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1

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Wednesday, 29 August 2007 00:00 Using spectroscopic information for magnetometry and magnetic microscopy obviously requires detailed theoretical understanding of spectral shape and magnitude of dichroism signals. A research team at ALS Beamline 4.0.2 has now shown unambiguously that, contrary to common belief, spectral shape and magnitude of x-ray magnetic linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays

2

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Using spectroscopic information for magnetometry and magnetic microscopy obviously requires detailed theoretical understanding of spectral shape and magnitude of dichroism signals. A research team at ALS Beamline 4.0.2 has now shown unambiguously that, contrary to common belief, spectral shape and magnitude of x-ray magnetic linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays The ancient Greeks and also the Chinese knew about strange and rare stones with the power to attract iron. Moreover, when freely suspended these objects pointed north-south. Throughout the past, we have used this phenomenon-magnetism-for navigation and more recently for power production and digital information storage, all while trying to explore and understand its origins. In 1986 researchers at a facility similar to the ALS observed for the first time that the absorption of x rays depends not only on the composition of a material-that is, if it contains iron, nickel, or other elements-but also on its magnetism. The effect is unique in that it allows us to distinguish which atomic species magnetism originates from and provides information about their local atomic environment-for example, whether a magnetic species is surrounded by 4 or 6 oxygen atoms. A research team at the ALS has now shown that the relationship between magnetic order and absorption of x rays is even more complex and exciting than has been assumed for the past 20 years, leading to a reassessment of previous results.

3

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism  

NLE Websites -- All DOE Office Websites (Extended Search)

Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Unexpected Angular Dependence of X-Ray Magnetic Linear Dichroism Print Using spectroscopic information for magnetometry and magnetic microscopy obviously requires detailed theoretical understanding of spectral shape and magnitude of dichroism signals. A research team at ALS Beamline 4.0.2 has now shown unambiguously that, contrary to common belief, spectral shape and magnitude of x-ray magnetic linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x-ray polarization, but their orientation relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data. Magnetism and X Rays The ancient Greeks and also the Chinese knew about strange and rare stones with the power to attract iron. Moreover, when freely suspended these objects pointed north-south. Throughout the past, we have used this phenomenon-magnetism-for navigation and more recently for power production and digital information storage, all while trying to explore and understand its origins. In 1986 researchers at a facility similar to the ALS observed for the first time that the absorption of x rays depends not only on the composition of a material-that is, if it contains iron, nickel, or other elements-but also on its magnetism. The effect is unique in that it allows us to distinguish which atomic species magnetism originates from and provides information about their local atomic environment-for example, whether a magnetic species is surrounded by 4 or 6 oxygen atoms. A research team at the ALS has now shown that the relationship between magnetic order and absorption of x rays is even more complex and exciting than has been assumed for the past 20 years, leading to a reassessment of previous results.

4

Surface-Sensitive, Element-Specific Magnetometry with X-Ray Linear Dichroism  

SciTech Connect

Here it is shown that the magnetic linear dichroism in x-ray photoemission (XMLD) signal can be used to measure the element specific magnetic moments in ultra thin alloy films. Comparison with recent SQUID data provides a quantitative check that demonstrates that the total magnetization derived from summing the constituent elemental moments is correct.

Schumann, F.O.; Willis, R.F.; Tobin, J.G.

1999-10-06T23:59:59.000Z

5

Magnetic Dichroism Spectromicroscopy at SPEAR3  

NLE Websites -- All DOE Office Websites (Extended Search)

Dichroism Absorption Microscopy and Spectroscopy at the SSRL Dichroism Absorption Microscopy and Spectroscopy at the SSRL XDSM Examples X-ray absorption spectroscopy (XAS) utilizes the energy dependent absorption of x-rays to obtain information about the elemental composition of the sample and the chemical environment of each element (see also NEXAFS Spectroscopy). Typically XAS is measured by detecting the intensity of an x-ray beam before and after it is transmitted through a sample. This approach provides information about bulk properties. However, one can also achieve excellent sensitivity to interfaces, buried layers and diluted impurities or dopants by detecting electrons or photons that are emitted from the sample due to secondary processes instead. Finally, one can employ the polarization dependence of the x-ray absorption process

