WorldWideScience

Sample records for linearly polarised photon

  1. Linearly polarised photons at the BGO-OD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Andreas [Physikalisches Institut, Universitaet Bonn (Germany); Collaboration: BGO-OD-Collaboration

    2015-07-01

    The BGO-OD experiment, located at the ELSA accelerator of the University of Bonn, aims at the study of photoproduction reactions off the nucleon. A real, energy-tagged photon beam is produced via bremsstrahlung by irradiating a thin radiator with the electron beam provided by ELSA. Linear polarisation is obtained by coherent bremsstrahlung. This requires a crystal radiator; in our case a 570 μm thick diamond is used. The production mechanism of a linearly polarised photon beam via coherent bremsstrahlung, the determination of the degree of polarisation and first results obtained with a linearly polarised photon beam are shown in this talk.

  2. Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons

    CERN Document Server

    Apyan, A; Badelek, B; Ballestrero, S; Biino, C; Birol, I; Cenci, P; Connell, S H; Eichblatt, S; Fonseca, T; Freund, A; Gorini, B; Groess, R; Ispirian, K; Ketel, T; Kononets, Yu V; López, A; Mangiarotti, A; Sellschop, J P Friedel; Shieh, M; Sona, P; Strakhovenko, V M; Uggerhøj, Erik; Uggerhøj, U; Van Rens, B; Velasco, M; Vilakazi, Z Z; Wessely, O; Ünel, G; Kononets, Yu.V.

    2003-01-01

    We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linearly polarised photon beam. The linearly polarised photon beam is produced from coherent bremsstrahlung radiation by 178 GeV unpolarised electrons incident on an aligned Si crystal, acting as a radiator. The linear polarisation of the photon beam is characterised by measuring the asymmetry in electron-positron pair production in a Ge crystal, for different crystal orientations. The Ge crystal therefore acts as an analyser. The birefringence phenomenon, which converts the linear polarisation to circular polarisation, is observed by letting the linearly polarised photons beam pass through a thick Si quarter wave plate crystal, and then measuring the asymmetry in electron-positron pair production again for a selection of relative angles between the crystallographic planes of the radiator, analyser and quarter wave plate. The systematics...

  3. Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton

    CERN Document Server

    Elsner, D; Bartholomy, O; Bayadilov, D E; Beck, R; Beloglasov, Yu A; Castelijns, R; Credé, V; Ehmanns, A; Essig, K; Ewald, R; Fabry, I; Fornet-Ponse, K; Fuchs, M; Funke, C; Gridnev, A B; Gutz, E; Hoeffgen, S; Hoffmeister, P; Horn, I; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Friedrich; Klempt, E; Konrad, M; Kotulla, M; Krusche, B; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Mertens, T; Messchendorp, J G; Metag, V; Morales, C; Nanova, M; Novinski, D V; Novotny, R; Ostrick, M; Pant, L M; Van Pee, H; Pfeiffer, M; Sarantsev, A V; Schmidt, C; Schmieden, H; Schoch, B; Shende, S; Suele, A; Sumachev, V V; Szczepanek, T; Thoma, U; Trnka, D; Walther, D; Weinheimer, C; Wendel, C

    2008-01-01

    At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement between experiment and expectations on basis of the experimental conditions is obtained. Polarisation degrees of P = 40% are typically achieved at half of the primary electron energy. The determination of P is confirmed by measuring the beam asymmetry, \\Sigma, in pi^0 photoproduction and a comparison of the results to independent measurements using laser backscattering.

  4. Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in π0_{} photoproduction off the proton

    Science.gov (United States)

    Elsner, D.; Bantes, B.; Bartholomy, O.; Bayadilov, D. E.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Crede, V.; Ehmanns, A.; Essig, K.; Ewald, R.; Fabry, I.; Frommberger, F.; Fornet-Ponse, K.; Fuchs, M.; Funke, C.; Gridnev, A. B.; Gutz, E.; Hillert, W.; Höffgen, S.; Hoffmeister, P.; Horn, I.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Klein, Frank; Klein, Friedrich; Klempt, E.; Konrad, M.; Kotulla, M.; Krusche, B.; Löhner, H.; Lopatin, I. V.; Lotz, J.; Lugert, S.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Morales, C.; Nanova, M.; Novinski, D. V.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Sarantsev, A. V.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Süle, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Walther, D.; Weinheimer, C.; Wendel, C.

    2009-03-01

    At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement between experiment and expectations on the basis of the experimental conditions is obtained. Polarisation degrees of ensuremath P_{γ}=40 % are typically achieved at half of the primary electron energy. The determination of ensuremath P_{γ} is confirmed by measuring the beam asymmetry, Σ , in π0_{} photoproduction and by a comparison of the results to independent measurements using laser backscattering.

  5. Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in {pi}{sup 0} photoproduction off the proton

    Energy Technology Data Exchange (ETDEWEB)

    Elsner, D.; Bantes, B.; Ewald, R.; Frommberger, F.; Fornet-Ponse, K.; Hillert, W.; Hoeffgen, S.; Klein, Frank; Klein, Friedrich; Konrad, M.; Menze, D.; Morales, C.; Ostrick, M.; Schmieden, H.; Schoch, B.; Suele, A.; Walther, D. [Physikalisches Institut der Universitaet Bonn, Bonn (Germany); Bartholomy, O.; Beck, R.; Ehmanns, A.; Essig, K.; Fabry, I.; Fuchs, M.; Funke, C.; Gutz, E.; Hoffmeister, P.; Horn, I.; Junkersfeld, J.; Kalinowsky, H.; Klempt, E.; Lotz, J.; van Pee, H.; Schmidt, C.; Szczepanek, T.; Thoma, U.; Weinheimer, C.; Wendel, C. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Bayadilov, D.E.; Novinski, D.V.; Sarantsev, A.V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Beloglazov, Y.A.; Gridnev, A.B.; Lopatin, I.V.; Sumachev, V.V. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Castelijns, R.; Loehner, H.; Messchendorp, J.G.; Shende, S. [University of Groningen, KVI, Groningen (Netherlands); Crede, V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn, Bonn (Germany); Florida State University, Department of Physics, Tallahassee (United States); Jaegle, I.; Krusche, B.; Mertens, T. [Universitaet Basel, Physikalisches Institut, Basel (Switzerland); Kotulla, M. [Universitaet Basel, Physikalisches Institut, Basel (Switzerland); Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Lugert, S.; Metag, V.; Nanova, M.; Novotny, R.; Pant, L.M.; Pfeiffer, M.; Trnka, D. [Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany)

    2009-03-15

    At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement between experiment and expectations on the basis of the experimental conditions is obtained. Polarisation degrees of P{sub {gamma}}=40 % are typically achieved at half of the primary electron energy. The determination of P{sub {gamma}} is confirmed by measuring the beam asymmetry, {sigma}, in {pi}{sup 0} photoproduction and by a comparison of the results to independent measurements using laser backscattering. (orig.)

  6. The stability of polarisation singularities in disordered photonic crystal waveguides

    CERN Document Server

    Lang, Ben; Young, Andrew B; Rarity, John G; Oulton, Ruth

    2015-01-01

    The effects of short range disorder on the polarisation characteristics of light in photonic crystal waveguides were investigated using finite difference time domain simulations with a view to investigating the stability of polarisation singularities. It was found that points of local circular polarisation (C-points) and contours of linear polarisation (L-lines) continued to appear even in the presence of high levels of disorder, and that they remained close to their positions in the ordered crystal. These results are a promising indication that devices exploiting polarisation in these structures are viable given current fabrication standards.

  7. The Polarised Photon $g_1^\\gamma$ Sum Rule at the Linear Collider and High Luminosity B Factories

    CERN Document Server

    Shore, G M

    2004-01-01

    The sum rule for the first moment of the polarised (virtual) photon structure function $g_1^\\gamma(x,Q^2;K^2)$ is revisited in the light of proposals for future $e^+ e^-$ colliders. The sum rule exhibits an array of phenomena characteristic of QCD: for real photons ($K^2=0$) electromagnetic gauge invariance constrains the first moment to vanish; the limit for asymptotic photon virtuality ($m_\\rho^2 \\ll K^2 \\ll Q^2$) is governed by the electromagnetic $U_A(1)$ axial anomaly and the approach to asymptopia by the gluonic anomaly; for intermediate values of $K^2$, it reflects the realisation of chiral symmetry and is determined by the off-shell radiative couplings of the pseudoscalar mesons; finally, like many polarisation phenomena in QCD, the first moment of $g_1^\\gamma$ involves the gluon topological susceptibility. In this paper, we review the original sum rule proposed by Narison, Shore and Veneziano and extend the relation with pseudoscalar mesons. The possibility of measuring the sum rule in future polaris...

  8. Constraining ALPs with linear and circular polarisation measurements of quasar light

    Energy Technology Data Exchange (ETDEWEB)

    Payez, Alexandre [Liege Univ. (Belgium). IFPA Group; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-09-15

    We discuss the constraints derived on the mixing of photons with light pseudoscalars using the distributions of good-quality linear and circular polarisation measurements of light from the least polarised classes of quasars. We also provide the dependence of our limit on the average electron density in the local supercluster for nearly massless particles.

  9. Broadband microwave photonic phase shifter based on polarisation rotation

    DEFF Research Database (Denmark)

    Xue, Weiqi; Öhman, Filip; Blaaberg, Søren;

    2008-01-01

    A broadband microwave photonic phase shifter is presented based on the polarisation properties of a Mach-Zehnder intensity modulator and nonlinear polarisation rotation in a semiconductor optical amplifier. The system can realise about 150deg phase shift in the frequency range from 50 MHz to 19 GHz....

  10. Polarised two-photon excitation of quantum well excitons for manipulation of optically pumped terahertz lasers

    Energy Technology Data Exchange (ETDEWEB)

    Slavcheva, G., E-mail: gsk23@bath.ac.uk [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Kavokin, A.V., E-mail: A.Kavokin@soton.ac.uk [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Spin Optics Laboratory, St. Petersburg State University, 1, Ulyanovskaya 198504 (Russian Federation)

    2014-11-15

    Optical pumping of excited exciton states in a semiconductor quantum well embedded in a microcavity is a tool for realisation of ultra-compact terahertz (THz) lasers based on stimulated optical transition between excited (2p) and ground (1s) exciton state. We show that the probability of two-photon absorption by a 2p-exciton is strongly dependent on the polarisation of both pumping photons. Five-fold variation of the threshold power for terahertz lasing by switching from circular to co-linear pumping is predicted. We identify photon polarisation configurations for achieving maximum THz photon generation quantum efficiency.

  11. Maintaining photonic quantum polarisation entanglement in nanoscale waveguides

    CERN Document Server

    Li, Ming; Ren, Xi-Feng; Xiong, Xiao; Cai, Yong-Jing; Guo, Guo-Ping; Tong, Li-Min; Guo, Guang-Can

    2014-01-01

    In this work, we demonstrate for the first time the maintaining of quantum polarisation entanglement in both a nanoscale dielectric tapered fibre and a plasmonic waveguide. Entangled photons are coupled into these waveguides, and quantum state tomography is used to verify that the transmitted states have fidelities of 0.958 and 0.932 with the maximally polarisation entangled state Phi^{+}, respectively. Furthermore, the Clauser, Horne, Shimony, and Holt (CHSH) inequality tests performed, resulting in values of$2.588\\pm0.141>2 and 2.495\\pm0.147>2, respectively, demonstrate the violation of the hidden variable model. Our investigations pave the way toward a quantum near-field micro/nano-scope, which can realize high spatial resolution, ultra-sensitive, fibre-integrated, and plasmon-enhanced detection, as well as bridge nanophotonics and quantum metrology.

  12. Tunable polarisation-maintaining filter based on liquid crystal photonic bandgap fibre

    DEFF Research Database (Denmark)

    Scolari, Lara; Olausson, Christina Bjarnal Thulin; Weirich, Johannes

    2008-01-01

    A tunable and polarisation-maintaining all-in-fibre filter based on a liquid crystal photonic bandgap fibre is demonstrated. Its polarisation extinction ratio reaches 14 dB at 1550 nm wavelength. Its spectral tunability range spans over 250 nm in the temperature range 30–70°C. The measured...

  13. Polarisation Sensitive Single Molecule Fluorescence Detection with Linear Polarised Excitation Light and Modulated Polarisation Direction Applied to Multichromophoric Entities

    NARCIS (Netherlands)

    Gensch, T.; Hofkens, J.; Köhn, F.; Vosch, T.; Herrmann, A.; Müllen, K.; Schryver, F.C. De

    2001-01-01

    Recently, investigations of the fluorescence properties of a multichromophoric dendritic entity at the single molecule level have revealed multiple fluorescence levels, collective off-states, variations of the polarisation, large shifts in the spectral position and changes in the fluorescence decay

  14. Exclusive Leptoproduction of Real Photons on a Longitudinally Polarised Hydrogen Target

    CERN Document Server

    Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetissian, A; Avetisyan, E; Ball, B; Belostotski, S; Bianchi, N; Blok, H P; Boettcher, H; Borissov, A; Bowles, J; Brodski, I; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Nardo, L; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Dueren, M; Ehrenfried, M; Elbakian, G; Ellinghaus, F; Fabbri, R; Fantoni, A; Felawka, L; Frullani, S; Gabbert, D; Gapienko, G; Gapienko, V; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Golembiovskaya, M; Hadjidakis, C; Hartig, M; Hasch, D; Hill, G; Hillenbrand, A; Hoek, M; Holler, Y; Hristova, I; Imazu, Y; Ivanilov, A; Izotov, A; Jackson, H E; Jo, H S; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Kobayashi, N; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhijne, V G; Lagamba, L; Lamb, R; Lapikas, L; Lehmann, I; Lenisa, P; Linden-Levy, L A; Lopez~Ruiz, A; Lorenzon, W; Lu, X -G; Lu, X -R; Ma, B -Q; Mahon, D; Makins, N C R; Manaenkov, S I; Manfre, L; Mao, Y; Marianski, B; de la Ossa, A Martinez; Marukyan, H; Miller, C A; Miyachi, Y; Movsisyan, A; Muccifora, V; Murray, M; Mussgiller, A; Nappi, E; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Pickert, N; Raithel, M; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanftl, F; Schaefer, A; Schnell, G; Schueler, K P; Seitz, B; Shibata, T -A; Shutov, V; Stancari, M; Statera, M; Steffens, E; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Taroian, S; Terkulov, A; Trzcinski, A; Tytgat, M; Vandenbroucke, A; van der Nat, P B; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Vogel, C; Wang, S; Yaschenko, S; Ye, H; Ye, Z; Yen, S; Yu, W; Zeiler, D; Zihlmann, B; Zupranski, P

    2010-01-01

    Polarisation asymmetries are measured for the hard exclusive leptoproduction of real photons from a longitudinally polarised hydrogen target. These asymmetries arise from the deeply virtual Compton scattering and Bethe-Heitler processes. From the data are extracted two asymmetries in the azimuthal distribution of produced real photons about the direction of the exchanged virtual photon: A_UL with respect to the target polarisation and A_LL with respect to the product of the beam and target polarisations. Results for both asymmetries are compared to the predictions from a generalised parton distribution model. The sin(phi) and cos(0*phi) amplitudes observed respectively for the A_UL and A_LL asymmetries are compatible with the sizeable predictions from the model. Unexpectedly, a sin(2*phi) modulation in the A_UL asymmetry with a magnitude similar to that of the sin(phi) modulation is observed.

  15. Synthetic line and continuum linear-polarisation signatures of axisymmetric type II supernova ejecta

    CERN Document Server

    Dessart, Luc

    2011-01-01

    We present synthetic single-line and continuum linear-polarisation signatures due to electron scattering in axially-symmetric Type II supernovae (SNe) which we calculate using a Monte Carlo and a long-characteristic radiative-transfer code. Aspherical ejecta are produced by prescribing a latitudinal scaling or stretching of SN ejecta inputs obtained from 1-D non-LTE time-dependent calculations. We study polarisation signatures as a function of inclination, shape factor, wavelength, line identity, post-explosion time. At early times, cancellation and optical-depth effects make the polarisation intrinsically low, causing complicated sign reversals with inclination or continuum wavelength, and across line profiles. While the line polarisation is positive (negative) for an oblate (prolate) morphology at the peak and in the red wing, the continuum polarisation may be of any sign. These complex polarisation variations are produced not just by the asymmetric distribution of scatterers but also of the flux. Our early...

  16. Very high coupling of TM polarised light in photonic crystal directional couplers

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Thorhauge, Morten; Frandsen, Lars Hagedorn;

    2003-01-01

    noteworthy is the transmission level, experimentally found to be above -3 dB in the wavelength range 1520-1690 nm, for TM polarised light in the coupled channel. It is noted that even though band calculations show that the propagation of the TM polarisation takes place below the TM valence band, very high......The experimental and simulated spectra for TE and TM polarised light for the transmission through photonic crystal directional couplers are presented. The 3D FDTD simulations successfully explain all the major features of the experimental spectra as well as the actual transmission level. Especially...

  17. The linear polarisation of southern bright stars measured at the parts-per-million level

    CERN Document Server

    Cotton, Daniel V; Kedziora-Chudczer, Lucyna; Bott, Kimberly; Lucas, P W; Hough, J H; Marshall, Jonathan P

    2015-01-01

    We report observations of the linear polarisation of a sample of 50 nearby southern bright stars measured to a median sensitivity of $\\sim$4.4 $\\times 10^{-6}$. We find larger polarisations and more highly polarised stars than in the previous PlanetPol survey of northern bright stars. This is attributed to a dustier interstellar medium in the mid-plane of the Galaxy, together with a population containing more B-type stars leading to more intrinsically polarised stars, as well as using a wavelength more sensitive to intrinsic polarisation in late-type giants. Significant polarisation had been identified for only six stars in the survey group previously, whereas we are now able to deduce intrinsic polarigenic mechanisms for more than twenty. The four most highly polarised stars in the sample are the four classical Be stars ($\\alpha$ Eri, $\\alpha$ Col, $\\eta$ Cen and $\\alpha$ Ara). For the three of these objects resolved by interferometry, the position angles are consistent with the orientation of the circumstel...

  18. A spherical grating monochromator and beamline optimised for the provision of polarised synchrotron radiation in the photon energy range 20-200 eV

    Energy Technology Data Exchange (ETDEWEB)

    Finetti, P.; Holland, D.M.P. E-mail: d.m.p.holland@dl.ac.uk; Latimer, C.J.; Binns, C.; Quinn, F.M.; Bowler, M.A.; Grant, A.F.; Mythen, C.S

    2001-12-01

    The design and performance of a spherical grating monochromator and beamline optimised for experiments requiring polarised radiation are described. The beamline is mounted on a bending magnet source at the Synchrotron Radiation Source at Daresbury Laboratory, and the monochromator incorporates three gratings to cover the photon energy range 20-200 eV. The relative first- and higher-order grating efficiencies have been measured by means of photoelectron spectroscopy and have been compared to theoretical predictions. A movable aperture, placed in the optical path between the source and the first mirror, defines the photon emission directions of the beam entering the beamline. The polarisation of the radiation leaving the beamline is determined both by the vertical position of this aperture and by the modifications introduced by the beamline geometry and the optical components. The modification to the polarisation is difficult to calculate analytically, and a satisfactory quantitative assessment can only be accomplished through a combination of reflectivity and ray-tracing analysis. A reflection polarimeter has been used to obtain a full characterisation of the polarisation in the energy range 20-40 eV. These measurements have enabled the Stokes parameters to be deduced. The degree of linear polarisation has also been investigated through angle resolved photoelectron spectroscopy measurements.

  19. Arbitrary photonic wave plate operations on chip: realizing Hadamard, Pauli-X, and rotation gates for polarisation qubits

    National Research Council Canada - National Science Library

    Heilmann, René; Gräfe, Markus; Nolte, Stefan; Szameit, Alexander

    2014-01-01

    .... In our work we close this gap and present Hadamard, Pauli-X, and rotation gates of high fidelity for photonic polarisation qubits on chip by employing a reorientation of the optical axis of birefringent waveguides...

  20. Searches for the Anomalous Photon Polarisation in Radiative B Decays at LHCb

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00455305

    This thesis is exploring the measurements of the photon polarisation in radiative $B$ decays at LHCb, which are mediated through $b\\to s\\gamma$ transitions. To ensure optimal physics performance, procedures to align the LHCb detector and to monitor the alignment quality over time are presented. Using data corresponding to an integrated luminosity of $3~\\text{fb}^{-1}$, collected in the year of 2011 at the centre-of-energy $\\sqrt{s} = 7$~TeV and the year of 2012 at $\\sqrt{s} = 8$~TeV in proton-proton collisions, the photon polarisation parameter $A^\\Delta$, which is related to the ratio of right- over left-handed photon polarisation amplitudes in $b\\to s\\gamma$ transitions, is measured by performing an untagged time-dependent analysis of more than $4000$ $B_s^0\\to \\phi\\gamma$ decays. From an unbinned simultaneous fit to the $B_s^0\\to\\phi\\gamma$ and the control channel $B^0\\to{K^*}^0\\gamma$ data samples, a value of $A^\\Delta = -0.98^{~+0.46}_{~-0.52}\\text{(stat.)}^{~+0.23}_{~-0.20}\\text{(syst.)}$ is measured. T...

  1. First doubly polarised photoproduction on {sup 3}He at the photon beam of MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Aguar Bartolome, Patricia

    2010-11-15

    A first experiment with a polarised {sup 3}He target was carried out in July 2009 at the MAMI accelerator in Mainz in a photon energy range between 200 MeV and 800 MeV. The aim of this measurement was to investigate the Gerasimov-Drell-Hearn sum rule on the neutron. The use of the data obtained with the polarised {sup 3}He target, compared to existing data on the deuteron, gives a complementary and more direct access to the neutron, due to the spin structure of the {sup 3}He. The measurement of the helicity dependence of the inclusive total photoabsorption cross section required a beam of tagged circularly polarised photons incident on the longitudinally polarised {sup 3}He target. The data were taken using the 4{pi} Crystal Ball photon spectrometer in combination with TAPS as a forward wall and complemented by a threshold Cherenkov detector used to on-line suppress the background from electromagnetic events. The development and preparation of the different components of the {sup 3}He experimental setup was an important part of this work and are described in detail in this thesis. The detector system and the analysis method were tested by the measurement of the unpolarised total inclusive photoabsorption cross section on liquid hydrogen. The results obtained are in good agreement with previous published data. Preliminary results of the unpolarised total photoabsorption cross section, as well as the helicity dependent photoabsorption cross section difference on {sup 3}He compared with several theoretical models will also be presented. (orig.)

  2. High-harmonic generation in benzene with linearly- and circularly-polarised laser pulses

    CERN Document Server

    Wardlow, Abigail

    2015-01-01

    High harmonic generation in benzene is studied using a mixed quantum-classical approach in which the electrons are described using time-dependent density functional theory while the ions move classically. The interaction with both circularly- and linearly-polarised infra-red ($\\lambda = 800$ nm) laser pulses of duration 10 cycles (26.7 fs) is considered. The effect of allowing the ions to move is investigated as is the effect of including self-interaction corrections to the exchange-correlation functional. Our results for circularly-polarised pulses are compared with previous calculations in which the ions were kept fixed and self-interaction corrections were not included while our results for linearly-polarised pulses are compared with both previous calculations and experiment. We find that even for the short duration pulses considered here, the ionic motion greatly influences the harmonic spectra. While ionization and ionic displacements are greatest when linearly-polarised pulses are used, the response to ...

  3. 640 Gbit/s time-division add-drop multiplexing using a non-linear polarisation-rotating fibre loop

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Galili, Michael; Grüner-Nielsen, Lars

    2008-01-01

    We report the first demonstration of error-free 640 Gbit/s time-division add-drop multiplexing, performed by non-linear polarisation-rotation using a loop with a polarisation-maintaining HNLF.......We report the first demonstration of error-free 640 Gbit/s time-division add-drop multiplexing, performed by non-linear polarisation-rotation using a loop with a polarisation-maintaining HNLF....

  4. Dust in the diffuse interstellar medium: Extinction, emission, linear and circular polarisation

    CERN Document Server

    Siebenmorgen, R; Bagnulo, S

    2013-01-01

    We present a model for the diffuse interstellar dust that explains the observed wavelength-dependence of extinction, emission, linear and circular polarisation of light. The model is set-up with a small number of parameters. It consists of a mixture of amorphous carbon and silicate grains with sizes from the molecular domain of 0.5 up to about 500nm. Dust grains with radii larger than 6nm are spheroids. Spheroidal dust particles have a factor 1.5 - 3 larger absorption cross section in the far IR than spherical grains of the same volume. Mass estimates derived from submillimeter observations that ignore this effect are overestimated by the same amount. In the presence of a magnetic field, spheroids may be partly aligned and polarise light. We find that polarisation spectra help to determine the upper particle radius of the otherwise rather unconstrained dust size distribution. Stochastically heated small grains of graphite, silicates and polycyclic aromatic hydrocarbons (PAHs) are included. We tabulate paramet...

  5. Nucleon spin-polarisabilities from polarisation observables in low-energy deuteron Compton scattering

    Science.gov (United States)

    Grießhammer, H. W.; Shukla, D.

    2010-11-01

    We investigate the dependence of polarisation observables in elastic deuteron Compton scattering below the pion production threshold on the spin-independent and spin-dependent iso-scalar dipole polarisabilities of the nucleon. The calculation uses Chiral Effective Field Theory ( χ EFT) with dynamical Δ(1232) degrees of freedom in the Small Scale Expansion (SSE) at next-to-leading order. Resummation of the NN intermediate rescattering states and including the Δ induces sizeable effects. The analysis considers cross-sections and the analysing power of linearly polarised photons on an unpolarised target, and cross-section differences and asymmetries of linearly and circularly polarised beams on a vector-polarised deuteron. An intuitive argument helps one to identify kinematics in which one or several polarisabilities do not contribute. Some double-polarised observables are only sensitive to linear combinations of two of the spin-polarisabilities, simplifying a multipole analysis of the data. Spin-polarisabilities can be extracted at photon energies ≳ 100 MeV, after measurements at lower energies of lesssim 70 MeV provide high-accuracy determinations of the spin-independent ones. An interactive Mathematica 7.0 notebook of our findings is available from hgrie@gwu.edu.

  6. Polarisation singularities in photonic crystals for an on-chip spin-photon interface

    Science.gov (United States)

    Beggs, Daryl M.; Young, Andrew B.; Thijssen, Arthur C. T.; Oulton, Ruth

    2015-03-01

    Integrated quantum photonic chips are a leading contender for future quantum technologies, which aim to use the entanglement and superposition properties of quantum physics to speed up the manipulation of data. Quantum information may be stored and transmitted in photons, which make excellent flying qubits. Photons suffer little from decoherence, and single qubit gates performed by changing photon phase, are straightforward. Less straightforward is the ability to create two qubit gates, where one photon is used to switch another's state; inherently difficult due to the extremely small interaction cross-section between photons. The required deterministic two-qubit interactions will likely need a hybrid scheme with the ``flying'' photonic qubit interacting with a ``static'' matter qubit. Here we present the design of a photonic crystal waveguide structure that can couple electron-spin to photon path, thus providing an interface between a static and a flying qubit. We will show that the complex polarization properties inherent in the photonic crystal eigenmodes supports polarization singularities - positions in the electric field vector where one of the parameters describing the local polarization ellipse is singular - and that these singularities are ideal for a range of quantum information applications. In particular, we will show that by placing a quantum dot at one of these singularities, the electron-spin becomes correlated with the photon emission direction, creating an in-plane spin-photon interface that can transfer quantum information from static to flying qubits.

  7. Polarised photon and flavoured lepton quantum Boltzmann equations in the early universe; Polarisierte Photon- und geflavourte Lepton-Quantenboltzmanngleichungen im fruehen Universum

    Energy Technology Data Exchange (ETDEWEB)

    Fidler, Christian

    2011-12-16

    Polarisation and Nongaussianity are expected to play a central role in future studies of the cosmic microwave background radiation. Polarisation can be split into a divergence-like E-mode and a curl-like B-mode, of which the later can only be induced by primordial gravitational waves (tensor fluctuations of the metric) at leading order. Nongaussianity is not generated at first order and is directly proportional to the primordial Nongaussianity of inflation. Thus B-mode polarisation and Nongaussianity constrain inflation models directly. While E-mode polarisation has already been detected and is being observed with increasing precision, B-mode polarisation and Nongaussianity remains elusive. The absence of B-mode polarisation when the primordial fluctuations are purely scalar holds, however, only in linear perturbation theory. B-mode polarisation is also generated from scalar sources in second order, which may constitute an important background to the search for primordial gravitational waves. While such an effect would naturally be expected to be relevant at tensor-to-scalar ratios of order 10{sup -5}, which is the size of perturbations in the microwave background, only a full second order calculation can tell whether there are no enhancements. For Nongaussianity the situation is analogous: At second order intrinsic Nongaussianities are induced to the spectrum, which may be an important background to the primordial Nongaussianity. After the full second-order Boltzmann equations for the cosmological evolution of the polarised radiation distribution have become available, I focused on the novel sources to B-mode polarisation that appear in the second-order collision term, which have not been calculated before. In my PHD thesis I developed a numerical code, which solves the second order Boltzmann hierarchy and calculates the C{sub l}{sup BB}-spectrum.

  8. Towards the measurement of photon polarisation in the decay $B^+ \\to K^+ π^- π^+ \\gamma$

    CERN Document Server

    AUTHOR|(CDS)2083955; Blanc, Frederic

    This thesis presents a study of the flavour-changing neutral-current radiative $B^+ \\rightarrow K^+ \\pi^- \\pi^+ \\gamma$ decay performed using $3\\, \\rm{fb}^{-1}$ of data collected with the LHCb detector in proton-proton collisions at $7$ and $8\\,$TeV centre-of-mass energies. The study of radiative decays with three scalar hadrons in the final state gives access to the polarisation of the photon, one of the very few predictions of the Standard Model of particle physics that has not been precisely tested experimentally and that is sensitive to new physics effects in the $b \\rightarrow s \\gamma$ penguin loop. Nearly $14\\,000$ signal events, containing all possible intermediate resonances with a $K^+ \\pi^- \\pi^+$ final state in the $[1,2]\\, \\rm{GeV}/\\it{c}^2$ mass interval, are reconstructed and selected in the data sample. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of $K^+ \\pi^- \\pi^+$ mass and the...

  9. LHCb: Photon polarisation B in $b \\rightarrow s\\gamma$ using B $\\rightarrow$ K$^*$e$^+$e$^-$ at LHCb

    CERN Multimedia

    Nicol, Michelle

    2011-01-01

    Although the branching ratio of $b \\rightarrow s\\gamma$ has been measured to be consistent with that predicted by the Standard Model, new physics could still be present and detectable through analysing details of the decay process. In particular, the photon from the b is predominantly left handed in the SM, whereas additional right handed currents can arise in certain classes of new physics models. Access to the polarisation information is available via an angular analysis of $B \\rightarrow K^*e^+e^-$. Hadronic form factors render theoretical predictions over the whole $q^2$ (the dilepton invariant mass squared) range difficult . However, it has been shown that at low $q^2$, certain asymmetries providing information on the photon polarisation can be formed, where these uncertainties are controllable. This poster will present an overview of the method to measure the photon polarisation at the LHCb experiment at CERN by performing an angular analysis of $B \\rightarrow K^*e^+e^-$ at low $q^2$.

  10. Arbitrary photonic wave plate operations on chip: realizing Hadamard, Pauli-X, and rotation gates for polarisation qubits.

    Science.gov (United States)

    Heilmann, René; Gräfe, Markus; Nolte, Stefan; Szameit, Alexander

    2014-02-18

    Chip-based photonic quantum computing is an emerging technology that promises much speedup over conventional computers at small integration volumes. Particular interest is thereby given to polarisation-encoded photonic qubits, and many protocols have been developed for this encoding. However, arbitrary wave plate operation on chip are not available so far, preventing from the implementation of integrated universal quantum computing algorithms. In our work we close this gap and present Hadamard, Pauli-X, and rotation gates of high fidelity for photonic polarisation qubits on chip by employing a reorientation of the optical axis of birefringent waveguides. The optical axis of the birefringent waveguide is rotated due to the impact of an artificial stress field created by an additional modification close to the waveguide. By adjusting this length of the defect along the waveguide, the retardation between ordinary and extraordinary field components is precisely tunable including half-wave plate and quarter-wave plate operations. Our approach demonstrates the full range control of orientation and strength of the induced birefringence and thus allows arbitrary wave plate operations without affecting the degree of polarisation or introducing additional losses to the waveguides. The implemented gates are tested with classical and quantum light.

  11. Polarisation confirmed

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    The polarisation of photons emitted in the decay of a bottom quark into a strange quark, as predicted by the Standard Model, has just been observed for the first time by the LHCb collaboration. More detailed research is still required to determine the value of this polarisation with precision.   In this LHCb event, K, π and γ are emitted from a B+ → K+π-π+γ decay. This was investigated by the LHCb collaboration in order to study the photon (γ) polarisation.   If we imagine that photons are like little spinning tops which spin around an axis aligned with their direction of propagation, we can identify two types of photons. Those that are “right-handed” turn in the same direction as a corkscrew, and those that are “left-handed” turn in the opposite direction. If for a large number of decays of a given type we can observe an imbalance between the production of right-han...

  12. Photon Linear Collider Gamma-Gamma Summary

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J

    2012-02-27

    High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

  13. A new Bayesian formulation to integrate body-wave polarisation in non-linear probabilistic earthquake location

    Science.gov (United States)

    Gaucher, Emmanuel; Gesret, Alexandrine; Noble, Mark; Kohl, Thomas

    2016-04-01

    Earthquake location is most of the time computed using the arrival time of the seismic waves observed on monitoring networks. However, three-component seismometers enable measurement of the seismic wave polarisation which is also hypocentre dependent. This information is necessary when considering single-station locations but may also be applied to local and sparse seismic networks with poor coverage to better constrain the local earthquake hypocentres, as typically seen in hydraulic fracturing or geothermal field monitoring. In this work, we propose a new Bayesian formulation that integrates the information associated with the P-wave polarisation into a probabilistic earthquake location scheme. The approach takes a single 3C-sensor perspective and uses the covariance matrix to quantify the polarisation. This matrix contains all necessary axial information including uncertainties. According to directional statistics, the tri-variate Gaussian distribution represented by the covariance matrix corresponds to an angular central Gaussian distribution when axial data are considered. This property allows us defining a simple probability density function associated with a modelled polarisation vector given the observed covariance matrix. With this approach, the non-linearity of the location problem is kept. Unlike existing least-square misfit functions, this formulation does not reduce the polarisation to a single axis and avoids inexact estimate of a priori angular uncertainties. Furthermore, it replaces the polarisation information in the spherical data space, which yields correct probability density normalisation and prevents from any weighting when combined with e.g. travel-time probability density function. We first present the Bayesian formalism. Then, several synthetic tests on a 1D velocity model are performed to illustrate the technique and to show the effect of integrating the polarisation information. In this synthetic test, we also compare the results with an

  14. A two-qubit photonic quantum processor and its application to solving systems of linear equations.

    Science.gov (United States)

    Barz, Stefanie; Kassal, Ivan; Ringbauer, Martin; Lipp, Yannick Ole; Dakić, Borivoje; Aspuru-Guzik, Alán; Walther, Philip

    2014-08-19

    Large-scale quantum computers will require the ability to apply long sequences of entangling gates to many qubits. In a photonic architecture, where single-qubit gates can be performed easily and precisely, the application of consecutive two-qubit entangling gates has been a significant obstacle. Here, we demonstrate a two-qubit photonic quantum processor that implements two consecutive CNOT gates on the same pair of polarisation-encoded qubits. To demonstrate the flexibility of our system, we implement various instances of the quantum algorithm for solving of systems of linear equations.

  15. Photon Propagation through Linearly Active Dimers

    Directory of Open Access Journals (Sweden)

    José Delfino Huerta Morales

    2017-06-01

    Full Text Available We provide an analytic propagator for non-Hermitian dimers showing linear gain or losses in the quantum regime. In particular, we focus on experimentally feasible realizations of the PT -symmetric dimer and provide their mean photon number and second order two-point correlation. We study the propagation of vacuum, single photon spatially-separable, and two-photon spatially-entangled states. We show that each configuration produces a particular signature that might signal their possible uses as photon switches, semi-classical intensity-tunable sources, or spatially entangled sources to mention a few possible applications.

  16. Linear-Optic Heralded Photon Source

    OpenAIRE

    da Silva, Thiago Ferreira; Amaral, Gustavo C; Temporão, Guilherme P.; von der Weid, Jean Pierre

    2015-01-01

    We present a Heralded Photon Source based only on linear optics and weak coherent states. By time-tuning a Hong-Ou-Mandel interferometer fed with frequency-displaced coherent states, the output photons can be synchronously heralded following sub-Poisson statistics, which is indicated by the second-order correlation function ($g^2\\left(0\\right)=0.556$). The absence of phase-matching restrictions makes the source widely tunable, with 100-nm spectral tunability on the telecom bands. The techniqu...

  17. Linear-optic heralded photon source

    Science.gov (United States)

    Ferreira da Silva, Thiago; Amaral, Gustavo C.; Temporão, Guilherme P.; von der Weid, Jean Pierre

    2015-09-01

    We present a heralded photon source based only on linear optics and weak coherent states. By time-tuning a Hong-Ou-Mandel interferometer fed with frequency-displaced coherent states, the output photons can be synchronously heralded following sub-Poisson statistics, which is indicated by the second-order correlation function [ g2(0 )=0.556 ]. The absence of phase-matching restrictions makes the source widely tunable, with 100-nm spectral tunability on the telecom bands. The technique presents yield comparable to state-of-the-art spontaneous parametric down-conversion-based sources, with high coherence and fiber-optic quantum communication compatibility.

  18. Mapping the broadband polarization properties of linear 2D SOI photonic crystal waveguides

    DEFF Research Database (Denmark)

    Canning, John; Skivesen, Nina; Kristensen, Martin;

    2007-01-01

    cut-off. We also observe relatively broadband mixing between the two eigenstates to generate a complete photonic bandgap. By careful analysis of the output polarisation state we report on an inherent non-reciprocity between quasi TE and TM fundamental mode cross coupling. The nature of polarisation...

  19. POLARISATION PRESERVING OPTICAL FIBRE

    DEFF Research Database (Denmark)

    2000-01-01

    . This cladding structure provides polarisation preserving properties to the optical fibre. Optical fibres using this technology may have claddings with elements placed non-periodically as well as in a two-dimensional periodic lattice - such as cladding providing Photonic Band Gap (PBG) effects....

  20. Linearly polarized photons at MAMI (Mainz)

    Science.gov (United States)

    Lohmann, D.; Peise, J.; Ahrens, J.; Anthony, I.; Arends, H.-J.; Beck, R.; Crawford, R.; Hünger, A.; Kaiser, K. H.; Kellie, J. D.; Klümper, Ch.; Krahn, P.; Kraus, A.; Ludwig, U.; Schumacher, M.; Selke, O.; Schmitz, M.; Schneider, M.; Wissmann, F.; Wolf, S.

    1994-04-01

    Coherent bremsstrahlung is produced using the 855 MeV electron beam of the Mainz three-stage racetrack microtron MAMI and a diamond crystal inserted as a radiator into the MAMI tagging system. By counting only the electrons on the tagger ladder an intensity spectrum ranging from 50 MeV to 800 MeV was obtained with good statistical accuracy in a running time of 2 s. This short running time makes it possible to measure a complete intensity pattern versus photon energy for different orientations of the diamond crystal in about 15 minutes. By comparing these measured intensity patterns with calculations it becomes possible to precisely align the crystal axes with respect to the axes of the goniometer. Relative intensities of coherent bremsstrahlung are determined experimentally by normalizing the diamond data to data obtained with an amorphous Ni radiator. Good agreement is obtained between experiment and prediction when taking into account the beam divergence, multiple scattering of electrons in the radiator, the Z dependence of the bremsstrahlung spectrum and the finite Debye temperature of diamond. With a collimated photon beam having an aperture of half the characteristic angle degrees of linear polarization appear to be possible ranging from 80% at 200 MeV over 65% at 300 MeV and 55% at 400 MeV to 35% at 500 MeV.

  1. Mapping the broadband polarization properties of linear 2D SOI photonic crystal waveguides.

    Science.gov (United States)

    Canning, John; Skivesen, Nina; Kristensen, Martin; Frandsen, Lars H; Lavrinenko, Andrei; Martelli, Cicero; Tetu, A

    2007-11-12

    Both quasi-TE and TM polarisation spectra for a silicon-on-insulator (SOI) waveguide are recorded over (1100-1700)nm using a broadband supercontinuum source. By studying both the input and output polarisation eigenstates we observe narrowband resonant cross coupling near the lowest quasi-TE mode cut-off. We also observe relatively broadband mixing between the two eigenstates to generate a complete photonic bandgap. By careful analysis of the output polarisation state we report on an inherent non-reciprocity between quasi TE and TM fundamental mode cross coupling. The nature of polarisation distinction in such bandgap structures is discussed in the context of polarisation scattering at an interface.

  2. AGATA modules as Compton polarimeters for the measurement of gamma-ray linear polarisation

    Directory of Open Access Journals (Sweden)

    Melon B.

    2014-03-01

    Full Text Available The ability of a cluster of three segmented Ge crystals (“AGATA module” acting as a Compton polarimeter to measure the linear polarization of gamma rays has been investigated at an energy close to 511 keV. Partially polarized gamma rays have been produced by Coulomb excitation of the first excited state of 104Pd a and 108Pd.

  3. XTE J1752-223 in outburst: a persistent radio jet, dramatic flaring, multiple ejections and linear polarisation

    CERN Document Server

    Brocksopp, Catherine; Tzioumis, Tasso; Broderick, Jess; Rodriguez, Jerome; Yang, Jun; Fender, Rob; Paragi, Zsolt

    2013-01-01

    The black hole candidate, XTE J1752-223, was discovered in 2009 October when it entered an outburst. We obtained radio data from the Australia Telescope Compact Array for the duration of the ~9 month event. The lightcurves show that the radio emission from the compact jet persisted for the duration of an extended hard state and through the transition to the intermediate state. The flux then rose rapidly by a factor of 10 and the radio source entered a series of at least 7 maxima, the first of which was likely to be emission associated with the compact jet. The subsequent 6 flares were accompanied by variable behaviour in terms of radio spectrum, degree of linear polarisation, morphology and associated X-ray behaviour. They were, however, remarkably similar in terms of the estimated minimum power required to launch such an ejection event. We compare the timing of radio peaks with the location of the ejecta, imaged by contemporaneous VLBI experiments. We then discuss the mechanism behind the events, in terms of...

  4. Polarised Raman and infrared spectral analysis of L-alanine oxalate (C5H9NO6)--a non-linear optical single crystal.

    Science.gov (United States)

    Krishnakumar, V; Nagalakshmi, R

    2006-06-01

    L-alanine oxalate (C5H9NO6), a promising material for effective frequency conversion, was grown by standard slow evaporation technique. Solubility studies were carried out at different temperatures. Unambiguous assignments of fundamental modes of various molecular groups were made from the recorded infrared and polarised Raman spectra. The non-linear optical property has been confirmed from the optical transmission and fluorescence spectra.

  5. Measurement of polarisation observables in Ks0Σ+ photoproduction off the proton

    Directory of Open Access Journals (Sweden)

    R. Ewald

    2014-11-01

    Full Text Available The reaction γp→KS0Σ+ is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to Eγ=1650MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay Σ+→pπ0 up to Eγ=2250MeV. The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed prominent structure in the cross section near the K⁎ thresholds is discussed.

  6. Measurement of polarisation observables in $K^0_s\\Sigma^+$ photoproduction off the proton

    CERN Document Server

    Ewald, R; Bantes, B; Bartholomy, O; Bayadilov, D; Beck, R; Beloglazov, Y A; Brinkmann, K -T; Crede, V; Dutz, H; Elsner, D; Fornet-Ponse, K; Frommberger, F; Funke, Ch; Gridnev, A B; Gutz, E; Hannappel, J; Hillert, W; Hoffmeister, P; Jaegle, I; Jahn, O; Jude, T C; Junkersfeld, J; Kalinowsky, H; Kammer, S; Kleber, V; Klein, Frank; Klein, Friedrich; Klempt, E; Krusche, B; Lang, M; Löhner, H; Lopatin, I V; Menze, D; Mertens, T; Messchendorp, J G; Metag, V; Nanova, M; Nikonov, V A; Novinski, D; Novotny, R; Ostrick, M; Pant, L; van Pee, H; Roy, A; Sarantsev, A V; Schadmand, S; Schmidt, C; Schmieden, H; Schoch, B; Shende, S; Sokhoyan, V; Süle, A; Sumachev, V V; Szczepanek, T; Thoma, U; Trnka, D; Varma, R; Walther, D; Wendel, Ch

    2014-01-01

    The reaction $\\gamma \\, p \\rightarrow K^0_S\\,\\Sigma^+$ is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to $E_\\gamma = 2250$ MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay $\\Sigma^+ \\rightarrow p \\pi^0$ up to $E_\\gamma = 1650$ MeV. The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed cusp-like structure near the $K^*$ thresholds is discussed.

  7. Measurement of polarisation observables in Ks0 Σ+ photoproduction off the proton

    Science.gov (United States)

    Ewald, R.; Anisovich, A. V.; Bantes, B.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Brinkmann, K.-T.; Crede, V.; Dutz, H.; Elsner, D.; Fornet-Ponse, K.; Frommberger, F.; Funke, Ch.; Gridnev, A. B.; Gutz, E.; Hannappel, J.; Hillert, W.; Hoffmeister, P.; Jaegle, I.; Jahn, O.; Jude, T. C.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Kleber, V.; Klein, Frank; Klein, Friedrich; Klempt, E.; Krusche, B.; Lang, M.; Löhner, H.; Lopatin, I. V.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Nanova, M.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L.; van Pee, H.; Roy, A.; Sarantsev, A. V.; Schadmand, S.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Sokhoyan, V.; Süle, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch.

    2014-11-01

    The reaction γp → KS0 Σ+ is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to Eγ = 1650MeV. In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay Σ+ → pπ0 up to Eγ = 2250MeV. The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed prominent structure in the cross section near the K* thresholds is discussed.

  8. Linear-optics manipulations of photon-loss codes

    CERN Document Server

    Banaszek, K; Banaszek, Konrad; Wasilewski, Wojciech

    2007-01-01

    We discuss codes for protecting logical qubits carried by optical fields from the effects of amplitude damping, i.e. linear photon loss. We demonstrate that the correctability condition for one-photon loss imposes limitations on the range of manipulations than can be implemented with passive linear-optics networks.

  9. The secret world of shrimps: polarisation vision at its best

    CERN Document Server

    Kleinlogel, Sonja

    2008-01-01

    Animal vision spans a great range of complexity, with systems evolving to detect variations in optical intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. Polarisation is fully measured via Stokes' parameters--obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes' parameters: here we show that the crustacean \\emph{Gonodactylus smithii} measures the exact components required. This vision provides optimal contrast-enhancement, and precise determination of polarisation with no confusion-states or neutral-points--significant advantages. We emphasise that linear and circular polarisation vision are not different modalities--both are necessary for optimal polarisation vis...

  10. The secret world of shrimps: polarisation vision at its best.

    Directory of Open Access Journals (Sweden)

    Sonja Kleinlogel

    Full Text Available BACKGROUND: Animal vision spans a great range of complexity, with systems evolving to detect variations in light intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. METHODOLOGY/PRINCIPAL FINDINGS: Polarisation is fully measured via Stokes' parameters--obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes' parameters: here we show that the crustacean Gonodactylus smithii measures the exact components required. CONCLUSIONS/SIGNIFICANCE: This vision provides optimal contrast-enhancement and precise determination of polarisation with no confusion states or neutral points--significant advantages. Linear and circular polarisation each give partial information about the polarisation of light--but the combination of the two, as we will show here, results in optimal polarisation vision. We suggest that linear and circular polarisation vision not be regarded as different modalities, since both are necessary for optimal polarisation vision; their combination renders polarisation vision independent of strongly linearly or circularly polarised features in the animal's environment.

  11. A two-qubit photonic quantum processor and its application to solving systems of linear equations

    OpenAIRE

    Stefanie Barz; Ivan Kassal; Martin Ringbauer; Yannick Ole Lipp; Borivoje Dakić; Alán Aspuru-Guzik; Philip Walther

    2014-01-01

    Large-scale quantum computers will require the ability to apply long sequences of entangling gates to many qubits. In a photonic architecture, where single-qubit gates can be performed easily and precisely, the application of consecutive two-qubit entangling gates has been a significant obstacle. Here, we demonstrate a two-qubit photonic quantum processor that implements two consecutive CNOT gates on the same pair of polarisation-encoded qubits. To demonstrate the flexibility of our system, w...

  12. Linear and interface defects in composite linear photonic lattice

    Science.gov (United States)

    Stojanović Krasić, Marija; Mančić, Ana; Kuzmanović, Slavica; Đorić Veljković, Snežana; Stepić, Milutin

    2017-07-01

    We numerically analysed various localized modes formed by light beam propagation through one-dimensional composite lattices consisting of two structurally different linear lattices and a linear defect (LD) in one of them. The localized modes are found in the area between the interface and the LD, near the interface and around the LD. It has been confirmed that a LD narrower than the other waveguides (WGs) in the array is better potential barrier and captures the light better than a LD that is wider than the other WGs in the array. Also, it has been shown that a LD narrower than the other WGs in the lattice captures the light more efficiently than any saturable nonlinear defect (ND) of the same width as other elements of the lattice. On the other hand, it is obtained that the influence of a LD wider than the other WGs in the array on light propagation can be mimicked by insertion of an adequate ND whose width coincides with that of the other WGs. Depending on the defect size, its position and input beam parameters, controllable beam trapping, reflection and refraction are observed.

  13. Polarisation of Class II Methanol Masers

    CERN Document Server

    Stack, P D

    2011-01-01

    We have used the University of Tasmania Mt Pleasant 26m radio telescope to investigate the polarisation characteristics of a sample of strong 6.7 GHz methanol masers, the first spectral line polarisation observations to be undertaken with this instrument. As part of this process we have developed a new technique for calibrating linear polarisation spectral line observations. This calibration method gives results consistent with more traditional techniques, but requires much less observing time on the telescope. We have made the first polarisation measurements of a number of 6.7 GHz methanol masers and find linear polarisation at levels of a few - 10% in most of the sources we observed, consistent with previous results. We also investigated the circular polarisation produced by Zeeman splitting in the 6.7 GHz methanol maser G9.62+0.20 to get an estimate of the line of sight magnetic field strength of 35+/-7 mG.

  14. Conditional linear-optical measurement schemes generate effective photon nonlinearities

    CERN Document Server

    Lapaire, G G; Dowling, J P; Sipe, J E; Dowling, Jonathan P.

    2003-01-01

    We provide a general approach for the analysis of optical state evolution under conditional measurement schemes, and identify the necessary and sufficient conditions for such schemes to simulate unitary evolution on the freely propagating modes. If such unitary evolution holds, an effective photon nonlinearity can be identified. Our analysis extends to conditional measurement schemes more general than those based solely on linear optics.

  15. Linearly polarized photon beam at MAX-lab

    Energy Technology Data Exchange (ETDEWEB)

    Ganenko, V., E-mail: ganenko@kipt.kharkov.ua [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Brudvik, J. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Burdeinyi, D. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Fissum, K. [Department of Physics, Lund University, SE-221 00 Lund (Sweden); Hansen, K. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Isaksson, L. [Department of Physics, Lund University, SE-221 00 Lund (Sweden); Livingston, K. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Lundin, M. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Morokhovskii, V. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Nilsson, B.; Pugachov, D. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Schroder, B. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Department of Physics, Lund University, SE-221 00 Lund (Sweden); Vashchenko, G. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine)

    2014-11-01

    A linearly polarized photon beam has been produced at MAX-lab using the coherent bremsstrahlung of electrons with an energy of 192.6 MeV in a 0.1 mm thick diamond crystal. The intensity and shape of the coherent maxima and their dependence on the crystal orientation are similar to the features observed at higher electron energies (∼ 1 GeV) and are well described by coherent bremsstrahlung theory. The linear polarization of the uncollimated beam at the coherent peak energy ≈50–60 MeV is about 20% and can be increased to 40–45% if collimation of half the characteristic angle is used. At present the degree of polarization is high enough to allow the study of polarization observables in photo-nuclear reactions at MAX-lab in the energy range from Giant Dipole Resonance up to ≈80 MeV. -- Highlights: •A linearly polarized tagged photon beam has been produced at the MAX-lab facility. •The coherent bremsstrahlung spectra were measured for various crystal orientations. •The measured spectra are well described by the coherent bremsstrahlung theory. •The photon beam polarization can reach 50% at the Giant Resonance region. •Polarized beam provides performing nuclear experiments in the energy range 10–90 MeV.

  16. Tunable photonic band-gaps in one-dimensional photonic crystals containing linear graded index material

    Science.gov (United States)

    Singh, Bipin K.; Kumar, Pawan; Pandey, Praveen C.

    2014-12-01

    We have demonstrated control of the photonic band gaps (PBGs) in 1-D photonic crystals using linear graded index material. The analysis of PBG has been done in THz region by considering photonic crystals in the form of ten periods of second, third and fourth generation of the Fibonacci sequence as unit cell. The unit cells are constituted of two kinds of layers; one is taken of linear graded index material and other of normal dielectric material. For this investigation, we used a theoretical model based on transfer matrix method. We have obtained a large number of PBGs and their bandwidths can be tuned by changing the grading profile and thicknesses of linear graded index layers. The number of PBGs increases with increase in the thicknesses of layers and their bandwidths can be controlled by the contrast of initial and final refractive index of the graded layers. In this way, we provide more design freedom for photonic devices such as reflectors, filters, optical sensors, couplers, etc.

  17. Social polarisation in Aarhus

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild

    2009-01-01

    This paper is connected to the phd. project: “Social polarisation in Aarhus” and will discuss the concept of social polarisation and related concepts as poverty, marginalization and social exclusion in developing a research strategy in studying social polarisation in the city....

  18. The effects of spin-dependent interactions on polarisation of bright polariton solitons

    CERN Document Server

    Sich, M; Chana, J K; Skolnick, M S; Krizhanovskii, D N; Gorbach, A V; Hartley, R; Skryabin, D V; Gavrilov, S V; Cerda-Mendez, E A; Biermann, K; Hey, R; Santos, P V

    2013-01-01

    We report on the spin properties of bright polariton solitons supported by an external pump to compensate losses. We observe robust circularly polarised solitons when a circularly polarised pump is applied, a result attributed to phase synchronisation between nondegenerate TE and TM polarised polariton modes at high momenta. For the case of a linearly polarised pump either s+ or s- circularly polarised bright solitons can be switched on in a controlled way by a s+ or s- writing beam respectively. This feature arises directly from the widely differing interaction strengths between co- and cross-circularly polarised polaritons. In the case of orthogonally linearly polarised pump and writing beams, the soliton emission on average is found to be unpolarised, suggesting strong spatial evolution of the soliton polarisation, a conclusion supported by polarisation correlation measurements. The observed results are in agreement with theory, which predicts stable circularly polarised solitons and unstable linearly pola...

  19. Concepts for polarising sheets & "dual-gridded" reflectors for circular polarisation

    NARCIS (Netherlands)

    Albani, M.; Balling, P.; Datashvili, L.; Gerini, G.; Ingvarson, P.; Pontoppidan, K.; Sabbadini, M.; Sjöberg, D.; Skokic, S.; Vecchi, G.

    2010-01-01

    C-, Ku- and Ka-band communications and broadcast satellites use so-called dual-gridded reflector antennas for linear polarisation to provide independent reflector surfaces and/or independent feeds for the two orthogonal polarisations. This paper describes initial work to extend this concept to circu

  20. Fission of heavy nuclei by linearly polarized photons

    CERN Document Server

    Khvastunov, V M; Kasyan, S V; Likhachev, V P; Paschuk, S A

    2002-01-01

    Analysing power SIGMA data from photofission of sup 2 sup 3 sup 2 Th, sup 2 sup 3 sup 3 U, sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 6 U, sup 2 sup 3 sup 8 U at the region of giant resonance have been measured using linearly polarized photons. The polarized photons were obtained by plane channelling of electrons in a silicon single crystal. The analysing power SIGMA dependence of the mass number of even-even nucleus has been discovered. Comparison of the analysing power SIGMA values with the data from other experiments with both polarized and unpolarized photon beams was made. It is shown that the analysing power SIGMA values agree with the modern knowledge of E1 transitions but cannot be explain by domination any one of them. It is supposed that analysing power SIGMA is very sensitive to different relative inner and outer fission barrier heights and this affects on SIGMA values for even-even nuclei with the same Z.

  1. Coherent integrated receiver for highly linear microwave photonic links

    Science.gov (United States)

    Klamkin, Jonathan

    Phase modulation can be used to improve the signal-to-noise ratio and spurfree dynamic range (SFDR) of microwave photonic links because phase modulation is not limited in input modulation swing and is inherently linear using certain electro-optic devices. Traditional interferometer-based phase demodulators have a sinusoidal response therefore a novel approach is required for achieving linear coherent detection at the receive end of a photonic link employing phase modulation. In this work, a balanced receiver with feedback to a reference tracking phase modulator was developed. With sufficient feedback loop gain, the received signal phase is closely tracked and the phase detection falls within the linear regime of the interferometer response. For stable operation at high frequency the delay of the feedback loop must be kept short, therefore a monolithic approach is required to realize a compact receiver architecture. The monolithic photonic integrated circuit (PIC) developed here consists of a high power balanced uni-traveling-carrier photodiode (UTC-PD), a compact 2x2 multimode interference (MMI) coupler, and multi-quantum well reference phase modulators. This PIC is hybrid integrated with an electronic IC that provides transconductance amplification of the feedback signal for increased loop gain. Novel concepts such as charge compensation, partially depleted absorption, and absorption profile modification were incorporated into the design of the waveguide UTCPDs resulting in record output saturation current and linearity. Both general interference surface ridge (SR) MMI couplers and restricted interference deep ridge (DR) MMI couplers were explored, the latter for reducing the loop delay. Current injection tuning was incorporated into the MMI couplers for fine tuning the output power splitting ratio. The quantum well design of the reference phase modulators was optimized for realizing low Vpi, low insertion loss, low absorption modulation, and improved linearity

  2. Scheme for Realizing Probabilistic Teleportation of Bipartite Photonic States via Linear Optical Elements

    Institute of Scientific and Technical Information of China (English)

    DONG Ping; LIN Ji-Cheng; YANG Ming; CAO Zhuo-Liang

    2006-01-01

    We propose a probabilistic scheme for realizing teleportation of bipartite photonic states using linear optical elements where only requires a two-photon Bell state used as quantum channel. It reduces the requirement of the entanglement of quantum channel, but requires an additional photon and an auxiliary maximally entangled photon pair locally.

  3. Robopol: Optical polarisation monitoring of blazars

    CERN Document Server

    Angelakis, Emmanouil; Böttcher, Markus; Hovatta, Talvikki; Kiehlmann, Sebastian; Myserlis, Ioannis; Pavlidou, Vassiliki; Zensus, J Anton

    2016-01-01

    The RoboPol program has been monitoring the $R$-band linear polarisation parameters of an unbiased sample of 60 gamma-ray-loud blazars and a "control" sample of 15 gamma-ray-quite ones. The prime drive for the program has been the systematic study of the temporal behaviour of the optical polarisation and particularly the potential association of smooth and long rotations of the polarisation angle with flaring activity at high energies. Here we present the program and discuss a list of selected topics from our studies of the first three observing seasons (2013--2015) both in the angle and in the amplitude domain.

  4. Polarisation vision: beetles see circularly polarised light.

    Science.gov (United States)

    Warrant, Eric J

    2010-07-27

    It has long been known that the iridescent cuticle of many scarab beetles reflects circularly polarised light. It now turns out that scarabs can also see this light, potentially using it as a covert visual signal.

