Polarization speckles and generalized Stokes vector wave: a review [invited

DEFF Research Database (Denmark)

Takeda, Mitsuo; Wang, Wei; Hanson, Steen Grüner

2010-01-01

We review some of the statistical properties of polarization-related speckle phenomena, with an introduction of a less known concept of polarization speckles and their spatial degree of polarization. As a useful means to characterize twopoint vector field correlations, we review the generalized...... Stokes parameters proposed by Korotkova and Wolf, and introduce its time-domain representation to describe the space-time evolution of the correlation between random electric vector fields at two different space-time points. This time-domain generalized Stokes vector, with components similar to those...... of the beam coherence polarization matrix proposed by Gori, is shown to obey the wave equation in exact analogy to a coherence function of scalar fields. Because of this wave nature, the time-domain generalized Stokes vector is referred to as generalized Stokes vector wave in this paper....

Polarization properties of linearly polarized parabolic scaling Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Guo, Mengwen; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

2016-10-07

The intensity profiles for the dominant polarization, cross polarization, and longitudinal components of modified parabolic scaling Bessel beams with linear polarization are investigated theoretically. The transverse intensity distributions of the three electric components are intimately connected to the topological charge. In particular, the intensity patterns of the cross polarization and longitudinal components near the apodization plane reflect the sign of the topological charge. - Highlights: • We investigated the polarization properties of modified parabolic scaling Bessel beams with linear polarization. • We studied the evolution of transverse intensity profiles for the three components of these beams. • The intensity patterns of the cross polarization and longitudinal components can reflect the sign of the topological charge.

Spin physics with polarized electrons at the SLC [Stanford Linear Collider

International Nuclear Information System (INIS)

Moffeit, K.C.

1990-11-01

The Stanford Linear Collider was designed to accommodate polarized electron beams. A gallium arsenide-based photon emission source will provide a beam of longitudinally polarized electrons of about 40 percent polarization. A system of bend magnets and a superconducting solenoid will be used to rotate the spins so that the polarization is preserved while the 1.21 GeV electrons are stored in the damping ring. Another set of bend magnets and two superconducting solenoids orient the spin vectors so that longitudinal polarization of the electrons is achieved at the collision point with the unpolarized positions. A system to monitor the polarization based on Moeller and Compton scattering will be used. Spin physics with longitudinally polarized electrons uses the measurement of the left-right asymmetry to provide tests of the Standard Model. The uncertainty in the measurement is precise enough to be sensitive to the effects of particles which can not be produced directly in the machines we have today. 5 refs

Interior point decoding for linear vector channels

International Nuclear Information System (INIS)

Wadayama, T

2008-01-01

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem

Interior point decoding for linear vector channels

Energy Technology Data Exchange (ETDEWEB)

Wadayama, T [Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, Aichi, 466-8555 (Japan)], E-mail: wadayama@nitech.ac.jp

2008-01-15

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem.

Polarized Electrons for Linear Colliders

International Nuclear Information System (INIS)

Clendenin, J.

2004-01-01

Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%

Vectorial structures of linear-polarized Butterfly-Gauss vortex beams in the far zone

Science.gov (United States)

Cheng, Ke; Zhou, Yan; Lu, Gang; Yao, Na; Zhong, Xianqiong

2018-05-01

By introducing the Butterfly catastrophe to optics, the far-zone vectorial structures of Butterfly-Gauss beam with vortex and non-vortex are studied using the angular spectrum representation and stationary phase method. The influence of topological charge, linear-polarized angle, off-axis distance and scaling length on the far-zone vectorial structures, especially in the Poynting vector and angular momentum density of the corresponding beam is emphasized. The results show that the embedded optical vortex at source plane lead to special dark zones in the far zone, where the number of dark zone equals the absolute value of topological charge of optical vortex. Furthermore, the symmetry and direction of the special dark zones can be controlled by off-axis distance and scaling length, respectively. The linear-polarized angle adjusts only the Poynting vectors of TE and TM terms, but it does not affect those of whole beam. Finally, the vectorial expressions also indicate that the total angular momentum density is certainly zero owing to the far-zone stable structures rather than rotation behaviors.

Linearly and circularly polarized laser photoinduced molecular order in azo dye doped polymer films

Directory of Open Access Journals (Sweden)

Saad Bendaoud

2017-01-01

Full Text Available Photo-induced behavior of Azo Disperse one (AZD1 doped Poly(Methyl MethAcrylate (PMMA using both linear and circular polarized light is studied. The anisotropy is not erased by the circular polarization light. The circular polarization light combined with relatively long lifetime of the cis state in azo dye doped polymers activate all transverse directions of the angular hole burning through the spot in the film inducing anisotropy. Under circular polarized light, there is no orientation perpendicularly to the helex described by the rotating electric field vector, trans molecules reorients in the propagation direction of the pump beam. The polarization state of the probe beam after propagation through the pumped spot depends strongly on the angle of incidence of both pump and probe beams on the input face. In the case where circular polarized pump and probe beams are under the same angle of incidence, the probe beam “sees” anisotropic film as if it is isotropic. Results of this work shows the possibility to reorient azobenzene-type molecules in two orthogonal directions using alternately linearly and circularly polarized beams.

Vector Monte Carlo simulations on atmospheric scattering of polarization qubits.

Science.gov (United States)

Li, Ming; Lu, Pengfei; Yu, Zhongyuan; Yan, Lei; Chen, Zhihui; Yang, Chuanghua; Luo, Xiao

2013-03-01

In this paper, a vector Monte Carlo (MC) method is proposed to study the influence of atmospheric scattering on polarization qubits for satellite-based quantum communication. The vector MC method utilizes a transmittance method to solve the photon free path for an inhomogeneous atmosphere and random number sampling to determine whether the type of scattering is aerosol scattering or molecule scattering. Simulations are performed for downlink and uplink. The degrees and the rotations of polarization are qualitatively and quantitatively obtained, which agree well with the measured results in the previous experiments. The results show that polarization qubits are well preserved in the downlink and uplink, while the number of received single photons is less than half of the total transmitted single photons for both links. Moreover, our vector MC method can be applied for the scattering of polarized light in other inhomogeneous random media.

Calibration of the degree of linear polarization measurements of the polarized Sun-sky radiometer based on the POLBOX system.

Science.gov (United States)

Li, Zhengqiang; Li, Kaitao; Li, Li; Xu, Hua; Xie, Yisong; Ma, Yan; Li, Donghui; Goloub, Philippe; Yuan, Yinlin; Zheng, Xiaobing

2018-02-10

Polarization observation of sky radiation is the frontier approach to improve the remote sensing of atmospheric components, e.g., aerosol and clouds. The polarization calibration of the ground-based Sun-sky radiometer is the basis for obtaining accurate degree of linear polarization (DOLP) measurement. In this paper, a DOLP calibration method based on a laboratory polarized light source (POLBOX) is introduced in detail. Combined with the CE318-DP Sun-sky polarized radiometer, a calibration scheme for DOLP measurement is established for the spectral range of 440-1640 nm. Based on the calibration results of the Sun-sky radiometer observation network, the polarization calibration coefficient and the DOLP calibration residual are analyzed statistically. The results show that the DOLP residual of the calibration scheme is about 0.0012, and thus it can be estimated that the final DOLP calibration accuracy of this method is about 0.005. Finally, it is verified that the accuracy of the calibration results is in accordance with the expected results by comparing the simulated DOLP with the vector radiative transfer calculations.

Broad-aperture polarized proton target with arbitrary orientation of polarization vector

International Nuclear Information System (INIS)

Belyaev, A.A.; Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporov, E.A.; Telegin, Yu.N.; Trotsenko, V.I.

1985-01-01

Polarized proton target with the Helmholtz broad-aperture superconducting magnetic system is described. Axial aperture α=95 deg, inter-coil access angle β=23 deg. The structure of the target allows various versions of the installation what make sure an arbitrary orientation of polarization vector. The 0.1 W cold output 3 He evaporation cryostat was used to obtain the work temperature 0.5 K allowing quick transformation to a 3 He- 4 He dilution refrigerator. Results of the study are given on the dynamical proton polarization in 1,2-propylenglycol with various stable Cr 5 complexes

Polarization Control with Plasmonic Antenna Tips: A Universal Approach to Optical Nanocrystallography and Vector-Field Imaging

Science.gov (United States)

Park, Kyoung-Duck; Raschke, Markus B.

2018-05-01

Controlling the propagation and polarization vectors in linear and nonlinear optical spectroscopy enables to probe the anisotropy of optical responses providing structural symmetry selective contrast in optical imaging. Here we present a novel tilted antenna-tip approach to control the optical vector-field by breaking the axial symmetry of the nano-probe in tip-enhanced near-field microscopy. This gives rise to a localized plasmonic antenna effect with significantly enhanced optical field vectors with control of both \\textit{in-plane} and \\textit{out-of-plane} components. We use the resulting vector-field specificity in the symmetry selective nonlinear optical response of second-harmonic generation (SHG) for a generalized approach to optical nano-crystallography and -imaging. In tip-enhanced SHG imaging of monolayer MoS$_2$ films and single-crystalline ferroelectric YMnO$_3$, we reveal nano-crystallographic details of domain boundaries and domain topology with enhanced sensitivity and nanoscale spatial resolution. The approach is applicable to any anisotropic linear and nonlinear optical response, and provides for optical nano-crystallographic imaging of molecular or quantum materials.

Vectorized Matlab Codes for Linear Two-Dimensional Elasticity

Directory of Open Access Journals (Sweden)

Jonas Koko

2007-01-01

Full Text Available A vectorized Matlab implementation for the linear finite element is provided for the two-dimensional linear elasticity with mixed boundary conditions. Vectorization means that there is no loop over triangles. Numerical experiments show that our implementation is more efficient than the standard implementation with a loop over all triangles.

Linear polarization of BY Draconis

International Nuclear Information System (INIS)

Koch, R.H.; Pfeiffer, R.J.

1976-01-01

Linear polarization measurements are reported in four bandpasses for the flare star BY Dra. The red polarization is intrinsically variable at a confidence level greater than 99 percent. On a time scale of many months, the variability is not phase-locked to either a rotational or a Keplerian ephemeris. The observations of the three other bandpasses are useful principally to indicate a polarization spectrum rising toward shorter wavelengths

Hyperbolic-symmetry vector fields.

Science.gov (United States)

Gao, Xu-Zhen; Pan, Yue; Cai, Meng-Qiang; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

2015-12-14

We present and construct a new kind of orthogonal coordinate system, hyperbolic coordinate system. We present and design a new kind of local linearly polarized vector fields, which is defined as the hyperbolic-symmetry vector fields because the points with the same polarization form a series of hyperbolae. We experimentally demonstrate the generation of such a kind of hyperbolic-symmetry vector optical fields. In particular, we also study the modified hyperbolic-symmetry vector optical fields with the twofold and fourfold symmetric states of polarization when introducing the mirror symmetry. The tight focusing behaviors of these vector fields are also investigated. In addition, we also fabricate micro-structures on the K9 glass surfaces by several tightly focused (modified) hyperbolic-symmetry vector fields patterns, which demonstrate that the simulated tightly focused fields are in good agreement with the fabricated micro-structures.

Properties of asymmetry of the electro disintegration process with vector-polarized deuterons

CERN Document Server

Rekalo, M P; Rekalo, O P

2002-01-01

The properties of the asymmetry A sub y (theta) in the exclusive electro disintegration of vector-polarized deuteron d-vector (e, e' p)n have been investigated (the vector of the target polarization is directed perpendicularly to the plane of the reaction gamma sup * + d-vector -> n + p). All calculations have been done in the framework of relativistic impulse approximation with the unitarized multipole gamma sup * + d-vector -> n + p amplitudes in order to account the final-state NN interaction in the reaction d-vector (e, e' p)n. The significance of various mechanisms in the formation of the angular dependence of the asymmetry A sub y (theta) has been discussed for the complanar kinematical conditions.

An introduction to vectors, vector operators and vector analysis

CERN Document Server

Joag, Pramod S

2016-01-01

Ideal for undergraduate and graduate students of science and engineering, this book covers fundamental concepts of vectors and their applications in a single volume. The first unit deals with basic formulation, both conceptual and theoretical. It discusses applications of algebraic operations, Levi-Civita notation, and curvilinear coordinate systems like spherical polar and parabolic systems and structures, and analytical geometry of curves and surfaces. The second unit delves into the algebra of operators and their types and also explains the equivalence between the algebra of vector operators and the algebra of matrices. Formulation of eigen vectors and eigen values of a linear vector operator are elaborated using vector algebra. The third unit deals with vector analysis, discussing vector valued functions of a scalar variable and functions of vector argument (both scalar valued and vector valued), thus covering both the scalar vector fields and vector integration.

Vector meson photoproduction with a linearly polarized beam

Science.gov (United States)

Mathieu, V.; Nys, J.; Fernández-Ramírez, C.; Jackura, A.; Pilloni, A.; Sherrill, N.; Szczepaniak, A. P.; Fox, G.; Joint Physics Analysis Center

2018-05-01

We propose a model based on Regge theory to describe photoproduction of light vector mesons. We fit the SLAC data and make predictions for the energy and momentum-transfer dependence of the spin-density matrix elements in photoproduction of ω , ρ0 and ϕ mesons at Eγ˜8.5 GeV , which are soon to be measured at Jefferson Lab.

Polarized electron sources for linear colliders

International Nuclear Information System (INIS)

Clendenin, J.E.; Ecklund, S.D.; Miller, R.H.; Schultz, D.C.; Sheppard, J.C.

1992-07-01

Linear colliders require high peak current beams with low duty factors. Several methods to produce polarized e - beams for accelerators have been developed. The SLC, the first linear collider, utilizes a photocathode gun with a GaAs cathode. Although photocathode sources are probably the only practical alternative for the next generation of linear colliders, several problems remain to be solved, including high voltage breakdown which poisons the cathode, charge limitations that are associated with the condition of the semiconductor cathode, and a relatively low polarization of ≤5O%. Methods to solve or at least greatly reduce the impact of each of these problems are at hand

Small-angle neutron polarization for the 2H(d vector,n vector)3He reaction near Esub(d) = 8MeV

International Nuclear Information System (INIS)

Tornow, W.; Woye, W.; Mack, G.

1981-01-01

Considerable improvement in the quality of analyzing power experiments performed with polarized fast neutrons has been achieved during the last few years by using neutrons from the polarization transfer reaction 2 H(d vector,n vector) 3 He at a reaction angle of theta = 0 0 . To compromise in these experiments between intensity problems and finite geometry corrections, it is desirable in some instances to subtend a full-width angle Δtheta of 20 0 (lab) centered about theta = 0 0 . In order to investigate the suitability of this reaction as a source of polarized neutrons for cases where the scatterer is close to the neutron source, the neutron polarization of the reaction 2 H(d vector,n vector) 3 He has been studied with Δtheta of about 3 0 in 3 0 steps out to theta = 20 0 (lab). An incident deuteron energy near 8 MeV was chosen to yield outgoing neutrons at 11.0 MeV, a typical energy for neutron analyzing power experiments. It is found that the effective neutron polarization, a combination of the two polarizations measured when the direction of the deuteron polarization is inverted or flipped at the polarized ion source, is large and nearly constant for angles between theta = 0 0 and theta = 10 0 (lab). (orig.)

Vector-Sensor MUSIC for Polarized Seismic Sources Localization

Directory of Open Access Journals (Sweden)

Jérôme I. Mars

2005-01-01

Full Text Available This paper addresses the problem of high-resolution polarized source detection and introduces a new eigenstructure-based algorithm that yields direction of arrival (DOA and polarization estimates using a vector-sensor (or multicomponent-sensor array. This method is based on separation of the observation space into signal and noise subspaces using fourth-order tensor decomposition. In geophysics, in particular for reservoir acquisition and monitoring, a set of Nx-multicomponent sensors is laid on the ground with constant distance Δx between them. Such a data acquisition scheme has intrinsically three modes: time, distance, and components. The proposed method needs multilinear algebra in order to preserve data structure and avoid reorganization. The data is thus stored in tridimensional arrays rather than matrices. Higher-order eigenvalue decomposition (HOEVD for fourth-order tensors is considered to achieve subspaces estimation and to compute the eigenelements. We propose a tensorial version of the MUSIC algorithm for a vector-sensor array allowing a joint estimation of DOA and signal polarization estimation. Performances of the proposed algorithm are evaluated.

A novel orthogonally linearly polarized Nd:YVO4 laser

International Nuclear Information System (INIS)

Xing-Peng, Yan; Qiang, Liu; Hai-Long, Chen; Xing, Fu; Ma-Li, Gong; Dong-Sheng, Wang

2010-01-01

We presented a novel orthogonally linearly polarized Nd:YVO 4 laser. Two pieces of α-cut grown-together composite YVO 4 /Nd:YVO 4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM 00 laser was obtained, and the beam quality factors were M x 2 = 1.37 and M y 2 = 1.25. (classical areas of phenomenology)

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background.

Science.gov (United States)

Abbott, B P; Abbott, R; Abbott, T D; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V B; Affeldt, C; Afrough, M; Agarwal, B; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Aiello, L; Ain, A; Ajith, P; Allen, B; Allen, G; Allocca, A; Altin, P A; Amato, A; Ananyeva, A; Anderson, S B; Anderson, W G; Angelova, S V; Antier, S; Appert, S; Arai, K; Araya, M C; Areeda, J S; Arnaud, N; Ascenzi, S; Ashton, G; Ast, M; Aston, S M; Astone, P; Atallah, D V; Aufmuth, P; Aulbert, C; AultONeal, K; Austin, C; Avila-Alvarez, A; Babak, S; Bacon, P; Bader, M K M; Bae, S; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Banagiri, S; Barayoga, J C; Barclay, S E; Barish, B C; Barker, D; Barkett, K; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barta, D; Bartlett, J; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bawaj, M; Bayley, J C; Bazzan, M; Bécsy, B; Beer, C; Bejger, M; Belahcene, I; Bell, A S; Berger, B K; Bergmann, G; Bero, J J; Berry, C P L; Bersanetti, D; Bertolini, A; 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2018-05-18

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

Science.gov (United States)

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S.; Kasprzack, M.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kéfélian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, K.; Kim, W.; Kim, W. S.; Kim, Y.-M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kinley-Hanlon, M.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Knowles, T. D.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Krämer, C.; Kringel, V.; Królak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Linker, S. D.; Littenberg, T. B.; Liu, J.; Lo, R. K. L.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macas, R.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña Hernandez, I.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markakis, C.; Markosyan, A. S.; Markowitz, A.; Maros, E.; Marquina, A.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Mason, K.; Massera, E.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McNeill, L.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Mehmet, M.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, B. B.; Miller, J.; Millhouse, M.; Milovich-Goff, M. C.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moffa, D.; Moggi, A.; Mogushi, K.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muñiz, E. A.; Muratore, M.; Murray, P. G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Neilson, J.; Nelemans, G.; Nelson, T. J. N.; Nery, M.; Neunzert, A.; Nevin, L.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; North, C.; Nuttall, L. K.; Oberling, J.; O'Dea, G. D.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Okada, M. A.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ossokine, S.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, Howard; Pan, Huang-Wei; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Parida, A.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patil, M.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pirello, M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Pratten, G.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rajbhandari, B.; Rakhmanov, M.; Ramirez, K. E.; Ramos-Buades, A.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Ren, W.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosińska, D.; Ross, M. P.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Rutins, G.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sanchez, L. E.; Sanchis-Gual, N.; Sandberg, V.; Sanders, J. R.; Sassolas, B.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheel, M.; Scheuer, J.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A. A.; Shahriar, M. S.; Shaner, M. B.; Shao, L.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, L. P.; Singh, A.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Smith, R. J. E.; Somala, S.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staats, K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stevenson, S. P.; Stone, R.; Stops, D. J.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Strunk, A.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Suresh, J.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Tait, S. C.; Talbot, C.; Talukder, D.; Tanner, D. B.; Tao, D.; Tápai, M.; Taracchini, A.; Tasson, J. D.; Taylor, J. A.; Taylor, R.; Tewari, S. V.; Theeg, T.; Thies, F.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torres-Forné, A.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tsukada, L.; Tsuna, D.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasúth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Viceré, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, W. H.; Wang, Y. F.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Weßels, P.; Westerweck, J.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Wilken, D.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, K. W. K.; Worden, J.; Wright, J. L.; Wu, D. S.; Wysocki, D. M.; Xiao, S.; Yamamoto, H.; Yancey, C. C.; Yang, L.; Yap, M. J.; Yazback, M.; Yu, Hang; Yu, Haocun; Yvert, M.; ZadroŻny, A.; Zanolin, M.; Zelenova, T.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y.-H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

2018-05-01

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58 ×10-8 , Ω0V<6.35 ×10-8 , and Ω0S<1.08 ×10-7 at a reference frequency f0=25 Hz .

Modeling and parameterization of photoelectrons emitted in condensed matter by linearly polarized synchrotron radiation

Science.gov (United States)

Jablonski, A.

2018-01-01

Growing availability of synchrotron facilities stimulates an interest in quantitative applications of hard X-ray photoemission spectroscopy (HAXPES) using linearly polarized radiation. An advantage of this approach is the possibility of continuous variation of radiation energy that makes it possible to control the sampling depth for a measurement. Quantitative applications are based on accurate and reliable theory relating the measured spectral features to needed characteristics of the surface region of solids. A major complication in the case of polarized radiation is an involved structure of the photoemission cross-section for hard X-rays. In the present work, details of the relevant formalism are described and algorithms implementing this formalism for different experimental configurations are proposed. The photoelectron signal intensity may be considerably affected by variation in the positioning of the polarization vector with respect to the surface plane. This information is critical for any quantitative application of HAXPES by polarized X-rays. Different quantitative applications based on photoelectrons with energies up to 10 keV are considered here: (i) determination of surface composition, (ii) estimation of sampling depth, and (iii) measurements of an overlayer thickness. Parameters facilitating these applications (mean escape depths, information depths, effective attenuation lengths) were calculated for a number of photoelectron lines in four elemental solids (Si, Cu, Ag and Au) in different experimental configurations and locations of the polarization vector. One of the considered configurations, with polarization vector located in a plane perpendicular to the surface, was recommended for quantitative applications of HAXPES. In this configurations, it was found that the considered parameters vary weakly in the range of photoelectron emission angles from normal emission to about 50° with respect to the surface normal. The averaged values of the mean

Measurement of Charmless B to Vector-Vector decays at BaBar

International Nuclear Information System (INIS)

Olaiya, Emmanuel

2011-01-01

The authors present results of B → vector-vector (VV) and B → vector-axial vector (VA) decays B 0 → φX(X = φ,ρ + or ρ 0 ), B + → φK (*)+ , B 0 → K*K*, B 0 → ρ + b 1 - and B + → K* 0 α 1 + . The largest dataset used for these results is based on 465 x 10 6 Υ(4S) → B(bar B) decays, collected with the BABAR detector at the PEP-II B meson factory located at the Stanford Linear Accelerator Center (SLAC). Using larger datasets, the BABAR experiment has provided more precise B → VV measurements, further supporting the smaller than expected longitudinal polarization fraction of B → φK*. Additional B meson to vector-vector and vector-axial vector decays have also been studied with a view to shedding light on the polarization anomaly. Taking into account the available errors, we find no disagreement between theory and experiment for these additional decays.

Polarized electronic sources for future e+/e- linear colliders

International Nuclear Information System (INIS)

Tang, H.; Alley, R.K.; Clendenin, J.E.

1997-05-01

Polarized electron beams will play a crucial role in maximizing the physics potential for future e + /e - linear colliders. We will review the SLC polarized electron source (PES), present a design for a conventional PES for the Next Linear Collider (NLC), and discuss the physics issues of a polarized RF gun

Sources of linear polarized x-rays

International Nuclear Information System (INIS)

Aiginger, H.; Wobrauschek, P.

1989-01-01

Linear polarized X-rays are used in X-ray fluorescence analysis to decrease the background caused by scattered photons. Various experiments, calculations and constructions have demonstrated the possibility to produce polarized radiation in an analytical laboratory with an X-ray tube and polarizer-analyzer facilities as auxiliary equipment. The results obtained with Bragg-polarizers of flat and curved focussing geometry and of Barkla-polarizers are presented. The advantages and disadvantages of the method are discussed and compared with the respective quality of synchrotron radiation. Polarization by scattering reduces the intensity of the primary radiation. Recently much effort is devoted to the construction of integrated high power X-ray tube polarizer-analyzer arrangements. The detailed design, geometry and performance of such a facility is described. (author)

MEASUREMENT OF POLARIZATION OBSERVABLES IN VECTOR MESON PHOTOPRODUCTION USING A TRANSVERSELY-POLARIZED FROZEN-SPIN TARGET AND POLARIZED PHOTONS AT CLAS, JEFFERSON LAB

Energy Technology Data Exchange (ETDEWEB)

Roy, Priyashree [Florida State Univ., Tallahassee, FL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-11-30

The study of baryon resonances provides a deeper understanding of the strong interaction because the dynamics and relevant degrees of freedom hidden within them are re ected by the properties of the excited states of baryons. Higher-lying excited states at and above 1.7 GeV/c2 are generally predicted to have strong couplings to final states involving a heavier meson, e. g. one of the vector mesons, ρ, ω φ, as compared to a lighter pseudoscalar meson, e. g. π and η. Decays to the ππΝ final states via πΔ also become more important through the population of intermediate resonances. We observe that nature invests in mass rather than momentum. The excited states of the nucleon are usually found as broadly overlapping resonances which may decay into a multitude of final states involving mesons and baryons. Polarization observables make it possible to isolate single resonance contributions from other interference terms. The CLAS g9 (FROST) experiment, as part of the N* spectroscopy program at Je?erson Laboratory, accumulated photoproduction data using circularly- & linearly-polarized photons incident on a transversely-polarized butanol target (g9b experiment) in the photon energy range 0:3-2:4 GeV & 0:7-2:1 GeV, respectively. In this work, the analysis of reactions and polarization observables which involve two charged pions, either in the fully exclusive reaction γρ -> ρπ+π- or in the semi-exclusive reaction with a missing neutral pion, γρ -> ρπ+π-(π0) will be presented. For the reaction ρπ+π-, eight polarization observables (Is, Ic, Px, Py, Psx; y, Pcx; y) have been extracted. The high statistics data rendered it possible to extract these observables in three dimensions. All of them are first-time measurements. The fairly good agreement of Is, Ic obtained from this analysis with the experimental results from a previous CLAS experiment provides support for the first-time measurements. For the reaction γρ -> ρω -> ρπ+π(π0, five polarization

Polarization observables D/sub NN/, P and A for vector pp → vector pπ+n at 800 MeV

International Nuclear Information System (INIS)

Bonner, B.E.; McNaughton, M.W.; van Dyck, O.B.

1983-01-01

In conjunction with a vector polarization transfer measurement in the vector pp → vector dπ + reaction, we also obtained data on polarization observables for vector pp → vector pπ + n at 800 MeV incident proton energy. Scattered protons were detected in a spectrometer at angles from 5 0 to 11 0 . Pions were detected in coincidence at angles 80 0 to 130 0 . The proton momentum range covered was from 800 to 1300 MeV/c. The prominent peak observed near 1150 MeV/c in the proton spectrum is a reflection of Δ ++ production at center of mass angles from 0 0 to 30 0 . Regions of the spectrum corresponding to Δ ++ production at backward THETA/sub cm/ angles and to the 1 S 0 np final state interaction fall below the momentum acceptance limit for the spectrometer setting used in the present measurements. The events were binned into five proton momentum bins for the determination of the polarization observables D/sub NN/, P, and A

Transverse spin in the scattering of focused radially and azimuthally polarized vector beams

Science.gov (United States)

Singh, Ankit Kumar; Saha, Sudipta; Gupta, Subhasish Dutta; Ghosh, Nirmalya

2018-04-01

We study the effect of focusing of the radially and azimuthally polarized vector beams on the spin angular momentum (SAM) density and Poynting vector of scattered waves from a Mie particle. Remarkably, the study reveals that the SAM density of the scattered field is solely transverse in nature for radially and azimuthally polarized incident vector beams; however, the Poynting vector shows the usual longitudinal character. We also demonstrate that the transverse SAM density can further be tuned with wavelength and focusing of the incident beam by exploiting the interference of different scattering modes. These results may stimulate further experimental techniques to detect the transverse spin and Belinfante's spin-momentum densities.

Optical vector network analyzer with improved accuracy based on polarization modulation and polarization pulling.

Science.gov (United States)

Li, Wei; Liu, Jian Guo; Zhu, Ning Hua

2015-04-15

We report a novel optical vector network analyzer (OVNA) with improved accuracy based on polarization modulation and stimulated Brillouin scattering (SBS) assisted polarization pulling. The beating between adjacent higher-order optical sidebands which are generated because of the nonlinearity of an electro-optic modulator (EOM) introduces considerable error to the OVNA. In our scheme, the measurement error is significantly reduced by removing the even-order optical sidebands using polarization discrimination. The proposed approach is theoretically analyzed and experimentally verified. The experimental results show that the accuracy of the OVNA is greatly improved compared to a conventional OVNA.

Small-angle neutron polarization for the /sup 2/H(d vector,n vector)/sup 3/He reaction near Esub(d) = 8MeV

Energy Technology Data Exchange (ETDEWEB)

Tornow, W.; Woye, W.; Mack, G. (Tuebingen Univ. (Germany, F.R.). Physikalisches Inst.); Walter, R.L.; Floyd, C.E.; Guss, P.P.; Byrd, R.C. (Duke Univ., Durham, NC (USA). Dept. of Physics; Triangle Universities Nuclear Lab., Durham, NC (USA))

1981-12-15

Considerable improvement in the quality of analyzing power experiments performed with polarized fast neutrons has been achieved during the last few years by using neutrons from the polarization transfer reaction /sup 2/H(d vector,n vector)/sup 3/He at a reaction angle of theta = 0/sup 0/. To compromise in these experiments between intensity problems and finite geometry corrections, it is desirable in some instances to subtend a full-width angle ..delta..theta of 20/sup 0/ (lab) centered about theta = 0/sup 0/. In order to investigate the suitability of this reaction as a source of polarized neutrons for cases where the scatterer is close to the neutron source, the neutron polarization of the reaction /sup 2/H(d vector,n vector)/sup 3/He has been studied with ..delta..theta of about 3/sup 0/ in 3/sup 0/ steps out to theta = 20/sup 0/ (lab). An incident deuteron energy near 8 MeV was chosen to yield outgoing neutrons at 11.0 MeV, a typical energy for neutron analyzing power experiments. It is found that the effective neutron polarization, a combination of the two polarizations measured when the direction of the deuteron polarization is inverted or flipped at the polarized ion source, is large and nearly constant for angles between theta = 0/sup 0/ and theta = 10/sup 0/ (lab).

Polarized positrons and electrons at the linear collider

International Nuclear Information System (INIS)

Moortgat-Pick, G.; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke, J.; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Dreiner, H.K.; Eberl, H.; Ellis, J.

2008-01-01

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization

Linear polarizers based on oriented polymer blends

NARCIS (Netherlands)

Jagt, H.J.B.; Dirix, Y.J.L.; Hikmet, R.A.M.; Bastiaansen, C.W.M.

1998-01-01

Linear sheet polarizers based on the anisotropic scattering of light by drawn polymer blends are introduced here. The proper selection of materials and processing conditions for the production of large-area, flexible films of phase-segregated polymer blends suitable for polarization applications are

Time-of-flight and vector polarization analysis for diffuse neutron scattering

International Nuclear Information System (INIS)

Schweika, W.

2003-01-01

The potential of pulsed neutron sources for diffuse scattering including time-of-flight (TOF) and polarization analysis is discussed in comparison to the capabilities of the present instrument diffuse neutron scattering at the research center Juelich. We present first results of a new method for full polarization analysis using precessing neutron polarization. A proposal is made for a new type of instrument at pulsed sources, which allows for vector polarization analysis in TOF instruments with multi-detectors

Direct Probes of Linearly Polarized Gluons inside Unpolarized Hadrons

NARCIS (Netherlands)

Boer, D.; Brodsky, S. J.; Mulders, P.J.G.; Pisano, C.

2011-01-01

We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos2 asymmetries and estimate their maximal value, concluding that measurements of the unknown linearly polarized

Wavelength Dependence of the Polarization Singularities in a Two-Mode Optical Fiber

Directory of Open Access Journals (Sweden)

V. V. G. Krishna Inavalli

2012-01-01

Full Text Available We present here an experimental demonstration of the wavelength dependence of the polarization singularities due to linear combination of the vector modes excited directly in a two-mode optical fiber. The coherent superposition of the vector modes excited by linearly polarized Gaussian beam as offset skew rays propagated in a helical path inside the fiber results in the generation of phase singular beams with edge dislocation in the fiber output. The polarization character of these beams is found to change dramatically with wavelength—from left-handed elliptically polarized edge dislocation to right-handed elliptically polarized edge-dislocation through disclinations. The measured behaviour is understood as being due to intermodal dispersion of the polarization corrections to the propagating vector modes, as the wavelength of the input beam is scanned.

Measurement of the Asymmetry of Photoproduction of π- Mesons on Linearly Polarized Deuterons by Linearly Polarized Photons

Science.gov (United States)

Gauzshtein, V. V.; Zevakov, S. A.; Levchuk, M. I.; Loginov, A. Yu.; Nikolenko, D. M.; Rachek, I. A.; Sadykov, R. Sh.; Toporkov, D. K.; Shestakov, Yu. V.

2018-05-01

The first results of a double polarization experiment to extract the asymmetry of the reaction of photoproduction of a π- meson by a linearly polarized photon on a tensor-polarized deuteron in the energy range of the virtual photon (300-700 MeV) are presented. The measurements were performed on an internal tensor-polarized deuterium target in the VEPP-3 electron-positron storage ring for the electron beam energy equal to 2 GeV. The experiment employed the method of recording two protons and the scattered electron in coincidence. The obtained measurement results are compared with the theoretical predictions obtained in the momentum approximation with allowance for πN and NN rescattering in the final state.

Electromagnetic frozen waves with radial, azimuthal, linear, circular, and elliptical polarizations

Science.gov (United States)

Corato-Zanarella, Mateus; Zamboni-Rached, Michel

2016-11-01

Frozen waves (FWs) are a class of diffraction- and attenuation-resistant beams whose intensity pattern along the direction of propagation can be chosen arbitrarily, thus making them relevant for engineering the spatial configuration of optical fields. To date, analyses of such beams have been done essentially for the scalar case, with the vectorial nature of the electromagnetic fields often neglected. Although it is expected that the field components keep the fundamental properties of the scalar FWs, a deeper understanding of their electromagnetic counterparts is mandatory in order to exploit their different possible polarization states. The purpose of this paper is to study the properties of electromagnetic FWs with radial, azimuthal, linear, circular, and elliptical polarizations under paraxial and nonparaxial regimes in nonabsorbing media. An intensity pattern is chosen for a scalar FW, and the vectorial solutions are built after it via the use of Maxwell's equations. The results show that the field components and the longitudinal component of the time-averaged Poynting vector closely follow the pattern chosen even under highly nonparaxial conditions, showing the robustness of the FW structure to parameters variations.

Linear polarization-discriminatory state inverter fabricated by oblique angle deposition.

Science.gov (United States)

Park, Yong Jun; Sobahan, K M A; Kim, Jin Joo; Hwangbo, Chang Kwon

2009-06-22

In this paper, we report a linear polarization-discriminatory state inverter made of three-layer sculpture thin film fabricated by oblique angle deposition technique. The first and third layers are quarter-wave plates of zigzag structure and the middle of them is a circular Bragg reflector of left-handed helical structure. It is found that the normal incidence of P-polarized light on this polarization-discriminatory state inverter becomes the S-polarized light at output, while the incident S-polarized light of wavelength lying in the Bragg regime is reflected. The microstructure of the linear polarization-discriminatory state inverter is also investigated by using a scanning electron microscope.

Linear Polarization, Circular Polarization, and Depolarization of Gamma-ray Bursts: A Simple Case of Jitter Radiation

Energy Technology Data Exchange (ETDEWEB)

Mao, Jirong; Wang, Jiancheng, E-mail: jirongmao@mail.ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, 650011 Kunming, Yunnan Province (China)

2017-04-01

Linear and circular polarizations of gamma-ray bursts (GRBs) have been detected recently. We adopt a simplified model to investigate GRB polarization characteristics in this paper. A compressed two-dimensional turbulent slab containing stochastic magnetic fields is considered, and jitter radiation can produce the linear polarization under this special magnetic field topology. Turbulent Faraday rotation measure (RM) of this slab makes strong wavelength-dependent depolarization. The jitter photons can also scatter with those magnetic clumps inside the turbulent slab, and a nonzero variance of the Stokes parameter V can be generated. Furthermore, the linearly and circularly polarized photons in the optical and radio bands may suffer heavy absorptions from the slab. Thus we consider the polarized jitter radiation transfer processes. Finally, we compare our model results with the optical detections of GRB 091018, GRB 121024A, and GRB 131030A. We suggest simultaneous observations of GRB multi-wavelength polarization in the future.

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

International Nuclear Information System (INIS)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs

THE STRUCTURE AND LINEAR POLARIZATION OF THE KILOPARSEC-SCALE JET OF THE QUASAR 3C 345

Energy Technology Data Exchange (ETDEWEB)

Roberts, David H.; Wardle, John F. C.; Marchenko, Valerie V., E-mail: roberts@brandeis.edu [Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911 (United States)

2013-02-01

Deep Very Large Array imaging of the quasar 3C 345 at 4.86 and 8.44 GHz has been used to study the structure and linear polarization of its radio jet on scales ranging from 2 to 30 kpc. There is a 7-8 Jy unresolved core with spectral index {alpha} {approx_equal} -0.24 (I{sub {nu}}{proportional_to}{nu}{sup {alpha}}). The jet (typical intensity 15 mJy beam{sup -1}) consists of a 2.''5 straight section containing two knots, and two additional non-co-linear knots at the end. The jet's total projected length is about 27 kpc. The spectral index of the jet varies over -1.1 {approx}< {alpha} {approx}< -0.5. The jet diverges with a semi-opening angle of about 9 Degree-Sign , and is nearly constant in integrated brightness over its length. A faint feature northeast of the core does not appear to be a true counter-jet, but rather an extended lobe of this FR-II radio source seen in projection. The absence of a counter-jet is sufficient to place modest constraints on the speed of the jet on these scales, requiring {beta} {approx}> 0.5. Despite the indication of jet precession in the total intensity structure, the polarization images suggest instead a jet re-directed at least twice by collisions with the external medium. Surprisingly, the electric vector position angles in the main body of the jet are neither longitudinal nor transverse, but make an angle of about 55 Degree-Sign with the jet axis in the middle while along the edges the vectors are transverse, suggesting a helical magnetic field. There is no significant Faraday rotation in the source, so that is not the cause of the twist. The fractional polarization in the jet averages 25% and is higher at the edges. In a companion paper, Roberts and Wardle show that differential Doppler boosting in a diverging relativistic velocity field can explain the electric vector pattern in the jet.

Testing the existence of optical linear polarization in young brown dwarfs

Science.gov (United States)

Manjavacas, E.; Miles-Páez, P. A.; Zapatero-Osorio, M. R.; Goldman, B.; Buenzli, E.; Henning, T.; Pallé, E.; Fang, M.

2017-07-01

Linear polarization can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases with the degree of oblateness, which is inversely proportional to the surface gravity. We aimed to test the existence of optical linear polarization in a sample of bright young brown dwarfs, with spectral types between M6 and L2, observable from the Calar Alto Observatory, and cataloged previously as low gravity objects using spectroscopy. Linear polarimetric images were collected in I and R band using CAFOS at the 2.2-m telescope in Calar Alto Observatory (Spain). The flux ratio method was employed to determine the linear polarization degrees. With a confidence of 3σ, our data indicate that all targets have a linear polarimetry degree in average below 0.69 per cent in the I band, and below 1.0 per cent in the R band, at the time they were observed. We detected significant (I.e. P/σ ≥ 3) linear polarization for the young M6 dwarf 2MASS J04221413+1530525 in the R band, with a degree of p* = 0.81 ± 0.17 per cent.

Advances in high power linearly polarized fiber laser and its application

Science.gov (United States)

Zhou, Pu; Huang, Long; Ma, Pengfei; Xu, Jiangming; Su, Rongtao; Wang, Xiaolin

2017-10-01

Fiber lasers are now attracting more and more research interest due to their advantages in efficiency, beam quality and flexible operation. Up to now, most of the high power fiber lasers have random distributed polarization state. Linearlypolarized (LP) fiber lasers, which could find wide application potential in coherent detection, coherent/spectral beam combining, nonlinear frequency conversion, have been a research focus in recent years. In this paper, we will present a general review on the achievements of various kinds of high power linear-polarized fiber laser and its application. The recent progress in our group, including power scaling by using power amplifier with different mechanism, high power linearly polarized fiber laser with diversified properties, and various applications of high power linear-polarized fiber laser, are summarized. We have achieved 100 Watt level random distributed feedback fiber laser, kilowatt level continuous-wave (CW) all-fiber polarization-maintained fiber amplifier, 600 watt level average power picosecond polarization-maintained fiber amplifier and 300 watt level average power femtosecond polarization-maintained fiber amplifier. In addition, high power linearly polarized fiber lasers have been successfully applied in 5 kilowatt level coherent beam combining, structured light field and ultrasonic generation.

Accessing the distribution of linearly polarized gluons in unpolarized hadrons

NARCIS (Netherlands)

Boer, Daniël; Brodsky, Stanley J.; Mulders, Piet J.; Pisano, Cristian

2011-01-01

Gluons inside unpolarized hadrons can be linearly polarized provided they have a nonzero transverse momentum. The simplest and theoretically safest way to probe this distribution of linearly polarized gluons is through cos(2 phi) asymmetries in heavy quark pair or dijet production in electron-hadron

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

Energy Technology Data Exchange (ETDEWEB)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs.

Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA

Directory of Open Access Journals (Sweden)

Yong-Dae Choi

2015-06-01

Full Text Available The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.

