-1). Interannual variation in breakup dates was related to the warm phase of El Nino/Southern Oscillation (ENSO) episodes. El Nino events occurred five times during this period (1965, 1972, 1976, 1982, and 1986). Average breakup dates were significantly earlier than average (5-14 d) during the mature phase of El Nino. This variability was affected by the location of the lake: El Nino-related variation was more evident for the southern lakes than the northern lakes. This difference was caused by the average date of breakup for the southern lakes being in late March directly following the period when air temperatures were strongly related to El Nino events, whereas the average dates of breakup of the northern lakes was in mid- to late April following a period when air temperatures were not significantly related to El Nino events. Overall, the interannual and long-term patterns across Wisconsin were relatively consistent, indicating that recent warming and El Nino- related variation are regional climatic responses.

  17. From conjugate volcanic rifted margins to micro-continent formation: Double breakup development of the Norwegian-Greenland Sea

    NASA Astrophysics Data System (ADS)

    Gernigon, Laurent; Blischke, Anett; Nasuti, Aziz; Olesen, Odleiv; Sand, Morten; Sveinn Arnarson, Thorarinn

    2014-05-01

    We re-evaluate the structure and spreading evolution of the Norwegian-Greenland Sea and surrounding volcanic (rifted) margins based on new high-resolution aeromagnetic surveys. The new dataset combined with long-offset seismic and gravity data allow us to have a better understanding of the structure and evolution of the conjugate margin systems in the Norwegian-Greenland Sea from the rifting to the drifting stage. We particularly focus on the new JAS-12 aeromagnetic survey acquired between the Aegir Ridge and the Jan Mayen micro-continent, which was initially part of the Møre-Vøring-Greenland rift system. Combined with the previous NB-07 and JAS-05 surveys, our final compilation fully covers the continent-ocean transition and the whole oceanic spreading system from the Møre margin to the conjugate Jan Mayen micro-continent with high quality, high-resolution and reliable magnetic data. The new dataset allowed a new, consistent and precise interpretation of the magnetic polarity chrons and oceanic fractures, providing the basis for more accurate rotation poles estimation, and better basin and crustal reconstructions between Norway, Greenland and the Jan Mayen micro-continent. This dataset allowed us to clarify the pre- and post-breakup configurations of the rift system and discuss the mechanisms involved during the onset of the two phases of breakup leading to the micro-continent formation. Our observations and models suggest that the pre-breakup rift system evolved through a significant Late Jurassic-Cretaceous thinning phase. This episode led to a significant thinning of the continental crust and an exhumation of pre-existing lower crust. However, we have not been able to identify and/or validate any clear domains of exhumed and denudated serpentinised mantle. The first Eocene breakup is mostly characterised by severe magmatism (sill, SDRS). Lithospheric/asthenospheric processes leading to rift localisation do not necessarily represent a continuum of lithospheric deformation with the precedent thinning system. Diking and disconnected lithospheric plumbing are proposed to explain the Eocene breakup. After the first phase of continental breakup, two major phases of spreading influenced the Norwegian-Greenland Sea. Phase I (from C24 to C21r, ~54 to 49 Ma) marks the earliest phase of spreading, probably initiated in the central and outer part of the Møre Basin. During this period, the formation of overlapping systems and pseudo-fault development, indirectly influenced by the proto-margin segmentation, suggests the presence of additional micro-plates in the Norwegian-Greenland Sea. We also observed a significant change in the oceanic spreading system in the late Early Eocene. Based on observations from the surrounding areas, this supports a major and distinct tectonic and magmatic event in the Norwegian-Greenland Sea at around C21r (49-47.9 Ma), the beginning of a second phase. During Phase II, from C21r-C12 or possibly younger (48-<32 Ma) of the Norway Basin development, spreading rates decreased, spreading direction changed leading to the formation of unexpected N-S oriented oceanic fracture zones. Phase II probably coincides with the climax of extension and possibly local spreading that is suspected in the southern part of the Jan Mayen micro-continent forming a complex area of oceanic, transitional and continental fragments before its complete dislocation from East Greenland in Latest Oligocene.

  18. Status of breakup reaction theory K Ogata1, T Matsumoto2,3, S Hashimoto4, K Minomo1, T Egami1,

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    -0021, Japan 6 Physics Division, Kyushu Dental College, Kitakyushu 803-8580, Japan 7 Department of Physics breakup, microscopic description of projectile breakup processes, description of ternary processes (new relativistic effects on Coulomb breakup, iii. microscopic description of projectile breakup processes, iv

  19. Breakup Threshold Anomaly: New Manifestation of the Dispersion Relation

    E-print Network

    M. S. Hussein; P. R. S. Gomes; J. Lubian; L. C. Chamon

    2007-04-23

    It is pointed out that the usual threshold anomaly, found operative in the energy behavior of the imaginary and real parts of the optical potential representing the elastic scattering of tightly bound nuclei at near- and below-barrier energies, suffers a drastic qualitative change in the case of the elastic scattering of weakly bound nuclei. Owing to the strong coupling to the breakup channel even at sub-barrier energies, the imaginary potential strength seems to increase as the energy is lowered down to below the natural, barrier, threshold, accompanied by a decrease in the real potential strength. This feature is consistent with the dispersion relation. The system $^{6}$Li + $^{208}$Pb is analyzed to illustrate this new phenomenon.

  20. Inversion Breakup in Small Rocky Mountain and Alpine Basins

    SciTech Connect

    Whiteman, Charles D.; Pospichal, Bernhard; Eisenbach, Stefan; Weihs, P.; Clements, Craig B.; Steinacker, Reinhold; Mursch-Radlgruber, Erich; Dorninger, Manfred

    2004-08-01

    Comparisons are made between the post-sunrise breakup of temperature inversions in two similar closed basins in quite different climate settings, one in the eastern Alps and one in the Rocky Mountains. The small, high-altitude, limestone sinkholes have both experienced extreme temperature minima below -50°C. On undisturbed clear nights, temperature inversions reach to 120 m heights in both sinkholes, but are much stronger in the drier Rocky Mountain basin (24K versus 13K). Inversion destruction takes place 2.6 to 3 hours after sunrise and is accomplished primarily by subsidence warming associated with the removal of air from the base of the inversion by the upslope flows that develop over the sidewalls. Differences in inversion strengths and post-sunrise heating rates are caused by differences in the surface energy budget, with drier soil and a higher sensible heat flux in the Rocky Mountain sinkhole.

  1. Inadvertent Earth Reentry Breakup Analysis for the New Horizons Mission

    NASA Technical Reports Server (NTRS)

    Ling, Lisa M.; Salama, Ahmed; Ivanov, Mark; McRonald, Angus

    2007-01-01

    The New Horizons (NH) spacecraft was launched in January 2006 aboard an Atlas V launch vehicle, in a mission to explore Pluto, its moons, and other bodies in the Kuiper Belt. The NH spacecraft is powered by a Radioisotope Thermoelectric Generator (RTG) which encases multiple General Purpose Heat Source (GPHS) modules. Thus, a pre-launch vehicle breakup analysis for an inadvertent atmospheric reentry in the event of a launch failure was required to assess aerospace nuclear safety and for launch contingency planning. This paper addresses potential accidental Earth reentries analyzed at the Jet Propulsion Laboratory (JPL) which may arise during the ascent to parking orbit, resulting in a suborbital reentry, as well as a departure from parking orbit, resulting in an orbital reentry.

  2. Regenerative multi-pass beam breakup in two dimensions

    SciTech Connect

    Eduard Pozdeyev

    2004-12-01

    In this paper, a formula, describing a threshold of the regenerative multi-pass Beam Breakup (BBU) for a single dipole higher order mode with arbitrary polarization in a two-pass accelerator with a general-form, 4x4 recirculation matrix, is derived. Also a new two-dimensional BBU code is introduced. To illustrate specifics of the BBU in two dimensions, the formula is used to calculate the threshold in several cases including two-dimensional uncoupled optics, reflecting optics, and rotating optics. The analytical results are compared to results of simulation obtained with the new code. At the end of the paper, a mathematical relation between transfer matrices between cavities of the accelerating structure and recirculation matrices for each cavity, which must be satisfied in order to successfully suppress the BBU by reflection or rotation in several cavities, is presented.

  3. Flow bursts, breakup arc, and substorm current wedge

    NASA Astrophysics Data System (ADS)

    Haerendel, Gerhard

    2015-04-01

    Energy liberated by the reconnection process in the near-Earth tail is transported via flow bursts toward the dipolar magnetosphere during substorms. The breakup arc is a manifestation of the arrival of the bursts under flow braking and energy deposition. Its structure and behavior is analyzed on the basis of five striking spatial, temporal, and energetic properties, qualitatively and in part also quantitatively. A key element is the formation of stop layers. They are thin layers, of the width of an ion gyro radius, in which the magnetic field makes a transition from tail to near-dipolar magnetosphere configurations and in which the kinetic energy of fast flows is converted into electromagnetic energy of kinetic Alfvén waves. The flows arise from the relaxation of the strong magnetic shear stresses in the leading part of the flow bursts. The bright narrow arcs of less than 10 km width inside the broad poleward expanding breakup arc, Alfvénic in nature and visually characterized by erratic short-lived rays, are seen as traces of the stop layers. The gaps between two narrow and highly structured arcs are filled with more diffuse emissions. They are attributed to the relaxation of the less strained magnetic field of the flow bursts. Eastward flows along the arcs are linked to the shrinking gaps between two successive arcs and the entry of auroral streamers into the dipolar magnetosphere in the midnight sector. Flow braking in the stop layers forms multiple pairs of narrow balanced currents and cannot be behind the formation of the substorm current wedge. Instead, its origin is attributed to the force exerted by the dipolarized magnetic field of the flow bursts on the high-beta plasma, after the high magnetic shears have relaxed and the fast flows and stop layer process have subsided, in other words, to the "dying flow bursts."

  4. Coulomb breakup of 37Mg and its ground state structure

    NASA Astrophysics Data System (ADS)

    Shubhchintak; Neelam; Chatterjee, R.; Shyam, R.; Tsushima, K.

    2015-07-01

    We calculate Coulomb breakup of the neutron rich nucleus 37Mg on a Pb target at the beam energy of 244 MeV /nucleon within the framework of a finite range distorted wave Born approximation theory that is extended to include the effects of projectile deformation. In this theory, the breakup amplitude involves the full wave function of the projectile ground state. Calculations have been carried out for the total one-neutron removal cross section (?-1n), the neutron-core relative energy spectrum, the parallel momentum distribution of the core fragment, the valence neutron angular, and energy-angular distributions. The calculated ?-1n has been compared with the recently measured data to put constraints on the spin parity, and the one-neutron separation energy (Sn) of the 37Mg ground state (37Mggs). The dependence of ?-1n on the deformation of this state has also been investigated. While a spin parity assignment of 7 /2- for the 37Mggs is ruled out by our study, neither of the 3 /2- and 1 /2+ assignments can be clearly excluded. Using the spectroscopic factor of one for both the 3 /2- and 1 /2+ configurations and ignoring the projectile deformation effects, the Sn values of 0.35 ± 0.06 MeV and 0.50 ± 0.07 MeV, respectively, are extracted for the two configurations. However, the extracted Sn is strongly dependent on the spectroscopic factor and the deformation effects of the respective configuration. The narrow parallel momentum distribution of the core fragment and the strong forward peaking of the valence neutron angular distribution suggest a one-neutron halo configuration in either of the 2p3/2 and 2s1/2 configurations of the 37Mg ground state.

  5. Systematic measurement of pd breakup cross section at quasi-free scattering

    NASA Astrophysics Data System (ADS)

    Eguchi, Y.; Sagara, K.; Kuroita, S.; Yashima, K.; Shishido, T.; Yabe, T.; Ishikawa, S.

    2010-04-01

    Space Star (SS) anomaly in Nd breakup cross section is well known. SS anomaly has large charge asymmetry; exp eriment is larger than calculation at nd SS and exp eriment is smaller than calculation at pd SS. There are also rep orts on anomaly in quasi-free scattering (QFS) cross section in Nd breakup reaction. At nd QFS, exp erimental cross section was found to be larger than calculation. On the contrary, pd QFS cross section measured by Köln group is smaller than pd calculation. We measured QFS cross section in pd breakup reaction, and compared the data with recent pd calculations to see angular dep endence of QFS anomaly.

  6. Breakup dynamics of Non-Newtonian droplets in microfluidic devices: From necking to Rupture

    NASA Astrophysics Data System (ADS)

    Boukany, Pouyan; Sachdev, Shaurya

    2015-03-01

    It has been shown that addition of small amounts of polymers to a Newtonian fluid can exhibit non-Newtonian behavior in extensional flows. For instance, polymeric fluids produce strong filament thinning called necking when subjected to extensional flows. Coiled polymeric chains are expected to be stretched in this exponential necking regime. These stretched long chains induce elastic stress that resist the capillary forces trying to break the filament apart. Still, the molecular picture behind filament thinning and rupture of polymeric threads in extensional flow conditions is unknown. In this work, we study breakup and filament thinning of micro-droplets containing polymeric suspensions by using micro-fluidic devices. To reveal the underlying mechanism of thinning and rupture of polymeric filament, conformation of DNA suspensions were visualized in different flow conditions. Experiments have been done on both dilute and concentrated polymeric solutions. These new results allow us to pinpoint the molecular mechanism behind filament thinning and flow instabilities in strong extensional flows of polymeric fluids.

  7. D-Cluster Converter Foil for Laser-Accelerated Deuteron Beams: Towards Deuteron-Beam-Driven Fast Ignition

    SciTech Connect

    Miley, George H.

    2012-10-24

    Fast Ignition (FI) uses Petawatt laser generated particle beam pulse to ignite a small volume called a pre-compressed Inertial Confinement Fusion (ICF) target, and is the favored method to achieve the high energy gain per target burn needed for an attractive ICF power plant. Ion beams such as protons, deuterons or heavier carbon ions are especially appealing for FI as they have relative straight trajectory, and easier to focus on the fuel capsule. But current experiments have encountered problems with the 'converter-foil' which is irradiated by the Petawatt laser to produce the ion beams. The problems include depletion of the available ions in the convertor foils, and poor energy efficiency (ion beam energy/ input laser energy). We proposed to develop a volumetrically-loaded ultra-high-density deuteron deuterium cluster material as the basis for converter-foil for deuteron beam generation. The deuterons will fuse with the ICF DT while they slow down, providing an extra 'bonus' energy gain in addition to heating the hot spot. Also, due to the volumetric loading, the foil will provide sufficient energetic deuteron beam flux for 'hot spot' ignition, while avoiding the depletion problem encountered by current proton-driven FI foils. After extensive comparative studies, in Phase I, high purity PdO/Pd/PdO foils were selected for the high packing fraction D-Cluster converter foils. An optimized loading process has been developed to increase the cluster packing fraction in this type of foil. As a result, the packing fraction has been increased from 0.1% to 10% - meeting the original Phase I goal and representing a significant progress towards the beam intensities needed for both FI and pulsed neutron applications. Fast Ignition provides a promising approach to achieve high energy gain target performance needed for commercial Inertial Confinement Fusion (ICF). This is now a realistic goal for near term in view of the anticipated ICF target burn at the National Ignition Facility (NIF) in CA within a year. This will usher in the technology development Phase of ICF after years of research aimed at achieving breakeven experiment. Methods to achieve the high energy gain needed for a competitive power plant will then be a key developmental issue, and our D-cluster target for Fast Ignition (FI) is expected to meet that need.

  8. Breakup of an oil slick mixed with dispersants by breaking wave

    NASA Astrophysics Data System (ADS)

    Li, Cheng; Holser, Anne; Katz, Joseph

    2013-11-01

    After oil spill, coherent oil slick are entrained by breaking ocean waves together with air, which produces a complicated three-phase flow, involving a wide range of length and time scales. The oil droplet size distribution is a crucial factor affecting the physical and chemical dispersion of oil spills, but little is known about oil droplet formation mechanism and droplet size distributions during and immediately after the impact of breaking waves. In our experimental study, we investigate the breakup of an oil slick in a specialized wave tank. The widely used dispersant Coexist 9500-A at different dispersant to oil ratio is used for varying the surface tension of crude oil (MC252 surrogate) in the 10 - 1 to 10 mN/m range. The dispersant is applied either by premixing or surface spraying, the latter consistent with typical application. The results include high-speed images of the oil and bubbles' entrainment, showing the resulting formation of a series of droplet clouds during multiple ``plunges'' associated with a single propagating breaking wave. High-speed inline digital holographic cinematography is employed to quantify the oil droplet size distribution, and the impact of droplet-bubble interactions on the entrainment process for varying Weber numbers, and wave properties, from spilling to plunging breakers. After oil spill, coherent oil slick are entrained by breaking ocean waves together with air, which produces a complicated three-phase flow, involving a wide range of length and time scales. The oil droplet size distribution is a crucial factor affecting the physical and chemical dispersion of oil spills, but little is known about oil droplet formation mechanism and droplet size distributions during and immediately after the impact of breaking waves. In our experimental study, we investigate the breakup of an oil slick in a specialized wave tank. The widely used dispersant Coexist 9500-A at different dispersant to oil ratio is used for varying the surface tension of crude oil (MC252 surrogate) in the 10 - 1 to 10 mN/m range. The dispersant is applied either by premixing or surface spraying, the latter consistent with typical application. The results include high-speed images of the oil and bubbles' entrainment, showing the resulting formation of a series of droplet clouds during multiple ``plunges'' associated with a single propagating breaking wave. High-speed inline digital holographic cinematography is employed to quantify the oil droplet size distribution, and the impact of droplet-bubble interactions on the entrainment process for varying Weber numbers, and wave properties, from spilling to plunging breakers. Supported by Gulf of Mexico Research Initiative (GoMRI).

  9. POMME: A medium energy deuteron polarimeter based on semi-inclusive ?-carbon scattering

    NASA Astrophysics Data System (ADS)

    Bonin, B.; Boudard, A.; Fanet, H.; Fergerson, R. W.; Garçon, M.; Giorgetti, C.; Habault, J.; Le Meur, J.; Lombard, R. M.; Lugol, J. C.; Mayer, B.; Mouly, J. P.; Tomasi-Gustafsson, E.; Duchazeaubeneix, J. C.; Yonnet, J.; Morlet, M.; Van de Wiele, J.; Willis, A.; Greeniaus, G.; Gaillard, G.; Markowitz, P.; Perdrisat, C. F.; Abegg, R.; Hutcheon, D. A.

    1990-03-01

    POMME is the first calibrated deuteron polarimeter using a d + carbon semi-inclusive scattering reaction. We present the results of its calibration in the region Td = 150-700 MeV, with the polarized deuteron beam from the synchrotron Saturne. A parametrization of the measured analyzing powers, and a discussion of the obtained efficiency and figure of merit are also given.

  10. Gluon distribution at moderately low-x from NMC deuteron structure function data

    E-print Network

    Sarma, J K

    2002-01-01

    We present some simple methods to find gluon distribution from analysis of deuteron F_{2} structure function data at moderately low-x. Here we use the leading order(LO) Altarelli -Parisi(AP) evolution equation and New Muon Collaboration (NMC) deuteron F_{2} structure function data to extract gluon distribution. We also compare our results with those of other authors.

  11. Modern Studies of the Deuteron: from the Lab Frame to the Light Front

    E-print Network

    Werner Boeglin; Misak Sargsian

    2015-03-30

    We review the recent progress made in studies of deuteron structure at small internucleon distances. This progress is largely facilitated by the new generation of experiments in deuteron electrodisintegration carried out at unprecedentedly high momentum transfer. The theoretical analysis of these data confirms the onset of the high energy eikonal regime in the scattering process which allows one to separate long range nuclear effects from the effects genuinely related to the short distance structure of the deuteron. Our conclusion is that for the first time the deuteron is probed at relative momenta beyond 300 MeV/c without dominating long range effects. As a result, at these large nucleon momenta the cross section is sensitive to the nuclear dynamics at sub-fermi distances. Due to large internal momenta involved we are dealing with the relativistic bound state that is best described by the light-cone momentum distribution of nucleons in the deuteron. We present the first attempt of extracting the deuteron light-cone momentum distribution function from data and discuss the importance of this quantity for studies of QCD structure of the bound nucleon in deep inelastic scattering off the deuteron. We conclude the review giving an outlook of the next generation of high energy experiments which will extend our reach to much smaller distances in the deuteron.

  12. Investigation of the deuteron spin structure at short nucleon-nucleon distances in the reaction of polarized-deuteron fragmentation to cumulative pions

    SciTech Connect

    Azhgirey, L. S.; Afanasiev, S. V.; Borzounov, Yu. T.; Golovanov, L. B.; Zolin, L. S., E-mail: zolin@sunhe.jinr.ru; Ivanov, V. I.; Isupov, A. Yu., E-mail: isupov@moonhe.jinr.ru; Ladygin, V. P.; Litvinenko, A. G.; Malakhov, A. I.; Penev, V. N.; Peresedov, V. F.; Pilipenko, Yu. K.; Reznikov, S. G.; Rukoyatkin, P. A.; Khrenov, A. N. [Joint Institute for Nuclear Research (Russian Federation)

    2011-10-15

    Experimental results on the vector (A{sub y}) and tensor (A{sub yy}) analyzing powers in the fragmentation of 5- and 9-GeV/c polarized deuterons to high-momentum pions in the kinematical region corresponding to pion production on a strongly correlated nucleon pair (cumulative meson production) are presented. The angular and momentum dependences of A{sub yy} are not described by calculations performed in the impulse approximation by using standard deuteron wave functions. An explanation for our data should be sought on the basis of models that treat the deuteron at short distances (deuteron-core region) as a multiquark state-for example, a 6q cluster, whose high orbital angular momentum (D wave) leads to the observed strong dependence of the reaction tensor analyzing power A(d-vector, {pi})X on the pion transverse momentum.

  13. Coherent ?+ and ?(1520) photoproduction off the deuteron

    NASA Astrophysics Data System (ADS)

    Titov, A. I.; Kämpfer, B.; Daté, S.; Ohashi, Y.

    2005-09-01

    We analyze coherent ?+?(1520) photoproduction in the ?d interaction near the threshold. We demonstrate that the effect of the coherent production becomes manifest in a comparison of the nK+ invariant mass distribution when the pK- system is on the ?(1520) mass. Our model calculations indicate a sizable contribution of resonant and nonresonant background processes in the ?d?npK+K- reaction that generally exceeds the contribution of the coherent resonance channel. However, we find that coherent ?+?(1520) photoproduction is enhanced relative to the background processes in the forward hemisphere of pK- pair photoproduction. Moreover, the coherence effect does not depend on the ?+ photoproduction amplitude and is defined by the probabilities of ?(1520) photoproduction and the ?+?NK transition. Therefore, this effect may be used as an independent method for studying the production mechanism and properties of ?+.

  14. Facing a breakup: Electromyographic responses moderate self-concept recovery following a romantic separation

    PubMed Central

    MASON, ASHLEY E.; LAW, RITA W.; BRYAN, AMANDA E. B.; PORTLEY, ROBERT M.; SBARRA, DAVID A.

    2015-01-01

    Romantic breakups arouse fundamental questions about the self: Who am I without my partner? This study examined self-concept reorganization and psychological well-being over an 8-week period in the months following a breakup. Multilevel analyses revealed that poorer self-concept recovery preceded poorer well-being and was associated with love for an ex-partner, suggesting that failure to redefine the self contributes to post-breakup distress. Psychophysiological data revealed that greater activity in the corrugator supercilia facial muscle while thinking about an ex-partner predicted poorer self-concept recovery and strengthened the negative association between love for an ex-partner and self-concept recovery. Thus, the interaction between self-report and psychophysiological data provided information about the importance of self-concept recovery to post-breakup adjustment not tapped by either method alone.

  15. ISS Update: ATV-3 ReEntry Breakup Recorder - Duration: 11 minutes.

    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 Europ...

  16. Break-up of two-dimensional bright spatial solitons due to transverse modulation instability

    Microsoft Academic Search

    A. V. Mamaev; M. Saffman; A. A. Zozulya

    1996-01-01

    We present the theory and the experimental observation of break-up of two-dimensional bright spatial solitons propagating in a three-dimensional bulk photorefractive nonlinear medium due to transverse modulation instability.

  17. Thermonuclear breakup reactions of light nuclei. II - Gamma-ray line production and other applications

    NASA Technical Reports Server (NTRS)

    Guessoum, Nidhal

    1989-01-01

    The main consequence of nuclear breakup reactions in high-temperature plasmas is shown to be to reduce the production of the gamma-ray lines, due to the breakup of these species at high temperature. Results of the emissivities of all the relevant gamma-ray lines are discussed. It is shown that the magnitude of the breakup effect on the line emissivities depends strongly on temperature, but more importantly on the plasma density and on the available time for the ion processes. Other effects considered include the production of neutrons (from the breakup of helium) and its consequences (such as the production of gamma rays from n-capture reactions and dynamical effects in accretion disk plasmas).

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

    SciTech Connect

    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

    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.

  19. Is There an Interest to Use Deuteron Beams to Produce Non-Conventional Radionuclides?

    PubMed Central

    Alliot, Cyrille; Audouin, Nadia; Barbet, Jacques; Bonraisin, Anne-Cecile; Bossé, Valérie; Bourdeau, Cécile; Bourgeois, Mickael; Duchemin, Charlotte; Guertin, Arnaud; Haddad, Ferid; Huclier-Markai, Sandrine; Kerdjoudj, Rabah; Laizé, Johan; Métivier, Vincent; Michel, Nathalie; Mokili, Marcel; Pageau, Mickael; Vidal, Aurélien

    2015-01-01

    With the recent interest on the theranostic approach, there has been a renewed interest for alternative radionuclides in nuclear medicine. They can be produced using common production routes, i.e., using protons accelerated by biomedical cyclotrons or neutrons produced in research reactors. However, in some cases, it can be more valuable to use deuterons as projectiles. In the case of Cu-64, smaller quantities of the expensive target material, Ni-64, are used with deuterons as compared with protons for the same produced activity. For the Sc-44m/Sc-44g generator, deuterons afford a higher Sc-44m production yield than with protons. Finally, in the case of Re-186g, deuterons lead to a production yield five times higher than protons. These three examples show that it is of interest to consider not only protons or neutrons but also deuterons to produce alternative radionuclides.

  20. Is there an interest to use deuteron beams to produce non-conventional radionuclides?

    PubMed

    Alliot, Cyrille; Audouin, Nadia; Barbet, Jacques; Bonraisin, Anne-Cecile; Bossé, Valérie; Bourdeau, Cécile; Bourgeois, Mickael; Duchemin, Charlotte; Guertin, Arnaud; Haddad, Ferid; Huclier-Markai, Sandrine; Kerdjoudj, Rabah; Laizé, Johan; Métivier, Vincent; Michel, Nathalie; Mokili, Marcel; Pageau, Mickael; Vidal, Aurélien

    2015-01-01

    With the recent interest on the theranostic approach, there has been a renewed interest for alternative radionuclides in nuclear medicine. They can be produced using common production routes, i.e., using protons accelerated by biomedical cyclotrons or neutrons produced in research reactors. However, in some cases, it can be more valuable to use deuterons as projectiles. In the case of Cu-64, smaller quantities of the expensive target material, Ni-64, are used with deuterons as compared with protons for the same produced activity. For the Sc-44m/Sc-44g generator, deuterons afford a higher Sc-44m production yield than with protons. Finally, in the case of Re-186g, deuterons lead to a production yield five times higher than protons. These three examples show that it is of interest to consider not only protons or neutrons but also deuterons to produce alternative radionuclides. PMID:26029696

  1. Tensor electric polarizability of the deuteron in storage-ring experiments

    E-print Network

    Alexander J. Silenko

    2007-01-13

    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.

  2. Deuteron spin-lattice relaxation in ammonium hexachlorometallates.

    PubMed

    Punkkinen, M; Ylinen, E E

    2009-06-01

    Deuteron spin-lattice relaxation via the motion-dependent part of the electric quadrupole interaction is discussed in partly and fully deuterated ammonium ions of ammonium hexachlorometallates. The dominant motion at temperatures T>50K is normally 120 degrees reorientations of the ammonium ions. In some hexachlorometallates the instantaneous equilibrium directions of the nitrogen-hydrogen vectors make a certain angle Delta with the metal-nitrogen vectors and they appear in groups of six near each metal-hydrogen vector. Each N-D vector jumps between the six directions of one group and this motion (called limited jumps) dominates the deuteron relaxation at lower temperatures. In some samples one direction of each group seems to become more populated than the others when the deuteration degree exceeds a certain value and the ammonium ions become ordered. A model is derived for the relaxation rate in the absence of tunnelling splittings, which includes the effects of reorientations and limited jumps also in the ordered structure, where the limited-jump rate of a N-D vector to the preferred direction, r(p), differs from that to the nonpreferred direction, r(n). The obtained relaxation rate depends, in addition to the angle Delta, also on the ratio d=r(n)/r(p). The effect of d is discussed and estimates for it are presented on the basis of earlier experiments. The recent model for the deuteron relaxation in NH(3)D(+) ions, including the effect of proton tunnelling, is shortly reviewed. At lowest temperatures the motional rates can be dominated by corresponding incoherent tunnelling and the rate of the incoherent tunnelling contributing to limited jumps is argued to be clearly larger than that of the incoherent tunnelling contributing to approximately 120 degrees rotations. PMID:18693087

  3. Deuteron production and elliptic flow in relativistic heavy ion collisions

    E-print Network

    Oh, Yongseok; Lin, Zi-Wei; Ko, Che Ming.

    2009-01-01

    PHYSICAL REVIEW C 80, 064902 (2009) Deuteron production and elliptic flow in relativistic heavy ion collisions Yongseok Oh,1,2,* Zi-Wei Lin,3,? and Che Ming Ko1,? 1Cyclotron Institute and Physics Department, Texas A&M University, College Station...-1 ?2009 The American Physical Society YONGSEOK OH, ZI-WEI LIN, AND CHE MING KO PHYSICAL REVIEW C 80, 064902 (2009) interact with each other via hadronic rescattering. For the latter, we use the relativistic transport model (ART) [21?23] code embedded...

  4. Deuteron-nucleus collisions in a multiphase transport model

    E-print Network

    Lin, ZW; Ko, Che Ming.

    2003-01-01

    Deuteron-nucleus collisions in a multiphase transport model Zi-wei Lin Physics Department, The Ohio State University, Columbus, Ohio 43210, USA Che Ming Ko Cyclotron Institute and Physics Department, Texas A&M University, College Station, Texas... of charged particles (a) forminimum-bias events when different interactions are included and (b) for events from AMPT with Npartd =2 and with Npartd =1. ZI-WEI LIN AND CHE MING KO PHYSICAL REVIEW C 68, 054904 (2003) 054904-2 2(b) shows the pseudorapidity...

  5. Measurement of T20 in Elastic Electron-Deuteron Scattering

    E-print Network

    M. Bouwhuis; R. Alarcon; T. Botto; J. F. J. van den Brand; H. J. Bulten; S. Dolfini; R. Ent; M. Ferro-Luzzi; D. W. Higinbotham; C. W. de Jager; J. Lang; D. J. J. de Lange; N. Papadakis; I. Passchier; H. R. Poolman; E. Six; J. J. M. Steijger; N. Vodinas; H. de Vries; Z. -L. Zhou

    1998-10-05

    We report on a measurement of the tensor-analyzing power T20 in elastic electron-deuteron scattering in the range of four-momentum transfer from 1.8 to 3.2 fm-1. Electrons of 704 MeV were scattered from a polarized deuterium internal target. The tensor polarization of the deuterium nuclei was determined with an ion-extraction system, allowing an absolute measurement of T20. The data are described well by a non-relativistic calculation that includes the effects of meson-exchange currents.

  6. Measurement of the spin structure of the deuteron at COMPASS

    SciTech Connect

    Hannappel, Juergen [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz, Johann-Joachim-Becher-Weg 45, D-55099 Mainz (Germany); CERN, CH-1211 Geneva 23 (Switzerland)

    2005-10-06

    A new measurement of the longitudinal spin asymmetry A{sub 1}{sup d} and the spin dependent structure function g{sub 1}{sup d} of the deuteron is presented in the Q2 range from 1GeV2 to 100GeV2 and the x range from 0.004 to 0.7. The data were taken in 2002 and 2003 with the COMPASS experiment at CERN, scattering 160 GeV2 polarised muons off a large polarised 6LiD target. While significantly improving statistical accuracy in the low x region the data agree nicely with previous experiments.

  7. A Genesis breakup and burnup analysis in off-nominal Earth return and atmospheric entry

    NASA Technical Reports Server (NTRS)

    Salama, Ahmed; Ling, Lisa; McRonald, Angus

    2005-01-01

    The Genesis project conducted a detailed breakup/burnup analysis before the Earth return to determine if any spacecraft component could survive and reach the ground intact in case of an off-nominal entry. In addition, an independent JPL team was chartered with the responsibility of analyzing several definitive breakup scenarios to verify the official project analysis. This paper presents the analysis and results of this independent team.

