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Sample records for atomic collision physics

  1. Sixteenth International Conference on the physics of electronic and atomic collisions

    SciTech Connect

    Dalgarno, A.; Freund, R.S.; Lubell, M.S.; Lucatorto, T.B.

    1989-01-01

    This report contains abstracts of papers on the following topics: photons, electron-atom collisions; electron-molecule collisions; electron-ion collisions; collisions involving exotic species; ion- atom collisions, ion-molecule or atom-molecule collisions; atom-atom collisions; ion-ion collisions; collisions involving rydberg atoms; field assisted collisions; collisions involving clusters and collisions involving condensed matter.

  2. Neutrino-atom collisions

    NASA Astrophysics Data System (ADS)

    Kouzakov, Konstantin A.; Studenikin, Alexander I.

    2016-05-01

    Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.

  3. Atomic cluster collisions

    NASA Astrophysics Data System (ADS)

    Korol, Andrey V.; Solov'yov, Andrey

    2013-01-01

    Atomic cluster collisions are a field of rapidly emerging research interest by both experimentalists and theorists. The international symposium on atomic cluster collisions (ISSAC) is the premier forum to present cutting-edge research in this field. It was established in 2003 and the most recent conference was held in Berlin, Germany in July of 2011. This Topical Issue presents original research results from some of the participants, who attended this conference. This issues specifically focuses on two research areas, namely Clusters and Fullerenes in External Fields and Nanoscale Insights in Radiation Biodamage.

  4. Photonic, Electronic and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Fainstein, Pablo D.; Lima, Marco Aurelio P.; Miraglia, Jorge E.; Montenegro, Eduardo C.; Rivarola, Roberto D.

    2006-11-01

    -coincidence technique / T. Kaneyasu, T. Azuma and K. Okuno. Recent developments in proton-transfer-reaction mass spectrometry / A. Wisthaler ... [et al.]. Interferences in electron emission from H[symbol] induced by fast ions / N. Stolterfoht. Atomic realization of the young single electron interference process in individual autoionization collisions / R. O. Barrachina and M. Šitnik. Multiple ionization processes related to irradiation of biological tissue / M. E. Galassi ... [et al.]. Atom-diatom collisions at cold and ultra-cold temperatures / F. D. Colavecchia, G. A. Parker and R. T. Pack. Interactions of ions with hydrogen atoms / A. Luca, G. Borodi and D. Gerlich. Analysis of all structures in the elastic and charge transfer cross sections for proton-hydrogen collisions in the range of 10[symbol]-10øeV / P. S. Krstić ... [et al.]. Ab-initio ion-atom collision calculations for many-electron systems / J. Anton and B. Fricke. Fully differential studies on single ionization of helium by slow proton impact / A. Hasan ... [et al.]. Dipole polarization effects on highly-charged-ion-atom electron capture / C. C. Havener ... [et al.]. Proton-, antiproton-, and photon-he collisions in the context of ultra fast processes / T. Morishita ... [et al.]. Impact parameter dependent charge exchange studies with channeled heavy ions / D. Dauvergne ... [et al.]. Crystal assisted atomic physics experiments using heavy ions / K. Komaki -- Collisions involving clusters and surfaces. Structure and dynamics of Van der Waal complexes: from triatomic to medium size clusters / G. Delgado Barrio ... [et al.]. Evaporation, fission and multifragmentation processes of multicharged C[symbol] ions versus excitation energies / S. Martin ... [et al.]. Fragmentation of collisionally excited fullerenes / M. Alcami, S. Diaz-Tendero and F. Martín. Lifetimes of C[symbol] and C[symbol] dianions in a storage ring / S. Tomita ... [et al.]. Clusters and clusters of clusters in collisions / B. Manil ... [et al

  5. Electron-Atom Collisions in Gases

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2013-01-01

    Electron-atom collisions in gases are an aspect of atomic physics. Three experiments in this field employing a thyratron are described: (i) the Ramsauer-Townsend effect, (ii) the excitation and ionization potentials of xenon and (iii) the ion-electron recombination after interrupting the electric discharge.

  6. Atomic physics

    SciTech Connect

    Livingston, A.E.; Kukla, K.; Cheng, S.

    1995-08-01

    In a collaboration with the Atomic Physics group at Argonne and the University of Toledo, the Atomic Physics group at the University of Notre Dame is measuring the fine structure transition energies in highly-charged lithium-like and helium-like ions using beam-foil spectroscopy. Precise measurements of 2s-2p transition energies in simple (few-electron) atomic systems provide stringent tests of several classes of current atomic- structure calculations. Analyses of measurements in helium-like Ar{sup 16+} have been completed, and the results submitted for publication. A current goal is to measure the 1s2s{sup 3}S{sub 1} - 1s2p{sup 3}P{sub 0} transition wavelength in helium-like Ni{sup 26+}. Measurements of the 1s2s{sup 2}S{sub 1/2} - 1s2p{sup 2}P{sub 1/2,3/2} transition wavelengths in lithium-like Kr{sup 33+} is planned. Wavelength and lifetime measurements in copper-like U{sup 63+} are also expected to be initiated. The group is also participating in measurements of forbidden transitions in helium-like ions. A measurement of the lifetime of the 1s2s{sup 3}S{sub 1} state in Kr{sup 34+} was published recently. In a collaboration including P. Mokler of GSI, Darmstadt, measurements have been made of the spectral distribution of the 2E1 decay continuum in helium-like Kr{sup 34+}. Initial results have been reported and further measurements are planned.

  7. Atom trap loss, elastic collisions, and technology

    NASA Astrophysics Data System (ADS)

    Booth, James

    2012-10-01

    The study of collisions and scattering has been one of the most productive approaches for modern physics, illuminating the fundamental structure of crystals, surfaces, atoms, and sub-atomic particles. In the field of cold atoms, this is no less true: studies of cold atom collisions were essential to the production of quantum degenerate matter, the formation of cold molecules, and so on. Over the past few years it has been my delight to investigate elastic collisions between cold atoms trapped in either a magneto-optical trap (MOT) or a magnetic trap with hot, background gas in the vacuum environment through the measurement of the loss of atoms from the trap. Motivated by the goal of creating cold atom-based technology, we are deciphering what the trapped atoms are communicating about their environment through the observed loss rate. These measurements have the advantages of being straightforward to implement and they provide information about the underlying, fundamental inter-atomic processes. In this talk I will present some of our recent work, including the observation of the trap depth dependence on loss rate for argon-rubidium collisions. The data follow the computed loss rate curve based on the long-range Van der Waals interaction between the two species. The implications of these findings are exciting: trap depths can be determined from the trap loss measurement under controlled background density conditions; observation of trap loss rate in comparison to models for elastic, inelastic, and chemical processes can lead to improved understanding and characterization of these fundamental interactions; finally the marriage of cold atoms with collision modeling offers the promise of creating a novel pressure sensor and pressure standard for the high and ultra-high vacuum regime.

  8. Ion-Atom Cold Collisions and Atomic Clocks

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Maleki, Lute; Tjoelker, Robert L.

    1997-01-01

    Collisions between ultracold neutral atoms have for some time been the subject of investigation, initially with hydrogen and more recently with laser cooled alkali atoms. Advances in laser cooling and trapping of neutral atoms in a Magneto-Optic Trap (MOT) have made cold atoms available as the starting point for many laser cooled atomic physics investigations. The most spectacularly successful of these, the observation of Bose-Einstein Condensation (BEC) in a dilute ultra-cold spin polarized atomic vapor, has accelerated the study of cold collisions. Experimental and theoretical studies of BEC and the long range interaction between cold alkali atoms is at the boundary of atomic and low temperature physics. Such studies have been difficult and would not have been possible without the development and advancement of laser cooling and trapping of neutral atoms. By contrast, ion-atom interactions at low temperature, also very difficult to study prior to modern day laser cooling, have remained largely unexplored. But now, many laboratories worldwide have almost routine access to cold neutral atoms. The combined technologies of ion trapping, together with laser cooling of neutrals has made these studies experimentally feasible and several very important, novel applications might come out of such investigations . This paper is an investigation of ion-atom interactions in the cold and ultra-cold temperature regime. Some of the collisional ion-atom interactions present at room temperature are very much reduced in the low temperature regime. Reaction rates for charge transfer between unlike atoms, A + B(+) approaches A(+) + B, are expected to fall rapidly with temperature, approximately as T(sup 5/2). Thus, cold mixtures of atoms and ions are expected to coexist for very long times, unlike room temperature mixtures of the same ion-atom combination. Thus, it seems feasible to cool ions via collisions with laser cooled atoms. Many of the conventional collisional interactions

  9. Path Integral Approach to Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Harris, Allison

    2016-09-01

    The Path Integral technique is an alternative formulation of quantum mechanics that is based on a Lagrangian approach. In its exact form, it is completely equivalent to the Hamiltonian-based Schrödinger equation approach. Developed by Feynman in the 1940's, following inspiration from Dirac, the path integral approach has been widely used in high energy physics, quantum field theory, and statistical mechanics. However, only in limited cases has the path integral approach been applied to quantum mechanical few-body scattering. We present a theoretical and computational development of the path integral method for use in the study of atomic collisions. Preliminary results are presented for some simple systems. Ultimately, this approach will be applied to few-body ion-atom collisions. Work supported by NSF grant PHY-1505217.

  10. The problems of solar-terrestrial coupling and new processes introduced to the physics of the ionosphere from the physics of atomic collisions

    NASA Astrophysics Data System (ADS)

    Avakyan, Sergei

    2010-05-01

    Further progress in research of solar-terrestrial coupling requires better understanding of solar variability influence on the ionosphere. The most powerful manifestations of solar variability are solar flares and geomagnetic storms. During a flare EUV/X-ray irradiations are completely absorbed in the ionosphere producing SID. During geomagnetic storms precipitations of electrons with energy of several keV (and to a lesser extent protons precipitations) from radiation belts and geomagnetosphere produce additional ionization and low latitude auroras. Considering the physics of ionosphere during the last several decades we have been taking into account three novel processes well known in the physics of atomic collisions. These are Auger effect [S. V. Avakyan, The consideration of Auger processes in the upper atmosphere of Earth. In Abstracts of paper presented at the Tenth scien. and techn. Conf. of young specialists of S.I. Vavilov State Optical Institute, 1974, 29-31.], multiple photoionization of upper, valence shell [S.V. Avakyan, The source of O++ ions in the upper atmosphere, 1979, Cosmic Res, 17, 942 - 943] and Rydberg excitation of all the components of upper atmosphere [S.V. Avakyan, The new factor in the physics of solar - terrestrial relations - Rydberg atomic and molecules states. Conf. on Physics of solar-terrestrial relationships, 1994, Almaty, 3 - 5]. In the present paper the results of bringing these new processes in the ionospheric physics are discussed and also its possible role in the physics of solar-terrestrial coupling is considered. Involving these processes to the model estimations allowed us for the first time to come to the following important conclusions: - Auger electrons play the determinant role at the formation of energy spectrum of photoelectrons and secondary auroral electrons at the range above 150 eV; - double photoionization of the outer shell of the oxygen atom (by a single photon) plays a dominant role in the formation of

  11. Storage rings for investigation of ion-atom collisions

    SciTech Connect

    Schuch, R.

    1987-08-01

    In this survey, we give a brief description of synchrotron storage rings for heavy ions, and examples for their use in ion-atom collision physics. The compression of the phase space distribution of the ions by electron cooling, and the gain factors of in-ring experiments compared to single-pass experiments are explained. Some examples of a new generation of ion-atom collision experiments which may become feasible with storage rings are given. These include the studies of angular differential single- and double-electron capture cross sections, the production of slow highly charged recoil ions, and atomic collision processes using decelerated and crossed beam. 30 refs.

  12. KAULAKYS: Inelastic collisions between hydrogen atoms and Rydberg atoms

    NASA Astrophysics Data System (ADS)

    Barklem, Paul S.

    2017-01-01

    KAULAKYS calculates cross sections and rate coefficients for inelastic collisions between Rydberg atoms and hydrogen atoms according to the free electron model of Kaulakys (1986, 1991). It is written in IDL and requires the code MSWAVEF (ascl:1701.006) to calculate momentum-space wavefunctions. KAULAKYS can be easily adapted to collisions with perturbers other than hydrogen atoms by providing the appropriate scattering amplitudes.

  13. Advances in atomic physics

    PubMed Central

    El-Sherbini, Tharwat M.

    2013-01-01

    In this review article, important developments in the field of atomic physics are highlighted and linked to research works the author was involved in himself as a leader of the Cairo University – Atomic Physics Group. Starting from the late 1960s – when the author first engaged in research – an overview is provided of the milestones in the fascinating landscape of atomic physics. PMID:26425356

  14. Time ordering in atomic collisions

    NASA Astrophysics Data System (ADS)

    McGuire, J. H.; Godunov, A. L.; Shakov, Kh Kh; Kaplan, L.; Burin, A.; Uskov, D.

    2007-06-01

    Time ordering constrains interactions to occur in increasing (or decreasing) order. This places a constraint on the time evolution of the system and can lead to correlations in time of different particles in a few/many body system. Unlike overall time reversal, time ordering is not a conserved symmetry of the atomic system. A number of examples of observable effects of time ordering are presented. A convenient way to describe time ordering is to define the limit of no time ordering by replacing the instantaneous interaction by its time average. This is similar to the way in which spatial correlation is defined. Like spatial correlation, time ordering is usually formulated in the interaction representation. The effects of time ordering can differ in different representations. In energy space, conjugate to time space, time ordering is imposed as the i ɛ term in the Greens' function that corresponds to an initial condition (usually incoming plane waves and outgoing scattered waves). This permits off-energy-shell (energy non- conserving) fluctuations during the collision consistent with the Uncertainty Principle.

  15. Multiple-electron processes in fast ion-atom collisions

    SciTech Connect

    Schlachter, A.S.

    1989-03-01

    Research in atomic physics at the Lawrence Berkeley Laboratory Super-HILAC and Bevalac accelerators on multiple-electron processes in fast ion-atom collisions is described. Experiments have studied various aspects of the charge-transfer, ionization, and excitation processes. Examples of processes in which electron correlation plays a role are resonant transfer and excitation and Auger-electron emission. Processes in which electron behavior can generally be described as uncorrelated include ionization and charge transfer in high-energy ion-atom collisions. A variety of experiments and results for energies from 1 MeV/u to 420 MeV/u are presented. 20 refs., 15 figs.

  16. PREFACE: XXV International Conference on Photonic, Electronic and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Becker, Uwe; Moshammer, Robert; Mokler, Paul; Ullrich, Joachim

    2007-07-01

    The XXVth ICPEAC in Freiburg marked a notable anniversary in collision physics: half a century ago the first conference in the series of International Conferences on the Physics of Electronic and Atomic Collisions (ICPEAC) was held in New York (1958). Since then, the development of electronic and atomic collision physics has seen tremendous progress. Starting during a time, when this field was regarded as somehow out-of-date, certainly not being in the main stream compared to particle and high-energy physics, it has expanded in a rather exceptional and unforeseen way. Over the years the original scope on electronic, atomic and heavy-ion collision physics was extended substantially to include upcoming expanding fields like synchrotron-radiation and strong-field laser-based atomic and molecular physics giving rise to a change of name to 'Photonic', Electronic and Atomic Collisions (ICPEAC) being used for the first time for the ICPEAC in Santa Fee in 2001. Nowadays, the ICPEAC has opened its agenda even more widely to other fields of atomic and molecular physics, such as interactions with clusters, bio-molecules and surfaces, to cold collisions, coherent control, femto- and attosecond physics and, with the Freiburg conference, to the application of free-electron lasers in the vacuum ultraviolet and soft x-ray regime, a field of potentially huge future impact in essentially all areas of science. In this larger context the XXVth ICPEAC in Freiburg with more than 800 participants set new standards. Representatives from all fields of Atomic, Molecular and Photon-based science came together and had very fruitful, inter-disciplinary discussions. This new forum of collision-based AMP physics will serve as a showcase example of future conferences, bridging not only the gap between different fields of collision physics but also, equally important, between different continents and cultures. The next ICPEAC is going to take place in Kalamazoo in North America, the one after that

  17. Reactive collisions of atoms with diatomic molecules

    NASA Astrophysics Data System (ADS)

    Wolniewicz, L.; Hinze, Juergen; Alijah, Alexander

    1993-08-01

    The theory of the reactive collision of an atom with a diatomic molecule is formulated in 'democratic' hyperspherical coordinates. An adiabatic ansatz is used to separate the distance coordinate from the angular coordinates. The angular eigenvalue problem is solved, using the hyperspherical harmonics as basis functions, while the R-matrix propagation method is used to integrate the resulting coupled equations along the distance coordinate. As an example, reactive collision probabilities for H + H2 are computed, using the Porter-Karplus surface. The symmetry requirements, when dealing with three identical Fermions in the collision, are considered explicitly.

  18. Benchmark Calculations of Atomic Collision Processes

    NASA Astrophysics Data System (ADS)

    Bartschat, Klaus

    2012-02-01

    The rapid development of computational resources has resulted in enormous improvements in the accuracy of numerical calculations of atomic collision processes. This talk will concentrate on recent advances in the computational treatment of charged-particle and intense short-pulse laser interactions with atoms, ions, and small molecules. Examples include electron collisions with heavy complex targets that are of significant importance in many modelling applications in plasma and astrophysics, fundamental studies of highly correlated 4-body Coulomb processes such as simultaneous ionization with excitation, and the accurate solution of the time-dependent Schr"odinger equation in the presence of intense femto/attosecond laser fields, which paves the way for quantum dynamic imaging and coherent control.

  19. Atom-atom inelastic collisions and three-body atomic recombination in weakly ionized argon plasmas

    NASA Technical Reports Server (NTRS)

    Braun, C. G.; Kunc, J. A.

    1989-01-01

    A stationary collisional-radiative model including both inelastic electron-atom and atom-atom collisions is used to examine nonequilibrium weakly ionized argon plasmas with atomic densities 10 to the 16th to 10 to the 20th/cu cm, temperatures below 6000 K, and with different degrees of radiation trapping. It is shown that three-body atomic recombination becomes important at high particle densities. Comparison is made between the present approach and Thomson's theory for atomic recombination.

  20. Transition state in atomic physics

    NASA Astrophysics Data System (ADS)

    Jaffé, Charles; Farrelly, David; Uzer, T.

    1999-11-01

    The transition state is fundamental to modern theories of reaction dynamics: essentially, the transition state is a structure in phase space that all reactive trajectories must cross. While transition-state theory (TST) has been used mainly in chemical physics, it is possible to apply the theory to considerable advantage in any collision problem that involves some form of reaction. Of special interest are systems in which chaotic scattering or half-scattering occurs such as the ionization of Rydberg atoms in external fields. In this paper the ionization dynamics of a hydrogen atom in crossed electric and magnetic fields are shown to possess a transition state: We compute the periodic orbit dividing surface (PODS) which is found not to be a dividing surface when projected into configuration space. Although the possibility of a PODS occurring in phase space rather than configuration space has been recognized before, to our knowledge this is the first actual example: its origin is traced directly to the presence of velocity-dependent terms in the Hamiltonian. Our findings establish TST as the method of choice for understanding ionization of Rydberg atoms in the presence of velocity-dependent forces. To demonstrate this TST is used to (i) uncover a multiple-scattering mechanism for ionization and (ii) compute ionization rates. In the process we also develop a method of computing surfaces of section that uses periodic orbits to define the surface, and examine the fractal nature of the dynamics.

  1. Local density probing of atomic gas via cold Li-Ca+ inelastic collisions in an atom-ion hybrid system

    NASA Astrophysics Data System (ADS)

    Saito, Ryoichi; Haze, Shinsuke; Fujinaga, Munekazu; Kyuno, Kazuki; Mukaiyama, Takashi

    2015-05-01

    Ultracold atoms in a harmonic trap inevitably has an inhomogeneous density distribution, which makes an atomic gas an ensemble of atoms in different physical phases. Recent technical advances in the determination of local physical quantities in an atomic gas overcome this complexity and make it possible to directly compare experimental results with many-body theories of a homogeneous atomic gas. A laser-cooled ion can be used as a high-spatial resolution probe of physical quantities of an atomic gas. The spatial spread of an ion can be reduced to sub-microns, which is even small enough for the application of the local probe of atoms in optical lattices. In our experiment, we constructed Li and Ca+ ultracold hybrid system and observed inelastic collisions as a loss of ions. The inelastic collision is confirmed to be a charge-exchange process, whose rate depends linearly on the local atomic density. From the measurement of the rate of the charge-exchange, we can reproduce an atomic density profile. This is an important step toward a local probe of physical quantities of atoms with cold ions. In this presentation, we report on the observation of charge-exchange collisions between Li atom and Ca+ ions, and discuss the feasibility of the ions as a probe of the atoms.

  2. Ionization Phenomena in Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Deveney, Edward Francis

    Two many-electron ion-atom collision systems are used to investigate atomic and molecular structure and collisional interactions. Electrons emitted from MeV/u C^{3+} projectile target -atom collisions were measured with a high-resolution position -sensitive electron spectrometer at Oak Ridge National Laboratory. The electrons are predominantly ionized by direct projectile -target interactions or autoionizing (AI) from doubly excited AI levels of the ion which were excited in the collision. The energy dependence of directly scattered target electrons, binary-encounter electrons (BEE), is investigated and compared with theory. AI levels of the projectile 1s to nl single electron excited series, (1s2snl) n = 2,3,4,....infty, including the series limit are identified uniquely using energy level calculations. Original Auger yield calculations using a code by Cowan were used to discover a 1/{n^3} scaling in intensities of Auger peaks in the aforementioned series. This is explained using scattering theory. A nonstatistical population of the terms in the (1s2s2l) configuration was identified and investigated as a function of the beam energy and for four different target atoms. Two electron excited configurations are identified and investigated. The angular distribution of a correlated transfer and excitation AI state is measured and compared to theory. The final scattered charge state distributions of Kr^ {n+}, n = 1, 2, 3, 4, 5, projectiles are measured following collisions with Kr targets in the Van de Graaff Laboratory here at The University of Connecticut. Average scattered charge states as high as 12 are observed. It appears that these electrons are ionized during the lifetime of the quasimolecular state but a complete picture of the ionization mechanism(s) is not known. Calculations using a statistical model of ionization, modified in several ways, are compared with the experimental results to see if it is possible to isolate whether or not the electrons originate

  3. Atomic physics with highly charged ions. Progress report

    SciTech Connect

    Richard, P.

    1994-08-01

    The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project, ``Atomic Physics with Highly Charged Ions,`` speaks to these points. The experimental work in the past few years has divided into collisions at high velocity using the primary beams from the tandem and LINAC accelerators and collisions at low velocity using the CRYEBIS facility. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x rays and Auger electrons. Brief research summaries are given for the following: (1) electron production in ion-atom collisions; (2) role of electron-electron interactions in two-electron processes; (3) multi-electron processes; (4) collisions with excited, aligned, Rydberg targets; (5) ion-ion collisions; (6) ion-molecule collisions; (7) ion-atom collision theory; and (8) ion-surface interactions.

  4. ISOTROPIC INELASTIC COLLISIONS IN A MULTITERM ATOM WITH HYPERFINE STRUCTURE

    SciTech Connect

    Belluzzi, Luca; Landi Degl’Innocenti, Egidio; Bueno, Javier Trujillo

    2015-10-10

    A correct modeling of the scattering polarization profiles observed in some spectral lines of diagnostic interest, the sodium doublet being one of the most important examples, requires taking hyperfine structure (HFS) and quantum interference between different J-levels into account. An atomic model suitable for taking these physical ingredients into account is the so-called multiterm atom with HFS. In this work, we introduce and study the transfer and relaxation rates due to isotropic inelastic collisions with electrons, which enter the statistical equilibrium equations (SEE) for the atomic density matrix of this atomic model. Under the hypothesis that the electron–atom interaction is described by a dipolar operator, we provide useful relations between the rates describing the transfer and relaxation of quantum interference between different levels (whose numerical values are in most cases unknown) and the usual rates for the atomic level populations, for which experimental data and/or approximate theoretical expressions are generally available. For the particular case of a two-term atom with HFS, we present an analytical solution of the SEE for the spherical statistical tensors of the upper term, including both radiative and collisional processes, and we derive the expression of the emission coefficient in the four Stokes parameters. Finally, an illustrative application to the Na i D{sub 1} and D{sub 2} lines is presented.

  5. Isotropic Inelastic Collisions in a Multiterm Atom with Hyperfine Structure

    NASA Astrophysics Data System (ADS)

    Belluzzi, Luca; Landi Degl'Innocenti, Egidio; Trujillo Bueno, Javier

    2015-10-01

    A correct modeling of the scattering polarization profiles observed in some spectral lines of diagnostic interest, the sodium doublet being one of the most important examples, requires taking hyperfine structure (HFS) and quantum interference between different J-levels into account. An atomic model suitable for taking these physical ingredients into account is the so-called multiterm atom with HFS. In this work, we introduce and study the transfer and relaxation rates due to isotropic inelastic collisions with electrons, which enter the statistical equilibrium equations (SEE) for the atomic density matrix of this atomic model. Under the hypothesis that the electron-atom interaction is described by a dipolar operator, we provide useful relations between the rates describing the transfer and relaxation of quantum interference between different levels (whose numerical values are in most cases unknown) and the usual rates for the atomic level populations, for which experimental data and/or approximate theoretical expressions are generally available. For the particular case of a two-term atom with HFS, we present an analytical solution of the SEE for the spherical statistical tensors of the upper term, including both radiative and collisional processes, and we derive the expression of the emission coefficient in the four Stokes parameters. Finally, an illustrative application to the Na i D1 and D2 lines is presented.

  6. Contemporary Aspects of Atomic Physics

    ERIC Educational Resources Information Center

    Knott, R. G. A.

    1972-01-01

    The approach generally used in writing undergraduate textbooks on Atomic and Nuclear Physics presents this branch as historical in nature. Describes the concepts of astrophysics, plasma physics and spectroscopy as contemporary and intriguing for modern scientists. (PS)

  7. Many-Body Atomic Physics

    NASA Astrophysics Data System (ADS)

    Boyle, J. J.; Pindzola, M. S.

    1998-09-01

    Preface; Contributors; Introduction; Part I. Atomic Structure: 1. Development of atomic many-body theory Ingvar Lindgren; 2. Relativistic MBPT for highly charged ions W. R. Johnson; 3. Parity nonconservation in atoms S. A. Blundell, W. R. Johnson, and J. Sapirstein; Part II. Photoionization of Atoms: 4. Single photoionization processes J. J. Boyle, and M. D. Kutzner; 5. Photoionization dominated by double excitation T. N. Chang; 6. Direct double photoionization in atoms Z. W. Liu; 7. Photoelectron angular distributions Steven T. Manson; Part III. A. Atomic Scattering - General Considerations: 8. The many-body approach to electron-atom collisions M. Ya Amusia; 9. Theoretical aspects of electron impact ionization P. L. Altick; Part III. B. Atomic Scattering - Low-Order Applications: 10. Perturbation series methods D. H. Madison; 11. Target dependence of the triply differential cross section Cheng Pan and Anthony F. Starace; 12. Overview of Thomas processes for fast mass transfer J. H. McGuire, Jack C. Straton and T. Ishihara; Part III. C. Atomic Scattering - All-Order Applications: 13. R-matrix Theory: Some Recent Applications Philip G. Burke: 14. Electron scattering: application of Dirac R-matrix theory Wasantha Wijesundera, Ian Grant and Patrick Norrington; 15. Close coupling and distorted-wave theory D. C. Griffin and M. S. Pindzola; Appendix: Units and notation; References; Index.

  8. Many-Body Atomic Physics

    NASA Astrophysics Data System (ADS)

    Boyle, J. J.; Pindzola, M. S.

    2005-11-01

    Preface; Contributors; Introduction; Part I. Atomic Structure: 1. Development of atomic many-body theory Ingvar Lindgren; 2. Relativistic MBPT for highly charged ions W. R. Johnson; 3. Parity nonconservation in atoms S. A. Blundell, W. R. Johnson, and J. Sapirstein; Part II. Photoionization of Atoms: 4. Single photoionization processes J. J. Boyle, and M. D. Kutzner; 5. Photoionization dominated by double excitation T. N. Chang; 6. Direct double photoionization in atoms Z. W. Liu; 7. Photoelectron angular distributions Steven T. Manson; Part III. A. Atomic Scattering - General Considerations: 8. The many-body approach to electron-atom collisions M. Ya Amusia; 9. Theoretical aspects of electron impact ionization P. L. Altick; Part III. B. Atomic Scattering - Low-Order Applications: 10. Perturbation series methods D. H. Madison; 11. Target dependence of the triply differential cross section Cheng Pan and Anthony F. Starace; 12. Overview of Thomas processes for fast mass transfer J. H. McGuire, Jack C. Straton and T. Ishihara; Part III. C. Atomic Scattering - All-Order Applications: 13. R-matrix Theory: Some Recent Applications Philip G. Burke: 14. Electron scattering: application of Dirac R-matrix theory Wasantha Wijesundera, Ian Grant and Patrick Norrington; 15. Close coupling and distorted-wave theory D. C. Griffin and M. S. Pindzola; Appendix: Units and notation; References; Index.

  9. Observation of Cold Collisions between Trapped Ions and Trapped Atoms

    NASA Astrophysics Data System (ADS)

    Grier, Andrew T.; Cetina, Marko; Oručević, Fedja; Vuletić, Vladan

    2009-06-01

    We study cold collisions between trapped ions and trapped atoms in the semiclassical (Langevin) regime. Using Yb+ ions confined in a Paul trap and Yb atoms in a magneto-optical trap, we investigate charge-exchange collisions of several isotopes over three decades of collision energies down to 3μeV (kB×35mK). The minimum measured rate coefficient of 6×10-10cm3s-1 is in good agreement with that derived from a Langevin model for an atomic polarizability of 143 a.u.

  10. A graphical R-matrix atomic collision environment

    NASA Astrophysics Data System (ADS)

    Busby, David William

    [/cal R]-matrix theory has been used effectively to compute properties characterising atomic and molecular collisions. Large Fortran packages have been developed over the past twenty-five years, which are esoteric and can sometimes be difficult to use. The aim of this research is to design and implement, using modern computer science techniques, an environment which will render the packages more straight forward and accessible. It is postulated that the interactive manipulation of graphical abstractions of the underlying physics will allow the user to concentrate on the physics of the process being studied. This approach renders the new [/cal R]-matrix packages simple to use by novice and experienced users alike, thereby improving their usefulness to the physics community. The Graphical [/cal R]-matrix Atomic Collision Environment (G[/cal R]ACE) is comprised of four graphical user interfaces. Grace expedites the construction and editing of input data stipulated by the [/cal R]-matrix program packages. Data can be entered symbolically and is extensively validated, through a series of graphical windows. The generated text file enables the [/cal R]-matrix package to be executed on a remote supercomputer to which the workstation is networked. Connected to a database of Clementi-type orbitals, pseudo facilitates the computation of pseudo-orbitals, incorporated in grace. The H-file [/cal B]rowser displays a graphical abstraction representing the physics of an inner region [/cal R]-matrix computation. This pin-points limitations which may need to be modified to improve the computation. [/cal A]nalysis provides a graphical environment on the local workstation where results of the remote computation may be displayed and interpreted. Eigenphase sums can be displayed graphically as a function of energy, where resonance fits can be performed. [/cal A]nalysis enables further points to be calculated if there is insufficient data. Effective collisions strengths can also be

  11. Classical approach in atomic physics

    NASA Astrophysics Data System (ADS)

    Solov'ev, E. A.

    2011-12-01

    The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of a hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom discovered with the help of Poincaré section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treated as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well.

  12. Effects of hydrogen atom spin exchange collisions on atomic hydrogen maser oscillation frequency

    NASA Technical Reports Server (NTRS)

    Crampton, S. B.

    1979-01-01

    Frequency shifts due to collisions between hydrogen atoms in an atomic hydrogen maser frequency standard are studied. Investigations of frequency shifts proportional to the spin exchange frequency shift cross section and those proportional to the duration of exchange collisions are discussed. The feasibility of operating a hydrogen frequency standard at liquid helium temperatures is examined.

  13. Positron collisions with alkali-metal atoms

    NASA Technical Reports Server (NTRS)

    Gien, T. T.

    1990-01-01

    The total cross sections for positron and electron collisions with potassium, sodium, lithium and rubidium are calculated, employing the modified Glauber approximation. The Modified Glauber cross sections for positron collision with potassium and sodium at low intermediate energies are found to agree reasonably well with existing experimental data.

  14. Inelastic transitions in slow heavy-particle atomic collisions

    SciTech Connect

    Krstic, P. S.; Reinhold, C. O.; Burgdo''rfer, J.

    2001-05-01

    It is a generally held belief that inelastic transition probabilities and cross sections in slow, nearly adiabatic atomic collisions decrease exponentially with the inverse of the collision velocity v [i.e., {sigma}{proportional_to}exp(-const/v)]. This notion is supported by the Landau-Zener approximation and the hidden crossings approximation. We revisit the adiabatic limit of ion-atom collisions and show that for very slow collisions radial transitions are dominated by the topology of the branch points of the radial velocity rather than the branch points of the energy eigensurface. This can lead to a dominant power-law dependence of inelastic cross sections, {sigma}{proportional_to}v{sup n}. We illustrate the interplay between different contributions to the transition probabilities in a one-dimensional collision system for which the exact probabilities can be obtained from a direct numerical solution of the time-dependent Scho''dinger equation.

  15. Undergraduate Research Projects in Atomic Collisions and Gamma-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sanders, J. M.; Varghese, S. L.; Haywick, D. W.; Fearn, M. L.

    2003-08-01

    Research projects at University of South Alabama, an undergraduate physics department, have employed a 150-kV Cockcroft-Walton accelerator for atomic collisions and sodium-iodide and high-purity germanium detectors for gamma-ray studies. The atomic collision experiments dealt with electron capture and electron loss in collisions of protons and hydrogen atoms with hydrocarbon molecules. Gamma-ray studies with NaI scintillators determined the potassium content of food using 40K gamma-rays. Environmental studies of river sedimentation use a HPGe detector to determine 137Cs and 210Pb content. Students learn the physics of the interactions of ionizing radiation with matter, while acquiring a familiarity with high-vacuum technique, electronics, data acquisition and analysis, and reporting of results.

  16. Treatment of ion-atom collisions using a partial-wave expansion of the projectile wavefunction

    SciTech Connect

    Foster, M; Colgan, J; Wong, T G; Madison, D H

    2008-01-01

    We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge scattering quantities. Here we show that such calculations are possible using modern high-performance computing. We demonstrate the utility of our method by examining elastic scattering of protons by hydrogen and helium atoms, problems familiar to undergraduate students of atomic scattering. Application to ionization of helium using partial-wave expansions of the projectile wavefunction, which has long been desirable in heavy-ion collision physics, is thus quite feasible.

  17. Metal vapor target for precise studies of ion-atom collisions

    SciTech Connect

    Chen, W. Vorobyev, G.; Herfurth, F.; Hillenbrand, P.-M.; Spillmann, U.; Guo, D.; Trotsenko, S.; Gumberidze, A.; Stöhlker, Th.

    2014-05-15

    Although different ion-atom collisions have been studied in various contexts, precise values of cross-sections for many atomic processes were seldom obtained. One of the main uncertainties originates from the value of target densities. In this paper, we describe a unique method to measure a target density precisely with a combination of physical vapor deposition and inductively coupled plasma optical emission spectrometry. This method is preliminarily applied to a charge transfer cross-section measurement in collisions between highly charged ions and magnesium vapor. The final relative uncertainty of the target density is less than 2.5%. This enables the precise studies of atomic processes in ion-atom collisions, even though in the trial test the deduction of precise capture cross-sections was limited by other systematic errors.

  18. Newly appreciated roles for electrons in ion-atom collisions

    SciTech Connect

    Sellin, I.A. . Dept. of Physics and Astronomy Oak Ridge National Lab., TN )

    1990-01-01

    Since the previous Debrecen workshop on High-Energy Ion-Atom Collisions there have been numerous experiments and substantial theoretical developments in the fields of fast ion-atom and ion- solid collisions concerned with explicating the previously largely underappreciated role of electrons as ionizing and exciting agents in such collisions. Examples to be discussed include the double electron ionization problem in He; transfer ionization by protons in He; double excitation in He; backward scattering of electrons in He; the role of electron-electron interaction in determining beta parameters for ELC; projectile K ionization by target electrons; electron spin exchange in transfer excitation; electron impact ionization in crystal channels; resonant coherent excitation in crystal channels; excitation and dielectronic recombination in crystal channels; resonant transfer and excitation; the similarity of recoil ion spectra observed in coincidence with electron capture vs. electron loss; and new research on ion-atom collisions at relativistic energies.

  19. Time-dependent, lattice approach to atomic collisions

    SciTech Connect

    Schultz, D.R.

    1995-12-31

    Recent progress in developing and applying methods of direct numerical solution of atomic collision problems is described. Various forms of the three-body problem are used to illustrate these techniques. Specifically, the process of ionization in proton-, antiproton-, and electron-impact of atomic hydrogen is considered in applications ranging in computational intensity from collisions simulated in two spatial dimensions to treatment of the three-dimensional, fully correlated two-electron Schroedinger equation. These examples demonstrate the utility and feasibility of treating strongly interacting atomic systems through time-dependent, lattice approaches.

  20. The Underlying Physics in Wetted Particle Collisions

    NASA Astrophysics Data System (ADS)

    Donahue, Carly; Hrenya, Christine; Davis, Robert

    2008-11-01

    Wetted granular particles are relevant in many industries including the pharmaceutical and chemical industries and has applications to granulation, filtration, coagulation, spray coating, drying and pneumatic transport. In our current focus, we investigate the dynamics of a three-body normal wetted particle collision. In order to conduct collisions we use an apparatus called a ``Stokes Cradle,'' similar to the Newton's Cradle (desktop toy) except that the target particles are covered with oil. Here, we are able to vary the oil thickness, oil viscosity, and material properties. With a three particle collision there are four possible outcomes: fully agglomerated (FA); Newton's Cradle (NC), the striker and the first target ball are agglomerated and the last target ball is separated; Reverse Newton's Cradle (RNC), the striker is separated and the two targets are agglomerated; and fully separated (FS). Varying the properties of the collisions, we have observed all four outcomes. We use elastohydrodynamics as a theoretical basis for modeling the system. We also have considered the glass transition of the oil as the pressure increases upon impact and the cavitation of the oil as the pressure drops below the vapor pressure upon rebound. A toy model has been developed where the collision is modeled as a series of two-body collisions. A qualitative agreement between the toy model and experiments gives insight into the underlying physics.

  1. Collisions of Electrons with Atomic Oxygen: Current Status

    NASA Technical Reports Server (NTRS)

    Johnson, P. V.; Kanik, I.; Tayal, S. S.

    2005-01-01

    In 1990, two significant reviews of electron-atomic-oxygen collision processes were published. Since that time, a large volume of both experimental and theoretical research into these processes has occurred. These data are reviewed and recommendations regarding existing data sets and future research in this area are made. Attention is given to the challenges associated with handling atomic oxygen in terms of both experiment and theory.

  2. Light assisted collisions in ultra cold Tm atom

    NASA Astrophysics Data System (ADS)

    Akimov, Alexey; Cojocaru, Ivan; Pyatchenkov, Sergey; Snigirev, Stepan; Luchnokov, Ilia; Sukachev, Denis; Kalganova, Elena; Sorokin, Vadim

    2016-05-01

    Recently laser cooled rare earth elements attracted considerable attention due to the high orbital and magnetic moments. Such a systems allow low-field Feshabach resonances enabling tunable in wide range interactions. In particular, thulium atom has one hole in 4f shell therefore having orbital moment of 3 in the ground state, magnetic moment of 4 Bohr magnetons in ground state. While magnetic moment of the thulium atom is less than that of Erbium or Dysprosium simpler level structure, possibility to capture thulium atoms and the dipole trap at 532 nm make thulium atom an extremely attractive subject for quantum simulations. Nevertheless collisional properties of thulium atom are not yet explored in details, in particular light assisted collision of thulium atom were not yet investigated. In this contribution, we performed studies of light assisted collisions near in Magneto optical trap operating on narrow 530.7 nm transition. We found, that light assisted inelastic binary collisions losses rate is around β ~10-9cm3cm3s s . Possible mechanism of losses from the trap are discussed

  3. Electron-atom collisions in a laser field

    NASA Astrophysics Data System (ADS)

    Smith, Philip H. G.; Flannery, M. R.

    1991-05-01

    Cross sections tor the 1S-2S and 1S-2P 0 transitions in laser assisted e-H(1S) collisions are calculated in both the multichannel eikonal and the Born-wave treatments as a function of impact energy and laser field intensity and phase. The laser considered is a monotonic, plane polarized CO 2 laser (photon energy = 0.117 eV), with the polarization direction parallel to the initial projectile velocity. Floquet dressing of the hydrogen atom in the soft-photon weak-field limit reveals a concise description of the laser assisted electron-atom collision. This model also links the microscopic detail of the individual collisions with the macroscopic considerations of experimental analysis.

  4. Few electron transitions in atomic collisions. Final report, September 1, 1992--December 31, 1995

    SciTech Connect

    McGuire, J.

    1997-04-01

    During the past three years we have evaluated probabilities and cross sections for few and multiple electron transitions in atomic collisions. Our studies included interactions of atoms and molecules with incident protons, bare ions, electrons, positrons, anti-protons, ions carrying electrons and photons. We also: studied the inter-relation between collisions with charged particles and collisions involving various processes with photons. This work has complemented various studies of collisions of atoms with charged particles and with photons as well as more general efforts to understand the nature of multi-electron systems. Our aim has been to begin with relatively simple two electron systems and to focus on fast processes in which there is too little time for complicated processes to occur. We have used a variety of computational techniques, but we emphasize those appropriate for fast collisions in which we hope to obtain insight into the physical nature of the process itself. We generally considered systems in which experimental data was available.

  5. Manipulating ion-atom collisions with coherent electromagnetic radiation.

    PubMed

    Kirchner, Tom

    2002-08-26

    Laser-assisted ion-atom collisions are considered in terms of a nonperturbative quantum mechanical description of the electronic motion. It is shown for the system He(2+) - H at 2 keV/amu that the collision dynamics depend strongly on the initial phase of the laser field and the applied wavelength. Whereas electronic transitions are caused by the concurrent action of the field and the projectile ion at relatively low frequencies, they can be separated into modified collisional capture and field ionization events in the region above the one-photon ionization threshold.

  6. International Conference on the Physics of Electronic and Atomic Collisions. Participants List (16th), Held in New York, New York on 26 July-1 August 1989

    DTIC Science & Technology

    1989-08-01

    AVE.LINCOLN, NE 68509-0111 CEDEX, MENLO PARK, CA 94025 USA FRANCE USA RONALD A. PHANEUF JEAN - CLAUDE POIZATOAK RIDGE NAT’L LAB ARTHUR V. PHELPS UNIVERSITE...SHABANA GAIYOOM JEAN W. GALLAGHER LATVIAN ACAD. SCI. UNIV COLLEGE LONDON N.I.S.T. RTGA, GOWER ST. A323 PHYSICS BLDG. USSR LONDON, WCIE 6BT GAITHERSBURG...TOKYO, 102 D-6300 GIESSEN, USA JAPAN FRG MANFRED SALZMAN DOUGLAS H. SAMPSON JOSEPH SANDERSON TELTOWER DAMM 223B PENN STATE UNIV UNIV COLLEGE LONDON

  7. Intimate relationship between spectroscopy and collisions: a scenario to calculate relevant atomic data for astrophysics

    NASA Astrophysics Data System (ADS)

    Gao, Xiang; Han, Xiao-Ying; Li, Jia-Ming

    2016-11-01

    An extended atomic data base with sufficiently high precision in energy levels and transition/collision rates is required for satellite observation in astrophysics studies and energy development research in inertial confinement fusion and magnetic confinement fusion. We summarize in this paper a scenario for performing calculations leading to such large-scale atomic data with high precision based on the analytical continuation properties of the scattering matrices, connecting spectroscopy and collisions. Based on the scenario, we calculate directly the scattering matrices with spectroscopic accuracy, i.e. the accurate multi-channel quantum defect theory parameters in both bound and continuum energy regions based on the recently developed eigenchannel R-matrix approach. Applications of the related atomic processes are presented to demonstrate the advantages enjoyed by this approach, which is hoped to meet the requirements in the stages of precision physics for astrophysics and energy research.

  8. Improved atomic model for charge transfer in multielectron ion-atom collisions at intermediate energies

    NASA Astrophysics Data System (ADS)

    Lin, C. D.; Tunnell, L. N.

    1980-07-01

    Electron capture to the K shell of projectiles from the K and other subshells of multielectron target atoms is studied in the intermediate energy region using the single-active-electron approximation and the two-state, two-center atomic eigenfunction expansion method. It is concluded that the theoretical capture cross section is not sensitive to the atomic models used at high collision energies where the projectile velocity v is near or greater than the orbital velocity ve of the active electron. For vatomic potential such as the Herman-Skillman potential is needed to represent the target atom. The insufficiency of various simple Coulomb model potentials is illustrated. Capture cross sections for a few collision systems are obtained and compared with experimental data when available to illustrate the reliability of the present model.

  9. Bringing Atoms into First-Year Physics.

    ERIC Educational Resources Information Center

    Chabay, Ruth W.; Sherwood, Bruce A.

    1999-01-01

    Argues that thermal physics should not be treated as a separate topic in introductory physics. Provides an example of a course that emphasizes physical modeling of the phenomenon in terms of the atomic nature of matter. (Author/CCM)

  10. PREFACE: XXVIth International Conference on Photonic, Electronic and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Orel, Ann; Starace, Anthony F.; Nikolić, Dragan; Berrah, Nora; Gorczyca, Thomas W.; Kamber, Emanuel Y.; Tanis, John A.

    2009-12-01

    The XXVIth International Conference on Photonic, Electronic and Atomic Collisions was held on the campus of Western Michigan University (WMU) in Kalamazoo during 22-28 July 2009. Kalamazoo, the home of a major state university amid pleasant surroundings, was a delightful place for the conference. The 473 scientific participants, 111 of whom were students, had many fruitful discussions and exchanges that contributed to the success of the conference. Participants from 43 countries made the conference truly international in scope. The 590 abstracts that were presented on the first four days formed the heart of the conference and provided ample opportunity for discussion. This change, allowing the conference to end with invited talks, was a departure from the format used at previous ICPEAC gatherings in which the conferences ended with a poster session. The abstracts were split almost equally between the three main conference areas, i.e., photonic, electronic, and atomic collisions, and the posters were distributed across the days of the conference so that approximately equal numbers of abstracts in the different areas were scheduled for each day. Of the total number of presented abstracts, 517 of these are included in this proceedings volume, the first time that abstracts have been published by ICPEAC. There were 5 plenary lectures covering the different areas of the conference: Paul Corkum (University of Ottawa) talked on attosecond physics with atoms and molecules, Serge Haroche (Collège de France) on non-destructive photon counting, Toshiyuki Azuma (Tokyo Metropolitan University) on resonant coherent excitation of highly-charged ions in crystals, Eva Lindroth (Stockholm University) on atomic structure effects, and Alfred Müller (Justus Liebig University) on resonance phenomena in electron- and photon-ion collisions. Two speakers gave very illuminating public lectures that drew many people from the local area, as well as conference participants: Patricia Dehmer

  11. Reply to Origin of fast electrons' from slow atomic collisions''

    SciTech Connect

    Baragiola, R.A. ); Alonso, E.V. ); Oliva, A.; Bonanno, A.; Xu, F. )

    1993-08-01

    We show reasons why negative ions cannot contribute significantly to our observation of fast electrons in slow atomic collisions [Phys. Rev. 45, 5286 (1992)]. We point out that the opposite suggestion by Yasui [preceding Comment, Phys. Rev. A 48, 1711 (1993)] results from multiple errors in his analysis, including inadequate consideration of energy conservation, the use of nonapplicable data from the literature, neglect of decay in flight of metastable negative ions, nonconsideration of detection efficiency, and the inconsistent fit of experimental data.

  12. Physics of Nuclear Collisions at High Energy

    SciTech Connect

    Hwa, Rudolph C.

    2012-05-01

    A wide range of problems has been investigated in the research program during the period of this grant. Although the major effort has been in the subject of heavy-ion collisions, we have also studied problems in biological and other physical systems. The method of analysis used in reducing complex data in multiparticle production to simple descriptions can also be applied to the study of complex systems of very different nature. Phase transition is an important phenomenon in many areas of physics, and for heavy-ion collisions we study the fluctuations of multiplicities at the critical point. Human brain activities as revealed in EEG also involve fluctuations in time series, and we have found that our experience enables us to find the appropriate quantification of the fluctuations in ways that can differentiate stroke and normal subjects. The main topic that characterizes the research at Oregon in heavy-ion collisions is the recombination model for the treatment of the hadronization process. We have avoided the hydrodynamical model partly because there is already a large community engaged in it, but more significantly we have found the assumption of rapid thermalization unconvincing. Recent results in studying LHC physics lead us to provide more evidence that shower partons are very important even at low p_T, but are ignored by hydro. It is not easy to work in an environment where the conventional wisdom regards our approach as being incorrect because it does not adhere to the standard paradigm. But that is just what a vibrant research community needs: unconventional approach may find evidences that can challenge the orthodoxy. An example is the usual belief that elliptic flow in fluid dynamics gives rise to azimuthal anisotropy. We claim that it is only sufficient but not necessary. With more data from LHC and more independent thinkers working on the subject what is sufficient as a theory may turn out to be incorrect in reality. Another area of investigation that

  13. Saturation Effect of Projectile Excitation in Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Mukoyama, Takeshi; Lin, Chii-Dong

    Calculations of projectile K-shell electron excitation cross sections for He-like ions during ion-atom collisions have been performed in the distortion approximation by the use of Herman-Skillman wave functions. The calculated results are compared with the experimental data for several targets. The excitation cross sections deviate from the first-Born approximation and show the saturation effect as a function of target atomic number. This effect can be explained as the distortion of the projectile electronic states by the target nucleus.

  14. Collision lifetimes of polyatomic molecules at low temperatures: Benzene-benzene vs benzene-rare gas atom collisions

    NASA Astrophysics Data System (ADS)

    Cui, Jie; Li, Zhiying; Krems, Roman V.

    2014-10-01

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atom-molecule interaction. We then compare the results of the atom-benzene calculations with those for benzene-benzene collisions. The comparison illustrates that the mean lifetimes of the benzene-benzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzene-benzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  15. Collision lifetimes of polyatomic molecules at low temperatures: benzene-benzene vs benzene-rare gas atom collisions.

    PubMed

    Cui, Jie; Li, Zhiying; Krems, Roman V

    2014-10-28

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atom-molecule interaction. We then compare the results of the atom-benzene calculations with those for benzene-benzene collisions. The comparison illustrates that the mean lifetimes of the benzene-benzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzene-benzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  16. The Strange World of Ultracold Atomic Collisions: A Cornucopia of Quantum Phenomena

    NASA Astrophysics Data System (ADS)

    Williams, Carl J.

    1996-11-01

    The phenomenal experimental success of laser cooling and atom trapping has has helped to reinvigorate the field of atomic physics and has spawned the field of ultracold atomic collisions. This talk presents an overview of ultracold atomic collisions with an emphasis on some of the remarkable quantum phenomena -- including the Wigner threshold law -- that are inherent in these collisions. Additionally, we discuss the importance of ultracold collisions in Bose-Einstein condensation (BEC) of weakly interacting atomic systems and their role in the development of an atom laser and atomic clocks. Ultracold atomic collisions can be loosely broken into two classes of problems, collisions of ground state atoms (including metastable atoms) and the collision of atoms in external electric fields. In this latter class is the field of photoassociation spectroscopy. Theoretical analysis of the photoassociation spectrum of the Na2 purely long-range 0^-g state has recently produced three remarkable results. The first two results include the currently most accurate determination of the Na(3P) lifetime and the observation of the predicted but previously unobserved effect of retardation in the interaction between two atoms(K. M. Jones, P. S. Julienne, P. D. Lett, W. D. Phillips, E. Tiesinga, and C. J. Williams, Europhys. Lett. 35), 85 (1996).. Finally, the scattering length for the collision of two Na(3S) atoms in their F=1, M_F=-1 hyperfine state was extracted from the intensities and widths of the 0^-g spectra(E. Tiesinga, C. J. Williams, P. S. Julienne, K. M. Jones, P. D. Lett, and W. D. Phillips, J. Res. Nat. Inst. Stand. Technol. 101) (1996, in press).. Similar types of results have also been obtained in Li_2, K_2, and Rb_2. Ground state scattering lengths are essential for both modeling the formation of a BEC and for understanding collisional loss processes in a BEC. Similar collisional processes are important in pressure shifts in atomic clocks. We use the value of the of the

  17. General model of depolarization and transfer of polarization of singly ionized atoms by collisions with hydrogen atoms

    NASA Astrophysics Data System (ADS)

    Derouich, M.

    2017-02-01

    Simulations of the generation of the atomic polarization is necessary for interpreting the second solar spectrum. For this purpose, it is important to rigorously determine the effects of the isotropic collisions with neutral hydrogen on the atomic polarization of the neutral atoms, ionized atoms and molecules. Our aim is to treat in generality the problem of depolarizing isotropic collisions between singly ionized atoms and neutral hydrogen in its ground state. Using our numerical code, we computed the collisional depolarization rates of the p-levels of ions for large number of values of the effective principal quantum number n* and the Unsöld energy Ep. Then, genetic programming has been utilized to fit the available depolarization rates. As a result, strongly non-linear relationships between the collisional depolarization rates, n* and Ep are obtained, and are shown to reproduce the original data with accuracy clearly better than 10%. These relationships allow quick calculations of the depolarizing collisional rates of any simple ion which is very useful for the solar physics community. In addition, the depolarization rates associated to the complex ions and to the hyperfine levels can be easily derived from our results. In this work we have shown that by using powerful numerical approach and our collisional method, general model giving the depolarization of the ions can be obtained to be exploited for solar applications.

  18. Atomic physics with highly charged ions

    SciTech Connect

    Richard, P.

    1991-08-01

    This report discusses: One electron outer shell processes in fast ion-atom collisions; role of electron-electron interaction in two-electron processes; multi-electron processes at low energy; multi-electron processes at high energy; inner shell processes; molecular fragmentation studies; theory; and, JRM laboratory operations.

  19. Physics through the 1990s: Atomic, molecular and optical physics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The volume presents a program of research initiatives in atomic, molecular, and optical physics. The current state of atomic, molecular, and optical physics in the US is examined with respect to demographics, education patterns, applications, and the US economy. Recommendations are made for each field, with discussions of their histories and the relevance of the research to government agencies. The section on atomic physics includes atomic theory, structure, and dynamics; accelerator-based atomic physics; and large facilities. The section on molecular physics includes spectroscopy, scattering theory and experiment, and the dynamics of chemical reactions. The section on optical physics discusses lasers, laser spectroscopy, and quantum optics and coherence. A section elucidates interfaces between the three fields and astrophysics, condensed matter physics, surface science, plasma physics, atmospheric physics, and nuclear physics. Another section shows applications of the three fields in ultra-precise measurements, fusion, national security, materials, medicine, and other topics.

  20. Correlated eikonal initial state in ion-atom collisions

    SciTech Connect

    Ciappina, M.F.; Otranto, S.; Garibotti, C.R.

    2002-11-01

    An approximation is developed to deal with the ionization of atoms by bare charged ions. In this method the transition amplitude describing the three-body final state is evaluated using a continuum correlated wave and that for the initial state by an analytical continuation of the {phi}{sub 2} model to complex momenta. This procedure introduces in the atomic bound state a kinematical correlation with the projectile motion. Doubly differential cross sections (DDCS's) are computed for collisions of H{sup +} and F{sup 9+} ions with He atoms. Results for the DDCS's in the forward direction are compared with experimental data and other theoretical models. We find an enhancement of the distribution for low energy electrons and that the asymmetry of the electron capture to the continuum (ECC) peak is correctly described.

  1. Atomic collisions with 33-TeV lead ions

    SciTech Connect

    Vane, C.R.; Datz, S.; Krause, H.F.

    1996-10-01

    Recent availability of relativistic and ultrarelativistic beams of heavy ions has permitted the first controlled studies of atomic collisions at energies sufficient to measure effects of several new basic phenomena. These include measurements substantiating recently predicted finite nuclear size effects resulting in a reduction in the total electronic energy loss of heavy ions in matter, and measurements of Coulomb collisions in which electrons are excited from the Dirac negative energy continuum. Measurements of total energy loss, free electron-positron pair production, and electron capture from pair production have been recently performed using 33-TeV Pb{sup 82+} ions from the CERN SPS accelerator in Geneva. Results of these studies are presented, along with comparisons with relevant theory.

  2. Light-assisted collisions in ultracold Tm atoms

    NASA Astrophysics Data System (ADS)

    Cojocaru, I. S.; Pyatchenkov, S. V.; Snigirev, S. A.; Luchnikov, I. A.; Kalganova, E. S.; Vishnyakova, G. A.; Kublikova, D. N.; Bushmakin, V. S.; Davletov, E. T.; Tsyganok, V. V.; Belyaeva, O. V.; Khoroshilov, A.; Sorokin, V. N.; Sukachev, D. D.; Akimov, A. V.

    2017-01-01

    We studied light-assisted collisions of Tm atoms in a magneto-optical trap (MOT), working on a weak cooling transition at 530.7 nm [4 f13(F2o) 6 s2,J =7 /2 ,F =4 to 4 f12(H36) 5 d5 /26 s2,J =9 /2 ,F =5 ]. We observed a strong influence from radiation trapping and light-assisted collisions on the dynamics of this trap. We carefully separated these two contributions and measured the binary loss rate constant at different laser powers and detuning frequencies near the cooling transition. Analyzing losses from the MOT, we found the light-assisted inelastic binary loss rate constant to reach values of up to β =10-9c m3/s and gave the upper bound on a branching ratio k <0.8 ×10-6 for the 530.7 nm transition.

  3. Theoretical atomic physics code development I: CATS: Cowan Atomic Structure Code

    SciTech Connect

    Abdallah, J. Jr.; Clark, R.E.H.; Cowan, R.D.

    1988-12-01

    An adaptation of R.D. Cowan's Atomic Structure program, CATS, has been developed as part of the Theoretical Atomic Physics (TAPS) code development effort at Los Alamos. CATS has been designed to be easy to run and to produce data files that can interface with other programs easily. The CATS produced data files currently include wave functions, energy levels, oscillator strengths, plane-wave-Born electron-ion collision strengths, photoionization cross sections, and a variety of other quantities. This paper describes the use of CATS. 10 refs.

  4. Quantum dynamics in ultracold atomic physics

    NASA Astrophysics Data System (ADS)

    He, Qiong-Yi; Reid, Margaret D.; Opanchuk, Bogdan; Polkinghorne, Rodney; Rosales-Zárate, Laura E. C.; Drummond, Peter D.

    2012-02-01

    We review recent developments in the theory of quantum dynamics in ultracold atomic physics, including exact techniques and methods based on phase-space mappings that are applicable when the complexity becomes exponentially large. Phase-space representations include the truncated Wigner, positive- P and general Gaussian operator representations which can treat both bosons and fermions. These phase-space methods include both traditional approaches using a phase-space of classical dimension, and more recent methods that use a non-classical phase-space of increased dimensionality. Examples used include quantum Einstein-Podolsky-Rosen (EPR) entanglement of a four-mode BEC, time-reversal tests of dephasing in single-mode traps, BEC quantum collisions with up to 106 modes and 105 interacting particles, quantum interferometry in a multi-mode trap with nonlinear absorption, and the theory of quantum entropy in phase-space. We also treat the approach of variational optimization of the sampling error, giving an elementary example of a nonlinear oscillator.

  5. Interaction of Radiation with Matter: Atomic Collision Processes Occurring in the Presence of Radiation Fields

    DTIC Science & Technology

    1988-09-15

    Degenerate Four -Wave Mixing,* Saturation Spectroscopy,’ Dressed Atom,’ Photon Echo: Bloch Equations’, Collision Kernel; Collisions; Optical Noise, 20...information regarding high resolution laser spectroscopy. The initial problem which was studied involved the four -wave mixing signals generated in Na vapor...in four -wave mixing. If the ground and excited state collision rates for a two-level atom differ, collisions result in non-conservation of population

  6. Relativistic atomic physics at the SSC

    SciTech Connect

    1990-12-31

    This report discusses the following proposed work for relativistic atomic physics at the Superconducting Super Collider: Beam diagnostics; atomic physics research; staffing; education; budget information; statement concerning matching funds; description and justification of major items of equipment; statement of current and pending support; and assurance of compliance.

  7. Atomic collision processes for modelling cool star spectra

    NASA Astrophysics Data System (ADS)

    Barklem, Paul

    2015-05-01

    The abundances of chemical elements in cool stars are very important in many problems in modern astrophysics. They provide unique insight into the chemical and dynamical evolution of the Galaxy, stellar processes such as mixing and gravitational settling, the Sun and its place in the Galaxy, and planet formation, to name a just few examples. Modern telescopes and spectrographs measure stellar spectral lines with precision of order 1 per cent, and planned surveys will provide such spectra for millions of stars. However, systematic errors in the interpretation of observed spectral lines leads to abundances with uncertainties greater than 20 per cent. Greater precision in the interpreted abundances should reasonably be expected to lead to significant discoveries, and improvements in atomic data used in stellar atmosphere models play a key role in achieving such advances in precision. In particular, departures from the classical assumption of local thermodynamic equilibrium (LTE) represent a significant uncertainty in the modelling of stellar spectra and thus derived chemical abundances. Non-LTE modelling requires large amounts of radiative and collisional data for the atomic species of interest. I will focus on inelastic collision processes due to electron and hydrogen atom impacts, the important perturbers in cool stars, and the progress that has been made. I will discuss the impact on non-LTE modelling, and what the modelling tells us about the types of collision processes that are important and the accuracy required. More specifically, processes of fundamentally quantum mechanical nature such as spin-changing collisions and charge transfer have been found to be very important in the non-LTE modelling of spectral lines of lithium, oxygen, sodium and magnesium.

  8. Advances in atomic physics: Four decades of contribution of the Cairo University - Atomic Physics Group.

    PubMed

    El-Sherbini, Tharwat M

    2015-09-01

    In this review article, important developments in the field of atomic physics are highlighted and linked to research works the author was involved in himself as a leader of the Cairo University - Atomic Physics Group. Starting from the late 1960s - when the author first engaged in research - an overview is provided of the milestones in the fascinating landscape of atomic physics.

  9. Benchmarking Attosecond Physics with Atomic Hydrogen

    DTIC Science & Technology

    2015-05-25

    Final 3. DATES COVERED (From - To) 12 Mar 12 – 11 Mar 15 4. TITLE AND SUBTITLE Benchmarking attosecond physics with atomic hydrogen 5a...NOTES 14. ABSTRACT The research team obtained uniquely reliable reference data on atomic interactions with intense few-cycle laser pulses...AND SUBTITLE Benchmarking attosecond physics with atomic hydrogen 5a. CONTRACT NUMBER FA2386-12-1-4025 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  10. Coherence and correlations in fast ion-atom collisions

    SciTech Connect

    Burgdoerfer, J.

    1987-01-01

    This paper focusses on the description, classification and interpretation of coherent excitation of atomic or ionic systems with Coulombic two-body final state interactions. A group-theoretical approach is used to classify and interpret coherent excitation. The most significant result is that the state of excitation represented by a density operator can be mapped one to one onto expectation values of a set of operators. Examples are used to illustrate what can be learned about the collision process from investigations of coherent excitation. (JDH)

  11. Cold Rydberg atom collisions in a dipole trap

    NASA Astrophysics Data System (ADS)

    Cabral, Jader; Gonçalves, Luis; Kondo, Jorge; Marcassa, Luis

    2011-05-01

    We have built a new experimental setup to investigate cold Rydberg atom collision in a high atomic density sample in a CO2 dipole trap. Briefly, we load a Rb standard magneto-optical trap from an atomic vapor provided by a dispenser. Then we turn on 100W CO2 dipole trap and we apply a loading phase, in which the repumper light intensity is reduced. After this phase, the trapping and repumper laser beams are turned off and we wait 100 ms for the atoms that were not trapped to fall off the dipole trap region due to gravity. Finally, we turn off the dipole trap and excite the Rydberg state using a two photon transition. The Rydberg atoms are detected using pulsed field ionization technique. In this new setup, we can image the ions onto a MCP detector to study the spatial distribution. The electrons maybe detected also by another MCP. During the presentation we shall present preliminary results involving the excitation of nD+nD states. We acknowledge financial support from FAPESP, CNPq, INCT-IQ, AFOSR (FA9550-09-1-0503)

  12. Multiple scattering and charged-particle - hydrogen-atom collisions

    NASA Technical Reports Server (NTRS)

    Franco, V.; Thomas, B. K.

    1979-01-01

    Glauber-approximation scattering amplitudes for charged-particle - hydrogen-atom elastic and inelastic collisions are derived directly in terms of the known particle-electron and particle-proton Coulomb scattering amplitudes and the known hydrogen-atom form factors. It is shown that the particle-hydrogen amplitude contains no single-scattering term. The double-scattering term is obtained as a two-dimensional integral in momentum space. It is demonstrated how the result can be used as the starting point for an alternative and relatively simple derivation, in closed form, of the Glauber particle-hydrogen scattering amplitude for transitions from the ground state to an arbitrary (nlm) state.

  13. Positronium Formation During Inelastic Collisions of Positrons with Sodium Atoms

    NASA Astrophysics Data System (ADS)

    El-Bakry, Salah Yaseen

    The positronium (Ps) formation in different states of the inelastic collisions of positrons with sodium atoms is a multi-channel scattering process. In the present work, a wide region of incident energies is considered, ranging from 4eV to 100eV. The coupled-static and frozen-core approximations are employed for calculating the corresponding elastic, positronium (Ps (1s)) and excited positronium (Ps* (2s+np)) formation cross sections. np states are represented in form of their polarization potentials. The total cross sections which corresponding to eight partial cross sections (calculated at eight values of the total angular momentum l=0 to l=7) of the three channel problem have been calculated. The basis set of Clementi and Roetti [At. Data Nucl. Data Tables 14, 177 (1974)] is used for describing the target atom. The resulting total cross sections are compared with experimental results and those calculated by other authors.

  14. Charge exchange and ionization in hydrogen atom-fully stripped ion collisions in Debye plasmas

    SciTech Connect

    Zhang, H.; Wang, J. G.; He, B.; Qiu, Y. B.; Janev, R. K.

    2007-05-15

    The processes of charge exchange and ionization in collisions of ground state hydrogen atom with fully stripped ions in a weakly coupled plasma are studied by the classical trajectory Monte Carlo method in the collision energy range 10-900 keV/amu. The interparticle interactions are described by the Debye-Hueckel model with inclusion of dynamical effects associated with the projectile velocity. The microcanonical distribution of initial state electronic coordinates and momenta has been determined by inclusion of plasma screening effects. The cross section dependencies on plasma parameters and ion charge and velocity are investigated. It is shown that plasma effects on charge exchange and ionization cross sections are significant and particularly pronounced at low collision velocities. The results of systematic cross section calculations for different values of Debye screening length (in the range 1-50a{sub 0}) and ion charges (in the range 1-14) are presented.

  15. Convergent Close-Coupling Approach to Electron-Atom Collisions

    NASA Technical Reports Server (NTRS)

    Bray, Igor; Stelbovics, Andris

    2007-01-01

    It was with great pleasure and honour to accept the invitation to make a presentation at the symposium celebrating the life-long work of Aaron Temkin and Richard Drachman. The work of Aaron Temkin was particularly influential on our own during the development of the CCC method for electron-atom collisions. There are a number of key problems that need to be dealt with when developing a general computational approach to such collisions. Traditionally, the electron energy range was subdivided into the low, intermediate, and high energies. At the low energies only a finite number of channels are open and variational or close-coupling techniques could be used to obtain accurate results. At high energies an infinite number of discrete channels and the target continuum are open, but perturbative techniques are able to yield accurate results. However, at the intermediate energies perturbative techniques fail and computational approaches need to be found for treating the infinite number of open channels. In addition, there are also problems associated with the identical nature of electrons and the difficulty of implementing the boundary conditions for ionization processes. The beauty of the Temkin-Poet model of electron-hydrogen scattering is that it simplifies the full computational problem by neglecting any non-zero orbital angular momenta in the partial-wave expansion, without loosing the complexity associated with the above-mentioned problems. The unique nature of the problem allowed for accurate solution leading to benchmark results which could then be used to test the much more general approaches to electron-atom collision problems. The immense value of the Temkin-Poet model is readily summarised by the fact that the initial papers of Temkin and Poet have been collectively cited around 250 times to date and are still being cited in present times. Many of the citations came from our own work during the course of the development of the CCC method, which we now describe.

  16. Screening-Antiscreening Effect in Ion-Atom Collisions.

    NASA Astrophysics Data System (ADS)

    Hulskotter, Hans-Peter G.

    1990-01-01

    In a collision between an atomic projectile carrying one or more electrons and a target atom, one of the events that may occur is the ionization of a projectile electron. Projectile ionization, usually called electron loss, is normally attributed to the Coulomb interaction between the target nucleus and projectile electron. The effect of the target electrons can be accounted for partially by introducing a screened Coulomb interaction between the target and the projectile electron. However, the target electrons can not only act coherently as screening agents, but may also act incoherently as ionizing (antiscreening) agents. We have measured the cross sections for projectile K-shell ionization for 0.75 - 3.5 MeV/Nucleon Li^{2+ }, C^{5+}, and O^{7+} projectiles, for projectile electron loss of 100 and 380 MeV/Nucleon Au^{52+} projectiles in collisions with H_2, He, and N _2, and for 380 MeV/N Au^ {75+} projectiles in collisions with H _2 and N_2 targets. We unambiguously demonstrate that for energies where the target electrons have sufficient kinetic energy in the projectile frame to ionize the projectile electron, the electron-electron interaction can lead to a significant increase in the total ionization cross section. The largest relative increase we have been able to observe is 76%. The experimental results generally agree with plane-wave Born approximation calculations by Bates and Griffing and modified by Anholt which take into account the interaction between projectile and target electrons. We also describe the properties of a new target gas cell which has been designed and built for the use at the relativistic heavy-ion accelerator at Lawrence Berkeley Laboratory.

  17. ANGULAR MOMENTUM CHANGING TRANSITIONS IN PROTON-RYDBERG HYDROGEN ATOM COLLISIONS

    SciTech Connect

    Vrinceanu, D.; Onofrio, R.; Sadeghpour, H. R. E-mail: onofrior@gmail.com

    2012-03-01

    Collisions between electrically charged particles and neutral atoms are central for understanding the dynamics of neutral gases and plasmas in a variety of physical situations of terrestrial and astronomical interest. Specifically, redistribution of angular momentum states within the degenerate shell of highly excited Rydberg atoms occurs efficiently in distant collisions with ions. This process is crucial in establishing the validity of the local thermal equilibrium assumption and may also play a role in determining a precise ionization fraction in primordial recombination. We provide an accurate expression for the non-perturbative rate coefficient of collisions between protons and H(nl) ending in a final state H(nl'), with n being the principal quantum number and l, l' the initial and final angular momentum quantum numbers, respectively. The validity of this result is confirmed by results of classical trajectory Monte Carlo simulations. Previous results, obtained by Pengelly and Seaton only for dipole-allowed transitions l {yields} l {+-} 1, overestimate the l-changing collisional rate coefficients approximately by a factor of six, and the physical origin of this overestimation is discussed.

  18. Collision lifetimes of polyatomic molecules at low temperatures: Benzene–benzene vs benzene–rare gas atom collisions

    SciTech Connect

    Cui, Jie; Krems, Roman V.; Li, Zhiying

    2014-10-28

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atom–molecule interaction. We then compare the results of the atom–benzene calculations with those for benzene–benzene collisions. The comparison illustrates that the mean lifetimes of the benzene–benzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzene–benzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  19. Quantum chaos in ultracold collisions of gas-phase erbium atoms.

    PubMed

    Frisch, Albert; Mark, Michael; Aikawa, Kiyotaka; Ferlaino, Francesca; Bohn, John L; Makrides, Constantinos; Petrov, Alexander; Kotochigova, Svetlana

    2014-03-27

    Atomic and molecular samples reduced to temperatures below one microkelvin, yet still in the gas phase, afford unprecedented energy resolution in probing and manipulating the interactions between their constituent particles. As a result of this resolution, atoms can be made to scatter resonantly on demand, through the precise control of a magnetic field. For simple atoms, such as alkalis, scattering resonances are extremely well characterized. However, ultracold physics is now poised to enter a new regime, where much more complex species can be cooled and studied, including magnetic lanthanide atoms and even molecules. For molecules, it has been speculated that a dense set of resonances in ultracold collision cross-sections will probably exhibit essentially random fluctuations, much as the observed energy spectra of nuclear scattering do. According to the Bohigas-Giannoni-Schmit conjecture, such fluctuations would imply chaotic dynamics of the underlying classical motion driving the collision. This would necessitate new ways of looking at the fundamental interactions in ultracold atomic and molecular systems, as well as perhaps new chaos-driven states of ultracold matter. Here we describe the experimental demonstration that random spectra are indeed found at ultralow temperatures. In the experiment, an ultracold gas of erbium atoms is shown to exhibit many Fano-Feshbach resonances, of the order of three per gauss for bosons. Analysis of their statistics verifies that their distribution of nearest-neighbour spacings is what one would expect from random matrix theory. The density and statistics of these resonances are explained by fully quantum mechanical scattering calculations that locate their origin in the anisotropy of the atoms' potential energy surface. Our results therefore reveal chaotic behaviour in the native interaction between ultracold atoms.

  20. Making More-Complex Molecules Using Superthermal Atom/Molecule Collisions

    NASA Technical Reports Server (NTRS)

    Shortt, Brian; Chutjian, Ara; Orient, Otto

    2008-01-01

    A method of making more-complex molecules from simpler ones has emerged as a by-product of an experimental study in outer-space atom/surface collision physics. The subject of the study was the formation of CO2 molecules as a result of impingement of O atoms at controlled kinetic energies upon cold surfaces onto which CO molecules had been adsorbed. In this study, the O/CO system served as a laboratory model, not only for the formation of CO2 but also for the formation of other compounds through impingement of rapidly moving atoms upon molecules adsorbed on such cold interstellar surfaces as those of dust grains or comets. By contributing to the formation of increasingly complex molecules, including organic ones, this study and related other studies may eventually contribute to understanding of the origins of life.

  1. Atomic and Molecular Physics Program

    DTIC Science & Technology

    2013-03-05

    DESCRIPTION OF PORTFOLIO: Understanding interactions between atoms, molecules, ions, and radiation. SUB-AREAS IN PORTFOLIO: • Cold Quantum ...Gases − Strongly-interacting quantum gases − Ultracold molecules − New phases of matter − Non-equilibrium quantum dynamics • Quantum Information...Science (QIS) − Quantum simulation − Quantum communication − Quantum metrology, sensing, and imaging − Cavity optomechanics 3 DISTRIBUTION STATEMENT

  2. Atomic cluster collisions: ISACC-2015 (7th International Symposium)*

    NASA Astrophysics Data System (ADS)

    Prosmiti, Rita; Villarreal, Pablo; Delgado-Barrio, Gerardo; Solov'yov, Andey V.

    2017-02-01

    The ISACC 2015 brought together nearly a hundred scientists in the field of atomic and molecular cluster physics from around the world. We deliver the Editorial of a topical issue compiling/presenting original research results from some of the participants on both experimental and theoretical studies involving research areas from small clusters to extended molecular systems in the field.

  3. A Spectroscopic Determination of Scattering Lengths for Sodium Atom Collisions

    PubMed Central

    Tiesinga, Eite; Williams, Carl J.; Julienne, Paul S.; Jones, Kevin M.; Lett, Paul D.; Phillips, William D.

    1996-01-01

    We report a preliminary value for the zero magnetic field Na 2S(f = 1, m = − 1) + Na 2S(f = 1, m = − 1) scattering length, a1,−1. This parameter describes the low-energy elastic two-body processes in a dilute gas of composite bosons and determines, to a large extent, the macroscopic wavefunction of a Bose condensate in a trap. Our scattering length is obtained from photoassociative spectroscopy with samples of uncondensed atoms. The temperature of the atoms is sufficiently low that contributions from the three lowest partial waves dominate the spectrum. The observed lineshapes for the purely long-range 0g− molecular state enable us to establish key features of the ground state scattering wavefunction. The fortuitous occurrence of a p-wave node near the deepest point (Re = 72 a0) of the 0g− potential curve is instrumental in determining a1,−1 = (52 ± 5) a0 and a2,2 = (85 ± 3) a0, where the latter is for a collision of two Na 2S(f = 2, m = 2) atoms. PMID:27805104

  4. Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction

    ERIC Educational Resources Information Center

    Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.

