Sample records for atomic force microscope

  1. Atomic Force Microscope

    SciTech Connect (OSTI)

    Day, R.D.; Russell, P.E.

    1988-12-01T23:59:59.000Z

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  2. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C.; Wang, Chengpu

    2006-08-22T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  3. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V.; Wang, Chengpu

    2004-11-16T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  4. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C. (Port Jefferson, NY); Wang, Chengpu (Upton, NY)

    2003-01-01T23:59:59.000Z

    An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

  5. Measurement of friction coefficients with the atomic force microscope

    E-Print Network [OSTI]

    Attard, Phil

    Measurement of friction coefficients with the atomic force microscope Phil Attard1, Johanna axial method for measuring the friction coefficient with the atomic force microscope is given measurement by measuring the difference between the constant compliance slopes of the extend and retract force

  6. New Atomic Force Microscope Spectroscopy Probes Local Elasticity...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials Characterization New Atomic Force Microscope Spectroscopy Probes Local Elasticity March 04, 2015 Shown is a contact resonance frequency image after nano-oxidation of a...

  7. Design and analysis of a monolithic flexure atomic force microscope

    E-Print Network [OSTI]

    Ljubicic, Dean M

    2008-01-01T23:59:59.000Z

    This thesis details the design, manufacture, and testing of a sub-nanometer accuracy atomic force microscope. It was made to be integrated into the Sub-Atomic Measuring Machine (SAMM) in collaboration with the University ...

  8. Modeling and control of undesirable dynamics in atomic force microscopes

    E-Print Network [OSTI]

    El Rifai, Osamah M

    2002-01-01T23:59:59.000Z

    The phenomenal resolution and versatility of the atomic force microscope (AFM), has made it a widely-used instrument in nanotechnology. In this thesis, a detailed model of AFM dynamics has been developed. It includes a new ...

  9. Measurement of Dynamical Forces between Deformable Drops Using the Atomic Force Microscope. I. Theory

    E-Print Network [OSTI]

    Chan, Derek Y C

    effects of electrical double layer repulsion between oil drops charged by adsorbed surfactant mainly to hydrodynamic lubrication forces. 1. Introduction The atomic force microscope (AFM) has long, such as the interaction between rigid probe particles and oil drops1-4 or between a particle and a bubble.5

  10. High-speed force mapping on living cells with a small cantilever atomic force microscope

    SciTech Connect (OSTI)

    Braunsmann, Christoph; Seifert, Jan; Rheinlaender, Johannes; Schäffer, Tilman E., E-mail: Tilman.Schaeffer@uni-tuebingen [Institute of Applied Physics and LISA, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen (Germany)

    2014-07-15T23:59:59.000Z

    The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ?10?100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed.

  11. On advancement of high speed atomic force microscope technology

    E-Print Network [OSTI]

    SooHoo, Kimberly E

    2008-01-01T23:59:59.000Z

    High speed atomic force microscopy (AFM) is a developing process in which nanoscale objects, such as crystal structures or strands of DNA, can be imaged at rates fast enough to watch processes as they occur. Although current ...

  12. Free vibrations of U-shaped atomic force microscope probes

    SciTech Connect (OSTI)

    Rezaei, E.; Turner, J. A., E-mail: jaturner@unl.edu [Mechanical and Materials Engineering, W342 Nebraska Hall, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2014-05-07T23:59:59.000Z

    Contact resonance atomic force microscope (AFM) methods have been used to quantify the elastic and viscoelastic properties of a variety of materials such as polymers, ceramics, biological materials, and metals with spatial resolution on the order of tens of nanometers. This approach involves measurement of the resonant frequencies of the AFM probe both for the free case and the case for which the tip is in contact with a sample. Vibration models of the probe and tip-sample contact models are then used to determine the sample properties from the frequency behavior and to create images of the sample properties. This work has been primarily focused on rectangular, single-beam probes for which the vibration models are relatively simple. Recently, U-shaped AFM probes have been developed to allow local heating of samples and the resonances of these probes are much more complex. In this article, a simplified analytical model of these U-shaped probes is described. This three beam model includes two beams clamped at one end and connected with a perpendicular cross beam at the other end. The beams are assumed only to bend in flexure and twist but their coupling allows a wide range of possible dynamic behavior. Results are presented for the first ten modes and the mode shapes are shown to have complex coupling between the flexure and twisting of the beams, particularly for the higher modes. All resonant frequency results are in good agreement with finite element results for the three probe designs and two values of thickness considered (all wavenumbers are within 3.0%). This work is anticipated to allow U-shaped probes to be used eventually for quantitative measurements of sample material properties during heating using a contact resonance approach.

  13. Atomic force microscope with combined FTIR-Raman spectroscopy having a micro thermal analyzer

    SciTech Connect (OSTI)

    Fink, Samuel D. (Aiken, SC); Fondeur, Fernando F. (North Augusta, SC)

    2011-10-18T23:59:59.000Z

    An atomic force microscope is provided that includes a micro thermal analyzer with a tip. The micro thermal analyzer is configured for obtaining topographical data from a sample. A raman spectrometer is included and is configured for use in obtaining chemical data from the sample.

  14. A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope

    SciTech Connect (OSTI)

    Steurer, Wolfram, E-mail: wst@zurich.ibm.com; Gross, Leo; Schlittler, Reto R.; Meyer, Gerhard [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)] [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)

    2014-02-15T23:59:59.000Z

    We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K.

  15. Measurements of dispersion forces between colloidal latex particles with the atomic force microscope and comparison with Lifshitz theory

    SciTech Connect (OSTI)

    Elzbieciak-Wodka, Magdalena; Ruiz-Cabello, F. Javier Montes; Trefalt, Gregor; Maroni, Plinio; Borkovec, Michal, E-mail: michal.borkovec@unige.ch [Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1205 Geneva (Switzerland)] [Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1205 Geneva (Switzerland); Popescu, Mihail N. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)] [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2014-03-14T23:59:59.000Z

    Interaction forces between carboxylate colloidal latex particles of about 2 ?m in diameter immersed in aqueous solutions of monovalent salts were measured with the colloidal probe technique, which is based on the atomic force microscope. We have systematically varied the ionic strength, the type of salt, and also the surface charge densities of the particles through changes in the solution pH. Based on these measurements, we have accurately measured the dispersion forces acting between the particles and estimated the apparent Hamaker constant to be (2.0 ± 0.5) × 10{sup ?21} J at a separation distance of about 10 nm. This value is basically independent of the salt concentration and the type of salt. Good agreement with Lifshitz theory is found when roughness effects are taken into account. The combination of retardation and roughness effects reduces the value of the apparent Hamaker constant and its ionic strength dependence with respect to the case of ideally smooth surfaces.

  16. Characterizing absolute piezoelectric microelectromechanical system displacement using an atomic force microscope

    SciTech Connect (OSTI)

    Evans, J., E-mail: radiant@ferrodevices.com; Chapman, S., E-mail: radiant@ferrodevices.com [Radiant Technologies, Inc., 2835C Pan American Fwy NE, Albuquerque, New Mexico 87107 (United States)

    2014-08-14T23:59:59.000Z

    Piezoresponse Force Microscopy (PFM) is a popular tool for the study of ferroelectric and piezoelectric materials at the nanometer level. Progress in the development of piezoelectric MEMS fabrication is highlighting the need to characterize absolute displacement at the nanometer and Ångstrom scales, something Atomic Force Microscopy (AFM) might do but PFM cannot. Absolute displacement is measured by executing a polarization measurement of the ferroelectric or piezoelectric capacitor in question while monitoring the absolute vertical position of the sample surface with a stationary AFM cantilever. Two issues dominate the execution and precision of such a measurement: (1) the small amplitude of the electrical signal from the AFM at the Ångstrom level and (2) calibration of the AFM. The authors have developed a calibration routine and test technique for mitigating the two issues, making it possible to use an atomic force microscope to measure both the movement of a capacitor surface as well as the motion of a micro-machine structure actuated by that capacitor. The theory, procedures, pitfalls, and results of using an AFM for absolute piezoelectric measurement are provided.

  17. High-speed atomic force microscope based on an astigmatic detection system

    SciTech Connect (OSTI)

    Liao, H.-S.; Chen, Y.-H.; Hwu, E.-T.; Chang, C.-S.; Hwang, I.-S., E-mail: ishwang@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Ding, R.-F.; Huang, H.-F.; Wang, W.-M. [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Huang, K.-Y. [Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-10-15T23:59:59.000Z

    High-speed atomic force microscopy (HS-AFM) enables visualizing dynamic behaviors of biological molecules under physiological conditions at a temporal resolution of 1s or shorter. A small cantilever with a high resonance frequency is crucial in increasing the scan speed. However, detecting mechanical resonances of small cantilevers is technically challenging. In this study, we constructed an atomic force microscope using a digital versatile disc (DVD) pickup head to detect cantilever deflections. In addition, a flexure-guided scanner and a sinusoidal scan method were implemented. In this work, we imaged a grating sample in air by using a regular cantilever and a small cantilever with a resonance frequency of 5.5 MHz. Poor tracking was seen at the scan rate of 50 line/s when a cantilever for regular AFM imaging was used. Using a small cantilever at the scan rate of 100 line/s revealed no significant degradation in the topographic images. The results indicate that a smaller cantilever can achieve a higher scan rate and superior force sensitivity. This work shows the potential for using a DVD pickup head in future HS-AFM technology.

  18. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    SciTech Connect (OSTI)

    Karc?, Özgür [NanoMagnetics Instruments Ltd., Hacettepe - ?vedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey); Dede, Münir [NanoMagnetics Instruments Ltd., Hacettepe - ?vedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Oral, Ahmet, E-mail: orahmet@metu.edu.tr [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15T23:59:59.000Z

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ?12 fm/?Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  19. SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography and silicon epitaxial-regrowth

    E-Print Network [OSTI]

    Rokhinson, Leonid

    SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography; published online 10 November 2006 A SiGe quantum dot single-hole transistor passivated by silicon epitaxial are reproducible, in sharp contrast with the noisy and irreproducible I-V characteristics of unpassivated SiGe

  20. Detection of erythrocytes influenced by aging and type 2 diabetes using atomic force microscope

    SciTech Connect (OSTI)

    Jin, Hua; Xing, Xiaobo [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Zhao, Hongxia [Chemistry Department, Jinan University, Guangzhou 510632 (China) [Chemistry Department, Jinan University, Guangzhou 510632 (China); Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510090 (China); Chen, Yong [Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031 (China)] [Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031 (China); Huang, Xun [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Ma, Shuyuan [Chemistry Department, Jinan University, Guangzhou 510632 (China) [Chemistry Department, Jinan University, Guangzhou 510632 (China); The First Affiliated Hospital, Jinan University, Guangzhou 510632 (China); Ye, Hongyan [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Cai, Jiye, E-mail: tjycai@jnu.edu.cn [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China)

    2010-01-22T23:59:59.000Z

    The pathophysiological changes of erythrocytes are detected at the molecular scale, which is important to reveal the onset of diseases. Type 2 diabetes is an age-related metabolic disorder with high prevalence in elderly (or old) people. Up to now, there are no treatments to cure diabetes. Therefore, early detection and the ability to monitor the progression of type 2 diabetes are very important for developing effective therapies. Type 2 diabetes is associated with high blood glucose in the context of insulin resistance and relative insulin deficiency. These abnormalities may disturb the architecture and functions of erythrocytes at molecular scale. In this study, the aging- and diabetes-induced changes in morphological and biomechanical properties of erythrocytes are clearly characterized at nanometer scale using atomic force microscope (AFM). The structural information and mechanical properties of the cell surface membranes of erythrocytes are very important indicators for determining the healthy, diseased or aging status. So, AFM may potentially be developed into a powerful tool in diagnosing diseases.

  1. Note: Mechanical etching of atomic force microscope tip and microsphere attachment for thermal radiation scattering enhancement

    SciTech Connect (OSTI)

    Brissinger, D.; Parent, G., E-mail: gilles.parent@univ-lorraine.fr; Lacroix, D. [Université de Lorraine, LEMTA, UMR 7563, BP70239, 54500 Vandoeuvre-lés-Nancy (France)] [Université de Lorraine, LEMTA, UMR 7563, BP70239, 54500 Vandoeuvre-lés-Nancy (France)

    2013-12-15T23:59:59.000Z

    This Note describes a mechanical etching technique which can be used to prepare silicon tips used in atomic force microscopy apparatus. For such devices, dedicated tips with specific shapes are now commonly used to probe surfaces. Yet, the control of the tip morphology where characteristic scales are lower than 1 ?m remains a real challenge. Here, we detail a controlled etching process of AFM probes apex allowing micrometer-sized sphere attachment. The technique used and influent parameters are discussed and SEM images of the achieved tips are given. Deceptive problems and drawbacks that might occur during the process are also covered.

  2. Magnetic nanowire based high resolution magnetic force microscope probes

    E-Print Network [OSTI]

    Qin, Lu-Chang

    -resolution magnetic force microscope probes using preformed magnetic nanowires. Nickel and cobalt nanowires produced by electrodeposition were directly assembled onto the tip of a commercial atomic force microscope cantilever

  3. A high-pressure atomic force microscope for imaging in supercritical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in-situ atomic scale imaging of a calcite...

  4. The extended wedge method: Atomic force microscope friction calibration for improved tolerance to instrument misalignments, tip offset, and blunt probes

    SciTech Connect (OSTI)

    Khare, H. S.; Burris, D. L. [126 Spencer Laboratory, Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716 (United States)

    2013-05-15T23:59:59.000Z

    One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS{sub 2} to demonstrate the technique. Carbon and single crystal MoS{sub 2} had friction coefficients of {mu}= 0.20 {+-} 0.04 and {mu}= 0.006 {+-} 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS{sub 2} had a friction coefficient of {mu}= 0.005 {+-} 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).

  5. A pressure gauge based on gas density measurement from analysis of the thermal noise of an atomic force microscope cantilever

    SciTech Connect (OSTI)

    Seo, Dongjin; Ducker, William A. [Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Paul, Mark R. [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2012-05-15T23:59:59.000Z

    We describe a gas-density gauge based on the analysis of the thermally-driven fluctuations of an atomic force microscope (AFM) cantilever. The fluctuations are modeled as a ring-down of a simple harmonic oscillator, which allows fitting of the resonance frequency and damping of the cantilever, which in turn yields the gas density. The pressure is obtained from the density using the known equation of state. In the range 10-220 kPa, the pressure readings from the cantilever gauge deviate by an average of only about 5% from pressure readings on a commercial gauge. The theoretical description we use to determine the pressure from the cantilever motion is based upon the continuum hypothesis, which sets a minimum pressure for our analysis. It is anticipated that the cantilever gauge could be extended to measure lower pressures given a molecular theoretical description. Alternatively, the gauge could be calibrated for use in the non-continuum range. Our measurement technique is similar to previous AFM cantilever measurements, but the analysis produces improved accuracy.

  6. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller

    SciTech Connect (OSTI)

    Habibullah, H., E-mail: h.habib@student.adfa.edu.au; Pota, H. R., E-mail: h.pota@adfa.edu.au; Petersen, I. R., E-mail: i.petersen@adfa.edu.au [School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2612 (Australia)

    2014-03-15T23:59:59.000Z

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM’s piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.

  7. Abstract--Automation has long been recognized as an im-portant goal in AFM (Atomic Force Microscope) nanomanipu-

    E-Print Network [OSTI]

    Southern California, University of

    Abstract--Automation has long been recognized as an im- portant goal in AFM (Atomic Force on the order of 10 nm, however, automation has re- mained an elusive goal, primarily because of the spatial multi-tip arrays) or by automating the manipulation process, thus bypassing the time-consuming and labor

  8. Spatial dependence of polycrystalline FTO’s conductance analyzed by conductive atomic force microscope (C-AFM)

    SciTech Connect (OSTI)

    Peixoto, Alexandre Pessoa; Costa, J. C. da [Department of Electrical Engineering, University of Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, PO Box 4386, Brasília - DF, 70919-970 (Brazil)

    2014-05-15T23:59:59.000Z

    Fluorine-doped Tin oxide (FTO) is a highly transparent, electrically conductive polycrystalline material frequently used as an electrode in organic solar cells and optical-electronic devices [1–2]. In this work a spatial analysis of the conductive behavior of FTO was carried out by Conductive-mode Atomic Force Microscopy (C-AFM). Rare highly oriented grains sample give us an opportunity to analyze the top portion of polycrystalline FTO and compare with the border one. It is shown that the current flow essentially takes place through the polycrystalline edge at grain boundaries.

  9. Mechanistic study of dielectric chemical mechanical polishing by spectral and scaling analysis of atomic force microscope images

    SciTech Connect (OSTI)

    Verhoff, M.L.

    1999-12-22T23:59:59.000Z

    Thermal oxide and PETEOS oxide surfaces, polished on an IPEC 472 with different combinations of polish pad, slurry, and polishing conditions, were studied with ex situ atomic force microscopy. The post polish surfaces were analyzed qualitatively by visual inspection and quantitatively by spectral and scaling analyses. Spectral and scaling analyses gave consistent interpretations of morphology evolution. Polishing with either a fixed abrasive pad or alumina-based slurry occurred via a mechanism for which asperities are removed and recesses are filled. A sputtering-type mechanism may contribute to material removal when polishing with silica- or ceria-based slurries.

  10. Accurate capacitive metrology for atomic force microscopy

    E-Print Network [OSTI]

    Mazzeo, Aaron D. (Aaron David), 1979-

    2005-01-01T23:59:59.000Z

    This thesis presents accurate capacitive sensing metrology designed for a prototype atomic force microscope (AFM) originally developed in the MIT Precision Motion Control Lab. The capacitive measurements use a set of ...

  11. Macroscopic model of scanning force microscope

    DOE Patents [OSTI]

    Guerra-Vela, Claudio; Zypman, Fredy R.

    2004-10-05T23:59:59.000Z

    A macroscopic version of the Scanning Force Microscope is described. It consists of a cantilever under the influence of external forces, which mimic the tip-sample interactions. The use of this piece of equipment is threefold. First, it serves as direct way to understand the parts and functions of the Scanning Force Microscope, and thus it is effectively used as an instructional tool. Second, due to its large size, it allows for simple measurements of applied forces and parameters that define the state of motion of the system. This information, in turn, serves to compare the interaction forces with the reconstructed ones, which cannot be done directly with the standard microscopic set up. Third, it provides a kinematics method to non-destructively measure elastic constants of materials, such as Young's and shear modules, with special application for brittle materials.

  12. In situ atomic force microscope study of high-temperature untwinning surface relief in Mn-Fe-Cu antiferromagnetic shape memory alloy

    SciTech Connect (OSTI)

    Wang, L.; Cui, Y. G.; Wan, J. F.; Rong, Y. H.; Zhang, J. H.; Jin, X.; Cai, M. M. [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)] [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-05-06T23:59:59.000Z

    The N-type untwinning surface relief associated with the fcc {r_reversible} fct martensitic transformation (MT) was observed in the Mn{sub 81.5}Fe{sub 14.0}Cu{sub 4.5} antiferromagnetic high-temperature shape memory alloy (SMA) by in situ atomic force microscopy. The measured untwinning relief angles ({theta}{sub {alpha}} Double-Vertical-Line {theta}{sub {beta}}) at the ridge and at the valley were different, and both angles were less than the conventional values. The surface relief exhibited good reversibility during heating and cooling because of the crystallographic reversibility of thermal-elastic SMAs. Untwinning shear was proposed as the main mechanism of the N-type surface relief. The order of the reverse MT was discussed based on the experimental measurements.

  13. Scanning Probe AFM Compound Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probe AFM Compound Microscope Scanning Probe AFM Compound Microscope The atomic force microscope (AFM) compound microscope is designed primarily for fluorescence imaging in the...

  14. On single-molecule DNA sequencing with atomic force microscopy using functionalized carbon nanotube probes

    E-Print Network [OSTI]

    Burns, Daniel James

    2004-01-01T23:59:59.000Z

    A novel DNA sequencing method is proposed based on the specific binding nature of nucleotides and measured by an atomic force microscope (AFM). A single molecule of DNA is denatured and immobilized on an atomically fiat ...

  15. The magnetic resonance force microscope: A new microscopic probe of magnetic materials

    SciTech Connect (OSTI)

    Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1997-08-06T23:59:59.000Z

    The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

  16. Atomic force microscopy of biochemically tagged DNA

    SciTech Connect (OSTI)

    Ogletree, D.F.; Kolbe, W.; Spengler, S.; Salmeron, M. (Lawrence Berkeley Laboratory, CA (United States)); Hansma, H.G.; Bezanilla, M. (Univ. of California, Santa Barbara (United States)); Sano, T.; Smith, C.S.; Cantor, C.R. (Boston Univ., MA (United States))

    1993-05-01T23:59:59.000Z

    Small fragments of DNA of known length were made with the polymerase chain reaction. These fragments had biotin molecules covalently attached at their ends. They were subsequently labeled with a chimeric protein fusion between streptavidin and two immunoglobulin G-binding domains of staphyloccocal protein A. This tetrameric species was expected to bind up to four DNA molecules via their attached biotin moieties. The DNA-protein complex was deposited on mica and imaged with an atomic force microscope. The images revealed the protein chimera at the expected location at the ends of the strands of DNA as well as the expected dimers, trimers, and tetramers of DNA bound to a single protein. 25 refs., 5 figs.

  17. Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Phil Attard

    E-Print Network [OSTI]

    Attard, Phil

    Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Microscope Phil. Adhesion Sci. Technol. 16, 753­791 (2002).) Running title: Friction, Adhesion, and Deformation Abstract for the friction force microscope, quantitative measurements of friction and the ef- fect of adhesion, measurement

  18. A system dynamics approach to user independence in high speed atomic force microscopy

    E-Print Network [OSTI]

    Burns, Daniel James

    2010-01-01T23:59:59.000Z

    As progress in molecular biology and nanotechnology continues, demand for rapid and high quality image acquisition has increased to the point where the limitations of atomic force microscopes (AFM) become impediments to ...

  19. Spanning the Scales of Granular Materials: Microscopic Force Imaging

    E-Print Network [OSTI]

    Nicolas Brodu; Joshua A. Dijksman; Robert P. Behringer

    2014-08-11T23:59:59.000Z

    If you walk on sand, it supports your weight. How do the disordered forces between particles in sand organize, to keep you from sinking? This simple question is surprisingly difficult to answer experimentally: measuring forces in three dimensions, between deeply buried grains, is challenging. We describe here experiments in which we have succeeded in measuring forces inside a granular packing subject to controlled deformations. We connect the measured micro-scale forces to the macro-scale packing force response with an averaging, mean field calculation. This calculation explains how the combination of packing structure and contact deformations produce the unexpected mechanical response of the packing, and reveals a surprising microscopic particle deformation enhancement mechanism.

  20. Noninvasive determination of optical lever sensitivity in atomic force microscopy

    SciTech Connect (OSTI)

    Higgins, M.J.; Proksch, R.; Sader, J.E.; Polcik, M.; Mc Endoo, S.; Cleveland, J.P.; Jarvis, S.P. [Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland); Asylum Research, 6310 Hollister Ave, Santa Barbara, California 93117 (United States); Department of Mathematics and Statistics, University of Melbourne Victoria, 3010 (Australia); Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland); Asylum Research, 6310 Hollister Ave, Santa Barbara, California 93117 (United States); Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland)

    2006-01-15T23:59:59.000Z

    Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. [Rev. Sci. Instrum. 70, 3967 (1999)] to calibrate the spring constant of the cantilever in combination with the equipartition theorem [J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 (1993)] to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity.

  1. Thermal calibration of photodiode sensitivity for atomic force microscopy

    SciTech Connect (OSTI)

    Attard, Phil; Pettersson, Torbjoern; Rutland, Mark W. [School of Chemistry F11, University of Sydney, NSW 2006 Australia (Australia); Department of Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden and Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm (Sweden)

    2006-11-15T23:59:59.000Z

    The photodiode sensitivity in the atomic force microscope is calibrated by relating the voltage noise to the thermal fluctuations of the cantilever angle. The method accounts for the ratio of the thermal fluctuations measured in the fundamental vibration mode to the total, and also for the tilt and extended tip of the cantilever. The method is noncontact and is suitable for soft or deformable surfaces where the constant compliance method cannot be used. For hard surfaces, the method can also be used to calibrate the cantilever spring constant.

  2. Non-contact atomic-level interfacial force microscopy

    SciTech Connect (OSTI)

    Houston, J.E.; Fleming, J.G.

    1997-02-01T23:59:59.000Z

    The scanning force microscopies (notably the Atomic Force Microscope--AFM), because of their applicability to nearly all materials, are presently the most widely used of the scanning-probe techniques. However, the AFM uses a deflection sensor to measure sample/probe forces which suffers from an inherent mechanical instability that occurs when the rate of change of the force with respect to the interfacial separation becomes equal to the spring constant of the deflecting member. This instability dramatically limits the breadth of applicability of AFM-type techniques to materials problems. In the course of implementing a DOE sponsored basic research program in interfacial adhesion, a self-balancing force sensor concept has been developed and incorporated into an Interfacial Force Microscopy (IFM) system by Sandia scientists. This sensor eliminates the instability problem and greatly enhances the applicability of the scanning force-probe technique to a broader range of materials and materials parameters. The impact of this Sandia development was recognized in 1993 by a Department of Energy award for potential impact on DOE programs and by an R and D 100 award for one of the most important new products of 1994. However, in its present stage of development, the IFM is strictly a research-level tool and a CRADA was initiated in order to bring this sensor technology into wide-spread availability by making it accessible in the form of a commercial instrument. The present report described the goals, approach and results of this CRADA effort.

  3. Trapping atoms using nanoscale quantum vacuum forces

    E-Print Network [OSTI]

    D. E. Chang; K. Sinha; J. M. Taylor; H. J. Kimble

    2013-10-22T23:59:59.000Z

    Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here, we show that it is possible to tailor the vacuum forces themselves to provide strong trapping potentials. The trapping scheme takes advantage of the attractive ground state potential and adiabatic dressing with an excited state whose potential is engineered to be resonantly enhanced and repulsive. This procedure yields a strong metastable trap, with the fraction of excited state population scaling inversely with the quality factor of the resonance of the dielectric structure. We analyze realistic limitations to the trap lifetime and discuss possible applications that might emerge from the large trap depths and nanoscale confinement.

  4. Friction forces on atoms after acceleration

    E-Print Network [OSTI]

    Francesco Intravaia; Vanik E. Mkrtchian; Stefan Buhmann; Stefan Scheel; Diego A. R. Dalvit; Carsten Henkel

    2015-02-04T23:59:59.000Z

    The aim of this paper is to revisit the calculation of atom-surface quantum friction in the quantum field theory formulation put forward by Barton [New J. Phys. 12 (2010) 113045]. We show that the power dissipated into field excitations and the associated friction force depend on how the atom is boosted from being initially at rest to a configuration in which it is moving at constant velocity (v) parallel to the planar interface. In addition, we point out that there is a subtle cancellation between the one-photon and part of the two-photon dissipating power, resulting in a leading order contribution to the frictional power which goes as v^4. These results are also confirmed by an alternative calculation of the average radiation force, which scales as v^3.

  5. Laser interferometry force-feedback sensor for an interfacial force microscope

    DOE Patents [OSTI]

    Houston, Jack E.; Smith, William L.

    2004-04-13T23:59:59.000Z

    A scanning force microscope is provided with a force-feedback sensor to increase sensitivity and stability in determining interfacial forces between a probe and a sample. The sensor utilizes an interferometry technique that uses a collimated light beam directed onto a deflecting member, comprising a common plate suspended above capacitor electrodes situated on a substrate forming an interference cavity with a probe on the side of the common plate opposite the side suspended above capacitor electrodes. The probe interacts with the surface of the sample and the intensity of the reflected beam is measured and used to determine the change in displacement of the probe to the sample and to control the probe distance relative to the surface of the sample.

  6. Controlling a magnetic force microscope to track a magnetized nanosize particle

    E-Print Network [OSTI]

    Andersson, Sean B.

    1 Controlling a magnetic force microscope to track a magnetized nanosize particle Dimitar Baronov and Sean B. Andersson Abstract--In this paper, we introduce a scheme for tracking a magnetic nanoparticle moving in three-dimensions using a magnetic force microscope (MFM). The stray magnetic field

  7. Long range forces between atomic impurities in liquid helium

    E-Print Network [OSTI]

    Long range forces between atomic impurities in liquid helium J. Dupont-Roc Laboratoire Kastler in a polarizable medium. We show that atomic impurities in liquid helium may indeed realize repulsive forces embedded in liquid helium, super uid or not. Solid helium have also been used. Successful theoretical

  8. atomic force microscope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shift technique. This experiment was performed at a pressure of 3x10-8 Torr with hollow glass sphere of 41.3 mcm radius. Special attention is paid to electrostatic...

  9. atomic force microscopic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shift technique. This experiment was performed at a pressure of 3x10-8 Torr with hollow glass sphere of 41.3 mcm radius. Special attention is paid to electrostatic...

  10. Towards a quantum gas microscope for fermionic atoms

    E-Print Network [OSTI]

    Ramasesh, Vinay (Vinay V.)

    2012-01-01T23:59:59.000Z

    This thesis reports the achievement of a two-species apparatus for use in an upcoming experiment with fermionic ultracold atomic gases. First, we describe the construction of a laser system capable of cooling and trapping ...

  11. atomic force acoustic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    systems Peder of Denmark 31 January 2008 12;ii 12;Abstract Within the field of microfluidics and lab-on-a-chip systems 7 3 Mechanical Diode-Based Ultrasonic Atomic Force...

  12. Microscopic Lensing by a Dense, Cold Atomic Sample

    E-Print Network [OSTI]

    Stetson Roof; Kasie Kemp; Mark Havey; I. M. Sokolov; D. V. Kupriyanov

    2014-12-01T23:59:59.000Z

    We demonstrate that a cold, dense sample of 87Rb atoms can exhibit a micron-scale lensing effect, much like that associated with a macroscopically-sized lens. The experiment is carried out in the fashion of traditional z-scan measurements but in much weaker fields and where close attention is paid to the detuning dependence of the transmitted light. The results are interpreted using numerical simulations and by modeling the sample as a thin lens with a spherical focal length.

  13. SCANNING TUNNELING MICROSCOPE Operating Instructions On How To Get Atomic Resolution Images

    E-Print Network [OSTI]

    SCANNING TUNNELING MICROSCOPE Operating Instructions On How To Get Atomic Resolution Images Do: STM Set-Up: Use either a scanning tip from the tip wire box (skip to the "While holding the tip wire a 45-degree cut on one end of the tip wire, which becomes the scanning tip. Hold the tip wire

  14. Using Atom Interferometry to Search for New Forces

    SciTech Connect (OSTI)

    Wacker, Jay G.; /SLAC

    2009-12-11T23:59:59.000Z

    Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10{sup 2} and near-future advances will be able to rewrite the limits for forces with ranges from 100 {micro}m to 1km.

  15. Study of anion adsorption at the gold--aqueous solution interface by atomic force microscopy

    SciTech Connect (OSTI)

    Biggs, S.; Mulvaney, P.; Grieser, F. (Univ. of Melbourne (Australia)); Zukoski, C.F. (Univ. of Illinois, Urbana, IL (United States))

    1994-10-05T23:59:59.000Z

    The forces between a gold coated colloidal silica sphere and a pure gold plate have been measured in aqueous solution as a function of electrolyte concentration using an atomic force microscope (AFM). Forces in the presence of gold(III) chloride (HAuCl[sub 4]), sodium chloride, and trisodium citrate were recorded as a function of concentration. Each of these anion species is present during the formation of colloidal gold by the reduction of gold(III) chloride with trisodium citrate. In pure water the force between the gold surfaces was exclusively attractive. In sodium chloride or trisodium citrate solution a repulsive interaction was observed which is attributed to the adsorption of these anions at the gold/water interface. The observed interaction force in gold(III) chloride solution was always attractive, the surface potential never exceeding 20 mV. Data taken in aqueous solutions of citrate and chloride ions together suggested that the citrate ions were preferentially adsorbed to the surface of the gold. Addition of gold(III) chloride to the AFM liquid cell after the pre-adsorption of citrate anions caused the force of interaction to change from a repulsvie force to an attractive one initially as the gold(III) chloride was reduced to gold by the citrate anions. 33 refs., 11 figs.

  16. Dynamic study of tunable stiffness scanning microscope probe

    E-Print Network [OSTI]

    Vega González, Myraida Angélica

    2005-01-01T23:59:59.000Z

    This study examines the dynamic characteristics of the in-plane tunable stiffness scanning microscope probe for an atomic force microscope (AFM). The analysis was carried out using finite element analysis (FEA) methods for ...

  17. Dielectric spectroscopy at the nanoscale by atomic force microscopy: A simple model linking materials properties and experimental response

    SciTech Connect (OSTI)

    Miccio, Luis A., E-mail: luisalejandro-miccio@ehu.es; Colmenero, Juan [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Donostia International Physics Center, P. M. de Lardizabal 4, 20018 San Sebastián (Spain); Departamento de Física de Materiales (UPV/EHU), 20080 San Sebastián (Spain); Kummali, Mohammed M.; Alegría, Ángel [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Departamento de Física de Materiales (UPV/EHU), 20080 San Sebastián (Spain); Schwartz, Gustavo A. [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Donostia International Physics Center, P. M. de Lardizabal 4, 20018 San Sebastián (Spain)

    2014-05-14T23:59:59.000Z

    The use of an atomic force microscope for studying molecular dynamics through dielectric spectroscopy with spatial resolution in the nanometer scale is a recently developed approach. However, difficulties in the quantitative connection of the obtained data and the material dielectric properties, namely, frequency dependent dielectric permittivity, have limited its application. In this work, we develop a simple electrical model based on physically meaningful parameters to connect the atomic force microscopy (AFM) based dielectric spectroscopy experimental results with the material dielectric properties. We have tested the accuracy of the model and analyzed the relevance of the forces arising from the electrical interaction with the AFM probe cantilever. In this way, by using this model, it is now possible to obtain quantitative information of the local dielectric material properties in a broad frequency range. Furthermore, it is also possible to determine the experimental setup providing the best sensitivity in the detected signal.

  18. Noncontact atomic force microscopy simulator with phase-locked-loop controlled frequency detection and excitation

    E-Print Network [OSTI]

    Nony, L; Schaer, D; Pfeiffer, O; Wezel, A; Meyer, E; Nony, Laurent; Baratoff, Alexis Prof.; Schaer, Dominique; Pfeiffer, Oliver; Wezel, Adrian; Meyer, Ernst

    2006-01-01T23:59:59.000Z

    A simulation of an atomic force microscope operating in the constant amplitude dynamic mode is described. The implementation mimics the electronics of a real setup including a digital phase-locked loop (PLL). The PLL is not only used as a very sensitive frequency detector, but also to generate the time-dependent phase shifted signal driving the cantilever. The optimum adjustments of individual functional blocks and their joint performance in typical experiments are determined in detail. Prior to testing the complete setup, the performances of the numerical PLL and of the amplitude controller were ascertained to be satisfactory compared to those of the real components. Attention is also focused on the issue of apparent dissipation, that is, of spurious variations in the driving amplitude caused by the nonlinear interaction occurring between the tip and the surface and by the finite response times of the various controllers. To do so, an estimate of the minimum dissipated energy that is detectable by the instru...

  19. Calibration of an interfacial force microscope for MEMS metrology : FY08-09 activities.

    SciTech Connect (OSTI)

    Houston, Jack E.; Baker, Michael Sean; Crowson, Douglas A.; Mitchell, John Anthony; Moore, Nathan W.

    2009-10-01T23:59:59.000Z

    Progress in MEMS fabrication has enabled a wide variety of force and displacement sensing devices to be constructed. One device under intense development at Sandia is a passive shock switch, described elsewhere (Mitchell 2008). A goal of all MEMS devices, including the shock switch, is to achieve a high degree of reliability. This, in turn, requires systematic methods for validating device performance during each iteration of design. Once a design is finalized, suitable tools are needed to provide quality assurance for manufactured devices. To ensure device performance, measurements on these devices must be traceable to NIST standards. In addition, accurate metrology of MEMS components is needed to validate mechanical models that are used to design devices to accelerate development and meet emerging needs. Progress towards a NIST-traceable calibration method is described for a next-generation, 2D Interfacial Force Microscope (IFM) for applications in MEMS metrology and qualification. Discussed are the results of screening several suitable calibration methods and the known sources of uncertainty in each method.

  20. Manipulation and sorting of magnetic particles by a magnetic force microscope on a microfluidic magnetic trap platform

    E-Print Network [OSTI]

    Donahue, Michael J.

    1 Manipulation and sorting of magnetic particles by a magnetic force microscope on a microfluidic magnetic trap platform Elizabeth Mirowski, John Moreland, Arthur Zhang and Stephen E. Russek Electronics and Electrical Engineering Laboratory, National Institute of Standards and Technology, Boulder, CO 80305 Michael

  1. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

    2010-07-13T23:59:59.000Z

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  2. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

    2009-10-27T23:59:59.000Z

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  3. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

    2009-11-10T23:59:59.000Z

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of impaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  4. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

    2010-06-29T23:59:59.000Z

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  5. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

    2007-12-11T23:59:59.000Z

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  6. Dynamical Casimir–Polder force on a partially dressed atom in a cavity comprising a dielectric

    SciTech Connect (OSTI)

    Yang, H.; Zheng, T.Y., E-mail: zhengty@nenu.edu.cn; Zhang, X.; Shao, X.Q.; Pan, S.M., E-mail: pansm717@nenu.edu.cn

    2014-05-15T23:59:59.000Z

    We put a two-level atom into a cavity comprising a dielectric with output coupling. An analytical expression of the dynamical Casimir–Polder force in such a system is obtained when the system starts from a partially dressed state. And the effects of several relevant parameters of the system on the time-dependent force are also discussed. -- Highlights: •We get the dynamical CP force on a partially dressed atom in a dielectric cavity. •The force in this cavity is larger than that in infinite dielectric space. •The force is not symmetric with respect to the center of the cavity. •The oscillating time of the force increases with the cavity size.