Non-polar InGaN quantum dot emission with crystal-axis oriented linear polarization

Energy Technology Data Exchange (ETDEWEB)

Reid, Benjamin P. L., E-mail: benjamin.reid@physics.ox.ac.uk; Chan, Christopher C. S.; Taylor, Robert A. [Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Kocher, Claudius [Department of Physics, University of Konstanz, Konstanz 78457 (Germany); Zhu, Tongtong; Oehler, Fabrice; Oliver, Rachel A. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2015-04-27

Polarization sensitive photoluminescence is performed on single non-polar InGaN quantum dots. The studied InGaN quantum dots are found to have linearly polarized emission with a common polarization direction defined by the [0001] crystal axis. Around half of ∼40 studied dots have a polarization degree of 1. For those lines with a polarization degree less than 1, we can resolve fine structure splittings between −800 μeV and +800 μeV, with no clear correlation between fine structure splitting and emission energy.

Proton polarization in the photodisintegration of the deuteron by linearly polarized 400- and 500-MeV γ rays

International Nuclear Information System (INIS)

Bratashevskii, A.S.; Gorbenko, V.G.; Gushchin, V.A.

1982-01-01

The polarization of the recoil protons at the angle theta(/sub p/ = 90 0 has been measured in the photodisintegration of the deuteron by linearly polarized 400- and 500-MeV γ rays. For the first time, all of the following observables have been determined under identical experimental conditions: Σ, the asymmetry of the cross sections; P/sub y/, the polarization of the recoil proton; and T 1 , the asymmetry of the nucleon polarization for the case of linearly polarized γ rays

Linear polarization observations of some X-ray sources

International Nuclear Information System (INIS)

Shakhovskoy, N.M.; Efimov, Yu.S.

1975-01-01

Multicolour linear polarization of optical radiation of the X-ray sources Sco X-1, Cyg X-2, Cyg X-1 and Her X-1 was measured at the Crimean Astrophysical Observatory in 1970-1973. These observations indicate that polarization of Sco X-1 in the ultraviolet, blue and red spectral regions appears to be variable. No statistically significant variations of polarization were found for the other three sources observed. (Auth.)

Polarized e-e+ physics in linear colliders

International Nuclear Information System (INIS)

Prescott, C.Y.

1980-11-01

Electroweak interactions at high energies are expected to be dominated by spin-dependent forces. Recent advances in the production of polarized electron beams in linear machines provide the opportunity for studying these spin-dependent effects. Polarized e - e + annihilation at the Z 0 pole can provide precise measurements of neutral current parameters and the best experimental challenge to the standard model of electroweak interactions

Infrared Dual-Line Hanle Diagnostic of the Coronal Vector Magnetic Field

Energy Technology Data Exchange (ETDEWEB)

Dima, Gabriel I.; Kuhn, Jeffrey R. [Institute for Astronomy, University of Hawaii, Pukalani, HI (United States); Berdyugina, Svetlana V., E-mail: gdima@hawaii.edu [Institute for Astronomy, University of Hawaii, Pukalani, HI (United States); Kiepenheuer Institut fuer Sonnenphysik, Freiburg (Germany); Predictive Science Inc., San Diego, CA (United States)

2016-04-20

Measuring the coronal vector magnetic field is still a major challenge in solar physics. This is due to the intrinsic weakness of the field (e.g., ~4G at a height of 0.1R⊙ above an active region) and the large thermal broadening of coronal emission lines. We propose using concurrent linear polarization measurements of near-infrared forbidden and permitted lines together with Hanle effect models to calculate the coronal vector magnetic field. In the unsaturated Hanle regime both the direction and strength of the magnetic field affect the linear polarization, while in the saturated regime the polarization is insensitive to the strength of the field. The relatively long radiative lifetimes of coronal forbidden atomic transitions implies that the emission lines are formed in the saturated Hanle regime and the linear polarization is insensitive to the strength of the field. By combining measurements of both forbidden and permitted lines, the direction and strength of the field can be obtained. For example, the SiX 1.4301 μm line shows strong linear polarization and has been observed in emission over a large field-of-view (out to elongations of 0.5 R⊙). Here we describe an algorithm that combines linear polarization measurements of the SiX 1.4301 μm forbidden line with linear polarization observations of the HeI 1.0830 μm permitted coronal line to obtain the vector magnetic field. To illustrate the concept we assume that the emitting gas for both atomic transitions is located in the plane of the sky. The further development of this method and associated tools will be a critical step toward interpreting the high spectral, spatial and temporal infrared spectro-polarimetric measurements that will be possible when the Daniel K. Inouye Solar Telescope (DKIST) is completed in 2019.

DOA and Polarization Estimation Using an Electromagnetic Vector Sensor Uniform Circular Array Based on the ESPRIT Algorithm.

Science.gov (United States)

Wu, Na; Qu, Zhiyu; Si, Weijian; Jiao, Shuhong

2016-12-13

In array signal processing systems, the direction of arrival (DOA) and polarization of signals based on uniform linear or rectangular sensor arrays are generally obtained by rotational invariance techniques (ESPRIT). However, since the ESPRIT algorithm relies on the rotational invariant structure of the received data, it cannot be applied to electromagnetic vector sensor arrays (EVSAs) featuring uniform circular patterns. To overcome this limitation, a fourth-order cumulant-based ESPRIT algorithm is proposed in this paper, for joint estimation of DOA and polarization based on a uniform circular EVSA. The proposed algorithm utilizes the fourth-order cumulant to obtain a virtual extended array of a uniform circular EVSA, from which the pairs of rotation invariant sub-arrays are obtained. The ESPRIT algorithm and parameter pair matching are then utilized to estimate the DOA and polarization of the incident signals. The closed-form parameter estimation algorithm can effectively reduce the computational complexity of the joint estimation, which has been demonstrated by numerical simulations.

NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

International Nuclear Information System (INIS)

Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Goldman, B.; Caballero, J. A.

2011-01-01

We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 μm for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P ∼ 3%) in the J band with a significance level of P/σ P ∼ 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 ± 8 pc), this object becomes an excellent target for the direct detection of the disk.

Linear polarized fluctuations in the cosmic microwave background

International Nuclear Information System (INIS)

Partridge, R.B.; Nowakowski, J.; Martin, H.M.

1988-01-01

We report here limits on the linear (and circular) polarization of the cosmic microwave background on small angular scales, 18''≤ θ ≤ 160''. The limits are based on radio maps of Stokes parameters and polarisation (linear and circular). (author)

LINEARLY POLARIZED PROBES OF SURFACE CHIRALITY

NARCIS (Netherlands)

VERBIEST, T; KAURANEN, M; MAKI, JJ; TEERENSTRA, MN; SCHOUTEN, AJ; NOLTE, RJM; PERSOONS, A

1995-01-01

We present a new nonlinear optical technique to study surface chirality. We demonstrate experimentally that the efficiency of second-harmonic generation from isotropic chiral surfaces is different for excitation with fundamental light that is +45 degrees and -45 degrees linearly polarized with

Theoretical investigation of confocal microscopy using an elliptically polarized cylindrical vector laser beam: Visualization of quantum emitters near interfaces

Science.gov (United States)

Boichenko, Stepan

2018-04-01

We theoretically study laser-scanning confocal fluorescence microscopy using elliptically polarized cylindrical vector excitation light as a tool for visualization of arbitrarily oriented single quantum dipole emitters located (1) near planar surfaces enhancing fluorescence, (2) in a thin supported polymer film, (3) in a freestanding polymer film, and (4) in a dielectric planar microcavity. It is shown analytically that by using a tightly focused azimuthally polarized beam, it is possible to exclude completely the orientational dependence of the image intensity maximum of a quantum emitter that absorbs light as a pair of incoherent independent linear dipoles. For linear dipole quantum emitters, the orientational independence degree higher than 0.9 can normally be achieved (this quantity equal to 1 corresponds to completely excluded orientational dependence) if the collection efficiency of the microscope objective and the emitter's total quantum yield are not strongly orientationally dependent. Thus, the visualization of arbitrarily oriented single quantum emitters by means of the studied technique can be performed quite efficiently.

Reorientation effects for 52 MeV vector polarized deuterons

International Nuclear Information System (INIS)

Nurzynski, J.; Kihm, T.; Knopfle, K.T.; Mairle, G.; Clement, H.

1987-01-01

The differential cross sections and the vector analysing powers were measured for the elastic and inelastic scattering of 52 MeV vector polarized deuterons from 20 Ne, 22 Ne, 26 Mg, 28 Si, 32 S, 34 S, 36 Ar and 40 Ar nuclei. Coupled channels analysis was carried out using an axially symmetric rotational model with either prolate or oblate quadrupole deformations for each isotope. Calculations assuming harmonic vibrator model were also carried out. In general, reorientation effects were found to be weak. A global optical model potential containing an imaginary spin-orbit component was found to be the most suitable in describing the experimental data at this energy

Effect of a spiral phase on a vector optical field with hybrid polarization states

International Nuclear Information System (INIS)

Chen, Rui-Pin; Zhao, Tingyu; Zhong, Li-Xin; Chew, Khian-Hooi; Gu, Bing; Zhou, Guoquan

2015-01-01

The propagation dynamics of a vector field with inhomogeneous states of polarization (SoP) imposed a vortex is studied using the angular spectrum method. The evolution of SoP in the cross section of the field during propagation is analyzed numerically by the Stokes polarization parameters. The results indicate that SoP in the field cross section rotate along the propagation axis during propagation due to the existence of a vortex. In addition, the interaction between the phase singularity and the polarization singularity leads to the creation or annihilation of the optical field in the central region. In particular, the distributions of the transverse energy flow and both spin and orbital optical angular momentum fluxes in the cross section of the vortex vector optical field depend sensitively on both the vortex and polarization topology charges. (paper)

Linearization of germs of hyperbolic vector fields

NARCIS (Netherlands)

Bonckaert, P; Naudot, [No Value; Yang, JZ

2003-01-01

We develop a normal form to express asymptotically a conjugacy between a germ of resonant vector field and its linear part. We show that such an asymptotic expression can be written in terms of functions of the Logarithmic Mourtada type. To cite this article: P Bonckaert et al., C. R. Acad. Sci.

Magnetic field effects on ultrafast lattice compression dynamics of Si(111) crystal when excited by linearly-polarized femtosecond laser pulses

Science.gov (United States)

Hatanaka, Koji; Odaka, Hideho; Ono, Kimitoshi; Fukumura, Hiroshi

2007-03-01

Time-resolved X-ray diffraction measurements of Si (111) single crystal are performed when excited by linearly-polarized femtosecond laser pulses (780 nm, 260 fs, negatively-chirped, 1 kHz) under a magnetic field (0.47 T). Laser fluence on the sample surface is 40 mJ/cm^2, which is enough lower than the ablation threshold at 200 mJ/cm^2. Probing X-ray pulses of iron characteristic X-ray lines at 0.193604 and 0.193998 nm are generated by focusing femtosecond laser pulses onto audio-cassette tapes in air. Linearly-polarized femtosecond laser pulse irradiation onto Si(111) crystal surface induces transient lattice compression in the picosecond time range, which is confirmed by transient angle shift of X-ray diffraction to higher angles. Little difference of compression dynamics is observed when the laser polarization is changed from p to s-pol. without a magnetic field. On the other hand, under a magnetic field, the lattice compression dynamics changes when the laser is p-polarized which is vertical to the magnetic field vector. These results may be assigned to photo-carrier formation and energy-band distortion.

Production of linear polarization by segmentation of helical undulator

International Nuclear Information System (INIS)

Tanaka, T.; Kitamura, H.

2002-01-01

A simple scheme to obtain linearly polarized radiation (LPR) with a segmented undulator is proposed. The undulator is composed of several segments each of which forms a helical undulator and has helicity opposite to those of adjacent segments. Due to coherent sum of radiation, the circularly polarized component is canceled out resulting in production of LPR without any higher harmonics. The radiation from the proposed device is investigated analytically, which shows that a high degree of linear polarization is obtained in spite of a finite beam emittance and angular acceptance of optics, if a sufficiently large number of segments and an adequate photon energy are chosen. Results of calculation to investigate practical performances of the proposed device are presented

Measurement of neutron spectra for photonuclear reaction with linearly polarized photons

Directory of Open Access Journals (Sweden)

Kirihara Yoichi

2017-01-01

Full Text Available Spectra of neutrons produced by a photonuclear reaction from a 197Au target were measured using 16.95 MeV linearly and circularly polarized photon beams at NewSUBARU-BL01 using a time-of-flight method. The difference in the neutron spectra between the cases of a linearly and circularly polarized photon was measured. The difference in the neutron yield increased with the neutron energy and was approximately threefold at the maximum neutron energy. In a direction perpendicular to that of the linear polarization, the neutron yields decreased as the neutron energy increased.

Fields of an ultrashort tightly focused radially polarized laser pulse in a linear response plasma

Science.gov (United States)

Salamin, Yousef I.

2017-10-01

Analytical expressions for the fields of a radially polarized, ultrashort, and tightly focused laser pulse propagating in a linear-response plasma are derived and discussed. The fields are obtained from solving the inhomogeneous wave equations for the vector and scalar potentials, linked by the Lorenz gauge, in a plasma background. First, the scalar potential is eliminated using the gauge condition, then the vector potential is synthesized from Fourier components of an initial uniform distribution of wavenumbers, and the inverse Fourier transformation is carried out term-by-term in a truncated series (finite sum). The zeroth-order term in, for example, the axial electric field component is shown to model a pulse much better than its widely used paraxial approximation counterpart. Some of the propagation characteristics of the fields are discussed and all fields are shown to have manifested the expected limits for propagation in a vacuum.

Inducing elliptically polarized high-order harmonics from aligned molecules with linearly polarized femtosecond pulses

DEFF Research Database (Denmark)

Etches, Adam; Madsen, Christian Bruun; Madsen, Lars Bojer

2010-01-01

A recent paper reported elliptically polarized high-order harmonics from aligned N2 using a linearly polarized driving field [X. Zhou et al., Phys. Rev. Lett. 102, 073902 (2009)]. This observation cannot be explained in the standard treatment of the Lewenstein model and has been ascribed to many...

McDONALD OBSERVATORY ARCHIVE OF OPTICAL LINEAR POLARIZATION MEASUREMENTS

International Nuclear Information System (INIS)

Wills, Beverley J.; Wills, D.; Breger, M.

2011-01-01

We present 990 previously unpublished optical linear polarization measurements of quasars, active galactic nuclei, and some stars observed for interstellar polarization. The observations, covering the period 1981-2000, were made with McDonald Observatory's 2.1 m Struve reflector and the Breger photopolarimeter.

Controllability of linear vector fields on Lie groups

International Nuclear Information System (INIS)

Ayala, V.; Tirao, J.

1994-11-01

In this paper, we shall deal with a linear control system Σ defined on a Lie group G with Lie algebra g. The dynamic of Σ is determined by the drift vector field which is an element in the normalizer of g in the Lie algebra of all smooth vector field on G and by the control vectors which are elements in g considered as left-invariant vector fields. We characterize the normalizer of g identifying vector fields on G with C ∞ -functions defined on G into g. For this class of control systems we study algebraic conditions for the controllability problem. Indeed, we prove that if the drift vector field has a singularity then the Lie algebra rank condition is necessary for the controllability property, but in general this condition does not determine this property. On the other hand, we show that the rank (ad-rank) condition is sufficient for the controllability of Σ. In particular, we extend the fundamental Kalman's theorem when G is an Abelian connected Lie group. Our work is related with a paper of L. Markus and we also improve his results. (author). 7 refs

Linearly polarized emission from an embedded quantum dot using nanowire morphology control.

Science.gov (United States)

Foster, Andrew P; Bradley, John P; Gardner, Kirsty; Krysa, Andrey B; Royall, Ben; Skolnick, Maurice S; Wilson, Luke R

2015-03-11

GaAs nanowires with elongated cross sections are formed using a catalyst-free growth technique. This is achieved by patterning elongated nanoscale openings within a silicon dioxide growth mask on a (111)B GaAs substrate. It is observed that MOVPE-grown vertical nanowires with cross section elongated in the [21̅1̅] and [1̅12] directions remain faithful to the geometry of the openings. An InGaAs quantum dot with weak radial confinement is realized within each nanowire by briefly introducing indium into the reactor during nanowire growth. Photoluminescence emission from an embedded nanowire quantum dot is strongly linearly polarized (typically >90%) with the polarization direction coincident with the axis of elongation. Linearly polarized PL emission is a result of embedding the quantum dot in an anisotropic nanowire structure that supports a single strongly confined, linearly polarized optical mode. This research provides a route to the bottom-up growth of linearly polarized single photon sources of interest for quantum information applications.

Full-Stokes polarimetry with circularly polarized feeds. Sources with stable linear and circular polarization in the GHz regime

Science.gov (United States)

Myserlis, I.; Angelakis, E.; Kraus, A.; Liontas, C. A.; Marchili, N.; Aller, M. F.; Aller, H. D.; Karamanavis, V.; Fuhrmann, L.; Krichbaum, T. P.; Zensus, J. A.

2018-01-01

We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Müller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1°. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85 GHz and 8.35 GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1° at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree mc, four of them with non-zero mc. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Müller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well. The data used to create Fig. C.1 are only available at the CDS via anonymous ftp to http

Investigating circular patterns in linear polarization observations of Venus

NARCIS (Netherlands)

Mahapatra, G.; Stam, D.M.; Rossi, L.C.G.; Rodenhuis, M.; Snik, Frans; Keller, C.U.

2017-01-01

In this work, we analyse linear polarization data of the planet at a distance, obtained with the Extreme Polarimeter (ExPo) on the William Herschel Telescope
on La Palma. These spatially resolved, high-accuracy polarization observations of Venus show faint circular patterns centered on the

General solution of linear vector supersymmetry

International Nuclear Information System (INIS)

Blasi, Alberto; Maggiore, Nicola

2007-01-01

We give the general solution of the Ward identity for the linear vector supersymmetry which characterizes all topological models. Such a solution, whose expression is quite compact and simple, greatly simplifies the study of theories displaying a supersymmetric algebraic structure, reducing to a few lines the proof of their possible finiteness. In particular, the cohomology technology, usually involved for the quantum extension of these theories, is completely bypassed. The case of Chern-Simons theory is taken as an example

LINEAR POLARIZATION OF CLASS I METHANOL MASERS IN MASSIVE STAR-FORMING REGIONS

International Nuclear Information System (INIS)

Kang, Ji-hyun; Byun, Do-Young; Kim, Kee-Tae; Kim, Jongsoo; Lyo, A-Ran; Vlemmings, W. H. T.

2016-01-01

Class I methanol masers are found to be good tracers of the interaction between outflows from massive young stellar objects with their surrounding media. Although polarization observations of Class II methanol masers have been able to provide information about magnetic fields close to the central (proto)stars, polarization observations of Class I methanol masers are rare, especially at 44 and 95 GHz. We present the results of linear polarization observations of 39 Class I methanol maser sources at 44 and 95 GHz. These two lines are observed simultaneously with one of the 21 m Korean VLBI Network telescopes in single-dish mode. Approximately 60% of the observed sources have fractional polarizations of a few percent in at least one transition. This is the first reported detection of linear polarization of the 44 GHz methanol maser. The two maser transitions show similar polarization properties, indicating that they trace similar magnetic environments, although the fraction of the linear polarization is slightly higher at 95 GHz. We discuss the association between the directions of polarization angles and outflows. We also discuss some targets having different polarization properties at both lines, including DR21(OH) and G82.58+0.20, which show the 90° polarization angle flip at 44 GHz.

A linear polarization converter with near unity efficiency in microwave regime

Science.gov (United States)

Xu, Peng; Wang, Shen-Yun; Geyi, Wen

2017-04-01

In this paper, we present a linear polarization converter in the reflective mode with near unity conversion efficiency. The converter is designed in an array form on the basis of a pair of orthogonally arranged three-dimensional split-loop resonators sharing a common terminal coaxial port and a continuous metallic ground slab. It converts the linearly polarized incident electromagnetic wave at resonance to its orthogonal counterpart upon the reflection mode. The conversion mechanism is explained by an equivalent circuit model, and the conversion efficiency can be tuned by changing the impedance of the terminal port. Such a scheme of the linear polarization converter has potential applications in microwave communications, remote sensing, and imaging.

SDP_mharwit_1: Demonstration of HIFI Linear Polarization Analysis of Spectral Features

Science.gov (United States)

Harwit, M.

2010-03-01

We propose to observe the polarization of the 621 GHz water vapor maser in VY Canis Majoris to demonstrate the capability of HIFI to make polarization observations of Far-Infrared/Submillimeter spectral lines. The proposed Demonstration Phase would: - Show that HIFI is capable of interesting linear polarization measurements of spectral lines; - Test out the highest spectral resolving power to sort out closely spaced Doppler components; - Determine whether the relative intensities predicted by Neufeld and Melnick are correct; - Record the degree and direction of linear polarization for the closely-Doppler shifted peaks.

Development of polarized e+ beams for future linear colliders

International Nuclear Information System (INIS)

Chiba, M.; Hamatsu, R.; Endo, A.

1995-01-01

We have so far been carrying out systematic investigations to create polarized e + on the basis of two new methods. One method is to use β + decay of radioactive nuclei with short life-time produced with a proton cyclotron and the other method is to use e + e - pair creation from polarized γ beams made through backward Compton scattering of laser lights. Here we describe technical details on productions of polarized e + and measurements of the polarization. The experiments of producing polarized e + will soon start. Although the e + intensity is not sufficiently high, we will acquire lots of know-how for further development of polarized e + sources with high quality which will possibly be applied to future linear colliders. (author)

Dual-band linearly and circularly polarized microstrip patch antennas with meandering slot and metallic vias

DEFF Research Database (Denmark)

Zhang, Jin; Lin, Xianqi; Yu, Jiawei

2018-01-01

performances. The characteristics are analyzed in detail where we find that the existence of the vias also improves the impedance matching. Four samples are designed, where dual-band with both linear polarization, dual-band with circular- and linear-polarization, and single band with linear polarization...

Structured caustic vector vortex optical field: manipulating optical angular momentum flux and polarization rotation.

Science.gov (United States)

Chen, Rui-Pin; Chen, Zhaozhong; Chew, Khian-Hooi; Li, Pei-Gang; Yu, Zhongliang; Ding, Jianping; He, Sailing

2015-05-29

A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.

Linearized interactions of scalar and vector fields with the higher spin field in AdSD

International Nuclear Information System (INIS)

Mkrtchyan, K.

2011-01-01

The explicit form of linearized gauge and generalized 'Weyl invariant' interactions of scalar and general higher even spin fields in the AdS D space is reviewed. Also a linearized interaction of vector field with general higher even spin gauge field is obtained. It is shown that the gauge-invariant action of linearized vector field interacting with the higher spin field also includes the whole tower of invariant actions for couplings of the same vector field with the gauge fields of smaller even spin

Linear Transformation of the Polarization Modes in Coiled Optical Spun-Fibers with Strong Unperturbed Linear Birefringence. I. Nonresonant Transformation

Science.gov (United States)

Malykin, G. B.; Pozdnyakova, V. I.

2018-03-01

A linear transformation of orthogonal polarization modes in coiled optical spun-fibers with strong unperturbed linear birefringence, which causes the emergence of the dependences of the integrated elliptical birefringence and the ellipticity and azimuth of the major axis of the ellipse, as well as the polarization state of radiation (PSR), on the length of optical fiber has been considered. Optical spun-fibers are subjected to a strong mechanical twisting, which is frozen into the structure of the optical fiber upon cooling, in the process of being drawn out from the workpiece. Since the values of the local polarization parameters of coiled spunwaveguides vary according to a rather complex law, the calculations were carried out by numerical modeling of the parameters of the Jones matrices. Since the rotation speed of the axes of the birefringence is constant on a relatively short segment of a coiled optical spun-fiber in the accompanying torsion (helical) coordinate system, the so-called "Ginzburg helical polarization modes" (GHPMs)—two mutually orthogonal ellipses with the opposite directions of traversal, the axis of which rotate relative to the fixed coordinate system uniformly and unidirectionally—are approximately the local normal polarization modes of such optical fiber. It has been shown that, despite the fact that the unperturbed linear birefringence of the spun-fibers significantly exceeds the linear birefringence, which is caused by the winding on a coil, the integral birefringence of an extended segment of such a fiber coincides in order of magnitude with the linear birefringence, which is caused by the winding on the coil, and the integral polarization modes tend asymptotically to circular ones. It has been also shown that the values of the circular birefringence of twisted single-mode fibers, which were calculated in a nonrotating and torsion helical coordinate systems, differ significantly. It has been shown that the polarization phenomena occur

Polarization ellipse and Stokes parameters in geometric algebra.

Science.gov (United States)

Santos, Adler G; Sugon, Quirino M; McNamara, Daniel J

2012-01-01

In this paper, we use geometric algebra to describe the polarization ellipse and Stokes parameters. We show that a solution to Maxwell's equation is a product of a complex basis vector in Jackson and a linear combination of plane wave functions. We convert both the amplitudes and the wave function arguments from complex scalars to complex vectors. This conversion allows us to separate the electric field vector and the imaginary magnetic field vector, because exponentials of imaginary scalars convert vectors to imaginary vectors and vice versa, while exponentials of imaginary vectors only rotate the vector or imaginary vector they are multiplied to. We convert this expression for polarized light into two other representations: the Cartesian representation and the rotated ellipse representation. We compute the conversion relations among the representation parameters and their corresponding Stokes parameters. And finally, we propose a set of geometric relations between the electric and magnetic fields that satisfy an equation similar to the Poincaré sphere equation.

Linearly Polarized IR Spectroscopy Theory and Applications for Structural Analysis

CERN Document Server

Kolev, Tsonko

2011-01-01

A technique that is useful in the study of pharmaceutical products and biological molecules, polarization IR spectroscopy has undergone continuous development since it first emerged almost 100 years ago. Capturing the state of the science as it exists today, "Linearly Polarized IR Spectroscopy: Theory and Applications for Structural Analysis" demonstrates how the technique can be properly utilized to obtain important information about the structure and spectral properties of oriented compounds. The book starts with the theoretical basis of linear-dichroic infrared (IR-LD) spectroscop

LINEAR KERNEL SUPPORT VECTOR MACHINES FOR MODELING PORE-WATER PRESSURE RESPONSES

Directory of Open Access Journals (Sweden)

KHAMARUZAMAN W. YUSOF

2017-08-01

Full Text Available Pore-water pressure responses are vital in many aspects of slope management, design and monitoring. Its measurement however, is difficult, expensive and time consuming. Studies on its predictions are lacking. Support vector machines with linear kernel was used here to predict the responses of pore-water pressure to rainfall. Pore-water pressure response data was collected from slope instrumentation program. Support vector machine meta-parameter calibration and model development was carried out using grid search and k-fold cross validation. The mean square error for the model on scaled test data is 0.0015 and the coefficient of determination is 0.9321. Although pore-water pressure response to rainfall is a complex nonlinear process, the use of linear kernel support vector machine can be employed where high accuracy can be sacrificed for computational ease and time.

On the inclusive reaction e+e- → VX with regard for polarization states of generated vector meson

International Nuclear Information System (INIS)

Khachtryan, G.N.; Shakhnazaryan, Yu.G.

1977-01-01

The e + e - →VX inclusive process has been considered with allowance made for polarization states of a vector meson. The tensor that describes the vortex of the γ→VX transition has also been considered. In the general case the tensor contains eight structural functions. The elements of the vector meson density matrix have been calculated in the spiral representation. These elements are expressed in terms of the given structural functions and polarization vectors of annihilating particles. It is shown that the structural functions can be determined from the study of angular distribution of products of the meson vector decay on pseudoscalar particles (p→2π, ω→3π, phi→2K) and on a lepton-antilepton pair (PSI, PSI'→e + e - )

Quasi-Linear Polarized Modes in Y-Rotated Piezoelectric GaPO4 Plates

Directory of Open Access Journals (Sweden)

Cinzia Caliendo

2014-07-01

Full Text Available The propagation of both surface and flexural acoustic plate modes along y-rotated x-propagation GaPO4 piezoelectric substrates was studied for several y-cut angles: the phase velocity and coupling coefficient dispersion curves were theoretically calculated for two different electroacoustic coupling configurations. The investigation of the acoustic field profile across the plate thickness revealed the presence of thin plate modes having polarization predominantly oriented along the propagation direction, and hence suitable for operation in liquid environment. These modes include the linearly polarized Anisimkin Jr. and the quasi longitudinal plate modes, AMs and QLs, showing a phase velocity close to that of the longitudinal bulk acoustic wave propagating in the same direction. The temperature coefficient of delay (TCD of these longitudinal modes was investigated in the −20 to 420 °C temperature range, in order to identify thermally stable or low TCD cuts. The power flow angle, i.e., the angle between the phase and group velocity vectors, was also estimated to evaluate the substrate anisotropy effect on the acoustic wave propagation. The GaPO4 intrinsic properties, such as its resistance to high temperature and its chemical inertness, make it especially attractive for the development of acoustic waves-based sensors for applications in harsh liquid environment.

Knot Undulator to Generate Linearly Polarized Photons with Low on-Axis Power Density

International Nuclear Information System (INIS)

Qiao, S.

2009-01-01

Heat load on beamline optics is a serious problem to generate pure linearly polarized photons in the third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by a figure-8 operating mode. But there is still no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel operating mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Also the available minimum photon energy of linearly polarized photons can be extended much by this method.

On the Possibility of Resonances in Longitudinally Polarized Vector Boson Scattering

NARCIS (Netherlands)

Veltman, M.J.G.; Veltman, H.

1991-01-01

Assuming that no Higgs has been found below 1 TeV, we study the physics of longitudinally polarized vector boson ( ) scattering in the TeV region, using a one loop calculation and partial wave analysis. We show that the occurrence of a resonance in the isospin I = 1 channel depends on a certain

Stokes vector based interpolation method to improve the efficiency of bio-inspired polarization-difference imaging in turbid media

Science.gov (United States)

Guan, Jinge; Ren, Wei; Cheng, Yaoyu

2018-04-01

We demonstrate an efficient polarization-difference imaging system in turbid conditions by using the Stokes vector of light. The interaction of scattered light with the polarizer is analyzed by the Stokes-Mueller formalism. An interpolation method is proposed to replace the mechanical rotation of the polarization axis of the analyzer theoretically, and its performance is verified by the experiment at different turbidity levels. We show that compared with direct imaging, the Stokes vector based imaging method can effectively reduce the effect of light scattering and enhance the image contrast.

Development of a NEW Vector Magnetograph at Marshall Space Flight Center

Science.gov (United States)

West, Edward; Hagyard, Mona; Gary, Allen; Smith, James; Adams, Mitzi; Rose, M. Franklin (Technical Monitor)

2001-01-01

This paper will describe the Experimental Vector Magnetograph that has been developed at the Marshall Space Flight Center (MSFC). This instrument was designed to improve linear polarization measurements by replacing electro-optic and rotating waveplate modulators with a rotating linear analyzer. Our paper will describe the motivation for developing this magnetograph, compare this instrument with traditional magnetograph designs, and present a comparison of the data acquired by this instrument and original MSFC vector magnetograph.

Polarization and ellipticity of high-order harmonics from aligned molecules generated by linearly polarized intense laser pulses

International Nuclear Information System (INIS)

Le, Anh-Thu; Lin, C. D.; Lucchese, R. R.

2010-01-01

We present theoretical calculations for polarization and ellipticity of high-order harmonics from aligned N 2 , CO 2 , and O 2 molecules generated by linearly polarized lasers. Within the rescattering model, the two polarization amplitudes of the harmonics are determined by the photo-recombination amplitudes for photons emitted with polarization parallel or perpendicular to the direction of the same returning electron wave packet. Our results show clear species-dependent polarization states, in excellent agreement with experiments. We further note that the measured polarization ellipse of the harmonic furnishes the needed parameters for a 'complete' experiment in molecules.

Fermi wave vector for the partially spin-polarized composite-fermion Fermi sea

Science.gov (United States)

Balram, Ajit C.; Jain, J. K.

2017-12-01

The fully spin-polarized composite-fermion (CF) Fermi sea at the half-filled lowest Landau level has a Fermi wave vector kF*=√{4 π ρe } , where ρe is the density of electrons or composite fermions, supporting the notion that the interaction between composite fermions can be treated perturbatively. Away from ν =1 /2 , the area is seen to be consistent with kF*=√{4 π ρe } for ν 1 /2 , where ρh is the density of holes in the lowest Landau level. This result is consistent with particle-hole symmetry in the lowest Landau level. We investigate in this article the Fermi wave vector of the spin-singlet CF Fermi sea (CFFS) at ν =1 /2 , for which particle-hole symmetry is not a consideration. Using the microscopic CF theory, we find that for the spin-singlet CFFS the Fermi wave vectors for up- and down-spin CFFSs at ν =1 /2 are consistent with kF*↑,↓=√{4 π ρe↑,↓ } , where ρe↑=ρe↓=ρe/2 , which implies that the residual interactions between composite fermions do not cause a nonperturbative correction for spin-singlet CFFS either. Our results suggest the natural conjecture that for arbitrary spin polarization the CF Fermi wave vectors are given by kF*↑=√{4 π ρe↑ } and kF*↓=√{4 π ρe↓ } .

Vectorization of linear discrete filtering algorithms

Science.gov (United States)

Schiess, J. R.

1977-01-01

Linear filters, including the conventional Kalman filter and versions of square root filters devised by Potter and Carlson, are studied for potential application on streaming computers. The square root filters are known to maintain a positive definite covariance matrix in cases in which the Kalman filter diverges due to ill-conditioning of the matrix. Vectorization of the filters is discussed, and comparisons are made of the number of operations and storage locations required by each filter. The Carlson filter is shown to be the most efficient of the filters on the Control Data STAR-100 computer.

Rotation of the cosmic microwave background polarization from weak gravitational lensing.

Science.gov (United States)

Dai, Liang

2014-01-31

When a cosmic microwave background (CMB) photon travels from the surface of last scatter through spacetime metric perturbations, the polarization vector may rotate about its direction of propagation. This gravitational rotation is distinct from, and occurs in addition to, the lensing deflection of the photon trajectory. This rotation can be sourced by linear vector or tensor metric perturbations and is fully coherent with the curl deflection field. Therefore, lensing corrections to the CMB polarization power spectra as well as the temperature-polarization cross correlations due to nonscalar perturbations are modified. The rotation does not affect lensing by linear scalar perturbations, but needs to be included when calculations go to higher orders. We present complete results for weak lensing of the full-sky CMB power spectra by general linear metric perturbations, taking into account both deflection of the photon trajectory and rotation of the polarization. For the case of lensing by gravitational waves, we show that the B modes induced by the rotation largely cancel those induced by the curl component of deflection.

The spin polarized linear response from density functional theory: Theory and application to atoms

Energy Technology Data Exchange (ETDEWEB)

Fias, Stijn, E-mail: sfias@vub.ac.be; Boisdenghien, Zino; De Proft, Frank; Geerlings, Paul [General Chemistry (ALGC), Vrije Universiteit Brussel (Free University Brussels – VUB), Pleinlaan 2, 1050 Brussels (Belgium)

2014-11-14

Within the context of spin polarized conceptual density functional theory, the spin polarized linear response functions are introduced both in the [N, N{sub s}] and [N{sub α}, N{sub β}] representations. The mathematical relations between the spin polarized linear response functions in both representations are examined and an analytical expression for the spin polarized linear response functions in the [N{sub α}, N{sub β}] representation is derived. The spin polarized linear response functions were calculated for all atoms up to and including argon. To simplify the plotting of our results, we integrated χ(r, r′) to a quantity χ(r, r{sup ′}), circumventing the θ and ϕ dependence. This allows us to plot and to investigate the periodicity throughout the first three rows in the periodic table within the two different representations. For the first time, χ{sub αβ}(r, r{sup ′}), χ{sub βα}(r, r{sup ′}), and χ{sub SS}(r, r{sup ′}) plots have been calculated and discussed. By integration of the spin polarized linear response functions, different components to the polarisability, α{sub αα}, α{sub αβ}, α{sub βα}, and α{sub ββ} have been calculated.

Photonic engineering of highly linearly polarized quantum dot emission at telecommunication wavelengths

Science.gov (United States)

Mrowiński, P.; Emmerling, M.; Schneider, C.; Reithmaier, J. P.; Misiewicz, J.; Höfling, S.; Sek, G.

2018-04-01

In this work, we discuss a method to control the polarization anisotropy of spontaneous emission from neutral excitons confined in quantum-dot-like nanostructures, namely single epitaxial InAs quantum dashes emitting at telecom wavelengths. The nanostructures are embedded inside lithographically defined, in-plane asymmetric photonic mesa structures, which generate polarization-dependent photonic confinement. First, we study the influence of the photonic confinement on the polarization anisotropy of the emission by photoluminescence spectroscopy, and we find evidence of different contributions to a degree of linear polarization (DOLP), i.e., from the quantum dash and the photonic mesa, in total giving rise to DOLP =0.85 . Then, we perform finite-difference time-domain simulations of photonic confinement, and we calculate the DOLP in a dipole approximation showing well-matched results for the established model. Furthermore, by using numerical calculations, we demonstrate several types of photonic confinements where highly linearly polarized emission with DOLP of about 0.9 is possible by controlling the position of a quantum emitter inside the photonic structure. Then, we elaborate on anisotropic quantum emitters allowing for exceeding DOLP =0.95 in an optimized case, and we discuss the ways towards efficient linearly polarized single photon source at telecom bands.

Realizing Broadband and Invertible Linear-to-circular Polarization Converter with Ultrathin Single-layer Metasurface

Science.gov (United States)

Li, Zhancheng; Liu, Wenwei; Cheng, Hua; Chen, Shuqi; Tian, Jianguo

2015-01-01

The arbitrary control of the polarization states of light has attracted the interest of the scientific community because of the wide range of modern optical applications that such control can afford. However, conventional polarization control setups are bulky and very often operate only within a narrow wavelength range, thereby resisting optical system miniaturization and integration. Here, we present the basic theory, simulated demonstration, and in-depth analysis of a high-performance broadband and invertible linear-to-circular (LTC) polarization converter composed of a single-layer gold nanorod array with a total thickness of ~λ/70 for the near-infrared regime. This setup can transform a circularly polarized wave into a linearly polarized one or a linearly polarized wave with a wavelength-dependent electric field polarization angle into a circularly polarized one in the transmission mode. The broadband and invertible LTC polarization conversion can be attributed to the tailoring of the light interference at the subwavelength scale via the induction of the anisotropic optical resonance mode. This ultrathin single-layer metasurface relaxes the high-precision requirements of the structure parameters in general metasurfaces while retaining the polarization conversion performance. Our findings open up intriguing possibilities towards the realization of novel integrated metasurface-based photonics devices for polarization manipulation, modulation, and phase retardation. PMID:26667360

Generation of vector beams using a double-wedge depolarizer: Non-quantum entanglement

Science.gov (United States)

Samlan, C. T.; Viswanathan, Nirmal K.

2016-07-01

Propagation of horizontally polarized Gaussian beam through a double-wedge depolarizer generates vector beams with spatially varying state of polarization. Jones calculus is used to show that such beams are maximally nonseparable on the basis of even (Gaussian)-odd (Hermite-Gaussian) mode parity and horizontal-vertical polarization state. The maximum nonseparability in the two degrees of freedom of the vector beam at the double wedge depolarizer output is verified experimentally using a modified Sagnac interferometer and linear analyser projected interferograms to measure the concurrence 0.94±0.002 and violation of Clauser-Horne-Shimony-Holt form of Bell-like inequality 2.704±0.024. The investigation is carried out in the context of the use of vector beams for metrological applications.

Observer-dependent sign inversions of polarization singularities.

Science.gov (United States)

Freund, Isaac

2014-10-15

We describe observer-dependent sign inversions of the topological charges of vector field polarization singularities: C points (points of circular polarization), L points (points of linear polarization), and two virtually unknown singularities we call γ(C) and α(L) points. In all cases, the sign of the charge seen by an observer can change as she changes the direction from which she views the singularity. Analytic formulas are given for all C and all L point sign inversions.

Quantitative investigation of linear arbitrary polarization in an APPLE-II undulator.

Science.gov (United States)

Hand, Matthew; Wang, Hongchang; Maccherozzi, Francesco; Apollonio, Marco; Zhu, Jingtao; Dhesi, Sarnjeet S; Sawhney, Kawal

2018-03-01

Insertion devices are utilized at synchrotron radiation facilities around the world for their capability to provide a high-brilliance X-ray beam. APPLE-II type undulators are especially important for their capacity to switch between a variety of photon beam polarization states. A high-precision soft X-ray polarimeter has been used to investigate the polarization calibration of an APPLE-II undulator (period length λ u = 64 mm) installed on beamline I06 at Diamond Light Source. Systematic measurement of the beam polarization state at a range of linear arbitrary angles has been compared with the expected result for a given set of undulator gap and row phase parameters calculated from theory. Determination of the corresponding Stokes-Poincaré parameters from the measured data reveals a discrepancy between the two. The limited number of energy/polarization combinations included in the undulator calibration tables necessitates the use of interpolated values for the missing points which is expected to contribute to the discrepancy. However, by modifying the orbit of the electron beam through the undulator by at least 160 µm it has been found that for certain linear polarizations the discrepancies can be corrected. Overall, it is suggested that complete correction of the Stokes-Poincaré parameters for all linear angles would require alteration of both these aspects.

Production of polarized vector mesons off nuclei

International Nuclear Information System (INIS)

Kopeliovich, B. Z.; Nemchik, J.; Schmidt, Ivan

2007-01-01

Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q 2 dependence of the L/T ratios for ρ 0 mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T ratio at different values of Q 2 . In contrast, for a coherent process the contraction of the CL with Q 2 causes an effect opposite to that of CT and we expect quite a nontrivial A dependence

In-line phase retarder and polarimeter for conversion of linear to circular polarization

Energy Technology Data Exchange (ETDEWEB)

Kortright, J.B.; Smith, N.V.; Denlinger, J.D. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

An in-line polarimeter including phase retarder and linear polarizer was designed and commissioned on undulator beamline 7.0 for the purpose of converting linear to circular polarization for experiments downstream. In commissioning studies, Mo/Si multilayers at 95 eV were used both as the upstream, freestanding phase retarder and the downstream linear polarized. The polarization properties of the phase retarder were characterized by direct polarimetry and by collecting MCD spectra in photoemission from Gd and other magnetic surfaces. The resonant birefringence of transmission multilayers results from differing distributions of s- and p-component wave fields in the multilayer when operating near a structural (Bragg) interference condition. The resulting phase retardation is especially strong when the interference is at or near the Brewster angle, which is roughly 45{degrees} in the EUV and soft x-ray ranges.

