Jaenkaelae, K. [Department of Physics, P.O. Box 3000, 90014 University of Oulu, Oulu (Finland); Alagia, M. [CNR-IOM, Laboratorio TASC, IT-34149 Trieste (Italy); Feyer, V.; Richter, R. [Sincrotrone Trieste, Area Science Park, IT-34149 Trieste (Italy); Prince, K. C. [Sincrotrone Trieste, Area Science Park, IT-34149 Trieste (Italy); CNR-IOM, Laboratorio TASC, IT-34149 Trieste (Italy)
2011-11-15T23:59:59.000Z
Laser orientation in the initial state has been used to study the properties of satellite transitions in inner-shell photoionization of rubidium atoms. The linear magnetic dichroism in the angular distribution (LMDAD) has been utilized to probe the continuum waves of orbital angular momentum conserving monopole, and angular momentum changing conjugate satellites, accompanying the 4p ionization of atomic Rb. We show experimentally that LMDAD of both types of satellite transitions is nonzero and that LMDAD of monopole satellites, measured as a function of photon energy, mimics the LMDAD of direct photoionization, whereas the LMDAD of conjugate transitions deviates drastically from that trend. The results indicate that conjugate transitions cannot be described theoretically without explicit inclusion of electron-electron interaction. The present data can thus be used as a very precise test of current models for photoionization.
V. Socoliuc; L. B. Popescu
2014-10-09T23:59:59.000Z
An analytical theoretical model for the influence of the magnetically induced nanoparticle chaining on the linear dichroism in ferrofluids was developed. The model is based on a statistical theory for magnetic nanoparticle chaining in ferrofluids. Together with appropriate experimental approach and data processing strategy, the model grounds a magneto-optical granulometry method able to determine the magnetic field dependence of the statistics of magnetically induced particle chains in concentrated ferrofluids.
Circular dichroism of planar chiral magnetic metamaterials
Circular dichroism of planar chiral magnetic metamaterials M. Decker, M. W. Klein, and M. Wegener 78002); published March 5, 2007 We propose, fabricate, and study a double-layer chiral planar
Magnetic Dichroism Spectromicroscopy at SPEAR3
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Properties of thin film europium oxide by x-ray magnetic circular dichroism Johnathon Holroyda)
Idzerda, Yves
Properties of thin film europium oxide by x-ray magnetic circular dichroism Johnathon Holroyda Institute of Physics. DOI: 10.1063/1.1688653 I. INTRODUCTION Europium oxide is optically transparent
Arbelaez, D.; Black, A.; Prestemon, S.O.; Wang, S.; Chen, J.; Arenholz, E.
2010-01-13T23:59:59.000Z
An eight-pole superconducting magnet is being developed for soft x-ray magnetic dichroism (XMD) experiments at the Advanced Light Source, Lawrence Berkley National Laboratory (LBNL). Eight conical Nb{sub 3}Sn coils with Holmium poles are arranged in octahedral symmetry to form four dipole pairs that provide magnetic fields of up to 5 T in any direction relative to the incoming x-ray beam. The dimensions of the magnet yoke as well as pole taper, diameter, and length were optimized for maximum peak field in the magnet center using the software package TOSCA. The structural analysis of the magnet is performed using ANSYS with the coil properties derived using a numerical homogenization scheme. It is found that the use of orthotropic material properties for the coil has an important influence in the design of the magnet.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Rusz, Jan; Idrobo, Juan -Carlos; Bhowmick, Somnath
2014-09-30T23:59:59.000Z
The calculations presented here reveal that an electron probe carrying orbital angular momentum is just a particular case of a wider class of electron beams that can be used to measure electron magnetic circular dichroism (EMCD) with atomic resolution. It is possible to obtain an EMCD signal with atomic resolution by simply breaking the symmetry of the electron probe phase front using the aberration-corrected optics of an scanning transmission electron microscope. The phase distribution of the probe depends on the magnetic symmetry and crystal structure of the sample. The calculations indicate that EMCD signals utilizing the phase of the electronmore »probe are as strong as those obtained by nanodiffraction methods.« less
Spin polarization and magnetic dichroism in core-level photoemission from ferromagnets
Menchero, J G [Univ. of California, Berkeley, CA (United States). Dept. of Physics
1997-05-01T23:59:59.000Z
In this thesis we present a theoretical investigation of angle- and spin-resolved core-level photoemission from ferromagnetic Fe and Ni. We also consider magneto-dichroic effects due to reversal of the photon helicity or reversal of the sample magnetization direction. In chapter 1, we provide a brief outline of the history of photoemission, and show how it has played an important role in the development of modern physics. We then review the basic elements of the theory of core-level photoemission, and discuss the validity of the some of the commonly-used approximations. In chapter 2, we present a one-electron theory to calculate spin- and angle-resolved photoemission spectra for an arbitrary photon polarization. The Hamiltonian includes both spin-orbit and exchange interactions. As test cases for the theory, we calculate the spin polarization and magnetic dichroism for the Fe 2p core level, and find that agreement with experiment is very good.
Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (MillionStructural Basis of5, 2014 | ReleaseUNCLASSI HExchange-springAugustofUnexpected
Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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0.8 T in arbitrary directions, crucial for the study of the XMLD angular dependence. The Ni2+ moments in NiFe2O4 films are coupled ferromagnetically and can be aligned in any...
Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism
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Atomic moments in Mn2CoAl thin films analyzed by X-ray magnetic circular dichroism
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Jamer, M. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics; Sterbinsky, G. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Assaf, B. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics; Arena, D. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Heiman, D. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics
2014-12-07T23:59:59.000Z
Spin gapless semiconductors are known to be strongly affected by structural disorder when grown epitaxially as thin films. The magnetic properties of Mn2CoAl thin films grown on GaAs (001) substrates are investigated here as a function of annealing. This study investigates the atomic-specific magnetic moments of Mn and Co atoms measured through X-ray magnetic circular dichroism as a function of annealing and the consequent structural ordering. The results indicate that the structural distortion mainly affects the Mn atoms as seen by the reduction of the magnetic moment from its predicted value. (auth)
Wilson, Daniel; Rudolf, Denis, E-mail: d.rudolf@fz-juelich.de; Juschkin, Larissa [RWTH Aachen University, Experimental Physics of EUV, Steinbachstraße 15, 52074 Aachen (Germany); Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany); Weier, Christian; Adam, Roman; Schneider, Claus M. [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-6), JARA-FIT, 52425 Jülich (Germany); Winkler, Gerrit; Frömter, Robert [Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Danylyuk, Serhiy [RWTH Aachen University, Chair for Technology of Optical Systems, JARA-FIT, Steinbachstraße 15, 52074 Aachen (Germany); Bergmann, Klaus [Fraunhofer Institute for Laser Technology, Steinbachstrasse 15, 52074 Aachen (Germany); Grützmacher, Detlev [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany)
2014-10-15T23:59:59.000Z
Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.
Nuclear spin circular dichroism
Vaara, Juha, E-mail: juha.vaara@iki.fi [NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland)] [NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland); Rizzo, Antonio [Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa (Italy)] [Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa (Italy); Kauczor, Joanna; Norman, Patrick [Department of Physics, Chemistry and Biology, Linköping University, S-58183 Linköping (Sweden)] [Department of Physics, Chemistry and Biology, Linköping University, S-58183 Linköping (Sweden); Coriani, Sonia, E-mail: coriani@units.it [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy)] [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy)
2014-04-07T23:59:59.000Z
Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.
Lee, Yongbin; Kim, Jong-Woo; Goldman, Alan I.; Harmon, Bruce N. (Iowa State)
2010-07-19T23:59:59.000Z
In this study we have used first principles electronic structure methods to investigate the detailed contributions to the L{sub 3}/L{sub 2} branching ratio in the heavy rare earth elements. The calculations use the full potential, relativistic, linear augmented plane wave method with the LSDA+U approach for consideration of the local 4f electronic orbitals. With no spin orbit coupling (SOC) in the conducting bands, and with the same radial function for the 2p{sub 3/2} and 2p{sub 1/2} core states, the branching ratio (BR) is exactly 1:-1 for the x-ray magnetic circular dichroism spectra of the ferromagnetic heavy rare earth metals. However, with full SOC the BR ranges from 1.5 to 6.0 in going from Gd to Er. The energy and spin dependence of the 5d radial functions are important. The results point to problems with modified atomic models which have been proposed to explain the BR. Recent x-ray resonant magentic scattering experiments on (Gd,Tb,Dy,Ho,Er,Tm)Ni{sub 2}Ge{sub 2} are discussed.
de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M. A.; Haskel, D.; te Velthuis, S. G. E; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian Fernandez, C.; Garcia, M. A.; Univ.Complutense de Madrid; Inst. de Magnetismo Aplicado; Univ. of Pisa; Lab. di Magnetismo Molecolare
2009-01-01T23:59:59.000Z
X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 {center_dot} 10{sup -4} was found at the Au L{sub 3} edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M{sub s}, of 0.06 emu/g{sub Au}. SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences.
de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M. A.; Haskel, D.; Pinel, E. F.; te Velthuis, S. G. E.; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian, C.; Garcia, M. A.; Univ. Complutense de Madrid; Inst. de Magnetismo Aplicado UCM; Univ. Pisa; Univ. di Padova
2009-11-01T23:59:59.000Z
X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 {center_dot} 10{sup -4} was found at the Au L{sub 3} edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M{sub s}, of 0.06 emu/g{sub Au}. SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences.
Ito, Keita; Sanai, Tatsunori; Yasutomi, Yoko; Toko, Kaoru; Suemasu, Takashi, E-mail: suemasu@bk.tsukuba.ac.jp [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Zhu, Siyuan; Kimura, Akio [Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Takeda, Yukiharu; Saitoh, Yuji [Condensed Matter Science Division, Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan)
2014-05-07T23:59:59.000Z
We evaluated orbital (m{sub orb}) and spin magnetic moments (m{sub spin}) of Co{sub x}Fe{sub 4?x}N (x?=?0, 3, 4) epitaxial thin films grown by molecular beam epitaxy using x-ray magnetic circular dichroism, and discussed the dependence of these values on x. Site-averaged m{sub spin} value of Fe atoms was deduced to be 1.91??{sub B} per atom, and that of Co atoms to be 1.47??{sub B} per atom in Co{sub 3}FeN at 300?K. These values are close to 1.87??{sub B} per Fe atom in Fe{sub 4}N and 1.43??{sub B} per Co atom in Co{sub 4}N, respectively. This result implies that the Fe and Co atoms in the Co{sub 3}FeN films were located both at corner and face-centered sites in the anti-perovskite lattice. Spin magnetic moments per unit cell were decreased linearly with increasing x in Co{sub x}Fe{sub 4?x}N. This tendency is in good agreement with theory predicted by the first-principle calculation.
Ground-state wave function of plutonium in PuSb as determined via x-ray magnetic circular dichroism
Janoschek, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haskel, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Fernandez-Rodriguez, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Northern Illinois Univ., DeKalb, IL (United States); van Veenendaal, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Northern Illinois Univ., DeKalb, IL (United States); Rebizant, J. [Institute for Transuranium Elements, Karlsruhe (Germany); Lander, G. H. [Institute for Transuranium Elements, Karlsruhe (Germany); Zhu, J. -X. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, J. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bauer, E. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-01-01T23:59:59.000Z
Measurements of x-ray magnetic circular dichroism (XMCD) and x-ray absorption near-edge structure (XANES) spectroscopy at the Pu M?,? edges of the ferromagnet PuSb are reported. Using bulk magnetization measurements and a sum rule analysis of the XMCD spectra, we determine the individual orbital [?L = 2.8(1)?B/Pu] and spin moments [?S = ?2.0(1)?B/Pu] of the Pu 5f electrons for the first time. Atomic multiplet calculations of the XMCD and XANES spectra reproduce well the experimental data and are consistent with the experimental value of the spin moment. These measurements of ?L_{z}? and ?S_{z}? are in excellent agreement with the values that have been extracted from neutron magnetic form factor measurements, and confirm the local character of the 5f electrons in PuSb. Finally, we demonstrate that a split M? as well as a narrow M? XMCD signal may serve as a signature of 5f electron localization in actinide compounds.
Ground-state wave function of plutonium in PuSb as determined via x-ray magnetic circular dichroism
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Janoschek, M.; Haskel, D.; Fernandez-Rodriguez, J.; van Veenendaal, M.; Rebizant, J.; Lander, G. H.; Zhu, J. -X.; Thompson, J. D.; Bauer, E. D.
2015-01-01T23:59:59.000Z
Measurements of x-ray magnetic circular dichroism (XMCD) and x-ray absorption near-edge structure (XANES) spectroscopy at the Pu M?,? edges of the ferromagnet PuSb are reported. Using bulk magnetization measurements and a sum rule analysis of the XMCD spectra, we determine the individual orbital [?L = 2.8(1)?B/Pu] and spin moments [?S = ?2.0(1)?B/Pu] of the Pu 5f electrons for the first time. Atomic multiplet calculations of the XMCD and XANES spectra reproduce well the experimental data and are consistent with the experimental value of the spin moment. These measurements of ?Lz? and ?Sz? are in excellent agreement with the values thatmore »have been extracted from neutron magnetic form factor measurements, and confirm the local character of the 5f electrons in PuSb. Finally, we demonstrate that a split M? as well as a narrow M? XMCD signal may serve as a signature of 5f electron localization in actinide compounds.« less
Atomic moments in Mn_{2}CoAl thin films analyzed by X-ray magnetic circular dichroism
Jamer, M. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics; Sterbinsky, G. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Assaf, B. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics; Arena, D. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Photon Sciences Directorate; Heiman, D. [Northwestern Univ., Evanston, IL (United States). Dept. of Physics
2014-12-05T23:59:59.000Z
Spin gapless semiconductors are known to be strongly affected by structural disorder when grown epitaxially as thin films. The magnetic properties of Mn_{2}CoAl thin films grown on GaAs (001) substrates are investigated here as a function of annealing. This study investigates the atomic-specific magnetic moments of Mn and Co atoms measured through X-ray magnetic circular dichroism as a function of annealing and the consequent structural ordering. The results indicate that the structural distortion mainly affects the Mn atoms as seen by the reduction of the magnetic moment from its predicted value. (auth)
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Thersleff, Thomas; Rusz, Jan; Rubino, Stefano; Hjörvarsson, Björgvin; Ito, Yasuo; J. Zaluzec, Nestor; Leifer, Klaus
2015-08-17T23:59:59.000Z
Understanding the ramifications of reduced crystalline symmetry on magnetic behavior is a critical step in improving our understanding of nanoscale and interfacial magnetism. However, investigations of such effects are often controversial largely due to the challenges inherent in directly correlating nanoscale stoichiometry and structure to magnetic behavior. Here, we describe how to use Transmission Electron Microscope (TEM) to obtain Electron Magnetic Circular Dichroism (EMCD) signals as a function of scattering angle to locally probe the magnetic behavior of thin oxide layers grown on an Fe (1 1 0) surface. Experiments and simulations both reveal a strong dependence of the magneticmore »orbital to spin ratio on its scattering vector in reciprocal space. We exploit this variation to extract the magnetic properties of the oxide cladding layer, showing that it locally may exhibit an enhanced orbital to spin moment ratio. This finding is supported here by both spatially and angularly resolved EMCD measurements, opening up the way for compelling investigations into how magnetic properties are affected by nanoscale features.« less
An analysis of the x-ray linear dichroism spectrum for NiO thin films grown on vicinal Ag(001)
Wu, Y.Z.
2008-01-01T23:59:59.000Z
dichroism spectrum for NiO thin films grown on vicinal Ag(Antiferromagnetic (AFM) NiO thin films are grown epitaxiallyXLD). We find that the NiO AFM spin exhibits an in- plane
van der Laan, G.; Edmonds, K. W.; Arenholz, E.; Farley, N. R. S.; Gallagher, B. L.
2010-03-30T23:59:59.000Z
We present a valence-state model to explain the characteristics of a recently observed pre-edge feature in Mn L{sub 3} x-ray magnetic circular dichroism (XMCD) of ferromagnetic (Ga,Mn)As and (Al,Ga,Mn)As thin films. The prepeak XMCD shows a uniaxial anisotropy, contrary to the cubic symmetry of the main structures induced by the crystalline electric field. Reversing the strain in the host lattice reverses the sign of the uniaxial anisotropy. With increasing carrier localization, the prepeak height increases, indicating an increasing 3d character of the hybridized holes. Hence, the feature is ascribed to transitions from the Mn 2p core level to unoccupied p-d hybridized valence states. The characteristics of the prepeak are readily reproduced by the model calculation taking into account the symmetry of the strain-, spin-orbit-, and exchange-split valence states around the zone center.
Mn l3,2 x-ray absorption spectroscopy and magnetic circular dichroism in ferromagnetic ga1-xmnxp
2008-01-01T23:59:59.000Z
pulsed-laser melting (II-PLM) [2]. Unlike the holes in thethe magnetic properties of II-PLM films are dominated by the
Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor
Coffey, Howard T. (Darien, IL)
1993-01-01T23:59:59.000Z
A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.
Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor
Coffey, H.T.
1993-10-19T23:59:59.000Z
A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.
Haskel, Daniel
- tention due to their potential for use in magnetic refrigeration.17 Among these materials, Gd5 SixGe1-x 4 transition,4,6 making them attractive candidates for magnetic refrigeration near room temperatureEffect of hydrostatic pressure upon the magnetic transitions in the Gd5,,SixGe1-x...4 giant
Novel Approach to Linear Accelerator Superconducting Magnet System
Kashikhin, Vladimir; /Fermilab
2011-11-28T23:59:59.000Z
Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.
Cryogen free superconducting splittable quadrupole magnet for linear accelerators
Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab
2011-09-01T23:59:59.000Z
A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.
One-electron linear systems in a strong magnetic field
J. C. Lopez V.; A. Turbiner
2000-01-19T23:59:59.000Z
Using a variational method we study a sequence of the one-electron atomic and molecular-type systems H, H_2^+, H_3^(2+) and H_4^(3+) in the presence of a homogeneous magnetic field ranging B = 0 - 4.414x10^{13} G. These systems are taken as a linear configuration aligned with the magnetic lines. For H_3^(2+) the potential energy surface has a minimum for B\\sim 10^{11} G which deepens with growth of the magnetic field strength (JETP Lett. 69, 844 (1999)); for B \\gtrsim 10^{12} G the minimum of the potential energy surface becomes sufficiently deep to have longitudinal vibrational state. We demonstrate that for the (ppppe) system the potential energy surface at B \\gtrsim 4.414x10^{13} G develops a minimum, indicating the possible existence of exotic molecular ion H_4^(3+). We find that for almost all accessible magnetic fields H_2^+ is the most bound one-electron linear system while for magnetic fields B \\gtrsim 10^{13} G the molecular ion H_3^(2+) becomes the most bound.
Zero-Field Dichroism in the Solar Chromosphere
R. Manso Sainz; J. Trujillo Bueno
2003-11-19T23:59:59.000Z
We explain the linear polarization of the Ca II infrared triplet observed close to the edge of the solar disk. In particular, we demonstrate that the physical origin of the enigmatic polarizations of the 866.2 nm and 854.2 nm lines lies in the existence of atomic polarization in their metastable lower levels, which produces differential absorption of polarization components (dichroism). To this end, we have solved the problem of the generation and transfer of polarized radiation by taking fully into account all the relevant optical pumping mechanisms in multilevel atomic models. We argue that `zero-field' dichroism may be of great diagnostic value in astrophysics.
Mn L3,2 X-ray absorption and magnetic circular dichroism in ferromagnetic Ga1-xMnxP
2006-01-01T23:59:59.000Z
and pulsed-laser melting (II-PLM) [2-4]. At 0.4 eV above thex P were synthesized by II-PLM [10]. GaP (001) wafers dopedthis material formed by II-PLM have shown that its magnetic
13th International Conference on Magnetically Levitated Systems and Linear Drives
Not Available
1993-09-01T23:59:59.000Z
This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.
Linear metric and temperature fluctuations of a charged plasma in a primordial magnetic field
Haba, Z
2015-01-01T23:59:59.000Z
We discuss tensor metric perturbations in a magnetic field around the homogeneous Juttner equilibrium of massless particles in an expanding universe. We solve the Liouville equation and derive the energy-momentum tensor up to linear terms in the metric and in the magnetic field.The term linear in the magnetic field is different from zero if the total charge of the primordial plasma is non-zero. We obtain an analytic formula for temperature fluctuations treating the tensor metric perturbations and the magnetic field as independent random variables. Assuming a cutoff on large momenta of the magnetic spectral function we show that the presence of the magnetic field can discriminate only low multipoles in the multipole expansion of temperature fluctuations. In such a case the term linear in the magnetic field can be more important than the quadratic one (corresponding to the fluctuations of the pure magnetic field).
MacKinnon, Angus
Two-dimensional electron gas in a linearly varying magnetic field: Quantization of the electron of electron and current densities. We investigate the case where the magnetic field varies linearly properties of a noninteracting electron gas in a linearly varying magnetic field, we consider the following
Superconducting magnets for SCRF cryomodules at front end of linear accelerators
Kashikhin, V.S.; Andreev, N.; Orlov, Y.; Orris, D.F.; Tartaglia, M.A.; /Fermilab
2010-05-01T23:59:59.000Z
Linear accelerators based on a superconducting technology need various superconducting magnets mounted inside SCRF Cryomodules. Relatively weak iron-dominated magnets are installed at the front end of linear accelerators. The focusing quadrupoles have integrated gradients in the range of 1-4 T, and apertures in the range 35-90 mm. Superconducting dipole correctors and quadrupoles were designed at Fermilab for various projects. In this paper these magnet designs, and test results of a fabricated dipole corrector, are presented. Also briefly discussed are magnetic and mechanical designs, quench protection, cooling, fabrication, and assembly into cryomodule.
ACTIVE SUSPENSION CONTROL WITH DIRECT-DRIVE TUBULAR LINEAR BRUSHLESS PERMANENT-MAGNET MOTOR
Lee, Seungho
2010-01-16T23:59:59.000Z
Recently, active suspension has been applied to many commercial automobiles. To develop the control algorithm for active suspension, a quarter-car test bed was built by using a direct-drive tubular linear brushless permanent-magnet motor (LBPMM...
5-loop Konishi from linearized TBA and the XXX magnet
Janos Balog; Arpad Hegedus
2010-06-08T23:59:59.000Z
Using the linearized TBA equations recently obtained in [arXiv:1002.1711] we show analytically that the 5-loop anomalous dimension of the Konishi operator agrees with the result obtained previously from the generalized Luscher formulae. The proof is based on the relation between this linear system and the XXX model TBA equations.
Improvement of the magnetic core for eddy current losses decreasing in cylindrical linear actuators.
Boyer, Edmond
Improvement of the magnetic core for eddy current losses decreasing in cylindrical linear actuators the power) increases, the iron losses become high [1]. One classical method for reducing the eddy current the eddy current losses in a longitudinal flux multi-rod actuator and to compute improvement. 2 The linear
Development of a Non-Magnetic Inertial Sensor for Vibration Stabilization in a Linear Collider
Frisch, Josef; Decker, Valentin; Doyle, Eric; Hendrickson, Linda; Himel, Thomas; Markiewicz, Thomas; Seryi, Andrei; /SLAC; Chang, Allison; Partridge, Richard; /Brown U.
2006-09-01T23:59:59.000Z
One of the options for controlling vibration of the final focus magnets in a linear collider is to use active feedback based on accelerometers. While commercial geophysics sensors have noise performance that substantially exceeds the requirements for a linear collider, they are physically large, and cannot operate in the strong magnetic field of the detector. Conventional nonmagnetic sensors have excessive noise for this application. We report on the development of a non-magnetic inertial sensor, and on a novel commercial sensor both of which have demonstrated the required noise levels for this application.
Design of magnetic mirrors for a linear theta pinch
Veglia, V. P.
1981-01-01T23:59:59.000Z
The problem of generating optimum magnetic mirror fields at the ends of a 50-cm long theta-pinch experiment to study particle flow and loss effects has been investigated. A combination of active and passive mirrors was developed to produce 2-3:1 fields for a 23-kG pinch. Biot-Savart and potential field prediction solutions for the magnetic field distribution were compared with experimental measurements in 2-5-cm long coils for the 50-cm long pinch.
A linear helicon plasma device with controllable magnetic field gradient
Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)
2012-06-15T23:59:59.000Z
Current free double layers (CFDLs) are localized potential structures having spatial dimensions - Debye lengths and potential drops of more than local electron temperature across them. CFDLs do not need a current for them to be sustained and hence they differ from the current driven double layers. Helicon antenna produced plasmas in an expanded chamber along with an expanding magnetic field have shown the existence of CFDL near the expansion region. A helicon plasma device has been designed, fabricated, and installed in the Institute for Plasma Research, India to study the role of maximum magnetic field gradient as well as its location with respect to the geometrical expansion region of the chamber in CFDL formation. The special feature of this machine consisting of two chambers of different radii is its capability of producing different magnetic field gradients near the physical boundary between the two chambers either by changing current in one particular coil in the direction opposite to that in other coils and/or by varying the position of this particular coil. Although, the machine is primarily designed for CFDL experiments, it is also capable of carrying out many basic plasma physics experiments such as wave propagation, wave coupling, and plasma instabilities in a varying magnetic field topology. In this paper, we will present the details of the machine construction, its specialties, and some preliminary results about the production and characterization of helicon plasma in this machine.
Melrose, Don
Quantum correction to the linear response for a magnetized electron gas D. B. Melrose and J. I. INTRODUCTION The linear response tensor for a magnetized, relativistic quantum electron gas was first magnetized electron plus positron gas reproduces its nonquantum counterpart. In the relativistic quantum case
Negative experimental evidence for magneto-orbital dichroism
Mathevet, Renaud; Pruvost, Laurence; Rikken, Geert L J A
2012-01-01T23:59:59.000Z
A light beam can carry both spin angular momentum (SAM) and orbital angular momentum (OAM). SAM is commonly evidenced by circular dichroism (CD) experiments i. e. differential absorption of left and right-handed circularly polarized light. Recent experiments, supported by theoretical work, indicate that the corresponding effect with OAM instead of SAM is not observed in chiral matter. Isotropic materials can show CD when subjected to a magnetic field (MCD). We report a set of experiments, under well defined conditions, searching for magnetic orbital dichroism (MOD), differential absorption of light as a function of the sign of its OAM. We experimentally demonstrate that this effect, if any, is smaller than a few 10^{-4} of MCD for the Nd:YAG ^4I_{9/2} ^4F_{5/2} transition. This transition is essentially of electric dipole nature. We give an intuitive argument suggesting that the lowest order of light matter interaction leading to MOD is the electric quadrupole term.
Spin-Induced Polarizations and Directional Dichroism of Multiferroic BiFeO3.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Fishman, Randy Scott; Lee, Jun Hee; Bordacs, S.; Kezsmarki, I.; Nagel, U.; Room, T.
2015-09-14T23:59:59.000Z
A microscopic model for the room-temperature multiferroic BiFeO3 that includes two Dzyaloshinskii-Moriya interactions and single-ion anisotropy along the ferroelectric polarization predicts both the zero-field spectroscopic modes as well as their splitting and evolution in a magnetic field. Due to simultaneously broken time-reversal and spatial-inversion symmetries, the absorption of light changes as the magnetic field or the direction of light propagation is reversed. We discuss three physical mechanisms that may contribute to this absorption asymmetry known as directional dichroism: the spin current, magnetostriction, and single-ion anisotropy. We conclude that the directional dichroism in BiFeO3 is dominated by the spin-current polarization andmore »is insensitive to the magnetostriction and easy-axis anisotropy. With three independent spin-current parameters, our model accurately describes the directional dichroism observed for magnetic field along [1, 1, 0]. Since some modes are almost transparent to light traveling in one direction but opaque for light traveling in the opposite direction, BiFeO3 can be used as a room-temperature optical diode at certain frequencies in the GHz to THz range. Our work demonstrates that an analysis of the directional dichroism spectra based on an effective spin model supplemented by first-principles calculations can produce a quantitative microscopic theory of the magnetoelectric couplings in multiferroic materials.« less
Calculation of cogging force in a novel slotted linear tubular brushless permanent magnet motor
Zhu, Z.Q.; Hor, P.J.; Howe, D. [Univ. of Sheffield (United Kingdom). Dept. of Electronic and Electrical Engineering] [Univ. of Sheffield (United Kingdom). Dept. of Electronic and Electrical Engineering; Rees-Jones, J. [Unilever Research Port Sunlight Lab., Bebington (United Kingdom)] [Unilever Research Port Sunlight Lab., Bebington (United Kingdom)
1997-09-01T23:59:59.000Z
There is an increasing requirement for controlled linear motion over short and long strokes, in the factory automation and packaging industries, for example. Linear brushless PM motors could offer significant advantages over conventional actuation technologies, such as motor driven cams and linkages and pneumatic rams--in terms of efficiency, operating bandwidth, speed and thrust control, stroke and positional accuracy, and indeed over other linear motor technologies, such as induction motors. Here, a finite element/analytical based technique for the prediction of cogging force in a novel topology of slotted linear brushless permanent magnet motor has been developed and validated. The various force components, which influence cogging are pre-calculated by the finite element analysis of some basic magnetic structures, facilitate the analytical synthesis of the resultant cogging force. The technique can be used to aid design for the minimization of cogging.
Oldest Known Magnet's Secrets Revealed Under High Pressures ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
dichroism technique is readily applied to most magnetic materials without the need for isotope enrichment, and provides a true measure of long-range magnetic order." Other...
Non-linear dynamics of Kelvin-Helmholtz unstable magnetized jets three-dimensional effects
Keppens, R
1999-01-01T23:59:59.000Z
A numerical study of the Kelvin-Helmholtz instability in compressible magnetohydrodynamics is presented. The three-dimensional simulations consider shear flow in a cylindrical jet configuration, embedded in a uniform magnetic field directed along the jet axis. The growth of linear perturbations at specified poloidal and axial mode numbers demonstrate intricate non-linear coupling effects. The physical mechanims leading to induced secondary Kelvin-Helmholtz instabilities at higher mode numbers are identified. The initially weak magnetic field becomes locally dominant in the non-linear dynamics before and during saturation. Thereby, it controls the jet deformation and eventual breakup. The results are obtained using the Versatile Advection Code [G. Toth, Astrophys. Lett. Comm. 34, 245 (1996)], a software package designed to solve general systems of conservation laws. An independent calculation of the same Kelvin-Helmholtz unstable jet configuration using a three-dimensional pseudo-spectral code gives important ...
Linear beam raster magnet driver based on H-bridge technique
Sinkine, Nikolai I.; Yan, Chen; Apeldoorn, Cornelis; Dail, Jeffrey Glenn; Wojcik, Randolph Frank; Gunning, William
2006-06-06T23:59:59.000Z
An improved raster magnet driver for a linear particle beam is based on an H-bridge technique. Four branches of power HEXFETs form a two-by-two switch. Switching the HEXFETs in a predetermined order and at the right frequency produces a triangular current waveform. An H-bridge controller controls switching sequence and timing. The magnetic field of the coil follows the shape of the waveform and thus steers the beam using a triangular rather than a sinusoidal waveform. The system produces a raster pattern having a highly uniform raster density distribution, eliminates target heating from non-uniform raster density distributions, and produces higher levels of beam current.
Analytical modeling of a new disc permanent magnet linear synchronous machine for electric vehicles
Liu, C.T.; Chen, J.W.; Su, K.S.
1999-09-01T23:59:59.000Z
This paper develops an analytical approach based on a qd0 reference frame model to analyze dynamic and steady state characteristics of disc permanent magnet linear synchronous machines (DPMLSMs). The established compact mathematical model can be more easily employed to analyze the system behavior and to design the controller. Superiority in operational electromagnetic characteristics of the proposed DPMLSM for electric vehicle (EV) applications is verified by both numerical simulations and experimental investigations.
Non-linear dynamics of Kelvin-Helmholtz unstable magnetized jets: three-dimensional effects
R. Keppens; G. Toth
1999-01-27T23:59:59.000Z
A numerical study of the Kelvin-Helmholtz instability in compressible magnetohydrodynamics is presented. The three-dimensional simulations consider shear flow in a cylindrical jet configuration, embedded in a uniform magnetic field directed along the jet axis. The growth of linear perturbations at specified poloidal and axial mode numbers demonstrate intricate non-linear coupling effects. The physical mechanims leading to induced secondary Kelvin-Helmholtz instabilities at higher mode numbers are identified. The initially weak magnetic field becomes locally dominant in the non-linear dynamics before and during saturation. Thereby, it controls the jet deformation and eventual breakup. The results are obtained using the Versatile Advection Code [G. Toth, Astrophys. Lett. Comm. 34, 245 (1996)], a software package designed to solve general systems of conservation laws. An independent calculation of the same Kelvin-Helmholtz unstable jet configuration using a three-dimensional pseudo-spectral code gives important insights into the coupling and excitation events of the various linear mode numbers.