    2009-01-01

    We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…

  5. Use of the Glauber approximation in atomic collisions - A progress report.

    NASA Technical Reports Server (NTRS)

    Gerjuoy, E.

    1972-01-01

    Recent progress in the use of the Glauber (1970) theory for estimating atomic collision cross sections is reviewed. It appears that the Glauber approximation is reliable for electron-hydrogen elastic scattering and excitation at incident energies exceeding 30 eV. For more complicated atomic collisions, the usefulness of the Glauber approximation has not yet been significantly tested.

  6. H type of hidden crossings in atomic collisions involving highly charged ions

    SciTech Connect

    Jakimovski, D.; Savichev, V.I.; Solovev, E.A. ||

    1996-10-01

    We examine the structure of the hidden crossings of the adiabatic potential curves {ital E}({ital R}) in the problem of two Coulomb centers with charges {ital Z}{sub 2} and {ital Z}{sub 1}, when {ital Z}{sub 2}{gt}{ital Z}{sub 1}. In this case we observe a new type of hidden crossing between the states ({ital n},{ital l},{ital m})-({ital n},{ital l}+1,{ital m}), where {ital n}, {ital l}, and {ital m} are the spherical quantum numbers of the united atom. This leads to the appearance of a mechanism of nonadiabatic transitions in hydrogen{emdash}multicharged ion collisions. As an example of this mechanism we present results of a calculation of inelastic transitions in O{sup 7+}(1{ital s})+H collisions. {copyright} {ital 1996 The American Physical Society.}

  7. The atomic hypothesis: physical consequences

    NASA Astrophysics Data System (ADS)

    Rivas, Martín

    2008-08-01

    The hypothesis that matter is made of some ultimate and indivisible objects, together with the restricted relativity principle, establishes a constraint on the kind of variables we are allowed to use for the variational description of elementary particles. We consider that the atomic hypothesis not only states the indivisibility of elementary particles, but also that these ultimate objects, if not annihilated, cannot be modified by any interaction so that all allowed states of an elementary particle are only kinematical modifications of any one of them. Therefore, an elementary particle cannot have excited states. In this way, the kinematical group of spacetime symmetries not only defines the symmetries of the system, but also the variables in terms of which the mathematical description of the elementary particles can be expressed in either the classical or the quantum mechanical description. When considering the interaction of two Dirac particles, the atomic hypothesis restricts the interaction Lagrangian to a kind of minimal coupling interaction.

  8. Physical Limits on Atomic Resolution

    NASA Astrophysics Data System (ADS)

    van Dyck, D.; van Aert, S.; den Dekker, A. J.

    2004-02-01

    It is shown that the ultimate resolution is not limited by the bandwidth of the microscope but by the bandwidth (i.e., the scattering power) of the object. In the case of a crystal oriented along a zone axis, the scattering is enhanced by the channeling of the electrons. However, if the object is aperiodic along the beam direction, the bandwidth is much more reduced. A particular challenge are the amorphous objects. For amorphous materials, the natural bandwidth is that of the single atom and of the order of 1 [Angstrom capital A, ring][minus sign]1, which can be reached with the present generation of medium voltage microscopes without aberration correctors. A clear distinction is made between resolving a structure and refining, that is, between resolution and precision. In the case of an amorphous structure, the natural bandwidth also puts a limit on the number of atom coordinates that can be refined quantitatively. As a consequence, amorphous structures cannot be determined from one projection, but only by using atomic resolution tomography. Finally a theory of experiment design is presented that can be used to predict the optimal experimental setting or the best instrumental improvement. Using this approach it is suggested that the study of amorphous objects should be done at low accelerating voltage with correction of both spherical and chromatic aberration.

  9. Electron emission in collisions between atoms and dressed projectiles

    NASA Astrophysics Data System (ADS)

    Mondal, A.; Ghosh, T. K.; Mandal, C. R.; Purkait, M.

    2016-12-01

    We present theoretical results for electron emission in collisions between helium atoms and dressed projectiles at high energies. Double-differential cross sections (DDCSs) as a function of the emitted electron energies and angles are calculated. In our study we have applied the three-body formalism using the three-Coulomb wave (3CW-3B) model. The interaction between the dressed projectile and the active electron in the target has been approximated by a model potential having both a long-range Coulomb potential part and a short-range part. However, the active electron in the target has been treated as hydrogenic. We have also studied the projectile charge state dependence of the DDCS. Our theoretical results are compared with available experimental data as well as other theoretical calculations. The comparison shows a good agreement between the present calculations and the measurements. The obtained results are also compatible with other theoretical findings.

  10. Thermal relaxation of molecular oxygen in collisions with nitrogen atoms.

    PubMed

    Andrienko, Daniil A; Boyd, Iain D

    2016-07-07

    Investigation of O2-N collisions is performed by means of the quasi-classical trajectory method on the two lowest ab initio potential energy surfaces at temperatures relevant to hypersonic flows. A complete set of bound-bound and bound-free transition rates is obtained for each precollisional rovibrational state. Special attention is paid to the vibrational and rotational relaxations of oxygen as a result of chemically non-reactive interaction with nitrogen atoms. The vibrational relaxation of oxygen partially occurs via the formation of an intermediate NO2 complex. The efficient energy randomization results in rapid vibrational relaxation at low temperatures, compared to other molecular systems with a purely repulsive potential. The vibrational relaxation time, computed by means of master equation studies, is nearly an order of magnitude lower than the relaxation time in N2-O collisions. The rotational nonequilibrium starts to play a significant effect at translational temperatures above 8000 K. The present work provides convenient relations for the vibrational and rotational relaxation times as well as for the quasi-steady dissociation rate coefficient and thus fills a gap in data due to a lack of experimental measurements for this system.

  11. Numerical calculation of ionization in fast ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Horbatsch, Marko; Chassid, Michal

    1996-05-01

    Numerical solutions of the time-dependent Schrödinger equation in a 1D model and in a realistic 3D setting^1,2 are analyzed to calculate excitation probabilities and differential electron emission probabilities for collisions of fast bare projectiles with hydrogen atoms. The results are tested for the expected scaling behaviour with projectile charge and collision energy. The ionization probabilities are calculated by first projecting out the bound-state contributions from the time-evolved wavefunction and then performing a discrete Fourier transform. Comparison is provided with recent experiments for helium targets using cold target recoil ion momentum spectroscopy^3. For fast (v=12 au) and highly charged projectiles (Z_p=24) bound-state excitations are dominantly produced at much larger impact parameters than b >= 3 au for which the ionization channel receives its largest contribution. ^1 M. Horbatsch, Phys. Rev. A 44, R5346 (1991) ^2 M. Chassid and M. Horbatsch, J. Phys. B 28,L621 (1995) ^3 R. Moshammer, J. Ullrich, et. al. Phys. Rev. Lett. 73, 3371 (1994).

  12. Thermal relaxation of molecular oxygen in collisions with nitrogen atoms

    NASA Astrophysics Data System (ADS)

    Andrienko, Daniil A.; Boyd, Iain D.

    2016-07-01

    Investigation of O2-N collisions is performed by means of the quasi-classical trajectory method on the two lowest ab initio potential energy surfaces at temperatures relevant to hypersonic flows. A complete set of bound-bound and bound-free transition rates is obtained for each precollisional rovibrational state. Special attention is paid to the vibrational and rotational relaxations of oxygen as a result of chemically non-reactive interaction with nitrogen atoms. The vibrational relaxation of oxygen partially occurs via the formation of an intermediate NO2 complex. The efficient energy randomization results in rapid vibrational relaxation at low temperatures, compared to other molecular systems with a purely repulsive potential. The vibrational relaxation time, computed by means of master equation studies, is nearly an order of magnitude lower than the relaxation time in N2-O collisions. The rotational nonequilibrium starts to play a significant effect at translational temperatures above 8000 K. The present work provides convenient relations for the vibrational and rotational relaxation times as well as for the quasi-steady dissociation rate coefficient and thus fills a gap in data due to a lack of experimental measurements for this system.

  13. Atoms-for-Peace: A Galactic Collision in Action

    NASA Astrophysics Data System (ADS)

    2010-11-01

    European Southern Observatory astronomers have produced a spectacular new image of the famous Atoms-for-Peace galaxy (NGC 7252). This galactic pile-up, formed by the collision of two galaxies, provides an excellent opportunity for astronomers to study how mergers affect the evolution of the Universe. Atoms-for-Peace is the curious name given to a pair of interacting and merging galaxies that lie around 220 million light-years away in the constellation of Aquarius. It is also known as NGC 7252 and Arp 226 and is just bright enough to be seen by amateur astronomers as a very faint small fuzzy blob. This very deep image was produced by ESO's Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. A galaxy collision is one of the most important processes influencing how our Universe evolves, and studying them reveals important clues about galactic ancestry. Luckily, such collisions are long drawn-out events that last hundreds of millions of years, giving astronomers plenty of time to observe them. This picture of Atoms-for-Peace represents a snapshot of its collision, with the chaos in full flow, set against a rich backdrop of distant galaxies. The results of the intricate interplay of gravitational interactions can be seen in the shapes of the tails made from streams of stars, gas and dust. The image also shows the incredible shells that formed as gas and stars were ripped out of the colliding galaxies and wrapped around their joint core. While much material was ejected into space, other regions were compressed, sparking bursts of star formation. The result was the formation of hundreds of very young star clusters, around 50 to 500 million years old, which are speculated to be the progenitors of globular clusters. Atoms-for-Peace may be a harbinger of our own galaxy's fate. Astronomers predict that in three or four billion years the Milky Way and the Andromeda Galaxy will collide, much as has happened with Atoms-for-Peace. But don

  14. Excitation of hydrogen atoms in collisions with helium atoms: the role of electron–electron interaction

    NASA Astrophysics Data System (ADS)

    Frémont, F.; Belyaev, A. K.

    2017-02-01

    Cross sections for producing H(nl) excited state atoms in H(1s) + He(1s2) collisions are calculated using the CTMC method, at impact energies ranging from 20 eV to 100 keV. The role of the electron correlation is studied. In the first step, the interactions between each pair of the three electrons are neglected. This leads to disagreement of the calculated total cross section for producing H(2l) atoms with previous experimental and theoretical results. In a second step, the electron–electron interaction is taken into account in a rigorous way, that is, in the form of the pure Coulomb potential. To make sure that the He target is stable before the collision, phenomenological potentials for the electron–helium-nucleus interactions that simulate the Heisenberg principle are included in addition to the Coulomb potential. The excitation cross section calculated in the frame of this model is in remarkable agreement with previous data in the range between 200 eV and 5 keV. At other energies, discrepancies are revealed, but only by a factor of less than 2 at high energies. The present results show the decisive role of the electron–electron interaction during collisions. In addition, they demonstrate the ability of classical mechanics to take into account the effects of the electron correlation.

  15. The Atomic and Nuclear Physics of Atomic EDMs

    NASA Astrophysics Data System (ADS)

    Chupp, Timothy

    2016-09-01

    Atomic Electric-Dipole-Moment (EDM) measurements employ low-energy atomic and precision-measurement techniques to measure the effects of elementary particle forces that affect the distribution of charge and mass in the nucleus, which is probed by the atomic electrons. Experiments and their interpretation strongly overlap atomic and nuclear physics in the experimental and theoretical problems presented. On the experimental side, the atomic EDM couples to electric fields while the magnetic dipole moment couples to magnetic fields requiring exquisite control and characerization of the magnetic fields. Measuring the tiny frequency shifts requires clock-comparisons and a large signal-to-noise ratio for frequency resolution much smaller than the linewidths, which are lmitied by observation times. To address the experimental challenges, I will discuss systematic effects related to magnetic fields and techniques of magnetometry and co-magntometery as well as optical pumping and related techniques that enhance signal-to-noise. I will also address the interpretation of atomic EDMs in terms of a set of low-energy parameters that relate to effective-field-theory coefficients, and I will empshaize the need for improved calculations from both atomic-theory and nuclear theory.

  16. Toward a Physical Characterization of Raindrop Collision Outcome Regimes

    NASA Technical Reports Server (NTRS)

    Testik, F. Y.; Barros, Ana P.; Bilven, Francis L.

    2011-01-01

    A comprehensive raindrop collision outcome regime diagram that delineates the physical conditions associated with the outcome regimes (i.e., bounce, coalescence, and different breakup types) of binary raindrop collisions is proposed. The proposed diagram builds on a theoretical regime diagram defined in the phase space of collision Weber numbers We and the drop diameter ratio p by including critical angle of impact considerations. In this study, the theoretical regime diagram is first evaluated against a comprehensive dataset for drop collision experiments representative of raindrop collisions in nature. Subsequently, the theoretical regime diagram is modified to explicitly describe the dominant regimes of raindrop interactions in (We, p) by delineating the physical conditions necessary for the occurrence of distinct types of collision-induced breakup (neck/filament, sheet, disk, and crown breakups) based on critical angle of impact consideration. Crown breakup is a subtype of disk breakup for lower collision kinetic energy that presents distinctive morphology. Finally, the experimental results are analyzed in the context of the comprehensive collision regime diagram, and conditional probabilities that can be used in the parameterization of breakup kernels in stochastic models of raindrop dynamics are provided.

  17. Atomic displacement in solids: analysis of the primary event and the collision cascade. Part I: Neutron and positive ion irradiation

    NASA Astrophysics Data System (ADS)

    de Almeida, P.; Räisänen, J.

    2005-05-01

    A modern, mathematical-physics introduction to the analytical problem of atomic displacement in solids which is both technically adequate and relevant to an introductory graduate students' curriculum in radiation damage theory is reported. The problematic of atomic displacement in solids is introduced didactically, deriving first the primary event (that is, the formation of the primary knock-on atom) and then building on that specific set of results in order to extend their basics to secondary, tertiary and higher-order progeny—the collision cascade—for both neutrons and positive ions, namely, their average damage functions, displacement cross-sections and energy spectra. A comparison of atomic displacement in solids under neutron and positive ion irradiation is discussed in terms of the physical concept of concentration of displaced atoms (or displacement dose).

  18. Energy and angular distributions of detached electrons in a solvable model of ion-atom collisions

    SciTech Connect

    Macek, J.H.; Ovchinnikov, S.Y. |; Solovev, E.A.

    1999-08-01

    Electron energy and angular distributions are computed for a model of atom{endash}negative-ion collisions. In this model, electron-atom interactions are represented by zero-range potentials in an approximation where two identical atoms move along straight-line classical trajectories in head-on collisions. Analytic expressions for the ionization amplitudes are interpreted in terms of Sturmian eigenvalues and eigenfunctions. At high velocity, the computed distributions exhibit direct excitation and continuum capture cusps in addition to the binary encounter ridge. At low velocities, a single feature corresponding to an electron distribution centered midway between the target and projectile emerges. For initial conditions corresponding to gerade symmetry a single broad peak appears, while for ungerade symmetry there is a node at the midpoint so that the peak splits into two parts. It is confirmed that the advanced adiabatic approximation gives an accurate description of the ungerade distribution at low and intermediate velocities. {copyright} {ital 1999} {ital The American Physical Society}

  19. Energy and angular distributions of detached electrons in a solvable model of ion-atom collisions

    SciTech Connect

    Macek, J.H.; Ovchinnikov, S.Y. Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 ); Solovev, E.A. )

    1999-08-01

    Electron energy and angular distributions are computed for a model of atom[endash]negative-ion collisions. In this model, electron-atom interactions are represented by zero-range potentials in an approximation where two identical atoms move along straight-line classical trajectories in head-on collisions. Analytic expressions for the ionization amplitudes are interpreted in terms of Sturmian eigenvalues and eigenfunctions. At high velocity, the computed distributions exhibit direct excitation and continuum capture cusps in addition to the binary encounter ridge. At low velocities, a single feature corresponding to an electron distribution centered midway between the target and projectile emerges. For initial conditions corresponding to gerade symmetry a single broad peak appears, while for ungerade symmetry there is a node at the midpoint so that the peak splits into two parts. It is confirmed that the advanced adiabatic approximation gives an accurate description of the ungerade distribution at low and intermediate velocities. [copyright] [ital 1999] [ital The American Physical Society

  20. Atomic physics with highly charged ions: Progress report, 15 August 1985--14 August 1988

    SciTech Connect

    Richard, P.

    1988-08-01

    The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project ''Atomic Physics with Highly Charged Ions'' speaks to these points. The experimental work is made possible locally by the use of relatively high velocity, highly charged projectiles (v typically 5% c) as obtained from the 6 MV tandem Van de Graaff accelerator. The work in the past few years has divided into collisions at high velocity using the primary beams from the accelerator and collisions at low velocity using secondary beams (recoil ions produced in a high velocity collision) in a so-called SIRS (Secondary Ion Recoil Source) geometry. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x-rays and Auger electrons. Correlation effects and polarization phenomena in ion-atom collisions have been investigated.

  1. PREFACE: XXVII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011)

    NASA Astrophysics Data System (ADS)

    Williams, I. D.; van der Hart, H. W.; McCann, J. F.; Crothers, D. S. F.

    2012-11-01

    The XXVII International Conference on Photonic, Electronic and Atomic Collisions was held at Queen's University Belfast, Northern Ireland, 27 July - 2 August 2011. Members of the Local Organising Committee were drawn from the School of Mathematics and Physics of Queen's University Belfast, the School of Physical Sciences at Dublin City University, the School of Physics at University College Dublin and the Department of Experimental Physics at the National University of Ireland, Maynooth. The Conference was attended by 566 participants with contributions from 54 countries. The meeting attracted 786 contributed papers for presentation in the poster sessions. The conference included 20 Special Reports selected from the contributed papers, and these are included in part 1 of this volume. During the meeting a total of 65 Progress Reports were also presented, and the authors invited to submit written versions of their talks (see Part 1). Of the total number of contributed papers, 663 are included as refereed abstracts in parts 2 to 15 of this volume of Journal of Physics: Conference Series. Part 1 of this volume includes detailed write-ups of the majority of plenary lectures, progress reports and special reports, constituting a comprehensive tangible record of the meeting, and is additionally published in hard-copy as the Conference Proceedings. There were 5 plenary lectures given by Margaret Murnane on Ultrafast processes in atomic dynamics; Chris Greene on Few-body highly-correlated dynamics; Michael Allan on Electron-molecule collisions; Yasunori Yamazaki on Antiproton and positron collisions and Thomas Stöhlker on Relativistic ion collisions. Ian Spielman, winner of the IUPAP Young Scientist Prize for 2011, gave a special lecture entitled Modifying interatomic interactions using Raman coupling: a tale of slowly colliding Bose-Einstein condensates. In addition an evening public lecture by Mike Baillie on How precise tree-ring dating raises issues concerning the

  2. Atomic Structure Calculations from the Los Alamos Atomic Physics Codes

    DOE Data Explorer

    Cowan, R. D.

    The well known Hartree-Fock method of R.D. Cowan, developed at Los Alamos National Laboratory, is used for the atomic structure calculations. Electron impact excitation cross sections are calculated using either the distorted wave approximation (DWA) or the first order many body theory (FOMBT). Electron impact ionization cross sections can be calculated using the scaled hydrogenic method developed by Sampson and co-workers, the binary encounter method or the distorted wave method. Photoionization cross sections and, where appropriate, autoionizations are also calculated. Original manuals for the atomic structure code, the collisional excitation code, and the ionization code, are available from this website. Using the specialized interface, you will be able to define the ionization stage of an element and pick the initial and final configurations. You will be led through a series of web pages ending with a display of results in the form of cross sections, collision strengths or rates coefficients. Results are available in tabular and graphic form.

  3. Investigation of low temperature atomic hydrogen spin-exchange collisions using a cryogenic hydrogen maser

    SciTech Connect

    Walsworth, R.L.; Mattison, E.M.; Vessot, R.F.C.; Silvera, I.F.

    1993-05-01

    We have used a cryogenic hydrogen maser to study ground state atomic hydrogen spin-exchange collisions at temperatures near 0.5 K. Recent quantum-mechanical treatments of low energy atomic collisions predict that hyperfine-induced spin-exchange frequency shifts will become large at low temperatures, and will affect the performance of new atomic frequency standards such as the cryogenic hydrogen maser and the cesium fountain. We have measured the effects of low temperature spin-exchange collisions on maser line-broadening and frequency, and in particular the hyperfine-induced frequency shift.

  4. Potential Energy Curves and Collisions Integrals of Air Components. 2; Interactions Involving Ionized Atoms

    NASA Technical Reports Server (NTRS)

    Stallcop, James R.; Partridge, Harry; Levin, Eugene; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    Collision integrals are fundamental quantities required to determine the transport properties of the environment surrounding aerospace vehicles in the upper atmosphere. These collision integrals can be determined as a function of temperature from the potential energy curves describing the atomic and molecular collisions. Ab initio calculations provide a practical method of computing the required interaction potentials. In this work we will discuss recent advances in scattering calculations with an emphasis on the accuracy that is obtainable. Results for interactions of the atoms and ionized atoms of nitrogen and oxygen will be reviewed and their application to the determination of transport properties, such as diffusion and viscosity coefficients, will be examined.

  5. 3He: cosmological and atomic physics experiments.

    PubMed

    Bunkov, Yuriy M

    2008-08-28

    Because the superfluid 3He order parameter exhibits many similarities with that of our Universe, the superfluid condensate may be considered as a quantum vacuum that carries various types of quasiparticles and topological defects. The condensate thus provides a test system for the experimental investigation of many general physics problems in cosmology, atomic or nuclear physics that are otherwise difficult or even impossible to investigate experimentally.

  6. Atomic and molecular physics at LURE

    SciTech Connect

    Morin, P. |

    1994-08-01

    A short overview of the present research activity at LURE is given, in the field of atomic and molecular physics. Three selected examples are discussed in more detail and the {open_quotes}SOLEIL{close_quotes} project of a new French synchrotron facility is presented.

  7. Correlated charge-changing ion-atom collisions. Progress report, February 16, 1990--February 15, 1993

    SciTech Connect

    Tanis, J.A.

    1993-02-01

    This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from February 16, 1990 through February 15, 1993. This work involves the experimental investigation of atomic interactions in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron-correlation effects. The processes studied are of interest both from fundamental and applied points of view. In the latter case, results are obtained which are relevant to the understanding of laboratory and astrophysical plasmas, highly-excited (Rydberg) and continuum states of atoms and ions, atomic structure effects, the interaction of ions with surfaces, and the development of heavy-ion storage-rings. The results obtained have provided the basis for several M.A. thesis projects at Western Michigan and several Ph.D. dissertation projects are currently underway. Summaries of work completed and work in progress are given below in Section II. This research has resulted in 26 papers (in print and in press), 12 invited presentations at national and international meetings, and 28 contributed presentations as detailed in Section III.

  8. Head-on Collisions of Xe Atoms Against Superfluid ^4 He Nanodroplets

    NASA Astrophysics Data System (ADS)

    Coppens, François; Leal, Antonio; Barranco, Manuel; Halberstadt, Nadine; Pi, Marti

    2016-11-01

    We study the head-on collision of a heliophilic xenon atom with a superfluid ^4 He droplet made of 1000 atoms. At variance with the findings for a heliophobic cesium atom of a similar atomic weight, it is found that the xenon atom has to hit the droplet with a large kinetic energy in order to get across it without being captured. When it is not captured, the xenon impurity does not emerge as a bare atom; instead, due to its heliophilic character it carries away some helium atoms.

  9. Atomic physics processes in radial transport calculations

    SciTech Connect

    Hogan, J.T.

    1983-02-01

    These lectures were intended as preparation for detailed discussions of the role of atomic and molecular physics in confinement research at the 1982 NATO Advanced Study Institute. They begin with a description of the major approaches to magnetic confinement: tandem (ambipolar) mirrors with their associated auxiliary barriers, tokamaks, and stellarators. The leading alternatives, the ELMO Bumpy Torus and the reversed field pinch, are also treated. The evolution equations for particle, energy, and (where relevant) field diffusion are presented and discussed. This is the context for atomic and molecular processes relevant to confinement.

  10. Many-body physics using cold atoms

    NASA Astrophysics Data System (ADS)

    Sundar, Bhuvanesh

    Advances in experiments on dilute ultracold atomic gases have given us access to highly tunable quantum systems. In particular, there have been substantial improvements in achieving different kinds of interaction between atoms. As a result, utracold atomic gases oer an ideal platform to simulate many-body phenomena in condensed matter physics, and engineer other novel phenomena that are a result of the exotic interactions produced between atoms. In this dissertation, I present a series of studies that explore the physics of dilute ultracold atomic gases in different settings. In each setting, I explore a different form of the inter-particle interaction. Motivated by experiments which induce artificial spin-orbit coupling for cold fermions, I explore this system in my first project. In this project, I propose a method to perform universal quantum computation using the excitations of interacting spin-orbit coupled fermions, in which effective p-wave interactions lead to the formation of a topological superfluid. Motivated by experiments which explore the physics of exotic interactions between atoms trapped inside optical cavities, I explore this system in a second project. I calculate the phase diagram of lattice bosons trapped in an optical cavity, where the cavity modes mediates effective global range checkerboard interactions between the atoms. I compare this phase diagram with one that was recently measured experimentally. In two other projects, I explore quantum simulation of condensed matter phenomena due to spin-dependent interactions between particles. I propose a method to produce tunable spin-dependent interactions between atoms, using an optical Feshbach resonance. In one project, I use these spin-dependent interactions in an ultracold Bose-Fermi system, and propose a method to produce the Kondo model. I propose an experiment to directly observe the Kondo effect in this system. In another project, I propose using lattice bosons with a large hyperfine spin

  11. The physics of proton antiproton collisions

    SciTech Connect

    Shochet, M. )

    1991-12-03

    This paper contains information information on: accelerator and detector; QCD studies; studies of the electroweak force; The search for the top quark; {beta} physics at hadron colliders; and the search for exotic objects and prospects for the future.

  12. Cold Atoms, Statistical Physics and Quantum Simulations

    DTIC Science & Technology

    2010-07-22

    to be the development of robust theoretical techniques for the simulations of ultra-cold Bose gases and other quantum phenomena, such theoretical...finite-temperature effects in atom-chip interferometry of Bose -Einstein condensates, R. G. Scott, et al., Physical Review A, 063624 (2009). A copy of...March 2009. Mr Hodder was supported through a University of Otago Scholarship. He initially developed a simple single-site Hubbard model, which can be

  13. Time-of-Flight Experiments in Molecular Motion and Electron-Atom Collision Kinematics

    ERIC Educational Resources Information Center

    Donnelly, Denis P.; And Others

    1971-01-01

    Describes a set of experiments for an undergraduate laboratory which demonstrates the relationship between velocity, mass, and temperature in a gas. The experimental method involves time-of-flight measurements on atoms excited to metastable states by electron impact. Effects resulting from recoil in the electron-atom collision can also be…

  14. A spectroscopic study of hydrogen atom and molecule collision. Final report

    SciTech Connect

    Kielkopf, John F.

    2002-07-01

    The fundamental processes which occur in low-energy collisions of excited states of the hydrogen atom with other neutral atoms, protons, and electrons in dense plasmas were investigated in this project. Theoretical and experimental results for the Lyman and Balmer series are described here, including references to recent publications resulting from this project.

  15. PREFACE: XXVIII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2013)

    NASA Astrophysics Data System (ADS)

    Xiao, Guoqing; Cai, Xiaohong; Ding, Dajun; Ma, Xinwen; Zhao, Yongtao

    2014-04-01

    The 28th International Conference on Photonic, Electronic and Atomic Collisions (XXVIII ICPEAC) was held by the Institute of Modern Physics, Chinese Academy of Sciences (IMP) on 24-30 July, 2013 in Lanzhou, China. The 444 conference participants came from 37 countries and/or regions. Five plenary lectures, more than 80 progress reports and special reports had been arranged according to the decision of the ICPEAC International General Committee. Meanwhile, more than 650 abstracts were selected as poster presentations. Before the conference, three highly distinguished scientists, Professor Joachim Burgdöorfer, Professor Hossein Sadeghpour and Professor Yasunori Yamazaki, presented tutorial lectures with the support of the IMP Branch of Youth Innovation Promotion Association, CAS (IMP-YIPA). During the conference, Professor Jianwei Pan from University of Sciences and Technology in China presented an enlightening public lecture on quantum communication. Furthermore, 2013 IUPAP Young Scientist Prize was awarded to Dr T Jahnke from Johann Wolfgang Goethe University of Germany. The Sheldon Datz Prize for an Outstanding Young Scientist Attending ICPEAC was awarded to Dr Diogo Almeida from University of Fribourg of Switzerland. As a biannual academic conference, ICPEAC is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, atomic, ionic, molecular, cluster collisions with matter. With a history back to 1958, ICPEAC came to China for the very first time. IMP has been preparing the conference six years before, ever since the ICPEAC International General Committee made the decision to hold the XXVIII ICPEAC in Lanzhou. This proceedings includes the papers of the two plenary lectures, 40 progress reports, 17 special reports and 337 posters, which were reviewed and revised according to the comments of the referees. The Local Organizing Committee would like to

  16. Handbook explaining the fundamentals of nuclear and atomic physics

    NASA Technical Reports Server (NTRS)

    Hanlen, D. F.; Morse, W. J.

    1969-01-01

    Indoctrination document presents nuclear, reactor, and atomic physics in an easy, straightforward manner. The entire subject of nuclear physics including atomic structure ionization, isotopes, radioactivity, and reactor dynamics is discussed.

  17. Quantum diffraction effects on the atomic polarization collision in partially ionized dense plasmas

    SciTech Connect

    Jung, Young-Dae

    2014-04-15

    The influence of quantum diffraction on the electron-atom polarization collision process is investigated in partially ionized dense plasmas. The pseudopotential model and eikonal method are employed to obtain the eikonal phase shift and eikonal cross section as functions of the impact parameter, collision energy, Debye length, electron de Broglie wavelength, and atomic polarizability. The results show that the eikonal phase shift for the electron-hydrogen atom polarization collision decreases with an increase of the electron de Broglie wavelength. It is important to note that the influence of quantum diffraction produces the repulsive part in the electron-atom polarization interaction. It is also found that the quantum diffraction effect enhances the differential eikonal cross section. Additionally, the total eikonal cross section decreases with increasing electron de Broglie wavelength. The variations of the eikonal cross section due to the influence of finite size of the de Broglie wavelength and Debye radius are also discussed.

  18. Atomic physics with vapor-cell clocks

    NASA Astrophysics Data System (ADS)

    McGuyer, Bart Hunter

    The most widely used atomic frequency standards (or clocks) are based on the microwave resonant frequencies of optically pumped vapors of alkali-metal atoms in glass cells filled with buffer gas. These vapor-cell clocks are secondary, not primary frequency standards mainly because of the light and pressure shifts, which alter the resonant frequencies of the alkali-metal atoms. This dissertation presents studies of atomic physics important to vapor-cell clocks and, in particular, their accuracy. First, we report a simple method to suppress the light shift in optical pumping systems. This method uses only frequency modulation of a radio frequency or microwave source, which excites an atomic resonance, to simultaneously lock the source frequency to the atomic resonance and lock the pumping light frequency to suppress the light shift. This technique can be applied to many optical pumping systems that experience light shifts. It is especially useful for atomic clocks because it improves the long-term performance, reduces the influence of a pumping laser, and requires less equipment than previous methods. Next, we present three studies of the pressure shift, starting with an estimation of the hyperfine-shift potential that is responsible for most of the pressure shift. We then show that the microwave resonant frequencies of ground-state Rb and Cs atoms in Xe buffer gas have a relatively large nonlinear dependence on the Xe pressure, presumably because of short-lived RbXe and CsXe van der Waals molecules. The Xe data show striking discrepancies with the previous theory for nonlinear shifts, most of which is eliminated by accounting for the spin-rotation interaction in addition to the hyperfine-shift interaction in the molecules. To the limit of our experimental accuracy, the shifts of Rb and Cs in He, Ne, and N2 were linear with pressure. We then consider the prospects for suppressing the pressure shift with buffer-gas mixtures and feedback. Finally, we report an

  19. Theoretical Studies Relating to the Interaction of Radiation with Matter: Atomic Collision Processes Occurring in the Presence of Radiation Fields

    DTIC Science & Technology

    1981-09-01

    Two-Level System, Aromic Coherence, Zeeman Coherence, Dressed-Atom Picture, Degenerate Four -Wave Mixing. S20 ABSTRACT (Continue on reverse, *Ida If...Coherences: (S) Effects of Collisions on Zeeman Coherences (1r) Collision Effects in Degenerate- Four -Wave-Mixing, ~ (5) Dressed-Atom Picture in Laser...Effects of collisions on Zeeman coherences, (4) Colision effects in degenerate- four -wave-mixing, and (5) Dressed-atom picture in laser spectroscopy. 1. Two

  20. Thermalization of fast cesium 5D{sub 3sol2} atoms in collisions with ground-state cesium atoms

    SciTech Connect

    Marks, A.; Hickman, A. P.; Huennekens, J.; Streater, A. D.

    2005-01-01

    We have investigated collisions involving fast, excited Cs atoms produced by photodissociating Cs{sub 2} molecules with a pulsed dye laser. The velocities of the atoms in the 5D state formed by the process Cs{sub 2}(X {sup 1}{sigma}{sub g}{sup +})+({Dirac_h}/2{pi}){omega}{sub pump}{yields}Cs{sub 2}{sup *}{yields}Cs(5D)+Cs(6S) are much greater than typical thermal velocities associated with the cell temperature. Using a narrow-band cw probe laser to observe the increased Doppler broadening of the 5D{sub 3/2}{yields}5F{sub 5/2} excitation line shape, we are able to monitor the time evolution of the velocity distribution of these 5D atoms. We analyze the data using a model that predicts the time-dependent excitation line shape of the fast atoms. Because the photons used to dissociate the molecules have a well-defined energy, the velocity distribution of the excited atoms in the early time after they are produced can be fairly well determined. Over time, velocity-changing collisions with ground-state Cs atoms cause the velocity distribution of excited atoms to approach the thermal limit. An analysis based on the strong-collision model leads to a prediction that the observed line shape at intermediate times will be a linear combination of contributions from distinct 'fast' and 'thermalized' atomic populations. By fitting our data to this model, a rate coefficient for velocity-changing collisions of fast Cs(5D{sub 3/2}) atoms with ground-state Cs atoms has been determined. The result k{sub VCC}=(6.1{+-}1.2)x10{sup -10} cm{sup 3} s{sup -1} corresponds to an effective velocity-changing collision cross section of {sigma}{sub VCC}{sup Cs,eff}=(1.2{+-}0.2)x10{sup -14} cm{sup 2}.

  1. V. S. Lebedev and I. L. Beigman, Physics of Highly Excited Atoms and Ions

    NASA Astrophysics Data System (ADS)

    Mewe, R.

    1999-07-01

    This book contains a comprehensive description of the basic principles of the theoretical spectroscopy and experimental spectroscopic diagnostics of Rydberg atoms and ions, i.e., atoms in highly excited states with a very large principal quantum number (n≫1). Rydberg atoms are characterized by a number of peculiar physical properties as compared to atoms in the ground or a low excited state. They have a very small ionization potential (∝1/n2), the highly excited electron has a small orbital velocity (∝1/n), the radius (∝n2) is very large, the excited electron has a long orbital period (∝n3), and the radiation lifetime is very long (∝n3-5). At the same time the R. atom is very sensitive to perturbations from external fields in collisions with charged and neutral targets. In recent years, R. atoms have been observed in laboratory and cosmic conditions for n up to ˜1000, which means that the size amounts to about 0.1 mm, ˜106 times that of an atom in the ground state. The scope of this monograph is to familiarize the reader with today's approaches and methods for describing isolated R. atoms and ions, radiative transitions between highly excited states, and photoionization and photorecombination processes. The authors present a number of efficient methods for describing the structure and properties of R. atoms and calculating processes of collisions with neutral and charged particles as well as spectral-line broadening and shift of Rydberg atomic series in gases, cool and hot plasmas in laboratories and in astrophysical sources. Particular attention is paid to a comparison of theoretical results with available experimental data. The book contains 9 chapters. Chapter 1 gives an introduction to the basic properties of R. atoms (ions), Chapter 2 is devoted to an account of general methods describing an isolated Rydberg atom. Chapter 3 is focussed on the recent achievements in calculations of form factors and dipole matrix elements of different types of

  2. High charge state, ion-atom collision experiments using accel-decel

    SciTech Connect

    Bernstein, E.M.; Clark, M.W.; Tanis, J.A.; Graham, W.G.

    1987-01-01

    Recent studies of /sub 16/S/sup 13 +/ + He collisions between 2.5 and 200 MeV, which were made using the accel-decel technique with the Brookhaven National Laboratory coupled MP tandem Van de Graaff accelerators, are discussed. Cross sections were measured for single electron-capture and -loss as well as K x rays correlated to electron-capture. Other planned ion-atom collision experiments requiring accel-decel are also presented. 18 refs., 3 figs.

  3. Time-dependent density functional theory Ehrenfest dynamics: collisions between atomic oxygen and graphite clusters.

    PubMed

    Isborn, Christine M; Li, Xiaosong; Tully, John C

    2007-04-07

    An ab initio direct Ehrenfest dynamics method with time-dependent density functional theory is introduced and applied to collisions of 5 eV oxygen atoms and ions with graphite clusters. Collisions at three different sites are simulated. Kinetic energy transfer from the atomic oxygen to graphite local vibrations is observed and electron-nuclear coupling resulting in electronic excitation within the graphite surface as well as alteration of the atomic charge is first reported in this paper. The three oxygen species studied, O(3P), O-(2P), and O+(4S), deposit different amounts of energy to the surface, with the highest degree of damage to the pi conjugation of the cluster produced by the atomic oxygen cation. Memory of the initial charge state is not lost as the atom approaches, in contrast to the usual assumption.

  4. Quasiclassical trajectory study of fast H-atom collisions with acetylene.

    PubMed

    Han, Yong-Chang; Sharma, Amit R; Bowman, Joel M

    2012-06-07

    Translationally hot H collisions with the acetylene are investigated using quasiclassical trajectory calculations, on a recent full-dimensional ab initio-based potential energy surface. Three outcomes are focused on: non-reactive energy transfer via prompt collisions, non-reactive energy transfer via the formation of the vinyl complex, and reactive chemical H-atom exchange, also via complex formation. The details of these outcomes are presented and correlated with the collision lifetime. Large energy transfer is found via complex formation, which can subsequently decay back to reactants, a non-reactive event, or to new products, a reactive event. For the present system, these two events are experimentally indistinguishable.

  5. State selective Rydberg charge transfer and ionization in low energy ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Perumal, A. N.; Tripathi, D. N.

    1998-10-01

    The Classical Trajectory Monte Carlo (CTMC) simulation method with a core modified interaction potential has been used to study the single charge transfer in Na +and Ar + ions colliding with a variety of state selected Na Rydberg atom targets ( n=24, 28, 33, 40 and l=2) in the reduced velocity region v=0.2-2.0. The experimentally observed structures in the total capture cross section versus reduced velocity curves are reproduced by CTMC method. The n-distribution of final capture state has got two peaks viz. first one at nf= ni and the second one at a higher nf depending on the initial angular momentum in the velocity regime 0.4-0.6. These structures have been explained in terms of quasimolecular-ion formation and a classical model proposed by Roy et al. (B.N. Roy, D.N. Tripathi, D.K. Rai, Phys. Rev. A 5 (1972) 1252). The CTMC ionization cross section results are benchmarked with the recent experimental measurement of Makarov et al. (O.P. Makarov, D.M. Homan, O.P. Sorokina, K.B. MacAdam, in: F. Aumayr, G. Betz, H.P. Winter (Eds.), Proceedings of the 20th International Conference on the Physics of Electronics and Atomic Collisions, Vienna, 1997, p. FR052) for Na +-Na(24 d).

  6. Energy loss straggling in collisions of fast finite-size ions with atoms

    NASA Astrophysics Data System (ADS)

    Makarov, D. N.; Matveev, V. I.

    2013-03-01

    The influence of ion size on straggling of energy losses by fast partially stripped ions is studied using the nonperturbative approach based on the eikonal approximation. It is shown that such a consideration of collisions of ions with complex atoms can lead to considerable corrections in calculating root-mean-square straggling of energy losses by fast ions compared to the results obtained for point ions. The root-mean-square straggling of energy losses are calculated for bromide and iodine ions in collisions with copper, silver, and aluminum atoms. It is shown that allowance for the size of the electron "coat" of an ion noticeably improves the agreement with experimental data.

  7. Energy loss straggling in collisions of fast finite-size ions with atoms

    SciTech Connect

    Makarov, D. N. Matveev, V. I.

    2013-03-15

    The influence of ion size on straggling of energy losses by fast partially stripped ions is studied using the nonperturbative approach based on the eikonal approximation. It is shown that such a consideration of collisions of ions with complex atoms can lead to considerable corrections in calculating root-mean-square straggling of energy losses by fast ions compared to the results obtained for point ions. The root-mean-square straggling of energy losses are calculated for bromide and iodine ions in collisions with copper, silver, and aluminum atoms. It is shown that allowance for the size of the electron 'coat' of an ion noticeably improves the agreement with experimental data.

  8. The Los Alamos suite of relativistic atomic physics codes

    DOE PAGES

    Fontes, C. J.; Zhang, H. L.; Jr, J. Abdallah; ...

    2015-05-28

    The Los Alamos SuitE of Relativistic (LASER) atomic physics codes is a robust, mature platform that has been used to model highly charged ions in a variety of ways. The suite includes capabilities for calculating data related to fundamental atomic structure, as well as the processes of photoexcitation, electron-impact excitation and ionization, photoionization and autoionization within a consistent framework. These data can be of a basic nature, such as cross sections and collision strengths, which are useful in making predictions that can be compared with experiments to test fundamental theories of highly charged ions, such as quantum electrodynamics. The suitemore » can also be used to generate detailed models of energy levels and rate coefficients, and to apply them in the collisional-radiative modeling of plasmas over a wide range of conditions. Such modeling is useful, for example, in the interpretation of spectra generated by a variety of plasmas. In this work, we provide a brief overview of the capabilities within the Los Alamos relativistic suite along with some examples of its application to the modeling of highly charged ions.« less

  9. The Los Alamos suite of relativistic atomic physics codes

    SciTech Connect

    Fontes, C. J.; Zhang, H. L.; Jr, J. Abdallah; Clark, R. E. H.; Kilcrease, D. P.; Colgan, J.; Cunningham, R. T.; Hakel, P.; Magee, N. H.; Sherrill, M. E.

    2015-05-28

    The Los Alamos SuitE of Relativistic (LASER) atomic physics codes is a robust, mature platform that has been used to model highly charged ions in a variety of ways. The suite includes capabilities for calculating data related to fundamental atomic structure, as well as the processes of photoexcitation, electron-impact excitation and ionization, photoionization and autoionization within a consistent framework. These data can be of a basic nature, such as cross sections and collision strengths, which are useful in making predictions that can be compared with experiments to test fundamental theories of highly charged ions, such as quantum electrodynamics. The suite can also be used to generate detailed models of energy levels and rate coefficients, and to apply them in the collisional-radiative modeling of plasmas over a wide range of conditions. Such modeling is useful, for example, in the interpretation of spectra generated by a variety of plasmas. In this work, we provide a brief overview of the capabilities within the Los Alamos relativistic suite along with some examples of its application to the modeling of highly charged ions.

  10. Differential collision cross-sections for atomic oxygen

    NASA Technical Reports Server (NTRS)

    Torr, Douglas G.

    1991-01-01

    Differential collision cross-sections of O on N2 and other gases were measured to understand vehicle-environmental contamination effects in orbit. The following subject areas are also covered: groundbased scientific observations of rocket releases during NICARE-1; data compression study for the UVI; science priorities for UV imaging in the mid-1990's; and assessment of optimizations possible in UV imaging systems.

  11. A Physics-Based Vibrotactile Feedback Library for Collision Events.

    PubMed

    Park, Gunhyuk; Choi, Seungmoon

    2016-10-03

    We present PhysVib: a software solution on the mobile platform extending an open-source physics engine in a multi-rate rendering architecture for automatic vibrotactile feedback upon collision events. PhysVib runs concurrently with a physics engine at a low update rate and generates vibrotactile feedback commands at a high update rate based on the simulation results of the physics engine using an exponentially-decaying sinusoidal model. We demonstrate through a user study that this vibration model is more appropriate to our purpose in terms of perceptual quality than more complex models based on sound synthesis. We also evaluated the perceptual performance of PhysVib by comparing eight vibrotactile rendering methods. Experimental results suggested that PhysVib enables more realistic vibrotactile feedback than the other methods as to perceived similarity to the visual events. PhysVib is an effective solution for providing physically plausible vibrotactile responses while reducing application development time to great extent.

  12. Atomic physics at the advanced photon source

    SciTech Connect

    Berry, H.G.; Cowan, P.L.; Gemmell, D.S.

    1995-08-01

    Argonne`s 7-GeV synchrotron light source (APS) is expected to commence operations for research early in FY 1996. The Basic Energy Sciences Synchrotron Research Center (BESSRC) is likewise expected to start its research programs at that time. As members of the BESSRC CAT (Collaborative Access Team), we are preparing, together with atomic physicists from the University of Western Michigan, the University of Tennessee, and University of Notre Dame, to initiate a series of atomic physics experiments that exploit the unique capabilities of the APS, especially its high brilliance for photon energies extending from about 3 keV to more than 50 keV. Most of our early work will be conducted on an undulator beam line and we are thus concentrating on various aspects of that beam line and its associated experimental areas. Our group has undertaken responsibilities in such areas as hutch design, evaluation of undulator performance, user policy, interfacing and instrumentation, etc. Initial experiments will probably utilize existing apparatus. We are, however, planning to move rapidly to more sophisticated measurements involving, for example, ion-beam targets, simultaneous laser excitation, and the spectroscopy of emitted photons.

  13. Astronomy-inspired Atomic and Molecular Physics

    NASA Astrophysics Data System (ADS)

    Rau, A. R. P.

    2002-02-01

    Aimed at senior undergraduate and first-year graduate students in departments of physics and astronomy, this textbook gives a systematic treatment of atomic and molecular structure and spectra, together with the effect of weak and strong external electromagnetic fields. Topics chosen are those of interest in astronomy and indeed many were inspired by specific astronomical contexts. Examples include the negative ion of hydrogen and the effects of strong magnetic fields such as those occurring on certain white dwarfs and neutron stars. Adiabatic and non-adiabatic handling of electron correlations and application to processes such as dielectronic recombination are included. Astronomical examples are provided throughout as well as end-of-the chapter problems and exercises. Over seventy illustrative diagrams complete this unique and comprehensive volume. Link: http://www.wkap.nl/prod/b/1-4020-0467-2

  14. Non-thermal Dupree diffusivity and shielding effects on atomic collisions in Lorentzian turbulent plasmas

    NASA Astrophysics Data System (ADS)

    Lee, Myoung-Jae; Jung, Young-Dae

    2016-05-01

    The influence of non-thermal Dupree turbulence and the plasma shielding on the electron-ion collision is investigated in Lorentzian turbulent plasmas. The second-order eikonal analysis and the effective interaction potential including the Lorentzian far-field term are employed to obtain the eikonal scattering phase shift and the eikonal collision cross section as functions of the diffusion coefficient, impact parameter, collision energy, Debye length and spectral index of the astrophysical Lorentzian plasma. It is shown that the non-thermal effect suppresses the eikonal scattering phase shift. However, it enhances the eikonal collision cross section in astrophysical non-thermal turbulent plasmas. The effect of non-thermal turbulence on the eikonal atomic collision cross section is weakened with increasing collision energy. The variation of the atomic cross section due to the non-thermal Dupree turbulence is also discussed. This research was supported by Nuclear Fusion Research Program through NRF funded by the Ministry of Science, ICT & Future Planning (Grant No. 2015M1A7A1A01002786).

  15. Modeling of Elastic Collisions between High Energy and Slow Neutral Atoms

    DTIC Science & Technology

    2015-07-01

    cylindrical test cell, and the currents on the four different electrodes-Inner Cylinder , Exit Plate, Back Aperture, and Collector Plat~were measured...Inner Cylinder electrode. Nevertheless, the neutral atom current to the Inner Cylinder electrode predicted by the VHS model is comparable to the...Figure 9. Normalized curre nt at the Inner Cylinder e lectrode. the point of collision. T he discrepancy in the Exit Plate neutral atom current is due to

  16. PHYSICS OF POLARIZED SCATTERING AT MULTI-LEVEL ATOMIC SYSTEMS

    SciTech Connect

    Stenflo, J. O.

    2015-03-01

    The symmetric peak observed in linear polarization in the core of the solar sodium D{sub 1} line at 5896 Å has remained enigmatic since its discovery nearly two decades ago. One reason is that the theory of polarized scattering has not been experimentally tested for multi-level atomic systems in the relevant parameter domains, although the theory is continually being used for the interpretation of astrophysical observations. A laboratory experiment that was set up a decade ago to find out whether the D{sub 1} enigma is a problem of solar physics or quantum physics revealed that the D{sub 1} system has a rich polarization structure in situations where standard scattering theory predicts zero polarization, even when optical pumping of the m state populations of the hyperfine-split ground state is accounted for. Here we show that the laboratory results can be modeled in great quantitative detail if the theory is extended to include the coherences in both the initial and final states of the scattering process. Radiative couplings between the allowed dipole transitions generate coherences in the initial state. Corresponding coherences in the final state are then demanded by a phase closure selection rule. The experimental results for the well understood D{sub 2} line are used to constrain the two free parameters of the experiment, collision rate and optical depth, to suppress the need for free parameters when fitting the D{sub 1} results.

  17. Non-Adiabatic Atomic Transitions: Computational Cross Section Calculations of Alkali Metal-Noble Gas Collisions

    DTIC Science & Technology

    2011-09-01

    collisions were computationally simulated. The alkali metals were potassium, rubidium, and cesium and the noble gas partners were helium, neon, and argon...195 20. Spin-Orbit split energies of Potassium, Rubidium, and Cesium ...composed of an alkali metal typically Rubidium[26, 37] or Cesium [5, 18]. The unique character of the alkali atoms, having a single valence electron in

  18. Atomic physics and quantum optics using superconducting circuits.

    PubMed

    You, J Q; Nori, Franco

    2011-06-29

    Superconducting circuits based on Josephson junctions exhibit macroscopic quantum coherence and can behave like artificial atoms. Recent technological advances have made it possible to implement atomic-physics and quantum-optics experiments on a chip using these artificial atoms. This Review presents a brief overview of the progress achieved so far in this rapidly advancing field. We not only discuss phenomena analogous to those in atomic physics and quantum optics with natural atoms, but also highlight those not occurring in natural atoms. In addition, we summarize several prospective directions in this emerging interdisciplinary field.

  19. Atomic physics and non-equilibrium plasmas

    SciTech Connect

    Weisheit, J.C.

    1986-04-25

    Three lectures comprise the report. The lecture, Atomic Structure, is primarily theoretical and covers four topics: (1) Non-relativistic one-electron atom, (2) Relativistic one-electron atom, (3) Non-relativistic many-electron atom, and (4) Relativistic many-electron atom. The lecture, Radiative and Collisional Transitions, considers the problem of transitions between atomic states caused by interactions with radiation or other particles. The lecture, Ionization Balance: Spectral Line Shapes, discusses collisional and radiative transitions when ionization and recombination processes are included. 24 figs., 11 tabs.

  20. Inelastic and reactive collisions with polarized excited Na atoms

    SciTech Connect

    Schmidt, H.; Hertel, I.V.; Lee, Y.T.

    1985-07-01

    Polarization effects in inelastic collisions of laser state-prepared Na(3/sup 2/P, M/sub J/) with Na/sup +/ leading to Na(3/sup 2/D) or Na(3/sup 2/S) are discussed for the energy range E/sub cm/ = 5-47.5eV. Studies with linearly polarized light can be explained with a simple ''locking'' model of the Na(P)-orbital. The investigations employing circularly polarized light are a very sensitive test of the models describing the nonadiabatic angular momentum coupling between electronic and nuclear motion. The dynamical effects of the electronic spin on the angular momentum transfer are discussed. Recent crossed-beam experiments on the Na + O/sub 2/ -> NaO = O reaction in the energy range E/sub cm/ = 0/3-0.8eV show a pronounced dependence on the electric electronic symmetry of Na. 17 refs., 11 figs.

  1. Optical physics: Ultrashort light pulses shake atoms

    NASA Astrophysics Data System (ADS)

    Kim, Kyung Taec

    2016-02-01

    The response of electrons in atoms to ultrashort optical light pulses has been probed by measuring the ultraviolet light emitted by the atoms. This reveals that a finite time delay occurs before the response. See Letter p.66

  2. Physics of Optically Pumped Alkali-Metal Atoms

    DTIC Science & Technology

    2013-04-14

    collision broadening and will be almost completely determined by hyperfine structure, natural radiative broadening and Doppler broadening . 3 When pumped by...supported research, and will be an great advantage for work on greenhouse physics. Of particular interest is how collisions of CO2 molecules with the...nitrogen and oxygen molecules of the air affect the way CO2 absorbs and emits radiation. Incorrect modeling of collisional line broadening is one of

  3. PREFACE: XXIX International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC2015)

    NASA Astrophysics Data System (ADS)

    Díaz, C.; Rabadán, I.; García, G.; Méndez, L.; Martín, F.

    2015-09-01

    The 29th International Conference on Photonic, Electronic and Atomic Collisions (XXIX ICPEAC) was held at the Palacio de Congresos ''El Greco'', Toledo, Spain, on 22-28 July, 2015, and was organized by the Universidad Autónoma de Madrid (UAM) and the Consejo Superior de Investigaciones Científicas (CSIC). ICPEAC is held biannually and is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, and atomic collisions with matter. With a history back to 1958, ICPEAC came to Spain in 2015 for the very first time. UAM and CSIC had been preparing the conference for six years, ever since the ICPEAC International General Committee made the decision to hold the XXIX ICPEAC in Toledo. The conference gathered 670 participants from 52 countries and attracted 854 contributed papers for presentation in poster sessions. Among the latter, 754 are presented in issues 2-12 of this volume of the Journal of Physics Conference Series. In addition, five plenary lectures, including the opening one by the Nobel laureate Prof. Ahmed H. Zewail and the lectures by Prof. Maciej Lewenstein, Prof. Paul Scheier, Prof. Philip H. Bucksbaum, and Prof. Stephen J. Buckman, 62 progress reports and 26 special reports were presented following the decision of the ICPEAC International General Committee. Detailed write-ups of most of the latter are presented in issue 1 of this volume, constituting a comprehensive tangible record of the meeting. On the occasion of the International Year of Light (IYL2015) and with the support of the Fundación Española para la Ciencia y la Tecnología (FECYT), the program was completed with two public lectures delivered by the Nobel laureate Prof. Serge Haroche and the Príncipe de Asturias laureate Prof. Pedro M. Echenique on, respectively, ''Fifty years of laser revolutions in physics'rquot; and ''The sublime usefulness of useless science''. Also a

  4. An independent-atom-model description of ion-molecule collisions including geometric screening corrections

    NASA Astrophysics Data System (ADS)

    Lüdde, Hans Jürgen; Achenbach, Alexander; Kalkbrenner, Thilo; Jankowiak, Hans-Christian; Kirchner, Tom

    2016-04-01

    A new model to account for geometric screening corrections in an independent-atom-model description of ion-molecule collisions is introduced. The ion-molecule cross sections for net capture and net ionization are represented as weighted sums of atomic cross sections with weight factors that are determined from a geometric model of overlapping cross section areas. Results are presented for proton collisions with targets ranging from diatomic to complex polyatomic molecules. Significant improvement compared to simple additivity rule results and in general good agreement with experimental data are found. The flexibility of the approach opens up the possibility to study more detailed observables such as orientation-dependent and charge-state-correlated cross sections for a large class of complex targets ranging from biomolecules to atomic clusters.

  5. Experiments in atomic and applied physics using synchrotron radiation

    SciTech Connect

    Jones, K.W.

    1987-01-01

    A diverse program in atomic and applied physics using x rays produced at the X-26 beam line at the Brookhaven National Synchrotron Light Source is in progress. The atomic physics program studies the properties of multiply-ionized atoms using the x rays for photo-excitation and ionization of neutral atoms and ion beams. The applied physics program builds on the techniques and results of the atomic physics work to develop new analytical techniques for elemental and chemical characterization of materials. The results are then used for a general experimental program in biomedical sciences, geo- and cosmochemistry, and materials sciences. The present status of the program is illustrated by describing selected experiments. Prospects for development of new experimental capabilities are discussed in terms of a heavy ion storage ring for atomic physics experiments and the feasibility of photoelectron microscopy for high spatial resolution analytical work. 21 refs., 11 figs., 2 tabs.

  6. Laser Assisted Free-Free Transition in Electron - Atom Collision

    NASA Technical Reports Server (NTRS)

    Sinha, C.; Bhatia, A. K.

    2011-01-01

    Free-free transition is studied for electron-Hydrogen atom system in ground state at very low incident energies in presence of an external homogeneous, monochromatic and linearly polarized laser field. The incident electron is considered to be dressed by the laser in a non perturbative manner by choosing the Volkov solutions in both the channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the effect of electron exchange, short range as well as of the long range interactions. Laser assisted differential as well as elastic total cross sections are calculated for single photon absorption/emission in the soft photon limit, the laser intensity being much less than the atomic field intensity. A strong suppression is noted in the laser assisted cross sections as compared to the field free situations. Significant difference is noted in the singlet and the triplet cross sections.

  7. Transformation theory and translation factors in inelastic atomic collisions

    NASA Technical Reports Server (NTRS)

    Schmid, G. B.

    1977-01-01

    It is shown through the use of transformation theory that unique semiclassical atomic scattering states which obey the asymptotic conditions of formal scattering theory can be derived by transforming 'nontraveling' atomic states, ie., states whose coordinate variables are referred to a stationary origin, to frames at rest with respect to the incoming or outgoing particles. An overview of the problem of properly defining such scattering states is presented. The operator which carries out the necessary transformation from inertial to noninertial frames is derived and its properties are discussed. The relation of this transformation operator to the 'translation factor' discussed in the literature is presented. The application of this operator to transform the time-dependent Schroedinger equation from an inertial to a noninertial frame is presented and shown to introduce new terms in the resulting equation. The implications of these new terms to scattering problems are discussed.

  8. Project Physics Text 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Basic atomic theories are presented in this fifth unit of the Project Physics text for use by senior high students. Chemical basis of atomic models in the early years of the 18th Century is discussed n connection with Dalton's theory, atomic properties, and periodic tables. The discovery of electrons is described by using cathode rays, Millikan's…

  9. Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology

    NASA Astrophysics Data System (ADS)

    Bartschat, Klaus; Kushner, Mark J.

    2016-06-01

    Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology-based society.

  10. Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology.

    PubMed

    Bartschat, Klaus; Kushner, Mark J

    2016-06-28

    Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology-based society.

  11. Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology

    PubMed Central

    Bartschat, Klaus; Kushner, Mark J.

    2016-01-01

    Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology–based society. PMID:27317740

  12. Electron transfer, ionization, and excitation in atomic collisions. Progress report, June 15, 1992--June 14, 1995

    SciTech Connect

    Winter, T.G.; Alston, S.G.

    1995-08-01

    The research program of Winter and Alston addresses the fundamental processes of electron transfer, ionization, and excitation in ion-atom, ion-ion, and ion-molecule collisions. Attention is focussed on one- and two-electron systems and, more recently, quasi-one-electron systems whose electron-target-core interaction can be accurately modeled by one-electron potentials. The basic computational approaches can then be taken with few, if any, approximations, and the underlying collisional mechanisms can be more clearly revealed. Winter has focussed on intermediate collision energies (e.g., proton energies for p-He{sup +} collisions on the order of 100 kilo-electron volts), in which many electron states are strongly coupled during the collision and a coupled-state approach, such as a coupled-Sturmian-pseudostate approach, is appropriate. Alston has concentrated on higher collision energies (million electron-volt energies), or asymmetric collision systems, for which the coupling of the projectile is weaker with, however, many more target states being coupled together so that high-order perturbation theory is essential. Several calculations by Winter and Alston are described, as set forth in the original proposal.

  13. Reactive Collisions and Interactions of Ultracold Dipolar Atoms

    DTIC Science & Technology

    2014-10-29

    the experimental data [11]. Results of our statistical analyses are presented in Fig. 4. This figure shows the distribution of the nearest - neighbor ...P (s) of nearest - neighbor spacings (NNS) of 168Er Feshbach resonances as a function of dimensionless s = ∆Bρ̄, where the ∆B are NNS and ρ̄ is the mean...in the experimental realization of the strongly correlated quantum gases of atoms with a large magnetic moments, such as Cr [1], Dy [2, 3], and Er [4

  14. GENERAL VIEW, LOOKING NORTH, OF ATOMIC PHYSICS OBSERVATORY WHICH CONTAINS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW, LOOKING NORTH, OF ATOMIC PHYSICS OBSERVATORY WHICH CONTAINS THE WHITE DOME STRUCTURE. THE SHED-LIKE STRUCTURE TO THE LEFT IS THE SEARCH-LIGHT BUILDING. - Carnegie Institution of Washington, Department of Terrestrial Magnetism, Atomic Physics Observatory, 5241 Broad Branch Drive Northwest, Washington, District of Columbia, DC

  15. Two-Centre Convergent Close-Coupling Approach to Ion-Atom Collisions: Current Progress

    NASA Astrophysics Data System (ADS)

    Kadyrov, Alisher; Abdurakhmanov, Ilkhom; Bailey, Jackson; Bray, Igor

    2016-09-01

    There are two versions of the convergent close-coupling (CCC) approach to ion-atom collisions: quantum-mechanical (QM-CCC) and semi-classical (SC-CCC). Recently, both implementations have been extended to include electron-transfer channels. The SC-CCC approach has been applied to study the excitation and the electron-capture processes in proton-hydrogen collisions. The integral alignment parameter A20 for polarization of Lyman- α emission and the cross sections for excitation and electron-capture into the lowest excited states have been calculated for a wide range of the proton impact energies. It has been established that for convergence of the results a very wide range of impact parameters (typically, 0-50 a.u.) is required due to extremely long tails of transition probabilities for transitions into the 2 p states at high energies. The QM-CCC approach allowed to obtain an accurate solution of proton-hydrogen scattering problem including all underlying processes, namely, direct scattering and ionisation, and electron capture into bound and continuum states of the projectile. In this presentation we give a general overview of current progress in applications of the two-centre CCC approach to ion-atom and atom-atom collisions. The work is supported by the Australian Research Council.

  16. A spectroscopic study of hydrogen atom and molecule collisions. Progress report, 1994--1997

    SciTech Connect

    Kielkopf, J.F.

    1997-01-15

    In this project the fundamental processes which occur in low energy collisions of excited states of atomic hydrogen with other atoms and ions are being studied with optical, vacuum ultraviolet and laser spectroscopy. This report covers the period from 1994 to early 1997. We begin here with a brief description of the status of the work at the beginning of this project period, then discuss the goals for this period, our results, and the work in progress now. As the accompanying renewal proposal describes in more detail, the purpose of our work is to understand low energy atom-atom collisions during which light is emitted or absorbed. Because of their fundamental character, such collisions of atomic hydrogen could play a central role if experimental data could be compared with a priori theory. Some interactions involving atomic hydrogen can be calculated very accurately, namely those of H{sub 2}, H{sup +}{sub 2} H{sub 3}, and H{sup +}{sub 3}, and simpler diatomic radicals including OH, CH, and NH. The primary difficulty from the experimental side has been the development of techniques to observe neutral atomic hydrogen interactions at densities high enough for spectral line broadening effects to be observable. This specific research discusses in this report are: laser-produced plasmas in H{sub 2},H{sub 2}+H{sub 2}O, and H{sub 2}+Na; layman alpha wing; line shape theory; ArF laser interaction with H{sub 2}; and work in progress.

  17. Hybrid ion-atom trap for studying ultra-cold collisions

    NASA Astrophysics Data System (ADS)

    Makarov, Oleg P.; Lin, Jian; Smith, W. W.

    2003-05-01

    We built an apparatus for studying ultra-cold collisions between atoms and atomic or molecular ions. Atomic sodium vapor is produced from getters in the ultra-high vacuum chamber. The atoms are trapped in a vapor-cell magneto-optical trap (MOT) by capturing a low-velocity component of a thermal distribution into the region between two anti-Helmholtz coils. A localized cloud of cold Na atoms was successfully generated for MOT types I and II. The cooling transitions were stimulated by the red-detuned Na D2 line emission from a single-frequency stabilized ring-dye laser. The repumping frequency was generated by an electro-optical modulator (EOM) at 1.712 GHz. The loading time constant, ˜ 500 ms, was measured from the fluorescence intensity increase when the magnetic field is suddenly turned on. A linear Paul ion trap, centered on the MOT, is designed to trap Ca^+ ions, produced by electronic bombardment of neutral calcium atoms from a tube oven. A detector is provided for product ions from charge-transfer collisions or photoassociative ionization. We are testing the various components of the completed apparatus. This work is supported by NSF grant # PHY-9988215 and in part by the University of CT Research Foundation.

  18. Direct Scattering, Trapping, and Desorption in Atom-Surface Collisions

    NASA Astrophysics Data System (ADS)

    Fan, Guoqing; Manson, J. R.

    2008-08-01

    Maxwell is credited as the first to invoke the assumption that an impinging gas beam scatters from a surface with a direct contribution exhibiting little change in state and a trapping-desorption fraction that desorbs in equilibrium [J. C. Maxwell, Phil. Trans. R. Soc. LondonPTRSAV0370-2316 170, 231 (1879)10.1098/rstl.1879.0067]. Here a classical mechanical scattering theory is developed to describe direct scattering, trapping, and subsequent desorption of the incident beam. This theory allows a rigorous test of the Maxwell assumption and determines the conditions under which it is valid. The theory also gives quantitative explanations of important new experimental measurements [K. D. Gibson, N. Isa, and S. J. Sibener, J. Chem. Phys. 119, 13 083 (2003)JCPSA60021-960610.1063/1.1628672] for direct and trapping-desorption scattering of Ar atoms by a self-assembled layer of 1-decanethiol on Au(111).

  19. Direct scattering, trapping, and desorption in atom-surface collisions.

    PubMed

    Fan, Guoqing; Manson, J R

    2008-08-08

    Maxwell is credited as the first to invoke the assumption that an impinging gas beam scatters from a surface with a direct contribution exhibiting little change in state and a trapping-desorption fraction that desorbs in equilibrium [J. C. Maxwell, Phil. Trans. R. Soc. London 170, 231 (1879)]. Here a classical mechanical scattering theory is developed to describe direct scattering, trapping, and subsequent desorption of the incident beam. This theory allows a rigorous test of the Maxwell assumption and determines the conditions under which it is valid. The theory also gives quantitative explanations of important new experimental measurements [K. D. Gibson, N. Isa, and S. J. Sibener, J. Chem. Phys. 119, 13 083 (2003)] for direct and trapping-desorption scattering of Ar atoms by a self-assembled layer of 1-decanethiol on Au(111).

  20. Applications of beam-foil spectroscopy to atomic collisions in solids

    NASA Technical Reports Server (NTRS)

    Sellin, I. A.

    1976-01-01

    Some selected papers presented at the Fourth International Conference on Beam-Foil Spectroscopy, whose results are of particular pertinence to ionic collision phenomena in solids, are reviewed. The topics discussed include solid target effects and means of surmounting them in the measurement of excited projectile ion lifetimes for low-energy heavy element ions; the electron emission accompanying the passage of heavy particles through solid targets; the collision broadening of X rays emitted from 100 keV ions moving in solids; residual K-shell excitation in chlorine ions penetrating carbon; comparison between 40 MeV Si on gaseous SiH4 targets at 300 mtorr and 40 MeV Si on Al; and the emergent surface interaction in beam-foil spectroscopy. A distinct overlap of interests between the sciences of beam-foil spectroscopy and atomic collisions in solids is pointed out.

  1. Electron Transfer-Induced Fragmentation in (Bio)Molecules by Atom-Molecule Collisions

    NASA Astrophysics Data System (ADS)

    Limão-Vieira, Paulo; da Silva, Filipe Ferreira; Gómez-Tejedor, Gustavo García

    Ion-pair formation to gas phase molecules induced by electron transfer has been studied by investigating the products of collisions between fast potassium atoms and target molecules using a crossed molecular-beam technique. The negative ions formed in such collisions are TOF mass analysed. As far as (bio)molecules are concerned, TOF mass spectra at different collision energies reveal interesting anionic patterns with reduced fragmentation at lower impact energies. In the unimolecular decomposition of the temporary negative ion (TNI), complex internal rearrangement may involve the cleavage and formation of new bonds. In this chapter we report some of the recent achievements in negative ion formation of some polyatomic molecules with the special attention to biological relevant targets.

  2. Atomic Physics, Science (Experimental): 5318.42.

    ERIC Educational Resources Information Center

    Petit, Ralph E.

    Presented is the study of modern and classical concepts of the atom; the structure of the atom as a mass-energy relationship; practical uses of radioactivity; isotopes; and the strange particles. Performance objectives (16) are included as well as a detailed course outline. Experiments, demonstrations, projects and reports to enhance student…

  3. a Study of Low Energy Electron-Molecule and Ion - Collisions Using Rydberg Atoms

    NASA Astrophysics Data System (ADS)

    Zollars, Byron George

    Low energy collisions between Rydberg atoms and neutral molecules have been investigated over a wide range of principal quantum numbers n, and for several different neutral targets. The results have been used to validate the free-electron, independent particle model of Rydberg atom collisions. Comparison between theory and experiment show that at large values of n, ionization of Rb(nS,nD) Rydberg atoms in the reaction: (UNFORMATTED TABLE FOLLOWS). Rb(nS,nD) + SF(,6) (--->) Rb('+) = SF(,6)('-) (1). (TABLE ENDS). proceeds by electron transfer from the Rydberg atom to the SF(,6) molecule. The rate constants measured for this reaction are much the same as for the attachment of free, low-energy electrons to SF(,6). Thus, Rydberg collision studies can provide information about low-energy free electron interactions. Studies of the rate constants for free ion production in the reaction: (UNFORMATTED TABLE FOLLOWS). K(nD) + SF(,6) (--->) K('+) + SF(,6)('-) (2). (TABLE ENDS). showed these to decrease sharply at smaller n, falling far below the value expected on the basis of Rydberg electron attachment to SF(,6). This behavior is attributed not to breakdown of the free-electron model, but to post -attachment electrostatic interactions between the product ions, which are formed closer to each other at lower n. Model calculations that take this electrostatic interaction into account confirm this prediction. Other Rydberg atom collision processes, such as: (UNFORMATTED TABLE FOLLOWS). K(nD) + O(,2) (--->) K('+) + O(,2)('-) (3). K(nD) + H(,2)O (--->) KH(,2)O('+) + e('-) (4). (TABLE ENDS). have been studied, as they require both the Rydberg ion core and electron to participate in the collision. Since O(,2)('-) ions formed by free electron attachment have short lifetimes against autodetachment, the observation of long-lived O(,2)('-) reaction product suggests that the K('+) core ion plays a role in stabilizing the excited O(,2)('-) ions formed by Rydberg electron attachment. Stable

  4. Ion-biomolecule collisions studied within the independent atom model including geometric screening corrections

    NASA Astrophysics Data System (ADS)

    Lüdde, H. J.; Achenbach, A.; Kalkbrenner, T.; Jankowiak, H. C.; Kirchner, T.

    2016-05-01

    A recently introduced model to account for geometric screening corrections in an independent-atom-model description of ion-molecule collisions is applied to proton collisions from amino acids and DNA and RNA nucleobases. The correction coefficients are obtained from using a pixel counting method (PCM) for the exact calculation of the effective cross sectional area that emerges when the molecular cross section is pictured as a structure of (overlapping) atomic cross sections. This structure varies with the relative orientation of the molecule with respect to the projectile beam direction and, accordingly, orientation-independent total cross sections are obtained from averaging the pixel count over many orientations. We present net capture and net ionization cross sections over wide ranges of impact energy and analyze the strength of the screening effect by comparing the PCM results with Bragg additivity rule cross sections and with experimental data where available. Work supported by NSERC, Canada.

  5. Slow Collisions of Si3+ with Atomic Hydrogen

    NASA Astrophysics Data System (ADS)

    Joseph, D. C.; Gu, J.-P.; Saha, B. C.; Liebermann, H. P.; Funke, P.; Buenker, R. J.

    2010-03-01

    Low energy electron capture from hydrogen atom by multi-charged ions continues to be of interest and applications include both magnetically confined fusion and astrophysical plasmas. The charge exchange process reported here, Si^3+ + H -> Si^2+ + H^+ is an important destruction mechanism of Si^3+ in photo-ionized gas. The soft X-ray emission from comets has been explained by charge transfer of solar wind ions, among them Si^3+, with neutrals in the cometary gas vapor. The state selective cross sections are evaluated using the full quantum [1] and semi-classical molecular orbital close coupling (MOCC) [2] methods. Adiabatic potentials and wave functions for a number of low-lying singlet and triplet states of and symmetry are calculated wing the MRD-CI package [3]. Details will be presented at the conference. [4pt] [1] L. B. Zhao, D. C. Joseph, B. C. Saha, H. P. Liebermann, P. Funke and R. J. Buenker, Phys. Rev A, 79, 034701 (1009).[0pt] [2] M. Kimura and N. F. Lane, At. Mol. Opt. Phys 26, 79 (1990).[0pt] [3] R. J. Buenker, ``Current Aspects of Quantum Chemistry 1981, Vol 21, edited by R. Carbo (Elsevier, Amsterdam) p 17.

  6. Collision-energy-resolved penning ionization electron spectroscopy of HCOOH, CH3COOH, and HCOOCH3 by collision with He*(2(3)S) metastable atoms.

    PubMed

    Borodin, Andriy; Yamazaki, Masakazu; Kishimoto, Naoki; Ohno, Koichi

    2005-06-02

    Penning ionization of formic acid (HCOOH), acetic acid (CH3COOH), and methyl formate (HCOOCH3) upon collision with metastable He*(2(3)S) atoms was studied by collision-energy/electron-energy-resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES). Anisotropy of interaction between the target molecule and He*(2(3)S) was investigated based on the collision energy dependence of partial ionization cross sections (CEDPICS) obtained from 2D-PIES as well as ab initio molecular orbital calculations for the access of a metastable atom to the target molecule. For the interaction potential calculations, a Li atom was used in place of He*(2(3)S) metastable atom because of its well-known similarity in interaction with targets. The results indicate that in the studied collision energy range the attractive potential localizes around the oxygen atoms and that the potential well at the carbonyl oxygen atom is at least twice as much as that at the hydroxyl oxygen. Moreover we can notice that attractive potential is highly anisotropic. Repulsive interactions can be found around carbon atoms and the methyl group.

  7. Atomic physics experiments with stored cooled heavy ion beams

    SciTech Connect

    Datz, S.

    1986-01-01

    The wide ranging interest in the development of heavy ion synchrotrons with electron beam cooling is evident from the number of projects presently under way. Although much of the initial motivation for these rings stemmed from nuclear and particle physics, a considerable amount of atomic physics experimentation is planned. This paper surveys some of the new opportunities in atomic physics which may be made available with storage ring systems. 25 refs., 3 tabs.

  8. Ionization processes in collisions of open-shell atoms. III - The autoionizing states of nitrogen

    NASA Technical Reports Server (NTRS)

    Boumsellek, S.; Esaulov, V. A.

    1990-01-01

    Results of a study of the energy spectra of electrons produced in collisions of N atoms with inert gases at low keV energies are reported. Ionization here is partly due to production of the (1Dnl) autoionizing states of nitrogen and partly due to another mechanism, which is presumably quasi molecular Auger ionization. A discussion of the assignments of the autoionizing states is presented.

  9. Report on the XXIV International Conference on Photonic, Electronic, and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Rivarola, Roberto D.

    2006-08-01

    The XXIV International Conference on Photonic, Electronic, and Atomic Collisions (XXIV ICPEAC) was held in Rosario, Argentina, on 20 26 July 2005, following ICPEAC in Santa Fe, USA, in 2001 and in Stockholm, Sweden, in 2003. This was the first ICPEAC in Latin America and the second one in the Southern Hemisphere, after ICPEAC in Brisbane, Australia, in 1991. The next ICPEAC (25th) will be held in Freiburg (Germany) in 2007.

  10. Report on the XXIII International Conference on Photonic, Electronic and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Schuch, Reinhold

    2004-01-01

    The XXIII International Conference on Photonic, Electronic, and Atomic Collisions (23rd ICPEAC) was held in Stockholm, Sweden, from July 23rd to 29th, 2003, following ICPEAC in Sendai, Japan in 1999 and in Santa Fe, New Mexico, USA, in 2001. This was the first ICPEAC in Sweden and the second one in Scandinavia, after the 18th ICPEAC in Aarhus, Denmark in 1993. The next ICPEAC (24th) will be 2005 in Rosario, Argentina.

