WorldWideScience

Sample records for spin rotation measurements

  1. Magnetic field devices for neutron spin transport and manipulation in precise neutron spin rotation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado-Velázquez, M. [Posgrado en Ciencias Físicas, Universidad Nacional Autónoma de México, 04510 (Mexico); Barrón-Palos, L., E-mail: libertad@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 (Mexico); Crawford, C. [University of Kentucky, Lexington, KY 40506 (United States); Snow, W.M. [Indiana University, Bloomington, IN 47405 (United States)

    2017-05-11

    The neutron spin is a critical degree of freedom for many precision measurements using low-energy neutrons. Fundamental symmetries and interactions can be studied using polarized neutrons. Parity-violation (PV) in the hadronic weak interaction and the search for exotic forces that depend on the relative spin and velocity, are two questions of fundamental physics that can be studied via the neutron spin rotations that arise from the interaction of polarized cold neutrons and unpolarized matter. The Neutron Spin Rotation (NSR) collaboration developed a neutron polarimeter, capable of determining neutron spin rotations of the order of 10{sup −7} rad per meter of traversed material. This paper describes two key components of the NSR apparatus, responsible for the transport and manipulation of the spin of the neutrons before and after the target region, which is surrounded by magnetic shielding and where residual magnetic fields need to be below 100 μG. These magnetic field devices, called input and output coils, provide the magnetic field for adiabatic transport of the neutron spin in the regions outside the magnetic shielding while producing a sharp nonadiabatic transition of the neutron spin when entering/exiting the low-magnetic-field region. In addition, the coils are self contained, forcing the return magnetic flux into a compact region of space to minimize fringe fields outside. The design of the input and output coils is based on the magnetic scalar potential method.

  2. Muon spin rotation studies

    Science.gov (United States)

    1984-01-01

    The bulk of the muon spin rotation research work centered around the development of the muon spin rotation facility at the Alternating Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The collimation system was both designed and fabricated at Virginia State University. This improved collimation system, plus improvements in detectors and electronics enabled the acquisition of spectra free of background out to 15 microseconds. There were two runs at Brookhaven in 1984, one run was devoted primarily to beam development and the other run allowed several successful experiments to be performed. The effect of uniaxial strain on an Fe(Si) crystal at elevated temperature (360K) was measured and the results are incorporated herein. A complete analysis of Fe pulling data taken earlier is included.

  3. Polarized neutron beam properties for measuring parity-violating spin rotation in liquid {sup 4}He

    Energy Technology Data Exchange (ETDEWEB)

    Micherdzinska, A.M., E-mail: amicherd@gwu.ed [Indiana University/IU Center for Exploration of Energy and Matter, Bloomington, IN 47408 (United States); George Washington University, Washington, DC 20052 (United States); Bass, C.D. [Indiana University/IU Center for Exploration of Energy and Matter, Bloomington, IN 47408 (United States); National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Bass, T.D. [Indiana University/IU Center for Exploration of Energy and Matter, Bloomington, IN 47408 (United States); Gan, K. [George Washington University, Washington, DC 20052 (United States); Luo, D. [Indiana University/IU Center for Exploration of Energy and Matter, Bloomington, IN 47408 (United States); Markoff, D.M. [North Carolina Central University, Durham, NC 27707 (United States); Mumm, H.P.; Nico, J.S. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Opper, A.K. [George Washington University, Washington, DC 20052 (United States); Sharapov, E.I. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Snow, W.M. [Indiana University/IU Center for Exploration of Energy and Matter, Bloomington, IN 47408 (United States); Swanson, H.E. [University of Washington/CENPA, Seattle, WA 98195 (United States); Zhumabekova, V. [Al-Farabi Kazakh National University, Al-Farabi Ave. 71, 050038 Almaty (Kazakhstan)

    2011-03-01

    Measurements of parity-violating neutron spin rotation can provide insight into the poorly understood nucleon-nucleon weak interaction. Because the expected rotation angle per unit length is small (10{sup -7} rad/m), several properties of the polarized cold neutron beam phase space and the neutron optical elements of the polarimeter must be measured to quantify possible systematic effects. This paper presents (1) an analysis of a class of possible systematic uncertainties in neutron spin rotation measurements associated with the neutron polarimetry, and (2) measurements of the relevant neutron beam properties (intensity distribution, energy spectrum, and the product of the neutron beam polarization and the analyzing power as a function of the beam phase space properties) on the NG-6 cold neutron beam-line at the National Institute of Standards and Technology Center for Neutron Research. We conclude that the phase space nonuniformities of the polarimeter in this beam are small enough that a parity-violating neutron spin rotation measurement in n-{sup 4}He with systematic uncertainties at the 10{sup -7} rad/m level is possible.

  4. Muon spin rotation in solids

    Science.gov (United States)

    Stronach, C. E.

    1983-01-01

    The muon spin rotation (MuSR) technique is used to probe the microscopic electron density in materials. High temperature MuSR and magnetization measurements in nickel are in progress to allow an unambiguous determination of the muon impurity interaction and the impurity induced change in local spin density. The first results on uniaxial stress induced frequency shifts in an Fe single crystal are also reported.

  5. Snakes and spin rotators

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1990-01-01

    The generalized snake configuration offers advantages of either shorter total snake length and smaller orbit displacement in the compact configuration or the multi-functions in the split configuration. We found that the compact configuration can save about 10% of the total length of a snake. On other hand, the spilt snake configuration can be used both as a snake and as a spin rotator for the helicity state. Using the orbit compensation dipoles, the spilt snake configuration can be located at any distance on both sides of the interaction point of a collider provided that there is no net dipole rotation between two halves of the snake. The generalized configuration is then applied to the partial snake excitation. Simple formula have been obtained to understand the behavior of the partial snake. Similar principle can also be applied to the spin rotators. We also estimate the possible snake imperfections are due to various construction errors of the dipole magnets. Accuracy of field error of better than 10 -4 will be significant. 2 refs., 5 figs

  6. Muon spin rotation in superconductors

    International Nuclear Information System (INIS)

    Gladisch, M.; Orth, H.; Putlitz, G. zu; Wahl, W.; Wigand, M.; Herlach, D.; Seeger, A.; Metz, H.; Teichler, H.

    1979-01-01

    By means of the muon spin rotation technique (μ + SR), the temperature dependence of the magnetic field inside the normal-conducting domains of high-purity tantalum crystals in the intermediate state has been measured in the temperature range 2.36 K + SR. Possible applications of these findings to the study of long-range diffusion of positive muons at low temperatures are indicated. (Auth.)

  7. COMMISSIONING SPIN ROTATORS IN RHIC

    International Nuclear Information System (INIS)

    MACKAY, W.W.; AHRENS, L.; BAI, M.; COURANT, E.D.; FISCHER, W.; HUANG, H.; LUCCIO, A.; MONTAG, C.; PILAT, F.; PTITSYN, V.; ROSER, T.; SATOGATA, T.; TRBOJEVIC, D.; VANZIEJTS, J.

    2003-01-01

    During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other side. This allows independent control for each beam with vertical, longitudinal, or radial polarization at the experiment. In this paper, we present results from the first run using the new spin rotators at PHENIX

  8. T violating neutron spin rotation asymmetry

    International Nuclear Information System (INIS)

    Masuda, Yasushiro.

    1993-01-01

    A new experiment on T-violation is proposed, where a spin-rotating-neutron transmission through a polarized nuclear target is measuered. The method to control the neutron spin is discussed for the new T-violation experiment. The present method has possibility to provide us more accurate T-violation information than the neutron EDM measurement

  9. Design and Simulation of a Spin Rotator for Longitudinal Field Measurements in the Low Energy Muons Spectrometer

    Science.gov (United States)

    Salman, Z.; Prokscha, T.; Keller, P.; Morenzoni, E.; Saadaoui, H.; Sedlak, K.; Shiroka, T.; Sidorov, S.; Suter, A.; Vrankovic, V.; Weber, H.-P.

    We usedGeant4 to accurately model the low energy muons (LEM) beam line, including scattering due to the 10-nm thin carbon foil in the trigger detector. Simulations of the beam line transmission give excellent agreement with experimental results for beam energies higher than ∼ 12keV.We use these simulations to design and model the operation of a spin rotator for the LEM spectrometer, which will enable longitudinal field measurements in the near future.

  10. Measurements of spin rotation parameter /A in pion-proton elastic scattering at 1.62 GeV/c

    Science.gov (United States)

    Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Svirida, D. N.; Sulimov, A. D.; Zhurkin, V. V.; Beloglazov, Y. A.; Kovalev, A. I.; Kruglov, S. P.; Novinsky, D. V.; Shchedrov, V. A.; Sumachev, V. V.; Trautman, V. Y.; Bazhanov, N. A.; Bunyatova, E. I.

    2000-07-01

    The ITEP-PNPI Collaboration presents the results of the measurements of the spin rotation parameter /A in the elastic scattering of positive and negative pions on protons at Pbeam=1.62 GeV/c. The setup included a longitudinally-polarized proton target with superconductive magnet, multiwire spark chambers and a carbon polarimeter with thick filter. Results are compared with the predictions of partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

  11. Measurements of spin rotation parameter A in pion-proton elastic scattering at 1.62 GeV/c

    OpenAIRE

    Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Svirida, D. N.; Sulimov, A. D.; Zhurkin, V. V.; Beloglazov, Yu. A.; Kovalev, A. I.; Kruglov, S. P.; Novinsky, D. V.; Shchedrov, V. A.

    2000-01-01

    The ITEP-PNPI collaboration presents the results of the measurements of the spin rotation parameter A in the elastic scattering of positive and negative pions on protons at P_beam = 1.62 GeV/c. The setup included a longitudinally-polarized proton target with superconductive magnet, multiwire spark chambers and a carbon polarimeter with thick filter. Results are compared to the predictions of partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

  12. Effect of spin rotation coupling on spin transport

    International Nuclear Information System (INIS)

    Chowdhury, Debashree; Basu, B.

    2013-01-01

    We have studied the spin rotation coupling (SRC) as an ingredient to explain different spin-related issues. This special kind of coupling can play the role of a Dresselhaus like coupling in certain conditions. Consequently, one can control the spin splitting, induced by the Dresselhaus like term, which is unusual in a semiconductor heterostructure. Within this framework, we also study the renormalization of the spin-dependent electric field and spin current due to the k → ⋅p → perturbation, by taking into account the interband mixing in the rotating system. In this paper we predict the enhancement of the spin-dependent electric field resulting from the renormalized spin rotation coupling. The renormalization factor of the spin electric field is different from that of the SRC or Zeeman coupling. The effect of renormalized SRC on spin current and Berry curvature is also studied. Interestingly, in the presence of this SRC-induced SOC it is possible to describe spin splitting as well as spin galvanic effect in semiconductors. -- Highlights: •Studied effect of spin rotation coupling on the spin electric field, spin current and Berry curvature. •In the k → ⋅p → framework we study the renormalization of spin electric field and spin current. •For an inertial system we have discussed the spin splitting. •Expression for the Berry phase in the inertial system is discussed. •The inertial spin galvanic effect is studied

  13. Field of first magnetic flux entry and pinning strength of superconductors for rf application measured with muon spin rotation

    Science.gov (United States)

    Junginger, T.; Abidi, S. H.; Maffett, R. D.; Buck, T.; Dehn, M. H.; Gheidi, S.; Kiefl, R.; Kolb, P.; Storey, D.; Thoeng, E.; Wasserman, W.; Laxdal, R. E.

    2018-03-01

    The performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry Hentry and pinning strength. The former sets the limit for the maximum achievable accelerating gradient, while the latter determines how efficiently flux can be expelled related to the maximum achievable quality factor. In this paper, a method based on muon spin rotation (μ SR ) is developed to probe these parameters on samples. It combines measurements from two different spectrometers, one being specifically built for these studies and samples of different geometries. It is found that annealing at 1400 °C virtually eliminates all pinning. Such an annealed substrate is ideally suited to measure Hentry of layered superconductors, which might enable accelerating gradients beyond bulk niobium technology.

  14. Measurement of the spin rotation parameter A in the elastic pion-proton scattering at 1.43 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.G.; Budkovsky, P.E.; Kanavets, V.P.; Koroleva, L.I.; Morozov, B.V.; Nesterov, V.M.; Ryltsov, V.V.; Sulimov, A.D.; Svirida, D.N.; Zhurkin, V.V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bazhanov, N.A.; Bunyatova, E.I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kovalev, A.I.; Kruglov, S.P.; Novinsky, D.V.; Shchedrov, V.A.; Sumachev, V.V.; Trautman, V. Yu. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation)

    2006-02-01

    The ITEP-PNPI collaboration presents new results of the measurements of the spin rotation parameter A in the elastic scattering of negative pions on protons at P{sub beam}=1.43 GeV/c. The results are compared to the predictions of several partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow. (orig.)

  15. Measurement of the spin rotation parameter Ain the elastic pion-proton scattering at 1.43 GeV/c

    Science.gov (United States)

    Alekseev, I. G.; Bazhanov, N. A.; Budkovsky, P. E.; Bunyatova, E. I.; Kanavets, V. P.; Kovalev, A. I.; Koroleva, L. I.; Kruglov, S. P.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Shchedrov, V. A.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Trautman, V. Yu; Zhurkin, V. V.

    2006-02-01

    The ITEP-PNPI collaboration presents new results of the measurements of the spin rotation parameter A in the elastic scattering of negative pions on protons at P beam = 1.43 GeV/c. The results are compared to the predictions of several partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

  16. Measurement of the spin rotation parameter A in the elastic pion- proton scattering at 1.43 GeV/c

    CERN Document Server

    Alekseev, I G; Budkovsky, P E; Bunyatova, E I; Kanavets, V P; Koroleva, L I; Kovalev, A I; Kruglov, S P; Morozov, B V; Nesterov, V M; Novinsky, D V; Ryltzov, V V; Shchedrov, V A; Sulimov, A D; Sumachev, V V; Svirida, D N; Trautman, V Yu; Zhurkin, V V

    2004-01-01

    The ITEP-PNPI collaboration presents new results of the measurements of the spin rotation parameter A in the elastic scattering of negative pions on protons at P/sub beam/ = 1.43 GeV/c. The results are compared to the predictions of the different partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

  17. Measurement of the Spin Rotation Parameter A in the Elastic Pion-proton Scattering at 1.43 GeV/c

    OpenAIRE

    Alekseev, I. G.; Bazhanov, N. A.; Budkovsky, P. E.; Bunyatova, E. I.; Kanavets, V. P.; Kovalev, A. I.; Koroleva, L. I.; Kruglov, S. P.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Shchedrov, V. A.; Sulimov, A. D.; Sumachev, V. V.

    2005-01-01

    The ITEP-PNPI collaboration presents new results of the measurements of the spin rotation parameter A in the elastic scattering of negative pions on protons at P_beam=1.43 GeV/c. The results are compared to the predictions of several partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

  18. Measurements of the spin rotation parameter R in high energy elastic scattering and helicity amplitudes at Serpukhov energies

    International Nuclear Information System (INIS)

    Pierrard, J.; Bruneton, C.; Bystricky, J.; Cozzika, G.; Deregel, J.; Ducros, Y.; Gaidot, A.; Khantine-Langlois, F.; Lehar, F.; Lesquen, A. de; Merlo, J.P.; Miyashita, S.; Movchet, J.; Raoul, J.C.; Van Rossum, L.; Kanavets, V.P.

    1975-01-01

    The spin rotation parameter R in pp and π + p elastic scattering at 45GeV/c has been measured at the Serpukhov accelerator, for /t/ ranging from 0.2 to 0.5(GeV/c) 2 . The results are presented, together with previous R measurements at 3.8, 6, 16 and 40GeV/c, and are compared with the predictions of Regge pole models. The equality of the values for R in proton-proton and pion-proton scattering, within the experimental errors, is a test of factorization of the residues. An s-channel helicity amplitude analysis for pion-nucleon scattering at 40GeV/c is made using all available data. Significant results are obtained for the non flip amplitude in isoscalar exchange and for flip amplitudes on both isovector and isoscalar exchanges. The helicity flip in isoscalar exchange is non negligible. The energy dependence of this amplitude, at 6, 16 and 40GeV/c, is compared with predictions of Regge pole models [fr

  19. Helical spin rotators and snakes for RHIC

    International Nuclear Information System (INIS)

    Ptitsin, V.I.; Shatunov, Yu.M.; Peggs, S.

    1995-01-01

    The RHIC collider, now under construction at BNL, will have the possibility of polarized proton-proton collisions up to a beam energy of 250 Gev. Polarized proton beams of such high energy can be only obtained with the use of siberian snakes, a special kind of spin rotator that rotates the particle spin by 180 degree around an axis lying in the horizontal plane. Siberian snakes help to preserve the beam polarization while numerous spin depolarizing resonances are crossed, during acceleration. In order to collide longitudinally polarized beams, it is also planned to install spin rotators around two interaction regions. This paper discusses snake and spin rotator designs based on sequences of four helical magnets. The schemes that were chosen to be applied at RHIC are presented

  20. Materials science with muon spin rotation

    Science.gov (United States)

    1988-01-01

    During this reporting period, the focus of activity in the Materials Science with Muon Spin Rotation (MSMSR) program was muon spin rotation studies of superconducting materials, in particular the high critical temperature and heavy-fermion materials. Apart from these studies, work was continued on the analysis of muon motion in metal hydrides. Results of these experiments are described in six papers included as appendices.

  1. Coherent spin-rotational dynamics of oxygen superrotors

    Science.gov (United States)

    Milner, Alexander A.; Korobenko, Aleksey; Milner, Valery

    2014-09-01

    We use state- and time-resolved coherent Raman spectroscopy to study the rotational dynamics of oxygen molecules in ultra-high rotational states. While it is possible to reach rotational quantum numbers up to N≈ 50 by increasing the gas temperature to 1500 K, low population levels and gas densities result in correspondingly weak optical response. By spinning {{O}2} molecules with an optical centrifuge, we efficiently excite extreme rotational states with N≤slant 109 in high-density room temperature ensembles. Fast molecular rotation results in the enhanced robustness of the created rotational wave packets against collisions, enabling us to observe the effects of weak spin-rotation coupling in the coherent rotational dynamics of oxygen. The decay rate of spin-rotational coherence due to collisions is measured as a function of the molecular angular momentum and its dependence on the collisional adiabaticity parameter is discussed. We find that at high values of N, the rotational decoherence of oxygen is much faster than that of the previously studied non-magnetic nitrogen molecules, pointing at the effects of spin relaxation in paramagnetic gases.

  2. Spin rotation and oscillations for high energy particles in a crystal and possibility to measure the quadrupole moments and tensor polarizabilities of elementary particles and nuclei

    OpenAIRE

    Baryshevsky, V. G.; Gurinovich, A. A.

    2005-01-01

    It is shown that particle motion in a bent (straight) crystal is accompanied by particle spin rotation and oscillations that allows to measure the tensor electric and magnetic polarizabilities of nuclei and elementary particles. It is shown that channelling of particles in either straight or bent crystal with the polarized nuclei could be used both to analyze polarization of high energy particles and polarize them.

  3. Spin Tunneling in a Rotating Nanomagnet

    Science.gov (United States)

    O'Keeffe, Michael; Chudnovsky, Eugene; Lehman College Theoretical Condensed Matter Physics Team

    2011-03-01

    We study spin tunneling in a magnetic nanoparticle with biaxial anisotropy that is free to rotate about its anisotropy axis. Exact instanton of the coupled equations of motion is found that connects degenerate classical energy minima. We show that mechanical freedom of the particle renormalizes magnetic anisotropy and increases the tunnel splitting. M. F. O'Keeffe and E. M. Chudnovsky, cond-mat, arXiv:1011.3134.

  4. Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

    OpenAIRE

    Baryshevsky, V. G.

    2015-01-01

    We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magneti...

  5. PREFACE: Muon spin rotation, relaxation or resonance

    Science.gov (United States)

    Heffner, Robert H.; Nagamine, Kanetada

    2004-10-01

    To a particle physicist a muon is a member of the lepton family, a heavy electron possessing a mass of about 1/9 that of a proton and a spin of 1/2, which interacts with surrounding atoms and molecules electromagnetically. Since its discovery in 1937, the muon has been put to many uses, from tests of special relativity to deep inelastic scattering, from studies of nuclei to tests of weak interactions and quantum electrodynamics, and most recently, as a radiographic tool to see inside heavy objects and volcanoes. In 1957 Richard Garwin and collaborators, while conducting experiments at the Columbia University cyclotron to search for parity violation, discovered that spin-polarized muons injected into materials might be useful to probe internal magnetic fields. This eventually gave birth to the modern field of muSR, which stands for muon spin rotation, relaxation or resonance, and is the subject of this special issue of Journal of Physics: Condensed Matter. Muons are produced in accelerators when high energy protons (generally >500 MeV) strike a target like graphite, producing pions which subsequently decay into muons. Most experiments carried out today use relatively low-energy (~4 MeV), positively-charged muons coming from pions decaying at rest in the skin of the production target. These muons have 100% spin polarization, a range in typical materials of about 180 mg cm-2, and are ideal for experiments in condensed matter physics and chemistry. Negatively-charged muons are also occasionally used to study such things as muonic atoms and muon-catalysed fusion. The muSR technique provides a local probe of internal magnetic fields and is highly complementary to inelastic neutron scattering and nuclear magnetic resonance, for example. There are four primary muSR facilities in the world today: ISIS (Didcot, UK), KEK (Tsukuba, Japan), PSI (Villigen, Switzerland) and TRIUMF (Vancouver, Canada), serving about 500 researchers world-wide. A new facility, JPARC (Tokai, Japan

  6. More on rotations as spin matrix polynomials

    International Nuclear Information System (INIS)

    Curtright, Thomas L.

    2015-01-01

    Any nonsingular function of spin j matrices always reduces to a matrix polynomial of order 2j. The challenge is to find a convenient form for the coefficients of the matrix polynomial. The theory of biorthogonal systems is a useful framework to meet this challenge. Central factorial numbers play a key role in the theoretical development. Explicit polynomial coefficients for rotations expressed either as exponentials or as rational Cayley transforms are considered here. Structural features of the results are discussed and compared, and large j limits of the coefficients are examined

  7. Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation.

    Science.gov (United States)

    Drew, A J; Pratt, F L; Lancaster, T; Blundell, S J; Baker, P J; Liu, R H; Wu, G; Chen, X H; Watanabe, I; Malik, V K; Dubroka, A; Kim, K W; Rössle, M; Bernhard, C

    2008-08-29

    Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An estimate of the in-plane penetration depth lambda ab(0)=190(5) nm was obtained, which confirms that the pnictide superconductors obey an Uemura-style relationship between Tc and lambda ab(0);(-2).

  8. Predicting superdeformed rotational band-head spin in A∼ 190 ...

    Indian Academy of Sciences (India)

    The band-head spin (0) of superdeformed (SD) rotational bands in ∼ 190 mass region is predicted using the variable moment of inertia (VMI) model for 66 SD rotational bands. The superdeformed rotational bands exhibited considerably good rotational property and rigid behaviour. The transition energies were ...

  9. Generation of spin currents due to mechanical rotation

    Science.gov (United States)

    Matsuo, Mamoru; Ieda, Jun'ichi; Saitoh, Eiji; Maekawa, Sadamichi

    2011-03-01

    In the frontier of spintronics, much attention is paid on the control and generation of spin currents. Due to the exciting progress of nanomechatrononics, the importance of mechanical manipulation of electron spin will increase. We discuss theoretically effects of mechanical rotation on spin currents using generally covariant Dirac equation with gauge fields in the non-relativistic limit. We derive semi-classical equations of motion for a wavepacket of electrons in two dimentional planes subject to the spin-orbit interaction argumented by a mechanical rotation. We show that a circular spin current is created by the mechanical rotation with a magnetic field. The magnitude of the spin current becomes 108A/m2 in Pt with the magnetic field ~ 1 T and the rotational velocity ~ 1 kHz.

  10. Measurements of the spin rotation parameter A in the elastic pion-proton scattering in the D13(1700) resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.G.; Budkovsky, P.E.; Kanavets, V.P.; Koroleva, L.I.; Morozov, B.V.; Nesterov, V.M.; Ryltsov, V.V.; Sulimov, A.D.; Svirida, D.N.; Zhurkin, V.V. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Bazhanov, N.A.; Bunyatova, E.I. [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Beloglazov, Yu.A.; Kovalev, A.I.; Kruglov, S.P.; Novinsky, D.V.; Shchedrov, V.A.; Sumachev, V.V.; Trautman, V.Yu. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation)

    2001-09-01

    The spin rotation parameters A and R were measured for the elastic pion-proton scattering by the PNPI-ITEP collaboration in the D{sub 13}(1700) resonance region. The main goal of the experimental program is to resolve the current partial-wave analyses (PWA) uncertainties. Simultaneously with A and R the polarization parameter P was measured with the purpose to improve the experimental database and estimate systematic errors. The constraint which demands a smooth energy dependence of all {pi}{sup -}p transverse amplitude zeros in the complex plane together with the new experimental data on A parameter can lead to the conclusion that the Barrelet branch of ''zero trajectories'' is chosen improperly in PWA of the Carnegie-Mellon-Lawrence-Berkeley-Laboratory groups at the range of the pion beam momentum near 1.0 GeV/c. The setup included a longitudinally polarized proton target with superconductive magnet, multiwire spark chambers and carbon polarimeter with thick filter. The experiment was performed at the ITEP proton synchrotron, Moscow. (orig.)

  11. Measurements of the spin rotation parameterf A in the elastic pion- proton scattering in the D$_{13}$(1700) resonance region

    CERN Document Server

    Alekseev, I G; Beloglasov, Yu A; Budkovsky, P E; Bunyatova, E I; Kanavets, V P; Kovalev, A I; Koroleva, L I; Kruglov, S P; Morozov, B V; Nesterov, V M; Novinsky, D V; Ryltzov, V V; Shchedrov, V A; Sulimov, A D; Sumachev, Yu V; Svirida, D N; Trautman, V Yu; Zhurkin, V V

    2001-01-01

    The spin rotation parameters A and R were measured for the elastic pion-proton scattering by the PNPI-ITEP collaboration in the D/sub 13 /(1700) resonance region. The main goal of the experimental program is to resolve the current partial-wave analyses (PWA) uncertainties. Simultaneously with A and R the polarization parameter P was measured with the purpose to improve the experimental database and estimate systematic errors. The constraint which demands a smooth energy dependence of all pi /sup -/p transverse amplitude zeros in the complex plane together with the new experimental data on the A parameter can lead to the conclusion that the Barrelet branch of "zero trajectories" is chosen improperly in PWA of the Carnegie- Mellon-Lawrence-Berkeley-Laboratory groups at the range of the pion beam momentum near 1.0 GeV/c. The setup included a longitudinally polarized proton target with superconductive magnet, multiwire spark chambers and carbon polarimeter with thick filter. The experiment was performed at the IT...

  12. Spin-stabilized magnetic levitation without vertical axis of rotation

    Science.gov (United States)

    Romero, Louis [Albuquerque, NM; Christenson, Todd [Albuquerque, NM; Aaronson, Gene [Albuquerque, NM

    2009-06-09

    The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

  13. Spins of superdeformed rotational bands in Tl isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dadwal, Anshul; Mittal, H.M. [Dr. B.R. Ambedkar National Institute of Technology, Jalandhar (India)

    2017-01-15

    The two-parameter model defined for even-even nuclei viz. soft-rotor formula is used to assign the band-head spin of the 17 rotational bands in Tl isotopes. The least-squares fitting method is employed to obtain the spins of these bands in the A ∝ 190 mass region. The calculated transition energies are found to depend sensitively on the proposed spin. Whenever a correct spin assignment is made, the calculated and experimental transition energies coincide very well. The dynamic moment of inertia is also calculated and its variation with rotational frequency is explored. (orig.)

  14. Measurement of the magnetic moment of the positive muon by a stroboscopic muon-spin-rotation technique

    International Nuclear Information System (INIS)

    Klempt, E.; Schulze, R.; Wolf, H.; Camani, M.; Gygax, F.N.; Rueegg, W.; Schenck, A.; Schilling, H.

    1982-01-01

    A new determination of the magnetic moment of the positive muon in units of the magnetic moment of the proton is presented. The Larmor precession of positive muons in liquid bromine was observed by a stroboscopic technique in a field of 0.75 T and combined with concomitant proton NMR measurements in the same chemical environment. The stroboscopic method allows use of the full muon stopping rate available at the Schweizerisches Institut fuer Nuklearforschung (SIN) muon channel. Moreover, it permits an intrinsically precise determination of muon Larmor frequency and proton NMR frequency measuring the magnetic field by comparison with the stable reference frequency of the SIN accelerator (ΔΩ/Ωroughly-equal10 -8 ). Two different bromine targets were used which allowed an unambiguous determination of the chemical field shift experienced by the muons. One target contained pure and water-free liquid bromine (Br 2 ), where stopped muons form (μ + e - )Br molecules. The other target was slightly contaminated with water; there a chemical reaction chain places the muons into (μ + e - )HO molecules. The diamagnetic shielding of protons in the analogous molecules HBr and H 2 O in liquid bromine was measured by high-resolution NMR. Values for the isotopic shift of the diamagnetic shielding, when protons are replaced by muons, are available from quantum chemical calculations. After application of the chemical-shift corrections, the results from the two different bromine targets are consistent. The final result is μ/sub μ//μ/sub p/ = 3.183 344 1(17) (or +- 0.53 ppm). This value agrees with other recent precision determinations of μ/sub μ//μ/sub p/. For the muon mass the present result implies m/sub μ//m/sub e/ = 206.768 35(11)

  15. Muon spin rotation and other microscopic probes of spin-glass dynamics

    International Nuclear Information System (INIS)

    MacLaughlin, D.E.

    1980-01-01

    A number of different microscopic probe techniques have been employed to investigate the onset of the spin-glass state in dilute magnetic alloys. Among these are Moessbauer-effect spectroscopy, neutron scattering, ESR of the impurity spins, host NMR and, most recently, muon spin rotation and depolarization. Spin probes yield information on the microscopic static and dynamic behavior of the impurity spins, and give insight into both the spin freezing process and the nature of low-lying excitations in the ordered state. Microscopic probe experiments in spin glasses are surveyed, and the unique advantages of muon studies are emphasized

  16. Numerical studies of Siberian snakes and spin rotators for RHIC

    International Nuclear Information System (INIS)

    Luccio, A.

    1995-01-01

    For the program of polarized protons in RHIC, two Siberian snakes and four spin rotators per ring will be used. The Snakes will produce a complete spin flip. Spin Rotators, in pairs, will rotate the spin from the vertical direction to the horizontal plane at a given insertion, and back to the vertical after the insertion. Snakes, 180 degrees apart and with their axis of spin precession at 90 degrees to each other, are an effective means to avoid depolarization of the proton beam in traversing resonances. Classical snakes and rotators are made with magnetic solenoids or with a sequence of magnetic dipoles with fields alternately directed in the radial and vertical direction. Another possibility is to use helical magnets, essentially twisted dipoles, in which the field, transverse the axis of the magnet, continuously rotates as the particles proceed along it. After some comparative studies, the authors decided to adopt for RHIC an elegant solution with four helical magnets both for the snakes and the rotators proposed by Shatunov and Ptitsin. In order to simplify the construction of the magnets and to minimize cost, four identical super conducting helical modules will be used for each device. Snakes will be built with four right-handed helices. Spin rotators with two right-handed and two left-handed helices. The maximum field will be limited to 4 Tesla. While small bore helical undulators have been built for free electron lasers, large super conducting helical magnets have not been built yet. In spite of this difficulty, this choice is dictated by some distinctive advantages of helical over more conventional transverse snakes/rotators: (i) the devices are modular, they can be built with arrangements of identical modules, (ii) the maximum orbit excursion in the magnet is smaller, (iii) orbit excursion is independent from the separation between adjacent magnets, (iv) they allow an easier control of the spin rotation and the orientation of the spin precession axis

  17. Spin currents of charged Dirac particles in rotating coordinates

    Science.gov (United States)

    Dayi, Ö. F.; Yunt, E.

    2018-03-01

    The semiclassical Boltzmann transport equation of charged, massive fermions in a rotating frame of reference, in the presence of external electromagnetic fields is solved in the relaxation time approach to establish the distribution function up to linear order in the electric field in rotating coordinates, centrifugal force and the derivatives. The spin and spin current densities are calculated by means of this distribution function at zero temperature up to the first order. It is shown that the nonequilibrium part of the distribution function yields the spin Hall effect for fermions constrained to move in a plane perpendicular to the angular velocity and magnetic field. Moreover it yields an analogue of Ohm's law for spin currents whose resistivity depends on the external magnetic field and the angular velocity of the rotating frame. Spin current densities in three-dimensional systems are also established.

  18. Studies of superconducting materials with muon spin rotation

    Science.gov (United States)

    Davis, Michael R.; Stronach, Carey E.; Kossler, W. J.; Schone, H. E.; Yu, X. H.; Uemura, Y. J.; Sternlieb, B. J.; Kempton, J. R.; Oostens, J.; Lankford, W. F.

    1989-01-01

    The muon spin rotation/relaxation technique was found to be an exceptionally effective means of measuring the magnetic properties of superconductors, including the new high temperature superconductor materials, at the microscopic level. The technique directly measures the magnetic penetration depth (type II superconductors (SC's)) and detects the presence of magnetic ordering (antiferromagnetism or spin-glass ordering were observed in some high temperature superconductor (HTSC's) and in many closely related compounds). Extensive studies of HTSC materials were conducted by the Virginia State University - College of William and Mary - Columbia University collaboration at Brookhaven National Laboratory and TRIUMF (Vancouver). A survey of LaSrCuO and YBaCaCuO systems shows an essentially linear relationship between the transition temperature T(sub c) and the relaxation rate. This appears to be a manifestation of the proportionality between T(sub c) and the Fermi energy, which suggests a high energy scale for the SC coupling, and which is not consistent with the weak coupling of phonon-mediated SC. Studies of LaCuO and YBaCuO parent compounds show clear evidence of antiferromagnetism. YBa2Cu(3-x)CO(x)O7 shows the simultaneous presence of spin-glass magnetic ordering and superconductivity. Three-dimensional SC, (Ba, K) BiO3, unlike the layered CuO-based compounds, shows no suggestion of magnetic ordering. Experimental techniques and theoretical implications are discussed.

  19. The first muon spin rotation experiment

    International Nuclear Information System (INIS)

    Garwin, Richard L.

    2003-01-01

    The February 15, 1957 issue of Physical Review Letters shows the first muon precession curve resulting from the stopping of '85 MeV' muons in graphite, and the resulting counting rate in a gate of fixed delay, duration, and orientation, as a function of an applied vertical magnetic field. The purpose of the four-day experiment was to test the conservation of parity in the weak interactions. It involved the sudden recognition that existing muon beams would be polarized if parity were not conserved, together with the appreciation that the angular distribution of decay electrons from the population of stopped muons could be observed (much more reliably and sensitively) by the variation with time or current of the detections in a fixed counter telescope than by the measurement of the decay asymmetry of nominally fixed muon spins. This retrospective paper explains the context, the state of the art at the time, and what we expected as a consequence of this experiment. We went on to study more accurately the magnetic moment of the muon, its gyromagnetic ratio--g --and only to a small extent used μSR to investigate the environment of the muon in matter. Much of the paper treats the instrumentation of the time--especially that adopted in the early 1950s. The essential tools of nanosecond-range coincidence circuits and adiabatic light pipes for scintillation counters are discussed. The paper closes with some later work of the author and his colleagues--measurements of the magnetic moment of the muon and especially the CERN measurement of muon g-2. An expanded version of this presentation is posted at http://www.fas.org/RLG

  20. The first muon spin rotation experiment

    CERN Document Server

    Garwin, Richard L

    2003-01-01

    The February 15, 1957 issue of Physical Review Letters shows the first muon precession curve resulting from the stopping of `85 MeV' muons in graphite, and the resulting counting rate in a gate of fixed delay, duration, and orientation, as a function of an applied vertical magnetic field. The purpose of the four-day experiment was to test the conservation of parity in the weak interactions. It involved the sudden recognition that existing muon beams would be polarized if parity were not conserved, together with the appreciation that the angular distribution of decay electrons from the population of stopped muons could be observed (much more reliably and sensitively) by the variation with time or current of the detections in a fixed counter telescope than by the measurement of the decay asymmetry of nominally fixed muon spins. This retrospective paper explains the context, the state of the art at the time, and what we expected as a consequence of this experiment. We went on to study more accurately the magneti...

  1. Vibration dependence of the tensor spin-spin and scalar spin-spin hyperfine interactions by precision measurement of hyperfine structures of 127I2 near 532 nm

    International Nuclear Information System (INIS)

    Hong Fenglei; Zhang Yun; Ishikawa, Jun; Onae, Atsushi; Matsumoto, Hirokazu

    2002-01-01

    Hyperfine structures of the R(87)33-0, R(145)37-0, and P(132)36-0 transitions of molecular iodine near 532 nm are measured by observing the heterodyne beat-note signal of two I 2 -stabilized lasers, whose frequencies are bridged by an optical frequency comb generator. The measured hyperfine splittings are fit to a four-term Hamiltonian, which includes the electric quadrupole, spin-rotation, tensor spin-spin, and scalar spin-spin interactions, with an accuracy of ∼720 Hz. High-accurate hyperfine constants are obtained from this fit. Vibration dependences of the tensor spin-spin and scalar spin-spin hyperfine constants are determined for molecular iodine, for the first time to our knowledge. The observed hyperfine transitions are good optical frequency references in the 532-nm region

  2. Black Hole Spin Measurement Uncertainty

    Science.gov (United States)

    Salvesen, Greg; Begelman, Mitchell C.

    2018-01-01

    Angular momentum, or spin, is one of only two fundamental properties of astrophysical black holes, and measuring its value has numerous applications. For instance, obtaining reliable spin measurements could constrain the growth history of supermassive black holes and reveal whether relativistic jets are powered by tapping into the black hole spin reservoir. The two well-established techniques for measuring black hole spin can both be applied to X-ray binaries, but are in disagreement for cases of non-maximal spin. This discrepancy must be resolved if either technique is to be deemed robust. We show that the technique based on disc continuum fitting is sensitive to uncertainties regarding the disc atmosphere, which are observationally unconstrained. By incorporating reasonable uncertainties into black hole spin probability density functions, we demonstrate that the spin measured by disc continuum fitting can become highly uncertain. Future work toward understanding how the observed disc continuum is altered by atmospheric physics, particularly magnetic fields, will further strengthen black hole spin measurement techniques.

  3. Birefringence (spin rotation and spin dichroism) of high-energy deuterons

    International Nuclear Information System (INIS)

    Baryshevskij, V.G.; Rovba, A.A.

    2016-01-01

    The phenomenon of birefringence (spin rotation and spin dichroism) of high-energy deuterons, currently observed in experiments, is the macroscopic quantum effect similar to the birefringence effect known in optics. This paper considers the contribution coming to the spin dichroism effect from the interaction of deuteron electric quadrupole moment and nuclear electric field. The effect proves to be responsive to the behavior of deuteron ground state wave functions at a small distance. [ru

  4. High spin rotational bands in Zn

    Indian Academy of Sciences (India)

    and 46 new transitions (marked by an asterisk in figure 1) have been observed and prop- erly placed in the level scheme, thereby the level scheme is extended up to an excitation energy of 10.574 MeV and spin-parity of (41/2· ). This data establishes transitions at. 1074, 1155, 1227, and 1349 keV which form the upper part ...

  5. Cosmic-ray muon spin rotation in Fe and industrial application

    Science.gov (United States)

    Nagamine, K.; Fujimaki, T.; Hashimoto, T.; Tsukamoto, M.; Kubota, S.; Hirai, T.; Manabe, A.; Tomisawa, Y.; Pant, A. D.; Torikai, E.

    2014-12-01

    Spin polarized positive muons contained in the cosmic-rays were stopped in the Fe plates providing a characteristic spin rotation signal of decay positrons. This signal along with the decay lifetime of the negative muons can be used as a non-invasive radiographic measurement method for a characterization of the inner structure of the aged architectures. Principle, results of test experiments and future prospects are described.

  6. NMR in rotating magnetic fields: Magic angle field spinning

    Energy Technology Data Exchange (ETDEWEB)

    Sakellariou, D.; Meriles, C.; Martin, R.; Pines, A.

    2004-09-10

    Magic angle sample spinning has been one of the cornerstones in high-resolution solid state NMR. Spinning frequencies nowadays have increased by at least one order of magnitude over the ones used in the first experiments and the technique has gained tremendous popularity. It is currently a routine procedure in solid-state NMR, high-resolution liquid-state NMR and solid-state MRI. The technique enhances the spectral resolution by averaging away rank 2 anisotropic spin interactions thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings. Andrew proposed that it should be possible to induce similar effects in a static sample if the direction of the magnetic field is varied, e.g., magic-angle rotation of the B0 field (B0-MAS) and this has been recently demonstrated using electromagnetic field rotation. Here we discuss on the possibilities to perform field rotation using alternative hardware, together with spectroscopic methods to recover isotropic resolution even in cases where the field is not rotating at the magic angle. Extension to higher magnetic fields would be beneficial in situations where the physical manipulation of the sample is inconvenient or impossible. Such situations occur often in materials or biomedical samples where ''ex-situ'' NMR spectroscopy and imaging analysis is needed.

  7. Spin and rotations in Galois field quantum mechanics

    International Nuclear Information System (INIS)

    Chang, Lay Nam; Lewis, Zachary; Minic, Djordje; Takeuchi, Tatsu

    2013-01-01

    We discuss the properties of Galois field quantum mechanics constructed on a vector space over the finite Galois field GF(q). In particular, we look at two-level systems analogous to spin, and discuss how SO(3) rotations could be embodied in such a system. We also consider two-particle ‘spin’ correlations and show that the Clauser–Horne-Shimony–Holt inequality is nonetheless not violated in this model. (paper)

  8. Spin-rotation and NMR shielding constants in HCl

    International Nuclear Information System (INIS)

    Jaszuński, Michał; Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth; Garbacz, Piotr; Jackowski, Karol; Makulski, Włodzimierz

    2013-01-01

    The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of 1 H 35 Cl are C Cl   = −53.914 kHz and C H   = 42.672 kHz (for the lowest rovibrational level). For the chlorine shielding constant, the ab initio value computed including the relativistic corrections, σ(Cl) = 976.202 ppm, provides a new absolute shielding scale; for hydrogen we find σ(H) = 31.403 ppm (both at 300 K). Combining the theoretical results with our new gas-phase NMR experimental data allows us to improve the accuracy of the magnetic dipole moments of both chlorine isotopes. For the hydrogen shielding constant, including relativistic effects yields better agreement between experimental and computed values

  9. High spin rotations of nuclei with the harmonic oscillator potential

    International Nuclear Information System (INIS)

    Cerkaski, M.; Szymanski, Z.

    1978-01-01

    Calculations of the nuclear properties at high angular momentum have been performed recently. They are based on the liquid drop model of a nucleus and/or on the assumption of the single particle shell structure of the nucleonic motion. The calculations are usually complicated and involve long computer codes. In this article we shall discuss general trends in fast rotating nuclei in the approximation of the harmonic oscillator potential. We shall see that using the Bohr Mottelson simplified version of the rigorous solution of Valatin one can perform a rather simple analysis of the rotational bands, structure of the yrast line, moments of inertia etc. in the rotating nucleus. While the precision fit to experimental data in actual nuclei is not the purpose of this paper, one can still hope to reach some general understanding within the model of the simple relations resulting in nuclei at high spin. (author)

  10. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.

  11. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    International Nuclear Information System (INIS)

    Mueller, K.T.; California Univ., Berkeley, CA

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-1/2 nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids

  12. Cycloid trajectory for a spin in a rotating magnetic field

    Science.gov (United States)

    Oh, Sangchul; Hu, Xuedong

    2013-03-01

    A cycloid is a curve traced by a point on the rim of a circle rolling on a straight (or in general, a base) line. In classical mechanics, it is known as the solution of two famous problems: the brachistochrone (least-time) curve and tautochrone (equal-time) curve. Here we show that a cycloid is the quantum trajectory on the Bloch sphere when a spin is dragged along by a rotating magnetic field. Here an imaginary circle, whose radius is determined by how fast the magnetic field is rotating, rolls on the base line of the rotating magnetic field on the Bloch sphere. If the magnetic field rotates slower, the radius of the rolling circle shrinks (to a point at the adiabatic limit, when the trajectory traces a circle that spans a solid angle proportional to the Berry phase). We find that like classical cycloid curves, the curtate cycloid on a Bloch sphere is generated for initial states within a circle on the Bloch sphere surface, and a prolate cycloid results from initial states outside of this circle. If the initial state is given by the center of the circle, the quantum trajectory is a line of a constant latitude on the Bloch sphere, parallel to the curve of the rotating magnetic field.

  13. Spin-down of a rotating air hockey disk

    Science.gov (United States)

    Weidman, Patrick; Julien, Keith

    2013-11-01

    We extend the work of Weidman (APS, DFD 2008) on the steady float height of a rotating disk to formulate and solve for the unsteady behavior of spin-down to rest. A similarity reduction of the Navier-Stokes equations reduces the problem to a coupled pair of partial differential equations in space and time. For a disk of fixed radius and density, the PDE's must be solved taking into account constraints imposed by the aerodynamic torque and aerodynamic lift. Thus the full solution for the unsteady azimuthal and axial dynamics of the disk can be obtained for given initial values of disk Reynolds number R = W h / ν and dimensionless disk rotation speed S =√{ 2} Ωh / W , where h is the float height, W is the fluid levitation velocity, Ω is the disk rotation rate, and ν is the kinematic viscosity of the fluid. Integrations reveal interesting families of solutions when plotted over steady solution curves in R- S parameter space and vindicate the quasi-steady spin-down theory reported in earlier work, valid only in a restricted region of parameter space.

  14. Demonstrating multibit magnetic memory in the Fe8 high-spin molecule by muon spin rotation

    Science.gov (United States)

    Shafir, Oren; Keren, Amit; Maegawa, Satoru; Ueda, Miki; Amato, Alex; Baines, Chris

    2005-09-01

    We develop a method to detect the quantum nature of high-spin molecules using muon spin rotation and a three-step field cycle ending always with the same field. We use this method to demonstrate that the Fe8 molecule can remember six (possibly eight) different histories (bits). A wide range of fields can be used to write a particular bit, and the information is stored in discrete states. Therefore, Fe8 can be used as a model compound for multibit magnetic memory. Our experiment also paves the way for magnetic quantum tunneling detection in films.

  15. Relativistic theory of nuclear spin-rotation tensor with kinetically balanced rotational London orbitals.

    Science.gov (United States)

    Xiao, Yunlong; Zhang, Yong; Liu, Wenjian

    2014-10-28

    Both kinetically balanced (KB) and kinetically unbalanced (KU) rotational London orbitals (RLO) are proposed to resolve the slow basis set convergence in relativistic calculations of nuclear spin-rotation (NSR) coupling tensors of molecules containing heavy elements [Y. Xiao and W. Liu, J. Chem. Phys. 138, 134104 (2013)]. While they perform rather similarly, the KB-RLO Ansatz is clearly preferred as it ensures the correct nonrelativistic limit even with a finite basis. Moreover, it gives rise to the same "direct relativistic mapping" between nuclear magnetic resonance shielding and NSR coupling tensors as that without using the London orbitals [Y. Xiao, Y. Zhang, and W. Liu, J. Chem. Theory Comput. 10, 600 (2014)].

  16. Hardy's argument and successive spin-s measurements

    International Nuclear Information System (INIS)

    Ahanj, Ali

    2010-01-01

    We consider a hidden-variable theoretic description of successive measurements of noncommuting spin observables on an input spin-s state. In this scenario, the hidden-variable theory leads to a Hardy-type argument that quantum predictions violate it. We show that the maximum probability of success of Hardy's argument in quantum theory is ((1/2)) 4s , which is more than in the spatial case.

  17. Slotted rotatable target assembly and systematic error analysis for a search for long range spin dependent interactions from exotic vector boson exchange using neutron spin rotation

    Science.gov (United States)

    Haddock, C.; Crawford, B.; Fox, W.; Francis, I.; Holley, A.; Magers, S.; Sarsour, M.; Snow, W. M.; Vanderwerp, J.

    2018-03-01

    We discuss the design and construction of a novel target array of nonmagnetic test masses used in a neutron polarimetry measurement made in search for new possible exotic spin dependent neutron-atominteractions of Nature at sub-mm length scales. This target was designed to accept and efficiently transmit a transversely polarized slow neutron beam through a series of long open parallel slots bounded by flat rectangular plates. These openings possessed equal atom density gradients normal to the slots from the flat test masses with dimensions optimized to achieve maximum sensitivity to an exotic spin-dependent interaction from vector boson exchanges with ranges in the mm - μm regime. The parallel slots were oriented differently in four quadrants that can be rotated about the neutron beam axis in discrete 90°increments using a Geneva drive. The spin rotation signals from the 4 quadrants were measured using a segmented neutron ion chamber to suppress possible systematic errors from stray magnetic fields in the target region. We discuss the per-neutron sensitivity of the target to the exotic interaction, the design constraints, the potential sources of systematic errors which could be present in this design, and our estimate of the achievable sensitivity using this method.

  18. Operation of the MAMI accelerator with a Wien filter based spin rotation system

    Energy Technology Data Exchange (ETDEWEB)

    Tioukine, V. [Institut fuer Kernphysik, Johannes-Gutenberg Universitaet Mainz, J.-J. Becherweg 45, D-55099 Mainz (Germany)]. E-mail: tioukine@kph.uni-mainz.de; Aulenbacher, K. [Institut fuer Kernphysik, Johannes-Gutenberg Universitaet Mainz, J.-J. Becherweg 45, D-55099 Mainz (Germany)

    2006-12-01

    A compact spin rotation system based on a Wien filter has been installed at the Mainz microtron accelerator (MAMI). Under operation with varying spin rotation angles a significant change of focal length together with a shift of the central beam trajectory is expected. We demonstrate that these effects can be kept under control. As a consequence operation with spin rotation angles between 0{sup o} and {+-}90{sup o} has been achieved without compromising the beam quality and operational stability of MAMI.

  19. Operation of the MAMI accelerator with a Wien filter based spin rotation system

    Science.gov (United States)

    Tioukine, V.; Aulenbacher, K.

    2006-12-01

    A compact spin rotation system based on a Wien filter has been installed at the Mainz microtron accelerator (MAMI). Under operation with varying spin rotation angles a significant change of focal length together with a shift of the central beam trajectory is expected. We demonstrate that these effects can be kept under control. As a consequence operation with spin rotation angles between 0° and ±90° has been achieved without compromising the beam quality and operational stability of MAMI.

  20. Experimental verification of the rotational type of chiral spin spiral structures by spin-polarized scanning tunneling microscopy.

    Science.gov (United States)

    Haze, Masahiro; Yoshida, Yasuo; Hasegawa, Yukio

    2017-10-16

    We report on experimental verification of the rotational type of chiral spin spirals in Mn thin films on a W(110) substrate using spin-polarized scanning tunneling microscopy (SP-STM) with a double-axis superconducting vector magnet. From SP-STM images using Fe-coated W tips magnetized to the out-of-plane and [001] directions, we found that both Mn mono- and double-layers exhibit cycloidal rotation whose spins rotate in the planes normal to the propagating directions. Our results agree with the theoretical prediction based on the symmetry of the system, supporting that the magnetic structures are driven by the interfacial Dzyaloshinskii-Moriya interaction.

  1. Predicting superdeformed rotational band-head spin in A ∼ 190 ...

    Indian Academy of Sciences (India)

    The band-head spin (0) of superdeformed (SD) rotational bands in ∼ 190 mass region is predicted using the variable moment of inertia (VMI) model for 66 SD rotational bands. The superdeformed rotational bands exhibited considerably good rotational property and rigid behaviour. The transition energies were ...

  2. SEG Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert; Laughlin, Darren; Brune, Bob

    2016-10-17

    Significant advancements in the development of sensors to enable rotational seismic measurements have been achieved. Prototypes are available now to support experiments that help validate the utility of rotational seismic measurements.

  3. A Probabilistic Model of Spin and Spin Measurements

    Science.gov (United States)

    Niehaus, Arend

    2016-01-01

    Several theoretical publications on the Dirac equation published during the last decades have shown that, an interpretation is possible, which ascribes the origin of electron spin and magnetic moment to an autonomous circular motion of the point-like charged particle around a fixed centre. In more recent publications an extension of the original so called "Zitterbewegung Interpretation" of quantum mechanics was suggested, in which the spin results from an average of instantaneous spin vectors over a Zitterbewegung period. We argue that, the corresponding autonomous motion of the electron should, if it is real, determine non-relativistic spin measurements. Such a direct connection with the established formal quantum mechanical description of spin measurements, into which spin is introduced as a "non-classical" quantity has, to our knowledge, not been reported. In the present work we show that, under certain "model assumptions" concerning the proposed autonomous motion, results of spin measurements, including measurements of angular correlations in singlet systems, can indeed be correctly described using classical probabilities. The success of the model is evidence for the "reality" of the assumed autonomous motion. The resulting model violates the Bell—inequalities to the same extent as quantum mechanics.

  4. FITTING HELICAL SNAKE AND ROTATOR FIELD STRENGTH MEASUREMENTS IN RHIC

    International Nuclear Information System (INIS)

    RANJBAR, V.; LUCCIO, A.U.; MACKAY, W.W.; TSOUPAS, N.

    2001-01-01

    We examined recent multi-pole measurements for the helical snakes and rotators in RHIC to generate a full field map. Since multi-pole measurements yield real field values for B, field components we developed a unique technique to evaluate the full fields using a traditional finite element analysis software [1]. From these measurements we employed SNIG [2] to generate orbit and Spin plots. From orbit values we generated a transfer matrix for the first snake

  5. SPARSE FARADAY ROTATION MEASURE SYNTHESIS

    International Nuclear Information System (INIS)

    Andrecut, M.; Stil, J. M.; Taylor, A. R.

    2012-01-01

    Faraday rotation measure synthesis is a method for analyzing multichannel polarized radio emissions, and it has emerged as an important tool in the study of Galactic and extragalactic magnetic fields. The method requires the recovery of the Faraday dispersion function from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we discuss a recovery method that assumes a sparse approximation of the Faraday dispersion function in an overcomplete dictionary of functions. We discuss the general case when both thin and thick components are included in the model, and we present the implementation of a greedy deconvolution algorithm. We illustrate the method with several numerical simulations that emphasize the effect of the covered range and sampling resolution in the Faraday depth space, and the effect of noise on the observed data.

  6. Spin current pumped by a rotating magnetic field in zigzag graphene nanoribbons

    International Nuclear Information System (INIS)

    Wang, J; Chan, K S

    2010-01-01

    We study electron spin resonance in zigzag graphene nanoribbons by applying a rotating magnetic field on the system without any bias. By using the nonequilibrium Green's function technique, the spin-resolved pumped current is explicitly derived in a rotating reference frame. The pumped spin current density increases with the system size and the intensity of the transverse rotating magnetic field. For graphene nanoribbons with an even number of zigzag chains, there is a nonzero pumped charge current in addition to the pumped spin current owing to the broken spatial inversion symmetry of the system, but its magnitude is much smaller than the spin current. The short-ranged static disorder from either impurities or defects in the ribbon can depress the spin current greatly due to the localization effect, whereas the long-ranged disorder from charge impurities can avoid inter-valley scattering so that the spin current can survive in the strong disorder for the single-energy mode.

  7. Spin noise measurement with diamagnetic atoms

    International Nuclear Information System (INIS)

    Takeuchi, M.; Ichihara, S.; Takano, T.; Kumakura, M.; Takahashi, Y.

    2007-01-01

    We report the measurement of the atomic spin noise of the diamagnetic atom ytterbium (Yb). Yb has various merits for utilizing the quantum nature of the atomic spin ensemble compared with the paramagnetic atoms used in all previous experiments. From the magnitude of the noise level and dependence on the detuning, we concluded that we succeeded in the measurement of 171 Yb atomic spin noise in an atomic beam

  8. Spinning like a blue straggler: the population of fast rotating blue straggler stars in ω Centauri

    Energy Technology Data Exchange (ETDEWEB)

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B. [Dipartimento di Fisica and Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Monaco, L. [European Southern Observatory, Casilla 19001, Santiago (Chile)

    2014-12-10

    By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities for 110 blue straggler stars (BSSs) in ω Centauri, the globular cluster-like stellar system harboring the largest known BSS population. According to their radial velocities, 109 BSSs are members of the system. The rotational velocity distribution is very broad, with the bulk of BSSs spinning at less than ∼40 km s{sup –1} (in agreement with the majority of such stars observed in other globular clusters) and a long tail reaching ∼200 km s{sup –1}. About 40% of the sample has v{sub e} sin i > 40 km s{sup –1} and about 20% has v{sub e} sin i > 70 km s{sup –1}. Such a large fraction is very similar to the percentage of fast rotating BSSs observed in M4. Thus, ω Centauri is the second stellar cluster, beyond M4, with a surprisingly high population of fast spinning BSSs. We found a hint of radial behavior for a fraction of fast rotating BSSs, with a mild peak within one core radius, and a possible rise in the external regions (beyond four core radii). This may suggest that recent formation episodes of mass transfer BSSs occurred preferentially in the outskirts of ω Centauri, or that braking mechanisms able to slow down these stars are least efficient in the lowest density environments.

  9. Selection and acquisition of data for the measurement of the spin rotation parameters in pion-proton scattering at high energies

    International Nuclear Information System (INIS)

    Raoul, Jean-Claude

    1971-01-01

    The experiment consists in measuring the polarisation of the recoil protons from elastic scattering of positive or negative pions on a polarised proton target (L. M. N.). The polarimeter consists in carbon plates alternated with wire spark chambers, The associated electronics has the following main functions: selective triggering of the spark chambers, acquisition and transcription on magnetic tape of all relevant information, continuous check of the various parts of the equipment. About one hundred scintillation counters provide information on the geometry of the pion-proton scattering. A fast logic treats these information. This logic, made of integrated circuits MECL, generates the selective trigger with a transit time of less than 150 ns, it reduces the triggering rate on background events by almost one order of magnitude. A small computer is used for acquisition and transcription of the data, and for the control of the experiment. (author) [fr

  10. Measuring Stellar Rotation Periods with Kepler

    DEFF Research Database (Denmark)

    Nielsen, M. B.; Gizon, L.; Schunker, H.

    2013-01-01

    We measure rotation periods for 12151 stars in the Kepler field, based on photometric variability caused by stellar activity. Our analysis returns stable rotation periods over at least six out of eight quarters of Kepler data. This large sample of stars enables us to study rotation periods...

  11. Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert [Applied Technology Associates, Albuquerque, NM (United States); Laughlin, Darren [Applied Technology Associates, Albuquerque, NM (United States); Brune, Robert [Applied Technology Associates, Albuquerque, NM (United States)

    2016-10-19

    Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is on induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.

  12. Magnetic pseudo-fields in a rotating electron-nuclear spin system

    Science.gov (United States)

    Wood, A. A.; Lilette, E.; Fein, Y. Y.; Perunicic, V. S.; Hollenberg, L. C. L.; Scholten, R. E.; Martin, A. M.

    2017-11-01

    Analogous to the precession of a Foucault pendulum observed on the rotating Earth, a precessing spin observed in a rotating frame of reference appears frequency-shifted. This can be understood as arising from a magnetic pseudo-field in the rotating frame that nevertheless has physically significant consequences, such as the Barnett effect. To detect these pseudo-fields, a rotating-frame sensor is required. Here we use quantum sensors, nitrogen-vacancy (NV) centres, in a rapidly rotating diamond to detect pseudo-fields in the rotating frame. Whereas conventional magnetic fields induce precession at a rate proportional to the gyromagnetic ratio, rotation shifts the precession of all spins equally, and thus primarily affect 13C nuclear spins in the sample. We are thus able to explore these effects via quantum sensing in a rapidly rotating frame, and define a new approach to quantum control using rotationally induced nuclear spin-selective magnetic fields. This work provides an integral step towards realizing precision rotation sensing and quantum spin gyroscopes.

  13. Computer calculation of the Van Vleck second moment for materials with internal rotation of spin groups

    Science.gov (United States)

    Goc, Roman

    2004-09-01

    This paper describes m2rc3, a program that calculates Van Vleck second moments for solids with internal rotation of molecules, ions or their structural parts. Only rotations about C 3 axes of symmetry are allowed, but up to 15 axes of rotation per crystallographic unit cell are permitted. The program is very useful in interpreting NMR measurements in solids. Program summaryTitle of the program: m2rc3 Catalogue number: ADUC Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUC Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland License provisions: none Computers: Cray SV1, Cray T3E-900, PCs Installation: Poznań Supercomputing and Networking Center ( http://www.man.poznan.pl/pcss/public/main/index.html) and Faculty of Physics, A. Mickiewicz University, Poznań, Poland ( http://www.amu.edu.pl/welcome.html.en) Operating system under which program has been tested: UNICOS ver. 10.0.0.6 on Cray SV1; UNICOS/mk on Cray T3E-900; Windows98 and Windows XP on PCs. Programming language: FORTRAN 90 No. of lines in distributed program, including test data, etc.: 757 No. of bytes in distributed program, including test data, etc.: 9730 Distribution format: tar.gz Nature of physical problem: The NMR second moment reflects the strength of the nuclear magnetic dipole-dipole interaction in solids. This value can be extracted from the appropriate experiment and can be calculated on the basis of Van Vleck formula. The internal rotation of molecules or their parts averages this interaction decreasing the measured value of the NMR second moment. The analysis of the internal dynamics based on the NMR second moment measurements is as follows. The second moment is measured at different temperatures. On the other hand it is also calculated for different models and frequencies of this motion. Comparison of experimental and calculated values permits the building of the most probable model of internal dynamics in the studied material. The program described

  14. Spin rotation function in a microscopic non-relativistic optical model

    International Nuclear Information System (INIS)

    Bauhoff, W.

    1984-01-01

    A microscopic optical potential, which is calculated non-relativistically with a density-dependent effective force, is used to calculate cross-section, polarization and spin-rotation function for elastic proton scattering from 40 Ca at 160 MeV and 497 MeV. At 160 MeV, the agreement to the data is comparable to phenomenological fits, and the spin-rotation can be used to distinguish between microscopic and Woods-Saxon potentials. A good fit to the spin-rotation function results at 497 MeV, whereas the polarization data are not well reproduced

  15. Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations.

    Science.gov (United States)

    Lee, Hyoung-In; Mok, Jinsik

    2014-01-01

    This study is motivated in part to better understand multiplexing in wireless communications, which employs photons carrying varying angular momenta. In particular, we examine both transverse electric (TE) and transverse magnetic (TM) waves in either co-rotations or counter-rotations. To this goal, we analyze both Poynting-vector flows and orbital and spin parts of the energy flow density for the combined fields. Consequently, we find not only enhancements but also cancellations between the two modes. To our surprise, the photon spins in the azimuthal direction exhibit a complete annihilation for the counter-rotational case even if the intensities of the colliding waves are of different magnitudes. In contrast, the orbital flow density disappears only if the two intensities satisfy a certain ratio. In addition, the concepts of spin sifters and enantiomer sorting are illustrated.