  8. Capillary and acceleration wave breakup of liquid jets in axial-flow airstreams

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1981-01-01

    Empirical correlations of reciprocal mean drop diameter with airstream momentum were derived from capillary and acceleration wave breakup of liquid jets atomized by cross stream injection into axial flow airstreams. A scanning radiometer was used to obtain data over an airstream momentum range of 3.7 to 25.7 g/sq cm sec. Transition from capillary to acceleration wave breakup was obtained at a critical Weber-Reynolds number of 1,000,000.

  9. Measuring the area of tear film break-up by image analysis software

    NASA Astrophysics Data System (ADS)

    Pena-Verdeal, Hugo; García-Resúa, Carlos; Ramos, Lucía.; Mosquera, Antonio; Yebra-Pimentel, Eva; Giráldez, María. Jesús

    2013-11-01

    Tear film breakup time (BUT) test only examines the first break in the tear film, but subsequent tear film events are not monitored. We present a method of measuring the area of breakup after the appearance of the first breakup by using open source software. Furthermore, the speed of the rupture was determined. 84 subjects participated in the study. 2 ?l volume of 2% sodium fluorescein was instilled using a micropipette. The subject was seated behind a slit-lamp using a cobalt blue filter together with a Wratten 12 yellow filter. Then, the tear film was recorded by a camera attached to the slit lamp. 4 frames of each video was extracted, the first rupture (BUT_0), breakup after 1 second (BUT_1), rupture after 2 seconds (BUT_2) and breakup before the last blink (BUT_F). Open source software of measurement based on Java (NIH ImageJ) was used to measure the number of pixels in areas of breakup. These areas were divided by the area of exposed cornea to obtain the percentage of ruptures. Instantaneous breakup speed was calculated for second 1 as the difference between BUT_1 - BUT_0, whereas instant speed for second 2 was BUT_2 - BUT_1. Mean area of breakup obtained was: BUT_0 = 0.26%, BUT_1 = 0.48%, BUT_2 = 0.79% and BUT_F = 1.61%. Break speed was 0.22 area/sec for second 1 and 0.31 area/sec for second 2, showing a statistical difference between them (p = 0.007). Post BUT analysis may be easily monitoring with the aid of this software.

  10. Multifractality of drop breakup in the air-blast nozzle atomization process

    Microsoft Academic Search

    Wei-Xing Zhou; Zun-Hong Yu

    2001-01-01

    The multifractal nature of drop breakup in the air-blast nozzle atomization process has been studied. We apply the multiplier method to extract the negative and the positive parts of the f(alpha) curve with the data of drop-size distribution measured using dual particle dynamic analyzer. A random multifractal model with the multiplier triangularly distributed is proposed to characterize the breakup of

  11. Mechanical behavior of tungsten shaped charge liner materials

    SciTech Connect

    Lassila, D.H.

    1993-08-01

    Radiographs of jets produced by shaped charges with tungsten liners have documented both ductile and brittle breakup behavior. The relationships between the varying breakup behavior of tungsten shaped charge jets and metallurgical characteristics and/or mechanical behavior of the liner are not understood. In this paper the mechanical behavior of warm-forged and chemical-vapor-deposition (CVD) tungsten is discussed relative to the typical deformation history of an element of liner material which becomes part of the jet. The analyses suggest the following: (1) tungsten liner material is damaged, or possibly pulverized, during shock loading at the high-explosive detonation front; (2) pulverized material is consolidated in the convergence zone under conditions of high pressure, and (3) variations in observed breakup behavior of tungsten may be related to high temperature embrittlement. The low temperature ductile-brittle transition temperature of tungsten (DBTT) is not believed to be directly related to observed variations in break-up behavior of jets.

  12. Early breakup of Gondwana: constraints from global plate motion models

    NASA Astrophysics Data System (ADS)

    Seton, Maria; Zahirovic, Sabin; Williams, Simon; Whittaker, Joanne; Gibbons, Ana; Muller, Dietmar; Brune, Sascha; Heine, Christian

    2015-04-01

    Supercontinent break-up and amalgamation is a fundamental Earth cycle, contributing to long-term sea-level fluctuations, species diversity and extinction events, long-term greenhouse-icehouse cycles and changes in the long-wavelength density structure of the mantle. The most recent and best-constrained example involves the fragmentation of Gondwana, starting with rifting between Africa/Madagascar and Antarctica in the Early Jurassic and ending with the separation of the Lord Howe microcontinental blocks east of Australia in the Late Cretaceous. Although the first order configuration of Gondwana within modern reconstructions appears similar to that first proposed by Wegener a century ago, recent studies utilising a wealth of new geophysical and geological data provide a much more detailed picture of relative plate motions both during rifting and subsequent seafloor spreading. We present our latest global plate motion model that includes extensive, new regional analyses. These include: South Atlantic rifting, which started at 150 Ma and propagated into cratonic Africa by 145 Ma (Heine et al., 2013); rifting and early seafloor spreading between Australia, India and Antarctica, which reconciles the fit between Broken Ridge-Kergulean Plateau and the eastern Tasman region (Whittaker et al., 2013); rifting of continental material from northeastern Gondwana and its accretion onto Eurasia and SE Asia including a new model of microcontinent formation and early seafloor spreading in the eastern Indian Ocean (Gibbons et al., 2012; 2013; in review; Williams et al., 2013; Zahirovic et al., 2014); and a new model for the isolation of Zealandia east of Australia, with rifting initiating at 100 Ma until the start of seafloor spreading in the Tasman Sea at ~85 Ma (Williams et al., in prep). Using these reconstructions within the open-source GPlates software, accompanied by a set of evolving plates and plate boundaries, we can explore the factors that govern the behavior of plate motions during supercontinent break-up and subsequent dispersal. For example, a global analysis of absolute plate velocities over the past 200 million years shows that plates dominated by continental material and bounded by transforms and mid-ocean ridge segments, as is characteristic of plates involved in Gondwana break-up, have average speeds of ~2.6-2.8 cm/yr RMS. In contrast, oceanic plates surrounded by subduction have average speeds of ~8.5 cm/yr RMS. An exception, however, is the rapid motion of India (~18 cm/yr RMS) in the Paleocene preceding its collision with Eurasia, which suggests that plates with continental and cratonic keels can exhibit short-lived (~10 Myr) accelerations resulting from a combination of plume head arrival effects and other complementary plate boundary forces (i.e., slab pull and ridge push). In another example, our reconstructions illustrate that a spectrum of rifting styles from orthogonal to oblique is present during rifting, rather than dominantly orthogonal as often assumed. Although our approach has so far been limited to one supercontinent cycle, these types of models can be extended to cover the entire Phanerozoic, capturing continental rifting and plate behavior over several supercontinent cycles.

  13. The importance of momentum transfer in collision-induced breakups in low Earth orbit

    NASA Technical Reports Server (NTRS)

    Reynolds, Robert C.; Lillie, Brian J.

    1991-01-01

    Although there is adequate information on larger objects in low Earth orbit, specifically those objects larger than about 10 cm in diameter, there is little direct information on objects from this size down to 1 mm. Yet, this is the sized regime where objects acting as projectiles represent the ability to seriously damage or destroy a functioning spacecraft if they collide with it. The observed consequences of known collisional breakups in orbit indicates no significant momentum transfer in the resulting debris cloud. The position taken in this paper is that this is an observational selection effect: what is seen in these events is an explosion-like breakup of the target structure arising from shock waves introduced into the structure by the collision, but one that occurs significantly after the collision processes are completed; the collision cloud, in which there is momentum transfer, consists of small, unobserved fragments. Preliminary computations of the contribution of one known collisional breakup, Solwind at 500 km in 1985, and Cosmos 1275 in 1981, assume no momentum transfer on breakup and indicate that these two events are the dominant contributors to the current millimeter and centimeter population. A different story would emerge if momentum transfer was taken into account. The topics covered include: (1) observation of on-orbit collisional breakups; (2) a model for momentum transfer; and (3) velocity space representation of breakup clouds.

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

    NASA Astrophysics Data System (ADS)

    Sargsian, Misak; Granados, Carlos

    2009-05-01

    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.

  15. Exit doorway model for nuclear elastic breakup of weakly bound projectiles

    NASA Astrophysics Data System (ADS)

    Hussein, M. S.; Lichtenthäler, R.

    2008-05-01

    We develop the exit doorway model for elastic breakup of loosely bound projectiles. We argue that this model could, in principle, supply an alternative simplified version of the continuum discretized coupled-channels (CDCC) model. We show that the cross section for elastic breakup can be generally written as a product of the cross section for inelastic excitation times a factor containing the excitation energy and width of the exit doorway and is generally bombarding energy dependent. The excitation energy of the exit doorway is identified with the Q value of the breakup channel. The width of the exit doorway is a measure of the energy range of the continuum that is discretized. We apply the theory to derive closed expressions for the nuclear breakup cross sections in the adiabatic limit using the Austern-Blair theory. We demonstrate the approximate validity of the scaling law that dictates that the nuclear breakup cross section scales linearly with the radius of the target. We also compare our results for the nuclear breakup cross section of Be11, B8, and Be7 on several targets with recent CDCC calculation.

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

    NASA Astrophysics Data System (ADS)

    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.

    2006-11-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2007-05-01

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

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

    NASA Astrophysics Data System (ADS)

    Bocage, F.; Colin, J.; Louvel, M.; Auger, G.; Bacri, Ch. 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-Laurent, 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-Lubain, A.; Rudolf, G.; Stuttgé, L.; (Indra Collaboration)

    2000-08-01

    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.

  19. Measurement of the fluence response of the GSI neutron ball in high-energy neutron fields produced by 500 AMeV and 800 AMeV deuterons.

    PubMed

    Fehrenbacher, G; Gutermuth, F; Kozlova, E; Radon, T; Aumann, T; Beceiro, S; Le Bleis, T; Boretzky, K; Emling, H; Johansson, H; Kiselev, O; Simon, H; Typel, S

    2007-01-01

    Experiments were performed in Cave C of GSI (Gesellschaft für Schwerionenforschung) using the LAND (Large Area Neutron Detector) in combination with the deflection magnet ALADIN (A LArge DIpol magNet) in front of the LAND where charged particles and neutrons can be separated. This arrangement is used to create high-energetic neutron fields by irradiation of a thick lead target (5 cm) with deuteron beams with the energies of 500 or 800 MeV per nucleon. In break-up reactions the neutron is separated from the proton which is deflected in the magnetic field of the ALADIN. The produced neutron radiation, which has a pronounced peak at the nucleon energy, is used to measure the fluence response of the GSI neutron ball. A thermoluminescence (TL) based spherical neutron dosemeter was developed for the area monitoring for the quantity H(10) at high-energy accelerators. In the same experiment, the spectral neutron fluence Phi(E) is measured with the LAND in the energy range from 100 MeV to 1 GeV. The measured fluence responses are compared with results of FLUKA calculations and the corresponding fluence-to-dose conversion coefficients. The measured dosemeter responses are too high in comparison to the calculated ones (up to approximately 50%), the dosemeter reading gives dose values which are too high by a factor of 1.1-2.2 related to the corresponding fluence-to-dose conversion factors. PMID:17519242

  20. MuSun: muon capture on the deuteron

    NASA Astrophysics Data System (ADS)

    Luo, Xiao

    2015-05-01

    The goal of the MuSun experiment at PSI is to measure the rate of muon capture on the deuteron with a precision of 1.5%. This rate will be used to fix the low-energy constant that describes the two-nucleon weak axial current in Chiral perturbation theory. It will therefore calibrate evaluations of solar proton-proton fusion and neutrino-deuteron scattering(SNO experiment). MuSun forms part of the systematic program to achieve a new level of precision in confronting the theories of weak interactions, QCD and few body physics. MuSun inherits some of the well developed techniques and apparatus from a successful measurement of the rate for muon capture on the proton, the MuCap experiment, also performed at PSI. As in MuCap, MuSun uses a TPC as an active target. To optimize the molecular kinetics, its ultra-pure deuterium gas is kept at 31K. The status of the hardware and details of the data analysis for a high statistics run taken in 2013 will be presented.

  1. Generation of Radioisotopes with Accelerator Neutrons by Deuterons

    NASA Astrophysics Data System (ADS)

    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

    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.

  2. Panjal Paleomagnetism: Implications for Early Permian Gondwana break-up

    NASA Astrophysics Data System (ADS)

    Stojanovic, D.; Aitchison, J.; Ali, J. R.; Ahmad, T.; Ahmad Dar, R.; Agarwal, A.; Roeder, T.

    2013-12-01

    The mid-Early Permian represents an important phase in Pangaea's development marking the time when the >13,000 km-long string of terranes that are collectively known as 'Cimmeria' separated from Gondwana's Tethyan margin (northern Africa-NE Arabia-northern India-NW and northern Australia). The ~289 Ma Panjal Traps of NW India (Kashmir) are one of a number of mafic suites (Abor, Sikkim etc.) that were erupted onto the Indian block possibly during the separation of the Lhasa/SE Qiangtang block. Herein, we report data from the first modern paleomagnetic study of the unit. Results from four quarry sections (15 individual cooling units) from a locality close to Srinagar together form a tectonically coherent sequence spanning 2-3 km of stratigraphy. The derived direction and paleopole yield key new information concerning (1) the Early Permian location of India, and by inference that of central Gondwana, and (2) inform debates related to Cimmeria's breakup from eastern Gondwana. Moreover, they provide a new independent control for assessing NW Greater India's extent prior to its collision with Asia and the amount of vertical-axis rotation this sector of the Himalayan range experienced in the mid to late Cenozoic.

  3. Drag reduction - Jet breakup correlation with kerosene-based additives

    NASA Technical Reports Server (NTRS)

    Hoyt, J. W.; Altman, R. L.; Taylor, J. J.

    1980-01-01

    The drag-reduction effectiveness of a number of high-polymer additives dissolved in aircraft fuel has been measured in a turbulent-flow rheometer. These solutions were further subjected to high elongational stress and breakup forces in a jet discharging in air. The jet was photographed using a high-resolution camera with special lighting. The object of the work was to study the possible spray-suppression ability of high-polymer additives to aircraft fuel and to correlate this with the drag-reducing properties of the additives. It was found, in fact, that the rheometer results indicate the most effective spray-suppressing additives. Using as a measure the minimum polymer concentration to give a maximum friction-reducing effect, the order of effectiveness of eight different polymer additives as spray-suppressing agents was predicted. These results may find application in the development of antimisting additives for aircraft fuel which may increase fire safety in case of crash or accident.

  4. Did a discrete asteroid breakup event affect Gaspra's cratering record?

    NASA Astrophysics Data System (ADS)

    Menichella, M.

    1997-02-01

    Recent analysis of the cratering record on the asteroid (951) Gaspra has indicated an index (exponent of the power law describing the cumulative distribution of craters as a function of diameter) ? = -3.3±0.3, definitely steeper than the theoretically derived value of -2.5 expected for a projectile population in collisional equilibrium. A single, very energetic breakup event which locally injected debris into the main-belt population with a size distribution unrelated to the equilibrium value has been proposed as a simple explanation for this finding. I have tested this hypothesis using the numerical algorithm described in Campo Bagatin et al. ( Planet. Space Sci.42, 1079-1092, 1099-1107, 1994) to model the outcome of impacts between asteroids of very large sizes and to assess their transient consequences on the main-belt size distribution as a function of time. The results show that the previous hypothesis is very unlikely in the case of Gaspra because it requires two ad hoc assumptions: (1) that the assumed impact should have involved two relatively large asteroids, hence its a priori probability of occurring during the whole history of the Solar System would have been low; (2) and that this event should have occurred as recently as ? 10 Myr ago.

  5. Cheating, breakup, and divorce: is Facebook use to blame?

    PubMed

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

    2013-10-01

    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

  6. Beam break-up estimates for the ERL at BNL

    SciTech Connect

    Ben-Zvi, I.; Calaga, R.; Hahn, H.; Hammons, L.; Johnson, E.; Kayran, D.; Litvinenko, V.; Kewisch, J.; Xu, W.

    2010-05-23

    A prototype Ampere-class superconducting energy recovery linac (ERL) is under advanced construction at BNL. The ERL facility is comprised of a five-cell SC Linac plus a half-cell SC photo-injector RF electron gun, both operating at 703.75 MHz. The facility is designed for either a high-current mode of operation up to 0.5 A at 703.75 MHz or a high-bunch-charge mode of 5 nC at 10 MHz bunch frequency. The R&D facility serves a test bed for an envisioned electron-hadron collider, eRHIC. The high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory, and requires the determination of HOM tolerances for a cavity upgrade. The niobium cavity has been tested at superconducting temperatures and has provided measured quality factors (Q) for a large number of modes. These numbers were used for the estimate of the beam breakup instability (BBU). The facility will be assembled with a highly flexible lattice covering a vast operational parameter space for verification of the estimates and to serve as a test bed for the concepts directed at future projects.

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

    SciTech Connect

    Lechman, Jeremy B.

    2010-10-01

    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.

  8. Style of rifting and the stages of Pangea breakup

    NASA Astrophysics Data System (ADS)

    Frizon de Lamotte, Dominique; Fourdan, Brendan; Leleu, Sophie; Leparmentier, François; Clarens, Philippe

    2015-05-01

    Pangea results from the progressive amalgamation of continental blocks achieved at 320 Ma. Assuming that the ancient concept of "active" versus "passive" rifting remains pertinent as end-members of more complex processes, we show that the progressive Pangea breakup occurred through a succession of rifting episodes characterized by different tectonic evolutions. A first episode of passive continental rifting during the Upper Carboniferous and Permian led to the formation of the Neo-Tethys Ocean. Then at the beginning of Triassic times, two short episodes of active rifting associated to the Siberian and Emeishan large igneous provinces (LIPs) failed. The true disintegration of Pangea resulted from (1) a Triassic passive rifting leading to the emplacement of the central Atlantic magmatic province (200 Ma) LIP and the subsequent opening of the central Atlantic Ocean during the lowermost Jurassic and from (2) a Lower Jurassic active rifting triggered by the Karoo-Ferrar LIP (183 Ma), which led to the opening of the West Indian Ocean. The same sequence of passive then active rifting is observed during the Lower Cretaceous with, in between, the Parana-Etendeka LIP at 135 Ma. We show that the relationships between the style of rifts and their breakdown or with the type of resulting margins (as magma poor or magma dominated) are not straightforward. Finally, we discuss the respective role of mantle global warming promoted by continental agglomeration and mantle plumes in the weakening of the continental lithosphere and their roles as rifting triggers.

  9. Breakup Reactions and Exclusive Measurements in the {sup 6,7}Li+{sup 144}Sm Systems

    SciTech Connect

    Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A. E. [Departamento de Fisica-TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, B1650KNA 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, B1650KNA 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, B1650KNA San Martin (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Universidad Nacional de General San Martin, Ayacucho 2197, B1650BWA San Martin (Argentina); Marta, H. D. [Instituto de Fisica, Facultad de Ingenieria, CC 30 Montevideo (Uruguay)

    2009-06-03

    The breakup of the projectile-like nuclei in reactions induced by 30 MeV {sup 6}Li and {sup 7}Li beams on a {sup 144}Sm target have been measured through the coincident detection of the in-plane emitted light particles. The primary ion that undergoes breakup has been identified and the physically meaningful variables that characterize the reaction have been obtained on a purely experimental basis. Distributions have been obtained for both the binary emission angle and for the breakup emission angle in the reference frame of the breakup products.

  10. Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies

    E-print Network

    R. Asaturyan; R. Ent; H. Mkrtchyan; T. Navasardyan; V. Tadevosyan; G. S. Adams; A. Ahmidouch; T. Angelescu; J. Arrington; A. Asaturyan; O. K. Baker; N. Benmouna; C. Bertoncini; H. P. Blok; W. U. Boeglin; P. E. Bosted; H. Breuer; M. E. Christy; S. H. Connell; Y. Cui; M. M. Dalton; S. Danagoulian; D. Day; J. A. Dunne; D. Dutta; N. El Khayari; H. C. Fenker; V. V. Frolov; L. Gan; D. Gaskell; K. Hafidi; W. Hinton; R. J. Holt; T. Horn; G. M. Huber; E. Hungerford; X. Jiang; M. Jones; K. Joo; N. Kalantarians; J. J. Kelly; C. E. Keppel; V. Kubarovsky; Y. Li; Y. Liang; D. Mack; S. P. Malace; P. Markowitz; E. McGrath; P. McKee; D. G. Meekins; A. Mkrtchyan; B. Moziak; G. Niculescu; I. Niculescu; A. K. Opper; T. Ostapenko; P. E. Reimer; J. Reinhold; J. Roche; S. E. Rock; E. Schulte; E. Segbefia; C. Smith; G. R. Smith; P. Stoler; L. Tang; M. Ungaro; A. Uzzle; S. Vidakovic; A. Villano; W. F. Vulcan; M. Wang; G. Warren; F. R. Wesselmann; B. Wojtsekhowski; S. A. Wood; C. Xu; L. Yuan; X. Zheng

    2011-12-15

    A large set of cross sections for semi-inclusive electroproduction of charged pions ($\\pi^\\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4 GeV$^2$ and range in four-momentum transfer squared $2 pion production mechanisms. The x, z and $P_t^2$ dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for $\\pi^+$ and $\\pi^-$) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of $d$ quarks are found to be slightly smaller than for $u$ quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

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

    PubMed

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

    2008-12-01

    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

  12. Polarization observables in lepton-deuteron elastic scattering including the lepton mass

    NASA Astrophysics Data System (ADS)

    Gakh, G. I.; Gakh, A. G.; Tomasi-Gustafsson, E.

    2014-12-01

    Expressions for the unpolarized differential cross section and for various polarization observables in the lepton-deuteron elastic scattering, ? +D ?? +D ,? =e ,? ,? , have been obtained in the one-photon-exchange approximation, taking into account the lepton mass. Polarization effects have been investigated for the case of a polarized lepton beam and polarized deuteron target which can have vector or tensor polarization. Numerical estimations of the lepton mass effects have been done for the unpolarized differential cross section and for some polarization observables and applied to the case of low-energy muon deuteron elastic scattering.

  13. Determination of the Azimuthal Asymmetry of Deuteron Photodisintegration in the Energy Region E{sub {gamma}} = 1.1 - 2.3 GeV

    SciTech Connect

    Nicholas Zachariou

    2012-05-20

    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 (P{sub y}), along with the polarization transfers (C{sub x'} and C{sub z'} ), have been shown to be insensitive to differences between theoretical models. On the other hand, the beam-spin asymmetry {Sigma} 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 ~80% were produced using the coherent bremsstrahlung facility in Hall B. The work done by the author to calibrate a specific detector system, select deuteron photodisintegration events, study the degree of photon polarization, and finally determine the azimuthal asymmetry and any systematic uncertainties associate with it, is comprehensively explained. 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.

  14. Estimation of the nuclear distortion in the Coulomb breakup of 6Li into ? + d in the field of 208Pb ion

    NASA Astrophysics Data System (ADS)

    Irgaziev, B. F.

    2014-04-01

    In this article the results of the evaluation of the contribution of nuclear disintegration, based on the basis of diffraction theory in the 208Pb(6Li, ?d)208Pb Coulomb breakup at an energy of 156 MeV is presented. Comparison of the results of the calculation with the experimental data of Kiener et al. [Phys. Rev. C 44, 2195 (1991)] gives evidence for the dominance of the Coulomb dissociation mechanism and contribution of nuclear distortion, but essentially smaller than the value reported byHammache et al. [Phys. Rev. C 82, 065803 (2010)] and Sümmerer [Prog. Part. Nucl. Phys. 66, 298 (2011)].

  15. Coexistence of different droplet generating instabilities: new breakup regimes of a liquid filament.

    PubMed

    Hein, Michael; Fleury, Jean-Baptiste; Seemann, Ralf

    2015-07-14

    The coexistence of multiple droplet breakup instabilities in a Step-emulsification geometry is studied. A liquid filament, which is confined in one dimension by channel walls and surrounded by a co-flowing immiscible continuous phase, decays into droplets when subject to a sudden release of confinement. Depending on the filament aspect ratio and liquid flow rates, an unexpectedly rich variety of droplet breakup regimes is found. All of these breakup regimes are composed of two basic instabilities, i.e. a step- and a jet-instability, that coexist in various combinations on the same filament. Surprisingly, even an asymmetric breakup regime is found, producing droplet families of significantly different diameters, while the filament is subject to a fully symmetric flow field. We suggest key physical principles explaining the spontaneous symmetry breaking and the transitions between individual droplet breakup regimes. The particular ability to produce distinct droplet families from a single filament is demonstrated to allow for simultaneous concentration and encapsulation of particles into one droplet family while excess bulk liquid is released into another family of droplets. PMID:26053325

  16. Exclusive Measurements of Breakup Reactions in the {sup 7}Li+{sup 144}Sm System

    SciTech Connect

    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

    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.

  17. Practical method to identify orbital anomaly as spacecraft breakup in the geostationary region

    NASA Astrophysics Data System (ADS)

    Hanada, Toshiya; Uetsuhara, Masahiko; Nakaniwa, Yoshitaka

    2012-07-01

    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.

  18. Far-field breakup of spiral waves in the plankton ecological systems

    E-print Network

    Liu, Quan-Xing

    2007-01-01

    For oscillatory conditions, breakup of the spiral waves far away from the spiral core (as so-called "far-field breakup") was reported in a simple activator-inhibitor model by Markus B\\"{a}r, Michal Or-Guil and Lutz Brusch [Phys. Rev. Lett. \\textbf{82}, 1160 (1999) and New J. Phys. \\textbf{6}, 5 (2004)], which is in the chemical reaction-diffusion system. In present letter, the scenario in the plankton ecological system is reported. The spatial plankton model is studied numerically by computer and we find that the far-field breakup also exists in the oceanic ecological systems over a range of diffusion coefficients of phytoplankton and zooplankton. The far-field breakup leading to the spatial chaos patterns can be verified in field observation and is useful to understand the population dynamics of oceanic ecological systems. It also indicates that the far-field breakup may be a common phenomenon in the world. Finally, we give some illumination from the ecological meaning.

  19. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay

    USGS Publications Warehouse

    Regehr, E.V.; Lunn, N.J.; Amstrup, Steven C.; Stirling, I.

    2007-01-01

    Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack-Jolly-Seber capture-recapture models to estimate population size and survival for polar bears (Ursus maritimus), one of the most ice-dependent of Arctic marine mammals. We analyzed data for polar bears captured from 1984 to 2004 along the western coast of Hudson Bay and in the community of Churchill, Manitoba, Canada. The Western Hudson Bay polar bear population declined from 1,194 (95% CI = 1,020-1,368) in 1987 to 935 (95% CI = 794-1,076) in 2004. Total apparent survival of prime-adult polar bears (5-19 yr) was stable for females (0.93; 95% CI = 0.91-0.94) and males (0.90; 95% CI = 0.88-0.91). Survival of juvenile, subadult, and senescent-adult polar bears was correlated with spring sea ice breakup date, which was variable among years and occurred approximately 3 weeks earlier in 2004 than in 1984. We propose that this correlation provides evidence for a causal association between earlier sea ice breakup (due to climatic warming) and decreased polar bear survival. It may also explain why Churchill, like other communities along the western coast of Hudson Bay, has experienced an increase in human-polar bear interactions in recent years. Earlier sea ice breakup may have resulted in a larger number of nutritionally stressed polar bears, which are encroaching on human habitations in search of supplemental food. Because western Hudson Bay is near the southern limit of the species' range, our findings may foreshadow the demographic responses and management challenges that more northerly polar bear populations will experience if climatic warming in the Arctic continues as projected.

  20. Polarized deuterons and protons at NICA@JINR

    NASA Astrophysics Data System (ADS)

    Kovalenko, A. D.; Filatov, Yu. N.; Kondratenko, A. M.; Kondratenko, M. A.; Mikhaylov, V. A.

    2014-01-01

    The novel scheme of proton and deuteron polarization control in the NICA collider at Dubna is proposed. By means of two Siberian Shakes with solenoid magnetic field the beam spin tune is shifted to the "zero" spin resonance vicinity, whereas manipulation of the polarization is realized by "weak" field solenoids. The scheme makes it possible to obtain any desired direction of the polarization in the both MPD and SPD detectors for any sort of the particles. The possibility of the beam polarization control in the orbit plane at any azimuth of the collider magnetic arcs exists also. The last gives necessary flexibility of optimal matching the beam polarization at injection into collider and at the polarimetery monitor points.

  1. Structure and dynamics of chiral ferrielectric phases by deuteron NMR.

    PubMed

    Xu, J; Veracini, C A; Dong, Ronald Y

    2006-01-01

    The results of studying angular dependent spectral parameters in a magnetic field are reported in the chiral smectic C phases of a smectogen 1-methylheptyl -(4-n-decyloxybenzoyloxy)-biphenyl-4-carboxylate. Our data provide direct evidence of a phase transition between two ferrielectric phases in this compound, viz. three-layer (SmC*(FiI)) and four-layer (SmC*(FiII)) superlattices. Simulation of spectral patterns of the methyl (C10) deuterons obtained after an aligned sample is rotated by 90 degrees in the magnetic field rules out the "clock model" for the three-layer and four-layer structures in these ferriphases. Instead, our data obtained under a magnetic field (9.4 T) seem to favor an "asymmetric clock model" for the interlayer packing. Interlayer jump rate is also obtained from the simulation of angular dependent spectra in these ferrielectric phases, and compared with those in the antiferroelectric SmC*(A) phase. PMID:16486167

  2. Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment

    DOE PAGESBeta

    Gross, Franz

    2015-01-01

    The deuteron quadrupole moment is calculated using two CST model wave functions obtained from the 2007 high precision fits to np scattering data. Included in the calculation are a new class of isoscalar np interaction currents automatically generated by the nuclear force model used in these fits. The prediction for model WJC-1, with larger relativistic P-state components, is 2.5% smaller that the experiential result, in common with the inability of models prior to 2014 to predict this important quantity. However, model WJC-2, with very small P-state components, gives agreement to better than 1%, similar to the results obtained recently frommore »chiral effect field theory predictions to order next-to-next-to-next-to-leading order.« less

  3. Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment

    DOE PAGESBeta

    Gross, Franz

    2015-01-01

    The deuteron quadrupole moment is calculated using two CST model wave functions obtained from the 2007 high precision fits to np scattering data. Included in the calculation are a new class of isoscalar np interaction currents automatically generated by the nuclear force model used in these fits. The prediction for model WJC-1, with larger relativistic P-state components, is 2.5% smaller that the experiential result, in common with the inability of models prior to 2014 to predict this important quantity. However, model WJC-2, with very small P-state components, gives agreement to better than 1%, similar to the results obtained recently from chiral effect field theory predictions to order next-to-next-to-next-to-leading order.

  4. Deuteron Matrix Elements in Chiral Effective Theory at Leading Order

    E-print Network

    L. Platter; D. R. Phillips

    2006-05-12

    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^n, 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 greater than or equal to 3 general arguments about the short-distance behavior of the leading-order deuteron wave function show that the matrix element will diverge.

  5. Charge symmetry violation effects in pion scattering off the deuteron

    SciTech Connect

    Baru, V. V.; Kudryavtsev, A. E.; Tarasov, V. E.; Briscoe, W. J.; Dhuga, K. S.; Strakovsky, I. I.

    2000-10-01

    We discuss the theoretical and experimental situations for charge symmetry violation (CSV) effects in the elastic scattering of {pi}{sup +} and {pi}{sup -} on deuterium (D) and {sup 3}He/{sup 3}H. Accurate comparison of data for both types of targets provides evidence for the presence of CSV effects. While there are indications of a CSV effect in deuterium, it is much more pronounced in the case of {sup 3}He/{sup 3}H. We provide a description of the CSV effect on the deuteron in terms of single- and double-scattering amplitudes. The {Delta}-mass splitting is taken into account. Theoretical predictions are compared with existing experimental data for {pi}-d scattering; a future article will speak to the {pi}-three nucleon case.

  6. Size-shrinking of deuterons in very dilute superfluid nuclear matter

    E-print Network

    U. Lombardo; P. Schuck

    2000-11-24

    It is shown within the strong-coupling BCS approach that, starting from the zero-density limit of superfluid nuclear matter, with increasing density deuterons first shrink before they start expanding.

  7. Nuclear physics in soft-wall AdS/QCD: Deuteron electromagnetic form factors

    NASA Astrophysics Data System (ADS)

    Gutsche, Thomas; Lyubovitskij, Valery E.; Schmidt, Ivan; Vega, Alfredo

    2015-06-01

    We present a high-quality description of the deuteron electromagnetic form factors in a soft-wall anti-de Sitter/quantum chromodynamics approach. We first propose an effective action describing the dynamics of the deuteron in the presence of an external vector field. Based on this action the deuteron electromagnetic form factors are calculated, displaying the correct 1 /Q10 power scaling for large Q2 values. This finding is consistent with quark counting rules and the earlier observation that this result holds in confining gauge/gravity duals. The Q2 dependence of the deuteron form factors is defined by a single and universal scale parameter ? , which is fixed from data.