6

Magnetic order and interfacial coupling in oxide thin films and heterostructures probed with soft x-ray dichroism  

SciTech Connect

The combination of novel magnetic properties induced by reduced dimensionality and strong magnetic interactions across interfaces leads to intriguing new properties in magnetic hetero- and nanostructures not observed in the constituent materials in bulk form. It is the careful optimization of the characteristics of the individual layers as well as the magnetic coupling across the interface that allows us to control the magnetic properties and tailor them for devices, e.g., in information storage and processing technology. Soft x-ray magnetic spectroscopies can make unique contributions to improving our understanding of complex magnetic nanostructures since these techniques provide elemental, valence- and site-symmetry specific information with high sensitivity and tunable probing depth. X-ray magnetic circular dichroism (XMCD) is sensitive to (unidirectional) ferromagnetic order, while x-ray magnetic linear dichroism (XMLD) can also detect (uniaxial) antiferromagnetic order. A crystalline electric field with cubic symmetry induces only a weak angular dependence in XMCD spectra [1] but can cause a very pronounced anisotropy in XMLD spectra [2]. Furthermore, non-magnetic sites with a distorted local cubic symmetry can give rise to an x-ray linear dichroism (XLD). In this presentation, we discuss how to distinguish between the individual contributions to soft x-ray dichroism spectra in order to extract the wealth of information about magnetic thin films, interfaces and hetero- and nanostructures contained in the data [3, 4, 5] We determined the magnetic structure of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO)/La{sub 0.7}Sr{sub 0.3}FeO{sub 3} (LSFO) superlattices with 6 unit cell thick sublayers using soft x-ray magnetic dichroism [5]. Circular dichroism was employed to study the characteristics of the ferromagnetic LSMO layer indicating a reduced magnetic ordering temperature of 200 K compared to the bulk value of 360 K. Linear dichroism is used to analyze the antiferromagnetic order in the LSFO layers which persists up to the bulk Neel temperature near 400 K. Our experiments clearly show that when the magnetization of the LSMO layer is aligned with a magnetic field, a torque is created on the Fe moments in the LSFO layer through exchange coupling at the interface realigning the Fe moments as well. Through comparison with theoretical calculations we are able to show that independent of the LSMO magnetization direction in the sample surface plane, the Fe moments are always oriented perpendicular to the Mn moments. This perpendicular alignment is due to the frustrated exchange coupling at the interface and the weak anisotropy in the thin LSFO layer. Revisiting previous XMLD studies of the Co/NiO(001) interface taking the impact of the crystal electric field on the XMLD into account for the first time, we show that NiO(001) exhibits a crystallographic and magnetic domain structure near the surface that is identical to that of the bulk. Upon Co deposition perpendicular coupling of Co and Ni moments is observed [2, 3] that persists even in the presence of uncompensated interface moments. We also measured the asphericity and the energy splitting of the 4f states in EuO thin films [4] - a material with fascinating properties and of technological importance for spintronics applications - using XMLD. Our measurements, which are confirmed by multiplet calculations, show that there is significant 4f anisotropy. This suggests that pinning of the f states by the local environment becomes feasible and can be tuned by external conditions, chemical doping, and strain for use in device applications. Moreover, we will discuss the impact of epitaxial strain on the magnetic properties and XMLD spectra of complex oxide thin films.

Arenholz, Elke; van der Laan, G.

2009-02-01T23:59:59.000Z

7

An analysis of the x-ray linear dichroism spectrum for NiO thin films grown on vicinal Ag(001)  

SciTech Connect

Antiferromagnetic (AFM) NiO thin films are grown epitaxially on vicinal Ag(118) substrate and investigated by x-ray linear dichroism (XLD). We find that the NiO AFM spin exhibits an in-plane spin reorientation transition from parallel to perpendicular to the step edges with increasing the NiO film thickness. In addition to the conventional L{sub 2} adsorption edge, x-ray linear dichroism (XLD) effect at the Ni L{sub 3} adsorption edge is also measured and analyzed. The result identifies a small energy shift of the L{sub 3} peak. Temperature-dependent measurement confirms that the observed XLD effect in this system at the normal incidence of the x-rays originates entirely from the NiO magnetic ordering.