  16. Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations

    Directory of Open Access Journals (Sweden)

    Hyoung-In Lee

    2014-10-01

    Full Text Available This study is motivated in part to better understand multiplexing in wireless communications, which employs photons carrying varying angular momenta. In particular, we examine both transverse electric (TE and transverse magnetic (TM waves in either co-rotations or counter-rotations. To this goal, we analyze both Poynting-vector flows and orbital and spin parts of the energy flow density for the combined fields. Consequently, we find not only enhancements but also cancellations between the two modes. To our surprise, the photon spins in the azimuthal direction exhibit a complete annihilation for the counter-rotational case even if the intensities of the colliding waves are of different magnitudes. In contrast, the orbital flow density disappears only if the two intensities satisfy a certain ratio. In addition, the concepts of spin sifters and enantiomer sorting are illustrated.

  17. Rotational hysteresis measurements on alumite perpendicular media

    NARCIS (Netherlands)

    van Drent, W.P.; van Drent, W.P.; Sterringa, E.R.; Sterringa, E.R.; Lodder, J.C.; Bottoni, G.; Candolfo, D.; Cecchetti, A.; Masoli, F.

    1991-01-01

    Rotational hysteresis energy loss measurements have been performed to support the analysis of the magnetization processes of Fe- and Co-alumite perpendicular recording media. Two measurement techniques gave comparable results within error limits. The rotational hysteresis integral is severly lowered

  18. Spin Alignment and Collective Moment of Inertia of the Basic Rotational Band in the Cranking Model

    OpenAIRE

    Yoshihide, TANAKA; Department of Physics, Osaka City University

    1982-01-01

    By making an attempt to separate the intrinsic particle and collective rotational motions in the cranking model, the spin alignment and the collective moment of inertia characterizing the basic rotational bands are defined, and investigated by using a simple i_ shell model. The result of the calculation indicates that the collective moment of inertia decreases under the presence of the quasiparticles which are responsible for the increase of the spin alignment of the band.

  19. Torsionally mediated spin-rotation hyperfine splittings at moderate to high J values in methanol

    Science.gov (United States)

    Belov, S. P.; Golubiatnikov, G. Yu.; Lapinov, A. V.; Ilyushin, V. V.; Alekseev, E. A.; Mescheryakov, A. A.; Hougen, J. T.; Xu, Li-Hong

    2016-07-01

    This paper presents an explanation based on torsionally mediated proton-spin-overall-rotation interaction for the observation of doublet hyperfine splittings in some Lamb-dip sub-millimeter-wave transitions between ground-state torsion-rotation states of E symmetry in methanol. These unexpected doublet splittings, some as large as 70 kHz, were observed for rotational quantum numbers in the range of J = 13 to 34, and K = - 2 to +3. Because they increase nearly linearly with J for a given branch, we confined our search for an explanation to hyperfine operators containing one nuclear-spin angular momentum factor I and one overall-rotation angular momentum factor J (i.e., to spin-rotation operators) and ignored both spin-spin and spin-torsion operators, since they contain no rotational angular momentum operator. Furthermore, since traditional spin-rotation operators did not seem capable of explaining the observed splittings, we constructed totally symmetric "torsionally mediated spin-rotation operators" by multiplying the E-species spin-rotation operator by an E-species torsional-coordinate factor of the form e±niα. The resulting operator is capable of connecting the two components of a degenerate torsion-rotation E state. This has the effect of turning the hyperfine splitting pattern upside down for some nuclear-spin states, which leads to bottom-to-top and top-to-bottom hyperfine selection rules for some transitions, and thus to an explanation for the unexpectedly large observed hyperfine splittings. The constructed operator cannot contribute to hyperfine splittings in the A-species manifold because its matrix elements within the set of torsion-rotation A1 and A2 states are all zero. The theory developed here fits the observed large doublet splittings to a root-mean-square residual of less than 1 kHz and predicts unresolvable splittings for a number of transitions in which no doublet splitting was detected.

  20. Spinning Like a Blue Straggler: The Population of Fast Rotating Blue Straggler Stars in ω Centauri

    Science.gov (United States)

    Mucciarelli, A.; Lovisi, L.; Ferraro, F. R.; Dalessandro, E.; Lanzoni, B.; Monaco, L.

    2014-12-01

    By using high-resolution spectra acquired with FLAMES-GIRAFFE at the ESO/VLT, we measured the radial and rotational velocities for 110 blue straggler stars (BSSs) in ω Centauri, the globular cluster-like stellar system harboring the largest known BSS population. According to their radial velocities, 109 BSSs are members of the system. The rotational velocity distribution is very broad, with the bulk of BSSs spinning at less than ~40 km s-1 (in agreement with the majority of such stars observed in other globular clusters) and a long tail reaching ~200 km s-1. About 40% of the sample has ve sin i > 40 km s-1 and about 20% has ve sin i > 70 km s-1. Such a large fraction is very similar to the percentage of fast rotating BSSs observed in M4. Thus, ω Centauri is the second stellar cluster, beyond M4, with a surprisingly high population of fast spinning BSSs. We found a hint of radial behavior for a fraction of fast rotating BSSs, with a mild peak within one core radius, and a possible rise in the external regions (beyond four core radii). This may suggest that recent formation episodes of mass transfer BSSs occurred preferentially in the outskirts of ω Centauri, or that braking mechanisms able to slow down these stars are least efficient in the lowest density environments. Based on observations collected at the ESO-VLT under the programs 077.D-0696(A), 081.D-0356(A), and 089.D-0298(A).

  1. Torsionally mediated spin-rotation hyperfine splittings at moderate to high J values in methanol

    International Nuclear Information System (INIS)

    Belov, S. P.; Golubiatnikov, G. Yu.; Lapinov, A. V.; Ilyushin, V. V.; Mescheryakov, A. A.; Alekseev, E. A.; Hougen, J. T.; Xu, Li-Hong

    2016-01-01

    This paper presents an explanation based on torsionally mediated proton-spin–overall-rotation interaction for the observation of doublet hyperfine splittings in some Lamb-dip sub-millimeter-wave transitions between ground-state torsion-rotation states of E symmetry in methanol. These unexpected doublet splittings, some as large as 70 kHz, were observed for rotational quantum numbers in the range of J = 13 to 34, and K = − 2 to +3. Because they increase nearly linearly with J for a given branch, we confined our search for an explanation to hyperfine operators containing one nuclear-spin angular momentum factor I and one overall-rotation angular momentum factor J (i.e., to spin-rotation operators) and ignored both spin-spin and spin-torsion operators, since they contain no rotational angular momentum operator. Furthermore, since traditional spin-rotation operators did not seem capable of explaining the observed splittings, we constructed totally symmetric “torsionally mediated spin-rotation operators” by multiplying the E-species spin-rotation operator by an E-species torsional-coordinate factor of the form e ±niα . The resulting operator is capable of connecting the two components of a degenerate torsion-rotation E state. This has the effect of turning the hyperfine splitting pattern upside down for some nuclear-spin states, which leads to bottom-to-top and top-to-bottom hyperfine selection rules for some transitions, and thus to an explanation for the unexpectedly large observed hyperfine splittings. The constructed operator cannot contribute to hyperfine splittings in the A-species manifold because its matrix elements within the set of torsion-rotation A 1 and A 2 states are all zero. The theory developed here fits the observed large doublet splittings to a root-mean-square residual of less than 1 kHz and predicts unresolvable splittings for a number of transitions in which no doublet splitting was detected.

  2. Efficient calculation of nuclear spin-rotation constants from auxiliary density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Gutierrez, Bernardo, E-mail: bzuniga.51@gmail.com [Departamento de Ciencias Computacionales, Universidad de Guadalajara, Blvd. Marcelino García Barragán 1421, C.P. 44430 Guadalajara, Jalisco (Mexico); Camacho-Gonzalez, Monica [Universidad Tecnológica de Tecámac, División A2, Procesos Industriales, Carretera Federal México Pachuca Km 37.5, Col. Sierra Hermosa, C.P. 55740 Tecámac, Estado de México (Mexico); Bendana-Castillo, Alfonso [Universidad Tecnológica de Tecámac, División A3, Tecnologías de la Información y Comunicaciones, Carretera Federal México Pachuca Km 37.5, Col. Sierra Hermosa, C.P. 55740 Tecámac, Estado de México (Mexico); Simon-Bastida, Patricia [Universidad Tecnlógica de Tulancingo, División Electromecánica, Camino a Ahuehuetitla No. 301, Col. Las Presas, C.P. 43642 Tulancingo, Hidalgo (Mexico); Calaminici, Patrizia; Köster, Andreas M. [Departamento de Química, CINVESTAV, Avenida Instituto Politécnico Nacional 2508, A.P. 14-740, México D.F. 07000 (Mexico)

    2015-09-14

    The computation of the spin-rotation tensor within the framework of auxiliary density functional theory (ADFT) in combination with the gauge including atomic orbital (GIAO) scheme, to treat the gauge origin problem, is presented. For the spin-rotation tensor, the calculation of the magnetic shielding tensor represents the most demanding computational task. Employing the ADFT-GIAO methodology, the central processing unit time for the magnetic shielding tensor calculation can be dramatically reduced. In this work, the quality of spin-rotation constants obtained with the ADFT-GIAO methodology is compared with available experimental data as well as with other theoretical results at the Hartree-Fock and coupled-cluster level of theory. It is found that the agreement between the ADFT-GIAO results and the experiment is good and very similar to the ones obtained by the coupled-cluster single-doubles-perturbative triples-GIAO methodology. With the improved computational performance achieved, the computation of the spin-rotation tensors of large systems or along Born-Oppenheimer molecular dynamics trajectories becomes feasible in reasonable times. Three models of carbon fullerenes containing hundreds of atoms and thousands of basis functions are used for benchmarking the performance. Furthermore, a theoretical study of temperature effects on the structure and spin-rotation tensor of the H{sup 12}C–{sup 12}CH–DF complex is presented. Here, the temperature dependency of the spin-rotation tensor of the fluorine nucleus can be used to identify experimentally the so far unknown bent isomer of this complex. To the best of our knowledge this is the first time that temperature effects on the spin-rotation tensor are investigated.

  3. Real-space observation of a right-rotating inhomogeneous cycloidal spin spiral by spin-polarized scanning tunneling microscopy in a triple axes vector magnet.

    Science.gov (United States)

    Meckler, S; Mikuszeit, N; Pressler, A; Vedmedenko, E Y; Pietzsch, O; Wiesendanger, R

    2009-10-09

    Using spin-polarized scanning tunneling microscopy performed in a triple axes vector magnet, we show that the magnetic structure of the Fe double layer on W(110) is an inhomogeneous right-rotating cycloidal spin spiral. The magnitude of the Dzyaloshinskii-Moriya vector is extracted from the experimental data using micromagnetic calculations. The result is confirmed by comparison of the measured saturation field along the easy axis to the respective value as obtained from Monte Carlo simulations. We find that the Dzyaloshinskii-Moriya interaction is too weak to destabilize the single domain state. However, it can define the sense of rotation and the cycloidal spiral type once the single domain state is destabilized by dipolar interaction.

  4. Spin imaging in solids using synchronously rotating field gradients and samples

    International Nuclear Information System (INIS)

    Wind, R.A.; Yannoni, C.S.

    1983-01-01

    A method for spin-imaging in solids using nuclear magnetic resonance (NMR) spectroscopy is described. With this method, the spin density distribution of a two- or three-dimensional object such as a solid can be constructed resulting in an image of the sample. This method lends itself to computer control to map out an image of the object. This spin-imaging method involves the steps of placing a solid sample in the rf coil field and the external magnetic field of an NMR spectrometer. A magnetic field gradient is superimposed across the sample to provide a field gradient which results in a varying DC field that has different values over different parts of the sample. As a result, nuclei in different parts of the sample have different resonant NMR frequencies. The sample is rotated about an axis which makes a particular angle of 54.7 degrees with the static external magnetic field. The magnetic field gradient which has a spatial distribution related to the sample spinning axis is then rotated synchronously with the sample. Data is then collected while performing a solid state NMR line narrowing procedure. The next step is to change the phase relation between the sample rotation and the field gradient rotation. The data is again collected as before while the sample and field gradient are synchronously rotated. The phase relation is changed a number of times and data collected each time. The spin image of the solid sample is then reconstructed from the collected data

  5. Demonstrating Multi-bit Magnetic Memory in the Fe8 High Spin Molecule by Muon Spin Rotation

    OpenAIRE

    Shafir, Oren; Keren, Amit; Maegawa, Satoru; Ueda, Miki; Amato, Alex; Baines, Chris

    2005-01-01

    We developed a method to detect the quantum nature of high spin molecules using muon spin rotation, and a three-step field cycle ending always with the same field. We use this method to demonstrate that the Fe8 molecule can remember 6 (possibly 8) different histories (bits). A wide range of fields can be used to write a particular bit, and the information is stored in discrete states. Therefore, Fe8 can be used as a model compound for Multi-bit Magnetic Memory. Our experiment also paves the w...

  6. Deconvolving Current from Faraday Rotation Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Stephen E. Mitchell

    2008-02-01

    In this paper, a unique software program is reported which automatically decodes the Faraday rotation signal into a time-dependent current representation. System parameters, such as the Faraday fiber’s Verdet constant and number of loops in the sensor, are the only user-interface inputs. The central aspect of the algorithm utilizes a short-time Fourier transform, which reveals much of the Faraday rotation measurement’s implicit information necessary for unfolding the dynamic current measurement.

  7. Spin, quadrupole moment, and deformation of the magnetic-rotational band head in Pb193

    Science.gov (United States)

    Balabanski, D. L.; Ionescu-Bujor, M.; Iordachescu, A.; Bazzacco, D.; Brandolini, F.; Bucurescu, D.; Chmel, S.; Danchev, M.; de Poli, M.; Georgiev, G.; Haas, H.; Hübel, H.; Marginean, N.; Menegazzo, R.; Neyens, G.; Pavan, P.; Rossi Alvarez, C.; Ur, C. A.; Vyvey, K.; Frauendorf, S.

    2011-01-01

    The spectroscopic quadrupole moment of the T1/2=9.4(5) ns isomer in Pb193 at an excitation energy Eex=(2585+x) keV is measured by the time-differential perturbed angular distribution method as |Qs|=2.6(3) e b. Spin and parity Iπ=27/2- are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the 1i13/2 subshell with the (3s1/2-21h9/21i13/2)11- proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation ɛ2=-0.11, similar to that of the 11-proton intruder states, which nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

  8. Spin, quadrupole moment, and deformation of the magnetic-rotational band head in (193)Pb

    CERN Document Server

    Balabanski, D L; Iordachescu, A; Bazzacco, D; Brandolini, F; Bucurescu, D; Chmel, S; Danchev, M; De Poli, M; Georgiev, G; Haas, H; Hubel, H; Marginean, N; Menegazzo, R; Neyens, G; Pavan, P; Rossi Alvarez, C; Ur, C A; Vyvey, K; Frauendorf, S

    2011-01-01

    The spectroscopic quadrupole moment of the T(1/2) = 9.4(5) ns isomer in (193)Pb at an excitation energy E(ex) = (2585 + x) keV is measured by the time-differential perturbed angular distribution method as vertical bar Q(s)vertical bar = 2.6(3) e b. Spin and parity I(pi) = 27/2(-) are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the coupling of a neutron hole in the 1i(13/2) subshell with the (3s(1/2)(-2)1h(9/2)1i(13/2))(11-) proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation epsilon(2) = -0.11, similar to that of the 11(-)proton intruder states, which occur in the even-even Pb nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

  9. New Results on Spin Rotation Parameter A in the πp-elastic Scattering in the Resonance Region

    Science.gov (United States)

    Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Svirida, D. N.; Sulimov, A. D.; Zhurkin, V. V.; Beloglazov, Yu. A.; Kovalev, A. I.; Kruglov, S. P.; Novinsky, D. V.; Shchedrov, V. A.; Sumachev, V. V.; Trautman, V. Yu.; Bazhanov, N. A.; Bunyatova, E. I.

    2003-07-01

    The paper presents new experimental data on the spin rotation parameter A obtained recently by ITEP-PNPI collaboration at the ITEP accelerator. The set of measurements was performed in carefully chosen critical points with precision sufficient for choosing the correct branches of partial wave analyses. The data for both π+ and π--scattering at 1.0, 1.43 and 1.62 GeV/c is included.

  10. Application of magnetic resonance force microscopy cyclic adiabatic inversion for a single-spin measurement

    CERN Document Server

    Berman, G P; Chapline, G; Gurvitz, S A; Hammel, P C; Pelekhov, D V; Suter, A; Tsifrinovich, V I

    2003-01-01

    We consider the process of a single-spin measurement using magnetic resonance force microscopy (MRFM) with a cyclic adiabatic inversion (CAI). This technique is also important for different applications, including a measurement of a qubit state in quantum computation. The measurement takes place through the interaction of a single spin with a cantilever modelled by a quantum oscillator in a coherent state in a quasi-classical range of parameters. The entire system is treated rigorously within the framework of the Schroedinger equation. For a many-spin system our equations accurately describe conventional MRFM experiments involving CAI of the spin system. Our computer simulations of the quantum spin-cantilever dynamics show that the probability distribution for the cantilever position develops two asymmetric peaks with the total relative probabilities mainly dependent on the initial angle between the directions of the average spin and the effective magnetic field, in the rotating frame. We show that each of th...

  11. Muon spin rotation study of the topological superconductor SrxBi2Se3

    Science.gov (United States)

    Leng, H.; Cherian, D.; Huang, Y. K.; Orain, J.-C.; Amato, A.; de Visser, A.

    2018-02-01

    We report transverse-field (TF) muon spin rotation experiments on single crystals of the topological superconductor SrxBi2Se3 with nominal concentrations x =0.15 and 0.18 (Tc˜3 K). The TF spectra (B =10 mT), measured after cooling to below Tc in field, did not show any additional damping of the muon precession signal due to the flux line lattice within the experimental uncertainty. This puts a lower bound on the magnetic penetration depth λ ≥2.3 μ m . However, when we induce disorder in the vortex lattice by changing the magnetic field below Tc, a sizable damping rate is obtained for T →0 . The data provide microscopic evidence for a superconducting volume fraction of ˜70 % in the x =0.18 crystal and thus bulk superconductivity.

  12. Spin rotation in alpha-Fe2O3 nanoparticles by interparticle interactions

    DEFF Research Database (Denmark)

    Frandsen, Cathrine; Mørup, Steen

    2005-01-01

    degrees out of plane, depending on the particle size. The spin rotation can be explained by exchange interaction between neighboring particles with nonparallel (001) planes. The results imply that interparticle interactions can lead to spin directions deviating from the easy axis defined by the magnetic......Nanoparticles of alpha-Fe2O3 (hematite) typically have the sublattice magnetization directions in the hexagonal (001) plane below the Neel temperature. By use of Mossbauer spectroscopy we have found that for agglomerated particles the sublattice magnetization may be rotated of the order of 15...

  13. Distinguishing between coherent magnetization rotation and generation of incoherent spin waves in a spin-transfer effect experiment

    Science.gov (United States)

    Bazaliy, Yaroslaw; Jones, Barbara

    2002-03-01

    Electric current flowing from one metallic ferromagnet to another induces an interaction between them [1,2]. This interaction is qualitatively different from the one observed in equilibrium and creates a so-called ``spin-transfer'' torque - a subject of recent interest in the field of spintronics. Technologically spin-transfer effect is very interesting due to its possible usefulness for the memory writing process based on ``current induced switching" in metallic magnetic structures. Physics of spin-transfer torque involves interesting issues of spin-injection, spin-accumulation and excitation of different types of magnetic modes in the ferromagnets. The result of spin-transfer torque action depends on which magnetic mode is most easily excited by the spin-polarized current. Currently there are two views on the nature of this mode. In one approach [1] it is assumed that a coherent rotation of magnetization is induced and in the other [2,3] - that incoherent spin waves are generated. While in a real experiment both modes are probably excited at the same time, intuitively it seems natural that coherent rotation is more likely to happen when the angle between injected spins and magnetization is large. On the contrary in a collinear case spin-wave generation is more likely to happen. In the experiments done so far [4] the effect of spin-transfer torque was studied in the collinear setup. In [5] we applied the general approach of Ref.1 to this experiment and were able to give exact predictions for the particular magnetic anisotropy of the experiment [4]. While those predictions do not completely agree with the experimental results, a theory based on spin-wave generation [6] also seems to be ruled out by [4]. Here we propose a relatively easy modification of experiment [4] in which the spin-polarization of incoming current is no longer collinear with magnetization and recalculate the switching behavior of the device. We expect that a better agreement with experiment will

  14. Human-brain ferritin studied by muon spin rotation: a pilot study.

    Science.gov (United States)

    Bossoni, Lucia; Grand Moursel, Laure; Bulk, Marjolein; Simon, Brecht G; Webb, Andrew; van der Weerd, Louise; Huber, Martina; Carretta, Pietro; Lascialfari, Alessandro; Oosterkamp, Tjerk H

    2017-10-18

    Muon spin rotation is employed to investigate the spin dynamics of ferritin proteins isolated from the brain of an Alzheimer's disease (AD) patient and of a healthy control, using a sample of horse-spleen ferritin as a reference. A model based on the Néel theory of superparamagnetism is developed in order to interpret the spin relaxation rate of the muons stopped by the core of the protein. Using this model, our preliminary observations show that ferritins from the healthy control are filled with a mineral compatible with ferrihydrite, while ferritins from the AD patient contain a crystalline phase with a larger magnetocrystalline anisotropy, possibly compatible with magnetite or maghemite.

  15. Probing the flexibility of internal rotation in silylated phenols with the NMR scalar spin-spin coupling constants.

    Science.gov (United States)

    Sychrovský, Vladimír; Benda, Ladislav; Prokop, Alexandr; Blechta, Vratislav; Schraml, Jan; Spirko, Vladimír

    2008-06-12

    The rotation of a trimethylsiloxy (TMSO) group in three silylated phenols (with three different ortho substituents -H, -CH3, and -C(CH3)3) was studied with the NMR (n)J(Si,C), n = 2, 3, 4, 5, scalar spin-spin coupling between the (29)Si nucleus of the TMSO group and the (13)C nuclei of the phenyl ring. The internal rotation potential calculated with the B3LYP and MP2 calculation methods including the effect of a solvent environment (gas phase, chloroform, and water) was used for the calculation of the dynamical averages of the scalar coupling constants in the framework of the rigid-bender formalism. Solvent effects, the quality of the rotational potential, and the applicability of the classical molecular dynamic to the problem is discussed. Quantum effects have a sizable impact on scalar couplings, particularly for the internal rotational states well localized within the wells of the potential surfaces for the TMSO group. The overall difference between the experimental and theoretical scalar couplings calculated for the global energy-minima structures (static model) decreases substantially for both model potentials (B3LYP, MP2) when the molecular motion of the TMSO group is taken into account. The calculated data indicate that the inclusion of molecular motion is necessary for the accurate calculation of the scalar coupling constants and their reliable structural interpretation for any system which possesses a large-amplitude motion.

  16. Faraday Rotation and L Band Oceanographic Measurements

    DEFF Research Database (Denmark)

    Skou, Niels

    2003-01-01

    Spaceborne radiometric measurements of the L band brightness temperature over the oceans make it possible to estimate sea surface salinity. However, Faraday rotation in the ionosphere disturbs the signals and must be corrected. Two different ways of assessing the disturbance directly from...

  17. The new conceptual design of snakes and spin rotators in RHIC

    International Nuclear Information System (INIS)

    Lee, S.Y.; Courant, E.D.

    1990-01-01

    We discuss the generalized snake configurations, which offers either the advantages of shorter total snake length and smaller horizontal orbit displacement in the compact configuration or the dual functions of a snake and a 90 degree spin rotation for the helicity state. The generalized snake is then applied to the polarized proton collision in RHIC. The possible schemes of obtaining high luminosity are discussed

  18. Measurement of rotational temperature at Kolhapur, India

    Directory of Open Access Journals (Sweden)

    G. K. Mukherjee

    2004-09-01

    Full Text Available Measurements of the hydroxyl rotational temperature for the (8,3 Meinel band have been reported from the observations of the ratio of the relative intensities of P1(2 and P1(4 lines of the OH(8,3 band at Kolhapur (16.8° N, 74.2° E, dip lat. 10.6° N in India during the period 1 November 2002-29 April 2003 using tilting-filter photometers. Mean values of rotational temperature have been computed for 60 nights. The monthly mean value of temperature lies in the range 194(±11-208(±18K. The mean rotational temperature obtained from all the measurements was found to be 202±15K. The results agree with other low-latitude measurements of rotational temperature using photometric airglow techniques. Quasi-periodic fluctuations with a period of about one to two hours have been prominent on many nights. Furthermore, the results show the general agreement between observations and model (MSIS-86 predictions.

  19. Measurement of rotational temperature at Kolhapur, India

    Directory of Open Access Journals (Sweden)

    G. K. Mukherjee

    2004-09-01

    Full Text Available Measurements of the hydroxyl rotational temperature for the (8,3 Meinel band have been reported from the observations of the ratio of the relative intensities of P1(2 and P1(4 lines of the OH(8,3 band at Kolhapur (16.8° N, 74.2° E, dip lat. 10.6° N in India during the period 1 November 2002-29 April 2003 using tilting-filter photometers. Mean values of rotational temperature have been computed for 60 nights. The monthly mean value of temperature lies in the range 194(±11-208(±18K. The mean rotational temperature obtained from all the measurements was found to be 202±15K. The results agree with other low-latitude measurements of rotational temperature using photometric airglow techniques. Quasi-periodic fluctuations with a period of about one to two hours have been prominent on many nights. Furthermore, the results show the general agreement between observations and model (MSIS-86 predictions.

  20. Measuring the spins of accreting black holes

    International Nuclear Information System (INIS)

    McClintock, Jeffrey E; Narayan, Ramesh; Gou, Lijun; Kulkarni, Akshay; Penna, Robert F; Steiner, James F; Davis, Shane W; Orosz, Jerome A; Remillard, Ronald A

    2011-01-01

    A typical galaxy is thought to contain tens of millions of stellar-mass black holes, the collapsed remnants of once massive stars, and a single nuclear supermassive black hole. Both classes of black holes accrete gas from their environments. The accreting gas forms a flattened orbiting structure known as an accretion disk. During the past several years, it has become possible to obtain measurements of the spins of the two classes of black holes by modeling the x-ray emission from their accretion disks. Two methods are employed, both of which depend upon identifying the inner radius of the accretion disk with the innermost stable circular orbit, whose radius depends only on the mass and spin of the black hole. In the Fe Kα method, which applies to both classes of black holes, one models the profile of the relativistically broadened iron line with a special focus on the gravitationally redshifted red wing of the line. In the continuum-fitting (CF) method, which has so far only been applied to stellar-mass black holes, one models the thermal x-ray continuum spectrum of the accretion disk. We discuss both methods, with a strong emphasis on the CF method and its application to stellar-mass black holes. Spin results for eight stellar-mass black holes are summarized. These data are used to argue that the high spins of at least some of these black holes are natal, and that the presence or absence of relativistic jets in accreting black holes is not entirely determined by the spin of the black hole.

  1. Polarisation in spin-echo experiments: Multi-point and lock-in measurements

    Science.gov (United States)

    Tamtögl, Anton; Davey, Benjamin; Ward, David J.; Jardine, Andrew P.; Ellis, John; Allison, William

    2018-02-01

    Spin-echo instruments are typically used to measure diffusive processes and the dynamics and motion in samples on ps and ns time scales. A key aspect of the spin-echo technique is to determine the polarisation of a particle beam. We present two methods for measuring the spin polarisation in spin-echo experiments. The current method in use is based on taking a number of discrete readings. The implementation of a new method involves continuously rotating the spin and measuring its polarisation after being scattered from the sample. A control system running on a microcontroller is used to perform the spin rotation and to calculate the polarisation of the scattered beam based on a lock-in amplifier. First experimental tests of the method on a helium spin-echo spectrometer show that it is clearly working and that it has advantages over the discrete approach, i.e., it can track changes of the beam properties throughout the experiment. Moreover, we show that real-time numerical simulations can perfectly describe a complex experiment and can be easily used to develop improved experimental methods prior to a first hardware implementation.

  2. Pulsar spin-down: the glitch-dominated rotation of PSR J0537-6910

    Science.gov (United States)

    Antonopoulou, D.; Espinoza, C. M.; Kuiper, L.; Andersson, N.

    2018-01-01

    The young, fast-spinning X-ray pulsar J0537-6910 displays an extreme glitch activity, with large spin-ups interrupting its decelerating rotation every ∼100 d. We present nearly 13 yr of timing data from this pulsar, obtained with the Rossi X-ray Timing Explorer. We discovered 22 new glitches and performed a consistent analysis of all 45 glitches detected in the complete data span. Our results corroborate the previously reported strong correlation between glitch spin-up size and the time to the next glitch, a relation that has not been observed so far in any other pulsar. The spin evolution is dominated by the glitches, which occur at a rate of ∼3.5 per year, and the post-glitch recoveries, which prevail the entire interglitch intervals. This distinctive behaviour provides invaluable insights into the physics of glitches. The observations can be explained with a multicomponent model that accounts for the dynamics of the neutron superfluid present in the crust and core of neutron stars. We place limits on the moment of inertia of the component responsible for the spin-up and, ignoring differential rotation, the velocity difference it can sustain with the crust. Contrary to its rapid decrease between glitches, the spin-down rate increased over the 13 yr, and we find the long-term braking index nl = -1.22(4), the only negative braking index seen in a young pulsar. We briefly discuss the plausible interpretations of this result, which is in stark contrast to the predictions of standard models of pulsar spin-down.

  3. Strong coupling between a single nitrogen-vacancy spin and the rotational mode of diamonds levitating in an ion trap

    Science.gov (United States)

    Delord, T.; Nicolas, L.; Chassagneux, Y.; Hétet, G.

    2017-12-01

    A scheme for strong coupling between a single atomic spin and the rotational mode of levitating nanoparticles is proposed. The idea is based on spin readout of nitrogen-vacancy centers embedded in aspherical nanodiamonds levitating in an ion trap. We show that the asymmetry of the diamond induces a rotational confinement in the ion trap. Using a weak homogeneous magnetic field and a strong microwave driving we then demonstrate that the spin of the nitrogen-vacancy center can be strongly coupled to the rotational mode of the diamond.

  4. High-spin level systematics in /sup 186-194/Pt and rotation-alignment coupling

    International Nuclear Information System (INIS)

    Piiparinen, M.; Cunnane, J.C.; Daly, P.J.; Dors, C.L.; Bernthal, F.M.; Khoo, T.L.

    1975-01-01

    Systematic investigations of the shape-transitional nuclei 186 Pt to 194 Pt by (α,xny) reactions have revealed a rich variety of high-spin structural phenomena, which can be qualitatively understood in terms of rotation-alignment coupling and the interplay between collective and single-particle excitation modes. Acute backbending in the positive-parity yrast sequences of 188 , 190 , 192 , 194 Pt is attributed to the intersection of rotation-aligned (νi 13 / 2 -2 ) and (πh 11 / 2 -2 ) bands with the ground bands

  5. Coupling between magnetic field and curvature in Heisenberg spins on surfaces with rotational symmetry

    International Nuclear Information System (INIS)

    Carvalho-Santos, Vagson L.; Dandoloff, Rossen

    2012-01-01

    We study the nonlinear σ-model in an external magnetic field applied on curved surfaces with rotational symmetry. The Euler–Lagrange equations derived from the Hamiltonian yield the double sine-Gordon equation (DSG) provided the magnetic field is tuned with the curvature of the surface. A 2π skyrmion appears like a solution for this model and surface deformations are predicted at the sector where the spins point in the opposite direction to the magnetic field. We also study some specific examples by applying the model on three rotationally symmetric surfaces: the cylinder, the catenoid and the hyperboloid.

  6. Nuclear spin optical rotation and Faraday effect in gaseous and liquid water.

    Science.gov (United States)

    Pennanen, Teemu S; Ikäläinen, Suvi; Lantto, Perttu; Vaara, Juha

    2012-05-14

    Nuclear spin optical rotation (NSOR) of linearly polarized light, due to the nuclear spins through the Faraday effect, provides a novel probe of molecular structure and could pave the way to optical detection of nuclear magnetization. We determine computationally the effects of the liquid medium on NSOR and the Verdet constant of Faraday rotation (arising from an external magnetic field) in water, using the recently developed theory applied on a first-principles molecular dynamics trajectory. The gas-to-liquid shifts of the relevant antisymmetric polarizability and, hence, NSOR magnitude are found to be -14% and -29% for (1)H and (17)O nuclei, respectively. On the other hand, medium effects both enhance the local electric field in water and, via bulk magnetization, the local magnetic field. Together these two effects partially cancel the solvation influence on the single-molecular property. We find a good agreement for the hydrogen NSOR with a recent pioneering experiment on H(2)O(l).

  7. Dynamical measurements of the Spin Hall angle

    OpenAIRE

    Talalaevskyy, Oleksandr

    2017-01-01

    Broad study of magnetic properties of YIG films is performed. This thesis covers the whole path from YIG sample growth to characterization of magnetization dynamics. In the sub-chapter 5.1, full magnetic characterization of the thin sputtered YIG films is given. A batch of YIG samples with thicknesses of 19, 29, 38 and 49 nanometer is grown by magnetron sputtering for the spin waves experiment. The thickness and the surface roughness are controlled by XRR and AFM measurements. The obtained sa...

  8. Measuring slepton spin at the LHC

    CERN Document Server

    INSPIRE-00064725

    2006-01-01

    A new method is presented for measuring the spin of selectrons and smuons at the Large Hadron Collider (LHC), using an angular variable which is sensitive to the polar angle in direct slepton pair production. This variable is invariant under boosts along the beam axis, so it can be used at the LHC despite the fact that the longitudinal boost of the centre-of-mass frame cannot be determined. Monte Carlo simulations demonstrate that, using this method, the LHC can distinguish between the supersymmetric production angular distribution and phase space, or between supersymmetry and the production angular distribution of universal extra dimensions. An integrated luminosity of about 100 to 300 inverse fb provides sufficient statistics to measure the slepton spin for points which had left-handed slepton masses in the range 202 to 338 GeV, and right-handed sleptons in the range 143 to 252 GeV. Good sensitivity was found in the `bulk' and `stau co-annihilation' regions of the cMSSM favoured by cosmological relic densit...

  9. Nanoscale Measurements of Magnetism & Spin Coherence in Semiconductors

    Science.gov (United States)

    2015-12-17

    Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 spin polarized measurements, single spins, single spin manipulation REPORT DOCUMENTATION...Received Paper 6.00 Ali Yazdani. Visualizing Majorana fermions in a chain of magnetic atoms on a superconductor, Nobel Symposium 156, New forms of...level and also for the first time probe spin orbit coupling. This system led to first direct visualization of a Majorana fermion in a condensed

  10. Phase measurement for driven spin oscillations in a storage ring

    Science.gov (United States)

    Hempelmann, N.; Hejny, V.; Pretz, J.; Soltner, H.; Augustyniak, W.; Bagdasarian, Z.; Bai, M.; Barion, L.; Berz, M.; Chekmenev, S.; Ciullo, G.; Dymov, S.; Eversmann, D.; Gaisser, M.; Gebel, R.; Grigoryev, K.; Grzonka, D.; Guidoboni, G.; Heberling, D.; Hetzel, J.; Hinder, F.; Kacharava, A.; Kamerdzhiev, V.; Keshelashvili, I.; Koop, I.; Kulikov, A.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Lorentz, B.; Maanen, P.; Macharashvili, G.; Magiera, A.; Mchedlishvili, D.; Mey, S.; Müller, F.; Nass, A.; Nikolaev, N. N.; Nioradze, M.; Pesce, A.; Prasuhn, D.; Rathmann, F.; Rosenthal, M.; Saleev, A.; Schmidt, V.; Semertzidis, Y.; Senichev, Y.; Shmakova, V.; Silenko, A.; Slim, J.; Stahl, A.; Stassen, R.; Stephenson, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Talman, R.; Thörngren Engblom, P.; Trinkel, F.; Uzikov, Yu.; Valdau, Yu.; Valetov, E.; Vassiliev, A.; Weidemann, C.; Wrońska, A.; Wüstner, P.; Zuprański, P.; Żurek, M.; JEDI Collaboration

    2018-04-01

    This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV /c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles.

  11. Application of magnetic resonance force microscopy cyclic adiabatic inversion for a single-spin measurement

    International Nuclear Information System (INIS)

    Berman, G P; Borgonovi, F; Chapline, G; Gurvitz, S A; Hammel, P C; Pelekhov, D V; Suter, A; Tsifrinovich, V I

    2003-01-01

    We consider the process of a single-spin measurement using magnetic resonance force microscopy (MRFM) with a cyclic adiabatic inversion (CAI). This technique is also important for different applications, including a measurement of a qubit state in quantum computation. The measurement takes place through the interaction of a single spin with a cantilever modelled by a quantum oscillator in a coherent state in a quasi-classical range of parameters. The entire system is treated rigorously within the framework of the Schroedinger equation. For a many-spin system our equations accurately describe conventional MRFM experiments involving CAI of the spin system. Our computer simulations of the quantum spin-cantilever dynamics show that the probability distribution for the cantilever position develops two asymmetric peaks with the total relative probabilities mainly dependent on the initial angle between the directions of the average spin and the effective magnetic field, in the rotating frame. We show that each of the peaks is correlated with the direction of the average spin (being along or opposite to the direction of the effective magnetic field). This generates two possible outcomes of a single-spin measurement, similar to the Stern-Gerlach effect. We demonstrate that the generation of the second peak can be significantly suppressed by turning on adiabatically the amplitude of the rf magnetic field. We also show that MRFM CAI can be used both for detecting a signal from a single spin, and for measuring the single-spin state by measuring the phase of the cantilever driving oscillations

  12. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    OpenAIRE

    Luo Jun; Wang Zhiqian; Shen Chengwu; Wen Zhuoman; Liu Shaojin; Cai Sheng; Li Jianrong

    2015-01-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendic...

  13. A High-Spin Rate Measurement Method for Projectiles Using a Magnetoresistive Sensor Based on Time-Frequency Domain Analysis.

    Science.gov (United States)

    Shang, Jianyu; Deng, Zhihong; Fu, Mengyin; Wang, Shunting

    2016-06-16

    Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin rate, which has long been regarded as a daunting task, is the basis of precise guidance and control. Magnetoresistive (MR) sensors can be applied to spin rate measurement, especially in the high-spin and high-g projectile launch environment. In this paper, based on the theory of a MR sensor measuring spin rate, the mathematical relationship model between the frequency of MR sensor output and projectile spin rate was established through a fundamental derivation. By analyzing the characteristics of MR sensor output whose frequency varies with time, this paper proposed the Chirp z-Transform (CZT) time-frequency (TF) domain analysis method based on the rolling window of a Blackman window function (BCZT) which can accurately extract the projectile spin rate. To put it into practice, BCZT was applied to measure the spin rate of 155 mm artillery projectile. After extracting the spin rate, the impact that launch rotational angular velocity and aspect angle have on the extraction accuracy of the spin rate was analyzed. Simulation results show that the BCZT TF domain analysis method can effectively and accurately measure the projectile spin rate, especially in a high-spin and high-g projectile launch environment.

  14. Rotation of the swing plane of Foucault's pendulum and Thomas spin precession: two sides of one coin

    International Nuclear Information System (INIS)

    Krivoruchenko, Mikhail I

    2009-01-01

    Using elementary geometric tools, we apply essentially the same methods to derive expressions for the rotation angle of the swing plane of Foucault's pendulum and the rotation angle of the spin of a relativistic particle moving in a circular orbit (the Thomas precession effect). (methodological notes)

  15. Rotation of the swing plane of Foucault's pendulum and Thomas spin precession: two sides of one coin

    Energy Technology Data Exchange (ETDEWEB)

    Krivoruchenko, Mikhail I [Alikhanov Institute for Theoretical and Experimental Physics, Russian Federation State Scientific Center, Moscow (Russian Federation)

    2009-08-31

    Using elementary geometric tools, we apply essentially the same methods to derive expressions for the rotation angle of the swing plane of Foucault's pendulum and the rotation angle of the spin of a relativistic particle moving in a circular orbit (the Thomas precession effect). (methodological notes)

  16. Spin Transport Measurements in Hydrogenated Graphene Devices

    Science.gov (United States)

    Koon, Gavin; Balakrishnan, Jayakumar; Oezyilmaz, Barbaros

    2013-03-01

    Graphene with all its extraordinary properties still fall short when it comes to manipulation of electron spins. Chemically modified Graphene has been explored by many to further enhance Graphene properties, tailoring it to suit desired application purposes. Here we study the effects of hydrogenation rate on graphene spin transport, spin relaxation time and length in this defected system. These findings are important for future theoretical and experimental studies on other adatoms modified Graphene.

  17. Spin diffusion in bulk GaN measured with MnAs spin injector

    KAUST Repository

    Jahangir, Shafat

    2012-07-16

    Spin injection and precession in bulk wurtzite n-GaN with different doping densities are demonstrated with a ferromagnetic MnAs contact using the three-terminal Hanle measurement technique. Theoretical analysis using minimum fitting parameters indicates that the spin accumulation is primarily in the n-GaN channel rather than at the ferromagnet (FM)/semiconductor (SC) interface states. Spin relaxation in GaN is interpreted in terms of the D’yakonov-Perel mechanism, yielding a maximum spin lifetime of 44 ps and a spin diffusion length of 175 nm at room temperature. Our results indicate that epitaxial ferromagnetic MnAs is a suitable high-temperature spin injector for GaN.

  18. ROTATING STARS AND THE FORMATION OF BIPOLAR PLANETARY NEBULAE. II. TIDAL SPIN-UP

    Energy Technology Data Exchange (ETDEWEB)

    García-Segura, G. [Instituto de Astronomía, Universidad Nacional Autónoma de Mexico, Km. 103 Carr. Tijuana-Ensenada, 22860, Ensenada, B. C. (Mexico); Villaver, E. [Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Manchado, A. [Instituto de Astrofísica de Canarias, Via Láctea s/n, E-38200 La Laguna, Tenerife (Spain); Langer, N. [Argelander-Institut für Astronomie, Universität Bonn, D-53121 Bonn (Germany); Yoon, S.-C., E-mail: ggs@astrosen.unam.mx [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 (Korea, Republic of)

    2016-06-01

    We present new binary stellar evolution models that include the effects of tidal forces, rotation, and magnetic torques with the goal of testing planetary nebulae (PNs) shaping via binary interaction. We explore whether tidal interaction with a companion can spin-up the asymptotic giant brach (AGB) envelope. To do so, we have selected binary systems with main-sequence masses of 2.5 M {sub ⊙} and 0.8 M {sub ⊙} and evolve them allowing initial separations of 5, 6, 7, and 8 au. The binary stellar evolution models have been computed all the way to the PNs formation phase or until Roche lobe overflow (RLOF) is reached, whatever happens first. We show that with initial separations of 7 and 8 au, the binary avoids entering into RLOF, and the AGB star reaches moderate rotational velocities at the surface (∼3.5 and ∼2 km s{sup −1}, respectively) during the inter-pulse phases, but after the thermal pulses it drops to a final rotational velocity of only ∼0.03 km s{sup −1}. For the closest binary separations explored, 5 and 6 au, the AGB star reaches rotational velocities of ∼6 and ∼4 km s{sup −1}, respectively, when the RLOF is initiated. We conclude that the detached binary models that avoid entering the RLOF phase during the AGB will not shape bipolar PNs, since the acquired angular momentum is lost via the wind during the last two thermal pulses. This study rules out tidal spin-up in non-contact binaries as a sufficient condition to form bipolar PNs.

  19. MUSIC for Faraday rotation measure synthesis

    Science.gov (United States)

    Andrecut, M.

    2013-03-01

    Faraday rotation measure (RM) synthesis requires the recovery of the Faraday dispersion function (FDF) from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we propose a novel deconvolution method based on an extension of the MUltiple SIgnal Classification (MUSIC) algorithm. The complexity and speed of the method is determined by the eigen-decomposition of the covariance matrix of the observed polarizations. We show numerically that for high to moderate signal-to-noise ratio (S/N) cases the RM-MUSIC method is able to recover the Faraday depth values of closely spaced pairs of thin RM components, even in situations where the peak response of the FDF is outside of the RM range between the two input RM components. This result is particularly important because the standard deconvolution approach based on RM-CLEAN fails systematically in such situations, due to its greedy mechanism used to extract the RM components. For low S/N situations, both the RM-MUSIC and RM-CLEAN methods provide similar results.

  20. Decoding the subjective rotation direction of the spinning dancer from fMRI data

    Science.gov (United States)

    Song, SuTao; Liu, Yang; Zhang, JiaCai

    2015-03-01

    A challenging goal in neuroscience is to decode the mental states from brain activity. Recently, researchers have successfully deciphered the objective and static visual stimuli (such as orientation of stripes and category of objects) from brain activity recorded by functional magnetic resonance imaging (fMRI) technology. However, few studies focused on the decoding of the rotation direction perception of the actual three-dimensional world with two-dimensional representations. In this study, the brain activities when subjects viewed the animation of the spinning dancer in the front were recorded using fMRI, and subjects reported the viewing-from-bottom motion direction (clockwise or counterclockwise) by press different buttons. One multivariate pattern analysis method, support vector machine was trained to predict the rotation direction. The 5-fold cross-validation result showed that the subjective rotation direction reported by the subjects can be predicted from fMRI with a possibility above the chance level, which imply that fMRI activity of the brain contains detailed rotation direction information that can reliably predict the subjective perception.

  1. Atmospheric thermal tides and planetary spin. I. The complex interplay between stratification and rotation

    Science.gov (United States)

    Auclair-Desrotour, P.; Mathis, S.; Laskar, J.

    2018-02-01

    Context. Thermal atmospheric tides can torque telluric planets away from spin-orbit synchronous rotation, as observed in the case of Venus. They thus participate in determining the possible climates and general circulations of the atmospheres of these planets. Aims: The thermal tidal torque exerted on an atmosphere depends on its internal structure and rotation and on the tidal frequency. Particularly, it strongly varies with the convective stability of the entropy stratification. This dependence has to be characterized to constrain and predict the rotational properties of observed telluric exoplanets. Moreover, it is necessary to validate the approximations used in global modelings such as the traditional approximation, which is used to obtain separable solutions for tidal waves. Methods: We wrote the equations governing the dynamics of thermal tides in a local vertically stratified section of a rotating planetary atmosphere by taking into account the effects of the complete Coriolis acceleration on tidal waves. This allowed us to analytically derive the tidal torque and the tidally dissipated energy, which we used to discuss the possible regimes of tidal dissipation and to examine the key role played by stratification. Results: In agreement with early studies, we find that the frequency dependence of the thermal atmospheric tidal torque in the vicinity of synchronization can be approximated by a Maxwell model. This behavior corresponds to weakly stably stratified or convective fluid layers, as observed previously. A strong stable stratification allows gravity waves to propagate, and makes the tidal torque negligible. The transition is continuous between these two regimes. The traditional approximation appears to be valid in thin atmospheres and in regimes where the rotation frequency is dominated by the forcing or the buoyancy frequencies. Conclusions: Depending on the stability of their atmospheres with respect to convection, observed exoplanets can be tidally

  2. Rotational stability of femoral osteosynthesis in femoral fractures - navigated measurements.

    Science.gov (United States)

    Citak, Mustafa; Kendoff, Daniel; Gardner, Michael J; Oszwald, Markus; O'Loughlin, Padhraig F; Olivier, Lucien C; Krettek, Christian; Hüfner, Tobias; Citak, Musa

    2009-01-01

    Rotational malalignment after intramedullary nailing of femoral fractures is common, and symptoms occur when malrotation reaches 15 degrees . Intraoperative measurement of rotation remains difficult, and multiple techniques have been described to address this. Regardless of the method used, rotational toggling may occur between the interlocking screws and the screw holes. We hypothesized that a clinically significant amount of rotation may occur with standard statically locked intramedullary nails. Mid-shaft diaphyseal fractures were created in 24 cadaveric femurs. Specimens were divided into 4 groups, and were stabilized with a statically locked intramedullary nail, a dynamically locked intramedullary nail, a compression plate, and a locking plate. Six additional femurs were kept intact as a control group. Specimens were mounted in a custom holding jig, which stabilized the constructs proximally and allowed free rotation distally. A computer navigation system was applied, and the femoral anteversion was measured. 4 N-m of internal and external torque was applied, and the change in version was measured. The statically locked nails rotated 14.2 degrees , and the dynamically locked group rotated 15.7 degrees . Both intramedullary nail groups showed significantly greater rotation than the plated groups. The compression plate specimens rotated 6.5 degrees on average, and the locked plate group rotated 3.8 degrees . Intramedullary femoral nailing with static or dynamic interlocking allows 15 degrees of rotation of the femur around the nail under physiologic load. This may exacerbate intraoperative errors in determining and setting rotation. Angular stable plates or nails may minimize this problem.

  3. Non-contact measurement of rotation angle with solo camera

    Science.gov (United States)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  4. Measurement of the Spin of the Omega- Hyperon at Babar

    International Nuclear Information System (INIS)

    Aubert, B.

    2006-01-01

    A measurement of the spin of the (Omega) - hyperon produced through the exclusive process Ξ c 0 → (Omega) - K + is presented using a total integrated luminosity of 116 fb -1 recorded with the BABAR detector at the e + e - asymmetric-energy B-Factory at SLAC. Under the assumption that the Ξ c 0 has spin 1/2, the angular distribution of the Λ from (Omega) - → ΛK - decay is inconsistent with all half-integer (Omega) - spin values other than 3/2. Lower statistics data for the process (Omega) c 0 → (Omega) - π + from a 230 fb -1 sample are also found to be consistent with (Omega) - spin 3/2. If the Ξ c 0 spin were 3/2, an (Omega) - spin of 5/2 cannot be excluded

  5. Measuring spin of black holes in the universe

    Indian Academy of Sciences (India)

    Table of contents. Measuring spin of black holes in the universe · What is black hole? Accretion Disk and Jet · What is black hole's spin? Accretion Disk · Black Hole's Potential · Light Curves: Photon Count Rate Vs Time · Quasi-Periodic Oscillation · Slide 9 · Model · Slide 11 · Slide 12 · Slide 13 · Summary.

  6. Competition/coexistence of magnetism and superconductivity in iron pnictides probed by muon spin rotation

    International Nuclear Information System (INIS)

    Takeshita, Soshi; Kadono, Ryosuke

    2009-01-01

    The presence of macroscopic phase separation into superconducting and magnetic phases in LaFeAsO 1-x F x and CaFe 1-x Co x AsF is demonstrated by muon spin rotation (μSR) measurement across their phase boundaries (x=0.06 for LaFeAsO 1-x F x and x=0.075-0.15 for CaFe 1-x Co x AsF). In LaFeAsO 0.94 F 0.06 , both magnetism and superconductivity develop simultaneously below a common critical temperature, T m ≅T c ≅18 K, where the magnetism is characterized by strong randomness. A similar, but more distinct segregation of these two phases is observed in CaFe 1-x Co x AsF, where the magnetic phase retains T m close to that of the parent compound (T c m ≅80-120 K) and the superconducting volume fraction is mostly proportional to the Co content x. The close relationship between magnetism and superconductivity is discussed based on these experimental observations. Concerning the superconducting phase, an assessment is made on the anisotropy of the order parameter in the superconducting state of LaFeAsO 1-x F x , CaFe 1-x Co x AsF and Ba 1-x K x Fe 2 As 2 (x=0.4) based on the temperature dependence of superfluid density [n s (T)] measured by μSR. The gap parameter, 2Δ/k B T c , determined from n s (T) exhibits a tendency that values in the hole-doped pnictides (Ba 1-x K x Fe 2 As 2 ) are much greater than those in electron-doped ones (LaFeAsO 1-x F x and CaFe 1-x Co x AsF), suggesting a difference in the coupling to bosons mediating the Cooper pairs between relevant d electron bands.

  7. Searching for Excess Rotation Measures in Galaxy Clusters with the ...

    Indian Academy of Sciences (India)

    Abstract. We present a statistical analysis of the rotation measure (RM) catalogue from the NVSS in search for a statistical excess of rotation measure through Abell clusters. After excluding the data known to be affected by the large-scale magnetic field of the Galaxy (b ≤ |30|), we consider RMs as a function of normalized ...

  8. Rotation Measure Distribution in Compact Steep-steep Spectrum ...

    African Journals Online (AJOL)

    We have used radio polarization data at different frequencies to obtain the rotation measure, RM, the source rest frame rotation measure, RM(1+z)2 and the spectral index, α in a sample of Compact Steepspectrum Sources (CSSs). The CSS quasar sub-sample has RM(1+z)2 median values of ~-15.01 and 14.13 for the jet ...

  9. Recent Progress on the Description of Relativistic Spin: Vector Model of Spinning Particle and Rotating Body with Gravimagnetic Moment in General Relativity

    Directory of Open Access Journals (Sweden)

    Alexei A. Deriglazov

    2017-01-01

    Full Text Available We review the recent results on development of vector models of spin and apply them to study the influence of spin-field interaction on the trajectory and precession of a spinning particle in external gravitational and electromagnetic fields. The formalism is developed starting from the Lagrangian variational problem, which implies both equations of motion and constraints which should be presented in a model of spinning particle. We present a detailed analysis of the resulting theory and show that it has reasonable properties on both classical and quantum level. We describe a number of applications and show how the vector model clarifies some issues presented in theoretical description of a relativistic spin: (A one-particle relativistic quantum mechanics with positive energies and its relation with the Dirac equation and with relativistic Zitterbewegung; (B spin-induced noncommutativity and the problem of covariant formalism; (C three-dimensional acceleration consistent with coordinate-independence of the speed of light in general relativity and rainbow geometry seen by spinning particle; (D paradoxical behavior of the Mathisson-Papapetrou-Tulczyjew-Dixon equations of a rotating body in ultrarelativistic limit, and equations with improved behavior.

  10. Measurement of plasma conductivity using faraday rotation of submillimeter waves

    International Nuclear Information System (INIS)

    Kuzmenko, P.J.; Self, S.A.

    1983-01-01

    This paper examines the application of Faraday rotation to the measurement of electron combustion MHD plasmas. Details on the design of a working system are given, including the selection of operating wavelength. A theoretical comparison between the Faraday rotation technique and two-path interferometry shows Faraday rotation in its simplest form to be somewhat less sensitive to changes in electron concentration. This deficit can be balanced against greater immunity to vibration and thermal drift. Improved techniques of measuring the rotation angle promise greater sensitivity. A preliminary experiment has verified the technique

  11. Rotational Laser Cooling of MgH+ Ions and Rotational Rate Measurements

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Staanum, Peter; Højbjerre, Klaus

    A method of laser cooling vibrationally and translationally cold trapped MgH+ ions to the rotational ground state using optical pumping was recently demonstrated in our group [1]. This method relies on the 293 K blackbody radiation to redistribute population among the rotational states, while...... exciting a single rovibrational transition within the X1Σ+ electronic ground state for optical pumping into the rovibrational ground state. To model the expected rotational state distributions after the application of the laser beam, one has to know the various rotational transitions rates in the present...... blackbody radiation field. To undertake such modelling, we will carry out measurements of a series of transition rates between rotational states in the vibronic ground state at room temperature. The measurements will be performed by the same Resonance Enhanced Multi-Photon Dissociation (REMPD) process used...

  12. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    Science.gov (United States)

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

    2015-10-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  13. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    Directory of Open Access Journals (Sweden)

    Luo Jun

    2015-10-01

    Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  14. Dynamic measurement of axial vertebral rotation and rotational flexibility in scoliosis by flouroscopic method.

    Science.gov (United States)

    Lim, H H; Ong, C H

    2001-06-01

    The Pedriolle torsion meter is an established method of vertebral rotation assessment in scoliosis. However, the assessment of scoliosis by this method is static and indirect. The objective of this study is to compare the accuracy of a direct method of assessing scoliosis rotation by fluoroscopy compared to the Pedriolle torsion meter. Secondly, to determine that vertebral body rotation changes with supine posture compared to erect position. Eight volunteers with idiopathic scoliosis were assessed for the apical vertebral rotation with this method and the Pedriolle torsion meter. These patients were also assessed in the supine and erect position with the fluoroscopic method to determine if the apical vertebral rotation would change with posture. The mean Cobb angle of the curves was 62.8 degrees (range 45 degrees to 86 degrees). The mean apical vertebral rotation in a standing position was assessed to be 21.5 degrees by Pedriolle torsion meter and 29 degrees by the fluoroscopic method. This difference was not statistically significant by the student t-test. In most patient, the rotation of vertebrae improved by a varying degree ranging from none to 24 degrees in the supine position. In conclusion, the fluoroscopic method is an alternate mean of measuring vertebrae rotation in idiopathic scoliosis, with comparable accuracy to the Pedriolle torsion meter method. The amount of vertebral rotation changes with posture of the patient.

  15. Muon spin rotation studies involving muonium at high pH

    International Nuclear Information System (INIS)

    Ng, B.W.; Stadlbauer, J.M.; Walker, D.C.

    1983-06-01

    The muon spin rotation method was used to determine the muon yields in concentrated KOH solutions and to evaluate Arrhenius parameters for the reaction of muonium with hydroxyl ions in dilute aqueous solutions. This latter reaction is relatively slow due to a substantial activation energy, yet there is no kinetic isotope effect at room temperature. The kinetics are well represented by the relationship log ksub(M) = 14.38 - 2100(+-260)/T. The observed enhancement of the diamagentic muon yield (Psub(D)) from 0.62 to 0.79 as the (KOH) was increased from 0 to 20 M can be accounted for in terms of a 'hot-model' mechanism, by allowing Ksub(M) (or the hot fraction) to vary somewhat. The failure of Psub(D) to reach 1.0 in such concentrated OH - solutions shows that the muons do not all emerge from the epithermal processes of the track as free μ + ions

  16. Measuring spin of black holes in the universe

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Measuring spin of black holes in the universe. Department of Physics Indian Institute of Science Bangalore. Notes: 74th Annual Meeting of Indian Academy of Science.

  17. Effect of nuclear spin on chemical reactions and internal molecular rotation

    International Nuclear Information System (INIS)

    Sterna, L.L.

    1980-12-01

    Part I of this dissertation is a study of the magnetic isotope effect, and results are presented for the separation of 13 C and 12 C isotopes. Two models are included in the theoretical treatment of the effect. In the first model the spin states evolve quantum mechanically, and geminate recombination is calculated by numerically integrating the collision probability times the probability the radical pair is in a singlet state. In the second model the intersystem crossing is treated via first-order rate constants which are average values of the hyperfine couplings. Using these rate constants and hydrodynamic diffusion equations, an analytical solution, which accounts for all collisions, is obtained for the geminate recombination. The two reactions studied are photolysis of benzophenone and toluene and the photolytic decomposition of dibenzylketone (1,3-diphenyl-2-propanone). No magnetic isotope effect was observed in the benzophenone reaction. 13 C enrichment was observed for the dibenzylketone reaction, and this enrichment was substantially enhanced at intermediate viscosities and low temperatures. Part II of this dissertation is a presentation of theory and results for the use of Zeeman spin-lattice relaxation as a probe of methyl group rotation in the solid state. Experimental results are presented for the time and angular dependences of rotational polarization, the methyl group magnetic moment, and methyl-methyl steric interactions. The compounds studied are 2,6-dimethylphenol, methyl iodide, 1,4,5,8-tetramethylanthracene, 1,4,5,8-tetramethylnaphthalene, 1,2,4,5-tetramethylbenzene, and 2,3-dimethylmaleicanhydride

  18. Spin correlation tensor for measurement of quantum entanglement in electron-electron scattering

    Science.gov (United States)

    Tsurikov, D. E.; Samarin, S. N.; Williams, J. F.; Artamonov, O. M.

    2017-04-01

    We consider the problem of correct measurement of a quantum entanglement in the two-body electron-electron scattering. An expression is derived for a spin correlation tensor of a pure two-electron state. A geometric measure of a quantum entanglement as the distance between two forms of this tensor in entangled and separable cases is presented. Due to such definition, one does not need to look for the closest separable state to the analyzed state. We prove that introduced measure satisfies properties of a valid entanglement measure: nonnegativity, discriminance, normalization, non-growth under local operations and classical communication. This measure is calculated for a problem of electron-electron scattering. We prove that it does not depend on the azimuthal rotation angle of the second electron spin relative to the first electron spin before scattering. We specify how to find a spin correlation tensor and the related measure of a quantum entanglement in an experiment with electron-electron scattering. Finally, the introduced measure is extended to the mixed states.

  19. Anisotropic Rotational Diffusion Studied by Nuclear Spin Relaxation and Molecular Dynamics Simulation: An Undergraduate Physical Chemistry Laboratory

    Science.gov (United States)

    Fuson, Michael M.

    2017-01-01

    Laboratories studying the anisotropic rotational diffusion of bromobenzene using nuclear spin relaxation and molecular dynamics simulations are described. For many undergraduates, visualizing molecular motion is challenging. Undergraduates rarely encounter laboratories that directly assess molecular motion, and so the concept remains an…

  20. Magnetic states of MnP: muon-spin rotation studies.

    Science.gov (United States)

    Khasanov, R; Amato, A; Bonfà, P; Guguchia, Z; Luetkens, H; Morenzoni, E; De Renzi, R; Zhigadlo, N D

    2017-04-26

    Muon-spin rotation data collected at ambient pressure (p) and at p  =  2.42 GPa in MnP were analyzed to check their consistency with various low- and high-pressure magnetic structures reported in the literature. Our analysis confirms that in MnP the low-temperature and low-pressure helimagnetic phase is characterised by an increased value of the average magnetic moment compared to the high-temperature ferromagnetic phase. An elliptical double-helical structure with a propagation vector [Formula: see text], an a-axis moment elongated by approximately 18% and an additional tilt of the rotation plane towards c-direction by [Formula: see text]-8° leads to a good agreement between the theory and the experiment. The analysis of the high-pressure μSR data reveals that the new magnetic order appearing for pressures exceeding 1.5 GPa can not be described by keeping the propagation vector [Formula: see text]. Even the extreme case-decoupling the double-helical structure into four individual helices-remains inconsistent with the experiment. It is shown that the high-pressure magnetic phase which is a precursor of superconductivity is an incommensurate helical state with [Formula: see text].

  1. Radiographic femoral varus measurement is affected unpredictably by femoral rotation

    DEFF Research Database (Denmark)

    Miles, James Edward

    and externally by 5° and 10° using plastic wedges. Accuracy of rotation was within +1°. Digital radiographs were obtained at each position. Varus angles were measured using ImageJ, employing two definitions of PFLA. Mean varus angles increased with 10° of either internal or external rotation with both PFLA...... rotation angles. The effect of rotation on varus angle measurements in these femoral specimens contradicts a previous report using CT. The most probable explanation is the difference in femoral positioning: the CT study used a slightly elevated position compared to that in this study, resulting in better...... visualisation of the condylar articular surfaces. Zero elevation frequently results in the articular surfaces being obscured by the trochlear ridges, even when positioned perfectly. Varus measurements vary unpredictably as a result of femoral rotation and this effect is likely further influenced by femoral...

  2. Measurement of Projectile Rate of Spin

    Science.gov (United States)

    1976-02-12

    an~d Idendtir by block nsmbor) Projectile *Yaw Cards *SabotN rSpin *New 1%A@SrACT (Clod~aw - a’u M abe oft% p N mfseFsid tim flr 6r. black n~mbw) 1...a distance that permits about five revolutions of behe projectile between It and the first camera. Additional cameras may beused to increase the...or in "dark boxes ." Microflash techniques may be used to obtain adequate lighting tinder these conditions. The projectile is momentarily illuminated

  3. Cloning and joint measurements of incompatible components of spin

    International Nuclear Information System (INIS)

    Brougham, Thomas; Andersson, Erika; Barnett, Stephen M.