Study of plasma dynamics affected by a global magnetic field in linear wire array Z pinches
Hu Min; Kusse, Bruce R. [Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)
2005-10-01T23:59:59.000Z
In the experiments described in this paper a linear wire array composed of several wires (e.g., four wires) was viewed as a small portion of a large cylindrical array. Comparing to cylindrical arrays, linear wire arrays have relatively simple geometry and therefore are much easier to diagnose. To simulate the global magnetic field present in a cylindrical array, a return current conductor was positioned near the linear wire array. A global magnetic field in the tens of Tesla was produced by the return current in the vicinity of the linear array. The plasma dynamics affected by the global magnetic field was studied using shearing interferometry and x-ray backlighting techniques. Experimental results on tungsten wire arrays (four wires, 1.4 cm long, 12.7 {mu}m diameter, 1 mm interwire gaps) are discussed. Current transfer from wire cores to the surrounding corona plasmas appeared to happen at around 10 ns relative to the start of the current pulse. After that, some of the wire plasma was swept away from the wire cores by the JxB force and formed a localized, high-density peak (precursor plasma). The motion of the precursor plasma was observed to accelerate for about 20 ns, indicating that current was present inside the precursor plasma during this time range. Using an x-ray backlighter and a laser interferometer, the resumption of wire core expansion, major mass ablation, and the termination of precursor plasma acceleration were observed to occur at 32-34 ns. These effects can be interpreted as evidence of the transfer of the current back to the wire cores from the precursor plasma.
Beam-turning magnet design and test for the Recirculating Linear Accelerator
Crow, J.T. (Sandia National Labs., Albuquerque, NM (United States)); Platt, R.C. (Science Applications International Corp., San Diego, CA (United States))
1991-01-01T23:59:59.000Z
We have designed and tested a system for applying a ramped vertical magnetic field for turning the electron beam in the IFR Recirculating Linear Accelerator. The field is highly uniform over two Gaussian beam radii, and can be adjusted for a large radial gradient for increased energy bandwidth. The system includes shielding of the current-carrying rods to protect the pulser from REB induced fields and to reduce the effect of REB images on the beam transport to negligible levels. The system has been tested on the IBEX accelerator with > 95% peak current transport and > 90% charge transport through a 90{degree} turn. 2 refs., 6 figs.
Mix, C.; Finizio, S.; Jakob, G.; Kläui, M. [Institut für Physik, Johannes Gutenberg Universität Mainz, Staudingerweg 7, D-55128 Mainz (Germany); Buzzi, M.; Nolting, F. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Kronast, F. [Helmholtz-Zentrum-Berlin für Materialien und Energie GmbH, Albert-Einstein Straße 15, D-12489 Berlin (Germany)
2014-05-21T23:59:59.000Z
Low-thickness La{sub 0.66}Sr{sub 0.34}MnO{sub 3} (LSMO)/BiFeO{sub 3} (BFO) thin film samples deposited on SrTiO{sub 3} were imaged by high resolution x-ray microscopy at different temperatures. The ultra-thin thickness of the top layer allows to image both the ferromagnetic domain structure of LSMO and the multiferroic domain structure of the buried BFO layer, opening a path to a direct observation of coupling at the interface on a microscopic level. By comparing the domain size and structure of the BFO and LSMO, we observed that, in contrast to LSMO single layers, LSMO/BFO multilayers show a strong temperature dependence of the ferromagnetic domain structure of the LSMO. Particularly, at 40?K, a similar domain size for BFO and LSMO is observed. This indicates a persistence of exchange coupling on the microscopic scale at a temperature, where the exchange bias as determined by magnetometer measurements is vanishing.
Three-dimensional linear peeling-ballooning theory in magnetic fusion devices
Weyens, T., E-mail: tweyens@fis.uc3m.es; Sánchez, R.; García, L. [Departamento de Física, Universidad Carlos III de Madrid, Madrid 28911 (Spain)] [Departamento de Física, Universidad Carlos III de Madrid, Madrid 28911 (Spain); Loarte, A.; Huijsmans, G. [ITER Organization, Route de Vinon sur Verdon, 13067 Saint Paul Lez Durance (France)] [ITER Organization, Route de Vinon sur Verdon, 13067 Saint Paul Lez Durance (France)
2014-04-15T23:59:59.000Z
Ideal magnetohydrodynamics theory is extended to fully 3D magnetic configurations to investigate the linear stability of intermediate to high n peeling-ballooning modes, with n the toroidal mode number. These are thought to be important for the behavior of edge localized modes and for the limit of the size of the pedestal that governs the high confinement H-mode. The end point of the derivation is a set of coupled second order ordinary differential equations with appropriate boundary conditions that minimize the perturbed energy and that can be solved to find the growth rate of the perturbations. This theory allows of the evaluation of 3D effects on edge plasma stability in tokamaks such as those associated with the toroidal ripple due to the finite number of toroidal field coils, the application of external 3D fields for elm control, local modification of the magnetic field in the vicinity of ferromagnetic components such as the test blanket modules in ITER, etc.
M. K. Georgoulis; Barry J. LaBonte
2007-06-27T23:59:59.000Z
We self-consistently derive the magnetic energy and relative magnetic helicity budgets of a three-dimensional linear force-free magnetic structure rooted in a lower boundary plane. For the potential magnetic energy we derive a general expression that gives results practically equivalent to those of the magnetic Virial theorem. All magnetic energy and helicity budgets are formulated in terms of surface integrals applied to the lower boundary, thus avoiding computationally intensive three-dimensional magnetic field extrapolations. We analytically and numerically connect our derivations with classical expressions for the magnetic energy and helicity, thus presenting a so-far lacking unified treatment of the energy/helicity budgets in the constant-alpha approximation. Applying our derivations to photospheric vector magnetograms of an eruptive and a noneruptive solar active regions, we find that the most profound quantitative difference between these regions lies in the estimated free magnetic energy and relative magnetic helicity budgets. If this result is verified with a large number of active regions, it will advance our understanding of solar eruptive phenomena. We also find that the constant-alpha approximation gives rise to large uncertainties in the calculation of the free magnetic energy and the relative magnetic helicity. Therefore, care must be exercised when this approximation is applied to photospheric magnetic field observations. Despite its shortcomings, the constant-alpha approximation is adopted here because this study will form the basis of a comprehensive nonlinear force-free description of the energetics and helicity in the active-region solar corona, which is our ultimate objective.
Thomas Wiegelmann; Bernd Inhester; Bernhard Kliem; Gherardo Valori; Thomas Neukirch
2006-12-21T23:59:59.000Z
CONTEXT: As the coronal magnetic field can usually not be measured directly, it has to be extrapolated from photospheric measurements into the corona. AIMS: We test the quality of a non-linear force-free coronal magnetic field extrapolation code with the help of a known analytical solution. METHODS: The non-linear force-free equations are numerically solved with the help of an optimization principle. The method minimizes an integral over the force-free and solenoidal condition. As boundary condition we use either the magnetic field components on all six sides of the computational box in Case I or only on the bottom boundary in Case II. We check the quality of the reconstruction by computing how well force-freeness and divergence-freeness are fulfilled and by comparing the numerical solution with the analytical solution. The comparison is done with magnetic field line plots and several quantitative measures, like the vector correlation, Cauchy Schwarz, normalized vector error, mean vector error and magnetic energy. RESULTS: For Case I the reconstructed magnetic field shows good agreement with the original magnetic field topology, whereas in Case II there are considerable deviations from the exact solution. This is corroborated by the quantitative measures, which are significantly better for Case I. CONCLUSIONS: Despite the strong nonlinearity of the considered force-free equilibrium, the optimization method of extrapolation is able to reconstruct it; however, the quality of reconstruction depends significantly on the consistency of the input data, which is given only if the known solution is provided also at the lateral and top boundaries, and on the presence or absence of flux concentrations near the boundaries of the magnetogram.
Crawford, Anthony C
2014-01-01T23:59:59.000Z
This note presents measurements that support the conclusion that it is feasible to achieve magnetic field values at the level of 5 milliGauss for a cryomodule in a realistic and representative ambient magnetic field environment.
The First International Workshop on Synchrotron Radiation Circular Dichroism
Wallace, Bonnie Ann
The First International Workshop on Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy Sauerborn (BESSY2, Germany), Professor Alberto Spisni (LNLS, Brazil) and Dr. Zhang Guobin (NSRL, China REPORTS SYNCHROTRON RADIATION NEWS, Vol. 15, No. 1, 2002 33 1st International Workshop on SRCD
Abdel Nasser Tawfik; Niseem Magdy
2015-01-06T23:59:59.000Z
Effects of external magnetic field on various properties of the quantum chromodynamics under extreme conditions of temperature and density have been analysed. To this end, we use SU(3) Polyakov linear sigma-model and assume that the external magnetic field eB adds some restrictions to the quarks energy due to the existence of free charges in the plasma phase. In doing this, we apply the Landau theory of quantization. This requires an additional temperature to drive the system through the chiral phase-transition. Accordingly, the dependence of the critical temperature of chiral and confinement phase-transitions on the magnetic field is characterized. Based on this, we have studied the thermal evolution of thermodynamic quantities and the first four higher-order moment of particle multiplicity. Having all these calculations, we have studied the effects of magnetic field on chiral phase-transition. We found that both critical temperature T_c and critical chemical potential increase with increasing the magnetic field eB. Last but not least, the magnetic effects of the thermal evolution of four scalar and four pseudoscalar meson states are studied. We concluded that the meson masses decrease as the temperature increases till T_c. Then, the vacuum effect becomes dominant and rapidly increases with the temperature T. At low T, the scalar meson masses normalized to the lowest Matsubara frequency rapidly decreases as T increases. Then, starting from T_c, we find that the thermal dependence almost vanishes. Furthermore, the meson masses increase with increasing magnetic field. This gives characteristic phase diagram of T vs. external magnetic field $B. At high T, we find that the masses of almost all meson states become temperature independent. It is concluded that the various meson states likely have different T_c's.
Circular dichroism in core-level emission from O/W(110): Experiment and theory
Daimon, H. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); [Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0101 (Japan); Ynzunza, R.X.; Palomares, F.J.; Tober, E.D.; Wang, Z.X.; Kaduwela, A.P. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); [Physics Department, University of California at Davis, Davis, California 95616 (United States); Van Hove, M.A. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fadley, C.S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); [Physics Department, University of California at Davis, Davis, California 95616 (United States)
1998-10-01T23:59:59.000Z
Circular dichroism has been observed in the photoelectron diffraction of chemically shifted W 4f photoelectrons from the W(110)1{times}1-O surface. The diffraction peaks from first-layer W atoms bonded most directly to oxygen showed an azimuthal rotation similar to those reported in a prior experiment on Si(001). The maximum rotation angles are also in good agreement with those calculated using the formula {Delta}{phi}=m/kRthinspsin{sup 2}{theta} derived previously by Daimon {ital et al.} [Jpn. J. Appl. Phys., Part 2 {bold 32}, L1480 (1993)] and assuming m=4, which is the maximum magnetic quantum number of the photoelectron wave function. {copyright} {ital 1998} {ital The American Physical Society}
ACTIVE SUSPENSION CONTROL WITH DIRECT-DRIVE TUBULAR LINEAR BRUSHLESS PERMANENT-MAGNET MOTOR
Lee, Seungho
2010-01-16T23:59:59.000Z
Recently, active suspension has been applied to many commercial automobiles. To develop the control algorithm for active suspension, a quarter-car test bed was built by using a direct-drive tubular linear brushless ...
Dichroism and birefringence of natural violet diamond crystals
Konstantinova, A. F. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: afkonst@ns.crys.ras.ru; Titkov, S. V. [Russian Academy of Sciences, Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (Russian Federation); Imangazieva, K. B. [Issyk Kul State University (Kyrgyzstan); Evdishchenko, E. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Sergeev, A. M. [Karpov Institute of Physical Chemistry, State Scientific Center of the Russian Federation (Russian Federation); Zudin, N. G. [OOO Roni Kerob (Russian Federation); Orekhova, V. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)
2006-05-15T23:59:59.000Z
Investigation of the optical properties of natural violet diamonds from the Yakutian kimberlites is performed. A red shift of the absorption edge is revealed in the absorption spectra of these crystals. This shift is indicative of the presence of a high concentration of nitrogen in the diamonds studied. Along with the strong band at 0.550 {mu}m, weaker bands at 0.390, 0.456 and 0.496 {mu}m are revealed. It is shown that violet diamond crystals have birefringence and dichroism of about 10{sup -5} and 10{sup -6}, respectively. When a light beam propagates perpendicularly to colored lamellas, the dichroism is much larger and the birefringence is smaller than in the case where the beam direction is parallel to lamellas.
Non-linear viscoelastic response of magnetic fiber suspensions in oscillatory shear P. Kuzhira*
Paris-Sud XI, Université de
of 37 µm and diameter of 4.9 µm, dispersed in a silicon oil. Rheological measurements have been carried showed a high-frequency plateau, typical for Maxwell behavior. Our simple single relaxation time model. The magnetic fiber suspensions have shown better sedimentation stability [4
Crenshaw, Michael E., E-mail: michael.e.crenshaw4.civ@mail.mil [US Army Aviation and Missile Research, Development, and Engineering Center, Redstone Arsenal, Alabama 35898 (United States)
2014-04-15T23:59:59.000Z
In a continuum setting, the energy–momentum tensor embodies the relations between conservation of energy, conservation of linear momentum, and conservation of angular momentum. The well-defined total energy and the well-defined total momentum in a thermodynamically closed system with complete equations of motion are used to construct the total energy–momentum tensor for a stationary simple linear material with both magnetic and dielectric properties illuminated by a quasimonochromatic pulse of light through a gradient-index antireflection coating. The perplexing issues surrounding the Abraham and Minkowski momentums are bypassed by working entirely with conservation principles, the total energy, and the total momentum. We derive electromagnetic continuity equations and equations of motion for the macroscopic fields based on the material four-divergence of the traceless, symmetric total energy–momentum tensor. We identify contradictions between the macroscopic Maxwell equations and the continuum form of the conservation principles. We resolve the contradictions, which are the actual fundamental issues underlying the Abraham–Minkowski controversy, by constructing a unified version of continuum electrodynamics that is based on establishing consistency between the three-dimensional Maxwell equations for macroscopic fields, the electromagnetic continuity equations, the four-divergence of the total energy–momentum tensor, and a four-dimensional tensor formulation of electrodynamics for macroscopic fields in a simple linear medium.
Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device
Peng, S.Y.
1991-07-01T23:59:59.000Z
Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system ({rho},{xi}) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number {alpha} as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions.
Vlasov Fluid stability of a 2-D plasma with a linear magnetic field null
Kim, J.S.
1984-01-01T23:59:59.000Z
Vlasov Fluid stability of a 2-dimensional plasma near an O type magnetic null is investigated. Specifically, an elongated Z-pinch is considered, and applied to Field Reversed Configurations at Los Alamos National Laboratory by making a cylindrical approximation of the compact torus. The orbits near an elliptical O type null are found to be very complicated; the orbits are large and some are stochastic. The kinetic corrections to magnetohydrodynamics (MHD) are investigated by evaluating the expectation values of the growth rates of a Vlasov Fluid dispersion functional by using a set of trial functions based on ideal MHD. The dispersion functional involves fluid parts and orbit dependent parts. The latter involves phase integral of two time correlations. The phase integral is replaced by the time integral both for the regular and for the stochastic orbits. Two trial functions are used; one has a large displacement near the null and the other away from the null.
Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of); Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)] [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)
2014-03-15T23:59:59.000Z
Linear and nonlinear propagation of dust-acoustic waves in a magnetized strongly coupled dusty plasma is theoretically investigated. The normal mode analysis (reductive perturbation method) is employed to investigate the role of ambient/external magnetic field, obliqueness, and effective electrostatic dust-temperature in modifying the properties of linear (nonlinear) dust-acoustic waves propagating in such a strongly coupled dusty plasma. The effective electrostatic dust-temperature, which arises from strong electrostatic interactions among highly charged dust, is considered as a dynamical variable. The linear dispersion relation (describing the linear propagation characteristics) for the obliquely propagating dust-acoustic waves is derived and analyzed. On the other hand, the Korteweg-de Vries equation describing the nonlinear propagation of the dust-acoustic waves (particularly, propagation of dust-acoustic solitary waves) is derived and solved. It is shown that the combined effects of obliqueness, magnitude of the ambient/external magnetic field, and effective electrostatic dust-temperature significantly modify the basic properties of linear and nonlinear dust-acoustic waves. The results of this work are compared with those observed by some laboratory experiments.
Protein Characterisation by Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy
Wallace, B.
2009-01-01T23:59:59.000Z
Circular dichroism (CD) spectroscopy is a well-established technique for the study of proteins. Synchrotron radiation circular dichroism (SRCD) spectroscopy extends the utility of conventional CD spectroscopy (i.e. using laboratory-based instruments) because the high light flux from a synchrotron enables collection of data to lower wavelengths, detection of spectra with higher signal-to-noise levels and measurements in the presence of strongly absorbing non-chiral components such as salts, buffers, lipids and detergents. This review describes developments in instrumentation, methodologies and bioinformatics that have enabled new applications of the SRCD technique for the study of proteins. It includes examples of the use of SRCD spectroscopy for providing static and dynamic structural information on molecules, including determinations of secondary structures of intact proteins and domains, assessment of protein stability, detection of conformational changes associated with ligand and drug binding, monitoring of environmental effects, examination of the processes of protein folding and membrane insertion, comparisons of mutant and modified proteins, identification of intermolecular interactions and complex formation, determination of the dispositions of proteins in membranes, identification of natively disordered proteins and their binding partners and examination of the carbohydrate components of glycoproteins. It also discusses how SRCD can be used in conjunction with macromolecular crystallography and other biophysical techniques to provide a more complete picture of protein structures and functions, including how proteins interact with other macromolecules and ligands. This review also includes a discussion of potential new applications in structural and functional genomics using SRCD spectroscopy and future instrumentation and bioinformatics developments that will enable such studies. Finally, the appendix describes a number of computational/bioinformatics resources for secondary structure analyses that take advantage of the improved data quality available from SRCD. In summary, this review discusses how SRCD can be used for a wide range of structural and functional studies of proteins.
Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular
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Hitchcock, Adam P.
with results from Nephila clavipes dragline spider silk measured using the in situ rotation device. © 2007
Mossbauer Spectroscopy as a Probe of Magnetization Dynamics in the Linear Iron(I) and Iron States *S Supporting Information ABSTRACT: The iron-57 Mossbauer spectra of the linear, two. Because of the lifetime of the measurement (10-8 to 10-9 s), iron-57 Mossbauer spectros- copy yielded
Mi, Chunting "Chris"
and the armature windings are on the stator while the rotor is the same as a SRM. Hence, it offers the ad- vantage permanent magnet (LDSPM) motor is particularly suitable for long stator applications due to its simple and low cost stator, which consists of only iron. This paper proposes a new LDSPM motor design
Azimuth ambiguity removal and non-linear force-free extrapolation of near-limb magnetic regions
Rudenko, G V; Anfnogentov, S A
2010-01-01T23:59:59.000Z
Possibilities in principle for satisfactory removal of the 180-azimuthal ambiguity in the transverse field of vector magnetograms and the extrapolation of magnetic fields independently of their position on the solar disk are shown. Revealed here is an exact correspondence between the estimated field and the nonpotential loop structure on the limb. The Metropolis's algorithm modified to work in spherical geometry is used to resolve the azimuthal ambiguity. Based on a version of the optimization method from Rudenko and Myshyakov (2009), we use corrected magnetograms as boundary conditions for magnetic field extrapolation in the nonlinear force-free approximation.
Investigations of Magnetic Overlayers at the Advanced Photon Source
Tobin, J G; Yu, S; Butterfield, M T
2009-06-26T23:59:59.000Z
Magnetic overlayers of Fe and Co have been investigated with X-ray Magnetic Circular Dichroism in X-ray Absorption Spectroscopy (XMCD-ABS) and Photoelectron Spectroscopy (PES), including Spin-Resolved Photoelectron Spectroscopy (SRPES), at Beamline 4 at the Advanced Photon Source (APS). Particular emphasis was placed upon the interrogation of the 2p levels of the Fe.
Schleyer, F.; Cairns, Iver H. [School of Physics, University of Sydney, NSW 2006 (Australia); Kim, E.-H. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2013-03-15T23:59:59.000Z
Linear mode conversion (LMC) is the linear transfer of energy from one wave mode to another in an inhomogeneous plasma. It is relevant to laboratory plasmas and multiple solar system radio emissions, such as continuum radiation from planetary magnetospheres and type II and III radio bursts from the solar corona and solar wind. This paper simulates LMC of waves defined by warm, magnetized fluid theory, specifically the conversion of Langmuir/z-mode waves to electromagnetic (EM) radiation. The primary focus is the calculation of the energy and power conversion efficiencies for LMC as functions of the angle of incidence {theta} of the Langmuir/z-mode wave, temperature {beta}=T{sub e}/m{sub e}c{sup 2}, adiabatic index {gamma}, and orientation angle {phi} between the ambient density gradient {nabla}N{sub 0} and ambient magnetic field B{sub 0} in a warm, unmagnetized plasma. The ratio of these efficiencies is found to agree well as a function of {theta}, {gamma}, and {beta} with an analytical relation that depends on the group speeds of the Langmuir/z and EM wave modes. The results demonstrate that the energy conversion efficiency {epsilon} is strongly dependent on {gamma}{beta}, {phi} and {theta}, with {epsilon}{proportional_to}({gamma}{beta}){sup 1/2} and {theta}{proportional_to}({gamma}{beta}){sup 1/2}. The power conversion efficiency {epsilon}{sub p}, on the other hand, is independent of {gamma}{beta} but does vary significantly with {theta} and {phi}. The efficiencies are shown to be maximum for approximately perpendicular density gradients ({phi} Almost-Equal-To 90 Degree-Sign ) and minimal for parallel orientation ({phi}=0 Degree-Sign ) and both the energy and power conversion efficiencies peak at the same {theta}.
B Wallace; R Janes
2011-12-31T23:59:59.000Z
CD (circular dichroism) spectroscopy is a well-established technique in structural biology. SRCD (synchrotron radiation circular dichroism) spectroscopy extends the utility and applications of conventional CD spectroscopy (using laboratory-based instruments) because the high flux of a synchrotron enables collection of data at lower wavelengths (resulting in higher information content), detection of spectra with higher signal-to-noise levels and measurements in the presence of absorbing components (buffers, salts, lipids and detergents). SRCD spectroscopy can provide important static and dynamic structural information on proteins in solution, including secondary structures of intact proteins and their domains, protein stability, the differences between wild-type and mutant proteins, the identification of natively disordered regions in proteins, and the dynamic processes of protein folding and membrane insertion and the kinetics of enzyme reactions. It has also been used to effectively study protein interactions, including protein-protein complex formation involving either induced-fit or rigid-body mechanisms, and protein-lipid complexes. A new web-based bioinformatics resource, the Protein Circular Dichroism Data Bank (PCDDB), has been created which enables archiving, access and analyses of CD and SRCD spectra and supporting metadata, now making this information publicly available. To summarize, the developing method of SRCD spectroscopy has the potential for playing an important role in new types of studies of protein conformations and their complexes.
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Remote Sensing of Chromospheric Magnetic Fields via the Hanle and Zeeman Effects
J. Trujillo Bueno; R. Manso Sainz
2007-11-16T23:59:59.000Z
The only way to obtain reliable empirical information on the intensity and topology of the weak magnetic fields of the quiet solar chromosphere is via the measurement and rigorous physical interpretation of polarization signals in chromospheric spectral lines. The observed Stokes profiles reported here are due to the Hanle and Zeeman effects operating in a weakly magnetized plasma that is in a state far from local thermodynamic equilibrium. The physical origin of their enigmatic linear polarization Q and U components is the existence of atomic polarization in their metastable lower-levels, which permits the action of a dichroism mechanism that has nothing to do with the transverse Zeeman effect. It is also pointed out that the population imbalances and coherences among the Zeeman sublevels of such long-lived atomic levels can survive in the presence of horizontal magnetic fields having intensities in the gauss range, and produce significant polarization signals. Finally, it is shown how the most recent developments in the observation and theoretical modelling of weak polarization signals are facilitating fundamental new advances in our ability to investigate the magnetism of the outer solar atmosphere via spectropolarimetry.
Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux
2006-07-17T23:59:59.000Z
The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known $\\overrightarrow{v}\\times \\overrightarrow{E}$ field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. \\QTR{bf}{59}, 1077 (1991), Pendlebury, JM \\QTR{em}{et al;} Phys. Rev. \\QTR{bf}{A70}, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift (Lamoreaux, SK and Golub, R; Phys. Rev \\QTR{bf}{A71}, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.
Colossal anisotropy of the magnetic properties of doped lithium nitrodometalates
Antropov, Vladimir P [Ames Laboratory; Antonov, Victor N [Ames Laboratory
2014-09-01T23:59:59.000Z
We present a first-principles investigation of the electronic structure and physical properties of doped lithium nitridometalates Li2(Li1?xMx)N (LiMN) with M = Cr, Mn, Fe, Co, and Ni. The diverse properties include the equilibrium magnetic moments, magneto-crystalline anisotropy, magneto-optical Kerr spectra, and x-ray magnetic circular dichroism. We explain the colossal magnetic anisotropy in LiFeN by its unique electronic structure which ultimately leads to a series of unusual physical properties. The most unique property is a complete suppression of relativistic effects and freezing of orbital moments for in-plane orientation of the magnetization. This leads to the colossal spatial anisotropy of many magnetic properties including energy, Kerr, and dichroism effects. LiFeN is identified as an ultimate single-ion anisotropy system where a nearly insulating state can be produced by a spin orbital coupling alone. A very nontrivial strongly fluctuating and sign changing character of the magnetic anisotropy with electronic 3d-atomic doping is predicted theoretically. A large and highly anisotropic Kerr effect due to the interband transitions between atomic-like Fe 3d bands is found for LiFeN. A giant anisotropy of the x-ray magnetic circular dichroism for the Fe K spectrum and a very weak one for the Fe L2,3 spectra in LiFeN are also predicted.
Wallace,B.
2005-01-01T23:59:59.000Z
Circular dichroism (CD) spectroscopy has been employed for more than 50 years for the study of the structure and dynamics of proteins. It is now a workhorse of structural biology, finding applications in the determination of protein secondary structures, monitoring and deciphering protein folding, examining macromolecular interactions, and defining and quantitating protein-ligand binding. For the most part, CD studies have used laboratory-based instruments to measure electronic transitions in the far (190-250 nm), near ultraviolet (UV) (250-300 nm) and visible (> 400 nm) wavelength ranges, which have enabled studies of polypeptide backbones, aromatic amino acids and colored chromophores, respectively. Additional transitions exist at lower wavelengths in the vacuum ultraviolet (VUV) region (<190 nm); however, these transitions tend to be inaccessible to conventional CD instruments, due to the low intensity of their Xenon arc lamp light sources at wavelengths below190 nm. In 1980, the first synchrotron-based CD instruments were constructed, which took advantage of the high photon flux available from synchrotron light sources at these wavelengths. However, the technique of synchrotron radiation circular dichroism (SRCD) did not really take off until enabling studies had been done to show that additional data were obtainable for proteins in the VUV region, that these data were readily accessible with modern beamlines, and most importantly, that new applications of these data existed in structural molecular biology.
Jr, Peter Chien; Rosenman, Karla; Cheung, Wang; Wang, Nadia; Sanchez, Miguel
2009-01-01T23:59:59.000Z
type 1/type 2 mosaic of psoriasis? Dermatology 2006; 212:Magalhaes RF, et al. Linear psoriasis in Brazilian childrensuffering from linear psoriasis along lines of Blaschko. Br
Kumar, Punith V., E-mail: drvldayal@gmail.com; Manju, M. R., E-mail: drvldayal@gmail.com; Dayal, Vijaylakshmi, E-mail: drvldayal@gmail.com [Department of Physics, Maharaja Institute of Technology, Mysore-571438, Karnataka (India)
2014-04-24T23:59:59.000Z
We present a comprehensive study on origin of Spin Glass (SG) property in polycrystalline La{sub 0.5}Bi{sub 0.5}MnO{sub 3} perovskite oxide using linear and higher order ac susceptibility (?) measurements. The third order harmonic susceptibility (?{sub 3}) vs. temperature (K) with varying magnetic fields from 0.95 to 9.45 Oe and the divergence in their ?{sub 3} (max) allows us to infer the SG behavior occurring in the sample possibly due to co-operative freezing of the spins.
Linear Dependence and Linear Independence
PRETEX (Halifax NS) #1 1054 1999 Mar 05 10:59:16
2010-02-12T23:59:59.000Z
Feb 16, 2007 ... Observe that the vector (1, 2) is already a linear combination of (1, 0) and (0, 1), and therefore it does not add any new vectors to the linear span ...
Shaon Sahoo; Soumya Kanti Ganguly
2015-02-01T23:59:59.000Z
Contrary to the actual nonlinear Glauber model (NLGM), the linear Glauber model (LGM) is exactly solvable, although the detailed balance condition is not generally satisfied. This motivates us to address the issue of writing the transition rate ($w_j$) in a best possible linear form such that the mean squared error in satisfying the detailed balance condition is least. The advantage of this work is that, by studying the LGM analytically, we will be able to anticipate how the kinetic properties of an arbitrary Ising system depend on the temperature and the coupling constants. The analytical expressions for the optimal values of the parameters involved in the linear $w_j$ are obtained using a simple Moore-Penrose pseudoinverse matrix. This approach is quite general, in principle applicable to any system and can reproduce the exact results for one dimensional Ising system. In the continuum limit, we get a linear time-dependent Ginzburg-Landau (TDGL) equation from the Glauber's microscopic model of non-conservative dynamics. We analyze the critical and dynamic properties of the model, and show that most of the important results obtained in different studies can be reproduced by our new mathematical approach. We will also show in this paper that the effect of magnetic field can easily be studied within our approach; in particular, we show that the inverse of relaxation time changes quadratically with (weak) magnetic field and that the fluctuation-dissipation theorem is valid for our model.
A. L. Barabanov; R. Golub; S. K. Lamoreaux
2005-12-20T23:59:59.000Z
The search for particle electric dipole moments represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known E x v field with magnetic field gradients (often referred to as the geometric phase effect [9,10]). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic model for the correlation function which determines the behavior of the frequency shift [11], and show in detail how it depends on the operating conditions of the experiment. We also propose a method to directly measure ths correlation function under the exact conditions of a given experiment.
Kliman, G.B.; Brynsvold, G.V.; Jahns, T.M.
1989-08-22T23:59:59.000Z
A winding and method of winding for a submersible linear pump for pumping liquid sodium are disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet. 4 figs.
Kliman, Gerald B. (Schenectady, NY); Brynsvold, Glen V. (San Jose, CA); Jahns, Thomas M. (Schenectady, NY)
1989-01-01T23:59:59.000Z
A winding and method of winding for a submersible linear pump for pumping liquid sodium is disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet.
Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping
Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E.; Idzerda, Y.U.
2010-10-22T23:59:59.000Z
Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.
Evidence of half-metallic interface magnetism via local moment formation in Co based Heusler alloys
Telling, N. D.; Keatley, P.S.; van der Laan, G.; Hicken, R.J.; Arenholz, E.; Sakuraba, Y.; Oogane, M.; Ando, Y.; Miyazaki, T.
2008-08-18T23:59:59.000Z
In this work we use a combination of x-ray magnetic circular and linear dichroism (XMCD and XMLD) techniques to examine the formation of local moments in Heusler alloys of the composition Co{sub 2}MnX (where X=Si or Al). The existence of local moments in a half-metallic system is reliant upon the band gap in the minority-spin states. By utilizing the element-specific nature of x-ray techniques we are able to explore the origin of the minority-spin band gap in the partial density of states (PDOS), via the degree of localization of moments on Co and Mn atoms. We observe a crucial difference in the localization of the Co moment when comparing Co{sub 2}MnSi (CMS) and Co{sub 2}MnAl (CMA) films that is consistent with the predicted larger minority-spin gap in the Co PDOS for CMS. These results provide important evidence for the dominant role of the Co minority-spin states in realizing half-metallic ferromagnetism (HMF) in these Heusler alloys. They also demonstrate a direct method for measuring the degree of interfacial HMF in the raw materials without the need for fabricating spin-transport devices.
Thomas Wiegelmann; Bernd Inhester
2006-12-21T23:59:59.000Z
The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.
Voltage regulation in linear induction accelerators
Parsons, William M. (Santa Fe, NM)
1992-01-01T23:59:59.000Z
Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.
Voltage regulation in linear induction accelerators
Parsons, W.M.
1992-12-29T23:59:59.000Z
Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.
Electronic Non-Contacting Linear Position Measuring System
Post, Richard F. (Walnut Creek, CA)
2005-06-14T23:59:59.000Z
A non-contacting linear position location system employs a special transmission line to encode and transmit magnetic signals to a receiver on the object whose position is to be measured. The invention is useful as a non-contact linear locator of moving objects, e.g., to determine the location of a magnetic-levitation train for the operation of the linear-synchronous motor drive system.
Interaction of Ferromagnetic and Superconducting Permanent Magnets...
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permanent magnet track, was put into operation. A vehicle for 2 passengers, equipped with linear drive propulsion, a noncontact energy supply, a second braking system, and various...
