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1

Experiments in atomic and applied physics using synchrotron radiation  

SciTech Connect

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.

Jones, K.W.

1987-01-01

2

Versatile single-chip event sequencer for atomic physics experiments  

NASA Astrophysics Data System (ADS)

A very inexpensive dsPIC microcontroller with internal 32-bit counters is used to produce a flexible timing signal generator with up to 16 TTL-compatible digital outputs, with a time resolution and accuracy of 50 ns. This time resolution is easily sufficient for event sequencing in typical experiments involving cold atoms or laser spectroscopy. This single-chip device is capable of triggered operation and can also function as a sweeping delay generator. With one additional chip it can also concurrently produce accurately timed analog ramps, and another one-chip addition allows real-time control from an external computer. Compared to an FPGA-based digital pattern generator, this design is slower but simpler and more flexible, and it can be reprogrammed using ordinary `C' code without special knowledge. I will also describe the use of the same microcontroller with additional hardware to implement a digital lock-in amplifier and PID controller for laser locking, including a simple graphics-based control unit. This work is supported in part by the NSF.

Eyler, Edward

2010-03-01

3

Atomic physics experiments with photon and ion beams  

SciTech Connect

The experiments investigated the feasibility of: (1) producing multiply-charged argon ions (up to 7+) at very low energies in quantities sufficient for experimental purposes, (2) using ion trap techniques for further study of the ions and repetitive photoionization to achieve higher charge states, and (3) using a VUV spectrometer to study fluorescent radiation emitted from the ions.

Jones, K.W.; Johnson, B.M.; Meron, M.

1987-03-01

4

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

SciTech Connect

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.

LeBrun, T. [Argonne National Lab., IL (United States). Physics Div.

1996-12-31

5

Several atomic-physics issues connected with the use of neutral beams in fusion experiments  

SciTech Connect

Energetic neutral beams are used for heating and diagnostics in present magnetic fusion experiments. They are also being considered for use in future large experiments. Atomic physics issues are important for both the production of the neutral beams and the interaction of the beams and the plasma. Interest in neutral beams based on negative hydrogen ions is growing, largely based on advances in producing high current ion sources. An extension of the negative ion approach has been the suggestion to use negative ions of Z > 1 elements, such as carbon and oxygen, to form high power neutral beams for plasma heating.

Post, D.E.; Grisham, L.R.; Fonck, R.J.

1982-08-01

6

Enhancing the Undergraduate Experience: Atomic and Nuclear Physics Experiments at AN Accelerator Facility  

NASA Astrophysics Data System (ADS)

In this paper we will discuss experiments performed using an accelerated ion beam incident on selected targets. Some of these were: 1) Measuring Rutherford scattering and/or non-Rutherford nature of scattering as a function of scattering angle, energy of the ion beam and atomic number 2) Verifying theoretical prediction of the kinematical scattering factor by measuring the scattered ion energy 3) Particle Induced X-ray emission (PIXE) and/or Rutherford scattering to determine the elemental thickness and test the theoretical prediction for the x-ray production cross sections. 4) Determination of the mass absorption coefficient of lead using gamma ray spectroscopy 5) Nuclear reaction studies (proton on lithium fluoride) using sodium iodide detector 6) Applying X-ray fluorescence to determine elemental composition.

Mehta, Rahul; Addison, Stephen R.; Duggan, Jerome L.

2009-03-01

7

A distributed, graphical user interface based, computer control system for atomic physics experiments  

NASA Astrophysics Data System (ADS)

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.

Keshet, Aviv; Ketterle, Wolfgang

2013-01-01

8

Chaos in Atomic Physics  

NASA Astrophysics Data System (ADS)

Preface; 1. Introduction; 2. Chaos: tools and concepts; 3. Chaos in classical mechanics; 4. Chaos in quantum mechanics; 5. The kicked rotor: paradigm of chaos; 6. Microwave-driven surface state electrons; 7. The hydrogen atom in a strong magnetic field; 8. The kicked hydrogen atom; 9. Chaotic scattering with CsI molecules; 10. The helium atom; 11. Chaos in atomic physics: state of the art and research directions; References; Index.

Blümel, R.; Reinhardt, W. P.

2005-08-01

9

Atomic physics of lasers  

SciTech Connect

This book illustrates the basic concepts using lasers. It describes physical processes rather than comprehensive mathematical formulations. Topics considered include an elementary review of the structure of atoms and molecules, interaction of electromagnetic radiation with atoms, light amplification, solid and liquid lasers, and gas lasers.

Eastham, D.A.

1986-01-01

10

Basic Atomic Physics.  

National Technical Information Service (NTIS)

Construction is beginning on an atom interferometer (a device which interferes atom waves). Fabricated metal transmissions gratings will be used as optical elements for the matter waves. Atom interferometers should be useful in studies of atomic propertie...

D. E. Pritchard

1988-01-01

11

Efimov physics in atom-dimer scattering of Li atoms  

Microsoft Academic Search

Li atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective-field theory to calculate the atom-dimer relaxation rate at zero temperature.

H.-W. Hammer; Daekyoung Kang; Lucas Platter

2010-01-01

12

Contemporary Aspects of Atomic Physics  

ERIC Educational Resources Information Center

|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)|

Knott, R. G. A.

1972-01-01

13

Contemporary Aspects of Atomic Physics  

ERIC Educational Resources Information Center

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)

Knott, R. G. A.

1972-01-01

14

Theoretical atomic collision physics  

SciTech Connect

The current focus of the research is low-energy (collision v<atom (including Rydberg atom) collisions with atoms, molecules and positive and negative ions: (1) We are interested in the dependence of various differential and total cross sections on the angular momentum of the initial excited state and on the alignment of the initial electron charge distribution (for non-spherical initially excited states). (2) We wish to understand how characteristics of the classical trajectories (in CTMC calculations), e.g. multiple encounters, quasi-periodicity, chaos, relate to characteristics of the probability (scattering) amplitudes obtained from semiclassical (quantum mechanical) treatments. (3) In particular, in order to investigate a range of interaction regimes,'' we have proposed to study low-Rydberg-atom collisions with: ions and polar molecules (long range interaction); non-polar molecules and atoms (short-range interaction); as well as electron-attaching atoms/molecules (transient electron capture possible). (4) We plan to look for observable signatures of possibly novel intracollisional interference effects and quasi-vibrational resonance effects that may occur in low-Rydberg collisions.

Lane, N.F.

1992-03-09

15

The Tokamak Physics Experiment  

SciTech Connect

The mission of the Tokamak Physics Experiment (TPX) [Nevins {ital et} {ital al}., {ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion}, Wuerzburg (International Atomic Energy Agency, Vienna, 1992), Vol. 3, p. 279] is to develop the scientific basis for an economically competitive and continuously operating tokamak fusion power source. This complements the primary mission of the International Thermonuclear Experimental Reactor (ITER) [ITER Document Ser. No. 18 (International Atomic Energy Agency, Vienna, 1991)], the demonstration of ignition and long-pulse burn, and the integration of nuclear technologies. The TPX program is focused on making the demonstration power plant that follows ITER as compact and attractive as possible, and on permitting ITER to achieve its ultimate goal of steady-state operation. This mission of TPX requires the development of steady-state regimes with high beta, good confinement, and a high fraction of a self-driven bootstrap current. These regimes must be compatible with plasma stability, strong heat-flux dispersion in the divertor region, and effective particle control.

Davidson, R.C.; Goldston, R.J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Neilson, G.H. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Thomassen, K.I. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

1995-06-01

16

Atomic-Nuclear Coupling Experiments  

SciTech Connect

Atomic-nuclear coupling experiments are described, with an emphasis on recent experiments aimed at demonstrating the NEET mechanism in atomic nuclei. Upper limits for x-ray induced decay of the Hf-178 31-y isomer reported by Ahmad and his colleagues are presented, and these upper limits are contrasted with the positive reports of Collins and coworkers.

Becker, J. A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

2006-03-13

17

Atomic-Nuclear Coupling Experiments  

NASA Astrophysics Data System (ADS)

Atomic-nuclear coupling experiments are described, with an emphasis on recent experiments aimed at demonstrating the NEET mechanism in atomic nuclei. Upper limits for x-ray induced decay of the Hf-178 31-y isomer reported by Ahmad and his colleagues are presented, and these upper limits are contrasted with the positive reports of Collins and coworkers.

Becker, J. A.

2006-03-01

18

Experiments With Trapped Neutral Atoms.  

National Technical Information Service (NTIS)

Major steps were taken to explore superfluidity in Fermi clouds. This created close links with condensed matter and many body physics. During the funding period, major advances were done towards atom interferometry with Bose-Einstein condensates. The goal...

W. Ketterle

2010-01-01

19

On the influence of atomic physics mechanisms on edge plasma turbulence in the TJ-I and Princeton Beta Experiment-Modified tokamaks  

SciTech Connect

The role of neutrals as a driving force of plasma turbulence was investigated in the TJ-I tokamak [Phys. Fluids B {bold 5}, 4051 (1993)]. No influence of the local neutral source strength on fluctuation levels was found, neither in the plasma bulk side nor in the scrape-off layer side of the velocity shear layer location. Helium puffing was used to study the influence of impurity radiation on turbulence in the Princeton Beta Experiment-Modified (PBX-M) [{ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research} 1988 (International Atomic Physics Agency, Nice, 1989), Vol. 1, p. 97]. Evidence of fluctuation levels modified increasing He-impurity radiation was obtained. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Pedrosa, M.A.; Garcia-Cortes, I.; Branas, B.; Balbin, R.; Hidalgo, C. [Asociacion EURATOM/CIEMAT, 28040-Madrid (Spain); Schmitz, L.; Tynan, G. [University of California at Los Angeles, Los Angeles, California 90024 (United States); Post-Zwicker, A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 3783, The PBX-M Team (United States)]|[Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

1995-07-01

20

Experiments in cold atom optics towards precision atom interferometry  

NASA Astrophysics Data System (ADS)

Atom optics has been a highly active field of research with many scientific breakthroughs over the past two decades, largely due to successful advances in laser technology, microfabrication techniques, and the development of laser cooling and trapping of neutral atoms. This dissertation details several atom optics experiments with the motivation to develop tools and techniques for precision atom wave interferometry. It provides background information about atom optics and the fundamentals behind laser cooling and trapping, including basic techniques for cold gas thermometry and absorptive detection of atoms. A brief overview of magnetic trapping and guiding in tight wire-based traps is also provided before the experimental details are presented. We developed a novel laser source of 780 nm light using frequency-doubled 1560 nm fiber amplifier. This laser system provided up to a Watt of tunable frequency stabilized light for two Rb laser cooling and trapping experiments. One system generates Bose-Einstein condensates in an optical trap while the second is based on atom chip magnetic traps. The atom chip system, detailed in this thesis, was designed and built to develop the tools necessary for transport and loading large numbers of cold atoms and explore the potential for guided atom interferometry. Techniques and results from this experiment are presented, including an efficient magnetic transport and loading method to deliver cold atom to atom chip traps. We also developed a modeling tool for the magnetic fields formed by coiled wire geometries, as well as planar wire patterns. These models helped us design traps and determine adiabatic transportation of cold atoms between macro-scale traps and micro-traps formed on atom chips. Having achieved near unity transfer efficiency, we demonstrated that this approach promises to be a consistent method for loading large numbers of atoms into micro-traps. Furthermore, we discuss an in situ imaging technique to investigate magnetic field contours of the traps and the dynamics of atoms within those confining potentials. We also controlled the propagation along the atom chip guides by accelerating atoms with longitudinal magnetic gradients, and investigated an atom focusing scheme. While the atom chip wire guides perform a role analogous to optical fibers guiding light waves, "free space" cold atoms offer great opportunity for precision interferometry. We describe a second on-going atom optics experiment that measures gravity gradients using a pair of atom fountain interferometers separated by one meter. We have demonstrated Gravity Gradiometer resolution down to 4x10-9 g/m using a 40 kg test mass. The atomic physics subsystem is described in detail, including the vacuum, cold atom source, optics, magnetic coils and shields, and vibration isolation and compensation. The system is designed to be a compact, robust, transportable instrument, taking strides towards future gravity gradient measurements in the field. In the realm of space applications, there has been interest for micro-gravity science experiments aboard the International Space Station, along with instrument development for gravity mapping of Earth and planetary bodies with satellite-based instruments. Furthermore, there are ground-based applications for gravity imaging of local density distributions, precision measurement of gravity, as well as proposals for redefining the kilogram, detecting gravitational waves and determining the Gravitational constant.

Aveline, David C.

21

Atoms and the basic laws of physics  

Microsoft Academic Search

For decades, from the birth of quantum mechanics to the triumph of quantum electrodynamics, the study of atoms was central to uncovering the laws of physics. Today, remarkably sensitive techniques enable atomic physics to continue probing fundamental interactions. For example precise measurement of atomic parity violation together with major improvement in atomic theory have helped elucidate the nature of the

Norval Fortson

2004-01-01

22

Atomic physics tests of nonlinear quantum mechanics  

NASA Astrophysics Data System (ADS)

Atomic physics experiments which test a nonlinear generalization of quantum mechanics recently formulated by Weinberg are described. The experiments search for a dependence of hyperfine transition frequencies or nuclear spin precession frequencies on the relative populations of the hyperfine or nuclear spin states. The experiments set limits less than 10 ?Hz on the size of the possible nonlinear contributions to these frequencies. In some cases this can be interpreted as a limit of less than ~10-26 on the fraction of binding energy per nucleon that could be due to a nonlinear correction to a nuclear Hamiltonian. The possibility that a nonlinear addition to quantum mechanics violates causality is discussed.

Bollinger, J. J.; Heinzen, D. J.; Itano, Wayne M.; Gilbert, S. L.; Wineland, D. J.

1991-08-01

23

Atomic parity experiment has its moment  

SciTech Connect

A group in Boulder, Colorado, has set a new record for precision in the measurement of an atomic transition that does not conserve parity. The experiment not only places constraints on the Standard Model of electroweak interactions but also provides evidence for the long-predicted nuclear anapole moment. {copyright} {ital 1997 American Institute of Physics}

Goss Levi, B. [American Institute of Physics, American Center for Physics, One Physics Ellipse, College Park, Maryland 20740-3843 (United States)

1997-04-01

24

A Physical Model for Atoms and Nuclei—Part 1  

Microsoft Academic Search

A physical geometrical packing model for the structure of the atom is developed based on the physical toroidal ring model of elementary particles proposed by Bergman.(1) From the physical characteristics of real electrons from experiments by Compton (2,3,4) this work derives, using combinatorial geometry, the number of electrons that will pack into the various physical shells about the nucleus in

Joseph Lucas; Charles W. Lucas

2002-01-01

25

Bringing Atoms into First-Year Physics.  

ERIC Educational Resources Information Center

|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)|

Chabay, Ruth W.; Sherwood, Bruce A.

1999-01-01

26

Atomic, molecular and optical physics at Bethel  

NASA Astrophysics Data System (ADS)

An example of the close connection between research and advanced labs at Bethel University is the recent realization of cold lithium atoms in a magneto-optical trap (MOT). Several aspects of the cooling and trapping research took root in the laboratory components of the Optics and Lasers upper-level courses. These included a wavelength meter with sub-picometer accuracy and precision, stabilized laser diodes and molecular and atomic spectroscopy. Work on the MOT began in 2008 and has involved students (a total of 12, including several post-General Physics sophomores) working during summers, course projects and senior research. Lithium MOTs offer challenges (e.g. low vapor pressure) and advantages in an undergraduate lab with respect to the more common rubidium systems. Lasers for lithium are at 671 nm, a more practical red color that can still take advantage of inexpensive laser diodes and broadband optical coatings. Its relatively simple atomic structure makes lithium amenable for stringent comparisons between theory and experiment. Recent high precision absolute frequency measurements using an atomic beam disagree. Cold-atom spectroscopy of lithium could help resolve questions about the atomic structure of lithium.

Hoyt, Chad; Klemme, Dan

2012-02-01

27

Bose–Einstein condensation in dilute atomic gases: atomic physics meets condensed matter physics  

Microsoft Academic Search

Bose–Einstein condensed atomic gases are a new class of quantum fluids. They are produced by cooling a dilute atomic gas to nanokelvin temperatures using laser and evaporative cooling techniques. The study of these quantum gases has become an interdisciplinary field of atomic and condensed matter physics. Topics of many-body physics can now be studied with the methods of atomic physics.

W. Ketterle

2000-01-01

28

Experiments in Ice Physics.  

ERIC Educational Resources Information Center

|Describes experiments in ice physics that demonstrate the behavior and properties of ice. Show that ice behaves as an ionic conductor in which charge is transferred by the movement of protons, its electrical conductivity is highly temperature-dependent, and its dielectric properties show dramatic variation in the kilohertz range. (Author/GA)|

Martin, P. F.; And Others

1978-01-01

29

Atomic physics in strong fields  

SciTech Connect

This report discusses: Microwave Driven Multiphoton Excitation Dynamics in Rydberg Atoms; Nonadiabatic Geometric Phases of Multiphoton Transitions in Dissipative Systems and Spin-j Systems; and Nonperturbative Treatments of Atomic and Molecular Processes in Intense Laser Fields.

Chu, Shih-I.

1992-04-01

30

Project Physics Tests 5, Models of the Atom.  

ERIC Educational Resources Information Center

|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,…

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

31

Many-Body Atomic Physics  

NASA Astrophysics Data System (ADS)

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.

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

2005-11-01

32

Many-Body Atomic Physics  

NASA Astrophysics Data System (ADS)

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.

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

1998-09-01

33

Efimov physics in atom-dimer scattering of Li6 atoms  

Microsoft Academic Search

Li6 atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective-field theory to calculate the atom-dimer relaxation rate at zero temperature.

H.-W. Hammer; Daekyoung Kang; Lucas Platter

2010-01-01

34

Effective Operators in Atomic Physics  

Microsoft Academic Search

The correlation effects of inter-electronic interactions between atomic configurations can be reproduced by effective orthogonal operators acting within a single configuration of interest. These operators which act on N electrons at a time can be resolved through the use of continuous Lie groups. This thesis details the development of these effective operators for a number of configurations. Complete sets of

Richard Carlson Leavitt

1989-01-01

35

Crucial Experiments in Quantum Physics.  

ERIC Educational Resources Information Center

|The six experiments included in this monography are titled Blackbody Radiation, Collision of Electrons with Atoms, The Photoelectric Effect, Magnetic Properties of Atoms, The Scattering of X-Rays, and Diffraction of Electrons by a Crystal Lattice. The discussion provides historical background by giving description of the original experiments and…

Trigg, George L.

36

Physically Sound Orthogonality Procedures for Atomic Physics Calculations  

Microsoft Academic Search

A physically sensible orthogonality procedure for use in atomic calculations is described. For clarity we focus on the orthogonalization of ejected-election orbitals to bound target orbitals for calculation of single ionization of multielectron atoms. A simple application to electron ionization of helium is given to illustrate the general analytic properties of the procedure and its practicability.

Alvin M. Halpern; Brian K. Thomas

1979-01-01

37

The Physics of Artificial Atoms  

NASA Astrophysics Data System (ADS)

When electrons are confined to a small region of space their charge and energy become quantized. If the confined droplet of electrons is coupled to conducting leads by tunnel junctions, the result is a transistor that turns on and off again every time a single electron is added to it. The analogy between the confined droplet of electrons in such a single-electron transistor (SET) and an atom is quite deep. In fact, over the years we have demonstrated that the Anderson Hamiltonian, designed for an impurity atom in a metal, quantitatively describes the behavior of SETs. Thus the SET is a system in which we can control the terms in a non-trivial many-body Hamiltonian, by varying electrode voltages, and observe the consequences. I will review the history of the emergence of this picture and discuss some outstanding problems. This work, spanning more than a decade, has involved faculty, students and postdocs at MIT and colleagues at IBM and the Weizmann Institute. Our research is supported by the US Army Research Office under contract DAAG 55-98-1-10138, by the National Science Foundation under grant DMR-9732579 and by the MRSEC program of the National Science Foundation under grant DMR-9808941.

Kastner, Marc A.

2000-03-01

38

Atomic Physics, Science (Experimental): 5318.42.  

ERIC Educational Resources Information Center

|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…

Petit, Ralph E.

39

The ALADDIN atomic physics database system  

NASA Astrophysics Data System (ADS)

ALADDIN is an atomic physics database system which has been developed in order to provide a broadly-based standard medium for the exchange and management of atomic data. ALADDIN consists of a data format definition together with supporting software for both interactive searches as well as for access to the data by plasma modeling and other codes. 8AB The ALADDIN system is designed to offer maximum flexibility in the choice of data representations and labeling schemes, so as to support a wide range of atomic physics data types and allow natural evolution and modification of the database as needs change. Associated dictionary files are included in the ALADDIN system for data documentation. The importance of supporting the widest possible user community was also central to be ALADDIN design, leading to the use of straightforward text files with concatentated data entries for the file structure, and the adoption of strict FORTRAN 77 code for the supporting software. This will allow ready access to the ALADDIN system on the widest range of scientific computers, and easy interfacing with FORTRAN modeling codes, user developed atomic physics codes and database, etc. This supporting software consists of the ALADDIN interactive searching and data display code, together with the ALPACK subroutine package which provides ALADDIN datafile searching and data retrieval capabilities to user's codes. ALADDIN has been adopted as the standard international atomic physics data exchange format for magnetic confinement fusion applications by the International Atomic Energy Agency (IAEA). Entry of critically evaluated atomic data sets into ALADDIN format is to be coordinated by the IAEA atomic and Molecular Data Unit, which will also coordinate long-term development and distribution of updated software and documentation. The increasingly widespread adoption of the ALADDIN data format can be expected to greatly facilitate access to atomic data both within and outside of this original fusion application area.

Hulse, Russell A.

1990-05-01

40

Atomic physics at high brilliance synchrotron sources: Proceedings  

NASA Astrophysics Data System (ADS)

This report contains papers on the following topics: present status of Spring-8 and the atomic physics undulator beamline; recent photoabsorption measurements in the rare gases and alkalis in the 3 to 15 keV proton energy region; atomic and molecular physics at LURE; experiments on atoms, ions and small molecules using the new generation of synchrotron radiation sources; soft x-ray fluorescence spectroscopy using tunable synchrotron radiation; soft x-ray fluorescence spectroscopy excited by synchrotron radiation: Inelastic and resonant scattering near threshold; outer-shell photoionization of ions; overview of the APS BESSRC beamline development; the advanced light source: Research opportunities in atomic and molecular physics; Photoionization of the Ba(+) ion by 4d shell excitation; decay dynamics of inner-shell excited atoms and molecules; absorption of atomic Ca, Cr, Mn and Cu; High-resolution photoelectron studies of resonant molecular photoionization; radiative and radiationless resonant Raman scattering by synchrotron radiation; Auger spectrometry of atoms and molecules; some thoughts of future experiments with the new generation of storage rings; Electron spectroscopy studies of argon K-shell excitation and vacancy cascades; ionization of atoms by high energy photons; ion coincidence spectroscopy on rare gas atoms and small molecules after photoexcitation at energies of several keV; an EBIS for use with synchrotron radiation photoionization of multiply charged ions and PHOBIS; gamma-2e coincidence measurements - the wave of the future in inner-shell electron spectroscopy; recoil momentum spectroscopy in ion-atom and photon-atom collisions; a study of Compton ionization of helium; future perspectives of photoionization studies at high photon energies; and status report on the advanced photon source. These papers have been cataloged separately elsewhere.

Berry, G.; Cowan, P.; Gemmell, D.

1994-08-01

41

Atomic physics at high brilliance synchrotron sources: Proceedings  

SciTech Connect

This report contains papers on the following topics: present status of SPring-8 and the atomic physics undulator beamline; recent photoabsorption measurements in the rare gases and alkalis in the 3 to 15 keV proton energy region; atomic and molecular physics at LURE; experiments on atoms, ions and small molecules using the new generation of synchrotron radiation sources; soft x-ray fluorescence spectroscopy using tunable synchrotron radiation; soft x-ray fluorescence spectroscopy excited by synchrotron radiation: Inelastic and resonant scattering near threshold; outer-shell photoionization of ions; overview of the APS BESSRC beamline development; the advanced light source: Research opportunities in atomic and molecular physics; Photoionization of the Ba{sup +} ion by 4d shell excitation; decay dynamics of inner-shell excited atoms and molecules; absorption of atomic Ca, Cr, Mn and Cu; High-resolution photoelectron studies of resonant molecular photoionization; radiative and radiationless resonant raman scattering by synchrotron radiation; auger spectrometry of atoms and molecules; some thoughts of future experiments with the new generation of storage rings; Electron spectroscopy studies of argon K-shell excitation and vacancy cascades; ionization of atoms by high energy photons; ion coincidence spectroscopy on rare gas atoms and small molecules after photoexcitation at energies of several keV; an EBIS for use with synchrotron radiation photoionization of multiply charged ions and PHOBIS; gamma-2e coincidence measurements the wave of the future in inner-shell electron spectroscopy; recoil momentum spectroscopy in ion-atom and photon-atom collisions; a study of compton ionization of helium; future perspectives of photoionization studies at high photon energies; and status report on the advanced photon source. These papers have been cataloged separately elsewhere.

Berry, G.; Cowan, P.; Gemmell, D.

1994-08-01

42

Discrepancies in experiments with cold hydrogen atoms  

SciTech Connect

Recent experiments with atomic clocks and hydrogen gas samples have shown discrepancies between theory and experiment. There are serious disagreements with respect to four different parameters: two different frequency shift parameters and a line broadening cross section relating to the H maser, and a longitudinal relaxation rate observed in a hydrogen gas sample. We study the changes in the short-range singlet and triplet potentials that would be needed to eliminate the above discrepancies. We find that no such changes can remove all four discrepancies simultaneously. In addition, we investigate a possible role of spin-dipole interactions, which have been neglected in previous calculations. {copyright} {ital 1997} {ital The American Physical Society}

Kokkelmans, S.J.; Verhaar, B.J. [Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (The Netherlands)

1997-11-01

43

Proton Structure and Atomic Physics  

SciTech Connect

We discuss a precise determination of the polarizability and other proton structure dependent contributions to the hydrogen hyperfine splitting, based heavily on the most recent published data on proton spin dependent structure functions from the EG1 experiment at the Jefferson Laboratory. As a result, the total calculated hyperfine splitting now has a standard deviation slightly under 1 part-per-million, and is about 1 standard deviation away from the measured value.

Carlson, Carl E. [Physics Department, College of William and Mary, Williamsburg, VA 23187-8795 (United States)

2009-07-27

44

Study of atomic physics and population inversions with plasma focus  

SciTech Connect

The plasma focus can be used to generate high temperature and high density plasmas. Neon-like plasmas have previously been studied in Z-pinches and laser produced plasmas as sources for XUV and x-ray lasers. The plasma focus provides a simple and inexpensive source for studying atomic physics of highly ionized atoms. A detailed understanding of atomic physics at high temperatures, densities, and megagauss magnetic fields is necessary for possible x-ray laser designs. Methods that are generally used for obtaining population inversions include collisional ionization of the inner shells of multi-electron atoms and ions, photoexcitation, and electron collisional excitation of ions, collisional combination of ions, and atom-ion resonant charge exchange. We will discuss some possible experiments to help understand the atomic physics under the above condition. Some ideas and calculations will be given to show the feasibility of doing atomic physics relating to x-ray lasers with a plasma focus. 13 refs., 2 figs.

Oona, H.; Hodgdon, M.L.; Rickel, D.G.; Freeman, B.L.

1989-01-01

45

Atomic physics of highly charged ions. Proceedings.  

NASA Astrophysics Data System (ADS)

The present status of scientific work involving highly ionized atoms is reviewed in this proceedings volume, which incorporates the progress made over the last two years. More than 20 invited articles cover the whole area of active research in this field, including applications in plasmas, ion-surface interactions, precision spectroscopy, electron-ion recombination and ionization, ion-atom collisions, storage-ring physics, and ion sources. Nearly 100 contributed papers deal with the latest theoretical and experimental achievements, presenting the reader with the current state of the art in highly charged ion physics.

Salzborn, E.; Müller, A.; Mokler, P. H.

46

Experiments with Trapped Neutral Atoms.  

National Technical Information Service (NTIS)

Our long-term goals are twofold. First, to explore the new properties of gaseous Bose-Einstein condensates and advance our understanding of quantum gases. Second, we want to use Bose condensed gases as new atom sources of unprecedented brightness ('atom l...

W. Ketterle

2000-01-01

47

Using Physical Experiments as Oracles  

NASA Astrophysics Data System (ADS)

In my talk I will consider how a digital computer (a Turing machine for the sake of being definite) could communicate with the physical world. Turing himself gave a mythological name to an external source of information for a computer - an oracle. We shall consider how a physical experiment can be used to function as an oracle for a computer - a physical oracle. Thought experiments can be constructed using various physical theories, and we will examine their properties when used as oracles. The fundamental ideas we have to introduce into oracles for this are the time taken to perform the experiment, and the possibility of error in the answer.

Beggs, Edwin J.

48

The role of atomic physics in testing the Standard Model  

NASA Astrophysics Data System (ADS)

A brief survey is given of studies of parity non-conserving phenomena in atomic physics and of the search for permanent atomic electric dipole moments (edm's). The latter can only occur if there is simultaneous violation of both parity and time-reversal invariance. The role of such experiments in testing the Standard Model is discussed. "P only" experiments are in quantitative agreement with the Standard Model. While the Model predicts edm's well below the present level of sensitivity, and none has yet been observed, the hope is for surprises.

Stacey, D. N.

1995-01-01

49

Atomic physics with highly charged ions  

NASA Astrophysics Data System (ADS)

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.

Richard, Patrick

1994-08-01

50

The ALADDIN atomic physics database system  

SciTech Connect

ALADDIN is an atomic physics database system which has been developed in order to provide a broadly-based standard medium for the exchange and management of atomic data. ALADDIN consists of a data format definition together with supporting software for both interactive searches as well as for access to the data by plasma modeling and other codes. 8AB The ALADDIN system is designed to offer maximum flexibility in the choice of data representations and labeling schemes, so as to support a wide range of atomic physics data types and allow natural evolution and modification of the database as needs change. Associated dictionary files are included in the ALADDIN system for data documentation. The importance of supporting the widest possible user community was also central to be ALADDIN design, leading to the use of straightforward text files with concatentated data entries for the file structure, and the adoption of strict FORTRAN 77 code for the supporting software. This will allow ready access to the ALADDIN system on the widest range of scientific computers, and easy interfacing with FORTRAN modeling codes, user developed atomic physics codes and database, etc. This supporting software consists of the ALADDIN interactive searching and data display code, together with the ALPACK subroutine package which provides ALADDIN datafile searching and data retrieval capabilities to user's codes.

Hulse, R.A. (Princeton University, Plasma Physics Laboratory, Princeton, New Jersey 08543 (USA))

1990-05-01

51

CAI Physics Experiments  

ERIC Educational Resources Information Center

|Describes a novel instructional method for physics involving the use of a computer assisted instruction system equipped with cathode-ray-tube terminals, light pen, and keyboard input. Discusses exercises with regard to content, mediation, scoring and control. Several examples of exercises are given along with results from student evaluation. (LC)|

Lindsay, Robert E.

1970-01-01

52

ZAPP: Z-pinch atomic physics program  

SciTech Connect

High-density and high-temperature plasmas have been produced in a z-pinch with a hollow gas puff. A number of interesting atomic-physics phenomena occur in these plasmas and some of these phenomena provide important diagnostic information for characterizing the plasmas. We have been interested in collisions of high-energy electrons with highly stripped ions in these plasmas. Such collisions may produce a population inversion which could result in stimulated emission in the x-ray regime.

Reed, K.

1983-01-07

53

Efimov physics in {sup 6}Li atoms  

SciTech Connect

A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold {sup 6}Li atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the three-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at 672+-2 G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the three-body recombination rate at 759+-1 G where the three-spin mixture may be sufficiently stable to allow experimental study of the many-body system.

Braaten, Eric [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, 53115 Bonn (Germany); Hammer, H.-W. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, 53115 Bonn (Germany); Kang, Daekyoung; Platter, Lucas [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)

2010-01-15

54

Efimov physics in Li6 atoms  

NASA Astrophysics Data System (ADS)

A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold Li6 atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O’Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the three-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at 672±2 G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the three-body recombination rate at 759±1 G where the three-spin mixture may be sufficiently stable to allow experimental study of the many-body system.

Braaten, Eric; Hammer, H.-W.; Kang, Daekyoung; Platter, Lucas

2010-01-01

55

Efimov Physics in Li-6 Atoms  

NASA Astrophysics Data System (ADS)

A new narrow 3-atom loss resonance associated with an Efimov trimer crossing the 3-atom threshold has recently been discovered in a many-body system of ultracold Li-6 atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the 3-body recombination rate in this region to determine the complex 3-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the 3-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at (672 +/- 2) G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the 3-body recombination rate at (759 +/- 1) G where the 3-spin mixture may be sufficiently stable to allow experimental study of the many-body system. )

Kang, Daekyoung; Braaten, Eric; Hammer, Hans-W.; Platter, Lucas

2010-02-01

56

Efimov physics in 6Li atoms  

NASA Astrophysics Data System (ADS)

A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold 6Li atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the three-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at 672 ±2 G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the three-body recombination rate at 759 ±1 G where the three-spin mixture may be sufficiently stable to allow experimental study of the many-body system.

Kang, Daekyoung; Braaten, Eric; Hammer, Hans-Werner; Platter, Lucas

2010-03-01

57

Planning a School Physics Experiment.  

ERIC Educational Resources Information Center

|Presents a model for planning the measurement of physical quantities. Provides two examples of optimizing the conditions of indirect measurement for laboratory experiments which involve measurements of acceleration due to gravity and of viscosity by means of Stokes' formula. (ML)|

Blasiak, Wladyslaw

1986-01-01

58

Efimov physics in atom-dimer scattering of {sup 6}Li atoms  

SciTech Connect

{sup 6}Li atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective-field theory to calculate the atom-dimer relaxation rate at zero temperature. Our results describe the four features qualitatively and imply there is a hidden local minimum. In the vicinity of the resonance at 685 G, we perform a finite temperature calculation which improves the agreement of theory and experiment. We conclude that finite temperature effects cannot be neglected in the analysis of the experimental data.

Hammer, H.-W. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195 (United States); Kang, Daekyoung [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195 (United States); Platter, Lucas [Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195 (United States)

2010-08-15

59

Efimov physics in atom-dimer scattering of Li6 atoms  

NASA Astrophysics Data System (ADS)

Li6 atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective-field theory to calculate the atom-dimer relaxation rate at zero temperature. Our results describe the four features qualitatively and imply there is a hidden local minimum. In the vicinity of the resonance at 685 G, we perform a finite temperature calculation which improves the agreement of theory and experiment. We conclude that finite temperature effects cannot be neglected in the analysis of the experimental data.

Hammer, H.-W.; Kang, Daekyoung; Platter, Lucas

2010-08-01

60

Nanoscale Quantum Devices from an Atomic Physics Perspective  

Microsoft Academic Search

Nanometer-scale semiconductor devices are often hailed as ``artificial atoms,'' whose quantum mechanical properties can be tailor-made to fit any desired application. Here I take the artificial atom concept seriously, bringing the methods of theoretical atomic physics to bear on calculations of nanostructure physics. Electron transport through such a device can be modelled as a scattering process, in which the complicated

John L. Bohn

1996-01-01

61

I.I. Rabi Prize in Atomic, Molecular and Optical Physics Talk: Novel Quantum Physics in Few- and Many-body Atomic Systems  

NASA Astrophysics Data System (ADS)

Recent cold atom researches are reaching out far beyond the realm that was conventionally viewed as atomic physics. Many long standing issues in other physics disciplines or in Gedanken-experiments are nowadays common targets of cold atom physicists. Two prominent examples will be discussed in this talk: BEC-BCS crossover and Efimov physics. Here, cold atoms are employed to emulate electrons in superconductors, and nucleons in nuclear reactions, respectively. The ability to emulate exotic or thought systems using cold atoms stems from the precisely determined, simple, and tunable interaction properties of cold atoms. New experimental tools have also been devised toward an ultimate goal: a complete control and a complete characterization of a few- or many-body quantum system. We are tantalizingly close to this major milestone, and will soon open new venues to explore new quantum phenomena that may (or may not!) exist in scientists' dreams.

Chin, Cheng

2011-06-01

62

Rydberg constant and fundamental atomic physics  

SciTech Connect

A detailed report on the current status of measurements of the Rydberg constant is given. Our recently reported value of R/sub infinity/ = 109 737.315 73(3) cm/sup -1/ has been confirmed by three other laboratories within experimental error. An additional check on the iodine cell, the heart of our wavelength and frequency reference, confirms a negligible pressure shift. The possible role of the Rydberg constant in fundamental atomic physics lies in tests of quantum electrodynamics and in improvement of the realization of the meter. We propose that the hydrogen spectrum be used to realize the meter in the optical domain, as an alternative to the current frequency chains. For the realization to be useful, improvement of the current precision of the Rydberg constant by a factor of 2 or more is required.

Zhao, P.; Lichten, W.; Zhou, Z.; Layer, H.P.; Bergquist, J.C.

1989-03-15

63

Atomic physics and non-LTE effects  

NASA Astrophysics Data System (ADS)

Pulsed-power-driven z-pinch plasmas are an intense source of soft X-ray radiation producing, on the Z facility, about 2 MJ of total radiation for a number of tungsten loads and in the case of a multiwire titanium array over 1 MJ total radiation and about 100 kJ from the titanium K-shell. The production and transport of radiation in these non-LTE plasmas are often modeled assuming some variation of Local Thermodynamic Equilibrium (LTE) in conjunction with radiation diffusion. Since these plasmas are neither in LTE or entirely opaque or transparent these models do not properly predict the emitted radiation spectra and yield. Also, application of these models overestimates the radiation cooling to the extent that the evolving hydrodynamic profiles are significantly different from those that would obtain using the appropriate non-LTE model with a more realistic treatment of the radiation transport. In this investigation, we discuss the production and transport of radiation from the viewpoint of the microscopic collisional and radiative processes and then apply it to z-pinch plasmas. Through the use of examples and illustrations, it is shown that for identical initial load conditions, atomic level structure, and rate coefficients, the models predict different results that affect the dynamic evolution and hydrodynamic history of the plasma. As an example, the emission spectrum is generated using a 1-D radiation MHD model self-consistently coupled to a circuit representing the Sandia Z facility. A comparison is then made between several standard models of ionization dynamics for a multiwire titanium array. Finally, we address some of the issues regarding how the dense plasma environment influences isolated atom structure and processes. These include, for example, atomic level shifts, ionization lowering, collision cross sections, and collision widths. Transition from the isolated-atom to the dressed-particle picture can modify the ionization physics and emission spectra to such an extent that it may challenge our precepts on how best to design loads for the next generation machine.

Davis, J.; Clark, R.; Blaha, M.; Giuliani, J. L.

2001-10-01

64

Active experiments in magnetospheric physics.  

NASA Astrophysics Data System (ADS)

Magnetospheric physics has been and continues to be primarily an observational science, aided and guided by theory. However, increasing emphasis is being given to active experiments for the purpose of clarifying specific phenomena in the magnetospheric plasma. The earliest global scale experiments were the production of artificial radiation belts by high altitude nuclear bomb bursts in 1958-62 and the observation of their geophysical effects. Other active experiments involve the injection of ionized clouds of exotic vapors, the decay products of radioactive sources, and beams of artificially accelerated ions and electrons at selected points in the magnetosphere. The effects of such perturbations of the natural situation as well as those of very low frequency radio waves have been observed by sophisticated diagnostic instrumentation. The in situ determination of the ambient electric field point-by-point in the auroral zone is one of the most important and difficult undertakings. This paper reviews the achievements of active experiments and their future promise.

van Allen, J. A.