  5. First polarised light with the NIKA camera

    CERN Document Server

    Ritacco, A; Adane, A; Ade, P; André, P; Beelen, A; Belier, B; Benoît, A; Bideaud, A; Billot, N; Bourrion, O; Calvo, M; Catalano, A; Coiffard, G; Comis, B; D'Addabbo, A; Désert, F -X; Doyle, S; Goupy, J; Kramer, C; Leclercq, S; Macías-Pérez, J F; Martino, J; Mauskopf, P; Maury, A; Mayet, F; Monfardini, A; Pajot, F; Pascale, E; Perotto, L; Pisano, G; Ponthieu, N; Rebolo-Iglesias, M; Réveret, V; Rodriguez, L; Savini, G; Schuster, K; Sievers, A; Thum, C; Triqueneaux, S; Tucker, C; Zylka, R

    2015-01-01

    NIKA is a dual-band camera operating with 315 frequency multiplexed LEKIDs cooled at 100 mK. NIKA is designed to observe the sky in intensity and polarisation at 150 and 260 GHz from the IRAM 30-m telescope. It is a test-bench for the final NIKA2 camera. The incoming linear polarisation is modulated at four times the mechanical rotation frequency by a warm rotating multi-layer Half Wave Plate. Then, the signal is analysed by a wire grid and finally absorbed by the LEKIDs. The small time constant (< 1ms ) of the LEKID detectors combined with the modulation of the HWP enables the quasi-simultaneous measurement of the three Stokes parameters I, Q, U, representing linear polarisation. In this pa- per we present results of recent observational campaigns demonstrating the good performance of NIKA in detecting polarisation at mm wavelength.

  6. First Polarised Light with the NIKA Camera

    Science.gov (United States)

    Ritacco, A.; Adam, R.; Adane, A.; Ade, P.; André, P.; Beelen, A.; Belier, B.; Benoît, A.; Bideaud, A.; Billot, N.; Bourrion, O.; Calvo, M.; Catalano, A.; Coiffard, G.; Comis, B.; D'Addabbo, A.; Désert, F.-X.; Doyle, S.; Goupy, J.; Kramer, C.; Leclercq, S.; Macías-Pérez, J. F.; Martino, J.; Mauskopf, P.; Maury, A.; Mayet, F.; Monfardini, A.; Pajot, F.; Pascale, E.; Perotto, L.; Pisano, G.; Ponthieu, N.; Rebolo-Iglesias, M.; Revéret, V.; Rodriguez, L.; Savini, G.; Schuster, K.; Sievers, A.; Thum, C.; Triqueneaux, S.; Tucker, C.; Zylka, R.

    2016-08-01

    NIKA is a dual-band camera operating with 315 frequency multiplexed LEKIDs cooled at 100 mK. NIKA is designed to observe the sky in intensity and polarisation at 150 and 260 GHz from the IRAM 30-m telescope. It is a test-bench for the final NIKA2 camera. The incoming linear polarisation is modulated at four times the mechanical rotation frequency by a warm rotating multi-layer half- wave plate. Then, the signal is analyzed by a wire grid and finally absorbed by the lumped element kinetic inductance detectors (LEKIDs). The small time constant (ms ) of the LEKIDs combined with the modulation of the HWP enables the quasi-simultaneous measurement of the three Stokes parameters I, Q, U, representing linear polarisation. In this paper, we present the results of recent observational campaigns demonstrating the good performance of NIKA in detecting polarisation at millimeter wavelength.

  7. Update on Linear Mode Photon Counting with the HgCdTe Linear Mode Avalanche Photodiode

    Science.gov (United States)

    Beck, Jeffrey D.; Kinch, Mike; Sun, Xiaoli

    2014-01-01

    The behavior of the gain-voltage characteristic of the mid-wavelength infrared cutoff HgCdTe linear mode avalanche photodiode (e-APD) is discussed both experimentally and theoretically as a function of the width of the multiplication region. Data are shown that demonstrate a strong dependence of the gain at a given bias voltage on the width of the n- gain region. Geometrical and fundamental theoretical models are examined to explain this behavior. The geometrical model takes into account the gain-dependent optical fill factor of the cylindrical APD. The theoretical model is based on the ballistic ionization model being developed for the HgCdTe APD. It is concluded that the fundamental theoretical explanation is the dominant effect. A model is developed that combines both the geometrical and fundamental effects. The model also takes into account the effect of the varying multiplication width in the low bias region of the gain-voltage curve. It is concluded that the lower than expected gain seen in the first 2 × 8 HgCdTe linear mode photon counting APD arrays, and higher excess noise factor, was very likely due to the larger than typical multiplication region length in the photon counting APD pixel design. The implications of these effects on device photon counting performance are discussed.

  8. Update on Linear Mode Photon Counting with the HgCdTe Linear Mode Avalanche Photodiode

    Science.gov (United States)

    Beck, Jeffrey D.; Kinch, Mike; Sun, Xiaoli

    2014-01-01

    The behavior of the gain-voltage characteristic of the mid-wavelength infrared cutoff HgCdTe linear mode avalanche photodiode (e-APD) is discussed both experimentally and theoretically as a function of the width of the multiplication region. Data are shown that demonstrate a strong dependence of the gain at a given bias voltage on the width of the n- gain region. Geometrical and fundamental theoretical models are examined to explain this behavior. The geometrical model takes into account the gain-dependent optical fill factor of the cylindrical APD. The theoretical model is based on the ballistic ionization model being developed for the HgCdTe APD. It is concluded that the fundamental theoretical explanation is the dominant effect. A model is developed that combines both the geometrical and fundamental effects. The model also takes into account the effect of the varying multiplication width in the low bias region of the gain-voltage curve. It is concluded that the lower than expected gain seen in the first 2 × 8 HgCdTe linear mode photon counting APD arrays, and higher excess noise factor, was very likely due to the larger than typical multiplication region length in the photon counting APD pixel design. The implications of these effects on device photon counting performance are discussed.

  9. Polarised Geant4 - Applications at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Schaelicke, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Laihem, K. [RWTH Aachen (Germany). III. Physikalisches Inst. B; Starovoitov, P. [NCPHEP BSU, Minsk (Belarus)

    2007-11-15

    Geant4 is a Monte Carlo simulation framework for the description of interactions of particles and matter. Starting with version 8.2 a new package of QED physics processes is available, allowing for the studies of interactions of polarised particles with polarised media dedicated to beam applications. In this contribution some details about the implementation are presented and applications to the linear collider are discussed. (orig.)

  10. Polarised Geant4 - Applications at the ILC

    OpenAIRE

    Schälicke, Andreas; Laihem, Karim; Starovoitov, Pavel

    2007-01-01

    Geant4 is a Monte Carlo simulation framework for the description of interactions of particles and matter. Starting with version 8.2 a new package of QED physics processes is available, allowing for the studies of interactions of polarised particles with polarised media dedicated to beam applications. In this contribution some details about the implementation are presented and applications to the linear collider are discussed.

  11. Photonics linear and nonlinear interactions of laser light and matter

    CERN Document Server

    Menzel, R

    2007-01-01

    This book covers the fundamental properties and the description of single photons and light beams, experimentally and theoretically. It explains the essentials of linear interactions and most nonlinear interactions between light and matter in both the transparent and absorbing cases. It also provides a basic understanding of modern quantum optics and lasers, as well as the principles of nonlinear optical spectroscopy. It is self-consistent and enriched by a large number of calculated illustrations, examples, and descriptive tables. Graduate students in physics and electrical engineering, as well as other sciences, will find this book a thorough introduction to the field, while for lecturers and scientists it is a rich source of useful information and a ready-to-hand reference. The new edition has been thoroughly expanded and revised in all sections

  12. Linear polarization of gluons and photons in unpolarized collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pisano, Cristian; Boer, Daniël; Brodsky, Stanley J.; Buffing, Maarten G. A.; Mulders, Piet J.

    2013-10-01

    We study azimuthal asymmetries in heavy quark pair production in unpolarized electron-proton and proton-proton collisions, where the asymmetries originate from the linear polarization of gluons inside unpolarized hadrons. We provide cross section expressions and study the maximal asymmetries allowed by positivity, for both charm and bottom quark pair production. The upper bounds on the asymmetries are shown to be very large depending on the transverse momentum of the heavy quarks, which is promising especially for their measurements at a possible future Electron-Ion Collider or a Large Hadron electron Collider. We also study the analogous processes and asymmetries in muon pair production as a means to probe linearly polarized photons inside unpolarized protons. For increasing invariant mass of the muon pair the asymmetries become very similar to the heavy quark pair ones. Finally, we discuss the process dependence of the results that arises due to differences in color flow and address the problem with factorization in case of proton-proton collisions.

  13. Circular polarisation in AGN

    NARCIS (Netherlands)

    Macquart, JP

    2002-01-01

    We discuss the constraints that recent observations place on circular polarisation in AGN. In many sources the circular polarisation is variable on short timescales, indicating that it originates in compact regions of the sources. The best prospects for gleaning further information about circular po

  14. Few-photon Non-linearities in Nanophotonic Devices for Quantum Information Technology

    DEFF Research Database (Denmark)

    Nysteen, Anders

    In this thesis we investigate few-photon non-linearities in all-optical, on-chip circuits, and we discuss their possible applications in devices of interest for quantum information technology, such as conditional two-photon gates and single-photon sources. In order to propose efficient devices...

  15. Study of small partial-wave contributions in the neighbourhood of dominating resonance states of the proton by linearly polarized photons; Untersuchung kleiner Partialwellenbeitraege in der Naehe dominierender Resonanzzustaende des Protons mit linear polarisierten Photonen

    Energy Technology Data Exchange (ETDEWEB)

    Elsner, D.

    2007-04-15

    The reaction p(e, e'p){pi}{sup 0} has been studied at Q{sup 2}=0.2 (GeV/c){sup 2} in the region of W=1232 MeV. From measurements left and right of (vector)q cross section asymmetries {rho}{sub LT} have been obtained in forward {rho}{sub LT}({theta}{sub {pi}{sup 0}}{sup cm}=20 )=(-11.68{+-}2.36{sub stat}{+-}2.36{sub sys}) and backward {rho}{sub LT}({theta}{sub {pi}}{sub {sup 0}}{sup cm}=160)=(12.18{+-}0.27{sub stat}{+-}0.82{sub sys}) {pi}{sup 0} kinematics, from which R{l_brace}S{sub 1+}{sup *}M{sub 1+}{r_brace}/ vertical stroke M{sub 1+} vertical stroke {sup 2} and R{l_brace}S{sub 0+}{sup *}M{sub 1+}{r_brace}/ vertical stroke M{sub 1+} vertical stroke {sup 2} could be determined. Using linear polarised tagged photon beams of energy up to E{sub {gamma}}{approx_equal}1.5 GeV the photon beam asymmetry {sigma} has been measured in the reaction p((vector){gamma}, {eta})p. Based on coherent bremsstrahlung off a diamond crystal a maximum polarisation of P{sub {gamma}}=49% has been achieved at E{sub {gamma}}=1305 MeV. The beam asymmetry has been extracted from the azimuthal modulation of the cross section using both decay modes of the {eta} into two photons and 3{pi}{sup 0}. Large asymmetries up to 80% are observed, in agreement with previous measurements where already available. There is also agreement with standard model calculations. However, the required partial waves to describe the measurements differ significantly. (orig.)

  16. Measurement of double polarisation asymmetries in $\\omega$-photoproduction

    CERN Document Server

    Eberhardt, H; Schmieden, H; Anisovich, A V; Bantes, B; Bayadilov, D; Beck, R; Beloglazov, Yu; Bichow, M; Boese, S; Brinkmann, K -Th; Challand, Th; Crede, V; Diez, F; Drexler, P; Dutz, H; Elsner, D; Ewald, R; Fornet-Ponse, K; Friedrich, St; Frommberger, F; Funke, Ch; Gottschall, M; Gridnev, A; Gruener, M; Gutz, E; Hammann, Ch; Hannappel, J; Hartmann, J; Hillert, W; Hoffmeister, Ph; Honisch, Ch; Jaegle, I; Kaiser, D; Kalinowsky, H; Kalischewski, F; Kammer, S; Keshelashvili, I; Kleber, V; Klein, F; Klempt, E; Koop, K; Krusche, B; Kube, M; Lang, M; Lopatin, I; Maghrbi, Y; Makonyi, K; Metag, V; Meyer, W; Mueller, J; Nanova, M; Nikonov, V; Novotny, R; Piontek, D; Reeve, S; Reicherz, G; Rostomyan, T; Runkel, S; Sarantsev, A; Schaepe, St; Schmidt, Ch; Schmitz, R; Seifen, T; Sokhoyan, V; Sumachev, V; Thiel, A; Thoma, U; Urban, M; van Pee, H; Walther, D; Wendel, Ch; Wiedner, U; Wilson, A; Winnebeck, A

    2015-01-01

    The first measurements of the beam-target-helicity-asymmetries $E$ and $G$ in the photoproduction of $\\omega$-mesons off protons at the CBELSA/TAPS experiment are reported. $E$ ($G$) was measured using circularly (linearly) polarised photons and a longitudinally polarised target. $E$ was measured over the photon energy range from close to threshold ($E_\\gamma = 1108$~MeV) to $E_\\gamma = 2300$~MeV and $G$ at a single energy interval of $1108 < E_\\gamma <1300$~MeV. Both measurements cover the full solid angle. The observables $E$ and $G$ are highly sensitive to the contribution of baryon resonances, with $E$ acting as a helicity filter in the $s$-channel. The new results indicate significant $s$-channel resonance contributions together with contributions from $t$-channel exchange processes. A partial wave analysis reveals strong contributions from the partial waves with spin-parity $J^P=3/2^+, 5/2^+$, and $3/2^-$.

  17. Measurement of double polarisation asymmetries in ω-photoproduction

    Directory of Open Access Journals (Sweden)

    H. Eberhardt

    2015-11-01

    Full Text Available The first measurements of the beam-target-helicity-asymmetries E and G in the photoproduction of ω-mesons off protons at the CBELSA/TAPS experiment are reported. E (G was measured using circularly (linearly polarised photons and a longitudinally polarised target. E was measured over the photon energy range from close to threshold (Eγ=1108 MeV to Eγ=2300 MeV and G at a single energy interval of 1108

  18. A semiconductor photon-sorter

    CERN Document Server

    Bennett, A J; Ellis, D J P; Farrer, I; Ritchie, D A; Shields, A J

    2016-01-01

    Photons do not interact directly with each other, but conditional control of one beam by another can be achieved with non-linear optical media at high field intensities. It is exceedingly difficult to reach such intensities at the single photon level but proposals have been made to obtain effective interactions by scattering photons from single transitions. We report here effective interactions between photons created using a quantum dot weakly coupled to a cavity. We show that a passive single-photon non-linearity can modify the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and sort polarisation correlated photons from an uncorrelated stream using a single spin. These results pave the way for optical switches operated by single quanta of light.

  19. Statistics of polarisation matching

    NARCIS (Netherlands)

    Naus, H.W.L.; Zwamborn, A.P.M.

    2014-01-01

    The reception of electromagnetic signals depends on the polarisation matching of the transmitting and receiving antenna. The practical matching differs from the theoretical one because of the noise deterioration of the transmitted and eventually received electromagnetic field. In other applications,

  20. Linear Amplification of Optical Signal in Coupled Photonic Crystal Waveguides

    CERN Document Server

    Jandieri, Vakhtang

    2015-01-01

    We introduce a weakly coupled photonic crystal waveguide as a promising and realistic model for all-optical amplification. A symmetric pillar type coupled photonic crystal waveguide consisting of dielectric rods periodically distributed in a free space is proposed as all-optical amplifier. Using the unique features of the photonic crystals to control and guide the light, we have properly chosen the frequency at which only one mode (odd mode) becomes the propagating mode in the coupled photonic crystal waveguide, whereas another mode (even mode) is completely reflected from the guiding structure. Under this condition, the all-optical amplification is fully realized. The amplification coefficient for the continuous signal and the Gaussian pulse is calculated.

  1. Results on the Coherent Interaction of High Energy Electrons and Photons in Oriented Single Crystals

    CERN Document Server

    Apyan, A; Badelek, B; Ballestrero, S; Biino, C; Birol, I; Cenci, P; Connell, S H; Eichblatt, S; Fonseca, T; Freund, A; Gorini, B; Groess, R; Ispirian, K; Ketel, T; Kononets, Y V; López, A; Mangiarotti, A; Van Rens, B; Sellschop, J P Friedel; Shieh, M; Sona, P; Strakhovenko, V M; Uggerhøj, Erik; Uggerhøj, U; Ünel, G; Velasco, M; Vilakazi, Z Z; Wessely, O; Kononets, Yu.V.

    2005-01-01

    The CERN-NA-59 experiment examined a wide range of electromagnetic processes for multi-GeV electrons and photons interacting with oriented single crystals. The various types of crystals and their orientations were used for producing photon beams and for converting and measuring their polarisation. The radiation emitted by 178 GeV unpolarised electrons incident on a 1.5 cm thick Si crystal oriented in the Coherent Bremsstrahlung (CB) and the String-of-Strings (SOS) modes was used to obtain multi-GeV linearly polarised photon beams. A new crystal polarimetry technique was established for measuring the linear polarisation of the photon beam. The polarimeter is based on the dependence of the Coherent Pair Production (CPP) cross section in oriented single crystals on the direction of the photon polarisation with respect to the crystal plane. Both a 1 mm thick single crystal of Germanium and a 4 mm thick multi-tile set of synthetic Diamond crystals were used as analyzers of the linear polarisation. A birefringence ...

  2. Cascadable and reconfigurable photonic logic gates based on linear lightwave interference and non-linear phase erasure.

    Science.gov (United States)

    Larom, Bar; Nazarathy, Moshe; Rudnitsky, Arkady; Nevet, Amir; Zalevsky, Zeev

    2010-06-21

    Feasibility of cascading and reconfiguring a pair of linear-nonlinear all-optical logic gate structures is experimentally demonstrated using RF photonics. Progress in highly integrated O/E/O repeaters over Si/InP hybrid platforms enables large-scale reconfigurable gate arrays.

  3. Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence

    CERN Document Server

    Apyan, A; Badelek, B; Ballestrero, S; Biino, C; Birol, I; Cenci, P; Connell, S H; Eichblatt, S; Fonseca, T; Freund, A; Gorini, B; Groess, R; Ispirian, K; Ketel, T; Kononets, Yu V; López, A; Mangiarotti, A; Sellschop, J P Friedel; Shieh, M; Sona, P; Strakhovenko, V M; Uggerhøj, Erik; Uggerhøj, U; Van Rens, B; Velasco, M; Vilakazi, Z Z; Wessely, O; Ünel, G; Kononets, Yu.V.

    2003-01-01

    The cross section for coherent pair production by linearly polarised photons in the 20-170 GeV energy range was measured for photon aligned incidence on ultra-high quality diamond and germanium crystals. The theoretical description of coherent bremsstrahlung and coherent pair production phenomena is an area of active theoretical debate and development. However, under our experimental conditions, the theory predicted the combined cross section and polarisation experimental observables very well indeed. In macroscopic terms, our experiment measured a birefringence effect in pair production in a crystal. This study of this effect also constituted a measurement of the energy dependent linear polarisation of photons produced by coherent bremsstrahlung in aligned crystals. New technologies for manipulating high energy photon beams can be realised based on an improved understanding of QED phenomena at these energies. In particular, this experiment demonstrates an efficient new polarimetry technique. The pair product...

  4. Polarisation and Polarimetry at HERA

    CERN Document Server

    Sobloher, Blanka

    2012-01-01

    Longitudinal polarisation of the lepton beam is a key ingredient to the success of the world's unique e\\pmp ring collider HERA. This article aims at providing a brief introduction to the physics motivation for deep-inelastic scattering of polarised electrons or positrons off protons, the basic mechanisms to establish lepton polarisation in the high-energy storage ring and to describe briefly the three different polarimeters, which measured both the transverse and the longitudinal polarisation.

  5. Obtaining the band structure of a complicated photonic crystal by linear operations

    Institute of Scientific and Technical Information of China (English)

    吴良; 叶卓; 何赛灵

    2003-01-01

    Absolute band gaps can be created by lifting the degeneracy in the bands of a photonic crystal.To calculate the band structure of a complicated photonic crystal generated by e.g.symmetry breaking,general forms of all possible linear operations are presented in terms of matrices and a procedure to combine these operations is given.Other forms of linear operations(such as the addition,subtraction,and translation transforms) are also presented to obtain an explicit expression for the Fourier coefficient of the dielectric function in the plane-wave expansion method.With the present method,band structures for various complicated photonic crystals(related through these linear operations) can be obtained easily and quickly.As a numerical example,a large absolute band gap for a complicated photonic crystal structure of GaAs is found in the high region of normalized frequency.

  6. Linear optics only allows every possible quantum operation for one photon or one port

    Science.gov (United States)

    Moyano-Fernández, Julio José; Garcia-Escartin, Juan Carlos

    2017-01-01

    We study the evolution of the quantum state of n photons in m different modes when they go through a lossless linear optical system. We show that there are quantum evolution operators U that cannot be built with linear optics alone unless the number of photons or the number of modes is equal to one. The evolution for single photons can be controlled with the known realization of any unitary proved by Reck, Zeilinger, Bernstein and Bertani. The evolution for a single mode corresponds to the trivial evolution in a phase shifter. We analyze these two cases and prove that any other combination of the number of photons and modes produces a Hilbert state too large for the linear optics system to give any desired evolution.

  7. Could the photon dispersion relation be non-linear ?

    OpenAIRE

    2008-01-01

    The free photon dispersion relation is a reference quantity for high precision tests of Lorentz Invariance. We first outline theoretical approaches to a conceivable Lorentz Invariance Violation (LIV). Next we address phenomenological tests based on the propagation of cosmic rays, in particular in Gamma Ray Bursts (GRBs). As a specific concept, which could imply LIV, we then focus on field theory in a non-commutative (NC) space, and we present non-perturbative results for the dispersion relati...

  8. Polarisation, key to good localisation.

    NARCIS (Netherlands)

    Beest, M. van; Robben, J.H.; Savelkoul, P.J.M.; Hendriks, G.; Devonald, M.A.; Konings, I.B.M.; Lagendijk, A.K.; Karet, F.; Deen, P.M.T.

    2006-01-01

    Polarisation of cells is crucial for vectorial transport of ions and solutes. In literature, however, proteins specifically targeted to the apical or basolateral membrane are often studied in non-polarised cells. To investigate whether these data can be extrapolated to expression in polarised cells,

  9. Plasma based helical undulator for controlled emission of circularly and elliptically polarised betatron radiationJ. Vieira, J. Martins, U. Sinha

    CERN Document Server

    Vieira, J; Sinha, U

    2016-01-01

    We explore a plasma based analogue of a helical undulator capable of providing circularly and elliptically polarised betatron radiation. We focus on ionisation injection configurations and in the conditions where the laser pulse driver can force collective betatron oscillations over the whole trapped electron bunch. With an analytical model and by employing three dimensional simulations and radiation calculations, we find that circularly or elliptically polarised laser drivers can force helical betatron oscillations, which produce circularly/elliptically polarised betatron x-rays. We assess the level of polarisation numerically and analytically, and find that the number of circularly polarised photons can be controlled by tuning the laser pulse driver polarisation. We show the production of betatron radiation that is circularly polarised up to < 40% close to regions of maximum photon flux. The total flux of circularly polarised betatron radiation drops for elliptically polarised drivers, and is negligible ...

  10. Linear and nonlinear modeling of light propagation in hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, John; Lægsgaard, Jesper

    2009-01-01

    Hollow core photonic crystal fibers (HC-PCFs) find applications which include quantum and non-linear optics, gas detection and short high-intensity laser pulse delivery. Central to most applications is an understanding of the linear and nonlinear optical properties. These require careful modeling...

  11. Deterministic implementations of single-photon multi-qubit Deutsch-Jozsa algorithms with linear optics

    Science.gov (United States)

    Wei, Hai-Rui; Liu, Ji-Zhen

    2017-02-01

    It is very important to seek an efficient and robust quantum algorithm demanding less quantum resources. We propose one-photon three-qubit original and refined Deutsch-Jozsa algorithms with polarization and two linear momentums degrees of freedom (DOFs). Our schemes are constructed by solely using linear optics. Compared to the traditional ones with one DOF, our schemes are more economic and robust because the necessary photons are reduced from three to one. Our linear-optic schemes are working in a determinate way, and they are feasible with current experimental technology.

  12. Deterministic implementations of single-photon multi-qubit Deutsch–Jozsa algorithms with linear optics

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Hai-Rui, E-mail: hrwei@ustb.edu.cn; Liu, Ji-Zhen

    2017-02-15

    It is very important to seek an efficient and robust quantum algorithm demanding less quantum resources. We propose one-photon three-qubit original and refined Deutsch–Jozsa algorithms with polarization and two linear momentums degrees of freedom (DOFs). Our schemes are constructed by solely using linear optics. Compared to the traditional ones with one DOF, our schemes are more economic and robust because the necessary photons are reduced from three to one. Our linear-optic schemes are working in a determinate way, and they are feasible with current experimental technology.

  13. Realization of non-linear coherent states by photonic lattices

    Directory of Open Access Journals (Sweden)

    Shahram Dehdashti

    2015-06-01

    Full Text Available In this paper, first, by introducing Holstein-Primakoff representation of α-deformed algebra, we achieve the associated non-linear coherent states, including su(2 and su(1, 1 coherent states. Second, by using waveguide lattices with specific coupling coefficients between neighbouring channels, we generate these non-linear coherent states. In the case of positive values of α, we indicate that the Hilbert size space is finite; therefore, we construct this coherent state with finite channels of waveguide lattices. Finally, we study the field distribution behaviours of these coherent states, by using Mandel Q parameter.

  14. Realization of non-linear coherent states by photonic lattices

    Energy Technology Data Exchange (ETDEWEB)

    Dehdashti, Shahram, E-mail: shdehdashti@zju.edu.cn; Li, Rujiang; Chen, Hongsheng, E-mail: hansomchen@zju.edu.cn [State Key Laboratory of Modern Optical Instrumentations, Zhejiang University, Hangzhou 310027 (China); The Electromagnetics Academy at Zhejiang University, Zhejiang University, Hangzhou 310027 (China); Liu, Jiarui, E-mail: jrliu@zju.edu.cn; Yu, Faxin [School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027 (China)

    2015-06-15

    In this paper, first, by introducing Holstein-Primakoff representation of α-deformed algebra, we achieve the associated non-linear coherent states, including su(2) and su(1, 1) coherent states. Second, by using waveguide lattices with specific coupling coefficients between neighbouring channels, we generate these non-linear coherent states. In the case of positive values of α, we indicate that the Hilbert size space is finite; therefore, we construct this coherent state with finite channels of waveguide lattices. Finally, we study the field distribution behaviours of these coherent states, by using Mandel Q parameter.

  15. Measurement of 1.7 to 74 MeV polarised gamma rays with the HARPO TPC

    CERN Document Server

    Geerebaert, Y; Amano, S; Attié, D; Bernard, D; Bruel, P; Calvet, D; Colas, P; Daté, S; Delbart, A; Frotin, M; Giebels, B; Götz, D; Hashimoto, S; Horan, D; Kotaka, T; Louzir, M; Minamiyama, Y; Miyamoto, S; Ohkuma, H; Poilleux, P; Semeniouk, I; Sizun, P; Takemoto, A; Yamaguchi, M; Wang, S

    2016-01-01

    Current {\\gamma}-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV-GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D program to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for {\\gamma} rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised {\\gamma}-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronic...

  16. Linear polarization of gluons and photons in unpolarized collider experiments

    NARCIS (Netherlands)

    Pisano, Cristian; Boer, Daniel; Brodsky, Stanley J.; Buffing, Maarten G. A.; Mulders, Piet J.

    2013-01-01

    We study azimuthal asymmetries in heavy quark pair production in unpolarized electron-proton and proton-proton collisions, where the asymmetries originate from the linear polarization of gluons inside unpolarized hadrons. We provide cross section expressions and study the maximal asymmetries allowed

  17. Complete description of polarization effects in the nonlinear Compton scattering. II. Linearly polarized laser photons

    CERN Document Server

    Ivanov, D Y; Serbo, V G

    2003-01-01

    We consider emission of a photon by an electron in the field of a strong laser wave. Polarization effects in this process are important for a number of physical problems. We discuss a probability of this process for linearly polarized laser photons and for arbitrary polarization of all other particles. We obtain the complete set of functions which describe such a probability in a compact form.

  18. Radiography with polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael L.

    2010-08-20

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni{sub 3}Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T{sub C} on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with

  19. Higgs boson pair production at the Photon Linear Collider in the two Higgs doublet model

    CERN Document Server

    Asakawa, Eri; Kanemura, Shinya; Okada, Yasuhiro; Tsumura, Koji

    2009-01-01

    We calculate the cross section of the lightest Higgs boson pair production at the Photon Linear Collider in the two Higgs doublet model. We focus on the scenario in which the lightest Higgs boson has the standard model like couplings to gauge bosons. We take into account the one-loop correction to the $hhh$ coupling as well as additional one-loop diagrams due to charged bosons to the $\\gamma\\gamma \\to hh$ helicity amplitudes. We discuss the impact of these corrections on the $hhh$ coupling measurement at the Photon Linear Collider.

  20. Does circular polarisation reveal the rotation of quasar engines?

    OpenAIRE

    Ensslin, Torsten A.

    2002-01-01

    Many radio sources like quasars, blazars, radio galaxies, and micro-quasars exhibit circular polarisation (CP) with surprising temporal persistent handedness. As a possible explanation we propose that the CP is due to Faraday conversion (FC) of linear polarisation (LP) synchrotron light which propagates along a line-of-sight (LOS) through twisted magnetic fields. The rotational nature of accretion flows onto black holes naturally generates the required magnetic twist in the emission region, i...

  1. Experiments on Linear and Nonlinear Localization of Optical Vortices in Optically Induced Photonic Lattices

    Directory of Open Access Journals (Sweden)

    Daohong Song

    2012-01-01

    Full Text Available We provide a brief overview on our recent experimental work on linear and nonlinear localization of singly charged vortices (SCVs and doubly charged vortices (DCVs in two-dimensional optically induced photonic lattices. In the nonlinear case, vortex propagation at the lattice surface as well as inside the uniform square-shaped photonic lattices is considered. It is shown that, apart from the fundamental (semi-infinite gap discrete vortex solitons demonstrated earlier, the SCVs can self-trap into stable gap vortex solitons under the normal four-site excitation with a self-defocusing nonlinearity, while the DCVs can be stable only under an eight-site excitation inside the photonic lattices. Moreover, the SCVs can also turn into stable surface vortex solitons under the four-site excitation at the surface of a semi-infinite photonics lattice with a self-focusing nonlinearity. In the linear case, bandgap guidance of both SCVs and DCVs in photonic lattices with a tunable negative defect is investigated. It is found that the SCVs can be guided at the negative defect as linear vortex defect modes, while the DCVs tend to turn into quadrupole-like defect modes provided that the defect strength is not too strong.

  2. Enhancing the Linear Dynamic Range in Multi-Channel Single Photon Detector beyond 7OD

    Science.gov (United States)

    Gudkov, Dmytro; Gudkov, George; Gorbovitski, Boris; Gorfinkel, Vera

    2015-01-01

    We present design, implementation, and characterization of a single photon detector based on 32-channel PMT sensor [model H7260-20, Hamamatsu]. The developed high speed electronics enables the photon counting with linear dynamic range (LDR) up to 108count/s per detector's channel. The experimental characterization and Monte-Carlo simulations showed that in the single photon counting mode the LDR of the PMT sensor is limited by (i) “photon” pulse width (current pulse) of 900ps and (ii) substantial decrease of amplitudes of current pulses for count rates exceeding 108 count/s. The multi-channel architecture of the detector and the developed firm/software allow further expansion of the dynamic range of the device by 32-fold by using appropriate beam shaping. The developed single photon counting detector was tested for the detection of fluorescence labeled microbeads in capillary flow. PMID:27087788

  3. Realisation and optical engineering of linear variable bandpass filters in nanoporous anodic alumina photonic crystals.

    Science.gov (United States)

    Sukarno; Law, Cheryl Suwen; Santos, Abel

    2017-06-08

    We present the first realisation of linear variable bandpass filters in nanoporous anodic alumina (NAA-LVBPFs) photonic crystal structures. NAA gradient-index filters (NAA-GIFs) are produced by sinusoidal pulse anodisation and used as photonic crystal platforms to generate NAA-LVBPFs. The anodisation period of NAA-GIFs is modified from 650 to 850 s to systematically tune the characteristic photonic stopband of these photonic crystals across the UV-visible-NIR spectrum. Then, the nanoporous structure of NAA-GIFs is gradually widened along the surface under controlled conditions by wet chemical etching using a dip coating approach aiming to create NAA-LVBPFs with finely engineered optical properties. We demonstrate that the characteristic photonic stopband and the iridescent interferometric colour displayed by these photonic crystals can be tuned with precision across the surface of NAA-LVBPFs by adjusting the fabrication and etching conditions. Here, we envisage for the first time the combination of the anodisation period and etching conditions as a cost-competitive, facile, and versatile nanofabrication approach that enables the generation of a broad range of unique LVBPFs covering the spectral regions. These photonic crystal structures open new opportunities for multiple applications, including adaptive optics, hyperspectral imaging, fluorescence diagnostics, spectroscopy, and sensing.

  4. Optical Isolation Can Occur in Linear and Passive Silicon Photonic Structures

    CERN Document Server

    Wang, Chen

    2012-01-01

    On-chip optical isolators play a key role in optical communications and computing based on silicon integrated photonic structures. Recently there have raised great attentions and hot controversies upon isolation of light via linear and passive photonic structures. Here we analyze the optical isolation properties of a silicon photonic crystal slab heterojunction diode by comparing the forward transmissivity and round-trip reflectivity of in-plane infrared light across the structure. The round-trip reflectivity is much smaller than the forward transmissivity, justifying good isolation. The considerable effective nonreciprocal transport of in-plane signal light in the linear and passive silicon optical diode is attributed to the information dissipation and selective modal conversion in the multiple-channel structure and has no conflict with reciprocal principle.

  5. Polarisation, key to good localisation.

    NARCIS (Netherlands)

    Beest, M. van; Robben, J.H.; Savelkoul, P.J.M.; Hendriks, G.; Lagendijk, A.K.; Karet, F.; Deen, P.M.T.

    2006-01-01

    Polarisation of cells is crucial for vectorial transport of ions and solutes. In literature, however, proteins specifically targeted to the apical or basolateral membrane are often studied in non-polarised cells. To investigate whether these data can be extrapolated to expression in

  6. Experimental investigations of the neutron contamination in high-energy photon fields at medical linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunckhorst, Elin

    2009-02-26

    The scope of this thesis was to develop a device for the detection of the photoneutron dose inside the high-energy photon field. The photoneutron contamination of a Siemens PRIMUS linear accelerator was investigated in detail in its 15 MV photon mode. The experimental examinations were performed with three ionisation chambers (a tissue equivalent chamber, a magnesium chamber and a {sup 10}B-coated magnesium chamber) and two types of thermoluminescence detectors (enriched with {sup 6}Li and {sup 7}Li, respectively). The detectors have different sensitivities to photons and neutrons and their combination allows the dose separation in a mixed neutron/photon field. The application of the ionisation chamber system, as well as the present TLD system for photoneutron detection in high-energy photon beams is a new approach. The TLD neutron sensitivity was found to be too low for a measurement inside the open photon field and the further investigation focused on the ionisation chambers. The three ionisation chambers were calibrated at different photon and neutron sources and a the borated magnesium chamber showed a very high response to thermal neutrons. For a cross check of the calibration, the three chambers were also used for dose separation of a boron neutron capture therapy beam where the exact determination of the thermal neutron dose is essential. Very accurate results were achieved for the thermal neutron dose component. At the linear accelerator the chamber system was reduced to a paired chamber system utilising the two magnesium chambers, since the fast neutron component was to small to be separated. The neutron calibration of the three chambers could not be applied, instead a conversion of measured thermal neutron signal by the borated chamber to Monte Carlo simulated total neutron dose was performed. Measurements for open fields in solid water and liquid water were performed with the paired chamber system. In larger depths the neutron dose could be determined

  7. Tunable Microwave Photonic Notch Filter Based on a high-birefringence linearly chirped fiber Bragg grating

    Energy Technology Data Exchange (ETDEWEB)

    Jin Yongxing; Dong Xinyong; Wang Jianfeng [Institute of Optoelectronic Technology, China Jiliang University, Hangzhou (China); Zhou Junqiang, E-mail: phyjyxin@gmail.com [Network Technology Research Centre, Nanyang Technological University (Singapore)

    2011-02-01

    In this paper, a continuously tunable microwave photonic notch filter is proposed and experimentally demonstrated. This filter is based on the differential group delay generated by a high-birefringence linearly chirped fiber Bragg grating. This microwave photonic filter belongs to the orthogonal polarization approach, polarization maintaining structure ensures the filter free from the random optical interference problem. Its response is induced by the differential group delay (DGD) of the Hi-Bi LCFBG and it can be varied by tuning the grating through adding gradient strength to the grating. Free spectral range tuning by 9.27 GHz with more than 35 dB notch rejection is achieved.

  8. Hadron Contribution to Vacuum Polarisation

    Science.gov (United States)

    Davier, M.; Hoecker, A.; Malaescu, B.; Zhang, Z.

    2016-10-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle-antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e- annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingredients to high precision tests of the Standard Theory.

  9. Hadron Contribution to Vacuum Polarisation

    CERN Document Server

    Davier, M; Malaescu, B; Zhang, Z

    2016-01-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...

  10. Modelling elliptically polarised Free Electron Lasers

    CERN Document Server

    Henderson, J R; Freund, H P; McNeil, B W J

    2016-01-01

    A model of a Free Electron Laser operating with an elliptically polarised undulator is presented. The equations describing the FEL interaction, including resonant harmonic radiation fields, are averaged over an undulator period and generate a generalised Bessel function scaling factor, similar to that of planar undulator FEL theory. Comparison between simulations of the averaged model with those of an unaveraged model show very good agreement in the linear regime. Two unexpected results were found. Firstly, an increased coupling to harmonics for elliptical rather than planar polarisarised undulators. Secondly, and thought to be unrelated to the undulator polarisation, a signficantly different evolution between the averaged and unaveraged simulations of the harmonic radiation evolution approaching FEL saturation.

  11. Anisotropy and linear polarization of radiative processes in energetic ion-atom collisions; Untersuchung zur Anisotropie und linearen Polarisation radiativer Prozesse in energiereichen Ion-Atom-Stoessen

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Guenter

    2010-06-16

    In the present thesis the linear polarization of radiation emitted in energetic ion-atom collisions at the ESR storage ring was measured by applying a novel type of position, timing and energy sensitive X-ray detector as a Compton polarimeter. In contrast to previous measurements, that mainly concentrate on studies of the spectral and angular distribution, the new detectors allowed the first polarization study of the Ly-{alpha}{sub 1} radiation (2p{sub 3/2}{yields}1s{sub 1/2}) in U{sup 91+}. Owing to the high precision of the polarimeters applied here, the experimental results indicate a significant depolarization of the Ly-{alpha}{sub 1} radiation caused by the interference of the E1 and M2 transition branches. Moreover, the current investigation shows that measurements of the linear polarization in combination with angular distribution studies provide a model-independent probe for the ratio of the E1 and M2 transition amplitudes and, consequently, of the corresponding transition probabilities. In addition, a first measurement of the linear polarization as well as an angular distribution study of the electron-nucleus Bremsstrahlung arising from ion-atom collisions was performed. The experimental results obtained were compared to exact relativistic calculations and, in case of the Bremsstrahlung, to a semirelativistic treatment. In general, good agreement was found between theoretical predictions and experimental findings. (orig.)

  12. Ultimate parameters of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    V I Telnov

    2007-12-01

    At linear colliders, the + - luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). In collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping ring designs, nominal DR parameters correspond to those required for + - collisions. In this note, I would like to stress once again that as soon as we plan the photon collider mode of ILC operation, the damping ring emittances are dictated by the photon collider requirements - namely, they should be as small as possible. This can be achieved by adding more wigglers to the DRs; the incremental cost is easily justified by a considerable potential improvement of the luminosity. No expert analysis exists as of now, but it seems realistic to obtain a factor five increase of the luminosity compared to the `nominal' DR design.

  13. Linear Mode HgCdTe Avalanche Photodiodes for Photon Counting Applications

    Science.gov (United States)

    Sullivan, William, III; Beck, Jeffrey; Scritchfield, Richard; Skokan, Mark; Mitra, Pradip; Sun, Xiaoli; Abshire, James; Carpenter, Darren; Lane, Barry

    2015-01-01

    An overview of recent improvements in the understanding and maturity of linear mode photon counting with HgCdTe electron-initiated avalanche photodiodes is presented. The first HgCdTe LMPC 2x8 format array fabricated in 2011 with 64 micron pitch was a remarkable success in terms of demonstrating a high single photon signal to noise ratio of 13.7 with an excess noise factor of 1.3-1.4, a 7 ns minimum time between events, and a broad spectral response extending from 0.4 micron to 4.2 micron. The main limitations were a greater than 10x higher false event rate than expected of greater than 1 MHz, a 5-7x lower than expected APD gain, and a photon detection efficiency of only 50% when greater than 60% was expected. This paper discusses the reasons behind these limitations and the implementation of their mitigations with new results.

  14. Meson photproduction from a transversely polarised target at MAMI

    CERN Document Server

    Barrientos, P Hall

    2011-01-01

    A new transversely polarised frozen spin target has been developed at MAMI which will be used in conjunction with the photon tagger and the Crystal Ball detector. The new target permits a major new programme of accurate measurement of polarisation observables in meson photoproduction. This contribution presents some of the preliminary analysis from experimental data taken near the threshold and in the region of the $\\Delta(1232)$ resonance. Observables will be obtained for the $p\\pi^0$ and $n\\pi^+$ final states.

  15. φ-meson Photoproduction By Using a Beam of Linearly-Polarized Photons

    Science.gov (United States)

    Salamanca, Julian; Cole, Philip

    2007-05-01

    The observables afforded by linearly-polarized photons provide the necessary means towards delineating the contributions of the various hadronic processes, which give rise to vector meson photoproduction. And in particular, We shall describe how φ meson production affords an incisive tool for exploring the nature of the parity exchange at threshold energies, the strangeness content of proton, as well as extracting signatures for the violation of Okubo-Zweig-Iizuka observation (OZI rule). Our goal will be measure the γ p ->φp reaction, with φ->K^+K^-, in the photon energy range of 1.7G to 2.1 GeV by using the Coherent Linear Bremsstrahlung Facility in Hall B of Jefferson Laboratory (Newport News, VA). The data were collected during the g8b run in the summer of 2005. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NWS07.B2.5

  16. Efficient generation of linearly polarized Cerenkov radiation in a photonic crystal fiber with suspended rectangle core

    Science.gov (United States)

    Luo, Xing; Cheng, Lan; Peng, Jinggang; Yang, Luyun; Dai, Nengli; Li, Haiqing; Li, Jinyan

    2017-10-01

    We report high efficiency linearly polarized Cerenkov radiation (CR) generation in a photonic crystal fiber with suspended rectangle core. The frequency up-conversion via the Cerenkov radiation upon pumping of Yb-doped femtosecond fiber laser is discussed in details. Experiment results show that the output spectrum contains, besides the infrared supercontinuum, intense green Cerenkov radiation around 536 nm, which carry about 43% of the pump energy at best. The influence of the high birefringence and dispersion character on the Cerenkov radiation generation is discussed. Experiment and simulation results indicate that the rectangle core photonic crystal fiber acts like single-mode single-polarization fiber at the pump wavelength. Only the pulse component along with the slow axis could be confined in the rectangle core well and release Cerenkov radiation efficiently. The Output green Cerenkov radiation is also demonstrated to be linearly polarized. Experiments results agree well with the theoretical predictions.

  17. Associated single photons and doubly-charged scalars at linear - - colliders

    Indian Academy of Sciences (India)

    Biswarup Mukhopadhyaya; Santosh Kumar Rai

    2007-11-01

    Doubly-charged scalars, predicted in many models having exotic Higgs representations, can in general have lepton-number violating (LFV) couplings. We show that by using an associated monoenergetic final state photon seen at a future linear - - collider, we can have a clear and distinct signature for a doubly-charged resonance. The strength of the = 2 coupling can also be probed quite effectively as a function of the recoil mass of the doubly-charged scalar.

  18. Physics case for a polarised target for AFTER@LHC

    CERN Document Server

    Lansberg, J P; Arnaldi, R; Brodsky, S J; Chambert, V; Didelez, J P; Echevarria, M G; Ferreiro, E G; Fleuret, F; Gao, Y; Genolini, B; Hadjidakis, C; Hrivnacova, I; Kikola, D; Kurepin, A; Lorce, C; Massacrier, L; Nass, A; Pisano, C; Schienbein, I; Schlegel, M; Scomparin, E; Seixas, J; Signori, A; Steffens, E; Topilskaya, N; Uggerhoej, B Trzeciak U I; Uras, A; Ulrich, R; Yang, Z

    2016-01-01

    We review a number of ideas put forward in favour of the use of a polarised target along with the proposed idea of a fixed-target experiment using the LHC beams -- AFTER@LHC. A number of recent studies have shown that single transverse-spin asymmetries (STSAs) are large enough to be precisely measured in the region accessible with AFTER@LHC, in particular as regards the Drell-Yan process as well as single-pion, isolated-photon and jet production. AFTER@LHC with a polarised target would also be the ideal experimental set-up to measure the gluon Sivers effect via a number of original quarkonium STSA studies. We discuss first figures-of-merit based on simulations for AFTER@LHC with a polarised target.

  19. A single-source photon source model of a linear accelerator for Monte Carlo dose calculation.

    Science.gov (United States)

    Nwankwo, Obioma; Glatting, Gerhard; Wenz, Frederik; Fleckenstein, Jens

    2017-01-01

    To introduce a new method of deriving a virtual source model (VSM) of a linear accelerator photon beam from a phase space file (PSF) for Monte Carlo (MC) dose calculation. A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden) and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs) for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC) between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses. The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate) for the evaluated fields. A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.

  20. Polarisation Encryption/Decryption Module

    DEFF Research Database (Denmark)

    2002-01-01

    A polarisation encryption/decryption module comprising at least two array based modulating devices, preferably spatial light modulators (SLMs), at least one array based intensity detector, and at least one source of electromagnetic radiation. A local region of information displayed on a first of ...... rapidly. May be used for real time encryption/decryption of motion pictures. Further, a method of polarisation encrypting and decrypting information. The encryption/decryption is performed optically while the communication is performed electronically....

  1. Polarised neutron scattering from dynamic polarised targets in biology

    Science.gov (United States)

    Knop, W.; Hirai, M.; Olah, G.; Meerwinck, W.; Schink, H.-J.; Stuhrman, H. B.; Wagner, R.; Wenkow-EsSouni, M.; Zhao, J.; Schärpf, O.; Crichton, R. R.; Krumpolc, M.; Nierhaus, K. H.; Niinikoski, T. O.; Rijllart, A.

    1991-10-01

    The contrast giving rise to neutron small-angle scattering can be enhanced considerably by polarisation of the hydrogen nuclei [J. des Coizeaux and G. Jannink, Les Polymères en Solution, Les Editions de Physique, F-91944 Les Ulis, France (1987)]. Using polarised neutrons the scattering from protonated labels in a deuterated matrix will increase by an order of magnitude. This is the basis of nuclear spin contrast variation, a method which is of particular interest for the in situ structure determination of macromolecular components. A new polarised target for neutron scattering has been designed by CERN and tested successfully at FRG-1 of the GKSS research centre. For the purpose of thermal-neutron scattering the frozen solutions of biomolecules are immersed in liquid helium 4, which is thermally coupled to the cooling mixture of helium 3/helium 4 of the dilution refrigerator. The nuclear spins are aligned with respect to the external magnetic field-parallel or antiparallel-by dynamic nuclear polarisation (DNP). The gain in neutron scattering compared to earlier experiments using direct cooling of the sample by helium 3 is a factor of 30. Another factor of 30 arises from the installation of the cold source and the beryllium reflector in FRG-1 [W. Knop et al., J. Appl. Cryst. 22 (1989) 352]. Pure nuclear spin targets are produced from dynamic polarised targets by selective depolarisation. In biological material only the hydrogen isotopes contribute significantly to polarised neutron scattering. Thus, saturation of the proton NMR yields a deuteron target, provided the target material has been enriched by the latter isotope. A proton target is obtained from the dynamic polarised target by saturation of deuteron NMR. This leads to six additional scattering functions reflecting the proton and deuteron spin densities and the correlations between the polarised isotopes. Polarised neutron scattering from nuclear spin targets of apoferritin and various derivatives of the

  2. Mcps-range photon-counting X-ray computed tomography system utilizing an oscillating linear-YAP(Ce) photon detector

    Science.gov (United States)

    Oda, Yasuyuki; Sato, Eiichi; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Osawa, Akihiro; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sugimura, Shigeaki; Endo, Haruyuki; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2011-07-01

    High-speed X-ray photon counting is useful for discriminating photon energy, and the counting can be used for constructing an X-ray computed tomography (CT) system. A photon-counting X-ray CT system consists of an X-ray generator, a turntable, an oscillation linear detector, a two-stage controller, a multipixel photon counter (MPPC) module, a 1.0 mm-thick crystal (scintillator) of YAP(Ce) (cerium-doped yttrium aluminum perovskite), a counter card (CC), and a personal computer (PC). Tomography is accomplished by repeating the linear scanning and the rotation of an object, and projection curves of the object are obtained by the linear scanning using the detector consisting of an MPPC module, the YAP(Ce), and a scan stage. The pulses of the event signal from the module are counted by the CC in conjunction with the PC. Because the lower level of the photon energy was roughly determined by a comparator in the module, the average photon energy of the X-ray spectra increased with increase in the lower-level voltage of the comparator at a constant tube voltage. The maximum count rate was approximately 3 Mcps (mega counts per second), and photon-counting CT was carried out.

  3. A Simple Method on Generating any Bi-Photon Superposition State with Linear Optics

    Science.gov (United States)

    Zhang, Ting-Ting; Wei, Jie; Wang, Qin

    2017-04-01

    We present a simple method on the generation of any bi-photon superposition state using only linear optics. In this scheme, the input states, a two-mode squeezed state and a bi-photon state, meet on a beam-splitter and the output states are post-selected with two threshold single-photon detectors. We carry out corresponding numerical simulations by accounting for practical experimental conditions, calculating both the Wigner function and the state fidelity of those generated bi-photon superposition states. Our simulation results demonstrate that not only distinct nonclassical characteristics but also very high state fidelities can be achieved even under imperfect experimental conditions. Supported by the National Natural Science Foundation of China under Grant Nos. 61475197, 61590932, 11274178, the Natural Science Foundation of the Jiangsu Higher Education Institutions under Grant No. 15KJA120002, the Outstanding Youth Project of Jiangsu Province under Grant No. BK20150039, and the Priority Academic Program Development of Jiangsu Higher Education Institutions under Grant No. YX002001

  4. Dosimetric aspects of the therapeutic photon beams from a dual-energy linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghazi, M.S.A.L.; Arjune, B.; Fiedler, J.A.; Sharma, P.D.

    1988-03-01

    Parameters of the photon beams (6 and 20 MV) from a dual-energy linear accelerator (Mevatron-KD, Siemens Medical Laboratories, CA) are presented. The depth dose characteristics of the photon beams are d/sub max/ of 1.8 and 3.8 cm and percentage depth dose of 68% and 80% at 10-cm depth and 100-cm source--surface distance for a field size of 10 x 10 cm/sup 2/ for 6 and 20 MV, respectively. The 6 and 20 MV beams were found to correspond to nominal accelerating potentials of 4.7 and 17 MV, respectively. The stability of output is within +- 1% and flatness and symmetry are within +- 3%. These figures compare favorably with the manufacturer's specifications.

  5. Linearly polarized single photon antibunching from a site-controlled InGaN quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Jemsson, Tomas; Machhadani, Houssaine; Karlsson, K. Fredrik; Hsu, Chih-Wei; Holtz, Per-Olof [Department of Physics, Chemistry, and Biology (IFM), Semiconductor Materials, Linköping University, S-58183 Linköping (Sweden)

    2014-08-25

    We report on the observation of linearly polarized single photon antibunching in the excitonic emission from a site-controlled InGaN quantum dot. The measured second order coherence function exhibits a significant dip at zero time difference, corresponding to g{sub m}{sup 2}(0)=0.90 under continuous laser excitation. This relatively high value of g{sub m}{sup 2}(0) is well understood by a model as the combination of short exciton life time (320 ps), limited experimental timing resolution and the presence of an uncorrelated broadband background emission from the sample. Our result provides the first rigorous evidence of InGaN quantum dot formation on hexagonal GaN pyramids, and it highlights a great potential in these dots as fast polarized single photon emitters if the background emission can be eliminated.

  6. A Miniaturized Linear Wire Ion Trap with Electron Ionization and Single Photon Ionization Sources

    Science.gov (United States)

    Wu, Qinghao; Tian, Yuan; Li, Ailin; Andrews, Derek; Hawkins, Aaron R.; Austin, Daniel E.

    2017-05-01

    A linear wire ion trap (LWIT) with both electron ionization (EI) and single photon ionization (SPI) sources was built. The SPI was provided by a vacuum ultraviolet (VUV) lamp with the ability to softly ionize organic compounds. The VUV lamp was driven by a pulse amplifier, which was controlled by a pulse generator, to avoid the detection of photons during ion detection. Sample gas was introduced through a leak valve, and the pressure in the system is shown to affect the signal-to-noise ratio and resolving power. Under optimized conditions, the limit of detection (LOD) for benzene was 80 ppbv using SPI, better than the LOD using EI (137 ppbv). System performance was demonstrated by distinguishing compounds in different classes from gasoline.

  7. Photonic generation of linearly chirped millimeter wave based on comb-spacing tunable optical frequency comb

    Science.gov (United States)

    Xia, Zongyang; Xie, Weilin; Sun, Dongning; Shi, Hongxiao; Dong, Yi; Hu, Weisheng

    2013-12-01

    We demonstrated a photonic approach to generate a phase-continuous frequency-linear-chirped millimeter-wave (mm-wave) signal with high linearity based on continuous-wave phase modulated optical frequency comb and cascaded interleavers. Through linearly sweeping the frequency of the radio frequency (RF) driving signal, high-order frequency-linear-chirped optical comb lines are generated and then extracted by the cascaded interleavers. By beating the filtered high-order comb lines, center frequency and chirp range multiplied linear-chirp microwave signals are generated. Frequency doubled and quadrupled linear-chirp mm-wave signals of range 48.6 to 52.6 GHz and 97.2 to 105.2 GHz at chirp rates of 133.33 and 266.67 GHz/s are demonstrated with the ±1st and ±2nd optical comb lines, respectively, while the RF driving signal is of chirp range 24.3 to 26.3 GHz and chirp time 30 ms.

  8. PHOTON09. Proceedings of the international conference on the structure and interactions of the photon including the 18th international workshop on photon-photon collisions and the international workshop on high energy photon linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Olaf; Diehl, Markus; Schoerner-Sadenius, Thomas; Steinbrueck, Georg (eds.)

    2010-01-15

    The following topics were dealt with: Electroweak and new physics, photon-collider technology, low-energy photon experiments, prompt photons, photon structure, jets and heavy flavours, vacuum polarization and light-by-light scattering, small-x processes, diffraction, total cross sections, exclusive channels and resonances, photons in astroparticle physics. (HSI)

  9. Spin Polarisabilities and Compton Scattering from χEFT: Bridging QCD and Data

    Science.gov (United States)

    Griesshammer, Harald W.; McGovern, Judith A.; Phillips, Daniel R.

    2017-01-01

    Compton scattering from protons and neutrons probes their two-photon response in electric and magnetic fields of real photons, exploring the symmetries and interaction strengths of the internal degrees of freedom. With the scalar polarisabilities αE 1 and βM 1 now reasonably understood, the focus turns to the so-far poorly explored spin-polarisabilities. They parametrise the stiffness of the nucleon spin in external electro-magnetic fields, analogous to rotations of the polarisation of light by optically active media (bi-refringence/Faraday effect) and are particularly sensitive to the directional dependence of the πNγ interactions dictated by chiral symmetry and its breaking. This contribution addresses the potential of Chiral Effective Field Theory to relate between lattice QCD and ongoing or approved efforts at MAX-lab, HI γS and MAMI. We discuss high-intensity experiments with polarised targets and polarised beams which will allow the extraction of the spin-polarisabilities; χEFT predictions which indicate which observables for polarised protons, deuterons and 3 He are particularly sensitive; convergence, residual theoretical uncertainties and possibilities for improvement; and chiral extrapolations in mπ for lattice computations. Supported in part by UK STFC, US DOE and George Washington University.

  10. Simple Linear Optical 'Binary Measurement Tree' for Single Photonic Polarization Qubit

    Institute of Scientific and Technical Information of China (English)

    HAN Yang; WU Wei; WU Chun-Wang; CHEN Ping-Xing; LI Cheng-Zu

    2009-01-01

    Positive-operator-value-measurement (POVM) is one of the essential components of quantum information process-ing (QIP). Recently a 'binary measurement tree' (BST) strategy (PRA 77, 052104) is suggested for implementing arbitrary POVM by sequential two-operator POVMs. We present a simple novel two-operator POVM module via linear optics, which is employed as block to construct a 'binary measurement tree' for implementing arbitrary POVM on single photonic polarization qubit. The total complexity of the experimental setup is significantly reduced in contrast to the previous works. As an example, we give the detailed settings of a well-known POVM.

  11. Linearly polarized intracavity passive Q-switched Yb-doped photonic crystal fibre laser

    Indian Academy of Sciences (India)

    Usha Chakravarty; Antony Kuruvilla; Rajpal Singh; B N Upadhyay; K S Bindra; S M Oak

    2014-02-01

    In this paper we report linearly polarized high average power passive Q-switched ytterbium-doped photonic crystal fibre laser with a Cr4+:YAG crystal as a saturable absorber. An average output power of 9.4 W with pulse duration of 64 ns and pulse repetition rate of 57.4 kHz with a slope efficiency of 52% was achieved. Measured polarization extinction ratio (PER) of the Q-switched laser output was 10.5 dB.

  12. Heavy neutral MSSM Higgs bosons at the photon linear collider - a comparison of two analyses

    Indian Academy of Sciences (India)

    M Spira; P Nieżurawski; M Krawczyk; A F Żarnecki

    2007-11-01

    Measurement of the heavy neutral MSSM Higgs bosons and production in the process → / → $b\\bar{b}$ at the Photon Linear Collider [1,2] has been considered in two independent analyses for the parameter range corresponding to the so-called `LHC wedge'. Significantly different conclusions were obtained; signal-to-background ratio 36 vs. 2. Here assumptions and results of these two analyses are compared. We have found that differences in the final results are mainly due to different assumptions on -luminosity spectra, jet definitions and selection cuts.

  13. Two-photon phase gate with linear optical elements and atom-cavity system

    Science.gov (United States)

    Kang, Yi-Hao; Xia, Yan; Lu, Pei-Min

    2016-09-01

    We propose a protocol for implementing π phase gate of two photons with linear optical elements and an atom-cavity system. The evolution of the atom-cavity system is based on the quantum Zeno dynamics. The devices in the present protocol are simple and feasible with current experimental technology. Moreover, the method we proposed here is deterministic with a high fidelity. Numerical simulation shows that the evolution in cavity is efficient and robust. Therefore, the protocol may be helpful for quantum computation field.