MgII Linear Polarization Measurements Using the MSFC Solar Ultraviolet Magnetograph

Science.gov (United States)

West, Edward; Cirtain, Jonathan; Kobayahsi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

2011-01-01

This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph (SUMI) sounding rocket program, with emphasis on the polarization characteristics of the VUV optics and their spectral, spatial and polarization resolution. SUMI's first flight (7/30/2010) met all of its mission success criteria and this paper will describe the data that was acquired with emphasis on the MgII linear polarization measurements.

Optical force exerted on a Rayleigh particle by a vector arbitrary-order Bessel beam

International Nuclear Information System (INIS)

Yang, Ruiping; Li, Renxian

2016-01-01

An analytical description of optical force on a Rayleigh particle by a vector Bessel beam is investigated. Linearly, radially, azimuthally, and circularly polarized Bessel beams are considered. The radial, azimuthal, and axial forces by a vector Bessel beam are numerically simulated. The effect of polarization, order of beams, and half-cone angle to the optical force are mainly discussed. For Bessel beams of larger half-cone angle, the non-paraxiality of beams plays an important role in optical forces. Numerical calculations show that optical forces, especially azimuthal forces, are very sensitive to the polarization of beams. - Highlights: • Optical force exerted on a Rayleigh particle by a vector Bessel beam is analytically derived. • Radial, azimuthal, and axial forces are numerically analyzed. • The effect of polarization, order of beam, and non-paraxiality is analyzed.

VECTOR TOMOGRAPHY FOR THE CORONAL MAGNETIC FIELD. II. HANLE EFFECT MEASUREMENTS

International Nuclear Information System (INIS)

Kramar, M.; Inhester, B.; Lin, H.; Davila, J.

2013-01-01

In this paper, we investigate the feasibility of saturated coronal Hanle effect vector tomography or the application of vector tomographic inversion techniques to reconstruct the three-dimensional magnetic field configuration of the solar corona using linear polarization measurements of coronal emission lines. We applied Hanle effect vector tomographic inversion to artificial data produced from analytical coronal magnetic field models with equatorial and meridional currents and global coronal magnetic field models constructed by extrapolation of real photospheric magnetic field measurements. We tested tomographic inversion with only Stokes Q, U, electron density, and temperature inputs to simulate observations over large limb distances where the Stokes I parameters are difficult to obtain with ground-based coronagraphs. We synthesized the coronal linear polarization maps by inputting realistic noise appropriate for ground-based observations over a period of two weeks into the inversion algorithm. We found that our Hanle effect vector tomographic inversion can partially recover the coronal field with a poloidal field configuration, but that it is insensitive to a corona with a toroidal field. This result demonstrates that Hanle effect vector tomography is an effective tool for studying the solar corona and that it is complementary to Zeeman effect vector tomography for the reconstruction of the coronal magnetic field

Achievement of needle-like focus by engineering radial-variant vector fields.

Science.gov (United States)

Gu, Bing; Wu, Jia-Lu; Pan, Yang; Cui, Yiping

2013-12-16

We present and demonstrate a novel method for engineering the radial-variant polarization on the incident field to achieve a needle of transversally polarized field without any pupil filters. We generate a new kind of localized linearly-polarized vector fields with distributions of states of polarization (SoPs) describing by the radius to the power p and explore its tight focusing, nonparaxial focusing, and paraxial focusing properties. By tuning the power p, we obtain the needle-like focal field with hybrid SoPs and give the formula for describing the length of the needle. Experimentally, we systematically investigate both the intensity distributions and the polarization evolution of the optical needle by paraxial focusing the generated vector field. Such an optical needle, which enhances the light-matter interaction, has intriguing applications in optical microma-chining and nonlinear optics.

Strong WW scattering at photon linear colliders

International Nuclear Information System (INIS)

Berger, M.S.

1994-06-01

We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process γγ → ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f 2 (1270) meson

On the derivation of vector radiative transfer equation for polarized radiative transport in graded index media

International Nuclear Information System (INIS)

Zhao, J.M.; Tan, J.Y.; Liu, L.H.

2012-01-01

Light transport in graded index media follows a curved trajectory determined by Fermat's principle. Besides the effect of variation of the refractive index on the transport of radiative intensity, the curved ray trajectory will induce geometrical effects on the transport of polarization ellipse. This paper presents a complete derivation of vector radiative transfer equation for polarized radiation transport in absorption, emission and scattering graded index media. The derivation is based on the analysis of the conserved quantities for polarized light transport along curved trajectory and a novel approach. The obtained transfer equation can be considered as a generalization of the classic vector radiative transfer equation that is only valid for uniform refractive index media. Several variant forms of the transport equation are also presented, which include the form for Stokes parameters defined with a fixed reference and the Eulerian forms in the ray coordinate and in several common orthogonal coordinate systems.

Design of a dual linear polarization antenna using split ring resonators at X-band

Science.gov (United States)

Ahmed, Sadiq; Chandra, Madhukar

2017-11-01

Dual linear polarization microstrip antenna configurations are very suitable for high-performance satellites, wireless communication and radar applications. This paper presents a new method to improve the co-cross polarization discrimination (XPD) for dual linear polarized microstrip antennas at 10 GHz. For this, three various configurations of a dual linear polarization antenna utilizing metamaterial unit cells are shown. In the first layout, the microstrip patch antenna is loaded with two pairs of spiral ring resonators, in the second model, a split ring resonator is placed between two microstrip feed lines, and in the third design, a complementary split ring resonators are etched in the ground plane. This work has two primary goals: the first is related to the addition of metamaterial unit cells to the antenna structure which permits compensation for an asymmetric current distribution flow on the microstrip antenna and thus yields a symmetrical current distribution on it. This compensation leads to an important enhancement in the XPD in comparison to a conventional dual linear polarized microstrip patch antenna. The simulation reveals an improvement of 7.9, 8.8, and 4 dB in the E and H planes for the three designs, respectively, in the XPD as compared to the conventional dual linear polarized patch antenna. The second objective of this paper is to present the characteristics and performances of the designs of the spiral ring resonator (S-RR), split ring resonator (SRR), and complementary split ring resonator (CSRR) metamaterial unit cells. The simulations are evaluated using the commercial full-wave simulator, Ansoft High-Frequency Structure Simulator (HFSS).

Linearly polarized photoluminescence of InGaN quantum disks embedded in GaN nanorods.

Science.gov (United States)

Park, Youngsin; Chan, Christopher C S; Nuttall, Luke; Puchtler, Tim J; Taylor, Robert A; Kim, Nammee; Jo, Yongcheol; Im, Hyunsik

2018-05-25

We have investigated the emission from InGaN/GaN quantum disks grown on the tip of GaN nanorods. The emission at 3.21 eV from the InGaN quantum disk doesn't show a Stark shift, and it is linearly polarized when excited perpendicular to the growth direction. The degree of linear polarization is about 39.3% due to the anisotropy of the nanostructures. In order to characterize a single nanostructure, the quantum disks were dispersed on a SiO 2 substrate patterned with a metal reference grid. By rotating the excitation polarization angle from parallel to perpendicular relative to the nanorods, the variation of overall PL for the 3.21 eV peak was recorded and it clearly showed the degree of linear polarization (DLP) of 51.5%.

Sky light polarization detection with linear polarizer triplet in light field camera inspired by insect vision.

Science.gov (United States)

Zhang, Wenjing; Cao, Yu; Zhang, Xuanzhe; Liu, Zejin

2015-10-20

Stable information of a sky light polarization pattern can be used for navigation with various advantages such as better performance of anti-interference, no "error cumulative effect," and so on. But the existing method of sky light polarization measurement is weak in real-time performance or with a complex system. Inspired by the navigational capability of a Cataglyphis with its compound eyes, we introduce a new approach to acquire the all-sky image under different polarization directions with one camera and without a rotating polarizer, so as to detect the polarization pattern across the full sky in a single snapshot. Our system is based on a handheld light field camera with a wide-angle lens and a triplet linear polarizer placed over its aperture stop. Experimental results agree with the theoretical predictions. Not only real-time detection but simple and costless architecture demonstrates the superiority of the approach proposed in this paper.

Linearly Polarized Gluons and the Higgs Transverse Momentum Distribution

NARCIS (Netherlands)

Boer, Daniel; den Dunnen, Wilco J.; Pisano, Cristian; Schlegel, Marc; Vogelsang, Werner

2012-01-01

We study how gluons carrying linear polarization inside an unpolarized hadron contribute to the transverse momentum distribution of Higgs bosons produced in hadronic collisions. They modify the distribution produced by unpolarized gluons in a characteristic way that could be used to determine

Spin and parity assignments to dipole excitations of the odd-mass nucleus {sup 207}Pb from nuclear resonance fluorescence experiments with linearly-polarized {gamma}-ray beams

Energy Technology Data Exchange (ETDEWEB)

Pietralla, N; Fritzsche, M; Savran, D [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Li, T C [Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Ahmed, M W; Tonchev, A P; Tornow, W; Weller, H R [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Werner, V, E-mail: pietralla@ikp.tu-darmstadt.d [A.W. Wright Nuclear Structure Laboratory (WNSL), Yale University, New Haven, CT (United States)

2010-01-01

Pb({gamma}-vector ,{gamma}') photon scattering reactions were studied [1] with the nearly monochromatic, linearly polarized photon beams at the High Intensity {gamma}-ray Source (HI{gamma}S) at the DFELL. Azimuthal scattering intensity asymmetries measured with respect to the polarization plane of the beam have been used for the first time to assign both the spin and parity quantum numbers of dipole excited states of {sup 206,207,208}Pb at excitation energies in the vicinity of 5.5 MeV. Evidence for dominant particle-core coupling is deduced from these results along with information on excitation energies and electromagnetic transition matrix elements.

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

International Nuclear Information System (INIS)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-01-01

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, λ=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

Energy Technology Data Exchange (ETDEWEB)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-07-15

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, {lambda}=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc.

General formulae for polarization observables in deuteron electrodisintegration and linear relations

International Nuclear Information System (INIS)

Arenhoevel, H.; Leidemann, W.; Tomusiak, E.L.

1993-01-01

Formal expressions are derived for all possible polarization observables in deuteron electrodisintegration with longitudinally polarized incoming electrons, oriented deuteron targets and polarization analysis of outgoing nucleons. They are given in terms of general structure functions which can be determined experimentally. These structure functions are Hermitean forms of the T-matrix elements which, in principle, allow the determination of all T-matrix elements up to an arbitrary common phase. Since the set of structure functions is overcomplete, linear relations among various structure functions exist which are derived explicitly

Radiation self-polarization of electrons moving in a magnetic field. [Vector spin operator, relaxation time

Energy Technology Data Exchange (ETDEWEB)

Bagrov, V G; Dorofeev, O F; Sokolov, A A; Ternov, I M; Khalilov, V R [Moskovskij Gosudarstvennyj Univ. (USSR)

1975-03-11

When electrons move in a magnetic field, synchrotron radiation gives rise to transitions accompanied by the electron spin reorientation. In this case, it is essential that the transition probability depends on the spin orientation; as a result electron polarization takes place with the spin orientation being predominantly opposite to the direction of the magnetic field. This effect has been called ''radiative self-polarization of electrons''. The present work is concerned with the question how the choice of the spin operator will affect the self-polarization degree and relaxation time. The problem has been solved for a vector spin operator.

Revealing Fundamental Interactions: the Role of Polarized Positrons and Electrons at the Linear Collider

International Nuclear Information System (INIS)

Moortgat-Pick, G.; CERN, Durham U. IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke, J.; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.

2005-01-01

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization

Revealing Fundamental Interactions: the Role of Polarized Positrons and Electrons at the Linear Collider

Energy Technology Data Exchange (ETDEWEB)

Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv

2005-07-06

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

Production of positive pions from polarized protons by linearly polarized photons in the energy region 300--420 MeV

Energy Technology Data Exchange (ETDEWEB)

Get' man, V.A.; Gorbenko, V.G.; Grushin, V.F.; Derkach, A.Y.; Zhebrovskii, Y.V.; Karnaukhov, I.M.; Kolesnikov, L.Y.; Luchanin, A.A.; Rubashkin, A.L.; Sanin, V.M.; Sorokin, P.V.; Sporov, E.A.; Telegin, Y.N.; Shalatskii, S.V.

1980-10-01

A technique for measurement of the polarization observables ..sigma.., P, and T for the reaction ..gamma..p..-->..n..pi../sup +/ in a doubly polarized experiment (polarized proton target + linearly polarized photon beam) is described. Measurements of the angular distributions of these observables in the range of pion emission angles 30--150/sup 0/ are presented for four photon energies from 300 to 420 MeV. Inclusion of the new experimental data in an energy-independent multipole analysis of photoproduction from protons permits a more reliable selection of solutions to be made.

Biquaternion beamspace with its application to vector-sensor array direction findings and polarization estimations

Science.gov (United States)

Li, Dan; Xu, Feng; Jiang, Jing Fei; Zhang, Jian Qiu

2017-12-01

In this paper, a biquaternion beamspace, constructed by projecting the original data of an electromagnetic vector-sensor array into a subspace of a lower dimension via a quaternion transformation matrix, is first proposed. To estimate the direction and polarization angles of sources, biquaternion beamspace multiple signal classification (BB-MUSIC) estimators are then formulated. The analytical results show that the biquaternion beamspaces offer us some additional degrees of freedom to simultaneously achieve three goals. One is to save the memory spaces for storing the data covariance matrix and reduce the computation efforts of the eigen-decomposition. Another is to decouple the estimations of the sources' polarization parameters from those of their direction angles. The other is to blindly whiten the coherent noise of the six constituent antennas in each vector-sensor. It is also shown that the existing biquaternion multiple signal classification (BQ-MUSIC) estimator is a specific case of our BB-MUSIC ones. The simulation results verify the correctness and effectiveness of the analytical ones.

Non-coaxial superposition of vector vortex beams.

Science.gov (United States)

Aadhi, A; Vaity, Pravin; Chithrabhanu, P; Reddy, Salla Gangi; Prabakar, Shashi; Singh, R P

2016-02-10

Vector vortex beams are classified into four types depending upon spatial variation in their polarization vector. We have generated all four of these types of vector vortex beams by using a modified polarization Sagnac interferometer with a vortex lens. Further, we have studied the non-coaxial superposition of two vector vortex beams. It is observed that the superposition of two vector vortex beams with same polarization singularity leads to a beam with another kind of polarization singularity in their interaction region. The results may be of importance in ultrahigh security of the polarization-encrypted data that utilizes vector vortex beams and multiple optical trapping with non-coaxial superposition of vector vortex beams. We verified our experimental results with theory.

Dispersion relation of linearly polarized strong electromagnetic waves

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Massaglia, S [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Dobrowolny, M [Comitato Nazionale per l' Energia Nucleaire, Frascati (Italy). Lab. Plasma Spazio

1975-12-15

A numerical study is presented of the dispersion relation of linearly polarized strong electromagnetic waves in a cold electron plasma. The nonlinear effects introduced by the relativistic motion of electrons are: (1) the dispersion relation depends explicitly on the field strength ..cap alpha..=eE/sub 0//mc..omega../sub 0/, and (2) the propagation of modes with frequencies below the formal electron plasma frequency is allowed.

Observations on the variability of linear polarization in late-type dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Huovelin, J.; Linnaluoto, S.; Tuominen, I.; Virtanen, H.

1989-04-01

Broadband (UBV) linear polarimetric observations of a sample of late-type (F7-K5) dwarfs are reported. The observations include ten stars and extend over a maximum of 20 nights. Seven stars show significant temporal variability of polarization, which could be interpreted as rotational modulation due to slowly varying magnetic regions. Magnetic intensification in saturated Zeeman sensitive absorption lines is suggested as the dominant effect connecting linear polarization with magnetic activity in the most active single late-type dwarfs, while the wavelength dependence in the less active stars could also be due to a combination of Rayleigh and Thomson scattering.

Optical asymmetric cryptography based on elliptical polarized light linear truncation and a numerical reconstruction technique.

Science.gov (United States)

Lin, Chao; Shen, Xueju; Wang, Zhisong; Zhao, Cheng

2014-06-20

We demonstrate a novel optical asymmetric cryptosystem based on the principle of elliptical polarized light linear truncation and a numerical reconstruction technique. The device of an array of linear polarizers is introduced to achieve linear truncation on the spatially resolved elliptical polarization distribution during image encryption. This encoding process can be characterized as confusion-based optical cryptography that involves no Fourier lens and diffusion operation. Based on the Jones matrix formalism, the intensity transmittance for this truncation is deduced to perform elliptical polarized light reconstruction based on two intensity measurements. Use of a quick response code makes the proposed cryptosystem practical, with versatile key sensitivity and fault tolerance. Both simulation and preliminary experimental results that support theoretical analysis are presented. An analysis of the resistance of the proposed method on a known public key attack is also provided.

vSmartMOM: A vector matrix operator method-based radiative transfer model linearized with respect to aerosol properties

International Nuclear Information System (INIS)

Sanghavi, Suniti; Davis, Anthony B.; Eldering, Annmarie

2014-01-01

In this paper, we build up on the scalar model smartMOM to arrive at a formalism for linearized vector radiative transfer based on the matrix operator method (vSmartMOM). Improvements have been made with respect to smartMOM in that a novel method of computing intensities for the exact viewing geometry (direct raytracing) without interpolation between quadrature points has been implemented. Also, the truncation method employed for dealing with highly peaked phase functions has been changed to a vector adaptation of Wiscombe's delta-m method. These changes enable speedier and more accurate radiative transfer computations by eliminating the need for a large number of quadrature points and coefficients for generalized spherical functions. We verify our forward model against the benchmarking results of Kokhanovsky et al. (2010) [22]. All non-zero Stokes vector elements are found to show agreement up to mostly the seventh significant digit for the Rayleigh atmosphere. Intensity computations for aerosol and cloud show an agreement of well below 0.03% and 0.05% at all viewing angles except around the solar zenith angle (60°), where most radiative models demonstrate larger variances due to the strongly forward-peaked phase function. We have for the first time linearized vector radiative transfer based on the matrix operator method with respect to aerosol optical and microphysical parameters. We demonstrate this linearization by computing Jacobian matrices for all Stokes vector elements for a multi-angular and multispectral measurement setup. We use these Jacobians to compare the aerosol information content of measurements using only the total intensity component against those using the idealized measurements of full Stokes vector [I,Q,U,V] as well as the more practical use of only [I,Q,U]. As expected, we find for the considered example that the accuracy of the retrieved parameters improves when the full Stokes vector is used. The information content for the full Stokes

Alteration in non-classicality of light on passing through a linear polarization beam splitter

Science.gov (United States)

Shukla, Namrata; Prakash, Ranjana

2016-06-01

We observe the polarization squeezing in the mixture of a two mode squeezed vacuum and a simple coherent light through a linear polarization beam splitter. Squeezed vacuum not being squeezed in polarization, generates polarization squeezed light when superposed with coherent light. All the three Stokes parameters of the light produced on the output port of polarization beam splitter are found to be squeezed and squeezing factor also depends upon the parameters of coherent light.

Polarization properties of below-threshold harmonics from aligned molecules H2+ in linearly polarized laser fields.

Science.gov (United States)

Dong, Fulong; Tian, Yiqun; Yu, Shujuan; Wang, Shang; Yang, Shiping; Chen, Yanjun

2015-07-13

We investigate the polarization properties of below-threshold harmonics from aligned molecules in linearly polarized laser fields numerically and analytically. We focus on lower-order harmonics (LOHs). Our simulations show that the ellipticity of below-threshold LOHs depends strongly on the orientation angle and differs significantly for different harmonic orders. Our analysis reveals that this LOH ellipticity is closely associated with resonance effects and the axis symmetry of the molecule. These results shed light on the complex generation mechanism of below-threshold harmonics from aligned molecules.

Broad-band linear polarization and magnetic intensification in rotating magnetic stars

International Nuclear Information System (INIS)

Degl'Innocenti, M.L.; Calamai, G.; Degl'Innocenti, E.L.; Patriarchi, P.

1981-01-01

Magnetic intensification is proposed as a mechanism to explain the general features of the variable broad-band linear polarization emerging from rotating magnetic stars. This mechanism is studied in detail, and some efforts are made to investigate the wide variety of polarization diagrams that can result from it. Theoretical results are compared with direct observations of the variable magnetic star 53 Cam to determine its geometric and magnetic configuration

Photodisintegration of aligned deuterons at astrophysical energies using linearly polarized photons

International Nuclear Information System (INIS)

Shilpashree, S.P.; Sirsi, Swarnamala; Ramachandran, G.

2013-01-01

Following the model independent approach to deuteron photodisintegration with linearly polarized γ-rays, we show that the measurements of the tensor analyzing powers on aligned deuterons along with the differential cross-section involve five different linear combinations of the isovector E1 ν j ; j = 0, 1, 2 amplitudes interfering with the isoscalar M1 s and E2 s amplitudes. This is of current interest in view of the recent experimental finding [M. A. Blackston et al., Phys. Rev. C78 (2008) 034003] that the three E1 ν j amplitudes are distinct and also the reported experimental observation [B. D. Sawatzky, Ph.D. thesis, University of Virginia (2005)] on the front–back (polar angle) asymmetry in the differential cross-section. (author)

Generation of linearly polarized resonant transition radiation X-ray beam

International Nuclear Information System (INIS)

Yajima, Kazuaki; Awata, Takaaki; Ikeda, Mitsuharu; Ikeda, Kenichi; Yogo, Akifumi; Itoh, Akio; Imanishi, Nobutsugu

2000-01-01

We have proposed a method to generate almost linearly polarized resonant transition radiation X rays by using a rectangular slit placed on an electron beam axis. Our calculation predicted that the linearity is 93.5% for the resonant transition radiation X-ray beam extracted through a slit of 0.5 mrad long and 0.2 mrad wide in case of 1-GeV electron beam irradiating a 7.5-μm thick Kapton foil stack. (author)

Generation of linearly polarized resonant transition radiation X-ray beam

Energy Technology Data Exchange (ETDEWEB)

Yajima, Kazuaki; Awata, Takaaki; Ikeda, Mitsuharu; Ikeda, Kenichi; Yogo, Akifumi; Itoh, Akio; Imanishi, Nobutsugu [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

2000-03-01

We have proposed a method to generate almost linearly polarized resonant transition radiation X rays by using a rectangular slit placed on an electron beam axis. Our calculation predicted that the linearity is 93.5% for the resonant transition radiation X-ray beam extracted through a slit of 0.5 mrad long and 0.2 mrad wide in case of 1-GeV electron beam irradiating a 7.5-{mu}m thick Kapton foil stack. (author)

Polarimetry and photometry of the AM Her polar

Energy Technology Data Exchange (ETDEWEB)

Efimov, Yu S; Shakhovskoj, N M

1982-01-01

The results of the polarization observations and photometry of AM Her obtained during 11 nights from April to September 1978 are presented. The observations were carried out in V spectral region with time resolution of about four minutes. The results of measurements are in agreement with previous observations. The polarization maximum, being mostly on the 1.3 % level, was rising up to 2 % only at an active state of the star. No correlation was found between rapid variations of light and linear polarization at an inactive state of the star. The phase dependence of mean polarization parameters is revealed. The displaced dipole magnetic field with different strength on the poles is assumed for the polar model to interpret the vector diagram of polarization.

The Role of polarized positrons and electrons in revealing fundamental interactions at the linear collider

CERN Document Server

Moortgat-Pick, G.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke, J.; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, Tyler McMillan; Dreiner, H.K.; Eberl, H.; Ellis, John R.; Flottmann, K.; Fraas, H.; Franco-Sollova, F.; Franke, F.; Freitas, A.; Goodson, J.; Gray, J.; Han, A.; Heinemeyer, S.; Hesselbach, S.; Hirose, T.; Hohenwarter-Sodek, K.; Juste, A.; Kalinowski, J.; Kernreiter, T.; Kittel, O.; Kraml, S.; Langenfeld, U.; Majerotto, W.; Martinez, A.; Martyn, H.U.; Mikhailichenko, A.; Milstene, C.; Menges, W.; Meyners, N.; Monig, K.; Moffeit, K.; Moretti, S.; Nachtmann, O.; Nagel, F.; Nakanishi, T.; Nauenberg, U.; Nowak, H.; Omori, T.; Osland, P.; Pankov, A.A.; Paver, N.; Pitthan, R.; Poschl, R.; Porod, W.; Proulx, J.; Richardson, P.; Riemann, S.; Rindani, S.D.; Rizzo, T.G.; Schalicke, A.; Schuler, P.; Schwanenberger, C.; Scott, D.; Sheppard, J.; Singh, R.K.; Sopczak, A.; Spiesberger, H.; Stahl, A.; Steiner, H.; Wagner, A.; Weber, A.M.; Weiglein, G.; Wilson, G.W.; Woods, M.; Zerwas, P.; Zhang, J.; Zomer, F.

2008-01-01

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

The Role of polarized positrons and electrons in revealing fundamental interactions at the linear collider

Energy Technology Data Exchange (ETDEWEB)

Moortgat-Pick, G.; /CERN /Durham U., IPPP; Abe, T.; Alexander, G.; Ananthanarayan, B.; Babich, A.A.; Bharadwaj, V.; Barber, D.; Bartl, A.; Brachmann, A.; Chen, S.; Clarke,; Clendenin, J.E.; Dainton, J.; Desch, K.; Diehl, M.; Dobos, B.; Dorland, T.; Eberl, H.; Ellis, John R.; Flottman, K.; Frass, H.; /CERN /Durham U., IPPP /Colorado U. /Tel-Aviv

2005-07-01

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

The application of the fall-vector method in decomposition schemes for the solution of integer linear programming problems

International Nuclear Information System (INIS)

Sergienko, I.V.; Golodnikov, A.N.

1984-01-01

This article applies the methods of decompositions, which are used to solve continuous linear problems, to integer and partially integer problems. The fall-vector method is used to solve the obtained coordinate problems. An algorithm of the fall-vector is described. The Kornai-Liptak decomposition principle is used to reduce the integer linear programming problem to integer linear programming problems of a smaller dimension and to a discrete coordinate problem with simple constraints

Interaction of low-intensity linearly polarized laser radiation with living tissues: effects on tissular acceleration of skin wound healing

International Nuclear Information System (INIS)

Ribeiro, Martha Simoes

2000-01-01

According to the Maxwell's equations to optical properties of surfaces, the energy deposition efficiency in a microroughness interface depends on the electrical field polarization component. Considering a linearly polarized beam, this efficiency will depend on the roughness parameters to p-polarized light and it will not depend on such parameters to s-polarized light. In this work it was investigated the effects of low-intensity, linearly polarized He-Ne laser beam on skin wounds healing, considering two orthogonal directions of polarization. We have considered a preferential axis as the animals' spinal column and we aligned the linear laser polarization first parallel, then perpendicular to this direction. Burns about 6 mm in diameter were created with liquid N 2 on the back of the animals and the lesions were irradiated on days 3, 7, 10 and 14 post-wounding, D= 1,0 J/cm 2 . Control lesions were not irradiated. The theoretical model consisted in describing linearly polarized light propagation in biological tissues using transport theory. The degree of polarization was measured in normal and pathological skin samples. It was verified that linearly polarized light can survive in the superficial layers of skin and it can be more preserved in skin under pathological condition when compared with health skin. The analysis of skin wound healing process has demonstrated that the relative direction of the laser polarization plays an important role on the wound healing process by light microscopy, transmission electron microscopy and radioautography. (author)

Scattering of polarized electrons from polarized targets: Coincidence reactions and prescriptions for polarized half-off-shell single-nucleon cross sections

International Nuclear Information System (INIS)

Caballero, J.A.; Massachusetts Inst. of Tech., Cambridge, MA; Donnelly, T.W.; Massachusetts Inst. of Tech., Cambridge, MA; Poulis, G.I.; Massachusetts Inst. of Tech., Cambridge, MA

1993-01-01

Coincidence reactions of the type vector A( vector e, e'N)B involving the scattering of polarized electrons from polarized targets are discussed within the context of the plane-wave impulse approximation. Prescriptions are developed for polarized half-off single-nucleon cross sections; the different prescriptions are compared for typical quasi-free kinematics. Illustrative results are presented for coincidence polarized electron scattering from typical polarized nuclei. (orig.)

Versatile generation of optical vector fields and vector beams using a non-interferometric approach.

Science.gov (United States)

Tripathi, Santosh; Toussaint, Kimani C

2012-05-07

We present a versatile, non-interferometric method for generating vector fields and vector beams which can produce all the states of polarization represented on a higher-order Poincaré sphere. The versatility and non-interferometric nature of this method is expected to enable exploration of various exotic properties of vector fields and vector beams. To illustrate this, we study the propagation properties of some vector fields and find that, in general, propagation alters both their intensity and polarization distribution, and more interestingly, converts some vector fields into vector beams. In the article, we also suggest a modified Jones vector formalism to represent vector fields and vector beams.

Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

Science.gov (United States)

Boll, D. I. R.; Fojón, O. A.

2017-12-01

We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

W-Band Circularly Polarized TE11 Mode Transducer

Science.gov (United States)

Zhan, Mingzhou; He, Wangdong; Wang, Lei

2018-06-01

This paper presents a balanced sidewall exciting approach to realize the circularly polarized TE11 mode transducer. We used a voltage vector transfer matrix to establish the relationship between input and output vectors, then we analyzed amplitude and phase errors to estimate the isolation of degenerate mode. A mode transducer with a sidewall exciter was designed based on the results. In the 88-100 GHz frequency range, the simulated axial ratio is less than 1.05 and the isolation of linearly polarization TE11 mode is higher than 30 dBc. In back-to-back measurements, the return loss is generally greater than 20 dB with a typical insertion loss of 1.2 dB. Back-to-back transmission measurements are in excellent agreement with simulations.

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

Energy Technology Data Exchange (ETDEWEB)

Beckmann, Moritz

2013-12-15

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

Polarized positron sources for the future linear colliders

International Nuclear Information System (INIS)

Chaikovska, I.

2012-01-01

This thesis introduces the polarized positron source as one of the key element of the future Linear Collider (LC). In this context, the different schemes of the polarized positron source are described highlighting the main issues in this technology. In particular, the main focus is on the Compton based positron source adopted by the CLIC as a preferred option for the future positron source upgrade. In this case, the circularly polarized high energy gamma rays resulting from Compton scattering are directed to a production target where an electromagnetic cascade gives rise to the production of positrons by e + -e - pair conversion. To increase the efficiency of the gamma ray production stage, a multiple collision point line integrated in energy recovery linac is proposed. The simulations of the positron production, capture and primary acceleration allow to estimate the positron production efficiency and provide a simple parametrization of the Compton based polarized positron source in the view of the future LC requirements. The storage ring based Compton source option, so-called Compton ring, is also described. The main constraint of this scheme is given by the beam dynamics resulting in the large energy spread and increased bunch length affecting the gamma ray production rate. An original theoretical contribution is shown to calculate the energy spread induced by Compton scattering. Moreover, an experiment to test the gamma ray production by Compton scattering using a state-of-art laser system developed at LAL has been conducted in the framework of the 'Mighty Laser' project at the ATF, KEK. The experimental layout as well as the main results obtained are discussed in details. The studies carried out in this thesis show that the polarized positron source based on Compton scattering is a promising candidate for the future LC polarized positron source. (author)

Azimuthal asymmetry in processes of nonlinear QED for linearly polarized photon

International Nuclear Information System (INIS)

Bajer, V.N.; Mil'shtejn, A.I.

1994-01-01

Cross sections of nonlinear QED processes (photon-photon scattering, photon splitting in a Coulomb field, and Delbrueck scattering) are considered for linearly polarized initial photon. The cross sections have sizeable azimuthal asymmetry. 15 refs.; 3 figs

A Multibeam Dual-Band Orthogonal Linearly Polarized Antenna Array for Satellite Communication on the Move

Directory of Open Access Journals (Sweden)

Yi Liu

2015-01-01

Full Text Available The design and simulation of a 10 × 8 multibeam dual-band orthogonal linearly polarized antenna array operating at Ku-band are presented for transmit-receive applications. By using patches with different coupling methods as elements, both perpendicular polarization in 12.25–12.75 GHz band and horizontal polarization in 14.0–14.5 GHz band are realized in a shared antenna aperture. A microstrip Rotman lens is employed as the beamforming network with 7 input ports, which can generate a corresponding number of beams to cover −30°–30° with 5 dB beamwidth along one dimension. This type of multibeam orthogonal linearly polarized planar antenna is a good candidate for satellite communication (SatCom.

Polarization transfer in (d-vector,n-vector) reactions

International Nuclear Information System (INIS)

Walter, R.L.; Tornow, W.

1986-01-01

The status of the measurements and the role of polarization transfer coefficients for (d/sup →/,n/sup →/) reactions is reviewed. Emphasis is given to reactions, involving light-nuclei systems. The importance of (d/sup →/,n/sup →/) reactions as sources of polarized neutrons is pointed out

Spin information from vector-meson decay in photoproduction

International Nuclear Information System (INIS)

Kloet, W.M.; Chiang, W.; Tabakin, F.

1998-01-01

For the photoproduction of vector mesons, all single and double spin observables involving vector-meson two-body decays are defined consistently in the γN center-of-mass frame. These definitions yield a procedure for extracting physically meaningful single and double spin observables that are subject to known rules concerning their angle and energy evolution. As part of this analysis, we show that measuring the two-meson decay of a photo produced ρ or φ does not determine the vector meson's vector polarization, but only its tensor polarization. The vector meson decay into lepton pairs is also insensitive to the vector meson's vector polarization, unless one measures the spin of one of the leptons. Similar results are found for all double spin observables which involve observation of vector-meson decay. To access the vector meson's vector polarization, one therefore needs to either measure the spin of the decay leptons, make an analysis of the background interference effects, or relate the vector meson's vector polarization to other accessible spin observables. copyright 1998 The American Physical Society

Neutron polarization

International Nuclear Information System (INIS)

Firk, F.W.K.

1976-01-01

Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

KAUST Repository

Sallam, M. O.

2011-07-01

Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

Measurement of the topological charge and index of vortex vector optical fields with a space-variant half-wave plate.

Science.gov (United States)

Liu, Gui-Geng; Wang, Ke; Lee, Yun-Han; Wang, Dan; Li, Ping-Ping; Gou, Fangwang; Li, Yongnan; Tu, Chenghou; Wu, Shin-Tson; Wang, Hui-Tian

2018-02-15

Vortex vector optical fields (VVOFs) refer to a kind of vector optical field with an azimuth-variant polarization and a helical phase, simultaneously. Such a VVOF is defined by the topological index of the polarization singularity and the topological charge of the phase vortex. We present a simple method to measure the topological charge and index of VVOFs by using a space-variant half-wave plate (SV-HWP). The geometric phase grating of the SV-HWP diffracts a VVOF into ±1 orders with orthogonally left- and right-handed circular polarizations. By inserting a polarizer behind the SV-HWP, the two circular polarization states project into the linear polarization and then interfere with each other to form the interference pattern, which enables the direct measurement of the topological charge and index of VVOFs.

Variation of linear and circular polarization persistence for changing field of view and collection area in a forward scattering environment

Science.gov (United States)

van der Laan, John D.; Wright, Jeremy B.; Scrymgeour, David A.; Kemme, Shanalyn A.; Dereniak, Eustace L.

2016-05-01

We present experimental and simulation results for a laboratory-based forward-scattering environment, where 1 μm diameter polystyrene spheres are suspended in water to model the optical scattering properties of fog. Circular polarization maintains its degree of polarization better than linear polarization as the optical thickness of the scattering environment increases. Both simulation and experiment quantify circular polarization's superior persistence, compared to that of linear polarization, and show that it is much less affected by variations in the field of view and collection area of the optical system. Our experimental environment's lateral extent was physically finite, causing a significant difference between measured and simulated degree of polarization values for incident linearly polarized light, but not for circularly polarized light. Through simulation we demonstrate that circular polarization is less susceptible to the finite environmental extent as well as the collection optic's limiting configuration.

Considering polarization in MODIS-based cloud property retrievals by using a vector radiative transfer code

International Nuclear Information System (INIS)

Yi, Bingqi; Huang, Xin; Yang, Ping; Baum, Bryan A.; Kattawar, George W.

2014-01-01

In this study, a full-vector, adding–doubling radiative transfer model is used to investigate the influence of the polarization state on cloud property retrievals from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations. Two sets of lookup tables (LUTs) are developed for the retrieval purposes, both of which provide water cloud and ice cloud reflectivity functions at two wavelengths in various sun-satellite viewing geometries. However, only one of the LUTs considers polarization. The MODIS reflectivity observations at 0.65 μm (band 1) and 2.13 μm (band 7) are used to infer the cloud optical thickness and particle effective diameter, respectively. Results indicate that the retrievals for both water cloud and ice cloud show considerable sensitivity to polarization. The retrieved water and ice cloud effective diameter and optical thickness differences can vary by as much as ±15% due to polarization state considerations. In particular, the polarization state has more influence on completely smooth ice particles than on severely roughened ice particles. - Highlights: • Impact of polarization on satellite-based retrieval of water/ice cloud properties is studied. • Inclusion of polarization can change water/ice optical thickness and effective diameter values by up to ±15%. • Influence of polarization on cloud property retrievals depends on sun-satellite viewing geometries

Colloidal InP/ZnS core-shell nanocrystals studied by linearly and circularly polarized photoluminescence

International Nuclear Information System (INIS)

Langof, L.; Fradkin, L.; Ehrenfreund, E.; Lifshitz, E.; Micic, O.I.; Nozik, A.J.

2004-01-01

The magneto-optical properties of InP/ZnS core-shell nanocrystals (NCs) were investigated by measuring the degree of linear and circular polarization of photoluminescence (PL) spectra, in the presence of an external magnetic field under resonant or non-resonant excitation. The linearly polarized PL data strongly indicate that InP/ZnS NCs have a prolongated shape. The resonant-excited circularly polarized PL decay curves indicate that the spin relaxation time of the studied samples is shorter than the radiative lifetime of their exciton. Furthermore, the magnetic field-induced circularly polarized PL process reveals an exciton g factor (g ex ) of 0.55. Thus, such studies may serve as a tool to directly estimate the NC's shape anisotropy and to determine the g-factor of charge carriers and excitons in those NCs

Colloidal InP/ZnS core shell nanocrystals studied by linearly and circularly polarized photoluminescence

Science.gov (United States)

Langof, L.; Fradkin, L.; Ehrenfreund, E.; Lifshitz, E.; Micic, O. I.; Nozik, A. J.

2004-02-01

The magneto-optical properties of InP/ZnS core-shell nanocrystals (NCs) were investigated by measuring the degree of linear and circular polarization of photoluminescence (PL) spectra, in the presence of an external magnetic field under resonant or non-resonant excitation. The linearly polarized PL data strongly indicate that InP/ZnS NCs have a prolongated shape. The resonant-excited circularly polarized PL decay curves indicate that the spin relaxation time of the studied samples is shorter than the radiative lifetime of their exciton. Furthermore, the magnetic field-induced circularly polarized PL process reveals an exciton g factor ( gex) of 0.55. Thus, such studies may serve as a tool to directly estimate the NC's shape anisotropy and to determine the g-factor of charge carriers and excitons in those NCs.

DIRECT OBSERVATION OF SOLAR CORONAL MAGNETIC FIELDS BY VECTOR TOMOGRAPHY OF THE CORONAL EMISSION LINE POLARIZATIONS

International Nuclear Information System (INIS)

Kramar, M.; Lin, H.; Tomczyk, S.

2016-01-01

We present the first direct “observation” of the global-scale, 3D coronal magnetic fields of Carrington Rotation (CR) Cycle 2112 using vector tomographic inversion techniques. The vector tomographic inversion uses measurements of the Fe xiii 10747 Å Hanle effect polarization signals by the Coronal Multichannel Polarimeter (CoMP) and 3D coronal density and temperature derived from scalar tomographic inversion of Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) coronal emission lines (CELs) intensity images as inputs to derive a coronal magnetic field model that best reproduces the observed polarization signals. While independent verifications of the vector tomography results cannot be performed, we compared the tomography inverted coronal magnetic fields with those constructed by magnetohydrodynamic (MHD) simulations based on observed photospheric magnetic fields of CR 2112 and 2113. We found that the MHD model for CR 2112 is qualitatively consistent with the tomography inverted result for most of the reconstruction domain except for several regions. Particularly, for one of the most noticeable regions, we found that the MHD simulation for CR 2113 predicted a model that more closely resembles the vector tomography inverted magnetic fields. In another case, our tomographic reconstruction predicted an open magnetic field at a region where a coronal hole can be seen directly from a STEREO-B/EUVI image. We discuss the utilities and limitations of the tomographic inversion technique, and present ideas for future developments

Linear minimax estimation for random vectors with parametric uncertainty

KAUST Repository

Bitar, E

2010-06-01

In this paper, we take a minimax approach to the problem of computing a worst-case linear mean squared error (MSE) estimate of X given Y , where X and Y are jointly distributed random vectors with parametric uncertainty in their distribution. We consider two uncertainty models, PA and PB. Model PA represents X and Y as jointly Gaussian whose covariance matrix Λ belongs to the convex hull of a set of m known covariance matrices. Model PB characterizes X and Y as jointly distributed according to a Gaussian mixture model with m known zero-mean components, but unknown component weights. We show: (a) the linear minimax estimator computed under model PA is identical to that computed under model PB when the vertices of the uncertain covariance set in PA are the same as the component covariances in model PB, and (b) the problem of computing the linear minimax estimator under either model reduces to a semidefinite program (SDP). We also consider the dynamic situation where x(t) and y(t) evolve according to a discrete-time LTI state space model driven by white noise, the statistics of which is modeled by PA and PB as before. We derive a recursive linear minimax filter for x(t) given y(t).

Anomalous property of coherent bremsstrahlung linear polarization of relativistic electrons in a crystal

International Nuclear Information System (INIS)

Lapko, V.P.; Nasonov, N.N.; Truten', V.I.