    2006-01-01

    A joint measurement of two observables is a simultaneous measurement of both quantities upon the same quantum system. When two quantum-mechanical observables do not commute, then a joint measurement of these observables cannot be accomplished directly by projective measurements alone. In this paper we shall discuss the use of quantum cloning to perform a joint measurement of two components of spin associated with a qubit system. We introduce cloning schemes which are optimal with respect to this task. The cloning schemes may be thought to work by cloning two components of spin onto their outputs. We compare the proposed cloning machines to existing cloners

  4. On Physical Interpretation of the In-Site Measurement of Earth Rotation by Ring Laser Gyrometers

    Science.gov (United States)

    Chao, B. F.

    2004-01-01

    Large ring laser gyrometers under development have demonstrated the capability of detecting minute ground motions and deformations on a wide range of timescales. The next challenge and goal is to measure the Earth's rotation variations to a precision that rivals that of the present space-geodesy techniques, thus providing an in-situ (and cost effective alternatives of Earth rotation measurement for geophysical research and geodetic applications. Aside from thermal and mechanical instabilities, "undesirable" ground motion and tilt that appear in the signal will need to be removed before any variation in Earth rotation can be detected. Removal of these signals, some of them are larger than the sought rotation signals, has been a typical procedure in many precise geophysical instruments, such as gravimeters, seismometers, and tiltmeters. The remaining Earth rotation signal resides in both the spin around the axis and in the orientation of the axis. In the case of the latter, the in-situ measurement is complementary to the space-geodetic observables in terms of polar motion and nutation, a fact to be exploited.

  5. Spin-Mechatronics

    Science.gov (United States)

    Matsuo, Mamoru; Saitoh, Eiji; Maekawa, Sadamichi

    2017-01-01

    We investigate the interconversion phenomena between spin and mechanical angular momentum in moving objects. In particular, the recent results on spin manipulation and spin-current generation by mechanical motion are examined. In accelerating systems, spin-dependent gauge fields emerge, which enable the conversion from mechanical angular momentum into spins. Such a spin-mechanical effect is predicted by quantum theory in a non-inertial frame. Experiments which confirm the effect, i.e., the resonance frequency shift in nuclear magnetic resonance, the stray field measurement of rotating metals, and electric voltage generation in liquid metals, are discussed.

  6. Glenohumeral internal rotation measurements differ depending on stabilization techniques.

    Science.gov (United States)

    Wilk, Kevin E; Reinold, Michael M; Macrina, Leonard C; Porterfield, Ron; Devine, Kathleen M; Suarez, Kim; Andrews, James R

    2009-03-01

    The loss of glenohumeral internal rotation range of motion in overhead athletes has been well documented in the literature. Several different methods of assessing this measurement have been described, making comparison between the results of studies difficult. Significant differences in the amount of internal rotation range of motion exist when using different methods of stabilization. Descriptive laboratory study. THREE TECHNIQUES WERE USED BILATERALLY IN RANDOM FASHION TO MEASURE GLENOHUMERAL INTERNAL ROTATION RANGE OF MOTION: stabilization of the humeral head, stabilization of the scapula, and visual inspection without stabilization. An initial study on 20 asymptomatic participants was performed to determine the intrarater and interrater reliability for each measurement technique. Once complete, measurements were performed on 39 asymptomatic professional baseball players to determine if a difference existed in measurement techniques and if there was a significant side-to-side difference. A 2-way repeated-measures analysis of variance was used. While interrater reliability was fair between all 3 methods, scapular stabilization provided the best intrarater reliability. A statistically significant difference was observed between all 3 methods (P < .001). Internal rotation was significantly less in the dominant shoulder than in the nondominant shoulder (P < .001). Differences in internal rotation range of motion measurements exist when using different methods. The scapula stabilization method displayed the highest intrarater reproducibility and should be considered when evaluating internal rotation passive range of motion of the glenohumeral joint. A standardized method of measuring internal rotation range of motion is required to accurately compare physical examinations of patients. The authors recommend the use of the scapula stabilization method to assess internal rotation range of motion by allowing normal glenohumeral arthrokinematics while stabilizing the

  7. Spin motion determination of the Envisat satellite through laser ranging measurements from a single pass measured by a single station

    Science.gov (United States)

    Pittet, Jean-Noël; Šilha, Jiří; Schildknecht, Thomas

    2018-02-01

    The Satellite Laser Ranging (SLR) technology is used to accurately determine the position of space objects equipped with so-called retro-reflectors or retro-reflector arrays (RRA). This type of measurement allows to measure the range to the spacecraft with high precision, which leads to determination of very accurate orbits for these targets. Non-active spacecraft, which are not attitude controlled any longer, tend to start to spin or tumble under influence of the external and internal torques and forces. If the return signal is measured for a non-spherical non-active rotating object, the signal in the range residuals with respect to the reference orbit is more complex. For rotating objects the return signal shows an oscillating pattern or patterns caused by the RRA moving around the satellite's centre of mass. This behaviour is projected onto the radial component measured by the SLR. In our work, we demonstrate how the SLR ranging technique from one sensor to a satellite equipped with a RRA can be used to precisely determine its spin motion during one passage. Multiple SLR measurements of one target over time allow to accurately monitor spin motion changes which can be further used for attitude predictions. We show our solutions of the spin motion determined for the non-active ESA satellite Envisat obtained from measurements acquired during years 2013-2015 by the Zimmerwald SLR station, Switzerland. All the necessary parameters are defined for our own so-called point-like model which describes the motion of a point in space around the satellite centre of mass.

  8. Dynamic viscoelasticity measurement under alternative torque using electromagnetically spinning method with quadruple electromagnets.

    Science.gov (United States)

    Matsuura, Yusuke; Hirano, Taichi; Sakai, Keiji

    2017-07-01

    In this study, we developed a novel type of rheological measurement system. Here, a spherical probe is driven to rotate periodically by applying torques using quadruple electromagnets in a noncontact manner. Moreover, this system is an enhancement of our electromagnetically spinning (EMS) viscometer, which is widely used for measuring rheological flow curves in various industrial fields. The quadruple EMS method provides the frequency spectrum of viscoelasticity, in addition to shear viscosity, in a steady flow by switching the operation modes of the driving torque. We show the results obtained for Newtonian fluids and viscoelastic materials and demonstrate the validity of the system.

  9. Measurements of $t\\overline{t}$ Spin Correlations in CMS

    CERN Document Server

    Beernaert, Kelly Simone

    2014-01-01

    We present an overview of the measurements of $t\\bar{t}$ spin correlations in the CMS Collaboration. We present two analyses both in the dilepton channel using proton-proton collisions at $\\sqrt{s}\\, =\\, 7$ TeV based on an integrated luminosity of 5.0 fb$^{-1}$. The spin correlations and polarization are measured using angular asymmetries. The results are consistent with unpolarized top quarks and Standard Model spin correlation. The second analysis sets a limit on the real part of the top-quark chromo-magnetic dipole moment of $-0.043\\, <\\, Re({\\hat{\\mu}}_{t})\\, <\\, 0.117$ at $95\\,%$ confidence level through the measured azimuthal angle difference between the two charged leptons from $t\\bar{t}$ production.

  10. The Ceres gravity field, spin pole, rotation period and orbit from the Dawn radiometric tracking and optical data

    Science.gov (United States)

    Konopliv, A. S.; Park, R. S.; Vaughan, A. T.; Bills, B. G.; Asmar, S. W.; Ermakov, A. I.; Rambaux, N.; Raymond, C. A.; Castillo-Rogez, J. C.; Russell, C. T.; Smith, D. E.; Zuber, M. T.

    2018-01-01

    Ceres' gravity field and rotational parameters have been precisely measured using 1.5 years of radiometric Doppler and range data and optical landmark tracking from the Dawn spacecraft in orbit about the dwarf planet. As was the case with Dawn at Vesta, the gravity field, orientation parameters, landmark locations, and Ceres' orbit are jointly estimated in a global solution. Even though Dawn's radio science investigation at Ceres was complicated by additional thrusting for attitude control, the resulting spherical harmonic gravity field has a half-wavelength resolution of up to 82 km (degree 18) near the equator, which is similar harmonic resolution to that of Vesta. The gravity field is consistent with Airy isostatic compensation, and this model assumption limits Ceres' crustal density to be between 1200 and 1600 kg/m3 for two-layer and three-layer models with mean crustal thickness between 27 and 43 km. The compensation depth is determined using admittance between gravity and gravity from topography and is superior to admittance between gravity and topography. The gravitational mass of Ceres is determined to better than 0.002% (GMCeres = 62.62736 ± 0.00040 km3/s2), the spin pole location is improved by 10× over previous results with right ascension (α = 291.427°) and declination (δ = 66.760°) uncertainty less than 0.001°, and the rotation rate is improved by ∼100× over previous determinations from Hubble Space Telescope (HST) images. Ceres' heliocentric orbit has also been improved, with about 17 months of precision range measurements reducing ephemeris uncertainties to about 10 m during the Dawn timeframe.

  11. Further Development of Rotating Rake Mode Measurement Data Analysis

    Science.gov (United States)

    Dahl, Milo D.; Hixon, Ray; Sutliff, Daniel L.

    2013-01-01

    The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. After analysis of the measured data, the mode amplitudes and phases were quantified. For low-speed fans within axisymmetric ducts, mode power levels computed from rotating rake measured data would agree with the far-field power levels on a tone by tone basis. However, this agreement required that the sound from the noise sources within the duct propagated outward from the duct exit without reflection at the exit and previous studies suggested conditions could exist where significant reflections could occur. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. The fit equations were also modified to allow evanescent mode amplitudes to be computed. This extension of the rotating rake data analysis technique was tested using simulated data, numerical code produced data, and preliminary in-duct measured data.

  12. Deflection Shape Reconstructions of a Rotating Five-blade Helicopter Rotor from TLDV Measurements

    International Nuclear Information System (INIS)

    Fioretti, A.; Castellini, P.; Tomasini, E. P.; Di Maio, D.; Ewins, D. J.

    2010-01-01

    Helicopters are aircraft machines which are subjected to high level of vibrations, mainly due to spinning rotors. These are made of two or more blades attached by hinges to a central hub, which can make the dynamic behaviour difficult to study. However, they share some common dynamic properties with the ones expected in bladed discs, thereby the analytical modelling of rotors can be performed using some assumptions as the ones adopted for the bladed discs. This paper presents results of a vibrations study performed on a scaled helicopter rotor model which was rotating at a fix rotational speed and excited by an air jet. A simplified analytical model of that rotor was also produced to help the identifications of the vibration patterns measured using a single point tracking-SLDV measurement method.

  13. PREFACE: 13th International Conference on Muon Spin Rotation, Relaxation and Resonance

    Science.gov (United States)

    2014-12-01

    The 13th International Conference on Muon Spin Rotation, Relaxation and Resonance (μSR2014) organized by the Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute in collaboration with the University of Zurich and the University of Fribourg, was held in Grindelwald, Switzerland from 1st to 6th June 2014. The conference provided a forum for researchers from around the world with interests in the applications of μSR to study a wide range of topics including condensed matter physics, materials and molecular sciences, chemistry and biology. Polarized muons provide a unique and versatile probe of matter, enabling studies at the atomic level of electronic structure and dynamics in a wide range of systems. The conference was the thirteenth in a series, which began in Rorschach in 1978 and it took place for the third time in Switzerland. The previous conferences were held in Cancun, Mexico (2011), Tsukuba, Japan (2008), Oxford, UK (2005), Williamsburg, USA (2002), Les Diablerets, Switzerland (1999), Nikko, Japan (1996), Maui, USA (1993), Oxford, UK (1990), Uppsala, Sweden (1986), Shimoda, Japan (1983), Vancouver, Canada (1980), and Rorschach, Switzerland (1978). These conference proceedings contain 67 refereed publications from presentations covering magnetism, superconductivity, chemistry, semiconductors, biophysics and techniques. The conference logo, displayed in the front pages of these proceedings, represents both the location of μSR2014 in the Alps and the muon-spin rotation technique. The silhouette represents the famous local mountains Eiger, Mönch and Jungfrau as drawn by the Swiss painter Ferdinand Hodler and the apple with arrow is at the same time a citation of the Wilhelm Tell legend and a remembrance of the key role played by the muon spin and the asymmetric muon decay (which for the highest positron energy has an apple like shape). More than 160 participants (including 32 registered as students and 13 as accompanying persons) from 19 countries

  14. The one-parameter subgroup of rotations generated by spin transformations in three-dimensional real space

    International Nuclear Information System (INIS)

    Gazoya, E.D.K.; Prempeh, E.; Banini, G.K.

    2015-01-01

    The relationship between the spin transformations of the special linear group of order 2, SL (2, C) and the aggregate SO(3) of the three-dimensional pure rotations when considered as a group in itself (and not as a subgroup of the Lorentz group), is investigated. It is shown, by the spinor map X - → AXA ct which is all action of SL(2. C) on the space of Hermitian matrices, that the one- parameter subgroup of rotations generated are precisely those of angles which are multiples 2π. (au)

  15. Instabilities and spin-up behaviour of a rotating magnetic field driven flow in a rectangular cavity

    Science.gov (United States)

    Galindo, V.; Nauber, R.; Räbiger, D.; Franke, S.; Beyer, H.; Büttner, L.; Czarske, J.; Eckert, S.

    2017-11-01

    This study presents numerical simulations and experiments considering the flow of an electrically conducting fluid inside a cube driven by a rotating magnetic field (RMF). The investigations are focused on the spin-up, where a liquid metal (GaInSn) is suddenly exposed to an azimuthal body force generated by the RMF and the subsequent flow development. The numerical simulations rely on a semi-analytical expression for the induced electromagnetic force density in an electrically conducting medium inside a cuboid container with insulating walls. Velocity distributions in two perpendicular planes are measured using a novel dual-plane, two-component ultrasound array Doppler velocimeter with continuous data streaming, enabling long term measurements for investigating transient flows. This approach allows identifying the main emerging flow modes during the transition from stable to unstable flow regimes with exponentially growing velocity oscillations using the Proper Orthogonal Decomposition method. Characteristic frequencies in the oscillating flow regimes are determined in the super critical range above the critical magnetic Taylor number T ac≈1.26 ×1 05, where the transition from the steady double vortex structure of the secondary flow to an unstable regime with exponentially growing oscillations is detected. The mean flow structures and the temporal evolution of the flow predicted by the numerical simulations and observed in experiments are in very good agreement.

  16. Negative oxygen isotope effect on the static spin stripe order in superconducting La(2-x)Ba(x)CuO(4) (x=1/8) observed by muon-spin rotation.

    Science.gov (United States)

    Guguchia, Z; Khasanov, R; Bendele, M; Pomjakushina, E; Conder, K; Shengelaya, A; Keller, H

    2014-08-01

    Large negative oxygen-isotope (^{16}O and ^{18}O) effects (OIEs) on the static spin-stripe-ordering temperature T_{so} and the magnetic volume fraction V_{m} were observed in La_{2-x}Ba_{x}CuO_{4}(x=1/8) by means of muon-spin-rotation experiments. The corresponding OIE exponents were found to be α_{T_{so}}=-0.57(6) and α_{V_{m}}=-0.71(9), which are sign reversed to α_{T_{c}}=0.46(6) measured for the superconducting transition temperature T_{c}. This indicates that the electron-lattice interaction is involved in the stripe formation and plays an important role in the competition between bulk superconductivity and static stripe order in the cuprates.

  17. Modeling the Ionosphere with GPS and Rotation Measure Observations

    Science.gov (United States)

    Malins, J. B.; Taylor, G. B.; White, S. M.; Dowell, J.

    2017-12-01

    Advances in digital processing have created new tools for looking at and examining the ionosphere. We have combined data from dual frequency GPSs, digital ionosondes and observations from The Long Wavelength Array (LWA), a 256 dipole low frequency radio telescope situated in central New Mexico in order to examine ionospheric profiles. By studying polarized pulsars, the LWA is able to very accurately determine the Faraday rotation caused by the ionosphere. By combining this data with the international geomagnetic reference field, the LWA can evaluate ionospheric profiles and how well they predict the actual Faraday rotation. Dual frequency GPS measurements of total electron content, as well as measurements from digisonde data were used to model the ionosphere, and to predict the Faraday rotation to with in 0.1 rad/m2. Additionally, it was discovered that the predicted topside profile of the digisonde data did not accurate predict faraday rotation measurements, suggesting a need to reexamine the methods for creating the topside predicted profile. I will discuss the methods used to measure rotation measure and ionosphere profiles as well as discuss possible corrections to the topside model.

  18. Comparison of Theory with Rotation Measurements in JET ICRH Plasmas

    International Nuclear Information System (INIS)

    R.V. Budny; C.S. Chang; C. Giroud; R.J. Goldston; D. McCune; J. Ongena; F.W. Perkins; R.B. White; K.-D. Zastrow; and contributors to the EFDA-JET work programme

    2001-01-01

    Plasma rotation appears to improve plasma performance by increasing the E x B flow shearing rate, thus decreasing radial correlations in the microturbulence. Also, plasma rotation can increase the stability to resistive MHD modes. In the Joint European Torus (JET), toroidal rotation rates omega (subscript ''tor'') with high Mach numbers are generally measured in NBI-heated plasmas (since the neutral beams aim in the co-plasma current direction). They are considerably lower with only ICRH (and Ohmic) heating, but still surprisingly large considering that ICRH appears to inject relatively small amounts of angular momentum. Either the applied torques are larger than naively expected, or the anomalous transport of angular momentum is smaller than expected. Since ICRH is one of the main candidates for heating next-step tokamaks, and for creating burning plasmas in future tokamak reactors, this paper attempts to understand ICRH-induced plasma rotation

  19. Magnetism of unconventional nanoscaled materials. An X-ray circular dichroism and muon spin rotation study

    International Nuclear Information System (INIS)

    Tietze, Thomas Hermann

    2014-01-01

    significant shape dependence was observed. This part of the thesis provides a microscopic understanding of the electronic and magnetic properties of Ni nanocluster on graphene and the cluster/graphene interaction. The resulting strong change in the Ni d states is very important concerning the choice of suitable materials for graphene based spintronic devices. The second part of this thesis is dedicated to the indirect influence of the nanoparticle size on the magnetic properties of an oxide system. In particular the origin of ferromagnetism in actual nonmagnetic ZnO is discussed. The reason for ferromagnetism in ZnO depends strongly on its microscopic properties. Nanocrystalline samples with adequate small grains are mandatory. The key parameter is the so called specific grain boundary area which is defined as ratio of grain surface to grain volume. If this value exceeds a certain threshold limit, ZnO can become ferromagnetic even without doping atoms. Here the ferromagnetic coupling is suggested to occur within the grain boundaries itself. A direct proof of this hypothesis is difficult. Measurement methods like SQUID do not provide information on the microscopic origin of the sample magnetization. Therefore, this problem was addressed using low energy muon spin rotation (μSR). Here, the magnetic moment of the muon is utilized as a local magnetic probe. Three different sample systems were investigated, varying the respective grain size. Two nanograined samples with an average grain size of 31 nm and 65 nm were compared to a nonmagnetic reference ZnO single crystal. A detailed TEM analysis of the grain size distribution showed that in both nanograined samples a significant fraction of grains is smaller than the threshold condition. SQUID and μSR measurements show a clear relation between magnetization respectively magnetic volume fraction and the sample volume occupied by grain boundaries. For larger grain boundary volume a larger saturation magnetization and μSR related

  20. Preclinical Arterial Spin Labeling Measurement of Cerebral Blood Flow.

    Science.gov (United States)

    Muir, Eric R

    2018-01-01

    Magnetic resonance imaging has been utilized as a quantitative and noninvasive method to image blood flow. Arterial spin labeling (ASL) is an MRI technique that images blood flow using arterial blood water as an endogenous tracer. Herein we describe the use of ASL to measure cerebral blood flow completely noninvasively in rodents, including methods, analysis, and important considerations when utilizing this technique.

  1. Theory of Faraday rotation beatings in quantum wells with great value of spin splitting

    CERN Document Server

    Gridnev, V N

    2001-01-01

    The conductivity electrons spin dynamics in the semiconducting heterostructures when the spin splitting value exceeds the energy levels widening due to collisions is theoretically studied. It is shown that the spin density component normal to the quantum well planes may oscillate with time even by absence of the external magnetic field. These oscillations might be excited and registered through the method of the nonlinear two-pulse spectroscopy. In contrast to the small spin splitting the external cross-sectional magnetic field strongly effects the spin dynamics in this mode

  2. np elastic spin transfer measurements at 788 MeV

    International Nuclear Information System (INIS)

    McNaughton, M.W.; Koch, K.; Supek, I.; Tanaka, N.; McNaughton, K.H.; Riley, P.J.; Ambrose, D.A.; Johnson, J.D.; Smith, A.; Glass, G.; Hiebert, J.C.; Northcliffe, L.C.; Simon, A.J.; Adams, D.L.; Ransome, R.D.; Clayton, D.B.; Spinka, H.M.; Jeppeson, R.H.; Tripard, G.E.

    1991-01-01

    We have measured the spin-transfer parameters K LL , K SL , K LS , and K SS at 788 MeV from 47 degree to 177 degree c.m., and also uncovered a 10--16 % normalization discrepancy which affects all previous np elastic spin data from LAMPF. Results disagree significantly from previous phase-shift predictions. With the inclusion of these new data the NN phase shifts and amplitudes (isospin 0 and 1) become well determined for the first time near 800 MeV

  3. New Limits on Extragalactic Magnetic Fields from Rotation Measures

    Science.gov (United States)

    Pshirkov, M. S.; Tinyakov, P. G.; Urban, F. R.

    2016-05-01

    We take advantage of the wealth of rotation measures data contained in the NRAO VLA Sky Survey catalog to derive new, statistically robust, upper limits on the strength of extragalactic magnetic fields. We simulate the extragalactic magnetic field contribution to the rotation measures for a given field strength and correlation length, by assuming that the electron density follows the distribution of Lyman-α clouds. Based on the observation that rotation measures from distant radio sources do not exhibit any trend with redshift, while the extragalactic contribution instead grows with distance, we constrain fields with Jeans' length coherence length to be below 1.7 nG at the 2 σ level, and fields coherent across the entire observable Universe below 0.65 nG. These limits do not depend on the particular origin of these cosmological fields.

  4. Spin Measurements of an Electron Bound to a Single Phosphorous Donor in Silicon

    Science.gov (United States)

    Luhman, D. R.; Nguyen, K.; Tracy, L. A.; Carr, S. M.; Borchardt, J.; Bishop, N. C.; Ten Eyck, G. A.; Pluym, T.; Wendt, J.; Carroll, M. S.; Lilly, M. P.

    2014-03-01

    The spin of an electron bound to a single donor implanted in silicon is potentially useful for quantum information processing. We report on our efforts to measure and manipulate the spin of an electron bound to a single P donor in silicon. A low number of P donors are implanted using a self-aligned process into a silicon substrate in close proximity to a single-electron-transistor (SET) defined by lithographically patterned polysilicon gates. The SET is used to sense the occupancy of the electron on the donor and for spin read-out. An adjacent transmission line allows the application of microwave pulses to rotate the spin of the electron. We will present data from various experiments designed to exploit these capabilities. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  5. Innovative Measurement Diagnostics for Analysis of Jet Interactions in Rotating Flowfields; TOPICAL

    International Nuclear Information System (INIS)

    AMATUCCI, VINCENT A.; BERESH, STEVEN J.; HENFLING, JOHN F.; ERVEN, ROCKY J.; BOURDON, CHRIS J.

    2002-01-01

    The present document summarizes the experimental efforts of a three-year study funded under the Laboratory Directed Research and Development program of Sandia National Laboratories. The Innovative Diagnostics LDRD project was designed to develop new measurement capabilities to examine the interaction of a propulsive spin jet in a transonic freestream for a model in a wind tunnel. The project motivation was the type of jet/fin interactions commonly occurring during deployment of weapon systems. In particular, the two phenomena of interest were the interaction of the propulsive spin jet with the freestream in the vicinity of the nozzle and the impact of the spin rocket plume and its vortices on the downstream fins. The main thrust of the technical developments was to incorporate small-size, Lagrangian sensors for pressure and roll-rate on a scale model and include data acquisition, transmission, and power circuitry onboard. FY01 was the final year of the three-year LDRD project and the team accomplished much of the project goals including use of micron-scale pressure sensors, an onboard telemetry system for data acquisition and transfer, onboard jet exhaust, and roll-rate measurements. A new wind tunnel model was designed, fabricated, and tested for the program which incorporated the ability to house multiple MEMS-based pressure sensors, interchangeable vehicle fins with pressure instrumentation, an onboard multiple-channel telemetry data package, and a high-pressure jet exhaust simulating a spin rocket motor plume. Experiments were conducted for a variety of MEMS-based pressure sensors to determine performance and sensitivity in order to select pressure transducers for use. The data acquisition and analysis path was most successful by using multiple, 16-channel data processors with telemetry capability to a receiver outside the wind tunnel. The development of the various instrumentation paths led to the fabrication and installation of a new wind tunnel model for

  6. Comparison between muon spin rotation and neutron scattering studies on the 3-dimensional magnetic ordering of La2CuO(4-y)

    Science.gov (United States)

    Uemura, Y. J.; Kossler, W. J.; Kempton, J. R.; Yu, X. H.; Schone, H. E.; Opie, D.; Stronach, C. E.; Brewer, J. H.; Kiefl, R. F.; Kreitzman, S. R.

    1988-01-01

    Muon spin rotation and neutron scattering studies on powder and single-crystal specimens of La2CuO(4-y) are compared. The apparent difference between the muon and neutron results for the ordered moment in the antiferromagnetic state is interpreted as the signature of increasingly short-ranged spatial spin correlations with increasing oxygen content.

  7. Radiographic femoral varus measurement is affected unpredictably by femoral rotation

    DEFF Research Database (Denmark)

    Miles, James Edward

    Radiographic measurements of femoral varus are used to determine if intervention to correct femoral deformity is required, and to calculate the required correction. The varus angle is defined as the angle between the proximal femoral long axis (PFLA) and an axis tangential to the distal femoral...... condyles. Ideal positioning of the femur in terms of zero elevation relative to the radiographic plane or zero rotation along the long axis of the femur may be difficult to obtain in practice. The clinician may thus be tempted to determine varus values from less than ideal radiographs. Fourteen isolated...... and externally by 5° and 10° using plastic wedges. Accuracy of rotation was within +1°. Digital radiographs were obtained at each position. Varus angles were measured using ImageJ, employing two definitions of PFLA. Mean varus angles increased with 10° of either internal or external rotation with both PFLA...

  8. Measuring unbalance-induced vibrations in rotating tools

    Directory of Open Access Journals (Sweden)

    Kimmelmann Martin

    2017-01-01

    Full Text Available Unbalances in a tool cause vibrations of the spindle and the machine itself and lead to a waviness of the machined workpiece surface. This paper presents an experimental and analytical procedure for optically measuring the unbalance-induced displacements of the tool centre point (TCP. Therefore, a new method is introduced to determine the dynamic vibrations of a tool by comparing the geometrical profile of the tool with the dynamical profile at a high rotational speed. The necessary steps for measuring the signals and calculating the underlying dynamic vibrations of the tool are presented here. Afterwards, the unbalance-induced vibrations of a milling tool are shown as well as their influence on the eccentricity of the rotation axis. With this newly introduced method it is possible to directly link the displacements of the tool under rotation to the waviness of the workpiece surface and the dynamic stiffness of machine tools.

  9. Keeping It in Three Dimensions: Measuring the Development of Mental Rotation in Children with the Rotated Colour Cube Test (RCCT)

    Science.gov (United States)

    Lutke, Nikolay; Lange-Kuttner, Christiane

    2015-01-01

    This study introduces the new Rotated Colour Cube Test (RCCT) as a measure of object identification and mental rotation using single 3D colour cube images in a matching-to-sample procedure. One hundred 7- to 11-year-old children were tested with aligned or rotated cube models, distracters and targets. While different orientations of distracters…

  10. You Spin my Head Right Round: Threshold of Limited Immersion for Rotation Gains in Redirected Walking.

    Science.gov (United States)

    Schmitz, Patric; Hildebrandt, Julian; Valdez, Andre Calero; Kobbelt, Leif; Ziefle, Martina

    2018-04-01

    In virtual environments, the space that can be explored by real walking is limited by the size of the tracked area. To enable unimpeded walking through large virtual spaces in small real-world surroundings, redirection techniques are used. These unnoticeably manipulate the user's virtual walking trajectory. It is important to know how strongly such techniques can be applied without the user noticing the manipulation-or getting cybersick. Previously, this was estimated by measuring a detection threshold (DT) in highly-controlled psychophysical studies, which experimentally isolate the effect but do not aim for perceived immersion in the context of VR applications. While these studies suggest that only relatively low degrees of manipulation are tolerable, we claim that, besides establishing detection thresholds, it is important to know when the user's immersion breaks. We hypothesize that the degree of unnoticed manipulation is significantly different from the detection threshold when the user is immersed in a task. We conducted three studies: a) to devise an experimental paradigm to measure the threshold of limited immersion (TLI), b) to measure the TLI for slowly decreasing and increasing rotation gains, and c) to establish a baseline of cybersickness for our experimental setup. For rotation gains greater than 1.0, we found that immersion breaks quite late after the gain is detectable. However, for gains lesser than 1.0, some users reported a break of immersion even before established detection thresholds were reached. Apparently, the developed metric measures an additional quality of user experience. This article contributes to the development of effective spatial compression methods by utilizing the break of immersion as a benchmark for redirection techniques.

  11. Searching for Excess Rotation Measures in Galaxy Clusters with the ...

    Indian Academy of Sciences (India)

    2016-01-27

    ://www.ias.ac.in/article/fulltext/joaa/032/04/0539-0540 ... Despite that it is now well established that galaxy clusters contain magnetic fields, we find no evidence of an increase of the rotation measure for lines of sight toward ...

  12. A Circular Statistical Method for Extracting Rotation Measures

    Indian Academy of Sciences (India)

    Abstract. We propose a new method for the extraction of Rotation Measures from spectral polarization data. The method is based on maximum likelihood analysis and takes into account the circular nature of the polarization data. The method is unbiased and statistically more efficient than the standard 2 procedure.

  13. A Circular Statistical Method for Extracting Rotation Measures

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    where RM is the Rotation Measure and θ0 is the intrinsic position angle of polarization. (IPA). The extraction of RM is ambiguous since the observed polarization is defined only up to additions of nπ, where n is an integer. In the present paper we propose an alternate method for the extraction of RM and. IPA from data.

  14. Muon spin rotation and neutron scattering study of the noncentrosymmetric tetragonal compound CeAuAl3

    Science.gov (United States)

    Adroja, D. T.; de la Fuente, C.; Fraile, A.; Hillier, A. D.; Daoud-Aladine, A.; Kockelmann, W.; Taylor, J. W.; Koza, M. M.; Burzurí, E.; Luis, F.; Arnaudas, J. I.; del Moral, A.

    2015-04-01

    We have investigated the noncentrosymmetric tetragonal heavy fermion compound CeAuA l3 using muon spin rotation (μ SR ), neutron diffraction (ND), and inelastic neutron scattering (INS) measurements. We have also revisited the magnetic, transport, and thermal properties. The magnetic susceptibility reveals an antiferromagnetic transition at 1.1 K with, possibly, another magnetic transition near 0.18 K. The heat capacity shows a sharp λ -type anomaly at 1.1 K in zero field, which broadens and moves to a higher temperature in an applied magnetic field. Our zero-field μ SR and ND measurements confirm the existence of a long-range magnetic ground state below 1.2 K. Further, the ND study reveals an incommensurate magnetic order with a magnetic propagation vector k =( 0 , 0 , 0.52 (1 )) and a spiral structure of Ce moments coupled ferromagnetically within the a b plane. Our INS study reveals the presence of two well-defined crystal electric field (CEF) excitations at 5.1 and 24.6 meV in the paramagnetic phase of CeAuA l3 that can be explained on the basis of the CEF theory and the Kramer's theorem for a Ce ion having a 4 f1 electronic state. Furthermore, low energy quasielastic excitations show a Gaussian line shape below 30 K compared to a Lorentzian line shape above 30 K, indicating a slowdown of spin fluctuations below 30 K. We have estimated a Kondo temperature of TK=3.5 K from the quasielastic linewidth, which is in good agreement with that estimated from the heat capacity. This study also indicates the absence of any CEF-phonon coupling unlike that observed in isostructural CeCuA l3 The CEF parameters, energy level scheme, and their wave functions obtained from the analysis of INS data explain satisfactorily the single crystal susceptibility in the presence of two-ion anisotropic exchange interaction in CeAuA l3 .

  15. A Near Perfect Spin Balance (Measurement in Chaos)

    Science.gov (United States)

    Luntz, R. A.

    1997-01-01

    The stringent spin balance requirements arise from the predecessor of SSMIS, the SSMI. The SSMI sensor spinning portion weighed only 85 pounds and contained 7 channels of radiometric data. The Aerospace Corporation recommended to pass on the same requirements from the smaller SSMI to our larger SSMIS (with slight change for increased weight). The SSMIS spinning portion will weigh about 155 pounds and contain 24 channels of radiometeric data. The SSMIS, on orbit, spins a CCW direction at 31.6 RPM its own drive motor. The packaging of this SSMIS is unique, as it combines three sensor into one unit. This combination allows for concurrently reading data in one beam. The unit will have a polar orbit about 500 miles above the earths surface. One of the primary influences for our receipt of the follow-on contract for the next generation sensor, was the ability to package 24 channels of radiometeric data into about the some volume as its predecessor. The data from SSMIS will be used to measure the following: (1) Ocean surface wind speed, (2) Rain over land an ocean, (3) Cloud water over Ocean, (4) Soil moisture, (5) Ice Concentration, (6) Ice age, (7) Ice Edge and snow edge, (8) Water vapor over Ocean, (9) Surface type, (10) Snow water content, (11) Land surface Temperature, (12) Cloud amount over ocean.

  16. Vortex motion in type II superconductors probed by muon spin rotation and SANS

    Science.gov (United States)

    Forgan, E. M.; Charalambous, D.; Kealey, P. G.; King, P. J. C.; Khasanov, R.; Amato, A.

    2003-02-01

    We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low Tc type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the alignment by motion of the nearest-neighbour FLL direction. This tends to be parallel to the direction of flux line motion, as had been suspected from two-dimensional simulations. We also see the destruction of the ordered FLL by plastic flow and the bending of flux lines. Another technique that our collaboration has employed is the direct measurement of flux line motion, using the ultra-high-resolution spectroscopy of the neutron spin-echo technique to observe the energy change of neutrons diffracted by moving flux lines. The μSR technique gives the distribution of values of magnetic field within the FLL. We have recently shown that one can perform μSR measurements while the FLL is moving. Such measurements give complementary information about the local speed and orientation of the FLL motion. We conclude by discussing the possible application of this technique to thin film superconductors.

  17. Vortex motion in type II superconductors probed by muon spin rotation and SANS

    International Nuclear Information System (INIS)

    Forgan, E.M.; Charalambous, D.; Kealey, P.G.; King, P.J.C.; Khasanov, R.; Amato, A.

    2003-01-01

    We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low T c type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the alignment by motion of the nearest-neighbour FLL direction. This tends to be parallel to the direction of flux line motion, as had been suspected from two-dimensional simulations. We also see the destruction of the ordered FLL by plastic flow and the bending of flux lines. Another technique that our collaboration has employed is the direct measurement of flux line motion, using the ultra-high-resolution spectroscopy of the neutron spin-echo technique to observe the energy change of neutrons diffracted by moving flux lines. The μSR technique gives the distribution of values of magnetic field within the FLL. We have recently shown that one can perform μSR measurements while the FLL is moving. Such measurements give complementary information about the local speed and orientation of the FLL motion. We conclude by discussing the possible application of this technique to thin film superconductors

  18. Measuring exchange interactions between atomic spins using electron spin resonance STM

    Science.gov (United States)

    Yang, Kai; Paul, William; Natterer, Fabian; Choi, Taeyoung; Heinrich, Andreas; Lutz, Christopher

    Exchange interactions between neighboring atoms give rise to magnetic order in magnetic materials. As the size of the electronic device is miniaturized toward the limit of single atoms, magnetic nanostructures such as coupled atomic dimers and clusters are explored more as prototypes for possible data storage, spintronics as well as quantum computing applications. Characterizing inter-atom exchange interactions calls for increasing spatial resolution and higher energy sensitivity to better understand this fundamental interaction. Here, using spin-polarized scanning tunneling microscopy (STM), we studied a magnetically coupled atomic dimer consisting of two 3d transition metal atoms, with one adsorbed on an insulating layer (MgO) and the other attached to the STM tip. We demonstrate the ability to measure the short-range exchange interaction between the two atomic spins with orders-of-magnitude variation ranging from milli-eV all the way to micro-eV. This is realized by the successful combination of inelastic electron tunneling spectroscopy (IETS) and electron spin resonance (ESR) techniques in STM implemented at different energy scales. We unambiguously confirm the exponential decay behavior of the direct exchange interaction.

  19. Photometric Amplitude Distribution of Stellar Rotation of KOIs—Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars

    Science.gov (United States)

    Mazeh, Tsevi; Perets, Hagai B.; McQuillan, Amy; Goldstein, Eyal S.

    2015-03-01

    The observed amplitude of the rotational photometric modulation of a star with spots should depend on the inclination of its rotational axis relative to our line of sight. Therefore, the distribution of observed rotational amplitudes of a large sample of stars depends on the distribution of their projected axes of rotation. Thus, comparison of the stellar rotational amplitudes of the Kepler objects of interest (KOIs) with those of Kepler single stars can provide a measure to indirectly infer the properties of the spin-orbit obliquity of Kepler planets. We apply this technique to the large samples of 993 KOIs and 33,614 single Kepler stars in temperature range of 3500-6500 K. We find with high significance that the amplitudes of cool KOIs are larger, on the order of 10%, than those of the single stars. In contrast, the amplitudes of hot KOIs are systematically lower. After correcting for an observational bias, we estimate that the amplitudes of the hot KOIs are smaller than the single stars by about the same factor of 10%. The border line between the relatively larger and smaller amplitudes, relative to the amplitudes of the single stars, occurs at about 6000 K. Our results suggest that the cool stars have their planets aligned with their stellar rotation, while the planets around hot stars have large obliquities, consistent with the findings of Winn et al. and Albrecht et al. We show that the low obliquity of the planets around cool stars extends up to at least 50 days, a feature that is not expected in the framework of a model that assumes the low obliquity is due to planet-star tidal realignment.

  20. Electron Spin Resonance Measurement with Microinductor on Chip

    Directory of Open Access Journals (Sweden)

    Akio Kitagawa

    2011-01-01

    Full Text Available The detection of radicals on a chip is demonstrated. The proposed method is based on electron spin resonance (ESR spectroscopy and the measurement of high-frequency impedance of the microinductor fabricated on the chip. The measurement was by using a frequency sweep of approximately 100 MHz. The ESR spectra of di(phenyl-(2,4,6-trinitrophenyliminoazanium (DPPH dropped on the microinductor which is fabricated with CMOS 350-nm technology were observed at room temperature. The volume of the DPPH ethanol solution was 2 μL, and the number of spins on the micro-inductor was estimated at about 1014. The sensitivity is not higher than that of the standard ESR spectrometers. However, the result indicates the feasibility of a near field radical sensor in which the microinductor as a probe head and ESR signal processing circuit are integrated.

  1. Nonlocal spin-transport measurement of superconductor-ferromagnet nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kolenda, Stefan; Wolf, Michael J.; Huebler, Florian; Beckmann, Detlef [Institut fuer Nanotechnologie, Karlsruher Institut fuer Technologie (Germany)

    2015-07-01

    We present measurements of the nonlocal conductance of nanostructures with several ferromagnetic electrodes lying perpendicular on a superconducting wire. In these structures nonlocal conductance is mostly given by diffusion of quasiparticles, which are injected by one of the electrodes and detected by an other one. Applying a magnetic field induces a Zeeman splitting in the quasiparticles density of states, which suppresses the relaxation of injected spin imbalance, thus spin transport over distances of several micrometers is found. While in the previous experiments the magnetic field was aligned parallel to the ferromagnetic electrodes, we also show measurements applying the magnetic field noncollinear with the magnetization of the ferromagnetic electrodes. We compare our results to the previous case.

  2. Ferromagnetic domain structures and spin configurations measured in doped manganite

    DEFF Research Database (Denmark)

    He, J.Q.; Volkov, V.V.; Beleggia, Marco

    2010-01-01

    We report on measurements of the spin configuration across ferromagnetic domains in La0.325Pr0.3Ca0.375MnO3 films obtained by means of low-temperature Lorentz electron microscopy with in situ magnetizing capabilities. Due to the particular crystal symmetry of the material, we observe two sets of ...... and the crystal symmetry might affect the magnetoresistivity under an applied magnetic field in a strongly correlated electron system....

  3. Recent VLA Measurements of CME-Induced Faraday Rotation

    Science.gov (United States)

    Kooi, Jason; Thomas, Najma; Guy, Michael; Spangler, Steven R.

    2018-01-01

    Observations of Faraday rotation, the change in polarization position angle of linearly polarized radiation as it propagates through a magnetized plasma, have been used for decades to determine the strength and structure of the coronal magnetic field and plasma density. Similarly, observations of Faraday rotation through a coronal mass ejection (CME) have the potential to improve our understanding of the CME’s plasma structure. We report recent results from simultaneous white-light coronagraph and radio observations made of a CME in July 2015. We made radio observations using the Karl G. Jansky Very Large Array (VLA) at 1 - 2 GHz frequencies of a set of cosmic radio sources through the solar corona at heliocentric distances that ranged between 8 - 23 solar radii. A unique aspect of these observations is that the CME occulted several of these radio sources and, therefore, our Faraday rotation measurements provide information on the plasma structure in different regions of the CME. We successfully measured CME-induced Faraday rotation along multiple lines of sight because we made special arrangements with the staff at the National Radio Astronomy Observatory to trigger VLA observations when a candidate CME appeared low in the corona in near real-time images from the Large Angle and Spectrometric Coronagraph (LASCO) C2 instrument.

  4. Measuring students' approaches to learning in different clinical rotations.

    Science.gov (United States)

    Emilia, Ova; Bloomfield, Leah; Rotem, Arie

    2012-11-15

    Many studies have explored approaches to learning in medical school, mostly in the classroom setting. In the clinical setting, students face different conditions that may affect their learning. Understanding students' approaches to learning is important to improve learning in the clinical setting. The aim of this study was to evaluate the Study Process Questionnaire (SPQ) as an instrument for measuring clinical learning in medical education and also to show whether learning approaches vary between rotations. All students involved in this survey were undergraduates in their clinical phase. The SPQ was adapted to the clinical setting and was distributed in the last week of the clerkship rotation. A longitudinal study was also conducted to explore changes in learning approaches. Two hundred and nine students participated in this study (response rate 82.0%). The SPQ findings supported a two-factor solution involving deep and surface approaches. These two factors accounted for 45.1% and 22.5%, respectively, of the variance. The relationships between the two scales and their subscales showed the internal consistency and factorial validity of the SPQ to be comparable with previous studies. The clinical students in this study had higher scores for deep learning. The small longitudinal study showed small changes of approaches to learning with different rotation placement but not statistically significant. The SPQ was found to be a valid instrument for measuring approaches to learning among clinical students. More students used a deep approach than a surface approach. Changes of approach not clearly occurred with different clinical rotations.

  5. Counter-rotating standing spin waves: A magneto-optical illusion

    Science.gov (United States)

    Shihab, S.; Thevenard, L.; Lemaître, A.; Gourdon, C.

    2017-04-01

    We excite perpendicular standing spin waves by a laser pulse in a GaMnAsP ferromagnetic layer and detect them using time-resolved magneto-optical effects. Quite counterintuitively, we find the first two excited modes to be of opposite chirality. We show that this can only be explained by taking into account absorption and optical phase shift inside the layer. This optical illusion is particularly strong in weakly absorbing layers. These results provide a correct identification of spin waves modes, enabling a trustworthy estimation of their respective weight as well as an unambiguous determination of the spin stiffness parameter.

  6. A low energy muon spin rotation and point contact tunneling study of niobium films prepared for superconducting cavities

    Science.gov (United States)

    Junginger, Tobias; Calatroni, S.; Sublet, A.; Terenziani, G.; Prokscha, T.; Salman, Z.; Suter, A.; Proslier, T.; Zasadzinski, J.

    2017-12-01

    Point contact tunneling and low energy muon spin rotation are used to probe, on the same samples, the surface superconducting properties of micrometer thick niobium films deposited onto copper substrates using different sputtering techniques: diode, dc magnetron and HIPIMS. The combined results are compared to radio-frequency tests performances of RF cavities made with the same processes. Degraded surface superconducting properties are found to correlate to lower quality factors and stronger Q-slope. In addition, both techniques find evidence for surface paramagnetism on all samples and particularly on Nb films prepared by HIPIMS.

  7. A slowly rotating hollow sphere in a magnetic field: First steps to de-spin a space object

    Science.gov (United States)

    Youngquist, Robert C.; Nurge, Mark A.; Starr, Stanley O.; Leve, Frederick A.; Peck, Mason

    2016-03-01

    Modeling the interaction of a slowly rotating hollow conducting sphere in a magnetic field provided an understanding of the dynamics of orbiting space objects moving through the Earth's magnetic field. This analysis, performed in the late 1950s and limited to uniform magnetic fields, was innovative and acknowledged the pioneers who first observed rotary magnetism, in particular, the seminal work of Hertz in 1880. Now, there is interest in using a magnetic field produced by one space object to stop the spin of a second object so that docking can occur. In this paper, we consider, yet again, the interaction of a rotating hollow sphere in a magnetic field. We show that the predicted results can be tested experimentally, making this an interesting advanced student project. This analysis also sheds light on a rich set of previously unaddressed behaviors involving eddy currents.

  8. Birefringent neutron prisms for spin echo scattering angle measurement

    Science.gov (United States)

    Pynn, Roger; Fitzsimmons, M. R.; Lee, W. T.; Stonaha, P.; Shah, V. R.; Washington, A. L.; Kirby, B. J.; Majkrzak, C. F.; Maranville, B. B.

    2009-09-01

    In the first decade of the 19th century, an English chemist, William Wollaston, invented an arrangement of birefringent prisms that splits a beam of light into two spatially separated beams with orthogonal polarizations. We have constructed similar devices for neutrons using triangular cross-section solenoids and employed them for Spin Echo Scattering Angle Measurement (SESAME). A key difference between birefringent neutron prisms and their optical analogues is that it is hard to embed the former in a medium which has absolutely no birefringence because this implies the removal of all magnetic fields. We have overcome this problem by using the symmetry properties of the Wollaston neutron prisms and of the overall spin echo arrangement. These symmetries cause a cancellation of Larmor phase aberrations and provide robust coding of neutron scattering angles with simple equipment.

  9. Earth rotation measurement with micromechanical yaw-rate gyro

    Science.gov (United States)

    Arnaudov, Rumen; Angelov, Yasen

    2005-11-01

    The direct measurement of the Earth's rotation rate by means of a micromechanical yaw-rate gyroscope is difficult to achieve due to the considerable parameter variations of the current state-of-the-art sensors of this type. This paper outlines and applies a model of the external factors' effect on the sensor measurement via a method for their compensation through a mechanical change in the sensor's orientation. This allows the determination of a value such as the Earth's rotation rate, which is at the limit of the sensor's sensitivity and less than its short-term stability. A specialized information-measurement system has been developed for the implementation of the method. This system has been used for a number of measurements, presented in a graphical form. As a result, an average value of the Earth's rotation rate has been derived. This method is applicable for a subjective categorization and evaluation of micromechanical gyroscopes using a natural source of a very low angular speed.

  10. Possible Measurable Effects of Dark Energy in Rotating Superconductors

    Directory of Open Access Journals (Sweden)

    Clovis Jacinto de Matos

    2009-01-01

    Full Text Available We discuss recent laboratory experiments with rotating superconductors and show that three so far unexplained experimentally observed effects (anomalous acceleration signals, anomalous gyroscope signals, Cooper pair mass excess can be physically explained in terms of a possible interaction of dark energy with Cooper pairs. Our approach is based on a Ginzburg-Landau-like model of electromagnetic dark energy, where gravitationally active photons obtain mass in the superconductor. We show that this model can account simultaneously for the anomalous acceleration and anomalous gravitomagnetic fields around rotating superconductors measured by Tajmar et al. and for the anomalous Cooper pair mass in superconductive Niobium, measured by Cabrera and Tate. It is argued that these three different physical effects are ultimately different experimental manifestations of the simultaneous spontaneous breaking of gauge invariance and of the principle of general covariance in superconductive materials.

  11. Faraday rotation measurements in maghemite-silica aerogels

    International Nuclear Information System (INIS)

    Taboada, E.; Real, R.P. del; Gich, M.; Roig, A.; Molins, E.

    2006-01-01

    Faraday rotation measurements have been performed on γ-Fe 2 O 3 /SiO 2 nanocomposite aerogels which are light, porous and transparent magnetic materials. The materials have been prepared by sol-gel polymerization of a silicon alkoxide, impregnation of the intermediate silica gel with a ferrous salt and supercritical drying of the gels. During supercritical evacuation of the solvent, spherical nanoparticles of iron oxide, with a mean particle diameter of 8.1±2.0 nm, are formed and are found to be homogenously distributed within the silica matrix. The specific Faraday rotation of the composite was measured at 0.6 T using polarized light of 810 nm, being 29.6 deg./cm. The changes in the plane of polarization of the transmitted light and the magnetization of the material present similar magnetic field dependencies and are characteristic of a superparamagnetic system

  12. Rotating permanent magnet excitation for blood flow measurement.

    Science.gov (United States)

    Nair, Sarath S; Vinodkumar, V; Sreedevi, V; Nagesh, D S

    2015-11-01

    A compact, portable and improved blood flow measurement system for an extracorporeal circuit having a rotating permanent magnetic excitation scheme is described in this paper. The system consists of a set of permanent magnets rotating near blood or any conductive fluid to create high-intensity alternating magnetic field in it and inducing a sinusoidal varying voltage across the column of fluid. The induced voltage signal is acquired, conditioned and processed to determine its flow rate. Performance analysis shows that a sensitivity of more than 250 mV/lpm can be obtained, which is more than five times higher than conventional flow measurement systems. Choice of rotating permanent magnet instead of an electromagnetic core generates alternate magnetic field of smooth sinusoidal nature which in turn reduces switching and interference noises. These results in reduction in complex electronic circuitry required for processing the signal to a great extent and enable the flow measuring device to be much less costlier, portable and light weight. The signal remains steady even with changes in environmental conditions and has an accuracy of greater than 95%. This paper also describes the construction details of the prototype, the factors affecting sensitivity and detailed performance analysis at various operating conditions.

  13. Muon spin-relaxation measurements of spin-correlation decay in spin-glass AgMn

    International Nuclear Information System (INIS)

    Heffner, R.H.; Cooke, D.W.; Leon, M.; Schillaci, M.E.; MacLaughlin, D.E.; Gupta, L.C.

    1983-01-01

    The field (H) dependence of the muon longitudinal spin-lattice relaxation rate well below the spin-glass temperature in AgMn is found to obey an algebraic form given by (H)/sup nu-1/, with nu = 0.54 +- 0.05. This suggests that Mn spin correlations decay with time as t - /sup nu/, in agreement with mean field theories of spin-glass dynamics which yield nu less than or equal to 0.5. Near the glass temperature the agreement between the data and theory is not as good

  14. The structure of the Hoyle state via a measurement of the 'Hoyle Rotational Band' in 12C

    Science.gov (United States)

    Gai, M.; UConn-Yale-TUNL-Weizmann-PTB-UCL Collaboration

    2013-04-01

    We have measured the 12C(γ, 3α) reaction with an Optical Time Projection Chamber (O-TPC) detector operating with the CO2(80%) + N2(20%) gas mixture and gamma-ray beams from the HIγS facility of the TUNL at Duke. We measured complete angular distributions (between 9.1 - 10.7 MeV) from which we determine the cross section yield curve and E1-E2 relative phases leading to an unambiguous identification of the second 2+ state in 12C at 10.03(11) MeV. The observed spectrum of 12C below 12 MeV including the 2+2 observed in this work resembles the rotation-vibration spectrum predicted for a triangular shape oblate spinning top in which the Hoyle state is the first vibrational breathing mode of the triangular three alpha particle system. The predicted rotation-vibration spectrum of a triangular shape oblate spinning top (with a D3h symmetry) allows us to compare the moment of inertia of the predicted Hoyle rotational band to the ground state rotational band and in this way extract the model radius parameter of the Hoyle state of 3.22(8) fm ( time the r.m.s. radius of the ground state) which is close to the radius extracted from 12C(x,x') data.

  15. Faraday Rotation Measure Study of Cluster Magnetic Fields

    Science.gov (United States)

    Frankel, M. M.; Clarke, T. E.

    2001-12-01

    Magnetic fields are thought to play an important role in galaxy cluster evolution. To this end in this study, we looked at polarized radio sources viewed at small impact parameters to the cores of non-cooling flow clusters. By looking at non-cooling flow clusters we hoped to establish what magnetic fields of clusters look like in the absence of the compressed central magnetic fields of the cooling-flow cores. Clarke, Kronberg and Boehringer (2001) examined Faraday rotation measures of radio probes at relatively large impact parameters to the cores of galaxy clusters. The current study is an extension of the Clarke et al. analysis to probe the magnetic fields in the cores of galaxy clusters. We looked at the Faraday rotation of electromagnetic waves from background or imbedded radio galaxies, which were observed with the VLA in A&B arrays. Our results are consistent with previous findings and exhibit a trend towards higher rotation measures and in turn higher magnetic fields at small impact parameters to cluster cores. This research was made possible through funding from the National Science Foundation.

  16. Changes in the Earth’s Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

    Directory of Open Access Journals (Sweden)

    Sung-Ho Na

    2016-12-01

    Full Text Available The atmosphere strongly affects the Earth’s spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i the Earth orientation parameter and ii the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth’s spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth’s pole has been observed. The change in the Earth’s inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated.

  17. Measuring gas temperature during spin-exchange optical pumping process

    Science.gov (United States)

    Normand, E.; Jiang, C. Y.; Brown, D. R.; Robertson, L.; Crow, L.; Tong, X.

    2016-04-01

    The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.

  18. Measurement of the charge and current of magnetic monopoles in spin ice.

    Science.gov (United States)

    Bramwell, S T; Giblin, S R; Calder, S; Aldus, R; Prabhakaran, D; Fennell, T

    2009-10-15

    The transport of electrically charged quasiparticles (based on electrons or ions) plays a pivotal role in modern technology as well as in determining the essential functions of biological organisms. In contrast, the transport of magnetic charges has barely been explored experimentally, mainly because magnetic charges, in contrast to electric ones, are generally considered at best to be convenient macroscopic parameters, rather than well-defined quasiparticles. However, it was recently proposed that magnetic charges can exist in certain materials in the form of emergent excitations that manifest like point charges, or magnetic monopoles. Here we address the question of whether such magnetic charges and their associated currents-'magnetricity'-can be measured directly in experiment, without recourse to any material-specific theory. By mapping the problem onto Onsager's theory of electrolytes, we show that this is indeed possible, and devise an appropriate method for the measurement of magnetic charges and their dynamics. Using muon spin rotation as a suitable local probe, we apply the method to a real material, the 'spin ice' Dy(2)Ti(2)O(7) (refs 5-8). Our experimental measurements prove that magnetic charges exist in this material, interact via a Coulomb potential, and have measurable currents. We further characterize deviations from Ohm's law, and determine the elementary unit of magnetic charge to be 5 mu(B) A(-1), which is equal to that recently predicted using the microscopic theory of spin ice. Our measurement of magnetic charge and magnetic current establishes an instance of a perfect symmetry between electricity and magnetism.

  19. Measuring students’ approaches to learning in different clinical rotations

    Directory of Open Access Journals (Sweden)

    Emilia Ova

    2012-11-01

    Full Text Available Abstract Background Many studies have explored approaches to learning in medical school, mostly in the classroom setting. In the clinical setting, students face different conditions that may affect their learning. Understanding students’ approaches to learning is important to improve learning in the clinical setting. The aim of this study was to evaluate the Study Process Questionnaire (SPQ as an instrument for measuring clinical learning in medical education and also to show whether learning approaches vary between rotations. Methods All students involved in this survey were undergraduates in their clinical phase. The SPQ was adapted to the clinical setting and was distributed in the last week of the clerkship rotation. A longitudinal study was also conducted to explore changes in learning approaches. Results Two hundred and nine students participated in this study (response rate 82.0%. The SPQ findings supported a two-factor solution involving deep and surface approaches. These two factors accounted for 45.1% and 22.5%, respectively, of the variance. The relationships between the two scales and their subscales showed the internal consistency and factorial validity of the SPQ to be comparable with previous studies. The clinical students in this study had higher scores for deep learning. The small longitudinal study showed small changes of approaches to learning with different rotation placement but not statistically significant. Conclusions The SPQ was found to be a valid instrument for measuring approaches to learning among clinical students. More students used a deep approach than a surface approach. Changes of approach not clearly occurred with different clinical rotations.

  20. Antiferromagnetism of La2CuO(4-y) studied by muon-spin rotation

    Science.gov (United States)

    Uemura, Y. J.; Kossler, W. J.; Yu, X. H.; Kempton, J. R.; Schone, H. E.

    1987-01-01

    Zero-field spin precession of positive muons has been observed in the antiferromagnetic state of La2CuO(4-y). Sharp onsets of the sublattice magnetization are found at temperatures close to those of the susceptibility maxima of different specimens. The long-lived precession signal indicates a microscopically homogeneous distribution of spin density at each Cu atom below the Neel temperature. A combination of the present results and neutron-scattering studies indicates the ordered moment per Cu atom to be significantly less than 1 mu(B).

  1. Precision measurement of the neutron spin dependent structure functions

    International Nuclear Information System (INIS)

    Kolomensky, Y.G.

    1997-02-01

    In experiment E154 at the Stanford Linear Accelerator Center the spin dependent structure function g 1 n (x, Q 2 ) of the neutron was measured by scattering longitudinally polarized 48.3 GeV electrons off a longitudinally polarized 3 He target. The high beam energy allowed the author to extend the kinematic coverage compared to the previous SLAC experiments to 0.014 ≤ x ≤ 0.7 with an average Q 2 of 5 GeV 2 . The author reports the integral of the spin dependent structure function in the measured range to be ∫ 0.014 0.7 dx g 1 n (x, 5 GeV 2 ) = -0.036 ± 0.004(stat.) ± 0.005(syst.). The author observes relatively large values of g 1 n at low x that call into question the reliability of data extrapolation to x → 0. Such divergent behavior disagrees with predictions of the conventional Regge theory, but is qualitatively explained by perturbative QCD. The author performs a Next-to-Leading Order perturbative QCD analysis of the world data on the nucleon spin dependent structure functions g 1 p and g 1 n paying careful attention to the experimental and theoretical uncertainties. Using the parameterizations of the helicity-dependent parton distributions obtained in the analysis, the author evolves the data to Q 2 = 5 GeV 2 , determines the first moments of the polarized structure functions of the proton and neutron, and finds agreement with the Bjorken sum rule

  2. Precision measurement of the neutron spin dependent structure functions

    Energy Technology Data Exchange (ETDEWEB)

    Kolomensky, Y.G.

    1997-02-01

    In experiment E154 at the Stanford Linear Accelerator Center the spin dependent structure function g{sub 1}{sup n} (x, Q{sup 2}) of the neutron was measured by scattering longitudinally polarized 48.3 GeV electrons off a longitudinally polarized {sup 3}He target. The high beam energy allowed the author to extend the kinematic coverage compared to the previous SLAC experiments to 0.014 {le} x {le} 0.7 with an average Q{sup 2} of 5 GeV{sup 2}. The author reports the integral of the spin dependent structure function in the measured range to be {integral}{sub 0.014}{sup 0.7} dx g{sub 1}{sup n}(x, 5 GeV{sup 2}) = {minus}0.036 {+-} 0.004(stat.) {+-} 0.005(syst.). The author observes relatively large values of g{sub 1}{sup n} at low x that call into question the reliability of data extrapolation to x {r_arrow} 0. Such divergent behavior disagrees with predictions of the conventional Regge theory, but is qualitatively explained by perturbative QCD. The author performs a Next-to-Leading Order perturbative QCD analysis of the world data on the nucleon spin dependent structure functions g{sub 1}{sup p} and g{sub 1}{sup n} paying careful attention to the experimental and theoretical uncertainties. Using the parameterizations of the helicity-dependent parton distributions obtained in the analysis, the author evolves the data to Q{sup 2} = 5 GeV{sup 2}, determines the first moments of the polarized structure functions of the proton and neutron, and finds agreement with the Bjorken sum rule.

  3. Apparent rotation properties of space debris extracted from photometric measurements

    Science.gov (United States)

    Šilha, Jiří; Pittet, Jean-Noël; Hamara, Michal; Schildknecht, Thomas

    2018-02-01

    Knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. Different orbital regions and object's physical properties lead to different attitude states and their change over time. Since 2007 the Astronomical Institute of the University of Bern (AIUB) performs photometric measurements of space debris objects. To June 2016 almost 2000 light curves of more than 400 individual objects have been acquired and processed. These objects are situated in all orbital regions, from low Earth orbit (LEO), via global navigation systems orbits and high eccentricity orbit (HEO), to geosynchronous Earth orbit (GEO). All types of objects were observed including the non-functional spacecraft, rocket bodies, fragmentation debris and uncorrelated objects discovered during dedicated surveys. For data acquisition, we used the 1-meter Zimmerwald Laser and Astrometry Telescope (ZIMLAT) at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland. We applied our own method of phase-diagram reconstruction to extract the apparent rotation period from the light curve. Presented is the AIUB's light curve database and the obtained rotation properties of space debris as a function of object type and orbit.

  4. Predicting superdeformed rotational band-head spin in A ∼ 190 ...

    Indian Academy of Sciences (India)

    Table 1a. The band-head spin I0 of SD bands in A ≈ 190 region along with the calculated transition energy is given. The parameters, stiffness constant (C) and band- head moment of inertia Jo used in fitting are also given. The other theoretical model values which are available in literature are given for comparsion. A total ...

  5. Predicting superdeformed rotational band-head spin in A ∼ 190 ...

    Indian Academy of Sciences (India)

    head spin in. A ∼ 190 mass region using variable moment of inertia model. V S UMA1,∗, ALPANA GOEL2, ARCHANA YADAV2 and A K JAIN3 ..... [1] P J Twin, B M Nyako, A H Nelson, J Simpson, M A Bentley, J F Sharpey-Schafer and. G Sletten ...

  6. An Air Bearing Rotating Coil Magnetic Measurement System

    CERN Document Server

    Gottschalk, Stephen C; Taylor, David J; Thayer, William

    2005-01-01

    This paper describes a rotating coil magnetic measurement system supported on air bearings. The design is optimized for measurements of 0.1micron magnetic centerline changes on long, small aperture quadrupoles. Graphite impregnated epoxy resin is used for the coil holder and coil winding forms. Coil holder diameter is 11 mm with a length between supports of 750mm. A pair of coils is used to permit quadrupole bucking during centerline measurements. Coil length is 616mm, inner radius 1.82mm, outer radius 4.74mm. The key features of the mechanical system are simplicity; air bearings for accurate, repeatable measurements without needing warm up time and a vibration isolated stand that uses a steel-topped Newport optical table with air suspension. Coil rotation is achieved by a low noise servo motor controlled by a standalone Ethernet servo board running custom servo software. Coil calibration procedures that correct wire placement errors, tests for mechanical resonances, and other system checks will also be discu...