  11. Quantum-mechanical theory including angular momenta analysis of atom-atom collisions in a laser field

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1978-01-01

    The problem of two atoms colliding in the presence of an intense radiation field, such as that of a laser, is investigated. The radiation field, which couples states of different electronic symmetry, is described by the number state representation while the electronic degrees of freedom (plus spin-orbit interaction) are discussed in terms of a diabatic representation. The total angular momentum of the field-free system and the angular momentum transferred by absorption (or emission) of a photon are explicitly considered in the derivation of the coupled scattering equations. A model calculation is discussed for the Xe + F collision system.

  12. Absolute cross-section measurements for ionization of He Rydberg atoms in collisions with K

    NASA Astrophysics Data System (ADS)

    Deng, F.; Renwick, S.; Martínez, H.; Morgan, T. J.

    1995-11-01

    Absolute cross sections for ionization of 1.5-10.0 keV/amu Rydberg helium atoms in principal quantum states 12<=n<=15 due to collisions with potassium have been measured. The data are compared with the free-electron cross section at equal velocity. Our results for the collisional ionization cross sections (σi) agree both in shape and absolute magnitude with the data available for the total electron-scattering cross sections (σe) and support recent theoretical models for ionization of Rydberg atoms with neutral perturbers.

  13. A model for energy transfer in collisions of atoms with highly excited molecules.

    PubMed

    Houston, Paul L; Conte, Riccardo; Bowman, Joel M

    2015-05-21

    A model for energy transfer in the collision between an atom and a highly excited target molecule has been developed on the basis of classical mechanics and turning point analysis. The predictions of the model have been tested against the results of trajectory calculations for collisions of five different target molecules with argon or helium under a variety of temperatures, collision energies, and initial rotational levels. The model predicts selected moments of the joint probability distribution, P(Jf,ΔE) with an R(2) ≈ 0.90. The calculation is efficient, in most cases taking less than one CPU-hour. The model provides several insights into the energy transfer process. The joint probability distribution is strongly dependent on rotational energy transfer and conservation laws and less dependent on vibrational energy transfer. There are two mechanisms for rotational excitation, one due to motion normal to the intermolecular potential and one due to motion tangential to it and perpendicular to the line of centers. Energy transfer is found to depend strongly on the intermolecular potential and only weakly on the intramolecular potential. Highly efficient collisions are a natural consequence of the energy transfer and arise due to collisions at "sweet spots" in the space of impact parameter and molecular orientation.

  14. Atomic physics: A milestone in quantum computing

    NASA Astrophysics Data System (ADS)

    Bartlett, Stephen D.

    2016-08-01

    Quantum computers require many quantum bits to perform complex calculations, but devices with more than a few bits are difficult to program. A device based on five atomic quantum bits shows a way forward. See Letter p.63

  15. Atomic collisions in suprafluid helium-nanodroplets: timescales for metal-cluster formation derived from He-density functional theory.

    PubMed

    Hauser, Andreas W; Volk, Alexander; Thaler, Philipp; Ernst, Wolfgang E

    2015-04-28

    Collision times for the coinage metal atoms Cu, Ag and Au in He-droplets are derived from helium density functional theory and molecular dynamics simulations. The strength of the attractive interaction between the metal atoms turns out to be less important than the mass of the propagating metal atoms. Even for small droplets consisting of a few thousand helium atoms, the collision times are shortest for Cu, followed by Ag and Au, despite the higher binding energy of Au2 compared to Cu2.

  16. Atomic collisions in suprafluid helium-nanodroplets: timescales for metal-cluster formation derived from He-density functional theory

    PubMed Central

    Volk, Alexander; Thaler, Philipp

    2015-01-01

    Collision times for the coinage metal atoms Cu, Ag and Au in He-droplets are derived from helium density functional theory and molecular dynamics simulations. The strength of the attractive interaction between the metal atoms turns out to be less important than the mass of the propagating metal atoms. Even for small droplets consisting of a few thousand helium atoms, the collision times are shortest for Cu, followed by Ag and Au, despite the higher binding energy of Au2 compared to Cu2. PMID:25812719

  17. Electronic excitation of ground state atoms by collision with heavy gas particles

    NASA Technical Reports Server (NTRS)

    Hansen, C. Frederick

    1993-01-01

    point where the initial and final potentials cross, or at least come very close. Therefore, this mechanism would be applicable to the case where a gas is initially at very low temperature suddenly subjected to high energy heavy particle bombardment. This situation would model the measurement of excitation cross section by molecular beam techniques, for example. The purpose is to report values of cross sections and rate coefficients for collision excitation of ground state atoms estimated with the Landau-Zener transition theory and to compare results with measurement of excitation cross sections for a beam of Hydrogen atoms impacting Argon atom targets. Some very dubious approximations are used, and the comparison with measurement is found less than ideal, but results are at least consistent within order of magnitude. The same model is then applied to the case of N-N atom collisions, even though the approximations then become even more doubtful. Still the rate coefficients obtained are at least plausible in both magnitude and functional form, and as far as I am aware these are the only estimates available for such rate coefficients.

  18. PREFACE: 8th Asian International Seminar on Atomic and Molecular Physics (AISAMP)

    NASA Astrophysics Data System (ADS)

    Williams, Jim F.; Buckman, Steve; Bieske, Evan J.

    2009-09-01

    These proceedings arose from the 8th Asian International Seminar on Atomic and Molecular Physics (AISAMP) which was held at the University of Western Australia 24-28 November 2008. The history of AISAMP (Takayanagi and Matsuzawa 2002) recognizes its origin from the Japan-China meeting of 1985, and the first use of the name 'The First Asian International Seminar on Atomic and Molecular Physics (AISAMP)' in 1992. The initial attendees, Japan and China, were joined subsequently by scientists from Korea, Taiwan, India, Australia and recently by Malaysia, Thailand, Vietnam, Turkey Iran, UK and USA. The main purpose of the biennial AISAMP series is to create a wide forum for exchanging ideas and information among atomic and molecular scientists and to promote international collaboration. The scope of the AISAMP8 meeting included pure, strategic and applied research involving atomic and molecular structure and processes in all forms of matter and antimatter. For 2008 the AISAMP conference incorporated the Australian Atomic and Molecular Physics and Quantum Chemistry meeting. The topics for AISAMP8 embraced themes from earlier AISAMP meetings and reflected new interests, in atomic and molecular structures, spectroscopy and collisions; atomic and molecular physics with laser or synchrotron radiation; quantum information processing using atoms and molecules; atoms and molecules in surface physics, nanotechnology, biophysics, atmospheric physics and other interdisciplinary studies. The implementation of the AISAMP themes, as well as the international representation of research interests, is indicated both in the contents list of these published manuscripts as well as in the program for the meeting. Altogether, 184 presentations were made at the 8th AISAMP, including Invited Talks and Contributed Poster Presentations, of which 60 appear in the present Proceedings after review by expert referees in accordance with the usual practice of Journal of Physics: Conference Series of

  19. Strong interaction physics from hadronic atoms

    NASA Astrophysics Data System (ADS)

    Batty, C. J.; Friedman, E.; Gal, A.

    1997-08-01

    Hadronic atoms provide a unique laboratory for studying strong interactions and nuclear medium effects at zero kinetic energy. Previous results from analyses of strong-interaction data consisting of level shifts, widths and yields in π-, K -, p¯ and ∑ - atoms are reviewed. Recent results from fits to comprehensive sets of data in terms of density-dependent optical potentials that respect the low-density limit, where the interaction tends to the free hadron nucleon value, are discussed. The importance of using realistic nuclear density distributions is highlighted. The introduction of density dependence in most cases significantly improves the fit to the data and leads to some novel results. For K - atoms, a substantial attraction of order 200 MeV in nuclear matter is suggested, with interesting repercussions for K¯ condensation and the evolution of strangeness in high-density stars. For p¯ atoms it is found that a reasonable p-wave strength can be accommodated in the fitted optical potential, in agreement with the energy dependence observed for some low-energy p¯N reactions. For ∑ - atoms, the fitted potential becomes repulsive inside the nucleus, implying that Σ hyperons generally do not bind in nuclei in agreement with recent measurements. This repulsion significantly affects calculated masses of neutron stars.

  20. "Reaction Microscopes": The "Cloud Chambers" of Atomic and Molecular Physics

    NASA Astrophysics Data System (ADS)

    Ullrich, Joachim

    2004-09-01

    Reaction-Microscopes, developed 10 years ago in order to investigate fast ion-atom collisions [1], allow to determine the complete vector momenta of several electrons and ions emerging as a result of the fragmentation of single atoms, molecules or clusters interacting with electrons, ions, single photons or intense laser pulses. Thus, the complete final-state many-particle wave function in momentum space becomes observable for single and multiple ionisation of atoms as well as for the dissociation of molecules [2]. In the talk the working principle of these machines will be described. Illustrative examples will be given demonstrating the ability of the method to identify the ``mechanisms'' of single and multiple ionisation for electron and ion impact. Its potential for the investigation of single photon as well as of intense laser-pulse induced fragmentation will be highlighted. Future possibilities to investigate ultra-low-energy electron atom or molecule collisions, laser assisted ionisation, using few-cycle phase controlled laser pulses or future free-electron lasers are envisaged. [1] R. Moshammer et al., Phys. Rev. Lett. 73 (1994) 3371 [2] J. Ullrich et al., Rep. Prog. Phys. 66 (2003) 1463

  1. Project Physics Tests 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Test items relating to Project Physics Unit 5 are presented in this booklet. Included are 70 multiple-choice and 23 problem-and-essay questions. Concepts of atomic model are examined on aspects of relativistic corrections, electron emission, photoelectric effects, Compton effect, quantum theories, electrolysis experiments, atomic number and mass,…

  2. ATOMIC PHYSICS, AN AUTOINSTRUCTIONAL PROGRAM, VOLUME 2, SUPPLEMENT.

    ERIC Educational Resources Information Center

    DETERLINE, WILLIAM A.; KLAUS, DAVID J.

    THE AUTOINSTRUCTIONAL MATERIALS IN THIS TEXT WERE PREPARED FOR USE IN AN EXPERIMENTAL STUDY, OFFERING SELF-TUTORING MATERIAL FOR LEARNING ATOMIC PHYSICS. THE TOPICS COVERED ARE (1) ISOTOPES AND MASS NUMBERS, (2) MEASURING ATOMIC MASS, (3) DISCOVERY OF THE NUCLEUS, (4) STRUCTURE OF THE NUCLEUS, (5) DISCOVERY OF THE NEUTRON, (6) NUCLEAR REACTIONS,…

  3. NASA GSFC Science Symposium on Atomic and Molecular Physics

    NASA Technical Reports Server (NTRS)

    Bhatia, Anand K. (Editor)

    2007-01-01

    This document is the proceedings of a conference on atomic and molecular physics in honor of the retirements of Dr. Aaron Temkin and Dr. Richard Drachman. The conference contained discussions on electron, positron, atomic, and positronium physics, as well as a discussion on muon catalyzed fusion. This proceedings document also contains photographs taken at the symposium, as well as speeches and a short biography made in tribute to the retirees.

  4. Effect of electron-nuclei interaction on internuclear motions in slow ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Tolstikhina, Inga Yu.; Tolstikhin, Oleg I.

    2015-10-01

    The electron-nuclei interaction affects the internuclear motion in slow ion-atom collisions, which in turn affects theoretical results for the cross sections of various collision processes. The results are especially sensitive to the details of the internuclear dynamics in the presence of a strong isotope effect on the cross sections, as is the case, e.g., for the charge transfer in low-energy collisions of He2+ with H, D, and T. By considering this system as an example, we show that internuclear trajectories defined by the Born-Oppenheimer (BO) potential in the entrance collision channel, which effectively accounts for the electron-nuclei interaction, are in much better agreement with trajectories obtained in the ab initio electron-nuclear dynamics approach [R. Cabrera-Trujillo et al., Phys. Rev. A 83, 012715 (2011), 10.1103/PhysRevA.83.012715] than the corresponding Coulomb trajectories. We also show that the use of the BO trajectory instead of the Coulomb trajectory in the calculations of the charge-transfer cross sections within the adiabatic approach improves the agreement of the results with ab initio calculations.

  5. Research in Dense Plasma Atomic Physics.

    DTIC Science & Technology

    1984-04-19

    attention on * the solution to the time-independent Schrodinger equation with a self- consistent charge density. For calculations of atomic properties the...interaction potential. Incorporating this potential, the bound and free electron distributions are found from the Schrodinger equation . Thus, given an...spherically symmetric. In Eq. (1), .b is the local density of bound electrons found from solving * the Schrodinger equation where the interaction

  6. Molecular-dynamics simulations of collisions between energetic clusters of atoms and metal substrates

    SciTech Connect

    Hsieh, H.; Averback, R.S. ); Sellers, H. ); Flynn, C.P. )

    1992-02-15

    The collisional dynamics between clusters of Cu, Ni, or Al atoms, with energies of 92 eV to 1.0 keV and sizes of 4 to 92 atoms, and substrates of these same metals were studied using molecular-dynamics computer simulations. A diverse behavior was observed, depending sensitively on the size and energy of the cluster, the elastic and chemical properties of the cluster-substrate combination, and the relative mass of the cluster and substrate atoms. For the 92-atom Cu clusters impacting a Cu substrate, the cluster can form a glob'' on the surface at low energy, while penetrating the substrate and heavily deforming it at high energies. When the cluster energy exceeds {approx}25 eV/atom, the substrate suffers radiation damage. The 92-atom Al clusters do not much deform Ni substrates, but rather tend to spread epitaxially over the surface, despite the 15% lattice mismatch. For 1-keV collisions, several Al atoms dissociate from the cluster, either reflecting into the vacuum or scattering over the surface. 326-eV Ni clusters embed themselves almost completely within Al substrates and form localized amorphous zones. The potentials for these simulations were derived from the embedded-atom method, although modified to treat the higher-energy events. IAb initioP linear-combination-of-atomic-orbitals--molecular-orbitals calculations were employed to test these potentials over a wide range of energies. A simple model for the expected macroscopic behavior of cluster-solid interactions is included as an appendix for a comparison with the atomistic description offered by the simulations.

  7. Model for fast, nonadiabatic collisions between alkali atoms and diatomic molecules

    NASA Astrophysics Data System (ADS)

    Hickman, A. P.

    1980-11-01

    Equations for collisions involving two potential surfaces are presented in the impact parameter approximation. In this approximation, a rectilinear classical trajectory is assumed for the translational motion, leading to a time-dependent Schroedinger's equation for the remaining degrees of freedom. Model potentials are considered for collisions of alkali atoms with diatomic molecules that lead to a particularly simple form of the final equations. Using the Magnus approximation, these equations are solved for parameters chosen to model the process Cs+O2→Cs++O2-, and total cross sections for ion-pair formation are obtained as a function of energy. The results exhibit oscillations that correspond qualitatively to those seen in recent measurements. In addition, the model predicts that the oscillations will become less pronounced as the initial vibrational level of O2 is increased.

  8. Unexplained features of capture and ionization for ion-aligned-Rydberg-atom collisions

    NASA Astrophysics Data System (ADS)

    Perumal, A. N.; Tripathi, D. N.

    2001-10-01

    Observed but unexplained features, namely, oscillations in the capture cross sections and an unexpected increase in the ionization cross sections at lower velocities, are discussed using classical trajectory Monte Carlo simulated results for ion-aligned-Rydberg-atom collisions. The initial alignment (m=0, 1, and 2) dependence of the cross sections shows evidence of ``capture through quasimolecular ion formation,'' identified as the most likely cause for the oscillations. Spatial overlap, in addition to the velocity matching mechanism, is shown to play an important role in the collision process. The unexpected rise in the ionization cross section toward lower reduced velocities is explained qualitatively in terms of the multiple encounter model [Perumal and Tripathi, Nucl. Instrum. Methods B 143, 429 (1998)].

  9. Coordinate space translation technique for simulation of electronic process in the ion-atom collision.

    PubMed

    Wang, Feng; Hong, Xuhai; Wang, Jian; Kim, Kwang S

    2011-04-21

    Recently we developed a theoretical model of ion-atom collisions, which was made on the basis of a time-dependent density functional theory description of the electron dynamics and a classical treatment of the heavy particle motion. Taking advantage of the real-space grid method, we introduce a "coordinate space translation" technique to allow one to focus on a certain space of interest such as the region around the projectile or the target. Benchmark calculations are given for collisions between proton and oxygen over a wide range of impact energy. To extract the probability of charge transfer, the formulation of Lüdde and Dreizler [J. Phys. B 16, 3973 (1983)] has been generalized to ensemble-averaging application in the particular case of O((3)P). Charge transfer total cross sections are calculated, showing fairly good agreements between experimental data and present theoretical results.

  10. Heavy-Rydberg ion-pair formation in Rydberg atom collisions: Probing dissociative electron attachment

    NASA Astrophysics Data System (ADS)

    Kelley, Michael; Buathong, Sitti; Dunning, F. Barry

    2015-05-01

    While electron transfer in Rydberg atom collisions with attaching targets forms a valuable technique with which to create heavy-Rydberg ion pairs to examine their properties, we demonstrate here that measurements of their velocity distributions can also provide insights into the behavior of the excited intermediates formed through initial electron transfer. The experimental results are analyzed with the aid of a Monte Carlo collision code that models the details of electron transfer reactions. Results for a variety of targets are presented that demonstrate the use of this approach to examine the dynamics of dissociative electron attachment, the lifetimes of the intermediates created, and the channels by which they decay. Research supported by the Robert A. Welch Foundation under Grant C-0734.

  11. Recent Applications of the Lattice, Time-Dependent Schr dinger Equation Approach for Ion-Atom Collisions

    SciTech Connect

    Schultz, David Robert; Ovchinnikov, S. Yu.; Sternberg, J. B.; Macek, J. H.

    2011-01-01

    Contemporary computational methods, such as the lattice, time-dependent Schroedinger equation (LTDSE) approach, have opened opportunities to study ion-atom collisions at a new level of detail and to uncover unexpected phenomena. Such interactions within gaseous, plasma, and material environments are fundamental to diverse applications such as low temperature plasma processing of materials, magnetic confinement fusion, and astrophysics. Results are briefly summarized here stemming from recent use of the LTDSE approach, with particular emphasis on elucidation of unexpected vortices in the ejected electron spectrum in ion-atom collisions and for an atom subject to an electric field pulse.

  12. Physical meaning of the multiplicities of emitted nucleons in hadron-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Strugalski, Z.

    1985-01-01

    The analysis of experimental data on hadron-nucleus collisions at energies from about 2 up to about 400 GeV was performed in order to discover a physical meaning of the multiplicity of emitted nucleons. Simple relations between the multiplicities and the thickness of the nuclear matter layer involved in collisions were obtained.

  13. Scattering of NH3 and ND3 with rare gas atoms at low collision energy.

    PubMed

    Loreau, J; van der Avoird, A

    2015-11-14

    We present a theoretical study of elastic and rotationally inelastic collisions of NH3 and ND3 with rare gas atoms (He, Ne, Ar, Kr, Xe) at low energy. Quantum close-coupling calculations have been performed for energies between 0.001 and 300 cm(-1). We focus on collisions in which NH3 is initially in the upper state of the inversion doublet with j = 1, k = 1, which is the most relevant in an experimental context as it can be trapped electrostatically and Stark-decelerated. We discuss the presence of resonances in the elastic and inelastic cross sections, as well as the trends in the inelastic cross sections along the rare gas series and the differences between NH3 and ND3 as a colliding partner. We also demonstrate the importance of explicitly taking into account the umbrella (inversion) motion of NH3 in order to obtain accurate scattering cross sections at low collision energy. Finally, we investigate the possibility of sympathetic cooling of ammonia using cold or ultracold rare gas atoms. We show that some systems exhibit a large ratio of elastic to inelastic cross sections in the cold regime, which is promising for sympathetic cooling experiments. The close-coupling calculations are based on previously reported ab initio potential energy surfaces for NH3-He and NH3-Ar, as well as on new, four-dimensional, potential energy surfaces for the interaction of ammonia with Ne, Kr, and Xe, which were computed using the coupled-cluster method and large basis sets. We compare the properties of the potential energy surfaces corresponding to the interaction of ammonia with the various rare gas atoms.

  14. One and a half centered expansion for ion-atom collisions

    SciTech Connect

    Reading, J.F.; Ford, A.L.; Becker, R.L.

    1980-01-01

    Fast ion-atom collisions in which charge transfer plays a dominant role have been traditionally treated by a two center expansion (TCE): the state wavefunction is approximated by a truncated set of Hilbert states centered on the target and projectile. This method is accurate but expensive in the use of computer time. A new method which allows charge transfer through variational time independent amplitudes, and target excitation and ionization through variational time dependent amplitudes is presented. The method retains the efficiency of a single centered expansion and yet reproduces the conventional TCE results in situations where charge transfer is dominant. Comparison to experiment is made.

  15. Classical-quantum correspondence for ionization in fast ion-atom collisions

    SciTech Connect

    Burgdoerfer, J. |; Reinhold, C.O.

    1994-10-01

    We analyze the interplay between classical and quantum dynamics in ionization of atoms by fast charged particles The convergence to the classical limit is studied as a function of the momentum transferred to the electron during the collision, the impact parameter. the energy and angle of the emitted electron, and the initial state of the target. One goal is to assess the validity of exact classical (CTMC) methods and approximate classical models such as the Thomson model. Applications to data for electron ejection at large angles are presented. The connection between collisional ionization by charged particles and ionization by half-cycle pulses is discussed.

  16. Dissociative excitation of the manganese atom quartet levels by collisions e-MnBr2

    NASA Astrophysics Data System (ADS)

    Smirnov, Yu M.

    2017-04-01

    Dissociative excitation of quartet levels of the manganese atom was studied in collisions of electrons with manganese dibromide molecules. Eighty-two cross-sections for transitions originating at odd levels and eleven cross-sections for transitions originating at even levels have been measured at an incident electron energy of 100 eV. An optical excitation function has been recorded in the electron energy range of 0–100 eV for transitions originating from 3d 64p z 4 F° levels. For the majority of transitions, a comparison of the resulting cross-section values to cross-sections produced by direct excitation is provided.

  17. Charge transfer reactions in multiply charged ion-atom collisions. [in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Steigman, G.

    1975-01-01

    Charge-transfer reactions in collisions between highly charged ions and neutral atoms of hydrogen and/or helium may be rapid at thermal energies. If these reactions are rapid, they will suppress highly charged ions in H I regions and guarantee that the observed absorption features from such ions cannot originate in the interstellar gas. A discussion of such charge-transfer reactions is presented and compared with the available experimental data. The possible implications of these reactions for observations of the interstellar medium, H II regions, and planetary nebulae are outlined.

  18. Cross sections for inelastic collisions of fast charged particles with atoms and molecules

    SciTech Connect

    Inokuti, Mitio

    1985-01-01

    A large volume of data of these cross sections are required for solving problems of radiological physics and dosimetry, as well as for detailed analysis of the earliest stage of radiation actions on matter (including the biological cell and substances constituting it). Current experimental data of the cross sections are far from being complete or even satisfactory for tentative applications. One practical approach to the cross-section determination is to test experimental data with general criteria. For example, the Bethe theory indicates a close connection between photoabsorption and energy absorption by glancing collisions. Development and use of these data constraints, first put forth by Platzman, can now be demonstrated in many examples. More recent studies concern the determination of the analytic expression most suitable for fitting the data on the oscillator-strength distribution or the energy distribution of secondary electrons from ionizing collisions of charged particles. There are three areas to which major efforts should be directed. First, methods of absolute cross-section measurements both for electron and ionic collisions must be thoroughly reviewed so that sources of systematic errors may be identified and corrected. Second, efforts should be devoted to the understanding of the data systematics, viz., the trends of cross sections for a series of molecules. Finally, electron and ionic collisions with molecules in condensed phases will be an important topic of study for years to come; initial reports on efforts toward this direction are encouraging. 46 refs.

  19. Effect of the relative velocity on the collision dipole in a pair of atoms

    SciTech Connect

    Humbert, J.; Galatry, L.

    1983-08-01

    It is shown that the dispersive collision induced dipole in a pair of atoms is dependent on the relative velocity of the partners. Two formulations taking into account this effect are successively presented. In the first one, the origin of the induced dipole lies in the energy coupling between the fluctuating instantaneous dipole of an atom and the reaction field due to the presence of the neighbor; the effect of the relative velocity is introduced through a Fourier expansion of the time dependent internuclear distance. The second method is based on the consideration of the secular equation for approximate instantaneous normal modes of the whole system. In the two cases, the vanishing velocity limit allows to find again a known result. For a nonzero relative velocity, a limited expansion is obtained and the two lowest order terms are given. Order of magnitude of the effects are estimated in a model of harmonic oscillators.

  20. International Conference on Atomic Physics: Abstracts of Contributed Papers (12th) Held in Ann Arbor, Michigan on 29 July-3 August 1990

    DTIC Science & Technology

    1990-09-26

    the local physics of the 2 1Ne nucleus . Systematic variations of the quadrupole component at multiples of the earth’s solar frequency do arise, mostly...equation is justified when the thermalization by wal Collisions drives the atomic velocity distribution to equilibrium on a time scale that is slow...inelastic cavity collisions in which particles can either lose energy or annihilate for a distribution of initial o-Ps energies. We expect such a

  1. Directly probing anisotropy in atom-molecule collisions through quantum scattering resonances

    NASA Astrophysics Data System (ADS)

    Klein, Ayelet; Shagam, Yuval; Skomorowski, Wojciech; Żuchowski, Piotr S.; Pawlak, Mariusz; Janssen, Liesbeth M. C.; Moiseyev, Nimrod; van de Meerakker, Sebastiaan Y. T.; van der Avoird, Ad; Koch, Christiane P.; Narevicius, Edvardas

    2017-01-01

    Anisotropy is a fundamental property of particle interactions. It occupies a central role in cold and ultracold molecular processes, where orientation-dependent long-range forces have been studied in ultracold polar molecule collisions. In the cold collisions regime, quantization of the intermolecular degrees of freedom leads to quantum scattering resonances. Although these states have been shown to be sensitive to details of the interaction potential, the effect of anisotropy on quantum resonances has so far eluded experimental observation. Here, we directly measure the anisotropy in atom-molecule interactions via quantum resonances by changing the quantum state of the internal molecular rotor. We observe that a quantum scattering resonance at a collision energy of kB × 270 mK appears in the Penning ionization of molecular hydrogen with metastable helium only if the molecule is rotationally excited. We use state-of-the-art ab initio theory to show that control over the rotational state effectively switches the anisotropy on or off, disentangling the isotropic and anisotropic parts of the interaction.

  2. Atoms in Flight: The Remarkable Connections between Atomic and Hadronic Physics

    SciTech Connect

    Brodsky, Stanley J.; /SLAC

    2012-02-16

    Atomic physics and hadron physics are both based on Yang Mills gauge theory; in fact, quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics provide important insight into the theory of hadrons in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of light-front relativistic equations of motion which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The renormalization scale for the running coupling, which is unambiguously set in QED, leads to a method for setting the renormalization scale in QCD. The production of atoms in flight provides a method for computing the formation of hadrons at the amplitude level. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, and light-front quantization have equal utility for atomic physics, especially in the relativistic domain. I also present a new perspective for understanding the contributions to the cosmological constant from QED and QCD.

  3. Wave-packet continuum-discretization approach to ion-atom collisions: Nonrearrangement scattering

    NASA Astrophysics Data System (ADS)

    Abdurakhmanov, I. B.; Kadyrov, A. S.; Bray, I.

    2016-08-01

    A general single-center close-coupling approach based on a continuum-discretization procedure is developed to calculate excitation and ionization processes in ion-atom collisions. The continuous spectrum of the target is discretized using stationary wave packets constructed from the Coulomb wave functions, the eigenstates of the target Hamiltonian. Such continuum discretization allows one to generate pseudostates with arbitrary energies and distribution. These features are ideal for detailed differential ionization studies. The approach starts from the semiclassical three-body Schrödinger equation for the scattering wave function and leads to a set of coupled differential equations for the transition probability amplitudes. To demonstrate its utility the method is applied to calculate collisions of antiprotons with atomic hydrogen. A comprehensive set of benchmark results from integrated to fully differential cross sections for antiproton-impact ionization of hydrogen in the energy range from 1 keV to 1 MeV is provided. Contrary to previous predictions, we find that at low incident energies the singly differential cross section has a maximum away from the zero emission energy. This feature could not be seen without a fine discretization of the low-energy part of the continuum.

  4. Charge exchange collisions of slow C6 + with atomic and molecular H

    NASA Astrophysics Data System (ADS)

    Saha, Bidhan C.; Guevara, Nicolais L.; Sabin, John R.; Deumens, Erik; Öhrn, Yngve

    2016-04-01

    Charge exchange in collisions of C6+ ions with H and H2 is investigated theoretically at projectile energies 0.1 < E < 10 keV/amu, using electron nuclear dynamics (END) - a semi-classical approximation which not only includes electron translation factors for avoiding spurious couplings but also employs full dynamical trajectories to treat nuclear motions. Both the total and partial cross sections are reported for the collision of C6+ ions with atomic and molecular hydrogen. A comparison with other theoretical and experimental results shows, in general good agreement except at very low energy, considered here. For H2, the one- and two-electron charge exchange cross sections are calculated and compared with other theoretical and experimental results. Small but non-negligible isotope effects are found at the lowest energy studied in the charge transfer of C6+ with H. In low energy region, it is observed that H2 has larger isotope effects than H atom due to the polarizability effect which is larger than the mass effect.

  5. The Common Elements of Atomic and Hadronic Physics

    SciTech Connect

    Brodsky, Stanley J.

    2015-02-26

    Atomic physics and hadronic physics are both governed by the Yang Mills gauge theory Lagrangian; in fact, Abelian quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics can provide important insight into hadronic eigenstates in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of frame-independent light-front relativistic equations of motion consistent with light-front holography which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The production of antihydrogen in flight can provide important insight into the dynamics of hadron production in QCD at the amplitude level. The renormalization scale for the running coupling is unambiguously set in QED; an analogous procedure sets the renormalization scales in QCD, leading to scheme-independent scale-fixed predictions. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, the quark-interchange process and light-front quantization have important applicants for atomic physics and photon science, especially in the relativistic domain.

  6. Spectroscopy and atomic physics of highly ionized Cr, Fe, and Ni for tokamak plasmas

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Doschek, G. A.; Cheng, C.-C.; Bhatia, A. K.

    1980-01-01

    The paper considers the spectroscopy and atomic physics for some highly ionized Cr, Fe, and Ni ions produced in tokamak plasmas. Forbidden and intersystem wavelengths for Cr and Ni ions are extrapolated and interpolated using the known wavelengths for Fe lines identified in solar-flare plasmas. Tables of transition probabilities for the B I, C I, N I, O I, and F I isoelectronic sequences are presented, and collision strengths and transition probabilities for Cr, Fe, and Ni ions of the Be I sequence are given. Similarities of tokamak and solar spectra are discussed, and it is shown how the atomic data presented may be used to determine ion abundances and electron densities in low-density plasmas.

  7. Collisions of alkali-metal atoms Cs and Rb in the ground state. Spin exchange cross sections

    NASA Astrophysics Data System (ADS)

    Kartoshkin, V. A.

    2016-09-01

    Collisions of alkali-metal atoms 133Cs and 85Rb in the ground state are considered in the energy interval of 10-4-10-2 au. Complex cross sections of the spin exchange, which allow one to calculate the processes of polarization transfer and the relaxation times, as well as the magnetic resonance frequency shifts caused by spin exchange Cs-Rb collisions, are obtained.

  8. Forward electron production in heavy ion-atom and ion-solid collisions

    SciTech Connect

    Sellin, I.A.

    1984-01-01

    A sharp cusp in the velocity spectrum of electrons, ejected in ion-atom and ion-solid collisions, is observed when the ejected electron velocity vector v/sub e/ matches that of the emergent ion vector v/sub p/ in both speed and direction. In ion-atom collisions, the electrons originate from capture to low-lying, projectile-centered continuum states (ECC) for fast bare or nearly bare projectiles, and from loss to those low-lying continuum states (ELC) when loosely bound projectile electrons are available. Most investigators now agree that ECC cusps are strongly skewed toward lower velocities, and exhibit full widths half maxima roughly proportional to v/sub p/ (neglecting target-shell effects, which are sometimes strong). A close examination of recent ELC data shows that ELC cusps are instead nearly symmetric, with widths nearly independent on v/sub p/ in the velocity range 6 to 18 a.u., a result only recently predicted by theory. Convoy electron cusps produced in heavy ion-solid collisions at MeV/u energies exhibit approximately velocity-independent widths very similar to ELC cusp widths. While the shape of the convoy peaks is approximately independent of projectile Z, velocity, and of target material, it is found that the yields in polycrystalline targets exhibit a strong dependence on projectile Z and velocity. While attempts have been made to link convoy electron production to binary ECC or ELC processes, sometimes at the last layer, or alternatively to a solid-state wake-riding model, our measured dependences of cusp shape and yield on projectile charge state and energy are inconsistent with the predictions of available theories. 10 references, 8 figures, 1 table.

  9. Accurate Cross-section Calculations for Low-Energy Electron-Atom Collisions

    SciTech Connect

    Zatsarinny, Oleg; Bartschat, Klaus

    2011-05-11

    We describe a recently developed fully relativistic B-spline R-matrix method for atomic structure as well as calculations for electron and photon collision with atoms and ions. The method is based on the solution of the many-electron Fock-Dirac equation and allows to employ non-orthogonal sets of atomic orbitals. A B-spline basis is used to generate both the target description and the R-matrix basis functions in the inner region. Employing B-splines of different orders for the large and small components prevents the appearance of spurious states in the spectrum of the Dirac equation. Using term-dependent and thus nonorthogonal sets of one-electron functions enables us to generate accurate and flexible representations of the target states and the scattering function. Our method is based upon the Dirac-Coulomb Hamiltonian and thus may be employed for any complex atom or ion, without the use of phenomenological core potentials. Example results from recent applications of the method for accurate calculations of low-energy electron scattering from noble gases are presented. In most cases we obtained a substantial improvement over results obtained in previous Breit-Pauli R-matrix calculations.

  10. Zeeman relaxation of cold atomic iron and nickel in collisions with {sup 3}He

    SciTech Connect

    Johnson, Cort; Newman, Bonna; Kleppner, Daniel; Greytak, Thomas J.; Brahms, Nathan; Doyle, John M.

    2010-06-15

    We have measured the ratio {gamma} of the diffusion cross section to the angular momentum reorientation cross section in the colliding Fe-{sup 3}He and Ni-{sup 3}He systems. Nickel (Ni) and iron (Fe) atoms are introduced via laser ablation into a cryogenically cooled experimental cell containing cold (<1 K) {sup 3}He buffer gas. Elastic collisions rapidly cool the translational temperature of the ablated atoms to the {sup 3}He temperature. {gamma} is extracted by measuring the decays of the atomic Zeeman sublevels. For our experimental conditions, thermal energy is comparable to the Zeeman splitting. As a result, thermal excitations between Zeeman sublevels significantly impact the observed decay. To determine {gamma} accurately, we introduce a model of Zeeman-state dynamics that includes thermal excitations. We find {gamma}{sub Ni-}{sup 3}{sub He}=5x10{sup 3} and {gamma}{sub Fe-}{sup 3}{sub He{<=}}3x10{sup 3} at 0.75 K in a 0.8-T magnetic field. These measurements are interpreted in the context of submerged shell suppression of spin relaxation, as studied previously in transition metals and rare-earth-metal atoms [C. I. Hancox, S. C. Doret, M. T. Hummon, R. V. Krems, and J. M. Doyle, Phys. Rev. Lett. 94, 013201 (2005); C. I. Hancox, S. C. Doret, M. T. Hummon, L. Luo, and J. M. Doyle, Nature (London) 431, 281 (2004); A. Buchachenko, G. Chaasiski, and M. Szczniak, Eur. Phys. J. D 45, 147 (2007)].

  11. A molecular dynamics simulation of hydrogen atoms collisions on an H-preadsorbed silica surface

    NASA Astrophysics Data System (ADS)

    Rutigliano, M.; Gamallo, P.; Sayós, R.; Orlandini, S.; Cacciatore, M.

    2014-08-01

    The interaction of hydrogen atoms and molecules with a silica surface is relevant for many research and technological areas. Here, the dynamics of hydrogen atoms colliding with an H-preadsorbed β-cristobalite (0 0 1) surface has been studied using a semiclassical collisional method in conjunction with a recently developed analytical potential energy surface based on density functional theory (DFT) calculations. The atomic recombination probability via an Eley-Rideal (E-R) mechanism, as well as the probabilities for other competitive surface processes, have been determined in a broad range of collision energies (0.04-3.0 eV) for off-normal (θv = 45°) and normal (θv = 0°) incidence and for two different surface temperatures (TS = 300 and 1000 K). H2,gas molecules form in roto-vibrational excited levels while the energy transferred to the solid surface is below 10% for all simulated conditions. Finally, the global atomic recombination coefficient (γE-R) and vibrational state resolved recombination coefficients (γ(v)) were calculated and compared with the available experimental values. The calculated collisional data are of interest in chemical kinetics studies and fluid dynamics simulations of silica surface processes in H-based low-temperature, low-pressure plasmas.

  12. Computational test of the infinite order sudden approximation for excitation of linear rigid rotors by collisions with atoms

    NASA Technical Reports Server (NTRS)

    Green, S.

    1978-01-01

    The infinite order sudden approximation for excitation of linear rigid rotors by collisions with atom is tested by comparing integral state-to-state cross sections with accurate close coupling and coupled states results. The systems studied are HCl-Ar, HCl-He, CO-He, HCN-He, CS-H2 and OCS-H2. With the exception of diatomic hydrides (e.g., HCl) which have atypically large rotational constants the method is found to be very accurate to remarkably low collision energies. This approximation should generally be extremely useful for thermal energy collisions.

  13. Quantifying the physical demands of collision sports: does microsensor technology measure what it claims to measure?

    PubMed

    Gabbett, Tim J

    2013-08-01

    The physical demands of rugby league, rugby union, and American football are significantly increased through the large number of collisions players are required to perform during match play. Because of the labor-intensive nature of coding collisions from video recordings, manufacturers of wearable microsensor (e.g., global positioning system [GPS]) units have refined the technology to automatically detect collisions, with several sport scientists attempting to use these microsensors to quantify the physical demands of collision sports. However, a question remains over the validity of these microtechnology units to quantify the contact demands of collision sports. Indeed, recent evidence has shown significant differences in the number of "impacts" recorded by microtechnology units (GPSports) and the actual number of collisions coded from video. However, a separate study investigated the validity of a different microtechnology unit (minimaxX; Catapult Sports) that included GPS and triaxial accelerometers, and also a gyroscope and magnetometer, to quantify collisions. Collisions detected by the minimaxX unit were compared with video-based coding of the actual events. No significant differences were detected in the number of mild, moderate, and heavy collisions detected via the minimaxX units and those coded from video recordings of the actual event. Furthermore, a strong correlation (r = 0.96, p < 0.01) was observed between collisions recorded via the minimaxX units and those coded from video recordings of the event. These findings demonstrate that only one commercially available and wearable microtechnology unit (minimaxX) can be considered capable of offering a valid method of quantifying the contact loads that typically occur in collision sports. Until such validation research is completed, sport scientists should be circumspect of the ability of other units to perform similar functions.

  14. Adiabatic Variational Theory for Cold Atom-Molecule Collisions: Application to a Metastable Helium Atom Colliding with ortho- and para-Hydrogen Molecules.

    PubMed

    Pawlak, Mariusz; Shagam, Yuval; Klein, Ayelet; Narevicius, Edvardas; Moiseyev, Nimrod

    2017-03-16

    We recently developed an adiabatic theory for cold molecular collision experiments. In our previous application of this theory ( Pawlak, M.; et al. J. Chem. Phys. 2015 , 143 , 074114 ), we assumed that during the experiment the collision of an atom with a diatom takes place when the diatom is in the ground rotational state and is located in a plane. In this paper, we present how the variational approach of the adiabatic theory for low-temperature collision experiments can be used for the study a 5D collision between the atom and the diatomic molecule with no limitations on its rotational quantum states and no plane restrictions. Moreover, we show here the dramatic differences in the measured reaction rates of He(2(3)S1) + ortho/para-H2 → He(1s(2)) + ortho/para-H2(+) + e(-) resulting from the anisotropic long-range interactions in the reaction. In collisions of metastable helium with molecular hydrogen in the ground rotational state, the isotropic potential term dominates the dynamics. When the collision is with molecular hydrogen in the first excited rotational state, the nonisotropic interactions play an important role in the dynamics. The agreement of our results with the latest experimental findings ( Klein , A. ; et al. Nat. Phys. 2017 , 13 , 35 - 38 ) is very good.

  15. Near-threshold photoionization of hydrogenlike uranium studied in ion-atom collisions via the time-reversed process.

    PubMed

    Stöhlker, T; Ma, X; Ludziejewski, T; Beyer, H F; Bosch, F; Brinzanescu, O; Dunford, R W; Eichler, J; Hagmann, S; Ichihara, A; Kozhuharov, C; Krämer, A; Liesen, D; Mokler, P H; Stachura, Z; Swiat, P; Warczak, A

    2001-02-05

    Radiative electron capture, the time-reversed photoionization process occurring in ion-atom collisions, provides presently the only access to photoionization studies for very highly charged ions. By applying the deceleration mode of the ESR storage ring, we studied this process in low-energy collisions of bare uranium ions with low- Z target atoms. This technique allows us to extend the current information about photoionization to much lower energies than those accessible for neutral heavy elements in the direct reaction channel. The results prove that for high- Z systems, higher-order multipole contributions and magnetic corrections persist even at energies close to the threshold.

  16. Excitation and charge transfer in low-energy hydrogen-atom collisions with neutral atoms: Theory, comparisons, and application to Ca

    NASA Astrophysics Data System (ADS)

    Barklem, Paul S.

    2016-04-01

    A theoretical method is presented for the estimation of cross sections and rates for excitation and charge-transfer processes in low-energy hydrogen-atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent interactions in the neutral atom-hydrogen-atom system. The calculation of potentials and nonadiabatic radial couplings using the method is demonstrated. The potentials are used together with the multichannel Landau-Zener model to calculate cross sections and rate coefficients. The main feature of the method is that it employs asymptotically exact atomic wave functions, which can be determined from known atomic parameters. The method is applied to Li+H , Na+H , and Mg+H collisions, and the results compare well with existing detailed full-quantum calculations. The method is applied to the astrophysically important problem of Ca+H collisions, and rate coefficients are calculated for temperatures in the range 1000-20 000 K.

  17. Majorana: From Atomic and Molecular, to Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Pucci, R.; Angilella, G. G. N.

    2006-10-01

    In the centennial of Ettore Majorana's birth (1906-1938?), we re-examine some aspects of his fundamental scientific production in atomic and molecular physics, including a not well known short communication. There, Majorana critically discusses Fermi's solution of the celebrated Thomas-Fermi equation for electron screening in atoms and positive ions. We argue that some of Majorana's seminal contributions in molecular physics already prelude to the idea of exchange interactions (or Heisenberg-Majorana forces) in his later workson theoretical nuclear physics. In all his papers, he tended to emphasize the symmetries at the basis of a physical problem, as well as the limitations, rather than the advantages, of the approximations of the method employed.

  18. Bringing atomic and nuclear physics laboratory data into the classroom

    SciTech Connect

    Norman, Eric B.; Larimer, Ruth-Mary; Rech, Gregory; Lee, Jeffrey; Vue, Chue; Leubane, Tholoana; Zamvil, Kenneth; Guthrie, Laura

    2003-05-27

    To illustrate a number of basic concepts in atomic and nuclear physics, we have developed three websites where students can analyze data from modern laboratories. By working through the on-line procedures, students will become acquainted with characteristic x-ray spectra, the concept of half-life, x-ray fluorescence, and neutron activation analysis.

  19. ATOMIC PHYSICS, AN AUTOINSTRUCTIONAL PROGRAM, VOLUME 3, SUPPLEMENT.

    ERIC Educational Resources Information Center

    DETERLINE, WILLIAM A.; KLAUS, DAVID J.

    THE AUTOINSTRUCTIONAL MATERIALS IN THIS TEXT WERE PREPARED FOR USE IN AN EXPERIMENTAL STUDY, OFFERING SELF-TUTORING MATERIAL FOR LEARNING ATOMIC PHYSICS. THE TOPICS COVERED ARE (1) NUCLEAR BINDING ENERGY, (2) DISCOVERY OF RADIOACTIVITY, (3) RADIOACTIVE RADIATIONS, (4) ALPHA AND BETA DECAY, (5) BETA DECAY REACTIONS, (6) RADIOACTIVE DATING AND…

  20. Project Physics Reader 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    As a supplement to Project Physics Unit 5, a collection of articles is presented in this reader for student browsing. Nine excerpts are given under the following headings: failure and success, Einstein, Mr. Tompkins and simultaneity, parable of the surveyors, outside and inside the elevator, the teacher and the Bohr theory of atom, Dirac and Born,…

  1. ATOMIC PHYSICS, AN AUTOINSTRUCTIONAL PROGRAM, VOLUME 4, SUPPLEMENT.

    ERIC Educational Resources Information Center

    DETERLINE, WILLIAM A.; KLAUS, DAVID J.

    THE AUTOINSTRUCTIONAL MATERIALS IN THIS TEXT WERE PREPARED FOR USE IN AN EXPERIMENTAL STUDY, OFFERING SELF-TUTORING MATERIAL FOR LEARNING ATOMIC PHYSICS. THE TOPICS COVERED ARE (1) RADIATION USES AND NUCLEAR FISSION, (2) NUCLEAR REACTORS, (3) ENERGY FROM NUCLEAR REACTORS, (4) NUCLEAR EXPLOSIONS AND FUSION, (5) A COMPREHENSIVE REVIEW, AND (6) A…

  2. Treasure of the Past X: A Spectroscopic Determination of Scattering Lengths for Sodium Atom Collisions

    PubMed Central

    Tiesinga, Eite; Williams, Carl J.; Julienne, Paul S.; Jones, Kevin M.; Lett, Paul D.; Phillips, William D.

    2002-01-01

    We report a preliminary value for the zero magnetic field Na 2S(f = 1, m = − 1) + Na 2S(f = 1, m = − 1) scattering length, a1,−1. This parameter describes the low-energy elastic two-body processes in a dilute gas of composite bosons and determines, to a large extent, the macroscopic wavefunction of a Bose condensate in a trap. Our scattering length is obtained from photoassociative spectroscopy with samples of uncondensed atoms. The temperature of the atoms is sufficiently low that contributions from the three lowest partial waves dominate the spectrum. The observed lineshapes for the purely long-range 0g− molecular state enable us to establish key features of the ground state scattering wavefunction. The fortuitous occurrence of a p-wave node near the deepest point (Re = 72 a0) of the 0g− potential curve is instrumental in determining a1,−1 = (52 ± 5) a0 and a2.2 = (85 ± 3) a0, where the latter is for a collision of two Na 2S(f = 2, m = 2) atoms. PMID:27446722

  3. Spin-Orbit Interactions and Quantum Spin Dynamics in Cold Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Tscherbul, Timur V.; Brumer, Paul; Buchachenko, Alexei A.

    2016-09-01

    We present accurate ab initio and quantum scattering calculations on a prototypical hybrid ion-atom system Yb+ -Rb, recently suggested as a promising candidate for the experimental study of open quantum systems, quantum information processing, and quantum simulation. We identify the second-order spin-orbit (SO) interaction as the dominant source of hyperfine relaxation in cold Yb+ -Rb collisions. Our results are in good agreement with recent experimental observations [L. Ratschbacher et al., Phys. Rev. Lett. 110, 160402 (2013)] of hyperfine relaxation rates of trapped Yb+ immersed in an ultracold Rb gas. The calculated rates are 4 times smaller than is predicted by the Langevin capture theory and display a weak T-0.3 temperature dependence, indicating significant deviations from statistical behavior. Our analysis underscores the deleterious nature of the SO interaction and implies that light ion-atom combinations such as Yb+ -Li should be used to minimize hyperfine relaxation and decoherence of trapped ions in ultracold atomic gases.

  4. Quasiclassical trajectory study of the vibrational quenching of hydroxyl radicals through collision with O atoms.

    PubMed

    Viswanathan, Raji; Dolgos, Michelle; Hinde, Robert J

    2007-02-08

    The collisional removal of vibrationally excited OH radicals by O atoms is studied by the quasiclassical trajectory method. To evaluate the effect of different topological features on the scattering processes two different global potential energy surfaces, DMBE IV and TU, are used. Results for reactive, exchange, and inelastic scattering probabilities are reported for central collisions (with zero total angular momentum) with a fixed relative translational energy for vibrational levels of OH ranging from nu=1 to v=8. Vibrational state distributions of product molecules are also compared on the two potential energy surfaces. Both surfaces predict higher probabilities for reaction than for exchange or inelastic scattering. The vibrational state distributions of the product diatomic molecules are different on the two surfaces. In particular, the two surfaces give substantially different probabilities for multiquantum OH vibrational relaxation transitions OH(v)+O-->OH(v')+O.

  5. Dynamics of the sputtering of water from ice films by collisions with energetic xenon atoms.

    PubMed

    Killelea, Daniel R; Gibson, K D; Yuan, Hanqiu; Becker, James S; Sibener, S J

    2012-04-14

    The flow of energy from the impact site of a heavy, translationally energetic xenon atom on an ice surface leads to several non-equilibrium events. The central focus of this paper is on the collision-induced desorption (sputtering) of water molecules into the gas-phase from the ice surface. Sputtering is strongly activated with respect to xenon translational energy, and a threshold for desorption was observed. To best understand these results, we discuss our findings in the context of other sputtering studies of molecular solids. The sputtering yield is quite small; differential measurements of the energy of xenon scattered from ice surfaces show that the ice efficiently accommodates the collisional energy. These results are important as they quantitatively elucidate the dynamics of such sputtering events, with implications for energetic non-equilibrium processes at interfaces.

  6. Atomic physics of strongly correlated systems. Progress report, 1 August 1980-31 July 1981

    SciTech Connect

    Lin, C.D.

    1981-03-01

    Studies of electron correlations of doubly-excited electrons in hyperspherical coordinates, and differential and total cross sections for charge transfer and ionization in fast ion-atom collisions are reported. (GHT)

  7. Zeeman relaxation of cold atomic iron and nickel in collisions with He3

    NASA Astrophysics Data System (ADS)

    Johnson, Cort; Newman, Bonna; Brahms, Nathan; Doyle, John M.; Kleppner, Daniel; Greytak, Thomas J.

    2010-06-01

    We have measured the ratio γ of the diffusion cross section to the angular momentum reorientation cross section in the colliding Fe-He3 and Ni-He3 systems. Nickel (Ni) and iron (Fe) atoms are introduced via laser ablation into a cryogenically cooled experimental cell containing cold (<1 K) He3 buffer gas. Elastic collisions rapidly cool the translational temperature of the ablated atoms to the He3 temperature. γ is extracted by measuring the decays of the atomic Zeeman sublevels. For our experimental conditions, thermal energy is comparable to the Zeeman splitting. As a result, thermal excitations between Zeeman sublevels significantly impact the observed decay. To determine γ accurately, we introduce a model of Zeeman-state dynamics that includes thermal excitations. We find γNi-3He=5×103 and γFe-3He⩽3×103 at 0.75 K in a 0.8-T magnetic field. These measurements are interpreted in the context of submerged shell suppression of spin relaxation, as studied previously in transition metals and rare-earth-metal atoms [C. I. Hancox, S. C. Doret, M. T. Hummon, R. V. Krems, and J. M. Doyle, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.94.013201 94, 013201 (2005); C. I. Hancox, S. C. Doret, M. T. Hummon, L. Luo, and J. M. Doyle, Nature (London)NATUAS0028-083610.1038/nature02938 431, 281 (2004); A. Buchachenko, G. Chaasiski, and M. Szczniak, Eur. Phys. J. DEPJDF61434-606010.1140/epjd/e2006-00263-3 45, 147 (2007)].

  8. Strong field atomic physics in the mid-infrared

    SciTech Connect

    Sheehy, B; Martin, J D D; Clatterbuck, T O; Kim, D W; DiMauro, L F; Agostini, P; Schafer, K J; Gaarde, M B; Kulander, K C

    2000-03-15

    We examine strong field atomic physics in a wavelength region (3-4 microns) where very little work has previously been done. The soft photon energy allows the exploration of one-electron atoms with low binding energies (alkali metals). We find that photoionization spectra differ from rare gas studies at shorter wavelengths due to more complex ion core potentials. Harmonic generation is studied, and we find that harmonic bandwidths are consistent with theory and the possibility of compression to pulse widths much shorter than that of the driving pulse. Harmonic yields in the visible and W are sufficient for a complete study of their amplitude and phase characteristics.

  9. Classical and quantum analysis of quasiresonance in grazing atom-surface collisions

    SciTech Connect

    Ruiz, Antonia; Palao, Jose P.; Heller, Eric J.

    2009-05-15

    Quasiresonance is a general effect that may arise from the coupling between approximately resonant degrees of freedom in a system perturbed by some transient interaction. In a process induced by a slowly switching on and off of the coupling interaction, quasiresonance is characterized by the existence of significant ranges of initial states in the perturbed system over which some very specific and efficient transfer of energy between the approximately resonant degrees of freedom occurs. This work presents a classical and quantum analysis of quasiresonant processes in grazing incident angle atom-surface collisions. The momentum transfer between the normal components to an index direction is investigated. For fast atoms with grazing angle of incidence there is an interval of azimuthal angles around the index directions, the quasiresonance region, in which the energy transfer can be very efficient. This effect is reflected in quantum diffraction patterns with large nonspecular peaks, associated with the parallel to the surface and normal to the index direction momentum component. We demonstrate the essentially classical underlying mechanism for the persistence of a pattern of diffraction peak intensities for incidence close to an index direction. The analysis also shows that the size of the quasiresonance region is approximately equal to the spectral width of the diffraction pattern.

  10. Cold collisions of polyatomic molecular radicals with S-state atoms in a magnetic field: An ab initio study of He + CH2(X~) collisions

    NASA Astrophysics Data System (ADS)

    Tscherbul, T. V.; Grinev, T. A.; Yu, H.-G.; Dalgarno, A.; Kłos, Jacek; Ma, Lifang; Alexander, Millard H.

    2012-09-01

    We develop a rigorous quantum mechanical theory for collisions of polyatomic molecular radicals with S-state atoms in the presence of an external magnetic field. The theory is based on a fully uncoupled space-fixed basis set representation of the multichannel scattering wave function. Explicit expressions are presented for the matrix elements of the scattering Hamiltonian for spin-1/2 and spin-1 polyatomic molecular radicals interacting with structureless targets. The theory is applied to calculate the cross sections and thermal rate constants for spin relaxation in low-temperature collisions of the prototypical organic molecule methylene [CH_2(tilde{X}^3B_1)] with He atoms. To this end, two accurate three-dimensional potential energy surfaces (PESs) of the He-CH_2(tilde{X}^3B_1) complex are developed using the state-of-the-art coupled-cluster method including single and double excitations along with a perturbative correction for triple excitations and large basis sets. Both PESs exhibit shallow minima and are weakly anisotropic. Our calculations show that spin relaxation in collisions of CH2, CHD, and CD2 molecules with He atoms occurs at a much slower rate than elastic scattering over a large range of temperatures (1 μK-1 K) and magnetic fields (0.01-1 T), suggesting excellent prospects for cryogenic helium buffer-gas cooling of ground-state ortho-CH_2(tilde{X}^3B_1) molecules in a magnetic trap. Furthermore, we find that ortho-CH2 undergoes collision-induced spin relaxation much more slowly than para-CH2, which indicates that magnetic trapping can be used to separate nuclear spin isomers of open-shell polyatomic molecules.

  11. Cold collisions of polyatomic molecular radicals with S-state atoms in a magnetic field: an ab initio study of He + CH2(X) collisions.

    PubMed

    Tscherbul, T V; Grinev, T A; Yu, H-G; Dalgarno, A; Kłos, Jacek; Ma, Lifang; Alexander, Millard H

    2012-09-14

    We develop a rigorous quantum mechanical theory for collisions of polyatomic molecular radicals with S-state atoms in the presence of an external magnetic field. The theory is based on a fully uncoupled space-fixed basis set representation of the multichannel scattering wave function. Explicit expressions are presented for the matrix elements of the scattering Hamiltonian for spin-1/2 and spin-1 polyatomic molecular radicals interacting with structureless targets. The theory is applied to calculate the cross sections and thermal rate constants for spin relaxation in low-temperature collisions of the prototypical organic molecule methylene [CH(2)(X(3)B(1))] with He atoms. To this end, two accurate three-dimensional potential energy surfaces (PESs) of the He-CH(2)(X(3)B(1)) complex are developed using the state-of-the-art coupled-cluster method including single and double excitations along with a perturbative correction for triple excitations and large basis sets. Both PESs exhibit shallow minima and are weakly anisotropic. Our calculations show that spin relaxation in collisions of CH(2), CHD, and CD(2) molecules with He atoms occurs at a much slower rate than elastic scattering over a large range of temperatures (1 μK-1 K) and magnetic fields (0.01-1 T), suggesting excellent prospects for cryogenic helium buffer-gas cooling of ground-state ortho-CH(2)(X(3)B(1)) molecules in a magnetic trap. Furthermore, we find that ortho-CH(2) undergoes collision-induced spin relaxation much more slowly than para-CH(2), which indicates that magnetic trapping can be used to separate nuclear spin isomers of open-shell polyatomic molecules.

  12. Suppression of Zeeman relaxation in cold collisions of {sup 2}P{sub 1/2} atoms

    SciTech Connect

    Tscherbul, T. V.; Dalgarno, A.; Buchachenko, A. A.; Lu, M.-J.; Weinstein, J. D.

    2009-10-15

    We present a combined experimental and theoretical study of angular momentum depolarization in cold collisions of {sup 2}P atoms in the presence of an external magnetic field. We show that collision-induced Zeeman relaxation of Ga({sup 2}P{sub 1/2}) and In({sup 2}P{sub 1/2}) atoms in cold {sup 4}He gas is dramatically suppressed compared to atoms in {sup 2}P{sub 3/2} states. Using rigorous quantum-scattering calculations based on ab initio interaction potentials, we demonstrate that Zeeman transitions in collisions of atoms in {sup 2}P{sub 1/2} electronic states occur via couplings to the {sup 2}P{sub 3/2} state induced by the anisotropy of the interaction potential. Our results suggest the feasibility of sympathetic cooling and magnetic trapping of {sup 2}P{sub 1/2}-state atoms, such as halogens, thereby opening up exciting areas of research in precision spectroscopy and cold-controlled chemistry.

  13. Essay: Fifty years of atomic, molecular and optical physics in Physical Review Letters.

    PubMed

    Haroche, Serge

    2008-10-17

    The fiftieth anniversary of Physical Review Letters is a good opportunity to review the extraordinary progress of atomic, molecular, and optical physics reported in this journal during the past half-century. As both a witness and an actor of this story, I recall personal experiences and reflect about the past, present, and possible future of my field of research.

  14. Researches on interactions of satellite-speed helium atoms with aluminum and quartz surfaces. [atomic collisions with aluminum skin (structural member) of satellites (laboratory study)

    NASA Technical Reports Server (NTRS)

    Liu, S. M.; Knuth, E. L.

    1976-01-01

    Three major areas were experimentally studied: (1) energy transfer in collisions of satellite-speed (700 m/sec) helium atoms with a cleaned satellite-type aluminum surface was investigated using the molecular-beam technique. Spatial and energy distributions of reflected helium atoms were measured and analyzed, (2) The gross accommodation coefficient for a satellite-speed (7000 m/sec) helium beam entering a 2-inch-diameter aluminum spherical cavity was determined by measuring the exit velocity distribution of the leaving helium atoms using a metastable time-of-flight method. Results indicate that the 7000-m/sec satellite-speed helium atoms entering the cavity gain full accommodation with the room-temperature inner surface of the sphere through a large number of collisions before leaving the spherical cavity; and (3) the feasibility of producing a satellite-speed atomic hydrogen beam by arc-heating, for use in studies of interactions of satellite-surfaces with hydrogen atoms under laboratory conditions, was investigated. It was found that a stable arc-heated molecular hydrogen beam can be obtained using the arc-heater, and that a partially dissociated hydrogen beam can be produced. Photographs of laboratory equipment are shown.

  15. Physically representative atomistic modeling of atomic-scale friction

    NASA Astrophysics Data System (ADS)

    Dong, Yalin

    Nanotribology is a research field to study friction, adhesion, wear and lubrication occurred between two sliding interfaces at nano scale. This study is motivated by the demanding need of miniaturization mechanical components in Micro Electro Mechanical Systems (MEMS), improvement of durability in magnetic storage system, and other industrial applications. Overcoming tribological failure and finding ways to control friction at small scale have become keys to commercialize MEMS with sliding components as well as to stimulate the technological innovation associated with the development of MEMS. In addition to the industrial applications, such research is also scientifically fascinating because it opens a door to understand macroscopic friction from the most bottom atomic level, and therefore serves as a bridge between science and engineering. This thesis focuses on solid/solid atomic friction and its associated energy dissipation through theoretical analysis, atomistic simulation, transition state theory, and close collaboration with experimentalists. Reduced-order models have many advantages for its simplification and capacity to simulating long-time event. We will apply Prandtl-Tomlinson models and their extensions to interpret dry atomic-scale friction. We begin with the fundamental equations and build on them step-by-step from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. Theoretical analysis, numerical implementation, and predicted physical phenomena are all discussed. In the process, we demonstrate the significant potential for this approach to yield new fundamental understanding of atomic-scale friction. Atomistic modeling can never be overemphasized in the investigation of atomic friction, in which each single atom could play a significant role, but is hard to be captured experimentally. In atomic friction, the

  16. B physics at CDF - the Beauty of hadron collisions

    SciTech Connect

    Tonelli, Diego

    2010-11-01

    The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides an unique, rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B{sub s}{sup 0} mixing, and b {yields} s penguin decays.

  17. Electron emission in collisions of fast highly charged bare ions with helium atoms

    NASA Astrophysics Data System (ADS)

    Mondal, Abhoy; Mandal, Chittranjan; Purkait, Malay

    2016-01-01

    We have studied the electron emission from ground state helium atom in collision with fast bare heavy ions at intermediate and high incident energies. In the present study, we have applied the present three-body formalism of the three Coulomb wave (3C-3B) model and the previously adopted four-body formalism of the three Coulomb wave (3C-4B). To represent the active electron in the helium atom in the 3C-3B model, the initial bound state wavefunction is chosen to be hydrogenic with an effective nuclear charge. The wavefunction for the ejected electron in the exit channel has been approximated to be a Coulomb continuum wavefunction with same effective nuclear charge. Effectively the continuum-continuum correlation effect has been considered in the present investigation. Here we have calculated the energy and angular distribution of double differential cross sections (DDCS) at low and high energy electron emission from helium atom. The large forward-backward asymmetry is observed in the angular distribution which is explained in terms of the two-center effect (TCE). Our theoretical results are compared with available experimental results as well as other theoretical calculations based on the plain wave Born approximation (PWBA), continuum-distorted wave (CDW) approximation, continuum-distorted wave eikonal-initial state (CDW-EIS) approximation, and the corresponding values obtained from the 3C-4B model [S. Jana, R. Samanta, M. Purkait, Phys. Scr. 88, 055301 (2013)] respectively. It is observed that the four-body version of the present investigation produces results which are in better agreement with experimental observations for all cases.

  18. Impact Collision Ion Scattering Spectroscopy Applied to the Determination of Atomic Surface Structure

    NASA Astrophysics Data System (ADS)

    Daley, Richard Stephen

    1990-08-01

    The technique of impact collision ion scattering spectroscopy (ICISS) was used to investigate the atomic structure and low energy ion scattering dynamics from various surfaces. A new formalism for calculating the three-dimensional cross section for an ion to scatter sequentially and classically from two atoms has been developed. This method can be used to assist in the interpretation of ICISS data in terms of quantitative surface-structure models. Shadowing and blocking effects for energetic ions scattering from more than one atom are shown to be special cases of rainbow scattering. Even at keV energies and above, the cross section at the critical angle for scattering must be evaluated by quantum or semi-classical means to avoid the singularity in the classically calculated cross sections. In an ICISS investigation of the Ag(110) surface, a surface flux peak analysis demonstrated that the surface was not a complete monolayer, but rather contained 10-15% random vacancies. Subsurface Li^+ scattering results confirmed the oscillatory relaxation of the first two atomic layers of the surface, with Delta_{12} = -7.5% and Delta_{23} = 4.0%. Modeling of the neutralization mechanism for the He^+ scattering gave a best fit time-dependent Auger neutralization time constant of 0.84 +/- 0.08 fs. A neutralization study of 5 keV He^+ ions scattered from Au adatoms on the Si(111)- sqrt{3} x sqrt {3}-Au surface showed the He^+ ICISS data contained false shadowing features that were actually the result of local neutralization effects. Good agreement was obtained for a radially dependent ion-atom neutralization theory with rate R = Aexp (-ar) , where A and a are 15.5 fs^{ -1} and 1.94 A^{-1} , respectively. A detailed examination of the Si(111)- sqrt{3} x sqrt{3 })-Ag surface was also made. The 5 keV Li ^+ ICISS data gave evidence for Ag island formation at single monolayer coverages of silver, while the LEED, AES and LEIS data showed that at relatively high coverages of Ag (35 ML

  19. Sympathetic cooling of the Ba{sup +} ion by collisions with ultracold Rb atoms: Theoretical prospects

    SciTech Connect

    Krych, Michal; Skomorowski, Wojciech; Pawlowski, Filip; Moszynski, Robert; Idziaszek, Zbigniew

    2011-03-15

    nonrelativistic results and spin-orbit eigenvectors. The electronic structure input has been employed in the single-channel scattering calculations of the collisional cross sections between the Ba{sup +} ion and Rb atom. Both nonrelativistic and relativistic potentials were used in these calculations. Our results show that the inelastic cross section corresponding to the charge transfer from the Rb atom to the Ba{sup +} ion is much smaller than the elastic one over a wide range of energies up to 1 mK. This suggests that sympathetic cooling of the Ba{sup +} ion by collisions with ultracold Rb atoms should be possible.

  20. Low-energy electron collisions with quasi-two electron atoms

    NASA Astrophysics Data System (ADS)

    Bartschat, Klaus; Bray, Igor; Fursa, Dmitry

    2003-10-01

    We have recently investigated elastic electron scattering from quasi-two electron targets such as Mg, Zn, and Hg. Accurate total and momentum-transfer cross sections for these processes are of interest both for modelling transport processes in various lighting applications [1] and for the fundamental understanding of collision processes in magneto-optical traps and Bose-Einstein condensates [2]. To our big surprise, we found that a convergent description of these collisions within the close-coupling formalism is by no means trivial, since the theoretical results for the scattering lengths and the low-energy p-wave shape resonances, studied experimentally a long time ago [3], depend in a very sensitive way on the details of the numerical model. [1] G.G. Lister, in Low Temperature Plasma Physics (eds. R. Hippler, S. Pfau, M. Schmidt and K.H. Schoenbach), Wiley (New York, 2002) [2] K. Bartschat and H.R. Sadeghpour, J. Phys. B. 36 (2003) L9 [3] P.D. Burrow, J.A. Michejda and J. Comer, J. Phys. B. 9 (1976) 3225

  1. The Heidelberg test storage ring for heavy ions and its use for atomic physics

    SciTech Connect

    Schuch, R.

    1986-11-01

    A brief description of the Heavy-Ion Test Storage Ring (TSR) presently being built at the Max-Planck Institut in Heidelberg is given. It will be able to store ions injected from the tandem postaccelerator combination up to about 30 MeV/nucleon for a charge to mass ratio of 0.5. One of the main purposes of the TSR will be the study of electron cooling. Some atomic physics experiments are discussed using the electron cooling device which provides an electron-ion collision facility with good energy resolution and ion beams of high currents and low emittances. Here the possibilities for measurements of spontaneous and laser-induced radiative recombination and dielectronic recombination in the electron cooling section are discussed.

  2. The Broadening of Spectral Lines by Collisions with Neutral Hydrogen Atoms

    NASA Astrophysics Data System (ADS)

    Barklem, P. S.

    1998-10-01

    curves is examined. It is concluded that as found by Anstee and O'Mara (1991,1992) for s-p and p-s transitions, line broadening is insensitive to close collisions and most sensitive to intermediate range interactions. Evidence for this conclusion is presented. The influence of the use of the approximate value of Ep=-4/9 for the energy denominator on the broadening of neutral atom transitions is fully investigated. The dependence on the choice of Ep is shown to be small over the domain of expected values. Line broadening cross-section results are presented for selected specific transitions. Results are also presented in tabular form for cross-sections for general p-d, d-p, d-f and f-d transitions. The cross-sections are tabulated with effective principal quantum number for each state, for a relative perturber velocity of 104 m/s. The cross-sections are fitted to a power law relationship with velocity, of the form σ(v) ∝ vα. The velocity parameter α is similarly tabulated. The extent of the tables is such that most transitions corresponding to these angular momentum states, that will be astrophysically important, should fall within the tables. The results are tested by application to solar spectra. The data is applied to strong lines and abundances for these elements derived and compared with meteoritic abundances. The derived elemental abundances are found to be consistent with meteoritic and currently accepted values, to within the uncertainties in the f-values. Finally, the theory is extended to the broadening of spectral lines of singly ionised atoms. Required modifications to the current interaction potentials are presented. The use of the Unsöld approximation requires a slightly modified approach for ions. A method is presented for calculation of Ep that is suitable for the upper and lower states of strong transitions. Dispersion coefficients C6 and subsequent energy denominators E_p are presented for selected states of ionised atoms. Using these results

  3. Atomic and molecular theory

    SciTech Connect

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs.

  4. Intuitive Physics of Collision Effects on Simulated Spheres Differing in Size, Velocity, and Material

    ERIC Educational Resources Information Center

    Vicovaro, Michele

    2012-01-01

    This is an intuitive physics study of collision events. In two experiments the participants were presented with a simulated 3D scene showing one sphere moving horizontally towards another stationary sphere. The moving sphere stopped just before colliding with the stationary one. Participants were asked to rate the positions which both spheres…

  5. Electron capture in collisions of Al2+ ions with He atoms at intermediate energies

    NASA Astrophysics Data System (ADS)

    Watanabe, A.; Sato, H.; Gu, J. P.; Hirsch, G.; Buenker, R. J.; Kimura, M.

    2001-09-01

    Electron capture resulting from collisions of Al2+ ions with He atoms from 0.15 to 1000 keV/u is investigated using a molecular-orbital representation within a semiclassical frame. Molecular electronic states and corresponding couplings are determined by the ALCHEMY program. Sixteen molecular states all connecting to single-electron-capture processes are included, and hence radial and rotational couplings among these channels are fully considered. The trajectory effect arising from the straight-line, Coulomb, and ground-state potential trajectories for electron-capture and excitation processes is carefully assessed. The electron-capture cross section by ground-state Al2+(2S) ions slowly increases before it reaches a maximum of 1.3×10-16 cm2 at 100 keV/u. Those for metastable Al2+(2P) ions sharply increase with increasing energy, and reach a peak at 1 keV/u with a value of 1.5×10-16 cm2. The earlier experimental data are found to be larger by an order of magnitude although their energy dependence is in good accord with the present result. Excitation cross sections for both the ground and metastable states are found to be much larger by a factor of 2-3 than corresponding capture cross sections above 1 keV/u although they become comparable below this energy.

  6. Organic surfaces excited by low-energy ions: atomic collisions, molecular desorption and buckminsterfullerenes.

    PubMed

    Delcorte, Arnaud

    2005-10-07

    This article reviews the recent progress in the understanding of kiloelectronvolt particle interactions with organic solids, including atomic displacements in a light organic medium, vibrational excitation and desorption of fragments and entire molecules. This new insight is the result of a combination of theoretical and experimental approaches, essentially molecular dynamics (MD) simulations and secondary ion mass spectrometry (SIMS). Classical MD simulations provide us with a detailed microscopic view of the processes occurring in the bombarded target, from the collision cascade specifics to the scenarios of molecular emission. Time-of-flight SIMS measures the mass and energy distributions of sputtered ionized fragments and molecular species, a precious source of information concerning their formation, desorption, ionization and delayed unimolecular dissociation in the gas phase. The mechanisms of energy transfer and sputtering are compared for bulk molecular solids, organic overlayers on metal and large molecules embedded in a low-molecular weight matrix. These comparisons help understand some of the beneficial effects of metal substrates and matrices for the analysis of molecules by SIMS. In parallel, I briefly describe the distinct ionization channels of molecules sputtered from organic solids and overlayers. The specific processes induced by polyatomic projectile bombardment, especially fullerenes, are discussed on the basis of new measurements and calculations. Finally, the perspective addresses the state-of-the-art and potential developments in the fields of surface modification and analysis of organic materials by kiloelectronvolt ion beams.

  7. Ultracold photoassociative ionization collisions in an atomic beam: Optical field intensity and polarization dependence of the rate constant

    SciTech Connect

    Tsao, C.; Napolitano, R.; Wang, Y.; Weiner, J. )

    1995-01-01

    We report here measurements of two-body photoassociative ionization collisions between sodium atoms within an ultranarrow velocity class selected from a well-collimated, thermal atomic beam. Doppler-shifted excitation of the Na(3[ital s] [sup 2][ital S][sub 1/2];[ital F]=1)[r arrow]Na(5[ital p] [sup 2][ital P][sub 3/2]) transition at 285 nm by a single-mode laser defines the narrow velocity class that subsequently populates the [ital F]=2 hyperfine level of the Na ground state by optical pumping. Probe laser beam excitation tuned near the Na(3[ital s] [sup 2][ital S][sub 1/2];[ital F]=2)[r arrow]Na(3[ital p] [sup 2][ital P][sub 3/2];[ital F]=3) transition produced photoassociative ionization with an average collision energy [ital E][sub [ital K

  8. Positron-electron correlation-polarization potentials for the calculation of positron collisions with atoms and molecules*

    NASA Astrophysics Data System (ADS)

    Franz, Jan

    2017-02-01

    We present correlation-polarization potentials for the calculation of scattering cross sections of positrons with atoms and molecules. The potentials are constructed from a short-range correlation term and a long-range polarization term. For the short-range correlation term we present four different potentials that are derived from multi-component density functionals. For the long-range polarization term we employ a multi-term expansion. Quantum scattering calculations are presented for low energy collisions of positrons with two atomic targets (argon and krypton) and two molecular targets (nitrogen and methane). For collision energies below the threshold for Positronium formation our calculations of scattering cross sections are in good agreement with recent data sets from experiments and theory. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic and B. Sivaraman.

  9. An independent atom model description of ion-molecule collisions including geometric screening corrections: application to biomolecules

    NASA Astrophysics Data System (ADS)

    Lüdde, H. J.; Achenbach, A.; Kalkbrenner, T.; Jankowiak, H. C.; Kirchner, T.

    2016-09-01

    Recently, we proposed to calculate electron removal cross sections for ion-molecule collisions in an independent atom model that accounts for geometric screening corrections. The correction coefficients are obtained from using a pixel counting method (PCM) for the exact calculation of the effective cross sectional area that emerges when the molecular cross section is pictured as a structure of (overlapping) atomic cross sections. This structure varies with the relative orientation of the molecule with respect to the projectile beam direction and, accordingly, orientation-independent total cross sections are obtained from averaging the pixel count over many orientations. In this contribution, we apply the PCM to proton collisions from amino acids and DNA and RNA nucleobases. The strength of the screening effect is analyzed by comparing the PCM results with Bragg additivity rule cross sections and with experimental data where available. Work supported by NSERC, Canada.

  10. Analysis of the physical atomic forces between noble gas atoms, alkali ions and halogen ions

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Heinbockel, J. H.; Outlaw, R. A.

    1986-01-01

    The physical forces between atoms and molecules are important in a number of processes of practical importance, including line broadening in radiative processes, gas and crystal properties, adhesion, and thin films. The components of the physical forces between noble gas atoms, alkali ions, and halogen ions are analyzed and a data base for the dispersion forces is developed from the literature based on evaluations with the harmonic oscillator dispersion model for higher order coefficients. The Zener model of the repulsive core is used in the context of the recent asymptotic wave functions of Handler and Smith; and an effective ionization potential within the Handler and Smith wave functions is defined to analyze the two body potential data of Waldman and Gordon, the alkali-halide molecular data, and the noble gas crystal and salt crystal data. A satisfactory global fit to this molecular and crystal data is then reproduced by the model to within several percent. Surface potentials are evaluated for noble gas atoms on noble gas and salt crystal surfaces with surface tension neglected. Within this context, the noble gas surface potentials on noble gas and salt crystals are considered to be accurate to within several percent.

  11. Vortices Associated with the Wave Function of a Single Electron Emitted in Slow Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Schmidt, L. Ph. H.; Goihl, C.; Metz, D.; Schmidt-Böcking, H.; Dörner, R.; Ovchinnikov, S. Yu.; Macek, J. H.; Schultz, D. R.