  14. Direct Measurement of the Gluon Polarisation in the Nucleon via Charmed Meson Production

    CERN Document Server

    Alekseev, M; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Arbuzov, A; Badelek, Barbara Maria; Balestra, F; Ball, J; Barth, J; Baum, Guenter; Bedfer, Y; Bernet, Colin; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, Franco; Brona, G; Burtin, E; Bussa, M P; Chapiro, A; Chiosso, M; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Dafni, T; Das, S; Dasgupta, S S; De Masi, R; Dedek, N; Dhara, L; Diaz, V; Dinkelbach, A M; Donskov, S V; Dorofeev, V A; Doshita, N; Duic, V; Dunnweber, W; Eversheim, P D; Eyrich, W; Faessler, M; Falaleev, V; Ferrero, L; Finger, M; Finger, M., Jr; Fischer, H; Franco, C; Franz, J; Friedrich, J M; Garfagnini, R; Gautheron, Fabrice; Gavrichtchouk, O P; Gazda, R; Geyer, R; Giorgi, M; Gobbo, Benigno; Gorin, A M; Grabmuller, S; Grajek, O A; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; Hannappel, J; von Harrach, D; Hasegawa, T; Heckmann, J; Hedicke, S; Heinsius, Fritz-Herbert; Hermann, R; Hess, C; Hinterberger, F; von Hodenberg, M; Horikawa, S; d'Hose, N; Ilgner, C; Ioukaev, A I; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Jahn, R; Janata, A; Jasinski, P; Joosten, R; Jouravlev, N I; Kabuss, E; Kang, D; Ketzer, Bernhard; Khaustov, G V; Khokhlov, Yu A; Klein, F; Klimaszewski, K; Koblitz, S; Kolosov, V N; Komissarov, E V; Kondo, K; Konigsmann, Kay; Konstantinov, V F; Korentchenko, A S; Koutchinski, N A; Kral, A; Kravchuk, N P; Kroumchtein, Z V; Kuhn, R; Kunne, Fabienne; Kurek, Krzysztof; Ladygin, M E; Le Goff, Jean-Marc; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Ludwig, I; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Marroncle, J; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Meyer, W.Thomas; Mikhailov, Yu V; Moinester, M A; Nagaytsev, A; Nagel, T; Nahle, O; Nassalski, J; Neliba, S; Nerling, F; Neubert, S; Neyret, D P; Nikolaenko, V I; Nikolaev, K; Olshevsky, A G; Ostrick, M; Padee, A; Pagano, P; Panebianco, S; Panknin, R; Panzieri, D; Paul, S; Pawlukiewicz-Kaminska, B; Peshekhonov, D V; Peshekhonov, V D; Piragino, G; Platchkov, Stephane; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Procureur, S; Quintans, C; Rajotte, J F; Ramos, S.; Rapatsky, V; Reicherz, G; Reggiani, D; Richter, A; Robinet, F; Rondio, Ewa; Rozhdestvensky, A M; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S; Savin, Igor A; Schiavon, P; Schill, Christian; Schonmeier, P; Schroder, W; Shevchenko, O Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stinzing, F; Sugonyaev, V P; Sulc, M; Sulej, R; Tchalishev, V V; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Venugopal, G; Virius, M; Vlassov, N V; Vossen, A; Webb, Robert C; Weitzel, Q; Windmolders, R; Wirth, S; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziegler, R; Zvyagin, A

    2008-01-01

    We present the first measurement of the gluon polarisation in the nucleon based on the photon-gluon fusion process tagged by charmed meson production and decay to charged K and pi. The data were collected in polarised muon scattering off a polarised deuteron target by the COMPASS collaboration at CERN during 2002-2004. The result of this LO analysis is _x = -0.47 +- 0.44 (stat) +- 0.15 (syst) at ~= 0.11 and a scale mu^2 ~ 13 (GeV/c)^2.

  15. Threshold π0 photoproduction on transverse polarised protons at MAMI

    Directory of Open Access Journals (Sweden)

    S. Schumann

    2015-11-01

    Full Text Available Polarisation-dependent differential cross sections σT associated with the target asymmetry T have been measured for the reaction γp→→pπ0 with transverse target polarisation from π0 threshold to photon energies of 190 MeV. The data were obtained using a frozen-spin butanol target with the Crystal Ball / TAPS detector set-up and the Glasgow photon tagging system at the Mainz Microtron MAMI. Results for σT have been used in combination with our previous measurements of the unpolarised cross section σ0 and the beam asymmetry Σ for a model-independent determination of S- and P-wave multipoles in the π0 threshold region, which includes for the first time a direct determination of the imaginary part of the E0+ multipole.

  16. Deeply virtual Compton scattering off longitudinally polarised protons at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, David Francis

    2010-06-15

    This thesis details the simultaneous extraction of three polarisation-dependent asymmetries in the distribution of real photons from the ep{yields}ep{gamma} interaction and its indistinguishable deeply virtual Compton scattering and Bethe-Heitler processes at the HERMES fixed-target experiment at Desy. The data analysed were taken using a longitudinally polarised 27.57 GeV positron beam incident on a longitudinally polarised hydrogen gas target. The extracted asymmetries include two single-spin asymmetries A{sub UL} and A{sub LU} which depend on the polarisation of the target and beam respectively, averaged over all other polarisation states. The double-spin asymmetry A{sub LL} dependent on the product of the beam and target polarisations is extracted for the first time. The asymmetry amplitudes extracted relate to combinations of Generalised Parton Distributions (GPDs), predominantly H and H. The extracted amplitudes are presented across the HERMES kinematic range alongside theoretical predictions from a GPD model based on double distributions. Large sin {phi} and cos(0{phi}) amplitudes are observed for A{sub UL} and A{sub LL} respectively, with an unexpectedly large sin(2{phi}) amplitude for A{sub UL}. The results for the A{sub UL} and A{sub LL} asymmetries are broadly compatible with theory predictions, and the extracted A{sub LU} amplitudes are compatible with HERMES results extracted from a significantly larger data set. It is foreseen that these results will form input to future global data-based GPD models which aim to provide a better understanding of GPDs. (orig.)

  17. Measurement of Coherent Emission and Linear Polarization of Photons by Electrons in the Strong Fields of Aligned Crystals

    CERN Document Server

    Apyan, A; Badelek, B; Ballestrero, S; Biino, C; Birol, I; Cenci, P; Connell, S H; Eichblatt, S; Fonseca, T; Freund, A; Gorini, B; Groess, R; Ispirian, K; Ketel, T; Kononets, Yu V; López, A; Mangiarotti, A; Van Rens, B; Sellschop, J P Friedel; Shieh, M; Sona, P; Strakhovenko, V M; Uggerhøj, Erik; Uggerhøj, U; Ünel, G; Velasco, M; Vilakazi, Z Z; Wessely, O; Kononets, Yu.V.

    2004-01-01

    We present new results regarding the features of high energy photon emission by an electron beam of 178 GeV penetrating a 1.5 cm thick single Si crystal aligned at the Strings-Of-Strings (SOS) orientation. This concerns a special case of coherent bremsstrahlung where the electron interacts with the strong fields of successive atomic strings in a plane and for which the largest enhancement of the highest energy photons is expected. The polarization of the resulting photon beam was measured by the asymmetry of electron-positron pair production in an aligned diamond crystal analyzer. By the selection of a single pair the energy and the polarization of individual photons could be measured in an the environment of multiple photons produced in the radiator crystal. Photons in the high energy region show less than 20% linear polarization at the 90% confidence level.

  18. Polarisation control of DFB fibre lasers

    DEFF Research Database (Denmark)

    Varming, Poul; Philipsen, Jacob Lundgreen; Berendt, Martin Ole

    1998-01-01

    The polarisation properties of a distributed feedback (DFB) fibre laser are investigated. It is shown experimentally that the birefringence of the UV induced phase-shift is the dominating effect controlling the polarisation properties of the laser......The polarisation properties of a distributed feedback (DFB) fibre laser are investigated. It is shown experimentally that the birefringence of the UV induced phase-shift is the dominating effect controlling the polarisation properties of the laser...

  19. Silicon Photonics: All-Optical Devices for Linear and Nonlinear Applications

    Science.gov (United States)

    Driscoll, Jeffrey B.

    Silicon photonics has grown rapidly since the first Si electro-optic switch was demonstrated in 1987, and the field has never grown more quickly than it has over the past decade, fueled by milestone achievements in semiconductor processing technologies for low loss waveguides, high-speed Si modulators, Si lasers, Si detectors, and an enormous toolbox of passive and active integrated devices. Silicon photonics is now on the verge of major commercialization breakthroughs, and optical communication links remain the force driving integrated and Si photonics towards the first commercial telecom and datacom transceivers; however other potential and future applications are becoming uncovered and refined as researchers reveal the benefits of manipulating photons on the nanoscale. This thesis documents an exploration into the unique guided-wave and nonlinear properties of deeply-scaled high-index-contrast sub-wavelength Si waveguides. It is found that the tight confinement inherent to single-mode channel waveguides on the silicon-on-insulator platform lead to a rich physics, which can be leveraged for new devices extending well beyond simple passive interconnects and electro-optic devices. The following chapters will concentrate, in detail, on a number of unique physical features of Si waveguides and extend these attributes towards new and interesting devices. Linear optical properties and nonlinear optical properties are investigated, both of which are strongly affected by tight optical confinement of the guided waveguide modes. As will be shown, tight optical confinement directly results in strongly vectoral modal components, where the electric and magnetic fields of the guided modes extend into all spatial dimensions, even along the axis of propagation. In fact, the longitudinal electric and magnetic field components can be just as strong as the transverse fields, directly affecting the modal group velocity and energy transport properties since the longitudinal fields

  20. Direct generation of linearly polarized single photons with a deterministic axis in quantum dots

    Science.gov (United States)

    Wang, Tong; Puchtler, Tim J.; Patra, Saroj K.; Zhu, Tongtong; Ali, Muhammad; Badcock, Tom J.; Ding, Tao; Oliver, Rachel A.; Schulz, Stefan; Taylor, Robert A.

    2017-08-01

    We report the direct generation of linearly polarized single photons with a deterministic polarization axis in self-assembled quantum dots (QDs), achieved by the use of non-polar InGaN without complex device geometry engineering. Here, we present a comprehensive investigation of the polarization properties of these QDs and their origin with statistically significant experimental data and rigorous k·p modeling. The experimental study of 180 individual QDs allows us to compute an average polarization degree of 0.90, with a standard deviation of only 0.08. When coupled with theoretical insights, we show that these QDs are highly insensitive to size differences, shape anisotropies, and material content variations. Furthermore, 91% of the studied QDs exhibit a polarization axis along the crystal [1-100] axis, with the other 9% polarized orthogonal to this direction. These features give non-polar InGaN QDs unique advantages in polarization control over other materials, such as conventional polar nitride, InAs, or CdSe QDs. Hence, the ability to generate single photons with polarization control makes non-polar InGaN QDs highly attractive for quantum cryptography protocols.

  1. Beam Characterization of 10-MV Photon Beam from Medical Linear Accelerator without Flattening Filter.

    Science.gov (United States)

    Shimozato, Tomohiro; Aoyama, Yuichi; Matsunaga, Takuma; Tabushi, Katsuyoshi

    2017-01-01

    This work investigated the dosimetric properties of a 10-MV photon beam emitted from a medical linear accelerator (linac) with no flattening filter (FF). The aim of this study is to analyze the radiation fluence and energy emitted from the flattening filter free (FFF) linac using Monte Carlo (MC) simulations. The FFF linac was created by removing the FF from a linac in clinical use. Measurements of the depth dose (DD) and the off-axis profile were performed using a three-dimensional water phantom with an ionization chamber. A MC simulation for a 10-MV photon beam from this FFF linac was performed using the BEAMnrc code. The off-axis profiles for the FFF linac exhibited a chevron-like distribution, and the dose outside the irradiation field was found to be lower for the FFF linac than for a linac with an FF (FF linac). The DD curves for the FFF linac included many contaminant electrons in the build-up region. Therefore, for clinical use, a metal filter is additionally required to reduce the effects of the electron contamination. The mean energy of the FFF linac was found to be lower than that of the FF linac owing to the absence of beam hardening caused by the FF.

  2. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Science.gov (United States)

    Tian, Y.; Shimazoe, K.; Yan, X.; Ueda, O.; Ishikura, T.; Fujiwara, T.; Uesaka, M.; Ohno, M.; Tomita, H.; Yoshihara, Y.; Takahashi, H.

    2016-09-01

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  3. Highly non-linear solid core photonic crystal fiber with one nano hole

    Science.gov (United States)

    Gangwar, Rahul Kumar; Bhardwaj, Vanita; Singh, Vinod Kumar

    2015-08-01

    The numerical study of newly designed solid core photonic crystal fiber (SCPCF) having three hexagonal air hole rings in cladding region and one small nano hole at the center are presented. By using full vectorial finite element method (FV-FEM), we analyses the optical properties like effective area, nonlinearity and confinement loss of the proposed PCF. Results show that the change in core diameter controls the effective area, nonlinearity and confinement loss. A low effective area (3.34 µm2), high nonlinearity (36.34 W-1km-1) and low confinement loss (0.00106 dB/km) are achieved at the communication wavelength 1.55 µm for the SCPCF having core air hole diameter 0.10 µm, cladding air holes diameter 1.00 µm and pitch 2.50 µm. This type of PCF is very useful in non-linear applications such as supercontinuum generation, four wave mixing, second harmonic generation etc.

  4. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Y., E-mail: cycjty@sophie.q.t.u-tokyo.ac.jp [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Shimazoe, K.; Yan, X. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ueda, O.; Ishikura, T. [Fuji Electric Co., Ltd., Fuji, Hino, Tokyo 191-8502 (Japan); Fujiwara, T. [National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Uesaka, M.; Ohno, M. [Nuclear Professional School, the University of Tokyo, 2-22 Shirakata-shirane, Tokai, Ibaraki 319-1188 (Japan); Tomita, H. [Department of Quantum Engineering, Nagoya University, Furo, Chikusa, Nagoya 464-8603 (Japan); Yoshihara, Y. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Takahashi, H. [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2016-09-11

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  5. The Variation of Surface Dose by Beam Spoiler in 10 MV Photon Beam from Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Seong Cheol; Kim, Jun Ho; Lee, Choul Soo [Dept. of Radiation Oncology, Kosin University Gospel Hospital, Busan (Korea, Republic of)

    2006-03-15

    The purpose of this study is to find a optimal beam spoiler condition on the dose distribution near the surface, when treating a squamous cell carcinoma of the head and neck and a lymphatic region with 10 MV photon beam. The use of a optimal spoiler allows delivering high dose to a superficial tumor volume, while maintaining the skin-sparing effect in the area between the surface to the depth of 0.4 cm. The lucite beam spoiler, which were a tissue equivalent, were made and placed between the surface and the photon collimators of linear accelerator. The surface-dose, the dose at the depth of 0.4 cm, and the maximum dose at the dmax were measured with a parallel-plate ionization chamber for 5 x 5 cm to 30 x 30 cm{sup 2} field sizes using lucite spoilers with different thicknesses at varying skin-to-spoiler separation (SSS). In the same condition, the dose was measured with bolus and compared with beam spoiler. The spoiler increased the surface and build-up dose and shifted the depth of maximum dose toward the surface. With a 10 MV x-ray beam and a optimal beam spoiler when treating a patient, a similar build-up dose with a 6 MV photon beam could be achieved, while maintaining a certain amount of skin spring. But it was provided higher surface dose under SSS of less than 5 cm, the spoiler thickness of more than 1.8 cm or more, and larger field size than 20 x 20 cm{sup 2} provided higher surface dose like bolus and obliterated the spin-sparing effect. the effects of the beam spoiler on beam profile was reduced with increasing depths. The lucite spoiler allowed using of a 10 MV photon beam for the radiation treatment of head and neck caner by yielding secondary scattered electron on the surface. The dose at superficial depth was increased and the depth of maximum dose was moved to near the skin surface. Spoiling the 10 MV x-ray beam resulted in treatment plans that maintained dose homogeneity without the consequence of increased skin reaction or treat volume underdose

  6. Experimental constraints on non-linearities induced by two-photon effects in elastic and inelastic Rosenbluth separations

    Energy Technology Data Exchange (ETDEWEB)

    Vladas Tvaskis; John Arrington; Michael Christy; Rolf Ent; Cynthia Keppel; Yongguang Liang; Grahame Vittorini

    2006-01-26

    The effects of two-photon exchange corrections, suggested to explain the difference between measurements of the proton elastic electromagnetic form factors using the polarization transfer and Rosenbluth techniques, have been studied in elastic and inelastic scattering data. Such corrections could introduce epsilon-dependent non-linearities in inelastic Rosenbluth separations, where epsilon is the virtual photon polarization parameter. It is concluded that such non-linear effects are consistent with zero for elastic, resonance, and deep-inelastic scattering for all Q{sup 2} and W{sup 2} values measured.

  7. Observation of polarised hard X-ray emission from the Crab by the PoGOLite Pathfinder

    CERN Document Server

    Chauvin, M; Jackson, M; Kamae, T; Kawano, T; Kiss, M; Kole, M; Mikhalev, V; Moretti, E; Olofsson, G; Rydström, S; Takahashi, H; Iyudin, A; Arimoto, M; Fukazawa, Y; Kataoka, J; Kawai, N; Mizuno, T; Ryde, F; Tajima, H; Takahashi, T; Pearce, M

    2015-01-01

    We have measured the linear polarisation of hard X-ray emission from the Crab in a previously unexplored energy interval, 20-120 keV. The introduction of two new observational parameters, the polarisation fraction and angle stands to disentangle geometrical and physical effects, thereby providing information on the pulsar wind geometry and magnetic field environment. Measurements are conducted using the PoGOLite Pathfinder - a balloon-borne polarimeter. Polarisation is determined by measuring the azimuthal Compton scattering angle of incident X-rays in an array of plastic scintillators housed in an anticoincidence well. The polarimetric response has been characterised prior to flight using both polarised and unpolarised calibration sources. We address possible systematic effects through observations of a background field. The measured polarisation fraction for the integrated Crab light-curve is ($18.4^{+9.8}_{-10.6}$)%, corresponding to an upper limit (99% credibility) of 42.4%, for a polarisation angle of ($...

  8. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

  9. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    This book covers modern photonics accessibly and discusses the basic physical principles underlying all the applications and technology of photonicsThis volume covers the basic physical principles underlying the technology and all applications of photonics from statistical optics to quantum optics. The topics discussed in this volume are: Photons in perspective; Coherence and Statistical Optics; Complex Light and Singular Optics; Electrodynamics of Dielectric Media; Fast and slow Light; Holography; Multiphoton Processes; Optical Angular Momentum; Optical Forces, Trapping and Manipulation; Pol

  10. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible cov

  11. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying thescience and technology of nanophotonics, its materials andstructures This volume presents nanophotonic structures and Materials.Nanophotonics is photonic science and technology that utilizeslight/matter interactions on the nanoscale where researchers arediscovering new phenomena and developing techniques that go wellbeyond what is possible with conventional photonics andelectronics.The topics discussed in this volume are: CavityPhotonics; Cold Atoms and Bose-Einstein Condensates; Displays;E-paper; Graphene; Integrated Photonics; Liquid Cry

  12. Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

    CERN Document Server

    Alekseev, M; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Austregisilio, A; Badelek, B; Balestra, F; Ball, J; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, M P; Chapiro, A; Chiosso, M; Chung, S U; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Dafni, T; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Diaz, V; Dinkelbach, A M; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Efremov, A; El Alaoui, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger, M., jr; Fischer, H; Franco, C; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gobbo, B; Goertz, S; Grabmuller, S; Grajek, O A; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; Hagemann, R; von Harrach, D; Hasegawa, T; Heckmann, J; Heinsius, F H; Hermann, R; Herrmann, F; Hess, C; Hinterberger, F; von Hodenberg, M; Horikawa, N; Hoppner, Ch; d'Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuss, E; Kafer, W; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kiefer, J; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Komissarov, E V; Kondo, K; Konigsmann, Kay; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kowalik, K; Kramer, M; Kral, A; Kroumchtein, Z V; Kuhn, R; Kunne, F; Kurek, K; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Marroncle, J; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Maximov, A N; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J; Negrini, S; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panebianco, S; Panzieri, D; Parsamyan, B; Paul, S; Pawlukiewicz-Kaminska, B; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Quintans, C; Rajotte, J.-F; Ramos, S; Rapatsky, V; Reicherz, G; Reggiani, D; Richter, A; Robinet, F; Rocco, E; Rondio, E; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Santos, H; Sapozhnikov, M G; Sarkar, S; Savin, Igor A; Sbrizza, G; Schiavon, P; Schill, C; Schmitt, L; Schroder, W; Shevchenko, O.Yu; Siebert, H.-W; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Takekawa, S; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Venugopal, G; Virius, M; Vlassov, N V; Vossen, A; Weitzel, Q; Wenzl, K; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhao, J; Zhuravlev, N; Zvyagin, A

    2009-01-01

    The gluon polarisation in the nucleon has been determined by detecting charm production via D0 meson decay to charged K and pi in polarised muon scattering off a longitudinally polarised deuteron target. The data were taken by the COMPASS Collaboration at CERN between 2002 and 2006 and corresponds to an integrated luminosity of 2.8 fb^-1. The dominant underlying process of charm production is the photon-gluon fusion to a cc-bar pair. A leading order QCD approach gives an average gluon polarisation of (Delta g/g)_x= -0.49 +- 0.27(stat) +- 0.11(syst) at a scale mu^2 ~ 13 (GeV/c)^2 and at an average gluon momentum fraction (x) ~ 0.11. The longitudinal cross-section asymmetry for D0 production is presented in bins of the transverse momentum and the energy of the D0 meson.

  13. Measurement of the charged-pion polarisability at COMPASS

    CERN Document Server

    CERN. Geneva

    2015-01-01

    For more than a decade, COMPASS has been tackling the measurement of the electromagnetic polarizability of the charged pion, which describes the stiffness of the pion against deformation in electromagnetic fields. Previous experiments date back to the 1980's in Serpukhov (Russia), where the Primakoff method for realizing interactions of charged pions with quasi-real photons was first employed. Later also other techniques in photon-nucleon and photon-photon collisions were carried out at different machines. The COMPASS measurement demonstrates that the charged-pion polarizability is significantly smaller than the previous results, roughly by a factor two, with the smallest uncertainties realized so far. The pion polarisability is of fundamental interest in the low-energy sector of quantum chromodynamics. It is directly linked to the quark-gluon substructure and dynamics of the pion, the lightest bound system of strong interaction.

  14. Singularities of the second-harmonic light field polarisation arising upon reflection of normally incident elliptically polarised Gaussian beam from the surface of an isotropic chiral medium

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, K S; Makarov, Vladimir A; Perezhogin, I A; Potravkin, N N [Department of Physics, M.V. Lomonosov Moscow State University (Russian Federation)

    2011-11-30

    We have analysed the conditions for the appearance of polarisation singularities in the second-harmonic beam cross section arising in the case of reflection of a uniformly elliptically polarised Gaussian beam at the fundamental frequency from the surface of an isotropic gyrotropic medium. It is shown that there are elliptical polarisation states of the incident light at which the cross section of the second-harmonic reflected beam contains either one or two C lines and either two, or one, or none L lines [the loci of the points where the propagating radiation is circularly (C) or linearly (L) polarised].The formulas determining the conditions for the occurrence of L and C lines and specifying their orientation in the plane of the cross-section of the second-harmonic beam are obtained.

  15. Cottingham formula and nucleon polarisabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gasser, J.; Leutwyler, H. [Universitaet Bern, Albert Einstein Center for Fundamental Physics, Institut fuer theoretische Physik, Bern (Switzerland); Hoferichter, M. [Universitaet Bern, Albert Einstein Center for Fundamental Physics, Institut fuer theoretische Physik, Bern (Switzerland); Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, ExtreMe Matter Institute EMMI, Darmstadt (Germany); University of Washington, Institute for Nuclear Theory, Seattle, WA (United States); Rusetsky, A. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany)

    2015-08-15

    The difference between the electromagnetic self-energies of proton and neutron can be calculated with the Cottingham formula, which expresses the self-energies as an integral over the electroproduction cross sections - provided the nucleon matrix elements of the current commutator do not contain a fixed pole. We show that, under the same proviso, the subtraction function occurring in the dispersive representation of the virtual Compton forward scattering amplitude is determined by the cross sections. The representation in particular leads to a parameter-free sum rule for the nucleon polarisabilities. We evaluate the sum rule for the difference between the electric polarisabilities of proton and neutron by means of the available parameterisations of the data and compare the result with experiment. (orig.)

  16. Spin-SILC: CMB polarisation component separation with spin wavelets

    Science.gov (United States)

    Rogers, Keir K.; Peiris, Hiranya V.; Leistedt, Boris; McEwen, Jason D.; Pontzen, Andrew

    2016-08-01

    We present Spin-SILC, a new foreground component separation method that accurately extracts the cosmic microwave background (CMB) polarisation E and B modes from raw multifrequency Stokes Q and U measurements of the microwave sky. Spin-SILC is an internal linear combination method that uses spin wavelets to analyse the spin-2 polarisation signal P = Q + iU. The wavelets are additionally directional (non-axisymmetric). This allows different morphologies of signals to be separated and therefore the cleaning algorithm is localised using an additional domain of information. The advantage of spin wavelets over standard scalar wavelets is to simultaneously and self-consistently probe scales and directions in the polarisation signal P = Q + iU and in the underlying E and B modes, therefore providing the ability to perform component separation and E-B decomposition concurrently for the first time. We test Spin-SILC on full-mission Planck simulations and data and show the capacity to correctly recover the underlying cosmological E and B modes. We also demonstrate a strong consistency of our CMB maps with those derived from existing component separation methods. Spin-SILC can be combined with the pseudo- and pure E-B spin wavelet estimators presented in a companion paper to reliably extract the cosmological signal in the presence of complicated sky cuts and noise. Therefore, it will provide a computationally-efficient method to accurately extract the CMB E and B modes for future polarisation experiments.

  17. Polarisation properties of OH emission in planetary nebulae

    CERN Document Server

    Gomez, Jose F; Green, James A; Miranda, Luis F; Suarez, Olga; Bendjoya, Philippe

    2016-01-01

    We present the interferometric, full-polarisation observations of the four ground-state transitions of OH, toward five confirmed and one candidate OH-emitting planetary nebulae (OHPNe). OHPNe are believed to be very young PNe, and information on their magnetic fields (provided by their polarisation) could be key to understand the early evolution of PNe. We detect significant circular and linear polarisation in four and two objects, respectively. Possible Zeeman pairs are seen in JaSt 23 and IRAS 17393-2727, resulting in estimates of magnetic field strengths between 0.8 and 24 mG. We also report the new detection of OH emission at 1720 MHz toward Vy 2-2, making it the third known PN with this type of emission. We suggest that younger PNe have spectra dominated by narrow maser features and higher degrees of polarisation. Shock-excited emission at 1720 MHz seems to be more common in PNe than in early evolutionary phases, and could be related to equatorial ejections during the early PN phase.

  18. Generation of High Purity Photon-Pair in a Short Highly Non-Linear Fiber

    Science.gov (United States)

    2013-01-01

    of entangled photon pairs in optical fiber attracted enormous interest due to its better spatial mode definition and inherent compatibility with...existing fiber optics technologies for long distance transmission, storage and processing. Entangled photon pair generation in optical fiber is...nonlinear microstructure fiber (HNMSF) [7]. In contrast, entangled photon pair generation at telecom wavelengths via SFWM using highly nonlinear fiber

  19. An efficient stable optical polariser module for calibration of the S4UVN earth observation satellite

    Science.gov (United States)

    Rolt, Stephen; Calcines, Ariadna; Lomanowski, Bartosz; Bramall, David; Shaw, Benjamin

    2016-07-01

    We describe here an optical polariser module intended to deliver well characterised polarised light to an imaging spectrometer instrument. The instrument in question is the Sentinel-4/UVN Earth observation imaging spectrometer due to be deployed in 2019 in a geostationary orbit. The polariser module described here will be used in the ground based calibration campaign for this instrument. One critical task of the calibration campaign will be the highly accurate characterisation of the polarisation sensitivity of instrument. The polariser module provides a constant, uniform source of linearly polarised light whose direction can be adjusted without changing the output level or uniformity of the illumination. A critical requirement of the polariser module is that the illumination is uniform across the exit pupil. Unfortunately, a conventional Glan-Taylor arrangement cannot provide this uniformity due to the strong variation in transmission at a refractive surface for angles close to the critical angle. Therefore a modified prism arrangement is proposed and this is described in detail. Detailed tolerance modelling and straylight modelling is also reported here.

  20. Homodyne measurement of average photon number

    CERN Document Server

    Webb, J G; Huntington, E H

    2005-01-01

    We describe a new scheme for the measurement of mean photon flux at an arbitrary optical sideband frequency using homodyne detection. Experimental implementation of the technique requires an AOM in addition to the homodyne detector, and does not require phase locking. The technique exhibits polarisation, frequency and spatial mode selectivity, as well as much improved speed, resolution and dynamic range when compared to linear photodetectors and avalanche photo diodes (APDs), with potential application to quantum state tomography and information encoding using an optical frequency basis. Experimental data also directly confirms the Quantum Mechanical description of vacuum noise.

  1. Digital filter based on the Fisher linear discriminant to reduce dead-time paralysis in photon counting

    Science.gov (United States)

    Sullivan, Shane Z.; Schmitt, Paul D.; DeWalt, Emma L.; Muir, Ryan D.; Simpson, Garth J.

    2013-03-01

    Photon counting represents the Poisson limit in signal to noise, but can often be complicated in imaging applications by detector paralysis, arising from the finite rise / fall time of the detector upon photon absorption. We present here an approach for reducing dead-time by generating a deconvolution digital filter based on optimizing the Fisher linear discriminant. In brief, two classes are defined, one in which a photon event is initiated at the origin of the digital filter, and one in the photon event is non-coincident with the filter origin. Linear discriminant analysis (LDA) is then performed to optimize the digital filter that best resolves the coincident and non-coincident training set data.1 Once trained, implementation of the filter can be performed quickly, significantly reducing dead-time issues and measurement bias in photon counting applications. Experimental demonstration of the LDA-filter approach was performed in fluorescence microscopy measurements using a highly convolved impulse response with considerable ringing. Analysis of the counts supports the capabilities of the filter in recovering deconvolved impulse responses under the conditions considered in the study. Potential additional applications and possible limitations are also considered.

  2. Realization of compact broadband optical diode in linear air-hole photonic crystal waveguide.

    Science.gov (United States)

    Ye, Han; Yu, Zhongyuan; Liu, Yumin; Chen, Zhihui

    2016-10-17

    In this paper, we present a compact broadband design for reciprocal optical diode in linear two-dimensional air-hole photonic crystal waveguide. The forward even-to-odd mode conversion and backward blockade of even mode are achieved by introducing the functional region with 1.2a×2.8a area. The inside dielectric distribution is obtained by finite element method combining geometry projection method and the method of moving asymptotes. In our design, only one asymmetrically deformed air hole locates in the functional region. The parabola-like unidirectionality keeps higher than 15dB within the operational bandwidth 0.01c/a (about 40nm when 1550nm is the center wavelength), and the maximum value reaches approximate 24 dB near the center frequency. Meanwhile, the forward transmission efficiency keeps higher than 89.9%. Moreover, the optical diode effect of the proposed design is validated in three-dimensional model and the tolerance of the imperfection in fabricating is demonstrated as well. This compact broadband optical diode can contribute to the all-optical integrated circuits.

  3. Highly non-linear solid core photonic crystal fiber with one nano hole

    Energy Technology Data Exchange (ETDEWEB)

    Gangwar, Rahul Kumar, E-mail: rahul0889@gmail.com; Bhardwaj, Vanita, E-mail: bhardwajphy12@gmail.com; Singh, Vinod Kumar, E-mail: singh.vk.ap@ismdhanbad.co.in [Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand (India)

    2015-08-28

    The numerical study of newly designed solid core photonic crystal fiber (SCPCF) having three hexagonal air hole rings in cladding region and one small nano hole at the center are presented. By using full vectorial finite element method (FV-FEM), we analyses the optical properties like effective area, nonlinearity and confinement loss of the proposed PCF. Results show that the change in core diameter controls the effective area, nonlinearity and confinement loss. A low effective area (3.34 µm{sup 2}), high nonlinearity (36.34 W{sup −1}km{sup −1}) and low confinement loss (0.00106 dB/km) are achieved at the communication wavelength 1.55 µm for the SCPCF having core air hole diameter 0.10 µm, cladding air holes diameter 1.00 µm and pitch 2.50 µm. This type of PCF is very useful in non-linear applications such as supercontinuum generation, four wave mixing, second harmonic generation etc.

  4. WIMP search in the mono-photon channel at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Habermehl, Moritz [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2016-07-01

    The International Linear Collider (ILC) is a planned electron-positron collider with √(s) tunable from 250 to 500 GeV, with a possible upgrade to 1 TeV. Besides precision measurements of the Higgs boson its physics goals comprise searches for physics beyond the Standard Model, e.g. searches for Dark Matter. This collider search assumes the production of WIMPs in pairs. They are not visible in the detector but the energy carried away can be observed via an additional (''tag'') particle. Photon emission from the initial state leads to the almost model independent signature: e{sup +}e{sup -} → χχγ. As this analysis tests couplings between WIMPs and leptons it is complementary to analogues searches at the LHC. A precise study is facilitated by the clean environment of lepton colliders with small systematics of electroweak backgrounds. While the conceptual feasibility and the sensitivity reach of the ILC have been shown in the past, this talk focusses on the consequences for the detector design. The requirements for the central detector as well as for the instrumentation of the forward region are discussed in the context of the ILD detector concept.

  5. Photoproduction of $\\Lambda$ and $\\Sigma^0$ hyperons using linearly polarized photons

    CERN Document Server

    Paterson, C A; Livingston, K; McKinnon, B

    2016-01-01

    Background: Measurements of polarization observables for the reactions $\\vec{\\gamma} p \\rightarrow K^+ \\Lambda$ and $\\vec{\\gamma} p \\rightarrow K^+ \\Sigma^0$ have been performed. This is part of a programme of measurements designed to study the spectrum of baryon resonances. Purpose: The accurate measurement of several polarization observables provides tight constraints for phenomenological fits. Beam-recoil observables for the $\\vec{\\gamma} p \\rightarrow K^+ \\Sigma^0$ reaction have not been reported before now. Method: The measurements were carried out using linearly polarized photon beams and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71\\,GeV $

  6. Photon undulatory non-linear conversion diagnostic method for caries detection: a pilot study.

    Science.gov (United States)

    Kesler, G; Masychev, V; Sokolovsky, A; Alexandrov, M; Kesler, A; Koren, R

    2003-08-01

    The objective of this study was to evaluate a new optical method - photon undulatory non-linear conversion (PNC)--for use in different stages of caries detection. Caries should be considered an infectious disease managed by risk assessment, early detection, and preventive therapies, rather than simply "drilling and filling." Fluorescence emission spectroscopy was performed in vitro on 90 extracted teeth, with intact occlusal surfaces. This system differs from the basic Diagnodent unit in its ability to distinguish between different tissue components with respect to their spectrums. Histological analysis served as the gold standard for verification. The teeth sections correspond to the specific point with the highest reading of the detector. The system was compared to visual inspection, probing, and x-ray methods. The system tested (helium-neon [He-Ne], lambda = 633 nm) has a fiber optic device that delivers radiation to the tooth and a spectrophotometer device that detects bacterial porphyrins fluorescence, allowing detection of caries, fillings, and calculus by simultaneous measurement of backscattering and fluorescence intensity. The system tested provides quantitatively reproducible measurements and detection even through sound enamel of more than 1 mm in thickness. The PNC method detects different stages of caries lesions in real time, and it exceeds x-rays in sensitivity, without any ionizing radiation. Preliminary results showed a high potential of using the PNC method in clinical practice (98% accuracy) in comparison to the other methods.

  7. Neutron scattering from polarised proton domains

    CERN Document Server

    Van den Brandt, B; Kohbrecher, J; Konter, J A; Mango, S; Glattli, H; Leymarie, E; Grillo, I; May, R P; Jouve, H; Stuhrmann, H B; Stuhrmann, H B; Zimmer, O

    2002-01-01

    Time-dependent small-angle polarised neutron scattering from domains of polarised protons has been observed at the onset of dynamic nuclear polarisation in a frozen solution of 98% deuterated glycerol-water at 1 K containing a small concentration of paramagnetic centres (EHBA-Cr sup V). Simultaneous NMR measurements show that the observed scattering arises from protons around the Cr sup V -ions which are polarised to approx 10% in a few seconds, much faster than the protons in the bulk. (authors)

  8. Probabilistic teleportation scheme of two-mode entangled photon states by using linear optic element

    Institute of Scientific and Technical Information of China (English)

    XIANG Shao-hua

    2003-01-01

    A scheme for teleporting two-mode entangled photon states with the successful probability 33.3% is proposed. In the scheme, the teleporte d qubit is two-mode photon entangled states, and two pairs of EPR pair are used as quantum channel between a sender and a receiver. This procedure is achieved by using two 50/50 symmetric beam splitters and four photon number detectors wit h the help of classical information.

  9. Polarised antibranes from Smarr relations

    CERN Document Server

    Cohen-Maldonado, Diego; Gautason, Fridrik Freyr

    2016-01-01

    We study the backreaction of smeared and localised anti M2-branes placed at the tip of the CGLP background. To this end we derive a Smarr relation for backreacted antibranes at zero and finite temperature. For extremal antibranes we show that if smeared they cannot have regular horizons, whereas localised M2-branes can potentially be regular when polarised into M5-branes, in agreement with the probe result of Klebanov and Pufu. We further discuss antibranes at finite temperature and argue that localised antibrane solutions with regular horizons are not excluded.

  10. Inclusion in a Polarised World

    OpenAIRE

    Freeman, Alan

    2005-01-01

    This paper on inclusion was presented to the at the 2005 summer school of DEEEP (Development Education Exchange in Europe Project), Härnösand - Sweden, 5 - 12 June 2005. It addresses the significance of the concept of world civilisation. It assesses how meaning may be attached to the concept of inclusion in an economically polarised world. It develops a critique of the conception of economic inclusion, by means of an exploration of linguistic inclusion and the notion of ‘disability’. ‘...

  11. Polarisation of Social Studies Textbooks in Pakistan

    Science.gov (United States)

    Zaidi, Syed Manzar Abbas

    2011-01-01

    This article looks at the evolution of the social studies curricula in Pakistan, which are of critical importance in shaping the outlook of many young Pakistanis, who are affected by this polarised discourse. The author argues that this trend of polarisation springing from dynamics of education also effectively contributes to a widening social…

  12. Exciton-polaritons in lattices: A non-linear photonic simulator

    Science.gov (United States)

    Amo, Alberto; Bloch, Jacqueline

    2016-10-01

    Microcavity polaritons are mixed light-matter quasiparticles with extraordinary nonlinear properties, which can be easily accessed in photoluminescence experiments. Thanks to the possibility of designing the potential landscape of polaritons, this system provides a versatile photonic platform to emulate 1D and 2D Hamiltonians. Polaritons allow transposing to the photonic world some of the properties of electrons in solid-state systems, and to engineer Hamiltonians for photons with novel transport properties. Here we review some experimental implementations of polariton Hamiltonians using lattice geometries. xml:lang="fr"

  13. Infrared polarisation measurements of surface and buried anti-personnel landmines

    NARCIS (Netherlands)

    Cremer, F.; Jong, W. de; Schutte, K.

    2001-01-01

    Linear polarisation of Thermal InfraRed (TIR) radiation occurs whenever radiation is reflected or emitted from a smooth surface (such as the top of a landmine) and observed from a grazing angle. The background (soil and vegetation) is generally much rougher and therefore has less pronounced linear p

  14. Automatic and accurate measurements of P-wave and S-wave polarisation properties with a weighted multi-station complex polarisation analysis

    Science.gov (United States)

    de Meersman, K.; van der Baan, M.; Kendall, J.-M.; Jones, R. H.

    2003-04-01

    We present a weighted multi-station complex polarisation analysis to determine P-wave and S-wave polarisation properties of three-component seismic array data. Complex polarisation analysis of particle motion on seismic data was first introduced by Vidale (1986). In its original form, the method is an interpretation of the eigenvalue decomposition of a 3 by 3, complex data-covariance matrix. We have extended the definition of the data-covariance matrix (C) to C=X^HW-1 X, where C now is a 3n by 3n symmetric complex covariance matrix, with n the number of included three-component (3C) stations. X is the data matrix, the columns of which are the analytic signals of the Northern, Eastern and vertical components of the subsequent 3C stations. X^H is the transpose of the complex conjugate of X and W is a diagonal weighting matrix containing the pre-arrival noise levels of all components and all stations. The signals used in the data-matrix are corrected for arrival time differences. The eigenvectors and eigenvalues of C now describe the polarisation properties within the selected analysis window for all included stations. The main advantages of this approach are a better separation of signal and noise in the covariance matrix and the measurement of signal polarisation properties that are not influenced by the presence of polarised white noise. The technique was incorporated in an automated routine to measure the P-wave and S-wave polarisation properties of a microseismic data-set. The data were recorded in the Valhall oilfield in 1998 with a six level 3C vertical linear array with geophones at 20 m intervals between depths of 2100 m and 2200 m. In total 303 microseismic events were analysed and the results compared with manual interpretations. This comparison showed the advantage and high accuracy of the method.

  15. Double-slit vacuum polarisation effects in ultra-intense laser fields

    CERN Document Server

    King, B; Keitel, C H; 10.1103/PhysRevA.82.032114

    2013-01-01

    The influence of the strong laser-driven vacuum on a propagating electromagnetic probe wave has been studied in detail. We investigate two scenarios comprising a focused probe laser beam passing through a region of vacuum polarised by an ultra-intense laser field. By splitting this strong field into two, separated, monochromatic Gaussian pulses counter-propagating in a plane perpendicular to the probe field axis, we demonstrate a leading order light-by-light diffraction effect that generates an interference pattern reminiscent of the classic double-slit experiment. We calculate the total number of probe photons diffracted as well as the number diffracted into regions where the vacuum polarisation signal is higher than the probe background. In addition, we calculate the induced ellipticity and polarisation rotation in the probe beam and show how, in the realistic situation in which the centres of the two strong fields are not exactly aligned, certain ranges of beam separation and observation distance may actua...

  16. PoGOLite measurement of Crab polarisation and future plans

    Science.gov (United States)

    Pearce, Mark

    2016-07-01

    (For the PoGOLite Collaboration) The PoGOLite Pathfinder is a balloon-borne hard X-ray polarimeter designed for the observation of bright, ~1 Crab, sources. Polarisation is determined by measuring the azimuthal Compton scattering angle of incident X-rays in an array of plastic scintillators housed in an BGO anticoincidence well. The PoGOLite Pathfinder was launched from the SSC Esrange Space Centre in July 2013 resulting in a near-circumpolar flight of two weeks duration. The linear polarisation of hard X-ray emissions from the Crab was measured in a previously unexplored energy interval, 20-120 keV. The polarimetric response was characterised prior to flight using both polarised and unpolarised calibration sources. Systematic effects were addressed through observations of a background field. An upgraded polarimeter, PoGO+, is scheduled to fly in summer 2016 from Esrange. Results from the 2013 Pathfinder flight and prospects for the 2016 flight will be discussed.

  17. Spin-SILC: CMB polarisation component separation with spin wavelets

    CERN Document Server

    Rogers, Keir K; Leistedt, Boris; McEwen, Jason D; Pontzen, Andrew

    2016-01-01

    We present Spin-SILC, a new foreground component separation method that accurately extracts the cosmic microwave background (CMB) polarisation $E$ and $B$ modes from raw multifrequency Stokes $Q$ and $U$ measurements of the microwave sky. Spin-SILC is an internal linear combination method that uses spin wavelets to analyse the spin-2 polarisation signal $P = Q + iU$. The wavelets are additionally directional (non-axisymmetric). This allows different morphologies of signals to be separated and therefore the cleaning algorithm is localised using an additional domain of information. The advantage of spin wavelets over standard scalar wavelets is to simultaneously and self-consistently probe scales and directions in the polarisation signal $P = Q + iU$ and in the underlying $E$ and $B$ modes, therefore providing the ability to perform component separation and $E$-$B$ decomposition concurrently for the first time. We test Spin-SILC on full-mission Planck simulations and data and show the capacity to correctly reco...

  18. The photoproduction of φ-mesons off protons by using a beam of linearly polarized photons at threshold energies

    Science.gov (United States)

    Salamanca Bernal, Julian Andres

    Observables from vector meson photoproduction by linearly-polarized photons can be expressed in term of bilinear combinations of helicity amplitudes parameterized by the Spin Density Matrix Elements (SDMEs). These SDMEs give straightforward relations for understanding the nature of the parity exchange at threshold energies, as well as for extracting signatures of the Okubo-Zweig-Iizuka violation. Measurement of SDMEs for g⃗ p →φp in the photon energy range of 1.7 to 1.9 GeV (momentum transfer squared t range of -1.2 to -0.25 GeV2) and 1.9 to 2.1 GeV (t range of -1.4 to -0.25 GeV 2) from the g8b experimental data collected in the summer of 2005 in the Hall B of Jefferson Lab are reported herein.

  19. Signatures of chaotic and non-chaotic-like behaviour in a non-linear quantum oscillator through photon detection

    CERN Document Server

    Everitt, M J; Stiffell, P B; Ralph, J F; Bulsara, A R; Harland, C J

    2005-01-01

    The driven non-linear duffing osillator is a very good, and standard, example of a quantum mechanical system from which classical-like orbits can be recovered from unravellings of the master equation. In order to generated such trajectories in the phase space of this oscillator in this paper we use a the quantum jumps unravelling together with a suitable application of the correspondence principle. We analyse the measured readout by considering the power spectra of photon counts produced by the quantum jumps. Here we show that localisation of the wave packet from the measurement of the oscillator by the photon detector produces a concomitant structure in the power spectra of the measured output. Furthermore, we demonstrate that this spectral analysis can be used to distinguish between different modes of the underlying dynamics of the oscillator.

  20. Observation of M1 resonance in sup 2 sup 0 sup 6 Pb using a highly linear polarized photon beam

    CERN Document Server

    Ohgaki, H; Noguchi, T; Sugiyama, S; Mikado, T; Yamada, K; Suzuki, R; Ohdaira, T; Sei, N; Yamazaki, T

    1999-01-01

    More than twenty M1 states were discovered in sup 2 sup 0 sup 6 Pb from 6.5 to 8.1 MeV with a high-resolution NRF experiment that used a highly linear-polarized photon beam generated by laser-Compton backscattering. The total reduced transition probability of sigma B(M1 arrow up) = 17.4+-5.6 mu sup 2 sub N agreed well with QPM calculation (16.1 mu sup 2 sub N) and previous tagged photon experiment (19 +- 2 mu sup 2 sub N). A fine structure of two bumps at 7.2 and 7.9 MeV which was reproduced reasonably by the QPM calculation was clearly observed in the isovector M1 strength distribution.

  1. Optical Bloch oscillations of an Airy beam in a photonic lattice with a linear transverse index gradient.

    Science.gov (United States)

    Xiao, Fajun; Li, Baoran; Wang, Meirong; Zhu, Weiren; Zhang, Peng; Liu, Sheng; Premaratne, Malin; Zhao, Jianlin

    2014-09-22

    We theoretically report the existence of optical Bloch oscillations (BO) of an Airy beam in a one-dimensional optically induced photonic lattice with a linear transverse index gradient. The Airy beam experiencing optical BO shows a more robust non-diffracting feature than its counterparts in free space or in a uniform photonic lattice. Interestingly, a periodical recurrence of Airy shape accompanied with constant alternation of its acceleration direction is also found during the BO. Furthermore, we demonstrate that the period and amplitude of BO of an Airy beam can be readily controlled over a wide range by varying the index gradient and/or the lattice period. Exploiting these features, we propose a scheme to rout an Airy beam to a predefined output channel without losing its characteristics by longitudinally modulating the transverse index gradient.

  2. COMPASS Results on Gluon Polarisation from High pT hadron pairs

    CERN Document Server

    Silva, L

    2010-01-01

    One of the goals of the COMPASS experiment is the determination of the gluon polarisation \\Delta G/G, for a deep understanding of the spin structure of the nucleon. In DIS the gluon polarisation can be measured via the Photon-Gluon-Fusion (PGF) process, identified by open charm production or by selecting high p_T hadron pairs in the final state. The data used for this work were collected by the COMPASS experiment during the years 2002-2004, using a 160 GeV naturally polarised positive muon beam scattering on a polarised nucleon target. A new preliminary result of the gluon polarisation \\Delta G/G from high p_T hadron pairs in events with Q^2>1 (GeV/c)^2 is presented. In order to extract \\Delta G/G, this analysis takes into account the leading process \\gamma q contribution together with the PGF and QCD Compton processes. A new weighted method based on a neural network approach is used. A preliminary \\Delta G/G result for events from quasi-real photoproduction (Q^2<1 (GeV/c)^2) is also presented.

  3. Determination of the gluon polarisation from open charm production at COMPASS

    CERN Document Server

    Koblitz, Susanne

    2009-01-01

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon. It is determined from spin asymmetries in the scattering of 160 GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. The PGF-process can be tagged through hadrons with high transverse momenta or through charmed hadrons in the final state. The advantage of the open charm channel is that, in leading order, the PGF-process is the only process for charm production, thus no physical background contributes to the selected data sample. This thesis presents a measurement of the gluon polarisation from the COMPASS data taken in the years 2002-2004. In the analysis, charm production is tagged through a reconstructed D0-meson decaying in $D^{0}-> K^{-}pi^{+}$ (and charge conjugates). The reconstruction is done on a combinatorial basis. The background of wrong track pairs is reduced using kinematic cuts to the reconstruc...

  4. Polarisation-sensitive optical elements in azobenzene polyesters and peptides

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Dam-Hansen, Carsten; Berg, Rolf Henrik;

    2006-01-01

    In this article, we describe fabrication of polarisation holographic optical elements in azobenzene polyesters. Both liquid crystalline and amorphous side-chain polyesters have been utilised. Diffractive optical elements such as lenses and gratings that are sensitive to the polarisation...... of the incident light have been fabricated with polarisation holography. Computer-generated optical elements and patterns have also been written with a single polarised laser beam. Recording of polarisation defects enabling easy visualisation is also shown to be feasible in azobenzene polyesters....

  5. The Polarised $\\Lambda$ production in QCD

    CERN Document Server

    Ravindran, V

    1996-01-01

    The $Q^2$ evolution of polarised parton fragmentation functions is disc= ussed using Altarelli-Parisi evolution equations. The first moments of both pol= arised quark and gluon fragmentation functions are shown to behave in a similar fashion at very high energies. This analysis is applicable to any hard processes involving production of polarised hadrons. The polarised $\\Lamb= da$ hyperon production in $e^+~e^-$ annihilation where this can be realised i= s considered. We present a complete $\\alpha_s(Q^2)$ corrections to the asymmetries discussed in the paper of Burkardt and Jaffe which demonstrat= es the extraction of various polarised fragmentation functions. To this order, t= hese corrections are found to be scheme dependent similar to that of structure functions.

  6. Precision manipulation of the neutron polarisation vector

    Energy Technology Data Exchange (ETDEWEB)

    Lelievre-Berna, E. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)]. E-mail: lelievre@ill.fr; Brown, P.J. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Tasset, F. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Kakurai, K. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Takeda, M. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Regnault, L.-P. [CEA - DRFMC/SPSMS/MDN, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2007-07-15

    The rotation of the neutron polarisation vector that takes place on scattering is determined with polarimeters which can measure the three components of the scattered polarisation for any chosen incident polarisation direction. Cryopad zero-field polarimeters are used on the D3/ILL diffractometer and the IN14/ILL, IN20/ILL, IN22/CEA and TAS-1/JAEA three-axis spectrometers. MuPAD zero-field polarimeters have also recently been built for use at the cold neutron beam MIRA/FRM-II and the three-axis spectrometer TASP/SINQ. We present the experimental strategy of this technique called spherical neutron polarimetry (SNP), develop the equations that relate the polarisation components to the CRYOPAD rotation angles, and explain the uncertainties that must be taken into account when carrying out SNP experiments.

  7. Linear optical quantum metrology with single photons: exploiting spontaneously generated entanglement to beat the shot-noise limit.

    Science.gov (United States)

    Motes, Keith R; Olson, Jonathan P; Rabeaux, Evan J; Dowling, Jonathan P; Olson, S Jay; Rohde, Peter P

    2015-05-01

    Quantum number-path entanglement is a resource for supersensitive quantum metrology and in particular provides for sub-shot-noise or even Heisenberg-limited sensitivity. However, such number-path entanglement has been thought to be resource intensive to create in the first place--typically requiring either very strong nonlinearities, or nondeterministic preparation schemes with feedforward, which are difficult to implement. Very recently, arising from the study of quantum random walks with multiphoton walkers, as well as the study of the computational complexity of passive linear optical interferometers fed with single-photon inputs, it has been shown that such passive linear optical devices generate a superexponentially large amount of number-path entanglement. A logical question to ask is whether this entanglement may be exploited for quantum metrology. We answer that question here in the affirmative by showing that a simple, passive, linear-optical interferometer--fed with only uncorrelated, single-photon inputs, coupled with simple, single-mode, disjoint photodetection--is capable of significantly beating the shot-noise limit. Our result implies a pathway forward to practical quantum metrology with readily available technology.

  8. In Vivo Non Linear Optical (NLO) Imaging in Live Rabbit Eyes Using the Heidelberg Two-Photon Laser Ophthalmoscope

    Science.gov (United States)

    Hao, Ming; Flynn, Kevin; Nien-Shy, Chyong; Jester, Bryan E.; Winkler, Moritz; Brown, Donald J.; La Schiazza, Olivier; Bille, Josef; Jester, James V.

    2010-01-01

    Imaging of non-linear optical (NLO) signals generated from the eye using ultrafast pulsed lasers has been limited to the study of ex vivo tissues because of the use of conventional microscopes with slow scan speeds. The purpose of this study was to evaluate the ability of a novel, high scan rate ophthalmoscope to generate NLO signals using an attached femtosecond laser. NLO signals were generated and imaged in live, anesthetized albino rabbits using a newly designed Heidelberg Two-Photon Laser Ophthalmoscope with attached 25 mW femtosecond laser having a central wavelength of 780 nm, pulsewidth of 75 fs, and a repetition rate of 50 MHz. To assess two-photon excited fluorescent (TPEF) signal generation, cultured rabbit corneal fibroblasts (RCF) were first labeled by Blue-green fluorescent FluoSpheres (1 μm diameter) and then cells were micro-injected into the central cornea. Clumps of RCF cells could be detected by both reflectance and TPEF imaging at 6 hours after injection. By 6 days, RCF containing fluorescent microspheres confirmed by TPEF showed a more spread morphology and had migrated from the original injection site. Overall, this study demonstrates the potential of using NLO microscopy to sequentially detect TPEF signals from live, intact corneas. We conclude that further refinement of the Two-photon laser Ophthalmoscope should lead to the development of an important, new clinical instrument capable of detecting NLO signals from patient corneas. PMID:20558159

  9. Polarised bremsstrahlung nuclear resonance fluorescence set-up at the 15 MeV linac in Gent

    Science.gov (United States)

    Govaert, K.; Mondelaers, W.; Jacobs, E.; De Frenne, D.; Persyn, K.; Pommé, S.; Yoneama, M.-L.; Lindenstruth, S.; Huber, K.; Jung, A.; Starck, B.; Stock, R.; Wesselborg, C.; Heil, R.-D.; Kneissl, U.; Pitz, H. H.

    1994-01-01

    Nuclear resonance fluorescence experiments using unpolarised as well as off-axis linearly polarised bremsstrahlung represent an outstanding tool to determine in a completely model independent way transition probabilities, multipole orders and parities of electromagnetic transitions to bound states in nuclei. A new polarised bremsstrahlung facility has been constructed at the 15 MeV linac in Gent. The experimental arrangement is discussed and first results are presented.

  10. The lay-out of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    V I Telnov

    2007-12-01

    One of the interaction regions at the linear colliders should be compatible both with + - and , modes of operation. In this paper, the differences in requirements and possible design solutions are discussed.

  11. The history of polarisation measurements: their role in studies of magnetic fields

    Science.gov (United States)

    Wielebinski, R.

    2015-03-01

    Radio astronomy gave us new methods to study magnetic fields. Synchrotron radiation, the main cause of comic radio waves, is highly linearly polarised with the `E' vector normal to the magnetic field. The Faraday Effect rotates the `E' vector in thermal regions by the magnetic field in the line of sight. Also the radio Zeeman Effect has been observed.

  12. Polarised Drell-Yan measurements at COMPASS

    Directory of Open Access Journals (Sweden)

    Chiosso Michela

    2015-01-01

    Full Text Available Much of the information that exists today about Transverse Momentum Dependent Parton Distribution Functions (TMDs comes from SIDIS measurements with unpolarised and polarised beams and targets where they appear convoluted with fragmentation functions (FFs. Drell-Yan (DY measurements are complementary to those by SIDIS experiments, as they allow to measure convolutions of only Parton Distribution Functions (PDFs without involving FFs. Moreover, given the T-odd character of both Sivers and Boer-Mulders functions, the sign of these TMDs is expected to be reversed when observed from SIDIS or from DY. Measurements of SIDIS were performed by Compass in the period 2002 to 2007 and in 2010, using a naturally polarised µ+ beam and a solid state target polarised either longitudinally or transversely with respect to the beam direction. Now the COMPASS Experiment has the unique opportunity to access TMDs from single-polarised Drell-Yan processes as well, in the same kinematical domain of the SIDIS data and with the same experimental setup; it will allow to test the TMDs universality and the sign change prediction for the first time. We present here the upcoming polarised DY measurements at COMPASS.

  13. Optical polarisation of the Crab pulsar: precision measurements and comparison to the radio emission

    CERN Document Server

    Słowikowska, Agnieszka; Kramer, Michael; Stefanescu, Alexander

    2009-01-01

    The linear polarisation of the Crab pulsar and its close environment was derived from observations with the high-speed photo-polarimeter OPTIMA at the 2.56-m Nordic Optical Telescope in the optical spectral range (400 - 750 nm). Time resolution as short as 11 microseconds, which corresponds to a phase interval of 1/3000 of the pulsar rotation, and high statistics allow the derivation of polarisation details never achieved before. The degree of optical polarisation and the position angle correlate in surprising details with the light curves at optical wavelengths and at radio frequencies of 610 and 1400 MHz. Our observations show that there exists a subtle connection between presumed non-coherent (optical) and coherent (radio) emissions. This finding supports previously detected correlations between the optical intensity of the Crab and the occurrence of giant radio pulses. Interpretation of our observations require more elaborate theoretical models than those currently available in the literature.

  14. The polarisation correction for space-borne grating spectrometers

    Science.gov (United States)

    Zhao, Fa-cai; Sun, Quan-she; Chen, Kun-feng; Zhu, Xing-bang; Wang, Shao-shui; Wang, Guo-quan; Zheng, Xiang-liang; Han, Zhong

    2014-02-01

    Satellite measurements of backscattered sunlight contain essential information about the global distribution of atmospheric constituents. Light reflected from the Earth's atmosphere is linearly or partially linearly polarized because of scattering of unpolarized sunlight by air molecules and aerosols. In the ultraviolet and visible part of the spectrum, measurements of space-borne grating spectrometers are in general sensitive to the state of polarization of the observed light. The interaction of polarized light with polarization-sensitive optical devices yields a different radiance that is measured by the detectors than the radiance that enters the instrument. In the OMI and the SBUV/2 instruments the problem of instrument polarization sensitivity is avoided because the polarized backscattered sunlight is depolarized before it interacts with the polarization-sensitive optical components. For GOME, SCIAMACHY, and GOME-2 it is intended to eliminate the polarization response of the instrument from the polarization-sensitive measurement. This paper discusses the basic concept of the polarisation correction of the space-borne grating spectrometers by using Mueller matrix calculus. A model was developed using the Mueller Matrices formulation to evaluate the polarization sensitivity of the space-borne grating spectrometers. The optical components are treated as general diattenuators with phase retardance. The correction for this polarization sensitivity is based on broadband polarization measurements. Accurate preflight polarisation calibration of space-borne grating spectrometers is essential for the observational objectives of the instrument, and a special facility has been developed in order to allow the instrument to be calibrated.

  15. Double polarisation experiments in meson photoproduction

    CERN Document Server

    ,

    2016-01-01

    One of the remaining challenges within the standard model is to gain a good understanding of QCD in the non-perturbative regime. A key step towards this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon resonances. To gain access to resonances with small $\\pi N$ partial width, photoproduction experiments provide essential information. Partial wave analyses need to be performed to extract the contributing resonances. Here, a complete experiment is required to unambiguously determine the contributing amplitudes. This involves the measurement of carefully chosen single and double polarisation observables. In a joint endeavour by MAMI, ELSA, and Jefferson Laboratory, a new generation of experiments with polarised beams, polarised proton and neutron targets, and $4\\pi$ particle detectors have been performed in recent years. Many results of unprecedented quality were recently published by all three experiments, and included by the various partial wave analysis groups in their analy...