T. T. Moh
2015-01-20T23:59:59.000Z
goal of this course is to enable you to recognize linear algebra problems ... descriptions of other people's solutions to problems that use linear algebra and to
STANFORD LINEAR ACCELERATOR CENTER RECORDS CONTROL SCHEDULE
Wechsler, Risa H.
to project justification, staffing, initiation, or execution; project management plans, records managementSTANFORD LINEAR ACCELERATOR CENTER PEP-II RECORDS CONTROL SCHEDULE SCOPE: This schedule covers records of the PEP-II project, regardless of format (paper, electronic, magnetic, photographic, etc
The Microscopic Linear Dynamics
Penny, Will
The Microscopic Brain Will Penny Linear Dynamics Exponentials Matrix Exponential Eigendecomposition Dynamical Modes Nodes State Space Saddles Oscillations Spirals Centres Offsets Retinal Circuit Nullclines Stability Spiking Neurons Fitzhugh-Nagumo Nonlinear Dynamics Linearization Nonlinear Oscillation Excitable
Zeghib, Abdelghani
Introduction Results Linear Dynamics Lorentz Dynamics Actions of discrete groups on stationary Piccione) Geodeycos Meeting, Lyon, 28-30 April 2010 Abdelghani Zeghib Dynamics on Lorentz manifolds #12;Introduction Results Linear Dynamics Lorentz Dynamics Motivations and questions Examples 1 Introduction
Generalized Linear Quadratic Control
Gattami, Ather Said
We consider the problem of stochastic finite- and infinite-horizon linear quadratic control under power constraints. The calculations of the optimal control law can be done off-line as in the classical linear quadratic ...
Villalba-Chávez, S., E-mail: selymv@gmail.com; Müller, C., E-mail: c.mueller@tp1.uni-duesseldorf.de
2013-12-15T23:59:59.000Z
Absorption and dispersion of probe photons in the field of a high-intensity circularly polarized laser wave are investigated. The optical theorem is applied for determining the absorption coefficients in terms of the imaginary part of the vacuum polarization tensor. Compact expressions for the vacuum refraction indices and the photon absorption coefficients are obtained in various asymptotic regimes of interest. The outcomes of this analysis reveal that, far from the region relatively close to the threshold of the two-photon reaction, the birefringence and dichroism of the vacuum are small and, in some cases, strongly suppressed. On the contrary, in a vicinity of the region in which the photo-production of a pair occurs, these optical properties are manifest with lasers of moderate intensities. We take advantage of such a property in the search of minicharged particles by considering high-precision polarimetric experiments. In addition, Raman-like electromagnetic waves resulting from the inelastic part of the vacuum polarization tensor are suggested as an alternative form for finding exclusion limits on these hypothetical charge carriers. The envisaged parameters of upcoming high-intensity laser facilities are used for establishing upper bounds on the minicharged particles. -- Highlights: •Via dichroism and birefringence of the vacuum by a strong laser wave, minicharged particles can be probed. •The discovery potential is the highest in a vicinity of the first pair production threshold. •As alternative observable, Raman scattered waves are put forward.
Introduction to Linear Relaxations
Introduction to Linear Relaxations by R. Baker Kearfott Department of Mathematics University relaxations; . discuss validation of linear relaxations. Intro. Linear Relaxations December, 2003 Taylor, . . . , m 2 , where # : R n # R and c i , g i : R n # R are guaranteed to be within one of the x # that has
New Magnetic confirguration in paramagnetic phase of HoCo2
Bonilla, C.M.; Calvo, I.; Herrero-Albillos, J.; Figueroa, A.I.; Castan-Guerrero, C.; Bertolome, J.; Rodriguez-Velamazan, J.A.; Schmitz, D.; Weschke, E.; Paudyal, Durga; Pecharsky, Vitalij; Gschneidner Jr, Karl; Bartolome, F.; Garcia, D.
2012-02-23T23:59:59.000Z
X-ray magnetic circular dichroism (XMCD) measurements on HoCo2 reveal the inversion of Co moment at temperatures higher than the critical temperature, Tc, showing that the net magnetization under a field of the Ho and Co sublattices remain antiparallel even above Tc. The Ho moment also changes its orientation to align antiparallel to the applied field at high temperature giving rise to a new magnetic configuration in the paramagnetic regime. Transverse susceptibility (TS) and small angle neutron scattering (SANS) measurements performed above Tc indicate the existence of sizable magnetic short-range correlated regions in HoCo2. First principles calculations based on spin polarized local-density approximation, LSDA+U havebeen performed to obtain insights on the origin of the short-range correlated volume.
Coronal heating in multiple magnetic threads
Tam, K V; Browning, P K; Cargill, P J
2015-01-01T23:59:59.000Z
Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims. By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results. The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this ...
Demmel, James; Holtz, Olga; Dumitriu, Ioana
2007-01-01T23:59:59.000Z
than other basic linear algebra subroutines. AcknowledgmentsApplied Numerical Linear Algebra. SIAM, 1997. [23] J.algorithms in numerical linear algebra. SIAM Review, 20:740–
Design and construction of a precision tubular linear motor and controller
Murphy, Bryan Craig
2004-09-30T23:59:59.000Z
A design for a novel tubular high-precision direct-drive brushless linear motor has been developed. The novelty of the design lies in the orientation of the magnets in the mover. In conventional linear motors the magnets of the armature...
Fault tolerant linear actuator
Tesar, Delbert
2004-09-14T23:59:59.000Z
In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.
Using Linearity Web Copyright 2007
Rodriguez, Carlos
Using Linearity Web Rev. 2.0 May 2007 Copyright © 2007 #12;Using Linearity Web i Contents Introduction to Linearity Web.............................................................................1 Features, Benefits, and Value of Linearity Web..............................................1 Before You
Radio frequency quadrupole resonator for linear accelerator
Moretti, Alfred (Downers Grove, IL)
1985-01-01T23:59:59.000Z
An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.
W. B. Vasantha Kandasamy; Florentin Smarandache
2008-07-18T23:59:59.000Z
In this book, the authors introduce the notion of Super linear algebra and super vector spaces using the definition of super matrices defined by Horst (1963). This book expects the readers to be well-versed in linear algebra. Many theorems on super linear algebra and its properties are proved. Some theorems are left as exercises for the reader. These new class of super linear algebras which can be thought of as a set of linear algebras, following a stipulated condition, will find applications in several fields using computers. The authors feel that such a paradigm shift is essential in this computerized world. Some other structures ought to replace linear algebras which are over a century old. Super linear algebras that use super matrices can store data not only in a block but in multiple blocks so it is certainly more powerful than the usual matrices. This book has 3 chapters. Chapter one introduces the notion of super vector spaces and enumerates a number of properties. Chapter two defines the notion of super linear algebra, super inner product spaces and super bilinear forms. Several interesting properties are derived. The main application of these new structures in Markov chains and Leontief economic models are also given in this chapter. The final chapter suggests 161 problems mainly to make the reader understand this new concept and apply them.
Investigation into electron cloud effects in the International Linear Collider positron damping ring
Furman, Miguel
Investigation into electron cloud effects in the International Linear Collider positron damping in the International Linear Collider positron damping ring. Updated optics, wiggler magnets, and vacuum chamber designs Linear Collider (ILC) [3]. Operation of the ILC depends critically on the reliable performance
Linear nanometric tunnel junction sensors with exchange pinned sensing layer
Leitao, D. C., E-mail: dleitao@inesc-mn.pt; Silva, A. V.; Cardoso, S. [INESC-MN and IN, Rua Alves Redol 9, 1000-029 Lisboa (Portugal); Instituto Superior Técnico (IST), Universidade de Lisboa, Av. Rovisco Pais, 1000-029 Lisboa (Portugal); Ferreira, R.; Paz, E.; Deepack, F. L. [INL, Av. Mestre Jose Veiga, 4715-31 Braga (Portugal); Freitas, P. P. [INESC-MN and IN, Rua Alves Redol 9, 1000-029 Lisboa (Portugal); INL, Av. Mestre Jose Veiga, 4715-31 Braga (Portugal)
2014-05-07T23:59:59.000Z
Highly sensitive nanosensors with high spatial resolution provide the necessary features for high accuracy imaging of isolated magnetic nanoparticles. In this work, we report the fabrication and characterization of MgO-barrier magnetic tunnel junction nanosensors, with two exchange-pinned electrodes. The perpendicular magnetization configuration for field sensing is set using a two-step annealing process, where the second annealing temperature was optimized to yield patterned sensors responses with improved linearity. The optimized circular nanosensors show sensitivities up to 0.1%/Oe, larger than previously reported for nanometric sensors and comparable to micrometric spin-valves. Our strategy avoids the use of external permanent biasing or demagnetizing fields (large for smaller structures) to achieve a linear response, enabling the control of the linear operation range using only the stack and thus providing a small footprint device.
Linearly parameterized bandits
Tsitsiklis, John N.
We consider bandit problems involving a large (possibly infinite) collection of arms, in which the expected reward of each arm is a linear function of an r-dimensional random vector Z ? ?(superscript r), where r ? 2. The ...
Linear Motor Powered Transportation
Thornton, Richard D.
This special issue on linear-motor powered transportation covers both supporting technologies and innovative transport systems in various parts of the World, as this technology moves from the lab to commercial operations. ...
The International Linear Collider
Jim Brau; Paul Grannis; Mike Harrison; Michael Peskin; Marc Ross; Harry Weerts
2013-04-09T23:59:59.000Z
We present a brief summary of the International Linear Collider as documented in the 2013 Technical Design Report. The Technical Design Report has detailed descriptions of the accelerator baseline design for a 500 GeV e+e- linear collider, the R&D program that has demonstrated its feasibility, the physics goals and expected sensitivities, and the description of the ILD and SiD detectors and their capabilities.
Not Available
1994-08-01T23:59:59.000Z
This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-{Tc} superconductor at low temperature.
Compensation of instabilities in magnetic Taylor-Couette flow Dima Shalybkov*
for the problem of a plasma confinement by the magnetic field. DOI: 10.1103/PhysRevE.76.027302 PACS number s : 47 The axisymmetric linear stability of the Taylor-Couette flow with an azimuthal magnetic field is considered magnetic field can be linearly stable. The flow stabilization takes place for both ideal and dissipative
Optimization Online - Linear-quadratic control problem with a linear ...
L Faybusovich
2003-12-19T23:59:59.000Z
Dec 19, 2003 ... Abstract: We describe a complete solution of the linear-quaratic control problem with the linear term in the objective function on a semiinfinite ...
6, 74277469, 2006 Linear ozone
Boyer, Edmond
ACPD 6, 74277469, 2006 Linear ozone photochemistry parametrizations A. J. Geer et al. Title Page Chemistry and Physics Discussions Evaluation of linear ozone photochemistry parametrizations Linear ozone photochemistry parametrizations A. J. Geer et al. Title Page Abstract Introduction
Linear Algebra: Ideas and Applications
Linear Algebra: Ideas and Applications. [photo]. Welcome to the web page for Linear Algebra: Idaes and Applications by Richard Penney. This web site is ...
Magnetic phases and structural properties in Co/Ru superlattices
Alayo, W.; Tafur, Miguel; Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro 22290-180 (Brazil); Pelegrini, F. [Instituto de Fisica, Universidade Federal de Goias, Goiania 74001-970 (Brazil); Nascimento, V. P. [Centro Universitario Norte do Espirito Santo, Universidade Federal do Espirito Santo, Sao Mateus 29933-415 (Brazil)
2009-05-01T23:59:59.000Z
We report studies by x-ray diffraction, ferromagnetic resonance (FMR), and x-ray magnetic circular dichroism (XMCD) in Co/Ru superlattices grown by magnetron sputtering. We studied the [Co(50 A)/Ru(t{sub Ru})]{sub 20} samples, which were deposited at room temperature on Si substrates with the Ru thicknesses, t{sub Ru}, varying between 9 and 33 A. The main and secondary uniform absorption modes, observed in the FMR spectra, are associated with the Co/Ru interfaces and the bulk Co regions, respectively. The main mode becomes more intense than the secondary one for increasing t{sub Ru}. This is attributed to the roughness and/or atomic interdiffusion, which leads, with increasing t{sub Ru}, to an increasing volume of Co/Ru interfacial regions and a decreasing volume of pure Co regions. The XMCD measurements provide Co spin magnetic moments lower than the bulk Co value, confirming the presence of a Co magnetic region with a lower local effective magnetization attributed to the Co/Ru interfaces.
Laser Transmission Studies with Magnetic Nanofluids
Pai, Chintamani; Momin, Nooris; Srinivasan, Radha; Nagarajan, R
2015-01-01T23:59:59.000Z
Transmission of He-Ne (632 nm, 10 mW) Gaussian laser beam through Hexane and Water based magnetic nanofluids containing Fe3O4 nanoparticles show strong non-linear and magneto-optical effects. Application of external magnetic field (up to 1.7 Wb/m2) perpendicular to the incident laser beam produces a change in forward scattered pattern of the incident laser beam. Dependence of forward scattered patterns in presence of external magnetic field has been studied. Image processing has been carried out to understand spatial distribution of the forward scattered patterns and temporal evolution of patterns involving particle image velocimetry technique. Change in non-linear refractive index is estimated for samples showing self-diffraction arising from higher order non-linear optical effect. Observed effects are useful for understanding light scattering from magnetic nanofluids and developing optofluidic devices and sensors.
Spectral learning of linear dynamics from generalised-linear observations
a non-linear and non-Gaussian observation process. We use this approach to obtain estimates to the generalised-linear regression model [8]), where the expected value of an observation is given by a monotonicSpectral learning of linear dynamics from generalised-linear observations with application
QPL 2005 Preliminary Version De-linearizing linearity: projective quantum
Selinger, Peter
QPL 2005 Preliminary Version De-linearizing linearity: projective quantum axiomatics from strong the linear structure of Hilbert spaces into several constituents which play different roles in quantum)famous Birkhoff- von Neumann paper [7]. The bulk of the linear structure required to reason about quantum
W. B. Vasantha Kandasamy; Florentin Smarandache
2010-12-08T23:59:59.000Z
In this book we use only special types of intervals and introduce the notion of different types of interval linear algebras and interval vector spaces using the intervals of the form [0, a] where the intervals are from Zn or Z+ \\cup {0} or Q+ \\cup {0} or R+ \\cup {0}. A systematic development is made starting from set interval vector spaces to group interval vector spaces. Vector spaces are taken as interval polynomials or interval matrices or just intervals over suitable sets or semigroups or groups. Main feature of this book is the authors have given over 350 examples. This book has six chapters. Chapter one is introductory in nature. Chapter two introduces the notion of set interval linear algebras of type one and two. Set fuzzy interval linear algebras and their algebras and their properties are discussed in chapter three. Chapter four introduces several types of interval linear bialgebras and bivector spaces and studies them. The possible applications are given in chapter five. Chapter six suggests nearly 110 problems of all levels.
Linear Programming Environmental
Nagurney, Anna
Linear Program to control air pollution was developed in 1968 by Teller, which minimized cost Fall 2006 #12;Topics · Introduction · Background · Air · Land · Water #12;Introduction · "The United States spends more than 2% of its gross domestic product on pollution control, and this is more than any
Automatic Linear Orders (Revised Version)
Stephan, Frank
CDMTCS Research Report Series Automatic Linear Orders and Trees (Revised Version) Bakhadyr; Automatic Linear Orders and Trees Bakhadyr Khoussainov, Sasha Rubin and Frank Stephan November 13, 2003 emphasis is on trees and linear orders. We study the relationship between automatic linear orders and trees
Becker, Jörg D
2015-01-01T23:59:59.000Z
In many European countries the growth of the real GDP per capita has been linear since 1950. An explanation for this linearity is still missing. We propose that in artificial intelligence we may find models for a linear growth of performance. We also discuss possible consequences of the fact that in systems with linear growth the percentage growth goes to zero.
Development of compact linear accelerator in KBSI
Yoon, Jang-Hee; Lee, Byoung-Seob; Choi, Seyong; Park, Jin Yong; Ok, Jung-Woo; Won, Mi-Sook [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)
2012-02-15T23:59:59.000Z
The compact linear accelerator using a 28 GHz ECRIS is under construction in KBSI, South Korea. The main capability of this facility is the production of fast neurons for the neutron radiography. The designing of a superconducting magnet, microwave transmission system, beam extraction, and plasma chamber of ECRIS were finished. The nominal axial design fields of the magnets are 3.6 T at injection and 2.2 T at extraction; the nominal radial design field strength at the plasma chamber wall is 2.1 T. We already installed 10 kW, 28 GHz gyrotron, and tested a microwave power from gyrotron using a dummy load. The current status will be discussed in this paper.
Modified Magnetic Ground State in Nimn (2) O (4) Thin Films
Nelson-Cheeseman, B.B.; Chopdekar, R.V.; Iwata, J.M.; Toney, M.F.; Arenholz, E.; Suzuki, Y.; /SLAC
2012-08-23T23:59:59.000Z
The authors demonstrate the stabilization of a magnetic ground state in epitaxial NiMn{sub 2}O{sub 4} (NMO) thin films not observed in their bulk counterpart. Bulk NMO exhibits a magnetic transition from a paramagnetic phase to a collinear ferrimagnetic moment configuration below 110 K and to a canted moment configuration below 70 K. By contrast, as-grown NMO films exhibit a single magnetic transition at 60 K and annealed films exhibit the magnetic behavior found in bulk. Cation inversion and epitaxial strain are ruled out as possible causes for the new magnetic ground state in the as-grown films. However, a decrease in the octahedral Mn{sup 4+}:Mn{sup 3+} concentration is observed and likely disrupts the double exchange that produces the magnetic state at intermediate temperatures. X-ray magnetic circular dichroism and bulk magnetometry indicate a canted ferrimagnetic state in all samples at low T. Together these results suggest that the collinear ferrimagnetic state observed in bulk NMO at intermediate temperatures is suppressed in the as grown NMO thin films due to a decrease in octahedral Mn{sup 4+}, while the canted moment ferrimagnetic ordering is preserved below 60 K.
Modified magnetic ground state in NiMn2O4 thin films
Nelson-Cheeseman, B. B.; Chopdekar, R. V.; Toney, M. F.; Arenholz, E.; Suzuki, Y.; Iwata, J.M.
2010-08-03T23:59:59.000Z
We demonstrate the stabilization of a magnetic ground state in epitaxial NiMn2O4 (NMO) thin films not observed in their bulk counterpart. Bulk NMO exhibits a magnetic transition from a paramagnetic phase to a collinear ferrimagnetic moment configuration below 110 K and to a canted moment configuration below 70 K. By contrast, as-grown NMO films exhibit a single magnetic transition at 60 K and annealed films exhibit the magnetic behavior found in bulk. Cation inversion and epitaxial strain are ruled out as possible causes for the new magnetic ground state in the as-grown films. However, a decrease in the octahedral Mn{sup 4+}:Mn{sup 3+} concentration is observed and likely disrupts the double exchange that produces the magnetic state at intermediate temperatures. X-ray magnetic circular dichroism and bulk magnetometry indicate a canted ferrimagnetic state in all samples at low temperature. Together these results suggest that the collinear ferrimagnetic state observed in bulk NMO at intermediate temperatures is suppressed in the as grown NMO thin films due to a decrease in octahedral Mn{sup 4+} while the canted moment ferrimagnetic ordering is preserved below 60 K.
Ito, Keita; Sanai, Tatsunori; Yasutomi, Yoko; Toko, Kaoru; Honda, Syuta; Suemasu, Takashi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)] [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Zhu, Siyuan; Kimura, Akio [Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Ueda, Shigenori [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science (NIMS), 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan)] [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science (NIMS), 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Takeda, Yukiharu; Saitoh, Yuji [Condensed Matter Science Division, Japan Atomic Energy Agency (JAEA), 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan)] [Condensed Matter Science Division, Japan Atomic Energy Agency (JAEA), 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Imai, Yoji [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan) [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan)
2013-12-02T23:59:59.000Z
We evaluated electronic structures and magnetic moments in Co{sub 3}FeN epitaxial films on SrTiO{sub 3}(001). The experimentally obtained hard x-ray photoemission spectra of the Co{sub 3}FeN film have a good agreement with those calculated. Site averaged spin magnetic moments deduced by x-ray magnetic circular dichroism were 1.52 ?{sub B} per Co atom and 2.08 ?{sub B} per Fe atom at 100 K. They are close to those of Co{sub 4}N and Fe{sub 4}N, respectively, implying that the Co and Fe atoms randomly occupy the corner and face-centered sites in the Co{sub 3}FeN unit cell.
Position sensor for linear synchronous motors employing halbach arrays
Post, Richard Freeman
2014-12-23T23:59:59.000Z
A position sensor suitable for use in linear synchronous motor (LSM) drive systems employing Halbach arrays to create their magnetic fields is described. The system has several advantages over previously employed ones, especially in its simplicity and its freedom from being affected by weather conditions, accumulated dirt, or electrical interference from the LSM system itself.
Design and sizing of electromagnetic linear actuators for valve applications
Paris-Sud XI, Université de
Page 1/9 Design and sizing of electromagnetic linear actuators for valve applications J.C Vannier1. These structures have been studied in order to drive the valves of a car motor. According to general specifications magnet, valves. 1. Introduction, general specifications The valves which can be found in thermal engines
Crozier, Richard Carson
2014-06-30T23:59:59.000Z
Combined electrical and structural models of five types of permanent magnet linear electrical machines suitable for direct-drive power take-off on wave energy applications are presented. Electromagnetic models were ...
Banks, R.M.
1986-01-14T23:59:59.000Z
This patent describes a linear output nitinol engine consisting of a number of integrated communicating parts. The engine has an external support framework which is described in detail. The patent further describes a wire transport mechanism, a pair of linkage levers with a loom secured to them, a number of nitinol wires strung between the looms, and a power takeoff block secured to the linkage levers. A pulley positioned in a flip-flop supporting bracket and a power takeoff modality including a tension member connected to a power output cable in order to provide linear power output transmission is described. A method for biasing the timing and the mechanism for timing the synchronization of the throw over arms and the flip-flop of the pulley are also described.
Buttram, M.T.; Ginn, J.W.
1988-06-21T23:59:59.000Z
A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.
Combustion powered linear actuator
Fischer, Gary J. (Albuquerque, NM)
2007-09-04T23:59:59.000Z
The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.
Kerns, J.A.; Stone, R.R.; Fabyan, J.
1985-02-12T23:59:59.000Z
A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.
The International Linear Collider
Barish, Barry
2013-01-01T23:59:59.000Z
In this article, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200-500 GeV linear electron-positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly twenty years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages beginning as a Hig...
Jacques Carolan; Chris Harrold; Chris Sparrow; Enrique Martín-López; Nicholas J. Russell; Joshua W. Silverstone; Peter J. Shadbolt; Nobuyuki Matsuda; Manabu Oguma; Mikitaka Itoh; Graham D. Marshall; Mark G. Thompson; Jonathan C. F. Matthews; Toshikazu Hashimoto; Jeremy L. O'Brien; Anthony Laing
2015-05-05T23:59:59.000Z
Linear optics underpins tests of fundamental quantum mechanics and computer science, as well as quantum technologies. Here we experimentally demonstrate the longstanding goal of a single reprogrammable optical circuit that is sufficient to implement all possible linear optical protocols up to the size of that circuit. Our six-mode universal system consists of a cascade of 15 Mach-Zehnder interferometers with 30 thermo-optic phase shifters integrated into a single photonic chip that is electrically and optically interfaced for arbitrary setting of all phase shifters, input of up to six photons and their measurement with a 12 single-photon detector system. We programmed this system to implement heralded quantum logic and entangling gates, boson sampling with verification tests, and six-dimensional complex Hadamards. We implemented 100 Haar random unitaries with average fidelity 0.999 $\\pm$ 0.001. Our system is capable of switching between these and any other linear optical protocol in seconds. These results point the way to applications across fundamental science and quantum technologies.
Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)
2010-11-16T23:59:59.000Z
A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.
Linear optimization Linear programming using the Simplex method
McCready, Mark J.
Linear optimization Linear programming using the Simplex method Maximize M = 40 x1 + 60 x2 subject, that increasing x2 is the way to get the biggest impact. The idea of the simplex method is to move only
Algorithms for Solving Linear Congruences and Systems of Linear Congruences
Florentin Smarandache
2007-02-16T23:59:59.000Z
In this article we determine several theorems and methods for solving linear congruences and systems of linear congruences, and we find the number of distinct solutions. Many examples of solving congruences are given.
Magnets & Magnet Condensed Matter Science
McQuade, D. Tyler
18 No. 1 CONDENSED MATTER SCIENCE Technique development, graphene, magnetism & magnetic materials Pressure 9 Metal to Insulator Transition on the N=0 Landau Level in Graphene 10 Evidence for Fractional Quantum Hall States in Suspended Bilayer and Trilayer Graphene 11 Fractional Quantum Hall Effect
Structure based chemical shift prediction using Random Forests non-linear regression
Langmead, Christopher James
Structure based chemical shift prediction using Random Forests non-linear regression K. Arun-ordinates will permit close study of this relationship. This paper presents a novel non-linear regression based ap, regression, Random Forests #12;Abstract Protein nuclear magnetic resonance (NMR) chemical shifts are among
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON-LOCAL
RodrÃguez, Rodolfo
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON@ing-mat.udec.cl This paper deals with an axisymmetric transient eddy current problem in conductive nonlinear magnetic media of the proposed scheme. Keywords: transient eddy current problem; electromagnetic losses; nonlinear magnetic
Park, Joung Won
2010-10-12T23:59:59.000Z
, and Temperature (PVT) variations and increase high power input capability. After analyzing and designing a resistive feedback LNA, novel linearization methods were applied. A highly linear broadband LNA is designed and simulated in 65nm CMOS technology. Simulation...
Park, Joung Won
2010-10-12T23:59:59.000Z
In this work, a highly linear broadband Low Noise Amplifier (LNA) is presented. The linearity issue in broadband Radio Frequency (RF) front-end is introduced, followed by an analysis of the specifications and requirements of a broadband LNA through...
The International Linear Collider
Marco Battaglia
2007-05-28T23:59:59.000Z
The International Linear Collider (ILC) is the next large scale project in accelerator particle physics. Colliding electrons with positrons at energies from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy needed to complement the LHC data and extend the sensitivity to new phenomena at the high energy frontier and answer some of the fundamental questions in particle physics and in its relation to Cosmology. This paper reviews some highlights of the ILC physics program and some of the major challenges for the accelerator and detector design.
Optimization of a dual acting, magnetically driven, linear actuator
Willerton, Justin Ryan
2002-01-01T23:59:59.000Z
will be found. Once complete, a different approach in meeting the design objectives of a stroke length of at least 10 mils, a low maximum coil temperature and a low actuator weight, will be taken. Instead of optimizing the geometry, the rubber pads...
High force density linear permanent magnet motors : "electromagnetic muscle actuators"
Ruddy, Bryan P. (Bryan Paul), 1983-
2012-01-01T23:59:59.000Z
Actuator performance represents a key constraint on the capability of many engineered devices. Performance of these devices is often exceeded by their muscle-powered natural counterparts, inspiring the development of new, ...
Optimization of a dual acting, magnetically driven, linear actuator
Willerton, Justin Ryan
2002-01-01T23:59:59.000Z
will be found. Once complete, a different approach in meeting the design objectives of a stroke length of at least 10 mils, a low maximum coil temperature and a low actuator weight, will be taken. Instead of optimizing the geometry, the rubber pads...
Linear Solvers 1.Introduction [1
McCalley, James D.
linear algebra packages including LAPACK, ScaLAPACK and PETSc, are built on top of BLAS. Most of standard, portable solver libraries available, including: BLAS (Basic linear algebra subprograms): Many (Automatically Tuned Linear Algebra Software package) is a version of BLAS that, upon installation, tests
Wave functions of linear systems
Tomasz Sowinski
2007-06-05T23:59:59.000Z
Complete analysis of quantum wave functions of linear systems in an arbitrary number of dimensions is given. It is shown how one can construct a complete set of stationary quantum states of an arbitrary linear system from purely classical arguments. This construction is possible because for linear systems classical dynamics carries the whole information about quantum dynamics.
Simple Linear Regression Basic Ideas
Simple Linear Regression Basic Ideas Some Examples Least Squares Statistical View of Least Squares of Least Squares #12;Simple Linear Regression Basic Ideas Some Examples Least Squares Basic Ideas Suppose #12;Simple Linear Regression Basic Ideas Some Examples Least Squares Basic Ideas Suppose we have two
Special set linear algebra and special set fuzzy linear algebra
W. B. Vasantha Kandasamy; Florentin Smarandache; K. Ilanthenral
2009-12-30T23:59:59.000Z
The authors in this book introduce the notion of special set linear algebra and special set fuzzy Linear algebra, which is an extension of the notion set linear algebra and set fuzzy linear algebra. These concepts are best suited in the application of multi expert models and cryptology. This book has five chapters. In chapter one the basic concepts about set linear algebra is given in order to make this book a self contained one. The notion of special set linear algebra and their fuzzy analogue is introduced in chapter two. In chapter three the notion of special set semigroup linear algebra is introduced. The concept of special set n-vector spaces, n greater than or equal to three is defined and their fuzzy analogue is their fuzzy analogue is given in chapter four. The probable applications are also mentioned. The final chapter suggests 66 problems.
Fryberger, D.
1984-12-01T23:59:59.000Z
In this talk on magnetic monopoles, first the author briefly reviews some historical background; then, the author describes what several different types of monopoles might look like; and finally the author discusses the experimental situation. 81 references.
Laminated grid and web magnetic cores
Sefko, John (Monroeville, PA); Pavlik, Norman M. (Plum Borough, PA)
1984-01-01T23:59:59.000Z
A laminated magnetic core characterized by an electromagnetic core having core legs which comprise elongated apertures and edge notches disposed transversely to the longitudinal axis of the legs, such as high reluctance cores with linear magnetization characteristics for high voltage shunt reactors. In one embodiment the apertures include compact bodies of microlaminations for more flexibility and control in adjusting permeability and/or core reluctance.
The International Linear Collider
Karsten Buesser
2013-06-13T23:59:59.000Z
The International Linear Collider (ILC) is a proposed electron-positron collider for the centre-of-mass energy range of 200 to 500 GeV and with upgrade options towards 1 TeV. The ILC would be the ideal tool to explore with high precision the properties of the new Higgs-like particle that has recently been discovered at the LHC with a mass of around 125 GeV. The ILC accelerator design is based on the mature superconducting technology that has been developed in the TESLA collaboration and that is currently being used for the European XFEL. The exploitation of the huge physics potential of the ILC is a challenge for the design of the ILC detectors.
Positrons for linear colliders
Ecklund, S.
1987-11-01T23:59:59.000Z
The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)
Adjustable permanent quadrupoles for the next linear collider
James T. Volk et al.
2001-06-22T23:59:59.000Z
The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 138 Tesla, with a maximum gradient of 141 Tesla per meter, an adjustment range of +0 to {minus}20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20% adjustment. In an effort to reduce costs and increase reliability, several designs using hybrid permanent magnets have been developed. Four different prototypes have been built. All magnets have iron poles and use Samarium Cobalt to provide the magnetic fields. Two use rotating permanent magnetic material to vary the gradient, one uses a sliding shunt to vary the gradient and the fourth uses counter rotating magnets. Preliminary data on gradient strength, temperature stability, and magnetic center position stability are presented. These data are compared to an equivalent electromagnetic prototype.
Linear Algebraic Method for Non-Linear Map Analysis
Yu,L.; Nash, B.
2009-05-04T23:59:59.000Z
We present a newly developed method to analyze some non-linear dynamics problems such as the Henon map using a matrix analysis method from linear algebra. Choosing the Henon map as an example, we analyze the spectral structure, the tune-amplitude dependence, the variation of tune and amplitude during the particle motion, etc., using the method of Jordan decomposition which is widely used in conventional linear algebra.
Spin noise spectroscopy beyond thermal equilibrium and linear response
P. Glasenapp; Luyi Yang; D. Roy; D. G. Rickel; A. Greilich; M. Bayer; N. A. Sinitsyn; S. A. Crooker
2014-07-10T23:59:59.000Z
Per the fluctuation-dissipation theorem, the information obtained from spin fluctuation studies in thermal equilibrium is necessarily constrained by the system's linear response functions. However, by including weak radiofrequency magnetic fields, we demonstrate that intrinsic and random spin fluctuations even in strictly unpolarized ensembles \\emph{can} reveal underlying patterns of correlation and coupling beyond linear response, and can be used to study non-equilibrium and even multiphoton coherent spin phenomena. We demonstrate this capability in a classical vapor of $^{41}$K alkali atoms, where spin fluctuations alone directly reveal Rabi splittings, the formation of Mollow triplets and Autler-Townes doublets, ac Zeeman shifts, and even nonlinear multiphoton coherences.
A polynomial projection algorithm for linear programming
2013-05-03T23:59:59.000Z
We propose a polynomial algorithm for linear programming. The algorithm represents a linear optimization or decision problem in the form of a system of linear ...
International linear collider reference design report
Aarons, G.