  7. Size effects in bimetallic nickelgold nanowires: Insight from atomic force microscopy nanoindentation

    E-Print Network [OSTI]

    Sansoz, Frederic

    Size effects in bimetallic nickel­gold nanowires: Insight from atomic force microscopy the local plastic behavior and hardness properties of electrodeposited bimetallic Ni­Au NWs ranging from 60 rights reserved. Keywords: Atomic force microscopy (AFM); Nanowire; Nickel; Gold; Nanoindentation 1

  8. Fractal properties in fundamental force coupling constants, in atomic energies, and in elementary particle masses

    E-Print Network [OSTI]

    Boris Tatischeff

    2011-04-28T23:59:59.000Z

    Using the discrete-scale invariance theory, we show that the coupling constants of fundamental forces, the atomic masses and energies, and the elementary particle masses, obey to the fractal properties.

  9. VOLUME 76, NUMBER 8 P H Y S I C A L R E V I E W L E T T E R S 19 FEBRUARY 1996 Compliance Measurements of Confined Polystyrene Solutions by Atomic Force Microscopy

    E-Print Network [OSTI]

    of Chemistry, McGill University, Montreal, Canada H3A 2K6 4 Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131-1096 (Received 16 August 1995) The use of the atomic force microscope (AFM) as a local probe for elastohydrodynamic lubrication is discussed. Compliances are measured with a modified

  10. Polarizable Atomic Multipole-Based AMOEBA Force Field for Proteins Jiajing Zhang,

    E-Print Network [OSTI]

    Ponder, Jay

    Polarizable Atomic Multipole-Based AMOEBA Force Field for Proteins Yue Shi, Zhen Xia, Jiajing Zhang is presented. The current version (AMOEBA- 2013) utilizes permanent electrostatic multipole moments through- ments. The atomic multipole electrostatic parameters for each amino acid residue type are derived from

  11. Detection of Percolating Paths in PMMA/CB Segregated Network Composites Using Electrostatic Force Microscopy and Conductive Atomic Force Microscopy

    SciTech Connect (OSTI)

    Waddell, J. [Georgia Institute of Technology; Ou, R. [Georgia Institute of Technology; Gupta, S. [Georgia Institute of Technology; Parker, A. [Georgia Institute of Technology; Gerhardt, Dr. Rosario [Georgia Institute of Technology; Seal, Katyayani [ORNL; Kalinin, Sergei V [ORNL; Baddorf, Arthur P [ORNL

    2009-01-01T23:59:59.000Z

    Composite specimens possessing polyhedral segregated network microstructures require a very small amount of nanosize filler, <1 vol %, to reach percolation because percolation occurs by accumulation of the fillers along the edges of the deformed polymer matrix particles. In this paper, electrostatic force microscopy (EFM) and conductive atomic force microscopy (C-AFM) were used to confirm the location of the nanosize fillers and the corresponding percolating paths in polymethyl methacrylate/carbon black composites. The EFM and C-AFM images revealed that the polyhedral polymer particles were coated with filler, primarily on the edges as predicted by the geometric models provided.

  12. QED Corrections to the Electromagnetic Abraham Force. Casimir Momentum of the Hydrogen atom?

    E-Print Network [OSTI]

    Bart Van Tiggelen; Sebastien Kawka; Geert L. J. A. Rikken

    2012-02-23T23:59:59.000Z

    We develop a QED approach to find the contribution of the quantum vacuum to the electromagnetic Abraham force. Semi-classical theories predict diverging contributions from the quantum vacuum. We show that the divergencies disappear by Kramers-Bethe mass-renormalization. The finite remainder is compared to the relativistic corrections to the Abraham force. This work generalizes an earlier paper [1], dedicated to the harmonic oscillator, to the hydrogen atom and corrects two subtle errors.

  13. A Preisach Model for Quantifying Hysteresis in an Atomic Force Microscope

    E-Print Network [OSTI]

    . increases to the point where feedback mechanisms are amplifying noise rather than attenuating unmodeled and constitutive nonlin- earities even at low drive levels. Feedback mechanisms can mitigate the deleterious effects of these nonlinearities for low frequency operation but such techniques fail at higher frequencies

  14. A Preisach Model for Quantifying Hysteresis in an Atomic Force Microscope

    E-Print Network [OSTI]

    #ects of these nonlinearities for low frequency operation but such techniques fail at higher frequencies due to increased noise lateral sweep. increases to the point where feedback mechanisms are amplifying noise rather than and constitutive nonlin­ earities even at low drive levels. Feedback mechanisms can mitigate the deleterious e

  15. Viscoelastic Study Using an Atomic Force Microscope Modified to Operate as a Nanorheometer

    E-Print Network [OSTI]

    Attard, Phil

    pharmaceutical compounds, through to polymer composites,blends,novelorganicsemiconductornetworks, and even,11,12 Although category I nanorheology can be conducted without any subsequent modification to the existing AFM

  16. Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force

    E-Print Network [OSTI]

    Cui, Yi

    Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force Microscopy Seung Sae, Stanford University, Stanford, California 94305 ABSTRACT Ultrathin topological insulator nanostructures), the layered bismuth selenide (Bi2Se3), a single Dirac-cone topological insulator with a large bulk gap, can

  17. Contribution to crystallographic slip assessment by means of topographic measurements achieved with atomic force microscopy

    SciTech Connect (OSTI)

    Kahloun, C. [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Badji, R. [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Welding and NDT Research Centre, B. P. 64, Cheraga (Algeria); Bacroix, B., E-mail: bacroix@lpmtm.univ-paris13.fr [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Bouabdallah, M. [E.N.P, 10 av. Hassan Badi, 16200 El Harrah Alger (Algeria)

    2010-09-15T23:59:59.000Z

    In this paper, atomic force microscopy (AFM) is used to quantitatively characterize the plastic glide occurring during tensile deformation of a duplex 2205 stainless steel sample. We demonstrate that an appropriate treatment of the topographic image issued from AFM measurements allows precise and quantitative information about the characteristics of plastic deformation and especially the amount of crystallographic slip.

  18. Nuclear pairing from microscopic forces: singlet channels and higher-partial waves

    E-Print Network [OSTI]

    S. Maurizio; J. W. Holt; P. Finelli

    2014-08-26T23:59:59.000Z

    Background: An accurate description of nuclear pairing gaps is extremely important for understanding static and dynamic properties of the inner crusts of neutron stars and to explain their cooling process. Purpose: We plan to study the behavior of the pairing gaps $\\Delta_F$ as a function of the Fermi momentum $k_F$ for neutron and nuclear matter in all relevant angular momentum channels where superfluidity is believed to naturally emerge. The calculations will employ realistic chiral nucleon-nucleon potentials with the inclusion of three-body forces and self-energy effects. Methods: The superfluid states of neutron and nuclear matter are studied by solving the BCS gap equation for chiral nuclear potentials using the method suggested by Khodel et al., where the original gap equation is replaced by a coupled set of equations for the dimensionless gap function $\\chi(p)$ defined by $\\Delta(p) = \\Delta_F \\chi(p)$ and a non-linear algebraic equation for the gap magnitude $\\Delta_F = \\Delta(p_F)$ at the Fermi surface. This method is numerically stable even for small pairing gaps, such as that encountered in the coupled $^3PF_2$ partial wave. Results: We have successfully applied Khodel's method to singlet ($S$) and coupled channel ($SD$ and $PF$) cases in neutron and nuclear matter. Our calculations agree with other ab-initio approaches, where available, and provide crucial inputs for future applications in superfluid systems.

  19. Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy and ultra-small angle

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy of silica aerogels has been extensively studied mainly by scattering techniques (neutrons, X-rays, light) and atomic force microscopy (AFM) experiments have been carried out on aerogels at dierent steps of densi

  20. Topography and Mechanical Property Mapping of International Simple Glass Surfaces with Atomic Force Microscopy

    SciTech Connect (OSTI)

    Hopf, Juliane [ORNL; Pierce, Eric M [ORNL

    2014-01-01T23:59:59.000Z

    Quantitative Nanomechanical Peak Force (PF-QNM) TappingModeTM atomic force microscopy measurements are presented for the first time on polished glass surfaces. The PF-QNM technique allows for topography and mechanical property information to be measured simultaneously at each pixel. Results for the international simple glass which represents a simplified version of SON68 glass suggests an average Young s modulus of 78.8 15.1 GPa is within the experimental error of the modulus measured for SON68 glass (83.6 2 GPa) with conventional approaches. Application of the PF-QNM technique will be extended to in situ glass corrosion experiments with the goal of gaining atomic-scale insights into altered layer development by exploiting the mechanical property differences that exist between silica gel (e.g., altered layer) and pristine glass surface.

  1. Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function

    SciTech Connect (OSTI)

    Tung, Ryan C., E-mail: ryan.tung@nist.gov; Killgore, Jason P.; Hurley, Donna C. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2014-06-14T23:59:59.000Z

    We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.

  2. Switching surface polarization of atomic force microscopy probe utilizing photoisomerization of photochromic molecules

    SciTech Connect (OSTI)

    Aburaya, Yoshihiro; Nomura, Hikaru; Kageshima, Masami; Naitoh, Yoshitaka; Li, Yan Jun; Sugawara, Yasuhiro [Department of Applied Physics, Graduate School of Engineering, Osaka University 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2011-03-15T23:59:59.000Z

    An attempt to develop an atomic force microscopy (AFM) probe with optically switchable polarization is described. Modification with a single molecular layer of photochromic molecules was attempted onto a Si substrate that is a prototype for a probe surface. Polarization switching caused by alternate irradiation of UV and visible lights were detected using the electrostatic force?>spectroscopy (EFS) technique. Si substrates modified with spiropyran and azobenzene exhibited reversible polarization switching that caused changes in CPD of about 100 and 50 mV, respectively. Modification with spiropyran was also attempted onto a Si probe and resulted in a CPD change of about 100 mV. It was confirmed that modification of an AFM probe or substrate with a single molecular layer of photochromic molecules can generate surface polarization switching of a mechanically detectable level.

  3. In situ atomic force microscopy imaging of electroprecipitated nickel hydrous oxide films in alkaline electrolytes

    SciTech Connect (OSTI)

    Chen, R.; Mo, Y.; Scherson, D.A. (Case Western Reserve Univ., Cleveland, OH (United States))

    1994-11-01T23:59:59.000Z

    In situ atomic force microscopy images of nickel hydrous oxide films electrodeposited on the basal plane of highly oriented pyrolytic graphite in alkaline electrolytes have shown that a stepwise oxidation leads to irreversible formation of wide crevices throughout the material. Upon subsequent stepwise reduction, the gaps close leaving a hairline type crack which follows the profile of the crevice. These potential induced structural rearrangements have been attributed to stresses induced by differences in the densities of the nickel hydrous oxide in the two oxidation states. 9 refs., 5 figs.

  4. Nanosecond switching in GeSe phase change memory films by atomic force microscopy

    SciTech Connect (OSTI)

    Bosse, James L.; Huey, Bryan D., E-mail: bhuey@ims.uconn.edu [Department of Materials Science and Engineering, 97 North Eagleville Road, Unit 3136, Storrs, Connecticut 06269-3136 (United States); Grishin, Ilya; Kolosov, Oleg V. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Gyu Choi, Yong [Department of Materials Science and Engineering, Korea Aerospace University, Goyang-si, Gyeonggi-do, 412-791 (Korea, Republic of); Cheong, Byung-ki; Lee, Suyoun [Electronic Materials Research Center, Korea Institute of Science and Technology, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-02-03T23:59:59.000Z

    Nanosecond scale threshold switching is investigated with conducting atomic force microscopy (AFM) for an amorphous GeSe film. Switched bits exhibit 2–3 orders of magnitude variations in conductivity, as demonstrated in phase change based memory devices. Through the nm-scale AFM probe, this crystallization was achieved with pulse durations of as low as 15?ns, the fastest reported with scanning probe based methods. Conductance AFM imaging of the switched bits further reveals correlations between the switched volume, pulse amplitude, and pulse duration. The influence of film heterogeneities on switching is also directly detected, which is of tremendous importance for optimal device performance.

  5. Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy

    SciTech Connect (OSTI)

    Loganathan, Muthukumaran; Bristow, Douglas A., E-mail: dbristow@mst.edu [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri 65401 (United States)

    2014-04-15T23:59:59.000Z

    This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

  6. Atomic Forces from Electronic Energies Via the Hellmann-Feynman Theorem, with Application to Semiconductor (110) Surface Relaxation

    E-Print Network [OSTI]

    SANKEY, OF; Allen, Roland E.

    1986-01-01T23:59:59.000Z

    to be the dominant force on a surface As atom and that it acts per- pendicular (noncentral) to the bonding direction between the two surface atoms. From the calculations of Sec. IV, we find this force in GaAs (atom 1 is As) to be + 0.71 eV/A, while the recursion... method for n =2 yields + 0.03 eV/A and for n =4 yields + 0.33 eV/A. Similar indirect interactions have been previously noted between ada- toms. ' To include these multiatom effects at a surface, we have to consider a finite slab exactly...

  7. A serial-kinematic nanopositioner for high-speed atomic force microscopy

    SciTech Connect (OSTI)

    Wadikhaye, Sachin P., E-mail: sachin.wadikhaye@uon.edu.au; Yong, Yuen Kuan; Reza Moheimani, S. O. [School of Electrical Engineering and Computer Science, The University of Newcastle, Callaghan, NSW (Australia)

    2014-10-15T23:59:59.000Z

    A flexure-guided serial-kinematic XYZ nanopositioner for high-speed Atomic Force Microscopy is presented in this paper. Two aspects influencing the performance of serial-kinematic nanopositioners are studied in this work. First, mass reduction by using tapered flexures is proposed to increased the natural frequency of the nanopositioner. 25% increase in the natural frequency is achieved due to reduced mass with tapered flexures. Second, a study of possible sensor positioning in a serial-kinematic nanopositioner is presented. An arrangement of sensors for exact estimation of cross-coupling is incorporated in the proposed design. A feedforward control strategy based on phaser approach is presented to mitigate the dynamics and nonlinearity in the system. Limitations in design approach and control strategy are discussed in the Conclusion.

  8. Investigation of leakage current paths in n-GaN by conductive atomic force microscopy

    SciTech Connect (OSTI)

    Kim, Bumho; Park, Yongjo, E-mail: yp0520@snu.ac.kr, E-mail: eyoon@snu.ac.kr [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of)] [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Moon, Daeyoung; Nanishi, Yasushi [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)] [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Joo, Kisu [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of) [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Oh, Sewoung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Young Kuk [Korea Research Institute of Chemical Technology, Daejon 305-600 (Korea, Republic of)] [Korea Research Institute of Chemical Technology, Daejon 305-600 (Korea, Republic of); Yoon, Euijoon, E-mail: yp0520@snu.ac.kr, E-mail: eyoon@snu.ac.kr [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of) [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-03-10T23:59:59.000Z

    We have investigated electrical characteristics of leakage current paths in n-GaN layer grown by metal-organic chemical vapor deposition with conductive-atomic force microscopy (C-AFM). The C-AFM mapping shows two kinds of leakage current paths existing in the n-GaN layer: open-core dislocation and pure screw dislocation. From the localized I-V curves measured by C-AFM, we confirmed that the open-core screw dislocation shows more significant leakage current. We explained these results in terms of a modified Schottky band model based on donor states formed by oxygen segregation at the (10?10) sidewall of the open-core screw dislocation.

  9. ATOMIC FORCE LITHOGRAPHY OF NANO/MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING OF AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Mendez-Torres, A.; Torres, R.; Lam, P.

    2011-07-15T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  10. ATOMIC FORCE LITHOGRAPHY OF NANO MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING IN AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Torres, R.; Mendez-Torres, A.; Lam, P.

    2011-06-09T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  11. Advances in quantitative nanoscale subsurface imaging by mode-synthesizing atomic force microscopy

    SciTech Connect (OSTI)

    Vitry, P.; Bourillot, E.; Plassard, C.; Lacroute, Y.; Lesniewska, E. [ICB, UMR CNRS 6303 CNRS-University of Bourgogne, Dijon F-21078 (France); Tetard, L. [Nanoscience Technology Center, University of Central Florida, Orlando, Florida 32826 (United States)

    2014-08-04T23:59:59.000Z

    This paper reports on advances toward quantitative non-destructive nanoscale subsurface investigation of a nanofabricated sample based on mode synthesizing atomic force microscopy with heterodyne detection, addressing the need to correlate the role of actuation frequencies of the probe f{sub p} and the sample f{sub s} with depth resolution for 3D tomography reconstruction. Here, by developing a simple model and validating the approach experimentally through the study of the nanofabricated calibration depth samples consisting of buried metallic patterns, we demonstrate avenues for quantitative nanoscale subsurface imaging. Our findings enable the reconstruction of the sample depth profile and allow high fidelity resolution of the buried nanostructures. Non-destructive quantitative nanoscale subsurface imaging offers great promise in the study of the structures and properties of complex systems at the nanoscale.

  12. Energy shift and Casimir-Polder force for an atom out of thermal equilibrium near a dielectric substrate

    E-Print Network [OSTI]

    Wenting Zhou; Hongwei Yu

    2014-09-07T23:59:59.000Z

    We study the energy shift and the Casimir-Polder force of an atom out of thermal equilibrium near the surface of a dielectric substrate. We first generalize, adopting the local source hypothesis, the formalism proposed by Dalibard, Dupont-Roc and Cohen-Tannoudji, which separates the contributions of thermal fluctuations and radiation reaction to the energy shift and allows a distinct treatment to atoms in the ground and excited states, to the case out of thermal equilibrium, and then use the generalized formalism to calculate the energy shift and the Casimir-Polder force of an isotropically polarizable neutral atom. We identify the effects of the thermal fluctuations that originate from the substrate and the environment and discuss in detail how the Casimir-Polder force out of thermal equilibrium behaves in three different distance regions in both the low-temperature limit and the high-temperature limit for both the ground-state and excited-state atoms, with special attention devoted to the new features as opposed to thermal equilibrium. In particular, we recover the new behavior of the atom-wall force out of thermal equilibrium at large distances in the low temperature limit recently found in a different theoretical framework and furthermore we give a concrete region where this behavior holds.

  13. Electron Microscope Facility

    ScienceCinema (OSTI)

    None

    2010-01-08T23:59:59.000Z

    Brookhaven Lab is home to one of only a few Scanning Transmision Electron Microscope (STEM) machines in the world and one of the few that can image single heavy atoms.

  14. Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy

    E-Print Network [OSTI]

    Bristol, University of

    .1063/1.3475506 Direct observation of electron emission site on boron-doped polycrystalline diamond thin films using or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force

  15. Imaging and quantitative data acquisition of biological cell walls with Atomic Force Microscopy and Scanning Acoustic Microscopy

    SciTech Connect (OSTI)

    Tittmann, B. R. [Penn State; Xi, X. [Penn State

    2014-09-01T23:59:59.000Z

    This chapter demonstrates the feasibility of Atomic Force Microscopy (AFM) and High Frequency Scanning Acoustic Microscopy (HF-SAM) as tools to characterize biological tissues. Both the AFM and the SAM have shown to provide imaging (with different resolution) and quantitative elasticity measuring abilities. Plant cell walls with minimal disturbance and under conditions of their native state have been examined with these two kinds of microscopy. After descriptions of both the SAM and AFM, their special features and the typical sample preparation is discussed. The sample preparation is focused here on epidermal peels of onion scales and celery epidermis cells which were sectioned for the AFM to visualize the inner surface (closest to the plasma membrane) of the outer epidermal wall. The nm-wide cellulose microfibrils orientation and multilayer structure were clearly observed. The microfibril orientation and alignment tend to be more organized in older scales compared with younger scales. The onion epidermis cell wall was also used as a test analog to study cell wall elasticity by the AFM nanoindentation and the SAM V(z) feature. The novelty in this work was to demonstrate the capability of these two techniques to analyze isolated, single layered plant cell walls in their natural state. AFM nanoindentation was also used to probe the effects of Ethylenediaminetetraacetic acid (EDTA), and calcium ion treatment to modify pectin networks in cell walls. The results suggest a significant modulus increase in the calcium ion treatment and a slight decrease in EDTA treatment. To complement the AFM measurements, the HF-SAM was used to obtain the V(z) signatures of the onion epidermis. These measurements were focused on documenting the effect of pectinase enzyme treatment. The results indicate a significant change in the V(z) signature curves with time into the enzyme treatment. Thus AFM and HF-SAM open the door to a systematic nondestructive structure and mechanical property study of complex biological cell walls. A unique feature of this approach is that both microscopes allow the biological samples to be examined in their natural fluid (water) environment.

  16. The unification of the fundamental interaction within Maxwell electromagnetism: Model of hydrogen atom. Gravity as the secondary electric force. Calculation of the unified inertia force

    E-Print Network [OSTI]

    L. Neslusan

    2010-12-28T23:59:59.000Z

    Considering two static, electrically charged, elementary particles, we demonstrate a possible way of proving that all known fundamental forces in the nature are the manifestations of the single, unique interaction. We re-define the gauging of integration constants in the Schwarzschild solution of Einstein field equations. We consider the potential energy in this context regardless it is gravitational or electric potential energy. With the newly gauged constants, we sketch how the unique interaction can be described with the help of an appropriate solution of the well-known Maxwell equations. According the solution, there are two zones, in the system of two oppositely charged particles, where the force is oscillating. The first particle can be in a stable, constant distance from the second particle, between the neighbouring regions of repulsion and attraction. In an outer oscillation zone, the corresponding energy levels in the proton-electron systems are identical (on the level of accuracy of values calculated by the Dirac's equations) to some experimentally determined levels in the hydrogen atom. For each system of two particles, there is also the zone with the macroscopic, i.e. monotonous behavior of the force. As well, the solution can be used to demonstrate that the net force between two assemblies consisting each (or at least one) of the same numbers of both positively and negatively charged particles is never zero. A secondary electric force, having the same orientation as the primary electric force between the oppositely charged particles, is always present. It can be identified to the gravity. Finally, the solution of the Maxwell equations can be used to calculate the inertia force of a particle. The consistent formulas for both acting and inertia forces enable to construct the dimensionless (without gravitational constant, permitivity of vacuum, etc.) equation of motion.

  17. Nanomechanical and topographical imaging of living cells by Atomic Force Microscopy with colloidal probes

    E-Print Network [OSTI]

    Luca Puricelli; Massimiliano Galluzzi; Carsten Schulte; Alessandro Podestà; Paolo Milani

    2015-02-05T23:59:59.000Z

    Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells' fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cell elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured elastic modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in cell elasticity induced by the action of a cytoskeleton-targeting drug.

  18. Method for measurement of friction forces on single cells in microfluidic devices

    E-Print Network [OSTI]

    Ma, Hongshen

    both dry and wet conditions, are well estab- lished.16,17 The measurement of friction at micrometer the friction between dry microscopic surfaces, including atomic force microscopy, fric- tion-force microscopyMethod for measurement of friction forces on single cells in microfluidic devices Lazar

  19. Atomic force and scanning tunneling microscopy analysis of palladium and silver nanophase materials

    E-Print Network [OSTI]

    Sattler, Klaus

    . INTRODUCTION Nanophase materials consolidated from atom clusters produced by the gas condensation method be made by gas condensation, not only at the labo- ratory scale but also in commercial production and properties of nano- phase materials assembled by consolidating gas-condensed atom clusters in vacuum have

  20. An in-vivo study of electrical charge distribution on the bacterial cell wall by Atomic Force Microscopy in vibrating force mode

    E-Print Network [OSTI]

    Christian Marliere; Samia Dhahri

    2015-04-13T23:59:59.000Z

    We report an in-vivo electromechanical Atomic Force Microscopy (AFM) study of charge distribution on the cell wall of Gram plus Rhodococcus wratislaviensis bacteria, naturally adherent to a glass substrate, in physiological conditions. The method presented in this paper relies on a detailed study of AFM approach-retract curves giving the variation of the interaction force versus distance between tip and sample. In addition to classical height and mechanical (as stiffness) data, mapping of local electrical properties, as bacterial surface charge, was proved to be feasible at a spatial resolution better than few tens of nanometers. This innovative method relies on the measurement of the cantilever's surface stress through its deflection far from (higher than 10nm) the repulsive contact zone. The variations of surface stress come from modification of electrical surface charge of the cantilever (as in classical electrocapillary measurements) likely stemming from its charging during contact of both tip and sample electrical double layers. This method offers an important improvement in local electrical and electrochemical measurements at the solid-liquid interface particularly in high-molarity electrolytes when compared to technics focused on the direct use of electrostatic force. It thus opens a new way to directly investigate in-situ biological electrical surface processes involved in numerous practical and fundamental problems as bacterial adhesion, biofilm formation, microbial fuel cell, etc.

  1. Isolating and moving single atoms using silicon nanocrystals

    DOE Patents [OSTI]

    Carroll, Malcolm S. (Albuquerque, NM)

    2010-09-07T23:59:59.000Z

    A method is disclosed for isolating single atoms of an atomic species of interest by locating the atoms within silicon nanocrystals. This can be done by implanting, on the average, a single atom of the atomic species of interest into each nanocrystal, and then measuring an electrical charge distribution on the nanocrystals with scanning capacitance microscopy (SCM) or electrostatic force microscopy (EFM) to identify and select those nanocrystals having exactly one atom of the atomic species of interest therein. The nanocrystals with the single atom of the atomic species of interest therein can be sorted and moved using an atomic force microscope (AFM) tip. The method is useful for forming nanoscale electronic and optical devices including quantum computers and single-photon light sources.

  2. A microscopic particle-vibration coupling approach for atomic nuclei. Giant resonance properties and the renormalization of the effective interaction

    E-Print Network [OSTI]

    Marco Brenna

    2014-08-01T23:59:59.000Z

    The self-consistent mean-field (SCMF) theory describes many properties of the ground state and excited states of the atomic nucleus, such as masses, radii, deformations and giant resonance energies. SCMF models are based on the independent particle picture where nucleons are assumed to move in a self-generated average potential. In the first part of this work, we apply a state-of-the-art SCMF approach, based on the Skyrme effective interaction, to two different excitations (viz. the pygmy dipole resonance and the isovector giant quadrupole resonance), investigating their relation with the nuclear matter symmetry energy, which corresponds to the energy cost for changing protons into neutrons and is a key parameter for the nuclear equation of state. However, SCMF models present well known limitations which require the inclusion of further dynamical correlations, e.g. the ones coming from the interweaving between single-particle and collective degrees of freedom (particle-vibration coupling - PVC). In the second part of this work, we report on the application to inclusive (namely, the strength function of giant resonances) and exclusive (the gamma decay of giant resonances) observables of a new self-consistent model based on the PVC idea in the Skyrme framework. In our model we use an effective interaction fitted at mean-field level to some selected experimental data. In principle, when these interactions are used in beyond mean-field theories, one would need to re-determine the parameters of the interaction at the same level of approximation. Moreover, due to the zero-range nature of the employed interaction, divergences arise. In the last and most innovative part of this thesis, we develop, for the first time in finite nuclei, a possible way to cure the divergences, paving the way to the possibility of producing an effective interaction fitted at PVC level.

  3. Electrical transport and mechanical properties of alkylsilane self-assembled monolayers on silicon surfaces probed by atomic force microscopy

    SciTech Connect (OSTI)

    Park, Jeong Young; Qi, Yabing; Ashby, Paul D.; Hendriksen, Bas L.M.; Salmeron, Miquel

    2009-02-06T23:59:59.000Z

    The correlation between molecular conductivity and mechanical properties (molecular deformation and frictional responses) of hexadecylsilane self-assembled monolayers was studied with conductive probe atomic force microscopy/friction force microscopy in ultrahigh vacuum. Current and friction were measured as a function of applied pressure, simultaneously, while imaging the topography of self-assembled monolayer molecule islands and silicon surfaces covered with a thin oxide layer. Friction images reveal lower friction over the molecules forming islands than over the bare silicon surface, indicating the lubricating functionality of alkylsilane molecules. By measuring the tunneling current change due to changing of the height of the molecular islands by tilting the molecules under pressure from the tip, we obtained an effective conductance decay constant ({beta}) of 0.52/{angstrom}.

  4. On the use of peak-force tapping atomic force microscopy for quantification of the local elastic modulus in hardened cement paste

    SciTech Connect (OSTI)

    Trtik, Pavel, E-mail: pavel.trtik@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland); Kaufmann, Josef [Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland); Volz, Udo [Bruker Nano GmbH, Mannheim (Germany)

    2012-01-15T23:59:59.000Z

    A surface of epoxy-impregnated hardened cement paste was investigated using a novel atomic force microscopy (AFM) imaging mode that allows for the quantitative mapping of the local elastic modulus. The analyzed surface was previously prepared using focussed ion beam milling. The same surface was also characterized by electron microscopy and energy-dispersive X-ray spectroscopy. We demonstrate the capability of this quantitative nanomechanical mapping to provide information on the local distribution of the elastic modulus (from about 1 to about 100 GPa) with a spatial resolution in the range of decananometers, that corresponds to that of low-keV back-scattered electron imaging. Despite some surface roughness which affects the measured nanomechanical properties it is shown that topography, adhesion and Young's modulus can be clearly distinguished. The quantitative mapping of the local elastic modulus is able to discriminate between phases in the cement paste microstructure that cannot be distinguished from the corresponding back-scattered electron images.

  5. Imaging and measuring the biophysical properties of Fc gamma receptors on single macrophages using atomic force microscopy

    SciTech Connect (OSTI)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China) [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China)] [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China)] [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China)] [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)] [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)] [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-09-06T23:59:59.000Z

    Highlights: •Nanoscale cellular ultra-structures of macrophages were observed. •The binding affinities of Fc?Rs were measured directly on macrophages. •The nanoscale distributions of Fc?Rs were mapped on macrophages. -- Abstract: Fc gamma receptors (Fc?R), widely expressed on effector cells (e.g., NK cells, macrophages), play an important role in clinical cancer immunotherapy. The binding of Fc?Rs to the Fc portions of antibodies that are attached to the target cells can activate the antibody-dependent cell-mediated cytotoxicity (ADCC) killing mechanism which leads to the lysis of target cells. In this work, we used atomic force microscopy (AFM) to observe the cellular ultra-structures and measure the biophysical properties (affinity and distribution) of Fc?Rs on single macrophages in aqueous environments. AFM imaging was used to obtain the topographies of macrophages, revealing the nanoscale cellular fine structures. For molecular interaction recognition, antibody molecules were attached onto AFM tips via a heterobifunctional polyethylene glycol (PEG) crosslinker. With AFM single-molecule force spectroscopy, the binding affinities of Fc?Rs were quantitatively measured on single macrophages. Adhesion force mapping method was used to localize the Fc?Rs, revealing the nanoscale distribution of Fc?Rs on local areas of macrophages. The experimental results can improve our understanding of Fc?Rs on macrophages; the established approach will facilitate further research on physiological activities involved in antibody-based immunotherapy.

  6. Microscope collision protection apparatus

    DOE Patents [OSTI]

    DeNure, Charles R. (Pocatello, ID)

    2001-10-23T23:59:59.000Z

    A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

  7. Focal depth measurement of scanning helium ion microscope

    SciTech Connect (OSTI)

    Guo, Hongxuan, E-mail: Guo.hongxuan@nims.go.jp [Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Itoh, Hiroshi; Wang, Chunmei [Active State Technology Research Group, Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST), 1-1 Umezono 1-Chome, Tsukuba, Ibaraki 305-8568 (Japan); Zhang, Han; Fujita, Daisuke [Nano Characterization Unit, Advanced Key Technologies Division, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-07-14T23:59:59.000Z

    When facing the challenges of critical dimension measurement of complicated nanostructures, such as of the three dimension integrated circuit, characterization of the focal depth of microscopes is important. In this Letter, we developed a method for characterizing the focal depth of a scanning helium ion microscope (HIM) by using an atomic force microscope tip characterizer (ATC). The ATC was tilted in a sample chamber at an angle to the scanning plan. Secondary electron images (SEIs) were obtained at different positions of the ATC. The edge resolution of the SEIs shows the nominal diameters of the helium ion beam at different focal levels. With this method, the nominal shapes of the helium ion beams were obtained with different apertures. Our results show that a small aperture is necessary to get a high spatial resolution and high depth of field images with HIM. This work provides a method for characterizing and improving the performance of HIM.

  8. True atomic-scale imaging of a spinel Li{sub 4}Ti{sub 5}O{sub 12}(111) surface in aqueous solution by frequency-modulation atomic force microscopy

    SciTech Connect (OSTI)

    Kitta, Mitsunori, E-mail: m-kitta@aist.go.jp; Kohyama, Masanori [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Onishi, Hiroshi [Department of Chemistry, Graduate School of Science, Kobe University 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-09-15T23:59:59.000Z

    Spinel-type lithium titanium oxide (LTO; Li{sub 4}Ti{sub 5}O{sub 12}) is a negative electrode material for lithium-ion batteries. Revealing the atomic-scale surface structure of LTO in liquid is highly necessary to investigate its surface properties in practical environments. Here, we reveal an atomic-scale image of the LTO(111) surface in LiCl aqueous solution using frequency-modulation atomic force microscopy. Atomically flat terraces and single steps having heights of multiples of 0.5?nm were observed in the aqueous solution. Hexagonal bright spots separated by 0.6?nm were also observed on the flat terrace part, corresponding to the atomistic contrast observed in the ultrahigh vacuum condition, which suggests that the basic atomic structure of the LTO(111) surface is retained without dramatic reconstruction even in the aqueous solution.

  9. Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P. Rokhinson, Haizhou Yin, D. C. Tsui, and J. C. Sturm

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P features in strained SiGe alloys. When directly oxidizing SiGe alloys, minimum line widths of 20nm were on SiGe alloys is slightly less than that on Si. Finally, this method was used to successfully cut

  10. Effect of plasma CVD operating temperature on nanomechanical properties of TiC nanostructured coating investigated by atomic force microscopy

    SciTech Connect (OSTI)

    Shanaghi, Ali, E-mail: alishanaghi@gmail.com [Materials Engineering Department, Faculty of Engineering, Malayer University, P.O. Box: 95863-65719, Malayer (Iran, Islamic Republic of)] [Materials Engineering Department, Faculty of Engineering, Malayer University, P.O. Box: 95863-65719, Malayer (Iran, Islamic Republic of); Rouhaghdam, Ali Reza Sabour, E-mail: sabour01@modares.ac.ir [Surface Engineering Laboratory, Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Ahangarani, Shahrokh, E-mail: sh.ahangarani@gmail.com [Advanced Materials and Renewable Energies Department, Iranian Research Organization for Science and Technology, P.O. Box 15815-3538, Tehran (Iran, Islamic Republic of)] [Advanced Materials and Renewable Energies Department, Iranian Research Organization for Science and Technology, P.O. Box 15815-3538, Tehran (Iran, Islamic Republic of); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2012-09-15T23:59:59.000Z

    Highlights: ? The TiC{sub x} nanostructure coatings have been deposited by PACVD method. ? Dominant mechanism of growth structure at 490 °C is island-layer type. ? TiC{sub x} nanostructure coating applied at 490 °C, exhibits lowest friction coefficient. ? Young's moduli are 289.9, 400 and 187.6 GPa for 470, 490 and 510 °C, respectively. ? This higher elastic modulus and higher hardness of nanocoating obtain at 490 °C. -- Abstract: The structure, composition, and mechanical properties of nanostructured titanium carbide (TiC) coatings deposited on H{sub 11} hot-working tool steel by pulsed-DC plasma assisted chemical vapor deposition at three different temperatures are investigated. Nanoindentation and nanoscratch tests are carried out by atomic force microscopy to determine the mechanical properties such as hardness, elastic modulus, surface roughness, and friction coefficient. The nanostructured TiC coatings prepared at 490 °C exhibit lower friction coefficient (0.23) than the ones deposited at 470 and 510 °C. Increasing the deposition temperature reduces the Young's modulus and hardness. The overall superior mechanical properties such as higher hardness and lower friction coefficient render the coatings deposited at 490 °C suitable for wear resistant applications.

  11. Calibration of measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy using a contact detection method

    SciTech Connect (OSTI)

    Liu Zhen; Jeong, Younkoo; Menq, Chia-Hsiang [Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2013-02-15T23:59:59.000Z

    An accurate experimental method is proposed for on-spot calibration of the measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy. One of the key techniques devised for this method is a reliable contact detection mechanism that detects the tip-surface contact instantly. At the contact instant, the oscillation amplitude of the tip deflection, converted to that of the deflection signal in laser reading through the measurement sensitivity, exactly equals to the distance between the sample surface and the cantilever base position. Therefore, the proposed method utilizes the recorded oscillation amplitude of the deflection signal and the base position of the cantilever at the contact instant for the measurement sensitivity calibration. Experimental apparatus along with various signal processing and control modules was realized to enable automatic and rapid acquisition of multiple sets of data, with which the calibration of a single dynamic mode could be completed in less than 1 s to suppress the effect of thermal drift and measurement noise. Calibration of the measurement sensitivities of the first and second dynamic modes of three micro-cantilevers having distinct geometries was successfully demonstrated. The dependence of the measurement sensitivity on laser spot location was also experimentally investigated. Finally, an experiment was performed to validate the calibrated measurement sensitivity of the second dynamic mode of a micro-cantilever.

  12. Selection of higher eigenmode amplitude based on dissipated power and virial contrast in bimodal atomic force microscopy

    SciTech Connect (OSTI)

    Diaz, Alfredo J.; Eslami, Babak; López-Guerra, Enrique A.; Solares, Santiago D., E-mail: ssolares@gwu.edu [Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-09-14T23:59:59.000Z

    This paper explores the effect of the amplitude ratio of the higher to the fundamental eigenmode in bimodal atomic force microscopy (AFM) on the phase contrast and the dissipated power contrast of the higher eigenmode. We explore the optimization of the amplitude ratio in order to maximize the type of contrast that is most relevant to the particular study. Specifically, we show that the trends in the contrast range behave differently for different quantities, especially the dissipated power and the phase, with the former being more meaningful than the latter (a similar analysis can be carried out using the virial, for which we also provide a brief example). Our work is based on numerical simulations using two different conservative-dissipative tip-sample models, including the standard linear solid and the combination of a dissipation coefficient with a conservative model, as well as experimental images of thin film Nafion{sup ®} proton exchange polymers. We focus on the original bimodal AFM method, where the higher eigenmode is driven with constant amplitude and frequency (i.e., in “open loop”).