  16. Exclusive ω meson muoproduction on transversely polarised protons

    Science.gov (United States)

    Adolph, C.; Aghasyan, M.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anfimov, N. V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C. D. R.; Badełek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Chang, W.-C.; Chatterjee, C.; Chiosso, M.; Choi, I.; Chung, S.-U.; Cicuttin, A.; Crespo, M. L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F. H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.-Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jörg, P.; Kabuß, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O. M.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lian, Y.-S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G. K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G. V.; Meyer, M.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Mitrofanov, E.; Mitrofanov, N.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Nový, J.; Nowak, W.-D.; Nukazuka, G.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pešek, M.; Peshekhonov, D. V.; Pierre, N.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Ryabchikov, D. I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Steffen, D.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Wallner, S.; Weisrock, T.; Wilfert, M.; ter Wolbeek, J.; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-02-01

    Exclusive production of ω mesons was studied at the COMPASS experiment by scattering 160 GeV / c muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality 1 (GeV / c) 2

  17. Optical Sampling at 80 Gbit/s Using a Highly Non-Linear Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    Andrea Tersigni; Vanessa Calle; Anders Clausen; Palle Jeppesen; Kim P. Hansen; Jacob R. Folkenberg

    2003-01-01

    Optical sampling using four-wave mixing in 50m of newly developed highly non-linear photo niccrystal fiber has been achieved at 80 Gbit/s with an Extinction Ratio of 12 dB. A basic characterization is also included.

  18. Measurement of W Polarisation at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2003-01-01

    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \\sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \\pm 0.027 \\pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation.

  19. Approximate solutions to a nonintegrable problem of propagation of elliptically polarised waves in an isotropic gyrotropic nonlinear medium, and periodic analogues of multisoliton complexes

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, V A; Petnikova, V M; Potravkin, N N; Shuvalov, V V [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2014-02-28

    Using the linearization method, we obtain approximate solutions to a one-dimensional nonintegrable problem of propagation of elliptically polarised light waves in an isotropic gyrotropic medium with local and nonlocal components of the Kerr nonlinearity and group-velocity dispersion. The consistent evolution of two orthogonal circularly polarised components of the field is described analytically in the case when their phases vary linearly during propagation. The conditions are determined for the excitation of waves with a regular and 'chaotic' change in the polarisation state. The character of the corresponding nonlinear solutions, i.e., periodic analogues of multisoliton complexes, is analysed. (nonlinear optical phenomena)

  20. Non-linear mixing in coupled photonic crystal nanobeam cavities due to cross-coupling opto-mechanical mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Daniel, E-mail: daniel.ramos@csic.es; Frank, Ian W.; Deotare, Parag B.; Bulu, Irfan; Lončar, Marko [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2014-11-03

    We investigate the coupling between mechanical and optical modes supported by coupled, freestanding, photonic crystal nanobeam cavities. We show that localized cavity modes for a given gap between the nanobeams provide weak optomechanical coupling with out-of-plane mechanical modes. However, we show that the coupling can be significantly increased, more than an order of magnitude for the symmetric mechanical mode, due to optical resonances that arise from the interaction of the localized cavity modes with standing waves formed by the reflection from thesubstrate. Finally, amplification of motion for the symmetric mode has been observed and attributed to the strong optomechanical interaction of our hybrid system. The amplitude of these self-sustained oscillations is large enough to put the system into a non-linear oscillation regime where a mixing between the mechanical modes is experimentally observed and theoretically explained.

  1. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    CERN Document Server

    Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2016-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...

  2. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    CERN Document Server

    Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...

  3. Linear and nonlinear photonic Jackiw-Rebbi states in interfaced binary waveguide arrays

    Science.gov (United States)

    Tran, Truong X.; Biancalana, Fabio

    2017-07-01

    We study analytically and numerically the optical analog of the Jackiw-Rebbi states in quantum-field theory. These solutions exist at the interface of two binary waveguide arrays, which are described by two Dirac equations with masses of opposite sign. We show that these special states are topologically robust not only in the linear regime, but also in the nonlinear one (with both focusing and defocusing nonlinearities). We also reveal that one can effectively generate Jackiw-Rebbi states starting from Dirac solitons.

  4. Constraining Direction-Dependent Instrumental Polarisation: A New Technique for Polarisation Angle Calibration

    CERN Document Server

    Farnes, J S

    2014-01-01

    Direction-dependent instrumental polarisation introduces wide-field polarimetric aberrations and limits the dynamic range of low-frequency interferometric images. We therefore provide a detailed two-dimensional analysis of the Giant Metrewave Radio Telescope (GMRT) primary beam in full-Stokes at 325 MHz and 610 MHz. We find that the directional dependence is essentially independent of the feed and is dominated by the curvature of the dishes reflecting mesh. The developed beam models are used to reduce wide-field instrumental polarisation in 610 MHz observations by subtracting the expected response from the $uv$-data itself. Furthermore, a new technique for polarisation angle calibration is presented that allows for calibration using an unpolarised source and therefore can be implemented at arbitrarily low observational frequencies. This technique has the advantage that it calibrates the polarisation angle independently of ionospheric Faraday rotation and source variability. It also removes the need for known ...

  5. Ideal-observer detectability in photon-counting differential phase-contrast imaging using a linear-systems approach

    Energy Technology Data Exchange (ETDEWEB)

    Fredenberg, Erik; Danielsson, Mats; Stayman, J. Webster; Siewerdsen, Jeffrey H.; Aslund, Magnus [Research and Development, Philips Women' s Healthcare, Smidesvaegen 5, SE-171 41 Solna, Sweden and Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering and Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Research and Development, Philips Women' s Healthcare, Smidesvaegen 5, SE-171 41 Solna (Sweden)

    2012-09-15

    Purpose: To provide a cascaded-systems framework based on the noise-power spectrum (NPS), modulation transfer function (MTF), and noise-equivalent number of quanta (NEQ) for quantitative evaluation of differential phase-contrast imaging (Talbot interferometry) in relation to conventional absorption contrast under equal-dose, equal-geometry, and, to some extent, equal-photon-economy constraints. The focus is a geometry for photon-counting mammography. Methods: Phase-contrast imaging is a promising technology that may emerge as an alternative or adjunct to conventional absorption contrast. In particular, phase contrast may increase the signal-difference-to-noise ratio compared to absorption contrast because the difference in phase shift between soft-tissue structures is often substantially larger than the absorption difference. We have developed a comprehensive cascaded-systems framework to investigate Talbot interferometry, which is a technique for differential phase-contrast imaging. Analytical expressions for the MTF and NPS were derived to calculate the NEQ and a task-specific ideal-observer detectability index under assumptions of linearity and shift invariance. Talbot interferometry was compared to absorption contrast at equal dose, and using either a plane wave or a spherical wave in a conceivable mammography geometry. The impact of source size and spectrum bandwidth was included in the framework, and the trade-off with photon economy was investigated in some detail. Wave-propagation simulations were used to verify the analytical expressions and to generate example images. Results: Talbot interferometry inherently detects the differential of the phase, which led to a maximum in NEQ at high spatial frequencies, whereas the absorption-contrast NEQ decreased monotonically with frequency. Further, phase contrast detects differences in density rather than atomic number, and the optimal imaging energy was found to be a factor of 1.7 higher than for absorption

  6. Pre-conditioned Backward Monte Carlo solutions to radiative transport in planetary atmospheres. Fundamentals: Sampling of propagation directions in polarising media

    CERN Document Server

    Muñoz, García; Mills,; P, F

    2014-01-01

    Context. The interpretation of polarised radiation emerging from a planetary atmosphere must rely on solutions to the vector Radiative Transport Equation (vRTE). Monte Carlo integration of the vRTE is a valuable approach for its flexible treatment of complex viewing and/or illumination geometries and because it can intuitively incorporate elaborate physics. Aims. We present a novel Pre-Conditioned Backward Monte Carlo (PBMC) algorithm for solving the vRTE and apply it to planetary atmospheres irradiated from above. As classical BMC methods, our PBMC algorithm builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. Methods. We show that the neglect of polarisation in the sampling of photon propagation directions in classical BMC algorithms leads to unstable and biased solutions for conservative, optically-thick, strongly-polarising media such as Rayleigh atmospheres. The numerical difficulty is avoid...

  7. Radiosurgery with photon beams; Physical aspects and adequacy of linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Podgorsak, E.B.; Pla, M.; Souhami, L. (McGill University, Montreal (Canada). Department of Radiation Oncology); Pike, G.B.; Olivier, A. (McGill University, Montreal (Canada). Department of Neurosurgery)

    1990-03-01

    The question of the adequacy of isocentric linear accelerators (linacs) for use in radiosurgery is addressed. The general physical requirements for radiosurgery, mainly a high spatial and numerical accuracy of dose delivery, reasonable treatment time, and low skin and leakage dose as well as cost considerations are examined. Various linac-based procedures are analyzed in view of their ability to meet these requirements and are contrasted with the clinically proven system of the Gamma unit. It is shown that the linac-based multiple converging arcs techniques and the dynamic rotation meet the stringent physical requirements on dose delivery and are thus viable alternatives to radiosurgery with the commercially available and dedicated Gamma unit. (author). 15 refs.; 2 figs.; 1 tab.

  8. Polarisation of electroweak gauge bosons at the LHC

    Directory of Open Access Journals (Sweden)

    Vryonidou Eleni

    2013-05-01

    Full Text Available We present results for the polarisation of gauge bosons produced at the LHC. Polarisation effects for W bosons manifest themselves in the angular distributions of the lepton and in the distributions of lepton transverse momentum and missing transverse energy. The polarisation is discussed for a range of different processes producing W bosons such as W+jets and W from top production. The relative contributions of the different polarisation states vary from process to process, reflecting the dynamics of the underlying hardscattering process. We also calculate the polarisation of the Z boson produced in association with QCD jets at the LHC.

  9. Polarisation of electroweak gauge bosons at the LHC

    CERN Document Server

    Stirling, James

    2013-01-01

    We present results for the polarisation of gauge bosons produced at the LHC. Polarisation effects for W bosons manifest themselves in the angular distributions of the lepton and in the distributions of lepton transverse momentum and missing transverse energy. The polarisation is discussed for a range of different processes producing W bosons such as W+jets and W from top production. The relative contributions of the different polarisation states vary from process to process, reflecting the dynamics of the underlying hard-scattering process. We also calculate the polarisation of the Z boson produced in association with QCD jets at the LHC.

  10. Does circular polarisation reveal the rotation of quasar engines?

    CERN Document Server

    Ensslin, T A

    2003-01-01

    Many radio sources like quasars, blazars, radio galaxies, and micro-quasars exhibit circular polarisation (CP) with surprising temporal persistent handedness. As a possible explanation we propose that the CP is due to Faraday conversion (FC) of linear polarisation synchrotron light which propagates along a line-of-sight (LOS) through twisted magnetic fields. The rotational nature of accretion flows onto black holes naturally generates the required magnetic twist in the emission region, independent of whether it is a jet or an ADAF. The expected twist in both types of flows is of the order of what is required for optimal CP generation, relaxing constraints on the plasma parameters, that were given in scenarios which rely on Faraday rotation (FR). The mechanism works in electron-positron (e+/e-) as well as electron-proton (e/p) plasma. In the latter case, the emission region should consist of individual flux tubes with independent polarities in order to suppress too strong FR. The predominant CP is expected to ...

  11. Observing the polarisation pattern of Saturn using CARMA

    CERN Document Server

    Aich, Moumita; Moodley, Kavilan; Sievers, Jonathan; Hedman, Matthew M

    2015-01-01

    We observe Saturn and its ring system at wavelengths of 1.3 mm (220 GHz) using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) interferometric array. We study the intensity and polarisation structure of the planet and present the best polarisation data of Saturn at these frequencies. Observations using CARMA E-array configuration exhibited some anomalous polarisation pattern in the rings. We provide details of our analysis and discuss the possibility of self gravity wakes in Saturn's ring system resulting in this anomaly. We observe Venus in intensity and polarisation to cross-check the levels of polarisation signal detectable by CARMA. We also discuss how limitations in CARMA instrumental accuracy for observing weakly polarised sources, project this signature as an upper bound of polarisation measurements of Saturn using CARMA.

  12. Extrapolation chamber mounted on perspex for calibration of high energy photon and electron beams from a clinical linear accelerator

    Directory of Open Access Journals (Sweden)

    Ravichandran R

    2009-01-01

    Full Text Available The objective of the present study is to establish radiation standards for absorbed doses, for clinical high energy linear accelerator beams. In the nonavailability of a cobalt-60 beam for arriving at Nd, water values for thimble chambers, we investigated the efficacy of perspex mounted extrapolation chamber (EC used earlier for low energy x-rays and beta dosimetry. Extrapolation chamber with facility for achieving variable electrode separations 10.5mm to 0.5mm using micrometer screw was used for calibrations. Photon beams 6 MV and 15 MV and electron beams 6 MeV and 15 MeV from Varian Clinac linacs were calibrated. Absorbed Dose estimates to Perspex were converted into dose to solid water for comparison with FC 65 ionisation chamber measurements in water. Measurements made during the period December 2006 to June 2008 are considered for evaluation. Uncorrected ionization readings of EC for all the radiation beams over the entire period were within 2% showing the consistency of measurements. Absorbed doses estimated by EC were in good agreement with in-water calibrations within 2% for photons and electron beams. The present results suggest that extrapolation chambers can be considered as an independent measuring system for absorbed dose in addition to Farmer type ion chambers. In the absence of standard beam quality (Co-60 radiations as reference Quality for Nd,water the possibility of keeping EC as Primary Standards for absorbed dose calibrations in high energy radiation beams from linacs should be explored. As there are neither Standard Laboratories nor SSDL available in our country, we look forward to keep EC as Local Standard for hospital chamber calibrations. We are also participating in the IAEA mailed TLD intercomparison programme for quality audit of existing status of radiation dosimetry in high energy linac beams. The performance of EC has to be confirmed with cobalt-60 beams by a separate study, as linacs are susceptible for minor

  13. Two-, three-, and four-photon ionization of Mg in the circularly and linearly polarized laser fields: Comparative study using the Hartree-Fock and model potentials

    CERN Document Server

    Buica, Gabriela; 10.1016/j.jqsrt.2007.05.004

    2013-01-01

    We theoretically study multiphoton ionization of Mg in the circularly as well as the linearly polarized laser fields. Specifically two-, three-, and four-photon ionization cross sections from the ground and first excited states are calculated as a function of photon energy. Calculations are performed using the frozen-core Hartree-Fock and also the model potential approaches and the results are compared. We find that the model potential approach provide results as good as or even slightly better than those by the frozen-core Hartree-Fock approach. We also report the relative ratios of the ionization cross sections by the circularly and linearly polarized laser fields as a function of photon energy, which exhibit clear effects of electron correlations.

  14. Modelling the circular polarisation of Earth-like exoplanets: constraints on detecting homochirality

    Science.gov (United States)

    Hogenboom, Michael; Stam, Daphne; Rossi, Loic; Snik, Frans

    2016-04-01

    The circular polarisation of light is a property of electromagnetic radiation from which extensive information can be extracted. It is oft-neglected due to its small signal relative to linear polarisation and the need for advanced instrumentation in measuring it. Additionally, numerical modelling is complex as the full Stokes vector must always be computed. Circular polarisation is commonly induced through the multiple scattering of light by aerosols te{hansen} and multiple reflections of light by rough surfaces te{circplanets}. Most interestingly, distinctive spectral circular polarimetric behaviour is exhibited by light reflected by organisms due to the homochiral molecular structure of all known organisms te{chiralbailey}. Especially fascinating is the unique circular polarimetric behaviour of light reflected by photosynthesising organisms at the absorption wavelength of the chlorophyll pigment te{circpolchar}. This presents the previously unexplored possibility of circular polarimetry as a method for identifying and characterising the presence of organisms, a method which could be applied in the hunt for extraterrestrial life. To date, few telescopes exist that measure circular polarisation and none that have been deployed in space. Observations of the circular polarisation reflected by other planets in the solar system have been made with ground-based telescopes, with significant results te{circplanets}. However, none of these observations have been made at the phase angles at which exoplanets will be observed. Also, none have been made of the Earth, which is the logical starting point for the study of biologically induced circular polarisation signals. This introduces the need for numerical modelling to determine the extent to which circular polarisation is present in light reflected by exoplanets or the Earth. In this study, we model the multiple scattering and reflection of light using the doubling-adding method te{dehaan}. We will present circular

  15. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F. [INFN, Trieste (Italy); Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexeev, M.G. [University of Turin, Department of Physics, Turin (Italy); Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S. [University of Turin, Department of Physics, Turin (Italy); INFN, Turin (Italy); Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d' ; Kunne, F.; Levillain, M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Seder, E.; Thibaud, F. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Augustyniak, W.; Klimaszewski, K.; Kurek, K.; Marianski, B.; Sandacz, A.; Szabelski, A.; Sznajder, P. [National Centre for Nuclear Research, Warsaw (Poland); Austregesilo, A.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Huber, S.; Kraemer, M.; Krinner, F.; Paul, S.; Uhl, S. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Azevedo, C.D.R.; Pereira, F.; Veloso, J. [University of Aveiro, Department of Physics, Aveiro (Portugal); Badelek, B. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Barth, J.; Hahne, D.; Klein, F.; Pretz, J.; Schmieden, H. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Beck, R.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Ketzer, B.; Mikhasenko, M. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bedfer, Y. [CERN, Geneva 23 (Switzerland); CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Bernhard, J. [CERN, Geneva 23 (Switzerland); Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Bicker, K. [CERN, Geneva 23 (Switzerland); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Bielert, E.R.; Mallot, G.K.; Schoenning, K. [CERN, Geneva 23 (Switzerland); Bodlak, M.; Finger, M.; Finger, M. Jr.; Matousek, J.; Pesek, M.; Roskot, M. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M. [LIP, Lisbon (Portugal); Bradamante, F.; Bressan, A.; Dasgupta, S.; Makke, N.; Martin, A.; Sbrizzai, G.; Schiavon, P. [University of Trieste, Department of Physics, Trieste (Italy); INFN, Trieste (Italy); Buechele, M.; Fischer, H.; Gorzellik, M.; Grussenmeyer, T.; Heinsius, F.H.; Herrmann, F.; Joerg, P.; Koenigsmann, K.; Kremser, P.; Nowak, W.D.; Regali, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Szameitat, T.; Wolbeek, J. ter [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Chang, W.C.; Hsieh, C.Y.; Sawada, T. [Academia Sinica, Institute of Physics, Taipei (China); Choi, I.; Giordano, F.; Grosse Perdekamp, M.; Heitz, R.; Kulinich, Y.; Makins, N.; Montuenga, P.; Peng, J.C.; Riedl, C. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, IL (United States); Cicuttin, A.; Crespo, M.L. [INFN, Trieste (Italy); Abdus Salam ICTP, Trieste (Italy); Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L. [Matrivani Institute of Experimental Research and Education, Calcutta (India); Denisov, O.Yu.; Maggiora, A.; Panzieri, D.; Tosello, F. [INFN, Turin (Italy); Donskov, S.V.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D. [State Scientific Center Institute for High Energy Physics of National Research Center ' Kurchatov Institute' , Protvino (Russian Federation); Doshita, N.; Hashimoto, R.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Nukazuka, G.; Suzuki, H. [Yamagata University, Yamagata (Japan); Duic, V. [University of Trieste, Department of Physics, Trieste (Italy); Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Rychter, A.; Zaremba, K.; Ziembicki, M. [Warsaw University of Technology, Institute of Radioelectronics, Warsaw (Poland); Fresne von Hohenesche, N. du; Harrach, D. von; Kabuss, E.; Nerling, F.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Collaboration: COMPASS Collaboration; and others

    2017-04-15

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q{sup 2} > 1 (GeV/c){sup 2}. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised {sup 6}LiD target. By analysing the full range in hadron transverse momentum p{sub T}, the different p{sub T}-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ{sup 2} = left angle Q{sup 2} right angle = 3 (GeV/c){sup 2}. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x{sub g}, covering the range 0.04 < x{sub g} < 0.28 and does not exhibit a significant dependence on x{sub g}. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038{sub (stat.)} ± 0.036{sub (syst.)} at left angle x{sub g} right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x{sub g} range. (orig.)

  16. Measurement of the Tau Polarisation at LEP

    CERN Document Server

    Heister, A; Barate, R; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Merle, E; Pietrzyk, B; Alemany, R; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Graugès-Pous, E; Martínez, M; Merino, G; Miquel, R; Pacheco, A; Ruiz, H; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Azzurri, P; Boix, G; Buchmüller, O L; Cattaneo, M; Cerutti, F; Clerbaux, B; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Greening, T C; Hansen, J B; Harvey, J; Janot, P; Jost, B; Kado, M; Mato, P; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tournefier, E; Ward, J; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Falvard, A; Gay, P; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Blondel, A; Bonneaud, G R; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Halley, A W; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Thompson, A S; Wasserbaech, S R; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Marinelli, N; Sedgbeer, J K; Thompson, J C; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Pearson, M R; Robertson, N A; Giehl, I; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Wachsmuth, H W; Zeitnitz, C; Bonissent, A; Carr, J; Coyle, P; Leroy, O; Payre, P; Rousseau, D; Talby, M; Aleppo, M; Ragusa, F; David, A; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Settles, Ronald; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Davier, M; Duflot, L; Jacholkowska, A; Lefrançois, J; Nikolic, I A; Videau, I; Yuan, C; Bagliesi, G; Boccali, T; Calderini, G; Ciulli, V; Foà, L; Giassi, A; Ligabue, F; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Locci, E; Pérez, P; Rander, J; Roussarie, A; Schwindling, J; Trabelsi, A; Vallage, B; Konstantinidis, N P; Litke, A M; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Misiejuk, A; Ngac, A; Prange, G; Sieler, U; Giannini, G; Rothberg, J E; Armstrong, S R; Cranmer, K; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu, X; Zobernig, G

    2001-01-01

    The polarisation of $\\tau$'s produced in Z decay is measured using 160 pb$^{-1}$ of data accumulated at LEP by the ALEPH detector between 1990 and 1995. The variation of the polarisation with polar angle yields the two parameters ${\\cal A}_e = 0.1504 \\pm 0.0068 $ and ${\\cal A}_{\\tau} = 0.1451 \\pm 0.0059$ which are consistent with the hypothesis of $e$-$\\tau$ universality. Assuming universality, the value ${\\cal A}_{e\\mbox{-}\\tau} = 0.1474 \\pm 0.0045$ is obtained from which the effective weak mixing angle $\\sin^2 {\\theta_{\\mathrm{W}}^{\\mathrm{eff}}} =0.23147 \\pm 0.00057 $ is derived.

  17. W Boson Polarisation at LEP2

    CERN Document Server

    Abbiendi, G; Åkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Büsser, K; Burckhart, H J; Campana, S; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Couchman, J; Csilling, Akos; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krieger, P; Von Krogh, J; Krüger, K; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Layter, J G; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McKenna, J A; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Poli, B; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rosati, S; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2004-01-01

    Elements of the spin density matrix for W bosons in e+e- -> W+W- -> qqln events are measured from data recorded by the OPAL detector at LEP. This information is used calculate polarised differential cross-sections and to search for CP-violating effects. Results are presented for W bosons produced in e+e- collisions with centre-of-mass energies between 183 GeV and 209 GeV. The average fraction of W bosons that are longitudinally polarised is found to be (23.9 +- 2.1 +- 1.1)% compared to a Standard Model prediction of (23.9 +- 0.1)%. All results are consistent with CP conservation.

  18. Optimal Frames for Polarisation State Reconstruction

    CERN Document Server

    Foreman, Matthew R; Aiello, Andrea

    2015-01-01

    Complete determination of the polarisation state of light requires projection of the associated Stokes vector onto a basis of at least four distinct analysis states by means of suitable polarisation state analysers. Stability of state reconstruction in such measurements, however, hinges on the condition number, $\\kappa$, of the corresponding instrument matrix. Optimisation of redundant measurement frames with an arbitrary finite number of analysis states, $m$, is considered in this Letter in the sense of minimisation of $\\kappa$. The minimum achievable $\\kappa$ is analytically found and shown to be independent of $m$, except for $m=5$ where this minimum is unachievable. Formal equivalence between minimisation of $\\kappa$, maximisation of the determinant of the associated Gram matrix and minimisation of the equally weighted variance is established. Distribution of the optimal analysis states over the Poincar\\'e sphere is furthermore found to be described by spherical 2-designs, including those defined by the P...

  19. Triple gauge couplings in polarised e sup - e sup +->W sup - W sup + and their measurement using optimal observables

    CERN Document Server

    Diehl, M; Nagel, F

    2003-01-01

    The sensitivity of optimal integrated observables to electroweak triple gauge couplings is investigated for the process e sup - e sup +->W sup - W sup +->4 fermions at future linear colliders. By a suitable reparameterisation of the couplings we achieve that all 28 coupling parameters have uncorrelated statistical errors and are naturally normalised for this process. Discrete symmetry properties simplify the analysis and allow checks on the stability of numerical results. We investigate the sensitivity to the couplings of the normalised event distribution and the additional constraints that can be obtained from the total rate. Particular emphasis is put on the gain in sensitivity one can achieve with longitudinal beam polarisation. We also point out questions that may best be settled with transversely polarised beams. In particular we find that with purely longitudinal polarisation one linear combination of coupling parameters is hardly measurable by means of the normalised event distribution. (orig.)

  20. Social Polarisation and the Danish Welfare State

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove Valborg

    2007-01-01

    Globalisation and the information society tend - according to leading theories - to increase social polarisation and create dual cities. Studies have shown that the tendencies are more complicated in several of the European cities and the welfare state seems to have an impact on the development. ...... a preliminary picture of Aarhus looking at the distribution of poverty and wealth showing some indicators towards inequality. Furthermore we discuss central theories, concepts and measured indicators...

  1. Double polarisation experiments in meson photoproduction

    Science.gov (United States)

    Hartmann, Jan

    2016-11-01

    One of the remaining challenges within the standard model is to gain a good understanding of QCD in the non-perturbative regime. A key step towards this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon resonances. To gain access to resonances with small πN partial width, photoproduction experiments provide essential information. Partial wave analyses need to be performed to extract the contributing resonances. Here, a complete experiment is required to unambiguously determine the contributing amplitudes. This involves the measurement of carefully chosen single and double polarisation observables. In a joint endeavour by MAMI, ELSA, and Jefferson Laboratory, a new generation of experiments with polarised beams, polarised proton and neutron targets, and 4π particle detectors have been performed in recent years. Many results of unprecedented quality were recently published by all three experiments, and included by the various partial wave analysis groups in their analyses, leading to substantial improvements, e.g. a more precise determination of resonance parameters. An overview of recent results is given, with an emphasis on results from the CBELSA/TAPS experiment, and their impact on our understanding of the nucleon excitation spectrum is discussed.

  2. How to polarise all neutrons in one beam: a high performance polariser and neutron transport system

    Science.gov (United States)

    Rodriguez, D. Martin; Bentley, P. M.; Pappas, C.

    2016-09-01

    Polarised neutron beams are used in disciplines as diverse as magnetism,soft matter or biology. However, most of these applications often suffer from low flux also because the existing neutron polarising methods imply the filtering of one of the spin states, with a transmission of 50% at maximum. With the purpose of using all neutrons that are usually discarded, we propose a system that splits them according to their polarisation, flips them to match the spin direction, and then focuses them at the sample. Monte Carlo (MC) simulations show that this is achievable over a wide wavelength range and with an outstanding performance at the price of a more divergent neutron beam at the sample position.

  3. Is the Long-Term Persistency of Circular Polarisation due to the Constant Helicity of the Magnetic Fields in Rotating Quasar Engines?

    OpenAIRE

    Ensslin, Torsten A.

    2003-01-01

    Many compact radio sources like quasars, blazars, radio galaxies, and micro-quasars emit circular polarisation (CP) with surprising temporal persistent handedness. We propose that the CP is caused by Faraday conversion of linear polarisation synchrotron light which propagates along a line-of-sight through helical magnetic fields. Jet outflows from radio galaxies should have the required magnetic helicity in the emission region due to the magnetic torque of the accretion disc. Also advection d...

  4. Static interaction between electrically polarisable particles in vacuo

    CERN Document Server

    Coïsson, R

    2015-01-01

    The static interaction of a point charge and a polarisable particle and between two polarisable particles is discussed in vacuo, and force and energy considerations are made. In particular a critical distance is shown (in principle) to appear in the two-dipole case, where the polarisation is self- sustained, and above which it disappears and below which it tends to explode. In the case of a polarisable particle with a nonzero charge interacting with a charge (of the same sign) there is a distance where repulsion and attraction are balanced.

  5. Monte Carlo simulation of photonic state tomography: a virtual Hanbury Brown and Twiss correlator

    Science.gov (United States)

    Murray, Eoin; Juska, Gediminas; Pelucchi, Emanuele

    2016-05-01

    This paper provides a theoretical background for the simulations of particular quantum optics experiments, namely, photon intensity correlation measurements. A practical example, adapted to polarisation-entangled photon pairs emitted from a quantum dot, is presented. The tool, a virtual Hanbury Brown and Twiss correlator, simulates polarisation-resolved the second-order correlation functions, which then can be used in a photonic state tomography procedure—a full description of a light source’s polarisation state. This educational tool is meant to improve general understanding of such quantum optics experiments.

  6. Bright optical centre in diamond with narrow, highly polarised and nearly phonon-free fluorescence at room temperature

    Science.gov (United States)

    John, Roger; Lehnert, Jan; Mensing, Michael; Spemann, Daniel; Pezzagna, Sébastien; Meijer, Jan

    2017-05-01

    Using shallow implantation of ions and molecules with masses centred at 27 atomic mass units (amu) in diamond, a new artificial optical centre with unique properties has been created. The centre shows a linearly polarised fluorescence with a main narrow emission line mostly found at 582 nm, together with a weak vibronic sideband at room temperature. The fluorescence lifetime is ∼2 ns and the brightest centres are more than three times brighter than the nitrogen-vacancy centres. A majority of the centres shows stable fluorescence whereas some others present a blinking behaviour, at faster or slower rates. Furthermore, a second kind of optical centre has been simultaneously created in the same diamond sample, within the same ion implantation run. This centre has a narrow zero-phonon line (ZPL) at ∼546 nm and a broad phonon sideband at room temperature. Interestingly, optically detected magnetic resonance (ODMR) has been measured on several single 546 nm centres and two resonance peaks are found at 0.99 and 1.27 GHz. In view of their very similar ODMR and optical spectra, the 546 nm centre is likely to coincide with the ST1 centre, reported once (with a ZPL at 550 nm), but of still unknown nature. These new kinds of centres are promising for quantum information processing, sub-diffraction optical imaging or use as single-photon sources.

  7. Detecting the B-mode Polarisation of the CMB with Clover

    CERN Document Server

    North, C E; Ade, P A R; Audley, M D; Baines, C; Battye, R A; Brown, M L; Cabella, P; Calisse, P G; Challinor, A D; Duncan, W D; Ferreira, P G; Gear, W K; Glowacka, D; Goldie, D J; Grimes, P K; Halpern, M; Haynes, V; Hilton, G C; Irwin, K D; Jones, M E; Lasenby, A N; Leahy, P J; Leech, J; Maffei, B; Mauskopf, P; Melhuish, S J; O'Dea, D; Parsley, S M; Piccirillo, L; Pisano, G; Reintsema, C D; Savini, G; Sudiwala, R; Sutton, D; Taylor, A C; Teleberg, G; Titterington, D; Tsaneva, V; Tucker, C; Watson, R; Withington, S; Yassin, G; Zhang, J

    2008-01-01

    We describe the objectives, design and predicted performance of Clover, which is a ground-based experiment to measure the faint ``B-mode'' polarisation pattern in the cosmic microwave background (CMB). To achieve this goal, clover will make polarimetric observations of approximately 1000 deg^2 of the sky in spectral bands centred on 97, 150 and 225 GHz. The observations will be made with a two-mirror compact range antenna fed by profiled corrugated horns. The telescope beam sizes for each band are 7.5, 5.5 and 5.5 arcmin, respectively. The polarisation of the sky will be measured with a rotating half-wave plate and stationary analyser, which will be an orthomode transducer. The sky coverage combined with the angular resolution will allow us to measure the angular power spectra between 20 < l < 1000. Each frequency band will employ 192 single polarisation, photon noise limited TES bolometers cooled to 100 mK. The background-limited sensitivity of these detector arrays will allow us to constrain the tenso...

  8. A Sino-German 6cm polarisation survey of the Galactic plane - VIII. Small-diameter sources

    CERN Document Server

    Reich, W; Reich, P; Gao, X Y; Xiao, L; Han, J L

    2013-01-01

    Information of small-diameter sources is extracted from the Sino-German 6cm polarisation survey of the Galactic plane carried out with the Urumqi 25-m telescope. We performed two-dimensional elliptical Gaussian fits to the 6cm maps to obtain a list of sources with total-intensity and polarised flux densities. The source list contains 3832 sources with a fitted diameter smaller than 16 arcmin and a peak flux density exceeding 30 mJy, so about 5 times the rms noise, of the total-intensity data. The cumulative source count indicates completeness for flux densities exceeding about 60 mJy. We identify 125 linearly polarised sources at 6cm with a peak polarisation flux density greater than 10 mJy, so about 3 times the rms noise, of the polarised-intensity data. Despite lacking compact steep spectrum sources, the 6cm catalogue lists about 20 percent more sources than the Effelsberg 21cm source catalogue at the same angular resolution and for the same area. Most of the faint 6cm sources must have a flat spectrum and ...

  9. Chemical segregation and self polarisation in ferroelectrics

    Directory of Open Access Journals (Sweden)

    Bernard E. Watts

    2009-06-01

    Full Text Available Chemical partitioning or segregation is commonly encountered in solid-state syntheses. It is driven by compositional, thermal and electric field gradients. These phenomena can be quite extreme in thin films and lead to notable effects on the electrical properties of ferroelectrics. The segregation in ferroelectric thin films will be illustrated and the mechanisms explained in terms of diffusion processes driven by a potential gradient of the oxygen. The hypothesis can also explain self polarisation and imprint in ferroelectric hysteresis.

  10. Determination of the gluon polarisation from open charm production at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Koblitz, Susanne

    2009-01-27

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, {delta}G/G. It is determined from spin asymmetries in the scattering of 160GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. The PGF-process can be tagged through hadrons with high transverse momenta or through charmed hadrons in the final state. The advantage of the open charm channel is that, in leading order, the PGF-process is the only process for charm production, thus no physical background contributes to the selected data sample. This thesis presents a measurement of the gluon polarisation left angle {delta}g/g right angle from the COMPASS data taken in the years 2002-2004. In the analysis, charm production is tagged through a reconstructed D{sup 0}-meson decaying in D{sup 0}{yields} K{sup -}{pi}{sup +} (and charge conjugates). The reconstruction is done on a combinatorial basis. The background of wrong track pairs is reduced using kinematic cuts to the reconstructed D{sup 0}-candidate and the information on particle identification from the Ring Imaging Cerenkov counter. In addition, the event sample is separated into D{sup 0}-candidates, where a soft pion from the decay of the D{sup *}-meson to a D{sup 0}-meson, is found, and the D{sup 0}-candidates without this tag. Due to the small mass difference between D{sup *}-meson and D{sup 0}-meson the signal purity of the D{sup *}-tagged sample is about 7 times higher than in the untagged sample. The gluon polarisation left angle {delta}g/g right angle is measured from the event asymmetries for the for the different spin configurations of the COMPASS target. To improve the statistical precision of the final results, the events in the final sample are weighted. The use of a signal and a background weight allows the separation of left angle {delta}g/g right angle, and a possible asymmetry in the combinatorial

  11. Exclusive ω meson muoproduction on transversely polarised protons

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2017-02-01

    Full Text Available Exclusive production of ω mesons was studied at the COMPASS experiment by scattering 160 GeV/c muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality 1 (GeV/c2

  12. Exclusive $\\omega$ meson muoproduction on transversely polarised protons

    CERN Document Server

    Adolph, C.; Aghasyan, M.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buechele, M.; Chang, W. -C.; Chatterjee, C.; Chiosso, M.; Choi, I.; Chung, S. -U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Duennweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmueller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; dHose, N.; Hsieh, C. -Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Joerg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Koenigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kraemer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lian, Y. -S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, M.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Mitrofanov, E.; Mitrofanov, N.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J. -C.; Pereira, F.; Pesek, M.; Peshekhonov, D.V.; Pierre, N.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schoenning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Steffen, D.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Wallner, S.; Weisrock, T.; Wilfert, M.; ter Wolbeek, J.; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-01-01

    Exclusive production of $\\omega$ mesons was studied at the COMPASS experiment by scattering $160~\\mathrm{GeV}/\\mathit{c}$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality $1~(\\mathrm{GeV}/\\mathit{c})^2 < Q^2 < 10~(\\mathrm{GeV}/\\mathit{c})^2$, Bjorken scaling variable $0.003 < x_{\\mathit{Bj}} < 0.3$ and transverse momentum squared of the $\\omega$ meson $0.05~(\\mathrm{GeV}/\\mathit{c})^2 < p_{T}^{2} < 0.5~(\\mathrm{GeV}/\\mathit{c})^2$. The measured asymmetries are sensitive to the nucleon helicity-flip Generalised Parton Distributions (GPD) $E$ that are related to the orbital angular momentum of quarks, the chiral-odd GPDs $H_{T}$ that are related to the transversity Parton Distribution Functions, and the sign of the $\\pi\\omega$ transition form factor. The results are compared to recent calculations of a GPD-based model.

  13. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Science.gov (United States)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  14. Measurements of {sup 12}C (vector ({gamma}),pp) photon asymmetries for E{sub {gamma}} = 200-450 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.; MacGregor, I.J.D.; Annand, J.R.M.; Codling, R.F.B.; Hamilton, D.; Howdle, D.; Livingston, K.; McGeorge, J.C.; McNicoll, E.F.; Owens, R.O.; Rosner, G. [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Aguar-Bartolome, P.; Akasoy, L.K.; Arends, H.J.; Downie, E.J.; Drexler, P.; Heid, E.; Jahn, O.; Ostrick, M.; Otte, P.B.; Oussena, B.; Schumann, S.; Thomas, A.; Unverzagt, M. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Azimov, Ya.I.; Bekrenev, V.S.; Koulbardis, A.A.; Kruglov, S.P. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Bantawa, K.; Manley, D.M. [Kent State University, Kent, Ohio (United States); Beck, R.; Nikolaev, A. [University of Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Berghaeuser, H.; Gregor, R.; Kotulla, M.; Metag, V.; Novotny, R.; Thiel, M. [University of Giessen, II Physikalisches Institut, Giessen (Germany); Braghieri, A.; Mushkarenkov, A.; Pedroni, P.; Rostomyan, T. [INFN Sezione di Pavia, Pavia (Italy); Branford, D.; Glazier, D.I.; Jude, T.C.; Sikora, M.H.; Tarbert, C.M.; Watts, D.P. [University of Edinburgh, SUPA, School of Physics, Edinburgh (United Kingdom); Briscoe, W.J.; Demissie, B.T.; Strakovsky, I.I. [The George Washington University, Washington, DC (United States); Brudvik, J.; Nefkens, B.M.K.; Prakhov, S.; Starostin, A.; Suarez, I.M. [University of California Los Angeles, Los Angeles, California (United States); Cherepnya, S.; Fil' kov, L.V.; Kashevarov, V.L. [Lebedev Physical Institute, Moscow (Russian Federation); Dieterle, M.; Keshelashvili, I.; Krusche, B.; Oberle, M.; Werthmueller, D.; Witthauer, L. [University of Basel, Institut fuer Physik, Basel (Switzerland); Hornidge, D. [Mount Allison University, Sackville, New Brunswick (Canada); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Supek, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Middleton, D.G. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Mount Allison University, Sackville, New Brunswick (Canada); Sober, D.I. [The Catholic University of America, Washington (United States); Collaboration: The Crystal Ball at MAMI and A2 Collaborations

    2013-05-15

    The {sup 12}C (vector ({gamma}),pp) reaction has been studied in the photon energy range 200-450 MeV at the Mainz microtron MAMI-C, where linearly polarised photons were energy-tagged using the Glasgow-Mainz Tagged Photon Spectrometer and protons were detected in the Crystal Ball detector. The photon asymmetry {Sigma} has been measured over a wider E{sub {gamma}} range than previous measurements. The strongest asymmetries were found at low missing energies where direct emission of nucleon pairs is expected. Cuts on the difference in azimuthal angles of the two ejected protons increased the magnitude of the observed asymmetries. At low missing energies the {Sigma} data exhibit a strong angular dependence, similar to deuteron photodisintegration. (orig.)

  15. 80 Gb/s transmission over 80 km and demultiplexing using a highly non-linear photonic crystal fibre

    DEFF Research Database (Denmark)

    Berg, Kim Skaalum; Oxenløwe, Leif Katsuo; Siahlo, Andrei;

    2002-01-01

    We report on, transmission of an 80 Gb/s signal over 80 km of standard single mode fibre with subsequent demultiplexing to 10 Gb/s in a NOLM containing a novel photonic crystal fibre......We report on, transmission of an 80 Gb/s signal over 80 km of standard single mode fibre with subsequent demultiplexing to 10 Gb/s in a NOLM containing a novel photonic crystal fibre...

  16. Frequency dependence of orthogonal polarisation modes in pulsars

    NARCIS (Netherlands)

    Smits, J.M.; Stappers, B.W.; Edwards, R.T.; Kuijpers, J.; Ramachandran, R.

    2006-01-01

    We have carried out a study of the orthogonal polarisation mode behaviour as afunction of frequency of 18pulsars, using average pulsar data from the European Pulsar Network(EPN). Assuming that the radiation consists of two100% polarised completely orthogonal superposed modes we separated these

  17. Anatomical and physiological evidence for polarisation vision in the nocturnal bee Megalopta genalis.

    Science.gov (United States)

    Greiner, Birgit; Cronin, Thomas W; Ribi, Willi A; Wcislo, William T; Warrant, Eric J

    2007-06-01

    The presence of a specialised dorsal rim area with an ability to detect the e-vector orientation of polarised light is shown for the first time in a nocturnal hymenopteran. The dorsal rim area of the halictid bee Megalopta genalis features a number of characteristic anatomical specialisations including an increased rhabdom diameter and a lack of primary screening pigments. Optically, these specialisations result in wide spatial receptive fields (Deltarho = 14 degrees ), a common adaptation found in the dorsal rim areas of insects used to filter out interfering effects (i.e. clouds) from the sky. In this specialised eye region all nine photoreceptors contribute their microvilli to the entire length of the ommatidia. These orthogonally directed microvilli are anatomically arranged in an almost linear, anterior-posterior orientation. Intracellular recordings within the dorsal rim area show very high polarisation sensitivity and a sensitivity peak within the ultraviolet part of the spectrum.

  18. Polarisation-dependent generation of fs-laser induced periodic surface structures

    Energy Technology Data Exchange (ETDEWEB)

    Gräf, Stephan, E-mail: stephan.graef@uni-jena.de; Müller, Frank A.

    2015-03-15

    Highlights: • LIPSS formation was studied under static and dynamic alteration of laser polarisation. • The dynamic polarisation is based on a continuously rotating E-field vector. • LIPSS generated with static linear polarisation reveal a period of 925 nm. • LIPSS orientation follows the direction of the rotating E-field vector. • The approach facilitates the formation of disordered structures for optical applications. - Abstract: The formation of laser induced periodic surface structures (LIPPS) was investigated on polished stainless steel surfaces under irradiation with fs-laser pulses characterised by a pulse duration τ = 300 fs, a laser wavelength λ = 1025 nm, a repetition frequency f{sub rep} = 250 Hz and a laser fluence F = 1 J/cm{sup 2}. For this purpose line scans with a scanning velocity v = 0.5 mm/s were performed in air environment at normal incidence utilising a well-defined temporal control of the electrical field vector. The generated surface structures were characterised by optical microscopy, by scanning electron microscopy and by atomic force microscopy in combination with Fourier transformation. The results reveal the formation of a homogenous and highly periodic surface pattern of ripples with a period Λ{sub exp} ≈ 925 nm aligned perpendicular to the incident electric field vector for static linear polarisation states. Utilising a motor-driven rotation device it was demonstrated that a continuously rotating electric field vector allows to transfer the originally well-ordered periodic ripples into tailored disordered surface structures that could be of particular interest for e.g. absorbing surfaces, plasmonic enhanced optoelectronic devices and biomedical applications.

  19. Linear spectropolarimetry across the optical spectrum of Herbig Ae/Be stars

    CERN Document Server

    Ababakr, K M; Vink, J S

    2016-01-01

    We present the results of spectropolarimetric observations of 12 Herbig Ae/Be objects. Our data have the largest spectropolarimetric wavelength coverage, 4560 {\\AA} to 9480 {\\AA}, published to date. A change in linear polarisation across the H{\\alpha} line, is detected in all objects. Such a line effect reveals the fact that stellar photons are scattered off free electrons that are not distributed in a spherically symmetric volume, suggesting the presence of small disks around these accreting objects. Thanks to the large wavelength coverage, we can report that H{\\alpha} is the spectral line in the optical wavelength range that is most sensitive to revealing deviations from spherical symmetry, and the one most likely to show a line effect across the polarisation in such cases. Few other spectral lines display changes in polarisation across the line. In addition, H{\\alpha} is the only line which shows an effect across its absorption component in some sources. We present a scenario explaining this finding and de...

  20. Predictions of covariant chiral perturbation theory for nucleon polarisabilities and polarised Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lensky, Vadim, E-mail: lensky@itep.ru [Institut für Kernphysik and PRISMA Cluster of Excellence, Johannes Gutenberg Universität Mainz, 55128, Mainz (Germany); Institute for Theoretical and Experimental Physics, 117218, Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow (Russian Federation); Theoretical Physics Group, School of Physics and Astronomy, University of Manchester, M13 9PL, Manchester (United Kingdom); McGovern, Judith A. [Theoretical Physics Group, School of Physics and Astronomy, University of Manchester, M13 9PL, Manchester (United Kingdom); Pascalutsa, Vladimir [Institut für Kernphysik and PRISMA Cluster of Excellence, Johannes Gutenberg Universität Mainz, 55128, Mainz (Germany)

    2015-12-19

    We update the predictions of the SU(2) baryon chiral perturbation theory for the dipole polarisabilities of the proton, {α_E_1, β_M_1}{sub p}={11.2(0.7), 3.9(0.7)}×10{sup -4} fm{sup 3}, and obtain the corresponding predictions for the quadrupole, dispersive, and spin polarisabilities: {α_E_2, β_M_2}{sub p}={17.3(3.9), -15.5(3.5)}×10{sup -4} fm{sup 5}, {α_E_1_ν, β_M_1_ν}{sub p}={-1.3(1.0), 7.1(2.5)}×10{sup -4} fm{sup 5}, and {γ_E_1_E_1, γ_M_1_M_1,γ_E_1_M_2, γ_M_1_E_2}{sub p}={-3.3(0.8), 2.9(1.5), 0.2(0.2),1.1(0.3)}×10{sup -4} fm{sup 4}. The results for the scalar polarisabilities are in significant disagreement with semi-empirical analyses based on dispersion relations; however, the results for the spin polarisabilities agree remarkably well. Results for proton Compton-scattering multipoles and polarised observables up to the Delta(1232) resonance region are presented too. The asymmetries Σ{sub 3} and Σ{sub 2x} reproduce the experimental data from LEGS and MAMI. Results for Σ{sub 2z} agree with a recent sum rule evaluation in the forward kinematics. The asymmetry Σ{sub 1z} near the pion production threshold shows a large sensitivity to chiral dynamics, but no data is available for this observable. We also provide the predictions for the polarisabilities of the neutron, the numerical values being {α_E_1, β_M_1}{sub n}={13.7(3.1), 4.6(2.7)}×10{sup -4} fm{sup 3}, {α_E_2, β_M_2}{sub n}={16.2(3.7), -15.8(3.6)}×10{sup -4} fm{sup 5}, {α_E_1_ν, β_M_1_ν}{sub n}={0.1(1.0), 7.2(2.5)}×10{sup -4} fm{sup 5}, and {γ_E_1_E_1, γ_M_1_M_1, γ_E_1_M_2, γ_M_1_E_2}{sub n}={-4.7(1.1),2.9(1.5), 0.2(0.2), 1.6(0.4)}×10{sup -4} fm{sup 4}. The neutron dynamical polarisabilities and multipoles are examined too. We also discuss subtleties related to matching the dynamical and static polarisabilities.

  1. Predictions of covariant chiral perturbation theory for nucleon polarisabilities and polarised Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lensky, Vadim [Johannes Gutenberg Universitaet Mainz, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany); Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); University of Manchester, Theoretical Physics Group, School of Physics and Astronomy, Manchester (United Kingdom); McGovern, Judith A. [University of Manchester, Theoretical Physics Group, School of Physics and Astronomy, Manchester (United Kingdom); Pascalutsa, Vladimir [Johannes Gutenberg Universitaet Mainz, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

    2015-12-15

    We update the predictions of the SU(2) baryon chiral perturbation theory for the dipole polarisabilities of the proton, {α_E_1, β_M_1}{sub p} = {11.2(0.7), 3.9(0.7)} x 10{sup -4} fm{sup 3}, and obtain the corresponding predictions for the quadrupole, dispersive, and spin polarisabilities: {α_E_2, β_M_2}{sub p} = {17.3(3.9),.15.5(3.5)} x 10{sup -4} fm{sup 5}, {α_E_1_ν, β_M_1_ν}{sub p} = {-1.3(1.0), 7.1(2.5)} x 10{sup -4} fm{sup 5}, and {γ_E_1_E_1, γ_M_1_M_1, γ_E_1_M_2, γ_M_1_E_2}{sub p} = {-3.3(0.8), 2.9(1.5), 0.2(0.2), 1.1 (0.3)} x 10{sup -4} fm{sup 4}. The results for the scalar polarisabilities are in significant disagreement with semi-empirical analyses based on dispersion relations; however, the results for the spin polarisabilities agree remarkably well. Results for proton Compton-scattering multipoles and polarised observables up to the Delta(1232) resonance region are presented too. The asymmetries Σ{sub 3} and Σ{sub 2x} reproduce the experimental data from LEGS and MAMI. Results for Σ{sub 2z} agree with a recent sum rule evaluation in the forward kinematics. The asymmetry Σ{sub 1z} near the pion production threshold shows a large sensitivity to chiral dynamics, but no data is available for this observable. We also provide the predictions for the polarisabilities of the neutron, the numerical values being {α_E_1, β_M_1}{sub n} = {13.7(3.1), 4.6(2.7)} x 10{sup -4} fm{sup 3}, {α_E_2, β_M_2}{sub n} = {16.2(3.7),.15.8(3.6)} x 10{sup -4} fm{sup 5}, {α_E_1_ν, β_M_1_ν}{sub n} = {0.1(1.0), 7.2(2.5)} x 10{sup -4} fm{sup 5}, and {γ_E_1_E_1, γ_M_1_M_1, γ_E_1_M_2, γ_M_1_E_2}{sub n} = {-4.7(1.1), 2.9(1.5), 0.2(0.2), 1.6(0.4)} x 10{sup -4} fm{sup 4}. The neutron dynamical polarisabilities and multipoles are examined too. We also discuss subtleties related to matching the dynamical and static polarisabilities. (orig.)

  2. Construction of. gamma pi. /sup 0/ spectrometer and photon tagging facility at Bates Linear Accelerator. Final report, July 31, 1979-July 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Booth, E.C.

    1981-08-01

    The funds provided under Contract No. DE-AC02-79ER10486 were totally expended for hardware and supplies required by two related devices at the Bates Linear Accelerator. These were a photon tagging facility and a ..gamma pi../sup 0/ spectrometer in Beam Line C of the new South Experimental Hall. Construction was begun in November of 1979 and both systems became fully operational in the summer of 1981. Preliminary data was taken in 1980 with a prototype ..gamma pi../sup 0/ spectrometer will be carried out in the fall of 1981 and spring of 1982. The photon tagging system has been used successfully to calibrate the ..gamma pi../sup 0/ spectrometer for the BU - MIT collaboration and to test a lead glass detector system for Brandeis University.

  3. Measurement of $\\tau$ polarisation at LEP

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1998-01-01

    Using the data collected with the L3 detector at LEP between 1990 and 1995, corresponding to an integrated luminosity of 149 pb$^{-1}$, the $\\tau$ longitudinal polarisation has been measured as a function of the production polar angle using the $\\tau$ decays \\thad\\ ($\\rm h = \\pi, \\rho, \\aone$) and \\tlep\\ ($\\rm \\ell = e, \\mu$). From this measurement the quantities æl~and \\at, which depend on the couplings of the electron and the $\\tau$ to the Z, are determined to be $\\ael = 0.1678 \\pm 0.0127 \\pm 0.0030 $ and $\\at = 0.1476 \\pm 0.0088 \\pm 0.0062$, consistent with the hypothesis of e--$\\tau$ universality. Under this assumption a value of $\\al = 0.1540 \\pm 0.0074 \\pm 0.0044 $ is obtained, yielding the value of the effective weak mixing angle $\\swsqb = 0.2306 \\pm 0.0011$.

  4. Polarisation analysis on the LET time-of-flight spectrometer

    Science.gov (United States)

    Nilsen, G. J.; Košata, J.; Devonport, M.; Galsworthy, P.; Bewley, R. I.; Voneshen, D. J.; Dalgliesh, R.; Stewart, J. R.

    2017-06-01

    We present a design for implementing uniaxial polarisation analysis on the LET cold neutron time-of-flight spectrometer, installed on the second target station at ISIS. The polarised neutron beam is to be produced by a transmission-based supermirror polariser with the polarising mirrors arranged in a “double-V” formation. This will be followed by a Mezei-type precession coil spin flipper, selected for its small spatial requirements, as well as a permanent magnet guide field to transport the beam polarisation to the sample position. The sample area will contain a set of holding field coils, whose purpose is to produce a highly homogenous magnetic field for the wide-angle 3He analyser cell. To facilitate fast cell changes and reduce the risk of cell failure, we intend to separate the cell and cryostat from the vacuum of the sample tank by installing both in a vessel at atmospheric pressure. When the instrument upgrade is complete, the performance of LET is expected to be commensurate with existing and planned polarised cold neutron spectrometers at other sources. Finally, we discuss the implications of performing uniaxial polarisation analysis only, and identify quasi-elastic neutron scattering (QENS) on ionic conducting materials as an interesting area to apply the technique.

  5. Null point of discrimination in crustacean polarisation vision.

    Science.gov (United States)

    How, Martin J; Christy, John; Roberts, Nicholas W; Marshall, N Justin

    2014-07-15

    The polarisation of light is used by many species of cephalopods and crustaceans to discriminate objects or to communicate. Most visual systems with this ability, such as that of the fiddler crab, include receptors with photopigments that are oriented horizontally and vertically relative to the outside world. Photoreceptors in such an orthogonal array are maximally sensitive to polarised light with the same fixed e-vector orientation. Using opponent neural connections, this two-channel system may produce a single value of polarisation contrast and, consequently, it may suffer from null points of discrimination. Stomatopod crustaceans use a different system for polarisation vision, comprising at least four types of polarisation-sensitive photoreceptor arranged at 0, 45, 90 and 135 deg relative to each other, in conjunction with extensive rotational eye movements. This anatomical arrangement should not suffer from equivalent null points of discrimination. To test whether these two systems were vulnerable to null points, we presented the fiddler crab Uca heteropleura and the stomatopod Haptosquilla trispinosa with polarised looming stimuli on a modified LCD monitor. The fiddler crab was less sensitive to differences in the degree of polarised light when the e-vector was at -45 deg than when the e-vector was horizontal. In comparison, stomatopods showed no difference in sensitivity between the two stimulus types. The results suggest that fiddler crabs suffer from a null point of sensitivity, while stomatopods do not. © 2014. Published by The Company of Biologists Ltd.

  6. Effects of geometry and linearly polarized cavity photons on charge and spin currents in a quantum ring with spin-orbit interactions

    Science.gov (United States)

    Arnold, Thorsten; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar

    2014-05-01

    We calculate the persistent charge and spin polarization current inside a finite-width quantum ring of realistic geometry as a function of the strength of the Rashba or Dresselhaus spin-orbit interaction. The time evolution in the transient regime of the two-dimensional (2D) quantum ring connected to electrically biased semi-infinite leads is governed by a time-convolutionless non-Markovian generalized master equation. The electrons are correlated via Coulomb interaction. In addition, the ring is embedded in a photon cavity with a single mode of linearly polarized photon field, which is polarized either perpendicular or parallel to the charge transport direction. To analyze carefully the physical effects, we compare to the analytical results of the toy model of a one-dimensional (1D) ring of non-interacting electrons with spin-orbit coupling. We find a pronounced charge current dip associated with many-electron level crossings at the Aharonov-Casher phase ΔΦ = π, which can be disguised by linearly polarized light. Qualitative agreement is found for the spin polarization currents of the 1D and 2D ring. Quantitatively, however, the spin polarization currents are weaker in the more realistic 2D ring, especially for weak spin-orbit interaction, but can be considerably enhanced with the aid of a linearly polarized electromagnetic field. Specific spin polarization current symmetries relating the Dresselhaus spin-orbit interaction case to the Rashba one are found to hold for the 2D ring, which is embedded in the photon cavity.

  7. The strange history of polarised neutrons in Australia

    Science.gov (United States)

    Hicks, T. J.

    2016-04-01

    The history of polarised neutrons in Australia is unusual firstly because of the particular access that individuals in universities had to the facilities at the reactor site and because this resulted in the experiments being done almost all being with polarisation analysis. Two instruments were initially available. One was a conventional instrument albeit with a tilting counter. The other was a primitive polarisation analysis instrument purpose built for diffuse scattering. This latter instrument evolved over more than thirty years and produced results ranging from the separation of magnetic and nuclear diffuse scattering, for which it was conceived, to the isolation of magnetic features in inelastic spectra.

  8. Control of spin-polarised currents in graphene nanorings

    Energy Technology Data Exchange (ETDEWEB)

    Saiz-Bretín, M.; Munárriz, J. [GISC, Departamento de Física de Materiales, Universidad Complutense, E-28040 Madrid (Spain); Malyshev, A.V. [GISC, Departamento de Física de Materiales, Universidad Complutense, E-28040 Madrid (Spain); Ioffe Physical–Technical Institute, St-Petersburg (Russian Federation); Domínguez-Adame, F., E-mail: adame@fis.ucm.es [GISC, Departamento de Física de Materiales, Universidad Complutense, E-28040 Madrid (Spain); Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)

    2015-09-25

    We study electronic transport in systems comprising square graphene nanorings with a ferromagnetic insulator layer on top of them. The rings are connected symmetrically or asymmetrically to contacts. The proximity exchange interaction of electrons with magnetic ions results in spin-dependent transport properties. When a nanoring is connected asymmetrically, the occurrence of Fano-like antiresonances in the transmission coefficient can induce abrupt changes in the spin polarisation under minute variations of the Fermi energy. We also demonstrate that the spin polarisation can be efficiently controlled by a side-gate voltage. This opens a possibility to use these effects for fabricating tunable sources of polarised electrons.

  9. An improved simple polarisable water model for use in biomolecular simulation

    Energy Technology Data Exchange (ETDEWEB)

    Bachmann, Stephan J.; Gunsteren, Wilfred F. van, E-mail: wfvgn@igc.phys.chem.ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland)

    2014-12-14

    The accuracy of biomolecular simulations depends to some degree on the accuracy of the water model used to solvate the biomolecules. Because many biomolecules such as proteins are electrostatically rather inhomogeneous, containing apolar, polar, and charged moieties or side chains, a water model should be able to represent the polarisation response to a local electrostatic field, while being compatible with the force field used to model the biomolecules or protein. The two polarisable water models, COS/G2 and COS/D, that are compatible with the GROMOS biomolecular force fields leave room for improvement. The COS/G2 model has a slightly too large dielectric permittivity and the COS/D model displays a much too slow dynamics. The proposed COS/D2 model has four interaction sites: only one Lennard-Jones interaction site, the oxygen atom, and three permanent charge sites, the two hydrogens, and one massless off-atom site that also serves as charge-on-spring (COS) polarisable site with a damped or sub-linear dependence of the induced dipole on the electric field strength for large values of the latter. These properties make it a cheap and yet realistic water model for biomolecular solvation.