    2014-02-01

    We present measurements and calculations of the momentum distribution of electrons emitted during the ion-atom collision 10 keV/u He2++He→He++He2++e-, which show rich structures for ion scattering angles above 2 mrad arising dominantly from two-electron states. Our calculations reveal that minima in the measured distributions are zeros in the electronic probability density resulting from vortices in the electronic current.

  12. Ionization collisions between two excited atoms: Application of the Glauber amplitude in the framework of the impulse approximation

    SciTech Connect

    Shirai, T.; Nakai, Y.; Nakamura, H.

    1984-10-01

    The cross-section formula of Flannery (Phys. Rev. A 22, 2408 (1980)) in the semiquantal approximation for the processes referred to in the title is rewritten so as to make it more useful in practice. The formula is shown to be further simplified by taking an average over the azimuthal quantum number of a highly excited hydrogenic atom to be ionized. Numerical applications with use of the Glauber amplitude for the electron-atom inelastic scattering are made to the ionization collisions between two excited hydrogen atoms with simultaneous excitation and deexcitation of one of the atoms. The results are compared with those obtained by using the Born amplitude, and are analyzed in terms of the Glauber generalized oscillator strengths.

  13. Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

    NASA Technical Reports Server (NTRS)

    Kohel, James M.

    2012-01-01

    Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

  14. Atomic physics measurements using an ECR ion source located on a 350-kV high-voltage platform

    SciTech Connect

    Dunford, R.W.; Berry, H.G.; Liu, C.J.; Hass, M.; Pardo, R.C.; Raphaelian, M.L.A.; Zabransky, B.J.

    1988-01-01

    We report on a new atomic physics facility at the Argonne PII ECR ion source which was built for the Uranium Upgrade of the ATLAS heavy-ion accelerator. An important feature of our ECR ion source is that it is on a high-voltage platform which provides beam energies of up to 350q keV, where q is the charge of the ion. We discuss the experimental program in progress at this ion source which includes measurements of state-selective electron capture cross sections, photon and electron spectroscopy, studies of quasi-molecular collisions, and polarization studies using an optically pumped Na target. 9 refs., 6 figs.

  15. ITER core imaging X-ray spectroscopy: Atomic physics issues

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.; Clementson, J.; Widmann, K.; Bitter, M.; Hill, K. W.; Johnson, D.; Barnsley, R.; Chung, H. K.; Safronova, U. I.

    2017-03-01

    The Core Imaging X-Ray Spectrometer (CIXS) will be employed for measurements of the ion temperature and of the toroidal rotation velocity, Ti and vϕ, respectively, as a function of the radius of ITER plasmas. The diagnostic is based on precision determinations of the Doppler broadening, centroid shift, and intensity of the lines of highly ionized heavy impurities using a curved Bragg crystal spectral disperser and imager. The ions under consideration for the diagnostic are those of tungsten, krypton, xenon, iron, and argon. A detailed discussion is given of the need for atomic physics experiments and calculations involving the primary diagnostic lines and their collisional and dielectronic satellites. Such experiments and calculations define the instrument parameters, determine the diagnostic uncertainties, and provide paths for extending the diagnostic capabilities to measure impurity concentrations, electron temperature, and ion transport parameters. Enabling the diagnostic to measure radially dependent ion transport coefficients, in particular, requires a large amount of high-quality atomic data in the form of reliable excitation, ionization, and recombination rate coefficients as well as ionization balance calculations which make use of these data. Because core imaging spectrometers are being developed and implemented on present-day magnetic fusion devices, much of the atomic data are already needed and can be tested in the analysis of existing spectra recorded by these diagnostics.

  16. Recent advances in Rydberg physics using alkaline-earth atoms

    NASA Astrophysics Data System (ADS)

    Dunning, F. B.; Killian, T. C.; Yoshida, S.; Burgdörfer, J.

    2016-06-01

    In this brief review, the opportunities that the alkaline-earth elements offer for studying new aspects of Rydberg physics are discussed. For example, the bosonic alkaline-earth isotopes have zero nuclear spin which eliminates many of the complexities present in alkali Rydberg atoms, permitting simpler and more direct comparison between theory and experiment. The presence of two valence electrons allows the production of singlet and triplet Rydberg states that can exhibit a variety of attractive or repulsive interactions. The availability of weak intercombination lines is advantageous for laser cooling and for applications such as Rydberg dressing. Excitation of one electron to a Rydberg state leaves behind an optically active core ion allowing, for high-L states, the optical imaging of Rydberg atoms and their (spatial) manipulation using light scattering. The second valence electron offers the possibility of engineering long-lived doubly excited states such as planetary atoms. Recent advances in both theory and experiment are highlighted together with a number of possible directions for the future.

  17. Atomic, Molecular, and Optical Physics Workshop Final Report

    SciTech Connect

    Armstrong, Jr., Lloyd

    1997-09-21

    This document contains the final reports from the five panels that comprised a Workshop held to explore future directions, scientific impacts and technological connections of research in Atomic, Molecular and Optical Physics. This workshop was sponsored by the Department of Energy, Office of Basic Energy Sciences, Chemical Sciences Division and was held at the Westfields International Conference Center in Chantilly, Virginia on September 21-24, 1997. The workshop was chaired by Lloyd Armstrong, Jr., University of Southern California and the five panels focused on the following topics: Panel A: Interactions of Atoms and Molecules with Photons - Low Field Daniel Kleppner (Massachusetts Institute of Technology), chair Panel B: Interactions of Atoms and Molecules with Photons - High Field Phil Bucksbaum (University of Michigan), chair Panel C: Surface Interactions with Photons, Electrons, Ions, Atoms and Molecules J. Wayne Rabalais (University of Houston), chair Panel D: Theory of Structure and Dynamics Chris Greene (University of Colorado), chair Panel E: Nano- and Mesocopic Structures Paul Alivisatos (Lawrence Berkeley National Laboratory), chair The choice of focus areas reflects areas of significant interest to DOE/BES but is clearly not intended to span all fields encompassed by the designation of atomic, molecular and optical physics, nor even all areas that would be considered for review and funding under DOE’s AMOP program. In a similar vein, not all research that might be suggested under these topics in this report would be appropriate for consideration by DOE’s AMOP program. The workshop format included overview presentations from each of the panel chairs, followed by an intensive series of panel discussion sessions held over a two-day period. The panels were comprised of scientists from the U. S. and abroad, many of whom are not supported by DOE’s AMOP Program. This workshop was held in lieu of the customary “Contractors Meeting” held annually for

  18. The Physical Conditions of Atomic Gas at High Redshift

    NASA Astrophysics Data System (ADS)

    Neeleman, Marcel

    In this thesis we provide insight into the chemical composition, physical conditions and cosmic distribution of atomic gas at high redshift. We study this gas in absorption against bright background quasars in absorption systems known as Damped Ly-alpha Systems (DLAs). These systems contain the bulk of the atomic gas at high redshift and are the likely progenitors of modern-day galaxies. In Chapter 2, we find that the atomic gas in DLAs obeys a mass-metallicity relationship that is similar to the mass-metallicity relationship seen in star-forming galaxies. The evolution of this relationship is linear with redshift, allowing for a planar equation to accurately describe this evolution, which provides a more stringent constraint on simulations modeling DLAs. Furthermore, the concomitant evolution of the mass-metallicity relationship of atomic gas and star-forming galaxies suggests an intimate link between the two. We next use a novel way to measure the physical conditions of the gas by using fine-structure line ratios of singly ionized carbon and silicon. By measuring the density of the upper and lower level states, we are able to determine the temperature, hydrogen density and electron density of the gas. We find that the conditions present in this high redshift gas are consistent with the conditions we see in the local interstellar medium (ISM). A few absorbers have higher than expected pressure, which suggests that they probe the ISM of star-forming galaxies. Finally in Chapter 4, we measure the cosmic neutral hydrogen density at redshifts below 1.6. Below this redshift, the Ly-alpha line of hydrogen is absorbed by the atmosphere, making detection difficult. Using the archive of the Hubble Space Telescope, we compile a comprehensive list of quasars for a search of DLAs at redshift below 1.6. We find that the incidence rate of DLAs and the cosmic neutral hydrogen density is smaller than previously measured, but consistent with the values both locally and at

  19. Charge transfer in collisions of Be3+ ions with H atoms

    NASA Astrophysics Data System (ADS)

    Liu, C. H.; Wang, J. G.

    2013-04-01

    The nonradiative charge-transfer processes for the Be3+(1s)+H(1s) collisions are investigated by the quantum-mechanical molecular orbital close-coupling method in the energy range of 0.01-10 keV/u. The radiative charge-transfer cross sections are calculated by the optical potential and semiclassical methods in the energy range 10-6-103 eV/u. The needed molecular data are obtained by the ab initio multireference single- and double-excitation configuration interaction method. Total and state-selective cross sections are presented and compared with other available theoretical data. Our calculation agrees well with the atomic orbital close-coupling results of Liu [L. Liu, D. Jakimovski, J. G. Wang, and R. K. Janev, J. Phys. BJPAPEH0953-407510.1088/0953-4075/43/14/144005 43, 144005 (2010)], but there exist some discrepancies with the semiclassical molecular orbital close-coupling results of Shimakura [N. Shimakura, J. Phys. BJPAMA40953-407510.1088/0953-4075/21/13/015 21, 2485 (1988)]. The present results show that the capture to Si2+(1s3l) states is dominant in the whole energy range with the exception of a narrow range of 2-4 keV/u. Rotational couplings play an important role not only in the state-selective cross sections, but also in the total charge-transfer results. At energies below 40 eV/u, the radiative charge transfer exceeds the nonradiative process.

  20. Davisson-Germer Prize in Atomic or Surface Physics Lecture: Exploring Flatland with Cold Atoms

    NASA Astrophysics Data System (ADS)

    Dalibard, Jean

    2012-06-01

    A two-dimensional Bose fluid is a remarkably rich many-body system, which allows one to revisit several features of quantum statistical physics. Firstly, the role of thermal fluctuations is enhanced compared to the 3D case, which destroys the ordered state associated with Bose-Einstein condensation. However interactions between particles can still cause a superfluid transition, thanks to the Berezinskii-Kosterlitz-Thouless mechanism. Secondly, a weakly interacting Bose fluid in 2D must be scale-invariant, a remarkable feature that manifests itself in the very simple form taken by the equation of state of the fluid. In this talk I will present recent experimental progress in the investigation of 2D atomic gases, which provide a nice illustration of the main features of low dimensional many-body physics.

  1. Atomic physics with highly charged ions. Progress report, 15 September 1984-14 September 1985

    SciTech Connect

    Richard, P.

    1985-09-01

    Advances are reported in the two areas of primary research: low-energy ion-atom collisions using secondary ion recoil sources, SIRS, and high-energy ion-atom collisions using the tandem Van de Graaff accelerator beams. We have investigated the feasibility of accel-decel with a tandem plus superconducting LINAC with great success, and we have continued to work on the designs of a stand-alone CRYEBIS and a superconducting Nb split-ring resonator LINAC as an appropriate booster for the EN tandem.

  2. Atom optics and space physics: A summary of an 'Enrico Fermi' summer school

    NASA Astrophysics Data System (ADS)

    Arimondo, Ennio; Ertmer, Wolfgang; Rasel, Ernst M.; Schleich, Wolfgang P.

    2008-03-01

    We describe the scientific content of the International School of Physics 'Enrico Fermi' on atom optics and space physics, organized by the Italian Physical Society in Varenna at Lake Como, Italy, 2-13 July 2007.

  3. Formation of Triplet Positron-helium Bound State by Stripping of Positronium Atoms in Collision with Ground State Helium

    NASA Technical Reports Server (NTRS)

    Drachman, Richard J.

    2006-01-01

    Formation of triplet positron-helium bound state by stripping of positronium atoms in collision with ground state helium JOSEPH DI RlENZI, College of Notre Dame of Maryland, RICHARD J. DRACHMAN, NASA/Goddard Space Flight Center - The system consisting of a positron and a helium atom in the triplet state e(+)He(S-3)(sup e) was conjectured long ago to be stable [1]. Its stability has recently been established rigorously [2], and the values of the energies of dissociation into the ground states of Ps and He(+) have also been reported [3] and [4]. We have evaluated the cross-section for this system formed by radiative attachment of a positron in triplet He state and found it to be small [5]. The mechanism of production suggested here should result in a larger cross-section (of atomic size) which we are determining using the Born approximation with simplified initial and final wave functions.

  4. Atomic and molecular collision aspects of thermospheric uranium-vapor releases. Technical report, 15 February 1980-31 December 1985

    SciTech Connect

    Hamlin, D.A.

    1990-05-01

    The DNA Uranium (Oxides) LWIR Review Committee considered the effectiveness of field measurements of the LWIR from uranium oxides produced by (hypothetical) controlled releases of uranium vapor from rockets in the thermosphere. Collated here is the writer's work supporting the committee on atomic and molecular collision aspects of such releases. Included is an essential auxiliary study to (a) understand, in terms of atomic and molecular parameters, coefficients for Ba+ diffusion along the magnetic field as measured and predicted for Ba-release events and (b) apply that (limited) understanding to U-release studies. For particles colliding with neutral atmospheric species, several interaction potentials are used to compute velocity-dependent momentum-transfer cross sections, stopping power and range versus energy, and diffusion coefficients. The momentum-transfer cross sections are also compared with cross sections for certain uranium oxide reactions specially atom-transfer reactions.

  5. Probing non-Hermitian physics with flying atoms

    NASA Astrophysics Data System (ADS)

    Wen, Jianming; Xiao, Yanhong; Peng, Peng; Cao, Wanxia; Shen, Ce; Qu, Weizhi; Jiang, Liang

    2016-05-01

    Non-Hermtian optical systems with parity-time (PT) symmetry provide new means for light manipulation and control. To date, most of experimental demonstrations on PT symmetry rely on advanced nanotechnologies and sophisticated fabrication techniques to manmade solid-state materials. Here, we report the first experimental realization of optical anti-PT symmetry, a counterpart of conventional PT symmetry, in a warm atomic-vapor cell. By exploiting rapid coherence transport via flying atoms, we observe essential features of anti-PT symmetry with an unprecedented precision on phase-transition threshold. Moreover, our system allows nonlocal interference of two spatially-separated fields as well as anti-PT assisted four-wave mixing. Besides, another intriguing feature offered by the system is refractionless (or unit-refraction) light propagation. Our results thus represent a significant advance in non-Hermitian physics by bridging a firm connection with the AMO field, where novel phenomena and applications in quantum and nonlinear optics aided by (anti-)PT symmetry can be anticipated.

  6. Efimov Physics in a 6Li-133Cs Atomic Mixture

    NASA Astrophysics Data System (ADS)

    Johansen, Jacob; Feng, Lei; Parker, Colin; Chin, Cheng; Wang, Yujun

    2015-05-01

    We investigate Efimov physics based on three-body recombination in an atomic mixture of 6Li and 133Cs in the vicinity of interspecies Feshbach resonances at 843 and 889 G. This allows us to compare the loss spectra near different resonances and test the universality of Efimov states. Theoretically the Efimov spectrum near 889 G is expected to be similar to that near 843 G, except that the first resonance is absent near the former Feshbach resonance. This is due to the difference in the Cs-Cs scattering length near the two resonances: At 843 G it is negative, whereas at 889 G it is positive. Although it is primarily the Li-Cs interactions that lead to Efimov resonances, the Cs-Cs scattering length is expected to influence the spectrum. This work is supported by NSF and Chicago MRSEC.

  7. Research opportunities in atomic physics at the Advanced Light Source

    NASA Astrophysics Data System (ADS)

    Schlachter, A. S.; Robinson, A. L.

    1989-09-01

    The Advanced Light Source (ALS) now under construction at the Lawrence Berkeley Laboratory is being planned as a national user facility for the production of high-brightness and partially coherent X-ray and ultraviolet synchrotron radiation. The ALS is based on a low-emittance electron storage ring optimized for operation at 1.5 GeV with insertion devices in 11 long straight sections and up to 48 bending-magnet ports. High-brightness photon beams from less than 10 eV to more than 1 keV will be produced by undulators, thereby providing many research opportunities in atomic and molecular physics and chemistry. Wigglers and bending magnets will provide high-flux broad-band radiation at energies to 10 keV.

  8. Probing physical properties at the nanoscale using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ditzler, Lindsay Rachel

    Techniques that measure physical properties at the nanoscale with high sensitivity are significantly limited considering the number of new nanomaterials being developed. The development of atomic force microscopy (AFM) has lead to significant advancements in the ability to characterize physical properties of materials in all areas of science: chemistry, physics, engineering, and biology have made great scientific strides do to the versatility of the AFM. AFM is used for quantification of many physical properties such as morphology, electrical, mechanical, magnetic, electrochemical, binding interactions, and protein folding. This work examines the electrical and mechanical properties of materials applicable to the field of nano-electronics. As electronic devices are miniaturized the demand for materials with unique electrical properties, which can be developed and exploited, has increased. For example, discussed in this work, a derivative of tetrathiafulvalene, which exhibits a unique loss of conductivity upon compression of the self-assembled monolayer could be developed into a molecular switch. This work also compares tunable organic (tetraphenylethylene tetracarboxylic acid and bis(pyridine)s assemblies) and metal-organic (Silver-stilbizole coordination compounds) crystals which show high electrical conductivity. The electrical properties of these materials vary depending on their composition allowing for the development of compositionally tunable functional materials. Additional work was done to investigate the effects of molecular environment on redox active 11-ferroceneyl-1 undecanethiol (Fc) molecules. The redox process of mixed monolayers of Fc and decanethiol was measured using conductive probe atomic force microscopy and force spectroscopy. As the concentration of Fc increased large, variations in the force were observed. Using these variations the number of oxidized molecules in the monolayer was determined. AFM is additionally capable of investigating

  9. [Electron transfer, ionization, and excitation in atomic collisions]. Final technical report, June 15, 1986--June 14, 1998

    SciTech Connect

    1998-12-31

    The research on theoretical atomic collisions that was funded at The Pennsylvania State University`s Wilkes-Barre Campus by DOE from 1986 to 1998 was carried out by Winger from 1986 to 1989 and by Winter and Alston from 1989 to 1998. The fundamental processes of electron transfer, ionization, and excitation in ion-ion, ion-atom, and, more recently, ion-molecule collisions were addressed. These collision processes were treated in the context of simple one-electron, quasi-one-electron, or two-electron systems in order to provide unambiguous results and reveal more clearly the collisional mechanisms. Winter`s work generally focused on the intermediate projectile-energy range corresponding to proton energies from about ten to a few hundred keV. In this velocity-matching energy range, the electron-transfer cross section reaches a peak, and many states, including electron-transfer and ionization states, contribute to the overall electron-cloud distribution and transition probabilities; a large number of states are coupled, and therefore perturbative approaches are generally inappropriate. These coupled-state calculations were sometimes also extended to higher energies to join with perturbative results. Alston concentrated on intermediate-energy asymmetric collision systems, for which coupling with the projectile is weaker, but many target states are included, and on high energies (MeV energies). Thus, while perturbation theory for electron transfer is valid, it is not adequate to first order. The studies by Winter and Alston described were often done in parallel. Alston also developed formal perturbative approaches not tied to any particular system. Materials studied included He{sup +}, Li{sup 2+}, Be{sup 3+}, B{sup 4+}, C{sup 5+}, and the H{sup +} + Na system.

  10. Atomic physics with highly charged ions. Progress report, FY 1989--91

    SciTech Connect

    Richard, P.

    1991-08-01

    This report discusses: One electron outer shell processes in fast ion-atom collisions; role of electron-electron interaction in two-electron processes; multi-electron processes at low energy; multi-electron processes at high energy; inner shell processes; molecular fragmentation studies; theory; and, JRM laboratory operations.

  11. Scattering of NH{sub 3} and ND{sub 3} with rare gas atoms at low collision energy

    SciTech Connect

    Loreau, J.

    2015-11-14

    We present a theoretical study of elastic and rotationally inelastic collisions of NH{sub 3} and ND{sub 3} with rare gas atoms (He, Ne, Ar, Kr, Xe) at low energy. Quantum close-coupling calculations have been performed for energies between 0.001 and 300 cm{sup −1}. We focus on collisions in which NH{sub 3} is initially in the upper state of the inversion doublet with j = 1, k = 1, which is the most relevant in an experimental context as it can be trapped electrostatically and Stark-decelerated. We discuss the presence of resonances in the elastic and inelastic cross sections, as well as the trends in the inelastic cross sections along the rare gas series and the differences between NH{sub 3} and ND{sub 3} as a colliding partner. We also demonstrate the importance of explicitly taking into account the umbrella (inversion) motion of NH{sub 3} in order to obtain accurate scattering cross sections at low collision energy. Finally, we investigate the possibility of sympathetic cooling of ammonia using cold or ultracold rare gas atoms. We show that some systems exhibit a large ratio of elastic to inelastic cross sections in the cold regime, which is promising for sympathetic cooling experiments. The close-coupling calculations are based on previously reported ab initio potential energy surfaces for NH{sub 3}–He and NH{sub 3}–Ar, as well as on new, four-dimensional, potential energy surfaces for the interaction of ammonia with Ne, Kr, and Xe, which were computed using the coupled-cluster method and large basis sets. We compare the properties of the potential energy surfaces corresponding to the interaction of ammonia with the various rare gas atoms.

  12. Precision measurements of cross-sections for inelastic processes in collisions of alkali metal ions with atoms of rare gases

    NASA Astrophysics Data System (ADS)

    Lomsadze, R. A.; Gochitashvili, M. R.; Kezerashvili, R. Ya.

    2017-01-01

    A multifaceted experimental study of collisions of Na+ and K+ ions in the energy range of 0.5-10 keV with He and Ar atoms is presented. Absolute cross-sections for charge-exchange, ionization, stripping and excitation processes were measured using a refined version of the transfer electric field method, angle- and energy-dependent collection of product ions, energy loss and optical spectroscopy methods. The experimental data and the schematic correlation diagrams are employed to analyze and determine the mechanisms for these processes.

  13. Toward a deeper understanding of how experiments constrain the underlying physics of heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Sangaline, Evan; Pratt, Scott

    2016-02-01

    Recent work has provided the means to rigorously determine properties of superhadronic matter from experimental data through the application of broad scale modeling of high-energy nuclear collisions within a Bayesian framework. These studies have provided unprecedented statistical inferences about the physics underlying nuclear collisions by virtue of simultaneously considering a wide range of model parameters and experimental observables. Notably, this approach has been used to constrain both the QCD equation of state and the shear viscosity above the quark-hadron transition. Although the inferences themselves have a clear meaning, the complex nature of the relationships between model parameters and observables has remained relatively obscure. We present here a novel extension of the standard Bayesian Markov-chain Monte Carlo approach that allows for the quantitative determination of how inferences of model parameters are driven by experimental measurements and their uncertainties. This technique is then applied in the context of heavy-ion collisions in order to explore previous results in greater depth. The resulting relationships are useful for identifying model weaknesses, prioritizing future experimental measurements, and, most importantly, developing an intuition for the roles that different observables play in constraining our understanding of the underlying physics.

  14. Quantum study of Eley-Rideal reaction and collision induced desorption of hydrogen atoms on a graphite surface. II. H-physisorbed case.

    PubMed

    Martinazzo, Rocco; Tantardini, Gian Franco

    2006-03-28

    Following previous investigation of collision induced (CI) processes involving hydrogen atoms chemisorbed on graphite [R. Martinazzo and G. F. Tantardini, J. Chem. Phys. 124, 124702 (2006)], the case in which the target hydrogen atom is initially physisorbed on the surface is considered here. Several adsorbate-substrate initial states of the target H atom in the physisorption well are considered, and CI processes are studied for projectile energies up to 1 eV. Results show that (i) Eley-Rideal cross sections at low collision energies may be larger than those found in the H-chemisorbed case but they rapidly decrease as the collision energy increases; (ii) product hydrogen molecules are vibrationally very excited; (iii) collision induced desorption cross sections rapidly increase, reaching saturation values greater than 10 A2; (iv) trapping of the incident atoms is found to be as efficient as the Eley-Rideal reaction at low energies and remains sizable (3-4 A2) at high energies. The latter adsorbate-induced trapping results mainly in formation of metastable hot hydrogen atoms, i.e., atoms with an excess energy channeled in the motion parallel to the surface. These atoms might contribute in explaining hydrogen formation on graphite.

  15. Physics perspectives of heavy-ion collisions at very high energy

    DOE PAGES

    Chang, Ning-bo; Cao, ShanShan; Chen, Bao-yi; ...

    2016-01-15

    We expect heavy-ion collisions at very high colliding energies to produce a quark-gluon plasma (QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We also report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching, heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. Here, we illustrate the potential of future experimental studies of the initial particle production andmore » formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.« less

  16. Physics perspectives of heavy-ion collisions at very high energy

    SciTech Connect

    Chang, Ning-bo; Cao, ShanShan; Chen, Bao-yi; Chen, Shi-yong; Chen, Zhen-yu; Ding, Heng-Tong; He, Min; Liu, Zhi-quan; Pang, Long-gang; Qin, Guang-you; Rapp, Ralf; Schenke, Björn; Shen, Chun; Song, HuiChao; Xu, Hao-jie; Wang, Qun; Wang, Xin-Nian; Zhang, Ben-wei; Zhang, Han-zhong; Zhu, XiangRong; Zhuang, Peng-fei

    2016-01-15

    We expect heavy-ion collisions at very high colliding energies to produce a quark-gluon plasma (QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We also report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching, heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. Here, we illustrate the potential of future experimental studies of the initial particle production and formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.

  17. Measurements of scattering processes in negative ion: Atom collisions. Technical progress report, 1 September 1991--31 December 1994

    SciTech Connect

    Kvale, T.J.

    1994-09-27

    This report describes the progress made on the research objectives during the past three years of the grant. This research project is designed to study various scattering processes which occur in H{sup {minus}} collisions with atomic (specifically, noble gas and atomic hydrogen) targets in the intermediate energy region. These processes include: elastic scattering, single- and double-electron detachment, and target excitation/ionization. For the elastic and target inelastic processes where H{sup {minus}} is scattered intact, the experimental technique of Ion Energy-Loss Spectroscopy (IELS) will be employed to identify the final target state(s). In most of the above processes, cross sections are unknown both experimentally and theoretically. The measurements will provide total cross sections (TCS) initially, and once the angular positioning apparatus is installed, will provide angular differential cross sections (ADCS).

  18. ATOMIC PHYSICS, AN AUTOINSTRUCTIONAL PROGRAM, VOLUME 1, SUPPLEMENT.

    ERIC Educational Resources Information Center

    DETERLINE, WILLIAM A.; KLAUS, DAVID J.

    AUTOINSTRUCTIONAL MATERIALS WERE PREPARED FOR USE IN AN EXPERIMENTAL STUDY OF THE SELF-TUTORING APPROACH IN EDUCATION. THE MATERIALS COVER SECTIONS ON (1) THE ATOM, (2) ATOMIC PARTICLES, (3) CATHODE RAYS, (4) MEASURING THE ELECTRON, (5) CHARGE AND MASS OF THE ELECTRON, AND (6) MASS OF ATOMS. RELATED REPORTS ARE ED 003 205 THROUGH ED 003 207, ED…

  19. Nonadiabatic semiclassical scattering: Atom-diatom collisions in self-consistent matrix propagator formalism

    NASA Astrophysics Data System (ADS)

    Herman, Michael F.; Freed, Karl F.

    1983-05-01

    The self-consistent matrix propagator method of Laing and Freed is extended to treat semiclassical nonadiabatic scattering in the collinear atom-diatom system. Applications are made to a model system in which diabatic surfaces are parallel, so the nonadiabatic transitions are not well localized in space, thereby introducing difficulties in some previous nonadiabatic semiclassical methods. In the self-consistent matrix propagator method nonadiabatic transitions occur at the boundaries of Magnus regions, and the relative phases, associated with trajectories undergoing transitions at different boundaries, must accurately be determined. This necessitates the determination of the absolute phases of the uniformized classical S matrix, a phase which is unnecessary in single potential surface semiclassical scattering. Semiclassical calculations are compared with full close coupled quantum calculations of Schmalz. The agreement is very good even at relatively low energies. The largest errors enter, as anticipated, for highly classically forbidden transitions whose overall probabilities are, however, rather small. The self-consistent matrix propagator method becomes simpler to apply and more accurate as the total energy increases, i.e., as the fully quantum calculations become prohibitively large. The method has the physical appeal that the self-consistent trajectories follow essentially adiabatic surfaces in strongly interacting regions and diabatic surfaces in weakly interacting regions, with a self-consistent interpolation between these regions.

  20. Collisions of energetic particles with atoms, molecules & solids: A theoretical study

    NASA Astrophysics Data System (ADS)

    Quashie, Edwin Exam

    The detailed knowledge of the accurate ion-solid interaction is at the heart of many technological applications such as nuclear safety, applied material science, medical physics and fusion and fission applications. Its accurate evaluation poses an enormous challenge due to the need of incorporating electronic structure, bound states, size effects, basis sets, and the quantum classical aspects of the problem. Most recent approaches relying on the fitting to experimental data or phenomenological model, fail to describe the ion-solid interaction properly (see [S. N. Markin, D. Primetzhofer, M. Spitz, and P. Bauer, Phys. Rev. B 80 (2009)]) for slow ions. A general Time-Dependent Density Functional Theory (TDDFT) is used in this thesis to evaluate electron-dynamics easily. For the first time a unified theory is proposed to describe the ion-solid interaction accurately over several orders of magnitude in the ion velocities, unveiling different regimes that before were only partially seen by separate experiments and rarely by any level of existing theory. We identified an electronic stopping which in the band-regime produces a quantum friction that is nonlinear with a power-law with an exponent ˜1.5. At low velocity this nonlinear effect will provide a new impetus for experimental investigations and an improve microscopic models of electron-ion dissipative dynamics. Our study will potentially impact both the experimental and theoretical research in condensed matter. We have applied our developed theory to study stopping of H+ in Cu. The target Cu comprises complicated band structure and this system will help to understand radiation of matter, both in its experimental understanding and also in the modeling of the process, for example in the context of damped molecular dynamics for the simulation of radiation cascades. At this present stage in the field of ion-solid interactions and quantum dissipative dynamics, our findings remain very significant. The same techniques are

  1. Atomic physics in the quest for fusion energy and ITER

    NASA Astrophysics Data System (ADS)

    Skinner, Charles H.

    2009-05-01

    The urgent quest for new energy sources has led developed countries, representing over half of the world population, to collaborate on demonstrating the scientific and technological feasibility of magnetic fusion through the construction and operation of the international thermonuclear experimental reactor (ITER). Data on high-Z ions will be important in this quest. Tungsten plasma facing components have the necessary low erosion rates and low tritium retention but the high radiative efficiency of tungsten ions leads to stringent restrictions on the concentration of tungsten ions in the burning plasma. The influx of tungsten to the burning plasma will need to be diagnosed, understood and stringently controlled. Expanded knowledge of the atomic physics of neutral and ionized tungsten will be important to monitor impurity influxes and derive tungsten concentrations. Also, inert gases such as argon and xenon will be used to dissipate the heat flux flowing to the divertor. This paper will summarize the spectroscopic diagnostics planned for ITER and outline areas where additional data are needed.

  2. Difference-frequency combs in cold atom physics

    NASA Astrophysics Data System (ADS)

    Kliese, Russell; Hoghooghi, Nazanin; Puppe, Thomas; Rohde, Felix; Sell, Alexander; Zach, Armin; Leisching, Patrick; Kaenders, Wilhelm; Keegan, Niamh C.; Bounds, Alistair D.; Bridge, Elizabeth M.; Leonard, Jack; Adams, Charles S.; Cornish, Simon L.; Jones, Matthew P. A.

    2016-12-01

    Optical frequency combs provide the clockwork to relate optical frequencies to radio frequencies. Hence, combs allow optical frequencies to be measured with respect to a radio frequency where the accuracy is limited only by the reference signal. In order to provide a stable link between the radio and optical frequencies, the two parameters of the frequency comb must be fixed: the carrier envelope offset frequency, f ceo, and the pulse repetition-rate, f rep. We have developed the first optical frequency comb based on difference frequency generation (DFG) that eliminates f ceo by design — specifically tailored for applications in cold atom physics. An f ceo-free spectrum at 1550 nm is generated from a super continuum spanning more than an optical octave. Established amplification and frequency conversion techniques based on reliable telecom fibre technology allow the generation of multiple wavelength outputs. The DFG comb is a convenient tool to both stabilise laser sources and accurately measure optical frequencies in Rydberg experiments and more generally in quantum optics. In this paper we discuss the frequency comb design, characterization, and optical frequency measurement of Strontium Rydberg states. The DFG technique allows for a compact and robust, passively f ceo stable frequency comb significantly improving reliability in practical applications.

  3. Multiple ionization and capture in relativistic heavy-ion atom collisions

    SciTech Connect

    Meyerhof, W.E.; Anholt, R.; Xu, Xiang-Yuan; Gould, H.; Feinberg, B.; McDonald, R.J.; Wegner, H.E.; Thieberger, P.

    1987-02-01

    We show that in relativistic heavy-ion collisions the independent electron model can be used to predict cross sections for multiple inner-shell ionization and capture in a single collision. Charge distributions of 82- to 200-MeV/amu Xe and 105- to 955-MeV/amu U ion beams emerging from thin solid targets were used to obtain single- and multiple-electron stripping and capture cross sections. The probabilities of stripping electrons from the K, L, or M shells were calculated using the semiclassical approximation and Dirac hydrogenic wavefunctions. For capture, a simplified model for electron capture was uded. The data generally agree with theory.

  4. Interactions and low-energy collisions between an alkali ion and an alkali atom of a different nucleus

    NASA Astrophysics Data System (ADS)

    Rakshit, Arpita; Ghanmi, Chedli; Berriche, Hamid; Deb, Bimalendu

    2016-05-01

    We study theoretically interaction potentials and low-energy collisions between different alkali atoms and alkali ions. Specifically, we consider systems such as X + {{{Y}}}+, where X({{{Y}}}+) is either Li(Cs+) or Cs(Li+), Na(Cs+) or Cs(Na+) and Li(Rb+) or Rb(Li+). We calculate the molecular potentials of the ground and first two excited states of these three systems using a pseudopotential method and compare our results with those obtained by others. We derive ground-state scattering wave functions and analyze the cold collisional properties of these systems for a wide range of energies. We find that, in order to get convergent results for the total scattering cross sections for energies of the order 1 K, one needs to take into account at least 60 partial waves. The low-energy scattering properties calculated in this paper may serve as a precursor for experimental exploration of quantum collisions between an alkali atom and an alkali ion of a different nucleus.

  5. Excitation, ionization, and electron capture cross sections for collisions of Li{sup 3+} with ground state and excited hydrogen atoms

    SciTech Connect

    Murakami, I. Yan, J.; Sato, H.; Kimura, M.; Janev, R.K.; Kato, T.

    2008-03-15

    Using the available experimental and theoretical data, as well as the established cross section scaling relationships, a comprehensive cross section database for excitation, ionization and electron capture in collisions of Li{sup 3+} ions with ground state and excited hydrogen atoms has been generated. The critically assessed cross sections are represented by analytic fit functions that have the correct asymptotic behavior both at low and high collision energies. The derived cross sections are also presented in graphical form.

  6. Collisions of electrons with hydrogen atoms I. Package outline and high energy code

    NASA Astrophysics Data System (ADS)

    Benda, Jakub; Houfek, Karel

    2014-11-01

    Being motivated by the applied researchers’ persisting need for accurate scattering data for the collisions of electrons with hydrogen atoms, we developed a computer package-Hex-that is designed to provide trustworthy results for all basic discrete and continuous processes within non-relativistic framework. The package consists of several computational modules that implement different methods, valid for specific energy regimes. Results of the modules are kept in a common database in the unified form of low-level scattering data (partial-wave T-matrices) and accessed by an interface program which is able to produce various derived quantities like e.g. differential and integral cross sections. This article is the first one of a series of articles that are concerned with the implementation and testing of the modules. Here we give an overview of their structure and present (a) the command-line interface program hex-db that can be also easily compiled into a derived code or used as a backend for a web-page form and (b) simple illustrative module specialized for high energies, hex-dwba, that implements distorted and plane wave Born approximation. Catalogue identifier: AETH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETH_v1_0.html Program obtainable from: CPC Program library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data etc.: 30367 No. of bytes in distributed program, including test data etc.: 232032 Distribution format: tar.gz Programming language: C++11 Operating system: Any system with a C++11 compiler (e.g. GCC 4.8.1; tested on OpenSUSE 13.1 and Windows 8). RAM: Test run 3 MiB. CPC Library Classification: 2.4 Electron scattering External libraries:GSL [49], FFTW3[52], SQLite3 [46]. All of the libraries are open-source and maintained. Nature of problem: Extraction of derived (observable) quantities from partial

  7. l- and n-changing collisions during interaction of a pulsed beam of Li Rydberg atoms with CO2

    NASA Astrophysics Data System (ADS)

    Dubreuil, B.; Harnafi, M.

    1989-07-01

    The pulsed Li atomic beam produced in our experiment is based on controlled transversely-excited-atmospheric CO2 laser-induced ablation of a Li metal target. The atomic beam is propagated in vacuum or in CO2 gas at low pressure. Atoms in the beam are probed by laser-induced fluorescence spectroscopy. This allows the determination of time-of-flight and velocity distributions. Li Rydberg states (n=5-13) are populated in the beam by two-step pulsed-laser excitation. The excited atoms interact with CO2 molecules. l- and n-changing cross sections are deduced from the time evolution of the resonant or collision-induced fluorescence following this selective excitation. l-changing cross sections of the order of 104 AṦ are measured; they increase with n as opposed to the plateau observed for Li* colliding with a diatomic molecule. This behavior is qualitatively well explained in the framework of the free-electron model. n-->n' changing processes with large cross sections (10-100 AṦ) are also observed even in the case of large electronic energy change (ΔEnn'>103 cm-1). These results can be interpreted in terms of resonant-electronic to vibrational energy transfers between Li Rydberg states and CO2 vibrational modes.

  8. Single ionization in highly charged ion-atom collisions at low to intermediate velocities

    NASA Astrophysics Data System (ADS)

    Abdallah, Mohammad Abdallah

    1998-11-01

    Single electron ejection from neutral targets (He and Ne) by the impact of low to highly charged ions (p, He+,/ Ne+,/ He2+,/ C6+,/ O8+, and Ne10+) at low to intermediate impact velocities is studied. A novel technique of electron momentum imaging is implemented. In this technique two-dimensional electron momentum distributions are produced in coincidence with recoil ions and projectile ions. In first generation experiments we studied the ejected electron momentum distributions without analyzing recoil ions momentum. This series of experiments revealed a charge-state dependence and velocity dependence that are contradictory to a dominant saddle point ionization mechanism at intermediate velocities. It showed a possibility of an agreement with a saddle centered distributions for low charge states at low collision velocities. To pursue the problem in more detail, we developed a second generation spectrometer which allowed us to fully determine the recoil ions momentum. This allowed us to determine the collision plane, energy loss (Q-value), and impact parameter for every collision that resulted in a single (target) electron ejection. This series of experiments revealed for the first time very marked structure in electron spectra that were impossible to observe in other experiments. These structures indicate the quasi-molecular nature of the collision process even at velocities comparable to the electron 'classical' orbital velocity. For the collisions of p, He+, and He2+ with He, a π-orbital shape of the electron momentum distribution is observed. This indicates the importance of the rotational coupling 2p/sigma/to2p/pi in the initial promotion of the ground state electron. This is followed by further promotions to the continuum. This agrees with the 'classical' description implied by the saddle-point ionization mechanism picture.

  9. Deactivation of krypton atoms in the metastable 5s({sup 3}P{sub 2}) state in collisions with krypton and argon atoms

    SciTech Connect

    Zayarnyi, D A; L'dov, A Yu; Kholin, I V

    2009-09-30

    The collision deactivation of the metastable 5s[3/2]{sub 2}{sup o}({sup 3}P{sub 2}) state of krypton atoms is studied by the absorption probe method in electron-beam-excited high-pressure Ar-Kr mixtures with a low krypton content. The rate constants of plasma-chemical reactions Kr* + Kr + Ar {yields} Kr{sub 2}* + Ar [(4.1{+-}0.4)x10{sup -33} cm{sup 6} s{sup -1}] and Kr* + 2Ar {yields} ArKr* + Ar (less than 10{sup -35} cm{sup 6} s{sup -1}) are measured for the first time and the rate constant of the reaction Kr* + Ar {yields} products + Ar [(3.8{+-}0.4)x10{sup -15} cm{sup 3} s{sup -1}] is refined. (active media)

  10. Collisions of sodium atoms with liquid glycerol: insights into solvation and ionization.

    PubMed

    Wiens, Justin P; Nathanson, Gilbert M; Alexander, William A; Minton, Timothy K; Lakshmi, Sankaran; Schatz, George C

    2014-02-26

    The reactive uptake and ionization of sodium atoms in glycerol were investigated by gas-liquid scattering experiments and ab initio molecular dynamics (AIMD) simulations. A nearly effusive beam of Na atoms at 670 K was directed at liquid glycerol in vacuum, and the scattered Na atoms were detected by a rotatable mass spectrometer. The Na velocity and angular distributions imply that all impinging Na atoms that thermally equilibrate on the surface remain behind, likely ionizing to e(-) and Na(+). The reactive uptake of Na atoms into glycerol was determined to be greater than 75%. Complementary AIMD simulations of Na striking a 17-molecule glycerol cluster indicate that the glycerol hydroxyl groups reorient around the Na atom as it makes contact with the cluster and begins to ionize. Although complete ionization did not occur during the 10 ps simulation, distinct correlations among the extent of ionization, separation between Na(+) and e(-), solvent coordination, and binding energies of the Na atom and electron were observed. The combination of experiments and simulations indicates that Na-atom deposition provides a low-energy pathway for generating solvated electrons in the near-interfacial region of protic liquids.

  11. Electron-Electron Interaction in Ion-Atom Collisions Studied by Projectile State-Resolved Auger Electron Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Lee, Do-Hyung

    1990-01-01

    This dissertation addresses the problem of dynamic electron-electron interactions in fast ion-atom collisions using projectile Auger electron spectroscopy. The study was carried out by measuring high-resolution projectile KLL Auger electron spectra as a function of projectile energy for the various collision systems of 0.25-2 MeV/u O^{q+} and F^ {q+} incident on H_2 and He targets. The electrons were detected in the beam direction, where the kinematic broadening is minimized. A zero-degree tandem electron spectrometer system was developed and showed the versatility of zero-degree measurements of collisionally-produced atomic states. The zero-degree binary encounter electrons (BEe), quasifree target electrons ionized by the projectiles in head-on collisions, were observed as a strong background in the KLL Auger electron spectrum. They were studied by treating the target ionization as 180^circ Rutherford elastic scattering in the projectile frame, and resulted in a validity test of the impulse approximation (IA) and a way to determine the spectrometer efficiency. An anomalous q-dependence, in which the zero-degree BEe yields increase with decreasing projectile charge state (q), was observed. State-resolved KLL Auger cross sections were determined by using the BEe normalization and thus the cross sections of the electron -electron interactions such as resonant transfer-excitation (RTE), electron-electron excitation (eeE), and electron -electron ionization (eeI) were determined. Projectile 2l capture with 1s to 2p excitation by the captured target electron was observed as an RTE process with Li-like and He-like projectiles and the measured RTEA (RTE followed by Auger decay) cross sections showed good agreement with an RTE-IA treatment and RTE alignment theory. Projectile 1s to 2p excitation by a target electron was observed an an eeE process with Li-like projectiles. Projectile 1s ionization by a target electron was observed as an eeI process with Be-like projectiles

  12. Time-Dependent Lattice Methods for Ion-Atom Collisions in Cartesian and Cylindrical Coordinate Systems

    SciTech Connect

    Pindzola, Michael S; Schultz, David Robert

    2008-01-01

    Time-dependent lattice methods in both Cartesian and cylindrical coordinates are applied to calculate excitation cross sections for p+H collisions at 40 keV incident energy. The time-dependent Schroedinger equation is solved using a previously formulated Cartesian coordinate single-channel method on a full 3D lattice and a newly formulated cylindrical coordinate multichannel method on a set of coupled 2D lattices. Cartesian coordinate single-channel and cylindrical coordinate five-channel calculations are found to be in reasonable agreement for excitation cross sections from the 1s ground state to the 2s, 2p, 3s, 3p, and 3d excited states. For extension of the time-dependent lattice method to handle the two electron dynamics found in p+He collisions, the cylindrical coordinate multichannel method appears promising due to the reduced dimensionality of its lattice.

  13. Three-body recombination in cold helium-helium-alkali-metal-atom collisions

    SciTech Connect

    Suno, Hiroya; Esry, B. D.

    2009-12-15

    Three-body recombination in helium-helium-alkali-metal collisions at cold temperatures is studied using the adiabatic hyperspherical representation. The rates for the three-body recombination processes {sup 4}He+{sup 4}He+X->{sup 4}He+{sup 4}HeX and {sup 4}He+{sup 4}He+X->{sup 4}He{sub 2}+X, with X={sup 7}Li, {sup 23}Na, {sup 39}K, {sup 85}Rb, and {sup 133}Cs, are calculated at nonzero collision energies by including not only zero total angular momentum, J=0, states but also J>0 states. The three-body recombination rates show a relatively weak dependence on the alkali-metal species, differing from each other only by about one order of magnitude, except for the {sup 4}He-{sup 4}He-{sup 23}Na system.

  14. Ultracold atomic collisions in tight harmonic traps: Quantum-defect model and application to metastable helium atoms

    SciTech Connect

    Peach, Gillian; Whittingham, Ian B.; Beams, Timothy J.

    2004-09-01

    We analyze a system of two colliding ultracold atoms under strong harmonic confinement from the viewpoint of quantum defect theory and formulate a generalized self-consistent method for determining the allowed energies. We also present two highly efficient computational methods for determining the bound state energies and eigenfunctions of such systems. The perturbed harmonic oscillator problem is characterized by a long asymptotic region beyond the effective range of the interatomic potential. The first method, which is based on quantum defect theory and is an adaptation of a technique developed by one of the authors (G.P.) for highly excited states in a modified Coulomb potential, is very efficient for integrating through this outer region. The second method is a direct numerical solution of the radial Schroedinger equation using a discrete variable representation of the kinetic energy operator and a scaled radial coordinate grid. The methods are applied to the case of trapped spin-polarized metastable helium atoms. The calculated eigenvalues agree very closely for the two methods, and with the eigenvalues computed using the generalized self-consistent method.

  15. Termolecular Associations of Ions in Gases, Recombination and Electron-Atom Collisions

    DTIC Science & Technology

    1989-09-30

    necessary and identify by block number) FIELD GROUP SUB-GROUP Recombination, Master Equation, Variational Principle, N/A N/A N/A Diffusional Method ...Bottleneck Method , Strong-Collision, Coupled.Nearest-Neighbor, Radiative, Dissociative 19. ABSTRACT (Continue on reverse if necessary and identify by block...as papers, with reprints sent to’AFOSR at various times during the period. The exact Master Equation Method , a Variational Principle discovered during

  16. Population transfer collisions involving nD Rydberg atoms in a CO2 optical dipole trap

    NASA Astrophysics Data System (ADS)

    Kondo, Jorge M.; Goncalves, Luis F.; Tallant, Jonathan E.; Marcassa, Luis G.

    2014-05-01

    There has been an increasing interest in cold Rydberg atoms over the last several years. The primary reason for this attention is that interactions between Rydberg atoms are strong and lead to many interesting and useful phenomena, which require high atomic density samples. In this work, we have loaded Rb atoms into a CO2 optical dipole trap. After the loading, we turn off the dipole trap and excite the Rydberg state using a combination of two cw laser beams at 780 nm and 480 nm respectively. Finally, the Rydberg atoms are detected using pulsed field ionization technique. By analyzing the electrons signal, we can study the population transfer from the nD state to the (n + 2)P as a function of the atomic density for 37 <= n <= 45. As the atomic density increases, the excitation of the nD state saturates, suggesting the occurrence of dipole blockade. Nevertheless, the (n + 2)P is quadratically proportional to the nD population. We have also investigated the role of a dc electrical field in such process. This work was supported by Fapesp and INCT-IQ.

  17. Atom Skimmers and Atom Lasers Utilizing Them

    NASA Technical Reports Server (NTRS)

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  18. Ionization and excitation in collisions between antiprotons and H(1s) atoms studied with Sturmian bases

    SciTech Connect

    Winter, Thomas G.

    2011-02-15

    Coupled two-center as well as one-center Sturmian cross sections have been determined for ionization and excitation in p-bar-H(1s) collisions at p-bar energies from 1 to 16 000 keV, following the author's recent work for p-H(1s) collisions [Phys. Rev. A 80, 032701 (2009)]. Basis convergence is studied in detail. Results for ionization and excitation are compared to other coupled-state results and to numerical results, as well as limited experimental results for ionization only. Except for the large, two-center coupled-Gaussian-pseudostate calculation of Toshima for ionization only [Phys. Rev. A 64, 024701 (2001)], previous calculations employed one-center bases, including a one-center Sturmian calculation by Igarashi et al. [Phys. Rev. A 61, 062712 (2000)]. A strong contrast with p-H collisions is confirmed at intermediate energies, while at high energies the extent of agreement is revealed between coupled-state results for the two collisional systems, as well as with first Born results.

  19. Turbulence and atomic physics in magnetically confined plasmas

    NASA Astrophysics Data System (ADS)

    Marandet, Y.; Bufferand, H.; Ciraolo, G.; Nace, N.; Serre, E.; Tamain, P.; Valentinuzzi, M.

    2017-03-01

    An overview of issues related to the interplay between atomic process and turbulence in the peripheral regions of magnetically confined fusion devices is presented. Both atomic processes and turbulence play key roles for fusion, but have most of the time been treated separately. The effects of fluctuations on the time averaged ionization balance, on the transport of neutral particles (atoms and molecules) are discussed, using stochastic models to generate fluctuations with statistically relevant properties. Then applications to optical diagnostics of turbulence, namely gas puff imaging and beam emission spectroscopy are discussed.

  20. An electrostatic storage ring for atomic and molecular physics, at KACST - a status report

    NASA Astrophysics Data System (ADS)

    El Ghazaly, Mohamed O. A.

    2015-01-01

    An electrostatic storage ring has been designed following the pioneering storage ring ELISA [1], and it is currently being built as a new core laboratory for atomic and molecular collisions at the King Abdulaziz City for Science and Technology (KACST), in Riyadh, Saudi Arabia. In this paper, the design of the electrostatic storage ring together with an outline on the status of the construction are given.

  1. Ultimate statistical physics: fluorescence of a single atom

    NASA Astrophysics Data System (ADS)

    Pomeau, Yves; Le Berre, Martine; Ginibre, Jean

    2016-10-01

    We discuss the statistics of emission of photons by a single atom or ion illuminated by a laser beam at the frequency of quasi-resonance between two energy levels, a situation that corresponds to real experiments. We extend this to the case of two laser beams resonant with the energy differences between two excited levels and the ground state (three level atom in V-configuration). We use a novel approach to this type of problem by considering a Kolmogorov equation for the probability distribution of the atomic state, which takes into account first the deterministic evolution of this state under the effect of the incoming laser beam and second the random emission of photons during the spontaneous decay of the excited state(s) to the ground state. This approach yields solvable equations in the two level atom case. For the three level atom case we set the problem and clearly define its frame. The results obtained are valid in both opposite limits of rare and frequent spontaneous decay, compared to the period of the optical Rabi oscillations due to the interaction between resonant excitation and atomic levels. Our analysis gives access to various statistical properties of the fluorescence light, including one showing that its fluctuations in time are not invariants under time reversal. This result makes evident the fundamentally irreversible character of quantum measurements, represented here by the emission of photons of fluorescence.

  2. Strong isotope effects on the charge transfer in slow collisions of He2+ with atomic hydrogen, deuterium, and tritium.

    PubMed

    Stolterfoht, N; Cabrera-Trujillo, R; Ohrn, Y; Deumens, E; Hoekstra, R; Sabin, J R

    2007-09-07

    Probabilities and cross sections for charge transfer by He2+ impact on atomic hydrogen (H), deuterium (D), and tritium (T) at low collision energies are calculated. The results are obtained using an ab initio theory, which solves the time-dependent Schrödinger equation. For the H target, excellent agreement is achieved between the present and previous results. Differences by orders of magnitude are observed between the cross sections for H, D, and T. A method is introduced to separate the contributions of charge-transfer mechanisms due to radial and rotational coupling. The large differences observed for H, D, and T are attributed to isotope effects in the rotational coupling mechanism.

  3. Kinetic-energy release distributions of fragment anions from collisions of potassium atoms with D-Ribose and tetrahydrofuran*

    NASA Astrophysics Data System (ADS)

    Rebelo, André; Cunha, Tiago; Mendes, Mónica; da Silva, Filipe Ferreira; García, Gustavo; Limão-Vieira, Paulo

    2016-06-01

    Kinetic-energy release distributions have been obtained from the width and shapes of the time-of-flight (TOF) negative ion mass peaks formed in collisions of fast potassium atoms with D-Ribose (DR) and tetrahydrofuran (THF) molecules. Recent dissociative ion-pair formation experiments yielding anion formation have shown that the dominant fragment from D-Ribose is OH- [D. Almeida, F. Ferreira da Silva, G. García, P. Limão-Vieira, J. Chem. Phys. 139, 114304 (2013)] whereas in the case of THF is O- [D. Almeida, F. Ferreira da Silva, S. Eden, G. García, P. Limão-Vieira, J. Phys. Chem. A 118, 690 (2014)]. The results for DR and THF show an energy distribution profile reminiscent of statistical degradation via vibrational excitation and partly due to direct transformation of the excess energy in translational energy.

  4. A Full-Relativistic B-Spline R-Matrix Method for Electron and Photon Collisions with Atoms and Ions

    NASA Astrophysics Data System (ADS)

    Zatsarinny, Oleg; Bartschat, Klaus

    2008-05-01

    We have extended our B-spline R-matrix (close-coupling) method [1] to fully account for relativistic effects in a Dirac-Coulomb formulation. Our numerical implementation of the close-coupling method enables us to construct term-dependent, non-orthogonal sets of one-electron orbitals for the bound and continuum electrons. This is a critical aspect for complex targets, where individually optimized one-electron orbitals can significantly reduce the size of the multi-configuration expansions needed for an accurate target description. Furthermore, core-valence correlation effets are treated fully ab initio, rather than through semi-empirical, and usually local, model potentials. The method will be described in detail and illustrated by comparing our theoretical predictions for e-Cs collisions with benchmark experiments for angle-integrated and angle-differential cross sections [2], various spin-dependent scattering asymmetries [3], and Stokes parameters measured in superelastic collisions with laser-excited atoms [4]. [1] O. Zatsarinny, Comp. Phys. Commun. 174, 273 (2006). [2] W. Gehenn and E. Reichert, J. Phys. B 10, 3105 (1977). [3] G. Baum et al., Phys. Rev. A 66, 022705 (2002) and 70, 012707 (2004). [4] D.S. Slaughter et al., Phys. Rev. A 75, 062717 (2007).

  5. A Fully Relativistic B-Spline R-Matrix Method for Electron and Photon Collisions with Atoms and Ions

    NASA Astrophysics Data System (ADS)

    Zatsarinny, Oleg; Bartschat, Klaus

    2008-10-01

    We have extended our B-spline R-matrix (close-coupling) method [1] to fully account for relativistic effects in a Dirac-Coulomb formulation. Our numerical implementation of the close-coupling method enables us to construct term-dependent, non-orthogonal sets of one-electron orbitals for the bound and continuum electrons. This is a critical aspect for complex targets, where individually optimized one-electron orbitals can significantly reduce the size of the multi-configuration expansions needed for an accurate target description. Core-valence correlation effets are treated fully ab initio, rather than through semi-empirical model potentials. The method is described in detail and will be illustrated by comparing our theoretical predictions for e-Cs collisions [2] with benchmark experiments for angle-integrated and angle-differential cross sections [3], various spin-dependent scattering asymmetries [4], and Stokes parameters measured in superelastic collisions with laser-excited atoms [5]. [1] O. Zatsarinny, Comp. Phys. Commun. 174, 273 (2006). [2] O. Zatsarinny and K. Bartschat, Phys. Rev. A 77, 062701 (2008). [3] W. Gehenn and E. Reichert, J. Phys. B 10, 3105 (1977). [4] G. Baum et al., Phys. Rev. A 66, 022705 (2002) and 70, 012707 (2004). [5] D.S. Slaughter et al., Phys. Rev. A 75, 062717 (2007).

  6. Electron Attachment in Low-Energy Electron Elastic Collisions with Au and Pt Atoms: Identification of Excited Anions

    NASA Astrophysics Data System (ADS)

    Msezane, A. Z.; Eure, A.; Felfli, Z.; Sokolovski, D.

    2009-11-01

    The recent Regge-pole methodology has been benchmarked [1] on the accurately measured binding energies of the excited Ge= and Sn= anions [2] through the binding energies (BEs) extracted from the Regge-pole calculated elastic total cross sections (TCSs). Here the methodology is applied together with a Thomas-Fermi type potential that incorporates the vital core polarization interaction to investigate the possibility of forming excited Au= and Pt= anions in low-energy electron elastic collisions with Au and Pt atoms. From the positions of the characteristic extremely narrow resonances in the total cross sections, we extract the binding energies of the excited Au= and Pt= anions formed as Regge resonances during the collisions. The angular life of the complexes thus formed is used to differentiate the stable excited bound states of the anions from the shape resonances [3]. The BEs for the excited Au= and Pt= anions are found to be 0.475eVand 0.543eV, respectively, challenging both theory and experiment to verify. [1] A. Msezane et al, Phys. Rev. A, Submitted (2009) [2] M. Scheer et al, Phys. Rev. A 58, 2844 (1998) [3] Z. Felfli et al, Phys. Rev. A 79, 012714 (2009)

  7. Numerical study of charge transfer processes in collisions of Be^4+ and He^2+ with atomic hydrogen

    NASA Astrophysics Data System (ADS)

    Minami, Tatsuya; Pindzola, Michael S.; Lee, Teck-Gee

    2005-05-01

    We have calculated state-selective charge-transfer cross sections in collisions of Be^(4+ with H(1s) and of He^2+ with H(1s). We have used the lattice time-dependent Schr"odinger equation (LTDSE) approach, the atomic orbital coupled channel (AOCC) method, and the classical trajectory Monte Carlo (CTMC) method. The calculations are performed with impact energy ranging between 1keV/u and 1MeV/u. With a well chosen basis-function set, we have found that AOCC gives good agreement with LTDSE. Also, with regard to Wigner's n-3 law, we have found that CTMC gives good extrapolations to the cross sections calculated by LTDSE and AOCC toward high n levels such as for those greater than 6. Thus, in our presentation, we will propose theoretical values of the total charge-transfer cross sections for these collision systems based on a combination of the most reliable results of the various method. This research used resources of the Center for Computational Sciences at Oak Ridge National Laboratory, which is supported by the Office of Science of the Department of Energy under Contract DE-AC05-00OR22725, and also of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

  8. Physics and the New Games -- or Pretend You're an Atom.

    ERIC Educational Resources Information Center

    Edge, Ronald D.

    1982-01-01

    Describes several games in which physics principles are demonstrated using students. These include Pirates Treasure Game (vectors), Three-Meter Dash (kinematics), Knee-Bend Game (energy and power), Wave Game, Reaction Kinematics, Statics-People Pyramids, and games demonstrating nuclear reactions, collisions, electrons in a wire, close packing, and…

  9. Regular and chaotic quantum dynamics in atom-diatom reactive collisions

    SciTech Connect

    Gevorkyan, A. S.; Nyman, G.

    2008-05-15

    A new microirreversible 3D theory of quantum multichannel scattering in the three-body system is developed. The quantum approach is constructed on the generating trajectory tubes which allow taking into account influence of classical nonintegrability of the dynamical quantum system. When the volume of classical chaos in phase space is larger than the quantum cell in the corresponding quantum system, quantum chaos is generated. The probability of quantum transitions is constructed for this case. The collinear collision of the Li + (FH) {sup {yields}}(LiF) + H system is used for numerical illustration of a system generating quantum (wave) chaos.

  10. Hot precursor reactions during the collisions of gas-phase oxygen atoms with deuterium chemisorbed on Pt(100)

    NASA Astrophysics Data System (ADS)

    Kan, Heywood H.; Shumbera, R. Bradley; Weaver, Jason F.

    2007-04-01

    We utilized direct rate measurements and temperature programmed desorption to investigate reactions that occur during the collisions of gaseous oxygen atoms with deuterium-covered Pt(100). We find that both D2O and D2 desorb promptly when an oxygen atom beam impinges upon D-covered Pt(100) held at surface temperatures ranging from 90to150K, and estimate effective cross sections of 12 and 1.8Å2, respectively, for the production of gaseous D2O and D2 at 90K. The yields of D2O and D2 that desorb at 90K are about 13% and 2%, respectively, of the initial D atom coverage, though most of the D2O product molecules (˜80%) thermalize to the surface rather than desorb at the surface temperatures studied. Increasing the surface temperature from 90to150K causes the D2O desorption rate to decay more quickly during O atom exposures to the surface and results in lower yields of gaseous D2O. We attribute the production of D2O and D2 in these experiments to reactions involving intermediates that are not thermally accommodated to the surface, so-called hot precursors. The results are consistent with the production of hot D2O involving first the generation of hot OD groups from the reaction O*+D(a)→OD*, where the asterisk denotes a hot precursor, followed by the parallel pathways OD *+D(a)→D2O* and OD *+OD(a)→D2O*+O(a). The final reaction contributes significantly to hot D2O production only later in the reaction period when thermalized OD groups have accumulated on the surface, and it becomes less important at higher temperature due to depletion of the OD(a) concentration by thermally activated D2O production.

  11. Hot precursor reactions during the collisions of gas-phase oxygen atoms with deuterium chemisorbed on Pt(100).

    PubMed

    Kan, Heywood H; Shumbera, R Bradley; Weaver, Jason F

    2007-04-07

    We utilized direct rate measurements and temperature programmed desorption to investigate reactions that occur during the collisions of gaseous oxygen atoms with deuterium-covered Pt(100). We find that both D2O and D2 desorb promptly when an oxygen atom beam impinges upon D-covered Pt(100) held at surface temperatures ranging from 90 to 150 K, and estimate effective cross sections of 12 and 1.8 A2, respectively, for the production of gaseous D2O and D2 at 90 K. The yields of D2O and D2 that desorb at 90 K are about 13% and 2%, respectively, of the initial D atom coverage, though most of the D2O product molecules (approximately 80%) thermalize to the surface rather than desorb at the surface temperatures studied. Increasing the surface temperature from 90 to 150 K causes the D2O desorption rate to decay more quickly during O atom exposures to the surface and results in lower yields of gaseous D2O. We attribute the production of D2O and D2 in these experiments to reactions involving intermediates that are not thermally accommodated to the surface, so-called hot precursors. The results are consistent with the production of hot D2O involving first the generation of hot OD groups from the reaction O*+D(a)-->OD*, where the asterisk denotes a hot precursor, followed by the parallel pathways OD*+D(a)-->D2O* and OD*+OD(a)-->D2O*+O(a). The final reaction contributes significantly to hot D2O production only later in the reaction period when thermalized OD groups have accumulated on the surface, and it becomes less important at higher temperature due to depletion of the OD(a) concentration by thermally activated D2O production.

  12. Pre-Service Physics Teachers' Ideas on Size, Visibility and Structure of the Atom

    ERIC Educational Resources Information Center

    Unlu, Pervin

    2010-01-01

    Understanding the atom gives the opportunity to both understand and conceptually unify the various domains of science, such as physics, chemistry, biology, astronomy and geology. Among these disciplines, physics teachers are expected to be particularly well educated in this topic. It is important that pre-service physics teachers know what sort of…

  13. Atomic data on inelastic processes in low-energy beryllium-hydrogen collisions

    NASA Astrophysics Data System (ADS)

    Yakovleva, Svetlana A.; Voronov, Yaroslav V.; Belyaev, Andrey K.

    2016-08-01

    Aims: Inelastic processes in low-energy Be + H and Be+ + H- collisions are treated for the states from the ground and up to the ionic state with the aim to provide rate coefficients needed for non-local thermodynamic equilibrium (non-LTE) modeling of beryllium spectra in cool stellar atmospheres. Methods: The electronic molecular structure is determined by using a recently proposed model quantum approach that is based on an asymptotic method. Nonadiabatic nuclear dynamics is treated by means of multichannel formulas, based on the Landau-Zener model for nonadiabatic transition probabilities. Results: The cross sections and the rate coefficients for inelastic processes in Be + H and Be+ + H- collisions are calculated for all transitions between 13 low-lying covalent states plus the ionic state. It is shown that the highest rate coefficient values correspond to the mutual neutralization processes with the final states Be(2s3s 1S), Be(2s3p 1,3P), Be(2s3d 3D). These processes, as well as some of the excitation, de-excitation and ion-pair formation processes, are likely to be important for non-LTE modeling. Tables A.1-A.10 are also available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/593/A27

  14. Nonadiabatic couplings in low-energy collisions of hydrogen ground-state atoms

    SciTech Connect

    Wolniewicz, L.

    2003-10-01

    The effect of nonadiabatic couplings on low-energy s-wave scattering of two hydrogen atoms is investigated. Coupling matrix elements are computed in a wide range of internuclear distances. The resulting scattering equations are numerically unstable and therefore are integrated only approximately. Computations are performed for H, D, and T atoms. The phase shifts in the zero velocity limit are inversely proportional to the nuclear reduced mass {delta}{sub 0}{approx_equal}0.392/{mu}. This leads to infinite scattering lengths.

  15. The Light at the End of the Tunnel: Uncertainties in Atomic Physics, Bayesian Inference, and the Analysis of Solar and Stellar Observations

    NASA Astrophysics Data System (ADS)

    Warren, Harry

    2016-05-01

    We report on the efforts of a multidisciplinary International Space Science Institute team that is investigating the limits of our ability to infer the physical properties of solar and stellar atmospheres from remote sensing observations. As part of this project we have estimated the uncertainties in the collisional cross sections and radiative decay rates for Fe XIII and O VII and created 1000 realizations of the CHIANTI atomic database. These perturbed atomic data are then used to analyze solar observations from the EIS spectrometer on Hinode and stellar observations from the LETG on Chandra within a Bayesian framework. For the solar case we find that the systematic errors from the atomic physics dominate the statistical uncertainties from the observations. For many cases the uncertainties are about 10 times larger when variations in the atomic data are included. This indicates the need for very accurate atomic physics. Comparisons among recent Fe XIII calculations suggest that for some transitions the collision rates are currently known well enough to measure the electron density and emission measure to about 15%.

  16. Vibrationally resolved transitions in ion-molecule and atom-molecular ion slow collisions

    DOE Data Explorer

    The data tables and interactive graphs made available here contain theoretical integral cross sections for vibrational excitation and vibrationally resolved charge transfer from vibrationally excited states of H2 and H2+ with protons and hydrogen atoms, respectively. [From http://www-cfadc.phy.ornl.gov/h2mol/home.html] (Specialized Interface)

  17. Design of a versatile pressure control system for gas targets in ion-atom collision studies

    NASA Astrophysics Data System (ADS)

    Fuelling, S.; Bruch, R.

    1993-06-01

    In this work, a unique gas target pressure control system is described which has been developed to measure state selective absolute EUV cross sections subsequent to electron and ion impact on gaseous targets. This system can be used in any type of gas phase experiment using positively or negatively charged and neutral particle beams interacting with atomic and molecular targets.

  18. Inelastic processes in atomic, molecular and chemical physics (in honour of Andrey K. Belyaev)

    NASA Astrophysics Data System (ADS)

    Barklem, Paul S.; Tscherbul, Timur V.

    2015-11-01

    This Special Issue is dedicated to Professor Andrey K. Belyaev, on the occasion of his 60th birthday and in celebration of his productive career in theoretical atomic, molecular, and chemical physics. It brings together 12 research studies of Inelastic Processes in Atomic, Molecular and Chemical Physics, a research area where Andrey himself made significant contributions. Inelastic processes are central to many different areas of physics, including atmospheric physics, astrophysics, and plasma physics to name a few, as well as in related technological applications such as lasers and fusion reactors. Quantitative understanding of the mechanisms of inelastic processes in atoms and molecules is therefore a problem of fundamental importance in physics, astrophysics, and chemistry. It is precisely this challenging problem that Andrey's research addresses using a broad arsenal of theoretical tools and techniques.

  19. Time-dependence ion charge state distributions of vacuum arcs: An interpretation involving atoms and charge exchange collisions

    SciTech Connect

    Anders, Andre

    2004-08-27

    Experimentally observed charge state distributions are known to be higher at the beginning of each arc discharge. Up to know, this has been attributed to cathode surface effects in terms of changes of temperature, chemical composition and spot mode. Here it is shown that the initial decay of charge states of cathodic arc plasmas may at least in part due to charge exchange collisions of ions with neutrals that gradually fill the discharge volume. Sources of neutrals may include evaporated atoms from macroparticles and still-hot craters of previously active arc spots. More importantly, atoms are also produced by energetic condensation of the cathodic arc plasma. Self-sputtering is significant when ions impact with near-normal angle of incidence, and ions have low sticking probability when impacting at oblique angle of incidence. Estimates show that the characteristic time for filling the near-cathode discharge volume agrees well with the charge state decay time, and the likelihood of charge exchange is reasonably large to be taken into account.

  20. Upper Secondary Students' Understanding of the Basic Physical Interactions in Analogous Atomic and Solar Systems

    ERIC Educational Resources Information Center

    Taber, Keith S.

    2013-01-01

    Comparing the atom to a "tiny solar system" is a common teaching analogy, and the extent to which learners saw the systems as analogous was investigated. English upper secondary students were asked parallel questions about the physical interactions between the components of a simple atomic system and a simple solar system to investigate…

  1. Request for Support for the Conference on Super Intense Laser Atom Physics

    SciTech Connect

    Todd Ditmire

    2004-10-21

    The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions.

  2. Single electron transfer in He+-He+ collision and production of helium atom

    NASA Astrophysics Data System (ADS)

    Azizan, Shima; Fathi, Reza; Shojaei, Farideh

    2017-02-01

    The four body Born distorted wave (BDW-4B) approximation with correct boundary condition is used for single electron transfer in He+-He+ collision. The post and prior total cross sections are obtained in the energy range 10-1000 keV/amu and the post-prior discrepancy is estimated. The sensitivity of the results with respect to the choice of the final helium-like ground state wave function is evaluated through two different wave functions. The importance of the dynamic electron correlations is tested as a function of impact energy. Additional experimental data at higher impact energies is needed for a better assessment of the validity of the present theory.

  3. Depolarized light scattering studies of the collision induced polarizability anisotropy of atoms and spherical top molecules

    NASA Astrophysics Data System (ADS)

    Dunmur, D. A.; Manterfield, M. R.; Robinson, D. J.

    New measurements are reported of the density dependent depolarization ratio for argon, krypton, xenon, methane and sulphur hexafluoride, and the results are analysed to provide values for the second and third depolarization virial coefficients. The relationships between the second depolarization virial coefficient, the zeroth moment of the two-body Rayleigh spectrum and the second Kerr virial coefficient are considered, and it is shown that they now provide consistent results for the collision-induced pair polarizability anisotropy. Former inconsistencies are attributed to insufficient allowance for the effects of three-body interactions. Calculations of the second and third depolarization virial coefficients based on the DID model and using the Maitland-Smith potential are in excellent agreement with the experimental results for argon, krypton and xenon.

  4. Quantum fluid density functional theory of time-dependent phenomena: Ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Deb, B. M.; Chattaraj, P. K.

    1988-07-01

    Using a recently proposed kinetic energy density functional and an amalgamation of density functional theory with quantum fluid dynamics, a time-dependent Kohn-Sham-type equation in three-dimensional space, which is a new non-linear Schrödinger equation, has been derived. The equation is also derived through the stochastic interpretation of quantum mechanics. A molecular "thermodynamic" viewpoint is suggested in terms of space-time-dependent quantities. Numerical solution of the above equation yields the time-dependent charge density, current density, effective potential and chemical potential. Perspective plots of these quantities for the proton-neon 25 keV head-on collision are presented.

  5. Cross sections for electron capture and excitation in collisions of Li{sup q+} (q=1, 2, 3) with atomic hydrogen

    SciTech Connect

    Liu, L.; Wang, J. G.; Li, X. Y.; Janev, R. K.

    2014-06-15

    The two-center atomic orbital close-coupling method is employed to study electron capture and excitation reactions in collisions of Li{sup q+} (q = 1-3) ions with ground state atomic hydrogen in the ion energy range from 0.1 keV/u to 300 keV/u, where u is the atomic mass unit. The interaction of the active electron with the projectile ions (Li{sup +}, Li{sup 2+}) is represented by a model potential. Total and state-selective cross sections for charge transfer and excitation processes are calculated and compared with data from other sources when available.

  6. Research in atomic and applied physics using a 6-GeV synchrotron source

    SciTech Connect

    Jones, K.W.

    1985-12-01

    The Division of Atomic and Applied Physics in the Department of Applied Science at Brookhaven National Laboratory conducts a broad program of research using ion beams and synchrotron radiation for experiments in atomic physics and nuclear analytical techniques and applications. Many of the experiments would benefit greatly from the use of high energy, high intensity photon beams from a 6-GeV synchrotron source. A survey of some of the specific scientific possibilities is presented.

  7. Learning Pathways in High-School Level Quantum Atomic Physics.

    ERIC Educational Resources Information Center

    Niedderer, Hans; Petri, Juergen

    Investigations of changes in conceptions during physics instruction are the logical and necessary steps to follow successful international research on students' preinstructional conceptions. The theoretical perspective integrates currently available frameworks of cognition, cognitive states, and cognitive processes in physics. Particular emphasis…

  8. A Cold Atom Measurement of Charge Exchange Collisions between Trapped Yb^+ and Yb

    NASA Astrophysics Data System (ADS)

    Grier, Andrew; Cetina, Marko; Orucevic, Fedja; Vuletic, Vladan

    2008-05-01

    We measure the collisional cross-section and rate constant of the ^174Yb and ^172Yb^+ charge-transfer process. The neutral atoms are trapped in a magneto-optical trap (MOT) resonant with their 399 nm, ^1S0->^1P1 transition and are near the Doppler-limited temperature of 680 μK. The ions are confined in a planar Paul trap with a secular frequency of 39 kHz, Doppler cooled, and spatially overlapped with the neutral atoms. The collisional energy is varied from 4 meV to 100s of neV by varying the micromotion energy of the ions by displacement from the center of the Paul trap. We report the rate constant in comparison to that derived from the Langevin cross-section.

  9. Charge exchange transition probability for collisions between unlike ions and atoms within the adiabatic approximation

    NASA Technical Reports Server (NTRS)

    Xu, Y. J.; Khandelwal, G. S.; Wilson, John W.

    1989-01-01

    A simple formula for the transition probability for electron exchange between unlike ions and atoms is established within the adiabatic approximation by employing the Linear Combination of Atomic Orbitals (LCAO) method. The formula also involves an adiabatic parameter, introduced by Massey, and thus the difficulties arising from the internal energy defect and the adiabatic approximation are avoided. Specific reactions Li(+++) + H to Li(++) + H(+) and Be(4+) + H to Be(3+) + H(+) are considered as examples. The calculated capture cross section results of the present work are compared with the experimental data and with the calculation of other authors over the velocity range of 10(7) cm/sec to 10(8) cm/sec.

  10. Dynamics of carbon-hydrogen and carbon-methyl exchanges in the collision of 3P atomic carbon with propene

    NASA Astrophysics Data System (ADS)

    Lee, Shih-Huang; Chen, Wei-Kan; Chin, Chih-Hao; Huang, Wen-Jian

    2013-11-01

    We investigated the dynamics of the reaction of 3P atomic carbon with propene (C3H6) at reactant collision energy 3.8 kcal mol-1 in a crossed molecular-beam apparatus using synchrotron vacuum-ultraviolet ionization. Products C4H5, C4H4, C3H3, and CH3 were observed and attributed to exit channels C4H5 + H, C4H4 + 2H, and C3H3 + CH3; their translational-energy distributions and angular distributions were derived from the measurements of product time-of-flight spectra. Following the addition of a 3P carbon atom to the C=C bond of propene, cyclic complex c-H2C(C)CHCH3 undergoes two separate stereoisomerization mechanisms to form intermediates E- and Z-H2CCCHCH3. Both the isomers of H2CCCHCH3 in turns decompose to C4H5 + H and C3H3 + CH3. A portion of C4H5 that has enough internal energy further decomposes to C4H4 + H. The three exit channels C4H5 + H, C4H4 + 2H, and C3H3 + CH3 have average translational energy releases 13.5, 3.2, and 15.2 kcal mol-1, respectively, corresponding to fractions 0.26, 0.41, and 0.26 of available energy deposited to the translational degrees of freedom. The H-loss and 2H-loss channels have nearly isotropic angular distributions with a slight preference at the forward direction particularly for the 2H-loss channel. In contrast, the CH3-loss channel has a forward and backward peaked angular distribution with an enhancement at the forward direction. Comparisons with reactions of 3P carbon atoms with ethene, vinyl fluoride, and vinyl chloride are stated.