  13. Frequency-modulated atomic force microscopy operation by imaging at the frequency shift minimum: The dip-df mode

    SciTech Connect (OSTI)

    Rode, Sebastian; Schreiber, Martin; Kühnle, Angelika; Rahe, Philipp, E-mail: rahe@uni-mainz.de [Institut für Physikalische Chemie, Fachbereich Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz (Germany)] [Institut für Physikalische Chemie, Fachbereich Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz (Germany)

    2014-04-15T23:59:59.000Z

    In frequency modulated non-contact atomic force microscopy, the change of the cantilever frequency (?f) is used as the input signal for the topography feedback loop. Around the ?f(z) minimum, however, stable feedback operation is challenging using a standard proportional-integral-derivative (PID) feedback design due to the change of sign in the slope. When operated under liquid conditions, it is furthermore difficult to address the attractive interaction regime due to its often moderate peakedness. Additionally, the ?f signal level changes severely with time in this environment due to drift of the cantilever frequency f{sub 0} and, thus, requires constant adjustment. Here, we present an approach overcoming these obstacles by using the derivative of ?f with respect to z as the input signal for the topography feedback loop. Rather than regulating the absolute value to a preset setpoint, the slope of the ?f with respect to z is regulated to zero. This new measurement mode not only makes the minimum of the ?f(z) curve directly accessible, but it also benefits from greatly increased operation stability due to its immunity against f{sub 0} drift. We present isosurfaces of the ?f minimum acquired on the calcite CaCO{sub 3}(101{sup ¯}4) surface in liquid environment, demonstrating the capability of our method to image in the attractive tip-sample interaction regime.

  14. Helium Ion Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Helium Ion Microscope Helium Ion Microscope The Helium Ion Microscope promises to advance biological, geochemical, biogeochemical, and surfaceinterface studies using its combined...

  15. Helium Ion Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Helium Ion Microscope Helium Ion Microscope Bruce Arey discusses the capabilities of EMSL's new helium ion microscope housed in EMSL's Quiet Wing....

  16. Velocity tuning of friction with two trapped atoms

    E-Print Network [OSTI]

    Gangloff, Dorian; Counts, Ian; Jhe, Wonho; Vuleti?, Vladan

    2015-01-01T23:59:59.000Z

    Friction is the basic, ubiquitous mechanical interaction between two surfaces that results in resistance to motion and energy dissipation. In spite of its technological and economic significance, our ability to control friction remains modest, and our understanding of the microscopic processes incomplete. At the atomic scale, mismatch between the two contacting crystal lattices can lead to a reduction of stick-slip friction (structural lubricity), while thermally activated atomic motion can give rise to a complex velocity dependence, and nearly vanishing friction at sufficiently low velocities (thermal lubricity). Atomic force microscopy has provided a wealth of experimental results, but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a full quantitative description from first principles. Here, using an ion-crystal friction emulator with single-atom, single substrate-site spatial resolution and single-slip temporal resolution, we measure the friction force...

  17. Nanometer-scale electrochemical patterning of LiMn2O4 surfaces by an atomic force microscope operating in air

    SciTech Connect (OSTI)

    Kostecki, Robert; Bonhomme, Frederic; Servant, Laurent; Argoul, Francoise; McLarnon, Frank

    2001-06-22T23:59:59.000Z

    Electrochemical nanometer-scale patterning of the surface of a conducting lithium manganese oxide (LiMn{sub 2}O{sub 4}) by scanning probe microscopy (SPM) was studied. The ability to produce nanometer-size patterns of chemically modified oxide or nanometer-sized alterations of the oxide morphology is demonstrated and discussed with reference to possible mechanisms. It is demonstrated that unlike the SPM-based surface oxidation of metals and semiconductors, the LiMn{sub 2}O{sub 4} surface is altered via electrochemically generated species. We show that a localized surface chemical change can be confined to a depth which depends on the oxide-tip voltage difference and ambient humidity. In situ Raman microscopy measurements of localized electrochemical reaction products suggest complex mechanisms of processes induced at the LiMn{sub 2}O{sub 4} surface, such as delithiation through Li-proton exchange and disproportionation of LiMn{sub 2}O{sub 4} to MnO{sub 2} and soluble Mn{sup 2+} species.

  18. Variational Scheme to Compute Protein Reaction Pathways using Atomistic Force Fields with Explicit Solvent

    E-Print Network [OSTI]

    S. a Beccara; L. Fant; P. Faccioli

    2015-02-18T23:59:59.000Z

    We introduce a variational approximation to the microscopic dynamics of rare conformational transitions of macromolecules. Within this framework it is possible to simulate on a small computer cluster reactions as complex as protein folding, using state of the art all-atom force fields in explicit solvent. We test this method against molecular dynamics (MD) simulations of the folding of an alpha- and a beta-protein performed with the same all-atom force field on the Anton supercomputer. We find that our approach yields results consistent with those of MD simulations, at a computational cost orders of magnitude smaller.

  19. Topography, complex refractive index, and conductivity of graphene layers measured by correlation of optical interference contrast, atomic force, and back scattered electron microscopy

    SciTech Connect (OSTI)

    Vaupel, Matthias, E-mail: Matthias.vaupel@zeiss.com; Dutschke, Anke [Training Application Support Center, Carl Zeiss Microscopy GmbH, Königsallee 9-21, 37081 Göttingen (Germany); Wurstbauer, Ulrich; Pasupathy, Abhay [Department of Physics, Columbia University New York, 538 West 120th Street, New York, New York 10027 (United States); Hitzel, Frank [DME Nanotechnologie GmbH, Geysostr. 13, D-38106 Braunschweig (Germany)

    2013-11-14T23:59:59.000Z

    The optical phase shift by reflection on graphene is measured by interference contrast microscopy. The height profile across graphene layers on 300?nm thick SiO{sub 2} on silicon is derived from the phase profile. The complex refractive index and conductivity of graphene layers on silicon with 2?nm thin SiO{sub 2} are evaluated from a phase profile, while the height profile of the layers is measured by atomic force microscopy. It is observed that the conductivity measured on thin SiO{sub 2} is significantly greater than on thick SiO{sub 2}. Back scattered electron contrast of graphene layers is correlated to the height of graphene layers.

  20. Dilution and resonance-enhanced repulsion in nonequilibrium fluctuation forces

    E-Print Network [OSTI]

    Bimonte, Giuseppe

    In equilibrium, forces induced by fluctuations of the electromagnetic field between electrically polarizable objects (microscopic or macroscopic) in vacuum are generically attractive. The force may, however, become repulsive ...

  1. Ultra low-K shrinkage behavior when under electron beam in a scanning electron microscope

    SciTech Connect (OSTI)

    Lorut, F.; Imbert, G. [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France)] [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Roggero, A. [Centre National d'Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)] [Centre National d'Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)

    2013-08-28T23:59:59.000Z

    In this paper, we investigate the tendency of porous low-K dielectrics (also named Ultra Low-K, ULK) behavior to shrink when exposed to the electron beam of a scanning electron microscope. Various experimental electron beam conditions have been used for irradiating ULK thin films, and the resulting shrinkage has been measured through use of an atomic force microscope tool. We report the shrinkage to be a fast, cumulative, and dose dependent effect. Correlation of the shrinkage with incident electron beam energy loss has also been evidenced. The chemical modification of the ULK films within the interaction volume has been demonstrated, with a densification of the layer and a loss of carbon and hydrogen elements being observed.

  2. Study of structural order in porphyrin-fullerene dyad ZnDHD6ee monolayers by electron diffraction and atomic force microscopy

    SciTech Connect (OSTI)

    D'yakova, Yu. A.; Suvorova, E. I.; Orekhov, Andrei S.; Orekhov, Anton S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Alekseev, A. S. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)] [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Gainutdinov, R. V.; Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru; Tereschenko, E. Yu. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Tkachenko, N. V.; Lemmetyinen, H. [Tampere University of Technology (Finland)] [Tampere University of Technology (Finland); Feigin, L. A.; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15T23:59:59.000Z

    The structure of porphyrin-fullerene dyad ZnDHD6ee monolayers formed on the surface of aqueous subphase in a Langmuir trough and transferred onto solid substrates has been studied. The data obtained are interpreted using simulation of the structure of isolated molecules and their packing in monolayer and modeling of diffraction patterns from molecular aggregates having different sizes and degrees of order. Experiments on the formation of condensed ZnDHD6ee monolayers are described. The structure of these monolayers on a water surface is analyzed using {pi}-A isotherms. The structure of the monolayers transferred onto solid substrates is investigated by electron diffraction and atomic force microscopy. The unit-cell parameters of two-dimensional domains, which are characteristic of molecular packing in monolayers and deposited films, are determined. Domains are found to be organized into a texture (the molecular axes are oriented by the [001] direction perpendicular to the substrate). The monolayers contain a limited number of small 3D domains.

  3. Cryogenic immersion microscope

    DOE Patents [OSTI]

    Le Gros, Mark (Berkeley, CA); Larabell, Carolyn A. (Berkeley, CA)

    2010-12-14T23:59:59.000Z

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  4. Characterization of grain boundary conductivity of spin-sprayed ferrites using scanning microwave microscope

    SciTech Connect (OSTI)

    Myers, J.; Nicodemus, T.; Zhuang, Y., E-mail: yan.zhuang@wright.edu [Department of Electrical Engineering, Wright State University, Dayton, Ohio 45435 (United States); Watanabe, T.; Matsushita, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Yamaguchi, M. [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2014-05-07T23:59:59.000Z

    Grain boundary electrical conductivity of ferrite materials has been characterized using scanning microwave microscope. Structural, electrical, and magnetic properties of Fe{sub 3}O{sub 4} spin-sprayed thin films onto glass substrates for different length of growth times were investigated using a scanning microwave microscope, an atomic force microscope, a four-point probe measurement, and a made in house transmission line based magnetic permeameter. The real part of the magnetic permeability shows almost constant between 10 and 300?MHz. As the Fe{sub 3}O{sub 4} film thickness increases, the grain size becomes larger, leading to a higher DC conductivity. However, the loss in the Fe{sub 3}O{sub 4} films at high frequency does not increase correspondingly. By measuring the reflection coefficient s{sub 11} from the scanning microwave microscope, it turns out that the grain boundaries of the Fe{sub 3}O{sub 4} films exhibit higher electric conductivity than the grains, which contributes loss at radio frequencies. This result will provide guidance for further improvement of low loss ferrite materials for high frequency applications.

  5. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    SciTech Connect (OSTI)

    Koffas, Telly Stelianos

    2004-05-15T23:59:59.000Z

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to the surface in order to minimize the total surface energy. With an understanding of the structural and environmental parameters which govern polymer surface structure, SFG is then used to explore the effects of surface hydrophobicity and solvent polarity on the orientation and ordering of amphiphilic neutral polymers adsorbed at the solid/liquid interface. SFG spectra show that poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) adsorb with their hydrophobic moieties preferentially oriented toward hydrophobic polystyrene surfaces. These same moieties, however, disorder when adsorbed onto a hydrophilic silica/water interface. Water is identified as a critical factor for mediating the orientation and ordering of hydrophobic moieties in polymers adsorbed at hydrophobic interfaces. The role of bulk water content and water vapor, as they influence hydrogel surface structure and mechanics, continues to be explored in the next series of experiments. A method was developed to probe the surface viscoelastic properties of hydroxylethyl methacrylate (HEMA) based contact lens materials by analyzing AFM force-distance curves. AFM analysis indicates that the interfacial region is dehydrated, relative to the bulk. Experiments performed on poly(HEMA+MA) (MA = methacrylic acid), a more hydrophilic copolymer with greater bulk water content, show even greater water depletion at the surface. SFG spectra, as well as surface energy arguments, suggest that the more hydrophilic polymer component (such as MA) is not favored at the air interface; this may explain anomalies in water retention at the hydrogel surface. Adsorption of lysozyme onto poly(HEMA+MA) was found to further reduce near-surface viscous behavior, suggesting lower surface water content. Lastly, protein adsorption is studied using a model polymer system of polystyrene covalently bound with a monolayer of bovine serum albumin. SFG results indicate that some amino acid residues in proteins adopt preferred orientations. SFG spectra also show that the phenyl rings of the bare polystyrene substrate in contact with air or

  6. The Microscopic Linear Dynamics

    E-Print Network [OSTI]

    Penny, Will

    The Microscopic Brain Will Penny Linear Dynamics Exponentials Matrix Exponential Eigendecomposition Dynamical Modes Nodes State Space Saddles Oscillations Spirals Centres Offsets Retinal Circuit Nullclines Stability Spiking Neurons Fitzhugh-Nagumo Nonlinear Dynamics Linearization Nonlinear Oscillation Excitable

  7. Infrared microscope inspection apparatus

    DOE Patents [OSTI]

    Forman, S.E.; Caunt, J.W.

    1985-02-26T23:59:59.000Z

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

  8. Resolving three-dimensional shape of sub-50?nm wide lines with nanometer-scale sensitivity using conventional optical microscopes

    SciTech Connect (OSTI)

    Attota, Ravikiran, E-mail: Ravikiran.attota@nist.gov; Dixson, Ronald G. [Semiconductor and Dimensional Metrology Division, NIST, Gaithersburg, Maryland 20899 (United States)

    2014-07-28T23:59:59.000Z

    We experimentally demonstrate that the three-dimensional (3-D) shape variations of nanometer-scale objects can be resolved and measured with sub-nanometer scale sensitivity using conventional optical microscopes by analyzing 4-D optical data using the through-focus scanning optical microscopy (TSOM) method. These initial results show that TSOM-determined cross-sectional (3-D) shape differences of 30?nm–40?nm wide lines agree well with critical-dimension atomic force microscope measurements. The TSOM method showed a linewidth uncertainty of 1.22?nm (k?=?2). Complex optical simulations are not needed for analysis using the TSOM method, making the process simple, economical, fast, and ideally suited for high volume nanomanufacturing process monitoring.

  9. Fast scanning mode and its realization in a scanning acoustic microscope

    SciTech Connect (OSTI)

    Ju Bingfeng; Bai Xiaolong; Chen Jian [The State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027 (China)

    2012-03-15T23:59:59.000Z

    The scanning speed of the two-dimensional stage dominates the efficiency of mechanical scanning measurement systems. This paper focused on a detailed scanning time analysis of conventional raster and spiral scan modes and then proposed two fast alternative scanning modes. Performed on a self-developed scanning acoustic microscope (SAM), the measured images obtained by using the conventional scan mode and fast scan modes are compared. The total scanning time is reduced by 29% of the two proposed fast scan modes. It will offer a better solution for high speed scanning without sacrificing the system stability, and will not introduce additional difficulties to the configuration of scanning measurement systems. They can be easily applied to the mechanical scanning measuring systems with different driving actuators such as piezoelectric, linear motor, dc motor, and so on. The proposed fast raster and square spiral scan modes are realized in SAM, but not specially designed for it. Therefore, they have universal adaptability and can be applied to other scanning measurement systems with two-dimensional mechanical scanning stages, such as atomic force microscope or scanning tunneling microscope.

  10. Electron microscope studies

    SciTech Connect (OSTI)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01T23:59:59.000Z

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  11. ORNL researchers make first observation of atoms moving inside...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    observation of atoms moving inside bulk material Selected frames from a sequence of scanning transmission electron microscope images showing the diffusion pathway of a Ce dopant...

  12. PAPER www.rsc.org/loc | Lab on a Chip Open micro-fluidic system for atomic force microscopy-guided in situ

    E-Print Network [OSTI]

    by light harvesting complexes, which funnel that energy into the reaction centers of the photosynthetic electron transport chain, causing a charge separation that provides the driving force to split water cells and has the potential to be exploited by direct extraction of energetic electrons from

  13. Acoustic imaging microscope

    DOE Patents [OSTI]

    Deason, Vance A.; Telschow, Kenneth L.

    2006-10-17T23:59:59.000Z

    An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

  14. Experimental Free Energy Surface Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality

    E-Print Network [OSTI]

    Nolan C. Harris; Yang Song; Ching-Hwa Kiang

    2007-07-03T23:59:59.000Z

    We used the atomic force microscope to manipulate and unfold individual molecules of the titin I27 domain and reconstructed its free energy surface using Jarzynski's equality. The free energy surface for both stretching and unfolding was reconstructed using an exact formula that relates the nonequilibrium work fluctuations to the molecular free energy. In addition, the unfolding free energy barrier, i.e. the activation energy, was directly obtained from experimental data for the first time. This work demonstrates that Jarzynski's equality can be used to analyze nonequilibrium single-molecule experiments, and to obtain the free energy surfaces for molecular systems, including interactions for which only nonequilibrium work can be measured.

  15. Light-induced gauge fields for ultracold atoms

    E-Print Network [OSTI]

    N. Goldman; G. Juzeliunas; P. Ohberg; I. B. Spielman

    2014-12-12T23:59:59.000Z

    Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our universe is ruled by gravity, whose gauge structure suggests the existence of a particle - the graviton - that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms "feeling" laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials - both Abelian and non-Abelian - in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.

  16. Climate forcing Climate forcing

    E-Print Network [OSTI]

    MacKinnon, Jennifer

    parameters (solar distance factors) solar luminosity moon orbit volcanoes and other geothermal sources,000 years (large panels) and since 1750 (inset panels). Measurements are shown from ice cores (symbols forcings are shown on the right hand axes of the large panels. {Figure 6.4} !"#$#%&'(!&#)$&*$+#$,-.$/0

  17. Femtosecond photoelectron point projection microscope

    SciTech Connect (OSTI)

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett [Department of Physics, Trinity College, 300 Summit St., Hartford, Connecticut 06106 (United States)] [Department of Physics, Trinity College, 300 Summit St., Hartford, Connecticut 06106 (United States)

    2013-10-15T23:59:59.000Z

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  18. Transmission electron microscope CCD camera

    DOE Patents [OSTI]

    Downing, Kenneth H. (Lafayette, CA)

    1999-01-01T23:59:59.000Z

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  19. Metal atomization spray nozzle

    DOE Patents [OSTI]

    Huxford, T.J.

    1993-11-16T23:59:59.000Z

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  20. Nonlocal microscopic theory of Casimir forces at finite temperature

    SciTech Connect (OSTI)

    Despoja, V. [Donostia International Physics Center (DIPC), P. Manuel de Lardizabal, ES-20018 San Sebastian, Basque Country (Spain); Department of Physics, University of Zagreb, Bijenicka 32, HR-10000 Zagreb (Croatia); Depto. de Fysica de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Quimicas, Universidad del Pays Vasco, Apdo. 1072, E-20018 San Sebastian (Spain); Sunjic, M. [Donostia International Physics Center (DIPC), P. Manuel de Lardizabal, ES-20018 San Sebastian, Basque Country (Spain); Department of Physics, University of Zagreb, Bijenicka 32, HR-10000 Zagreb (Croatia); Marusic, L. [Maritime Department, University of Zadar, M. Pavlinovica b.b., HR-23000 Zadar (Croatia)

    2011-04-15T23:59:59.000Z

    The interaction energy between two metallic slabs in the retarded limit at finite temperature is expressed in terms of surface polariton propagators for separate slabs, avoiding the usual matching procedure, with both diamagnetic and paramagnetic excitations included correctly. This enables appropriate treatment of arbitrary electron density profiles and fully nonlocal electronic response, including both collective and single-particle excitations. The results are verified by performing the nonretarded and long-wavelength (local) limits and showing that they reduce to the previously obtained expressions. Possibilities for practical use of the theory are explored by applying it to calculation of various contributions to the Casimir energy between two silver slabs.

  1. Design and construction of a magnetic force microscope

    E-Print Network [OSTI]

    Khandekar, Sameer Sudhakar

    2005-08-29T23:59:59.000Z

    Nanotec Electronica, Spain. Fig. 6 shows the MFM images of two different hard disks. The difference in the size of the magnetic domains is evident in this case with the new hard disk having smaller domain size and the old hard disk having the larger...

  2. Multi-dimensional modelling of electrostatic force distance curve over dielectric surface: Influence of tip geometry and correlation with experiment

    SciTech Connect (OSTI)

    Boularas, A., E-mail: boularas@laplace.univ-tlse.fr; Baudoin, F.; Villeneuve-Faure, C. [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, 31062 Toulouse cedex 9 (France); Clain, S. [Universidade do Minho, Centro de Matemática, Campus de Gualtar, 4710 - 057 Braga (Portugal); Université Paul Sabatier, Institut de Mathématiques de Toulouse, 31062 Toulouse (France); Teyssedre, G. [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, 31062 Toulouse cedex 9 (France); CNRS, LAPLACE, F-31071 Toulouse (France)

    2014-08-28T23:59:59.000Z

    Electric Force-Distance Curves (EFDC) is one of the ways whereby electrical charges trapped at the surface of dielectric materials can be probed. To reach a quantitative analysis of stored charge quantities, measurements using an Atomic Force Microscope (AFM) must go with an appropriate simulation of electrostatic forces at play in the method. This is the objective of this work, where simulation results for the electrostatic force between an AFM sensor and the dielectric surface are presented for different bias voltages on the tip. The aim is to analyse force-distance curves modification induced by electrostatic charges. The sensor is composed by a cantilever supporting a pyramidal tip terminated by a spherical apex. The contribution to force from cantilever is neglected here. A model of force curve has been developed using the Finite Volume Method. The scheme is based on the Polynomial Reconstruction Operator—PRO-scheme. First results of the computation of electrostatic force for different tip–sample distances (from 0 to 600?nm) and for different DC voltages applied to the tip (6 to 20?V) are shown and compared with experimental data in order to validate our approach.

  3. Dual harmonic Kelvin probe force microscopy at the graphene–liquid interface

    SciTech Connect (OSTI)

    Collins, Liam; Rodriguez, Brian J., E-mail: brian.rodriguez@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Kilpatrick, Jason I.; Weber, Stefan A. L. [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Vlassiouk, Ivan V. [Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Tselev, Alexander; Jesse, Stephen; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-03-31T23:59:59.000Z

    Kelvin probe force microscopy (KPFM) is a powerful technique for the determination of the contact potential difference (CPD) between an atomic force microscope tip and a sample under ambient and vacuum conditions. However, for many energy storage and conversion systems, including graphene-based electrochemical capacitors, understanding electrochemical phenomena at the solid–liquid interface is paramount. Despite the vast potential to provide fundamental insight for energy storage materials at the nanoscale, KPFM has found limited applicability in liquid environments to date. Here, using dual harmonic (DH)-KPFM, we demonstrate CPD imaging of graphene in liquid. We find good agreement with measurements performed in air, highlighting the potential of DH-KPFM to probe electrochemistry at the graphene–liquid interface.

  4. Sensing Current and Forces with SPM

    SciTech Connect (OSTI)

    Park, Jeong Y.; Maier, Sabine; Hendriksen, Bas; Salmeron, Miquel

    2010-07-02T23:59:59.000Z

    Atomic force microscopy (AFM) and scanning tunneling microscopy (STM) are well established techniques to image surfaces and to probe material properties at the atomic and molecular scale. In this review, we show hybrid combinations of AFM and STM that bring together the best of two worlds: the simultaneous detection of atomic scale forces and conduction properties. We illustrate with several examples how the detection of forces during STM and the detection of currents during AFM can give valuable additional information of the nanoscale material properties.

  5. Atomic force microscopy and x-ray photoelectron spectroscopy investigations of the morphology and chemistry of a PdCl{sub 2}/SnCl{sub 2} electroless plating catalysis system adsorbed onto shape memory alloy particles

    SciTech Connect (OSTI)

    Silvain, J.F.; Fouassier, O.; Lescaux, S. [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB) - CNRS, Universite de Bordeaux 1, 87 Avenue du Dr A. Schweitzer, F-33608 PESSAC (France); Veeco, Z.I. de la Gaudree, 11 Rue Marie Poussepin, F-91412 Dourdain (France)

    2004-11-01T23:59:59.000Z

    A study of the different stages of the electroless deposition of copper on micronic NiTi shape memory alloy particles activated by one-step and two-step methods has been conducted from both a chemical and a morphological point of view. The combination of x-ray photoelectron spectroscopy (XPS) measurements and atomic force microscopy (AFM) imaging has allowed detection of the distribution of the formed compounds and depth quantification and estimation of the surface topographic parameters. For the two-step method, at the sensitization of the early stages, it is observed by AFM that Sn is absorbed in form of clusters that tend to completely cover the surface and form a continuous film. XPS analysis have shown that Sn and Pd are first absorbed in form of oxide (SnO{sub 2} and PdO) and hydroxide [Sn(OH){sub 4}]. After the entire sensitization step, the NiTi substrate is covered with Sn-based compounds. After the sensitization and the activation steps the powder roughness increases. Behavior of the Sn and Pd growth for the one-step method does not follow the behavior found for the two-step method. Indeed, XPS analysis shows a three-dimensional (3D) growth of Pd clusters on top of a mixture of metallic tin, oxide (SnO) and hydroxide [Sn(OH){sub 2}]. These Pd clusters are covered with a thin layer of Pd-oxide contamination induced by the electroless process. The mean roughness for the one-step and two-step processes are equivalent. After copper deposition, the decrease of mean roughness is attributed to a filling of surface valleys, observed after the Sn-Pd coating step.

  6. Polymer Filler Aging and Failure Studied by Lateral Force Microscopy

    SciTech Connect (OSTI)

    Ratto, T; Saab, A P

    2009-05-27T23:59:59.000Z

    In the present work, we study, via force microscopy, the basic physical interactions of a single bead of silica filler with a PDMS matrix both before and after exposure to gamma radiation. Our goal was to confirm our results from last year, and to explore force microscopy as a means of obtaining particle-scale polymer/filler interactions suitable for use as empirical inputs to a computational model consisting of an ensemble of silica beads embedded in a PDMS matrix. Through careful calibration of a conventional atomic force microscope, we obtained both normal and lateral force data that was fitted to yield adhesion, surface shear modulus, and friction of a 1 {micro}m silica bead in contact with PDMS layers of various thickness. Comparison of these terms before and after gamma exposure indicated that initially, radiation exposure lead to softening of the PDMS, but eventually resulted in stiffening. Simultaneously, adhesion between the polymer and silica decreased. This could indicate a serious failure path for filled PDMS exposed to radiation, whereby stiffening of the bulk polymer leads to loss of compressive elastic behavior, while a decrease in polymer filler adhesion results in an increased likelihood of stress failure under load. In addition to further testing of radiation damaged polymers, we also performed FEA modeling of silica beads in a silicone matrix using the shear modulus and adhesion values isolated from the force microscopy experiments as model inputs. The resulting simulation indicated that as a polymer stiffens due to impinging radiation, it also undergoes weakening of adhesion to the filler. The implication is that radiation induces a compound failure mode in filled polymer systems.

  7. Correlation between fundamental binding forces and clinical prognosis...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic force microscopy was used to “fish” for binding reactions between a fibronectin-coated probe (i.e., substrate simulating an implant device) and each of 15...

  8. Long working distance interference microscope

    DOE Patents [OSTI]

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13T23:59:59.000Z

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  9. Scanning tunneling microscope nanoetching method

    DOE Patents [OSTI]

    Li, Yun-Zhong (West Lafayette, IN); Reifenberger, Ronald G. (West Lafayette, IN); Andres, Ronald P. (West Lafayette, IN)

    1990-01-01T23:59:59.000Z

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  10. Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-08-26T23:59:59.000Z

    Establishes requirements for management and operation of the DOE Protective Force (PF), establishes requirements for firearms operations and defines the firearms courses of fire. Cancels: DOE M 473.2-1A DOE M 473.2-2

  11. Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-03-07T23:59:59.000Z

    The manual establishes requirements for management and operation of the DOE Protective Force, establishes requirements for firearms operations and defines the firearms courses of fire. Chg 1 dated 3/7/06. DOE M 470.4-3A cancels DOE M 470.4-3, Chg 1, Protective Force, dated 3-7-06, Attachment 2, Contractor Requirement Document (CRD) only (except for Section C). Chg 1, dated 3-7-06, cancels DOE M 470.4-3

  12. Casimir forces

    E-Print Network [OSTI]

    S. Reynaud; A. Lambrecht

    2014-10-10T23:59:59.000Z

    The present notes are organized as the lectures given at the Les Houches Summer School "Quantum Optics and Nanophotonics" in August 2013. The first section contains an introduction and a description of the current state-of-the-art for Casimir force measurements and their comparison with theory. The second and third sections are a pedagogical presentation of the main features of the theory of Casimir forces for 1-dimensional model systems and for mirrors in 3-dimensional space.

  13. atomic orbitals calculation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and...

  14. atomic structure calculations: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and...

  15. Optical modeling of Fresnel zoneplate microscopes

    E-Print Network [OSTI]

    Naulleau, Patrick

    2012-01-01T23:59:59.000Z

    of 12 nm Resolution Fresnel Zone Plate Lens based Soft X-rayOptical modeling of Fresnel zoneplate microscopes Patrick P.the development of Fresnel zoneplate based microscopes.

  16. Investigation on dielectric properties of atomic layer deposited Al{sub 2}O{sub 3} dielectric films

    SciTech Connect (OSTI)

    Y?ld?z, Dilber Esra [Department of Physics, Faculty of Arts and Sciences, Hitit University, Çorum 19030 (Turkey); Y?ld?r?m, Mert; Gökçen, Muharrem [Department of Physics, Faculty of Arts and Sciences, Düzce University, Düzce 81620 (Turkey)

    2014-05-15T23:59:59.000Z

    Al/Al{sub 2}O{sub 3}/p-Si Schottky barrier diodes (SBDs) were fabricated using atomic layer deposition technique in order to investigate dielectric properties of SBDs. For this purpose, admittance measurements were conducted at room temperature between ?1?V and 3?V in the frequency range of 10 kHz and 1?MHz. In addition to the investigation of Al{sub 2}O{sub 3} morphology using atomic force microscope, dielectric parameters; such as dielectric constant (??), dielectric loss (??), dielectric loss tangent (tan??), and real and imaginary parts of dielectric modulus (M? and M?, respectively), were calculated and effect of frequency on these parameters of Al/Al{sub 2}O{sub 3}/p-Si SBDs was discussed. Variations in these parameters at low frequencies were associated with the effect of interface states in low frequency region. Besides dielectric parameters, ac electrical conductivity of these SBDs was also investigated.

  17. Nuclear forces from chiral EFT: The unfinished business

    E-Print Network [OSTI]

    R. Machleidt; D. R. Entem

    2010-01-06T23:59:59.000Z

    In spite of the great progress we have seen in recent years in the derivation of nuclear forces from chiral effective field theory (EFT), some important issues are still unresolved. In this contribution, we discuss the open problems which have particular relevance for microscopic nuclear structure, namely, the proper renormalization of chiral nuclear potentials and sub-leading many-body forces.

  18. Scanning/Transmission Electron Microscopes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclearHomeland andEffectsScanning/Transmission Electron Microscopes

  19. The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics Laboratory

    E-Print Network [OSTI]

    Berggren, Karl K.

    The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics physics laboratory, the SEM is an excellent substitute for an ion accelerator. Although for experimental work on accelerator physics, atomic physics, electron-solid interactions, and the basics of modern

  20. Tracking a nanosize magnetic particle using a magnetic force Dimitar Baronov, Sean B. Andersson and John Baillieul

    E-Print Network [OSTI]

    Andersson, Sean B.

    Tracking a nanosize magnetic particle using a magnetic force microscope Dimitar Baronov, Sean B. Andersson and John Baillieul Abstract-- A scheme for tracking nano-sized magnetic par- ticles using a magnetic force microscope (MFM) is introduced. The stray magnetic field of the particle induces a shift

  1. Gain narrowing in few-atom systems

    E-Print Network [OSTI]

    Tom Savels; Allard P. Mosk; Ad Lagendijk

    2006-05-31T23:59:59.000Z

    Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near-field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation.

  2. STORM/PALM - Super Resolution Fluorescence Microscope | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    STORMPALM - Super Resolution Fluorescence Microscope STORMPALM - Super Resolution Fluorescence Microscope EMSL has developed and offers Fluorescence, Super Resolution STORM...

  3. Lift Forces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5Let us count theLienertLift Forces in Bubbly

  4. Nanomaterials Analysis using a Scanning Electron Microscope ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nanomaterials Analysis using a Scanning Electron Microscope Technology available for licensing: Steradian X-ray detection system increases the detection capability of SEMs during...

  5. Scanning evanescent electro-magnetic microscope

    DOE Patents [OSTI]

    Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Anhui, CN); Schultz, Peter G. (La Jolla, CA); Wei, Tao (Sunnyvale, CA)

    2003-01-01T23:59:59.000Z

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  6. Scanning evanescent electro-magnetic microscope

    DOE Patents [OSTI]

    Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Alameda, CA)

    2001-01-01T23:59:59.000Z

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  7. If Only We Could Account For Every Atom (LBNL Summer Lecture Series)

    ScienceCinema (OSTI)

    Kisielowski, Christian

    2014-05-06T23:59:59.000Z

    Christian Kisielowski, an expert in electron microscopy at Lawrence Berkeley National Laboratory, investigates ways to allow studies of single atoms using sophisticated microscopes and imaginative techniques. His goal is to account for every atom in the interior of both simple and complex materials. Find out how he and his colleagues are breaking the barriers to account for every atom.

  8. Radiative friction on an excited atom moving in vacuum

    E-Print Network [OSTI]

    Wei Guo

    2012-04-30T23:59:59.000Z

    It is known that, when an excited atom spontaneously emits one photon, two effects are produced. First, the atom's internal and external states are entangled with the states of the emitted photon. Second, the atom receives a momentum transfered from the photon. In this work, the dynamics of such an atom in vacuum is studied. Through a specific calculation, it is demonstrated that these effects cause the atom to experience, on average, a friction force opposite to its initial velocity. Properties of the force are also discussed.

  9. Classical Helium Atom with Radiation Reaction G. Camelio,1

    E-Print Network [OSTI]

    Carati, Andrea

    Classical Helium Atom with Radiation Reaction G. Camelio,1 A. Carati,2 and L. Galgani2 1) Universit November 2011) We study a classical model of Helium atom in which, in addition to the Coulomb forces be singular with respect to that of Lebesgue. PACS numbers: 05.45.-a, 41.60.-m Keywords: classical Helium atom

  10. Atom Interferometry

    ScienceCinema (OSTI)

    Mark Kasevich

    2010-01-08T23:59:59.000Z

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  11. Robotic CCD microscope for enhanced crystal recognition

    DOE Patents [OSTI]

    Segelke, Brent W. (San Ramon, CA); Toppani, Dominique (Livermore, CA)

    2007-11-06T23:59:59.000Z

    A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

  12. Note: Long-range scanning tunneling microscope for the study of nanostructures on insulating substrates

    SciTech Connect (OSTI)

    Molina-Mendoza, Aday J., E-mail: aday.molina@uam.es [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Rodrigo, José G.; Rubio-Bollinger, Gabino [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales “Nicolás Cabrera,” Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Island, Joshua; Burzuri, Enrique; Zant, Herre S. J. van der [Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Agraït, Nicolás [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain) [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC) and Instituto Universitario de Ciencia de Materiales “Nicolás Cabrera,” Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid (Spain)

    2014-02-15T23:59:59.000Z

    The scanning tunneling microscope (STM) is a powerful tool for studying the electronic properties at the atomic level, however, it is of relatively small scanning range and the fact that it can only operate on conducting samples prevents its application to study heterogeneous samples consisting of conducting and insulating regions. Here we present a long-range scanning tunneling microscope capable of detecting conducting micro and nanostructures on insulating substrates using a technique based on the capacitance between the tip and the sample and performing STM studies.

  13. Microscopic origin of granular ratcheting

    E-Print Network [OSTI]

    S. McNamara; R. García-Rojo; H. J. Herrmann

    2007-08-10T23:59:59.000Z

    Numerical simulations of assemblies of grains under cyclic loading exhibit ``granular ratcheting'': a small net deformation occurs with each cycle, leading to a linear accumulation of deformation with cycle number. We show that this is due to a curious property of the most frequently used models of the particle-particle interaction: namely, that the potential energy stored in contacts is path-dependent. There exist closed paths that change the stored energy, even if the particles remain in contact and do not slide. An alternative method for calculating the tangential force removes granular ratcheting.

  14. Classical and Quantum Chaos in Atom Optics

    E-Print Network [OSTI]

    Farhan Saif

    2006-04-10T23:59:59.000Z

    The interaction of an atom with an electromagnetic field is discussed in the presence of a time periodic external modulating force. It is explained that a control on atom by electromagnetic fields helps to design the quantum analog of classical optical systems. In these atom optical systems chaos may appear at the onset of external fields. The classical and quantum chaotic dynamics is discussed, in particular in an atom optics Fermi accelerator. It is found that the quantum dynamics exhibits dynamical localization and quantum recurrences.

  15. Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells

    E-Print Network [OSTI]

    Fisher, Frank

    Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells., University of Pittsburgh The most efficient organic solar cell today is made from blending conjugated donors and acceptors in bulk heterojunction organic solar cells. Most microscopic characterization

  16. WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

    SciTech Connect (OSTI)

    Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

    2003-02-01T23:59:59.000Z

    The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying wetting at microscopic and macroscopic scales and a library of well-characterized fluids for use in studies of crude oil/brine/rock interactions.

  17. Measuring Atomic Properties with an Atom Interferometer

    E-Print Network [OSTI]

    Roberts, Tony David

    2006-06-28T23:59:59.000Z

    Two experiments are presented which measure atomic properties using an atom interferometer. The interferometer splits the sodium de Broglie wave into two paths,

  18. HRTEM Imaging of Atoms at Sub-Angstrom Resolution

    SciTech Connect (OSTI)

    O'Keefe, Michael A.; Allard, Lawrence F.; Blom, Douglas A.