65

My views on physics and atomic physics, on science and human life  

NASA Astrophysics Data System (ADS)

The modern physics research was started in the 16th century. From that time any knowledge on the natural processes is based on careful, systematic observation, experiment and measurement. The scope of atomic physics is very broad energetically from nano eV to GeV. From these experiments fundamental information can be obtained and the collision mechanism as well as details of atomic and ionic structure can be clarified. Science is a really special field of the human activity and culture. It is developing mainly with the help of the critique of its own results. Science produced in fact miraculous results but even then it is only one of the approaches to Reality in a broad meaning.

Berényi, Dénes

1999-06-01

66

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

SciTech Connect

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.

Jones, K.W.

1985-12-01

67

Atomic physics and non-equilibrium plasmas  

SciTech Connect

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.

Weisheit, J.C.

1986-04-25

68

Center for Atomic, Molecular, and Optical Physics Technical Activities, 1989.  

National Technical Information Service (NTIS)

The report summarizes the research and technical activities of the Center for Atomic, Molecular and Optical Physics (CAMOP) during the Fiscal Year 1989. The activities include work in the areas of fundamental constants, radiation physics, surface science,...

K. B. Gebbie

1989-01-01

69

Atomic physics in strong fields. Progress report  

SciTech Connect

This report discusses: Microwave Driven Multiphoton Excitation Dynamics in Rydberg Atoms; Nonadiabatic Geometric Phases of Multiphoton Transitions in Dissipative Systems and Spin-j Systems; and Nonperturbative Treatments of Atomic and Molecular Processes in Intense Laser Fields.

Chu, Shih-I

1992-04-01

70

Physics of Hard Spheres Experiment -2 (Phase-2).  

National Technical Information Service (NTIS)

The Physics of Hard Spheres Experiment-2 (PH(sup A)SE-2) seeks to answer fundamental questions about how model atoms change their behavior as more and more neighbors are moved into their neighborhood. The PH(sup A)SE-2 experiment will use an enhanced micr...

P. M. Chaikin W. B. Russel M. T. Sullivan A. D. Hollingsworth A. vanBlaaderen W. V. Meyer M. P. Doherty A. H. Resnick

2001-01-01

71

Project Physics Text 5, Models of the Atom.  

ERIC Educational Resources Information Center

|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…

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

72

On the utility and ubiquity of atomic collision physics  

SciTech Connect

This paper is divided into three parts. In the introduction, we discuss the history and makeup of ICPEAC. In the second part, we discuss the extent of applicability of atomic collision physics. In the third part, we chose one subject (dielectronic excitation) to show the interrelationship of various sub-branches of atomic collision physics. 28 refs., 14 figs.

Datz, S.

1989-01-01

73

Atomic Hydrogen Polarimetry for Precision Electroweak Experiments  

NASA Astrophysics Data System (ADS)

In parity-violating electron scattering experiments the measurement of the electron beam polarization using Compton or Møller polarimetry is frequently the dominant experimental systematic uncertainty (e.g. HAPPEx-III, PV-DIS, PREx, and QWeak at Jefferson Lab, and PVA4 at the University of Mainz). Future experiments, in particular the SoLID and MOLLER experiments at Jefferson Lab and the P2 experiment at the University of Mainz, will require electron beam polarimetry with a precision better than 0.5%. Improving Møller polarimetry with polarized iron foil targets to this level is challenging due to heating-induced target depolarization and the Levchuk effect. A new Møller polarimeter with polarized atomic hydrogen at 0.3,trapped inside an internal target in a strong solenoidal magnetic field is being developed at the University of Mainz in collaboration with several US groups. This technique is not affected by the Levchuk effect and will allow for non-invasive, continuous polarization measurements. The depolarizing effect due to the ionization into single electrons and H^- or H2^+ ions will be mitigated through a system of electrodes. I will present the atomic hydrogen polarimeter, and discuss in-beam tests at the University of Mainz.

Deconinck, Wouter

2012-10-01

74

Efimov Physics in Li6 Atoms  

Microsoft Academic Search

A new narrow 3-atom loss resonance associated with an Efimov trimer crossing the 3-atom threshold has recently been discovered in a many-body system of ultracold Li-6 atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the 3-body recombination rate in this region to determine the complex 3-body

Daekyoung Kang; Eric Braaten; Hans-W. Hammer; Lucas Platter

2010-01-01

75

Efimov physics in 6Li atoms  

Microsoft Academic Search

A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold 6Li atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body

Daekyoung Kang; Eric Braaten; Hans-Werner Hammer; Lucas Platter

2010-01-01

76

The physics of spin polarized atomic vapors  

Microsoft Academic Search

Research efforts are focussed on the study of spin polarized atoms, nuclei and electrons during the period covered by this report. Although this work is 6.1 basic research, it has applications to a number of important Air Force problems. For example, the atomic clocks used on the GPS satellite system operate with optically pumped rubidium absorption cells, very similar to

William Happer

1988-01-01

77

Superconducting microwave resonators for physics experiments  

NASA Astrophysics Data System (ADS)

Superconducting resonators at K-band frequencies have been developed for different applications in general physics. Niobium pillbox cavities have been built for the one-atom maser experiment by which the interaction of Rydberg atoms with single microwave photons has been investigated. At 21.5 GHz and 1.3 K, quality factors of up to 10 to the 11th were obtained. Coating of the cavity with Nb3Sn resulted in quality factors of 6 x 108 at 4.2 K and 6 x 10 9th at 2 K. A superconducting Fabry-Perot resonator consisting of two spherically curved niobium mirrors was also investigated. The quality factor of 1.8 x 10 to the 7th measured at 25 GHz and 4.2 K was found to be two orders of magnitude higher than for a corresponding copper resonator. Fabry-Perot resonators can be used for detecting small position changes for one mirror with respect to another caused by gravitational forces. First experiments with copper Fabry-Perot mirrors suspended in a vacuum chamber provided a maximum sensitivity for a gravitational acceleration of one mirror of 4 x 10 to the -11th m/sec sq. These results are promising for a possible fifth force detector based on a superconducting Fabry-Perot resonator.

Klein, N.; Mueller, G.; Piel, H.; Schurr, J.

1989-03-01

78

Atoms, Molecules and Photons: An Introduction to Atomic Molecular and Quantum Physics  

Microsoft Academic Search

This introduction to Atomic and Molecular Physics explains how our present model of atoms and molecules has been developed during the last two centuries by many experimental discoveries and from the theoretical side by the introduction of quantum physics to the adequate description of micro-particles. It illustrates the wave model of particles by many examples and shows the limits of

Wolfgang Demtröder

2006-01-01

79

Divertor bias experiments. General Atomics Project 3466  

SciTech Connect

Electrical biasing of the divertor target plates has recently been implemented on several tokamaks. The results of these experiments to date will be reviewed in this paper. The bias electrode configuration is unique in each experiment. The effects of biasing on the scrape-off layer (SOL) plasma also differ. By comparing results between machines, and using theoretical models, an understanding of the basic physics of biasing begins to emerge. Divertor biasing has been demonstrated to have a strong influence on the particle and energy transport within the SOL. The ability to externally control the SOL plasma with biasing has promising applications to future tokamak reactors.

Staebler, G.M.

1994-06-01

80

Atomic physics of strongly correlated systems  

SciTech Connect

This report presents the progress made in our continuing study of strongly correlated atomic systems within the last year. We have examined the shape of three-body systems in hyperspherical coordinates by studying the evolution of the density functions with the mass ratio of the particles in the system. We have calculated the ejected electron spectra from the autoionizing states formed in double capture processes in collisions of multiply charged ions with atoms. We have investigated the systematics and the propensity rules of radiative and Auger decay rates of high-lying doubly excited states. We have also studied ion-atom collisions for processes which pose great challenges to detailed theories, by looking into processes where the cross sections are small such as the excitation process in He{sup ++} + H collisions, or by looking into fine details such as the orientation parameters in excitation and charge transfer processes.

Lin, Chii-Dong.

1992-01-01

81

Experimental atomic physics in heavy-ion storage rings  

SciTech Connect

This paper outlines the discussion which took place at the ''round table'' on experimental atomic physics in heavy-ion storage rings. Areas of discussion are: electron-ion interactions, ion-ion collisions, precision spectroscopy of highly charged ions, beta decay into bound final states, and atomic binding energies from spectroscopy of conversion elections. 18 refs., 1 tab. (LSP)

Datz, S.; Andersen, L.H.; Briand, J.P.; Liesen, D.

1987-01-01

82

Atomic physics at high brilliance synchrotron sources: Proceedings.  

National Technical Information Service (NTIS)

This report contains papers on the following topics: present status of SPring-8 and the atomic physics undulator beamline; recent photoabsorption measurements in the rare gases and alkalis in the 3 to 15 keV proton energy region; atomic and molecular phys...

G. Berry P. Cowan D. Gemmell

1994-01-01

83

Essen and the National Physical Laboratory's atomic clock  

NASA Astrophysics Data System (ADS)

To commemorate the fiftieth anniversary of the development of the first atomic frequency standard, we present some notes about the work of Louis Essen at the National Physical Laboratory. In addition, we publish below some personal recollections of Essen on his work, which have previously been available only on the Internet (http://www.btinternet.com/~time.lord/TheAtomicClock.htm).

Henderson, Dale

2005-06-01

84

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

ERIC Educational Resources Information Center

|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,…

DETERLINE, WILLIAM A.; KLAUS, DAVID J.

85

Applications of atomic and molecular data to radiation physics  

SciTech Connect

The general purpose of our work is to provide atomic and molecular collision cross sections useful for radiological physics, dosimetry, and other applications. Studies on the systematics of atomic oscillator-strength spectra and a survey of stopping power data are briefly described. (WHK)

Inokuti, M.

1982-01-01

86

Theoretical Atomic Physics code development IV: LINES, A code for computing atomic line spectra  

SciTech Connect

A new computer program, LINES, has been developed for simulating atomic line emission and absorption spectra using the accurate fine structure energy levels and transition strengths calculated by the (CATS) Cowan Atomic Structure code. Population distributions for the ion stages are obtained in LINES by using the Local Thermodynamic Equilibrium (LTE) model. LINES is also useful for displaying the pertinent atomic data generated by CATS. This report describes the use of LINES. Both CATS and LINES are part of the Theoretical Atomic PhysicS (TAPS) code development effort at Los Alamos. 11 refs., 9 figs., 1 tab.

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

1988-12-01

87

Conclusions from recent pionic--atom experiments  

SciTech Connect

The most recent pionic--hydrogen experiment marks the completion of a whole series of measurements, the main goal of which was to provide conclusive data on pion--nucleon interaction at threshold for comparison with calculations from Chiral perturbation theory. The precision achieved for hadronic shift and broadening of 0.2% and 2%, respectively, became possible by comprehensive studies of cascade effects in hydrogen and other light exotic atoms including results from the last years of LEAR operation. In order to obtain optimum conditions for the Bragg crystal spectrometer, the cyclotron trap II has been used to provide a suitable X--ray source. To characterize the bent crystal spectrometer, the cyclotron trap has been modified to operate as an electron--cyclotron resonance source, which produces with high intensity narrow X-ray transitions in the few keV range originating from highly charged ions.

Gotta, D.; Hennebach, M.; Nekipelov, M.; Strauch, Th. [Institut fuer Kernphysik, Forschungszentrum Juelich, D--52425 Juelich (Germany); Amaro, F.; Covita, D. S.; Santos, J. M. F. dos; Veloso, J. F. C. A. [Dept. of Physics, Coimbra University, P--3000 Coimbra (Portugal); Anagnostopoulos, D. F. [Dept. of Material Science and Engineering, University of Ioannina, Ioannina, GR--45110 (Greece); Biri, S. [Institut of Nuclear Research, Hungarian Academy of Sciences, H--4001 Debrecen (Hungary); Gorke, H. [Zentrallabor fuer Elektronik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Gruber, A.; Hirtl, A.; Ishiwatari, T.; Marton, J.; Schmid, Ph.; Zmeskal, J. [Stefan Meyer Institut, Austrian Academy of Sciences, A--1090 Vienna (Austria); Indelicato, P.; Jensen, Th.; Le Bigot, E.-O. [Lab. Kastler Brossel, UPMC-Paris 6, ENS, CNRS, 4 place Jussieu, F--75005 Paris (France)] (and others)

2008-08-08

88

Atomic physics with highly charged ions  

SciTech Connect

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.

Richard, P.

1991-08-01

89

Status of the Los Alamos free atomic tritium beta-decay experiment  

SciTech Connect

An experiment to study the beta-decay of tritium using a gaseous source of free (unbound) atomic tritium is currently underway in the Physics Division at Los Alamos. The use of free atomic tritium along with careful design of the measurement scheme should allow a definitive determination for an electron antineutrino mass approx. 10 eV.

Wilkerson, J.F.; Bowles, T.J.; Browne, J.C.; Burritt, T.H.; Cohen, J.S.; Helffrich, J.A.; Knapp, D.A.; Maley, M.P.; Martin, R.L.; Robertson, R.G.H.

1984-01-01

90

ATOMIC AND MOLECULAR PHYSICS: Lifetime Measurement of Cold Atoms in an Integrating Sphere  

NASA Astrophysics Data System (ADS)

We present an experimental measurement of the lifetime of the cold 87Rb atoms in an integrating sphere. The atoms are cooled by the diffuse light which is generated by the diffuse reflection of laser beams in the integrating sphere. Our result shows that the lifetime is primarily determined by the free fall of the cold 87Rb atoms, and its half-life can reach 40 ms, which is suitable for many experiments, especially for a cold atom clock.

Zhang, Wen-Zhuo; Wang, Xu-Cheng; Cheng, Hua-Dong; Xiao, Ling; Liu, Liang; Wang, Yu-Zhu

2009-08-01

91

LASSP: The Laboratory of Atomic and Solid State Physics  

NSDL National Science Digital Library

The Laboratory of Atomic and Solid State Physics (LASSP) at Cornell University is a center for research in condensed matter physics. Scientists can read about the work of the thirty faculty members in topics such as theoretical condensed matter physics, low temperature physics, experimental liquid physics, and experimental soft-condensed matter and biological physics. With a number of images and animations at the website, students can learn about diffraction patterns of an icosahedral quasicrystal, Coarsening, and Spiral Defect Turbulence. Physicists can find employment opportunities at LASSP as well as information on upcoming seminars, conferences, and meetings.

92

Springer Handbook of Atomic, Molecular, and Optical Physics  

NASA Astrophysics Data System (ADS)

This Springer Handbook of Atomic, Molecular, and Optical Physics comprises a comprehensive reference source that unifies the entire fields of atomic, molecular, and optical (AMO) physics, assembling the principal ideas, techniques and results of the field from atomic spectroscopy to applications in comets. Its 92 chapters are written by over 100 authors, all leaders in their respective disciplines. Carefully edited to ensure uniform coverage and style, with extensive cross references, and acting as a guide to the primary research literature, it is both a source of information and an inspiration for graduate students and other researchers new to the field.

Drake, Gordon W. F.

93

Electrostatic atomization--Experiment, theory and industrial applications  

Microsoft Academic Search

Experimental and theoretical research has been initiated at the Princeton Plasma Physics Laboratory on the electrostatic atomization process in collaboration with Charged Injection Corporation. The goal of this collaboration is to set up a comprehensive research and development program on the electrostatic atomization at the Princeton Plasma Physics Laboratory so that both institutions can benefit from the collaboration. Experimental, theoretical

H. Okuda; Arnold J. Kelly

1996-01-01

94

Positron spectroscopy in atomic and solid state physics  

Microsoft Academic Search

Basic research problems in Atomic Physics with positrons (total cross sections, Ramsauer minima, positronium formation, selective ionization) and some benchmark measurements in Solid State Physics using positron annihilation (He-created nano-voids in Si, Oxygen precipitates in Si, low ? materials) are discussed.

G. P. Karwasz; R. S. Brusa; A. Zecca

2003-01-01

95

Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment  

Microsoft Academic Search

A physical chemistry experiment illustrating photochemistry, cyclic voltammetry, the properties of semiconductors, and surface chemistry is described. The experiment consists of constructing a liquid-junction photochemical cell, determining the cell parameters, then modifying the surface of the electrode to enhance the conversion efficiency of the cell. The students will learn some fundamental physical and chemical principles related to light and electricity

Qinbai Fan; Debra Munro; L. M. Ng

1995-01-01

96

Physical Science Experiments for Scientific Glassblowing Technicians.  

ERIC Educational Resources Information Center

|The twenty experiments in this text have been designed to give the scientific glassblowing technician the opportunity to use scientific glass apparatus in the study of physical science. Primary emphasis of these experiments is on the practical application of the physical science program as a working tool for the scientific glassblowing…

Tillis, Samuel E.; Donaghay, Herbert C.

97

ATOMIC AND MOLECULAR PHYSICS: Dynamic splitting and merging of an atom cloud on an atom chip  

NASA Astrophysics Data System (ADS)

Chip-based atom interferometers bring together the advantages of atom chips and Bose-Einstein condensates. Their central prerequisite is that a condensate can be coherently split into two halves with a determined relative phase. This paper demonstrates the dynamical splitting and merging of an atom cloud with two U-wires on an atom chip. Symmetrical and asymmetrical splittings are realized by applying a bias field with different directions and magnitudes. The trajectories of the splitting are consistent with theoretical calculations. The atom chip is a good candidate for constructing an atom interferometer.

Ke, Min; Yan, Bo; Cheng, Feng; Wang, Yu-Zhu

2009-11-01

98

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

SciTech Connect

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.

Brodsky, Stanley J.; /SLAC

2012-02-16

99

Atoms in flight and the remarkable connections between atomic and hadronic physics  

NASA Astrophysics Data System (ADS)

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.

Brodsky, Stanley J.

100

Atoms in flight and the remarkable connections between atomic and hadronic physics  

NASA Astrophysics Data System (ADS)

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.

Brodsky, Stanley J.

2012-05-01

101

ITER: burning plasma physics experiment  

NASA Astrophysics Data System (ADS)

The ITER project has an overall programmatic objective `to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes'. The ITER tokamak design is the embodiment of the finding, endorsed by all the parties to the project, that `the full non-linear interplay between alpha-particle heating, confinement barriers and pressure and profile control, and their compatibility with a divertor can be addressed only in an integrated step'. This step involves not only the study of fusion burning plasma physics but also the demonstration of key items of fusion reactor technology. This paper introduces: magnetic fusion plasma (section 1), the physics goals of ITER (section 2) and the burning plasma physics which will be studied (section 3), examines the present ITER design and how it meets the plasma performance requirements in terms of extended burn at specific fusion power amplification (section 4), describes plasma measurements for ITER and some of the issues involved in their implementation (section 5), indicates how ITER provides a focus for international research into tokamak plasma physics (section 6), and presents a brief report on the status of the ITER Project (section 7). To conclude, this paper presents some final remarks (section 8).

Green, B. J.; ITER International Team; Participant Teams

2003-05-01

102

Efimov Physics in Atom-Dimer Scattering of Lithium6 Atoms  

Microsoft Academic Search

Lithium-6 atoms in the three lowest hyperfine states display universal\\u000aproperties when the S-wave scattering length between each pair of states is\\u000alarge. Recent experiments reported four pronounced features arising from Efimov\\u000aphysics in the atom-dimer relaxation rate, namely two resonances and two local\\u000aminima. We use the universal effective field theory to calculate the atom-dimer\\u000arelaxation rate at zero

H.-W. Hammer; Daekyoung Kang; Lucas Platter

2010-01-01

103

Physics and experiments at RHIC  

SciTech Connect

The Relativistic Heavy Ion Collider (RHIC), under construction at Brookhaven National Laboratory, will be the site of a series of experiments seeking to discover the quark-gluon plasma and elucidate its properties. Several observables should exhibit characteristic behaviors if a quark-gluon plasma is indeed created in the laboratory. Four experiments are now under construction for RHIC to measure certain of these observables over kinematic ranges where effects due to quark-gluon plasma formation should be manifest.

Young, G.R.

1995-12-31

104

Multiple species atom source for laser-cooling experiments  

SciTech Connect

We describe the design of a single beam, multiple species atom source in which the flux of any component can be separately adjusted. Using this design we have developed a {sup 23}Na-{sup 6}Li atom source for ultracold atom experiments. The fluxes of lithium and sodium are independently tunable, allowing operation as a single {sup 23}Na or {sup 6}Li source as well as a double source with equal atomic fluxes in each component.

Stan, C.A.; Ketterle, W. [Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139 (United States)

2005-06-15

105

Experiment and the foundations of quantum physics  

Microsoft Academic Search

Instead of having to rely on gedanken (thought) experiments, it is possible to base this discussion of the foundations of quantum physics on actually performed experiments because of the enormous experimental progress in recent years. For reasons of space, the author discusses mainly experiments related to the Einstein-Podolsky-Rosen paradox and Bell's theorem, that is, to quantum entanglement. Not only have

Anton Zeilinger

1999-01-01

106

Physics of the Telescope Array Experiment  

NASA Astrophysics Data System (ADS)

The Telescope Array (TA) experiment has as its aim studying ultrahigh energy cosmic rays. It consists of a surface detector (SD) of 512 scintillation counters and three fluorescence detectors overlooking the SD. The experiment is located in Millard County, Utah, and is the largest in the northern hemisphere. In this talk a description will be given of the experiment and its physics aims.

Sokolsky, Pierre

2009-05-01

107

Physical Perspectives on the Global Optimization of Atomic Clusters  

Microsoft Academic Search

In this chapter the physical aspects of the global optimization of the geometry of atomic clusters are elucidated. In particular,\\u000a I examine the structural principles that determine the nature of the lowest-energy structure, the physical reasons why some\\u000a clusters are especially difficult to optimize and how the basin-hopping transformation of the potential energy surface enables\\u000a these difficult clusters to be

Jonathan P. K. Doye

2000-01-01

108

ECR-based atomic collision physics research at ORNL  

SciTech Connect

After a brief summary of the present capability and configuration of the ORNL Multicharged Ion Research Facility (MIRF), and of upcoming upgrades and expansions, the presently on-line atomic collisions experiments are described. In the process, the utility of intense, cw ion beams extracted from ECR ion sources for low-signal rate experiments is illustrated.

Meyer, F.W.; Bannister, M.E.; Hale, J.W.; Havener, C.C. [and others

1997-04-01

109

Experiments in intermediate energy physics  

SciTech Connect

Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.

Dehnhard, D.

2003-02-28

110

Physics and Families: The Open Physics Lab and other experiences  

Microsoft Academic Search

The Orlando Science Center has constructed a modern, computer assisted laboratory for physics experiments and demonstrations, that is accessible to the general public. It is equipped with a complete line of computerized data acquisition instruments, at the level of a modern university teaching laboratory, including both ``wet'' and ``dry'' lab capabilities. The project was designed to bring the experience of

Brian Tonner

2005-01-01

111

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

ERIC Educational Resources Information Center

|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…

DETERLINE, WILLIAM A.; KLAUS, DAVID J.

112

High Temperature Facility for Atomic Physics Studies. Final Report.  

National Technical Information Service (NTIS)

The results of a program designed to develop a laser heated plasma sample for atomic physics studies in the 30 to 100 eV range of electron temperature and the 3 x 10 exp 17 to 10 exp 18 cm exp -3 range in electron density are presented. The approach used ...

1978-01-01

113

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

ERIC Educational Resources Information Center

|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…

DETERLINE, WILLIAM A.; KLAUS, DAVID J.

114

Project Physics Reader 5, Models of the Atom.  

ERIC Educational Resources Information Center

|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…

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

115

Current experiments in elementary particle physics. Revision  

SciTech Connect

This report contains summaries of 568 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1988 are excluded. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, INS (Tokyo), ITEP (Moscow), IUCF (Bloomington), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Galic, H. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Armstrong, F.E. [Lawrence Berkeley Lab., CA (United States); von Przewoski, B. [Indiana Univ. Cyclotron Facility, Bloomington, IN (United States)] [and others

1994-08-01

116

Practical Physics: Basic Experiments with Ripple Tanks  

NSDL National Science Digital Library

This resource contains a set of eight introductory experiments on wave reflections, appropriate for use in high school and middle school. Students are introduced to ripple tanks and gain confidence in using them by doing some simple experiments with pulses. SEE RELATED ITEMS on this page for a Teachers' Guide on using ripple tanks, and for ripple tank experiments for the more advanced classroom. This item is part of a much larger collection of physics/astronomy experiments, sponsored by the UK's Institute of Physics and funded by the Nuffield Curriculum Centre.

Centre, Nuffield C.

2009-03-20

117

Summary of informal meeting on ''facilities for atomic physics research with highly ionized atoms''  

SciTech Connect

An informal meeting to discuss ''Facilities for Atomic Physics Research with Highly Ionized Atoms'' was held during the APS DEAP meeting at the University of Connecticut on May 30, 1984. The meeting was motivated by the realization that the status of facilities for studies of highly ionized atoms is unsettled and that it might be desirable to take action to ensure adequate resources for research over the whole range of charge states and energies of interest. It was assumed that the science to be done with these beams has been amply documented in the literature.

Cocke, C.L.; Jones, K.W.

1984-01-01

118

The ATHENA Experiment - Production of Antihydrogen Atoms  

Microsoft Academic Search

Antihydrogen is of fundamental interest as a test bed for fundamental symmetries such as CPT invariance. As hydrogen is arguably the most well understood quantum mechanical system in physics, it is natural to consider precision comparisons of the properties of hydrogen and antihydrogen. Any discrepancy, for example, in the spectra of the two systems would be an indication of physics

Jeffrey S. Hangst

2004-01-01

119

Atomic physics with highly charged ions. Progress report  

SciTech Connect

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.

Richard, P.

1994-08-01

120

PHOBOS experiment at RHIC: physics and capabilities.  

National Technical Information Service (NTIS)

The PHOBOS experiment at RHIC is designed to study multiplicity distributions and fluctuations over all of 4(pi), as well as particle spectra and correlations at mid rapidity, with a particular emphasis on physics at low p(sub T). The experiment is relati...

B. B. Back

1998-01-01

121

Low-Cost Accelerometers for Physics Experiments  

ERIC Educational Resources Information Center

|The implementation of a modern game-console controller as a data acquisition interface for physics experiments is discussed. The investigated controller is equipped with three perpendicular accelerometers and a built-in infrared camera to evaluate its own relative position. A pendulum experiment is realized as a demonstration of the proposed…

Vannoni, Maurizio; Straulino, Samuele

2007-01-01

122

Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

|Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)|

Fan, Qinbai; And Others

1995-01-01

123

Simple Experiments on the Physics of Vision  

Microsoft Academic Search

The experiments related to the physics of perception, particularly those concerning the visual system, are particularly attractive: by using only extremely simple materials it is possible to get amazing results. The experiments based on the working of the eyes can be easily understood from the basic principles of geometrical optics. The analysis of what happens in the retina after the

Adolf Cortel Ortuño

2004-01-01

124

Present and future projects of TMU Atomic Physics Group  

NASA Astrophysics Data System (ADS)

The experimental atomic physics group of Tokyo Metropolitan University now intensively promotes three projects: (1) research of huge molecular ions by a liquid-nitrogen-cooled electrostatic ion storage ring, (2) research of highly-charged ion interaction with a crystal using high-energy heavy-ion storage ring, and (3) research of the very low-energy ion-atom interaction through ion swarms in helium gas cooled down to 4 K. In this report, these projects are briefly introduced in a comprehensive manner.

Azuma, Toshiyuki; Tanuma, Hajime; Shiromaru, Haruo

2004-01-01

125

Los Alamos free atomic tritium beta decay experiment  

SciTech Connect

An apparatus is under construction at Los Alamos to measure the beta spectrum of free tritium atoms and molecules. The tritium atoms decay in a gaseous windowless source and are analyzed by a Tret'yakov type toroidal field beta spectrometer. The ultimate sensitivity of the experiment to electron antineutrino mass is expected to be <10 eV.

Knapp, D.A.; Bowles, T.J.; Browne, J.C.; Burritt, T.H.; Cohen, J.S.; Helffrich, J.A.; Maley, M.P.; Martin, R.L.; Robertson, R.G.H.; Wilkerson, J.F.

1984-01-01

126

Experiments in Fundamental Physics Scheduled and in Development for the ISS  

Microsoft Academic Search

This is a review of those experiments in the area of Fundamental Physics that are either approved by ESA and NASA, or are currently under development, which are to be performed in the microgravity environment of the International Space Station. These experiments cover the physics of liquid Helium (SUE, BEST, MISTE, DYNAMX, and EXACT), ultrastable atomic clocks (PHARAO, PARCS, RACE),

C. Lammerzahl; G. Ahlers; N. Ashby; M. Barmatz; P. L. Biermann; H. Dittus; V. Dohm; R. Duncan; K. Gibble; J. Lipa; N. Lockerbie; N. Mulders; C. Salomon

2004-01-01

127

Atomic collision and spectroscopy experiments with ultra-low-energy antiprotons  

NASA Astrophysics Data System (ADS)

Antiproton, the antiparticle of proton, is a unique projectile in the study of atomic collision physics, which can be treated theoretically either as a 'negative proton' or a 'heavy electron'. Atomic capture of an antiproton will result in formation of a highly excited exotic atom. Antiprotonic helium atom has been studied intensively by means of precision laser spectroscopy, which has led to a stringent determination of antiproton mass and charge to a level of ppb. Comparison of these values with those of proton gives one of the best tests of CPT invariance, the most fundamental symmetry in physics. However, the dynamic processes of antiproton capture remain unclarified. With an aim to produce an antiproton beam at atomic-physics energies for 'pure' collision experiments, we have so far developed techniques to decelerate, cool and confine antiprotons in vacuo, using a sequential combination of the Antiproton Decelerator (AD) at CERN, a Radio-Frequency Quadrupole Decelerator (RFQD), and an electromagnetic trap. Our recent success in stable extraction of monoenergetic ultra-slow antiprotons, about 3 × 105 in number available every 5 minutes, has opened up the possibility to study ionization and atomic capture processes between an antiproton and an atom under the single collision condition. Our design and strategy of the cross-beam experiments are presented, together with technical challenges in the detection system to identify the rare events with a reaction rate of 10-4.

Torii, Hiroyuki A.; Nagata, Yugo; Toyoda, Hiroshi; Imao, Hiroshi; Kuroda, Naofumi; Varentsov, Victor L.; Yamazaki, Yasunori; Asacusa Collaboration

2009-09-01

128

Atomic Physics at Accelerators: Laser Spectroscopy and Applications  

NASA Astrophysics Data System (ADS)

From 19 to 24 September, 1999, the First European Conference Atomic Physics at Accelerators: Laser Spectroscopy and Applications (APAC'99) was held at University of Mainz and Schloss Waldhausen (Budenheim, Germany) under the chairmanship of H. Backe and G. Huber. The idea of this up-to-date conference was associated with the 65th anniversary of Professor Ernst Otten (University of Mainz) who, together with H. Kluge, contributed much to the development of this work at CERN, University of Mainz, and Darmstadt.

Letokhov, Vladilen

129

Axiomatizing physical experiments as oracles to algorithms.  

PubMed

We developed earlier a theory of combining algorithms with physical systems, on the basis of using physical experiments as oracles to algorithms. Although our concepts and methods are general, each physical oracle requires its own analysis, on the basis of some fragment of physical theory that specifies the equipment and its behaviour. For specific examples of physical systems (mechanical, optical, electrical), the computational power has been characterized using non-uniform complexity classes. The powers of the known examples vary according to assumptions on precision and timing but seem to lead to the same complexity classes, namely P/log* and BPP//log*. In this study, we develop sets of axioms for the interface between physical equipment and algorithms that allow us to prove general characterizations, in terms of P/log* and BPP//log*, for large classes of physical oracles, in a uniform way. Sufficient conditions on physical equipment are given that ensure a physical system satisfies the axioms. PMID:22711864

Beggs, Edwin J; Costa, José Félix; Tucker, John V

2012-07-28

130

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

SciTech Connect

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.

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

1988-12-01

131

COSY Data Acquisition System for Physical Experiments  

Microsoft Academic Search

For nuclear physics experiments at the internal and external beam of the Julich Cooler Synchrotron COSY, a three-level data processing and acquisition system shall be developed. Signals from various detector arrangements are digitized and preprocessed by CAMAC, FASTBUS and VME modules. A multiprocessor system based on VMEbus is used for event-building, data recording and buffered data -fer to the host

W. Erven; J. Holzer; H. Kopp; H. W. Loevenich; W. Meilingl; K. Zwoll; M. Kamadi; R. Nellen; K.-H. Watzlawik

1991-01-01

132

The Physics of the Imploding Can Experiment  

ERIC Educational Resources Information Center

|One of the popular demonstrations of atmospheric pressure in introductory physics courses is the "crushing can" or "imploding can" experiment. In this demonstration, which has also been extensively discussed on the Internet, a small amount of water is placed in a soda can and heated until it boils and water vapor almost entirely fills the can.…

Mohazzabi, Pirooz

2010-01-01

133

Atomic physics at the Argonne PII ECR (electron cyclotron resonance) Ion Source  

SciTech Connect

An atomic physics beam line has been set up at the Argonne PII ECR Ion Source. The source is on a 350-kV high-voltage platform which is a unique feature of particular interest in work on atomic collisions. We describe our planned experimental program which includes: measurement of state-selective electron-capture cross sections, studies of doubly-excited states, precision spectroscopy of few-electron ions, tests of quantum electrodynamics, and studies of polarization transfer using optically pumped polarized alkali targets. The first experiments will be measurements of cross sections for electron capture into specific nl subshells in ion-atom collisions. Our method is to observe the characteristic radiation emitted after capture using a VUV spectrometer. Initial data from these experiments are presented. 12 refs., 4 figs.

Dunford, R.W.; Berry, H.G.; Billquist, P.J.; Pardo, R.C.; Zabransky, B.J.; Bakke, E.; Groeneveld, K.O.; Hass, M.; Raphaelian, M.L.A.

1987-01-01

134

LEO Atomic Oxygen Measurements: Experiment Design and Preliminary Results  

Microsoft Academic Search

Recently two University of Southampton flight experiments intended to measure the LEO atomic oxygen (AO) flux or fluence have been launched. The first forms part of the Southampton Transient Oxygen and Radiation Monitor (STORM) instrument package that is included as part of the European Materials Exposure and Degradation Experiment on EuTEF (MEDET) module now residing on the external pay load

G. T. Roberts; A. R. Chambers; C. B. White

2009-01-01

135

Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source  

SciTech Connect

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.

Jones, K.W.; Johnson, B.M.; Meron, M.

1986-01-01

136

(Atomic physics with large electrostatic accelerators): Foreign trip report, May 14, 1989--June 9, 1989  

SciTech Connect

The traveler attended the First International Symposium on Swift Heavy Ions in Matter (SHIM '89) in Caen, France, and presented a paper on ''Dielectronic and Direct Excitation of Channeled Ions.'' He then participated in the 5th International Conference on Electrostatic Accelerators and Associated Boosters (Strasbourg, France, and Heidelberg, West Germany) and presented an invited lecture on ''Atomic Physics with Large Electrostatic Accelerators.'' The traveler visited the University of Aarhus (Denmark), where discussions were held on the present status of ASTRID; forthcoming collaborative experiments at CERN; dielectronic and radiative recombination experiments; charge dependence of double excitation and excitation-ionization collisions in helium; and crystal preparation for ORNL experiments in channeling.

Datz, S.

1989-06-12

137

A new ECR ion source for atomic physics research at Institute of Modern Physics  

Microsoft Academic Search

A new electron cyclotron resonance (ECR) ion source (LECR3-Lanzhou Electron Cyclotron Resonance Ion Source No. 3) has been constructed this year. The main purpose of this source is to provide highly charged ion beams for atomic physics and surface physics research. The design of this ion source is based on the IMP 14.5 GHz ECR ion source (LECR2-Lanzhou Electron Cyclotron

Z. M. Zhang; H. W. Zhao; X. Z. Zhang; X. H. Guo; X. X. Li; L. T. Sun; Y. Cao; Y. C. Feng; J. Y. Li; H. L. Lei; H. Wang; J. Y. Gao; B. H. Ma

2002-01-01

138

Microwave ionization of highly excited hydrogen atoms: Experiment and theory  

Microsoft Academic Search

This article elaborates on a talk delivered by the first author at the First International Conference on the Physics of Phase Space (University of Maryland, 20–23 May 1986). It reviews briefly our still limited, but rapidly growing understanding of a dynamical process, the ionization of highly-excited hydrogen atoms by a microwave electric field. Classical dynamics explains surprisingly well many recent

P. Koch; K. van Leeuwen; O. Rath; D. Richards; R. V. Jensen

1987-01-01

139

ATOMIC AND MOLECULAR PHYSICS: Bose-Einstein condensation on an atom chip  

NASA Astrophysics Data System (ADS)

This paper reports an experiment of creating Bose-Einstein condensate (BEC) on an atom chip. The chip-based Z-wire current with a homogeneous bias magnetic field creates a tight magnetic trap, which allows for a fast production of BEC. After a 4.17-s forced radio frequency evaporative cooling, a condensate with about 3000 atoms appears. The transition temperature is about 300 nK. This compact system is quite robust, allowing for versatile extensions and further studying of BEC.

Yan, Bo; Cheng, Feng; Ke, Min; Li, Xiao-Lin; Tang, Jiu-Yao; Wang, Yu-Zhu

2009-10-01

140

Connecting High School Physics Experiences, Outcome Expectations, Physics Identity, and Physics Career Choice: A Gender Study  

ERIC Educational Resources Information Center

|This study explores how students' physics identities are shaped by their experiences in high school physics classes and by their career outcome expectations. The theoretical framework focuses on physics identity and includes the dimensions of student performance, competence, recognition by others, and interest. Drawing data from the Persistence…

Hazari, Zahra; Sonnert, Gerhard; Sadler, Philip M.; Shanahan, Marie-Claire

2010-01-01

141

Atomic physics effects on dissipative toroidal drift wave stability  

SciTech Connect

The effects of atomic physics processes such as ionization, charge exchange, and radiation on the linear stability of dissipative drift waves are investigated in toroidal geometry both numerically and analytically. For typical TFTR and TEXT edge parameters, overall linear stability is determined by the competition between the destabilizing influence of ionization and the stabilizing effect due to the electron temperature gradient. An analytical expression for the linear marginal stability condition, {eta}{sub e}{sup crit}, is derived. The instability is most likely to occur at the extreme edge of tokamaks with a significant ionization source and a steep electron density gradient.

Beer, M.A.; Hahm, T.S.

1992-02-01

142

Atomic physics and the cosmological 21 cm signal  

NASA Astrophysics Data System (ADS)

Upcoming low-frequency radio interferometers, such as MWA and SKA, offer the prospect of using 21 cm tomography to map the evolution of hydrogen reionization. The existence of a detectable signal is dependent upon the existence of a background of Lyman alpha photons able to decouple the 21 cm spin temperature from that of the CMB. In this talk, I will discuss the details of the relevant atomic physics and compare the results of simulations and analytical calculations of the effect of inhomogeneities in the Lya and X-ray background on the 21 cm power spectrum.

Pritchard, Jonathan

2010-03-01

143

Using Quantum Coherence to Enhance Gain in Atomic Physics  

NASA Astrophysics Data System (ADS)

Quantum coherence and interference effects in atomic and molecular physics have been extensively studied because of intriguing counterintuitive physics and potential important applications. Here we present one such application, i.e. using quantum coherence to generate and enhance gain in the extreme ultra-violet (XUV)(@58.4nm in Helium) and infra-red (@794.76nm in Rubidium) regimes of electromagnetic radiation. We show that using moderate external coherent drive, a substantial enhancement in the output energy on the lasing transition can be achieved under optimal conditions. We also discuss the role of coherence. The present paper is intended to be pedagogical on this subject of coherence-enhanced lasing.