2008-01-01T23:59:59.000Z
A. Loew, et al. , “International Linear Collider Technologyfor the International Linear Collider”, in preparation [37]for the International Linear Collider,” in PAC05,http://
Linear and nonlinear wave propagation in weakly relativistic quantum plasmas
Stefan, Martin; Brodin, Gert [Department of Physics, Umea University, SE-901 87 Umea (Sweden)
2013-01-15T23:59:59.000Z
We consider a recently derived kinetic model for weakly relativistic quantum plasmas. We find that that the effects of spin-orbit interaction and Thomas precession may alter the linear dispersion relation for a magnetized plasma in case of high plasma densities and/or strong magnetic fields. Furthermore, the ponderomotive force induced by an electromagnetic pulse is studied for an unmagnetized plasma. It turns out that for this case the spin-orbit interaction always gives a significant contribution to the quantum part of the ponderomotive force.
Royet, J.M.
2011-01-01T23:59:59.000Z
J. Royet, "Magnet Cable Manufacturing", oral presentation atDivision Magnet Cable Manufacturing J. Royet October 1990J I Magnet Cable Manufacturing* John Royet Accelerator &
6, 66276694, 2006 linearized ozone
Boyer, Edmond
ACPD 6, 66276694, 2006 CHEM2D-OPP linearized ozone photochemistry J. P. McCormack et al. Title Chemistry and Physics Discussions CHEM2D-OPP: A new linearized gas-phase ozone photochemistry.mccormack@nrl.navy.mil) 6627 #12;ACPD 6, 66276694, 2006 CHEM2D-OPP linearized ozone photochemistry J. P. McCormack et al
Linear Programming and Kantorovich Spaces
S. Kutateladze
2009-05-08T23:59:59.000Z
This is a brief overview of the life of Leonid Kantorovich (1912--1986) and his contribution to the fields of linear programming and ordered vector spaces.
Linear Algebra 1: Computing canonical forms in exact linear
Pernet, Clément
Linear Algebra 1: Computing canonical forms in exact linear algebra Clément PERNET, LIG, where U is invertible Reduced echelon form: E = 1 0 0 1 0 1 Gauss-Jordan elimination #12 a field: B = U-1 AU Frobenius normal form (or canonical rational form): F = CP0 CP1 ... CPk
Identifying Redundant Linear Constraints in Systems of Linear ...
2006-06-22T23:59:59.000Z
Jun 22, 2006 ... redundant linear constraints from the system (2.1) and (2.2). ... It is informative to note that in the above theorem, the optimal ..... S. Boyd and L. El Ghaoui, “Linear Matrix Inequalities in System and Control Theory”, SIAM, vol.
Another Detector for the International Linear Collider
Nural Akchurin; Sehwook Lee; Richard Wigmans; Hanna Arnold; Aaron Bazal; Robert Basili; John Hauptman; Tim Overton; Andrew Priest; Bingzhe Zhao; Alexander Mikhailichenko; Michele Cascella; Franco Grancagnolo; Giovanni Tassielli; Franco Bedeschi; Fabrizio Scuri; Sung Keun Park; Fedor Ignatov; Gabriella Gaudio; Michele Livan
2013-07-25T23:59:59.000Z
We describe another detectora designed for the International Linear Collider based on several tested instrumentation innovations in order to achieve the necessary experi- mental goal of a detecter that is 2-to-10 times better than the already excellent SLC and LEP detectors, in particular, (1) dual-readout calorimeter system based on the RD52/DREAM measurements at CERN, (2) a cluster-counting drift chamber based on the successful kloe chamber at Frascati, and (3) a second solenoid to return the magnetic flux without iron. A high-performance pixel vertex chamber is presently undefined. We discuss particle identification, momentum and energy resolutions, and the machine-detector interface that together offer the possibility of a very high-performance detector for $e^+e^-$physics up to $\\sqrt{s} = 1$ TeV.
Radio-frequency quadrupole resonator for linear accelerator
Moretti, A.
1982-10-19T23:59:59.000Z
An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.
Baryon magnetic moments in the background field method
Lee, F X; Zhou, L; Wilcox, W
2005-01-01T23:59:59.000Z
We present a calculation of the magnetic moments for the baryon octet and decuplet using the background-field method and standard Wilson gauge and fermion actions in the quenched approximation of lattice QCD. Progressively smaller static magnetic fields are introduced on a $24^4$ lattice at beta=6.0 and the pion mass is probed down to about 500 MeV. Magnetic moments are extracted from the linear response of the masses to the background field.
Baryon magnetic moments in the external field method
Lee, F X; Zhou, L; Wilcox, W
2005-01-01T23:59:59.000Z
We present a calculation of the magnetic moments of the baryon octet and decuplet using the external field method and standard Wilson gauge and fermion actions in the quenched approximation. Progressively smaller static magnetic fields are introduced on a $24^4$ latticeat beta=6.0 and the pion mass is probed down to about 500 MeV. Magnetic moments are extracted from the linear response of the masses to the external field.
Electric-Magnetic Duality Invariant Lagrangians
Machiko Hatsuda; Kiyoshi Kamimura; Sayaka Sekiya
1999-08-24T23:59:59.000Z
We find general non-linear lagrangians of a U(1) field invariant under electric-magnetic duality. They are characterized by an arbitrary function and go to the Maxwell theory in the weak field limit. We give some explicit examples which are generalizations of the Born-Infeld theory.
Astrophysical Gyrokinetics: Basic Equations and Linear Theory
Gregory G. Howes; Steven C. Cowley; William Dorland; Gregory W. Hammett; Eliot Quataert; Alexander A. Schekochihin
2006-05-04T23:59:59.000Z
Magnetohydrodynamic (MHD) turbulence is encountered in a wide variety of astrophysical plasmas, including accretion disks, the solar wind, and the interstellar and intracluster medium. On small scales, this turbulence is often expected to consist of highly anisotropic fluctuations with frequencies small compared to the ion cyclotron frequency. For a number of applications, the small scales are also collisionless, so a kinetic treatment of the turbulence is necessary. We show that this anisotropic turbulence is well described by a low frequency expansion of the kinetic theory called gyrokinetics. This paper is the first in a series to examine turbulent astrophysical plasmas in the gyrokinetic limit. We derive and explain the nonlinear gyrokinetic equations and explore the linear properties of gyrokinetics as a prelude to nonlinear simulations. The linear dispersion relation for gyrokinetics is obtained and its solutions are compared to those of hot-plasma kinetic theory. These results are used to validate the performance of the gyrokinetic simulation code {\\tt GS2} in the parameter regimes relevant for astrophysical plasmas. New results on global energy conservation in gyrokinetics are also derived. We briefly outline several of the problems to be addressed by future nonlinear simulations, including particle heating by turbulence in hot accretion flows and in the solar wind, the magnetic and electric field power spectra in the solar wind, and the origin of small-scale density fluctuations in the interstellar medium.
Linear diffusion into a Faraday cage.
Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.
2011-11-01T23:59:59.000Z
Linear lightning diffusion into a Faraday cage is studied. An early-time integral valid for large ratios of enclosure size to enclosure thickness and small relative permeability ({mu}/{mu}{sub 0} {le} 10) is used for this study. Existing solutions for nearby lightning impulse responses of electrically thick-wall enclosures are refined and extended to calculate the nearby lightning magnetic field (H) and time-derivative magnetic field (HDOT) inside enclosures of varying thickness caused by a decaying exponential excitation. For a direct strike scenario, the early-time integral for a worst-case line source outside the enclosure caused by an impulse is simplified and numerically integrated to give the interior H and HDOT at the location closest to the source as well as a function of distance from the source. H and HDOT enclosure response functions for decaying exponentials are considered for an enclosure wall of any thickness. Simple formulas are derived to provide a description of enclosure interior H and HDOT as well. Direct strike voltage and current bounds for a single-turn optimally-coupled loop for all three waveforms are also given.
Extreme hydrogen plasma densities achieved in a linear plasma generator
Rooij, G. J. van; Veremiyenko, V. P.; Goedheer, W. J.; de Groot, B.; Kleyn, A. W.; Smeets, P. H. M.; Versloot, T. W.; Whyte, D. G.; Engeln, R.; Schram, D. C.; Cardozo, N. J. Lopes [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein, Uthrecht 3430BE (Netherlands); Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein, Uthrecht 3430BE (NL) and Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)
2007-03-19T23:59:59.000Z
A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5x10{sup 20} m{sup -3} electron density, {approx}2 eV electron and ion temperatures, and 3.5 km/s axial plasma velocity. This gives a 2.6x10{sup 24} H{sup +} m{sup -2} s{sup -1} peak ion flux density, which is unprecedented in linear plasma generators. The high efficiency of the source is obtained by the combined action of the magnetic field and an optimized nozzle geometry. This is interpreted as a cross-field return current that leads to power dissipation in the beam just outside the source.
Masaaki Yamada, Russell Kulsrud and Hantao Ji
2009-09-17T23:59:59.000Z
We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.
Patterned Magnetic Nanostructures and Quantized Magnetic Disks
-increasing demands in data storage and to new applications of magnetic devices in the field of sensors. NewPatterned Magnetic Nanostructures and Quantized Magnetic Disks STEPHEN Y. CHOU Invited Paper, opens up new opportunities for engineering innovative magnetic materials and devices, developing ultra
An optimized magnet for magnetic refrigeration
Bjørk, R; Smith, A; Christensen, D V; Pryds, N
2014-01-01T23:59:59.000Z
A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halbach cylinder magnet design and dimensioning and segmenting this design in an optimum way followed by the construction of the actual magnet. The final design generates a peak value of 1.24 T, an average flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an average low flux density of 0.08 T also in a 2 L volume. The working point of all the permanent magnet blocks in the design is very close to the maximum energy density. The final design is characterized in terms of a performance parameter, and it is shown that it is one of the best performing magnet designs published for magnetic refrigeration.
Magnetic positioner having a single moving part
Trumper, David L. (Plaistow, NH); Kim, Won-Jong (Cambridge, MA)
1999-01-01T23:59:59.000Z
A magnetic positioner is provided which is capable of providing long travel in two dimension and short travel in the remaining four dimensions. The positioner has a movable stage and a stator oriented adjacent and substantially parallel to this stage. At least three sets of first magnetic elements, which for preferred embodiments are winding sets capable of generating forces in two directions, are on the portion of the stator adjacent to the stage at any given time, and at least two second magnetic elements, which are magnet arrays for the preferred embodiment, are on the stage adjacent to the stator. At least one of the second magnetic elements overlaps multiple first magnetic elements for all positions of the stage relative to the stator, with one magnet overlapping multiple windings for one preferred embodiment of the invention and two magnets on the stage overlapping multiple windings on the stator for a second embodiment. The windings form a linear motor providing forces in both a corresponding long travel dimension and in a dimension perpendicular to both long travel dimensions.
Acoustic emission linear pulse holography
Collins, H.D.; Busse, L.J.; Lemon, D.K.
1983-10-25T23:59:59.000Z
This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.
Magnetic Gas Sensing Using a Dilute Magnetic Semiconductor. ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Gas Sensing Using a Dilute Magnetic Semiconductor. Magnetic Gas Sensing Using a Dilute Magnetic Semiconductor. Abstract: The authors report on a magnetic gas sensing methodology to...
Linear Consistency Testing Yonatan Aumann
Sudan, Madhu
of Blum, Luby and Rubinfeld [?] to check the linear-consistency of three functions f1, f2, f3 mapping and check if f1(x) + f2(y) = f3(x + y). We analyze this test for two cases: (1) G and H are arbitrary the consistency of multiple functions. Given a triple of functions f1, f2, f3 : G H, we say that they are "linear
A linear induction motor conveyer
Solinsky, Kenneth Sheldon
1973-01-01T23:59:59.000Z
A LINEAR INCUCTION MOTOR CONVEYER A Thesis Kenneth Sheldon. Solinsky Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement for the degree of MASTER 07 SCIENCE May 1973 Major Subject: Industrial.... Howie, USAMC-ITC-P/P, Red River Army Depot, Texarkana, Texas 75501. Approved owxe, xe , ro uc o uction Engineering For the Commander ne , grec or, I A LINEAR INDUCTION MOTOR CONVEYER A Thesis by Kenneth Sheldon Solinsky App ved as to style...
Including stereoscopic information in the reconstruction of coronal magnetic fields
T. Wiegelmann; T. Neukirch
2008-01-23T23:59:59.000Z
We present a method to include stereoscopic information about the three dimensional structure of flux tubes into the reconstruction of the coronal magnetic field. Due to the low plasma beta in the corona we can assume a force free magnetic field, with the current density parallel to the magnetic field lines. Here we use linear force free fields for simplicity. The method uses the line of sight magnetic field on the photosphere as observational input. The value of $\\alpha$ is determined iteratively by comparing the reconstructed magnetic field with the observed structures. The final configuration is the optimal linear force solution constrained by both the photospheric magnetogram and the observed plasma structures. As an example we apply our method to SOHO MDI/EIT data of an active region. In the future it is planned to apply the method to analyse data from the SECCHI instrument aboard the STEREO mission.
Superconducting Magnet Division
Gupta, Ramesh
Superconducting Magnet Division Permanent Magnet Designs with Large Variations in Field Strength the residual field of the magnetized bricks by concentrating flux lines at the iron pole. Low Field Design Medium Field Design Superconducting Magnet Division Dipole and Quadrupole Magnets for RHIC e
Satti, John A. (Naperville, IL)
1980-01-01T23:59:59.000Z
A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.
Algorithms for Symmetric Linear and Integer Programs
Bödi, Richard; Joswig, Michael
2010-01-01T23:59:59.000Z
This paper deals with exploiting symmetry for solving linear and integer programming problems. Basic properties of linear representations of finite groups can be used to reduce symmetric linear programming to solving linear programs of lower dimension. Combining this approach with knowledge of the geometry of feasible integer solutions yields an algorithm for solving highly symmetric integer linear programs which only takes time which is linear in the number of constraints and quadratic in the dimension.
Nanostructured magnetic materials
Chan, Keith T.
2011-01-01T23:59:59.000Z
Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface
Non-linear Plasma Wake Growth of Electron Holes
Hutchinson, I H; Zhou, C
2015-01-01T23:59:59.000Z
An object's wake in a plasma with small Debye length that drifts \\emph{across} the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind wake and probes in magnetized laboratory plasmas. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. The gradients arise because the plasma wake has a region of depressed density and electrostatic potential into which ions are attracted along the field. The non-linear consequences of the instability are analysed in this paper. At physical ratios of electron to ion mass, neither linear nor quasilinear treatment can explain the observation of large-amplitude perturbations that disrupt the ion streams well before they become ion-ion unstable. We show here, however, that electron holes, once formed, continue to grow, driven by the drift mechanism, and if they remain in the wake may reach a maximum non-linearly stable...
Charged relativistic fluids and non-linear electrodynamics
T. Dereli; R. W. Tucker
2010-01-08T23:59:59.000Z
The electromagnetic fields in Maxwell's theory satisfy linear equations in the classical vacuum. This is modified in classical non-linear electrodynamic theories. To date there has been little experimental evidence that any of these modified theories are tenable. However with the advent of high-intensity lasers and powerful laboratory magnetic fields this situation may be changing. We argue that an approach involving the self-consistent relativistic motion of a smooth fluid-like distribution of matter (composed of a large number of charged or neutral particles) in an electromagnetic field offers a viable theoretical framework in which to explore the experimental consequences of non-linear electrodynamics. We construct such a model based on the theory of Born and Infeld and suggest that a simple laboratory experiment involving the propagation of light in a static magnetic field could be used to place bounds on the fundamental coupling in that theory. Such a framework has many applications including a new description of the motion of particles in modern accelerators and plasmas as well as phenomena in astrophysical contexts such as in the environment of magnetars, quasars and gamma-ray bursts.
Linear conic optimization for nonlinear optimal control
Didier Henrion
2014-07-07T23:59:59.000Z
Jul 7, 2014 ... Abstract: Infinite-dimensional linear conic formulations are described for nonlinear optimal control problems. The primal linear problem consists ...
Stochastic linear programming games with concave preferences
2014-12-04T23:59:59.000Z
We study stochastic linear programming games: a class of stochastic ... be seen as linear programming games; examples include assignment games (Shapley ...
SUPERCONDUCTING MAGNETIC ENERGY STORAGE
Hassenzahl, W.
2011-01-01T23:59:59.000Z
Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Up: APS Storage Ring Parameters Previous: Longitudinal bunch profile and Magnets and Power Supplies Dipole Magnets and Power Supplies Value Dipole Number 80+1 No. of power...
High dimensional linear inverse modelling
Cooper, Fenwick C
2015-01-01T23:59:59.000Z
We introduce and demonstrate two linear inverse modelling methods for systems of stochastic ODE's with accuracy that is independent of the dimensionality (number of elements) of the state vector representing the system in question. Truncation of the state space is not required. Instead we rely on the principle that perturbations decay with distance or the fact that for many systems, the state of each data point is only determined at an instant by itself and its neighbours. We further show that all necessary calculations, as well as numerical integration of the resulting linear stochastic system, require computational time and memory proportional to the dimensionality of the state vector.
Highly linear low noise amplifier
Ganesan, Sivakumar
2007-09-17T23:59:59.000Z
VgVgVgi (4) Where gm1 is its transconductance, gm2 represents its second order non-linearity obtained by the second order derivative of FET transfer characteristics (Id-Vgs) and gm3 is its third order non-linearity obtained by the third order... for the above mentioned currents are given below. 3 3213 2 21211 3 3 3 3 2 21 *),,(*),(*)( xxxBAout BbB AaAaAaA VsssCVssCVsCiii Vgi VgVgVgi ++=+= = ++= (14) Where g1a represents the transconductance of the main amplifier and g2a and g3a represent the second...
Knot undulator to generate linearly polarized photons with low on-axis power density
Qiao, S; Feng, Donglai; Hussain, Z; Shen, Z -X
2008-01-01T23:59:59.000Z
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.
Linear electric field mass spectrometry
McComas, D.J.; Nordholt, J.E.
1992-12-01T23:59:59.000Z
A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.
Linear regression issues in astronomy
Babu, G. Jogesh
Linear regression issues in astronomy Eric Feigelson Summer School in astrostatistics References regression Seeking the intrinsic relationship between two properties without specifying `dependent' and `independent' variables OLS(Y|X) OLS(X|Y) (inverse regr) Four symmetrical regression lines #12;Analytical
Magnetic Fields and Large Scale Structure in a hot Universe. I. General Equations
E. Battaner; E. Florido; J. Jimenez-Vicente
1997-10-06T23:59:59.000Z
We consider that no mean magnetic field exists during this epoch, but that there is a mean magnetic energy associated with large-scale magnetic inhomogeneities. We study the evolution of these inhomogeneities and their influence on the large scale density structure, by introducing linear perturbations in Maxwell equations, the conservation of momentum-energy equation, and in Einstein field equations. The primordial magnetic field structure is time independent in the linear approximation, only being diluted by the general expansion, so that $\\vec{B}R^2$ is conserved in comoving coordinates. Magnetic fields have a strong influence on the formation of large-scale structure. Firstly, relatively low fields are able to generate density structures even if they were inexistent at earlier times. Second, magnetic fields act anisotropically more recently, modifying the evolution of individual density clouds. Magnetic flux tubes have a tendency to concentrate photons in filamentary patterns.
Sikes, Derek S.
MATH F314-F71 Linear Algebra Summer 2014 Instructor: Dr. Dana E. Madison, demadison2@alaska is by email. Class Dates and Times: July 7 August 14, 12:00pm 1:50pm Textbook: Linear Algebra and its: This is a first course in linear algebra that starts with the basic objects vectors, matrices, systems of linear
Termination of Linear Programs Ashish Tiwari
Tiwari, Ashish
Termination of Linear Programs Ashish Tiwari SRI International, 333 Ravenswood Ave, Menlo Park, CA, U.S.A tiwari@csl.sri.com Abstract. We show that termination of a class of linear loop programs is decidable. Linear loop programs are discrete-time linear systems with a loop condition governing termination
Termination of Linear Programs Ashish Tiwari #
Tiwari, Ashish
Termination of Linear Programs Ashish Tiwari # SRI International, 333 Ravenswood Ave, Menlo Park, CA, U.S.A tiwari@csl.sri.com Abstract. We show that termination of a class of linear loop programs is decidable. Linear loop programs are discreteÂtime linear systems with a loop condition governing termination
Fast exact linear algebra, LinBox
Pernet, Clément
Fast exact linear algebra, LinBox Clément Pernet Introduction LinBox: an overview Principles-place eliminations Fast matrix multiplication Linear algebra over big integers Fast exact linear algebra: LinBox Clément PERNET SAGE Days 6, November 11, 2007 #12;Fast exact linear algebra, LinBox Clément Pernet
PROCESS CONTROLLABILITY ANALYSIS USING LINEAR AND NONLINEAR
Skogestad, Sigurd
PROCESS CONTROLLABILITY ANALYSIS USING LINEAR AND NONLINEAR OPTIMISATION Samara D. Chenery October linear and nonlinear dynamic optimisation techniques. For the linear case an optimal control problem is formulated to assess the best achievable performance for the set of linear time invariant (LTI) controllers
The Next Linear Collider Klystron Development Program*
E. Jongewaard; G. Caryotakis; C. Pearson; R. M. Phillips; D. Sprehn; A. Vlieks
2000-08-19T23:59:59.000Z
Klystrons capable of 75 MW output power at 11.4 GHz have been under development at SLAC for the last decade. The work has been part of the program to realize all the components necessary for the construction of the Next Linear Collider (NLC). The effort has produced a family of solenoid-focused 50 MW klystrons, which are currently powering a 0.5 GeV test accelerator at SLAC and several test stands, where high power components are evaluated and fundamental research is performed studying rf breakdown and dark current production. Continuing development has resulted in a Periodic Permanent Magnet (PPM) focused 50 MW klystron, tested at SLAC and subsequently contracted for manufacture by industry in England and Japan. A 75 MW version of that PPM klystron was built at SLAC and reached 75 MW, with 2.8 microsecond pulses. Based on this design, a prototype 75 MW klystron, designed for low-cost manufacture, is currently under development at SLAC, and will eventually be procured from industry in modest quantities for advanced NLC tests. Beyond these developments, the design of Multiple Beam Klystrons (MBKs) is under study at SLAC. MBKs offer the possibility of considerably lower modulator costs by producing comparable power to the klystrons now available, at much lower voltages. * This work supported by the Department of Energy under contract DE-AC03-76SF00515
Why quantum dynamics is linear
Thomas F. Jordan
2007-02-16T23:59:59.000Z
Quantum dynamics is linear. How do we know? From theory or experiment? The history of this question is reviewed. Nonlinear generalizations of quantum mechanics have been proposed. They predict small but clear nonlinear effects, which very accurate experiments have not seen. Is there a reason in principle why nonlinearity is not found? Is it impossible? Does quantum dynamics have to be linear? Attempts to prove this have not been decisive, because either their assumptions are not compelling or their arguments are not conclusive. The question has been left unsettled. There is a simple answer, based on a simple assumption. It was found in two steps separated by 44 years. They are steps back to simpler and more compelling assumptions. A proof of the assumptions of the Wigner-Bargmann proof has been known since 1962. It assumes that the maps of density matrices in time are linear. For this step, it is also assumed that density matrices are mapped one-to-one onto density matrices. An alternative is to assume that pure states are mapped one-to-one onto pure states and that entropy does not decrease. In a step taken in 2006, it is proved that the maps of density matrices in time are linear. It is assumed, as in the earlier step, that at each time the physical quantities and states are described by the usual linear structures of quantum mechanics, so the question is only about how things change in time. Beyond that, the proof assumes only that the dynamics does not depend on anything outside the system, but must allow the system to be described as part of a larger system.
Linear Gain for the Microbunching Instability in an RF Compressor
Venturini, M.; Migliorati, M.; Ronsivalle, C.; Vaccarezza, C.
2009-05-01T23:59:59.000Z
Velocity (or rf) compression has been suggested as a technique for bunch compression complementary to the more established technique involving magnetic chicanes and represents an important research item being investigated at the SPARC test facility. One of the aspects of this technique still not sufficiently understood is its possible impact on the microbunching instability. The purpose of this report is to present the analytical framework for investigating this instability in rf compressors. We use methods similar to those successfully applied to magnetic compressors and derive some integral equations yielding the gain for the instability in linear approximation. The focus here is on the derivation of the relevant equations. Although examples of solutions to these equations are provided we defer a more comprehensive discussion of their implication to a future report. The present study is part of a larger effort for a more comprehensive investigation that eventually will include macroparticle simulations and experiments.
Electromagnetic field quantization in a linear dielectric medium
F. Kheirandish; M. Amooshahi
2005-11-13T23:59:59.000Z
By modeling a dielectric medium with two independent reservoirs, i.e., electric and magnetic reservoirs, the electromagnetic field is quantized in a linear dielectric medium consistently. A Hamiltonian is proposed from which using the Heisenberg equations, not only the Maxwell equations but also the structural equations can be obtained. Using the Laplace transformation, the wave equation for the electromagnetic vector potential is solved in the case of a homogeneous dielectric medium. Some examples are considered showing the applicability of the model to both absorptive and nonabsorptive dielectrics.
The 4th Concept Detector for the International Linear Collider
Sung Keun Park; Franco Grancagnolo; John Hauptman; Alexander Mikhailichenko; Nural Akchurin
2007-08-06T23:59:59.000Z
The 4th Concept detector presently being designed for the International Linear Collider introduces several innovations in order to achieve the necessary experimental goal of a detecter that is 2-to-10 times better than the already excellent SLC and LEP detectors. We introduce a dual-readout calorimeter system, a cluster counting drift chamber, and a second solenoid to return the magnetic flux without iron. We discuss particle identification, momentum and energy resolutions, and the machine-detector interface that together offer the possibility of a very high-performance detector for e^+e^-physics up to $\\sqrt{s} = 1$ TeV.
Introduction Magnetic Anisotropy of
Rossak, Wilhelm R.
not completely understood interesting for dilute magnetic semiconductors (DMSs) transparent ferromagnets
Large Scale Approximate Inference and Experimental Design for Sparse Linear Models
Seeger, Matthias
Large Scale Approximate Inference and Experimental Design for Sparse Linear Models Matthias W.kyb.tuebingen.mpg.de/bs/people/seeger/ 27 June 2008 Matthias W. Seeger (MPI BioCyb) Large Scale Bayesian Experimental Design 27/6/08 1 / 27 Algorithms 4 Magnetic Resonance Imaging Sequences Matthias W. Seeger (MPI BioCyb) Large Scale Bayesian
Set Linear Algebra and Set Fuzzy Linear Algebra
W. B. Vasantha Kandasamy; Florentin Smarandache; K. Ilanthenral
2008-06-17T23:59:59.000Z
In this book, the authors define the new notion of set vector spaces which is the most generalized form of vector spaces. Set vector spaces make use of the least number of algebraic operations, therefore, even a non-mathematician is comfortable working with it. It is with the passage of time, that we can think of set linear algebras as a paradigm shift from linear algebras. Here, the authors have also given the fuzzy parallels of these new classes of set linear algebras. This book is divided into seven chapters. The first chapter briefly recalls some of the basic concepts in order to make this book self-contained. Chapter two introduces the notion of set vector spaces which is the most generalized concept of vector spaces. Set vector spaces lends itself to define new classes of vector spaces like semigroup vector spaces and group vector spaces. These are also generalization of vector spaces. The fuzzy analogue of these concepts are given in Chapter three. In Chapter four, set vector spaces are generalized to biset bivector spaces and not set vector spaces. This is done taking into account the advanced information technology age in which we live. As mathematicians, we have to realize that our computer-dominated world needs special types of sets and algebraic structures. Set n-vector spaces and their generalizations are carried out in Chapter five. Fuzzy n-set vector spaces are introduced in the sixth chapter. The seventh chapter suggests more than three hundred problems.
Ferrofluid spin-up flows from uniform and non-uniform rotating magnetic fields
Khushrushahi, Shahriar Rohinton
2010-01-01T23:59:59.000Z
When ferrofluid in a cylindrical container is subjected to a rotating azimuthally directed magnetic field, the fluid "spins up" into an almost rigid-body rotation where ferrofluid nanoparticles have both a linear and an ...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhu, S.; Cai, Y.; Rote, D.M.; Chen, S.S.
1998-01-01T23:59:59.000Z
Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.
Use of miniature magnetic sensors for real-time control of the induction heating process
Bentley, Anthony E. (Tijeras, NM); Kelley, John Bruce (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)
2002-01-01T23:59:59.000Z
A method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, B.sub.sat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).
Closed loop control of the induction heating process using miniature magnetic sensors
Bentley, Anthony E.; Kelley, John Bruce; Zutavern, Fred J.
2003-05-20T23:59:59.000Z
A method and system for providing real-time, closed-loop control of the induction hardening process. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, B.sub.sat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).
The magnetic shielding for the neutron decay spectrometer aSPECT
Gertrud Konrad; Fidel Ayala Guardia; Stefan Baeßler; Michael Borg; Ferenc Glück; Werner Heil; Stefan Hiebel; Raquel Munoz Horta; Yury Sobolev
2014-05-05T23:59:59.000Z
Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeability. The results of our simulations were checked through magnetic field measurements both with Hall and nuclear magnetic resonance probes. The experimental data are in good agreement with the simulated values: The mean deviation from the simulated exterior magnetic field is (-1.7+/-4.8)%. However, in the two critical regions, the internal magnetic field deviates by 0.2% respectively <1E-4 from the simulated values.
Linear accelerator for radioisotope production
Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.
1982-02-01T23:59:59.000Z
A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-..mu..A beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.
Linear-optical generation of eigenstates of the two-site XY model
Stefanie Barz; Borivoje Dakic; Yannick Ole Lipp; Frank Verstraete; James D. Whitfield; Philip Walther
2014-10-04T23:59:59.000Z
Much of the anticipation accompanying the development of a quantum computer relates to its application to simulating dynamics of another quantum system of interest. Here we study the building blocks for simulating quantum spin systems with linear optics. We experimentally generate the eigenstates of the XY Hamiltonian under an external magnetic field. The implemented quantum circuit consists of two CNOT gates, which are realized experimentally by harnessing entanglement from a photon source and by applying a CPhase gate. We tune the ratio of coupling constants and magnetic field by changing local parameters. This implementation of the XY model using linear quantum optics might open the door to the future studies of quenching dynamics using linear optics.
Large linear magnetoresistance in a GaAs/AlGaAs heterostructure
Aamir, Mohammed Ali, E-mail: aamir@physics.iisc.ernet.in; Goswami, Srijit, E-mail: aamir@physics.iisc.ernet.in; Ghosh, Arindam [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Baenninger, Matthias; Farrer, Ian; Ritchie, David A. [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Tripathi, Vikram [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Pepper, Michael [Department of Electrical and Electronic Engineering, University College, London WC1E 7JE (United Kingdom)
2013-12-04T23:59:59.000Z
We report non-saturating linear magnetoresistance (MR) in a two-dimensional electron system (2DES) at a GaAs/AlGaAs heterointerface in the strongly insulating regime. We achieve this by driving the gate voltage below the pinch-off point of the device and operating it in the non-equilibrium regime with high source-drain bias. Remarkably, the magnitude of MR is as large as 500% per Tesla with respect to resistance at zero magnetic field, thus dwarfing most non-magnetic materials which exhibit this linearity. Its primary advantage over most other materials is that both linearity and the enormous magnitude are retained over a broad temperature range (0.3 K to 10 K), thus making it an attractive candidate for cryogenic sensor applications.
Linearized supergravity from Matrix theory
D. Kabat; W. Taylor
1998-03-10T23:59:59.000Z
We show that the linearized supergravity potential between two objects arising from the exchange of quanta with zero longitudinal momentum is reproduced to all orders in 1/r by terms in the one-loop Matrix theory potential. The essential ingredient in the proof is the identification of the Matrix theory quantities corresponding to moments of the stress tensor and membrane current. We also point out that finite-N Matrix theory violates the equivalence principle.
Precision linear ramp function generator
Jatko, W. Bruce (Knoxville, TN); McNeilly, David R. (Maryville, TN); Thacker, Louis H. (Knoxville, TN)
1986-01-01T23:59:59.000Z
A ramp function generator is provided which produces a precise linear ramp unction which is repeatable and highly stable. A derivative feedback loop is used to stabilize the output of an integrator in the forward loop and control the ramp rate. The ramp may be started from a selected baseline voltage level and the desired ramp rate is selected by applying an appropriate constant voltage to the input of the integrator.
Precision linear ramp function generator
Jatko, W.B.; McNeilly, D.R.; Thacker, L.H.
1984-08-01T23:59:59.000Z
A ramp function generator is provided which produces a precise linear ramp function which is repeatable and highly stable. A derivative feedback loop is used to stabilize the output of an integrator in the forward loop and control the ramp rate. The ramp may be started from a selected baseline voltage level and the desired ramp rate is selected by applying an appropriate constant voltage to the input of the integrator.
Segmented rail linear induction motor
Cowan, M. Jr.; Marder, B.M.
1996-09-03T23:59:59.000Z
A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.
Cast dielectric composite linear accelerator
Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)
2009-11-10T23:59:59.000Z
A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.
Optimal Constructions of Fault Tolerant Optical Linear Compressors and Linear Decompressors
Chang, Cheng-Shang
1 Optimal Constructions of Fault Tolerant Optical Linear Compressors and Linear Decompressors Cheng linear compressors and linear decompressors. The basic network element for our constructions is scaled first obtain a fundamental result on the minimum con- struction complexity of a linear compressor
Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets
None
2010-10-01T23:59:59.000Z
Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.