    2005-04-06T23:59:59.000Z

    John Cowley and his group at Arizona State University pioneered the use of transmission electron microscopy (TEM) for high-resolution imaging. Images were achieved three decades ago showing the crystal unit cell content at better than 4 Angstrom resolution. This achievement enabled researchers to pinpoint the positions of heavy atom columns within the unit cell. Lighter atoms appear as resolution is improved to sub-Angstrom levels. Currently, advanced microscopes can image the columns of the light atoms (carbon, oxygen, nitrogen) that are present in many complex structures, and even the lithium atoms present in some battery materials. Sub-Angstrom imaging, initially achieved by focal-series reconstruction of the specimen exit surface wave, will become common place for next-generation electron microscopes with CS-corrected lenses and monochromated electron beams. Resolution can be quantified in terms of peak separation and inter-peak minimum, but the limits imposed on the attainable resolution by the properties of the micro-scope specimen need to be considered. At extreme resolution the ''size'' of atoms can mean that they will not be resolved even when spaced farther apart than the resolution of the microscope.

  19. A New Interpretation of the Scanning Tunneling Microscope Image...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Interpretation of the Scanning Tunneling Microscope Image of Graphite. A New Interpretation of the Scanning Tunneling Microscope Image of Graphite. Abstract: In this work,...

  20. CFN | Hitachi HD2700C Scanning Transmission Electron Microscope

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hitachi HD2700C Scanning Transmission Electron Microscope Contacts: Dong Su | Lihua Zhang | Huolin Xin The Hitachi 2700C is a dedicated Scanning Transmission Electron Microscope...

  1. X-ray laser microscope apparatus

    DOE Patents [OSTI]

    Suckewer, Szymon (Princeton, NJ); DiCicco, Darrell S. (Plainsboro, NJ); Hirschberg, Joseph G. (Coral Gables, FL); Meixler, Lewis D. (East Windsor, NJ); Sathre, Robert (Princeton, NJ); Skinner, Charles H. (Lawrenceville, NJ)

    1990-01-01T23:59:59.000Z

    A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

  2. Microscopic calculation of the spin-dependent neutron scattering lengths on 3He

    E-Print Network [OSTI]

    H. M. Hofmann; G. M. Hale

    2003-04-16T23:59:59.000Z

    We report on the spin.dependent neutron scattering length on 3He from a microscopic calculation of p-3H, n-3He, and d-2H scattering employing the Argonne v18 nucleon-nucleon potential with and without additional three-nucleon force. The results and that of a comprehensive R-matrix analysis are compared to a recent measurement. The overall agreement for the scattering lengths is quite good. The imaginary parts of the scattering lengths are very sensitive to the inclusion of three-nucleon forces, whereas the real parts are almost insensitive.

  3. Miniature self-contained vacuum compatible electronic imaging microscope

    DOE Patents [OSTI]

    Naulleau, Patrick P. (Oakland, CA); Batson, Phillip J. (Alameda, CA); Denham, Paul E. (Crockett, CA); Jones, Michael S. (San Francisco, CA)

    2001-01-01T23:59:59.000Z

    A vacuum compatible CCD-based microscopic camera with an integrated illuminator. The camera can provide video or still feed from the microscope contained within a vacuum chamber. Activation of an optional integral illuminator can provide light to illuminate the microscope subject. The microscope camera comprises a housing with a objective port, modified objective, beam-splitter, CCD camera, and LED illuminator.

  4. Atomic magnetometer

    DOE Patents [OSTI]

    Schwindt, Peter (Albuquerque, NM); Johnson, Cort N. (Albuquerque, NM)

    2012-07-03T23:59:59.000Z

    An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

  5. Apparatus for imaging liquid and dielectric materials with scanning polarization force microscopy

    DOE Patents [OSTI]

    Hu, Jun (Berkeley, CA); Ogletree, D. Frank (El Cerrito, CA); Salmeron, Miguel (El Cerrito, CA); Xiao, Xudong (Kowloon, CN)

    1998-01-01T23:59:59.000Z

    The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

  6. Method for imaging liquid and dielectric materials with scanning polarization force microscopy

    DOE Patents [OSTI]

    Hu, Jun (Berkeley, CA); Ogletree, D. Frank (El Cerrito, CA); Salmeron, Miguel (El Cerrito, CA); Xiao, Xudong (Kowloon, CN)

    1999-01-01T23:59:59.000Z

    The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

  7. Laser damage properties of TiO{sub 2}/Al{sub 2}O{sub 3} thin films grown by atomic layer deposition

    SciTech Connect (OSTI)

    Wei Yaowei; Liu Hao; Sheng Ouyang; Liu Zhichao; Chen Songlin; Yang Liming

    2011-08-20T23:59:59.000Z

    Research on thin film deposited by atomic layer deposition (ALD) for laser damage resistance is rare. In this paper, it has been used to deposit TiO{sub 2}/Al{sub 2}O{sub 3} films at 110 deg. C and 280 deg. C on fused silica and BK7 substrates. Microstructure of the thin films was investigated by x-ray diffraction. The laser-induced damage threshold (LIDT) of samples was measured by a damage test system. Damage morphology was studied under a Nomarski differential interference contrast microscope and further checked under an atomic force microscope. Multilayers deposited at different temperatures were compared. The results show that the films deposited by ALD had better uniformity and transmission; in this paper, the uniformity is better than 99% over 100 mm {Phi} samples, and the transmission is more than 99.8% at 1064 nm. Deposition temperature affects the deposition rate and the thin film microstructure and further influences the LIDT of the thin films. As to the TiO{sub 2}/Al{sub 2}O{sub 3} films, the LIDTs were 6.73{+-}0.47 J/cm{sup 2} and 6.5{+-}0.46 J/cm{sup 2} at 110 deg. C on fused silica and BK7 substrates, respectively. The LIDTs at 110 deg. C are notably better than 280 deg. C.

  8. Microscopic model of a phononic refrigerator

    E-Print Network [OSTI]

    Liliana Arrachea; Eduardo Mucciolo; Claudio Chamon; Rodrigo Capaz

    2012-11-05T23:59:59.000Z

    We analyze a simple microscopic model to pump heat from a cold to a hot reservoir in a nanomechanical system. The model consists of a one-dimensional chain of masses and springs coupled to a back gate through which a time-dependent perturbation is applied. The action of the gate is to modulate the coupling of the masses to a substrate via additional springs that introduce a moving phononic barrier. We solve the problem numerically using non-equilibrium Green function techniques. For low driving frequencies and for sharp traveling barriers, we show that this microscopic model realizes a phonon refrigerator.

  9. Instead of splitting the atom --the

    E-Print Network [OSTI]

    gravitational forces ram hydrogen atoms together to produce helium, with solar energy the byproduct. On Earth -- with helium as the waste product in addition to the energy. A huge jolt of heat (to nearly 100 million C, 180 million F) would kickstart the process, fusing the nuclei in a charged gas called a plasma. Plasma has

  10. SLAC All Access: X-ray Microscope

    ScienceCinema (OSTI)

    Nelson, Johanna; Liu, Yijin

    2014-06-13T23:59:59.000Z

    SLAC physicists Johanna Nelson and Yijin Liu give a brief overview of the X-ray microscope at the Stanford Synchrotron Radiation Lightsource (SSRL) that is helping improve rechargeable-battery technology by letting researchers peek into the inner workings of batteries as they operate.

  11. Vertically aligned nanostructure scanning probe microscope tips

    DOE Patents [OSTI]

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19T23:59:59.000Z

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  12. Superconducting qubit as a quantum transformer routing entanglement between a microscopic quantum memory and a macroscopic resonator

    SciTech Connect (OSTI)

    Kemp, Alexander; Saito, Shiro; Semba, Kouichi [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya Atsugi-shi, Kanagawa 243-0198 (Japan); Munro, William J. [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya Atsugi-shi, Kanagawa 243-0198 (Japan); National Institute of Informatics 2-1-2 Hitotsubashi, Chiyoda ku, Tokyo 101-8430 (Japan); Nemoto, Kae [National Institute of Informatics 2-1-2 Hitotsubashi, Chiyoda ku, Tokyo 101-8430 (Japan)

    2011-09-01T23:59:59.000Z

    We demonstrate experimentally the creation and measurement of an entangled state between a microscopic two-level system (TLS), formed by a defect in an oxide layer, and a macroscopic superconducting resonator, where their indirect interaction is mediated by an artificial atom, a superconducting persistent current qubit (PCQB). Under appropriate conditions, we found the coherence time of the TLS, the resonator, and the entangled state of these two are significantly longer than the Ramsey dephasing time of PCQB itself. This demonstrates that a PCQB can be used as a quantum transformer to address high coherence microscopic quantum memories by connecting them to macroscopic quantum buses.

  13. Three-Nucleon Forces

    E-Print Network [OSTI]

    Peter U. Sauer

    2014-07-25T23:59:59.000Z

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

  14. Protective Force Program Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2000-06-30T23:59:59.000Z

    Provides detailed requirements to supplement DOE O 473.2, Protective Force Program, which establishes the requirements and responsibilities for management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Does not cancel other directives.

  15. Graphene thickness dependent adhesion force and its correlation to surface roughness

    SciTech Connect (OSTI)

    Pourzand, Hoorad [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Tabib-Azar, Massood, E-mail: azar.m@utah.edu [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Biomedical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

    2014-04-28T23:59:59.000Z

    In this paper, adhesion force of graphene layers on 300?nm silicon oxide is studied. A simple model for measuring adhesion force for a flat surface with sub-nanometer roughness was developed and is shown that small surface roughness decreases adhesion force while large roughness results in an effectively larger adhesion forces. We also show that surface roughness over scales comparable to the tip radius increase by nearly a factor of two, the effective adhesion force measured by the atomic force microscopy. Thus, we demonstrate that surface roughness is an important parameter that should be taken into account in analyzing the adhesion force measurement results.

  16. Improved Constraints on an Axion-Mediated Force

    SciTech Connect (OSTI)

    Hoedl, S. A.; Fleischer, F.; Adelberger, E. G.; Heckel, B. R. [Center for Experimental Nuclear Physics and Astrophysics, Box 354290, University of Washington, Seattle, Washington 98195-4290 (United States)

    2011-01-28T23:59:59.000Z

    Low mass pseudoscalars, such as the axion, can mediate macroscopic parity and time-reversal symmetry-violating forces. We searched for such a force between polarized electrons and unpolarized atoms using a novel, magnetically unshielded torsion pendulum. We improved the laboratory bounds on this force by more than 10 orders of magnitude for pseudoscalars heavier than 1 meV and have constrained this force over a broad range of astrophysically interesting masses (10 {mu}eV to 10 meV).

  17. Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment

    SciTech Connect (OSTI)

    Mitran, Sorin, E-mail: mitran@unc.edu

    2013-07-01T23:59:59.000Z

    The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale.

  18. Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers

    SciTech Connect (OSTI)

    Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U. [Arizona State University, Tempe, AZ 85287-1504 (United States); Centre for Free-Electron Laser Science, DESY, D-22607 Hamburg (Germany); Arizona State University, Tempe, AZ 85287-1504 (United States)

    2012-11-27T23:59:59.000Z

    Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

  19. Friction forces on phase transition fronts

    E-Print Network [OSTI]

    Ariel Megevand

    2013-03-31T23:59:59.000Z

    In cosmological first-order phase transitions, the microscopic interaction of the phase transition fronts with non-equilibrium plasma particles manifests itself macroscopically as friction forces. In general, it is a nontrivial problem to compute these forces, and only two limits have been studied, namely, that of very slow walls and, more recently, ultra-relativistic walls which run away. In this paper we consider ultra-relativistic velocities and show that stationary solutions still exist when the parameters allow the existence of runaway walls. Hence, we discuss the necessary and sufficient conditions for the fronts to actually run away. We also propose a phenomenological model for the friction, which interpolates between the non-relativistic and ultra-relativistic values. Thus, the friction depends on two friction coefficients which can be calculated for specific models. We then study the velocity of phase transition fronts as a function of the friction parameters, the thermodynamic parameters, and the amount of supercooling.

  20. Ultra high frequency imaging acoustic microscope

    DOE Patents [OSTI]

    Deason, Vance A.; Telschow, Kenneth L.

    2006-05-23T23:59:59.000Z

    An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

  1. Scanning tunneling microscope assembly, reactor, and system

    DOE Patents [OSTI]

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18T23:59:59.000Z

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  2. A microscopic mechanism for increasing thermoelectric efficiency

    E-Print Network [OSTI]

    Keiji Saito; Giuliano Benenti; Giulio Casati

    2010-05-26T23:59:59.000Z

    We study the coupled particle and energy transport in a prototype model of interacting one-dimensional system: the disordered hard-point gas, for which numerical data suggest that the thermoelectric figure of merit ZT diverges with the system size. This result is explained in terms of a microscopic mechanism, namely the local equilibrium is characterized by the emergence of a broad stationary "modified Maxwell-Boltzmann velocity distribution", of width much larger than the mean velocity of the particle flow.

  3. Defocus step size of the LBNL One Angstrom Microscope

    E-Print Network [OSTI]

    O'Keefe, Michael A.; Nelson, E. Chris

    2002-01-01T23:59:59.000Z

    64 (1996) 211-230. p2/6 LBNL/PUB-3170 One Angstromcurrent. Measurements on the LBNL One- Angstrom MicroscopeLBNL/PUB-3170 One-Ångstrom Microscope Report: One Angstrom

  4. Design and Construction of a Low Temperature Scanning Tunneling Microscope

    E-Print Network [OSTI]

    Chen, Chi

    2010-10-12T23:59:59.000Z

    A low temperature scanning tunneling microscope (LTSTM) was built that we could use in an ultra high vacuum (UHV) system. The scanning tunneling microscope (STM) was tested on an existing 3He cryostat and calibrated at room, liquid nitrogen...

  5. 3D Printed Microscope for Mobile Devices that Cost Pennies

    SciTech Connect (OSTI)

    Erikson, Rebecca; Baird, Cheryl; Hutchinson, Janine

    2014-09-15T23:59:59.000Z

    Scientists at PNNL have designed a 3D-printable microscope for mobile devices using pennies worth of plastic and glass materials. The microscope has a wide range of uses, from education to in-the-field science.

  6. atom-atom collisions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Safronova, Marianna 3 Atom-atom correlations in colliding Bose-Einstein condensates Quantum Physics (arXiv) Summary: We analyze atom-atom correlations in the s-wave...

  7. Fermionic Luttinger liquids from a microscopic perspective

    E-Print Network [OSTI]

    Manuel Valiente; Lawrence G. Phillips; Nikolaj T. Zinner; Patrik Ohberg

    2015-05-13T23:59:59.000Z

    We consider interacting one-dimensional, spinless Fermi gases, whose low-energy properties are described by Luttinger liquid theory. We perform a systematic, in-depth analysis of the relation between the macroscopic, phenomenological parameters of Luttinger liquid effective field theory, and the microscopic interactions of the Fermi gas. In particular, we begin by explaining how to model effective interactions in one dimension, which we then apply to the main forward scattering channel -- the interbranch collisions -- common to these systems. We renormalise the corresponding interbranch phenomenological constants in favour of scattering phase shifts. Interestingly, our renormalisation procedure shows (i) how Luttinger's model arises in a completely natural way -- and not as a convenient approximation -- from Tomonaga's model, and (ii) the reasons behind the interbranch coupling constant remaining unrenormalised in Luttinger's model. We then consider the so-called intrabranch processes, whose phenomenological coupling constant is known to be fixed by charge conservation, but whose microscopic origin is not well understood. We show that, contrary to general belief and common sense, the intrabranch interactions appearing in Luttinger liquid theory do not correspond to an intrabranch scattering channel, nor an energy shift due to intrabranch interactions, in the microscopic theory. Instead, they are due to interbranch processes. We finally apply our results to a particular example of an exactly solvable model, namely the fermionic dual to the Lieb-Liniger model in the Tonks-Girardeau and super-Tonks-Girardeau regimes.

  8. Nano Positioning of Single Atoms in a Micro Cavity

    E-Print Network [OSTI]

    Stefan Nussmann; Markus Hijlkema; Bernhard Weber; Felix Rohde; Gerhard Rempe; Axel Kuhn

    2005-06-10T23:59:59.000Z

    The coupling of individual atoms to a high-finesse optical cavity is precisely controlled and adjusted using a standing-wave dipole-force trap, a challenge for strong atom-cavity coupling. Ultracold Rubidium atoms are first loaded into potential minima of the dipole trap in the center of the cavity. Then we use the trap as a conveyor belt that we set into motion perpendicular to the cavity axis. This allows us to repetitively move atoms out of and back into the cavity mode with a repositioning precision of 135 nm. This makes possible to either selectively address one atom of a string of atoms by the cavity, or to simultaneously couple two precisely separated atoms to a higher mode of the cavity.

  9. Characterization of Dynamic Surface Processes by Atomic Force Microscopy

    E-Print Network [OSTI]

    Shao, Jingru

    2014-01-01T23:59:59.000Z

    hydrogen terminated as synthesized but may slowly become oxidized to oxygen termi- nated under long time storage

  10. The study of organic crystals by atomic force microscopy

    E-Print Network [OSTI]

    Chow, Ernest Ho Hin

    2014-07-01T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3.10 AFM amplitude profile of ASA (001) under ambient conditions before and after contact with dicalcium phosphate. . . . . . . . 47 4.1 Picture of the Multimode AFM instrument with labelled parts. . 49 4.2 3-D height profile of a standard... List of Abbreviations AN Anthracene ANQ Anthraquinone API Active pharmaceutical ingredient ASA Aspirin ATR Attenuated total reflection BFDH Bravais-Friedel-Donnay-Harker model CSD Cambridge Structural Database DSC Differential scanning calorimetry DPI...

  11. Ultrasonic-Based Mode-Synthesizing Atomic Force Microscopy - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin TransitionProgram |FrankUltrafastHydrogen and FuelInnovation

  12. Workshop on Atomic Force Microscopy, Nanometrology and More | GE Global

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat isJoin the ChallengeHistory

  13. Microscopic nature of the photon strength function: stable and unstable Ni and Sn isotopes

    E-Print Network [OSTI]

    Achakovskiy, Oleg; Goriely, Stephane; Kamerdzhiev, Sergei; Krewald, Siegfried; Voitenkov, Dmitriy

    2014-01-01T23:59:59.000Z

    The pygmy-dipole resonances and photon strength functions in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite fermi systems which includes the QRPA and phonon coupling effects and uses the known Skyrme forces SLy4. The pygmy dipole resonance in $^{72}Ni$ is predicted with the mean energy of 12.4 MeV and the energy-weighted sum rule exhausting 25.6\\% of the total strength. The microscopically obtained photon E1 strength functions are used to calculate nuclear reaction properties, i.e the radiative neutron capture cross section, gamma-ray spectra, and average radiative widths. Our main conclusion is that in all these quantities it is necessary to take the phonon coupling effects into account.

  14. Momentum diffusion for coupled atom-cavity oscillators * P. Maunz,1

    E-Print Network [OSTI]

    Rempe, Gerhard

    the diffusion originating from the fluctuations of the forces due to the coupling to the vacuum modes other than to fluctuations, in par- ticular, light-force fluctuations, which heat the atom. Indeed, several experiments for the heating rate, which also gives insight into the physics of force fluc- tuations in a cavity

  15. Braking system for use with an arbor of a microscope

    DOE Patents [OSTI]

    Norgren, Duane U. (Orinda, CA)

    1984-01-01T23:59:59.000Z

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  16. Machine Learning for Quantum Mechanical Properties of Atoms in Molecules

    E-Print Network [OSTI]

    Rupp, Matthias; von Lilienfeld, O Anatole

    2015-01-01T23:59:59.000Z

    We introduce machine learning models of quantum mechanical observables of atoms in molecules. Instant out-of-sample predictions for proton and carbon nuclear chemical shifts, atomic core level excitations, and forces on atoms reach accuracies on par with density functional theory reference. Locality is exploited within non-linear regression via local atom-centered coordinate systems. The approach is validated on a diverse set of 9k small organic molecules. Linear scaling is demonstrated for saturated polymers with up to sub-mesoscale lengths.

  17. Dilution and resonance-enhanced repulsion in nonequilibrium fluctuation forces

    SciTech Connect (OSTI)

    Bimonte, Giuseppe [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, Complesso Universitario MSA, Via Cintia, I-80126 Napoli (Italy); INFN Sezione di Napoli, I-80126 Napoli (Italy); Emig, Thorsten [Laboratoire de Physique Theorique et Modeles Statistiques, CNRS UMR 8626, Bat. 100, Universite Paris-Sud, F-91405 Orsay cedex (France); Krueger, Matthias; Kardar, Mehran [Massachusetts Institute of Technology, Department of Physics, Cambridge, Massachusetts 02139 (United States)

    2011-10-15T23:59:59.000Z

    In equilibrium, forces induced by fluctuations of the electromagnetic field between electrically polarizable objects (microscopic or macroscopic) in vacuum are generically attractive. The force may, however, become repulsive for microscopic particles coupled to thermal baths with different temperatures. We demonstrate that this nonequilibrium repulsion can be realized also between macroscopic objects, as planar slabs, if they are kept at different temperatures. It is shown that repulsion can be enhanced by (i) tuning of material resonances in the thermal region and by (ii) reducing the dielectric contrast due to ''dilution''. This can lead to stable equilibrium positions. We discuss the realization of these effects for aerogels, yielding repulsion down to submicron distances at realistic porosities.

  18. Calibration of the torsional spring constant and the lateral photodiode response of frictional force microscopes

    E-Print Network [OSTI]

    Attard, Phil

    Calibration of the torsional spring constant and the lateral photodiode response of frictional simultaneously calibrates the photodiode response to the angular deflection of the cantilever. It does not rely and with an independent measurement of the angle calibration. This nondestructive calibration may be performed with any

  19. Microscopic Calculation of 240Pu Scission with a Finite-Range Effective Force

    SciTech Connect (OSTI)

    Younes, W; Gogny, D

    2009-05-04T23:59:59.000Z

    Hartree-Fock-Bogoliubov calculations of hot fission in {sup 240}Pu have been performed with a newly-implemented code that uses the D1S finite-range effective interaction. The hot-scission line is identified in the quadrupole-octupole-moment coordinate space. Fission-fragment shapes are extracted from the calculations. A benchmark calculation for {sup 226}Th is obtained and compared to results in the literature. In addition, technical aspects of the use of HFB calculations for fission studies are examined in detail. In particular, the identification of scission configurations, the sensitivity of near-scission calculations to the choice of collective coordinates in the HFB iterations, and the formalism for the adjustment of collective-variable constraints are discussed. The power of the constraint-adjustment algorithm is illustrated with calculations near the critical scission configurations with up to seven simultaneous constraints.

  20. The Magnetic Resonance Force Microscope P. Chris Hammel and Denis V. Pelekhov

    E-Print Network [OSTI]

    Hammel, P. Chris

    , Zhang, Moore and Roukes, 1995; Bruland et al., 1998) and ferromagnetic resonance (FMR) experiments

  1. Probing Dark Energy with Atom Interferometry

    E-Print Network [OSTI]

    Clare Burrage; Edmund J. Copeland; E. A. Hinds

    2014-08-06T23:59:59.000Z

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  2. Ponderomotive phase plate for transmission electron microscopes

    DOE Patents [OSTI]

    Reed, Bryan W. (Livermore, CA)

    2012-07-10T23:59:59.000Z

    A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

  3. Acoustic microscope surface inspection system and method

    DOE Patents [OSTI]

    Khuri-Yakub, B.T.; Parent, P.; Reinholdtsen, P.A.

    1991-02-26T23:59:59.000Z

    An acoustic microscope surface inspection system and method are described in which pulses of high frequency electrical energy are applied to a transducer which forms and focuses acoustic energy onto a selected location on the surface of an object and receives energy from the location and generates electrical pulses. The phase of the high frequency electrical signal pulses are stepped with respect to the phase of a reference signal at said location. An output signal is generated which is indicative of the surface of said selected location. The object is scanned to provide output signals representative of the surface at a plurality of surface locations. 7 figures.

  4. Casimir force: an alternative treatment

    E-Print Network [OSTI]

    P. R. Silva

    2009-01-07T23:59:59.000Z

    The Casimir force between two parallel uncharged closely spaced metallic plates is evaluated in ways alternatives to those usually considered in the literature. In a first approximation we take in account the suppressed quantum numbers of a cubic box, representing a cavity which was cut in a metallic block. We combine these ideas with those of the MIT bag model of hadrons, but adapted to non-relativistic particles. In a second approximation we consider the particles occupying the energy levels of the Bohr atom, so that the Casimir force depends explicitly on the fine structure constant alpha. In both treatments, the mean energies which have explicit dependence on the particle mass and on the maximum occupied quantum number (related to the Fermi level of the system) at the beginning of the calculations, have these dependences mutually canceled at the end of them. Finally by comparing the averaged energies computed in both approximations, we are able to make an estimate of the value of the fine structure constant alpha.

  5. NUCLEAR PROXIMITY FORCES

    E-Print Network [OSTI]

    Randrup, J.

    2011-01-01T23:59:59.000Z

    One might summarize of nuclear potential energy has beendegree of freedom) for the nuclear interaction between anyUniversity of California. Nuclear Proximity Forces 'I< at

  6. Forces from Connes' geometry

    E-Print Network [OSTI]

    Thomas Schucker

    2007-03-26T23:59:59.000Z

    We try to give a pedagogical introduction to Connes' derivation of the standard model of electro-magnetic, weak and strong forces from gravity.

  7. Linear relationship between water wetting behavior and microscopic interactions of super-hydrophilic surfaces

    SciTech Connect (OSTI)

    Liu, Jian; Guo, Pan [Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China) [Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Chunlei; Shi, Guosheng, E-mail: shiguosheng@sinap.ac.cn; Fang, Haiping [Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China)] [Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China)

    2013-12-21T23:59:59.000Z

    Using molecular dynamics simulations, we show a fine linear relationship between surface energies and microscopic Lennard-Jones parameters of super-hydrophilic surfaces. The linear slope of the super-hydrophilic surfaces is consistent with the linear slope of the super-hydrophobic, hydrophobic, and hydrophilic surfaces where stable water droplets can stand, indicating that there is a universal linear behavior of the surface energies with the water-surface van der Waals interaction that extends from the super-hydrophobic to super-hydrophilic surfaces. Moreover, we find that the linear relationship exists for various substrate types, and the linear slopes of these different types of substrates are dependent on the surface atom density, i.e., higher surface atom densities correspond to larger linear slopes. These results enrich our understanding of water behavior on solid surfaces, especially the water wetting behaviors on uncharged super-hydrophilic metal surfaces.

  8. Atomizing nozzle and process

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20T23:59:59.000Z

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  9. Protective Force Program Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-12-20T23:59:59.000Z

    Provides detailed requirements to supplement DOE O 473.2, PROTECTIVE FORCE PROGRAM, which establishes the requirements and responsibilities for management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Change 1 revised pages in Chapters IV and VI on 12/20/2001.

  10. Interfacing light and single atoms with a lens

    E-Print Network [OSTI]

    Meng Khoon Tey; Gleb Maslennikov; Timothy C. H. Liew; Syed Abdullah Aljunid; Florian Huber; Brenda Chng; Zilong Chen; Valerio Scarani; Christian Kurtsiefer

    2009-02-17T23:59:59.000Z

    We characterize the interaction between a single atom or similar microscopic system and a light field via the scattering ratio. For that, we first derive the electrical field in a strongly focused Gaussian light beam, and then consider the atomic response. Following the simple scattering model, the fraction of scattered optical power for a weak coherent probe field leads to unphysical scattering ratios above 1 in the strong focusing regime. A refined model considering interference between exciting and scattered field into finite-sized detectors or optical fibers is presented, and compared to experimental extinction measurements for various focusing strengths.

  11. Atomic swelling upon compression

    E-Print Network [OSTI]

    V. K. Dolmatov; J. L. King

    2012-08-18T23:59:59.000Z

    The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.

  12. Microscopic Description of Nuclear Fission Dynamics

    E-Print Network [OSTI]

    A. S. Umar; V. E. Oberacker; J. A. Maruhn; P. -G. Reinhard

    2010-03-22T23:59:59.000Z

    We discuss possible avenues to study fission dynamics starting from a time-dependent mean-field approach. Previous attempts to study fission dynamics using the time-dependent Hartree-Fock (TDHF) theory are analyzed. We argue that different initial conditions may be needed to describe fission dynamics depending on the specifics of the fission phenomenon and propose various approaches towards this goal. In particular, we provide preliminary calculations for studying fission following a heavy-ion reaction using TDHF with a density contraint. Regarding prompt muon-induced fission, we also suggest a new approach for combining the time-evolution of the muonic wave function with a microscopic treatment of fission dynamics via TDHF.

  13. Long working distance incoherent interference microscope

    DOE Patents [OSTI]

    Sinclair, Michael B. (Albuquerque, NM); De Boer, Maarten P. (Albuquerque, NM)

    2006-04-25T23:59:59.000Z

    A full-field imaging, long working distance, incoherent interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. A long working distance greater than 10 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-dimensional height profiles of MEMS test structures to be acquired across an entire wafer while being actively probed, and, optionally, through a transparent window. An optically identical pair of sample and reference arm objectives is not required, which reduces the overall system cost, and also the cost and time required to change sample magnifications. Using a LED source, high magnification (e.g., 50.times.) can be obtained having excellent image quality, straight fringes, and high fringe contrast.

  14. Three-dimensional scanning confocal laser microscope

    DOE Patents [OSTI]

    Anderson, R. Rox (Lexington, MA); Webb, Robert H. (Lincoln, MA); Rajadhyaksha, Milind (Charlestown, MA)

    1999-01-01T23:59:59.000Z

    A confocal microscope for generating an image of a sample includes a first scanning element for scanning a light beam along a first axis, and a second scanning element for scanning the light beam at a predetermined amplitude along a second axis perpendicular to the first axis. A third scanning element scans the light beam at a predetermined amplitude along a third axis perpendicular to an imaging plane defined by the first and second axes. The second and third scanning element are synchronized to scan at the same frequency. The second and third predetermined amplitudes are percentages of their maximum amplitudes. A selector determines the second and third predetermined amplitudes such that the sum of the percentages is equal to one-hundred percent.

  15. A microscopic perspective on stochastic thermodynamics

    E-Print Network [OSTI]

    Bernhard Altaner; Jürgen Vollmer

    2015-05-18T23:59:59.000Z

    We consider stochastic thermodynamics as a theory of statistical inference for experimentally observed fluctuating time-series. To that end, we introduce a general framework for quantifying the knowledge about the dynamical state of the system on two scales: a fine-grained or microscopic, deterministic and a coarse-grained or mesoscopic, stochastic level of description. For a generic model dynamics, we show how the mathematical expressions for fluctuating entropy changes used in Markovian stochastic thermodynamics emerge naturally. Our ideas are conceptional approaches towards (i) connecting entropy production and its fluctuation relations in deterministic and stochastic systems and (ii) providing a complementary information-theoretic picture to notions of entropy and entropy production in stochastic thermodynamics.

  16. Microscopic study of Ca$+$Ca fusion

    E-Print Network [OSTI]

    R. Keser; A. S. Umar; V. E. Oberacker

    2012-02-17T23:59:59.000Z

    We investigate the fusion barriers for reactions involving Ca isotopes $\\mathrm{^{40}Ca}+\\mathrm{^{40}Ca}$, $\\mathrm{^{40}Ca}+\\mathrm{^{48}Ca}$, and $\\mathrm{^{48}Ca}+\\mathrm{^{48}Ca}$ using the microscopic time-dependent Hartree-Fock theory coupled with a density constraint. In this formalism the fusion barriers are directly obtained from TDHF dynamics. We also study the excitation of the pre-equilibrium GDR for the $\\mathrm{^{40}Ca}+\\mathrm{^{48}Ca}$ system and the associated $\\gamma$-ray emission spectrum. Fusion cross-sections are calculated using the incoming-wave boundary condition approach. We examine the dependence of fusion barriers on collision energy as well as on the different parametrizations of the Skyrme interaction.

  17. Particles and Forces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    amount of positive charge. How does an atom look on the inside? 1) Shooting at a bag of beans 2) Bag of equal weight but stuffed with cotton and a few small lead beads Compare the...

  18. OOTW Force Design Tools

    SciTech Connect (OSTI)

    Bell, R.E.; Hartley, D.S.III; Packard, S.L.

    1999-05-01T23:59:59.000Z

    This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

  19. Microscopic Reactive Diffusion of Uranium in the Contaminated...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United States. Microscopic Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United...

  20. au microscope electronique: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Microscope Geosciences Websites Summary: applications ranging from thermoelectric waste heat recovery to radio astronomy. BIOGRAPHY Austin MinnichDepartment of Mechanical...

  1. Weak nuclear forces cause the strong nuclear force

    E-Print Network [OSTI]

    E. L. Koschmieder

    2007-12-11T23:59:59.000Z

    We determine the strength of the weak nuclear force which holds the lattices of the elementary particles together. We also determine the strength of the strong nuclear force which emanates from the sides of the nuclear lattices. The strong force is the sum of the unsaturated weak forces at the surface of the nuclear lattices. The strong force is then about ten to the power of 6 times stronger than the weak force between two lattice points.

  2. Long Range Interactions With Laser Cooled Neutral Atoms

    SciTech Connect (OSTI)

    Gattobigio, Giovanni Luca [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne France (France); Dipartimento di Fisica dell'Universita di Ferrara, 44100 Ferrara (Italy); Michaud, Franck; Labeyrie, Guillaume; Kaiser, Robin [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne (France); Loureiro, Jorge; Mendonca, Jose Tito; Tercas, Hugo [Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Pohl, Thomas [ITAMP, 60 Garden Street, Cambridge, MA 02138 (United States)

    2008-09-07T23:59:59.000Z

    Multiple scattering of light in a trap of laser cooled neutral atoms leads to repulsion forces between the atoms. The corresponding interactions have long range behavior in 1/r{sup 2} and are thus similar to Coulomb interaction in an one component confined plasma. Consequences of these interactions will be described in this paper, including the limitation of the spatial density one can obtain in such systems and self-sustained oscillations of the cloud.

  3. Scattering approach to dispersive atom-surface interactions

    SciTech Connect (OSTI)

    Dalvit, Diego [Los Alamos National Laboratory; Messina, Riccardo [LAB KASTLER BROSSEL; Maia Neto, Paulo [INSTITUTO DE FISICA UFRJ; Lambrecht, Astrid [LAB KASTLER BROSSEL; Reynaud, Serge [LAB KASTLER BROSSEL

    2009-01-01T23:59:59.000Z

    We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We consider in detail the correction to the proximity force approximation, and present a very simple approximation algorithm for computing the potential.

  4. Federal Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2009-07-15T23:59:59.000Z

    This Manual establishes requirements for the management and operation of the Department of Energy (DOE) Federal protective forces (FPFs). Cancels DOE M 470.4-3, Chg 1. Canceled by DOE O 473.3.

  5. Protective Force Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-02-13T23:59:59.000Z

    To prescribe Department of Energy policy, responsibilities, and requirements for the management and operation of the Protective Force Program. Chg 1 dated 2-13-95. Cancels DOE O 5632.7 and DOE O 5632.8.

  6. Strategic forces briefing

    SciTech Connect (OSTI)

    Bing, G.; Chrzanowski, P.; May, M.; Nordyke, M.

    1989-04-06T23:59:59.000Z

    The Strategic Forces Briefing'' is our attempt, accomplished over the past several months, to outline and highlight the more significant strategic force issues that must be addressed in the near future. Some issues are recurrent: the need for an effective modernized Triad and a constant concern for force survivability. Some issues derive from arms control: the Strategic Arms Reduction Talks (SALT) are sufficiently advanced to set broad numerical limits on forces, but not so constraining as to preclude choices among weapon systems and deployment modes. Finally, a new administration faced with serious budgetary problems must strive for the most effective strategic forces limited dollars can buy and support. A review of strategic forces logically begins with consideration of the missions the forces are charged with. We begin the briefing with a short review of targeting policy and implementation within the constraints of available unclassified information. We then review each element of the Triad with sections on SLBMs, ICBMs, and Air-Breathing (bomber and cruise missile) systems. A short section at the end deals with the potential impact of strategic defense on offensive force planning. We consider ABM, ASAT, and air defense; but we do not attempt to address the technical issues of strategic defense per se. The final section gives a brief overview of the tritium supply problem. We conclude with a summary of recommendations that emerge from our review. The results of calculation on the effectiveness of various weapon systems as a function of cost that are presented in the briefing are by Paul Chrzanowski.

  7. Propagation of nonlinearly generated harmonic spin waves in microscopic stripes

    E-Print Network [OSTI]

    Otani, Yoshichika

    Propagation of nonlinearly generated harmonic spin waves in microscopic stripes O. Rousseau,1 M on the experimental study of the propagation of nonlinearly generated harmonic spin waves in microscopic CoFeB stripes wave propagation. VC 2014 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4864480] In recent years

  8. How to benchmark a wide field fluorescent microscope

    E-Print Network [OSTI]

    available for your microscope camera. -http://www.micro-manager.org/wiki/Device%20Support (tested with Roper;Limitations · This is a beta-test ­ Only tested with ~10 different widefield microscope systems with CCD in polystyrene sample holders was cut with a Dremel tool. Rough edges were removed by scraping with a razor blade

  9. Improved graphite furnace atomizer

    DOE Patents [OSTI]

    Siemer, D.D.

    1983-05-18T23:59:59.000Z

    A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

  10. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

  11. Signatures of hydrophobic collapse in extended proteins captured with force spectroscopy

    E-Print Network [OSTI]

    Fernandez, Julio M.

    of the different driving forces in protein folding. atomic force microscopy molecular dynamics protein folding chemicals. Protein folding probed under these conditions has revealed two-state folding for many small to each other. It is widely accepted that, under such conditions, protein folding is driven mostly

  12. Researcher Supported by Atomic Energy Commission and U.S. Department...

    Broader source: Energy.gov (indexed) [DOE]

    smallest building blocks of all matter and three of nature's four forces in one single theory." Over a period of three decades starting in the 1960s, the Atomic Energy Commission,...