1993-01-01

Polarization and spectral-and-angular properties of γ-radiation of the relativistic electron flux moving in a crystal under uncorrelated collisions with crystal atomic chains, are studied theoretically. Direction of linear polarization of radiation is shown to vary with energy of emitted photon. Reasons of occurrence of this effect are discussed. The results of numerical calculations demonstrating the possibility to form an intensive source of polarized γ-quanta on the basis of coherent radiation of relativistic electrons during low-angular scattering at crystal atom chains, are given

Proposed method to produce a highly polarized e+ beam for future linear colliders

International Nuclear Information System (INIS)

Okugi, Toshiyuki; Chiba, Masami; Kurihara, Yoshimasa

1996-01-01

We propose a method to produce a spin-polarized e + beam using e + e - pair-creation by circularly polarized photons. Assuming Compton scattering of an unpolarized e - beam and circularly polarized laser light, scattered γ-rays at the high end of the energy spectrum are also circularly polarized. If those γ-rays are utilized to create e ± pairs on a thin target, the spin-polarization is preserved for e + 's at the high end of their energy spectrum. By using the injector linac of Accelerator Test Facility at KEK and a commercially available Nd:YAG pulse laser, we can expect about 10 5 polarized e + 's per second with a degree of polarization of 80% and a kinetic energy of 35-80 MeV. The apparatus for creation and measurement of polarized e + 's is being constructed. We present new idea for possible application of our method to future linear colliders by utilizing a high-power CO 2 laser. (author)

Vector-valued measure and the necessary conditions for the optimal control problems of linear systems

International Nuclear Information System (INIS)

Xunjing, L.

1981-12-01

The vector-valued measure defined by the well-posed linear boundary value problems is discussed. The maximum principle of the optimal control problem with non-convex constraint is proved by using the vector-valued measure. Especially, the necessary conditions of the optimal control of elliptic systems is derived without the convexity of the control domain and the cost function. (author)

Genetic dissection reveals two separate retinal substrates for polarization vision in Drosophila.

Science.gov (United States)

Wernet, Mathias F; Velez, Mariel M; Clark, Damon A; Baumann-Klausener, Franziska; Brown, Julian R; Klovstad, Martha; Labhart, Thomas; Clandinin, Thomas R

2012-01-10

Linearly polarized light originates from atmospheric scattering or surface reflections and is perceived by insects, spiders, cephalopods, crustaceans, and some vertebrates. Thus, the neural basis underlying how this fundamental quality of light is detected is of broad interest. Morphologically unique, polarization-sensitive ommatidia exist in the dorsal periphery of many insect retinas, forming the dorsal rim area (DRA). However, much less is known about the retinal substrates of behavioral responses to polarized reflections. Drosophila exhibits polarotactic behavior, spontaneously aligning with the e-vector of linearly polarized light, when stimuli are presented either dorsally or ventrally. By combining behavioral experiments with genetic dissection and ultrastructural analyses, we show that distinct photoreceptors mediate the two behaviors: inner photoreceptors R7+R8 of DRA ommatidia are necessary and sufficient for dorsal polarotaxis, whereas ventral responses are mediated by combinations of outer and inner photoreceptors, both of which manifest previously unknown features that render them polarization sensitive. Drosophila uses separate retinal pathways for the detection of linearly polarized light emanating from the sky or from shiny surfaces. This work establishes a behavioral paradigm that will enable genetic dissection of the circuits underlying polarization vision. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anatomical Reconstruction and Functional Imaging Reveal an Ordered Array of Skylight Polarization Detectors in Drosophila.

Science.gov (United States)

Weir, Peter T; Henze, Miriam J; Bleul, Christiane; Baumann-Klausener, Franziska; Labhart, Thomas; Dickinson, Michael H

2016-05-11

Many insects exploit skylight polarization as a compass cue for orientation and navigation. In the fruit fly, Drosophila melanogaster, photoreceptors R7 and R8 in the dorsal rim area (DRA) of the compound eye are specialized to detect the electric vector (e-vector) of linearly polarized light. These photoreceptors are arranged in stacked pairs with identical fields of view and spectral sensitivities, but mutually orthogonal microvillar orientations. As in larger flies, we found that the microvillar orientation of the distal photoreceptor R7 changes in a fan-like fashion along the DRA. This anatomical arrangement suggests that the DRA constitutes a detector for skylight polarization, in which different e-vectors maximally excite different positions in the array. To test our hypothesis, we measured responses to polarized light of varying e-vector angles in the terminals of R7/8 cells using genetically encoded calcium indicators. Our data confirm a progression of preferred e-vector angles from anterior to posterior in the DRA, and a strict orthogonality between the e-vector preferences of paired R7/8 cells. We observed decreased activity in photoreceptors in response to flashes of light polarized orthogonally to their preferred e-vector angle, suggesting reciprocal inhibition between photoreceptors in the same medullar column, which may serve to increase polarization contrast. Together, our results indicate that the polarization-vision system relies on a spatial map of preferred e-vector angles at the earliest stage of sensory processing. The fly's visual system is an influential model system for studying neural computation, and much is known about its anatomy, physiology, and development. The circuits underlying motion processing have received the most attention, but researchers are increasingly investigating other functions, such as color perception and object recognition. In this work, we investigate the early neural processing of a somewhat exotic sense, called

Colloidal InP/ZnS core-shell nanocrystals studied by linearly and circularly polarized photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Langof, L.; Fradkin, L.; Ehrenfreund, E.; Lifshitz, E.; Micic, O.I.; Nozik, A.J

2004-02-16

The magneto-optical properties of InP/ZnS core-shell nanocrystals (NCs) were investigated by measuring the degree of linear and circular polarization of photoluminescence (PL) spectra, in the presence of an external magnetic field under resonant or non-resonant excitation. The linearly polarized PL data strongly indicate that InP/ZnS NCs have a prolongated shape. The resonant-excited circularly polarized PL decay curves indicate that the spin relaxation time of the studied samples is shorter than the radiative lifetime of their exciton. Furthermore, the magnetic field-induced circularly polarized PL process reveals an exciton g factor (g{sub ex}) of 0.55. Thus, such studies may serve as a tool to directly estimate the NC's shape anisotropy and to determine the g-factor of charge carriers and excitons in those NCs.

Observations of linear polarization in deep minima of WW Vul

International Nuclear Information System (INIS)

Grinin, V.P.; Kiselev, N.N.; Minikulov, N.Kh.; Chernova, G.P.; AN Tadzhikskoj SSR, Dushanbe. Inst. Astrofiziki)

1988-01-01

In the course of patrol photometric and polarimetric observations of WW Vul, initiated in 1986 in the Crimea and Sanglok, a broad photometrical minimum was registered, the deepest part of which being composed of three consecutive weakenings of brightness. The increase of linear polarization up to 5-6% (in V band) was observed in each of them. The analysis of the observational data shows, that the main part of polarized light occurs due to scattering of star radiation by dust particles of the circumstellar envelope. the contribution of this polarized radiation increases when the occultation of the star by the opaque dust cloud weakenes the direct (non-polarized) radiation of the star. Additional source of light polarization is the alignement of non-spherical particles in the dust cloud, which are responsible for occultation. Some arguments are given in favor to the idea, that the asymmetry axis of the circumstellar disc - like envelope of WW Vul is oriented parallel to the local interstellar magnetic field. If and alignment of non-spherical particles is caused by magnetic field of the disc, magnetic lines should follow the plane of the disc. The observations confirm the hypothesis, that the source of blue emission, observed in deep minima of such type stars, is the scattered radiation of circumstellar dust

Use of Linear and Circular Polarization: The Secret LCD Screen and 3D Cinema

Science.gov (United States)

Richtberg, Stefan; Girwidz, Raimund

2017-01-01

References to everyday life are important for teaching physics. Discussing polarization phenomena, liquid crystal displays (LCDs) and 3D cinemas provide such references. In this paper we describe experiments to support students' understanding of linearly polarized light as well as the phenomenon of inverted colors using a secret LCD screen.…

An L-Band Polarized Electron PWT Photoinjector for the International Linear Collider (ILC)

CERN Document Server

Yu, David; Chen Ping; Lundquist, Martin; Luo, Yan; Smirnov, Alexei Yu

2005-01-01

A multi-cell, standing-wave, L-band, p-mode, plane-wave-transformer (PWT) photoinjector with an integrated photocathode in a novel linac structure is proposed by DULY Research Inc. as a polarized electron source. The PWT photoinjector is capable of operation in ultra high vacuum and moderate field gradient. Expected performance of an L-band polarized electron PWT injector operating under the parameters for the International Linear Collider is presented. The projected normalized transverse rms emittance is an order of magnitude lower than that produced with a polarized electron dc gun followed by subharmonic bunchers.

A method to calculate Stokes parameters and angle of polarization of skylight from polarized CIMEL sun/sky radiometers

International Nuclear Information System (INIS)

Li, L.; Li, Z.; Li, K.; Blarel, L.; Wendisch, M.

2014-01-01

The polarized CIMEL sun/sky radiometers have been routinely operated within the Sun/sky-radiometer Observation NETwork (SONET) in China and some sites of the AErosol RObotic NETwork (AERONET) around the world. However, the polarization measurements are not yet widely used due to in a certain degree the lack of Stokes parameters derived directly from these polarization measurements. Meanwhile, it have been shown that retrievals of several microphysical properties of aerosol particles can be significantly improved by using degree of linear polarization (DoLP) measurements of polarized CIMEL sun/sky radiometers (CE318-DP). The Stokes parameters Q and U, as well as angle of polarization (AoP) contain additional information about linear polarization and its orientation. A method to calculate Stokes parameters Q, U, and AoP from CE318-DP polarized skylight measurements is introduced in this study. A new polarized almucantar geometry based on CE318-DP is measured to illustrate abundant variation features of these parameters. The polarization parameters calculated in this study are consistent with previous results of DoLP and I, and also comparable to vector radiative transfer simulations. - Highlights: • The CE318-DP polarized measurements are not yet widely used except DoLP. • Compared with DoLP and I, difficulty in calculating Stokes Q and U is discussed. • A new polarized almucantar observation geometry based on CE318-DP is executed. • We derive Stokes Q, U, and AoP both in principal and almucantar plane geometries. • The results are comparable with previous DoLP and I, as well as model simulations

Ground-based Polarization Remote Sensing of Atmospheric Aerosols and the Correlation between Polarization Degree and PM2.5

International Nuclear Information System (INIS)

Cheng, Chen; Zhengqiang, Li; Weizhen, Hou; Yisong, Xie; Donghui, Li; Kaitao, Li; Ying, Zhang

2014-01-01

The ground-based polarization remote sensing adds the polarization dimension information to traditional intensity detection, which provides a new method to detect atmospheric aerosols properties. In this paper, the polarization measurements achieved by a new multi-wavelength sun photometer, CE318-DP, are used for the ground-based remote sensing of atmospheric aerosols. In addition, a polarized vector radiative transfer model is introduced to simulate the DOLP (Degree Of Linear Polarization) under different sky conditions. At last, the correlative analysis between mass density of PM 2.5 and multi-wavelength and multi-angular DOLP is carried out. The result shows that DOLP has a high correlation with mass density of PM 2.5 , R 2 >0.85. As a consequence, this work provides a new method to estimate the mass density of PM 2.5 by using the comprehensive network of ground-based sun photometer

Ghost instabilities of cosmological models with vector fields nonminimally coupled to the curvature

International Nuclear Information System (INIS)

Himmetoglu, Burak; Peloso, Marco; Contaldi, Carlo R.

2009-01-01

We prove that many cosmological models characterized by vectors nonminimally coupled to the curvature (such as the Turner-Widrow mechanism for the production of magnetic fields during inflation, and models of vector inflation or vector curvaton) contain ghosts. The ghosts are associated with the longitudinal vector polarization present in these models and are found from studying the sign of the eigenvalues of the kinetic matrix for the physical perturbations. Ghosts introduce two main problems: (1) they make the theories ill defined at the quantum level in the high energy/subhorizon regime (and create serious problems for finding a well-behaved UV completion), and (2) they create an instability already at the linearized level. This happens because the eigenvalue corresponding to the ghost crosses zero during the cosmological evolution. At this point the linearized equations for the perturbations become singular (we show that this happens for all the models mentioned above). We explicitly solve the equations in the simplest cases of a vector without a vacuum expectation value in a Friedmann-Robertson-Walker geometry, and of a vector with a vacuum expectation value plus a cosmological constant, and we show that indeed the solutions of the linearized equations diverge when these equations become singular.

Dynamics of bound vector solitons induced by stochastic perturbations: Soliton breakup and soliton switching

International Nuclear Information System (INIS)

Sun, Zhi-Yuan; Gao, Yi-Tian; Yu, Xin; Liu, Ying

2013-01-01

We respectively investigate breakup and switching of the Manakov-typed bound vector solitons (BVSs) induced by two types of stochastic perturbations: the homogenous and nonhomogenous. Symmetry-recovering is discovered for the asymmetrical homogenous case, while soliton switching is found to relate with the perturbation amplitude and soliton coherence. Simulations show that soliton switching in the circularly-polarized light system is much weaker than that in the Manakov and linearly-polarized systems. In addition, the homogenous perturbations can enhance the soliton switching in both of the Manakov and non-integrable (linearly- and circularly-polarized) systems. Our results might be helpful in interpreting dynamics of the BVSs with stochastic noises in nonlinear optics or with stochastic quantum fluctuations in Bose–Einstein condensates.

The charge form factor of the neutron from sup 2 H-vector, (e-vector, e' n)p

CERN Document Server

Passchier, I; Szczerba, D; Alarcon, R; Bauer, T S; Boersma, D J; Van der Brand, J F J; Bulten, H J; Ferro-Luzzi, M; Higinbotham, D W; Jager, C W D; Klous, S; Kolster, H; Lang, J; Nikolenko, D M; Nooren, G J; Norum, B E; Poolman, H R; Rachek, Igor A; Simani, M C; Six, E; Vries, H D; Wang, K; Zhou, Z L

2000-01-01

We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A sup V sub e sub d was measured for the reaction sup 2 H-vector, (e-vector, e'n)p at a four-momentum transfer squared of 0.21 (GeV/c) sup 2 from which a value for the charge form factor of the neutron was extracted.

The copepod Calanus spp. (Calanidae) is repelled by polarized light

Science.gov (United States)

Lerner, Amit; Browman, Howard I.

2016-10-01

Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addition, the transparency of these copepods, as they might be seen by polarization insensitive vs. sensitive visual systems, was measured. Calanus spp. exhibited negative polarotaxis with a preference ratio of 1.9:1. Their transparency decreased from 80% to 20% to 30% in the unpolarized, partially polarized, and electric (e-) vector orientation domains respectively - that is, these copepods would appear opaque and conspicuous to a polarization-sensitive viewer looking at them under conditions rich in polarized light. Since the only difference between the two plankton traps was the polarization cue, we conclude that Calanus spp. are polarization sensitive and exhibit negative polarotaxis at low light intensities (albeit well within the sensitivity range reported for copepods). We hypothesize that Calanus spp. can use polarization vision to reduce their risk of predation by polarization-sensitive predators and suggest that this be tested in future experiments.

A scalar-vector model of quark-antiquark interaction under linear confinement

International Nuclear Information System (INIS)

Chakrabarty, S.

1992-08-01

Considering the idea that the constituent quark mass is the dressed sum of current quark mass and dynamical quark mass, and using the standard values of current quark masses we obtain approximate values of constituent quark masses, which are then used in our extensively studied Bethe-Salpeter-reduced potential model. We find that the mass formulas become much simpler for linear potential ar with zero anomalous magnetic moment (λ), the values of scalar-vector fraction (η) and 'a' in the linear potential being (1/4) and (1/5) respectively. Also, some of the quantities can be related to each other and the match with experimental data is good. (author). 18 refs, 3 tabs

Stable Single Polarization, Single Frequency, and Linear Cavity Er-Doped Fiber Laser Using a Saturable Absorber

International Nuclear Information System (INIS)

Li Qi; Yan Feng-Ping; Peng Wan-Jing; Feng Su-Chun; Feng Ting; Tan Si-Yu; Liu Peng

2013-01-01

A simple approach for stable single polarization, single frequency, and linear cavity erbium doped fiber laser is proposed and demonstrated. A Fabry—Pérot filter, polarizer and saturable absorber are used together to ensure stable single frequency, single polarization operation. The optical signal-to-noise ratio of the laser is approximately 57 dB, and the Lorentz linewidth is 13.9 kHz. The polarization state of the laser with good stability is confirmed and the degree of polarization is >99%

Genetic modification of adeno-associated viral vector type 2 capsid enhances gene transfer efficiency in polarized human airway epithelial cells.

Science.gov (United States)

White, April F; Mazur, Marina; Sorscher, Eric J; Zinn, Kurt R; Ponnazhagan, Selvarangan

2008-12-01

Cystic fibrosis (CF) is a common genetic disease characterized by defects in the expression of the CF transmembrane conductance regulator (CFTR) gene. Gene therapy offers better hope for the treatment of CF. Adeno-associated viral (AAV) vectors are capable of stable expression with low immunogenicity. Despite their potential in CF gene therapy, gene transfer efficiency by AAV is limited because of pathophysiological barriers in these patients. Although a few AAV serotypes have shown better transduction compared with the AAV2-based vectors, gene transfer efficiency in human airway epithelium has still not reached therapeutic levels. To engineer better AAV vectors for enhanced gene delivery in human airway epithelium, we developed and characterized mutant AAV vectors by genetic capsid modification, modeling the well-characterized AAV2 serotype. We genetically incorporated putative high-affinity peptide ligands to human airway epithelium on the GH loop region of AAV2 capsid protein. Six independent mutant AAV were constructed, containing peptide ligands previously reported to bind with high affinity for known and unknown receptors on human airway epithelial cells. The vectors were tested on nonairway cells and nonpolarized and polarized human airway epithelial cells for enhanced infectivity. One of the mutant vectors, with the peptide sequence THALWHT, not only showed the highest transduction in undifferentiated human airway epithelial cells but also indicated significant transduction in polarized cells. Interestingly, this modified vector was also able to infect cells independently of the heparan sulfate proteoglycan receptor. Incorporation of this ligand on other AAV serotypes, which have shown improved gene transfer efficiency in the human airway epithelium, may enhance the application of AAV vectors in CF gene therapy.

Joint polarization tracking and channel equalization based on radius-directed linear Kalman filter

Science.gov (United States)

Zhang, Qun; Yang, Yanfu; Zhong, Kangping; Liu, Jie; Wu, Xiong; Yao, Yong

2018-01-01

We propose a joint polarization tracking and channel equalization scheme based on radius-directed linear Kalman filter (RD-LKF) by introducing the butterfly finite-impulse-response (FIR) filter in our previously proposed RD-LKF method. Along with the fast polarization tracking, it can also simultaneously compensate the inter-symbol interference (ISI) effects including residual chromatic dispersion and polarization mode dispersion. Compared with the conventional radius-directed equalizer (RDE) algorithm, it is demonstrated experimentally that three times faster convergence speed, one order of magnitude better tracking capability, and better BER performance is obtained in polarization division multiplexing 16 quadrature amplitude modulation system. Besides, the influences of the algorithm parameters on the convergence and the tracking performance are investigated by numerical simulation.

Polarization holograms in a bifunctional amorphous polymer exhibiting equal values of photoinduced linear and circular birefringences.

Science.gov (United States)

Provenzano, Clementina; Pagliusi, Pasquale; Cipparrone, Gabriella; Royes, Jorge; Piñol, Milagros; Oriol, Luis

2014-10-09

Light-controlled molecular alignment is a flexible and useful strategy introducing novelty in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics and addressing the development of smart optical devices. Azobenzene-containing polymers are well-known photocontrollable materials with large and reversible photoinduced optical anisotropies. The vectorial holography applied to these materials enables peculiar optical devices whose properties strongly depend on the relative values of the photoinduced birefringences. Here is reported a polarization holographic recording based on the interference of two waves with orthogonal linear polarization on a bifunctional amorphous polymer that, exceptionally, exhibits equal values of linear and circular birefringence. The peculiar photoresponse of the material coupled with the holographic technique demonstrates an optical device capable of decomposing the light into a set of orthogonally polarized linear components. The holographic structures are theoretically described by the Jones matrices method and experimentally investigated.

Optically-driven red blood cell rotor in linearly polarized laser tweezers

Indian Academy of Sciences (India)

We have constructed a dual trap optical tweezers set-up around an inverted microscope where both the traps can be independently controlled and manipulated in all the three dimensions. Here we report our observations on rotation of red blood cells (RBCs) in a linearly polarized optical trap. Red blood cells deform and ...

Photoelectron linear accelerator for producing a low emittance polarized electron beam

Science.gov (United States)

Yu, David U.; Clendenin, James E.; Kirby, Robert E.

2004-06-01

A photoelectron linear accelerator for producing a low emittance polarized electric beam. The accelerator includes a tube having an inner wall, the inner tube wall being coated by a getter material. A portable, or demountable, cathode plug is mounted within said tube, the surface of said cathode having a semiconductor material formed thereon.

Groups, matrices, and vector spaces a group theoretic approach to linear algebra

CERN Document Server

Carrell, James B

2017-01-01

This unique text provides a geometric approach to group theory and linear algebra, bringing to light the interesting ways in which these subjects interact. Requiring few prerequisites beyond understanding the notion of a proof, the text aims to give students a strong foundation in both geometry and algebra. Starting with preliminaries (relations, elementary combinatorics, and induction), the book then proceeds to the core topics: the elements of the theory of groups and fields (Lagrange's Theorem, cosets, the complex numbers and the prime fields), matrix theory and matrix groups, determinants, vector spaces, linear mappings, eigentheory and diagonalization, Jordan decomposition and normal form, normal matrices, and quadratic forms. The final two chapters consist of a more intensive look at group theory, emphasizing orbit stabilizer methods, and an introduction to linear algebraic groups, which enriches the notion of a matrix group. Applications involving symm etry groups, determinants, linear coding theory ...

Relations between broad-band linear polarization and Ca II H and K emission in late-type dwarf stars

Science.gov (United States)

Huovelin, Juhani; Saar, Steven H.; Tuominen, Ilkka

1988-01-01

Broadband UBV linear polarization data acquired for a sample of late-type dwarfs are compared with contemporaneous measurements of Ca II H and K line core emission. A weighted average of the largest values of the polarization degree is shown to be the best parameter for chromospheric activity diagnosis. The average maximum polarization in the UV is found to increase from late-F to late-G stars. It is noted that polarization in the U band is considerably more sensitive to activity variations than that in the B or V bands. The results indicate that stellar magnetic fields and the resulting saturation in the Zeeman-sensitive absorption lines are the most probably source of linear polarization in late-type main-sequence stars.

Polarization observables measured in the reaction vector pp → pK{sup +}Λ by COSY-TOF

Energy Technology Data Exchange (ETDEWEB)

Hauenstein, Florian [Forschungszentrum Juelich, Juelich (Germany); Collaboration: COSY-TOF-Collaboration

2016-07-01

The vector pp → pK{sup +}Λ reaction was measured with the COSY-TOF detector using a polarized proton beam with beam momenta 2.7 GeV/c and 2.95 GeV/c. The measurements with a polarized beam allow the determination of polarization observables in addition to the differential cross sections. These observables are the Λ polarization, the spin transfer to the Λ and the analyzing power of the final state particles. The latter is connected with the partial wave composition of the final state system, while the first two can improve the understanding of the underlying reaction mechanism of the associated strangeness production. Currently, no sophisticated models exist in this energy regime, thus, conclusive results concerning the reaction mechanism can not be drawn yet. Nevertheless, the obtained data are the first with full phase space acceptance and high statistics in this beam energy regime. In this talk the extraction methods for the different polarization observables are explained, and results for the polarization observables as a function of different variables are shown. The dependencies of the results on the beam momentum are discussed. Furthermore, a comparison with theoretical expectations from high energy physics for the Λ polarization is given.

Double vector meson production in the International Linear Collider

Energy Technology Data Exchange (ETDEWEB)

Carvalho, F. [Universidade Federal de Sao Paulo, Departamento de Ciencias Exatas e da Terra, Diadema, SP (Brazil); Goncalves, V.P. [Universidade Federal de Pelotas, High and Medium Energy Group, Instituto de Fisica e Matematica, Caixa Postal 354, Pelotas, RS (Brazil); Moreira, B.D.; Navarra, F.S. [Universidade de Sao Paulo, Instituto de Fisica, C.P. 66318, Sao Paulo, SP (Brazil)

2015-08-15

In this paper we study double vector meson production in γγ interactions at high energies and estimate, using the color dipole picture, the main observables which can be probed at the International Linear Collider (ILC). The total γ(Q{sub 1}{sup 2}) + γ(Q{sub 2}{sup 2}) → V{sub 1} + V{sub 2} cross sections for V{sub i} = ρ, J/ψ, and Υ are computed and the energy and virtuality dependencies are studied in detail. Our results demonstrate that the experimental analysis of this process is feasible at the ILC and it can be useful to constrain the QCD dynamics at high energies. (orig.)

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

Directory of Open Access Journals (Sweden)

Wang Tong

2017-07-01

Full Text Available 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.

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.

2017-07-01

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.

Linear and non-linear optics of condensed matter

International Nuclear Information System (INIS)

McLean, T.P.

1977-01-01

Part I - Linear optics: 1. General introduction. 2. Frequency dependence of epsilon(ω, k vector). 3. Wave-vector dependence of epsilon(ω, k vector). 4. Tensor character of epsilon(ω, k vector). Part II - Non-linear optics: 5. Introduction. 6. A classical theory of non-linear response in one dimension. 7. The generalization to three dimensions. 8. General properties of the polarizability tensors. 9. The phase-matching condition. 10. Propagation in a non-linear dielectric. 11. Second harmonic generation. 12. Coupling of three waves. 13. Materials and their non-linearities. 14. Processes involving energy exchange with the medium. 15. Two-photon absorption. 16. Stimulated Raman effect. 17. Electro-optic effects. 18. Limitations of the approach presented here. (author)

A dual-optically-pumped polarized negative deuterium ion source

International Nuclear Information System (INIS)

Kinsho, M.; Mori, Y.; Ikegami, K.; Takagi, A.

1994-01-01

An optically pumped polarized H - source (OPPIS), which is based on the charge exchange between H + ions and electron-spin-polarized alkali atoms has been developed at KEK. Just by applying this scheme to a deuteron beam, it is difficult to obtain a highly vector polarized deuteron beam. To obtain highly vector polarized D - ions, we have developed a 'dual optical pumping type' of polarized D - source. With this scheme, a 100% vector nuclear-spin polarization for D - ions is possible in principle. In a preliminary experiment, a 60% of vector nuclear-spin polarized D - ions was obtained. (author)

Finite-dimensional linear algebra

CERN Document Server

Gockenbach, Mark S

2010-01-01

Some Problems Posed on Vector SpacesLinear equationsBest approximationDiagonalizationSummaryFields and Vector SpacesFields Vector spaces Subspaces Linear combinations and spanning sets Linear independence Basis and dimension Properties of bases Polynomial interpolation and the Lagrange basis Continuous piecewise polynomial functionsLinear OperatorsLinear operatorsMore properties of linear operatorsIsomorphic vector spaces Linear operator equations Existence and uniqueness of solutions The fundamental theorem; inverse operatorsGaussian elimination Newton's method Linear ordinary differential eq

Total elimination of sampling errors in polarization imagery obtained with integrated microgrid polarimeters.

Science.gov (United States)

Tyo, J Scott; LaCasse, Charles F; Ratliff, Bradley M

2009-10-15

Microgrid polarimeters operate by integrating a focal plane array with an array of micropolarizers. The Stokes parameters are estimated by comparing polarization measurements from pixels in a neighborhood around the point of interest. The main drawback is that the measurements used to estimate the Stokes vector are made at different locations, leading to a false polarization signature owing to instantaneous field-of-view (IFOV) errors. We demonstrate for the first time, to our knowledge, that spatially band limited polarization images can be ideally reconstructed with no IFOV error by using a linear system framework.

Dual linear structured support vector machine tracking method via scale correlation filter

Science.gov (United States)

Li, Weisheng; Chen, Yanquan; Xiao, Bin; Feng, Chen

2018-01-01

Adaptive tracking-by-detection methods based on structured support vector machine (SVM) performed well on recent visual tracking benchmarks. However, these methods did not adopt an effective strategy of object scale estimation, which limits the overall tracking performance. We present a tracking method based on a dual linear structured support vector machine (DLSSVM) with a discriminative scale correlation filter. The collaborative tracker comprised of a DLSSVM model and a scale correlation filter obtains good results in tracking target position and scale estimation. The fast Fourier transform is applied for detection. Extensive experiments show that our tracking approach outperforms many popular top-ranking trackers. On a benchmark including 100 challenging video sequences, the average precision of the proposed method is 82.8%.

MAPPING THE LINEARLY POLARIZED SPECTRAL LINE EMISSION AROUND THE EVOLVED STAR IRC+10216

Energy Technology Data Exchange (ETDEWEB)

Girart, J. M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, 08193 Bellaterra, Catalunya (Spain); Patel, N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Vlemmings, W. H. T. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Rao, Ramprasad, E-mail: girart@ice.cat [Submillimeter Array, Academia Sinica Institute of Astronomy and Astrophysics, 645 N. Aohoku Place, Hilo, HI 96720 (United States)

2012-05-20

We present spectro-polarimetric observations of several molecular lines obtained with the Submillimeter Array toward the carbon-rich asymptotic giant branch star IRC+10216. We have detected and mapped the linear polarization of the CO 3-2, SiS 19-18, and CS 7-6 lines. The polarization arises at a distance of {approx_equal} 450 AU from the star and is blueshifted with respect to the Stokes I. The SiS 19-18 polarization pattern appears to be consistent with a locally radial magnetic field configuration. However, the CO 3-2 and CS 7-6 line polarization suggests an overall complex magnetic field morphology within the envelope. This work demonstrates the feasibility of using spectro-polarimetric observations to carry out tomographic imaging of the magnetic field in circumstellar envelopes.

A Novel Attitude Determination System Aided by Polarization Sensor

Directory of Open Access Journals (Sweden)

Wei Zhi

2018-01-01

Full Text Available This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle.

A Novel Attitude Determination System Aided by Polarization Sensor.

Science.gov (United States)

Zhi, Wei; Chu, Jinkui; Li, Jinshan; Wang, Yinlong

2018-01-09

This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF) with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV) flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle.

Blazed vector grating liquid crystal cells with photocrosslinkable polymeric alignment films fabricated by one-step polarizer rotation method

Science.gov (United States)

Kawai, Kotaro; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

2014-12-01

Blazed vector grating liquid crystal (LC) cells, in which the directors of low-molar-mass LCs are antisymmetrically distributed, were fabricated by one-step exposure of an empty glass cell inner-coated with a photocrosslinkable polymer LC (PCLC) to UV light. By adopting a LC cell structure, twisted nematic (TN) and homogeneous (HOMO) alignments were obtained in the blazed vector grating LC cells. Moreover, the diffraction efficiency of the blazed vector grating LC cells was greatly improved by increasing the thickness of the device in comparison with that of a blazed vector grating with a thin film structure obtained in our previous study. In addition, the diffraction efficiency and polarization states of ±1st-order diffracted beams from the resultant blazed vector grating LC cells were controlled by designing a blazed pattern in the alignment films, and these diffraction properties were well explained on the basis of Jones calculus and the elastic continuum theory of nematic LCs.

Topological events on the lines of circular polarization in nonparaxial vector optical fields.

Science.gov (United States)

Freund, Isaac

2017-02-01

In nonparaxial vector optical fields, the following topological events are shown to occur in apparent violation of charge conservation: as one translates the observation plane along a line of circular polarization (a C line), the points on the line (C points) are seen to change not only the signs of their topological charges, but also their handedness, and, at turning points on the line, paired C points with the same topological charge and opposite handedness are seen to nucleate. These counter-intuitive events cannot occur in paraxial fields.

Generation of circular polarization of the cosmic microwave background

International Nuclear Information System (INIS)

Alexander, Stephon; Ochoa, Joseph; Kosowsky, Arthur

2009-01-01

The standard cosmological model, which includes only Compton scattering photon interactions at energy scales near recombination, results in zero primordial circular polarization of the cosmic microwave background. In this paper we consider a particular renormalizable and gauge-invariant standard model extension coupling photons to an external vector field via a Chern-Simons term, which arises as a radiative correction if gravitational torsion couples to fermions. We compute the transport equations for polarized photons from a Boltzmann-like equation, showing that such a coupling will source circular polarization of the microwave background. For the particular coupling considered here, the circular polarization effect is always negligible compared to the rotation of the linear polarization orientation, also derived using the same formalism. We note the possibility that limits on microwave background circular polarization may probe other photon interactions and related fundamental effects such as violations of Lorentz invariance.

Spin exchange in polarized deuterium

International Nuclear Information System (INIS)

Przewoski, B. von; Meyer, H.O.; Balewski, J.; Doskow, J.; Ibald, R.; Pollock, R.E.; Rinckel, T.; Wellinghausen, A.; Whitaker, T.J.; Daehnick, W.W.; Haeberli, W.; Schwartz, B.; Wise, T.; Lorentz, B.; Rathmann, F.; Pancella, P.V.; Saha, Swapan K.; Thoerngren-Engblom, P.

2003-01-01

We have measured the vector and tensor polarization of an atomic deuterium target as a function of the target density. The polarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam source was operated without rf transitions, in order to avoid complications from the unknown efficiency of these transitions. In this mode, the atomic beam is vector and tensor polarized and both polarizations can be measured simultaneously. We used a 1.2-cm-diam and 27-cm-long storage cell, which yielded an average target density between 3 and 9x10 11 at/cm 3 . We find that the tensor polarization decreases with increasing target density while the vector polarization remains constant. The data are in quantitative agreement with the calculated effect of spin exchange between deuterium atoms at low field

Vector-Tensor and Vector-Vector Decay Amplitude Analysis of B0→φK*0

International Nuclear Information System (INIS)

Aubert, B.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.

2007-01-01

We perform an amplitude analysis of the decays B 0 →φK 2 * (1430) 0 , φK * (892) 0 , and φ(Kπ) S-wave 0 with a sample of about 384x10 6 BB pairs recorded with the BABAR detector. The fractions of longitudinal polarization f L of the vector-tensor and vector-vector decay modes are measured to be 0.853 -0.069 +0.061 ±0.036 and 0.506±0.040±0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP violation

Source finding in linear polarization for LOFAR, and SKA predecessor surveys, using Faraday moments

Science.gov (United States)

Farnes, J. S.; Heald, G.; Junklewitz, H.; Mulcahy, D. D.; Haverkorn, M.; Van Eck, C. L.; Riseley, C. J.; Brentjens, M.; Horellou, C.; Vacca, V.; Jones, D. I.; Horneffer, A.; Paladino, R.

2018-03-01

The optimal source-finding strategy for linear polarization data is an unsolved problem, with many inhibitive factors imposed by the technically challenging nature of polarization observations. Such an algorithm is essential for Square Kilometre Array (SKA) pathfinder surveys, such as the Multifrequency Snapshot Sky Survey with the LOw Frequency ARray (LOFAR), as data volumes are significant enough to prohibit manual inspection. We present a new strategy of `Faraday Moments' for source-finding in linear polarization with LOFAR, using the moments of the frequency-dependent full-Stokes data (i.e. the mean, standard deviation, skewness, and excess kurtosis). Through simulations of the sky, we find that moments can identify polarized sources with a high completeness: 98.5 per cent at a signal to noise of 5. While the method has low reliability, rotation measure (RM) synthesis can be applied per candidate source to filter out instrumental and spurious detections. This combined strategy will result in a complete and reliable catalogue of polarized sources that includes the full sensitivity of the observational bandwidth. We find that the technique can reduce the number of pixels on which RM Synthesis needs to be performed by a factor of ≈1 × 105 for source distributions anticipated with modern radio telescopes. Through tests on LOFAR data, we find that the technique works effectively in the presence of diffuse emission. Extensions of this method are directly applicable to other upcoming radio surveys such as the POlarization Sky Survey of the Universe's Magnetism with the Australia Square Kilometre Array Pathfinder, and the SKA itself.

Mitigating of modal instabilities in linearly-polarized fiber amplifiers by shifting pump wavelength

International Nuclear Information System (INIS)

Tao, Rumao; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

2015-01-01

We investigated the effect of pump wavelength on the modal instabilities (MI) in high-power linearly polarized Yb-doped fiber amplifiers. We built a novel semi-analytical model to determine the frequency coupling characteristics and power threshold of MI, which indicates promising MI suppression through pumping at an appropriate wavelength. By pumping at 915 nm, the threshold can be enhanced by a factor of 2.1 as compared to that pumped at 976 nm. Based on a high-power linearly polarized fiber amplifier platform, we studied the influence of pump wavelength experimentally. A maximal enhancement factor of 1.9 has been achieved when pumped at 915 nm, which agrees with the theoretical calculation and verified our theoretical model. Furthermore, we show that MI suppression by detuning the pump wavelength is weakened for fiber with a large core-to-cladding ratio. (paper)

Three-dimensional polarization states of monochromatic light fields.

Science.gov (United States)

Azzam, R M A

2011-11-01

The 3×1 generalized Jones vectors (GJVs) [E(x) E(y) E(z)](t) (t indicates the transpose) that describe the linear, circular, and elliptical polarization states of an arbitrary three-dimensional (3-D) monochromatic light field are determined in terms of the geometrical parameters of the 3-D vibration of the time-harmonic electric field. In three dimensions, there are as many distinct linear polarization states as there are points on the surface of a hemisphere, and the number of distinct 3-D circular polarization states equals that of all two-dimensional (2-D) polarization states on the Poincaré sphere, of which only two are circular states. The subset of 3-D polarization states that results from the superposition of three mutually orthogonal x, y, and z field components of equal amplitude is considered as a function of their relative phases. Interesting contours of equal ellipticity and equal inclination of the normal to the polarization ellipse with respect to the x axis are obtained in 2-D phase space. Finally, the 3×3 generalized Jones calculus, in which elastic scattering (e.g., by a nano-object in the near field) is characterized by the 3-D linear transformation E(s)=T E(i), is briefly introduced. In such a matrix transformation, E(i) and E(s) are the 3×1 GJVs of the incident and scattered waves and T is the 3×3 generalized Jones matrix of the scatterer at a given frequency and for given directions of incidence and scattering.

Quasi-stability of a vector trajectorial problem with non-linear partial criteria

Directory of Open Access Journals (Sweden)

Vladimir A. Emelichev

2003-10-01

Full Text Available Multi-objective (vector combinatorial problem of finding the Pareto set with four kinds of non-linear partial criteria is considered. Necessary and sufficient conditions of that kind of stability of the problem (quasi-stability are obtained. The problem is a discrete analogue of the lower semicontinuity by Hausdorff of the optimal mapping. Mathematics Subject Classification 2000: 90C10, 90C05, 90C29, 90C31.

Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

International Nuclear Information System (INIS)

Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

2010-01-01

We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

Measurement of K/sub NN/, K/sub LL/ in p vector d → n vector X and p vector 9Be → n vector X at 800 MeV

International Nuclear Information System (INIS)

Riley, P.J.; Hollas, C.L.; Newsom, C.R.

1980-01-01

The spin transfer parameters, K/sub NN/ and K/sub LL/, have been measured in p vector d → n vector X and p vector 9 Be → n vector X at 0 0 and 800 MeV. The rather large values of K/sub LL/ demonstrate that this transfer mechanism will provide a useful source of polarized neutrons at LAMPF energies

Polarized atomic orbitals for linear scaling methods

Science.gov (United States)

Berghold, Gerd; Parrinello, Michele; Hutter, Jürg

2002-02-01

We present a modified version of the polarized atomic orbital (PAO) method [M. S. Lee and M. Head-Gordon, J. Chem. Phys. 107, 9085 (1997)] to construct minimal basis sets optimized in the molecular environment. The minimal basis set derives its flexibility from the fact that it is formed as a linear combination of a larger set of atomic orbitals. This approach significantly reduces the number of independent variables to be determined during a calculation, while retaining most of the essential chemistry resulting from the admixture of higher angular momentum functions. Furthermore, we combine the PAO method with linear scaling algorithms. We use the Chebyshev polynomial expansion method, the conjugate gradient density matrix search, and the canonical purification of the density matrix. The combined scheme overcomes one of the major drawbacks of standard approaches for large nonorthogonal basis sets, namely numerical instabilities resulting from ill-conditioned overlap matrices. We find that the condition number of the PAO overlap matrix is independent from the condition number of the underlying extended basis set, and consequently no numerical instabilities are encountered. Various applications are shown to confirm this conclusion and to compare the performance of the PAO method with extended basis-set calculations.

Linear polarization measurements at H. beta. of early-type emission line stars

Energy Technology Data Exchange (ETDEWEB)

Clarke, D; McLean, I S [Glasgow Univ. (UK)

1976-02-01

Linear polarization measurements across the H..beta.. emission lines of the stars ..gamma.. Cas, zeta Tau and 48 Per are presented. For the first two stars there is a marked reduction of the polarization at the centre of the line and for ..gamma.. Cas, this varies from night to night. During the H..beta.. observations of zeta Tau, a change of polarization over tens of minutes was indicated in a monitor channel tuned to the continuum on the blue side of H..beta... For the fainter star, 48 Per, the uncertainties of the polarimetry were increased in relation to ..gamma.. Cas and zeta Tau by a factor of about two and at this precision, no differential effects across the line were recorded. Observations of ..cap alpha.. Cyg are also given to demonstrate the reliability of the polarimeter.

The high peak current polarized electron source of the Stanford Linear Collider

International Nuclear Information System (INIS)

Schultz, D.; Alley, R.; Aoyagi, H.; Clendenin, J.; Frisch, J.; Garden, C.; Hoyt, E.; Kirby, R.; Klaisner, L.; Kulikov, A.; Mulhollan, G.; Prescott, C.; Saez, P.; Tang, H.; Turner, J.; Woods, M.; Yeremian, D.; Zolotorev, M.

1994-01-01

The Stanford Linear Collider injector requires two 2 ns pulses of 4.5-5.5 x 10 10 electrons, separated by 61 ns at 120 Hz, from its source. Since 1992, these currents have been provided by a polarized electron source based on GaAs photocathodes. A beam polarization of 76±4% has been measured at the end of the 50 GeV linac. At low photocathode quantum efficiencies, and for excitation near threshold, the maximum current delivered by the source is constrained, not by the space charge limit of the gun, but by a ''charge limit'' of the photocathode. The charge limited current is proportional to the photocathode quantum efficiency, but the proportionality varies for different photocathode types. Experience with high polarization strained GaAs photocathodes on a test beamline and on the SLC is presented. (orig.)