Mueller, Fred M. (Los Alamos, NM); Bronisz, Lawrence (Los Alamos, NM); Grube, Holger (Los Alamos, NM); Nelson, David C. (Santa Fe, NM); Mace, Jonathan L. (Los Alamos, NM)
2006-11-14T23:59:59.000Z
A magnetic infrasound sensor is produced by constraining a permanent magnet inside a magnetic potential well above the surface of superconducting material. The magnetic infrasound sensor measures the position or movement of the permanent magnet within the magnetic potential well, and interprets the measurements. Infrasound sources can be located and characterized by combining the measurements from one or more infrasound sensors. The magnetic infrasound sensor can be tuned to match infrasound source types, resulting in better signal-to-noise ratio. The present invention can operate in frequency modulation mode to improve sensitivity and signal-to-noise ratio. In an alternate construction, the superconductor can be levitated over a magnet or magnets. The system can also be driven, so that time resolved perturbations are sensed, resulting in a frequency modulation version with improved sensitivity and signal-to-noise ratio.
The Electronic Journal of Linear Algebra. A publication of the International Linear Algebra Society.
Grudsky, Sergei
The Electronic Journal of Linear Algebra. A publication of the International Linear Algebra Society. Introduction and main results. Let lp n 1 p 1 be the linear space C n with the lp norm, kxkp = X j jxjjp 1=p
Tamper resistant magnetic stripes
Naylor, Richard Brian (Albuquerque, NM); Sharp, Donald J. (Albuquerque, NM)
1999-01-01T23:59:59.000Z
This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.
Status of the NHMFL 60 tesla quasi-continuous magnet
Campbell, L.J.; Boenig, H.J.; Rickel, D.G.; Schilig, J.B.; Sims, J.R. [Los Alamos National Lab., NM (United States); Schneider-Muntau, H.J. [National High Magnetic Field Laboratory (NHMFL), Tallahassee, FL (United States)
1995-07-01T23:59:59.000Z
All components of the National High Magnetic Field Laboratory`s (NHMFL) 60 T quasi-continuous magnet are now under construction, with complete delivery and installation expected in early 1996. This research magnet has a cold bore of 32 mm and will produce a constant 60 tesla for 100 ms plus a wide variety of other pulse shapes such as linear ramps, steps, crowbar decays, and longer flat-tops at lower fields. Fabrication and testing of prototype coils are described along with the layout, construction status, and protection philosophy of the 400 MW power supply. Examples of simulated pulse shapes are shown.
Byrne, J. M.; Telling, N. D.; Coker, V. S.; Pattrick, R. A. D.; Laan, G. van der; Arenholz, E.; Tuna, F.; Lloyd, J. R.
2011-08-02T23:59:59.000Z
The bioproduction of nano-scale magnetite by Fe(III)-reducing bacteria offers a potentially tunable, environmentally benign route to magnetic nanoparticle synthesis. Here, we demonstrate that it is possible to control the size of magnetite nanoparticles produced by Geobacter sulfurreducens, by adjusting the total biomass introduced at the start of the process. The particles have a narrow size distribution and can be controlled within the range of 10-50 nm. X-ray diffraction analysis indicates that controlled production of a number of different biominerals is possible via this method including goethite, magnetite and siderite, but their formation is strongly dependent upon the rate of Fe(III) reduction and total concentration and rate of Fe(II) produced by the bacteria during the reduction process. Relative cation distributions within the structure of the nanoparticles has been investigated by X-ray magnetic circular dichroism and indicates the presence of a highly reduced surface layer which is not observed when magnetite is produced through abiotic methods. The enhanced Fe(II)-rich surface, combined with small particle size, has important environmental applications such as in the reductive bioremediation of organics, radionuclides and metals. In the case of Cr(VI), as a model high-valence toxic metal, optimised biogenic magnetite is able to reduce and sequester the toxic hexavalent chromium very efficiently in the less harmful trivalent form.
Electronic and magnetic properties of iron doped zirconia: Theory and experiment
Debernardi, A., E-mail: alberto.debernardi@mdm.imm.cnr.it; Sangalli, D.; Lamperti, A.; Cianci, E. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (MB) (Italy); Lupo, P.; Casoli, F.; Albertini, F.; Nasi, L. [CNR-IMEM, Parco Area delle Scienze 37/A, 43124 Parma (Italy); Ciprian, R.; Torelli, P. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy)
2014-05-07T23:59:59.000Z
We systematically investigated, both theoretically and experimentally, Zr{sub 1?x}Fe{sub x}O{sub 2?y} ranging from diluted (x???0.05) up to large (x???0.25) Fe concentration. By atomic layer deposition, we grew thin films of high-? zirconia in cubic phase with Fe uniformly distributed in the film, as proven by time of flight secondary ion mass spectrometry and transmission electron microscopy measurements. Iron is in Fe{sup 3+} oxidation state suggesting the formation of oxygen vacancies with y concentration close to x/2. By ab-initio simulations, we studied the phase diagram relating the stability of monoclinic vs. tetragonal phase as a function of Fe doping and film thickness: the critical thickness at which the pure zirconia is stabilized in the tetragonal phase is estimated ranging from 2 to 6?nm according to film morphology. Preliminary results by X-ray magnetic circular dichroism and alternating gradient force magnetometry are discussed in comparison to ab initio data enlightening the role of oxygen vacancies in the magnetic properties of the system.
D. B. Papadopoulos
2003-12-23T23:59:59.000Z
The equations which determine the response of a spinning charged particle moving in a uniform magnetic field to an incident gravitational wave are derived in the linearized approximation to general relativity. We verify that 1) the components of the 4-momentum, 4-velocity and the components of the spinning tensor, both electric and magnetic moments, exhibit resonances and 2) the co-existence of the uniform magnetic field and the GW are responsible for the resonances appearing in our equations. In the absence of the GW, the magnetic field and the components of the spin tensor decouple and the magnetic resonances disappear.
Magnet reliability in the Fermilab Main Injector and implications for the ILC
Tartaglia, M.A.; Blowers, J.; Capista, D.; Harding, D.J.; Kiemschies, O.; Rahimzadeh-Kalaleh, S.; Tompkins, J.C.; /Fermilab
2007-08-01T23:59:59.000Z
The International Linear Collider reference design requires over 13000 magnets, of approximately 135 styles, which must operate with very high reliability. The Fermilab Main Injector represents a modern machine with many conventional magnet styles, each of significant quantity, that has now accumulated many hundreds of magnet-years of operation. We review here the performance of the magnets built for this machine, assess their reliability and categorize the failure modes, and discuss implications for reliability of similar magnet styles expected to be used at the ILC.
Linear-quadratic control problem with a linear term on semiinfinite ...
2003-12-18T23:59:59.000Z
Dec 15, 2003 ... We describe a complete solution of the linear-quadratic control prob- lem on a semiinfinite interval with the linear term in the objective func-.
Otani, Yoshichika
Controlled propagation of locally excited vortex dynamics in linear nanomagnet arrays This article. Here, we present a controlled propagation of locally excited magnetic vortex dynamics through a linear. Phys. D: Appl. Phys. 43 (2010) 335001 (7pp) doi:10.1088/0022-3727/43/33/335001 Controlled propagation
Proceedings of the International Linear Collider Workshop
Proceedings of the International Linear Collider Workshop LCWS 2007 ILC 2007 Volume 1 Edited by Ariane Frey Sabine Riemann #12;Impressum Proceedings of the International Linear Collider Workshop LCWS
Ultrashort Pulse Propagation in the Linear Regime
Wang, Jieyu
2010-07-14T23:59:59.000Z
First, we investigate the Bouguer-Lambert-Beer (BLB) law as applied to the transmission of ultrashort pulses through water in the linear absorption regime. We present a linear theory for propagation of ultrashort laser ...
MANEUVER REGULATION, TRANSVERSE FEEDBACK LINEARIZATION, AND ZERO
Maggiore, Manfredi
MANEUVER REGULATION, TRANSVERSE FEEDBACK LINEARIZATION, AND ZERO DYNAMICS Chris Nielsen,1 Manfredi focus is on output maneuver regulation where stabilizing transverse dynamics is a key requirement. Keywords: Maneuver regulation, path following, feedback linearization, zero dynamics, non-square systems
High speed linear induction motor efficiency optimization
Johnson, Andrew P. (Andrew Peter)
2005-01-01T23:59:59.000Z
One of the reasons linear motors, a technology nearly a century old, have not been adopted for a large number of linear motion applications is that they have historically had poor efficiencies. This has restricted the ...
Duality for Mixed-Integer Linear Programs
2007-04-05T23:59:59.000Z
The theory of duality for linear programs is well-developed and has been successful ... methods for determining the effect of modifications to the input data on the ..... and the primal problem is bounded, since linear programming duality tells us ...
Linear Regression and Support Vector Regression
Shi, Qinfeng "Javen"
Linear Regression and Support Vector Regression Paul Paisitkriangkrai paulp@cs.adelaide.edu.au The University of Adelaide 18 August 2014 #12;Outlines · Regression overview · Linear regression · Support vector regression · Machine learning tools available #12;Regression Overview CLUSTERING CLASSIFICATION REGRESSION
Linear Accelerator | Advanced Photon Source
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Seismic response of linear accelerators
Collette, C; Guinchard, M; Hauviller, C
2010-01-01T23:59:59.000Z
This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.
Stochastic bridges of linear systems
Yongxin Chen; Tryphon Georgiou
2014-07-12T23:59:59.000Z
We study a generalization of the Brownian bridge as a stochastic process that models the position and velocity of inertial particles between the two end-points of a time interval. The particles experience random acceleration and are assumed to have known states at the boundary. Thus, the movement of the particles can be modeled as an Ornstein-Uhlenbeck process conditioned on position and velocity measurements at the two end-points. It is shown that optimal stochastic control provides a stochastic differential equation (SDE) that generates such a bridge as a degenerate diffusion process. Generalizations to higher order linear diffusions are considered.
SELF-SCHEDULED H1 CONTROLLERS FOR MAGNETIC BEARINGS Panagiotis Tsiotras
Tsiotras, Panagiotis
their very low power consumption (an order of magnitude lower than oil lm bear- ings) and their very long of magnetic bearings. Most of these techniques assume a linear time-invariant (LTI) plant. Such an assumption over a wide range, the linear time-invariant assumption may no longer be valid because the dynamics
Generation of shear Alfvn waves by a rotating magnetic field source: Three-dimensional simulations
Carter, Troy
an ambient magnetic field,57 SAW can transport energy efficiently. The SAW can drive plasma currents results with the experimental measurements and the linear shear Alfvén wave properties, namely that the energy of the Alfvén wave generated by the rotating magnetic field source is distributed between
Linear Programming Lower Bounds for Minimum Converter ...
generation algorithm for solving the linear relaxation of the most promising ... Keywords: Optical Networks, Wavelength Assignment, Integer Programming.
Symmetries in Linear and Integer Programs
Bödi, R
2009-01-01T23:59:59.000Z
The notion of symmetry is defined in the context of Linear and Integer Programming. Symmetric linear and integer programs are studied from a group theoretical viewpoint. We show that for any linear program there exists an optimal solution in the fixed point set of its symmetry group. Using this result, we develop an algorithm that allows for reducing the dimension of any linear program having a non-trivial group of symmetries.
Superconducting wiggler magnets for beam-emittance damping rings
Schoerling, Daniel
2012-01-01T23:59:59.000Z
Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....
Magnetic Graphene Nanohole Superlattices
Yu, Decai; Liu, Miao; Liu, Wei; Liu, Feng
2008-01-01T23:59:59.000Z
We investigate the magnetic properties of nano-holes (NHs) patterned in graphene using first principles calculations. We show that superlattices consisting of a periodic array of NHs form a new family of 2D crystalline "bulk" magnets whose collective magnetic behavior is governed by inter-NH spin-spin interaction. They exhibit long-range magnetic order well above room temperature. Furthermore, magnetic semiconductors can be made by doping magnetic NHs into semiconducting NH superlattices. Our findings offer a new material system for fundamental studies of spin-spin interaction and magnetic ordering in low dimensions, and open up the exciting opportunities of making engineered magnetic materials for storage media and spintronics applications.
Barclay, John A. (Los Alamos, NM); Steyert, William A. (Los Alamos, NM)
1982-01-01T23:59:59.000Z
The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.
Varying-Coefficient Functional Linear Regression Models
Cardot, Hervé
Varying-Coefficient Functional Linear Regression Models Herv´e Cardot1 and Pascal Sarda2 1, the ability of such non linear functional approaches to produce competitive estimations. Short title : Varying monograph. We propose here another generalization of the functional linear regression model in which
Computational Reality XIII Non-linear regression
Berlin,Technische Universität
Computational Reality XIII Non-linear regression Inverse analysis II B. Emek Abali @ LKM - TU Berlin Abstract Linear regression to fit and determine parameters, shown in the last tutorial, is quite useful and widely implemented, however, there are material models where parameters are coupled non-linearly
On linear programing approach to inventory control
Mayfield, John
On linear programing approach to inventory control problems Zhu received his PhD from Wayne State imbeds the inventory control problem into an infinite-dimensional linear program over a space of measures restricted classes of control policies. Additional auxiliary and dual linear programs are introduced
Depolarization of backscattered linearly polarized light
Lacoste, David
Depolarization of backscattered linearly polarized light Luis Fernando Rojas-Ochoa Department of backscattered linearly polarized light with an extended photon dif- fusion formalism taking explicitly, the characteristic depolarization length for linearly polarized light, lp , is deduced. We investigate the dependence
MINIMIZING COMMUNICATION IN NUMERICAL LINEAR ALGEBRA*
California at Berkeley, University of
MINIMIZING COMMUNICATION IN NUMERICAL LINEAR ALGEBRA* GREY BALLARD , JAMES DEMMEL , OLGA HOLTZ, i.e., essentially all direct methods of linear al- gebra. The proof works for dense or sparse our lower bound technique to compositions of linear algebra operations (like computing powers
Batch-mode Supervised Learning Linear regression
Wehenkel, Louis
Batch-mode Supervised Learning Linear regression Applied inductive learning - Lecture 3 Louis (& Pierre Geurts)AIA... (1/19) #12;Batch-mode Supervised Learning Linear regression Batch-mode Supervised Learning Linear regression Least mean square error solution Regularization and algorithmics Residual
Magnetic field restructuring associated with two successive solar eruptions
Wang, Rui; Liu, Ying D.; Yang, Zhongwei; Hu, Huidong, E-mail: liuxying@spaceweather.ac.cn [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China)
2014-08-20T23:59:59.000Z
We examine two successive flare eruptions (X5.4 and X1.3) on 2012 March 7 in the NOAA active region 11429 and investigate the magnetic field reconfiguration associated with the two eruptions. Using an advanced non-linear force-free field extrapolation method based on the SDO/HMI vector magnetograms, we obtain a stepwise decrease in the magnetic free energy during the eruptions, which is roughly 20%-30% of the energy of the pre-flare phase. We also calculate the magnetic helicity and suggest that the changes of the sign of the helicity injection rate might be associated with the eruptions. Through the investigation of the magnetic field evolution, we find that the appearance of the 'implosion' phenomenon has a strong relationship with the occurrence of the first X-class flare. Meanwhile, the magnetic field changes of the successive eruptions with implosion and without implosion were well observed.
Performance of An Adjustable Strength Permanent Magnet Quadrupole
Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; /STI Optronics, Bellevue; Spencer, C.M.; /SLAC; Volk, J.T.; /Fermilab
2006-03-01T23:59:59.000Z
An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.
Magnetic Fields Analogous to electric field, a magnet
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Magnetic Fields Analogous to electric field, a magnet produces a magnetic field, B Set up a B field two ways: Moving electrically charged particles Current in a wire Intrinsic magnetic field Basic) Opposite magnetic poles attract like magnetic poles repel #12;Like the electric field lines
Magnetism Theory Group / POSTECH Magnetism Theory Group / POSTECH
Min, Byung Il
Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH J.H . Park et al. #12;'s of FeinCsm e tal The chargeandorbitalordering geom etryin YB a C o 2 O 5 S. K. Kwon etal .Magnetism Theory
Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert
2014-04-15T23:59:59.000Z
Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.
Magnetic nanohole superlattices
Liu, Feng
2013-05-14T23:59:59.000Z
A magnetic material is disclosed including a two-dimensional array of carbon atoms and a two-dimensional array of nanoholes patterned in the two-dimensional array of carbon atoms. The magnetic material has long-range magnetic ordering at a temperature below a critical temperature Tc.
Triggering for Magnetic Field Measurements of the LCLS Undulators
Hacker, Kirsten
2010-12-13T23:59:59.000Z
A triggering system for magnetic field measurements of the LCLS undulators has been built with a National Instruments PXI-1002 and a Xylinx FPGA board. The system generates single triggers at specified positions, regardless of encoder sensor jitter about a linear scale.
Impact of Dynamic Magnetic fields on the CLIC Main Beam
Snuverink, J; Jach, C; Jeanneret, JB; Schulte, D; Stulle, F
2010-01-01T23:59:59.000Z
The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the position of the beam. The beam position will be sensitive to external dynamic magnetic fields (stray fields) in the nanotesla regime. The impact of these fields on the CLIC main beam has been studied by performing simulations on the lattices and tolerances have been determined. Several mitigation techniques will be discussed.
Observation of low magnetic field density peaks in helicon plasma
Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2013-04-15T23:59:59.000Z
Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peak value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.
New PVLAS results and limits on magnetically induced optical rotation and ellipticity in vacuum
E. Zavattini; G. Zavattini; G. Raiteri; G. Ruoso; E. Polacco; E. Milotti; V. Lozza; M. Karuza; U. Gastaldi; G. Di Domenico; F. Della Valle; R. Cimino; S. Carusotto; G. Cantatore; M. Bregant
2007-11-22T23:59:59.000Z
IIn 2006 the PVLAS collaboration reported the observation of an optical rotation generated in vacuum by a magnetic field. To further check against possible instrumental artifacts several upgrades to the PVLAS apparatus have been made during the last year. Two data taking runs, at the wavelength of 1064 nm, have been performed in the new configuration with magnetic field strengths of 2.3 T and 5 T. The 2.3 T field value was chosen in order to avoid stray fields. The new observations do not show the presence of a rotation signal down to the levels of $1.2\\cdot 10^{-8}$ rad at 5 T and $1.0\\cdot 10^{-8}$ rad at 2.3 T (at 95% c.l.) with 45000 passes in the magnetic field zone. In the same conditions no ellipticity signal was detected down to $1.4\\cdot 10^{-8}$ at 2.3 T (at 95% c.l.), whereas at 5 T a signal is still present. The physical nature of this ellipticity as due to an effect depending on $B^2$ can be excluded by the measurement at 2.3 T. These new results completely exclude the previously published magnetically induced vacuum dichroism results, indicating that they were instrumental artifacts. These new results therefore also exclude the particle interpretation of the previous PVLAS results as due to a spin zero boson. The background ellipticity at 2.3 T can be used to determine a new limit on the total photon-photon scattering cross section of $\\sigma_{\\gamma\\gamma} < 4.5 \\cdot10^{-34}$ barn at 95% c.l..
Studies on the Interaction of DGCR8 with the Cofactor Heme.
Barr, Robert Ian
2012-01-01T23:59:59.000Z
magnetic circular dichroism, and electron paramagnetic resonance spectra of the DGCR8-heme complex suggest a ferric heme bearing
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2005; 12:683
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2005; 12:683 Published Numerical Linear Algebra and its Applications The fourth workshop of the ERCIM Working Group on `Matrix Computations and Statistics' and the First International workshop on `Numerical Linear Algebra and its
ENGI 3423 Simple Linear Regression Page 12-01 Simple Linear Regression
George, Glyn
for dealing with non-linear regression are available in the course text, but are beyond the scopeENGI 3423 Simple Linear Regression Page 12-01 Simple Linear Regression Sometimes an experiment predict the value of Y for that value of x . The simple linear regression model is that the predicted
Robust Linearization of RF Amplifiers Using NonLinear Internal Model Control Method
Paris-Sud XI, Université de
Robust Linearization of RF Amplifiers Using NonLinear Internal Model Control Method Smail Bachir #1, the nonlinear Internal Model Control (IMC) method is introduced and applied to linearize high frequency Power to be controlled [8]. If the model is a perfect representation of the non linear system, the controller can
Optimal Linear Quadratic Regulator for Markovian Jump Linear Systems, in the
Baras, John S.
, in the last fifteen, the classical paradigms of optimal control for Markovian jump linear systems (see CostaOptimal Linear Quadratic Regulator for Markovian Jump Linear Systems, in the presence of one time] and in the design of controllers Chizeck [1986] of controllers for Markovian jump linear systems. More specifically
Kunkel, Peter
The linear quadratic optimal control problem for linear descriptor systems with variable coefficients Peter Kunkel 3 Volker Mehrmann y 17.01.97 Abstract We study linear quadratic optimal control, 93B11, 93B40 1 Introduction In this paper we study the linearÂquadratic optimal control problem
Magnetically attached sputter targets
Makowiecki, D.M.; McKernan, M.A.
1994-02-15T23:59:59.000Z
An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.
Reticle stage based linear dosimeter
Berger, Kurt W.
2005-06-14T23:59:59.000Z
A detector to measure EUV intensity employs a linear array of photodiodes. The detector is particularly suited for photolithography systems that includes: (i) a ringfield camera; (ii) a source of radiation; (iii) a condenser for processing radiation from the source of radiation to produce a ringfield illumination field for illuminating a mask; (iv) a reticle that is positioned at the ringfield camera's object plane and from which a reticle image in the form of an intensity profile is reflected into the entrance pupil of the ringfield camera, wherein the reticle moves in a direction that is transverse to the length of the ringfield illumination field that illuminates the reticle; (v) detector for measuring the entire intensity along the length of the ringfield illumination field that is projected onto the reticle; and (vi) a wafer onto which the reticle imaged is projected from the ringfield camera.
Reticle stage based linear dosimeter
Berger, Kurt W. (Livermore, CA)
2007-03-27T23:59:59.000Z
A detector to measure EUV intensity employs a linear array of photodiodes. The detector is particularly suited for photolithography systems that includes: (i) a ringfield camera; (ii) a source of radiation; (iii) a condenser for processing radiation from the source of radiation to produce a ringfield illumination field for illuminating a mask; (iv) a reticle that is positioned at the ringfield camera's object plane and from which a reticle image in the form of an intensity profile is reflected into the entrance pupil of the ringfield camera, wherein the reticle moves in a direction that is transverse to the length of the ringfield illumination field that illuminates the reticle; (v) detector for measuring the entire intensity along the length of the ringfield illumination field that is projected onto the reticle; and (vi) a wafer onto which the reticle imaged is projected from the ringfield camera.
Kumar, Dinesh; Bhattacharyya, R. [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313001 (India)] [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313001 (India); Smolarkiewicz, P. K. [European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX (United Kingdom)] [European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX (United Kingdom)
2013-11-15T23:59:59.000Z
In ideal magnetohydrodynamics characterized by an infinite electrical conductivity, the magnetic flux across an arbitrary fluid surface is conserved in time. The magnetofluid then can be partitioned into contiguous subvolumes of fluid, each of which entraps its own subsystem of magnetic flux. During dynamical evolution of the magnetofluid, these subvolumes press into each other; and in the process, two such subvolumes may come into direct contact while ejecting a third interstitial subvolume. Depending on the orientations of magnetic fields of the two interacting subvolumes, the magnetic field at the common surface of interaction may become discontinuous and a current sheet is formed there. This process of current sheet formation and their subsequent decay is believed to be a plausible mechanism for coronal heating and may also be responsible for various eruptive phenomena at the solar corona. In this work, we explore this theoretical concept through numerical simulations of a viscous, incompressible magnetofluid characterized by infinite electrical conductivity. In particular, we show that if the initial magnetic field is prescribed by superposition of two linear force-free fields with different torsion coefficients, then formation of current sheets are numerically realizable in the neighborhood of magnetic nulls.
The chiral magnetic nanomotors
Morozov, Konstantin I
2013-01-01T23:59:59.000Z
Propulsion of the chiral magnetic nanomotors powered by a rotating magnetic field is in the focus of the modern biomedical applications. This technology relies on strong interaction of dynamic and magnetic degrees of freedom of the system. Here we study in detail various experimentally observed regimes of the helical nanomotor orientation and propulsion depending on the actuation frequency, and establish the relation of these two properties with remanent magnetization and geometry of the helical nanomotors. The theoretical predictions for the transition between the regimes and nanomotor orientation and propulsion speed are in excellent agreement with available experimental data. The proposed theory offers a few simple guidelines towards the optimal design of the magnetic nanomotors. In particular, efficient nanomotors should be fabricated of hard magnetics, e.g., cobalt, magnetized transversally and have the geometry of a normal helix with a helical angle of 35-45 degrees.
Implicit Methods for the Magnetohydrodynamic Description of Magnetically Confined Plasmas
S.C. Jardin
2010-09-28T23:59:59.000Z
Implicit algorithms are essential for predicting the slow growth and saturation of global instabilities in today’s magnetically confined fusion plasma experiments. Present day algorithms for obtaining implicit solutions to the magnetohydrodynamic (MHD) equations for highly magnetized plasma have their roots in algorithms used in the 1960s and 1970s. However, today’s computers and modern linear and non?linear solver techniques make practical much more comprehensive implicit algorithms than were previously possible. Combining these advanced implicit algorithms with highly accurate spatial representations of the vector fields describing the plasma flow and magnetic fields and with improved methods of calculating anisotropic thermal conduction now makes possible simulations of fusion experiments using realistic values of plasma parameters and actual configuration geometry.
Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions
Neggache, A. [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France); Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France); Hauet, T.; Petit-Watelot, S.; Boulet, P.; Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France); Bertran, F.; Le Fèvre, P.; Ohresser, P. [Synchrotron SOLEIL-CNRS, L'Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France); Devolder, T. [Institut d'Electronique Fondamentale, CNRS, UMR 8622, 91405 Orsay (France); Mewes, C. [Department of Physics and Astronomy/Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Maat, S.; Childress, J. R. [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)
2014-06-23T23:59:59.000Z
The ability of the full Heusler alloy Co{sub 1.5}Fe{sub 1.5}Ge(001) (CFG) to be a Half-Metallic Magnetic (HMM) material is investigated. Epitaxial CFG(001) layers were grown by molecular beam epitaxy. The results obtained using electron diffraction, X-ray diffraction, and X-ray magnetic circular dichroism are consistent with the full Heusler structure. The pseudo-gap in the minority spin density of state typical in HMM is examined using spin-resolved photoemission. Interestingly, the spin polarization found to be negative at E{sub F} in equimolar CoFe(001) is observed to shift to positive values when inserting Ge in CoFe. However, no pseudo-gap is found at the Fermi level, even if moderate magnetization and low Gilbert damping are observed as expected in HMM materials. Magneto-transport properties in MgO-based magnetic tunnel junctions using CFG electrodes are investigated via spin and symmetry resolved photoemission.
Bettarini, Lapo [Katholieke Universiteit Leuven, Centrum voor Plasma Astrofysica, Celestijnenlaan 200B, B-3001 Leuven (Belgium); Dipartimento di Astronomia e Scienza dello Spazio, Universita degli Studi di Firenze, Largo E. Fermi, 2, I-50125 Firenze (Italy); Landi, Simone [Dipartimento di Astronomia e Scienza dello Spazio, Universita degli Studi di Firenze, Largo E. Fermi, 2, I-50125 Firenze (Italy); Velli, Marco [Dipartimento di Astronomia e Scienza dello Spazio, Universita degli Studi di Firenze, Largo E. Fermi, 2, I-50125 Firenze (Italy); Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109 (United States); Londrillo, Pasquale [INAF Osservatorio Astronomico di Bologna, via C. Ranzani 1, I-40127 Bologna (Italy)
2009-06-15T23:59:59.000Z
The problem of three-dimensional combined magnetic and velocity shear driven instabilities of a compressible magnetized jet modeled as a plane neutral/current double vortex sheet in the framework of the resistive magnetohydrodynamics is addressed. The resulting dynamics given by the stream+current sheet interaction is analyzed and the effects of a variable geometry of the basic fields are considered. Depending on the basic asymptotic magnetic field configuration, a selection rule of the linear instability modes can be obtained. Hence, the system follows a two-stage path developing either through a fully three-dimensional dynamics with a rapid evolution of kink modes leading to a final turbulent state, or rather through a driving two-dimensional instability pattern that develops on parallel planes on which a reconnection+coalescence process takes place.
Multi-Stage Bunch Compressors for the International Linear Collider
Tenenbaum, Peter G.; Raubenheimer, Tor O.; Wolski, Andrzej
2005-01-01T23:59:59.000Z
FOR THE INTERNATIONAL LINEAR COLLIDER ? P. Tenenbaum † ,goals, the International Linear Collider (ILC) requires acompressors for the International Linear Collider. Each of
Non-Linear Seismic Soil Structure Interaction (SSI) Method for...
Office of Environmental Management (EM)
Non-Linear Seismic Soil Structure Interaction (SSI) Method for Developing Non-Linear Seismic SSI Analysis Techniques Non-Linear Seismic Soil Structure Interaction (SSI) Method for...
Automating approximate Bayesian computation by local linear regression
Thornton, Kevin R
2009-01-01T23:59:59.000Z
computation by local linear regression Kevin R Thorntonof ABC based on using a linear regression to approximate theimplements the local linear-regression approach to ABC. The
Rayleigh-Taylor instabilities with sheared magnetic fields
Ruderman, M. S. [Solar Physics and Space Plasma Research Centre (SP2RC), University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Terradas, J.; Ballester, J. L. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)
2014-04-20T23:59:59.000Z
Magnetic Rayleigh-Taylor (MRT) instabilities may play a relevant role in many astrophysical problems. In this work the effect of magnetic shear on the growth rate of the MRT instability is investigated. The eigenmodes of an interface and a slab model under the presence of gravity are analytically calculated assuming that the orientation of the magnetic field changes in the equilibrium, i.e., there is magnetic shear. We solve the linearized magnetohydrodynamic equations in the incompressible regime. We find that the growth rate is bounded under the presence of magnetic shear. We have derived simple analytical expressions for the maximum growth rate, corresponding to the most unstable mode of the system. These expressions provide the explicit dependence of the growth rate on the various equilibrium parameters. For small angles the growth time is linearly proportional to the shear angle, and in this regime the single interface problem and the slab problem tend to the same result. On the contrary, in the limit of large angles and for the interface problem the growth time is essentially independent of the shear angle. In this regime we have also been able to calculate an approximate expression for the growth time for the slab configuration. Magnetic shear can have a strong effect on the growth rates of the instability. As an application of the results found in this paper we have indirectly determined the shear angle in solar prominence threads using their lifetimes and the estimation of the Alfvén speed of the structure.
International Workshop on Linear Colliders 2010
None
2011-10-06T23:59:59.000Z
IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat IWLC2010 is hosted by CERN
Passive magnetic bearing system
Post, Richard F.
2014-09-02T23:59:59.000Z
An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.
JLab Supports International Linear Collider Cavity Development...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Supports International Linear Collider Cavity Development Work NEWPORT NEWS, Va. Feb. 12, 2008 - It's not often that major-league baseball and nuclear physics get to share the...
LED Replacements for Linear Fluorescent Lamps Webcast
Broader source: Energy.gov [DOE]
In this June 20, 2011 webcast on LED products marketed as replacements for linear fluorescent lamps, Jason Tuenge of the Pacific Northwest National Laboratory (PNNL) discussed current Lighting...
GENERALIZED DUAL FACE ALGORITHM FOR LINEAR ...
2014-10-02T23:59:59.000Z
1991 Mathematics Subject Classification. Primary 90C05; Secondary 65K05. Key words and phrases. linear programming, dual level face, dual optimal face .
Linear conic optimization for nonlinear optimal control
2014-07-07T23:59:59.000Z
Jul 7, 2014 ... This linear transport equation is classical in fluid mechanics, statistical ... define a relaxed optimal control problem as an LP in the cone of non-.
Optimization Online - Linear, Cone and Semidefinite Programming ...
Strong duality in conic linear programming: facial reduction and extended duals ... A new semide nite programming relaxation for the quadratic assignment ...
Optimization Online - Equivalence of an Approximate Linear ...
Alejandro Toriello
2013-02-07T23:59:59.000Z
Feb 7, 2013 ... Equivalence of an Approximate Linear Programming Bound with the Held-Karp Bound for the Traveling Salesman Problem. Alejandro Toriello ...
Ultra-high vacuum photoelectron linear accelerator
Yu, David U.L.; Luo, Yan
2013-07-16T23:59:59.000Z
An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.
Siting the International Linear Collider at Hanford
Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.
2012-03-15T23:59:59.000Z
Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facilityl.
Siting the International Linear Collider at Hanford
Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.
2012-05-01T23:59:59.000Z
Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facility.