  13. VOLUME 82, NUMBER 26 P HY S I CA L R E V I E W L E T T E R S 28 JUNE 1999 LaserDriven Atomic Pump

    E-Print Network [OSTI]

    , and by the wind force Fw caused by the reflection of conduction electrons from these atoms. Since F d usually, as schematically depicted in Fig. 1, by exerting on it the wind force Fw , due to the absorption of electron are driven by the direct force F d due to the external field that is locally modified at the atomic site

  14. VOLUME 82, NUMBER 26 P H Y S I C A L R E V I E W L E T T E R S 28 JUNE 1999 Laser-Driven Atomic Pump

    E-Print Network [OSTI]

    by the direct force Fd due to the external field that is locally modified at the atomic site, and by the wind in Fig. 1, by exerting on it the wind force Fw, due to the absorption of electron momenta. The direct force Fw caused by the reflection of conduction electrons from these atoms. Since Fd usually dominates

  15. Method and apparatus for differential spectroscopic atomic-imaging using scanning tunneling microscopy

    DOE Patents [OSTI]

    Kazmerski, Lawrence L. (Lakewood, CO)

    1990-01-01T23:59:59.000Z

    A Method and apparatus for differential spectroscopic atomic-imaging is disclosed for spatial resolution and imaging for display not only individual atoms on a sample surface, but also bonding and the specific atomic species in such bond. The apparatus includes a scanning tunneling microscope (STM) that is modified to include photon biasing, preferably a tuneable laser, modulating electronic surface biasing for the sample, and temperature biasing, preferably a vibration-free refrigerated sample mounting stage. Computer control and data processing and visual display components are also included. The method includes modulating the electronic bias voltage with and without selected photon wavelengths and frequency biasing under a stabilizing (usually cold) bias temperature to detect bonding and specific atomic species in the bonds as the STM rasters the sample. This data is processed along with atomic spatial topography data obtained from the STM raster scan to create a real-time visual image of the atoms on the sample surface.

  16. Insertion of Zn atoms into Cu3N lattice: Structural distortion and modification of electronic properties

    E-Print Network [OSTI]

    Zexian, Cao

    Cu and nitrogen. Consequently it can be used in the fabrication of microscopic copper lines are positioned at the middle of the edges and the nitrogen atoms are situated at the corners of a cube inserted to the cell centers in bulk Cu3N; on the other hand, the effect of copper [12], titanium [13

  17. Producing and Detecting Correlated atoms

    E-Print Network [OSTI]

    Christoph I. Westbrook; Martijn Schellekens; Aurélien Perrin; Valentina Krachmalnicoff; Jose Carlos Viana Gomes; Jean-Baptiste Trebbia; Jérôme Estève; Hong Chang; Isabelle Bouchoule; Denis Boiron; Alain Aspect; Tom Jeltes; John McNamara; Wim Hogervorst; Wim Vassen

    2006-09-04T23:59:59.000Z

    We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions.We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wavemixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.

  18. Unbalanced electromagnetic forces

    E-Print Network [OSTI]

    Hansen, Craig Martin

    1974-01-01T23:59:59.000Z

    coils V ? 4 Vertical spring suspension experiment V ? 5 Horizontal suspension experiment 74 V ? 6 Linear plot of data for egg-shaped coil; horizontal suspension experiment V ? 7 Log-log plot of data for egg-shaped coil; horizontal suspension... segment L on straight line current segment L 53 V-1 Geometrical configuration of experimental coils. . . 62 V ? 2 Retational system for measuring force in various size points 65 xi ~Fi ure V ? 3 Rotational system for measuring force in egg-shaped...

  19. Surface forces: Surface roughness in theory and experiment

    SciTech Connect (OSTI)

    Parsons, Drew F., E-mail: Drew.Parsons@anu.edu.au; Walsh, Rick B.; Craig, Vincent S. J. [Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)] [Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2014-04-28T23:59:59.000Z

    A method of incorporating surface roughness into theoretical calculations of surface forces is presented. The model contains two chief elements. First, surface roughness is represented as a probability distribution of surface heights around an average surface height. A roughness-averaged force is determined by taking an average of the classic flat-surface force, weighing all possible separation distances against the probability distributions of surface heights. Second the model adds a repulsive contact force due to the elastic contact of asperities. We derive a simple analytic expression for the contact force. The general impact of roughness is to amplify the long range behaviour of noncontact (DLVO) forces. The impact of the elastic contact force is to provide a repulsive wall which is felt at a separation between surfaces that scales with the root-mean-square (RMS) roughness of the surfaces. The model therefore provides a means of distinguishing between “true zero,” where the separation between the average centres of each surface is zero, and “apparent zero,” defined by the onset of the repulsive contact wall. A normal distribution may be assumed for the surface probability distribution, characterised by the RMS roughness measured by atomic force microscopy (AFM). Alternatively the probability distribution may be defined by the histogram of heights measured by AFM. Both methods of treating surface roughness are compared against the classic smooth surface calculation and experimental AFM measurement.

  20. Classical Helium Atom with Radiation Reaction

    E-Print Network [OSTI]

    G. Camelio; A. Carati; L. Galgani

    2011-11-24T23:59:59.000Z

    We study a classical model of Helium atom in which, in addition to the Coulomb forces, the radiation reaction forces are taken into account. This modification brings in the model a new qualitative feature of a global character. Indeed, as pointed out by Dirac, in any model of classical electrodynamics of point particles involving radiation reaction one has to eliminate, from the a priori conceivable solutions of the problem, those corresponding to the emission of an infinite amount of energy. We show that the Dirac prescription solves a problem of inconsistency plaguing all available models which neglect radiation reaction, namely, the fact that in all such models most initial data lead to a spontaneous breakdown of the atom. A further modification is that the system thus acquires a peculiar form of dissipation. In particular, this makes attractive an invariant manifold of special physical interest, the zero--dipole manifold, that corresponds to motions in which no energy is radiated away (in the dipole approximation). We finally study numerically the invariant measure naturally induced by the time--evolution on such a manifold, and this corresponds to studying the formation process of the atom. Indications are given that such a measure may be singular with respect to that of Lebesgue.

  1. Casimir Friction Force for Moving Harmonic Oscillators

    E-Print Network [OSTI]

    Johan S. Høye; Iver Brevik

    2011-11-21T23:59:59.000Z

    Casimir friction is analyzed for a pair of dielectric particles in relative motion. We first adopt a microscopic model for harmonically oscillating particles at finite temperature T moving non-relativistically with constant velocity. We use a statistical-mechanical description where time-dependent correlations are involved. This description is physical and direct, and, in spite of its simplicity, is able to elucidate the essentials of the problem. This treatment elaborates upon, and extends, an earlier theory of ours back in 1992. The energy change Delta E turns out to be finite in general, corresponding to a finite friction force. In the limit of zero temperature the formalism yields, however, Delta E ->0, this being due to our assumption about constant velocity, meaning slowly varying coupling. For couplings varying more rapidly, there will also be a finite friction force at T=0. As second part of our work, we consider the friction problem using time-dependent perturbation theory. The dissipation, basically a second order effect, is obtainable with the use of first order theory, the reason being the absence of cross terms due to uncorrelated phases of eigenstates. The third part of the present paper is to demonstrate explicitly the equivalence of our results with those recently obtained by Barton (2010); this being not a trivial task since the formal results are seemingly quite different from each other.

  2. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  3. Protective Force Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2000-06-30T23:59:59.000Z

    Establishes policy, requirements, responsibilities, and authorities, for the management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Extended until 7-7-06 by DOE N 251.64, dated 7-7-05 Cancels: DOE 5632.7A

  4. Contractor Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-11-05T23:59:59.000Z

    This Manual establishes requirements for the management and operation of the U.S. Department of Energy contractor protective forces. Cancels: DOE M 470.4-3 Chg 1, CRD (Attachment 2) only, except for Section C. Canceled by DOE O 473.3.

  5. Work Force Discipline

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1983-03-23T23:59:59.000Z

    The order provides guidance and procedures and states responsibilities for maintaining work force discipline in DOE. Chg 1, dated 3-11-85; Chg 2, dated 1-6-86; Chg 3, dated 3-21-89; Chg 4, dated 8-2-90; Chg 5, dated 3-9-92; Chg 6, dated 8-21-92, cancels Chg 5.

  6. Low temperature MFM imaging of Fe??xV??xAl intermetallics

    E-Print Network [OSTI]

    Nooner, Scott Lee

    1999-01-01T23:59:59.000Z

    A low temperature magnetic force microscope (MFM) system was set up by adapting a commercial atomic force microscope (AFM) from Park Scientific Instruments (PSI) for low temperature MFM use. Magnetic cantilevers were fabricated for the low...

  7. Bending buckling of single-walled carbon nanotubes by atomic-scale finite element

    E-Print Network [OSTI]

    Jiang, Hanqing

    - vered SWNT loaded by a follower lateral force at the free end and found that it exhibited local bucklingBending buckling of single-walled carbon nanotubes by atomic-scale finite element X. Guo a , A Abstract This paper employs the atomic-scale finite element method to study bending buckling of single

  8. Atom chip apparatus for experiments with ultracold rubidium and potassium gases

    SciTech Connect (OSTI)

    Ivory, M. K.; Ziltz, A. R.; Fancher, C. T.; Pyle, A. J.; Sensharma, A.; Chase, B.; Field, J. P.; Garcia, A.; Aubin, S., E-mail: saaubi@wm.edu [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187 (United States); Jervis, D. [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)] [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

    2014-04-15T23:59:59.000Z

    We present a dual chamber atom chip apparatus for generating ultracold {sup 87}Rb and {sup 39}K atomic gases. The apparatus produces quasi-pure Bose-Einstein condensates of 10{sup 4} {sup 87}Rb atoms in an atom chip trap that features a dimple and good optical access. We have also demonstrated production of ultracold {sup 39}K and subsequent loading into the chip trap. We describe the details of the dual chamber vacuum system, the cooling lasers, the magnetic trap, the multicoil magnetic transport system, the atom chip, and two optical dipole traps. Due in part to the use of light-induced atom desorption, the laser cooling chamber features a sufficiently good vacuum to also support optical dipole trap-based experiments. The apparatus is well suited for studies of atom-surface forces, quantum pumping and transport experiments, atom interferometry, novel chip-based traps, and studies of one-dimensional many-body systems.

  9. Atomic and molecular supernovae

    SciTech Connect (OSTI)

    Liu, W.

    1997-12-01T23:59:59.000Z

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  10. Impact of graphene coating on the atom-plate interaction

    E-Print Network [OSTI]

    G. L. Klimchitskaya; V. M. Mostepanenko

    2014-06-23T23:59:59.000Z

    Using the recently proposed quantum electrodynamical formalism, we calculate the Casimir-Polder free energies and forces between the ground state atoms of Rb, Na, Cs and He${}^{\\ast}$ and the plates made of Au, Si, sapphire and fused silica coated with a graphene sheet. It is shown that the graphene coating has no effect on the Casimir-Polder interaction for metallic plates, but influences significantly for plates made of dielectric materials. The influence of graphene coating increases with decreasing static dielectric permittivity of the plate material and the characteristic frequency of an atomic dynamic polarizability. Simple analytic expressions for the classical limit of the Casimir-Polder free energy and force between an atom and a graphene-coated plate are obtained. From the comparison with the results of numerical computations, the application region of these expressions is determined.

  11. Microscopic picture of Co clustering in ZnO

    E-Print Network [OSTI]

    Iusan, Diana

    Density functional theory was applied to study the chemical and magnetic interactions between Co atoms doped in ZnO. It was found that the Co impurities tend to form nanoclusters and the interactions between these atoms ...

  12. Mechanisms of Nickel Sorption on Pyrophyllite: Macroscopic and Microscopic Approaches

    E-Print Network [OSTI]

    Sparks, Donald L.

    Mechanisms of Nickel Sorption on Pyrophyllite: Macroscopic and Microscopic Approaches Andre M adsorption are involved. In the higher pH region (pH >7), nickel sorption becomes slow and does not seem

  13. analytical electron microscope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ICCD Dual-Beam device IX 71 microscope filter focusing lens beam directing mirror beam expander LASER beam directing mirror 12;Here is an example of how we calculating Leuba,...

  14. Wolter mirror microscope : novel neutron focussing and imaging optic

    E-Print Network [OSTI]

    Bagdasarova, Yelena S. (Yelena Sergeyevna)

    2010-01-01T23:59:59.000Z

    In this thesis, I investigated the effectiveness of a Wolter Type I neutron microscope as a focusing and imaging device for thermal and cold neutrons sources by simulating the performance of the optics in a standard neutron ...

  15. abnormal electron microscopic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    OXIDE AS OBSERVED IN AN ELECTRON MICROSCOPE L Investigating (001) and (011) oriented monocrystalline thin foils of Cu2O in a conven- tional electron Abstracts 61. 80F 1....

  16. Development of a Scanning Probe Microscope and Studies of Graphene Grown on Copper

    E-Print Network [OSTI]

    Rasool, Haider Imad

    2012-01-01T23:59:59.000Z

    1: INTRODUCTION 1.1. BRIEF DISCUSSION OF SCANNING PROBEhighly stable electrochemical scanning probe microscope forincorporated it into a scanning probe microscope, performed

  17. Soft x-ray laser microscope. Final report

    SciTech Connect (OSTI)

    Suckewer, P.I.

    1990-10-01T23:59:59.000Z

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  18. Atomizing nozzle and method

    DOE Patents [OSTI]

    Ting, Jason (Ames, IA); Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2000-03-16T23:59:59.000Z

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  19. Optical atomic magnetometer

    DOE Patents [OSTI]

    Budker, Dmitry; Higbie, James; Corsini, Eric P

    2013-11-19T23:59:59.000Z

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  20. Design and performance of an ultra-high vacuum scanning tunneling microscope operating at dilution refrigerator temperatures and high magnetic fields

    E-Print Network [OSTI]

    Misra, Shashank; Drozdov, Ilya K; Seo, Jungpil; Gyenis, Andras; Kingsley, Simon C J; Jones, Howard; Yazdani, Ali

    2013-01-01T23:59:59.000Z

    We describe the construction and performance of a scanning tunneling microscope (STM) capable of taking maps of the tunneling density of states with sub-atomic spatial resolution at dilution refrigerator temperatures and high (14 T) magnetic fields. The fully ultra-high vacuum system features visual access to a two-sample microscope stage at the end of a bottom-loading dilution refrigerator, which facilitates the transfer of in situ prepared tips and samples. The two-sample stage enables location of the best area of the sample under study and extends the experiment lifetime. The successful thermal anchoring of the microscope, described in detail, is confirmed through a base temperature reading of 20 mK, along with a measured electron temperature of 250 mK. Atomically-resolved images, along with complementary vibration measurements, are presented to confirm the effectiveness of the vibration isolation scheme in this instrument. Finally, we demonstrate that the microscope is capable of the same level of perform...

  1. Force Modulator System

    SciTech Connect (OSTI)

    Redmond Clark

    2009-04-30T23:59:59.000Z

    Many metal parts manufacturers use large metal presses to shape sheet metal into finished products like car body parts, jet wing and fuselage surfaces, etc. These metal presses take sheet metal and - with enormous force - reshape the metal into a fully formed part in a manner of seconds. Although highly efficient, the forces involved in forming metal parts also damage the press itself, limit the metals used in part production, slow press operations and, when not properly controlled, cause the manufacture of large volumes of defective metal parts. To date, the metal-forming industry has not been able to develop a metal-holding technology that allows full control of press forces during the part forming process. This is of particular importance in the automotive lightweighting efforts under way in the US automotive manufacturing marketplace. Metalforming Controls Technology Inc. (MC2) has developed a patented press control system called the Force Modulator that has the ability to control these press forces, allowing a breakthrough in stamping process control. The technology includes a series of hydraulic cylinders that provide controlled tonnage at all points in the forming process. At the same time, the unique cylinder design allows for the generation of very high levels of clamping forces (very high tonnages) in very small spaces; a requirement for forming medium and large panels out of HSS and AHSS. Successful production application of these systems testing at multiple stamping operations - including Ford and Chrysler - has validated the capabilities and economic benefits of the system. Although this technology has been adopted in a number of stamping operations, one of the primary barriers to faster adoption and application of this technology in HSS projects is system cost. The cost issue has surfaced because the systems currently in use are built for each individual die as a custom application, thus driving higher tooling costs. This project proposed to better marry the die-specific Force Modulator technology with stamping presses in the form of a press cushion. This system would be designed to operate the binder ring for multiple parts, thus cutting the per-die cost of the technology. This study reports the results of technology field application. This project produced the following conclusions: (1) The Force Modulator system is capable of operating at very high tempos in the stamping environment; (2) The company can generate substantial, controlled holding tonnage (binder ring pressure) necessary to hold high strength steel parts for proper formation during draw operations; (3) A single system can be designed to operate with a family of parts, thus significantly reducing the per-die cost of a FM system; (4) High strength steel parts made with these systems appear to show significant quality improvements; (5) The amounts of steel required to make these parts is typically less than the amounts required with traditional blank-holding technologies; and (6) This technology will aid in the use of higher strength steels in auto and truck production, thus reducing weight and improving fuel efficiency.

  2. Self-consistent Green's functions with three-body forces

    E-Print Network [OSTI]

    Arianna Carbone

    2014-07-24T23:59:59.000Z

    The present thesis aims at studying the properties of symmetric nuclear and pure neutron matter from a Green's functions point of view, including two-body and three-body chiral forces. An extended self-consistent Green's function formalism is defined to consistently incorporate three-body forces in the many-body calculations. The effect of three-nucleon interactions is included via the construction of a dressed two-body density dependent force. This is obtained performing an average of the leading order three-body terms in the chiral effective field theory expansion. The dressed force corresponds to the use of an in-medium propagator in the average which takes into account the correlations characterizing the system at each stage of the many-body calculation. The total energy of the system is obtained by means of a modified Galitskii-Migdal-Koltun sumrule to correctly account for the effect of three-body forces. Microscopic as well as macroscopic properties of symmetric nuclear and pure neutron matter are analyzed in detailed.

  3. Atom-interferometry constraints on dark energy

    E-Print Network [OSTI]

    Hamilton, Paul; Haslinger, Philipp; Simmons, Quinn; Müller, Holger; Khoury, Justin

    2015-01-01T23:59:59.000Z

    If dark energy---which drives the accelerated expansion of the universe---consists of a new light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity. There has, however, been much theoretical progress in developing theories with screening mechanisms, which can evade detection by suppressing forces in regions of high density, such as the laboratory. One prominent example is the chameleon field. We reduce the effect of this screening mechanism by probing the chameleon with individual atoms rather than bulk matter. Using a cesium matter-wave interferometer near a spherical mass in an ultra-high vacuum chamber, we constrain a wide class of dynamical dark energy theories. Our experiment excludes a range of chameleon theories that reproduce the observed cosmic acceleration.

  4. Atomic mass compilation 2012

    SciTech Connect (OSTI)

    Pfeiffer, B., E-mail: bpfeiffe@uni-mainz.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Venkataramaniah, K. [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India)] [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India); Czok, U. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)] [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); Scheidenberger, C. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)

    2014-03-15T23:59:59.000Z

    Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

  5. Non-equilibrium structure and dynamics in a microscopic model of thin film active gels

    E-Print Network [OSTI]

    D. A. Head; W. J. Briels; G. Gompper

    2014-02-26T23:59:59.000Z

    In the presence of ATP, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modelling can help to quantify the relationship between individual motors plus filaments to organisation and dynamics on molecular and supra-molecular length scales. Here we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment and detachment, including a differential detachment rate from filament ends, reveals a range of non-equilibrium behaviour. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles or layers, whose stability depends on motor speed and differential end-detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit super-diffusive mass transport, where filament translocation scales with lag time with non-unique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end-detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modelling in the field of active gels.

  6. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    A. Deltuva

    2012-03-28T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  7. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    Deltuva, A

    2012-01-01T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  8. Sub-Poissonian atom number fluctuations using light-assisted collisions

    E-Print Network [OSTI]

    Y. R. P. Sortais; A. Fuhrmanek; R. Bourgain; A. Browaeys

    2012-01-23T23:59:59.000Z

    We investigate experimentally the number statistics of a mesoscopic ensemble of cold atoms in a microscopic dipole trap loaded from a magneto-optical trap, and find that the atom number fluctuations are reduced with respect to a Poisson distribution due to light-assisted two-body collisions. For numbers of atoms N>2, we measure a reduction factor (Fano factor) of 0.72+/-0.07, which differs from 1 by more than 4 standard deviations. We analyze this fact by a general stochastic model describing the competition between the loading of the trap from a reservoir of cold atoms and multi-atom losses, which leads to a master equation. Applied to our experimental regime, this model indicates an asymptotic value of 3/4 for the Fano factor at large N and in steady state. We thus show that we have reached the ultimate level of reduction in number fluctuations in our system.

  9. Relativistic forces in Lagangian mechanics

    E-Print Network [OSTI]

    J. Muñoz Díaz

    2012-06-07T23:59:59.000Z

    We give a general definition of \\emph{relativistic force} in the context of Lagrangian mechanics. Once this is done we prove that the only relativistic forces which are linear on the velocities are those coming from differential 2-forms defined on the configuration space. In this sense, electromagnetic fields provide a mechanical system with the simplest type of relativistic forces.

  10. Casimir force driven ratchets

    E-Print Network [OSTI]

    Thorsten Emig

    2007-01-26T23:59:59.000Z

    We explore the non-linear dynamics of two parallel periodically patterned metal surfaces that are coupled by the zero-point fluctuations of the electromagnetic field between them. The resulting Casimir force generates for asymmetric patterns with a time-periodically driven surface-to-surface distance a ratchet effect, allowing for directed lateral motion of the surfaces in sizeable parameter ranges. It is crucial to take into account inertia effects and hence chaotic dynamics which are described by Langevin dynamics. Multiple velocity reversals occur as a function of driving, mean surface distance, and effective damping. These transport properties are shown to be stable against weak ambient noise.

  11. Work Force Restructuring Activities

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy China 2015ofDepartment of EnergyThePatricia Hoffman is theDr.Ulrike1, 2014Force

  12. Probing Atomic Structure and Majorana Wavefunctions in Mono-Atomic Fe-chains on Superconducting Pb-Surface

    E-Print Network [OSTI]

    Pawlak, Remy; Klinovaja, Jelena; Meier, Tobias; Kawai, Shigeki; Glatzel, Thilo; Loss, Daniel; Meyer, Ernst

    2015-01-01T23:59:59.000Z

    Motivated by the striking promise of quantum computation, Majorana bound states (MBSs) in solid-state systems have attracted wide attention in recent years. In particular, the wavefunction localization of MBSs is a key feature and crucial for their future implementation as qubits. Here, we investigate the spatial and electronic characteristics of topological superconducting chains of iron atoms on the surface of Pb(110) by combining scanning tunneling microscopy (STM) and atomic force microscopy (AFM). We demonstrate that the Fe chains are mono-atomic, structured in a linear fashion, and exhibit zero-bias conductance peaks at their ends which we interprete as signature for a Majorana bound state. Spatially resolved conductance maps of the atomic chains reveal that the MBSs are well localized at the chain ends (below 25 nm), with two localization lengths as predicted by theory. Our observation lends strong support to use MBSs in Fe chains as qubits for quantum computing devices.

  13. Pairing forces in nuclei

    SciTech Connect (OSTI)

    Chasman, R.R. [Argonne National Lab., IL (United States). Physics Div.

    1996-12-31T23:59:59.000Z

    In this contribution, the author mentions some features of pairing forces that are unique to nuclei and cover some areas of major interest in nuclear structure research, that involve pairing. At the level of most nuclear structure studies, nuclei are treated as consisting of two kinds of fermions (protons and neutrons) in a valence space with rather few levels. These features give rise to unique aspects of pairing forces in nuclei: (1) n-p pairing in T = 0 as well as the usual T = 1 pairing that is characteristic of like fermions; (2) a need to correct pairing calculations for the (1/N) effects that can typically be neglected in superconducting solids. An issue of current concern is the nature of the pairing interaction: several recent studies suggest a need for a density dependent form of the pairing interaction. There is a good deal of feedback between the questions of accurate calculations of pairing interactions and the form and magnitude of the pairing interaction. Finally, the authors discuss some many-body wave functions that are a generalization of the BCS wave function form, and apply them to a calculation of energy level spacings in superdeformed rotational bands.

  14. Iowa Powder Atomization Technologies

    ScienceCinema (OSTI)

    None

    2013-03-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  15. Iowa Powder Atomization Technologies

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  16. Epoxy replication for Wolter x-ray microscope fabrication

    SciTech Connect (OSTI)

    Priedhorsky, W.

    1981-01-01T23:59:59.000Z

    An epoxy replica of a test piece designed to simulate a Wolter x-ray microscope geometry showed no loss of x-ray reflectivity or resolution, compared to the original. The test piece was a diamond-turned cone with 1.5/sup 0/ half angle. A flat was fly-cut on one side, then super- and conventionally polished. The replica was separated at the 1.5/sup 0/-draft angle, simulating a shallow angle Wolter microscope geometry. A test with 8.34 A x rays at 0.9/sup 0/ grazing angle showed a reflectivity of 67% for the replica flat surface, and 70% for the original. No spread of the reflected beam was observed with a 20-arc second wide test beam. This test verifies the epoxy replication technique for production of Wolter x-ray microscopes.

  17. Three-wire magnetic trap for direct forced evaporative cooling Shengwang Du1,* and Eun Oh2

    E-Print Network [OSTI]

    Du, Shengwang

    Three-wire magnetic trap for direct forced evaporative cooling Shengwang Du1,* and Eun Oh2 1 Kong, China 2 U.S. Naval Research Laboratory, Remote Sensing Division, Washington, D.C. 20375, USA potential for direct forced evaporative cooling of neutral atoms without using induced spin

  18. High-stability cryogenic scanning tunneling microscope based on a closed-cycle cryostat

    SciTech Connect (OSTI)

    Hackley, Jason D.; Kislitsyn, Dmitry A.; Beaman, Daniel K.; Nazin, George V., E-mail: gnazin@uoregon.edu [Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, Oregon 97403 (United States); Ulrich, Stefan [RHK Technology, Inc., 1050 East Maple Road, Troy, Michigan 48083 (United States)

    2014-10-15T23:59:59.000Z

    We report on the design and operation of a cryogenic ultra-high vacuum (UHV) scanning tunneling microscope (STM) coupled to a closed-cycle cryostat (CCC). The STM is thermally linked to the CCC through helium exchange gas confined inside a volume enclosed by highly flexible rubber bellows. The STM is thus mechanically decoupled from the CCC, which results in a significant reduction of the mechanical noise transferred from the CCC to the STM. Noise analysis of the tunneling current shows current fluctuations up to 4% of the total current, which translates into tip-sample distance variations of up to 1.5 picometers. This noise level is sufficiently low for atomic-resolution imaging of a wide variety of surfaces. To demonstrate this, atomic-resolution images of Au(111) and NaCl(100)/Au(111) surfaces, as well as of carbon nanotubes deposited on Au(111), were obtained. Thermal drift analysis showed that under optimized conditions, the lateral stability of the STM scanner can be as low as 0.18 Å/h. Scanning Tunneling Spectroscopy measurements based on the lock-in technique were also carried out, and showed no detectable presence of noise from the closed-cycle cryostat. Using this cooling approach, temperatures as low as 16 K at the STM scanner have been achieved, with the complete cool-down of the system typically taking up to 12 h. These results demonstrate that the constructed CCC-coupled STM is a highly stable instrument capable of highly detailed spectroscopic investigations of materials and surfaces at the atomic scale.

  19. Elements & Compounds Atoms (Elements)

    E-Print Network [OSTI]

    Frey, Terry

    #12;Elements & Compounds #12;Atoms (Elements) Molecules (Compounds) Cells Elements & Compounds #12 #12;First shell Second shell Third shell Hydrogen 1H Lithium 3Li Sodium 11Na Beryllium 4Be Magnesium energy Higher energy (a) A ball bouncing down a flight of stairs provides an analogy for energy levels

  20. Primary Atomization of a Liquid Jet in Crossflow

    E-Print Network [OSTI]

    Rana, Sandeep

    2010-01-01T23:59:59.000Z

    In this fluid dynamics video, we present a visualization of the primary atomization of a turbulent liquid jet injected into a turbulent gaseous crossflow. It is based on a detailed numerical simulation of the primary atomization region of the jet using a finite volume, balanced force, incompressible LES/DNS flow solver coupled to a Refined Level Set Grid (RLSG) solver to track the phase interface position. The visualization highlights the two distinct breakup modes of the jet: the column breakup mode of the main liquid column and the ligament breakup mode on the sides of the jet and highlights the complex evolution of the phase interface geometry.

  1. Dilution and resonance enhanced repulsion in non-equilibrium fluctuation forces

    E-Print Network [OSTI]

    Bimonte, Giuseppe; Kruger, Matthias; Kardar, Mehran

    2011-01-01T23:59:59.000Z

    In equilibrium, forces induced by fluctuations of the electromagnetic field between electrically polarizable objects (microscopic or macroscopic) in vacuum are always attractive. The force may, however, become repulsive for microscopic particles coupled to thermal baths with different temperatures. We demonstrate that this non-equilibrium repulsion can be realized also between macroscopic objects, as planar slabs, if they are kept at different temperatures. It is shown that repulsion can be enhanced by (i) tuning of material resonances in the thermal region, and by (ii) reducing the dielectric contrast due to "dilution". This can lead to stable equilibrium positions. We discuss the realization of these effects for aerogels, yielding repulsion down to sub-micron distances at realistic porosities.

  2. Dilution and resonance enhanced repulsion in non-equilibrium fluctuation forces

    E-Print Network [OSTI]

    Giuseppe Bimonte; Thorsten Emig; Matthias Kruger; Mehran Kardar

    2011-07-08T23:59:59.000Z

    In equilibrium, forces induced by fluctuations of the electromagnetic field between electrically polarizable objects (microscopic or macroscopic) in vacuum are always attractive. The force may, however, become repulsive for microscopic particles coupled to thermal baths with different temperatures. We demonstrate that this non-equilibrium repulsion can be realized also between macroscopic objects, as planar slabs, if they are kept at different temperatures. It is shown that repulsion can be enhanced by (i) tuning of material resonances in the thermal region, and by (ii) reducing the dielectric contrast due to "dilution". This can lead to stable equilibrium positions. We discuss the realization of these effects for aerogels, yielding repulsion down to sub-micron distances at realistic porosities.

  3. Atom-by-atom nucleation and growth of graphene nanopores

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Atom-by-atom nucleation and growth of graphene nanopores Christopher J. Russoa,b and J. A February 17, 2012 (received for review December 9, 2011) Graphene is an ideal thin membrane substrate structures in graphene with atomic preci- sion. It consists of inducing defect nucleation centers with ener

  4. Master equation for the probability distribution functions of forces in soft particle packings

    E-Print Network [OSTI]

    Kuniyasu Saitoh; Vanessa Magnanimo; Stefan Luding

    2014-11-05T23:59:59.000Z

    Employing molecular dynamics simulations of jammed soft particles, we study microscopic responses of force-chain networks to quasi-static isotropic (de)compressions. We show that not only contacts but also interparticle gaps between the nearest neighbors must be considered for the stochastic evolution of the probability distribution functions (PDFs) of forces, where the mutual exchange of contacts and interparticle gaps, i.e. opening and closing contacts, are also crucial to the incremental system behaviors. By numerically determining the transition rates for all changes of contacts and gaps, we formulate a Master equation for the PDFs of forces, where the insight one gets from the transition rates is striking: The mean change of forces reflects non-affine system response, while their fluctuations obey uncorrelated Gaussian statistics. In contrast, interparticle gaps are reacting mostly affine in average, but imply multi-scale correlations according to a wider stable distribution function.

  5. Construction of force measuring optical tweezers instrumentation and investigations of biophysical properties of bacterial adhesion organelles

    E-Print Network [OSTI]

    Andersson, Magnus

    2015-01-01T23:59:59.000Z

    Optical tweezers are a technique in which microscopic-sized particles, including living cells and bacteria, can be non-intrusively trapped with high accuracy solely using focused light. The technique has therefore become a powerful tool in the field of biophysics. Optical tweezers thereby provide outstanding manipulation possibilities of cells as well as semi-transparent materials, both non-invasively and non-destructively, in biological systems. In addition, optical tweezers can measure minute forces (< 10-12 N), probe molecular interactions and their energy landscapes, and apply both static and dynamic forces in biological systems in a controlled manner. The assessment of intermolecular forces with force measuring optical tweezers, and thereby the biomechanical structure of biological objects, has therefore considerably facilitated our understanding of interactions and structures of biological systems. Adhesive bacterial organelles, so called pili, mediate adhesion to host cells and are therefore crucial...

  6. Dynamic microscopic theory of fusion using DC-TDHF

    SciTech Connect (OSTI)

    Umar, A. S.; Oberacker, V. E.; Keser, R.; Maruhn, J. A.; Reinhard, P.-G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); RTE University, Science and Arts Faculty, Department of Physics, 53100, Rize (Turkey); Institut fuer Theoretische Physik, Goethe-Universitaet, D-60438 Frankfurt am Main (Germany); Institut fur Theoretische Physik, Universitat Erlangen, D-91054 Erlangen (Germany)

    2012-10-20T23:59:59.000Z

    The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a fully microscopic approach for calculating heavy-ion interaction potentials and fusion cross sections below and above the fusion barrier. We discuss recent applications of DC-TDHF method to fusion of light and heavy systems.

  7. Macro-microscopic mass formulae and nuclear mass predictions

    E-Print Network [OSTI]

    Boyer, Edmond

    Macro-microscopic mass formulae and nuclear mass predictions G. Royer, M. Guilbaud, A. Onillon manuscript, published in "Nuclear Physics A 847 (2010) 24-41" DOI : 10.1016/j.nuclphysa.2010.06.014 #12 including the pairing ef- fects have been firstly developed to reproduce the experimental nuclear masses [2

  8. SCANNING TUNNELING MICROSCOPE ASSEMBLY INSTRUCTIONS FOR NANOSCOPE II

    E-Print Network [OSTI]

    SCANNING TUNNELING MICROSCOPE ASSEMBLY INSTRUCTIONS FOR NANOSCOPE II 1) Set monitor #1 on top side of the able. 3) Set the keyboard on top and front of the computer. 4) Set the scanning head on gel into the scanning head. 12) Suspend bungee cords, as necessary, from a secure point in the ceiling. 13) Fasten onto

  9. Department of Mechanical Engineering "Heat Under the Microscope

    E-Print Network [OSTI]

    Militzer, Burkhard

    applications ranging from thermoelectric waste heat recovery to radio astronomy. BIOGRAPHY Austin MinnichDepartment of Mechanical Engineering presents "Heat Under the Microscope: Uncovering electronics. In many solids, heat is carried by phonons, or quanta of lattice vibrations. Compared to other

  10. Neutrinoless double beta decay in the microscopic interacting boson model

    SciTech Connect (OSTI)

    Iachello, F. [Center for Theoretical Physics, Sloane Physics Laboratory Yale University New Haven, CT 06520-8120 (United States)

    2009-11-09T23:59:59.000Z

    The results of a calculation of the nuclear matrix elements for neutrinoless double beta decay in the closure approximation in several nuclei within the framework of the microscopic interacting boson model (IBM-2) are presented and compared with those calculated in the shell model (SM) and quasiparticle random phase approximation (QRPA)

  11. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, S.; Skinner, C.H.; Rosser, R.

    1993-01-05T23:59:59.000Z

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  12. Atomic phenomena in dense plasmas

    SciTech Connect (OSTI)

    Weisheit, J.C.

    1981-03-01T23:59:59.000Z

    The following chapters are included: (1) the plasma environment, (2) perturbations of atomic structure, (3) perturbations of atomic collisions, (4) formation of spectral lines, and (5) dielectronic recombination. (MOW)

  13. Dynamic Force AFM (Asylum) | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    specifically for biological applications and can be used to: Study individual protein or DNA molecules in situ Image the surface of living cells Measure the adhesive forces of...

  14. Continuous Forcing Data, Darwin, Australia

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jakob, Christian

    Long term, large scale continuous forcing data set for three complete wet seasons (2004-2005, 2005-2006 and 2006-2007) in Darwin, Australia.

  15. atoms: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  16. Microscopic description of neutron emission rates in compound nuclei

    E-Print Network [OSTI]

    Yi Zhu; Junchen Pei

    2014-11-02T23:59:59.000Z

    The neutron emission rates in thermal excited nuclei are conventionally described by statistical models with a phenomenological level density parameter that depends on excitation energies, deformations and mass regions. In the microscopic view of hot nuclei, the neutron emission rates can be determined by the external neutron gas densities without any free parameters. Therefore the microscopic description of thermal neutron emissions is desirable that can impact several understandings such as survival probabilities of superheavy compound nuclei and neutron emissivity in reactors. To describe the neutron emission rates microscopically, the external thermal neutron gases are self-consistently obtained based on the Finite-Temperature Hartree-Fock-Bogoliubov (FT-HFB) approach. The results are compared with the statistical model to explore the connections between the FT-HFB approach and the statistical model. The Skyrme FT-HFB equation is solved by HFB-AX in deformed coordinate spaces. Based on the FT-HFB approach, the thermal properties and external neutron gas are properly described with the self-consistent gas substraction procedure. Then neutron emission rates can be obtained based on the densities of external neutron gases. The thermal statistical properties of $^{238}$U and $^{258}$U are studied in detail in terms of excitation energies. The thermal neutron emission rates in $^{238, 258}$U and superheavy compound nuclei $_{112}^{278}$Cn and $_{114}^{292}$Fl are calculated, which agree well with the statistical model by adopting an excitation-energy-dependent level density parameter. The coordinate-space FT-HFB approach can provide reliable microscopic descriptions of neutron emission rates in hot nuclei, as well as microscopic constraints on the excitation energy dependence of level density parameters for statistical models.