  10. A polarised fast radio burst at low Galactic latitude

    Science.gov (United States)

    Petroff, Emily; SUPERB Collaboration; HESS Collaboration; ANTARES Collaboration

    2017-01-01

    Fast radio bursts (FRBs) are a growing population of transients detected with radio telescopes which are thought to originate outside the Milky Way. Fewer than 20 sources exist in the literature and the majority of bursts have been found away from the plane of the Galaxy or where the Galactic contribution to the total electron column density is low. Here we report on the discovery of a new burst, FRB 150215, discovered with the Parkes radio telescope in real-time in February 2015. The burst was found to be 43±5% linearly polarised with an imprecisely determined rotation measure (RM) consistent with zero. The burst was followed-up with 9 telescopes to search for radio, optical, X-ray, γ-ray and neutrino emission from the location of the burst. No transient or variable emission was found to be associated with the burst and no repeat pulses have been observed in nine hours of Parkes observations. Radio images of the field were obtained following the FRB but would not have been sensitive enough to pick up a signal like the one emanating from WISE J071634.59-190039.2 following FRB150418 if it had been present. The sightline to the burst is close to the Galactic plane and the Galactic RM foreground may approach a null along this sightline, corresponding to a decreased total electron column density from the Milky Way. This might explain why this burst was detectable at low latitude whereas previous searches have been relatively unsuccessful.

  11. Consequences of removing the flattening filter from linear accelerators in generating high dose rate photon beams for clinical applications: A Monte Carlo study verified by measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ishmael Parsai, E. [Department of Radiation Oncology, University of Toledo, 3000 Arlington Avenue, Toledo, OH 43614 (United States)]. E-mail: Ishmael.parsai@utoledo.edu; Pearson, David [Department of Radiation Oncology, University of Toledo, 3000 Arlington Avenue, Toledo, OH 43614 (United States); Department of Physics and Astronomy, University of Toledo, 3000 Arlington Avenue, Toledo, OH 43614 (United States); Kvale, Thomas [Department of Physics and Astronomy, University of Toledo, 3000 Arlington Avenue, Toledo, OH 43614 (United States)

    2007-08-15

    An Elekta SL-25 medical linear accelerator (Elekta Oncology Systems, Crawley, UK) has been modelled using Monte Carlo simulations with the photon flattening filter removed. It is hypothesized that intensity modulated radiation therapy (IMRT) treatments may be carried out after the removal of this component despite it's criticality to standard treatments. Measurements using a scanning water phantom were also performed after the flattening filter had been removed. Both simulated and measured beam profiles showed that dose on the central axis increased, with the Monte Carlo simulations showing an increase by a factor of 2.35 for 6 MV and 4.18 for 10 MV beams. A further consequence of removing the flattening filter was the softening of the photon energy spectrum leading to a steeper reduction in dose at depths greater than the depth of maximum dose. A comparison of the points at the field edge showed that dose was reduced at these points by as much as 5.8% for larger fields. In conclusion, the greater photon fluence is expected to result in shorter treatment times, while the reduction in dose outside of the treatment field is strongly suggestive of more accurate dose delivery to the target.

  12. Investigation of the 1D symmetrical linear graded superconductor-dielectric photonic crystals and its potential applications as an optimized low temperature sensors

    Science.gov (United States)

    Baraket, Zina; Zaghdoudi, Jihene; Kanzari, Mounir

    2017-02-01

    Based on the Transfer Matrix Method (TMM) and the two fluid model for a superconductor and by taking account of the thermal expansion effect and thermo optical effects, we theoretically investigates the transmittance spectra of a one dimensional superconductor -dielectric photonic crystal (PC) designed as ((HLS)5/(SLH)5) made up of a BiGeO12(H), SiO2(L) and YaBO2CuO7 (S). The transmittance spectra shows that the system realizes a tunable filter which depends on a nonlinear relation with temperature. It's found that the symmetrical application of a linear deformation d(m) = d0+(m-1).δd(m) where d0 is the initial thickness of the layer m, δd(m) is the elementary added thickness at each layer. This linear gradation of the thickness permits to improve the temperature sensitivity of the system which acts as an optimized low temperature sensor.

  13. A precise measurement of the $\\tau$ polarisation at LEP-1

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Ajinenko, I; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amapane, N; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Beillière, P; Belokopytov, Yu A; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Bracko, M; Branchini, P; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; 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; Chierici, R; Shlyapnikov, P; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Ferro, F; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerdyukov, L N; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Gris, P; Grosdidier, G; Grzelak, K; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, Sven Olof; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huber, M; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Jeans, D; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Jungermann, L; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kernel, G; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liebig, W; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Maltezos, S; 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; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Myagkov, A; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moraes, D; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Nassiakou, M; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neufeld, N; Nicolaidou, R; Nielsen, B S; Niezurawski, P; Nikolenko, M; Nomokonov, V P; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pavel, T; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Polycarpo, E; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Ripp-Baudot, I; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schwemling, P; Schwering, B; Schwickerath, U; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seibert, N; Sekulin, R L; Shellard, R C; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Squarcia, S; Stanescu, C; Stanic, S; Stanitzki, M; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Tobin, M; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tortosa, P; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Dam, P; Van den Boeck, W; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I B; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zinchenko, A I; Zoller, P; Zucchelli, G C; Zumerle, G

    2001-01-01

    The $\\tau$ polarisation has been studied with the $\\eett$ data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the $\\Z$ resonance firstly through the exclusive decay channels $\\mbox{\\rm e}\

  14. b-quark and quarkonium production and polarisation

    Directory of Open Access Journals (Sweden)

    Kartvelishvili V.

    2013-05-01

    Full Text Available An overview is given of recent measurements of open beauty and heavy quarkonium production and quarkonium polarisation, made by the ATLAS, CMS and LHCb collaborations at the Large Hadron Collider.

  15. Improved LO extraction of the gluon polarisation using COMPASS data

    Energy Technology Data Exchange (ETDEWEB)

    Wilfert, Malte [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz (Germany); Collaboration: COMPASS collaboration

    2015-07-01

    The COMPASS experiment at the M2 beamline of the CERN SPS has taken data with a polarised muon beam (E=160 GeV) scattering of a polarised LiD target from 2002 to 2006. The events in the DIS region are re-analysed to extract simultaneously the gluon polarisation Δg/g and the leading process asymmetry from the same data using a Neural Network approach. The new method of extracting Δg/g is presented. The main feature of this method is a reduction of both the systematic and the statistical uncertainty of the gluon polarisation obtained in LO. The new result is in good agreement with the already published one in PLB 718 (2013) 922 and is presented in three bins of gluon momentum fraction x{sub g}.

  16. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

    CERN Document Server

    Noutsos, A; Kondratiev, V I; Weltevrede, P; Verbiest, J P W; Karastergiou, A; Kramer, M; Kuniyoshi, M; Alexov, A; Breton, R P; Bilous, A V; Cooper, S; Falcke, H; Grießmeier, J -M; Hassall, T E; Hessels, J W T; Keane, E F; Osłowski, S; Pilia, M; Serylak, M; Stappers, B W; ter Veen, S; van Leeuwen, J; Zagkouris, K; Anderson, K; Bähren, L; Bell, M; Broderick, J; Carbone, D; Cendes, Y; Coenen, T; Corbel, S; Eislöffel, J; Fender, R; Garsden, H; Jonker, P; Law, C; Marko, S; Masters, J; Miller-Jones, J; Molenaar, G; Osten, R; Pietka, M; Rol, E; Rowlinson, A; Scheers, B; Spreeuw, H; Staley, T; Stewart, A; Swinbank, J; Wijers, R; Wijnands, R; Wise, M; Zarka, P; van der Horst, A

    2015-01-01

    We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from the propagation of polarised emission in the pulsar magnetosphere and the interstellar medium. The predictions of magnetospheric birefringence in pulsars have been tested using spectra of the pulse width and fractional polarisation from multifrequency data. The derived spectra offer only partial support for the expected effects of birefringence on the polarisation properties, with only about half of our sample being consistent with the model's predictions. It is noted that for some pulsars these measurements are contaminated by the effects of interstellar scattering. For a number of pulsars in our sample, we have observed significant variations in the amount of Faraday rotation as a function of pulse phase, which is possi...

  17. Linear array measurements of enhanced dynamic wedge and treatment planning system (TPS) calculation for 15 MV photon beam and comparison with electronic portal imaging device (EPID) measurements

    Science.gov (United States)

    Petrovic, Borislava; Grzadziel, Aleksandra; Rutonjski, Laza; Slosarek, Krzysztof

    2010-01-01

    Introduction. Enhanced dynamic wedges (EDW) are known to increase drastically the radiation therapy treatment efficiency. This paper has the aim to compare linear array measurements of EDW with the calculations of treatment planning system (TPS) and the electronic portal imaging device (EPID) for 15 MV photon energy. Materials and methods. The range of different field sizes and wedge angles (for 15 MV photon beam) were measured by the linear chamber array CA 24 in Blue water phantom. The measurement conditions were applied to the calculations of the commercial treatment planning system XIO CMS v.4.2.0 using convolution algorithm. EPID measurements were done on EPID-focus distance of 100 cm, and beam parameters being the same as for CA24 measurements. Results Both depth doses and profiles were measured. EDW linear array measurements of profiles to XIO CMS TPS calculation differ around 0.5%. Profiles in non-wedged direction and open field profiles practically do not differ. Percentage depth doses (PDDs) for all EDW measurements show the difference of not more than 0.2%, while the open field PDD is almost the same as EDW PDD. Wedge factors for 60 deg wedge angle were also examined, and the difference is up to 4%. EPID to linear array differs up to 5%. Conclusions The implementation of EDW in radiation therapy treatments provides clinicians with an effective tool for the conformal radiotherapy treatment planning. If modelling of EDW beam in TPS is done correctly, a very good agreement between measurements and calculation is obtained, but EPID cannot be used for reference measurements. PMID:22933916

  18. Linear array measurements of enhanced dynamic wedge and treatment planning system (TPS) calculation for 15 MV photon beam and comparison with electronic portal imaging device (EPID) measurements.

    Science.gov (United States)

    Petrovic, Borislava; Grzadziel, Aleksandra; Rutonjski, Laza; Slosarek, Krzysztof

    2010-09-01

    Enhanced dynamic wedges (EDW) are known to increase drastically the radiation therapy treatment efficiency. This paper has the aim to compare linear array measurements of EDW with the calculations of treatment planning system (TPS) and the electronic portal imaging device (EPID) for 15 MV photon energy. The range of different field sizes and wedge angles (for 15 MV photon beam) were measured by the linear chamber array CA 24 in Blue water phantom. The measurement conditions were applied to the calculations of the commercial treatment planning system XIO CMS v.4.2.0 using convolution algorithm. EPID measurements were done on EPID-focus distance of 100 cm, and beam parameters being the same as for CA24 measurements. Both depth doses and profiles were measured. EDW linear array measurements of profiles to XIO CMS TPS calculation differ around 0.5%. Profiles in non-wedged direction and open field profiles practically do not differ. Percentage depth doses (PDDs) for all EDW measurements show the difference of not more than 0.2%, while the open field PDD is almost the same as EDW PDD. Wedge factors for 60 deg wedge angle were also examined, and the difference is up to 4%. EPID to linear array differs up to 5%. The implementation of EDW in radiation therapy treatments provides clinicians with an effective tool for the conformal radiotherapy treatment planning. If modelling of EDW beam in TPS is done correctly, a very good agreement between measurements and calculation is obtained, but EPID cannot be used for reference measurements.

  19. Measurement of the Tau Lepton Polarisation at LEP2

    CERN Document Server

    Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, P; Ballestrero, A; Bambade, P; Barbier, R; Bardin, D; Barker, G J; Baroncelli, A; Battaglia, M; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N; Benvenuti, A; Bérat, C; Berggren, M; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Buschbeck, B; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F; Chapkin, M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Da Silva, T; Da Silva, W; Dedovich, D; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J; Gandelman, M; García, C; Gavillet, P; Gazis, E; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E; Kernel, G; Kersevan, B P; Kerzel, U; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L; Murray, W; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Navarria, F; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevski, A; Onofre, A; Orava, R; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Pozdnyakov, V; Pukhaeva, N; Pullia, A; Rames, J; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Sander, C; Savoy-Navarro, A; Schwickerath, U; Sekulin, R; Siebel, M; Sisakian, A; Smadja, G; Smirnova, O; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Tegenfeldt, F; Timmermans, J; Tkatchev, L; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M

    2008-01-01

    A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.

  20. Measurement of the Tau Lepton Polarisation at LEP2

    CERN Document Server

    Abdallah, J.; Adam, W.; Adzic, P.; Albrecht, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P.P.; Amaldi, U.; Amapane, N.; Amato, Sandra F.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, Pierre; Apel, W-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, Jean-Eudes; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.J.; Baroncelli, Antonio; Battaglia, M.; Baubillier, M.; Becks, K-H.; Begalli, M.; Behrmann, A.; Ben-Haim, Eli; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, Mikael; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, Michal; Bonesini, Maurizio; Boonekamp, M.; Booth, P.S.L.; Borisov, G.; Botner, Olga; Bouquet, B.; Bowcock, T.J.V.; Boyko, I.; Bracko, Marko; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J.M.; Buschbeck, B.; Buschmann, P.; Calvi, M.; Camporesi, Tiziano; Canale, V.; Carena, F.; Castro, Nuno Filipe; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, Paolo; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, Suh-Urk; Cieslik, K.; Collins, P.; Contri, Roberto; Cosme, G.; Cossutti, Fabio; Costa, M.J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; da Silva, T.; Da Silva, W.; Dedovich, D.; Della Ricca, Giuseppe; De Angelis, Alessandro; De Boer, W.; De Clercq, C.; De Lotto, Barbara; De Maria, N.; De Min, A.; de Paula, L.; Di Ciaccio, L.; Di Simone, A.; Doroba, K.; Eigen, G.; Ekelof, Tord; Ellert, Mattias; Elsing, M.; Espirito Santo, Maria Catarina; Fanourakis, George K.; Feindt, Michael; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, Miriam; Garcia, C.; Gavillet, Philippe; Gazis, Evangelos; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, Klaus; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, Vincent; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S-O.; Holt, P.J.; Houlden, M.A.; Jackson, John Neil; Jarlskog, Goran; Jarry, P.; Jeans, D.; Johansson, E.K.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, Frederic; Katsanevas, S.; Katsoufis, E.; Kernel, Gabrijel; Kerzel, U.; King, B.T.; Kjaer, N.J.; Kluit, Peter; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, Jacques; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J.H.; Lopez, J.M.; Loukas, D.; Lutz, Pierre; Lyons, Louis; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J-C.; Mariotti, C.; Markou, Athanasios; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, Francisco; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; Nulty, R.Mc; Meroni, C.; Migliore, E.; Mitaroff, Winfried A.; Mjoernmark, U.; Moa, T.; Moch, M.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim Filho, Luiz Martins; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J.P.; Palka, Henryk; Papadopoulou, Th.D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, Andrea; Petrolini, Alessandro; Piedra, Jonatan; Pieri, L.; Pierre, Francois; Pimenta, M.; Piotto, E.; Poireau, V.; Pol, M.E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, Peter; Richard, F.; Ridky, Jan; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann, Vanina; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, Martin; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli de Fatis, T.; Taffard, A.C.; Tegenfeldt, F.; Timmermans, Jan; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, Petr; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, Clara; Turluer, M-L.; Tyapkin, I.A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, Giovanni; Van Dam, P.; Van Eldik, J.; van Remortel, N.; Van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, Patrice; Verzi, V.; Vilanova, D.; Vitale, Lorenzo; Vrba, V.; Wahlen, H.; Washbrook, A.J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, Danilo; Zhuravlov, V.; Zimine, N.I.; Zintchenko, Alexandre

    2008-01-01

    A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.

  1. Macrophage polarisation: immune responses of carp against parasites

    OpenAIRE

    Joerink, M.

    2006-01-01

    In the studies described in this thesis we used a natural host-parasite model of two parasites ( Trypanoplasma borreli and Trypanosoma carassii ) infecting common carp ( Cyprinus carpio L.), to obtain more knowledge about the phenomenon of macrophage polarisation in 'the evolutionary older' teleosts and the consequences of differential activation for the individual host.The general aspects of the teleost immune system are very similar to those of the mammalian immune system. Polarisation of m...

  2. Reducing the Solar Neutrino Background Using Polarised Helium-3

    CERN Document Server

    Franarin, Tarso

    2016-01-01

    Future dark matter detectors plan to have sensitivities such that solar neutrinos will start to become a problematic background. In this work we show that a polarised helium-3 detector would in principle be able to eliminate 98% of these events when the orientation of the polarisation axis is antiparallel to the direction of the Sun. We comment on the possible improvement in sensitivity of dark matter direct detection experiments due to this effect and the feasibility of building such a detector.

  3. Polarisers in the focal domain: Theoretical model and experimental validation

    Science.gov (United States)

    Martínez-Herrero, Rosario; Maluenda, David; Juvells, Ignasi; Carnicer, Artur

    2017-02-01

    Polarisers are one of the most widely used devices in optical set-ups. They are commonly used with paraxial beams that propagate in the normal direction of the polariser plane. Nevertheless, the conventional projection character of these devices may change when the beam impinges a polariser with a certain angle of incidence. This effect is more noticeable if polarisers are used in optical systems with a high numerical aperture, because multiple angles of incidence have to be taken into account. Moreover, the non-transverse character of highly focused beams makes the problem more complex and strictly speaking, the Malus’ law does not apply. In this paper we develop a theoretical framework to explain how ideal polarisers affect the behavior of highly focused fields. In this model, the polarisers are considered as birefringent plates, and the vector behaviour of focused fields is described using the plane-wave angular spectrum approach. Experiments involving focused fields were conducted to verify the theoretical model and a satisfactory agreement between theoretical and experimental results was found.

  4. Optically induced dynamic nuclear spin polarisation in diamond

    Science.gov (United States)

    Scheuer, Jochen; Schwartz, Ilai; Chen, Qiong; Schulze-Sünninghausen, David; Carl, Patrick; Höfer, Peter; Retzker, Alexander; Sumiya, Hitoshi; Isoya, Junichi; Luy, Burkhard; Plenio, Martin B.; Naydenov, Boris; Jelezko, Fedor

    2016-01-01

    The sensitivity of magnetic resonance imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz et al 2011 Neoplasia 13 81). Nuclear spins associated with the 13C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt and High 2011 Prog. Nucl. Magn. Reson. Spectrosc. 38 37). If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a nitrogen-vacancy centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis.

  5. Measurement of the SMC muon beam polarisation using the asymmetry in the elastic scattering off polarised electrons

    CERN Document Server

    Adams, D; Akdogan, T; Arik, E; Arvidson, A; Badelek, B; Bardin, G; Baum, G; Berglund, P; Betev, L; Birsa, R; Björkholm, P; Bonner, B E; De Botton, N R; Boutemeur, M; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Cavata, C; Clocchiatti, M; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Dyring, A; Eichblatt, S; Faivre, Jean-Claude; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gatignon, L; Gaussiran, T; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Golutvin, I A; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; 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; Kessler, H J; Ketel, T; Kiryluk, J; Kiryushin, Yu T; Kishi, A; Kiselev, Yu F; Klostermann, L; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kukhtin, V V; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Lindqvist, T; Litmaath, M; Loewe, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nagaitsev, A P; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Piegaia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Pussieux, T; Rädel, G; Rijllart, A; Reicherz, G; Roberts, J B; Rock, S E; Rodríguez, M; Rondio, Ewa; Ropelewski, Leszek; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Schüler, K P; Seitz, R; Semertzidis, Y K; Sergeev, S; Shanahan, P; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K; Zamiatin, N I; Zhao, J

    2000-01-01

    A muon beam polarimeter was built for the SMC experiment at the CERN SPS, for beam energies of 100 and 190~GeV. The beam polarisation is determined from the asymmetry in the elastic scattering off the polarised electrons of a ferromagnetic target whose magnetisation is periodically reversed. At muon energies of 100 and 190~GeV the measured polarisation is $P_{\\mu}=-0.80 \\pm 0.03 (stat.)\\pm 0.02 (syst.)$ and $P_{\\mu}=-0.797 \\pm 0.011 (stat.)\\pm 0.012 (syst.)$, respectively. These results agree with measurements of the beam polarisation using a shape analysis of the decay positron energy spectrum.

  6. Polarised Black Holes in AdS

    CERN Document Server

    Costa, Miguel S.; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-01-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...

  7. Polarised black holes in AdS

    Science.gov (United States)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  8. Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photon beams from a linear accelerator and cyber-knife.

    Science.gov (United States)

    Arakia, Fujio; Moribe, Nobuyuki; Shimonobou, Toshiaki; Yamashita, Yasuyuki

    2004-07-01

    A fully automatic radiophotoluminescent glass rod dosimeter (GRD) system has recently become commercially available. This article discusses the dosimetric properties of the GRD including uniformity and reproducibility of signal, dose linearity, and energy and directional dependence in high-energy photon beams. In addition, energy response is measured in electron beams. The uniformity and reproducibility of the signal from 50 GRDs using a 60Co beam are both +/- 1.1% (one standard deviation). Good dose linearity of the GRD is maintained for doses ranging from 0.5 to 30 Gy, the lower and upper limits of this study, respectively. The GRD response is found to show little energy dependence in photon energies of a 60Co beam, 4 MV (TPR20(10)=0.617) and 10 MV (TPR(20)10=0.744) x-ray beams. However, the GRD responses for 9 MeV (mean energy, Ez = 3.6 MeV) and 16 MeV (Ez = 10.4 MeV) electron beams are 4%-5% lower than that for a 60Co beam in the beam quality dependence. The measured angular dependence of GRD, ranging from 0 degrees (along the long axis of GRD) to 120 degrees is within 1.5% for a 4 MV x-ray beam. As applications, a linear accelerator-based radiosurgery system and Cyber-Knife output factors are measured by a GRD and compared with those from various detectors including a p-type silicon diode detector, a diamond detector, and an ion chamber. It is found that the GRD is a very useful detector for small field dosimetry, in particular, below 10 mm circular fields.

  9. Precision tracking and electromagnetic calorimetry towards a measurement of the pion polarisabilities at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Dinkelbach, Anna-Maria Elisabeth

    2010-07-20

    In 2004 the COMPASS experiment at CERN SPS measured soft reactions with a beam of negatively charged pions on various nuclear targets. For this measurement, a silicon micro-strip telescope was installed in the target region. For the first time 5 silicon detector stations were operated simultaneously in the COMPASS experiment. A novel method of time calibration, with a clustering algorithm accordingly adapted, and refined alignment corrections were implemented in the analysis software. The spatial resolution of a silicon detector was determined to be 5 - 14 {mu}m and the time resolution 2 - 3 ns. Combining the time information of all stations, a track time resolution of 530 ps from the silicon telescope could be reached. One of the key points of this experiment was the observation of Primakoff events, namely pions scattering off quasi-real photons in the Coulomb field of a heavy nucleus. The production of real photons corresponds to pion Compton scattering in inverse kinematics which is sensitive to the pion polarisabilities {alpha}{sub {pi}} and {beta}{sub {pi}}. Key ingredient for such measurements is a precise knowledge of the performance of the electromagnetic calorimeter. This includes a study of the instabilities of calorimeter cells and an improved reconstruction algorithm. A data-driven shower model was developed, which was used for a timedependent recalibration of the calorimeter. A new cluster refitting method was used to recover position and energy of clusters containing passive or saturated cells and detects double-hit clusters. The latter are important, as the main background to the Primakoff Compton events stems from neutral pions misinterpreted as single-photon hits. The physics analysis comprised the selection of Primakoff events and the necessary steps to obtain the pionic polarisabilities. The measurement was limited by systematic effects of the apparatus also determined within this thesis. (orig.)

  10. Medium-Term Stability of the Photon Beam Energy of An Elekta CompactTM Linear Accelerator Based on Daily Measurements of Beam Quality Factor

    Directory of Open Access Journals (Sweden)

    Mohammad Amin Mosleh-Shirazi

    2016-04-01

    Full Text Available Introduction In this study, we aimed to assess the medium-term energy stability of a 6MV Elekta CompactTM linear accelerator. To the best of our knowledge, this is the first published article to evaluate this linear accelerator in terms of energy stability. As well as investigating the stability of the linear accelerator energy over a period of several weeks, the results will be useful for estimation of the required tolerance values for the beam quality factor (BQF of the PTW QUICKCHECK weblineTM (QCW daily checking device. Materials and Methods Over a 13 week period of routine clinical service, 52 daily readings of BQF were taken and then analyzed for a 10×10 cm2 field. Results No decreasing or increasing trend in BQF was observed over the study period. The mean BQF value was estimated at 5.4483 with a standard deviation (SD of 0.0459 (0.8%. The mean value was only 0.1% different from the baseline value. Conclusion The results of this medium-term stability study of the Elekta Compact linear accelerator energy showed that 96.2% of the observed BQF values were within ±1.3% of the baseline value. This can be considered to be within the recommended tolerance for linear accelerator photon beam energy. If an approach of applying ±3 SD is taken, the tolerance level for BQF may be suggested to be set at ±2.5%. However, further research is required to establish a relationship between BQF value and the actual changes in beam energy and penetrative quality.

  11. Rapid Identification and Quantification of Linear Olefin Isomers by Online Ozonolysis-Single Photon Ionization Time-of-Flight Mass Spectrometry.

    Science.gov (United States)

    Xie, Yuanyuan; Chen, Ping; Hua, Lei; Hou, Keyong; Wang, Yongchao; Wang, Haiyan; Li, Haiyang

    2016-01-01

    The specific locations of the double bonds in linear olefins can facilitate olefin catalytic synthetic reactions to improve the quality of target olefin products. We developed a simple and efficient approach based on single photon ionization time-of-flight mass spectrometry (SPI-TOFMS) combined with online ozonolysis to identify and quantify the linear olefin double bond positional isomers. The online ozonolysis cleaved the olefins at the double bond positions that led to formation of corresponding characteristic aldehydes. The aldehydes were then detected by SPI-TOFMS to achieve unique spectrometric "fingerprints" for each linear olefin to successfully identify the isomeric ones. To accurately quantify the isomeric components in olefin mixtures, an algorithm was proposed to quantify three isomeric olefin mixtures based on characteristic ion intensities and their equivalent ionization coefficients. The relative concentration errors for the olefin components were lower than 2.5% while the total analysis time was less than 2 min. These results demonstrate that the online ozonolysis SPI-TOFMS has the potential for real-time monitoring of catalytic olefin synthetic reactions.

  12. Polarisation analysis of VUV synchrotron radiation emitted from a bending magnet source in the energy range 20-50 eV: A comparison between measurements and theoretical predictions

    Energy Technology Data Exchange (ETDEWEB)

    Finetti, P.; Holland, D.M.P. E-mail: d.m.p.holland@dl.ac.uk; Latimer, C.J.; Binns, C

    2004-02-01

    The results of a study to characterise the polarisation properties of the photon beam emerging from beamline 5D, mounted on a bending magnet source at the Synchrotron Radiation Source, Daresbury Laboratory, are presented. The expectation values for the Stokes parameters corresponding to the light transmitted by the beamline have been calculated by combining ray-tracing and optical methods. The polarisation of the light at the source is modified both by the beamline geometry and by the reflections at the optical components. Although it is often assumed that the polarising properties of grazing incidence optics are negligible, this assumption leads to rather inaccurate results in the VUV region. A study of the reflectivity shows that even at incidence angles ({theta}{sub i}=80-85 deg.) which are far from the Brewster angle ({theta}{sub B}{approx}45 deg. for VUV and soft X-ray radiation) the residual changes in the amplitudes of the reflected light can result in non-negligible polarisation effects. Furthermore, reflection at grazing incidence gives rise to a substantial change in the phase, and this has the effect of rotating the elliptically polarised state. Theoretical Stokes parameters have been compared with full polarisation measurements obtained using a reflection polarimeter in the energy range 20-40 eV.

  13. CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation.

    Science.gov (United States)

    Hahn, C; Weber, G; Märtin, R; Höfer, S; Kämpfer, T; Stöhlker, Th

    2016-04-01

    Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays - such as laser-generated plasmas - is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.

  14. Measurements of photon and neutron leakage from medical linear accelerators and Monte Carlo simulation of tenth value layers of concrete used for intensity modulated radiation therapy treatment

    Science.gov (United States)

    Jaradat, Adnan Khalaf

    The x ray leakage from the housing of a therapy x ray source is regulated to be bubble detector of type BD-PND and using Track-Etch detectors. The highest neutron dose equivalent per unit electron dose was at 0° for all electron energies. The neutron leakage from photon beams was the highest between all the machines. Intensity modulated radiation therapy (IMRT) delivery consists of a summation of small beamlets having different weights that make up each field. A linear accelerator room designed exclusively for IMRT use would require different, probably lower, tenth value layers (TVL) for determining the required wall thicknesses for the primary barriers. The first, second, and third TVL of 60Co gamma rays and photons from 4, 6, 10, 15, and 18 MV x ray beams by concrete have been determined and modeled using a Monte Carlo technique (MCNP version 4C2) for cone beams of half-opening angles of 0°, 3°, 6°, 9°, 12°, and 14°.

  15. CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, C., E-mail: christoph.hahn@uni-jena.de; Höfer, S.; Kämpfer, T. [Helmholtz Institute Jena, 07743 Jena (Germany); Institute of Optics and Quantum Electronics, University of Jena, 07743 Jena (Germany); Weber, G.; Märtin, R. [Helmholtz Institute Jena, 07743 Jena (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Stöhlker, Th. [Helmholtz Institute Jena, 07743 Jena (Germany); Institute of Optics and Quantum Electronics, University of Jena, 07743 Jena (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2016-04-15

    Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays — such as laser-generated plasmas — is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.

  16. Far-infrared polarisation of the quasar 3C 279

    CERN Document Server

    Klaas, U; Clavel, J; Klaas, Ulrich; Laureijs, Rene J.; Clavel, Jean

    1999-01-01

    We present the first FIR polarisation results of the OVV quasar 3C 279 obtained with ISOPHOT for two epochs in 1996 and 1997. We describe its integral polarisation properties at a wavelength of 170 micron where the source shows a maximum in its energy distribution. After a gamma-ray flare in January 1996, a polarisation of 23 % closely aligned with the radio jet axis was measured in July 1996. In June 1997, the polarisation degree had decreased to 6.5 % with a less good alignment. On the other hand, the total 170 micron flux is the same for both epochs. Our measurements provide additional constraints for the multi-wavelength properties of synchrotron emission in radio jets and the temporal evolution of these properties: they show that the FIR radiation of 3C 279 is optically thin and that its origin is very close to the core. The variability of the FIR polarisation without any change of the total FIR flux can be explained by a disordering of the magnetic field in between the core and the first stationary VLBI...

  17. Optical Effects Accompanying the Dynamical Bragg Diffraction in Linear 1D Photonic Crystals Based on Porous Silicon

    Directory of Open Access Journals (Sweden)

    Anton Maydykovskiy

    2014-10-01

    Full Text Available We survey our recent results on the observation and studies of the effects accompanying the dynamical Bragg diffraction in one-dimensional photonic crystals (PhC. Contrary to the kinematic Bragg diffraction, the dynamical one considers a continuous interaction between the waves travelling within a spatially-periodic structure and is the most pronounced in the so called Laue geometry, leading to a number of exciting phenomena. In the described experiments, we study the PhC based on porous silicon or porous quartz, made by the electrochemical etching of crystalline silicon with the consequent thermal annealing. Importantly, these PhC are approximately hundreds of microns thick and contain a few hundreds of periods, so that the experiments in the Laue diffraction scheme are available. We discuss the effect of the temporal splitting of femtosecond laser pulses and show that the effect is quite sensitive to the polarization and the phase of a femtosecond laser pulse. We also show the experimental realization of the Pendular effect in porous quartz PhC and demonstrate the experimental conditions for the total spatial switching of the output radiation between the transmitted and diffracted directions. All described effects are of high interest for the control over the light propagation based on PhC structures.

  18. Measurement of single-spin azimuthal asymmetries in semi-inclusive electroproduction of pions and kaons on a longitudinally polarised deuterium target

    OpenAIRE

    Airapetian, A.; Akopov, N.; Akopov, Z.; Amarian, M; Ammosov, V. V.; Andrus, A.; Aschenauer, E. C.; Augustyniak, W.; Avakian, H.; Avakian, R.; Avetissian, A.; Avetissian, E.; Bailey, P.; Baturin, V.; Baumgarten, C.

    2003-01-01

    Single-spin asymmetries have been measured for semi-inclusive electroproduction of $\\pi^+$, $\\pi^-$, $\\pi^0$ and $K^+$ mesons in deep-inelastic scattering off a longitudinally polarised deuterium target. The asymmetries appear in the distribution of the hadrons in the azimuthal angle $\\phi$ around the virtual photon direction, relative to the lepton scattering plane. The corresponding analysing powers in the $\\sin \\phi$ moment of the cross section are $0.012 \\pm 0.002 {(stat.)} \\pm 0.002 {(sy...

  19. First measurement of the polarisation asymmetry of a gamma-ray beam between 1.7 to 74 MeV with the HARPO TPC

    Science.gov (United States)

    Gros, P.; Amano, S.; Attié, D.; Bernard, D.; Bruel, P.; Calvet, D.; Colas, P.; Daté, S.; Delbart, A.; Frotin, M.; Geerebaert, Y.; Giebels, B.; Götz, D.; Hashimoto, S.; Horan, D.; Kotaka, T.; Louzir, Marc; Minamiyama, Y.; Miyamoto, S.; Ohkuma, H.; Poilleux, Patrick; Semeniouk, I.; Sizun, P.; Takemoto, A.; Yamaguchi, M.; Wang, S.

    2016-07-01

    Current γ-ray telescopes suffer from a gap in sensitivity in the energy range between 100 keV and 100 MeV, and no polarisation measurement has ever been done on cosmic sources above 1 MeV. Past and present e+e- pair telescopes are limited at lower energies by the multiple scattering of electrons in passive tungsten converter plates. This results in low angular resolution, and, consequently, a drop in sensitivity to point sources below 1 GeV. The polarisation information, which is carried by the azimuthal angle of the conversion plane, is lost for the same reasons. HARPO is an R&D program to characterise the operation of a gaseous detector (a Time Projection Chamber or TPC) as a high angular-resolution and sensitivity telescope and polarimeter for γ-rays from cosmic sources. It represents a first step towards a future space instrument in the MeV-GeV range. We built and characterised a 30cm cubic demonstrator [SPIE 91441M], and put it in a polarised γ-ray beam at the NewSUBARU accelerator in Japan. Data were taken at photon energies from 1.74MeV to 74MeV and with different polarisation configurations. We describe the experimental setup in beam. We then describe the software we developed to reconstruct the photon conversion events, with special focus on low energies. We also describe the thorough simulation of the detector used to compare results. Finally we will present the performance of the detector as extracted from this analysis and preliminary measurements of the polarisation asymmetry. This beam-test qualification of a gas TPC prototype in a γ-ray beam could open the way to high-performance -ray astronomy and polarimetry in the MeV-GeV energy range in the near future.

  20. Tight focusing of femtosecond elliptically polarised vortex light pulses

    Institute of Scientific and Technical Information of China (English)

    Hua Li-Min; Chen Bao-Suan; Chen Zi-Yang; Pu Ji-Xiong

    2011-01-01

    This paper studies the tight focusing properties of femtosecond elliptically polarised vortex light pulses. Based on Richards-Wolf vectorial diffraction integral, the expressions for the electric field, the velocity of the femtosecond light pulse and the total angular momentum of focused pluses are derived. The numerical calculations are also given to illustrate the intensity distribution, phase contour, the group velocity variation and the total angular momentum near the focus. It finds that near the focus the femtosecond elliptically polarised vortex light pulse can travel at various group speeds, that is, slower or faster than light speed in vacuum, depending on the numerical aperture of the focusing objective system. Moreover, it also studies the influence of the numerical aperture of the focusing objective and the time duration of the elliptically polarised vortex light pulse on the total angular momentum distribution in the focused field.

  1. A Initio Studies of Polarisabilities of Ions in Crystals.

    Science.gov (United States)

    Tole, Philip

    Available from UMI in association with The British Library. This thesis is concerned with the ab initio calculation of polarisabilities of ions in crystals. For a binary salt the Clausius-Mossotti equation relates the refractive index to the in-crystal polarisability of the ion-pair. However, there is no experimental means of separating the sum into anion and cation components. Theoretical models which use isolated ion polarisabilities to do this are physically unrealistic and have met with little success. A much better model has been developed using ab initio all-electron CHF calculations. The in-crystal environment is represented by a 'molecular' cluster embedded in a point-charge lattice. The physical features important to the success of the model are the nearest-neighbour overlap compression and the isotropic part of the electrostatic potential arising from the point -charge lattice. Calculations on simple first row alkali halides show the cation to be independent of these forces whereas the anion becomes, smaller, more bound and less polarisable in the crystal. When corrections for correlation are added the agreement with Clausius-Mossotti polarisabilities is at the 5% level or better. This implies a reduction in polarisability by factors of up to 2 with respect to the free ion. The polarisabilities for the anions in LiF, NaF, KF, LiCl, NaCl, KCl, LiBr, NaBr, KBr, CaF _2, BeO, MgO, CaO, Li_2O, Na_2O, K_2O, BeS, CaS, Li_2S, Na_2 S and K_2S were calculated. Anion polarisability is found to vary with lattice parameter but hardly at all with coordination number. Calculations on Be_2C show that in-crystal compression is sufficient to stabilise even C^{4 -}, which has a polarisability of over 20 au. Anions at the surface of LiF and MgO were also modelled. Because anisotropic overlap and electrostatic factors tend to cancel, the ion in 5-, 4- and 3-coordinate surface sites has a polarisability only a few per cent greater than in the bulk solid. Implications for

  2. Polarisation of microwave emission from reconnecting twisted coronal loops

    CERN Document Server

    Gordovskyy, Mykola; Kontar, Eduard

    2016-01-01

    Magnetic reconnection and particle acceleration due to the kink instability in twisted coronal loops can be a viable scenario for confined solar flares. Detailed investigation of this phenomenon requires reliable methods for observational detection of magnetic twist in solar flares, which may not be possible solely through extreme UV and soft X-ray thermal emission. The gradient of microwave polarisation across flaring loops can serve as one of the detection criteria. The aim of this study is to investigate the effect of magnetic twist in flaring coronal loops on the polarisation of gyro-synchrotron microwave emission, and determine whether microwave emission polarisation could provide a means for observational detection. We use time-dependent magnetohydrodynamic and test-particle models, developed using LARE3D and GCA codes to investigate twisted coronal loops relaxing following the kink-instability, and calculate synthetic microwave emission maps (I and V Stokes components) using GX simulator. It is found t...

  3. Extracting cosmic microwave background polarisation from satellite astrophysical maps

    CERN Document Server

    Baccigalupi, C; De Zotti, G; Smoot, G F; Burigana, C; Maino, D; Bedini, L; Salerno, E

    2002-01-01

    We present the application of the Fast Independent Component Analysis technique for blind component separation to polarised astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarised signal, consisting of $E$ and $B$ modes, can be extracted from maps affected by substantial contamination from diffuse Galactic foregrounds and instrumental noise. We perform the analysis of all sky maps simulated accordingly to the nominal performances of the Low Frequency Instrument (LFI) aboard the Planck satellite; the sky signal is modeled as a superposition of CMB, generated by a Gaussian, nearly scale invariant cosmological perturbation spectrum, and the existing simulated polarisation templates of Galactic synchrotron. Our results indicate that the angular power spectrum of CMB $E$ modes can be recovered on all scales up to $\\ell\\simeq 1000$, corresponding to the fourth acoustic oscillation, while $B$ modes can be detected, up to their turnover at $\\ell\\simeq 100$ if cosmological tensor amplitude...

  4. Model-independent measurement of the top quark polarisation

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Saavedra, J.A., E-mail: jaas@ugr.es [Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Herrero-Hahn, R.V. [Departamento de Fisica Aplicada, Universidad de Granada, Granada (Spain)

    2013-01-08

    We introduce a new asymmetry in the decay t{yields}Wb{yields} Script-Small-L {nu}b, which is shown to be directly proportional to the polarisation of the top quark along a chosen axis, times a sum of W helicity fractions. The latter have already been precisely measured at the Tevatron and the Large Hadron Collider. Therefore, this new asymmetry can be used to obtain a model-independent measurement of the polarisation of top quarks produced in any process at hadron or lepton colliders.

  5. The Gender Dimension of Technical Change and Job Polarisation

    OpenAIRE

    Joanne Lindley

    2010-01-01

    Many studies have shown that technical change has led to job polarisation. A relatively unexplored aspect of this is whether there has been a gender bias. This paper is the first to show gender bias in technology driven skill polarisation. Between 1997 and 2006 the demand for women shows hollowing out across high, medium and low education groups, as a consequence of technical change. This was not the case for men. Decomposing the fall in the gender pay gap shows further evidence for gender bi...

  6. Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

    Science.gov (United States)

    Bulla, Mattia

    2017-02-01

    Despite their relevance across a broad range of astrophysical research topics, Type Ia supernova explosions are still poorly understood and answers to the questions of when, why and how these events are triggered remain unclear. In this respect, polarisation offers a unique opportunity to discriminate between the variety of possible scenarios. The observational evidence that Type Ia supernovae are associated with rather low polarisation signals (smaller than a few per cent) places strong constraints for models and calls for modest asphericities in the progenitor system and/or explosion mechanism.The goal of this thesis is to assess the validity of contemporary Type Ia supernova explosion models by testing whether their predicted polarisation signatures can account for the small signals usually observed. To this end, we have implemented and tested an innovative Monte Carlo scheme in the radiative transfer code artis. Compared to previous Monte Carlo approaches, this technique produces synthetic observables (light curves, flux and polarisation spectra) with a substantial reduction in the Monte Carlo noise and therefore in the required computing time. This improvement is particularly crucial for our study as we aim to extract very weak polarisation signals, comparable to those detected in Type Ia supernovae. We have also demonstrated the applicability of this method to other classes of supernovae via a preliminary study of the first spectropolarimetry observations of superluminous supernovae.Using this scheme, we have calculated synthetic spectropolarimetry for three multi-dimensional explosion models recently proposed as promising candidates to explain Type Ia supernovae. Our findings highlight the power of spectropolarimetry in testing and discriminating between different scenarios. While all the three models predict light curves and flux spectra that are similar to each others and reproduce those observed in Type Ia supernovae comparably well, polarisation does

  7. The polariser beamline at TRIUMF for nuclear structure physics

    Science.gov (United States)

    Voss, A.; Pearson, M. R.; Levy, C. D. P.; Billowes, J.; Buchinger, F.; Chow, K. H.; Crawford, J. E.; Hossein, M. D.; Kiefl, R. F.; Macfarlane, W. A.; Mané, E.; Morris, G. D.; Parolin, T. J.; Saadaoui, H.; Salman, Z.; Shelbaya, O. T. J.; Smadella, M.; Song, Q.; Wang, D.

    2011-10-01

    Originally built to provide polarised ion beams for condensed matter experiments, the polariser beamline at TRIUMF is coupled to both beta-NMR and beta-NQR spectrometers. In addition, the beam can be passed through a radio-frequency quadrupole cooler and buncher (RFQ) providing bunched beams. Recently, a laser spectroscopy and beta-NQR program was started to investigate the ground state structure of exotic nuclei. Results from recent experiments including zero-field beta-NQR studies to determine the quadrupole moment of the halo nucleus Li-11 and laser spectroscopy to determine the charge radius of Rb-74.

  8. Theoretical study of second-order non-linear optical properties of pyrromethene dyes for photonic application

    Energy Technology Data Exchange (ETDEWEB)

    Acebal, P; Blaya, S; Carretero, L [Departamento de Ciencia y Tecnologia de Materiales, Universidad Miguel Hernandez, Avenida Ferrocarril s/n, Apartado 032002, Edificio Torrevaillo, Elx (Alicante) (Spain)

    2003-06-28

    Second-order non-linear optical properties and the ground state dipole moment of 2-, 6-, and 8-substituted dipyrromethene-BF{sub 2} complexes were evaluated using ab initio quantum mechanical methods and compared with those of a standard push-pull chromophore. The theoretical values obtained are discussed in terms of the different contributions of each spatial region using the electron density derivatives with respect to an applied electric field. As results, an origin for the second hyperpolarizability and a methodology for improving the performance of these compounds are proposed. The two-level model has been use to study the electro-optic properties of the substituted dipyrromethene-BF{sub 2} complexes, and the applicability of this method has been discussed in terms of the electron density derivatives.

  9. Inclusion of W^+- single-spin asymmetry data in a polarised PDF determination via Bayesian reweighting

    CERN Document Server

    Nocera, Emanuele R

    2013-01-01

    We discuss how the experimental information from longitudinal single-spin asymmetries for $W^{\\pm}$ boson production in polarised proton-proton collisions can be included in a polarised parton determination by Bayesian reweighting of a Monte Carlo set of polarised PDF replicas. We explicitly construct a prior ensemble of polarised parton distributions using available fits to inclusive and semi-inclusive DIS data and we discuss the potential impact of existing and future RHIC measurements on it.

  10. Optical diode based on the chirality of guided photons

    CERN Document Server

    Sayrin, C; Mitsch, R; Albrecht, B; O'Shea, D; Schneeweiss, P; Volz, J; Rauschenbeutel, A

    2015-01-01

    Photons are nonchiral particles: their handedness can be both left and right. However, when light is transversely confined, it can locally exhibit a transverse spin whose orientation is fixed by the propagation direction of the photons. Confined photons thus have chiral character. Here, we employ this to demonstrate nonreciprocal transmission of light at the single-photon level through a silica nanofibre in two experimental schemes. We either use an ensemble of spin-polarised atoms that is weakly coupled to the nanofibre-guided mode or a single spin-polarised atom strongly coupled to the nanofibre via a whispering-gallery-mode resonator. We simultaneously achieve high optical isolation and high forward transmission. Both are controlled by the internal atomic state. The resulting optical diode is the first example of a new class of nonreciprocal nanophotonic devices which exploit the chirality of confined photons and which are, in principle, suitable for quantum information processing and future quantum optica...

  11. Polarisation independent bi-directional four wave mixing for mid span spectral inversion

    DEFF Research Database (Denmark)

    Clausen, Anders; Buxens, Alvaro A.; Poulsen, Henrik Nørskov

    1999-01-01

    Polarisation independent Four Wave Mixing in a Semiconductor Optical Amplifier used for Mid Span Spectral Inversion (MSSI) is implemented and introduce only 0.9 dB penalty compared to polarisation dependent MSSI. The polarisation dependence in receiver sensitivity is 1 dB....

  12. Measurement of the Vector and Tensor Polarisation of Proton and Deuteron Beams

    CERN Document Server

    Lesiak, M; Budzanowski, A; Chatterjee, A; Ernst, J; Gebel, R; Hawranek, P; Jahn, R; Jha, V; Kilian, K; Kliczewski, S; Kirillov, Da; Kirillov, Di; Kolev, D; Kravcikova, M; Kutsarova, T; Lieb, J; Machner, H; Magiera, A; Maier, R; Martinská, G; Nedev, S; Piskunov, N; Prasuhn, D; Protic, D; Rossen, P; Roy, B J; Sitnik, I; Siudak, R; Tsenov, R V; Ulicny, M; Urbán, J; Vankova, G; Wilkin, C

    2005-01-01

    Measurement of the d + d -> 4He + eta reaction using vector and tensor polarised beam has been performed at COSY using Big Karl magnetic spectrograph. The beam polarisation necessary for obtaining the vector and tensor analysing power for this reaction was measured. The method and the results of the tensor polarisation measurement of the deuteron beam are presented.

  13. Interaction of a circularly polarised gravitational wave with a charged particle in a static magnetic background

    CERN Document Server

    Gangopadhyay, Sunandan; Saha, Swarup

    2014-01-01

    Interaction of a charged particle in a static magnetic background, i.e., a Landau system with circularly polarised gravitational wave (GW) is studied quantum mechanically in the long wavelength and low velocity limit. We quantize the classical Hamiltonian following \\cite{speli}. The rotating polarization vectors of the circularly polarized GW are employed to form a unique directional triad which served as the coordinate axes. The Schrodinger equations for the system are cast in the form of a set of coupled linear differential equations. This system is solved by iterative technique. We compute the time-evolution of the position and momentum expectation values of the particle. The results show that the resonance behaviour obtained earlier\\cite{emgw_classical} by classical treatements of the system has a quantum analogue not only for the linearly polarized GW \\cite{emgw_1_lin}, but for circularly polarized GW as well.

  14. 6 Mcps photon-counting X-ray computed tomography system using a 25 mm/s-scan linear LSO-MPPC detector and its application to gadolinium imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Eiichi, E-mail: dresato@iwate-med.ac.jp [Department of Physics, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694 (Japan); Oda, Yasuyuki [Department of Physics, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694 (Japan); Abudurexiti, Abulajiang [Faculty of Software and Information Science, Iwate Prefectural University, 152-52 Sugo, Takizawa, Iwate 020-0193 (Japan); Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya [The 3rd Department of Surgery, Toho University School of Medicine, 2-17-6 Ohashi, Meguro-ku, Tokyo, Iwate 153-8515 (Japan); Sugimura, Shigeaki [Tokyo Denpa Co. Ltd., 82-5 Ueno, Ichinohe, Iwate 028-5321 (Japan); Endo, Haruyuki [Iwate Industrial Research Institute, 3-35-2 Shinden, Iioka, Morioka, Iwate 020-0852 (Japan); Sato, Shigehiro [Department of Microbiology, School of Medicine, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-0023 (Japan); Ogawa, Akira [Department of Neurosurgery, School of Medicine, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-0023 (Japan); Onagawa, Jun [Department of Electronics, Faculty of Engineering, Tohoku Gakuin University, 1-13-1 Chuo, Tagajo, Miyagi 985-8537 (Japan)

    2011-12-15

    6 Mcps photon counting was carried out using a detector consisting of a 1.0 mm-thick LSO [Lu{sub 2}(SiO{sub 4})O] single-crystal scintillator and an MPPC (multipixel photon counter) module in an X-ray computed tomography (CT) system. The maximum count rate was 6 Mcps (mega counts per second) at a tube voltage of 100 kV and a tube current of 0.91 mA. Next, a photon-counting X-ray CT system consists of an X-ray generator, a turntable, a scan stage, a two-stage controller, the LSO-MPPC detector, a counter card (CC), and a personal computer (PC). Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan with a scan velocity of 25 mm/s. The pulses of the event signal from the module are counted by the CC in conjunction with the PC. The exposure time for obtaining a tomogram was 600 s at a scan step of 0.5 mm and a rotation step of 1.0{sup o}, and photon-counting CT was accomplished using gadolinium-based contrast media. - Highlights: > 6 Mcps photon counting X-ray CT performed by repeated linear scans and rotations of an object. > Detector consists of an LSO scintillator and an MPPC (multipixel photon counter) module. > Projection curves of the object obtained by the linear scan with a velocity of 25 mm/s. > Exposure time was 600 s. CT was carried out using gadolinium-based contrast media.

  15. Metastability in spin polarised Fermi gases and quasiparticle decays

    DEFF Research Database (Denmark)

    Sadeghzadeh, Kayvan; Bruun, Georg; Lobo, Carlos

    2011-01-01

    the interaction strength at which a polarised phase of molecules becomes the groundstate, to the one at which the single quasiparticle groundstate changes character from polaronic to molecular. Our argument in terms of a Fermi sea of polarons naturally suggests their use as an experimental probe. We propose...

  16. Polarised Drell-Yan measurements at $\\mathrm{COMPASS}$

    CERN Document Server

    Chiosso, Michela

    2015-01-01

    Much of the information that exists today about Transverse Momentum Dependent Parton Distribution Functions (TMDs) comes from SIDIS measurements with unpolarised and polarised beams and targets where they appear convoluted with fragmentation functions (FFs). Drell-Yan (DY) measurements are complementary to those by SIDIS experiments, as they allow to measure convolutions of only Parton Distribution Functions (PDFs) without involving FFs. Moreover, given the T-odd character of both Sivers and Boer-Mulders functions, the sign of these TMDs is expected to be reversed when observed from SIDIS or from DY. Measurements of SIDIS were performed by Compass in the period 2002 to 2007 and in 2010, using a naturally polarised μ+ beam and a solid state target polarised either longitudinally or transversely with respect to the beam direction. Now the COMPASS Experiment has the unique opportunity to access TMDs from single-polarised Drell-Yan processes as well, in the same kinematical domain of the SIDIS data and with the ...

  17. The Polarised Valence Quark Distribution from semi-inclusive DIS

    CERN Document Server

    Alekseev, M.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Arbuzov, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Chapiro, A.; Chiosso, M.; Cicuttin, A.; Colantoni, M.; Costa, S.; Crespo, M.L.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S.S.; De Masi, R.; Dedek, N.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A.M.; Donskov, S.V.; Dorofeev, V.A.; Doshita, N.; Duic, V.; Dunnweber, W.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Falaleev, V.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; Franz, J.; Friedrich, J.M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.M.; Grabmuller, S.; Grajek, O.A.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Hedicke, S.; Heinsius, F.H.; Hermann, R.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; d'Hose, N.; Ilgner, C.; Ioukaev, A.I.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Janata, A.; Jasinski, P.; Joosten, R.; Jouravlev, N.I.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Korentchenko, A.S.; Korzenev, A.; Kotzinian, A.M.; Koutchinski, N.A.; Kouznetsov, O.; Kral, A.; Kravchuk, N.P.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M.E.; Lamanna, M.; Le Goff, J.M.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.N.; Meyer, W.; Mielech, A.; Mikhailov, Yu.V.; Moinester, M.A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nahle, O.; Nassalski, J.; Neliba, S.; Nerling, F.; Neubert, S.; Neyret, D.P.; Nikolaenko, V.I.; Nikolaev, K.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panknin, R.; Panzieri, D.; Paul, S.; Pawlukiewicz-Kaminska, B.; Peshekhonov, D.V.; Peshekhonov, V.D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pretz, J.; Procureur, S.; Quintans, C.; Rajotte, J.F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Rozhdestvensky, A.M.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Sarkar, S.; Savin, I.A.; Schiavon, P.; Schill, C.; Schmitt, L.; Schonmeier, P.; Schroder, W.; Shevchenko, O.Yu.; Siebert, H.W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sugonyaev, V.P.; Sulc, M.; Sulej, R.; Tchalishev, V.V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Venugopal, G.; Virius, M.; Vlassov, N.V.; Vossen, A.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wirth, S.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhao, J.; Ziegler, R.; Zvyagin, A.

    2008-01-01

    The semi-inclusive difference asymmetry A^{h+ - h-} for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002-2004 using a 160 GeV polarised muon beam scattered off a large polarised 6-LiD target and cover the range 0.006 < x < 0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry A_d^{h+ - h-} measures the valence quark polarisation and provides an evaluation of the first moment of Delta u_v + Delta d_v which is found to be equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously measured on the same data, this result favours a non-symmetric polarisation of light quarks Delta u-bar = -Delta d-bar at a confidence level of two standard deviations, in contrast to the often assumed symmetric scenario Delta u-bar = Delta d-bar = Delta s-bar = Delta s.

  18. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

    NARCIS (Netherlands)

    Noutsos, A.; Sobey, C.; Kondratiev, V.I.; Weltevrede, P.; Verbiest, J.P.W.; Karastergiou, A.; Kramer, M.; Kuniyoshi, M.; Alexov, A.; Breton, R.P.; Bilous, A.V.; Cooper, S.; Falcke, H.; Grießmeier, J.M.; Hassall, T.E.; Hessels, J.W.T.; Keane, E.F.; Osłowski, S.; Pilia, M.; Serylak, M.; Stappers, B.W.; ter Veen, S.; van Leeuwen, J.; Zagkouris, K.; Anderson, K.; Bähren, L.; Bell, M.; Broderick, J.; Carbone, D.; Cendes, Y.; Coenen, T.; Corbel, S.; Eislöffel, J.; Fender, R.; Garsden, H.; Jonker, P.; Law, C.; Markoff, S.; Masters, J.; Miller-Jones, J.; Molenaar, G.; Osten, R.; Pietka, M.; Rol, E.; Rowlinson, A.; Scheers, B.; Spreeuw, H.; Staley, T.; Stewart, A.; Swinbank, J.; Wijers, R.; Wijnands, R.; Wise, M.; Zarka, P.; van der Horst, A.

    2015-01-01

    Aims. We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from t

  19. Flux and polarisation spectra of water clouds on exoplanets

    NARCIS (Netherlands)

    Karalidi, T.; Stam, D.M.; Hovenier, J.W.

    2011-01-01

    Context. A crucial factor for a planet’s habitability is its climate. Clouds play an important role in planetary climates. Detecting and characterising clouds on an exoplanet is therefore crucial when addressing this planet’s habitability. Aims. We present calculated flux and polarisation spectra of

  20. Spin-dipole excitations studied with tensor polarised deuteron beams

    NARCIS (Netherlands)

    Wortche, H. J.; Julin, R; Demetriuo, P; Harissopulos, SV

    2008-01-01

    Taking advantage of the spin, isospin and J(pi) selectivity of cross sections and analysing powers of the tensor polarised C-12 (d(->), He-2) reaction, the J(pi) = 0(-), 1(-), 2(-) components of the spin-dipole resonance in B-12 have been investigated. The experiment was performed at the Big-Bite Sp

  1. Macrophage polarisation: immune responses of carp against parasites

    NARCIS (Netherlands)

    Joerink, M.

    2006-01-01

    In the studies described in this thesis we used a natural host-parasite model of two parasites ( Trypanoplasma borreli and Trypanosoma carassii ) infecting common carp ( Cyprinus carpio L.), to obtain more knowledge about the phenomenon of macrophage polarisation in 'the evolutionary older' teleosts

  2. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

    NARCIS (Netherlands)

    Noutsos, A.; Sobey, C.; Kondratiev, V.I.; Weltevrede, P.; Verbiest, J.P.W.; Karastergiou, A.; Kramer, M.; Kuniyoshi, M.; Alexov, A.; Breton, R.P.; Bilous, A.V.; Cooper, S.; Falcke, H.; Griessmeier, J.-M.; Hassall, T.E.; Hessels, J.W.T.; Keane, E.F.; Oslowski, S.; Pilia, M.; Serylak, M.; Stappers, B.W.; Veen, S. ter; Leeuwen, J. van; Zagkouris, K.; Anderson, K.; Baehren, L.; Bell, M.E.; Broderick, J.; Carbone, D.; Cendes, Y.; Coenen, T.; Corbel, S.; Eisloeffel, J.; Fender, R.P.; Garsden, H.; Jonker, P.; Law, C.J.; Markoff, S.; Masters, J.; Miller-Jones, J.C.A.; Molenaar, G.; Osten, R.; Pietka, M.; Rol, E.; Rowlinson, A.; Scheers, L.H.A.; Spreeuw, H.; Staley, T.; Stewart, A.; Swinbank, J.; Wijers, R.A.M.J.; Wijnands, R.; Wise, M.W.; Zarka, P.; Horst, A. van der

    2015-01-01

    Aims: We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from t

  3. Measurement of the polarisation of a high energy muon beam

    Energy Technology Data Exchange (ETDEWEB)

    Adeva, B.; Ahmad, S.; Arvidson, A.; Badelek, B.; Ballintijn, M.K.; Bardin, G.; Baum, G.; Berglund, P.; Betev, L.; Bird, I.G.; Birsa, R.; Bjoerkholm, P.; Bonner, B.E.; Botton, N. de; Boutemeur, M.; Bradamante, F.; Bressan, A.; Bruell, A.; Buchanan, J.; Bueltmann, S.; Burtin, E.; Cavata, C.; Chen, J.P.; Clement, J.; Clocchiatti, M.; Corcoran, M.D.; Crabb, D.; Cranshaw, J.; Cuhadar, T.; Dalla Torre, S.; Dantzig, R. van; Day, D.; Demolis, J.M.; Dhawan, S.; Dulya, C.; Dupont, J.; Dyring, A.; Eichblatt, S.; Faivre, J.C.; Fasching, D.; Feinstein, F.; Fernandez, C.; Frois, B.; Garabatos, C.; Garzon, J.A.; Gatignon, L.; Gaussiran, T.; Giorgi, M.; Goeler, E. von; Gomez, A.; Gracia, G.; Grosse Perdekamp, M.; Harrach, D. von; Hasegawa, T.; Hayashi, N.; Heusch, C.A.; Horikawa, N.; Hughes, V.W.; Igo, G.; Ishimoto, S.; Iwata, T.; Jong, M. de; Kabuss, E.M.; Kaiser, R.; Karev, A.; Kessler, H.J.; Ketel, T.J.; Kishi, A.; Kisselev, Yu.; Klostermann, L.; Krivokhijine, V.; Kukhtin, V.; Kyynaeraeinen, J.; La; Spin Muon Collaboration (SMC)

    1994-04-11

    A muon beam polarimeter has been built for the SMC experiment at the CERN SPS, for muon energies of 100 to 200 GeV. The beam polarisation is determined from the energy spectrum of positrons from the decay [mu][sup +][yields]e[sup +][nu][sub e] anti [nu][sub [mu

  4. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, Florian Michael

    2009-07-09

    The doublet neutron-deuteron (nd) scattering length b{sub 2,d}, which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b{sub 2,d} can be obtained via a linear combination of the spin-independent nd scattering length b{sub c,d} and the spin-dependent one, b{sub i,d}. The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b{sub 2,d} below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b{sub i,d}. During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the

  5. Polarised radio sources : a study of luminosity, redshift and flux density

    Science.gov (United States)

    Grant, Julie Kristen

    2011-05-01

    Results of deep polarisation imaging at 1.4 GHz with the Dominion Radio Astrophysical Observatory as part of the DRAO Planck Deep Fields project are presented. This deep extragalactic field covers 15.16 deg2 centred at a2000 = 16h14m and d2000 = 54560, has an angular resolution of 4200-6200 at the field centre, and reaches a sensitivity of 55 mJy beam-1 in Stokes I and 45 mJy beam-1 in Stokes Q and U. There are 958 radio sources in Stokes I of which 136 are detected in polarisation. The Euclidean-normalized polarised differential source counts are determined down to 400 mJy. These counts indicate that sources have a higher percentage polarisation at fainter Stokes I flux density levels than for brighter sources. The majority of the polarised sources are steep-spectrum objects with a mean spectral index of -0.77, and there is no correlation between fractional polarisation and spectral index. Of the polarised sources, 77% show structure at the arc-second scale whereas only 38% of the sources with no detectable polarisation show such structure. This indicates that polarised sources tend to have structure at arcsecond scales and that the polarised emission is most likely not beamed. This confirms that the polarised radio sources tend to be lobe-dominated radio galaxies. The median percentage polarisation for resolved sources is 6.8%, while it is 4.4% for compact objects. Radio sources in the DRAO deep field have been matched with the Spitzer Wide-Area Infrared Extragalactic survey of the European Large Area ISO Survey North 1 field. In the redshift range of 0.04 FRIIs, which are seen to populate the polarized source counts at fainter flux density levels. There is no correlation between redshift and percentage polarisation for this sample. However, there is a correlation between increasing percentage polarisation and decreasing luminosity for polarised radio sources.