Effect of trapping in a degenerate plasma in the presence of a quantizing magnetic field
Shah, H. A.; Iqbal, M. J.; Qureshi, M. N. S. [Department of Physics, GC University, Lahore 54000 (Pakistan); Tsintsadze, N. [Department of Physics, GC University, Lahore 54000 (Pakistan); Institute of Physics, Tbilisi 0177 (Georgia); Masood, W. [Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)
2012-09-15T23:59:59.000Z
Effect of trapping as a microscopic phenomenon in a degenerate plasma is investigated in the presence of a quantizing magnetic field. The plasma comprises degenerate electrons and non-degenerate ions. The presence of the quantizing magnetic field is discussed briefly and the effect of trapping is investigated by using the Fermi-Dirac distribution function. The linear dispersion relation for ion acoustic wave is derived in the presence of the quantizing magnetic field and its influence on the propagation characteristics of the linear ion acoustic wave is discussed. Subsequently, fully nonlinear equations for ion acoustic waves are used to obtain the Sagdeev potential and the investigation of solitary structures. The formation of solitary structures is studied both for fully and partially degenerate plasmas in the presence of a quantizing magnetic field. Both compressive and rarefactive solitons are obtained for different conditions of temperature and magnetic field.
Marts, D.J.; Richardson, J.G.; Albano, R.K.; Morrison, J.L. Jr.
1995-11-28T23:59:59.000Z
This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized. 2 figs.
Christiansen, D.W.; Brown, W.F.
1984-01-01T23:59:59.000Z
A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.
Linear optics, Raman scattering, and spin noise spectroscopy
Glazov, M M
2015-01-01T23:59:59.000Z
Spin noise spectroscopy (SNS) is a new method for studying magnetic resonance and spin dynamics based on measuring the Faraday rotation noise. In strong contrast with methods of nonlinear optics, the spectroscopy of spin noise is considered to be essentially nonperturbative. Presently, however, it became clear that the SNS, as an optical technique, demonstrates properties lying far beyond the bounds of conventional linear optics. Specifically, the SNS shows dependence of the signal on the light power density, makes it possible to penetrate inside an inhomogeneously broadened absorption band and to determine its homogeneous width, allows one to realize an effective pump-probe spectroscopy without any optical nonlinearity, etc. This may seem especially puzzling when taken into account that SNS can be considered just as a version of Raman spectroscopy, which is known to be deprived of such abilities. In this paper, we clarify this apparent inconsistency.
Magnetic Braids Anthony Yeates
Dundee, University of
flux function Main result Conclusion 2. Thermonuclear confinement devices. ITER (Internat'l Thermonuclear Experimental Reactor). Inside the KSTAR tokamak. Correspond to periodic magnetic braids. 4 / 22
Magnetically leviated superconducting bearing
Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)
1993-01-01T23:59:59.000Z
A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.
Royet, J.
2010-01-01T23:59:59.000Z
76SFOOO98. MAGNET CABLE MANUFACTURING John Royet Lawrenceused in this cable manufacturing are made of superconductingapplied during manufacturing. 2.2 Twist The composite
Design and Synthesis of Novel Linear and Cyclic Peptide Ligands for Kappa Opioid Receptors
Fang, Weijie
2008-09-04T23:59:59.000Z
; Nal(2?): 2-naphthylalanine; Nbb: nitrobenzamidobenzyl; Nle: norleucine; norBNI: nor-binaltorphimine; NMR: nuclear magnetic resonance; NSAID: non-steroidal anti-inflammatory drug; OAll: O-allyl; oNBS: ortho-nitrobenzenesulfonyl; ORL-1: opioid... (both linear and cyclic analogs) for ?- opioid receptors have been identified, 1, 25 until recently the search for peptide antagonists 4 has met with limited success. Compounds in which the N-terminus was converted to a tertiary amine...
The Equivalence of Linear Programs and Zero-Sum Games
2012-01-15T23:59:59.000Z
In 1951, Dantzig showed the equivalence of linear programming problems and ... This note concerns the equivalence between linear programming (LP) ...
W. B. Vasantha Kandasamy; Florentin Smarandache
2009-02-01T23:59:59.000Z
This book is a continuation of the book n-linear algebra of type I and its applications. Most of the properties that could not be derived or defined for n-linear algebra of type I is made possible in this new structure: n-linear algebra of type II which is introduced in this book. In case of n-linear algebra of type II we are in a position to define linear functionals which is one of the marked difference between the n-vector spaces of type I and II. However all the applications mentioned in n-linear algebras of type I can be appropriately extended to n-linear algebras of type II. Another use of n-linear algebra (n-vector spaces) of type II is that when this structure is used in coding theory we can have different types of codes built over different finite fields whereas this is not possible in the case of n-vector spaces of type I. Finally in the case of n-vector spaces of type II, we can obtain n-eigen values from distinct fields; hence, the n-characteristic polynomials formed in them are in distinct different fields. An attractive feature of this book is that the authors have suggested 120 problems for the reader to pursue in order to understand this new notion. This book has three chapters. In the first chapter the notion of n-vector spaces of type II are introduced. This chapter gives over 50 theorems. Chapter two introduces the notion of n-inner product vector spaces of type II, n-bilinear forms and n-linear functionals. The final chapter suggests over a hundred problems. It is important that the reader is well-versed not only with linear algebra but also n-linear algebra of type I.
Electric-Magnetic Duality and the Heavy Quark Potential
M. Baker
1996-09-05T23:59:59.000Z
We use the assumption of electric-magnetic duality to express the heavy quark potential in QCD in terms of a Wilson Loop $W_{eff}(\\Gamma)$ determined by the dynamics of a dual theory which is weakly coupled at long distances. The classical approximation gives the leading contribution to $W_{eff}(\\Gamma)$ and yields a velocity dependent heavy quark potential which for large $R$ becomes linear in $R$, and which for small $R$ approaches lowest order perturbative QCD. The corresponding long distance interaction between color magnetic monopoles is governed by a Yukawa potential. As a consequence the magnetic interaction between the color magnetic moments of the quarks is exponentially damped. The semi-classical corrections to $W_{eff}(\\Gamma)$ due to fluctuations of the classical flux tube should lead to an effective string theory free from the conformal anomaly.
The Stability of Magnetized Rotating Plasmas with Superthermal Fields
Pessah, M E
2004-01-01T23:59:59.000Z
During the last decade it has become evident that the magnetorotational instability is at the heart of the enhanced angular momentum transport in weakly magnetized accretion disks around neutron stars and black holes. In this paper, we investigate the local linear stability of differentially rotating, magnetized flows and the evolution of the magnetorotational instability beyond the weak-field limit. We show that, when superthermal toroidal fields are considered, both compressibility and magnetic tension terms, related to the curvature of toroidal field lines, should be taken fully into account. We demonstrate that, contrary to the results of most previous investigations, the presence of a toroidal component in the magnetic field plays a crucial role not only in the growth rates of the unstable modes but also in determining which modes are subject to instabilities. We find that, for rotationally supported configurations, the magnetorotational instability is stabilized at low wavenumbers for toroidal Alfven sp...
CLIQ. A new quench protection technology for superconducting magnets
Ravaioli, Emmanuele; ten Kate, H H J
CLIQ, the Coupling-Loss Induced Quench system, is a new method for protecting superconducting magnets after a sudden transition to the normal state. It offers significant advantages over the conventional technology due to its effective mechanism for heating the superconductor relying on coupling loss and its robust electrical design, which makes it more reliable and less interfering with the coil winding process. The analysis of the electro-magnetic and thermal transients during and after a CLIQ discharge allows identifying the system parameters that affect the system performance and defining guidelines for implementing this technology on coils of various characteristics. Most existing superconducting magnets can be protected by CLIQ as convincingly shown by test results performed on magnets of different sizes, superconductor types, geometries, cables and strand parameters. Experimental results are successfully reproduced by means of a novel technique for modeling non-linear dynamic effects in superconducting...
MAGNETIC HELICITY IN THE DISSIPATION RANGE OF STRONG IMBALANCED TURBULENCE
Markovskii, S. A.; Vasquez, Bernard J., E-mail: sergei.markovskii@unh.edu, E-mail: bernie.vasquez@unh.edu [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)
2013-05-01T23:59:59.000Z
Hybrid numerical simulations of freely decaying two-dimensional turbulence are presented. The background magnetic field is perpendicular to the simulation plane, which eliminates linear kinetic Alfven waves from the system. The net magnetic helicity of the initial fluctuations at large scales is zero. The turbulence is set to be imbalanced in the sense that the net cross-helicity is not zero. As the turbulence evolves, it develops nonzero magnetic helicity at smaller scales, in the proton kinetic range. In the quasi-steady state of evolution, the magnetic helicity spectrum has a peak consistent with the solar wind observations. The peak position depends on the plasma beta and correlates with a sharp decline of the cross-helicity spectrum.
X-Ray Diffraction Microscopy of Magnetic Structures
Turner, J.; Lima, E.; Huang, X.; Krupin, O.; Seu, K.; Parks, D.; Kevan, S.; Kisslinger, K.; McNulty, I.; Gambino, R.; Mangin, S.; Roy, S. and Fischer, P.
2011-07-14T23:59:59.000Z
We report the first proof-of-principle experiment of iterative phase retrieval from magnetic x-ray diffraction. By using the resonant x-ray excitation process and coherent x-ray scattering, we show that linearly polarized soft x rays can be used to image both the amplitude and the phase of magnetic domain structures. We recovered the magnetic structure of an amorphous terbium-cobalt thin film with a spatial resolution of about 75 nm at the Co L{sub 3} edge at 778 eV. In comparison with soft x-ray microscopy images recorded with Fresnel zone plate optics at better than 25 nm spatial resolution, we find qualitative agreement in the observed magnetic structure.
Hysteresis in Magnetic Shape Memory Composites: Modeling and Simulation
Conti, Sergio; Rumpf, Martin
2015-01-01T23:59:59.000Z
Magnetic shape memory alloys are characterized by the coupling between a structural phase transition and magnetic one. This permits to control the shape change via an external magnetic field, at least in single crystals. Composite materials with single-crystalline particles embedded in a softer matrix have been proposed as a way to overcome the blocking of the transformation at grain boundaries. We investigate hysteresis phenomena for small NiMnGa single crystals embedded in a polymer matrix for slowly varying magnetic fields. The evolution of the microstructure is studied within the rate-independent variational framework proposed by Mielke and Theil (1999). The underlying variational model incorporates linearized elasticity, micromagnetism, stray field and a dissipation term proportional to the volume swept by the phase boundary. The time discretization is based on an incremental minimization of the sum of energy and dissipation. A backtracking approach is employed to approximately ensure the global minimali...
Charge and magnetization inhomogeneities in diluted magnetic semiconductors
Timm, Carsten
2006-03-01T23:59:59.000Z
It is predicted that III-V diluted magnetic semiconductors can exhibit stripelike modulations of magnetization and carrier concentration. This inhomogeneity results from the strong dependence of the magnetization on the carrier concentration. Within...
ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE
Martinez Gonzalez, M. J. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Asensio Ramos, A. [Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain)
2012-08-20T23:59:59.000Z
The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.
Molten metal feed system controlled with a traveling magnetic field
Praeg, Walter F. (Palos Park, IL)
1991-01-01T23:59:59.000Z
A continuous metal casting system in which the feed of molten metal is controlled by means of a linear induction motor capable of producing a magnetic traveling wave in a duct that connects a reservoir of molten metal to a caster. The linear induction motor produces a traveling magnetic wave in the duct in opposition to the pressure exerted by the head of molten metal in the reservoir so that p.sub.c =p.sub.g -p.sub.m where p.sub.c is the desired pressure in the caster, p.sub.g is the gravitational pressure in the duct exerted by the force of the head of molten metal in the reservoir, and p.sub.m is the electromagnetic pressure exerted by the force of the magnetic field traveling wave produced by the linear induction motor. The invention also includes feedback loops to the linear induction motor to control the casting pressure in response to measured characteristics of the metal being cast.
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2011; 18:961980
De Sterck, Hans
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2011; 18:961980 Published aggregation method of [1], and the Markov chain algebraic multigrid (MCAMG) method of [3] using the OTF
Linear Algebra Notes David A. SANTOS
California at Santa Cruz, University of
Linear Algebra Notes David A. SANTOS dsantos@ccp.edu January 2, 2010 REVISION #12;ii Contents . . . . . . . . . . . . . . . . . . 15 2 Matrices and Matrix Operations 18 2.1 The Algebra of Matrices . . . . . . . . . . . 18 2.3 Diagonalisability . . . . . . . . . . . . . . 143 7.4 Theorem of Cayley and Hamilton . . . . . 147 8 Linear Algebra
Blood Management Using Approximate Linear Programming
Shenoy, Prashant
Blood Management Using Approximate Linear Programming Marek Petrik and Shlomo Zilberstein January 13th, 2009 Marek Petrik and Shlomo Zilberstein () Blood Management Using Approximate Linear ProgrammingJanuary 13th, 2009 1 / 36 #12;Blood Inventory Management Problem Regional blood banks: Aggregate
Best Linear Unbiased Estimate Motivation for BLUE
Fowler, Mark
1 Chapter 6 Best Linear Unbiased Estimate (BLUE) #12;2 Motivation for BLUE Except for Linear Model to a sub-optimal estimate BLUE is one such sub-optimal estimate Idea for BLUE: 1. Restrict estimate) Advantage of BLUE:Needs only 1st and 2nd moments of PDF Mean & Covariance Disadvantages of BLUE: 1. Sub
Thvenin's Theorem Linear two-terminal circuit
Kozick, Richard J.
Thévenin's Theorem Linear two-terminal circuit can be replaced by an equivalent circuit composed at terminals with allResistance at terminals with all independent circuit sources set to zero #12;Norton's Theorem Linear two-terminal circuit can be replaced by an equivalentbe replaced by an equivalent circuit
Soft materials for linear electromechanical energy conversion
Antal Jakli; Nandor Eber
2014-07-29T23:59:59.000Z
We briefly review the literature of linear electromechanical effects of soft materials, especially in synthetic and biological polymers and liquid crystals (LCs). First we describe results on direct and converse piezoelectricity, and then we discuss a linear coupling between bending and electric polarization, which maybe called bending piezoelectricity, or flexoelectricity.
Non-linear transformer modeling and simulation
Archer, W.E.; Deveney, M.F.; Nagel, R.L.
1994-08-01T23:59:59.000Z
Transformers models for simulation with Pspice and Analogy`s Saber are being developed using experimental B-H Loop and network analyzer measurements. The models are evaluated for accuracy and convergence using several test circuits. Results are presented which demonstrate the effects on circuit performance from magnetic core losses eddy currents and mechanical stress on the magnetic cores.
Drozhdin, A.I.; Kashikhin, V.V.; Kashikhin, V.S.; Lopes, M.L.; Mokhov, N.V.; Zlobin, A.V.; /Fermilab; Seryi, Andrei; /SLAC
2011-10-14T23:59:59.000Z
Radiation heat deposition in the superconducting magnets of the Interaction Region (IR) of a linear collider can be a serious issue that limits the magnet operating margins and shortens the material lifetime. Radiation and thermal analyses of the IR quadrupoles in the incoming and extraction beam lines of the ILC are performed in order to determine the magnet limits. This paper presents an analysis of the radial, azimuthal and longitudinal distributions of heat deposition in the incoming and disrupted beam doublets. Operation margins of the magnets based on NbTi superconductor are calculated and compared. The radiation and thermal analysis of the ILC IR quadrupoles based on Rutherford type cables was performed. It was found that the peak radiation heat deposition takes place in the second extraction quadrupole QFEX2. The maximum power density in the coil is {approx}17mW/g. This is rather high, comparing to the proton machines (LHC). However, the fast radial decay of the heat deposition together with the high thermal conductivity of the Rutherford type cable limits the coil temperatures to a moderate level. It was determined that both 2-layer and 4-layer QFEX2 magnet designs have thermal margins of a factor of {approx}4 at the nominal gradient of 31.3 T/m. Because of the large margins, these magnets can easily accommodate possible changes in the IR optics and heat deposition levels.
Neal, R B
1956-01-01T23:59:59.000Z
The Stanford Mark III linear accelerator and speculations concerning the multi-Bev applications of electron linear accelerators
High Temperature, Permanent Magnet Biased Magnetic Bearings
Gandhi, Varun R.
2010-07-14T23:59:59.000Z
, then the molding process was carried out to form the potting cement on the each stator. After this the stators are baked in the oven and once ready the magnets and back-irons are put onto the stator. Shown below in Figure 3-11 is an assembly tool designed... rings. The bearing and its support rings were then carried onto the test rig and mounted at one end of the table. Throughout the assembly process a lot of care had to be taken so as to avoid damaging of the permanent magnets, stator and its coils...
Assumptions that imply quantum dynamics is linear
Thomas F. Jordan
2006-01-26T23:59:59.000Z
A basic linearity of quantum dynamics, that density matrices are mapped linearly to density matrices, is proved very simply for a system that does not interact with anything else. It is assumed that at each time the physical quantities and states are described by the usual linear structures of quantum mechanics. Beyond that, the proof assumes only that the dynamics does not depend on anything outside the system but must allow the system to be described as part of a larger system. The basic linearity is linked with previously established results to complete a simple derivation of the linear Schrodinger equation. For this it is assumed that density matrices are mapped one-to-one onto density matrices. An alternative is to assume that pure states are mapped one-to-one onto pure states and that entropy does not decrease.
Passive magnetic bearing configurations
Post, Richard F. (Walnut Creek, CA)
2011-01-25T23:59:59.000Z
A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.
Superconducting Magnet Division
Ohta, Shigemi
Superconducting Magnet Division MAGNETIC DESIGN OF E-LENS SOLENOID AND CORRECTOR SYSTEM FOR RHIC* R.6 A gun collectors gun Combined Horizontal and Vertical Corrector Design Both types of dipole correctors. Gupta, M. Anerella, W. Fischer, G. Ganetis, X. Gu, A. Ghosh, A. Jain, P. Kovach, A. Marone, S. Plate, A
Perez Rojas, H.; Rodriguez Querts, E. [Instituto de Cibernetica, Matematica y Fisica, Calle E No. 309, esq. a 15 Vedado, C. Havana (Cuba)
2006-06-19T23:59:59.000Z
We study vacuum properties in a strong magnetic field as the zero temperature and zero density limit of quantum statistics. For charged vector bosons (W bosons) the vacuum energy density diverges for B > B{sub c} = m{sub w}{sup 2}/e, leading to vacuum instability. A logarithmic divergence of vacuum magnetization is found for B = Bc, which suggests that if the magnetic field is large enough, it is self-consistently maintained, and this mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the instability of the ground state for B > B{sub c}{sup '} = m{sub n}{sup 2}/q also leads to the vacuum energy density divergence for fields B > B{sub c}{sup '} and to the magnetization divergence for B B{sub c}{sup '}. The possibility of virtual electron-positron pairs bosonization in strong magnetic field and the applicability of the neutral bosons model to describe the virtual positronium behavior in a magnetic field are discussed. We conjecture that this could lead to vacuum self-magnetization in QED.
Linear Transformations In this Chapter, we will define the notion of a linear transformation between
Carrell, Jim
Chapter 6 Linear Transformations In this Chapter, we will define the notion of a linear transformation between two vector spaces V and W which are defined over the same field and prove the most basic transformations is equivalent to matrix theory. We will also study the geometric properties of linear
Tsai, Cheng-Ying; Li, Rui; Tennant, Chris
2015-01-01T23:59:59.000Z
As is known, microbunching instability (MBI) has been one of the most challenging issues in designs of magnetic chicanes for short-wavelength free-electron lasers or linear colliders, as well as those of transport lines for recirculating or energy recovery linac machines. To more accurately quantify MBI in a single-pass system and for more complete analyses, we further extend and continue to increase the capabilities of our previously developed linear Vlasov solver [1] to incorporate more relevant impedance models into the code, including transient and steady-state free-space and/or shielding coherent synchrotron radiation (CSR) impedances, the longitudinal space charge (LSC) impedances, and the linac geometric impedances with extension of the existing formulation to include beam acceleration [2]. Then, we directly solve the linearized Vlasov equation numerically for microbunching gain amplification factor. In this study we apply this code to a beamline lattice of transport arc [3] following an upstream linac...
Khater, A.H.; Moawad, S.M.; Callebaut, D.K. [Department of Mathematics, Faculty of Science, Cairo University, Beni-Suef (Egypt); Departement Natuurkunde, Campus Drie Eiken, Universiteit Antwerpen - UA, B-2610 Antwerpen (Belgium)
2005-01-01T23:59:59.000Z
The equilibrium and Lyapunov stability properties for two-dimensional ideal magnetohydrodynamic (MHD) plasmas with incompressible and homogeneous (i.e., constant density) flows are investigated. In the unperturbed steady state, both the velocity and magnetic field are nonzero and have three components in a Cartesian coordinate system with translational symmetry (i.e., one ignorable spatial coordinate). It is proved that (a) the solutions of the ideal MHD steady state equations with incompressible and homogeneous flows in the plane are also valid for equilibria with the axial velocity component being a free flux function and the axial magnetic field component being a constant (b) the conditions of linearized Lyapunov stability for these MHD flows in the planar case (in which the fields have only two components) are also valid for symmetric equilibria that have a nonplanar velocity field component as well as a nonplanar magnetic field component. On using the method of convexity estimates, nonlinear stability conditions are established.
Active Magnetic Regenerator Experimental Optimization
Victoria, University of
the potential to create more efficient and compact refrigeration devices is an Active Magnetic Regenerative temperature refrigerators, as well as efficient gas liquefaction plants (AMRLs). Active Magnetic Regenerator Refrigeration exploits the magnetocaloric effect displayed by magnetic materials whereby a reversible
Kissock, J. K.; Haberl, J. S.; Claridge, D. E.
2002-11-01T23:59:59.000Z
This report summarizes the results of ASHRAE Research Project 1050: Development of a Toolkit for Calculating Linear, Change-Point Linear and Multiple Linear Inverse Building Energy Analysis Models. The Inverse Modeling Toolkit (WIT) is a FORTRAN 90...
Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State
S. Regnier; E. R. Priest
2008-05-12T23:59:59.000Z
To understand the physics of solar flares, including the local reorganisation of the magnetic field and the acceleration of energetic particles, we have first to estimate the free magnetic energy available for such phenomena, which can be converted into kinetic and thermal energy. The free magnetic energy is the excess energy of a magnetic configuration compared to the minimum-energy state, which is a linear force-free field if the magnetic helicity of the configuration is conserved. We investigate the values of the free magnetic energy estimated from either the excess energy in extrapolated fields or the magnetic virial theorem. For four different active regions, we have reconstructed the nonlinear force-free field and the linear force-free field corresponding to the minimum-energy state. The free magnetic energies are then computed. From the energy budget and the observed magnetic activity in the active region, we conclude that the free energy above the minimum-energy state gives a better estimate and more insights into the flare process than the free energy above the potential field state.
Journal of Magnetism and Magnetic Materials ] (
Schumann, Rolf
width of internal field fluctuations. For the ``normal'' TR of the metallic magnets SmCo5; Sm2Co17 of the parameters for SmCo5 and barium ferrite. Susceptibility measurements with small alternating fields, carried out at different points of the TR curve, as well as repeating TR-experiments at SmCo5 demonstrate
Review and comparison of magnet designs for magnetic refrigeration
Bjørk, R; Smith, A; Pryds, N
2014-01-01T23:59:59.000Z
One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, $\\Lambda_\\mathrm{cool}$. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis of the reviewed designs.
Determining the minimum mass and cost of a magnetic refrigerator
Bjørk, R; Bahl, C R H; Pryds, N
2014-01-01T23:59:59.000Z
An expression is determined for the mass of the magnet and magnetocaloric material needed for a magnetic refrigerator and these are determined using numerical modeling for both parallel plate and packed sphere bed regenerators as function of temperature span and cooling power. As magnetocaloric material Gd or a model material with a constant adiabatic temperature change, representing a infinitely linearly graded refrigeration device, is used. For the magnet a maximum figure of merit magnet or a Halbach cylinder is used. For a cost of \\$40 and \\$20 per kg for the magnet and magnetocaloric material, respectively, the cheapest 100 W parallel plate refrigerator with a temperature span of 20 K using Gd and a Halbach magnet has 0.8 kg of magnet, 0.3 kg of Gd and a cost of \\$35. Using the constant material reduces this cost to \\$25. A packed sphere bed refrigerator with the constant material costs \\$7. It is also shown that increasing the operation frequency reduces the cost. Finally, the lowest cost is also found a...
Electromagnetic acceleration of permanent magnets
Dolya, S N
2015-01-01T23:59:59.000Z
We consider the acceleration of the permanent magnets, consisting of neodymium iron boron by means of the running magnetic field gradient. It is shown that the specific magnetic moment per nucleon in neodymium iron boron is determined by the remained magnetization of the substance. The maximum accessable gradient of the magnetic field accelerating the permanent magnets is determined by the coercive force thirty kilogauss. For the neodymium iron boron magnets this gradient is equal to twenty kilogauss divided by one centimeter. The finite velocity of the magnets six kilometers per second, the length of acceleration is six hundred thirty-seven meters.
QUENCHES IN LARGE SUPERCONDUCTING MAGNETS
Eberhard, P.H.
2010-01-01T23:59:59.000Z
QUENCHES IN LARGE SUPERCONDUCTING MAGNETS. P. H. Eberhard,Study of an Unprotected Superconducting Coil Going Normal,"Method for Testing Superconducting Magnets," LBL Physics
Large Magnetization at Carbon Surfaces
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...
Condensed Matter and Magnet Science
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
power and diagnostics (HV and HC) Suite of nondestructive pulsed magnets up to 100 tesla Thermoacoustics and fluid dynamics Transport, magnetism, and thermodynamic...
LED Linear Lamps and Troffer Lighting
Broader source: Energy.gov [DOE]
The CALiPER program performed a series of investigations on linear LED lamps. Each report in the series covers the performance of up to 31 linear LED lamps, which were purchased in late 2012 or 2013. The first report focuses on bare lamp performance of LED T8 replacement lamps and subsequent reports examine performance in various troffers, as well as cost-effectiveness. There is also a concise guidance document that describes the findings of the Series 21 studies and provides practical advice to manufacturers, specifiers, and consumers (Report 21.4: Summary of Linear (T8) LED Lamp Testing , 5 pages, June 2014).
Optically isolated signal coupler with linear response
Kronberg, James W. (Aiken, SC)
1994-01-01T23:59:59.000Z
An optocoupler for isolating electrical signals that translates an electrical input signal linearly to an electrical output signal. The optocoupler comprises a light emitter, a light receiver, and a light transmitting medium. The light emitter, preferably a blue, silicon carbide LED, is of the type that provides linear, electro-optical conversion of electrical signals within a narrow wavelength range. Correspondingly, the light receiver, which converts light signals to electrical signals and is preferably a cadmium sulfide photoconductor, is linearly responsive to light signals within substantially the same wavelength range as the blue LED.
Tower systems for Linearly repetitive Delone sets
José Aliste-Prieto; Daniel Coronel
2010-03-22T23:59:59.000Z
In this paper we study linearly repetitive Delone sets and prove, following the work of Bellissard, Benedetti and Gambaudo, that the hull of a linearly repetitive Delone set admits a properly nested sequence of box decompositions (tower system) with strictly positive and uniformly bounded (in size and norm) transition matrices. This generalizes a result of Durand for linearly recurrent symbolic systems. Furthermore, we apply this result to give a new proof of a classic estimation of Lagarias and Pleasants on the rate of convergence of patch-frequencies.
Computing nonlinear force free coronal magnetic fields
T. Wiegelmann; T. Neukirch
2008-01-21T23:59:59.000Z
Knowledge of the structure of the coronal magnetic field is important for our understanding of many solar activity phenomena, e.g. flares and CMEs. However, the direct measurement of coronal magnetic fields is not possible with present methods, and therefore the coronal field has to be extrapolated from photospheric measurements. Due to the low plasma beta the coronal magnetic field can usually be assumed to be approximately force free, with electric currents flowing along the magnetic field lines. There are both observational and theoretical reasons which suggest that at least prior to an eruption the coronal magnetic field is in a nonlinear force free state. Unfortunately the computation of nonlinear force free fields is way more difficult than potential or linear force free fields and analytic solutions are not generally available. We discuss several methods which have been proposed to compute nonlinear force free fields and focus particularly on an optimization method which has been suggested recently. We compare the numerical performance of a newly developed numerical code based on the optimization method with the performance of another code based on an MHD relaxation method if both codes are applied to the reconstruction of a semi-analytic nonlinear force-free solution. The optimization method has also been tested for cases where we add random noise to the perfect boundary conditions of the analytic solution, in this way mimicking the more realistic case where the boundary conditions are given by vector magnetogram data. We find that the convergence properties of the optimization method are affected by adding noise to the boundary data and we discuss possibilities to overcome this difficulty.
Jeremy S. Heyl; Lars Hernquist
1996-08-25T23:59:59.000Z
We calculate the reaction cross-sections for the fusion of hydrogen and deuterium in strong magnetic fields as are believed to exist in the atmospheres of neutron stars. We find that in the presence of a strong magnetic field ($B \\gsim 10^{12}$G), the reaction rates are many orders of magnitude higher than in the unmagnetized case. The fusion of both protons and deuterons are important over a neutron star's lifetime for ultrastrong magnetic fields ($B \\sim 10^{16}$G). The enhancement may have dramatic effects on thermonuclear runaways and bursts on the surfaces of neutron stars.
Bonanos, Peter (East Brunswick, NJ)
1983-01-01T23:59:59.000Z
A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.
Permanent magnet energy conversion machine with magnet mounting arrangement
Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN)
1999-01-01T23:59:59.000Z
A hybrid permanent magnet dc motor includes three sets of permanent magnets supported by the rotor and three sets of corresponding stators fastened to the surrounding frame. One set of magnets operates across a radial gap with a surrounding radial gap stator, and the other two sets of magnets operate off the respective ends of the rotor across respective axial gaps.
Magnetic Resonance Imaging System Based on Earth's Magnetic Field
Stepi?nik, Janez
Magnetic Resonance Imaging System Based on Earth's Magnetic Field Ales Mohoric,1,* Gorazd Planinsic magnetic field can be partly compensated by the receiving coil design and shielding of electromagnetic pick and must be monitored accurately.[8 10] The importance of NMR in a non-uniform magnetic field
GROUP SPARSITY VIA LINEAR-TIME PROJECTION
2008-08-01T23:59:59.000Z
Jul 31, 2008 ... linear regression model subject to a bound on the l1-norm of the coefficients; .... this strategy scales poorly with the number of non-zero groups.
TIGHTER LINEAR AND SEMIDEFINITE RELAXATIONS FOR MAX ...
7 by a detailed analysis of the new relaxations. If positive ... Key words. linear relaxation, semide nite relaxation, lift and project, cut polytope, stable set. polytope ..... su ces to consider the circuit inequalities for chordless circuits [7]. Therefore ...
Photon emission within the linear sigma model
F. Wunderlich; B. Kampfer
2014-12-22T23:59:59.000Z
Soft-photon emission rates are calculated within the linear sigma model. The investigation is aimed at answering the question to which extent the emissivities map out the phase structure of this particular effective model of strongly interacting matter.
Linear Thermodynamics of Rodlike DNA Filtration
Li, Zirui
Linear thermodynamics transportation theory is employed to study filtration of rodlike DNA molecules. Using the repeated nanoarray consisting of alternate deep and shallow regions, it is demonstrated that the complex ...
Anisotropy of magnetic emulsions induced by magnetic and electric fields
Yury I. Dikansky; Alexander N. Tyatyushkin; Arthur R. Zakinyan
2011-09-10T23:59:59.000Z
The anisotropy of magnetic emulsions induced by simultaneously acting electric and magnetic fields is theoretically and experimentally investigated. Due to the anisotropy, the electric conductivity and magnetic permeability of a magnetic emulsion are no longer scalar coefficients, but are tensors. The electric conductivity and magnetic permeability tensors of sufficiently diluted emulsions in sufficiently weak electric and magnetic fields are found as functions of the electric and magnetic intensity vectors. The theoretically predicted induced anisotropy was verified experimentally. The experimental data are analyzed and compared with theoretical predictions. The results of the analysis and comparison are discussed.
Magnetization reversal assisted by half antivortex states in nanostructured circular cobalt disks
Lara, A.; Aliev, F. G., E-mail: farkhad.aliev@uam.es [Dpto. Física de la Materia Condensada, Instituto Nicolas Cabrera (INC) and Condensed Matter Physics Institute (IFIMAC), Universidad Autónoma de Madrid, Madrid (Spain); Dobrovolskiy, O. V. [Physikalisches Institut, Goethe University, Frankfurt am Main (Germany); Physics Department, V. Karazin National University, Kharkiv (Ukraine); Prieto, J. L. [Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), Universidad Politecnica de Madrid (Spain); Huth, M. [Physikalisches Institut, Goethe University, Frankfurt am Main (Germany)
2014-11-03T23:59:59.000Z
The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play a crucial role in spin torque induced vortex core reversal in circular disks. Here, we report on magnetization reversal in circular disks with nanoholes through consecutive metastable states with half antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) disks with two and three linearly arranged nanoholes directed at 45° and 135° with respect to the external magnetic field show reproducible step-like changes in the anisotropic magnetoresistance and magnetic permeability due to transitions between different intermediate states mediated by vortices and half antivortices confined to the dot nanoholes and edges, respectively. Our findings are relevant for the development of multi-hole based spintronic and magnetic memory devices.