Jha, Pankaj K.

2013-06-01

144

Using the Wiimote in Introductory Physics Experiments  

NASA Astrophysics Data System (ADS)

The Wii is a very popular gaming console. An important component of its appeal is the ease of use of its remote controller, popularly known as a Wiimote. This simple-looking but powerful device has a three-axis accelerometer and communicates with the console via Bluetooth protocol. We present two experiments that demonstrate the feasibility of using the Wiimote in introductory physics experiments. The linear dependence of centripetal acceleration on the radial distance at constant angular velocity is verified and compared with data obtained using photogate timers. A second application to simple harmonic oscillators tests the capabilities of the Wiimote to measure variable accelerations.

Ochoa, Romulo; Rooney, Frank G.; Somers, William J.

2011-01-01

145

Experiments with atoms captured in a dark light trap  

SciTech Connect

Sodium atoms have been loaded from a slowed beam into a dark magneto-optical trap which confines atoms mostly in the non-absorbing F=1 ground state. This method has allowed us to achieve samples of more than 10{sup 10} atoms with optical densities in excess of 150. Temperatures around 1.2 mK and densities around 10{sup 12} cm{sup -3} have been measured using weak probe absorption. At this density an elastic collisions rate is already approximately 100 Hz. Our goal is to reach the regime where the rate is high enough to allow evaporative cooling of the trapped sample enroute to Bose-Einstein Condensation, for which yet higher densities and lower temperatures are required. We report the current status of experiments underway to further increase the phase space density of the trapped atoms by cooling with polarization-gradient molasses and reloading them into a magnetic trap with a spherical quandrupole field.

Joffe, M.A.; Davis, K.B.; Ketterle, W. [and others

1993-05-01

146

Finding the Atomic Configuration with a Required Physical Property in Multi-Atom Structures  

SciTech Connect

In many problems in molecular and solid state structures one seeks to determine the energy-minimizing decoration of sites with different atom types. In other problems, one is interested in finding a decoration with a target physical property (e.g. alloy band gap) within a certain range. In both cases, the sheer size of the configurational space can be horrendous. We present two approaches which identify either the minimum-energy configuration or configurations with a target property for a fixed underlying Bravais lattice. We compare their efficiency at locating the deepest minimum energy configuration of face centered cubic Au-Pd alloy. We show that a global-search genetic-algorithm approach with diversity-enhancing constraints and reciprocal-space mating can efficiently find the global optimum, whereas the local-search virtual-atom approach presented here is more efficient at finding structures with a target property.

d'Avezac, M.; Zunger, A.

2007-01-01

147

Surface science experiments involving the atomic force microscope  

NASA Astrophysics Data System (ADS)

Three diverse first author surfaces science experiments conducted by Sean P. McBride1-3 will be discussed in detail and supplemented by secondary co-author projects by Sean P. McBride,4-7 all of which rely heavily on the use of an atomic force microscope (AFM). First, the slip length parameter, b of liquids is investigated using colloidal probe AFM. The slip length describes how easily a fluid flows over an interface. The slip length, with its exact origin unknown and dependencies not overwhelming decided upon by the scientific community, remains a controversial topic. Colloidal probe AFM uses a spherical probe attached to a standard AFM imaging tip driven through a liquid. With the force on this colloidal AFM probe known, and using the simplest homologous series of test liquids, many of the suspected causes and dependencies of the slip length demonstrated in the literature can be suppressed or eliminated. This leaves the measurable trends in the slip length attributed only to the systematically varying physical properties of the different liquids. When conducting these experiments, it was realized that the spring constant, k, of the system depends upon the cantilever geometry of the experiment and therefore should be measured in-situ. This means that the k calibration needs to be performed in the same viscous liquid in which the slip experiments are performed. Current in-situ calibrations in viscous fluids are very limited, thus a new in-situ k calibration method was developed for use in viscous fluids. This new method is based upon the residuals, namely, the difference between experimental force-distance data and Vinogradova slip theory. Next, the AFM's ability to acquire accurate sub nanometer height profiles of structures on interfaces was used to develop a novel experimental technique to measure the line tension parameter, tau, of isolated nanoparticles at the three phase interface in a solid-liquid-vapor system. The tau parameter is a result of excess energy caused by the imbalance of the complex intermolecular forces experienced at the three phase contact line. Many differences in the sign and magnitude of the tau parameter exist in the current literature, resulting in tau being a controversial topic.

McBride, Sean P.

148

The physics of spin-polarized atomic vapors  

NASA Astrophysics Data System (ADS)

The overall objective of the work supported by the Air Force Office of Scientific Research grant has been to explore the basic physical properties of spin polarized atomic vapors. These systems are of considerable interest to the civilian and military sectors of our society because they can be used to make very precise measurements of time, absolute rotation rates, and electromagnetic fields. For example, the U.S. time standard is the atomic cesium hyperfine frequency; very precise atomic frequency standards are used in satellites and on Earth for a wide variety of uses. Optically pumped magnetometers are used by the oil and mining industry for prospecting, by archaeologists for locating lost cities and sunken treasure ships, and by the navy for location of submarines. Optically pumped systems are currently being developed for use as gyroscopes which may have real advantages in terms of ruggedness and economy. In spite of the widespread practical utility of these systems, there is only limited research going on the related areas. There are no more than a dozen active research groups world wide and most are in foreign countries, including several excellent laboratories in the Soviet bloc. The goal of this work has been to maintain a center of excellence for the study of spin polarized atomic vapors, to ensure that outstanding students are introduced to the field from time to time and to coordinate our research activities with the needs of industrial and government laboratories for critical information and the needs of the university for high-quality basic research.

Happer, W.

1979-08-01

149

The physics design of the Tokamak Physics Experiment  

SciTech Connect

The physics approaches to improved, steady-state tokamak reactors, as evolved through reactor design studies, ideas based on experimental results, and better theoretical understanding, are the foundation for the mission and physics design of the Tokamak Physics Experiment (TPX). The mission of TPX is to develop the scientific basis for cost-competitive, continuously operating tokamak power plants. We report here the design status of TPX, a device optimized to achieve improved performance through strong plasma shaping, recycling control, and current profile shaping, while operating continuously. The design incorporates poloidal field flexibility for a wide range of operation in normalized beta and internal inductance, a double-null ``Vee`` divertor configuration for power and particle control, internal and external n {ne} 0 coils, as well as passive stabilizers, for control of MHD activity, and remote maintenance for continuous high-power operation in deuterium. Having superconducting poloidal and toroidal coils, the TPX device itself is capable of continuous operation, although initially auxiliary equipment limits the pulse length to 1000 sec.

Thomassen, K.I. [Lawrence Livermore National Lab., CA (United States); Batchelor, D.B. [Oak Ridge National Lab., TN (United States); Bialek, J. [Princeton Univ., NJ (United States). Plasma Physics Lab.] [and others

1994-08-08

150

Atomic Physics Using Ultra-Intense X-Ray Pulses  

NASA Astrophysics Data System (ADS)

The combination of short wavelengths and ultrahigh intensities as provided by the new soft and hard X-ray free electron laser sources opens the doorway to totally new experiments on photon-matter interaction. It concerns, in particular, new classes of nonlinear inner-atomic processes. In the present contribution, recent results on sequential and nonsequential multi-photon ionization of gas phase targets are presented and discussed; including processes where also inner shells are affected. Moreover, examples are given how linear and nonlinear photoionization may be used for online photon diagnostics at these new radiation sources.

Martins, M.; Meyer, M.; Richter, M.; Sorokin, A. A.; Tiedtke, K.

151

Physics of colloids in space experiment  

NASA Astrophysics Data System (ADS)

The Physics of Colloids in Space (PCS) experiment was proposed by investigators Weitz and Pusey. It is scheduled to be conducted on the International Space Station (ISS) in the year 2000. The broader objective is to study physics of colloidal particles dispersed in a fluid. This includes nucleation and growth of colloidal crystals and behavior of binary colloidal crystal alloys. The structure and properties of colloidal particles with attractive interactions (depletion interactions) induced by the addition of a non-adsorbing polymer, behavior of large-scale fractal aggregates, and gels will also be studied. A multi-purpose light scattering apparatus will be employed in these studies. This apparatus is being designed and built by the NASA Lewis Research Center and is capable of performing dynamic light scattering (DLS), static light scattering (SLS), and Bragg scattering experiments. The flight experiment hardware will be located on the EXPRESS rack mounted in the ISS US Laboratory Module. It is anticipated that the long-term benefit of this research will be to fabricate novel materials that may have applications in opto-electronic display technology. Materials could be fabricated that could act as light switches and could control the direction or color of the displayed light.

Ansari, Rafat R.; Hovenac, Edward A.; Sankaran, Subramanian; Koudelka, John M.; Weitz, David A.; Cipelletti, Luca; Segre, Phillip N.

1999-01-01

152

Photonic doppler velocimetry in shock physics experiments  

NASA Astrophysics Data System (ADS)

Doppler velocimetry techniques are frequently used in Shock-Physics experiments to measure material velocities (as a function of time). With such diagnostics, there is no physical contact between the probe and the target, which presents the advantage of not intruding the observed phenomenon. They also provide very good precision on the velocities. Those techniques are either based on homodyne methods (such as Fabry-Pérot and Visar) or on heterodyne methods (such as PDV-Photon Doppler Velocimetry). In particular, PDV technique has recently been developed at LLNL. We present in this paper a PDV system built at CEA DIF, along with our first experimental results which we obtained on a shock tube.

Mercier, P.; Benier, J.; Azzolina, A.; Lagrange, J. M.; Partouche, D.

2006-08-01

153

The Physics of the Imploding Can Experiment  

NASA Astrophysics Data System (ADS)

One of the popular demonstrations of atmospheric pressure in introductory physics courses is the ``crushing can'' or ``imploding can'' experiment.1-4 In this demonstration, which has also been extensively discussed on the Internet, a small amount of water is placed in a soda can and heated until it boils and water vapor almost entirely fills the can. The can is then quickly inverted and its opening is allowed to touch the surface of cold water in a container. Upon touching the cold water surface, the can implodes in a fraction of a second as the water vapor in the can condenses.

Mohazzabi, Pirooz

2010-05-01

154

Collision physics in the atomic and molecular universe  

NASA Astrophysics Data System (ADS)

The wavelength range and high resolution of the space instruments Chandra, Newton, SOHO, Suzaku, Herschel, Spitzer, and the upcoming ASTRO-H and James Webb Space Telescope have increased the need for laboratory collision-physics measurements to interpret astrophysical phenomena. A review will be given of charge exchange of highly-charged ions with neutral comet and planet atmospheres; and the formation of complex molecules in stellar regions. These space observations are linked to laboratory measurements of absolute charge-exchange cross sections; and molecular formation of species such as CO2, CH3OH, and CH3CH2OH involving fast H- and O-atom collisions with abundant interstellar molecules adsorbed on dust-grain analogues.

Chutjian, A.; Simcic, J.; Madzunkov, S. M.; MacAskill, J. A.; Mawhorter, R. J.; Tsikata, E.

2012-11-01

155

The laboratory experience in introductory physics courses  

NASA Astrophysics Data System (ADS)

The last two decades or so have witnessed intense efforts to improve the teaching and learning of physics. Scholarly studies have provided the grounding for many projects which reform the structure of introductory courses. A number of these innovations, however, are resource intensive, or depend on the ability to introduce changes in areas which are beyond the control of the faculty (e.g., scheduling), thus inhibiting their implementation. An alternative strategy that overcomes these obstacles is to modify the nature of the laboratory experience (a component that practically nobody disputes is an essential part of the introductory course), to provide hands-on learning opportunities that differ from the traditional ``follow-this-recipe-to-verify-this-law'' approach. I have chosen to implement a variety of activities that support the overall objectives of the course: developing conceptual understanding and transferable skills, and providing practice in the ways scientists actually do science. Given the audience in this two-semester, algebra-based course, mostly biology majors and pre-professionals (health-related careers, such as medicine, physical therapy, and veterinary), these goals were identified as the most important and lasting contribution that a physics course can make to the students intellectual development. I offer here examples of the types of hands on activities that I have implemented, organized for the sake of this presentation in four rather loose categories, depending on which subset of the course objectives the activities mostly address: self-designed lab activities, discussion of demo-type activities, building concepts from simple to complex, and out-of-lab physical phenomena.

di Stefano, Maria C.

1997-03-01

156

The Atomic Era: A new interdisciplinary course combining physics, the humanities and the social sciences  

NASA Astrophysics Data System (ADS)

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.

Carstens-Wickham, Belinda

2001-05-01

157

Industry roles in the Tokamak Physics Experiment  

SciTech Connect

The Tokamak Physics Experiment (TPX) is the first major fusion project opportunity in many years for US industry. Both the TPX management and the Department of Energy`s Office of Fusion Energy are committed to creating industry roles that are integrated throughout the project and that appropriately use the capabilities they offer. To address industry roles in TPX it is first appropriate to describe the collaborative national approach taken for this program. The Director of the Princeton Plasma Physics Laboratory (PPPL) was asked by DOE to set up this national team structure, and the current senior management positions and delegated responsibilities reflect that approach. While reporting lines and delegated roles are clear in the organization chart for TPX, one way to view, it, different from that of the individuals responsible upward through this management structure for various elements of the project, is through institutional responsibilities to the senior management team. In this view the management team relies on several national laboratories, each using industry contracts for major sub-systems and components, to execute the project. These responsibilities for design and for contracting are listed, showing that all major contracts will come through three national laboratories, forming teams for their responsible activities.

Thomassen, K.I. [Lawrence Livermore National Lab., CA (United States)

1994-09-01

158

The Role of Atomic Physics in Understanding Physical Processes in High Energy Astrophysics  

NASA Astrophysics Data System (ADS)

X-ray grating spectra from Chandra and XMM-Newton have provided new insights into many of the physical processes present in astrophysical sources. For example, (i) shocks produced by magnetic accretion onto stellar surfaces cool as the material flows down, with density and temperature diagnostics providing tests of the accretion models; (ii) many active galactic nuclei (AGN) produce winds or outflows, detectable through X-ray absorption; (iii) active cool stars have coronal pressures several orders of magnitude larger than found on the Sun. The diagnostics used to determine temperatures, densities, elemental abundances, ionization states, and opacities require extremely accurate atomic data. At the same time, we must have a fairly complete database in order to ensure that the diagnostics are not blended or otherwise compromised. The best spectra are from bright objects with long exposures (days), but the information contained allows us to infer the location(s) of the emitting and absorbing plasmas and understand the physical properties. We will give examples to illustrate the role of atomic physics in our analyses of such spectra and the quality of data required.

Brickhouse, Nancy S.

2007-08-01

159

The Role of Atomic Physics in Understanding Physical Processes in High Energy Astrophysics  

SciTech Connect

X-ray grating spectra from Chandra and XMM-Newton have provided new insights into many of the physical processes present in astrophysical sources. For example (i) shocks produced by magnetic accretion onto stellar surfaces cool as the material flows down, with density and temperature diagnostics providing tests of the accretion models; (ii) many active galactic nuclei (AGN) produce winds or outflows, detectable through X-ray absorption; (iii) active cool stars have coronal pressures several orders of magnitude larger than found on the Sun.The diagnostics used to determine temperatures, densities, elemental abundances, ionization states, and opacities require extremely accurate atomic data. At the same time, we must have a fairly complete database in order to ensure that the diagnostics are not blended or otherwise compromised. The best spectra are from bright objects with long exposures (days), but the information contained allows us to infer the location(s) of the emitting and absorbing plasmas and understand the physical properties. We will give examples to illustrate the role of atomic physics in our analyses of such spectra and the quality of data required.

Brickhouse, Nancy S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS 15, Cambridge, MA 02138 (United States)

2007-08-02

160

Atomic physics and quantum optics using circuits: An overview of recent results on superconducting qubits  

NASA Astrophysics Data System (ADS)

Superconducting (SC) circuits can behave like atoms making transitions between a few energy levels. Such circuits can test quantum mechanics at macroscopic scales and be used to conduct atomic-physics experiments on a silicon chip. This presentation overviews a few of our theoretical studies on SC circuits and quantum information processing including: SC qubits for photon generation and for lasing; 2-1 photon coexistence; cooling qubits and their environment; using SC qubits to probe nearby defects; hybrid circuits involving both charge and flux qubits; quantum tomography in SC circuits; preparation of macroscopic quantum superposition states of a cavity field via coupling to a SC qubit; generation of nonclassical photon states using a SC qubit in a microcavity; cluster states; using these circuits as quantum analog emulators of Kitaev lattices; controllable scattering of photons inside a one-dimensional resonator waveguide; and controllable couplings among qubits.

Nori, Franco

2010-03-01

161

Physics evaluation of compact tokamak ignition experiments  

SciTech Connect

At present, several approaches for compact, high-field tokamak ignition experiments are being considered. A comprehensive method for analyzing the potential physics operating regimes and plasma performance characteristics of such ignition experiments with O-D (analytic) and 1-1/2-D (WHIST) transport models is presented. The results from both calculations are in agreement and show that there are regimes in parameter space in which a class of small (R/sub o/ approx. 1-2 m), high-field (B/sub o/ approx. 8-13 T) tokamaks with aB/sub o/S/q/sub */ approx. 25 +- 5 and kappa = b/a approx. 1.6-2.0 appears ignitable for a reasonable range of transport assumptions. Considering both the density and beta limits, an evaluation of the performance is presented for various forms of chi/sub e/ and chi/sub i/, including degradation at high power and sawtooth activity. The prospects of ohmic ignition are also examined. 16 refs., 13 figs.

Uckan, N.A.; Houlberg, W.A.; Sheffield, J.

1985-01-01

162

COSY data acquisition system for physical experiments  

SciTech Connect

This paper reports that for nuclear physics experiments at the internal and external beam of the Julich Cooler Synchrotron COSY, a three-level data processing and acquisition system is developed. Signals from various detector arrangements are digitized and preprocessed by CAMAC, FASTBUS and VME modules. A multiprocessor system based on VME bus is used for event-building, data recording and buffered data transfer to the host computer. All crates are connected by parallel VICbus. For this, an intelligent CAMAC crate controller with VICbus is under development. Microcomputer-based VME modules are equipped with CPU's of the 680XO family, working under OS-9 real-time operating system. The data acquisition system is mainly based on commercially available modules. For experiment control and data analysis, workstations as part of a local cluster are provided. Proprietary standards developed at CERN, together with OSF open standards will be implemented. TCP/IP protocols for VMEbus masters and host computer serve for initialization and command transfer.

Erven, W.; Holzer, J.; Kopp, H.; Loevenich, H.W.; Meiling, W.; Zwoll, K. (Forschungszentrum Juelich, Zentrallabor fuer Elektronik (DE)); Karnadi, M.; Nellen, R.; Watzlawik, K.H. (Forschungszentrum Juelich, Inst. fuer Kemphysik (DE))

1992-04-01

163

Precision observables for particle physics experiments  

NASA Astrophysics Data System (ADS)

The objective of this thesis is to develop tools for interpretation of the upcoming particle physics experiments. We implement and test Optimal Jet Finder (OJF), a jet finding algorithm that is based on the global energy flow in the event. OJF is infrared and collinear safe and resolves overlapping jets dynamically. The shapes of jets are determined dynamically and are not geometrical cones. However, they are more regular than those resulting from k?, which should facilitate detector calibration of OJF. We compare the statistical uncertainties of the W-boson mass when using three different jet finding algorithms: k? . JADE, and OJF. We find that OJF gives the same accuracy as k ? but is faster than k? if a large number of calorimeter cells is analyzed. We present the details of FORTRAN 77 and object-oriented C++ implementations of OJF. We calculate the rate of the lepton flavour violating mu ? e + gamma decay in a particular Grand Unification SO(10) model by Albright and Barr. We assume the Constrained Minimal Supersymmetric Standard Model framework. We interpret the results in view of the recent cosmological observations from Wilkinson Microwave Anisotropy Probe. We find that the SO(10) model is consistent with the experimental limits on the mu ? e + gamma branching ratio over a large volume of the supersymmetric parameter space. However, if the branching ratio is further constrained by the MEG experiment, carried out in the Paul Scherrer Institute, below 10 -13, the available volume of the parameter space will be significantly reduced. We calculate the QED suppression of the rate of the lepton flavour violating mu ? e + gamma decay. The result, does not depend on the details of the mechanism that, is responsible for the lepton flavour violation, except for the mass scale that enters the final expression. If this mass scale is between 100 and 1000 GeV, the numerical value of the decrease in the decay rate is between 12% and 17%. If the rare muon decay is observed in the MEG experiment, our result will enhance the precision with which the parameters of the new physics models responsible for this decay can be extracted.

Jankowski, Ernest

164

Proof-of-concept experiments for quantum physics in space  

Microsoft Academic Search

Quantum physics experiments in space using entangled photons and satellites are within reach of current technology. We propose a series of fundamental quantum physics experiments that make advantageous use of the space infrastructure with specific emphasis on the satellite-based distribution of entangled photon pairs. The experiments are feasible already today and will eventually lead to a Bell-experiment over thousands of

Rainer Kaltenbaek; Markus Aspelmeyer; Thomas Jennewein; Caslav Brukner; Anton Zeilinger; Martin Pfennigbauer; Walter R. Leeb

2004-01-01

165

AGS experiments in nuclear/QCD physics at medium energies  

SciTech Connect

This report contains a diagram of the experimental setup for each experiment as well as giving a brief discussion of its purpose and list of collaborators for the experiment. Thirty-one experiments in the areas of nuclear physics and particle physics are covered. It concludes with a list of publications of the AGS experiments.

Lo Presti, P.

1998-07-01

166

EDITORIAL: First merged issue of Journal of Physics B: Atomic, Molecular and Optical Physics with Journal of Optics B: Quantum and Semiclassical Optics  

Microsoft Academic Search

With the first issue of 2006 Journal of Physics B: Atomic, Molecular and Optical Physics (J. Phys. B) has successfully incorporated the former journal J. Opt. B. Under the well known and recognized name Journal of Physics B: Atomic, Molecular and Optical Physics the new merged journal will have a much wider scope, serving both the atomic, molecular and optical

J.-M. Rost

2006-01-01

167

First merged issue of Journal of Physics B: Atomic, Molecular and Optical Physics with Journal of Optics B: Quantum and Semiclassical Optics  

Microsoft Academic Search

With the first issue of 2006 Journal of Physics B: Atomic, Molecular and Optical Physics (J. Phys. B) has successfully incorporated the former journal J. Opt. B. Under the well known and recognized name Journal of Physics B: Atomic, Molecular and Optical Physics the new merged journal will have a much wider scope, serving both the atomic, molecular and optical

J-M Rost

2006-01-01

168

ATOMIC AND MOLECULAR PHYSICS: Surface-induced evaporative cooling  

NASA Astrophysics Data System (ADS)

The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is < 100 ?m. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is > 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.

Ke, Min; Yan, Bo; Cheng, Feng; Wang, Yu-Zhu

2009-10-01

169

Industry roles in the Tokamak Physics Experiment  

SciTech Connect

There are several distinguishing features of the Tokamak Physics Experiment (TPX) to be found in the TPX program and in the organizations for constructing and operating the machine. Programmatically, TPX addresses several issues critical to the viability of magnetic fusion power plants. Organizationally, it is a multi-institutional partnership to construct and operate the machine and carry out its program mission. An important part of the construction partnership is the integrated industrial responsibility for design, R&D, and construction. The TPX physics design takes advantage of recent research on advanced tokamak operating modes achieved for time scales of the order of seconds that are consistent with continuous operation. This synergism of high performance (higher power density) modes with plasma current driven mostly by internal pressure (boot-strap effect) points toward tokamak power plants that will be cost-competitive and operate continuously. A large fraction of the project is subcontracted to industry. By policy, these contracts are at a high level in the project breakdown of work, giving contractors much of the overall responsibility for a given major system. That responsibility often includes design and R&D in addition to the fabrication of the system in question. Each contract is managed through one of three national laboratories: PPPL, LLNL, and ORNL. Separate contracts for system integration and construction management round out the industry involvement in the project. This integrated, major responsibility attracts high-level corporate attention within each company, which are major corporations with long-standing interest in fusion. Through the contracts already established on the TPX project, a new standard for industry involvement in fusion has been set, and these industries will be well prepared for future fusion projects.

Thomassen, K.; Lang, D. [Lawrence Livermore National Lab., CA (United States); Schmidt, J.; Burger, A. [and others

1995-06-01

170

A learning pathway in high-school level quantum atomic physics  

Microsoft Academic Search

In this paper, one student's learning process in a course on quantum atomic physics in grade 13 of a German gymnasium (secondary school) is described. The course lasted 16 weeks for a total of approximately 80 lessons. The aim of the present study is to elaborate the student's cognitive system for atomic physics as a hypothetical pragmatic model to describe,

Juergen Petri; Hans Niedderer

1988-01-01

171

The interplay of nuclear and atomic physics in the synthesis of the elements  

SciTech Connect

In many astronomical environments, physical conditions are so extreme that matter is almost completely ionized. The absence of bound atomic electrons can dramatically alter the decay rates of a number of radioactive nuclei. Several examples of this interplay of nuclear and atomic physics relevant to the synthesis of the chemical elements are described. 16 refs., 4 figs.

Norman, E.B.

1989-03-01

172

Atomic collision and spectroscopy experiments with ultra-low-energy antiprotons  

Microsoft Academic Search

Antiproton, the antiparticle of proton, is a unique projectile in the study of atomic collision physics, which can be treated theoretically either as a 'negative proton' or a 'heavy electron'. Atomic capture of an antiproton will result in formation of a highly excited exotic atom. Antiprotonic helium atom has been studied intensively by means of precision laser spectroscopy, which has

Hiroyuki A. Torii; Yugo Nagata; Hiroshi Toyoda; Hiroshi Imao; Naofumi Kuroda; Victor L. Varentsov; Yasunori Yamazaki

2009-01-01

173

ATOMIC AND MOLECULAR PHYSICS: Modelling of a DNA packaging motor  

NASA Astrophysics Data System (ADS)

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.

Qian, Jun; Xie, Ping; Xue, Xiao-Guang; Wang, Peng-Ye

2009-11-01

174

Friction at Atomic-Scale Surface Steps: Experiment and Theory  

NASA Astrophysics Data System (ADS)

Experiments performed by friction force microscopy at atomic-scale surface steps on graphite, MoS2, and NaCl in ambient conditions are presented. Both step-down and step-up scans exhibit higher frictional forces at the edge, but distinguish in their load dependence: While the additional frictional force due to the step edge increases linearly with load if the tip has to jump a step up, it remains constant for downward jumps. This phenomenon represents a universal effect that can be explained in terms of a modified Prandtl-Tomlinson model featuring a Schwoebel-Ehrlich barrier at steps.

Hölscher, Hendrik; Ebeling, Daniel; Schwarz, Udo D.

2008-12-01

175

FROM THE HISTORY OF PHYSICS: The Schrödinger atom  

NASA Astrophysics Data System (ADS)

Aspects of an electrodynamical interpretation of the wave function suggested by Schrödinger are described. According to this conception, electron charge is continuously distributed throughout the interior of the atomic system. A proof is given that classical electrodynamics holds within an atom. The Schrödinger atom is shown to be the only model in which electrons do not lose their energy through emission when they move around the nucleus. The value of the self-field of the distributed electron charge is estimated. Practical applications of this concept are noted, including a new trend in quantum electrodynamics. Experimental and theoretical confirmation of the model of an atom with continuously distributed charge is presented.

Vlasov, A. D.

1993-02-01

176

Fisher-like atomic divergences: Mathematical grounds and physical applications  

NASA Astrophysics Data System (ADS)

Two different local divergence measures, the Fisher (FD) and the Jensen-Fisher (JFD) ones, are compared in this work by applying them to atomic one-particle densities in position and momentum spaces. They are defined in terms of the absolute and the relative Fisher information functionals. The analysis here afforded includes not only neutral atoms, but also singly-charged cations. The results are interpreted and justified according to (i) shell-filling patterns, (ii) short- and long-range behaviors of the atomic densities, and (iii) the value of the atomic ionization potential. The strengths of the FD measure, as compared to the JFD one, are emphasized.

Martín, A. L.; Angulo, J. C.; Antolín, J.

2013-11-01

177

Friendship, physicality, and physical education: an exploration of the social and embodied dynamics of girls’ physical education experiences  

Microsoft Academic Search

Physical education represents a dynamic social space where students experience and interpret physicality in a context that accentuates peer relationships and privileges particular forms of embodiment. This article focuses on girls’ understandings of physicality with respect to the organisation of physical education and more informal social networks. Research exploring the connections between the body, capital, physical activity, and femininity and

Laura Hills

2007-01-01

178

An ultra-low-power physics package for a chip-scale atomic clock  

Microsoft Academic Search

We report the design and measured thermal and mechanical performance of an ultra-low-power physics package for a chip-scale atomic clock (CSAC). This physics package enables communications and navigation systems that require a compact, low-power atomic frequency standard. The physics package includes a unique combination of thermal isolation, mechanical stability and robustness, and small package volume. We have demonstrated temperature control

Mark J. Mescher; R. Lutwak; Mathew Varghese

2005-01-01

179

Fermion molecular dynamics in atomic, molecular, and optical physics  

NASA Astrophysics Data System (ADS)

Classical dynamics, often called 'molecular dynamics' when applied to atoms and molecules, is much easier than solving the many-body Schrodinger equation for a number of reasons. In particular, correlation and rearrangement are simple in classical dynamics. Fermion molecular dynamics (FMD) is a quasi-classical method for treating quantum-mechanical systems using classical equations of motion with momentum-dependent model potentials added to the usual Hamiltonian. These model potentials constrain the motion to satisfy the Heisenberg uncertainty and the Pauli exclusion principles. We discuss the foundations of the FMD model and its applications to atomic and molecular structure, ion-atom collisions, stopping powers, formation of antiprotonic atoms, and multiple ionization of atoms in strong laser fields.

Wilets, Lawrence; Cohen, James S.

1998-03-01

180

Physics design options for compact ignition experiments  

SciTech Connect

This paper considers the following topics: (1) physics assessments-design and engineering impact, (2) zero-dimensional confinement studies relating to physics requirements and options for ignited plasmas, classes of devices with equivalent performance, and sensitivity to variations in confinement models, and (3) one and one-half dimensional confinement studies relating to dynamic simulations, critical physics issues, startup analyses, and volt-second consumption. (MOW)

Uckan, N.A.

1985-01-01

181

Introducing Fundamental Physical Experiments to Students.  

ERIC Educational Resources Information Center

|If students are restricted to making educational experiments only, they might acquire incorrect ideas concerning the nature and role of the experimental method because the educational experiment differs greatly from the scientific experiment by its tasks, complexity, number and variability of experiments and devices used, measurements, and…

Golin, Genrikh

2002-01-01

182

Theoretical atomic physics for fusion. 1995 annual report  

SciTech Connect

The understanding of electron-ion collision processes in plasmas remains a key factor in the ultimate development of nuclear fusion as a viable energy source for the nation. The 1993--1995 research proposal delineated several areas of research in electron-ion scattering theory. In this report the author summarizes his efforts in 1995. The main areas of research are: (1) electron-impact excitation of atomic ions; (2) electron-impact ionization of atomic ions; and (3) electron-impact recombination of atomic ions.

Pindzola, M.S.

1995-12-31

183

Spin injection into semiconductors, physics and experiments  

Microsoft Academic Search

In this paper we review and extend our modelling of the physics governing electrical spin injection into non-magnetic semiconductors. A critical evaluation is given of several approaches to circumvent the impedance mismatch that prohibits spin injection in the diffusive transport regime, i.e. ballistic transport, the use of tunnel barriers and the physics of a Schottky contact. We conclude by discussing

G. Schmidt; L. W. Molenkamp

2002-01-01

184

Two Physical Phenomena in One Experiment  

Microsoft Academic Search

In the physics laboratory, apparatus is normally used to illustrate a single theory or physical law. The apparatus used to study the principle of linear thermal expansion of solids, such as that manufactured by PASCO scientific,1 provides a bonus. In addition to using this apparatus for its original purpose, it can also be used to illustrate Newton's law of cooling

José Naranjo Torres

2006-01-01

185

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

ERIC Educational Resources Information Center

|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…

Unlu, Pervin

2010-01-01

186

Distributed atomic physics database and modeling system for plasma spectroscopy.  

National Technical Information Service (NTIS)

We are undertaking to develop a set of computational capabilities which will facilitate the access, manipulation, and understanding of atomic data in calculations of x-ray spectral modeling. In this present limited description we will emphasize the object...

J. K. Nash D. Liedahl M. H. Chen C. A. Iglesias R. W. Lee

1995-01-01

187

Quantum Dots: An Experiment for Physical or Materials Chemistry  

ERIC Educational Resources Information Center

|An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.|

Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.

2005-01-01

188

ATOMIC AND MOLECULAR PHYSICS: Kinetic theory of (2 + 4)-level atom in ?+ - ?- laser fields  

NASA Astrophysics Data System (ADS)

The kinetic theory of (2 + 4)-level atoms in ? + - ?- laser fields is presented. We systemically discuss friction coefficient, momentum diffusion tensor and atomic temperature based on the Fokker-Planck equation. This cooling system is much like that of a (1 + 3)-level atom, and the temperature is still limited to the Doppler temperature. Since this cooling system has not been investigated before, this work may be regarded as a necessary complement to the laser cooling theory.

Yu, Chuang; Yu, De-Shui; Chen, Jing-Biao

2009-08-01

189

Quantum metrology -- optical atomic clocks and many-body physics.  

NASA Astrophysics Data System (ADS)

Optical clocks based on atoms confined in optical lattices provide a unique opportunity for precise study and measurement of quantum many- body systems. The state-of-the-art optical lattice clock has reached an overall fractional frequency uncertainty of 1 x 10-16 [1]. One dominant contribution to this uncertainty is clock frequency shift arising from atomic collisions. Collisions between initially identical fermionic Sr atoms can occur when they are subject to slightly inhomogeneous optical excitations during the clock operation [2]. We have recently implemented a seemingly paradoxical solution to the collisionshift problem: with a strong atomic confinement in one-dimensional tube-shaped optical traps, we dramatically increase the atomic interactions. Instead of a naively expected increase of collisional frequency shifts, these shifts are increasingly suppressed [3]. The large atomic interaction strength creates an effective energy gap in the system such that inhomogeneous excitations can no longer drive fermions into a pseudo-spin antisymmetric state, and hence their collisions and the corresponding frequency shifts are suppressed. We demonstrate the effectiveness of this approach by reducing the density-related frequency shift to the level of 10-17, representing more than a factor of ten reduction from the previous record [1, 2]. In addition, we have observed well-resolved interaction sidebands separated from the main peak of the clock transition, giving a direct evidence for the removal of the interaction energy from the clock carrier transition. Control of atomic interactions at the level of 1 x 10-17 is a testimony to our understanding of a quantum many-body system and it removes an important obstacle for building an optical atomic clock based on such systems with high accuracy. [4pt] [1] A. D. Ludlow et al., Science 319, 1805 (2008). [0pt] [2] G. K. Campbell et al., Science 324, 360 (2009). [0pt] [3] M. D. Swallows et al., Science 331, 1043 (2011).

Ye, Jun

2011-10-01

190

Coherent backscattering of light by cold atoms: Theory meets experiment  

Microsoft Academic Search

Coherent backscattering (CBS) of quasi-resonant light by cold atoms presents some specific features due to the internal structure of the atomic scatterers. We present the first quantitative comparison between the experimentally observed CBS cones and Monte Carlo calculations which take into account the shape of the atomic cloud as well as the internal atomic structure.

G. Labeyrie; D. Delande; C. A. Müller; C. Miniatura; R. Kaiser

2003-01-01

191

Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions  

SciTech Connect

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.

Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.

1986-01-01

192

Atomic Collision Experiments with Ultra-Low-Energy Antiprotons  

SciTech Connect

We have developed techniques to decelerate, cool and confine antiprotons in vacuo with an electromagnetic trap, for production of a Monoenergetic Ultra-Slow Antiproton Source for High-precision Investigation (MUSASHI) over the last several years. The ultra-slow antiproton beam which can now be extracted stably has opened up the possibility to study ionization and atomic capture processes between an antiproton and an atom at an unprecedented low energy under the single-collision condition for the first time. The collision energy can be tuned from 10 eV to 1 keV either by varying the beam transport energy or by biasing the voltages at the collision region.Since the number of available antiprotons is very much limited, the reaction probability must be maximized in order to make best use of them. We have prepared a powerful supersonic helium gas jet with a density of 3x10{sup 12} atoms/cm{sup 3} to be crossed with the antiproton beam. For rigorous identification of particles (e{sup -}, p-bar and (p-barA{sup +}){sup 0}) needed for reduction of huge background signals, we developed a detection system with two microchannel plates each with a delay-line two-dimensional position sensitive detector, and a box of scintillator plates. A set of electrodes and coils were placed near the collision point to guide electromagnetically the electrons perpendicular to the antiproton beam. The reaction events will be recognized by an electron signal followed by an antiproton annihilation with an appropriate time of flight. Our design and strategy of the experiment are discussed.

Torii, Hiroyuki A.; Kuroda, Naofumi; Ogata, Koremitsu; Toyoda, Hiroshi; Shimoyama, Takuya; Enomoto, Yoshinori [Institute of Physics, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nagata, Yugo; Yamazaki, Yasunori [Institute of Physics, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Atomic Lab., RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Imao, Hiroshi; Shibata, Masahiro; Kanai, Yasuyuki; Mohri, Akihiro [Atomic Lab., RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Varentsov, Victor L. [V. G. Khlopin Radium Institute, 2-nd Murinsky Ave. 28, 194021 St. Petersburg (Russian Federation); Higaki, Hiroyuki [Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8530 (Japan)

2008-08-08

193

Thermal physics in the introductory physics course: Why and how to teach it from a unified atomic perspective  

NSDL National Science Digital Library

Heat and thermodynamics are traditionally taught in the introductory physics course from a predominantly macroscopic point of view. However, it is advantageous to adopt a more modern approach that systematically builds on students' knowledge of the atomic structure of matter and of elementary mechanics. By focusing on the essential physics without requiring more than elementary classical mechanics, this approach can be made sufficiently simple to be readily teachable during five or six weeks of an ordinary calculus-based introductory physics course. This approach can be highly unified, using atomic considerations to infer the properties of macroscopic systems while also enabling thermodynamic analyses independent of specific atomic models. Furthermore, this integrated point of view provides a deeper physical understanding of basic concepts (such as internal energy, heat, entropy, and absolute temperature) and of important phenomena (such as equilibrium, fluctuations, and irreversibility).

Reif, Frederick

2005-11-23

194

The Physics of Bird Flight: An Experiment  

ERIC Educational Resources Information Center

|This article describes an experiment that measures the forces acting on a flying bird during takeoff. The experiment uses a minimum of equipment and only an elementary knowledge of kinematics and Newton's second law. The experiment involves first digitally videotaping a bird during takeoff, analyzing the video to determine the bird's position as…

Mihail, Michael D.; George, Thomas F.; Feldman, Bernard J.

2008-01-01

195

The Physics of Bird Flight: An Experiment  

ERIC Educational Resources Information Center

This article describes an experiment that measures the forces acting on a flying bird during takeoff. The experiment uses a minimum of equipment and only an elementary knowledge of kinematics and Newton's second law. The experiment involves first digitally videotaping a bird during takeoff, analyzing the video to determine the bird's position as a…

Mihail, Michael D.; George, Thomas F.; Feldman, Bernard J.