Vector vortex beam generation with dolphin-shaped cell meta-surface.

Science.gov (United States)

Yang, Zhuo; Kuang, Deng-Feng; Cheng, Fang

2017-09-18

We present a dolphin-shaped cell meta-surface, which is a combination of dolphin-shaped metallic cells and dielectric substrate, for vector vortex beam generation with the illumination of linearly polarized light. Surface plasmon polaritons are excited at the boundary of the metallic cells, then guided by the metallic structures, and finally squeezed to the tips to form highly localized strong electromagnetic fields, which generate the intensity of vector vortex beams at z component. Synchronously, the abrupt phase change produced by the meta-surface is utilized to explain the vortex phase generated by elements. The new kind of structure can be utilized for communication, bioscience, and materiality.

Application of spin-polarized fuel to fusion reactions

International Nuclear Information System (INIS)

Wakuta, Y.; Nakao, Y.; Honda, T.; Honda, Y.; Nakashima, H.

1990-01-01

Studies on the application of the polarized fuel to the inertial fusion reaction have been carried out. It is shown that the use of the spin-polarized fuel D vector·T vector or D vector· 3 (He)vector reduces the irradiating laser power more than 50% compared with the use of the unpolarized fuel. The depolarization rate of the polarized fuel during the fusing process is found to be almost negligible. (author)

Multiply charged negative ions of hydrogen in linearly polarized laser fields

International Nuclear Information System (INIS)

van Duijn, E.; Muller, H.G.

1997-01-01

Motivated by the prediction of the appearance of atomic multiply charged negative ions (AMCNI) of hydrogen, induced by a linearly polarized laser field, we present an analytical quantum mechanical treatment of the appearance and structure of AMCNI in a linearly polarized field, based on high-frequency Floquet theory (HFFT). For the simplest AMCNI of hydrogen, H 2- and H 3- , the values of α 0 at which the first bound state appears are α 0 =1.62x10 2 and α 0 =1.02x10 4 , where α 0 =I 1/2 /ω 2 is the amplitude of the oscillation of a free electron in the field with frequency ω and intensity I (unless stated otherwise, we use atomic units throughout this paper). Whereas in vacuum at least one of the electrons of an AMCNI autodetaches, an intense high-frequency field can change the character of the ion dramatically, such that bound states of AMCNI can appear. Due to the interaction with the field, the electrons of the AMCNI oscillate in phase along the polarization axis. This open-quotes quiverclose quotes motion enables the electrons to be spatially separated over distances of order α 0 , reducing the repulsive e-e interaction as α 0 increases. In other words, for α 0 large enough, the field enables a configuration in which the electrons, while widely separated, are bound to one proton. For the prediction of bound states of H N- with N>3, however, a relativistic description or low-frequency theory is required. copyright 1997 The American Physical Society

Circularly polarized light to study linear magneto-optics for ferrofluids: θ-scan technique

Science.gov (United States)

Meng, Xiangshen; Huang, Yan; He, Zhenghong; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Li, Jian; Qiu, Xiaoyan

2018-06-01

Circularly polarized light can be divided into two vertically linearly polarized light beams with  ±π/2 phase differences. In the presence of an external magnetic field, when circularly polarized light travels through a ferrofluid film, whose thickness is no more than that of λ/4 plate, magneto-optical, magnetic birefringence and dichroism effects cause the transmitted light to behave as elliptically polarized light. Using angular scan by a continuously rotating polarizer as analyzer, the angular (θ) distribution curve of relative intensity (T) corresponding to elliptically polarized light can be measured. From the T  ‑  θ curve having ellipsometry, the parameters such as the ratio of short to long axis, and angular orientation of the long axis to the vertical field direction can be obtained. Thus, magnetic birefringence and dichroism can be probed simultaneously by measuring magneto-optical, positive or negative birefringence and dichroism features from the transmission mode. The proposed method is called θ-scan technique, and can accurately determine sample stability, magnetic field direction, and cancel intrinsic light source ellipticity. This study may be helpful to further research done to ferrofluids and other similar colloidal samples with anisotropic optics.

OBSERVATIONS OF LINEAR POLARIZATION IN A SOLAR CORONAL LOOP PROMINENCE SYSTEM OBSERVED NEAR 6173 Å

Energy Technology Data Exchange (ETDEWEB)

Saint-Hilaire, Pascal; Martínez Oliveros, Juan-Carlos; Hudson, Hugh S.; Krucker, Säm; Bain, Hazel [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Schou, Jesper [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Couvidat, Sébastien, E-mail: shilaire@ssl.berkeley.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2014-05-10

White-light observations by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager of a loop-prominence system occurring in the aftermath of an X-class flare on 2013 May 13 near the eastern solar limb show a linearly polarized component, reaching up to ∼20% at an altitude of ∼33 Mm, about the maximum amount expected if the emission were due solely to Thomson scattering of photospheric light by the coronal material. The mass associated with the polarized component was 8.2 × 10{sup 14} g. At 15 Mm altitude, the brightest part of the loop was 3(±0.5)% linearly polarized, only about 20% of that expected from pure Thomson scattering, indicating the presence of an additional unpolarized component at wavelengths near Fe I (617.33 nm). We estimate the free electron density of the white-light loop system to possibly be as high as 1.8 × 10{sup 12} cm{sup –3}.

Statistical mechanical analysis of the linear vector channel in digital communication

International Nuclear Information System (INIS)

Takeda, Koujin; Hatabu, Atsushi; Kabashima, Yoshiyuki

2007-01-01

A statistical mechanical framework to analyze linear vector channel models in digital wireless communication is proposed for a large system. The framework is a generalization of that proposed for code-division multiple-access systems in Takeda et al (2006 Europhys. Lett. 76 1193) and enables the analysis of the system in which the elements of the channel transfer matrix are statistically correlated with each other. The significance of the proposed scheme is demonstrated by assessing the performance of an existing model of multi-input multi-output communication systems

Unique heavy lepton signature at e+e- linear collider with polarized beams

International Nuclear Information System (INIS)

Moortgat-Pick, G.; Osland, P.; Pankov, A.A.; Tsytrinov, A.V.

2013-03-01

We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e + e - →W + W - within E 6 models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton exchange from Z-Z' mixing within the same class of models and also from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to very similar experimental signatures at the e + e - International Linear Collider (ILC) for √(s)=350, 500 GeV and 1 TeV. Such clear identification of the model is possible by using a certain double polarization asymmetry. The availability of both beams being polarized plays a crucial role in identifying such exotic-lepton admixture. In addition, the sensitivity of the ILC for probing exotic-lepton admixture is substantially enhanced when the polarization of the produced W ± bosons is considered.

Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

DEFF Research Database (Denmark)

Liu, Xiang; Hu, Hao; Chandrasekhar, S.

2014-01-01

We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all...

Orthogonal linear polarization tunable-beat ring laser with a superluminescent diode

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Y.; Yoshino, T. [Department of Electronic Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376 (Japan)

1997-09-01

An orthogonal linear polarization operated ring laser with a superluminescent diode has been demonstrated to generate a tunable optical beat signal. The ring cavity contains a superluminescent diode as the optical gain medium, Faraday rotators, and a variable phase retarder (Babinet-Soleil compensator). By controlling the retarder, we changed the beat frequency in the range from a few tens of megahertz to 100 MHz. {copyright} 1997 Optical Society of America

Solution of single linear tridiagonal systems and vectorization of the ICCG algorithm on the Cray 1

International Nuclear Information System (INIS)

Kershaw, D.S.

1981-01-01

The numerical algorithms used to solve the physics equation in codes which model laser fusion are examined, it is found that a large number of subroutines require the solution of tridiagonal linear systems of equations. One dimensional radiation transport, thermal and suprathermal electron transport, ion thermal conduction, charged particle and neutron transport, all require the solution of tridiagonal systems of equations. The standard algorithm that has been used in the past on CDC 7600's will not vectorize and so cannot take advantage of the large speed increases possible on the Cray-1 through vectorization. There is however, an alternate algorithm for solving tridiagonal systems, called cyclic reduction, which allows for vectorization, and which is optimal for the Cray-1. Software based on this algorithm is now being used in LASNEX to solve tridiagonal linear systems in the subroutines mentioned above. The new algorithm runs as much as five times faster than the standard algorithm on the Cray-1. The ICCG method is being used to solve the diffusion equation with a nine-point coupling scheme on the CDC 7600. In going from the CDC 7600 to the Cray-1, a large part of the algorithm consists of solving tridiagonal linear systems on each L line of the Lagrangian mesh in a manner which is not vectorizable. An alternate ICCG algorithm for the Cray-1 was developed which utilizes a block form of the cyclic reduction algorithm. This new algorithm allows full vectorization and runs as much as five times faster than the old algorithm on the Cray-1. It is now being used in Cray LASNEX to solve the two-dimensional diffusion equation in all the physics subroutines mentioned above

From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

Science.gov (United States)

Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan

2017-01-01

Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903

Distinguishing new physics scenarios at a linear collider with polarized beams

International Nuclear Information System (INIS)

Pankov, A.A.; Tsytrinov, A.V.; Paver, N.

2006-01-01

Numerous nonstandard dynamics dominated by very high mass exchanges are described at current and future accelerator energies by appropriate contactlike effective interactions among the standard model particles. Correspondingly, they can manifest themselves only through deviations of the cross sections from the standard model predictions. If one such deviation were observed, it would be important to definitely identify, to a given confidence level, the actual source among the various possible nonstandard interactions that, in principle, can explain it. Here we estimate the identification reach on different new physics effective interactions, obtainable from angular distributions of lepton pair production processes at the planned electron-positron International Linear Collider with polarized beams. For each nonstandard model, such an identification reach defines the range in the relevant heavy mass scale parameter where it can be unambiguously distinguished from the other nonstandard models as the source of corrections to the standard model cross sections, in case these are observed. The effective interactions for which we estimate the expected identification reach are the interactions based on gravity in large extra dimensions, in TeV -1 extra dimensions and the compositeness-inspired four-fermion contact interactions. The availability of both beams polarized at the International Linear Collider turns out, in many cases, to dramatically enhance the identification sensitivity

Self-error-rejecting photonic qubit transmission in polarization-spatial modes with linear optical elements

Science.gov (United States)

Jiang, YuXiao; Guo, PengLiang; Gao, ChengYan; Wang, HaiBo; Alzahrani, Faris; Hobiny, Aatef; Deng, FuGuo

2017-12-01

We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom.

5G antenna array with wide-angle beam steering and dual linear polarizations

KAUST Repository

Klionovski, Kirill

2017-10-25

In this paper, we present the design of a switched-beam antenna array at millimeter-wave frequencies for future 5G applications. The proposed antenna array is based on wideband patch antenna elements and a Butler matrix feed network. The patch antenna has a broad radiation pattern for wide-angle beam steering and allows the simultaneous operation with two orthogonal linear polarizations. A combination of two separated Butler matrices provides independent beam steering for both polarizations in the wide operating band. The antenna array has a simple multilayer construction, and it is made on a low-cost Rogers laminate.

5G antenna array with wide-angle beam steering and dual linear polarizations

KAUST Repository

Klionovski, Kirill; Shamim, Atif; Sharawi, Mohammad Said

2017-01-01

In this paper, we present the design of a switched-beam antenna array at millimeter-wave frequencies for future 5G applications. The proposed antenna array is based on wideband patch antenna elements and a Butler matrix feed network. The patch antenna has a broad radiation pattern for wide-angle beam steering and allows the simultaneous operation with two orthogonal linear polarizations. A combination of two separated Butler matrices provides independent beam steering for both polarizations in the wide operating band. The antenna array has a simple multilayer construction, and it is made on a low-cost Rogers laminate.

The inference of vector magnetic fields from polarization measurements with limited spectral resolution

Science.gov (United States)

Lites, B. W.; Skumanich, A.

1985-01-01

A method is presented for recovery of the vector magnetic field and thermodynamic parameters from polarization measurement of photospheric line profiles measured with filtergraphs. The method includes magneto-optic effects and may be utilized on data sampled at arbitrary wavelengths within the line profile. The accuracy of this method is explored through inversion of synthetic Stokes profiles subjected to varying levels of random noise, instrumental wave-length resolution, and line profile sampling. The level of error introduced by the systematic effect of profile sampling over a finite fraction of the 5 minute oscillation cycle is also investigated. The results presented here are intended to guide instrumental design and observational procedure.

Strong-field non-sequential ionization: The vector momentum distribution of multiply charged Ne ions

International Nuclear Information System (INIS)

Rottke, H.; Trump, C.; Wittmann, M.; Korn, G.; Becker, W.; Hoffmann, K.; Sandner, W.; Moshammer, R.; Feuerstein, B.; Dorn, A.; Schroeter, C.D.; Ullrich, J.; Schmitt, W.

2000-01-01

COLTRIMS (COLd Target Recoil-Ion Momentum Spectroscopy) was used to measure the vector momentum distribution of Ne n+ (n=1,2,3) ions formed in ultrashort (30 fsec) high-intensity (≅10 15 W/cm 2 ) laser pulses with center wavelength at 795 nm. To a high degree of accuracy the length of the Ne n+ ion momentum vector is equal to the length of the total momentum vector of the n photoelectrons released, with both vectors pointing into opposite directions. At a light intensity where non-sequential ionization of the atom dominates the Ne 2+ and Ne 3+ momentum distributions show distinct maxima at 4.0 a.u. and 7.5 a.u. along the polarization axis of the linearly polarized light beam. First, this is a clear signature of non-sequential multiple ionization. Second, it indicates that instantaneous emission of two (or more) electrons at electric field strength maxima of the light wave can be ruled out as main mechanism of non-sequential strong-field multiple ionization. In contrast, this experimental result is in accordance with the kinematical constraints of the 'rescattering model'

Rare Hadronic B Decays to Vector, Axial-Vector and Tensors

International Nuclear Information System (INIS)

Gao, Y.Y.

2011-01-01

The authors review BABAR measurements of several rare B decays, including vector-axial-vector decays B ± → φK 1 ± (1270), B ± → φ K 1 ± (1400) and B ± → b 1 # -+ρ# ± , vector-vector decays B ± → φK* ± (1410), B 0 → K* 0 (bar K)* 0 , B 0 → K*0K*0 and B 0 → K*+K*-, vector-tensor decays B ± → φK* 2 (1430) ± and φK 2 (1770)/ ± (1820), and vector-scalar decays B ± → φK* 0 (1430) ± . Understanding the observed polarization pattern requires amplitude contributions from an uncertain source.

A New Method for Simulating Power Flow Density Focused by a Silicon Lens Antenna Irradiated with Linearly Polarized THz Wave

Directory of Open Access Journals (Sweden)

Catur Apriono

2015-08-01

Full Text Available A terahertz system uses dielectric lens antennas for focusing and collimating beams of terahertz wave radiation. Linearly polarized terahertz wave radiation has been widely applied in the terahertz system. Therefore, an accurate method for analyzing the power flow density in the dielectric lens antenna irradiated with the linearly polarized terahertz wave radiation is important to design the terahertz systems. In optics, ray-tracing method has been used to calculate the power flow density by a number density of rays. In this study, we propose a method of ray-tracing combined with Fresnel’s transmission, including transmittance and polarization of the terahertz wave radiation to calculate power flow density in a Silicon lens antenna. We compare power flow density calculated by the proposed method with the regular ray-tracing method. When the Silicon lens antenna is irradiated with linearly polarized terahertz wave radiation, the proposed method calculates the power flow density more accurately than the regular ray-tracing.

Generalized 2-vector spaces and general linear 2-groups

OpenAIRE

Elgueta, Josep

2008-01-01

In this paper a notion of {\\it generalized 2-vector space} is introduced which includes Kapranov and Voevodsky 2-vector spaces. Various kinds of generalized 2-vector spaces are considered and examples are given. The existence of non free generalized 2-vector spaces and of generalized 2-vector spaces which are non Karoubian (hence, non abelian) categories is discussed, and it is shown how any generalized 2-vector space can be identified with a full subcategory of an (abelian) functor category ...

Error of quantum-logic simulation via vector-soliton collisions

International Nuclear Information System (INIS)

Janutka, Andrzej

2007-01-01

In a concept of simulating the quantum logic with vector solitons by the author (Janutka 2006 J. Phys. A: Math. Gen. 39 12505), the soliton polarization is thought of as a state vector of a system of cebits (classical counterparts of qubits) switched via collisions with other solitons. The advantage of this method of information processing compared to schemes using linear optics is the possibility of the determination of the information-register state in a single measurement. Minimization of the information-processing error for different optical realizations of the logical systems is studied in the framework of a quantum analysis of soliton fluctuations. The problem is considered with relevance to general difficulties of the quantum error-correction schemes for the classical analogies of the quantum-information processing

Broadband asymmetric transmission of linearly polarized electromagnetic waves based on chiral metamaterial

Science.gov (United States)

Stephen, Lincy; Yogesh, N.; Subramanian, V.

2018-01-01

The giant optical activity of chiral metamaterials (CMMs) holds great potential for tailoring the polarization state of an electromagnetic (EM) wave. In controlling the polarization state, the aspect of asymmetric transmission (AT), where a medium allows the EM radiation to pass through in one direction while restricting it in the opposite direction, adds additional degrees of freedom such as one-way channelling functionality. In this work, a CMM formed by a pair of mutually twisted slanted complementary metal strips is realized for broadband AT accompanied with cross-polarization (CP) conversion for linearly polarized EM waves. Numerically, the proposed ultra-thin (˜λ/42) CMM shows broadband AT from 8.58 GHz to 9.73 GHz (bandwidth of 1.15 GHz) accompanied with CP transmission magnitude greater than 0.9. The transmission and reflection spectra reveal the origin of the asymmetric transmission as the direction sensitive cross polarization conversion and anisotropic electric coupling occurring in the structure which is then elaborated with the surface current analysis and electric field distribution within the structure. An experiment is carried out to verify the broadband AT based CP conversion of the proposed CMM at microwave frequencies, and a reliable agreement between numerical and experimental results is obtained. Being ultra-thin, the reported broadband AT based CP conversion of the proposed CMM is useful for controlling radiation patterns in non-reciprocal EM devices and communication networks.

Probing deformed orbitals with vector A( vector e, e' N)B reactions

International Nuclear Information System (INIS)

Garrido, E.; Caballero, J.A.; Moya de Guerra, E.; Sarriguren, P.; Udias, J.M.

1995-01-01

We present results for response functions and asymmetries in the nuclear reactions 37 vector Ar( vector e, e' n) 36 Ar and 37 vector K( vector e,e' p) 36 Ar at quasifree kinematics. We compare PWIA results obtained using deformed HF wave functions with PWIA and DWIA results obtained assuming a spherical mean field. We show that the complex structure of the deformed orbitals can be probed by coincidence measurements with polarized beam and targets. ((orig.))

Bhabha vs. Moeller scattering as a contact-interaction analyzer at a polarized linear collider

International Nuclear Information System (INIS)

Pankov, A.; Paver, N.

2002-10-01

We discuss electron-electron contact-interaction searches in the processes e + e - →e + e - and e - e - →e - e - at planned Linear Colliders run in the e + e - and e - e - modes with both beams longitudinally polarized. Our analysis is based on the measurement, for the two processes, of polarized differential cross sections, and allows to simultaneously take into account the general set of electron contact interaction couplings as independent, non-zero, parameters thus avoiding the simplifying choice of a model. We evaluate the corresponding model-independent constraints on the contact coupling constants, emphasizing the role of the available beam polarization and the complementarity, as far as the chirality of the constants is concerned, of the two processes in giving the best constraints. We also make a comparison with the potential of e + e - →μ μ- at the same energy and initial beams polarization. (author)

Dynamical model of coherent circularly polarized optical pulse interactions with two-level quantum systems

International Nuclear Information System (INIS)

Slavcheva, G.; Hess, O.

2005-01-01

We propose and develop a method for theoretical description of circularly (elliptically) polarized optical pulse resonant coherent interactions with two-level atoms. The method is based on the time-evolution equations of a two-level quantum system in the presence of a time-dependent dipole perturbation for electric dipole transitions between states with total angular-momentum projection difference (ΔJ z =±1) excited by a circularly polarized electromagnetic field [Feynman et al., J. Appl. Phys. 28, 49 (1957)]. The adopted real-vector representation approach allows for coupling with the vectorial Maxwell's equations for the optical wave propagation and thus the resulting Maxwell pseudospin equations can be numerically solved in the time domain without any approximations. The model permits a more exact study of the ultrafast coherent pulse propagation effects taking into account the vector nature of the electromagnetic field and hence the polarization state of the optical excitation. We demonstrate self-induced transparency effects and formation of polarized solitons. The model represents a qualitative extension of the well-known optical Maxwell-Bloch equations valid for linearly polarized light and a tool for studying coherent quantum control mechanisms

Neutron angular distribution in (γ, n reactions with linearly polarized γ-ray beam generated by laser Compton scattering

Directory of Open Access Journals (Sweden)

K. Horikawa

2014-10-01

Full Text Available In 1957, Agodi predicted that the neutron angular distribution in (γ, n reactions with a 100% linearly polarized γ-ray beam for dipole excitation should be anisotropic and universally described by the simple function of a+b⋅cos⁡(2ϕ at the polar angle θ=90°, where ϕ is the azimuthal angle. However, this prediction has not been experimentally confirmed in over half a century. We have verified experimentally this angular distribution in the (γ, n reaction for 197Au, 127I, and natural Cu targets using linearly polarized laser Compton scattering γ-rays. The result suggests that the (γ→, n reaction is a novel tool to study nuclear physics in the giant dipole resonance region.

LOW-FREQUENCY OBSERVATIONS OF LINEARLY POLARIZED STRUCTURES IN THE INTERSTELLAR MEDIUM NEAR THE SOUTH GALACTIC POLE

Energy Technology Data Exchange (ETDEWEB)

Lenc, E.; Gaensler, B. M.; Sun, X. H.; Sadler, E. M.; Callingham, J. R. [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia); Willis, A. G. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, P.O. Box 248, Penticton, BC (Canada); Barry, N.; Beardsley, A. P.; Carroll, P. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Bell, M. E.; Briggs, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Bernardi, G. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown 6140 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Oliveira-Costa, A. de; Dillon, J. S. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Deshpande, A. A.; Dwarkanath, K. S. [Raman Research Institute, Bangalore 560080 (India); Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); and others

2016-10-10

We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg{sup 2} centered on α = 0{sup h}and δ = −27°. The sensitivity available in our deep observations allows an in-band, frequency-dependent analysis of polarized structure for the first time at long wavelengths. Our analysis suggests that the polarized structures are dominated by intrinsic emission but may also have a foreground Faraday screen component. At these wavelengths, the compactness of the MWA baseline distribution provides excellent snapshot sensitivity to large-scale structure. The observations are sensitive to diffuse polarized emission at ∼54′ resolution with a sensitivity of 5.9 mJy beam{sup −1} and compact polarized sources at ∼2.′4 resolution with a sensitivity of 2.3 mJy beam{sup −1} for a subset (400 deg{sup 2}) of this field. The sensitivity allows the effect of ionospheric Faraday rotation to be spatially and temporally measured directly from the diffuse polarized background. Our observations reveal large-scale structures (∼1°–8° in extent) in linear polarization clearly detectable in ∼2 minute snapshots, which would remain undetectable by interferometers with minimum baseline lengths of >110 m at 154 MHz. The brightness temperature of these structures is on average 4 K in polarized intensity, peaking at 11 K. Rotation measure synthesis reveals that the structures have Faraday depths ranging from −2 to 10 rad m{sup −2} with a large fraction peaking at approximately +1 rad m{sup −2}. We estimate a distance of 51 ± 20 pc to the polarized emission based on measurements of the in-field pulsar J2330–2005. We detect four extragalactic linearly polarized point sources within the field in our compact source survey. Based on the known polarized source population at 1.4 GHz and non-detections at 154 MHz, we estimate an upper limit on the depolarization ratio of 0.08 from 1.4 GHz to 154 MHz.

Improved results for the 2H(d, n)3He transverse vector polarization-transfer coefficient Kyy'(0o) at low energies

International Nuclear Information System (INIS)

Roper, C.D.; Dunham, J.D.; Clegg, T.B.; Mendez, A.J.; Tornow, W.; Walter, R.L.

2010-01-01

Measurements of the 2 H(d, n) 3 He transverse vector polarization-transfer coefficient K y y' at 0 o . are reported for 29 outgoing neutron energies between 3.94 and 8.47 MeV. Our new results determine K y y' (0 o ) more accurately than previous data, especially for neutron energies below 5 MeV. Low-energy data for this reaction are important both as a high-intensity source of highly polarized neutrons for nuclear physics studies with polarized neutron beams, and as a test of the emerging theoretical descriptions of the four-body system, where recently substantial progress has been made. (author)

Macroscopic polarization in crystalline dielectrics: the geometric phase approach

International Nuclear Information System (INIS)

Resta, R.

1994-01-01

The macroscopic electric polarization of a crystal is often defined as the dipole of a unit cell. In fact, such a dipole moment is ill defined, and the above definition is incorrect. Looking more closely, the quantity generally measured is differential polarization, defined with respect to a ''reference state'' of the same material. Such differential polarizations include either derivatives of the polarization (dielectric permittivity, Born effective charges, piezoelectricity, pyroelectricity) or finite differences (ferroelectricity). On the theoretical side, the differential concept is basic as well. Owing to continuity, a polarization difference is equivalent to a macroscopic current, which is directly accessible to the theory as a bulk property. Polarization is a quantum phenomenon and cannot be treated with a classical model, particularly whenever delocalized valence electrons are present in the dielectric. In a quantum picture, the current is basically a property of the phase of the wave functions, as opposed to the charge, which is a property of their modulus. An elegant and complete theory has recently been developed by King-Smith and Vanderbilt, in which the polarization difference between any two crystal states--in a null electric field--takes the form of a geometric quantum phase. This gives a comprehensive account of this theory, which is relevant for dealing with transverse-optic phonons, piezoelectricity, and ferroelectricity. Its relation to the established concepts of linear-response theory is also discussed. Within the geometric phase approach, the relevant polarization difference occurs as the circuit integral of a Berry connection (or ''vector potential''), while the corresponding curvature (or ''magnetic field'') provides the macroscopic linear response

Diffraction model analysis of vector polarized 6Li elastic scattering on 12C, 16O, 28Si, and 58Ni nuclei

International Nuclear Information System (INIS)

Rabie, A.; El-Gazzar, M.A.; Abul-Magd, A.Y.

1980-11-01

Using an assumption concerning the spin-orbit potential, it was possible to reduce the five amplitudes of scattering of spin-1 projectiles to two amplitudes. The summations over the partial waves were evaluated by the Regge pole technique. The resulting simple expressions were used to analyze the data of the Heidelberg group for polarized 6 Li ions scattered on 12 C, 16 O, 28 Si and 58 Ni to give a reasonable fitting both for the differential cross-section and vector polarization. (author)

Polarization and alignment of nucleus fission fragments

International Nuclear Information System (INIS)

Barabanov, A.L.; Grechukhin, D.P.

1987-01-01

Correlation of fragment orientation with orientation axis of fissile nucleus and with n-vector f vector of fragment divergence is considered. Estimations of polarization and alignment of fission fragments of preliminarily oriented nuclei in correlation (with n-vector f recording) and integral (with n-vector f averaging) experiments were conducted. It is shown that high sensitivity of polarization and fragment alignment to the character of nucleus movement at the stage of descent from barrier to rupture point exists

Polarization observables of the d-vector p-vector → p-vector d reaction and one-neutron-exchange approximation

International Nuclear Information System (INIS)

Kobushkin, A.P.; Syamtomov, A.I.; Perdrisat, C.F.; Punjabi, V.

1994-01-01

The polarization observables in the elastic scattering of polarized deuterons on a polarized hydrogen target, with measurement of the recoil proton polarization, are considered. The observables are calculated in the one-neutron exchange approximation, for the special case of backward scattering (Θ c.m = 180 degree). Several new relations between polarization observables of the reaction are derived within the framework of this approximation. (author). 20 refs., 3 figs

Three-photon polarization ququarts: polarization, entanglement and Schmidt decompositions

International Nuclear Information System (INIS)

Fedorov, M V; Miklin, N I

2015-01-01

We consider polarization states of three photons, propagating collinearly and having equal given frequencies but with arbitrary distributed horizontal or vertical polarizations of photons. A general form of such states is a superposition of four basic three-photon polarization modes, to be referred to as the three-photon polarization ququarts (TPPQ). All such states can be considered as consisting of one- and two-photon parts, which can be entangled with each other. The degrees of entanglement and polarization, as well as the Schmidt decomposition and Stokes vectors of TPPQ are found and discussed. (paper)

Optical polarization maps of star-forming regions in Perseus, Taurus, and Ophiuchus

International Nuclear Information System (INIS)

Goodman, A.A.; Bastien, P.; Menard, F.; Myers, P.C.

1990-01-01

New optical linear polarization maps are presented of the star-forming regions near L1506 in Taurus, L1755 in Ophiuchus, and the complex of dark cloud which extends from L1448 in B5 in Perseus. The former two show a well-defined peak magnetic field direction in the plane of the sky with a finite dispersion about that peak which is smaller than would be expected for a random distribution of field distributions. The dispersion in the position angle of filamentary clouds within these complexes implies that clouds which appear elongated on the plane of the sky are not all associated with a pattern of polarization vectors particularly parallel or perpendicular to their geometry. Instead, clouds tend to be oriented at the angle formed by their axis and the mean direction of the local large-scale field. For the dark cloud complex, a bimodal distribution of the polarization vector angle is taken to result from at least two distributions of gas along the line of sight which appear as a complex in projection. 55 refs

Electroweak coupling measurements from polarized Bhabha scattering at the Z0 resonance

International Nuclear Information System (INIS)

Pitts, K.T.

1994-03-01

The cross section for Bhabha scattering (e + e - → e + e - ) with polarized electrons at the center of mass energy of the Z 0 resonance has been measured with the SLD experiment at the Stanford Linear Accelerator Center during the 1992 and 1993 runs. The electroweak couplings of the electron are extracted. At small angles the measurement is done in the SLD Silicon/Tungsten Luminosity Monitor (LMSAT). A detailed description of the design, construction, commissioning and operation of the LMSAT is provided. The integrated luminosity for 1992 is measured to be L = 420.86±2.56 (stat)±4.23 (sys) nb -1 . The luminosity asymmetry for polarized beams is measured to be A LR (LUM) = (1.7 ± 6.4) x 10 -3 . The large angle polarized Bhabha scattering reveals the effective electron vector and axial vector couplings to the Z 0 through the measurement of the Z 0 → e + e - partial width, Γ ee , and the parity violation parameter, A e . From the combined 1992 and 1993 data the effective electron vector and axial vector couplings are measured to be bar g v e = -0.0495±0.0096±0.0030, and bar g α e = -0.4977±0.0035±0.0064 respectively. The effective weak mixing angle is measured to be sin 2 θ W eff = 0.2251±0.0049±0.0015. These results are compared with other experiments

Polarization developments

International Nuclear Information System (INIS)

Prescott, C.Y.

1993-07-01

Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

Bhabha vs. Moeller scattering as a contact-interaction analyzer at a polarized linear collider

CERN Document Server

Pankov, A A

2002-01-01

We discuss electron-electron contact-interaction searches in the processes e sup + e sup -->e sup + e sup - and e sup - e sup -->e sup - e sup - at planned Linear Colliders run in the e sup + e sup - and e sup - e sup - modes with both beams longitudinally polarized. Our analysis is based on the measurement, for the two processes, of polarized differential cross sections, and allows to simultaneously take into account the general set of electron contact interaction couplings as independent, non-zero, parameters thus avoiding the simplifying choice of a model. We evaluate the corresponding model-independent constraints on the contact coupling constants, emphasizing the role of the available beam polarization and the complementarity, as far as the chirality of the constants is concerned, of the two processes in giving the best constraints. We also make a comparison with the potential of e sup + e sup --> mu supmu sup - at the same energy and initial beams polarization.

Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light

Energy Technology Data Exchange (ETDEWEB)

Shi, Xuetao; Li, Wen; Schlegel, H. Bernhard, E-mail: hbs@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

2016-08-28

The hydrogens in protonated acetylene are very mobile and can easily migrate around the C{sub 2} core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H{sub 2}CCH{sup +} ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C{sub 2}H{sub 3}{sup +} has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10{sup 13} W/cm{sup 2} and 3.15 × 10{sup 13} W/cm{sup 2}, respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C{sub 2}H{sub 3}{sup +}. The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C{sub 2} core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C{sub 2} core of protonated acetylene.

Multiscale asymmetric orthogonal wavelet kernel for linear programming support vector learning and nonlinear dynamic systems identification.

Science.gov (United States)

Lu, Zhao; Sun, Jing; Butts, Kenneth

2014-05-01

Support vector regression for approximating nonlinear dynamic systems is more delicate than the approximation of indicator functions in support vector classification, particularly for systems that involve multitudes of time scales in their sampled data. The kernel used for support vector learning determines the class of functions from which a support vector machine can draw its solution, and the choice of kernel significantly influences the performance of a support vector machine. In this paper, to bridge the gap between wavelet multiresolution analysis and kernel learning, the closed-form orthogonal wavelet is exploited to construct new multiscale asymmetric orthogonal wavelet kernels for linear programming support vector learning. The closed-form multiscale orthogonal wavelet kernel provides a systematic framework to implement multiscale kernel learning via dyadic dilations and also enables us to represent complex nonlinear dynamics effectively. To demonstrate the superiority of the proposed multiscale wavelet kernel in identifying complex nonlinear dynamic systems, two case studies are presented that aim at building parallel models on benchmark datasets. The development of parallel models that address the long-term/mid-term prediction issue is more intricate and challenging than the identification of series-parallel models where only one-step ahead prediction is required. Simulation results illustrate the effectiveness of the proposed multiscale kernel learning.

Analyzing power of AGATA triple clusters for gamma-ray linear polarization

Energy Technology Data Exchange (ETDEWEB)

Bizzeti, P.G.; Sona, P.; Melon, B.; Bizzeti-Sona, A.M.; Perego, A. [Universita di Firenze, Dipartimento di Fisica, Firenze (Italy); INFN, Firenze (Italy); Michelagnoli, C.; Lunardi, S.; Mengoni, D.; Recchia, F. [INFN, Padova (Italy); Universita di Padova, Dipartimento di Fisica, Padova (Italy); Bazzacco, D.; Farnea, E.; Menegazzo, R.; Ur, C.A. [INFN, Padova (Italy); De Angelis, G.; Gottardo, A.; Napoli, D.R.; Sahin, E.; Valiente-Dobon, J.J. [Laboratori Nazionali di Legnaro, INFN, Padova (Italy); Gadea, A. [University of Valencia, IFIC, CSIC, Valencia (Spain); Nannini, A. [INFN, Firenze (Italy)

2015-04-01

We have investigated the ability of AGATA triple clusters to measure the linear polarization of gamma rays, exploiting the azimuthal-angle dependence of the Compton scattering differential cross section. To this aim, partially polarized gamma rays have been produced by Coulomb excitation of the first excited state of {sup 104}Pd and {sup 108}Pd, which decay to the ground state by emission of gamma rays of 555.8 keV and 433.9 keV, respectively. Pulse-shape analysis and gamma-ray tracking techniques have been used to determine the position and time sequence of the interaction points inside the germanium crystals. Anisotropies in the detection efficiency have been taken into account using 661.6 keV gammas from a {sup 137}Cs radioactive source. We obtain an average analyzing power of 0.451(34) at 433.9 keV and 0.484(24) at 555.8 keV. (orig.)

Linear and support vector regressions based on geometrical correlation of data

Directory of Open Access Journals (Sweden)

Kaijun Wang

2007-10-01

Full Text Available Linear regression (LR and support vector regression (SVR are widely used in data analysis. Geometrical correlation learning (GcLearn was proposed recently to improve the predictive ability of LR and SVR through mining and using correlations between data of a variable (inner correlation. This paper theoretically analyzes prediction performance of the GcLearn method and proves that GcLearn LR and SVR will have better prediction performance than traditional LR and SVR for prediction tasks when good inner correlations are obtained and predictions by traditional LR and SVR are far away from their neighbor training data under inner correlation. This gives the applicable condition of GcLearn method.

Bistable states of TM polarized non-linear waves guided by symmetric layered structures

International Nuclear Information System (INIS)

Mihalache, D.

1985-04-01

Dispersion relations for TM polarized non-linear waves propagating in a symmetric single film optical waveguide are derived. The system consists of a layer of thickness d with dielectric constant epsilon 1 bounded at two sides by a non-linear medium characterized by the diagonal dielectric tensor epsilon 11 =epsilon 22 =epsilon 0 , epsilon 33 =epsilon 0 +α|E 3 | 2 , where E 3 is the normal electric field component. For sufficiently large d/lambda (lambda is the wavelength) we predict bistable states of both symmetric and antisymmetric modes provided that the power flow is the control parameter. (author)

A tensor and vector polarimeter for deuterons at fusion energies

Energy Technology Data Exchange (ETDEWEB)

Kroell, Leonard; Engels, Ralf; Gregoryev, Kyril; Mikirtychiants, Maxim; Mikirtychiants, Sergey; Rathmann, Frank; Stroeher, Hans [Institut fuer Kernphysik, Juelich Center for Hadron Physics, FZ Juelich (Germany); Kravtsov, Peter; Vasilyev, Alexander [High Energy Physics Department, PNPI (Russian Federation); Paetz, Hans [Institut fuer Kernphysik, Universitaet Koeln (Germany); Hebbeker, Thomas [III. Physikalisches Institut A, RWTH, Aachen (Germany)

2010-07-01

Within the framework of an ISTC project the fusion reactions of double-polarized deuterium (vector (d)+vector (d){yields} {sup 3}H+p, vector (d)+vector (d){yields} {sup 3}He+n) will be analysed in order to study the influence of the vector and tensor polarization of the initial projectiles on the total cross sections. These results allow a conclusion on the change of the branching ration between the two fusion channels and, therefore, the neutron reduction for a future generation of fusion reactor. The measurements request the knowledge of the polarization of the deuteron beam and of the (gas)target. With an unpolarized target, the beam polarization can be determined by measuring the angular distributions of the outgoing particles ({sup 3}He, p and {sup 3}H) with use of the known analysing powers. Vice versa, additional data for the analysing powers can be obtained with a beam of known polarization, measured with a Lamb-shift polarimeter. The setup of the charged ejectile polarimeters is described.

NONLINEAR REFLECTION PROCESS OF LINEARLY POLARIZED, BROADBAND ALFVÉN WAVES IN THE FAST SOLAR WIND

Energy Technology Data Exchange (ETDEWEB)

Shoda, M.; Yokoyama, T., E-mail: shoda@eps.s.u-tokyo.ac.jp [Department of Earth and Planetary Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2016-04-01

Using one-dimensional numerical simulations, we study the elementary process of Alfvén wave reflection in a uniform medium, including nonlinear effects. In the linear regime, Alfvén wave reflection is triggered only by the inhomogeneity of the medium, whereas in the nonlinear regime, it can occur via nonlinear wave–wave interactions. Such nonlinear reflection (backscattering) is typified by decay instability. In most studies of decay instabilities, the initial condition has been a circularly polarized Alfvén wave. In this study we consider a linearly polarized Alfvén wave, which drives density fluctuations by its magnetic pressure force. For generality, we also assume a broadband wave with a red-noise spectrum. In the data analysis, we decompose the fluctuations into characteristic variables using local eigenvectors, thus revealing the behaviors of the individual modes. Different from the circular-polarization case, we find that the wave steepening produces a new energy channel from the parent Alfvén wave to the backscattered one. Such nonlinear reflection explains the observed increasing energy ratio of the sunward to the anti-sunward Alfvénic fluctuations in the solar wind with distance against the dynamical alignment effect.

Linear Matrix Inequalities for Analysis and Control of Linear Vector Second-Order Systems

DEFF Research Database (Denmark)

Adegas, Fabiano Daher; Stoustrup, Jakob

2015-01-01

the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems......SUMMARY Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between....... The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form. Copyright © 2014 John Wiley & Sons, Ltd....

Angular distributions as a probe of anomalous ZZH and γZH interactions at a linear collider with polarized beams

International Nuclear Information System (INIS)

Rindani, Saurabh D.; Sharma, Pankaj

2009-01-01

We examine the contribution of general Z*ZH and γ*ZH three-point interactions arising from new physics to the Higgs production process e + e - →HZ. From Lorentz covariance, each of these vertices may be written in terms of three (complex) form factors, whose real and imaginary parts together make six independent couplings. We take into account possible longitudinal or transverse beam polarization likely to be available at a linear collider. We show how partial cross sections and angular asymmetries in suitable combinations with appropriate beam polarizations can be used to disentangle various couplings from one another. A striking result is that using transverse polarization, one of the γZH couplings, not otherwise accessible, can be determined independently of all other couplings. Transverse polarization also helps in the independent determination of a combination of two other couplings, in contrast to a combination of four accessible with unpolarized or longitudinally polarized beams. We also obtain the sensitivity of the various observables in constraining the new-physics interactions at a linear collider operating at a center-of-mass energy of 500 GeV with longitudinal or transverse polarization.

Measurement of the Electric Form Factor of the Neutron through d-vector(e-vector, e'n)p

International Nuclear Information System (INIS)

Hongguo Zhu; Abdellah Ahmidouch; Anklin, H.; Arenhoevel, H.; Chris Armstrong; C. Bernet; Werner Boeglin; Herbert Breuer; Paul Brindza; D. Brown; S. Bueltmann; Roger Carlini; Nicholas Chant; Anthony Cowley; Donald Crabb; Samuel Danagoulian; D. B. Day; Tom Eden; Rolf Ent; Yusuf Farah; Renee Fatimi; Kenneth Garrow; Chris Harris; Markus Hauger; A. Honegger; J. Jourdan; M. Kaufmann; Mahbub Khandaker; Gunther Kubon; Jechiel Lichtenstadt; Richard Lindgren; Robert Lourie; Allison Lung; David Mack; Sudhir Malik; Pete Markowitz; Kenneth McFarlane; Paul McKee; Dustin McNulty; Geoffrey Milanovich; Joseph Mitchell; Hamlet Mkrtchyan; M. Muehlbauer; Thomas Petitjean; Yelena Prok; Daniela Rohe; Emmanuel Rollinde; Oscar Rondon-Aramayo; Philip Roos; Reyad Sawafta; Ingo Sick; C. Smith; Tim Southern; Michael Steinacher; Stepan Stepanyan; Vardan Tadevosyan; Raphael Tieulent; Al Tobias; Bill Vulcan; Glen Warren; H. Woehrle; Stephen Wood; Chen Yan; Marko Zeier; Jianguo Zhao; Beni Zihlmann

2001-01-01

We report the first measurement using a solid polarized target of the neutron electric form factor G n E via d-vector(e-vector, e'n)p. G n E was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ( 15 ND 3 ). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find G n E = 0.04632±0.00616(stat)±0.00341(syst) at Q 2 = 0.495 (GeV/c) 2

Gamma-ray linear polarization measurements following heavy-ion bombardment of odd isotopes of Pd

International Nuclear Information System (INIS)

Kim, J.S.; Lee, Y.K.; Hardy, K.A.; Simms, P.C.; Grau, J.A.; Smith, G.J.; Rickey, F.A.