Wu, Y.Z.; Zhao, Y.; Arenholz, E.; Young, A.T.; Sinkovic, B.; Qiu, Z.Q.

2008-05-10T23:59:59.000Z

8

Mechanical design and analysis of an eight-pole superconducting vector magnet for soft x-ray magnetic dichroism measurements  

Science Conference Proceedings (OSTI)

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.

Arbelaez, D.; Black, A.; Prestemon, S.O.; Wang, S.; Chen, J.; Arenholz, E.

2010-01-13T23:59:59.000Z

9

X-ray absorption and magnetic circular dichroism studies of Co2FeAl in magnetic tunnel junctions  

SciTech Connect

The bulk magnetic moment and the element specific magnetic moment of Co{sub 2}FeAl thin films were examined as a function of annealing temperature by alternating gradient magnetometer (AGM) and X-ray absorption spectroscopy (XAS)/X-ray magnetic circular dichroism (XMCD), respectively. A high magnetic moment can be achieved for all annealing temperatures and the predicted bulk and interface magnetic moment of about 5 {tilde A}{sub B} are reached via heating. We will also present tunnel magnetoresistance (TMR) values of up to 153% at room temperature and 260% at 13 K for MgO based magnetic tunnel junctions (MTJs) with Co{sub 2}FeAl and Co-Fe electrodes.

Ebke, D.; Kugler, Z.; Thomas, P.; Schebaum, O.; Schafers, M.; Nissen, D.; Schmalhorst, J.; Hutten, A.; Arenholz, E.; Thomas, A.

2010-01-11T23:59:59.000Z

10

Remediation of Cr(VI) by biogenic magnetic nanoparticles: An x-ray magnetic circular dichroism study  

SciTech Connect

Biologically synthesized magnetite (Fe{sub 3}O{sub 4}) nanoparticles are studied using x-ray absorption and x-ray magnetic circular dichroism following exposure to hexavalent Cr solution. By examining their magnetic state, Cr cations are shown to exist in trivalent form on octahedral sites within the magnetite spinel surface. The possibility of reducing toxic Cr(VI) into a stable, non-toxic form, such as a Cr{sup 3+}-spinel layer, makes biogenic magnetite nanoparticles an attractive candidate for Cr remediation.

Telling, N. D.; Coker, V. S.; Cutting, R. S.; van der Laan, G.; Pearce, C. I.; Pattrick, R. A. D.; Arenholz, E.; Lloyd, J. R.

2009-09-04T23:59:59.000Z

11

Spin polarization and magnetic dichroism in core-level photoemission from ferromagnets  

Science Conference Proceedings (OSTI)

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.

Menchero, J.G. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States)

1997-05-01T23:59:59.000Z

12

End station for nanoscale magnetic materials study: Combination of scanning tunneling microscopy and soft X-ray magnetic circular dichroism spectroscopy  

SciTech Connect

We have constructed an end station for nanoscale magnetic materials study at the soft X-ray beamline HiSOR BL-14 at Hiroshima Synchrotron Radiation Center. An ultrahigh-vacuum scanning tunneling microscope (STM) was installed for an in situ characterization of nanoscale magnetic materials in combination with soft X-ray magnetic circular dichroism (XMCD) spectroscopy experiment. The STM was connected to the XMCD experimental station via damper bellows to isolate it from environmental vibrations, thus achieving efficient spatial resolution for observing Si(111) surface at atomic resolution. We performed an in situ experiment with STM and XMCD spectroscopy on Co nanoclusters on an Au(111) surface and explored its practical application to investigate magnetic properties for well-characterized nanoscale magnetic materials.