  17. Calibration of a single atom detector for atomic micro chips

    E-Print Network [OSTI]

    A. Stibor; S. Kraft; T. Campey; D. Komma; A. Günther; J. Fortágh; C. J. Vale; H. Rubinsztein-Dunlop; C. Zimmermann

    2007-02-13T23:59:59.000Z

    We experimentally investigate a scheme for detecting single atoms magnetically trapped on an atom chip. The detector is based on the photoionization of atoms and the subsequent detection of the generated ions. We describe the characterization of the ion detector with emphasis on its calibration via the correlation of ions with simultaneously generated electrons. A detection efficiency of 47.8% (+-2.6%) is measured, which is useful for single atom detection, and close to the limit allowing atom counting with sub-Poissonian uncertainty.

  18. A microfabricated atomic clock

    SciTech Connect (OSTI)

    Knappe, Svenja; Shah, Vishal; Schwindt, Peter D.D.; Hollberg, Leo; Kitching, John; Liew, Li-Anne; Moreland, John [Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States); Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States)

    2004-08-30T23:59:59.000Z

    Fabrication techniques usually applied to microelectromechanical systems (MEMS) are used to reduce the size and operating power of the core physics assembly of an atomic clock. With a volume of 9.5 mm{sup 3}, a fractional frequency instability of 2.5x10{sup -10} at 1 s of integration, and dissipating less than 75 mW of power, the device has the potential to bring atomically precise timing to hand-held, battery-operated devices. In addition, the design and fabrication process allows for wafer-level assembly of the structures, enabling low-cost mass-production of thousands of identical units with the same process sequence, and easy integration with other electronics.

  19. Delay in Atomic Photoionization

    SciTech Connect (OSTI)

    Kheifets, A. S. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106-4030 (United States); Ivanov, I. A. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia)

    2010-12-03T23:59:59.000Z

    We analyze the time delay between emission of photoelectrons from the outer valence ns and np subshells in noble gas atoms following absorption of an attosecond extreme ultraviolet pulse. Various processes such as elastic scattering of the photoelectron on the parent ion and many-electron correlation affect the apparent 'time zero' when the photoelectron leaves the atom. This qualitatively explains the time delay between photoemission from the 2s and 2p subshells of Ne as determined experimentally by attosecond streaking [Science 328, 1658 (2010)]. However, with our extensive numerical modeling, we were only able to account for less than half of the measured time delay of 21{+-}5 as. We argue that the extreme ultraviolet pulse alone cannot produce such a large time delay and it is the streaking IR field that is most likely responsible for this effect.

  20. Quantum Spin Ice and dimer models with Rydberg atoms

    E-Print Network [OSTI]

    Alexander W. Glaetzle; Marcello Dalmonte; Rejish Nath; Ioannis Rousochatzakis; Roderich Moessner; Peter Zoller

    2014-04-21T23:59:59.000Z

    Quantum spin ice represents a paradigmatic example on how the physics of frustrated magnets is related to gauge theories. In the present work we address the problem of approximately realizing quantum spin ice in two dimensions with cold atoms in optical lattices. The relevant interactions are obtained by weakly admixing van der Waals interactions between laser admixed Rydberg states to the atomic ground state atoms, exploiting the strong angular dependence of interactions between Rydberg p-states together with the possibility of designing step-like potentials. This allows us to implement Abelian gauge theories in a series of geometries, which could be demonstrated within state of the art atomic Rydberg experiments. We numerically analyze the family of resulting microscopic Hamiltonians and find that they exhibit both classical and quantum order by disorder, the latter yielding a quantum plaquette valence bond solid. We also present strategies to implement Abelian gauge theories using both s- and p-Rydberg states in exotic geometries, e.g. on a 4-8 lattice.

  1. Laser scattering by density fluctuations of ultra-cold atoms in a magneto-optical trap

    E-Print Network [OSTI]

    J. T. Mendonça; H. Terças

    2011-04-06T23:59:59.000Z

    We study the spectrum of density fluctuations in the ultra-cold gas of neutral atoms, confined in a magneto-optical trap. We determine the corresponding amplitude and spectra of laser light scattered by this medium. We derive an expression for the dynamical structure function, by using a test particle method. We propose to use the collective laser scattering as a diagnostic method for the microscopic properties of the ultra-cold matter. This will also allow us to check on the atomic correlations which are mediated by the collective mean field inside the gas.

  2. Air Force Enhanced Use Lease

    Broader source: Energy.gov (indexed) [DOE]

    S e r v i c e - E x c e l l e n c e Headquarters U.S. Air Force 1 Air Force Enhanced Use Lease Mr. Brian Brown 16 Oct. 12 I n t e g r i t y - S e r v i c e - E x c e l l e n c e 2...

  3. Air Force Renewable Energy Programs

    Broader source: Energy.gov (indexed) [DOE]

    in All We Do" I n t e g r i t y - S e r v i c e - E x c e l l e n c e THINK GREEN, BUILD GREEN, Topics Air Force Energy Use Air Force Facility Energy Center Current RE...

  4. Backaction-Driven Transport of Bloch Oscillating Atoms in Ring Cavities

    E-Print Network [OSTI]

    J. Goldwin; B. Prasanna Venkatesh; D. H. J. O'Dell

    2014-08-19T23:59:59.000Z

    We predict that an atomic Bose-Einstein condensate strongly coupled to an intracavity optical lattice can undergo resonant tunneling and directed transport when a constant and uniform bias force is applied. The bias force induces Bloch oscillations, causing amplitude and phase modulation of the lattice which resonantly modifies the site-to-site tunneling. For the right choice of parameters a net atomic current is generated. The transport velocity can be oriented oppositely to the bias force, with its amplitude and direction controlled by the detuning between the pump laser and the cavity. The transport can also be enhanced through imbalanced pumping of the two counter-propagating running wave cavity modes. Our results add to the cold atoms quantum simulation toolbox, with implications for quantum sensing and metrology.

  5. Optics and interferometry with atoms and molecules

    E-Print Network [OSTI]

    Cronin, Alexander D.

    Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic ...

  6. Whole-Cell Sensing for a Harmful Bloom-Forming Microscopic Alga by Measuring Antibody-Antigen Forces

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    I. I NTRODUCTION INGLE-CELLED microalgae play an essentialabundance of speci?c microalgae [10]–[13]. Early applicationand prokary- otic microalgae [3], [14]–[17]. These

  7. Design and Construction of a Low Temperature Scanning Tunneling Microscope 

    E-Print Network [OSTI]

    Chen, Chi

    2010-10-12T23:59:59.000Z

    and helium temperatures. We analyzed the operational electronic and vibration noises and made some effective improvements. To demonstrate the capabilities of the STM, we obtained atomically resolved images of the Au (111) and graphite surfaces. In addition...

  8. Microsoft Word - Equipment-Training List

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scanning and Probing Microscopy Environmental Closed Loop Atomic Force Microscope - Asylum MFD-3D-BIO CFN Safety Module for Users - NC-ESH-USERS Cyber Security Training -...

  9. Simulation of High Density Pedestrian Flow: Microscopic Model

    E-Print Network [OSTI]

    Dridi, Mohamed H

    2015-01-01T23:59:59.000Z

    In recent years modelling crowd and evacuation dynamics has become very important, with increasing huge numbers of people gathering around the world for many reasons and events. The fact that our global population grows dramatically every year and the current public transport systems are able to transport large amounts of people, heightens the risk of crowd panic or crush. Pedestrian models are based on macroscopic or microscopic behaviour. In this paper, we are interested in developing models that can be used for evacuation control strategies. This model will be based on microscopic pedestrian simulation models, and its evolution and design requires a lot of information and data. The people stream will be simulated, based on mathematical models derived from empirical data about pedestrian flows. This model is developed from image data bases, so called empirical data, taken from a video camera or data obtained using human detectors. We consider the individuals as autonomous particles interacting through socia...

  10. Microscopic analysis of fusion hindrance in heavy systems

    E-Print Network [OSTI]

    Washiyama, Kouhei

    2015-01-01T23:59:59.000Z

    Background: Heavy-ion fusion reactions involving heavy nuclei at energies around the Coulomb barrier exhibit fusion hindrance, where the probability of compound nucleus formation is strongly hindered compared with that in light- and medium-mass systems. The origin of this fusion hindrance has not been well understood from a microscopic point of view. Purpose: Analyze the fusion dynamics in heavy systems by a microscopic reaction model and understand the origin of the fusion hindrance. Method: We employ the time-dependent Hartree-Fock (TDHF) theory. We extract nucleus--nucleus potential and energy dissipation by the method combining TDHF dynamics of the entrance channel of fusion reactions with one-dimensional Newton equation including a dissipation term. Then, we analyze the origin of the fusion hindrance using the properties of the extracted potential and energy dissipation. Results: Extracted potentials show monotonic increase as the relative distance of two nuclei decreases, which induces the disappearance...

  11. Prospective study on microscopic potential with Gogny interaction

    E-Print Network [OSTI]

    Blanchon, G; Arellano, H F

    2015-01-01T23:59:59.000Z

    We present our current studies and our future plans on microscopic potential based on effective nucleon-nucleon interaction and many-body theory. This framework treats in an unified way nuclear structure and reaction. It offers the opportunity to link the underlying effective interaction to nucleon scattering observables. The more consistently connected to a variety of reaction and structure experimental data the framework will be, the more constrained effective interaction will be. As a proof of concept, we present some recent results for both neutron and proton scattered from spherical target nucleus, namely 40 Ca, using the Gogny D1S interaction. Possible fruitful crosstalks between microscopic potential, phenomenological potential and effective interaction are exposed. We then draw some prospective plans for the forthcoming years including scattering from spherical nuclei experiencing pairing correlations, scattering from axially deformed nuclei, and new effective interaction with reaction constraints.

  12. X-ray microscope assemblies. Final report and metrology report

    SciTech Connect (OSTI)

    Zehnpfennig, T.F.

    1981-04-13T23:59:59.000Z

    This is the Final Report and Metrology Report prepared under Lawrence Livermore Laboratory Subcontract 9936205, X-ray Microscope Assemblies. The purpose of this program was to design, fabricate, and perform detailed metrology on an axisymmetric grazing-incidence x-ray microscope (XRMS) to be used as a diagnostic instrument in the Lawrence Livermore Laser Fusion Program. The optical configuration chosen for this device consists of two internally polished surfaces of revolution: an hyperboloid facing the object; and a confocal, co-axial elliposid facing the image. This arrangement is known as the Wolter Type-I configuration. The grazing angle of reflection for both surfaces is approximately 1/sup 0/. The general optical performance goals under this program were to achieve a spatial resolution in the object plane in the soft x-ray region of approximately 1 micron, and to achieve an effective solid collecting angle which is an appreciable fraction of the geometric solid collecting angle.

  13. An Advanced Ultra-Low Temperature Scanning Probe Microscope

    E-Print Network [OSTI]

    An Advanced Ultra-Low Temperature Scanning Probe Microscope P R O J E C T L E A D E R : Joseph); Steven Blankenship, Alan Band (NIST) G O A L To develop an ultra-high vacuum, ultra-low temperature, high of subpicometer stability and can operate in ultra-high vacuum at 10 mK, and in magnetic fields up to 15 T

  14. The Ultra-High Vacuum, Low-Temperature Scanning Probe Microscope...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Ultra-High Vacuum, Low-Temperature Scanning Probe Microscope in EMSL's Quiet Wing The Ultra-High Vacuum, Low-Temperature Scanning Probe Microscope in EMSL's Quiet Wing This is...

  15. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumni AlumniFederalAshley BoyleAn overhead viewAtom-split it

  16. Microscopic thermal diffusivity mapping using an infrared camera

    SciTech Connect (OSTI)

    Wang, H.; Dinwiddie, R.B.

    1997-12-31T23:59:59.000Z

    Standard flash thermal diffusivity measurements utilize a single-point infrared detector to measure the average temperature rise of the sample surface after a heat pulse. The averaging of infrared radiation over the sample surface could smear out the microscopic thermal diffusivity variations in some specimens, especially in fiber-reinforced composite materials. A high-speed, high-sensitivity infrared camera was employed in this study of composite materials. With a special microscope attachment, the spatial resolution of the camera can reach 5.4 {micro}m. The images can then be processed to generate microscopic thermal diffusivity maps of the material. SRM 1462 stainless steel was tested to evaluate the accuracy of the system. Thermal diffusivity micrographs of carbon-carbon composites and SCS-6/borosilicate glass were generated. Thermal diffusivity values of the carbon fiber bundles parallel to the heat flow were found to be higher than the matrix material. A thermal coupling effect between SCS-6 fiber and matrix was observed. The thermal coupling and measured thermal diffusivity value of the fiber were also dependent upon the thickness of the specimen.

  17. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Anlage, Steven [University of Maryland

    2014-07-23T23:59:59.000Z

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  18. Le magn)sme ar)ficiel pour les gaz d'atomes froids

    E-Print Network [OSTI]

    Dalibard, Jean

    Le magné)sme ar)ficiel pour les gaz d'atomes froids Jean Dalibard Année 2013-14 Chaire Atomes et rayonnement #12;Thème général du cours : le magné?sme = q v B = 0 perdu d'avance ? pas forcément... On peut émuler ce magné?sme par

  19. A next-generation EUV Fresnel zoneplate mask-imaging microscope

    E-Print Network [OSTI]

    Goldberg, Kenneth A.

    2012-01-01T23:59:59.000Z

    A next-generation EUV Fresnel zoneplate mask-imaginghigh-magnification all-EUV Fresnel zoneplate microscope, the

  20. Spectra of helium clusters with up to six atoms using soft core potentials

    E-Print Network [OSTI]

    M. Gattobigio; A. Kievsky; M. Viviani

    2011-12-01T23:59:59.000Z

    In this work we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with $A=2,3,4,5,6$ atoms with an inter-particle potential which does not present a strong repulsion at short distances. We use an attractive gaussian potential that reproduces the values of the dimer binding energy, the atom-atom scattering length, and the effective range obtained with one of the widely used He-He interactions, the LM2M2 potential. In systems with more than two atoms we consider a repulsive three-body force that, by construction, reproduces the trimer binding energy of the LM2M2 potential. With this model, consisting in the sum of a two- and three-body potential, we have calculated the spectrum of clusters formed by four, five and six helium atoms. We have found that these systems present two bound states, one deep and one shallow close to the threshold fixed by the energy of the $(A-1)$-atom system. Universal relations between the energies of the excited state of the $A$-atom system and the ground state energy of the $(A-1)$-atom system are extracted as well as the ratio between the ground state of the $A$-atom system and the ground state energy of the trimer.

  1. Spectra of helium clusters with up to six atoms using soft-core potentials

    SciTech Connect (OSTI)

    Gattobigio, M. [Universite de Nice-Sophia Antipolis, Institut Non-Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Kievsky, A.; Viviani, M. [Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa (Italy)

    2011-11-15T23:59:59.000Z

    In this paper, we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with A=2,3,4,5,6 atoms with an interparticle potential which does not present a strong repulsion at short distances. We use an attractive Gaussian potential that reproduces the values of the dimer binding energy, the atom-atom scattering length, and the effective range obtained with one of the widely used He-He interactions, the Aziz and Slaman potential, called LM2M2. In systems with more than two atoms, we consider a repulsive three-body force that, by construction, reproduces the trimer binding energy of the LM2M2 potential. With this model, consisting of the sum of a two- and three-body potential, we have calculated the spectrum of clusters formed by four, five, and six helium atoms. We have found that these systems present two bound states, one deep and one shallow, close to the threshold fixed by the energy of the (A-1)-atom system. Universal relations between the energies of the excited state of the A-atom system and the ground-state energy of the (A-1)-atom system are extracted, as well as the ratio between the ground state of the A-atom system and the ground-state energy of the trimer.

  2. Atomic Energy Commission Takes Over Responsibility for all Atomic...

    National Nuclear Security Administration (NNSA)

    Takes Over Responsibility for all Atomic Energy Programs | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile...

  3. Synchrotron infrared confocal microscope: Application to infrared 3D spectral imaging

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Synchrotron infrared confocal microscope: Application to infrared 3D spectral imaging F Jamme1, 2 coupled to an infrared microscope allows imaging at the so-called diffraction limit. Thus, numerous infrared beamlines around the world have been developed for infrared chemical imaging. Infrared microscopes

  4. Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction

    E-Print Network [OSTI]

    Zollman, Dean

    Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction

  5. Scanning Electron Microscope Image Signal-to-Noise Ratio Monitoring for Micro-Nanomanipulation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Scanning Electron Microscope Image Signal-to-Noise Ratio Monitoring for Micro ROBOTEX (ANR-10-EQPX-44-01) projects. Key words: Scanning electron microscope, signal-to-noise ratio system, scanning electron microscope (SEM) performs an important role in autonomous micro

  6. An EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm

    E-Print Network [OSTI]

    An EUV Fresnel zoneplate mask-imaging microscope for lithography generations reaching 8 nm Kenneth lithography design rules. The proposed microscope features an array of user-selectable Fresnel zoneplate-EUV, Fresnel zoneplate microscope, the AIT has been in the vanguard of high-resolution EUV mask imaging

  7. Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures

    E-Print Network [OSTI]

    van der Wal, Caspar H.

    Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport with 1 m spatial resolution. The microscope was designed to study spin transport, a critical issue-temperature optical microscope, elec- tromagnet and cryogenic cell with cold finger to measure continuous-wave cw

  8. Artificial Tribotactic Microscopic Walkers: Walking Based on Friction Gradients

    E-Print Network [OSTI]

    Steimel, Joshua P.

    Friction, the resistive force between two surfaces sliding past each other, is at the core of a wide diversity of locomotion schemes. While such schemes are well described for homogeneous environments, locomotion based on ...

  9. Quantum transport in ultracold atoms

    E-Print Network [OSTI]

    Chih-Chun Chien; Sebastiano Peotta; Massimiliano Di Ventra

    2015-04-11T23:59:59.000Z

    Ultracold atoms confined by engineered magnetic or optical potentials are ideal systems for studying phenomena otherwise difficult to realize or probe in the solid state because their atomic interaction strength, number of species, density, and geometry can be independently controlled. This review focuses on quantum transport phenomena in atomic gases that mirror and oftentimes either better elucidate or show fundamental differences with those observed in mesoscopic and nanoscopic systems. We discuss significant progress in performing transport experiments in atomic gases, contrast similarities and differences between transport in cold atoms and in condensed matter systems, and survey inspiring theoretical predictions that are difficult to verify in conventional setups. These results further demonstrate the versatility offered by atomic systems in the study of nonequilibrium phenomena and their promise for novel applications.

  10. Protective Force Firearms Qualification Courses

    Broader source: Energy.gov (indexed) [DOE]

    points; Protective Force Firearms Qualification Courses Section A Appendix 4 July 2011 4-3 d. a projectile print within or cutting the outer ring is 2 points; and e. a projectile...

  11. A 30 mK, 13.5 T scanning tunneling microscope with two independent tips

    SciTech Connect (OSTI)

    Roychowdhury, Anita [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States) [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States); Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States); Gubrud, M. A.; Dana, R.; Dreyer, M. [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States)] [Laboratory for Physical Sciences, College Park, Maryland 20742 (United States); Anderson, J. R.; Lobb, C. J.; Wellstood, F. C. [Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States)] [Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20740 (United States)

    2014-04-15T23:59:59.000Z

    We describe the design, construction, and performance of an ultra-low temperature, high-field scanning tunneling microscope (STM) with two independent tips. The STM is mounted on a dilution refrigerator and operates at a base temperature of 30 mK with magnetic fields of up to 13.5 T. We focus on the design of the two-tip STM head, as well as the sample transfer mechanism, which allows in situ transfer from an ultra high vacuum preparation chamber while the STM is at 1.5 K. Other design details such as the vibration isolation and rf-filtered wiring are also described. Their effectiveness is demonstrated via spectral current noise characteristics and the root mean square roughness of atomic resolution images. The high-field capability is shown by the magnetic field dependence of the superconducting gap of Cu{sub x}Bi{sub 2}Se{sub 3}. Finally, we present images and spectroscopy taken with superconducting Nb tips with the refrigerator at 35 mK that indicate that the effective temperature of our tips/sample is approximately 184 mK, corresponding to an energy resolution of 16 ?eV.

  12. Prediction of vehicle impact forces

    E-Print Network [OSTI]

    Kaderka, Darrell Laine

    1990-01-01T23:59:59.000Z

    PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject...: Civil Engineering PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Approved as to style and content by: C. Eugene Buth (Chair of Committee) W. ynn Beason (Member) I? D n E. B ay (Member) es T. P. Yao (Departmen Head) May...

  13. Prediction of vehicle impact forces 

    E-Print Network [OSTI]

    Kaderka, Darrell Laine

    1990-01-01T23:59:59.000Z

    PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject...: Civil Engineering PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Approved as to style and content by: C. Eugene Buth (Chair of Committee) W. ynn Beason (Member) I? D n E. B ay (Member) es T. P. Yao (Departmen Head) May...

  14. Testing Gravity with Cold-Atom Interferometers

    E-Print Network [OSTI]

    G. W. Biedermann; X. Wu; L. Deslauriers; S. Roy; C. Mahadeswaraswamy; M. A. Kasevich

    2014-12-10T23:59:59.000Z

    We present a horizontal gravity gradiometer atom interferometer for precision gravitational tests. The horizontal configuration is superior for maximizing the inertial signal in the atom interferometer from a nearby proof mass. In our device, we have suppressed spurious noise associated with the horizonal configuration to achieve a differential acceleration sensitivity of 4.2$\\times10^{-9}g/\\sqrt{Hz}$ over a 70 cm baseline or 3.0$\\times10^{-9}g/\\sqrt{Hz}$ inferred per accelerometer. Using the performance of this instrument, we characterize the results of possible future gravitational tests. We complete a proof-of-concept measurement of the gravitational constant with a precision of 3$\\times10^{-4}$ that is competitive with the present limit of 1.2$\\times10^{-4}$ using other techniques. From this measurement, we provide a statistical constraint on a Yukawa-type fifth force at 8$\\times$10$^{-3}$ near the poorly known length scale of 10 cm. Limits approaching 10$^{-5}$ appear feasible. We discuss improvements that can enable uncertainties falling well below 10$^{-5}$ for both experiments.

  15. String model of the Hydrogen Atom

    E-Print Network [OSTI]

    Omar Yepez

    2007-01-31T23:59:59.000Z

    A non-moving electron hydrogen model is proposed, resolving a long standing contradiction (94 years) in the hydrogen atom. This, however, forces to not use the "in an orbit point particle kinetic energy" as the phenomenon responsible for the atom stability. The repulsion between the masses of the electron and proton is what is responsible of such stability. The mass of the electron is a field fully described by the uncertainty principle through the confinement of the particle, which is also consistent with the general theory of relativity that states: "mass-energy tells the space how to bend". Ergo, mass exerts a tension on its surrounding space and the lighter the mass the larger the space it will occupy. Based on this concept it is proposed that the orbital is the electron. The electron's orbitals are just the electron's different ways of intersecting the space; with different magnetic momenta. The coupling of this momenta with the magnetic moment of the proton finally explains the hyperfine structure of the hydrogen spectrum with an overwhelming simplicity

  16. Strong wind forcing of the ocean

    E-Print Network [OSTI]

    Zedler, Sarah E.

    2007-01-01T23:59:59.000Z

    latitudes, tropical storm force winds may be sufficient tolocation where hurricane force winds arrive at the region.shear data. The wind stress used to force these model was

  17. Spin-Flavor van der Waals Forces and NN interaction

    SciTech Connect (OSTI)

    Alvaro Calle Cordon, Enrique Ruiz Arriola

    2011-12-01T23:59:59.000Z

    A major goal in Nuclear Physics is the derivation of the Nucleon-Nucleon (NN) interaction from Quantum Chromodynamics (QCD). In QCD the fundamental degrees of freedom are colored quarks and gluons which are confined to form colorless strongly interacting hadrons. Because of this the resulting nuclear forces at sufficiently large distances correspond to spin-flavor excitations, very much like the dipole excitations generating the van der Waals (vdW) forces acting between atoms. We study the Nucleon-Nucleon interaction in the Born-Oppenheimer approximation at second order in perturbation theory including the Delta resonance as an intermediate state. The potential resembles strongly chiral potentials computed either via soliton models or chiral perturbation theory and has a van der Waals like singularity at short distances which is handled by means of renormalization techniques. Results for the deuteron are discussed.

  18. Thermal Issues in Casimir Forces Between Conductors and Semiconductors

    E-Print Network [OSTI]

    K. A. Milton; Iver Brevik; Simen A. Ellingsen

    2012-07-20T23:59:59.000Z

    The Casimir effect between metal surfaces has now been well-verified at the few-percent level experimentally. However, the temperature dependence has never been observed in the laboratory, since all experiments are conducted at room temperature. The temperature dependence for the related Casimir-Polder force between an atom and a bulk material has, in contrast, been observed between a BEC and a silica substrate, with the environment and the silica held at different temperatures. There is a controversy about the temperature dependence for the force between metals, having to do with the magnitude of the linear temperature term for both low and high temperature, the latter being most prominent at large distances. There are also related anomalies pertaining to semiconductors. The status of this controversy, and of the relevant experiments, are reviewed in this report.

  19. Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion

    E-Print Network [OSTI]

    Subhadeep Gupta; Kevin L. Moore; Kater W. Murch; Dan M. Stamper-Kurn

    2007-09-05T23:59:59.000Z

    We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to $10^5$ $^{87}$Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.

  20. The use of atomic level stress to characterize the structure of irradiated iron

    SciTech Connect (OSTI)

    Egami, Takeshi [ORNL] [ORNL; Ojha, Madhusudan [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Nicholson, Donald M. [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Odbadrakh, Khorgolkhuu [ORNL] [ORNL; Radhakrishnan, Bala [ORNL] [ORNL; Stoller, Roger E [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    The behaviour of irradiated material near a primary knock on atom immediately after impact is of great importance for designing reactor materials. Currently, molecular dynamics simulations with classical force fields provide the foundation for understanding the resulting cascade. However, modern density functional calculations can now treat large enough numbers of atoms that they can provide additional details of the magnetic and electronic nature of irradiated samples. In this paper we calculate from first principles the atomic level stresses for an instantaneous configuration following the initiation of a low energy cascade in iron.

  1. Ab-initio friction forces on the nanoscale: A DFT study of fcc Cu(111)

    E-Print Network [OSTI]

    Wolloch, Michael; Mohn, Peter; Redinger, Josef; Vernes, András

    2014-01-01T23:59:59.000Z

    While there are a number of models that tackle the problem of calculating friction forces on the atomic level, providing a completely parameter-free approach remains a challenge. Here we present a quasi-static model to obtain an approximation to the nanofrictional response of dry, wearless systems based on quantum mechanical all-electron calculations. We propose a mechanism to allow dissipative sliding, which relies on atomic relaxations. We define two different ways of calculating the mean nanofriction force, both leading to an exponential friction-versus-load behavior for all sliding directions. Since our approach does not impose any limits on lengths and directions of the sliding paths, we investigate arbitrary sliding directions for an fcc Cu(111) interface and detect two periodic paths which form the upper and lower bound of nanofriction. For long aperiodic paths the friction force convergences to a value in between these limits. For low loads we retrieve the Derjaguin generalization of Amontons-Coulomb ...

  2. Observation of a single-beam gradient force acoustical trap for elastic particles: acoustical tweezers

    E-Print Network [OSTI]

    Baresch, Diego; Marchiano, Régis

    2014-01-01T23:59:59.000Z

    The ability to manipulate matter precisely is critical for the study and development of a large variety of systems. Optical tweezers are excellent tools to handle particles ranging in size from a few micrometers to hundreds of nanometers but become inefficient and damaging on larger objects. We demonstrate for the first reported time the trapping of elastic particles by the large gradient force of a single acoustical beam in three dimensions. We show that at equal power, acoustical forces overtake by 8 orders of magnitude that of optical ones on macroscopic objects. Acoustical tweezers can push, pull and accurately control both the position of the particle and the forces exerted under damage-free conditions. The large spectrum of frequencies covered by coherent ultrasonic sources will provide a wide variety of manipulation possibilities from macro- to microscopic length scales. We believe our observations improve the prospects for wider use of non-contact manipulation in biology, biophysics, microfluidics and...

  3. Towards secondary ion mass spectrometry on the helium ion microscope: An experimental and simulation based feasibility study with He{sup +} and Ne{sup +} bombardment

    SciTech Connect (OSTI)

    Wirtz, T.; Vanhove, N.; Pillatsch, L.; Dowsett, D. [Department of Science and Analysis of Materials (SAM), Centre de Recherche Public - Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Sijbrandij, S.; Notte, J. [Carl Zeiss NTS LLC, One Corporation Way, Peabody, Massachusetts 01960 (United States)

    2012-07-23T23:59:59.000Z

    The combination of the high-brightness He{sup +}/Ne{sup +} atomic level ion source with secondary ion mass spectrometry detection capabilities opens up the prospect of obtaining chemical information with high lateral resolution and high sensitivity on the Zeiss ORION helium ion microscope. The analytical performance in terms of sputtering yield, useful yield, and detection limit is studied and subsequently optimized by oxygen and cesium flooding. Detection limits down to 10{sup -6} and 10{sup -5} can be obtained for silicon using Ne{sup +} and He{sup +}, respectively. A simulation based study reveals furthermore that a lateral resolution <10 nm can be obtained.

  4. Coherent Atom Optics with fast metastable rare gas atoms

    SciTech Connect (OSTI)

    Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Vassilev, G.; Ducloy, M. [Laboratoire de Physique des Lasers, Universite Paris 13, Avenue J.B. Clement, 93430-Villetaneuse (France); Bocvarski, V. [Institute of Physics, Pregrevica 118, 11080 - Belgrade-Zemun (Serbia and Montenegro)

    2006-12-01T23:59:59.000Z

    Coherent atom optics experiments making use of an ultra-narrow beam of fast metastable atoms generated by metastability exchange are reported. The transverse coherence of the beam (coherence radius of 1.7 {mu}m for He*, 1.2 {mu}m for Ne*, 0.87 {mu}m for Ar*) is demonstrated via the atomic diffraction by a non-magnetic 2{mu}m-period reflection grating. The combination of the non-scalar van der Waals (vdW) interaction with the Zeeman interaction generated by a static magnetic field gives rise to ''vdW-Zeeman'' transitions among Zeeman sub-levels. Exo-energetic transitions of this type are observed with Ne*(3P2) atoms traversing a copper micro-slit grating. They can be used as a tunable beam splitter in an inelastic Fresnel bi-prism atom interferometer.

  5. U.S. Air Force Fact Sheet Air Force Reserve Officer Training Corps

    E-Print Network [OSTI]

    Su, Xiao

    U.S. Air Force Fact Sheet Air Force Reserve Officer Training Corps Mission Develop Quality Leaders for the Air Force. Personnel and Resources Air Force Reserve Officer Training Corps (ROTC) includes four,796 new Second Lieutenants who entered active duty in the United States Air Force. Organization Air Force

  6. Forces in electromagnetic field and gravitational field

    E-Print Network [OSTI]

    Zihua Weng

    2011-03-31T23:59:59.000Z

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in the interplanetary space between the sun and the earth.

  7. 15 LINES II -Wavelength-Dependent Line Opacities Relation of Microscopic Atomic Parameters to Macroscopic Extinction Coefficients

    E-Print Network [OSTI]

    Sitko, Michael L.

    Broadening For an observer viewing a gas, the radial component of the maxwellian velocity distribution to other effects. #12;3 Pressure (Collisional) Broadening Classically, this can be viewed as the effects of by the ensemble of nearby particles To first order: = c 4 2 0( )+ c 4 2 , where c = 2 MFTcollisions Doppler

  8. Microscopic analysis of order parameters in nuclear quantum phase transitions

    SciTech Connect (OSTI)

    Li, Z. P. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Physics Department, Faculty of Science, University of Zagreb, HR-10000 Zagreb (Croatia); Niksic, T. [Physics Department, Faculty of Science, University of Zagreb, HR-10000 Zagreb (Croatia); Vretenar, D. [Physics Department, Faculty of Science, University of Zagreb, HR-10000 Zagreb (Croatia); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Meng, J. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China)

    2009-12-15T23:59:59.000Z

    Microscopic signatures of nuclear ground-state shape phase transitions in Nd isotopes are studied using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom, with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial shapes. As a function of the physical control parameter, the number of nucleons, energy gaps between the ground state and the excited vibrational states with zero angular momentum, isomer shifts, and monopole transition strengths exhibit sharp discontinuities at neutron number N=90, which is characteristic of a first-order quantum phase transition.

  9. Relativistic Viscous Fluid Description of Microscopic Black Hole Wind

    E-Print Network [OSTI]

    J. I. Kapusta

    2001-05-25T23:59:59.000Z

    Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. Whether or not a quasi-stationary shell of matter undergoing radial hydrodynamic expansion surrounds such black holes is been controversial. In this paper relativistic viscous fluid equations are applied to the problem. It is shown that a self-consistent picture emerges of a fluid just marginally kept in local thermal equilibrium; viscosity is a crucial element of the dynamics.

  10. A Kirkpatrick-Baez microscope for the National Ignition Facility

    SciTech Connect (OSTI)

    Pickworth, L. A., E-mail: pickworth1@llnl.gov; McCarville, T.; Decker, T.; Pardini, T.; Ayers, J.; Bell, P.; Bradley, D.; Brejnholt, N. F.; Izumi, N.; Mirkarimi, P.; Pivovaroff, M.; Smalyuk, V.; Vogel, J.; Walton, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kilkenny, J. [General Atomics, San Diego, California 92121 (United States)

    2014-11-15T23:59:59.000Z

    Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10–25 ?m) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 ?m resolution over a 300 ?m field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 ?m field of view.

  11. A simple microscopic model for the dynamics of adhesive failure

    E-Print Network [OSTI]

    Dominic Vella; L. Mahadevan

    2005-12-27T23:59:59.000Z

    We consider a microscopic model for the failure of soft adhesives in tension based on ideas of bond rupture under dynamic loading. Focusing on adhesive failure under loading at constant velocity, we demonstrate that bi-modal curves of stress against strain may occur due to effects of finite polymer chain or bond length and characterise the loading conditions under which such bi-modal behaviour is observed. The results of this analysis are in qualitative agreement with experiments performed on unconfined adhesives in which failure does not occur by cavitation.

  12. Bogoliubov theory and bosonic atoms

    E-Print Network [OSTI]

    Phan Thanh Nam

    2011-09-13T23:59:59.000Z

    We formulate the Bogoliubov variational principle in a mathematical framework similar to the generalized Hartree-Fock theory. Then we analyze the Bogoliubov theory for bosonic atoms in details. We discuss heuristically why the Bogoliubov energy should give the first correction to the leading energy of large bosonic atoms.

  13. In-situ control system for atomization

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Terpstra, R.L.

    1995-06-13T23:59:59.000Z

    Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray is disclosed. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray. 3 figs.

  14. Spectral Emission of Moving Atom

    E-Print Network [OSTI]

    J. X. Zheng-Johansson

    2008-03-17T23:59:59.000Z

    A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the spectral emission of a moving atom exhibits always a redshift which informs not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a portion of its internal energy on transiting to a lower-energy state which however has in a moving atom an additional energy gain; this results in a redshift in the emission frequency. Based on auxiliary experimental information and a scheme for de Broglie particle formation, we give a vigorous elucidation of the mechanism for deceleration radiation of atomic electron; the corresponding prediction of the redshift is in complete agreement with the Ives and Stilwell's experimental formula.

  15. Nonlocal microscopic theory of quantum friction between parallel metallic slabs

    SciTech Connect (OSTI)

    Despoja, Vito [Donostia International Physics Center (DIPC), P. Manuel de Lardizabal, E-20018 San Sebastian, Basque Country (Spain); Department of Physics, University of Zagreb, Bijenicka 32, HR-10000 Zagreb (Croatia); Departamento de Fisica de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Quimicas, Universidad del Pais Vasco UPV/EHU, Apto. 1072, E-20080 San Sebastian, Basque Country (Spain); Echenique, Pedro M. [Donostia International Physics Center (DIPC), P. Manuel de Lardizabal, E-20018 San Sebastian, Basque Country (Spain); Departamento de Fisica de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Quimicas, Universidad del Pais Vasco UPV/EHU, Apto. 1072, E-20080 San Sebastian, Basque Country (Spain); Sunjic, Marijan [Donostia International Physics Center (DIPC), P. Manuel de Lardizabal, E-20018 San Sebastian, Basque Country (Spain); Department of Physics, University of Zagreb, Bijenicka 32, HR-10000 Zagreb (Croatia)

    2011-05-15T23:59:59.000Z

    We present a new derivation of the friction force between two metallic slabs moving with constant relative parallel velocity, based on T=0 quantum-field theory formalism. By including a fully nonlocal description of dynamically screened electron fluctuations in the slab, and avoiding the usual matching-condition procedure, we generalize previous expressions for the friction force, to which our results reduce in the local limit. Analyzing the friction force calculated in the two local models and in the nonlocal theory, we show that for physically relevant velocities local theories using the plasmon and Drude models of dielectric response are inappropriate to describe friction, which is due to excitation of low-energy electron-hole pairs, which are properly included in nonlocal theory. We also show that inclusion of dissipation in the nonlocal electronic response has negligible influence on friction.

  16. Supersonic coal water slurry fuel atomizer

    DOE Patents [OSTI]

    Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA); Balsavich, John (Foxborough, MA)

    1991-01-01T23:59:59.000Z

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  17. Coherent control of light transport in a dense and disordered atomic ensemble

    E-Print Network [OSTI]

    A. S. Sheremet; D. F. Kornovan; L. V. Gerasimov; B. Gouraud; J. Laurat; D. V. Kupriyanov

    2015-03-09T23:59:59.000Z

    Light transport in a dense and disordered cold atomic ensemble, where the cooperation of atomic dipoles essentially modifies their coupling with the radiation modes, offers an alternative approach to light-matter interfacing protocols. Here, we show how the cooperativity and quasi-static dipole interaction affect the process of light propagation under the conditions of electromagnetically-induced transparency (EIT). We perform comparative analysis of the self-consistent approach with ab-initio microscopic calculations and emphasize the role of the interatomic interaction in the dipoles' dynamics. Our results show that in such a dense and strongly disordered system the EIT-based light storage protocol stays relatively insensitive to configuration variations and can be obtained with essentially less atoms than it is normally needed for dilute configurations.