  11. Molecular collisions. 11: Semiclassical approximation to atom-symmetric top rotational excitation

    NASA Technical Reports Server (NTRS)

    Russell, D.; Curtiss, C. F.

    1973-01-01

    In a paper of this series a distorted wave approximation to the T matrix for atom-symmetric top scattering was developed which is correct to first order in the part of the interaction potential responsible for transitions in the component of rotational angular momentum along the symmetry axis of the top. A semiclassical expression for this T matrix is derived by assuming large values of orbital and rotational angular momentum quantum numbers.

  12. Analysis of In-Flight Collision Process During V-Type Firing Pattern in Surface Blasting Using Simple Physics

    NASA Astrophysics Data System (ADS)

    Chouhan, Lalit Singh; Raina, Avtar K.

    2015-10-01

    Blasting is a unit operation in Mine-Mill Fragmentation System (MMFS) and plays a vital role in mining cost. One of the goals of MMFS is to achieve optimum fragment size at minimal cost. Blast fragmentation optimization is known to result in better explosive energy utilization. Fragmentation depends on the rock, explosive and blast design variables. If burden, spacing and type of explosive used in a mine are kept constant, the firing sequence of blast-holes plays a vital role in rock fragmentation. To obtain smaller fragmentation size, mining professionals and relevant publications recommend V- or extended V-pattern of firing sequence. In doing so, it is assumed that the in-flight air collision breaks larger rock fragments into smaller ones, thus aiding further fragmentation. There is very little support to the phenomenon of breakage during in-flight collision of fragments during blasting in published literature. In order to assess the breakage of in-flight fragments due to collision, a mathematical simulation was carried over using basic principles of physics. The calculations revealed that the collision breakage is dependent on velocity of fragments, mass of fragments, the strength of the rock and the area of fragments over which collision takes place. For higher strength rocks, the in-flight collision breakage is very difficult to achieve. This leads to the conclusion that the concept demands an in-depth investigation and validation.

  13. Computational challenges in atomic, molecular and optical physics.

    PubMed

    Taylor, Kenneth T

    2002-06-15

    Six challenges are discussed. These are the laser-driven helium atom; the laser-driven hydrogen molecule and hydrogen molecular ion; electron scattering (with ionization) from one-electron atoms; the vibrational and rotational structure of molecules such as H(3)(+) and water at their dissociation limits; laser-heated clusters; and quantum degeneracy and Bose-Einstein condensation. The first four concern fundamental few-body systems where use of high-performance computing (HPC) is currently making possible accurate modelling from first principles. This leads to reliable predictions and support for laboratory experiment as well as true understanding of the dynamics. Important aspects of these challenges addressable only via a terascale facility are set out. Such a facility makes the last two challenges in the above list meaningfully accessible for the first time, and the scientific interest together with the prospective role for HPC in these is emphasized.

  14. Physics of the missing atoms: technetium and promethium

    SciTech Connect

    Aspden, H.

    1987-05-01

    Technetium (Z = 43) and promethium (Z = 61) are by far the least abundant of all atoms below the radioactive elements (Z = 84 onwards). Their scarcity confirms theoretical predictions emerging from a theory of the photon derived from synchronous lattice electrodynamics. This theory has given precise theoretical values for the fine-structure constant and the constant of gravitation G and is now shown in this paper to indicate resonant interactions between the vacuum lattice oscillations and technetium and promethium. In the case of promethium there is strong reason for believing that this atom can assume supergravitational or antigravitational properties, accounting for its scarcity. This paper not only adds support to the earlier theoretical work on the photon and gravitation, but suggests a research route that might lead to new technology based on controlled interactions with gravity fields.

  15. Quenching of the resonance 5s({sup 3}P{sub 1}) state of krypton atoms in collisions with krypton and helium atoms

    SciTech Connect

    Zayarnyi, D A; L'dov, A Yu; Kholin, I V

    2014-11-30

    The processes of collision quenching of the resonance 5s[3/2]{sub 1}{sup o}({sup 3}P{sub 1}) state of the krypton atom are studied by the absorption probe method in electron-beam-excited high-pressure He – Kr mixtures with a low content of krypton. The rate constants of plasmochemical reactions Kr* + Kr + He → Kr*{sub 2} + He [(4.21 ± 0.42) × 10{sup -33} cm{sup 6} s{sup -1}], Kr* + 2He → HeKr* + He [(4.5 ± 1.2) × 10{sup -36} cm{sup 6} s{sup -1}] and Kr* + He → products + He [(2.21 ± 0.22) × 10{sup -15} cm{sup 3} s{sup -1}] are measured for the first time. The rate constants of similar reactions are refined for krypton in the metastable 5s[3/2]{sub 2}{sup o} ({sup 3}P{sub 2}) state. (laser applications and other topics in quantum electronics)

  16. Theoretical Demonstration of the Feasibility of Observing Vortices in the Ejected Electron Spectrum in Bare-Ion Two-Electron-Atom Collisions

    SciTech Connect

    Ovchinnikov, S. Yu.; Macek, Joseph H; Schmidt, L. Ph.H; Schultz, David Robert

    2011-01-01

    Using a fully correlated, 4-dimensional lattice, time-dependent Schr dinger equation (LTDSE) model of the collisions of bare projectile ions with two-electron atoms (H+, He2+ + He), we demonstrate the existence vortices in the resulting spectrum of ejected electrons. Following the uncovering of these features in collisions involving only one electron (H+ + H) [Macek et al., Phys. Rev. Lett. 102, 143201 (2009)], this demonstration provides impetus for seeking these features in more readily feasible experimental conditions using a cold helium target and the reaction microscope technique.

  17. Hydrogen Atom Collision Processes in Cool Stellar Atmospheres: Effects on Spectral Line Strengths and Measured Chemical Abundances in Old Stars

    NASA Astrophysics Data System (ADS)

    Barklem, Paul S.

    2012-12-01

    The precise measurement of the chemical composition of stars is a fundamental problem relevant to many areas of astrophysics. State-of-the-art approaches attempt to unite accurate descriptions of microphysics, non-local thermodynamic equilibrium (non-LTE) line formation and 3D hydrodynamical model atmospheres. In this paper I review progress in understanding inelastic collisions of hydrogen atoms with other species and their influence on spectral line formation and derived abundances in stellar atmospheres. These collisions are a major source of uncertainty in non-LTE modelling of spectral lines and abundance determinations, especially for old, metal-poor stars, which are unique tracers of the early evolution of our galaxy. Full quantum scattering calculations of direct excitation processes X(nl) + H leftrightarrow X(n'l') + H and charge transfer processes X(nl) + H leftrightarrow X+ + H- have been done for Li, Na and Mg [1,2,3] based on detailed quantum chemical data, e.g. [4]. Rate coefficients have been calculated and applied to non-LTE modelling of spectral lines in stellar atmospheres [5,6,7,8,9]. In all cases we find that charge transfer processes from the first excited S-state are very important, and the processes affect measured abundances for Li, Na and Mg in some stars by as much as 60%. Effects vary with stellar parameters (e.g. temperature, luminosity, metal content) and so these processes are important not only for accurate absolute abundances, but also for relative abundances among dissimilar stars.

  18. Electronic quenching of OH A 2Σ+ induced by collisions with Kr atoms.

    PubMed

    Lehman, Julia H; Lester, Marsha I; Kłos, Jacek; Alexander, Millard H; Dagdigian, Paul J; Herráez-Aguilar, Diego; Aoiz, F Javier; Brouard, Mark; Chadwick, Helen; Perkins, Tom; Seamons, Scott A

    2013-12-19

    Electronic quenching of OH A (2)Σ(+) by Kr was investigated through experimental studies of the collision cross sections and the OH X (2)Π product state distribution. The quenching cross sections decrease with increasing rotational excitation in the excited OH A (2)Σ(+) electronic state. The OH X (2)Π products of quenching exhibit a significant degree of rotational excitation but minimal vibrational excitation. Complementary theoretical studies of the OH (A (2)Σ(+), X (2)Π) + Kr potential energy surfaces (PESs), nonadiabatic coupling, and quasiclassical trajectory calculations were carried out to elucidate the quenching dynamics. Accurate PESs for the two lowest diabatic states of A' symmetry were computed along with the angularly dependent coupling between them. Coupling in nearly linear HO-Kr configurations provides the mechanism for the observed electronic quenching. A deep attractive well on the OH A (2)Σ(+) + Kr PES facilitates access to this region of strong coupling. Surface-hopping quasiclassical trajectory calculations yielded quenching cross sections and a OH X (2)Π product rotational distribution in good accord with experimental observations.

  19. The Role of High-Energy Ion-Atom/Molecule Collisions in Radiotherapy

    NASA Astrophysics Data System (ADS)

    Belkić, Dževad

    2014-12-01

    The need for ions in radiotherapy stems from the most favorable localization of the largest energy deposition, precisely at the tumor site with small energy losses away from the target. Such a dose conformity to the target is due to heavy masses of ions that scatter predominantly in the forward direction and lose maximal energy mainly near the end of their path in the vicinity of the Bragg peak. The heavy masses of nuclei preclude noticeable multiple scattering of the primary ion beam. This occurrence is responsible for only about 30% of ion efficiency in killing tumor cells. However, ionization of targets by fast ions yields electrons that might be of sufficient energy to produce further radiation damage. These δ-electrons, alongside radicals produced by ion-water collisions, can accomplish the remaining 70% of tumor cell eradication. Electrons achieve this chiefly through multiple scattering due to their small mass. Therefore, energy depositions by both heavy (nuclei) and light (electrons) particles as well as highly reactive radicals need to be simultaneously transported in Monte Carlo simulations. This threefold transport of particles is yet to be developed for the existing Monte Carlo codes. Critical to accomplishing this key goal is the availability of accurate cross section databases. To this end, the leading continuum distorted wave methodologies are poised to play a pivotal role in predicting energy losses of ions in tissue as discussed in this work.

  20. Transfer of a weakly bound electron in collisions of Rydberg atoms with neutral particles. II. Ion-pair formation and resonant quenching of the Rb(nl) and Ne(nl) States by Ca, Sr, and Ba atoms

    SciTech Connect

    Narits, A. A.; Mironchuk, E. S.; Lebedev, V. S.

    2013-10-15

    Electron-transfer processes are studied in thermal collisions of Rydberg atoms with alkaline-earth Ca(4s{sup 2}), Sr(5s{sup 2}), and Ba(6s{sup 2}) atoms capable of forming negative ions with a weakly bound outermost p-electron. We consider the ion-pair formation and resonant quenching of highly excited atomic states caused by transitions between Rydberg covalent and ionic terms of a quasi-molecule produced in collisions of particles. The contributions of these reaction channels to the total depopulation cross section of Rydberg states of Rb(nl) and Ne(nl) atoms as functions of the principal quantum number n are compared for selectively excited nl-levels with l Much-Less-Than n and for states with large orbital quantum numbers l = n - 1, n - 2. It is shown that the contribution from resonant quenching dominates at small values of n, and the ion-pair formation process begins to dominate with increasing n. The values and positions of the maxima of cross sections for both processes strongly depend on the electron affinity of an alkaline-earth atom and on the orbital angular momentum l of a highly excited atom. It is shown that in the case of Rydberg atoms in states with large l {approx} n - 1, the rate constants of ion-pair formation and collisional quenching are considerably lower than those for nl-levels with l Much-Less-Than n.

  1. Quantum mechanical theory of a structured atom-diatom collision system - A + BC/1-Sigma/

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1977-01-01

    The problem of a 2-p state atom colliding with a singlet sigma state diatom, which involves multiple potential surfaces, is investigated. Within a diabatic representation for the electronic degrees of freedom (plus spin-orbit interaction), coupled scattering equations are derived in both space-fixed and body-fixed coordinate systems. Coefficients, analogous to Percival-Seaton coefficients, are obtained. Approximations to the exact equations, including angular momenta decoupling approximations, are discussed for both the space-fixed and body-fixed formalisms.

  2. The Physics of Spin-Polarized Atomic Vapors.

    DTIC Science & Technology

    1985-01-01

    formula (82) (Ref. II). shift methods. In this paper we present the basic theory of spin ex- lower third-body pressures. Essentially the same relaxa- change...polarization during the 129Xe relaxa- The voltages on the capacitors are tion transient the left side of R,, in Fig. 17 is essentially "FM F) at ground...exchange is described by non-linear rate equa- tions. The nonlinearity is essential if one is to account for the spin polarization of both atoms which are

  3. Application of Group Theory to Some Problems in Atomic Physics.

    NASA Astrophysics Data System (ADS)

    Suskin, Mark Albert

    This work comprises three problems, each of which lends itself to investigation via the theory of groups and group representations. The first problem is to complete a set of operators used in the fitting of atomic energy levels of atoms whose ground configuration is f ^ 3. The role of group theory in the labelling of these operators and in their construction is explained. Values of parameters associated with a subset of the operators are also calculated via their group labels. The second problem is to explain the term inversion that occurs between states of the configuration of two equivalent electrons and certain of the states of the half-filled shell. This leads to generalizations that make it possible to investigate correspondences between matrix elements of effective operators taken between states of other configurations besides the two mentioned. This is made possible through the notion of quasispin. The third problem is the construction of recoupling coefficients for groups other than SO(3). Questions of phase convention and Kronecker-product multiplicities are taken up. Several methods of calculation are given and their relative advantages discussed. Tables of values of the calculated 6-j symbols are provided.

  4. Nuclear physics (of the cell, not the atom)

    PubMed Central

    Pederson, Thoru; Marko, John F.

    2014-01-01

    The nucleus is physically distinct from the cytoplasm in ways that suggest new ideas and approaches for interrogating the operation of this organelle. Chemical bond formation and breakage underlie the lives of cells, but as this special issue of Molecular Biology of the Cell attests, the nonchemical aspects of cell nuclei present a new frontier to biologists and biophysicists. PMID:25368422

  5. Project Physics Teacher Guide 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Teaching procedures of Project Physics Unit 5 are presented to help teachers make effective use of learning materials. Unit contents are discussed in connection with teaching aid lists, multi-media schedules, schedule blocks, and resource charts. Brief summaries are made for transparencies, 16mm films, and reader articles. Included is information…

  6. Nuclear physics (of the cell, not the atom).

    PubMed

    Pederson, Thoru; Marko, John F

    2014-11-05

    The nucleus is physically distinct from the cytoplasm in ways that suggest new ideas and approaches for interrogating the operation of this organelle. Chemical bond formation and breakage underlie the lives of cells, but as this special issue of Molecular Biology of the Cell attests, the nonchemical aspects of cell nuclei present a new frontier to biologists and biophysicists.

  7. Formation rate for Rb 2 + molecular ions created in collisions of Rb Rydberg and ground-state atoms

    NASA Astrophysics Data System (ADS)

    Stanojevic, Jovica; Côté, Robin

    2016-05-01

    We calculate the formation rate of the molecular Rb2+ion in its various bound states produced in the associative ionization of a Rydberg and a ground-state atom. Before the formation takes place, the colliding atoms are accelerated by an attractive force between the collision partners. In this way the ground-state atom is first captured by the Rydberg electron and then guided towards the positive ion-core where a molecular ion is subsequently formed. As recently demonstrated, this process results in giant collisional cross sections for the molecular ion formation, with the cross sections essentially determined by the size of the Rydberg atom. For sufficient high principal quantum numbers and atomic densities, many ground-state atoms are already located inside the Rydberg atom and ready to participate in the associative ionization. The same process can occur between a Rydberg and a ground-state atom that form a long-range Rydberg molecule, possibly contributing to the shortening of the lifetimes of Rydberg atoms and molecules. Partial support from the US Army Research Office (ARO-MURI W911NF-14-1-0378), and from NSF (Grant No. PHY-1415560).

  8. Physical mechanisms for atomization of a jet spray

    SciTech Connect

    Bower, G.; Chang, S.K.; Corradini, M.L.; El-Beshbeeshy, M.; Martin, J.K.; Krueger, J.

    1988-01-01

    Because combustion in direct injection engines is strongly influenced by the details of the fuel spray in thes engines, the authors have begun a broad research effort of jet breakup experiments and modelling of these high pressure sprays. The main objective of this effort is to better understand fuel injection from the study of the spray-jet breakup process and the associated fuel-oxidant mixing. The focus of this paper is the development of specific models for atomization of the spray-jet. These models are then compared to each other and to preliminary data from the spray-jet breakup experiments. Initial results indicate that KIVA with this proposed spray model shows good agreement with low pressure data (69 MPa) but underestimates spray penetration for higher pressures (104 MPa).

  9. PREFACE: International Symposium on (e,2e), Double Photoionization and Related Topics & 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions

    NASA Astrophysics Data System (ADS)

    Martin, Nicholas L. S.; deHarak, Bruno A.

    2010-01-01

    From 30 July to 1 August 2009, over a hundred scientists from 18 countries attended the International Symposium on (e,2e), Double Photoionization and Related Topics and the 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions which were held at the W T Young Library of the University of Kentucky, USA. Both conferences were satellite meetings of the XXVI International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC) held in Kalamazoo, Michigan, USA, 21-28 July 2009. These symposia covered a broad range of experimental and theoretical topics involving excitation, ionization (single and multiple), and molecular fragmentation, of a wide range of targets by photons and charged particles (polarized and unpolarized). Atomic targets ranged from hydrogen to the heavy elements and ions, while molecular targets ranged from H2 to large molecules of biological interest. On the experimental front, cold target recoil ion momentum spectroscopy (COLTRIMS), also known as the Reaction Microscope because of the complete information it gives about a wide variety of reactions, is becoming commonplace and has greatly expanded the ability of researchers to perform previously inaccessible coincidence experiments. Meanwhile, more conventional spectrometers are also advancing and have been used for increasingly sophisticated and exacting measurements. On the theoretical front great progress has been made in the description of target states, and in the scattering calculations used to describe both simple and complex reactions. The international nature of collaborations between theorists and experimentalists is exemplified by, for example, the paper by Ren et al which has a total of 13 authors of whom the experimental group of six is from Heidelberg, Germany, one theoretical group is from Australia, with the remainder of the theoreticians coming from several different institutions in the United States. A total of 52 invited talks and

  10. Multiple ionization of neon atoms in collisions with bare and dressed ions: A mean-field description considering target response

    NASA Astrophysics Data System (ADS)

    Schenk, Gerald; Kirchner, Tom

    2015-05-01

    We investigate projectile-charge-state-differential electron removal from neon atoms by impact of He2+, Li3+, B2+, and C3+ ions at intermediate projectile energies (25 keV/u to 1 MeV/u ). The many-electron problem is described with an independent electron model in which active electrons at both collision centers are propagated in a common mean-field potential. Response to electron removal is taken into account in terms of a time-dependent screening potential, and a Slater-determinant-based method is used for the final-state analysis. Total cross sections for net recoil ion production, multiple ionization, and capture channels are mostly in good agreement with published experimental data. Results from equicharged bare and dressed ions are compared and the net recoil ion production cross section is broken down into contributions associated with different final projectile charge states in order to shed light on the role of the projectile electrons.

  11. Cold collisions of ground-state calcium atoms in a laser field: A theoretical study

    SciTech Connect

    Bussery-Honvault, Beatrice; Launay, Jean-Michel; Moszynski, Robert

    2003-09-01

    State-of-the-art ab initio techniques have been applied to compute the potential-energy curves for the ground X {sup 1}{sigma}{sub g}{sup +} and excited {sup 1}{pi}{sub g}(4s3d) states of the calcium dimer in the Born-Oppenheimer approximation. The weakly bound ground state was calculated by symmetry-adapted perturbation theory, while the strongly bound excited state was computed using a combination of the linear-response theory within the coupled-cluster singles and doubles framework for the core-valence electronic correlation and of the full configuration interaction for the valence-valence correlation. The ground-state potential has been corrected by considering the relativistic terms resulting from the first-order many-electron Breit theory, and the retardation corrections. The magnetic electronic transition dipole moment governing the {sup 1}{pi}{sub g}(leftarrow){sup 1}{sigma}{sub g}{sup +} transitions has been obtained as the first residue of the polarization propagator computed with the coupled-cluster method restricted to single and double excitations. The computed energies and transition moments have been analytically fitted and used in the dynamical calculations of the rovibrational energy levels, ground-state scattering length, photoassociation intensities at ultralow temperatures, and spontaneous emission coefficients from the {sup 1}{pi}{sub g}(4s3d) to the X {sup 1}{sigma}{sub g}{sup +} state. The spectroscopic constants of the theoretical ground-state potential are in a good agreement with the experimental values derived from the Fourier-transform spectra [O. Allard et al., Eur. Phys. J. D (to be published)]. The theoretical s-wave scattering length for the ground state is a=44 bohrs, suggesting that it should be possible to obtain a stable Bose-Einstein condensate of calcium atoms. Finally, the computed photoassociation intensities and spontaneous emission coefficients suggest that it should be possible to obtain cold calcium molecules by

  12. Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

    SciTech Connect

    Chen, T.; Gatchell, M.; Stockett, M. H.; Alexander, J. D.; Schmidt, H. T.; Cederquist, H.; Zettergren, H.; Zhang, Y.; Rousseau, P.; Maclot, S.; Delaunay, R.; Adoui, L.; Domaracka, A.; Huber, B. A.

    2014-06-14

    We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

  13. Selected Topics in the Physics of Heavy Ion Collisions (1/3)

    ScienceCinema

    None

    2016-07-12

    In these lectures, I discuss some classes of measurements accessible in heavy ion collisions at the LHC. How can these observables be measured, to what extent can they be calculated, and what do they tell us about the dense mesoscopic system created during the collision? In the first lecture, I shall focus in particular on measurements that constrain the spatio-temporal picture of the collisions and that measure centrality, orientations and extensions. In the subsequent lectures, I then discuss on how classes of measurements allow one to characterize collective phenomena, and to what extent these measurements can constrain the properties of matter produced in heavy ion collisions.

  14. Extending synchrotron-based atomic physics experiments into the hard X-ray region

    SciTech Connect

    LeBrun, T.

    1996-12-31

    The high-brightness, hard x-ray beams available from third-generation synchrotron sources are opening new opportunities to study the deepest inner shells of atoms, an area where little work has been done and phenomena not observed in less tightly bound inner-shells are manifested. In addition scattering processes which are weak at lower energies become important, providing another tool to investigate atomic structure as well as an opportunity to study photon/atom interactions beyond photoabsorption. In this contribution the authors discuss some of the issues related to extending synchrotron-based atomic physics experiments into the hard x-ray region from the physical and the experimental point of view. They close with a discussion of a technique, resonant Raman scattering, that may prove invaluable in determining the spectra of the very highly-excited states resulting from the excitation of deep inner shells.

  15. Formation and stimulated photodissociation of metastable molecules with emission of photon at the collision of two atoms in a laser radiation field

    NASA Astrophysics Data System (ADS)

    Gazazyan, E.; Gazazyan, A.

    2017-04-01

    The formation of metastable molecules (Feshbach resonances) at the collision of two atoms and subsequent stimulated transition to a lower unbound electronic molecular state, with emission of a photon of the laser radiation has been investigated. This can develop, in particular, for Rb 2 molecules due to resonance scattering of two Rb atoms. This process is a basis for the creation of excimer lasers. Expressions have been obtained for the cross sections of elastic and inelastic resonance scattering and the intensity of the stimulated emission of the photons.

  16. PROBING THE PHYSICAL CONDITIONS OF ATOMIC GAS AT HIGH REDSHIFT

    SciTech Connect

    Neeleman, Marcel; Wolfe, Arthur M.; Prochaska, J. Xavier

    2015-02-10

    A new method is used to measure the physical conditions of the gas in damped Lyα systems (DLAs). Using high-resolution absorption spectra of a sample of 80 DLAs, we are able to measure the ratio of the upper and lower fine-structure levels of the ground state of C{sup +} and Si{sup +}. These ratios are determined solely by the physical conditions of the gas. We explore the allowed physical parameter space using a Monte Carlo Markov chain method to constrain simultaneously the temperature, neutral hydrogen density, and electron density of each DLA. The results indicate that at least 5% of all DLAs have the bulk of their gas in a dense, cold phase with typical densities of ∼100 cm{sup –3} and temperatures below 500 K. We further find that the typical pressure of DLAs in our sample is log (P/k{sub B} ) = 3.4 (K cm{sup –3}), which is comparable to the pressure of the local interstellar medium (ISM), and that the components containing the bulk of the neutral gas can be quite small with absorption sizes as small as a few parsecs. We show that the majority of the systems are consistent with having densities significantly higher than expected for a purely canonical warm neutral medium, indicating that significant quantities of dense gas (i.e., n {sub H} > 0.1 cm{sup –3}) are required to match observations. Finally, we identify eight systems with positive detections of Si II*. These systems have pressures (P/k{sub B} ) in excess of 20,000 K cm{sup –3}, which suggest that these systems tag a highly turbulent ISM in young, star-forming galaxies.

  17. Clock Technology Development for the Laser Cooling and Atomic Physics (LCAP) Program

    NASA Technical Reports Server (NTRS)

    Klipstein, W. M.; Thompson, R. J.; Seidel, D. J.; Kohel, J.; Maleki, L.

    1998-01-01

    The Time and Frequency Sciences and Technology Group at Jet Propulsion Laboratory (JPL) has developed a laser cooling capability for flight and has been selected by NASA to support the Laser-Cooling and Atomic Physics (LCAP) program. Current work in the group includes design and development for tee two laser-cooled atomic clock experiments which have been selected for flight on the International Space Station.

  18. Otto Stern (1888-1969): The founding father of experimental atomic physics

    NASA Astrophysics Data System (ADS)

    Toennies, J. P.; Schmidt-Böcking, H.; Friedrich, B.; Lower, J. C. A.

    2011-12-01

    We review the work and life of Otto Stern who developed the molecular beam technique and with its aid laid the foundations of experimental atomic physics. Among the key results of his research are: the experimental determination of the Maxwell-Boltzmann distribution of molecular velocities (1920), experimental demonstration of space quantization of angular momentum (1922), diffraction of matter waves comprised of atoms and molecules by crystals (1931) and the determination of the magnetic dipole moments of the proton and deuteron (1933).

  19. Computation of Free-Free Transitions in Atomic Physics: Foundations

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Sucher, J.

    2003-01-01

    The amplitude T for "free-free" processes, such as bremsstrahlung or photo- absorption by an electron in the continuum in the presence of an external field, is usually written as the matrix element of the radiation operator taken between two continuum states. However, unlike the case when at least one of the states is bound, as in radiative transitions, electron capture, or the photo-effect, this expression contains an unphysical term, proportional to a delta-function and is not really the physical amplitude Tphys. This continues to be true for both the velocity and length form of the dipole approximation to the amplitude T. We first give an a priori definition of Tphys in terms of the scattering parts of the continuum functions, which has an obvious interpretation in terms of time-ordered diagrams. We then show that when the formal amplitude is modified by a long- distance cutoff, the modified form approaches Tphys as the cutoff is removed. The modified form then serves as a basis for the definition of a physical velocity dipole amplitude and this in turn leads to an equivalent length form of the dipole amplitude. This exercise provides a clear theoretical basis for many extant calculations in which cutoff factors are introduces somewhat ad hoc, as needed.

  20. LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer.

    PubMed

    Duan, Hanjun; Wu, Haifeng; Zeng, Yu; Chen, Yuebin

    2016-03-26

    In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates.

  1. LS Channel Estimation and Signal Separation for UHF RFID Tag Collision Recovery on the Physical Layer

    PubMed Central

    Duan, Hanjun; Wu, Haifeng; Zeng, Yu; Chen, Yuebin

    2016-01-01

    In a passive ultra-high frequency (UHF) radio-frequency identification (RFID) system, tag collision is generally resolved on a medium access control (MAC) layer. However, some of collided tag signals could be recovered on a physical (PHY) layer and, thus, enhance the identification efficiency of the RFID system. For the recovery on the PHY layer, channel estimation is a critical issue. Good channel estimation will help to recover the collided signals. Existing channel estimates work well for two collided tags. When the number of collided tags is beyond two, however, the existing estimates have more estimation errors. In this paper, we propose a novel channel estimate for the UHF RFID system. It adopts an orthogonal matrix based on the information of preambles which is known for a reader and applies a minimum-mean-square-error (MMSE) criterion to estimate channels. From the estimated channel, we could accurately separate the collided signals and recover them. By means of numerical results, we show that the proposed estimate has lower estimation errors and higher separation efficiency than the existing estimates. PMID:27023560

  2. New Phenomena in Physics Related with Single-Atom Electron Sources

    NASA Astrophysics Data System (ADS)

    Akamine, Yuta; Fujiwara, Kazuto; Cho, Bokulae; Oshima, Chuhei

    We have reviewed new phenomena in physics related with development of single-atom electron sources. A collimated electron beam was emitted from the single-atom situated at the top of the nano-pyramids. The following three topics have been discussed. (1) High brightness of electron beam: High-density electrons come out of the source, and overlapping of wave functions presumably produces new phenomena including anti-bunching of electrons in vacuum. Energy spectra showed characteristic features of single-atom electron sources; additional shoulders appeared in the normal spectra. 3) Stable electron emission originates from the field evaporation.

  3. ATOMIC AND MOLECULAR PHYSICS: Modelling of a DNA packaging motor

    NASA Astrophysics Data System (ADS)

    Qian, Jun; Xie, Ping; Xue, Xiao-Guang; Wang, Peng-Ye

    2009-11-01

    During the assembly of many viruses, a powerful molecular motor packages the genome into a preassembled capsid. The Bacillus subtilis phage phi29 is an excellent model system to investigate the DNA packaging mechanism because of its highly efficient in vitro DNA packaging activity and the development of a single-molecule packaging assay. Here we make use of structural and biochemical experimental data to build a physical model of DNA packaging by the phi29 DNA packaging motor. Based on the model, various dynamic behaviours such as the packaging rate, pause frequency and slip frequency under different ATP concentrations, ADP concentrations, external loads as well as capsid fillings are studied by using Monte Carlo simulation. Good agreement is obtained between the simulated and available experimental results. Moreover, we make testable predictions that should guide future experiments related to motor function.

  4. Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions

    SciTech Connect

    Not Available

    1987-01-01

    The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.

  5. Transfer of a weakly bound electron in collisions of Rydberg atoms with neutral particles. I. Long-range interaction effects in the ionic-covalent coupling

    SciTech Connect

    Lebedev, V. S. Narits, A. A.

    2013-10-15

    Ion-pair formation processes are studied in collisions of Rydberg atoms with neutral particles possessing small electron affinities. Nonadiabatic transitions from a Rydberg covalent term to an ionic term of a quasi-molecule are considered using the modified Landau-Zener theory supplemented with calculation of survival factors of an anion decaying in the Coulomb field of a positive ion core. Using the technique of irreducible tensor operators and the momentum representation of the wavefunction of a highly excited atom, exact expressions are obtained for transition matrix elements and the ionic-covalent coupling parameter. The approach developed in the paper provides the description beyond the scope of a conventional assumption about a small variation of the wavefunction of the Rydberg atom on the range of electron coordinates determined by the characteristic radius of the wavefunction of the anion. This allows one to correctly consider long-range effects of the interaction between a weakly bound electron and the neutral core of a negative ion in processes under study. It is shown by the example of thermal collisions of Xe(nf) atoms with CH{sub 3}CN molecules that this is very important for a reliable quantitative description of anion formation with a low binding energy. The results are compared with experiments and calculations performed within the framework of a number of approximate methods.

  6. Clock Technology Development in the Laser Cooling and Atomic Physics (LCAP) Program

    NASA Technical Reports Server (NTRS)

    Seidel, Dave; Thompson, R. J.; Klipstein, W. M.; Kohel, J.; Maleki, L.

    2000-01-01

    This paper presents the Laser Cooling and Atomic Physics (LCAP) program. It focuses on clock technology development. The topics include: 1) Overview of LCAP Flight Projects; 2) Space Clock 101; 3) Physics with Clocks in microgravity; 4) Space Clock Challenges; 5) LCAP Timeline; 6) International Space Station (ISS) Science Platforms; 7) ISS Express Rack; 8) Space Qualification of Components; 9) Laser Configuration; 10) Clock Rate Comparisons: GPS Carrier Phase Frequency Transfer; and 11) ISS Model Views. This paper is presented in viewgraph form.

  7. PREFACE: 7th Asian International Seminar on Atomic and Molecular Physics

    NASA Astrophysics Data System (ADS)

    Deshmukh, Pranawa C.; Chakraborty, Purushottam; Williams, Jim F.

    2007-09-01

    These proceedings arose from the 7th Asian International Seminar on Atomic and Molecular Physics (AISAMP) which was held at the Indian Institute of Technology, Madras from 4-7 December 2006. The history of the AISAMP has been reviewed by Takayanagi http://www.physics.iitm.ac.in/~aisamp7/history.html. This international seminar/conference series grew out of the Japan-China meetings which were launched in 1985, the fourth of which was held in 1992 and carried a second title: The First Asian International Seminar on Atomic and Molecular Physics (AISAMP), thus providing a formal medium for scientists in this part of the world to report periodically and exchange their scientific thoughts. The founding nations of Japan and China were joined subsequently by Korea, Taiwan, India and Australia. The aims of the symposia included bringing together leading experts and students of atomic and molecular physics, the discussion of important problems, learning and sharing modern techniques and expanding the horizons of modern atomic and molecular physics. The fields of interest ranged from atomic and molecular structure and dynamics to photon, electron and positron scattering, to quantum information processing, the effects of symmetry and many body interactions, laser cooling, cold traps, electric and magnetic fields and to atomic and molecular physics with synchrotron radiation. Particular interest was evident in new techniques and the changes of the physical properties from atomic to condensed matter. Details of the 7th AISAMP, including the topics for the special sessions and the full programme, are available online at the conference website http://www.physics.iitm.ac.in/~aisamp7/. In total, 95 presentations were made at the 7th AISAMP, these included the Invited Talks and Contributed Poster Presentations, of which 52 appear in the present Proceedings after review by expert referees, refereed to the usual standard of the Institute of Physics journal: Journal of Physics B: Atomic

  8. Search for New Physics with a Monojet and Missing Transverse Energy in 7 TeV pp collisions at CMS

    NASA Astrophysics Data System (ADS)

    Vergili, Mehmet

    2012-03-01

    We present a search for new physics in events with a single energetic jet and large missing energy in proton-proton collisions at a center-of-mass energy of 7 TeV. The search is performed using data collected by the CMS detector and corresponding to an integrated luminosity of 4.7 fb-1. The topology is a signature of many new physics models, including large extra dimensions in the framework of ADD, Unparticle production and several dark matter scenarios. Results are interpreted within the context of each of these models, including the production of dark matter.

  9. Search for New Physics with a Monojet and Missing Transverse Energy in pp Collisions at s=7TeV

    NASA Astrophysics Data System (ADS)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hänsel, S.; Hoch, M.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Krammer, M.; Liko, D.; Mikulec, I.; Pernicka, M.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Teischinger, F.; Wagner, P.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, S.; Benucci, L.; de Wolf, E. A.; Janssen, X.; Maes, J.; Maes, T.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; van Haevermaet, H.; van Mechelen, P.; van Remortel, N.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Devroede, O.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; van Doninck, W.; van Mulders, P.; van Onsem, G. P.; Villella, I.; Charaf, O.; Clerbaux, B.; de Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hammad, G. H.; Hreus, T.; Marage, P. E.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Adler, V.; Cimmino, A.; Costantini, S.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; McCartin, J.; Ryckbosch, D.; Thyssen, F.; Tytgat, M.; Vanelderen, L.; Verwilligen, P.; Walsh, S.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Caudron, J.; Ceard, L.; Cortina Gil, E.; de Favereau de Jeneret, J.; Delaere, C.; Favart, D.; Giammanco, A.; Grégoire, G.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Ovyn, S.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Beliy, N.; Caebergs, T.; Daubie, E.; Alves, G. A.; Brito, L.; de Jesus Damiao, D.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; da Costa, E. M.; de Oliveira Martins, C.; Fonseca de Souza, S.; Mundim, L.; Nogima, H.; Oguri, V.; Prado da Silva, W. L.; Santoro, A.; Silva Do Amaral, S. M.; Sznajder, A.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Darmenov, N.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Dimitrov, A.; Hadjiiska, R.; Karadzhinova, A.; Kozhuharov, V.; Litov, L.; Mateev, M.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Ban, Y.; Guo, S.; Guo, Y.; Li, W.; Mao, Y.; Qian, S. J.; Teng, H.; Zhu, B.; Zou, W.; Cabrera, A.; Gomez Moreno, B.; Ocampo Rios, A. A.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Lelas, K.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Dzelalija, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Morovic, S.; Attikis, A.; Galanti, M.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M., Jr.; Awad, A.; Khalil, S.; Radi, A.; Hektor, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Azzolini, V.; Eerola, P.; Fedi, G.; Czellar, S.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Sillou, D.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Gentit, F. X.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Marionneau, M.; Millischer, L.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Verrecchia, P.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Dahms, T.; Dobrzynski, L.; Elgammal, S.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Thiebaux, C.; Wyslouch, B.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Greder, S.; Juillot, P.; Karim, M.; Le Bihan, A.-C.; Mikami, Y.; van Hove, P.; Fassi, F.; Mercier, D.; Baty, C.; Beauceron, S.; Beaupere, N.; Bedjidian, M.; Bondu, O.; Boudoul, G.; Boumediene, D.; Brun, H.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Ille, B.; Kurca, T.; Le Grand, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sordini, V.; Tosi, S.; Tschudi, Y.; Verdier, P.; Lomidze, D.; Anagnostou, G.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.; Klein, K.; Merz, J.; Mohr, N.; Ostapchuk, A.; Perieanu, A.; Raupach, F.; Sammet, J.; Schael, S.; Sprenger, D.; Weber, H.; Weber, M.; Wittmer, B.; Ata, M.; Dietz-Laursonn, E.; Erdmann, M.; Hebbeker, T.; Hinzmann, A.; Hoepfner, K.; Klimkovich, T.; Klingebiel, D.; Kreuzer, P.; Lanske, D.; Lingemann, J.; Magass, C.; Merschmeyer, M.; Meyer, A.; Papacz, P.; Pieta, H.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Steggemann, J.; Teyssier, D.; Bontenackels, M.; Davids, M.; Duda, M.; Flügge, G.; Geenen, H.; Giffels, M.; Haj Ahmad, W.; Heydhausen, D.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Linn, A.; Nowack, A.; Perchalla, L.; Pooth, O.; Rennefeld, J.; Sauerland, P.; Stahl, A.; Thomas, M.; Tornier, D.; Zoeller, M. H.; Aldaya Martin, M.; Behrenhoff, W.; Behrens, U.; Bergholz, M.; Bethani, A.; Borras, K.; Cakir, A.; Campbell, A.; Castro, E.; Dammann, D.; Eckerlin, G.; Eckstein, D.; Flossdorf, A.; Flucke, G.; Geiser, A.; Hauk, J.; Jung, H.; Kasemann, M.; Katkov, I.; Katsas, P.; Kleinwort, C.; Kluge, H.; Knutsson, A.; Krämer, M.; Krücker, D.; Kuznetsova, E.; Lange, W.; Lohmann, W.; Mankel, R.; Marienfeld, M.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mnich, J.; Mussgiller, A.; Olzem, J.; Petrukhin, A.; Pitzl, D.; Raspereza, A.; Raval, A.; Rosin, M.; Schmidt, R.; Schoerner-Sadenius, T.; Sen, N.; Spiridonov, A.; Stein, M.; Tomaszewska, J.; Walsh, R.; Wissing, C.; Autermann, C.; Blobel, V.; Bobrovskyi, S.; Draeger, J.; Enderle, H.; Gebbert, U.; Görner, M.; Kaschube, K.; Kaussen, G.; Kirschenmann, H.; Klanner, R.; Lange, J.; Mura, B.; Naumann-Emme, S.; Nowak, F.; Pietsch, N.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schröder, M.; Schum, T.; Schwandt, J.; Stadie, H.; Steinbrück, G.; Thomsen, J.; Barth, C.; Bauer, J.; Berger, J.; Buege, V.; Chwalek, T.; de Boer, W.; Dierlamm, A.; Dirkes, G.; Feindt, M.; Gruschke, J.; Hackstein, C.; Hartmann, F.; Heinrich, M.; Held, H.; Hoffmann, K. H.; Honc, S.; Komaragiri, J. R.; Kuhr, T.; Martschei, D.; Mueller, S.; Müller, Th.; Niegel, M.; Oberst, O.; Oehler, A.; Ott, J.; Peiffer, T.; Quast, G.; Rabbertz, K.; Ratnikov, F.; Ratnikova, N.; Renz, M.; Saout, C.; Scheurer, A.; Schieferdecker, P.; Schilling, F.-P.; Schott, G.; Simonis, H. J.; Stober, F. M.; Troendle, D.; Wagner-Kuhr, J.; Weiler, T.; Zeise, M.; Zhukov, V.; Ziebarth, E. B.; Daskalakis, G.; Geralis, T.; Kesisoglou, S.; Kyriakis, A.; Loukas, D.; Manolakos, I.; Markou, A.; Markou, C.; Mavrommatis, C.; Ntomari, E.; Petrakou, E.; Gouskos, L.; Mertzimekis, T. J.; Panagiotou, A.; Stiliaris, E.; Evangelou, I.; Foudas, C.; Kokkas, P.; Manthos, N.; Papadopoulos, I.; Patras, V.; Triantis, F. A.; Aranyi, A.; Bencze, G.; Boldizsar, L.; Hajdu, C.; Hidas, P.; Horvath, D.; Kapusi, A.; Krajczar, K.; Sikler, F.; Veres, G. I.; Vesztergombi, G.; Beni, N.; Molnar, J.; Palinkas, J.; Szillasi, Z.; Veszpremi, V.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Beri, S. B.; Bhatnagar, V.; Dhingra, N.; Gupta, R.; Jindal, M.; Kaur, M.; Kohli, J. M.; Mehta, M. Z.; Nishu, N.; Saini, L. K.; Sharma, A.; Singh, A. P.; Singh, J.; Singh, S. P.; Ahuja, S.; Choudhary, B. C.; Gupta, P.; Jain, S.; Jain, S.; Kumar, A.; Kumar, A.; Naimuddin, M.; Ranjan, K.; Shivpuri, R. K.; Banerjee, S.; Bhattacharya, S.; Dutta, S.; Gomber, B.; Khurana, R.; Sarkar, S.; Choudhury, R. K.; Dutta, D.; Kailas, S.; Kumar, V.; Mehta, P.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Aziz, T.; Guchait, M.; Gurtu, A.; Maity, M.; Majumder, D.; Majumder, G.; Mazumdar, K.; Mohanty, G. B.; Saha, A.; Sudhakar, K.; Wickramage, N.; Banerjee, S.; Dugad, S.; Mondal, N. K.; Arfaei, H.; Bakhshiansohi, H.; Etesami, S. M.; Fahim, A.; Hashemi, M.; Jafari, A.; Khakzad, M.; Mohammadi, A.; Mohammadi Najafabadi, M.; Paktinat Mehdiabadi, S.; Safarzadeh, B.; Zeinali, M.; Abbrescia, M.; Barbone, L.; Calabria, C.; Colaleo, A.; Creanza, D.; de Filippis, N.; de Palma, M.; Fiore, L.; Iaselli, G.; Lusito, L.; Maggi, G.; Maggi, M.; Manna, N.; Marangelli, B.; My, S.; Nuzzo, S.; Pacifico, N.; Pierro, G. A.; Pompili, A.; Pugliese, G.; Romano, F.; Roselli, G.; Selvaggi, G.; Silvestris, L.; Trentadue, R.; Tupputi, S.; Zito, G.; Abbiendi, G.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Giunta, M.; Grandi, C.; Marcellini, S.; Masetti, G.; Meneghelli, M.; Montanari, A.; Navarria, F. L.; Odorici, F.; Perrotta, A.; Primavera, F.; Rossi, A. M.; Rovelli, T.; Siroli, G.; Travaglini, R.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Frosali, S.; Gallo, E.; Gonzi, S.; Lenzi, P.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Tropiano, A.; Benussi, L.; Bianco, S.; Colafranceschi, S.; Fabbri, F.; Piccolo, D.; Fabbricatore, P.; Musenich, R.; Benaglia, A.; de Guio, F.; Di Matteo, L.; Gennai, S.; Ghezzi, A.; Malvezzi, S.; Martelli, A.; Massironi, A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Ragazzi, S.; Redaelli, N.; Sala, S.; Tabarelli de Fatis, T.; Buontempo, S.; Carrillo Montoya, C. A.; Cavallo, N.; de Cosa, A.; Fabozzi, F.; Iorio, A. O. M.; Lista, L.; Merola, M.; Paolucci, P.; Azzi, P.; Bacchetta, N.; Bellan, P.; Biasotto, M.; Bisello, D.; Branca, A.; Carlin, R.; Checchia, P.; Dorigo, T.; Gasparini, F.; Gozzelino, A.; Gulmini, M.; Lacaprara, S.; Lazzizzera, I.; Margoni, M.; Maron, G.; Meneguzzo, A. T.; Nespolo, M.; Perrozzi, L.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Triossi, A.; Vanini, S.; Zotto, P.; Zumerle, G.; Baesso, P.; Berzano, U.; Ratti, S. P.; Riccardi, C.; Torre, P.; Vitulo, P.; Viviani, C.; Biasini, M.; Bilei, G. M.; Caponeri, B.; Fanò, L.; Lariccia, P.; Lucaroni, A.; Mantovani, G.; Menichelli, M.; Nappi, A.; Romeo, F.; Santocchia, A.; Taroni, S.; Valdata, M.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Broccolo, G.; Castaldi, R.; D'Agnolo, R. T.; Dell'Orso, R.; Fiori, F.; Foà, L.; Giassi, A.; Kraan, A.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Segneri, G.; Serban, A. T.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Del Re, D.; di Marco, E.; Diemoz, M.; Franci, D.; Grassi, M.; Longo, E.; Meridiani, P.; Nourbakhsh, S.; Organtini, G.; Pandolfi, F.; Paramatti, R.; Rahatlou, S.; Rovelli, C.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Biino, C.; Botta, C.; Cartiglia, N.; Castello, R.; Costa, M.; Demaria, N.; Graziano, A.; Mariotti, C.; Marone, M.; Maselli, S.; Migliore, E.; Mila, G.; Monaco, V.; Musich, M.; Obertino, M. M.; Pastrone, N.; Pelliccioni, M.; Potenza, A.; Romero, A.; Ruspa, M.; Sacchi, R.; Sola, V.; Solano, A.; Staiano, A.; Vilela Pereira, A.; Belforte, S.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; Montanino, D.; Penzo, A.; Heo, S. G.; Nam, S. K.; Chang, S.; Chung, J.; Kim, D. H.; Kim, G. N.; Kim, J. E.; Kong, D. J.; Park, H.; Ro, S. R.; Son, D.; Son, D. C.; Son, T.; Kim, Zero; Kim, J. Y.; Song, S.; Choi, S.; Hong, B.; Jo, M.; Kim, H.; Kim, J. H.; Kim, T. J.; Lee, K. S.; Moon, D. H.; Park, S. K.; Sim, K. S.; Choi, M.; Kang, S.; Kim, H.; Park, C.; Park, I. C.; Park, S.; Ryu, G.; Choi, Y.; Choi, Y. K.; Goh, J.; Kim, M. S.; Lee, J.; Lee, S.; Seo, H.; Yu, I.; Bilinskas, M. J.; Grigelionis, I.; Janulis, M.; Martisiute, D.; Petrov, P.; Sabonis, T.; Castilla-Valdez, H.; de La Cruz-Burelo, E.; Heredia-de La Cruz, I.; Lopez-Fernandez, R.; Magaña Villalba, R.; Sánchez-Hernández, A.; Villasenor-Cendejas, L. M.; Carrillo Moreno, S.; Vazquez Valencia, F.; Salazar Ibarguen, H. A.; Casimiro Linares, E.; Morelos Pineda, A.; Reyes-Santos, M. A.; Krofcheck, D.; Tam, J.; Butler, P. H.; Doesburg, R.; Silverwood, H.; Ahmad, M.; Ahmed, I.; Asghar, M. I.; Hoorani, H. R.; Khan, W. A.; Khurshid, T.; Qazi, S.; Brona, G.; Cwiok, M.; Dominik, W.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Frueboes, T.; Gokieli, R.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Wrochna, G.; Zalewski, P.; Almeida, N.; Bargassa, P.; David, A.; Faccioli, P.; Ferreira Parracho, P. G.; Gallinaro, M.; Musella, P.; Nayak, A.; Pela, J.; Ribeiro, P. Q.; Seixas, J.; Varela, J.; Afanasiev, S.; Belotelov, I.; Bunin, P.; Golutvin, I.; Karjavin, V.; Kozlov, G.; Lanev, A.; Moisenz, P.; Palichik, V.; Perelygin, V.; Savina, M.; Shmatov, S.; Smirnov, V.; Volodko, A.; Zarubin, A.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Vorobyev, An.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Kirsanov, M.; Krasnikov, N.; Matveev, V.; Pashenkov, A.; Toropin, A.; Troitsky, S.; Epshteyn, V.; Gavrilov, V.; Kaftanov, V.; Kossov, M.; Krokhotin, A.; Lychkovskaya, N.; Popov, V.; Safronov, G.; Semenov, S.; Stolin, V.; Vlasov, E.; Zhokin, A.; Boos, E.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Kodolova, O.; Lokhtin, I.; Markina, A.; Obraztsov, S.; Perfilov, M.; Petrushanko, S.; Sarycheva, L.; Savrin, V.; Snigirev, A.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Rusakov, S. V.; Vinogradov, A.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Grishin, V.; Kachanov, V.; Konstantinov, D.; Korablev, A.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Tourtchanovitch, L.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Djordjevic, M.; Krpic, D.; Milosevic, J.; Aguilar-Benitez, M.; Alcaraz Maestre, J.; Arce, P.; Battilana, C.; Calvo, E.; Cepeda, M.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; de La Cruz, B.; Delgado Peris, A.; Diez Pardos, C.; Domínguez Vázquez, D.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Ferrando, A.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Merino, G.; Puerta Pelayo, J.; Redondo, I.; Romero, L.; Santaolalla, J.; Soares, M. S.; Willmott, C.; Albajar, C.; Codispoti, G.; de Trocóniz, J. F.; Cuevas, J.; Fernandez Menendez, J.; Folgueras, S.; Gonzalez Caballero, I.; Lloret Iglesias, L.; Vizan Garcia, J. M.; Brochero Cifuentes, J. A.; Cabrillo, I. J.; Calderon, A.; Chuang, S. H.; Duarte Campderros, J.; Felcini, M.; Fernandez, M.; Gomez, G.; Gonzalez Sanchez, J.; Jorda, C.; Lobelle Pardo, P.; Lopez Virto, A.; Marco, J.; Marco, R.; Martinez Rivero, C.; Matorras, F.; Munoz Sanchez, F. J.; Piedra Gomez, J.; Rodrigo, T.; Rodríguez-Marrero, A. Y.; Ruiz-Jimeno, A.; Scodellaro, L.; Sobron Sanudo, M.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Baillon, P.; Ball, A. H.; Barney, D.; Bell, A. J.; Benedetti, D.; Bernet, C.; Bialas, W.; Bloch, P.; Bocci, A.; Bolognesi, S.; Bona, M.; Breuker, H.; Bunkowski, K.; Camporesi, T.; Cerminara, G.; Christiansen, T.; Coarasa Perez, J. A.; Curé, B.; D'Enterria, D.; de Roeck, A.; di Guida, S.; Dupont-Sagorin, N.; Elliott-Peisert, A.; Frisch, B.; Funk, W.; Gaddi, A.; Georgiou, G.; Gerwig, H.; Gigi, D.; Gill, K.; Giordano, D.; Glege, F.; Gomez-Reino Garrido, R.; Gouzevitch, M.; Govoni, P.; Gowdy, S.; Guiducci, L.; Hansen, M.; Hartl, C.; Harvey, J.; Hegeman, J.; Hegner, B.; Hoffmann, H. F.; Honma, A.; Innocente, V.; Janot, P.; Kaadze, K.; Karavakis, E.; Lecoq, P.; Lourenço, C.; Mäki, T.; Malberti, M.; Malgeri, L.; Mannelli, M.; Masetti, L.; Maurisset, A.; Meijers, F.; Mersi, S.; Meschi, E.; Moser, R.; Mozer, M. U.; Mulders, M.; Nesvold, E.; Nguyen, M.; Orimoto, T.; Orsini, L.; Perez, E.; Petrilli, A.; Pfeiffer, A.; Pierini, M.; Pimiä, M.; Piparo, D.; Polese, G.; Racz, A.; Rodrigues Antunes, J.; Rolandi, G.; Rommerskirchen, T.; Rovere, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Segoni, I.; Sharma, A.; Siegrist, P.; Simon, M.; Sphicas, P.; Spiropulu, M.; Stoye, M.; Tropea, P.; Tsirou, A.; Vichoudis, P.; Voutilainen, M.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Gabathuler, K.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; König, S.; Kotlinski, D.; Langenegger, U.; Meier, F.; Renker, D.; Rohe, T.; Sibille, J.; Starodumov, A.; Bäni, L.; Bortignon, P.; Caminada, L.; Chanon, N.; Chen, Z.; Cittolin, S.; Dissertori, G.; Dittmar, M.; Eugster, J.; Freudenreich, K.; Grab, C.; Hintz, W.; Lecomte, P.; Lustermann, W.; Marchica, C.; Martinez Ruiz Del Arbol, P.; Milenovic, P.; Moortgat, F.; Nägeli, C.; Nef, P.; Nessi-Tedaldi, F.; Pape, L.; Pauss, F.; Punz, T.; Rizzi, A.; Ronga, F. J.; Rossini, M.; Sala, L.; Sanchez, A. K.; Sawley, M.-C.; Stieger, B.; Tauscher, L.; Thea, A.; Theofilatos, K.; Treille, D.; Urscheler, C.; Wallny, R.; Weber, M.; Wehrli, L.; Weng, J.; Aguilo, E.; Amsler, C.; Chiochia, V.; de Visscher, S.; Favaro, C.; Ivova Rikova, M.; Millan Mejias, B.; Otiougova, P.; Regenfus, C.; Robmann, P.; Schmidt, A.; Snoek, H.; Chang, Y. H.; Chen, K. H.; Kuo, C. M.; Li, S. W.; Lin, W.; Liu, Z. K.; Lu, Y. J.; Mekterovic, D.; Volpe, R.; Wu, J. H.; Yu, S. S.; Bartalini, P.; Chang, P.; Chang, Y. H.; Chang, Y. W.; Chao, Y.; Chen, K. F.; Hou, W.-S.; Hsiung, Y.; Kao, K. Y.; Lei, Y. J.; Lu, R.-S.; Shiu, J. G.; Tzeng, Y. M.; Wang, M.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Hos, I.; Kangal, E. E.; Kayis Topaksu, A.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Polatoz, A.; Sogut, K.; Sunar Cerci, D.; Tali, B.; Topakli, H.; Uzun, D.; Vergili, L. N.; Vergili, M.; Akin, I. V.; Aliev, T.; Bilin, B.; Bilmis, S.; Deniz, M.; Gamsizkan, H.; Guler, A. M.; Ocalan, K.; Ozpineci, A.; Serin, M.; Sever, R.; Surat, U. E.; Yildirim, E.; Zeyrek, M.; Deliomeroglu, M.; Demir, D.; Gülmez, E.; Isildak, B.; Kaya, M.; Kaya, O.; Özbek, M.; Ozkorucuklu, S.; Sonmez, N.; Levchuk, L.; Bostock, F.; Brooke, J. J.; Cheng, T. L.; Clement, E.; Cussans, D.; Frazier, R.; Goldstein, J.; Grimes, M.; Hansen, M.; Hartley, D.; Heath, G. P.; Heath, H. F.; Kreczko, L.; Metson, S.; Newbold, D. M.; Nirunpong, K.; Poll, A.; Senkin, S.; Smith, V. J.; Ward, S.; Basso, L.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Camanzi, B.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Jackson, J.; Kennedy, B. W.; Olaiya, E.; Petyt, D.; Radburn-Smith, B. C.; Shepherd-Themistocleous, C. H.; Tomalin, I. R.; Womersley, W. J.; Worm, S. D.; Bainbridge, R.; Ball, G.; Ballin, J.; Beuselinck, R.; Buchmuller, O.; Colling, D.; Cripps, N.; Cutajar, M.; Davies, G.; Della Negra, M.; Ferguson, W.; Fulcher, J.; Futyan, D.; Gilbert, A.; Guneratne Bryer, A.; Hall, G.; Hatherell, Z.; Hays, J.; Iles, G.; Jarvis, M.; Karapostoli, G.; Lyons, L.; Macevoy, B. C.; Magnan, A.-M.; Marrouche, J.; Mathias, B.; Nandi, R.; Nash, J.; Nikitenko, A.; Papageorgiou, A.; Pesaresi, M.; Petridis, K.; Pioppi, M.; Raymond, D. M.; Rogerson, S.; Rompotis, N.; Rose, A.; Ryan, M. J.; Seez, C.; Sharp, P.; Sparrow, A.; Tapper, A.; Tourneur, S.; Vazquez Acosta, M.; Virdee, T.; Wakefield, S.; Wardle, N.; Wardrope, D.; Whyntie, T.; Barrett, M.; Chadwick, M.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leslie, D.; Martin, W.; Reid, I. D.; Teodorescu, L.; Hatakeyama, K.; Liu, H.; Henderson, C.; Bose, T.; Carrera Jarrin, E.; Fantasia, C.; Heister, A.; St. John, J.; Lawson, P.; Lazic, D.; Rohlf, J.; Sperka, D.; Sulak, L.; Avetisyan, A.; Bhattacharya, S.; Chou, J. P.; Cutts, D.; Ferapontov, A.; Heintz, U.; Jabeen, S.; Kukartsev, G.; Landsberg, G.; Luk, M.; Narain, M.; Nguyen, D.; Segala, M.; Sinthuprasith, T.; Speer, T.; Tsang, K. V.; Breedon, R.; Breto, G.; Calderon de La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Cox, P. T.; Dolen, J.; Erbacher, R.; Friis, E.; Ko, W.; Kopecky, A.; Lander, R.; Liu, H.; Maruyama, S.; Miceli, T.; Nikolic, M.; Pellett, D.; Robles, J.; Salur, S.; Schwarz, T.; Searle, M.; Smith, J.; Squires, M.; Tripathi, M.; Vasquez Sierra, R.; Veelken, C.; Andreev, V.; Arisaka, K.; Cline, D.; Cousins, R.; Deisher, A.; Duris, J.; Erhan, S.; Farrell, C.; Hauser, J.; Ignatenko, M.; Jarvis, C.; Plager, C.; Rakness, G.; Schlein, P.; Tucker, J.; Valuev, V.; Babb, J.; Chandra, A.; Clare, R.; Ellison, J.; Gary, J. W.; Giordano, F.; Hanson, G.; Jeng, G. Y.; Kao, S. C.; Liu, F.; Liu, H.; Long, O. R.; Luthra, A.; Nguyen, H.; Shen, B. C.; Stringer, R.; Sturdy, J.; Sumowidagdo, S.; Wilken, R.; Wimpenny, S.; Andrews, W.; Branson, J. G.; Cerati, G. B.; Evans, D.; Golf, F.; Holzner, A.; Kelley, R.; Lebourgeois, M.; Letts, J.; Mangano, B.; Padhi, S.; Palmer, C.; Petrucciani, G.; Pi, H.; Pieri, M.; Ranieri, R.; Sani, M.; Sharma, V.; Simon, S.; Sudano, E.; Tadel, M.; Tu, Y.; Vartak, A.; Wasserbaech, S.; Würthwein, F.; Yagil, A.; Yoo, J.; Barge, D.; Bellan, R.; Campagnari, C.; D'Alfonso, M.; Danielson, T.; Flowers, K.; Geffert, P.; Incandela, J.; Justus, C.; Kalavase, P.; Koay, S. A.; Kovalskyi, D.; Krutelyov, V.; Lowette, S.; McColl, N.; Pavlunin, V.; Rebassoo, F.; Ribnik, J.; Richman, J.; Rossin, R.; Stuart, D.; To, W.; Vlimant, J. R.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Gataullin, M.; Ma, Y.; Mott, A.; Newman, H. B.; Rogan, C.; Shin, K.; Timciuc, V.; Traczyk, P.; Veverka, J.; Wilkinson, R.; Yang, Y.; Zhu, R. Y.; Akgun, B.; Carroll, R.; Ferguson, T.; Iiyama, Y.; Jang, D. W.; Jun, S. Y.; Liu, Y. F.; Paulini, M.; Russ, J.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Dinardo, M. E.; Drell, B. R.; Edelmaier, C. J.; Ford, W. T.; Gaz, A.; Heyburn, B.; Luiggi Lopez, E.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Ulmer, K. A.; Wagner, S. R.; Zang, S. L.; Agostino, L.; Alexander, J.; Cassel, D.; Chatterjee, A.; Das, S.; Eggert, N.; Gibbons, L. K.; Heltsley, B.; Hopkins, W.; Khukhunaishvili, A.; Kreis, B.; Nicolas Kaufman, G.; Patterson, J. R.; Puigh, D.; Ryd, A.; Salvati, E.; Shi, X.; Sun, W.; Teo, W. D.; Thom, J.; Thompson, J.; Vaughan, J.; Weng, Y.; Winstrom, L.; Wittich, P.; Biselli, A.; Cirino, G.; Winn, D.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Atac, M.; Bakken, J. A.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bloch, I.; Borcherding, F.; Burkett, K.; Butler, J. N.; Chetluru, V.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Cooper, W.; Eartly, D. P.; Elvira, V. D.; Esen, S.; Fisk, I.; Freeman, J.; Gao, Y.; Gottschalk, E.; Green, D.; Gunthoti, K.; Gutsche, O.; Hanlon, J.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Jensen, H.; Johnson, M.; Joshi, U.; Khatiwada, R.; Klima, B.; Kousouris, K.; Kunori, S.; Kwan, S.; Leonidopoulos, C.; Limon, P.; Lincoln, D.; Lipton, R.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Mason, D.; McBride, P.; Miao, T.; Mishra, K.; Mrenna, S.; Musienko, Y.; Newman-Holmes, C.; O'Dell, V.; Pordes, R.; Prokofyev, O.; Saoulidou, N.; Sexton-Kennedy, E.; Sharma, S.; Spalding, W. J.; Spiegel, L.; Tan, P.; Taylor, L.; Tkaczyk, S.; Uplegger, L.; Vaandering, E. W.; Vidal, R.; Whitmore, J.; Wu, W.; Yang, F.; Yumiceva, F.; Yun, J. C.; Acosta, D.; Avery, P.; Bourilkov, D.; Chen, M.; de Gruttola, M.; di Giovanni, G. P.; Dobur, D.; Drozdetskiy, A.; Field, R. D.; Fisher, M.; Fu, Y.; Furic, I. K.; Gartner, J.; Kim, B.; Konigsberg, J.; Korytov, A.; Kropivnitskaya, A.; Kypreos, T.; Matchev, K.; Mitselmakher, G.; Muniz, L.; Prescott, C.; Remington, R.; Schmitt, M.; Scurlock, B.; Sellers, P.; Skhirtladze, N.; Snowball, M.; Wang, D.; Yelton, J.; Zakaria, M.; Ceron, C.; Gaultney, V.; Kramer, L.; Lebolo, L. M.; Linn, S.; Markowitz, P.; Martinez, G.; Mesa, D.; Rodriguez, J. L.; Adams, T.; Askew, A.; Bochenek, J.; Chen, J.; Diamond, B.; Gleyzer, S. V.; Haas, J.; Hagopian, S.; Hagopian, V.; Jenkins, M.; Johnson, K. F.; Prosper, H.; Quertenmont, L.; Sekmen, S.; Veeraraghavan, V.; Baarmand, M. M.; Dorney, B.; Guragain, S.; Hohlmann, M.; Kalakhety, H.; Ralich, R.; Vodopiyanov, I.; Adams, M. R.; Anghel, I. M.; Apanasevich, L.; Bai, Y.; Bazterra, V. E.; Betts, R. R.; Callner, J.; Cavanaugh, R.; Dragoiu, C.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Khalatyan, S.; Kunde, G. J.; Lacroix, F.; Malek, M.; O'Brien, C.; Silkworth, C.; Silvestre, C.; Smoron, A.; Strom, D.; Varelas, N.; Akgun, U.; Albayrak, E. A.; Bilki, B.; Clarida, W.; Duru, F.; Lae, C. K.; McCliment, E.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Newsom, C. R.; Norbeck, E.; Olson, J.; Onel, Y.; Ozok, F.; Sen, S.; Wetzel, J.; Yetkin, T.; Yi, K.; Barnett, B. A.; Blumenfeld, B.; Bonato, A.; Eskew, C.; Fehling, D.; Giurgiu, G.; Gritsan, A. V.; Guo, Z. J.; Hu, G.; Maksimovic, P.; Rappoccio, S.; Swartz, M.; Tran, N. V.; Whitbeck, A.; Baringer, P.; Bean, A.; Benelli, G.; Grachov, O.; Kenny, R. P., III; Murray, M.; Noonan, D.; Sanders, S.; Wood, J. S.; Zhukova, V.; Barfuss, A. F.; Bolton, T.; Chakaberia, I.; Ivanov, A.; Khalil, S.; Makouski, M.; Maravin, Y.; Shrestha, S.; Svintradze, I.; Wan, Z.; Gronberg, J.; Lange, D.; Wright, D.; Baden, A.; Boutemeur, M.; Eno, S. C.; Ferencek, D.; Gomez, J. A.; Hadley, N. J.; Kellogg, R. G.; Kirn, M.; Lu, Y.; Mignerey, A. C.; Rossato, K.; Rumerio, P.; Santanastasio, F.; Skuja, A.; Temple, J.; Tonjes, M. B.; Tonwar, S. C.; Twedt, E.; Alver, B.; Bauer, G.; Bendavid, J.; Busza, W.; Butz, E.; Cali, I. A.; Chan, M.; Dutta, V.; Everaerts, P.; Gomez Ceballos, G.; Goncharov, M.; Hahn, K. A.; Harris, P.; Kim, Y.; Klute, M.; Lee, Y.-J.; Li, W.; Loizides, C.; Luckey, P. D.; Ma, T.; Nahn, S.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Rudolph, M.; Stephans, G. S. F.; Stöckli, F.; Sumorok, K.; Sung, K.; Wenger, E. A.; Wolf, R.; Xie, S.; Yang, M.; Yilmaz, Y.; Yoon, A. S.; Zanetti, M.; Cooper, S. I.; Cushman, P.; Dahmes, B.; de Benedetti, A.; Dudero, P. R.; Franzoni, G.; Haupt, J.; Klapoetke, K.; Kubota, Y.; Mans, J.; Pastika, N.; Rekovic, V.; Rusack, R.; Sasseville, M.; Singovsky, A.; Tambe, N.; Cremaldi, L. M.; Godang, R.; Kroeger, R.; Perera, L.; Rahmat, R.; Sanders, D. A.; Summers, D.; Bloom, K.; Bose, S.; Butt, J.; Claes, D. R.; Dominguez, A.; Eads, M.; Keller, J.; Kelly, T.; Kravchenko, I.; Lazo-Flores, J.; Malbouisson, H.; Malik, S.; Snow, G. R.; Baur, U.; Godshalk, A.; Iashvili, I.; Jain, S.; Kharchilava, A.; Kumar, A.; Shipkowski, S. P.; Smith, K.; Zennamo, J.; Alverson, G.; Barberis, E.; Baumgartel, D.; Boeriu, O.; Chasco, M.; Reucroft, S.; Swain, J.; Trocino, D.; Wood, D.; Zhang, J.; Anastassov, A.; Kubik, A.; Odell, N.; Ofierzynski, R. A.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Velasco, M.; Won, S.; Antonelli, L.; Berry, D.; Brinkerhoff, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kolb, J.; Kolberg, T.; Lannon, K.; Luo, W.; Lynch, S.; Marinelli, N.; Morse, D. M.; Pearson, T.; Ruchti, R.; Slaunwhite, J.; Valls, N.; Wayne, M.; Ziegler, J.; Bylsma, B.; Durkin, L. S.; Gu, J.; Hill, C.; Killewald, P.; Kotov, K.; Ling, T. Y.; Rodenburg, M.; Williams, G.; Adam, N.; Berry, E.; Elmer, P.; Gerbaudo, D.; Halyo, V.; Hebda, P.; Hunt, A.; Jones, J.; Laird, E.; Lopes Pegna, D.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Acosta, J. G.; Huang, X. T.; Lopez, A.; Mendez, H.; Oliveros, S.; Ramirez Vargas, J. E.; Zatserklyaniy, A.; Alagoz, E.; Barnes, V. E.; Bolla, G.; Borrello, L.; Bortoletto, D.; de Mattia, M.; Everett, A.; Garfinkel, A. F.; Gutay, L.; Hu, Z.; Jones, M.; Koybasi, O.; Kress, M.; Laasanen, A. T.; Leonardo, N.; Liu, C.; Maroussov, V.; Merkel, P.; Miller, D. H.; Neumeister, N.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Yoo, H. D.; Zablocki, J.; Zheng, Y.; Jindal, P.; Parashar, N.; Boulahouache, C.; Ecklund, K. M.; Geurts, F. J. M.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; Chung, Y. S.; Covarelli, R.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Flacher, H.; Garcia-Bellido, A.; Goldenzweig, P.; Gotra, Y.; Han, J.; Harel, A.; Miner, D. C.; Orbaker, D.; Petrillo, G.; Sakumoto, W.; Vishnevskiy, D.; Zielinski, M.; Bhatti, A.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Lungu, G.; Malik, S.; Mesropian, C.; Yan, M.; Atramentov, O.; Barker, A.; Duggan, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Hits, D.; Lath, A.; Panwalkar, S.; Patel, R.; Rose, K.; Schnetzer, S.; Somalwar, S.; Stone, R.; Thomas, S.; Cerizza, G.; Hollingsworth, M.; Spanier, S.; Yang, Z. C.; York, A.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Gurrola, A.; Kamon, T.; Khotilovich, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Pivarski, J.; Safonov, A.; Sengupta, S.; Tatarinov, A.; Toback, D.; Weinberger, M.; Akchurin, N.; Bardak, C.; Damgov, J.; Jeong, C.; Kovitanggoon, K.; Lee, S. W.; Libeiro, T.; Mane, P.; Roh, Y.; Sill, A.; Volobouev, I.; Wigmans, R.; Yazgan, E.; Appelt, E.; Brownson, E.; Engh, D.; Florez, C.; Gabella, W.; Issah, M.; Johns, W.; Kurt, P.; Maguire, C.; Melo, A.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Balazs, M.; Boutle, S.; Cox, B.; Francis, B.; Hirosky, R.; Ledovskoy, A.; Lin, C.; Neu, C.; Yohay, R.; Gollapinni, S.; Harr, R.; Karchin, P. E.; Lamichhane, P.; Mattson, M.; Milstène, C.; Sakharov, A.; Anderson, M.; Bachtis, M.; Bellinger, J. N.; Carlsmith, D.; Dasu, S.; Efron, J.; Flood, K.; Gray, L.; Grogg, K. S.; Grothe, M.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Klukas, J.; Lanaro, A.; Lazaridis, C.; Leonard, J.; Loveless, R.; Mohapatra, A.; Palmonari, F.; Reeder, D.; Ross, I.; Savin, A.; Smith, W. H.; Swanson, J.; Weinberg, M.

    2011-11-01

    A study of events with missing transverse energy and an energetic jet is performed using pp collision data at a center-of-mass energy of 7 TeV. The data were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 36pb-1. An excess of these events over standard model contributions is a signature of new physics such as large extra dimensions and unparticles. The number of observed events is in good agreement with the prediction of the standard model, and significant extension of the current limits on parameters of new physics benchmark models is achieved.

  10. Do General Physics Textbooks Discuss Scientists' Ideas about Atomic Structure? A Case in Korea

    ERIC Educational Resources Information Center

    Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho

    2013-01-01

    Research in science education has recognized the importance of teaching atomic structure within a history and philosophy of science perspective. The objective of this study is to evaluate general physics textbooks published in Korea based on the eight criteria developed in previous research. The result of this study shows that Korean general…

  11. Radiative and nonradiative charge transfer in collisions of Be{sup 2+} and B{sup 3+} ions with H atoms

    SciTech Connect

    Liu, C. H.; Wang, J. G.; Liu, L.; Qu, Y. Z.; Janev, R. K.

    2010-08-15

    The nonradiative charge-transfer processes in Be{sup 2+}(1s{sup 2})+H(1s) and B{sup 3+}(1s{sup 2})+H(1s) collisions are investigated by the quantal molecular orbital close-coupling method in the energy range of 10{sup -5}eV/u-10 keV/u and by the two-center atomic-orbital close-coupling method in the energy range of 0.1-100 keV/u. The radiative charge-transfer cross sections are calculated by using the optical potential and semiclassical methods in the energy range 10{sup -5}-100 eV/u. For both collision systems, the nonradiative charge-transfer cross sections in the low-energy region show an increasing behavior with decreasing energy. The nonradiative process is the dominant charge-transfer process in the Be{sup 2+}(1s{sup 2})+H(1s) collision in the entire eV and sub-eV energy region. In the B{sup 3+}(1s{sup 2})+H(1s) collision case, however, the cross section for radiative decay to 1 {sup 2{Sigma}+} and 2 {sup 2{Sigma}+} molecular states significantly exceeds that for the nonradiative process for energies below 30 eV/u.

  12. Density matrices of the excited atomic states produced in He{sup 2+} -Na(3s) collisions at 2-50 keV/amu in the coupled-Sturmian-pseudostate approach

    SciTech Connect

    Jain, A.; Winter, T.G.

    1996-05-01

    The authors have determined full density matrices of excited He{sup +} (2 and 3) and Na (3p and 3d) atoms produced in He{sup 2+} - Na(3s) collisions at 2-50 keV/amu. A two-center coupled-Sturmian-pseudostate approach is employed to determine the corresponding amplitudes for the electron transfer and target excitation channels. Various cross sections for charge transfer and target excitation compare very well with experimental data. From the on- and off-diagonal density matrix elements, several physical parameters, corresponding to s-p and p coherences, have been determined and compared with available experimental data and recent theoretical calculations. In particular, the authors have studied the behavior of dipole moment, velocity vector, orientation, and alignment quantities with respect to the projectile velocity and impact parameter.

  13. International Conference on Atomic Physics (12TH) Held at Ann Arbor, Michigan on July 29-August 2, 1990. Abstracts of Contributed Papers.

    DTIC Science & Technology

    1990-09-26

    the flux vanishes. The diffusion equation is justified when the thermalization by Wall collisions drives the atomic velocity distribution to...cavity collisions in which particles can either lose energy or annihilate for a distribution of initial o-Ps energies. We expect such a combination to...shell electrons and a target nucleus due to outer electrons. However, this FP assumption is almost justified in the case of collision system dealt

  14. Collision-energy-resolved Penning ionization electron spectroscopy of p-benzoquinone: Study of electronic structure and anisotropic interaction with He*(2 3S) metastable atoms

    NASA Astrophysics Data System (ADS)

    Kishimoto, Naoki; Okamura, Kohji; Ohno, Koichi

    2004-06-01

    Collision energy dependence of partial ionization cross sections (CEDPICS) of p-benzoquinone with He*(2 3S) metastable atoms indicates that interaction potentials between p-benzoquinone and He*(2 3S) are highly anisotropic in the studied collision energy range (100-250 meV). Attractive interactions were found around the C=O groups for in-plane and out-of-plane directions, while repulsive interactions were found around CH bonds and the benzenoid ring. Assignment of the first four ionic states of p-benzoquinone and an analogous methyl-substituted compound was examined with CEDPICS and anisotropic distributions of the corresponding two nonbonding oxygen orbitals (nO+,nO-) and two πCC orbitals (πCC+,πCC-). An extra band that shows negative CEDPICS was observed at ca. 7.2 eV in Penning ionization electron spectrum.

  15. Rotational excitation of symmetric top molecules by collisions with atoms: Close coupling, coupled states, and effective potential calculations for NH3-He

    NASA Technical Reports Server (NTRS)

    Green, S.

    1976-01-01

    The formalism for describing rotational excitation in collisions between symmetric top rigid rotors and spherical atoms is presented both within the accurate quantum close coupling framework and also the coupled states approximation of McGuire and Kouri and the effective potential approximation of Rabitz. Calculations are reported for thermal energy NH3-He collisions, treating NH3 as a rigid rotor and employing a uniform electron gas (Gordon-Kim) approximation for the intermolecular potential. Coupled states are found to be in nearly quantitative agreement with close coupling results while the effective potential method is found to be at least qualitatively correct. Modifications necessary to treat the inversion motion in NH3 are discussed.