  8. E1 density transitions from the low-energy deuteron photodisintegration

    Microsoft Academic Search

    E. Lipparini; G. Orlandini

    1982-01-01

    The dynamical dipole polarizability and transition density for the deuteron are studied in the Bethe-Peierls model for deuteron photodisintegration. In two limiting values of the frequency of the oscillating field, the transition density is shown to have simple forms corresponding to pure surface and a mixing of surface and volume deformations respectively. Predictions for the low-q behaviour of the E1

  9. Deuteron emission from pion absorption at Tpi = 65 MeV

    Microsoft Academic Search

    H. Yokota; K. Nakayama; K. Ichimaru; Y. Takahata; F. Suekane; R. Chiba; K. Nakai; I. Arai; H. En'yo; S. Sasaki; T. Nagae; M. Sekimoto

    1986-01-01

    The angular distributions of high-energy deuterons and proton-deuteron coincident events were measured at Tpi = 65 MeV for C, Al and Cu. The angular distribution of the inclusive (pi+, d) cross section was similar to that of the inclusive (pi+, p?) reaction, but the ratios of the inclusive (pi+, pd?) cross section to the inclusive (pi+, pp) cross section had

  10. Measurements of the deuteron elastic structure function A(Q²) at the Jefferson Laboratory

    Microsoft Academic Search

    Michael Kuss

    1998-01-01

    Results from experiment E91-026 in Hall A at the Jefferson Laboratory are reported. The aim of this experiment was to extract the deuteron structure function A(Q²) from the coincidence elastic electron-deuteron cross-section measurements. A squared four-momentum transfer (Q²) range of 0.7 to 6.0 (Gev\\/c)² was covered. Data from this experiment improve the quality of existing data at the low end

  11. Measurements of the Deuteron Elastic Structure Function A(Q²) for 0.7

    Microsoft Academic Search

    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. dHose; 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; 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

    1999-01-01

    The deuteron elastic structure function A(Q²) has been extracted in the range 0.7 < or = Q² < or = 6.0 (GeV\\/c)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

  12. Practical method to identify orbital anomaly as spacecraft breakup in the geostationary region

    NASA Astrophysics Data System (ADS)

    Uetsuhara, Masahiko; Hanada, Toshiya

    2013-09-01

    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.

  13. Droplet Deformation Prediction With the Droplet Deformation and Breakup Model (DDB)

    NASA Technical Reports Server (NTRS)

    Vargas, Mario

    2012-01-01

    The Droplet Deformation and Breakup Model was used to predict deformation of droplets approaching the leading edge stagnation line of an airfoil. The quasi-steady model was solved for each position along the droplet path. A program was developed to solve the non-linear, second order, ordinary differential equation that governs the model. A fourth order Runge-Kutta method was used to solve the equation. Experimental slip velocities from droplet breakup studies were used as input to the model which required slip velocity along the particle path. The center of mass displacement predictions were compared to the experimental measurements from the droplet breakup studies for droplets with radii in the range of 200 to 700 mm approaching the airfoil at 50 and 90 m/sec. The model predictions were good for the displacement of the center of mass for small and medium sized droplets. For larger droplets the model predictions did not agree with the experimental results.

  14. Bag breakup of low viscosity drops in the presence of a continuous air jet

    SciTech Connect

    Kulkarni, V., E-mail: vkulkarn@purdue.edu; Sojka, P. E. [Maurice J. Zucrow Laboratories, Purdue University, West Lafayette, Indiana 47906 (United States)

    2014-07-15

    This work examines the breakup of a single drop of various low viscosity fluids as it deforms in the presence of continuous horizontal air jet. Such a fragmentation typically occurs after the bulk liquid has disintegrated upon exiting the atomizer and is in the form of an ensemble of drops which undergo further breakup. The drop deformation and its eventual disintegration is important in evaluating the efficacy of a particular industrial process, be it combustion in automobile engines or pesticide spraying in agricultural applications. The interplay between competing influences of surface tension and aerodynamic disruptive forces is represented by the Weber number, We, and Ohnesorge number, Oh, and used to describe the breakup morphology. The breakup pattern considered in our study corresponds to that of a bag attached to a toroidal ring which occurs from ?12 < We < ?16. We aim to address several issues connected with this breakup process and their dependence on We and Oh which have been hitherto unexplored. The We boundary at which breakup begins is theoretically determined and the expression obtained, We=12(1+2/3Oh{sup 2}), is found to match well with experimental data ([L.-P. Hsiang and G. M. Faeth, Int. J. Multiphase Flow 21(4), 545–560 (1995)] and [R. S. Brodkey, “Formation of drops and bubbles,” in The Phenomena of Fluid Motions (Addison-Wesley, Reading, 1967)]). An exponential growth in the radial extent of the deformed drop and the streamline dimension of the bag is predicted by a theoretical model and confirmed by experimental findings. These quantities are observed to strongly depend on We. However, their dependence on Oh is weak.

  15. The Dispersal of East Gondwana from Continental Breakup to the Start of the Cretaceous Quiet Zone

    NASA Astrophysics Data System (ADS)

    Davis, J. K.; Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2014-12-01

    Existing plate models for the breakup of Africa and East Gondwana (Australia, East Antarctica, India, Madagascar, the Seychelles, and Sri Lanka) are problematic and require revision. Specific problems include the utilization of dubious Gondwana configurations, improbable plate motion, and/or a failure to satisfy the holistic marine magnetic anomaly data. I present here a new model for the breakup of East Gondwana. This new model begins from a constrained, pre-breakup, Gondwana configuration. Out of this initial "tight-fit" configuration, East Gondwana rifts from West Gondwana (Africa & South America) as a cohesive unit. During this breakup and subsequent seafloor spreading, East Gondwana is devoid of any internal compression or anomalous plate motion. The overall motion of East Gondwana is constrained by seafloor spreading in the coeval Somali Basin and Mozambique/Riiser Larsen Basins. Seafloor spreading in these basins is modeled using existing marine magnetic anomaly interpretations and satellite-derived gravity data. Our model is uniquely able to satisfy the magnetic anomaly observations in both of the aforementioned basins without invoking improbable plate motion or configurations. Additionally, our plate model provides valuable insight into the breakup of India and East Antarctica. In this model, we fix India to Madagascar from breakup to 90 Ma, thus eventual separation between India and East Antarctica is an output, not an input of our model. We suggest that this separation occurred diachronously from ~140 Ma in the east to ~120 Ma in the west. This modeled motion between India and East Antarctica agrees well with geophysical observations from the margin of East Antarctica and our preliminary analysis of margin character and variability.

  16. Under-ice movement of cohesive sediments before river-ice breakup

    NASA Astrophysics Data System (ADS)

    Milburn, D.; Prowse, T. D.

    2002-03-01

    A significant body of research exists on river hydraulics and sediment transport during open-water conditions, and to a lesser extent during the period of ice-cover. Most of the ice-related studies, however, are based on controlled laboratory experiments or field studies conducted under stable ice-cover conditions. They have largely ignored the most dynamic periods, such as breakup, when hydraulic conditions are most rapidly changing and energy levels are maximized. Moreover, the entire pre-breakup to ice-clearance period is virtually devoid of even standard hydrometric measurements of suspended sediment, largely because of safety and logistic problems. Some recent work has pointed to the formation of a sediment plume comprising fine-grained sediments that develops before the main breakup fracturing of the ice cover. This plume has been noted as being particularly ecologically significant because it can contain the winter-long deposition of contaminants that preferentially attach to fine-grained material. Unfortunately, however, because measurements of the critical parameters affecting sediment transport during these periods are rarely taken, much uncertainty remains about the hydraulic forces that resuspend and transport sediments under an ice cover, and particularly for cohesive fine-grained sediments. This paper describes a field experiment designed to broaden our understanding of sediment transport during this critical pre-breakup period. Detailed measurements of river stage, ice elevations, flow velocity profiles and suspended sediment were taken over a 17-day period just before the 1998 river-ice breakup at Hay River, Northwest Territories, Canada. Results indicated that just before breakup, the shear stress, which governs the beginning of sediment motion, increases dramatically and drives the development of the under-ice sediment plume of very fine-grained, cohesive sediments. The shear stress in this case became critical at a mean under-ice velocity of 0·4 m/s.

  17. Influence of insoluble surfactant on the deformation and breakup of a bubble or thread in a viscous fluid

    Microsoft Academic Search

    M. Hameed; M. Siegel; Y.-N. Young; J. Li; M. R. Booty; D. T. Papageorgiou

    2008-01-01

    The influence of surfactant on the breakup of a prestretched bubble in a quiescent viscous surrounding is studied by a combination of direct numerical simulation and the solution of a long-wave asymptotic model. The direct numerical simulations describe the evolution toward breakup of an inviscid bubble, while the effects of small but non-zero interior viscosity are readily included in the

  18. Analyses of Kolmogorov's model of breakup and its application into Lagrangian computation of liquid sprays under air-blast atomization

    Microsoft Academic Search

    M. A. Gorokhovski; V. L. Saveliev

    2003-01-01

    This paper considers the breakup of liquid drops at the large Weber number within the framework of Kolmogorov's scenario of breakup. The population balances equation for droplet radius distribution is written to be an invariant under the group of scaling transformations. It is shown that due to this symmetry, the long-time limit solution of this equation is a power function.

  19. Effects of thermal quenching on the breakup of pyroclasts

    NASA Astrophysics Data System (ADS)

    Patel, A.; Manga, M.; Carey, R. J.; Degruyter, W.; Dufek, J.

    2012-12-01

    It is often assumed that magma fragments when it contacts water. Obsidian chips and glass spheres crack when quenched. Vesicular pyroclasts are made of similar glass, so thermal quenching may cause them to break more easily. We performed a set of experiments on air fall pumice from Medicine Lake, California. Density and texture of similar samples are described in Manga et al., Bull Volc 2010. We made "quenched" samples by heating natural pyroclasts to 600 °C, quenching them in water at 21 °C, drying them at 105 °C, and then cooling them to room temperature. We compare these samples with untreated air fall pumice from the same deposit, hereafter referred to as "regular" pumice. We tested whether quenched pumice would 1) shatter more easily in collisions and 2) abrade faster. Our collision experiment methods are described in Dufek et al., Nature Geoscience 2012. Our abrasion experiment methods are described in Manga et al., Bull Volc 2010. We also tested whether individual clasts lose mass upon quenching and whether they increase in effective wet density. Effective wet density is defined as underwater density of a clast when water occupies part of the pore space. Effective wet density, measured as a function of time after immersion, indicates the volume fraction of the pore space that becomes occupied by water. We compare effective wet density of individual clasts pre-quenching with effective wet density after having been quenched, thoroughly dried and then cooled to room temperature. An increase in effective wet density would suggest that bubble walls had been damaged during quenching, allowing water to occupy the pore space faster. We also compare pre-quenching and post-quenching textures using X-Ray Tomography (XRT) and SEM images. Results from collision experiments show no obvious difference between quenched pumice and regular pumice. Quenched pumice abraded more quickly than regular pumice. We find that 1 to 2 % of mass was lost during quenching. Effective wet density increased 0 to 2.5 %, as measured after 5 minutes immersion in water. Overall we see modest differences between quenched pumice and regular pumice in breakup, abrasion, mass, and effective wet density. Experimental results suggest that quenching may damage small parts of a clast but tends not to cause cracks that propagate easily through the clast. XRT and SEM imaging confirms that quenching only damages small external parts. This is in stark contrast to non-vesicular glass that develops large cracks on quenching.

  20. The Porcupine Basin: from rifting to continental breakup

    NASA Astrophysics Data System (ADS)

    Reston, Timothy; Gaw, Viola; Klaeschen, Dirk; McDermott, Ken

    2015-04-01

    Southwest of Ireland, the Porcupine Basin is characterized by axial stretching factors that increase southward to values greater than six and typical of rifted margins. As such, the basin can be regarded as a natural laboratory to investigate the evolution and symmetry of rifting leading towards continental separation and breakup, and in particular the processes of mantle serpentinisation, and the onset of detachment faulting. We have processed through to prestack depth migration a series of E-W profiles crossing the basin at different axial stretching factors and linked by a N-S profile running close to the rift axis. Our results constrain the structure of the basin and have implications for the evolution of rifted margins. In the north at a latitude of 52.25N, no clear detachment is imaged, although faults do appear to cut down into the mantle, so that serpentinisation may have started. Further south (51.75N), a bright re?ection (here named P) cuts down to the west from the base of the sedimentary section, is overlain by small fault blocks and appears to represent a detachment fault. P may in part follow the top of partially serpentinized mantle: this interpretation is consistent with gravity modelling, with numerical models of crustal embrittlement and mantle serpentinization during extension and with wide-angle data (see posters of Prada and of Watremez). Furthermore, P closely resembles the S re?ection west of Iberia, where such serpentinites are well documented. P develops where the crust was thinned to less than 3 km during rifting, again similar to S. Although overall the basin remains symmetrical, the consistent westward structural dip of the detachment implies that, at high stretching factors, extension became asymmetric. Analysis of the depth sections suggests that the detachment may have been active as a rolling hinge rooting at low-angle beneath the Porcupine Bank, consistent with the presence of a footwall of serpentinites. This requires very weak fault rocks, such as serpentinites. Reconstructions suggest that the detachment developed after the onset of serpentinisation and thus represents late stage of faulting within a complex polyphase rift history. Farther south still, a N-S running profile shows that P cuts up to form the top of the basement, and locally forms the top of what we interpret as exhumed mantle, since buried by postrift sediments. Thus detachment here appear to have been both responsible for the late-stage extension of the crust and the unroofing of the mantle. The same processes are likely to have occurred at magma poor rifted margins.

  1. Physics-Based Modeling of Meteor Entry and Breakup

    NASA Technical Reports Server (NTRS)

    Prabhu, Dinesh K.; Agrawal, Parul; Allen, Gary A.; Brandis, Aaron M.; Chen, Yih-Kanq; Jaffe, Richard L.; Saunders, David A.; Stern, Eric C.; Tauber, Michael E.; Venkatapathy, Ethiraj

    2015-01-01

    A new research effort at NASA Ames Research Center has been initiated in Planetary Defense, which integrates the disciplines of planetary science, atmospheric entry physics, and physics-based risk assessment. This paper describes work within the new program and is focused on meteor entry and breakup. Over the last six decades significant effort was expended in the US and in Europe to understand meteor entry including ablation, fragmentation and airburst (if any) for various types of meteors ranging from stony to iron spectral types. These efforts have produced primarily empirical mathematical models based on observations. Weaknesses of these models, apart from their empiricism, are reliance on idealized shapes (spheres, cylinders, etc.) and simplified models for thermal response of meteoritic materials to aerodynamic and radiative heating. Furthermore, the fragmentation and energy release of meteors (airburst) is poorly understood. On the other hand, flight of human-made atmospheric entry capsules is well understood. The capsules and their requisite heatshields are designed and margined to survive entry. However, the highest speed Earth entry for capsules is less than 13 km/s (Stardust). Furthermore, Earth entry capsules have never exceeded diameters of 5 m, nor have their peak aerothermal environments exceeded 0.3 atm and 1 kW/cm2. The aims of the current work are: (i) to define the aerothermal environments for objects with entry velocities from 13 to greater than 20 km/s; (ii) to explore various hypotheses of fragmentation and airburst of stony meteors in the near term; (iii) to explore the possibility of performing relevant ground-based tests to verify candidate hypotheses; and (iv) to quantify the energy released in airbursts. The results of the new simulations will be used to anchor said risk assessment analyses. With these aims in mind, state-of-the-art entry capsule design tools are being extended for meteor entries. We describe: (i) applications of current simulation tools to spherical geometries of diameters ranging from 1 to 100 m for an entry velocity of 20 km/s and stagnation pressures ranging from 1 to 100 atm; (ii) the influence of shape and departure of heating environment predictions from those for a simple spherical geometry; (iii) assessment of thermal response models for silica subject to intense radiation; and (iv) results for porosity-driven gross fragmentation of meteors, idealized as a collection of smaller objects. Lessons learned from these simulations will be used to help understand the Chelyabinsk meteor entry up to its first point of fragmentation.

  2. Approximate renormalization for the break-up of invariant tori with three frequencies

    E-print Network

    C. Chandre; R. S. MacKay

    2000-01-17

    We construct an approximate renormalization transformation for Hamiltonian systems with three degrees of freedom in order to study the break-up of invariant tori with three incommensurate frequencies which belong to the cubic field $Q(\\tau)$, where $\\tau^3+\\tau^2-2\\tau-1=0$. This renormalization has two fixed points~: a stable one and a hyperbolic one with a codimension one stable manifold. We compute the associated critical exponents that characterize the universality class for the break-up of the invariant tori we consider.

  3. Cusping, capture, and breakup of interacting drops by a curvatureless boundary-integral algorithm

    NASA Astrophysics Data System (ADS)

    Zinchenko, Alexander Z.; Rother, Michael A.; Davis, Robert H.

    1999-07-01

    A three-dimensional boundary-integral algorithm for interacting deformable drops in Stokes flow is developed. The algorithm is applicable to very large deformations and extreme cases, including cusped interfaces and drops closely approaching breakup. A new, curvatureless boundary-integral formulation is used, containing only the normal vectors, which are usually much less sensitive than is the curvature to discretization errors. A proper regularization makes the method applicable to small surface separations and arbitrary [lambda], where [lambda] is the ratio of the viscosities of the drop and medium. The curvatureless form eliminates the difficulty with the concentrated capillary force inherent in two-dimensional cusps and allows simulation of three-dimensional drop/bubble motions with point and line singularities, while the conventional form can only handle point singularities. A combination of the curvatureless form and a special, passive technique for adaptive mesh stabilization allows three-dimensional simulations for high aspect ratio drops closely approaching breakup, using highly stretched triangulations with fixed topology. The code is applied to study relative motion of two bubbles or drops under gravity for moderately high Bond numbers [script B], when cusping and breakup are typical. The deformation-induced capture efficiency of bubbles and low-viscosity drops is calculated and found to be in reasonable agreement with available experiments of Manga & Stone (1993, 1995b). Three-dimensional breakup of the smaller drop due to the interaction with a larger one for [lambda]=O(1) is also considered, and the algorithm is shown to accurately simulate both the primary breakup moment and the volume partition by extrapolation for moderately supercritical conditions. Calculations of the breakup efficiency suggest that breakup due to interactions is significant in a sedimenting emulsion with narrow size distribution at [lambda]=O(1) and [script B][gt-or-equal, slanted]5 10. A combined capture and breakup phenomenon, when the smaller drop starts breaking without being released from the dimple formed on the larger one, is also observed in the simulations. A general classification of possible modes of two-drop interactions for [lambda]=O(1) is made.

  4. Experimental deuteron momentum distributions with reduced final state interactions

    NASA Astrophysics Data System (ADS)

    Khanal, Hari P.

    This dissertation presents a study of the D( e, e'p)n reaction carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfer Q 2 = 2.1 and 0.8 (GeV/c)2 and for missing momenta pm ranging from pm = 0.03 to pm = 0.65 GeV/c. The analysis resulted in the determination of absolute D(e,e' p)n cross sections as a function of the recoiling neutron momentum and it's scattering angle with respect to the momentum transfer [vector] q. The angular distribution was compared to various modern theoretical predictions that also included final state interactions. The data confirmed the theoretical prediction of a strong anisotropy of final state interaction contributions at Q2 of 2.1 (GeV/c)2 while at the lower Q2 value, the anisotropy was much less pronounced. At Q2 of 0.8 (GeV/c)2, theories show a large disagreement with the experimental results. The experimental momentum distribution of the bound proton inside the deuteron has been determined for the first time at a set of fixed neutron recoil angles. The momentum distribution is directly related to the ground state wave function of the deuteron in momentum space. The high momentum part of this wave function plays a crucial role in understanding the short-range part of the nucleon-nucleon force. At Q2 = 2.1 (GeV/c)2, the momentum distribution determined at small neutron recoil angles is much less affected by FSI compared to a recoil angle of 75°. In contrast, at Q2 = 0.8 (GeV/c)2 there seems to be no region with reduced FSI for larger missing momenta. Besides the statistical errors, systematic errors of about 5--6 % were included in the final results in order to account for normalization uncertainties and uncertainties in the determi- nation of kinematic veriables. The measurements were carried out using an electron beam energy of 2.8 and 4.7 GeV with beam currents between 10 to 100 ? A. The scattered electrons and the ejected protons originated from a 15cm long liquid deuterium target, and were detected in conicidence with the two high resolution spectrometers of Hall A at Jefferson Lab.

  5. Field and experimental constraints on the deformation and break-up up of injected magma (Invited)

    NASA Astrophysics Data System (ADS)

    Hodge, K. F.; Carazzo, G.; Jellinek, M.

    2010-12-01

    Understanding the mechanics that control mafic schlieren and enclave formation is a central issue in volcanology for interpreting the conditions of the unerupted material in a chamber. Field observations from the Tuolumne Intrusive Suite (TIS), USA, demonstrate that meter-scale migrating tubes, or “ladder dikes,” can be strongly deformed by shearing motions in the magma chamber. These delicate features offer preserved length scales of deformation that can be used to infer fundamental quantities controlling the rheology of silicic magma. Here we investigate what governs the dynamics of these tube-like structures in a shear flow using analog experiments, which are motivated by field observations from the TIS. Using variations in yield strength of the injected material, buoyancy, and ambient flow behavior, we aim to characterize the deformation of the tubes under a wide range of conditions. The experiments are conducted in an 8 cm high and 60 cm wide cylindrical tank. In all experiments the tank is filled to a depth of 7 cm with corn syrup (? = 1430 kg/m3, µ = 280 Pa s). A rigid rotating plate is driven from above by an external motor creating a simple shear flow in the corn syrup with rotation speeds varying between 0.08 - 12 rpm. The experiment involves a downward injection of a controlled volume of a particle-fluid mixture. The fluid is the same corn syrup used for the ambient fluid and the particles are glass powder (? = 2600 kg/m3, d = 1µm) and zirconium silicate spheres (? = 3600 kg/m3, d=0.4mm). Our results show that the particle-fluid tube may follow two end-member regimes depending on the shear stress/buoyancy force ratio (V*) and the viscous stress/yield stress ratio (R) imposed initially. At low R values (< 1) and low V* values (<100) as well as all R values for V* > 100, the injected tube becomes gravitationally unstable and breaks up into blobs separated by thin strands of interstitial tube material. At high R values (> 1) and low V* values (<100), the injected tube is too stiff and does not go unstable or breakup. Initial field observations of migrating tubes (Paterson 2009) in the TIS suggest that the break-up of these features can be linked to the yield strength of the magma during deformation. Here, we present a field investigation that includes detailed mapping of ~100 migrating tubes in the Cathedral Peak Granite (along with some tubes in the Half Dome granite). Preliminary results suggest that a few long tubes appear to have been broken up into regularly spaced sections. Interestingly, the majority of the mapped tubes (specifically where they occur in large clusters) are located near a contact with either host rock or another intrusive unit in the TIS and are oriented roughly perpendicular to that contact. The preserved length scales of deformation are compared to experimental regimes in which tubes break up into blobs.

  6. Transient Droplet Behavior and Droplet Breakup during Bulk and Confined Shear Flow in Blends with One Viscoelastic Component: Experiments, Modelling and Simulations

    SciTech Connect

    Cardinaels, Ruth; Verhulst, Kristof; Moldenaers, Paula [Katholieke Universiteit Leuven, Department of Chemical Engineering, W. de Croylaan 46, B-3001 Leuven (Belgium); Renardy, Yuriko [Polytechnic lnstitute and State University, Department of Mathematics and ICAM, 460 McBryde Hall, Blackburg VA 24061-0123 (United States)

    2008-07-07

    The transient droplet deformation and droplet orientation after inception of shear, the shape relaxation after cessation of shear and droplet breakup during shear, are microscopically studied, both under bulk and confined conditions. The studied blends contain one viscoelastic Boger fluid phase. A counter rotating setup, based on a Paar Physica MCR300, is used for the droplet visualisation. For bulk shear flow, it is shown that the droplet deformation during startup of shear flow and the shape relaxation after cessation of shear flow are hardly influenced by droplet viscoelasticity, even at moderate to high capillary and Deborah numbers. The effects of droplet viscoelasticity only become visible close to the critical conditions and a novel break-up mechanism is observed. Matrix viscoelasticity has a more pronounced effect, causing overshoots in the deformation and significantly inhibiting relaxation. However, different applied capillary numbers prior to cessation of shear flow, with the Deborah number fixed, still result in a single master curve for shape retraction, as in fully Newtonian systems. The long tail in the droplet relaxation can be qualitatively described with a phenomenological model for droplet deformation, when using a 5-mode Giesekus model for the fluid rheology. It is found that the shear flow history significantly affects the droplet shape evolution and the breakup process in blends with one viscoelastic component. Confining a droplet between two plates accelerates the droplet deformation kinetics, similar to fully Newtonian systems. However, the increased droplet deformation, due to wall effects, causes the steady state to be reached at a later instant in time. Droplet relaxation is less sensitive to confinement, leading to slower relaxation kinetics only for highly confined droplets. For the blend with a viscoelastic droplet, a non-monotonous trend is found for the critical capillary number as a function of the confinement ratio. Finally, experimental data are compared with 3D simulations, performed with a volume-of-fluid algorithm.

  7. Transient Droplet Behavior and Droplet Breakup during Bulk and Confined Shear Flow in Blends with One Viscoelastic Component: Experiments, Modelling and Simulations

    NASA Astrophysics Data System (ADS)

    Cardinaels, Ruth; Verhulst, Kristof; Renardy, Yuriko; Moldenaers, Paula

    2008-07-01

    The transient droplet deformation and droplet orientation after inception of shear, the shape relaxation after cessation of shear and droplet breakup during shear, are microscopically studied, both under bulk and confined conditions. The studied blends contain one viscoelastic Boger fluid phase. A counter rotating setup, based on a Paar Physica MCR300, is used for the droplet visualisation. For bulk shear flow, it is shown that the droplet deformation during startup of shear flow and the shape relaxation after cessation of shear flow are hardly influenced by droplet viscoelasticity, even at moderate to high capillary and Deborah numbers. The effects of droplet viscoelasticity only become visible close to the critical conditions and a novel break-up mechanism is observed. Matrix viscoelasticity has a more pronounced effect, causing overshoots in the deformation and significantly inhibiting relaxation. However, different applied capillary numbers prior to cessation of shear flow, with the Deborah number fixed, still result in a single master curve for shape retraction, as in fully Newtonian systems. The long tail in the droplet relaxation can be qualitatively described with a phenomenological model for droplet deformation, when using a 5-mode Giesekus model for the fluid rheology. It is found that the shear flow history significantly affects the droplet shape evolution and the breakup process in blends with one viscoelastic component. Confining a droplet between two plates accelerates the droplet deformation kinetics, similar to fully Newtonian systems. However, the increased droplet deformation, due to wall effects, causes the steady state to be reached at a later instant in time. Droplet relaxation is less sensitive to confinement, leading to slower relaxation kinetics only for highly confined droplets. For the blend with a viscoelastic droplet, a non-monotonous trend is found for the critical capillary number as a function of the confinement ratio. Finally, experimental data are compared with 3D simulations, performed with a volume-of-fluid algorithm.

  8. Note on the breakup of immersed threads in the absence of viscosity differences

    E-print Network

    Eindhoven, Technische Universiteit

    in a fluid of viscosity 2. He investigated a thread surrounded by air, so that effectively the viscosity1 Note on the breakup of immersed threads in the absence of viscosity differences By A. Y. G U N case of threads and fluid having equal viscosities. Due to surface tension, the threads will break up

  9. Analyzing the tradeoffs between breakup and cloning in the context of organizational self-design

    E-print Network

    Allan, Vicki H.

    Analyzing the tradeoffs between breakup and cloning in the context of organizational self kamboj@cis.udel.edu ABSTRACT Organizational Self-Design (OSD) has been proposed as an ap- proach organizational structures. OSD has also been shown to be especially suited for environments that are dynamic

  10. Breakup and fusion of {sup 6}Li and {sup 6}He with {sup 208}Pb

    SciTech Connect

    Rusek, K.; Alamanos, N.; Keeley, N.; Lapoux, V.; Pakou, A. [Department of Nuclear Reactions, Andrzej Soltan Institute for Nuclear Studies, Hoza, 69, 00-681 Warsaw (Poland); DSM/DAPNIA/SPhN CEA-Saclay, 91191 Gif-sur-Yvette (France); Department of Physics, University of Ioannina, 45110 Ioannina (Greece)

    2004-07-01

    The effect of {sup 6}Li and {sup 6}He breakup on the fusion cross section of these nuclei with {sup 208}Pb is investigated by means of continuum-discretized coupled-channels (CDCC) calculations. For {sup 6}Li the calculations describe reasonably well the experimental data for elastic scattering, {sup 6}Li{yields}{alpha}+d breakup and the absorption cross section given by the sum of the {sup 6}Li fusion and the {alpha} production cross section not attributed to breakup. The effect of {sup 6}Li breakup on the calculated absorption cross section is found to depend strongly on the imaginary part of the diagonal bare potential. A combination of the CDCC technique and the barrier penetration model generates results close to the measured fusion cross section. For {sup 6}He the calculated absorption cross section is much larger than the measured {sup 6}He+{sup 209}Bi complete fusion cross section values. However, it is found to be relatively independent of the form of the imaginary part of the bare potential. The complete fusion cross section is again found to be reasonably well described by the CDCC/BPM combination.

  11. A GEOCLIM simulation of climatic and biogeochemical consequences of Pangea breakup

    E-print Network

    Pierrehumbert, Raymond

    A GEOCLIM simulation of climatic and biogeochemical consequences of Pangea breakup Y. Donnadieu. Pierrehumbert, G. Dromart, F. Fluteau, and R. Jacob (2006), A GEOCLIM simulation of climatic and biogeochemical Laboratoire des Sciences du Climat et de l'Environnement, CNRS-CEA, CEA Saclay, Orme des Merisiers, Bat. 701

  12. Effect of inertia on drop breakup under shear Yuriko Y. Renardya)

    E-print Network

    oscillations towards equilibrium analogous to a one-dimensional mass-spring system. The stationary dropARTICLES Effect of inertia on drop breakup under shear Yuriko Y. Renardya) Department A spherical drop, placed in a second liquid of the same density and viscosity, is subjected to shear between

  13. Numerical simulations of the early stages of high-speed droplet breakup

    NASA Astrophysics Data System (ADS)

    Meng, J. C.; Colonius, T.

    2015-07-01

    Experiments reported in the literature are reproduced using numerical simulations to investigate the early stages of the breakup of water cylinders in the flow behind normal shocks. Qualitative features of breakup observed in the numerical results, such as the initial streamwise flattening of the cylinder and the formation of tips at its periphery, support previous experimental observations of stripping breakup. Additionally, the presence of a transitory recirculation region at the cylinder's equator and a persistent upstream jet in the wake is noted and discussed. Within the uncertainties inherent to the different methods used to extract measurements from experimental and numerical results, comparisons with experimental data of various cylinder deformation metrics show good agreement. To study the effects of the transition between subsonic and supersonic post-shock flow, we extend the range of incident shock Mach numbers beyond those investigated by the experiments. Supersonic post-shock flow velocities are not observed to significantly alter the cylinder's behavior, i.e., we are able to effectively collapse the drift, acceleration, and drag curves for all simulated shock Mach numbers. Using a new method that minimizes noise errors, the cylinder's acceleration is calculated; acceleration curves for all shock Mach numbers are subsequently collapsed by scaling with the pressure ratio across the incident shock. Furthermore, we find that accounting for the cylinder's deformed diameter in the calculation of its unsteady drag coefficient allows the drag coefficient to be approximated as a constant over the initial breakup period.

  14. Discovery Of Main-belt Asteroid Breakups Occurring Within The Last 1 My

    Microsoft Academic Search

    David Vokrouhlicky; D. Nesvorny; W. F. Bottke

    2006-01-01

    Here we report the discovery of four new and very recent asteroid breakups in the main belt, all which occurred within the last My. To identify these asteroid mini-families, we looked for similarities in their osculating orbital elements (except mean anomaly). We selected 264,403 asteroids from the Lowell Observatory catalog that have observational arcs longer than 10 days, and we

  15. EXPERIMENTAL INVESTIGATION OF BEAM BREAKUP IN THE JEFFERSON LABORATORY 10 kW FEL UPGRADE DRIVER*

    E-print Network

    Hoffstaetter, Georg

    . Tennant# , D. Douglas, K. Jordan, L. Merminga, E. Pozdeyev, H. Wang Thomas Jefferson National AcceleratorEXPERIMENTAL INVESTIGATION OF BEAM BREAKUP IN THE JEFFERSON LABORATORY 10 kW FEL UPGRADE DRIVER* C. Experimental observations of the instability at the Jefferson Laboratory 10 kW Free-Electron Laser (FEL

  16. Experimental investigation of multibunch, multipass beam breakup in the Jefferson Laboratory Free Electron Laser Upgrade Driver

    E-print Network

    Hoffstaetter, Georg

    , Christopher D. Tennant,* and Haipeng Wang Thomas Jefferson National Accelerator Facility, Newport NewsExperimental investigation of multibunch, multipass beam breakup in the Jefferson Laboratory Free at the Jefferson Laboratory 10 kW free electron laser (FEL) are presented. Measurements of the threshold current

  17. In-situ detections of a satellite breakup by the SPADUS instrument

    Microsoft Academic Search

    A. J. Tuzzolino; R. B. McKibben; J. A. Simpson; S. Benzvi; H. D. Voss; H. Gursky; N. L. Johnson

    2001-01-01

    For the first time, a particle detector in Earth orbit has provided evidence to directly link sub-millimeter orbital debris to a specific satellite breakup. The University of Chicago's Space Dust Instrument (SPADUS), on the U.S. Air Force's Advanced Research and Global Observation Satellite, has been operating in a nearly polar orbit, at an altitude of about 830 km, since soon

  18. Seismic tomography, surface uplift, and the breakup of Gondwanaland: Integrating mantle convection backwards in

    E-print Network

    Conrad, Clint

    Seismic tomography, surface uplift, and the breakup of Gondwanaland: Integrating mantle convection 91125, USA (gurnis@gps.caltech.edu) [1] Mantle density heterogeneities, imaged using seismic tomography, contain information about time- dependent mantle flow and mantle structures that existed in the past. We

  19. Droplet impingement and breakup on a dry surface Amit Gupta, Ranganathan Kumar *

    E-print Network

    Gupta, Amit

    , the size of the droplet, the angle of attack to the surface, the physical properties of the liquid dropDroplet impingement and breakup on a dry surface Amit Gupta, Ranganathan Kumar * Department. Introduction Collision of droplet(s) on solid or liquid surfaces is a phenome- non that occurs widely in nature

  20. Relative Timing of CAMP, Rifting, Continental Breakup, and Basin Inversion: Tectonic Significance

    E-print Network

    Olsen, Paul E.