  18. Correlated density-dependent chiral forces for infinite matter calculations within the Green's function approach

    E-Print Network [OSTI]

    Arianna Carbone; Arnau Rios; Artur Polls

    2014-11-19T23:59:59.000Z

    The properties of symmetric nuclear and pure neutron matter are investigated within an extended self-consistent Green's function method that includes the effects of three-body forces. We use the ladder approximation for the study of infinite nuclear matter and incorporate the three-body interaction by means of a density-dependent two-body force. This force is obtained via a correlated average over the third particle, with an in-medium propagator consistent with the many-body calculation we perform. We analyze different prescriptions in the construction of the average and conclude that correlations provide small modifications at the level of the density-dependent force. Microscopic as well as bulk properties are studied, focusing on the changes introduced by the density dependent two-body force. The total energy of the system is obtained by means of a modified Galitskii-Migdal-Koltun sum rule. Our results validate previously used uncorrelated averages and extend the availability of chirally motivated forces to a larger density regime.

  19. Nuclear force in Lattice QCD

    E-Print Network [OSTI]

    T. T. Takahashi; T. Doi; H. Suganuma

    2006-01-05T23:59:59.000Z

    We perform the quenched lattice QCD analysis on the nuclear force (baryon-baryon interactions). We employ $20^3\\times 24$ lattice at $\\beta=5.7$ ($a\\simeq 0.19$ fm) with the standard gauge action and the Wilson quark action with the hopping parameters $\\kappa=0.1600, 0.1625, 0.1650$, and generate about 200 gauge configurations. We measure the temporal correlators of the two-baryon system which consists of heavy-light-light quarks. We extract the inter-baryon force as a function of the relative distance $r$. We also evaluate the contribution to the nuclear force from each ``Feynman diagram'' such as the quark-exchange diagram individually, and single out the roles of Pauli-blocking effects or quark exchanges in the inter-baryon interactions.

  20. Pulsed Power for a Dynamic Transmission Electron Microscope

    SciTech Connect (OSTI)

    dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

    2009-06-25T23:59:59.000Z

    Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

  1. Atomic Resolution Imaging and Quantification of Chemical Functionality of Surfaces

    SciTech Connect (OSTI)

    Schwarz, Udo [Yale University

    2014-12-10T23:59:59.000Z

    The work carried out from 2006-2014 under DoE support was targeted at developing new approaches to the atomic-scale characterization of surfaces that include species-selective imaging and an ability to quantify chemical surface interactions with site-specific accuracy. The newly established methods were subsequently applied to gain insight into the local chemical interactions that govern the catalytic properties of model catalysts of interest to DoE. The foundation of our work was the development of three-dimensional atomic force microscopy (3D-AFM), a new measurement mode that allows the mapping of the complete surface force and energy fields with picometer resolution in space (x, y, and z) and piconewton/millielectron volts in force/energy. From this experimental platform, we further expanded by adding the simultaneous recording of tunneling current (3D-AFM/STM) using chemically well-defined tips. Through comparison with simulations, we were able to achieve precise quantification and assignment of local chemical interactions to exact positions within the lattice. During the course of the project, the novel techniques were applied to surface-oxidized copper, titanium dioxide, and silicon oxide. On these materials, defect-induced changes to the chemical surface reactivity and electronic charge density were characterized with site-specific accuracy.

  2. Forcing in Strategic Belief Models

    E-Print Network [OSTI]

    Tohmè, Fernando; Gangle, Rocco

    2012-01-01T23:59:59.000Z

    Forcing is a methodology for building models of Set Theory satisfying certain properties. Since its inception by Paul Cohen, in the early 1960s, it has been applied to several areas in Mathematical Logic, becoming a powerful tool in the analysis of axiomatic systems. In this paper we extend the applicability of forcing to game-theoretic strategic belief models. In particular, we propose a very general notion of solutions for such games by enlarging Brandenburger's $RmAR$ condition via extension through generic types.

  3. Automatic HTS force measurement instrument

    DOE Patents [OSTI]

    Sanders, Scott T. (Valparaiso, IN); Niemann, Ralph C. (Downers Grove, IL)

    1999-01-01T23:59:59.000Z

    A device for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed.

  4. Automatic HTS force measurement instrument

    DOE Patents [OSTI]

    Sanders, S.T.; Niemann, R.C.

    1999-03-30T23:59:59.000Z

    A device is disclosed for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed. 3 figs.

  5. Atomization and Sprays 20(4), 297310 (2010) SPLASHING PHENOMENA DURING LIQUID

    E-Print Network [OSTI]

    Aguilar, Guillermo

    sound speed in liquid, m/s Tsat saturation temperature of droplet at 1 atm, C F force, N V droplet number (V µ/) tc characteristic spreading time, s Cg sound speed in ambient gas, m/s T temperature, C ClAtomization and Sprays 20(4), 297­310 (2010) SPLASHING PHENOMENA DURING LIQUID DROPLET IMPACT Jie

  6. Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux

    E-Print Network [OSTI]

    Rioux, Frank

    Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux Some quantum textbooks invoke with involves the middle term in the Hamiltonian given above. Some authors call it the centrifugal potential the effective potential energy. In support of this maneuver they invoke the idea of centrifugal force, which

  7. Measuring biomolecules: an image processing and length estimation pipeline using atomic

    E-Print Network [OSTI]

    Mohri, Mehryar

    Measuring biomolecules: an image processing and length estimation pipeline using atomic force, these snapshots would give direct, specific observation of the cell's regulation behavior. Taking a snapshot estimation pipeline using AFM that can achieve these measurement tolerances. In particular, we developed

  8. Solvent-induced forces in protein folding

    SciTech Connect (OSTI)

    Ben-Naim, A. (Hebrew Univ., Jerusalem (Israel))

    1990-08-23T23:59:59.000Z

    The solvent-induced forces between various groups on the protein are examined. It is found that the intramolecular hydrophilic forces are likely to be the strongest forces mediated through the solvent. It is argued that these are probably the most important solvent-induced driving forces in the process of protein folding.

  9. October 9, 2014- SEAB Task Force Meeting

    Broader source: Energy.gov [DOE]

    SECRETARY OF ENERGY ADVISORY BOARDTask Force Meeting on Technology Development for Environmental Management (EM)

  10. Nanoscale Optical Devices: Force, Torque and Modulator

    E-Print Network [OSTI]

    Liu, Ming

    2010-01-01T23:59:59.000Z

    enhancements produced by a bowtie (Butterworth Heinemann,stronger binding forces. For bowtie structures, the field

  11. Detection of transient fluorine atoms

    SciTech Connect (OSTI)

    Loge, G.W.; Nereson, N.; Fry, H.A.

    1986-01-01T23:59:59.000Z

    A KrF eximer laser with a fluence of 50 mJ/cm/sup 2/ was used to photolyze either uranium hexafluoride or molecular fluorine, yielding a transient number density of fluorine atoms. The rise and decay of the atomic fluorine density was observed by transient absorption of a 25-..mu..m Pb-salt diode laser. To prevent the diode laser wavelength from drifting out of resonance with the atomic fluorine line, part of the beam was split off and sent through a microwave discharge fluorine atom cell. This allowed a wavelength modulation-feedback technique to be used to lock the diode laser wavelength onto the atomic line. The remaining diode laser beam was made collinear with the eximer laser beam using a LiF window with a 45/sup 0/ angle of incidence to reflect the infrared beam while transmitting most of the uv beam. Using this setup along with a transient digitizer to average between 100 and 200 transient absorption profiles, fluorine atom number densities on the order of 10/sup 14/ cm/sup -3/ in a 1.7 m pathlength were detected. The signals observed were about a factor of two less than expected from known photolysis and atomic fluorine absorption cross-sections. 2 refs., 4 figs.

  12. Anticipating the atom: popular perceptions of atomic power before Hiroshima

    E-Print Network [OSTI]

    d'Emal, Jacques-Andre Christian

    1994-01-01T23:59:59.000Z

    Before Hiroshima made the Bomb an object of popular concern, possible implications and applications of atomic physics had been discussed in the public forum. The new science of X-rays and radium promised the possibilities of unlimited energy...

  13. atomization atomic absorption: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in vacuum. The...

  14. Constraints on New Gravitylike Forces in the Nanometer Range

    E-Print Network [OSTI]

    Kamiya, Y; Tani, M; Kim, G N; Komamiya, S

    2015-01-01T23:59:59.000Z

    We report on a new constraint on gravitylike short-range forces, in which the interaction charge is mass, obtained by measuring the angular distribution of 5 A neutrons scattering off atomic xenon gas. Around 10^7 scattering events were collected at the 40 m small angle neutron scattering beam line located at the HANARO research reactor of the Korean Atomic Energy Research Institute. The extracted coupling strengths of new forces in the Yukawa-type parametrization are g^2 = (0.2 \\pm 6.8 \\pm 2.0) \\times 10^-15 GeV^2 and g^2 = (-5.3 \\pm 9.0 + 2.7 -2.8) \\times 10^-17 GeV^2 for interaction ranges of 0.1 and 1.0 nm, respectively. These strengths correspond to 95% confidence level limits of g^2 < (1.4 \\pm 0.2) \\times 10^-14 GeV^-2 and g^2 < (1.3 \\pm 0.2) \\times 10^-16 GeV^-2, improving the current limits for interaction ranges between 4 and 0.04 nm by a factor of up to 10.

  15. Casimir Friction Force and Energy Dissipation for Moving Harmonic Oscillators

    E-Print Network [OSTI]

    Johan S. Høye; Iver Brevik

    2010-09-15T23:59:59.000Z

    The Casimir friction problem for a pair of dielectric particles in relative motion is analyzed, utilizing a microscopic model in which we start from statistical mechanics for harmonically oscillating particles at finite temperature moving nonrelativistically with constant velocity. The use of statistical mechanics in this context has in our opinion some definite advantages, in comparison with the more conventional quantum electrodynamic description of media that involves the use of a refractive index. The statistical-mechanical description is physical and direct, and the oscillator model, in spite of its simplicity, is nevertheless able to elucidate the essentials of the Casimir friction. As is known, there are diverging opinions about this kind of friction in the literature. Our treatment elaborates upon, and extends, an earlier theory presented by us back in 1992. There we found a finite friction force at any finite temperature, whereas at zero temperature the model led to a zero force. As an additional development in the present paper we evaluate the energy dissipation making use of an exponential cutoff truncating the relative motion of the oscillators. For the dissipation we also establish a general expression that is not limited to the simple oscillator model.

  16. Chemical factors influencing selenium atomization

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  17. Chemical factors influencing selenium atomization 

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  18. LABORATORY I FORCES AND EQUILIBRIUM

    E-Print Network [OSTI]

    Minnesota, University of

    of equilibrium is the result of a balance among all of the different forces interacting with the object (sections 1-10), chapter 4 (sections 1, 2, 5- 7), the paragraph at equation 6-13, chapter 10 (sections 5 problems before your lecturer addresses this material. So, it is very important that you read the text

  19. Heterogeneous Catalysis on Atomically Dispersed Supported Metals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction on Multifunctional Pd Catalysts. Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction...

  20. Growth mode evolution of hafnium oxide by atomic layer deposition

    SciTech Connect (OSTI)

    Nie, Xianglong; Ma, Fei; Ma, Dayan, E-mail: madayan@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi (China); Xu, Kewei [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China and Department of Physics and Opt-electronic Engineering, Xi'an University of Arts and Science, Xi'an 710065, Shaanxi (China)

    2014-01-15T23:59:59.000Z

    HfO{sub 2} thin films were deposited using tetrakis-ethylmethylamido hafnium and H{sub 2}O as precursors on silicon by atomic layer deposition (ALD). The morphology and microstructures at different ALD cycles were characterized by atomic force microscopy and high-resolution transmission electron microscopy. Based on the height–height correlation function and power spectral density function, quantitative analysis of surface morphologies was performed. Three characteristic dimensions (?{sub 1}, ?{sub 2}, and ?{sub 3}) corresponding to three surface structures, islands, local and global fluctuations, were identified. The evolution of ALD growth mode at range of the three critical scales was investigated, respectively. It suggests the transformation of growth mode from quasi two-dimensional layer-by-layer to three-dimensional island for global fluctuations.

  1. Selective Atomic Heating in Plasmas: Implications for Quantum Theory

    E-Print Network [OSTI]

    Phillips, Jonathan

    2008-01-01T23:59:59.000Z

    A new model of quantum mechanics, Classical Quantum Mechanics, is based on the (nearly heretical) postulate that electrons are physical objects that obey classical physical laws. Indeed, ionization energies, excitation energies etc. are computed based on picturing electrons as bubbles of charge that symmetrically surround a nucleus. Hence, for example, simple algebraic expressions based on Newtonian force balances are used to predict ionization energies and stable excitation states with remarkable precision. One of the most startling predictions of the model is that there are stable sizes of the hydrogen atom electron (bubble diameter) that are smaller (called hydrinos) than that calculated for the standard ground state. Experimental evidence in support of this novel physical/classical version of quantum is alleged to be found in the existence of super heated hydrogen atoms reported by many teams in a variety of plasmas. It is postulated that the energy required for creating super heated H aoms comes from the...

  2. Imaging atoms in 3-D

    ScienceCinema (OSTI)

    Ercius, Peter

    2014-06-27T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  3. Imaging atoms in 3-D

    SciTech Connect (OSTI)

    Ercius, Peter

    2013-10-31T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  4. Scanning optical microscope with long working distance objective

    DOE Patents [OSTI]

    Cloutier, Sylvain G. (Newark, DE)

    2010-10-19T23:59:59.000Z

    A scanning optical microscope, including: a light source to generate a beam of probe light; collimation optics to substantially collimate the probe beam; a probe-result beamsplitter; a long working-distance, infinity-corrected objective; scanning means to scan a beam spot of the focused probe beam on or within a sample; relay optics; and a detector. The collimation optics are disposed in the probe beam. The probe-result beamsplitter is arranged in the optical paths of the probe beam and the resultant light from the sample. The beamsplitter reflects the probe beam into the objective and transmits resultant light. The long working-distance, infinity-corrected objective is also arranged in the optical paths of the probe beam and the resultant light. It focuses the reflected probe beam onto the sample, and collects and substantially collimates the resultant light. The relay optics are arranged to relay the transmitted resultant light from the beamsplitter to the detector.

  5. Fully microscopic shell-model calculations with realistic effective hamiltonians

    E-Print Network [OSTI]

    L. Coraggio; A. Covello; A. Gargano; N. Itaco; T. T. S. Kuo

    2011-01-24T23:59:59.000Z

    The advent of nucleon-nucleon potentials derived from chiral perturbation theory, as well as the so-called V-low-k approach to the renormalization of the strong short-range repulsion contained in the potentials, have brought renewed interest in realistic shell-model calculations. Here we focus on calculations where a fully microscopic approach is adopted. No phenomenological input is needed in these calculations, because single-particle energies, matrix elements of the two-body interaction, and matrix elements of the electromagnetic multipole operators are derived theoretically. This has been done within the framework of the time-dependent degenerate linked-diagram perturbation theory. We present results for some nuclei in different mass regions. These evidence the ability of realistic effective hamiltonians to provide an accurate description of nuclear structure properties.

  6. Analytical scanning evanescent microwave microscope and control stage

    DOE Patents [OSTI]

    Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

    2013-01-22T23:59:59.000Z

    A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

  7. Pion-nucleus reactions in a microscopic transport model

    E-Print Network [OSTI]

    A. Engel; W. Cassing; U. Mosel; M. Schäfer; Gy. Wolf

    1993-07-07T23:59:59.000Z

    We analyse pion-nucleus reactions in a microscopic transport model of the BUU type, which propagates nucleons, pions, deltas and N(1440)-resonances explicitly in space and time. In particular we examine pion absorption and inelastic scattering cross sections for pion kinetic energies T(pi) =85-315MeV and various target masses. In general, the mass-dependence of the experimental data is well described for energies up to the delta-resonance (\\approx 160 MeV) while the absorption cross sections are somewhat overestimated for the higher energies. In addition we study the possible dynamical effects of delta- and pion-potentials in the medium on various observables as well as alternative models for the in-medium delta-width.

  8. Analytical scanning evanescent microwave microscope and control stage

    DOE Patents [OSTI]

    Xiang, Xiao-Dong (Danville, CA); Gao, Chen (Anhui, CN); Duewer, Fred (Albany, CA); Yang, Hai Tao (Albany, CA); Lu, Yalin (Chelmsford, MA)

    2009-06-23T23:59:59.000Z

    A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

  9. Microscopic return point memory in Co/Pd multilayer films

    SciTech Connect (OSTI)

    Seu, K.A.; Su, R.; Roy, S.; Parks, D.; Shipton, E.; Fullerton, E.E.; Kevan, S.D.

    2009-10-01T23:59:59.000Z

    We report soft x-ray speckle metrology measurements of microscopic return point and complementary point memory in Co/Pd magnetic films having perpendicular anisotropy. We observe that the domains assemble into a common labyrinth phase with a period that varies by nearly a factor of two between initial reversal and fields near saturation. Unlike previous studies of similar systems, the ability of the film to reproduce its domain structure after magnetic cycling through saturation varies from loop to loop, from position to position on the sample, and with the part of the speckle pattern used in the metrology measurements. We report the distribution of memory as a function of field and discuss these results in terms of the reversal process.

  10. Level densities of nickel isotopes: microscopic theory versus experiment

    E-Print Network [OSTI]

    M. Bonett-Matiz; Abhishek Mukherjee; Y. Alhassid

    2013-05-01T23:59:59.000Z

    We apply a spin-projection method to calculate microscopically the level densities of a family of nickel isotopes $^{59-64}$Ni using the shell model Monte Carlo approach in the complete $pfg_{9/2}$ shell. Accurate ground-state energies of the odd-mass nickel isotopes, required for the determination of excitation energies, are determined using the Green's function method recently introduced to circumvent the odd particle-number sign problem. Our results are in excellent agreement with recent measurements based on proton evaporation spectra and with level counting data at low excitation energies. We also compare our results with neutron resonance data, assuming equilibration of parity and a spin-cutoff model for the spin distribution at the neutron binding energy, and find good agreement with the exception of $^{63}$Ni.

  11. Fully microscopic shell-model calculations with realistic effective hamiltonians

    E-Print Network [OSTI]

    Coraggio, L; Gargano, A; Itaco, N; Kuo, T T S

    2011-01-01T23:59:59.000Z

    The advent of nucleon-nucleon potentials derived from chiral perturbation theory, as well as the so-called V-low-k approach to the renormalization of the strong short-range repulsion contained in the potentials, have brought renewed interest in realistic shell-model calculations. Here we focus on calculations where a fully microscopic approach is adopted. No phenomenological input is needed in these calculations, because single-particle energies, matrix elements of the two-body interaction, and matrix elements of the electromagnetic multipole operators are derived theoretically. This has been done within the framework of the time-dependent degenerate linked-diagram perturbation theory. We present results for some nuclei in different mass regions. These evidence the ability of realistic effective hamiltonians to provide an accurate description of nuclear structure properties.

  12. Microscopic structure of electrowetting-driven transitions on superhydrophobic surfaces

    E-Print Network [OSTI]

    Staicu, A; Mugele, F

    2008-01-01T23:59:59.000Z

    We investigate directly at the microscale the morphology of the electrowetting induced transition between the Cassie-Baxter and Wenzel states for a water droplet on a superhydrophobic surface. Our experiments demonstrate that the transition originates in a very narrow annular region near the macroscopic contact line, which is first invaded by water and causes a thin film of air to be entrapped below. At high applied voltages, a growing fraction of microscopic air-pockets collapse, resulting in a partialWenzel state. Modulations in the intensity of the light reflected from individual micro-menisci clarify that the local contact angles near the filling transition are close to the usual advancing values for contact lines on smooth surfaces.

  13. Moøller polarimetry with polarized atomic hydrogen at MESA

    SciTech Connect (OSTI)

    Bartolomé, P. Aguar; Aulenbacher, K.; Tyukin, V. [Institut für Kernphysik, Johannes Gutenberg-University, D-55099 Mainz (Germany)

    2013-11-07T23:59:59.000Z

    A new generation of parity violation (PV) electron scattering experiments are planned to be carried out at the Institut für Kernphysik in Mainz. These experiments will be performed at low energies of 100-200 MeV using the new accelerator MESA (Mainz Energy recovering Superconducting Accelerator). One of the main challenges of such experiments is to achieve an accuracy in beam polarization measurements that must be below 0.5%. This very high accuracy can be reached using polarized atomic hydrogen gas, stored in an ultra-cold magnetic trap, as the target for electron beam polarimetry based on Mo/ller scattering. Electron spin-polarized atomic hydrogen can be stored at high densities of 10{sup 16} cm{sup ?2}, over relatively long time periods, in a high magnetic field (8T) and at low temperatures (0.3K). The gradient force splits the ground state of the hydrogen into four states with different energies. Atoms in the low energy states are trapped in the strong magnetic field region whereas the high energy states are repelled and pumped away. The physics of ultra-cold atomic hydrogen in magnetic traps and the status of the Mainz Hydro-Mo/ller project will be presented.

  14. Vibration atomic layer deposition for conformal nanoparticle coating

    SciTech Connect (OSTI)

    Park, Suk Won; Woo Kim, Jun; Jong Choi, Hyung; Hyung Shim, Joon, E-mail: shimm@korea.ac.kr [School of Mechanical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2014-01-15T23:59:59.000Z

    A vibration atomic layer deposition reactor was developed for fabricating a conformal thin-film coating on nanosize particles. In this study, atomic layer deposition of 10–15-nm-thick Al{sub 2}O{sub 3} films was conducted on a high-surface-area acetylene black powder with particle diameters of 200–250?nm. Intense vibration during the deposition resulted in the effective separation of particles, overcoming the interparticle agglomeration force and enabling effective diffusion of the precursor into the powder chunk; this phenomenon led to the formation of a conformal film coating on the nanopowder particles. It was also confirmed that the atomic layer deposition Al{sub 2}O{sub 3} films initially grew on the high-surface-area acetylene black powder particles as discrete islands, presumably because chemisorption of the precursor and water occurred only on a few sites on the high-surface-area acetylene black powder surface. Relatively sluggish growth of the films during the initial atomic layer deposition cycles was identified from composition analysis.

  15. Recent Progress in ultracold atoms

    E-Print Network [OSTI]

    Baltisberger, Jay H.

    , cold gas experiments 2. How to make a BEC out of fermions 3. Recent Progress: Controlling Interaction (Feshbach Resonance) 4. From BCS to BEC: Rotating trap and spin- polarized condensates. 5. Future research and Einstein What is Bose-Einstein condensation (BEC)? #12;300 K to 1 mK 109 atoms 1 mK to 1 mK 108 106 atoms

  16. Absorption properties of identical atoms

    E-Print Network [OSTI]

    Pedro Sancho

    2013-07-31T23:59:59.000Z

    Emission rates and other optical properties of multiparticle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas.

  17. Optomechanical Rydberg-atom excitation via dynamic Casimir-Polder coupling

    E-Print Network [OSTI]

    Mauro Antezza; Caterina Braggio; Giovanni Carugno; Antonio Noto; Roberto Passante; Lucia Rizzuto; Giuseppe Ruoso; Salvatore Spagnolo

    2014-07-09T23:59:59.000Z

    We study the optomechanical coupling of a oscillating effective mirror with a Rydberg atomic gas, mediated by the dynamical atom-mirror Casimir-Polder force. This coupling may produce a near-field resonant atomic excitation whose probability scales as $\\propto (d^2\\;a\\;n^4\\;t)^2/z_0^8$, where $z_0$ is the average atom-surface distance, $d$ the atomic dipole moment, $a$ the mirror's effective oscillation amplitude, $n$ the initial principal quantum number, and $t$ the time. We propose an experimental configuration to realize this system with a cold atom gas trapped at a distance $\\sim 2\\cdot10 \\, \\mu$m from a semiconductor substrate, whose dielectric constant is periodically driven by an external laser pulse, hence realizing en effective mechanical mirror motion due to the periodic change of the substrate from transparent to reflecting. For a parabolic gas shape, this effect is predicted to excite about $\\sim 10^2$ atoms of a dilute gas of $10^3$ trapped Rydberg atoms with $n=75$ after about $0.5 \\,\\mu \\mbox{s}$, hence high enough to be detected in typical Rydberg gas experimental conditions.

  18. Commissioning an EUV mask microscope for lithography generations reaching 8 nm

    E-Print Network [OSTI]

    Goldberg, Kenneth A.

    2014-01-01T23:59:59.000Z

    Commissioning an EUV mask microscope for lithographycurrent status of the tool commissioning and the performance1. INTRODUCTION We are now commissioning a new, synchrotron—

  19. Remote control of a scanning electron microscope aperture and gun alignment

    DOE Patents [OSTI]

    Cramer, Charles E.; Campchero, Robert J.

    2003-10-07T23:59:59.000Z

    This invention relates to a remote control system which through gear motors coupled to the scanning electron microscope (SEM) manual control knobs readily permits remote adjustments as necessary.

  20. HIGH RESOLUTION SCANNING AUGER MICROSCOPIC INVESTIGATION OF INTERGRANULAR FRACTURE IN AS-QUENCHED Fe-12Mn

    E-Print Network [OSTI]

    Lee, H.J.

    2013-01-01T23:59:59.000Z

    contents in Fe-Mn alloys. Scanning electron fractographsTransactions HIGH RESOLUTION SCANNING AUGER MICROSCOPICof Califomia. HIGH RESOLUTION SCANNING AUGER MICROSCOPIC

  1. The Engineering of Optical Conservative Force

    E-Print Network [OSTI]

    Du, Junjie; Ding, Kun; Du, Guiqiang; Lin, Zhifang; Chan, C T; Ng, Jack

    2015-01-01T23:59:59.000Z

    Optical forces have been fruitfully applied in a broad variety of areas that not only span the traditional scientific fields such as physics, chemistry, and biology, but also in more applied fields. It is customary and useful to split the optical force into the (conservative) gradient force and the (non-conservative) scattering and absorption force. These forces are different in attributes. The ability to tailor them will open great potential in fundamental optics and practical applications. Here, we present an analytical and a numerical approach to calculate these forces, and, with these tools, we create a fairly general class of 2D conservative optical force field. In general, particles immersed in an optical force do not obey equilibrium statistical mechanics, making the analysis complicated. With conservative forces, these issues are resolved.

  2. Microwave probes Dipole Blockade and van der Waals Forces in a Cold Rydberg Gas

    E-Print Network [OSTI]

    R. Celistrino Teixeira; C. Hermann-Avigliano; Thanh Long Nguyen; T. Cantat-Moltrecht; Jean-Michel Raimond; S. Haroche; S. Gleyzes; M. Brune

    2015-02-14T23:59:59.000Z

    We show that microwave spectroscopy of a dense Rydberg gas trapped on a superconducting atom chip in the dipole blockade regime reveals directly the dipole-dipole many-body interaction energy spectrum. We use this method to investigate the expansion of the Rydberg cloud under the effect of repulsive van der Waals forces and the breakdown of the frozen gas approximation. This study opens a promising route for quantum simulation of many-body systems and quantum information transport in chains of strongly interacting Rydberg atoms.

  3. Microwave probes Dipole Blockade and van der Waals Forces in a Cold Rydberg Gas

    E-Print Network [OSTI]

    Teixeira, R Celistrino; Nguyen, Thanh Long; Cantat-Moltrecht, T; Raimond, Jean-Michel; Haroche, S; Gleyzes, S; Brune, M

    2015-01-01T23:59:59.000Z

    We show that microwave spectroscopy of a dense Rydberg gas trapped on a superconducting atom chip in the dipole blockade regime reveals directly the dipole-dipole many-body interaction energy spectrum. We use this method to investigate the expansion of the Rydberg cloud under the effect of repulsive van der Waals forces and the breakdown of the frozen gas approximation. This study opens a promising route for quantum simulation of many-body systems and quantum information transport in chains of strongly interacting Rydberg atoms.

  4. Centrifugal force in Kerr geometry

    E-Print Network [OSTI]

    Sai Iyer; A R Prasanna

    1992-07-31T23:59:59.000Z

    We have obtained the correct expression for the centrifugal force acting on a particle at the equatorial circumference of a rotating body in the locally non-rotating frame of the Kerr geometry. Using this expression for the equilibrium of an element on the surface of a slowly rotating Maclaurin spheroid, we obtain the expression for the ellipticity (as discussed earlier by Abramowicz and Miller) and determine the radius at which the ellipticity is maximum.

  5. Hydrodynamic forces on piggyback pipelines

    SciTech Connect (OSTI)

    Jakobsen, M.L.; Sayer, P. [Univ. of Strathclyde, Glasgow (United Kingdom)

    1995-12-31T23:59:59.000Z

    An increasing number of new offshore pipelines have been designed as bundles, mainly because of overall cost reductions. One popular way of combining two pipelines with different diameters is the piggyback configuration, with the smaller pipeline strapped on top of the main pipeline. The external hydrodynamic forces on this combination are at present very roughly estimated; pipeline engineers need more data to support their designs. This paper presents experimental results for the in-line hydrodynamic loading on three different piggyback set-ups. The models comprised a 0.4 m main pipeline, and three piggyback pipelines with diameters of 0.038 m, 0.059 m and 0.099 m. Each small pipeline was separately mounted to the main pipeline, with a gap equal to its own diameter. These model sizes lie approximately between half- and full-scale. Experiments were undertaken for K{sub C} between 5 and 42, and R{sub e} in the range 0.0 * 10{sup 4} to 8.5 * 10{sup 5}. The results based on Morison`s equation indicate that a simple addition of the separate forces acting on each cylinder underestimates the actual force by up to 35% at low K{sub C} (< {approximately} 10) and by as much as 100% in the drag-dominated regime (K{sub C} > {approximately} 20).

  6. Friction forces in cosmological models

    E-Print Network [OSTI]

    Donato Bini; Andrea Geralico; Daniele Gregoris; Sauro Succi

    2014-08-23T23:59:59.000Z

    We investigate the dynamics of test particles undergoing friction forces in a Friedmann-Robertson-Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting-Robertson-like friction force in the equations of motion, leading to measurable (at least in principle) deviations of the particle trajectories from geodesic motion. The effect on the peculiar velocities of the particles is investigated for various equations of state of the background fluid and different standard cosmological models. The friction force is found to have major effects on particle motion in closed FRW universes, where it turns the time-asymptotic value (approaching the recollapse) of the peculiar particle velocity from ultra-relativistic (close to light speed) to a co-moving one, i.e., zero peculiar speed. On the other hand, for open or flat universes the effect of the friction is not so significant, because the time-asymptotic peculiar particle speed is largely non-relativistic also in the geodesic case.

  7. Accelerometer using atomic waves for space applications

    E-Print Network [OSTI]

    of Bose-Einstein condensation (BEC) of a dilute gas of trapped atoms in a single quantum state [18, 19, 20 of such devices in the field of navigation, surveying and analysis of earth structures. Matter-wave interferometry that the use of Bose-Einstein condensed atoms will bring the science of atom optics, and in particular atom

  8. Detection of secondary phases in duplex stainless steel by magnetic force microscopy and scanning Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Ramírez-Salgado, J. [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Domínguez-Aguilar, M.A., E-mail: madoming@imp.mx [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Castro-Domínguez, B. [University of Tokyo, Department of Chemical System Engineering, Faculty of Engineering Bldg. 5, 7F 722, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–8656 (Japan); Hernández-Hernández, P. [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Newman, R.C. [University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto M5S 3E5 (Canada)

    2013-12-15T23:59:59.000Z

    The secondary phase transformations in a commercial super duplex stainless steel were investigated by micro-chemical analyses and high resolution scanning probe microscopy. Energy dispersive X-ray and electron probe detected ferrite and austenite as well as secondary phases in unetched aged duplex stainless steel type 25Cr-7Ni-3Mo. Volta potential indicated that nitride and sigma appeared more active than ferrite, while secondary austenite and austenite presented a nobler potential. Reversal order in nobility is thought to be attributable to the potential ranking provided by oxide nature diversity as a result of secondary phase surface compositions on steel. After eutectoid transformation, secondary austenite was detected by electron probe microanalysis, whereas atomic force microscopy distinguished this phase from former austenite by image contrast. Magnetic force microscopy revealed a “ghosted” effect on the latter microstructure probably derived from metal memory reminiscence of mechanical polishing at passivity and long range magnetic forces of ferrite phase. - Highlights: • Nobility detection of secondary phases by SKPFM in DSS particles is not a straightforward procedure. • As Volta potential and contrast are not always consistent SKPFM surface oxides is thought played an important role in detection. • AFM distinguished secondary austenite from former austenite by image contrast though SEM required EPMA.

  9. On Dynamic Models of Robot Force Control

    E-Print Network [OSTI]

    Eppinger, Steven D.

    1986-07-01T23:59:59.000Z

    For precise robot control, endpoint compliance strategies utilize feedback from a force sensor located near the tool/workpiece interface. Such endpoint force control systems have been observed in the laboratory to be ...

  10. Handheld force-controlled ultrasound probe

    E-Print Network [OSTI]

    Gilbertson, Matthew Wright

    2010-01-01T23:59:59.000Z

    An hand-held force controlled ultrasound probe has been developed. The controller maintains a prescribed contact force between the probe and a patient's body. The device will enhance the diagnostic capability of free-hand ...

  11. Atomic Cascade in Muonic and Hadronic Hydrogen Atoms

    E-Print Network [OSTI]

    T. S. Jensen; V. P. Popov; V. N. Pomerantsev

    2007-12-18T23:59:59.000Z

    The atomic cascade in $\\mu^- p$ and $\\pi^- p$ atoms has been studied with the improved version of the extended cascade model in which new quantum mechanical calculations of the differential and integral cross sections of the elastic scattering, Stark transitions and Coulomb de-excitation have been included for the principal quantum number values $n\\le 8$ and the relative energies $E \\ge 0.01$ eV. The $X$-ray yields and kinetic energy distributions are compared with the experimental data.

  12. Quantum Electrodynamics of Atomic Resonances

    E-Print Network [OSTI]

    Miguel Ballesteros; Jérémy Faupin; Jürg Fröhlich; Baptiste Schubnel

    2015-03-09T23:59:59.000Z

    A simple model of an atom interacting with the quantized electromagnetic field is studied. The atom has a finite mass $m$, finitely many excited states and an electric dipole moment, $\\vec{d}_0 = -\\lambda_{0} \\vec{d}$, where $\\| d^{i}\\| = 1,$ $ i=1,2,3,$ and $\\lambda_0$ is proportional to the elementary electric charge. The interaction of the atom with the radiation field is described with the help of the Ritz Hamiltonian, $-\\vec{d}_0\\cdot \\vec{E}$, where $\\vec{E}$ is the electric field, cut off at large frequencies. A mathematical study of the Lamb shift, the decay channels and the life times of the excited states of the atom is presented. It is rigorously proven that these quantities are analytic functions of the momentum $\\vec{p}$ of the atom and of the coupling constant $\\lambda_0$, provided $|\\vec{p}| < mc$ and $| \\Im\\vec{p} |$ and $| \\lambda_{0} |$ are sufficiently small. The proof relies on a somewhat novel inductive construction involving a sequence of `smooth Feshbach-Schur maps' applied to a complex dilatation of the original Hamiltonian, which yields an algorithm for the calculation of resonance energies that converges super-exponentially fast.

  13. Nuclear Radiological Threat Task Force Established | National...

    National Nuclear Security Administration (NNSA)

    Radiological Threat Task Force Established | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

  14. Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective

    E-Print Network [OSTI]

    Zare, Richard N.

    Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective Bo Huang-5080 We designed, constructed, and tested a surface plasmon resonance (SPR) microscope using a high, combined with various methods to shorten the surface plasmon propaga- tion length, achieves diffraction

  15. Description and performance of a highly versatile, low-cost fiber-optic confocal Raman microscope

    E-Print Network [OSTI]

    Myrick, Michael Lenn

    Description and performance of a highly versatile, low-cost fiber-optic confocal Raman microscope C for publication 29 September 1995 A versatile fiber-optic confocal Raman microscope has been developed. Fiber and disadvantages.11,12 We report here the development of an automated highly versatile fiber-optic confocal Raman

  16. An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large scale imaging

    E-Print Network [OSTI]

    Pohl, Karsten

    An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large describe the design and performance of a fast-scanning, variable temperature scanning tunneling microscope of the scanner tube. The total scanning area is about 8 8 m2 . The sample temperature can be adjusted by a few

  17. Integrated micro-scanning tunneling microscope Y. Xu and N. C. MacDonald

    E-Print Network [OSTI]

    MacDonald, Noel C.

    Integrated micro-scanning tunneling microscope Y. Xu and N. C. MacDonald School of Electrical of micro-scanning tunneling microscopes micro-STMs have been fabricated. The integrated micro metal conductor on a silicon chip. © 1995 American Institute of Physics. Scanned-probe instruments have

  18. Microfabricated rubber microscope using soft solid immersion lenses Yann Gambin, Olivier Legrand, and Stephen R. Quakea

    E-Print Network [OSTI]

    Quake, Stephen R.