2008-01-01

196

Kinematically Complete Experiments on Single Ionization in Simple Atomic Systems  

NASA Astrophysics Data System (ADS)

Fully differential studies on atomic reaction dynamics are crucially important to advance our understanding of the few-body problem. In the case of electron impact, fully differential cross sections for single ionization have been measured for several decades. The vast majority of these studies were restricted to electrons ejected into specific planes. More importantly, for ion impact such experiments are much more challenging and fully differential cross sections (FDCS) became only available a few years ago. However, at the same time these measurements for ion impact also yielded the first complete three-dimensional images of the FDCS. The sobering conclusion of these studies was that our understanding of ionization processes in atomic collisions is much less complete than assumed previously. In this talk new unexpected results on three-dimensional FDCS will be presented for kinematic regimes for which so far no experimental FDCS have been obtained yet. These include collisions involving highly relativistic and highly charged ions as well as relatively slow p projectiles. In collaboration with Ahmad Hasan, Natasha Maydanyuk, Matt Foster, Brian Tooke and Don Madison, University of Missouri-Rolla.

Schulz, Michael

2006-10-01

197

Physics experiments with Nintendo Wii controllers  

NASA Astrophysics Data System (ADS)

This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from a spring undergoing simple harmonic motion, a pair of controllers mounted on colliding gliders on a linear air track, and a person jumping from a balance board.

Wheeler, Martyn D.

2011-01-01

198

Two Physical Phenomena in One Experiment  

NASA Astrophysics Data System (ADS)

In the physics laboratory, apparatus is normally used to illustrate a single theory or physical law. The apparatus used to study the principle of linear thermal expansion of solids, such as that manufactured by PASCO scientific,1 provides a bonus. In addition to using this apparatus for its original purpose, it can also be used to illustrate Newton's law of cooling in the course of a single laboratory period.

Torres, José Naranjo

2006-10-01

199

Youth with Visual Impairments: Experiences in General Physical Education  

ERIC Educational Resources Information Center

|The rapid increase in the number of students with visual impairments currently being educated in inclusive general physical education makes it important that physical education instructors know how best to serve them. Assessment of the experiences of students with visual impairments during general physical education classes, knowledge of…

Lieberman, Lauren J.; Robinson, Barbara L.; Rollheiser, Heidi

2006-01-01

200

An experiment on a physical pendulum and Steiner's theorem  

NASA Astrophysics Data System (ADS)

Introductory physics laboratory curricula usually include experiments on the moment of inertia, the centre of gravity, the harmonic motion of a physical pendulum, and Steiner's theorem. We present a simple experiment using very low cost equipment for investigating these subjects in the general case of an asymmetrical test body.

Russeva, G. B.; Tsutsumanova, G. G.; Russev, S. C.

2010-01-01

201

Impact Crater Experiments for Introductory Physics and Astronomy Laboratories  

ERIC Educational Resources Information Center

|Activity-based collisional analysis is developed for introductory physics and astronomy laboratory experiments. Crushable floral foam is used to investigate the physics of projectiles undergoing completely inelastic collisions with a low-density solid forming impact craters. Simple drop experiments enable determination of the average…

Claycomb, J. R.

2009-01-01

202

Friendship, Physicality, and Physical Education: An Exploration of the Social and Embodied Dynamics of Girls' Physical Education Experiences  

ERIC Educational Resources Information Center

|Physical education represents a dynamic social space where students experience and interpret physicality in a context that accentuates peer relationships and privileges particular forms of embodiment. This article focuses on girls' understandings of physicality with respect to the organisation of physical education and more informal social…

Hills, Laura

2007-01-01

203

Summary of informal workshop on state of ion beam facilities for atomic physics research  

SciTech Connect

The present state of ion beam facilities for atomic physics research in the United States is assessed by means of a questionnaire and informal workshop. Recommendations for future facilities are given. 3 refs.

Jones, K.W.; Cocke, C.L.; Datz, S.; Kostroun, V.

1984-11-13

204

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

NASA Astrophysics Data System (ADS)

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 bound-bound and bound-free radiative transitions. Chapter 4 concentrates on the formulation of basic theoretical methods and physical approaches to collisions involving R. atoms. Chapters 5 to 8 contain a systematic description of major directions and modern techniques in the collision theory of R. atoms and ions with atoms, molecules, electrons, and ions. Finally, Chapter 9 deals with the spectral-line broadening and shift of R. atomic series induced by collisions with neutral and charged particles. A subject index of four pages and 250 references are given. This monograph will be a basic tool and reference for all scientists working in the fields of plasma physics, spectroscopy, physics of electronic and atomic collisions, as well as astrophysics, radio astronomy, and space physics.

Mewe, R.; Mewe, R.

1999-07-01

205

Petimo: Sharing Experiences through Physically Extended Social Networking  

Microsoft Academic Search

\\u000a This paper presents an experience-sharing platform, Petimo, which consists of two modules, Petimo-World and Petimo-Robot.\\u000a This system extends the traditional social networking concept into the physical world by incorporating a child friendly soft\\u000a robotic toy for easy and safe social experience. It adds a new physical dimension to social computing and provides extra safety\\u000a in making friends by physically touching

Nimesha Ranasinghe; Owen Fernando; Adrian Cheok

206

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

SciTech Connect

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.

Todd Ditmire

2004-10-21

207

Learning Pathways in High-School Level Quantum Atomic Physics.  

ERIC Educational Resources Information Center

|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…

Niedderer, Hans; Petri, Juergen

208

Current experiments in elementary particle physics. Revision 1-85  

SciTech Connect

This report contains summaries of 551 approved experiments in elementary particle physics (experiments that finished taking data before 1 January 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Properties of the fixed-target beams at most of the laboratories are summarized. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Oyanagi, Y.; Dodder, D.C.; Grudtsin, S.N.; Ryabov, Yu.G.; Frosch, R.

1985-01-01

209

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

SciTech Connect

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.

Schuch, R.

1986-11-01

210

The physical structure of atoms: a new model  

Microsoft Academic Search

Purpose – The purpose of this paper is to establish a systemic yoyo model-based explanation for the internal structure of atoms, which is totally different of the conventional ones. Design\\/methodology\\/approach – The spin fields of systemic yoyos are used to explain the interactions between electric and magnetic fields and between elementary particles. Findings – The concepts of potential pits (traps)

Yi Lin; Xiaoya He

2010-01-01

211

Are Atom-sized X-ray Experiments Possible?  

SciTech Connect

The success of advanced microbeam facilities at third generation synchrotron sources have inspired us to ask ultimate questions such as how small an x-ray beam diameter can be made. With the hope of more brilliant Energy Recovery Linac or X-ray Free Electron Laser sources due to arrive in the next decade, it appears possible to think of fluorescent x-ray experiments that can be performed on even a single impurity atom in a silicon wafer, for instance. Not all x-ray optical developers are yet convinced, however, so there is critical need to assess whether in principle this can really be done or not. We are optimistic that 1 nm diameter x-ray beams can be made of sufficient flux from future sources or even demonstration experiments at lower count rates from 3rd generation sources if it turns out to be worthwhile to actively develop optics and methods that vastly exceed the current x-ray microbeam capabilities.

Bilderback, Donald H. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States); Huang Rong [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

2004-05-12

212

TITAN'S EXPERIENCE IN PHYSICAL SEPARATION DEVICES  

Microsoft Academic Search

As a naphtha cracker, Titan is used to several types of separators especially in the quench and hot fractionation section. This paper will zoom into the separation process involving immiscible fluid phase with different densities for separation to occur. Three principles used to achieve physical separation of gas, liquids or solids are momentum, gravity settling, and coalescing. Seperators may employ

Lee Siang Hua; Titan Petrochemicals

213

ATOMIC AND MOLECULAR PHYSICS: Realization of Green MOT for Ytterbium Atoms  

NASA Astrophysics Data System (ADS)

We report the experimental realization of a magneto-optical trap (MOT) of 174Yb atoms operating on the 1So-3 P1 intercombination transition at 555.8 nm. The green MOT is loaded by a Zeeman-slowed atomic beam. In order to increase the capture velocity of the MOT, we use the trapping laser beams consisting of five discrete frequency components obtained by modulating the laser light through an electro-optic modulator. The trapped atomic number of the 174Yb isotope is about 6.2 × 105, and the temperature of the cold atomic cloud is estimated to be about 100 ?K. The success of the green MOT is an important step towards the goal of an ytterbium optical clock.

Zhao, Peng-Yii; Xiong, Zhuan-Xian; Long, Yun; He, Ling-Xiang; Lü, Bao-Long

2009-08-01

214

Effects of Solution Physical Properties on Copper and Chromium Signals in Flame Atomic Absorption Spectrometry  

NASA Astrophysics Data System (ADS)

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.

Rocha, Fàbio R. P.; Nòbrega, Joaquim A.

1996-10-01

215

Thought Experiments and Collaborative Learning in Physics.  

ERIC Educational Resources Information Center

|Describes a study that illustrates that collaborative-thought experiments are emergent phenomena triggered by events as a whole rather than being predesigned. Points out that participants gradually adopt shared graphical representations and meanings. Contains 28 references. (DDR)|

Reiner, Miriam

1998-01-01

216

Ground-based laboratory atomic oxygen calibration experiments  

NASA Astrophysics Data System (ADS)

Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth orbit (LEO) AO space environment, an environment which contributes significantly to the degradation of spacecraft materials. Three types of AO measuring device, referred to as 'silver film', 'bulk polymer mass loss' and 'polymer overlay' devices, were used in the experiments and were based on the following principles for detection of AO, respectively: (1) The electrical resistivity characteristics of oxidising, thin silver films. (2) The mass loss of bulk polymeric materials. (3) The combination of both the above phenomena. In calibrating the responses of these devices upon exposure to AO, it was necessary to improve an existing technique to establish reference measurements of AO fluences based on the mass loss of the polymeric material 'Kapton-H'. Experiments showed that the most significant disturbance factor affecting accurate measurements of mass loss was atmospheric humidity, which was found to be responsible for a disturbance of 0.012(±0.002)mg per percent change in atmospheric humidity level for the particular samples used in this research. Experiments also revealed a novel technique which indicated the relative stability of conditions within a simulated AO environment by the ratio of mass losses of a set of polymeric test samples, including polyethylene, polytetrafluoroethylene and Kapton-H, described as a 'signature analysis technique'. Interactions occurring between AO and a variety of polyethylene related polymeric materials were shown to be influenced by the methods used to manufacture and process the polymers. This influence has been related to changes in polymeric material density and crystallinity. In addition, the limitations in protecting a polymeric material from AO erosion by insertion of fluorine into the side-chain group chemistry has been indicated. Of most significance to the development of polymer overlay devices was the discovery that the overlay material AO erosion yield was dependent upon the rate at which the polymer overlay material was sputter deposited. These devices were also shown to detect AO fluences that were linearly dependent upon the initial thickness of the overlay material up to certain thicknesses, beyond which the effects of overlay porosity or fracturing weakened the linear relationship. A novel method for analysing silver film device electrical resistances under AO exposure has been developed from a combination of existing fundamental theories concerning the electrical resistivity phenomena in thin metallic films. Validation of this analysis method revealed that experimental silver film data were consistently in disagreement with the existing theories due to a factor influencing the conduction electron mean free path length in the silver films. Final validation of this analysis technique was performed by comparing results derived from the same set of experimental silver film device data using the new technique and an example of a previous technique. It was confirmed that the novel analysis technique produced far more consistent values for the oxidation yield of silver, 3/pm0.5×10-24cm3.atom-1, than the previously used technique, 6/pm3×10- 24cm3.atom-1. The novel analysis technique has been demonstrated to be theoretically more accurate for the analysis of silver film resistance data than any previously applied theories.

Matcham, Jeremy Stephen

1998-12-01

217

Plasma injection and atomic physics models for use in particle simulation codes  

SciTech Connect

Models of plasma injection (creation) and charged/neutral atomic physics which are suitable for incorporation into particle simulation codes are described. Both planar and distributed source injection models are considered. Results obtained from planar injection into a collisionless plasma-sheath region are presented. The atomic physics package simulates the charge exchange and impact ionization interactions which occur between charged particles and neutral atoms in a partially-ionized plasma. These models are applicable to a wide range of problems, from plasma processing of materials to transport in the edge region of a tokamak plasma. 18 refs., 6 figs.

Procassini, R.J. (Lawrence Livermore National Lab., CA (USA) California Univ., Berkeley, CA (USA). Electronics Research Lab.)

1991-06-12

218

Physics of the missing atoms: technetium and promethium  

SciTech Connect

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.

Aspden, H.

1987-05-01

219

Low-Energy Universality in Atomic and Nuclear Physics  

Microsoft Academic Search

An effective field theory developed for systems interacting through short-range interactions can be applied to systems of\\u000a cold atoms with a large scattering length and to nucleons at low energies. It is therefore the ideal tool to analyze the universal\\u000a properties associated with the Efimov effect in three- and four-body systems. In this progress report, we will discuss recent results

Lucas Platter

2009-01-01

220

Atomic and molecular physics in the gas phase.  

PubMed

The spatial and temporal distributions of energy deposition by high-linear-energy-transfer radiation play an important role in the subsequent chemical and biological processes leading to radiation damage. Because the spatial structures of energy deposition events are of the same dimensions as molecular structures in the mammalian cell, direct measurements of energy deposition distributions appropriate to radiation biology are infeasible. This circumstance has led to the development of models of energy transport based on a knowledge of atomic and molecular interactions that enable one to simulate energy transfer on an atomic scale. Such models require a detailed understanding of the interactions of ions and electrons with biologically relevant material. During the past 20 years, there has been a great deal of progress in our understanding of these interactions, much of it coming from studies in the gas phase. These studies provide information on the systematics of interaction cross sections, and lead to knowledge of the regions of energy deposition where molecular and phase effects are important-knowledge that guides development in appropriate theory. In this report, studies of the doubly differential cross sections, which are crucial to the development of stochastic energy deposition calculations and track structure simulation, are reviewed. We discuss areas of understanding and address directions for future work. Particular attention is given to experimental and theoretical findings that have changed the traditional view of secondary electron production for charged-particle interactions with atomic and molecular targets. PMID:1811483

Toburen, L H

1991-01-01

221

Determination of Spin-Lattice Relaxation of Time Using (Super 13)C NMR: An Undergraduate Physical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

An experiment designed for the physical chemistry laboratory where (super 13)C NMR is applied to determine the spin-lattice relaxation time for carbon atoms in n-hexanol is proposed. It is concluded that students learn the principles and concepts of NMR spectroscopy as well as dynamic NMR experiments.

Gasyna, Zbigniew L.; Jurkiewicz, Antoni

2004-01-01

222

ATOMIC AND MOLECULAR PHYSICS: Four-parameter analytical local model potential for atoms  

NASA Astrophysics Data System (ADS)

Analytical local model potential for modeling the interaction in an atom reduces the computational effort in electronic structure calculations significantly. A new four-parameter analytical local model potential is proposed for atoms Li through Lr, and the values of four parameters are shell-independent and obtained by fitting the results of Xa method. At the same time, the energy eigenvalues, the radial wave functions and the total energies of electrons are obtained by solving the radial Schrödinger equation with a new form of potential function by Numerov's numerical method. The results show that our new form of potential function is suitable for high, medium and low Z atoms. A comparison among the new potential function and other analytical potential functions shows the greater flexibility and greater accuracy of the present new potential function.

Yu, Fei; Sun, Jiu-Xun; Tian, Rong-Gang; Yang, Wei

2009-10-01

223

Solution Calorimetry Experiments for Physical Chemistry.  

ERIC Educational Resources Information Center

|Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)|

Raizen, Deborah A.; And Others

1988-01-01

224

Precision electroweak physics at future collider experiments  

SciTech Connect

We present an overview of the present status and prospects for progress in electroweak measurements at future collider experiments leading to precision tests of the Standard Model of Electroweak Interactions. Special attention is paid to the measurement of the {ital W} mass, the effective weak mixing angle, and the determination of the top quark mass. Their constraints on the Higgs boson mass are discussed.

Baur, U. [State Univ. of New York, Buffalo, NY (United States). Dept. of Physics; Demarteau, M. [Fermi National Accelerator Lab., Batavia, IL (United States)

1996-11-01

225

Using the Wiimote in Introductory Physics Experiments  

ERIC Educational Resources Information Center

|The Wii is a very popular gaming console. An important component of its appeal is the ease of use of its remote controller, popularly known as a Wiimote. This simple-looking but powerful device has a three-axis accelerometer and communicates with the console via Bluetooth protocol. We present two experiments that demonstrate the feasibility of…

Ochoa, Romulo; Rooney, Frank G.; Somers, William J.

2011-01-01

226

Condensed Matter Physics With Light And Atoms: Strongly Correlated Cold Fermions in Optical Lattices  

Microsoft Academic Search

Various topics at the interface between condensed matter physics and the physics of ultra-cold fermionic atoms in optical lattices are discussed. The lectures start with basic considerations on energy scales, and on the regimes in which a description by an effective Hubbard model is valid. Qualitative ideas about the Mott transition are then presented, both for bosons and fermions, as

Antoine Georges

2007-01-01

227

ATOMIC AND MOLECULAR PHYSICS: Lithium atom population transfer by population trapping in a chirped microwave pulse  

NASA Astrophysics Data System (ADS)

Using a time-dependent multilevel approach, we demonstrate that lithium atoms can be transferred to states of lower principle quantum number by exposing them to a frequency chirped microwave pulse. The population transfer from n = 79 to n = 70 states of lithium atoms with more than 80% efficiency is achieved by means of the sequential two-photon ?n = -1 transitions. It is shown that the coherent control of the population transfer can be accomplished by the optimization of the chirping parameters and microwave field strength. The calculation results agree well with the experimental ones and novel explanations have been given to understand the experimental results.

Jia, Guang-Rui; Zhang, Xian-Zhou; Ren, Zhen-Zhong; Wu, Su-Ling

2009-12-01

228

New experiments on few-electron very heavy atoms  

SciTech Connect

New experiments, to test quantum electrodynamics (QED) in strong Coulomb fields and to study atomic collisions at ultrarelativistic energies, are proposed. A 0.1% measurement of the 2/sup 2/P/sub 1/2/-2/sup 2/S/sub 1/2/ splitting in lithium like uranium (Z=92) and the 2/sup 3/P/sub 0/ - 2/sup 3/S/sub 1/ splitting in heliumlike uranium is proposed as a sub 1% test of the Lamb shift in a strong Coulomb field. Measurements of the hyperfine splitting of hydrogenlike thallium (Z=81) and the g/sub j/ factor of the ground state of hydrogenlike uranium are propsed as a test of the QED contribution to the magnetic moment of an electron bound in a strong Coulomb field. Measurements of capture cross sections for ultra relativistic very heavy nuclei are proposed to look for the capture of electrons from pair production. 40 refs., 7 figs., 2 tabs.

Gould, H.

1985-07-01

229

Project Physics Handbook 5, Models of the Atom.  

ERIC Educational Resources Information Center

|Five experiments and 19 activities are presented in this Unit 5 handbook. The experiments are related to electrolysis, charge-to-mass ratio, elementary charge determination, photoelectric effects, and spectroscopic analyses. The activities are concerned with Dalton's theory, water electrolysis, periodic tables, single-electron plating, cloud…

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

230

Atomic Data Needs for Laboratory and Astrophysical Plasma Physics Research  

SciTech Connect

This paper presents a brief description of collisional-radiative model benchmarking experiments performed on tokamak plasmas. The relevance of such experiments for astrophysical research is exemplified with the case of M-shel iron emission in the soft X-ray range.

Finkenthal, Michael [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218 (United States)

2007-04-06

231

Low-Energy Universality in Atomic and Nuclear Physics  

NASA Astrophysics Data System (ADS)

An effective field theory developed for systems interacting through short-range interactions can be applied to systems of cold atoms with a large scattering length and to nucleons at low energies. It is therefore the ideal tool to analyze the universal properties associated with the Efimov effect in three- and four-body systems. In this progress report, we will discuss recent results obtained within this framework and report on progress regarding the inclusion of higher order corrections associated with the finite range of the underlying interaction.

Platter, Lucas

2009-09-01

232

Fluctuations and jump dynamics in atomic friction experiments  

NASA Astrophysics Data System (ADS)

Atomic stick-slip processes have been studied in detail by means of friction force microscopy with high spatial and temporal resolution. The influence of the tip-sample contact on the thermal fluctuations of the force sensor and on the dynamics of the stick-slip process are characterized. Results are compared with simulations based on an extended Tomlinson model including thermal fluctuations. A correlation between the duration of the atomic slip event and the atomic structure of the contact is established.

Maier, S.; Sang, Yi; Filleter, T.; Grant, M.; Bennewitz, R.; Gnecco, E.; Meyer, E.

2005-12-01

233

Atomic physics at the future facility for antiproton and ion research: a status report  

NASA Astrophysics Data System (ADS)

The new international accelerator Facility for Antiproton and Ion Research (FAIR) which is currently under construction in Darmstadt has key features that offer a wide range of exciting new opportunities in the field of atomic physics and related fields. The facility will provide highest intensities of relativistic beams of both stable and unstable heavy nuclei, in combination with the strong electromagnetic fields generated by high-power lasers, thus allowing to widen atomic physics research into completely new domains. In the current contribution, a short overview of the SPARC (Stored Particle Atomic physics Research Collaboration) research programme at the FAIR facility is given. Furthermore, we present the current strategy for the realization of the envisioned SPARC physics programme at the modularized start version of the FAIR facility.

Gumberidze, A.; SPARC Collaboration

2013-09-01

234

Hyperthermal atomic oxygen source for near-space simulation experiments  

SciTech Connect

A hyperthermal atomic oxygen (AO) beam facility has been developed to investigate the collisions of high-velocity AO atoms with vapor-phase counterflow. Application of 4.5 kW, 2.4 GHz microwave power in the source chamber creates a continuous discharge in flowing O{sub 2} gas. The O{sub 2} feedstock is introduced into the source chamber in a vortex flow to constrain the plasma to the center region, with the chamber geometry promoting resonant excitation of the TM{sub 011} mode to localize the energy deposition in the vicinity of the aluminum nitride (AlN) expansion nozzle. The approximately 3500 K environment serves to dissociate the O{sub 2}, resulting in an effluent consisting of 40% AO by number density. Downstream of the nozzle, a silicon carbide (SiC) skimmer selects the center portion of the discharge effluent, prior to the expansion reaching the first shock front and rethermalizing, creating a beam with a derived 2.5 km s{sup -1} velocity. Differential pumping of the skimmer chamber, an optional intermediate chamber and reaction chamber maintains a reaction chamber pressure in the mid-10{sup -6} to mid-10{sup -5} Torr range. The beam has been characterized with regard to total AO beam flux, O{sub 2} dissociation fraction, and AO spatial profile using time-of-flight mass spectrometric and Kapton-H erosion measurements. A series of reactions AO+C{sub n}H{sub 2n} (n=2-4) has been studied under single-collision conditions using mass spectrometric product detection, and at higher background pressure detecting dispersed IR emissions from primary and secondary products using a step-scan Michelson interferometer. In a more recent AO crossed-beam experiment, number densities and predicted IR emission intensities have been modeled using the direct simulation Monte Carlo technique. The results have been used to guide the experimental conditions. IR emission intensity predictions are compared to detected signal levels to estimate absolute reaction cross sections.

Dodd, James A.; Baker, Paul M.; Hwang, Eunsook S.; Sporleder, David; Stearns, Jaime A. [Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, Massachusetts 01731 (United States); Chambreau, Steven D. [Propulsion Directorate, Air Force Research Laboratory, Edwards AFB, California 93524 (United States); Braunstein, Matthew; Conforti, Patrick F. [Spectral Sciences, Inc., 4 Fourth Ave., Burlington, Massachusetts 01803 (United States)

2009-09-15

235

Experiences developing ALEGRA: A C++ coupled physics framework.  

National Technical Information Service (NTIS)

ALEGRA is a coupled physics framework originally written to simulate inertial confinement fusion (ICF) experiments being conducted at the PBFA-II facility at Sandia National Laboratories. It has since grown into a large software development project suppor...

K. G. Budge J. S. Peery

1998-01-01

236

Physics Analysis of the FIRE Experiment  

SciTech Connect

An integrated model of a complete discharge in the FIRE experiment has been developed based on the TSC simulation code. The complete simulation model includes a choice of several models for core transport, combined with an edge pedestal model and the Porcelli sawtooth model. Burn control is provided by feedback on the auxiliary heating power. We find that with the GLF23 and MMM95 transport models, Q >10 operation should be possible for H-mode pedestal temperatures in the range of 4-5 keV.

S.C. Jardin; C.E. Kessel; D. Meade; J. Breslau; G. Fu; N. Gorelenkov; J. Manickam; W. Park; H. Strauss

2002-06-19

237

Synthesis and Physical Properties of Liquid Crystals: An Interdisciplinary Experiment  

ERIC Educational Resources Information Center

|A study involves multiple chemistry and physics concepts applied to a state of matter that has biological relevance. An experiment involving the synthesis and physical properties of liquid crystals illustrates the interdisciplinary nature of liquid crystal research and the practical devices derived from such research.|

Van Hecke, Gerald R.; Karukstis, Kerry K.; Hanhan Li; Hendargo, Hansford C.; Cosand, Andrew J.; Fox, Marja M.

2005-01-01

238

Listening to Young People with Physical Disabilities' Experiences of Education  

Microsoft Academic Search

There is a general acceptance that inclusion is morally and ethically the most appropriate form of education. However, more research needs to focus on how best to accommodate and support the educational needs of all students, including those with physical disabilities. Listening to young people with physical disabilities talk about their educational experiences is one way to do this. The

Michael Curtin; Gill Clarke

2005-01-01

239

Attosecond streaking experiments on atoms: quantum theory versus simple model  

Microsoft Academic Search

A new theoretical approach to the description of the attosecond streaking measurements of atomic photoionization is presented. It is a fully quantum mechanical description based on numerical solving of the time-dependent Schroedinger equation which includes the atomic field as well as the fields of the XUV and IR pulses. Also a simple semiempirical description based on sudden approximation is suggested

A. K. Kazansky; N. M. Kabachnik

2006-01-01

240

Polarization spectroscopy of rubidium atoms: Theory and experiment  

Microsoft Academic Search

We present a theoretical and experimental study of polarization spectroscopy of rubidium atoms. All of the populations of the magnetic sublevels were calculated from the rate equations and used in the calculation of the polarization spectroscopy spectra. Using this model, we could generate theoretical line shapes of the polarization spectra on the D2 transitions of rubidium atoms. The experimental results

Huy Diep Do; Geol Moon; Heung-Ryoul Noh

2008-01-01

241

Atomic physics with highly-charged heavy ions at the GSI future facility: The scientific program of the SPARC collaboration  

Microsoft Academic Search

In the current report a short overview about the envisioned program of the atomic physics research collaboration SPARC (Stored Particle Atomic Research Collaboration, at the new international accelerator Facility for Antiproton and Ion Research (FAIR) at GSI is given. In addition, a condensed description of the planned experimental areas devoted to atomic physics research at the new facility is presented.

Th. Stöhlker; T. Beier; H. F. Beyer; F. Bosch; A. Bräuning-Demian; A. Gumberidze; S. Hagmann; C. Kozhuharov; Th. Kühl; D. Liesen; R. Mann; P. H. Mokler; W. Quint; R. Schuch; A. Warczak

2005-01-01

242

Imaging of atomic orbitals with the Atomic Force Microscope — experiments and simulations  

Microsoft Academic Search

Atomic force microscopy (AFM) is a mechanical profiling technique that allows\\u000ato image surfaces with atomic resolution. Recent progress in reducing the noise\\u000aof this technique has led to a resolution level where previously undetectable\\u000asymmetries of the images of single atoms are observed. These symmetries are\\u000arelated to the nature of the interatomic forces. The Si(111)-(7x7) surface is\\u000astudied

F. J. Giessibl; H. Bielefeldt; S. Hembacher; J. Mannhart

2001-01-01

243

Divertor design for the Tokamak Physics Experiment  

NASA Astrophysics Data System (ADS)

In this paper we discuss the present divertor design for the planned TPX tokamak, which will explore the physics and technology of steady-state (1000s pulses) heat and particle removal in high confinement (2-4 x L-mode), high beta (beta(sub N) greater than or equal to 3) divertor plasmas sustained by non-induct ive current drive. The TPX device will operate in the double-null divertor configuration, with actively cooled graphite targets forming a deep (0.5 m) slot at the outer strike point. The peak heat flux on, the highly tilted (74 deg) from normal) re-entrant (to recycle ions back toward the separatrix) will be in the range of 4-6 MW/sq m with 18 MW of neutral beams and RF heating power. The combination of active pumping and gas puffing (deuterium plus impurities), along with higher heating power (45 MW maximum) will allow testing of radiative divertor concepts at ITER-like power densities.

Hill, D. N.; Braams, B.; Brooks, J. N.; Ruzic, D. N.; Ulrickson, M.; Werley, K. A.; Campbell, R.; Goldston, R.; Kaiser, T.; Nellson, G. H.

1994-05-01

244

Polymer physics experiments with single DNA molecules  

NASA Astrophysics Data System (ADS)

Bacteriophage DNA molecules were taken as a model flexible polymer chain for the experimental study of polymer dynamics at the single molecule level. Video fluorescence microscopy was used to directly observe the conformational dynamics of fluorescently labeled molecules, optical tweezers were used to manipulate individual molecules, and micro-fabricated flow cells were used to apply controlled hydrodynamic strain to molecules. These techniques constitute a powerful new experimental approach in the study of basic polymer physics questions. I have used these techniques to study the diffusion and relaxation of isolated and entangled polymer molecules and the hydrodynamic deformation of polymers in elongational and shear flows. These studies revealed a rich, and previously unobserved, ``molecular individualism'' in the dynamical behavior of single molecules. Individual measurements on ensembles of identical molecules allowed the average conformation to be determined as well as the underlying probability distributions for molecular conformation. Scaling laws, that predict the dependence of properties on chain length and concentration, were also tested. The basic assumptions of the reptation model were directly confirmed by visualizing the dynamics of entangled chains.

Smith, Douglas E.

1999-11-01

245

Bounds on oscillating physics from solar system experiments  

NASA Astrophysics Data System (ADS)

We show that the model based on oscillating atomic lines which has recently been proposed to explain the observed periodicity in the galaxy distribution in a pencil beam survey is in effect ruled out by the experiment of Braginskii and Panov.

Sudarsky, Daniel

1992-05-01

246

Physically Measuring Thickness of Thin Films via Atomic Force Microscopy  

NASA Astrophysics Data System (ADS)

In our research of thin films, we invest a great deal of time and energy in characterizing our films physical and optical properties. We have found that it is imperative to have the ability to determine, with confidence, the thickness of our films when we try to describe a materials optical performance, especially true for work in the extreme ultraviolet. Unfortunately, weve learned this is not as simple a task as it would seem. Methods that are optical in nature that determine how thick a film is are less effective for very thin films (typically our films are 25-150 A thick). We would much rather be able to use an AFM to physically measure a films thickness. After much trial and tribulation, we are happy to report the method we have developed. Our technique involves using a rigidly supported, stainless steel razor blade to mask the substrate during deposition, leaving a distinct, abrupt edge when removed. The device is named the Abruptor.

Acosta, Guillermo; Allred, D.; Davis, R.; Webb, Nick

2002-03-01

247

Determination of G with atom interferometry; status of the experiment MAGIA  

Microsoft Academic Search

The MAGIA experiment is designed to measure the Newtonian gravitational constant G using atom interferometry. A double differential measurement of the gravitational force produced by heavy source masses on two clouds of atoms allows the determination of G. We present the general idea and actual status of the experiment

T. Petelski; L. Cacciapuoti; M. Fattori; G. Lamporesi; M. Prevedelli; J. Stuhler; G. M. Tino

2004-01-01

248

Physics Lab Experiments and Correlated Computer Aids. Teacher Edition.  

ERIC Educational Resources Information Center

Forty-nine physics experiments are included in the teacher's edition of this laboratory manual. Suggestions are given in margins for preparing apparatus, organizing students, and anticipating difficulties likely to be encountered. Sample data, graphs, calculations, and sample answers to leading questions are also given for each experiment. It is…

Gottlieb, Herbert H.

249

Perceptions of Overweight Students Concerning Their Experiences in Physical Education  

ERIC Educational Resources Information Center

|The purpose of this investigation was to examine overweight students' perceptions of and experiences in physical education. Specifically, the applicability of learned helplessness as a framework to understand their experiences was explored. Participants were seven female and five male high school students whose body mass index was at or higher…

Trout, Josh; Graber, Kim C.

2009-01-01

250

Perceptions of Overweight Students Concerning Their Experiences in Physical Education  

ERIC Educational Resources Information Center

The purpose of this investigation was to examine overweight students' perceptions of and experiences in physical education. Specifically, the applicability of learned helplessness as a framework to understand their experiences was explored. Participants were seven female and five male high school students whose body mass index was at or higher…

Trout, Josh; Graber, Kim C.

2009-01-01

251

Physics Lab Experiments and Correlated Computer Aids. Teacher Edition.  

ERIC Educational Resources Information Center

|Forty-nine physics experiments are included in the teacher's edition of this laboratory manual. Suggestions are given in margins for preparing apparatus, organizing students, and anticipating difficulties likely to be encountered. Sample data, graphs, calculations, and sample answers to leading questions are also given for each experiment. It is…

Gottlieb, Herbert H.

252

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

NASA Astrophysics Data System (ADS)

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).

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

2011-12-01

253

From a quantum to a classical description of intense laser-atom physics with Bohmian trajectories  

NASA Astrophysics Data System (ADS)

In this paper, Bohmian mechanics is applied to intense laser-atom physics. The motion of an atomic electron in an intense laser field is obtained from the Bohm-Newton equation. We find that the quantum potential that dominates the quantum effect of a physical system becomes negligible as the electron is driven far from the parent ion by the intense laser field, i.e. the behavior of the electron smoothly tends towards classical soon after the electron is ionized. Our numerical calculations present direct positive evidence for semiclassical trajectory methods in intense laser-atom physics where the motion of the ionized electron is treated by classical mechanics, while quantum mechanics is needed before the ionization.

Lai, X. Y.; Cai, Qing-Yu; Zhan, M. S.

2009-11-01

254

Experiments with Ultracold Quantum-degenerate Fermionic Lithium Atoms.  

National Technical Information Service (NTIS)

Experimental methods of laser and evaporative cooling, used in the production of atomic Bose-Einstein condensates have recently been extended to realize quantum degeneracy in trapped Fermi gases. Fermi gases are a new rich system to explore the implicatio...

W. Ketterle

2003-01-01

255

Attosecond streaking experiments on atoms: quantum theory versus simple model  

Microsoft Academic Search

A new theoretical approach to the description of the attosecond streaking\\u000ameasurements of atomic photoionization is presented. It is a fully quantum\\u000amechanical description based on numerical solving of the time-dependent\\u000aSchroedinger equation which includes the atomic field as well as the fields of\\u000athe XUV and IR pulses. Also a simple semiempirical description based on sudden\\u000aapproximation is suggested

A. K. Kazansky; N. M. Kabachnik

2006-01-01

256

Output from an atom laser: theory vs. experiment  

Microsoft Academic Search

.   Atom lasers based on rf-outcoupling can be described by a set of coupled generalized Gross–Pitaevskii equations (GPE). We\\u000a compare the theoretical predictions obtained by numerically integrating the time-dependent GPE of an effective one-dimensional\\u000a model with recently measured experimental data for the F=2 and F=1 states of Rb-87. We conclude that the output of a rf atom-laser can be described

Jens Schneider; Axel Schenzle

1999-01-01

257

The PHOBOS experiment at RHIC - physics and capabilities.  

SciTech Connect

The PHOBOS experiment at RHIC is designed to study multiplicity distributions and fluctuations over all of 4{pi}, as well as particle spectra and correlations at mid rapidity, with a particular emphasis on physics at low p{sub T}. The experiment is relatively small and relies almost entirely on silicon pad detector technology. The flexibility of the design, the conservative nature of the technologies used, and the ability to take data at high rates place the experiment in a good position to search for exotic physics from heavy-ion collisions at the early stages of RHIC operations.

Back, B. B.

1998-11-17

258

Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions  

SciTech Connect

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.

Not Available

1987-01-01

259

The physics of asymmetric atomic collisions studied by the SCA model  

NASA Astrophysics Data System (ADS)

The semiclassical trajectory method for atomic processes induced by charged projectiles is reviewed. The perturbative SCA formalism is sketched with emphasis on the first-order time-dependent approach. Selected results from computations on asymmetric collision systems are presented. The kinematic scaling law for ionization and pair-production phenomena is treated and commented upon. Applications of this scaling law in high-energy atomic collision physics are discussed. Stress is put on its possible consequences for the interpretation of the anomalous positron production in very heavy ion-atom collisions.

Hansteen, Johannes M.

1990-09-01

260

ATOMIC AND MOLECULAR PHYSICS: Tunneling between double wells of atom in crossed electromagnetic fields  

NASA Astrophysics Data System (ADS)

The tunneling between double wells of atom in crossed electromagnetic fields is investigated by a one-dimensional Hamiltonian model. The crossed fields induced outer well is apart from the nuclear origin and it is very difficult to access by means of spectroscopy but it will be possible if there exists the tunneling of the electron between the outer well and the Coulomb potential predominated well at the nuclear origin. A one-dimensional quantum calculation with B-spline basis has been performed for hydrogen atom in crossed fields accessible in our laboratory, at B = 0.8 T and F = -220 V·cm-1. The calculation shows that the wavefunctions of some excited states close to the Stark saddle point in the outer well extend over to the Coulomb potential well, making it possible to penetrate the quantum information of the outer well. However, the tunneling rate is very small and the spectral measurement of the transitions from the ground state should be of a high resolution and high sensitivity.

Shen, Li; Wang, Lei; Yang, Hai-Feng; Liu, Xiao-Jun; Liu, Hong-Ping

2009-12-01

261

Long Pulse Fusion Physics Experiments without Superconducting Electromagnets  

SciTech Connect

Long-pulse fusion physics experiments can be performed economically via resistive electromagnets designed for thermally steady-state operation. Possible fusion experiments using resistive electromagnets include long-pulse ignition with deuterium-tritium fuel. Long-pulse resistive electromagnets are alternatives to today's delicate and costly superconductors. At any rate, superconducting technology is now evolving independent of fusion, so near-term superconducting experience may not ultimately be useful.

Woolley, R.D.

1998-08-19

262

Theoretical atomic collision physics. Final report, July 1, 1987-- June 30, 1995  

SciTech Connect

This is the final report of research activities supported by the most recent grant to the theoretical atomic collision physics program at Rice University. For this most recent 3-year grant, the focus has been the study of excitation and charge-transfer in atom-atom and ion-atom collisions. Emphasis has been placed on low-velocity collision processes involving initially excited atoms, including ``low Rydberg`` atoms. Two particular objectives of this research were to examine the dependence of state-changing collision cross sections and other observables on the orientation and alignment of the initial excited orbitals and to look for ``intracollisional interference`` effects, speculated to arise from spatially separated interactions during a collision involving a highly excited atom. A number of radiative and non-radiative charge transfer studies involving ground-state atoms and ions were continued from the previous grant period. Several unanticipated personnel changes prevented execution of some of the proposed research, including the studies of collisions involving negative ions and electron-attaching atoms and the development of new theoretical techniques for handling the ``strong coupling`` regime. These remain challenging and fundamentally important research topics. Research highlights briefly described in the report deal with: spherical and non-spherical low-Rydberg atom collisions; alignment effects in collisions of Na(3p) with He{sup +} ions; near-resonant electron capture at very low energies; ion-atom and ion-molecule collisions, including electron capture; and low- energy processes involving collisions of H{sup +} with He, Na, and K atoms. The report also lists publications since 1991 reporting on the grant work.

Walters, G.K.

1995-12-01

263

HISTRAP (Heavy Ion Storage Ring for Atomic Physics) prototype hardware studies  

SciTech Connect

HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs.

Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

1989-01-01

264

ATOMIC AND MOLECULAR PHYSICS: Ionization of atoms by chirped attosecond pulses  

NASA Astrophysics Data System (ADS)

We investigate the ionization dynamics of atoms by chirped attosecond pulses using the strong field approximation method. The pulse parameters are carefully chosen in the regime where the strong field approximation method is valid. We analyse the effects of the chirp of attosecond pulses on the energy distributions and the corresponding left-right asymmetry of the ionized electrons. For a single chirped attosecond pulse, the ionized electrons can be redistributed and the left-right asymmetry shows oscillations because of the introduction of the chirp. For time-delayed double attosecond pulses at different intensities with the weaker one chirped, exchanging the order of the two pulses shows a relative shift of the energy spectra, which can be explained by the different effective time delays of different frequency components because of the chirp.

Tan, Fang; Peng, Liang-You; Gong, Qi-Huang

2009-11-01

265

High-energy shadowing effect and its application to atomic and solid state physics  

Microsoft Academic Search

Ion-beam shadowing effects for projectiles in the MeV\\/u energy range have been studied with high-energy (keV) secondary electrons emitted from the surface of a target crystal. This article reviews and discusses applications of the high-energy shadowing effect to atomic and solid state physics, as well as physical and technical aspects of the electron spectroscopy under channeling incidence conditions.

Kudo Hiroshi; Shima Kunihiro; Ishihara Toyoyuki; Takeshita Hidefumi; Aoki Yasushi; Yamamoto Shunya; Naramoto Hiroshi

1994-01-01

266

Atomic Clocks on Earth and in Space for Tests of Fundamental Physics and Navigation  

NASA Astrophysics Data System (ADS)

I review the performance objectives for RACE, the Rubidium Atomic Clock Experiment that was to fly on the International Space Station. RACE's performance could, in addition to significantly advancing clock tests of general relativity and Lorentz invariance, enable precise interplanetary navigation. I will also describe a juggling clock experiment that can sensitively probe interatomic forces at Angstrom ranges.

Gibble, K.

2005-04-01

267

Ground-based laboratory atomic oxygen calibration experiments  

Microsoft Academic Search

Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth

Jeremy Stephen Matcham

1998-01-01

268

Effective Atomic Numbers for Fe Mn Alloy Using Transmission Experiment  

NASA Astrophysics Data System (ADS)

The effective atomic numbers (Zeff) and effective electron density (Ne) for Fe-Mn alloy with different Mn contents are calculated using the mass attenuation coefficients ?/? obtained via XCOM in the photon energy range of 1 keV-1 GeV. The results are compared with the values measured at the photon energy of 662, 1170 and 1332 keV.

Iskender, Akkurt

2007-10-01

269

Atomic actions -- molecular experience: theory of pervasive gaming  

Microsoft Academic Search

In this article we attempt to describe and analyze the formalisms of pervasive games and pervasive gaming (PG). As the title indicates, PG consists of atomic entities that nevertheless merge into a molecular structure that exhibits emergent features during the actual game-play. The article introduces four axes of PG (mobility, distribution, persistence, and transmediality). Further, it describes and analyses three

Bo Kampmann Walther

2005-01-01

270

Current experiments in particle physics - particle data group  

SciTech Connect

This report contains summaries of current and recent experiments in Particle Physics. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, Frascati, ITEP (Moscow), JINR (Dubna), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several proton decay and solar neutrino experiments. Excluded are experiments that finished taking data before 1991. Instructions are given for the World Wide Web (WWW) searching of the computer database (maintained under the SLAC-SPIRES system) that contains the summaries.

Galic, H. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Lehar, F. [Centre d`Etudes Nucleaires de Saclay, Gif-sur-Yvette (France); Kettle, P.R. [Paul Scherrer Institute, Villigen (Switzerland)] [and others

1996-09-01

271

A programmatic framework for the Tokamak Physics Experiment (TPX)  

SciTech Connect

Significant advances have been made in the confinement of reactor-grade plasmas, so that the authors are now preparing for experiments at the [open quotes]power breakeven[close quotes] level in the JET and TFTR experiments. In ITER the authors will extend the performance of tokamaks into the burning plasma regime, develop the technology of fusion reactors, and produce over a gigawatt of fusion power. Besides taking these crucial steps toward the technical feasibility of fusion, the authors must also take steps to ensure its economic acceptability. The broad requirements for economically attractive tokamak reactors based on physics advancements have been set forth in a number of studies. An advanced physics data base is emerging from a physics program of concept improvement using existing tokamaks around the world. This concept improvements program is emerging as the primary focus of the US domestic tokamak program, and a key element of that program is the proposed Tokamak Physics Experiment (TPX). With TPX the authors can develop the scientific data base for compact, continuously-operating fusion reactors, using advanced steady-state control techniques to improve plasma performance. The authors can develop operating techniques needed to ensure the success of ITER and provide first-time experience with several key fusion reactor technologies. This paper explains the relationships of TPX to the current US fusion physics program, to the ITER program, and to the development of an attractive tokamak demonstration plant for this next stage in the fusion program.

Thomassen, K.I. (Lawrence Livermore National Lab., CA (United States)); Goldston, R.J. (Princeton Plasma Physics Lab., NJ (United States)); Neilson, G.H. (ORNL, Oak Ridge, TN (United States))

1993-09-01

272

FROM THE HISTORY OF PHYSICS: The development of the first Soviet atomic bomb  

Microsoft Academic Search

In the late 1930s and early 1940s, two remarkable physical phenomena --- the fission of heavy nuclei and the chain fission reaction --- were discovered, implying that a new powerful source of energy (nuclear fission energy) might become a practical possibility for mankind. At that time, however, the political situation in the world made the development of the atomic bomb

German A. Goncharov; Lev D. Ryabev

2001-01-01

273

Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond  

Microsoft Academic Search

We review recent developments in the physics of ultracold atomic and molecular gases in optical lattices. Such systems are nearly perfect realisations of various kinds of Hubbard models, and as such may very well serve to mimic condensed matter phenomena. We show how these systems may be employed as quantum simulators to answer some challenging open questions of condensed matter,

Maciej Lewenstein; Anna Sanpera; Veronica Ahufinger; Bogdan Damski; Aditi Sen; Ujjwal Sen

2007-01-01

274

A novel room temperature electron beam ion trap for atomic physics and materials research  

Microsoft Academic Search

Highly charged ions are used in basic investigations to study problems in atomic and plasma physics. Further on, the application of highly charged ions in materials research and other fields as nanomechanics and information techniques grew significantly in the last years. In the present paper, we report on results derived with a warm electron beam ion trap (WEBIT) that works

V. P Ovsyannikov; G. Zschornack; F. Großmann; O. K Koulthachev; S. Landgraf; F. Ullmann; T. Werner

2000-01-01

275

Do General Physics Textbooks Discuss Scientists' Ideas about Atomic Structure? A Case in Korea  

ERIC Educational Resources Information Center

|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…

Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho

2013-01-01

276

Long-term stability of NIST chip-scale atomic clock physics packages  

Microsoft Academic Search

We discuss the long-term stability of the NIST chip-scale atomic clock (CSAC) physics packages. We identify the major factors that currently limit the frequency stability of our CSAC packages after 100 s. The requirements for the stability of the vapor cell and laser temperature, local magnetic field, and local oscillator output power are evaluated. Due to the small size of

S. Knappe; V. Gerginov; V. Shah; A. Brannon; L. Hollberg; J. Kitching

2007-01-01

277

Do General Physics Textbooks Discuss Scientists' Ideas about Atomic Structure? A Case in Korea  

ERIC Educational Resources Information Center

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…

Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho

2013-01-01

278

Atomic-Scale Investigation of Latent Fission Tracks in Fluorapatite: Physical Characteristics and Annealing Behavior  

Microsoft Academic Search

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

Tracy Anne Paul

1993-01-01

279

Annual Progress Report for 1982 of Theoretical Reactor Physics Section, Bhabha Atomic Research Centre, Bombay, India.  

National Technical Information Service (NTIS)

The progress of work done in the Theoretical Reactor Physics Section of the Bhabha Atomic Research Centre, Bombay, during the calendar year 1982 is reported in the form of write-ups and summaries. The main thrust of the work has been to master the neutron...

B. P. Rastogi V. Kumar

1983-01-01

280

Future high precision experiments and new physics beyond Standard Model  

SciTech Connect

High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

Luo, Mingxing

1993-04-01

281

Future high precision experiments and new physics beyond Standard Model  

SciTech Connect

High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

Luo, Mingxing.

1993-01-01

282

Compilation of current high-energy-physics experiments  

SciTech Connect

This is the third edition of a compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and ten participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Rutherford (RHEL), Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about January 1980, and (2) had not completed taking of data by 1 January 1976.

Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.

1980-04-01

283

ATOMIC AND MOLECULAR PHYSICS: Experimental study of highly excited even-parity bound states of the Sm atom  

NASA Astrophysics Data System (ADS)

In this work, a three-step autoionization detection method and direct photoionization detection method are employed to measure the highly excited even-parity states of the Sm atom in the energy region between 36360 cm-1 and 40800 cm-1. Comparisons between the results from the two detection techniques enable us to discriminate the Rydberg states from the valence states in the same energy region with the information of level energies, possible J values and their relative intensities. Furthermore, in the experiment two different excitation schemes are designed to obtain the spectra of highly excited even-parity states of the Sm atom. With a detailed analysis of the experimental data, this work not only confirms the results about many spectral data from the literature with different excitation schemes, but also reports new spectral data on 29 Rydberg states and 23 valence states.

Qin, Wen-Jie; Dai, Chang-Jian; Xiao, Ying; Zhao, Hong-Ying

2009-08-01

284

The application of atomic physics to the study of solar abundances and their variations  

NASA Astrophysics Data System (ADS)

The determination of elemental abundances in the solar atmosphere depends critically on the accuracy of the atomic physics assumed in the models. Uncertainties in the electron-ion excitation rates, ionization and recombination rates or other atomic processes can lead to variations in the derived relative abundance values. In this paper, the different methods used in the analyses of UV and X-ray spectra are explored. Particular attention is paid to the accuracy of the atomic parameters and the assumptions made in the atomic model. A summary is given of the most recent theoretical and laboratory work. Implications for analyses of existing solar datasets and proposed observations Solar Heliospheric Observatory (SOHO) are discussed.

Mason, H. E.

1995-07-01

285

When Physical Activity Participation Promotes Inactivity: Negative Experiences of Spanish Adolescents in Physical Education and Sport  

ERIC Educational Resources Information Center

This article analyses negative experiences in physical education and sport reported during qualitative interviews of a group of inactive adolescent Spanish boys and girls. The purpose of this analysis is twofold. First and most important, it seeks to give voice to these young people reporting negative experiences and connect them to contexts of…

Beltran-Carrillo, Vicente J.; Devis-Devis, Jose; Peiro-Velert, Carmen; Brown, David H. K.

2012-01-01

286

MIT Physics 8.02: Experiment - Electrostatic Force  

NSDL National Science Digital Library

This is an instructor's guide for an experiment to measure electrostatic force, using parallel plates made from two washers, insulating perf-board, and aluminum foil. Photos and detailed instructions are provided for experimental setup. SEE RELATED MATERIALS for a Java simulation by the same authors on the topic of capacitance. For an Excel spreadsheet developed specifically to accompany this experiment, see link below: MIT Physics 8.02 Open Courseware: Labs

2010-04-14

287

Physical disability and the experience of chronic pain  

Microsoft Academic Search

Dudgeon BJ, Gerrard BC, Jensen MP, Rhodes LA, Tyler EJ. Physical disability and the experience of chronic pain. Arch Phys Med Rehabil 2002;83:229-35. Objectives: To obtain an insider's view about disability-related pain to help rehabilitation clinicians understand the experience and to show how people with disability manage daily living and encounters with other people. Design: Qualitative methods by using open-ended

Brian J. Dudgeon; Beth C. Gerrard; Mark P. Jensen; Lorna A. Rhodes; Erica J. Tyler

2002-01-01

288

Modular safety interlock system for high energy physics experiments  

SciTech Connect

A frequent problem in electronics systems for high energy physics experiments is to provide protection for personnel and equipment. Interlock systems are typically designed as an afterthought and as a result, the working environment around complex experiments with many independent high voltages or hazardous gas subsystems, and many different kinds of people involved, can be particularly dangerous. A set of modular hardware has been designed which makes possible a standardized, intergrated, hierarchical system's approach and which can be easily tailored to custom requirements.

Kieffer, J.; Golceff, B.V.

1980-10-01

289

The Planeterrella, a pedagogic experiment in planetology and plasma physics  

Microsoft Academic Search

We present here a plasma physics experiment which makes it possible to simulate, in a naive yet useful way, the formation\\u000a of polar lights. It involves shooting electrons at a magnetized sphere placed in a vacuum chamber. This experiment, inspired\\u000a by K. Birkeland’s Terrella, built at the turn of 19th century, allows the visualization of very many geophysical and astrophysical

Jean Lilensten; Mathieu Barthélemy; Cyril Simon; Philippe Jeanjacquot; Guillaume Gronoff

2009-01-01

290

Microwave ionization of hydrogen atoms: Experiment vs classical dynamics  

SciTech Connect

Ionization of hydrogen atoms with principal quantum number n = 32, 40, and 51--74 by a 9.92-GHz electric field F(t)zF0 cos t was studied with a superimposed static electric field F-bar/sub s/ = 0,2,5,8 V/cm. The measured field strengths F0(10%) at which 10% of the atoms were ionized are in excellent agreement with classical calculations in both one and two spatial dimensions. Covering finer detail as well as gross structure of the n dependence of F0(10%), the agreement supports the application of classical dynamics to the analysis of this strongly perturbed quantum system.

van Leeuwen, K.A.H.; Oppen, G.V.; Renwick, S.; Bowlin, J.B.; Koch, P.M.; Jensen, R.V.; Rath, O.; Richards, D.; Leopold, J.G.

1985-11-18

291

Atomic bombs and the long-run effect on trust: Experiences in Hiroshima and Nagasaki  

Microsoft Academic Search

Hiroshima and Nagasaki in Japan are the only cities in the world that have experienced an atomic bomb attack. This paper explores how this devastating experience affected victims’ tendency to trust others. Individual-level data were used to examine the long-term influence of experiencing an atomic bomb on individuals’ trust. After controlling for individual characteristics, I obtained the following key findings.

Eiji Yamamura

2012-01-01

292

Experiments with Single Atoms in a Cavity: Entanglement, Schrodinger's Cats and Decoherence  

Microsoft Academic Search

We perform experiments with Rydberg atoms crossing one at a time a superconducting cavity containing a few microwave photons. The coupling between the atoms and the cavity field is either resonant or dispersive. In the resonant case, quantum Rabi oscillations induced by the vacuum or by a small coherent field are observed. These signals reveals in a striking way the

S. Haroche; M. Brune; J. M. Raimond

1997-01-01

293

The Hispanic Experience in Physical Education Programs and Departments  

ERIC Educational Resources Information Center

The purpose of this article is to discuss challenges and identify strategies to increase the representation of Hispanic faculty in the academy, particularly Physical Education (PE) programs and departments at doctorate-granting universities. Recommendations to increase the presence and improve the experiences of Hispanic faculty are provided.…

Hodge, Samuel R.; Cervantes, Carlos M.; Vigo-Valentin, Alexander N.; Canabal-Torres, Maria Y.; Ortiz-Castillo, Esther M.

2012-01-01

294

BEAM LINES FOR PHYSICAL EXPERIMENTS OF DC350 CYCLOTRON  

Microsoft Academic Search

The beam lines for physical experiments of DC-350 cyclotron are presented. The bending magnet with variable magnetic field up to 1.5 T gives possibility to transport ion beam to five experimental installations. The beam focusing in the beam lines is provided by set of quadrupole lenses. The beam diagnostics consists of the Faraday caps, luminophors, aperture diaphragms, wire scanners and

G. Gulbekyan; G. Ivanov; I. Kalagin; V. Kazacha; N. Kazarinov; M. Khabarov; V. Melnikov

295

A Physical Chemistry Experiment in Polymer Crystallization Kinetics  

ERIC Educational Resources Information Center

|A laboratory experiment currently used in an undergraduate physical chemistry lab to investigate the rates of crystallization of a polymer is described. Specifically, the radial growth rates of typical disc-shaped crystals, called spherulites, growing between microscope glass slides are measured and the data are treated according to polymer…

Singfield, Kathy L.; Chisholm, Roderick A.; King, Thomas L.

2012-01-01

296

Experimenting in a Constructivist High School Physics Laboratory  

NSDL National Science Digital Library

Presents a study involving students (n=46) enrolled in an introductory physics course designed to describe and understand students' experimenting and problem-solving strategies in a constructivist learning environment. Concludes that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and can develop complex problem-solving skills.

Roth, Wolff-Michael

2006-10-09

297

The ALICE experiment at the LHC First Physics Results  

SciTech Connect

ALICE is one of the experiments at the LHC. The excellent performance of the detector has been demonstrated with the measurement and analysis of the first proton-proton collisions provided by the LHC on November 2009. We review the first physics results and the general status of the project. We also review the activities of the Mexican group participating in ALICE project.

Herrera Corral, Gerardo [CERN, CH-1211, Geneva 23 (Switzerland)

2010-08-04

298

Skylab Experiments, Volume I, Physical Science, Solar Astronomy.  

ERIC Educational Resources Information Center

Up-to-date knowledge about Skylab experiments is presented for the purpose of informing high school teachers about scientific research performed in orbit and enabling them to broaden their scope of material selection. The first volume is concerned with the solar astronomy program. The related fields are physics, electronics, biology, chemistry,…

National Aeronautics and Space Administration, Washington, DC.

299

Skylab Experiments, Volume I, Physical Science, Solar Astronomy.  

ERIC Educational Resources Information Center

|Up-to-date knowledge about Skylab experiments is presented for the purpose of informing high school teachers about scientific research performed in orbit and enabling them to broaden their scope of material selection. The first volume is concerned with the solar astronomy program. The related fields are physics, electronics, biology, chemistry,…

National Aeronautics and Space Administration, Washington, DC.

300

Long pulse neutral beam system for the Tokamak Physics Experiment  

Microsoft Academic Search

The Tokamak Physics Experiment (TPX) is planned as a long-pulse or steady-state machine to serve as a successor to the Tokamak Fusion Test Reactor (TFTR). The neutral beam component of the heating and current drive systems will be provided by a TFTR beamline modified to allow operation for pulse lengths of 1000 s. This paper presents a brief overview of

L. R. Grisham; O. N. Bowen; F. Dahlgren; J. W. Edwards; J. Kamperschroer; R. Newman; T. O'Connor; S. Ramakrishnan; G. Rossi; T. Stevenson; A. von Halle; K. E. Wright

1995-01-01

301

Radical Recombination Kinetics: An Experiment in Physical Organic Chemistry.  

ERIC Educational Resources Information Center

|Describes a student kinetic experiment involving second order kinetics as well as displaying photochromism using a wide variety of techniques from both physical and organic chemistry. Describes measurement of (1) the rate of the recombination reaction; (2) the extinction coefficient; and (3) the ESR spectrometer signal. (Author/JN)|

Pickering, Miles

1980-01-01

302

Enthalpy of Vaporization by Gas Chromatography: A Physical Chemistry Experiment  

ERIC Educational Resources Information Center

|An experiment is conducted to measure the enthalpy of vaporization of volatile compounds like methylene chloride, carbon tetrachloride, and others by using gas chromatography. This physical property was measured using a very tiny quantity of sample revealing that it is possible to measure the enthalpies of two or more compounds at the same time.|

Ellison, Herbert R.

2005-01-01

303

The Hispanic Experience in Physical Education Programs and Departments  

ERIC Educational Resources Information Center

|The purpose of this article is to discuss challenges and identify strategies to increase the representation of Hispanic faculty in the academy, particularly Physical Education (PE) programs and departments at doctorate-granting universities. Recommendations to increase the presence and improve the experiences of Hispanic faculty are provided.…

Hodge, Samuel R.; Cervantes, Carlos M.; Vigo-Valentin, Alexander N.; Canabal-Torres, Maria Y.; Ortiz-Castillo, Esther M.

2012-01-01

304

Proposed Laser-Based HED physics experiments for Stockpile Stewardship  

SciTech Connect

An analysis of the scientific areas in High Energy Density (HED) physics that underpin the enduring LANL mission in Stockpile Stewardship (SS) has identified important research needs that are not being met. That analysis has included the work done as part of defining the mission need for the High Intensity Laser Laboratory (HILL) LANL proposal to NNSA, LDRD DR proposal evaluations, and consideration of the Predictive Capability Framework and LANL NNSA milestones. From that evaluation, we have identified several specific and scientifically-exciting experimental concepts to address those needs. These experiments are particularly responsive to physics issues in Campaigns 1 and 10. These experiments are best done initially at the LANL Trident facility, often relying on the unique capabilities available there, although there are typically meritorious extensions envisioned at future facilities such as HILL, or the NIF once the ARC short-pulse laser is available at sufficient laser intensity. As the focus of the LANL HEDP effort broadens from ICF ignition of the point design at the conclusion of the National Ignition Campaign, into a more SS-centric effort, it is useful to consider these experiments, which address well-defined issues, with specific scientific hypothesis to test or models to validate or disprove, via unit-physics experiments. These experiments are in turn representative of a possible broad experimental portfolio to elucidate the physics of interest to these campaigns. These experiments, described below, include: (1) First direct measurement of the evolution of particulates in isochorically heated dense plasma; (2) Temperature relaxation measurements in a strongly-coupled plasma; (3) Viscosity measurements in a dense plasma; and (4) Ionic structure factors in a dense plasma. All these experiments address scientific topics of importance to our sponsors, involve excellent science at the boundaries of traditional fields, utilize unique capabilities at LANL, and contribute to the Campaign milestone in 2018. Given their interdisciplinary nature, it is not surprising that these research needs are not being addressed by the other excellent high-energy density physics (HEDP) facilities coming on line, facilities aimed squarely at more established fields and missions. Although energy rich, these facilities deliver radiation (e.g., particle beams for isochoric heating) over a timescale that is too slow in these unit physics experiments to eliminate hydrodynamic evolution of the target plasma during the time it is being created. A theme shared by all of these experiments is the need to quickly create a quasi-homogeneous 'initial state' whose properties and evolution we wish to study. Otherwise, we cannot create unit experiments to isolate the physics of interest and validate the models in our codes, something that cannot be done with the integrated experiments often done in HED. Moreover, these experiments in some cases involve combinations of solid and plasmas, or matter in the warm-dense matter state, where neither the theoretical approximations of solid state or of fully-ionized weakly-coupled plasmas can be used. In all cases, the capability of 'isochoric heating' ('flash' heating at constant density) is important. In some cases, the ability to selectively heat to different degrees different species within a target, whether mixed or adjacent to each other, is critical for the experiment. This capability requires the delivery of very high power densities, which require the conversion of the laser into very short and intense pulses of secondary radiation (electrons, ions, neutrons, x-rays). Otherwise, there is no possibility of a clean experiment to constrain the models, in the cases there are any, or inform the creation of one. Another typical requirement of these experiments is the ability to probe these exotic extreme conditions of matter with flexible and diverse sources of secondary radiation. Without a high-intensity high-power laser with some unique attributes available on Trident today (e.g., ultra-high laser-puls

Benage, John F. [Los Alamos National Laboratory; Albright, Brian J. [Los Alamos National Laboratory; Fernandez, Juan C. [Los Alamos National Laboratory

2012-09-04

305

Experiments with trapped atoms. Annual report, 1 Feb 90-31 Jan 91  

SciTech Connect

The authors current objective is to produce an intense slow atom beam and trap it in a magnetic trap. The atoms will be trapped by the forces of an inhomogenous magnetic field exerted on the magnetic moment of the atom. They have in mind several schemes which will greatly increase the density in the bottom of the trap. Dense samples of atoms cooled to microkelvin temperatures promise to open up new and exciting areas of physics. The lower interaction rate of the atoms due to their reduced thermal motion, together with the possibility of indefinitely long interaction times, make samples of trapped atoms ideal for high resolution spectroscopy and for use as atomic frequency standards PRI86. High density samples of ultra-cold atoms will also make it possible to study interatomic collisions in a new regime characterized by a long deBroglie wavelength, by the importance of weak forces, and by collision durations which are longer than radiative lifetimes so that absorption, stimulated and spontaneous radiative transitions take place during a collision. This opens the possibility of controlling the outcome of collisions by weak laser irradiation. High density samples of atoms at low temperature atoms are well suited in the search for quantum collective phenomena such as Bose-Einstein condensation.

Pritchard, D.E.

1991-04-10

306

NAVEX - A Space Shuttle Experiment with Atomic Clocks.  

National Technical Information Service (NTIS)

NAVEX is a navigation and time transfer experiment. It will be flown within the payload of the first German Spacelab mission D-1, scheduled in June 1985. The objectives of the experiment are to synchronize distant ground stations with an accuracy of bette...

H. Nau H. Tschiesche J. Hammesfahr S. Starker

1982-01-01

307

Review: Experiments in Fundamental Physics Scheduled and in Development for the ISS  

NASA Astrophysics Data System (ADS)

This is a review of those experiments in the area of Fundamental Physics that are either approved by ESA and NASA, or are currently under development, which are to be performed in the microgravity environment of the International Space Station. These experiments cover the physics of liquid Helium (SUE, BEST, MISTE, DYNAMX, and EXACT), ultrastable atomic clocks (PHARAO, PARCS, RACE), ultrastable microwave resonators (SUMO), and particle detectors (AMS and EUSO). The scientific goals are to study more precisely the universality properties of liquid Helium under microgravity conditions, to establish better time standards and to test the universality of the gravitational red shift, to make more precise tests of the constancy of the speed of light, and to measure the particle content in space directly without disturbances from the Earth's inner atmosphere.

Lämmerzahl, C.; Ahlers, G.; Ashby, N.; Barmatz, M.; Biermann, P. L.; Dittus, H.; Dohm, V.; Duncan, R.; Gibble, K.; Lipa, J.; Lockerbie, N.; Mulders, N.; Salomon, C.

2004-03-01

308

An Introductory Experience for Physical Chemistry: Victor Meyer Revisited  

NASA Astrophysics Data System (ADS)

An introductory experience for experimental physical chemistry is presented on JCE Online. The experiment incorporates a class determination of random error along with the determination of the molecular weight of a volatile liquid using a modified Victor Meyer procedure. Rapid data collection allows the class to amass a sizable data set for analysis. The experimental presentation contains a detailed write-up on the handling of random error and its propagation in subsequent calculations. A slight simplification of the Guedens et al. (J. Chem. Educ. 1993, 70, 776-779 and 838-841) treatment of statistical experimental error is presented at a student level. It can also be used as a trial experiment for report writing. Since it is based on the ideal gas law, it is consistent, in most cases, with the lecture material in a physical chemistry lecture-laboratory sequence.

Kundell, Frederick A.

1999-04-01

309

Industrial metrology as applied to large physics experiments  

SciTech Connect

A physics experiment is a large complex 3-D object (typ. 1200 m{sup 3}, 35000 tonnes), with sub-millimetric alignment requirements. Two generic survey alignment tasks can be identified; first, an iterative positioning of the apparatus subsystems in space and, second, a quantification of as-built parameters. The most convenient measurement technique is industrial triangulation but the complexity of the measured object and measurement environment constraints frequently requires a more sophisticated approach. To enlarge the ``survey alignment toolbox`` measurement techniques commonly associated with other disciplines such as geodesy, applied geodesy for accelerator alignment, and mechanical engineering are also used. Disparate observables require a heavy reliance on least squares programs for campaign pre-analysis and calculation. This paper will offer an introduction to the alignment of physics experiments and will identify trends for the next generation of SSC experiments.

Veal, D.

1993-05-01

310

The Advanced Light Source: A new tool for research in atomic and molecular physics  

SciTech Connect

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. 13 figs., 4 tabs.

Schlachter, F.; Robinson, A.

1991-04-01

311

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)

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, J L Hutchison, D C Smith, P Ashburn and C H de Groot Mechanism of atomic-scale passivation and flattening of semiconductor surfaces by wet-chemical preparationsKenta Arima, Katsuyoshi Endo, Kazuto Yamauchi, Kikuji Hirose, Tomoya Ono and Yasuhisa Sano Real-space calculations for electron transport properties of nanostructuresTomoya Ono, Shigeru Tsukamoto, Yoshiyuki Egami and Yoshitaka Fujimoto Thermally activated magnetization reversal in monatomic magnetic chains on surfaces studied by classical atomistic spin-dynamics simulationsDavid S G Bauer, Phivos Mavropoulos, Samir Lounis and Stefan Blügel An atomically controlled Si film formation process at low temperatures using atmospheric-pressure VHF plasmaK Yasutake, H Kakiuchi, H Ohmi, K Inagaki, Y Oshikane and M Nakano Single-nanometer focusing of hard x-rays by Kirkpatrick-Baez mirrorsKazuto Yamauchi, Hidekazu Mimura, Takashi Kimura, Hirokatsu Yumoto, Soichiro Handa, Satoshi Matsuyama, Kenta Arima, Yasuhisa Sano, Kazuya Yamamura, Koji Inagaki, Hiroki Nakamori, Jangwoo Kim, Kenji Tamasaku, Yoshinori Nishino, Makina Yabashi and Tetsuya Ishikawa Surface magnetism in O2 dissociation—from basics to applicationY Kunisada, M C Escaño and H Kasai Real-space finite-difference approach for multi-body systems: path-integral renormalization group method and direct energy minimization methodAkira Sasaki, Masashi Kojo, Kikuji Hirose and Hidekazu Goto Electrical conduction of organic ultrathin films evaluated by an independently driven double-tip scanning tunneling microscopeK Takami, S Tsuruta, Y Miyake, M Akai-Kasaya, A Saito, M Aono and Y Kuwahara

Kuwahara, Yuji; Kasai, Hideaki

2011-10-01

312

Advanced Experiments in Nuclear Science, Volume I: Advanced Nuclear Physics and Chemistry Experiments.  

ERIC Educational Resources Information Center

|The experiments in this manual represent state-of-the-art techniques which should be within the budgetary constraints of a college physics or chemistry department. There are fourteen experiments divided into five modules. The modules are on X-ray fluorescence, charged particle detection, neutron activation analysis, X-ray attenuation, and…

Duggan, Jerome L.; And Others

313

Various applications of atomic physics and kinetics codes to plasma modeling  

NASA Astrophysics Data System (ADS)

A collection of computer codes developed at Los Alamos have been applied to a variety of plasma modeling problems. The CATS, RATS, ACE, and GIPPER codes are used to calculate a consistent set of atomic physics data for a given problem. The calculated data include atomic energy levels, oscillator strengths, electron impact excitation and ionization cross sections, photoionization cross sections, and autoionization rates. The FINE and LINES codes access these data sets directly to perform plasma modeling calculations. Preliminary results of some of the current applications are presented, including, the calculation of holmium opacity, the modeling of plasma flat panel display devices, the analysis of some new results from the LANL TRIDENT laser and prediction of the radiative properties of the plasma wakefield light source for extreme ultraviolet lithography (EUVL). For the latter project, the simultaneous solution of atomic kinetics for the level populations and the Boltzmann equation for the electron energy distribution is currently being implemented.

Abdallah, J.; Clark, R. E. H.; Kilcrease, D. P.; Csanak, G.; Fontes, C. J.

1996-07-01

314

20 CFR 220.127 - When the only work experience is arduous unskilled physical labor.  

Code of Federal Regulations, 2013 CFR

...work experience is arduous unskilled physical labor. 220.127 Section 220...work experience is arduous unskilled physical labor. (a) Arduous work. Arduous work is primarily physical work requiring a high level of...

2013-04-01

315

PATHFINDER ATOMIC POWER PLANT. CLUSTERED PIN SUPERHEATER LATTICE EXPERIMENTS  

Microsoft Academic Search

Experiments to obtain detailed thermal flux distribution measurements ; within a unit fuel cell and measurements of sub-cadmium and epi-cadmium U²³⁸; absorption in the fuel rods are described. These quantities are required for ; determination of the thermal utilization and resonance escape probability of the ; fuel loading. (auth);

Selep

1963-01-01

316

Plans for atomic physics with highly-charged ions at Lanzhou  

Microsoft Academic Search

The upgraded radioactive ion beam line of Lanzhou and the project of the cooler storage ring of Lanzhou are presented in this\\u000a paper. The plans for atomic physics with highly charged ions at the cooler storage ring are discussed briefly, including precision\\u000a spectroscopy of highly charged ions, free- and laser-induced electron–ion recombination, test of special relativity, hyperfine\\u000a structure of radioactive

Xinwen Ma

1998-01-01

317

Atomic physics with highly charged ions. Progress report, August 15, 1994May 14, 1997  

Microsoft Academic Search

This document summarizes work carried out in the J.R. Macdonald Laboratory over the past three years under the project entitled {open_quotes}Atomic Physics with Highly Charged Ions.{close_quotes} The document presents summaries of most of the individual projects carried out in the laboratory over this period. The study of continuum electron production in collisions between highly charged ions and neutral targets has

1997-01-01

318

Simulations of the edge plasma: the role of atomic, molecular and surface physics  

Microsoft Academic Search

Atomic, molecular and surface physics plays an important role in simulations of the edge plasma in present day tokamaks, and in the predictive simulations of new devices. The edge plasma-in this context, the Scrape-Off Layer (SOL), the Private Flux Region (PFR) and core region close to the separatrix (or Last Closed Flux Surface, LCFS)-provides the boundary conditions for the main

D. P. Coster; X. Bonnin; D. Reiter; A. Kukushkin; S. Gori; P. Krstic; P. Strand; L.-G. Eriksson; Contributors to the EFDA-TF-ITM

2009-01-01

319

Understanding the learning assistant experience with physics identity  

NASA Astrophysics Data System (ADS)

Learning Assistants (LAs) have been shown to have better conceptual understanding and more favorable beliefs about science than non-LAs, and are more likely to choose a career in K-12 science teaching [1]. We propose that connections between elements of identity, persistence, and participation in an LA program can be explained using the concept of the community of practice and its intimate relationship to identity [2]. In separate work, Hazari et al. found that physics identity was highly correlated to expressed career plans in physics [3]. We hypothesize that a thriving LA program has many features of a well-functioning community of practice and contributes to all four elements of physics identity: personal interest, student performance, competence, and recognition by others. We explore how this analysis of the LA experience might shape decisions and influence outcomes of adoption and adaptations of the LA model.

Close, Eleanor W.; Close, Hunter G.; Donnelly, David

2013-01-01

320

Health physics practices and experience at Duke Power Company  

SciTech Connect

The history and development of the health physics and as-low-as-reasonably-achievable (ALARA) program at Duke Power Company's Oconee Nuclear Station is described as are the fundamental elements of the program and how the program works. The benefits of this health physics/ALARA program have been determined to be (a) improved quality of manpower planning and scheduling, (b) increased efficiency of shutdown activities, (c) reduced cost of shutdown, (d) immediate awareness of adverse job exposure trends, (e) better management information on exposure-related problems, (f) improved accuracy of personnel and job dose records, and (g) in general, improved outage performance and subsequent plant operation. Experience with the health physics/ALARA program is discussed in terms of (a) savings of critical path time, (b) maintaining ALARA personnel doses, and (c) record capacity factors.

Lewis, L.

1986-03-01

321

Alpha Particle Physics Experiments in the Tokamak Fusion Test Reactor  

SciTech Connect

Alpha particle physics experiments were done on the Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium (DT) run from 1993-1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single-particle confinement model in magnetohydrodynamic (MHD) quiescent discharges. Also, the observed alpha particle interactions with sawteeth, toroidal Alfvén eigenmodes (TAE), and ion cyclotron resonant frequency (ICRF) waves were roughly consistent with theoretical modeling. This paper reviews what was learned and identifies what remains to be understood.

Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Zweben, S.J.; et al.

1998-12-14

322

Tevatron End-of-Run Beam Physics Experiments  

SciTech Connect

Before the Tevatron Collider Run II ended in September of 2011, a number of specialized beam study periods were dedicated to the experiments on various accelerator physics concepts and effects during the last year of the machine operation. The study topics included collimation with bent crystals and hollow electron beams, diffusion measurements and various aspects of beam-beam interactions. In this report we concentrate on the subject of beam-beam interactions, summarizing the results of beam experiments. The covered topics include offset collisions, coherent beam stability, effect of the bunch-length-to-beta-function ratio, and operation of AC dipole with colliding beams.

Valishev, A.; /Fermilab; Gu, X.; Miyamoto, R.; White, S.; /BNL; Schmidt, F.; /CERN; Qiang, J.; /LBNL

2012-05-01

323

An EPR Experiment for the Undergraduate Physical Chemistry Laboratory  

Microsoft Academic Search

An experiment that illustrates the principles of electron paramagnetic resonance spectroscopy in the undergraduate physical chemistry laboratory is described. Students measure the value of g for DPPH and use it to determine the value of g for two inorganic complexes, Cu(acac)2 and VO(acac)2. The students use two instruments: an instructional device that illustrates the principles of EPR and a commercial

R. A. Butera; D. H. Waldeck

2000-01-01

324

Conductive education for physically handicapped children: parental expectations and experience.  

PubMed Central

Conductive education, an educational approach devised by Andras Petö in Hungary after the second world war, has attracted considerable media attention. Eight Northern Ireland families who recently had treatment for their disabled child at the Petö Institute in Budapest were identified. Six families returned postal questionnaires designed to look at parental experience of conductive education. An improvement in existing local services, as opposed to the wholesale introduction of this facility was the commonest parental hope for future provision for physically handicapped children.

Hill, A. E.

1990-01-01

325

Physics results with the ARGO-YBJ experiment  

NASA Astrophysics Data System (ADS)

ARGO-YBJ is a multipurpose experiment consisting in a dense sampling air shower array with 93% sensitive area located at very high altitude. The apparatus is in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, PR China, 4300 m a.s.l., 606 g/cm2). In this paper we report the main results in Gamma-Ray Astronomy and Cosmic Ray Physics after about 3 years of operation.

D'Ettorre Piazzoli, Benedetto

2013-01-01

326

Monolithic electronics for nuclear and high-energy physics experiments  

SciTech Connect

Electronic instrumentation for large fixed-target and collider experiments is rapidly moving to the use of highly integrated electronics wherever it is cost effective. This trend is aided by the development of circuit building blocks useful for nuclear and high-energy physics instrumentation and has accelerated recently with the development of monolithic silicon chips with multiple functions on one substrate. Examples of recent developments are given, together with remarks on the rationale for use of monolithic electronics and economic considerations.

Young, G.R.

1994-12-31

327

Quench detection & instrumentation for the Tokamak Physics Experiment magnets  

Microsoft Academic Search

The design of the Local Instrumentation & Control (I&C) System for the Tokamak Physics Experiment (TPX) superconducting PF & TF magnets is presented. The local I&C system monitors the status of the magnet systems and initiates the proper control sequences to protect the magnets from any foreseeable fault. Local I&C also stores magnet-system data for analysis and archiving. Quench Detection

M. R. Chaplin; W. V. Hassenzahl; J. H. Schultz

1993-01-01

328

On the Limitations of Thought Experiments in Physics and the Consequences for Physics Education.  

ERIC Educational Resources Information Center

|Focuses on the role of Thought Experiments (TEs) in ongoing processes of conceptual refinement for physicists and physics learners. Analyze TEs related to stellar evolution and general relativity. Identifies the stages at which crucial errors are made in these TEs and the cognitive processes which lead to these errors. Discusses implications for…

Reiner, Miriam; Burko, Lior M.