    1 Relative Timing of CAMP, Rifting, Continental Breakup, and Basin Inversion: Tectonic Significance in eastern North America provides a temporal benchmark for assessing the relative timing of rifting, drift, and geochronological data favor a diachronous rift-drift transition (seafloor spreading began earlier in the south

  1. Drop formation and breakup of low viscosity elastic fluids: Effects of molecular weight and concentration

    E-print Network

    Drop formation and breakup of low viscosity elastic fluids: Effects of molecular weight fluids all exhibit the same global necking behavior that is observed for a Newtonian fluid of equivalent, as would occur in the equivalent Newtonian fluid. Alternatively, a cylindrical filament forms in which

  2. Molecular dynamics simulation of thread break-up and formation of droplets in nanoejection system

    Microsoft Academic Search

    Chi-Fu Dai; Rong-Yeu Chang

    2009-01-01

    This study investigated nanojet processes by a non-equilibrium molecular dynamics simulation. The phenomena of liquid thread break-up and droplet formation were simulated by compressing liquid propane molecules with various compressing velocities. Properties' distributions show that, at the nanoscale, density and pressure were neither uniform nor continuous during the ejection process. Shear heating phenomena were found in the contact area of

  3. Characterization of the 2012-044C Briz-M Upper Stage Breakup

    NASA Technical Reports Server (NTRS)

    Matney, M. J.; Hamilton, J.; Horstman, M.; Papanyan, V.

    2013-01-01

    On 6 August, 2012, Russia launched two commercial satellites aboard a Proton rocket, and attempted to place them in geosynchronous orbit using a Briz-M upper stage (2012-044C, SSN 38746). Unfortunately, the upper stage failed early in its burn and was left stranded in an elliptical orbit with a perigee in low Earth orbit (LEO). Because the stage failed with much of its fuel on board, it was deemed a significant breakup risk. These fears were confirmed when it broke up 16 October, creating a large cloud of debris with perigees below that of the International Space Station. The debris cloud was tracked by the US Space Surveillance Network (SSN), which can reliably detect and track objects down to about 10 cm in size. Because of the unusual geometry of the breakup, there was an opportunity for NASA Orbital Debris Program Office to use specialized radar assets to characterize the extent of the debris cloud in sizes smaller than the standard debris tracked by the SSN. This paper will describe the observation campaign to measure the small particle distributions of this cloud, and presents the results of the analysis of the data. We shall compare the data to the modelled size distribution, number, and shape of the cloud, and what implications this may have for future breakup debris models. We shall conclude the paper with a discussion how this measurement process can be improved for future breakups.

  4. Type of Writing Task and College Students' Meaning Making Following a Romantic Breakup

    ERIC Educational Resources Information Center

    Primeau, Joanna E.; Servaty-Seib, Heather L.; Enersen, Donna

    2013-01-01

    In this study, the authors examined the potential effects of type of writing task (loss/gain vs. general prompt) on the narrative content offered by college students (N = 41) who experienced romantic breakup. Qualitative analyses indicated differences based on type of writing task. Students who received the loss/gain prompt exhibited more…

  5. ROLE OF CATION DEMIXING AND QUASICRYSTAL FORMATION AND BREAKUP ON THE STABILITY OF SMECTITIC COLLOIDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory has been extensively used to explain colloid stability. This study investigated the effect of demixing of monovalent and divalent cations and crystalline swelling on the breakup and formation of smectite quasicrystals (QCs) and how these processes a...

  6. The recent breakup of an asteroid in the main-belt region

    E-print Network

    Nesvorny, David

    .............................................................. The recent breakup of an asteroid ............................................................................................................................................................................. The present population of asteroids in the main belt is largely the result of many past collisions1,2 . Ideally, the asteroid fragments resulting from each impact event could help us understand the large

  7. Effect of interior surface finish on the break-up of commercial shaped charge liners

    SciTech Connect

    Baker, E L; Schwartz, A J

    1999-08-11

    A series of experiments aimed at understanding the influence of the liner interior surface finish on the break-up of shaped charge jets has been completed. The experiments used a standard 81-mm shaped charge design, loaded with LX-14 high explosive; incorporating high-precision copper shaped charged liners. The results indicate that a significant reduction of jet break-up time occurs between a surface finish of 99.30 microinches and 375.65 microinches. Surface finishes of 4.78, 44.54 and 99.30 microinches produced significantly better ductility and associated break-up times than the 375.65-microinch finish. The baseline production process high-precision liners were measured to have an average surface finish of 44.54 microinches. The results show that for the shaped charge warhead geometry and explosive combination investigated, some care must be taken in respect to surface finish, but that very fine surface finishes do not significantly improve the jet ductility and associated break-up times.

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

    ERIC Educational Resources Information Center

    Gilbert, Steven P.; Sifers, Sarah K.

    2011-01-01

    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…

  9. Asymptotic normalization coefficients and spectroscopic factors from deuteron stripping reactions

    NASA Astrophysics Data System (ADS)

    Pang, D. Y.; Mukhamedzhanov, A. M.

    2014-10-01

    We present the analysis of three deuteron stripping reactions, C14(d,p)C15,Ni58(d,p)Ni59, and Sn116(d,p)Sn117 using the combined method [A. M. Mukhamedzhanov and F. M. Nunes, Phys. Rev. C 72, 017602 (2005), 10.1103/PhysRevC.72.017602], in which each reaction is analyzed at low and significantly higher energies. At low energies all these reactions are peripheral and the experimental asymptotic normalization coefficients (ANCs) are determined with accuracy about 10%. At higher energies we determine the spectroscopic factors (SFs) by fixing the normalization of the peripheral parts of the reaction amplitudes governed by the ANCs found from the low-energy data. The combined method imposes a strict limitation on the variation of the geometrical parameters of the single-particle potential, which can be arbitrarily taken in the standard approach. By checking the compatibility of the ANCs and SFs using the combined method we reveal the flaw in the contemporary nuclear reaction theory in treating the nuclear interior, which is the most crucial part in the determination of the SFs.

  10. Radiative corrections to the neutrino-deuteron reactions

    SciTech Connect

    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

    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.

  11. Compton Scattering from the Deuteron below Pion-Production Threshold

    E-print Network

    Luke Myers; John Annand; Jason Brudvik; Gerald Feldman; Kevin Fissum; Harald Grießhammer; Kurt Hansen; Seth Henshaw; Lennart Isaksson; Ramsey Jebali; Michael Kovash; Magnus Lundin; Duncan Middleton; Alan Nathan; Bent Schröder; Sean Stave

    2015-03-27

    Differential cross sections for elastic scattering of photons from the deuteron have recently been measured at the Tagged-Photon Facility at the MAX IV Laboratory in Lund, Sweden. These first new measurements in more than a decade further constrain the isoscalar electromagnetic polarizabilities of the nucleon and provide the first-ever results above 100 MeV, where the sensitivity to the polarizabilities is increased. We add 23 points between 70 and 112 MeV, at angles 60deg, 120deg and 150deg. Analysis of these data using a Chiral Effective Field Theory indicates that the cross sections are both self-consistent and consistent with previous measurements. Extracted values of \\alpha_s = [12.1 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 and \\beta_s = [2.4 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 are obtained from a fit to these 23 new data points. This paper presents in detail the experimental conditions and the data analysis used to extract the cross sections.

  12. Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities

    E-print Network

    M. Lundin; J. -O. Adler; M. Boland; K. Fissum; T. Glebe; K. Hansen; L. Isaksson; O. Kaltschmidt; M. Karlsson; K. Kossert; M. I. Levchuk; P. Lilja; B. Lindner; A. I. L'vov; B. Nilsson; D. E. Oner; C. Poech; S. Proff; A. Sandell; B. Schröder; M. Schumacher; D. A. Sims

    2003-06-13

    Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^\\circ$, $125^\\circ$, and $135^\\circ$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and difference of the isospin-averaged nucleon polarizabilities, $\\alpha_N + \\beta_N = 17.4 \\pm 3.7$ and $\\alpha_N - \\beta_N = 6.4 \\pm 2.4$ (in units of $10^{-4}$ fm$^3$), have been determined. By combining the latter with the global-averaged value for $\\alpha_p - \\beta_p$ and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of $\\alpha_n= 8.8 \\pm 2.4$(total) $\\pm 3.0$(model) and $\\beta_n = 6.5 \\mp 2.4$(total) $\\mp 3.0$(model), respectively.

  13. Mechanism of the sup 6 Li( e , e prime. alpha. ) reaction

    SciTech Connect

    Mitchell, J.H.; Blok, H.P.; Berman, B.L.; Briscoe, W.J.; Daman, M.A.; Ent, R.; Jans, E.; Lapikas, L.; Steijger, J.J.M. (Department of Physics and Astronomy, Vrije Universiteit, de Boelelaan 1081 (1081 HV Amsterdam) The Netherlands National Instituut voor Kernfysica en Hoge-Energiefysica, P. O. Box 41882 (1009 DB Amsterdam) The Netherlands Center for Nuclear Studies, Department of Physics, George Washington University, Washington, D.C. (USA))

    1991-11-01

    The {sup 6}Li({ital e},{ital e}{prime}{alpha}) reaction has been measured in parallel kinematics. The {ital Q}{sup 2} dependence of both the two-body and three-body breakup of {sup 6}Li has been studied at fixed recoil momentum. In addition, the recoil momentum dependence of the two-body {alpha}-{ital d} breakup has been investigated. The data indicate that the reaction mechanism is quasielastic in these kinematics.

  14. Attachment Styles and Personal Growth following Romantic Breakups: The Mediating Roles of Distress, Rumination, and Tendency to Rebound

    PubMed Central

    Marshall, Tara C.; Bejanyan, Kathrine; Ferenczi, Nelli

    2013-01-01

    The purpose of this research was to examine the associations of attachment anxiety and avoidance with personal growth following relationship dissolution, and to test breakup distress, rumination, and tendency to rebound with new partners as mediators of these associations. Study 1 (N?=?411) and Study 2 (N?=?465) measured attachment style, breakup distress, and personal growth; Study 2 additionally measured ruminative reflection, brooding, and proclivity to rebound with new partners. Structural equation modelling revealed in both studies that anxiety was indirectly associated with greater personal growth through heightened breakup distress, whereas avoidance was indirectly associated with lower personal growth through inhibited breakup distress. Study 2 further showed that the positive association of breakup distress with personal growth was accounted for by enhanced reflection and brooding, and that anxious individuals’ greater personal growth was also explained by their proclivity to rebound. These findings suggest that anxious individuals’ hyperactivated breakup distress may act as a catalyst for personal growth by promoting the cognitive processing of breakup-related thoughts and emotions, whereas avoidant individuals’ deactivated distress may inhibit personal growth by suppressing this cognitive work. PMID:24066169

  15. Monitoring ice break-up on the Mackenzie River, Canada, from MODIS Aqua and Terra observations

    NASA Astrophysics Data System (ADS)

    Muhammad, P.; Duguay, C. R.; Kang, K.

    2013-12-01

    Monitoring the response of river ice phenology to variability and changes in high-latitude climate conditions is critical for improving our understanding of northern hydrology and related impacts on geochemical and biological processes. Shorter ice cover duration, thinner ice, and earlier break-up also influence the winter road season, thereby influencing industrial development and the delivery of goods to northern communities. Increased upstream temperatures over the Mackenzie River Basin have caused shorter ice cover seasons, consequently changing the timing and severity of river ice flow in this high-latitude region. This study involves the analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) Level 3 500-m snow products (Aqua and Terra), complemented with 250-m Level 1b data, to monitor ice cover during the break-up period on the Mackenzie River over the 2001-2013 period. Results from the analysis of 10 ice seasons (2003-2012) show that first day ice-off was observed between day of year (DY) 115-125 and ended between DY 145-155, resulting in average melt durations of about 30-40 days. Additional ice-on and ice-off days observed during 2003-2012 resulted from northern flowing entrained river ice that extended the break-up season until DY 155-163. Floating ice flowing northbound could therefore generate multiple periods of ice-cover and ice-free days at the same geographic location. During the ice break-up seasons from 2003-2012, ice melt was initiated by in situ melt over drainage basin (thermodynamic), especially between 61-62o N. However, ice break-up above the 62o N was more dynamically driven. In addition, ice jams were found to be largely controlled by river morphology.

  16. Post-breakup Basin Evolution along the South-Atlantic Margins

    NASA Astrophysics Data System (ADS)

    Strozyk, Frank; Back, Stefan; Kukla, Peter

    2014-05-01

    The post-breakup tectono-stratigraphic evolution of large offshore basins along the South American and African continental margins record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. A regional comparison based on tectonic-stratigraphic analysis of selected seismic transects between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin) provides a comprehensive basin-to-basin documentation of the key geological parameters controlling ocean and continental margin development. This comparison includes the margin configuration, subsidence development through time, sediment influx and storage patterns, type of basin fill (e.g. salt vs. non-salt systems; carbonate-rich vs. clastics-dominated systems) and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development. The diversity in the stratigraphic architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are (a) the structural configuration of each margin segment at the time of break-up, (b) the post break-up subsidence history of the respective margin segment, (c) variations in the type, quantity and distribution of margin sediment, and (d) sea-level changes.

  17. Using Synthetic Aperture Radar to Study River Ice Breakup on the Kuparuk River, Northern Alaska

    NASA Astrophysics Data System (ADS)

    Floyd, A.; Prakash, A.; Meyer, F. J.; Gens, R.; Liljedahl, A. K.

    2012-12-01

    A combined use of remote sensing techniques and in-situ measurements is an effective approach to study Arctic hydrology, given the vastness, complexity, and logistical challenges posed by most Arctic watersheds. Remote sensing techniques can provide tools to assess the geospatial variations that form the integrated response of a river system and, therefore, provide important details to study one of the effects of climate change on the remote Arctic environment. This study investigates the breakup response of the Kuparuk River on the North Slope of Alaska using synthetic aperture radar (SAR). Imagery and runoff data collected during the spring and summer months between 2001 and 2010 from the Lower Kuparuk River are included in the analysis, which totals 65 SAR images. Image processing results have been calibrated with in-situ stream gauge data provided by USGS gauging station 15896000, on the Lower Kuparuk River, near the town of Deadhorse, Alaska. A time series was assembled to examine the breakup initiation in the subsets through statistical analysis. Images were stacked, geocoded using a Fast Fourier Transform, subset, masked, and divided into subsections. The statistics of each subsection were then compiled and analyzed. Arctic river breakup is a dynamic process. Therefore, we expected drastic change in river surface conditions to correspond to a large variance in backscatter between river subsections. However, before and after breakup we expected image subsections to have largely homogenous statistics. This was verified in nearly all of the image sets, although some variance still existed before and after the breakup event as a result of other conflicting variables. Changes in wind velocity, water depth, and size of point bars all contributed to these confounding variances. Combined with a comprehensive field campaign, SAR imagery interpretations have the potential to develop into a useful monitoring tool for monitoring Arctic rivers and developing resource management plans for neighboring communities.

  18. Tear Film Breakup and Structure Studied by Simultaneous Video Recording of Fluorescence and Tear Film Lipid Layer Images

    PubMed Central

    King-Smith, P. Ewen; Reuter, Kathleen S.; Braun, Richard J.; Nichols, Jason J.; Nichols, Kelly K.

    2013-01-01

    Purpose. The thinning of the precorneal tear film between blinks and tear film breakup can be logically analyzed into contributions from three components: evaporation, flow into the cornea, and tangential flow along the corneal surface. Whereas divergent tangential flow contributes to certain types of breakup, it has been argued that evaporation is the main cause of tear thinning and breakup. Because evaporation is controlled by the tear film lipid layer (TFLL) it should therefore be expected that patterns of breakup should match patterns in the TFLL, and this hypothesis is tested in this study. Methods. An optical system is described for simultaneous video imaging of fluorescein tear film breakup and the TFLL. Recordings were made from 85 subjects, including both with healthy and dry eyes. After instillation of 5 ?L2% fluorescein, subjects were asked to blink 1 second after the start of the recording and try to maintain their eyes open for the recording length of 30 or 60 seconds. Results. Areas of tear film thinning and breakup usually matched corresponding features in the TFLL. Whereas thinning and breakup were often matched to thin lipid, surprisingly, the corresponding lipid region was not always thinner than the surrounding lipid. Occasionally, a thin lipid region caused a corresponding region of greater fluorescence (thicker aqueous layer), due to convergent tangential flow. Conclusions. Areas of tear thinning and breakup can generally be matched to corresponding regions of the TFLL as would be expected if breakup is largely due to evaporation. Surprisingly, in some examples, the corresponding lipid area was not thinner and possibly thicker than the surrounding lipid. This indicates that the lipid was a poor barrier to evaporation, perhaps because of deficiency in composition and/or structure. For example, bacterial lipases may have broken down esters into component acids and alcohols, causing a defective TFLL structure with increased evaporation. PMID:23766476

  19. Deuteron binding energies and form factors from light-front Hamiltonian field theory

    NASA Astrophysics Data System (ADS)

    Cooke, Jason R.; Miller, Gerald A.

    2002-09-01

    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.

  20. Breakup of a supercontinent between 625 Ma and 555 Ma - New evidence and implications for continental histories

    NASA Astrophysics Data System (ADS)

    Bond, G. C.; Nickeson, P. A.; Kominz, M. A.

    1984-10-01

    Tectonic subsidence histories for the early Paleozoic miogeoclines support hypotheses that pertain to the existence and fragmentation of a late Proterozoic supercontinent, and suggest novel, testable hypotheses for the configuration of such a landmass and the timing of a major phase in its eventual breakup and dispersal. Analyses of tectonic subsidence constrain the timing of a widespread episode of continental breakup to a relatively narrow interval between 625 and 555 Ma. It is concluded that the geologic evidence of the breakup event in early Paleozoic miogeoclines occurs in strata of Vendian and earliest Cambrian age.

  1. Simulation of Motion, Heating, and Breakup of Molten Metal Droplets in the Plasma Jet at Plasma-Arc Spraying

    NASA Astrophysics Data System (ADS)

    Kharlamov, M. Yu.; Krivtsun, I. V.; Korzhyk, V. N.; Ryabovolyk, Y. V.; Demyanov, O. I.

    2015-04-01

    The mathematical model for the process of plasma-arc wire spraying is proposed, which describes behavior of molten metal droplets in the plasma jet, allowing for the processes of their deformation and gas-dynamic breakup. Numerical analysis of the processes of motion, heating, and breakup of molten metal droplets, detached from the sprayed wire at plasma-arc spraying of coatings, was performed. It is shown that during molten droplets movement in the plasma jet their multiple breakup takes place, leading to formation of sprayed particles with dimensions much smaller than dimensions of initial droplets, detached from the sprayed wire tip.

  2. Deuteron elastic and inelastic scattering from 12C, 24Mg, and 58Ni at 170 MeV

    NASA Astrophysics Data System (ADS)

    Bäumer, C.; Bassini, R.; van den Berg, A. M.; de Frenne, D.; Frekers, D.; Hagemann, M.; Hannen, V. M.; Harakeh, M. N.; Heyse, J.; de Huu, M. A.; Jacobs, E.; Mielke, M.; Rakers, S.; Schmidt, R.; Sohlbach, H.; Wörtche, H. J.

    2001-03-01

    Angular distributions for elastic and inelastic deuteron scattering on 12C, 24Mg, and 58Ni have been measured at a bombarding energy of 170 MeV. The data are analyzed in terms of the optical model. The extracted optical model parameters are compared to existing deuteron global optical potentials.

  3. Dominant deuteron acceleration with a high-intensity laser for isotope production and neutron generation

    SciTech Connect

    Maksimchuk, A.; Raymond, A.; Yu, F.; Dollar, F.; Willingale, L.; Zulick, C.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Petrov, G. M.; Davis, J. [Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375 (United States)] [Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375 (United States)

    2013-05-13

    Experiments on the interaction of an ultra-short pulse laser with heavy-water, ice-covered copper targets, at an intensity of 2 Multiplication-Sign 10{sup 19} W/cm{sup 2}, were performed demonstrating the generation of a 'pure' deuteron beam with a divergence of 20 Degree-Sign , maximum energy of 8 MeV, and a total of 3 Multiplication-Sign 10{sup 11} deuterons with energy above 1 MeV-equivalent to a conversion efficiency of 1.5%{+-} 0.2%. Subsequent experiments on irradiation of a {sup 10}B sample with deuterons and neutron generation from d-d reactions in a pitcher-catcher geometry, resulted in the production of {approx}10{sup 6} atoms of the positron emitter {sup 11}C and a neutron flux of (4{+-}1) Multiplication-Sign 10{sup 5} neutrons/sterad, respectively.

  4. Y-Scaling Analysis of the Deuteron Within the Light-Front Dynamics Method

    E-print Network

    M. K. Gaidarov; M. V. Ivanov; A. N. Antonov

    2002-07-28

    The concept of relativistic scaling is applied to describe the most recent data from inclusive electron-deuteron scattering at large momentum transfer. We calculate the asymptotic scaling function f(y) of the deuteron using its relationship with the nucleon momentum distribution. The latter is obtained in the framework of the relativistic light-front dynamics (LFD) method, in which the deuteron is described by six invariant functions f_{i} (i=1,...,6) instead of two (S and D waves) in the nonrelativistic case. Comparison of the LFD asymptotic scaling function with other calculations using $S$ and $D$ waves corresponding to various nucleon-nucleon potentials, as well as with the Bethe-Salpeter result is made. It is shown that for |y|> 400 MeV/c the differences between the LFD and the nonrelativistic scaling functions become larger.

  5. Observation of neutron spectrum produced by fast deuterons via ultraintense laser plasma interactions.

    PubMed

    Izumi, N; Sentoku, Y; Habara, H; Takahashi, K; Ohtani, F; Sonomoto, T; Kodama, R; Norimatsu, T; Fujita, H; Kitagawa, Y; Mima, K; Tanaka, K A; Yamanaka, T

    2002-03-01

    We report the first precise spectral measurement of fast neutrons produced in a deuterated plastic target irradiated by an ultraintense sub-picosecond laser pulse. The 500-fs, 50-J, 1054-nm laser pulse was focused on the deuterated polystyrene target with an intensity of 2 x 10(19) W/cm(2). The neutron spectra were observed at 55 degrees and 90 degrees to the rear target normal. The neutron emission was 7 x 10(4) per steradian for each detector. The observed neutron spectra prove the acceleration of deuterons and neutron production by d(d,n)3He reactions in the target. The neutron spectra were compared with Monte Carlo simulation results and the deuteron's directional anisotropy and energy spectrum were studied. We conclude that 2% of the laser energy was converted to deuterons, which has an energy range of 30 keV up to 3 MeV. PMID:11909268

  6. Production of a Beam of Tensor-Polarized Deuterons Using a Carbon Target

    NASA Astrophysics Data System (ADS)

    Seyfarth, H.; Engels, R.; Rathmann, F.; Ströher, H.; Baryshevsky, V.; Rouba, A.; Düweke, C.; Emmerich, R.; Imig, A.; Grigoryev, K.; Mikirtychiants, M.; Vasilyev, A.

    2010-06-01

    An initially unpolarized beam of deuterons is found to acquire tensor polarization after traversing a foil of spin-zero target nuclei. The effect, called nuclear spin dichroism, has been predicted theoretically, albeit resulting in small values of pzz of the order of 0.01 for energies around 10 MeV. The experiment was carried out at the Köln tandem accelerator using carbon targets bombarded by deuterons. The observed polarization is as large as pzz=-0.28±0.03 for a beam of 14.8 MeV and a 129mg/cm2 target. The results allow one to produce tensor-polarized deuterons with pzz around -0.30 (or +0.25) from an initially unpolarized beam using a carbon target of appropriate thickness.

  7. Study of the Two-pion Photoproduction on the Deuteron

    SciTech Connect

    Graham, Lewis P. [South Carolina U.

    2012-12-01

    Understanding the structure of baryons in terms of the fundamental interaction of the constituent quarks and gluons is one of the primary challenges in strong interaction physics. This interaction is governed by Quantum Chromodynamics (QCD), which is a theory for understanding the dynamics of strong. QCD displays the asymptotic freedom of hadrons at very short distances and also the confinement of quarks and gluons inside hadrons. However, solutions of this QCD theory in the non-perturbative domain of the interaction are extremely difficult to achieve, mainly because confinement happens on the hadronic scale on which the coupling constant is large and prevents any perturbative approach. Thus leaving us with strategies such as lattice QCD or formulating QCD sum rules to get around this problem. In exclusive hadron production the yN interaction is recognized for being a powerful method for investigating hadrons and the mysteries that still exist within the strong interaction. From reactions with the nucleon, the strong interaction can be investigated through the transition amplitudes to the N and Delta resonances. More specifically, if an electromagnetic interaction is well known then the intermediate resonance states may be evaluated through meson photoproduction. To gain more detailed insight into this interaction, we look to probe the baryon structure of the nucleon and the photo-excited resonance decays through photon scattering off a deuteron producing two pions in the final state. This photoproduction process off the deuteron will be used to investigate known baryon resonances in the two pion channel. The two pion final state will be investigated for unraveling new information into the photo-coupling strengths. We want to explore final state interactions, search for properties of known resonances, and to explore the possibility of seeing missing states that are predicted by quark models but have not yet been found experimentally. Using the CEBAF Large Acceptance Spectrometer (CLAS), the hadronic products are detected in coincidence with the incident scattered photon on a deuterium target. This makes it possible to measure the single differential cross sections and the decay angular distributions for the production of two pion final states. The measured cross sections will contribute significantly to a better understanding of the coupling strengths that govern the baryonic and mesonic resonances which will push the knowledge of the strong interaction to a next level. We use CLAS to study the two pion channel from the eg3 data set, for resonance production, specifically investigating the exclusive reaction of yd --> p pi^+pi^?n, and comparing the relevant cross sections to already existing data sets. The eg3 data set provided an excellent data set for investigating photo-induced baryonic and mesonic resonances. It contains a large photon tagging range from 1.1 to 5.5 GeV in the study of photo-coupling strengths, as well as an available two pion reaction channel for resonant decay study. These measurements provide unique and coherent results from tagged photons over a broad range of energy, and represent the only two pion production data above 5 GeV at this present time. We found that the data produced good comparable single-differentials cross sections to other existing CLAS (gll dataset) two pion differential cross sections, and an excellent comparable total cross section to published (ELSA and ABBHHM) two pion total cross sections.

  8. Inelastic stopping for deuterons in warm Al plasmas

    NASA Astrophysics Data System (ADS)

    He, Bin; Liu, Chun-Lei; Liu, Ling; Wang, Jian-Guo

    2015-06-01

    The inelastic stopping is studied for deuterons in the Al plasmas with a fixed density 0.02 g cm?3 at 7 different temperatures from 2.7 to 64 eV within the projectile energy range from 100 keV u?1 to 10 MeV u?1 from our model (He and Wang 2014 Phys. Plasmas 21 063111). All the results are compared in detail with those from the isolated ion model where all the bound electrons are assumed in the ground state and the target ions are in almost the same charge states as those in the plasmas. The relativistic plane wave Born approximation is tested by much improved methods and found to be able to describe well the inelastic processes in the plasmas. The relevant result of the inelastic stopping is found to reflect the joint effect of the transition probability, electron occupation number and transition energy. It is found that the transitions of the deeply bound states play a dominant role to the inelastic stopping in the two models. The results due to all the excitation and de-excitation and those due to all the ionization and three body recombination in the plasmas are usually lower and higher than those for the corresponding isolated ions, respectively. It is demonstrated that models with target ions in the ground state could agree well with experiments in plasmas at a high enough projectile energy provided by a proper choice of the charge state of the target ion. The obvious difference between our model and Casas et al's model (Casas et al 2013 Phys. Rev. E 88 033102) is seen for the stopping with the projectile energy around 100 keV u?1 due to the different physical picture underlying them, which is helpful to probe which model proves more reliable in future experiments.

  9. Nucleon momentum distribution in deuteron and other nuclei within the light-front dynamics method

    E-print Network

    A. N. Antonov; M. Gaidarov; M. V. Ivanov; D. N. Kadrev; G. Z. Krumova; P. E. Hodgson; H. V. von Geramb

    2001-11-09

    The relativistic light-front dynamics (LFD) method has been shown to give a correct description of the most recent data for the deuteron monopole and quadrupole charge form factors obtained at the Jefferson Laboratory for elastic electron-deuteron scattering for six values of the squared momentum transfer between 0.66 and 1.7 (GeV/c)$^{2}$. The good agreement with the data is in contrast with the results of the existing non-relativistic approaches. In this work we firstly make a complementary test of the LFD applying it to calculate another important characteristic, the nucleon momentum distribution $n(q)$ of the deuteron using six invariant functions $f_{i}$ $(i=1,...,6)$ instead of two ($S$- and $D$-waves) in the nonrelativistic case. The comparison with the $y$-scaling data shows the decisive role of the function $f_{5}$ which at $q\\geq$ 500 MeV/c exceeds all other $f$-functions (as well as the $S$- and $D$-waves) for the correct description of $n(q)$ of the deuteron in the high-momentum region. Comparison with other calculations using $S$- and $D$-waves corresponding to various nucleon-nucleon potentials is made. Secondly, using clear indications that the high-momentum components of $n(q)$ in heavier nuclei are related to those in the deuteron, we develop an approach within the natural orbital representation to calculate $n(q)$ in $(A,Z)$-nuclei on the basis of the deuteron momentum distribution. As examples, $n(q)$ in $^{4}$He, $^{12}$C and $^{56}$Fe are calculated and good agreement with the $y$-scaling data is obtained.

  10. Nucleon momentum distribution in deuteron and other nuclei within the light-front dynamics method

    NASA Astrophysics Data System (ADS)

    Antonov, A. N.; Gaidarov, M. K.; Ivanov, M. V.; Kadrev, D. N.; Krumova, G. Z.; Hodgson, P. E.; von Geramb, H. V.

    2002-02-01

    The relativistic light-front dynamics (LFD) method has been shown to give a correct description of the most recent data for the deuteron monopole and quadrupole charge form factors obtained at the Jefferson Laboratory for elastic electron-deuteron scattering for six values of the squared momentum transfer between 0.66 and 1.7 (GeV/c)2. The good agreement with the data is in contrast with the results of the existing nonrelativistic approaches. In this work we first make a complementary test of the LFD applying it to calculate another important characteristic, the nucleon momentum distribution n(q) of the deuteron, using six invariant functions fi (i=1,...,6) instead of two (S and D waves) in the nonrelativistic case. The comparison with the y-scaling data shows the decisive role of the function f5 which at q>=500 MeV/c exceeds all other f functions (as well as the S and D waves) for the correct description of n(q) of the deuteron in the high-momentum region. Comparison with other calculations using S and D waves corresponding to various nucleon-nucleon potentials is made. Second, using clear indications that the high-momentum components of n(q) in heavier nuclei are related to those in the deuteron, we develop an approach within the natural orbital representation to calculate n(q) in (A,Z) nuclei on the basis of the deuteron momentum distribution. As examples, n(q) in 4He, 12C, and 56Fe are calculated and good agreement with the y-scaling data is obtained.

  11. Comparative analysis of properties of channels of deuteron and tritium production in 16O p collisions at a projectile momentum of 3.25 GeV/ c per nucleon

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    The results of a comparative analysis of channels involving the inclusive production of deuterons and tritons in 16O p collisions at a projectile momentum of 3.25 GeV/ c per nucleon are presented. The mechanisms governing proton, deuteron, and triton production in the fragmentation of oxygen nuclei are found to be independent. It is shown that the observed proton-multiplicity correlations are associated predominantly with the character of the primary event of a proton-nucleon collision in 16O p interactions. It is found that, in reactions involving triton production, the contributions of processes leading to an increase in the mean proton multiplicity ( n ? p + ? - and np ? pn) and processes leading to its decrease ( p ? n + ? +) compensate each other.