  7. Measurement of small light absorption in microparticles by means of optically induced rotation

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Bekshaev, A. Ya; Maksimyak, P. P.

    2015-01-01

    The absorption parameters of micro-particles have been associated with the induced spin exerted upon the particle, when embedded in a circularly polarized coherent field. The induced rotational speed is theoretically analyzed, showing the influence of the beam parameters, the parameters of the pa......The absorption parameters of micro-particles have been associated with the induced spin exerted upon the particle, when embedded in a circularly polarized coherent field. The induced rotational speed is theoretically analyzed, showing the influence of the beam parameters, the parameters...

  8. Primordial gravitational waves measurements and anisotropies of CMB polarization rotation

    Directory of Open Access Journals (Sweden)

    Si-Yu Li

    2015-12-01

    Full Text Available Searching for the signal of primordial gravitational waves in the B-modes (BB power spectrum is one of the key scientific aims of the cosmic microwave background (CMB polarization experiments. However, this could be easily contaminated by several foreground issues, such as the interstellar dust grains and the galactic cyclotron electrons. In this paper we study another mechanism, the cosmic birefringence, which can be introduced by a CPT-violating interaction between CMB photons and an external scalar field. Such kind of interaction could give rise to the rotation of the linear polarization state of CMB photons, and consequently induce the CMB BB power spectrum, which could mimic the signal of primordial gravitational waves at large scales. With the recently released polarization data of BICEP2 and the joint analysis data of BICEP2/Keck Array and Planck, we perform a global fitting analysis on constraining the tensor-to-scalar ratio r by considering the polarization rotation angle [α(nˆ] which can be separated into a background isotropic part [α¯] and a small anisotropic part [Δα(nˆ]. Since the data of BICEP2 and Keck Array experiments have already been corrected by using the “self-calibration” method, here we mainly focus on the effects from the anisotropies of CMB polarization rotation angle. We find that including Δα(nˆ in the analysis could slightly weaken the constraints on the tensor-to-scalar ratio r, when using current CMB polarization measurements. We also simulate the mock CMB data with the BICEP3-like sensitivity. Very interestingly, we find that if the effects of the anisotropic polarization rotation angle could not be taken into account properly in the analysis, the constraints on r will be dramatically biased. This implies that we need to break the degeneracy between the anisotropies of the CMB polarization rotation angle and the CMB primordial tensor perturbations, in order to measure the signal of primordial

  9. Joint measurements of spin, operational locality and uncertainty

    International Nuclear Information System (INIS)

    Andersson, E.; Barnett, S.M.; Aspect, A.

    2005-01-01

    Full text: Joint measurements of non-commuting observables are possible within quantum mechanics, if one accepts an increase in the variances of the jointly measured observables. In this contribution, we discuss joint measurements of spin 1/2 along any two directions. Starting from an operational locality principle, we show how to obtain the known bound on how sharp the joint measurement can be. Operational locality here means, that no operation performed at a quantum system at one location can instantaneously affect a system at another location. The measurement bound is general and is here obtained without reference to any quantum measurement formalism. We find that the bound is formally identical to a Bell inequality of the CHSH type, and we also give a direct interpretation of the measurement bound in terms of an uncertainty relation. A simple way to realise the joint measurement for the case of photon polarization is presented. Further to their fundamental interest, quantum joint measurements of non-commuting observables can be related to state estimation. They are also of interest in quantum information, e.g. as strategies for eavesdropping in quantum cryptography. (author)

  10. Measurement of the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering

    International Nuclear Information System (INIS)

    Stuart, S.J.

    1982-08-01

    The experimental procedures and methods of data analysis used to measure the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering at thirteen different energies in the range 300 to 800 MeV are presented. The results compare favorably with previous data. Good agreement is found with phase shift predictions at energies below 500 MeV

  11. Rotational dynamics in supercooled water from nuclear spin relaxation and molecular simulations.

    Science.gov (United States)

    Qvist, Johan; Mattea, Carlos; Sunde, Erik P; Halle, Bertil

    2012-05-28

    Structural dynamics in liquid water slow down dramatically in the supercooled regime. To shed further light on the origin of this super-Arrhenius temperature dependence, we report high-precision (17)O and (2)H NMR relaxation data for H(2)O and D(2)O, respectively, down to 37 K below the equilibrium freezing point. With the aid of molecular dynamics (MD) simulations, we provide a detailed analysis of the rotational motions probed by the NMR experiments. The NMR-derived rotational correlation time τ(R) is the integral of a time correlation function (TCF) that, after a subpicosecond librational decay, can be described as a sum of two exponentials. Using a coarse-graining algorithm to map the MD trajectory on a continuous-time random walk (CTRW) in angular space, we show that the slowest TCF component can be attributed to large-angle molecular jumps. The mean jump angle is ∼48° at all temperatures and the waiting time distribution is non-exponential, implying dynamical heterogeneity. We have previously used an analogous CTRW model to analyze quasielastic neutron scattering data from supercooled water. Although the translational and rotational waiting times are of similar magnitude, most translational jumps are not synchronized with a rotational jump of the same molecule. The rotational waiting time has a stronger temperature dependence than the translation one, consistent with the strong increase of the experimentally derived product τ(R) D(T) at low temperatures. The present CTRW jump model is related to, but differs in essential ways from the extended jump model proposed by Laage and co-workers. Our analysis traces the super-Arrhenius temperature dependence of τ(R) to the rotational waiting time. We present arguments against interpreting this temperature dependence in terms of mode-coupling theory or in terms of mixture models of water structure.

  12. Radio Polarisation Study of High Rotation Measure AGNs

    Directory of Open Access Journals (Sweden)

    Yik Ki Ma

    2017-10-01

    Full Text Available As radio polarised emission from astrophysical objects traverse through foreground magnetised plasma, the physical conditions along the lines of sight are encrypted in the form of rotation measure (RM. We performed broadband spectro-polarimetric observations of high rotation measure ( | RM | ≳ 300 rad m − 2 sources away from the Galactic plane ( | b | > 10 ∘ selected from the NVSS RM catalogue. The main goals are to verify the NVSS RM values, which could be susceptible to n π -ambiguity, as well as to identify the origin of the extreme RM values. We show that 40 % of our sample suffer from n π -ambiguity in the NVSS RM catalogue. There are also hints of RM variabilities over ∼20 years epoch for most of our sources, as revealed by comparing the RM values of the two studies in the same frequency ranges after correcting for n π -ambiguity. At last, we demonstrate the possibility of applying QU-fitting to study the ambient media of AGNs.

  13. Observation of spin Hall effect in photon tunneling via weak measurements.

    Science.gov (United States)

    Zhou, Xinxing; Ling, Xiaohui; Zhang, Zhiyou; Luo, Hailu; Wen, Shuangchun

    2014-12-09

    Photonic spin Hall effect (SHE) manifesting itself as spin-dependent splitting escapes detection in previous photon tunneling experiments due to the fact that the induced beam centroid shift is restricted to a fraction of wavelength. In this work, we report on the first observation of this tiny effect in photon tunneling via weak measurements based on preselection and postselection technique on the spin states. We find that the spin-dependent splitting is even larger than the potential barrier thickness when spin-polarized photons tunneling through a potential barrier. This photonic SHE is attributed to spin-redirection Berry phase which can be described as a consequence of the spin-orbit coupling. These findings provide new insight into photon tunneling effect and thereby offer the possibility of developing spin-based nanophotonic applications.

  14. Parametrization of optimum filter passbands for rotational Raman temperature measurements.

    Science.gov (United States)

    Hammann, Eva; Behrendt, Andreas

    2015-11-30

    We revisit the methodology of rotational Raman temperature measurements covering both lidar and non-range-resolved measurements, e.g., for aircraft control. The results of detailed optimization calculations are presented for the commonly used extraction of signals from the anti-Stokes branch. Different background conditions and realistic shapes of the filter transmission curves are taken into account. Practical uncertainties of the central passbands and widths are discussed. We found a simple parametrization for the optimum filter passband shifts depending on the atmospheric temperature range of interest and the background. The approximation errors of this parametrization are smaller than 2% for temperatures between 200 and 300 K and smaller than 4% between 180 and 200 K.

  15. Effective suppression of thermoelectric voltage in nonlocal spin-valve measurement

    Science.gov (United States)

    Ariki, Taisei; Nomura, Tatsuya; Ohnishi, Kohei; Kimura, Takashi

    2017-06-01

    We demonstrate that the background signal in the nonlocal spin-valve measurement can be sufficiently suppressed by optimizing the electrode design of the lateral spin valve. A relatively long length scale of heat propagation produces spin-independent thermoelectric signals under the combination of the Peltier and Seebeck effects. These unfavorable signals can be reduced by mixing the Peltier effects in two transparent ferromagnetic/nonmagnetic junctions. Proper understanding of the contribution from the heat current in no spin-current area is a key for effective reduction of the spin-independent background signal.

  16. Spin transport at the international linear collider and its impact on the measurement of polarization

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Moritz

    2013-12-15

    At the planned International Linear Collider (ILC), the longitudinal beam polarization needs to be determined with an unprecedented precision. For that purpose, the beam delivery systems (BDS) are equipped with two laser Compton polarimeters each, which are foreseen to achieve a systematic uncertainty of {<=} 0.25 %. The polarimeters are located 1.6 km upstream and 150 m downstream of the e{sup +}e{sup -} interaction point (IP). The average luminosity-weighted longitudinal polarization P{sup lumi}{sub z}, which is the decisive quantity for the experiments, has to be determined from these measurements with the best possible precision. Therefore, a detailed understanding of the spin transport in the BDS is mandatory to estimate how precise the longitudinal polarization at the IP is known from the polarimeter measurements. The envisaged precision for the propagation of the measurement value is {<=} 0.1 %. This thesis scrutinizes the spin transport in view of the achievable precision. A detailed beamline simulation for the BDS has been developed, including the simulation of the beam-beam collisions at the IP. The following factors which might limit the achievable precision is investigated: a variation of the beam parameters, the beam alignment precision at the polarimeters and the IP, the bunch rotation at the IP, the detector magnets, the beam-beam collisions, the emission of synchrotron radiation and misalignments of the beamline elements. In absence of collisions, a precision of 0.085% on the propagation of the measured longitudinal polarization has been found achievable. This result however depends mainly on the presumed precisions for the parallel alignment of the beam at the polarimeters and for the alignment of polarization vector. In presence of collisions, the measurement at the downstream polarimeter depends strongly on the intensity of the collision and the size of the polarimeter laser spot. Therefore, a more detailed study of the laser-bunch interaction is

  17. Spin dynamics of the LAGEOS satellite in support of a measurement of the Earth's gravitomagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Habib, S. (Theoretical Astrophysics Group (T-6, MS B288), Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Holz, D.E. (Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States) Theoretical Astrophysics Group (T-6, MS B288), Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Kheyfets, A. (Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695-8205 (United States)); Matzner, R.A. (Center for Relativity and Physics Department, The University of Texas at Austin, Austin, Texas 78712-1081 (United States) Applied Research Laboratories, The University of Texas at Austin, P.O. Box 8029, Austin, Texas 78713-8209 (United States)); Miller, W.A. (Theoretical Astrophysics Group (T-6, MS B288), Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) Astrodynamics Bran

    1994-11-15

    LAGEOS is an accurately tracked, dense spherical satellite covered with 426 retroreflectors. Ciufolini has suggested the launch of an additional satellite (LAGEOS-3) into an orbit supplementary to that of the 1976-launched LAGEOS-1. In addition to providing a more accurate real-time measurement of the Earth's length of day and polar wobble, this paired-satellite experiment would provide the first direct measurement of the general relativistic frame-dragging effect. Of the five dominant error sources in this experiment, the largest one involves surface forces on the satellite, and their consequent impact on the orbital nodal precession. The surface forces are a function of the spin dynamics of the satellite. Consequently, we undertake here a theoretical effort to model the spin dynamics of LAGEOS. In this paper we derive, and solve numerically, a set of Euler equations that evolve the angular momentum vector for a slightly oblate spheroid of brass orbiting an Earth-like mass, idealized as being a perfect sphere and having a perfect polar-oriented dipole magnetic field. We have identified three phases of the rotational dynamics---a fast spin phase, a spin-orbit resonance phase, and an asymptotic (tidally locked) phase. From our numerical runs we give analytic expressions for this tidally locked phase.

  18. A compiled catalog of rotation measures of radio point sources

    International Nuclear Information System (INIS)

    Xu Jun; Han Jin-Lin

    2014-01-01

    We compiled a catalog of Faraday rotation measures (RMs) for 4553 extragalactic radio point sources published in literature. These RMs were derived from multi-frequency polarization observations. The RM data are compared to those in the NRAO VLA Sky Survey (NVSS) RM catalog. We reveal a systematic uncertainty of about 10.0 ± 1.5 rad m −2 in the NVSS RM catalog. The Galactic foreground RM is calculated through a weighted averaging method by using the compiled RM catalog together with the NVSS RM catalog, with careful consideration of uncertainties in the RM data. The data from the catalog and the interface for the Galactic foreground RM calculations are publicly available on the webpage: http://zmtt.bao.ac.cn/RM/. (research papers)

  19. Rotational high spin structures in doubly-odd in {sup 184}Au

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, F.; Roussiere, B.; Sauvage, J.; Bourgeois, C.; Korichi, A. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Hojman, D.; Kreiner, A.J.; Davidson, J.; Davidson, M.; Debray, M. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Dept. de Fisica; Knipper, A. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Marguier, G. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire] [and others

    1995-12-31

    Excited states in the doubly-odd {sup 184}Au nucleus have been studied by in-beam {gamma}-ray spectroscopy. This nucleus was produced through the fusion-evaporation reactions {sup 165}Ho({sup 24}Mg, 5n), {sup 170}Yb({sup 19}F, 5n) and {sup 161}Dy({sup 27}Al, 4n). Different rotational band structures have been observed and interpreted as specific couplings of proton and neutron single-particle excitations present in neighboring odd Au and Pt nuclei. (author). 34 refs.; Submitted to Physical Review, C (US).

  20. Measuring Pancharatnam's relative phase for SO(3) evolutions using spin polarimetry

    International Nuclear Information System (INIS)

    Larsson, Peter; Sjoeqvist, Erik

    2003-01-01

    In polarimetry, a superposition of internal quantal states is exposed to a single Hamiltonian and information about the evolution of the quantal states is inferred from projection measurements on the final superposition. In this framework, we here extend the polarimetric test of Pancharatnam's relative phase for spin-(1/2) proposed by Wagh and Rakhecha [Phys. Lett. A 197, 112 (1995)] to spin j≥1 undergoing noncyclic SO(3) evolution. We demonstrate that the output intensity for higher spin values is a polynomial function of the corresponding spin-(1/2) intensity. We further propose a general method to extract the noncyclic SO(3) phase and visibility by rigid translation of two π/2 spin flippers. Polarimetry on higher spin states may in practice be done with spin polarized atomic beams

  1. Spiral spin state in high-temperature copper-oxide superconductors: evidence from neutron scattering measurements.

    Science.gov (United States)

    Lindgård, Per-Anker

    2005-11-18

    An effective spiral spin phase ground state provides a new paradigm for the high-temperature superconducting cuprates. It accounts for the recent neutron scattering observations of spin excitations regarding both the energy dispersion and the intensities, including the "universal" rotation by 45 degrees around the resonance energy . The intensity has a 2D character even in a single twin crystal. The value of is related to the nesting properties of the Fermi surface. The excitations above are shown to be due to in-plane spin fluctuations, a testable difference from the stripe model. The form of the exchange interaction function reveals the effects of the Fermi surface, and the unique shape predicts large quantum spin fluctuations in the ground state.

  2. New measurements of transverse spin asymmetries at COMPASS

    CERN Document Server

    Sozzi, F

    2012-01-01

    The study of transverse momentum effects and transverse spin structure of the nucleon is an important part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. The transverse effects are investigated via semi inclusive DIS reactions with a 160 GeV /c muon beam impinging on transversely polarised targets. The hadrons produced in the reactions are detected in a wide momentum and angular range by a two-stage spectrometer. A deuterium target has been used in the first part of COMPASS data taking from 2002 to 2004, while a proton target has been used in 2007 and 2010. Here we present the recent results obtained from the 2010 data on different channels, involving the azimuthal distribution of single hadrons and the azimuthal dependence of the plane cont aining hadron pairs. The results confirm the published results of the 2007 data taking with an improved statistical significance; the measured azimuthal asymmetries are clearly non zero, at variance with those measured on a deuterium targ...

  3. Femoral rotation unpredictably affects radiographic anatomical lateral distal femoral angle measurements

    DEFF Research Database (Denmark)

    Miles, James Edward

    2016-01-01

    Objective: To describe the effects of internal and external femoral rotation on radiographic measurements of the anatomical lateral distal femoral angle (a-LDFA) using two methods for defining the anatomical proximal femoral axis (a-PFA). Methods: Digital radiographs were obtained of 14 right...... femora at five degree intervals from 10° external rotation to 10° internal rotation. Using freely available software, a-LDFA measurements were made using two different a-PFA by a single observer on one occasion. Results: Mean a-LDFA was significantly greater at 10° external rotation than at any other...... rotation. The response of individual femora to rotation was unpredictable, although fairly stable within ±5° of zero rotation. Mean a-LDFA for the two a-PFA methods differed by 1.5°, but were otherwise similarly affected by femoral rotation. Clinical significance: If zero femoral elevation can be achieved...

  4. Spin correlation and entanglement detection in Cooper pair splitters by current measurements using magnetic detectors

    Science.gov (United States)

    Busz, Piotr; Tomaszewski, Damian; Martinek, Jan

    2017-08-01

    We analyze a model of a double quantum dot Cooper pair splitter coupled to two ferromagnetic detectors and demonstrate the possibility of determination of spin correlation by current measurements. We use perturbation theory, taking account of the exchange interaction with the detectors, which leads to complex spin dynamics in the dots. This affects the measured spin and restricts the use of ferromagnetic detectors to the nonlinear current-voltage characteristic regime at the current plateau, where the relevant spin projection is conserved, in contrast to the linear current-voltage characteristic regime, in which the spin information is distorted. Moreover, we show that for separable states the spin correlation can only be determined in a limited parameter regime, much more restricted than in the case of entangled states. We propose an entanglement test based on the Bell inequality.

  5. Doppler limited rotational transitions of OH and SH radicals measured by continuous-wave terahertz photomixing

    Science.gov (United States)

    Eliet, Sophie; Martin-Drumel, Marie-Aline; Guinet, Mickaël; Hindle, Francis; Mouret, Gaël; Bocquet, Robin; Cuisset, Arnaud

    2011-12-01

    A continuous-wave terahertz (CW-THz) source generated by photomixing has been employed to detect and quantify radicals produced in a cold plasma probing their spin-rotation transitions. Due to their dual interest for both atmospherists and astrophysicists, the hydroxyl OH and the mercapto SH radicals have been chosen. The photomixing technique which can access the largest range of THz frequencies of any known coherent source, allowed to resolve the Doppler-limited hyperfine transitions of OH in the 2.5 THz frequency region. Line profile analysis of the hyperfine components demonstrated that OH radicals have been detected in this region at a ppm level at a temperature close to 490 K. The hyperfine structure of SH has been resolved for the first time above 1 THz. Ten new frequency transitions have been measured in the 1.3-2.6 THz frequency range using the CW-THz synthesizer based on a frequency comb. With relative uncertainties better than 10 -7, the CW-THz frequencies measured in this study are now competitive with those measured by other instruments such as frequency multiplication chains or FT-FIR spectrometers and are now capable to improve the predictions of the complete high-resolution spectra of these radicals collected in the atmospheric and astrophysical spectroscopic databases. versioncorrigeeAC 2011-07-18 17:32 2011 Arnaud Cuisset.

  6. Beam Spin Asymmetry Measurements for Two Pion Photoproduction at CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark D. [Univ. of Glasgow, Scotland (United Kingdom)

    2015-09-01

    The overarching goal of this analysis, and many like it, is to develop our understanding of the strong force interactions within the nucleon by examining the nature of their excitation spectra. As the resonances of these spectra have very short lifetimes (tau = 1x10-23 s) and often have very similar masses, it is often impossible to directly observe resonances in the excitation spectra of nucleons. Polarization observables allow us to study the resonances by looking at how they affect the spin state of final state particles. The beam asymmetry is a polarization observable that allows us to detect the sensitivity of these resonances, and other transition mechanisms, to the electric vector orientation of incident photons. Presented in this thesis are first measurements of the beam asymmetries in the resonant region for the reaction channel pgamma p --> p π+ π-focusing on the intermediate mesonic states rho^0 and f^0, and the final state pions. The analysis used data from the g8b experiment undertaken at the Thomas Jefferson National Accelerator Facility (JLab), the first experiment at JLab to use a linearly polarized photon beam. Using the coherent Bremsstrahlung facility and the CLAS detector of Hall B at JLab allowed for many multi-channel reactions to be detected and the first measurements of many polarization observables including those presented here. A brief overview of the theoretical framework used to undertake this analysis is given, followed by a description of the experimental details of the facilities used, then a description of the calibration of the Bremsstrahlung tagging facility which the author undertook, and finally the analysis is presented and the resulting measurements.

  7. Measurement of np elastic scattering spin-spin correlation parameters at 484, 634, and 788 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Garnett, R.W.

    1989-03-01

    The spin-spin correlation parameters C/sub LL/ and C/sub SL/ were measured for np elastic scattering at the incident neutron kinetic energy of 634 MeV. Good agreement was obtained with previously measured data. Additionally, the first measurement of the correlation parameter C/sub SS/ was made at the three energies, 484, 634, and 788 MeV. It was found that the new values, in general, do not agree well with phase shift predictions. A study was carried out to determine which of the isospin-0 partial waves will be affected by this new data. It was found that the /sup 1/P/sub 1/ partial wave will be affected significantly at all three measurement energies. At 634 and 788 MeV, the /sup 3/S/sub 1/ phase shifts will also change. 29 refs., 21 figs., 16 tabs.

  8. Measurement of np elastic scattering spin-spin correlation parameters at 484, 634, and 788 MeV

    International Nuclear Information System (INIS)

    Garnett, R.W.

    1989-03-01

    The spin-spin correlation parameters C/sub LL/ and C/sub SL/ were measured for np elastic scattering at the incident neutron kinetic energy of 634 MeV. Good agreement was obtained with previously measured data. Additionally, the first measurement of the correlation parameter C/sub SS/ was made at the three energies, 484, 634, and 788 MeV. It was found that the new values, in general, do not agree well with phase shift predictions. A study was carried out to determine which of the isospin-0 partial waves will be affected by this new data. It was found that the 1 P 1 partial wave will be affected significantly at all three measurement energies. At 634 and 788 MeV, the 3 S 1 phase shifts will also change. 29 refs., 21 figs., 16 tabs

  9. First measurement of poloidal-field-induced Faraday rotation in a tokamak plasma

    International Nuclear Information System (INIS)

    Kunz, W.; Association Euratom-CEA sur la Fusion, Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92

    1978-01-01

    Faraday rotation measurements using a ferrite modulation technique were performed on one channel of the 337 μm-interferometer on TFR. The experiment is intended as a preparatory step towards poloidal-field determination on the basis of the Faraday effect in a multi-channel configuration. The technical feasibility of precise Faraday rotation measurements under machine conditions is demonstrated. The measured rotation is unambiguously due to the poloidal magnetic field and agrees fairly with what can be estimated. (author)

  10. Spin structure measurements from E143 at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, L.M. [Stanford Univ., CA (United States)

    1997-01-01

    Measurements have been made of the proton and deuteron spin structure functions, g{sub 1}{sup p} at beam energies of 29.1, 16.2, and 9.7 GeV, and g{sub 2}{sup p} and g{sub 2}{sup d} at a beam energy of 29.1 GeV. The integrals {Gamma}{sub p} = {integral}{sub 0}{sup 1} g{sub 1}{sup p} (x, Q{sup 2})dx and {Gamma}{sub d} = {integral}{sub 0}{sup 1} g{sub 1}{sup d}(x, Q{sup 2})dx have been evaluated at fixed Q{sup 2} = 3 (GeV/c){sup 2} using the 29.1 GeV data to yield {Gamma}{sub p} = 0.127 {+-} 0.004(stat.) {+-} 0.010(syst.) and {Gamma}{sub d} = 0.041 {+-} 0.003 {+-} 0.004. The Q{sup 2} dependence of the ratio g{sub 1}/F{sub 1} has been studied and is found to be small for Q{sup 2} > 1 (GeV/c){sup 2}. Within experimental precision, the g{sub 2} data are well-described by the twist-2 contribution, g{sub 2}{sup ww}. Twist-3 matrix elements have been extracted and are compared to theoretical predictions. The asymmetry A{sub 2} has also been measured and is found to be significantly smaller than the positivity limit {radical}R for both targets A{sub 2}{sup p} is found to be positive and inconsistent with zero.

  11. A novel method of measuring spatial rotation angle using MEMS tilt sensors

    International Nuclear Information System (INIS)

    Cao, Jian’an; Zhu, Xin; Zhang, Leping; Wu, Hao

    2017-01-01

    This paper presents a novel method of measuring spatial rotation angle with a dual-axis micro-electro-mechanical systems tilt sensor. When the sensor is randomly mounted on the surface of the rotating object, there are three unpredictable and unknown mounting position parameters: α , the sensor’s swing angle on the measuring plane; β , the angle between the rotation axis and the horizontal plane; and γ , the angle between the measuring plane and the rotation axis. Thus, the sensor’s spatial rotation model is established to describe the relationship between the measuring axis, rotation axis, and horizontal plane, and the corresponding analytical equations are derived. Furthermore, to eliminate the deviation caused by the uncertain direction of the rotation axis, an extra perpendicularly mounted, single-axis tilt sensor is combined with the dual-axis tilt sensor, forming a three-axis tilt sensor. Then, by measuring the sensors’ three tilts and solving the model’s equations, the object’s spatial rotation angle is obtained. Finally, experimental results show that the developed tilt sensor is capable of measuring spatial rotation angle in the range of  ±180° with an accuracy of 0.2° if the angle between the rotation axis and the horizontal plane is less than 75°. (paper)

  12. Measuring the spin of black holes in binary systems using gravitational waves.

    Science.gov (United States)

    Vitale, Salvatore; Lynch, Ryan; Veitch, John; Raymond, Vivien; Sturani, Riccardo

    2014-06-27

    Compact binary coalescences are the most promising sources of gravitational waves (GWs) for ground-based detectors. Binary systems containing one or two spinning black holes are particularly interesting due to spin-orbit (and eventual spin-spin) interactions and the opportunity of measuring spins directly through GW observations. In this Letter, we analyze simulated signals emitted by spinning binaries with several values of masses, spins, orientations, and signal-to-noise ratios, as detected by an advanced LIGO-Virgo network. We find that for moderate or high signal-to-noise ratio the spin magnitudes can be estimated with errors of a few percent (5%-30%) for neutron star-black hole (black hole-black hole) systems. Spins' tilt angle can be estimated with errors of 0.04 rad in the best cases, but typical values will be above 0.1 rad. Errors will be larger for signals barely above the threshold for detection. The difference in the azimuth angles of the spins, which may be used to check if spins are locked into resonant configurations, cannot be constrained. We observe that the best performances are obtained when the line of sight is perpendicular to the system's total angular momentum and that a sudden change of behavior occurs when a system is observed from angles such that the plane of the orbit can be seen both from above and below during the time the signal is in band. This study suggests that direct measurement of black hole spin by means of GWs can be as precise as what can be obtained from x-ray binaries.

  13. The measurable distinction between the spin and orbital angular momenta of electromagnetic radiation

    Directory of Open Access Journals (Sweden)

    James H. Crichton

    2000-07-01

    Full Text Available We show how the angular momentum of electromagnetic radiation may be decomposed into spin and orbital parts, of which the spin part is measurable in terms of Stokes parameters, thereby providing an unambiguous, gauge-invariant, distinction between the two parts.

  14. Sum rule measurements of the spin-dependent compton amplitude (nucleon spin structure at Q2 = 0)

    International Nuclear Information System (INIS)

    Babusci, D.; Giordano, G.; Baghaei, H.; Cichocki, A.; Blecher, M.; Breuer, M.; Commeaux, C.; Didelez, J.P.; Caracappa, A.; Fan, Q.

    1995-01-01

    Energy weighted integrals of the difference in helicity-dependent photo-production cross sections (σ 1/2 - σ 3/2 ) provide information on the nucleon's Spin-dependent Polarizability (γ), and on the spin-dependent part of the asymptotic forward Compton amplitude through the Drell-Hearn-Gerasimov (DHG) sum rule. (The latter forms the Q 2 =0 limit of recent spin-asymmetry experiments in deep-inelastic lepton-scattering.) There are no direct measurements of σ 1/2 or σ 3/2 , for either the proton or the neutron. Estimates from current π-photo-production multipole analyses, particularly for the proton-neutron difference, are in good agreement with relativistic-l-loop Chiral calculations (χPT) for γ but predict large deviations from the DHG sum rule. Either (a) both the 2-loop corrections to the Spin-Polarizability are large and the existing multipoles are wrong, or (b) modifications to the Drell-Hearn-Gerasimov sum rule are required to fully describe the isospin structure of the nucleon. The helicity-dependent photo-reaction amplitudes, for both the proton and the neutron, will be measured at LEGS from pion-threshold to 470 MeV. In these double-polarization experiments, circularly polarized photons from LEGS will be used with SPHICE, a new frozen-spin target consisting of rvec H · rvec D in the solid phase. Reaction channels will be identified in SASY, a large detector array covering about 80% of 4π. A high degree of symmetry in both target and detector will be used to minimize systematic uncertainties

  15. Probing Nuclear Spin Effects on Electronic Spin Coherence via EPR Measurements of Vanadium(IV) Complexes.

    Science.gov (United States)

    Graham, Michael J; Krzyaniak, Matthew D; Wasielewski, Michael R; Freedman, Danna E

    2017-07-17

    Quantum information processing (QIP) has the potential to transform numerous fields from cryptography, to finance, to the simulation of quantum systems. A promising implementation of QIP employs unpaired electronic spins as qubits, the fundamental units of information. Though molecular electronic spins offer many advantages, including chemical tunability and facile addressability, the development of design principles for the synthesis of complexes that exhibit long qubit superposition lifetimes (also known as coherence times, or T 2 ) remains a challenge. As nuclear spins in the local qubit environment are a primary cause of shortened superposition lifetimes, we recently conducted a study which employed a modular spin-free ligand scaffold to place a spin-laden propyl moiety at a series of fixed distances from an S = 1 / 2 vanadium(IV) ion in a series of vanadyl complexes. We found that, within a radius of 4.0(4)-6.6(6) Å from the metal center, nuclei did not contribute to decoherence. To assess the generality of this important design principle and test its efficacy in a different coordination geometry, we synthesized and investigated three vanadium tris(dithiolene) complexes with the same ligand set employed in our previous study: K 2 [V(C 5 H 6 S 4 ) 3 ] (1), K 2 [V(C 7 H 6 S 6 ) 3 ] (2), and K 2 [V(C 9 H 6 S 8 ) 3 ] (3). We specifically interrogated solutions of these complexes in DMF-d 7 /toluene-d 8 with pulsed electron paramagnetic resonance spectroscopy and electron nuclear double resonance spectroscopy and found that the distance dependence present in the previously synthesized vanadyl complexes holds true in this series. We further examined the coherence properties of the series in a different solvent, MeCN-d 3 /toluene-d 8 , and found that an additional property, the charge density of the complex, also affects decoherence across the series. These results highlight a previously unknown design principle for augmenting T 2 and open new pathways for the

  16. Measuring Quasar Spin via X-ray Continuum Fitting

    Science.gov (United States)

    Jenkins, Matthew; Pooley, David; Rappaport, Saul; Steiner, Jack

    2018-01-01

    We have identified several quasars whose X-ray spectra appear very soft. When fit with power-law models, the best-fit indices are greater than 3. This is very suggestive of thermal disk emission, indicating that the X-ray spectrum is dominated by the disk component. Galactic black hole binaries in such states have been successfully fit with disk-blackbody models to constrain the inner radius, which also constrains the spin of the black hole. We have fit those models to XMM-Newton spectra of several of our identified soft X-ray quasars to place constraints on the spins of the supermassive black holes.

  17. Measurement of spin observables using a storage ring with polarized beam and polarized internal gas target

    International Nuclear Information System (INIS)

    Lee, K.; Miller, M.A.; Smith, A.; Hansen, J.; Bloch, C.; van den Brand, J.F.J.; Bulten, H.J.; Ent, R.; Goodman, C.D.; Jacobs, W.W.; Jones, C.E.; Korsch, W.; Leuschner, M.; Lorenzon, W.; Marchlenski, D.; Meyer, H.O.; Milner, R.G.; Neal, J.S.; Pancella, P.V.; Pate, S.F.; Pitts, W.K.; von Przewoski, B.; Rinckel, T.; Sowinski, J.; Sperisen, F.; Sugarbaker, E.; Tschalaer, C.; Unal, O.; Zhou, Z.

    1993-01-01

    We report the first measurement of analyzing powers and spin correlation parameters using a storage ring with both beam and internal target polarized. Spin observables were measured for elastic scattering of 45 and 198 MeV protons from polarized 3 He nuclei in a new laser-pumped internal gas target at the Indiana University Cyclotron Facility Cooler Ring. Scattered protons and recoil 3 He nuclei were detected in coincidence with large acceptance plastic scintillators and silicon detectors. The internal-target technique demonstrated in this experiment has broad applicability to the measurement of spin-dependent scattering in nuclear and particle physics

  18. Method of rotation angle measurement in machine vision based on calibration pattern with spot array

    International Nuclear Information System (INIS)

    Li Weimin; Jin Jing; Li Xiaofeng; Li Bin

    2010-01-01

    We propose a method of rotation angle measurement with high precision in machine vision. An area scan CCD camera, imaging lens, and calibration pattern with a spot array make up the measurement device for measuring the rotation angle. The calibration pattern with a spot array is installed at the rotation part, and the CCD camera is set at a certain distance from the rotation components. The coordinates of the spots on the calibration pattern is acquired through the vision image of the calibration pattern captured by the CCD camera. At the initial position of the calibration pattern, the camera is calibrated with the spot array; the mathematical model of distortion error of the CCD camera is built. With the equation of coordinate rotation measurement, the rotation angle of the spot array is detected. In the theoretic simulation, noise of different levels is added to the coordinates of the spot array. The experiment results show that the measurement device can measure the rotation angle precisely with a noncontact method. The standard deviation of rotation angle measurement is smaller than 3 arc sec. The measurement device can measure both microangles and large angles.

  19. Plasma Density Measurements on Refuelling by Solid Hydrogen Pellets in a Rotating Plasma

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, A. H.

    1978-01-01

    The authors used laser interferometry to directly measure the increase in plasma density caused by the ablation of a solid hydrogen pellet situated in a rotating plasma.......The authors used laser interferometry to directly measure the increase in plasma density caused by the ablation of a solid hydrogen pellet situated in a rotating plasma....

  20. Measurement of rotating flows using PIV and image derotation

    Energy Technology Data Exchange (ETDEWEB)

    Stickland, M.T.; Scanlon, T.J.; Waddell, P. [University of Strathclyde, Department of Mechanical Engineering, Glasgow, G1 1XJ (United Kingdom); Fernandez-Francos, J.; Blanco, E. [University of Oviedo, Fluid Mechanics Group, Asturias (Spain)

    2003-02-01

    This paper describes the use of a rotating all-mirror image derotator system, high-speed video and particle image velocimetry (PIV) to visualise and quantitatively examine the flow patterns between the blades of a centrifugal impeller. The flow field relative to the moving centrifugal impeller is presented. (orig.)

  1. Measurement of rotating flows using PIV and image derotation

    Science.gov (United States)

    Stickland, M. J.; Scanlon, T. J.; Waddell, P.; Fernandez-Francos, J.; Blanco, E.

    2003-02-01

    This paper describes the use of a rotating all-mirror image derotator system, high-speed video and particle image velocimetry (PIV) to visualise and quantitatively examine the flow patterns between the blades of a centrifugal impeller. The flow field relative to the moving centrifugal impeller is presented.

  2. New portable sensor system for rotation seismic motion measurements

    Czech Academy of Sciences Publication Activity Database

    Brokešová, J.; Málek, Jiří

    2010-01-01

    Roč. 81, č. 8 (2010), 084501 ISSN 0034-6748 R&D Projects: GA ČR GAP210/10/0925 Institutional research plan: CEZ:AV0Z30460519 Keywords : rotation al seismology * sensor system Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.598, year: 2010

  3. A possible scheme for measuring gravitational waves by using a spinful quantum fluid

    Directory of Open Access Journals (Sweden)

    Cheng Yao

    2014-06-01

    Full Text Available A method is proposed for measuring gravitational waves (GWs from the collective electromagnetic (EM response of a spinful quantum fluid, based on recent studies of the long-lived Mössbauer state 93mNb in a pure Nb crystal. A pronounced EM response was found for the geometric phase by rotating the sample in a magnetic field, suggesting that GWs could also be detected. It was recently suggested that the macroscopic wave functions confined in two twisted nonspherical superconductors would give a geometrical phase oscillation induced by GWs. The sensitivity to GWs would be inversely proportional to the square of the bound length, which is the detector size. The proposed sensitivity to GWs would be dramatically enhanced by changing the characteristic size, i.e., using the microscopic size of a non-spherical particle instead of the macroscopic detector size of a scalar quantum fluid. The collective EM response from the quantum fluid would allow the macroscopic geometrical phase to be read from microscopic particles. GWs in the millihertz range, with amplitude of 10−22, would be detectable.

  4. Measuring the spin Chern number in time-reversal-invariant Hofstadter optical lattices

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dan-Wei, E-mail: zdanwei@126.com [Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, SPTE, South China Normal University, Guangzhou 510006 (China); Cao, Shuai, E-mail: shuaicao2004@163.com [Department of Applied Physics, College of Electronic Engineering, South China Agricultural University, Guangzhou 510642 China (China)

    2016-10-14

    We propose an experimental scheme to directly measure the spin Chern number of the time-reversal-invariant Hofstadter model in optical lattices. We first show that this model can be realized by using ultracold Fermi atoms with two pseudo-spin states encoded by the internal Zeeman states in a square optical lattice and the corresponding topological Bloch bands are characterized by the spin Chern number. We then propose and numerically demonstrate that this topological invariant can be extracted from the shift of the hybrid Wannier center in the optical lattice. By spin-resolved in situ detection of the atomic densities along the transverse direction combined with time-of-flight measurement along another spatial direction, the spin Chern number in this system is directly measured. - Highlights: • The cold-atom optical-lattice scheme for realizing the time-reversal-invariant Hofstadter model is proposed. • The intrinsic spin Chern number related to the hybrid Wannier center in the optical lattice is investigated. • Direct measurement of the spin Chern number in the proposed system is theoretically demonstrated.

  5. Measuring spin-dependent structure functions at CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A. [Universitaet Frankfurt (Germany)

    1994-04-01

    The author analyses whether CEBAF with a 10 GeV beam could contribute significantly to the understanding of spin-dependent deep-inelastic scattering as well as semi-inclusive reactions. The main advantage of CEBAF is the much better attainable statistics, its great disadvantage its comparably low energy, which limits the accessible x-range to about 0.15 to 0.7. Within these constraints CEBAF could provide (1) high precision data which would be very valuable to understand the Q{sup 2} dependence of the spin-dependent structure functions g{sub 1}(x) and G{sub 2}(x) and (2) the by far most precise determination of the third moments of g{sub 1}(x) and g{sub 2}(x) the latter of which the author argues to be related to a fundamental property of the nucleon.

  6. Rate of rotation measurement using back-EMFS associated with windings of a brushless DC motor

    Science.gov (United States)

    Howard, David E. (Inventor)

    2000-01-01

    A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is integrated and multiplied by the back-emf associated with an adjacent winding. The multiplied outputs associated with each winding are combined to produce a directionally sensitive DC output proportional only to the rate of rotation of the motor's shaft.

  7. A Novel Rotation Speed Measurement Method Based on Surface Acoustic Wave

    Science.gov (United States)

    Fan, Yanping; Ji, Xiaojun

    2018-01-01

    This paper presents an original passive wireless rotation speed measurement method based on surface acoustic wave (SAW) technology. A theoretical analysis was conducted on the principle of SAW rotation speed measurement and a numerical analysis on the SAW response energy pulses with different rotation angles and resonance frequencies was performed. Numerical calculation results showed that when the distance and the effective length of the antenna connected to SAWR vary with the rotation angle, the energy of acquired SAW response varies periodically. The rotation speed was estimated by searching the crossing points of the SAW response energy pulses and its mean value line. The SAW rotation speed measurement system was set up and the high performance SAW resonators were fabricated on a quartz substrate. The proposed measurement system was tested with a maximum error of 0.6 rpm, indicating that the system is capable of measuring rotation speeds from 10 to 100 rpm. Experimental results verified the validity and feasibility of presented rotation speed measurement method.

  8. Application of Roll-Isolated Inertial Measurement Units to the Instrumentation of Spinning Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    BEADER,MARK E.

    2000-12-01

    Roll-isolated inertial measurement units are developed at Sandia for use in the instrumentation, guidance, and control of rapidly spinning vehicles. Roll-isolation is accomplished by supporting the inertial instrument cluster (gyros and accelerometers) on a single gimbal, the axis of which is parallel to the vehicle's spin axis. A rotary motor on the gimbal is driven by a servo loop to null the roll gyro output, thus inertially stabilizing the gimbal and instrument cluster while the vehicle spins around it. Roll-isolation prevents saturation of the roll gyro by the high vehicle spin rate, and vastly reduces measurement errors arising from gyro scale factor and alignment uncertainties. Nine versions of Sandia-developed roll-isolated inertial measurement units have been flown on a total of 27 flight tests since 1972.

  9. Reliability of the spin-T cervical goniometer in measuring cervical range of motion in an asymptomatic Indian population.

    Science.gov (United States)

    Agarwal, Shabnam; Allison, Garry T; Singer, Kevin P

    2005-09-01

    To examine the intratester reliability of the Spin-T goniometer, a cervical range of motion device, in a normal Indian population. Subjects comprised 30 healthy adults with mean age of 34 years (range, 18-65 years). The subjects were stabilized in the sitting position and the Spin-T goniometer mounted on the head of the subject. The study design was a within-subject repeated intratester reliability trial conducted for cervical range of motion in 6 directions of movement. Three measurements were taken in each direction (flexion, extension lateral flexion, and lateral rotation) per participant. Reliability coefficients, intraclass correlation coefficients, and 95% confidence interval were derived from repeated-measures analysis of variance (ANOVA). Where differences in ANOVA were detected, a paired t test was conducted and the typical error values and coefficient of variance were calculated. All repeated measures showed high intraclass correlation coefficients (all >0.96, P goniometer proved to be a reliable measuring instrument for cervical range of movement in an Indian population. The use of a laser pointer fixed to the instrument ensured a consistent neutral start position.

  10. Muon spin rotation study of magnetism and superconductivity in Ba(Fe1-xCox)2As2 single crystals

    DEFF Research Database (Denmark)

    Bernhard, C.; Wang, C. N.; Nuccio, L.

    2012-01-01

    Using muon spin rotation (μSR) we investigated the magnetic and superconducting properties of a series of Ba(Fe1−xCox)2As2 single crystals with 0 ≤x ≤0.15. Our study details how the antiferromagnetic order is suppressed upon Co substitution and how it coexists with superconductivity. In the nonsu......Using muon spin rotation (μSR) we investigated the magnetic and superconducting properties of a series of Ba(Fe1−xCox)2As2 single crystals with 0 ≤x ≤0.15. Our study details how the antiferromagnetic order is suppressed upon Co substitution and how it coexists with superconductivity...... caused by the randomly distributed Co atoms. A different kind of magnetic order that was also previously identified [C. Bernhard et al., New J. Phys. 11, 055050 (2009)] occurs at 0.055 magnetic order develops here only in parts of the sample volume...... and it seems to cooperate with superconductivity since its onset temperature coincides with Tc. Even in the strongly overdoped regime at x = 0.11, where the static magnetic order has disappeared, we find that the low-energy spin fluctuations are anomalously enhanced below Tc. These findings point toward...

  11. Measurements of translation, rotation and strain: new approaches to seismic processing and inversion

    NARCIS (Netherlands)

    Bernauer, M.; Fichtner, A.; Igel, H.

    2012-01-01

    We propose a novel approach to seismic tomography based on the joint processing of translation, strain and rotation measurements. Our concept is based on the apparent S and P velocities, defined as the ratios of displacement velocity and rotation amplitude, and displacement velocity and

  12. Measurements of lifetimes and feeding times for high spin states in 156Dy

    International Nuclear Information System (INIS)

    Ward, D.; Andrews, H.R.; Haeusser, O.; El Masri, Y.; Aleonard, M.M.; Yang-Lee, I.; Diamond, R.; Stephens, F.S.; Butler, P.A.

    1979-01-01

    The inverse reaction 24 Mg( 136 Xe, 4n) 156 Dy at 595 MeV has been used to populate high spin states in 156 Dy. A recoil distance technique was applied to measure lifetimes and feeding times in both the ground state band, and a band of anomalously high moment of intertia. Values for the intrinsic quadrupole moments, Q 0 , were derived to spin 22 + . The limit of centrifugal stretching appeared to be reached at spin 14 + . The results are discussed in terms of band mixing. (orig.)

  13. Orbital rotation without orbital angular momentum: mechanical action of the spin part of the internal energy flow in light beams

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Bekshaev, A. Ya; Maksimyak, P. P.

    2012-01-01

    The internal energy flow in a light beam can be divided into the "orbital" and "spin" parts, associated with the spatial and polarization degrees of freedom of light. In contrast to the orbital one, experimental observation of the spin flow seems problematic because it is converted into an orbital...

  14. In situ measurement of grain rotation during deformation of polycrystals

    DEFF Research Database (Denmark)

    Margulies, L.; Winther, G.; Poulsen, H.F.

    2001-01-01

    Texture evolution governs many of the physical, chemical, and mechanical properties of polycrystalline materials, but texture models have only been tested on the macroscopic Level, which makes it hard to distinguish between approaches that are conceptually very different. Here, we present...... a universal method for providing data on the underlying structural dynamics at the grain and subgrain Level. The method is based on diffraction with focused hard x-rays, First results relate to the tensile deformation of pure aluminum. Experimental grain rotations are inconsistent with the classical Taylor...

  15. Temperature and concentration dependent spin noise measurements in GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, Michael; Mueller, Georg; Huebner, Jens; Oestreich, Michael [Institute for Solid State Physics, Gottfried Wilhelm Leibniz University Hannover (Germany)

    2009-07-01

    Spin noise spectroscopy is an elegant method to access electron properties of direct gap semiconductors in thermal equilibrium while avoiding carrier heating and excitation of electron hole pairs. This technique is used to examine the electron spin lifetime and noise power in GaAs in dependence of electron doping concentration, sample temperature, and the probe laser wavelength. The measured power of the spin noise signal is used to extract information about the electron statistics and the position of the electrons in the conduction band. The measured data can be well explained using a model based on the change of the index of refraction due to the ever present thermal fluctuations of the electron spin.

  16. Measurement of spin observables in exclusive $pp \\to \\Lambda \\Lambda$ production

    CERN Document Server

    Paschke, K

    2000-01-01

    The PS185 experiment at LEAR has produced a wealth of high precision measurements of cross-sections and final state polarization observables in near-threshold antihyperon-hyperon production from antiproton-proton annihilation. In its most recent run, PS185/3 extended its capabilities by utilizing a transversely polarized frozen spin target to measure exclusive Lambda Lambda production. This allows access to a broad set of spin observables involving initial state spin. Competing theoretical models for this reaction have differing predictions for some of these newly accessible spin observables, most notably the depolarization D/sub nn/. This data is expected to provide a rigorous test of these models. Current results from the analysis of this data are presented. (5 refs).

  17. Antiferromagnetic spin Seebeck effect.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Stephen M.; Zhang, Wei; KC, Amit; Borisov, Pavel; Pearson, John E.; Jiang, J. Samuel; Lederman, David; Hoffmann, Axel; Bhattacharya, Anand

    2016-03-03

    We report on the observation of the spin Seebeck effect in antiferromagnetic MnF2. A device scale on-chip heater is deposited on a bilayer of MnF2 (110) (30nm)/Pt (4 nm) grown by molecular beam epitaxy on a MgF2(110) substrate. Using Pt as a spin detector layer, it is possible to measure the thermally generated spin current from MnF2 through the inverse spin Hall effect. The low temperature (2–80 K) and high magnetic field (up to 140 kOe) regime is explored. A clear spin-flop transition corresponding to the sudden rotation of antiferromagnetic spins out of the easy axis is observed in the spin Seebeck signal when large magnetic fields (>9T) are applied parallel to the easy axis of the MnF2 thin film. When the magnetic field is applied perpendicular to the easy axis, the spin-flop transition is absent, as expected.

  18. Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

    Science.gov (United States)

    Budinski, Vedran; Donlagic, Denis

    2017-01-01

    Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation. PMID:28241510

  19. Low-temperature muon spin rotation studies of the monopole charges and currents in Y doped Ho2Ti2O7.

    Science.gov (United States)

    Chang, L J; Lees, M R; Balakrishnan, G; Kao, Y-J; Hillier, A D

    2013-01-01

    In the ground state of Ho2Ti2O7 spin ice, the disorder of the magnetic moments follows the same rules as the proton disorder in water ice. Excitations take the form of magnetic monopoles that interact via a magnetic Coulomb interaction. Muon spin rotation has been used to probe the low-temperature magnetic behaviour in single crystal Ho2-xYxTi2O7 (x = 0, 0.1, 1, 1.6 and 2). At very low temperatures, a linear field dependence for the relaxation rate of the muon precession λ(B), that in some previous experiments on Dy2Ti2O7 spin ice has been associated with monopole currents, is observed in samples with x = 0, and 0.1. A signal from the magnetic fields penetrating into the silver sample plate due to the magnetization of the crystals is observed for all the samples containing Ho allowing us to study the unusual magnetic dynamics of Y doped spin ice.

  20. Spin structure function measurements with polarized protons and electrons at HERA

    International Nuclear Information System (INIS)

    Ball, R.D.; Deshpande, A.; Forte, S.; Hughes, V.W.; Lichtenstadt, J.; Ridolfi, G.

    1995-01-01

    Useful insights into the spin structure functions of the nucleon can be achieved by measurements of spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA. Such an experiment would be a natural extension of the polarized lepton-nucleon scattering experiments presently carried out at CERN and SLAC. We present here estimates of possible data in the extended kinematic range of HERA and associated statistical errors. (orig.)

  1. Quantum interference measurement of spin interactions in a bio-organic/semiconductor device structure

    Science.gov (United States)

    Deo, Vincent; Zhang, Yao; Soghomonian, Victoria; Heremans, Jean J.

    2015-03-01

    Quantum interference is used to measure the spin interactions between an InAs surface electron system and the iron center in the biomolecule hemin in nanometer proximity in a bio-organic/semiconductor device structure. The interference quantifies the influence of hemin on the spin decoherence properties of the surface electrons. The decoherence times of the electrons serve to characterize the biomolecule, in an electronic complement to the use of spin decoherence times in magnetic resonance. Hemin, prototypical for the heme group in hemoglobin, is used to demonstrate the method, as a representative biomolecule where the spin state of a metal ion affects biological functions. The electronic determination of spin decoherence properties relies on the quantum correction of antilocalization, a result of quantum interference in the electron system. Spin-flip scattering is found to increase with temperature due to hemin, signifying a spin exchange between the iron center and the electrons, thus implying interactions between a biomolecule and a solid-state system in the hemin/InAs hybrid structure. The results also indicate the feasibility of artificial bioinspired materials using tunable carrier systems to mediate interactions between biological entities.

  2. Measuring Parameters of Massive Black Hole Binaries with Partially Aligned Spins

    Science.gov (United States)

    Lang, Ryan N.; Hughes, Scott A.; Cornish, Neil J.

    2011-01-01

    The future space-based gravitational wave detector LISA will be able to measure parameters of coalescing massive black hole binaries, often to extremely high accuracy. Previous work has demonstrated that the black hole spins can have a strong impact on the accuracy of parameter measurement. Relativistic spin-induced precession modulates the waveform in a manner which can break degeneracies between parameters, in principle significantly improving how well they are measured. Recent studies have indicated, however, that spin precession may be weak for an important subset of astrophysical binary black holes: those in which the spins are aligned due to interactions with gas. In this paper, we examine how well a binary's parameters can be measured when its spins are partially aligned and compare results using waveforms that include higher post-Newtonian harmonics to those that are truncated at leading quadrupole order. We find that the weakened precession can substantially degrade parameter estimation, particularly for the "extrinsic" parameters sky position and distance. Absent higher harmonics, LISA typically localizes the sky position of a nearly aligned binary about an order of magnitude less accurately than one for which the spin orientations are random. Our knowledge of a source's sky position will thus be worst for the gas-rich systems which are most likely to produce electromagnetic counterparts. Fortunately, higher harmonics of the waveform can make up for this degradation. By including harmonics beyond the quadrupole in our waveform model, we find that the accuracy with which most of the binary's parameters are measured can be substantially improved. In some cases, the improvement is such that they are measured almost as well as when the binary spins are randomly aligned.

  3. Electron spin dynamics of Ce.sup.3+./sup. ions in YAG crystals studied by pulse-EPR and pump-probe Faraday rotation

    Czech Academy of Sciences Publication Activity Database

    Azamat, Dmitry; Belykh, V.V.; Yakovlev, D.R.; Fobbe, F.; Feng, D.H.; Evers, E.; Jastrabík, Lubomír; Dejneka, Alexandr; Bayer, M.

    2017-01-01

    Roč. 96, č. 7 (2017), s. 1-10, č. článku 075160. ISSN 2469-9950 R&D Projects: GA MŠk LO1409; GA ČR GA16-22092S Institutional support: RVO:68378271 Keywords : electron spin dynamics * Ce 3+ ions * YAG crystals * pulse-EPR * Faraday rotation Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

  4. Quantum measurements between a single spin and a torsional nanomechanical resonator

    Science.gov (United States)

    D'Urso, B.; Gurudev Dutt, M. V.; Dhingra, S.; Nusran, N. M.

    2011-04-01

    While the motions of macroscopic objects must ultimately be governed by quantum mechanics, the distinctive features of quantum mechanics can be hidden or washed out by thermal excitations and coupling to the environment. We propose a system consisting of a graphene nanomechanical oscillator (NMO) coupled with a single spin through a uniform external magnetic field, which could become the building block for a wide range of quantum nanomechanical devices. The choice of graphene as the NMO material is critical for minimizing the moment of inertia of the oscillator. The spin originates from a nitrogen-vacancy (NV) center in a diamond nanocrystal that is positioned on the NMO. This coupling results in quantum non-demolition (QND) measurements of the oscillator and spin states, enabling a bridge between the quantum and classical worlds for a simple readout of the NV center spin and observation of the discrete states of the NMO.

  5. MEASUREMENT OF THE RESISTIVE WALL MODE STABILITY IN A ROTATING PLASMA USING ACTIVE MHD SPECTROSCOPY

    International Nuclear Information System (INIS)

    CHU, M.S; JACKSON, G.L; LA HAYE, R.J; SCOVILLE, J.T; STRAIT, E.J

    2003-01-01

    The stability of the resistive-wall mode (RWM) in DIII-D plasmas above the conventional pressure limit, where toroidal plasma rotation in the order of a few percent of the Alfven velocity is sufficient to stabilize the n=1 RWM, has been probed using the technique of active MHD spectroscopy at frequencies of a few Hertz. The measured frequency spectrum of the plasma response to externally applied rotating resonant magnetic fields is well described by a single mode approach and provides an absolute measurement of the damping rate and the natural mode rotation frequency of the stable RWM

  6. Thermographic measurements of the spin Peltier effect in metal/yttrium-iron-garnet junction systems

    Science.gov (United States)

    Daimon, Shunsuke; Uchida, Ken-ichi; Iguchi, Ryo; Hioki, Tomosato; Saitoh, Eiji

    2017-07-01

    The spin Peltier effect (SPE), heat-current generation due to spin-current injection, in various metal (Pt, W, and Au single layers and Pt/Cu bilayer)/ferrimagnetic insulator [yttrium-iron-garnet (YIG)] junction systems has been investigated by means of a lock-in thermography (LIT) method. The SPE is excited by a spin current across the metal/YIG interface, which is generated by applying a charge current to the metallic layer via the spin Hall effect. The LIT method enables the thermal imaging of the SPE free from the Joule-heating contribution. Importantly, we observed spin-current-induced temperature modulation not only in the Pt/YIG and W/YIG systems, but also in the Au/YIG and Pt/Cu/YIG systems, excluding the possible contamination by anomalous Ettingshausen effects due to proximity-induced ferromagnetism near the metal/YIG interface. As demonstrated in our previous study, the SPE signals are confined only in the vicinity of the metal/YIG interface; we buttress this conclusion by reducing a spatial blur due to thermal diffusion in an infrared-emission layer on the sample surface used for the LIT measurements. We also found that the YIG-thickness dependence of the SPE is similar to that of the spin Seebeck effect measured in the same Pt/YIG sample, implying the reciprocal relation between them.

  7. First Measurements of Spin Correlation Using Semi-leptonic $t\\bar{t}$ Events at ATLAS

    CERN Document Server

    Lemmer, Boris; The ATLAS collaboration

    2014-01-01

    The top quark decays before it hadronizes. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular distributions of the decay products. The Standard Model predicts the top/anti-top quark ($t\\bar{t}$) pairs to have correlated spins. The degree is sensitive to the spin and the production mechanisms of the top quark. Measuring the spin correlation allows to test the predictions. New physics effects can be reflected in deviations from the prediction. The measurement of the spin correlation of $t\\bar{t}$ pairs, produced at the LHC with a center-of-mass energy of $\\sqrt{s} = 7$ TeV and reconstructed with the ATLAS detector, is presented. The dataset corresponds to an integrated luminosity of 4.6 $\\textrm{fb}^{-1}$. $t\\bar{t}$ pairs are reconstructed in the $\\ell$+jets channel using a kinematic likelihood fit offering the identification of light up- and down-type quarks from the $t \\righ...

  8. Measurement of instantaneous rotational speed using double-sine-varying-density fringe pattern

    Science.gov (United States)

    Zhong, Jianfeng; Zhong, Shuncong; Zhang, Qiukun; Peng, Zhike

    2018-03-01

    Fast and accurate rotational speed measurement is required both for condition monitoring and faults diagnose of rotating machineries. A vision- and fringe pattern-based rotational speed measurement system was proposed to measure the instantaneous rotational speed (IRS) with high accuracy and reliability. A special double-sine-varying-density fringe pattern (DSVD-FP) was designed and pasted around the shaft surface completely and worked as primary angular sensor. The rotational angle could be correctly obtained from the left and right fringe period densities (FPDs) of the DSVD-FP image sequence recorded by a high-speed camera. The instantaneous angular speed (IAS) between two adjacent frames could be calculated from the real-time rotational angle curves, thus, the IRS also could be obtained accurately and efficiently. Both the measurement principle and system design of the novel method have been presented. The influence factors on the sensing characteristics and measurement accuracy of the novel system, including the spectral centrobaric correction method (SCCM) on the FPD calculation, the noise sources introduce by the image sensor, the exposure time and the vibration of the shaft, were investigated through simulations and experiments. The sampling rate of the high speed camera could be up to 5000 Hz, thus, the measurement becomes very fast and the change in rotational speed was sensed within 0.2 ms. The experimental results for different IRS measurements and characterization of the response property of a servo motor demonstrated the high accuracy and fast measurement of the proposed technique, making it attractive for condition monitoring and faults diagnosis of rotating machineries.

  9. Simultaneous measurements of spin observables AN and ANN in elastic pp scattering (extension of the SPASCHARM program at U-70).

    Science.gov (United States)

    Abramov, V. V.; Bogdanov, A. A.; Chetvertkov, M. A.; Chetvertkova, V. A.; Mochalov, V. V.; Moiseev, V. V.; Novikov, K. D.; Nurushev, S. B.; Nurusheva, M. B.; Okorokov, V. A.; Semenov, P. A.; Strikhanov, M. N.; Vasiliev, A. N.

    2017-12-01

    We propose to measure spin observables AN and ANN in elastic pp scattering by using the transversely polarized proton beam and target at momenta p = 12-45 GeV/c. Existence of both polarized target and beam gives us unique possibility to measure AN simultaneously and independently for polarized beam (AB) and target (AT) to carry out and verify experimental measurements of single-spin and double-spin (ANN) measurements in diffractive region.

  10. Validity of the Digital Inclinometer and iPhone When Measuring Thoracic Spine Rotation.

    Science.gov (United States)

    Bucke, Jonathan; Spencer, Simon; Fawcett, Louise; Sonvico, Lawrence; Rushton, Alison; Heneghan, Nicola R

    2017-09-01

      Spinal axial rotation is required for many functional and sporting activities. Eighty percent of axial rotation occurs in the thoracic spine. Existing measures of thoracic spine rotation commonly involve laboratory equipment, use a seated position, and include lumbar motion. A simple performance-based outcome measure would allow clinicians to evaluate isolated thoracic spine rotation. Currently, no valid measure exists.   To explore the criterion and concurrent validity of a digital inclinometer (DI) and iPhone Clinometer app (iPhone) for measuring thoracic spine rotation using the heel-sit position.   Controlled laboratory study.   University laboratory.   A total of 23 asymptomatic healthy participants (14 men, 9 women; age = 25.82 ± 4.28 years, height = 170.26 ± 8.01 cm, mass = 67.50 ± 9.46 kg, body mass index = 23.26 ± 2.79) were recruited from a student population.   We took DI and iPhone measurements of thoracic spine rotation in the heel-sit position concurrently with dual-motion analysis (laboratory measure) and ultrasound imaging of the underlying bony tissue motion (reference standard). To determine the criterion and concurrent validity, we used the Pearson product moment correlation coefficient (r, 2 tailed) and Bland-Altman plots.   The DI (r = 0.88, P iPhone (r = 0.88, P iPhone, respectively, and the reference standard and 0.87° (95% CI = 6.79°, -5.05°) between the DI and iPhone.   The DI and iPhone provided valid measures of thoracic spine rotation in the heel-sit position. Both can be used in clinical practice to assess thoracic spine rotation, which may be valuable when evaluating thoracic dysfunction.

  11. Rotating machinery vibration analysis of the rotary-laser scanning measurement system

    Science.gov (United States)

    Guo, Siyang; Ren, Yongjie; Shi, Shendong; Yang, Linghui; Lin, Jiarui

    2018-01-01

    The workshop Measurement and Positioning System (wMPS) based on the rotary-laser scanning technology has been widely applied in the manufacturing industry to provide an accurate and robust coordinate measurement. However, some vibration-related problems in the rotating machinery inevitably exist. These problems influence the measurement accuracy of wMPS and even reduce its service life. In this paper, the rotating machinery vibration analysis of wMPS is introduced. Some significant factors causing vibrations, such as the mass imbalance of the rotor, are discussed. The vibration signals of rotating machinery are captured experimentally by the three-axis accelerometer. These raw vibration signals are processed by the data pretreatment, the time-domain analysis and the frequency-domain analysis. Based on these analyses, some evaluation criteria of rotating machinery vibration are introduced. These criteria provide guidance to the fault detection and ensure the ongoing operational condition of wMPS.