1975-01-01

γ-ray linear polarization measurements have been used to locate negative parity states in the even-odd isotopes 99 , 101 , 103 Pd. A Compton polarimeter based on two Ge(Li) coaxial detectors was used. Collective bands (I=11 - /2, 15 - /2, 19 - /2, . . .) bulit on 11 - /2 states were observed in 101 Pd and 103 Pd. Many negative parity states were also observed in 99 Pd, but they do not appear to be part of a similar collective band. These polarization measurements also confirm many angular momentum assignments which previously had been made using systematic arguments

Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar

International Nuclear Information System (INIS)

Gandini, Paolo

2012-01-01

We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f L in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f L ∼ 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B → ρρ and B + → (Omega)ρ + decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f L ∼ 0.5 in B → φK* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.

Research of the impact of coupling between unit cells on performance of linear-to-circular polarization conversion metamaterial with half transmission and half reflection

Science.gov (United States)

Guo, Mengchao; Zhou, Kan; Wang, Xiaokun; Zhuang, Haiyan; Tang, Dongming; Zhang, Baoshan; Yang, Yi

2018-04-01

In this paper, the impact of coupling between unit cells on the performance of linear-to-circular polarization conversion metamaterial with half transmission and half reflection is analyzed by changing the distance between the unit cells. An equivalent electrical circuit model is then built to explain it based on the analysis. The simulated results show that, when the distance between the unit cells is 23 mm, this metamaterial converts half of the incident linearly-polarized wave into reflected left-hand circularly-polarized wave and converts the other half of it into transmitted left-hand circularly-polarized wave at 4.4 GHz; when the distance is 28 mm, this metamaterial reflects all of the incident linearly-polarized wave at 4.4 GHz; and when the distance is 32 mm, this metamaterial converts half of the incident linearly-polarized wave into reflected right-hand circularly-polarized wave and converts the other half of it into transmitted right-hand circularly-polarized wave at 4.4 GHz. The tunability is realized successfully. The analysis shows that the changes of coupling between unit cells lead to the changes of performance of this metamaterial. The coupling between the unit cells is then considered when building the equivalent electrical circuit model. The built equivalent electrical circuit model can be used to perfectly explain the simulated results, which confirms the validity of it. It can also give help to the design of tunable polarization conversion metamaterials.

Imaging linear and circular polarization features in leaves with complete Mueller matrix polarimetry.

Science.gov (United States)

Patty, C H Lucas; Luo, David A; Snik, Frans; Ariese, Freek; Buma, Wybren Jan; Ten Kate, Inge Loes; van Spanning, Rob J M; Sparks, William B; Germer, Thomas A; Garab, Győző; Kudenov, Michael W

2018-06-01

Spectropolarimetry of intact plant leaves allows to probe the molecular architecture of vegetation photosynthesis in a non-invasive and non-destructive way and, as such, can offer a wealth of physiological information. In addition to the molecular signals due to the photosynthetic machinery, the cell structure and its arrangement within a leaf can create and modify polarization signals. Using Mueller matrix polarimetry with rotating retarder modulation, we have visualized spatial variations in polarization in transmission around the chlorophyll a absorbance band from 650 nm to 710 nm. We show linear and circular polarization measurements of maple leaves and cultivated maize leaves and discuss the corresponding Mueller matrices and the Mueller matrix decompositions, which show distinct features in diattenuation, polarizance, retardance and depolarization. Importantly, while normal leaf tissue shows a typical split signal with both a negative and a positive peak in the induced fractional circular polarization and circular dichroism, the signals close to the veins only display a negative band. The results are similar to the negative band as reported earlier for single macrodomains. We discuss the possible role of the chloroplast orientation around the veins as a cause of this phenomenon. Systematic artefacts are ruled out as three independent measurements by different instruments gave similar results. These results provide better insight into circular polarization measurements on whole leaves and options for vegetation remote sensing using circular polarization. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Measurements of the n vector p vector total cross section differences for pure helicity states at 1.20, 2.50 and 3.66 GeV

International Nuclear Information System (INIS)

Sharov, V.I.; Zaporozhets, S.A.; Ad''yasevich, B.P.

1996-01-01

The quantity Δσ L (n vector p vector), the difference of n vector p vector total cross sections for antiparallel and parallel longitudinal (L) spin states, has been measured for the first time in an energy region of several GeV using a free polarized neutron beam and a polarized proton target. The new data are discussed together with existing results and modern theoretical predictions. This is the first of a planned series of measurements of Δσ L,T (n vector p vector) in this new energy region. 28 refs., 3 figs

Techniques for vector analyzing power measurements of the 2H(n vector,np)n breakup reaction at low energies

International Nuclear Information System (INIS)

Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L.; Lambert, J.M.; Treado, P.A.

1990-01-01

Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the 2 H(d vector, n vector) 3 He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.)

Room-temperature single-photon sources with definite circular and linear polarizations based on single-emitter fluorescence in liquid crystal hosts

International Nuclear Information System (INIS)

Winkler, Justin M; Lukishova, Svetlana G; Bissell, Luke J

2013-01-01

Definite circular and linear polarizations of room-temperature single-photon sources, which can serve as polarization bases for quantum key distribution, are produced by doping planar-aligned liquid crystal hosts with single fluorescence emitters. Chiral 1-D photonic bandgap microcavities for a single handedness of circularly polarized light were prepared from both monomeric and oligomeric cholesteric liquid crystals. Fluorescent emitters, such as nanocrystal quantum dots, nitrogen vacancy color centers in nanodiamonds, and rare-earth ions in nanocrystals, were doped into these microcavity structures and used to produce circularly polarized fluorescence of definite handedness. Additionally, we observed circularly polarized resonances in the spectrum of nanocrystal quantum dot fluorescence at the edge of the cholesteric microcavity's photonic stopband. For this polarization we obtained a ∼4.9 enhancement of intensity compared to the polarization of the opposite handedness that propagates without photonic bandgap microcavity effects. Such a resonance is indicative of coupling of quantum dot fluorescence to the cholesteric microcavity mode. We have also used planar-aligned nematic liquid crystal hosts to align DiI dye molecules doped into the host, thereby providing a single-photon source of linear polarization of definite direction. Antibunching is demonstrated for fluorescence of nanocrystal quantum dots, nitrogen vacancy color centers, and dye molecules in these liquid crystal structures.

Non-uniformly polarized beams across their transverse profiles: an introductory study for undergraduate optics courses

International Nuclear Information System (INIS)

Piquero, Gemma; Vargas-Balbuena, Javier

2004-01-01

We provide a simple theoretical study of beams non-uniformly polarized across their transverse sections which can be introduced in undergraduate optics courses. In order to generate such beams we propose to use a slightly convergent (or divergent) linearly and uniformly polarized beam impinging on an anisotropic uniaxial material with the beam propagation direction along the optic axis. Analytical expressions for the Jones vector, Stokes parameters, ellipticity and azimuth at each point of the transverse section, perpendicular to the propagation direction, are obtained at the output of this system. By means of these parameters a detailed description of the state of polarization across the transverse profile is given

Linearized vector radiative transfer model MCC++ for a spherical atmosphere

International Nuclear Information System (INIS)

Postylyakov, O.V.

2004-01-01

Application of radiative transfer models has shown that optical remote sensing requires extra characteristics of radiance field in addition to the radiance intensity itself. Simulation of spectral measurements, analysis of retrieval errors and development of retrieval algorithms are in need of derivatives of radiance with respect to atmospheric constituents under investigation. The presented vector spherical radiative transfer model MCC++ was linearized, which allows the calculation of derivatives of all elements of the Stokes vector with respect to the volume absorption coefficient simultaneously with radiance calculation. The model MCC++ employs Monte Carlo algorithm for radiative transfer simulation and takes into account aerosol and molecular scattering, gas and aerosol absorption, and Lambertian surface albedo. The model treats a spherically symmetrical atmosphere. Relation of the estimated derivatives with other forms of radiance derivatives: the weighting functions used in gas retrieval and the air mass factors used in the DOAS retrieval algorithms, is obtained. Validation of the model against other radiative models is overviewed. The computing time of the intensity for the MCC++ model is about that for radiative models treating sphericity of the atmosphere approximately and is significantly shorter than that for the full spherical models used in the comparisons. The simultaneous calculation of all derivatives (i.e. with respect to absorption in all model atmosphere layers) and the intensity is only 1.2-2 times longer than the calculation of the intensity only

Distinguishing new physics scenarios at a linear collider with polarized beams

International Nuclear Information System (INIS)

Pankov, A.A.; Paver, N.; Tsytrinov, A.V.

2005-12-01

Numerous non-standard dynamics are described by contact-like effective interactions that can manifest themselves only through deviations of the cross sections from the Standard Model predictions. If one such deviation were observed, it should be important to definitely identify, to a given confidence level, the actual source among the possible non-standard interactions that in principle can explain it. We here estimate the 'identification' reach on different New Physics effective interactions obtainable from angular distributions of lepton pair production processes at the planned International Linear Collider with polarized beams. The models for which we discuss the range in the relevant high mass scales where they can be 'identified' as sources of corrections from the Standard Model predictions, are the interactions based on gravity in large and in TeV -1 extra dimensions and the compositeness-inspired four-fermion contact interactions. The availability of both beams polarized in many cases plays an essential role in enhancing the identification sensitivity. (author)

Off-diagonal helicity density matrix elements for vector mesons produced in polarized e+e- processes

International Nuclear Information System (INIS)

Anselmino, M.; Murgia, F.; Quintairos, P.

1999-04-01

Final state q q-bar interactions give origin to non zero values of the off-diagonal element ρ 1,-1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ, D * and K * 's. New predictions are given for ρ 1,-1 of several mesons produced at large x E and small p T - i.e. collinear with the parent jet - in the annihilation of polarized 3 + and 3 - , the results depend strongly on the elementary dynamics and allow further non trivial tests of the standard model. (author)

Propagation of gravitational waves in the generalized tensor-vector-scalar theory

International Nuclear Information System (INIS)

Sagi, Eva

2010-01-01

Efforts are underway to improve the design and sensitivity of gravitational wave detectors, with the hope that the next generation of these detectors will observe a gravitational wave signal. Such a signal will not only provide information on dynamics in the strong gravity regime that characterizes potential sources of gravitational waves, but will also serve as a decisive test for alternative theories of gravitation that are consistent with all other current experimental observations. We study the linearized theory of the tensor-vector-scalar theory of gravity with generalized vector action, an alternative theory of gravitation designed to explain the apparent deficit of visible matter in galaxies and clusters of galaxies without postulating yet-undetected dark matter. We find the polarization states and propagation speeds for gravitational waves in vacuum, and show that in addition to the usual transverse-traceless propagation modes, there are two more mixed longitudinal-transverse modes and two trace modes, of which at least one has longitudinal polarization. Additionally, the propagation speeds are different from the speed of light.

Scanning differential polarization microscope: Its use to image linear and circular differential scattering

International Nuclear Information System (INIS)

Mickols, W.; Maestre, M.F.

1988-01-01

A differential polarization microscope that couples the sensitivity of single-beam measurement of circular dichroism and circular differential scattering with the simultaneous measurement of linear dichroism and linear differential scattering has been developed. The microscope uses a scanning microscope stage and single-point illumination to give the very shallow depth of field found in confocal microscopy. This microscope can operate in the confocal mode as well as in the near confocal condition that can allow one to program the coherence and spatial resolution of the microscope. This microscope has been used to study the change in the structure of chromatin during the development of sperm in Drosophila

Magnetic Field-Vector Measurements in Quiescent Prominences via the Hanle Effect: Analysis of Prominences Observed at Pic-Du-Midi and at Sacramento Peak

Science.gov (United States)

Bommier, V.; Leroy, J. L.; Sahal-Brechot, S.

1985-01-01

The Hanle effect method for magnetic field vector diagnostics has now provided results on the magnetic field strength and direction in quiescent prominences, from linear polarization measurements in the He I E sub 3 line, performed at the Pic-du-Midi and at Sacramento Peak. However, there is an inescapable ambiguity in the field vector determination: each polarization measurement provides two field vector solutions symmetrical with respect to the line-of-sight. A statistical analysis capable of solving this ambiguity was applied to the large sample of prominences observed at the Pic-du-Midi (Leroy, et al., 1984); the same method of analysis applied to the prominences observed at Sacramento Peak (Athay, et al., 1983) provides results in agreement on the most probable magnetic structure of prominences; these results are detailed. The statistical results were confirmed on favorable individual cases: for 15 prominences observed at Pic-du-Midi, the two-field vectors are pointing on the same side of the prominence, and the alpha angles are large enough with respect to the measurements and interpretation inaccuracies, so that the field polarity is derived without any ambiguity.

112 Gbit/s single-polarization silicon coherent receiver with hybrid-integrated BiCMOS linear TIA

NARCIS (Netherlands)

Verbist, J.; Zhang, J.; Moeneclaey, B.; van Weerdenburg, J.; van Uden, R.; Okonkwo, C.; Yin, X.; Bauwelinck, J.; Roelkens, G.

2015-01-01

We report the design, fabrication and verification of a single-polarization silicon coherent receiver with a low-power linear TIA array. Error-free operation assuming FEC is shown at bitrates of 112 Gbit/s (28 Gbaud 16-QAM) and 56 Gbit/s (28 Gbaud QPSK).

Current error vector based prediction control of the section winding permanent magnet linear synchronous motor

Energy Technology Data Exchange (ETDEWEB)

Hong Junjie, E-mail: hongjjie@mail.sysu.edu.cn [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China); Li Liyi, E-mail: liliyi@hit.edu.cn [Dept. Electrical Engineering, Harbin Institute of Technology, Harbin 150000 (China); Zong Zhijian; Liu Zhongtu [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China)

2011-10-15

Highlights: {yields} The structure of the permanent magnet linear synchronous motor (SW-PMLSM) is new. {yields} A new current control method CEVPC is employed in this motor. {yields} The sectional power supply method is different to the others and effective. {yields} The performance gets worse with voltage and current limitations. - Abstract: To include features such as greater thrust density, higher efficiency without reducing the thrust stability, this paper proposes a section winding permanent magnet linear synchronous motor (SW-PMLSM), whose iron core is continuous, whereas winding is divided. The discrete system model of the motor is derived. With the definition of the current error vector and selection of the value function, the theory of the current error vector based prediction control (CEVPC) for the motor currents is explained clearly. According to the winding section feature, the motion region of the mover is divided into five zones, in which the implementation of the current predictive control method is proposed. Finally, the experimental platform is constructed and experiments are carried out. The results show: the current control effect has good dynamic response, and the thrust on the mover remains constant basically.

Spin-isospin excitations studied by polarized beams

International Nuclear Information System (INIS)

Sakai, H.; Greenfield, M.B.; Hatanaka, K.

1996-01-01

The spin-parity J π of the spin dipole resonances (SDR) in 12 N and 12 B are investigated via the measurements of polarization observables, the transverse polarization transfer coefficient D NN for the (vector p, vector n) reaction at 197 and 295 MeV and the tensor analyzing power A xx for the (vector d, 2 He) reaction at 270 MeV. The polarization observables, D NN and A xx for the peak at 4.5 MeV are consistent with the DWIA prediction with 2 - but those for the peak at 7.5 MeV contradict the predictions with an expected J π =1 - . Neither polarization observables could detect any concentration of 0 - strength. The usefulness of these spin observables in identifying J π is shown. (orig.)

Ultra-wideband high-efficiency reflective linear-to-circular polarization converter based on metasurface at terahertz frequencies.

Science.gov (United States)

Jiang, Yannan; Wang, Lei; Wang, Jiao; Akwuruoha, Charles Nwakanma; Cao, Weiping

2017-10-30

The polarization conversion of electromagnetic (EM) waves, especially linear-to-circular (LTC) polarization conversion, is of great significance in practical applications. In this study, we propose an ultra-wideband high-efficiency reflective LTC polarization converter based on a metasurface in the terahertz regime. It consists of periodic unit cells, each cell of which is formed by a double split resonant square ring, dielectric layer, and fully reflective gold mirror. In the frequency range of 0.60 - 1.41 THz, the magnitudes of the reflection coefficients reach approximately 0.7, and the phase difference between the two orthogonal electric field components of the reflected wave is close to 90° or -270°. The results indicate that the relative bandwidth reaches 80% and the efficiency is greater than 88%, thus, ultra-wideband high-efficiency LTC polarization conversion has been realized. Finally, the physical mechanism of the polarization conversion is revealed. This converter has potential applications in antenna design, EM measurement, and stealth technology.

Spin Flipping and Polarization Lifetimes of a 270 MeV Deuteron Beam

International Nuclear Information System (INIS)

Morozov, V.S.; Crawford, M.Q.; Etienne, Z.B.; Kandes, M.C.; Krisch, A.D.; Leonova, M.A.; Sivers, D.W.; Wong, V.K.; Yonehara, K.; Anferov, V.A.; Meyer, H.O.; Schwandt, P.; Stephenson, E.J.; Przewoski, B. von

2003-01-01

We recently studied the spin flipping of a 270 MeV vertically polarized deuteron beam stored in the IUCF Cooler Ring. We swept an rf solenoid's frequency through an rf-induced spin resonance and observed the effect on the beam's vector and tensor polarizations. After optimizing the resonance crossing rate and setting the solenoid's voltage to its maximum value, we obtained a spin-flip efficiency of about 94 ± 1% for the vector polarization; we also observed a partial spin-flip of the tensor polarization. We then used the rf-induced resonance to measure the vector and tensor polarizations' lifetimes at different distances from the resonance; the polarization lifetime ratio τvector/τtensor was about 1.9 ± 0.4

Understanding Effect of Constraint Release Environment on End-to-End Vector Relaxation of Linear Polymer Chains

KAUST Repository

Shivokhin, Maksim E.

2017-05-30

We propose and verify methods based on the slip-spring (SSp) model [ Macromolecules 2005, 38, 14 ] for predicting the effect of any monodisperse, binary, or ternary environment of topological constraints on the relaxation of the end-to-end vector of a linear probe chain. For this purpose we first validate the ability of the model to consistently predict both the viscoelastic and dielectric response of monodisperse and binary mixtures of type A polymers, based on published experimental data. We also report the synthesis of new binary and ternary polybutadiene systems, the measurement of their linear viscoelastic response, and the prediction of these data by the SSp model. We next clarify the relaxation mechanisms of probe chains in these constraint release (CR) environments by analyzing a set of "toy" SSp models with simplified constraint release rates, by examining fluctuations of the end-to-end vector. In our analysis, the longest relaxation time of the probe chain is determined by a competition between the longest relaxation times of the effective CR motions of the fat and thin tubes and the motion of the chain itself in the thin tube. This picture is tested by the analysis of four model systems designed to separate and estimate every single contribution involved in the relaxation of the probe\\'s end-to-end vector in polydisperse systems. We follow the CR picture of Viovy et al. [ Macromolecules 1991, 24, 3587 ] and refine the effective chain friction in the thin and fat tubes based on Read et al. [ J. Rheol. 2012, 56, 823 ]. The derived analytical equations form a basis for generalizing the proposed methodology to polydisperse mixtures of linear and branched polymers. The consistency between the SSp model and tube model predictions is a strong indicator of the compatibility between these two distinct mesoscopic frameworks.

Realization of beam polarization at the linear collider and its application to EW processes

Energy Technology Data Exchange (ETDEWEB)

Franco-Sollova, F.

2006-07-15

The use of beam polarization at the future ILC e{sup +}e{sup -} linear collider will benefit the physics program significantly. This thesis explores three aspects of beam polarization: the application of beam polarization to the study of electroweak processes, the precise measurement of the beam polarization, and finally, the production of polarized positrons at a test beam experiment. In the first part of the thesis the importance of beam polarization at the future ILC is exhibited: the benefits of employing transverse beam polarization (in both beams) for the measurement of triple gauge boson couplings (TGCs) in the W-pair production process are studied. The sensitivity to anomalous TGC values is compared for the cases of transverse and longitudinal beam polarization at a center of mass energy of 500 GeV. Due to the suppressed contribution of the t-channel {nu} exchange, the sensitivity is higher for longitudinal polarization. For some physics analyses the usual polarimetry techniques do not provide the required accuracy for the measurement of the beam polarization (around 0.25% with Compton polarimetry). The second part of the thesis deals with a complementary method to measure the beam polarization employing physics data acquired with two polarization modes. The process of single-W production is chosen due to its high cross section. The expected precision for 500 fb{sup -1} and W{yields}{mu}{nu} decays only, is {delta}P{sub e{sup -}}/P{sub e{sup -}}=0.26% and {delta}P{sub e{sup +}}/P{sub e{sup +}}=0.33%, which can be further improved by employing additional W-decay channels. The first results of an attempt to produce polarized positrons at the E-166 experiment are shown in the last part of the thesis. The E-166 experiment, located at the Final Focus Test Beam at SLAC's LINAC employs a helical undulator to induce the emission of circularly polarized gamma rays by the beam electrons. These gamma rays are converted into longitudinally polarized electron

The evolution of tensor polarization

International Nuclear Information System (INIS)

Huang, H.; Lee, S.Y.; Ratner, L.

1993-01-01

By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

Reduced Order Extended Luenberger Observer Based Sensorless Vector Control Fed by Matrix Converter with Non-linearity Modeling

DEFF Research Database (Denmark)

Lee, Kyo-Beum; Blaabjerg, Frede

2004-01-01

This paper presents a new sensorless vector control system for high performance induction motor drives fed by a matrix converter with non-linearity compensation. The nonlinear voltage distortion that is caused by commutation delay and on-state voltage drop in switching device is corrected by a new...

X-Parameter Based Modelling of Polar Modulated Power Amplifiers

DEFF Research Database (Denmark)

Wang, Yelin; Nielsen, Troels Studsgaard; Sira, Daniel

2013-01-01

X-parameters are developed as an extension of S-parameters capable of modelling non-linear devices driven by large signals. They are suitable for devices having only radio frequency (RF) and DC ports. In a polar power amplifier (PA), phase and envelope of the input modulated signal are applied...... at separate ports and the envelope port is neither an RF nor a DC port. As a result, X-parameters may fail to characterise the effect of the envelope port excitation and consequently the polar PA. This study introduces a solution to the problem for a commercial polar PA. In this solution, the RF-phase path...... PA for simulations. The simulated error vector magnitude (EVM) and adjacent channel power ratio (ACPR) were compared with the measured data to validate the model. The maximum differences between the simulated and measured EVM and ACPR are less than 2% point and 3 dB, respectively....

Spatial anisotropy of neutrons emitted from the 56Fe(γ ,n )55Fe reaction with a linearly polarized γ -ray beam

Science.gov (United States)

Hayakawa, T.; Shizuma, T.; Miyamoto, S.; Amano, S.; Takemoto, A.; Yamaguchi, M.; Horikawa, K.; Akimune, H.; Chiba, S.; Ogata, K.; Fujiwara, M.

2016-04-01

We have measured the azimuthal anisotropy of neutrons emitted from the 56Fe(γ ,n )55Fe reaction with a linearly polarized γ -ray beam generated by laser Compton scattering at NewSUBARU. Neutron yields at the polar angle of 90∘ have been measured as a function of the azimuthal angle ϕ between the detector and the linear polarization plane of the γ -ray beam. The azimuthal anisotropy of neutrons measured at ϕ =0∘ , 10∘, 25∘, 45∘, 60∘, 70∘, and 90∘ has been well reproduced using a theoretically predicted function of a +b cos(2 ϕ ) .

Wigner's little group as a gauge generator in linearized gravity theories

International Nuclear Information System (INIS)

Scaria, Tomy; Chakraborty, Biswajit

2002-01-01

We show that the translational subgroup of Wigner's little group for massless particles in 3 + 1 dimensions generates gauge transformation in linearized Einstein gravity. Similarly, a suitable representation of the one-dimensional translational group T(1) is shown to generate gauge transformation in the linearized Einstein-Chern-Simons theory in 2 + 1 dimensions. These representations are derived systematically from appropriate representations of translational groups which generate gauge transformations in gauge theories living in spacetime of one higher dimension by the technique of dimensional descent. The unified picture thus obtained is compared with a similar picture available for vector gauge theories in 3 + 1 and 2 + 1 dimensions. Finally, the polarization tensor of the Einstein-Pauli-Fierz theory in 2 + 1 dimensions is shown to split into the polarization tensors of a pair of Einstein-Chern-Simons theories with opposite helicities suggesting a doublet structure for the Einstein-Pauli-Fierz theory

First measurement of the helicity-dependent vector gamma)vector(p)->p eta differential cross-section

CERN Document Server

Ahrens, J; Aulenbacher, K; Beck, R; Drechsel, D; Von Harrach, D; Heid, E; Altieri, S; Annand, J R M; Anton, G; Bradtke, C; Görtz, S; Harmsen, J; Braghieri, A; D'Hose, N; Dutz, H; Grabmayr, P; Hansen, K; Hasegawa, S; Hasegawa, T; Helbing, K; Holvoet, H; Van Hoorebeke, L; Horikawa, N; Iwata, T; Jahn, O; Jennewein, P; Kageya, T; Kiel, B; Klein, F; Kondratiev, R; Kossert, K; Krimmer, J; Lang, M; Lannoy, B; Leukel, R; Lisin, V; Matsuda, T; McGeorge, J C; Meier, A; Menze, D; Meyer, Werner T; Michel, T; Naumann, J; Panzeri, A; Pedroni, P; Pinelli, T; Preobrajenski, I; Radtke, E; Reichert, E; Reicherz, G; Rohlof, C; Rosner, G; Ryckbosch, D; Sauer, M C; Schoch, B; Schumacher, M; Seitz, B; Speckner, T; Takabayashi, N; Tamas, G; Thomas, A; Van De Vyver, R; Wakai, A; Weihofen, W; Wissmann, F; Zapadtka, F; Zeitler, G

2003-01-01

The helicity dependence of the vector(gamma)vector(p)->p eta reaction has been measured for the first time at a center-of-mass angle theta sup * subeta=70 in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4 pi-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis. (orig.)

Vector regression introduced

Directory of Open Access Journals (Sweden)

Mok Tik

2014-06-01

Full Text Available This study formulates regression of vector data that will enable statistical analysis of various geodetic phenomena such as, polar motion, ocean currents, typhoon/hurricane tracking, crustal deformations, and precursory earthquake signals. The observed vector variable of an event (dependent vector variable is expressed as a function of a number of hypothesized phenomena realized also as vector variables (independent vector variables and/or scalar variables that are likely to impact the dependent vector variable. The proposed representation has the unique property of solving the coefficients of independent vector variables (explanatory variables also as vectors, hence it supersedes multivariate multiple regression models, in which the unknown coefficients are scalar quantities. For the solution, complex numbers are used to rep- resent vector information, and the method of least squares is deployed to estimate the vector model parameters after transforming the complex vector regression model into a real vector regression model through isomorphism. Various operational statistics for testing the predictive significance of the estimated vector parameter coefficients are also derived. A simple numerical example demonstrates the use of the proposed vector regression analysis in modeling typhoon paths.

Impact of polarized e- and e+ beams at a future Linear Collider and a Z-factory Part II - Physics beyond the Standard Model

International Nuclear Information System (INIS)

Moortgat-Pick, G

2011-01-01

Polarization of both beams at a future Linear Collider would be ideal for facing both expected and unforeseen challenges in searches for new physics: fixing the chirality of the couplings and enabling the higher precision for the polarization measurement itself as well as for polarization-dependent observables, it provides a powerful tool for studying new physics at the future Linear Collider, such as discovering new particles, analyzing signals model-independently and resolving precisely the underlying model. Techniques and engineering designs for a polarized-positron source are well advanced. Potential constraints concerning luminosity, commissioning and operating issues appear to be under control. This article mainly treats with the impact of polarized beams on physics beyond the Standard Model, whereas the fundamentals in polarization as well as the gain in electroweak precision physics are summarized in the corresponding part I.

Elliptic-symmetry vector optical fields.

Science.gov (United States)

Pan, Yue; Li, Yongnan; Li, Si-Min; Ren, Zhi-Cheng; Kong, Ling-Jun; Tu, Chenghou; Wang, Hui-Tian

2014-08-11

We present in principle and demonstrate experimentally a new kind of vector fields: elliptic-symmetry vector optical fields. This is a significant development in vector fields, as this breaks the cylindrical symmetry and enriches the family of vector fields. Due to the presence of an additional degrees of freedom, which is the interval between the foci in the elliptic coordinate system, the elliptic-symmetry vector fields are more flexible than the cylindrical vector fields for controlling the spatial structure of polarization and for engineering the focusing fields. The elliptic-symmetry vector fields can find many specific applications from optical trapping to optical machining and so on.

Techniques for vector analyzing power measurements of the sup 2 H(n vector,np)n breakup reaction at low energies

Energy Technology Data Exchange (ETDEWEB)

Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Li Anli; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Naqvi, A.; Walter, R.L. (Duke Univ., Durham, NC (USA) Triangle Universities Nuclear Lab., Durham, NC (USA)); Lambert, J.M.; Treado, P.A. (Georgetown Univ., Washington, DC (USA). Dept. of Physics); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia))

1990-05-10

Experimental methods to measure the vector analyzing powers over a broad range of kinematic configurations in the n-d breakup reaction have been developed at TUNL. These techniques employ the polarized beam facilities at TUNL and use the {sup 2}H(d vector, n vector){sup 3}He reaction as a source of low-energy polarized neutrons. Our methods permit measurements to a high statistical accuracy over a large fraction of three-nucleon phase space. The techniques are described and experimental spectra along with kinematic calculations are presented. (orig.).

Observation of Polarization Vortices in Momentum Space

Science.gov (United States)

Zhang, Yiwen; Chen, Ang; Liu, Wenzhe; Hsu, Chia Wei; Wang, Bo; Guan, Fang; Liu, Xiaohan; Shi, Lei; Lu, Ling; Zi, Jian

2018-05-01

The vortex, a fundamental topological excitation featuring the in-plane winding of a vector field, is important in various areas such as fluid dynamics, liquid crystals, and superconductors. Although commonly existing in nature, vortices were observed exclusively in real space. Here, we experimentally observed momentum-space vortices as the winding of far-field polarization vectors in the first Brillouin zone of periodic plasmonic structures. Using homemade polarization-resolved momentum-space imaging spectroscopy, we mapped out the dispersion, lifetime, and polarization of all radiative states at the visible wavelengths. The momentum-space vortices were experimentally identified by their winding patterns in the polarization-resolved isofrequency contours and their diverging radiative quality factors. Such polarization vortices can exist robustly on any periodic systems of vectorial fields, while they are not captured by the existing topological band theory developed for scalar fields. Our work provides a new way for designing high-Q plasmonic resonances, generating vector beams, and studying topological photonics in the momentum space.

Improved Results for the H-2(d, n)(3) He Transverse Vector Polarization- Transfer Coefficient K-y(y)' (0 degrees) at Low Energies

International Nuclear Information System (INIS)

Roper, C.D.; Clegg, T.; Dunham, J.D.; Mendez, Anthony J. II; Tornow, W.; Walter, R.L.

2010-01-01

Measurements of the H-2(d, n)(3) He transverse vector polarization-transfer coefficient K-y(y)' at 0 degrees. are reported for 29 outgoing neutron energies between 3.94 and 8.47MeV. Our new results determine K-y(y)' (0 degrees) more accurately than previous data, especially for neutron energies below 5MeV. Low-energy data for this reaction are important both as a high-intensity source of highly polarized neutrons for nuclear physics studies with polarized neutron beams, and as a test of the emerging theoretical descriptions of the four-body system, where recently substantial progress has been made.

Validation of SplitVectors Encoding for Quantitative Visualization of Large-Magnitude-Range Vector Fields.

Science.gov (United States)

Henan Zhao; Bryant, Garnett W; Griffin, Wesley; Terrill, Judith E; Jian Chen

2017-06-01

We designed and evaluated SplitVectors, a new vector field display approach to help scientists perform new discrimination tasks on large-magnitude-range scientific data shown in three-dimensional (3D) visualization environments. SplitVectors uses scientific notation to display vector magnitude, thus improving legibility. We present an empirical study comparing the SplitVectors approach with three other approaches - direct linear representation, logarithmic, and text display commonly used in scientific visualizations. Twenty participants performed three domain analysis tasks: reading numerical values (a discrimination task), finding the ratio between values (a discrimination task), and finding the larger of two vectors (a pattern detection task). Participants used both mono and stereo conditions. Our results suggest the following: (1) SplitVectors improve accuracy by about 10 times compared to linear mapping and by four times to logarithmic in discrimination tasks; (2) SplitVectors have no significant differences from the textual display approach, but reduce cluttering in the scene; (3) SplitVectors and textual display are less sensitive to data scale than linear and logarithmic approaches; (4) using logarithmic can be problematic as participants' confidence was as high as directly reading from the textual display, but their accuracy was poor; and (5) Stereoscopy improved performance, especially in more challenging discrimination tasks.

PROPERTIES OF INTERSTELLAR TURBULENCE FROM GRADIENTS OF LINEAR POLARIZATION MAPS

International Nuclear Information System (INIS)

Burkhart, Blakesley; Lazarian, A.; Gaensler, B. M.

2012-01-01

Faraday rotation of linearly polarized radio signals provides a very sensitive probe of fluctuations in the interstellar magnetic field and ionized gas density resulting from magnetohydrodynamic (MHD) turbulence. We used a set of statistical tools to analyze images of the spatial gradient of linearly polarized radio emission (|∇P|) for both observational data from a test image of the Southern Galactic Plane Survey (SGPS) and isothermal three-dimensional simulations of MHD turbulence. Visually, in both observations and simulations, a complex network of filamentary structures is seen. Our analysis shows that the filaments in |∇P| can be produced both by interacting shocks and random fluctuations characterizing the non-differentiable field of MHD turbulence. The latter dominates for subsonic turbulence, while the former is only present in supersonic turbulence. We show that supersonic and subsonic turbulence exhibit different distributions as well as different morphologies in the maps of |∇P|. Particularly, filaments produced by shocks show a characteristic 'double jump' profile at the sites of shock fronts resulting from delta function-like increases in the density and/or magnetic field, while those produced by subsonic turbulence show a single jump profile. In order to quantitatively characterize these differences, we use the topology tool known as the genus curve as well as the probability distribution function moments of the image distribution. We find that higher values for the moments correspond to cases of |∇P| with larger sonic Mach numbers. The genus analysis of the supersonic simulations of |∇P| reveals a 'swiss cheese' topology, while the subsonic cases have characteristics of a 'clump' topology. Based on the analysis of the genus and the higher order moments, the SGPS test region data have a distribution and morphology that match subsonic- to transonic-type turbulence, which confirms what is now expected for the warm ionized medium.

PROPERTIES OF INTERSTELLAR TURBULENCE FROM GRADIENTS OF LINEAR POLARIZATION MAPS

Energy Technology Data Exchange (ETDEWEB)

Burkhart, Blakesley; Lazarian, A. [Astronomy Department, University of Wisconsin, Madison, 475 N. Charter St., WI 53711 (United States); Gaensler, B. M. [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)

2012-04-20

Faraday rotation of linearly polarized radio signals provides a very sensitive probe of fluctuations in the interstellar magnetic field and ionized gas density resulting from magnetohydrodynamic (MHD) turbulence. We used a set of statistical tools to analyze images of the spatial gradient of linearly polarized radio emission (|{nabla}P|) for both observational data from a test image of the Southern Galactic Plane Survey (SGPS) and isothermal three-dimensional simulations of MHD turbulence. Visually, in both observations and simulations, a complex network of filamentary structures is seen. Our analysis shows that the filaments in |{nabla}P| can be produced both by interacting shocks and random fluctuations characterizing the non-differentiable field of MHD turbulence. The latter dominates for subsonic turbulence, while the former is only present in supersonic turbulence. We show that supersonic and subsonic turbulence exhibit different distributions as well as different morphologies in the maps of |{nabla}P|. Particularly, filaments produced by shocks show a characteristic 'double jump' profile at the sites of shock fronts resulting from delta function-like increases in the density and/or magnetic field, while those produced by subsonic turbulence show a single jump profile. In order to quantitatively characterize these differences, we use the topology tool known as the genus curve as well as the probability distribution function moments of the image distribution. We find that higher values for the moments correspond to cases of |{nabla}P| with larger sonic Mach numbers. The genus analysis of the supersonic simulations of |{nabla}P| reveals a 'swiss cheese' topology, while the subsonic cases have characteristics of a 'clump' topology. Based on the analysis of the genus and the higher order moments, the SGPS test region data have a distribution and morphology that match subsonic- to transonic-type turbulence, which confirms what is now

Linearly polarized photoluminescence of anisotropically strained c-plane GaN layers on stripe-shaped cavity-engineered sapphire substrate

Science.gov (United States)

Kim, Jongmyeong; Moon, Daeyoung; Lee, Seungmin; Lee, Donghyun; Yang, Duyoung; Jang, Jeonghwan; Park, Yongjo; Yoon, Euijoon

2018-05-01

Anisotropic in-plane strain and resultant linearly polarized photoluminescence (PL) of c-plane GaN layers were realized by using a stripe-shaped cavity-engineered sapphire substrate (SCES). High resolution X-ray reciprocal space mapping measurements revealed that the GaN layers on the SCES were under significant anisotropic in-plane strain of -0.0140% and -0.1351% along the directions perpendicular and parallel to the stripe pattern, respectively. The anisotropic in-plane strain in the GaN layers was attributed to the anisotropic strain relaxation due to the anisotropic arrangement of cavity-incorporated membranes. Linearly polarized PL behavior such as the observed angle-dependent shift in PL peak position and intensity comparable with the calculated value based on k.p perturbation theory. It was found that the polarized PL behavior was attributed to the modification of valence band structures induced by anisotropic in-plane strain in the GaN layers on the SCES.

Financial Distress Prediction using Linear Discriminant Analysis and Support Vector Machine

Science.gov (United States)

Santoso, Noviyanti; Wibowo, Wahyu

2018-03-01

A financial difficulty is the early stages before the bankruptcy. Bankruptcies caused by the financial distress can be seen from the financial statements of the company. The ability to predict financial distress became an important research topic because it can provide early warning for the company. In addition, predicting financial distress is also beneficial for investors and creditors. This research will be made the prediction model of financial distress at industrial companies in Indonesia by comparing the performance of Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) combined with variable selection technique. The result of this research is prediction model based on hybrid Stepwise-SVM obtains better balance among fitting ability, generalization ability and model stability than the other models.

Modulated molecular beam mass spectrometry: A generalized expression for the ''reaction product vector'' for linear systems

International Nuclear Information System (INIS)

Chang, H.; Weinberg, W.H.

1977-01-01

A generalized expression is developed that relates the ''reaction product vector'', epsilon exp(-iphi), to the kinetic parameters of a linear system. The formalism is appropriate for the analysis of modulated molecular beam mass spectrometry data and facilitates the correlation of experimental results to (proposed) linear models. A study of stability criteria appropriate for modulated molecular beam mass spectrometry experiments is also presented. This investigation has led to interesting inherent limitations which have not heretofore been emphasized, as well as a delineation of the conditions under which stable chemical oscillations may occur in the reacting system

SUBMILLIMETER POLARIZATION OBSERVATION OF THE PROTOPLANETARY DISK AROUND HD 142527

Energy Technology Data Exchange (ETDEWEB)

Kataoka, Akimasa; Dullemond, Cornelis P.; Pohl, Adriana [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Tsukagoshi, Takashi; Momose, Munetake [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Nagai, Hiroshi [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Muto, Takayuki [Division of Liberal Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Fukagawa, Misato [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Shibai, Hiroshi [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Hanawa, Tomoyuki [Center for Frontier Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522 (Japan); Murakawa, Koji, E-mail: kataoka@uni-heidelberg.de [College of General Education, Osaka Sangyo University, 3-1-1, Nakagaito, Daito, Osaka 574-8530 (Japan)

2016-11-10

We present the polarization observations toward the circumstellar disk around HD 142527 by using Atacama Large Millimeter/submillimeter Array at the frequency of 343 GHz. The beam size is 0.″51 × 0.″44, which corresponds to the spatial resolution of ∼71 × 62 au. The polarized intensity displays a ring-like structure with a peak located on the east side with a polarization fraction of P = 3.26 ± 0.02%, which is different from the peak of the continuum emission from the northeast region. The polarized intensity is significantly weaker at the peak of the continuum where P = 0.220 ± 0.010%. The polarization vectors are in the radial direction in the main ring of the polarized intensity, while there are two regions outside at the northwest and northeast areas where the vectors are in the azimuthal direction. If the polarization vectors represent the magnetic field morphology, the polarization vectors indicate the toroidal magnetic field configuration on the main ring and the poloidal fields outside. On the other hand, the flip of the polarization vectors is predicted by the self-scattering of thermal dust emission due to the change of the direction of thermal radiation flux. Therefore, we conclude that self-scattering of thermal dust emission plays a major role in producing polarization at millimeter wavelengths in this protoplanetary disk. Also, this puts a constraint on the maximum grain size to be approximately 150 μ m if we assume compact spherical dust grains.