  12. Coherent {pi}{sup 0}-photoproduction on the deuteron including polarization observables

    SciTech Connect

    Darwish, E. M. [Applied Physics Department, Faculty of Applied Science, Taibah University (Saudi Arabia); Physics Department, Faculty of Science, Sohag University, Sohag 82524 (Egypt); Akopov, N. [Yerevan Physics Institute, Br. Alikhanian 2, 0036 Yerevan (Armenia); El-Zohry, M. [Yerevan State University, A. Manoogian 1, 0025 Yerevan (Armenia)

    2011-10-27

    Coherent {pi}{sup 0}-photoproduction on the deuteron including polarization effects in the energy region from {pi}-threshold up to 1 GeV is studied using an enhanced elementary pion photo-production operator on the free nucleon and a realistic NN potential model for the deuteron wave function. Results for double polarization observables are predicted for which the sensitivity to various models for the elementary pion photoproduction amplitude is investigated. We find considerable dependence of the results on the elementary amplitude. In addition, results for differential cross section are predicted and compared with the experimental data from TAPS and a satisfactory agreement was found.

  13. Measurements of the Deuteron Elastic Structure Function A(Q{sup 2}) for 0.7

    SciTech Connect

    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

    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.

  14. Higher-order calculations of electron-deuteron scattering in nuclear effective theory

    E-print Network

    Daniel R. Phillips

    2003-04-14

    Motivated by recent advances in the application of effective field theory techniques to light nuclei we revisit the problem of electron-deuteron scattering in these approaches. By sidestepping problems with the description of electron-nucleon scattering data in effective field theories, we show that the effective theory expansion for deuteron physics converges well over a wide range of momentum transfers. The resultant description of the physics of the two-nucleon system is good up to virtual photon momenta of order 700 MeV.

  15. Semi-inclusive charged-pion electroproduction off protons and deuterons: Cross sections, ratios, and access to the quark-parton model at low energies

    NASA Astrophysics Data System (ADS)

    Asaturyan, R.; Ent, R.; Mkrtchyan, H.; Navasardyan, T.; Tadevosyan, V.; Adams, G. S.; Ahmidouch, A.; Angelescu, T.; Arrington, J.; Asaturyan, A.; Baker, O. K.; Benmouna, N.; Bertoncini, C.; Blok, H. P.; Boeglin, W. U.; Bosted, P. E.; Breuer, H.; Christy, M. E.; Connell, S. H.; Cui, Y.; Dalton, M. M.; Danagoulian, S.; Day, D.; Dunne, J. A.; Dutta, D.; El Khayari, N.; Fenker, H. C.; Frolov, V. V.; Gan, L.; Gaskell, D.; Hafidi, K.; Hinton, W.; Holt, R. J.; Horn, T.; Huber, G. M.; Hungerford, E.; Jiang, X.; Jones, M.; Joo, K.; Kalantarians, N.; Kelly, J. J.; Keppel, C. E.; Kubarovsky, V.; Li, Y.; Liang, Y.; Mack, D.; Malace, S. P.; Markowitz, P.; McGrath, E.; McKee, P.; Meekins, D. G.; Mkrtchyan, A.; Moziak, B.; Niculescu, G.; Niculescu, I.; Opper, A. K.; Ostapenko, T.; Reimer, P. E.; Reinhold, J.; Roche, J.; Rock, S. E.; Schulte, E.; Segbefia, E.; Smith, C.; Smith, G. R.; Stoler, P.; Tang, L.; Ungaro, M.; Uzzle, A.; Vidakovic, S.; Villano, A.; Vulcan, W. F.; Wang, M.; Warren, G.; Wesselmann, F. R.; Wojtsekhowski, B.; Wood, S. A.; Xu, C.; Yuan, L.; Zheng, X.

    2012-01-01

    A large set of cross sections for semi-inclusive electroproduction of charged pions (?±) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared W2>4 GeV2 (up to ?7 GeV2) and range in four-momentum transfer squared 2mechanisms. The x, z, and Pt2 dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for ?+ and ?-) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of d quarks are found to be slightly smaller than for u quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

  16. Bubble breakup from ventilated cavities in multiphase reactors

    Microsoft Academic Search

    G. D. Rigby; G. M. Evans; G. J. Jameson

    1997-01-01

    A study of the small bubbles created by gas dispersion mechanisms at the rear of a ventilated cavity attached to a cylindrical bluff body is presented. A critical Weber number model, which uses a CFD simulation of the continuous-phase flow field to simulate the rate of energy dissipation at the rear of the cavity, is proposed to allow prediction of

  17. Tidal breakup and origin of the Uranian ring system

    Microsoft Academic Search

    P. Farinella; A. Milani; A. M. Nobili; P. Paolicchi

    1984-01-01

    It is shown that a configuration of alternating rings and moonlets could be the natural outcome of an evolutionary history of Uranus starting from a simple initial condition. In the evolution of the system, the ring material was confined in very narrow zones due to the shepherding mechanism. The tidally-evolving shepherding moonlets were captured into stable resonance configurations with the

  18. Break-up Dates of Alpine Lakes As Proxy Data for Local and Regional Mean Surface Air Temperatures

    Microsoft Academic Search

    David M. Livingstone

    1997-01-01

    The calendar date of ice break-up on Lej da San Murezzan, a high-altitude (1768 m a.s.l.) lake in the Swiss Alps, has been recorded uninterruptedly since 1832. Based on this record and on shorter, interrupted records from two neighbouring lakes, the potential use of the timing of spring break-up as a proxy for local and regional surface air temperatures in

  19. Nuclear and Coulomb Interaction in the 8B to 7Be + p Breakup Reaction at sub-Coulomb Energies

    E-print Network

    V. Guimaraes; J. J. Kolata; D. Peterson; P. Santi; R. H. White-Stevens; S. M. Vincent; F. D. Becchetti; M. Y. Lee; T. W. O'Donnell; D. A. Roberts; J. A. Zimmerman

    1999-12-21

    The angular distribution for the breakup of 8B into 7Be+p on a 58Ni target has been measured at an incident energy of 25.75 MeV. The data are inconsistent with first-order theories but are remarkably well described by calculations including higher-order effects. The comparison with theory illustrates the importance of the exotic proton halo structure of 8B in accounting for the observed breakup angular distribution.

  20. Timing of hot spot--related volcanism and the breakup of madagascar and India.

    PubMed

    Storey, M; Mahoney, J J; Saunders, A D; Duncan, R A; Kelley, S P; Coffin, M F

    1995-02-10

    Widespread basalts and rhyolites were erupted in Madagascar during the Late Cretaceous. These are considered to be related to the Marion hot spot and the breakup of Madagascar and Greater India. Seventeen argon-40/argon-39 age determinations reveal that volcanic rocks and dikes from the 1500-kilometer-long rifted eastern margin of Madagascar were emplaced rapidly (mean age = 87.6 +/- 0.6 million years ago) and that the entire duration of Cretaceous volcanism on the island was no more than 6 million years. The evidence suggests that the thick lava pile at Volcan de l'Androy in the south of the island marks the focal point of the Marion hot spot at approximately 88 million years ago and that this mantle plume was instrumental in causing continental breakup. PMID:17813912

  1. Multifractality of drop breakup in the air-blast nozzle atomization process.

    PubMed

    Zhou, W X; Yu, Z H

    2001-01-01

    The multifractal nature of drop breakup in the air-blast nozzle atomization process has been studied. We apply the multiplier method to extract the negative and the positive parts of the f(alpha) curve with the data of drop-size distribution measured using dual particle dynamic analyzer. A random multifractal model with the multiplier triangularly distributed is proposed to characterize the breakup of drops. The agreement of the left part of the multifractal spectra between the experimental result and the model is remarkable. The cause of the distinction of the right part of the f(alpha) curve is argued. The fact that negative dimensions arise in the current system means that the spatial distribution of the drops yielded by the high-speed jet fluctuates from sample to sample. In other words, the spatial concentration distribution of the disperse phase in the spray zone fluctuates momentarily, showing intrinsic randomness. PMID:11304348

  2. Analytical Formula for Weak Multi-Bunch Beam Break-Up in a Linac

    SciTech Connect

    Bane, Karl LF

    2000-07-26

    In designing linac structures for multi-bunch applications the authors are often interested in estimating the effect of relatively weak multi-bunch beam breakup (BBU), due to the somewhat complicated wakefields of detuned structures. This, for example, is the case for the injector linacs of the JLC/NLC linear collider project. Deriving an analytical formula for such a problem is the subject of this report. Note that the more studied multi-bunch BBU problem, i.e. the effect on a bunch train of a single strong mode, the so-called cumulative beam break-up instability, is a somewhat different problem, and one for which the approach presented here is probably not very useful.

  3. The Breakup of a Main-Belt Asteroid 450 Thousand Years Ago

    NASA Astrophysics Data System (ADS)

    Nesvorny, D.; Vokrouhlicky, D.; Bottke, W. F.

    2006-06-01

    Collisions in the asteroid belt frequently lead to catastrophic breakups, where more than half of the target's mass is ejected into space. Several dozen large asteroids have been disrupted by impacts over the past several billion years. These impact events have produced groups of fragments with similar orbits called asteroid families. Here we report the discovery of a very young asteroid family around the object 1270 Datura. Our work takes advantage of a method for identification of recent breakups in the asteroid belt using catalogs of osculating (i.e., instantaneous) asteroid orbits. The very young families show up in these catalogs as clusters in a five-dimensional space of osculating orbital elements.

  4. Influence of substrate confinement on the phase-correlation in the capillary breakup of lithographically patterned polymer stripes

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Ding, Yifu

    2013-03-01

    We study the simultaneous capillary breakup of parallel polymer stripes, which were partially embedded in an immiscible polymer and confined on elastic substrates. Polystyrene (PS) and Poly(methyl methacrylate) (PMMA) were used because of their immiscibility. When annealed at a temperature above the glass transition temperatures of both polymers, capillary instabilities of the stripes were observed. We found that substrate-induced confinement influenced the phase-correlation in the breakup of neighboring stripes. With the increase of substrate confinement, the simultaneous breakup of the parallel polymer stripes transitioned from non-correlated to in-phase, irrespective of the viscosity ratio between PS and PMMA. We study the simultaneous capillary breakup of parallel polymer stripes, which were partially embedded in an immiscible polymer and confined on elastic substrates. Polystyrene (PS) and Poly(methyl methacrylate) (PMMA) were used because of their immiscibility. When annealed at a temperature above the glass transition temperatures of both polymers, capillary instabilities of the stripes were observed. We found that substrate-induced confinement influenced the phase-correlation in the breakup of neighboring stripes. With the increase of substrate confinement, the simultaneous breakup of the parallel polymer stripes transitioned from non-correlated to in-phase, irrespective of the viscosity ratio between PS and PMMA. The authors acknowledge the funding support from the National Science Foundation under Grant No. CMMI-1031785. Acknowledgment is made to the donors of the Petroleum Research Fund for partial support of this research (Grant Number: ACS-PRF 50581-DNI7).

  5. A new method to solve the Nd breakup scattering problem in configuration space

    NASA Astrophysics Data System (ADS)

    Suslov, Vladimir

    2005-11-01

    A new computational method for solving the configuration-space Faddeev equations for three nucleon system has been developed. This method is based on the spline-decomposition in the angular variable and a generalization of the Numerov method for the hyperradius. The s-wave calculations of the inelasticity and phase-shift, as well as breakup amplitudes for nd and pd breakup scattering for lab energies 14.1 and 42.0 MeV were performed with the Malfliet -Tjon MT I-III potential. In the case of nd breakup scattering the results are in good agreement with those of the benchmark solution [1],[2]. In the case of pd quartet breakup scattering disagreement for the inelasticities reaches up to 6% as compared with those of the Pisa group [3]. The calculated pd amplitudes fulfill the optical theorem with a good precision. 1. J. L. Friar, B. F. Gibson, G. Berthold, W. Gloeckle, Th. Cornelius, H. Witala, J. Haidenbauer, Y. Koike, G. L. Payne, J. A. Tjon, and W. M. Kloet,: http://link.aip.org/link/?&lcreator=getabs-normal&ldir=FWD&lrel=CITES&fromkey=PRVCAN000069000004044003000001&fromkeyType=CVIPS&fromloc=AIP&toj=PRVCAN&tov=42&top=1838&toloc=APS&tourl=http%3A%2F%2Flink.aps.org%2Fabstract%2FPRC%2Fv42%2FPhys. Rev. C 42, 1838 (1990). 2. Frair J.L, Payne G.L., Gl"ockle W., Hueber D., Witala H.: Phys. Rev. C 51, 2356 (1995) 3. Kievsky A., Viviani M., and Rosati S.: Phys. Rev. C 64, 024002 (2001)

  6. A pseudo-breakup observation: Localized current wedge across the postmidnight auroral oval

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Amm, O.; Kauristie, K.; Pulkkinen, T. I.; Tanskanen, E.

    2003-01-01

    This study presents a detailed description and analysis of a pseudo-breakup, which took place in the field of view (FOV) of the Magnetometers-Ionospheric Radars-All-sky Cameras Large Experiment (MIRACLE) network (IMAGE magnetometers, Scandinavian Twin Auroral Radar Experiment [STARE] radars, and all-sky cameras) on 3 November 1997 at 2212 UT. The activation lasted ˜10 min, occurred during geomagnetically quiet conditions (Dst ? -10 nT), and was followed by a global-scale substorm about half an hour later (at 2246 UT). Both the pseudo-breakup and the substorm had onsets at times corresponding to the Wind satellite observations of interplanetary magnetic field (IMF) BZ northward turnings as delayed to the subsolar magnetopause. The auroral display of the pseudo-breakup was a mesoscale spiral with a counterclockwise winding direction. Simultaneously, STARE recorded clockwise plasma flow in the spiral surroundings. Applying the method of characteristics to the MIRACLE observations revealed that the spiral was associated with a localized current wedge (less than a few hours in MLT and about 4° in latitude), tilted in the northeast-southwest direction. The maximum upward current density at the western edge of the wedge was about 6 A/km2, which clearly exceeds the threshold of spiral buildup (2.5 A/km2) suggested by earlier theoretical studies. About an hour before the pseudo-breakup, the energy input from the solar wind to the magnetosphere (quantified by the ? parameter) exceeded the substorm threshold and the ionospheric conductivity was high enough to support substorm activity. Two likely reasons for the activation to remain localized were its unfavorable location in the morning side of the Harang discontinuity region and the abrupt decrease of the solar wind energy input at its onset time.

  7. Break-up characteristics of gelled propellant simulants with various gelling agent contents

    Microsoft Academic Search

    Inchul Lee; Jaye Koo

    2010-01-01

    Gel propulsion systems have many advantages with respect to high performance, the energy management of liquid propulsion systems,\\u000a storability, high density impulse, and low leakage of liquid propellants. The atomization process provides sufficient contact\\u000a surface area between the gelled fuel and oxidizer jets. It is important to study how injection characteristics of gelled propellants\\u000a are related with break-up and spray

  8. Influence of the Coulomb Interaction on the Chemical Equilibrium of Nuclear Systems at Break-Up

    E-print Network

    J. Tõke; W. Gawlikowicz; W. U. Schröder

    2000-06-29

    The importance of a Coulomb correction to the formalism proposed by Albergo et al. for determining the temperatures of nuclear systems at break-up and the ensities of free nucleon gases is discussed. While the proposed correction has no effect on the temperatures extracted based on double isotope ratios, it becomes non-negligible when such temperatures or densities of free nucleon gases are extracted based on multiplicities of heavier fragments of different atomic numbers.

  9. Phenomena of pulsation tectonics related to the breakup of the eastern north American continental margin

    Microsoft Academic Search

    Robert E. Sheridan

    1983-01-01

    New data from the recent IPOD drilling at Deep Sea Drilling Project Site 534 in the Blake-Bahama Basin give a defi- nitive age for the spreading-center shift involved in the breakup of the North American Atlantic margin. An age of ba- sal Callovian (~ 155 m.y.) is determined for the Blake Spur magnetic anomaly marking this spreading-center shift that signals

  10. A model to predict the conditions for liquid drop breakup and the resultant mean fragment size

    NASA Technical Reports Server (NTRS)

    Wert, K. L.; Jacobs, H. R.

    1994-01-01

    The potential significance of drop fragmentation in sprays and other propulsion-related multiphase flows has been noted in the literature. This has motivated recent experimental and theoretical works to: better understand the fundamentals of physics of drop breakup processes, and develop models of drop fragmentation suitable for use in multiphase flow codes. The works summarized below aim to contribute to both sides of this two-pronged attack.

  11. Deformation and Break-up of Suspension Droplets Sheared in an Immiscible Fluid

    NASA Astrophysics Data System (ADS)

    Desse, Melinda; Hill, Sandra E.; Mitchell, John R.; Wolf, Bettina; Budtova, Tatiana

    2008-07-01

    The deformation and break-up behaviour of suspension droplets immersed in an immiscible fluid has not been widely studied albeit such systems are frequently encountered in every day multiphase products such as foods and cosmetics. Starch is a common thickener used in the food industry. Starch suspensions have shown to offer better flavour perception than polymer thickened solutions; a better understanding of their behaviour under flow would be beneficial in terms of advancement on product formulation. Deformation and break-up of a droplet of swollen-in-water starch granules placed in high viscosity silicon oil was visualised using a counter-rotating parallel-plate shear cell. The silicon oil had a high viscosity to induce shear stresses high enough to deform the droplet; it is also transparent and inert towards the studied system. The starch suspension was prepared to have a volume fraction of 100% swollen granules, i.e. that all water was bound within the swollen starch granules. The shear flow behaviour of this starch suspension is characterised by an apparent yield stress, shear-thinning and first normal stress differences. The rheo-optical experiments were conducted as start-up flow experiments applying shear stresses above the apparent yield stress. A constant shear stress throughout the experiment allows a constant viscosity of the droplet and therefore rules out the shear thinning aspect. Analysis showed droplet break-up at critical Capillary numbers close to those reported for Newtonian fluids. The results demonstrate that the droplet break-up behaviour in a complex emulsion system submitted to shear flow may not be fully described by the rheology of the individual phases alone but may require a microstructure component.

  12. Breakup of Laminar Jet into Drops in Immiscible Liquid-Liquid Systems with Mass Transfer

    Microsoft Academic Search

    S. Homma; G. Tryggvason; J. Koga; S. Matsumoto

    1998-01-01

    The breakup of an axisymmetric jet into drops in immiscible liquid-liquid systems with mass transfer is investigated numerically. It is assumed that the solute concentration only affects the interfacial tension, so that the density and the viscosity of both phases are not influenced by the mass transfer. The axisymmetric Navier-Stokes equations, with a convection\\/diffusion equation for a single solute are

  13. Low-altitude acceleration of auroral electrons during breakup observed by a mother-daughter rocket

    NASA Technical Reports Server (NTRS)

    Johnstone, A. D.; Davis, T. N.

    1974-01-01

    By the use of a mother-daughter rocket combination and ground-based observations with television, time and space variations are resolved in particle measurements in breakup aurora. The spectral variations measured during a temporal variation in the aurora can be explained by a nearly uniform acceleration of all the electrons such as would be caused by an electric potential drop along the magnetic field lines. Many other explanations can be eliminated.

  14. Appalachian Salients and Recesses: Late Precambrian Continental Breakup and the Opening of the Iapetus Ocean

    Microsoft Academic Search

    Douglas W. Rankin

    1976-01-01

    Appalachian salients (convex toward the craton) and recesses (concave towaid the craton) are inherited from the initial breakup of a continental mass by the intersection of rift valleys radiating from triple junctions, beginning about 820 m.y. ago. The trace of axes of anticlinoria exposing crystalline rocks older than 1 b.y., here called the Blue-Green-Long axis after major Precambrian massifs, roughly

  15. Amalgamation and initial break-up of Gondwana along the East African - Antarctic Orogen

    Microsoft Academic Search

    J. Jacobs; B. Emmel

    2003-01-01

    East- and West-Gondwana, or parts thereof, amalgamated along the East African - Antarctic Orogen at c. 550 Ma. The initial Gondwana break-up roughly followed the length of the orogen and reactivated Pan-African suture and shear zones 350 Ma after amalgamation. In Antarctica, the collision of E- and W-Gondwana overprinted wide continental margins but the location of the principle suture zone(s)

  16. Effects of Insoluble Surfactants on the Nonlinear Deformation and Breakup of Stretching Liquid Bridges.

    NASA Astrophysics Data System (ADS)

    Ambravaneswaran, B.; Basaran, O. A.

    1997-11-01

    During the emission of single drops and the atomization of a liquid from a nozzle, threads of liquid are stretched and broken. A convenient setup for studying in a controlled manner the dynamics of liquid threads is the so-called liquid bridge, which is created by holding captive a volume of liquid between two solid disks and pulling them apart at a constant velocity. Although the stability of static bridges and the dynamics of stretching bridges of pure liquids have been extensively studied, even a rudimentary understanding of the dynamics of the stretching and breakup of bridges of surfactant-laden liquids is lacking. In this work, the dynamics of a bridge of a Newtonian liquid containing an insoluble surfactant are analyzed by solving numerically (i) the complete free boundary problem comprised of the transient Navier-Stokes system that governs fluid flow and the convection-diffusion equation that governs surfactant transport and (ii) a one-dimensional set of equations that results from a slender-jet approximation. The computational techniques for both are based on the method-of-lines, and use finite elements for discretization in space and finite differences for discretization in time. The computational results reveal that the presence of surfactant can drastically alter the physics of bridge breakup compared to the situation in which the bridge is surfactant free and also make clear how the bridge length at breakup varies with stretching velocity, bridge geometry, and bulk and surface properties of the liquid bridge.

  17. A Southern Hemisphere origin for campanulid angiosperms, with traces of the break-up of Gondwana

    PubMed Central

    2013-01-01

    Background New powerful biogeographic methods have focused attention on long-standing hypotheses regarding the influence of the break-up of Gondwana on the biogeography of Southern Hemisphere plant groups. Studies to date have often concluded that these groups are too young to have been influenced by these ancient continental movements. Here we examine a much larger and older angiosperm clade, the Campanulidae, and infer its biogeographic history by combining Bayesian divergence time information with a likelihood-based biogeographic model focused on the Gondwanan landmasses. Results Our analyses imply that campanulids likely originated in the middle Albian (~105 Ma), and that a substantial portion of the early evolutionary history of campanulids took place in the Southern Hemisphere, despite their greater species richness in the Northern Hemisphere today. We also discovered several disjunctions that show biogeographic and temporal correspondence with the break-up of Gondwana. Conclusions While it is possible to discern traces of the break-up of Gondwana in clades that are old enough, it will generally be difficult to be confident in continental movement as the prime cause of geographic disjunctions. This follows from the need for the geographic disjunction, the inferred biogeographic scenario, and the dating of the lineage splitting events to be consistent with the causal hypothesis. PMID:23565668

  18. DebriSat: The New Hypervelocity Impact Test for Satellite Breakup Fragment Characterization

    NASA Technical Reports Server (NTRS)

    Cowardin, Heather

    2015-01-01

    To replicate a hyper-velocity fragmentation event using modern-day spacecraft materials and construction techniques to better improve the existing DoD and NASA breakup models: DebriSat is intended to be representative of modern LEO satellites. Major design decisions were reviewed and approved by Aerospace subject matter experts from different disciplines. DebriSat includes 7 major subsystems. Attitude determination and control system (ADCS), command and data handling (C&DH), electrical power system (EPS), payload, propulsion, telemetry tracking and command (TT&C), and thermal management. To reduce cost, most components are emulated based on existing design of flight hardware and fabricated with the same materials. center dotA key laboratory-based test, Satellite Orbital debris Characterization Impact Test (SOCIT), supporting the development of the DoD and NASA satellite breakup models was conducted at AEDC in 1992. Breakup models based on SOCIT have supported many applications and matched on-orbit events reasonably well over the years.

  19. Discovery Of Main-belt Asteroid Breakups Occurring Within The Last 1 My

    NASA Astrophysics Data System (ADS)

    Vokrouhlicky, David; Nesvorny, D.; Bottke, W. F.

    2006-09-01

    Here we report the discovery of four new and very recent asteroid breakups in the main belt, all which occurred within the last My. To identify these asteroid mini-families, we looked for similarities in their osculating orbital elements (except mean anomaly). We selected 264,403 asteroids from the Lowell Observatory catalog that have observational arcs longer than 10 days, and we used the hierarchical clustering method (HCM) to search for groups. Backward integration of the clustered orbits allowed us to determine the age of each breakup event. The youngest of the 4 was 70 kya, while the oldest was 600 kya. These new asteroid mini-families are important because they have not yet experienced significant orbital evolution from Yarkovsky thermal forces nor meaningful spectroscopic changes from space weathering processes. Accordingly, they provide us with natural laboratories to better understand impact physics, asteroid composition, and surface-aging processes. Moreover, dust produced by these events may be a source of some of the material in the circumstellar (zodiacal) dust cloud as well as specific infrared features observed with the IRAS and Spitzer spacecrafts. The timescales for small dust particles produced by these breakup events to reach Earth by Poynting-Roberson drag is short enough that some should have already landed on Earth; this raises the possibility of identifying it within well-dated ice core samples. Thus, finding this material could be considered one way to have a very low-cost asteroid sample return mission.

  20. Depth-dependent extension, two-stage breakup and depleted lithospheric counterflow at rifted margins

    NASA Astrophysics Data System (ADS)

    Huismans, Ritske S.; Beaumont, Christopher

    2014-05-01

    Uniform lithospheric extension predicts basic properties of non-volcanic rifted margins but fails to explain other important characteristics. Significant discrepancies are observed at 'type I' margins (such as the Iberia-Newfoundland conjugates), where large tracts of continental mantle lithosphere are exposed at the sea floor, and 'type II' margins (such as some ultrawide central South Atlantic margins), where thin continental crust spans wide regions below which continental lower crust and mantle lithosphere have apparently been removed. Neither corresponds to uniform extension. Instead, either crust or mantle lithosphere has been preferentially removed. Using dynamical models, we demonstrate that these margins are opposite end members: in type I, depth-dependent extension results in crustal-necking breakup before mantle-lithosphere breakup and in type II, the converse is true. These two-layer, two-stage breakup behaviours explain the discrepancies and have implications for the styles of the associated sedimentary basins. Laterally flowing lower-mantle lithosphere may underplate both type I and type II margins, thereby contributing to their anomalous characteristics.

  1. The breakup of digital microfluids on a piezoelectric substrate using surface acoustic waves.

    PubMed

    Zhang, An-Liang; Zha, Yan

    2014-12-01

    A new method for the breakup of a digital microfluid (a discrete droplet) is presented and a device for splitting the digital microfluid is fabricated on a 128° yx-LiNbO3 piezoelectric substrate using microelectronic technology. Together with the surface tension of the digital microfluid, the inertia of acoustic streaming caused by the sudden disappearance of the electric signal for generating the surface acoustic wave breaks up the digital microfluid. The escape angle of the daughter digital microfluids is calculated. A sound-absorption film is coated on the acoustic path to prevent the further breakup of the daughter digital microfluids. Droplet breakups are demonstrated using red dye solution digital microfluids. Results show that digital microfluids can be broken up by suddenly decreasing the power of the electrical signal from 12.3 dBm to -3.98 dBm, and the average escape angle of daughter digital microfluids is 68.5° for 4 ?L of initial digital microfluid. The results also show that the escape angle is affected by the initial volume of the digital microfluid. PMID:25474784

  2. A user`s guide for BREAKUP: A computer code for parallelizing the overset grid approach

    SciTech Connect

    Barnette, D.W.

    1998-04-01

    In this user`s guide, details for running BREAKUP are discussed. BREAKUP allows the widely used overset grid method to be run in a parallel computer environment to achieve faster run times for computational field simulations over complex geometries. The overset grid method permits complex geometries to be divided into separate components. Each component is then gridded independently. The grids are computationally rejoined in a solver via interpolation coefficients used for grid-to-grid communications of boundary data. Overset grids have been in widespread use for many years on serial computers, and several well-known Navier-Stokes flow solvers have been extensively developed and validated to support their use. One drawback of serial overset grid methods has been the extensive compute time required to update flow solutions one grid at a time. Parallelizing the overset grid method overcomes this limitation by updating each grid or subgrid simultaneously. BREAKUP prepares overset grids for parallel processing by subdividing each overset grid into statically load-balanced subgrids. Two-dimensional examples with sample solutions, and three-dimensional examples, are presented.

  3. Effective field theory calculation of two-deuteron radiative capture reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Sadeghi, H.; Khalili, H.

    2014-08-01

    Two-deuteron radiative capture reaction is one of the deuterium-burning processes that the cross section is not well known at very low-energies. We develop the formalism based on pionless Effective Field Theory (EFT) for deuteron-deuteron ( dd) scattering to derive the cross section of two-deuteron radiative capture. Within this formalism the two- and three-body forces, should also be included in the capture cross section calculations. The aim of the present work is to calculate the observables of the low-energy dd photonuclear reactions. The cross section and the astrophysical S-factor for the 2H( d, ?)4He reaction have been calculated. The 4He is studied as four-body bound states in the pionless EFT. The theoretical uncertainties for observables are estimated based on the variation of the cutoffs. The astrophysical S-factor is accurately determined to be 6.9×10-6 keV b (6.1×10-6 keV b) for two-body (two- and three-body) at zero energy. A satisfactory agreement between theory and experiment for dd radiative capture observables up to order of calculation has been found by insertion of three-body force.

  4. Spin Physics Experiments at NICA-SPD with polarized proton and deuteron beams

    NASA Astrophysics Data System (ADS)

    Savin, I.; Efremov, A.; Peshekhonov, D.; Kovalenko, A.; Teryaev, O.; Shevchenko, O.; Nagajcev, A.; Guskov, A.; Kukhtin, V.; Toplilin, N.

    2015-01-01

    The brief description of the Letter of Intent proposing primarily to perform measurements of asymmetries of the DY pair production in collisions of non-polarized, longitudinally and transversally polarized protons and deuterons which provide an access to all leading twist collinear and TMD PDFs of quarks and anti-quarks in nucleons.

  5. Measurement of tensor analyzing powers in elastic electron deuteron scattering with BLAST

    E-print Network

    Zhang, Chi, Ph. D. Massachusetts Institute of Technology

    2006-01-01

    This work reports a precision measurement of deuteron tensor analyzing powers T20 and T21 at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range of 2:15 to 4:5 fm¡1 ...

  6. Nucleon Polarizabilities from Deuteron Compton Scattering within a Green's-Function Hybrid Approach

    E-print Network

    Robert P. Hildebrandt; Harald W. Griesshammer; Thomas R. Hemmert

    2010-08-09

    We examine elastic Compton scattering from the deuteron for photon energies ranging from zero to 100 MeV, using state-of-the-art deuteron wave functions and NN-potentials. Nucleon-nucleon rescattering between emission and absorption of the two photons is treated by Green's functions in order to ensure gauge invariance and the correct Thomson limit. With this Green's-function hybrid approach, we fulfill the low-energy theorem of deuteron Compton scattering and there is no significant dependence on the deuteron wave function used. Concerning the nucleon structure, we use Chiral Effective Field Theory with explicit \\Delta(1232) degrees of freedom within the Small Scale Expansion up to leading-one-loop order. Agreement with available data is good at all energies. Our 2-parameter fit to all elastic $\\gamma d$ data leads to values for the static isoscalar dipole polarizabilities which are in excellent agreement with the isoscalar Baldin sum rule. Taking this value as additional input, we find \\alpha_E^s= (11.3+-0.7(stat)+-0.6(Baldin)) x 10^{-4} fm^3 and \\beta_M^s = (3.2-+0.7(stat)+-0.6(Baldin)) x 10^{-4} fm^3 and conclude by comparison to the proton numbers that neutron and proton polarizabilities are essentially the same.

  7. MEASUREMENTS OF THE DEUTERON ELECTRIC AND MAGNETIC FORM FACTORS AT THE JEFFERSON LABORATORY

    E-print Network

    MEASUREMENTS OF THE DEUTERON ELECTRIC AND MAGNETIC FORM FACTORS AT THE JEFFERSON LABORATORY range of the previous AQ2 SLAC data 2 . The range in the squared four-momentum transfer, Q2, is 0 THE JEFFERSON LAB HALL-A COLLABORATION: Blaise Pascal, Cal. State LA, Duke, Florida International, Florida State

  8. Measurement of the deuteron electric and magnetic form factors at Jefferson Lab

    Microsoft Academic Search

    Gerassimos G. Petratos

    1998-01-01

    The results from an experiment to measure the electric, A(Q²), and magnetic, B(Q²), form factors of the deuteron at large momentum transfers at the Jefferson Laboratory (JLAB) will be reported. The experiment performed elastic electron scattering from deuterium in coincidence; it has improved the quality of the existing data in the range of overlap and has significantly extended the Q²

  9. Proton and deuteron F[subscript 2] structure function at low Q[superscript 2

    E-print Network

    Tvaskis, V.

    Measurements of the proton and deuteron F2 structure functions are presented. The data, taken at Jefferson Lab Hall C, span the four-momentum transfer range 0.06

  10. Extracting hadron-neutron scattering amplitudes from hadron-proton and hadron-deuteron measurements

    NASA Technical Reports Server (NTRS)

    Franco, V.