  12. An overview of recent nucleon spin structure measurements at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Allada, Kalyan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-02-01

    Jefferson Lab have made significant contributions to improve our knowledge of the longitudinal spin structure by measuring polarized structure functions, g1 and g2, down to Q2 = 0.02 GeV2. The low Q2 data is especially useful in testing the Chiral Perturbation theory (cPT) calculations. The spin-dependent sum rules and the spin polarizabilities, constructed from the moments of g1 and g2, provide an important tool to study the longitudinal spin structure. We will present an overview of the experimental program to measure these structure functions at Jefferson Lab, and present some recent results on the neutron polarizabilities, proton g1 at low Q2, and proton and neutron d2 measurement. In addition to this, we will discuss the transverse spin structure of the nucleon which can be accessed using chiral-odd transversity distribution (h1), and show some results from measurements done on polarized 3He target in Hall A.

  13. Asteroseismic measurement of surface-to-core rotation in a main-sequence star*

    Directory of Open Access Journals (Sweden)

    Kurtz Donald W.

    2015-01-01

    Full Text Available We have discovered rotationally split core g-mode triplets and surface p-mode triplets and quintuplets in a terminal age main-sequence A star, KIC 11145123, that shows both δ Sct p-mode pulsations and γ Dor g-mode pulsations. This gives the first robust determination of the rotation of the deep core and surface of a main-sequence star, essentially model-independently. We find its rotation to be nearly uniform with a period near 100 d, but we show with high confidence that the surface rotates slightly faster than the core. A strong angular momentum transfer mechanism must be operating to produce the nearly rigid rotation, and a mechanism other than viscosity must be operating to produce a more rapidly rotating surface than core. Our asteroseismic result, along with previous asteroseismic constraints on internal rotation in some B stars, and measurements of internal rotation in some subgiant, giant and white dwarf stars, has made angular momentum transport in stars throughout their lifetimes an observational science.

  14. Lock-in thermography measurements of the spin Peltier effect in a compensated ferrimagnet and its comparison to the spin Seebeck effect

    Science.gov (United States)

    Yagmur, A.; Iguchi, R.; Geprägs, S.; Erb, A.; Daimon, S.; Saitoh, E.; Gross, R.; Uchida, K.

    2018-05-01

    The spin Peltier effect (SPE) in a junction comprising a gadolinium-iron-garnet (GdIG) slab and a Pt film has been investigated around the magnetization compensation temperature of GdIG by means of the lock-in thermography method. When a charge current is applied to the Pt layer, a spin current is generated across the Pt/GdIG interface via the spin Hall effect in Pt. This spin current induces a heat current and a measurable temperature change near the Pt/GdIG interface due to the SPE. The SPE signal in the Pt/GdIG junction shows a sign change around the magnetization compensation temperature, demonstrating the similar temperature dependence of the SPE and the spin Seebeck effect for the Pt/GdIG hybrid system.

  15. Measurement of the proton $A_1$ and $A_2$ spin asymmetries. Probing Color Forces

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Whitney [Temple University, Philadelphia, PA (United States)

    2015-05-01

    The Spin Asymmetries of the Nucleon Experiment (SANE) measured the proton spin structure function $g_2$ in a range of Bjorken x, 0.3 < x < 0.8, where extraction of the twist-3 matrix element $d_2^p$ (an integral of $g_2$ weighted by $x^2$) is most sensitive. The data was taken from $Q^2$ equal to 2.5 $GeV^2$ up to 6.5 $GeV^2$. In this polarized electron scattering off a polarized hydrogen target experiment, two double spin asymmetries, A∥ and A⊥ were measured using the BETA (Big Electron Telescope Array) Detector. BETA consisted of a scintillator hodoscope, gas Cerenkov counter, lucite hodoscope and a large lead glass electromagnetic calorimeter. With a unique open geometry, a threshold gas Cerenkov detector allowed BETA to cleanly identify electrons for this inclusive experiment. A measurement of $d_2^p$ is compared to lattice QCD calculations.

  16. An Air Bearing Balance with 1-DOF Spin Capability

    National Research Council Canada - National Science Library

    Magill, J. C; McManus, K. R; Malonson, M. R; Ziehler, J. A; Hinds, M. F

    1998-01-01

    .... Five load components are measured by sensing pressures in the air bearing film. The sixth component - rolling torque - is determined by sensing the current needed by the brushless spin motor to maintain a given rotation rate...

  17. What can we learn about the dynamics of transported spins by measuring shot noise in spin–orbit-coupled nanostructures?

    International Nuclear Information System (INIS)

    Nikolić, Branislav K; Dragomirova, Ralitsa L

    2009-01-01

    We review recent studies of the shot noise of spin-polarized charge currents and pure spin currents in multiterminal semiconductor nanostructures, while focusing on the effects brought by the intrinsic Rashba spin–orbit (SO) coupling and/or extrinsic SO scattering off impurities in two-dimensional electron gas (2DEG) based devices. By generalizing the scattering theory of quantum shot noise to include the full spin-density matrix of electrons injected from a spin-filtering electrode, we show how decoherence and dephasing in the course of spin precession can lead to the substantial enhancement of the Fano factor (noise-to-current ratio) of spin-polarized charge currents. These processes are suppressed by decreasing the width of the diffusive Rashba wire, so that purely electrical measurement of the shot noise in a ferromagnet|SO-coupled-diffusive-wire|paramagnet setup can quantify the degree of quantum coherence of transported spin through a remarkable one-to-one correspondence between the purity of the spin state and the Fano factor. In four-terminal SO-coupled nanostructures, injection of unpolarized charge current through the longitudinal leads is responsible not only for the pure spin Hall current in the transverse leads, but also for nonequilibrium random time-dependent current fluctuations. The analysis of the shot noise of transverse pure spin Hall current and zero charge current, or transverse spin current and non-zero charge Hall current, driven by unpolarized or spin-polarized injected longitudinal charge current, respectively, reveals a unique experimental tool to differentiate between the intrinsic Rashba and extrinsic SO mechanisms underlying the spin Hall effect in 2DEG devices. When the intrinsic mechanisms responsible for spin precession start to dominate the spin Hall effect, they also enhance the shot noise of transverse spin and charge transport in multiterminal geometries. Finally, we discuss the shot noise of transverse spin and zero charge

  18. Misalignment Effect Function Measurement for Oblique Rotation Axes: Counterintuitive Predictions and Theoretical Extensions

    Science.gov (United States)

    Ellis, Stephen R.; Adelstein, Bernard D.; Yeom, Kiwon

    2013-01-01

    The Misalignment Effect Function (MEF) describes the decrement in manual performance associated with a rotation between operators' visual display frame of reference and that of their manual control. It now has been empirically determined for rotation axes oblique to canonical body axes and is compared with the MEF previously measured for rotations about canonical axes. A targeting rule, called the Secant Rule, based on these earlier measurements is derived from a hypothetical process and shown to describe some of the data from three previous experiments. It explains the motion trajectories determined for rotations less than 65deg in purely kinematic terms without the need to appeal to a mental rotation process. Further analysis of this rule in three dimensions applied to oblique rotation axes leads to a somewhat surprising expectation that the difficulty posed by rotational misalignment should get harder as the required movement is shorter. This prediction is confirmed. Geometry underlying this rule also suggests analytic extensions for predicting more generally the difficulty of making movements in arbitrary directions subject to arbitrary misalignments.

  19. Optical derotator alignment using image-processing algorithm for tracking laser vibrometer measurements of rotating objects

    Science.gov (United States)

    Khalil, Hossam; Kim, Dongkyu; Jo, Youngjoon; Park, Kyihwan

    2017-06-01

    An optical component called a Dove prism is used to rotate the laser beam of a laser-scanning vibrometer (LSV). This is called a derotator and is used for measuring the vibration of rotating objects. The main advantage of a derotator is that it works independently from an LSV. However, this device requires very specific alignment, in which the axis of the Dove prism must coincide with the rotational axis of the object. If the derotator is misaligned with the rotating object, the results of the vibration measurement are imprecise, owing to the alteration of the laser beam on the surface of the rotating object. In this study, a method is proposed for aligning a derotator with a rotating object through an image-processing algorithm that obtains the trajectory of a landmark attached to the object. After the trajectory of the landmark is mathematically modeled, the amount of derotator misalignment with respect to the object is calculated. The accuracy of the proposed method for aligning the derotator with the rotating object is experimentally tested.

  20. Differential detection for measurements of Faraday rotation by means of ac magnetic fields

    International Nuclear Information System (INIS)

    Valev, V K; Wouters, J; Verbiest, T

    2008-01-01

    We demonstrate that by using a combination of a Wollaston prism and two photodiodes the accuracy in the measurements of Faraday rotation with ac magnetic fields can be greatly improved. Our experiments were performed on microscope cover glass plates with thicknesses between 0.13 and 0.16 mm. We show that our setup is capable of distinguishing between the Faraday rotation signals of glass plates having a difference in thickness of a few micrometers, corresponding to Faraday rotations of hundreds of microdegrees per Tesla only

  1. Vertebral rotation measurement: a summary and comparison of common radiographic and CT methods

    Directory of Open Access Journals (Sweden)

    Le Lawrence H

    2008-11-01

    Full Text Available Abstract Current research has provided a more comprehensive understanding of Adolescent Idiopathic Scoliosis (AIS as a three-dimensional spinal deformity, encompassing both lateral and rotational components. Apart from quantifying curve severity using the Cobb angle, vertebral rotation has become increasingly prominent in the study of scoliosis. It demonstrates significance in both preoperative and postoperative assessment, providing better appreciation of the impact of bracing or surgical interventions. In the past, the need for computer resources, digitizers and custom software limited studies of rotation to research performed after a patient left the scoliosis clinic. With advanced technology, however, rotation measurements are now more feasible. While numerous vertebral rotation measurement methods have been developed and tested, thorough comparisons of these are still relatively unexplored. This review discusses the advantages and disadvantages of six common measurement techniques based on technology most pertinent in clinical settings: radiography (Cobb, Nash-Moe, Perdriolle and Stokes' method and computer tomography (CT imaging (Aaro-Dahlborn and Ho's method. Better insight into the clinical suitability of rotation measurement methods currently available is presented, along with a discussion of critical concerns that should be addressed in future studies and development of new methods.

  2. On the potential of seismic rotational motion measurements for extraterrestrial seismology

    Science.gov (United States)

    Schmelzbach, Cedric; Sollberger, David; Khan, Amir; Greenhalgh, Stewart; Van Renterghem, Cederic; Robertsson, Johan

    2017-04-01

    Classically, seismological recordings consist of measurements of translational ground motion only. However, in addition to three vector components of translation there are three components of rotation to consider, leading to six degrees of freedom. Of particular interest is thereby the fact that measuring rotational motion means isolating shear (S) waves. Recording the rotational motion requires dedicated rotational sensors. Alternatively, since the rotational motion is given by the curl of the vectorial displacements, the rotational motion around the two horizontal axes can be computed from the horizontal spatial gradients of vertical translational recordings if standard translational seismometers are placed in an areal array at the free surface. This follows from the zero stress free surface condition. Combining rotational and translational motion measurements opens up new ways of analyzing seismic data, such as facilitating much improved arrival identification and wavefield separation (e.g., P-/S-wave separation), and local slowness (arrival direction and velocity) determination. Such combined measurements maximize the seismic information content that a single six-component station or a small station array can provide, and are of particular interest for sparse or single-station measurements such as in extraterrestrial seismology. We demonstrate the value of the analysis of combined translational and rotational recordings by re-evaluating data from the Apollo 17 lunar seismic profiling experiment (LSPE). The LSPE setup consisted of four vertical-component geophones arranged in a star-like geometry. This areal receiver layout enables computing the horizontal spatial gradients by spatial finite differencing of the vertical-component data for two perpendicular directions and, hence, the estimation of rotational motion around two horizontal axes. Specifically, the recorded seismic waveform data originated from eight explosive packages as well as from continuously

  3. Output-only cyclo-stationary linear-parameter time-varying stochastic subspace identification method for rotating machinery and spinning structures

    Science.gov (United States)

    Velazquez, Antonio; Swartz, R. Andrew

    2015-02-01

    Economical maintenance and operation are critical issues for rotating machinery and spinning structures containing blade elements, especially large slender dynamic beams (e.g., wind turbines). Structural health monitoring systems represent promising instruments to assure reliability and good performance from the dynamics of the mechanical systems. However, such devices have not been completely perfected for spinning structures. These sensing technologies are typically informed by both mechanistic models coupled with data-driven identification techniques in the time and/or frequency domain. Frequency response functions are popular but are difficult to realize autonomously for structures of higher order, especially when overlapping frequency content is present. Instead, time-domain techniques have shown to possess powerful advantages from a practical point of view (i.e. low-order computational effort suitable for real-time or embedded algorithms) and also are more suitable to differentiate closely-related modes. Customarily, time-varying effects are often neglected or dismissed to simplify this analysis, but such cannot be the case for sinusoidally loaded structures containing spinning multi-bodies. A more complex scenario is constituted when dealing with both periodic mechanisms responsible for the vibration shaft of the rotor-blade system and the interaction of the supporting substructure. Transformations of the cyclic effects on the vibrational data can be applied to isolate inertial quantities that are different from rotation-generated forces that are typically non-stationary in nature. After applying these transformations, structural identification can be carried out by stationary techniques via data-correlated eigensystem realizations. In this paper, an exploration of a periodic stationary or cyclo-stationary subspace identification technique is presented here for spinning multi-blade systems by means of a modified Eigensystem Realization Algorithm (ERA) via

  4. The rotating particles probe: a new technique to measure interactions between particles and a substrate

    NARCIS (Netherlands)

    Janssen, X.J.A.; Van Reenen, A.; Van IJzendoorn, L.J.; De Jong, A.M.; Prins, M.W.J.

    2012-01-01

    We demonstrate a new probing technique to measure physicochemical interactions between particles and a substrate in a fluid. The technique is based on the measurement of field-induced rotation of individual magnetic particles in contact with the substrate. The parallel measurement of many particles

  5. Measurement of a time-periodic magnetic field by rotating coil

    International Nuclear Information System (INIS)

    Marusov, V.

    2013-01-01

    A novel technique of the measurement data processing is developed which allows to apply the rotating coil method for measurement of a dynamic magnetic field, periodic in time. The developed technique allows to obtain time-dependent multipoles in a single measurement which takes place during one power cycle of the magnet or the coil rotation period, whichever is longer. -- Highlights: ► The rotating coil method is commonly used for measurement of a static field. ► A novel technique is developed to use it for measurement of a time-periodic field. ► Field multipoles are presented as Fourier time series with unknown coefficients. ► The Fourier series translation properties are used to obtain additional equations. ► A complete set of equations with Vandermonde matrices is derived to find unknowns

  6. Measuring Parameters of Massive Black Hole Binaries with Partially-Aligned Spins

    Science.gov (United States)

    Lang, Ryan N.; Hughes, Scott A.; Cornish, Neil J.

    2010-01-01

    It is important to understand how well the gravitational-wave observatory LISA can measure parameters of massive black hole binaries. It has been shown that including spin precession in the waveform breaks degeneracies and produces smaller expected parameter errors than a simpler, precession-free analysis. However, recent work has shown that gas in binaries can partially align the spins with the orbital angular momentum, thus reducing the precession effect. We show how this degrades the earlier results, producing more pessimistic errors in gaseous mergers. However, we then add higher harmonics to the signal model; these also break degeneracies, but they are not affected by the presence of gas. The harmonics often restore the errors in partially-aligned binaries to the same as, or better than/ those that are obtained for fully precessing binaries with no harmonics. Finally, we investigate what LISA measurements of spin alignment can tell us about the nature of gas around a binary,

  7. Why Are Rapidly Rotating M Dwarfs in the Pleiades so (Infra)red? New Period Measurements Confirm Rotation-dependent Color Offsets From the Cluster Sequence

    Science.gov (United States)

    Covey, Kevin R.; Agüeros, Marcel A.; Law, Nicholas M.; Liu, Jiyu; Ahmadi, Aida; Laher, Russ; Levitan, David; Sesar, Branimir; Surace, Jason

    2016-05-01

    Stellar rotation periods (P rot) measured in open clusters have proved to be extremely useful for studying stars’ angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P rot measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (measured from photometric monitoring of the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P rot with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P rot and position relative to the main sequence in the cluster's color-magnitude diagram. We find that rapid rotators have redder (V - K) colors than slower rotators at the same V, indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.

  8. Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Le Chat, G.; Cohen, O. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Kasper, J. C. [Atmospheric, Oceanic and Space Sciences Department, University of Michigan, Ann Arbor, MI (United States); Spangler, S. R., E-mail: gaetan.lechat@obspm.fr [Department of Physics and Astronomy, University of Iowa, Iowa City, IA (United States)

    2014-07-10

    Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

  9. Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

    International Nuclear Information System (INIS)

    Le Chat, G.; Cohen, O.; Kasper, J. C.; Spangler, S. R.

    2014-01-01

    Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

  10. Measuring the rotation period distribution of field M dwarfs with Kepler

    Science.gov (United States)

    McQuillan, A.; Aigrain, S.; Mazeh, T.

    2013-06-01

    We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55 M⊙. To derive the rotational period, we introduce the autocorrelation function and show that it is robust against phase and amplitude modulation and residual instrumental systematics. Of the 2483 stars examined, we detected rotation periods in 1570 (63.2 per cent), representing an increase of a factor of ˜30 in the number of rotation period determination for field M dwarfs. The periods range from 0.37 to 69.7 d, with amplitudes ranging from 1.0 to 140.8 mmag. The rotation period distribution is clearly bimodal, with peaks at ˜19 and ˜33 d, hinting at two distinct waves of star formation, a hypothesis that is supported by the fact that slower rotators tend to have larger proper motions. The two peaks of the rotation period distribution form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature, reminiscent of the Vaughan-Preston gap. The period-mass distribution of our sample shows no evidence of a transition at the fully convective boundary. On the other hand, the slope of the upper envelope of the period-mass relation changes sign around 0.55 M⊙, below which period rises with decreasing mass.

  11. Distinguishing the laser-induced spin precession excitation mechanism in Fe/MgO(001) through field orientation dependent measurements

    Science.gov (United States)

    Ma, T. P.; Zhang, S. F.; Yang, Y.; Chen, Z. H.; Zhao, H. B.; Wu, Y. Z.

    2015-01-01

    Rotational field dependence of laser-induced magnetization precession in a single-crystal Fe/MgO(001) sample was studied by the time resolved magneto-optical Kerr effect. Polar and longitudinal magnetization components were separated by measuring precession dynamics under opposite fields. When the applied field is weaker than the anisotropy field of an Fe film, the precession amplitude is small for the field direction near the easy axis and becomes larger as the field rotates towards the hard axis, showing a four-fold symmetry in agreement with the in-plane magnetic anisotropy; whereas at higher fields, the amplitude displays a drop near the hard axis. Such precession behavior can be well reproduced using an excitation model with rapidly modified but slowly recovered magnetic anisotropy and considering the elliptical precession trajectory. Our results indicate that the dominant mechanism for triggering Fe spin precession is the anisotropy modulation correlating with the lattice thermalization, rather than the transient anisotropy modulation due to the high electron temperature within 1 ps.

  12. Tube-AVB gap measurements using an eddy current rotating probe

    International Nuclear Information System (INIS)

    Badson, F.; Chiron, D.; Trumpff, B.

    1988-01-01

    The wears of tubes due to flow induced vibrations have been observed after a few years of operating PWR steam generators (SG). The vibration and wear are intimately related to the gap between tubes and anti-vibration bars (AVB's) located in the bundle. The authors report the development of an eddy current (EC) method for the measurement of this gap. The method is based on using an EC probe rotating in the tube. Since for each measurement zone the tube is interacting with two AVB's the use of a rotating EC probe is necessary to perform separate and accurate measurements of each tube-AVB gap

  13. Simultaneous measurement of line electron density and Faraday rotation in the ISX-B tokamak

    International Nuclear Information System (INIS)

    Hutchinson, D.P.; Ma, C.H.; Staats, P.A.; Vander Sluis, K.L.

    1981-01-01

    A new diagnostic system utilizing a submillimetre-wave, phase-modulated polarimeter/interferometer has been used to simultaneously measure the time evolution of the line-averaged electron density and poloidal field-induced Faraday rotation in the ISX-B tokamak. The measurements, performed along four chords of the plasma column, have been correlated with poloidal field changes associated with a ramp in the Ohmic-heating current and by neutral-beam injection. These are the first simultaneous measurements of line electron density and Faraday rotation to be made along a chord of submillimetre laser beam in a tokamak plasma. (author)

  14. Measurements of decreasing lattice thermal conductivity of ferropericlase across the high-spin to mixed-spin state.

    Science.gov (United States)

    McGuire, C. P.; Sawchuk, K. L. S.; Kavner, A.

    2017-12-01

    The thermal conductivity of lower mantle minerals depends on crystal structure and phase, with important implications for the style of convection in the mantle and the heat flow across the core-mantle boundary. In this study, we demonstrate how measurements of temperature in the laser-heated diamond anvil cell (LHDAC) can be used to determine relative changes in thermal conductivity across a pressure-induced phase change. A finite-element 3D heat flow model of the LHDAC is used to simulate experimental conditions. Results from modeling show that the peak temperature in the cell is primarily controlled by the geometry, sample thermal conductivity and heat input due to laser heating. Controlling for geometry, the model can output expected temperature versus laser-power curves for an increase or decrease in thermal conductivity with pressure. The modeled temperature differences indicate that we can experimentally distinguish the sign and magnitude of a thermal conductivity change due to a pressure-induced phase change. We perform a series of experiments to test our models. In one set of experiments, we measure temperature versus laser-power as a function of pressure for the NaCl B1-B2 phase transition, over the pressure range 18 to 54 GPa. A decrease in thermal conductivity across the NaCl B1-B2 phase transition (dκ/dP = -1.6 +/- 0.2 W/(mK GPa)) is needed to explain our measurements. This result is consistent with thermal conductivity measurements of other ionic salts, which undergo the B1-B2 phase transition at much lower pressure. We apply this experiment design to investigate the effect of spin transition on an iron-bearing magnesium oxide sample. In a series of experiments, we measure temperature vs. laser power for (Mg,Fe)O with 24 mol% Fe, loaded in Ne, over a pressure range from 22 to 60 GPa. We observe an increase in thermal conductivity between 22 and 42 GPa. But between 42 and 60 GPa, a pressure range consistent with previously reported mixed-spin state

  15. The Proton Spin, Semi-Inclusive processes, and measurements at a future Electron Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Abhay, Deshpande

    2018-01-12

    We discuss spin physics, Guido’s contribution to it, and what we still have to learn. We set out in particular a programme for incorporating constraints from semi-inclusive data into global fits of polarized PDFs, and discuss the need for the EIC to increase the precision and kinematic coverage of current measurements.

  16. Separation of Rashba and Dresselhaus spin-orbit interactions using crystal direction dependent transport measurements

    International Nuclear Information System (INIS)

    Ho Park, Youn; Kim, Hyung-jun; Chang, Joonyeon; Hee Han, Suk; Eom, Jonghwa; Choi, Heon-Jin; Cheol Koo, Hyun

    2013-01-01

    The Rashba spin-orbit interaction effective field is always in the plane of the two-dimensional electron gas and perpendicular to the carrier wavevector but the direction of the Dresselhaus field depends on the crystal orientation. These two spin-orbit interaction parameters can be determined separately by measuring and analyzing the Shubnikov-de Haas oscillations for various crystal directions. In the InAs quantum well system investigated, the Dresselhaus term is just 5% of the Rashba term. The gate dependence of the oscillation patterns clearly shows that only the Rashba term is modulated by an external electric field

  17. Measurement of the spin structure of the neutron using polarised deep inelastic scattering

    Science.gov (United States)

    Kaiser, Ralf Bernd

    The measurement of the spin structure function g1p of the proton and its integral Γ1p by the EMC experiment at C scERN in 1988 indicated that only 12% ± 17% of the proton spin is carried by quarks. This unexpected result-the so called 'spin crisis'-lead to a series of new experimental proposals. One of these, the H scERMES experiment, uses the polarised positron beam of the H scERA accelerator together with a polarised internal gas target of hydrogen, deuterium or 3He for the study of the spin structure of the nucleon. The scattered positrons and other products of the reaction are detected in a forward spectrometer with large acceptance. This thesis focuses on three topics, after a review of the relevant theory and an overview of the H scERMES experiment: The H scERMES transition radiation detector (TRD), which is used to distinguish high energy positrons from hadrons, the H scERMES particle identification (PID) system and the measurement of the spin structure function g1n of the neutron. The H scERMES TRD is the main Canadian contribution to the apparatus of the experiment. The H scERMES PID system allows the identification of positrons from deep inelastic scattering with an efficiency of 99% and a hadron contamination of less than 0.5%. The first physics result from the 1995 H scERMES data is the measurement of the spin structure function g1n(x) of the neutron. The value of the resulting integral Γ1n=∫01g1n(x)/ dx confirms previous measurements at SLAC and violates the Ellis-Jaffe sum rule by about one sigma. The contribution of the quarks to the spin of the neutron can be calculated in the framework of the quark parton model to be 37 ± 16%, indicating that less than half of the spin of the neutron is carried by quarks.

  18. Measurement of the Spin Structure of the Deuteron in the DIS Region

    CERN Document Server

    Ageev, E.S.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Badelek, B.; Balestra, F.; Ball, J.; Baum, G.; Bedfer, Y.; Berglund, P.; Bernet, C.; Bertini, R.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Burtin, E.; Bussa, M.P.; Bytchkov, V.N.; Cerini, L.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Colavita, A.A.; Costa, S.; Crespo, M.L.; d'Hose, N.; Dalla Torre, S.; Dasgupta, S.S.; De Masi, R.; Dedek, N.; Denisov, O.Yu.; Dhara, L.; Diaz Kavka, V.; Dinkelbach, A.M.; Dolgopolov, A.V.; Donskov, S.V.; Dorofeev, V.A.; Doshita, N.; Duic, V.; Dunnweber, W.; Ehlers, J.; Eversheim, P.D.; Eyrich, W.; Fabro, M.; Faessler, M.; Falaleev, V.; Fauland, P.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franz, J.; Friedrich, J.M.; Frolov, V.; Fuchs, U.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.M.; Grajek, O.; Grasso, A.; Grube, B.; Grunemaier, A.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Hedicke, S.; Heinsius, F.H.; Hermann, R.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Ijaduola, R.B.; Ilgner, C.; Ioukaev, A.I.; Ishimoto, S.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N.I.; Kabuss, E.; Kalinnikov, V.; Kang, D.; Karstens, F.; Kastaun, W.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Khomutov, N.V.; Kisselev, Yu.; Klein, F.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, Kay; Konoplyannikov, A.K.; Konorov, I.; Konstantinov, V.F.; Korentchenko, A.S.; Korzenev, A.; Kotzinian, A.M.; Koutchinski, N.A.; Kowalik, K.; Kravchuk, N.P.; Krivokhizhin, G.V.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M.E.; Lamanna, M.; Le Goff, J.M.; Leberig, M.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Manuilov, I.V.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matsuda, T.; Maximov, A.N.; Medved, K.S.; Meyer, W.; Mielech, A.; Mikhailov, Yu.V.; Moinester, M.A.; Nahle, O.; Nassalski, J.; Neliba, S.; Neyret, D.P.; Nikolaenko, V.I.; Nozdrin, A.A.; Obraztsov, V.F.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Pereira, H.D.; Peshekhonov, D.V.; Peshekhonov, V.D.; Piragino, G.; Platchkov, S.; Platzer, K.; Pochodzalla, J.; Polyakov, V.A.; Popov, A.A.; Pretz, J.; Quintans, C.; Ramos, S.; Rebourgeard, P.C.; Reicherz, G.; Reymann, J.; Rith, K.; Rojdestvenski, A.M.; Rondio, E.; Sadovski, A.B.; Saller, E.; Samoylenko, V.D.; Sandacz, A.; Sapozhnikov, M.G.; Savin, Igor A.; Schiavon, P.; Schill, C.; Schmidt, T.; Schmitt, L.; Schmitt, H.; Shevchenko, O.Yu.; Shishkin, A.A.; Siebert, H.; Sinha, L.; Sissakian, A.N.; Skachkova, A.; Slunecka, M.; Smirnov, G.I.; Sugonyaev, V.P.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sulc, M.; Sulej, R.; Takabayashi, N.; Tchalishev, V.V.; Thers, D.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Toeda, T.; Tretyak, V.I.; Trusov, Sergey V.; Varanda, M.; Virius, M.; Vlassov, N.V.; Wagner, M.; Walcher, T.; Webb, R.; Weise, E.; Weitzel, Q.; Wiesmann, M.; Windmolders, R.; Wirth, S.; Wislicki, W.; Zanetti, A.M.; Zaremba, K.; Zhao, J.; Ziegler, R.; Zvyagin, A.

    2005-01-01

    We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.

  19. Photoexcited Muon Spin Spectroscopy: A New Method for Measuring Excess Carrier Lifetime in Bulk Silicon.

    Science.gov (United States)

    Yokoyama, K; Lord, J S; Miao, J; Murahari, P; Drew, A J

    2017-12-01

    We have measured excess carrier lifetime in silicon using photoexcited muon spin spectroscopy. Positive muons implanted deep in a wafer can interact with the optically injected excess carriers and directly probe the bulk carrier lifetime while minimizing the effect from surface recombination. The method is based on the relaxation rate of muon spin asymmetry, which depends on the excess carrier density. The underlying microscopic mechanism has been understood by simulating the four-state muonium model in Si under illumination. We apply the technique to different injection levels and temperatures, and demonstrate its ability for injection- and temperature-dependent lifetime spectroscopy.

  20. Spin Measurements of n+Sr-87 for Level Density Studies

    CERN Document Server

    Gunsing, F; Mathelie, M; Valenta, S; Bečvář, F; Rusev, G; Tonchev, A P; Mitchell, G; Baramsai, B; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Eleftheriadis, C; Ferrari, A; Ganesan, S; García, A R; Giubrone, G; Gonçalves, I.F.; González-Romero, E; Griesmayer, E; Guerrero, C; Hernández-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P F; Mastromarco, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Rubbia, C; Sabaté-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Vannini, G; Variale, V; Vaz, P; Ventura, A; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T; Žugec, P

    2014-01-01

    We have used the 4 pi BaF2 gamma-ray detector array at the n\\_TOF neutron time-of-flight facility at CERN for an experiment in order to determine the spins of resonances of n+Sr-87 by measuring the gamma-ray spectra and multiplicity distributions. The first results are presented here. We have assigned the orbital momentum l to all evaluated resonances on the basis of their neutron widths. Further we have assigned the spin J to 16 s-wave resonances on based the population of low-lying levels.

  1. Negative muon spin precession measurement of the hyperfine states of muonic sodium

    International Nuclear Information System (INIS)

    Brewer, J.H.; Ghandi, K.; Froese, A.M.; Fryer, B.A.

    2005-01-01

    Both hyperfine states of muonic 23 Na and the rate R of conversion between them have been observed directly in a high field negative muon spin precession experiment using a backward muon beam with transverse spin polarization. The result in metallic sodium, R=13.7±2.2 μs -1 , is consistent with Winston's prediction in 1963 based on Auger emission of core electrons, and with the measurements of Gorringe et al. in Na metal, but not with their smaller result in NaF. In NaOH we find R=23.5±8 μs -1 , leaving medium-dependent effects ambiguous

  2. Measurement of the transverse spin correlations in the decay $Z \\rightarrow \\tau^+\\tau^-$

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Miquel, R; Mir, L M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bazarko, A O; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Hansen, J B; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rizzo, G; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Turnbull, R M; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Spagnolo, P; Stacey, A M; Williams, M D; Ghete, V M; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Konstantinidis, N P; Leroy, O; Motsch, F; Payre, P; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Schune, M H; Simion, S; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1997-01-01

    For tau leptons produced in e^+e^- -> tau^+ tau^- interactions there are, in addition to the longitudinal spin correlations, two independent transverse spin correlations associated with the transverse (within the production plane) and normal (to the production plane) polarization components. A measurement of the transverse-transverse and transverse-normal tau spin correlations in the decay Z -> tau^+ tau^-, C_{TT} and C_{TN}, is presented based on the aplanarity angle of the decay products of both tau leptons. Using 80 pb^{-1} of data collected by ALEPH on the peak of the Z resonance, the results are C_{TT} = 1.06 +- 0.13 (stat) +- 0.05 (syst), and C_{TN} = 0.08 +- 0.13 (stat) +- 0.04 (syst). These values are in agreement with the Standard Model predictions, C_{TT} = 0.99 and C_{TN} = -0.01.

  3. Measurement of the transverse spin correlations in the decay Z -> τ+τ-

    Science.gov (United States)

    Barate, R.; Buskulic, D.; Decamp, D.; Ghez, P.; Coy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Nief, J.-Y.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Comas, P.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Miquel, R.; Mir, Ll. M.; Orteu, S.; Padilla, C.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Alemany, R.; Becker, U.; Bazarko, A. O.; Bright-Thomas, P.; Cattaneo, M.; Cerutti, F.; Dissertori, G.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Hansen, J. B.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Mato, P.; Minten, A.; Moneta, L.; Pacheco, A.; Pusztaszeri, J.-F.; Ranjard, F.; Rizzo, G.; Rolandi, L.; Rousseau, D.; Schlatter, D.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Rensch, B.; Wäänänen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Zachariadou, K.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, E.; Thomson, F.; Turnbull, R. M.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Girone, M.; Goodsir, S.; Martin, E. B.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Spagnolo, P.; Stacey, A. M.; Williams, M. D.; Ghete, V. M.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W.; Sloan, T.; Williams, M. I.; Galla, A.; Giehl, I.; Greene, A. M.; Hoffmann, C.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Leroy, O.; Motsch, F.; Payre, P.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, R.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Chen, S.; Choi, Y.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacholkowska, A.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Schune, M.-H.; Simion, S.; Tournefier, E.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Blair, G. A.; Bryant, L. M.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Kelly, M. S.; Lehto, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Charles, E.; Elmer, P.; Ferguson, D. P. S.; González, S.; Greening, T. C.; Hayes, O. J.; Hu, H.; Jin, S.; McNamara, P. A.; Nachtman, J. M.; Nielsen, J.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zobernig, G.

    1997-02-01

    For τ leptons produced in e+e- -> τ+τ- interactions there are, in addition to the longitudinal spin correlations, two independent transverse spin correlations associated with the transverse (within the production plane) and normal (to the production plane) polarization components. A measurement of the transverse-transverse and transverse-normal τ spin correlations in the decay Z -> τ+τ-, CTT and CTN, is presented based on the aplanarity angle of the decay products of both τ leptons. Using 80 pb-1 of data collected by ALEPH on the peak of the Z resonance, the results are CTT = 1.06 +/- 0.13 (stat) +/- 0.05 (syst), and CTN = 0.08 +/- 0.13 (stat) +/- 0.04 (syst). These values are in agreement with the Standard Model predictions, CTT = 0.99 and CTN = -0.01.

  4. Measurement of mean rotation and strain-rate tensors by using stereoscopic PIV

    DEFF Research Database (Denmark)

    Özcan, Oktay; Meyer, Knud Erik; Larsen, Poul Scheel

    2005-01-01

    A technique is described for measuring the mean velocity gradient (rate-of-displacement) tensor by using a conventional stereoscopic particle image velocimetry (SPIV) system. Planar measurement of the mean vorticity vector, rate-of-rotation and rate-of-strain tensors and the production of turbule...

  5. Measurement and Analysis of Rotational Energy of Nitrogen Molecular Beam by REMPI

    International Nuclear Information System (INIS)

    Mori, H.; Yamaguchi, H.; Kataoka, K.; Sugiyama, N.; Ide, K.; Niimi, T.

    2008-01-01

    Molecular beams are powerful tools for diagnoses of solid surfaces and gas-surface interaction tests. Unfortunately, there are very few reports about experimental analysis of internal energy distribution (e.g. rotational energy) of molecular beams of diatomic or polyatomic molecules, because measurement of internal energy distribution is very difficult. Spectroscopic measurement techniques based on resonantly enhanced multiphoton ionization (REMPI) is very powerful for measurement in highly rarefied gas flows. In this study, the REMPI method is applied to measurement of rotational energy distribution of nitrogen molecular beams. The REMPI spectrum of the molecular beam indicates the rotational temperature higher than the translational temperature of 7.2 K estimated by assuming isentropic flows. The O and P branches of the REMPI spectrum correspond to the rotational temperature of 30 K, but the S branch of the spectrum deviates from that at 30 K. It seems to be because the non-equilibrium rotational energy distribution of the molecular beam deviates from the Boltzmann distribution.

  6. New Measurements of Upsilon Spin Alignment at the Tevatron

    Directory of Open Access Journals (Sweden)

    Jones Matthew

    2012-06-01

    Full Text Available We describe a new analysis of γ(nS → μ+μ− decays collected in pp¯ $par p$ collisions with the CDF II detector at the Fermilab Tevatron. This analysis measures the angular distributions of the final state muons in the γ rest frame, providing new information about γ production polarization. We find the angular distributions to be nearly isotropic up to γ pT of 40 GeV/c, consistent with previous measurements by CDF, but inconsistent with results obtained by the D0 experiment. The results are compared with recent NLO calculations based on color-singlet matrix elements and non-relativistic QCD with color-octet matrix elements.

  7. Unique electron polarimeter analyzing power comparison and precision spin-based energy measurement

    International Nuclear Information System (INIS)

    Joseph Grames; Charles Sinclair; Joseph Mitchell; Eugene Chudakov; Howard Fenker; Arne Freyberger; Douglas Higinbotham; Poelker, B.; Michael Steigerwald; Michael Tiefenback; Christian Cavata; Stephanie Escoffier; Frederic Marie; Thierry Pussieux; Pascal Vernin; Samuel Danagoulian; Kahanawita Dharmawardane; Renee Fatemi; Kyungseon Joo; Markus Zeier; Viktor Gorbenko; Rakhsha Nasseripour; Brian Raue; Riad Suleiman; Benedikt Zihlmann

    2004-01-01

    Precision measurements of the relative analyzing powers of five electron beam polarimeters, based on Compton, Moller, and Mott scattering, have been performed using the CEBAF accelerator at the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory). A Wien filter in the 100 keV beamline of the injector was used to vary the electron spin orientation exiting the injector. High statistical precision measurements of the scattering asymmetry as a function of the spin orientation were made with each polarimeter. Since each polarimeter receives beam with the same magnitude of polarization, these asymmetry measurements permit a high statistical precision comparison of the relative analyzing powers of the five polarimeters. This is the first time a precise comparison of the analyzing powers of Compton, Moller, and Mott scattering polarimeters has been made. Statistically significant disagreements among the values of the beam polarization calculated from the asymmetry measurements made with each polarimeter reveal either errors in the values of the analyzing power, or failure to correctly include all systematic effects. The measurements reported here represent a first step toward understanding the systematic effects of these electron polarimeters. Such studies are necessary to realize high absolute accuracy (ca. 1%) electron polarization measurements, as required for some parity violation measurements planned at Jefferson Laboratory. Finally, a comparison of the value of the spin orientation exiting the injector that provides maximum longitudinal polarization in each experimental hall leads to an independent and very precise (better than 10-4) absolute measurement of the final electron beam energy

  8. Experimental determination of the spin-rotation coupling constant in the Cs129Xe and K129Xe molecules

    International Nuclear Information System (INIS)

    Wu, Z.; Happer, W.

    1984-01-01

    Since alkali-noble gas van der Waals molecules are involved in the spin transfer process, the physics can be naturally divided into two parts. One of them is to study the formation and break-up rates of the molecules, the chemical equilibrium constant, etc. The other aspect of this problem is to study how the individual angular momenta evolve during the lifetime of the molecule. The experiments described address the second aspect

  9. Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation.

    Directory of Open Access Journals (Sweden)

    Xiaoqiong Li

    Full Text Available Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR and a second rotation (SR stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC did not significantly differ between rotations, while understory vegetation (UC and soil organic matter (SOC stored less carbon in the SR (1.01 vs. 2.76 Mg.ha(-1 and 70.68 vs. 81.08 Mg. ha(-1, respectively and forest floor carbon (FFC conversely stored more (2.80 vs. 2.34 Mg. ha(-1. The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential.

  10. Measuring Mid- and Near-Field Rotational Ground Motions in Taiwan

    Science.gov (United States)

    Huang, B. S.; Liu, C. C.; Lin, C. R.; Wu, C. F.; Lee, W. H.

    2006-12-01

    Large rotational motions (about 200 micro-radians) excited by the 1999 Chi-Chi (Mw=7.6), Taiwan, earthquake were inferred from a dense accelerometer array 6 km from the northern end of the fault where large surface slips were observed (Huang, 2003). In December, 2000, C. C. Liu and B. S. Huang began measuring rotation motions using a PVC-5 transducer (0.2V/rad/sec) and a GyroChip sensor (1.43 V/rad/sec) at station HRLT near Hualien. However, no significant rotation motions were observed in the 5 years since, probably due to the low sensor sensitivity although many earthquakes occurred nearby. In July, 2004, Liu and Huang began measuring rotation motions using a far more sensitive triaxial sensor, R-1, made by eentec/PMD (50 V/rad/sec) at station HGSD near Cheng-Kung. At 18:50, September 26, 2005, an Mw=4.7 earthquake occurred 29 km south of station HGSD. The observed maximum rotation velocity for the EW, NS and Z component is 306, 499, and 1863 micro-rad/s, respectively. At 17:01, January 8, 2006, an Mw=4.6 earthquake occurred 36 km south of station HGSD. The observed maximum rotation velocity for the EW, NS and Z component is 98, 183, and 217 micro-rad/s, respectively. In both cases, the observed rotation waveforms (prominent frequency about 3 Hz) are far above the background noise (signal-to-noise ratio is usually greater than 100), and imply rotational motions of a few tens of micro- radians. However, the R-1 sensor has not been rigorously calibrated, and Liu and Huang are not sure of these measurements, which are orders of magnitude larger than a simple theoretical model by Bouchon and Aki (1982) would predict for these small earthquakes. To further investigate the question whether rotational ground motions are significant or not in the mid- and near- field of earthquakes, we are now planning a more careful experiment at two sites in Taiwan. Two R-1 and two RSB-20 (made by PMD) rotational velocity sensors are now being tested and calibrated by Robert Nigbor of

  11. Munition Mass Properties Measurement Procedures Using a Spin Balance Machine

    Science.gov (United States)

    2015-03-09

    climatic adjustments made. For example, the heating, ventilation, and air conditioning ( HVAC ) may need to be turned off to reduce air flow around the...machine’s mass properties computer is programmed to average moment readings at each of the quadrant positions (0°, 90°, 180° and 270°). The motor drive...2 I1 = MOI of Control Surface I2 = MOI of Machine Motor I3 = MOI of Fixture Tare Measurement Eq. 2 MOI = I2 + I3 = (KT2 )2

  12. Electron Paramagnetic Resonance Measurements of Reactive Oxygen Species by Cyclic Hydroxylamine Spin Probes.

    Science.gov (United States)

    Dikalov, Sergey I; Polienko, Yuliya F; Kirilyuk, Igor

    2017-11-17

    Oxidative stress contributes to numerous pathophysiological conditions such as development of cancer, neurodegenerative, and cardiovascular diseases. A variety of measurements of oxidative stress markers in biological systems have been developed; however, many of these methods are not specific, can produce artifacts, and do not directly detect the free radicals and reactive oxygen species (ROS) that cause oxidative stress. Electron paramagnetic resonance (EPR) is a unique tool that allows direct measurements of free radical species. Cyclic hydroxylamines are useful and convenient molecular probes that readily react with ROS to produce stable nitroxide radicals, which can be quantitatively measured by EPR. In this work, we critically review recent applications of various cyclic hydroxylamine spin probes in biology to study oxidative stress, their advantages, and the shortcomings. Recent Advances: In the past decade, a number of new cyclic hydroxylamine spin probes have been developed and their successful application for ROS measurement using EPR has been published. These new state-of-the-art methods provide improved selectivity and sensitivity for in vitro and in vivo studies. Although cyclic hydroxylamine spin probes EPR application has been previously described, there has been lack of translation of these new methods into biomedical research, limiting their widespread use. This work summarizes "best practice" in applications of cyclic hydroxylamine spin probes to assist with EPR studies of oxidative stress. Additional studies to advance hydroxylamine spin probes from the "basic science" to biomedical applications are needed and could lead to better understanding of pathological conditions associated with oxidative stress. Antioxid. Redox Signal. 00, 000-000.

  13. Decoherence dynamics of a single spin versus spin ensemble

    NARCIS (Netherlands)

    Dobrovitski, V.V.; Feiguin, A.E.; Awschalom, D.D.; Hanson, R.

    2008-01-01

    We study decoherence of central spins by a spin bath, focusing on the difference between measurement of a single central spin and measurement of a large number of central spins (as found in typical spin-resonance experiments). For a dilute spin bath, the single spin demonstrates Gaussian

  14. Spin dynamics and exchange interactions in CuO measured by neutron scattering

    Science.gov (United States)

    Jacobsen, H.; Gaw, S. M.; Princep, A. J.; Hamilton, E.; Tóth, S.; Ewings, R. A.; Enderle, M.; Wheeler, E. M. Hétroy; Prabhakaran, D.; Boothroyd, A. T.

    2018-04-01

    The magnetic properties of CuO encompass several contemporary themes in condensed-matter physics, including quantum magnetism, magnetic frustration, magnetically-induced ferroelectricity, and orbital currents. Here we report polarized and unpolarized neutron inelastic scattering measurements which provide a comprehensive map of the cooperative spin dynamics in the low-temperature antiferromagnetic (AFM) phase of CuO throughout much of the Brillouin zone. At high energies (E ≳100 meV ), the spectrum displays continuum features consistent with the des Cloizeax-Pearson dispersion for an ideal S =1/2 Heisenberg AFM chain. At lower energies, the spectrum becomes more three dimensional, and we find that a linear spin-wave model for a Heisenberg AFM provides a very good description of the data, allowing for an accurate determination of the relevant exchange constants in an effective spin Hamiltonian for CuO. In the high-temperature helicoidal phase, there are features in the measured low-energy spectrum that we could not reproduce with a spin-only model. We discuss how these might be associated with the magnetically-induced multiferroic behavior observed in this phase.

  15. Measurements of isocenter path characteristics of the gantry rotation axis with a smartphone application

    International Nuclear Information System (INIS)

    Schiefer, H.; Peters, S.; Plasswilm, L.; Ingulfsen, N.; Kluckert, J.

    2015-01-01

    Purpose: For stereotactic radiosurgery, the AAPM Report No. 54 [AAPM Task Group 42 (AAPM, 1995)] requires the overall stability of the isocenter (couch, gantry, and collimator) to be within a 1 mm radius. In reality, a rotating system has no rigid axis and thus no isocenter point which is fixed in space. As a consequence, the isocenter concept is reviewed here. It is the aim to develop a measurement method following the revised definitions. Methods: The mechanical isocenter is defined here by the point which rotates on the shortest path in the room coordinate system. The path is labeled as “isocenter path.” Its center of gravity is assumed to be the mechanical isocenter. Following this definition, an image-based and radiation-free measurement method was developed. Multiple marker pairs in a plane perpendicular to the assumed gantry rotation axis of a linear accelerator are imaged with a smartphone application from several rotation angles. Each marker pair represents an independent measuring system. The room coordinates of the isocenter path and the mechanical isocenter are calculated based on the marker coordinates. The presented measurement method is by this means strictly focused on the mechanical isocenter. Results: The measurement result is available virtually immediately following completion of measurement. When 12 independent measurement systems are evaluated, the standard deviations of the isocenter path points and mechanical isocenter coordinates are 0.02 and 0.002 mm, respectively. Conclusions: The measurement is highly accurate, time efficient, and simple to adapt. It is therefore suitable for regular checks of the mechanical isocenter characteristics of the gantry and collimator rotation axis. When the isocenter path is reproducible and its extent is in the range of the needed geometrical accuracy, it should be taken into account in the planning process. This is especially true for stereotactic treatments and radiosurgery

  16. A procedure for combining rotating-coil measurements of large-aperture accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Köster, Oliver, E-mail: oliver.koester@cern.ch; Fiscarelli, Lucio, E-mail: lucio.fiscarelli@cern.ch; Russenschuck, Stephan, E-mail: stephan.russenschuck@cern.ch

    2016-05-11

    The rotating search coil is a precise and widely used tool for measuring the magnetic field harmonics of accelerator magnets. This paper deals with combining several such multipole measurements, in order to cover magnet apertures largely exceeding the diameter of the available search coil. The method relies on the scaling laws for multipole coefficients and on the method of analytic continuation along zero-homotopic paths. By acquiring several measurements of the integrated magnetic flux density at different transverse positions within the bore of the accelerator magnet, the uncertainty on the field harmonics can be reduced at the expense of tight tolerances on the positioning. These positioning tolerances can be kept under control by mounting the rotating coil and its motor-drive unit on precision alignment stages. Therefore, the proposed technique is able to yield even more precise results for the higher-order field components than a dedicated rotating search coil of larger diameter. Moreover, the versatility of the measurement bench is enhanced by avoiding the construction of rotating search coils of different measurement radii.

  17. Measurements of the nuclear spin-spin relaxation times for commensurate {sup 3}He-Ne films adsorbed on hexagonal boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Parks, C; Sullivan, N S [Department of Physics, University of Florida, Gainesville, FL 32611 (United States); Stachowiak, P [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw (Poland)], E-mail: Sullivan@phys.ufl.edu

    2009-02-01

    Measurements of the {sup 3}He nuclear spin-spin relaxation time, T{sub 2}, have been carried out for commensurate layers of {sup 3}He-Ne mixtures adsorbed on hexagonal boron nitride for temperatures 0.2< T <10 K. A temperature independent relaxation is observed at low temperatures and is interpreted in terms of the effective exchange frequencies for {sup 3}He particle exchange on the surface. The results show a strong dependence on the fraction of neon in the adsorbed layer. This variation is discussed in terms of a multiple spin exchange model for {sup 3}He in a monolayer. The contributions to T{sub 2} from different components of the exchange, 2-spin exchange (J{sub 2}), 3-spin exchange (J{sub 3}), 4-spin exchange (J{sub 4}) and higher exchange permutations depend on the {sup 3}He coverage and thus permit the separation of the amplitudes of the different exchange rates, and in particular allow one to deduce the relative strengths of 2-atom and 3-atom exchange where other methods are sensitive only to the effective two-particle term J{sub eff} = J{sub 2} - 2J{sub 3}.

  18. Multipurpose Rotating Rake Arrays for Integrated Inlet and Fan Stage Performance Measurement

    Science.gov (United States)

    Wolter, John D.

    2017-01-01

    Low-pressure-ratio fan stage performance measurement requires precise measurement of conditions upstream and downstream of the fan stage. This presentation will discuss the rotating rake arrays used for the recent Boundary Layer Ingesting Inlet-Distortion-Tolerant Fan experiment in the NASA Glenn 8 by 6 foot wind tunnel. To achieve precise measurements, simulations of the rake sampling from pre-test CFD (Computerized Fluid Dynamics) solutions were used to optimize the number and locations of rake instruments.

  19. Measurement of the neutrino-spin correlation parameter B neutron decay using ultracold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Wilburn, Wesley S [Los Alamos National Laboratory

    2009-01-01

    We present a new approach to measuring the neutrino-spin correlation parameter B in neutron decay. The approach combines the technology of large-area ion-implanted silicon detectors being developed for the abBA experiment, with an ultracold neutron source to provide more precise neutron polarimetry. The technique detects both proton and electron from the neutron decay in coincidence. B is determined from an electron-energy-dependent measurement of the proton spin asymmetry. This approach will provide a statistical precision of 1 x 10-4 . The systematic precision is still being evaluated, but is expected to be below 1 x 10-3 , and could approach 1 x 10-4 . A measurement of B with this precision would place constraints on supersymmetric extensions to the Standard Model.

  20. Measurement of the $t\\bar{t}$ spin correlations and top quark polarization in dileptonic channel

    CERN Document Server

    Khatiwada, Ajeeta

    2017-01-01

    The degree of top polarization and strength of $t\\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\\bar{t}$ production is possible through various observables related to the angular distribution of decay leptons. A measurement of differential distribution provides a precision test of the standard model of particle physics and probes for deviations, which could be a sign of new physics. In particular, the phase space for the super-symmetric partner of the top quark can be constrained. Results from the Compact Muon Solenoid (CMS) collaboration for top quark polarization and spin correlation in the dileptonic channel are reviewed briefly in this proceeding. The measurements are obtained using 19.5 fb$^{-1}$ of data collected in pp collisions at the center-of-mass energy of 8 TeV.

  1. Measuring absolute spin polarization in dissolution-DNP by Spin PolarimetrY Magnetic Resonance (SPY-MR).

    Science.gov (United States)

    Vuichoud, Basile; Milani, Jonas; Chappuis, Quentin; Bornet, Aurélien; Bodenhausen, Geoffrey; Jannin, Sami

    2015-11-01

    Dynamic nuclear polarization at 1.2 K and 6.7 T allows one to achieve spin temperatures on the order of a few millikelvin, so that the high-temperature approximation (ΔEPolarimetrY Magnetic Resonance (SPY-MR), is illustrated for various pairs of (13)C spins (I, S) in acetate and pyruvate. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. A magneto-optically modulated CH3OH laser for Faraday rotation measurements in tokamaks

    International Nuclear Information System (INIS)

    Mansfield, D.K.; Johnson, L.C.

    1981-01-01

    Distortion-free intracavity polarization modulation of an optically pumped CH3OH laser is shown to be viable. The possible use of this modulation technique to make a multichannel Faraday rotation measurement on a tokamak device is discussed. In addition, the CdTe Faraday modulator employed in this study is shown to have an anomalously large Verdet constant

  3. Magneto-optically modulated CH/sub 3/OH laser For faraday rotation measurements in tokamaks

    International Nuclear Information System (INIS)

    Mansfield, D.K.; Johnson, L.C.

    1981-01-01

    Distortion-free intracavity polarization modulation of an optically pumped CH/sub 3/OH laser is shown to be viable. The possible use of this modulation technique to make a multichannel Faraday rotation measurement on a Tokamak device is discussed. In addition, the CdTe Faraday modulator employed in this study is shown to have an anomalously large Verdet constant. 12 refs

  4. Measurements of coronal Faraday rotation at 4.6 R ☉

    International Nuclear Information System (INIS)

    Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J.; Spangler, Steven R.

    2014-01-01

    Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of 5 R ☉ . We report on sensitive Very Large Array (VLA) full-polarization observations made in 2011 August, at 5.0 and 6.1 GHz (each with a bandwidth of 128 MHz) of the radio galaxy 3C 228 through the solar corona at heliocentric distances of 4.6-5.0 R ☉ . Observations at 5.0 GHz permit measurements deeper in the corona than previous VLA observations at 1.4 and 1.7 GHz. These Faraday rotation observations provide unique information on the magnetic field in this region of the corona. The measured Faraday rotation on this day was lower than our a priori expectations, but we have successfully modeled the measurement in terms of observed properties of the corona on the day of observation. Our data on 3C 228 provide two lines of sight (separated by 46'', 33,000 km in the corona). We detected three periods during which there appeared to be a difference in the Faraday rotation measure between these two closely spaced lines of sight. These measurements (termed differential Faraday rotation) yield an estimate of 2.6-4.1 GA for coronal currents. Our data also allow us to impose upper limits on rotation measure fluctuations caused by coronal waves; the observed upper limits were 3.3 and 6.4 rad m –2 along the two lines of sight. The implications of these results for Joule heating and wave heating are briefly discussed.

  5. Optical Transient-Grating Measurements of Spin Diffusion and Relaxation in a Two-Dimensional Electron Gas

    International Nuclear Information System (INIS)

    Weber, Christopher P.

    2005-01-01

    Spin diffusion in n-GaAs quantum wells, as measured by our optical transient-grating technique, is strongly suppressed relative to that of charge. Over a broad range of temperatures and dopings, the suppression of Ds relative to Dc agrees quantitatively with the prediction of ''spin Coulomb dra'' theory, which takes into account the exchange of spin in electron-electron collisions. Moreover, the spin-diffusion length, Ls, is a nearly constant 1 micrometer over the same range of T and n, despite Ds's varying by nearly two orders of magnitude. This constancy supports the D'yakonov-Perel'-Kachorovskii model of spin relaxation through interrupted precessional dephasing in the spin-orbit field

  6. Optical Transient-Grating Measurements of Spin Diffusion andRelaxation in a Two-Dimensional Electron Gas

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Christopher Phillip [Univ. of California, Berkeley, CA (United States)

    2005-01-01

    Spin diffusion in n-GaAs quantum wells, as measured by our optical transient-grating technique, is strongly suppressed relative to that of charge. Over a broad range of temperatures and dopings, the suppression of Ds relative to Dc agrees quantitatively with the prediction of ''spin Coulomb dra'' theory, which takes into account the exchange of spin in electron-electron collisions. Moreover, the spin-diffusion length, Ls, is a nearly constant 1 micrometer over the same range of T and n, despite Ds's varying by nearly two orders of magnitude. This constancy supports the D'yakonov-Perel'-Kachorovskii model of spin relaxation through interrupted precessional dephasing in the spin-orbit field.

  7. Spin Qubits in GaAs Heterostructures and Gating of InAs Nanowires for Lowtemperature Measurements

    DEFF Research Database (Denmark)

    Nissen, Peter Dahl

    of the contenders in the race to build a large-scale quantum computer, is such a component, and research aiming to build, manipulate and couple spin qubits is looking at many materials systems to nd one where the requirements for fast control and long coherence time can be combined with ecient coupling between...... from screening effects. We find that simple, alternating spin filling is not followed. Furthermore, measurement of the exchange splitting, J, indicate two magnetic field dependent transitions lifting spin blockade which is likewise inconsistent with the simplest model for spin filling. The effect...

  8. Methodological considerations of electron spin resonance spin trapping techniques for measuring reactive oxygen species generated from metal oxide nanomaterials.

    Science.gov (United States)

    Jeong, Min Sook; Yu, Kyeong-Nam; Chung, Hyun Hoon; Park, Soo Jin; Lee, Ah Young; Song, Mi Ryoung; Cho, Myung-Haing; Kim, Jun Sung

    2016-05-19

    Qualitative and quantitative analyses of reactive oxygen species (ROS) generated on the surfaces of nanomaterials are important for understanding their toxicity and toxic mechanisms, which are in turn beneficial for manufacturing more biocompatible nanomaterials in many industrial fields. Electron spin resonance (ESR) is a useful tool for detecting ROS formation. However, using this technique without first considering the physicochemical properties of nanomaterials and proper conditions of the spin trapping agent (such as incubation time) may lead to misinterpretation of the resulting data. In this report, we suggest methodological considerations for ESR as pertains to magnetism, sample preparation and proper incubation time with spin trapping agents. Based on our results, each spin trapping agent should be given the proper incubation time. For nanomaterials having magnetic properties, it is useful to remove these nanomaterials via centrifugation after reacting with spin trapping agents. Sonication for the purpose of sample dispersion and sample light exposure should be controlled during ESR in order to enhance the obtained ROS signal. This report will allow researchers to better design ESR spin trapping applications involving nanomaterials.

  9. Pure rotational Raman lidar for the measurement of vertical profiles of temperature in the lower atmosphere

    Science.gov (United States)

    Satyanarayana, M.; Radhakrishnan, S. R.; Presennakumar, B.; Murty, V. S.; Bindhu, R.

    2006-12-01

    The design and development of the new Raman lidar of the Space Physics Laboratory, Vikram Sarabhai Space Centre is presented here. This station is located at 8 degrees 33 minutes N, 77 degrees E in India. This lidar can monitor atmospheric temperature (using Pure Rotational Raman Spectrum), aerosol extinction coefficient, water vapor profile and clouds. Advantages of Pure Rotational Raman method over Vibrational Raman method are presented with the result obtained using Vibrational Raman lidar. Optical layout of the lidar system, PRRS method and aerosol extinction measurements are described briefly.

  10. Measurements of double-polarized compton scattering asymmetries and extraction of the proton spin polarizabilities.

    Science.gov (United States)

    Martel, P P; Miskimen, R; Aguar-Bartolome, P; Ahrens, J; Akondi, C S; Annand, J R M; Arends, H J; Barnes, W; Beck, R; Bernstein, A; Borisov, N; Braghieri, A; Briscoe, W J; Cherepnya, S; Collicott, C; Costanza, S; Denig, A; Dieterle, M; Downie, E J; Fil'kov, L V; Garni, S; Glazier, D I; Gradl, W; Gurevich, G; Hall Barrientos, P; Hamilton, D; Hornidge, D; Howdle, D; Huber, G M; Jude, T C; Kaeser, A; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Krusche, B; Lazarev, A; Lisin, V; Livingston, K; MacGregor, I J D; Mancell, J; Manley, D M; Meyer, W; Middleton, D G; Mushkarenkov, A; Nefkens, B M K; Neganov, A; Nikolaev, A; Oberle, M; Ortega Spina, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Polyansky, V; Prakhov, S; Rajabi, A; Reicherz, G; Rostomyan, T; Sarty, A; Schrauf, S; Schumann, S; Sikora, M H; Starostin, A; Steffen, O; Strakovsky, I I; Strub, T; Supek, I; Thiel, M; Tiator, L; Thomas, A; Unverzagt, M; Usov, Y; Watts, D P; Witthauer, L; Werthmüller, D; Wolfes, M

    2015-03-20

    The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields γ(E1E1)=-3.5±1.2, γ(M1M1)=3.16±0.85, γ(E1M2)=-0.7±1.2, and γ(M1E2)=1.99±0.29, in units of 10(-4)  fm(4).

  11. Polarization measurement of atomic hydrogen beam spin-exchanged with optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Ueno, Akira; Ogura, Kouichi; Wakuta, Yoshihisa; Kumabe, Isao

    1988-01-01

    The spin-exchange reaction between hydrogen atoms and optically oriented sodium atoms was used to produce a polarized atomic hydrogen beam. The electron-spin polarization of the atomic hydrogen beam, which underwent the spin-exchange reaction with the optically oriented sodium atoms, was measured. A beam polarization of -(8.0±0.6)% was obtained when the thickness and polarization of the sodium target were (5.78±0.23)x10 13 atoms/cm 2 and -(39.6±1.6)%, respectively. The value of the spin-exchange cross section in the forward scattering direction, whose scattering angle in the laboratory system was less than 1.0 0 , was obtained from the experimental results as Δσ ex =(3.39±0.34)x10 -15 cm 2 . This value is almost seven times larger than the theoretical value calculated from the Na-H potential. The potential was computed quantum mechanically in the space of the appropriate wave functions of the hydrogen and the sodium atoms. (orig./HSI)

  12. A measure of statistical complexity based on predictive information with application to finite spin systems

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, Samer A., E-mail: samer.abdallah@eecs.qmul.ac.uk [School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS (United Kingdom); Plumbley, Mark D., E-mail: mark.plumbley@eecs.qmul.ac.uk [School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS (United Kingdom)

    2012-01-09

    We propose the binding information as an information theoretic measure of complexity between multiple random variables, such as those found in the Ising or Potts models of interacting spins, and compare it with several previously proposed measures of statistical complexity, including excess entropy, Bialek et al.'s predictive information, and the multi-information. We discuss and prove some of the properties of binding information, particularly in relation to multi-information and entropy, and show that, in the case of binary random variables, the processes which maximise binding information are the ‘parity’ processes. The computation of binding information is demonstrated on Ising models of finite spin systems, showing that various upper and lower bounds are respected and also that there is a strong relationship between the introduction of high-order interactions and an increase of binding-information. Finally we discuss some of the implications this has for the use of the binding information as a measure of complexity. -- Highlights: ► We introduce ‘binding information’ as a entropic/statistical measure of complexity. ► Binding information (BI) is related to earlier notions of predictive information. ► We derive upper and lower bounds of BI relation to entropy and multi-information. ► Parity processes found to maximise BI in finite sets of binary random variables. ► Application to spin glasses shows highest BI obtained with high-order interactions.