Ueno, Tetsuro; Sawada, Masahiro; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan); Kishimizu, Yusuke; Kimura, Akio [Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan); Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan)

2012-12-15T23:59:59.000Z

13

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (Extended Search)

Linear Collider Final Focus Magnet Construction Linear Collider Final Focus Magnet Construction The final focus magnets for the International Linear Collider require very small quadrupoles be placed within the detector background field for both the entrance and exit beams. The use of superconducting magnets for this function provide solutions to several problems confronting the machine designers. One constraint is the operation within the 3 tesla detector field. The direct wind magnets are capable of operation without the use of magnetic materials in their construction, making them ideal for compact focussing solutions within detectors. The second constraint is the small physical size dictated by the crossing angle of the beams and proximity to the IR within the detector solenoid. The Direct Wind design does not require a collar to withstand Lorentz

14

Magnetocrystalline Anisotropy of Magnetic Grains in Co80Pt20:Oxide Thin Films Probed by X-ray Magnetic Circular Dichroism  

SciTech Connect

Using angle-dependent x-ray magnetic circular dichroism, we have measured magnetic hysteresis loops at the Co L2,3 edges of oxide-doped Co80Pt20 thin films. The magnetocrystalline anisotropy energy (MAE) of the Co atoms, which is the main source of the magnetocrystalline anisotropy of the CoPt magnetic grains, has been determined directly from these element-specific hysteresis loops. When the oxide volume fraction (OVF) is increased from 16.6% to 20.7%, the Co MAE has been found to decrease from 0.117 meV/atom to 0.076 meV/atom. While a larger OVF helps one to achieve a smaller grain size, it reduces the magnetocrystalline anisotropy, as demonstrated unambiguously from the direct Co MAE measurements. Our results suggest that those Co80Pt20:oxide films with an OVF between 19.1% and 20.7% are suitable candidates for high-density magnetic recording.

Zhang, W.; Morton, S. A.; Wong, P. K. J.; Arenholz, E.; Lu, B.; Cheng, T. Y.; Xu, Y. B.; Laan, G. van der; Hu, X.F

2011-01-12T23:59:59.000Z

15

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (Extended Search)

Six Layer Quadrupole Six Layer Quadrupole The incoming beam final quad for the linear collider 20 mr option requires a gradient of 140 T/m within a solenoid of 3 Tesla. To meet this goal, a design using 6 around 1 cable bonded to a one inch diameter tube was used. The magnet design required 6 layers of this cable. Two layers were bonded at a time, with S-glass compression wrap every two layers. Final cold testing results were very good, with only two training quenches before reaching short sample. Initial test results at a glance: Background Field Tesla Temp Kelvin Gradient T/m 3 4.3 158 4 4.22 139 5 4.22 134 6 3 137 This data scales to 232 Tesla/meter at 1.9 Kelvin in a 3 Tesla background field. Present field requirements for the 20 mr IR represents 60% of the magnet capability, a comfortable margin. Indeed, even at 4.3 Kelvin in a 3

16

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

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.

Coffey, Howard T. (Darien, IL)

1993-01-01T23:59:59.000Z

17

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

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.

Coffey, H.T.

1993-10-19T23:59:59.000Z

18

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

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.

Coffey, H.T.

1992-12-31T23:59:59.000Z

19

Novel Approach to Linear Accelerator Superconducting Magnet System  

SciTech Connect

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.

Kashikhin, Vladimir; /Fermilab

2011-11-28T23:59:59.000Z

20

A low-power-extended-linear-range magnetic levitator  

E-Print Network (OSTI)

In this thesis, I designed and built analog circuits to extend the linear range of a magnetic levitator. Analog Devices AD633 multipliers are used to implement nonlinear terms which compensate for the electromagnet and ...

Johnson, Rayal St. Patrick

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Cryogen free superconducting splittable quadrupole magnet for linear accelerators  

SciTech Connect

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.

Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

2011-09-01T23:59:59.000Z

22

An Energy-Stabilized Varied-Line-Space-Monochromator UndulatorBeam Line for PEEM Illumination and Magnetic Circular Dichroism  

Science Conference Proceedings (OSTI)

A new undulator beam line has been built and commissioned at the Advanced Light Source for illumination of the PEEM3 microscope. The beam line delivers high flux beams over an energy range from C1s through the transition metals to include the M edges of the magnetic rare earth elements. We present details of the optical design, and data on the performance of the zero-order tracking of the photon energy.

Warwick, Tony; McKinney, Wayne; Domning, Ed; Doran, Andrew; Padmore, Howard

2006-06-01T23:59:59.000Z

23

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (Extended Search)

Two Layer Quadrupole Shielding Coil Two Layer Quadrupole Shielding Coil Near the interaction region if the ILC, the exit beam by design, is very close to the final focus quads, and is sensitive to the external field of the quads. To eliminate this effect and prevent disruption of the exiting beams, a two layer shielding quadrupole has been designed and wound. For simplicity as well as efficiency, the transfer function of this coilset has been designed to allow series connection of the focus quad with this outer shield coilset. The completed magnet will be finished with G-10 fillers, voltage taps and heaters will be added, blue epoxy filling for all interstitial spaces, and then the magnet will be wrapped with glass cloth and fiberglass roving, then cured. Once cured, this magnet will be capable of full power operation

24

Adaptive friction compensation for permanent magnet linear synchronous motor  

Science Conference Proceedings (OSTI)

The paper discussed an adaptive friction compensation scheme based on Coulomb friction and a parameter identifier. The model reference adaptive system based on Coulomb friction was designed to compensate the friction on-line. The designed model reference ... Keywords: friction compensation, model reference adaptive control, parameter identification, permanent magnet linear synchronous motor (PMLSM)

Wang Li-Mei; Wu Lin

2009-06-01T23:59:59.000Z

25

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (Extended Search)

Single Strand Superconductor Windings Single Strand Superconductor Windings Initial direct wind quad coils were constructed using 13 mil diameter single strand wire. This wire provides the smallest coil patterns possible, with quad coils wound easily onto .75 inch (19mm) diameter support tubes. The 13mil diameter superconductor gives the smallest coils possible, the penalty being higher inductance and smaller transfer function, but allowing lower operational currents. long model magnet Figure 1 shows the first one foot long model magnet constructed using the 11 axis ultrasonic wiring machine with 13 mil superconducting wire, the same wire previously used for the 472 RHIC Corrector packages. Existing stock materials were used in the construction, and the coil pattern was not optimized for harmonics, but to put as many coil turns onto the tube as

26

X-ray magnetic circular dichroism of ferromagnetic Co{sub 4}N epitaxial films on SrTiO{sub 3}(001) substrates grown by molecular beam epitaxy  

Science Conference Proceedings (OSTI)

5-nm thick Co{sub 4}N layers capped with 3-nm thick Au layers were grown epitaxially on SrTiO{sub 3}(001) substrates by molecular beam epitaxy using solid Co and a radio-frequency NH{sub 3} plasma. Spin and orbital magnetic moments of the Co{sub 4}N layers were estimated using x-ray magnetic circular dichroism (XMCD) measurements at 300 K. The site-averaged Co 3d spin magnetic moment is evaluated to be about 1.4 {mu}{sub B}, which is smaller than that predicted theoretically (1.58 {mu}{sub B}). The element-specific XMCD intensities for the Co L{sub 3} edge and N K edge show that the magnetic moment is induced at the N atoms.

Ito, Keita; Harada, Kazunori; Toko, Kaoru; Suemasu, Takashi [Institute of Applied Physics, University of Tsukuba, Ibaraki 305-8573 (Japan); Ye, Mao; Kimura, Akio [Graduate School of Science, Hiroshima University, Hiroshima 739-8526 (Japan); Takeda, Yukiharu; Saitoh, Yuji [Japan Atomic Energy Agency (JAEA), SPring-8, Hyogo 679-5198 (Japan); Akinaga, Hiro [National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8569 (Japan)

2011-12-19T23:59:59.000Z

27

An Observer-Based Design for Cogging Forces Cancellation in Permanent Magnet Linear Motors  

E-Print Network (OSTI)