2003-01-01

329

Experiences of Psychological and Physical Aggression in Adolescent Romantic Relationships: Links to Psychological Distress  

ERIC Educational Resources Information Center

Objective: This research examined links between adolescents' experiences of psychological and physical relationship aggression and their psychological distress. Experiences of psychological and physical aggression were expected to correlate positively with symptoms of psychological distress, but experiences of psychological aggression were…

Jouriles, Ernest N.; Garrido, Edward; Rosenfield, David; McDonald, Renee

2009-01-01

330

Experiences of Psychological and Physical Aggression in Adolescent Romantic Relationships: Links to Psychological Distress  

ERIC Educational Resources Information Center

|Objective: This research examined links between adolescents' experiences of psychological and physical relationship aggression and their psychological distress. Experiences of psychological and physical aggression were expected to correlate positively with symptoms of psychological distress, but experiences of psychological aggression were…

Jouriles, Ernest N.; Garrido, Edward; Rosenfield, David; McDonald, Renee

2009-01-01

331

Feasibility guidelines for kaonic atom experiments with ultra-high-resolution X-ray spectrometry  

NASA Astrophysics Data System (ADS)

Recent studies of strong-interaction effects in kaonic atoms suggest that analysing so-called 'lower' and 'upper' levels in the same atom could separate one-nucleon absorption from multinucleon processes. The present work examines the feasibility of direct measurements of upper level widths in addition to lower level widths in future experiments, using superconducting microcalorimeter detectors. About ten elements are identified as possible candidates for such experiments, all of medium-weight and heavy nuclei. New experiments focused on achieving good accuracy for widths of such pairs of levels could contribute significantly to our knowledge of the K?–nucleon interaction in the nuclear medium.

Friedman, E.; Okada, S.

2013-10-01

332

Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)  

SciTech Connect

The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE.

C.E. Kessel; D. Meade; S.C. Jardin

2002-01-18

333

Physical basis of coastal productivity: The SEEP and MASAR experiments  

NASA Astrophysics Data System (ADS)

Two major cooperative experiments, code-named Shelf Edge Exchange Processes (SEEP) I and II, were carried out on the northeast U.S. continental shelf and slope by an interdisciplinary group of scientists in the past decade. The work, supported by the Department of Energy, Office of Health and Environmental Research, had the broad aim of determining whether or to what extent energy-related human activities interfere with the high biological productivity of coastal waters. Much of SEEP I work was reported in a dedicated issue of Continental Shelf Research, including a summary article on the experiment as a whole [Walsh et al., 1988[. A parallel experiment, supported by the Minerals Management Service and code-named Mid Atlantic Slope and Rise (MASAR), had the objective of exploring physical processes over the continental slope and rise, including especially currents in the upper part of the water column. A good deal of MASAR work was also reported in the SEEP issue just mentioned, mainly in an article by Csanady and Hamilton (1988). There have been other papers and publications on these experiments, and more are forthcoming. While many questions remain, our horizons have broadened considerably after a decade of work on this problem, as if our aeroplane had just emerged from clouds to expose an interesting landscape. In this article I shall try to describe the physical (-oceanographic) features of that landscape, not in the chronological order in which we have espied them, but as the logic of the subject dictates.

Csanady, G. T.

334

Testing atomic and collision physics, QED, Plasma Physics, Laboratory Astrophysics and Fundamental Constants a visible, VUV, X-ray synchrotron source allied with an Electron Beam Ion Trap  

NASA Astrophysics Data System (ADS)

Recent Australian expertise in developing atomic and collision physics, new tests of QED, Plasma Physics and Synchrotron Science is pooled in a proposal to unite the novel sources of a synchrotron beam-line across energy regimes with an Electron Beam Ion Trap to produce a unique tool for advancing fundamental research and physics including plasma physics, laboratory astrophysics, investigations of the constancy of fundamental constants of nature and tests of QED.

Chantler, Christopher T.

2012-11-01

335

Introductory Physics Experiments Using the Wii Balance Board  

NASA Astrophysics Data System (ADS)

The Wii, a video game console by Nintendo, utilizes several different controllers, such as the Wii remote (Wiimote) and the balance board, for game-playing. The balance board was introduced in early 2008. It contains four strain gauges and has Bluetooth connectivity at a relatively low price. Thanks to available open source code, such as GlovePie, any PC with Bluetooth capability can detect the information sent out by the balance board. Based on the ease with which the forces measured by each strain gauge can be obtained, we have designed several experiments for introductory physics courses that make use of this device. We present experiments to measure the forces generated when students lift their arms with and without added weights, distribution of forces on an extended object when weights are repositioned, and other normal forces cases. The results of our experiments are compared with those predicted by Newtonian mechanics. )

Starr, Julian; Sobczak, Robert; Iqbal, Zohaib; Ochoa, Romulo

2010-02-01

336

Source physics experiments at the Nevada Test Site.  

SciTech Connect

The U. S. capability to monitor foreign underground nuclear test activities relies heavily on measurement of explosion phenomena, including characteristic seismic, infrasound, radionuclide, and acoustic signals. Despite recent advances in each of these fields, empirical, rather than physics-based, approaches are used to predict and explain observations. Seismologists rely on prior knowledge of the variations of teleseismic and regional seismic parameters such as p- and s-wave arrivals from simple one-dimensional models for the teleseismic case to somewhat more complicated enhanced two-dimensional models for the regional case. Likewise, radionuclide experts rely on empirical results from a handful of limited experiments to determine the radiological source terms present at the surface after an underground test. To make the next step in the advancement of the science of monitoring we need to transform these fields to enable predictive, physics-based modeling and analysis. The Nevada Test Site Source Physics Experiments (N-SPE) provide a unique opportunity to gather precise data from well-designed experiments to improve physics-based modeling capability. In the seismic experiments, data collection will include time domain reflectometry to measure explosive performance and yield, free-field accelerometers, extensive seismic arrays, and infrasound and acoustic measurements. The improved modeling capability that we will develop using this data should enable important advances in our ability to monitor worldwide for nuclear testing. The first of a series of source physics experiments will be conducted in the granite of Climax Stock at the NTS, near the locations of the HARD HAT and PILE DRIVER nuclear tests. This site not only provides a fairly homogeneous and well-documented geology, but also an opportunity to improve our understanding of how fractures, joints, and faults affect seismic wave generation and propagation. The Climax Stock experiments will consist of a 220 lb (TNT equivalent) calibration shot and a 2200 lb (TNT equivalent) over-buried shot conducted in the same emplacement hole. An identical 2200 lb shot at the same location will follow to investigate the effects of pre-conditioning. These experiments also provide an opportunity to advance capabilities for near-field monitoring, and on-site inspections (OSIs) of suspected testing sites. In particular, geologic, physical, and cultural signatures of underground testing can be evaluated using the N-SPE activities as case studies. Furthermore, experiments to measure the migration of radioactive noble gases to the surface from underground explosions will enable development of higher fidelity radiological source term models that can predict migration through a variety of geologic conditions. Because the detection of short-lived radionuclides is essential to determining if an explosion was nuclear or conventional, a better understanding of the gaseous and particulate radionuclide source terms that reach the surface from underground testing is critical to development of OSI capability.

Lee, Ping (Nuclear Security Technologies, Inc.); Snelson, Catherine (Nuclear Security Technologies, Inc.); Abbott, Robert; Coblentz, David D. (Los Alamos National Laboratory); Corbell, Robert; Bowyer, Theodore W. (Pacific Northwest National Laboratory); Sussman, Aviva J. (Los Alamos National Laboratory); Carrigan, Charles R. (Lawrence Livermore National Laboratory); Bradley, Christopher R. (Los Alamos National Laboratory); Patton, Howard J. (Los Alamos National Laboratory); Seifert, Carolyn E. (Pacific Northwest National Laboratory); Sweeney, Jerry J. (Lawrence Livermore National Laboratory); Brunish, Wendee M. (Los Alamos National Laboratory); Hawkins, Ward L. (Los Alamos National Laboratory); Antoun,Tarabay H. (Lawrence Livermore National Laboratory); Wohletz, Kenneth H. (Los Alamos National Laboratory); Zucca, John Jay (Lawrence Livermore National Laboratory)

2010-10-01

337

Experiments on Quantum Transport of Ultra-Cold Atoms in Optical Potentials  

Microsoft Academic Search

In this chapter, we describe our experiments with ultra cold atoms in optical potentials and show how we can address fundamental\\u000a issues of time in quantum mechanics. The high degree of experimental control and the conceptual simplicity are the main advantages\\u000a of our system. We start with an overview of the basic interaction of atoms and light and make the

Martin C. Fischer; Mark G. Raizen

338

Quantum-nondemolition measurements using cold trapped atoms: Comparison between theory and experiment  

Microsoft Academic Search

In this paper we present a detailed theoretical analysis of a recent quantum-nondemolition experiment in optics using cold atoms in a magneto-optical trap as a nonlinear medium. A signal beam and a meter beam from two independent lasers are coupled within a Lambda-type three-level scheme in the D1 line of 87Rb atoms. The experimental results for the relevant quantum correlations

A. Sinatra; J. F. Roch; K. Vigneron; Ph. Grelu; J.-Ph. Poizat; Kaige Wang; P. Grangier

1998-01-01

339

Atomic impact experiments with free helium-3 and helium-4 clusters  

Microsoft Academic Search

Free helium clusters with of the order of 103 to 107 atoms have been predicted to reach final temperatures of about 0.4 K in the case of4He, and of 0.15 K in the case of3He. In the first case, the clusters have to be expected to be superfluid, in the latter case to be normalfluid. Impact experiments with cesium atoms,

Jürgen Gspann

1995-01-01

340

Experiences of physical activity during pregnancy in Danish nulliparous women with a physically active life before pregnancy. A qualitative study  

Microsoft Academic Search

BACKGROUND: National guidelines recommend that healthy pregnant women take 30 minutes or more of moderate exercise a day. Most women reduce the level of physical activity during pregnancy but only a few studies of women's experiences of physical activity during pregnancy exist. The aim of the present study was to elucidate experiences and views of leisure time physical activity during

Hanne K Hegaard; Hanne Kjaergaard; Peter P Damm; Kerstin Petersson; Anna-Karin Dykes

2010-01-01

341

Experience Using Formal Methods in High Energy Physics  

NASA Astrophysics Data System (ADS)

We report our experience using the formal method VDM++ in high energy physics real-time applications. VDM++ is an extension of the established formal method VDM to include object-oriented, concurrency and real-time features. VDM++ is supported by the VENUS tool-set, comprising an OMT graphical editor, VDM++ syntax and type checker, and a C++ code generator. Formal specification meta-languages allow formal data modeling, algorithm and system behavior specification at a highly abstract level. Once an abstract design has converged it is refined towards a particular implementation, with formal validation of each step if desired. We have applied VDM++ to the design of a fast track pattern recognition algorithm; the design of a global second- level trigger system for LHC experiments; the specification of simulated physics data; and the design of a data router hardware unit for a LHC second-level trigger. We are encouraged by the application of mathematics in an engineering discipline and conclude that formal methods have the potential to make a valuable contribution to the systems development process in high energy physics.

Balke, A. C.; Carter, J.; Haveman, J.

342

2s Hyperfine splitting in light hydrogen-like atoms: Theory and experiment  

SciTech Connect

Since the combination D{sub 21} = 8f{sub HFS}(2s)-f{sub HFS}(1s) of hyperfine intervals in hydrogen and light two-body hydrogen-like atomic systems weakly depends on the nuclear structure, comparison between theory and experiment can be sensitive to high order QED corrections. New theoretical and experimental results are presented. Calculations have been performed for the hydrogen and deuterium atoms and for the helium-3 ion. Experiments on the 2s hyperfine splitting (responsible for the dominant contribution to the error in D{sub 21}) have been conducted for hydrogen and deuterium. The theory and experiment are in good agreement, and their accuracy is comparable to that attained in verifying the QED theory of the hyperfine splitting in leptonic atoms (muonium and positronium)

Karshenboim, S. G. [D.I. Mendeleev Institute for Metrology (Russian Federation)], E-mail: sgk@vniim.ru; Kolachevsky, N. N. [Max-Planck-Institut fuer Quantenoptik (Germany); Ivanov, V. G. [Russian Academy of Sciences, Pulkovo Astronomical Observatory (Russian Federation); Fischer, M.; Fendel, P.; Haensch, T. W. [Max-Planck-Institut fuer Quantenoptik (Germany)

2006-03-15

343

Flavour physics and the Large Hadron Collider beauty experiment.  

PubMed

An exciting new era in flavour physics has just begun with the start of the Large Hadron Collider (LHC). The LHCb (where b stands for beauty) experiment, designed specifically to search for new phenomena in quantum loop processes and to provide a deeper understanding of matter-antimatter asymmetries at the most fundamental level, is producing many new and exciting results. It gives me great pleasure to describe a selected few of the results here-in particular, the search for rare B(0)(s)-->?+ ?- decays and the measurement of the B(0)(s) charge-conjugation parity-violating phase, both of which offer high potential for the discovery of new physics at and beyond the LHC energy frontier in the very near future. PMID:22253243

Gibson, Valerie

2012-02-28

344

Unpacking Gender Differences in Students' Perceived Experiences in Introductory Physics  

NASA Astrophysics Data System (ADS)

Prior research has shown, at our institution: 1) males outperform females on conceptual assessments (a gender gap), 2) the gender gap persists despite the use of research-based reforms, and 3) the gender gap is correlated with students' physics and mathematics background and prior attitudes and beliefs [Kost, et al. PRST-PER, 5, 010101]. Our follow-up work begins to explore how males and females experience the introductory course differently and how these differences relate to the gender gap. We gave a survey to students in the introductory course in which we investigated students' physics identity and self-efficacy. We find there are significant gender differences in each of these three areas, and further find that these measures are weakly correlated with student conceptual performance, and moderately correlated with course grade.

Kost, Lauren E.; Pollock, Steven J.; Finkelstein, Noah D.

2009-11-01

345

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics  

SciTech Connect

The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where groundbreaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999 [1]. A survey of physics capabilities of the CMS detector was published in [2]. The design of the ATLAS detector has now been finalised, and its construction and installation have been completed [3]. An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have been completely rewritten. Revisions incorporated reflect improved detector modelling as well as major technical changes to the software technology. Greatly improved understanding of calibration and alignment techniques, and their practical impact on performance, is now in place. The studies reported here are based on full simulations of the ATLAS detector response. A variety of event generators were employed. The simulation and reconstruction of these large event samples thus provided an important operational test of the new ATLAS software system. In addition, the processing was distributed world-wide over the ATLAS Grid facilities and hence provided an important test of the ATLAS computing system - this is the origin of the expression 'CSC studies' ('computing system commissioning'), which is occasionally referred to in these volumes. The work reported does generally assume that the detector is fully operational, and in this sense represents an idealised detector: establishing the best performance of the ATLAS detector with LHC proton-proton collisions is a challenging task for the future. The results summarised here therefore represent the best estimate of ATLAS capabilities before real operational experience of the full detector with beam. Unless otherwise stated, simulations also do not include the effect of additional interactions in the same or other bunch-crossings, and the effect of neutron background is neglected. Thus simulations correspond to the low-luminosity performance of the ATLAS detector. This report is broadly divided into two parts: firstly the performance for identification of physics objects is examined in detail, followed by a detailed assessment of the performance of the trigger system. This part is subdivided into chapters surveying the capabilities for charged particle tracking, each of electron/photon, muon and tau identification, jet and missing transverse energy reconstruction, b-tagging algorithms and performance, and finally the trigger system performance. In each chapter of the report, there is a further subdivision into shorter notes describing different aspects studied. The second major subdivision of the report addresses physics measurement capabilities, and new physics search sensitivities. Individual chapters in this part discuss ATLAS physics capabilities in Standard Model QCD and electroweak processes, in the top quark sector, in b-physics, in searches for Higgs bosons, supersymmetry searches, and finally searches for other new particles predicted in more exotic models.

Aad, G.; Abat, E.; Abbott, B.; Abdallah, J.; Abdelalim, A.A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Acharya, Bobby Samir; Adams, D.L.; Addy, T.N.; Adorisio, C.; Adragna, P.; Adye, T.; Aguilar-Saavedra, J.A.; Aharrouche, M.; Ahlen, S.P.; Ahles, F.; Ahmad, A.; /SUNY, Albany /Alberta U. /Ankara U. /Annecy, LAPP /Argonne /Arizona U. /Texas U., Arlington /Athens U. /Natl. Tech. U., Athens /Baku, Inst. Phys. /Barcelona, IFAE /Belgrade U. /VINCA Inst. Nucl. Sci., Belgrade /Bergen U. /LBL, Berkeley /Humboldt U., Berlin /Bern U., LHEP /Birmingham U. /Bogazici U. /INFN, Bologna /Bologna U.

2011-11-28

346

Planar position sensitive Ge(i)- and Si(Li)-detector systems for Compton Polarimetry in Atomic Physics with Highly Charged Ions  

NASA Astrophysics Data System (ADS)

Planar position-, energy-, and time-dispersive semiconductor detector systems have shown their excellent performance in Compton Polarimetry and X-ray Imaging in the realm of Atomic Physics Experiments with Highly Charged Ions. We report on two of these detector systems and discuss the importance of this kind of detector systems for the present and future experimental programm of the SPARC collaboration at GSI and FAIR.

Spillmann, U.; Blumenhagen, K.-H.; Bräuning, H.; Weber, G.; Stöhlker, Th

2012-11-01

347

The International Reactor Physics Experiment Evaluation Project (IRPHEP)  

SciTech Connect

Since the beginning of the Nuclear Power industry, numerous experiments concerned with nuclear energy and technology have been performed at different research laboratories, worldwide. These experiments required a large investment in terms of infrastructure, expertise, and cost; however, many were performed without a high degree of attention to archival of results for future use. The degree and quality of documentation varies greatly. There is an urgent need to preserve integral reactor physics experimental data, including measurement methods, techniques, and separate or special effects data for nuclear energy and technology applications and the knowledge and competence contained therein. If the data are compromised, it is unlikely that any of these experiments will be repeated again in the future. The International Reactor Physics Evaluation Project (IRPhEP) was initiated, as a pilot activity in 1999 by the by the Organization of Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA) Nuclear Science Committee (NSC). The project was endorsed as an official activity of the NSC in June of 2003. The purpose of the IRPhEP is to provide an extensively peer reviewed set of reactor physics related integral benchmark data that can be used by reactor designers and safety analysts to validate the analytical tools used to design next generation reactors and establish the safety basis for operation of these reactors. A short history of the IRPhEP is presented and its purposes are discussed in this paper. Accomplishments of the IRPhEP, including the first publication of the IRPhEP Handbook, are highlighted and the future of the project outlined.

J. Blair Briggs; Enrico Sartori; Lori Scott

2006-09-01

348

Three-dimensional modelling of the analyte dynamics in electrothermal atomizers for analytical spectrometry: influence of physical factors  

Microsoft Academic Search

A computer model has been developed that allows the calculation of the three-dimensional distributions of free atoms and condensed particles inside tube-type electrothermal atomizers. This model is a numerical solution of the three-dimensional diffusion equation written with the appropriate boundary conditions. The proposed model takes the following geometrical and physical factors into account: real tube geometry of an atomizer provided

A. Kh. Gilmutdinov; R. M. Mrasov; A. R. Somov; C. L. Chakrabarti; J. C. Hutton

1995-01-01

349

Double beta decay: A problem of particle, nuclear and atomic physics  

NASA Astrophysics Data System (ADS)

A brief review of recent progress in the field of double beta decay is presented. Different aspects from particle, nuclear and atomic physics of both two-neutrino (2???) and neutrinoless (0???) modes of the double ? decay are discussed. It is argued that the R-parity violating supersymmetry (?RpSUSY) contributes to the 0???-decay predominantly via charged pion-exchange between decaying nucleons. Further, a problem of reliable determination of the 0???-decay nuclear matrix elements (NMEs) is addressed. It is manifested that the uncertainty associated with the calculation of the 0???-decay NMEs can be diminished by suitably chosen nuclear probes. A new possibility for the study of lepton number non-conservation is proposed, namely oscillations plus deexcitations of neutral atoms. A phenomenological analysis of this process leads to a resonant enhancement of the neutrinoless double electron capture, that has a Breit-Wigner form.

Šimkovic, Fedor

2010-04-01

350

Atomic physics studies of highly charged ions on tokamaks using x-ray spectroscopy  

SciTech Connect

An overview is given of atomic physics issues which have been studied on tokamaks with the help resolution x-ray spectroscopy. The issues include the testing of model calculations predicting the excitation of line radiation, the determination of rate coefficients, and accurate atomic structure measurements. Recent research has focussed primarily on highly charged heliumlike (22 less than or equal to Z less than or equal to 28) and neonlike (34 less than or equal to Z less than or equal to 63) ions, and results are presented from measurements on the PLT and TFTR tokamaks. Many of the measurements have been aided by improved instrumental design and new measuring techniques. Remarkable agreement has been found between measurements and theory in most cases. However, in this review those areas are stressed where agreement is worst and where further investigations are needed. 19 refs., 13 figs., 2 tabs.

Beiersdorfer, P.; von Goeler, S.; Bitter, M.; Hill, K.W.

1989-07-01

351

The BAIKAL neutrino experiment—Physics results and perspectives  

NASA Astrophysics Data System (ADS)

We review the status of the Lake Baikal Neutrino Experiment. The Neutrino Telescope NT200 has been operating since 1998 and has been upgraded to the 10 Mton detector NT200+ in 2005. We present selected astroparticle physics results from long-term operation of NT200. Also discussed are activities towards acoustic detection of UHE-energy neutrinos, and results of associated science activities. Preparation towards a km3-scale (Gigaton volume) detector in Lake Baikal is currently a central activity. As an important milestone, a km3-prototype string, based on completely new technology, has been installed and is operating together with NT200+ since April, 2008.

Aynutdinov, V.; Avrorin, A.; Balkanov, V.; Belolaptikov, I.; Bogorodsky, D.; Budnev, N.; Danilchenko, I.; Domogatsky, G.; Doroshenko, A.; Dyachok, A.; Dzhilkibaev, Zh.-A.; Fialkovsky, S.; Gaponenko, O.; Golubkov, K.; Gress, O.; Gress, T.; Grishin, O.; Klabukov, A.; Klimov, A.; Kochanov, A.; Konischev, K.; Koshechkin, A.; Kulepov, V.; Kuleshov, D.; Kuzmichev, L.; Lovtsov, S.; Middell, E.; Mikheyev, S.; Milenin, M.; Mirgazov, R.; Osipova, E.; Pan'Kov, G.; Pan'Kov, L.; Panfilov, A.; Petukhov, D.; Pliskovsky, E.; Pokhil, P.; Poleschuk, V.; Popova, E.; Rastegin, A.; Prosin, V.; Rozanov, M.; Rubtzov, V.; Sheifler, A.; Shirokov, A.; Shoibonov, B.; Spiering, Ch.; Suvorova, O.; Tarashansky, B.; Wischnewski, R.; Yashin, I.; Zhukov, V.

2009-04-01

352

Preliminary Safety Analysis Report for the Tokamak Physics Experiment  

SciTech Connect

This Preliminary Safety Analysis Report (PSAR), includes an indication of the magnitude of facility hazards, complexity of facility operations, and the stage of the facility life-cycle. It presents the results of safety analyses, safety assurance programs, identified vulnerabilities, compensatory measures, and, in general, the rationale describing why the Tokamak Physics Experiment (TPX) can be safely operated. It discusses application of the graded approach to the TPX safety analysis, including the basis for using Department of Energy (DOE) Order 5480.23 and DOE-STD-3009-94 in the development of the PSAR.

Motloch, C.G.; Bonney, R.F. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Levine, J.D. [Princeton Univ., NJ (United States). Plasma Physics Lab.; McKenzie-Carter, M.A. [Science Applications International Corp., San Diego, CA (United States); Masson, L.S. [SCIENTECH, Inc., Idaho Falls, ID (United States); Commander, J.C.

1995-04-01

353

Chladni Patterns on Drumheads: A ``Physics of Music'' Experiment  

NASA Astrophysics Data System (ADS)

In our ``Physics of Music'' class for non-science majors, we have developed a laboratory exercise in which students experiment with Chladni sand patterns on drumheads. Chladni patterns provide a kinesthetic, visual, and entertaining way to illustrate standing waves on flat surfaces and are very helpful when making the transition from one-dimensional systems, such as string and wind instruments, to the two-dimensional membranes and plates of the percussion family. Although the sand patterns attributed to Ernst Florens Friedrich Chladni1 (1756-1827) are often demonstrated for this purpose using metal plates,2-4 the use of drumheads offers several pedagogical and practical advantages in the lab.

Worland, Randy

2011-01-01

354

Physical mechanism of the Schwarzschild effect in film dosimetry—theoretical model and comparison with experiments  

NASA Astrophysics Data System (ADS)

In consideration of the importance of film dosimetry for the dosimetric verification of IMRT treatment plans, the Schwarzschild effect or failure of the reciprocity law, i.e. the reduction of the net optical density under 'protraction' or 'fractionation' conditions at constant dose, has been experimentally studied for Kodak XOMAT-V (Martens et al 2002 Phys. Med. Biol. 47 2221-34) and EDR 2 dosimetry films (Djouguela et al 2005 Phys. Med. Biol. 50 N317-N321). It is known that this effect results from the competition between two solid-state physics reactions involved in the latent-image formation of the AgBr crystals, the aggregation of two Ag atoms freshly formed from Ag+ ions near radiation-induced occupied electron traps and the spontaneous decomposition of the Ag atoms. In this paper, we are developing a mathematical model of this mechanism which shows that the interplay of the mean lifetime ? of the Ag atoms with the time pattern of the irradiation determines the magnitude of the observed effects of the temporal dose distribution on the net optical density. By comparing this theory with our previous protraction experiments and recent fractionation experiments in which the duration of the pause between fractions was varied, a value of the time constant ? of roughly 10 s at room temperature has been determined for EDR 2. The numerical magnitude of the Schwarzschild effect in dosimetry films under the conditions generally met in radiotherapy amounts to only a few per cent of the net optical density (net OD), so that it can frequently be neglected from the viewpoint of clinical applications. But knowledge of the solid-state physical mechanism and a description in terms of a mathematical model involving a typical time constant of about 10 s are now available to estimate the magnitude of the effect should the necessity arise, i.e. in cases of large fluctuations of the temporal pattern of film exposure.

Djouguela, A.; Kollhoff, R.; Rühmann, A.; Willborn, K. C.; Harder, D.; Poppe, B.

2006-09-01

355

On the Limitations of Thought Experiments in Physics and the Consequences for Physics Education  

NASA Astrophysics Data System (ADS)

Thought experiments (TEs) play a central role in physics. We suggest that erroneous TEs may be as important as correct TEs, and that both have a special role in an ongoing process of conceptual refinement for physicists and for naive physics learners. We analyze TEs related to stellar evolution and general relativity made by Schwarzschild, Eddington, Landau, and Einstein. We identify the stages at which crucial errors are done in these TEs, and the cognitive processes which lead to these errors. We argue that necessary conditions for a successful TE (i.e., a TE which leads to correct conclusions)are self-consistency and comprehensiveness of the relevant picture of the world. We show that the TEs by expert physicists and TEs by students are similar on a metacognitive level, but different in details. Students' erroneous reasoning occur in all stages of a TE, whereas physicists usually make errors in the first two stages of TEs. Then we bring evidence that Tesare more prone to errors than laboratory experiments. Next we discuss the implications for naive physics learners, and make suggestion for using TEs in physics education.

Reiner, Miriam; Burko, Lior M.

356

Report of the Joint Seminar on Solid State Physics, Atomic and Molecular Physics, and Materials Science in the Energy Region of Tandem Accelerators  

Microsoft Academic Search

The Joint Seminar on Solid State Physics, Atomic and Molecular Physics, and Materials Science in the Energy Region of Tandem Acceleration was held at Tokai Research Establishment of JAERI for two days from January 22 to 23, 1991. About 60 physicists and material scientists participated and 18 papers were presented in this seminar. The topics presented in this seminar included

Yukio Kazumata

1993-01-01

357

Nuclear-Spin-Independent Short-Range Three-Body Physics in Ultracold Atoms  

SciTech Connect

We investigate three-body recombination loss across a Feshbach resonance in a gas of ultracold {sup 7}Li atoms prepared in the absolute ground state and perform a comparison with previously reported results of a different nuclear-spin state [N. Gross et al., 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.

Gross, Noam; Shotan, Zav; Khaykovich, Lev [Department of Physics, Bar-Ilan University, Ramat-Gan, 52900 (Israel); Kokkelmans, Servaas [Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven (Netherlands)

2010-09-03

358

Majorana end modes in STM Fabricated Atomic Chains on the Surface of a Superconductor: Theory & Experiment  

NASA Astrophysics Data System (ADS)

The search for Majorana fermions (MF) in solid state devices has been hampered by the possible affects of disorder which may induce signatures similar to those expected by novel MF boundary states. Therefore it is important to identify clean solid state systems in which MF modes can be easily distinguished from disorder related effects. In this talk, we will present theoretical calculations and preliminary experimental results on chains of magnetic atoms on the surface of an s-wave superconductors. The theoretical efforts show that surprisingly short magnetic chains (20 atoms long or more) support MF under specific conditions depending on spins of the magnetic atoms and their coupling. We will describe these theoretical results along with experiments in which a scanning tunneling microscopy (STM) has been used to assemble chains of magnetic atoms (3d transition metals) on Nb and Pb single crystals. Presence of Majorana boundary modes in these structures can be probed using spatially-resolved STM spectroscopy.

Nadj-Perge, Stevan; Drozdov, Ilya; Seo, Jungpil; Bernevig, Andrei; Yazdani, Ali

2013-03-01

359

The FrPNC experiment at TRIUMF: Atomic parity non-conservation in francium  

NASA Astrophysics Data System (ADS)

The FrPNC collaboration has begun the construction of an on-line laser cooling and trapping apparatus at TRIUMF to measure atomic parity non-conservation (PNC) and the nuclear anapole moment in a string of artificially produced francium isotopes. Atomic PNC experiments provide unique high precision tests of the electroweak sector of the Standard Model at very low energies. Furthermore, precision measurements of spin-dependent atomic PNC can determine nuclear anapole moments and probe the weak force within the nucleus. Francium is an excellent candidate for precision measurements of atomic PNC due to its simple electronic structure and enhanced parity violation: both the optical PNC and anapole moment signals are expected to be over an order of magnitude larger than in cesium.

Aubin, S.; Gomez, E.; Behr, J. A.; Pearson, M. R.; Sheng, D.; Zhang, J.; Collister, R.; Melconian, D.; Flambaum, V. V.; Sprouse, G. D.; Orozco, L. A.; Gwinner, G.

2012-04-01

360

A High Flux Cold Atomic Beam for Experiments in Strongly Coupled Cavity QED  

NASA Astrophysics Data System (ADS)

We present a high flux continuous source of cold atoms for cavity QED experiments in the regime of strong coupling. A 2D+ MOT, loaded by rubidium dispensers in a dry film coated vapor cell, loads a secondary moving-molasses MOT (MM-MOT) at a rate of 1.5*10^10 atoms/s. The MM-MOT provides a velocity tunable (3 to 10 m/s) high flux continuous beam. We direct the beam through the 64 ?m waist of a high finesse optical cavity with 246 ?m mirror spacing. The atom-cavity coupling rate g, cavity dissipation rate ?, and atomic decay rate ? are (g, ?, ?)/2? = (8, 2, 3) MHz, placing the system in the strong regime. We are currently characterizing the source using the cavity QED system and will report its performance as a function of MOT parameters.

Roy, Basudev; Scholten, Michael; Orozco, Luis; Wu, Saijun

2008-05-01

361

Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course  

ERIC Educational Resources Information Center

|An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of…

Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey

2004-01-01

362

ATOMIC AND MOLECULAR PHYSICS: Spontaneous Emission of a Polarized Atom in a Medium Between Two Parallel Mirrors  

NASA Astrophysics Data System (ADS)

Using the photon closed orbit theory, the spontaneous emission rate of a polarized atom in a medium between two parallel mirrors is derived and calculated. It is found that the spontaneous emission rate of a polarized atom between the mirrors is related to the atomic position and the polarization direction. The results show that in the vicinity of the mirror, the variation of the spontaneous emission rate depends crucially on the atomic polarization direction. With the increase of the polarization angle, the oscillation in the spontaneous emission rate becomes decreased. For the polarization direction parallel to the mirror plane, the oscillation is the greatest; while for the perpendicular polarization direction, the oscillation is nearly vanished. The agreement between our result and the quantum electrodynamics result suggests the correctness of our calculation. This study further verifies that the atomic spontaneous emission process can be effectively controlled by changing the polarization orientation of the atom.

Wang, De-Hua; Huang, Kai-Yun; Xu, Qiang

2010-01-01

363

ATOMIC AND MOLECULAR PHYSICS: Radiation forces on a three-level atom in the high-order Bessel beams  

NASA Astrophysics Data System (ADS)

The general expressions of the average dissipative and dipole forces acting on a ?-configuration three-level atom in an arbitrary light field are derived by means of the optical Bloch equations based on the atomic density matrix elements, and the general properties of the average dissipative and dipole forces on a three-level atom in the linearly-polarized high-order Bessel beams (HBBs) are analysed. We find a resonant property (with two resonant peaks) of the dissipative force and a non-resonant property (with two pairs of non-resonant peaks) of the dipole force on the three-level atom, which are completely different from those on the two-level atom. Meanwhile we find a saturation effect of the average dissipative force in the HBB, which comes from the saturation of the upper-level population. Our study shows that the general expressions of the average dissipative and dipole forces on the three-level atom will be simplified to those of the two-level atom under the approximation of large detuning. Finally, we study the axial and azimuthal Doppler cooling of atoms in 1D optical molasses composed of two counter-propagating HBBs and discuss the azimuthal influence of the HBB on the Doppler cooling limit. We also find that the Doppler limit of atoms in the molasses HBB is slightly below the conventional Doppler limit of ??(2?B) due to the orbital angular momentum l? of the HBB.

Wang, Zheng-Ling; Yin, Jian-Ping

2008-07-01

364

Performance of Atomic Clocks Flown on the Space Shuttle Experiment NAVEX.  

National Technical Information Service (NTIS)

At the first German Spacelab Mission D1 in autumn 1985 a navigation experiment was flown for seven days on board the NASA Space Shuttle Challenger. Two atomic clocks, one Cs- and one Rb-standard, were part of the spaceborne equipment and were carried back...

H. Nau J. Hammesfahr S. Starker

1987-01-01

365

Atom optical experiments in the drop tower: a pathfinder for space based precision measurements  

Microsoft Academic Search

Recent years have seen much technological progress towards the application of ultra-cold atoms and degenerate quantum gases in future space based precision measurements. A first milestone was achieved by the QUANTUS collaboration with the successful creation of a Bose-Einstein condensate in a freely falling compact drop tower experiment. A next step will now be to demonstrate the feasibility of matter

Sven Herrmann; Andreas Resch; Hauke Müntinga; Claus Laemmerzahl

2010-01-01

366

Precision Physics of Simple Atoms and Constraints on a Light Boson with Ultraweak Coupling  

SciTech Connect

Constraint on spin-dependent and spin-independent Yukawa potential at atomic scale is developed. That covers constraints on a coupling constant of an additional photon {gamma}* and a pseudovector boson. The mass range considered is from 1 eV/c{sup 2} to 1 MeV/c{sup 2}. The strongest constraint on a coupling constant {alpha}{sup '} is at the level of a few parts in 10{sup 13} (for {gamma}*) and below one part in 10{sup 16} (for a pseudovector) corresponding to mass below 1 keV/c{sup 2}. The constraints are derived from low-energy tests of quantum electrodynamics and are based on spectroscopic data on light hydrogenlike atoms and experiments with magnetic moments of leptons and light nuclei.

Karshenboim, S. G. [D. I. Mendeleev Institute for Metrology, St. Petersburg, 190005 (Russian Federation) and Max-Planck-Institut fuer Quantenoptik, Garching, 85748 (Germany)

2010-06-04

367

The effect of atomic mass on the physical spatial resolution in EBSD.  

PubMed

In this study, bicrystals of silver (Ag) and aluminum (Al) were used to investigate the physical spatial resolution of the electron backscatter diffraction system combining a digital image correlation method. Furthermore, the effect of the accelerating voltage and probe current was investigated on the physical spatial resolution of the lateral and longitudinal resolutions for Ag and Al, respectively. The lateral and longitudinal resolutions show high dependency on the accelerating voltage for a low atomic mass material of Al, In addition, these are almost independent of the accelerating voltage for a high atomic mass material of Ag. Moreover, the probe current does not play any role on both the lateral and longitudinal resolutions. The best lateral resolutions for Al and Ag are 40.5 and 12.1 nm at 10 kV and 1 nA, respectively. The best longitudinal resolutions of 23.2 and 80 nm were obtained at 10 kV and 1 nA for Al and Ag, respectively. PMID:23920163

Chen, Delphic; Kuo, Jui-Chao

2013-08-01

368

Oxygen control of atomic structure and physical properties of SrRuO3 surfaces.  

PubMed

Complex oxide thin films and heterostructures have become one of the foci for condensed matter physics research due to a broad variety of properties they exhibit. Similar to the bulk, properties of oxide surfaces can be expected to be strongly affected by oxygen stoichiometry. Here we explore the coupling between atomic structure and physical properties of SrRuO3 (SRO), one of the most well-studied oxide materials. We perform a detailed in situ and ex situ experimental investigation of the surfaces of SRO thin films using a combination of scanning tunneling microscopy (STM), X-ray and ultraviolet photoelectron spectroscopy, SQUID magnetometry, and magnetotransport measurements, as well as ab initio modeling. A number of remarkable linear surface reconstructions were observed by STM and interpreted as oxygen adatoms, favorably adsorbed in a regular rectangular or zigzag patterns. The degree of oxygen coverage and different surface patterns change the work function of the thin films, and modify local electronic and magnetic properties of the topmost atomic layer. The ab initio modeling reveals that oxygen adatoms possess frustrated local spin moments with possible spin-glass behavior of the surface covered by adsorbed oxygen. Additionally, the modeling indicates presence of a pseudo gap on the topmost SrO layer on pristine SrO-terminated surface, suggesting possibility for realization of a surface half-metallic film. PMID:23570268

Tselev, Alexander; Ganesh, P; Qiao, Liang; Siemons, Wolter; Gai, Zheng; Biegalski, Michael D; Baddorf, Arthur P; Kalinin, Sergei V

2013-04-09

369

X-Ray and Inner-Shell Processes: Their Impact on our Understanding of Atomic Physics and Atoms Interacting with Solids  

Microsoft Academic Search

Atomic physics and the basic concepts of quantum theory have been probed in the last fifty years by using the techniques of optics and lasers in the visible range. The new powerful accelerators, storage rings, and various large scale devices, such as ion beams, synchrotron radiation, plasma confinement machines, powerful lasers, etc. developed by the nuclear physicists and high technology

Jean-Pierre Briand

2000-01-01

370

Aspects of the physical chemistry of polymers, biomaterials and mineralised tissues investigated with atomic force microscopy (AFM)  

Microsoft Academic Search

Beyond being merely a tool for measuring surface topography, atomic force microscopy (AFM) has made significant contributions to various scientific areas dealing with physical chemistry processes. This paper presents aspects of the physical chemistry at surfaces and interfaces of polymers, biomaterials and tissues investigated with AFM. Selected examples presented include surface induced self-assembly of polymer blends, copolymer interfacial reinforcement of

Klaus D Jandt; Manuela Finke; Paola Cacciafesta

2000-01-01

371

Advanced Tokamak Physics and the Fusion Ignition Research Experiment (FIRE)  

NASA Astrophysics Data System (ADS)

The advanced tokamak (AT) configuration for magnetic confinement of plasma is considered to have high potential for a viable fusion energy based power plant. The configuration operates at high ? (ratio of kinetic pressure to magnetic pressure) by avoiding and actively stabilizing plasma instabilities, with large self-driven plasma current, (bootstrap current, f_bs), to reduce the need for external current drive, and has plasma particle and energy transport that is roughly consistent with the high ? and high f_bs features. Tokamak experiments continue to develop techniques for producing and controlling these plasmas. Any burning plasma experiment is expected to have the capability to examine such plasmas as part of their experimental mission, and FIRE has made advanced tokamak experiments its highest priority. Analysis has been done to establish the operating space in terms of the plasma current, toroidal field, densities, impurity fractions, ?_N, and fusion gain, all within physics and engineering constraints. Calculations of plasma equilibrium and stability, external current drive from fast waves and lower hybrid waves, and dynamic integrated transport simulations show that advanced tokamak plasmas can be produced and sustained within FIRE's operating limitations. Additional issues for these configurations that are being pursued theoretically and experimentally will be discussed.