  16. Cross sections for the collisions of metastable Mg*(3P) and Ca*(3P,1D) atoms with HX molecules (X = F, Cl, Br, I)

    NASA Astrophysics Data System (ADS)

    Pranszke, B.; Kierzkowski, P.; Kowalski, A.; Menzinger, M.

    2005-06-01

    Collisions of the metastable Mg*(3P) and Ca*(3P, 1D) atoms with HF, HCl, HBr, and HI molecules have been studied in a beam-gas arrangement. The total collision cross section were determined from the attenuation of spectral lines emitted by the metastables and when possible from the dependence of chemiluminescence intensity on target gas pressure. The total cross sections for Mg*, Ca* + HC1, HBr, and HI are rather large and indicate harpooning mechanism. The Mg* reactions with HX give no electronic chemiluminescence while the Ca* +HX reactions produce electronically excited CaX* radicals for all HX targets studied. For the latter reactions electronic chemiluminescence cross sections and photon yields were determined.

  17. Atomic Collision Theory.

    DTIC Science & Technology

    1981-01-01

    important in the upper atmosphere of the earth and in laser development , respectively. The major thrust of work involved calculations on rotational-vibrational excitation of molecules D2, H2, and HCl.

  18. Physical re-examination of parameters on a molecular collisions-based diffusion model for diffusivity prediction in polymers.

    PubMed

    Ohashi, Hidenori; Tamaki, Takanori; Yamaguchi, Takeo

    2011-12-29

    Molecular collisions, which are the microscopic origin of molecular diffusive motion, are affected by both the molecular surface area and the distance between molecules. Their product can be regarded as the free space around a penetrant molecule defined as the "shell-like free volume" and can be taken as a characteristic of molecular collisions. On the basis of this notion, a new diffusion theory has been developed. The model can predict molecular diffusivity in polymeric systems using only well-defined single-component parameters of molecular volume, molecular surface area, free volume, and pre-exponential factors. By consideration of the physical description of the model, the actual body moved and which neighbor molecules are collided with are the volume and the surface area of the penetrant molecular core. In the present study, a semiempirical quantum chemical calculation was used to calculate both of these parameters. The model and the newly developed parameters offer fairly good predictive ability.

  19. Threshold Laws for Two-Electron Ejection Processes: A Still Controversial Problem in Atomic Physics

    NASA Technical Reports Server (NTRS)

    Temkin, Aaron

    2003-01-01

    This talk deals with collision processes of the following kind: (a) an ionizing collision of an electron with a neutral atom, (b) a photon incident of a negative ion resulting in two-electron ejection. In both cases the final state is a positive ion and two outgoing electrons, and in principle both processes should be governed by the same form of threshold law. It is generally conceded that this is one of the most difficult basic problems in nonrelativistic quantum mechanics. The standard treatment (due to Wannier) will be briefly reviewed in terms of the derivation of his well- known threshold law for the yield (Q) of positive ions vs. the excess energy (E): Q(sub w) varies as E(exp 1.127...). The derivation is a brilliant analysis based on Newton's equations, leading to the dominance of events in which the two electrons emerge on opposite sides of the residual ion with similar energies. In contrast, I will argue on the basis of quantum mechanical ideas that in the threshold limit the more likely outcome are events in which the electrons emerge with decidedly different energies, leading to a formally different (Coulomb-dipole) threshold law Q(sub CD) varies as E(1 + C sin(alpha ln(E)+mu)]/[ln(E)](exp 2). Additional aspects of that approach will be discussed . Some: experimental results will be presented, and more incisive predictions involving polarized projectiles and targets will be given.

  20. Physics and Its Multiple Roles in the International Atomic Energy Agency

    NASA Astrophysics Data System (ADS)

    Massey, Charles D.

    2017-01-01

    The IAEA is the world's centre for cooperation in the nuclear field. It was set up as the world's ``Atoms for Peace'' organization in 1957 within the United Nations family. The Agency works with its Member States and multiple partners worldwide to promote the safe, secure and peaceful use of nuclear technologies. Three main areas of work underpin the IAEA's mission: Safety and Security, Science and Technology, and Safeguards and Verification. To carry out its mission, the Agency is authorized to encourage and assist research on, and development and practical application of, atomic energy for peaceful uses throughout the world; foster the exchange of scientific and technical information on peaceful uses of atomic energy; and encourage the exchange of training of scientists and experts in the field of peaceful uses of atomic energy. Nowadays, nuclear physics and nuclear technology are applied in a great variety of social areas, such as power production, medical diagnosis and therapies, environmental protection, security control, material tests, food processing, waste treatments, agriculture and artifacts analysis. This presentation will cover the role and practical application of physics at the IAEA, and, in particular, focus on the role physics has, and will play, in nuclear security.

  1. PREFACE: Atomically controlled fabrication technology: new physics and functional device realization Atomically controlled fabrication technology: new physics and functional device realization

    NASA Astrophysics Data System (ADS)

    Kuwahara, Yuji; Kasai, Hideaki

    2011-10-01

    To realize next generation functional devices, atomic level controllability of the application and fabrication techniques is necessary. The conventional route to advance solid state devices, which involves improvement of 'instrumental accuracy', is now facing a major paradigm shift towards 'phenomenal accuracy'. Therefore, to keep up with this critical turn in the development of devices, pioneering research (both theoretical and experimental) on relevant materials, focusing on new physics at the atomic scale, is inevitable. This special section contains articles on the advancements in fabrication of functional devices with an emphasis on the exploration, clarification and understanding of atomistic phenomena. Research articles reporting theoretical and experimental findings on various materials such as semiconductors, metals, magnetic and organic systems, collectively present and 'capture' the appropriate processes and mechanisms of this rapidly developing field. The theoretical investigations employ first-principles quantum-mechanical simulations to clarify and bring about design principles and guidelines, or to develop more reliable computational methods. Experimental studies, on the other hand, introduce novel capabilities to build, view and manipulate materials at the atomic scale by employing pioneering techniques. Thus, the section pays significant attention to novel structures and properties and the accompanying fabrication techniques and design arising from the understanding of properties and structures at the atomic scale. We hope that researchers in the area of physics, materials science and engineering, interested in the development of functional devices via atomic level control, will find valuable information in this collaborative work. We are grateful to all of the authors for their contributions. Atomically controlled fabrication contents On the mechanism of carbon nanotube formation: the role of the catalyst G N Ayre, T Uchino, B Mazumder, A L Hector

  2. HARD PARTON PHYSICS IN HIGH ENERGY NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 17

    SciTech Connect

    CARROLL,J.

    1999-09-10

    The RIKEN-BNL center workshop on ''Hard parton physics in high energy nuclear collisions'' was held at BNL from March 1st-5th! 1999. The focus of the workshop was on hard probes of nucleus-nucleus collisions that will be measured at RHIC with the PHENIX and STAR detectors. There were about 45 speakers and over 70 registered participants at the workshop, with roughly a quarter of the speakers from overseas. About 60% of the talks were theory talks. A nice overview of theory for RHIC was provided by George Sterman. The theoretical talks were on a wide range of topics in QCD which can be classified under the following: (a) energy loss and the Landau-Pomeranchuk-Migdal effect; (b) minijet production and equilibration; (c) small x physics and initial conditions; (d) nuclear parton distributions and shadowing; (e) spin physics; (f) photon, di-lepton, and charm production; and (g) hadronization, and simulations of high pt physics in event generators. Several of the experimental talks discussed the capabilities of the PHENIX and STAR detectors at RHIC in measuring high pt particles in heavy ion collisions. In general, these talks were included in the relevant theory sessions. A session was set aside to discuss the spin program at RHIC with polarized proton beams. In addition, there were speakers from 08, HERA, the fixed target experiments at Fermilab, and the CERN fixed target Pb+Pb program, who provided additional perspective on a range of issues of relevance to RHIC; from jets at the Tevatron, to saturation of parton distributions at HERA, and recent puzzling data on direct photon production in fixed target experiments, among others.

  3. The Advanced Light Source: A new tool for research in atomic and molecular physics

    NASA Astrophysics Data System (ADS)

    Schlachter, F.; Robinson, A.

    1991-04-01

    The Advanced Light Source at the Lawrence Berkeley Laboratory will be the world's brightest synchrotron radiation source in the extreme ultraviolet and soft x-ray regions of the spectrum when it begins operation in 1993. It will be available as a national user facility to researchers in a broad range of disciplines, including materials science, atomic and molecular physics, chemistry, biology, imaging, and technology. The high brightness of the ALS will be particularly well suited to high-resolution studies of tenuous targets, such as excited atoms, ions, and clusters.

  4. The Physics of Miniature Atomic Clocks: 0-0 Versus "End" Transitions

    NASA Astrophysics Data System (ADS)

    Post, Amber; Jau, Yuan-Yu; Kuzma, Nicholas; Happer, William

    2003-05-01

    The majority of traditional atomic-clock designs are based on the 0-0 hyperfine transition of a Cs 133 atom. We are currently investigating the advantages of operating a miniature optical atomic clock using the "end" transitions, e.g. connecting states |f=1, mf =+/-1> and |f=2, mf=+/-2> in 87Rb. In our paper we present extensive new measurements of relevant relaxation rates, such as those due to spin-exchange collisions, buffer-gas pressure shifts, Carver Rates and others, which ultimately determine the choices of an operating regime for the miniature optical atomic clock. The relationship between these rates is non-trivial: for example, using higher laser power will increase polarization and reduce the spin-exchange rate [1], but it can simultaneously increase the linewidth due to the optical pumping rate. The dependence of these and other relaxation rates on the cell size, temperature, pressure, a choice of buffer gas, and other parameters will be reported. Based on these measured rates, our modeling can be used to predict the transition linewidths, signal-to-noise ratios and thus the stability of the clock in different operating regimes. The trade-off between the stability of the clock and the desired small cell size and low power consumption needs to be carefully considered in order to optimize our design. In our experiments we used optical, microwave, and radio-frequency excitation to study hyperfine and Zeeman resonance lines in heated glass cells containing pure-isotope alkali-metal vapor and buffer gasses (N2, Ar, He, etc.) at low (0 - 10 G) magnetic fields. Simultaneous use of light, microwave and radio-frequency fields allowed us to calibrate surrounding magnetic fields by observing the corresponding shifts of the resonance, thus leading us to a quantitative understanding of our system. [1] S. Appelt, A. B. Baranga, A. R. Young, W. Happer, Phys. Rev. A 59, 2078 (1999).

  5. International Symposium on Correlation and Polarization in Electron-Atom Collisions Held in Pasadena, California on 1-2 August 1985.

    DTIC Science & Technology

    1985-08-02

    Collisions With Heavy Atoms 12:15 - 1:30 LUNCH 1:30 - 2:10 p.m. 0. Berger, University of Munster ’Elastic Scattering of Polarized Electrons From Mercury ...scattering of electrons from Hg and Pb. /I/ G.F. Hanne, Comments At. Mol. Phys. 14 (1983) 163 4 ELASTIC SCATTERING OF POLARISED ELECTRONS FROM MERCURY ...parameters S, T and U has been measured at various fixed Lnergies between 25 eV and 350 eV for mercury and xenon. The polarised electrons are produced

  6. Electronic and Atomic Collisions. Abstracts of Contributed Papers. International Conference on the Physics of Electronic and atomic Collisions (14th) Held at Palo Alto, California in 1985,

    DTIC Science & Technology

    1985-01-01

    Neon 2p-Satellites 13 U. Becker, R. Hoizel, H. G. Kerkhoff. B. Langer, D. Szostak, R. Wehlitz Single and Double Photoionization of Alkaline- Earth ...The Photoelectron Spectrum of NaBr- 52 Thomas M. Miller, Kermit K. Murray, W. Carl Lineherger ix 0N Field and Photodetachment of Water Clusters 53 H...and the rare earth elements where this showing the strength of configuration interaction in Ba orbital is highly contracted. This outstanding position

  7. Unveiling the structural arrangements responsible for the atomic dynamics in metallic glasses during physical aging

    PubMed Central

    Giordano, V. M.; Ruta, B

    2016-01-01

    Understanding and controlling physical aging, that is, the spontaneous temporal evolution of out-of-equilibrium systems, represents one of the greatest tasks in material science. Recent studies have revealed the existence of a complex atomic motion in metallic glasses, with different aging regimes in contrast with the typical continuous aging observed in macroscopic quantities. By combining dynamical and structural synchrotron techniques, here for the first time we directly connect previously identified microscopic structural mechanisms with the peculiar atomic motion, providing a broader unique view of their complexity. We show that the atomic scale is dominated by the interplay between two processes: rearrangements releasing residual stresses related to a cascade mechanism of relaxation, and medium range ordering processes, which do not affect the local density, likely due to localized relaxations of liquid-like regions. As temperature increases, a surprising additional secondary relaxation process sets in, together with a faster medium range ordering, likely precursors of crystallization. PMID:26787443

  8. Atomic Physics Effects on Convergent, Child-Langmuir Ion Flow between Nearly Transparent Electrodes

    SciTech Connect

    Santarius, John F.; Emmert, Gilbert A.

    2013-11-07

    Research during this project at the University of Wisconsin Fusion Technology Institute (UW FTI) on ion and neutral flow through an arbitrary, monotonic potential difference created by nearly transparent electrodes accomplished the following: (1) developed and implemented an integral equation approach for atomic physics effects in helium plasmas; (2) extended the analysis to coupled integral equations that treat atomic and molecular deuterium ions and neutrals; (3) implemented the key deuterium and helium atomic and molecular cross sections; (4) added negative ion production and related cross sections; and (5) benchmarked the code against experimental results. The analysis and codes treat the species D0, D20, D+, D2+, D3+, D and, separately at present, He0 and He+. Extensions enhanced the analysis and related computer codes to include He++ ions plus planar and cylindrical geometries.

  9. The Physics of Protoplanetesimal Dust Agglomerates. VIII. Microgravity Collisions between Porous SiO_2 Aggregates and Loosely Bound Agglomerates

    NASA Astrophysics Data System (ADS)

    Whizin, Akbar D.; Blum, Jürgen; Colwell, Joshua E.

    2017-02-01

    We performed laboratory experiments colliding 0.8–1.0 mm and 1.0–1.6 mm SiO2 dust aggregates with loosely bound centimeter-sized agglomerates of those aggregates in microgravity. This work builds on previous microgravity laboratory experiments examining the collisional properties of porous loosely bound dust aggregates. In centimeter-sized aggregates, surface forces dominate self-gravity and may play a large role in aggregate growth beyond this size range. We characterize the properties of protoplanetary aggregate analogs to help place constraints on initial formation mechanisms and environments. We determined several important physical characteristics of these aggregates in a large number of low-velocity collisions. We observed low coefficients of restitution and fragmentation thresholds near 1 m s‑1 for 1–2 cm agglomerates, which are in good agreement with previous findings in the literature. We find the accretion efficiency for agglomerates of loosely bound aggregates to be higher than that for just aggregates themselves. We find sticking thresholds of 6.6 ± 2 cm s‑1, somewhat higher than those in similar studies, which have observed few aggregates stick at speeds of under 3 cm s‑1. Even with highly dissipative collisions, loosely bound agglomerates have difficulty accreting beyond centimeter-sized bodies at typical collision speeds in the disk. Our results indicate agglomerates of porous aggregates have slightly higher sticking thresholds than previously thought, allowing possible growth to decimeter-sized bodies if velocities are low enough.

  10. Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source

    SciTech Connect

    Jones, K.W.; Johnson, B.M.; Meron, M.

    1986-01-01

    An Atomic Physics Facility (APF) for experiments that will use radiation from a superconducting wiggler on the NSLS X-13 port is described. The scientific justification for the APF is given and the elements of the facility are discussed. It is shown that it will be possible to conduct a uniquely varied set of experiments that can probe most aspects of atomic physics. A major component of the proposal is a heavy-ion storage ring capable of containing ions with energies of about 10 MeV/nucleon. The ring can be filled with heavy ions produced at the BNL MP Tandem Laboratory or from independent ion-source systems. A preliminary cost estimate for the facility is presented.

  11. Construction and characterization of external cavity diode lasers for atomic physics.

    PubMed

    Hardman, Kyle S; Bennetts, Shayne; Debs, John E; Kuhn, Carlos C N; McDonald, Gordon D; Robins, Nick

    2014-04-24

    Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and Titanium Sapphire lasers as the workhorse laser of atomic physics labs. Their versatility and prolific use throughout atomic physics in applications such as absorption spectroscopy and laser cooling makes it imperative for incoming students to gain a firm practical understanding of these lasers. This publication builds upon the seminal work by Wieman, updating components, and providing a video tutorial. The setup, frequency locking and performance characterization of an ECDL will be described. Discussion of component selection and proper mounting of both diodes and gratings, the factors affecting mode selection within the cavity, proper alignment for optimal external feedback, optics setup for coarse and fine frequency sensitive measurements, a brief overview of laser locking techniques, and laser linewidth measurements are included.

  12. Construction and Characterization of External Cavity Diode Lasers for Atomic Physics

    PubMed Central

    Hardman, Kyle S.; Bennetts, Shayne; Debs, John E.; Kuhn, Carlos C. N.; McDonald, Gordon D.; Robins, Nick

    2014-01-01

    Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and Titanium Sapphire lasers as the workhorse laser of atomic physics labs1,2. Their versatility and prolific use throughout atomic physics in applications such as absorption spectroscopy and laser cooling1,2 makes it imperative for incoming students to gain a firm practical understanding of these lasers. This publication builds upon the seminal work by Wieman3, updating components, and providing a video tutorial. The setup, frequency locking and performance characterization of an ECDL will be described. Discussion of component selection and proper mounting of both diodes and gratings, the factors affecting mode selection within the cavity, proper alignment for optimal external feedback, optics setup for coarse and fine frequency sensitive measurements, a brief overview of laser locking techniques, and laser linewidth measurements are included. PMID:24796259

  13. Quasi-Classical Trajectory Study of Atom-Diatomic Molecule Collisions in Symmetric Hyperspherical Coordinates: The F + HCl Reaction as a Test Case.

    PubMed

    Freixas-Lemus, Victor Manuel; Martínez-Mesa, Aliezer; Uranga-Piña, Llinersy

    2016-04-07

    We investigate the reactive dynamics of the triatomic system F + HCl → HF + Cl for total angular momentum equal zero and for different low-lying rovibrational states of the diatomic molecule. For each of the initial vibrational quantum numbers, the time evolution of the atom-diatom collision process is investigated for a wide range of impact angles and collision energies. To this purpose, the Quasi-Classical Trajectories (QCT) method was implemented in a hyperspherical configuration space. The Hamilton equations of motion are solved numerically in an intermediate effective Cartesian space to exploit the relative simplicity of this intermediate representation. Interatomic interactions are described by a London-Eyring-Polanyi-Sato potential energy surface, specifically developed for the title reaction, and the results of the QCT simulations are discussed in terms of the time-evolution of the hyperangles. The analysis of the collision dynamics using symmetric hyperspherical coordinates provides, in addition to the description in terms of a natural reaction coordinate (the hyperradius), a more striking representation of the exchange dynamics, in terms of the time-dependent probability distribution along the kinematic rotation hyperangle, and a precise distinction between direct and indirect mechanisms of the reaction.

  14. From the Dawn of Nuclear Physics to the First Atomic Bombs

    NASA Astrophysics Data System (ADS)

    Woolbright, Stephen; Schumacher, Jacob; Michonova-Alexova, Ekaterina

    2014-03-01

    This work gives a fresh look at the major discoveries leading to nuclear fission within the historical perspective. The focus is on the main contributors to the discoveries in nuclear physics, leading to the idea of fission and its application to the creation of the atomic bombs used at the end of the World War II. The present work is a more complete review on the history of the nuclear physics discoveries and their application to the atomic bomb. In addition to the traditional approach to the topic, focusing mainly on the fundamental physics discoveries in Europe and on the Manhattan Project in the United States, the nuclear research in Japan is also emphasized. Along with that, a review of the existing credible scholar publications, providing evidence for possible atomic bomb research in Japan, is provided. Proper credit is given to the women physicists, whose contributions had not always been recognized. Considering the historical and political situation at the time of the scientific discoveries, thought-provoking questions about decision-making, morality, and responsibility are also addressed. The work refers to the contributions of over 20 Nobel Prize winners. EM-A is grateful to Prof. Walter Grunden and to Prof. Emeritus Shadahiko Kano, Prof. Emeritus Monitori Hoshi for sharing their own notes, documents, and references, and to CCCU for sponsoring her participation in the 2013 Nuclear Weapons Seminar in Japan.

  15. Many-electron aspects of molecular promotion in ion-atom collisions - Production of core-excited states of Li in Li/+/-He collisions

    NASA Technical Reports Server (NTRS)

    Elston, S. B.; Vane, C. R.; Schumann, S.

    1979-01-01

    Production of core-excited autoionizing states of neutral Li having configurations of the form 1snln(prime)l(prime) has been observed over the impact-energy range from 10-50 keV. Although the results for production of all such states is remarkably consistent with a quasi-molecular-excitation model proposed by Stolterfoht and Leithaeuser (1976), production of individual lines in the observed spectra exhibits collision-velocity dependencies indicative of considerably more complex processes, including processes which appear to be inherently two-electron in nature. Excitation functions are presented for (1s2s/2/)/2/S, 1s(2s2p/3/P)/2/P, 1s(2s2p/1/P)/2/P, and (1s2p/2/)/2/D core-excited state of Li and for total core excitation.

  16. Quantum-mechanical calculation of three-dimensional atom-diatom collisions in the presence of intense laser radiation

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1979-01-01

    A formalism is presented for describing the collision of fluorine with the hydrogen molecule in the presence of intense radiation. For a laser frequency on the order of the spin-orbit splitting of fluorine, the interaction of the molecular system with the radiation occurs at relatively long range where, for this system, the electric dipole is vanishingly small. Hence the interaction occurs due to the magnetic dipole coupling. Even so, at low collision energies a substantial enhancement of the quenching cross section is found for a radiation intensity of 10 to the 11th W/sq cm.

  17. Laser-Induced Optical Pumping Measurements of Cross Section for Fine- and Hyperfine-Structure Transitions in Sodium Induced by Collisions with Helium and Argon Atoms

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.; Sung, C. C.

    1999-01-01

    Optical pumping of the ground states of sodium can radically alter the shape of the laser-induced fluorescence excitation spectrum, complicating measurements of temperature, pressure, etc., which are based on these spectra. Modeling of the fluorescence using rate equations for the eight hyperfine states of the sodium D manifolds can be used to quantify the contribution to the ground state pumping of transitions among the hyperfine excited states induced by collisions with buffer gas atoms. This model is used here to determine, from the shape of experimental spectra, cross sections lor DELTA.F transitions of the P(sub 3/2) state induced by collisions with helium and argon atoms, for a range of values assumed for the P(sub 1/2), DELTA.F cross sections. The hyperfine cross sections measured using this method, which to our knowledge is novel, are compared with cross sections for transitions involving polarized magnetic substates m(sub F) measured previously using polarization sensitive absorption. Also, fine-structure transition cross sections were measured in the pumped vapor, giving agreement with previous measurements made in the absence of pumping.

  18. Laser Induced Optical Pumping Measurements of Cross Sections for Fine and Hyperfine Structure Transitions in Sodium Induced by Collisions with Helium Argon Atoms

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.; Sung, C. C.

    1998-01-01

    Optical pumping of the ground states of sodium can radically alter the shape of the laser induced fluorescence excitation spectrum, complicating measurements of temperature, pressure, etc., which are based on these spectra. Modeling of the fluorescence using rate equations for the eight hyperfine states of the sodium D manifolds can be used to quantify the contribution to the ground state pumping of transitions among the hyperfine excited states induced by collisions with buffer gas atoms. This model is used here to determine, from the shape of experimental spectra, cross sections for (Delta)F transitions of the P(sub 3/2) state induced by collisions with helium and argon atoms, for a range of values assumed for the P(sub 1/2), (Delta)F cross sections. The hyperfine cross sections measured using this method, which is thought to be novel, are compared with cross sections for transitions involving polarized magnetic substates, m(sub F), measured previously using polarization sensitive absorption. Also, fine structure transition ((Delta)J) cross sections were measured in the pumped vapor, giving agreement with previous measurements made in the absence of pumping.

  19. Collisions of electrons with hydrogen atoms II. Low-energy program using the method of the exterior complex scaling

    NASA Astrophysics Data System (ADS)

    Benda, Jakub; Houfek, Karel

    2014-11-01

    While collisions of electrons with hydrogen atoms pose a well studied and in some sense closed problem, there is still no free computer code ready for “production use”, that would enable applied researchers to generate necessary data for arbitrary impact energies and scattering transitions directly if absent in on-line scattering databases. This is the second article on the Hex program package, which describes a new computer code that is, with a little setup, capable of solving the scattering equations for energies ranging from a fraction of the ionization threshold to approximately 100 eV or more, depending on the available computational resources. The program implements the exterior complex scaling method in the B-spline basis. Catalogue identifier: AETI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETI_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 44 440 No. of bytes in distributed program, including test data, etc.: 322 643 Distribution format: tar.gz Programming language: C++11. Computer: Any. Operating system: Any system with a C++11 compiler (e.g. GCC 4.8.1; tested on OpenSUSE 13.1 and Windows 8). Has the code been vectorized or parallelized?: Parallelized by OpenMP and MPI. RAM: Depending on input; 4.9 GiB for the test run. Classification: 2.4. External routines: GSL [1], HDF5 [2], UMFPACK [3], FFTW3 [4], optionally with OpenBLAS [5]. Nature of problem: Solution of the two-particle Schrödinger equation in central field. Solution method: The two-electron states are expanded into angular momentum eigenstates, which gives rise to the coupled bi-radial equations. The bi-radially dependent solution is then represented in a B-spline basis, which transforms the set of equations into a large matrix equation in this basis. The boundary condition

  20. Medical physics in Europe following recommendations of the International Atomic Energy Agency

    PubMed Central

    Lopes, Maria do Carmo; Drljević, Advan; Gershkevitsh, Eduard; Pesznyak, Csilla

    2016-01-01

    Background Medical physics is a health profession where principles of applied physics are mostly directed towards the application of ionizing radiation in medicine. The key role of the medical physics expert in safe and effective use of ionizing radiation in medicine was widely recognized in recent European reference documents like the European Union Council Directive 2013/59/EURATOM (2014), and European Commission Radiation Protection No. 174, European Guidelines on Medical Physics Expert (2014). Also the International Atomic Energy Agency (IAEA) has been outspoken in supporting and fostering the status of medical physics in radiation medicine through multiple initiatives as technical and cooperation projects and important documents like IAEA Human Health Series No. 25, Roles and Responsibilities, and Education and Training Requirements for Clinically Qualified Medical Physicists (2013) and the International Basic Safety Standards, General Safety Requirements Part 3 (2014). The significance of these documents and the recognition of the present insufficient fulfilment of the requirements and recommendations in many European countries have led the IAEA to organize in 2015 the Regional Meeting on Medical Physics in Europe, where major issues in medical physics in Europe were discussed. Most important outcomes of the meeting were the recommendations addressed to European member states and the survey on medical physics status in Europe conducted by the IAEA and European Federation of Organizations for Medical Physics. Conclusions Published recommendations of IAEA Regional Meeting on Medical Physics in Europe shall be followed and enforced in all European states. Appropriate qualification framework including education, clinical specialization, certification and registration of medical physicists shall be established and international recommendation regarding staffing levels in the field of medical physics shall be fulfilled in particular. European states have clear

  1. Experimental Highlights: Heavy Quark Physics in Heavy-Ion Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Nouicer, Rachid

    2017-03-01

    The discovery at RHIC of large high-pT suppression and flow of electrons from heavy quarks flavors have altered our view of the hot and dense matter formed in central Au + Au collisions at √sNN = 200 GeV. These results suggest a large energy loss and flow of heavy quarks in the hot, dense matter. In recent years, the RHIC experiments upgraded the detectors; (1) PHENIX Collaboration installed silicon vertex tracker (VTX) at midrapidity region and forward silicon vertex tracker (FVTX) at the forward rapidity region, and (2) STAR Collaboration installed the heavy flavor tracker (HFT) and the muon telescope detector (MTD) both at the mid-rapidity region. The PHENIX experiments established measurements of ψ (1S ) and ψ (2S ) production as a function of system size, p + p, p + Al, p + Au, and 3He + Au collisions at √sNN = 200 GeV. In p/3He + A collisions at forward rapidity, we observe no difference in the ψ (2S )/ψ (1S ) ratio relative to p + p collisions. At backward rapidity, where the comoving particle density is higher, we find that the ψ (2S ) is preferentially suppressed by a factor of two. STAR Collaboration presents the first J/ ψ measurements in the di-muon decay channel in Au + Au at √sNN = 200 GeV at mid-rapidity. We observe a clear J/ψ RAA suppression and qualitatively well described by transport models, including dissociation and regeneration simultaneously.

  2. Phases and Interfaces from Real Space Atomically Resolved Data: Physics-Based Deep Data Image Analysis.

    PubMed

    Vasudevan, Rama K; Ziatdinov, Maxim; Jesse, Stephen; Kalinin, Sergei V

    2016-09-14

    Advances in electron and scanning probe microscopies have led to a wealth of atomically resolved structural and electronic data, often with ∼1-10 pm precision. However, knowledge generation from such data requires the development of a physics-based robust framework to link the observed structures to macroscopic chemical and physical descriptors, including single phase regions, order parameter fields, interfaces, and structural and topological defects. Here, we develop an approach based on a synergy of sliding window Fourier transform to capture the local analog of traditional structure factors combined with blind linear unmixing of the resultant 4D data set. This deep data analysis is ideally matched to the underlying physics of the problem and allows reconstruction of the a priori unknown structure factors of individual components and their spatial localization. We demonstrate the principles of this approach using a synthetic data set and further apply it for extracting chemical and physically relevant information from electron and scanning tunneling microscopy data. This method promises to dramatically speed up crystallographic analysis in atomically resolved data, paving the road toward automatic local structure-property determinations in crystalline and quasi-ordered systems, as well as systems with competing structural and electronic order parameters.

  3. Phases and interfaces from real space atomically resolved data: Physics-based deep data image analysis

    DOE PAGES

    Vasudevan, Rama K.; Ziatdinov, Maxim; Jesse, Stephen; ...

    2016-08-12

    Advances in electron and scanning probe microscopies have led to a wealth of atomically resolved structural and electronic data, often with ~1–10 pm precision. However, knowledge generation from such data requires the development of a physics-based robust framework to link the observed structures to macroscopic chemical and physical descriptors, including single phase regions, order parameter fields, interfaces, and structural and topological defects. Here, we develop an approach based on a synergy of sliding window Fourier transform to capture the local analog of traditional structure factors combined with blind linear unmixing of the resultant 4D data set. This deep data analysismore » is ideally matched to the underlying physics of the problem and allows reconstruction of the a priori unknown structure factors of individual components and their spatial localization. We demonstrate the principles of this approach using a synthetic data set and further apply it for extracting chemical and physically relevant information from electron and scanning tunneling microscopy data. Furthermore, this method promises to dramatically speed up crystallographic analysis in atomically resolved data, paving the road toward automatic local structure–property determinations in crystalline and quasi-ordered systems, as well as systems with competing structural and electronic order parameters.« less

  4. Phases and interfaces from real space atomically resolved data: Physics-based deep data image analysis

    SciTech Connect

    Vasudevan, Rama K.; Ziatdinov, Maxim; Jesse, Stephen; Kalinin, Sergei V.

    2016-08-12

    Advances in electron and scanning probe microscopies have led to a wealth of atomically resolved structural and electronic data, often with ~1–10 pm precision. However, knowledge generation from such data requires the development of a physics-based robust framework to link the observed structures to macroscopic chemical and physical descriptors, including single phase regions, order parameter fields, interfaces, and structural and topological defects. Here, we develop an approach based on a synergy of sliding window Fourier transform to capture the local analog of traditional structure factors combined with blind linear unmixing of the resultant 4D data set. This deep data analysis is ideally matched to the underlying physics of the problem and allows reconstruction of the a priori unknown structure factors of individual components and their spatial localization. We demonstrate the principles of this approach using a synthetic data set and further apply it for extracting chemical and physically relevant information from electron and scanning tunneling microscopy data. Furthermore, this method promises to dramatically speed up crystallographic analysis in atomically resolved data, paving the road toward automatic local structure–property determinations in crystalline and quasi-ordered systems, as well as systems with competing structural and electronic order parameters.

  5. Quantum-mechanical transport equation for atomic systems.

    NASA Technical Reports Server (NTRS)

    Berman, P. R.

    1972-01-01

    A quantum-mechanical transport equation (QMTE) is derived which should be applicable to a wide range of problems involving the interaction of radiation with atoms or molecules which are also subject to collisions with perturber atoms. The equation follows the time evolution of the macroscopic atomic density matrix elements of atoms located at classical position R and moving with classical velocity v. It is quantum mechanical in the sense that all collision kernels or rates which appear have been obtained from a quantum-mechanical theory and, as such, properly take into account the energy-level variations and velocity changes of the active (emitting or absorbing) atom produced in collisions with perturber atoms. The present formulation is better suited to problems involving high-intensity external fields, such as those encountered in laser physics.

  6. Stalking the Anti-Racist Atom: Engaging Educational Equity and Diversity in Physics Teaching

    NASA Astrophysics Data System (ADS)

    Hodari, Apriel K.

    2006-12-01

    One of the first articles I ever read on diversity in physics education stated, “There’s no such thing as an anti-racist atom.” This perspective, that the science of physics is itself inherently unbiased, illustrates the difficulty of engaging our intellectual community on this topic. We genuinely believe that our science is devoid of the complications of the human condition, and therefore we need not worry about these things. It is clear however, as people competing for scarce resources in a non-equitable society, we engage in all of the same behaviors everyone else does, include those that work against equity and diversity. Over the last several years, my colleagues and I have held workshops aimed at addressing educational equity and diversity in physics teaching. In this discussion, I will present some of the questions we have posed, along with lessons learned and ideas about what we can do next.

  7. Optical and magnetic properties of a transparent garnet film for atomic physics experiments

    NASA Astrophysics Data System (ADS)

    Saito, Mari; Tajima, Ryoichi; Kiyosawa, Ryota; Nagata, Yugo; Shimada, Hiroyuki; Ishibashi, Takayuki; Hatakeyama, Atsushi

    2016-12-01

    We investigated the optical and magnetic properties of a transparent magnetic garnet with a particular focus on its applications to atomic physics experiments. The garnet film used in this study was a magnetically soft material that was originally designed for a Faraday rotator at optical communication wavelengths in the near infrared region. The film had a thickness of 2.1 μm and a small optical loss at a wavelength of λ =780 nm resonant with Rb atoms. The Faraday effect was also small and, thus, barely affected the polarization of light at λ =780 nm. In contrast, large Faraday rotation angles at shorter wavelengths enabled us to visualize magnetic domains, which were perpendicularly magnetized in alternate directions with a period of 3.6 μm. We confirmed the generation of an evanescent wave on the garnet film, which can be used for the optical observation and manipulation of atoms on the surface of the film. Finally, we demonstrated a magnetic mirror for laser-cooled Rb atoms using the garnet film.

  8. Resolving all-order method convergence problems for atomic physics applications

    SciTech Connect

    Gharibnejad, H.; Derevianko, A.; Eliav, E.; Safronova, M. S.

    2011-05-15

    The development of the relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function are included to all orders of perturbation theory led to many important results for the study of fundamental symmetries, development of atomic clocks, ultracold atom physics, and others, as well as provided recommended values of many atomic properties critically evaluated for their accuracy for a large number of monovalent systems. This approach requires iterative solutions of the linearized coupled-cluster equations leading to convergence issues in some cases where correlation corrections are particularly large or lead to an oscillating pattern. Moreover, these issues also lead to similar problems in the configuration-interaction (CI)+all-order method for many-particle systems. In this work, we have resolved most of the known convergence problems by applying two different convergence stabilizer methods, namely, reduced linear equation and direct inversion of iterative subspace. Examples are presented for B, Al, Zn{sup +}, and Yb{sup +}. Solving these convergence problems greatly expands the number of atomic species that can be treated with the all-order methods and is anticipated to facilitate many interesting future applications.

  9. Dips in spectral line profiles and their applications in plasma physics and atomic physics

    NASA Astrophysics Data System (ADS)

    Dalimier, E.; Oks, E.; Renner, O.

    2017-03-01

    We review studies of two kinds of dips in spectral line profiles emitted by plasmas - the dips that have been predicted theoretically and observed experimentally: Langmuir-wave-caused dips (L-dips) and charge-exchange-caused dips (X-dips). There is a principal difference with respect to positions of L-dips and X-dips relative to the unperturbed wavelength of a spectral line: positions of L-dips scale with the electron density Ne roughly as Ne1/2, while positions of X-dips are almost independent of Ne (the dependence is much weaker than for L-dips). L-dips and X-dips phenomena are important both fundamentally and practically. The fundamental importance is due to a rich physics behind each of these phenomena. As for important practical applications, they are as follows. Observations of L-dips constitute a very accurate method to measure the electron density in plasmas - the method that does not require the knowledge of the electron temperature. L-dips also allow measuring the amplitude of the electric field of Langmuir waves - the only one spectroscopic method available for this purpose. Observations of X-dips provide an opportunity to determine rate coefficient of charge exchange between multi-charged ions. This is an important reference data virtually inaccessible by other experimental methods. The rate coefficients of charge exchange are important for magnetic fusion in Tokamaks, for population inversion in the soft x-ray and VUV ranges, for ion storage devices, as well as for astrophysics (e.g., for the solar plasma and for determining the physical state of planetary nebulae).

  10. TRIμP-Trapped Radioactive Atoms-μicrolaboratories for Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Jungmann, K.; Berg, G. P.; Dammalapati, U.; Dendooven, P.; Dermois, O.; Harakeh, M. N.; Hoekstra, R.; Morgenstern, R.; Rogachevskiy, A.; Sanchez-Vega, M.; Timmermans, R.; Traykov, E.; Willmann, L.; Wilscut, H. W.

    At the Kernfysisch Versneller Instituut (KVI) in Groningen, NL, a new facility (TRIμP) is under development. Radioactive nuclei will be produced using heavy ion beams from the superconducting AGOR cyclotron. They are then slowed down and finally trapped in ion or atomic traps in order to perform precision experiments with them. The facility will be open for use by the worldwide community. The present local research programme includes precision studies of nuclear β-decays through β-neutrino (recoil nucleus) momentum correlations in weak decays as well as searches for permanent electric dipole moments in heavy atomic systems. Such experiments offer a large potential for discovering new physics or to put sensitive limits on parameters in models beyond standard theory.

  11. An open source digital servo for atomic, molecular, and optical physics experiments

    PubMed Central

    Leibrandt, D. R.; Heidecker, J.

    2016-01-01

    We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27Al+ in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser. PMID:26724014

  12. An open source digital servo for atomic, molecular, and optical physics experiments

    SciTech Connect

    Leibrandt, D. R. Heidecker, J.

    2015-12-15

    We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of {sup 27}Al{sup +} in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

  13. Testing for a cosmological influence on local physics using atomic and gravitational clocks

    NASA Technical Reports Server (NTRS)

    Adams, P. J.; Hellings, R. W.; Canuto, V. M.; Goldman, I.

    1983-01-01

    The existence of a possible influence of the large-scale structure of the universe on local physics is discussed. A particular realization of such an influence is discussed in terms of the behavior in time of atomic and gravitational clocks. Two natural categories of metric theories embodying a cosmic infuence exist. The first category has geodesic equations of motion in atomic units, while the second category has geodesic equations of motion in gravitational units. Equations of motion for test bodies are derived for both categories of theories in the appropriate parametrized post-Newtonian limit and are applied to the Solar System. Ranging data to the Viking lander on Mars are of sufficient precision to reveal (1) if such a cosmological influence exists at the level of Hubble's constant, and (2) which category of theories is appropriate for a descripton of the phenomenon.

  14. Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

    ERIC Educational Resources Information Center

    Hoffman, Gary G.

    2015-01-01

    A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

  15. The physics of grain-grain collisions and gas-grain sputtering in interstellar shocks

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.; Mckee, C. F.; Seab, C. G.; Hollenbach, D. J.

    1994-01-01

    Grain-grain collisions and ion sputtering destroy dust grains in interstellar shocks. An analytical theory is developed for the propagation of shock waves in solids driven by grain-grain collisions, which compares very favorably with detailed numerical calculations. This theory is used to determine the fraction of grain vaporized by a grain-grain collision. Our results predict much less vaporization of colliding grains in interstellar shocks than previous estimates. This theory can also be used to determine the fraction of a colliding grain that melts, shatter, or undergoes a phase transformation to a higher density phase. In particular, the latter two processes can be much more important in interstellar shocks than vaporization. The sputtering of grains by impacting gas ions is reanalyzed based upon extensive laboratory studies and a theoretically derived 'universal'sputtering relation. The analytical results are compared to available experimental studies of sputtering of graphite/amorphous carbon, SiO2, SiC, Fe, and H2O. Sputtering yields for astrophysically relevant materials as a function of impact energy and ion mass are derived. These yields are also averaged over thermal impact spectrum and simple polynomial fits to the resulting yields as a function of temperature are presented. The derived sputtering yields are similar to those adopted in previous studies, except for graphite near threshold where the new yields are much larger due to a lower adopted binding energy. The ion bombardment will amorphitize the surface layers of interstellar grains. It will also convert graphite into hydrogenated amorphous carbon (HAC) to a depth of 10-20 A. It is suggested that these HAC surfaces are the carriers of the 3.4 micrometer absorption feature in the interstellar medium.

  16. Low-energy inelastic collisions of OH radicals with He atoms and D{sub 2} molecules

    SciTech Connect

    Kirste, Moritz; Scharfenberg, Ludwig; Meijer, Gerard; Meerakker, Sebastiaan Y. T. van de; Klos, Jacek; Lique, Francois; Alexander, Millard H.

    2010-10-15

    We present an experimental study on the rotational inelastic scattering of OH (X {sup 2}{Pi}{sub 3/2},J=3/2,f) radicals with He and D{sub 2} at collision energies between 100 and 500 cm{sup -1} in a crossed beam experiment. The OH radicals are state selected and velocity tuned using a Stark decelerator. Relative parity-resolved state-to-state inelastic scattering cross sections are accurately determined. These experiments complement recent low-energy collision studies between trapped OH radicals and beams of He and D{sub 2} that are sensitive to the total (elastic and inelastic) cross sections [Sawyer et al., Phys. Rev. Lett. 101, 203203 (2008)], but for which the measured cross sections could not be reproduced by theoretical calculations [Pavlovic et al., J. Phys. Chem. A 113, 14670 (2009)]. For the OH-He system, our experiments validate the inelastic cross sections determined from rigorous quantum calculations.

  17. Interacting He and Ar atoms: Revised theoretical interaction potential, dipole moment, and collision-induced absorption spectra

    SciTech Connect

    Meyer, Wilfried; Frommhold, Lothar

    2015-09-21

    Coupled cluster quantum chemical calculations of the potential energy surface and the induced dipole surface are reported for the He–Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range dipole coefficient D{sub 7} is obtained by perturbation methods. Collision-induced absorption spectra are computed quantum mechanically and compared with existing measurements.

  18. Interacting He and Ar atoms: Revised theoretical interaction potential, dipole moment, and collision-induced absorption spectra.

    PubMed

    Meyer, Wilfried; Frommhold, Lothar

    2015-09-21

    Coupled cluster quantum chemical calculations of the potential energy surface and the induced dipole surface are reported for the He-Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range dipole coefficient D7 is obtained by perturbation methods. Collision-induced absorption spectra are computed quantum mechanically and compared with existing measurements.

  19. Cross section database for carbon atoms and ions: Electron-impact ionization, excitation, and charge exchange in collisions with hydrogen atoms

    SciTech Connect

    Suno, Hiroya . E-mail: suno@jamstec.go.jp; Kato, Takako

    2006-07-15

    A database has been constructed consisting of the recommended cross sections for electron-impact excitation and ionization of carbon atoms and ions C, C{sup +}-C{sup 5+}, asl as for charge exchange processes between carbon ions C{sup +}-C{sup 6+} and hydrogen atoms. We have collected a large amount of theoretical and experimental cross section data from the literature, and have critically assessed their accuracy. The recommended cross sections, the best values for use, are expressed in the form of simple analytical functions. These are also presented in graphical form.

  20. The role of atomic and molecular physics for dissipative divertor operation in helium and deuterium plasmas

    NASA Astrophysics Data System (ADS)

    Canik, J. M.

    2016-10-01

    Recent experiments in DIII-D helium plasmas are examined to resolve the role of atomic and molecular physics in major discrepancies between experiment and modeling of dissipative divertor operation. Helium operation removes the complicated molecular processes of deuterium plasmas that are a prime candidate for the inability of standard fluid models (SOLPS, UEDGE) to reproduce dissipative divertor operation, primarily the consistent under-prediction of radiated power. With helium fueling, a high-recycling divertor was established with divertor densities increasing to ne,div >= 3 ×1020m-3 and temperatures decreasing to Te,div <= 2 eV as measured by divertor Thomson scattering (DTS). The electron pressure, pe , div decreased gradually with increasing density to less than 30% of the low density value. However, the ion flux to the divertor target did not decrease until the highest densities and lowest temperatures, Te,div <= 2 eV. In contrast, with deuterium operation, increasing density leads to a rapid transition from Te,div >= 10 eV to Te,div <= 3 eV, though both pe , div and ion flux do not decrease until Te,div <= 2 eV. These differences indicate an important role for molecular and atomic physics in the dynamics of divertor dissipation. Initial SOLPS modeling has reproduced ne and Te profiles at the midplane and divertor target, as well as the spatial structure of radiation patterns measured in moderate density helium plasmas. However, the modeled divertor radiation is less than measured, similar to deuterium simulations, suggesting processes more universal than species-specific atomic or molecular physics may be the source of radiation deficit. Detailed assessments of ne, Te profiles in the divertor volume, uniquely determined at DIII-D using DTS, are made along with analysis of measured and modeled line radiation to shed more light on these intriguing findings. Supported by the US DOE under DE-AC05-00OR22725.

  1. Ab Initio Study on Atomic Structures and Physical Properties of CdSe Quantum Nanodots

    DTIC Science & Technology

    2009-11-25

    CdSe quantum dots , with magic number (( CdSe )13, ( CdSe )19, ( CdSe )33 and ( CdSe )34 ). Effects of organic ligand binding on the stability of CdSe as well...calculations of optical absorption spectra for CdSe quantum dots , with magic number (( CdSe )13, ( CdSe )19, ( CdSe )33 and ( CdSe )34 ), have been calculated in...1 AOARD-08-4037 Title of Proposed Project: Ab initio study on atomic structures and physical

  2. Chapter Three - Atomic, Molecular, and Optical Physics in the Early Universe: From Recombination to Reionization

    NASA Astrophysics Data System (ADS)

    Glover, Simon C. O.; Chluba, Jens; Furlanetto, Steve R.; Pritchard, Jonathan R.; Savin, Daniel Wolf

    2014-08-01

    Our knowledge of the evolution of the early Universe hinges, in part, on our understanding of the underlying atomic, molecular, and optical (AMO) processes occurring during that epoch. Here we review the relevant AMO physics from when it first became important at a redshift of z ~ 6000, some 18,000 years after the Big Bang when electrons and ions began to recombine. The review continues through the formation of the first stars and galaxies and concludes after the radiation from these first objects has reionized the Universe at a z ~ 10, about a billion years after the Big Bang.

  3. Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

    PubMed Central

    Hayano, Ryugo S.

    2010-01-01

    Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants. PMID:20075605

  4. Application of the Finite Element Method in Atomic and Molecular Physics

    NASA Technical Reports Server (NTRS)

    Shertzer, Janine

    2007-01-01

    The finite element method (FEM) is a numerical algorithm for solving second order differential equations. It has been successfully used to solve many problems in atomic and molecular physics, including bound state and scattering calculations. To illustrate the diversity of the method, we present here details of two applications. First, we calculate the non-adiabatic dipole polarizability of Hi by directly solving the first and second order equations of perturbation theory with FEM. In the second application, we calculate the scattering amplitude for e-H scattering (without partial wave analysis) by reducing the Schrodinger equation to set of integro-differential equations, which are then solved with FEM.

  5. Nuclear-spin-independent short-range three-body physics in ultracold atoms.

    PubMed

    Gross, Noam; Shotan, Zav; Kokkelmans, Servaas; Khaykovich, Lev

    2010-09-03

    We investigate three-body recombination loss across a Feshbach resonance in a gas of ultracold 7Li atoms prepared in the absolute ground state and perform a comparison with previously reported results of a different nuclear-spin state [N. Gross, Phys. Rev. Lett. 103, 163202 (2009)]. We extend the previously reported universality in three-body recombination loss across a Feshbach resonance to the absolute ground state. We show that the positions and widths of recombination minima and Efimov resonances are identical for both states which indicates that the short-range physics is nuclear-spin independent.

  6. The Atomic Era: A new interdisciplinary course combining physics, the humanities and the social sciences

    NASA Astrophysics Data System (ADS)

    Carstens-Wickham, Belinda

    2001-05-01

    Southern Illinois University Edwardsville won funding from the federal interagency competition, Leadership Opportunity in Science and Humanities Education, which supported interdisciplinary courses combining the natural sciences and the humanities. The author analyses her experiences developing a very successful and popular interdisciplinary course, entitled The Atomic Era, which features a unique combination of physics, sociology and German studies taught jointly by a Physicist, a Sociologist and a Germanist. The objectives of the course, the laboratories and demonstrations, instructional goals, assignments, organization, testing, student and faculty assessment, expenses and the special challenges of coordinating three faculty members and a wide variety of topics and perspectives are addressed and analysed.

  7. ELASR - An electrostatic storage ring for atomic and molecular physics at KACST

    NASA Astrophysics Data System (ADS)

    El Ghazaly, Mohamed O. A.

    A new ELectrostAtic Storage Ring (ELASR) has been designed and built at the King Abdulaziz City for Science and Technology (KACST), in Riyadh, Saudi Arabia. It was developed to be the core of a new storage ring laboratory for atomic and molecular physics at KACST. ELASR follows the standard design of the pioneering storage ring ELISA and it thereby features a racetrack single-bend shaped ring. Complementary simulation code packages were used to work out the design under the requirements of the projected experiments. This paper reports a short description of the ELASR storage ring through an overview of its design and construction.

  8. Physics of our Days: Cooling and thermometry of atomic Fermi gases

    NASA Astrophysics Data System (ADS)

    Onofrio, R.

    2017-02-01

    We review the status of cooling techniques aimed at achieving the deepest quantum degeneracy for atomic Fermi gases. We first discuss some physics motivations, providing a quantitative assessment of the need for deep quantum degeneracy in relevant physics cases, such as the search for unconventional superfluid states. Attention is then focused on the most widespread technique to reach deep quantum degeneracy for Fermi systems, sympathetic cooling of Bose–Fermi mixtures, organizing the discussion according to the specific species involved. Various proposals to circumvent some of the limitations on achieving the deepest Fermi degeneracy, and their experimental realizations, are then reviewed. Finally, we discuss the extension of these techniques to optical lattices and the implementation of precision thermometry crucial to the understanding of the phase diagram of classical and quantum phase transitions in Fermi gases.

  9. Atomic layer deposition of metal oxide patterns on nonwoven fiber mats using localized physical compression.

    PubMed

    Sweet, William J; Oldham, Christopher J; Parsons, Gregory N

    2014-06-25

    Patterning is an essential part of many industrial processes from printing to semiconductor manufacturing. In this work, we demonstrate a new method to pattern and selectively coat nonwoven textiles by atomic layer deposition (ALD) using compressive mask patterning. A physical mask combined with mechanical compression allows lateral definition and fidelity of the ALD coating to be controlled. We produce features of several sizes on different nonwoven fiber materials and demonstrate the ability to limit diffusion effects to within <200 μm of the pattern edge. Lateral and vertical penetration of reactive growth species into nonwoven mats is investigated by plan-view and cross-sectional imaging. Vertical growth is also analyzed by imaging coating depth into fiber mat stacks. We develop a fully quantitative transport model that describes well the effect of fiber structure and mechanical compression on the extent of coating under the physical mask. This method could be implemented for high-volume patterning for applications including flexible electronics.

  10. A time-dependent wave packet approach to atom-diatom reactive collision probabilities - Theory and application to the H + H2(J = 0) system

    NASA Technical Reports Server (NTRS)

    Neuhauser, Daniel; Baer, Michael; Judson, Richard S.; Kouri, Donald J.

    1990-01-01

    This paper describes a new approach to the study of atom-diatom reactive collisions in three dimensions employing wave packets and the time-dependent Schroedinger equation. The method uses a projection operator approach to couple the inelastic and reactive portions of the total wave function and optical potentials to circumvent the necessity of using product arrangement coordinates. Reactive transition probabilities are calculated from the state resolved flux of the wave packet as it leaves the interaction region in the direction of the reactive arrangement channel. The present approach is used to obtain such vibrationally resolved probabilities for the three-dimensional H + H2 (J = 0) hydrogen exchange reaction, using a body-fixed system of coordinates.

  11. Independent-electron analysis of the x-ray spectra from single-electron capture in Ne10 + collisions with He, Ne, and Ar atoms

    NASA Astrophysics Data System (ADS)

    Leung, Anthony C. K.; Kirchner, Tom

    2015-09-01

    We present a theoretical study on the x-ray spectra from single-electron capture in 4.54 keV/amu Ne10 +-He, -Ne, and -Ar collisions. Single-particle capture probabilities were calculated using the two-center basis generator method within the independent electron model. In this framework we investigated the effects of a time-dependent screening potential that models target response on capture cross sections and x-ray spectra. Excellent agreement is shown with the previously measured relative cross sections and x-ray spectra and calculations based on the classical trajectory Monte Carlo method using the no-response single-particle electron capture probabilities in a multinomial single-electron capture analysis. Our results demonstrate the importance of using this consistent statistical analysis of single-electron capture within the independent electron model; a requirement that a previous calculation for the same collision problem using the two-center atomic-orbital close-coupling method may not have considered.

  12. Rapidity gaps and jets as a new-physics signature in very-high-energy hadron-hadron collisions

    NASA Astrophysics Data System (ADS)

    Bjorken, J. D.

    1993-01-01

    In hadron-hadron collisions, production of Higgs bosons and other color-singlet systems can occur via fusion of electroweak bosons, occasionally leaving a ``rapidity gap'' in the underlying-event structure. This observation, due to Dokshitzer, Khoze, and Troyan, is studied to see whether it serves as a signature for detection of the Higgs bosons, etc. We find it is a very strong signature at subprocess c.m. energies in excess of a few TeV. The most serious problem with this strategy is the estimation of the fraction of events containing the rapidity gap; most of the time the gap is filled by soft interactions of spectator degrees of freedom. We also study this question and estimate this ``survival probability of the rapidity gap'' to be of order 5%, with an uncertainty of a factor 3. Ways of testing this estimate and further discussion of the underlying hard-diffraction physics are presented.

  13. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

    SciTech Connect

    Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.

    1986-01-01

    Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the x-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the PHOton Beam Ion Source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. 26 refs., 4 figs., 1 tab.

  14. EDITORIAL: The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases

    NASA Astrophysics Data System (ADS)

    Petrović, Zoran Lj; Marić, Dragana; Malović, Gordana

    2011-03-01

    This special issue consists of papers that are associated with invited lectures, workshop papers and hot topic papers presented at the 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases (ESCAMPIG XX). This conference was organized in Novi Sad (Serbia) from 13 to 17 July 2010 by the Institute of Physics of the University of Belgrade. It is important to note that this is not a conference 'proceedings'. Following the initial selection process by the International Scientific Committee, all papers were submitted to the journal by the authors and have been fully peer reviewed to the standard required for publication in Plasma Sources Science and Technology (PSST). The papers are based on presentations given at the conference but are intended to be specialized technical papers covering all or part of the topic presented by the author during the meeting. The ESCAMPIG conference is a regular biennial Europhysics Conference of the European Physical Society focusing on collisional and radiative aspects of atomic and molecular physics in partially ionized gases as well as on plasma-surface interaction. The conference focuses on low-temperature plasma sciences in general and includes the following topics: Atomic and molecular processes in plasmas Transport phenomena, particle velocity distribution function Physical basis of plasma chemistry Plasma surface interaction (boundary layers, sheath, surface processes) Plasma diagnostics Plasma and discharges theory and simulation Self-organization in plasmas, dusty plasmas Upper atmospheric plasmas and space plasmas Low-pressure plasma sources High-pressure plasma sources Plasmas and gas flows Laser-produced plasmas During ESCAMPIG XX special sessions were dedicated to workshops on: Atomic and molecular collision data for plasma modeling, organized by Professors Z Lj Petrovic and N Mason Plasmas in medicine, organized by Dr N Puac and Professor G Fridman. The conference topics were represented in the

  15. Spectral anomalies of the light-induced drift of rubidium atoms caused by the velocity dependence of transport collision frequencies

    NASA Astrophysics Data System (ADS)

    Parkhomenko, A. I.; Shalagin, A. M.

    2014-02-01

    The spectral features of the light-induced drift (LID) velocity for rubidium atoms (85Rb and 87Rb) in an argon buffer medium and in binary buffer mixtures of noble gases (Ne + Ar, Ne + Kr, Ne + Xe, He + Ar, He + Kr, and He + Xe) have been investigated theoretically. A strong temperature dependence of the spectral shape of the LID signal for Rb atoms in an Ar atmosphere is predicted in the temperature range 450 K < T < 800 K. It is shown that the anomalous LID of Rb atoms in binary buffer mixtures of noble gases can be observed at almost any temperature (including the room one) depending on the fractions of neon or helium in these mixtures. The results obtained enable a highly accurate testing of the interatomic interaction potentials used to calculate the drift velocity for anomalous LID in LID experiments.

  16. Angular dependence of Doppler profiles of atomic emission produced in electron-molecule collisions: Estimation of anisotropy parameters

    NASA Astrophysics Data System (ADS)

    Nakashima, Keiji; Ogawa, Teiichiro

    1985-11-01

    The angular dependence of Doppler profiles of atomic fluorescence produced in electron impact dissociation of molecules was simulated in consideration of the effect of the anisotropy of dissociation and the ``polarization'' in magnetic sublevel. The asymmetry parameter b and the polarization of the electric vector of emission Jp are key parameters of Doppler profiles for the excited atom of known translational energy distribution. The difference of two Doppler profiles taken at 90° and 45°, which is denoted as angular difference Doppler profile, is shown to be useful to estimate these two key parameters.

  17. PREFACE: Hot Quarks 2014: Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions

    NASA Astrophysics Data System (ADS)

    2015-05-01

    The 6th edition of the Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions (Hot Quarks 2014) was held in Las Negras, Spain from 21-28 September 2014. Following the traditions of the conference, this meeting gathered more than 70 participants in the first years of their scientific careers. The present issue contains the proceedings of this workshop. As in the past, the Hot Quarks workshop offered a unique atmosphere for a lively discussion and interpretation of the current measurements from high energy nuclear collisions. Recent results and upgrades at CERN's Large Hadron Collider (LHC) and Brookhaven's Relativistic Heavy Ion Collider (RHIC) were presented. Recent theoretical developments were also extensively discussed as well as the perspectives for future facilities such as the Facility for Antiproton and Ion Research (FAIR) at Darmstadt and the Electron-Ion Collider at Brookhaven. The conference's goal to provide a platform for young researchers to learn and foster their interactions was successfully met. We wish to thank the sponsors of the Hot Quarks 2014 Conference, who supported the authors of this volume: Brookhaven National Laboratory (USA), CPAN (Spain), Czech Science Foundation (GACR) under grant 13-20841S (Czech Republic), European Laboratory for Particle Physics CERN (Switzerland), European Research Council under grant 259612 (EU), ExtreMe Matter Institute EMMI (Germany), Helmholtz Association and GSI under grant VH-NG-822, Helmholtz International Center for FAIR (Germany), National Science Foundation under grant No.1359622 (USA), Nuclear Physics Institute ASCR (Czech Republic), Patronato de la Alhambra y Generalife (Spain) and the Universidad de Granada (Spain). Javier López Albacete, Universidad de Granada (Spain) Jana Bielcikova, Nuclear Physics Inst. and Academy of Sciences (Czech Republic) Rainer J. Fries, Texas A&M University (USA) Raphaël Granier de Cassagnac, CNRS-IN2P3 and École polytechnique (France

  18. SU-E-T-64: CG-Based Radiation Therapy Simulator with Physical Modeling for Avoidance of Collisions Between Gantry and Couch Or Patient

    SciTech Connect

    Yamanouchi, M; Arimura, H; Yuda, I

    2014-06-01

    Purpose: It is time-consuming and might cause re-planning to check couch-gantry and patient-gantry collisions on a radiotherapy machine when using couch rotations for non-coplanar beam angles. The aim of this study was to develop a computer-graphics (CG)-based radiation therapy simulator with physical modeling for avoidance of collisions between gantry and couch or patient on a radiotherapy machine. Methods: The radiation therapy simulator was three-dimensionally constructed including a radiotherapy machine (Clinac iX, Varian Medical Systems), couch, and radiation treatment room according to their designs by using a physical-modeling-based computer graphics software (Blender, free and open-source). Each patient was modeled by applying a surface rendering technique to their planning computed tomography (CT) images acquired from 16-slice CT scanner (BrightSpeed, GE Healthcare). Immobilization devices for patients were scanned by the CT equipment, and were rendered as the patient planning CT images. The errors in the collision angle of the gantry with the couch or patient between gold standards and the estimated values were obtained by fixing the gantry angle for the evaluation of the proposed simulator. Results: The average error of estimated collision angles to the couch head side was -8.5% for gantry angles of 60 to 135 degree, and -5.5% for gantry angles of 225 to 300 degree. Moreover, the average error of estimated collision angles to the couch foot side was -1.1% for gantry angles of 60 to 135 degree, and 1.4% for gantry angles of 225 to 300 degree. Conclusion: The CG-based radiation therapy simulator could make it possible to estimate the collision angle between gantry and couch or patient on the radiotherapy machine without verifying the collision angles in the radiation treatment room.

  19. Evaluation of interatomic potentials for noble gas atoms from rainbow scattering under axial channeling at Ag(1 1 1) surface by computer simulations based on binary collision approximation

    NASA Astrophysics Data System (ADS)

    Takeuchi, Wataru

    2016-01-01

    The rainbow angles corresponding to pronounced peaks in the angular distributions of scattered projectiles with small angle, attributed to rainbow scattering (RS), under axial surface channeling conditions are strongly dependent on the interatomic potentials between projectiles and target atoms. The dependence of rainbow angles on normal energy of projectile energy to the target surface that has been experimentally obtained by Schüller and Winter (SW) (2007) for RS of He, Ne and Ar atoms from a Ag(1 1 1) surface with projectile energies of 3-60 keV was evaluated by the three-dimensional computer simulations using the ACOCT code based on the binary collision approximation with interatomic pair potentials. Consequently, the ACOCT results employing the Moliere pair potential with screening length correction close to adjustable one of O'Connor and Biersack (OB) formula are almost in agreement with the experimental ones, being self-consistent with the SW's ones analyzed by computer simulations of classical trajectory calculations as RS from corrugated equipotential planes based on continuum potentials including the Moliere pair potential with screening length correction of the OB formula.

  20. Relativistic Momentum-Space Equations with Applications to Atomic and Elementary Particle Physics

    NASA Astrophysics Data System (ADS)

    Hardekopf, Eugene Edward

    Relativistic equal-time wave equations obtained from field theory which describe bound states of N Dirac particles inevitably involve free or external-field positive -energy projection operators (LAMDA)(,+)(i). For N > 2 these operators are vital if the equations are to admit normaliz- able solutions. Such equations have been used in the past to obtain relativistic corrections to simple atomic systems, and to provide a theoretical basis for the Dirac-Hartree-Fock type of equations for many-electron atoms. These equations also find applications in ele- mentary particle physics in describing bound states of quarks. Here we initiate a numerical study of such equations, avoiding an expan- sion in powers of v/c. We work in momentum space, where the free projection operators are simple functions of (')p. We describe tech- niques for finding the eigenvalues and eigenfunctions of H(,+)(1,2) = h(,D)(1) + h(,D)(2) + (LAMDA)(,++)V(LAMDA)(,++) where h(,D)(i) is the free Dirac Hamiltonian and V is a local potential with either a (VBAR)(')r(,1)-(')r(,2)(VBAR)('-1) singularity in the case of atomic systems, or a (VBAR)(')r(,1)-(')r(,2)(VBAR) behavior plus a Coulomb-like singular- ity in the case of bound quarks. Results are presented for both pure Coulomb and a Coulomb plus Breit potential for the atomic case, and for a pure Lorentz scalar in the linear potential case. In the atomic case a wide range of m(,1)/m(,2) and coupling strength (gamma) is studied and the m(,2) = (INFIN) limit is compared with the Dirac equation. The magni- tude of level shifts associated with virtual pair production in such two-body systems is discussed. For intermediate values of (gamma) a com- parison is made between the numerical results and those of pertur- bation theory. We find that there can often be large corrections to perturbative results even for not terribly large values of v/c. We also study the strong coupling limit and find the value (gamma)(,max) for which the lowest-lying bound state

  1. Atomic physics and quantum optics using superconducting circuits: from the Dynamical Casimir effect to Majorana fermions

    NASA Astrophysics Data System (ADS)

    Nori, Franco

    2012-02-01

    This talk will present an overview of some of our recent results on atomic physics and quantum optics using superconducting circuits. Particular emphasis will be given to photons interacting with qubits, interferometry, the Dynamical Casimir effect, and also studying Majorana fermions using superconducting circuits.[4pt] References available online at our web site:[0pt] J.Q. You, Z.D. Wang, W. Zhang, F. Nori, Manipulating and probing Majorana fermions using superconducting circuits, (2011). Arxiv. J.R. Johansson, G. Johansson, C.M. Wilson, F. Nori, Dynamical Casimir effect in a superconducting coplanar waveguide, Phys. Rev. Lett. 103, 147003 (2009). [0pt] J.R. Johansson, G. Johansson, C.M. Wilson, F. Nori, Dynamical Casimir effect in superconducting microwave circuits, Phys. Rev. A 82, 052509 (2010). [0pt] C.M. Wilson, G. Johansson, A. Pourkabirian, J.R. Johansson, T. Duty, F. Nori, P. Delsing, Observation of the Dynamical Casimir Effect in a superconducting circuit. Nature, in press (Nov. 2011). P.D. Nation, J.R. Johansson, M.P. Blencowe, F. Nori, Stimulating uncertainty: Amplifying the quantum vacuum with superconducting circuits, Rev. Mod. Phys., in press (2011). [0pt] J.Q. You, F. Nori, Atomic physics and quantum optics using superconducting circuits, Nature 474, 589 (2011). [0pt] S.N. Shevchenko, S. Ashhab, F. Nori, Landau-Zener-Stuckelberg interferometry, Phys. Reports 492, 1 (2010). [0pt] I. Buluta, S. Ashhab, F. Nori. Natural and artificial atoms for quantum computation, Reports on Progress in Physics 74, 104401 (2011). [0pt] I.Buluta, F. Nori, Quantum Simulators, Science 326, 108 (2009). [0pt] L.F. Wei, K. Maruyama, X.B. Wang, J.Q. You, F. Nori, Testing quantum contextuality with macroscopic superconducting circuits, Phys. Rev. B 81, 174513 (2010). [0pt] J.Q. You, X.-F. Shi, X. Hu, F. Nori, Quantum emulation of a spin system with topologically protected ground states using superconducting quantum circuit, Phys. Rev. A 81, 063823 (2010).

  2. Influence of Halide Solutions on Collagen Networks: Measurements of Physical Properties by Atomic Force Microscopy

    PubMed Central

    Kempe, André; Lackner, Maximilian

    2016-01-01

    The influence of aqueous halide solutions on collagen coatings was tested. The effects on resistance against indentation/penetration on adhesion forces were measured by atomic force microscopy (AFM) and the change of Young's modulus of the coating was derived. Comparative measurements over time were conducted with halide solutions of various concentrations. Physical properties of the mesh-like coating generally showed large variability. Starting with a compact set of physical properties, data disperse after minutes. A trend of increase in elasticity and permeability was found for all halide solutions. These changes were largest in NaI, displaying a logical trend with ion size. However a correlation with concentration was not measured. Adhesion properties were found to be independent of mechanical properties. The paper also presents practical experience for AFM measurements of soft tissue under liquids, particularly related to data evaluation. The weakening in physical strength found after exposure to halide solutions may be interpreted as widening of the network structure or change in the chemical properties in part of the collagen fibres (swelling). In order to design customized surface coatings at optimized conditions also for medical applications, halide solutions might be used as agents with little impact on the safety of patients. PMID:27721994

  3. Studying collisions in the general physics laboratory with quadrature light emitting diode sensors

    NASA Astrophysics Data System (ADS)

    DeYoung, P. A.; Mulder, B.

    2002-12-01

    We have developed the means to measure position rapidly and precisely as a function of time in the general physics laboratory. These measurements are of sufficient quality that velocities and accelerations can be calculated from the position data using numerical derivatives. The precision of the measurements is such that any disagreement between theoretical expectations and experimental measurements is less than a few percent. Measurements of the system under study can be made as rapidly as every 200 μs, which is faster than the typical time scales over which the system changes. Measuring rapidly also allows one to investigate additional phenomena not previously accessible and to see features of the physics previously unobserved. The measurement system is based on commercially available sensors, computer hardware, and computer software (LABVIEW™). Many general physics laboratories based on this system have been developed but only an investigation of Newton's second law will be described here.

  4. STAR physics program and technical challenges with the RHIC energy scan with Au + Au collisions

    NASA Astrophysics Data System (ADS)

    Odyniec, G.; STAR Collaboration

    2008-10-01

    The future STAR physics program includes an Au + Au energy scan extending to low \\sqrt{s_{NN}} . Among other things, this energy scan will provide a unique opportunity to search for the phase boundary between quark-gluon plasma (QGP) and hadronic gas (HG), and a key landmark, a possible critical point, in the QCD phase diagram. Due to its large uniform acceptance and (with the addition of the time-of-flight detector) excellent particle identification capabilities, by the time of Run 10 (in 2010) STAR will be uniquely positioned to cover this physics in unprecedented depth and detail, as well as other novel physics possibilities. Running at very low energies poses major new challenges for accelerator experts at RHIC and for physicists preparing for data taking. We report on the status of STAR preparation for Run 10.

  5. Search for New Physics in Dielectron Events in 1.96-TeV Proton - Anti-proton Collisions

    SciTech Connect

    Ikado, Koji

    2004-03-01

    The authors have searched for new physics beyond the Standard Model of elementary particle physics in dielectron decay mode at the CDF (Collider Detector at Fermilab) experiment in {bar p}p collisions at √s = 1.96 TeV. The data were collected during the 2002-2003 runs corresponding to an integrated luminosity of 200 pb-1. Many extensions of the Standard Model have been proposed. Grand Unified Theories (GUT) assumes a larger gauge symmetry group and predict new gauge bosons. GUT has hierarchy problem in it and there have been many attempts to solve the hierarchy problem. Solutions for the hierarchy problem are supersymmetry, technicolor, large extra dimensions, warped extra dimensions and little Higgs models. The authors analyze the differential distribution of dielectron events in terms of their invariant mass and no significant excess is found in very high mass region. They present a 95% confidence level limit on the production cross section times branching ratio for new resonant particles decaying into an electron pair as a function of invariant mass. New resonant particles include new neutral gauge boson Z', Randall-Sundrum graviton, R-parity violating sneutrino, and technicolor particles. They also present limits on the effective Planck scale of large extra dimensions.

  6. Free-free absorption of infrared radiation in collisions of electrons with neutral rare-gas atoms

    NASA Technical Reports Server (NTRS)

    Stallcop, J. R.

    1974-01-01

    A relationship between the inverse bremsstrahlung absorption cross section and the electron neutral momentum transfer cross section has been utilized to determine the infrared free-free continuum absorption coefficient for the negative ions of helium, neon, argon, krypton, and xenon. The values of the momentum transfer cross section for this calculation have been obtained from experimental measurements. Analytical expressions for the absorption coefficient have also been developed. From the results of this calculation, it is possible to determine the absorption coefficient per unit electron density per neutral atom for temperatures in the range from 2500 to 25,000 K. The results are compared with those from tabulations of previous calculations and those computed from theoretical values of the phase shifts for the elastic scattering of electrons by neutral atoms.

  7. The branching ratio between reaction and relaxation in the removal of H2O from its |04>- vibrational state in collisions with H atoms

    NASA Astrophysics Data System (ADS)

    Barnes, Peter W.; Sims, Ian R.; Smith, Ian W. M.; Lendvay, György; Schatz, George C.

    2001-09-01

    The removal of H2O molecules from their |04>- vibrational state in collisions with H atoms can occur both by reaction, producing OH(v=0)+H2, and by nonreactive relaxation. We report an experimental measurement of the fraction (freac) that occurs by reaction. The value of freac is determined by comparing the yields of OH from three experiments in which the same concentration of H2O(|04>-) is prepared by overtone absorption of pulsed laser radiation and OH(v=0) is produced: (i) solely by the H+H2O(|04>-) reaction; (ii) solely by the photodissociation of H2O(|04>-) at 266 nm; and (iii) both by the photodissociation of H2O(|04>-) and by the subsequent reaction of a fraction of the remaining H2O(|04>-) with H atoms. Analysis of these experiments shows that freac=(0.34±0.11). The experimental results are compared with the results of two kinds of scattering calculations performed on a potential energy surface developed recently, specifically with this problem in mind. Using the vibrational coupled-channel infinite-order-sudden (VCC-IOS) method, rate coefficients have been calculated for individual vibrationally inelastic processes and then summed to find the rate coefficient (krelaxH) for total nonreactive relaxation from the |04>- state. The quasiclassical trajectory (QCT) method has been used to calculate the rate coefficient (kreac) for reaction between H atoms and H2O(|04>-). Both the calculated rate coefficient (i.e., krelaxH+kreac) for total loss from H2O(|04>-) and the calculated branching ratio, freac=kreac/(krelaxH+kreac)=0.38, are in quite good agreement with the experimental values.

  8. Observation of atomic-size Fraunhofer-type diffraction for single electron capture in He2++He collision

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Ma, X.; Zhu, X. L.; Zhang, S. F.

    2012-11-01

    Using COLTRIMS, we observed atomic-size Fraunhofer-type diffraction in reaction He2++He (1s2)→He+ (1s) + He+ (1s) at 40 keV. By comparing the angular spacing and fringes' position of differential cross sections with the calculated results of the Molecular Columbic over barrier Model and Two State Model, the latter model gives good agreement with the experiment.

  9. Satellite Collision Modeling with Physics-Based Hydrocodes: Debris Generation Predictions of the Iridium-Cosmos Collision Event and Other Impact Events

    SciTech Connect

    Springer, H K; Miller, W O; Levatin, J L; Pertica, A J; Olivier, S S

    2010-09-06

    Satellite collision debris poses risks to existing space assets and future space missions. Predictive models of debris generated from these hypervelocity collisions are critical for developing accurate space situational awareness tools and effective mitigation strategies. Hypervelocity collisions involve complex phenomenon that spans several time- and length-scales. We have developed a satellite collision debris modeling approach consisting of a Lagrangian hydrocode enriched with smooth particle hydrodynamics (SPH), advanced material failure models, detailed satellite mesh models, and massively parallel computers. These computational studies enable us to investigate the influence of satellite center-of-mass (CM) overlap and orientation, relative velocity, and material composition on the size, velocity, and material type distributions of collision debris. We have applied our debris modeling capability to the recent Iridium 33-Cosmos 2251 collision event. While the relative velocity was well understood in this event, the degree of satellite CM overlap and orientation was ill-defined. In our simulations, we varied the collision CM overlap and orientation of the satellites from nearly maximum overlap to partial overlap on the outermost extents of the satellites (i.e, solar panels and gravity boom). As expected, we found that with increased satellite overlap, the overall debris cloud mass and momentum (transfer) increases, the average debris size decreases, and the debris velocity increases. The largest predicted debris can also provide insight into which satellite components were further removed from the impact location. A significant fraction of the momentum transfer is imparted to the smallest debris (< 1-5mm, dependent on mesh resolution), especially in large CM overlap simulations. While the inclusion of the smallest debris is critical to enforcing mass and momentum conservation in hydrocode simulations, there seems to be relatively little interest in their

  10. Spin Changing Collisions of Hydrogen

    NASA Technical Reports Server (NTRS)

    Zygelman, Bernard

    2006-01-01

    We discuss spin changing collisions of hydrogen atoms. Employing a fully quantal theory we calculate and present new collision data. We discuss the respective roles of spin exchange and long range magnetic interactions in collisonal redistribution of sub-level populations. The calculated atomic data is needed for accurate modeling of 21 cm line emission/absorption by primordial hydrogen in the early universe.