  6. Nucleon polarisabilities at and beyond physical pion masses

    Energy Technology Data Exchange (ETDEWEB)

    Griesshammer, Harald W. [The George Washington University, Institute for Nuclear Studies, Department of Physics, Washington, DC (United States); McGovern, Judith A. [The University of Manchester, School of Physics and Astronomy, Manchester (United Kingdom); Phillips, Daniel R. [Ohio University, Department of Physics and Astronomy and Institute of Nuclear and Particle Physics, Athens, OH (United States)

    2016-05-15

    We examine the results of Chiral Effective Field Theory (χEFT) for the scalar- and spin-dipole polarisabilities of the proton and neutron, both for the physical pion mass and as a function of m{sub π}. This provides chiral extrapolations for lattice QCD polarisability computations. We include both the leading and subleading effects of the nucleon's pion cloud, as well as the leading ones of the Δ (1232)-resonance and its pion cloud. The analytic results are complete at N{sup 2}LO in the δ counting for pion masses close to the physical value, and at leading order for pion masses similar to the Delta-nucleon mass splitting. In order to quantify the truncation error of our predictions and fits as 68% degree-of-belief intervals, we use a Bayesian procedure recently adapted to EFT expansions. At the physical point, our predictions for the spin polarisabilities are, within respective errors, in good agreement with alternative extractions using experiments and dispersion-relation theory. At larger pion masses we find that the chiral expansion of all polarisabilities becomes intrinsically unreliable as m{sub π} approaches about 300 MeV -as has already been seen in other observables. χEFT also predicts a substantial isospin splitting above the physical point for both the electric and magnetic scalar polarisabilities; and we speculate on the impact this has on the stability of nucleons. Our results agree very well with emerging lattice computations in the realm where χEFT converges. Curiously, for the central values of some of our predictions, this agreement persists to much higher pion masses. We speculate on whether this might be more than a fortuitous coincidence. (orig.)

  7. Cross-polarisation discrimination-induced interference in dual-polarised high-capacity satellite communication systems

    Directory of Open Access Journals (Sweden)

    Abdulkareem Sarki Karasuwa

    2016-05-01

    Full Text Available The design of spectrally-efficient, high-throughput satellite (HTS systems with capacity approaching one terabit per second requires operating at Ka-band frequencies and above, where there are several gigahertz of allocated radio spectrum, using multiple spot beams with dual orthogonal polarisation mode. At these high frequencies, rain attenuation poses a major obstacle to the design of high-availability satellite links which are needed for the realisation of ubiquitous broadband multimedia communication services including high-speed Internet access at rural and remote locations. Furthermore, depolarisation-induced interference in such systems could have a performance-limiting impact if a co-channel cross-polar signal combines with system noise to drive the carrier-to-noise-plus-interference ratio (CNIR below an acceptable threshold. This paper employs real measurement data to investigate the impact of depolarisation-induced interference on dual-polarised HTS systems for temperate and tropical climatic regions. Scenarios that cause significant system performance degradation are analysed, including the effects of signal frequency, antenna size, and regional rainfall rate. The impact of depolarisation on system performance is quantified by the reductions in the CNIR and link availability of a dual-polarised system when compared with those of a similarly-dimensioned single-polarised system.

  8. Azimuthal correlations in photon-photon collisions

    CERN Document Server

    Artéaga-Romero, N; Kessler, P; Ong, S; Panella, O

    1995-01-01

    Using the general helicity formula for \\gamma^* \\gamma^* collisions, we are showing that it should be possible to determine a number of independent ``structure functions'', i.e. linear combinations of elements of the two-photon helicity tensor, through azimuthal correlations in two-body or quasi two-body reactions induced by the photon-photon interaction, provided certain experimental conditions are satisfied. Numerical results of our computations are presented for some particular processes and dynamic models.

  9. 3D reconstruction of concave surfaces using polarisation imaging

    Science.gov (United States)

    Sohaib, A.; Farooq, A. R.; Ahmed, J.; Smith, L. N.; Smith, M. L.

    2015-06-01

    This paper presents a novel algorithm for improved shape recovery using polarisation-based photometric stereo. The majority of previous research using photometric stereo involves 3D reconstruction using both the diffuse and specular components of light; however, this paper suggests the use of the specular component only as it is the only form of light that comes directly off the surface without subsurface scattering or interreflections. Experiments were carried out on both real and synthetic surfaces. Real images were obtained using a polarisation-based photometric stereo device while synthetic images were generated using PovRay® software. The results clearly demonstrate that the proposed method can extract three-dimensional (3D) surface information effectively even for concave surfaces with complex texture and surface reflectance.

  10. Gender gap and polarisation of physics on global courses

    CERN Document Server

    Alinea, Allan L

    2016-01-01

    We extend on previous research on the Force Concept Inventory (FCI) given to first year classical mechanics students (N=66 students, over four years) pre and post score, for students on an international (global) course at Osaka University. In particular, we revisit the notion of "polarisation" in connection with the six polarisation-inducing questions in the FCI and examine its gender aspect. Our data suggest that this phenomenon is not unique to one gender. Furthermore, the extent by which it is exhibited by males may differ from that of females at the beginning (pretest) but the gap closes upon learning more about forces (posttest). These findings are for the most part, complemented by our result for the FCI as a whole. Although the differences in means for males and females suggest a gender gap, statistical analysis shows that there is no gender difference at the 95% confidence level.

  11. Constraining new resonant physics with top spin polarisation information

    Science.gov (United States)

    Englert, Christoph; Ferrando, James; Nordström, Karl

    2017-06-01

    We provide a comprehensive analysis of the power of including top quark-polarisation information to kinematically challenging top pair resonance searches, for which ATLAS and CMS start losing sensitivity. Following the general modelling and analysis strategies pursued by the experiments, we analyse the semi-leptonic and the di-lepton channels and show that including polarisation information can lead to large improvements in the limit setting procedures with large data sets. This will allow us to set stronger limits for parameter choices where sensitivity from the invariant mass of the top pair is not sufficient. This highlights the importance of spin observables as part of a more comprehensive set of observables to gain sensitivity to BSM resonance searches.

  12. Nucleon Polarisabilities at and Beyond Physical Pion Masses

    CERN Document Server

    Griesshammer, Harald W; Phillips, Daniel R

    2015-01-01

    We examine the results of Chiral Effective Field Theory ($\\chi$EFT) for the scalar and spin-dipole polarisabilities of the proton and neutron for the physical pion mass and as a function of $m_\\pi$, thereby providing chiral extrapolations for lattice-QCD polarisability computations. We include both the leading and sub-leading effects of the nucleon's pion cloud, as well as the leading ones of the $\\Delta(1232)$ resonance and its pion cloud. The analytic results are complete at N${}^2$LO in the $\\delta$-counting for pion masses close to the physical value, and at leading order for pion masses similar to the Delta-nucleon mass splitting. In order to quantify the truncation error of our predictions and fits as 68% degree-of-belief confidence intervals, we use a Bayesian procedure recently adapted to EFT expansions. At the physical point, our predictions for the spin polarisabilities are, within respective errors, in good agreement with alternative extractions using experiments and dispersion-relation theory. At ...

  13. Commissioning of photon beams of a flattening filter-free linear accelerator and the accuracy of beam modeling using an anisotropic analytical algorithm.

    Science.gov (United States)

    Hrbacek, Jan; Lang, Stephanie; Klöck, Stephan

    2011-07-15

    To investigate dosimetric characteristics of a new linear accelerator designed to deliver flattened, as well as flattening filter-free (FFF), beams. To evaluate the accuracy of beam modeling under physical conditions using an anisotropic analytical algorithm. Dosimetric data including depth dose curves, profiles, surface dose, penumbra, out-of-field dose, output, total and scatter factors were examined for four beams (X6, X6FFF, X10, and X10FFF) of Varian's TrueBeam machine. Beams modeled by anisotropic analytical algorithm were compared with measured dataset. FFF beams have lower mean energy (tissue-phantom ratio at the depths of 20 and 10 cm (TPR 20/10): X6, 0.667; X6FFF, 0.631; X10, 0.738; X10FFF, 0.692); maximum dose is located closer to the surface; and surface dose increases by 10%. FFF profiles have sharper but faster diverging penumbra. For small fields and shallow depths, dose outside a field is lower for FFF beams; however, the advantage fades with increasing phantom scatter. Output increases 2.26 times for X6FFF and 4.03 times for X10FFF and is less variable with field size; collimator exchange effect is reduced. A good agreement between modeled and measured data is observed. Criteria of 2% depth-dose and 2-mm distance-to-agreement are always met. Reference dosimetric characteristics of TrueBeam photon bundles were obtained, and successful modeling of the beams was achieved. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Polarisation ellipse orientation of Jovian decametric radiation

    Science.gov (United States)

    Lecacheux, Alain; Imai, Masafumi; Clarke, Tracy E.; Higgins, Charles A.; Panchenko, Mykhaylo; Konovalenko, Alexander; Brazhenko, Anatolii I.

    2016-04-01

    Unambiguous measurement of the orientation of the linearly polarized component of Jovian decametric radio emission is a long lasting question, still not solved. Indeed, the uncertainty on the (Faraday) rotation measure through the terrestrial ionosphere is of the same order of magnitude as the position angle to be measured. Simultaneous observations of Jupiter from distant ground based radio telescopes, - as those which are scheduled in 2015-2016 by using LWA1 (USA), URAN2 (Ukraine) and Nançay Decameter Array (France) -, may solve this ambiguity, since the local ionosphere effects can, in principle, be disentangled from common Jovian radiation properties. The measurement method, some first results and their theoretical implications are discussed in this talk.

  15. A high power Fabry-Perot resonator for precision Compton polarimetry with the longitudinally polarised lepton beams at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Zomer, F

    2003-12-01

    The new polarimeter, currently installed at HERA and waiting for its commissioning, is the main topic of this document. In the first chapter, studies of the impact of the polarization measurement accuracy on 3 observables, the right-handed and the standard charged current cross-sections and the determination of the light quark couplings to the Z{sup 0} are presented. The main point is that, unlike small polarisation asymmetry measurements, absolute cross section measurements are very sensitive to the polarization uncertainties. In the second chapter, the beam polarization built up and the Compton polarimetry are presented. Compton polarimetry consists in measuring and analysing the energy spectrum of photons backscattered after laser-electron interactions. The proposed polarimeter upgrade is described in chapter 3. The core of this polarimeter is a high finesse Fabry-Perot cavity filled by a 750 mW ND:YaG laser. This optical resonator, made up of 2 super-mirrors located around the electron beam, provides a few kilo Watt laser beam. The mechanical implementation at HERA and the conditions to maintain the optical resonance are discussed. The chapter 4 is dedicated to the control and measurement of the laser light polarisation. This is a very important aspect of our polarimeter since the determination of the electron beam polarization depends directly on the level of the laser circular polarisation. Before reaching the final design of the cavity installed at HERA, a prototype cavity has been built and operated at Orsay. Results of the laser/cavity alignments and performances of the laser power amplification with this prototype are described in chapter 5. (A.C.)

  16. A high power Fabry-Perot resonator for precision Compton polarimetry with the longitudinally polarised lepton beams at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Zomer, F

    2003-12-01

    The new polarimeter, currently installed at HERA and waiting for its commissioning, is the main topic of this document. In the first chapter, studies of the impact of the polarization measurement accuracy on 3 observables, the right-handed and the standard charged current cross-sections and the determination of the light quark couplings to the Z{sup 0} are presented. The main point is that, unlike small polarisation asymmetry measurements, absolute cross section measurements are very sensitive to the polarization uncertainties. In the second chapter, the beam polarization built up and the Compton polarimetry are presented. Compton polarimetry consists in measuring and analysing the energy spectrum of photons backscattered after laser-electron interactions. The proposed polarimeter upgrade is described in chapter 3. The core of this polarimeter is a high finesse Fabry-Perot cavity filled by a 750 mW ND:YaG laser. This optical resonator, made up of 2 super-mirrors located around the electron beam, provides a few kilo Watt laser beam. The mechanical implementation at HERA and the conditions to maintain the optical resonance are discussed. The chapter 4 is dedicated to the control and measurement of the laser light polarisation. This is a very important aspect of our polarimeter since the determination of the electron beam polarization depends directly on the level of the laser circular polarisation. Before reaching the final design of the cavity installed at HERA, a prototype cavity has been built and operated at Orsay. Results of the laser/cavity alignments and performances of the laser power amplification with this prototype are described in chapter 5. (A.C.)

  17. Photon-Photon Collisions -- Past and Future

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC

    2005-12-02

    I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy {gamma}{gamma} and e{gamma} tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy {gamma}{gamma} collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider.

  18. Can axion-like particles explain the alignments of the polarisations of light from quasars?

    CERN Document Server

    Payez, A; Hutsemékers, D

    2011-01-01

    The standard axion-like particle explanation of the observed large-scale coherent orientations of quasar polarisation vectors is ruled out by the recent measurements of vanishing of circular polarisation. We introduce a more general wave-packet formalism and show that, although decoherence effects between waves of different frequencies can reduce significantly the amount of circular polarisation, the axion-like particle hypothesis is disfavoured given the bandwidth with which part of the observations were performed. Finally, we show that a more sophisticated model of extragalactic fields does not lead to an alignment of polarisations.

  19. Hole-Initiated-Avalanche, Linear-Mode, Single-Photon-Sensitive Avalanche Photodetector with Reduced Excess Noise and Low Dark Count Rate Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A radiation hard, single photon sensitive InGaAs avalanche photodiode (APD) receiver technology will be demonstrated useful for long range space based optical...

  20. SU-E-T-313: Dosimetric Deviation of Misaligned Beams for a 6 MV Photon Linear Accelerator Using Monte Carlo Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S [Advocate Lutheran General Hospital, Park Ridge, IL (United States)

    2015-06-15

    Purpose: To quantify the dosimetric variations of misaligned beams for a linear accelerator by using Monte Carlo (MC) simulations. Method and Materials: Misaligned beams of a Varian 21EX Clinac were simulated to estimate the dosimetric effects. All the linac head components for a 6 MV photon beam were implemented in BEAMnrc/EGSnrc system. For incident electron beam parameters, 6 MeV with 0.1 cm full-width-half-max Gaussian beam was used. A phase space file was obtained below the jaw per each misalignment condition of the incident electron beam: (1) The incident electron beams were tilted by 0.5, 1.0 and 1.5 degrees on the x-axis from the central axis. (2) The center of the incident electron beam was off-axially moved toward +x-axis by 0.1, 0.2, and 0.3 cm away from the central axis. Lateral profiles for each misaligned beam condition were acquired at dmax = 1.5 cm and 10 cm depth in a rectangular water phantom. Beam flatness and symmetry were calculated by using the lateral profile data. Results: The lateral profiles were found to be skewed opposite to the angle of the incident beam for the tilted beams. For the displaced beams, similar skewed lateral profiles were obtained with small shifts of penumbra on the +x-axis. The variations of beam flatness were 3.89–11.18% and 4.12–42.57% for the tilted beam and the translated beam, respectively. The beam symmetry was separately found to be 2.95 −9.93% and 2.55–38.06% separately. It was found that the percent increase of the flatness and the symmetry values are approximated 2 to 3% per 0.5 degree tilt or per 1 mm displacement. Conclusion: This study quantified the dosimetric effects of misaligned beams using MC simulations. The results would be useful to understand the magnitude of the dosimetric deviations for the misaligned beams.

  1. Measurement of high-Q{sup 2} neutral current deep inelastic e{sup -}p scattering cross sections with a longitudinally polarised electron beam at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Lab., Argonne, IL (US)] (and others)

    2008-12-15

    Measurements of the neutral current cross sections for deep inelastic scattering in e{sup -}p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections d{sigma}/dQ{sup 2}, d{sigma}/dx and d{sigma}/dy and the double-differential cross sections in Q{sup 2} and x are measured in the kinematic region y < 0.9 and Q{sup 2} > 185GeV{sup 2} for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9 pb{sup -1} taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318GeV. The structure functions xF{sub 3} and xF{sub 3}{sup {gamma}}{sup Z} are determined by combining the e{sup -}p results presented in this paper with previously measured e{sup +}p neutral current data. The asymmetry parameter A{sup -} is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model. (orig.)

  2. The impact of surface chemistry modification on macrophage polarisation.

    Science.gov (United States)

    Rostam, Hassan M; Singh, Sonali; Salazar, Fabian; Magennis, Peter; Hook, Andrew; Singh, Taranjit; Vrana, Nihal E; Alexander, Morgan R; Ghaemmaghami, Amir M

    2016-11-01

    Macrophages are innate immune cells that have a central role in combating infection and maintaining tissue homeostasis. They exhibit remarkable plasticity in response to environmental cues. At either end of a broad activation spectrum are pro-inflammatory (M1) and anti-inflammatory (M2) macrophages with distinct functional and phenotypical characteristics. Macrophages also play a crucial role in orchestrating immune responses to biomaterials used in the fabrication of implantable devices and drug delivery systems. To assess the impact of different surface chemistries on macrophage polarisation, human monocytes were cultured for 6 days on untreated hydrophobic polystyrene (PS) and hydrophilic O2 plasma-etched polystyrene (O2-PS40) surfaces. Our data clearly show that monocytes cultured on the hydrophilic O2-PS40 surface are polarised towards an M1-like phenotype, as evidenced by significantly higher expression of the pro-inflammatory transcription factors STAT1 and IRF5. By comparison, monocytes cultured on the hydrophobic PS surface exhibited an M2-like phenotype with high expression of mannose receptor (MR) and production of the anti-inflammatory cytokines IL-10 and CCL18. While the molecular basis of such different patterns of cell differentiation is yet to be fully elucidated, we hypothesise that it is due to the adsorption of different biomolecules on these surface chemistries. Indeed our surface characterisation data show quantitative and qualitative differences between the protein layers on the O2-PS40 surface compared to PS surface which could be responsible for the observed differential macrophage polarisation on each surface.

  3. A polarised SUSANS facility to study magnetic systems

    Indian Academy of Sciences (India)

    Apoorva G Wagh; Veer Chand Rakhecha; Markus Strobl; Wolfgang Treimer

    2004-08-01

    Using a right-angled magnetic air prism, we have achieved a separation of ∼ 10 arcsec between ∼ 2 arcsec wide up- and down-spin peaks of 5.4 Å neutrons. The polarised neutron option has thus been introduced into the SUSANS instrument. Strongly spin-dependent SUSANS spectra have been observed over ±1.3 × 10−4 Å -1 range for several magnetic alloy samples. Spatial pair-distribution functions for the up- and down-spins as well as the nuclear and magnetic scattering length density distributions in the micrometer domain, have been deduced from these spectra.

  4. Studies of quarkonia production and polarisation at LHCb

    CERN Document Server

    Frosini, M

    2013-01-01

    Studies of quarkonia production in the forward region provide important tests of NRQCD. The LHCb experiment has collected a dataset corresponding to an integrated luminosity of about 3 fb$^{-1}$ in proton-proton collisions at $\\sqrt{s}$= 7 and 8 TeV. We present studies of the production and polarisation of the $J/\\psi, \\psi$(2S) and $\\chi_c$ charmonium states as well as those of $\\Upsilon$ and $\\chi_b$ bottomonia. Absolute and relative production cross-sections are presented and compared to the most recent theoretical predictions when available. We also discuss the future prospects for these measurements.

  5. Measurement of the charged-pion polarisability at COMPASS

    CERN Document Server

    Guskov, Alexey

    2015-01-01

    The electric (${\\alpha}_{\\pi}$) and the magnetic (${\\beta}_{\\pi}$) polarisabilities are fundamental properties of the pion characterising the rigidity of its internal structure. They have been precisely measured at the COMPASS experiment at CERN with a ${\\pi}^{-}$ beam of 190~GeV/c assuming ${\\alpha}_{\\pi}+{\\beta}_{\\pi}=0$. Muons of the same momentum were used for controlling of systematic effects. The obtained result ${\\alpha}_{\\pi}=-{\\beta}_{\\pi}=(2.0\\pm 0.6_{stat.}\\pm 0.7_{syst.})\\times 10^{-4} fm^3$ is in agreement with the prediction of the Chiral Perturbation Theory.

  6. Gluon polarisation from high transverse momentum hadron pairs production (COMPASS)

    CERN Document Server

    Silva, L

    2010-01-01

    A new preliminary result of a gluon polarisation $\\Delta G/G$ obtained selecting high transverse momentum hadron pairs in DIS events with $Q^2>1 \\ ({GeV/}c)^2$ is presented. Data has been collected by COMPASS at CERN during the 2002-2004 years. In the extraction of $\\Delta G/G$ contributions coming from the leading order $\\gamma q$ and QCD processes are taken into account. A new weighting method based on a neural network approach is used. Also a preliminary result of $\\Delta G/G$ for events with $Q^2<1 \\ ({GeV/}c)^2$ is presented.

  7. Determination of the gluon polarisation in the nucleon in the production of hadrons with high transverse momentum at Compass; Determination de la polarisation des gluons dans le nucleon par la production de hadrons a grande impulsion transverse a COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Procureur, S

    2006-07-15

    The main goal of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, V. For this, the helicity asymmetry of the photon gluon fusion process is measured, in the scattering of polarized muons on a polarised deuteron target. This process can be tagged by the production of hadrons with high transverse momentum (pT), that allows to get a large statistics. On the other hand, a physical background remains and complicates the extraction of V. This PhD thesis presents different studies performed to optimize the determination of c in this channel. In particular, a study of the alignment of the 200 detection planes is presented, leading to an improvement of the spectrometer resolution. Performances of the 12 Micromegas detectors have also been determined during 2004 run. Then, the asymmetries obtained in the analysis of 2002 to 2004 data are calculated, for various high PT selections: production of 1 or 2 hadrons, at low or high Q2. An optimization of the selection, based on a neural network, has also been developed, and a detailed study of the experimental false asymmetry has been performed. V extraction is then described, based on Monte Carlo simulations (using PYTHIA or LEPTO). For the first time, the asymmetry of the so-called resolved photon processes is estimated. An improvement on the reconstruction of nucleon momentum fraction carried by the gluon is also proposed, by reconstructing pseudo-jets. Finally, small values obtained for GG are discussed, in terms of constraints on the gluon contribution to the nucleon spin. (author)

  8. Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons

    CERN Document Server

    Adolph, C; Akhunzyanov, R; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anfimov, N V; Anosov, V; Augsten, K; Augustyniak, W; Austregesilo, A; Azevedo, C D R; Badełek, B; Balestra, F; Ball, M; Barth, J; Beck, R; Bedfer, Y; Bernhard, J; Bicker, K; Bielert, E R; Birsa, R; Bodlak, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Buchele, M; Chang, W-C; Chatterjee, C; Chiosso, M; Choi, I; Chung, S-U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Dreisbach, Ch; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger jr, M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Fuchey, E; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Giarra, J; Giordano, F; Gnesi, I; Gorzellik, M; Grabmuller, S; Grasso, A; Grosse Perdekamp, M; Grube, B; Grussenmeyer, T; Guskov, A; Haas, F; Hahne, D; Hamar, G; von Harrach, D; Heinsius, F H; Heitz, R; Herrmann, F; Horikawa, N; d’Hose, N; Hsieh, C-Y; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jary, V; Joosten, R; Jorg, P; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O M; Kramer, M; Kremser, P; Krinner, F; Kroumchtein, Z V; Kulinich, Y; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lian, Y-S; Lichtenstadt, J; Longo, R; Maggiora, A; Magnon, A; Makins, N; Makke, N; Mallot, G K; Marianski, B; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G V; Meyer, M; Meyer, W; Mikhailov, Yu V; Mikhasenko, M; Mitrofanov, E; Mitrofanov, N; Miyachi, Y; Nagaytsev, A; Nerling, F; Neyret, D; Novy, J; Nowak, W-D; Nukazuka, G; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panzieri, D; Parsamyan, B; Paul, S; Peng, J-C; Pereira, F; Pesek, M; Peshekhonov, D V; Pierre, N; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Riedl, C; Roskot, M; Rossiyskaya, N S; Ryabchikov, D I; Rybnikov, A; Rychter, A; Salac, R; Samoylenko, V D; Sandacz, A; Santos, C; Sarkar, S; Savin, I A; Sawada, T; Sbrizzai, G; Schiavon, P; Schmidt, K; Schmieden, H; Schonning, K; Seder, E; Selyunin, A; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Smolik, J; Srnka, A; Steffen, D; Stolarski, M; Subrt, O; Sulc, M; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; Tasevsky, M; Tessaro, S; Tessarotto, F; Thibaud, F; Thiel, A; Tosello, F; Tskhay, V; Uhl, S; Veloso, J; Virius, M; Vondra, J; Wallner, S; Weisrock, T; Wilfert, M; ter Wolbeek, J; Zaremba, K; Zavada, P; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M; Zink, A

    2016-01-01

    Single hadron azimuthal asymmetries in the cross sections of positive and negative hadron production in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\\phi$ is obtained by means of a five-parameter fitting function that besides a $\\phi$-independent term includes four modulations predicted by theory: $\\sin\\phi$, $\\sin 2 \\phi$, $\\sin 3\\phi$ and $\\cos\\phi$. The amplitudes of the five terms have been first extracted for the data integrated over all kinematic variables. In further fits, the $\\phi$-dependence is determined as a function of one of three kinematic variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the other two. Except the $\\phi$-independent term, all the modulation amplitudes are very small, and no cl...

  9. Time-resolved proton polarisation (TPP) images tyrosyl radical sites in bovine liver catalase.

    Science.gov (United States)

    Zimmer, Oliver; Jouve, Hélène M.; Stuhrmann, Heinrich B.

    2017-05-01

    A differentiation between dynamic polarised protons close to tyrosyl radical sites in catalase and those of the bulk is achieved by time-resolved polarised neutron scattering. Three radical sites, all of them being close to the molecular centre and the heme, appear to be equally possible. Among these is tyr-369 the radial site of which had previously been proven by EPR.

  10. The effect of cathodic polarisation on monosaccharides of Amphora coffeaeformis, a marine fouling diatom

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Evans, L.V.; Edyvean, R.G.J.

    , concentrations of monosaccharides were higher by a factor of 8 to 40 in A. coffeaeformis cells attached to non-polarised steel. The abundance of monosaccharides increased over the period of cultivation in the cells on non-polarised steel. Eight individual...

  11. Design of a Polarised Positron Source Based on Laser Compton Scattering

    CERN Document Server

    Araki, S; Honda, Y; Kurihara, Y; Kuriki, M; Okugi, T; Omori, T; Taniguchi, T; Terunuma, N; Urakawa, J; Artru, X; Chevallier, M; Strakhovenko, V M; Bulyak, E; Gladkikh, P; Mönig, K; Chehab, R; Variola, A; Zomer, F; Guiducci, S; Raimondi, Pantaleo; Zimmermann, Frank; Sakaue, K; Hirose, T; Washio, M; Sasao, N; Yokoyama, H; Fukuda, M; Hirano, K; Takano, M; Takahashi, T; Sato, H; Tsunemi, A; Gao, J; Soskov, V

    2005-01-01

    We describe a scheme for producing polarised positrons at the ILC from polarised X-rays created by Compton scattering of a few-GeV electron beam off a CO2 or YAG laser. This scheme is very energy effective using high finesse laser cavities in conjunction with an electron storage ring.

  12. Photon collider Higgs factories

    CERN Document Server

    Telnov, V I

    2014-01-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  13. ILL polarised hot-neutron beam facility D3

    Energy Technology Data Exchange (ETDEWEB)

    Lelievre-Berna, E. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France)]. E-mail: lelievre@ill.fr; Bourgeat-Lami, E. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Gibert, Y. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Kernavanois, N. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Locatelli, J. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Mary, T. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Pastrello, G. [AZ-Systeme, 38170 Seyssinet-Pariset (France); Petukhov, A. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Pujol, S. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Rouques, R. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Thomas, F. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Thomas, M. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France); Tasset, F. [Institut Laue-Langevin, 6, rue J. Horowitz, BP 156, Cedex 9, 38042 Grenoble (France)

    2005-02-15

    D3 is a very comprehensive polarised beam facility at the renewed hot neutron source of the Institut Laue-Langevin (ILL). In magnetic field up to 10T, it exploits the spin dependency of the neutron scattering cross-section for determining unpaired electron magnetisation in crystals. The technique applies very successfully to molecular compounds, heavy fermions, high-Tc superconductors, transition metals and actinide alloys.Within the frame of the ILL Millennium Programme, we have recently added polarisation analysis by taking advantage of {sup 3}He spin filters and built a dedicated third-generation Cryopad for carrying out spherical neutron polarimetry experiments. In the case of magnetic structures, this leads to the direct determination of the magnetic interaction vector. Hence, D3 has become one of the most powerful tool for solving complex AF structures that had proven to be intractable when employing other techniques. Moreover, when the magnetic and nuclear scattering occur at the same position in the reciprocal space, it allows a precise determination of the AF magnetisation distributions.D3 can also be used for many purposes other than diffraction experiments, e.g. the search for the T-odd asymmetry of light particle emission in Pu239 ternary fission.

  14. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1988-07-01

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  15. Polarisation in the auroral red line during coordinated EISCAT Svalbard Radar/optical experiments

    Directory of Open Access Journals (Sweden)

    M. Barthélémy

    2011-06-01

    Full Text Available The polarisation of the atomic oxygen red line in the Earth's thermosphere is observed in different configurations with respect to the magnetic field line at high latitude during several coordinated Incoherent Scatter radar/optical experiment campaigns. When pointing northward with a line-of-sight nearly perpendicular to the magnetic field, we show that, as expected, the polarisation is due to precipitated electrons with characteristic energies of a few hundreds of electron Volts. When pointing toward the zenith or southward with a line-of-sight more parallel to the magnetic field, we show that the polarisation practically disappears. This confirms experimentally the predictions deduced from the recent discovery of the red line polarisation. We show that the polarisation direction is parallel to the magnetic field line during geomagnetic activity intensification and that these results are in agreement with theoretical work.

  16. Interaction of a circularly polarised gravitational wave with a charged particle in a static magnetic background

    Science.gov (United States)

    Gangopadhyay, Sunandan; Saha, Anirban; Saha, Swarup

    2015-06-01

    Interaction of a charged particle in a static magnetic background, i.e., a Landau system with circularly polarised gravitational wave (GW) is studied quantum mechanically in the long wavelength and low velocity limit. We quantize the classical Hamiltonian following (Speliotopoulos in Phys Rev D 51:1701, 1995). The rotating polarization vectors of the circularly polarized GW are employed to form a unique directional triad which served as the coordinate axes. The Schrodinger equations for the system are cast in the form of a set of coupled linear differential equations. This system is solved by iterative technique. We compute the time-evolution of the position and momentum expectation values of the particle. The results show that the resonance behaviour obtained earlier (Macedo and Nelson in Astrophys J 362:584, 1990; Papadopoulos in Astron Astrophys 396:1045, 2002) by classical treatements of the system has a quantum analogue not only for the linearly polarized GW (Gangopadhyay and Saha in Mod Phys Lett A 27:1250192, 2012), but for circularly polarized GW as well.

  17. Nonlinear silicon photonics

    Science.gov (United States)

    Borghi, M.; Castellan, C.; Signorini, S.; Trenti, A.; Pavesi, L.

    2017-09-01

    Silicon photonics is a technology based on fabricating integrated optical circuits by using the same paradigms as the dominant electronics industry. After twenty years of fervid development, silicon photonics is entering the market with low cost, high performance and mass-manufacturable optical devices. Until now, most silicon photonic devices have been based on linear optical effects, despite the many phenomenologies associated with nonlinear optics in both bulk materials and integrated waveguides. Silicon and silicon-based materials have strong optical nonlinearities which are enhanced in integrated devices by the small cross-section of the high-index contrast silicon waveguides or photonic crystals. Here the photons are made to strongly interact with the medium where they propagate. This is the central argument of nonlinear silicon photonics. It is the aim of this review to describe the state-of-the-art in the field. Starting from the basic nonlinearities in a silicon waveguide or in optical resonator geometries, many phenomena and applications are described—including frequency generation, frequency conversion, frequency-comb generation, supercontinuum generation, soliton formation, temporal imaging and time lensing, Raman lasing, and comb spectroscopy. Emerging quantum photonics applications, such as entangled photon sources, heralded single-photon sources and integrated quantum photonic circuits are also addressed at the end of this review.

  18. Effect of wedge filter and field size on photoneutron dose equivalent for an 18 MV photon beam of a medical linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Mesbahi, Asghar [Medical Physics Department, Medical School, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Radiation Therapy Department, Imam Hospital, Tabriz (Iran, Islamic Republic of)], E-mail: asgharmesbahi@yahoo.com; Keshtkar, Ahmad [Medical Physics Department, Medical School, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Mohammadi, Ehsan [Radiation Therapy Department, Imam Khomeini Hospital, Tehran (Iran, Islamic Republic of); Mohammadzadeh, Mohammad [Radiation Therapy Department, Imam Hospital, Tabriz (Iran, Islamic Republic of)

    2010-01-15

    Photoneutrons produced during radiation therapy with high energy photons is the main source of unwanted out-of-field received doses of patients. To analyze the neutron dose equivalent (NDE) for wedged beams and its variation with field size, Monte Carlo (MC) modeling of an 18 MV photon beam was performed using MCNPX MC code. The results revealed that the NDE is on average 6.5 times higher for wedged beams. For open beams, the NDE decreased with increasing field size especially for field sizes >20x20 cm{sup 2}. While, for wedged beams, the NDE increased with field size. It was suggested that the increase of NDE for wedged beams should be taken into account in radiation-induced secondary cancer risk estimations and radiation protection calculations.

  19. Observation of Polarised Microwave Emission from Cosmic Ray Air Showers

    CERN Document Server

    Smida, R; Engel, R; Arteaga-Velazquez, J C; Bekk, K; Bertaina, M; Bluemer, J; Bozdog, H; Brancus, I M; Chiavassa, A; Cossavella, F; Di Pierro, F; Doll, P; Fuchs, B; Fuhrmann, D; Grupen, C; Haungs, A; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H; Kleifges, M; Kroemer, O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Mathys, S; Melissas, M; Morello, C; Neunteufel, P; Oehlschlaeger, J; Palmieri, N; Pekala, J; Pierog, T; Rautenberg, J; Rebel, H; Riegel, M; Roth, M; Salamida, F; Schieler, H; Schoo, S; Schroeder, F G; Sima, O; Stasielak, J; Toma, G; Trinchero, G C; Unger, M; Weber, M; Weindl, A; Wilczynski, H; Will, M; Wochele, J; Zabierowski, J

    2013-01-01

    We report on the first direct measurement of the basic features of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the CROME (Cosmic-Ray Observation via Microwave Emission) experiment have been read out and searched for signatures of radio emission by high-energy air showers. Microwave signals have been detected for more than 30 showers with energies above $3\\times10^{16}$\\,eV. The observations presented in this Letter are consistent with a mainly forward-beamed, coherent and polarised emission process in the GHz frequency range. An isotropic, unpolarised radiation is disfavoured as the dominant emission model. The measurements show that microwave radiation offers a new means of studying air showers at very high energy.

  20. Exclusive $\\rho^0$ muoproduction on transversely polarised protons and deuterons

    CERN Document Server

    Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Buechele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Torre, S Dalla; Das, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Duennweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, jr, M; Fischer, H; Franco, C; von Hohenesche, N du Fresne; Friedrich, J M; Frolov, V; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmueller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthoerl, T; Haas, F; von Harrach, D; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoeppner, Ch; d'Hose, N; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Koenigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kraemer, M; Kroumchtein, Z V; Kunne, F; Kurek, K; Lauser, L; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Moinester, M A; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Negrini, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W -D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Rajotte, J -F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlueter, T; Schmidt, K; Schmitt, L; Schoenning, K; Schopferer, S; Schott, M; Schroeder, W; Shevchenko, O Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Sznajder, P; Takekawa, S; Ter Wolbeek, J; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Wilfert, M; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A

    2012-01-01

    The transverse target spin azimuthal asymmetry A_UT in hard exclusive production of rho^0 mesons was measured at COMPASS by scattering 160 GeV/c muons off transversely polarised protons and deuterons. The measured asymmetry is sensitive to the nucleon helicity-flip generalised parton distributions E^q, which are related to the orbital angular momentum of quarks in the nucleon. The Q^2, x_B and p_t^2 dependence of A_UT is presented in a wide kinematic range. Results for deuterons are obtained for the first time. The measured asymmetry is small in the whole kinematic range for both protons and deuterons, which is consistent with the theoretical interpretation that contributions from GPDs E^u and E^d approximately cancel.

  1. Large-Angle CMB Suppression and Polarisation Predictions

    CERN Document Server

    Copi, C.J.; Schwarz, D.J.; Starkman, G.D.

    2013-01-01

    The anomalous lack of large angle temperature correlations has been a surprising feature of the CMB since first observed by COBE-DMR and subsequently confirmed and strengthened by WMAP. This anomaly may point to the need for modifications of the standard model of cosmology or may show that our Universe is a rare statistical fluctuation within that model. Further observations of the temperature auto-correlation function will not elucidate the issue; sufficiently high precision statistical observations already exist. Instead, alternative probes are required. In this work we explore the expectations for forthcoming polarisation observations. We define a prescription to test the hypothesis that the large-angle CMB temperature perturbations in our Universe represent a rare statistical fluctuation within the standard cosmological model. These tests are based on the temperature-Q Stokes parameter correlation. Unfortunately these tests cannot be expected to be definitive. However, we do show that if this TQ-correlati...

  2. Vacuum polarisation in some static nonuniform magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Calucci, G. [Trieste Univ. (Italy). Dip. di Fisica Teorica]|[INFN, Trieste (Italy)

    1995-11-01

    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum.

  3. Denoising time-domain induced polarisation data using wavelet techniques

    Science.gov (United States)

    Deo, Ravin N.; Cull, James P.

    2016-05-01

    Time-domain induced polarisation (TDIP) methods are routinely used for near-surface evaluations in quasi-urban environments harbouring networks of buried civil infrastructure. A conventional technique for improving signal to noise ratio in such environments is by using analogue or digital low-pass filtering followed by stacking and rectification. However, this induces large distortions in the processed data. In this study, we have conducted the first application of wavelet based denoising techniques for processing raw TDIP data. Our investigation included laboratory and field measurements to better understand the advantages and limitations of this technique. It was found that distortions arising from conventional filtering can be significantly avoided with the use of wavelet based denoising techniques. With recent advances in full-waveform acquisition and analysis, incorporation of wavelet denoising techniques can further enhance surveying capabilities. In this work, we present the rationale for utilising wavelet denoising methods and discuss some important implications, which can positively influence TDIP methods.

  4. Non-polarisable dry electrode based on NASICON ceramic.

    Science.gov (United States)

    Gondran, C; Siebert, E; Fabry, P; Novakov, E; Gumery, P Y

    1995-05-01

    A NASICON-type ceramic (high sodium ion conductor) is proposed to record bioelectric signals. The electrode does not need gel before its application. The principle of the measurements is based on a sodium ion exchange between the skin and the material. Electrical measurements performed in saline solutions show that the electrode is slightly polarisable. The skin-electrode impedance was investigated. The impedance decreases as a function of the time of application. The resistive component is the major source of the impedance change. This can be explained by the perspiration process which occurs immediately with time after the application of the NASICON-based electrode on the skin. The skin condition is also an important parameter. NaCl saline solution or abrasion causes the resistance to decrease markedly.

  5. Resolving dispersion and induction components for polarisable molecular simulations of ionic liquids

    Science.gov (United States)

    Pádua, Agílio A. H.

    2017-05-01

    One important development in interaction potential models, or atomistic force fields, for molecular simulation is the inclusion of explicit polarisation, which represents the induction effects of charged or polar molecules on polarisable electron clouds. Polarisation can be included through fluctuating charges, induced multipoles, or Drude dipoles. This work uses Drude dipoles and is focused on room-temperature ionic liquids, for which fixed-charge models predict too slow dynamics. The aim of this study is to devise a strategy to adapt existing non-polarisable force fields upon addition of polarisation, because induction was already contained to an extent, implicitly, due to parametrisation against empirical data. Therefore, a fraction of the van der Waals interaction energy should be subtracted so that the Lennard-Jones terms only account for dispersion and the Drude dipoles for induction. Symmetry-adapted perturbation theory is used to resolve the dispersion and induction terms in dimers and to calculate scaling factors to reduce the Lennard-Jones terms from the non-polarisable model. Simply adding Drude dipoles to an existing fixed-charge model already improves the prediction of transport properties, increasing diffusion coefficients, and lowering the viscosity. Scaling down the Lennard-Jones terms leads to still faster dynamics and densities that match experiment extremely well. The concept developed here improves the overall prediction of density and transport properties and can be adapted to other models and systems. In terms of microscopic structure of the ionic liquids, the inclusion of polarisation and the down-scaling of Lennard-Jones terms affect only slightly the ordering of the first shell of counterions, leading to small decreases in coordination numbers. Remarkably, the effect of polarisation is major beyond first neighbours, significantly weakening spatial correlations, a structural effect that is certainly related to the faster dynamics of

  6. Polarisation effects in twin-core fibre: Application for mode locking in a fibre laser

    Science.gov (United States)

    Lobach, I. A.; Kablukov, S. I.; Podivilov, Evgenii V.; Babin, Sergei A.; Apolonski, A. A.

    2012-09-01

    We report the first measurements of the longitudinal power distribution in a twin-core optical fibre at different input light polarisations. Experimental evidence is presented that, because of the difference in birefringence between the cores, the power in them depends on which core the beam is launched into. Experimental data are interpreted in terms of a modified polarisation model for mode coupling in twin-core fibres which takes into account the birefringence of the cores. In addition, we demonstrate for the first time the use of the polarisation properties of a twincore fibre for mode locking in a fibre laser.

  7. Polarisation effects in twin-core fibre: Application for mode locking in a fibre laser

    Energy Technology Data Exchange (ETDEWEB)

    Lobach, I A; Kablukov, S I; Podivilov, Evgenii V; Babin, Sergei A; Apolonski, A A

    2012-09-30

    We report the first measurements of the longitudinal power distribution in a twin-core optical fibre at different input light polarisations. Experimental evidence is presented that, because of the difference in birefringence between the cores, the power in them depends on which core the beam is launched into. Experimental data are interpreted in terms of a modified polarisation model for mode coupling in twin-core fibres which takes into account the birefringence of the cores. In addition, we demonstrate for the first time the use of the polarisation properties of a twincore fibre for mode locking in a fibre laser. (optical fibres, lasers and amplifiers. properties and applications)

  8. A virtual photon source model of an Elekta linear accelerator with integrated mini MLC for Monte Carlo based IMRT dose calculation.

    Science.gov (United States)

    Sikora, M; Dohm, O; Alber, M

    2007-08-07

    A dedicated, efficient Monte Carlo (MC) accelerator head model for intensity modulated stereotactic radiosurgery treatment planning is needed to afford a highly accurate simulation of tiny IMRT fields. A virtual source model (VSM) of a mini multi-leaf collimator (MLC) (the Elekta Beam Modulator (EBM)) is presented, allowing efficient generation of particles even for small fields. The VSM of the EBM is based on a previously published virtual photon energy fluence model (VEF) (Fippel et al 2003 Med. Phys. 30 301) commissioned with large field measurements in air and in water. The original commissioning procedure of the VEF, based on large field measurements only, leads to inaccuracies for small fields. In order to improve the VSM, it was necessary to change the VEF model by developing (1) a method to determine the primary photon source diameter, relevant for output factor calculations, (2) a model of the influence of the flattening filter on the secondary photon spectrum and (3) a more realistic primary photon spectrum. The VSM model is used to generate the source phase space data above the mini-MLC. Later the particles are transmitted through the mini-MLC by a passive filter function which significantly speeds up the time of generation of the phase space data after the mini-MLC, used for calculation of the dose distribution in the patient. The improved VSM model was commissioned for 6 and 15 MV beams. The results of MC simulation are in very good agreement with measurements. Less than 2% of local difference between the MC simulation and the diamond detector measurement of the output factors in water was achieved. The X, Y and Z profiles measured in water with an ion chamber (V = 0.125 cm(3)) and a diamond detector were used to validate the models. An overall agreement of 2%/2 mm for high dose regions and 3%/2 mm in low dose regions between measurement and MC simulation for field sizes from 0.8 x 0.8 cm(2) to 16 x 21 cm(2) was achieved. An IMRT plan film verification

  9. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  10. Spectrally narrow polarisation conversion in a slow-light photonic crystal waveguide

    DEFF Research Database (Denmark)

    Canning, John; Kristensen, Martin; Skivesen, Nina;

    2009-01-01

    A narrow-band (3 dB bandpass waveguide is demonstrated. Signal contrast between quasi- TE and TM eigenstates exceeding 40 dB is achieved. Further, multiple resonant wavelength coupling between the two...

  11. Study of clathrate hydrates via equilibrium molecular-dynamics simulation employing polarisable and non-polarisable, rigid and flexible water models

    Science.gov (United States)

    Burnham, Christian J.; English, Niall J.

    2016-04-01

    Equilibrium molecular-dynamics (MD) simulations have been performed on metastable sI and sII polymorphs of empty hydrate lattices, in addition to liquid water and ice Ih. The non-polarisable TIP4P-2005, simple point charge model (SPC), and polarisable Thole-type models (TTM): TTM2, TTM3, and TTM4 water models were used in order to survey the differences between models and to see what differences can be expected when polarisability is incorporated. Rigid and flexible variants were used of each model to gauge the effects of flexibility. Power spectra are calculated and compared to density-of-states spectra inferred from inelastic neutron scattering (INS) measurements. Thermodynamic properties were also calculated, as well as molecular-dipole distributions. It was concluded that TTM models offer optimal fidelity vis-à-vis INS spectra, together with thermodynamic properties, with the flexible TTM2 model offering optimal placement of vibrational modes.

  12. A polarisation modulation scheme for measuring vacuum magnetic birefringence with static fields

    CERN Document Server

    Zavattini, G; Ejlli, A; Ruoso, G

    2016-01-01

    A novel polarisation modulation scheme for polarimeters based on Fabry-Perot cavities is presented. The application to the proposed HERA-X experiment aiming to measuring the magnetic birefringence of vacuum with the HERA superconducting magnets is discussed.

  13. A polarisation modulation scheme for measuring vacuum magnetic birefringence with static fields

    Energy Technology Data Exchange (ETDEWEB)

    Zavattini, G.; Ejlli, A. [Universita di Ferrara, Dipt. di Fisica e Scienze della Terra (Italy); INFN, Sezione di Ferrara (Italy); Della Valle, F. [Universita di Trieste, Dipt. di Fisica, Trieste (Italy); INFN, Sezione di Trieste, TS (Italy); Ruoso, G. [INFN, Lab. Nazionali di Legnaro (Italy)

    2016-05-15

    A novel polarisation modulation scheme for polarimeters based on Fabry-Perot cavities is presented. The application to the measurement of the magnetic birefringence of vacuum with the HERA superconducting magnets in the ALPS-II configuration is discussed. (orig.)

  14. Heavy-quark QCD vacuum polarisation function. Analytical results at four loops

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Kotikov, A.V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2006-07-15

    The first two moments of the heavy-quark vacuum polarisation function at four loops in quantum chromo-dynamics are found in fully analytical form by evaluating the missing massive four-loop tadpole master integrals. (orig.)

  15. First Measurement of Charged Current Cross Sections at HERA with Longitudinally Polarised Positrons

    CERN Document Server

    Aktas, A; Anthonis, T; Antunovic, B; Aplin, S; Asmone, A; Astvatsatourov, A; Babaev, A; Backovic, S; Bähr, J; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baudrand, S; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bracinik, J; Brandt, G; Brisson, V; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Contreras, J G; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; De Boer, Y; Delcourt, B; Del Degan, M; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dodonov, V; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Elsen, E; Erdmann, W; Essenov, S; Falkewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Feltesse, J; Ferencei, J; Finke, L; Fleischer, M; Fleischmann, P; Flucke, G; Fomenko, A; Foresti, I; Franke, G; Frisson, T; Gabathuler, E; Garutti, E; Gayler, J; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Glazov, A; Glushkov, I; Görlich, L; Goettlich, M; Gogitidze, N; Gorbounov, S; Goyon, C; Grab, C; Greenshaw, T; Gregori, M; Grell, B R; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Herrera-Corral, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Hreus, T; Hussain, S; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, A W; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Korbel, V; Kostka, P; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Kuckens, J; Landon, M P J; Lange, W; Lastoviicka, T; Lastoviicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; Liptaj, A; List, B; List, J; Lobodzinska, E; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mladenov, D; Mohamed, A; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nankov, K; Naroska, Beate; Naumann, T; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Papadopoulou, T D; Pascaud, C; Patel, G D; Peng, H; Pérez, E; Perez-Astudillo, D; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Portheault, B; Povh, B; Prideaux, P; Rahmat, A J; Raicevic, N; Reisert, B; Reimer, P; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rurikova, Z; Rusakov, S; Salvaire, F; Sankey, D P C; Sauvan, E; Schatzel, S; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schultz-Coulon, H C; Sedlak, K; Sefkow, F; Shaw-West, R N; Shevyakov, I; Shtarkov, L N; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Steder, M; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Sunar, D; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsakov, I; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, K; Urban, M; Usik, A; Utkin, D; Valkárová, A; Vallée, C; Van Mechelen, P; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vinokurova, S; Volchinski, V; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Wessels, M; Wessling, B; Wigmore, C; Wissing, C; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zhu, Y C; Zimmermann, J; Zimmermann, T; Zohrabyan, H; Zomer, F

    2006-01-01

    Data taken with positrons of different longitudinal polarisation states in collision with unpolarised protons at HERA are used to measure the total cross sections of the charged current process, e^+ p \\to \\bar{\

  16. Combined nonmetallic electronegativity equalisation and point-dipole interaction model for the frequency-dependent polarisability

    Science.gov (United States)

    Smalø, Hans S.; Åstrand, Per-Olof; Mayer, Alexandre

    2013-07-01

    A molecular mechanics model for the frequency-dependent polarisability is presented. It is a combination of a recent model for the frequency dependence in a charge-dipole model [Nanotechnology 19, 025203, 2008] and a nonmetallic modification of the electronegativity equalisation model rephrased as atom-atom charge-transfer terms [J. Chem. Phys. 131, 044101, 2009]. An accurate model for the frequency-dependent polarisability requires a more accurate partitioning into charge and dipole contributions than the static polarisability, which has resulted in several modifications of the charge-transfer model. Results are presented for hydrocarbons, including among others, alkanes, polyenes and aromatic systems. Although their responses to an electric field are quite different in terms of the importance of charge-transfer contributions, it is demonstrated that their frequency-dependent polarisabilities can be described with the same model and the same set of atom-type parameters.

  17. High resolution VLBI polarisation imaging of AGN with the Maximum Entropy Method

    CERN Document Server

    Coughlan, Colm P

    2016-01-01

    Radio polarisation images of the jets of Active Galactic Nuclei (AGN) can provide a deep insight into the launching and collimation mechanisms of relativistic jets. However, even at VLBI scales, resolution is often a limiting factor in the conclusions that can be drawn from observations. The Maximum Entropy Method (MEM) is a deconvolution algorithm that can outperform the more common CLEAN algorithm in many cases, particularly when investigating structures present on scales comparable to or smaller than the nominal beam size with "super-resolution". A new implementation of the MEM suitable for single- or multiple-wavelength VLBI polarisation observations has been developed and is described here. Monte Carlo simulations comparing the performances of CLEAN and MEM at reconstructing the properties of model images are presented; these demonstrate the enhanced reliability of MEM over CLEAN when images of the fractional polarisation and polarisation angle are constructed using convolving beams that are appreciably ...

  18. Peculiarities of spectral properties of a one-dimensional photonic crystal with an anisotropic defect layer of the nanocomposite with resonant dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Vetrov, S Ya; Timofeev, I V [L.V.Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Academgorodok, Krasnoyarsk (Russian Federation); Pankin, P S [Siberian Federal University, Krasnoyarsk (Russian Federation)

    2014-09-30

    We have studied the spectral properties of a one-dimensional photonic crystal with a structure defect that represents an anisotropic nanocomposite layer sandwiched between two multilayer dielectric mirrors. The nanocomposite consists of metallic nanoscale inclusions of orientationally ordered spheroidal shape, dispersed in a transparent matrix, and is characterised by an effective resonant permittivity. Each of the two orthogonal polarisations of probe radiation corresponds to a particular plasmon resonant frequency of the nanocomposite. The problem of calculating the transmittance spectrum of the waves with s- and p-polarisations for such structures is solved. Spectral manifestation of splitting of the defect mode depending on the structure parameters and volumetric fraction of the nanospheroids is studied. The essential dependence of the position of maxima of the defect modes in the bandgap of the photonic crystal and their splitting on the incidence angle, polarisation, and the ratio of lengths of the polar and equatorial semi-axes of the spheroidal nanoparticles is shown. (photonic crystals)

  19. An Evaluation of Polarisability Tensors of Arbitrarily Shaped Highly Conducting Bodies

    CERN Document Server

    Jelinek, L; Capek, M

    2016-01-01

    A full-wave numerical scheme of polarisability tensors evaluation is presented. The method accepts highly conducting bodies of arbitrary shape and explicitly accounts for the radiation as well as ohmic losses. The method is verified on canonical bodies with known polarisability tensors, such as a sphere and a cube, as well as on realistic scatterers. The theoretical developments are followed by a freely available code whose sole user input is the triangular mesh covering the surface of the body under consideration.

  20. On cloud ice induced absorption and polarisation effects in microwave limb sounding

    Directory of Open Access Journals (Sweden)

    P. Eriksson

    2011-06-01

    Full Text Available Microwave limb sounding in the presence of ice clouds was studied by detailed simulations, where clouds and other atmospheric variables varied in three dimensions and the full polarisation state was considered. Scattering particles were assumed to be horizontally aligned oblate spheroids with a size distribution parameterized in terms of temperature and ice water content. A general finding was that particle absorption is significant for limb sounding, which is in contrast to the down-looking case, where it is usually insignificant. Another general finding was that single scattering can be assumed for cloud optical paths below about 0.1, which is thus an important threshold with respect to the complexity and accuracy of retrieval algorithms. The representation of particle sizes during the retrieval is also discussed. Concerning polarisation, specific findings were as follows: Firstly, no significant degree of circular polarisation was found for the considered particle type. Secondly, for the ±45° polarisation components, differences of up to 4 K in brightness temperature were found, but differences were much smaller when single scattering conditions applied. Thirdly, the vertically polarised component has the smallest cloud extinction. An important goal of the study was to derive recommendations for future limb sounding instruments, particularly concerning their polarisation setup. If ice water content is among the retrieval targets (and not just trace gas mixing ratios, then the simulations show that it should be best to observe any of the ±45° and circularly polarised components. These pairs of orthogonal components also make it easier to combine information measured from different positions and with different polarisations.

  1. Applying cathodically polarised substrata to the restoration of a high value coral

    OpenAIRE

    Benedetti, Alessandro; Bramanti, Lorenzo; Tsounis, Gerogios; Faimali, Marco; Pavanello, Giovanni; Rossi, Sergio; Gili, Josep Maria; Santangelo, Giovanni

    2011-01-01

    Larval settlement of the high value red coral, Corallium rubrum, was studied on three different CaCO3 substrata, viz. lithogenic (marble), electro-accreted calcium carbonate in the presence and in the absence of cathodic polarisation. The last two substrata consisted of stainless steel plates galvanically coupled with Zn anodes. The electrochemical characterization of the settlement device was studied in order to investigate correlations between cathodic parameters (polarisation potential, cu...

  2. MEM imaging of multi-wavelength VLBA polarisation observations of Active Galactic Nuclei

    CERN Document Server

    Coughlan, Colm P

    2013-01-01

    We have developed a C++ implementation of the Maximum Entropy Method (MEM) suitable for deconvolving VLBI polarisation data. The first results of this implementation are presented and compared with CLEAN-based deconvolutions of the same data. We present Faraday rotation measure and intrinsic polarisation maps of AGN which have been made from MEM deconvolutions of multi-wavelength observations of Stokes parameters I, Q and U. The advantages of using MEM are demonstrated, in particular its enhanced resolution over the CLEAN algorithm.

  3. Broadband matching of dual-linear polarisation stacked probe-fed microstrip patch antenna

    DEFF Research Database (Denmark)

    Jaworski, G.; Krozer, Viktor

    2004-01-01

    A novel approach for impedance matching of probe-fed, stacked microstrip patch antenna elements is demonstrated. The matching structure is compact and enables more than doubling of the operational bandwidth. A circuit model for the feeding probes is developed and its impact on antenna impedance...

  4. The interaction of circularly polarised electromagnetic waves with a plasma; Interaction d'ondes electromagnetiques a polarisation circulaire avec un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, T.; Legardeur, R.; Slama, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The interaction of left and right handed circularly polarised waves with a plasma are studied. The individual trajectories of charges of both signs are traced with a analogical simulator. Applications to plasma heating and diagnostic are deduced. (author) [French] On etudie l'interaction des ondes a polarisation circulaire droite ou gauche avec un plasma. Les trajectoires individuelles des charges sont tracees a l'aide d'un dispositif analogique. On en deduit les applications au chauffage d'un plasma et a la mesure de ses parametres caracteristiques. (auteur)

  5. Recent advances in polarised {sup 3}He spin filters at the ILL

    Energy Technology Data Exchange (ETDEWEB)

    Petoukhov, A.K. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France)]. E-mail: petukhov@ill.fr; Andersen, K.H. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Jullien, D. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Babcock, E. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Chastagnier, J. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Chung, R. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Humblot, H. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Lelievre-Berna, E. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Tasset, F. [Institut Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Radu, F. [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Wolff, M. [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Zabel, H. [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2006-11-15

    We report the present status and recent advances made in polarised-{sup 3}He spin-filters at the ILL. The Tyrex filling station is working reliably and producing polarised {sup 3}He for neutron spin filters on a daily basis. The latest spin-filter cells have wall relaxation times between 200 and 400 h - the longest relaxation times yet achieved for valve-sealed cells. Recent results using {sup 3}He spin filters for reflectometry are presented and compared to the presently used supermirror-based polarisation analysers. By increasing the optical thickness of {sup 3}He gas, we move into a regime in which the neutron beam polarisation decays with a time constant of the order of a thousand hours and is thus negligible within the 24 h time scale of an experiment. We present the performance of a {sup 3}He spin flipper, which inverts the polarisation direction of the {sup 3}He nuclei by adiabatic fast passage with a polarisation loss of 10{sup -5} per flip. The development of in situ filling of the spin-filter cell via a capillary is described. This 'local filling' technique enables {sup 3}He spin filters to be used in inaccessible regions, such as inside large-detector vacuum tanks and in high-radiation environments.