Kessel, Charles; Meade, Dale

2003-04-01

372

Initial physics results from the National Spherical Torus Experiment  

NASA Astrophysics Data System (ADS)

The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a~=1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of high harmonic fast wave (HHFW) heating and current drive, 5 MW of neutral beam injection (NBI) and co-axial helicity injection (CHI) for noninductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high ?t and high-bootstrap current fraction, and to develop methods for noninductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA and with a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit, respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 ms was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and ?t=21% were produced.

Kaye, S. M.; Bell, M. G.; Bell, R. E.; Bialek, J.; Bigelow, T.; Bitter, M.; Bonoli, P.; Darrow, D.; Efthimion, P.; Ferron, J.; Fredrickson, E.; Gates, D.; Grisham, L.; Hosea, J.; Johnson, D.; Kaita, R.; Kubota, S.; Kugel, H.; Leblanc, B.; Maingi, R.; Manickam, J.; Mau, T. K.; Maqueda, R. J.; Mazzucato, E.; Menard, J.; Mueller, D.; Nelson, B.; Nishino, N.; Ono, M.; Paoletti, F.; Paul, S.; Peng, Y.-K. M.; Phillips, C. K.; Raman, R.; Ryan, P.; Sabbagh, S. A.; Schaffer, M.; Skinner, C. H.; Stutman, D.; Swain, D.; Synakowski, E.; Takase, Y.; Wilgen, J.; Wilson, J. R.; Zhu, W.; Zweben, S.; Bers, A.; Carter, M.; Deng, B.; Domier, C.; Doyle, E.; Finkenthal, M.; Hill, K.; Jarboe, T.; Jardin, S.; Ji, H.; Lao, L.; Lee, K. C.; Luhmann, N.; Majeski, R.; Medley, S.; Park, H.; Peebles, T.; Pinsker, R. I.; Porter, G.; Ram, A.; Rensink, M.; Rognlien, T.; Stotler, D.; Stratton, B.; Taylor, G.; Wampler, W.; Wurden, G. A.; Xu, X. Q.; Zeng, L.

2001-05-01

373

Physics Potential of a 2540 Km Baseline Superbeam Experiment  

SciTech Connect

We study the physics potential of a neutrino superbeam experiment with a 2540 km baseline. We assume a neutrino beam similar to the NuMI beam in the medium energy configuration. We consider a 100 kton totally active scintillator detector at a 7 mr off-axis location. We find that such a configuration has an outstanding hierarchy discriminating capability. In conjunction with the data from the present reactor neutrino experiments, it can determine the neutrino mass hierarchy at the 3{sigma} level in less than 5 years, if sin{sup 2}2{theta}{sub 13}{>=}0.01, running in the neutrino mode alone. As a stand alone experiment, with a 5 year neutrino run and a 5 year anti-neutrino run, it can determine non-zero {theta}{sub 13} at the 3{sigma} level if sin{sup 2} 2{theta}{sub 13}{>=}7x10{sup -3} and hierarchy at the 3{sigma} level if sin{sup 2}2{theta}{sub 13}{>=}8x10{sup -3}. This data can also distinguish {delta}{sub CP} = {pi}/2 from the CP conserving values of 0 and {pi}, for sin{sup 2}2{theta}{sub 13}{>=}0.02.

Joglekar, Aniket [Department of Physics, Indian Institute of Technology Bombay, Mumbai (India); Address after August 1, 2010 Department of Physics, University of Chicago, Chicago, IL (United States); Prakash, Suprabh; Raut, Sushant K.; Sankar, S. Uma [Department of Physics, Indian Institute of Technology Bombay, Mumbai (India)

2011-10-06

374

Physics results from the National Spherical Torus Experiment  

SciTech Connect

The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a {approx} 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI), and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-{beta}{sub t} and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA, stored energies up to 55 kJ, {beta}{sub t} {approx} 10%, and a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and {beta}{sub t}=21% were produced.

Kaye, S.; Bell, M. [and others

2000-11-01

375

Initial Physics Results From the National Spherical Torus Experiment  

SciTech Connect

The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a approximately equal to 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI) and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-bt and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA and with a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and bt =21% were produced.

Kaye, S.M.; Bell, M.G.; Bell, R.E.; Bialek, J. [and others

2001-01-03

376

Virtual experiments, physical validation: dental morphology at the intersection of experiment and theory.  

PubMed

Computational models such as finite-element analysis offer biologists a means of exploring the structural mechanics of biological systems that cannot be directly observed. Validated against experimental data, a model can be manipulated to perform virtual experiments, testing variables that are hard to control in physical experiments. The relationship between tooth form and the ability to break down prey is key to understanding the evolution of dentition. Recent experimental work has quantified how tooth shape promotes fracture in biological materials. We present a validated finite-element model derived from physical compression experiments. The model shows close agreement with strain patterns observed in photoelastic test materials and reaction forces measured during these experiments. We use the model to measure strain energy within the test material when different tooth shapes are used. Results show that notched blades deform materials for less strain energy cost than straight blades, giving insights into the energetic relationship between tooth form and prey materials. We identify a hypothetical 'optimal' blade angle that minimizes strain energy costs and test alternative prey materials via virtual experiments. Using experimental data and computational models offers an integrative approach to understand the mechanics of tooth morphology. PMID:22399789

Anderson, P S L; Rayfield, E J

2012-03-07

377

ATOMIC AND MOLECULAR PHYSICS: Interference effects on the photoionization cross sections between two neighbouring atoms: nitrogen as an example  

NASA Astrophysics Data System (ADS)

Interference effects on the photoionization cross sections between two neighbouring atoms are considered based on the coherent scattering of the ionized electrons by the two nuclei when their separation is less than or comparable to the de Broglie wave length of the ionized electrons. As an example, the single atomic nitrogen ionization cross section and the total cross sections of two nitrogen atoms with coherently added photoionization amplitudes are calculated from the threshold to about 60 Å (1 Å = 0.1 nm) of the photon energy. The photoionization cross sections of atomic nitrogen are obtained by using the close-coupling R-matrix method. In the calculation 19 states are included. The ionization energy of the atomic nitrogen and the photoionization cross sections agree well with the experimental results. Based on the R-matrix results of atomic nitrogen, the interference effects between two neighbouring nitrogen atoms are obtained. It is shown that the interference effects are considerable when electrons are ionized just above the threshold, even for the separations between the two atoms are larger than two times of the bond length of N2 molecules. Therefore, in hot and dense samples, effects caused by the coherent interference between the neighbours are expected to be observable for the total photoionization cross sections.

Wu, Jian-Hua; Yuan, Jian-Min

2009-12-01

378

Results on QCD Physics from the CDF-II Experiment  

SciTech Connect

In this paper the authors review a selection of recent results obtained, in the area of QCD physics, from the CDF-II experiment that studies p{bar p} collisions at {radical}s = 1.96 TeV provided by the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the Tevatron Run II data samples. In particular they will illustrate the progress achieved and the status of the studies on the following QCD processes: jet inclusive production, using different jet clustering algorithm, W({yields} e{nu}{sub e}) + jets and Z({yields} e{sup +}e{sup -}) + jets production, {gamma} + b-jet production, dijet production in double pomeron exchange and finally exclusive e{sup +}e{sup -} and {gamma}{gamma} production. No deviations from the Standard Model have been observed so far.

Pagliarone, C.; /Cassino U. /INFN, Pisa

2006-12-01

379

ATOMIC AND MOLECULAR PHYSICS: Elastic Collisions Between two Ground-State P and D Atoms at Low and Ultralow Temperatures  

NASA Astrophysics Data System (ADS)

The PD(X3?-) interaction potential is constructed using the CCSD(T) theory and the basis set, aug-cc-pV5Z. Using this potential, the spectroscopic parameters are accurately determined. The present Do, De, Re, ?e, ?e?e, ?e, and Be are of 3.056 99 eV, 3.161 75 eV, 0.142 39 nm, 1701.558 cm-1, 23.6583 cm-1, 0.085 99 cm-1, and 4.3963 cm-1, respectively, which almost perfectly conform with the measurements. A total of 26 vibrational states is predicted when J = 0 by solving the radial Schrödinger equation of nuclear motion. The complete vibrational levels, classical turning points, initial rotation and centrifugal distortion constants when J = 0 are reported for the first time, which favorably agree with the experiments. The total and various partial-wave cross sections are calculated for the elastic impact between two ground-state P and D atoms at 1.0 × 10-12 - 1.0 × 10-4 a.u. when they approach each other along the PD(X3?-) potential. No shape resonances exist in the total elastic cross sections, though the peaks can be found for each partial wave until l = 6. The shape of the total elastic cross sections is dominated by the s partial wave at very low temperatures. Due to the weakness of the shape resonances of each partial wave, they are all passed into oblivion by the strong total elastic cross sections.

Shi, De-Heng; Zhang, Jin-Ping; Sun, Jin-Feng; Ma, Heng; Liu, Yu-Fang; Zhu, Zun-Lue

2010-02-01

380

Optimizing liner implosions for high energy density physics experiments  

SciTech Connect

Cylindrical metal shells imploded by magnetic fields - liners - are used as kinetic energy drivers for high energy density physics experiments in hydrodynamics and dynamic material property measurements. There are at least three ways in which liners have been, or are expected to be, used to produce high energy density, i.e., high pressure, in target materials. A common approach uses the liner as a convergent flyer plate, which impacts a material target cylinder after having been shocklessly accelerated across an intervening gap. The resultant shock and piston hydrodynamic flow in the target are used in exploration of a wide variety of phenomena and material properties. Another common method is to slowly compress a liner containing a material sample in a such fashion that little heating occurs. This technique is most useful for investigated physical properties at low temperature and extreme density. Finally, one can use a hybrid approach to shock heat with an impacting liner followed by slower adiabatic, if not isentropic, compression to explore material properties in extrema. The magnetic fields for driving these liners may be produced by either high explosive pulsed power generators or by capacitor banks. Here we will consider only capacitor banks.

Ekdahl, C. [Los Alamos National Lab., NM (United States); Humphries, S. Jr. [Univ. of New Mexico, Albuquerque, NM (United States)

1996-12-31

381

Power supplies and quench protection for the Tokamak Physics Experiment  

SciTech Connect

The Tokamak Physics Experiment (TPX) is an advanced tokamak project aimed at the production of quasi-steady state plasmas with advanced shape, heating, and particle control. TPX is to be built at the Princeton Plasma Physics Laboratory (PPPL) using many of the facilities from the Tokamak Fusion Test Reactor (TFTR). First plasma is scheduled for the year 2000. TPX will be the first tokamak to utilize superconducting (SC) magnets in both the toroidal field (TF) and poloidal field (PF) systems. This is a new feature which requires not only a departure from the traditional tokamak power supply schemes but also that ultra-reliable quench protection devices be used to rapidly discharge the stored energy from the magnets in the event of a quench. This paper describes the plan and basis for the adaptation and augmentation of the PPPL/TFTR power system facilities to supply TPX. Following a description of the basic operational requirements, four major areas are addressed, namely the AC power system, the TF power supply, the PF power supply, and quench protection for the TF and PF systems.

Neumeyer, C.L. [Raytheon Engineers & Constructors, Princeton, NJ (United States). EBASCO Div.

1994-07-01

382

Dynamical stabilization of atoms in intense laser pulses accessible to experiment  

NASA Astrophysics Data System (ADS)

We analyze the excitation of atoms by intense pulsed laser fields and describe a mechanism leading to effective dynamical stabilization at a photon energy below the unperturbed binding energy. At low and intermediate intensities, the atom is left in a coherent superposition of the initial state and a set of Rydberg states which is stable against ionization; this effect subsists for pulse durations presently accessible to experiment. At higher intensities, population is transferred through degenerate Raman coupling to Rydberg states of higher angular momentum.

Huens, Etienne; Piraux, Bernard

1993-02-01

383

ATOMIC AND MOLECULAR PHYSICS: Energy spectrum and superfluidity of spin-2 ultracold bosons in optical lattices  

NASA Astrophysics Data System (ADS)

This paper studies the superfluidity of ultracold spin-2 Bose atoms with weak interactions in optical lattices by calculating the excitation energy spectrum using the Bogoliubov approach. The energy spectra exhibit the characteristics of the superfluid-phase explicitly and it finds the nonvanishing critical speeds of superfluid. The obtained results display that the critical speeds of superfluid are different for five spin components and can be controlled by adjusting the lattice parameters in experiments. Finally it discusses the feasibilities of implementing and measuring superfluid.

Wang, Yong-Jun; Liu, Xian-Feng; Han, Jiu-Rong

2009-12-01

384

Nuclear effects in atomic transitions  

Microsoft Academic Search

Atomic electrons are sensitive to the properties of the nucleus they are bound to, such as nuclear mass, charge distribution, spin, magnetization distribution, or even excited level scheme. These nuclear parameters are reflected in the atomic transition energies. A very precise determination of atomic spectra may thus reveal information about the nucleus, otherwise hardly accessible via nuclear physics experiments. This

Adriana Palffy

2010-01-01

385

ATOMIC AND MOLECULAR PHYSICS: Variation of photoabsorption cross section of atomic silver from isolated to condensed conditions  

NASA Astrophysics Data System (ADS)

The influence of the local-field on the photoabsorption cross section of the atomic silver is studied in detail by using the Clausius-Mossotti (CM) model and the Onsager model separately. The variations of the photoabsorption cross section of atomic silver with number density and radius of the environmental interaction cavity are studied systematically by using more general expressions for the photoabsorption cross sections, proposed by Sun et al recently. It has proved to be reasonable to model the optical response properties of bulky material by coupling the property of isolated atom with the environmental effects in the present work.

Ma, Xiao-Guang; Gong, Yu-Bing; Qu, Zhao-Jun

2009-04-01

386

ATOMIC AND MOLECULAR PHYSICS: Multiphoton ionization of the hydrogen atom exposed to circularly or linearly polarized laser pulses  

NASA Astrophysics Data System (ADS)

This paper studies the multiphoton ionization of the hydrogen atom exposed to the linearly or circularly polarized laser pulses by solving the time-dependent Schrödinger equation. It finds that the ratio of the ionization probabilities by linearly and circularly polarized laser pulses varies with the numbers of absorbing photons. With the same laser intensity, the circularly polarized laser pulse favors to ionize the atom with more ease than the linearly polarized laser pulse if only two or three photons are necessary to be absorbed. For the higher order multiphoton ionization, the linearly polarized laser pulse has the advantage over circularly polarized laser pulse to ionize the atom.

Wang, Pei-Jie; He, Feng

2009-12-01

387

Atomic physics and quantum optics using superconducting circuits: from the Dynamical Casimir effect to Majorana fermions  

NASA Astrophysics Data System (ADS)

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).

Nori, Franco

2012-02-01

388

ATOMIC AND MOLECULAR PHYSICS: Scaled-energy spectroscopy of a |M| = 1 Rydberg barium atom in an electric field  

NASA Astrophysics Data System (ADS)

We observe strong energy-dependent quantum defects in the scaled-energy Stark spectra for |M| = 1 Rydberg states of barium atoms at three scaled energies: ? = -2.000, ? = -2.500 and ? = -3.000. In an attempt to explain the observations, theoretical calculations of closed orbit theory based on a model potential including core effect are performed for non-hydrogenic atoms. While such a potential has been uniformly successful for alkali atoms with a single valence electron, it fails to match experimental results for barium atoms in the 6snp Rydberg states with two valence electrons. Our study points out that this discrepancy is due to the strong perturbation from the 5d8p state, which voids the simple approximation for constant quantum defects of principle quantum number n.

Wang, Lei; Quan, Wei; Shen, Li; Yang, Hai-Feng; Shi, Ting-Yun; Liu, Xiao-Jun; Liu, Hong-Ping; Zhan, Ming-Sheng

2009-11-01

389

Geant4 applications and developments for medical physics experiments  

Microsoft Academic Search

The Geant4 Monte Carlo radiation transport toolkit provides the basic services and infrastructure required for the development of flexible simulation frameworks and applications, which have found generalized use in high energy physics, nuclear physics, astrophysics, and medical physics research. Object-oriented design provides the possibility to implement or modify any physics process in Geant4 without changing other parts of the code.

Pedro Rodrigues; Rui Moura; Catarina Ortigão; Luís Peralta; Maria Grazia Pia; Andreia Trindade; João Varela

2004-01-01

390

The AMS Measurements and Its Applications in Nuclear Physics at China Institute of Atomic Energy (CIAE)  

SciTech Connect

Accelerator Mass Spectrometry (AMS), initiated in late 1970s at McMaster university based on the accelerator and detector technique, has long been applied in the studies on archaeology, geology, and cosmology, as a powerful tool for isotope dating. The advantages of AMS in the analysis of rare nuclides by direct counting of the atoms, small sample size and relatively free from the interferences of molecular ions have been well documented. This paper emphasizes that AMS can not only be used for archaeology, geology, environment, biology and so on, but also served as a unique tool for nuclear physics research. In this paper, the determination of the half-lives of {sup 79}Se, the measurements of the cross-sections of {sup 93}Nb(n,2n){sup 92g}Nb and {sup 238}U(n,3n){sup 236}U reactions, the detection and determination of ultratrace impurities in neutrino detector materials, and the measurement of the fission product nuclide {sup 126}Sn, are to be introduced, as some of examples of AMS applications in nuclear research conducted in AMS lab of China Institute of Atomic Energy. Searching for superheavy nuclides by using AMS is being planned.

Jiang Shan; Shen Hongtao; He Ming; Dong Kejun; He Guozhu; Wang Xianggao; Yuan Jian; Wang Wei; Wu Shaoyong [China Institute of Atomic Energy, P.O.Box 275-80, Beijing 102413 (China); Ruan Xiangdong; Wu Weimin [College of Physics, Guangxi University, Nanning 530004 (China)

2010-05-12

391

ATOMIC PHYSICS PROCESSES IMPORTANT TO THE UNDERSTANDING OF THE SCRAPE-OFF LAYER OF TOKAMAKS  

SciTech Connect

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.

WEST, W.P.; GOLDSMITH,; B. EVANS,T.E.; OLSON, R.J.

2002-05-01

392

The Basic Physics of Electron-Atom Collisions: How Much Do We Know and How Much Is Left to Learn?  

Microsoft Academic Search

Electron-atom scattering is perhaps the most investigated quantum mechanical process in physics, but not the best understood. Indeed, the simplest example of this process, electron-hydrogen scattering, has only just recently succumbed to comprehensive solution. Given that we believe in Quantum Mechanics, Special Relativity, and Coulomb's Law, what makes electron-atom scattering so difficult to understand? This talk will present a review

T. J. Gay

2001-01-01

393

Performance of the High-Resolution Beamline for Atomic and Molecular Physics at the Advanced Light Source  

NASA Astrophysics Data System (ADS)

Beamline 9.0.1 at the Advanced Light Source provides an intense photon beam with high spectral resolution and is well suited for a variety of experiments in atomic and molecular physics. The high brightness synchrotron source, 4.5 m long undulator and high quality spherical grating monochromator are all critical to the high perfomance of the beamline. The accessible photon energy range covers 20 to 300 eV with approximately 10^12 photons per second with a bandwidth of one part in 10,000. The resolution--flux ratio can be varied to meet the demands of the experiment. Very high resolution spectra of the He double excitation resonances have recently been obtained, for example,(G. Kaindl, K. Schulz, J.D. Bozek, P.A. Heimann and A.S. Schlachter, Synchrotron Radiation News, 8), 29 (1995). using slit widths of <5 ? m. Examples of high resolution photoionization, ion yield and photoelectron spectra measured using beamline 9.0.1 will be presented.

Bozek, J. D.; Heimann, P. A.

1996-05-01

394

Electron electric-dipole-moment experiment using electric-field quantized slow cesium atoms  

SciTech Connect

A proof-of-principle electron electric-dipole-moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric-field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal |m{sub F}| and, along with the low ({approx_equal}3 m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger, Charles T. Jr.; Gould, Harvey [Mail Stop 71-259, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2007-06-15

395

The MOeLLER experiment at Jefferson Lab: search for physics beyond the Standard Model  

SciTech Connect

The MOeLLER experiment at Jefferson Lab will measure the parity-violating analyzing power A{sub z} in the scattering of 11 GeV longitudinally polarized electrons from the atomic electrons in a liquid hydrogen target (Moeller scattering). In the Standard Model a non-zero A{sub z} is due to the interference of the electromagnetic amplitude and the weak neutral current amplitude, the latter mediated by the Z{sup 0} boson. A{sub z} is predicted to be 35.6 parts per billion (ppb) at the kinematics of the experiment. It is the objective of the experiment to measure A{sub z} to a precision of 0.73 ppb. This result would yield a measurement of the weak charge of the electron Q{sub W}{sup e} to a fractional error of 2.3% at an average value Q{sup 2} of 0.0056 (GeV/c){sup 2}. This in turn will yield a determination of the weak mixing angle sin{sup 2{theta}}w with an uncertainty of {+-}0.00026(stat) {+-}0.00013(syst), comparable to the accuracy of the two best determinations at high energy colliders (at the Z{sup 0} pole). Consequently, the result could potentially influence the central value of this fundamental electroweak parameter, which is of critical importance in deciphering any signal of new physics that might be observed at the Large Hadron Collider (LHC). The measurement is sensitive to the interference of the electromagnetic amplitude with new neutral current amplitudes as weak as 10{sup -3} GF from as yet unknown high energy dynamics, a level of sensitivity unlikely to be matched in any experiment measuring a flavor and CP conserving process in the next decade. This provides indirect access to new physics at multi-TeV scales in a manner complementary to direct searches at the LHC.

Oers, Willem T. H. van [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada) and Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)

2010-07-27

396

Theory of Spin-Orbit Coupling in Atoms. II. Comparison of Theory with Experiment  

Microsoft Academic Search

Results of calculations of the spin-orbit coupling constant for 2p, 3p, 4p, and 3d shell ions and atoms are presented. The calculations are based on a theory developed in a previous paper. Excellent agreement of this theory with experiment is obtained for the 2p and 3d shell ions, while calculations using the familiar expression for the coupling constant lie 10

M. Blume; R. E. Watson

1963-01-01

397

ATOMIC AND MOLECULAR PHYSICS: Model Potential Calculations of Oscillator Strength Spectra of Rydberg Li Atoms in External Fields  

NASA Astrophysics Data System (ADS)

By combining the B-spline basis set with model potential (B-spline + MP), we present oscillator strength spectra of Rydberg Li atoms in external fields. The photoabsorption spectra are analyzed. Over the narrow energy ranges considered in this paper, the structure of the spectra can be independent of the initial state chosen for a given atom. Our results are in good agreement with previous high-precision experimental data and theoretical calculations, where the R-matrix approach together with multichannel quantum defect theory (R-matrix+MQDT) was used. It is suggested that the present methods can be applied to deal with the oscillator strength spectra of Rydberg atoms in crossed electric and magnetic fields.

Meng, Hui-Yan; Shi, Ting-Yun

2009-08-01

398

Competing atomic processes in Ba and Sr injection critical velocity experiments  

NASA Astrophysics Data System (ADS)

The critical ionization velocity effect requires a superthermal electron population to ionize through collisional impact. Such superthermal electrons can however lose energy to competing atomic processes, as well as to ionization, thus limiting the efficiency of the effect. Considering Ba and Sr magnetospheric injection experiments designed to test the CIV theory, it is found that in both cases roughly 60 percent of the superthermal electron energy is lost on exciting line radiation. Moreover, energy loss to background neutral oxygen places a strict limit on the injected cloud densities for which critical velocity effects are possible; a finding which explains the consistently negative results in radial injection experiments.

Newell, P. T.; Torbert, R. B.

1985-12-01

399

GEANT4 applications and developments for medical physics experiments  

Microsoft Academic Search

The GEANT4 Monte Carlo radiation transport toolkit provides the basic services and infrastructure required for the development of flexible simulation frameworks and applications which have found generalized use in high energy physics, nuclear physics, astrophysics and medical physics research. GEANT4 object-oriented design provides the possibility to implement or modify any physics process in GEANT4 without changing other parts of the

Pedro Rodrigues; Rui Moura; L. Peralta; M. G. Pia; A. Trindade; J. Varela

2003-01-01

400

The Spheromak Turbulence Experiment: The Next Phase in Spheromak Physics  

NASA Astrophysics Data System (ADS)

The spheromak turbulence experiment (STPX) is a collaboration between FAMU, WVU, Auburn University, and Woodruff Scientific, Inc. The fundamental purpose of STPX is to advance Spheromak physics toward producing a burning plasma and new insights on astrophysical systems with magnetic reconnection. FAMU will employ microwave pulses to manipulate the stable state. In addition, closely coupled NIMROD modeling and experimentation will take place using the FAMU computational cluster. Auburn University is providing a pair of movable probe arrays consisting of a triple probe and a series of four saturation current/floating potential probes for making instantaneous measurements of plasma parameters. West Virginia University is providing an array of (N), X-MHz, B-dot coils for making measurements of magnetic fluctuations. West Virginia University is also providing an array of 25, 2 MHz bandwidth, B-dot coils and differential amplifiers for making high time-resolution measurements of magnetic fluctuations at the edge of the plasma. Woodruff Scientific designed and constructed the STPX vessel.

Mezonlin, Ephrem; Williams, Kyron; Weatherford, C. A.; Johnson, J. A., III; Alexander, A. B.; Scime, Earl; Keesee, A.; Lusk, G.; Reynolds, E.; Vandervort, R.; Arnold, N. I.; Gilmore, K.; Thomas, E., Jr.; Woodruff, Simon

2011-11-01

401

Advantages and limitations of LSO scintillator in nuclear physics experiments  

SciTech Connect

Light yield, light pulse shape due to {gamma}-rays and {alpha}-particles, energy and time resolutions for three different samples of the LSO scintillator were studied using an XP2020Q photomultiplier and an S3590-03 photodiode. Light yields of 4,200{+-}200 phe/MeV and 18,500{+-}900 e-h pair/MeV were measured for the PM tube and the photodiode, respectively. The light pulse shape exhibits a pure exponential decay with a time constant of 47.2{+-}1.3 ns for both {gamma}-rays and {alpha}-particles. Energy resolutions of 10% and 14.6% for the 662 keV {gamma}-rays from a {sup 137}Cs source were obtained for the photomultiplier and the photodiode readout, respectively. A time resolution of 180 ns was observed for {sup 60}Co {gamma}-rays at 1 MeV threshold and 400 ps for 100 keV threshold. The study confirmed a number of advantages of the LSO scintillator for nuclear physics experiments, however, for small size samples. For larger volumes the natural radioactivity of the LSO, about 300 counts/s/cm{sup 3}, may limit possible applications. The high number of e-h pair produced in the photodiodes makes LSO very attractive for small compact scintillation probes.

Ludziejewski, T.; Moszynska, K.; Moszynski, M.; Wolski, D. [Soltan Institute for Nuclear Studies, Swierk-Otwock (Poland); Klamra, W.; Norlin, L.O. [Royal Institute of Technology, Stockholm (Sweden). Dept. of Physics; Devitsin, E.; Kozlov, V. [Lebedev Physical Institute, Moscow (Russian Federation)

1995-08-01

402

Lower hybrid system design for the Tokamak physics experiment  

SciTech Connect

The lower hybrid (LH) launcher configuration has been redesigned to integrate the functions of the vertical four-way power splitter and the front waveguide array (front array). This permits 256 waveguide channels to be fed by only 64 waveguides at the vacuum window interface. The resulting configuration is a more compact coupler, which incorporates the simplicity of a multijunction coupler while preserving the spectral flexibility of a conventional lower hybrid launcher. Other spin-offs of the redesign are reduction in thermal incompatibility between the front array and vacuum windows, improved maintainability, in situ vacuum window replacement, a reduced number of radio frequency (rf) connections, and a weight reduction of 7300 kg. There should be a significant cost reduction as well. Issues associated with the launcher design and fabrication have been addressed by a research and development program that includes brazing of the front array and testing of the power splitter configuration to confirm that phase errors due to reflections in the shorted splitter legs will not significantly impact the rf spectrum. The Conceptual Design Review requires that radiation levels at the torus radial port mounting flange and outer surface of the toroidal field coils should be sufficiently low to permit hands-on maintenance. Low activation materials and neutron shielding are incorporated in the launcher design to meet these requirements. The launcher is configured to couple 3 MW of steady state LH heating/LH current drive power at 3.7 GHz to the Tokamak Physics Experiment plasma.

Goranson, P.L.; Conner, D.L.; Swain, D.W.; Yugo, J.J. [Oak Ridge National Lab., TN (United States); Bernabei, S.; Greenough, N. [Princeton Univ., NJ (United States). Plasma Physics Lab.

1995-12-31

403

Experiences developing ALEGRA: A C++ coupled physics framework  

SciTech Connect

ALEGRA is a coupled physics framework originally written to simulate inertial confinement fusion (ICF) experiments being conducted at the PBFA-II facility at Sandia National Laboratories. It has since grown into a large software development project supporting a number of computational programs at Sandia. As the project has grown, so has the development team, from the original two authors to a group of over fifteen programmers crossing several departments. In addition, ALEGRA now runs on a wide variety of platforms, from large PCs to the ASCI Teraflops massively parallel supercomputer. The authors discuss the reasons for ALEGRA`s success, which include the intelligent use of object-oriented techniques and the choice of C++ as the programming language. They argue that the intelligent use of development tools, such as build tools (e.g. make), compiler, debugging environment (e.g. dbx), version control system (e.g. cvs), and bug management software (e.g. ClearDDTS), is nearly as important as the choice of language and paradigm.

Budge, K.G.; Peery, J.S.

1998-11-01

404

Physics Design of the National Compact Stellarator Experiment  

SciTech Connect

Compact quasi-axisymmetric stellarators offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio approximately 4.4 and average elongation approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for b > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at b = 4% (the rest is from the coils). Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties.

G.H. Neilson; M.C. Zarnstorff; J.F. Lyon; the NCSX Team

2002-02-21

405

Quench Detection and Instrumentation for the Tokamak Physics Experiment magnets  

SciTech Connect

The design of the Local Instrumentation & Control (I&C) System for the Tokamak Physics Experiment (TPX) superconducting PF & TF magnets is presented. The local I&C system monitors the status of the magnet systems and initiates the proper control sequences to protect the magnets from any foreseeable fault. Local I&C also stores magnet-system data for analysis and archiving. Quench Detection for the TPX magnets must use a minimum of two independent sensing methods and is allowed a detection time of one second. Proposed detection methods include the measurement of; (1) normal-zone resistive voltage, (2) cooling-path helium flow, (3) local temperature in the winding pack, (4) local pressure in the winding pack. Fiber-optic based isolation systems are used to remove high common-mode magnet voltages and eliminate ground loops. The data acquisition and fault-detection systems are computer based. The design of the local I&C system incorporates redundant, fault-tolerant, and/or fail-safe features at all component levels. As part of a quench detection R&D plan, a Quench Detection Model Coil has been proposed to test all detection methods. Initial cost estimates and schedule for the local I&C system are presented.

Chaplin, M.R.; Hassenzahl, W.V. [Lawrence Livermore National Lab., CA (United States); Schultz, J.H. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

1993-10-06

406

The cryogenic helium cooling system for the Tokamak physics experiment  

SciTech Connect

The Tokamak Physics Experiment (TPX) will use supercritical helium to cool all the magnets and supply helium to the Vacuum cryopumping subsystem. The heat loads will come from the standard steady state conduction and thermal radiation sources and from the pulsed loads of the nuclear and eddy currents caused by the Central Solenoid Coils and the plasma positioning coils. The operations of the TPX will begin with pulses of up to 1000 seconds in duration every 75 minutes. The helium system utilizes a pulse load leveling scheme to buffer out the effects of the pulse load and maintain a constant cryogenic plant operation. The pulse load leveling scheme utilizes the thermal mass of liquid and gaseous helium stored in a remote dewar to absorb the pulses of the tokamak loads. The mass of the stored helium will buffer out the temperature pulses allowing 5 K helium to be delivered to the magnets throughout the length of the pulse. The temperature of the dewar will remain below 5 K with all the energy of the pulse absorbed. This paper will present the details of the heat load sources, of the pulse load leveling scheme operations, a partial helium schematic, dewar temperature as a function of time, the heat load sources as a function of time and the helium temperature as a function of length along the various components that will be cooled.

Felker, B.; Slack, D.S.; Wendland, C.R.

1995-09-29

407

Automated computer vision interpretation for physical and genetic mapping experiments  

SciTech Connect

Much of the high-throughput data currently generated in the molecular genetics laboratory is in the form of two dimensional images. In physical mapping, a high-density gridded filter containing thousands YACs or cosmids can be hybridized against a single labeled probe, such as the IRS-PCR products of a radiation hybrid (RH). In genetic mapping, hundreds of polymorphic dinucleotide repeat PCR experiments can be multiplexed into distinct lanes, size ranges, and fluorescent colors on a single run of an Applied Biosystems (ABl) 373A automated DNA sequencer. For all its advantages such high-throughput data introduces a new fundamental bottleneck: the greatly increased time, expense, and error of scoring these assays when relying solely on the human visual system. Toward this end, we have developed a novel computer vision automation architecture that addresses the needs of high-throughput data interpretation in the molecular genetics laboratory. A flexible knowledge-based approach is used to systematically detect and analyze signal features, motivated by how human experts perform the interpretation. This architecture enables customization to similar hybridization-and gel-based tasks. Our prototype system has thus far been tested on both hybridization data and ABl gel images.

Pathak, D.K.; Perlin, M.W. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1994-09-01

408

The physics of non-Newtonian liquid slurry atomization. Part 2: Twin-fluid atomization of non-Newtonian liquids -- First quarterly technical report, 1 January--31 March 1994  

SciTech Connect

The changes in the physical processes of atomization as a result of adding a high molecular weight polymer in low concentrations to liquid have been studied. Both Newtonian and non-Newtonian liquids were investigated with particular emphasis on the non-Newtonian rheological characteristics. It was found that viscoelastic liquids are much more difficult to atomize than viscoinelastic liquids. Viscoinelastic liquids showed a breakup behavior similar to that of water sprays. Viscoelastic materials showed remarkably different breakup patterns. The ligaments were seen to undergo a very large stretching motion before they breakup, resulting in long threads of liquid attached to droplets. The normal stresses developed in viscoelastic materials are much higher than their associated shear stresses. Consequently, the development of the large normal stresses appears to be the most important rheological mechanism that inhibits breakup. The non-Newtonian liquids selected for the experiment were aqueous solutions of Xanthan gum and Polyacrylamide E10.

Mansour, A.; Chigier, N.

1994-06-01

409

Berry phases for quadratic spin Hamiltonians taken from atomic and solid state physics: examples of Abelian gauge fields not connected to physical particles  

Microsoft Academic Search

This paper contains an evaluation of the Berry phases associated with the following class of nonlinear spin Hamiltonians : H (B, n ) = 03B3S S · B + 03B3Q((S · n)2 - S2\\/3), with B · n = 0. Examples of these Hamiltonians are given in Atomic and Solid State Physics. We compute exactly the Berry phases for S

C. Bouchiat

1989-01-01

410

ATOMIC AND MOLECULAR PHYSICS: Directly Trapping Atoms in a U-Shaped Magneto-Optical Trap Using a Mini Atom Chip  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate the trapping of 85Rb atoms directly on a chip-size U-shaped magneto-optical trap (U-MOT). The trap includes a U-shaped wire on the chip, two bias magnetic field coils and laser beams. The capture volume of the U-MOT is theoretically calculated, and the trap is experimentally realized. With 2 A current applied to the U-shaped wire and 2-Gauss horizontal bias field, more than 2 × 106 atoms are trapped. In contrast with an ordinary mirror-MOT, this U-MOT captures atoms directly from the background, thus the trap size is greatly reduced. Based on this mini trap scheme, it is possible to realize a chip-size atom trap array for quantum information processing.

Yan, Hui; Yang, Guo-Qing; Wang, Jin; Zhan, Ming-Sheng

2008-09-01

411

The use of cylindrical lenses in easy experiments for physics education and the magic arts  

Microsoft Academic Search

The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by staging tricks, effects or illusions

Stanislaw Bednarek; Jerzy Krysiak

2011-01-01

412

The Use of Cylindrical Lenses in Easy Experiments for Physics Education and the Magic Arts  

ERIC Educational Resources Information Center

|The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by…

Bednarek, Stanislaw; Krysiak, Jerzy

2011-01-01

413

Focal plane array based infrared thermography in fine physical experiment  

NASA Astrophysics Data System (ADS)

By two examples of dissimilar physical phenomena causing thermophysical effects, the unique capabilities of one of the up-to-date methods of experimental physics—focal plane array (FPA) based infrared (IR) thermography (IRT), are demonstrated distinctly. Experimenters inexperienced in IRT can grasp how this method provides a means for combining real-time visualization with quantitative analysis. A narrow-band short-wavelength IR camera was used in the experiments. It is discussed and stated that IRT is best matched and suited to the next two test conditions—when a heated specimen is thin and when heat is generated in the immediate region of a surface of a solid. The first prerequisite is realized in the search for directional patterns of combined low-power radiation sources with the use of the IRT-aided method. The second one is realized in studies of water vapour adsorption on uneven (irregular) surfaces of solid materials. With multiple swatches taken from a set of different fabrics and used as experimental samples, a sharp distinction between adsorptivities of their surfaces is strikingly illustrated by IRT time-domain measurements exhibiting the associated thermal effect ranging within an order of magnitude. It is justified that the described IRT-aided test can find practical implementation at least in the light industry. Emissivities of different fabrics are evaluated experimentally with the described reflection method based on the narrow spectral range of IRT. On the basis of direct IR observations, attention is paid to the need for close control over the surface temperature increase while the adsorption isotherms are being measured. Sensitivity of the FPA-based IRT method, as applied to examine the kinetics of initial stages of adsorption of gaseous molecules on the solid surface, is evaluated analytically and quantitatively. The relationship between the amount of adsorbate and the measurable excess of adsorbent temperature is found. It is discovered that the method makes it possible to control nano-quantities of the adsorbed matter, namely, it is sensitive to an incipient molecular film of 1/300-monolayer effective thickness.

Vainer, Boris G.

2008-03-01

414

Ionization resonances for H atoms in a strong (static + microwave) field: Experiment vs.theory  

NASA Astrophysics Data System (ADS)

Following up onfootnote E. Galvez et al., previous abstract, this meeting, take, e.g., H(n_0=40) atoms in collinear static and 8.105 GHz fields (amplitudes Fs and F_?, respectively). At F_? = 220 V/cm (n_0^4F_?=0.110) the survival probability P_surv decreases sharply at Fs ~= k \\cdot 50 V/cm, k=1,ldots,5. Raising F_? from zero, higher- (lower-)k resonances first appear at lower (higher) F_?. A given resonance disappears at certain F_?. Though in linear Stark effect approximation (LSEA) k ? = 3n_0Fs (in a.u.) gives energy matching for the splitting between same-|m|, adjacent Stark substates at k \\cdot 52.8 V/cm, this cannot explain these (multiphoton) resonances because in LSEA the transition matrix element is zero. (Finite quantum defects affected matrix elements in previous alkali atom experimentsfootnote T.F. Gallagher, Rydberg Atoms (CUP, Cambridge, 1994), Chap. 10.) Numerical simulations based on classical dynamics reproduce all distinctive features of the (F_? + F_s) resonances data with 3d H atoms. Classically and quantally we use an adiabatic model to view the dynamics as a case of parametric resonance. We explain the disappearance of the resonances and achieve quantitative agreement with experiment.