Vector geometry

CERN Document Server

Robinson, Gilbert de B

2011-01-01

This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom

Polarized Uniform Linear Array System: Beam Radiation Pattern, Beamforming Diversity Order, and Channel Capacity

Directory of Open Access Journals (Sweden)

Xin Su

2015-01-01

Full Text Available There have been many studies regarding antenna polarization; however, there have been few publications on the analysis of the channel capacity for polarized antenna systems using the beamforming technique. According to Chung et al., the channel capacity is determined by the density of scatterers and the transmission power, which is obtained based on the assumption that scatterers are uniformly distributed on a 3D spherical scattering model. However, it contradicts the practical scenario, where scatterers may not be uniformly distributed under outdoor environment, and lacks the consideration of fading channel gain. In this study, we derive the channel capacity of polarized uniform linear array (PULA systems using the beamforming technique in a practical scattering environment. The results show that, for PULA systems, the channel capacity, which is boosted by beamforming diversity, can be determined using the channel gain, beam radiation pattern, and beamforming diversity order (BDO, where the BDO is dependent on the antenna characteristics and array configurations.

Unique heavy lepton signature at e{sup +}e{sup -} linear collider with polarized beams

Energy Technology Data Exchange (ETDEWEB)

Moortgat-Pick, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Osland, P. [Univ. Bergen (Norway). Dept. of Physics and Technology; Pankov, A.A.; Tsytrinov, A.V. [Technical Univ. Gomel (Belarus). Abdus Salam ICTP Affliated Centre

2013-03-15

We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e{sup +}e{sup -}{yields}W{sup +}W{sup -} within E{sub 6} models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton exchange from Z-Z' mixing within the same class of models and also from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to very similar experimental signatures at the e{sup +}e{sup -} International Linear Collider (ILC) for {radical}(s)=350, 500 GeV and 1 TeV. Such clear identification of the model is possible by using a certain double polarization asymmetry. The availability of both beams being polarized plays a crucial role in identifying such exotic-lepton admixture. In addition, the sensitivity of the ILC for probing exotic-lepton admixture is substantially enhanced when the polarization of the produced W{sup {+-}} bosons is considered.

Linear versus circular polarization of head coils - comparison on phantom and in the clinic

International Nuclear Information System (INIS)

Schratter, M.; Kramer, J.; Prayer, L.; Wimberger, D.; Imhof, H.; Schmid, W.

1990-01-01

Two different head coils - one with linear polarization and the other with circular polarization - were compared under the same measurement conditions. Comparison was done on a phantom with waterfilled and gadolinium-filled pin-holes, as well as on anatomical MR images of 23 volunteers. In three volunteers the whole brain was examined while, in the remaining 20 volunteers the sella region or cerebellopontine angleregion was examined. Criteria for comparison were signal-to-noise ratio, background noise, and detail resolution (phantom), as well as subjective criteria - image sharpness, anatomical, contrast, and recognition of anatomical details -, evaluated on anatomical MR images by four radiologists independently of each other. The results show a significant improvement of signal-to-noise ratio, lower background noise and therefore marked improvement of images harpness, and moderate improvement in the recognition of anatomical details using the circular polarized head coil; as for as detail resolution and anatomical contrast were concerned, however, no significant difference was seen between the two coils. Major advantages of the circular, polarized head coil in clinical application are shorter measurement times (reduced number of acquisitions), as well as thinner slices without loss of signal-to-noise ratio. (orig.) [de

Polarization Measurements in Neutral Pion Photoproduction

International Nuclear Information System (INIS)

C. Jones; Krishni Wijesooriya; B. Fox; Andrei Afanasev; Moscov Amaryan; Konrad Aniol; Stephen Becher; Kamal Benslama; Louis Bimbot; Peter Bosted; Edward Brash; John Calarco; Zhengwei Chai; C. Chang; Ting Chang; Jian-Ping Chen; Seonho Choi; Eugene Chudakov; Steve Churchwell; Domenick Crovelli; Sonja Dieterich; Scott Dumalski; Dipangkar Dutta; Martin Epstein; Kevin Fissum; Salvatore Frullani; Haiyan Gao; Juncai Gao; Franco Garibaldi; Olivier Gayou; Ronald Gilman; Oleksandr Glamazdin; Charles Glashausser; Javier Gomez; Viktor Gorbenko; Ole Hansen; Roy Holt; Jordan Hovdebo; Garth Huber; Kees de Jager; Xiaodong Jiang; Mark Jones; Jim Kelly; Edward Kinney; Edgar Kooijman; Gerfried Kumbartzki; Michael Kuss; John LeRose; Meme Liang; Richard Lindgren; Nilanga Liyanage; Sergey Malov; Demetrius Margaziotis; Pete Markowitz; Kathy McCormick; Dave Meekins; Zein-Eddine Meziani; Robert Michaels; Joe Mitchell; Ludyvine Morand; Charles Perdrisat

2002-01-01

We present measurements of the recoil proton polarization for the 1 H(gamma-vector,p-vector)pi 0 reaction for theta c.m. pi = 60 o -135 o and for photon energies up to 4.1 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. Various theoretical models are compared with the results. No evidence for hadron helicity conservation is observed. Models that employ factorization are not favored. It appears from the strong angular dependence of the induced polarization at photon energies of 2.5 and 3.1 GeV that a relatively high spin resonance or background amplitude might exist in this energy region

Localization of periodic orbits of polynomial vector fields of even degree by linear functions

Energy Technology Data Exchange (ETDEWEB)

Starkov, Konstantin E. [CITEDI-IPN, Av. del Parque 1310, Mesa de Otay, Tijuana, BC (Mexico)] e-mail: konst@citedi.mx

2005-08-01

This paper is concerned with the localization problem of periodic orbits of polynomial vector fields of even degree by using linear functions. Conditions of the localization of all periodic orbits in sets of a simple structure are obtained. Our results are based on the solution of the conditional extremum problem and the application of homogeneous polynomial forms of even degrees. As examples, the Lanford system, the jerky system with one quadratic monomial and a quartically perturbed harmonic oscillator are considered.

Localization of periodic orbits of polynomial vector fields of even degree by linear functions

International Nuclear Information System (INIS)

Starkov, Konstantin E.

2005-01-01

This paper is concerned with the localization problem of periodic orbits of polynomial vector fields of even degree by using linear functions. Conditions of the localization of all periodic orbits in sets of a simple structure are obtained. Our results are based on the solution of the conditional extremum problem and the application of homogeneous polynomial forms of even degrees. As examples, the Lanford system, the jerky system with one quadratic monomial and a quartically perturbed harmonic oscillator are considered

The Weizsäcker-Williams distribution of linearly polarized gluons (and its fluctuations) at small x

Energy Technology Data Exchange (ETDEWEB)

Dumitru, Adrian; Skokov, Vladimir

2017-09-11

The conventional and linearly polarized Weizsäcker-Williams gluon distributions at small x are defined from the two-point function of the gluon field in light-cone gauge. They appear in the cross section for dijet production in deep inelastic scattering at high energy. We determine these functions in the small-x limit from solutions of the JIMWLK evolution equations and show that they exhibit approximate geometric scaling. Also, we discuss the functional distributions of these WW gluon distributions over the JIMWLK ensemble at rapidity Y ~ 1/αs. These are determined by a 2d Liouville action for the logarithm of the covariant gauge function g2tr A+(q)A+(-q). For transverse momenta on the order of the saturation scale we observe large variations across configurations (evolution trajectories) of the linearly polarized distribution up to several times its average, and even to negative values.

Polarized object detection in crabs: a two-channel system.

Science.gov (United States)

Basnak, Melanie Ailín; Pérez-Schuster, Verónica; Hermitte, Gabriela; Berón de Astrada, Martín

2018-05-25

Many animal species take advantage of polarization vision for vital tasks such as orientation, communication and contrast enhancement. Previous studies have suggested that decapod crustaceans use a two-channel polarization system for contrast enhancement. Here, we characterize the polarization contrast sensitivity in a grapsid crab . We estimated the polarization contrast sensitivity of the animals by quantifying both their escape response and changes in heart rate when presented with polarized motion stimuli. The motion stimulus consisted of an expanding disk with an 82 deg polarization difference between the object and the background. More than 90% of animals responded by freezing or trying to avoid the polarized stimulus. In addition, we co-rotated the electric vector (e-vector) orientation of the light from the object and background by increments of 30 deg and found that the animals' escape response varied periodically with a 90 deg period. Maximum escape responses were obtained for object and background e-vectors near the vertical and horizontal orientations. Changes in cardiac response showed parallel results but also a minimum response when e-vectors of object and background were shifted by 45 deg with respect to the maxima. These results are consistent with an orthogonal receptor arrangement for the detection of polarized light, in which two channels are aligned with the vertical and horizontal orientations. It has been hypothesized that animals with object-based polarization vision rely on a two-channel detection system analogous to that of color processing in dichromats. Our results, obtained by systematically varying the e-vectors of object and background, provide strong empirical support for this theoretical model of polarized object detection. © 2018. Published by The Company of Biologists Ltd.

Dual comb generation from a mode-locked fiber laser with orthogonally polarized interlaced pulses.

Science.gov (United States)

Akosman, Ahmet E; Sander, Michelle Y

2017-08-07

Ultra-high precision dual-comb spectroscopy traditionally requires two mode-locked, fully stabilized lasers with complex feedback electronics. We present a novel mode-locked operation regime in a thulium-holmium co-doped fiber laser, a frequency-halved state with orthogonally polarized interlaced pulses, for dual comb generation from a single source. In a linear fiber laser cavity, an ultrafast pulse train composed of co-generated, equal intensity and orthogonally polarized consecutive pulses at half of the fundamental repetition rate is demonstrated based on vector solitons. Upon optical interference of the orthogonally polarized pulse trains, two stable microwave RF beat combs are formed, effectively down-converting the optical properties into the microwave regime. These co-generated, dual polarization interlaced pulse trains, from one all-fiber laser configuration with common mode suppression, thus provide an attractive compact source for dual-comb spectroscopy, optical metrology and polarization entanglement measurements.

Production of polarized negative deuterium ion beam with dual optical pumping in KEK

Energy Technology Data Exchange (ETDEWEB)

Kinsho, M.; Ikegami, K.; Takagi, A. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Mori, Y.

1997-02-01

To obtain highly nuclear-spin vector polarized negative deuterium ion beam, a dual optically pumped polarized negative deuterium ion source has been developed at KEK. It is possible to select a pure nuclear-spin state with this scheme, and negative deuterium ion beam with 100% nuclear-spin vector polarization can be produced in principle. We have obtained about 70% of nuclear-spin vector polarized negative deuterium ion beam so far. This result may open up a new possibilities for the optically pumped polarized ion source. (author)

Experimental investigation of the effect of the laser beam polarization state on the quality of steel sheet cutting

Science.gov (United States)

Golyshev, A. A.; Orishich, A. M.; Shulyatyev, V. B.

2017-10-01

The paper presents the results of experimental investigation of the effect of the beam polarization on the quality of the oxygen-assisted laser cutting of steel by a CO2-laser. Under consideration is the effect of the laser cutting parameters by the beam with the linear polarization on the cut surface roughness. It is founded that the minimal roughness is reached when the electric field vector is perpendicular to the cutting speed vector. It is concluded that the absorbed power distribution imposes the essential influence on the surface quality, and that the radiation heating of side walls is important to have lower roughness. Obtained results enabled to present probable reasons of the worse surface quality of the metals cut by a fiber laser than the ones cut by a CO2-laser.

Improved linearity in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors with nonlinear polarization dielectric

International Nuclear Information System (INIS)

Gao, Tao; Xu, Ruimin; Kong, Yuechan; Zhou, Jianjun; Kong, Cen; Dong, Xun; Chen, Tangsheng

2015-01-01

We demonstrate highly improved linearity in a nonlinear ferroelectric of Pb(Zr 0.52 Ti 0.48 )-gated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). Distinct double-hump feature in the transconductance-gate voltage (g m -V g ) curve is observed, yielding remarkable enhancement in gate voltage swing as compared to MIS-HEMT with conventional linear gate dielectric. By incorporating the ferroelectric polarization into a self-consistent calculation, it is disclosed that in addition to the common hump corresponding to the onset of electron accumulation, the second hump at high current level is originated from the nonlinear polar nature of ferroelectric, which enhances the gate capacitance by increasing equivalent dielectric constant nonlinearly. This work paves a way for design of high linearity GaN MIS-HEMT by exploiting the nonlinear properties of dielectric

Output-only modal parameter estimator of linear time-varying structural systems based on vector TAR model and least squares support vector machine

Science.gov (United States)

Zhou, Si-Da; Ma, Yuan-Chen; Liu, Li; Kang, Jie; Ma, Zhi-Sai; Yu, Lei

2018-01-01

Identification of time-varying modal parameters contributes to the structural health monitoring, fault detection, vibration control, etc. of the operational time-varying structural systems. However, it is a challenging task because there is not more information for the identification of the time-varying systems than that of the time-invariant systems. This paper presents a vector time-dependent autoregressive model and least squares support vector machine based modal parameter estimator for linear time-varying structural systems in case of output-only measurements. To reduce the computational cost, a Wendland's compactly supported radial basis function is used to achieve the sparsity of the Gram matrix. A Gamma-test-based non-parametric approach of selecting the regularization factor is adapted for the proposed estimator to replace the time-consuming n-fold cross validation. A series of numerical examples have illustrated the advantages of the proposed modal parameter estimator on the suppression of the overestimate and the short data. A laboratory experiment has further validated the proposed estimator.

Optical cage generated by azimuthal- and radial-variant vector beams.

Science.gov (United States)

Man, Zhongsheng; Bai, Zhidong; Li, Jinjian; Zhang, Shuoshuo; Li, Xiaoyu; Zhang, Yuquan; Ge, Xiaolu; Fu, Shenggui

2018-05-01

We propose a method to generate an optical cage using azimuthal- and radial-variant vector beams in a high numerical aperture optical system. A new kind of vector beam that has azimuthal- and radial-variant polarization states is proposed and demonstrated theoretically. Then, an integrated analytical model to calculate the electromagnetic field and Poynting vector distributions of the input azimuthal- and radial-variant vector beams is derived and built based on the vector diffraction theory of Richards and Wolf. From calculations, a full polarization-controlled optical cage is obtained by simply tailoring the radial index of the polarization, the uniformity U of which is up to 0.7748, and the cleanness C is zero. Additionally, a perfect optical cage can be achieved with U=1, and C=0 by introducing an amplitude modulation; its magnetic field and energy flow are also demonstrated in detail. Such optical cages may be helpful in applications such as optical trapping and high-resolution imaging.

Polarization extinction ratio of the polarization crosstalk caused by point pressure force in the polarization-maintaining fiber

Science.gov (United States)

Mukhtubayev, Azamat B.; Aksarin, Stanislav M.; Strigalev, Vladimir E.

2017-11-01

A study of the orthogonal polarization modes crosstalk changes in the point of different mechanical actions (pressure force) in the polarization-maintaining fiber with straining elliptical cladding is presented. It was found that by increasing of the pressure force the polarization extinction ratio increases nonlinearly. Also revealed the dependence of the extinction coefficient and the angle between vector of the mechanical action and polarization axes of the test fiber, which leads to change the extinction coefficient variable from -57 dB to -25 dB under the pressure force of 0.7 N. Also it was found that the cross angle of the fiber axes doesn't influence on the extinction ratio value of the mechanical induced polarization crosstalk.

Analysis of the collagen birefringence and the relative attenuation coefficient of health and burned skin irradiated with linearly polarized He-Ne laser

International Nuclear Information System (INIS)

Silva, Daniela de Fatima Teixeira da

2002-01-01

Low-intensity laser therapy is characterized by its ability to induce athermic effects and nondestructive photobiological processes. Although it has been in use for more than 40 years, this phototherapy is still not an established therapeutic modality. The objectives of this study were: to quantify the collagen fibers organization by polarized light microscopy in normal and burned skin samples at day 17 post-injury considering preferential axis as the animal's spinal column and aligning the linear laser polarization in two directions of polarization, parallel or perpendicular to this axis; to determine the relative attenuation coefficient for the intensity light by the technique of imaging the light distribution in normal and burned skin during wound healing process taking only parallel direction of polarization. To reach the objectives, burns about 6 mm in diameter were created with liquid N 2 on the back of the rats and the lesions were irradiated on days 3, 7, 10 and 14 post-wounding, D= 1 J/cm 2 , to investigate the effects of low-intensity linearly polarized He-Ne laser beam on skin wounds healing. Control lesions were not irradiated. The results have demonstrated that: the skin samples irradiated with linearly parallel polarized He-Ne laser beam showed collagen fibers more organized; burned skin samples presents a higher attenuation coefficient than normal skin samples. These results are important to optimize low intensity laser therapy dosimetry on acceleration wound healing. (author)

Polarized deuteron elastic scattering from a polarized proton target

International Nuclear Information System (INIS)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R.; Zankel, H.

1983-01-01

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76 0 ,85 0 ,98 0 ,115 0 ,132 0 ). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results. (orig.)

First measurement of the helicity-dependent (vector)({gamma})(vector)(p){yields}p{eta} differential cross-section

Energy Technology Data Exchange (ETDEWEB)

Ahrens, J.; Arends, H.J.; Aulenbacher, K.; Beck, R.; Drechsel, D.; Harrach, D. van; Heid, E. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Altieri, S. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, I-27100 Pavia (Italy); Annand, J.R.M. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Anton, G. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Bradtke, C.; Goertz, S.; Harmsen, J. [Institut fuer Experimentalphysik, Ruhr-Universitaet Bochum, D-44801 Bochum (Germany); Braghieri, A. [INFN, Sezione di Pavia, I-27100 Pavia (Italy); d' Hose, N. [CEA Saclay, DSM/DAPNIA/SPhN, F-91191 Gif-sur-Yvette Cedex (France); Dutz, H. [Physikalisches Institut, Universitaet Bonn, D-53115 Bonn (Germany); Grabmayr, P. [Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen (Germany); Hansen, K. [Department of Physics, University of Lund, Lund (Sweden); Hasegawa, S. [Department of Physics, Nagoya University, Chikusa-ku, Nagoya (Japan); Hasegawa, T. [Faculty of Engineering, Miyazaki University, Miyazaki (Japan); Helbing, K.; Holvoet, H.; Van Hoorebeke, L.; Horikawa, N.; Iwata, T.; Jahn, O.; Jennewein, P.; Kageya, T.; Kiel, B.; Klein, F.; Kondratiev, R.; Kossert, K.; Krimmer, J.; Lang, M.; Lannoy, B.; Leukel, R.; Lisin, V.; Matsuda, T.; McGeorge, J.C.; Meier, A.; Menze, D.; Meyer, W.; Michel, T.; Naumann, J.; Panzeri, A.; Pedroni, P.; Pinelli, T.; Preobrajenski, I.; Radtke, E.; Reichert, E.; Reicherz, G.; Rohlof, Ch.; Rosner, G.; Ryckbosch, D.; Sauer, M.; Schoch, B.; Schumacher, M.; Seitz, B.; Speckner, T.; Takabayashi, N.; Tamas, G.; Thomas, A.; Van de Vyver, R.; Wakai, A.; Weihofen, W.; Wissmann, F.; Zapadtka, F.; Zeitler, G.

2003-06-01

The helicity dependence of the (vector)({gamma})(vector)(p){yields}p{eta} reaction has been measured for the first time at a center-of-mass angle {theta}{sup *}{sub {eta}}=70 in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4{pi}-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis. (orig.)

A Design Of Feeding Network For A Dual-Linear Polarization, Stacked, Probe-Fed Microstrip Patch Antenna Array

DEFF Research Database (Denmark)

Jaworski, G.; Krozer, Viktor

2004-01-01

Components of multilayer feed network are presented for application in broad-band dual-linear polarized stacked C-band antenna. Measurement results of wide band matching circuits and different types of power divider networks constituting parts of BFN demonstrate wideband operation. Suitable...

Polarized Photocathode R&D for Future Linear Collliders

Energy Technology Data Exchange (ETDEWEB)

Zhou, F; Brachmann, A.; Maruyama, T.; Sheppard, J.C.; /SLAC

2009-01-23

It is a challenge to generate full charge electrons from the electron sources without compromising polarization for the proposed ILC and CLIC. It is essential to advance polarized photocathodes to meet the requirements. SLAC has worldwide unique dedicated test facilities, Cathode Test System and dc-Gun Test Laboratory, to fully characterize polarized photocathodes. Recent systematic measurements on a strained-well InAlGaAs/AlGaAs cathode at the facilities show that 87% polarization and 0.3% QE are achieved. The QE can be increased to {approx}1.0% with atomic hydrogen cleaning. The surface charge limit at a very low current intensity and the clear dependence of the polarization on the surface charge limit are observed for the first time. On-going programs to develop photocathodes for the ILC and CLIC are briefly introduced.

Improved linearity in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors with nonlinear polarization dielectric

Energy Technology Data Exchange (ETDEWEB)

Gao, Tao [Fundamental Science on EHF Laboratory, University of Electronic Science and Technology of China (UESTC), Chengdu 611731 (China); Science and Technology on Monolithic Integrated Circuits and Modules Laboratory, Nanjing Electronic Devices Institute, Nanjing 210016 (China); Xu, Ruimin [Fundamental Science on EHF Laboratory, University of Electronic Science and Technology of China (UESTC), Chengdu 611731 (China); Kong, Yuechan, E-mail: kycfly@163.com; Zhou, Jianjun; Kong, Cen; Dong, Xun; Chen, Tangsheng [Science and Technology on Monolithic Integrated Circuits and Modules Laboratory, Nanjing Electronic Devices Institute, Nanjing 210016 (China)

2015-06-15

We demonstrate highly improved linearity in a nonlinear ferroelectric of Pb(Zr{sub 0.52}Ti{sub 0.48})-gated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). Distinct double-hump feature in the transconductance-gate voltage (g{sub m}-V{sub g}) curve is observed, yielding remarkable enhancement in gate voltage swing as compared to MIS-HEMT with conventional linear gate dielectric. By incorporating the ferroelectric polarization into a self-consistent calculation, it is disclosed that in addition to the common hump corresponding to the onset of electron accumulation, the second hump at high current level is originated from the nonlinear polar nature of ferroelectric, which enhances the gate capacitance by increasing equivalent dielectric constant nonlinearly. This work paves a way for design of high linearity GaN MIS-HEMT by exploiting the nonlinear properties of dielectric.

Polarization variablity among Wolf-Rayet stars. IV. A complete lack of circular polarization in the optical continuum

International Nuclear Information System (INIS)

Robert, C.; Moffat, A.F.J.

1989-01-01

Quasi-simultaneous blue and red, broadband optical monitoring in linear and circular polarization and in intensity has been carried out over an interval of three weeks for several Wolf-Rayet stars that show relatively large Delta P variations in linear polarization. No significant varying Delta V component of circular polarization is detected in any of these stars. The lower upper limit Delta V/Delta P implies that the intrinsic linearly polarized light which does vary cannot be produced by electrons gyrating in a magnetic field, unless they are ultrarelativistic - a rather unlikely situation. The low mean circular polarization typically observed is probably interstellar in origin. Lack of periodicity in the observed variations of linear polarization implies that even weak magnetic field loops are unlikely to be involved in confining pockets of wind plasma. The observed linear polarization variations are related mainly to electron scattering. 25 refs

Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

Science.gov (United States)

Van Delden, Jay S

2003-07-15

A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

The ratio R = dσL/dσT in heavy-quark pair leptoproduction as a probe of linearly polarized gluons in unpolarized proton

Science.gov (United States)

Efremov, A. V.; Ivanov, N. Ya.; Teryaev, O. V.

2018-05-01

We study the Callan-Gross ratio R = dσL / dσT in heavy-quark pair leptoproduction, lN →l‧ Q Q bar X, as a probe of linearly polarized gluons inside unpolarized proton, where dσT (dσL) is the differential cross section of the γ* N → Q Q bar X process initiated by a transverse (longitudinal) virtual photon. Note first that the maximal value for the quantity R allowed by the photon-gluon fusion with unpolarized gluons is large, about 2. We calculate the contribution of the transverse-momentum dependent gluonic counterpart of the Boer-Mulders function, h1 ⊥g , describing the linear polarization of gluons inside unpolarized proton. Our analysis shows that the maximum value of the ratio R depends strongly on the gluon polarization; it varies from 0 to Q2/4m2 depending on h1⊥g . We conclude that the Callan-Gross ratio in heavy-quark pair leptoproduction is predicted to be large and very sensitive to the contribution of linearly polarized gluons. For this reason, future measurements of the longitudinal and transverse components of the charm and bottom production cross sections at the proposed EIC and LHeC colliders seem to be very promising for determination of the linear polarization of gluons inside unpolarized proton.

QSAR models for prediction study of HIV protease inhibitors using support vector machines, neural networks and multiple linear regression

Directory of Open Access Journals (Sweden)

Rachid Darnag

2017-02-01

Full Text Available Support vector machines (SVM represent one of the most promising Machine Learning (ML tools that can be applied to develop a predictive quantitative structure–activity relationship (QSAR models using molecular descriptors. Multiple linear regression (MLR and artificial neural networks (ANNs were also utilized to construct quantitative linear and non linear models to compare with the results obtained by SVM. The prediction results are in good agreement with the experimental value of HIV activity; also, the results reveal the superiority of the SVM over MLR and ANN model. The contribution of each descriptor to the structure–activity relationships was evaluated.

Statistics of a parallel Poynting vector in the auroral zone as a function of altitude using Polar EFI and MFE data and Astrid-2 EMMA data

Directory of Open Access Journals (Sweden)

P. Janhunen

2005-07-01

Full Text Available We study the wave-related (AC and static (DC parallel Poynting vector (Poynting energy flux as a function of altitude in auroral field lines using Polar EFI and MFE data. The study is statistical and contains 5 years of data in the altitude range 5000–30000 km. We verify the low altitude part of the results by comparison with earlier Astrid-2 EMMA Poynting vector statistics at 1000 km altitude. The EMMA data are also used to statistically compensate the Polar results for the missing zonal electric field component. We compare the Poynting vector with previous statistical DMSP satellite data concerning the electron precipitation power. We find that the AC Poynting vector (Alfvén-wave related Poynting vector is statistically not sufficient to power auroral electron precipitation, although it may, for K_p>2, power 25–50% of it. The statistical AC Poynting vector also has a stepwise transition at R=4 R_E, so that its amplitude increases with increasing altitude. We suggest that this corresponds to Alfvén waves being in Landau resonance with electrons, so that wave-induced electron acceleration takes place at this altitude range, which was earlier named the Alfvén Resonosphere (ARS. The DC Poynting vector is ~3 times larger than electron precipitation and corresponds mainly to ionospheric Joule heating. In the morning sector (02:00–06:00 MLT we find that the DC Poynting vector has a nontrivial altitude profile such that it decreases by a factor of ~2 when moving upward from 3 to 4 R_E radial distance. In other nightside MLT sectors the altitude profile is more uniform. The morning sector nontrivial altitude profile may be due to divergence of the perpendicular Poynting vector field at R=3–4 R_E.

Keywords. Magnetospheric physics (Auroral phenomena; Magnetosphere-ionosphere interactions – Space plasma physics (Wave-particle interactions

Statistics of a parallel Poynting vector in the auroral zone as a function of altitude using Polar EFI and MFE data and Astrid-2 EMMA data

Directory of Open Access Journals (Sweden)

P. Janhunen

2005-07-01

Full Text Available We study the wave-related (AC and static (DC parallel Poynting vector (Poynting energy flux as a function of altitude in auroral field lines using Polar EFI and MFE data. The study is statistical and contains 5 years of data in the altitude range 5000–30000 km. We verify the low altitude part of the results by comparison with earlier Astrid-2 EMMA Poynting vector statistics at 1000 km altitude. The EMMA data are also used to statistically compensate the Polar results for the missing zonal electric field component. We compare the Poynting vector with previous statistical DMSP satellite data concerning the electron precipitation power. We find that the AC Poynting vector (Alfvén-wave related Poynting vector is statistically not sufficient to power auroral electron precipitation, although it may, for Kp>2, power 25–50% of it. The statistical AC Poynting vector also has a stepwise transition at R=4 RE, so that its amplitude increases with increasing altitude. We suggest that this corresponds to Alfvén waves being in Landau resonance with electrons, so that wave-induced electron acceleration takes place at this altitude range, which was earlier named the Alfvén Resonosphere (ARS. The DC Poynting vector is ~3 times larger than electron precipitation and corresponds mainly to ionospheric Joule heating. In the morning sector (02:00–06:00 MLT we find that the DC Poynting vector has a nontrivial altitude profile such that it decreases by a factor of ~2 when moving upward from 3 to 4 RE radial distance. In other nightside MLT sectors the altitude profile is more uniform. The morning sector nontrivial altitude profile may be due to divergence of the perpendicular Poynting vector field at R=3–4 RE. Keywords. Magnetospheric physics (Auroral phenomena; Magnetosphere-ionosphere interactions – Space plasma physics (Wave-particle interactions

Linear Algebra and Smarandache Linear Algebra

OpenAIRE

Vasantha, Kandasamy

2003-01-01

The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and vector spaces over finite p...

Electroweak coupling measurements from polarized Bhabha scattering at the Z{sup 0} resonance

Energy Technology Data Exchange (ETDEWEB)

Pitts, K.T.

1994-03-01

The cross section for Bhabha scattering (e{sup +}e{sup {minus}} {yields} e{sup +}e{sup {minus}}) with polarized electrons at the center of mass energy of the Z{sup 0} resonance has been measured with the SLD experiment at the Stanford Linear Accelerator Center during the 1992 and 1993 runs. The electroweak couplings of the electron are extracted. At small angles the measurement is done in the SLD Silicon/Tungsten Luminosity Monitor (LMSAT). A detailed description of the design, construction, commissioning and operation of the LMSAT is provided. The integrated luminosity for 1992 is measured to be L = 420.86{plus_minus}2.56 (stat){plus_minus}4.23 (sys) nb{sup {minus}1}. The luminosity asymmetry for polarized beams is measured to be A{sub LR}(LUM) = (1.7 {plus_minus} 6.4) {times} 10{sup {minus}3}. The large angle polarized Bhabha scattering reveals the effective electron vector and axial vector couplings to the Z{sup 0} through the measurement of the Z{sup 0} {yields} e{sup +}e{sup {minus}} partial width, {Gamma}{sub ee}, and the parity violation parameter, A{sub e}. From the combined 1992 and 1993 data the effective electron vector and axial vector couplings are measured to be {bar g}{sub v}{sup e} = {minus}0.0495{plus_minus}0.0096{plus_minus}0.0030, and {bar g}{sub {alpha}}{sup e} = {minus}0.4977{plus_minus}0.0035{plus_minus}0.0064 respectively. The effective weak mixing angle is measured to be sin{sup 2}{theta}{sub W}{sup eff} = 0.2251{plus_minus}0.0049{plus_minus}0.0015. These results are compared with other experiments.

Transient radiative transfer in a scattering slab considering polarization.

Science.gov (United States)

Yi, Hongliang; Ben, Xun; Tan, Heping

2013-11-04

The characteristics of the transient and polarization must be considered for a complete and correct description of short-pulse laser transfer in a scattering medium. A Monte Carlo (MC) method combined with a time shift and superposition principle is developed to simulate transient vector (polarized) radiative transfer in a scattering medium. The transient vector radiative transfer matrix (TVRTM) is defined to describe the transient polarization behavior of short-pulse laser propagating in the scattering medium. According to the definition of reflectivity, a new criterion of reflection at Fresnel surface is presented. In order to improve the computational efficiency and accuracy, a time shift and superposition principle is applied to the MC model for transient vector radiative transfer. The results for transient scalar radiative transfer and steady-state vector radiative transfer are compared with those in published literatures, respectively, and an excellent agreement between them is observed, which validates the correctness of the present model. Finally, transient radiative transfer is simulated considering the polarization effect of short-pulse laser in a scattering medium, and the distributions of Stokes vector in angular and temporal space are presented.

Intense γ-ray generation for a polarized positron beam in a linear collider

Directory of Open Access Journals (Sweden)

Y. Miyahara

2001-12-01

Full Text Available γ-ray generation by Compton backscattering in an optical lens series with periodic focal points is considered to produce a polarized positron beam for a linear collider. The lens series is composed of 20 unit cells with a length of 210 mm. Each lens has a hole to pass an electron beam with an energy of 5.8 GeV and the generated γ rays. It is shown by diffraction analysis that laser beam loss in the series is very small, and the beam size is periodically reduced to 26 μm. Electron beam size is reduced to 34 μm in a superconducting solenoid with a field of 15 T. To get a required γ-ray yield of 7×10^{15} γ/s, only one circularly polarized CO_{2} laser source with a power of 24 kW is needed.

Development of polarized beam conversion system for the linear collider complex

International Nuclear Information System (INIS)

Viilleval'd, G.S.; Vsevolozhskaya, T.A.; Karasyuk, V.N.; Sil'vestrov, G.I.; Chernyakin, A.D.

1983-01-01

Results of development of the polarized beam conversion system for the 150 GeV linear collider aiming at the linear collider operation with a high repetition rate (approximately 10 Hz), are presented. It is shown, that the conversion can be realized by means of ondulator radiation. Structurally, the spiral ondulator is two identical solenoids, inserted in each other in such a way, that their winding turns are alternating in the direction along the axis and they are supplied by countercurrents. The main parameters of the ondulator are as follows : winding pitch -0.7 cm, the ondulator length 150 m. For generation a field of the intensity 5 kOe it has been suggested that solenoids should be supplied by sinusoidal pulse current of duration approximately 200 μs. It is shown, that the introduction of iron into solenoid increases the efficiency by a factor of 2.1 and 2.7 in the ondulator with iron only in interloop gaps and with the addition of iron locking magnetic counterflow

Study of deep inelastic scattering of polarized electrons off polarized deuterons

International Nuclear Information System (INIS)

Kuriki, M.

1996-03-01

This thesis describes a 29GeV electron - nucleon scattering experiment carried out at Stanford Linear Accelerator Center (SLAC). Highly polarized electrons are scattered off a polarized ND 3 target. Scattered electrons are detected by two spectrometers located in End Station A (ESA) at angles of 4.5 degrees and 7 degrees with respect to the beam axis. We have measured the spin structure function g 1 of deuteron over the range of 0.029 2 2 . This integral indicates a discrepancy of more than three standard deviations from the prediction of the Ellis-Jaffe sum rule, 0.068±0.005 at Q 2 = 3.0(GeV/c) 2 while our result of g 1 d in good agreement with SMC results. Combined with g 1 of the proton, the measurement of ∫ 0 1 (g 1 d -g 1 n ) is 0.169±0.008. We also obtained the strong coupling constant at Q 2 = 3.0(GeV/c) 2 to be 0.417 -0.110 +0.086 , using the power correction for the sum rule up to third order of α s . This result is in agreement with the strong coupling constant α s (Q 2 ) = 3.0(GeV/c 2 ) obtained from various experiments. Using our deuteron results and the axial vector couplings of hyperon decays, the total quark polarization along the nucleon spin is found to be 0.286±.055, implying that quarks carry only 30% of the nucleon spin. The strange sea quark polarization is also determined to be -0.101 ± .023. These measurements are in agreement with other experiments and provide the world's most precise measurement of these quark polarizations. 80 refs., 151 figs., 23 tabs

Possibility of neutron electric form factor etermination in the d-vector(e,e'p-vector)n reaction

International Nuclear Information System (INIS)

Gakh, G.I.

1990-01-01

The polarization of protons produced in the vector-polarized deuteron disintegration by unpolarized electrons has been analyzed. The sensitivities of the polarization observation to the neutron electric form factor G en and also to different parametrizations of the deuteron wave functions (DWF) have been investigated in the framework of the relativistic impulse approximation. The present method of the G en determination does not require the use of the longitudinally polarized electron beams. 34 refs.; 9 figs

The optics of secondary polarized proton beams

International Nuclear Information System (INIS)

Carey, D.C.

1990-05-01

Polarized protons can be produced by the parity-violating decay of either lambda or sigma hyperons. A secondary bema of polarized protons can then be produced without the difficult procedure of accelerating polarized protons. The preservation of the polarization while the protons are being transmitted to a final focus places stringent limitations on the optics of the beam line. The equations of motion of a polarized particle in a magnetic field have been solved to first order for quadrupole and dipole magnets. The lowest order terms indicate that the polarization vector will be restored to its original direction upon passage through a magnetic system if the momentum vector is unaltered. Higher-order terms may be derived by an expansion in commutators of the rotation matrix and its longitudinal derivative. The higher-order polarization rotation terms then arise from the non-commutivity of the rotation matrices by large angles in three-dimensional space. 5 refs., 3 figs

QSPR studies for predicting polarity parameter of organic compounds in methanol using support vector machine and enhanced replacement method.

Science.gov (United States)

Golmohammadi, H; Dashtbozorgi, Z

2016-12-01

In the present work, enhanced replacement method (ERM) and support vector machine (SVM) were used for quantitative structure-property relationship (QSPR) studies of polarity parameter (p) of various organic compounds in methanol in reversed phase liquid chromatography based on molecular descriptors calculated from the optimized structures. Diverse kinds of molecular descriptors were calculated to encode the molecular structures of compounds, such as geometric, thermodynamic, electrostatic and quantum mechanical descriptors. The variable selection method of ERM was employed to select an optimum subset of descriptors. The five descriptors selected using ERM were used as inputs of SVM to predict the polarity parameter of organic compounds in methanol. The coefficient of determination, r 2 , between experimental and predicted polarity parameters for the prediction set by ERM and SVM were 0.952 and 0.982, respectively. Acceptable results specified that the ERM approach is a very effective method for variable selection and the predictive aptitude of the SVM model is superior to those obtained by ERM. The obtained results demonstrate that SVM can be used as a substitute influential modeling tool for QSPR studies.

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.

Navigation by light polarization in clear and turbid waters

Science.gov (United States)

Lerner, Amit; Sabbah, Shai; Erlick, Carynelisa; Shashar, Nadav

2011-01-01

Certain terrestrial animals use sky polarization for navigation. Certain aquatic species have also been shown to orient according to a polarization stimulus, but the correlation between underwater polarization and Sun position and hence the ability to use underwater polarization as a compass for navigation is still under debate. To examine this issue, we use theoretical equations for per cent polarization and electric vector (e-vector) orientation that account for the position of the Sun, refraction at the air–water interface and Rayleigh single scattering. The polarization patterns predicted by these theoretical equations are compared with measurements conducted in clear and semi-turbid coastal sea waters at 2 m and 5 m depth over sea floors of 6 m and 28 m depth. We find that the per cent polarization is correlated with the Sun's elevation only in clear waters. We furthermore find that the maximum value of the e-vector orientation angle equals the angle of refraction only in clear waters, in the horizontal viewing direction, over the deeper sea floor. We conclude that navigation by use of underwater polarization is possible under restricted conditions, i.e. in clear waters, primarily near the horizontal viewing direction, and in locations where the sea floor has limited effects on the light's polarization. PMID:21282170

Polarization effects in the 3-body system

International Nuclear Information System (INIS)

Ohlsen, G.G.

1978-01-01

An experimental review is given of polarization effects in the three-nucleon system. Inelastic processes are emphasized and some special topics on elastic scattering are also considered. The recent elastic nucleon--deuteron scattering result are discussed including the determination of the deuteron D state, vector n - d vs vector p - d vector analyzing power, the status of fits to polarization observables via Faddeev-type theory, and medium-energy elastic scattering. The treatment of the breakup experiments covers a general discussion of some of the possible kinematically complete breakup measurements and kinematically incomplete breakup experiments. 71 references

Polarized deuteron elastic scattering from a polarized proton target

Energy Technology Data Exchange (ETDEWEB)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Physikalisches Inst.); Zankel, H. (Graz Univ. (Austria). Inst. fuer Theoretische Physik)

1983-01-13

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76/sup 0/,85/sup 0/,98/sup 0/,115/sup 0/,132/sup 0/). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results.

Significant and variable linear polarization during the prompt optical flash of GRB 160625B.

Science.gov (United States)

Troja, E.; Lipunov, V. M.; Mundell, C. G.; Butler, N. R.; Watson, A. M.; Kobayashi, S.; Cenko, S. B.; Marshall, F. E.; Ricci, R.; Fruchter, A.; Wieringa, M. H.; Gorbovskoy, E. S.; Kornilov, V.; Kutyrev, A.; Lee, W. H.; Toy, V.; Tyurina, N. V.; Budnev, N. M.; Buckley, D. A. H.; González, J.; Gress, O.; Horesh, A.; Panasyuk, M. I.; Prochaska, J. X.; Ramirez-Ruiz, E.; Rebolo Lopez, R.; Richer, M. G.; Roman-Zuniga, C.; Serra-Ricart, M.; Yurkov, V.; Gehrels, N.

2017-07-01

Newly formed black holes of stellar mass launch collimated outflows (jets) of ionized matter that approach the speed of light. These outflows power prompt, brief and intense flashes of γ-rays known as γ-ray bursts (GRBs), followed by longer-lived afterglow radiation that is detected across the electromagnetic spectrum. Measuring the polarization of the observed GRB radiation provides a direct probe of the magnetic fields in the collimated jets. Rapid-response polarimetric observations of newly discovered bursts have probed the initial afterglow phase, and show that, minutes after the prompt emission has ended, the degree of linear polarization can be as high as 30 per cent - consistent with the idea that a stable, globally ordered magnetic field permeates the jet at large distances from the central source. By contrast, optical and γ-ray observations during the prompt phase have led to discordant and often controversial results, and no definitive conclusions have been reached regarding the origin of the prompt radiation or the configuration of the magnetic field. Here we report the detection of substantial (8.3 ± 0.8 per cent from our most conservative simulation), variable linear polarization of a prompt optical flash that accompanied the extremely energetic and long-lived prompt γ-ray emission from GRB 160625B. Our measurements probe the structure of the magnetic field at an early stage of the jet, closer to its central black hole, and show that the prompt phase is produced via fast-cooling synchrotron radiation in a large-scale magnetic field that is advected from the black hole and distorted by dissipation processes within the jet.

Light scattering of rectangular slot antennas: parallel magnetic vector vs perpendicular electric vector

Science.gov (United States)

Lee, Dukhyung; Kim, Dai-Sik

2016-01-01

We study light scattering off rectangular slot nano antennas on a metal film varying incident polarization and incident angle, to examine which field vector of light is more important: electric vector perpendicular to, versus magnetic vector parallel to the long axis of the rectangle. While vector Babinet’s principle would prefer magnetic field along the long axis for optimizing slot antenna function, convention and intuition most often refer to the electric field perpendicular to it. Here, we demonstrate experimentally that in accordance with vector Babinet’s principle, the incident magnetic vector parallel to the long axis is the dominant component, with the perpendicular incident electric field making a small contribution of the factor of 1/|ε|, the reciprocal of the absolute value of the dielectric constant of the metal, owing to the non-perfectness of metals at optical frequencies.