    1977-01-01

    A method is presented for extracting hadron-neutron scattering amplitudes from hadron-proton and hadron-deuteron measurements within the framework of the Glauber approximation. This method, which involves the solution of a linear integral equation, is applied to pn collisions between 15 and 275 GeV/c. Effects arising from inelastic intermediate states are estimated.

  11. Effects of primary breakup modeling on spray and combustion characteristics of compression ignition engines

    SciTech Connect

    Som, S.; Aggarwal, S.K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States)

    2010-06-15

    Injector flow dynamics and primary breakup processes are known to play a pivotal role in determining combustion and emissions in diesel engines. In the present study, we examine the effects of primary breakup modeling on the spray and combustion characteristics under diesel engine conditions. The commonly used KH model, which considers the aerodynamically induced breakup based on the Kelvin-Helmholtz instability, is modified to include the effects of cavitation and turbulence generated inside the injector. The KH model and the new (KH-ACT) model are extensively evaluated by performing 3-D time-dependent simulations with detailed chemistry under diesel engine conditions. Results indicate that the inclusion of cavitation and turbulence enhances primary breakup, leading to smaller droplet sizes, decrease in liquid penetration, and increase in the radial dispersion of spray. Predictions are compared with measurements for non-evaporating and evaporating sprays, as well as with flame measurements. While both the models are able to reproduce the experimentally observed global spray and combustion characteristics, predictions using the KH-ACT model exhibit closer agreement with measurements in terms of liquid penetration, cone angle, spray axial velocity, and liquid mass distribution for non-evaporating sprays. Similarly, the KH-ACT model leads to better agreement with respect to the liquid length and vapor penetration distance for evaporating sprays, and with respect to the flame lift-off location for combusting sprays. The improved agreement is attributed to the ability of the new model to account for the effects of turbulence and cavitation generated inside the injector, which enhance the primary breakup. Results further indicate that the combustion under diesel engine conditions is characterized by a double-flame structure with a rich premixed reaction zone near the flame stabilization region and a non-premixed reaction zone further downstream. This flame structure is consistent with the Dec's model for diesel engine combustion (Dec, 1997), and well captured by a newly developed flame index based on the scalar product of CO and O{sub 2} mass fraction gradients. (author)

  12. Force Required to Breakup a Continent: Implications on Rifting Localization and Migration

    NASA Astrophysics Data System (ADS)

    Svartman Dias, A. E.; Lavier, L. L.; Hayman, N. W.

    2014-12-01

    The maximum force from ridge push available is about 5 TN/m, lower than that required by 2D and 3D numerical experiments to rift the lithosphere in the absence of magmatic input. We carry out 2D numerical experiments without any magmatic input to study the extensional force necessary to start a rift basin and to breakup a continent. We assume a range of initial temperature structure, crust and mantle initial thicknesses and composition. In a first step, we use velocity boundary conditions (1cm/yr) and we monitor the force necessary to breakup the continent. Results can be classified in two groups according to the amount of force needed to rift through time: (1) The initial force builds up rapidly to 12-20 TN/m within 0.4-1.0 Myr. This is followed by an exponential decrease due to early strain localization and lithospheric weakening. The force is < 5TN/m after 4.4-7.0 Myr of extension. Continental breakup occurs approximately 10 Myr after the onset of extension forming narrow conjugate margins. This group encompasses experiments with initial Tmoho < 650oC and crustal thicknesses ? 35 km, where crust and mantle deformation are coupled from the early stages of rifting. (2) The initial build-up is more discrete, from < 3 TN/m to 4-6.5 TN/m in the first 0.1 Myr, followed by a decrease to a nearly constant value of 3-5 TN/m from 0.4 Myr to 10 Myr, when strain starts localizing. The constant force through time reflects lithosphere strengthening and migration of the deformation. This rift migration forms a wide basin (> 250 km wide) that may evolve to form very asymmetric conjugate margins. Breakup occurs 18 Myr after the onset of rifting or later. This second group corresponds to experiments with initial Tmoho > 650 km and crustal thicknesses ? 35 km. High bending stresses result in upper crust brittle failure and on enhancement of lower crust lateral flow. Interaction between ductile failure in the lower crust and brittle failure in the upper crust controls the migration of the deformation. In a second step, we repeat the same experiments applying a constant extensional force ? 5 TN/m to test whether and how the limited ridge push force naturally available can rift and breakup a continent. We then compare our results to the evolution of aborted rifts and to along strike variations in rifted magins such as the South Atlantic.

  13. Dynamic Sublimation Pressure and the Catastrophic Breakup of Comet ISON

    E-print Network

    Steckloff, Jordan K; Bowling, Timothy; Melosh, H Jay; Minton, David; Lisse, Carey M; Battams, Karl

    2015-01-01

    Previously proposed mechanisms have difficulty explaining the disruption of Comet C/2012 S1 (ISON) as it approached the Sun. We describe a novel cometary disruption mechanism whereby comet nuclei fragment and disperse through dynamic sublimation pressure, which induces differential stresses within the interior of the nucleus. When these differential stresses exceed its material strength, the nucleus breaks into fragments. We model the sublimation process thermodynamically and propose that it is responsible for the disruption of Comet ISON. We estimate the bulk unconfined crushing strength of Comet ISON's nucleus and the resulting fragments to be 0.5 Pa and 1-9 Pa respectively, assuming typical Jupiter Family Comet (JFC) albedos. However, if Comet ISON has an albedo similar to Pluto, this strength estimate drops to 0.2 Pa for the intact nucleus and 0.6-4 Pa for its fragments. Regardless of assumed albedo, these are similar to previous strength estimates of JFCs. This suggests that, if Comet ISON is representat...

  14. Energy dependence of deuteron induced nuclear reaction cross sections on Li, Be, B, C, N, O, and F

    NASA Astrophysics Data System (ADS)

    Parenti, Mathew

    Nuclear reactions induced by 1.2 MeV deuteron on 9Be and 19F are studied with the goal of developing a practical analysis method for these light elements. In addition, the energy dependence of deuteron induced nuclear reactions on 7Li, 9Be, 11B, 12C, 14N, 16O, and 19F was measured. The energy dependence of these nuclear reactions allows the nuclear reaction analysis for these light elements to be corrected for the energy loss of the incident deuteron ions in the analyzed film.

  15. Source size scaling of fragment production in projectile breakup

    SciTech Connect

    Beaulieu, L.; Bowman, D.R.; Fox, D.; Das Gupta, S.; Pan, J.; Ball, G.C.; Djerroud, B.; Dore, D.; Galindo-Uribarri, A.; Guinet, D.; Hagberg, E.; Horn, D.; Laforest, R.; Larochelle, Y.; Lautesse, P.; Samri, M.; Roy, R.; St-Pierre, C. [Laboratoire de Physique Nucleaire, Departement de Physique, Universite Laval, Sainte-Foy, Quebec, G1K 7P4 (CANADA)] [Laboratoire de Physique Nucleaire, Departement de Physique, Universite Laval, Sainte-Foy, Quebec, G1K 7P4 (CANADA); [AECL, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (CANADA); [Institut de Physique Nucleaire de Lyon, 46 Bd du 11 Novembre 1918, F-69622, Villeurbanne Cedex (France); [Department of Physics, McGill University, 3600 University St., Montreal, Quebec, H3A 2T8 (CANADA)

    1996-09-01

    Fragment production has been studied as a function of the source mass and excitation energy in peripheral collisions of {sup 35}Cl+{sup 197}Au at 43 MeV/nucleon and {sup 70}Ge+{sup nat}Ti at 35 MeV/nucleon. The results are compared to the Au+Au data at 600 MeV/nucleon obtained by the ALADIN Collaboration. A mass scaling, by {ital A}{sub source}{approximately} 35 to 190, strongly correlated to excitation energy per nucleon, is presented, suggesting a thermal fragment production mechanism. Comparisons to a standard sequential decay model and the lattice-gas model are made. Fragment emission from a hot, rotating source is unable to reproduce the experimental source size scaling. {copyright} {ital 1996 The American Physical Society.}

  16. Source size scaling of fragment production in projectile breakup

    E-print Network

    L. Beaulieu; D. R. Bowman; D. Fox; S. Das Gupta; J. Pan; G. C. Ball; B. Djerroud; D. Dore; A. Galindo-Uribarri; D. Guinet; E. Hagberg; D. Horn; R. Laforest; Y. Larochelle; P. Lautesse; M. Samri; R. Roy; C. St-Pierre

    1996-07-15

    Fragment production has been studied as a function of the source mass and excitation energy in peripheral collisions of $^{35}$Cl+$^{197}$Au at 43 MeV/nucleon and $^{70}$Ge+$^{nat}$Ti at 35 MeV/nucleon. The results are compared to the Au+Au data at 600 MeV/nucleon obtained by the ALADIN collaboration. A mass scaling, by $A_{source} \\sim$ 35 to 190, strongly correlated to excitation energy per nucleon, is presented, suggesting a thermal fragment production mechanism. Comparisons to a standard sequential decay model and the lattice-gas model are made. Fragment emission from a hot, rotating source is unable to reproduce the experimental source size scaling.

  17. Dynamics and breakup of a contracting liquid filament

    NASA Astrophysics Data System (ADS)

    Notz, Patrick K.; Basaran, Osman A.

    2004-08-01

    Contraction of a filament of an incompressible Newtonian liquid in a passive ambient fluid is studied computationally to provide insights into the dynamics of satellite drops created during drop formation. This free boundary problem, which is composed of the Navier Stokes system and the associated initial and boundary conditions that govern the evolution in time of the filament shape and the velocity and pressure fields within it, is solved by the method of lines incorporating the finite element method for spatial discretization. The finite element algorithm developed here utilizes an adaptive elliptic mesh generation technique that is capable of tracking the dynamics of the filament up to the incipience of pinch-off without the use of remeshing. The correctness of the algorithm is verified by demonstrating that its predictions accord with (a) previously published results of Basaran (1992) on the analysis of finite-amplitude oscillations of viscous drops, (b) simulations of the dynamics of contracting filaments carried out with the well-benchmarked algorithm of Wilkes et al. (1999), and (c) scaling laws governing interface rupture and transitions that can occur from one scaling law to another as pinch-off is approached. In dimensionless form, just two parameters govern the problem: the dimensionless half-length L_o and the Ohnesorge number Oh which measures the relative importance of viscous force to capillary force. Regions of the parameter space are identified where filaments (a) contract to a sphere without breaking into multiple droplets, (b) break via the so-called endpinching mechanism where daughter drops pinch-off from the ends of the main filament, and (c) break after undergoing a series of complex oscillations. Predictions made with the new algorithm are also compared to those made with a model based on the slender-jet approximation. A region of the parameter space is found where the slender-jet approximation fares poorly, and its cause is elucidated by examination of the vorticity dynamics and flow fields within contracting filaments.

  18. Deuteron frozen-spin- polarized target for nd experiments at the VdG accelerator of Charles University

    NASA Astrophysics Data System (ADS)

    Borisov, N. S.; Bazhanov, N. A.; Belyaev, A. A.; Brož, J.; ?erný, J.; Doležal, Z.; Fedorov, A. N.; Gurevich, G. M.; Ivanov, M. P.; Kodyš, P.; Kubík, P.; Kuzmin, E. S.; Lazarev, A. B.; Lehar, F.; Lukhanin, O. O.; Matafonov, V. N.; Neganov, A. B.; Pisarev, I. L.; Švejda, J.; Shilov, S. N.; Usov, Yu. A.; Wilhelm, I.

    2008-08-01

    A frozen-spin- polarized deuteron target cooled by the 3He/ 4He dilution refrigerator is described. Fully deuterated 1,2-propanediol was used as a target material. Deuteron vector polarization about 40% was obtained for the target in the shape of a cylinder of 2-cm diameter and 6-cm length. The target is intended for a study of 3N interactions at the polarized neutron beam generated by the Van de Graaff accelerator at the Charles University in Prague.

  19. Deuteron frozen spin polarized target for nd experiements at the VdG accelerator of Charles University

    E-print Network

    N. S. Borisov; N. A. Bazhanov; A. A. Belyaev; J. Broz; J. Cerny; Z. Dolezal; A. N. Fedorov; G. M. Gurevich; M. P. Ivanov; P. Kodys; P. Kubik; E. S. Kuzmin; A. B. Lazarev; F. Lehar; O. O. Lukhanin; V. N. Matafonov; A. B. Neganov; I. L. Pisarev; J. Svejda; S. N. Shilov; Yu. A. Usov; I. Wilhelm

    2007-12-09

    A frozen spin polarized deuteron target cooled by the 3He/4He dilution refrigerator is described. Fully deuterated 1,2-propanediol was used as a target material. Deuteron vector polarization about 40% was obtained for the target in the shape of a cylinder of 2 cm diameter and 6 cm length. The target is intended for a study of 3N interactions at the polarized neutron beam generated by the Van de Graaff accelerator at the Charles University in Prague.

  20. Contribution of meson-exchange currents to the electromagnetic structure of the deuteron at high momentum transfers

    SciTech Connect

    Krutov, A. F., E-mail: krutov@ssu.samara.r [Samara State University (Russian Federation); Troitsky, V. E., E-mail: troitsky@theory.sinp.msu.s [Moscow State University, Institute of Nuclear Physics (Russian Federation); Tsirova, N. A., E-mail: ntsirova@ssu.samara.r [Samara State University (Russian Federation)

    2009-01-15

    The leading term of the asymptotic expansion of the contributions of the {pi}NN and {rho}{pi}{gamma} processes to the electromagnetic form factors of the deuteron at high momentum transfers is calculated. The resulting asymptotic behavior is compared with experimental data obtained at the Thomas Jefferson Laboratory. Constraints on the functional dependence of meson-nucleon vertex functions that ensure a correct asymptotic behavior of deuteron form factors are discussed.

  1. Theoretical and empirical analysis of the average cross-sectional areas of breakup fragments

    NASA Astrophysics Data System (ADS)

    Hanada, T.; Liou, J.-C.

    2011-05-01

    This paper compares two different approaches to calculate the average cross-sectional area of breakup fragments. The first one is described in the NASA standard breakup model 1998 revision. This approach visually classifies fragments into several shapes, and then applies formulae developed for each shape to calculate the average cross-sectional area. The second approach was developed jointly by the Kyushu University and the NASA Orbital Debris Program Office. This new approach automatically classifies fragments into plate- or irregular-shapes based on their aspect ratio and thickness, and then applies formulae developed for each shape to calculate the average cross-sectional area. The comparison between the two approaches is demonstrated in the area-to-mass ratio ( A/m) distribution of fragments from two microsatellite impact experiments completed in early 2008. A major difference between the two approaches comes from the calculation of the average cross-sectional area of plates. In order to determine which of the two approaches provides a better description of the actual A/m distribution of breakup fragments, a theoretical analysis in the calculation of the average cross-sectional area of an ideal plate is conducted. This paper also investigates the average cross-sectional area of multi-layer insulation fragments. The average cross-sectional area of 214 multi-layer insulation fragments was measured by a planimeter, and then the data were used to benchmark the average cross-sectional areas estimated by the two approaches. The uncertainty in the calculation of the average cross-sectional area with the two approaches is also discussed in terms of size and thickness.

  2. Constraining Lithosphere Deformation Modes during Continental Breakup for the Iberia-Newfoundland Conjugate Margins

    NASA Astrophysics Data System (ADS)

    Jeanniot, L.; Kusznir, N. J.; Mohn, G.; Manatschal, G.

    2014-12-01

    How the lithosphere and asthenosphere deforms during continental rifting leading to breakup and sea-floor spreading initiation is poorly understood. Observations at present-day and fossil analogue rifted margins show a complex OCT architecture which cannot be explained by a single simplistic lithosphere deformation modes. This OCT complexity includes hyper-extended continental crust and lithosphere, detachments faults, exhumed mantle, continental slivers and scattered embryonic oceanic crust. We use a coupled kinematic-dynamic model of lithosphere and asthenosphere deformation to determine the sequence of lithosphere deformation modes leading to continental breakup for Iberia-Newfoundland conjugate margin profiles. We quantitatively calibrate the models using observed present-day water loaded subsidence and crustal thickness, together with subsidence history and the age of melt generation. Flow fields, representing a sequence of lithosphere deformation modes, are generated by a 2D finite element viscous flow model (FE-Margin), and used to advect lithosphere and asthenosphere temperature and material. FE-Margin is kinematically driven by divergent deformation in the upper 15-20 km of the lithosphere inducing passive upwelling below. Buoyancy enhanced upwelling (Braun et al. 2000) is also kinematically included. Melt generation by decompressional melting is predicted using the methodology of Katz et al., 2003. The extension magnitudes used in the lithosphere deformation models are taken from Sutra et al (2013). The best fit calibrated models of lithosphere deformation evolution for the Iberia-Newfoundland conjugate margins require (i) an initial broad region of lithosphere deformation and passive upwelling, (ii) lateral migration of deformation, (iii) an increase in extension rate with time, (iv) focussing of deformation and (v) buoyancy induced upwelling. The preferred calibrated models predict faster extension rates and earlier continental crustal rupture and mantle exhumation for the Iberia Abyssal Plain - Flemish Pass conjugate margin profile than for the Galicia Bank - Flemish Cap profile. The predicted N-S differences in deformation mode evolution give insights into the 3D evolution of Iberia-Newfound margin breakup.

  3. A GEOCLIM simulation of climatic and biogeochemical consequences of Pangea breakup

    NASA Astrophysics Data System (ADS)

    Donnadieu, Y.; GoddéRis, Y.; Pierrehumbert, R.; Dromart, G.; Fluteau, F.; Jacob, R.

    2006-11-01

    Large fluctuations in continental configuration occur throughout the Mesozoic. While it has long been recognized that paleogeography may potentially influence atmospheric CO2 via the continental silicate weathering feedback, no numerical simulations have been done, because of the lack of a spatially resolved climate-carbon model. GEOCLIM, a coupled numerical model of the climate and global biogeochemical cycles, is used to investigate the consequences of the Pangea breakup. The climate module of the GEOCLIM model is the FOAM atmospheric general circulation model, allowing the calculation of the consumption of atmospheric CO2 through continental silicate weathering with a spatial resolution of 7.5°long × 4.5°lat. Seven time slices have been simulated. We show that the breakup of the Pangea supercontinent triggers an increase in continental runoff, resulting in enhanced atmospheric CO2 consumption through silicate weathering. As a result, atmospheric CO2 falls from values above 3000 ppmv during the Triassic down to rather low levels during the Cretaceous (around 400 ppmv), resulting in a decrease in global mean annual continental temperatures from about 20°C to 10°C. Silicate weathering feedback and paleogeography both act to force the Earth system toward a dry and hot world reaching its optimum over the last 260 Myr during the Middle-Late Triassic. In the super continent case, given the persistent aridity, the model generates high CO2 values to produce very warm continental temperatures. Conversely, in the fragmented case, the runoff becomes the most important contributor to the silicate weathering rate, hence producing a CO2 drawdown and a fall in continental temperatures. Finally, another unexpected outcome is the pronounced fluctuation in carbonate accumulation simulated by the model in response to the Pangea breakup. These fluctuations are driven by changes in continental carbonate weathering flux. Accounting for the fluctuations in area available for carbonate platforms, the simulated ratio of carbonate deposition between neritic and deep sea environments is in better agreement with available data.

  4. Breakup Effect of Weakly Bound Projectile on the Barrier Distribution Around Coulomb Barrier

    NASA Astrophysics Data System (ADS)

    Jia, Huiming; Lin, Chengjian; Zhang, Huanqiao; Liu, Zuhua; Yu, Ning; Yang, Feng; Xu, Xinxing; Jia, Fei; Wu, Zhendong; Zhang, Shitao

    2012-05-01

    The excitation function of quasi-elastic (QEL) scattering at a backward angle has been measured for 9Be+208Pb. The barrier distribution was extracted by means of the first derivative of the measured excitation function and calculated with the coupled-channel model. The present work shows that the experimental barrier distribution extracted from QEL scattering is shifted to the low energy side by 1.5 MeV as compared with the theoretical one. This energy discrepancy indicates that breakup is important in the colliding processes of the weakly bound nucleus system.

  5. Dynamics of breakup of multiple vortices in Gross-Pitaevskii equations of superfluids

    NASA Astrophysics Data System (ADS)

    Jonsson, B. L. G.; Ovchinnikov, Yu. N.; Sigal, I. M.; Ting, F. S. T.

    2011-09-01

    In this paper we study the Gross-Pitaevskii equation of the theory of superfluidity, i.e., the nonlinear Schrödinger equation of the Ginzburg-Landau type. We investigate the dynamics of the breakup of the double vortex. More specifically, we prove instability of the double vortex, compute the complex eigenvalue responsible for this instability, and derive the dynamical equation of motion of (centers of) single vortices resulting from splitting of the double vortex. We expect that our analysis can be extended to vortices of higher degree and to magnetic and Chern-Simmons vortices.

  6. Hydrological Measurements in Several Streams During Breakup in the National Petroleum Reserve - Alaska

    NASA Astrophysics Data System (ADS)

    Vas, D. A.; Toniolo, H. A.; Kemnitz, R.; Brailey, D.; Lamb, E. K.

    2011-12-01

    The National Petroleum Reserve - Alaska (NPR - A) expands from the North side of the Brooks Range to the Arctic Ocean over 23.5 million acres. There is a renewed interest in opening NPR -A for oil and gas exploration and hydrological data is critical to the development of pipelines, roads, and bridges. A set of hydraulic measurements, which includes discharge measurements using Acoustic Doppler Current Profiler (ADCP), water slope, and suspended sediment sampling during breakup were conducted on Otuk Creek, Seabee Creek, Prince Creek, Ikpikpuk River, Judy Creek, Fish Creek, and Ublutuoch River in the NPR - A region. We will present preliminary results, grouped by stream characteristics.

  7. Wake Capture, Particle Breakup, and Other Artifacts Associated with Counterflow Virtual Impaction

    SciTech Connect

    Pekour, Mikhail S.; Cziczo, Daniel J.

    2011-03-03

    Counterflow virtual impaction is used to inertially separate cloud elements from un-activated aerosol. Previous airborne, ground-based and laboratory studies using this technique exhibit artifacts that are not fully explained by impaction theory. We have performed laboratory studies that show small particles can be carried across the inertial barrier of the counterflow by collision and/or coalescence or riding the wake of larger particles with sufficient inertia. We have also performed theoretical calculations to show that aerodynamic forces associated with the requisite acceleration and deceleration of particles within a counterflow virtual impactor can lead to breakup. The implication of these processes on studies using this technique are discussed.

  8. Comparison of axial and radial electron beam-breakup transit-time oscillators

    SciTech Connect

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

    1995-08-01

    Comparison of two configurations of a novel high-power microwave generator is presented in this article. Coupling the beam-breakup instability with the transit-time effect of the electron beam in the cavity, rapid energy exchange between the electrons and cavity modes can occur. The dominant cavity modes in the axial and radial configurations are different but their growth rates are comparable. We found that the radial configuration can have a beam impedance less than 10 {Omega} and therefore more suitable for low-voltage and high power operation. Good agreements have been obtained between linear theory and simulation for both configurations.

  9. Theory of (d,p) and (p,d) reactions including breakup: Comparison of methods

    NASA Astrophysics Data System (ADS)

    Moro, A. M.; Nunes, F. M.; Johnson, R. C.

    2009-12-01

    There is an increasing interest in studying transfer reactions to probe the nuclear structure of exotic nuclei. For these loosely bound systems, the role of the continuum needs to be well understood. In this study, we concentrate on (p,d) and (d,p) reactions and compare two formulations for the transfer process that take into account breakup states. Applications to Be11(p,d)Be10 at Elab=38.4 MeV/nucleon and Be10(d,p)Be11 at Elab=12.5 MeV/nucleon are presented, as is a detailed discussion of convergence rates.

  10. Quasifree expansion picture of break-up events: An analysis of ionizing systems

    SciTech Connect

    Errea, L.F.; Mendez, L.; Pons, B.; Riera, A.; Sevila, I. [Laboratorio de Fisica Atomica Molecular en Plasmas de Fusion Nuclear, asociado al CIEMAT, Departamento de Quimica C-IX, Universidad Autonoma de Madrid, 28049 Madrid (Spain)

    2003-02-01

    We derive some general characteristics of the wave function representing a break-up event, in the asymptotic region. They have a strong bearing on the validity of some classical pictures, on the correlation between spatial and momentum variables that develops in the course of the dissociation process and on stringent requirements on the basis sets that are employed to approximate the wave function. Although other calculations are mentioned to underline the generality of our reasonings, we restrict most of the presentation, and all of the illustrations, to the case of ionization.

  11. Experimental Study of Space Star Anomaly in pd Breakup Around 10 MeV/A

    NASA Astrophysics Data System (ADS)

    Yabe, T.; Sagara, K.; Kuroita, S.; Ishibashi, K.; Tamura, T.; Eguchi, Y.; Yashima, K.; Sueta, T.; Shimoda, H.; Maeda, Y.

    2011-05-01

    Cross section of pd breakup at Star configuration (equilateral triangle) was systematically measured at E = 9.5 and 13 MeV/A with varying an angle ? between the Star plane and the beam axis. At 13 MeV/A, Star anomaly appears only around Space Star ( ? = 90°) configuration. At 9.5 MeV/A, same feature was found in our experimental data at ? = 0°-105°, but large difference of about -25% at ? = 124°-180° was reported by Köln group.

  12. Determination of the threshold of the break-up of invariant tori in a class of three frequency Hamiltonian systems

    E-print Network

    C. Chandre; J. Laskar; G. Benfatto; H. R. Jauslin

    2001-05-10

    We consider a class of Hamiltonians with three degrees of freedom that can be mapped into quasi-periodically driven pendulums. The purpose of this paper is to determine the threshold of the break-up of invariant tori with a specific frequency vector. We apply two techniques: the frequency map analysis and renormalization-group methods. The renormalization transformation acting on a Hamiltonian is a canonical change of coordinates which is a combination of a partial elimination of the irrelevant modes of the Hamiltonian and a rescaling of phase space around the considered torus. We give numerical evidence that the critical coupling at which the renormalization transformation starts to diverge is the same as the value given by the frequency map analysis for the break-up of invariant tori. Furthermore, we obtain by these methods numerical values of the threshold of the break-up of the last invariant torus.

  13. Cooperative breakups induced by drop-to-drop interactions in one-dimensional flows of drops against micro-obstacles.

    PubMed

    Schmit, Alexandre; Salkin, Louis; Courbin, Laurent; Panizza, Pascal

    2015-03-28

    Depending on the capillary number at play and the parameters of the flow geometry, a drop may or may not break when colliding with an obstacle in a microdevice. Modeling the flow of one-dimensional trains of monodisperse drops impacting a micro-obstacle, we show numerically that complex dynamics may arise through drop-to-drop hydrodynamic interactions: we observe sequences of breakup events in which the size of the daughter drops created upon breaking mother ones becomes a periodic function of time. We demonstrate the existence of numerous bifurcations between periodic breakup regimes and we establish diagrams mapping the possible breakup dynamics as a function of the governing (physicochemical, hydrodynamic, and geometric) parameters. Microfluidic experiments validate our model as they concur very well with predictions. PMID:25668310

  14. Damage mechanisms of suspended animal cells in agitated bioreactors with and without bubble entrainment

    Microsoft Academic Search

    Kurt T. Kunas; Eleftherios T. Papoutsakis

    1990-01-01

    We show that when freely suspended hybridoma cells are cultured in an agitated bioreactor, two fluid- mechanical mechanisms can cause cell damage and growth retardation. The first is present only when there is a gas phase, and is associated with vortex formation accompanied by bubble entrainment and breakup. In the absence of a vortex and bubble entrainment, cells can be

  15. Spin observables in proton-deuteron scattering and T-invariance test

    NASA Astrophysics Data System (ADS)

    Temerbayev, A. A.; Uzikov, Yu. N.

    2015-01-01

    The total cross section for the interaction of transversely polarized protons p {/p y } and deuterons that have a tensor polarization P {/x z } provides a null-test signal of T-invariance violation under the condition of P invariance. The relevant experiment is planned by the PAX Collaboration at the COSY accelerator with protons accelerated to the energy of 135 MeV. A modified Glauber theory is used here to calculate the differential spin observables A y , C y,y , C xz,y , C z,x , and C x,z and the differential and total cross sections for proton-deuteron scattering in the case of T-even P-even proton-nucleon interactions. This makes it possible to estimate background conditions of the planned experiment.

  16. Incoherent {phi} photo-production from deuteron in SPring-8/LEPS

    SciTech Connect

    Miyabe, M. [Research Center of Nuclear Physics Osaka Univ (Japan)

    2011-10-21

    We present measurements of differential cross sections and decay asymmetries of incoherent {phi}-meson photo-production from the deuteron at forward angles using linearly polarized photons beam in energy range from the production threshold to E = 2.4 GeV. The experiment was performed at the SPring-8/LEPS facility. The differential cross section of incoherent production shows a large suppression compared with the free proton case. The reduction for the deuteron cannot be clearly explained in terms of simple isospin asymmetry. The decay asymmetry of incoherent {phi} photo-production shows that the eta exchange process is small. Since the exclusive K{sup +}K{sup -}p cross section shows the same reduction with incoherent, both the proton and neutron cross section reduce similarly. Consequently, the {pi}-{eta} interference effect is small too. The present results suggest that our understanding of {phi} photo-production within a nucleus should be rearranged.

  17. Collins and Sivers asymmetries on the deuteron from the COMPASS data

    SciTech Connect

    Pagano, Paolo [INFN - Sezione di Trieste, via Valerio, 2 - 34127 Trieste (Italy)

    2005-10-06

    COMPASS is a fixed target experiment presently running at CERN. In 2002, 2003, and 2004 it used a 160 GeV polarized muon beam coming from SPS and scattered off a 6LiD (deuteron) target. The nucleons in the target can be polarized either longitudinally or transversely with respect to the muon beam and 20% of the running time has been devoted to transverse polarization. Hereby the final results for the Collins and the Sivers asymmetries calculated from the data taken in transverse polarization in 2002 are presented. In the forthcoming 2006 run, COMPASS plans to run with a NH3 (proton) target. Projections for the statistical accuracy which will be ultimately achieved on both the proton and the deuteron asymmetries are also given.

  18. Cross-section studies of important neutron and relativistic deuteron reactions

    NASA Astrophysics Data System (ADS)

    Wagner, V.; Suchopár, M.; Vrzalová, J.; Chudoba, P.; Herman, T.; Svoboda, O.; Geier, B.; Krása, A.; Majerle, M.; Kugler, A.; Adam, J.; Baldin, A.; Furman, W.; Kadykov, M.; Khushvaktov, J.; Solnyshkin, A.; Tsoupko-Sitnikov, V.; Tyutyunikov, S.; Zavorka, L.; Vladimirova, N.; Bielewicz, M.; Kilim, S.; Szuta, M.; Strugalska-Gola, E.

    2014-09-01

    The cross-sections of relativistic deuteron reactions on natural copper were studied by the means of activation method. The deuteron beams produced by JINR Nuclotron (Russia) with energies from 1 GeV up to 8 GeV were used. Lack of such cross-sections prevents the usage of copper foils for beam integral monitoring. The copper monitors will help us to improve the beam integral determination during ADS studies. The yttrium samples are very suitable activation detectors for monitoring of neutron fields not only in the ADS studies. But experimental cross-section data for higher energy threshold neutron reactions are still missing. This situation is the reason why we have started to study neutron reactions on yttrium by the means of quasi mono-energetic neutron source based on NPI ?ež cyclotron (Czech Republic).

  19. Nuclear effects in the proton-deuteron Drell-Yan process

    SciTech Connect

    Ehlers, Peter J. [Univ. Washington; Accardi, Alberto [Hampton U., JLAB; Brady, Lucas T.; Melnitchouk, Wally [JLAB

    2014-07-01

    We compute the nuclear corrections to the proton-deuteron Drell-Yan cross section for inclusive dilepton production, which, when combined with the proton-proton cross section, is used to determine the flavor asymmetry in the proton sea, dbar - ubar. In addition to nuclear smearing corrections that are known to be important at large values of the nucleon's parton momentum fraction x_N, we also consider dynamical off-shell nucleon corrections associated with the modifications of the bound nucleon structure inside the deuteron, which we find to be significant at intermediate and large x_N values. We also provide estimates of the nuclear corrections at kinematics corresponding to existing and planned Drell-Yan experiments at Fermilab and J-PARC which aim to determine the dbar/ubar ratio for x < 0.6.

  20. Nuclear effects in the proton-deuteron Drell-Yan process

    NASA Astrophysics Data System (ADS)

    Ehlers, P. J.; Accardi, A.; Brady, L. T.; Melnitchouk, W.

    2014-07-01

    We compute the nuclear corrections to the proton-deuteron Drell-Yan cross section for inclusive dilepton production, which, when combined with the proton-proton cross section, is used to determine the flavor asymmetry in the proton sea, d ¯?u ¯. In addition to nuclear smearing corrections that are known to be important at large values of the nucleon's parton momentum fraction xN, we also consider dynamical off-shell nucleon corrections associated with the modifications of the bound nucleon structure inside the deuteron, which we find to be significant at intermediate and large xN values. We also provide estimates of the nuclear corrections at kinematics corresponding to existing and planned Drell-Yan experiments at Fermilab and J-PARC which aim to determine the d ¯/u ¯ ratio for x?0.6.