Koch, P.; Richards, D.; Galvez, E.; Zelazny, S.

1998-05-01

415

Plasma diagnostics for the sustained spheromak physics experiment  

SciTech Connect

In this article we present an overview of the plasma diagnostics operating or planned for the sustained spheromak physics experiment device now operating at Lawrence Livermore National Laboratory. A set of 46 wall-mounted magnetic probes provide the essential data necessary for magnetic reconstruction of the Taylor relaxed state. Rogowski coils measure currents induced in the flux conserver. A CO{sub 2} laser interferometer is used to measure electron line density. Spectroscopic measurements include an absolutely-calibrated spectrometer recording extended domain spectrometer for obtaining time-integrated visible ultraviolet spectra and two time-resolved vacuum monochrometers for studying the time evolution of two separate emission lines. Another time-integrated spectrometer records spectra in the visible range. Filtered silicon photodiode bolometers provide total power measurements, and a 16 channel photodiode spatial array gives radial emission profiles. Two-dimensional imaging of the plasma and helicity injector is provided by gated television cameras and associated image-processing software. An array of fiber-coupled photodetectors with H alpha filters view across the midplane and in the injector region to measure neutral hydrogen concentrations. Several novel diagnostics are being fielded including a transient internal probe (TIP) and an ultrashort-pulse reflectometer (USPR) microwave reflectometer. The TIP probe fires a very high velocity optical bullet through the plasma and will provide fairly nonpertabative internal magnetic field and current measurements to compare with an equilibrium code model fitted to wall-mounted probes. The USPR is being designed to study edge density and turbulent fluctuations. A multipoint Thomson scattering system is currently being installed to give radial temperature and density profiles.

McLean, H. S.; Ahmed, A.; Buchenauer, D.; Den Hartog, D.; Domier, C. W.; Hill, D. N.; Holcomb, C.; Hooper, E. B.; Morse, E. C.; Nagata, M. (and others)

2001-01-01

416

Electrochromic WO[subscript 3] Films: Nanotechnology Experiments in Instrumental Analysis and Physical Chemistry Laboratories  

ERIC Educational Resources Information Center

|This experiment teaches students the methodology of investigating novel properties of materials using new instrumental techniques: atomic force microscopy (AFM), electrochemical quartz crystal nanobalance (EQCN), voltammetric techniques (linear potential scan and chronoamperometry), and light reflectance measurements. The unique capabilities of…

Hepel, Maria

2008-01-01

417

ATOMIC AND MOLECULAR PHYSICS: Influence of Isotope Substitution Helium Atom on Partial Cross Sections in He-HF Collisions  

NASA Astrophysics Data System (ADS)

Close-coupling equation and anisotropic potential developed in our previous research are applied to HF-3He (4He, 6He, 8He, 10He) collision system, and partial cross sections (PCSs) at the incident energy of 40 meV are calculated. By analyzing the differences of these PCSs, change rules of PCSs with the increase of partial wave number, and with the change of the mass of isotope substitution helium atom are obtained. The results show that excitation PCSs converge faster than elastic PCSs for collision energy and each of systems considered here. Also excitation PCSs converge more rapidly for high-excited states. Tail effect is present only in elastic scattering and low-excited states but not in high-excited states. With the increase of the mass of isotope substitution helium atom, converging speed of elastic, total inelastic, and state-to-state excitation PCS slows down, and the maxima of these PCSs undergoes a regular change.

Yu, Chun-Ri; Zhang, Jie; Chen, Li; Jiang, Gui-Sheng; Huang, Guo-Dong

2009-11-01

418

ATOMIC AND MOLECULAR PHYSICS: Simulation of Chromium Atom Deposition Pattern in a Gaussain Laser Standing Wave with Different Laser Power  

NASA Astrophysics Data System (ADS)

One-dimensional deposition of a neutral chromium atomic beam focused by a near-resonant Gaussian standing-laser field is discussed by using a fourth-order Runge-Kutta type algorithm. The deposition pattern of neutral chromium atoms in a laser standing wave with different laser power is discussed and the simulation result shows that the full width at half maximum (FWHM) of a nanometer stripe is 115 nm and the contrast is 2.5:1 with laser power 3.93 mW; the FWHM is 0.8 nm and the contrast is 27:1 with laser power 16 mW, the optimal laser power; but with laser power increasing to 50 mW, the nanometer structure forms multi-crests and the quality worsens quickly with increasing laser power.

Zhang, Wen-Tao; Zhu, Bao-Hua

2009-07-01

419

ATOMIC AND MOLECULAR PHYSICS: Calculation of Energy and Other Properties of Muonic Helium Atom Using Boundary Conditions of Wave Function  

NASA Astrophysics Data System (ADS)

The properties of muonic helium atom (4He+2?-e-) in ground state are considered. In this work, the energy and average distance between particles have been obtained using a wave function, which satisfies boundary conditions. It is shown that the obtained energy are very close to the values calculated by others. But the small differences of the expectation values of r2n are due to the incorporated boundary conditions in proposed wave function and are expected.

Rezaei, B.

2010-09-01

420

Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms  

SciTech Connect

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.

2007-04-05

421

Speed Dependence of Atomic Stick-Slip Friction in Optimally Matched Experiments and Molecular Dynamics Simulations  

NASA Astrophysics Data System (ADS)

The atomic stick-slip behavior of a Pt tip sliding on a Au(111) surface is studied with atomic force microscopy (AFM) experiments and accelerated (i.e., reduced sliding speed) molecular dynamics (MD) simulations. The MD and AFM conditions are controlled to match, as closely as possible, the geometry and orientation, load, temperature, and compliance. We observe clear stick-slip without any damage. Comparison of both MD and AFM results with the thermally activated Prandtl-Tomlinson model shows that MD results at the highest speeds are not in the thermally activated regime. At lower speeds, within the thermally activated regime, AFM and MD provide consistent energetics, but attempt frequencies differ by orders of magnitude. Because this discrepancy lies in attempt frequencies and not energetics, atomistic details in MD simulations can be reliably used in interpreting AFM data if the MD speeds are slow enough.

Li, Qunyang; Dong, Yalin; Perez, Danny; Martini, Ashlie; Carpick, Robert W.

2011-03-01

422

Atomic physics with highly-charged heavy ions at the GSI future facility: The scientific program of the SPARC collaboration  

Microsoft Academic Search

The proposed new international accelerator Facility for Antiproton and Ion Research (FAIR) will open up exciting and far-reaching perspectives for atomic physics research in the realm of highly-charged heavy ions: it will provide the highest intensities of relativistic beams of both stable and unstable heavy nuclei. In combination with the strongest possible electromagnetic fields produced by the nuclear charge of

A. Gumberidze; F. Bosch; A. Bräuning-Demian; S. Hagmann; Th. Kühl; D. Liesen; R. Schuch; Th. Stöhlker

2005-01-01

423

Getting Physical with Your Chemistry: Mechanically Investigating Local Structure and Properties of Surfaces with the Atomic Force Microscope  

ERIC Educational Resources Information Center

|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.|

Heinz, William F.; Hoh, Jan H.

2005-01-01

424

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics  

Microsoft Academic Search

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based

G. Aad; E. Abat; B. Abbott; J. Abdallah; A. A. Abdelalim; A. Abdesselam; O. Abdinov; B. Abi; M. Abolins; H. Abramowicz; B. S. Acharya; D. L. Adams; T. N. Addy; C. Adorisio; P. Adragna; T. Adye; J. A. Aguilar-Saavedra; M. Aharrouche; S. P. Ahlen; F. Ahles; A. Ahmad; H. Ahmed; G. Aielli; T. Akdogan; T. P. A. Akesson; G. Akimoto; M. S. Alam; M. A. Alam; J. Albert; S. Albrand; M. Aleksa; I. N. Aleksandrov; F. Alessandria; C. Alexa; G. Alexander; G. Alexandre; T. Alexopoulos; M. Alhroob; G. Alimonti; J. Alison; M. Aliyev; P. P. Allport; S. E. Allwood-Spiers; A. Aloisio; R. Alon; A. Alonso; J. Alonso; M. G. Alviggi; K. Amako; P. Amaral; C. Amelung; V. V. Ammosov; A. Amorim; G. Amoros; N. Amram; C. Anastopoulos; C. F. Anders; K. J. Anderson; A. Andreazza; V. Andrei; M-L. Andrieux; X. S. Anduaga; F. Anghinolfi; A. Antonaki; M. Antonelli; S. Antonelli; B. Antunovic; F. A. Anulli; G. Arabidze; I. Aracena; Y. Arai; A. T. H. Arce; J. P. Archambault; S. Arfaoui; J-F. Arguin; T. Argyropoulos; E. Arik; M. Arik; A. J. Armbruster; O. Arnaez; C. Arnault; A. Artamonov; D. Arutinov; M. Asai; S. Asai; S. Ask; B. Asman; D. Asner; L. Asquith; K. Assamagan; A. Astbury; A. Astvatsatourov; T. Atkinson; G. Atoian; B. Auerbach; E. Auge; K. Augsten; M. A. Aurousseau; N. Austin; G. Avolio; R. Avramidou; A. Axen; C. Ay; G. Azuelos; Y. Azuma; M. A. Baak; G. Baccaglioni; C. Bacci; H. Bachacou; K. Bachas; M. Backes; E. Badescu; P. Bagnaia; Y. Bai; D. C. Bailey; J. T. Baines; O. K. Baker; F. Baltasar Dos Santos Pedrosa; E. Banas; S. Banerjee; D. Banfi; A. Bangert; V. Bansal; S. P. Baranov; A. Barashkou; T. B. Barber; E. L. Barberio; D. Barberis; M. B. Barbero; D. Y. Bardin; T. Barillari; M. Barisonzi; T. Barklow; N. B. Barlow; N. B. Barlow; R. M. Barnett; S. Baron; A. Baroncelli; A. Baroncelli; F. Barreiro; J. Barreiro Guimaraes da Costa; P. Barrillon; R. Bartoldus; D. Bartsch; J. Bastos; R. L. Bates; J. R. Batley; A. Battaglia; M. Battistin; F. Bauer; M. Bazalova; B. Beare; P. H. Beauchemin; R. B. Beccherle; N. Becerici; P. Bechtle; G. A. Beck; H. P. Beck; M. Beckingham; K. H. Becks; I. Bedajanek; A. J. Beddall; P. Bednar; V. A. Bednyakov; C. Bee; S. Behar Harpaz; P. K. Behera; M. Beimforde; C. Belanger-Champagne; P. J. Bell; W. H. Bell; G. Bella; L. Bellagamba; F. Bellina; M. Bellomo; A. Belloni; K. Belotskiy; O. Beltramello; S. Ben Ami; O. Beltramello; D. Benchekroun; M. Bendel; B. H. Benedict; N. Benekos; Y. Benhammou; G. P. Benincasa; D. P. Benjamin; M. Benoit; J. R. Bensinger; K. Benslama; S. Bentvelsen; M. Beretta; D. Berge; E. Bergeaas Kuutmann; N. Berger; F. Berghaus; E. Berglund; J. Beringer; K. Bernardet; P. Bernat; R. Bernhard; C. Bernius; T. Berry; A. Bertin; N. Besson; S. Bethke; R. M. Bianchi; M. Bianco; O. Biebel; J. Biesiada; M. Biglietti; H. Bilokon; S. Binet; A. Bingul; C. Bini; C. Biscarat; M. Bischofberger; U. Bitenc; K. M. Black; R. E. Blair; G. Blanchot; C. Blocker; J. Blocki; A. Blondel; W. Blum; U. Blumenschein; C. Boaretto; G. J. Bobbink; A. Bocci; B. Bodine; J. Boek; N. Boelaert; S. Boeser; J. A. Bogaerts; A. Bogouch; C. Bohm; J. Bohm; V. Boisvert; T. Bold; V. Boldea; V. G. Bondarenko; M. Bondioli; M. Boonekamp; C. N. Booth; P. S. L. Booth; J. R. A. Booth; A. Borisov; G. Borissov; I. Borjanovic; S. Borroni; K. Bos; D. Boscherini; M. Bosman; M. Bosteels; H. Boterenbrood; J. Bouchami; J. Boudreau; E. V. Bouhova-Thacker; C. Boulahouache; C. Bourdarios; J. Boyd; I. R. Boyko; A. Braem; P. Branchini; G. W. Brandenburg; A. Brandt; O. Brandt; U. Bratzler; J. E. Brau; H. M. Braun; B. Brelier; J. Bremer; R. Brenner; S. Bressler; D. Breton; N. D. Brett; D. Breton; F. M. Brochu; I. Brock; R. Brock; E. Brodet; F. Broggi; G. Brooijmans; W. K. Brooks; E. Brubaker; P. A. Bruckman de Renstrom; D. Bruncko; R. Bruneliere; S. Brunet; A. Bruni; G. Bruni; M. Bruschi; T. Buanes; F. B. Bucci; P. Buchholz; A. G. Buckley; I. A. Budagov; V. Buescher; L. Bugge; F. Bujor; O. Bulekov; M. Bunse; T. Buran; H. Burckhart; S. Burdin; S. Burke; E. Busato; C. P. Buszello; F. Butin; B. Butler; J. M. Butler; C. M. Buttar; J. M. Butterworth; T. Byatt; S. Cabrera Urban; D. Caforio; O. Cakir; P. Calafiura; G. Calderini; R. Calkins; L. P. Caloba; R. Calkins; D. Calvet; P. Camarri; M. Cambiaghi; D. Cameron; F. Campabadal Segura; S. Campana; M. Campanelli; V. Canale; J. Cantero; M. D. M. Capeans Garrido; I. Caprini; M. D. M. Capeans Garrido; M. Capua; R. Caputo; C. Caramarcu; R. Cardarelli; T. Carli; G. Carlino; L. Carminati; B. Caron; S. Caron; S. Carron Montero; A. A. Carter; J. R. Carter; J. Carvalho; D. Casadei; M. P. Casado; M. Cascella; C. Caso; A. M. Castaneda Hernadez; E. Castaneda Miranda; V. Castillo Gimenez; N. F. Castro; G. Cataldi; A. Catinaccio; J. R. Catmore; A. Catinaccio; G. Cattani; S. Caughron; D. Cauz; P. Cavalleri; D. Cavalli; M. Cavalli-Sforza; V. Cavasinni; A. Cazzato

2008-01-01

425

Fundamental Physics Observed by Three-Dimensional Imaging of Single Ionized Electrons by Ion-Atom Collisions  

NASA Astrophysics Data System (ADS)

Three-dimensional fully-differential cross sections (FDCS) have provide insight into the mechanisms that contribute to interesting new physics (M. Schulz et al., Nature 422, 48 (2003)). Experiments have observed unique ring-like structures for the traditional "recoil lobe" for single ionization of helium by a 100 MeV/amu C^6+. The ring-shaped structure is not predicted by theory at this energy. However, recent new measurements have been made for 2 MeV/amu that also contained a similar shaped structure. Surprisingly, this structure is now predicted by the Continuum-Distorted-Wave-Eikonal-Initial-State model (CDW-EIS). The first-Born approximation (FBA) which should be valid for high energy approximations does not contain the ring like structure. The FBA is cylindrically symmetric about the momentum, q, transferred to the target atom and could never predict a ring structure centered on the beam axis. The mechanisms that caused both the ring structures and the failure of the theory for higher energies will be discussed.

Foster, M.; Madison, D. H.; Jones, S.; Schulz, M.

2003-10-01

426

Laboratory Measurements in Highly Charged Ions: The Conjunction of Atomic Physics and Astrophysics  

NASA Astrophysics Data System (ADS)

A variety of atomic physics processes are encountered in single-collision, high electron temperature plasmas. These include collisional excitation of highly-charged ions (HCIs) in ground and metastable states; direct and indirect electron ionization; radiative and dielectronic electron-HCI recombination; single and multiple charge-exchanges between a neutral target and an HCI; and X-ray emission from HCIs. In addition, the presence of a strong local electric or magnetic field can induce level mixing, and hence modify the underlying collision physics and cross sections. Plasmas include fusion devices, solar and stellar objects, and planetary upper atmospheres and comets as they interact with HCIs present in solar and stellar winds. Recent JPL laboratory results will be given in the measurement of absolute collisional excitation cross sections in ground-state HCIs, absolute single and multiple charge exchange cross sections, X-ray emission spectra, and (for the case of coronal equilibrium calculations) lifetimes of metastable states in HCIs. Spectroscopic and imaging data from the NASA and ESA space telescopes have been astounding. Present and future missions include Chandra, Hinode, Newton, SOHO, SDO, STEREO, and TRACE. The utility of laboratory data combined with results of accurate theoretical calculations will be illustrated by measurements of the Fe13+ coronal green-line excitation cross section, and resolution of the so-called "Iron Conundrum” when comparing ion densities in Seyfert Galaxies and our Sun. Collaborations with Clark Atlanta Univ. (S. Tayal), Harvard Ctr. for Astrophysics (J. Raymond), Pomona College (R. Mawhorter), Sheffield Hallam Univ. (K. Berrington). and the Univ. Connecticut (Q. Kessel, W. Smith) are gratefully acknowledged. This work was carried out at JPL/Caltech, and was supported through agreement between Caltech and NASA.

Chutjian, Ara

2008-05-01

427

Little Shop of Physics: Online Experiments (Last reviewed in the Scout Report on January 25, 2002)  

NSDL National Science Digital Library

Not to be confused with a certain Roger Corman movie that has a rather similar title, this site presents a wide range of very nice physics experiments, all of which can be done online. Dedicated staff members of the physics department at Colorado State University created the Little Shop of Physics site. The site includes the "Amazing Physics" area, which features experiments that will require common household items. There are a number of rather fun experiments offered up, and they include the "Two Ball Bounce", "Straw Flute", and "Vanishing Rods". Moving right along, "Computer Stuff" offers users a clutch of engaging and potentially mind-blowing experiments that require only a computer and just a touch of interest in physics. Teachers can convert physics neophytes with this site, and students who might be suspect of physics may become passionate converts after just a few visits.

428

Physics Demonstration Experiments at William Jewell College. Revised Edition.  

ERIC Educational Resources Information Center

Presented are descriptions (with photographs) of demonstration equipment purchased, assembled, developed, and used at William Jewell College (Missouri) during the past 25 years. The descriptions are organized into the following topic areas: (1) mechanics; (2) heat; (3) waves, sound, and acoustics; (4) electricity; (5) optics; and (6) atomic and…

Hilton, Wallace A.

429

Physics Demonstration Experiments at William Jewell College. Revised Edition.  

ERIC Educational Resources Information Center

|Presented are descriptions (with photographs) of demonstration equipment purchased, assembled, developed, and used at William Jewell College (Missouri) during the past 25 years. The descriptions are organized into the following topic areas: (1) mechanics; (2) heat; (3) waves, sound, and acoustics; (4) electricity; (5) optics; and (6) atomic and…

Hilton, Wallace A.

430

The Kinetics and Thermodynamics of the Phenol from Cumene Process: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

|Presents a physical chemistry experiment demonstrating the differences between thermodynamics and kinetics. The experiment used the formation of phenol and acetone from cumene hydroperoxide, also providing an example of an industrially significant process. (CS)|

Chen, Edward C. M.; Sjoberg, Stephen L.

1980-01-01

431

Physics of Hard Spheres Experiment (PhaSE) or 'Making Jello in Space'.  

National Technical Information Service (NTIS)

The Physics of Hard Spheres Experiment (PHaSE) is a highly successful experiment that flew aboard two shuttle missions to study the transitions involved in the formation of jellolike colloidal crystals in a microgravity environment. A colloidal suspension...

J. S. Ling M. P. Doherty

1998-01-01

432

ATOMIC AND MOLECULAR PHYSICS: Calculation of the elastic collision properties of Na and Li atoms at ultracold temperature  

NASA Astrophysics Data System (ADS)

This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1 ?+g and the triplet ?3?+u states interatomic potentials for 23Na7Li mixture, it calculates the scattering lengths and the effective ranges by three computational methods, and obtains good agreements. Using the mass scaling method, it also calculates 23Na6Li scattering lengths and s-wave and total elastic cross sections, whose rich resonance structures were found and interpreted in terms of quasibound diatomic levels trapped behind a centrifugal barrier.

Zhang, Ji-Cai; Zhang, Ying; Du, Bing-Ge; Sun, Jin-Feng

2009-04-01

433

Atomic and molecular physics of plasma-based environmental technologies for abatement of volatile organic compounds  

SciTech Connect

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.

Penetrante, B.M.; Hsiao, M.C.; Bardsley, J.N.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States); Kuthi, A. [Plasma and Materials Technologies, Inc., Chatsworth, CA (United States); Burkhart, C.P.; Bayless, J.R. [First Point Scientific, Inc., Agoura Hills, CA (United States)

1996-08-01

434

Protein model refinement using an optimized physics-based all-atom force field.  

PubMed

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. PMID:18550813

Jagielska, Anna; Wroblewska, Liliana; Skolnick, Jeffrey

2008-06-11

435

Accelerator Preparations for Muon Physics Experiments at Fermilab  

SciTech Connect

The use of existing Fermilab facilities to provide beams for two muon experiments - the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment - is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. Operating scenarios being investigated and anticipated accelerator improvements or reconfigurations will be presented.

Syphers, M.J.; /Fermilab

2009-10-01

436

Temperature and Final State Effects in Radio Frequency Spectroscopy Experiments on Atomic Fermi Gases  

SciTech Connect

We present a simple and systematic characterization of the radio frequency (rf) spectra of homogeneous, paired atomic Fermi gases at general temperatures T in the presence of final-state interactions. The spectra, consisting of possible bound states and positive as well as negative detuning ({nu}) continua, satisfy exactly the zeroth- and first-moment sum rules at all T. We show how to best extract the pairing gap and how to detect the {nu}<0 continuum arising from thermally excited quasiparticles, not yet seen experimentally. We explain semiquantitatively recent rf experiments on 'bound-bound' transitions, predicting effects of varying temperature.

He Yan; Chien, C.-C.; Chen Qijin; Levin, K. [James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)

2009-01-16

437

Microgravity experiments in the field of physical chemistry in Japan  

NASA Astrophysics Data System (ADS)

Japan has been operating 'KIBO' (`hope' in Japanese) as Japanese experimental module on ISS (International Space Station) to perform researches on physical, life, medical, space sciences in space. Several research racks and facilities have already been accommodated in the pressurized module of 'KIBO' and some researches have already been carried out. Japan currently has 17 ISS flight projects (including 4 candidates) in the field of physical sciences and also incubates new projects through are search support program named as 'research WG (Working Group)', where 25 research WGs are active in the field of physical sciences. Those include 1 flight candidate and 2 research WGs in the field of physical chemistry. The article introduces those to promote international collaborations.

Natsuisaka, M.; Tsujii, K.; Shimomura, M.; Yabu, H.; Hirai, Y.; Mashiko, T.; Deguchi, S.; Mukai, S.; Inoue, Y.; Nishiyama, Y.; Sawada, M.; Okumura, K.; Sakamoto, K.

2011-12-01

438

Active-learning physics experiments using the Tarzan Swing  

NASA Astrophysics Data System (ADS)

By reversing the conventional laboratory sequences, the Tarzan Swing engages and excites students, improving learning and retention. Problems are solved theoretically, then solutions are verified physically. Failure engenders reanalysis; success brings cheers. Students work overtime eagerly to achieve that success.

Trout, K. P.; Gaston, Charles A.

2001-03-01

439

Simple Laser Scattering Experiment for Biology-Oriented Physics Labs.  

ERIC Educational Resources Information Center

Describes a physics exercise designed for biology and premed majors. The activity is a low intensity laser light scattering laboratory exercise to determine the diameter of micron-sized latex spheres (simulated microbes) in water suspension. (GA)

Orwig, L.; Schrank, G.

1979-01-01

440

Health physics practices and experience at Duke Power Company  

Microsoft Academic Search

The history and development of the health physics and as-low-as-reasonably-achievable (ALARA) program at Duke Power Company's Oconee Nuclear Station is described as are the fundamental elements of the program and how the program works. The benefits of this health physics\\/ALARA program have been determined to be (a) improved quality of manpower planning and scheduling, (b) increased efficiency of shutdown activities,

1986-01-01

441

Buffer choice and effects of sample composition examined by experiment planning methods for determination of molybdenum by atomic absorption with a flame atomizer  

Microsoft Academic Search

The authors use orthogonal experiment planning to define the optimum form of buffer and to establish the effects of sample composition since there are high levels of cation and anion interference in the atomic-absorption determination of molybdenum. A spectroscopic buffer has been identified (HCLOâ + NHâCl mixture), which eliminates the interference from the elements tested and improves the analytical characteristics

P. I. Zavyalkov; A. L. Danishehvskii; R. A. Rakita; A. I. Yakshinskii

1986-01-01

442

Chapter 4: A Comparison of Personal Attributes and Experiences among Physically Active and Inactive Children  

ERIC Educational Resources Information Center

|In this study, the researchers aim to compare the personal attributes and experiences of children who met or exceeded physical activity guidelines with those who did not. By creating profiles, the researchers could compare motor performance, physical fitness, self-efficacy, time spent outdoors during physical activity, social support from friends…

Castelli, Darla M.; Erwin, Heather E.

2007-01-01

443

ATOMIC AND MOLECULAR PHYSICS: High Accuracy Calculation for Excited-State Energies of H Atoms in a Magnetic Field  

NASA Astrophysics Data System (ADS)

Using the recently developed finite-basis-set method with B splines, excited states of H atoms in a magnetic field have been calculated. Energy levels are presented for the ten excited states, 2s0, 3d'0, 3p0, 3p-1, 3d-1, 4d-1, 3d-2, 4d-2, 4f-2, and 5f-2 as a function of magnetic field strengths with a range from zero up to 2.35 × 106 T. The obtained results are compared with available high accuracy theoretical data reported in the literature and found to be in excellent agreement. The comparison also shows that the current method can produce energy levels with an accuracy higher than the existing high accuracy method [Phys. Rev. A 54 (1996) 287]. Here high accuracy energy levels are for the first time reported for the 3d'0, 4d-1, 4d-2, 4f-2, and 5f-2 states.

Zhao, Li-Bo; Du, Meng-Li

2009-08-01

444

Tautomerization of Acetylacetone Enol. A Physical Organic Experiment in Kinetics and Thermodynamics.  

ERIC Educational Resources Information Center

|Describes a physical organic experiment in thermodynamics and kinetics for undergraduate courses in organic chemistry, biochemistry, or physical chemistry. Details background information, solution preparations, equipment and methods, and the suggested experiments such as determination of general-base-catalytic coefficients and the Bronsted…

Spyridis, Greg T.; Meany, J. E.

1988-01-01

445

Using VPN technology to remove physical barriers in linux lab experiments  

Microsoft Academic Search

The ability for students to perform computer laboratory experiments has traditionally been limited to a physical environment. Because of this restriction, lab experiments could be performed only during formal lab hours or open lab time. There are a number of negative consequences resulting from physical barriers, including administrative issues involving lab equipment and room support costs, and site access on

Lee W. Toderick; Philip J. Lunsford II

2007-01-01

446

Tautomerization of Acetylacetone Enol. A Physical Organic Experiment in Kinetics and Thermodynamics.  

ERIC Educational Resources Information Center

Describes a physical organic experiment in thermodynamics and kinetics for undergraduate courses in organic chemistry, biochemistry, or physical chemistry. Details background information, solution preparations, equipment and methods, and the suggested experiments such as determination of general-base-catalytic coefficients and the Bronsted…

Spyridis, Greg T.; Meany, J. E.

1988-01-01

447

An open source/real-time atomic force microscope architecture to perform customizable force spectroscopy experiments  

NASA Astrophysics Data System (ADS)

We describe the realization of an atomic force microscope architecture designed to perform customizable experiments in a flexible and automatic way. Novel technological contributions are given by the software implementation platform (RTAI-LINUX), which is free and open source, and from a functional point of view, by the implementation of hard real-time control algorithms. Some other technical solutions such as a new way to estimate the optical lever constant are described as well. The adoption of this architecture provides many degrees of freedom in the device behavior and, furthermore, allows one to obtain a flexible experimental instrument at a relatively low cost. In particular, we show how such a system has been employed to obtain measures in sophisticated single-molecule force spectroscopy experiments [Fernandez and Li, Science 303, 1674 (2004)]. Experimental results on proteins already studied using the same methodologies are provided in order to show the reliability of the measure system.

Materassi, Donatello; Baschieri, Paolo; Tiribilli, Bruno; Zuccheri, Giampaolo; Samorì, Bruno

2009-08-01

448

Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.  

ERIC Educational Resources Information Center

|Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)|

Anderson, James L.; And Others

1980-01-01

449

Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.  

ERIC Educational Resources Information Center

Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

Anderson, James L.; And Others

1980-01-01

450

Active and laboratory experiments in space plasma physics  

NASA Astrophysics Data System (ADS)

This report focuses on active experiments in space as well as laboratory experiments which are directly related to space phenomena. The active experiments involve particle releases in the CRESS and AMPTE missions. Unexpected results such as the motion of the plasma triggered several interesting computer simulations and a laboratory experiment which will be reviewed. Critical Ionization Phenomena will be discussed in this context. A recent release over Arecibo was used to create a “plasma lens” to focus radiation from the HF heater beam. The higher power triggered several nonlinear processes. Advances in plasma sources and diagnostics have made it possible to scale many laboratory experiments. Discussed here are experiments on Alfvén waves generated by a localized source, 3D magnetic field line reconnection, three dimensional magnetized double layers and simulations of a tethered satellite.

Gekelman, Walter

1995-05-01

451

The polarized atomic-beam target for the EDDA experiment and the time-reversal invariance test at COSY  

NASA Astrophysics Data System (ADS)

For the the EDDA experiment, which was set up to measure the p->-p-> excitation function during the acceleration ramp of the cooler synchrotron COSY at Jülich, a polarized atomic-beam target was designed regarding the restrictions imposed by the geometry of the EDDA detector. Later, when the time-reversal invariance experiment is to be performed, the EDDA detector will serve as efficient internal polarimeter and the source has to deliver tensor polarized deuterons. The modular design of this polarized atomic-beam target that allows to meet these conditions will be discussed in comparison to other existing polarized atomic-beam targets.

Eversheim, P. D.; Altmeier, M.; Felden, O.

1997-02-01

452

Physical Science Experiments in K-12 Schools Related to Space  

NASA Astrophysics Data System (ADS)

In this talk I shall show movies on the demonstration of surface science experiments at various education levels ranging from middle schools to the university. These experiments demonstrate the concepts of surface tension, surface flows, surface reactions and even miscible interfaces. Experiments that demonstrate capillary effects, pressure variations on account of diameter changes, emulsions and foams will be discussed. Applications involving household agents such as space processing, food and detergents will also be given. All of these experiments are part of a kit that we have assembled for free distribution to area schools.

Narayanan, Ranga

453

Elucidating satisfaction with physical activity: An examination of the day-to-day associations between experiences with physical activity and satisfaction during physical activity initiation.  

PubMed

Satisfaction with physical activity is known to be an important factor in physical activity maintenance, but the factors that influence satisfaction are not well understood. The purpose of this study was to elucidate how ongoing experiences with recently initiated physical activity are associated with satisfaction. Participants (n?=?116) included insufficiently active volunteers who initiated a self-directed physical activity regimen and completed daily diaries about their experiences for 28?days. We used multilevel models to examine the associations between experiences with physical activity and satisfaction. Significant between-person effects demonstrated that people reporting higher average levels of positive experiences and lower levels of thinking about the negative aspects of exercise were more likely to report higher levels of satisfaction (ps?experiences and perceived progress toward goals had significant within-person effects (ps?experiences were associated with changes in satisfaction. These findings elucidate a process through which people may determine their satisfaction with physical activity. PMID:23909464

Baldwin, Austin S; Baldwin, Scott A; Loehr, Valerie G; Kangas, Julie L; Frierson, Georita M

2013-08-02

454

ANL-E Health Physics experience with D and D  

SciTech Connect

The Argonne National Laboratory--East (ANL-E) Health Physics Section provides direct and/or oversight support to various D&D projects at ANL-E. The health physics problems encountered have been challenging, primarily because they involved the potential for high internal exposures as well as actual high external exposures. The lessons learned are applicable to other radiological facilities. A number of D&D projects being conducted concurrently at ANL-E are described. The problems encountered are then categorized, and lessons learned and recommendations are provided. The main focus will be limited to the support and technical assistance provided by personnel from the ANL Health Physics Section during the course of the work activities.

Baker, S.I.; Mosho, G.D.; Munyon, W.J.; Murdoch, B.T.; Sholeen, C.M.; Shuman, J.P.

1996-04-01

455

ATOMIC AND MOLECULAR PHYSICS: First-Principles Study on Native Defect Complexes in InN  

NASA Astrophysics Data System (ADS)

We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculations are aimed in the three cases: N/In = 1, N/In > 1 (N-rich), and N/In < 1 (In-rich). Our results indicate that the antisite defect has the lowest formation energy under N/In = 1. The formation energy of nitrogen interstitial (nitrogen vacancy) defect is significantly low under the N-rich (In-rich) condition. Thus the antisite defect is an important defect if N/In = 1, and the nitrogen interstitial (nitrogen vacancy) defect is a vital defect under the N-rich (In-rich) condition. The atomic site relaxation around the nitrogen interstitial and vacancy is investigated. Our calculations show that the nitrogen vacancy cannot be observed although it is one of the most important defects in InN. Our results are confirmed by experiments.

Zhao, Feng-Qi; Shi, Jun-Jie; Yang, Mao

2010-01-01

456

The Social Experience of Physically Disabled Australian University Students  

ERIC Educational Resources Information Center

Research on the university experience of disabled students has focused on barriers in learning and teaching, while the social world of university has as yet gained little attention as a distinctive object of study. Here we examine social experience and socially imposed restrictions through the lenses of social capital and self-concept. A…

Papasotiriou, Maria; Windle, Joel

2012-01-01

457

Women's daily physical health symptoms and stressful experiences across adulthood  

Microsoft Academic Search

This study investigated the extent to which the experience of daily stressors was related to women's age and daily health symptomology, such as flu and cold symptoms. Respondents were 562 women (aged 25–74) who were a part of the National Study of Daily Experiences (NSDE), a telephone diary study examining daily stressful events. The respondents were interviewed by telephone on

Melanie Horn Mallers; David M. Almeida; Shevaun D. Neupert

2005-01-01

458

The Social Experience of Physically Disabled Australian University Students  

ERIC Educational Resources Information Center

|Research on the university experience of disabled students has focused on barriers in learning and teaching, while the social world of university has as yet gained little attention as a distinctive object of study. Here we examine social experience and socially imposed restrictions through the lenses of social capital and self-concept. A…

Papasotiriou, Maria; Windle, Joel

2012-01-01

459

Cold-Atom Physics Using Ultrathin Optical Fibers: Light-Induced Dipole Forces and Surface Interactions  

SciTech Connect

The strong evanescent field around ultrathin unclad optical fibers bears a high potential for detecting, trapping, and manipulating cold atoms. Introducing such a fiber into a cold-atom cloud, we investigate the interaction of a small number of cold cesium atoms with the guided fiber mode and with the fiber surface. Using high resolution spectroscopy, we observe and analyze light-induced dipole forces, van der Waals interaction, and a significant enhancement of the spontaneous emission rate of the atoms. The latter can be assigned to the modification of the vacuum modes by the fiber.

Sague, G.; Vetsch, E.; Alt, W.; Meschede, D.; Rauschenbeutel, A. [Institut fuer Angewandte Physik, Universitaet Bonn, Wegelerstr. 8, 53115 Bonn (Germany)

2007-10-19

460

Nondiffracting Optical Beams: Physical Properties, Experiments, and Applications  

Microsoft Academic Search

The controversial term “nondiffracting beam” was introduced into optics by Durnin in 1987. Discussions related to that term revived interest in problems of the light diffraction and resulted in an appearance of the new research direction of the classical optics, dealing with the localized transfer of electromagnetic energy. In this paper, the physical concept of the nondiffracting propagation is presented

Zdenek Bouchal

2003-01-01

461

Experiences with Interactive Remote Graduate Instruction in Beam Physics.  

ERIC Educational Resources Information Center

|Describes an Internet-based course in Beam Physics offered at Michigan State University (MSU) as part of the Virtual University Degree program. Discusses the importance of local contact persons, technical aspects, equipment, the Internet-based homework assignments, difficulties encountered, and future activities. (Author/AEF)|

Berz, Martin; Erdelyi, Bela; Hoefkens, Jens

1999-01-01

462

Three Presentation Modes of Mechanics Experiments in College Physics.  

ERIC Educational Resources Information Center

The primary purpose of this study was to determine if self-instructional data analysis sessions could be used effectively as traditional college laboratories to reinforce students' understanding of certain principles of mechanics. The secondary purpose was to determine whether any of the 140 college physics students involved had a dependence on…

Johnson, Roger Charles

463

Chicago Public Schools Television Instruction Experiment in High School Physics  

Microsoft Academic Search

This is a report of the large scale controlled experimentation with televised high school physics instruction conducted last year in the Chicago Public Schools. It is especially significant in its critical evaluation of this new technique on the basis of data revealing the comparative achievements of students of differing levels of ability.

Max D. Engelhart; Edward C. Schwachtgen; Mary M. Nee

1958-01-01

464

The Context of Thought Experiments in Physics Learning  

ERIC Educational Resources Information Center

|This paper takes a cognitive perspective in an attempt to analyze mental mechanisms involved in contextual learning. In the following, it is suggested that contextualized environments evoke mental mechanisms that support reasoning about "what if", imaginary situations--utilizing a powerful mental mechanism known from the history of physics as…

Reiner, Miriam

2006-01-01

465

Superconducting magnet protection system for the tokamak physics experiment  

NASA Astrophysics Data System (ADS)

The TPX tokamak must protect 30 superconducting magnets during a complex, pulsed physics scenario. 2.0 MA plasma vertical disruptions will occur at unpredictable intervals. These should not cause quench, but will be difficult to distinguish from quench. A redundant, multiple signal protection system combines conventional voltage taps with signals from cowound conductors, pressure and flow sensors.

Schultz, Joel H.; Chaniotakis, E.; Pillsbury, R. D., Jr.; Wang, P. W.; Citrolo, J.; Neumeyer, C.; Chaplin, M.; Hassenzahl, W. V.

1994-07-01

466

Simple laser scattering experiment for biology-oriented physics labs  

Microsoft Academic Search

A low intensity laser light scattering laboratory exercise has been designed and introduced into the lower division physics course for biology students at the University of California, Santa Barbara. Students determine the diameter of micron-sized latex spheres (simulated microbes) in water suspension. By using their own eyes as part of the measuring apparatus the students become personally involved in the

L. Orwig; G. Schrank

1979-01-01

467

Learning Introductory Quantum Physics: Sensorimotor experiences and mental models  

Microsoft Academic Search

This paper reports a cross-sectional study of Taiwanese physics students' understanding of subatomic phenomena that are explained by quantum mechanics. The study uses students' explanations of their answers to items in a questionnaire as a proxy for students' thinking. The variation in students' explanations is discussed as is the development in the way in which students link different concepts. A

Martin Monk; Richard Duschl

2005-01-01