  13. Rotational temperature measurement of NO gas using two-photon excitation spectrum

    Science.gov (United States)

    Ozaki, Tadao; Matsui, Yoshihiko; Ohsawa, Toshihiko

    1981-04-01

    The rotational temperature of nitric oxide gas has been measured by means of a single-beam two-photon excitation spectrum method using a pulsed continuously tunable dye laser. The nitric oxide gas was enclosed at about 40 Torr in a quartz cell which was put in an electric oven. The NO γ (0-0) band and R11+Q21 branches were used to obtain the two-photon excitation spectrum. The rotational temperatures were determined using the fact that molecules are distributed in the rotational levels according to the Boltzmann law. The temperature range was from room temperature to about 470 K. Observed temperatures were in good agreement with cell temperatures which were obtained by using a thermocouple.

  14. Temperature measurements on fast-rotating objects using a thermographic camera with an optomechanical image derotator

    Science.gov (United States)

    Altmann, Bettina; Pape, Christian; Reithmeier, Eduard

    2017-08-01

    Increasing requirements concerning the quality and lifetime of machine components in industrial and automotive applications require comprehensive investigations of the components in conditions close to the application. Irregularities in heating of mechanical parts reveal regions with increased loading of pressure, draft or friction. In the long run this leads to damage and total failure of the machine. Thermographic measurements of rotating objects, e.g., rolling bearings, brakes, and clutches provide an approach to investigate those defects. However, it is challenging to measure fast-rotating objects accurately. Currently one contact-free approach is performing stroboscopic measurements using an infrared sensor. The data acquisition is triggered so that the image is taken once per revolution. This leads to a huge loss of information on the majority of the movement and to motion blur. The objective of this research is showing the potential of using an optomechanical image derotator together with a thermographic camera. The derotator follows the rotation of the measurement object so that quasi-stationary thermal images during motion can be acquired by the infrared sensor. Unlike conventional derotators which use a glass prism to achieve this effect, the derotator within this work is equipped with a sophisticated reflector assembly. These reflectors are made of aluminum to transfer infrared radiation emitted by the rotating object. Because of the resulting stationary thermal image, the operation can be monitored continuously even for fast-rotating objects. The field of view can also be set to a small off-axis region of interest which then can be investigated with higher resolution or frame rate. To depict the potential of this approach, thermographic measurements on a rolling bearings in different operating states are presented.

  15. Spin-torque transistor

    NARCIS (Netherlands)

    Bauer, G.E.W.; Brataas, A.; Tserkovnyak, Y.; Van Wees, B.J.

    2003-01-01

    A magnetoelectronic thin-film transistor is proposed that can display negative differential resistance and gain. The working principle is the modulation of the soure–drain current in a spin valve by the magnetization of a third electrode, which is rotated by the spin-torque created by a control spin

  16. Measurements of spin-lattice relaxation time in mixed alkali halide crystals

    International Nuclear Information System (INIS)

    Tannus, A.

    1983-01-01

    Using magneto-optic techniques the ground state spin-lattice relaxation times (T1) of 'F' centers in mixed Alkali Halide cristals (KCl-KBr), was studied. A computer assisted system to optically measure short relaxation times (approx. = 1mS), was described. The technique is based on the measurement of the Magnetic Circular Dicroism (MCD) presented by F centers. The T1 magnetic field dependency at 2 K (up to 65 KGauss), was obtained as well as the MCD spectra for different relative concentration at the mixed matrices. The theory developed by Panepucci and Mollenauer for F centers spin-lattice relaxation in pure matrices was modified to explain the behaviour of T1 in mixed cristals. The Direct Process results (T approx. = 2.0 K) compared against that theory shows that the main relaxation mecanism, up to 25 KGauss, continues to be phonon modulation of the hiperfine iteraction between F electrons and surrounding nuclei. (Author) [pt

  17. Measuring Torque and Temperature in a Rotating Shaft Using Commercial SAW Sensors.

    Science.gov (United States)

    Silva, Diogo; Mendes, Joana C; Pereira, António B; Gégot, François; Alves, Luís N

    2017-07-02

    Real-time monitoring of torque in a rotating shaft is not easy to implement with technologies such as optic fiber sensors or strain gages. Surface acoustic wave (SAW) sensors are wireless and passive and can be used to monitor strain in moving parts. Commercial solutions (sensors, antennas and interrogation unit) can easily be purchased from some companies; however, they are not customized and may not meet the specificity of the measurements. In order to evaluate the adequacy of commercial off-the-shelf (COTS) solutions, temperature and strain sensors fabricated by SENSeOR (Besançon, France) were mounted on a load cell. The sensors were calibrated using a thermal chamber and a universal testing machine. The load cell was then assembled together with a steel shaft that rotated at different speeds inside an oven. The commercial antennas were replaced with an RF (radio frequency) coupler and the sensors were interrogated with the commercial interrogation unit. The influence of rotation in the accuracy on the measurements, as well as the adequacy of the sensors structure, was evaluated. It can be concluded that SAW sensors can be used to measure temperature or torque in a rotating environment; however, some customization of the components is required in order to overcome the limitations posed by COTS sensing solutions.

  18. Intratester and intertester reliability of goniometric measurement of passive lateral shoulder rotation.

    Science.gov (United States)

    MacDermid, J C; Chesworth, B M; Patterson, S; Roth, J H

    1999-01-01

    Measurement of lateral rotation range of motion (ROM) is frequently performed during shoulder evaluation. The purpose of this study was to determine the intratester and intertester reliability of goniometric measurement of passive lateral rotation ROM of the shoulder. Two experienced PTs performed the testing in a randomized block design. They were blinded to all clinical information and to their goniometric readings. Passive lateral rotation ROM of the shoulder was assessed in 34 patients with a variety of shoulder pathologies. Patients were placed in the supine position with the arm abducted approximately 20 degrees to 30 degrees. A standard goniometer, placed along the joint axis by the therapist, was red by an independent assistant. Intraclass correlation coefficients (ICCs) and their associated 95% confidence intervals were calculated. Intratherapist ICCs (0.88 and 0.93) and intertherapist ICCs (0.85 and 0.80) were high. These findings suggest that reliable measures of passive lateral rotation ROM of the shoulder can be obtained from patients with shoulder pathology using standard goniometry and by placing the patient in a supine position.

  19. Quantum spin quadrumer

    Science.gov (United States)

    Khatua, Subhankar; Shankar, R.; Ganesh, R.

    2018-02-01

    A fundamental motif in frustrated magnetism is the fully mutually coupled cluster of N spins, with each spin coupled to every other spin. Clusters with N =2 and 3 have been extensively studied as building blocks of square and triangular lattice antiferromagnets. In both cases, large-S semiclassical descriptions have been fruitfully constructed, providing insights into the physics of macroscopic magnetic systems. Here, we develop a semiclassical theory for the N =4 cluster. This problem has rich mathematical structure with a ground-state space that has nontrivial topology. We show that ground states are appropriately parametrized by a unit vector order parameter and a rotation matrix. Remarkably, in the low-energy description, the physics of the cluster reduces to that of an emergent free spin-S spin and a rigid rotor. This successfully explains the spectrum of the quadrumer and its associated degeneracies. However, this mapping does not hold in the vicinity of collinear ground states due to a subtle effect that arises from the nonmanifold nature of the ground-state space. We demonstrate this by an analysis of soft fluctuations, showing that collinear states have a larger number of soft modes. Nevertheless, as these singularities only occur on a subset of measure zero, the mapping to a spin and a rotor provides a good description of the quadrumer. We interpret thermodynamic properties of the quadrumer that are accessible in molecular magnets, in terms of the rotor and spin degrees of freedom. Our study paves the way for field theoretic descriptions of systems such as pyrochlore magnets.

  20. Electronic density measurement in the TB R-1 tokamak using Faraday rotation

    International Nuclear Information System (INIS)

    Elizondo, Juan Iraburu

    1996-01-01

    In this work, the experimental results of electronic density measurements in the TBR-1 tokamak, obtained by Faraday rotation of a microwave beam, are presented, The beam (65 GHz, 500 MW) is generated by a Klystron and crosses the plasma in the horizontal plane. The density values obtained are in agreement with the measurements of a conventional microwave interferometer. As a result of numerical simulations and measurements, it can be concluded that it would be advisable the use of lower wavelengths, to minimize the beam refraction when it crosses the plasma. The results show the feasibility of the Faraday rotation method for density measurement, in the first experiment performed in a tokamak, for the geometry considered. (author)

  1. Measurement of the transverse spin correlation in $Z \\to \\tau^+\\tau^-$ decays

    CERN Document Server

    Abreu, P; Adye, T; Ajinenko, I; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andersson, P; Andreazza, A; Antilogus, P; Apel, W D; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbi, M S; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Bärring, O; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bizouard, M A; Bloch, D; Blume, M; Bonesini, M; Bonivento, W; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozovic, I; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Djannati, A; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Durand, J D; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Feindt, Michael; Ferrari, P; Ferrer, A; Fichet, S; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gokieli, R; Golob, B; Gonçalves, P; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Green, C; Grefrath, A; Gris, P; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Hilke, Hans Jürgen; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Knoblauch, D; Köne, B; Kokkinias, P; Konoplyannikov, A K; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Libby, J; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Mahon, J R; Maio, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Myagkov, A; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Münich, K; Mulders, M; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Nikolenko, M; Niss, P; Nomerotski, A; Normand, Ainsley; Novák, M; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Pain, R; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Podobnik, T; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sahr, O; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Serbelloni, L; Shellard, R C; Siegrist, P; Silvestre, R; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Solovyanov, O; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stapnes, Steinar; Stavitski, I; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tegenfeldt, F; Terranova, F; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Wlodek, T; Yi, J; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zontar, D; Zucchelli, G C; Zumerle, G

    1997-01-01

    The measurement of the correlation between the transverse spin components of $\\tau^+\\tau^-$ pairs collected during 1992 to 1994 with the DELPHI detector at LEP1 is presented. A value \\begin{center} $C_{TT}$~=~0.87~$\\pm$~0.20~(stat.)~$^{+~0.10}_{-~0.12}$~(syst.) \\end{center} was obtained for the correlation parameter, in agreement with the St1AU LYi,

  2. On measuring the UNK SC-dipole bending strength with rotating pick-up coil

    International Nuclear Information System (INIS)

    Smirnov, N.L.; Tikhov, A.V.

    1993-01-01

    The experience in measuring the SC-dipole bending strength with the spotting method shown this measurement to be the most complicated and expensive. A convenient and simple method of rotating pick-up coil, which can not provide the required accuracy, may be used for this measurement combined with NMR measurements in the dipole central part. The physical ground and description of the method are given in the paper. The analysis of the errors and measurement results of the SPDMI SC-dipoles are presented. 9 refs..; 7 figs

  3. Measurement of proton and nitrogen polarization in ammonia and a test of equal spin temperature

    CERN Document Server

    Adeva, B; Arvidson, A; Badelek, B; Baum, G; Berglund, P; Betev, L; De Botton, N R; Bradamante, Franco; Bradtke, C; Bravar, A; Bültmann, S; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Dreshpande, A; Dhawan, S K; Dulya, C M; Dutz, H; Eichblatt, S; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gehring, R; Gilly, H; Giorgi, M A; Görtz, S; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; Harmsen, J; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Ketel, T; Kiryluk, J; Kiselev, Yu F; Kok, E; Krämer, Dietrich; Kröger, W; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; Magnon, A; Mallot, G K; Martin, A; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Nassalski, J P; Niinikoski, T O; Oberski, J; Ogawa, A; Parks, D P; Pereira da Costa, H D; Perrot-Kunne, F; Peshekhonov, V D; Pinsky, L; Platchkov, S K; Pló, M; Plückthun, M; Polec, J; Pose, D; Postma, H; Pretz, J; Puntaferro, R; Rädel, G; Reicherz, G; Rijllart, A; Rodríguez, M; Rondio, Ewa; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Tessarotto, F; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K

    1998-01-01

    The 1996 data taking of the SMC experiment used polarized protons to measure the spin dependent structure function $g_1$ of the proton. Three liters of solid granular ammonia were irradiated at the Bonn electron linac in order to create the paramagnetic radicals which are needed for polarizing the protons. Proton polarizations of $\\pm(90\\pm2.5)\\,\\%$ were routinely reached. An analysis based on a theoretical line-shape for spin-1 systems with large quadrupolar broadening was developed which allowed the nitrogen polarization in the ammonia to be determined with a 10\\,\\% relative error. The measured quadrupolar coupling constant of $^{14}$N agrees well with earlier extrapolated values. The polarization of the nitrogen nuclei was measured as a function of the proton polarization in order to provide a test of the equal spin temperature (EST) hypothesis. It was found to be closely valid under the dynamic nuclear polarization conditions with which the protons are polarized. Large deviations from EST could be induced...

  4. Misalignment calibration of geomagnetic vector measurement system using parallelepiped frame rotation method

    International Nuclear Information System (INIS)

    Pang, Hongfeng; Zhu, XueJun; Pan, Mengchun; Zhang, Qi; Wan, Chengbiao; Luo, Shitu; Chen, Dixiang; Chen, Jinfei; Li, Ji; Lv, Yunxiao

    2016-01-01

    Misalignment error is one key factor influencing the measurement accuracy of geomagnetic vector measurement system, which should be calibrated with the difficulties that sensors measure different physical information and coordinates are invisible. A new misalignment calibration method by rotating a parallelepiped frame is proposed. Simulation and experiment result show the effectiveness of calibration method. The experimental system mainly contains DM-050 three-axis fluxgate magnetometer, INS (inertia navigation system), aluminium parallelepiped frame, aluminium plane base. Misalignment angles are calculated by measured data of magnetometer and INS after rotating the aluminium parallelepiped frame on aluminium plane base. After calibration, RMS error of geomagnetic north, vertical and east are reduced from 349.441 nT, 392.530 nT and 562.316 nT to 40.130 nT, 91.586 nT and 141.989 nT respectively. - Highlights: • A new misalignment calibration method by rotating a parallelepiped frame is proposed. • It does not need to know sensor attitude information or local dip angle. • The calibration system attitude change angle is not strictly required. • It can be widely used when sensors measure different physical information. • Geomagnetic vector measurement error is reduced evidently.

  5. Misalignment calibration of geomagnetic vector measurement system using parallelepiped frame rotation method

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Hongfeng [Academy of Equipment, Beijing 101416 (China); College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073 (China); Zhu, XueJun, E-mail: zhuxuejun1990@126.com [College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073 (China); Pan, Mengchun; Zhang, Qi; Wan, Chengbiao; Luo, Shitu; Chen, Dixiang; Chen, Jinfei; Li, Ji; Lv, Yunxiao [College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073 (China)

    2016-12-01

    Misalignment error is one key factor influencing the measurement accuracy of geomagnetic vector measurement system, which should be calibrated with the difficulties that sensors measure different physical information and coordinates are invisible. A new misalignment calibration method by rotating a parallelepiped frame is proposed. Simulation and experiment result show the effectiveness of calibration method. The experimental system mainly contains DM-050 three-axis fluxgate magnetometer, INS (inertia navigation system), aluminium parallelepiped frame, aluminium plane base. Misalignment angles are calculated by measured data of magnetometer and INS after rotating the aluminium parallelepiped frame on aluminium plane base. After calibration, RMS error of geomagnetic north, vertical and east are reduced from 349.441 nT, 392.530 nT and 562.316 nT to 40.130 nT, 91.586 nT and 141.989 nT respectively. - Highlights: • A new misalignment calibration method by rotating a parallelepiped frame is proposed. • It does not need to know sensor attitude information or local dip angle. • The calibration system attitude change angle is not strictly required. • It can be widely used when sensors measure different physical information. • Geomagnetic vector measurement error is reduced evidently.

  6. Spin noise spectroscopy of ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Hauke; Huebner, Jens; Oestreich, Michael [Institute for Solid State Physics, Gottfried Wilhelm Leibniz University Hannover (Germany); Marie, Xavier; Balocchi, Andrea [INSA-CNRS-UPS, LPCNO, Universite de Toulouse (France)

    2010-07-01

    ZnO is a promising material for optical spintronics showing long electron spin lifetimes due to the large band gap and low amount of nuclear spin isotopes. Here, we use spin noise spectroscopy to access the electron spin dynamics of this material in thermal equilibrium while avoiding carrier heating and excitation of electron hole pairs. A linear polarized laser beam (E{sub UV-Laser}=3.32 eV) close to the direct band gap of ZnO (E{sub D}{sup 0}{sub X}=3.36 eV) is used to detect the spin dynamics of neutral donors in ZnO with off-resonant, non-demolition Faraday rotation. The stochastic oriented electron spins induce polarization fluctuations of the transmitted laser beam. The fluctuation strength of N non-interacting, paramagnetic spins follow the Poisson statistics and generate measurable noise {proportional_to}{radical}(N) spins. These fluctuations are measured via a polarization bridge in the radio frequency regime and Fourier transformed in real-time. A magnetic field B is applied in Voigt-geometry and modulates the noise signal with the Larmor frequency of the electron spins {omega}{sub L}=g{mu}{sub B}B/{Dirac_h}. From the recorded noise spectra we can extract the electron g-factor, spin lifetimes, and densities.

  7. A Precision Measurement of the Neutron Spin Structure Functions Using a Polarized HE-3 Target

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T

    2003-11-05

    This thesis describes a precision measurement of the neutron spin dependent structure function, g{sub 1}{sup n}(x). The measurement was made by the E154 collaboration at SLAC using a longitudinally polarized, 48.3 GeV electron beam, and a {sup 3}He target polarized by spin exchange with optically pumped rubidium. A target polarization as high as 50% was achieved. The elements of the experiment which pertain to the polarized {sup 3}He target will be described in detail in this thesis. To achieve a precision measurement, it has been necessary to minimize the systematic error from the uncertainty in the target parameters. All of the parameters of the target have been carefully measured, and the most important parameters of the target have been measured using multiple techniques. The polarization of the target was measured using nuclear magnetic resonance techniques, and has been calibrated using both proton NMR and by measuring the shift of the Rb Zeeman resonance frequency due to the {sup 3}He polarization. The fraction of events which originated in the {sup 3}He, as measured by the spectrometers, has been determined using a physical model of the target and the spectrometers. It was also measured during the experiment using a variable pressure {sup 3}He reference cell in place of the polarized {sup 3}He target. The spin dependent structure function g{sub 1}{sup n}(z) was measured in the Bjorken x range of 0.014 < x < 0.7 with an average Q{sup 2} of 5 (GeV/c){sup 2}. One of the primary motivations for this experiment was to test the Bjorken sum rule. Because the experiment had smaller statistical errors and a broader kinematic coverage than previous experiments, the behavior of the spin structure function g{sub 1}{sup n}(x) could be studied in detail at low values of the Bjorken scaling variable x. It was found that g{sub 1}{sup n}(x) has a strongly divergent behavior at low values of x, calling into question the methods commonly used to extrapolate the value of g

  8. Twin Rotating Coils for Cold Magnetic Measurements of 15 m Long LHC Dipoles

    CERN Document Server

    Billan, J; Buzio, M; D'Angelo, G; Deferne, G; Dunkel, O; Legrand, P; Rijllart, A; Siemko, A; Sievers, P; Schloss, S; Walckiers, L

    2000-01-01

    We describe here a new harmonic coil system for the field measurement of the superconducting, twin aperture LHC dipoles and the associated corrector magnets. Besides field measurements the system can be used as an antenna to localize the quench origin. The main component is a 16 m long rotating shaft, made up of 13 ceramic segments, each carrying two tangential coils plus a central radial coil, all working in parallel. The segments are connected with flexible Ti-alloy bellows, allowing the piecewise straight shaft to follow the curvature of the dipole while maintaining high torsional rigidity. At each interconnection the structure is supported by rollers and ball bearings, necessary for the axial movement for installation and for the rotation of the coil during measurement. Two such shafts are simultaneously driven by a twin-rotating unit, thus measuring both apertures of a dipole at the same time. This arrangement allows very short measurement times (typically 10 s) and is essential to perform cold magnetic ...

  9. Cross-sectional and longitudinal construct validity of two rotator cuff disease-specific outcome measures

    Directory of Open Access Journals (Sweden)

    van Osnabrugge Varda

    2006-03-01

    Full Text Available Abstract Background Disease-specific Quality Of Life (QOL measures are devised to assess the impact of a specific disease across a spectrum of important domains of life. The purpose of this study was to examine the cross-sectional and longitudinal construct validity (sensitivity to change of two rotator cuff disease-specific measures, the Rotator Cuff-Quality Of Life (RC-QOL and the Western Ontario Rotator Cuff (WORC index, in relation to one another and to other joint and limb specific measures in the same population of the patients suffering from rotator cuff pathology. Methods Participants enrolled were consecutive patients who received physical therapy for management of impingement syndrome or received treatment following rotator cuff repair, acromioplasty or decompression surgeries. All subjects received physical therapy treatment and completed four outcome measures at 3 single points (initial, interim, and final. Cross-sectional convergent validity was assessed at each of the 3 time-points by correlating the WORC and RC-QOL's scores to each other and to two alternative scales; a joint-specific scale, the American Shoulder and Elbow Surgeons (ASES standardized shoulder assessment form and a limb-specific measure, the Upper Extremity Functional Index (UEFI. Non-parametric statistics (Spearman's rho and Wilcoxon-Mann-Whitney tests examined the construct validity. The standardized response mean (SRM was used to examine sensitivity to change. Results Forty-one participants entered the study and their scores were compared at 3 cross sectional single points. The correlation coefficients among the 4 measures varied from 0.60 to 0.91. Correlation between corresponding domains of the WORC and RC-QOL varied from 0.45 to 0.85. The known group validity was not significantly different among individual sub-scores and total scores. The final SRMs were (1.42, (1.43, (1.44, and (1.54 for the ASES, RCQOL, WORC, and UEFI respectively. Conclusion The WORC and

  10. Magnetorheology of hybrid colloids measured by spin coating and classical rheometry

    Science.gov (United States)

    Muhammad Aslam, Raheema; Shahrivar, Keshwad; Álvarez-Manzaneda, Juan De Vicente; González-Viñas, Wenceslao

    Hybrid colloids composed of micron-sized ferromagnetic and diamagnetic particles constitute a promising category of magnetorheological fluids with enhanced field-induced apparent yield stress. However, the physical mechanism explaining this stress enhancement is currently lacking. For the first time, we measure and compare the magnetic field-dependent viscosity of hybrid diluted colloids using spin-coating and magnetorheometry. In the former technique, a magnetic field is applied during the spin coating of the colloidal suspension involving evaporation of the solvent. The viscosity of the colloidal suspension at applied field can be derived from the surface coverage of the dry spin-coated deposits and from the viscosity of the colloid at zero field. In the latter, its viscosity is measured with a torsional parallel plate magnetorheometer under uniaxial magnetic fields aligned in the gradient direction of a steady shearing flow. The experimental results under different conditions and the effect of each component on the magnetorheological properties of the resulting colloid will be discussed. This work is partly supported by the Spanish MINECO (FIS201454101-P).

  11. Spin measurements for 147Sm+n resonances: Further evidence for nonstatistical effects

    International Nuclear Information System (INIS)

    Koehler, P. E.; Ullmann, J. L.; Bredeweg, T. A.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Vieira, D. J.; Wouters, J. M.

    2007-01-01

    We have determined the spins J of resonances in the 147 Sm(n,γ) reaction by measuring multiplicities of γ-ray cascades following neutron capture. Using this technique, we were able to determine J values for all but 14 of the 141 known resonances below E n =1 keV, including 41 firm J assignments for resonances whose spins previously were either unknown or tentative. These new spin assignments, together with previously determined resonance parameters, allowed us to extract level spacings (D 0,3 =11.76±0.93 and D 0,4 =11.21±0.85 eV) and neutron strength functions (10 4 S 0,3 =4.70±0.91 and 10 4 S 0,4 =4.93±0.92) for J=3 and 4 resonances, respectively. Furthermore, cumulative numbers of resonances and cumulative reduced neutron widths as functions of resonance energy indicate that very few resonances of either spin have been missed below E n =700 eV. This conclusion is strengthened by the facts that, over this energy range, Wigner distributions calculated using these D 0 values agree with the measured nearest-neighbor level spacings to within the experimental uncertainties, and that the Δ 3 values calculated from the data also agree with the expected values. Because a nonstatistical effect recently was reported near E n =350 eV from an analysis of 147 Sm(n,α) data, we divided the data into two regions; 0 n n n 0 distribution for resonances below 350 eV is consistent with the expected Porter-Thomas distribution. However, we found that Γ n 0 data in the 350 n 2 distribution having ν≥2 We discuss possible explanations for these observed nonstatistical effects and their possible relation to similar effects previously observed in other nuclides

  12. Combining rotating-coil measurements of large-aperture accelerator magnets

    CERN Document Server

    AUTHOR|(CDS)2089510

    2016-10-05

    The rotating coil is a widely used tool to measure the magnetic field and the field errors in accelerator magnets. The coil has a length that exceeds the entire magnetic field along the longitudinal dimension of the magnet and gives therefore a two-dimensional representation of the integrated field. Having a very good precision, the rotating coil lacks in versatility. The fixed dimensions make it impractical and inapplicable in situations, when the radial coil dimension is much smaller than the aperture or when the aperture is only little covered by the coil. That being the case for rectangular apertures with large aspect ratio, where a basic measurement by the rotating coil describes the field only in a small area of the magnet. A combination of several measurements at different positions is the topic of this work. Very important for a combination is the error distribution on the measured field harmonics. To preserve the good precision of the higher-order harmonics, the combination must not rely on the main ...

  13. Fault Diagnosis for Rotating Machinery Using Vibration Measurement Deep Statistical Feature Learning.

    Science.gov (United States)

    Li, Chuan; Sánchez, René-Vinicio; Zurita, Grover; Cerrada, Mariela; Cabrera, Diego

    2016-06-17

    Fault diagnosis is important for the maintenance of rotating machinery. The detection of faults and fault patterns is a challenging part of machinery fault diagnosis. To tackle this problem, a model for deep statistical feature learning from vibration measurements of rotating machinery is presented in this paper. Vibration sensor signals collected from rotating mechanical systems are represented in the time, frequency, and time-frequency domains, each of which is then used to produce a statistical feature set. For learning statistical features, real-value Gaussian-Bernoulli restricted Boltzmann machines (GRBMs) are stacked to develop a Gaussian-Bernoulli deep Boltzmann machine (GDBM). The suggested approach is applied as a deep statistical feature learning tool for both gearbox and bearing systems. The fault classification performances in experiments using this approach are 95.17% for the gearbox, and 91.75% for the bearing system. The proposed approach is compared to such standard methods as a support vector machine, GRBM and a combination model. In experiments, the best fault classification rate was detected using the proposed model. The results show that deep learning with statistical feature extraction has an essential improvement potential for diagnosing rotating machinery faults.

  14. Quantum non demolition measurement of a single nuclear spin in a room temperature solid

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Phillip; Beck, Johannes; Steiner, Matthias; Rathgen, Helmut; Rempp, Florian; Zarrabi, Navid; Dolde, Florian; Jelezko, Fedor; Wrachtrup, Joerg [Universitaet Stuttgart (Germany); Hemmer, Philip [A and M University, Texas (United States)

    2010-07-01

    The measurement process and its interpretation are in the focus of quantum mechanics since its early days. Today's ability to isolate single quantum objects allows experimental demonstration of former ''gedankenexperiments'' like measurement induced quantum state collaps. Rapidly growing quantum technologies explore fundamental aspects of measurements in quantum computing, however for solid state systems such experiments require operation at very low temperatures. Here we show that projective quantum measurement can be performed on a single nuclear spin in diamond under ambient conditions. Using quantum non demolition (QND) readout we are able to detect quantum jumps and the quantum Zeno effect emphasising the addressability of fundamental questions of quantum mechanics in solids. Single shot measurements with fidelities exceeding 0.9 enable efficient state initialization, quantum error correction and entanglement pumping that is crucial for quantum information processing including measurement based schemes and distributed quantum networks.

  15. A remark on the infinite-volume Gibbs measures of spin glasses

    Science.gov (United States)

    Arguin, Louis-Pierre

    2008-12-01

    In this note, we point out that infinite-volume Gibbs measures of spin glass models on the hypercube can be identified as random probability measures on the unit ball of a Hilbert space. This simple observation follows from a result of Dovbysh and Sudakov on weakly exchangeable random matrices. Limiting Gibbs measures can then be studied as single well-defined objects. This approach naturally extends the space of random overlap structures as defined by Aizenman et al. We discuss the Ruelle probability cascades and the stochastic stability within this framework. As an application, we use an idea of Parisi and Talagrand to prove that if a sequence of finite-volume Gibbs measures satisfies the Ghirlanda-Guerra identities, then the infinite-volume measure must be singular as a measure on a Hilbert space.

  16. Digital Integrator for Fast Accurate Measurement of Magnetic Flux by Rotating Coils

    CERN Document Server

    Arpaia, P.; Spiezia, G.

    2007-01-01

    A fast digital integrator (FDI) with dynamic accuracy and a trigger frequency higher than those of a portable digital integrator (PDI), which is a state-of-the-art instrument for magnetic measurements based on rotating coils, was developed for analyzing superconducting magnets in particle accelerators. Results of static and dynamic metrological characterization show how the FDI prototype is already capable of overcoming the dynamic performance of PDI as well as covering operating regions that used to be inaccessible

  17. Electric fields in accelerating conductors: measurement of the EMF in rotationally accelerating coils

    Energy Technology Data Exchange (ETDEWEB)

    Moorhead, G.F.; Opat, G.I.

    1996-06-06

    The acceleration of an electric conductor is predicted to produce an electric filed proportional to m/q where `m`is the free mass and `q` the charge of the carriers of the electric current. In certain configurations this leads to a measurable electromagnetic field (EMF). In this paper is reported a measurement of the EMF induced by rotationally accelerating coils of aluminium and copper wire. The measured EMFs are found to agree with the theoretical predictions to within the error estimates. 23 refs., 1 tab., 4 figs.

  18. VizieR Online Data Catalog: Pulsar rotation measures (Han+, 2018)

    Science.gov (United States)

    Han, J. L.; Manchester, R. N.; van Straten, W.; Demorest, P.

    2018-03-01

    The Parkes 64m observations were made in seven sessions between 2006 August and 2008 February. All observations were in the 20cm band. The Green Bank 100m telescopes (GBT) observations were made in 2007 November using the 800MHz prime focus receiver. The Green Bank Astronomy Signal Processor pulsar observing system was used with a central frequency of 774MHz and a bandwidth of 96MHz. We have measured rotation measures for 477 pulsars, of which 441 are either new or improved over previous measurements. (3 data files).

  19. Irradiation of an Accretion Disc by a Jet: General Properties and Implications for Spin Measurements of Black Holes

    Science.gov (United States)

    T.Dauser; Garcia, J.; Wilms, J.; Boeck, M.; Brenneman, L. W.; Falanga, M.; Fukumura, Keigo; Reynolds, C. S.

    2013-01-01

    X-ray irradiation of the accretion disc leads to strong reflection features, which are then broadened and distorted by relativistic effects. We present a detailed, general relativistic approach to model this irradiation for different geometries of the primary X-ray source. These geometries include the standard point source on the rotational axis as well as more jet-like sources, which are radially elongated and accelerating. Incorporating this code in the RELLINE model for relativistic line emission, the line shape for any configuration can be predicted. We study how different irradiation geometries affect the determination of the spin of the black hole. Broad emission lines are produced only for compact irradiating sources situated close to the black hole. This is the only case where the black hole spin can be unambiguously determined. In all other cases the line shape is narrower, which could either be explained by a low spin or an elongated source. We conclude that for those cases and independent of the quality of the data, no unique solution for the spin exists and therefore only a lower limit of the spin value can be given

  20. Units of rotational information

    Science.gov (United States)

    Yang, Yuxiang; Chiribella, Giulio; Hu, Qinheping

    2017-12-01

    Entanglement in angular momentum degrees of freedom is a precious resource for quantum metrology and control. Here we study the conversions of this resource, focusing on Bell pairs of spin-J particles, where one particle is used to probe unknown rotations and the other particle is used as reference. When a large number of pairs are given, we show that every rotated spin-J Bell state can be reversibly converted into an equivalent number of rotated spin one-half Bell states, at a rate determined by the quantum Fisher information. This result provides the foundation for the definition of an elementary unit of information about rotations in space, which we call the Cartesian refbit. In the finite copy scenario, we design machines that approximately break down Bell states of higher spins into Cartesian refbits, as well as machines that approximately implement the inverse process. In addition, we establish a quantitative link between the conversion of Bell states and the simulation of unitary gates, showing that the fidelity of probabilistic state conversion provides upper and lower bounds on the fidelity of deterministic gate simulation. The result holds not only for rotation gates, but also to all sets of gates that form finite-dimensional representations of compact groups. For rotation gates, we show how rotations on a system of given spin can simulate rotations on a system of different spin.

  1. Corrections to nucleon spin structure asymmetries measured on nuclear polarized targets

    International Nuclear Information System (INIS)

    Rondon, O.A.

    1999-01-01

    The nucleon spin structure functions have been extracted from measurements of asymmetries in deep inelastic scattering of polarized leptons on polarized nuclei. The polarized nuclei present in practical targets: H, 2 H, 3 He, 14 N, 15 N, 6 Li, and 7 Li, are, with the exception of hydrogen, systems of bound nucleons, some of which can attain significant degrees of alignment. All the aligned nucleons contribute to the asymmetries. The contributions of each nuclear species to the asymmetry have to be carefully determined, before a reliable value for the net nucleon asymmetry is obtained. For this purpose, the spin component of the nuclear angular momentum for every nuclear state and the probability of each state have to be known with sufficient accuracy. In this paper I discuss the basic corrections used to estimate the contributions of the different nuclei, with emphasis on the A=6 and 7 Li isotopes present in the Li 2 H polarized target used during SLAC Experiment 155 to study the deuteron spin structure. copyright 1999 The American Physical Society

  2. Measurement of the spin-dependent structure-functions of the proton and the deuteron

    CERN Multimedia

    2002-01-01

    % NA47 %title \\\\ \\\\The physics motivation of the experiments of the Spin Muon Collaboration is to better understand how the nucleon spin is built-up by its partons and to test the fundamental Bjorken sum rule. \\\\ \\\\The spin-dependent structure functions $g _{1}(x)$ of the proton and the deuteron are determined from the measured cross section asymmetries for deep inelastic scattering of longitudinally polarized muons from longitudinally polarized nucleons. The experiment is similar to the NA2 one of the European Muon Collaboration in which the violation of the Ellis-Jaffe sum rule for the proton was found. \\\\ \\\\The apparatus is the upgraded forward spectrometer which was used originally by the European and New Muon Collaborations. To minimize the systematic uncertainties the target contains two oppositely polarized cells, which were exposed to the muon beam simultaneously. For the experiments in 1991 and 1992 the original EMC polarized target was reinstalled. In 1993 a new polarized target was put into operati...

  3. The E142 SLAC experiment: measurement of the neutron gn1(x) spin structure function

    International Nuclear Information System (INIS)

    Roblin, Y.

    1995-01-01

    This thesis describes the E142 experiment which has been carried out at the Stanford Linear Accelerator (SLAC), USA, from October to December 1992. This experiment of polarized inelastic scattering of a 22.6 GeV electron beam on a polarized helium 3 target has allowed the first measurement of the neutron g n 1 (x) spin structure function. The knowledge of this structure function gives informations on the nucleon spin structure. On the other hand, the g n 1 (x) structure function integral value on the 0 2 mean value of 2 GeV 2 after some extrapolations. This value is at about two standard deviations away from the theoretical predictions of the Ellis-Jaffe rule. Thanks to the existing experimental results for the proton (E143 experiment), the Bjorken sum rule has been precisely tested and is perfectly compatible with the theoretical value. The results have allowed to estimate the nucleon spin fraction carried by the quarks. (J.S.). 86 refs., 58 figs., 13 tabs

  4. Measurement of the spin-dependent structure-functions of the proton and the deuteron

    CERN Multimedia

    2002-01-01

    % NA47 %title \\\\ \\\\The physics motivation of the experiments of the Spin Muon Collaboration is to better understand how the nucleon spin is built-up by its partons and to test the fundamental Bjorken sum rule. \\\\ \\\\The spin-dependent stucture functions g$ _{1} $(x) of the proton and the deuteron are determined from the measured cross section asymmetries for deep inelastic scattering of longitudinally polarized muons from longitudinally polarized nucleons. The experiment is similar to the NA2 one of the European Muon Collaboration in which the violation of the Ellis-Jaffe sum rule for the proton was found. \\\\ \\\\The apparatus is the upgraded forward spectrometer which was used originally by the European and New Muon Collaborations. To minimize the systematic uncertainties the target contains two oppositely polarized cells, which were exposed to the muon beam simultaneously. For the experiments in 1991 and 1992 the original EMC polarized target was reinstalled. In 1993 a new polarized target was put into operati...

  5. Laser - Polarized HE-3 Target Used for a Precision Measurement of the Neutron Spin Structure

    Energy Technology Data Exchange (ETDEWEB)

    Romalis, M

    2003-11-05

    This thesis describes a precision measurement of the deep inelastic neutron spin structure function g{sub 1}{sup n}(x). The main motivation for the experiment is a test of the Bjorken sum rule. Because of smaller statistical errors and broader kinematic coverage than in previous experiments, we are able to study in detail the behavior of the spin structure function g{sub 1}{sup n}(x) for low values of the Bjorken scaling variable x. We find that it has a strongly divergent behavior, in contradiction to the naive predictions of the Regge theory. This calls into question the methods commonly used for extrapolation of g{sub 1}{sup n}(x) to x = 0. The difference between the proton and the neutron spin structure functions is less divergent at low x, so a test of the Bjorken sum rule is possible. We confirm the sum rule with an accuracy of 8%. The experiment was performed at SLAC using a 50 GeV polarized electron beam and a polarized {sup 3}He target. In this thesis the polarized target is described in detail. We used the technique of Rb optical pumping and Rb-He spin exchange to polarize the {sup 3}He. Because of a novel mechanical design our target had the smallest dilution ever achieved for a high density gas target. Since this is a precision measurement, particular efforts were made to reduce the systematic errors due to the uncertainty in the target parameters. Most important parameters were measured by more than one method. We implemented novel techniques for measuring the thickness of the glass windows of the target, the {sup 3}He density, and the polarization. In particular, one of the methods for measuring the gas density relied on the broadening of the Rb optical absorption lines by collisions with {sup 3}He atoms. The calibration of this technique resulted in the most precise measurements of the pressure broadening parameters for {sup 3}He as well as several other gases, which are described in an Appendix. The polarization of the {sup 3}He was also measured by

  6. ROTATION MEASURES ACROSS PARSEC-SCALE JETS OF FANAROFF-RILEY TYPE I RADIO GALAXIES

    International Nuclear Information System (INIS)

    Kharb, P.; Gabuzda, D. C.; O'Dea, C. P.; Shastri, P.; Baum, S. A.

    2009-01-01

    We present the results of a parsec-scale polarization study of three FRI radio galaxies-3C66B, 3C78, and 3C264-obtained with Very Long Baseline Interferometry at 5, 8, and 15 GHz. Parsec-scale polarization has been detected in a large number of beamed radio-loud active galactic nuclei, but in only a handful of the relatively unbeamed radio galaxies. We report here the detection of parsec-scale polarization at one or more frequencies in all three FRI galaxies studied. We detect Faraday rotation measures (RMs) of the order of a few hundred rad m -2 in the nuclear jet regions of 3C78 and 3C264. In 3C66B, polarization was detected at 8 GHz only. A transverse RM gradient is observed across the jet of 3C78. The inner-jet magnetic field, corrected for Faraday rotation, is found to be aligned along the jet in both 3C78 and 3C264, although the field becomes orthogonal further from the core in 3C78. The RM values in 3C78 and 3C264 are similar to those previously observed in nearby radio galaxies. The transverse RM gradient in 3C78, the increase in the degree of polarization at the jet edge, the large rotation in the polarization angles due to Faraday rotation, and the low depolarization between frequencies suggest that a layer surrounding the jet with a sufficient number of thermal electrons and threaded by a toroidal or helical magnetic field is a good candidate for the Faraday rotating medium. This suggestion is tentatively supported by Hubble Space Telescope optical polarimetry but needs to be examined in a greater number of sources.

  7. Attitude and gyro bias estimation by the rotation of an inertial measurement unit

    International Nuclear Information System (INIS)

    Wu, Zheming; Sun, Zhenguo; Zhang, Wenzeng; Chen, Qiang

    2015-01-01

    In navigation applications, the presence of an unknown bias in the measurement of rate gyros is a key performance-limiting factor. In order to estimate the gyro bias and improve the accuracy of attitude measurement, we proposed a new method which uses the rotation of an inertial measurement unit, which is independent from rigid body motion. By actively changing the orientation of the inertial measurement unit (IMU), the proposed method generates sufficient relations between the gyro bias and tilt angle (roll and pitch) error via ridge body dynamics, and the gyro bias, including the bias that causes the heading error, can be estimated and compensated. The rotation inertial measurement unit method makes the gravity vector measured from the IMU continuously change in a body-fixed frame. By theoretically analyzing the mathematic model, the convergence of the attitude and gyro bias to the true values is proven. The proposed method provides a good attitude estimation using only measurements from an IMU, when other sensors such as magnetometers and GPS are unreliable. The performance of the proposed method is illustrated under realistic robotic motions and the results demonstrate an improvement in the accuracy of the attitude estimation. (paper)

  8. Methods of measurement signal acquisition from the rotational flow meter for frequency analysis

    Directory of Open Access Journals (Sweden)

    Świsulski Dariusz

    2017-01-01

    Full Text Available One of the simplest and commonly used instruments for measuring the flow of homogeneous substances is the rotational flow meter. The main part of such a device is a rotor (vane or screw rotating at a speed which is the function of the fluid or gas flow rate. A pulse signal with a frequency proportional to the speed of the rotor is obtained at the sensor output. For measurements in dynamic conditions, a variable interval between pulses prohibits the analysis of the measuring signal. Therefore, the authors of the article developed a method involving the determination of measured values on the basis of the last inter-pulse interval preceding the moment designated by the timing generator. For larger changes of the measured value at a predetermined time, the value can be determined by means of extrapolation of the two adjacent interpulse ranges, assuming a linear change in the flow. The proposed methods allow analysis which requires constant spacing between measurements, allowing for an analysis of the dynamics of changes in the test flow, eg. using a Fourier transform. To present the advantages of these methods simulations of flow measurement were carried out with a DRH-1140 rotor flow meter from the company Kobold.

  9. An experimental study of the effect of tail configuration on the spinning characteristics of general aviation aircraft. M.S. Thesis; [static wind tunnel force measurements

    Science.gov (United States)

    Ballin, M. G.

    1982-01-01

    The feasibility of using static wind tunnel tests to obtain information about spin damping characteristics of an isolated general aviation aircraft tail was investigated. A representative tail section was oriented to the tunnel free streamline at angles simulating an equilibrium spin. A full range of normally encountered spin conditions was employed. Results of parametric studies performed to determine the effect of spin damping on several tail design parameters show satisfactory agreement with NASA rotary balance tests. Wing and body interference effects are present in the NASA studies at steep spin attitudes, but agreement improves with increasing pitch angle and spin rate, suggesting that rotational flow effects are minimal. Vertical position of the horizontal stabilizer is found to be a primary parameter affecting yaw damping, and horizontal tail chordwise position induces a substantial effect on pitching moment.

  10. Measurement of the Proton and Deuteron Spin Structure Functions G1 and G2

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, Al

    2003-04-02

    The SLAC experiment E155 was a deep-inelastic scattering experiment that scattered polarized electrons off polarized proton and deuteron targets in the effort to measure precisely the proton and deuteron spin structure functions. The nucleon structure functions g{sub 1} and g{sub 2} are important quantities that help test our present models of nucleon structure. Such information can help quantify the constituent contributions to the nucleon spin. The structure functions g{sub 1}{sup p} and G{sub 1}{sup d} have been measured over the kinematic range 0.01 {le} x {le} 0.9 and 1 {le} Q{sup 2} {le} 40 GeV{sup 2} by scattering 48.4 GeV longitudinally polarized electrons off longitudinally polarized protons and deuterons. In addition, the structure functions g{sub 2}{sup p} and g{sub 2}{sup d} have been measured over the kinematic range 0.01 {le} x {le} 0.7 and 1 {le} Q{sup 2} {le} 17 GeV{sup 2} by scattering 38.8 GeV longitudinally polarized electrons off transversely polarized protons and deuterons. The measurements of g{sub 1} confirm the Bjorken sum rule and find the net quark polarization to be {Delta}{Sigma} = 0.23 {+-} 0.04 {+-} 0.6 while g{sub 2} is found to be consistent with the g{sub 2}{sup WW} model.

  11. Measurement of the Double Spin Asymmetry in π+ electroproduction with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Raffaella De [Univ. of Genoa (Italy)

    2000-12-01

    The present thesis describes the measurement of the double spin asymmetry in the ep → eπ+n reaction. This represents the only existing measurement for this observable. The reaction is identified detecting the scattered electron and the emitted pion and using the missing mass technique to identify the neutron. The asymmetry is evaluated as a function of the four-momentum transfer Q2, the invariant mass W and the pion center of mass angle θ*. These are in fact the variables that determine the transition amplitudes for the process. The W range of this measurement varies from the pion threshold to a maximum value of 1.8 GeV, exploring the full resonance region. The results obtained with this analysis in the evaluation of the spin asymmetry are presented. The outline of the thesis can be summarized as follows. The first chapter describes the physics motivation that are at the basis of this experiment. The second and third chapters illustrate the design of the CLAS detector and the polarized target. The fourth chapter gives a description of the event reconstruction and to the event selection while the analysis procedure is described in chapter five. Chapter six discusses the results of this measurement, including the evaluation of the systematic uncertainty and the comparison with a physics model.

  12. Effects of stray lights on Faraday rotation measurement for polarimeter-interferometer system on EAST

    Science.gov (United States)

    Zou, Z. Y.; Liu, H. Q.; Ding, W. X.; Chen, J.; Brower, D. L.; Lian, H.; Wang, S. X.; Li, W. M.; Yao, Y.; Zeng, L.; Jie, Y. X.

    2018-01-01

    A double-pass radially view 11 chords polarimeter-interferometer system has been operated on the experimental advanced superconducting tokamak and provides important current profile information for plasma control. Stray light originating from spurious reflections along the optical path (unwanted reflections from various optical components/mounts and transmissive optical elements such as windows, waveplates, and lens as well as the detectors) and also direct feedback from the retro-reflector used to realize the double-pass configuration can both contribute to contamination of the Faraday rotation measurement accuracy. Modulation of the Faraday rotation signal due to the interference from multiple reflections is observable when the interferometer phase (plasma density) varies with time. Direct reflection from the detector itself can be suppressed by employing an optical isolator consisting of a λ/4-waveplate and polarizer positioned in front of the mixer. A Faraday angle oscillation during the density ramping up (or down) can be reduced from 5°-10° to 1°-2° by eliminating reflections from the detector. Residual modulation arising from misalignment and stray light from other sources must be minimized to achieve accurate measurements of Faraday rotation.

  13. Infrared pyrometer for high resolution surface temperature measurements on rotating turbine blades

    Science.gov (United States)

    Uguccini, O. W.

    1976-01-01

    A high resolution pyrometer was developed and used to obtain temperature profiles of rotating turbine blades at tip speeds up to 366 meters per second (1200 fps). Surface temperature variations from 920 to 1250 K (1200 to 1800 F) can be measured and variations over distances of 0.05 cm (0.020 in.) can be resolved. Temperature profiles were obtained in near real time as hard copies from a computer display terminal. Temperatures measured with the prototype pyrometer and with thermocouples agreed to within 2 percent over the temperature range from 977 to 1144 K (1300 to 1600 F).

  14. Infrared pyrometer for high resolution surface temperature measurement on rotating turbine blades

    Science.gov (United States)

    Uguccini, O. W.

    1976-01-01

    A high resolution pyrometer was developed and used to obtain temperature profiles of rotating turbine blades at tip speeds up to 366 meters per second. Surface temperature variations from 920 to 1250 K can be measured and variations over distances of 0.05 cm can be resolved. Temperature profiles were obtained in near real time as hard copies from a computer display terminal. Temperatures measured with the prototype pyrometer and with thermocouples agreed to within 2 percent over the temperature range from 977 to 1144.

  15. First Toroidal Rotation Measurements of Protons and Impurities in the TJ-II Stellarator

    International Nuclear Information System (INIS)

    Rapisarda, D.; Zurro, B.; Baciero, A.

    2006-01-01

    First absolute toroidal rotation measurements in the TJ-II stellarator, by using passive emission spectroscopy, are presented. The wavelength calibration is performed by using a spectral system which combines the spectra coming from the plasma and from a lamp in real time. Measurements have been made both for protons and some impurity ions (C4+, He+), in discharges created by electron cyclotron resonance heating, and in discharges with neutral beam injection heating. In addition, a description of the systems as well as the calibration procedures an data analysis is addressed. (Author) 10 refs

  16. Mass and Spin Measurement with M{sub T2} and MAOS Momentum

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Sang [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Choi, Kiwoon [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Kim, Yeong Gyun [Physics Division, Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of); Park, Chan Beom [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

    2010-03-15

    We discuss the M{sub T2}-kink method to determine the masses of both the dark matter WIMP and its mother particle produced at the LHC. We then introduce a new kinematic variable, the M{sub T2}-Assisted-On-Shell (MAOS) momentum, that provides a systematic approximation to the invisible particle momenta in hadron collider events producing a pair of invisible particles, and apply it to certain SUSY processes and their UED equivalents to determine the spin of gluino/KK-gluon and of slepton/KK-lepton. An application of the MAOS momentum to the SM Higgs mass measurement is briefly discussed also.

  17. Probing the superconducting ground state of the rare-earth ternary boride superconductors R RuB2 (R = Lu,Y) using muon-spin rotation and relaxation

    Science.gov (United States)

    Barker, J. A. T.; Singh, R. P.; Hillier, A. D.; Paul, D. McK.

    2018-03-01

    The superconductivity in the rare-earth transition-metal ternary borides R RuB2 (where R =Lu and Y) has been investigated using muon-spin rotation and relaxation. Measurements made in zero field suggest that time-reversal symmetry is preserved upon entering the superconducting state in both materials; a small difference in depolarization is observed above and below the superconducting transition in both compounds, however, this has been attributed to quasistatic magnetic fluctuations. Transverse-field measurements of the flux-line lattice indicate that the superconductivity in both materials is fully gapped, with a conventional s -wave pairing symmetry and BCS-like magnitudes for the zero-temperature gap energies. The electronic properties of the charge carriers in the superconducting state have been calculated, with effective masses m*/me=9.8 ±0.1 and 15.0 ±0.1 in the Lu and Y compounds, respectively, with superconducting carrier densities ns=(2.73 ±0.04 ) ×1028m-3 and (2.17 ±0.02 ) ×1028m-3 . The materials have been classified according to the Uemura scheme for superconductivity, with values for Tc/TF of 1 /(414 ±6 ) and 1 /(304 ±3 ) , implying that the superconductivity may not be entirely conventional in nature.

  18. Multichannel spin polarimeter for energy- and angle-dispersive photoemission measurements; Vielkanal-Spinpolarimeter fuer energie- und winkeldispersive Photoemissionsmessungen

    Energy Technology Data Exchange (ETDEWEB)

    Kolbe, Michaela

    2011-09-09

    Spin polarization measurements of free electrons remain challenging since their first realization by Mott. The relevant quantity of a spin polarimeter is its figure of merit, FoM=S{sup 2}I/I{sub 0}, with the asymmetry function S and the ratio between scattered and primary intensity I/I{sub 0}. State-of-the-art devices are based on single-channel scattering (spin-orbit or exchange interaction) which is characterized by FoM {approx_equal}10{sup -4}. On the other hand, modern hemispherical analyzers feature an efficient multichannel detection of spin-integral intensity with more than 10{sup 4} data points simultaneously. In comparison between spin-resolved and spin-integral electron spectroscopy we are thus faced with a difference in counting efficiency by 8 orders of magnitude. The present work concentrates on the development and investigation of a novel technique for increasing the efficiency in spin-resolved electron spectroscopy by multichannel detection. The spin detector was integrated in a {mu}-metal shielded UHV-chamber and mounted behind a conventional hemispherical analyzer. The electrostatic lens system's geometry was determined by electron-optical simulations. The basic concept is the k {sub parallel} -conserving elastic scattering of the (0,0)-beam on a W(100) scattering crystal under 45 impact angle. It could be demonstrated that app. 960 data points (15 energy and 64 angular points) could be displayed simultaneously on a delayline detector in an energy interval of {approx_equal}3 eV. This leads to a two-dimensional figure of merit of FoM{sub 2D}=1.7. Compared to conventional spin detectors, the new type is thus characterized by a gain in efficiency of 4 orders of magnitude. The operational reliability of the new spin polarimeter could be proven by measurements with a Fe/MgO(100) and O p(1 x 1)/Fe(100)-sample, where results from the literature were reproduced with strongly decreased measuring time. Due to the high intensity it becomes possible, to

  19. Anomalous magnetic structure and spin dynamics in magnetoelectric LiFePO4

    DEFF Research Database (Denmark)

    Toft-Petersen, Rasmus; Reehuis, Manfred; Jensen, Thomas Bagger Stibius

    2015-01-01

    We report significant details of the magnetic structure and spin dynamics of LiFePO4 obtained by single-crystal neutron scattering. Our results confirm a previously reported collinear rotation of the spins away from the principal b axis, and they determine that the rotation is toward the a axis...... with earlier susceptibility measurements. Using a spin Hamiltonian, we show that the spin dimensionality is intermediate between XY- and Ising-like, with an easy b axis and a hard c axis. It is shown that both next-nearest neighbor exchange couplings in the bc plane are in competition with the strongest...

  20. Design for coordinated measurements of Faraday rotation and line-of-sight electron density using heterodyne techniques

    International Nuclear Information System (INIS)

    Jacobson, A.R.

    1977-07-01

    This report proposes a device which can overcome certain of the compromises of conventional Faraday rotation methods and at the same time measure the optical phase as well as the polarization. This would be useful for unfolding the Faraday rotation signal using the line-of-sight density along exactly the same path. Preliminary design parameters using a CO 2 laser are presented

  1. Optically-detected spin-echo method for relaxation times measurements in a Rb atomic vapor

    Science.gov (United States)

    Gharavipour, M.; Affolderbach, C.; Gruet, F.; Radojičić, I. S.; Krmpot, A. J.; Jelenković, B. M.; Mileti, G.

    2017-06-01

    We introduce and demonstrate an experimental method, optically-detected spin-echo (ODSE), to measure ground-state relaxation times of a rubidium (Rb) atomic vapor held in a glass cell with buffer-gas. The work is motivated by our studies on high-performance Rb atomic clocks, where both population and coherence relaxation times (T 1 and T 2, respectively) of the ‘clock transition’ (52S1/2 | {F}g = 1,{m}F=0> ≤ftrightarrow | {F}g=2,{m}F=0> ) are relevant. Our ODSE method is inspired by classical nuclear magnetic resonance spin-echo method, combined with optical detection. In contrast to other existing methods, like continuous-wave double-resonance (CW-DR) and Ramsey-DR, principles of the ODSE method allow suppression of decoherence arising from the inhomogeneity of the static magnetic field across the vapor cell, thus enabling measurements of intrinsic relaxation rates, as properties of the cell alone. Our experimental result for the coherence relaxation time, specific for the clock transition, measured with the ODSE method is in good agreement with the theoretical prediction, and the ODSE results are validated by comparison to those obtained with Franzen, CW-DR and Ramsey-DR methods. The method is of interest for a wide variety of quantum optics experiments with optical signal readout.

  2. A measure of monopole inertia in the quantum spin ice Yb2Ti2O7

    Science.gov (United States)

    Pan, Lidong; Laurita, N. J.; Ross, Kate A.; Gaulin, Bruce D.; Armitage, N. P.

    2016-04-01

    An important and continuing theme of modern solid state physics is the realization of exotic excitations in materials, known as quasiparticles, that have no analogy in the actual physical vacuum of free space. Although they are not fundamental, such quasiparticles do constitute the most basic description of the excited states of the `vacuum' in which they reside. In this regard the magnetic textures of the excited states of spin ices, magnetic pyrochlore oxides with dominant Ising interactions, have been proposed to behave as effective magnetic charge monopoles. Inelastic neutron scattering experiments have established the pyrochlore material Yb2Ti2O7 (YbTO) as a quantum spin ice, where, in addition to the Ising interactions, there are substantial transverse terms that may induce quantum dynamics and--in principle--coherent monopole motion. Here we report a combined time-domain terahertz spectroscopy (TDTS) and microwave cavity study of YbTO to probe its complex dynamic magnetic susceptibility. We find that the form of the susceptibility is consistent with that of a monopole gas, and a magnetic monopole conductivity can be defined and measured. Using the phase sensitive capabilities of these techniques, we observe a sign change in the reactive part of the magnetic response. In generic models of magnetic excitations this is possible only by introducing inertial effects, such as a mass-dependent term, to the equations of motion. Analogous to conventional electric charge systems, measurement of the conductivity's spectral weight allows us to derive a value for the magnetic monopole mass. Our results support the idea of magnetic monopoles of quantum spin ice as the true coherently propagating quasiparticles of this system.

  3. Simulation and analysis of spectroscopic filter of rotational Raman lidar for absolute measurement of atmospheric temperature

    Science.gov (United States)

    Li, Qimeng; Li, Shichun; Hu, Xianglong; Zhao, Jing; Xin, Wenhui; Song, Yuehui; Hua, Dengxin

    2018-01-01

    The absolute measurement technique for atmospheric temperature can avoid the calibration process and improve the measurement accuracy. To achieve the rotational Raman temperature lidar of absolute measurement, the two-stage parallel multi-channel spectroscopic filter combined a first-order blazed grating with a fiber Bragg grating is designed and its performance is tested. The parameters and the optical path structure of the core cascaded-device (micron-level fiber array) are optimized, the optical path of the primary spectroscope is simulated and the maximum centrifugal distortion of the rotational Raman spectrum is approximately 0.0031 nm, the centrifugal ratio of 0.69%. The experimental results show that the channel coefficients of the primary spectroscope are 0.67, 0.91, 0.67, 0.75, 0.82, 0.63, 0.87, 0.97, 0.89, 0.87 and 1 by using the twelfth channel as a reference and the average FWHM is about 0.44 nm. The maximum deviation between the experimental wavelength and the theoretical value is approximately 0.0398 nm, with the deviation degree of 8.86%. The effective suppression to elastic scattering signal are 30.6, 35.2, 37.1, 38.4, 36.8, 38.2, 41.0, 44.3, 44.0, 46.7 dB. That means, combined with the second spectroscope, the suppression at least is up to 65 dB. Therefore we can fine extract single rotational Raman line to achieve the absolute measurement technique.

  4. Measurements of Drag Coefficients and Rotation Rates of Free-Falling Helixes

    KAUST Repository

    Al-Omari, Abdulrhaman A.

    2016-05-01

    The motion of bacteria in the environment is relevant to several fields. At very small scales and with simple helical shapes, we are able to describe experimentally and mathematically the motion of solid spirals falling freely within a liquid pool. Using these shapes we intend to mimic the motion of bacteria called Spirochetes. We seek to experimentally investigate the linear and the rotational motion of such shapes. A better understanding of the dynamics of this process will be practical not only on engineering and physics, but the bioscience and environmental as well. In the following pages, we explore the role of the shape on the motion of passive solid helixes in different liquids. We fabricate three solid helical shapes and drop them under gravity in water, glycerol and a mixture of 30% glycerol in water. That generated rotation due to helical angle in water. However, we observe the rotation disappear in glycerol. The movement of the solid helical shapes is imaged using a high-speed video camera. Then, the images are analyzed using the supplied software and a computer. Using these simultaneous measurements, we examine the terminal velocity of solid helical shapes. Using this information we computed the drag coefficient and the drag force. We obtain the helical angular velocity and the torque applied to the solid. The results of this study will allow us to more accurately predict the motion of solid helical shape. This analysis will also shed light onto biological questions of bacteria movement.

  5. Local measurement of error field using naturally rotating tearing mode dynamics in EXTRAP T2R

    Science.gov (United States)

    Sweeney, R. M.; Frassinetti, L.; Brunsell, P.; Fridström, R.; Volpe, F. A.

    2016-12-01

    An error field (EF) detection technique using the amplitude modulation of a naturally rotating tearing mode (TM) is developed and validated in the EXTRAP T2R reversed field pinch. The technique was used to identify intrinsic EFs of m/n  =  1/-12, where m and n are the poloidal and toroidal mode numbers. The effect of the EF and of a resonant magnetic perturbation (RMP) on the TM, in particular on amplitude modulation, is modeled with a first-order solution of the modified Rutherford equation. In the experiment, the TM amplitude is measured as a function of the toroidal angle as the TM rotates rapidly in the presence of an unknown EF and a known, deliberately applied RMP. The RMP amplitude is fixed while the toroidal phase is varied from one discharge to the other, completing a full toroidal scan. Using three such scans with different RMP amplitudes, the EF amplitude and phase are inferred from the phases at which the TM amplitude maximizes. The estimated EF amplitude is consistent with other estimates (e.g. based on the best EF-cancelling RMP, resulting in the fastest TM rotation). A passive variant of this technique is also presented, where no RMPs are applied, and the EF phase is deduced.

  6. Spin polarization of (Ga,Mn)As measured by Andreev spectroscopy: the role of spin-active scattering

    Czech Academy of Sciences Publication Activity Database

    Piano, S.; Grein, R.; Mellor, C.J.; Výborný, Karel; Campion, R.; Wang, M.; Eschrig, M.; Gallagher, B. L.

    2011-01-01

    Roč. 83, č. 8 (2011), 081305/1-081305/4 ISSN 1098-0121 R&D Projects: GA AV ČR KJB100100802; GA MŠk(CZ) 7E08087 EU Projects: European Commission(XE) 214499 - NAMASTE; European Commission(XE) 237375 - SemiSpinNano Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : Andreev spectroscopy * magnetic semiconductors Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  7. Slowly Spinning Southern M Dwarfs

    Science.gov (United States)

    Newton, Elisabeth; Mondrik, Nicholas; Irwin, Jonathan; Charbonneau, David

    2018-01-01

    M dwarf stars are the most common type of star in the galaxy, but their ages are challenging to determine due to their trillion-year lifetimes on the main sequence. Consequently, the evolution of rotation and magnetism at field ages is difficult to investigate observationally. M dwarfs in the Solar Neighborhood provide a unique opportunity to make progress in this area due to the availability of parallaxes and the accessibility of spectroscopy. We have used new rotation period measurements and our compilation of H-alpha emission for nearby M dwarfs to explore two questions: 1) What is the longest rotation period an M dwarf can have? And 2) Do M dwarfs undergo an era of rapid angular momentum evolution? Here, we focus on the view from the Southern hemisphere, presenting approximately 200 new rotation periods for fully convective M dwarfs. Amongst the highest-quality datasets, we identify rotation periods in three-quarters of all stars; of these, half have rotation periods longer than 70 days. The longest rotation period we detect is 148 days, which is for a 0.15 solar-mass star. The lack of M dwarfs with intermediate rotation periods that we previously identified persists, supporting our hypothesis that M dwarfs rapidly spin down from 10-day to 100-day periods.ERN is supported by the National Science Foundation Astronomy & Astrophysics Postdoctoral Fellowship. We gratefully acknowledge support from the David and Lucille Packard Foundation, the National Science Foundation, and the John Templeton Foundation.