  1. Resonant formation of ?(1405) by stopped-K- absorption in the deuteron

    NASA Astrophysics Data System (ADS)

    Esmaili, Jafar; Akaishi, Yoshinori; Yamazaki, Toshimitsu

    2011-05-01

    To solve the current debate on the position of the quasibound K-p state, namely, “?(1405) or ?*(1420),” we propose to measure the T21=T???K¯N ?? invariant-mass spectrum in stopped-K- absorption in the deuteron, since the spectrum, reflecting the soft and hard deuteron momentum distribution, is expected to have a narrow quasifree component with an upper edge of M=1430 MeV/c2, followed by a significant “high-momentum” tail toward the lower mass region, where a resonant formation of ?(1405) of any mass and width in a wide range will be clearly revealed. We introduce a “deviation” spectrum as defined by DEV = OBS (observed or calculated) / QF (nonresonant quasifree), in which the resonant component can be seen as an isolated peak free from the QF shape.

  2. Resonant formation of {Lambda}(1405) by stopped-K{sup -} absorption in the deuteron

    SciTech Connect

    Esmaili, Jafar [RIKEN, Nishina Center, Wako, Saitama 351-0198 (Japan); Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Akaishi, Yoshinori [RIKEN, Nishina Center, Wako, Saitama 351-0198 (Japan); College of Science and Technology, Nihon University, Funabashi, Chiba 274-8501 (Japan); Yamazaki, Toshimitsu [RIKEN, Nishina Center, Wako, Saitama 351-0198 (Japan); Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2011-05-15

    To solve the current debate on the position of the quasibound K{sup -}p state, namely, ''{Lambda}(1405) or {Lambda}*(1420),'' we propose to measure the T{sub 21}=T{sub {Sigma}{pi}<-K}-bar{sub N} {Sigma}{pi} invariant-mass spectrum in stopped-K{sup -} absorption in the deuteron, since the spectrum, reflecting the soft and hard deuteron momentum distribution, is expected to have a narrow quasifree component with an upper edge of M=1430 MeV/c{sup 2}, followed by a significant 'high-momentum' tail toward the lower mass region, where a resonant formation of {Lambda}(1405) of any mass and width in a wide range will be clearly revealed. We introduce a 'deviation' spectrum as defined by DEV = OBS (observed or calculated) / QF (nonresonant quasifree), in which the resonant component can be seen as an isolated peak free from the QF shape.

  3. Measurement of 230Pa and 186Re Production Cross Sections Induced by Deuterons at Arronax Facility

    NASA Astrophysics Data System (ADS)

    Duchemin, Charlotte; Guertin, Arnaud; Metivier, Vincent; Haddad, Ferid; Michel, Nathalie

    2014-02-01

    A dedicated program has been launched on production of innovative radionuclides for PET imaging and for ?- and ? targeted radiotherapy using proton or ? particles at the ARRONAX cyclotron. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Two isotopes dedicated to targeted therapy have been considered: 226Th, a decay product of 230Pa, and 186Re. The production cross sections of 230Pa and 186Re, as well as those of the contaminants created during the irradiation, have been determined by the stacked-foil technique using deuteron beams. Experimental values have been quantified using a referenced cross section. The measured cross sections have been used to determine expected production yields and compared with the calculated values obtained using the Talys code with default parameters.

  4. Final-state interactions in inclusive deep-inelastic scattering from the deuteron

    DOE PAGESBeta

    Cosyn, Wim; Melnitchouk, Wally; Sargsian, Misak M.

    2014-01-01

    We explore the role of final-state interactions (FSI) in inclusive deep-inelastic scattering from the deuteron. Relating the inclusive cross section to the deuteron forward virtual Compton scattering amplitude, a general formula for the FSI contribution is derived in the generalized eikonal approximation, utilizing the diffractive nature of the effective hadron-nucleon interaction. The calculation uses a factorized model with a basis of three resonances with mass W~ 0.6 andmore »Q2 2 increasing in magnitude for lower Q2, but vanishing in the high-Q2 limit due to phase space constraints. The off-shell rescattering contributes at x ~> 0.8 and is taken as an uncertainty on the on-shell result.« less

  5. Resonance Effects in Nuclear Dichroism -- AN Inexpensive Source of Tensor-Polarized Deuterons

    NASA Astrophysics Data System (ADS)

    Seyfarth, H.; Engels, R.; Rathmann, F.; Ströher, H.; Baryshevsky, V.; Rouba, A.; Düweke, C.; Emmerich, R.; Imig, A.; Grigoryev, K.; Mikirtychiants, M.; Vasilyev, A.

    2011-01-01

    The effect of nuclear spin dichroism, predicted by theoretical studies as the appearance of tensor polarization in initially unpolarized beams behind unpolarized or spinless targets, has been studied by measurements with the use of 9.5 to 18.7 MeV unpolarized deuteron beams from the Köln tandem accelerator and graphite targets of areal densities from 36 to 188 mg/cm2. Distinct deviations from the predicted weak effect were observed with a maximum vale of pzz = -(0.28 ± 0.03), measured behind a 129 mg/cm2 target at 14.8 MeV initial beam energy. The present results will allow one to produce tensor-polarized deuteron beams with pzz about -0.30 or +0.25 from initially unpolarized beams by graphite targets of appropriate thickness.

  6. Breakup temperature of target spectators in 197 Au + 197 Au collisions at E/A = 1000 MeV

    NASA Astrophysics Data System (ADS)

    Xi, Hongfei; Odeh, T.; Bassini, R.; Begemann-Blaich, M.; Botvina, A. S.; Fritz, S.; Gaff, S. J.; Groß, C.; Immé, G.; Iori, I.; Kleinevoß, U.; Kunde, G. J.; Kunze, W. D.; Lynen, U.; Maddalena, V.; Mahi, M.; Möhlenkamp, T.; Moroni, A.; Müller, W. F. J.; Nociforo, C.; Ocker, B.; Petruzzelli, F.; Pochodzalla, J.; Raciti, G.; Riccobene, G.; Romano, F. P.; Rubehn, Th.; Saija, A.; Schnittker, M.; Schüttauf, A.; Schwarz, C.; Seidel, W.; Serfling, V.; Sfienti, C.; Trautmann, W.; Trzcinski, A.; Verde, G.; Wörner, A.; Zwieglinski, B.

    1997-12-01

    Breakup temperatures were deduced from double ratios of isotope yields for target spectators produced in the reaction Au + Au at 1000 MeV per nucleon. Pairs of $^{3,4}$He and $^{6,7}$Li isotopes and pairs of $^{3,4}$He and H isotopes (p, d and d, t) yield consistent temperatures after feeding corrections, based on the quantum statistical model, are applied. The temperatures rise with decreasing impact parameter from 4 MeV for peripheral to about 10 MeV for the most central collisions. The good agreement with the breakup temperatures measured previously for projectile spectators at an incident energy of 600 MeV per nucleon confirms the observed universality of the spectator decay at relativistic bombarding energies. The measured temperatures also agree with the breakup temperatures predicted by the statistical multifragmentation model. For these calculations a relation between the initial excitation energy and mass was derived which gives good simultaneous agreement for the fragment charge correlations. The energy spectra of light charged particles, measured at $\\theta_{lab}$ = 150$^{\\circ}$, exhibit Maxwellian shapes with inverse slope parameters much higher than the breakup temperatures. The statistical multifragmentation model, because Coulomb repulsion and sequential decay processes are included, yields light-particle spectra with inverse slope parameters higher than the breakup temperatures but considerably below the measured values. The systematic behavior of the differences suggests that they are caused by light-charged-particle emission prior to the final breakup stage. PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-q

  7. NPR : Dinosaur-Killing Asteroid Traced to Breakup ... http://www.npr.org/templates/story/story.php?stor... 1 of 2 18/09/2007 12:22

    E-print Network

    Claeys, Philippe

    NPR : Dinosaur-Killing Asteroid Traced to Breakup ... http estimated to be 60 kilometers in diameter. Space Dinosaur-Killing Asteroid Traced to Breakup Event. This was the asteroid that wiped out the dinosaurs and gave mammals a chance. At least that's what a team of planetary

  8. Analyses of Kolmogorov’s model of breakup and its application into Lagrangian computation of liquid sprays under air-blast atomization

    Microsoft Academic Search

    M. A. Gorokhovski; V. L. Saveliev

    2003-01-01

    This paper considers the breakup of liquid drops at the large Weber number within the framework of Kolmogorov’s scenario of breakup. The population balances equation for droplet radius distribution is written to be an invariant under the group of scaling transformations. It is shown that due to this symmetry, the long-time limit solution of this equation is a power function.

  9. Parity-Violating Electron Deuteron Scattering and the Proton's Neutral Weak Axial Vector Form Factor

    Microsoft Academic Search

    Takeyasu Ito; Todd Averett; David Barkhuff; Guillaume Batigne; Douglas Beck; Elizabeth Beise; A. Blake; Herbert Breuer; Robert Carr; Benjamin Clasie; Silviu Covrig; Areg Danagoulian; George Dodson; Karen Dow; Dipangkar Dutta; Manouchehr Farkhondeh; Bradley Filippone; W. Franklin; Christophe Furget; Haiyan Gao; Juncai Gao; Kenneth Gustafsson; Lars Hannelius; R. Hasty; A. M. Hawthorne-Allen; M. C. Herda; C. E. Jones; Paul King; Wolfgang Korsch; Stanley Kowalski; Serge Kox; Kevin Kramer; P. Lee; Jinghua Liu; Jeffery Martin; Robert McKeown; B. Mueller; Mark Pitt; Bradley Plaster; G. Quéméner; J.-S. Réal; J. Ritter; Julie Roche; V. Savu; Rocco Schiavilla; J. Seely; Damon Spayde; Riad Suleiman; S. Taylor; Raphael Tieulent; Bryan Tipton; E. Tsentalovich; Steven Wells; Bin Yang; Jing Yuan; Junho Yun; Townsend Zwart

    2004-01-01

    We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2=0.038 (GeV\\/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51±0.57 (stat)±0.58 (syst) ppm is consistent with theoretical predictions. We also

  10. Energy losses of muons, pions, protons, and deuterons channeled in Si

    PubMed

    Valdes; Vargas; Arista

    2000-11-27

    The energy loss of positive muons, pions, protons, and deuterons channeled in Si crystals has been investigated by computer simulation. The model considers the individual trajectories of particles inside the target and calculates the electronic energy loss for each particle history. The results show important differences in the energy loss distributions, stopping powers, and straggling values for low and intermediate energies, as a consequence of channeling effects. PMID:11082638

  11. Simulation of mode converted ion Bernstein wave - beam deuteron interactions on TFTR

    Microsoft Academic Search

    Mark Herrmann; Nathaniel Fisch

    1998-01-01

    Experiments on TFTR have documented strong interactions between mode converted ion Bernstein waves (MCIBW) and beam deuterons(D. S. Darrow et al.), Nucl. Fusion 36, 509 (1996).^,(N. J. Fisch et al.), IAEA, Vol. 1, p. 271 (1996). This is of particular interest in the study of alpha channelling, since the most promising scenarios(M. C. Herrmann and N. J. Fisch, Phys. Rev.

  12. Deuteron and triton magnetic moments from NMR spectra of the hydrogen molecule

    E-print Network

    Puchalski, Mariusz; Pachucki, Krzysztof

    2015-01-01

    We present a theory and calculations of the nuclear magnetic shielding with finite nuclear mass effects and determine magnetic moments of deuteron and triton using the known NMR spectra of HD and HT molecules. The results $\\mu_d = 0.857\\,438\\,234\\,6(53)\\;\\mu_N$ and $\\mu_t = 2.978\\,962\\,471(10)\\;\\mu_N$ are more accurate and in a good agreement with the currently accepted values.

  13. Dissecting Deuteron Compton Scattering I: The Observables with Polarised Initial States

    E-print Network

    Harald W. Griesshammer

    2013-08-19

    A complete set of linearly independent observables in Compton scattering with arbitrarily polarised real photons off an arbitrarily polarised spin-1 target is introduced, for the case that the final-state polarisations are not measured. Adopted from the one widely used e.g. in deuteron photo-dissociation, it consists of 18 terms: the unpolarised cross section, the beam asymmetry, 4 target asymmetries and 12 asymmetries in which both beam and target are polarised. They are expressed by the helicity amplitudes and -- where available -- related to observables discussed by other authors. As application to deuteron Compton scattering, their dependence on the (isoscalar) scalar and spin dipole polarisabilities of the nucleon is explored in Chiral Effective Field Theory with dynamical Delta(1232) degrees of freedom at order e^2\\delta^3. Some asymmetries are sensitive to only one or two dipole polarisabilities, making them particularly attractive for experimental studies. At a photon energy of 100 MeV, a set of 5 observables is identified from which one may be able to extract the spin polarisabilities of the nucleon. These are experimentally realistic but challenging and mostly involve tensor-polarised deuterons. Relative to Compton scattering from a nucleon, sensitivity to the "mixed" spin polarisabilities \\gamma_{E1M2} and \\gamma_{M1E2} is increased because of interference with the D wave component of the deuteron and with its pion-exchange current. An interactive Mathematica 9.0 notebook with results for all observables at photon energies up to 120 MeV is available from hgrie@gwu.edu.

  14. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D. [Rutgers, State University of New Jersey, Piscataway, New Jersey 08854 (United States); Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Camsonne, A. [Universite Blaise Pascal/IN2P3, F-63177 Aubiere (France); Chen, J. P.; Chudakov, E.; Gaskell, D.; Hansen, O.; Higinbotham, D. W.; Jager, C. W. de; Jones, M. K.; Lerose, J.; Michaels, R. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)] (and others)

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  16. Effect of deuteron temperature on iron forbidden line intensities in rf-heated tokamak plasmas

    SciTech Connect

    Sato, K.; Suckewer, S.; Wouters, A.

    1987-05-01

    Two line ratios, the forbidden line at 845.5 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s/sup 2/2p /sup 2/P/sub 3/2/) to the allowed line at 135.7 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s2p/sup 2/ /sup 2/D/sub 3/2/) in Fe XXII and the forbidden line at 592.1 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 1/D/sub 2/) to the forbidden line at 1118.2 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 3/P/sub 1/) in Fe XIX, have been measured as the ion temperature-sensitive line ratios during rf heating in the Princeton Large Torus. The results indicate that deuteron collisions in plasmas of high deuteron temperature have a noticeable effect on the intensity of the forbidden lines. Measured relative intensities are compared with values from level population calculations, which include deuteron collisional excitation between the levels of the ground configuration. The agreement between the observed and calculated ratios is within 30%. A method for deuteron (or proton) temperature measurement in tokamak plasmas is discussed. 37 refs.

  17. The magnetic form factor of the deuteron in chiral effective field theory

    E-print Network

    S. Kolling; E. Epelbaum; D. R. Phillips

    2012-09-05

    We calculate the magnetic form factor of the deuteron up to O(eP^4) in the chiral EFT expansion of the electromagnetic current operator. The two LECs which enter the two-body part of the isoscalar NN three-current operator are fit to experimental data, and the resulting values are of natural size. The O(eP^4) description of G_M agrees with data for momentum transfers Q^2 < 0.35 GeV^2.

  18. Aligned breakup of heavy nuclear systems as a new type of deep inelastic collisions at small impact parameters

    SciTech Connect

    Wilczynski, J.; Swiderski, L. [Andrzej Soltan Institute for Nuclear Studies, Swierk/Warsaw (Poland); Skwira-Chalot, I.; Siwek-Wilczynska, K. [Institute of Experimental Physics, University of Warsaw, Warsaw (Poland); Pagano, A.; Cardella, G.; De Filippo, E.; La Guidara, E.; Papa, M.; Pirrone, S. [INFN, Sezione di Catania, Catania (Italy); Amorini, F.; Anzalone, A.; Cavallaro, S.; Colonna, M.; Di Toro, M.; Maiolino, C.; Porto, F.; Rizzo, F.; Russotto, P. [INFN, Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Auditore, L. [INFN, Gruppo Collegato di Messina and Dipartimento di Fisica, Universita di Messina, Messina (Italy)

    2010-06-15

    An interesting process of violent reseparation of a heavy nuclear system into three or four fragments of comparable size was recently observed in {sup 197}Au+{sup 197}Au collisions at 15 MeV/nucleon. Combined analysis of the binary deep inelastic events and the ternary and quaternary breakup events demonstrates that the newly observed ternary and quaternary reactions belong to the same wide class of deep inelastic collisions as the conventional (binary) damped reactions. It is shown that the ternary and quaternary breakup reactions occur at extremely inelastic collisions corresponding to small impact parameters, while more peripheral collisions lead to well-known binary deep inelastic reactions.

  19. Developing the yearning in situations of loss scale: convergent and discriminant validity for bereavement, romantic breakup, and homesickness.

    PubMed

    O'Connor, Mary-Frances; Sussman, Tamara J

    2014-01-01

    Yearning is common in situations involving loss, and a hallmark of complicated grief. To study yearning empirically, the present study develops the Yearning in Situations of Loss scale (YSL), which measures yearning bereavement, romantic breakup, or homesickness. In Study 1, we identified shared characteristics across situations of loss, tested an initial version and removed items with the lowest item-scale reliability. In Study 2, the 21-item YSL was compared to scales of anxiety, depression, and loneliness, and existing scales, relevant to each loss situation. The YSL showed discriminant and convergent validity that applies to bereavement, romantic breakup, and homesickness. PMID:24758215

  20. Determination of the beam-spin asymmetry of deuteron photodisintegration in the energy region E?=1.1 -2.3 GeV

    NASA Astrophysics Data System (ADS)

    Zachariou, N.; Ilieva, Y.; Berman, B. L.; Ivanov, N. Ya.; Sargsian, M. M.; Avakian, R.; Feldman, G.; Nadel-Turonski, P.; Adhikari, K. P.; Adikaram, D.; Anderson, M. D.; Pereira, S. Anefalos; Avakian, H.; Badui, R. A.; Baltzell, N. A.; Battaglieri, M.; Baturin, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Cao, T.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, L.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Fradi, A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jiang, H.; Jo, H. S.; Joo, K.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P. T.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Mokeeev, V. I.; Montgomery, R. A.; Moutarde, H.; Camacho, C. Munoz; Net, L. A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Phelps, W.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Senderovich, I.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D.; Wei, X.; Wood, M. H.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-05-01

    The beam-spin asymmetry, ? , for the reaction ? d ?p n has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, ?c .m ., between 25? and 160?. These are the first measurements of beam-spin asymmetries at ?c .m .=90? for photon-beam energies above 1.6 GeV, and the first measurements for angles other than ?c .m .=90? . The angular and energy dependence of ? is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.

  1. Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region $E_?=1.1-2.3$ GeV

    DOE PAGESBeta

    Zachariou, Nicholas [University of South Carolina; et. al.,

    2015-05-01

    The beam-spin asymmetry, Sigma, for the reaction ?d-->pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, thetac.m., between 25degrees and 160degrees. These are the first measurements of beam-spin asymmetries at thetac.m.=90degrees for photon-beam energies above 1.6 GeV, and the first measurements for angles other than thetac.m.=90degrees. The angular and energy dependence of Sigma is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.

  2. Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region $E_?=1.1-2.3$ GeV

    DOE PAGESBeta

    Zachariou, Nicholas; et. al.,

    2015-05-01

    The beam-spin asymmetry, Sigma, for the reaction ?d-->pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, thetac.m., between 25degrees and 160degrees. These are the first measurements of beam-spin asymmetries at thetac.m.=90degrees for photon-beam energies above 1.6 GeV, and the first measurements for angles other than thetac.m.=90degrees. The angular and energy dependence of Sigma is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition regionmore »between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.« less

  3. Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region $E_?=1.1-2.3$ GeV

    E-print Network

    Nicholas Zachariou; Yordanka Ilieva; Nikolay Ya. Ivanov; Misak M Sargsian; Robert Avakian; Gerald Feldman; Pawel Nadel-Turonski; K. P. Adhikari; D. Adikaram; M. D. Anderson; S. Anefalos Pereira; H. Avakian; R. A. Badui; N. A. Baltzell; M. Battaglieri; V. Baturin; I. Bedlinskiy; A. S. Biselli; W. J. Briscoe; W. K. Brooks; V. D. Burkert; T. Cao; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; L. Colaneri; P. L. Cole; N. Compton; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; G. Fedotov; S. Fegan; A. Filippi; J. A. Fleming; T. A. Forest; A. Fradi; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; D. I. Glazier; E. Golovatch; R. W. Gothe; K. A. Griffioen; M. Guidal; K. Hafidi; C. Hanretty; N. Harrison; M. Hattawy; K. Hicks; D. Ho; M. Holtrop; S. M. Hughes; D. G. Ireland; B. S. Ishkhanov; E. L. Isupov; H. Jiang; H. S. Jo; K. Joo; D. Keller; G. Khachatryan; M. Khandaker; A. Kim; W. Kim; F. J. Klein; V. Kubarovsky; P. Lenisa; K. Livingston; H. Y. Lu; I . J . D. MacGregor; N. Markov; P. T. Mattione; B. McKinnon; T. Mineeva; M. Mirazita; V. I. Mokeeev; R. A. Montgomery; H. Moutarde; C. Munoz Camacho; L. A. Net; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; K. Park; E. Pasyuk; W. Phelps; J. J. Phillips; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; Y. Prok; D. Protopopescu; A. J. R. Puckett; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; P. Roy; F. Sabatié; C. Salgado; D. Schott; R. A. Schumacher; E. Seder; I. Senderovich; Y. G. Sharabian; Iu. Skorodumina; G. D. Smith; D. I. Sober; D. Sokhan; N. Sparveris; S. Stepanyan; S. Strauch; V. Sytnik; M. Taiuti; Ye Tian; M. Ungaro; H. Voskanyan; E. Voutier; N. K. Walford; D. Watts; X. Wei; M. H. Wood; L. Zana; J. Zhang; Z. W. Zhao; I. Zonta; for the CLAS collaboration

    2015-03-18

    The beam-spin asymmetry, $\\Sigma$, for the reaction $\\gamma d\\rightarrow pn$ has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, $\\theta_{c.m.}$, between $25^\\circ$ and $160^\\circ$. These are the first measurements of beam-spin asymmetries at $\\theta_{c.m.}=90^\\circ$ for photon-beam energies above 1.6 GeV, and the first measurements for angles other than $\\theta_{c.m.}=90^\\circ$. The angular and energy dependence of $\\Sigma$ is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition region between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.

  4. Determination of the beam-spin asymmetry of deuteron photodisintegration in the energy region E?=1.1 –2.3 GeV

    DOE PAGESBeta

    Zachariou, N.; Ilieva, Y.; Ivanov, N. Ya.; Sargsian, M. M.; Avakian, R.; Feldman, G.; Nadel-Turonski, P.

    2015-05-01

    The beam-spin asymmetry, ?, for the reaction ?d???pn has been measured using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab) for six photon-energy bins, between 1.1 and 2.3 GeV, and proton angles in the center-of-mass frame, ?c.m., between 25° and 160°. These are the first measurements of beam-spin asymmetries at ?c.m.=90° for photon-beam energies above 1.6 GeV, and the first measurements for angles other than ?c.m.=90°. The angular and energy dependence of ? is expected to aid in the development of QCD-based models to understand the mechanisms of deuteron photodisintegration in the transition regionmore »between hadronic and partonic degrees of freedom, where both effective field theories and perturbative QCD cannot make reliable predictions.« less

  5. Continental breakup and the dynamics of rifting in back-arc basins: The Gulf of Lion margin

    NASA Astrophysics Data System (ADS)

    Jolivet, Laurent; Gorini, Christian; Smit, Jeroen; Leroy, Sylvie

    2015-04-01

    Deep seismic profiles and subsidence history of the Gulf of Lion margin reveal an intense stretching of the distal margin and strong postrift subsidence, despite weak extension of the onshore and shallow offshore portions of the margin. We revisit this evolution from the geological interpretation of an unpublished multichannel seismic profile and other published geophysical data. We show that an 80 km wide domain of thin lower continental crust, the "Gulf of Lion metamorphic core complex," is present in the ocean-continent transition zone and exhumed mantle makes the transition with oceanic crust. The exhumed lower continental crust is bounded upward and downward by shallow north dipping detachments. The presence of exhumed lower crust in the deep margin explains the discrepancy between the amount of extension deduced from normal faults in the upper crust and total extension. We discuss the mechanism responsible for exhumation and present two scenarios: the first one involving a simple coupling between mantle extension due to slab retreat and crustal extension and the second one involving extraction of the lower crust and mantle from below the margin by the southeastward flow of hot asthenosphere in the back-arc region during slab rollback. In both scenarios, the combination of Eocene crustal thickening related to the Pyrenees, the nearby volcanic arc, and a shallow lithosphere-asthenosphere boundary weakened the upper mantle and lower crust enough to make them flow southeastward. The overall hot geodynamic environment also explains the subaerial conditions during most of the rifting stage and the delayed subsidence after breakup.

  6. Measurement of the Electric and Magnetic Elastic Structure Functions of the Deuteron at Large Momentum Transfers

    SciTech Connect

    Riad Suleiman

    1999-10-01

    The deuteron elastic structure functions, A(Q{sup 2}) and B(Q{sup 2}), have been extracted from cross section measurements of elastic electron-deuteron scattering in coincidence using the Continuous Electron Beam Accelerator and Hall A Facilities of Jefferson Laboratory. Incident electrons were scattered off a high-power cryogenic deuterium target. Scattered electrons and recoil deuterons were detected in the two High Resolution Spectrometers of Hall A. A(Q{sup 2}) was extracted from forward angle cross section measurements in the squared four-momentum transfer range 0.684 ? Q{sup 2} ? 5.90 (GeV/c){sup 2}. B(Q{sup 2}) was determined by means of a Rosenbluth separation in the range 0.684 ? Q{sup 2} ? 1.325 (GeV/c){sup 2}. 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. The results are expected to provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  7. Measurement of the deuteron elastic structure functions at large momentum transfers

    SciTech Connect

    Kathy McCormick

    1999-08-01

    The cross section for elastic electron-deuteron scattering has been measured using the Hall A Facility of Jefferson Laboratory. Scattered electrons and recoiling deuterons were detected in coincidence in the two 4 GeV/c High Resolution Spectrometers (HRS) of Hall A. The deuteron elastic structure functions A(Q{sup 2}) and B(Q{sup 2}) have been extracted from these data. Results for the measurement of A(Q{sup 2}) in the range of 0.7 ? Q{sup 2} ? 6.0 (GeV/c){sup 2} are reported. Results for the magnetic structure function, B(Q{sup 2}), are presented in the range of 0.7 ? Q{sup 2} ? 1.35 (GeV/c){sup 2}. The results for both structure functions are compared to predictions of meson-nucleon based models, both with and without the inclusion of meson-exchange currents. The A(Q{sup 2}) results are compared to predictions of the dimensional scaling quark model and perturbative quantum chromodynamics. The results can provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  8. Deuteron beam interaction with Li jet for a neutron source test facility

    SciTech Connect

    Hassanein, A.

    1995-09-01

    Testing and evaluating candidate fusion reactor materials in a high-flux, high-energy neutron environment are critical to the success and economic feasibility of a fusion device. The current understanding of materials behavior in fission-like environments and existing fusion facilities is insufficient to ensure the necessary performance of future fusion reactor components. An accelerator-based deuterium-lithium system to generate the required high neutron flux for material testing is considered to be the most promising approach in the near future. In this system, a high-energy (30-40 MeV) deuteron beam impinges on a high-speed (10-20 m/s) lithium jet to produce the high-energy (>14 MeV) neutrons required to simulate a fusion environment via the Li (d,n) nuclear stripping reaction. Interaction of the high-energy deuteron beam and the subsequent response of the high-speed lithium jet are evaluated in detail. Deposition of the deuteron beam, jet-thermal hydraulic response, lithium-surface vaporization rate, and dynamic stability of the jet are modeled. It is found that lower beam kinetic energies produce higher surface temperature and consequently higher Li vaporization rates. Larger beam sizes significantly reduce both bulk and surface temperatures. Thermal expansion and dynamic velocities (normal to jet direction) due to beam energy deposition and momentum transfer are much lower than jet flow velocity and decrease substantially at lower beam current densities.

  9. Three nucleon force effects in intermediate-energy deuteron analyzing powers for dp elastic scattering

    SciTech Connect

    Sekiguchi, K. [Department of Physics, Tohoku University, Sendai, 980-8578 (Japan); Okamura, H. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka, 567-0047 (Japan); Sakamoto, N.; Sakaguchi, S.; Sasano, M. [RIKEN Nishina Center, Wako, 351-0198 (Japan); Suzuki, H. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8571 (Japan); Dozono, M.; Wakasa, T. [Department of Physics, Kyushu University, Fukuoka, 812-8581 (Japan); Maeda, Y.; Saito, T. [Faculty of Engineering, University of Miyazaki, Miyazaki, 889-2192 (Japan); Sakai, H. [RIKEN Nishina Center, Wako, 351-0198 (Japan); Department of Physics, University of Tokyo, Tokyo, 113-0033 (Japan); Shimizu, Y. [Center for Nuclear Study, University of Tokyo, Tokyo, 113-0033 (Japan); Yako, K. [Department of Physics, University of Tokyo, Tokyo, 113-0033 (Japan); Witala, H.; Golak, J. [Institute of Physics, Jagiellonian University, PL-30059 Cracow (Poland); Gloeckle, W. [Institut fuer theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Kamada, H. [Department of Physics, Kyushu Institute of Technology, Kitakyushu 804-8550 (Japan); Nogga, A. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, D-52428 Juelich (Germany)

    2011-06-15

    A complete high precision set of deuteron analyzing powers for elastic deuteron-proton (dp) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m. backward angles of {theta}{sub c.m.} > or approx. 120 deg. for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data.

  10. Measurement of the electric and magnetic elastic structure functions of the deuteron at large momentum transfers

    NASA Astrophysics Data System (ADS)

    Suleiman, Riad Suleiman

    The deuteron elastic structure functions, A( Q2) and B(Q 2), have been extracted from cross section measurements of elastic electron-deuteron scattering in coincidence using the Continuous Electron Beam Accelerator and Hall A Facilities of Jefferson Laboratory. Incident electrons were scattered off a high- power cryogenic deuterium target. Scattered electrons and recoil deuterons were detected in the two High Resolution Spectrometers of Hall A. A(Q2) was extracted from forward angle cross section measurements in the squared four-momentum transfer range 0.684 <= Q2 <= 5.90 (GeV/C) 2. B(Q2) was determined by means of a Rosenbluth separation in the range 0.684 <= Q 2 <= 1.325 (GeV/c)2. 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. The results are expected to provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  11. Quark Loop Contributions to Neutron, Deuteron, and Mercury EDMs from Supersymmetry without R parity

    E-print Network

    Chan-Chi Chiou; Otto C. W. Kong; Rishikesh D. Vaidya

    2007-05-27

    We present a detailed analysis of the neutron, deuteron and mercury electric dipole moment from supersymmetry without R parity, focusing on the quark-scalar loop contributions. Being proportional to top Yukawa and top mass, such contributions are often large. Analytical expressions illustrating the explicit role of the R-parity violating parameters are given following perturbative diagonalization of mass-squared matrices for the scalars. Dominant contributions come from the combinations $B_i \\lambda^{\\prime}_{ij1}$ for which we obtain robust bounds. It turns out that neutron and deuteron EDMs receive much stronger contributions than mercury EDM and any null result at the future deuteron EDM experiment or Los Alamos neutron EDM experiment can lead to extra-ordinary constraints on RPV parameter space. Even if R-parity violating couplings are real, CKM phase does induce RPV contribution and for some cases such a contribution is as strong as contribution from phases in the R-parity violating couplings.Hence, we have bounds directly on $|B_i \\lambda^{\\prime}_{ij1}|$ even if the RPV parameters are all real. Interestingly, even if slepton mass and/or $\\mu_0$ is as high as 1 TeV, it still leads to neutron EDM that is an order of magnitude larger than the sensitivity at Los Alamos experiment. Since the results are not much sensitive to $\\tan \\beta$, our constraints will survive even if other observables tighten the constraints on $\\tan \\beta$.

  12. Quark Loop Contributions to Neutron, Deuteron, and Mercury EDMs from Supersymmetry without R parity

    E-print Network

    Chiou, Chan-Chi; Vaidya, Rishikesh D

    2007-01-01

    We present a detailed analysis of the neutron, deuteron and mercury electric dipole moment from supersymmetry without R parity, focusing on the quark-scalar loop contributions. Being proportional to top Yukawa and top mass, such contributions are often large. Analytical expressions illustrating the explicit role of the R-parity violating parameters are given following perturbative diagonalization of mass-squared matrices for the scalars. Dominant contributions come from the combinations $B_i \\lambda^{\\prime}_{ij1}$ for which we obtain robust bounds. It turns out that neutron and deuteron EDMs receive much stronger contributions than mercury EDM and any null result at the future deuteron EDM experiment or Los Alamos neutron EDM experiment can lead to extra-ordinary constraints on RPV parameter space. Even if R-parity violating couplings are real, CKM phase does induce RPV contribution and for some cases such a contribution is as strong as contribution from phases in the R-parity violating couplings.Hence, we h...