QPOs: Einstein's gravity non-linear resonances
Paola Rebusco; Marek A. Abramowicz
2006-01-30T23:59:59.000Z
There is strong evidence that the observed kHz Quasi Periodic Oscillations (QPOs) in the X-ray flux of neutron star and black hole sources in LMXRBs are linked to Einstein's General Relativity. Abramowicz&Klu\\'zniak (2001) suggested a non-linear resonance model to explain the QPOs origin: here we summarize their idea and the development of a mathematical toy-model which begins to throw light on the nature of Einstein's gravity non-linear oscillations.
Photon Linear Collider Gamma-Gamma Summary
Gronberg, J
2012-02-27T23:59:59.000Z
High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.
Lectures on Numerical Linear Algebra Yunkai Zhou
Zhou, Yunkai
University Dallas, Texas 75075 yzhou@smu.edu Spring, 2013 #12;Acknowledgements The lecture slides benefit. Y. Zhou Math-6316/CS-7366, SMU 2/210 #12;Basic Linear Algebra Spaces: Rn , Cn , Rn×n , Cn×n , Rm. Zhou Math-6316/CS-7366, SMU 3/210 #12;Basic Linear Algebra Spaces: Rn , Cn , Rn×n , Cn×n , Rm×n , Cm
Lectures on Numerical Linear Algebra Yunkai Zhou
Zhou, Yunkai
University Dallas, Texas 75075 yzhou@smu.edu Spring, 2012 #12;Acknowledgements The lecture slides benefit. Y. Zhou Math-6316/CS-7366, SMU 2/213 #12;Basic Linear Algebra Spaces: Rn , Cn , Rn×n , Cn×n , Rm. Zhou Math-6316/CS-7366, SMU 3/213 #12;Basic Linear Algebra Spaces: Rn , Cn , Rn×n , Cn×n , Rm×n , Cm
Non-linearities in the quantum multiverse
Orfeu Bertolami; Victor Herdeiro
2012-08-01T23:59:59.000Z
It has been recently proposed that the multiverse of eternal inflation and the many-worlds interpretation of quantum mechanics can be identified, yielding a new view on the measure and measurement problems. In the present note, we argue that a non-linear evolution of observables in the quantum multiverse would be an obstacle for such a description and that these non-linearities are expected from quite general arguments.
Interface and magnetic characterization of ultrathin EuO films with XMCD
Negusse, E.
2009-01-01T23:59:59.000Z
dichroism (XMCD) at the europium M 5 and copper L 3 edges.the available oxides of europium by comparing the measuredtwo common oxides of europium used to identify the relative
Lectures on Linear Algebra over Division Ring
Aleks Kleyn
2014-10-11T23:59:59.000Z
In this book i treat linear algebra over division ring. A system of linear equations over a division ring has properties similar to properties of a system of linear equations over a field. However, noncommutativity of a product creates a new picture. Matrices allow two products linked by transpose. Biring is algebra which defines on the set two correlated structures of the ring. As in the commutative case, solutions of a system of linear equations build up right or left vector space depending on type of system. We study vector spaces together with the system of linear equations because their properties have a close relationship. As in a commutative case, the group of automorphisms of a vector space has a single transitive representation on a frame manifold. This gives us an opportunity to introduce passive and active representations. Studying a vector space over a division ring uncovers new details in the relationship between passive and active transformations, makes this picture clearer. Considering of twin representations of division ring in Abelian group leads to the concept of D vector space and their linear map. Based on polyadditive map I considered definition of tensor product of rings and tensor product of D vector spaces.
A New Algorithm for Linear Programming
Dhananjay P. Mehendale
2015-03-28T23:59:59.000Z
In this paper we propose two types of new algorithms for linear programming. The first type of these new algorithms uses algebraic methods while the second type of these new algorithms uses geometric methods. The first type of algorithms is based on treating the objective function as a parameter. In this method, we form a matrix using coefficients in the system of equations consisting objective equation and equations obtained from inequalities defining constraint by introducing slack/surplus variables. We obtain reduced row echelon form for this matrix containing only one variable, namely, the objective function itself as an unknown parameter. We analyse this matrix in the reduced row echelon form and develop a clear cut method to find the optimal solution for the problem at hand, if and when it exists. We see that the entire optimization process can be developed through the proper analysis of the said matrix in the reduced row echelon form. The second type of algorithms that we propose for linear programming are inspired by geometrical considerations. All these algorithms pursue common aim of approaching closer and closer to centroid or some centrally located interior point for speeding up the process of reaching an optimal solution! We then proceed to show that the algebraic method developed above for linear programming naturally extends to non-linear and integer programming problems. For non-linear and integer programming problems we use the technique of Grobner bases and the methods of solving linear Diophantine equations respectively.
Magnetic Catalysis in Graphene
Christopher Winterowd; Carleton DeTar; Savvas Zafeiropoulos
2015-09-22T23:59:59.000Z
One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.
Modular tokamak magnetic system
Yang, Tien-Fang (Wayland, MA)
1988-01-01T23:59:59.000Z
A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.
Meyer, Ross E. (Los Alamos, NM)
1993-01-01T23:59:59.000Z
A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.
Meyer, R.E.
1993-03-09T23:59:59.000Z
A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.
Makarov, Sergey V; Krasnok, Alexander E; Belov, Pavel A
2015-01-01T23:59:59.000Z
We propose a novel concept for efficient dynamic tuning of optical properties of a high refractive index subwavelength nanoparticle with a magnetic Mie-type resonance by means of femtosecond laser radiation. This concept is based on ultrafast generation of electron-hole plasma within such nanoparticle, drastically changing its transient dielectric permittivity. This allows to manipulate by both electric and magnetic nanoparticle responses, resulting in dramatic changes of its extinction cross section and scattering diagram. Specifically, we demonstrate the effect of ultrafast switching-on a Huygens source in the vicinity of the magnetic dipole resonance. This approach enables to design ultrafast and compact optical switchers and modulators based on the "ultrafast magnetic light" concept.
Magnetic Catalysis in Graphene
Winterowd, Christopher; Zafeiropoulos, Savvas
2015-01-01T23:59:59.000Z
One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.
Geometrically frustrated quantum magnets
NikoliÄ‡ , Predrag, 1974-
2004-01-01T23:59:59.000Z
(cont.) more general lessons on frustrated quantum magnetism. At the end, we demonstrate some new mathematical tools on two other frustrated two-dimensional systems, and summarize our conclusions, with an outlook to remaining ...
Piecewise Linear Instrumental Variable Estimation of Causal Influence Richard Scheines
Spirtes, Peter
studies show that when the causal influence of X on Y is non-linear, the piecewise linear linear IV-estimator. In the final section, we describe an experiment comparing regular regression, linearPiecewise Linear Instrumental Variable Estimation of Causal Influence Richard Scheines Dept
Nance, Thomas A. (Aiken, SC)
2009-08-18T23:59:59.000Z
A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.
Berman, S.M.; Richardson R.W.
1983-12-29T23:59:59.000Z
The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.
Savici, Andrei T [ORNL; Granroth, Garrett E [ORNL; Broholm, Collin L [ORNL; Bird, Mark D [ORNL; Lee, Young S [ORNL
2010-01-01T23:59:59.000Z
ZEEMANS, a new instrument proposed for the Spallation Neutron Source (SNS) at Oak Ridge, will provide highest available magnetic elds for neutron scattering experiments. The unique capabilities of the magnet, large size and required connection to utilities demand a versatile instrument, able of performing diraction (powder and single crystal), SANS, re ectometry, and inelastic spectrometry, with minimal modications between congurations. In this paper we present preliminary design features for ZEEMANS. Monte Carlo simulations and analytical calculations were used to study its expected performance.
Freely oriented portable superconducting magnet
Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)
2010-01-12T23:59:59.000Z
A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.
On the Electrical and Magnetic Properties of some Indian Spices
Samson. K. Baby; T. E. Girish
2010-12-11T23:59:59.000Z
We have made experimental measurements of electrical conductivity, pH and relative magnetic susceptibility of the aqueous solutions of 24 indian spices. The measured values of electrical conductance of these spices are found to be linearly related to their ash content and bulk calorific values reported in literature. The physiological relevance of the pH and diamagnetic susceptibility of spices when consumed as food or medicine will be also discussed.
A multichannel magnetic probe system for analysing magnetic fluctuations in helical axis plasmas
Haskey, S. R.; Blackwell, B. D.; Seiwald, B.; Hole, M. J.; Pretty, D. G.; Howard, J.; Wach, J. [Plasma Research Laboratory, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)] [Plasma Research Laboratory, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)
2013-09-15T23:59:59.000Z
The need to understand the structure of magnetic fluctuations in H-1NF heliac [S. Hamberger et al., Fusion Technol. 17, 123 (1990)] plasmas has motivated the installation of a sixteen former, tri-axis helical magnetic probe Mirnov array (HMA). The new array complements two existing poloidal Mirnov arrays by providing polarisation information, higher frequency response, and improved toroidal resolution. The helical placement is ideal for helical axis plasmas because it positions the array as close as possible to the plasma in regions of varying degrees of favourable curvature in the magnetohydrodynamic sense, but almost constant magnetic angle. This makes phase variation with probe position near linear, greatly simplifying the analysis of the data. Several of the issues involved in the design, installation, data analysis, and calibration of this unique array are presented including probe coil design, frequency response measurements, mode number identification, orientation calculations, and mapping probe coil positions to magnetic coordinates. Details of specially designed digitally programmable pre-amplifiers, which allow gains and filters to be changed as part of the data acquisition initialisation sequence and stored with the probe signals, are also presented. The low shear heliac geometry [R. Jiménez-Gómez et al., Nucl. Fusion 51, 033001 (2011)], flexibility of the H-1NF heliac, and wealth of information provided by the HMA create a unique opportunity for detailed study of Alfvén eigenmodes, which could be a serious issue for future fusion reactors.
Constraining primordial magnetic fields with future cosmic shear surveys
Fedeli, C. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Moscardini, L., E-mail: cosimo.fedeli@astro.ufl.edu, E-mail: lauro.moscardini@unibo.it [Dipartimento di Astronomia, Università di Bologna, Via Ranzani 1, 40127 Bologna (Italy)
2012-11-01T23:59:59.000Z
The origin of astrophysical magnetic fields observed in galaxies and clusters of galaxies is still unclear. One possibility is that primordial magnetic fields generated in the early Universe provide seeds that grow through compression and turbulence during structure formation. A cosmological magnetic field present prior to recombination would produce substantial matter clustering at intermediate/small scales, on top of the standard inflationary power spectrum. In this work we study the effect of this alteration on one particular cosmological observable, cosmic shear. We adopt the semi-analytic halo model in order to describe the non-linear clustering of matter, and feed it with the altered mass variance induced by primordial magnetic fields. We find that the convergence power spectrum is, as expected, substantially enhanced at intermediate/small angular scales, with the exact amplitude of the enhancement depending on the magnitude and power-law index of the magnetic field power spectrum. Specifically, for a fixed amplitude, the effect of magnetic fields is larger for larger spectral indices. We use the predicted statistical errors for a future wide-field cosmic shear survey, on the model of the ESA Cosmic Vision mission Euclid, in order to forecast constraints on the amplitude of primordial magnetic fields as a function of the spectral index. We find that the amplitude will be constrained at the level of ? 0.1 nG for n{sub B} ? ?3, and at the level of ? 10{sup ?7} nG for n{sub B} ? 3. The latter is at the same level of lower bounds coming from the secondary emission of gamma-ray sources, implying that for high spectral indices Euclid will certainly be able to detect primordial magnetic fields, if they exist. The present study shows how large-scale structure surveys can be used for both understanding the origins of astrophysical magnetic fields and shedding new light on the physics of the pre-recombination Universe.
Telescoping magnetic ball bar test gage
Bryan, J.B.
1982-03-15T23:59:59.000Z
A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengagable servo drives which cannot be clutched out. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine.
SYNOPTIC MAPPING OF CHROMOSPHERIC MAGNETIC FLUX
Jin, C. L. [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Harvey, J. W.; Pietarila, A., E-mail: cljin@nao.cas.cn, E-mail: jharvey@nso.edu, E-mail: apietarila@nso.edu [National Solar Observatory, Tucson, AZ 85719 (United States)
2013-03-10T23:59:59.000Z
We used daily full-disk Ca II 854.2 nm magnetograms from the Synoptic Optical Long Term Investigations of the Sun (SOLIS) facility to study the chromospheric magnetic field from 2006 April through 2009 November. We determined and corrected previously unidentified zero offsets in the SOLIS magnetograms. By tracking the disk passages of stable unipolar regions, the measured net flux densities were found to systematically decrease from the disk center to the limb by a factor of about two. This decrease was modeled using a thin flux tube model with a difference in signal formation height between the center and limb sides. Comparison of photospheric and chromospheric observations shows that their differences are largely due to horizontal spreading of magnetic flux with increasing height. The north polar magnetic field decreased nearly linearly with time during our study period while the south polar field was nearly constant. We used the annual change in the viewing angle of the polar regions to estimate the radial and meridional components of the polar fields and found that the south polar fields were tilted away from the pole. Synoptic maps of the chromospheric radial flux density distribution were used as boundary conditions for extrapolation of the field from the chromosphere into the corona. A comparison of modeled and observed coronal hole boundaries and coronal streamer positions showed better agreement when using the chromospheric rather than the photospheric synoptic maps.
Magnetic moments of vector, axial, and tensor mesons in lattice QCD
Lee, F X; Wilcox, W
2008-01-01T23:59:59.000Z
We present a calculation of magnetic moments for selected spin-1 mesons using the techniques of lattice QCD. This is carried out by introducing progressively small static magnetic field on the lattice and measuring the linear response of a hadron's mass shift. The calculations are done on $24^4$ quenched lattices using standard Wilson actions, with $\\beta$=6.0 and pion mass down to 500 MeV. The results are compared to those from the form factor method where available.
Modification of {Delta}{sup Prime} by magnetic feedback and kinetic effects
Liu Yueqiang; Hastie, R. J.; Hender, T. C. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)
2012-09-15T23:59:59.000Z
Two possible ways of modifying the linear tearing mode index, by active magnetic feedback and by drift kinetic effects of deeply trapped particles, are analytically investigated. Magnetic feedback schemes, studied in this work, are found generally stabilizing for {Delta}{sup Prime }. The drift kinetic effects from both thermal particles and hot ions tend to reduce the power of the large solution from the outer region. This generally leads to a destabilization of {Delta} Prime for the toroidal analytic equilibria considered here.
Deconfinement to quark matter in neutron stars - The influence of strong magnetic fields
Dexheimer, V. [UFSC, Florianopolis, Brazil and Gettysburg College, Gettysburg, PA (Brazil); Negreiros, R. [UFF, Niteroi (Brazil) and FIAS - Johann Wolfgang Goethe University, Frankfurt (Germany); Schramm, S. [FIAS - Johann Wolfgang Goethe University, Frankfurt (Germany); Hempel, M. [University of Basel, Basel (Switzerland)
2013-03-25T23:59:59.000Z
We use an extended version of the hadronic SU(3) non-linear realization of the sigma model that also includes quarks to study hybrid stars. Within this approach, the degrees of freedom change naturally as the temperature/density increases. Different prescriptions of charge neutrality, local and global, are tested and the influence of strong magnetic fields and the anomalous magnetic moment on the particle population is discussed.
AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER
AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER DAMPING RINGS Urban ALL RIGHTS RESERVED #12;AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR Linear Collider (ILC) damping rings. Results from optimizations of the parameters of this wiggler
AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER
AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER DAMPING RINGS Urban ALL RIGHTS RESERVED #12; AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR Linear Collider (ILC) damping rings. Results from optimizations of the parameters of this wiggler
Is there a use for linear logic? Philip Wadler
Wadler, Philip
Is there a use for linear logic Past attempts to apply Girard's linear logicihavemplemented Wadler's system [Wa* *k90 ].) either had, Wadler), but not both. Thisguage that corresponds closely t* *o linear logic; it is a paper defines
The Stability of Magnetized Rotating Plasmas with Superthermal Fields
Martin E. Pessah; Dimitrios Psaltis
2005-04-13T23:59:59.000Z
During the last decade it has become evident that the magnetorotational instability is at the heart of the enhanced angular momentum transport in weakly magnetized accretion disks around neutron stars and black holes. In this paper, we investigate the local linear stability of differentially rotating, magnetized flows and the evolution of the magnetorotational instability beyond the weak-field limit. We show that, when superthermal toroidal fields are considered, the effects of both compressibility and magnetic tension forces, which are related to the curvature of toroidal field lines, should be taken fully into account. We demonstrate that the presence of a strong toroidal component in the magnetic field plays a non-trivial role. When strong fields are considered, the strength of the toroidal magnetic field not only modifies the growth rates of the unstable modes but also determines which modes are subject to instabilities. We find that, for rotating configurations with Keplerian laws, the magnetorotational instability is stabilized at low wavenumbers for toroidal Alfven speeds exceeding the geometric mean of the sound speed and the rotational speed. We discuss the significance of our findings for the stability of cold, magnetically dominated, rotating fluids and argue that, for these systems, the curvature of toroidal field lines cannot be neglected even when short wavelength perturbations are considered. We also comment on the implications of our results for the validity of shearing box simulations in which superthermal toroidal fields are generated.
6 June 2003 M. Oreglia 1 Linear Collider prehistory
and Universities · LC Resources Towards an International Linear Collider: Mark Oreglia The University of Chicago and make choices and take political actions · Organizations: International Linear Collider Steering
EXTENSIONS OF GENERALIZED LINEAR MODELING APPROACH TO STOCHASTIC WEATHER GENERATORS
Katz, Richard
weather) -- Software R open source statistical programming language: Function glm "Family;(2) Generalized Linear Models Statistical Framework -- Multiple Regression Analysis (Linear model or LM) Response
A LINEAR TIME ALGORITHM FOR THE KOOPMANS-BECKMANN ...
2011-11-24T23:59:59.000Z
said to be linearizable if there exists an instance of the linear assignment problem (LAP) .... quadratic programming formulation to a integer linear programming ...
A polynomial algorithm for linear optimization which is strongly ...
2015-01-31T23:59:59.000Z
In this paper we present a new polynomial algorithm for linear programming. ... linear optimization problems having 0-1 optimal solutions (e.g., the assignment.
Knot Undulator to Generate Linearly Polarized Photons with Low...
Office of Scientific and Technical Information (OSTI)
Linearly Polarized Photons with Low on-Axis Power Density Heat load on beamline optics is a serious problem to generate pure linearly polarized photons in the third...
Relationship Between Solar Wind Speed and Coronal Magnetic Field Properties
Fujiki, Ken'ichi; Iju, Tomoya; Hakamada, Kazuyuki; Kojima, Masayoshi
2015-01-01T23:59:59.000Z
We have studied the relationship between the solar-wind speed $[V]$ and the coronal magnetic-field properties (a flux expansion factor [$f$] and photospheric magnetic-field strength [$B_{\\mathrm{S}}$]) at all latitudes using data of interplanetary scintillation and solar magnetic field obtained for 24 years from 1986 to 2009. Using a cross-correlation analyses, we verified that $V$ is inversely proportional to $f$ and found that $V$ tends to increase with $B_{\\mathrm{S}}$ if $f$ is the same. As a consequence, we find that $V$ has extremely good linear correlation with $B_{\\mathrm{S}}/f$. However, this linear relation of $V$ and $B_{\\mathrm{S}}/f$ cannot be used for predicting the solar-wind velocity without information on the solar-wind mass flux. We discuss why the inverse relation between $V$ and $f$ has been successfully used for solar-wind velocity prediction, even though it does not explicitly include the mass flux and magnetic-field strength, which are important physical parameters for solar-wind accele...
Barclay, J.A.; Steyert, W.A.
1981-01-27T23:59:59.000Z
An apparatus and method for refrigeration are disclosed which provides efficient refrigeration over temperature ranges in excess of 20/sup 0/C and which requires no maintenance and is, therefore, usable on an unmanned satellite. The apparatus comprises a superconducting magnet which may be solenoidal. A piston comprising a substance such as a rare earth substance which is maintained near its Curie temperature reciprocates through the bore of the solenoidal magnet. A magnetic drive rod is connected to the piston and appropriate heat sinks are connected thereto. The piston is driven by a suitable mechanical drive such as an electric motor and cam. In practicing the invention, the body of the piston is magnetized and demagnetized as it moves through the magnetic field of the solenoid to approximate any of the following cycles or a condition thereof as well as, potentially, other cycles: Brayton, Carnot, Ericsson, and Stirling. Advantages of the present invention include: that refrigeration can be accomplished over at least a 20/sup 0/C scale at superconducting temperatures as well as at more conventional temperatures; very high efficiency, high reliability, and small size. (LCL)
Dual-range linearized transimpedance amplifier system
Wessendorf, Kurt O. (Albuquerque, NM)
2010-11-02T23:59:59.000Z
A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).
Test facilities for future linear colliders
Ruth, R.D.
1995-12-01T23:59:59.000Z
During the past several years there has been a tremendous amount of progress on Linear Collider technology world wide. This research has led to the construction of the test facilities described in this report. Some of the facilities will be complete as early as the end of 1996, while others will be finishing up around the end 1997. Even now there are extensive tests ongoing for the enabling technologies for all of the test facilities. At the same time the Linear Collider designs are quite mature now and the SLC is providing the key experience base that can only come from a working collider. All this taken together indicates that the technology and accelerator physics will be ready for a future Linear Collider project to begin in the last half of the 1990s.
Hot Jupiters and stellar magnetic activity
A. F. Lanza
2008-05-20T23:59:59.000Z
Recent observations suggest that stellar magnetic activity may be influenced by the presence of a close-by giant planet. Specifically, chromospheric hot spots rotating in phase with the planet orbital motion have been observed during some seasons in a few stars harbouring hot Jupiters. The spot leads the subplanetary point by a typical amount of about 60-70 degrees, with the extreme case of upsilon And where the angle is about 170 degrees. The interaction between the star and the planet is described considering the reconnection between the stellar coronal field and the magnetic field of the planet. Reconnection events produce energetic particles that moving along magnetic field lines impact onto the stellar chromosphere giving rise to a localized hot spot. A simple magnetohydrostatic model is introduced to describe the coronal magnetic field of the star connecting its surface to the orbiting planet. The field is assumed to be axisymmetric around the rotation axis of the star and its configuration is more general than a linear force-free field. With a suitable choice of the free parameters, the model can explain the phase differences between the hot spots and the planets observed in HD 179949, upsilon And, HD 189733, and tau Bootis, as well as their visibility modulation on the orbital period and seasonal time scales. The possible presence of cool spots associated with the planets in tau Boo and HD 192263 cannot be explained by the present model. However, we speculate about the possibility that reconnection events in the corona may influence subphotospheric dynamo action in those stars producing localized photospheric (and chromospheric) activity migrating in phase with their planets.
E. Florido; E. Battaner
1997-10-17T23:59:59.000Z
In paper I, we obtained an equation for the evolution of density inhomogeneities in a radiation dominated universe when they are affected by magnetic fields. In this second paper we apply this equation to the case in which the subjacent magnetic configuration is a flux tube. For scales of the order of 1 Mpc or less the differential equation is elliptical. To solve it, we have used the numerical method based on "Simultaneous Over Relaxation", SOR, with Chebyshev acceleration and we have treated the problem as a boundary value problem, which restricts the prediction ability of the integration. For large-scale flux tubes, much larger than 1 Mpc, the equation can be analytically integrated and no assumption about the final shape or magnitude of the inhomogeneity is required. In both cases we obtain an evolution which does not differ very much from linear in time. The inhomogeneity in the density becomes filamentary. Large scale structures ($\\ge$ 10 Mpc) are probably unaffected by damping, non-linear and amplification mechanisms after Equality, so that this model provides a tool to interpret the present observed large scale structure. Filaments are very frequently found in the large-scale structure in the Universe. It is suggested here that they could arise from primordial magnetic flux tubes, thus providing an alternative hypothesis for its interpretation; in particular we consider the case of the Coma-A1367 supercluster, where the magnetic field is known to be high.
Linear and NonLinear Estimation Methods Applied to the Hemodynamic model
Schaal, Stefan
Linear and NonLinear Estimation Methods Applied to the Hemodynamic model Evangelos A. Theodorou s that controls the blood inflow. The total balloon model can be defined by the 4 differential equations the hemodynamic process of the balloon model. These equations consist of a set of deterministic highly non
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2008; 15:115139
De Sterck, Hans
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2008; 15:115139 Published and Ulrike Meier Yang2,, 1Department of Applied Mathematics, University of Waterloo, Waterloo, Ont., Canada N2L 3G1 2Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, P.O. Box
1D Regression ... estimates of the linear regression coefficients are relevant to the linear
Olive, David
Chapter 12 1D Regression ... estimates of the linear regression coefficients are relevant and look for a functional form for g(·). Brillinger (1983, p. 98) Regression is the study. The scalar Y is a random variable and x is a random vector. A special case of regression is multiple linear
1D Regression ... estimates of the linear regression coefficients are relevant to the linear
Olive, David
Chapter 15 1D Regression ... estimates of the linear regression coefficients are relevant and look for a functional form for g(·). Brillinger (1983, p. 98) Regression is the study. The scalar Y is a random variable and x is a random vector. A special case of regression is multiple linear
Linear and angular retroreflecting interferometric alignment target
Maxey, L. Curtis (Powell, TN)
2001-01-01T23:59:59.000Z
The present invention provides a method and apparatus for measuring both the linear displacement and angular displacement of an object using a linear interferometer system and an optical target comprising a lens, a reflective surface and a retroreflector. The lens, reflecting surface and retroreflector are specifically aligned and fixed in optical connection with one another, creating a single optical target which moves as a unit that provides multi-axis displacement information for the object with which it is associated. This displacement information is useful in many applications including machine tool control systems and laser tracker systems, among others.
Linear Stability Analysis of Dynamical Quadratic Gravity
Dimitry Ayzenberg; Kent Yagi; Nicolas Yunes
2014-03-18T23:59:59.000Z
We perform a linear stability analysis of dynamical, quadratic gravity in the high-frequency, geometric optics approximation. This analysis is based on a study of gravitational and scalar modes propagating on spherically-symmetric and axially-symmetric, vacuum solutions of the theory. We find dispersion relations that do no lead to exponential growth of the propagating modes, suggesting the theory is linearly stable on these backgrounds. The modes are found to propagate at subluminal and superluminal speeds, depending on the propagating modes' direction relative to the background geometry, just as in dynamical Chern-Simons gravity.
Limitations of controlling oscillators via linear augmentation
Rajat Karnatak
2015-02-15T23:59:59.000Z
In this paper, we will have a look at some examples where linear augmentation is used to control oscillatory systems towards their stationary solutions. The simplicity of linear augmentation is a big positive feature of this scheme but at the same time, questions related to the general applicability of this procedure need to be addressed. This work attempts to demonstrate some control instances where this scheme fails to stabilize the required stationary solutions. Examples from conservative as well as dissipative dynamical systems are presented in this regard and a possible application for dissipative predator--prey dynamics is also discussed.
Aized, D.; Schwall, R.E.
1999-06-22T23:59:59.000Z
A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.
Linear and non-linear forced response of a conical, ducted, laminar premixed flame
Karimi, Nader; Brear, Michael J.; Jin, Seong-Ho; Monty, Jason P. [Department of Mechanical Engineering, University of Melbourne, Parkville, 3010 Vic. (Australia)
2009-11-15T23:59:59.000Z
This paper presents an experimental study on the dynamics of a ducted, conical, laminar premixed flame subjected to acoustic excitation of varying amplitudes. The flame transfer function is measured over a range of forcing frequencies and equivalence ratios. In keeping with previous works, the measured flame transfer function is in good agreement with that predicted by linear kinematic theory at low amplitudes of acoustic velocity excitation. However, a systematic departure from linear behaviour is observed as the amplitude of the velocity forcing upstream of the flame increases. This non-linearity is mostly in the phase of the transfer function and manifests itself as a roughly constant phase at high forcing amplitude. Nonetheless, as predicted by non-linear kinematic arguments, the response always remains close to linear at low forcing frequencies, regardless of the forcing amplitude. The origin of this phase behaviour is then sought through optical data post-processing. (author)
Wireless Magnetic Sensor Applications in Transportation Infrastructure
Sanchez, Rene Omar
2012-01-01T23:59:59.000Z
2.2 Wireless Magnetic Sensors Vehicle Detection2.3 Vehicle Re-Identification Using Wireless MagneticPerformance iv 6 Wireless Magnetic Sensor Applications for
Magnetic spectroscopy and microscopy of functional materials
Jenkins, C.A.
2012-01-01T23:59:59.000Z
transitions for magnetic refrigeration. Appl Phys Lett, 97(these e?ects in magnetic refrigeration and actuation makesheat ?ow with the goal of magnetic refrigeration (adiabatic
Magnetized static black Saturn
Stoytcho S. Yazadjiev
2008-02-06T23:59:59.000Z
We construct a new static solution to the 5D Einstein-Maxwell equations describing a static black hole surrounded by a non-rotating dipole black ring. The configuration is kept in equilibrium by an external magnetic field interacting with the dipole charge of the black ring. The properties of the black Saturn-like configuration are studied and the basic physical quantities are calculated. The solution demonstrates 2-fold continuous non-uniqueness of the 5D magnetized static neutral black objects for fixed total mass and Melvin background.
On the dynamics of magnetic fluids in magnetic resonance imaging
Cantillon-Murphy, Pádraig J
2008-01-01T23:59:59.000Z
The hydrodynamics of magnetic fluids, often termed ferrofluids, has been an active area of research since the mid 1960s. However, it is only in the past twenty years that these fluids have begun to be used in magnetic ...
Dependence of Brownian and Néel relaxation times on magnetic field strength
Deissler, Robert J., E-mail: rjd42@case.edu; Wu, Yong; Martens, Michael A. [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)
2014-01-15T23:59:59.000Z
Purpose: In magnetic particle imaging (MPI) and magnetic particle spectroscopy (MPS) the relaxation time of the magnetization in response to externally applied magnetic fields is determined by the Brownian and Néel relaxation mechanisms. Here the authors investigate the dependence of the relaxation times on the magnetic field strength and the implications for MPI and MPS. Methods: The Fokker–Planck equation with Brownian relaxation and the Fokker–Planck equation with Néel relaxation are solved numerically for a time-varying externally applied magnetic field, including a step-function, a sinusoidally varying, and a linearly ramped magnetic field. For magnetic fields that are applied as a step function, an eigenvalue approach is used to directly calculate both the Brownian and Néel relaxation times for a range of magnetic field strengths. For Néel relaxation, the eigenvalue calculations are compared to Brown's high-barrier approximation formula. Results: The relaxation times due to the Brownian or Néel mechanisms depend on the magnitude of the applied magnetic field. In particular, the Néel relaxation time is sensitive to the magnetic field strength, and varies by many orders of magnitude for nanoparticle properties and magnetic field strengths relevant for MPI and MPS. Therefore, the well-known zero-field relaxation times underestimate the actual relaxation times and, in particular, can underestimate the Néel relaxation time by many orders of magnitude. When only Néel relaxation is present—if the particles are embedded in a solid for instance—the authors found that there can be a strong magnetization response to a sinusoidal driving field, even if the period is much less than the zero-field relaxation time. For a ferrofluid in which both Brownian and Néel relaxation are present, only one relaxation mechanism may dominate depending on the magnetic field strength, the driving frequency (or ramp time), and the phase of the magnetization relative to the applied magnetic field. Conclusions: A simple treatment of Néel relaxation using the common zero-field relaxation time overestimates the relaxation time of the magnetization in situations relevant for MPI and MPS. For sinusoidally driven (or ramped) systems, whether or not a particular relaxation mechanism dominates or is even relevant depends on the magnetic field strength, the frequency (or ramp time), and the phase of the magnetization relative to the applied magnetic field.
Maity, Chandan; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sengupta, Sudip [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2012-10-15T23:59:59.000Z
In a fluid description, we study space-time evolution of lower hybrid modes in a cold quasi-neutral homogeneous plasma in presence of a background inhomogeneous magnetic field. Within a linear analysis, a dispersion relation with inhomogeneous magnetic field shows 'phase mixing' of such oscillations. A manifestation of 'phase mixing' is shown in 'mode coupling.' By using Lagrangian variables, an exact solution is presented in parametric form of this nonlinear time dependent problem. It is demonstrated that initially excited lower hybrid modes always break via phase mixing phenomenon in presence of an inhomogeneous magnetic field. Breaking of such oscillations is revealed by the appearance of spikes in the plasma density profile.
Martin, D A
2015-01-01T23:59:59.000Z
We study evolution equations and stationary homogeneous solutions for electric and magnetic field amplitudes in a ring cavity with flat mirrors. The cavity is filled with a positive or negative refraction index material with third order Kerr-like electric nonlinearities and also magnetic nonlinearities, which can be relevant in metamaterials. We consider the degree of freedom of polarization in the incident beam. It is found that considering a magnetic nonlinearity increases the variety of possible qualitatively different solutions. A classification of solutions is proposed in terms of the number of bifurcations. The analysis can be useful for the implementation of optical switching or memory storage using ring cavities with non linear materials.
Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor
Prokop, C R; Carlsten, B E; Church, M
2013-01-01T23:59:59.000Z
Many front-end applications of electron linear accelerators rely on the production of temporally-compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy ($\\sim 40$ MeV), high-charge (nC) electron bunches with low normalized transverse emittances ($< 5$ $\\mu$m).
Modular Permanent Magnet Machine Based on Soft Magnetic *** Burgess-Norton Mfg.Co.
Lipo, Thomas
. The rotor structure can be designed with surface permanent magnet (SPM) or internal permanent magnet (IPM
QUEEN'S DUPONT BACK PAIN STUDY Calibration of a Magnetic Tracking Device Using Locally Linear Fits
Murdoch, Duncan
point i, p is a power variable used to compensate for distance related measurement variance with a grid spacing of 40cm. 1440 data points were collected at 60 positions. For each point, the true position vector x=(x,y,z) and the true orientation At were known, and the observed position vector xo
Measurements of the effect of a magnetic field on the transport of linear momentum in nitrogen
Larchez, Mark Edward
1968-01-01T23:59:59.000Z
torgue in the same direction. A torque in the direction opposite to this is produced by methane, et'nane, propane, butane, isobutane, 7 hydrogen, nydrogen deuteride, and ceuterium, No torque is shown by helium, argon, xenon, water vapor, carbon...
Non-Linear Magnetic Ringing of Spin-Ordered Solid He-3
Hu, Chia-Ren; HAM, TE.
1981-01-01T23:59:59.000Z
be well fitted by the formula [(uL + I)0 + [ ( cuL IIO) +4cuL I)a cos Q] I where ~L ?= yH is the Larmor frequency, and the + sign indicates that there are two resonance branches at any given applied field H. Furthermore, they have shown... the integral in Eq. (17) in terms of a Jacobian elliptical integral 2.2 2.0 1.8 1.6 sing(=d, ) = ?X sn(X+rlnt) m = (X-IX+)', (19) which also gives the time dependence of dq~ =1 ?d,', sg =sp S1n H ?d, and s =sp ?d Evaluating (B,s?)~+(B,sy)~ and ((l...
Physics Case for the International Linear Collider
Keisuke Fujii; Christophe Grojean; Michael E. Peskin; Tim Barklow; Yuanning Gao; Shinya Kanemura; Hyungdo Kim; Jenny List; Mihoko Nojiri; Maxim Perelstein; Roman Poeschl; Juergen Reuter; Frank Simon; Tomohiko Tanabe; Jaehoon Yu; James D. Wells; Hitoshi Murayama; Hitoshi Yamamoto
2015-06-26T23:59:59.000Z
We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.
Physics Case for the International Linear Collider
Fujii, Keisuke; Peskin, Michael E; Barklow, Tim; Gao, Yuanning; Kanemura, Shinya; Kim, Hyungdo; List, Jenny; Nojiri, Mihoko; Perelstein, Maxim; Poeschl, Roman; Reuter, Juergen; Simon, Frank; Tanabe, Tomohiko; Yu, Jaehoon; Wells, James D; Murayama, Hitoshi; Yamamoto, Hitoshi
2015-01-01T23:59:59.000Z
We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.
Automatic tuning for linearly tunable filter
Huang, Sung-Ling
2004-09-30T23:59:59.000Z
A new tuning scheme for linearly tunable high-Q filters is proposed. The tuning method is based on using the phase information for both frequency and Q factor tuning. There is no need to find out the relationship between a filter's passband...
Numerical Linear Algebra and Optimization on Facebook
Sidorov, Nikita
Numerical Linear Algebra and Optimization on Facebook: "In a relationship" or "It's complicated indicate their "relationship status" on Facebook (!!!). (I don't need to define Facebook, right?) #12;Facebook is close to ubiquitous (1.2 billion users in March 2014). 556 million people log on to Facebook
Linear Signal Reconstruction from Jittered Sampling
Paris-Sud XI, Université de
Linear Signal Reconstruction from Jittered Sampling Alessandro Nordio (1) , Carla jitter, which is based on the analysis of the mean square error (MSE) between the reconstructed sig- nal of digital signal reconstruction as a function of the clock jitter, number of quantization bits, signal
Linearity -statistics 1.1B training
Linearity - statistics IPAT 1.1B training 300M training D0 resolution is evaluated using 100k single muon events (same events in all 3 plots). Red is the default 11L FTK bank trained using 300M muons on narrow beam of muons (central eta, fixed phi, high fixed pT). Using two types of training: default FTK
Robotic Motion The linear algebra of Canadarm
Murty, Ram
Robotic Motion The linear algebra of Canadarm #12;The robot arm simulation The movements of the robotic arm can be described using orthogonal matrices. #12;Six degrees of freedom The first segment the robotic arm to the position (x,y), we need to rotate the first arm by an angle and the second arm
Performance Bounds for Constrained Linear Stochastic Control
Engineering Department Stanford University Workshop on Optimization and Control with Applications, Harbin · numerical examples Workshop on Optimization and Control with Applications, Harbin, June 9 2009 1 #12;Linear is zero mean IID process noise, E wtwT t = W · state feedback control policy: ut = (xt), t = 0, 1
GENERALIZED LINEAR MODELS WITH REGULARIZATION A DISSERTATION
Hastie, Trevor
GENERALIZED LINEAR MODELS WITH REGULARIZATION A DISSERTATION SUBMITTED TO THE DEPARTMENT Park 2006 All Rights Reserved ii #12;I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor
Introduction to Statistical Linear Models Spring 2005
of multivariate data and in the language of matrices and vectors. Broad introduction to MATLAB/Octave, R (SSyllabus Introduction to Statistical Linear Models 960:577:01 Spring 2005 Instructor: Farid Statistical Analysis" Fifth edition, Prentice Hall, 2002. Other sources may be required and will be posted
MA265 Linear Algebra — Sample Exam 1
page 1. Purdue University. MA265 Linear Algebra — Sample Exam 1. Date: February 20, 2015 Duration: 50 ... 1. Determine A such that (let-(A). 7 .110 [p. 1100 O r. In. )1 A n 1. \\\\\\\\l_ he zlxrs M. \\11. '01 .... Rep'mr'ata. 1 F'ncl '3“ m muVVnN
Linear-quadratic fractional Gaussian control
Duncan, Tyrone E.; Pasik-Duncan, Bozenna
2013-01-01T23:59:59.000Z
In this paper a control problem for a linear stochastic system driven by a noise process that is an arbitrary zero mean, square integrable stochastic process with continuous sample paths and a cost functional that is quadratic in the system state...
Development of a Novel Linear Magnetostrictive Actuator
Sadighi, Ali
2010-10-12T23:59:59.000Z
. ............................................................. 11 Fig. 1.9. Photograph of the extended-range linear magnetostrictive actuator with double-sided three-phase stators. ............................................................................ 12 Fig. 2.1. The overall design process...-D Slab ..........................................................................................39 3.2.2 Stator...........................................................................................................41 ix Page 3.3 Winding...
STANFORD LINEAR ACCELERATOR CENTER DIRECTOR'S OFFICE
Wechsler, Risa H.
of these offices not listed here. PART 1: RESEARCH & DEVELOPMENT PROGRAM MANAGEMENT RECORDS R&D Program Management records document the basis for research and development program management decisions, direction, policiesSTANFORD LINEAR ACCELERATOR CENTER DIRECTOR'S OFFICE RECORDS CONTROL SCHEDULE SCOPE: This schedule
Automatic tuning for linearly tunable filter
Huang, Sung-Ling
2004-09-30T23:59:59.000Z
A new tuning scheme for linearly tunable high-Q filters is proposed. The tuning method is based on using the phase information for both frequency and Q factor tuning. There is no need to find out the relationship between a filter's passband...
Diabetes Mellitus Glucose Prediction by Linear and
Diabetes Mellitus Glucose Prediction by Linear and Bayesian Ensemble Modeling Fredrik St was diagnosed with diabetes type 1. Being an engineer with a control and systems oriented curriculum I realized of diabetes glucose metabolism, and bringing new hope of technical solutions to support the management
Linear Algebra MATH 110 : 2006-07
Wehlau, David
MATH 110 Linear Algebra MATH 110 : 2006-07 Home Policies Fall Winter WebCT Instructor: G.G. Smith: MATH 111, 112 Lectures: (slot 014) Tuesday, 11:30-12:30 in 210 Walter Light Hall Wednesday, 13:30-14:30 in 210 Walter Light Hall Friday, 12:30-13:30 in 210 Walter Light Hall Tutorials: Wednesday, 8
Algebra Linear -Exercicios resolvidos Exercicio 1
Dias, Esmeralda Sousa
´Algebra Linear - Exerc´icios resolvidos Exerc´icio 1: Sejam E = L({(1, 1, 1), (1, 2, 2)}) e F = L~ao de E F ´e 1. Exerc´icio 2: No espa¸co dos polin´omios reais de grau menor ou igual a 3, P3
Architecture of an Automatic Tuned Linear Algebra
Cuenca, Javier
.... SPt c,z Architecture of a Self-Optimised Linear Algebra Routine (SOLAR) Installation_information n1 Current_network_availability % net1-1 ...%net1-p ... % netP-1 ..%netp-p SOLAR_manager Optimum_AP AP0 Algebra Routine of the library we want to build SOLAR_manager Manages the information and code of SOLAR
Paris-Sud XI, Université de
-dimensionally-modulated, magnetic structure of neodymium metal B. Lebech Physics Department, Risra National Laboratory, DK-4000, is linear combinations of the terms where the parameters p,, p,, p, and 0 must be deter- mined://dx.doi.org/10.1051/jphyscol:1979503 #12;TWO-DIMENSIONALLY-MODULATED, MAGNETIC STRUCTURE OF NEODYMIUM METAL C5
Modeling of magnetic island formation in magnetic reconnection experiment
Ji, Hantao
the spontaneous FRC formation with effective plasma heating by magnetic reconnection.6 In the Magnetic, Gifu, 509-5292, Japan M. Yamada and H. Ji Plasma Physics Laboratory, Princeton University, Princeton found in the Magnetic Reconnection Experiment MRX M. Yamada, H. Ji, S. Hsu, et al., Phys. Plasmas 4
Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms
Bhatia, Sangeeta
Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms for in vivo Tumor Targeting and Engineering Program Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman magnetic materials nanoworms peptides tumor targeting 694 ß 2009 Wiley-VCH Verlag GmbH & Co. KGa
APPENDIX 475 C. Some Results from Linear Algebra
Gajic, Zoran
APPENDIX 475 C. Some Results from Linear Algebra Linear algebra plays a very important role some standard and important linear algebra results. Definite Matrices Definition C.1: A square matrix of dimensions 798A@ is the space spanned by vectors B that satisfy CDBFEHG . Systems of Linear Algebraic
Datadriven calibration of linear estimators with minimal penalties
This paper tackles the problem of selecting among several linear estimators in non parametric regression; this includes model selection for linear regression, the choice of a regularization parameter in kernel ridge classification, with linear and non linear predictors [37, 36]. A central issue common to all regularization
Data-driven calibration of linear estimators with minimal penalties
Paris-Sud XI, Université de
This paper tackles the problem of selecting among several linear estimators in non- parametric regression; this includes model selection for linear regression, the choice of a regularization parameter in kernel ridge classification, with linear and non- linear predictors [37, 36]. A central issue common to all regularization
STABILIZING SUPERVISORY CONTROL OF HYBRID SYSTEMS BASED ON PIECEWISE LINEAR
Antsaklis, Panos
STABILIZING SUPERVISORY CONTROL OF HYBRID SYSTEMS BASED ON PIECEWISE LINEAR LYAPUNOV FUNCTIONS1 Lyapunov func- tions. In particular, we consider discrete-time switched linear systems. The control problem of discrete-time piecewise linear hybrid systems is in- vestigated using piecewise linear Lyapunov functions
Controllability of Linear Systems with inner derivation on Lie Groups
Boyer, Edmond
Controllability of Linear Systems with inner derivation on Lie Groups Philippe JOUAN November 2 group of automorphisms. A control-ane system is linear if the drift is linear and the controlled vector groups are stated. The paper ends by many examples. Keywords: Lie groups; Linear systems; controllability
A Linear Programming based Satisfiability solver using a new
Rossi, Francesca
is unsatisfiable or has a satisfying assignment, we solve a linear program. The solution of the linear program a satisfying assignment or a contradiction we solve a linear program. By the above men- tioned lemmaA Linear Programming based Satisfiability solver using a new Horn-driven search tree design Hans
1. INTRODUCTION It is relatively easy to control linear systems.
Wilamowski, Bogdan Maciej
of the biggest challenges in modern control theory. While linear control system theory has been well developed1. INTRODUCTION It is relatively easy to control linear systems. Unfortunately, in practice most systems are nonlinear. Some of them can be linearized and use well developed linear control theory
Method of Linear Invariants for description of beam dynamics of FEL undulator
A. Angelow; D. Trifonov; V. Angelov; H. Hristov
2008-05-23T23:59:59.000Z
We propose a new model for description of electrons beam dynamics in Free Electron Laser (FEL) undulator, based on the method of linear time-dependent invariants of quantum-mechanical charge particle. The magnetic field has periodic structure along the undulator. For this problem, described by time-dependent quadratic Hamiltonian, we obtain exact solution. The time-evolutions of the tree quantum fluctuations: covariance cov(q,p), var(q) and var(p) for the charge particle in this case are also determined. This research will help to optimize the FEL undulator: for example, using a 2.5 GeV linear electron accelerator it will be possible to emit radiation at 1.5 nm and shorter length. This method could be applicable also to any device with periodic structure of applied field (e.g. Tokamak, cyclic accelerators) for the case of charge non-relativistic quantum particles.
Solar receiver heliostat reflector having a linear drive and position information system
Horton, Richard H. (Schenectady, NY)
1980-01-01T23:59:59.000Z
A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.
Simulation of non-linear rf losses derived from characteristic Nb topography
Reece, Charles E. [JLAB; Xu, Chen; Kelley, Michael [W& M. JLAB
2013-09-01T23:59:59.000Z
A simplified model has been developed to simulate non-linear RF losses on Nb surfaces exclusively due to topographical enhancement of surface magnetic fields. If local sharp edges are small enough, at locations where local surface fields exceed Hc, small volumes of material may become normal conducting without thermal leading to quench. These small volumes of normal material yield increases in the effective surface resistance of the Nb. Using topographic data from typical BCP?d and EP?d fine grain niobium surfaces, we have simulated field-dependent losses and found that when extrapolated to resulting cavity performance, these losses correspond well to characteristic BCP/EP high field Q0 performance differences for fine grain Nb. We describe the structure of the model, its limitations, and the effects of this type of non-linear loss contribution on SRF cavities.
Investigation into electron cloud effects in the International Linear Collider positron damping ring
Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.; Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.
2014-02-28T23:59:59.000Z
We report modeling results for electron cloud buildup and instability in the International Linear Collider positron damping ring. Updated optics, wiggler magnets, and vacuum chamber designs have recently been developed for the 5 GeV, 3.2-km racetrack layout. An analysis of the synchrotron radiation profile around the ring has been performed, including the effects of diffuse and specular photon scattering on the interior surfaces of the vacuum chamber. The results provide input to the cloud buildup simulations for the various magnetic field regions of the ring. The modeled cloud densities thus obtained are used in the instability threshold calculations. We conclude that the mitigation techniques employed in this model will suffice to allow operation of the damping ring at the design operational specifications
Large Magnetization at Carbon Surfaces
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure...
Magnetic refrigeration apparatus and method
Barclay, John A. (Los Alamos, NM); Overton, Jr., William C. (Los Alamos, NM); Stewart, Walter F. (Los Alamos, NM)
1984-01-01T23:59:59.000Z
The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.
CONSTRAINING THREE-DIMENSIONAL MAGNETIC FIELD EXTRAPOLATIONS USING THE TWIN PERSPECTIVES OF STEREO
Conlon, Paul A.; Gallagher, Peter T. [Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
2010-05-20T23:59:59.000Z
The three-dimensional magnetic topology of a solar active region (NOAA 10956) was reconstructed using a linear force-free field extrapolation constrained using the twin perspectives of STEREO. A set of coronal field configurations was initially generated from extrapolations of the photospheric magnetic field observed by the Michelson Doppler Imager on SOHO. Using an EUV intensity-based cost function, the extrapolated field lines that were most consistent with 171 A passband images from the Extreme UltraViolet Imager on STEREO were identified. This facilitated quantitative constraints to be placed on the twist ({alpha}) of the extrapolated field lines, where {nabla} x B = {alpha}B. Using the constrained values of {alpha}, the evolution in time of twist, connectivity, and magnetic energy were then studied. A flux emergence event was found to result in significant changes in the magnetic topology and total magnetic energy of the region.
Mansuripur, Masud
2015-01-01T23:59:59.000Z
The classical theory of electrodynamics cannot explain the existence and structure of electric and magnetic dipoles, yet it incorporates such dipoles into its fundamental equations, simply by postulating their existence and properties, just as it postulates the existence and properties of electric charges and currents. Maxwell's macroscopic equations are mathematically exact and self-consistent differential equations that relate the electromagnetic (EM) field to its sources, namely, electric charge-density $\\rho_{free}$, electric current-density $J_{free}$, polarization P, and magnetization M. At the level of Maxwell's macroscopic equations, there is no need for models of electric and magnetic dipoles. For example, whether a magnetic dipole is an Amperian current-loop or a Gilbertian pair of north and south magnetic monopoles has no effect on the solution of Maxwell's equations. Electromagnetic fields carry energy as well as linear and angular momenta, which they can exchange with material media - the seat of...
Overview of the bump-magnet system at the LANSCE proton storage ring
Rose, C.R.; Barlow, D.B.; Blind, B.; Neri, F.; Power, J.F.; Walstrom, P.L.
1997-09-01T23:59:59.000Z
An upgrade program for increasing the stored beam current in the Proton Storage is presently under way. A part of the upgrade is the design and installation of a four-magnet beam-bumping system used for phase-space painting and minimizing interaction of the stored beam with the injection stripper foil. This paper describes the bump- magnet system including the relevant beam requirements, magnet specifications, power-cable specifications, pulsed-modulator requirements, and beam-tube eddy-current effects. The magnets are ferrite window-frame magnets with saddle windings. The series-pass pulsed modulators are programmable both in rise and fall time as well as amplitude. The peak current can be varied between 50 and 300 A. The pulsed-current rise-time is fixed at 1 ms, and the linear fall- time during which beam is injected into the ring can be varied between 0.5 and 1.5 ms.
Kirol, L.D.
1987-02-11T23:59:59.000Z
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.
Kirol, Lance D. (Shelly, ID)
1988-01-01T23:59:59.000Z
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.
Integer Algorithms to Solver Diophantine Linear Equations and Systems
Florentin Smarandache
2007-11-28T23:59:59.000Z
The present work includes some of the author's original researches on integer solutions of Diophantine liner equations and systems. The notion of "general integer solution" of a Diophantine linear equation with two unknowns is extended to Diophantine linear equations with $n$ unknowns and then to Diophantine linear systems. The proprieties of the general integer solution are determined (both for a Diophantine linear equation and for a Diophantine linear system). Seven original integer algorithms (two for Diophantine linear equations, and five for Diophantine linear systems) are exposed. The algorithms are strictly proved and an example for each of them is given. These algorithms can be easily implemented on the computer.
Linear study of Rayleigh-Taylor instability in a diffusive quantum plasma
Momeni, Mahdi [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)] [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)
2013-08-15T23:59:59.000Z
The linear Rayleigh-Taylor (RT) instability in an incompressible quantum plasma is investigated on the basis of quantum magnetohydrodynamic model. It is shown that the occurrence of RT instability depends on density-temperature inhomogeneity (characteristic lengths) on one hand, and the system layer size on the other. It is also observed that the combined effects of external magnetic field, diffusivity, and quantum pressure significantly modify the dispersion properties of system in both the parallel and perpendicular directions. For any case, the imaginary and real parts of dispersion relation are presented and the possibility and conditions for the instability growth rate are discussed.
Semiclassical bounds in magnetic bottles
Diana Barseghyan; Pavel Exner; Hynek Kovarik; Timo Weidl
2015-01-13T23:59:59.000Z
The aim of the paper is to derive spectral estimates into several classes of magnetic systems. They include three-dimensional regions with Dirichlet boundary as well as a particle in $\\mathbb{R}^3$ confined by a local change of the magnetic field. We establish two-dimensional Berezin-Li-Yau and Lieb-Thirring-type bounds in the presence of magnetic fields and, using them, get three-dimensional estimates for the eigenvalue moments of the corresponding magnetic Laplacians.
Ames Lab 101: Magnetic Refrigeration
Pecharsky, Vitalij
2013-03-01T23:59:59.000Z
Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.
Ames Lab 101: Magnetic Refrigeration
Pecharsky, Vitalij
2011-01-01T23:59:59.000Z
Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.
Magnetic reconnection in nontoroidal plasmas
Boozer, Allen H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
2005-07-15T23:59:59.000Z
Magnetic reconnection is a major issue in solar and astrophysical plasmas. The mathematical result that the evolution of a magnetic field with only point nulls is always locally ideal limits the nature of reconnection in nontoroidal plasmas. Here it is shown that the exponentially increasing separation of neighboring magnetic field lines, which is generic, tends to produce rapid magnetic reconnection if the length of the field lines is greater than about 20 times the exponentiation, or Lyapunov, length.
Magnetic refrigeration for spacecraft systems
Barclay, J.A.
1981-01-01T23:59:59.000Z
Magnetic refrigerators, i.e., those that use the magnetocaloric effect of a magnetic working material in a thermodynamic cycle, offer potentially reliable, and efficient refrigeration over a variety of temperature ranges and cooling powers. A descriptive analysis of magnetic refrigeration systems is performed with particular emphasis on more efficient infrared detector cooling. Three types of magnetic refrigerator designs are introduced to illustrate some of the possibilities.
SU-E-J-233: A Facility for Radiobiological Experiments in a Large Magnetic Field
Carlone, M; Heaton, R; Keller, H [Princess Margaret Hospital, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada); Wouters, B [Ontario Cancer Institute, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada); Jaffray, D [Princess Margaret Hospital, Toronto, ON (Canada); Ontario Cancer Institute, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada)
2014-06-01T23:59:59.000Z
Purpose: There is considerable interest in developing medical linear accelerators with integrated image guidance by MRI. Less work has been done on the fundamental biology of cell survival in the presence of a strong magnetic field. The purpose of this work is to describe an experimental system capable of measuring cell survival response in the types of MRI-linac systems currently under development. Methods: We have integrated a cobalt irradiator with a solenoid magnet. The solenoid magnet has inner diameter of 10 cm. To enable measurement of the biological effects as a function of depth, we are utilizing the sliced gel technique, in which cells are embedded and fixed within a gelatin matrix. Irradiated cells at defined positions (sub mm resolution) can subsequently be recovered and assessed for cell survival or other biological effects. Results: The magnetic field profile in the solenoid has a peak magnetic field 36 cm below the top edge of the magnet bore and can be placed at and SAD of 100 cm. At a solenoid current of 35 A, the peak magnetic field is 0.25 T. The dose rate of the cobalt irradiator is 16 cGy/min at 100 cm SAD. EBT3 film was used to demonstrate the system functionality. It was irradiated at 1 cm depth at 100 cm SSD with a 4×4 field to 1.5 Gy in a 0.25 T magnetic field. The dose profile was similar between this film and the control exposure without magnetic field. Conclusion: Integrating a cobalt irradiator with a high field magnet is demonstrated. The magnetic field at the cobalt defining head was minimal and did not interfere with the functioning of this unit. Cell survival experiments can be reproduced exactly in the presence or absence of a magnetic field since a resistive magnet is used.
The two-phase issue in the O(n) non-linear $?$-model: A Monte Carlo study
B. Alles; A. Buonanno; G. Cella
1996-08-01T23:59:59.000Z
We have performed a high statistics Monte Carlo simulation to investigate whether the two-dimensional O(n) non-linear sigma models are asymptotically free or they show a Kosterlitz- Thouless-like phase transition. We have calculated the mass gap and the magnetic susceptibility in the O(8) model with standard action and the O(3) model with Symanzik action. Our results for O(8) support the asymptotic freedom scenario.
Magnetic reconnection launcher
Cowan, M.
1987-04-06T23:59:59.000Z
An electromagnetic launcher includes a plurality of electrical stages which are energized sequentially in the launcher with the passage of a projectiles. Each stage of the launcher includes two or more coils which are arranged coaxially on either closed-loop or straight lines to form gaps between their ends. The projectile has an electrically conductive gap-portion that passes through all the gaps of all the stages in a direction transverse to the axes of the coils. The coils receive an electric current, store magnetic energy, and convert a significant portion of the stored magnetic energy into kinetic energy of the projectile moves through the gap. The magnetic polarity of the opposing coils is in the same direction, e.g. N-S-N-S. A gap portion of the projectile may be made from aluminum and is propelled by the reconnection of magnetic flux stored in the coils which causes accelerating forces to act upon the projectile and at the horizontal surfaces of the projectile near its rear. The gap portion of the projectile may be flat, rectangular and longer than the length of the opposing coils. The gap portion of the projectile permits substantially unrestricted distribution of the induced currents so that current densities are only high where the useful magnetic force is high. This allows designs which permit ohmic oblation from the rear surfaces of the gap portion of the projectile allowing much high velocities to be achieved. An electric power apparatus controls the electric power supplied to the opposing coils until the gap portion of the projectile substantially occupies the gap between the coils, at which time the coils are supplied with peak current quickly. 8 figs.
Low-temperature magnetic refrigerator
Barclay, John A. (Los Alamos, NM)
1985-01-01T23:59:59.000Z
The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.
Enlarge Image Peer pressure. Magnetic
Thywissen, Joseph
to stick it to your refrigerator, but an ultra-cold gas magnetizes itself just as do metals such as ironEnlarge Image Peer pressure. Magnetic domains in steel (vertical bans) arise when neighboring electrons point their magnetic poles in the same direction. CREDIT: ZUREKS, CHRIS VARDON
Low-temperature magnetic refrigerator
Barclay, J.A.
1983-05-26T23:59:59.000Z
The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.
Weston, Ken
at the Magnet Lab like? Often, it's about solving problems. That's what engineers Scott Bole and Lee Marks didRobotics Club! page 16 Using magnets to analyze oil page 28 #12;editor's note What's a typical day recently. Their story began when Lee noticed something odd going on during a magnet-building project: When
LABORATORY VI ELECTRICITY FROM MAGNETISM
Minnesota, University of
LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored the magnetic field and its effect on moving charges. You also saw how electric currents could create magnetic can give rise to electric currents. This is the effect that allows the generation of electricity
Garmestani, Hamid
of thermal conductance in a composite material assuming a linear law of mixing, and nanotubepolymerEnhancement of thermal and electrical properties of carbon nanotube polymer composites by magnetic and electrical properties of single wall carbon nanotube CNT -polymer composites are significantly enhanced
Electric field of a point-like charge in a strong magnetic field
A. E. Shabad; V. V. Usov
2006-07-22T23:59:59.000Z
We describe the potential produced by a point electric charge placed into a constant magnetic field, so strong that the electron Larmour length is much shorter than its Compton length. The standard Coulomb law is modified due to the vacuum polarization by the external magnetic field. Only mode-2 photons mediate the static interaction. The corresponding vacuum polarization component, taken in the one-loop approximation, grows linearly with the magnetic field. Thanks to this fact a scaling regime occurs in the limit of infinite magnetic field, where the potential is determined by a universal function, independent the magnetic field. The scaling regime implies a short-range character of interaction in the Larmour scale, expressed as a Yukawa law. On the contrary, the electromagnetic interaction regains its long-range character in a larger scale, characterized by the Compton length. In this scale the tail of the Yukawa potential follows an anisotropic Coulomb law: it decreases as the distance from the charge increases, slower along the magnetic field and faster across. The equipotential surface is an ellipsoid stretched along the magnetic field. As a whole, the modified Coulomb potential is a narrower-shaped function than the standard Coulomb function, the narrower the stronger the field. The singular behavior in the vicinity of the charge remains unsuppressed by the magnetic field. These results may be useful for studying atomic spectra in super- strong magnetic fields of several Schwinger's characteristic values.
Electrostatic waves in carbon nanotubes with an axial magnetic field
Abdikian, Alireza [Department of Physics, Malayer University, Malayer 65719-95863 (Iran, Islamic Republic of)] [Department of Physics, Malayer University, Malayer 65719-95863 (Iran, Islamic Republic of); Bagheri, Mehran [Laser and Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19835-63113 (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19835-63113 (Iran, Islamic Republic of)
2013-10-15T23:59:59.000Z
Based on a linearized hydrodynamic model and within the quasi-static approximation, the dispersion relation of electrostatic waves propagating through single-walled carbon nanotubes subject to an axial magnetic field is theoretically explored. In the classical limit, we obtain two main possible waves which in turn are divided into two branches, a low-frequency acoustical and a high-frequency optical plasmon branch. In the quantum case, we have found that the dispersion relation is substantially modified when the electron wavelength becomes large enough compared to the propagation wavelength of the electrostatic waves in the quantum plasma. We also show that the axial magnetic field manifest itself on the perturbed electron density through the quantum term and gives rise to the propagation of the electrostatic waves within the quantum plasma. As a result, the effect of the magnetic field is pronounced in the plasma dispersion relations in such a way that their curves approach to zero when the magnetic field is weak; and for the strong magnetic field, they asymptotically meet the constant lines.
Wireless Magnetic Sensor Applications in Transportation Infrastructure
Sanchez, Rene Omar
2012-01-01T23:59:59.000Z
of wireless magnetic sensors in Intelligent Trans- portationof wireless magnetic sensors in Intelligent Transportationmagnetic sensors for different Intelligent Transportation
Towards a Future Linear Collider and The Linear Collider Studies at CERN
None
2011-10-06T23:59:59.000Z
During the week 18-22 October, more than 400 physicists will meet at CERN and in the CICG (International Conference Centre Geneva) to review the global progress towards a future linear collider. The 2010 International Workshop on Linear Colliders will study the physics, detectors and accelerator complex of a linear collider covering both the CLIC and ILC options. Among the topics presented and discussed will be the progress towards the CLIC Conceptual Design Report in 2011, the ILC Technical Design Report in 2012, physics and detector studies linked to these reports, and an increasing numbers of common working group activities. The seminar will give an overview of these topics and also CERN?s linear collider studies, focusing on current activities and initial plans for the period 2011-16. n.b: The Council Chamber is also reserved for this colloquium with a live transmission from the Main Auditorium.
Method of making permanent magnets
McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.
1993-09-07T23:59:59.000Z
A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.
Magnetic Edge States in Graphene
Gabriela Murguia
2010-08-29T23:59:59.000Z
Magnetic confinement in graphene has been of recent and growing interest because its potential applications in nanotechnology. In particular, the observation of the so called magnetic edge states in graphene has opened the possibility to deepen into the generation of spin currents and its applications in spintronics. We study the magnetic edge states of quasi-particles arising in graphene monolayers due to an inhomogeneous magnetic field of a magnetic barrier in the formalism of the two-dimensional massless Dirac equation. We also show how the solutions of such states in each of both triangular sublattices of the graphene are related through a supersymmetric transformation in the quantum mechanical sense.
Linear tailored gain broad area semiconductor lasers
Lindsey, C.P.; Mehuys, D.; Yariv, A.
1987-06-01T23:59:59.000Z
Tailored gain semiconductor lasers capable of high-power operation with single-lobed, nearly diffraction limited beamwidths only a few degrees wide have been demonstrated in proton implanted chirped arrays and ''halftone'' broad area lasers. The authors analyze lasers with a linear gain gradient, and obtain analytic approximations for their unsaturated optical eigenmodes. Unlike a uniform array, the fundamental mode of a linear tailored gain laser is the mode at threshold. Mode discrimination may be controlled by lasing the spatial gain gradient. All modes of asymmetric tailored gain waveguides have single-lobed far-field patterns offset from 0/sup 0/. Finally, they utilize tailored gain broad area lasers to make a measurement of the antiguiding parameter, and find b = 2.5 +- 0.5, in agreement with previous results.
Enhanced dielectric-wall linear accelerator
Sampayan, S.E.; Caporaso, G.J.; Kirbie, H.C.
1998-09-22T23:59:59.000Z
A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 6 figs.
Partially linear models with unit roots
Juhl, Ted P.; Xiao, Z. J.
2005-10-01T23:59:59.000Z
~y tH110021 * H11002 [y tH110021 * !~e t H11002 [e t H11001g~x t !H11002 [g~x t !! Zf t 2 H11001o p ~1!+ PARTIALLY LINEAR MODELS WITH UNIT ROOTS 897 The theorem holds because 1 N 2 ( tH110051 N ~y tH110021 * H11002 [y tH110021 * ! 2 Zf t 2 nE~f 2 !s v... in econometrics+ One type of these models is the following partially linear regression: y t H11005g ' z t H11001g~x t !H11001e t , tH110051,+++,N, (1.1) where g~{! is an unknown real function and g is the vector of unknown param- eters that we want to estimate...
Enhanced dielectric-wall linear accelerator
Sampayan, Stephen E. (Manteca, CA); Caporaso, George J. (Livermore, CA); Kirbie, Hugh C. (Dublin, CA)
1998-01-01T23:59:59.000Z
A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.