  8. Application of interferometry and Faraday rotation techniques for density measurements on ITER

    International Nuclear Information System (INIS)

    Snider, R.T.; Carlstrom, T.N.; Ma, C.H.; Peebles, W.A.

    1995-01-01

    There is a need for real time, reliable density measurement for density control, compatible with the restricted access and radiation environment on ITER. Line average density measurements using microwave or laser interferometry techniques have proven to be robust and reliable for density control on contemporary tokamaks. In ITER, the large path length, high density and density gradients, limit the wavelength of a probing beam to shorter then about 50 microm due to refraction effects. In this paper the authors consider the design of short wavelength vibration compensated interferometers and Faraday rotation techniques for density measurements on ITER. These techniques allow operation of the diagnostics without a prohibitively large vibration isolated structure and permits the optics to be mounted directly on the radial port plugs on ITER. A beam path designed for 10.6 microm (CO2 laser) with a tangential path through the plasma allows both an interferometer and a Faraday rotation measurement of the line average density with good density resolution while avoiding refraction problems. Plasma effects on the probing beams and design tradeoffs will be discussed along with radiation and long pulse issues. A proposed layout of the diagnostic for ITER will be present

  9. Measurements of spin alignment of vector mesons and global polarization of hyperons with ALICE at the LHC

    Science.gov (United States)

    Mohanty, Bedangadas

    2018-02-01

    We present the measurements related to global polarization of Λ hyperons and spin alignment of K*0 vector mesons at mid-rapidity for Pb-Pb collisions at = 2.76 TeV using the ALICE detector at the LHC. The global polarization measurements are carried out with respect to the first order event plane while the spin alignment measurements are carried out with respect to the production plane. No global polarization signal for Λ is observed for 5-15% and 15-50% central Pb-Pb collisions. The spin density matrix element ρ00 is found to have values slightly below ⅓ at low transverse momentum (pT) for K*0 mesons, while it is consistent with ⅓ (no spin alignment) at higher pT. No spin alignment is observed for K*0 in pp collisions at √s = 13 TeV and for the spin zero hadron K0S in 20-40% Pb-Pb collisions at = 2.76 TeV.

  10. The Precision Measurement of the Neutron Spin Structure Function Using Polarized HE-3 Target

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X

    2004-01-05

    Using a 48.6 GeV polarized electron beam scattering off a polarized {sup 3}He target at Stanford Linear Accelerator Centre (SLAC), they measured the neutron spin structure function g{sub 1}{sup n} over kinematic(x) ranging 0.014 < x <0.7 and 1 < Q{sup 2} < 17GeV{sup 2}. The measurement gave the integral result over the neutron spin structure function {integral}{sub 0.014}{sup 0.7} g{sub 1}{sup n}(x)dx = -0.036 {+-} 0.004(stat) {+-} 0.005(syst) at an average Q{sup 2} = 5GeV{sup 2}. Along with the proton results from SLAC E143 experiment (0.03 < x) and SMC experiment (0.014 < x < 0.03), they find the Bjorken sum rule appears to be largely saturated by the data integrated down to x of 0.014. However, they observe relatively large values for g{sub 1}{sup n} at low x. The result calls into question the usual methods (Regge theory) for extrapolating to x = 0 to find the full neutron integral {integral}{sub 0}{sup t} g{sub 1}{sup n}(x) dx, needed for testing the Quark-Parton Model (QMP).

  11. Methodology of heat transfer and flow resistance measurement for matrices of rotating regenerative heat exchangers

    Directory of Open Access Journals (Sweden)

    Butrymowicz Dariusz

    2016-09-01

    Full Text Available The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.

  12. Noninvasive measurements of regional cerebral perfusion in preterm and term neonates by magnetic resonance arterial spin labeling

    DEFF Research Database (Denmark)

    Miranda Gimenez-Ricco, Maria Jo; Olofsson, K; Sidaros, Karam

    2006-01-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term-born neon......Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term...

  13. A measurement of the absolute neutron beam polarization produced by an optically pumped 3He neutron spin filter

    International Nuclear Information System (INIS)

    Rich, D.R.; Bowman, J.D.; Crawford, B.E.; Delheij, P.P.J.; Espy, M.A.; Haseyama, T.; Jones, G.; Keith, C.D.; Knudson, J.; Leuschner, M.B.; Masaike, A.; Masuda, Y.; Matsuda, Y.; Penttilae, S.I.; Pomeroy, V.R.; Smith, D.A.; Snow, W.M.; Szymanski, J.J.; Stephenson, S.L.; Thompson, A.K.; Yuan, V.

    2002-01-01

    The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized 3 He spin filter and a relative transmission measurement technique. 3 He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method

  14. Stability of trans-fermium elements at high spin: Measuring the fission barrier of 254No

    International Nuclear Information System (INIS)

    Henning, Greg

    2012-01-01

    Super heavy nuclei provide opportunities to study nuclear structure near three simultaneous limits: in charge Z, spin I and excitation energy E*. These nuclei exist only because of a fission barrier, created by shell effects. It is therefore important to determine the fission barrier and its spin dependence B f (I), which gives information on the shell energy E(shell)(I). Theoretical calculations predict different fission barrier heights from B f (I = 0) = 6.8 MeV for a macro-microscopic model to 8.7 MeV for Density Functional Theory calculations using the Gogny or Skyrme interactions. Hence, a measurement of B f provides a test for theories.To investigate the fission barrier, an established method is to measure the rise of fission with excitation energy, characterized by the ratio of decay widths Γ(fission)/Γ(total), using transfer reactions. However, for heavy elements such as 254 No, there is no suitable target for a transfer reaction. We therefore rely on the complementary decay widths ratio Γ γ /Γ(fission) and its spin dependence, deduced from the entry distribution (I, E*).Measurements of the gamma-ray multiplicity and total energy for 254 No have been performed with beam energies of 219 and 223 MeV in the reaction 208 Pb( 48 Ca,2n) at ATLAS (Argonne Tandem Linac Accelerator System). The 254 No gamma rays were detected using the Gammasphere array as a calorimeter - as well as the usual high resolution γ-ray detector. Coincidences with evaporation residues at the Fragment Mass Analyzer focal plane separated 254 No gamma rays from those from fission fragments, which are ≥ 10 6 more intense. From this measurement, the entry distribution - i.e. the initial distribution of I and E* - is constructed. Each point (I,E*) of the entry distribution is a point where gamma decay wins over fission and, therefore, gives information on the fission barrier. The measured entry distributions show an increase in the maximum spin and excitation energy from 219 to 223 Me

  15. Measurement of transverse single-spin asymmetries in inclusive electroproduction at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Ruiz, Alejandro

    2012-12-15

    This dissertation describes the measurement of two single-spin asymmetries (SSAs) in the production of particles from inelastic lepton-proton collisions. SSAs are a convenient observable for investigating the spin-dependent part of the electron-proton cross section. The analyzed data were taken by the HERMES experiment at DESY, using a 27.6 GeV electron/positron beam and a static hydrogen target in which the proton spin was polarized transversely to the direction of the beam. In the first case, SSAs were investigated in the inclusive electroproduction of charged pions and kaons. The asymmetries were studied as a function of the hadron momentum, p{sub T}, relative to the direction of the incident beam, and the Feynman variable x{sub F}. In the kinematic range 0.08 GeVmeasured for positive hadrons, rising from zero at low p{sub T} up to about 6% (8%) for pions (kaons) and then decrease again with increasing p{sub T}. For negative hadrons the asymmetries were of much smaller magnitude, sometimes positive and sometimes negative. When binned simultaneously in p{sub T} and x{sub F}, the asymmetries were found to be essentially independent of x{sub F} in each slice of p{sub T}. The analyzed data were manifestly dominated by hadrons from quasi-real photoproduction. In these reactions, the asymmetry can be related to the hadronic component of the photon and thus to the asymmetry A{sub N} observed in hadronic collisions at different energies but not yet fully understood. However, the largest contribution to the measured SSAs are from hadrons produced in deep-inelastic scattering (DIS) reactions, related to the Sivers function, which describes the asymmetric distribution of unpolarized quarks in a transversely polarized proton. Transverse SSAs were also measured in inclusive DIS, where only the scattered beam lepton is detected. In this case, non-zero SSAs would arise from two-photon exchange contributions to

  16. Spin-mechatronics [Journal of the Physical Society of Japan, ISSN 0031-9015, Jan 2017, v. 86(1)

    International Nuclear Information System (INIS)

    Matsuo, Mamoru; Saitoh, Eiji; Maekawa, Sadamichi

    2017-01-01

    We investigate the interconversion phenomena between spin and mechanical angular momentum in moving objects. In particular, the recent results on spin manipulation and spin-current generation by mechanical motion are examined. In accelerating systems, spin-dependent gauge fields emerge, which enable the conversion from mechanical angular momentum into spins. Such a spin-mechanical effect is predicted by quantum theory in a non-inertial frame. Experiments which confirm the effect, i.e., the resonance frequency shift in nuclear magnetic resonance, the stray field measurement of rotating metals, and electric voltage generation in liquid metals, are discussed. (author)

  17. Characterization of magnetic field profiles at RFX-mod by Faraday rotation measurements

    Science.gov (United States)

    Auriemma, Fulvio; Brombin, Matteo; Canton, Alessandra; Giudicotti, Leonardo; Innocente, Paolo; Zilli, Enrico

    2009-11-01

    A multichannel far-infrared (FIR, λ=118.8 μm) polarimeter has been recently upgraded and re-installed on RFX-mod to measure the Faraday rotation angle along five vertical chords. Polarimetric data, associated with electron density profile, allow the reconstruction of the poloidal magnetic field profile. In this work the setup of the diagnostic is presented and the first Faraday rotation measurements are analyzed. The measurements have been performed at plasma current above 1.2 MA and electron density between 2 and 6x10^19 m-3. The actual S/N ratio is slightly lower than the expected one, due to electromagnetic coupling of the detectors with the saddle coils close to the polarimeter position. Due to this limit, only average information in the flat-top phase of the discharge could be so far obtained. The experimental data have been compared with the result of the μ&p equilibrium model [1], showing a good agreement between experiment and model, whereas the main differences are in the external region of the plasma. A different parameterization of the μ=μ0 J.B/B^2 profile has been proposed to enhance the agreement between model and experiment. [0pt] [1] Ortolani and Snack, World Scientific (1993) Singapore

  18. Ability and sex differences in spatial thinking: What does the mental rotation test really measure?

    Science.gov (United States)

    Hegarty, Mary

    2017-08-14

    Spatial ability tests are often interpreted as measuring facility with imagined spatial transformations of objects. But some spatial ability tests can be solved by analytic strategies as well as imagery transformation strategies. In the present study, participants gave verbal protocols while completing items on the Vandenberg and Kuse (Perceptual & Motor Skills, 4, 599-604, 1978) mental rotation test, and/or reported the strategies they had used on the test. Most participants used both imagery transformation and analytic strategies (i.e., feature-based, orientation-independent strategies) to solve the test items. Use of one analytic strategy, the global-shape strategy, was positively correlated with accuracy. Specifically, some of the most successful students used this strategy to eliminate answer choices, reducing the need for mental imagery. Men outperformed women, as is typical on this test, and were more likely than women to use the global-shape strategy, in particular, and more holistic strategies, in general. These results argue against the mental rotation test as a measure of spatial imagery alone and suggest that the ability to discover and use more efficient analytic strategies may be an important additional component of what this test measures.

  19. Small angle-rotated detector emission tomography for measuring holdup in spherical container

    International Nuclear Information System (INIS)

    Deng Jingshan; Li Ze; Gan Lin; Lu Wenguang; Dong Mingli

    2007-01-01

    Some special nuclear material (SNM) is inevitably deposited in the facilities (mixer, reactor) of nuclear material process line. Exactly knowing the quantity of nuclear material holdup is very important for nuclear material accountability and critical safety. The small angle-rotated emission tomography method was presented for SNM holdup measurement of spherical container. Because of other equipments exist at the left, right and back side of the container, so that the detectors can be put only in front of container for measurement. The nuclear material deposited in the spherical container can be looked as spherical shell source, which is divided into many voxels. The detectors scanning spherical shell source are rotated around the container at small angle at each layer to obtain projection data, with which deposited material distribution can be reconstructed by using least square (LS) method or maximum likelihood (ML) method. Based on these methods accurate total holdup can be obtained by summing up all the voxel values reconstructed. The measurement method for holdup in the spherical container was verified with Monte-Carlo simulation calculation. (authors)

  20. Evidence of magnetic field in plasma focus by means of Faraday rotation measurements

    International Nuclear Information System (INIS)

    Fischfeld, G.

    1982-01-01

    Preliminary results of Faraday rotation measurements on a beam of laser light crossing the plasma column in the axial direction. are repacted. The presence of intense axial magnetic field Bsup(z) in the column both before and during the pinch phase is demonstrated. The experiments were performed on the Mather type Frascati 1 MJ plasma Focus, operated at 250 KJ 3 torr D 2 filling pressure. Is is used in the measurements a Quantel YG 49 YAG laser, frecuency doubled by means of KD*P crystal, which delivers about 60 mJ in 3 ns at = 530 nm. The beam polarization is analized by Wollaston prism. The electronic density is determined by Mach-Zender insterferometry. Two measurements are taken at time close to the end of the radial collapse phase, yielding Faraday rotation angles of 0.25 +- 0.05 rd and 0.56 +- o.05 rd which correspond to values, of axial magnetic fields of b(sup z) = 500 KG and B(sub z) = 400 KG. (Author) [pt

  1. Spin Qubits in GaAs Heterostructures and Gating of InAs Nanowires for Lowtemperature Measurements

    DEFF Research Database (Denmark)

    Nissen, Peter Dahl

    from screening effects. We find that simple, alternating spin filling is not followed. Furthermore, measurement of the exchange splitting, J, indicate two magnetic field dependent transitions lifting spin blockade which is likewise inconsistent with the simplest model for spin filling. The effect...... in lateral quantum dots. First, we incorporate ferromagnetic metal in the depletion gates making them double as micro-magnets supplying magnetic eld gradients allowing spin qubit operation. We demonstrate full tunability of the electron occupation with the magnetic gate structure, combined with a magnetic...... of the magnetic field gradients from the micro-magnet could play a role in the observed differences between the multi- and the few-electron double dots....

  2. Measurement of the spin-dependent structure function g$_{1}$(x) of the proton

    CERN Document Server

    Adams, D.; Arik, E.; Arvidson, A.; Badelek, B.; Ballintijn, M.K.; Bardin, G.; Baum, Guenter; Berglund, P.; Betev, L.; Bird, I.G.; Birsa, R.; Bjorkholm, P.; Bonner, B.E.; de Botton, N.; Bradamante, F.; Bressan, A.; Brull, A.; Bueltmann, Stephen L.; Burtin, E.; Cavata, C.; Clocchiatti, M.; Corcoran, M.D.; Crabb, D.; Cranshaw, J.; Crawford, M.; Cuhadar, T.; Dalla Torre, S.; van Dantzig, R.; Dhawan, S.; Dulya, C.; Dyring, A.; Eichblatt, S.; Faivre, J.C.; Fasching, D.; Feinstein, F.; Fernandez, C.; Frois, B.; Garzon, J.A.; Gaussiran, T.; Giorgi, M.; von Goeler, E.; Gracia, G.; de Groot, N.; Grosse Perdekamp, M.; Gulmez, Erhan; von Harrach, D.; Hasegawa, T.; Hautle, P.; Hayashi, N.; Heusch, C.A.; Horikawa, N.; Hughes, V.W.; Igo, G.; Ishimoto, S.; Iwata, T.; Kabuss, E.M.; Kaiser, R.; Karev, A.; Kessler, H.J.; Ketel, T.J.; Kishi, A.; Kiselev, Yu.; Klostermann, L.; Kramer, D.; Krivokhijine, V.; Kukhtin, V.; Kyynarainen, J.; Lamanna, M.; Landgraf, U.; Lau, K.; Layda, T.; Le Goff, J.M.; Lehar, F.; de Lesquen, A.; Lichtenstadt, J.; Lindqvist, T.; Litmaath, M.; Lopez-Ponte, S.; Lowe, M.; Magnon, A.; Mallot, G.K.; Marie, F.; Martin, A.; Martino, J.; Matsuda, T.; Mayes, B.; McCarthy, J.S.; Medved, K.; van Middelkoop, G.; Miller, D.; Mori, K.; Moromisato, J.; Nagaitsev, A.; Nassalski, J.; Naumann, L.; Niinikoski, T.O.; Oberski, J.E.J.; Parks, D.P.; Penzo, A.; Perez, G.; Kunne, F.; Peshekhonov, D.; Piegaia, R.; Pinsky, Lawrence S.; Platchkov, S.; Plo, M.; Pose, D.; Postma, H.; Pretz, J.; Pussieux, T.; Pyrlik, J.; Reyhancan, I.; Rieubland, J.M.; Rijllart, A.; Roberts, J.B.; Rock, S.; Rodriguez, M.; Rondio, E.; Rosado, A.; Sabo, I.; Saborido, J.; Sandacz, A.; Savin, Igor A.; Schiavon, P.; Schuler, P.; Segel, R.; Seitz, R.; Semertzidis, Y.; Sever, F.; Shanahan, P.; Shumeiko, N.; Smirnov, G.; Staude, A.; Steinmetz, A.; Stiegler, U.; Stuhrmann, H.; Teichert, K.M.; Tessarotto, F.; Velasco, M.; Vogt, J.; Voss, R.; Weinstein, R.; Whitten, C.; Windmolders, R.; Willumeit, R.; Wislicki, W.; Witzmann, A.; Zanetti, A.M.; Zhao, J.; the SMC

    1994-01-01

    Abstract : We have measured the spin-dependent structure function g_1^p of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003measurements. A combined analysis of all available proton, deuteron and neutron data confirms the Bjorken sum rule to within 10\\% of the theoretical value.

  3. Measurement of variable magnetic reversal paths in electrically contacted pseudo-spin-valve rings

    International Nuclear Information System (INIS)

    Hayward, T J; Llandro, J; Schackert, F D O; Morecroft, D; Balsod, R B; Bland, J A C; Castano, F J; Ross, C A

    2007-01-01

    In this work we show that the measurement of single magnetic reversal events is of critical importance in order to correctly characterize the switching of magnetic microstructures. Magnetoresistance measurements are performed on two pseudo-spin-valve ring structures with high enough signal to noise to allow the probing of single reversal events. Using this technique we acquire 'switching spectra' which demonstrate that the rings exhibit a range of variable reversal paths, including a bistable reversal mechanism of the hard layer, where the two switching routes have substantially different switching fields. The signature of the variable reversal paths would have been obscured in field cycle averaged data and in the bistable case would cause a fundamental misinterpretation of the reversal behaviour

  4. Homogenization of Doppler broadening in spin-noise spectroscopy

    Science.gov (United States)

    Petrov, M. Yu.; Ryzhov, I. I.; Smirnov, D. S.; Belyaev, L. Yu.; Potekhin, R. A.; Glazov, M. M.; Kulyasov, V. N.; Kozlov, G. G.; Aleksandrov, E. B.; Zapasskii, V. S.

    2018-03-01

    The spin-noise spectroscopy, being a nonperturbative linear optics tool, is still reputed to reveal a number of capabilities specific to nonlinear optics techniques. The effect of the Doppler broadening homogenization discovered in this work essentially widens these unique properties of spin-noise spectroscopy. We investigate spin noise of a classical system—cesium atoms vapor with admixture of buffer gas—by measuring the spin-induced Faraday rotation fluctuations in the region of D 2 line. The line, under our experimental conditions, is strongly inhomogeneously broadened due to the Doppler effect. Despite that, optical spectrum of the spin-noise power has the shape typical for the homogeneously broadened line with a dip at the line center. This fact is in stark contrast with the results of previous studies of inhomogeneous quantum dot ensembles and Doppler broadened atomic systems. In addition, the two-color spin-noise measurements have shown, in a highly spectacular way, that fluctuations of the Faraday rotation within the line are either correlated or anticorrelated depending on whether the two wavelengths lie on the same side or on different sides of the resonance. The experimental data are interpreted in the frame of the developed theoretical model which takes into account both kinetics and spin dynamics of Cs atoms. It is shown that the unexpected behavior of the Faraday rotation noise spectra and effective homogenization of the optical transition in the spin-noise measurements are related to smallness of the momentum relaxation time of the atoms as compared with their spin-relaxation time. Our findings demonstrate abilities of spin-noise spectroscopy for studying dynamic properties of inhomogeneously broadened ensembles of randomly moving spins.

  5. Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system

    Science.gov (United States)

    Shimokawa, Y.; Matsuura, Y.; Hirano, T.; Sakai, K.

    2016-12-01

    Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ṡ s.

  6. Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system.

    Science.gov (United States)

    Shimokawa, Y; Matsuura, Y; Hirano, T; Sakai, K

    2016-12-01

    Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ⋅ s.

  7. Investigation on the wake evolution of contra-rotating propeller using RANS computation and SPIV measurement

    Directory of Open Access Journals (Sweden)

    Kwang-Jun Paik

    2015-05-01

    Full Text Available The wake characteristics of Contra-Rotating Propeller (CRP were investigated using numerical simulation and flow measurement. The numerical simulation was carried out with a commercial CFD code based on a Reynolds Averaged Navier-Stokes (RANS equations solver, and the flow measurement was performed with Stereoscopic Particle Image Velocimetry (SPIV system. The simulation results were validated through the comparison with the experiment results measured around the leading edge of rudder to investigate the effect of propeller operation under the conditions without propeller, with forward propeller alone, and with both forward and aft propellers. The evolution of CRP wake was analyzed through velocity and vorticity contours on three transverse planes and one longitudinal plane based on CFD results. The trajectories of propeller tip vortex core in the cases with and without aft propeller were also compared, and larger wake contraction with CRP was confirmed.

  8. Measurement of the radial velocity of the Sun as a star by means of a reflecting solar system body. The effect of the body rotation

    Science.gov (United States)

    Lanza, A. F.; Molaro, P.

    2015-06-01

    Minor bodies of the solar system can be used to measure the spectrum of the Sun as a star by observing sunlight reflected by their surfaces. To perform an accurate measurement of the radial velocity of the Sun as a star by this method, it is necessary to take into account the Doppler shifts introduced by the motion of the reflecting body. Here we discuss the effect of its rotation. It gives a vanishing contribution only when the inclinations of the body rotation axis to the directions of the Sun and of the Earth observer are the same. When this is not the case, the perturbation of the radial velocity does not vanish and can reach up to ˜2.4 m/s for an asteroid such as 2 Pallas that has an inclination of the spin axis to the plane of the ecliptic of ˜30∘. We introduce a geometric model to compute the perturbation in the case of a uniformly reflecting body of spherical or triaxial ellipsoidal shape and provide general results to easily estimate the magnitude of the effect.

  9. Measurement of transverse single-spin asymmetries in inclusive electroproduction at HERMES

    International Nuclear Information System (INIS)

    Lopez Ruiz, Alejandro

    2012-12-01

    This dissertation describes the measurement of two single-spin asymmetries (SSAs) in the production of particles from inelastic lepton-proton collisions. SSAs are a convenient observable for investigating the spin-dependent part of the electron-proton cross section. The analyzed data were taken by the HERMES experiment at DESY, using a 27.6 GeV electron/positron beam and a static hydrogen target in which the proton spin was polarized transversely to the direction of the beam. In the first case, SSAs were investigated in the inclusive electroproduction of charged pions and kaons. The asymmetries were studied as a function of the hadron momentum, p T , relative to the direction of the incident beam, and the Feynman variable x F . In the kinematic range 0.08 GeV T F T up to about 6% (8%) for pions (kaons) and then decrease again with increasing p T . For negative hadrons the asymmetries were of much smaller magnitude, sometimes positive and sometimes negative. When binned simultaneously in p T and x F , the asymmetries were found to be essentially independent of x F in each slice of p T . The analyzed data were manifestly dominated by hadrons from quasi-real photoproduction. In these reactions, the asymmetry can be related to the hadronic component of the photon and thus to the asymmetry A N observed in hadronic collisions at different energies but not yet fully understood. However, the largest contribution to the measured SSAs are from hadrons produced in deep-inelastic scattering (DIS) reactions, related to the Sivers function, which describes the asymmetric distribution of unpolarized quarks in a transversely polarized proton. Transverse SSAs were also measured in inclusive DIS, where only the scattered beam lepton is detected. In this case, non-zero SSAs would arise from two-photon exchange contributions to the electron-proton cross section. This observable is thus a check of the validity of the one-photon exchange approximation, commonly used in theoretical

  10. A measurement of the proton’s spin structure function g2 at low Q2

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Pengjia [Univ. of Science and Technology of China, Hefei (China)

    2015-10-21

    JLab E08-027, a measurement of g2p and the longitudinal-transverse (LT) spin polarizability, successfully collected data from March to May, 2012. Nucleon spin structure study has been an active research area, which has attracted a very large effort from both experimentalists and theorists. The spin structure study for the last 2 decades has provided us with many exciting and often surprising results. Recently, new precision results in the low-to-intermediate momentum transfer Q2 region from JLab have provided extensive information on the nucleon structure in the confinement region and the transition region between asymptotic free to confinement. In particular, the extensive comparisons of experimental results with Chiral Perturbation Theory (the effective theory of QCD at low energy) calculations show general good agreements, but strong disagreement in the case of the neutron LT spin polarizability. This experiment completed the measurements of gp2 and the LT spin polarizability on the proton in the low-to-intermediate Q2 region. The experiment used a polarized proton (NH3) target for the first time in Hall A. Scattered electrons were detected by a pair of Hall A high resolution spectrometer (HRS) with a pair of septum magnets. To avoid too much depolarization of the target, beam current was limited to 50-100 nA during the experiment. Since the existing beam current monitors (BCMs), beam position monitors (BPMs) and calibration methods did not work at such a low current range, new BPM and BCM receivers were designed and used for current condition. A pair of super-harps and a tungsten calorimeter were installed to calibrate the BPMs and BCMs. To compensate for the effect of the 2.5/5T transverse magnet field, two chicane dipole magnets were installed. A pair of slow rasters were installed for the first time in Hall A, combining with a pair of fast raster. The standard Hall A DAQ system and the improved high resolution DAQ system were used to record the detector

  11. Stacked bilayer phosphorene: strain-induced quantum spin Hall state and optical measurement

    Science.gov (United States)

    Zhang, Tian; Lin, Jia-He; Yu, Yan-Mei; Chen, Xiang-Rong; Liu, Wu-Ming

    2015-01-01

    Bilayer phosphorene attracted considerable interest, giving a potential application in nanoelectronics owing to its natural bandgap and high carrier mobility. However, very little is known regarding the possible usefulness in spintronics as a quantum spin Hall (QSH) state of material characterized by a bulk energy gap and gapless spin-filtered edge states. Here, we report a strain-induced topological phase transition from normal to QSH state in bilayer phosphorene, accompanied by band-inversion that changes number from 0 to 1, which is highly dependent on interlayer stacking. When the bottom layer is shifted by 1/2 unit-cell along zigzag/armchair direction with respect to the top layer, the maximum topological bandgap 92.5 meV is sufficiently large to realize QSH effect even at room-temperature. An optical measurement of QSH effect is therefore suggested in view of the wide optical absorption spectrum extending to far infra-red, making bilayer phosphorene a promising candidate for opto-spintronic devices. PMID:26370771

  12. Stacked bilayer phosphorene: strain-induced quantum spin Hall state and optical measurement.

    Science.gov (United States)

    Zhang, Tian; Lin, Jia-He; Yu, Yan-Mei; Chen, Xiang-Rong; Liu, Wu-Ming

    2015-09-15

    Bilayer phosphorene attracted considerable interest, giving a potential application in nanoelectronics owing to its natural bandgap and high carrier mobility. However, very little is known regarding the possible usefulness in spintronics as a quantum spin Hall (QSH) state of material characterized by a bulk energy gap and gapless spin-filtered edge states. Here, we report a strain-induced topological phase transition from normal to QSH state in bilayer phosphorene, accompanied by band-inversion that changes number from 0 to 1, which is highly dependent on interlayer stacking. When the bottom layer is shifted by 1/2 unit-cell along zigzag/armchair direction with respect to the top layer, the maximum topological bandgap 92.5 meV is sufficiently large to realize QSH effect even at room-temperature. An optical measurement of QSH effect is therefore suggested in view of the wide optical absorption spectrum extending to far infra-red, making bilayer phosphorene a promising candidate for opto-spintronic devices.

  13. The Spin Structure of the Proton at Low Q2: A Measurement of the Structure Function g2p

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Chao [Univ. of Virginia, Charlottesville, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-08-31

    The spin structure of the nucleon has remained as one of the key points of interest in hadronic physics, which has attracted many efforts from both experimentalists and theorists. Quantum Chromodynamics (QCD) is the fundamental theory that describes the strong interaction. It has been verified in the asymptotically free region. However, the non-perturbative confinement of quarks within the nucleon is still not well understood within QCD. In the non-perturbative regime, low-energy effective field theories such as chiral perturbation theory (XPT) provide predictions for the spin structure functions. The neutron spin structure functions, gp1 and gp2 , and the proton spin structure function, gp1, have been measured over a wide kinematic range and compared with the theoretical predictions. However, the proton spin structure function, gp2, remains largely unmeasured. The E08-027 collaboration successfully performed the first measurement of the inclusive electron-proton scattering in the kinematic range 0.02 < Q2 < 0.2 GeV2. The experiment took place in experimental Hall A at Jefferson Lab in 2012. A longitudinally polarized electron beam with incident energies between 1.1 GeV and 3.3 GeV was scattered from a longitudinally or transversely polarized NH3 target. Asymmetries and polarized cross-section differences were measured in the resonance region to extract the proton spin structure functions g2. The results allow us to obtain the generalized spin polarizabilities γ0 and δLT and test the Burkhardtt-Cottingham (BC) sum rule. Chiral perturbation theory is expected to work in this kinematic range and this measurement of δLT will give a benchmark test to XPT calculations. This thesis will discuss preliminary results from the E08-027 data analysis.

  14. Optical Tip Clearance Measurements as a Tool for Rotating Disk Characterization

    Directory of Open Access Journals (Sweden)

    Iker García

    2017-01-01

    Full Text Available An experimental investigation on the vibrational behavior of a rotating disk by means of three optical fiber sensors is presented. The disk, which is a scale model of the real disk of an aircraft engine, was assembled in a wind tunnel in order to simulate real operation conditions. The pressure difference between the upstream and downstream sides of the disk causes an airflow that might force the disk to vibrate. To characterize this vibration, a set of parameters was determined by measuring the tip clearance of the disk: the amplitude, the frequency and the number of nodal diameters in the disk. All this information allowed the design of an upgraded prototype of the disk, whose performance was also characterized by the same method. An optical system was employed for the measurements, in combination with a strain gauge mounted on the disk surface, which served to confirm the results obtained. The data of the strain gauge coincided closely with those provided by the optical fiber sensors, thus demonstrating the suitability of this innovative technique to evaluate the vibrational behavior of rotating disks.

  15. The quantum brachistochrone problem for an arbitrary spin in a magnetic field

    Science.gov (United States)

    Kuzmak, A. R.; Tkachuk, V. M.

    2015-06-01

    We consider quantum brachistochrone evolution for a spin-s system on rotational manifolds. Such manifolds are determined by the rotation of the eigenstates of the operator of projection of spin-s on some direction. The Fubini-Study metrics of these manifolds are those of spheres with radii dependent on the value of the spin and on the value of the spin projection. The conditions for optimal evolution of the spin-s system on rotational manifolds are obtained.

  16. Quantification of displacement and velocity noise in vibrometer measurements on transversely moving or rotating surfaces

    Science.gov (United States)

    Dräbenstedt, Alexander

    2007-06-01

    The heterodyne interferometer (vibrometer) is a well established technique for measuring all kinds of mechanical vibrations in a broad range of applications. The non-contact measurement principle relies upon the Doppler (or phase-) shift that laser light experiences when it is reflected by the vibrating surface. The speckle nature of the reflected light imposes problems and creates additional measurement noise if the object is moving transversely through the laser spot or is rotating around an axis perpendicular to the laser direction. Another implication that can arise is cross coupling from in-plane vibrations into the out-of-plane measurement direction when small in-plane vibrations are present. A model is presented in this paper that describes the origin of these disturbances. Using this model it is possible to quantify the amplitude spectrum of the noise in displacement and velocity measurements. This enables the user to calculate the limits of resolvable vibration amplitudes when transverse motion is present. The results of the model have been confirmed well by measurements. In addition, the influence of the surface roughness and beam inclination on the out-of-plane vibration measurements at a tilted surface is investigated. The conditions for the measurability of the profile of a transversely moving surface are derived in this work. It is discussed that the R q-roughness parameter has to be less than λ/4 to obtain the slope information in the speckle-perturbed interferometer signal.

  17. Mass of a spin vortex in a Bose-Einstein condensate.

    Science.gov (United States)

    Turner, Ari M

    2009-08-21

    In contrast with charge vortices, spin vortices in a two-dimensional ferromagnetic condensate move inertially (if the condensate has zero magnetization along an axis). The Magnus force, which prevents the inertial motion of the charge vortices, cancels for spin vortices, because they are composed of two oppositely rotating vortices. The inertial mass of spin vortices varies inversely with the strength of spin-dependent interactions and directly with the width of the condensate layer, and can be measured as a part of experiments on how spin vortices orbit one another. For Rb87 in a 1 microm thick trap, mv approximately 10(-21) kg.

  18. PARSEC-SCALE FARADAY ROTATION MEASURES FROM GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF ACTIVE GALACTIC NUCLEUS JETS

    International Nuclear Information System (INIS)

    Broderick, Avery E.; McKinney, Jonathan C.

    2010-01-01

    It is now possible to compare global three-dimensional general relativistic magnetohydrodynamic (GRMHD) jet formation simulations directly to multi-wavelength polarized VLBI observations of the pc-scale structure of active galactic nucleus (AGN) jets. Unlike the jet emission, which requires post hoc modeling of the nonthermal electrons, the Faraday rotation measures (RMs) depend primarily upon simulated quantities and thus provide a direct way to confront simulations with observations. We compute RM distributions of a three-dimensional global GRMHD jet formation simulation, extrapolated in a self-consistent manner to ∼10 pc scales, and explore the dependence upon model and observational parameters, emphasizing the signatures of structures generic to the theory of MHD jets. With typical parameters, we find that it is possible to reproduce the observed magnitudes and many of the structures found in AGN jet RMs, including the presence of transverse RM gradients. In our simulations, the RMs are generated in the circum-jet material, hydrodynamically a smooth extension of the jet itself, containing ordered toroidally dominated magnetic fields. This results in a particular bilateral morphology that is unlikely to arise due to Faraday rotation in distant foreground clouds. However, critical to efforts to probe the Faraday screen will be resolving the transverse jet structure. Therefore, the RMs of radio cores may not be reliable indicators of the properties of the rotating medium. Finally, we are able to constrain the particle content of the jet, finding that at pc scales AGN jets are electromagnetically dominated, with roughly 2% of the comoving energy in nonthermal leptons and much less in baryons.

  19. Fully automatic measurements of axial vertebral rotation for assessment of spinal deformity in idiopathic scoliosis

    Science.gov (United States)

    Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Vavruch, Ludvig; Tropp, Hans; Knutsson, Hans

    2013-03-01

    Reliable measurements of spinal deformities in idiopathic scoliosis are vital, since they are used for assessing the degree of scoliosis, deciding upon treatment and monitoring the progression of the disease. However, commonly used two dimensional methods (e.g. the Cobb angle) do not fully capture the three dimensional deformity at hand in scoliosis, of which axial vertebral rotation (AVR) is considered to be of great importance. There are manual methods for measuring the AVR, but they are often time-consuming and related with a high intra- and inter-observer variability. In this paper, we present a fully automatic method for estimating the AVR in images from computed tomography. The proposed method is evaluated on four scoliotic patients with 17 vertebrae each and compared with manual measurements performed by three observers using the standard method by Aaro-Dahlborn. The comparison shows that the difference in measured AVR between automatic and manual measurements are on the same level as the inter-observer difference. This is further supported by a high intraclass correlation coefficient (0.971-0.979), obtained when comparing the automatic measurements with the manual measurements of each observer. Hence, the provided results and the computational performance, only requiring approximately 10 to 15 s for processing an entire volume, demonstrate the potential clinical value of the proposed method.

  20. Pure Rotational Raman Lidar for Temperature Measurements from 5-40 Km Over Wuhan, China

    Directory of Open Access Journals (Sweden)

    Li Yajuan

    2016-01-01

    Full Text Available In this paper a pure rotational Raman lidar (PRR was established for the atmospheric temperature measurements from 5 km to 40 km over Wuhan, China (30.5°N, 114.5°E. To extract the expected PRR signals and simultaneously suppress the elastically backscattered light, a high-spectral resolution polychromator for light splitting and filtering was designed. Observational results revealed that the temperature difference measured by PRR lidar and the local radiosonde below 30 km was less than 3.0 K. The good agreement validated the reliability of the PRR lidar. With the 1-h integration and 150-m spatial resolution, the statistical temperature error for PRR lidar increases from 0.4 K at 10 km up to 4 K at altitudes of about 30 km. In addition, the whole night temperature profiles were obtained for study of the long-term observation of atmospheric fluctuations.

  1. Measurement of the linewidth enhancement factor based on nonlinear polarization rotation of semiconductor optical amplifier.

    Science.gov (United States)

    Liu, Guodong; Wu, Chongqing; Wang, Fu; Zhang, Tianyong; Shang, Chao; Gao, Kaiqiang

    2015-06-01

    A simple measurement scheme of the linewidth enhancement factor based on the nonlinear polarization rotation of a semiconductor optical amplifier is proposed. Considering the polarization dependent gain, the relationship between the linewidth enhancement factor and the Stokes vector was derived theoretically. It is proven that the linewidth enhancement factor can be calculated directly from the Stokes parameters without any other assistant measurement system. The results demonstrate that the linewidth enhancement factor varies in a small range from 10.5 to 8.5 for TE mode and from 8.2 to 5.8 for TM mode, respectively, when the input optical power varies from 50 μW to 1 mW and the bias current varies from 90 to 170 mA.

  2. Development of a Rotating Rake Array for Boundary-Layer-Ingesting Fan-Stage Measurements

    Science.gov (United States)

    Wolter, John D.; Arend, David J.; Hirt, Stefanie M.; Gazzaniga, John A.

    2017-01-01

    The recent Boundary-Layer-Ingesting Inlet/Distortion Tolerant Fan wind tunnel experiment at NASA Glenn Research Center's 8- by 6-foot Supersonic Wind Tunnel (SWT) examined the performance of a novel inlet and fan stage that was designed to ingest the vehicle boundary layer in order to take advantage of a predicted overall propulsive efficiency benefit. A key piece of the experiment's instrumentation was a pair of rotating rake arrays located upstream and downstream of the fan stage. This paper examines the development of these rake arrays. Pre-test numerical solutions were sampled to determine placement and spacing for rake pressure and temperature probes. The effects of probe spacing and survey density on the repeatability of survey measurements was examined. These data were then used to estimate measurement uncertainty for the adiabatic efficiency.

  3. The inter-rater reliability of the modified finger goniometer for measuring forearm rotation.

    Science.gov (United States)

    Szekeres, Mike; MacDermid, Joy C; Birmingham, Trevor; Grewal, Ruby

    2016-01-01

    Prospective cohort study. To compare the inter-rater reliability of using a modified finger goniometer (MFG) for the measurement of isolated forearm rotation for patients with distal radius fractures to the currently accepted technique for isolated forearm measurement. The currently accepted method of forearm measurement requires the assessor to visually estimate vertical for the stationary arm and placement of the moveable arm while placing a straight edge along a curved surface. Inter-rater reliability may be limited as assessors may estimate the placement of the goniometer arms differently depending on their experience, posture, and even their positioning relative to the patient. Rather than continue to place a straight edge on a round surface, we evaluate a new technique using an MFG for measuring isolated forearm rotation. Patients with clinically healed distal radius fractures were enrolled in the study. Measurement of active forearm pronation and supination was recorded using 2 separate measurement techniques. These measurements were taken by 2 separate hand therapists with more than 10 years of clinical experience in a tertiary care setting at the beginning and end of hand therapy sessions for 3 consecutive weekly visits. Intraclass correlation coefficients (ICCs), standard error of measurement, and minimal detectable change were calculated for each technique. The point estimates for the MFG method demonstrated a slightly higher ICC than the standard method for pronation (0.86 vs 0.82). For supination, both measurement techniques displayed equally high pooled ICCs (0.95). The standard error of measurements for the MFG were 2.1 for pronation and 1.2 for supination compared with 2.9 (pronation) and 1.2 (supination) for the standard technique. These translate into 90% minimal detectable changes of 5° and 3° for the MFG pronation/supination compared with 7° (pronation) and 3° (supination) for the standard technique, respectively. Although the point

  4. Rotational Raman-based temperature measurements in a high-velocity, turbulent jet

    Science.gov (United States)

    Locke, Randy J.; Wernet, Mark P.; Anderson, Robert C.

    2018-01-01

    Spontaneous rotational Raman scattering spectroscopy is used to acquire measurements of the mean and root mean square (rms) temperature fluctuations in turbulent, high-velocity heated jets. Raman spectra in air were obtained across a matrix of radial and axial locations downstream from a 50 mm diameter nozzle operating from subsonic to supersonic conditions over a wide range of temperatures and Mach numbers, in accordance with the Tanna matrix frequently used in jet noise studies. These data were acquired in the hostile, high noise (115 dB) environment of a large scale open air test facility at NASA Glenn Research Center (GRC). Temperature estimates were determined by performing non-linear least squares fitting of the single shot spectra to the theoretical rotational Stokes spectra of N2 and O2. The laser employed in this study was a high energy, long-pulsed, frequency doubled Nd:YAG laser. One thousand single-shot spectra were acquired at each spatial coordinate. Mean temperature and rms temperature variations were calculated at each measurement location. Excellent agreement between the averaged and single-shot temperatures was observed with an accuracy better than 2.5% for temperature, and rms variations in temperature between  ±2.2% at 296 K and  ±4.5% at 850 K. The mean and normalized rms temperatures measured here were then compared to NASA’s Consensus data set of PIV velocity and turbulence measurements in similar jet flows. The results of this and planned follow-on studies will support NASA GRC’s development of physics-based jet noise prediction, turbulence modeling and aeroacoustic source modeling codes.

  5. Measurement of ep-->ep[pi]0 beam spin asymmetries above the resonance region

    Energy Technology Data Exchange (ETDEWEB)

    De Masi, Rita; Garcon, Michel; Zhao, Bo; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Ball, J.P.; Ball, Jacques; Ball, James; Baltzell, Nathan; Baturin, Vitaly; Battaglieri, Marco; Bedlinskiy, Ivan; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Bertin, Pierre; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Bultmann, S.; Bueltmann, Stephen; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crede, Volker; Dashyan, Natalya; De Sanctis, Enzo; De Vita, Raffaella; Degtiarenko, Pavel; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Djalali, Chaden; Dodge, Gail; Donnelly, Joseph; Doughty, David; Dugger, Michael; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Fradi, Ahmed; Funsten, Herbert; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gonenc, Atilla; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Lee, Tsung-Shung; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; Mazouz, Malek; McKinnon, Bryan; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Michel, Bernard; Mikhaylov, Konstantin; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Price, John; Procureur, Sebastien; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Tur, Clarisse; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Voutier, Eric; Watts, Daniel; Weinstein, Lawrence; Weygand, Dennis; Williams, Michael; Wolin, Elliott; Wood, Michael; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Jixie; Zhao, Zhiwen

    2008-04-01

    The beam spin asymmetry (BSA) in the exclusive reaction e-vector p-->eppi0 was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer (CLAS). The xB,Q2,t, and phi dependences of the pi0 BSA are presented in the deep inelastic regime. The asymmetries are fitted with a sinphi function and their amplitudes are extracted. Overall, they are of the order of 0.04â 0.11 and roughly independent of t. This is the signature of a nonzero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.

  6. Spin-flip measurements in the proton inelastic scattering on 12C and giant resonance effects

    International Nuclear Information System (INIS)

    De Leo, R.; D'Erasmo, G.; Ferrero, F.; Pantaleo, A.; Pignanelli, M.

    1975-01-01

    Differential cross sections and spin-flip probabilities (SFP) for the inelastic scattering of protons, exciting the 2 + state at 4.43 MeV in 12 C, have been measured at several incident energies between 15.9 and 37.6 MeV. The changes in the shape of the SFP angular distributions are rather limited, while the absolute values show a pronounced increase, resonant like, in two energy regions centered at about 20 and 29 MeV. The second resonance reproduces very closely the energy dependence of the E2 giant quadrupole strength found in a previous experiment. The resonance at 20 MeV should correspond to a substructure of the E1 giant dipole resonance. (Auth.)

  7. Spin-State-Selective Excitation. Application for E.COSY-Type Measurement of JHHCoupling Constants

    Science.gov (United States)

    Meissner, Axel; Duus, Jens ø.; Sørensen, Ole Winneche

    1997-09-01

    A new pulse sequence element, spin-state-selective excitation (S3E), is introduced and combined with E.COSY-type techniques for measurement of1H-1HJcoupling constants. S3E edits the two resonances of a doublet prior to an evolution period of a multidimensional experiment and results in a subspectrum for each resonance. Due to this editing the large heteronuclear one-bond coupling constants normally exploited for separation of submultiplets in E.COSY-type experiments can be suppressed in experiments employing S3E. Hence there is a concomitant effective increase in resolution. Apart from pulse imperfections and relaxation during a delay (4J)-1S3E causes no loss of sensitivity in comparison to conventional experiments. Experimental confirmation is done using the protein RAP 17-97 (N-terminal domain of α2-macroglobulin receptor associated protein).

  8. Measurement of the Proton and Deuteron Spin Structure Function g1 in the Resonance Region

    International Nuclear Information System (INIS)

    Abe, K.; Akagi, T.; Perry Anthony; Antonov, R.; Arnold, R.G.; Todd Averett; Band, H.R.; Bauer, J.M.; Borel, H.; Peter Bosted; Vincent Breton; Button-Shafer, J.; Jian-Ping Chen; T.E. Chupp; J. Clendenin; C. Comptour; K.P. Coulter; G. Court; Donald Crabb; M. Daoudi; Donal Day; F.S. Dietrich; James Dunne; H. Dutz; R. Erbacher; J. Fellbaum; Andrew Feltham; Helene Fonvieille; Emil Frlez; D. Garvey; R. Gearhart; Javier Gomez; P. Grenier; Keith Griffioen; S. Hoeibraten; Emlyn Hughes; Charles Hyde-Wright; J.R. Johnson; D. Kawall; Andreas Klein; Sebastian Kuhn; M. Kuriki; Richard Lindgren; T.J. Liu; R.M. Lombard-Nelsen; Jacques Marroncle; Tomoyuki Maruyama; X.K. Maruyama; James Mccarthy; Werner Meyer; Zein-Eddine Meziani; Ralph Minehart; Joseph Mitchell; J. Morgenstern; Gerassimos Petratos; R. Pitthan; Dinko Pocanic; C. Prescott; R. Prepost; P. Raines; Brian Raue; D. Reyna; A. Rijllart; Yves Roblin; L. Rochester; Stephen Rock; Oscar Rondon-Aramayo; Ingo Sick; Lee Smith; Tim Smith; M. Spengos; F. Staley; P. Steiner; S. St. Lorant; L.M. Stuart; F. Suekane; Z.M. Szalata; Huabin Tang; Y. Terrien; Tracy Usher; Dieter Walz; Frank Wesselmann; J.L. White; K. Witte; C. Young; Brad Youngman; Haruo Yuta; G. Zapalac; Benedikt Zihlmann; Zimmermann, D.

    1997-01-01

    We have measured the proton and deuteron spin structure functions g 1 p and g 1 d in the region of the nucleon resonances for W 2 2 and Q 2 ≅ 0.5 and Q 2 ≅ 1.2 GeV 2 by inelastically scattering 9.7 GeV polarized electrons off polarized 15 NH 3 and 15 ND 3 targets. We observe significant structure in g 1 p in the resonance region. We have used the present results, together with the deep-inelastic data at higher W 2 , to extract Γ(Q 2 ) (triple b ond) ∫ 0 1 g 1 (x,Q 2 ) dx. This is the first information on the low-Q 2 evolution of Gamma toward the Gerasimov-Drell-Hearn limit at Q 2 = 0

  9. Pairwise correlations via quantum discord and its geometric measure in a four-qubit spin chain

    Directory of Open Access Journals (Sweden)

    Abdel-Baset A. Mohamed

    2013-04-01

    Full Text Available The dynamic of pairwise correlations, including quantum entanglement (QE and discord (QD with geometric measure of quantum discord (GMQD, are shown in the four-qubit Heisenberg XX spin chain. The results show that the effect of the entanglement degree of the initial state on the pairwise correlations is stronger for alternate qubits than it is for nearest-neighbor qubits. This parameter results in sudden death for QE, but it cannot do so for QD and GMQD. With different values for this entanglement parameter of the initial state, QD and GMQD differ and are sensitive for any change in this parameter. It is found that GMQD is more robust than both QD and QE to describe correlations with nonzero values, which offers a valuable resource for quantum computation.

  10. Measurement of the longitudinal deuteron spin-structure function in deep-inelastic scattering

    International Nuclear Information System (INIS)

    Bauer, J.M.

    1996-09-01

    Experiment E143 at SLAC performed deep-inelastic scattering measurements with polarized electrons incident on polarized protons and deuterons. The data for the beam energy of 29 GeV cover the kinematical range of x Bj > 0.03 and 1 2 2 . From these data, the spin-dependent structure functions g 1 were determined. This dissertation describes the experiment and its analysis and discusses the results. The measured integral of g 1 d over x from x = 0 to x = 1 is Γ 1 d = 0.046 ± 0.003 (stat)±0.004 (syst) at Q 2 = 3 GeV 2 and disagrees by more than three standard deviations with the prediction of the Ellis-Jaffe, sum rule. The data suggest that the quark contribution to the nucleon helicity is 0.35 ± 0.05. From the proton data of the same experiment, the integral over the proton spin-structure functional g 1 d was determined to be Γ 1 p = 0.127 ± 0.003(stat)±0.008(syst). By Combining the deuteron data with the proton data, the integral Γ 1 n was extracted as -0.027 ± 0.008 (stat)±0.010 (syst). The integral Γ 1 p - Γ 1 n is 0.154±0.010(stat) ±0.016 (syst) according to the E143 analysis. This result agrees with the important Bjorken sum rule of 0.171 ± 0.009 at Q 2 = 3 GeV 2 within less than one standard deviation. Furthermore, results of a separate analysis involving GLAP evolution equations are shown. Data were also collected for beam energies of 16.2 and 9.7 GeV, Results for g 1 at these energies are presented

  11. Muon spin rotation research program

    Science.gov (United States)

    Stronach, C. E.

    1980-01-01

    Data from cyclotron experiments and room temperature studies of dilute iron alloys and iron crystals under strain were analyzed. The Fe(Mo) data indicate that the effect upon the contact hyperfine field in Fe due to the introduction of Mo is considerably less than that expected from pure dilution, and the muon (+) are attracted to the Mo impurity sites. There is a significant change in the interstitial magnetic field with Nb concentration. The Fe(Ti) data, for which precession could clearly be observed early only at 468K and above, show that the Ti impurities are attractive to muon (+), and the magnitude of B(hf) is reduced far beyond the amount expected from pure dilution. Changes in the intersitital magnetic field with the introduction of Cr, W, Ge, and Si are also discussed. When strained to the elastic limit, the interstitial magnetic field in Fe crystals is reduced by 33 gauss, and the relaxation rate of the precession signal increases by 47%.

  12. Ultrasound measures of supraspinatus tendon thickness and acromiohumeral distance in rotator cuff tendinopathy are reliable.

    Science.gov (United States)

    McCreesh, Karen M; Anjum, Shakeel; Crotty, James M; Lewis, Jeremy S

    2016-01-01

    Rotator cuff (RC) tendinopathy has been widely ascribed to impingement of the supraspinatus tendon (SsT) in the subacromial space, measured as the acromiohumeral distance (AHD). Ultrasound (US) is suitable for measuring AHD and SsT thickness, but few reliability studies have been carried out in symptomatic populations, and interrater reliability is unconfirmed. This study aimed to examine the intrarater and interrater reliability of US measurements of AHD and SsT thickness in asymptomatic control subjects and patients with RC tendinopathy. Seventy participants were recruited and grouped as healthy controls (n = 25) and RC tendinopathy (n = 45). Repeated US measurements of AHD and SsT thickness were obtained by one rater in both groups and by two raters in the RC tendinopathy group. Intrarater and interrater reliability coefficients were excellent for both measurements (intraclass correlation > 0.92), but the intrarater reliability was superior. The minimal detectable change values in the symptomatic group were 0.7 mm for AHD and 0.6 mm for SsT thickness for a single experienced examiner; the values rose to 1.2 mm and 1.3 mm, respectively, for the pair of examiners. The results support the reliability of US for the measurement of AHD and SsT thickness in patients with symptomatic RC tendinopathy and provide minimal detectable change values for use in future research studies. © 2015 Wiley Periodicals, Inc.

  13. Extraction of the neutron electric form factor from measurements of inclusive double spin asymmetries

    Science.gov (United States)

    Sulkosky, V.; Jin, G.; Long, E.; Zhang, Y.-W.; Mihovilovic, M.; Kelleher, A.; Anderson, B.; Higinbotham, D. W.; Širca, S.; Allada, K.; Annand, J. R. M.; Averett, T.; Bertozzi, W.; Boeglin, W.; Bradshaw, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J.-P.; Chudakov, E.; De Leo, R.; Deng, X.; Deur, A.; Dutta, C.; El Fassi, L.; Flay, D.; Frullani, S.; Garibaldi, F.; Gao, H.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Gomez, J.; Hansen, J.-O.; Holmstrom, T.; Huang, J.; Ibrahim, H.; de Jager, C. W.; Jensen, E.; Jiang, X.; Jones, M.; Kang, H.; Katich, J.; Khanal, H. P.; King, P.; Korsch, W.; LeRose, J.; Lindgren, R.; Lu, H.-J.; Luo, W.; Markowitz, P.; Meekins, D.; Meziane, M.; Michaels, R.; Moffit, B.; Monaghan, P.; Muangma, N.; Nanda, S.; Norum, B. E.; Pan, K.; Parno, D.; Piasetzky, E.; Posik, M.; Punjabi, V.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Qui, X.; Riordan, S.; Saha, A.; Sawatzky, B.; Shabestari, M.; Shahinyan, A.; Shoenrock, B.; John, J. St.; Subedi, R.; Tobias, W. A.; Tireman, W.; Urciuoli, G. M.; Wang, D.; Wang, K.; Wang, Y.; Watson, J.; Wojtsekhowski, B.; Ye, Z.; Zhan, X.; Zhang, Y.; Zheng, X.; Zhao, B.; Zhu, L.; Jefferson Lab Hall A Collaboration

    2017-12-01

    Background: Measurements of the neutron charge form factor, GEn, are challenging because the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting GEn with different targets and techniques provides an important test of our handling of these effects. Purpose: The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of 1 (GeV/c ) 2 . This technique has very different systematic uncertainties than traditional exclusive measurements and thus serves as an independent check of whether nuclear effects have been taken into account correctly. Method: The inclusive quasielastic reaction 3He ⃗(e ⃗,e') was measured at Jefferson Laboratory. The neutron electric form factor, GEn, was extracted at Q2=0.98 (GeV/c ) 2 from ratios of electron-polarization asymmetries measured for two orthogonal target spin orientations. This Q2 is high enough that the sensitivity to GEn is not overwhelmed by the neutron magnetic contribution, and yet low enough that explicit neutron detection is not required to suppress pion production. Results: The neutron electric form factor, GEn, was determined to be 0.0414 ±0.0077 (stat)±0.0022 (syst) , providing the first high-precision inclusive extraction of the neutron's charge form factor. Conclusions: The use of the inclusive quasielastic 3He ⃗(e ⃗,e') with a four-momentum transfer near 1 (GeV/c ) 2 has been used to provide a unique measurement of GEn. This new result provides a systematically independent validation of the exclusive extraction technique results and implies that the nuclear corrections are understood. This is contrary to the proton form factor where asymmetry and differential cross section measurements have been shown to have large systematic differences.

  14. Temperature lidar measurements from 1 to 105 km altitude using resonance, Rayleigh, and Rotational Raman scattering

    Directory of Open Access Journals (Sweden)

    M. Alpers

    2004-01-01

    Full Text Available For the first time, three different temperature lidar methods are combined to obtain time-resolved complete temperature profiles with high altitude resolution over an altitude range from the planetary boundary layer up to the lower thermosphere (about 1–105 km. The Leibniz-Institute of Atmospheric Physics (IAP at Kühlungsborn, Germany (54° N, 12° E operates two lidar instruments, using three different temperature measurement methods, optimized for three altitude ranges: (1 Probing the spectral Doppler broadening of the potassium D1 resonance lines with a tunable narrow-band laser allows atmospheric temperature profiles to be determined at metal layer altitudes (80–105 km. (2 Between about 20 and 90 km, temperatures were calculated from Rayleigh backscattering by air molecules, where the upper start values for the calculation algorithm were taken from the potassium lidar results. Correction methods have been applied to account for, e.g. Rayleigh extinction or Mie scattering of aerosols below about 32 km. (3 At altitudes below about 25 km, backscattering in the Rotational Raman lines is strong enough to obtain temperatures by measuring the temperature dependent spectral shape of the Rotational Raman spectrum. This method works well down to about 1 km. The instrumental configurations of the IAP lidars were optimized for a 3–6 km overlap of the temperature profiles at the method transition altitudes. We present two night-long measurements with clear wave structures propagating from the lower stratosphere up to the lower thermosphere.

  15. Novel nuclear laser spectroscopy method using superfluid helium for measurement of spins and moments of exotic nuclei

    International Nuclear Information System (INIS)

    Furukawa, Takeshi; Wakui, Takashi; Yang, Xiaofei; Fujita, Tomomi; Imamura, Kei; Yamaguchi, Yasuhiro; Tetsuka, Hiroki; Tsutsui, Yoshiki; Mitsuya, Yosuke; Ichikawa, Yuichi; Ishibashi, Yoko; Yoshida, Naoki; Shirai, Hazuki; Ebara, Yuta; Hayasaka, Miki; Arai, Shino; Muramoto, Sosuke

    2013-01-01

    Highlights: • Development of a novel nuclear laser spectroscopy method using superfluid helium. • Observation of the Zeeman resonance with the 85 Rb beam introduced into helium. • Demonstration of deducing the nuclear spins from the observed resonance spectrum. -- Abstract: We have been developing a novel nuclear laser spectroscopy method “OROCHI” for determining spins and moments of exotic radioisotopes. In this method, we use superfluid helium as a stopping material of energetic radioisotope beams and then stopped radioisotope atoms are subjected to in situ laser spectroscopy in superfluid helium. To confirm the feasibility of this method for rare radioisotopes, we carried out a test experiment using a 85 Rb beam. In this experiment, we have successfully measured the Zeeman resonance signals from the 85 Rb atoms stopped in superfluid helium by laser-RF double resonance spectroscopy. This method is efficient for the measurement of spins and moments of more exotic nuclei

  16. Novel nuclear laser spectroscopy method using superfluid helium for measurement of spins and moments of exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, Takeshi, E-mail: takeshi@tmu.ac.jp [Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakui, Takashi [Cyclotron and Radioisotope Center, Tohoku University, 6-3 Aoba, Aramaki, Aoba, Sendai, Miyagi 980-8578 (Japan); Yang, Xiaofei [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); School of Physics, Peking University, Chengfu Road, Haidian District, Beijing 100871 (China); Fujita, Tomomi [Department of Physics, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Imamura, Kei; Yamaguchi, Yasuhiro [Department of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama, Kawasaki, Kanagawa 214-8571 (Japan); Tetsuka, Hiroki; Tsutsui, Yoshiki [Department of Physics, Tokyo Gakugei University, 4-1-1 Nukuikitamachi, Koganei, Tokyo 184-8501,Japan (Japan); Mitsuya, Yosuke [Department of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama, Kawasaki, Kanagawa 214-8571 (Japan); Ichikawa, Yuichi [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551 (Japan); Ishibashi, Yoko [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Yoshida, Naoki; Shirai, Hazuki [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551 (Japan); Ebara, Yuta; Hayasaka, Miki [Department of Physics, Tokyo Gakugei University, 4-1-1 Nukuikitamachi, Koganei, Tokyo 184-8501,Japan (Japan); Arai, Shino; Muramoto, Sosuke [Department of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama, Kawasaki, Kanagawa 214-8571 (Japan); and others

    2013-12-15

    Highlights: • Development of a novel nuclear laser spectroscopy method using superfluid helium. • Observation of the Zeeman resonance with the {sup 85}Rb beam introduced into helium. • Demonstration of deducing the nuclear spins from the observed resonance spectrum. -- Abstract: We have been developing a novel nuclear laser spectroscopy method “OROCHI” for determining spins and moments of exotic radioisotopes. In this method, we use superfluid helium as a stopping material of energetic radioisotope beams and then stopped radioisotope atoms are subjected to in situ laser spectroscopy in superfluid helium. To confirm the feasibility of this method for rare radioisotopes, we carried out a test experiment using a {sup 85}Rb beam. In this experiment, we have successfully measured the Zeeman resonance signals from the {sup 85}Rb atoms stopped in superfluid helium by laser-RF double resonance spectroscopy. This method is efficient for the measurement of spins and moments of more exotic nuclei.

  17. Measurement of double-spin asymmetries associated with deeply virtual Compton scattering on a transversely polarized hydrogen target

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Physikalisches Institut, Universitaet Giessen, 35392 Giessen (Germany); Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI 48109-1040 (United States); Akopov, N. [Yerevan Physics Institute, 375036 Yerevan (Armenia); Akopov, Z. [DESY, 22603 Hamburg (Germany); Aschenauer, E.C. [DESY, 15738 Zeuthen (Germany); Augustyniak, W. [Andrzej Soltan Institute for Nuclear Studies, 00-689 Warsaw (Poland); Avakian, R.; Avetissian, A. [Yerevan Physics Institute, 375036 Yerevan (Armenia); Avetisyan, E. [DESY, 22603 Hamburg (Germany); Belostotski, S. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad region 188300 (Russian Federation); Bianchi, N. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati (Italy); Blok, H.P. [National Institute for Subatomic Physics (Nikhef), 1009 DB Amsterdam (Netherlands); Department of Physics and Astronomy, VU University, 1081 HV Amsterdam (Netherlands); Borissov, A. [DESY, 22603 Hamburg (Germany); Bowles, J. [SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Brodski, I. [Physikalisches Institut, Universitaet Giessen, 35392 Giessen (Germany); Bryzgalov, V. [Institute for High Energy Physics, Protvino, Moscow region 142281 (Russian Federation); Burns, J. [SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Capiluppi, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara and Dipartimento di Fisica, Universita di Ferrara, 44100 Ferrara (Italy); Capitani, G.P. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati (Italy); Cisbani, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, gruppo Sanita and Istituto Superiore di Sanita, 00161 Rome (Italy); Ciullo, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara and Dipartimento di Fisica, Universita di Ferrara, 44100 Ferrara (Italy)

    2011-10-05

    Double-spin asymmetries in exclusive electroproduction of real photons from a transversely polarized hydrogen target are measured with respect to the product of target polarization with beam helicity and beam charge, and with respect to the product of target polarization with beam helicity alone. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe-Heitler process. They are related to the real part of the same combination of Compton form factors as that determining the previously published transverse target single-spin asymmetries through the imaginary part. The results for the double-spin asymmetries are found to be compatible with zero within the uncertainties of the measurement, and are not incompatible with the predictions of the only available GPD-based calculation.