  13. Chiral effective theory predictions for deuteron form factor ratios at low Q^2

    E-print Network

    Daniel R. Phillips

    2006-08-13

    We use chiral effective theory to predict the deuteron form factor ratio G_C/G_Q as well as ratios of deuteron to nucleon form factors. These ratios are calculated to next-to-next-to-leading order. At this order the chiral expansion for the NN isoscalar charge operator (including consistently calculated 1/M corrections) is a parameter-free prediction of the effective theory. Use of this operator in conjunction with NLO and NNLO chiral effective theory wave functions produces results that are consistent with extant experimental data for Q^2 < 0.35 GeV^2. These wave functions predict a deuteron quadrupole moment G_Q(Q^2=0)=0.278-0.282 fm^2-with the variation arising from short-distance contributions to this quantity. The variation is of the same size as the discrepancy between the theoretical result and the experimental value. This motivates the renormalization of G_Q via a two-nucleon operator that couples to quadrupole photons. After that renormalization we obtain a robust prediction for the shape of G_C/G_Q at Q^2 < 0.3 GeV^2. This allows us to make precise, model-independent predictions for the values of this ratio that will be measured at the lower end of the kinematic range explored at BLAST. We also present results for the ratio G_C/G_M.

  14. Inviscid Breakup of Bubbles and Drops With and Without Surface Charge

    NASA Astrophysics Data System (ADS)

    Burton, Justin; Taborek, Peter

    2010-11-01

    We present boundary-integral simulations of the breakup of inviscid bubbles and droplets, with and without surface charge. In our simulations, an inner fluid volume of density ?1 is surrounded by an exterior fluid of infinite extent and density ?2. When there is no charge on the surface, we see excellent agreement with previous work, except for intermediate density ratios, where the simulations are plagued by oscillatory instabilities not observed in experiments [1]. With the addition of surface charge, initially spherical drops and bubbles are unstable to small perturbations above a critical surface charge density. For the droplet limit, the charged drop forms a "lemon" shape before ejecting a highly charged jet from the tips of the "lemon," where the size of the jet scales with the square of the inverse surface conductivity. For the bubble limit, we find that fission always takes place by the formation of a "peanut"-shaped bubble, where breakup takes place at the center of the bubble, regardless of surface conductivity. For intermediate densities, combinations of droplet and bubble fission are observed.[4pt] [1] J.C. Burton and P. Taborek, Phys. Rev. Lett. 101, 214502 (2008)

  15. Structure of 23Al from the one-proton breakup reaction and astrophysical implications

    NASA Astrophysics Data System (ADS)

    Banu, A.; Trache, L.; Carstoiu, F.; Achouri, N. L.; Bonaccorso, A.; Catford, W. N.; Chartier, M.; Dimmock, M.; Fernández-Domínguez, B.; Freer, M.; Gaudefroy, L.; Horoi, M.; Labiche, M.; Laurent, B.; Lemmon, R. C.; Negoita, F.; Orr, N. A.; Paschalis, S.; Patterson, N.; Paul, E. S.; Petri, M.; Pietras, B.; Roeder, B. T.; Rotaru, F.; Roussel-Chomaz, P.; Simmons, E.; Thomas, J. S.; Tribble, R. E.

    2011-07-01

    The ground state of the proton-rich nucleus 23Al has been studied by one-proton removal on a carbon target at about 50 MeV/nucleon using the EXOGAM + SPEG experimental setup at GANIL. Longitudinal momentum distributions of the 22Mg breakup fragments, inclusive and in coincidence with ? rays de-exciting the residues, were measured. The ground-state structure of 23Al is found to be a configuration mixing of a d-orbital valence proton coupled to four core states—0gs+, 21+, 41+, 42+. We confirm the ground state spin and parity of 23Al as J?=5/2+. The measured exclusive momentum distributions are compared with extended Glauber model calculations to extract spectroscopic factors and asymptotic normalization coefficients (ANCs). The spectroscopic factors are presented in comparison with those obtained from large-scale shell model calculations. We determined the asymptotic normalization coefficient of the nuclear system 23Algs ? 22Mg(0+) + p to be Cd5/22(23Algs)=(3.90±0.44)×103fm-1, and used it to infer the stellar reaction rate of the direct radiative proton capture 22Mg(p,?)23Al. Astrophysical implications related to 22Na nucleosynthesis in ONe novae and the use of one-nucleon breakup at intermediate energies as an indirect method in nuclear astrophysics are discussed.

  16. Experimental and numerical investigation of microjet breakup of dilute polymer solutions

    NASA Astrophysics Data System (ADS)

    van Hoeve, Wim; Kamphorst, Vincent; Versluis, Michel; Lohse, Detlef

    2010-11-01

    Droplet formation from the breakup of a microjet of dilute polymer solution is investigated using ultra high-speed imaging up to 1 million frames per second and by means of a one-dimensional model based on the slender-jet approximation. A liquid emanating from a nozzle at sufficiently large velocity forms a jet that is inherently unstable and spontaneously breaks up into droplets to minimize its surface energy. The addition of a small amount of long flexible polymers (i.e. polyethylene oxide) to the liquid dramatically influences this breakup process. In the final stage of the collapse -- when the shear rate in the liquid increases -- the polymer chains stretch and parallelize in the direction of the main flow, which results in a significantly increase of the local viscosity, and hence strong non-Newtonian behaviour. In this work we make a direct comparison between the ultra high-speed imaging results and those obtained from a simplified one-dimensional model.

  17. Deformation and break-up of viscoelastic droplets in confined shear flow

    E-print Network

    A. Gupta; M. Sbragaglia

    2014-06-16

    The deformation and break-up of Newtonian/viscoelastic droplets are studied in confined shear flow. Our numerical approach is based on a combination of Lattice-Boltzmann models (LBM) and finite difference schemes, the former used to model two immiscible fluids with variable viscous ratio, and the latter used to model the polymer dynamics. The kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin's closure (FENE-P). We quantify the droplet response by changing the polymer relaxation time $\\tau_P$, the maximum extensibility $L$ of the polymers, and the degree of confinement, i.e. the ratio of the droplet diameter to gap spacing. In unconfined shear flow, the effects of droplet viscoelasticity on the critical Capillary number $\\mbox{Ca}_{\\mbox{\\tiny{cr}}}$ for break-up are moderate in all cases studied. However, in confined conditions a different behaviour is observed: the critical Capillary number of a viscoelastic droplet increases or decreases, depending on the maximum elongation of the polymers, the latter affecting the extensional viscosity of the polymeric solution. Force balance is monitored in the numerical simulations to validate the physical picture.

  18. Deformation and break-up of viscoelastic droplets Using Lattice Boltzmann Models

    E-print Network

    Anupam Gupta; Mauro Sbragaglia

    2014-11-09

    We investigate the break-up of Newtonian/viscoelastic droplets in a viscoelastic/Newtonian matrix under the hydrodynamic conditions of a confined shear flow. Our numerical approach is based on a combination of Lattice-Boltzmann models (LBM) and Finite Difference (FD) schemes. LBM are used to model two immiscible fluids with variable viscosity ratio (i.e. the ratio of the droplet to matrix viscosity); FD schemes are used to model viscoelasticity, and the kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin's closure (FENE-P). We study both strongly and weakly confined cases to highlight the role of matrix and droplet viscoelasticity in changing the droplet dynamics after the startup of a shear flow. Simulations provide easy access to quantities such as droplet deformation and orientation and will be used to quantitatively predict the critical Capillary number at which the droplet breaks, the latter being strongly correlated to the formation of multiple neckings at break-up. This study complements our previous investigation on the role of droplet viscoelasticity (A. Gupta \\& M. Sbragaglia, {\\it Phys. Rev. E} {\\bf 90}, 023305 (2014)), and is here further extended to the case of matrix viscoelasticity.

  19. Liquid jet breakup and atomization in rocket chambers under dense spray conditions

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Cheung, Fan-Bill; Woodward, Roger D.; Garner, Kenneth N.

    1991-01-01

    Two advanced diagnostic techniques were established and employed in this project. The first technique involves the use of a real-time x ray radiography system along with a high-speed CCD Xybion camera and an advanced digital image processor to investigate the breakup processes of the liquid core. The focus of this part of the project is to determine the inner structure of the liquid jet and via thin sheets of laser light, with the scatters light being photographed by a Xybion electronic camera synchronized to the laser pulse. This technique, which is capable of recording the breakup event occurring within 25 nano-seconds, enables us to freeze the motions of the jet and liquid droplets. The focus of this part of the project is to determine the outer structure of the liquid jet and to discover the configuration of the surface waves, the spray pattern, and the droplet size distribution in the non-dilute region. Results obtained by these two advanced diagnostic techniques will provide the much needed database for model development and accurate prediction of engine performance. The present work also represents a breakthrough in the area of advanced diagnostics of dense sprays.

  20. Breakup and finite-range effects on the 8B(d,n ) 9C reaction

    NASA Astrophysics Data System (ADS)

    Fukui, Tokuro; Ogata, Kazuyuki; Yahiro, Masanobu

    2015-01-01

    The astrophysical factor of 8B(p,? ) 9C at zero energy, S18(0 ) , is determined by a three-body coupled-channels analysis of the transfer reaction 8B(d,n ) 9C at 14.4 MeV/nucleon. Effects of the breakup channels of d and 9C are investigated with the continuum-discretized coupled-channels method. It is found that, in the initial and final channels, respectively, the transfer process through the breakup states of d and 9C , its interference with that through their ground states in particular, gives a large increase in the transfer cross section. The finite-range effects with respect to the proton-neutron relative coordinate are found to be about 20%. As a result of the present analysis, S18(0 ) =22 ±6 eV b is obtained, which is smaller than the result of the previous distorted-wave Born approximation analysis by about 51%.

  1. Investigation and Comparison between New Satellite Impact Test Results and NASA Standard Breakup Model

    NASA Technical Reports Server (NTRS)

    Sakuraba, K.; Tsuruda, Y.; Hanada, T.; Liou, J.-C.; Akahoshi, Y.

    2007-01-01

    This paper summarizes two new satellite impact tests conducted in order to investigate on the outcome of low- and hyper-velocity impacts on two identical target satellites. The first experiment was performed at a low velocity of 1.5 km/s using a 40-gram aluminum alloy sphere, whereas the second experiment was performed at a hyper-velocity of 4.4 km/s using a 4-gram aluminum alloy sphere by two-stage light gas gun in Kyushu Institute of Technology. To date, approximately 1,500 fragments from each impact test have been collected for detailed analysis. Each piece was analyzed based on the method used in the NASA Standard Breakup Model 2000 revision. The detailed analysis will conclude: 1) the similarity in mass distribution of fragments between low and hyper-velocity impacts encourages the development of a general-purpose distribution model applicable for a wide impact velocity range, and 2) the difference in area-to-mass ratio distribution between the impact experiments and the NASA standard breakup model suggests to describe the area-to-mass ratio by a bi-normal distribution.

  2. Vibration and Nonlinear Resonance in the Break-up of an Underwater Bubble

    E-print Network

    Lai, Lipeng; Fezzaa, Kamel; Zhang, Wendy W; Nagel, Sidney R

    2013-01-01

    We use high-speed X-ray phase-contrast imaging, weakly nonlinear analysis and boundary integral simulations to characterize the final stage of underwater bubble break-up. The X-ray imaging study shows that an initial azimuthal perturbation to the shape of the bubble neck gives rise to oscillations that increasingly distort the cross-section shape. These oscillations terminate in a pinch-off where the bubble surface develops concave regions that contact similar to what occurs when two liquid drops coalesce. We also present a weakly nonlinear analysis that shows that this coalescence-like mode of pinch-off occurs when the initial shape oscillation interferes constructively with the higher harmonics it generates and thus reinforce each other's effects in bringing about bubble break-up. Finally we present numerical results that confirm the weakly nonlinear analysis scenario as well as provide insight into observed shape reversals. They demonstrate that when the oscillations interfere destructively, a qualitativel...

  3. A Curvatureless Boundary--Integral Algorithm and its Applications to Drop Cusping, Merging and Breakup

    NASA Astrophysics Data System (ADS)

    Zinchenko, A. Z.; Rother, M. A.; Davis, R. H.

    1997-11-01

    The existing boundary-integral formulations for Stokes flow past a deformable drop or a system of drops yields a Fredholm second--kind equation for the interfacial velocity. The inhomogeneous term is a single--layer potential including the local surface curvature. The curvature calculation on a triangulated surface is the main source of errors in 3D numerical implementations of the boundary--integral method. We have developed a novel 3D algorithm for interacting deformable drops which requires only normal vectors usually much less sensitive to numerical errors. The method is applicable for any viscosity ratio and also for drops in close approach. The code is particularly helpful in case of flow--induced ``singularities'' (3D tails and 2D cusps) developed in 3D simulations; for a 2D cusp, our transformation to the curvatureless form eliminates the numerically unresolvable contribution of the concentrated capillary force and allows for long--time calculations after the ``singularity'' development. As an application, deformation--induced capture efficiency for two bubbles in gravity--induced motion (previously known only experimentally from M. Manga & H.A. Stone, JFM, 300, 231 (1995)) is computed. It is also shown that the new method alows calculations to proceed much farther than does the conventional formulation in the 3D simiulation of the drop breakup caused by hydrodynamic interactions, so that the volumes of the fragments after breakup can be estimated.

  4. Study of invariant surfaces and their break-up by the Hamilton-Jacobi method

    SciTech Connect

    Warnock, R.L.; Ruth, R.D.

    1986-08-01

    A method is described to compute invariant tori in phase space for calssical non-integrable Hamiltonian systems. Our procedure is to solve the Hamilton-Jacobi equation stated as a system of equations for Fourier coefficients of the generating function. The system is truncated to a finite number of Fourier modes and solved numerically by Newton's method. The resulting canonical transformation serves to reduce greatly the non-integrable part of the Hamiltonian. In examples studied to date the convergence properties of the method are excellent, even near chaotic regions and on the separatrices of isolated broad resonances. We propose a criterion for breakup of invariant surfaces, namely the vanishing of the Jacobian of the canonical transformation to new angle variables. By comparison with results from tracking, we find in an example with two nearly overlapping resonances that this criterion can be implemented with sufficient accuracy to determine critical parameters for the breakup ('transition to chaos') to an accuracy of 5 to 10%.

  5. Applications of optical holography to applied mechanics.

    NASA Technical Reports Server (NTRS)

    Aprahamian, R.

    1972-01-01

    This paper provides a brief summary of applications of optical holography and holographic interferometry to applied solid mechanics. Basic equations commonly used in fringe interpretation are described and used to reduce the data contained on holographic interferograms. A comparison of data obtained holographically with analytical prediction is given wherever possible. Applications contained herein include front surface physics, study of bomb breakup, transverse wave propagation, study of mode shapes of panels at elevated temperatures, nondestructive testing, and vibration analysis.

  6. Self-destabilizing mechanism of a laminar inviscid liquid jet issuing from a circular nozzle.

    PubMed

    Umemura, Akira

    2011-04-01

    A laminar inviscid liquid (typically water) jet issuing from a circular nozzle into otherwise quiescent air disintegrates into droplets periodically at a distance from the nozzle. The Plateau-Rayleigh instability theory and others cannot determine this breakup length because they do not have any logic that determines the initial amplitude of the unstable wave responsible for the breakup. In this paper, a closed spatial evolution solution is derived for a uniformly issued liquid jet by applying a theory that identifies the origin of the unstable wave. This solution describes the self-destabilizing mechanism of the liquid jet in the steady breakup state, showing that the initial amplitude of the unstable wave is determined by the capillary wave with upstream propagating speed that is created by the tip contraction at every breakup. Finally, the developed theory is extended to allow for the self-destabilizing mechanism of a liquid jet issuing from a long nozzle, which initially has a parabolic velocity profile and results in a long breakup length. PMID:21599295

  7. Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies

    SciTech Connect

    Asaturyan, R; Mkrtchyan, H; Navasardyan, T; Tadevosyan, V; Adams, G S; Ahmidouch, A; Angelescu, T; Arrington, J; Asaturyan, A; Baker, O K; Benmouna, N; Bertoncini, C; Blok, H P; Boeglin, W U; Bosted, P E; Breuer, H; Christy, M E; Connell, S H; Cui, Y; Dalton, M M; Danagoulian, S; Day, D; Dunne, J A; Dutta, D; El Khayari, N; Fenker, H C; Frolov, V V; Gan, L; Gaskell, D; Hafidi, K; Hinton, W; Holt, R J; Horn, T; Huber, G M; Hungerford, E; Jiang, X; Jones, M; Joo, K; Kalantarians, N; Kelly, J J; Keppel, C E; Kubarovsky, V; Li, Y; Liang, Y; Mack, D; Malace, S P; Markowitz, P; McGrath, E; McKee, P; Meekins, D G; Mkrtchyan, A; Moziak, B; Niculescu, G; Niculescu, I; Opper, A K; Ostapenko, T; Reimer, P E; Reinhold, J; Roche, J; Rock, S E; Schulte, E; Segbefia, E; Smith, C; Smith, G R; Stoler, P; Tang, L; Ungaro, M; Uzzle, A; Vidakovic, S; Villano, A; Vulcan, W F; Wang, M; Warren, G; Wesselmann, F R; Wojtsekhowski, B; Wood, S A; Xu, C; Yuan, L

    2012-01-11

    A large set of cross sections for semi-inclusive electroproduction of charged pions (?±) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared W2 > 4 GeV2 and range in four-momentum transfer squared 2 < Q2 < 4 (GeV/c)2, and cover a range in the Bjorken scaling variable 0.2 < x < 0.6. The fractional energy of the pions spans a range 0.3 < z < 1, with small transverse momenta with respect to the virtual-photon direction, Pt2 < 0.2 (GeV/c)2. The invariant mass that goes undetected, Mx or W', is in the nucleon resonance region, W' < 2 GeV. The new data conclusively show the onset of quark-hadron duality in this process, and the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark ? pion production mechanisms. The x, z and Pt2 dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for ?+ and ?-) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of d quarks are found to be slightly smaller than for u quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths.

  8. Theoretical and Computational-Fluid-Dynamics Description of the Break-up of Non-wetting Fluids in Pore Constrictions

    NASA Astrophysics Data System (ADS)

    Beresnev, I.; Deng, W.

    2008-12-01

    A stream of a non-wetting fluid passing through pore constrictions tends to disintegrate into smaller beads. Whether the break-up occurs is fully controlled by the geometry of the constriction. The details of the snap- off process are governed by a nonlinear evolution equation that exhibits complex behavior, depending strongly on the initial configuration of the interface between the non-wetting core and the wetting annulus, the slope of the interface, and the thicknesses of the phases. Satellite drops of variable size are typically shed as a result of the break-up process. The quantitative predictions made by the evolution equation are in good agreement with accurate computational-fluid-dynamics simulations. The agreement is reached in the interface shape just before the break-up, the number of satellite drops produced, and the total time to the break-up. In typical scenarios, this time for typical reservoir pore and constriction sizes is a fraction of a millisecond, indicating an almost instant process for all practical purposes.

  9. PHYSICAL REVIEW A 88, 012716 (2013) Breakup of Rydberg-blockaded atom clouds via dipole-dipole interactions

    E-print Network

    Eisfeld, Alexander

    2013-01-01

    the clouds. The dynamics is akin to an ensemble average over systems where only one atom per cloudPHYSICAL REVIEW A 88, 012716 (2013) Breakup of Rydberg-blockaded atom clouds via dipole Rydberg-blockaded atom clouds where each cloud carries initially a coherently shared single excitation. We

  10. Post-breakup tectonics in southeast Brazil from thermochronological data and combined inverse-forward thermal history modeling

    E-print Network

    Paris-Sud XI, Université de

    Cretaceous/Paleogene intrusions are good evidence for post breakup tectono-magmatic activity. To constrain an earlier study for a Late Cretaceous phase of cooling. Around the onshore Taubaté Basin, for a limited number of samples, the first detectable period of cooling occurred during the Early Tertiary

  11. Competition between Collapse and Breakup in Nanometer-Sized Thin Rings Using Molecular Dynamics and Continuum Modeling

    E-print Network

    Kondic, Lou

    Competition between Collapse and Breakup in Nanometer-Sized Thin Rings Using Molecular Dynamics, United States ABSTRACT: We consider nanometer-sized fluid annuli (rings) deposited on a solid substrate of metallic nanodroplets.28,33 Herein, we focus on the nonequilibrium dynamics of melted copper thin rings

  12. PRE AND POST BREAKUP MOVEMENTS AND SPACE USE OF BLACK BEAR FAMILY GROUPS IN CHEROKEE NATIONAL FOREST, TENNESSEE

    Microsoft Academic Search

    ANTHONY P. CLEVENGER; MICHAEL R. PELTON

    The movements and space use of 7 yearling black bears (Ursus americanus) (3 males, 4 females) from 3 family groups were intensively monitored concurrently with 13 adults (6 males, 7 females) in the Cherokee National Forest, Tennessee from February 1983 until December 1983. The timing of family breakup occurred in 2 families between 29 May-5 June, and 22-25 June, respectively.

  13. Deuteron Electrodisintegration in the {ital {Delta}} -Resonance Region

    SciTech Connect

    Pellegrino, A.; Blok, H.P.; Dodge, G.E.; Hesselink, W.H.; Onderwater, C.J.; Starink, R.; Templon, J.A. [Department of Physics and Astronomy, Free University, De Boelelaan 1081, 1081 HV Amsterdam (The Netherlands)] [Department of Physics and Astronomy, Free University, De Boelelaan 1081, 1081 HV Amsterdam (The Netherlands); Pellegrino, A.; Blok, H.P.; Dodge, G.E.; Hesselink, W.H.; Jans, E.; Kasdorp, W.; Lapikas, L.; van Leeuwe, J.J.; Onderwater, C.J.; van der Steenhoven, G.; Starink, R.; Steijger, J.J.; Templon, J.A.; Visschers, J.L. [NIKHEF, P.O. Box 41882, 1009 DB Amsterdam (The Netherlands)] [NIKHEF, P.O. Box 41882, 1009 DB Amsterdam (The Netherlands); Arenhoevel, H.; Wilbois, T.; Wilhelm, P. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)] [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); van Dierendonck, D.; Misiejuk, A.; Willering, H.W.; Yeomans, D.M. [Department of Subatomic Physics, University of Utrecht, P.O. Box 80.000, 3508 TA Utrecht (The Netherlands)] [Department of Subatomic Physics, University of Utrecht, P.O. Box 80.000, 3508 TA Utrecht (The Netherlands); Kalantar-Nayestanaki, N. [KVI, Rijksuniversiteit Groningen, Zernikelaan 25, NL-9747 AA Groningen (The Netherlands)] [KVI, Rijksuniversiteit Groningen, Zernikelaan 25, NL-9747 AA Groningen (The Netherlands); Leidemann, W. [Dipartimento di Fisica, Universita di Trento, I-38050 Povo (Trento) (Italy)] [Dipartimento di Fisica, Universita di Trento, I-38050 Povo (Trento) (Italy)

    1997-05-01

    The differential cross section and the transverse-transverse interference structure function for the reaction {sup 2}H( e,e{sup {prime}}p)n have been determined at an {ital np} invariant mass of 2.16GeV. The data, covering a 40{degree} range in the proton emission angle, indicate that {Delta} excitation and subsequent {ital N}{Delta} interaction is the dominant reaction mechanism. Calculations performed within an {ital N}{Delta} coupled-channel approach reproduce the cross section data, but underestimate the f{sub TT} results by 30 to 40 percent. {copyright} {ital 1997} {ital The American Physical Society}

  14. Post-breakup Basin Evolution along the South-Atlantic Margins in Brazil and Angola/Namibia

    NASA Astrophysics Data System (ADS)

    Kukla, P. A.; Strozyk, F.; Back, S.

    2013-12-01

    The post-breakup tectono-stratigraphic evolution of large offshore basins along the South American and African continental margins record strongly varying post-rift sedimentary successions. The northernmost segment of the South Atlantic rift and salt basins is characterized by a pronounced asymmetry, with the Brazilian margin comprising narrower and deeper rift basins with less salt in comparison to the Congo-Gabon conjugate margin. Another important observation is that multiple phases of uplift and subsidence are recorded after the break-up of the southern South Atlantic on both sides of the Florianopolis-Walvis Ridge volcanic complex, features that are regarded as atypical when compared to published examples of other post-breakup margin successions. A regional comparison based on tectonic-stratigraphic analysis of selected seismic transects between the large basins offshore southern Brazil (Espirito Santo Basin, Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Lower Congo Basin, Kwanza Basin, Namibe Basin, Walvis Basin) provides a comprehensive basin-to-basin documentation of the key geological parameters controlling ocean and continental margin development. This comparison includes the margin configuration, subsidence development through time, sediment influx and storage patterns, type of basin fill (e.g. salt vs. non-salt systems; carbonate-rich vs. clastics-dominated systems) and finally major tectonic and magmatic events. Data from the salt basins indicate that salt-related tectonic deformation is amongst the prime controls for the non-uniform post-rift margin development. The diversity in the stratigraphic architecture of the conjugate margins offshore southern Brazil, Namibia and Angola reflects variations in the interplay of a number of controlling factors, of which the most important are (a) the structural configuration of each margin segment at the time of break-up, (b) the post break-up subsidence history of the respective margin segment, (c) variations in the type, quantity and distribution of margin sediment, and (d) sea-level changes.

  15. Pleistocene ice streaming and marine-margin breakup revealed by multibeam bathymetry data: The Minch, NW Scotland

    NASA Astrophysics Data System (ADS)

    Bradwell, Tom; Stoker, Martyn

    2013-04-01

    Extensive dynamically driven breakup and rapid ice loss is currently ongoing at tidewater margins of the Greenland and Antarctica Ice Sheets, yet few good analogues from the palaeo-record exist. Using ca. 55,000 km2 of echosounder bathymetry data from the continental shelf around NW Scotland we have mapped submarine glacial landforms relating to an ice sheet that covered much of the continental shelf during the Late Pleistocene and had extensive tidewater margins. Focusing on new multibeam bathymetry from the inner part of the shelf (The Minch), we present seabed geomorphological evidence showing breakup of a large marine portion of a palaeo-ice stream within the British-Irish Ice Sheet. Clearly defined, well preserved glacial lineations, elongate bedforms and seabed drumlins indicate former fast flow of a grounded palaeo-ice stream in a northerly direction in The Minch. In addition, the absence of moraines and grounding-line features deposited during ice sheet retreat and the abundance of large overprinted iceberg scours collectively indicate rapid marine-margin breakup by flotation and thinning. We suggest that this marine-margin breakup event was probably driven by unstable ice sheet retreat into shoreward deepening water and was inextricably linked with the abrupt demise of The Minch palaeo-ice stream. Importantly, this new evidence indicates that potentially large areas of the ice sheet margin were floating at times during British-Irish Ice Sheet retreat on the continental shelf. Ongoing work is seeking to date the timing of ice sheet breakup and ice stream demise in northern Scotland.

  16. Structure and rheology of the lithosphere below southeastern margin of India and Sri Lanka, and its conjugate segment of the east Antarctica: Implications on early breakup history and margin formation

    NASA Astrophysics Data System (ADS)

    Rao Gangumalla, Srinivasa; Radhakrishna, Munukutla

    2014-05-01

    The eastern continental margin of India has evolved as a consequence of rifting and breakup between India and east Antarctica during the early Cretaceous. Plate reconstruction models for the breakup of eastern Gondwanaland by many earlier workers have unambiguously placed the southeast margin of Sri Lanka and India together as a conjugate segment with the east Antarctica margin that extends from Gunnerus Ridge in the west to western Enderby basin in the east. In this study, we present results of integrated analysis of gravity, geoid, magnetic and seismic data from these two conjugate portions in order to examine the lithosphere structure and early seafloor spreading, style of breakup, continent-ocean boundary (COB) and rheological characteristics at these margins. The interpreted COB lies at a distance of 55-140 km on the side of southeast margin of Sri Lanka and India, whereas, it lies at a distance of 190-550 km on the side of east Antarctica margin. The seismic profiles and the constrained potential field models across these two segments do not show the existence of seaward dipping reflector sequences or magmatic underplating suggesting that these segments have not encountered major magmatic activity. While, significant crustal thinning/stretching is observed at the east Antarctic margin, the Cauvery offshore had experienced limited stretching with faulted Moho interface. Further, the conspicuous residual geoid low in the Cauvery offshore basin is inferred to be due to a continental crustal block. The modelled Lithosphere-Astenosphere Boundary (LAB) in these two margins is located around 110-120 km depth with slightly thicker lithosphere at the east Antarctica margin. In addition, the interpretation of magnetic anomalies provided structure of the oceanic crust generated through seafloor spreading processes with age and magnetization data constrained from the identified magnetic anomalies in the respective margins. Using the Bouguer coherence method, we computed spatial variations in effective elastic thickness (Te) at these margin segments. The estimated Te values at the Indian margin ranges between 5-8 km in the southeast of Sri Lanka to around 10-12 km in the Cauvery offshore which decrease further north to < 5 km in the Cauvery-Palar basin. Along the east Antarctic margin, the Te values ranges between 5-10 km in the Gunnerus ridge region, 35-40 km in the western Enderby basin which decrease further towards the central Enderby basin up to 20 km. In this study, the above results have been analyzed in terms of early breakup mechanism and subsequent evolution of these two conjugate segments.

  17. Plastic scintillator detectors for the study of transfer and breakup reactions at intermediate energies

    SciTech Connect

    Schmidt, H.R.; Bantel, M.; Chan, Y.D.; Gazes, S.M.; Kamermans, R.; Albiston, C.; Wald, S.; Stokstad, R.G.

    1984-10-01

    The detection of light particles associated with projectile like fragments can be used to separate transfer and breakup reactions provided the detectors cover a large solid angle. Three detection systems are described: (1) a ..pi.. detector in the shape of a cube, 20 cm on a side, (2) a X-Y position sensitive ..delta..E-E detector having an area of 20 x 20 cm/sup 2/, and (3) a multi-element detector consisting of eight position sensitive strips. The latter two detectors are of the phoswich type having the thin element of NE102 (tau = 2.5 ns) and the thick element of NE115 (tau = 225 ns). The performance characteristics of the three detectors are described. 6 references, 13 figures.

  18. Breakup of the Larsen B Ice Shelf triggered by chain reaction drainage of supraglacial lakes

    NASA Astrophysics Data System (ADS)

    Banwell, Alison F.; MacAyeal, Douglas R.; Sergienko, Olga V.

    2013-11-01

    The explosive disintegration of the Larsen B Ice Shelf poses two unresolved questions: What process (1) set a horizontal fracture spacing sufficiently small to predispose the subsequent ice shelf fragments to capsize and (2) synchronized the widespread drainage of >2750 supraglacial meltwater lakes observed in the days prior to break up? We answer both questions through analysis of the ice shelf's elastic flexure response to the supraglacial lakes on the ice shelf prior to break up. By expanding the previously articulated role of lakes beyond mere water reservoirs supporting hydrofracture, we show that lake-induced flexural stresses produce a fracture network with appropriate horizontal spacing to induce capsize-driven breakup. The analysis of flexural stresses suggests that drainage of a single lake can cause neighboring lakes to drain, which, in turn, causes farther removed lakes to drain. Such self-stimulating behavior can account for the sudden, widespread appearance of a fracture system capable of driving explosive break up.

  19. Analytical relations for long-droplet breakup in asymmetric T junctions

    NASA Astrophysics Data System (ADS)

    Bedram, Ahmad; Moosavi, Ali; Hannani, Siamak Kazemzadeh

    2015-05-01

    We develop accurate analytical relations for the droplet volume ratio, droplet length during breakup process, and pressure drop of asymmetric T junctions with a valve in each of the branches for producing unequal-sized droplets. An important advantage of this system is that after manufacturing the system, the size of the generated droplets can be changed simply by adjusting the valves. The results indicate that if the valve ratio is smaller than 0.65, the system enters a nonbreakup regime. Also the pressure drop does not depend on the time and decreases by increasing the valve ratio, namely, opening the degree of valve 1 to valve 2. In addition, the results reveal that by decreasing (increasing) the valve ratio, the droplet length of branch 1 decreases (increases) and the droplet length of branch 2 increases (decreases) linearly while the whole length of the droplet remains unchanged.

  20. Saturation of stimulated Brillouin scattering by ion acoustic wave bowing and breakup

    NASA Astrophysics Data System (ADS)

    Yin, Lin; Albright, Brian; Montgomery, David; Bergen, Ben; Bowers, Kevin

    2014-10-01

    In laser-driven fusion and high-energy-density physics experiments, two crossing laser beams can transfer energy between one another via stimulated Brillouin scattering (SBS) involving the two laser beams and an ion acoustic wave (IAW). Obtaining a physics-based understanding of the nonlinear saturation of cross-beam energy transfer is important to low-mode asymmetry control in ICF implosions. In this work, nonlinear saturation of SBS in speckled laser beams is examined in the kinetic regime using 2D and 3D particle-in-cell simulations. Rapid SBS saturation is found to be caused by IAW bowing from trapped particle nonlinear frequency shift and IAW break up in the direction transverse to the laser. Both processes can lead to rapid loss of trapped ions in regions of small transverse extent during IAW bowing and breakup and dissipation of wave energy.