  11. Making custom fiber lasers for use in an atomic physics experiment

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Cameron, Garnet; Nault, Kyla; Shiner, David

    2016-05-01

    Fiber lasers can be a reasonable choice for a laser source in atomic physics. Our particular applications involve the optical pumping and in some applications cooling of various transitions in atomic helium. Doped fiber with emission at the required wavelengths is necessary. Readily available fiber and approximate wavelength emission ranges include Yb (990 - 1150 nm), Er/Yb (1530 - 1625 nm) and Th (1900 -2100 nm). High efficiency conversion of pump photons into stable single frequency laser emission at the required wavelength is the function of the fiber laser. A simple fiber laser cavity uses a short (~ few mm) fiber grating high reflector mirror, a doped fiber section for the laser cavity, and a long (~ few cm) fiber grating output coupler. To ensure reliable single frequency operation, the laser cavity length should be within 2-3 times the output grating length. However the cavity length must be long enough for round trip gains to compensate for the output mirror transmission loss. Efficiency can be maximized by avoiding fiber splices in the fiber laser cavity. This requires that the gratings be written into the doped fiber directly. In our previous designs, back coupling of the fiber laser into the pump laser contributes to instability and sometimes caused catastrophic pump failure. Current designs use a fiber based wavelength splitter (WDM) to study and circumvent this problem. Data will be presented on the fiber lasers at 1083 nm. Work on a Thulium 2057 nm fiber laser will also be discussed. This work is supported by NSF Grant # 1404498.

  12. A distributed, graphical user interface based, computer control system for atomic physics experiments

    NASA Astrophysics Data System (ADS)

    Keshet, Aviv; Ketterle, Wolfgang

    2013-01-01

    Atomic physics experiments often require a complex sequence of precisely timed computer controlled events. This paper describes a distributed graphical user interface-based control system designed with such experiments in mind, which makes use of off-the-shelf output hardware from National Instruments. The software makes use of a client-server separation between a user interface for sequence design and a set of output hardware servers. Output hardware servers are designed to use standard National Instruments output cards, but the client-server nature should allow this to be extended to other output hardware. Output sequences running on multiple servers and output cards can be synchronized using a shared clock. By using a field programmable gate array-generated variable frequency clock, redundant buffers can be dramatically shortened, and a time resolution of 100 ns achieved over effectively arbitrary sequence lengths.

  13. ATOMIC PHYSICS PROCESSES IMPORTANT TO THE UNDERSTANDING OF THE SCRAPE-OFF LAYER OF TOKAMAKS

    SciTech Connect

    WEST, W.P.; GOLDSMITH,; B. EVANS,T.E.; OLSON, R.J.

    2002-05-01

    The region between the well-confined plasma and the vessel walls of a magnetic confinement fusion research device, the scrape-off layer (SOL), is typically rich in atomic and molecular physics processes. The most advanced magnetic confinement device, the magnetically diverted tokamak, uses a magnetic separatrix to isolate the confinement zone (closed flux surfaces) from the edge plasma (open field lines). Over most of their length the open field lines run parallel to the separatrix, forming a thin magnetic barrier with the nearby vessel walls. In a poloidally-localized region, the open field lines are directed away from the separatrix and into the divertor, a region spatially separated from the separatrix where intense plasma wall interaction can occur relatively safely. Recent data from several tokamaks indicate that particle transport across the field lines of the SOL can be somewhat faster than previously thought. In these cases, the rate at which particles reach the vessel wall is comparable to the rate to the divertor from parallel transport. The SOL can be thin enough that the recycling neutrals and sputtered impurities from the wall may refuel or contaminate the confinement zone more efficiently than divertor plasma wall interaction. Just inside the SOL is a confinement barrier that produces a sharp pedestal in plasma density and temperature. Understanding neutral transport through the SOL and into the pedestal is key to understanding particle balance and particle and impurity exhaust. The SOL plasma is sufficiently hot and dense to excite and ionize neutrals. Ion and neutral temperatures are high enough that charge exchange between the neutrals and fuel and impurity ions is fast. Excitation of neutrals can be fast enough to lead to nonlinear behavior in charge exchange and ionization processes. In this paper the detailed atomic physics important to the understanding of the neutral transport through the SOL will be discussed.

  14. Quenching of krypton atoms in the metastable 5s ({sup 3}P{sub 2}) state in collisions with krypton and helium atoms

    SciTech Connect

    Zayarnyi, D A; L'dov, A Yu; Kholin, I V

    2013-08-31

    We have used the absorption probe method to study the processes of collisional quenching of the metastable 5s [3/2]{sup o}{sub 2}({sup 3}P{sub 2}) state of the krypton atom in electron-beam-excited high-pressure He – Kr mixtures with a low content of krypton. The rate constants of plasma-chemical reactions Kr* + Kr + He → Kr*{sub 2}+He [(2.88 ± 0.29) × 10{sup -33} cm{sup 6} s{sup -1}], Kr* + 2He → HeKr* + He [(4.6 ± 1.3) × 10{sup -36} cm{sup 6} s{sup -1}] and Kr* + He → products + He [(1.51 ± 0.15) × 10{sup -15} cm{sup 3} s{sup -1}] are measured for the first time. The rate constants of similar reactions in the Ar – Kr mixture are refined. (active media)

  15. PREFACE: Hot Quarks 2012: Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions

    NASA Astrophysics Data System (ADS)

    Bleicher, Markus; Caines, Helen; Calderón de la Barca Sanchez, Manuel; Fries, Rainer; Granier de Cassagnac, Raphaël; Hippolyte, Boris; Mischke, André; Mócsy, Ágnes; Petersen, Hannah; Ruan, Lijuan; Salgado, Carlos A.

    2013-09-01

    The 5th edition of the Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions (Hot Quarks 2012) was held in Copamarina, Puerto Rico from 14-20 October 2012. As in previous years, this meeting gathered more than 70 participants in the early years of their scientific careers. This issue contains the proceedings of the workshop. As in the past, the Hot Quarks workshop offered a unique atmosphere for a lively discussion and interpretation of the current measurements from high energy nuclear collisions. Recent results and upgrades at CERN's Large Hadron Collider (LHC) and Brookhaven's Relativistic Heavy Ion Collider (RHIC) were presented. Measurements from the proton-led run at the CERN-LHC were shown for the first time at this meeting. Recent theoretical developments were also extensively discussed, as well as the proposals for future facilities such as the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, the Electron-Ion Collider at Brookhaven, and the LHeC. The conference's goal to provide a platform for young researchers to learn and foster their interactions was successfully met. We wish to thank the sponsors of the Hot Quarks 2012 Conference, who supported the authors of this volume: Brookhaven National Laboratory (USA), European Laboratory for Particle Physics CERN (Switzerland), European Research Council (EU), ExtreMe Matter Institute EMMI (Germany), Helmholtz International Center for FAIR (Germany), IN2P3/CNRS (France) and the European Research Council via grant #259612, Lawrence Berkeley National Laboratory (USA), Lawrence Livermore National Laboratory (USA), Los Alamos National Laboratory (USA), National Science Foundation (USA), and Netherlands Organization for Scientific Research (Netherlands). Marcus BleicherAndré Mischke Goethe-University Frankfurt and HIC4FAIRUtrecht University and Nikhef Amsterdam GermanyThe Netherlands Helen CainesÁgnes Mócsy Yale UniversityPratt Institute and Brookhaven National

  16. Theoretical Studies Relating to the Interaction of Radiation with Matter: Atomic Collision Processes Occurring in the Presence of Radiation Fields.

    DTIC Science & Technology

    1980-10-01

    Zener problem (two-level atom subjected to a hyperbolic secant radiation pulse) has been extended to three level systems in which the field couples...well resemble true pulses. It also enables one to solve the two-level part of 2246 E J Robinson the problem analytically (Rosen and Zener 1932, Robiscoe...4Z(1 -Z)]N-2a 2(Z)12 dZ (8) with a 2 given in terms of the variable Z by (Robiscoe 1978, Rosen and Zener 1932) r(--c) 2F (c-a +1,c-b +1,2-c,Z) (9

  17. Atomic Number Dependence of Hadron Production at Large Transverse Momentum in 300 GeV Proton--Nucleus Collisions

    DOE R&D Accomplishments Database

    Cronin, J. W.; Frisch, H. J.; Shochet, M. J.; Boymond, J. P.; Mermod, R.; Piroue, P. A.; Sumner, R. L.

    1974-07-15

    In an experiment at the Fermi National Accelerator Laboratory we have compared the production of large transverse momentum hadrons from targets of W, Ti, and Be bombarded by 300 GeV protons. The hadron yields were measured at 90 degrees in the proton-nucleon c.m. system with a magnetic spectrometer equipped with 2 Cerenkov counters and a hadron calorimeter. The production cross-sections have a dependence on the atomic number A that grows with P{sub 1}, eventually leveling off proportional to A{sup 1.1}.

  18. Effects of Solution Physical Properties on Copper and Chromium Signals in Flame Atomic Absorption Spectrometry

    NASA Astrophysics Data System (ADS)

    Rocha, Fàbio R. P.; Nòbrega, Joaquim A.

    1996-10-01

    Instrumental techniques, such as flame atomic absorption spectrometry (FAAS), are frequently used in chemical analysis. Independently of the technique used, the chemical principles must be considered to assure that the analytical results are correct. In FAAS, the most critical step is the sample introduction, since solutions need to be converted in an aerosol (nebulization process) that should contain drops with suitable size to attain the flame. Solution physical properties, such as viscosity and surface tension, can severely affect the analytical signals. Solutions with high viscosity are less easily aspirated and the analyte mass that reach the flame is reduced. The surface tension of the solution affects the size of the drops generated by the nebulization process and can modify the quantity of analyte that attain the flame. This work describes an experiment that allow demonstrating the effects of viscosity and surface tension on analytical signals, using a set of copper solutions prepared in different concentrations of ethanol and chromium solutions prepared in surfactant (tetrapropylammonium bromide) medium. The experiment can be carried out in a 4 h laboratory class and is useful to demonstrate to undergraduate students the effects of samples physical properties on the analytical signals in FAAS.

  19. Collision-Induced Dissociation of Electrosprayed Protein Complexes: An All-Atom Molecular Dynamics Model with Mobile Protons.

    PubMed

    Popa, Vlad; Trecroce, Danielle A; McAllister, Robert G; Konermann, Lars

    2016-06-16

    Electrospray ionization mass spectrometry (ESI-MS) has become an indispensable technique for examining noncovalent protein complexes. Collision-induced dissociation (CID) of these multiply protonated gaseous ions usually culminates in ejection of a single subunit with a disproportionately large amount of charge. Experiments suggest that this process involves subunit unfolding prior to separation from the residual complex, as well as H(+) migration onto the unravelling chain. Molecular dynamics (MD) simulations are a promising avenue for gaining detailed insights into these CID events. Unfortunately, typical MD algorithms do not allow for mobile protons. Here we address this limitation by implementing a strategy that combines atomistic force fields (such as OPLS/AA and CHARMM36) with a proton hopping algorithm, focusing on the tetrameric complexes transthyretin and streptavidin. Protons are redistributed over all acidic and basic sites in 20 ps intervals, subject to an energy function that reflects electrostatic interactions and proton affinities. Our simulations predict that nativelike conformers at the onset of collisional heating contain multiple salt bridges. Collisional heating initially causes subtle structural changes that lead to a gradual decline of these zwitterionic patterns. Many of the MD runs show gradual unfolding of a single subunit in conjunction with H(+) migration, culminating in subunit separation from the complex. However, there are also instances where two or more chains start to unfold simultaneously, giving rise to charge competition. The scission point where the "winning" subunit separates from the complex can be attained for different degrees of unfolding, giving rise to product ions in various charge states. The simulated product ion distributions are in close agreement with experimental CID data. Proton enrichment in the departing subunit is driven by charge-charge repulsion, but the combination of salt bridge depletion, charge migration

  20. Atomic Data for Fusion. Volume 5: Collisions of Carbon and Oxygen Ions with Electrons, H, H2 and He

    DTIC Science & Technology

    1987-02-01

    A. iller, Strahlenzentrum der Justus Liebig -Universitaet, Leihgesterner Weg 217, 6300 Giessen, West Germany 443. Dr. Y. Nakai, Dept. of Physics...Strahlenzentrum, Der Justus Liebig -Univ., Leihgesterner Weg 217, D-6300 Giessen, West Germany 465. Dr. A. Sanchez, Calle Angostura Quinta-Carmen, El

  1. Search for new physics in same-sign dilepton events in proton-proton collisions at [Formula: see text].

    PubMed

    Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Asilar, E; Bergauer, T; Brandstetter, J; Brondolin, E; Dragicevic, M; Erö, J; Flechl, M; Friedl, M; Frühwirth, R; Ghete, V M; Hartl, C; Hörmann, N; Hrubec, J; Jeitler, M; König, A; Krätschmer, I; Liko, D; Matsushita, T; Mikulec, I; Rabady, D; Rad, N; Rahbaran, B; Rohringer, H; Schieck, J; Strauss, J; Treberer-Treberspurg, W; Waltenberger, W; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Alderweireldt, S; De Wolf, E A; Janssen, X; Lauwers, J; Van De Klundert, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Abu Zeid, S; Blekman, F; D'Hondt, J; Daci, N; De Bruyn, I; Deroover, K; Heracleous, N; Lowette, S; Moortgat, S; Moreels, L; Olbrechts, A; Python, Q; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Parijs, I; Brun, H; Caillol, C; Clerbaux, B; De Lentdecker, G; Delannoy, H; Fasanella, G; Favart, L; Goldouzian, R; Grebenyuk, A; Karapostoli, G; Lenzi, T; Léonard, A; Luetic, J; Maerschalk, T; Marinov, A; Randle-Conde, A; Seva, T; Vander Velde, C; Vanlaer, P; Yonamine, R; Zenoni, F; Zhang, F; Cimmino, A; Cornelis, T; Dobur, D; Fagot, A; Garcia, G; Gul, M; Poyraz, D; Salva, S; Schöfbeck, R; Tytgat, M; Van Driessche, W; Yazgan, E; Zaganidis, N; Bakhshiansohi, H; Beluffi, C; Bondu, O; Brochet, S; Bruno, G; Caudron, A; Ceard, L; Visscher, S De; Delaere, C; Delcourt, M; Forthomme, L; Francois, B; Giammanco, A; Jafari, A; Jez, P; Komm, M; Lemaitre, V; Magitteri, A; Mertens, A; Musich, M; Nuttens, C; Piotrzkowski, K; Quertenmont, L; Selvaggi, M; Vidal Marono, M; Wertz, S; Beliy, N; Aldá Júnior, W L; Alves, F L; Alves, G A; Brito, L; Hensel, C; Moraes, A; Pol, M E; Rebello Teles, P; Belchior Batista Das Chagas, E; Carvalho, W; Chinellato, J; Custódio, A; Da Costa, E M; Da Silveira, G G; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Huertas Guativa, L M; Malbouisson, H; Matos Figueiredo, D; Mora Herrera, C; Mundim, L; Nogima, H; Prado Da Silva, W L; Santoro, A; Sznajder, A; Tonelli Manganote, E J; Vilela Pereira, A; Ahuja, S; Bernardes, C A; Dogra, S; Fernandez Perez Tomei, T R; Gregores, E M; Mercadante, P G; Moon, C S; Novaes, S F; Padula, Sandra S; Romero Abad, D; Ruiz Vargas, J C; Aleksandrov, A; Hadjiiska, R; Iaydjiev, P; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Glushkov, I; Litov, L; Pavlov, B; Petkov, P; Fang, W; Ahmad, M; Bian, J G; Chen, G M; Chen, H S; Chen, M; Chen, Y; Cheng, T; Jiang, C H; Leggat, D; Liu, Z; Romeo, F; Shaheen, S M; Spiezia, A; Tao, J; Wang, C; Wang, Z; Zhang, H; Zhao, J; Ban, Y; Li, Q; Liu, S; Mao, Y; Qian, S J; Wang, D; Xu, Z; Avila, C; Cabrera, A; Chaparro Sierra, L F; Florez, C; Gomez, J P; González Hernández, C F; Ruiz Alvarez, J D; Sanabria, J C; Godinovic, N; Lelas, D; Puljak, I; Ribeiro Cipriano, P M; Antunovic, Z; Kovac, M; Brigljevic, V; Ferencek, D; Kadija, K; Micanovic, S; Sudic, L; Attikis, A; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Finger, M; Finger, M; Carrera Jarrin, E; Elgammal, S; Mohamed, A; Mohammed, Y; Salama, E; Calpas, B; Kadastik, M; Murumaa, M; Perrini, L; Raidal, M; Tiko, A; Veelken, C; Eerola, P; Pekkanen, J; Voutilainen, M; Härkönen, J; Karimäki, V; Kinnunen, R; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Peltola, T; Tuominiemi, J; Tuovinen, E; Wendland, L; Talvitie, J; Tuuva, T; Besancon, M; Couderc, F; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Favaro, C; Ferri, F; Ganjour, S; Ghosh, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Kucher, I; Locci, E; Machet, M; Malcles, J; Rander, J; Rosowsky, A; Titov, M; Zghiche, A; Abdulsalam, A; Antropov, I; Baffioni, S; Beaudette, F; Busson, P; Cadamuro, L; Chapon, E; Charlot, C; Davignon, O; Granier de Cassagnac, R; Jo, M; Lisniak, S; Miné, P; Naranjo, I N; Nguyen, M; Ochando, C; Ortona, G; Paganini, P; Pigard, P; Regnard, S; Salerno, R; Sirois, Y; Strebler, T; Yilmaz, Y; Zabi, A; Agram, J-L; Andrea, J; Aubin, A; Bloch, D; Brom, J-M; Buttignol, M; Chabert, E C; Chanon, N; Collard, C; Conte, E; Coubez, X; Fontaine, J-C; Gelé, D; Goerlach, U; Le Bihan, A-C; Merlin, J A; Skovpen, K; Van Hove, P; Gadrat, S; Beauceron, S; Bernet, C; Boudoul, G; Bouvier, E; Carrillo Montoya, C A; Chierici, R; Contardo, D; Courbon, B; Depasse, P; El Mamouni, H; Fan, J; Fay, J; Gascon, S; Gouzevitch, M; Grenier, G; Ille, B; Lagarde, F; Laktineh, I B; Lethuillier, M; Mirabito, L; Pequegnot, A L; Perries, S; Popov, A; Sabes, D; Sordini, V; Vander Donckt, M; Verdier, P; Viret, S; Khvedelidze, A; Lomidze, D; Autermann, C; Beranek, S; Feld, L; Heister, A; Kiesel, M K; Klein, K; Lipinski, M; Ostapchuk, A; Preuten, M; Raupach, F; Schael, S; Schomakers, C; Schulte, J F; Schulz, J; Verlage, T; Weber, H; Zhukov, V; Brodski, M; Dietz-Laursonn, E; Duchardt, D; Endres, M; Erdmann, M; Erdweg, S; Esch, T; Fischer, R; Güth, A; Hebbeker, T; Heidemann, C; Hoepfner, K; Knutzen, S; Merschmeyer, M; Meyer, A; Millet, P; Mukherjee, S; Olschewski, M; Padeken, K; Papacz, P; Pook, T; Radziej, M; Reithler, H; Rieger, M; Scheuch, F; Sonnenschein, L; Teyssier, D; Thüer, S; Cherepanov, V; Erdogan, Y; Flügge, G; Haj Ahmad, W; Hoehle, F; Kargoll, B; Kress, T; Künsken, A; Lingemann, J; Nehrkorn, A; Nowack, A; Nugent, I M; Pistone, C; Pooth, O; Stahl, A; Aldaya Martin, M; Asawatangtrakuldee, C; Asin, I; Beernaert, K; Behnke, O; Behrens, U; Bin Anuar, A A; Borras, K; Campbell, A; Connor, P; Contreras-Campana, C; Costanza, F; Diez Pardos, C; Dolinska, G; Eckerlin, G; Eckstein, D; Gallo, E; Garay Garcia, J; Geiser, A; Gizhko, A; Grados Luyando, J M; Gunnellini, P; Harb, A; Hauk, J; Hempel, M; Jung, H; Kalogeropoulos, A; Karacheban, O; Kasemann, M; Keaveney, J; Kieseler, J; Kleinwort, C; Korol, I; Lange, W; Lelek, A; Leonard, J; Lipka, K; Lobanov, A; Lohmann, W; Mankel, R; Melzer-Pellmann, I-A; Meyer, A B; Mittag, G; Mnich, J; Mussgiller, A; Ntomari, E; Pitzl, D; Placakyte, R; Raspereza, A; Roland, B; Sahin, M Ö; Saxena, P; Schoerner-Sadenius, T; Seitz, C; Spannagel, S; Stefaniuk, N; Trippkewitz, K D; Van Onsem, G P; Walsh, R; Wissing, C; Blobel, V; Centis Vignali, M; Draeger, A R; Dreyer, T; Garutti, E; Goebel, K; Gonzalez, D; Haller, J; Hoffmann, M; Junkes, A; Klanner, R; Kogler, R; Kovalchuk, N; Lapsien, T; Lenz, T; Marchesini, I; Marconi, D; Meyer, M; Niedziela, M; Nowatschin, D; Ott, J; Pantaleo, F; Peiffer, T; Perieanu, A; Poehlsen, J; Sander, C; Scharf, C; Schleper, P; Schmidt, A; Schumann, S; Schwandt, J; Stadie, H; Steinbrück, G; Stober, F M; Stöver, M; Tholen, H; Troendle, D; Usai, E; Vanelderen, L; Vanhoefer, A; Vormwald, B; Barth, C; Baus, C; Berger, J; Butz, E; Chwalek, T; Colombo, F; De Boer, W; Dierlamm, A; Fink, S; Friese, R; Giffels, M; Gilbert, A; Haitz, D; Hartmann, F; Heindl, S M; Husemann, U; Katkov, I; Lobelle Pardo, P; Maier, B; Mildner, H; Mozer, M U; Müller, T; Müller, Th; Plagge, M; Quast, G; Rabbertz, K; Röcker, S; Roscher, F; Schröder, M; Sieber, G; Simonis, H J; Ulrich, R; Wagner-Kuhr, J; Wayand, S; Weber, M; Weiler, T; Williamson, S; Wöhrmann, C; Wolf, R; Anagnostou, G; Daskalakis, G; Geralis, T; Giakoumopoulou, V A; Kyriakis, A; Loukas, D; Topsis-Giotis, I; Agapitos, A; Kesisoglou, S; Panagiotou, A; Saoulidou, N; Tziaferi, E; Evangelou, I; Flouris, G; Foudas, C; Kokkas, P; Loukas, N; Manthos, N; Papadopoulos, I; Paradas, E; Filipovic, N; Bencze, G; Hajdu, C; Hidas, P; Horvath, D; Sikler, F; Veszpremi, V; Vesztergombi, G; Zsigmond, A J; Beni, N; Czellar, S; Karancsi, J; Makovec, A; Molnar, J; Szillasi, Z; Bartók, M; Raics, P; Trocsanyi, Z L; Ujvari, B; Bahinipati, S; Choudhury, S; Mal, P; Mandal, K; Nayak, A; Sahoo, D K; Sahoo, N; Swain, S K; Bansal, S; Beri, S B; Bhatnagar, V; Chawla, R; Bhawandeep, U; Kalsi, A K; Kaur, A; Kaur, M; Kumar, R; Mehta, A; Mittal, M; Singh, J B; Walia, G; Kumar, Ashok; Bhardwaj, A; Choudhary, B C; Garg, R B; Keshri, S; Kumar, A; Malhotra, S; Naimuddin, M; Nishu, N; Ranjan, K; Sharma, R; Sharma, V; Bhattacharya, R; Bhattacharya, S; Chatterjee, K; Dey, S; Dutt, S; Dutta, S; Ghosh, S; Majumdar, N; Modak, A; Mondal, K; Mukhopadhyay, S; Nandan, S; Purohit, A; Roy, A; Roy, D; Roy Chowdhury, S; Sarkar, S; Sharan, M; Thakur, S; Behera, P K; Chudasama, R; Dutta, D; Jha, V; Kumar, V; Mohanty, A K; Netrakanti, P K; Pant, L M; Shukla, P; Topkar, A; Bhowmik, S; Dewanjee, R K; Ganguly, S; Kumar, S; Maity, M; Parida, B; Sarkar, T; Aziz, T; Dugad, S; Kole, G; Mahakud, B; Mitra, S; Mohanty, G B; Sur, N; Sutar, B; Banerjee, S; Guchait, M; Jain, Sa; Majumder, G; Mazumdar, K; Wickramage, N; Chauhan, S; Dube, S; Kapoor, A; Kothekar, K; Rane, A; Sharma, S; Behnamian, H; Chenarani, S; Eskandari Tadavani, E; Etesami, S M; Fahim, A; Khakzad, M; Mohammadi Najafabadi, M; Naseri, M; Paktinat Mehdiabadi, S; Rezaei Hosseinabadi, F; Safarzadeh, B; Zeinali, M; Felcini, M; Grunewald, M; Abbrescia, M; Calabria, C; Caputo, C; Colaleo, A; Creanza, D; Cristella, L; De Filippis, N; De Palma, M; Fiore, L; Iaselli, G; Maggi, G; Maggi, M; Miniello, G; My, S; Nuzzo, S; Pompili, A; Pugliese, G; Radogna, R; Ranieri, A; Selvaggi, G; Silvestris, L; Venditti, R; Verwilligen, P; Abbiendi, G; Battilana, C; Bonacorsi, D; Braibant-Giacomelli, S; Brigliadori, L; Campanini, R; Capiluppi, P; Castro, A; Cavallo, F R; Chhibra, S S; Codispoti, G; Cuffiani, M; Dallavalle, G M; Fabbri, F; Fanfani, A; Fasanella, D; Giacomelli, P; Grandi, C; Guiducci, L; Marcellini, S; Masetti, G; Montanari, A; Navarria, F L; Perrotta, A; Rossi, A M; Rovelli, T; Siroli, G P; Tosi, N; Albergo, S; Chiorboli, M; Costa, S; Di Mattia, A; Giordano, F; Potenza, R; Tricomi, A; Tuve, C; Barbagli, G; Ciulli, V; Civinini, C; D'Alessandro, R; Focardi, E; Gori, V; Lenzi, P; Meschini, M; Paoletti, S; Sguazzoni, G; Viliani, L; Benussi, L; Bianco, S; Fabbri, F; Piccolo, D; Primavera, F; Calvelli, V; Ferro, F; Lo Vetere, M; Monge, M R; Robutti, E; Tosi, S; Brianza, L; Dinardo, M E; Fiorendi, S; Gennai, S; Ghezzi, A; Govoni, P; Malvezzi, S; Manzoni, R A; Marzocchi, B; Menasce, D; Moroni, L; Paganoni, M; Pedrini, D; Pigazzini, S; Ragazzi, S; Tabarelli de Fatis, T; Buontempo, S; Cavallo, N; De Nardo, G; Di Guida, S; Esposito, M; Fabozzi, F; Iorio, A O M; Lanza, G; Lista, L; Meola, S; Paolucci, P; Sciacca, C; Thyssen, F; Azzi, P; Bacchetta, N; Benato, L; Bisello, D; Boletti, A; Carlin, R; Carvalho Antunes De Oliveira, A; Checchia, P; Dall'Osso, M; De Castro Manzano, P; Dorigo, T; Dosselli, U; Gasparini, F; Gasparini, U; Gozzelino, A; Lacaprara, S; Margoni, M; Meneguzzo, A T; Pazzini, J; Pozzobon, N; Ronchese, P; Simonetto, F; Torassa, E; Zanetti, M; Zotto, P; Zucchetta, A; Zumerle, G; Braghieri, A; Magnani, A; Montagna, P; Ratti, S P; Re, V; Riccardi, C; Salvini, P; Vai, I; Vitulo, P; Alunni Solestizi, L; Bilei, G M; Ciangottini, D; Fanò, L; Lariccia, P; Leonardi, R; Mantovani, G; Menichelli, M; Saha, A; Santocchia, A; Androsov, K; Azzurri, P; Bagliesi, G; Bernardini, J; Boccali, T; Castaldi, R; Ciocci, M A; Dell'Orso, R; Donato, S; Fedi, G; Giassi, A; Grippo, M T; Ligabue, F; Lomtadze, T; Martini, L; Messineo, A; Palla, F; Rizzi, A; Savoy-Navarro, A; Spagnolo, P; Tenchini, R; Tonelli, G; Venturi, A; Verdini, P G; Barone, L; Cavallari, F; Cipriani, M; D'imperio, G; Del Re, D; Diemoz, M; Gelli, S; Jorda, C; Longo, E; Margaroli, F; Meridiani, P; Organtini, G; Paramatti, R; Preiato, F; Rahatlou, S; Rovelli, C; Santanastasio, F; Amapane, N; Arcidiacono, R; Argiro, S; Arneodo, M; Bartosik, N; Bellan, R; Biino, C; Cartiglia, N; Cenna, F; Costa, M; Covarelli, R; Degano, A; Demaria, N; Finco, L; Kiani, B; Mariotti, C; Maselli, S; Migliore, E; Monaco, V; Monteil, E; Obertino, M M; Pacher, L; Pastrone, N; Pelliccioni, M; Pinna Angioni, G L; Ravera, F; Romero, A; Ruspa, M; Sacchi, R; Shchelina, K; Sola, V; Solano, A; Staiano, A; Traczyk, P; Belforte, S; Casarsa, M; Cossutti, F; Della Ricca, G; La Licata, C; Schizzi, A; Zanetti, A; Kim, D H; Kim, G N; Kim, M S; Lee, S; Lee, S W; Oh, Y D; Sekmen, S; Son, D C; Yang, Y C; Lee, A; Brochero Cifuentes, J A; Kim, T J; Cho, S; Choi, S; Go, Y; Gyun, D; Ha, S; Hong, B; Jo, Y; Kim, Y; Lee, B; Lee, K; Lee, K S; Lee, S; Lim, J; Park, S K; Roh, Y; Almond, J; Kim, J; Oh, S B; Seo, S H; Yang, U K; Yoo, H D; Yu, G B; Choi, M; Kim, H; Kim, H; Kim, J H; Lee, J S H; Park, I C; Ryu, G; Ryu, M S; Choi, Y; Goh, J; Hwang, C; Lee, J; Yu, I; Dudenas, V; Juodagalvis, A; Vaitkus, J; Ahmed, I; Ibrahim, Z A; Komaragiri, J R; Md Ali, M A B; Mohamad Idris, F; Wan Abdullah, W A T; Yusli, M N; Zolkapli, Z; Castilla-Valdez, H; De La Cruz-Burelo, E; Heredia-De La Cruz, I; Hernandez-Almada, A; Lopez-Fernandez, R; Mejia Guisao, J; Sanchez-Hernandez, A; Carrillo Moreno, S; Oropeza Barrera, C; Vazquez Valencia, F; Carpinteyro, S; Pedraza, I; Salazar Ibarguen, H A; Uribe Estrada, C; Morelos Pineda, A; Krofcheck, D; Butler, P H; Ahmad, A; Ahmad, M; Hassan, Q; Hoorani, H R; Khan, W A; Shah, M A; Shoaib, M; Waqas, M; Bialkowska, H; Bluj, M; Boimska, B; Frueboes, T; Górski, M; Kazana, M; Nawrocki, K; Romanowska-Rybinska, K; Szleper, M; Zalewski, P; Bunkowski, K; Byszuk, A; Doroba, K; Kalinowski, A; Konecki, M; Krolikowski, J; Misiura, M; Olszewski, M; Walczak, M; Bargassa, P; Da Cruz E Silva, C Beirão; Di Francesco, A; Faccioli, P; Parracho, P G Ferreira; Gallinaro, M; Hollar, J; Leonardo, N; Lloret Iglesias, L; Nemallapudi, M V; Rodrigues Antunes, J; Seixas, J; Toldaiev, O; Vadruccio, D; Varela, J; Vischia, P; Afanasiev, S; Bunin, P; Gavrilenko, M; Golutvin, I; Gorbunov, I; Kamenev, A; Karjavin, V; Lanev, A; Malakhov, A; Matveev, V; Moisenz, P; Palichik, V; Perelygin, V; Shmatov, S; Shulha, S; Skatchkov, N; Smirnov, V; Voytishin, N; Zarubin, A; Chtchipounov, L; Golovtsov, V; Ivanov, Y; Kim, V; Kuznetsova, E; Murzin, V; Oreshkin, V; Sulimov, V; Vorobyev, A; Andreev, Yu; Dermenev, A; Gninenko, S; Golubev, N; Karneyeu, A; Kirsanov, M; Krasnikov, N; Pashenkov, A; Tlisov, D; Toropin, A; Epshteyn, V; Gavrilov, V; Lychkovskaya, N; Popov, V; Pozdnyakov, L; Safronov, G; Spiridonov, A; Toms, M; Vlasov, E; Zhokin, A; Chadeeva, M; Danilov, M; Markin, O; Andreev, V; Azarkin, M; Dremin, I; Kirakosyan, M; Leonidov, A; Rusakov, S V; Terkulov, A; Baskakov, A; Belyaev, A; Boos, E; Dubinin, M; Dudko, L; Ershov, A; Gribushin, A; Klyukhin, V; Kodolova, O; Lokhtin, I; Miagkov, I; Obraztsov, S; Petrushanko, S; Savrin, V; Snigirev, A; Azhgirey, I; Bayshev, I; Bitioukov, S; Elumakhov, D; Kachanov, V; Kalinin, A; Konstantinov, D; Krychkine, V; Petrov, V; Ryutin, R; Sobol, A; Troshin, S; Tyurin, N; Uzunian, A; Volkov, A; Adzic, P; Cirkovic, P; Devetak, D; Milosevic, J; Rekovic, V; Alcaraz Maestre, J; Calvo, E; Cerrada, M; Chamizo Llatas, M; Colino, N; De La Cruz, B; Delgado Peris, A; Escalante Del Valle, A; Fernandez Bedoya, C; Ramos, J P Fernández; Flix, J; Fouz, M C; Garcia-Abia, P; Gonzalez Lopez, O; Goy Lopez, S; Hernandez, J M; Josa, M I; Navarro De Martino, E; Yzquierdo, A Pérez-Calero; Puerta Pelayo, J; Quintario Olmeda, A; Redondo, I; Romero, L; Soares, M S; de Trocóniz, J F; Missiroli, M; Moran, D; Cuevas, J; Fernandez Menendez, J; Gonzalez Caballero, I; González Fernández, J R; Palencia Cortezon, E; Sanchez Cruz, S; Suárez Andrés, I; Vizan Garcia, J M; Cabrillo, I J; Calderon, A; Castiñeiras De Saa, J R; Curras, E; Fernandez, M; Garcia-Ferrero, J; Gomez, G; Lopez Virto, A; Marco, J; Martinez Rivero, C; Matorras, F; Piedra Gomez, J; Rodrigo, T; Ruiz-Jimeno, A; Scodellaro, L; Trevisani, N; Vila, I; Vilar Cortabitarte, R; Abbaneo, D; Auffray, E; Auzinger, G; Bachtis, M; Baillon, P; Ball, A H; Barney, D; Bloch, P; Bocci, A; Bonato, A; Botta, C; Camporesi, T; Castello, R; Cepeda, M; Cerminara, G; D'Alfonso, M; d'Enterria, D; Dabrowski, A; Daponte, V; David, A; De Gruttola, M; De Guio, F; De Roeck, A; Di Marco, E; Dobson, M; Dordevic, M; Dorney, B; du Pree, T; Duggan, D; Dünser, M; Dupont, N; Elliott-Peisert, A; Fartoukh, S; Franzoni, G; Fulcher, J; Funk, W; Gigi, D; Gill, K; Girone, M; Glege, F; Gulhan, D; Gundacker, S; Guthoff, M; Hammer, J; Harris, P; Hegeman, J; Innocente, V; Janot, P; Kirschenmann, H; Knünz, V; Kornmayer, A; Kortelainen, M J; Kousouris, K; Krammer, M; Lecoq, P; Lourenço, C; Lucchini, M T; Malgeri, L; Mannelli, M; Martelli, A; Meijers, F; Mersi, S; Meschi, E; Moortgat, F; Morovic, S; Mulders, M; Neugebauer, H; Orfanelli, S; Orsini, L; Pape, L; Perez, E; Peruzzi, M; Petrilli, A; Petrucciani, G; Pfeiffer, A; Pierini, M; Racz, A; Reis, T; Rolandi, G; Rovere, M; Ruan, M; Sakulin, H; Sauvan, J B; Schäfer, C; Schwick, C; Seidel, M; Sharma, A; Silva, P; Simon, M; Sphicas, P; Steggemann, J; Stoye, M; Takahashi, Y; Tosi, M; Treille, D; Triossi, A; Tsirou, A; Veckalns, V; Veres, G I; Wardle, N; Zagozdzinska, A; Zeuner, W D; Bertl, W; Deiters, K; Erdmann, W; Horisberger, R; Ingram, Q; Kaestli, H C; Kotlinski, D; Langenegger, U; Rohe, T; Bachmair, F; Bäni, L; Bianchini, L; Casal, B; Dissertori, G; Dittmar, M; Donegà, M; Eller, P; Grab, C; Heidegger, C; Hits, D; Hoss, J; Kasieczka, G; Lecomte, P; Lustermann, W; Mangano, B; Marionneau, M; Martinez Ruiz Del Arbol, P; Masciovecchio, M; Meinhard, M T; Meister, D; Micheli, F; Musella, P; Nessi-Tedaldi, F; Pandolfi, F; Pata, J; Pauss, F; Perrin, G; Perrozzi, L; Quittnat, M; Rossini, M; Schönenberger, M; Starodumov, A; Takahashi, M; Tavolaro, V R; Theofilatos, K; Wallny, R; Aarrestad, T K; Amsler, C; Caminada, L; Canelli, M F; Chiochia, V; De Cosa, A; Galloni, C; Hinzmann, A; Hreus, T; Kilminster, B; Lange, C; Ngadiuba, J; Pinna, D; Rauco, G; Robmann, P; Salerno, D; Yang, Y; Candelise, V; Doan, T H; Jain, Sh; Khurana, R; Konyushikhin, M; Kuo, C M; Lin, W; Lu, Y J; Pozdnyakov, A; Yu, S S; Kumar, Arun; Chang, P; Chang, Y H; Chang, Y W; Chao, Y; Chen, K F; Chen, P H; Dietz, C; Fiori, F; Hou, W-S; Hsiung, Y; Liu, Y F; Lu, R-S; Miñano Moya, M; Paganis, E; Psallidas, A; Tsai, J F; Tzeng, Y M; Asavapibhop, B; Singh, G; Srimanobhas, N; Suwonjandee, N; Adiguzel, A; Cerci, S; Damarseckin, S; Demiroglu, Z S; Dozen, C; Dumanoglu, I; Girgis, S; Gokbulut, G; Guler, Y; Gurpinar, E; Hos, I; Kangal, E E; Kara, O; Kayis Topaksu, A; Kiminsu, U; Oglakci, M; Onengut, G; Ozdemir, K; Sunar Cerci, D; Tali, B; Turkcapar, S; Zorbakir, I S; Zorbilmez, C; Bilin, B; Bilmis, S; Isildak, B; Karapinar, G; Yalvac, M; Zeyrek, M; Gülmez, E; Kaya, M; Kaya, O; Yetkin, E A; Yetkin, T; Cakir, A; Cankocak, K; Sen, S; Grynyov, B; Levchuk, L; Sorokin, P; Aggleton, R; Ball, F; Beck, L; Brooke, J J; Burns, D; Clement, E; Cussans, D; Flacher, H; Goldstein, J; Grimes, M; Heath, G P; Heath, H F; Jacob, J; Kreczko, L; Lucas, C; Newbold, D M; Paramesvaran, S; Poll, A; Sakuma, T; Seif El Nasr-Storey, S; Smith, D; Smith, V J; Bell, K W; Belyaev, A; Brew, C; Brown, R M; Calligaris, L; Cieri, D; Cockerill, D J A; Coughlan, J A; Harder, K; Harper, S; Olaiya, E; Petyt, D; Shepherd-Themistocleous, C H; Thea, A; Tomalin, I R; Williams, T; Baber, M; Bainbridge, R; Buchmuller, O; Bundock, A; Burton, D; Casasso, S; Citron, M; Colling, D; Corpe, L; Dauncey, P; Davies, G; De Wit, A; Della Negra, M; Dunne, P; Elwood, A; Futyan, D; Haddad, Y; Hall, G; Iles, G; Lane, R; Laner, C; Lucas, R; Lyons, L; Magnan, A-M; Malik, S; Mastrolorenzo, L; Nash, J; Nikitenko, A; Pela, J; Penning, B; Pesaresi, M; Raymond, D M; Richards, A; Rose, A; Seez, C; Tapper, A; Uchida, K; Vazquez Acosta, M; Virdee, T; Zenz, S C; Cole, J E; Hobson, P R; Khan, A; Kyberd, P; Leslie, D; Reid, I D; Symonds, P; Teodorescu, L; Turner, M; Borzou, A; Call, K; Dittmann, J; Hatakeyama, K; Liu, H; Pastika, N; Charaf, O; Cooper, S I; Henderson, C; Rumerio, P; Arcaro, D; Avetisyan, A; Bose, T; Gastler, D; Rankin, D; Richardson, C; Rohlf, J; Sulak, L; Zou, D; Benelli, G; Berry, E; Cutts, D; Garabedian, A; Hakala, J; Heintz, U; Hogan, J M; Jesus, O; Laird, E; Landsberg, G; Mao, Z; Narain, M; Piperov, S; Sagir, S; Spencer, E; Syarif, R; Breedon, R; Breto, G; Burns, D; De La Barca Sanchez, M Calderon; Chauhan, S; Chertok, M; Conway, J; Conway, R; Cox, P T; Erbacher, R; Flores, C; Funk, G; Gardner, M; Ko, W; Lander, R; Mclean, C; Mulhearn, M; Pellett, D; Pilot, J; Ricci-Tam, F; Shalhout, S; Smith, J; Squires, M; Stolp, D; Tripathi, M; Wilbur, S; Yohay, R; Cousins, R; Everaerts, P; Florent, A; Hauser, J; Ignatenko, M; Saltzberg, D; Takasugi, E; Valuev, V; Weber, M; Burt, K; Clare, R; Ellison, J; Gary, J W; Hanson, G; Heilman, J; Jandir, P; Kennedy, E; Lacroix, F; Long, O R; Malberti, M; Negrete, M Olmedo; Paneva, M I; Shrinivas, A; Wei, H; Wimpenny, S; Yates, B R; Branson, J G; Cerati, G B; Cittolin, S; Derdzinski, M; Gerosa, R; Holzner, A; Klein, D; Krutelyov, V; Letts, J; Macneill, I; Olivito, D; Padhi, S; Pieri, M; Sani, M; Sharma, V; Simon, S; Tadel, M; Vartak, A; Wasserbaech, S; Welke, C; Wood, J; Würthwein, F; Yagil, A; Zevi Della Porta, G; Amin, N; Bhandari, R; Bradmiller-Feld, J; Campagnari, C; Dishaw, A; Dutta, V; Flowers, K; Franco Sevilla, M; Geffert, P; George, C; Golf, F; Gouskos, L; Gran, J; Heller, R; Incandela, J; Mccoll, N; Mullin, S D; Ovcharova, A; Richman, J; Stuart, D; Suarez, I; West, C; Yoo, J; Anderson, D; Apresyan, A; Bendavid, J; Bornheim, A; Bunn, J; Chen, Y; Duarte, J; Mott, A; Newman, H B; Pena, C; Spiropulu, M; Vlimant, J R; Xie, S; Zhu, R Y; Andrews, M B; Azzolini, V; Carlson, B; Ferguson, T; Paulini, M; Russ, J; Sun, M; Vogel, H; Vorobiev, I; Cumalat, J P; Ford, W T; Jensen, F; Johnson, A; Krohn, M; Mulholland, T; Stenson, K; Wagner, S R; Alexander, J; Chaves, J; Chu, J; Dittmer, S; Mcdermott, K; Mirman, N; Nicolas Kaufman, G; Patterson, J R; Rinkevicius, A; Ryd, A; Skinnari, L; Soffi, L; Tan, S M; Tao, Z; Thom, J; Tucker, J; Wittich, P; Zientek, M; Winn, D; Abdullin, S; Albrow, M; Apollinari, G; Banerjee, S; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Bolla, G; Burkett, K; Butler, J N; Cheung, H W K; Chlebana, F; Cihangir, S; Cremonesi, M; Elvira, V D; Fisk, I; Freeman, J; Gottschalk, E; Gray, L; Green, D; Grünendahl, S; Gutsche, O; Hare, D; Harris, R M; Hasegawa, S; Hirschauer, J; Hu, Z; Jayatilaka, B; Jindariani, S; Johnson, M; Joshi, U; Klima, B; Kreis, B; Lammel, S; Linacre, J; Lincoln, D; Lipton, R; Liu, T; Lopes De Sá, R; Lykken, J; Maeshima, K; Magini, N; Marraffino, J M; Maruyama, S; Mason, D; McBride, P; Merkel, P; Mrenna, S; Nahn, S; Newman-Holmes, C; O'Dell, V; Pedro, K; Prokofyev, O; Rakness, G; Ristori, L; Sexton-Kennedy, E; Soha, A; Spalding, W J; Spiegel, L; Stoynev, S; Strobbe, N; Taylor, L; Tkaczyk, S; Tran, N V; Uplegger, L; Vaandering, E W; Vernieri, C; Verzocchi, M; Vidal, R; Wang, M; Weber, H A; Whitbeck, A; Acosta, D; Avery, P; Bortignon, P; Bourilkov, D; Brinkerhoff, A; Carnes, A; Carver, M; Curry, D; Das, S; Field, R D; Furic, I K; Konigsberg, J; Korytov, A; Ma, P; Matchev, K; Mei, H; Milenovic, P; Mitselmakher, G; Rank, D; Shchutska, L; Sperka, D; Thomas, L; Wang, J; Wang, S; Yelton, J; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Ackert, A; Adams, J R; Adams, T; Askew, A; Bein, S; Diamond, B; Hagopian, S; Hagopian, V; Johnson, K F; Khatiwada, A; Prosper, H; Santra, A; Weinberg, M; Baarmand, M M; Bhopatkar, V; Colafranceschi, S; Hohlmann, M; Noonan, D; Roy, T; Yumiceva, F; Adams, M R; Apanasevich, L; Berry, D; Betts, R R; Bucinskaite, I; Cavanaugh, R; Evdokimov, O; Gauthier, L; Gerber, C E; Hofman, D J; Kurt, P; O'Brien, C; Sandoval Gonzalez, L D; Turner, P; Varelas, N; Wang, H; Wu, Z; Zakaria, M; Zhang, J; Bilki, B; Clarida, W; Dilsiz, K; Durgut, S; Gandrajula, R P; Haytmyradov, M; Khristenko, V; Merlo, J-P; Mermerkaya, H; Mestvirishvili, A; Moeller, A; Nachtman, J; Ogul, H; Onel, Y; Ozok, F; Penzo, A; Snyder, C; Tiras, E; Wetzel, J; Yi, K; Anderson, I; Blumenfeld, B; Cocoros, A; Eminizer, N; Fehling, D; Feng, L; Gritsan, A V; Maksimovic, P; Osherson, M; Roskes, J; Sarica, U; Swartz, M; Xiao, M; Xin, Y; You, C; Al-Bataineh, A; Baringer, P; Bean, A; Bowen, J; Bruner, C; Castle, J; Kenny, R P; Kropivnitskaya, A; Majumder, D; Mcbrayer, W; Murray, M; Sanders, S; Stringer, R; Tapia Takaki, J D; Wang, Q; Ivanov, A; Kaadze, K; Khalil, S; Makouski, M; Maravin, Y; Mohammadi, A; Saini, L K; Skhirtladze, N; Toda, S; Lange, D; Rebassoo, F; Wright, D; Anelli, C; Baden, A; Baron, O; Belloni, A; Calvert, B; Eno, S C; Ferraioli, C; Gomez, J A; Hadley, N J; Jabeen, S; Kellogg, R G; Kolberg, T; Kunkle, J; Lu, Y; Mignerey, A C; Shin, Y H; Skuja, A; Tonjes, M B; Tonwar, S C; Abercrombie, D; Allen, B; Apyan, A; Barbieri, R; Baty, A; Bi, R; Bierwagen, K; Brandt, S; Busza, W; Cali, I A; Demiragli, Z; Di Matteo, L; Gomez Ceballos, G; Goncharov, M; Hsu, D; Iiyama, Y; Innocenti, G M; Klute, M; Kovalskyi, D; Krajczar, K; Lai, Y S; Lee, Y-J; Levin, A; Luckey, P D; Marini, A C; Mcginn, C; Mironov, C; Narayanan, S; Niu, X; Paus, C; Roland, C; Roland, G; Salfeld-Nebgen, J; Stephans, G S F; Sumorok, K; Tatar, K; Varma, M; Velicanu, D; Veverka, J; Wang, J; Wang, T W; Wyslouch, B; Yang, M; Zhukova, V; Benvenuti, A C; Chatterjee, R M; Evans, A; Finkel, A; Gude, A; Hansen, P; Kalafut, S; Kao, S C; Kubota, Y; Lesko, Z; Mans, J; Nourbakhsh, S; Ruckstuhl, N; Rusack, R; Tambe, N; Turkewitz, J; Acosta, J G; Oliveros, S; Avdeeva, E; Bartek, R; Bloom, K; Bose, S; Claes, D R; Dominguez, A; Fangmeier, C; Gonzalez Suarez, R; Kamalieddin, R; Knowlton, D; Kravchenko, I; Malta Rodrigues, A; Meier, F; Monroy, J; Siado, J E; Snow, G R; Stieger, B; Alyari, M; Dolen, J; George, J; Godshalk, A; Harrington, C; Iashvili, I; Kaisen, J; Kharchilava, A; Kumar, A; Parker, A; Rappoccio, S; Roozbahani, B; Alverson, G; Barberis, E; Baumgartel, D; Hortiangtham, A; Massironi, A; Morse, D M; Nash, D; Orimoto, T; Teixeira De Lima, R; Trocino, D; Wang, R-J; Wood, D; Bhattacharya, S; Hahn, K A; Kubik, A; Low, J F; Mucia, N; Odell, N; Pollack, B; Schmitt, M H; Sung, K; Trovato, M; Velasco, M; Dev, N; Hildreth, M; Hurtado Anampa, K; Jessop, C; Karmgard, D J; Kellams, N; Lannon, K; Marinelli, N; Meng, F; Mueller, C; Musienko, Y; Planer, M; Reinsvold, A; Ruchti, R; Smith, G; Taroni, S; Valls, N; Wayne, M; Wolf, M; Woodard, A; Alimena, J; Antonelli, L; Brinson, J; Bylsma, B; Durkin, L S; Flowers, S; Francis, B; Hart, A; Hill, C; Hughes, R; Ji, W; Liu, B; Luo, W; Puigh, D; Winer, B L; Wulsin, H W; Cooperstein, S; Driga, O; Elmer, P; Hardenbrook, J; Hebda, P; Luo, J; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Palmer, C; Piroué, P; Stickland, D; Tully, C; Zuranski, A; Malik, S; Barker, A; Barnes, V E; Benedetti, D; Folgueras, S; Gutay, L; Jha, M K; Jones, M; Jung, A W; Jung, K; Miller, D H; Neumeister, N; Radburn-Smith, B C; Shi, X; Sun, J; Svyatkovskiy, A; Wang, F; Xie, W; Xu, L; Parashar, N; Stupak, J; Adair, A; Akgun, B; Chen, Z; Ecklund, K M; Geurts, F J M; Guilbaud, M; Li, W; Michlin, B; Northup, M; Padley, B P; Redjimi, R; Roberts, J; Rorie, J; Tu, Z; Zabel, J; Betchart, B; Bodek, A; de Barbaro, P; Demina, R; Duh, T; Ferbel, Y T; Galanti, M; Garcia-Bellido, A; Han, J; Hindrichs, O; Khukhunaishvili, A; Lo, K H; Tan, P; Verzetti, M; Chou, J P; Contreras-Campana, E; Gershtein, Y; Gómez Espinosa, T A; Halkiadakis, E; Heindl, M; Hidas, D; Hughes, E; Kaplan, S; Kunnawalkam Elayavalli, R; Kyriacou, S; Lath, A; Nash, K; Saka, H; Salur, S; Schnetzer, S; Sheffield, D; Somalwar, S; Stone, R; Thomas, S; Thomassen, P; Walker, M; Foerster, M; Heideman, J; Riley, G; Rose, K; Spanier, S; Thapa, K; Bouhali, O; Celik, A; Dalchenko, M; De Mattia, M; Delgado, A; Dildick, S; Eusebi, R; Gilmore, J; Huang, T; Juska, E; Kamon, T; Mueller, R; Pakhotin, Y; Patel, R; Perloff, A; Perniè, L; Rathjens, D; Rose, A; Safonov, A; Tatarinov, A; Ulmer, K A; Akchurin, N; Cowden, C; Damgov, J; Dragoiu, C; Dudero, P R; Faulkner, J; Kunori, S; Lamichhane, K; Lee, S W; Libeiro, T; Undleeb, S; Volobouev, I; Wang, Z; Delannoy, A G; Greene, S; Gurrola, A; Janjam, R; Johns, W; Maguire, C; Melo, A; Ni, H; Sheldon, P; Tuo, S; Velkovska, J; Xu, Q; Arenton, M W; Barria, P; Cox, B; Goodell, J; Hirosky, R; Ledovskoy, A; Li, H; Neu, C; Sinthuprasith, T; Sun, X; Wang, Y; Wolfe, E; Xia, F; Clarke, C; Harr, R; Karchin, P E; Lamichhane, P; Sturdy, J; Belknap, D A; Dasu, S; Dodd, L; Duric, S; Gomber, B; Grothe, M; Herndon, M; Hervé, A; Klabbers, P; Lanaro, A; Levine, A; Long, K; Loveless, R; Ojalvo, I; Perry, T; Pierro, G A; Polese, G; Ruggles, T; Savin, A; Sharma, A; Smith, N; Smith, W H; Taylor, D; Woods, N; Collaboration, Authorinst The Cms

    2016-01-01

    A search for new physics is performed using events with two isolated same-sign leptons, two or more jets, and missing transverse momentum. The results are based on a sample of proton-proton collisions at a center-of-mass energy of 13[Formula: see text] recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 2.3 [Formula: see text]. Multiple search regions are defined by classifying events in terms of missing transverse momentum, the scalar sum of jet transverse momenta, the transverse mass associated with a [Formula: see text] boson candidate, the number of jets, the number of [Formula: see text] quark jets, and the transverse momenta of the leptons in the event. The analysis is sensitive to a wide variety of possible signals beyond the standard model. No excess above the standard model background expectation is observed. Constraints are set on various supersymmetric models, with gluinos and bottom squarks excluded for masses up to 1300 and 680[Formula: see text], respectively, at the 95 % confidence level. Upper limits on the cross sections for the production of two top quark-antiquark pairs (119[Formula: see text]) and two same-sign top quarks (1.7[Formula: see text]) are also obtained. Selection efficiencies and model independent limits are provided to allow further interpretations of the results.

  2. Calculations of H2O microwave line broadening in collisions with He atoms - Sensitivity to potential energy surfaces

    NASA Technical Reports Server (NTRS)

    Green, Sheldon; Defrees, D. J.; Mclean, A. D.

    1991-01-01

    Theoretical computations of broadening parameters are reported for three microwave lines of H2O in a bath of He atoms. The potential-energy surfaces employed are corrected for basis-set superposition error, and their reliability is checked by repeating the calculations with a different basis set for orbital expansion. The results are presented in extensive tables and discussed in detail. The corrections applied are shown to have a significant impact on the accuracy of the room-temperature broadenings determined: 8.9 sq A for the 22.2-GHz line, 11.8 sq A for the 183,3-GHz line, and 10.0 sq A for the 380.2-GHz line, in good agreement with published experimental data. The importance of collisional broadening for the atmospheric transmission of radiation and for remote-sensing applications is indicated.

  3. Fraunhofer-type diffraction patterns of matter-wave scattering of projectiles: Electron transfer in energetic ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Agueny, Hicham

    2015-07-01

    We present results for single and double electron captures in intermediate energies H+ and 2H+ projectiles colliding with a helium target. The processes under investigations are treated using a nonperturbative semiclassical approach in combination with Eikonal approximation to calculate the scattering differential cross sections. The latter reveals pronounced minima and maxima in the scattering angles, in excellent agreement with the recent experimental data. It turns out that the present structure depends strongly on the projectile energy and shows only slight variations with different capture channels. The observed structure demonstrates the analogy of atomic de Broglie's matter-wave scattering with λd B=1.3 -3.2 ×10-3 a.u. and Fraunhofer-type diffraction of light waves.

  4. Space physics educational outreach

    NASA Technical Reports Server (NTRS)

    Copeland, Richard A.

    1995-01-01

    The goal of this Space Physics Educational Outreach project was to develop a laboratory experiment and classroom lecture on Earth's aurora for use in lower division college physics courses, with the particular aim of implementing the experiment and lecture at Saint Mary's College of California. The strategy is to teach physics in the context of an interesting natural phenomenon by investigating the physical principles that are important in Earth's aurora, including motion of charged particles in electric and magnetic fields, particle collisions and chemical reactions, and atomic and molecular spectroscopy. As a by-product, the undergraduate students would develop an appreciation for naturally occurring space physics phenomena.

  5. Effects of weakly coupled and dense quantum plasmas environments on charge exchange and ionization processes in Na+ + Rb(5s) atom collisions

    NASA Astrophysics Data System (ADS)

    Pandey, Mukesh Kumar; Lin, Yen-Chang; Ho, Yew Kam

    2017-02-01

    The effects of weakly coupled or classical and dense quantum plasmas environment on charge exchange and ionization processes in Na+ + Rb(5s) atom collision at keV energy range have been investigated using classical trajectory Monte Carlo (CTMC) method. The interaction of three charged particles are described by the Debye-Hückel screen potential for weakly coupled plasma, whereas exponential cosine-screened Coulomb potential have been used for dense quantum plasma environment and the effects of both conditions on the cross sections are compared. It is found that screening effects on cross sections in high Debye length condition is quite small in both plasma environments. However, enhanced screening effects on cross sections are observed in dense quantum plasmas for low Debye length condition, which becomes more effective while decreasing the Debye length. Also, we have found that our calculated results for plasma-free case are comparable with the available theoretical results. These results are analyzed in light of available theoretical data with the choice of model potentials.

  6. The bond-forming reactions of atomic dications with neutral molecules: formation of ArNH+ and ArN+ from collisions of Ar2+ with NH3.

    PubMed

    Lambert, Natalie; Kearney, Dominic; Kaltsoyannis, Nikolas; Price, Stephen D

    2004-03-24

    An experimental and computational study has been performed to investigate the bond-forming reactivity between Ar(2+) and NH(3). Experimentally, we detect two previously unobserved bond-forming reactions between Ar(2+) and NH(3) forming ArN(+) and ArNH(+). This is the first experimental observation of a triatomic product ion (ArNH(+)) following a chemical reaction of a rare gas dication with a neutral. The intensity of ArNH(+) was found to decrease with increasing collision energy, with a corresponding increase in the intensity of ArN(+), indicating that ArN(+) is formed by the dissociation of ArNH(+). Key features on the potential energy surface for the reaction were calculated quantum chemically using CASSCF and MRCI methods. The calculated reaction mechanism, which takes place on a singlet surface, involves the initial formation of an Ar-N bond to give Ar-NH(3)(2+). This complexation is followed by proton loss via a transition state, and then loss of the two remaining hydrogen atoms in two subsequent activationless steps to give the products (3)ArN(+) + H(+) + 2H. This calculated pathway supports the sequential formation of ArN(+) from ArNH(+), as suggested by the experimental data. The calculations also indicate that no bond-forming pathway exists on the ground triplet surface for this system.

  7. Getting Physical with Your Chemistry: Mechanically Investigating Local Structure and Properties of Surfaces with the Atomic Force Microscope

    ERIC Educational Resources Information Center

    Heinz, William F.; Hoh, Jan H.

    2005-01-01

    Atomic force microscope (AFM) investigates mechanically the chemical properties of individual molecules, surfaces, and materials using suitably designed probes. The current state of the art of AFM in terms of imaging, force measurement, and sample manipulation and its application to physical chemistry is discussed.

  8. Introduction to the Contributions of A. Temkin and R. J. Drachman to Atomic Physics

    NASA Technical Reports Server (NTRS)

    Bhatia, A.K.

    2007-01-01

    Their work, as is the work of most atomic theorists, is concerned with solving the Schroedinger equation accurately for wave function in cases where there is no exact analytical solution. In particular, Temkin is associated with electron scattering from atoms and ions. When he started there already were a number of methods to study the scattering of electrons from atoms.

  9. Collision of Physics and Software in the Monte Carlo Application Toolkit (MCATK)

    SciTech Connect

    Sweezy, Jeremy Ed

    2016-01-21

    The topic is presented in a series of slides organized as follows: MCATK overview, development strategy, available algorithms, problem modeling (sources, geometry, data, tallies), parallelism, miscellaneous tools/features, example MCATK application, recent areas of research, and summary and future work. MCATK is a C++ component-based Monte Carlo neutron-gamma transport software library with continuous energy neutron and photon transport. Designed to build specialized applications and to provide new functionality in existing general-purpose Monte Carlo codes like MCNP, it reads ACE formatted nuclear data generated by NJOY. The motivation behind MCATK was to reduce costs. MCATK physics involves continuous energy neutron & gamma transport with multi-temperature treatment, static eigenvalue (keff and α) algorithms, time-dependent algorithm, and fission chain algorithms. MCATK geometry includes mesh geometries and solid body geometries. MCATK provides verified, unit-test Monte Carlo components, flexibility in Monte Carlo application development, and numerous tools such as geometry and cross section plotters.

  10. Differential scattering cross sections for collisions of 0.5-, 1.5-, and 5.0-keV helium atoms with He, H2, N2, and O2. [for atmospheric processes modeling

    NASA Technical Reports Server (NTRS)

    Newman, J. H.; Smith, K. A.; Stebbings, R. F.; Chen, Y. S.

    1985-01-01

    This paper reports the first results of an experimental program established to provide cross section data for use in modeling various atmospheric processes. Absolute cross sections, differential in the scattering angle, have been measured for collisions of 0.5-, 1.5-, and 5.0-keV helium atoms with He, H2, N2, and O2 at laboratory scattering angles between 0.1 deg and 5 deg. The results are the sums of cross sections for elastic and inelastic scattering of helium atoms; charged collision products are not detected. Integration of the differential cross section data yields integral cross sections consistent with measurements by other workers. The apparatus employs a position-sensitive detector for both primary and scattered particles and uses a short target cell with a large exit aperture to ensure a simple and well-defined apparatus geometry.

  11. Dynamics of carbon-hydrogen and carbon-methyl exchanges in the collision of {sup 3}P atomic carbon with propene

    SciTech Connect

    Lee, Shih-Huang Chen, Wei-Kan; Chin, Chih-Hao; Huang, Wen-Jian

    2013-11-07

    We investigated the dynamics of the reaction of {sup 3}P atomic carbon with propene (C{sub 3}H{sub 6}) at reactant collision energy 3.8 kcal mol{sup −1} in a crossed molecular-beam apparatus using synchrotron vacuum-ultraviolet ionization. Products C{sub 4}H{sub 5}, C{sub 4}H{sub 4}, C{sub 3}H{sub 3}, and CH{sub 3} were observed and attributed to exit channels C{sub 4}H{sub 5} + H, C{sub 4}H{sub 4} + 2H, and C{sub 3}H{sub 3} + CH{sub 3}; their translational-energy distributions and angular distributions were derived from the measurements of product time-of-flight spectra. Following the addition of a {sup 3}P carbon atom to the C=C bond of propene, cyclic complex c-H{sub 2}C(C)CHCH{sub 3} undergoes two separate stereoisomerization mechanisms to form intermediates E- and Z-H{sub 2}CCCHCH{sub 3}. Both the isomers of H{sub 2}CCCHCH{sub 3} in turns decompose to C{sub 4}H{sub 5} + H and C{sub 3}H{sub 3} + CH{sub 3}. A portion of C{sub 4}H{sub 5} that has enough internal energy further decomposes to C{sub 4}H{sub 4} + H. The three exit channels C{sub 4}H{sub 5} + H, C{sub 4}H{sub 4} + 2H, and C{sub 3}H{sub 3} + CH{sub 3} have average translational energy releases 13.5, 3.2, and 15.2 kcal mol{sup −1}, respectively, corresponding to fractions 0.26, 0.41, and 0.26 of available energy deposited to the translational degrees of freedom. The H-loss and 2H-loss channels have nearly isotropic angular distributions with a slight preference at the forward direction particularly for the 2H-loss channel. In contrast, the CH{sub 3}-loss channel has a forward and backward peaked angular distribution with an enhancement at the forward direction. Comparisons with reactions of {sup 3}P carbon atoms with ethene, vinyl fluoride, and vinyl chloride are stated.

  12. A physical approach to reduce nonspecific adhesion in molecular recognition atomic force microscopy.

    PubMed

    Willemsen, O H; Snel, M M; Kuipers, L; Figdor, C G; Greve, J; De Grooth, B G

    1999-02-01

    Atomic force microscopy is one of the few techniques that allow analysis of biological recognition processes at the single-molecule level. A major limitation of this approach is the nonspecific interaction between the force sensor and substrate. We have modeled the nonspecific interaction by looking at the interaction potential between a conical Si3N4 tip with a spherical end face and a mica surface in solution, using DLVO (Derjaguin, Landau, Verwey, Overbeek) theory and numerical calculations. Insertion of the tip-sample potential in a simulation of an approach-retract cycle of the cantilever gives the well-known force-distance curve. Simulating a force-distance curve at low salt concentration predicts a discrete hopping of the tip, caused by thermal fluctuations. This hopping behavior was observed experimentally and gave rise to a novel approach to making measurements in adhesion mode that essentially works in the repulsive regime. The distance between tip and sample will still be small enough to allow spacer-involved specific interactions, and the percentage of nonspecific interactions of the bare tip with the mica is minimized. We have validated this physical model by imaging intercellular adhesion molecule 1 (ICAM-1) antigen with a tip functionalized with anti-ICAM-1 antibody. The measurement demonstrated that a significant decrease in the number of nonspecific interactions was realized, and the topographical image quality and the specific bonding capability of the tip were not affected.

  13. The advanced light source at Lawrence Berkeley laboratory: a new tool for research in atomic physics

    NASA Astrophysics Data System (ADS)

    Schlachter, Alfred S.; Robinson, Arthur L.

    1991-04-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 10 long straight sections available for insertion devices (undulators and wigglers) and 24 high-quality bend-magnet ports. The short pulse width (30-50 ps) will be ideal for time-resolved measurements. Undulators will generate high-brightness partially coherent soft X-ray and ultraviolet (XUV) radiation from below 10 eV to above 2 keV; this radiation is plane polarized. Wigglers and bend magnets will extend the spectrum by generating high fluxes of X-rays to photon energies above 10 keV. The ALS will have an extensive research program in which XUV radiation is used to study matter in all its varied gaseous, liquid, and solid forms. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy), and in biology, such as X-ray microscopy with element-specific sensitivity; the high flux will allow measurements in atomic physics and chemistry to be made with tenuous gas-phase targets. Technological applications could include lithography and nano-fabrication.

  14. Protein model refinement using an optimized physics-based all-atom force field.

    PubMed

    Jagielska, Anna; Wroblewska, Liliana; Skolnick, Jeffrey

    2008-06-17

    One of the greatest challenges in protein structure prediction is the refinement of low-resolution predicted models to high-resolution structures that are close to the native state. Although contemporary structure prediction methods can assemble the correct topology for a large fraction of protein domains, such approximate models are often not of the resolution required for many important applications, including studies of reaction mechanisms and virtual ligand screening. Thus, the development of a method that could bring those structures closer to the native state is of great importance. We recently optimized the relative weights of the components of the Amber ff03 potential on a large set of decoy structures to create a funnel-shaped energy landscape with the native structure at the global minimum. Such an energy function might be able to drive proteins toward their native structure. In this work, for a test set of 47 proteins, with 100 decoy structures per protein that have a range of structural similarities to the native state, we demonstrate that our optimized potential can drive protein models closer to their native structure. Comparing the lowest-energy structure from each trajectory with the starting decoy, structural improvement is seen for 70% of the models on average. The ability to do such systematic structural refinements by using a physics-based all-atom potential represents a promising approach to high-resolution structure prediction.

  15. Atomic and molecular physics of plasma-based environmental technologies for abatement of volatile organic compounds

    SciTech Connect

    Penetrante, B.M.; Hsiao, M.C.; Bardsley, J.N.; Merritt, B.T.; Vogtlin, G.E.; Kuthi, A.; Burkhart, C.P.; Bayless, J.R.

    1996-08-01

    Non-thermal plasma techniques represent a new generation of air emission control technology that potentially could treat large-volume emissions containing dilute concentrations of volatile organic compounds (VOCs). In order to apply non-thermal plasmas in an industrial scale, it is important to establish the electrical power requirements and byproducts of the process. There is a need for reliable data concerning the primary decomposition mechanisms and subsequent chemical kinetics associated with non-thermal processing of VOCs. There are many basic atomic and molecular physics issues that are essential in evaluating the economic performance of non- thermal plasma reactors. These studies are important in understanding how the input electrical power is dissipated in the plasma and how efficiently it is converted to the production of the plasma species (radicals, ions, or electrons) responsible for the decomposition of the VOCs. This paper will present results from the basic experimental and theoretical studies aimed at identifying the reaction mechanisms responsible for the primary decomposition of various types of VOCs.

  16. Comments on alternative calculations of the broadening of spectral lines of neutral sodium by H-atom collisions

    NASA Astrophysics Data System (ADS)

    Barklem, P. S.; O'Mara, B. J.

    2001-12-01

    With the exception of the sodium D-lines, recent calculations of line broadening cross sections for several multiplets of sodium by Leininger et al (Leininger T, Gadéa F X and Dickinson A 2000 J. Phys. B: At. Mol. Opt. Phys. 33 1805) are in substantial disagreement with cross sections interpolated from the tables of Anstee and O'Mara (Anstee and O'Mara 1995 Mon. Not. R. Astron. Soc. 276 859) and Barklem and O'Mara (Barklem P S and O'Mara B J 1997 Mon. Not. R. Astron. Soc. 290 102). The discrepancy is as large as a factor of 3 for the 3p-4d multiplet. The two theories are tested by using the results of each to synthesize lines in the solar spectrum. It is found that generally the data from the theory of Anstee, Barklem and O'Mara produce the best match to the observed solar spectrum. It is found, using a simple model for reflection of the optical electron by the potential barrier between the two atoms, that the reflection coefficient is too large for avoided crossings with the upper states of subordinate lines to contribute to line broadening, supporting the neglect of avoided ionic crossings by Anstee, Barklem and O'Mara for these lines. The large discrepancies between the two sets of calculations is a result of an approximate treatment of avoided ionic crossings for these lines by Leininger et al (Leininger T, Gadéa F X and Dickinson A 2000 J. Phys. B: At. Mol. Opt. Phys. 33 1805).