    Microfabricated rubber microscope using soft solid immersion lenses Yann Gambin, Olivier Legrand a technique of soft lithography to microfabricate efficient solid immersion lenses SIL out of rubber into a handheld rubber microscope for microfluidic flow cytometry and imaged single E. Coli cells by fluorescence

  19. Microscopic theory of protein folding rates. II. Local reaction coordinates and chain dynamics

    E-Print Network [OSTI]

    Takada, Shoji

    Microscopic theory of protein folding rates. II. Local reaction coordinates and chain dynamics John involved in barrier crossing for protein folding are investigated in terms of the chain dynamics of the polymer backbone, completing the microscopic description of protein folding presented in the preceding

  20. Oblique-incidence reflectivity difference microscope for label-free high-throughput detection of biochemical

    E-Print Network [OSTI]

    Zhu, Xiangdong

    Oblique-incidence reflectivity difference microscope for label-free high-throughput detection (OI-RD) microscope, a form of polarization-modulated imaging ellipsometer, for label on the polarizer­ compensator­sample­analyzer scheme and under the off-null condition, a polarization-modulated OI

  1. MATERIALS WITH COMPLEX ELECTRONIC/ATOMIC STRUCTURES

    SciTech Connect (OSTI)

    D. M. PARKIN; L. CHEN; ET AL

    2000-09-01T23:59:59.000Z

    We explored both experimentally and theoretically the behavior of materials at stresses close to their theoretical strength. This involves the preparation of ultra fine scale structures by a variety of fabrication methods. In the past year work has concentrated on wire drawing of in situ composites such as Cu-Ag and Cu-Nb. Materials were also fabricated by melting alloys in glass and drawing them into filaments at high temperatures by a method known as Taylor wire technique. Cu-Ag microwires have been drawn by this technique to produce wires 10 {micro}m in diameter that consist of nanoscale grains of supersaturated solid solution. Organogels formed from novel organic gelators containing cholesterol tethered to squaraine dyes or trans-stilbene derivatives have been studied from several different perspectives. The two types of molecules are active toward several organic liquids, gelling in some cases at w/w percentages as low as 0.1. While relatively robust, acroscopically dry gels are formed in several cases, studies with a variety of probes indicate that much of the solvent may exist in domains that are essentially liquid-like in terms of their microenvironment. The gels have been imaged by atomic force microscopy and conventional and fluorescence microscopy, monitoring both the gelator fluorescence in the case of the stilbene-cholesterol gels and, the fluorescence of solutes dissolved in the solvent. Remarkably, our findings show that several of the gels are composed of similarly appearing fibrous structures visible at the nano-, micro-, and macroscale.

  2. Degeneracy Breaking of Hydrogen Atom

    E-Print Network [OSTI]

    Agung Trisetyarso; Pantur Silaban

    2014-11-21T23:59:59.000Z

    The three dimensional rotation group, SO(3), is a symmetry group of the normal hydrogen atom. Each reducible representation of this group can be associated with a degenerate energy level. If this atom is placed in an external magnetic field, the interaction between the orbital magnetic moment with this field will lead to a symmetry breaking where the symmetry group of the atom is a new group distinct from the SO(3) group. This phenomenon describes the normal Zeeman effect, where a degenerate energy level splits into several new energy levels. It is explicitly shown that each of the new energy levels can be associated with an irreducible representation of the new symmetry group.

  3. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

    1997-01-01T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid.

  4. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1997-07-08T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid. 3 figs.

  5. Towards a Microscopic Reaction Description Based on Energy Density Functionals

    SciTech Connect (OSTI)

    Nobre, G A; DIetrich, F S; Escher, J E; Thompson, I J; Dupuis, M; Terasaki, J; Engel, J

    2011-09-26T23:59:59.000Z

    A microscopic calculation of reaction cross sections for nucleon-nucleus scattering has been performed by explicitly coupling the elastic channel to all particle-hole excitations in the target and one-nucleon pickup channels. The particle-hole states may be regarded as doorway states through which the flux flows to more complicated configurations, and subsequently to long-lived compound nucleus resonances. Target excitations for {sup 40,48}Ca, {sup 58}Ni, {sup 90}Zr and {sup 144}Sm were described in a random-phase framework using a Skyrme functional. Reaction cross sections obtained agree very well with experimental data and predictions of a state-of-the-art fitted optical potential. Couplings between inelastic states were found to be negligible, while the pickup channels contribute significantly. The effect of resonances from higher-order channels was assessed. Elastic angular distributions were also calculated within the same method, achieving good agreement with experimental data. For the first time observed absorptions are completely accounted for by explicit channel coupling, for incident energies between 10 and 70 MeV, with consistent angular distribution results.

  6. Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report

    SciTech Connect (OSTI)

    Ellis, P; Flom, Z; Heinselman, K; Nguyen, T; Tung, S; Haskell, R; Reed, B W; LaGrange, T

    2011-08-04T23:59:59.000Z

    The Dynamic Transmission Electron Microscope (DTEM) team at Harvey Mudd College has been sponsored by LLNL to design and build a test setup for optimizing the performance of the DTEM's electron source. Unlike a traditional TEM, the DTEM achieves much faster exposure times by using photoemission from a photocathode to produce electrons for imaging. The DTEM team's work is motivated by the need to improve the coherence and current density of the electron cloud produced by the electron gun in order to increase the image resolution and contrast achievable by DTEM. The photoemission test setup is nearly complete and the team will soon complete baseline tests of electron gun performance. The photoemission laser and high voltage power supply have been repaired; the optics path for relaying the laser to the photocathode has been finalized, assembled, and aligned; the internal setup of the vacuum chamber has been finalized and mostly implemented; and system control, synchronization, and data acquisition has been implemented in LabVIEW. Immediate future work includes determining a consistent alignment procedure to place the laser waist on the photocathode, and taking baseline performance measurements of the tantalum photocathode. Future research will examine the performance of the electron gun as a function of the photoemission laser profile, the photocathode material, and the geometry and voltages of the accelerating and focusing components in the electron gun. This report presents the team's progress and outlines the work that remains.

  7. Nanoplasmonic Lattices for Ultracold atoms

    E-Print Network [OSTI]

    M. Gullans; T. Tiecke; D. E. Chang; J. Feist; J. D. Thompson; J. I. Cirac; P. Zoller; M. D. Lukin

    2014-07-25T23:59:59.000Z

    We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.

  8. Glacial cycles and astronomical forcing

    SciTech Connect (OSTI)

    Muller, R.A. [Lawrence Berkeley Lab., CA (United States)] [Lawrence Berkeley Lab., CA (United States); MacDonald, G.J. [International Institute for Applied Systems Analysis, Laxenburg (Austria)] [International Institute for Applied Systems Analysis, Laxenburg (Austria)

    1997-07-11T23:59:59.000Z

    Narrow spectral features in ocean sediment records offer strong evidence that the cycles of glaciation were driven by astronomical forces. Two million years ago, the cycles match the 41,000-year period of Earth`s obliquity. This supports the Croll/Milankovitch theory, which attributes the cycles to variations in insolation. But for the past million years, the spectrum is dominated by a single 100,000-year feature and is a poor match to the predictions of insolation models. The spectrum can be accounted for by a theory that derives the cycles of glaciation from variations in the inclination of Earth`s orbital plane.

  9. Thermomagnetic Force in Polyatomic Gases

    E-Print Network [OSTI]

    Larchez, M. E.; Adair, Thomas W.

    1971-01-01T23:59:59.000Z

    decreases as H/P is increased above about 500 Oe/Torr. Another difference in the two effects is that the SB effect is a universal function of H/P for the entire range of values covered. This does not appear to be true in the force effect. For NO... magnetic field also causes a de- crease in the shear viscosity of oxygen. These effects in Oz were later observed in NO and were extensively studied. It was observed that the trans- port coefficients decrease in a magnetic field 8, that the effect...

  10. Photoresponse properties of large-area MoS{sub 2} atomic layer synthesized by vapor phase deposition

    SciTech Connect (OSTI)

    Luo, Siwei; Qi, Xiang, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn; Ren, Long; Hao, Guolin; Fan, Yinping; Liu, Yundan; Han, Weijia; Zang, Chen; Li, Jun; Zhong, Jianxin, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, People's Republic of China Laboratory for Quantum Engineering and Micro-Nano Energy Technology, and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan 411105 (China)

    2014-10-28T23:59:59.000Z

    Photoresponse properties of a large area MoS{sub 2} atomic layer synthesized by vapor phase deposition method without any catalyst are studied. Scanning electron microscopy, atomic force microscopy, Raman spectrum, and photoluminescence spectrum characterizations confirm that the two-dimensional microstructures of MoS{sub 2} atomic layer are of high quality. Photoelectrical results indicate that the as-prepared MoS{sub 2} devices have an excellent sensitivity and a good reproducibility as a photodetector, which is proposed to be ascribed to the potential-assisted charge separation mechanism.

  11. Investigations into Protein-Surface Interactions via Atomic Force Microscopy and Surface Plasmon Resonance

    E-Print Network [OSTI]

    Settle, Jenifer Kaye

    2012-08-31T23:59:59.000Z

    microscopy and surface plasmon resonance. Chapter one provides background information on protein surfaces interactions. Chapter 2 summarizes the techniques and surfaces utilized in the investigations in the following chapters. Chapter 3 provides background...

  12. E-Print Network 3.0 - all-atom force field Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    coordinates and velocities for all... , simulation of long-time processes(like protein folding, new phase ... Source: Southern California, University of - Collaboratory for...

  13. Effect of Roughness as Determined by Atomic Force Microscopy on the Wetting Properties of PTFE Thin

    E-Print Network [OSTI]

    Drelich, Jaroslaw W.

    Engineering College of Mines and Earth Sciences University of Utah Salt Lake City, Utah 84112 and G. YAMAUCHI decreases the spreading of a non-wetting liquid on low energy solids (1­4). Similar work with high energy ratio (r a/A (da/dA) 1), a is the apparent contact angle, a is the actual area of surface

  14. Single asperity tribochemical wear of silicon nitride studied by atomic force microscopy

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    are hard, inert, and stable at high temperatures, making them attractive for use in extreme en- vironments lubrication, which results in low fric- tion and almost no wear, has been observed on sufficiently smooth of conditions. In the AFM geometry, the tip serves as an idealized single asperity interacting with a nearly

  15. Reactivity of Ozone with Solid Potassium Iodide Investigated by Atomic Force Microscopy

    E-Print Network [OSTI]

    Brown, Matthew A.

    2008-01-01T23:59:59.000Z

    J. C. , Reactivity of ozone on solid potassium iodide.and mechanisms of aqueous ozone reactions with bromide,for Dry Deposition of Ozone to Seawater Surfaces. Journal of

  16. CREATE-IGERT Trainees (Cont.) Patrick O'Dell Atomic force microscopy to

    E-Print Network [OSTI]

    California at Davis, University of

    and plant cell wall synthesis for biofuels Tracy Zeng ­ Cell wall formation and fermentation processes Hyrum Gillespie ­ Engineering vector-borne viral citrus disease resistance Tiffany Glavan ­ Transgenic

  17. Structural Characterization of Micromechanical Properties in Asphalt Using Atomic Force Microscopy

    E-Print Network [OSTI]

    Allen, Robert Grover

    2012-02-14T23:59:59.000Z

    -nuclear aromatics and hetero-aromatic molecules (asphaltenes), viscous naphtheno-aromatic hydrocarbons (heavy oils) and heterocyclic and polar compounds (resins). The initial relative amount and arrangement of 9 asphaltenes, resins and oils are highly... between the PDM morphology and the colloidal system where the asphaltenes are stabilized by polar aromatics in a sea of naphthene aromatics and saturated compounds. This does not necessarily invalidate the model but suggests that it is possibly too...

  18. Observation of Changes in Bacterial Cell Morphology Using Tapping Mode Atomic Force Microscopy

    E-Print Network [OSTI]

    sodium salt (MOPS) buffer (as a control), and the surface topography of the cells was examined after. Topographic images, phase images, traces of surface topography, and analyses of surface roughness were the topography of the cell was altered by the different treatments. The surface roughness was quantified in terms

  19. Focused ion beam modification of atomic force microscopy tips for near-field scanning optical microscopy

    E-Print Network [OSTI]

    Krogmeier, Jeffrey R.; Dunn, Robert C.

    2001-12-01T23:59:59.000Z

    spatial resolution be- yond the classical diffraction limit.1–3 While the technique can be implemented in several configurations, the most popular utilizes a metal-coated, tapered fiber optic probe to deliver light to nanometric dimensions. Introduced... by Betzig et al. in 1991,2 these metal-coated fiber optic probes have been successfully utilized to study single molecules, thin films, and in limited cases, biological samples.1,3 For the latter, the high spring constant of the fiber optic probes has...

  20. Near-Grazing Dynamics in Tapping-Mode Atomic Force Harry Dankowicza

    E-Print Network [OSTI]

    Zhao, Xiaopeng

    bifurcations, discontinuity mappings. 1 Introduction Nanostructured materials and devices can be endowed as hydrogen storage devices. Similarly, self-assembly of ferromag- netic nanoparticles is a promising technique for producing high-density magnetic data storage devices and biomedical materials with desirable

  1. Preamplifying cantilevers for dynamic atomic force microscopy Benedikt Zeyen,1,a

    E-Print Network [OSTI]

    of periodic interactions between the probe and the substrate when the laser is aligned on the paddle for measurements on periodically poled lithium niobate ferroelectric material is presented. A comparison

  2. Parallel Atomic Force Microscopy and NMR Spectroscopy To Investigate Self-Assembled Protein-Nucleotide Aggregates

    E-Print Network [OSTI]

    Dellaire, Graham

    - tially be quite useful for a wide variety of systems, since it would allow for the linkage of mesoscale

  3. Mode-synthesizing atomic force microscopy and mode-synthesizing sensing

    SciTech Connect (OSTI)

    Passain, Ali; Thundat, Thomas George; Tetard, Laurene

    2014-07-22T23:59:59.000Z

    A method of analyzing a sample that includes applying a first set of energies at a first set of frequencies to a sample and applying, simultaneously with the applying the first set of energies, a second set of energies at a second set of frequencies, wherein the first set of energies and the second set of energies form a multi-mode coupling. The method further includes detecting an effect of the multi-mode coupling.

  4. Atomic-Scale Simulation of Colloidal Nanoparticle Forces and Kristen A. Fichthorn

    E-Print Network [OSTI]

    Bjørnstad, Ottar Nordal

    areas in dye-sensitized solar cells, where their aggregation and interfacial structure can influence cells. Nanoparticles also figure prominently in solar-cell technologies, for example as efficient light

  5. Mechanical and Electrical Properties of CdTe Tetrapods Studied by Atomic Force Microscopy

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    J.B. Li, L.W. Wang, A.P. Alivisatos, Nature 430 (2004) 190-Meisel, E.C. Scher, A.P. Alivisatos, Nature Materials 2 [16]Tanaka, K. Sivula, A.P. Alivisatos, J.M.J. Frechet, Journal

  6. Atomic Force Microscopy of Photosystem II and Its Unit Cell Clustering Quantitatively Delineate the Mesoscale

    E-Print Network [OSTI]

    Geissler, Phillip

    the Mesoscale Variability in Arabidopsis Thylakoids Bibiana Onoa1 , Anna R. Schneider2 , Matthew D. Brooks3 Quantitatively Delineate the Mesoscale Variability in Arabidopsis Thylakoids. PLoS ONE 9(7): e101470. doi:10

  7. Modeling forces in high-temperature superconductors

    SciTech Connect (OSTI)

    Turner, L. R.; Foster, M. W.

    1997-11-18T23:59:59.000Z

    We have developed a simple model that uses computed shielding currents to determine the forces acting on a high-temperature superconductor (HTS). The model has been applied to measurements of the force between HTS and permanent magnets (PM). Results show the expected hysteretic variation of force as the HTS moves first toward and then away from a permanent magnet, including the reversal of the sign of the force. Optimization of the shielding currents is carried out through a simulated annealing algorithm in a C++ program that repeatedly calls a commercial electromagnetic software code. Agreement with measured forces is encouraging.

  8. Air Force Research Laboratory Placement: Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson

    E-Print Network [OSTI]

    Alpay, S. Pamir

    Air Force Research Laboratory Placement: Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton OH Discipline(s): Materials science/engineering, chemical. Description: We are looking for a qualified candidate to join our team at the Air Force Research Laboratory

  9. Wood Fuel Task Force Response 2 | Wood Fuel Task Force Response

    E-Print Network [OSTI]

    Wood Fuel Task Force Response #12;2 | Wood Fuel Task Force Response #12;Wood Fuel Task Force Response | 3 Wood Fuel Task Force Response Scottish Government response by Minister for Environment, Michael Russell I am pleased to present on behalf of the Scottish Government our response to the Wood Fuel

  10. Exact theory and numeric results for short pulse ionization of simple model atom in one dimension

    E-Print Network [OSTI]

    Rokhlenko, Alexander

    2015-01-01T23:59:59.000Z

    Our exact theory for continuous harmonic perturbation of a one dimensional model atom by parametric variations of its potential is generalized for the cases when a) the atom is exposed to short pulses of an external harmonic electric field and b) the forcing is represented by short bursts of different shape changing the strength of the binding potential. This work is motivated not only by the wide use of laser pulses for atomic ionization, but also by our earlier study of the same model which successfully described the ionization dynamics in all orders, i.e. the multi-photon processes, though being treated by the non-relativistic Schr\\"odinger equation. In particular, it was shown that the bound atom cannot survive the excitation of its potential caused by any non-zero frequency and amplitude of the continuous harmonic forcing. Our present analysis found important laws of the atomic ionization by short pulses, in particular the efficiency of ionizing this model system and presumably real ones as well.

  11. An ultra-bright atom laser

    E-Print Network [OSTI]

    V. Bolpasi; N. K. Efremidis; M. J. Morrissey; P. Condylis; D. Sahagun; M. Baker; W. von Klitzing

    2013-11-25T23:59:59.000Z

    We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).

  12. Ab-initio friction forces on the nanoscale: A DFT study of fcc Cu(111)

    E-Print Network [OSTI]

    Michael Wolloch; Gregor Feldbauer; Peter Mohn; Josef Redinger; András Vernes

    2014-08-26T23:59:59.000Z

    While there are a number of models that tackle the problem of calculating friction forces on the atomic level, providing a completely parameter-free approach remains a challenge. Here we present a quasi-static model to obtain an approximation to the nanofrictional response of dry, wearless systems based on quantum mechanical all-electron calculations. We propose a mechanism to allow dissipative sliding, which relies on atomic relaxations. We define two different ways of calculating the mean nanofriction force, both leading to an exponential friction-versus-load behavior for all sliding directions. Since our approach does not impose any limits on lengths and directions of the sliding paths, we investigate arbitrary sliding directions for an fcc Cu(111) interface and detect two periodic paths which form the upper and lower bound of nanofriction. For long aperiodic paths the friction force convergences to a value in between these limits. For low loads we retrieve the Derjaguin generalization of Amontons-Coulomb kinetic friction law which appears to be valid all the way down to the nanoscale. We observe a non-vanishing Derjaguin-offset even for atomically flat surfaces in dry contact.

  13. Direct measurement of thermophoretic forces

    E-Print Network [OSTI]

    Laurent Helden; Ralf Eichhorn; Clemens Bechinger

    2014-12-19T23:59:59.000Z

    We study the thermophoretic motion of a micron sized single colloidal particle in front of a flat wall by evanescent light scattering. To quantify thermophoretic effects we analyse the nonequilibrium steady state (NESS) of the particle in a constant temperature gradient perpendicular to the confining walls. We propose to determine thermophoretic forces from a 'generalized potential' associated with the probability distribution of the particle position in the NESS. Experimentally we demonstrate, how this spatial probability distribution is measured and how thermophoretic forces can be extracted with 10 fN resolution. By varying temperature gradient and ambient temperature, the temperature dependence of Soret coefficient $S_T(T)$ is determined for $r = 2.5 \\mu m$ polystyrene and $r = 1.35 \\mu m$ melamine particles. The functional form of $S_T(T)$ is in good agreement with findings for smaller colloids. In addition, we measure and discuss hydrodynamic effects in the confined geometry. The theoretical and experimental technique proposed here extends thermophoresis measurements to so far inaccessible particle sizes and particle solvent combinations.

  14. Air Force Renewable Energy Programs | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Air Force Renewable Energy Programs Air Force Renewable Energy Programs Presentation covers Air Force Renewable Energy Programs and is given at the Spring 2011 Federal Utility...

  15. Protective Force Protocols for ESS Supported Performance Tests...

    Broader source: Energy.gov (indexed) [DOE]

    security force-on-force performance tests and exercises. Protective Force Protocols for ESS Supported Performance Tests and Exercises, March 12, 2007 More Documents & Publications...

  16. ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS

    E-Print Network [OSTI]

    Johnson, Robert E.

    ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS TO CONTINUUM MECHANICS Ejection of simple and complex molecules from surfaces probes the response of condensed matter to electronic excitations and has and Engineering Physics at the University of Virginia, Charlottesville. Bo Sundqvist holds the Chair in Ion

  17. Photoabsorption by Ions and Atoms

    SciTech Connect (OSTI)

    Manson, Steven T. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)

    2004-12-01T23:59:59.000Z

    Recent progress in theoretical and experimental investigations of photoabsorption by atoms and ions is presented. Specifically, examples of near-chaotic behavior in photoionization of positive ions, low-energy manifestations of nondipole effects, high-energy breakdown of the single particle picture and new phenomenology uncovered in the inner-shell photoabsorption by negative ions are discussed.

  18. Realization of a superconducting atom chip

    E-Print Network [OSTI]

    Thomas Nirrengarten; Angie Qarry; Cédric Roux; Andreas Emmert; Gilles Nogues; Michel Brune; Jean-Michel Raimond; Serge Haroche

    2006-10-09T23:59:59.000Z

    We have trapped rubidium atoms in the magnetic field produced by a superconducting atom chip operated at liquid Helium temperatures. Up to $8.2\\cdot 10^5$ atoms are held in a Ioffe-Pritchard trap at a distance of 440 $\\mu$m from the chip surface, with a temperature of 40 $\\mu$K. The trap lifetime reaches 115 s at low atomic densities. These results open the way to the exploration of atom--surface interactions and coherent atomic transport in a superconducting environment, whose properties are radically different from normal metals at room temperature.

  19. Understanding glass-forming ability through sluggish crystallization of atomically thin metallic glassy films

    SciTech Connect (OSTI)

    Sun, Y. T.; Cao, C. R.; Huang, K. Q.; Zhao, N. J.; Gu, L., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn; Zheng, D. N., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn; Wang, W. H., E-mail: l.gu@iphy.ac.cn, E-mail: dzheng@iphy.ac.cn, E-mail: whw@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-08-04T23:59:59.000Z

    The glass-forming ability (GFA) of an alloy, closely related to its ability to resist crystallization, is a crucial issue in condensed matter physics. So far, the studies on GFA are mostly statistical and empirical guides. Benefiting from the ultrahigh thermal stability of ultrathin metallic glassy film and high resolution spherical aberration-corrected transmission electron microscope, the crystallization of atomically thin ZrCu and its microalloyed ZrCuAl glasses with markedly different GFA was investigated at the atomic scale. We find the Zr diffusivity estimated from the density of nuclei is dramatically decreased by adding of Al, which is the major reason for the much better GFA of the ZrCuAl metallic glass.

  20. STE-QUEST - Test of the Universality of Free Fall Using Cold Atom Interferometry

    E-Print Network [OSTI]

    Aguilera, D; Battelier, B; Bawamia, A; Bertoldi, A; Bondarescu, R; Bongs, K; Bouyer, P; Braxmaier, C; Cacciapuoti, L; Chaloner, C; Chwalla, M; Ertmer, W; Franz, M; Gaaloul, N; Gehler, M; Gerardi, D; Gesa, L; Gürlebeck, N; Hartwig, J; Hauth, M; Hellmig, O; Herr, W; Herrmann, S; Heske, A; Hinton, A; Ireland, P; Jetzer, P; Johann, U; Krutzik, M; Kubelka, A; Lämmerzahl, C; Landragin, A; Lloro, I; Massonnet, D; Mateos, I; Milke, A; Nofrarias, M; Oswald, M; Peters, A; Posso-Trujillo, K; Rasel, E; Rocco, E; Roura, A; Rudolph, J; Schleich, W; Schubert, C; Schuldt, T; Seidel, S; Sengstock, K; Sopuerta, C F; Sorrentino, F; Summers, D; Tino, G M; Trenkel, C; Uzunoglu, N; von Klitzing, W; Walser, R; Wendrich, T; Wenzlawski, A; Weßels, P; Wicht, A; Wille, E; Williams, M; Windpassinger, P; Zahzam, N

    2013-01-01T23:59:59.000Z

    The theory of general relativity describes macroscopic phenomena driven by the influence of gravity while quantum mechanics brilliantly accounts for microscopic effects. Despite their tremendous individual success, a complete unification of fundamental interactions is missing and remains one of the most challenging and important quests in modern theoretical physics. The STE-QUEST satellite mission, proposed as a medium-size mission within the Cosmic Vision program of the European Space Agency (ESA), aims for testing general relativity with high precision in two experiments by performing a measurement of the gravitational redshift of the Sun and the Moon by comparing terrestrial clocks, and by performing a test of the Universality of Free Fall of matter waves in the gravitational field of Earth comparing the trajectory of two Bose-Einstein condensates of Rb85 and Rb87. The two ultracold atom clouds are monitored very precisely thanks to techniques of atom interferometry. This allows to reach down to an uncerta...

  1. Remote atom entanglement in a fiber-connected three-atom system

    E-Print Network [OSTI]

    Guo Yan-Qing; Chen Jing; Song He-Shan

    2008-05-28T23:59:59.000Z

    An Ising-type atom-atom interaction is obtained in a fiber-connected three-atom system. The interaction is effective when $\\Delta\\approx \\gamma _{0}\\gg g$. The preparations of remote two-atom and three-atom entanglement governed by this interaction are discussed in specific parameters region. The overall two-atom entanglement is very small because of the existence of the third atom. However, the three-atom entanglement can reach a maximum very close to 1.

  2. Collective Atomic Recoil Laser as a synchronization transition

    E-Print Network [OSTI]

    J. Javaloyes; M. Perrin; A. Politi

    2007-12-11T23:59:59.000Z

    We consider here a model previously introduced to describe the collective behavior of an ensemble of cold atoms interacting with a coherent electromagnetic field. The atomic motion along the self-generated spatially-periodic force field can be interpreted as the rotation of a phase oscillator. This suggests a relationship with synchronization transitions occurring in globally coupled rotators. In fact, we show that whenever the field dynamics can be adiabatically eliminated, the model reduces to a self-consistent equation for the probability distribution of the atomic "phases". In this limit, there exists a formal equivalence with the Kuramoto model, though with important differences in the self-consistency conditions. Depending on the field-cavity detuning, we show that the onset of synchronized behavior may occur through either a first- or second-order phase transition. Furthermore, we find a secondary threshold, above which a periodic self-pulsing regime sets in, that is immediately followed by the unlocking of the forward-field frequency. At yet higher, but still experimentally meaningful, input intensities, irregular, chaotic oscillations may eventually appear. Finally, we derive a simpler model, involving only five scalar variables, which is able to reproduce the entire phenomenology exhibited by the original model.

  3. Multimode laser cooling and ultra-high sensitivity force sensing with nanowires

    E-Print Network [OSTI]

    Hosseini, Mahdi; Slatyer, Harri J; Buchler, Ben C; Lam, Ping Koy

    2015-01-01T23:59:59.000Z

    Photo-induced forces can be used to manipulate and cool the mechanical motion of oscillators. When the oscillator is used as a force sensor, such as in atomic force microscopy, active feedback is an enticing route to enhancing measurement performance. Here, we show broadband multimode cooling of $-23$ dB down to a temperature of $8 \\pm 1$~K in the stationary regime. Through the use of periodic quiescence feedback cooling, we show improved signal-to-noise ratios for the measurement of transient signals. We compare the performance of real feedback to numerical post-processing of data and show that both methods produce similar improvements to the signal-to-noise ratio of force measurements. We achieved a room temperature force measurement sensitivity of $< 2\\times10^{-16}$ N with integration time of less than $0.1$ ms. The high precision and fast force microscopy results presented will potentially benefit applications in biosensing, molecular metrology, subsurface imaging and accelerometry.

  4. Observation of cooperative Mie scattering from an ultracold atomic cloud

    SciTech Connect (OSTI)

    Bender, H.; Stehle, C.; Slama, S.; Zimmermann, C. [Physikalisches Institut, Eberhardt-Karls-Universitaet Tuebingen, D-72076 Tuebingen (Germany); Kaiser, R. [Institut Non Lineaire de Nice, CNRS, Universite de Nice Sophia-Antipolis, F-06560 Valbonne (France); Piovella, N. [Dipartimento di Fisica, Universita Degli Studi di Milano, Via Celoria 16, I-20133 Milano (Italy); Courteille, Ph. W. [Physikalisches Institut, Eberhardt-Karls-Universitaet Tuebingen, D-72076 Tuebingen (Germany); Institut Non Lineaire de Nice, CNRS, Universite de Nice Sophia-Antipolis, F-06560 Valbonne (France); Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, 13560-970 Sao Carlos, SP (Brazil)

    2010-07-15T23:59:59.000Z

    Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the distribution, such as its size, shape, and density, although local disorder and density fluctuations may have an important impact on the cooperativity. Via measurements of the radiation pressure force exerted by a far-detuned laser beam on a very small and dense cloud of ultracold atoms, we are able to identify the respective roles of superradiant acceleration of the scattering rate and of Mie scattering in the cooperative process. They lead, respectively, to a suppression or an enhancement of the radiation pressure force. We observe a maximum in the radiation pressure force as a function of the phase shift induced in the incident laser beam by the cloud's refractive index. The maximum marks the borderline of the validity of the Rayleigh-Debye-Gans approximation from a regime, where Mie scattering is more complex. Our observations thus help to clarify the intricate relationship between Rayleigh scattering of light at a coarse-grained ensemble of individual scatterers and Mie scattering at the bulk density distribution.

  5. Demonstration of achromatic cold-neutron microscope utilizing axisymmetric focusing mirrors

    SciTech Connect (OSTI)

    Liu, D.; Khaykovich, B. [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States)] [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States); Hussey, D.; Jacobson, D.; Arif, M. [Physical Measurement Laboratory, NIST, Gaithersburg, Maryland 20899-8461 (United States)] [Physical Measurement Laboratory, NIST, Gaithersburg, Maryland 20899-8461 (United States); Gubarev, M. V.; Ramsey, B. D. [Marshall Space Flight Center, NASA, VP62, Huntsville, Alabama 35812 (United States)] [Marshall Space Flight Center, NASA, VP62, Huntsville, Alabama 35812 (United States); Moncton, D. E. [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States) [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States); Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)

    2013-05-06T23:59:59.000Z

    An achromatic cold-neutron microscope with magnification 4 is demonstrated. The image-forming optics is composed of nested coaxial mirrors of full figures of revolution, so-called Wolter optics. The spatial resolution, field of view, and depth of focus are measured and found consistent with ray-tracing simulations. Methods of increasing the resolution and magnification are discussed, as well as the scientific case for the neutron microscope. In contrast to traditional pinhole-camera neutron imaging, the resolution of the microscope is determined by the mirrors rather than by the collimation of the beam, leading to possible dramatic improvements in the signal rate and resolution.

  6. Dark Forces At The Tevatron

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buckley, Matt [Fermilab; Fileviez Perez, Pavel [Wisconsin U., Madison; Hooper, Dan [Fermilab; Chicago U., Astron. Astrophys. Ctr.; Neil, Ethan [Fermilab

    2011-08-19T23:59:59.000Z

    A simple explanation of the W + dijet excess recently reported by the CDF collaboration involves the introduction of a new gauge boson with sizable couplings to quarks, but with no or highly suppressed couplings to leptons. Anomaly-free theories which include such a leptophobic gauge boson must also include additional particle content, which may include a stable and otherwise viable candidate for dark matter. Based on the couplings and mass of the Z` required to generate the CDF excess, we predict such a dark matter candidate to possess an elastic scattering cross section with nucleons on the order of ? ~ 10-40 cm2, providing a natural explanation for the signals reported by the CoGeNT and DAMA/LIBRA collaborations. In this light, CDF may be observing the gauge boson responsible for the force which mediates the interactions between the dark and visible matter of our universe.

  7. Electronic Friction Dominates Hydrogen Hot-Atom Relaxation on Pd(100) M. Blanco-Rey,1,2

    E-Print Network [OSTI]

    Muiño, Ricardo Díez

    initio molecular dynamics simulations that include a friction force to account for the energy transfer February 2014; published 14 March 2014) We study the dynamics of transient hot H atoms on Pd(100 to the electronic system. We find that the excitation of electron-hole pairs is the main channel for energy

  8. Role of atomic collisions in fusion

    SciTech Connect (OSTI)

    Post, D.E.

    1982-04-01T23:59:59.000Z

    Atomic physics issues have played a large role in controlled fusion research. A general discussion of the present role of atomic processes in both magnetic and inertial controlled fusion work is presented.

  9. Preliminary steps to the Atomic Energy Commission

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    program to the newly created Atomic Energy Commission. He had succeeded in ending the war, but the transition to peacetime use of atomic energy was not something the Army was...

  10. atomic kitteni lauljatar: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  11. atoms barrasiye barhamkoneshhaye: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  12. atomic mass spectrometry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Negative *) Atomic composition Graham, Nick 3 Prospects in Analytical Atomic Spectrometry CERN Preprints Summary: Tendencies in five main branches of atomic spectrometry...

  13. Institute for Atom-Efficient Chemical Transformations Energy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    adsorbed in a zirconium oxide nanobowl. The brown atoms are surface oxygen and the coral atoms are zirconium. Carbon, oxygen, and hydrogen atoms of fructose molecules are...

  14. Towards a high-precision atomic gyroscope

    E-Print Network [OSTI]

    Van Camp, Mackenzie A. (Mackenzie Anne)

    2013-01-01T23:59:59.000Z

    In this thesis, I report on the design and construction of the Rubidium Atomic Gyroscope Experiment (RAGE) at Draper Lab.

  15. Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction Reaction. Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction...

  16. Molecular force spectroscopy of homophilic nectin-1 interactions

    SciTech Connect (OSTI)

    Vedula, Sri Ram Krishna [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Lim, T.S. [Bioinformatics Institute (Singapore); NUS Graduate School for Integrative Sciences and Engineering (Singapore); Hui Shi [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Kausalya, P. Jaya [Institute of Molecular and Cell Biology (Singapore); Lane, E. Birgitte [Institute of Medical Biology (Singapore); Rajagopal, Gunaretnam [Bioinformatics Institute (Singapore); Hunziker, Walter [Institute of Molecular and Cell Biology (Singapore); Lim, C.T. [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)], E-mail: ctlim@nus.edu.sg

    2007-11-03T23:59:59.000Z

    Nectins are Ca{sup 2+} independent cell adhesion molecules localizing at the cadherin based adherens junctions. In this study, we have used atomic force microscopy to study interaction of a chimera of extra cellular fragment of nectin-1 and Fc of human IgG (nef-1) with wild type L-fibroblasts that express endogenous nectin-1 to elucidate the biophysical characteristics of homophilic nectin-1 trans-interactions at the level of single molecule. Bond strength distribution revealed three distinct bound states (or configurations) of trans-interactions between paired nectins, where each bound state has a unique unstressed off-rate and reactive compliance. Kinetic analysis of force-dependent off-rate of the bound state involving trans-interacting V-V domains between paired nectin-1 (unstressed off-rate {approx}1.465 {+-} 0.779 s{sup -1}, reactive compliance {approx}0.143 {+-} 0.072 nm) was found to be closest to E-cadherin, indicating that V-V domain trans-interactions are probably necessary to initiate and promote adhesions of E-cadherin at adherens junctions (AJs)

  17. Scanning tunneling microscopic studies of laser-induced modifications of Si(001)-(2 x 1) surface

    SciTech Connect (OSTI)

    Yasui, Kosuke [Department of Mechanical and Physical Engineering, Osaka City University, Sugimoto 3-3-138, Sumiyoshi, Osaka 558-8585 (Japan); Kanasaki, Jun'ichi [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047 (Japan)

    2011-11-15T23:59:59.000Z

    Scanning tunneling microscopic studies of Si(001)-2 x 1 surfaces excited with 532-nm laser pulses of intensities below melting and ablation thresholds have revealed two different modes of structural modifications, strongly depending on the intensity of laser lights. The excitation below 100 mJ/cm{sup 2} causes bond rupture at individual dimer-sites leading to the formation of vacancies selectively on the outermost layer. The bond rupture, which shows a strongly site-sensitive rate, forms efficiently vacancy-strings elongated along the surface dimer-rows. Selective removal of surface dimers results in the exposure of flat and defect-less underlying layer as reported previously, which is resistive to the excitation at this range of intensity. At intensities above 100 mJ/cm{sup 2}, on the other hand, the excitation forms not only vacancies but also ad-dimers on terraces. The number density of ad-dimers is in proportion to the square of that for vacancies, indicating strongly that silicon atoms released by laser-induced bond rupture are associated with each other to form ad-dimers. The repeated irradiations at this range of intensities induce anisotropic growth of ad-dimer islands and of vacancy clusters on terrace regions, leading to multiply terraced structure. The primary processes of the structural modifications are discussed based on the quantitative analyses of the growth of vacancy and ad-dimer under excitation.

  18. Chaotic Behaviour of Atomic Energy Levels

    E-Print Network [OSTI]

    A. Yilmaz; G. Hacibekiroglu; E. Bolcal; Y. Polatoglu

    2008-04-01T23:59:59.000Z

    The authors of this paper studied Schrodinger wave equation to investiagate the chaotic behavior of atomic energy levels in relation with three quantum numbers n, l, m by means of derived inequality. It could give rise to the siplitting of atomic spectral lines. Keywords: Chaos, Schrodinger wave equation, atomic energy levels

  19. Riso Report No. Danish Atomic Energy Commission

    E-Print Network [OSTI]

    Jagiellonski Institute of Physics Krakow, Poland and P. A. Lindgård Mogensen The Danish Atomic EnergyfM O o 8- OL '·O c/i Riso Report No. Danish Atomic Energy Commission Research Establishment Riso/t on exchangefrom: Library, Danish Atomic Energy Commission, Risd, Roskilde, Denmark #12;May, 1966 Ris6 Report No

  20. Driven Ratchets for Cold Atoms

    E-Print Network [OSTI]

    Renzoni, F

    2011-01-01T23:59:59.000Z

    Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical systems, and indeed ratchets have been realized with a variety of solid state devices, with optical trap setups as well as with synthetic molecules and granular gases. The present article reviews recent experimental realizations of ac driven ratchets with cold atoms in driven optical lattices. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system allowed us to realize experimentally rocking and gating ratchets, and to precisely investigate the relationship between symmetry and transport in these ratchets, both for the case of periodic and quasiperiodic driving.