  6. Adaptable radiative transfer innovations for submillimetre telescopes (ARTIST). Dust polarisation module (DustPol)

    Science.gov (United States)

    Padovani, M.; Brinch, C.; Girart, J. M.; Jørgensen, J. K.; Frau, P.; Hennebelle, P.; Kuiper, R.; Vlemmings, W. H. T.; Bertoldi, F.; Hogerheijde, M.; Juhasz, A.; Schaaf, R.

    2012-07-01

    We present a new publicly available tool (DustPol) aimed to model the polarised thermal dust emission. The module DustPol, which is publicly available, is part of the ARTIST (Adaptable Radiative Transfer Innovations for Submillimetre Telescopes) package, which also offers tools for modelling the polarisation of line emission together with a model library and a Python-based user interface. DustPol can easily manage analytical as well as pre-gridded models to generate synthetic maps of the Stokes I, Q, and U parameters. These maps are stored in FITS format which is straightforwardly read by the data reduction software used, e.g., by the Atacama Large Millimeter Array (ALMA). This turns DustPol into a powerful engine for the prediction of the expected polarisation features of a source observed with ALMA or the Planck satellite as well as for the interpretation of existing submillimetre observations obtained with other telescopes. DustPol allows the parameterisation of the maximum degree of polarisation and we find that, in a prestellar core, if there is depolarisation, this effect should happen at densities of 106 cm-3 or larger. We compare a model generated by DustPol with the observational polarisation data of the low-mass Class 0 object NGC 1333 IRAS 4A, finding that the total and the polarised emission are consistent.

  7. Polarisation of Social Inequalities in Disadvantaged Neighbourhoods of Bucharest Metropolis

    Directory of Open Access Journals (Sweden)

    ALINA T. CHICOŞ

    2013-01-01

    Full Text Available This paper gives an insight into the statistical interpretation of socio-spatial changes of Bucharest urban landscape in connection to the transformations of the urban planning visions across the last decades. Special emphasis is placed on the emergence of disadvantaged neighbourhoods which are defined by a clear homogenisation of certain social classes on a precarious housing infrastructure. This came as a result of a historical hierarchy of the urban social space. Moreover, Bucharest was shaped in relation to different socio-economic and socio-cultural policies that determined the creation of a polarisation between north and south or between centre and periphery which were subject to numerous socio-urban inversions during the communist and post-communist eras. Hence, life in a large metropolis is vulnerable to inequalities appearing within the urban pattern that intensifies, in some cases, towards residential segregation. The historical-geographical analysis of vectors behind clusters of sensitive areas in the 20th and 21st centuries strengthens the importance of social cohesion measures in the future urban policies and territorial planning.

  8. The RINGO2 and DIPOL Optical Polarisation Catalogue of Blazars

    CERN Document Server

    Jermak, H; Lindfors, E; Hovatta, T; Nilsson, K; Lamb, G P; Mundell, C; de Almeida, U Barres; Berdyugin, A; Kadenius, V; Reinthal, R; Takalo, L

    2016-01-01

    We present ~2000 polarimetric and ~3000 photometric observations of 15 gamma-ray bright blazars over a period of 936 days (11/10/2008 - 26/10/2012) using data from the Tuorla blazar monitoring program (KVA DIPOL) and Liverpool Telescope (LT) RINGO2 polarimeters (supplemented with data from SkyCamZ (LT) and Fermi-LAT gamma-ray data). In 11 out of 15 sources we identify a total of 19 electric vector position angle (EVPA) rotations and 95 flaring episodes. We group the sources into subclasses based on their broadband spectral characteristics and compare their observed optical and gamma-ray properties. We find that (1) the optical magnitude and gamma-ray flux are positively correlated, (2) EVPA rotations can occur in any blazar subclass, 4 sources show rotations that go in one direction and immediately rotate back, (3) we see no difference in the gamma-ray flaring rates in the sample; flares can occur during and outside of rotations with no preference for this behaviour, (4) the average degree of polarisation (Do...

  9. Integrins are required for cardioblast polarisation in Drosophila

    Directory of Open Access Journals (Sweden)

    Vanderploeg Jessica

    2012-02-01

    Full Text Available Abstract Background The formation of a tubular organ, such as the heart, requires the communication of positional and polarity signals between migratory cells. Key to this process is the establishment of a new luminal domain on the cell surface, generally from the apical domain of a migratory cell. This domain will also acquire basal properties, as it will produce a luminal extracellular matrix. Integrin receptors are the primary means of cell adhesion and adhesion signaling with the extracellular matrix. Here we characterise the requirement of Integrins in a genetic model of vasculogenesis, the formation of the heart in Drosophila. Results As with vertebrates, the Drosophila heart arises from lateral mesoderm that migrates medially to meet their contralateral partners, to then assemble a midline vessel. During migration, Integrins are among the first proteins restricted to the presumptive luminal domain of cardioblasts. Integrins are required for normal levels of leading edge membrane motility. Apical accumulation of Integrins is enhanced by Robo, and reciprocally, apicalisation of luminal factors like Slit and Robo requires Integrin function. Integrins may provide a template for the formation of a lumen by stabilising lumen factors like Robo. Subsequent to migration, Integrin is required for normal cardioblast alignment and lumen formation. This phenotype is most readily modified by other mutations that affect adhesion, such as Talin and extracellular matrix ligands. Conclusion Our findings reveal an instructive role for Integrins in communicating polarising information to cells during migration, and during transition to an epithelial tube structure.

  10. Polarised clathrin-mediated endocytosis of EGFR during chemotactic invasion.

    Science.gov (United States)

    Mutch, Laura Jane; Howden, Jake Davey; Jenner, Emma Poppy Louise; Poulter, Natalie Sarah; Rappoport, Joshua Zachary

    2014-06-01

    Directed cell migration is critical for numerous physiological processes including development and wound healing. However chemotaxis is also exploited during cancer progression. Recent reports have suggested links between vesicle trafficking pathways and directed cell migration. Very little is known about the potential roles of endocytosis pathways during metastasis. Therefore we performed a series of studies employing a previously characterised model for chemotactic invasion of cancer cells to assess specific hypotheses potentially linking endocytosis to directed cell migration. Our results demonstrate that clathrin-mediated endocytosis is indispensable for epidermal growth factor (EGF) directed chemotactic invasion of MDA-MB-231 cells. Conversely, caveolar endocytosis is not required in this mode of migration. We further found that chemoattractant receptor (EGFR) trafficking occurs by clathrin-mediated endocytosis and is polarised towards the front of migrating cells. However, we found no role for clathrin-mediated endocytosis in focal adhesion disassembly in this migration model. Thus, this study has characterised the role of endocytosis during chemotactic invasion and has identified functions mechanistically linking clathrin-mediated endocytosis to directed cell motility.

  11. Recent Advances for High-Efficiency Sources of Single Photons Based on Photonic Nanowires

    DEFF Research Database (Denmark)

    Gerard, J. M.; Claudon, J.; Munsch, M.

    2012-01-01

    Photonic nanowires have recently been used to tailor the spontaneous emission of embedded quantum dots, and to develop record efficiency single-photon sources. We will present recent developments in this field mainly 1) the observation of a strong inhibition of the spontaneous emission of quantum...... dots in ultrathin photonic wires 2) the control of the linear polarization of the single photons by photonic wires with an elliptical section, 3) the joint observation (unlike-cavity-based devices) of a record high efficiency and pure single photon emission process in a photonic wire single photon...

  12. Group Theory of Circular-Polarization Effects in Chiral Photonic Crystals with Four-Fold Rotation Axes, Applied to the Eight-Fold Intergrowth of Gyroid Nets

    CERN Document Server

    Saba, Matthias; Mecke, Klaus; Gu, Min; Schröder-Turk, Gerd E

    2013-01-01

    We use group or representation theory and scattering matrix calculations to derive analytical results for the band structure topology and the scattering parameters, applicable to any chiral photonic crystal with body-centered cubic symmetry I432 for circularly-polarised incident light. We demonstrate in particular that all bands along the cubic [100] direction can be identi?ed with the irreducible representations E+/-,A and B of the C4 point group. E+ and E- modes represent the only transmission channels for plane waves with wave vector along the ? line, and can be identi?ed as non-interacting transmission channels for right- (E-) and left-circularly polarised light (E+), respectively. Scattering matrix calculations provide explicit relationships for the transmission and reflectance amplitudes through a ?nite slab which guarantee equal transmission rates for both polarisations and vanishing ellipticity below a critical frequency, yet allowing for ?nite rotation of the polarisation plane. All results are veri?...

  13. Diffuse radio foregrounds: all-sky polarisation and anomalous microwave emission

    Science.gov (United States)

    Vidal Navarro, M. A.

    2014-07-01

    In this Thesis, we present work on the diffuse Galactic emission in the 23-43 GHz frequency range. We studied the polarised emission, which is dominated by synchrotron radiation at these frequencies. We also present work on the anomalous microwave emission (AME), both in total intensity and polarisation. These observations are useful to quantify the CMB foreground contribution and give us information about the ISM of our Galaxy. Polarisation observations are affected by a positive bias, particularly important in regions with low signal-to-noise ratio. We present a method to correct the bias in the case where the uncertainties in the Q, U Stokes parameters are not symmetric. We show that this method successfully corrects the polarisation maps, with a residual bias smaller than the random uncertainties on the maps, outperforming the methods that are previously described in the literature. We use the de-biasing method to set upper limits for the polarisation of AME in the ρ Ophiuchi and Perseus molecular clouds. In both clouds the AME polarisation fraction is found to be less than 2% at 23 GHz and33 GHz.We use data from the WMAP satellite at 23, 33 and 41 GHz to study the diffuse polarised emission over the entire sky. This emission is due to synchrotron radiation and it originates mostly from filamentary structures with well-ordered magnetic fields.We identify new filaments and studied their observational properties, such as polarisation spectral indices, polarisation fraction and Faraday rotation. We explore the link between the large scale filaments and the local ISM, using the model of an expanding shell in the vicinity of the Sun. We also quantify the level of contamination added by the diffuse filaments to the CMB E- and B-mode power spectra.The Q/U Imaging ExperimenT (QUIET) observed the polarised sky at 43 and 95 GHz, in order to measure the CMB spectra. We describe the instrument, the observations and data processing, focusing on two regions of the Galactic

  14. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  15. Two-photon contributions to the elastic electron-nucleon scattering in the Skyrme model; Zwei-Photon-Beitraege zur elastischen Elektron-Nukleon-Streuung im Skyrme-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Markus

    2008-09-23

    The electromagnetic form factors are crucial for our understanding of the inner structure of the proton. Recently it has become feasible to measure them by the use of polarisation transfer techniques in addition to the traditional Rosenbluth separation method. Thereby emerged an incompatibility of the results obtained by these two different experimental methods. It is commonly assumed that the discrepance is induced by higher order corrections to the cross section, especially through two-photon exchange processes. Unfortunately these processes cannot be calculated in a model independent manner because off-shell photon nucleon vertices arise. Effective chiral lagrangians contain already local two-photon couplings and therefore seem exceptionally well suited to study the anomaly contribution to the two-photon exchange. These couplings give two-photon exchange contributions that can be understood as the coupling of the nucleon to pions, decaying into two virtual photons. A particular contribution emerges from the chiral anomaly of QCD, that describes the two-photon decay of the neutral pion. The most important goal of this work is the calculation of the contribution arising from the anomaly to the elastic electron-proton scattering. The results are expected to be widely model independent since the anomaly directly reflects a QCD property. Based on the Skyrme model the protons are realized as soliton solutions in effective chiral theories. The next to leading order contribution to the cross section is given by the interference between the one- and two-photon exchange. The latter contains an ultraviolet divergence, which is renormalized by a local effective counterterm. This counterterm contributes to the width of the neutral pion decay which determines the finite part of the counterterm coefficient. The affect of the anomaly to the Rosenbluth separation of the electromagnetic form factors as well as the discrepance regarding the polarization measurements is extensively

  16. Time reversal constraint limits unidirectional photon emission in slow-light photonic crystals

    CERN Document Server

    Lang, Ben; Oulton, Ruth

    2016-01-01

    Photonic crystal waveguides are known to support C-points - point-like polarisation singularities with local chirality. Such points can couple with dipole-like emitters to produce highly directional emission, from which spin-photon entanglers can be built. Much is made of the promise of using slow-light modes to enhance this light-matter coupling. Here we explore the transition from travelling to standing waves for two different photonic crystal waveguide designs. We find that time-reversal symmetry and the reciprocal nature of light places constraints on using C-points in the slow-light regime. We observe two distinctly different mechanisms through which this condition is satisfied in the two waveguides. In the waveguide designs we consider, a modest group-velocity of $v_g \\approx c/10$ is found to be the optimum for slow-light coupling to the C-points.

  17. Non-linear imaging and characterization of atherosclerotic arterial tissue using combined two photon fluorescence, second-harmonic generation and CARS microscopy

    Science.gov (United States)

    Cicchi, Riccardo; Matthäus, Christian; Meyer, Tobias; Lattermann, Annika; Dietzek, Benjamin; Brehm, Bernhard R.; Popp, Jürgen; Pavone, Francesco S.

    2014-02-01

    Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires a morpho-functional approach. Multimodal non-linear microscopy has the potential to bridge this gap by providing morpho-functional information on the examined tissues in a label-free way. Here we employed multiple non-linear microscopy techniques, including CARS, TPF, and SHG to provide intrinsic optical contrast from various tissue components in both arterial wall and atherosclerotic plaques. CARS and TPF microscopy were used to respectively image lipid depositions within plaques and elastin in the arterial wall. Cholesterol deposition in the lumen and collagen in the arterial wall were selectively imaged by SHG microscopy and distinguished by forward-backward SHG ratio. Image pattern analysis allowed characterizing collagen organization in different tissue regions. Different values of fiber mean size, distribution and anisotropy are calculated for lumen and media prospectively allowing for automated classification of atherosclerotic lesions. The presented method represents a promising diagnostic tool for evaluating atherosclerotic tissue and has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.

  18. Microwave Photonics

    OpenAIRE

    Seeds, A.J.; Liu, C. P.; T. Ismail; Fice, M. J.; Pozzi, F; Steed, R. J.; Rouvalis, E.; Renaud, C.C.

    2010-01-01

    Microwave photonics is the use of photonic techniques for the generation, transmission, processing and reception of signals having spectral components at microwave frequencies. This tutorial reviews the technologies used and gives applications examples.

  19. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    A review is given of the space-time wave mechanics of single photons, a subject with an almost century long history. The Landau-Peierls photon wave function, which is related nonlocally to the electromagnetic field is first described, and thereafter the so-called energy wave function, based...... on the positive-frequency Riemann-Silberstein vectors, is discussed. Recent attempts to understand the birth process of a photon emerging from a single atom are summarized. The polychromatic photon concept is introduced, and it is indicated how the wave mechanics of polychromatic photons can be upgraded to wave...... train quantum electrodynamics. A brief description of particle (photon) position operators is given, and it is shown that photons usually are only algebraically confined in an emission process. Finally, it is demonstrated that the profile of the birth domain of a radio-frequency photon emitted...

  20. SU-E-T-525: Dosimetric Validation of the Algorithm Based on Linear Boltzmann Transport Equations for Photon 4MV Dose Calculation.

    Science.gov (United States)

    Sato, S; Miyabe, Y; Nakata, M; Tsuruta, Y; Nakamura, M; Mizowaki, T; Hiraoka, M

    2012-06-01

    To evaluate a dosimetric accuracy of AcurosXB dose calculation algorithm for 4 MV photon beam. Four MV beam (Clinac-6EX) and AAA and AcurosXB algorithms (pre-release version 11.0.03.) were used in this study. The differences of the calculation with AAA (EAAA) and AcurosXB (EAXB) to the measurement were evaluated in the depth doses to 25 cm depth and dose profiles within the water and slab phantoms (water, lung and bone equivalent). In addition, the clinical cases, including three whole breast plans and three head and neck IMRT plans, were evaluated. First the AAA plans were calculated, then AcurosXB plans were recalculated with dose-to-medium with identical beam setup and monitor units as in the AAA plan. In the water phantom study, the EAAA and EAXB were up to 2.2% and 1.5% in the depth doses for the open field (field size = 4 - 40cm square), respectively. Under the heterogeneity conditions, the EAAA and EAXB were less than 4.4% and 2.2% in lung region, and less than 12.5% and 6.3% in bone region, respectively. In the re-buildup region after passing through the lung phantom, the AAA overestimated the doses about 10%; however AcurosXB had good agreement with measurement within 3%. Dose profiles with AcurosXB were better agreement with measurement than AAA. In the clinical cases, the dose of the skin surface region with AcurosXB were higher than AAA by at least 10%, and the dose differences over 5% appeared in heterogeneous region. However, DVH shapes of each organ were similar between AAA and AcurosXB within 2%. In phantom study, AcurosXB had better agreement to measurement than AAA, especially in heterogeneous region and re-buildup region. In the clinical cases, there were large differences between AcurosXB and AAA in the surface region. Evaluation Agreement of non-clinical versions of Acuros XB with Varian Medical Systems. © 2012 American Association of Physicists in Medicine.

  1. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    on the positive-frequency Riemann-Silberstein vectors, is discussed. Recent attempts to understand the birth process of a photon emerging from a single atom are summarized. The polychromatic photon concept is introduced, and it is indicated how the wave mechanics of polychromatic photons can be upgraded to wave...

  2. Measurement of {lambda} polarisation observables at the COSY-TOF spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pizzolotto, C.

    2007-05-22

    In this work the (vector)pp {yields} pK{sup +}{lambda} reaction is studied. Data were taken at the COSY-TOF experiment in 2002 with a polarised proton beam at the momenta of 2.75 GeV/c and 2.95 GeV/c. The calculated beam polarisation was 39.8% and 61.9% respectively. The experimental setup covers the whole phase space of the reaction. The exclusive measurement allows the extraction of polarisation observables not only in the beam fragmentation region (x{sub F}>0), but also in the target fragmentation region (x{sub F} < 0). Samples of 11991 pK{sup +}{lambda} events at 2.75 GeV/c and of 19243 events at 2.95 GeV/c beam momentum have been reconstructed. The {lambda} polarisation, the {lambda} analysing power and the spin transfer coefficient were extracted. The {lambda} polarisation P{sub {lambda}} has a negative trend. The analysing power A{sup {lambda}}{sub y} and the spin transfer coefficient D{sub NN} are found to be compatible with zero. The measured spin transfer coefficient is in contradiction with the only result published up to now at comparable beam momenta. (orig.)

  3. A public code for general relativistic, polarised radiative transfer around spinning black holes

    Science.gov (United States)

    Dexter, Jason

    2016-10-01

    Ray tracing radiative transfer is a powerful method for comparing theoretical models of black hole accretion flows and jets with observations. We present a public code, GRTRANS, for carrying out such calculations in the Kerr metric, including the full treatment of polarised radiative transfer and parallel transport along geodesics. The code is written in FORTRAN 90 and efficiently parallelises with OPENMP, and the full code and several components have PYTHON interfaces. We describe several tests which are used for verifiying the code, and we compare the results for polarised thin accretion disc and semi-analytic jet problems with those from the literature as examples of its use. Along the way, we provide accurate fitting functions for polarised synchrotron emission and transfer coefficients from thermal and power-law distribution functions, and compare results from numerical integration and quadrature solutions of the polarised radiative transfer equations. We also show that all transfer coefficients can play an important role in predicted images and polarisation maps of the Galactic centre black hole, Sgr A*, at submillimetre wavelengths.

  4. On cloud ice induced absorption and polarisation effects in microwave limb sounding

    Directory of Open Access Journals (Sweden)

    P. Eriksson

    2011-03-01

    Full Text Available Detailed simulations of microwave limb sounding in the presence of ice clouds have been performed. It is clarified that, while particle absorption normally gives no significant change of the measured radiance for down-looking measurements, this is not the case for limb sounding. The particles were treated as horizontally aligned oblate spheroids and for this assumption on particle shape, and comparable situations, no significant degree of circular polarisation is generated. Differences between the brightness temperature of the ±45° polarisation components up to 4 K were found, but this difference appears to be small as long as single scattering conditions apply. The cloud extinction is the smallest for the vertically polarised component, but it should be more beneficial to observe any of the ±45° and circularly polarised components if ice water content is also a target of the retrievals. These latter pairs of orthogonal components also make it easier to combine information measured from different positions and with different polarisations. The results indicate that single scattering can be assumed for cloud optical thicknesses below about 0.1, which is thus an important threshold with respect to the complexity and accuracy of retrievals. The representation of particle sizes during the retrieval is discussed.

  5. Optical polarisation anisotropy in a-plane GaN/AlGaN multiple quantum well structures

    Energy Technology Data Exchange (ETDEWEB)

    Badcock, Tom J.; Dawson, Philip [School of Physics and Astronomy, Photon Science Institute, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom); Kappers, Menno J.; McAleese, Clifford; Hollander, Jonathan L.; Johnston, Carol F.; Sridhara Rao, Duggi V.; Sanchez, Ana M.; Humphreys, Colin J. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2009-06-15

    In this paper we report on the optical properties of a series of a-plane GaN/AlGaN multiple quantum well structures of varying well width. The low temperature photoluminescence spectrum of each structure is characterised by two distinct emission bands, both of which shift to higher energy with decreasing well thickness. The origin of the lower energy emission band is attributed to the recombination of carriers trapped in regions of the quantum wells intersected by basal plane stacking faults. The higher energy feature is assigned to localised exciton recombination at well width fluctuations. We have used photoluminescence excitation spectroscopy to reveal details of the bandstructure of the quantum wells. Excitation with unpolarised light resulted in the observation of exciton transitions associated with the n = 1 and n = 2 electron sub-bands. For linearly polarised (E perpendicular to c and E parallel c) excitation, both the transitions observed with unpolarised light were shown to consist of overlapping transitions involving heavy and light hole like valence subbands. Their observed polarisation anisotropy was attributed to anisotropic biaxial compressive strain in the GaN film. As well as the exciton transitions we were also able to resolve well defined continuum edges in some of the excitation spectra. This enabled us to estimate the exciton binding energy of the n=1 heavy and light hole states for quantum wells of differing width. Values were found to lie in the range of 38 to 76 {+-}5 meV. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Linear/circular spectropolarimetry of diffuse interstellar bands

    CERN Document Server

    Cox, N L J; Foing, B H; d'Hendecourt, L; Salama, F; Sarre, P J

    2011-01-01

    Context. The identification of the carriers of diffuse interstellar bands (DIBs) remains one of the long-standing mysteries in astronomy. The detection of a polarisation signal in a DIB profile can be used to distinguish between a dust or gas-phase carrier. The polarisation profile can give additional information on the grain or molecular properties of the absorber. In order to detect and measure the linear and circular polarisation of the DIBs we observed reddened lines of sight showing continuum polarisation. For this study we selected two stars HD 197770 and HD 194279. We used high-resolution (R~64.000) spectropolarimetry in the wavelength range from 3700 to 10480 Angstrom with the ESPaDOnS echelle spectrograph mounted at the CFHT. Results. High S/N and high resolution Stokes V (circular), Q and U (linear) spectra were obtained. We constrained upper limits by a factor of 10 for previously observed DIBs. Furthermore, we analysed ~30 additional DIBs for which no spectropolarimetry data has been obtained befo...

  7. Alignment measurements using one, two or three photons

    Science.gov (United States)

    Docker, M. P.

    1988-10-01

    The classical and quantum mechanical theory needed to extract the alignment parameters of a molecular angular momentum distribution from one-, two- and three-photon measurements is discussed. The work of Case, McClelland and Herschbach using the time evolution of the state multipoles of a joint molecule/photon density matrix is extended to include non-resonant multiphoton transitions and new results applicable to 2+1 laser-induced fluorescence are presented. A number of experimentally useful special cases of the one-, two- and three-photon results are derived (including the effect of unresolved emission and of parallel polarised photons), and the high- Ji limiting classical coefficients for population and alignment terms are tabulated for a range of geometries.

  8. Strain-optic active control for quantum integrated photonics

    CERN Document Server

    Humphreys, Peter C; Spring, Justin B; Moore, Merritt; Salter, Patrick S; Booth, Martin J; Kolthammer, W Steven; Walmsley, Ian A

    2014-01-01

    We present a practical method for active phase control on a photonic chip that has immediate applications in quantum photonics. Our approach uses strain-optic modification of the refractive index of individual waveguides, effected by a millimeter-scale mechanical actuator. The resulting phase change of propagating optical fields is rapid and polarization-dependent, enabling quantum applications that require active control and polarization encoding. We demonstrate strain-optic control of non-classical states of light in silica, showing the generation of 2-photon polarisation N00N states by manipulating Hong-Ou-Mandel interference. We also demonstrate switching times of a few microseconds, which are sufficient for silica-based feed-forward control of photonic quantum states.

  9. Crystal growth, perfection, linear and nonlinear optical, photoconductivity, dielectric, thermal and laser damage threshold properties of 4-methylimidazolium picrate: an interesting organic crystal for photonic and optoelectronic devices

    Science.gov (United States)

    Rajesh, K.; Arun, A.; Mani, A.; Praveen Kumar, P.

    2016-10-01

    The 4-methylimidazolium picrate has been synthesized and characterized successfully. Single and powder x-ray diffraction studies were conducted which confirmed the crystal structure, and the value of the strain was calculated. The crystal perfection was determined by a HRXR diffractometer. The transmission spectrum exhibited a better transmittance of the crystal in the entire visible region with a lower cut-off wavelength of 209 nm. The linear absorption value was calculated by the optical limiting method. A birefringence study was also carried out. Second and third order nonlinear optical properties of the crystal were found by second harmonic generation and the z-scan technique. The crystals were also characterized by dielectric measurement and a photoconductivity analyzer to determine the dielectric property and the optical conductivity of the crystal. The laser damage threshold activity of the grown crystal was studied by a Q-switched Nd:YAG laser beam. Thermal studies established that the compound did not undergo a phase transition and was stable up to 240 °C.

  10. Using of beam spoilers in linear accelerators with photons of 10 MV; Empleo de degradadores del haz en aceleradores lineales con fotones de 10 MV

    Energy Technology Data Exchange (ETDEWEB)

    Sansogne, R.; Palacios, V.; Arbiser, S. [Vidt Centro Medico- CETRO. Vidt 1924- (1428) Buenos Aires (Argentina)

    1998-12-31

    This work come along of the necessity to utilize an unique High-Energy Electron Linear Accelerator (10 MV) for radiant treatments which require higher doses in the surface levels of tissue. It is analyzed the interposition of acrylic degraders (spoilers) in the beam, especially for opposed and parallel fields in the cases of head and neck. It was analyzed the possible combinations of the following parameters: 1) Field sizes defined at isocenter (100 cm) 6 x 6 cm{sup 2}, 8 x 8 cm{sup 2} and 10 x 10 cm{sup 2} ; 2) Surface-spoiler distance (DSS) of 4, 7 and 10 cm; 3) Spoilers with different thickness 1.1 and 1.5 cm. It was observed a displacement of the maximum dose toward the surface, and an increase in the percentile doses in the build-up zone when the spoiler is nearing and/or increasing its thickness. It is verified that the use of spoilers, support the symmetry and plane of the beam inside of the clinically acceptable margins. When the results obtained are analyzed then it is proposed as a calculation method to incorporate an attenuation factor. (Author)

  11. Measurement of polarization observables in the reaction {gamma}p{yields} p{pi}{sup 0}{pi}{sup 0} using linearly polarized photons with the CBELSA/TAPS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sokhoyan, Vahe

    2012-07-27

    The spectrum and the properties of baryon resonances can be studied using photons with energies appropriate to excite baryonic states. Double meson photoproduction allows access to cascading resonance decays via other excited states. Also, at higher energies the importance of the double meson photoproduction increases due to higher cross-sections in comparison to single meson photoproduction. To study baryon resonances, the measurement of polarization observables as well as the measurement of differential cross-sections plays a very important role. In this work the three-body polarization observables I{sup s}, I{sup c} and the respective twobody asymmetry {Sigma} were measured for the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0} in an incoming photon energy range of E{sub {gamma}} = 970 - 1650 MeV. The data were acquired with the CBELSA/TAPS experiment located at the ELSA accelerator in Bonn, using a linearly polarized photon beam impinging on a liquid hydrogen target. The observables I{sup s} and I{sup c} which occur in two-meson final states are measured for the first time in the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0}. The corresponding two-body asymmetry {Sigma} is measured in an extended energy range in comparison to already existing data. A comparison with theoretical models shows that the polarization observables provide valuable input to study resonance contributions and their decay modes. The D{sub 33}(1700) {yields} {Delta}{pi} decay is studied based on the comparison of the Bonn-Gatchina Partial Wave Analysis (PWA) predictions with the data. Furthermore, a comparison of the data with the Bonn-Gatchina PWA and the Fix isobar model predictions allows to distinguish between these two models. Additionally, band-like structures and peaks are observed in the mass ranges of {Delta}(1232), D{sub 13}(1520), F{sub 15}(1680), f{sub 0}(980) and f{sub 2}(1270) in the according Dalitz plots and invariant mass distributions. The contributions of these

  12. A 1.5k x 1.5k class photon counting HgCdTe linear avalanche photo-diode array for low background space astronomy in the 1-5micron infrared

    Science.gov (United States)

    Hall, Donald

    Under a current award, NASA NNX 13AC13G "EXTENDING THE ASTRONOMICAL APPLICATION OF PHOTON COUNTING HgCdTe LINEAR AVALANCHE PHOTODIODE ARRAYS TO LOW BACKGROUND SPACE OBSERVATIONS" UH has used Selex SAPHIRA 320 x 256 MOVPE L-APD HgCdTe arrays developed for Adaptive Optics (AO) wavefront (WF) sensing to investigate the potential of this technology for low background space astronomy applications. After suppressing readout integrated circuit (ROIC) glow, we have placed upper limits on gain normalized dark current of 0.01 e-/sec at up to 8 volts avalanche bias, corresponding to avalanche gain of 5, and have operated with avalanche gains of up to several hundred at higher bias. We have also demonstrated detection of individual photon events. The proposed investigation would scale the format to 1536 x 1536 at 12um (the largest achievable in a standard reticule without requiring stitching) while incorporating reference pixels required at these low dark current levels. The primary objective is to develop, produce and characterize a 1.5k x 1.5k at 12um pitch MOVPE HgCdTe L-APD array, with nearly 30 times the pixel count of the 320 x 256 SAPHIRA, optimized for low background space astronomy. This will involve: 1) Selex design of a 1.5k x 1.5k at 12um pitch ROIC optimized for low background operation, silicon wafer fabrication at the German XFab foundry in 0.35 um 3V3 process and dicing/test at Selex, 2) provision by GL Scientific of a 3-side close-buttable carrier building from the heritage of the HAWAII xRG family, 3) Selex development and fabrication of 1.5k x 1.5k at 12 um pitch MOVPE HgCdTe L-APD detector arrays optimized for low background applications, 4) hybridization, packaging into a sensor chip assembly (SCA) with initial characterization by Selex and, 5) comprehensive characterization of low background performance, both in the laboratory and at ground based telescopes, by UH. The ultimate goal is to produce and eventually market a large format array, the L

  13. Limits Due to Instrumental Polarisation in CMB Experiments at Microwave Wavelengths

    CERN Document Server

    Carretti, E; Cortiglioni, S; Monari, J; Orsini, M

    2001-01-01

    An extended analysis of some instrumental polarisation sources has been done, as a consequence of the renewed interest in extremely sensitive polarisation measurements stimulated by Cosmic Microwave Background experiments. The case of correlation polarimeters, being them more suitable than other configurations, has been studied in detail and the algorithm has been derived to calculate their intrinsic sensitivity limit due to device characteristics as well as to the operating environment. The atmosphere emission, even though totally unpolarised, has been recognized to be the most important source of sensitivity degradation for ground based experiments. This happens through receiver component losses (mainly in the OMT), which generate instrumental polarisation in genuinely uncorrelated signals. The relevant result is that, also in best conditions (cfr. Antarctica), integration times longer than ~40s are not allowed on ground without modulation techniques. Finally, basic rules to estimate the maximum modulation ...

  14. Temperature dependent two-phase behaviour of magnetisation and spin polarisation in NiPt

    Energy Technology Data Exchange (ETDEWEB)

    Schaefers, Markus; Thomas, Andy; Reiss, Guenter [Bielefeld University, Universitaetsstrasse 25, D-33615 Bielefeld (Germany)

    2007-07-01

    We investigated the temperature dependent behaviour of magnetisation and spin polarisation in NiCu and NiPt alloys. The advantage of these alloys is the reduced Curie temperature compared with pure Nickel. The whole range of magnetisation is accessible in experiment for these alloys. Magnetic tunnel junctions with these alloys as free electrode were prepared by dc-magnetron sputtering in an UHV system with a base pressure of 1 . 10{sup -7} mbar and argon ion beam etching. TMR ratio was measured temperature dependent with a dc 2-point method. Spin polarisation was calculated by Julliere's formula. Magnetisation was measured with a SQUID for different temperatures. The NiPt alloy showed a maximum for in-plane magnetisation and spin polarisation at about 190 K. There are indications for a perpendicular magnetic anisotropy at low temperatures in the NiPt alloy.

  15. Measurement of $\\tau$ Polarisation in $Z/\\gamma^*\\rightarrow\\tau\\tau$ Decays with the ATLAS Detector

    CERN Document Server

    Winter, Benedict Tobias; The ATLAS collaboration

    2017-01-01

    A measurement of the $\\tau$ polarisation in $Z/\\gamma^*\\rightarrow\\tau\\tau$ decays is presented. The analysis is based on the $20.2$ fb$^{-1}$ of proton$-$proton collision data collected at a centre-of-mass energy of $\\sqrt{s}=8$ TeV by the ATLAS experiment at the CERN Large Hadron Collider in 2012. Events with one leptonic $\\tau$ decay and one hadronic $\\tau$ decay with a single charged particle in the final state are selected. The $\\tau$ polarisation is measured using the kinematic configuration of the hadronic decay. A polarisation of $P_\\tau~=-0.14\\;\\pm~0.02\\;(\\textrm{stat})\\;\\pm~0.04\\;(\\textrm{syst})$ is measured in the mass range $66 < m_{Z/\\gamma^*} < 116$ GeV. It agrees with the Standard Model prediction of $P_\\tau~=-0.1517\\pm0.0014\\;(\\textrm{stat})\\pm0.0013\\;(\\textrm{syst})$.

  16. Sensitivity analysis the influence of the average energy and FWHM of the initial fluence electrons in the determination of a spectrum of photons Bremsstrahlung of a linear accelerator; Analisis de sensibilidad de la influencia de la energia media y FWHM de la fluencia inicial de electrones en la determinacion de un espectro de fotones Bremsstrahlung de accelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Justo, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.

    2011-07-01

    The main objective of this work is to study the effects of the initial beam characteristics of electrons in the absorbed dose distribution calculated by Monte Carlo for a photons beam of 6 MeV emitted by a medical linear accelerator.

  17. Results from the Solar Hidden Photon Search (SHIPS)

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Matthias [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany); Knabbe, Ernst-Axel; Lindner, Axel [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany); Redondo, Javier [Departamento de Física Teórica, Universidad de Zaragoza, Pedro Cerbuna 12, E-50009, Zaragoza (Spain); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Ringwald, Andreas [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany); Schneide, Magnus; Susol, Jaroslaw; Wiedemann, Günter [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2015-08-07

    We present the results of a search for transversely polarised hidden photons (HPs) with ∼3 eV energies emitted from the Sun. These hypothetical particles, known also as paraphotons or dark sector photons, are theoretically well motivated for example by string theory inspired extensions of the Standard Model. Solar HPs of sub-eV mass can convert into photons of the same energy (photon ↔ HP oscillations are similar to neutrino flavour oscillations). At SHIPS this would take place inside a long light-tight high-vacuum tube, which tracks the Sun. The generated photons would then be focused into a low-noise photomultiplier at the far end of the tube. Our analysis of 330 h of data (and 330 h of background characterisation) reveals no signal of photons from solar hidden photon conversion. We estimate the rate of newly generated photons due to this conversion to be smaller than 25 mHz/m{sup 2} at the 95% C.L. Using this and a recent model of solar HP emission, we set stringent constraints on χ, the coupling constant between HPs and photons, as a function of the HP mass.

  18. Results from the solar hidden photon search (SHIPS)

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Matthias; Schneide, Magnus; Susol, Jaroslaw; Wiedemann, Guenter [Hamburg Univ. (Germany). Sternwarte; Knabbe, Ernst-Axel; Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Redondo, Javier [Zaragoza Univ. (Spain). Dept. de Fisica Teorica; Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-02-15

    We present the results of a search for transversely polarised hidden photons (HPs) with ∝3 eV energies emitted from the Sun. These hypothetical particles, known also as paraphotons or dark sector photons, are theoretically well motivated for example by string theory inspired extensions of the Standard Model. Solar HPs of sub-eV mass can convert into photons of the same energy (photon<->HP oscillations are similar to neutrino flavour oscillations). At SHIPS this would take place inside a long light-tight high-vacuum tube, which tracks the Sun. The generated photons would then be focused into a low-noise photomultiplier at the far end of the tube. Our analysis of 330 h of data (and 330 h of background characterisation) reveals no signal of photons from solar hidden photon conversion. We estimate the rate of newly generated photons due to this conversion to be smaller than 25 mHz/m{sup 2} at the 95%C.L. Using this and a recent model of solar HP emission, we set stringent constraints on χ, the coupling constant between HPs and photons, as a function of the HP mass.

  19. Investigation of stress-induced birefringence of tissue determined with polarisation sensitive optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Karnowski, Karol; Li, Qingyun; Villiger, Martin; Sampson, David D.

    2017-02-01

    Polarisation sensitive optical coherence tomography (PS-OCT) offers additional intrinsic contrast to probe differences between healthy tissue and cancer that are often barely visible due to limited scattering contrast in an OCT image. PS-OCT reconstructs tissue birefringence from phase-sensitive measurements of orthogonal polarisation components of backscattering. In material science, polarisation has been used to study stress distribution, including the birefringence induced by stress in an otherwise isotropic material. Similar effects in biological tissues have not been well studied yet; however, may have application to tissues subjected to stress, e.g., tendons, muscles, lens, cornea or airway smooth muscle (ASM). The objective of this work is to explore stress-induced birefringence in tissue. We employ an advanced swept source-based PS-OCT system capable of measurement of tissue local polarisation properties. The sample in both cases is illuminated with orthogonal, passively depth-encoded polarisation states. Light returning from the tissue is detected via a polarisation-diversity detection module and a Mueller formalism is used to reconstruct polarisation properties (including retardation, diattenuation, and depolarisation) of the tissue. In this study, we demonstrate the measurement of stress-induced birefringence in phantoms and in soft tissues with polarisation sensitive optical coherence tomography.

  20. Design of an electrically small circularly polarised turnstile antenna and its application to near-field wireless power transfer

    DEFF Research Database (Denmark)

    Yoon, Ick-Jae; Ling, Hao

    2014-01-01

    numerical search is used to determine the optimal antenna dimensions to achieve good axial ratio and impedance matching. The resulting design has a kr of 0.67 and shows good circular polarisation characteristic with a 3% axial ratio bandwidth. The designed antenna is fabricated and its circular polarisation...

  1. Polarisation of valence and non-strange sea quarks in the nucleon from semi-inclusive spin asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    The Spin Muon Collaboration

    1996-01-01

    Semi-inclusive spin asymmetries for positively and negatively charged hadrons measured in deep inelastic scattering of polarised muons on polarised protons and deuterons are presented. The x-dependent spin distributions for up and down valence quarks and for non-strange sea quarks are determined. (author). Submitted to Physics Letters, B (NL); 18 refs.

  2. Planar photonic crystal waveguides in silicon oxynitride

    DEFF Research Database (Denmark)

    Liu, Haoling; Frandsen, Lars Hagedorn; Borel, Peter Ingo;

    Most work on planar photonic crystals has been performed on structures based on semiconducting crystals such as Si and III-V compounds. Due to the high index contrast between the host material and the air holes (e.g., Si has n = 3.5), these structures exhibit a large photonic band gap. However......ON glasses with different indices between 1.46 and 1.77 and we are currently fabricating photonic crystals in SiON on a silica buffer layer on Si. Simulations show that a complete band gap can indeed be created for TE-polarised light in the SiON structures, making them promising candidates for new photonic......, at visible wavelengths they absorb light very strongly. In contrary, silicon oxynitride (SiON) glasses offer high transparency down to blue and ultraviolet wavelengths. Thus, SiON photonic crystal waveguides can open for new possibilities, e.g., within sensing and life sciences. We have fabricated Si...

  3. Polarisation Control of DFB Fibre Laser Using UV-Induced Birefringent Phase-Shift

    DEFF Research Database (Denmark)

    Philipsen, Jacob Lundgreen; Lauridsen, Vibeke Claudia; Berendt, Martin Ole;

    1998-01-01

    The polarisation properties of a distributed feedback (DFB) fibre laser are investigated experimentally. A birefringent phase-shift is induced by side illumination of the centre part of the lasing structure with ultraviolet (UV) light and it is experimentally shown that the birefringence of the p......The polarisation properties of a distributed feedback (DFB) fibre laser are investigated experimentally. A birefringent phase-shift is induced by side illumination of the centre part of the lasing structure with ultraviolet (UV) light and it is experimentally shown that the birefringence...

  4. Magneto-optical trap formed by elliptically polarised light waves for Mg atoms

    Science.gov (United States)

    Prudnikov, O. N.; Brazhnikov, D. V.; Taichenachev, A. V.; Yudin, V. I.; Goncharov, A. N.

    2016-07-01

    We consider a magneto-optical trap (MOT) formed by elliptically polarised waves for 24Mg atoms on a closed optical 3P2 → 3D3 (λ = 383.8 nm) transition in the ɛ - θ - ɛ¯ configuration of the field. Compared with a known MOT formed by circularly polarised waves (σ+ - σ- configuration), the suggested configuration of the trap formed by fields of ɛ - θ - ɛ¯ configuration allows deeper sub-Doppler cooling of trapped 24Mg atoms, which cannot be implemented in a conventional trap formed by fields of σ+ - σ- configuration.

  5. Polarised Small Angle Neutron Scattering study of microstructural radiation damage in steels for nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Coppola, R. [ENEA-Casaccia, FIS, CP 2400, 00100 Rome (Italy)]. E-mail: coppolar@casaccia.enea.it; Lindau, R. [Forschungszentrum Karlsruhe, IMF, P.O. Box 3640, D-76021 Karlsruhe (Germany); Magnani, M. [ENEA-Clementel, FIS, V. Don Fiammelli 2, 40129 Bologna (Italy); May, R.P. [Institut Max Von Laue-Paul Langevin, 6 rue Jules Horowitz, F-38042 Grenoble Cedex (France); Moeslang, A. [Forschungszentrum Karlsruhe, IMF, P.O. Box 3640, D-76021 Karlsruhe (Germany); Valli, M. [ENEA-Clementel, FIS, V. Don Fiammelli 2, 40129 Bologna (Italy)

    2006-11-15

    Polarised SANS has been used to investigate two martensitic steels for fusion reactor technology (MANET and OPTIFER, differing in their initial Cr content), before and after neutron irradiation. The measurements were carried out at the instrument D22 of the ILL, Grenoble, using an ad hoc polarised beam set-up. The results show both the occurrence of Cr redistribution phenomena with correlated changes in the composition of the precipitate phases, and the growth of non-magnetic defects (possibly microvoids), depending on the irradiation conditions and on the original steel composition.

  6. Polarised Small Angle Neutron Scattering study of microstructural radiation damage in steels for nuclear applications

    Science.gov (United States)

    Coppola, R.; Lindau, R.; Magnani, M.; May, R. P.; Möslang, A.; Valli, M.

    2006-11-01

    Polarised SANS has been used to investigate two martensitic steels for fusion reactor technology (MANET and OPTIFER, differing in their initial Cr content), before and after neutron irradiation. The measurements were carried out at the instrument D22 of the ILL, Grenoble, using an ad hoc polarised beam set-up. The results show both the occurrence of Cr redistribution phenomena with correlated changes in the composition of the precipitate phases, and the growth of non-magnetic defects (possibly microvoids), depending on the irradiation conditions and on the original steel composition.

  7. Radially-polarised beam amplification in an Yb:YAG thin-slab architecture (Conference Presentation)

    Science.gov (United States)

    Smith, Callum R.; Beecher, Stephen J.; Mackenzie, Jacob I.; Clarkson, W. Andrew

    2017-03-01

    Radially-polarised beams are attracting growing interest owing to their unique properties and numerous applications. Power-scaling whilst preserving the polarisation-purity of radially-polarised beams is challenging, with efforts predominantly focused on cylindrically-symmetric systems. We explore an alternative strategy for power-scaling radially-polarised beams using a thin-slab amplifier geometry, which, to the best of our knowledge, has not been previously investigated. We show that very high radial polarisation-purity can be maintained in an architecture that can be operated at high powers. A radially-polarised seed-source was constructed using an Yb:YAG rod in a plane-parallel configuration, pumped by a capillary delivery-fiber which provided effective overlap with the LG01 mode. By tuning the cavity length and utilising thermally-induced birefringence, a robust multi-Watt LG01 mode was generated with an excellent radial polarisation-purity of 15dB and good beam quality M2=2.2. The Yb:YAG slab was pumped by a diode-bar producing a highly-elongated inversion region. The seed was amplified in a double-pass configuration, using a cylindrical lens to spatially-match the inversion. The output beam was re-collimated by the cylindrical lens, and compensation for the Gouy phase-shift was made using a half-waveplate. At 50W of incident pump power we obtained a small-signal gain of 7.5dB and a power gain of 4.5dB for 1.45W seed power. At maximum pump power the radial polarisation-purity was maintained at 15dB, and the beam quality only degraded slightly to M2=2.3. Further optimisation of slab design and pump geometry will be discussed in addition to power-scaling the system to higher output powers necessary for a range of applications.

  8. Polarised spectroscopy of individual single-wall nanotubes: Radial-breathing mode study

    Science.gov (United States)

    Azoulay, J.; Débarre, A.; Richard, A.; Tchénio, P.; Bandow, S.; Iijima, S.

    2001-02-01

    Polarised Raman spectroscopy is performed in a randomly distributed single-wall carbon tube (SWNT) sample at the scale of an individual single-wall nanotube. A detailed analysis in the radial-breathing mode (RBM) domain is presented. Selection of either a single tiny rope of SWNTs or of a single SWNT results from the conjugated high spatial selection of confocal microscopy, surface-enhanced Raman spectroscopy (SERS) and sample dilution. The drastic modifications observed in the low-frequency Raman spectra as a function of the polarisation configuration confirm the theoretical results.

  9. Measuring the corrosion rate of steel in concrete – effect of measurement technique, polarisation time and current

    DEFF Research Database (Denmark)

    Nygaard, Peter Vagn; Geiker, Mette Rica

    2012-01-01

    Both on-site investigations and laboratory studies have shown that different corrosion rates are obtained when different commercially available corrosion rate instruments are used. The different electrochemical techniques and the measurement parameters used, i.e. polarisation current and time......, are in some studies considered the main reasons for the variations. This paper presents an experimental study on the quantitative effect of polarisation time and current on the measured polarisation resistance – and thus the corrosion current density – of passively and actively corroding steel. Two...... electrochemical techniques often used in instruments for on-site corrosion rate measurements are investigated. On passively corroding reinforcement the measured polarisation resistance was for both techniques found to be highly affected by the polarisation time and current and no plateaus at either short or long...

  10. From neutrino physics to beam polarisation. A high precision story at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Vormwald, Benedikt

    2014-03-15

    In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ{sub 23}, which is accessible via the ratio of the neutralino branching ratios BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ{sup 0}{sub 1}-pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ{sup 0}{sub 1} decays, we find that the χ{sup 0}{sub 1} mass can be reconstructed with an uncertainty of δ(m{sub χ{sup 0}{sub 1}})=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb{sup -1}. The ratio of branching ratios can be determined to a precision of δ(BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential

  11. Photonic Hypercrystals

    Directory of Open Access Journals (Sweden)

    Evgenii E. Narimanov

    2014-10-01

    Full Text Available We introduce a new “universality class” of artificial optical media—photonic hypercrystals. These hyperbolic metamaterials, with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hypercrystal possess the properties of both the optical Tamm states in photonic crystals and surface-plasmon polaritons at the metal-dielectric interface.

  12. Photonic Lantern

    CERN Document Server

    Leon-Saval, Sergio; Bland-Hawthorn, Joss

    2015-01-01

    Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus, enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail.

  13. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  14. Photoproduction of Λ and Σ0 hyperons using linearly polarized photons

    Energy Technology Data Exchange (ETDEWEB)

    Paterson, C. A.; Ireland, D. G.; Livingston, K.; McKinnon, B.; Adhikari, K. P.; Adikaram, D.; Akbar, Z.; Amaryan, M.; Anefalos Pereira, S.; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chetry, T.; Ciullo, G.; Clark, L.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crede, V.; D' Angelo, A.; De Vita, R.; Deur, A.; Djalali, C.; Dugger, M.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Fanchini, E.; Fedotov, G.; Filippi, A.; Fleming, J. A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Gleason, C.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Joo, K.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Lanza, L.; Lenisa, P.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; Mayer, C. A.; McCracken, M. E.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Net, L. A.; Ni, A.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A. I.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Pisano, S.; Pogorelko, O.; Price, J. W.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Ripani, M.; Ritchie, B. G.; Rizzo, A.; Rosner, G.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Torayev, B.; Tucker, R.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Zachariou, N.; Zana, L.; Zhang, J.; Zonta, I.

    2016-06-01

    Background: Measurements of polarization observables for the reactions (gamma) over right arrowp -> K+ Lambda and (gamma) over right arrowp -> K+ Sigma(0) have been performed. This is part of a program of measurements designed to study the spectrum of baryon resonances in particular, and nonperturbative QCD in general. Purpose: The accurate measurement of several polarization observables provides tight constraints for phenomenological fits, which allow the study of strangeness in nucleon and nuclear systems. Beam-recoil observables for the (gamma) over right arrowp -> K+ Sigma(0) reaction have not been reported before now. Method: Themeasurements were carried out using linearly polarized photon beams incident on a liquid hydrogen target, and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71 < W < 2.19 GeV, with an angular range -0.75 < cos theta(K)* < +0.85. Results: The observables extracted for both reactions are beam asymmetry Sigma, target asymmetry T, and the beam-recoil double polarization observables O-x and O-z. Conclusions: Comparison with theoretical fits indicates that, in the regions where no previous data existed, the new data contain significant new information, and strengthen the evidence for the set of resonances used in the latest Bonn-Gatchina fit.

  15. T helper cell polarisation as a measure of the maturation of the immune response

    NARCIS (Netherlands)

    Cameron, S.B.; Stolte, H.H.; Chow, A.W.; Savelkoul, H.F.J.

    2003-01-01

    BACKGROUND: T helper cell polarisation is important under chronic immune stimulatory conditions and drives the type of the evolving immune response. Mice treated with superantigens in vivo display strong effects on T-h subset differentiation. The aim of the study was to detect the intrinsic capacity

  16. Comparison between time-and frequency-domain induced polarisation parameters

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available of mineralised rocks and of the contrast between different rock types. It is further shown that a multi-frequency (spectral) approach can be used to avoid this pitfall; similarly, the calculation of different time-domain induced polarisation (IP) parameters...

  17. Coherent propagation of a short polarised radiation pulse in a one-dimensional resonance Bragg grating

    NARCIS (Netherlands)

    Maimistov, A. I.; Polikarpov, V. V.

    2006-01-01

    The propagation of an optical ultrashort pulse in a resonance Bragg grating is considered taking into account the polarisation of electromagnetic radiation. It is assumed that the grating is formed by thin films containing two-level atoms with the triply degenerate upper energy level. The system of

  18. Evidence of polarisation in the prompt gamma-ray emission from GRB 930131 and GRB 960924

    CERN Document Server

    Willis, D R; Bird, A J; Clark, D J; Dean, A J; McConnell, M L; Moran, L; Shaw, S E; Sguera, V

    2005-01-01

    The true nature of the progenitor to GRBs remains elusive; one characteristic that would constrain our understanding of the GRB mechanism considerably is gamma-ray polarimetry measurements of the initial burst flux. We present a method that interprets the prompt GRB flux as it Compton scatters off the Earth's atmosphere, based on detailed modelling of both the Earth's atmosphere and the orbiting detectors. The BATSE mission aboard the \\textit{CGRO} monitored the whole sky in the 20 keV - 1 MeV energy band continuously from April 1991 until June 2000. We present the BATSE Albedo Polarimetry System (BAPS), and show that GRB 930131 and GRB 960924 provide evidence of polarisation in their prompt flux that is consistent with degrees of polarisation of $\\Pi>35$% and $\\Pi>50$% respectively. While the evidence of polarisation is strong, the method is unable to strongly constrain the degree of polarisation beyond a systematics based estimation. Hence the implications on GRB theory are unclear, and further measurements...

  19. A model for distortions of polarisation-angle curves in radio pulsars

    CERN Document Server

    Dyks, J; Oslowski, S; Saha, L; Guillemot, L; Cognard, I; Rudak, B

    2016-01-01

    Some radio pulsar profiles (in particular those of millisecond pulsars contain wide emission structures which cover large intervals of pulse phase. Local distortions of an average curve of polarisation angle (PA) can be identified in such profiles, and they are often found to be associated with absorption features or narrow emission components. The features may be interpreted as a convolution of a lateral profile of an emitter with a microscopic radiation pattern of a non-negligible angular extent. We study a model which assumes that such an extended microbeam of the X-mode curvature radiation is spreading the radiation polarised at a fixed position angle within an interval of pulse phase. The model is capable of interpreting the strongly dissimilar polarisation of double notches in PSR B1821-24A (for which we present new polarisation data from the Nancay Radio Telescope) and PSR J0437-4715. It also explains a step-like change in PA observed at the bifurcated trailing component in the profile of J0437-4715. A...

  20. Results from the Solar Hidden Photon Search (SHIPS)

    CERN Document Server

    Schwarz, Matthias; Lindner, Axel; Redondo, Javier; Ringwald, Andreas; Schneide, Magnus; Susol, Jaroslaw; Wiedemann, Günter

    2015-01-01

    We present the results of a search for transversely polarised hidden photons (HPs) with $\\sim 3$ eV energies emitted from the Sun. These hypothetical particles, known also as paraphotons or dark sector photons, are theoretically well motivated for example by string theory inspired extensions of the Standard Model. Solar HPs of sub-eV mass can convert into photons of the same energy (photon$\\leftrightarrow$HP oscillations are similar to neutrino flavour oscillations). At SHIPS this would take place inside a long light-tight high-vacuum tube, which tracks the Sun. The generated photons would then be focused into a low-noise photomultiplier at the far end of the tube. Our analysis of 330 h of data (and {330 h} of background characterisation) reveals no signal of photons from solar hidden photon conversion. We estimate the rate of newly generated photons due to this conversion to be smaller than 25 mHz/m$^2$ at the 95$%$ C.L. Using this and a recent model of solar HP emission, we set stringent constraints on $\\ch...

  1. Anti-photon

    CERN Document Server

    Moret-Bailly, Jacques

    2010-01-01

    The purpose of this article is neither a compilation, nor a critique of the article by W. E. Lamb of which it gets the name: It adds arguments and applications. Quantum electrodynamics quantizes "normal modes" chosen arbitrarily among the infinity of sets of orthogonal modes of the electromagnetic field. Changing the choice of normal modes splits the photons which are not physical objects. The classical field of electromagnetic energy is often, wrongly, considered as linear, so that Bohr's electron falls on the nucleus and photon counting is false. Using absolute energies and radiances avoids doing these errors. Considering the photons as small particles interacting without pilot waves with single atoms, astrophysicists use Monte-Carlo computations for the propagation of light in homogeneous media while it works only in opalescent media as clouds. Thus, for instance, two theories abort while, they are validated using coherence and Einstein theories, giving a good interpretation of the rings of supernova remna...

  2. Protecting an optical qubit against photon loss

    CERN Document Server

    Wasilewski, W; Wasilewski, Wojciech; Banaszek, Konrad

    2007-01-01

    We consider quantum error-correction codes for multimode bosonic systems, such as optical fields, that are affected by amplitude damping. Such a process is a generalization of an erasure channel. We demonstrate that the most accessible method of transforming optical systems with the help of passive linear networks has limited usefulness in preparing and manipulating such codes. These limitations stem directly from the recoverability condition for one-photon loss. We introduce a three-photon code protecting against the first order of amplitude damping, i.e. a single photon loss, and discuss its preparation using linear optics with single-photon sources and conditional detection. Quantum state and process tomography in the code subspace can be implemented using passive linear optics and photon counting. An experimental proof-of-principle demonstration of elements of the proposed quantum error correction scheme for a one-photon erasure lies well within present technological capabilites.

  3. Security against jamming in imaging with partially-distinguishable photons

    Science.gov (United States)

    Roga, Wojciech; Jeffers, John

    2016-10-01

    We describe a protocol in which we detect intercept-resend jamming of imaging and can reverse its effects. The security is based on control of the polarization states of photons that are sent to interrogate an object and form an image at a camera. The scheme presented here is a particular implementation of a general anti-jamming protocol established by Roga and Jeffers in Ref. 5. It is applied here to imaging by photons with partially distinguishable polarisation states. The protocol in this version is easily applicable as only single photon states are involved, however the efficiency is traded off against the intrusion detectability because of a leak of information to the intruder.

  4. Measurement of $\\psi(2S)$ polarisation in $pp$ collisions at $\\sqrt{s}=7$ TeV

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Balagura, Vladislav; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Bauer, Thomas; Bay, Aurelio; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; van den Brand, Johannes; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Callot, Olivier; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carranza-Mejia, Hector; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coca, Cornelia; Coco, Victor; Cogan, Julien; Cogneras, Eric; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Esen, Sevda; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farry, Stephen; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Giani', Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gordon, Hamish; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hartmann, Thomas; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Iakovenko, Viktor; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jezabek, Marek; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanciotti, Elisa; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Guoming; Lohn, Stefan; Longstaff, Iain; Longstaff, Ian; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luisier, Johan; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Manca, Giulia; Mancinelli, Giampiero; Manzali, Matteo; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Molina Rodriguez, Josue; Monteil, Stephane; Moran, Dermot; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Muresan, Raluca; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Polok, Grzegorz; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Powell, Andrew; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redford, Sophie; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Alexander; Rinnert, Kurt; Rives Molina, Vincente; Roa Romero, Diego; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruffini, Fabrizio; Ruiz, Hugo; Ruiz Valls, Pablo; Sabatino, Giovanni; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sapunov, Matvey; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Senderowska, Katarzyna; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spinella, Franco; Spradlin, Patrick; Stagni, Federico; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teodorescu, Eliza; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Webber, Adam Dane; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wiggers, Leo; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wu, Suzhi; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Feng; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-01-01

    The polarisation of prompt $\\psi(2S)$ mesons is measured by performing an angular analysis of $\\psi(2S)\\rightarrow \\mu^{+} \\mu^{-}$ decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum $p_\\mathrm{T}$ and rapidity $y$ in the kinematic region $3.5polarisation is observed.

  5. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  6. Coupling of translational and rotational motion in chiral liquids in electromagnetic and circularly polarised electric fields.