  17. Folding peptides and proteins with all-atom physics: methods and applications

    NASA Astrophysics Data System (ADS)

    Shell, M. Scott

    2008-03-01

    Computational methods offer powerful tools for investigating proteins and peptides at the molecular-level; however, it has proven challenging to reproduce the long time scale folding processes of these molecules at a level that is both faithful to the atomic driving forces and attainable with modern commodity cluster computing. Alternatively, the past decade has seen significant progress in using bioinformatics-based approaches to infer the three dimensional native structures of proteins, drawing upon extensive knowledge databases of known protein structures [1]. These methods work remarkably well when a homologous protein can be found to provide a structural template for a candidate sequence. However, in cases where homology to database proteins is low, where the folding pathway is of interest, or where conformational flexibility is substantial---as in many emerging protein and peptide technologies---bioinformatics methods perform poorly. There is therefore great interest in seeing purely physics-based approaches succeed. We discuss a purely physics-based, database-free folding method, relying on proper thermal sampling (replica exchange molecular dynamics) and molecular potential energy functions. In order to surmount the tremendous computational demands of all-atom folding simulations, our approach implements a conformational search strategy based on a putative protein folding mechanism called zipping and assembly [2-4]. That is, we explicitly seek out potential folding pathways inferred from short simulations, and iteratively pursue all such routes by coaxing a polypeptide chain along them. The method is called the Zipping and Assembly Method (ZAM) and it works in two parts: (1) the full polypeptide chain is broken into small fragments that are first simulated independently and then successively re-assembled into larger segments with further sampling, and (2) consistently stable structure in fragments is detected and locked into place, in order to avoid re

  18. Search for new physics with a monojet and missing transverse energy in pp collisions at √s = 7 TeV.

    PubMed

    Chatrchyan, S; Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Fabjan, C; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kiesenhofer, W; Krammer, M; Liko, D; Mikulec, I; Pernicka, M; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Teischinger, F; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C-E; Mossolov, V; Shumeiko, N; Gonzalez, J Suarez; Bansal, S; Benucci, L; De Wolf, E A; Janssen, X; Maes, J; Maes, T; Mucibello, L; Ochesanu, S; Roland, B; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Blekman, F; Blyweert, S; D'Hondt, J; Devroede, O; Suarez, R Gonzalez; Kalogeropoulos, A; Maes, M; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Gay, A P R; Hammad, G H; Hreus, T; Marage, P E; Thomas, L; Velde, C Vander; Vanlaer, P; Adler, V; Cimmino, A; Costantini, S; Grunewald, M; Klein, B; Lellouch, J; Marinov, A; Mccartin, J; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Walsh, S; Zaganidis, N; Basegmez, S; Bruno, G; Caudron, J; Ceard, L; Gil, E Cortina; De Favereau De Jeneret, J; Delaere, C; Favart, D; Giammanco, A; Grégoire, G; Hollar, J; Lemaitre, V; Liao, J; Militaru, O; Nuttens, C; Ovyn, S; Pagano, D; Pin, A; Piotrzkowski, K; Schul, N; Beliy, N; Caebergs, T; Daubie, E; Alves, G A; Brito, L; De Jesus Damiao, D; Pol, M E; Souza, M H G; Aldá Júnior, W L; Carvalho, W; Da Costa, E M; Martins, C De Oliveira; Fonseca De Souza, S; Mundim, L; Nogima, H; Oguri, V; Prado Da Silva, W L; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Bernardes, C A; Dias, F A; Tomei, T R Fernandez Perez; Gregores, E M; Lagana, C; Marinho, F; Mercadante, P G; Novaes, S F; Padula, Sandra S; Darmenov, N; Genchev, V; Iaydjiev, P; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Tcholakov, V; Trayanov, R; Dimitrov, A; Hadjiiska, R; Karadzhinova, A; Kozhuharov, V; Litov, L; Mateev, M; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Jiang, C H; Liang, D; Liang, S; Meng, X; Tao, J; Wang, J; Wang, J; Wang, X; Wang, Z; Xiao, H; Xu, M; Zang, J; Zhang, Z; Ban, Y; Guo, S; Guo, Y; Li, W; Mao, Y; Qian, S J; Teng, H; Zhu, B; Zou, W; Cabrera, A; Moreno, B Gomez; Rios, A A Ocampo; Oliveros, A F Osorio; Sanabria, J C; Godinovic, N; Lelas, D; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Attikis, A; Galanti, M; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Finger, M; Finger, M; Awad, A; Khalil, S; Radi, A; Hektor, A; Kadastik, M; Müntel, M; Raidal, M; Rebane, L; Tiko, A; Azzolini, V; Eerola, P; Fedi, G; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Ungaro, D; Wendland, L; Banzuzi, K; Karjalainen, A; Korpela, A; Tuuva, T; Sillou, D; Besancon, M; Choudhury, S; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Shreyber, I; Titov, M; Verrecchia, P; Baffioni, S; Beaudette, F; Benhabib, L; Bianchini, L; Bluj, M; Broutin, C; Busson, P; Charlot, C; Dahms, T; Dobrzynski, L; Elgammal, S; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Mironov, C; Ochando, C; Paganini, P; Sabes, D; Salerno, R; Sirois, Y; Thiebaux, C; Wyslouch, B; Zabi, A; Agram, J-L; Andrea, J; Bloch, D; Bodin, D; Brom, J-M; Cardaci, M; Chabert, E C; Collard, C; Conte, E; Drouhin, F; Ferro, C; Fontaine, J-C; Gelé, D; Goerlach, U; Greder, S; Juillot, P; Karim, M; Le Bihan, A-C; Mikami, Y; Van Hove, P; Fassi, F; Mercier, D; Baty, C; Beauceron, S; Beaupere, N; Bedjidian, M; Bondu, O; Boudoul, G; Boumediene, D; Brun, H; Chasserat, J; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Mirabito, L; Perries, S; Sordini, V; Tosi, S; Tschudi, Y; Verdier, P; Lomidze, D; Anagnostou, G; Beranek, S; Edelhoff, M; Feld, L; Heracleous, N; Hindrichs, O; Jussen, R; Klein, K; Merz, J; Mohr, N; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Sprenger, D; Weber, H; Weber, M; Wittmer, B; Ata, M; Dietz-Laursonn, E; Erdmann, M; Hebbeker, T; Hinzmann, A; Hoepfner, K; Klimkovich, T; Klingebiel, D; Kreuzer, P; Lanske, D; Lingemann, J; Magass, C; Merschmeyer, M; Meyer, A; Papacz, P; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Steggemann, J; Teyssier, D; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Ahmad, W Haj; Heydhausen, D; Hoehle, F; Kargoll, B; Kress, T; Kuessel, Y; Linn, A; Nowack, A; Perchalla, L; Pooth, O; Rennefeld, J; Sauerland, P; Stahl, A; Thomas, M; Tornier, D; Zoeller, M H; Martin, M Aldaya; Behrenhoff, W; Behrens, U; Bergholz, M; Bethani, A; Borras, K; Cakir, A; Campbell, A; Castro, E; Dammann, D; Eckerlin, G; Eckstein, D; Flossdorf, A; Flucke, G; Geiser, A; Hauk, J; Jung, H; Kasemann, M; Katkov, I; Katsas, P; Kleinwort, C; Kluge, H; Knutsson, A; Krämer, M; Krücker, D; Kuznetsova, E; Lange, W; Lohmann, W; Mankel, R; Marienfeld, M; Melzer-Pellmann, I-A; Meyer, A B; Mnich, J; Mussgiller, A; Olzem, J; Petrukhin, A; Pitzl, D; Raspereza, A; Raval, A; Rosin, M; Schmidt, R; Schoerner-Sadenius, T; Sen, N; Spiridonov, A; Stein, M; Tomaszewska, J; Walsh, R; Wissing, C; Autermann, C; Blobel, V; Bobrovskyi, S; Draeger, J; Enderle, H; Gebbert, U; Görner, M; Kaschube, K; Kaussen, G; Kirschenmann, H; Klanner, R; Lange, J; Mura, B; Naumann-Emme, S; Nowak, F; Pietsch, N; Sander, C; Schettler, H; Schleper, P; Schlieckau, E; Schröder, M; Schum, T; Schwandt, J; Stadie, H; Steinbrück, G; Thomsen, J; Barth, C; Bauer, J; Berger, J; Buege, V; Chwalek, T; De Boer, W; Dierlamm, A; Dirkes, G; Feindt, M; Gruschke, J; Hackstein, C; Hartmann, F; Heinrich, M; Held, H; Hoffmann, K H; Honc, S; Komaragiri, J R; Kuhr, T; Martschei, D; Mueller, S; Müller, Th; Niegel, M; Oberst, O; Oehler, A; Ott, J; Peiffer, T; Quast, G; Rabbertz, K; Ratnikov, F; Ratnikova, N; Renz, M; Saout, C; Scheurer, A; Schieferdecker, P; Schilling, F-P; Schott, G; Simonis, H J; Stober, F M; Troendle, D; Wagner-Kuhr, J; Weiler, T; Zeise, M; Zhukov, V; Ziebarth, E B; Daskalakis, G; Geralis, T; Kesisoglou, S; Kyriakis, A; Loukas, D; Manolakos, I; Markou, A; Markou, C; Mavrommatis, C; Ntomari, E; Petrakou, E; Gouskos, L; Mertzimekis, T J; Panagiotou, A; Stiliaris, E; Evangelou, I; Foudas, C; Kokkas, P; Manthos, N; Papadopoulos, I; Patras, V; Triantis, F A; Aranyi, A; Bencze, G; Boldizsar, L; Hajdu, C; Hidas, P; Horvath, D; Kapusi, A; Krajczar, K; Sikler, F; Veres, G I; Vesztergombi, G; Beni, N; Molnar, J; Palinkas, J; Szillasi, Z; Veszpremi, V; Raics, P; Trocsanyi, Z L; Ujvari, B; Beri, S B; Bhatnagar, V; Dhingra, N; Gupta, R; Jindal, M; Kaur, M; Kohli, J M; Mehta, M Z; Nishu, N; Saini, L K; Sharma, A; Singh, A P; Singh, J; Singh, S P; Ahuja, S; Choudhary, B C; Gupta, P; Jain, S; Jain, S; Kumar, A; Kumar, A; Naimuddin, M; Ranjan, K; Shivpuri, R K; Banerjee, S; Bhattacharya, S; Dutta, S; Gomber, B; Khurana, R; Sarkar, S; Choudhury, R K; Dutta, D; Kailas, S; Kumar, V; Mehta, P; Mohanty, A K; Pant, L M; Shukla, P; Aziz, T; Guchait, M; Gurtu, A; Maity, M; Majumder, D; Majumder, G; Mazumdar, K; Mohanty, G B; Saha, A; Sudhakar, K; Wickramage, N; Banerjee, S; Dugad, S; Mondal, N K; Arfaei, H; Bakhshiansohi, H; Etesami, S M; Fahim, A; Hashemi, M; Jafari, A; Khakzad, M; Mohammadi, A; Najafabadi, M Mohammadi; Mehdiabadi, S Paktinat; Safarzadeh, B; Zeinali, M; Abbrescia, M; Barbone, L; Calabria, C; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Fiore, L; Iaselli, G; Lusito, L; Maggi, G; Maggi, M; Manna, N; Marangelli, B; My, S; Nuzzo, S; Pacifico, N; Pierro, G A; Pompili, A; Pugliese, G; Romano, F; Roselli, G; Selvaggi, G; Silvestris, L; Trentadue, R; Tupputi, S; Zito, G; Abbiendi, G; Benvenuti, A C; Bonacorsi, D; Braibant-Giacomelli, S; Brigliadori, L; Capiluppi, P; Castro, A; Cavallo, F R; Cuffiani, M; Dallavalle, G M; Fabbri, F; Fanfani, A; Fasanella, D; Giacomelli, P; Giunta, M; Grandi, C; Marcellini, S; Masetti, G; Meneghelli, M; Montanari, A; Navarria, F L; Odorici, F; Perrotta, A; Primavera, F; Rossi, A M; Rovelli, T; Siroli, G; Travaglini, R; Albergo, S; Cappello, G; Chiorboli, M; Costa, S; Tricomi, A; Tuve, C; Barbagli, G; Ciulli, V; Civinini, C; D'Alessandro, R; Focardi, E; Frosali, S; Gallo, E; Gonzi, S; Lenzi, P; Meschini, M; Paoletti, S; Sguazzoni, G; Tropiano, A; Benussi, L; Bianco, S; Colafranceschi, S; Fabbri, F; Piccolo, D; Fabbricatore, P; Musenich, R; Benaglia, A; De Guio, F; Di Matteo, L; Gennai, S; Ghezzi, A; Malvezzi, S; Martelli, A; Massironi, A; Menasce, D; Moroni, L; Paganoni, M; Pedrini, D; Ragazzi, S; Redaelli, N; Sala, S; Tabarelli de Fatis, T; Buontempo, S; Montoya, C A Carrillo; Cavallo, N; De Cosa, A; Fabozzi, F; Iorio, A O M; Lista, L; Merola, M; Paolucci, P; Azzi, P; Bacchetta, N; Bellan, P; Biasotto, M; Bisello, D; Branca, A; Carlin, R; Checchia, P; Dorigo, T; Gasparini, F; Gozzelino, A; Gulmini, M; Lacaprara, S; Lazzizzera, I; Margoni, M; Maron, G; Meneguzzo, A T; Nespolo, M; Perrozzi, L; Pozzobon, N; Ronchese, P; Simonetto, F; Torassa, E; Tosi, M; Triossi, A; Vanini, S; Zotto, P; Zumerle, G; Baesso, P; Berzano, U; Ratti, S P; Riccardi, C; Torre, P; Vitulo, P; Viviani, C; Biasini, M; Bilei, G M; Caponeri, B; Fanò, L; Lariccia, P; Lucaroni, A; Mantovani, G; Menichelli, M; Nappi, A; Romeo, F; Santocchia, A; Taroni, S; Valdata, M; Azzurri, P; Bagliesi, G; Bernardini, J; Boccali, T; Broccolo, G; Castaldi, R; D'Agnolo, R T; Dell'Oso, R; Fiori, F; Foà, L; Giassi, A; Kraan, A; Ligabue, F; Lomtadze, T; Martini, L; Messineo, A; Palla, F; Segneri, G; Serban, A T; Spagnolo, P; Tenchini, R; Tonelli, G; Venturi, A; Verdini, P G; Barone, L; Cavallari, F; Del Re, D; Di Marco, E; Diemoz, M; Franci, D; Grassi, M; Longo, E; Meridiani, P; Nourbakhsh, S; Organtini, G; Pandolfi, F; Paramatti, R; Rahatlou, S; Rovelli, C; Amapane, N; Arcidiacono, R; Argiro, S; Arneodo, M; Biino, C; Botta, C; Cartiglia, N; Castello, R; Costa, M; Demaria, N; Graziano, A; Mariotti, C; Marone, M; Maselli, S; Migliore, E; Mila, G; Monaco, V; Musich, M; Obertino, M M; Pastrone, N; Pelliccioni, M; Potenza, A; Romero, A; Ruspa, M; Sacchi, R; Sola, V; Solano, A; Staiano, A; Pereira, A Vilela; Belforte, S; Cossutti, F; Della Ricca, G; Gobbo, B; Montanino, D; Penzo, A; Heo, S G; Nam, S K; Chang, S; Chung, J; Kim, D H; Kim, G N; Kim, J E; Kong, D J; Park, H; Ro, S R; Son, D; Son, D C; Son, T; Kim, Zero; Kim, J Y; Song, S; Choi, S; Hong, B; Jo, M; Kim, H; Kim, J H; Kim, T J; Lee, K S; Moon, D H; Park, S K; Sim, K S; Choi, M; Kang, S; Kim, H; Park, C; Park, I C; Park, S; Ryu, G; Choi, Y; Choi, Y K; Goh, J; Kim, M S; Lee, J; Lee, S; Seo, H; Yu, I; Bilinskas, M J; Grigelionis, I; Janulis, M; Martisiute, D; Petrov, P; Sabonis, T; Castilla-Valdez, H; De La Cruz-Burelo, E; Heredia-de La Cruz, I; Lopez-Fernandez, R; Villalba, R Magaña; Sánchez-Hernández, A; Villasenor-Cendejas, L M; Moreno, S Carrillo; Valencia, F Vazquez; Ibarguen, H A Salazar; Linares, E Casimiro; Pineda, A Morelos; Reyes-Santos, M A; Krofcheck, D; Tam, J; Butler, P H; Doesburg, R; Silverwood, H; Ahmad, M; Ahmed, I; Asghar, M I; Hoorani, H R; Khan, W A; Khurshid, T; Qazi, S; Brona, G; Cwiok, M; Dominik, W; Doroba, K; Kalinowski, A; Konecki, M; Krolikowski, J; Frueboes, T; Gokieli, R; Górski, M; Kazana, M; Nawrocki, K; Romanowska-Rybinska, K; Szleper, M; Wrochna, G; Zalewski, P; Almeida, N; Bargassa, P; David, A; Faccioli, P; Parracho, P G Ferreira; Gallinaro, M; Musella, P; Nayak, A; Pela, J; Ribeiro, P Q; Seixas, J; Varela, J; Afanasiev, S; Belotelov, I; Bunin, P; Golutvin, I; Karjavin, V; Kozlov, G; Lanev, A; Moisenz, P; Palichik, V; Perelygin, V; Savina, M; Shmatov, S; Smirnov, V; Volodko, A; Zarubin, A; Golovtsov, V; Ivanov, Y; Kim, V; Levchenko, P; Murzin, V; Oreshkin, V; Smirnov, I; Sulimov, V; Uvarov, L; Vavilov, S; Vorobyev, A; Vorobyev, An; Andreev, Yu; Dermenev, A; Gninenko, S; Golubev, N; Kirsanov, M; Krasnikov, N; Matveev, V; Pashenkov, A; Toropin, A; Troitsky, S; Epshteyn, V; Gavrilov, V; Kaftanov, V; Kossov, M; Krokhotin, A; Lychkovskaya, N; Popov, V; Safronov, G; Semenov, S; Stolin, V; Vlasov, E; Zhokin, A; Boos, E; Dubinin, M; Dudko, L; Ershov, A; Gribushin, A; Kodolova, O; Lokhtin, I; Markina, A; Obraztsov, S; Perfilov, M; Petrushanko, S; Sarycheva, L; Savrin, V; Snigirev, A; Andreev, V; Azarkin, M; Dremin, I; Kirakosyan, M; Leonidov, A; Rusakov, S V; Vinogradov, A; Azhgirey, I; Bayshev, I; Bitioukov, S; Grishin, V; Kachanov, V; Konstantinov, D; Korablev, A; Krychkine, V; Petrov, V; Ryutin, R; Sobol, A; Tourtchanovitch, L; Troshin, S; Tyurin, N; Uzunian, A; Volkov, A; Adzic, P; Djordjevic, M; Krpic, D; Milosevic, J; Aguilar-Benitez, M; Maestre, J Alcaraz; Arce, P; Battilana, C; Calvo, E; Cepeda, M; Cerrada, M; Llatas, M Chamizo; Colino, N; De La Cruz, B; Peris, A Delgado; Pardos, C Diez; Vázquez, D Domínguez; Bedoya, C Fernandez; Ramos, J P Fernández; Ferrando, A; Flix, J; Fouz, M C; Garcia-Abia, P; Lopez, O Gonzalez; Lopez, S Goy; Hernandez, J M; Josa, M I; Merino, G; Pelayo, J Puerta; Redondo, I; Romero, L; Santaolalla, J; Soares, M S; Willmott, C; Albajar, C; Codispoti, G; de Trocóniz, J F; Cuevas, J; Menendez, J Fernandez; Folgueras, S; Caballero, I Gonzalez; Iglesias, L Lloret; Garcia, J M Vizan; Cifuentes, J A Brochero; Cabrillo, I J; Calderon, A; Chuang, S H; Campderros, J Duarte; Felcini, M; Fernandez, M; Gomez, G; Sanchez, J Gonzalez; Jorda, C; Pardo, P Lobelle; Virto, A Lopez; Marco, J; Marco, R; Rivero, C Martinez; Matorras, F; Sanchez, F J Munoz; Gomez, J Piedra; Rodrigo, T; Rodríguez-Marrero, A Y; Ruiz-Jimeno, A; Scodellaro, L; Sanudo, M Sobron; Vila, I; Cortabitarte, R Vilar; Abbaneo, D; Auffray, E; Auzinger, G; Baillon, P; Ball, A H; Barney, D; Bell, A J; Benedetti, D; Bernet, C; Bialas, W; Bloch, P; Bocci, A; Bolognesi, S; Bona, M; Breuker, H; Bunkowski, K; Camporesi, T; Cerminara, G; Christiansen, T; Perez, J A Coarasa; Curé, B; D'Enterria, D; De Roeck, A; Di Guida, S; Dupont-Sagorin, N; Elliott-Peisert, A; Frisch, B; Funk, W; Gaddi, A; Georgiou, G; Gerwig, H; Gigi, D; Gill, K; Giordano, D; Glege, F; Garrido, R Gomez-Reino; Gouzevitch, M; Govoni, P; Gowdy, S; Guiducci, L; Hansen, M; Hartl, C; Harvey, J; Hegeman, J; Hegner, B; Hoffmann, H F; Honma, A; Innocente, V; Janot, P; Kaadze, K; Karavakis, E; Lecoq, P; Lourenço, C; Mäki, T; Malberti, M; Malgeri, L; Mannelli, M; Masetti, L; Maurisset, A; Meijers, F; Mersi, S; Meschi, E; Moser, R; Mozer, M U; Mulders, M; Nesvold, E; Nguyen, M; Orimoto, T; Orsini, L; Perez, E; Petrilli, A; Pfeiffer, A; Pierini, M; Pimiä, M; Piparo, D; Polese, G; Racz, A; Antunes, J Rodrigues; Rolandi, G; Rommerskirchen, T; Rovere, M; Sakulin, H; Schäfer, C; Schwick, C; Segoni, I; Sharma, A; Siegrist, P; Simon, M; Sphicas, P; Spiropulu, M; Stoye, M; Tropea, P; Tsirou, A; Vichoudis, P; Voutilainen, M; Zeuner, W D; Bertl, W; Deiters, K; Erdmann, W; Gabathuler, K; Horisberger, R; Ingram, Q; Kaestli, H C; König, S; Kotlinski, D; Langenegger, U; Meier, F; Renker, D; Rohe, T; Sibille, J; Starodumov, A; Bäni, L; Bortignon, P; Caminada, L; Chanon, N; Chen, Z; Cittolin, S; Dissertori, G; Dittmar, M; Eugster, J; Freudenreich, K; Grab, C; Hintz, W; Lecomte, P; Lustermann, W; Marchica, C; Ruiz del Arbol, P Martinez; Milenovic, P; Moortgat, F; Nägeli, C; Nef, P; Nessi-Tedaldi, F; Pape, L; Pauss, F; Punz, T; Rizzi, A; Ronga, F J; Rossini, M; Sala, L; Sanchez, A K; Sawley, M-C; Stieger, B; Tauscher, L; Thea, A; Theofilatos, K; Treille, D; Urscheler, C; Wallny, R; Weber, M; Wehrli, L; Weng, J; Aguilo, E; Amsler, C; Chiochia, V; De Visscher, S; Favaro, C; Rikova, M Ivova; Mejias, B Millan; Otiougova, P; Regenfus, C; Robmann, P; Schmidt, A; Snoek, H; Chang, Y H; Chen, K H; Kuo, C M; Li, S W; Lin, W; Liu, Z K; Lu, Y J; Mekterovic, D; Volpe, R; Wu, J H; Yu, S S; Bartalini, P; Chang, P; Chang, Y H; Chang, Y W; Chao, Y; Chen, K F; Hou, W-S; Hsiung, Y; Kao, K Y; Lei, Y J; Lu, R-S; Shiu, J G; Tzeng, Y M; Wang, M; Adiguzel, A; Bakirci, M N; Cerci, S; Dozen, C; Dumanoglu, I; Eskut, E; Girgis, S; Gokbulut, G; Hos, I; Kangal, E E; Topaksu, A Kayis; Onengut, G; Ozdemir, K; Ozturk, S; Polatoz, A; Sogut, K; Cerci, D Sunar; Tali, B; Topakli, H; Uzun, D; Vergili, L N; Vergili, M; Akin, I V; Aliev, T; Bilin, B; Bilmis, S; Deniz, M; Gamsizkan, H; Guler, A M; Ocalan, K; Ozpineci, A; Serin, M; Sever, R; Surat, U E; Yildirim, E; Zeyrek, M; Deliomeroglu, M; Demir, D; Gülmez, E; Isildak, B; Kaya, M; Kaya, O; Ozbek, M; Ozkorucuklu, S; Sonmez, N; Levchuk, L; Bostock, F; Brooke, J J; Cheng, T L; Clement, E; Cussans, D; Frazier, R; Goldstein, J; Grimes, M; Hansen, M; Hartley, D; Heath, G P; Heath, H F; Kreczko, L; Metson, S; Newbold, D M; Nirunpong, K; Poll, A; Senkin, S; Smith, V J; Ward, S; Basso, L; Bell, K W; Belyaev, A; Brew, C; Brown, R M; Camanzi, B; Cockerill, D J A; Coughlan, J A; Harder, K; Harper, S; Jackson, J; Kennedy, B W; Olaiya, E; Petyt, D; Radburn-Smith, B C; Shepherd-Themistocleous, C H; Tomalin, I R; Womersley, W J; Worm, S D; Bainbridge, R; Ball, G; Ballin, J; Beuselinck, R; Buchmuller, O; Colling, D; Cripps, N; Cutajar, M; Davies, G; Della Negra, M; Ferguson, W; Fulcher, J; Futyan, D; Gilbert, A; Bryer, A Guneratne; Hall, G; Hatherell, Z; Hays, J; Iles, G; Jarvis, M; Karapostoli, G; Lyons, L; MacEvoy, B C; Magnan, A-M; Marrouche, J; Mathias, B; Nandi, R; Nash, J; Nikitenko, A; Papageorgiou, A; Pesaresi, M; Petridis, K; Pioppi, M; Raymond, D M; Rogerson, S; Rompotis, N; Rose, A; Ryan, M J; Seez, C; Sharp, P; Sparrow, A; Tapper, A; Tourneur, S; Acosta, M Vazquez; Virdee, T; Wakefield, S; Wardle, N; Wardrope, D; Whyntie, T; Barrett, M; Chadwick, M; Cole, J E; Hobson, P R; Khan, A; Kyberd, P; Leslie, D; Martin, W; Reid, I D; Teodorescu, L; Hatakeyama, K; Liu, H; Henderson, C; Bose, T; Jarrin, E Carrera; Fantasia, C; Heister, A; St John, J; Lawson, P; Lazic, D; Rohlf, J; Sperka, D; Sulak, L; Avetisyan, A; Bhattacharya, S; Chou, J P; Cutts, D; Ferapontov, A; Heintz, U; Jabeen, S; Kukartsev, G; Landsberg, G; Luk, M; Narain, M; Nguyen, D; Segala, M; Sinthuprasith, T; Speer, T; Tsang, K V; Breedon, R; Breto, G; Calderon De La Barca Sanchez, M; Chauhan, S; Chertok, M; Conway, J; Cox, P T; Dolen, J; Erbacher, R; Friis, E; Ko, W; Kopecky, A; Lander, R; Liu, H; Maruyama, S; Miceli, T; Nikolic, M; Pellett, D; Robles, J; Salur, S; Schwarz, T; Searle, M; Smith, J; Squires, M; Tripathi, M; Sierra, R Vasquez; Veelken, C; Andreev, V; Arisaka, K; Cline, D; Cousins, R; Deisher, A; Duris, J; Erhan, S; Farrell, C; Hauser, J; Ignatenko, M; Jarvis, C; Plager, C; Rakness, G; Schlein, P; Tucker, J; Valuev, V; Babb, J; Chandra, A; Clare, R; Ellison, J; Gary, J W; Giordano, F; Hanson, G; Jeng, G Y; Kao, S C; Liu, F; Liu, H; Long, O R; Luthra, A; Nguyen, H; Shen, B C; Stringer, R; Sturdy, J; Sumowidagdo, S; Wilken, R; Wimpenny, S; Andrews, W; Branson, J G; Cerati, G B; Evans, D; Golf, F; Holzner, A; Kelley, R; Lebourgeois, M; Letts, J; Mangano, B; Padhi, S; Palmer, C; Petrucciani, G; Pi, H; Pieri, M; Ranieri, R; Sani, M; Sharma, V; Simon, S; Sudano, E; Tadel, M; Tu, Y; Vartak, A; Wasserbaech, S; Würthwein, F; Yagil, A; Yoo, J; Barge, D; Bellan, R; Campagnari, C; D'Alfonso, M; Danielson, T; Flowers, K; Geffert, P; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lowette, S; Mccoll, N; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; Vlimant, J R; Apresyan, A; Bornheim, A; Bunn, J; Chen, Y; Gataullin, M; Ma, Y; Mott, A; Newman, H B; Rogan, C; Shin, K; Timciuc, V; Traczyk, P; Veverka, J; Wilkinson, R; Yang, Y; Zhu, R Y; Akgun, B; Carroll, R; Ferguson, T; Iiyama, Y; Jang, D W; Jun, S Y; Liu, Y F; Paulini, M; Russ, J; Vogel, H; Vorobiev, I; Cumalat, J P; Dinardo, M E; Drell, B R; Edelmaier, C J; Ford, W T; Gaz, A; Heyburn, B; Lopez, E Luiggi; Nauenberg, U; Smith, J G; Stenson, K; Ulmer, K A; Wagner, S R; Zang, S L; Agostino, L; Alexander, J; Cassel, D; Chatterjee, A; Das, S; Eggert, N; Gibbons, L K; Heltsley, B; Hopkins, W; Khukhunaishvili, A; Kreis, B; Kaufman, G Nicolas; Patterson, J R; Puigh, D; Ryd, A; Salvati, E; Shi, X; Sun, W; Teo, W D; Thom, J; Thompson, J; Vaughan, J; Weng, Y; Winstrom, L; Wittich, P; Biselli, A; Cirino, G; Winn, D; Abdullin, S; Albrow, M; Anderson, J; Apollinari, G; Atac, M; Bakken, J A; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Bloch, I; Borcherding, F; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Cihangir, S; Cooper, W; Eartly, D P; Elvira, V D; Esen, S; Fisk, I; Freeman, J; Gao, Y; Gottschalk, E; Green, D; Gunthoti, K; Gutsche, O; Hanlon, J; Harris, R M; Hirschauer, J; Hooberman, B; Jensen, H; Johnson, M; Joshi, U; Khatiwada, R; Klima, B; Kousouris, K; Kunori, S; Kwan, S; Leonidopoulos, C; Limon, P; Lincoln, D; Lipton, R; Lykken, J; Maeshima, K; Marraffino, J M; Mason, D; McBride, P; Miao, T; Mishra, K; Mrenna, S; Musienko, Y; Newman-Holmes, C; O'Dell, V; Pordes, R; Prokofyev, O; Saoulidou, N; Sexton-Kennedy, E; Sharma, S; Spalding, W J; Spiegel, L; Tan, P; Taylor, L; Tkaczyk, S; Uplegger, L; Vaandering, E W; Vidal, R; Whitmore, J; Wu, W; Yang, F; Yumiceva, F; Yun, J C; Acosta, D; Avery, P; Bourilkov, D; Chen, M; De Gruttola, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fisher, M; Fu, Y; Furic, I K; Gartner, J; Kim, B; Konigsberg, J; Korytov, A; Kropivnitskaya, A; Kypreos, T; Matchev, K; Mitselmakher, G; Muniz, L; Prescott, C; Remington, R; Schmitt, M; Scurlock, B; Sellers, P; Skhirtladze, N; Snowball, M; Wang, D; Yelton, J; Zakaria, M; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Mesa, D; Rodriguez, J L; Adams, T; Askew, A; Bochenek, J; Chen, J; Diamond, B; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prosper, H; Quertenmont, L; Sekmen, S; Veeraraghavan, V; Baarmand, M M; Dorney, B; Guragain, S; Hohlmann, M; Kalakhety, H; Ralich, R; Vodopiyanov, I; Adams, M R; Anghel, I M; Apanasevich, L; Bai, Y; Bazterra, V E; Betts, R R; Callner, J; Cavanaugh, R; Dragoiu, C; Gauthier, L; Gerber, C E; Hofman, D J; Khalatyan, S; Kunde, G J; Lacroix, F; Malek, M; O'Brien, C; Silkworth, C; Silvestre, C; Smoron, A; Strom, D; Varelas, N; Akgun, U; Albayrak, E A; Bilki, B; Clarida, W; Duru, F; Lae, C K; McCliment, E; Merlo, J-P; Mermerkaya, H; Mestvirishvili, A; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Eskew, C; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Hu, G; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Whitbeck, A; Baringer, P; Bean, A; Benelli, G; Grachov, O; Kenny, R P; Murray, M; Noonan, D; Sanders, S; Wood, J S; Zhukova, V; Barfuss, A F; Bolton, T; Chakaberia, I; Ivanov, A; Khalil, S; Makouski, M; Maravin, Y; Shrestha, S; Svintradze, I; Wan, Z; Gronberg, J; Lange, D; Wright, D; Baden, A; Boutemeur, M; Eno, S C; Ferencek, D; Gomez, J A; Hadley, N J; Kellogg, R G; Kirn, M; Lu, Y; Mignerey, A C; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; Dutta, V; Everaerts, P; Ceballos, G Gomez; Goncharov, M; Hahn, K A; Harris, P; Kim, Y; Klute, M; Lee, Y-J; Li, W; Loizides, C; Luckey, P D; Ma, T; Nahn, S; Paus, C; Ralph, D; Roland, C; Roland, G; Rudolph, M; Stephans, G S F; Stöckli, F; Sumorok, K; Sung, K; Wenger, E A; Wolf, R; Xie, S; Yang, M; Yilmaz, Y; Yoon, A S; Zanetti, M; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dudero, P R; Franzoni, G; Haupt, J; Klapoetke, K; Kubota, Y; Mans, J; Pastika, N; Rekovic, V; Rusack, R; Sasseville, M; Singovsky, A; Tambe, N; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Summers, D; Bloom, K; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Godshalk, A; Iashvili, I; Jain, S; Kharchilava, A; Kumar, A; Shipkowski, S P; Smith, K; Zennamo, J; Alverson, G; Barberis, E; Baumgartel, D; Boeriu, O; Chasco, M; Reucroft, S; Swain, J; Trocino, D; Wood, D; Zhang, J; Anastassov, A; Kubik, A; Odell, N; Ofierzynski, R A; Pollack, B; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Brinkerhoff, A; Hildreth, M; Jessop, C; Karmgard, D J; Kolb, J; Kolberg, T; Lannon, K; Luo, W; Lynch, S; Marinelli, N; Morse, D M; Pearson, T; Ruchti, R; Slaunwhite, J; Valls, N; Wayne, M; Ziegler, J; Bylsma, B; Durkin, L S; Gu, J; Hill, C; Killewald, P; Kotov, K; Ling, T Y; Rodenburg, M; Williams, G; Adam, N; Berry, E; Elmer, P; Gerbaudo, D; Halyo, V; Hebda, P; Hunt, A; Jones, J; Laird, E; Pegna, D Lopes; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Quan, X; Saka, H; Stickland, D; Tully, C; Werner, J S; Zuranski, A; Acosta, J G; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Vargas, J E Ramirez; Zatserklyaniy, A; Alagoz, E; Barnes, V E; Bolla, G; Borrello, L; Bortoletto, D; De Mattia, M; Everett, A; Garfinkel, A F; Gutay, L; Hu, Z; Jones, M; Koybasi, O; Kress, M; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Shipsey, I; Silvers, D; Svyatkovskiy, A; Yoo, H D; Zablocki, J; Zheng, Y; Jindal, P; Parashar, N; Boulahouache, C; Ecklund, K M; Geurts, F J M; Padley, B P; Redjimi, R; Roberts, J; Zabel, J; Betchart, B; Bodek, A; Chung, Y S; Covarelli, R; de Barbaro, P; Demina, R; Eshaq, Y; Flacher, H; Garcia-Bellido, A; Goldenzweig, P; Gotra, Y; Han, J; Harel, A; Miner, D C; Orbaker, D; Petrillo, G; Sakumoto, W; Vishnevskiy, D; Zielinski, M; Bhatti, A; Ciesielski, R; Demortier, L; Goulianos, K; Lungu, G; Malik, S; Mesropian, C; Yan, M; Atramentov, O; Barker, A; Duggan, D; Gershtein, Y; Gray, R; Halkiadakis, E; Hidas, D; Hits, D; Lath, A; Panwalkar, S; Patel, R; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Eusebi, R; Flanagan, W; Gilmore, J; Gurrola, A; Kamon, T; Khotilovich, V; Montalvo, R; Osipenkov, I; Pakhotin, Y; Pivarski, J; Safonov, A; Sengupta, S; Tatarinov, A; Toback, D; Weinberger, M; Akchurin, N; Bardak, C; Damgov, J; Jeong, C; Kovitanggoon, K; Lee, S W; Libeiro, T; Mane, P; Roh, Y; Sill, A; Volobouev, I; Wigmans, R; Yazgan, E; Appelt, E; Brownson, E; Engh, D; Florez, C; Gabella, W; Issah, M; Johns, W; Kurt, P; Maguire, C; Melo, A; Sheldon, P; Snook, B; Tuo, S; Velkovska, J; Arenton, M W; Balazs, M; Boutle, S; Cox, B; Francis, B; Hirosky, R; Ledovskoy, A; Lin, C; Neu, C; Yohay, R; Gollapinni, S; Harr, R; Karchin, P E; Lamichhane, P; Mattson, M; Milstène, C; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Dasu, S; Efron, J; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Herndon, M; Hervé, A; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Mohapatra, A; Palmonari, F; Reeder, D; Ross, I; Savin, A; Smith, W H; Swanson, J; Weinberg, M

    2011-11-11

    A study of events with missing transverse energy and an energetic jet is performed using pp collision data at a center-of-mass energy of 7 TeV. The data were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 36 pb(-1). An excess of these events over standard model contributions is a signature of new physics such as large extra dimensions and unparticles. The number of observed events is in good agreement with the prediction of the standard model, and significant extension of the current limits on parameters of new physics benchmark models is achieved.

  19. Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at √{ s} = 7 TeV

    NASA Astrophysics Data System (ADS)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Krammer, M.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Teischinger, F.; Wagner, P.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, S.; Cerny, K.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Maes, T.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Charaf, O.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Vanelderen, L.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Silva Do Amaral, S. M.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Karadzhinova, A.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, S.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, S.; Zhu, B.; Zou, W.; Avila, C.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Dzelalija, M.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Khalil, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Azzolini, V.; Eerola, P.; Fedi, G.; Voutilainen, M.; Czellar, S.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Korpela, A.; Tuuva, T.; Sillou, D.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Karim, M.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Baty, C.; Beauceron, S.; Beaupere, N.; Bedjidian, M.; Bondu, O.; Boudoul, G.; Boumediene, D.; Brun, H.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Falkiewicz, A.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Le Grand, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sordini, V.; Tosi, S.; Tschudi, Y.; Verdier, P.; Viret, S.; Rurua, L.; Anagnostou, G.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.

    2012-09-01

    A search is presented for physics beyond the standard model (BSM) in events with a Z boson, jets, and missing transverse energy (ETmiss). This signature is motivated by BSM physics scenarios, including supersymmetry. The study is performed using a sample of proton-proton collision data collected at √{ s} = 7 TeV with the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.98 fb-1. The contributions from the dominant standard model backgrounds are estimated from data using two complementary strategies, the jet-Z balance technique and a method based on modeling ETmiss with data control samples. In the absence of evidence for BSM physics, we set limits on the non-standard-model contributions to event yields in the signal regions and interpret the results in the context of simplified model spectra. Additional information is provided to facilitate tests of other BSM physics models.

  20. Search for new physics in events with photons, jets, and missing transverse energy in pp collisions at sqrt{s}=7 TeV

    NASA Astrophysics Data System (ADS)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.; Klein, K.

    2013-03-01

    A search for physics beyond the standard model involving events with one or more photons, jets, and missing transverse energy has been performed by the CMS experiment. The data sample corresponds to an integrated luminosity of 4.93 fb-1 of proton-proton collisions at sqrt{s}=7 TeV, produced at the Large Hadron Collider. No excess of events with large missing transverse energy is observed beyond expectations from standard model processes, and upper limits on the signal production cross sections for new physics processes are set at the 95% confidence level. The results of this search are interpreted in the context of three models of new physics: a general model of gauge-mediated supersymmetry breaking, Simplified Models, and a theory involving universal extra dimensions. In the absence of evidence for new physics, exclusion regions are derived in the parameter spaces of the respective models.[Figure not available: see fulltext.

  1. Atoms and Molecules. Physical Science in Action[TM]. Schlessinger Science Library. [Videotape].

    ERIC Educational Resources Information Center

    2000

    There are more than 20 million known substances in the universe, and they are all made of the same basic ingredients--atoms and molecules. In this fun and engaging program, kids will learn about the three main subatomic particles--protons, neutrons and electrons--as well as the forces that keep atoms and molecules together. They'll discover how…

  2. Atomic physics with hard X-rays from high brilliance synchrotron light sources

    SciTech Connect

    Southworth, S.; Gemmell, D.

    1996-08-01

    A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

  3. Physical Construction of the Chemical Atom: Is It Convenient to Go All the Way Back?

    ERIC Educational Resources Information Center

    Izquierdo-Aymerich, Merce; Aduriz-Bravo, Agustin

    2009-01-01

    In this paper we present an analysis of chemistry texts (mainly textbooks) published during the first half of the 20th century. We show the evolution of the explanations therein in terms of atoms and of atomic structure, when scientists were interpreting phenomena as evidence of the discontinuous, corpuscular structure of matter. In this process…

  4. Emulating solid-state physics with a hybrid system of ultracold ions and atoms.

    PubMed

    Bissbort, U; Cocks, D; Negretti, A; Idziaszek, Z; Calarco, T; Schmidt-Kaler, F; Hofstetter, W; Gerritsma, R

    2013-08-23

    We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of high fidelity operations and detection offered by trapped ion systems with ultracold atomic systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to phonons of the ion lattice, thereby emulating a solid-state system. Starting from the microscopic many-body Hamiltonian, we derive the low energy Hamiltonian, including the atomic band structure, and give an expression for the atom-phonon coupling. We discuss possible experimental implementations such as a Peierls-like transition into a period-doubled dimerized state.

  5. Atomic-Scale Investigation of Latent Fission Tracks in Fluorapatite: Physical Characteristics and Annealing Behavior.

    NASA Astrophysics Data System (ADS)

    Paul, Tracy Anne

    1993-01-01

    A JEOL JEM-2000FX analytical transmission electron microscope, equipped with a cold stage and anticontamination device, has been used to study the physical characteristics and annealing behavior of artificially induced fission tracks in fluorapatite. Near the atomic level, unetched fission tracks are not continuous, but are comprised of segments of extended damage that are separated by gaps of undamaged microstructure. From dark-field transmission electron microscopy (TEM) images, it appears that the crystalline damage around tracks, although intensive, is not extensive. As such, the defect density may be represented by a Gaussian-type distribution function. The disordered nature of the track core and defect distribution geometry supports the Ion-Explosion Theory that has been proposed for track formation. TEM analysis reveals that track width is crystallographically controlled. Parallel to the c-axis, tracks display widths of 5 to 13 nm and hexagonal faceting on the (0001) plane. Tracks perpendicular to the c-axis display widths of 3 to 9 nm and prismatic faceting on the (1000) plane. The track cross-section facets mimic etch-pit morphologies and provide a relative measure of the crystal's surface free energy. A consequence of differential bond strengths and elastic properties in the fluorapatite structure, track-width anisotropy resolves etching- and annealing-rate anisotropy that has been reported for fission tracks in fluorapatite. TEM observation of the behavior of fission tracks in response to electron beam exposure (i.e., radiolytic annealing), and temperature increase (i.e., thermal annealing), yields a physical and a kinetic description of the annealing process. Annealing commences with bulging at the track's tapered ends, followed by detachment of a single sphere. This process is replicated until a critical track radius is encountered at which the track geometry approaches an ideal right cylinder. A sinusoidal boundary develops at the track

  6. A guided-ion beam study of the hydrogen atom transfer reaction of state-selected N + 2 with H2 at collision energies ranging from subthermal to 2 eV (c.m.)

    NASA Astrophysics Data System (ADS)

    Knott, W. J.; Proch, D.; Kompa, K. L.; Rose-Petruck, Ch.

    1995-01-01

    This article presents detailed internal and kinetic energy dependent cross sections and reaction rates for the hydrogen atom transfer processes N+2(X 2Σ+g, v+=0-4, J+=2)+H2→N2H++H, which were obtained under single-collision conditions in a guided-ion beam/scattering gas experiment. Preparation of ions in specific states relied on single-color excitation within a resonantly enhanced (2+1) multiphoton ionization scheme. The translational energy of the ions, Elab, was varied from 0.1 eV to approximately 30 eV. A small activation barrier impedes the reaction. Vibronic state preparation of the nitrogen ion is influential on the nature of the energy surface—N+2+H2 or H+2+N2—along which the H atom transfer proceeds. Calculations of model potential energy surfaces suggest that the reaction pathway must involve several exoergic and endoergic channels which open successively as the collision energy increases. A purely collision determined cross section—as would be evidenced by the E-1/2 dependence formulated in the Langevin-Gioumousis-Stevenson model—is observed only within a narrow window of kinetic energies.

  7. Differential collision cross-sections for atomic oxygen: Analysis of space flight instruments for solar terrestrial physics

    NASA Technical Reports Server (NTRS)

    Torr, Douglas G.

    1991-01-01

    A summary of the status of the Cross-section Facility at MSFC is presented. A facility was designed, fabricated, assembled, tested, and operated for measurement of differential scattering cross sections important to understand the induced environment for a vehicle (e.g., Space Station) in low earth orbit. A user's manual for the facility is also presented. The performance of the facility was evaluated and found to be satisfactory in all the essential areas. Differential scattering cross sections were measured and results for the scattering measurements are included. Input to the development of the Ultraviolet Imager Optical System is also discussed. Design, fabrication, and evaluation of UV filters using a four-layer aluminum base are reported.

  8. A Learning Pathway in High-School Level Quantum Atomic Physics.

    ERIC Educational Resources Information Center

    Petri, Juergen; Niedderer, Hans

    1998-01-01

    Describes one student's learning pathway as a sequence of several metastable conceptions of the atom starting from a planetary model. Displays the final cognitive element as an association of three parallel conceptions. Contains 26 references. (DDR)

  9. Nonlocal thermodynamic equilibrium self-consistent average-atom model for plasma physics.

    PubMed

    Faussurier, G; Blancard, C; Berthier, E

    2001-02-01

    A time-dependent collisional-radiative average-atom model is presented to study statistical properties of highly charged ion plasmas in off-equilibrium conditions. The time evolution of electron populations and the electron covariance matrix is obtained as approximate solutions of a master equation. Atomic structure is described either with a screened-hydrogenic model including l splitting, or by calculating one-electron states in a self-consistent average-atom potential. Collisional and radiative excitation/deexcitation and ionization/recombination rates, as well as autoionization and dielectronic recombination rates, are formulated within the average-configuration framework. Local thermodynamic equilibrium is obtained as a specific steady-state solution. The influence of atomic structure and the role of autoionization and dielectronic recombination processes are studied by calculating steady-state average ionization and ionization variance of hot plasmas with or without radiation field.

  10. Theoretical studies of molecular collisions

    NASA Technical Reports Server (NTRS)

    Kouri, Donald J.

    1991-01-01

    The following subject areas are covered: (1) total integral reactive cross sections and vibrationally resolved reaction probabilities for F + H2 = HF + H; (2) a theoretical study of inelastic O + N2 collisions; (3) body frame close coupling wave packet approach to gas phase atom-rigit rotor inelastic collisions; (4) wave packet study of gas phase atom-rigit motor scattering; (5) the application of optical potentials for reactive scattering; (6) time dependent, three dimensional body frame quantal wave packet treatment of the H + H2 exchange reaction; (7) a time dependent wave packet approach to atom-diatom reactive collision probabilities; (8) time dependent wave packet for the complete determination of s-matrix elements for reactive molecular collisions in three dimensions; (9) a comparison of three time dependent wave packet methods for calculating electron-atom elastic scattering cross sections; and (10) a numerically exact full wave packet approach to molecule-surface scattering.

  11. FROM THE HISTORY OF PHYSICS: L D Landau in the Soviet Atomic Project: a documentary study

    NASA Astrophysics Data System (ADS)

    Kiselev, G. V.

    2008-09-01

    The article presents information about the participation of Academician L D Landau in the Soviet Atomic Project and is based on a study of archive documents of the First Main Directorate. Their analysis points to L D Landau's important contribution to the development of the theory of heterogeneous nuclear reactors and to the computational justification of the first designs of atomic and hydrogen bombs. Many of the quoted documents have never been published before.

  12. Search for new physics in events with same-sign dileptons and b jets in pp collisions at sqrt{s}=8 TeV

    NASA Astrophysics Data System (ADS)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rabady, D.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Gonzalez, J. Suarez; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Suarez, R. Gonzalez; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Rios, A. A. Ocampo; Ryckbosch, D.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Garcia, J. M. Vizan; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Martins, M. Correa; Martins, T.; Pol, M. E.; Souza, M. H. G.; Júnior, W. L. Aldá; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; De Souza, S. Fonseca; Malbouisson, H.; Malek, M.; Figueiredo, D. Matos; Mundim, L.; Nogima, H.; Da Silva, W. L. Prado; Santoro, A.; Jorge, L. Soares; Sznajder, A.; Pereira, A. Vilela; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Montoya, C. A. Carrillo; Gomez, J. P.; Moreno, B. Gomez; Oliveros, A. F. Osorio; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Mekterovic, D.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Kamel, A. Ellithi; Mahmoud, M. A.; Mahrous, A.; Radi, A.; Kadastik, M.; Müntel, M.; Murumaa, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; de Monchenault, G. Hamel; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Florent, A.; de Cassagnac, R. Granier; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Brochet, S.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Calpas, B.; Edelhoff, M.; Feld, L.; Heracleous, N.

    2013-03-01

    A search for new physics is performed using events with isolated same-sign leptons and at least two bottom-quark jets in the final state. Results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 8 TeV with the CMS detector and corresponding to an integrated luminosity of 10.5 fb-1. No excess above the standard model background is observed. Upper limits are set on the number of events from non-standard-model sources and are used to constrain a number of new physics models. Information on acceptance and efficiencies is also provided so that the results can be used to confront an even broader class of new physics models.[Figure not available: see fulltext.

  13. Orientation and alignment of alkali p-states excited in low-energy collisions of alkali ions with noble gas atoms

    NASA Astrophysics Data System (ADS)

    Menner, B.; Ohlendorf, G.; Patorra, F.; Kempter, V.

    1990-12-01

    The orientation and alignment of Li(2 p) excited in 1 2.5 keV Li+ collisions with He and Ar, and of Na(3 p) excited in 2.5 keV Na+ collisions with He and Ne have been studied by the polarized photon-scattered particle coincidence technique. The covered range of scattering angles is between 1 and 18 degrees. The data are presented in terms of the alignment angle γ and the transferred angular momentum L ⊥. A qualitative analysis of the data is attempted on the basis of diabatic molecular orbital diagrams for the studied collisions systems.

  14. Collision Dynamics With Stretched Atoms

    DTIC Science & Technology

    2007-11-02

    Nt 1 + 3(e0 + 3/2)/e 2(e0 + 3/2) 3 (17) The factor ZZR\\ originates from the reaction volume R\\ while the additional R\\ originates from the (1-2...operator: R{n,<f>) c + (1 — c)n\\ (1 - c)nin2 - sn3 sn2 + (1 - cn,\

  15. Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at [Formula: see text].

    PubMed

    Chatrchyan, S; Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Aguilo, E; Bergauer, T; Dragicevic, M; Erö, J; Fabjan, C; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hörmann, N; Hrubec, J; Jeitler, M; Kiesenhofer, W; Knünz, V; Krammer, M; Krätschmer, I; Liko, D; Mikulec, I; Pernicka, M; Rahbaran, B; Rohringer, C; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Waltenberger, W; Walzel, G; Widl, E; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Bansal, M; Bansal, S; Cornelis, T; De Wolf, E A; Janssen, X; Luyckx, S; Mucibello, L; Ochesanu, S; Roland, B; Rougny, R; Selvaggi, M; Staykova, Z; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Blekman, F; Blyweert, S; D'Hondt, J; Gonzalez Suarez, R; Kalogeropoulos, A; Maes, M; Olbrechts, A; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Clerbaux, B; De Lentdecker, G; Dero, V; Gay, A P R; Hreus, T; Léonard, A; Marage, P E; Mohammadi, A; Reis, T; Thomas, L; Vander Marcken, G; Vander Velde, C; Vanlaer, P; Wang, J; Adler, V; Beernaert, K; Cimmino, A; Costantini, S; Garcia, G; Grunewald, M; Klein, B; Lellouch, J; Marinov, A; Mccartin, J; Ocampo Rios, A A; Ryckbosch, D; Strobbe, N; Thyssen, F; Tytgat, M; Verwilligen, P; Walsh, S; Yazgan, E; Zaganidis, N; Basegmez, S; Bruno, G; Castello, R; Ceard, L; Delaere, C; du Pree, T; Favart, D; Forthomme, L; Giammanco, A; Hollar, J; Lemaitre, V; Liao, J; Militaru, O; Nuttens, C; Pagano, D; Pin, A; Piotrzkowski, K; Schul, N; Vizan Garcia, J M; Beliy, N; Caebergs, T; Daubie, E; Hammad, G H; Alves, G A; Correa Martins Junior, M; De Jesus Damiao, D; Martins, T; Pol, M E; Souza, M H G; Aldá Júnior, W L; Carvalho, W; Custódio, A; Da Costa, E M; De Oliveira Martins, C; Fonseca De Souza, S; Matos Figueiredo, D; Mundim, L; Nogima, H; Oguri, V; Prado Da Silva, W L; Santoro, A; Soares Jorge, L; Sznajder, A; Anjos, T S; Bernardes, C A; Dias, F A; Fernandez Perez Tomei, T R; Gregores, E M; Lagana, C; Marinho, F; Mercadante, P G; Novaes, S F; Padula, Sandra S; Genchev, V; Iaydjiev, P; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Tcholakov, V; Trayanov, R; Vutova, M; Dimitrov, A; Hadjiiska, R; Kozhuharov, V; Litov, L; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Jiang, C H; Liang, D; Liang, S; Meng, X; Tao, J; Wang, J; Wang, X; Wang, Z; Xiao, H; Xu, M; Zang, J; Zhang, Z; Asawatangtrakuldee, C; Ban, Y; Guo, Y; Li, W; Liu, S; Mao, Y; Qian, S J; Teng, H; Wang, D; Zhang, L; Zou, W; Avila, C; Gomez, J P; Gomez Moreno, B; Osorio Oliveros, A F; Sanabria, J C; Godinovic, N; Lelas, D; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Kovac, M; Brigljevic, V; Duric, S; Kadija, K; Luetic, J; Morovic, S; Attikis, A; Galanti, M; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Finger, M; Finger, M; Assran, Y; Elgammal, S; Ellithi Kamel, A; Mahmoud, M A; Radi, A; Kadastik, M; Müntel, M; Raidal, M; Rebane, L; Tiko, A; Eerola, P; Fedi, G; Voutilainen, M; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Peltola, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Ungaro, D; Wendland, L; Banzuzi, K; Karjalainen, A; Korpela, A; Tuuva, T; Besancon, M; Choudhury, S; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Millischer, L; Nayak, A; Rander, J; Rosowsky, A; Shreyber, I; Titov, M; Baffioni, S; Beaudette, F; Benhabib, L; Bianchini, L; Bluj, M; Broutin, C; Busson, P; Charlot, C; Daci, N; Dahms, T; Dobrzynski, L; Granier de Cassagnac, R; Haguenauer, M; Miné, P; Mironov, C; Naranjo, I N; Nguyen, M; Ochando, C; Paganini, P; Sabes, D; Salerno, R; Sirois, Y; Veelken, C; Zabi, A; Agram, J-L; Andrea, J; Bloch, D; Bodin, D; Brom, J-M; Cardaci, M; Chabert, E C; Collard, C; Conte, E; Drouhin, F; Ferro, C; Fontaine, J-C; Gelé, D; Goerlach, U; Juillot, P; Le Bihan, A-C; Van Hove, P; Fassi, F; Mercier, D; Beauceron, S; Beaupere, N; Bondu, O; Boudoul, G; Chasserat, J; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Fay, J; Gascon, S; Gouzevitch, M; Ille, B; Kurca, T; Lethuillier, M; Mirabito, L; Perries, S; Sgandurra, L; Sordini, V; Tschudi, Y; Verdier, P; Viret, S; Tsamalaidze, Z; Anagnostou, G; Autermann, C; Beranek, S; Edelhoff, M; Feld, L; Heracleous, N; Hindrichs, O; Jussen, R; Klein, K; Merz, J; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Sprenger, D; Weber, H; Wittmer, B; Zhukov, V; Ata, M; Caudron, J; Dietz-Laursonn, E; Duchardt, D; Erdmann, M; Fischer, R; Güth, A; Hebbeker, T; Heidemann, C; Hoepfner, K; Klingebiel, D; Kreuzer, P; Merschmeyer, M; Meyer, A; Olschewski, M; Papacz, P; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Steggemann, J; Teyssier, D; Weber, M; Bontenackels, M; Cherepanov, V; Erdogan, Y; Flügge, G; Geenen, H; Geisler, M; Haj Ahmad, W; Hoehle, F; Kargoll, B; Kress, T; Kuessel, Y; Lingemann, J; Nowack, A; Perchalla, L; Pooth, O; Sauerland, P; Stahl, A; Aldaya Martin, M; Behr, J; Behrenhoff, W; Behrens, U; Bergholz, M; Bethani, A; Borras, K; Burgmeier, A; Cakir, A; Calligaris, L; Campbell, A; Castro, E; Costanza, F; Dammann, D; Diez Pardos, C; Eckerlin, G; Eckstein, D; Flucke, G; Geiser, A; Glushkov, I; Gunnellini, P; Habib, S; Hauk, J; Hellwig, G; Jung, H; Kasemann, M; Katsas, P; Kleinwort, C; Kluge, H; Knutsson, A; Krämer, M; Krücker, D; Kuznetsova, E; Lange, W; Lohmann, W; Lutz, B; Mankel, R; Marfin, I; Marienfeld, M; Melzer-Pellmann, I-A; Meyer, A B; Mnich, J; Mussgiller, A; Naumann-Emme, S; Novgorodova, O; Olzem, J; Perrey, H; Petrukhin, A; Pitzl, D; Raspereza, A; Ribeiro Cipriano, P M; Riedl, C; Ron, E; Rosin, M; Salfeld-Nebgen, J; Schmidt, R; Schoerner-Sadenius, T; Sen, N; Spiridonov, A; Stein, M; Walsh, R; Wissing, C; Blobel, V; Draeger, J; Enderle, H; Erfle, J; Gebbert, U; Görner, M; Hermanns, T; Höing, R S; Kaschube, K; Kaussen, G; Kirschenmann, H; Klanner, R; Lange, J; Mura, B; Nowak, F; Peiffer, T; Pietsch, N; Rathjens, D; Sander, C; Schettler, H; Schleper, P; Schlieckau, E; Schmidt, A; Schröder, M; Schum, T; Seidel, M; Sola, V; Stadie, H; Steinbrück, G; Thomsen, J; Vanelderen, L; Barth, C; Berger, J; Böser, C; Chwalek, T; De Boer, W; Descroix, A; Dierlamm, A; Feindt, M; Guthoff, M; Hackstein, C; Hartmann, F; Hauth, T; Heinrich, M; Held, H; Hoffmann, K H; Honc, S; Katkov, I; Komaragiri, J R; Lobelle Pardo, P; Martschei, D; Mueller, S; Müller, Th; Niegel, M; Nürnberg, A; Oberst, O; Oehler, A; Ott, J; Quast, G; Rabbertz, K; Ratnikov, F; Ratnikova, N; Röcker, S; Scheurer, A; Schilling, F-P; Schott, G; Simonis, H J; Stober, F M; Troendle, D; Ulrich, R; Wagner-Kuhr, J; Wayand, S; Weiler, T; Zeise, M; Daskalakis, G; Geralis, T; Kesisoglou, S; Kyriakis, A; Loukas, D; Manolakos, I; Markou, A; Markou, C; Mavrommatis, C; Ntomari, E; Gouskos, L; Mertzimekis, T J; Panagiotou, A; Saoulidou, N; Evangelou, I; Foudas, C; Kokkas, P; Manthos, N; Papadopoulos, I; Patras, V; Bencze, G; Hajdu, C; Hidas, P; Horvath, D; Sikler, F; Veszpremi, V; Vesztergombi, G; Beni, N; Czellar, S; Molnar, J; Palinkas, J; Szillasi, Z; Karancsi, J; Raics, P; Trocsanyi, Z L; Ujvari, B; Beri, S B; Bhatnagar, V; Dhingra, N; Gupta, R; Kaur, M; Mehta, M Z; Nishu, N; Saini, L K; Sharma, A; Singh, J B; Kumar, Ashok; Kumar, Arun; Ahuja, S; Bhardwaj, A; Choudhary, B C; Malhotra, S; Naimuddin, M; Ranjan, K; Sharma, V; Shivpuri, R K; Banerjee, S; Bhattacharya, S; Dutta, S; Gomber, B; Jain, Sa; Jain, Sh; Khurana, R; Sarkar, S; Sharan, M; Abdulsalam, A; Choudhury, R K; Dutta, D; Kailas, S; Kumar, V; Mehta, P; Mohanty, A K; Pant, L M; Shukla, P; Aziz, T; Ganguly, S; Guchait, M; Maity, M; Majumder, G; Mazumdar, K; Mohanty, G B; Parida, B; Sudhakar, K; Wickramage, N; Banerjee, S; Dugad, S; Arfaei, H; Bakhshiansohi, H; Etesami, S M; Fahim, A; Hashemi, M; Hesari, H; Jafari, A; Khakzad, M; Mohammadi Najafabadi, M; Paktinat Mehdiabadi, S; Safarzadeh, B; Zeinali, M; Abbrescia, M; Barbone, L; Calabria, C; Chhibra, S S; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Fiore, L; Iaselli, G; Lusito, L; Maggi, G; Maggi, M; Marangelli, B; My, S; Nuzzo, S; Pacifico, N; Pompili, A; Pugliese, G; Selvaggi, G; Silvestris, L; Singh, G; Venditti, R; Zito, G; Abbiendi, G; Benvenuti, A C; Bonacorsi, D; Braibant-Giacomelli, S; Brigliadori, L; Capiluppi, P; Castro, A; Cavallo, F R; Cuffiani, M; Dallavalle, G M; Fabbri, F; Fanfani, A; Fasanella, D; Giacomelli, P; Grandi, C; Guiducci, L; Marcellini, S; Masetti, G; Meneghelli, M; Montanari, A; Navarria, F L; Odorici, F; Perrotta, A; Primavera, F; Rossi, A M; Rovelli, T; Siroli, G P; Travaglini, R; Albergo, S; Cappello, G; Chiorboli, M; Costa, S; Potenza, R; Tricomi, A; Tuve, C; Barbagli, G; Ciulli, V; Civinini, C; D'Alessandro, R; Focardi, E; Frosali, S; Gallo, E; Gonzi, S; Meschini, M; Paoletti, S; Sguazzoni, G; Tropiano, A; Benussi, L; Bianco, S; Colafranceschi, S; Fabbri, F; Piccolo, D; Fabbricatore, P; Musenich, R; Tosi, S; Benaglia, A; De Guio, F; Di Matteo, L; Fiorendi, S; Gennai, S; Ghezzi, A; Malvezzi, S; Manzoni, R A; Martelli, A; Massironi, A; Menasce, D; Moroni, L; Paganoni, M; Pedrini, D; Ragazzi, S; Redaelli, N; Sala, S; Tabarelli de Fatis, T; Buontempo, S; Carrillo Montoya, C A; Cavallo, N; De Cosa, A; Dogangun, O; Fabozzi, F; Iorio, A O M; Lista, L; Meola, S; Merola, M; Paolucci, P; Azzi, P; Bacchetta, N; Bisello, D; Branca, A; Carlin, R; Checchia, P; Dorigo, T; Gasparini, F; Gasparini, U; Gozzelino, A; Kanishchev, K; Lacaprara, S; Lazzizzera, I; Margoni, M; Meneguzzo, A T; Pazzini, J; Pozzobon, N; Ronchese, P; Simonetto, F; Torassa, E; Tosi, M; Vanini, S; Zotto, P; Zucchetta, A; Zumerle, G; Gabusi, M; Ratti, S P; Riccardi, C; Torre, P; Vitulo, P; Biasini, M; Bilei, G M; Fanò, L; Lariccia, P; Lucaroni, A; Mantovani, G; Menichelli, M; Nappi, A; Romeo, F; Saha, A; Santocchia, A; Spiezia, A; Taroni, S; Azzurri, P; Bagliesi, G; Bernardini, J; Boccali, T; Broccolo, G; Castaldi, R; D'Agnolo, R T; Dell'Orso, R; Fiori, F; Foà, L; Giassi, A; Kraan, A; Ligabue, F; Lomtadze, T; Martini, L; Messineo, A; Palla, F; Rizzi, A; Serban, A T; Spagnolo, P; Squillacioti, P; Tenchini, R; Tonelli, G; Venturi, A; Verdini, P G; Barone, L; Cavallari, F; Del Re, D; Diemoz, M; Fanelli, C; Grassi, M; Longo, E; Meridiani, P; Micheli, F; Nourbakhsh, S; Organtini, G; Paramatti, R; Rahatlou, S; Sigamani, M; Soffi, L; Amapane, N; Arcidiacono, R; Argiro, S; Arneodo, M; Biino, C; Cartiglia, N; Costa, M; Dellacasa, G; Demaria, N; Mariotti, C; Maselli, S; Migliore, E; Monaco, V; Musich, M; Obertino, M M; Pastrone, N; Pelliccioni, M; Potenza, A; Romero, A; Sacchi, R; Solano, A; Staiano, A; Vilela Pereira, A; Belforte, S; Candelise, V; Casarsa, M; Cossutti, F; Della Ricca, G; Gobbo, B; Marone, M; Montanino, D; Penzo, A; Schizzi, A; Heo, S G; Kim, T Y; Nam, S K; Chang, S; Kim, D H; Kim, G N; Kong, D J; Park, H; Ro, S R; Son, D C; Son, T; Kim, J Y; Kim, Zero J; Song, S; Choi, S; Gyun, D; Hong, B; Jo, M; Kim, H; Kim, T J; Lee, K S; Moon, D H; Park, S K; Choi, M; Kim, J H; Park, C; Park, I C; Park, S; Ryu, G; Cho, Y; Choi, Y; Choi, Y K; Goh, J; Kim, M S; Kwon, E; Lee, B; Lee, J; Lee, S; Seo, H; Yu, I; Bilinskas, M J; Grigelionis, I; Janulis, M; Juodagalvis, A; Castilla-Valdez, H; De La Cruz-Burelo, E; Heredia-de La Cruz, I; Lopez-Fernandez, R; Magaña Villalba, R; Martínez-Ortega, J; Sanchez-Hernandez, A; Villasenor-Cendejas, L M; Carrillo Moreno, S; Vazquez Valencia, F; Salazar Ibarguen, H A; Casimiro Linares, E; Morelos Pineda, A; Reyes-Santos, M A; Krofcheck, D; Bell, A J; Butler, P H; Doesburg, R; Reucroft, S; Silverwood, H; Ahmad, M; Ansari, M H; Asghar, M I; Hoorani, H R; Khalid, S; Khan, W A; Khurshid, T; Qazi, S; Shah, M A; Shoaib, M; Bialkowska, H; Boimska, B; Frueboes, T; Gokieli, R; Górski, M; Kazana, M; Nawrocki, K; Romanowska-Rybinska, K; Szleper, M; Wrochna, G; Zalewski, P; Brona, G; Bunkowski, K; Cwiok, M; Dominik, W; Doroba, K; Kalinowski, A; Konecki, M; Krolikowski, J; Almeida, N; Bargassa, P; David, A; Faccioli, P; Ferreira Parracho, P G; Gallinaro, M; Seixas, J; Varela, J; Vischia, P; Bunin, P; Gavrilenko, M; Golutvin, I; Gorbunov, I; Karjavin, V; Konoplyanikov, V; Kozlov, G; Lanev, A; Malakhov, A; Moisenz, P; Palichik, V; Perelygin, V; Savina, M; Shmatov, S; Smirnov, V; Volodko, A; Zarubin, A; Evstyukhin, S; Golovtsov, V; Ivanov, Y; Kim, V; Levchenko, P; Murzin, V; Oreshkin, V; Smirnov, I; Sulimov, V; Uvarov, L; Vavilov, S; Vorobyev, A; Vorobyev, An; Andreev, Yu; Dermenev, A; Gninenko, S; Golubev, N; Kirsanov, M; Krasnikov, N; Matveev, V; Pashenkov, A; Tlisov, D; Toropin, A; Epshteyn, V; Erofeeva, M; Gavrilov, V; Kossov, M; Lychkovskaya, N; Popov, V; Safronov, G; Semenov, S; Stolin, V; Vlasov, E; Zhokin, A; Andreev, V; Azarkin, M; Dremin, I; Kirakosyan, M; Leonidov, A; Mesyats, G; Rusakov, S V; Vinogradov, A; Belyaev, A; Boos, E; Bunichev, V; Dubinin, M; Dudko, L; Ershov, A; Gribushin, A; Klyukhin, V; Kodolova, O; Lokhtin, I; Markina, A; Obraztsov, S; Perfilov, M; Petrushanko, S; Popov, A; Sarycheva, L; Savrin, V; Azhgirey, I; Bayshev, I; Bitioukov, S; Grishin, V; Kachanov, V; Konstantinov, D; Krychkine, V; Petrov, V; Ryutin, R; Sobol, A; Tourtchanovitch, L; Troshin, S; Tyurin, N; Uzunian, A; Volkov, A; Adzic, P; Djordjevic, M; Ekmedzic, M; Krpic, D; Milosevic, J; Aguilar-Benitez, M; Alcaraz Maestre, J; Arce, P; Battilana, C; Calvo, E; Cerrada, M; Chamizo Llatas, M; Colino, N; De La Cruz, B; Delgado Peris, A; Domínguez Vázquez, D; Fernandez Bedoya, C; Fernández Ramos, J P; Ferrando, A; Flix, J; Fouz, M C; Garcia-Abia, P; Gonzalez Lopez, O; Goy Lopez, S; Hernandez, J M; Josa, M I; Merino, G; Puerta Pelayo, J; Quintario Olmeda, A; Redondo, I; Romero, L; Santaolalla, J; Soares, M S; Willmott, C; Albajar, C; Codispoti, G; de Trocóniz, J F; Brun, H; Cuevas, J; Fernandez Menendez, J; Folgueras, S; Gonzalez Caballero, I; Lloret Iglesias, L; Piedra Gomez, J; Brochero Cifuentes, J A; Cabrillo, I J; Calderon, A; Chuang, S H; Duarte Campderros, J; Felcini, M; Fernandez, M; Gomez, G; Gonzalez Sanchez, J; Graziano, A; Jorda, C; Lopez Virto, A; Marco, J; Marco, R; Martinez Rivero, C; Matorras, F; Munoz Sanchez, F J; Rodrigo, T; Rodríguez-Marrero, A Y; Ruiz-Jimeno, A; Scodellaro, L; Vila, I; Vilar Cortabitarte, R; Abbaneo, D; Auffray, E; Auzinger, G; Bachtis, M; Baillon, P; Ball, A H; Barney, D; Benitez, J F; Bernet, C; Bianchi, G; Bloch, P; Bocci, A; Bonato, A; Botta, C; Breuker, H; Camporesi, T; Cerminara, G; Christiansen, T; Coarasa Perez, J A; D'Enterria, D; Dabrowski, A; De Roeck, A; Di Guida, S; Dobson, M; Dupont-Sagorin, N; Elliott-Peisert, A; Frisch, B; Funk, W; Georgiou, G; Giffels, M; Gigi, D; Gill, K; Giordano, D; Giunta, M; Glege, F; Gomez-Reino Garrido, R; Govoni, P; Gowdy, S; Guida, R; Hansen, M; Harris, P; Hartl, C; Harvey, J; Hegner, B; Hinzmann, A; Innocente, V; Janot, P; Kaadze, K; Karavakis, E; Kousouris, K; Lecoq, P; Lee, Y-J; Lenzi, P; Lourenço, C; Magini, N; Mäki, T; Malberti, M; Malgeri, L; Mannelli, M; Masetti, L; Meijers, F; Mersi, S; Meschi, E; Moser, R; Mozer, M U; Mulders, M; Musella, P; Nesvold, E; Orimoto, T; Orsini, L; Palencia Cortezon, E; Perez, E; Perrozzi, L; Petrilli, A; Pfeiffer, A; Pierini, M; Pimiä, M; Piparo, D; Polese, G; Quertenmont, L; Racz, A; Reece, W; Rodrigues Antunes, J; Rolandi, G; Rovelli, C; Rovere, M; Sakulin, H; Santanastasio, F; Schäfer, C; Schwick, C; Segoni, I; Sekmen, S; Sharma, A; Siegrist, P; Silva, P; Simon, M; Sphicas, P; Spiga, D; Tsirou, A; Veres, G I; Vlimant, J R; Wöhri, H K; Worm, S D; Zeuner, W D; Bertl, W; Deiters, K; Erdmann, W; Gabathuler, K; Horisberger, R; Ingram, Q; Kaestli, H C; König, S; Kotlinski, D; Langenegger, U; Meier, F; Renker, D; Rohe, T; Sibille, J; Bäni, L; Bortignon, P; Buchmann, M A; Casal, B; Chanon, N; Deisher, A; Dissertori, G; Dittmar, M; Donegà, M; Dünser, M; Eugster, J; Freudenreich, K; Grab, C; Hits, D; Lecomte, P; Lustermann, W; Marini, A C; Martinez Ruiz Del Arbol, P; Mohr, N; Moortgat, F; Nägeli, C; Nef, P; Nessi-Tedaldi, F; Pandolfi, F; Pape, L; Pauss, F; Peruzzi, M; Ronga, F J; Rossini, M; Sala, L; Sanchez, A K; Starodumov, A; Stieger, B; Takahashi, M; Tauscher, L; Thea, A; Theofilatos, K; Treille, D; Urscheler, C; Wallny, R; Weber, H A; Wehrli, L; Amsler, C; Chiochia, V; De Visscher, S; Favaro, C; Ivova Rikova, M; Millan Mejias, B; Otiougova, P; Robmann, P; Snoek, H; Tupputi, S; Verzetti, M; Chang, Y H; Chen, K H; Kuo, C M; Li, S W; Lin, W; Liu, Z K; Lu, Y J; Mekterovic, D; Singh, A P; Volpe, R; Yu, S S; Bartalini, P; Chang, P; Chang, Y H; Chang, Y W; Chao, Y; Chen, K F; Dietz, C; Grundler, U; Hou, W-S; Hsiung, Y; Kao, K Y; Lei, Y J; Lu, R-S; Majumder, D; Petrakou, E; Shi, X; Shiu, J G; Tzeng, Y M; Wan, X; Wang, M; Asavapibhop, B; Srimanobhas, N; Adiguzel, A; Bakirci, M N; Cerci, S; Dozen, C; Dumanoglu, I; Eskut, E; Girgis, S; Gokbulut, G; Gurpinar, E; Hos, I; Kangal, E E; Karaman, T; Karapinar, G; Kayis Topaksu, A; Onengut, G; Ozdemir, K; Ozturk, S; Polatoz, A; Sogut, K; Sunar Cerci, D; Tali, B; Topakli, H; Vergili, L N; Vergili, M; Akin, I V; Aliev, T; Bilin, B; Bilmis, S; Deniz, M; Gamsizkan, H; Guler, A M; Ocalan, K; Ozpineci, A; Serin, M; Sever, R; Surat, U E; Yalvac, M; Yildirim, E; Zeyrek, M; Gülmez, E; Isildak, B; Kaya, M; Kaya, O; Ozkorucuklu, S; Sonmez, N; Cankocak, K; Levchuk, L; Bostock, F; Brooke, J J; Clement, E; Cussans, D; Flacher, H; Frazier, R; Goldstein, J; Grimes, M; Heath, G P; Heath, H F; Kreczko, L; Metson, S; Newbold, D M; Nirunpong, K; Poll, A; Senkin, S; Smith, V J; Williams, T; Basso, L; Bell, K W; Belyaev, A; Brew, C; Brown, R M; Cockerill, D J A; Coughlan, J A; Harder, K; Harper, S; Jackson, J; Kennedy, B W; Olaiya, E; Petyt, D; Radburn-Smith, B C; Shepherd-Themistocleous, C H; Tomalin, I R; Womersley, W J; Bainbridge, R; Ball, G; Beuselinck, R; Buchmuller, O; Colling, D; Cripps, N; Cutajar, M; Dauncey, P; Davies, G; Della Negra, M; Ferguson, W; Fulcher, J; Futyan, D; Gilbert, A; Guneratne Bryer, A; Hall, G; Hatherell, Z; Hays, J; Iles, G; Jarvis, M; Karapostoli, G; Lyons, L; Magnan, A-M; Marrouche, J; Mathias, B; Nandi, R; Nash, J; Nikitenko, A; Papageorgiou, A; Pela, J; Pesaresi, M; Petridis, K; Pioppi, M; Raymond, D M; Rogerson, S; Rose, A; Ryan, M J; Seez, C; Sharp, P; Sparrow, A; Stoye, M; Tapper, A; Vazquez Acosta, M; Virdee, T; Wakefield, S; Wardle, N; Whyntie, T; Chadwick, M; Cole, J E; Hobson, P R; Khan, A; Kyberd, P; Leggat, D; Leslie, D; Martin, W; Reid, I D; Symonds, P; Teodorescu, L; Turner, M; Hatakeyama, K; Liu, H; Scarborough, T; Charaf, O; Henderson, C; Rumerio, P; Avetisyan, A; Bose, T; Fantasia, C; Heister, A; Lawson, P; Lazic, D; Rohlf, J; Sperka, D; St John, J; Sulak, L; Alimena, J; Bhattacharya, S; Cutts, D; Ferapontov, A; Heintz, U; Jabeen, S; Kukartsev, G; Laird, E; Landsberg, G; Luk, M; Narain, M; Nguyen, D; Segala, M; Sinthuprasith, T; Speer, T; Tsang, K V; Breedon, R; Breto, G; Calderon De La Barca Sanchez, M; Chauhan, S; Chertok, M; Conway, J; Conway, R; Cox, P T; Dolen, J; Erbacher, R; Gardner, M; Houtz, R; Ko, W; Kopecky, A; Lander, R; Miceli, T; Pellett, D; Ricci-Tam, F; Rutherford, B; Searle, M; Smith, J; Squires, M; Tripathi, M; Vasquez Sierra, R; Andreev, V; Cline, D; Cousins, R; Duris, J; Erhan, S; Everaerts, P; Farrell, C; Hauser, J; Ignatenko, M; Jarvis, C; Plager, C; Rakness, G; Schlein, P; Traczyk, P; Valuev, V; Weber, M; Babb, J; Clare, R; Dinardo, M E; Ellison, J; Gary, J W; Giordano, F; Hanson, G; Jeng, G Y; Liu, H; Long, O R; Luthra, A; Nguyen, H; Paramesvaran, S; Sturdy, J; Sumowidagdo, S; Wilken, R; Wimpenny, S; Andrews, W; Branson, J G; Cerati, G B; Cittolin, S; Evans, D; Golf, F; Holzner, A; Kelley, R; Lebourgeois, M; Letts, J; Macneill, I; Mangano, B; Padhi, S; Palmer, C; Petrucciani, G; Pieri, M; Sani, M; Sharma, V; Simon, S; Sudano, E; Tadel, M; Tu, Y; Vartak, A; Wasserbaech, S; Würthwein, F; Yagil, A; Yoo, J; Barge, D; Bellan, R; Campagnari, C; D'Alfonso, M; Danielson, T; Flowers, K; Geffert, P; Incandela, J; Justus, C; Kalavase, P; Koay, S A; Kovalskyi, D; Krutelyov, V; Lowette, S; Mccoll, N; Pavlunin, V; Rebassoo, F; Ribnik, J; Richman, J; Rossin, R; Stuart, D; To, W; West, C; Apresyan, A; Bornheim, A; Chen, Y; Di Marco, E; Duarte, J; Gataullin, M; Ma, Y; Mott, A; Newman, H B; Rogan, C; Spiropulu, M; Timciuc, V; Veverka, J; Wilkinson, R; Xie, S; Yang, Y; Zhu, R Y; Akgun, B; Azzolini, V; Calamba, A; Carroll, R; Ferguson, T; Iiyama, Y; Jang, D W; Liu, Y F; Paulini, M; Vogel, H; Vorobiev, I; Cumalat, J P; Drell, B R; Edelmaier, C J; Ford, W T; Gaz, A; Heyburn, B; Luiggi Lopez, E; Smith, J G; Stenson, K; Ulmer, K A; Wagner, S R; Alexander, J; Chatterjee, A; Eggert, N; Gibbons, L K; Heltsley, B; Khukhunaishvili, A; Kreis, B; Mirman, N; Nicolas Kaufman, G; Patterson, J R; Ryd, A; Salvati, E; Sun, W; Teo, W D; Thom, J; Thompson, J; Tucker, J; Vaughan, J; Weng, Y; Winstrom, L; Wittich, P; Winn, D; Abdullin, S; Albrow, M; Anderson, J; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Bloch, I; Burkett, K; Butler, J N; Chetluru, V; Cheung, H W K; Chlebana, F; Elvira, V D; Fisk, I; Freeman, J; Gao, Y; Green, D; Gutsche, O; Hanlon, J; Harris, R M; Hirschauer, J; Hooberman, B; Jindariani, S; Johnson, M; Joshi, U; Kilminster, B; Klima, B; Kunori, S; Kwan, S; Leonidopoulos, C; Linacre, J; Lincoln, D; Lipton, R; Lykken, J; Maeshima, K; Marraffino, J M; Maruyama, S; Mason, D; McBride, P; Mishra, K; Mrenna, S; Musienko, Y; Newman-Holmes, C; O'Dell, V; Prok