  18. Image-based tracking system for vibration measurement of a rotating object using a laser scanning vibrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongkyu, E-mail: akein@gist.ac.kr; Khalil, Hossam; Jo, Youngjoon; Park, Kyihwan, E-mail: khpark@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, South Korea, 500-712 (Korea, Republic of)

    2016-06-28

    An image-based tracking system using laser scanning vibrometer is developed for vibration measurement of a rotating object. The proposed system unlike a conventional one can be used where the position or velocity sensor such as an encoder cannot be attached to an object. An image processing algorithm is introduced to detect a landmark and laser beam based on their colors. Then, through using feedback control system, the laser beam can track a rotating object.

  19. Image-based tracking system for vibration measurement of a rotating object using a laser scanning vibrometer

    International Nuclear Information System (INIS)

    Kim, Dongkyu; Khalil, Hossam; Jo, Youngjoon; Park, Kyihwan

    2016-01-01

    An image-based tracking system using laser scanning vibrometer is developed for vibration measurement of a rotating object. The proposed system unlike a conventional one can be used where the position or velocity sensor such as an encoder cannot be attached to an object. An image processing algorithm is introduced to detect a landmark and laser beam based on their colors. Then, through using feedback control system, the laser beam can track a rotating object.

  20. Daily measure of the constancy of rotation in the evaluation of geometric and dosimetric parameters of the tomotherapy

    International Nuclear Information System (INIS)

    Erzilbengoa, M.; Moral, S.; Bragado, L.; Guisasola, M. A.

    2011-01-01

    The daily test performance called ''Rotating Constancia'', based on the methodology developed by Balog ''Helical tomotherapy dynamic quality assurance'' (2006), has allowed us over these 2 years to assess the response to TomoTherapy machine parameters given dose, travel speed table offset of the same, position of the green lasers, field size, rotation time and energy index of the beam parameters can be measured without intensity modulation.

  1. Measurement of the strange quark contribution to the proton spin using neutral kaons at HERMES

    International Nuclear Information System (INIS)

    Lu, Shaojun

    2007-03-01

    This thesis reports a new ''isoscalar'' measurement of Δs + Δ anti s. Because strange quarks carry no isospin, the strange seas in the proton and neutron are identical. In the deuteron, an isoscalar target, the fragmentation process in DIS can be described without any assumptions regarding isospin dependent fragmentation. In the isoscalar extraction of Δs + Δ anti s only the spin asymmetry for K 0 s A K 0 s 1,d (x,Q 2 , z) and the inclusive asymmetry A 1,d (x,Q 2 ) are used. An accurate measurement of the total non-strange quark polarisation ΔQ = Δu + Δ anti u + Δd + Δ anti d comes directly from A 1,d (x,Q 2 ). The fragmentation functions needed for a leading order (LO) extraction of ΔS = Δs + Δ anti s are measured directly at HERMES kinematics using the same data. As a result of this analysis, the helicity densities for the strange quarks are consistent with zero with the experimental uncertainty over the measured x kinematic range. (orig.)

  2. Measurement of the strange quark contribution to the proton spin using neutral kaons at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shaojun

    2007-03-15

    This thesis reports a new ''isoscalar'' measurement of {delta}s + {delta} anti s. Because strange quarks carry no isospin, the strange seas in the proton and neutron are identical. In the deuteron, an isoscalar target, the fragmentation process in DIS can be described without any assumptions regarding isospin dependent fragmentation. In the isoscalar extraction of {delta}s + {delta} anti s only the spin asymmetry for K{sup 0}{sub s} A{sup K{sup 0}{sub s1,d}} (x,Q{sup 2}, z) and the inclusive asymmetry A{sub 1,d}(x,Q{sup 2}) are used. An accurate measurement of the total non-strange quark polarisation {delta}Q = {delta}u + {delta} anti u + {delta}d + {delta} anti d comes directly from A{sub 1,d}(x,Q{sup 2}). The fragmentation functions needed for a leading order (LO) extraction of {delta}S = {delta}s + {delta} anti s are measured directly at HERMES kinematics using the same data. As a result of this analysis, the helicity densities for the strange quarks are consistent with zero with the experimental uncertainty over the measured x kinematic range. (orig.)

  3. Demonstration of a Sensitive Method to Measure Nuclear-Spin-Dependent Parity Violation

    Science.gov (United States)

    Altuntaş, Emine; Ammon, Jeffrey; Cahn, Sidney B.; DeMille, David

    2018-04-01

    Nuclear-spin-dependent parity violation (NSD-PV) effects in atoms and molecules arise from Z0 boson exchange between electrons and the nucleus, and from the magnetic interaction between electrons and the parity-violating nuclear anapole moment. We demonstrate measurements of NSD-PV that use an enhancement of the effect in diatomic molecules, here using the test system 138Ba 19. Our sensitivity surpasses that of any previous atomic parity violation measurement. We show that systematic errors can be suppressed to at least the level of the present statistical sensitivity. We measure the matrix element W of the NSD-PV interaction with total uncertainty δ W /(2 π )<0.7 Hz , for each of two configurations where W must have different signs. This sensitivity would be sufficient to measure NSD-PV effects of the size anticipated across a wide range of nuclei including 137Ba in 137BaF, where |W |/(2 π )≈5 Hz is expected.

  4. Visualizing molecular unidirectional rotation

    Science.gov (United States)

    Lin, Kang; Song, Qiying; Gong, Xiaochun; Ji, Qinying; Pan, Haifeng; Ding, Jingxin; Zeng, Heping; Wu, Jian

    2015-07-01

    We directly visualize the spatiotemporal evolution of a unidirectional rotating molecular rotational wave packet. Excited by two time-delayed polarization-skewed ultrashort laser pulses, the cigar- or disk-shaped rotational wave packet is impulsively kicked to unidirectionally rotate as a quantum rotor which afterwards disperses and exhibits field-free revivals. The rich dynamics can be coherently controlled by varying the timing or polarization of the excitation laser pulses. The numerical simulations very well reproduce the experimental observations and intuitively revivify the thoroughgoing evolution of the molecular rotational wave packet of unidirectional spin.

  5. Spin Transport in Bose Gases

    NARCIS (Netherlands)

    van Driel, H.J.

    2012-01-01

    In this Thesis, we show that in a rotating two-component Bose mixture, the spin drag between the two different spin species shows a Hall effect. This spin drag Hall effect can be observed experimentally by studying the out-of-phase dipole mode of the mixture. We determine the damping of this mode

  6. A Precision Measurement of the Spin Structure of the Proton at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Erbacher, Robin D

    1999-09-22

    E143 at SLAC Endstation A performed deep-inelastic scattering measurements of polarized electrons from polarized protons and deuterons within cryogenic {sup 15}NH{sub 3} and {sup 15}ND{sub 3}, respectively. Data were taken at incident energies of 29.1, 16.2 and 9.7 GeV, and covered the kinematical range x > 0:03 and 0:3 < Q{sup 2} < 12 (GeV/c){sup 2}. The scattered electrons were detected by two spectrometers at angles of 4.5{sup o} and 7.0{sup o}. From these data, the spin-dependent structure functions g{sub 1}{sup p}(x; Q{sup 2}) and g{sub 1}{sup d}(x; Q{sup 2}) were determined. This dissertation describes the experiment, with emphasis on the results on the proton spin structure. The integral of g{sub 1} over the range 0 < x < 1 was found to be {Gamma}{sub 1}{sup p} = 0.130 {+-} 0.003 {+-} 0.008 for the proton and {Gamma}{sub 1}{sup d} = 0.044 {+-} 0.003 {+-} 0.004 for the deuteron. Both values are in agreement with world data, and violate the Ellis-Jaffe sum rule by more than 3 standard deviations. The neutron structure function was obtained by combining proton and deuteron results, giving {Gamma}{sub 1}{sup n} = [0.035 {+-} 0.007 {+-} 0.010]. From this the integral {Gamma}{sub 1}{sup p}-{Gamma}{sub 1}{sup n} followed, yielding 0.165 {+-} 0.009 {+-} 0.016 at Q{sup 2} = 3 (GeV/c){sup 2}, in agreement with the Bjorken sum rule to within one standard deviation. The Q{sup 2}-dependence of the ratio g{sub 1}/F{sub 1} was determined to be small for Q{sup 2} > 1 (GeV/c){sup 2}, validating the assumption of no Q{sup 2}-dependence used in obtaining the integrals. A small rise with increasing Q{sup 2} was seen in the ratio for Q{sup 2} < 1 (GeV/c){sup 2}, however. The total quark contribution to the spin was found to be {Delta}q = 0.28 {+-} 0.09 for the proton, and {Delta}q = 0.32 {+-} 0.05 for the deuteron. Furthermore, a large negative spin contribution from the strange sea quarks was measured for both nucleons, giving {Delta}s = 0.10 {+-} 0.03 and {Delta}s = -0

  7. Research on Measurement Accuracy of Laser Tracking System Based on Spherical Mirror with Rotation Errors of Gimbal Mount Axes

    Science.gov (United States)

    Shi, Zhaoyao; Song, Huixu; Chen, Hongfang; Sun, Yanqiang

    2018-02-01

    This paper presents a novel experimental approach for confirming that spherical mirror of a laser tracking system can reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy. By simplifying the optical system model of laser tracking system based on spherical mirror, we can easily extract the laser ranging measurement error caused by rotation errors of gimbal mount axes with the positions of spherical mirror, biconvex lens, cat's eye reflector, and measuring beam. The motions of polarization beam splitter and biconvex lens along the optical axis and vertical direction of optical axis are driven by error motions of gimbal mount axes. In order to simplify the experimental process, the motion of biconvex lens is substituted by the motion of spherical mirror according to the principle of relative motion. The laser ranging measurement error caused by the rotation errors of gimbal mount axes could be recorded in the readings of laser interferometer. The experimental results showed that the laser ranging measurement error caused by rotation errors was less than 0.1 μm if radial error motion and axial error motion were within ±10 μm. The experimental method simplified the experimental procedure and the spherical mirror could reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy of the laser tracking system.

  8. Anomalously large spin susceptibility enhancement in n-doped CdMnTe quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Ben Cheikh, Z. [Laboratoire Charles Coulomb, UMR 5221, Département Semi-conducteurs, Matériaux et Capteurs, Université Montpellier 2, France and Laboratoire de Physique des Matériaux: Structures et Propriétés, Faculté (Tunisia); Cronenberger, S.; Vladimirova, M.; Scalbert, D. [Laboratoire Charles Coulomb, UMR 5221, Departement Semi-conducteurs, Materiaux et Capteurs, Universite Montpellier 2 (France); Boujdaria, K. [Laboratoire de Physique des Matériaux: Structures et Propriétés, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna (Tunisia); Baboux, F.; Perez, F. [Institut des NanoSciences de Paris, CNRS/Université Paris 6, 4 place Jussieu, F-75005 Paris (France); Wojtowicz, T.; Karczewski, G. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland)

    2013-12-04

    We report on time-resolved Kerr rotation (TRKR) experiments done on n-doped CdMnTe quantum wells (QWs), in the regime where strong coupling between the electron and the Mn spin-flip excitations shows up. It has been proposed previously to deduce the 2D electron gas spin susceptibility from the coupling energy between these spin excitations. Here we measure the coupling energy on a high mobility sample down to very low excitation density, and compare the results with spin-flip Raman scattering (SFRS) on the same sample. The electron spin polarizations measured by TRKR and SFRS are found in relatively good agreement. However the spin susceptibility measured by TRKR exceeds systematically the values predicted by many-body theory. This could be an indication that the two-oscillator model used to describe mixed electron-Mn spin excitations needs to be improved.

  9. Remote measurement of atmospheric temperature profiles in clouds with rotational Raman lidar; Fernmessung atmosphaerischer Temperaturprofile in Wolken mit Rotations-Raman-Lidar

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physikalische und Chemische Analytik

    2000-07-01

    The development of a lidar receiver for remote measurements of atmospheric temperature profiles with the rotational Raman method is described. By a new receiver concept, this instrument allowed for the first time remote temperature measurements without any perturbation by the presence of clouds up to a backscatter ratio of 45. In addition, high efficiency of the spectral separation of atmospheric backscatter signals leads to improved measurement resolution: the minimum integration time needed for a statistical uncertainty < {+-}1 K at, e.g., 10 km height and 960 m height resolution is only 5 minutes. The measurement range extends to over 45 km altitude. Results of field campaigns obtained with the instrument are presented and discussed. In winter 1997/98, the instrument was transferred with the GKSS Raman lidar to Esrange (67.9 N, 21.1 E) in northern Sweden, where pioneering remote measurements of local temperatures in orographically induced polar stratospheric clouds could be carried out. (orig.)

  10. Pyrometer for measurement of surface temperature distribution on a rotating turbine blade.

    Science.gov (United States)

    Buchele, D. R.; Lesco, D. J.

    1972-01-01

    A conceptual optical method and some test results are presented for measuring the surface temperature distribution on one of the rotating turbine blades with a surface resolution of 0.05 cm spot diameter at a tip speed of 400 m/sec. The blade is scanned line-by-line by a fixed optical system. During each line-scan, the detector analog output signal is converted to 200 consecutive digital values that are temporarily stored in a high-speed buffer memory and then transferred at a slower rate to a computer for processing. The signal-to-noise ratio of the silicon avalanche detector is large enough to obtain an accuracy of 1% at 1050 K blade temperature. By averaging 25 scans of the same line the same accuracy can be obtained at 900 K.

  11. Spin tracking for a deuteron EDM storage ring

    Science.gov (United States)

    Skawran, A.; Lehrach, A.

    2017-07-01

    The aim of the Jülich Electric Dipole moment Investigations (JEDI) collaboration is the measurement of the Electric Dipole Moment (EDM) of charged particles like protons or deuterons. There are two possible concepts under consideration for the realization of EDM measurement with deuterons; the Frozen Spin (FS) and Quasi-Frozen Spin (QFS) method. Both approaches are discussed and compared in this paper. Detailed spin- and beam dynamics simulations are performed to investigate the effect of various misalignments of ring elements and systematic effects. Furthermore, the utilization of counter rotating beams is studied and checked for its validity.

  12. A Precision Measurement of the Spin Structure Function G(2)(P)

    Energy Technology Data Exchange (ETDEWEB)

    Benmouna, N

    2004-01-05

    The spin structure function g{sub 2}(x,Q{sup 2}) and the virtual photon asymmetry A{sub 2}(x,Q{sup 2}) were measured for the proton using deep inelastic scattering. The experiment was conducted at the Stanford Linear Accelerator Center (SLAC), where longitudinally polarized electrons at 29.1 and 32.3 GeV were scattered from a transversely polarized NH{sub 3} target. Large data sets were accumulated using three independent spectrometers covering a kinematic range 0.02 {le} x {le} 0.8 and 1 {le} Q{sup 2} {le} 20 (GeV/c){sup 2}. This new data is the first data precise enough to distinguish between current models for the proton. The structure function g{sub 2}{sup p} was found to be reasonably consistent with the twist-2 Wandzura-Wilczek calculation. The Q{sup 2} dependence of g{sub 2} approximately follows the Q{sup 2} dependence of g{sub 2}{sup WW}, although the data are not precise enough to rule out no Q{sup 2} dependence. The absolute value for A{sub 2}{sup p} was found to be significantly smaller than the Soffer limit over the measured range. The virtual photon asymmetry A{sub 2} was also found to be inconsistent with zero over much of the measured range.

  13. Measuring nuclear-spin-dependent parity violation with molecules: Experimental methods and analysis of systematic errors

    Science.gov (United States)

    Altuntaş, Emine; Ammon, Jeffrey; Cahn, Sidney B.; DeMille, David

    2018-04-01

    Nuclear-spin-dependent parity violation (NSD-PV) effects in atoms and molecules arise from Z0 boson exchange between electrons and the nucleus and from the magnetic interaction between electrons and the parity-violating nuclear anapole moment. It has been proposed to study NSD-PV effects using an enhancement of the observable effect in diatomic molecules [D. DeMille et al., Phys. Rev. Lett. 100, 023003 (2008), 10.1103/PhysRevLett.100.023003]. Here we demonstrate highly sensitive measurements of this type, using the test system 138Ba19F. We show that systematic errors associated with our technique can be suppressed to at least the level of the present statistical sensitivity. With ˜170 h of data, we measure the matrix element W of the NSD-PV interaction with uncertainty δ W /(2 π )<0.7 Hz for each of two configurations where W must have different signs. This sensitivity would be sufficient to measure NSD-PV effects of the size anticipated across a wide range of nuclei.

  14. Spin density measurement of water-bridged Co-dimer using polarized neutrons

    DEFF Research Database (Denmark)

    Damgaard-Møller, Emil; Overgaard, Jacob; Chilton, Nick

    present an experimentally determined spin density using polarized neutron diffraction in a simple water-bridged cobalt dimer [Co2(H2O)(piv)4(Hpiv)2(py)2] which is known to have a small ferromagnetic coupling between the spin centers. Visualizing the SDD could get us one step further in understanding...

  15. The comparison of aneurysmal necks measured on three dimensional reconstruction images of rotational DSA and those of traditional DSA

    International Nuclear Information System (INIS)

    Wu Chunhong; Chen Zuoquan; Gu Binxian; Zhang Guiyun

    2006-01-01

    Objective: To evaluate the value of three dimensional reconstruction images of rotational DSA on measuring aneurysmal necks and make a comparison with traditional DSA so as to provide more abundant and accurate information for the embolization of aneurysm. Methods: A comparison was made between the measurement of aneurismal necks from 14 cases with traditional DSA examination and a measurement made on three dimensional reconstruction images of the same patients. Results: There was a difference shown in the measurement of the aneurysmal necks between three dimensional reconstruction images of rotational DSA and those of traditional DSA, outcoming with more angles and data on three dimensional reconstruction images. Conclusions: There are more angles of aneurysmal neck can be shown on rotational 3D DSA especially for the demonstration of the largest aneurysmal neck with a directional value for the intervention. (authors)

  16. Effect of instantaneous rotational speed on the analysis of measured diesel engine cylinder pressure data

    International Nuclear Information System (INIS)

    Antonopoulos, Antonis K.; Hountalas, Dimitrios T.

    2012-01-01

    Highlights: ► The effect of in-cycle speed fluctuation on cylinder pressure measurement is investigated. ► A phasing error is introduced when sampling cylinder pressure at constant time intervals. ► The phasing error increases with the increase of engine load and decrease of engine speed. ► Measurement using constant sampling rate affects estimation of HRR, ignition angle etc. - Abstract: Diesel engine cylinder pressure measurements are widely used in field and lab applications to support among other control, monitoring and diagnostic applications. There are two methods to measure cylinder pressure, the use of a crank angle encoder, which guarantees pressure samples at fixed crank angles, and the use of constant time sampling rate. The last is frequently used due to its simplicity or because of practical restrictions. However, in order to perform thermodynamic calculations it is necessary to attribute a crank angle value to each measured pressure value. But if the in-cycle rotational speed fluctuates and this is neglected, an error will result in the values derived from the processing of the measured cylinder pressure. For this reason in the present work an experimental investigation is conducted on a single cylinder diesel test engine to identify the aforementioned problem. During the tests cylinder pressure and instantaneous speed were recorded using an accurate crank angle reference. These where then used to simulate the measurement of cylinder pressure digitized using a fixed time step. The comparison of the two cylinder pressure traces and the thermodynamic parameters derived from them, reveals the introduction of an error which depends on engine load and speed.

  17. Summary of measurements of the spin dependence in NN interactions from 2 to 12 GeV/c

    International Nuclear Information System (INIS)

    Rust, D.R.

    1975-01-01

    The status of experimental measurements of the spin dependence in NN interactions from 2 to 12 GeV/c as of June 1975 is summarized. Older data have been left out if more accurate or more complete results are available

  18. Spin cutoff parameters for 28Si, 29Si, and 30P: Comparison of measurements with spectral distribution calculations

    International Nuclear Information System (INIS)

    Grimes, S.M.; Poppe, C.H.; Wong, C.; Dalton, B.J.

    1978-01-01

    Spin cutoff parameters for 28 Si, 29 Si, and 30 P have been deduced from angular distribution measurements for (α,n) reactions on 25 Mg, 26 Mg, and 27 Al. Calculations of the spin cutoff parameter which include the effect of two body interactions are made using the theory of spectral distributions. The results obtained by dividing the space into subspaces and expanding the strength distribution of each in a Gaussian are found to be more reliable than calculating a single Gaussian for the entire space. The comparisons in this study indicate a need for the inclusion of higher moments of the Hamiltonian in the level density expansion

  19. A proposed measurement of optical orbital and spin angular momentum and its implications for photon angular momentum

    Science.gov (United States)

    Leader, Elliot

    2018-04-01

    The expression for the total angular momentum carried by a laser optical vortex beam, splits, in the paraxial approximation, into two terms which seem to represent orbital and spin angular momentum respectively. There are, however, two very different competing versions of the formula for the spin angular momentum, one based on the use of the Poynting vector, as in classical electrodynamics, the other related to the canonical expression for the angular momentum which occurs in Quantum Electrodynamics. I analyze the possibility that a sufficiently sensitive optical measurement could decide which of these corresponds to the actual physical angular momentum carried by the beam.

  20. Optical rotation measurements in process control and engineering research in foods

    Energy Technology Data Exchange (ETDEWEB)

    Huerta-Ruelas, J.; Lopez-Echevarria, D.; Mendoza-Sanchez, P.; Kongraksawech, T.; Velazquez, G.; Torres, J. A.

    2008-07-01

    A system to measure optical rotation (OR) and transmitted light (TL) was built and tested by the Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada (CICATA, Mexico). A similar system was built and tested by the Food Process Engineering Group (FPEG) at Oregon State University. OR and TL values, as a function of time and sample temperature, were recorded by a data acquisition system. Sucrose (1% w/v) and distilled water were used to calibrate both instruments while sucrose solutions were used to determine sensitivity, linearity and stability. The OR of sucrose solutions was measured with less than 3% (0.03 to 20 g/100 mL) and 2% error (0.01 to 20 g/100 mL) for the FPEG and CICATA system, respectively. The instrument setup was tested at CICATA by monitoring sucrose hydrolysis and by comparing initial and final OR with published reference values. Application examples tested by FPEG were the characterization of hard candies and the fermentation monitoring of tepache, a pre hispanic alcoholic beverage consumed in Mexico and some Latin American countries. These tests confirmed the instrument versatility and the advantages of building modular units with light sources and electronic components available today at low cost. This work showed, using specific applications, that modular units for well-established optical measurements such as OR and TL could have additional applications in food process control and engineering research. (Author) 27 refs.

  1. Measuring the quark contribution to the proton spin through νp → νp

    International Nuclear Information System (INIS)

    Louis, W.C.

    1991-01-01

    The LSND (Liquid Scintillator Neutrino Detector) experiment will be performed at LAMPF in the next several years. The main goal of the experiment is to search for ν μ -ν e oscillations with high sensitivity; however, an increasingly important by-product of this search is to measure νp → νp elastic scattering and determine the strange quark contribution, Δs, to the spin of the proton. With the 800-MeV proton energy of LAMPF, neutrinos are produced from pion decay-in-flight with an average energy of about 150 MeV. This energy is sufficiently high so that the νp → νp cross section is large and is sufficiently low so that the low Q 2 approximation (Q 2 much-lt m p 2 ) is valid and the cross section can be expressed in a simple form dependent upon Δs as the only unknown. LAMPF with its 1-mA proton intensity is, therefore, an ideal accelerator to perform this measurement. 12 refs., 7 figs., 2 tabs

  2. Measurement of a hyperfine-induced spin-exchange frequency shift in atomic hydrogen

    International Nuclear Information System (INIS)

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

    1992-01-01

    We have measured a hyperfine-induced spin-exchange frequency shift in the atomic-hydrogen ground-state hyperfine transition. A recent quantum-mechanical treatment of low-energy hydrogen-hydrogen scattering by Koelman et al. [Phys. Rev. A 38, 3535 (1988)] predicts such frequency shifts to become large at low temperature, and to affect the performance of atomic clocks such as the cryogenic hydrogen maser. The experiment reported here was performed with a hydrogen maser operating near room temperature, where the reported hyperfine effects are predicted to be small, but measurable. Using an adiabatic fast passage (AFP) technique to vary the incoming atomic population in the masing states from approximately 100% (AFP on) to 50% (AFP off), we determined the change in the dimensionless hyperfine-induced frequency-shift parameter Ω to be Ω on -Ω off =5.38 (1.06)x10 -4 . The theoretical prediction at this temperature is Ω on -Ω off =-0.76x10 -4 to -1.12x10 -4 , for the range of masing-state populations used in the present experiment. We review the relevant theory, report our experimental method and results, and discuss possible reasons for the discrepancy between experiment and theory

  3. Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetry A2

    Energy Technology Data Exchange (ETDEWEB)

    Perry Anthony; R.G. Arnold; Todd Averett; H.R. Band; M.C. Berisso; H. Borel; Peter Bosted; Stephen Bueltmann; M. Buenerd; T. Chupp; Steve Churchwell; G.R. Court; Donald Crabb; Donal Day; Piotr Decowski; P. DePietro; Robin D. Erbacher; R. Erickson; Andrew Feltham; Helene Fonvieille; Emil Frlez; R. Gearhart; V. Ghazikhanian; Javier Gomez; Keith Griffioen; C. Harris; M.A. Houlden; E.W. Hughes; Charles Hyde-Wright; G. Igo; Sebastien Incerti; John Jensen; J.K. Johnson; Paul King; Yu.G. Kolomensky; Sebastian Kuhn; Richard Lindgren; R.M. Lombard-Nelsen; Jacques Marroncle; James Mccarthy; Paul McKee; W. Meyer; Gregory Mitchell; Joseph Mitchell; Michael Olson; S. Penttila; Gerald Peterson; Gerassimos Petratos; R. Pitthan; Dinko Pocanic; R. Prepost; C. Prescott; Liming Qin; Brian Raue; D. Reyna; L.S. Rochester; Stephen Rock; Oscar Rondon-Aramayo; Franck Sabatie; Ingo Sick; T. Smith; L. Sorrell; F. Staley; S. St. Lorant; L.M. Stuart; Z. Szalata; Y. Terrien; William Tobias; Luminita Todor; T. Toole; S. Trentalange; Dieter Walz; Robert Welsh; Frank Wesselmann; T.R. Wright; C.C. Young; Markus Zeier; Hong Guo Zhu; Benedikt Zihlmann

    1999-07-15

    We have measured the spin structure functions g{sub 2}{sup p} and g{sub 2}{sup d} and the virtual photon asymmetries A{sub 2}{sup p} and A{sub 2}{sup d} over the kinematic range 0.02 < x < 0.8 and 1.0 < Q{sup 2} {le} 30(GeV/c){sup 2} by scattering 38.8 GeV longitudinally polarized electrons from transversely polarized NH{sub 3} and {sup 6}LiD targets.The absolute value of A{sub 2} is significantly smaller than the {radical}R positivity limit over the measured range, while g{sub 2} is consistent with the twist-2 Wandzura-Wilczek calculation. We obtain results for the twist-3 reduced matrix elements d{sub 2}{sup p}, d{sub 2}{sup d} and d{sub 2}{sup n}. The Burkhardt-Cottingham sum rule integral (g{sub 2}(x)dx) is reported for the range 0.02 {le} x {le} 0.8.

  4. Muon spin rotation study of magnetism and superconductivity in Ba(Fe1-xCox)2As2 single crystals

    OpenAIRE

    Bernhard, C.; Wang, C. N.; Nuccio, L.; Schulz, L.; Zaharko, O.; Larsen, Jacob; Aristizabal, C.; Willis, M.; Drew, A. J.; Varma, G. D.; Wolf, T.; Niedermayer, Ch.

    2012-01-01

    Using muon spin rotation (μSR) we investigated the magnetic and superconducting properties of a series of Ba(Fe1−xCox)2As2 single crystals with 0 ≤x ≤0.15. Our study details how the antiferromagnetic order is suppressed upon Co substitution and how it coexists with superconductivity. In the nonsuperconducting samples at 0

  5. S3 HMBC: Spin-State-Selective HMBC for accurate measurement of homonuclear coupling constants. Application to strychnine yielding thirteen hitherto unreported JHH

    DEFF Research Database (Denmark)

    Kjaerulff, Louise; Benie, Andrew J.; Hoeck, Casper

    2016-01-01

    A novel method, Spin-State-Selective (S3) HMBC, for accurate measurement of homonuclear coupling constants is introduced. As characteristic for S3 techniques, S3 HMBC yields independent subspectra corresponding to particular passive spin states and thus allows determination of coupling constants ...... are demonstrated by an application to strychnine where thirteen JHH coupling constants not previously reported could be measured....

  6. Incomplete fusion reactions in 16O+159Tb system: Spin distribution measurements

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2015-01-01

    Full Text Available In order to explore the reaction modes on the basis of their entry state spin population, an experiment has been done by employing particle-γ coincidence technique carried out at the Inter University Accelerator Centre, New Delhi. The preliminary analysis conclusively demonstrates, spin distribution for some reaction products populated via complete and/or incomplete fusion of 16O with 159Tb system found to be distinctly different. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states.

  7. Longitudinal Field Muon Spin Rotation Study of Magnetic Freezing in Fe Rich FeSe0.25Te0.75

    Science.gov (United States)

    MacFarlane, W. A.; Ofer, O.; Chow, K. H.; Hossain, M. D.; Parolin, T. J.; Saadaoui, H.; Song, Q.; Wang, D.; Arseneau, D. J.; Hitti, B.; Yeh, K.-W.; Ke, C.-T.; Wu, M.-K.

    We study the freezing of magnetic fluctuations in an Fe rich sample of the "11" iron-based superconductor using longitudinal field muon spin relaxation. The magnetic relaxation rate peaks at 15 K indicating spin glass freezing that nearly coincides with the superconducting transition of the corresponding Fe stoichiometric phase. At this temperature, the magnetic field dependence of the relaxation indicates slow magnetic fluctuations on the nanosecond timescale.

  8. An angle-dependent estimation of CT x-ray spectrum from rotational transmission measurements

    International Nuclear Information System (INIS)

    Lin, Yuan; Samei, Ehsan; Ramirez-Giraldo, Juan Carlos; Gauthier, Daniel J.; Stierstorfer, Karl

    2014-01-01

    Purpose: Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational procedures, and are often limited to the spectrum corresponding to the center of rotation. In order to address these limitations, the authors propose an angle-dependent estimation technique, where the incident spectra across a wide range of angular trajectories can be estimated accurately with only a single phantom and a single axial scan in the absence of the knowledge of the bowtie filter. Methods: The proposed technique uses a uniform cylindrical phantom, made of ultra-high-molecular-weight polyethylene and positioned in an off-centered geometry. The projection data acquired with an axial scan have a twofold purpose. First, they serve as a reflection of the transmission measurements across different angular trajectories. Second, they are used to reconstruct the cross sectional image of the phantom, which is then utilized to compute the intersection length of each transmission measurement. With each CT detector element recording a range of transmission measurements for a single angular trajectory, the spectrum is estimated for that trajectory. A data conditioning procedure is used to combine information from hundreds of collected transmission measurements to accelerate the estimation speed, to reduce noise, and to improve estimation stability. The proposed spectral estimation technique was validated experimentally using a clinical scanner (Somatom Definition Flash, Siemens Healthcare, Germany) with spectra provided by the manufacturer serving as the comparison standard. Results obtained with the proposed technique were compared against those obtained from a second conventional transmission measurement technique with two materials (i.e., Cu and Al). After validation, the proposed technique was applied to measure

  9. O2 rotational temperature measurements in an atmospheric air microdischarge by radar resonance-enhanced multiphoton ionization

    International Nuclear Information System (INIS)

    Sawyer, Jordan; Wu, Yue; Zhang, Zhili; Adams, Steven F.

    2013-01-01

    Nonintrusive spatially resolved rotational temperature measurements in an atmospheric air microdischarge are presented. The measurements were based on coherent microwave Rayleigh scattering (Radar) from resonance-enhanced multiphoton ionization of molecular oxygen. The open air DC microdischarge source operated in a stable “normal-glow” mode and pin-to-pin electrodes spaced 1.3 mm apart. The second harmonic of a tunable dye laser beam was focused between the two electrodes and scanned between 286 and 288 nm. Coherent microwave Rayleigh scattering was used to collect the two-photon rotational spectra of O 2 at C 3 Π(v = 2)←X 3 Σ(v′ = 0) transitions. The Boltzmann plots from analyses of the O 2 rotational lines determined local rotational temperatures at various axial locations between the electrodes. The molecular oxygen rotational temperature varied from ∼1150 K to ∼1350 K within the discharge area. The measurements had an accuracy of ∼±50 K.

  10. O2 rotational temperature measurements in an atmospheric air microdischarge by radar resonance-enhanced multiphoton ionization

    Science.gov (United States)

    Sawyer, Jordan; Wu, Yue; Zhang, Zhili; Adams, Steven F.

    2013-06-01

    Nonintrusive spatially resolved rotational temperature measurements in an atmospheric air microdischarge are presented. The measurements were based on coherent microwave Rayleigh scattering (Radar) from resonance-enhanced multiphoton ionization of molecular oxygen. The open air DC microdischarge source operated in a stable "normal-glow" mode and pin-to-pin electrodes spaced 1.3 mm apart. The second harmonic of a tunable dye laser beam was focused between the two electrodes and scanned between 286 and 288 nm. Coherent microwave Rayleigh scattering was used to collect the two-photon rotational spectra of O2 at C3Π(v = 2)←X3Σ(v' = 0) transitions. The Boltzmann plots from analyses of the O2 rotational lines determined local rotational temperatures at various axial locations between the electrodes. The molecular oxygen rotational temperature varied from ˜1150 K to ˜1350 K within the discharge area. The measurements had an accuracy of ˜±50 K.

  11. Event-based motion correction for PET transmission measurements with a rotating point source

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Meikle, Steven R; Fulton, Roger

    2011-01-01

    Accurate attenuation correction is important for quantitative positron emission tomography (PET) studies. When performing transmission measurements using an external rotating radioactive source, object motion during the transmission scan can distort the attenuation correction factors computed as the ratio of the blank to transmission counts, and cause errors and artefacts in reconstructed PET images. In this paper we report a compensation method for rigid body motion during PET transmission measurements, in which list mode transmission data are motion corrected event-by-event, based on known motion, to ensure that all events which traverse the same path through the object are recorded on a common line of response (LOR). As a result, the motion-corrected transmission LOR may record a combination of events originally detected on different LORs. To ensure that the corresponding blank LOR records events from the same combination of contributing LORs, the list mode blank data are spatially transformed event-by-event based on the same motion information. The number of counts recorded on the resulting blank LOR is then equivalent to the number of counts that would have been recorded on the corresponding motion-corrected transmission LOR in the absence of any attenuating object. The proposed method has been verified in phantom studies with both stepwise movements and continuous motion. We found that attenuation maps derived from motion-corrected transmission and blank data agree well with those of the stationary phantom and are significantly better than uncorrected attenuation data.

  12. Beam steering and coordinate system rotation improves accuracy of ultrasonic measurements of tissue displacement vector and lateral displacement

    Directory of Open Access Journals (Sweden)

    Sumi C

    2011-11-01

    Full Text Available Chikayoshi Sumi1,2, Kento Ichimaru2, Yusuke Shinozuka21Department of Information and Communication Science, 2Department of Electrical and Electronics Engineering, Faculty of Science and Technology, Sophia University, Kioi-cho, Chiyoda-ku, Tokyo, JapanAbstract: With the proper use of beam steering and apodization, a higher resolution lateral echo image is obtained than with conventional imaging. This is achieved by superimposing crossed, steered beams, which is referred to as “lateral modulation” (LM. This type of beamforming achieves almost the same accuracy in lateral displacement measurements as in axial displacement measurements, ie, displacement vector measurements. The steering angle (ASTA can also be used instead of LM, which uses only beams with a steering angle. In this report, the accuracy of the displacement vectors and lateral displacement measurements for LM and ASTA were evaluated using simulations and agar phantom experiments. The parameters used were direction of a displacement vector, steering angles, and rotation angle for the coordinate system. Changes in the steering angle and rotation angle of the coordinate system permit control of frequencies in the respective directions of the coordinate axes. As shown, when performing a simple ASTA for displacement vector measurement, a spectra frequency division should be performed using a previously developed multidimensional autocorrelation or Doppler method instead of block-matching methods. In this version of ASTA, the combination of nonsteering and rotation of the coordinate system is also effective, because the lateral bandwidth does not decrease. In such a case, transmission of a laterally wide wave will also be effective, particularly for three-dimensional measurement/imaging using a two-dimensional array transducer. ASTA can also be used for accurate lateral displacement measurements. Although a proper beam steering and/or a proper coordinate rotation improves the

  13. Cross-Correlated Relaxation of Dipolar Coupling and Chemical-Shift Anisotropy in Magic-Angle Spinning R1ρ NMR Measurements: Application to Protein Backbone Dynamics Measurements

    Science.gov (United States)

    Kurauskas, Vilius; Weber, Emmanuelle; Hessel, Audrey; Ayala, Isabel; Marion, Dominique; Schanda, Paul

    2016-01-01

    Transverse relaxation rate measurements in MAS solid-state NMR provide information about molecular motions occurring on nanoseconds-to-milliseconds (ns-ms) time scales. The measurement of heteronuclear (13C, 15N) relaxation rate constants in the presence of a spin-lock radio-frequency field (R1ρ relaxation) provides access to such motions, and an increasing number of studies involving R1ρ relaxation in proteins has been reported. However, two factors that influence the observed relaxation rate constants have so far been neglected, namely (i) the role of CSA/dipolar cross-correlated relaxation (CCR), and (ii) the impact of fast proton spin flips (i.e. proton spin diffusion and relaxation). We show that CSA/D CCR in R1ρ experiments is measurable, and that this cross-correlated relaxation rate constant depends on ns-ms motions, and can thus itself provide insight into dynamics. We find that proton spin-diffusion attenuates this cross-correlated relaxation, due to its decoupling effect on the doublet components. For measurements of dynamics, the use of R1ρ rate constants has practical advantages over the use of CCR rates, and the present manuscript reveals factors that have so far been disregarded and which are important for accurate measurements and interpretation. PMID:27500976

  14. Quantum Measurements using Diamond Spins : From Fundamental Tests to Long-Distance Teleportation

    NARCIS (Netherlands)

    Hanson, R.

    2014-01-01

    Spin qubits in diamond provide an excellent platform both for fundamental tests and for realizing extended quantum networks . Here we present our latest results, including the deterministic teleportation over three meters.

  15. Rotational spectroscopy and three-wave mixing of 4-carvomenthenol: A technical guide to measuring chirality in the microwave regime

    International Nuclear Information System (INIS)

    Shubert, V. Alvin; Schmitz, David; Medcraft, Chris; Krin, Anna; Patterson, David; Doyle, John M.; Schnell, Melanie

    2015-01-01

    We apply chirality sensitive microwave three-wave mixing to 4-carvomenthenol, a molecule previously uncharacterized with rotational spectroscopy. We measure its rotational spectrum in the 2-8.5 GHz range and observe three molecular conformers. We describe our method in detail, from the initial step of spectral acquisition and assignment to the final step of determining absolute configuration and enantiomeric excess. Combining fitted rotational constants with dipole moment components derived from quantum chemical calculations, we identify candidate three-wave mixing cycles which were further tested using a double resonance method. Initial optimization of the three-wave mixing signal is done by varying the duration of the second excitation pulse. With known transition dipole matrix elements, absolute configuration can be directly determined from a single measurement

  16. Faraday rotation measurements on JET, and the change in the safety factor profile during a sawtooth collapse

    International Nuclear Information System (INIS)

    O'Rourke, J.; Lazzaro, E.

    1990-01-01

    Abel-inversion of Faraday rotation measurements on JET has shown that in the current flat-top of sawtoothing discharges the axial safety factor, q o , remains significantly below unity (0.75±0.15) throughout the sawtooth period. In this paper we address two limitations of the Abel-inversion technique, namely the dependence of the results on the assumed flux surface geometry (especially the elongation of the flux surfaces near the magnetic axis, κ o ) and their lack of sensitivity to small changes in the poloidal magnetic field. Assumptions about the flux surface geometry have been verified by comparing Faraday rotation measurements along nearly orthogonal chords, and by a self-consistent identification of the plasma equilibirum. The sensitivity to small changes in the poloidal field, such as those which occur during sawtooth instabilities, has been increased by Abel-inverting the changes in the Faraday rotation signals rather than the signals themselves. (author) 2 refs., 3 figs

  17. Electronic phase diagrams and competing ground states of complex iron pnictides and chalcogenides. A Moessbauer spectroscopy and muon spin rotation/relaxation study

    Energy Technology Data Exchange (ETDEWEB)

    Kamusella, Sirko

    2017-03-01

    In this thesis the superconducting and magnetic phases of LiOH(Fe,Co)(Se,S), CuFeAs/CuFeSb, and LaFeP{sub 1-x}As{sub x}O - belonging to the 11, 111 and 1111 structural classes of iron-based arsenides and chalcogenides - are investigated by means of {sup 57}Fe Moessbauer spectroscopy and muon spin rotation/relaxation (μSR). Of major importance in this study is the application of high magnetic fields in Moessbauer spectroscopy to distinguish and characterize ferro- (FM) and antiferromagnetic (AFM) order. A user-friendly Moessbauer data analysis program was developed to provide suitable model functions not only for high field spectra, but relaxation spectra or parameter distributions in general. In LaFeP{sub 1-x}As{sub x}O the reconstruction of the Fermi surface is described by the vanishing of the Γ hole pocket with decreasing x. The continuous change of the orbital character and the covalency of the d-electrons is shown by Moessbauer spectroscopy. A novel antiferromagnetic phase with small magnetic moments of ∼ 0.1 μ{sub B} state is characterized. The superconducting order parameter is proven to continuously change from a nodal to a fully gapped s-wave like Fermi surface in the superconducting regime as a function of x, partially investigated on (O,F) substituted samples. LiOHFeSe is one of the novel intercalated FeSe compounds, showing strongly increased T{sub C} = 43 K mainly due to increased interlayer spacing and resulting two-dimensionality of the Fermi surface. The primary interest of the samples of this thesis is the simultaneously observed ferromagnetism and superconductivity. The local probe techniques prove that superconducting sample volume gets replaced by ferromagnetic volume. Ferromagnetism arises from magnetic order with T{sub C} = 10 K of secondary iron in the interlayer. The tendency of this system to show (Li,Fe) disorder is preserved upon (Se,S) substitution. However, superconductivity gets suppressed. The results of Moessbauer spectroscopy

  18. Measuring the spin polarization of alkali-metal atoms using nuclear magnetic resonance frequency shifts of noble gases

    Directory of Open Access Journals (Sweden)

    X. H. Liu

    2015-10-01

    Full Text Available We report a novel method of measuring the spin polarization of alkali-metal atoms by detecting the NMR frequency shifts of noble gases. We calculated the profile of 87Rb D1 line absorption cross sections. We then measured the absorption profile of the sample cell, from which we calculated the 87Rb number densities at different temperatures. Then we measured the frequency shifts resulted from the spin polarization of the 87Rb atoms and calculated its polarization degrees at different temperatures. The behavior of frequency shifts versus temperature in experiment was consistent with theoretical calculation, which may be used as compensative signal for the NMRG closed-loop control system.

  19. The impact of rotator cuff tendinopathy on proprioception, measuring force sensation.

    Science.gov (United States)

    Maenhout, Annelies G; Palmans, Tanneke; De Muynck, Martine; De Wilde, Lieven F; Cools, Ann M

    2012-08-01

    The impact of rotator cuff tendinopathy and related impingement on proprioception is not well understood. Numerous quantitative and qualitative changes in shoulder muscles have been shown in patients with rotator cuff tendinopathy. These findings suggest that control of force might be affected. This investigation wants to evaluate force sensation, a submodality of proprioception, in patients with rotator cuff tendinopathy. Thirty-six patients with rotator cuff tendinopathy and 30 matched healthy subjects performed force reproduction tests to isometric external and internal rotation to investigate how accurately they could reproduce a fixed target (50% MVC). Relative error, constant error, and force steadiness were calculated to evaluate respectively magnitude of error made during the test, direction of this error (overshoot or undershoot), and fluctuations of produced forces. Patients significantly overshoot the target (mean, 6.04% of target) while healthy subjects underestimate the target (mean, -5.76% of target). Relative error and force steadiness are similar in patients with rotator cuff tendinopathy and healthy subjects. Force reproduction tests, as executed in this study, were found to be highly reliable (ICC 0.849 and 0.909). Errors were significantly larger during external rotation tests, compared to internal rotation. Patients overestimate the target during force reproduction tests. This should be taken into account in the rehabilitation of patients with rotator cuff tendinopathy; however, precision of force sensation and steadiness of force exertion remains unaltered. This might indicate that control of muscle force is preserved. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  20. Magnetostrictive patch sensor system for battery-less real-time measurement of torsional vibrations of rotating shafts

    Science.gov (United States)

    Lee, Jun Kyu; Seung, Hong Min; Park, Chung Il; Lee, Joo Kyung; Lim, Do Hyeong; Kim, Yoon Young

    2018-02-01

    Real-time uninterrupted measurement for torsional vibrations of rotating shafts is crucial for permanent health monitoring. So far, strain gauge systems with telemetry units have been used for real-time monitoring. However, they have a critical disadvantage in that shaft operations must be stopped intermittently to replace telemetry unit batteries. To find an alternative method to carry out battery-less real-time measurement for torsional vibrations of rotating shafts, a magnetostrictive patch sensor system was proposed in the present study. Since the proposed sensor does not use any powered telemetry system, no battery is needed and thus there is no need to stop rotating shafts for battery replacement. The proposed sensor consists of magnetostrictive patches and small magnets tightly bonded onto a shaft. A solenoid coil is placed around the shaft to convert magnetostrictive patch deformation by shaft torsional vibration into electric voltage output. For sensor design and characterization, investigations were performed in a laboratory on relatively small-sized stationary solid shaft. A magnetostrictive patch sensor system was then designed and installed on a large rotating propulsion shaft of an LPG carrier ship in operation. Vibration signals were measured using the proposed sensor system and compared to those measured with a telemetry unit-equipped strain gauge system.

  1. Adaptation of the S-5-S Pendulím Seismometer for Measurement of Rotational Ground Motion

    Czech Academy of Sciences Publication Activity Database

    Knejzlík, Jaromír; Kaláb, Zdeněk; Rambouský, Zdeněk

    2012-01-01

    Roč. 16, č. 4 (2012), s. 649-656 ISSN 1383-4649 Institutional support: RVO:68145535 Keywords : rotation al ground motion * experimental measurement * mining induced seismicity * S-5-S seismometer Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.388, year: 2012 http://link.springer.com/article/10.1007%2Fs10950-012-9279-6

  2. Analysis of the transient rotating cylinder apparatus for the measurement of liquid-liquid interface shear viscosity

    DEFF Research Database (Denmark)

    Hassager, Ole; Westborg, H

    1987-01-01

    An analysis of the transient rotating cylinder apparatus for the measurement of liquid-liquid interface viscosity is given. An analytical expression that allows the determination of the interfacial viscosity from observations of the interface movement is given. The expression is presented...... in tabular form for selected values of the physical parameters of the two phases, and suggestions for apparatus design are given....

  3. Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

    International Nuclear Information System (INIS)

    Bitter, M.; Wong, K.L.; Scott, S.; Hsuan, H.; Grek, B.; Johnson, D.; Tait, G.

    1990-01-01

    The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments [Phys. Rev. Lett. 55, 2587 (1985)] with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted Ti XXI Kα line radiation. The experiments were conducted for neutral beam powers in the range 2.1--3.8 MW and line-averaged densities in the range 1.8--3.0x10 19 m -2 . The observed rotation velocity increase during compression is consistent with theoretical estimates

  4. Statistical properties of Faraday rotation measure in external galaxies - I: intervening disc galaxies

    Science.gov (United States)

    Basu, Aritra; Mao, S. A.; Fletcher, Andrew; Kanekar, Nissim; Shukurov, Anvar; Schnitzeler, Dominic; Vacca, Valentina; Junklewitz, Henrik

    2018-03-01

    Deriving the Faraday rotation measure (RM) of quasar absorption line systems, which are tracers of high-redshift galaxies intervening background quasars, is a powerful tool for probing magnetic fields in distant galaxies. Statistically comparing the RM distributions of two quasar samples, with and without absorption line systems, allows one to infer magnetic field properties of the intervening galaxy population. Here, we have derived the analytical form of the probability distribution function (PDF) of RM produced by a single galaxy with an axisymmetric large-scale magnetic field. We then further determine the PDF of RM for one random sight line traversing each galaxy in a population with a large-scale magnetic field prescription. We find that the resulting PDF of RM is dominated by a Lorentzian with a width that is directly related to the mean axisymmetric large-scale field strength ⟨B0⟩ of the galaxy population if the dispersion of B0 within the population is smaller than ⟨B0⟩. Provided that RMs produced by the intervening galaxies have been successfully isolated from other RM contributions along the line of sight, our simple model suggests that ⟨B0⟩ in galaxies probed by quasar absorption line systems can be measured within ≈50 per cent accuracy without additional constraints on the magneto-ionic medium properties of the galaxies. Finally, we discuss quasar sample selection criteria that are crucial to reliably interpret observations, and argue that within the limitations of the current database of absorption line systems, high-metallicity damped Lyman-α absorbers are best suited to study galactic dynamo action in distant disc galaxies.

  5. Performance assessment of a new laser system for efficient spin exchange optical pumping in a spin maser measurement of 129Xe EDM

    International Nuclear Information System (INIS)

    Funayama, C.; Furukawa, T.; Sato, T.; Ichikawa, Y.; Ohtomo, Y.; Sakamoto, Y.; Kojima, S.; Suzuki, T.; Hirao, C.; Chikamori, M.; Hikota, E.; Tsuchiya, M.; Yoshimi, A.; Bidinosti, C. P.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

    2015-01-01

    We demonstrate spin-exchange optical pumping of 129 Xe atoms with our newly made laser system. The new laser system was prepared to provide higher laser power required for the stable operation of spin maser oscillations in the 129 Xe EDM experiment. We studied the optimum cell temperature and pumping laser power to improve the degree of 129 Xe spin polarization. The best performance was achieved at the cell temperature of 100 ∘ C with the presently available laser power of 1 W. The results show that a more intense laser is required for further improvement of the spin polarization at higher cell temperatures in our experiment

  6. Impact-Free Measurement of Microtubule Rotations on Kinesin and Cytoplasmic-Dynein Coated Surfaces.

    Directory of Open Access Journals (Sweden)

    Aniruddha Mitra

    Full Text Available Knowledge about the three-dimensional stepping of motor proteins on the surface of microtubules (MTs as well as the torsional components in their power strokes can be inferred from longitudinal MT rotations in gliding motility assays. In previous studies, optical detection of these rotations relied on the tracking of rather large optical probes present on the outer MT surface. However, these probes may act as obstacles for motor stepping and may prevent the unhindered rotation of the gliding MTs. To overcome these limitations, we devised a novel, impact-free method to detect MT rotations based on fluorescent speckles within the MT structure in combination with fluorescence-interference contrast microscopy. We (i confirmed the rotational pitches of MTs gliding on surfaces coated by kinesin-1 and kinesin-8 motors, (ii demonstrated the superiority of our method over previous approaches on kinesin-8 coated surfaces at low ATP concentration, and (iii identified MT rotations driven by mammalian cytoplasmic dynein, indicating that during collective motion cytoplasmic dynein side-steps with a bias in one direction. Our novel method is easy to implement on any state-of-the-art fluorescence microscope and allows for high-throughput experiments.

  7. Spin- (1)/(2) Heisenberg ladder: Variation of entanglement and fidelity measures close to quantum critical points

    Science.gov (United States)

    Tribedi, Amit; Bose, Indrani

    2009-01-01

    We consider a two-chain, spin- (1)/(2) antiferromagnetic Heisenberg spin ladder in an external magnetic field H . The spin ladder is known to undergo second-order quantum phase transitions (QPTs) at two critical values Hc1 and Hc2 of the magnetic field. There are now known examples of strongly coupled (where the rung exchange interaction is much stronger than the nearest-neighbor intrachain exchange interaction) organic ladder compounds in which QPTs have been experimentally observed. In this paper, we investigate whether well-known bipartite entanglement meaures such as one-site von Neumann entropy, two-site von Neumann entropy, and concurrence develop special features close to the quantum critical points. As suggested by an earlier theorem, the first derivatives of the measures with respect to magnetic field are expected to diverge as H→Hc1 and H→Hc2 . Based on numerical diagonalization data and a mapping of the strongly coupled ladder Hamiltonian onto the XXZ chain Hamiltonian, for which several analytical results are known, we find that the derivatives of the entanglement measures diverge as H→Hc2 but remain finite as H→Hc1 . The reason for this discrepancy is analyzed. We further calculate two recently proposed quantum information theoretic measures, the reduced fidelity and reduced fidelity susceptibility, and show that these measures provide appropriate signatures of the QPTs occuring at the critical points H=Hc1 and H=Hc2 .

  8. The g$p\\atop{2}$ Experiment: A Measurement of the Proton's Spin Structure Functions

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, Ryan B. [Univ. of New Hampshire, Durham, NH (United States)

    2017-09-01

    The E08-027 (g$p\\atop{2}$) experiment measured the spin structure functions of the proton at Jefferson Laboratory in Newport News, Va. Longitudinally polarized electrons were scattered from a transversely and longitudinally polarized solid ammonia target in Hall A, with the polarized NH$_3$ acting as an effective proton target. Focusing on small scattering angle events at the electron energies available at Jefferson Lab, the experiment covered a kinematic phase space of 0.02 GeV$^2$ $< Q^2 <$ 0.20 GeV$^2$ in the proton's resonance region. The spin structure functions, $g_{1}^p(x,Q^2)$ and $g_{2}^p(x,Q^2)$ , are extracted from an inclusive polarized cross section measurement of the electron-proton interaction. Integrated moments of $g_1(x,Q^2)$ are calculated and compared to theoretical predictions made by Chiral Perturbation Theory. The $g_1(x,Q^2)$ results are in agreement with previous measurements, but include a significant increase in statistical precision. The spin structure function contributions to the hyperfine energy levels in the hydrogen atom are also investigated. The $g_2(x,Q^2)$ measured contribution to the hyperfine splitting is the first ever experimental determination of this quantity. The results of this thesis suggest a disagreement of over 100% with previously published model results.

  9. All-optical evaluation of spin-orbit interaction based on diffusive spin motion in a two-dimensional electron gas

    Energy Technology Data Exchange (ETDEWEB)

    Kohda, M. [IBM Research–Zürich, Säumerstrasse 4, CH-8803 Rüschlikon (Switzerland); Department of Materials Science, Tohoku University, 980-8579 Sendai (Japan); Altmann, P.; Salis, G. [IBM Research–Zürich, Säumerstrasse 4, CH-8803 Rüschlikon (Switzerland); Schuh, D.; Ganichev, S. D. [Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg (Germany); Wegscheider, W. [Solid State Physics Laboratory, ETH Zürich, CH-8093 Zürich (Switzerland)

    2015-10-26

    A method is presented that enables the measurement of spin-orbit coefficients in a diffusive two-dimensional electron gas without the need for processing the sample structure, applying electrical currents or resolving the spatial pattern of the spin mode. It is based on the dependence of the average electron velocity on the spatial distance between local excitation and detection of spin polarization, resulting in a variation of spin precession frequency that in an external magnetic field is linear in the spatial separation. By scanning the relative positions of the exciting and probing spots in a time-resolved Kerr rotation microscope, frequency gradients along the [100] and [010] crystal axes of GaAs/AlGaAs QWs are measured to obtain the Rashba and Dresselhaus spin-orbit coefficients, α and β. This simple method can be applied in a variety of materials with electron diffusion for evaluating spin-orbit coefficients.

  10. Single and double spin asymmetries for deeply virtual Compton scattering measured with CLAS and a longitudinally polarized proton target

    Energy Technology Data Exchange (ETDEWEB)

    Pisano, S.; Biselli, A.; Niccolai, S.; Seder, E.; Guidal, M.; Mirazita, M.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bosted, P.; Briscoe, B.; Brock, J.; Brooks, W. K.; Burkert, V. D.; Carlin, C.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crabb, D. G.; Crede, V.; D' Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garcon, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, X.; Jo, H. S.; Joo, K.; Joosten, S.; Keith, C. D.; Keller, D.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacCormick, M.; MacGregor, Ian J. D.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Meyer, C. A.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Munoz Camacho, C.; Nadel-Turonski, P.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Phelps, W.; Phillips, J. J.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatie, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Skorodumina, I.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Turisini, M.; Ungaro, M.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-03-19

    Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'γ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.

  11. A technique for measurement of vector and tensor polarization in solid spin one polarized targets

    Energy Technology Data Exchange (ETDEWEB)

    Kielhorn, W.F.

    1991-06-01

    Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs.

  12. A technique for measurement of vector and tensor polarization in solid spin one polarized targets

    International Nuclear Information System (INIS)

    Kielhorn, W.F.

    1991-06-01

    Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs

  13. Measurements Of Spin Observables In Pseudoscalar-Meson Photo-Production Using Polarized Neutrons In Solid HD

    Energy Technology Data Exchange (ETDEWEB)

    Kageya, Tsuneo

    2014-01-01

    Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an efficient neutron target. Preliminary E asymmetries for the exclusive reaction, gamma + n(p)--> pi- + p(p), selecting quasi free neutron kinematics are discussed.

  14. A novel vibration-based fault diagnostic algorithm for gearboxes under speed fluctuations without rotational speed measurement

    Science.gov (United States)

    Hong, Liu; Qu, Yongzhi; Dhupia, Jaspreet Singh; Sheng, Shuangwen; Tan, Yuegang; Zhou, Zude

    2017-09-01

    The localized failures of gears introduce cyclic-transient impulses in the measured gearbox vibration signals. These impulses are usually identified from the sidebands around gear-mesh harmonics through the spectral analysis of cyclo-stationary signals. However, in practice, several high-powered applications of gearboxes like wind turbines are intrinsically characterized by nonstationary processes that blur the measured vibration spectra of a gearbox and deteriorate the efficacy of spectral diagnostic methods. Although order-tracking techniques have been proposed to improve the performance of spectral diagnosis for nonstationary signals measured in such applications, the required hardware for the measurement of rotational speed of these machines is often unavailable in industrial settings. Moreover, existing tacho-less order-tracking approaches are usually limited by the high time-frequency resolution requirement, which is a prerequisite for the precise estimation of the instantaneous frequency. To address such issues, a novel fault-signature enhancement algorithm is proposed that can alleviate the spectral smearing without the need of rotational speed measurement. This proposed tacho-less diagnostic technique resamples the measured acceleration signal of the gearbox based on the optimal warping path evaluated from the fast dynamic time-warping algorithm, which aligns a filtered shaft rotational harmonic signal with respect to a reference signal assuming a constant shaft rotational speed estimated from the approximation of operational speed. The effectiveness of this method is validated using both simulated signals from a fixed-axis gear pair under nonstationary conditions and experimental measurements from a 750-kW planetary wind turbine gearbox on a dynamometer test rig. The results demonstrate that the proposed algorithm can identify fault information from typical gearbox vibration measurements carried out in a resource-constrained industrial environment.

  15. Non-adiabatic Landau-Zener transitions in low-spin molecular magnet V sub 1 sub 5

    CERN Document Server

    Chiorescu, I; Müller, A; Bögge, H; Barbara, B

    2000-01-01

    The V sub 1 sub 5 polyoxovanadate molecule is made of 15 spins ((1)/(2)) with antiferromagnetic couplings. It belongs to the class of molecules with very large Hilbert space dimension (2 sup 1 sup 5 in V sub 1 sub 5 , 10 sup 8 in Mn sub 1 sub 2 -AC). It is a low spin/large molecule with spin S=((1)/(2)). Contrary to large spins/large molecules of the Mn sub 1 sub 2 -AC type, V sub 1 sub 5 has no energy barrier against spin rotation. Magnetization measurements have been performed and despite the absence of a barrier, magnetic hysteresis is observed over a timescale of several seconds. This new phenomenon characterized by a 'butterfly' hysteresis loop is due to the effect of the environment on the quantum rotation of the entangled 15 spins of the molecule, in which the phonon density of states is not at its equilibrium (phonon bottleneck).

  16. Measuring the contribution of low Bjorken-x gluons to the proton spin with polarized proton-proton collisions

    Science.gov (United States)

    Wolin, Scott Justin

    The PHENIX experiment is one of two detectors located at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, NY. Understanding the spin structure of the proton is a central goal at RHIC, the only polarized proton-on-proton collider in existence. The PHENIX spin program has two primary objectives. The first is to improve the constraints on the polarized parton distributions of the anti-u and anti-d quarks within the proton. The second objective is to improve the constraint on the gluon spin contribution to the proton spin, DeltaG. The focus of this thesis is the second objective. PHENIX experiment has been successful at providing the first meaningful constraints on DeltaG, along with STAR, the other detector located at RHIC. These constraints have, in fact, eliminated the extreme scenarios for gluon polarization through measurements of the double spin asymmetry, ALL, between the cross section of like and unlike sign helicity pp interactions. ALL measurements can be performed with a variety of final states at PHENIX. Until 2009, these final states were only measured for pseudo-rapidities of |eta| car crashing into a slow moving car and the debris ending up mostly along the line of motion of the fast moving car, the debris of a high-x quark interacting with a low-x gluon will result in debris at forward rapidity at small angles to the initial quark momentum. The Muon Piston Calorimeter (MPC) was installed in 2006 and 2007 at forward rapidity, 3.1 Following this, an electronics upgrade to the MPC will be described which enables the selection of events with two hadrons detected in the MPC. This requirement favors gluons at even lower x than the single hadron event selection. The di-hadron measurement that this upgrade makes possible will allow PHENIX to produce an ALL measurement that constrains Deltag(x) in the range of 5 x 10-4 < x < 0.01. Finally, we discuss the most important systematic uncertainty common to all ALL measurements

  17. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Balewski, J; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-15

    We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  18. Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at RHIC

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at √s =510 GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  19. Measurement and Finite Element Model Validation of Immature Porcine Brain-Skull Displacement during Rapid Sagittal Head Rotations.

    Science.gov (United States)

    Pasquesi, Stephanie A; Margulies, Susan S

    2018-01-01

    Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain-skull displacement in the neonatal piglet head ( n  = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain-skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain-skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain-skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain-skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.

  20. Measurement and Finite Element Model Validation of Immature Porcine Brain–Skull Displacement during Rapid Sagittal Head Rotations

    Directory of Open Access Journals (Sweden)

    Stephanie A. Pasquesi

    2018-02-01

    Full Text Available Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain–skull displacement in the neonatal piglet head (n = 3 at the sagittal midline during six rapid non-impact rotations (two rotations per specimen with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain–skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain–skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain–skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain–skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.