    Science.gov (United States)

    English, Niall J; Kusalik, Peter G; Woods, Sarah A

    2012-03-07

    Non-equilibrium molecular dynamics simulations of R and S enantiomers of 1,1-chlorofluoroethane, both for pure liquids and racemic mixtures, have been performed at 298 K in the absence and presence of both electromagnetic (e/m) and circularly polarised electric (CP) fields of varying frequency (100-2200 GHz) and intensity (0.025-0.2 V Å(-1) (rms)). Significant non-thermal field effects were noted in the coupling of rotational and translational motion; for instance, in microwave and far-infrared (MW/IR) e/m fields, marked increases in rotational and translational diffusion vis-à-vis the zero-field case took place at 0.025-0.1 V Å(-1) (rms), with a reduction in translational diffusion vis-à-vis the zero-field case above 0.1 V Å(-1) (rms) above 100 GHz. This was due to enhanced direct coupling of rotational motion with the more intense e/m field at the ideal intrinsic rotational coupling frequency (approximately 700 GHz) leading to such rapidly oscillating rotational motion that extent of translational motion was effectively reduced. In the case of CP fields, rotational and translational diffusion was also enhanced for all intensities, particularly at approximately 700 GHz. For both MW/IR and CP fields, non-linear field effects were evident above around 0.1 V Å(-1) (rms) intensity, in terms of enhancements in translational and rotational motion. Simulation of 90-10 mol. % liquid mixtures of a Lennard-Jones solvent with R and S enantiomer-solutes in MW/IR and CP fields led to more limited promotion of rotational and translational diffusion, due primarily to increased frictional effects. For both e/m and CP fields, examination of the laboratory- and inertial-frame auto- and cross-correlation functions of velocity and angular velocity demonstrated the development of explicit coupling with the external fields at the applied frequencies, especially so in the more intense fields where nonlinear effects come into play. For racemic mixtures, elements of the laboratory

  7. Photonic nanowires for quantum optics

    DEFF Research Database (Denmark)

    Munsch, M.; Claudon, J.; Bleuse, J.;

    Photonic nanowires (PWs) are simple dielectric structures for which a very efficient and broadband spontaneous emission (SE) control has been predicted [1]. Recently, a single photon source featuring a record high efficiency was demonstrated using this geometry [2]. Using time-resolved micro......-photoluminescence, we investigate directly the SE of single InAs quantum dots (QDs) embedded in GaAs PWs and demonstrate performances that fully confirm the theoretical predictions [3]. In addition, we discuss recent results obtained on elliptical wires that ensure an efficient control of the photon polarization [4......, equivalent to the one obtained in state-of-the-art 2D photonic crystals, is measured. Moreover, a PW featuring an elliptical section provides a very efficient control over the polarization of the emitted photon. In that case, only one guided mode, with a linear polarization oriented along the major axis...

  8. Photonic crystal surface-emitting lasers

    Science.gov (United States)

    Chua, Song Liang; Lu, Ling; Soljacic, Marin

    2015-06-23

    A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-plane feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.

  9. Hallo photons calls photon; Allo photon appelle photon

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-09-01

    When a pair of photons is created, it seems that these 2 photons are bound together by a mysterious link. This phenomenon has been discovered at the beginning of the seventies. In this new experiment the 2 photons are separated and have to follow different ways through optic cables until they face a quantum gate. At this point they have to chose between a short and a long itinerary. Statistically they have the same probability to take either. In all cases the 2 photons agree to do the same choice even if the 2 quantum gates are distant of about 10 kilometers. Some applications in ciphering and coding of messages are expected. (A.C.)

  10. Photon generator

    Science.gov (United States)

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  11. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2013-01-01

    Microwave photonics continues to see rapid growth. The integration of optical fiber and wireless networks has become a commercial reality and is becoming increasingly pervasive. Such hybrid technology will lead to many innovative applications, including backhaul solutions for mobile networks and ultrabroadband wireless networks that can provide users with very high bandwidth services. Microwave Photonics, Second Edition systematically introduces important technologies and applications in this emerging field. It also reviews recent advances in micro- and millimeter-wavelength and terahertz-freq

  12. Photonic lanterns

    Science.gov (United States)

    Leon-Saval, Sergio G.; Argyros, Alexander; Bland-Hawthorn, Joss

    2013-12-01

    Multimode optical fibers have been primarily (and almost solely) used as "light pipes" in short distance telecommunications and in remote and astronomical spectroscopy. The modal properties of the multimode waveguides are rarely exploited and mostly discussed in the context of guiding light. Until recently, most photonic applications in the applied sciences have arisen from developments in telecommunications. However, the photonic lantern is one of several devices that arose to solve problems in astrophotonics and space photonics. Interestingly, these devices are now being explored for use in telecommunications and are likely to find commercial use in the next few years, particularly in the development of compact spectrographs. Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail. Furthermore, we foreshadow future applications of this technology to the field of nanophotonics.

  13. Leading order determination of the gluon polarisation from DIS events with high-$p_T$ hadron pairs

    CERN Document Server

    Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Burtin, E; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; jr., M.Finger; Fischer, H; Franco, C; von Hohenesche, N.du Fresne; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Hedicke, S; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoppner, Ch; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kunne, F.; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J P; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Procureur, S L; Quaresma, M; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T; Schmidt, K; Schmitt, L; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A

    2013-01-01

    We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised ^6LiD target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x_g. Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09 and a scale of mu^2 = 3~(GeV/c)^2.

  14. Topology optimised planar photonic crystal building blocks

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Hede, K. K.; Borel, Peter Ingo

    A photonic crystal waveguide (PhCW) 1x4 splitter has been constructed from PhCW 60° bends1 and Y-splitters2 that have been designed individually by utilising topology optimisation3. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1) and exhibits a broadband splitting...... for the TE-polarisation with an average excess loss of 1.55±0.54 dB for a 110 nm bandwidth. The 1x4 splitter demonstrates that individual topology-optimised parts can be used as building blocks to realise high-performance nanophotonic circuits. 1L. H. Frandsen et al., Opt. Express 12, 5916-5921 (2004) 2P. I...

  15. Temporary Polarisation Insert for a Time-of-Flight Neutron Reflectometer

    CERN Document Server

    Kreuzpaintner, Wolfgang; Moulin, Jean-François; Wiedemann, Birgit; Ye, Jingfan; Mayr, Sina; Paul, Amitesh; Haese, Martin; Pomm, Matthias; Böni, Peter

    2016-01-01

    The suitability of a transportable 3He-spin filter as broadband polariser for a Time-of-Flight neutron reflectometer in combination with a proposed characterisation method for 3He-spin filters is presented. Both, the experimental simplicity and the data treatment procedure for extracting the spin-up and spin-down neutron reflectivity from measurements obtained for a time dependent 3He polarisation, are shown. For benchmarking, the extraction of a very weak magnetic signal from reflectivity data, measured on the magnetic heterostructure Fe(1nm)/Cu(20nm)/Si(substrate) in an externally applied magnetic field of 30 mT is demonstrated and compared to similar measurements on Cu(20nm)/Si(substrate), which show no magnetic signal.

  16. Study of transverse momentum dependent distributions from polarised Drell-Yan at COMPASS

    Directory of Open Access Journals (Sweden)

    Quaresma Márcia

    2014-06-01

    Full Text Available The Parton Distributions Functions (PDFs and the spin structure of the nucleon are studied by the COMPASS experiment at CERN. The transverse momentum dependent (TMD PDFs of the proton will be accessed via Drell-Yan (DY dimuon production in negative pion collisions on a NH3 transversely polarised target. From this measurement the dimuon azimuthal asymmetries will be extracted, that can be related to 4 TMDs known as transversity, pretzelosity, Sivers and Boer-Mulders. The latter 2 TMDs are time-reversal odd distributions and are expected to change their sign when compared with the ones obtained from Semi-Inclusive Deep Inelastic Scattering, also studied in COMPASS. We aim at performing the first polarised DY measurement starting in 2014.

  17. Spin-lattice interactions studied by polarised and unpolarised inelastic scattering application to the invar problem

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P.J. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1996-11-01

    A semi-quantitative analysis is given of some of the ways in which spin-lattice interactions can modify the cross-sections observable in neutron scattering experiments. This analysis is applied to the scattering from the invar alloy Fe{sub 65}Ni{sub 35} using a model in which the magnetic moment is a function of the near neighbour separation. This model has been applied to clarify the results of inelastic scattering experiments carried out on Fe{sub 65}Ni{sub 35} using both polarised and unpolarised neutrons. The extra information obtainable using polarised neutrons as well as the difficulties and limitations of the technique for inelastic scattering are discussed. (author) 8 figs., 14 refs.

  18. Acousto-optic gyrotropic-crystal-based modulator with a rotating polarisation vector

    Science.gov (United States)

    Kotov, V. M.; Averin, S. V.; Kotov, E. V.; Voronko, A. I.; Tikhomirov, S. A.

    2017-02-01

    We study the influence of ellipticity of gyrotropic-crystal eigenwaves on the output characteristics of an acousto-optic (AO) modulator based on the interferometer scheme. The schemes of AO modulators are considered, which provide the polarisation vector rotation frequency fn/2, where f is the frequency of the acoustic wave, and n is the integer. Preference is given to the scheme combining cascade and polarisation-independent diffraction. An experimental layout of the AO modulator operating at f = 44.5 MHz is described, the modulation frequency of the output laser light intensity being 89 MHz. The frequency of the electrical signal from the photodetector is equal to 179.5 MHz.

  19. Measurement of top quark polarisation in $t$-channel single top quark production

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Brun, Hugues; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Fasanella, Giuseppe; Favart, Laurent; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Abdelalim, Ahmed Ali; Awad, Adel; El Sawy, Mai; Mahrous, Ayman; Radi, Amr; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Dahms, Torsten; Davignon, Olivier; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Jo, Mihee; Lisniak, Stanislav; Mastrolorenzo, Luca; Miné, Philippe; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Merlin, Jeremie Alexandre; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schulte, Jan-Frederik; Verlage, Tobias; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behnke, Olaf; Behrens, Ulf; Bell, Alan James; Borras, Kerstin; Burgmeier, Armin; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Trippkewitz, Karim Damun; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Gonzalez, Daniel; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Nowatschin, Dominik; Ott, Jochen; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Rathjens, Denis; Sander, Christian; Scharf, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schwandt, Joern; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Fink, Simon; Frensch, Felix; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Sieber, Georg; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hazi, Andras; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Mal, Prolay; Mandal, Koushik; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutta, Suchandra; Jain, Sandhya; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukherjee, Swagata; Mukhopadhyay, Supratik; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Mahakud, Bibhuprasad; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sarkar, Tanmay; Sur, Nairit; Sutar, Bajrang; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Kothekar, Kunal; Sharma, Seema; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dorigo, Tommaso; Dosselli, Umberto; Fanzago, Federica; Gasparini, Fabrizio; Gasparini, Ugo; Gonella, Franco; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Zanetti, Anna; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Sakharov, Alexandre; Son, Dong-Chul; Brochero Cifuentes, Javier Andres; Kim, Hyunsoo; Kim, Tae Jeong; Song, Sanghyeon; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Hong, Byung-Sik; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Leonardo, Nuno; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Bunichev, Viacheslav; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Klyukhin, Vyacheslav; Kodolova, Olga; Korneeva, Natalia; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Perfilov, Maxim; Savrin, Viktor; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Soares, Mara Senghi; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Palencia Cortezon, Enrique; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; De Castro Manzano, Pablo; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Berruti, Gaia Maria; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Castello, Roberto; Cerminara, Gianluca; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Du Pree, Tristan; Duggan, Daniel; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Fulcher, Jonathan; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; 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Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Field, Richard D; Furic, Ivan-Kresimir; Gleyzer, Sergei V; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Low, Jia Fu; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Rank, Douglas; Rossin, Roberto; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Jordon Rowe; Adams, Todd; Askew, Andrew; Bein, Samuel; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Khatiwada, Ajeeta; Prosper, Harrison; Weinberg, Marc; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Kalakhety, Himali; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Wu, Zhenbin; Zakaria, Mohammed; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; 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Shin, Young Ho; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Baty, Austin; Bierwagen, Katharina; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; Demiragli, Zeynep; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Dahmes, Bryan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; 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Arenton, Michael Wayne; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Wood, John; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Sarangi, Tapas; Savin, Alexander; Sharma, Archana; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

    2016-01-01

    A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in $t$-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb$^{-1}$. A high-purity sample of $t$-channel single top quark events with an isolated muon is selected. Signal and background components are estimated using a fit to data. A differential cross section measurement, corrected for detector effects, of an angular observable sensitive to the top quark polarisation is performed. The differential distribution is used to extract a top quark spin asymmetry of 0.26 $\\pm$ 0.03 (stat) $\\pm$ 0.10 (syst), which is compatible with a $p$-value of 4.6% with the standard model prediction of 0.44.

  20. Doppler ghosts in a hall of mirrors polarisation profiles of scattered emission lines

    CERN Document Server

    Henney, W J

    1994-01-01

    The Doppler shifts of optical emission lines which have been scattered by surrounding dust and electrons can provide useful information about the kinematics, geometry and physical conditions of astrophysical flows. In principle, the scatterers can provide views of the line-emitting gas from different directions, allowing the 3-d velocity field of the emitting gas to be determined and revealing sources which are hidden from direct view. Unfortunately, as in a Hall of Mirrors, the resultant multiple images can be confusing and hard to interpret. In general, the scattering geometry will be unknown, which makes it difficult to disentangle the effect of the motion of the scatterers from that of the motion of the emitting source. In this situation, spectropolarimetric observations can be a great help, since the scattered light will be partially polarised to a degree dependent on the angle of scattering and on the details of the scattering process. Analysis of the polarisation profiles of the scattered emission line...

  1. Measurement of top quark polarisation in t-channel single top quark production

    CERN Document Server

    Tiko, Andres

    2016-01-01

    A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in $t$-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 $\\mathrm{fb^{-1}}$. A high-purity sample of $t$-channel single top quark events with an isolated muon is selected. Signal and background components are estimated using a fit to data. A differential cross section measurement, corrected for detector effects, of an angular observable sensitive to the top quark polarisation is performed. The differential distribution is used to extract a top quark spin asymmetry of $0.26 \\pm 0.03 \\textrm{(stat)} \\pm 0.10 \\textrm{(syst)}$, which is compatible with a p-value of $4.6\\%$ with the standard model prediction of 0.44.

  2. Heavy flavour corrections to polarised and unpolarised deep-inelastic scattering at 3-loop order

    CERN Document Server

    Ablinger, Jakob; Blümlein, Johannes; De Freitas, Abilio; Hasselhuhn, Alexander; von Manteuffel, Andreas; Round, Mark; Schneider, Carsten; Wißbrock, Fabian

    2016-01-01

    We report on progress in the calculation of 3-loop corrections to the deep-inelastic structure functions from massive quarks in the asymptotic region of large momentum transfer $Q^2$. Recently completed results allow us to obtain the $O(a_s^3)$ contributions to several heavy flavour Wilson coefficients which enter both polarised and unpolarised structure functions for lepton-nucleon scattering. In particular, we obtain the non-singlet contributions to the unpolarised structure functions $F_2(x,Q^2)$ and $x F_3(x,Q^2)$ and the polarised structure function $g_1(x,Q^2)$. From these results we also obtain the heavy flavour contributions to the Gross-Llewellyn-Smith and the Bjorken sum rules.

  3. Polarised SANS study of microstructural evolution under neutron irradiation in a martensitic steel for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Coppola, R.; Dewhurst, C.D.; Lindau, R.; May, R.P.; Moeslang, A.; Valli, M

    2004-03-01

    This work presents the results of polarised small-angle neutron scattering (SANS) measurements of modified martensitic steel DIN1.4914, originally developed for application in future fusion reactors (MANET steel). SANS measurements were made using the D22 instrument at the ILL Grenoble using an ad hoc polarised beam set-up. The investigated MANET samples were neutron irradiated and subsequently post-irradiation tempered to reproduce as much as possible the expected service conditions. The results, based on the analysis of the nuclear-magnetic interference, are discussed taking into account both the occurrence of Cr redistribution phenomena with correlated changes in the composition of the precipitate phases, and the growth of non-magnetic defects (He-bubbles or microvoids)

  4. Polarisations of quasi-waves in a general anisotropic porous solid saturated with viscous liquid

    Indian Academy of Sciences (India)

    M D Sharma

    2005-08-01

    Wave propagation is studied in a general anisotropic poroelastic solid saturated with a viscous fluid flowing through its pores of anisotropic permeability. The extended version of Biot's theory is used to derive a system of modified Christoffel equations for the propagation of plane harmonic waves in such media. The non-trivial solution of this system is ensured by a biquadratic equation whose roots represent the complex velocities of four attenuating quasi-waves in the medium. These complex velocities define phase velocity and attenuation of each quasi-wave propagating along a given phase direction in three-dimensional space. The solution itself defines the polarisations of the quasi-waves along with phase shift. The variations of polarisations of quasi-waves with their phase direction, are computed for a realistic numerical model.

  5. Strain effects on optical polarisation properties in(11(2)2)plane GaN films

    Institute of Scientific and Technical Information of China (English)

    Hao Guo-Dong; Chen Yong-Hai; Fan Ya-Ming; Huang Xiao-Hui; Wang Huai-Bing

    2010-01-01

    We present the theoretical results of the electronic band structure of wurtzite GaN films under biaxial strains in the(1122)-plane.The calculations are performed by the κ·p perturbation theory approach through using the effectivemass Hamiltonian for an arbitrary direction.The results show that the transition energies decrease with the biaxial strains changing from-0.5% to 0.5%.For films of(11(2)2)-plane,the strains are expected to be anisotropic in the growth plane.Such anisotropic strains give rise to valence band mixing which results in dramatic change in optical polarisation property.The strain can also result in optical polarisation switching phenomena.Finally,we discuss the applications of these properties to the(1122)plane GaN-based light-emitting diode and lase diode.

  6. Normal tau polarisation as a sensitive probe of CP violation in chargino decay

    CERN Document Server

    Dreiner, Herbi K; Marold, Anja

    2010-01-01

    CP violation in the spin-spin correlations in chargino production and subsequent two-body decay into a tau and a tau-sneutrino is studied at the ILC. From the normal polarisation of the tau, an asymmetry is defined to test the CP-violating phase of the higgsino mass parameter \\mu. Asymmetries of more than \\pm70% are obtained, also in scenarios with heavy first and second generation sfermions. Bounds on the statistical significances of the CP asymmetries are estimated. As a result, the normal tau polarisation in the chargino decay is one of the most sensitive probes to constrain or measure the phase \\phi_\\mu at the ILC, motivating further detailed experimental studies.

  7. Polarisation maintaining fibre with pure silica core and two depressed claddings for fibre optic gyroscope

    Science.gov (United States)

    Kurbatov, A. M.; Kurbatov, R. A.; Voloshin, V. V.; Vorob'ev, I. L.; Kolosovsky, A. O.

    2016-12-01

    Polarisation maintaining (PM) fibre is described with pure silica core and two depressed claddings for fibre optic gyro (FOG) sensing coil. Detailed mathematical simulation is presented by supermodes method, which is extremely necessary for such fibre. Simulation is fulfilled by frequency domain finite difference method (FDFDM), taking into account all details of realistic index profile with stress applying parts, while the leakage/bend loss occur in the region with complex index, surrounding the fibre. Cutoff and small bend loss are theoretically predicted and experimentally measured with excellent agreement between theory and experiment. Polarisation maintaining ability is measured in the form of conventional h-parameter (7.1·10-6 1/m) for 90-μm diameter fibre with birefringence value only 3.9·10-4.

  8. Discrimination of water, ice and aerosols by light polarisation in the CLOUD experiment

    Directory of Open Access Journals (Sweden)

    L. Nichman

    2015-11-01

    Full Text Available Cloud microphysical processes involving the ice phase in tropospheric clouds are among the major uncertainties in cloud formation, weather and General Circulation Models (GCMs. The simultaneous detection of aerosol particles, liquid droplets, and ice crystals, especially in the small cloud-particle size range below 50 μm, remains challenging in mixed phase, often unstable ice-water phase environments. The Cloud Aerosol Spectrometer with Polarisation (CASPOL is an airborne instrument that has the ability to detect such small cloud particles and measure their effects on the backscatter polarisation state. Here we operate the versatile Cosmics-Leaving-OUtdoor-Droplets (CLOUD chamber facility at the European Organisation for Nuclear Research (CERN to produce controlled mixed phase and other clouds by adiabatic expansions in an ultraclean environment, and use the CASPOL to discriminate between different aerosols, water and ice particles. In this paper, optical property measurements of mixed phase clouds and viscous Secondary Organic Aerosol (SOA are presented. We report observations of significant liquid – viscous SOA particle polarisation transitions under dry conditions using CASPOL. Cluster analysis techniques were subsequently used to classify different types of particles according to their polarisation ratios during phase transition. A classification map is presented for water droplets, organic aerosol (e.g., SOA and oxalic acid, crystalline substances such as ammonium sulphate, and volcanic ash. Finally, we discuss the benefits and limitations of this classification approach for atmospherically relevant concentration and mixtures with respect to the CLOUD 8–9 campaigns and its potential contribution to Tropical Troposphere Layer (TTL analysis.

  9. Compact magnetostatic cavity for polarised {sup 3}He neutron spin filter cells

    Energy Technology Data Exchange (ETDEWEB)

    Petoukhov, A.K. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France)]. E-mail: petukhov@ill.fr; Guillard, V. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Andersen, K.H. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Bourgeat-Lami, E. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Chung, R. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Humblot, H. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Jullien, D. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Lelievre-Berna, E. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Soldner, T. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Tasset, F. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France); Thomas, M. [Institute Laue-Langevin, 6, rue Jules Horowitz, B.P. 156, 38042 Grenoble Cedex 9 (France)

    2006-05-10

    We present a concept for a compact magnetostatic cavity called a 'Magic box' that provides a very homogeneous magnetic environment for a polarised {sup 3}He neutron spin-filter cell in the presence of moderate magnetic stray fields. Based on this concept different systems have been built and tested. The concept is ideal for the transport or hosting of a spin-filter on a neutron beam-line.

  10. Probing the spiral magnetic phase in 6 nm textured erbium using polarised neutron reflectometry

    Science.gov (United States)

    Satchell, N.; Witt, J. D. S.; Burnell, G.; Curran, P. J.; Kinane, C. J.; Charlton, T. R.; Langridge, S.; Cooper, J. F. K.

    2017-02-01

    We characterise the magnetic state of highly-textured, sputter deposited erbium for a film of thickness 6 nm. Using polarised neutron reflectometry it is found that the film has a high degree of magnetic disorder, and we present some evidence that the film’s local magnetic state is consistent with bulk-like spiral magnetism. This, combined with complementary characterisation techniques, show that thin film erbium is a strong candidate material for incorporation into device structures.

  11. Electromagnetic polarisabilities of the proton in an independent particle potential model

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N. [Utkal Univ., Bhubaneswer (India). P.G. Dept. of Phys.; Dash, B.K. [Utkal Univ., Bhubaneswer (India). P.G. Dept. of Phys.; Das, P. [Department of Physics, Kendrapara College, Kendrapara-754211 (India); Panda, A.R. [Department of Physics, Kendrapara College, Kendrapara-754211 (India)

    1996-08-19

    We consider the electric and magnetic polarisabilities of the proton including the valence quark as well as pion dressing effects in an independent quark model with an effective scalar-vector harmonic potential which renders the solvability of relativistic Dirac equations for confined quarks, and has in fact acted as an alternative to the cloudy bag model (CBM). This model which has been applied successfully to a variety of hadronic problems is also observed here to yield the electromagnetic polarisabilities of the proton satisfactorily without any free parameters. The electric and magnetic polarisabilities, including valence quark core and pion cloud effects, obtained here as anti {alpha}{sub P}=14.074.10{sup -4} fm{sup 3} and anti {beta}{sub P}=3.155.10{sup -4} fm{sup 3}, are well within the uncertainties of their experimental measurements of (10.9{+-}2.2{+-}1.4).10{sup -4} fm{sup 3} and (3.3{+-}2.2{+-}1.4).10{sup -4} fm{sup 3}, respectively and are also in agreement with other model estimations. (orig.).

  12. Use of scanning LIMM (Laser Intensity Modulation Method) to characterise polarisation variability in dielectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Mark; Cain, Markys, E-mail: mark.stewart@npl.co.u [National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom)

    2009-08-01

    The Laser Intensity Modulation Method (LIMM) has traditionally been used to characterise the depth dependence of polarisation of piezoelectric materials{sup 1}. Although the technique is simple, it is difficult to extract the polarisation / depth data from the measured pyroelectric current because of the complex mathematics pertaining to the physics of the technique. However, the laser probe may still be used as a comparative or qualitative tool in mapping out the polarisation across the surface of a material. A novel scanning LIMM system has been developed to map the variation in piezoelectric activity across a range of samples. The system has been upgraded with a galvanometer mirror scanner to increase speed and reduce sensitivity to acoustic noise. The improvements are discussed and tested on a range of case studies. The technique can be used to show differences in piezoelectric activity caused by features such as inhomogeneous material composition, porosity and mechanical damage. The method has application as a quality control tool for materials and device manufacturers.

  13. The multi-viewing, multi-channel, multi-polarisation imager on board the future EUMETSAT Polar System - Second Generation and its application for the aerosol retrieval

    Science.gov (United States)

    Kokhanovsky, Alexander; Munro, Rose; Lang, Ruediger; Lindstrot, Rasmus; Huckle, Roger; Marbach, Thierry; Poli, Gabriele

    2017-04-01

    Atmospheric aerosol is a global phenomenon. Due to the small size of aerosol particles (typically, 0.1 - 10 micrometers) they are rarely observed by the naked eye. Nevertheless aerosol particles are present in atmospheric air in variable numbers (typically, 100-1000 particles per cubic centimeter of atmospheric air). The particles have different chemical composition, origin, shapes, and internal structure (e.g., dust particles covered by ice, etc.). They influence human health, air quality, climate, downwelling and upwelling radiation, clouds, and precipitation. It is therefore important to monitor aerosol properties on a global scale. Global scale information can only be provided by satellite observations and algorithms for the production of satellite-based aerosol products have been in use already for more than 40 years. In this work we present an update on the recently developed operational EUMETSAT aerosol retrieval algorithm for the Multi-viewing, multi-channel, multi-polarisation Imager (3MI) which will fly on board the future EUMETSAT Polar System Second Generation (EPS-SG), planned for launch in the 2021 timeframe. The 3MI is a two - dimensional push - broom radiometer dedicated to aerosol and cloud characterization for climate monitoring, air quality forecasting and numerical weather prediction with heritage from the POLDER instrument. The first three components of the Stokes vector of the reflected light (I, Q, and U) will be measured at 9 channels in the spectral range from 410 to 2130nm for up to 14 observation directions. Intensity measurements only will be performed at 763, 765, and 910nm. This enables the determination of the degree of linear polarization of reflected light and also the direction of the oscillations of the electric vector in the light beam. The 3MI design consists of a filter and polariser wheel rotating in front of the detectors. For design purposes the spectral channels have been split into VNIR and SWIR filters and polarisers with

  14. Nanoscale precision of 3D polymerisation via polarisation control

    CERN Document Server

    Rekstyte, Sima; Gailevicius, Darius; Malinauskas, Mangirdas; Mizeikis, Vygantas; Gamaly, Eugene G; Juodkazis, Saulius

    2016-01-01

    A systematic analysis of polarization effects in a direct write femtosecond laser 3D lithography is presented. It is newly shown that coupling between linear polarization of the writing light electric field and temperature gradient can be used to fine-tune feature sizes in structuring of photoresists at a nanoscale. The vectorial Debye focusing is used to simulate polarization effects and a controlled variation up to 20% in the linewidth is shown experimentally for the identical axial extent of the polymerised features. The revealed mechanisms are relevant for a wide range of phenomena of light-matter interaction at tight focusing in laser-tweezers and in plasmonic or dielectric sub-wavelength focusing where strong light intensity and thermal gradients coexist.

  15. Harmonic distortion in microwave photonic filters.

    Science.gov (United States)

    Rius, Manuel; Mora, José; Bolea, Mario; Capmany, José

    2012-04-09

    We present a theoretical and experimental analysis of nonlinear microwave photonic filters. Far from the conventional condition of low modulation index commonly used to neglect high-order terms, we have analyzed the harmonic distortion involved in microwave photonic structures with periodic and non-periodic frequency responses. We show that it is possible to design microwave photonic filters with reduced harmonic distortion and high linearity even under large signal operation.

  16. Quantum photonics

    CERN Document Server

    Pearsall, Thomas P

    2017-01-01

    This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schrödinger’s equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non­locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch’s theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconducto...

  17. Linearization Techniques

    Directory of Open Access Journals (Sweden)

    Gildeberto S. Cardoso

    2011-01-01

    Full Text Available This paper presents a study of linear control systems based on exact feedback linearization and approximate feedback linearization. As exact feedback linearization is applied, a linear controller can perform the control objectives. The approximate feedback linearization is required when a nonlinear system presents a noninvolutive property. It uses a Taylor series expansion in order to compute a nonlinear transformation of coordinates to satisfy the involutivity conditions.

  18. Photonic crystals

    CERN Document Server

    Busch, Kurt; Wehrspohn, Ralf B; Föll, Helmut

    2006-01-01

    The majority of the contributions in this topically edited book stems from the priority program SPP 1113 ""Photonische Kristalle"" run by the Deutsche Forschungsgemeinschaft (DFG), resulting in a survey of the current state of photonic crystal research in Germany. The first part of the book describes methods for the theoretical analysis of their optical properties as well as the results. The main part is dedicated to the fabrication, characterization and modeling of two- and three-dimensional photonic crystals, while the final section presents a wide spectrum of applications: gas sensors, micr

  19. Green photonics

    Science.gov (United States)

    Quan, Frederic

    2012-02-01

    Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas.

  20. Photonic crystals principles and applications

    CERN Document Server

    Gong, Qihuang

    2013-01-01

    IntroductionPrimary Properties of Photonic CrystalsFabrication of Photonic CrystalsPhotonic Crystal All-Optical SwitchingTunable Photonic Crystal FilterPhotonic Crystal LaserPhotonic Crystal Logic DevicesPhotonic Crystal Sensors

  1. Photonic Bandgaps in Photonic Molecules

    Science.gov (United States)

    Smith, David D.; Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    This talk will focus on photonic bandgaps that arise due to nearly free photon and tight-binding effects in coupled microparticle and ring-resonator systems. The Mie formulation for homogeneous spheres is generalized to handle core/shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multi-layered structures to be treated as photonic bandgap (PBG) materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands arising from nearly free photon effects are easily observed in the backscattering, asymmetry parameter, and albedo for periodic quarter-wave concentric layers, though are not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, enhancing the ratio of backscattering to forward scattering inside the bandgap, in direct analogy with planar quarter-wave multilayers. PBGs arising from tight-binding may also be observed when the layers (or rings) are designed such that the coupling between them is weak. We demonstrate that for a structure consisting of N coupled micro-resonators, the morphology dependent resonances split into N higher-Q modes, in direct analogy with other types of oscillators, and that this splitting ultimately results in PBGs which can lead to enhanced nonlinear optical effects.

  2. Thermally induced photon splitting

    CERN Document Server

    Elmfors, P; Elmfors, Per; Skagerstam, Bo-Sture

    1998-01-01

    We calculate thermal corrections to the non-linear QED effective action for low-energy photon interactions in a background electromagnetic field. The high-temperature expansion shows that at $T \\gg m$ the vacuum contribution is exactly cancelled to all orders in the external field except for a non-trivial two-point function contribution. The high-temperature expansion derived reveals a remarkable cancellation of infrared sensitive contributions. As a result photon-splitting in the presence of a magnetic field is suppressed in the presence of an electron-positron QED-plasma at very high temperatures. In a cold and dense plasma a similar suppression takes place. At the same time Compton scattering dominates for weak fields and the suppression is rarely important in physical situations.

  3. Photon differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Revall Frisvad, Jeppe; Erleben, Kenny;

    2007-01-01

    illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation...

  4. Spatial solitons in nonlinear photonic crystals

    DEFF Research Database (Denmark)

    Corney, Joel Frederick; Bang, Ole

    2000-01-01

    We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero.......We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero....

  5. QUIJOTE scientific results - I. Measurements of the intensity and polarisation of the anomalous microwave emission in the Perseus molecular complex

    Science.gov (United States)

    Génova-Santos, R.; Rubiño-Martín, J. A.; Rebolo, R.; Peláez-Santos, A.; López-Caraballo, C. H.; Harper, S.; Watson, R. A.; Ashdown, M.; Barreiro, R. B.; Casaponsa, B.; Dickinson, C.; Diego, J. M.; Fernández-Cobos, R.; Grainge, K. J. B.; Gutiérrez, C. M.; Herranz, D.; Hoyland, R.; Lasenby, A.; López-Caniego, M.; Martínez-González, E.; McCulloch, M.; Melhuish, S.; Piccirillo, L.; Perrott, Y. C.; Poidevin, F.; Razavi-Ghods, N.; Scott, P. F.; Titterington, D.; Tramonte, D.; Vielva, P.; Vignaga, R.

    2015-10-01

    In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10-20 GHz observations (194 h in total over ≈250 deg2) in intensity and polarisation of G159.6-18.5, one of the most widely studied regions harbouring anomalous microwave emission (AME). By combining with other publicly available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOlogical Structures On Medium Angular Scales experiment in this region. Our polarisation maps, which have an angular resolution of ≈1° and a sensitivity of ≈ 25 μK beam-1, are consistent with zero polarisation. We obtain upper limits on the polarisation fraction of Π < 6.3 and <2.8 per cent (95 per cent C.L.), respectively, at 12 and 18 GHz (ΠAME < 10.1 and <3.4 per cent with respect to the residual AME intensity), a frequency range where no AME polarisation observations have been reported to date. The combination of these constraints with those from other experiments confirm that all the magnetic dust models based on single-domain grains, and most of those considering randomly oriented magnetic inclusions, predict higher polarisation levels than is observed towards regions with AME. Also, neither of the two considered models of electric dipole emission seems to be compatible with all the observations together. More stringent constraints of the AME polarisation at 10-40 GHz are necessary to disentangle between different models, to which future QUIJOTE data will contribute.

  6. Linear algebra

    CERN Document Server

    Shilov, Georgi E

    1977-01-01

    Covers determinants, linear spaces, systems of linear equations, linear functions of a vector argument, coordinate transformations, the canonical form of the matrix of a linear operator, bilinear and quadratic forms, Euclidean spaces, unitary spaces, quadratic forms in Euclidean and unitary spaces, finite-dimensional space. Problems with hints and answers.

  7. Linear Psoriasis

    Directory of Open Access Journals (Sweden)

    Agarwalla Arun

    2001-01-01

    Full Text Available Linear psoriasis, inflammatory linear varrucous epidermal naevus (ILVEN. Lichen straitus, linear lichen planus and invasion of epidermal naevi by psoriasis have clinical and histopathological overlap. We report two young male patients of true linear psoriasis without classical lesions elsewhere which were proved histopathologically. Seasonal variation and good response to topical antipsoriatic treatment supported the diagnosis.

  8. Topology optimization of nano-photonic systems

    DEFF Research Database (Denmark)

    Elesin, Yuriy; Wang, Fengwen; Andkjær, Jacob Anders;

    2012-01-01

    We describe recent developments within nano-photonic systems design based on topology optimization. Applications include linear and non-linear optical waveguides, slow-light waveguides, as well as all-dielectric cloaks that minimize scattering or back-scattering from hard obstacles.......We describe recent developments within nano-photonic systems design based on topology optimization. Applications include linear and non-linear optical waveguides, slow-light waveguides, as well as all-dielectric cloaks that minimize scattering or back-scattering from hard obstacles....

  9. Rydberg atoms in hollow-core photonic crystal fibres

    CERN Document Server

    Epple, G; Euser, T G; Joly, N Y; Pfau, T; Russell, P St J; Löw, R

    2014-01-01

    The exceptionally large polarisability of highly excited Rydberg atoms (six orders of magnitude higher than ground-state atoms) makes them of great interest in fields such as quantum optics, quantum computing, quantum simulation and metrology. If however they are to be used routinely in applications, a major requirement is their integration into technically feasible, miniaturised devices. Here we show that a Rydberg medium based on room temperature caesium vapour can be confined in broadband-guiding kagome-style hollow-core photonic crystal fibres. Three-photon spectroscopy performed on a caesium-filled fibre detects Rydberg states up to a principal quantum number of n = 40. Besides small energy level shifts we observe narrow lines confirming the coherence of the Rydberg excitation. Using different Rydberg states and core diameters we study the influence of confinement within the fibre core after different exposure times. Understanding these effects is essential for the successful future development of novel ...

  10. Studying Higgs bosons by top pair production at photon colliders

    CERN Document Server

    Asakawa, E

    2004-01-01

    We study the effect of heavy neutral Higgs bosons on the top pair production process at photon linear colliders.The interference patterns betwenn the resonant Higgs production amplitudes and the continuum QED amplitudes are examined. The patterns are sensitive to the phase of the photon-photon-Higgs vertex which is a good probe of new charged particles.

  11. Nonlinear Photonics and Novel Optical Phenomena

    CERN Document Server

    Morandotti, Roberto

    2012-01-01

    Nonlinear Photonics and Novel Optical Phenomena contains contributed chapters from leading experts in nonlinear optics and photonics, and provides a comprehensive survey of fundamental concepts as well as hot topics in current research on nonlinear optical waves and related novel phenomena. The book covers self-accelerating airy beams, integrated photonics based on high index doped-silica glass, linear and nonlinear spatial beam dynamics in photonic lattices and waveguide arrays, polariton solitons and localized structures in semiconductor microcavities, terahertz waves, and other novel phenomena in different nanophotonic and optical systems.

  12. Study of the pd→→n{pp}s charge-exchange reaction using a polarised deuterium target

    Directory of Open Access Journals (Sweden)

    B. Gou

    2015-02-01

    Full Text Available The vector and tensor analysing powers, Ay and Ayy, of the pd→→n{pp}s charge-exchange reaction have been measured at a beam energy of 600 MeV at the COSY-ANKE facility by using an unpolarised proton beam incident on an internal storage cell target filled with polarised deuterium gas. The low energy recoiling protons were measured in a pair of silicon tracking telescopes placed on either side of the target. Putting a cut of 3 MeV on the diproton excitation energy ensured that the two protons were dominantly in the S01 state, here denoted by {pp}s. The polarisation of the deuterium gas was established through measurements in parallel of proton–deuteron elastic scattering. By analysing events where both protons entered the same telescope, the charge-exchange reaction was measured for momentum transfers q≥160 MeV/c. These data provide a good continuation of the earlier results at q≤140 MeV/c obtained with a polarised deuteron beam. They are also consistent with impulse approximation predictions with little sign evident for any modifications due to multiple scatterings. These successful results confirm that the ANKE deuteron charge-exchange programme can be extended to much higher energies with a polarised deuterium target than can be achieved with a polarised deuteron beam.

  13. Late summer sea ice segmentation with multi-polarisation SAR features in C- and X-band

    Directory of Open Access Journals (Sweden)

    A. S. Fors

    2015-09-01

    Full Text Available In this study we investigate the potential of sea ice segmentation by C- and X-band multi-polarisation synthetic aperture radar (SAR features during late summer. Five high-resolution satellite SAR scenes were recorded in the Fram Strait covering iceberg-fast first-year and old sea ice during a week with air temperatures varying around zero degrees Celsius. In situ data consisting of sea ice thickness, surface roughness and aerial photographs were collected during a helicopter flight at the site. Six polarimetric SAR features were extracted for each of the scenes. The ability of the individual SAR features to discriminate between sea ice types and their temporally consistency were examined. All SAR features were found to add value to sea ice type discrimination. Relative kurtosis, geometric brightness, cross-polarisation ratio and co-polarisation correlation angle were found to be temporally consistent in the investigated period, while co-polarisation ratio and co-polarisation correlation magnitude were found to be temporally inconsistent. An automatic feature-based segmentation algorithm was tested both for a full SAR feature set, and for a reduced SAR feature set limited to temporally consistent features. In general, the algorithm produces a good late summer sea ice segmentation. Excluding temporally inconsistent SAR features improved the segmentation at air temperatures above zero degrees Celcius.

  14. Large solid-angle polarisation analysis at thermal neutron wavelengths using a sup 3 He spin filter

    CERN Document Server

    Heil, W; Cywinski, R; Humblot, H; Ritter, C; Roberts, T W; Stewart, J R

    2002-01-01

    The strongly spin-dependent absorption of neutrons in nuclear spin-polarised sup 3 He opens up the possibility of polarising neutrons from reactors and spallation sources over the full kinematical range of cold, thermal and hot neutrons. In this paper we describe the first large solid-angle polarisation analysis measurement using a sup 3 He neutron spin filter at thermal neutron wavelengths (lambda=2.5 A). This experiment was performed on the two-axis diffractometer D1B at the Institut Laue-Langevin using a banana-shaped filter cell (530 cm sup 3 ) filled with sup 3 He gas with a polarisation of P=52% at a pressure of 2.7 bar. A comparison is made with a previous measurement on D7 using a cold neutron beam on the same sample, i.e. amorphous ErY sub 6 Ni sub 3. Using uniaxial polarisation analysis both the nuclear and magnetic cross-sections could be extracted over the range of scattering-vectors [0.5<=Q(A sup - sup 1)<=3.5]. The results are in qualitative and quantitative agreement with the D7-data, whe...

  15. Nano-photonics in III-V semiconductors for integrated quantum optical circuits

    Science.gov (United States)

    Wasley, Nicholas Andrew

    This thesis describes the optical spectroscopic measurements of III-V semiconductors used to investigate a number of issues related to the development of integrated quantum optical circuits. The disorder-limited propagation of photons in photonic crystal waveguides in the slow-light regime is investigated. The analysis of Fabry-Perot resonances is used to map the mode dispersion and extract the photon localisation length. Andersonlocalised modes are observed at high group indices, when the localisation lengths are shorter than the waveguide lengths, consistent with the Fabry-Perot analysis. A spin-photon interface based on two orthogonal waveguides is introduced, where the polarisation emitted by a quantum dot is mapped to a path-encoded photon. Operation is demonstrated by deducing the spin using the interference of in-plane photons. A second device directly maps right and left circular polarisations to anti-parallel waveguides, surprising for a non-chiral structure but consistent with an off-centre dot. Two dimensional photonic crystal cavities in GaInP and full control over the spontaneous emission rate of InP quantum dots is demonstrated by spectrally tuning the exciton emission energy into resonance with the fundamental cavity mode. Fourier transform spectroscopy is used to investigate the short coherence times of InP quantum dots in GaInP photonic crystal cavities. Additional technological developments are also presented including a quantum dot registration technique, electrical tuning of quantum dot emission and uniaxial strain tuning of H1 cavity modes.

  16. Detection of elastic photon-photon scattering through four-wave coupling

    CERN Document Server

    Lundstrom, E

    2005-01-01

    According to the theory of quantum electrodynamics, photon-photon scattering can take place via exchange of virtual electron-positron pairs. Effectively, the interaction can be formulated in terms of non-linear corrections to Maxwell's equations, and hence may be treated by classical non-linear electrodynamics. Due to the strong electromagnetic fields needed to reach any noticeable effect, photon-photon scattering has not yet been observed experimentally, but recent improvements in laser technology have increased the possibility of direct detection. A verification of the phenomena would be of great scientific value as a confirmation of quantum electrodynamics. In this thesis the possibility of direct detection of elastic photon-photon scattering through four-wave coupling is investigated, both for current and future systems. It is shown how three colliding laser pulses satisfying certain matching conditions, can generate scattered radiation in a fourth resonant direction. The interaction is modeled, and the n...

  17. Propagation of TE and TM polarised light through smoothed sixty degree bends in planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Thorhauge, Morten;

    2003-01-01

    In this paper, bends in planar PCWs are investigated by introducing two smoothed 60° bends each having one hole. The PCWs are defined by leaving out single rows of holes. In and out coupling of light to the PCWs is obtained utilising tapered ridge waveguides. Transmission spectra are recorded...

  18. Chitosan drives anti-inflammatory macrophage polarisation and pro-inflammatory dendritic cell stimulation

    Directory of Open Access Journals (Sweden)

    MI Oliveira

    2012-07-01

    Full Text Available Macrophages and dendritic cells (DC share the same precursor and play key roles in immunity. Modulation of their behaviour to achieve an optimal host response towards an implanted device is still a challenge. Here we compare the differentiation process and polarisation of these related cell populations and show that they exhibit different responses to chitosan (Ch, with human monocyte-derived macrophages polarising towards an anti-inflammatory phenotype while their DC counterparts display pro-inflammatory features. Macrophages and DC, whose interactions with biomaterials are frequently analysed using fully differentiated cells, were cultured directly on Ch films, rather than exposed to the polymer after complete differentiation. Ch was the sole stimulating factor and activated both macrophages and DC, without leading to significant T cell proliferation. After 10 d on Ch, macrophages significantly down-regulated expression of pro-inflammatory markers, CD86 and MHCII. Production of pro-inflammatory cytokines, particularly TNF-α, decreased with time for cells cultured on Ch, while anti-inflammatory IL-10 and TGF-β1, significantly increased. Altogether, these results suggest an M2c polarisation. Also, macrophage matrix metalloproteinase activity was augmented and cell motility was stimulated by Ch. Conversely, DC significantly enhanced CD86 expression, reduced IL-10 secretion and increased TNF-α and IL-1β levels. Our findings indicate that cells with a common precursor may display different responses, when challenged by the same biomaterial. Moreover, they help to further comprehend macrophage/DC interactions with Ch and the balance between pro- and anti-inflammatory signals associated with implant biomaterials. We propose that an overall pro-inflammatory reaction may hide the expression of anti-inflammatory cytokines, likely relevant for tissue repair/regeneration.

  19. Spatiotemporal Cadence of Macrophage Polarisation in a Model of Light-Induced Retinal Degeneration.

    Directory of Open Access Journals (Sweden)

    Haihan Jiao

    Full Text Available The recruitment of macrophages accompanies almost every pathogenic state of the retina, and their excessive activation in the subretinal space is thought to contribute to the progression of diseases including age-related macular degeneration. Previously, we have shown that macrophages aggregate in the outer retina following damage elicited by photo-oxidative stress, and that inhibition of their recruitment reduces photoreceptor death. Here, we look for functional insight into macrophage activity in this model through the spatiotemporal interplay of macrophage polarisation over the course of degeneration.Rats were exposed to 1000 lux light damage (LD for 24 hrs, with some left to recover for 3 and 7 days post-exposure. Expression and localisation of M1- and M2- macrophage markers was investigated in light-damaged retinas using qPCR, ELISA, flow cytometry, and immunohistochemistry.Expression of M1- (Ccl3, Il-6, Il-12, Il-1β, TNFα and M2- (CD206, Arg1, Igf1, Lyve1, Clec7a related markers followed discrete profiles following light damage; up-regulation of M1 genes peaked at the early phase of cell death, while M2 genes generally exhibited more prolonged increases during the chronic phase. Moreover, Il-1β and CD206 labelled accumulations of microglia/macrophages which differed in their morphological, temporal, and spatial characteristics following light damage.The data illustrate a dynamic shift in macrophage polarisation following light damage through a broad swathe of M1 and M2 markers. Pro-inflammatory M1 activation appears to dominate the early phase of degeneration while M2 responses appear to more heavily mark the chronic post-exposure period. While M1/M2 polarisation represents two extremes amongst a spectrum of macrophage activity, knowledge of their predominance offers insight into functional consequences of macrophage activity over the course of damage, which may inform the spatiotemporal employment of therapeutics in retinal disease.

  20. Photonic homeostatics

    Science.gov (United States)

    Liu, Timon C.; Li, Fan-Hui

    2010-11-01

    Photonic homeostatics is a discipline to study the establishment, maintenance, decay, upgrading and representation of function-specific homoestasis (FSH) by using photonics. FSH is a negative-feedback response of a biosystem to maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stress may increase sirtuin 1 (SIRT1) activities above FSH-specific SIRT1 activity to induce a function far from its FSH. On the one hand, low level laser irradiation or monochromatic light (LLL) can not modulate a function in its FSH or a stress in its stress-specific homeostasis (StSH), but modulate a function far from its FSH or a stress far from its StSH. On the other hand, the biophotons from a biosystem with its function in its FSH should be less than the one from the biosystem with its function far from its FSH. The non-resonant interaction of low intensity laser irradiation or monochromatic light (LIL) and a kind of membrane protein can be amplified by all the membrane proteins if the function is far from its FSH. This amplification might hold for biophoton emission of the membrane protein so that the photonic spectroscopy can be used to represent the function far from its FSH, which is called photonomics.

  1. Two-frequency picosecond laser based on composite vanadate crystals with {sigma}-polarised radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sirotkin, A A; Sadovskiy, S P; Garnov, Sergei V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2013-07-31

    A two-frequency picosecond laser based on {alpha}-cut Nd:YVO{sub 4}-YVO{sub 4} composite vanadate crystals is experimentally studied for the s-polarised radiation at the {sup 4}F{sub 3/2} - {sup 4}I{sub 11/2} transition with frequency tuning using Fabry-Perot etalons of different thickness. The difference between the radiation wavelengths was tuned within the range of 1.2-4.4 nm. In the mode-locking regime, the two-frequency radiation power was 280 mW at an absorbed pump power of 12 W. (lasers)

  2. Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised protons

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2015-05-01

    Full Text Available Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.

  3. Measurement of the Collins and Sivers asymmetries on transversely polarised protons

    CERN Document Server

    Alekseev, M G; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Austregesilo, A; Bade lek, B; Balestra, F; Ball, J; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, M P; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O Yu; Dhara, L; Diaz, V; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Efremov, A; El Alaoui, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M Jr; Fischer, H; Franco, C; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmüller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; von Harrach, D; Hasegawa, T; Heinsius, F H; Hermann, R; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Höppner, Ch; d'Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuß, E; Käfer, W; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konopka, R; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kowalik, K; Krämer, M; Kral, A; Kroumchtein, Z V; Kuhn, R; Kunne, F; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu V; Moinester, M A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J; Negrini, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Pawlukiewicz-Kaminska, B; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Quintans, C; Rajotte, J -F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Robinet, F; Rocco, E; Rondio, E; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Santos, H; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schl¨uter, T; Schmitt, L; Schopferer, S; Schröder, W; Shevchenko, O Yu; Siebert, H -W; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Takekawa, S; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Uhl, S; Uman, I; Virius, M; Vlassov, N V; Vossen, A; Weitzel, Q; Windmolders, R; Wìslicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhao, J; Zhuravlev, N; Zvyagin, A

    2010-01-01

    The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large values of the Bjorken x variable non-zero Collins asymmetries are observed both for positive and negative hadrons while the Sivers asymmetry for positive hadrons is slightly positive over almost all the measured x range. These results nicely support the present theoretical interpretation of these asymmetries, in terms of leading-twist quark distribution and fragmentation functions.

  4. Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

    CERN Document Server

    Adolph, C; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anosov, V; Austregesilo, A; Badełek, B; Balestra, F; Barth, J; Baum, G; Beck, R; Bedfer, Y; Berlin, A; Bernhard, J; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bodlak, M; Boer, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Büchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger jr , M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Gnesi, I; Gobbo, B; Goertz, S; Gorzellik, M; Grabmüller, S; Grasso, A; Grube, B; Grussenmeyer, T; Guskov, A; Guthörl, T; Haas, F; von Harrach, D; Hahne, D; Hashimoto, R; Heinsius, F H; Herrmann, F; Hinterberger, F; Höppner, Ch; Horikawa, N; d’Hose, N; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Jörg, P; Joosten, R; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Krämer, M; Kroumchtein, Z V; Kuchinski, N; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Marchand, C; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Miyachi, Y; Nagaytsev, A; Nagel, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Novy, J; Nowak, W -D; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Peshekhonov, D V; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Rocco, E; Rossiyskaya, N S; Ryabchikov, D I; Rychter, A; Samoylenko, V D; Sandacz, A; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlüter, T; Schmidt, K; Schmieden, H; Schönning, K; Schopferer, S; Schott, M; Shevchenko, O Yu; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; ter Wolbeek, J; Tessaro, S; Tessarotto, F; Thibaud, F; Uhl, S; Uman, I; Virius, M; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zink, A

    2015-01-01

    Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.

  5. Separation of coherent and incoherent scattering in liquid para-H{sub 2} by polarisation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Hernandez, M.; Mompean, F.J. [Madrid Univ. (Spain); Schaerpf, O.; Andersen, K.H. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Fak, B. [CEA Centre d`Etudes de Grenoble, 38 (France)

    1997-04-01

    In the 1960 IAEA Symposium on Neutron Scattering, Sarma presented his theoretical study on the scattering of cold neutrons by liquid hydrogen and demonstrated how the intimate coupling between nuclear and rotational degrees of freedom finally results in the possibility of observing collective modes from this material, which to many neutron scatterers is synonymous with `incoherent`. This problem is investigated with polarised neutrons to gain access to a limited region of the (Q,E) space where the collective response from this liquid is found. (author).

  6. Compact broadband circularly polarised slot antenna for universal UHF RFID readers

    DEFF Research Database (Denmark)

    Xu, Bo; Zhang, Shuai; Liu, Yusha

    2015-01-01

    A compact broadband circularly polarised (CP) slot antenna is designed for universal ultra-high-frequency (UHF) radio frequency identification (RFID) readers. The antenna consists of an L-shaped metal strip and a square-slot-loaded ground plane with four tuning stubs. The total size is 100 mm×100mm......×1.6 mm. The measured –10 dB impedance bandwidth is 40.7% (772–1166 MHz) and the measured 3 dB axial ratio (AR) bandwidth is 13.9% (840–965 MHz). Both the impedance and AR bandwidth cover the worldwide UHF RFID band....

  7. Macrophage polarisation: an immunohistochemical approach for identifying M1 and M2 macrophages.

    Directory of Open Access Journals (Sweden)

    Mário Henrique M Barros

    Full Text Available Macrophage polarization is increasingly recognised as an important pathogenetic factor in inflammatory and neoplastic diseases. Proinflammatory M1 macrophages promote T helper (Th 1 responses and show tumoricidal activity. M2 macrophages contribute to tissue repair and promote Th2 responses. CD68 and CD163 are used to identify macrophages in tissue sections. However, characterisation of polarised macrophages in situ has remained difficult. Macrophage polarisation is regulated by transcription factors, pSTAT1 and RBP-J for M1, and CMAF for M2. We reasoned that double-labelling immunohistochemistry for the detection of macrophage markers together with transcription factors may be suitable to characterise macrophage polarisation in situ. To test this hypothesis, we have studied conditions associated with Th1- and Th2-predominant immune responses: infectious mononucleosis and Crohn's disease for Th1 and allergic nasal polyps, oxyuriasis, wound healing and foreign body granulomas for predominant Th2 response. In all situations, CD163+ cells usually outnumbered CD68+ cells. Moreover, CD163+ cells, usually considered as M2 macrophages, co-expressing pSTAT1 and RBP-J were found in all conditions examined. The numbers of putative M1 macrophages were higher in Th1- than in Th2-associated diseases, while more M2 macrophages were seen in Th2- than in Th1 related disorders. In most Th1-related diseases, the balance of M1 over M2 cells was shifted towards M1 cells, while the reverse was observed for Th2-related conditions. Hierarchical cluster analysis revealed two distinct clusters: cluster I included Th1 diseases together with cases with high numbers of CD163+pSTAT1+, CD68+pSTAT1+, CD163+RBP-J+ and CD68+RBP-J+ macrophages; cluster II comprised Th2 conditions together with cases displaying high numbers of CD163+CMAF+ and CD68+CMAF+ macrophages. These results suggest that the detection of pSTAT1, RBP-J, and CMAF in the context of CD68 or CD163 expression is a

  8. Generation and analysis of correlated pairs of photons on board a nanosatellite

    Science.gov (United States)

    Chandrasekara, R.; Tang, Z.; Tan, Y. C.; Cheng, C.; Sha, L.; Hiang, G. C.; Oi, D.; Ling, A.

    2016-10-01

    Progress in quantum computers and their threat to conventional public key infrastructure is driving new forms of encryption. Quantum Key Distribution (QKD) using entangled photons is a promising approach. A global QKD network can be achieved using satellites equipped with optical links. Despite numerous proposals, actual experimental work demonstrating relevant entanglement technology in space is limited due to the prohibitive cost of traditional satellite development. To make progress, we have designed a photon pair source that can operate on modular spacecraft called CubeSats. We report the in-orbit operation of the photon pair source on board an orbiting CubeSat and demonstrate pair generation and polarisation correlation under space conditions. The in-orbit polarisation correlations are compatible with ground-based tests, validating our design. This successful demonstration is a major experimental milestone towards a space-based quantum network. Our approach provides a cost-effective method for proving the space-worthiness of critical components used in entangled photon technology. We expect that it will also accelerate efforts to probe the overlap between quantum and relativistic models of physics.

  9. Estimating Important Electrode Parameters of High Temperature PEM Fuel Cells By Fitting a Model to Polarisation Curves and Impedance Spectra

    DEFF Research Database (Denmark)

    Vang, Jakob Rabjerg; Zhou, Fan; Andreasen, Søren Juhl;

    2015-01-01

    A high temperature PEM (HTPEM) fuel cell model capable of simulating both steady state and dynamic operation is presented. The purpose is to enable extraction of unknown parameters from sets of impedance spectra and polarisation curves. The model is fitted to two polarisation curves and four...... impedance spectra measured on a Dapozol 77 MEA. The model is capable of achieving good agreement with the recorded curves. Except at OCV, where the voltage is overpredicted, the simulated polarisation curves deviate maximum 3.0% from the measurements. The impedance spectra deviate maximum 3.7%. The fitted...... parameter values are within the range reported in literature. The only exception is the catalyst layer acid content, which is an order of magnitude lower. This may derive from acid migration. The model is used to illustrate the effect of reactant dynamics on the impedance spectrum. The model can aid...

  10. Measurement of ψ(2S) polarisation in pp collisions at √(s) = 7 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Aaij, R. [Nikhef National Institute for Subatomic Physics, Amsterdam (Netherlands); Adeva, B. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain); Adinolfi, M. [University of Bristol, H.H. Wills Physics Laboratory, Bristol (United Kingdom); Collaboration: The LHCb Collaboration; and others

    2014-05-15

    The polarisation of prompt ψ(2S) mesons is measured by performing an angular analysis of ψ(2S) → μ{sup +}μ{sup -} decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb{sup -1}, collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum pT and rapidity y in the kinematic region 3.5 < p{sub T} < 15 GeV/c and 2.0 < y < 4.5, and is compared to theoretical models. No significant polarisation is observed. (orig.)

  11. Beam Steering at Higher Photonic Bands and Design of a Directional Cloak Formed by Photonic Crystals

    Directory of Open Access Journals (Sweden)

    Venkatachalam Subramanian

    2013-02-01

    Full Text Available Beam steering due to anomalous dispersion at higher photonic bands in dielectric photonic crystal is reported in this work. Based on this concept, directional cloak is designed that conceals a larger dimensional scattering object against the normal incident, linearly polarizedelectromagnetic waves.

  12. Linear optical implementation of optimal unambiguous discrimination among quantum states

    Institute of Scientific and Technical Information of China (English)

    Lu Jing; Zhou Lan; Kuang Le-Man

    2006-01-01

    In this paper, we present a linear optical scheme for optimal unambiguous discrimination among nonorthogonal quantum states in terms of the multiple-rail and polarization representation of a single photon. In our scheme, discriminated quantum states are expressed by using the spatial degree of freedom of a single photon while the polarization degree of freedom of the single photon is used to act as an auxiliary qubit. The optical components used in our scheme are only passive linear optical elements such as polarizing beam splitters, wave plates, polarizers, single photon detectors,and single photon source.

  13. Repeat-until-success linear optics distributed quantum computing.

    Science.gov (United States)

    Lim, Yuan Liang; Beige, Almut; Kwek, Leong Chuan

    2005-07-15

    We demonstrate the possibility to perform distributed quantum computing using only single-photon sources (atom-cavity-like systems), linear optics, and photon detectors. The qubits are encoded in stable ground states of the sources. To implement a universal two-qubit gate, two photons should be generated simultaneously and pass through a linear optics network, where a measurement is performed on them. Gate operations can be repeated until a success is heralded without destroying the qubits at any stage of the operation. In contrast with other schemes, this does not require explicit qubit-qubit interactions, a priori entangled ancillas, nor the feeding of photons into photon sources.

  14. The ubiquitous photonic wheel

    Science.gov (United States)

    Aiello, Andrea; Banzer, Peter

    2016-08-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its longitudinal spin angular momentum (AM) density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding transverse spin AM