Time-reversal asymmetry: polarization and analyzing power in nuclear reactions

International Nuclear Information System (INIS)

Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

1984-01-01

Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers in the inverse reactions, initiated by polarized protons at the same center-of-mass energies, show significant differences. This implies the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show smaller differences. A discussion of instrumental asymmetries is presented

Time asymmetry: Polarization and analyzing power in the nuclear reactions

International Nuclear Information System (INIS)

Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

1983-01-01

Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented. (orig.)

The design and implementation of cost-effective algorithms for direct solution of banded linear systems on the vector processor system 32 supercomputer

Science.gov (United States)

Samba, A. S.

1985-01-01

The problem of solving banded linear systems by direct (non-iterative) techniques on the Vector Processor System (VPS) 32 supercomputer is considered. Two efficient direct methods for solving banded linear systems on the VPS 32 are described. The vector cyclic reduction (VCR) algorithm is discussed in detail. The performance of the VCR on a three parameter model problem is also illustrated. The VCR is an adaptation of the conventional point cyclic reduction algorithm. The second direct method is the Customized Reduction of Augmented Triangles' (CRAT). CRAT has the dominant characteristics of an efficient VPS 32 algorithm. CRAT is tailored to the pipeline architecture of the VPS 32 and as a consequence the algorithm is implicitly vectorizable.

Polarized light use in the nocturnal bull ant, Myrmecia midas.

Science.gov (United States)

Freas, Cody A; Narendra, Ajay; Lemesle, Corentin; Cheng, Ken

2017-08-01

Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas . We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1-2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts.

Numerical Simulations of Light Bullets, Using The Full Vector, Time Dependent, Nonlinear Maxwell Equations

Science.gov (United States)

Goorjian, Peter M.; Silberberg, Yaron; Kwak, Dochan (Technical Monitor)

1995-01-01

This paper will present results in computational nonlinear optics. An algorithm will be described that solves the full vector nonlinear Maxwell's equations exactly without the approximations that we currently made. Present methods solve a reduced scalar wave equation, namely the nonlinear Schrodinger equation, and neglect the optical carrier. Also, results will be shown of calculations of 2-D electromagnetic nonlinear waves computed by directly integrating in time the nonlinear vector Maxwell's equations. The results will include simulations of 'light bullet' like pulses. Here diffraction and dispersion will be counteracted by nonlinear effects. The time integration efficiently implements linear and nonlinear convolutions for the electric polarization, and can take into account such quantum effects as Karr and Raman interactions. The present approach is robust and should permit modeling 2-D and 3-D optical soliton propagation, scattering, and switching directly from the full-vector Maxwell's equations.

Electromagnetically induced transparency in the case of elliptic polarization of interacting fields

Science.gov (United States)

Parshkov, Oleg M.

2018-04-01

The theoretical investigation results of disintegration effect of elliptic polarized shot probe pulses of electromagnetically induced transparency in the counterintuitive superposed elliptic polarized control field and in weak probe field approximation are presented. It is shown that this disintegration occurs because the probe field in the medium is the sum of two normal modes, which correspond to elliptic polarized pulses with different speeds of propagation. The polarization ellipses of normal modes have equal eccentricities and mutually perpendicular major axes. Major axis of polarization ellipse of one normal mode is parallel to polarization ellipse major axis of control field, and electric vector of this mode rotates in the opposite direction, than electric vector of the control field. The electric vector other normal mode rotates in the same direction that the control field electric vector. The normal mode speed of the first type aforementioned is less than that of the second type. The polarization characteristics of the normal mode depend uniquely on the polarization characteristics of elliptic polarized control field and remain changeless in the propagation process. The theoretical investigation is performed for Λ-scheme of degenerated quantum transitions between 3P0, 3P10 and 3P2 energy levels of 208Pb isotope.

Vector boson scattering at CLIC

Energy Technology Data Exchange (ETDEWEB)

Kilian, Wolfgang; Fleper, Christian [Department Physik, Universitaet Siegen, 57068 Siegen (Germany); Reuter, Juergen [DESY Theory Group, 22603 Hamburg (Germany); Sekulla, Marco [Institut fuer Theoretische Physik, Karlsruher Institut fuer Technologie, 76131 Karlsruhe (Germany)

2016-07-01

Linear colliders operating in a range of multiple TeV are able to investigate the details of vector boson scattering and electroweak symmetry breaking. We calculate cross sections with the Monte Carlo generator WHIZARD for vector boson scattering processes at the future linear e{sup +} e{sup -} collider CLIC. By finding suitable cuts, the vector boson scattering signal processes are isolated from the background. Finally, we are able to determine exclusion sensitivities on the non-Standard Model parameters of the relevant dimension eight operators.

The polarization-angular structure and elliptical dichroism of the cross sections for three-photon bound-bound transitions in atoms

International Nuclear Information System (INIS)

Manakov, N.L.; Merem'yanin, A.V.

1997-01-01

Using the electric dipole approximation, we present, in invariant form, the cross section of an arbitrary three-photon transition between the discrete states of an atom with total angular momenta J i and J f . The cross section contains scalar and mixed products of the photon polarization vectors, and invariant atomic parameters dependent only on the photon frequencies. We determine the number of independent atomic parameters at fixed values of J i and J f and obtain their explicit expressions in terms of the reduced composite dipole matrix elements. The polarization dependence of the cross sections is expressed in terms of the degrees l and ξ of linear and circular photon polarizations. We analyze the phenomenon of dissipation-induced circular dichroism in three-photon processes, i.e., the difference Δ of the cross sections for opposite signs of the degree of circular polarization of all the photons. We study in detail the case of two identical photons and the phenomenon of elliptical dichroism, when Δ∼lξ holds and dichroism occurs only when the photons are elliptically polarized, with 0< vertical bar ξ vertical bar <1. Finally, we discuss the dissipation-induced effects of atom polarization in three-photon processes involving linearly polarized or unpolarized photons

Fractal vector optical fields.

Science.gov (United States)

Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

2016-07-15

We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field.

Interferometric polarization control

International Nuclear Information System (INIS)

Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

2006-01-01

We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results

Feasibility of maintaining in-plane polarization for a storage ring EDM search

Science.gov (United States)

Stephenson, Edward; Storage Ring EDM Collaboration

2014-09-01

A search for an electric dipole moment (EDM) on charged particles using a storage ring requires beam polarization lifetimes approaching 1000 s for in-plane polarization. A feasibility study using beam bunching and sextupole field adjustment is underway with a 0.97-GeV/c vector-polarized deuteron beam at COSY. The polarimeter consists of a thick carbon target positioned at the edge of the beam and the EDDA scintillation detectors. The DAQ system assigns a clock time to each polarimeter event. Once calibrated against the RF-cavity, the clock time is used to select events associated with a maximal sideways polarization (precessing at 120 kHz). With this tool, the in-plane polarization magnitude is tracked versus time. Electron cooling reduces the depolarization from finite emittance and second-order momentum spread acting through synchrotron oscillations. Further lifetime improvement to the level of hundreds of seconds is achieved by adjusting sextupole fields located in the COSY ring arcs at places of large transverse beta functions and dispersion. The dependence of the reciprocal of the lifetime on sextupole field strength is nearly linear, permitting an easy location of the best field values. These typically occur near loci of zero chromaticity. A search for an electric dipole moment (EDM) on charged particles using a storage ring requires beam polarization lifetimes approaching 1000 s for in-plane polarization. A feasibility study using beam bunching and sextupole field adjustment is underway with a 0.97-GeV/c vector-polarized deuteron beam at COSY. The polarimeter consists of a thick carbon target positioned at the edge of the beam and the EDDA scintillation detectors. The DAQ system assigns a clock time to each polarimeter event. Once calibrated against the RF-cavity, the clock time is used to select events associated with a maximal sideways polarization (precessing at 120 kHz). With this tool, the in-plane polarization magnitude is tracked versus time. Electron

THE EFFECT OF GRAVITATION ON THE POLARIZATION STATE OF A LIGHT RAY

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Tanay; Sen, A. K. [Department of Physics Assam University, Silchar-788011, Assam (India)

2016-12-10

In the present work, detailed calculations have been carried out on the rotation of the polarization vector of an electromagnetic wave due to the presence of a gravitational field of a rotating body. This has been done using the general expression of Maxwell’s equation in curved spacetime. Considering the far-field approximation (i.e., the impact parameter is greater than the Schwarzschild radius and rotation parameter), the amount of rotation of the polarization vector as a function of impact parameter has been obtained for a rotating body (considering Kerr geometry). The present work shows that the rotation of the polarization vector cannot be observed in the case of Schwarzschild geometry. This work also calculates the rotational effect when considering prograde and retrograde orbits for the light ray. Although the present work demonstrates the effect of rotation of the polarization vector, it confirms that there would be no net polarization of an electromagnetic wave due to the curved spacetime geometry in a Kerr field.

Time asymmetry: Polarization and analyzing power in the nuclear reactions

Energy Technology Data Exchange (ETDEWEB)

Rioux, C.; Roy, R.; Slobodrian, R.J. (Laval Univ., Quebec City (Canada). Lab. de Physique Nucleaire); Conzett, H.E. (California Univ., Berkeley (USA). Lawrence Berkeley Lab.)

1983-02-28

Measurements of the proton polarization in the reactions /sup 7/Li(/sup 3/He, p vector)/sup 9/Be and /sup 9/Be(/sup 3/He, p vector)/sup 11/B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction /sup 2/H(/sup 3/He, p vector)/sup 4/ He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented.

Positive Quasi Linear Operator Formulation

International Nuclear Information System (INIS)

Berry, L.A.; Jaeger, E.F.

2005-01-01

Expressions for the RF quasi-linear operator are biquadratic sums over the Fourier modes (or FLR equivalent) that describe the RF electric field with a kernel that is a function of the two wave vectors, k-vector L and k-vector R , in the sum. As a result of either an implicit or explicit average over field lines or flux surfaces, this kernel only depends on one parallel wave vector, conventionally k R -vector. When k-vector is an independent component of the representation for E, the sums are demonstrably positive. However, except for closed field line systems, k-vector is dependent on the local direction of the equilibrium magnetic field, and, empirically, the absorbed energy and quasi-linear diffusion coefficients are observed to have negative features. We have formally introduced an independent k-vector sum by Fourier transforming the RF electric field (assuming straight field lines) using a field-line-length coordinate. The resulting expression is positive. We have modeled this approach by calculating the quasi linear operator for 'modes' with fixed k-vector. We form these modes by discretizing k-vector and then assigning all of the Fourier components with k-vectorthat fall within a given k-vector bin to that k-vector mode. Results will be shown as a function of the number of bins. Future work will involve implementing the expressions derived from the Fourier transform and evaluating the dependence on field line length

Metasurface integrated high energy efficient and high linearly polarized InGaN/GaN light emitting diode.

Science.gov (United States)

Wang, Miao; Xu, Fuyang; Lin, Yu; Cao, Bing; Chen, Linghua; Wang, Chinhua; Wang, Jianfeng; Xu, Ke

2017-07-06

We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface. This significantly enhances the polarized light emission efficiency. Experimental results show that extraction efficiency of the polarized emission can be increased by 40% on average in a wide angle of ±60° compared to that with the naked bottom of sapphire substrate, or 20% compared to reflecting Al film on the bottom of a sapphire substrate. An extinction ratio (ER) of average value 20 dB within an angle of ±60° can be simultaneously obtained directly from an InGaN/GaN LED. Our results show the possibility of simultaneously achieving a high degree of polarization and high polarization extraction efficiency at the integrated device level. This advances the field of GaN LED toward energy efficiency, multi-functional applications in illumination, display, medicine, and light manipulation.

Photon beam polarization and non-dipolar angular distributions

International Nuclear Information System (INIS)

Peshkin, M.

1996-01-01

Angular distributions of ejecta from unoriented atoms and molecules depend upon the polarization state of the incident x-rays as well as upon the dynamics of the physical systems being studied. I recommend a simple geometrical way of looking at the polarization and its effects upon angular distributions. The polarization is represented as a vector in a parameter space that faithfully represents the polarization of the beam. The simple dependence of the angular dependence of the angular distributions on the polarization vector enables easy extraction of the dynamical information contained in those angular distributions. No new physical results emerge from this geometrical approach, but known consequences of the symmetries appear in an easily visualized form that I find pleasing and that has proved to be useful for planning experiments and for analyzing data

Impact of polarized e- and e+ beams at a future linear collider and a Z-factory. Pt. I. Fundamentals in polarization and electroweak precision physics

International Nuclear Information System (INIS)

Moortgat-Pick, Gudrid

2010-12-01

The main goal of new physics searches at a future Linear Collider is the precise determination of the underlying new physics model. The physics potential of the ILC as well as the multi-TeV option collider CLIC have to be optimized with regard to expected results from the LHC. The exploitation of spin effects plays a crucial role in this regard. After a short status report of the Linear Collider design and physics requirements, this article explains fundamentals in polarization and provides an overview of the impact of these spin effects in electroweak precision physics. (orig.)

Efficient high-power narrow-linewidth all-fibred linearly polarized ytterbium laser source

Science.gov (United States)

Bertrand, Anthony; Liégeois, Flavien; Hernandez, Yves; Giannone, Domenico

2012-06-01

We report on experimental results on a high power, all-fibred, linearly polarized, mode-locked laser at 1.03 μm. The laser generates pulses of 40 ps wide at a repetition rate of 52 MHz, exhibiting 12 kW peak power. Dispersion in optical fibres is controlled to obtain both high power and narrow spectral linewidth. The average output power reached is 25 W with a spectral linewidth of 380 pm and a near diffraction limit beam (M2 < 1.2). This laser is an ideal candidate for applications like IR spectroscopy, where high peak power and narrow linewidth are required for subsequent wavelength conversion.

Energy flow characteristics of vector X-Waves

KAUST Repository

Salem, Mohamed; Bagci, Hakan

2011-01-01

The vector form of X-Waves is obtained as a superposition of transverse electric and transverse magnetic polarized field components. It is shown that the signs of all components of the Poynting vector can be locally changed using carefully chosen complex amplitudes of the transverse electric and transverse magnetic polarization components. Negative energy flux density in the longitudinal direction can be observed in a bounded region around the centroid; in this region the local behavior of the wave field is similar to that of wave field with negative energy flow. This peculiar energy flux phenomenon is of essential importance for electromagnetic and optical traps and tweezers, where the location and momenta of microand nanoparticles are manipulated by changing the Poynting vector, and in detection of invisibility cloaks. © 2011 Optical Society of America.

Polarized Moessbauer transitions in mixed hyperfine interactions

International Nuclear Information System (INIS)

Barb, D.; Tarina, D.

1975-01-01

A contribution to the theory of elliptical polarization in the Moessbauer effect for transitions between mixed nuclear states is reported. A relation between the two-dimensional complex vector parameterization and the photon polarization density matrix was used in describing changes in the polarization of the gamma-ray involved. (A.K.)

Polarized coincidence electroproduction

International Nuclear Information System (INIS)

Heimann, R.L.

1975-03-01

A study is made of the inclusive electroproduction of single hadrons off a polarized target. Bjorken scaling laws and the hadron azimuthal distribution are derived from the quark parton model. The polarization asymmetries scale when the target spin is along the direction of the virtual photon, and (apart from significant exception) vanish for transverse spin. These results have a simple explanation; emphasis is given both to the general mathematical formalism and to intuitive physical reasoning. Through this framework other cases are considered: quarks with anomalous magnetic moment; renormalization group effects and asymptotic freedom; production of vector mesons (whose spin state is analysed by their decay); relation to large transverse momentum hadron production; and a covariant parton model calculation. Spin 0 partons and Regge singularities are also considered. All of these cases (apart from the last two) modify the pattern of conclusions. Vector meson production shows polarization enhancements in the density matrix element rhosub(0+); the renormalization group approach does not lead to any significant suppressions. They are also less severe in parton models for large Psub(T) hadrons, and are not supported by the covariantly formulated calculation. The origins of these differences are isolated and used to exemplify the sensitivity polarized hadron electroproduction has to delicate detail that is otherwise concealed. (author)

Optimal distribution of integration time for intensity measurements in degree of linear polarization polarimetry.

Science.gov (United States)

Li, Xiaobo; Hu, Haofeng; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie

2016-04-04

We consider the degree of linear polarization (DOLP) polarimetry system, which performs two intensity measurements at orthogonal polarization states to estimate DOLP. We show that if the total integration time of intensity measurements is fixed, the variance of the DOLP estimator depends on the distribution of integration time for two intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the DOLP estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time in an approximate way by employing Delta method and Lagrange multiplier method. According to the theoretical analyses and real-world experiments, it is shown that the variance of the DOLP estimator can be decreased for any value of DOLP. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improve the measurement accuracy of the polarimetry system.

Electron spin polarization induced by spin Hall effect in semiconductors with a linear in the momentum spin-orbit splitting of conduction band

OpenAIRE

Korenev, V. L.

2005-01-01

It is shown that spin Hall effect creates uniform spin polarization of electrons in semiconductor with a linear in the momentum spin splitting of conduction band. In turn, the profile of the non-uniform spin polarization accumulated at the edge of the sample oscillates in space even in the absence of an external magnetic field.

Forms and Linear Network Codes

DEFF Research Database (Denmark)

Hansen, Johan P.

We present a general theory to obtain linear network codes utilizing forms and obtain explicit families of equidimensional vector spaces, in which any pair of distinct vector spaces intersect in the same small dimension. The theory is inspired by the methods of the author utilizing the osculating...... spaces of Veronese varieties. Linear network coding transmits information in terms of a basis of a vector space and the information is received as a basis of a possibly altered vector space. Ralf Koetter and Frank R. Kschischang introduced a metric on the set af vector spaces and showed that a minimal...... distance decoder for this metric achieves correct decoding if the dimension of the intersection of the transmitted and received vector space is sufficiently large. The vector spaces in our construction are equidistant in the above metric and the distance between any pair of vector spaces is large making...

Theory of the photoelectric effect assisted by an elliptically polarized laser field

International Nuclear Information System (INIS)

Li Shumin; Jentschura, Ulrich D

2009-01-01

The laser-assisted photoelectric effect in atomic hydrogen is investigated for linear, circular and general elliptic polarizations. The perturbative dressed state of the atom in an elliptically polarized nonresonant laser field is derived in the velocity gauge. The continuum state of the ejected electron is described by a Coulomb-Volkov wavefunction. Numerical results show that the ionization cross section by a vacuum ultraviolet photon is enhanced at high laser field intensities and low frequencies. At small and extremely large scattering angles (measured with respect to the wave vector of the incoming vacuum ultraviolet photon), the process for emitting a laser photon is predominant, while at medium angles, the result favours the process without a laser photon exchange. The dependence of the results on the laser polarization and on various geometries is studied, and an interesting pattern is found for the dependence on the frequency of the dressing laser; an intuitive explanation is offered.

ELECTROCHEMICAL CORROSION STUDY VIA LINEAR POLARIZATION IN PEAS CAN

Directory of Open Access Journals (Sweden)

I. M. Costa

2016-09-01

Full Text Available The aim of this work is to study the corrosion of tinplate can for peas. Firstly, the characterization of canning solution was made. The values of pH, conductivity, Brix, viscosity, density and content of Fe were, respectively, 5.88; 32.6 mS/cm; 6.6%; 3,42cP; 1.026 g/ml; 12.05 mg/kg. The corrosion rate in the cans was determined by linear polarization technique. The electrodes with and without varnish were analyzed in the first and fifth day of the experiment for the 3 parts of the can. The corrosion rate increased significantly when the coating was removed and the body showed a higher corrosion rate, reaching 1.7 mm/year in the absence of varnish. The microstructure of the samples was evaluated by scanning electron microscopy (SEM coupled with energy dispersive spectroscopy (EDS. The increase of iron on the surface, evidenced by energy dispersive spectroscopy (EDS may have contributed to the corrosion in the samples without varnish.

Angular distribution coefficients for γ-ray polarization produced in polarized capture reactions

International Nuclear Information System (INIS)

Wulf, E.A.; Guillemette, J.; Weller, H.R.; Seyler, R.G.

1999-01-01

The previous publications have dealt with the angular momentum formalism of both linear and circularly polarized photons in (γ, x) reactions on both polarized and unpolarized targets, and the inverse (capture) reactions initiated by polarized beams. In the present work, utilizing the general formalism of Welton, the authors deal with the linear polarization of the γ-rays which are produced in capture reactions on unpolarized targets, including the possibility of having incident polarized spin 1/2 projectiles. These capture reactions are denoted by a(rvec x, rvec L)c, where rvec x is the incident polarized spin 1/2 projectile and rvec L represents the outgoing polarized γ-ray. They present here the formalism in a convenient form, display a sample table of coefficients, and illustrate its use by means of several examples. A FORTRAN code will be made available for generating similar coefficients for other reactions

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

Science.gov (United States)

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

2009-10-09

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

Quantum pump effect induced by a linearly polarized microwave in a two-dimensional electron gas.

Science.gov (United States)

Song, Juntao; Liu, Haiwen; Jiang, Hua

2012-05-30

A quantum pump effect is predicted in an ideal homogeneous two-dimensional electron gas (2DEG) that is normally irradiated by linearly polarized microwaves (MW). Without considering effects from spin-orbital coupling or the magnetic field, it is found that a polarized MW can continuously pump electrons from the longitudinal to the transverse direction, or from the transverse to the longitudinal direction, in the central irradiated region. The large pump current is obtained for both the low frequency limit and the high frequency case. Its magnitude depends on sample properties such as the size of the radiated region, the power and frequency of the MW, etc. Through the calculated results, the pump current should be attributed to the dominant photon-assisted tunneling processes as well as the asymmetry of the electron density of states with respect to the Fermi energy.

Exploring the top-Higgs FCNC couplings at polarized linear colliders with top spin observables

Energy Technology Data Exchange (ETDEWEB)

Melić, Blaženka; Patra, Monalisa [Institut Ruđer Bošković, Theoretical Physics Division,Bijenička 54, HR-10000 Zagreb (Croatia)

2017-01-11

We study the nature of flavor changing neutral couplings of the top quark with the Higgs boson and the up/charm quark in the tt̄ production at linear colliders. There are previous bounds on such tqH couplings at both, linear and hadronic colliders, with the assumption that the top couples equally to the left and the right handed fermions. In this paper we examine chirality of the tqH coupling and construct different observables which will be sensitive to it. The kinematics of the emitted q from t→qH in tt̄ production is discussed and it was found that the polar angle distribution of q is sensitive to the chiral nature of tqH couplings. The observables in the context of top-antitop spin correlations, which are sensitive to new physics in the top decay are considered using different spin-quantization bases. It was found that in particular the off-diagonal basis can be useful to distinguish among the chiral tqH couplings. The sensitivity of the unpolarized ILC in probing the couplings at the 3σ level at √s = 500 GeV and L = 500 fb{sup −1} is also studied, resulting in predicted BR(t→qH)<1.19×10{sup −3}. This limit is further improved to BR(t→qH)<8.84×10{sup −4} with the inclusion of initial beam polarization of left handed electrons and right handed positrons.

Polarization of Coronal Forbidden Lines

Energy Technology Data Exchange (ETDEWEB)

Li, Hao; Qu, Zhongquan [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Landi Degl’Innocenti, Egidio, E-mail: sayahoro@ynao.ac.cn [Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy)

2017-03-20

Since the magnetic field is responsible for most manifestations of solar activity, one of the most challenging problems in solar physics is the diagnostics of solar magnetic fields, particularly in the outer atmosphere. To this end, it is important to develop rigorous diagnostic tools to interpret polarimetric observations in suitable spectral lines. This paper is devoted to analyzing the diagnostic content of linear polarization imaging observations in coronal forbidden lines. Although this technique is restricted to off-limb observations, it represents a significant tool to diagnose the magnetic field structure in the solar corona, where the magnetic field is intrinsically weak and still poorly known. We adopt the quantum theory of polarized line formation developed in the framework of the density matrix formalism, and synthesize images of the emergent linear polarization signal in coronal forbidden lines using potential-field source-surface magnetic field models. The influence of electronic collisions, active regions, and Thomson scattering on the linear polarization of coronal forbidden lines is also examined. It is found that active regions and Thomson scattering are capable of conspicuously influencing the orientation of the linear polarization. These effects have to be carefully taken into account to increase the accuracy of the field diagnostics. We also found that linear polarization observation in suitable lines can give valuable information on the long-term evolution of the magnetic field in the solar corona.

Estimation of Nonlinear Functions of State Vector for Linear Systems with Time-Delays and Uncertainties

Directory of Open Access Journals (Sweden)

Il Young Song

2015-01-01

Full Text Available This paper focuses on estimation of a nonlinear function of state vector (NFS in discrete-time linear systems with time-delays and model uncertainties. The NFS represents a multivariate nonlinear function of state variables, which can indicate useful information of a target system for control. The optimal nonlinear estimator of an NFS (in mean square sense represents a function of the receding horizon estimate and its error covariance. The proposed receding horizon filter represents the standard Kalman filter with time-delays and special initial horizon conditions described by the Lyapunov-like equations. In general case to calculate an optimal estimator of an NFS we propose using the unscented transformation. Important class of polynomial NFS is considered in detail. In the case of polynomial NFS an optimal estimator has a closed-form computational procedure. The subsequent application of the proposed receding horizon filter and nonlinear estimator to a linear stochastic system with time-delays and uncertainties demonstrates their effectiveness.

Inference from correlated patterns: a unified theory for perceptron learning and linear vector channels

Energy Technology Data Exchange (ETDEWEB)

Kabashima, Y [Department of Computational Intelligence and Systems Science, Tokyo Institute of Technology, Yokohama 226-8502 (Japan)], E-mail: kaba@dis.titech.ac.jp

2008-01-15

A framework to analyze inference performance in densely connected single-layer feed-forward networks is developed for situations where a given data set is composed of correlated patterns. The framework is based on the assumption that the left and right singular value bases of the given pattern matrix are generated independently and uniformly from Haar measures. This assumption makes it possible to characterize the objective system by a single function of two variables which is determined by the eigenvalue spectrum of the cross-correlation matrix of the pattern matrix. Links to existing methods for analysis of perceptron learning and Gaussian linear vector channels and an application to a simple but nontrivial problem are also shown.

Inference from correlated patterns: a unified theory for perceptron learning and linear vector channels

International Nuclear Information System (INIS)

Kabashima, Y

2008-01-01

A framework to analyze inference performance in densely connected single-layer feed-forward networks is developed for situations where a given data set is composed of correlated patterns. The framework is based on the assumption that the left and right singular value bases of the given pattern matrix are generated independently and uniformly from Haar measures. This assumption makes it possible to characterize the objective system by a single function of two variables which is determined by the eigenvalue spectrum of the cross-correlation matrix of the pattern matrix. Links to existing methods for analysis of perceptron learning and Gaussian linear vector channels and an application to a simple but nontrivial problem are also shown

Inference from correlated patterns: a unified theory for perceptron learning and linear vector channels

Science.gov (United States)

Kabashima, Y.

2008-01-01

A framework to analyze inference performance in densely connected single-layer feed-forward networks is developed for situations where a given data set is composed of correlated patterns. The framework is based on the assumption that the left and right singular value bases of the given pattern matrix are generated independently and uniformly from Haar measures. This assumption makes it possible to characterize the objective system by a single function of two variables which is determined by the eigenvalue spectrum of the cross-correlation matrix of the pattern matrix. Links to existing methods for analysis of perceptron learning and Gaussian linear vector channels and an application to a simple but nontrivial problem are also shown.

Statistics of polarization speckle: theory versus experiment

DEFF Research Database (Denmark)

Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo

2010-01-01

In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

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.J.; Kononets, Yu.V.; Lopez, A.; Mangiarotti, A.; van Rens, B.; Sellschop, J.P.F.; Shieh, M.; Sona, P.; Strakhovenko, V.; Uggerhoj, E.; Uggerhj, Ulrik Ingerslev; Unel, 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.

A polarized alkali ion source

International Nuclear Information System (INIS)

Boettger, R.; Tungate, G.; Bauer, B.; Egelhof, P.; Moebius, K.H.; Steffens, E.

1978-01-01

The beam foil technique has been applied to detect nuclear vector polarization of a 10 keV 23 Na + beam. The result was about 70% of the atomic beam polarization thus limiting the depolarization by the surface ionizer to at most 30%. In a Coulomb excitation experiment with a tensor polarized 42 MeV 23 Na 7+ beam an effect of 0.011 +- 0.003 was measured yielding a value of t 20 approx. 0.04 for the beam polarization. The depolarization during the acceleration process can be estimated to be about 0.8. (orig.) [de

A search for time variability and its possible regularities in linear polarization of Be stars

International Nuclear Information System (INIS)

Huang, L.; Guo, Z.H.; Hsu, J.C.; Huang, L.

1989-01-01

Linear polarization measurements are presented for 14 Be stars obtained at McDonald Observatory during four observing runs from June to November of 1983. Methods of observation and data reduction are described. Seven of eight program stars which were observed on six or more nights exhibited obvious polarimetric variations on time-scales of days or months. The incidence is estimated as 50% and may be as high as 93%. No connection can be found between polarimetric variability and rapid periodic light or spectroscopic variability for our stars. Ultra-rapid variability on time-scale of minutes was searched for with negative results. In all cases the position angles also show variations indicating that the axis of symmetry of the circumstellar envelope changes its orientation in space. For the Be binary CX Dra the variations in polarization seems to have a period which is just half of the orbital period

Energy-exchange collisions of dark-bright-bright vector solitons.

Science.gov (United States)

Radhakrishnan, R; Manikandan, N; Aravinthan, K

2015-12-01

We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

Polarized electron sources

Energy Technology Data Exchange (ETDEWEB)

Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

1994-12-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

Polarized electron sources

International Nuclear Information System (INIS)

Prepost, R.

1994-01-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

Experimental method for investigating γd→pn photodisintegration reaction on the linearly polarized photon beam of the Erevan synchrotron

International Nuclear Information System (INIS)

Agababyan, K.Sh.; Adamyan, F.V.; Ajrapetyan, A.V.

1985-01-01

The experimental method for measuring the asymmetry of the γd → pn photodisintegration reaction on the linearly polarized photon beam of the Erevan synchrotron is described. The results of Monte Carlo calculations, the calibration of apparatus, the procedure of measurements and experimental data processing are repored

Adapting the HSV polarization-color mapping for regions with low irradiance and high polarization.

Science.gov (United States)

Scott Tyo, J; Ratliff, Bradley M; Alenin, Andrey S

2016-10-15

Many mappings from polarization into color have been developed so that polarization information can be displayed. One of the most common of these maps the angle of linear polarization into color hue and degree of linear polarization into color saturation, while preserving the irradiance information from the polarization data. While this strategy enjoys wide popularity, there is a large class of polarization images for which it is not ideal. It is common to have images where the strongest polarization signatures (in terms of degree of polarization) occur in regions of relatively low irradiance: either in shadow in reflective bands or in cold regions in emissive bands. Since the irradiance is low, the chromatic properties of the resulting images are generally not apparent. Here we present an alternate mapping that uses the statistics of the angle of polarization as a measure of confidence in the polarization signature, then amplifies the irradiance in regions of high confidence, and leaves it unchanged in regions of low confidence. Results are shown from an LWIR and a visible spectrum imager.

Radiochromic film and polarization effects

International Nuclear Information System (INIS)

Yu, P.K.N.; Cheung, T.; Butson, M.J.; Cancer Services, Wollongong, NSW; Inwood, D.

2004-01-01

Full text: A new high sensitivity radiochromic film has been tested for its polarization properties. Gafchromic HS film has been shown to produce a relatively small (less than 3%) variation in measured optical density measured at 660nm wavelength when the light source is fully linear polarized and the film is rotated through 360 deg angle. Similar variations are seen when the detector is linearly polarized. If both light source and detector is linearly polarised variations in measured optical density can reach 15% when the film is rotated through 360 deg angle. This seems to be due to a phase shift in polarised light caused by the radiochromic film resulting in the polarised light source becoming out of phase with the polarised detector. Gafchromic HS radiochromic film produces a minimal polarization response with varying angle of rotation however we recommend that a polarization test be performed on a densitometry system to establish the extent of its polarization properties before accuracy dosimetry is performed with radiochromic HS film. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Spin-Polarization in Quasi-Magnetic Tunnel Junctions

Science.gov (United States)

Xie, Zheng-Wei; Li, Ling

2017-05-01

Spin polarization in ferromagnetic metal/insulator/spin-filter barrier/nonmagnetic metal, referred to as quasi-magnetic tunnel junctions, is studied within the free-electron model. Our results show that large positive or negative spin-polarization can be obtained at high bias in quasi-magnetic tunnel junctions, and within large bias variation regions, the degree of spin-polarization can be linearly tuned by bias. These linear variation regions of spin-polarization with bias are influenced by the barrier thicknesses, barrier heights and molecular fields in the spin-filter (SF) layer. Among them, the variations of thickness and heights of the insulating and SF barrier layers have influence on the value of spin-polarization and the linear variation regions of spin-polarization with bias. However, the variations of molecular field in the SF layer only have influence on the values of the spin-polarization and the influences on the linear variation regions of spin-polarization with bias are slight. Supported by the Key Natural Science Fund of Sichuan Province Education Department under Grant Nos 13ZA0149 and 16ZA0047, and the Construction Plan for Scientific Research Innovation Team of Universities in Sichuan Province under Grant No 12TD008.

T-odd polarization observables in deuteron electrodisintegration

International Nuclear Information System (INIS)

Rekalo, M.P.; Gakh, G.I.; Rekalo, A.P.

1996-01-01

It is considered such simplest T-odd polarization observables of the deuteron disintegration as proton polarization in d(e, e' p-bar)n and the asymmetry in the scattering of unpolarized electrons by a vector-polarized target, d-bar (e, e' p)n. The θ dependence of theses observables has been studied. The procedure of making the conserved electromagnetic current has an essential influence on the final θ dependence of the T-odd polarization observables [ru

Double-spin asymmetry of J/ψ production in polarized pp-collisions at HERA-N-vector polarized

International Nuclear Information System (INIS)

Teryaev, O.; Tkabladze, A.

1996-01-01

We calculated the color-octet contribution to the double spin asymmetry of J/ψ hadroproduction with nonzero transverse momenta at fixed target energies √ s ≅ 40 GeV. It is shown that color-octet contribution is dominant in the asymmetries. The expected asymmetries and statistical errors in a future option of HERA with longitudinally polarized protons at √ s = 39 GeV (HERA-N polarized) should allow one to distinguish between different parametrizations for polarized gluon distribution in proton

A new approach to radiative transfer theory using Jones's vectors. I

International Nuclear Information System (INIS)

Fymat, A.L.; Vasudevan, R.

1975-01-01

Radiative transfer of partially polarized radiation in an anisotropically scattering, inhomogeneous atmosphere containing arbitrary polydispersion of particles is described using Jones's amplitude vectors and matrices. This novel approach exploits the close analogy between the quantum mechanical states of spin 1/2 systems and the polarization states of electromagnetic radiation described by Jones's vector, and draws on the methodology of such spin 1/2 systems. The complete equivalence between the transport equation for Jones's vectors and the classical radiative transfer equation for Stokes's intensity vectors is demonstrated in two independent ways after deriving the transport equations for the polarization coherency matrices and for the quaternions corresponding to the Jones's vectors. A compact operator formulation of the theory is provided, and used to derive the necessary equations for both a local and a global description of the transport of Jones's vectors. Lastly, the integro-differential equations for the amplitude reflection and transmission matrices are derived, and related to the usual corresponding equations. The present formulation is the most succinct and the most convenient one for both theoretical and experimental studies. It yields a simpler analysis than the classical formulation since it reduces by a factor of two the dimensionality of transfer problems. It preserves information on phases, and thus can be used directly across the entire electromagnetic spectrum without any further conversion into intensities. (Auth.)

Implicit Real Vector Automata

Directory of Open Access Journals (Sweden)

Jean-François Degbomont

2010-10-01

Full Text Available This paper addresses the symbolic representation of non-convex real polyhedra, i.e., sets of real vectors satisfying arbitrary Boolean combinations of linear constraints. We develop an original data structure for representing such sets, based on an implicit and concise encoding of a known structure, the Real Vector Automaton. The resulting formalism provides a canonical representation of polyhedra, is closed under Boolean operators, and admits an efficient decision procedure for testing the membership of a vector.

Linear Magnetochiral effect in Weyl Semimetals

Science.gov (United States)

Cortijo, Alberto

We describe the presence of a linear magnetochiral effect in time reversal breaking Weyl semimetals. The magnetochiral effect consists in a simultaneous linear dependence of the magnetotransport coefficients with the magnetic field and a momentum vector. This simultaneous dependence is allowed by the Onsager reciprocity relations, being the separation vector between the Weyl nodes the vector that plays such role. This linear magnetochiral effect constitutes a new transport effect associated to the topological structures linked to time reversal breaking Weyl semimetals. European Union structural funds and the Comunidad de Madrid MAD2D-CM Program (S2013/MIT-3007) and MINECO (Spain) Grant No. FIS2015-73454-JIN.

Spin-polarized SEM

International Nuclear Information System (INIS)

Konoto, Makoto

2007-01-01

Development of highly effective evaluation technology of magnetic structures on a nanometric scale is a key to understanding spintronics and related phenomena. A high-resolution spin-polarized scanning electron microscope (spin SEM) developed recently is quite suitable for probing such nanostructures because of the capability of analyzing local magnetization vectors in three dimensions. Utilizing the spin SEM, a layered antiferromagnetic structure with the 1nm-alternation of bilayer-sheet magnetization has been successfully resolved. The real-space imaging with full analysis of the temperature-dependent magnetization vectors will be demonstrated. (author)

Polarization of Be stars

International Nuclear Information System (INIS)

Johns, M.W.

1975-01-01

Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

Vector and axial constants of the baryon decuplet

International Nuclear Information System (INIS)

Belyaev, V.M.; Blok, B.Y.; Kogan, Y.I.

1985-01-01

On the basis of the QCD sum rules for the polarization operator in external axial and vector fields we determine the vector and axial transition constants in the 3/2 + baryon decuplet. We show that the renormalization of the axial constant is due to the interaction of the external axial field with the quark condensate

Osculating Spaces of Varieties and Linear Network Codes

DEFF Research Database (Denmark)

Hansen, Johan P.

2013-01-01

We present a general theory to obtain good linear network codes utilizing the osculating nature of algebraic varieties. In particular, we obtain from the osculating spaces of Veronese varieties explicit families of equidimensional vector spaces, in which any pair of distinct vector spaces...... intersects in the same dimension. Linear network coding transmits information in terms of a basis of a vector space and the information is received as a basis of a possible altered vector space. Ralf Koetter and Frank R. Kschischang introduced a metric on the set af vector spaces and showed that a minimal...... distance decoder for this metric achieves correct decoding if the dimension of the intersection of the transmitted and received vector space is sufficiently large. The obtained osculating spaces of Veronese varieties are equidistant in the above metric. The parameters of the resulting linear network codes...

Osculating Spaces of Varieties and Linear Network Codes

DEFF Research Database (Denmark)

Hansen, Johan P.

We present a general theory to obtain good linear network codes utilizing the osculating nature of algebraic varieties. In particular, we obtain from the osculating spaces of Veronese varieties explicit families of equideminsional vector spaces, in which any pair of distinct vector spaces...... intersects in the same dimension. Linear network coding transmits information in terms of a basis of a vector space and the information is received as a basis of a possible altered vector space. Ralf Koetter and Frank R. Kschischang introduced a metric on the set af vector spaces and showed that a minimal...... distance decoder for this metric achieves correct decoding if the dimension of the intersection of the transmitted and received vector space is sufficiently large. The obtained osculating spaces of Veronese varieties are equidistant in the above metric. The parameters of the resulting linear network codes...

Deuteron tensor polarization in the e-+d →e-+p+n process

International Nuclear Information System (INIS)

Rekalo, M.P.; Gakh, G.I.; Rekalo, A.P.

1988-01-01

The polarization phenomena in the d-vector(e, ep)n reaction caused by the deuteron tensor polarization have been investigated in the relativistic impulse approximation (IA) framework. It is shown that in general case the tensor polarization leads to 16 Asymmetries. Sensitivity of these observables to the choice of the deuteron wave function parametrization has been investigated. The calculated asymmetry in the d-vector(e, pn)e' reation caused by the tensor polarization of the target is in good agreement with experimental data obtained in Novosibirsk. The calculated asymmetry in the nonrelativistic and relativistic IA are significantly different

A new polarized neutrons method for studying depth-inhomogeneously magnetized magnetic films

International Nuclear Information System (INIS)

Korneev, D.A.

1990-01-01

The main specific features of the process of polarized thermal neutrons specular reflection from the surface of depth-inhomogeneously magnetic films are considered theoretically. It is shown how using the method of specular reflection of polarized thermal neutrons from such a films surface, one may restore the depth distribution of the local magnetization vector M-vector(z). 9 refs

Tensor calculus in polar coordinates using Jacobi polynomials

Science.gov (United States)

Vasil, Geoffrey M.; Burns, Keaton J.; Lecoanet, Daniel; Olver, Sheehan; Brown, Benjamin P.; Oishi, Jeffrey S.

2016-11-01

Spectral methods are an efficient way to solve partial differential equations on domains possessing certain symmetries. The utility of a method depends strongly on the choice of spectral basis. In this paper we describe a set of bases built out of Jacobi polynomials, and associated operators for solving scalar, vector, and tensor partial differential equations in polar coordinates on a unit disk. By construction, the bases satisfy regularity conditions at r = 0 for any tensorial field. The coordinate singularity in a disk is a prototypical case for many coordinate singularities. The work presented here extends to other geometries. The operators represent covariant derivatives, multiplication by azimuthally symmetric functions, and the tensorial relationship between fields. These arise naturally from relations between classical orthogonal polynomials, and form a Heisenberg algebra. Other past work uses more specific polynomial bases for solving equations in polar coordinates. The main innovation in this paper is to use a larger set of possible bases to achieve maximum bandedness of linear operations. We provide a series of applications of the methods, illustrating their ease-of-use and accuracy.