An Observer-Based Design for Cogging Forces Cancellation in Permanent Magnet Linear Motors Jérémy magnet (PM) linear motors, in presence of spatially periodic forces, also known as cogging. Using cleanliness of operation and better resistance to wear and tear. Ironless motors feature two magnetic tracks

Paris-Sud XI, Université de

28

Performance evaluation of a permanent magnet brushless DC linear drive for high-speed machining using finite element analysis  

Science Conference Proceedings (OSTI)

Keywords: FEA, coupled magneto-thermal, electric field, electromagnetic, linear motor drives, magnetic field, static

George Abdou; William Tereshkovich

2000-05-01T23:59:59.000Z

29

13th International Conference on Magnetically Levitated Systems and Linear Drives  

Science Conference Proceedings (OSTI)

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.

Not Available

1993-09-01T23:59:59.000Z

30

Optimization of a dual acting, magnetically driven, linear actuator  

E-Print Network (OSTI)

In this study the geometry of a dual acting, magnetically driven, linear motion actuator will be optimized. This will be accomplished by modeling the system through a set of differential equations to be solved in Matlab. An ANSYS finite element program will be used to model the thermal response of the electrical coils so a maximum temperature can be found. These simulations will be part of a Matlab optimization routine. This routine will optimize the actuator's geometry by minimizing a cost function comprised of the floater displacement, the actuator weight, and the maximum coil temperature. Different simulations will be run, each with a unique set of operating parameters. These tests will be analyzed and an optimal configuration 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 that are found between the ECOREs and the floater will be replaced by a classical PID type controller. The effects that this PID controller has on the actuator response in reference to the design objectives will be noted and discussed. During the geometrical optimization, an optimal configuration was found that increases the stroke length of the actuator from approximately 1.01 mils to 2.24 mils. However, by implementing a PID control scheme and keeping the rubber pads, with a stiffness of 2854 lb/in, in the system, this stroke length can be increased to 30 mils. It is recommended that the geometry be changed to geometry found in iteration 53 of optimization trial 4 in conjunction with a PID control scheme. This best satisfies the design objectives.

Willerton, Justin Ryan

2002-01-01T23:59:59.000Z

31

Magnet-only loudspeaker motors: linear behavior theory vs. Nonlinear measurements  

E-Print Network (OSTI)

Magnet-only loudspeaker motors: linear behavior theory vs. Nonlinear measurements A. Novaka and B, the exclusive use of permanent magnets and the absence of iron can lead to uniform motor parameters (force [6] presented loudspeaker distortion reduction us- ing bonded magnet-only motors. Advantages

Paris-Sud XI, Université de

32

Correspondence between Electro-Magnetic Field and other Dark Energies in Non-linear Electrodynamics  

E-Print Network (OSTI)

In this work, we have considered the flat FRW model of the universe filled with electro-magnetic field. First, the Maxwell's electro-magnetic field in linear form has been discussed and after that the modified Lagrangian in non-linear form for accelerated universe has been considered. The corresponding energy density and pressure for non-linear electro-magnetic field have been calculated. We have found the condition such that the electro-magnetic field generates dark energy. The correspondence between the electro-magnetic field and the other dark energy candidates namely tachyonic field, DBI-essence, Chaplygin gas, hessence dark energy, k-essenece and dilaton dark energy have been investigated. We have also reconstructed the potential functions and the scalar fields in this scenario.

Maity, Sayani; Debnath, Ujjal

2011-01-01T23:59:59.000Z

33

Correspondence between Electro-Magnetic Field and other Dark Energies in Non-linear Electrodynamics  

E-Print Network (OSTI)

In this work, we have considered the flat FRW model of the universe filled with electro-magnetic field. First, the Maxwell's electro-magnetic field in linear form has been discussed and after that the modified Lagrangian in non-linear form for accelerated universe has been considered. The corresponding energy density and pressure for non-linear electro-magnetic field have been calculated. We have found the condition such that the electro-magnetic field generates dark energy. The correspondence between the electro-magnetic field and the other dark energy candidates namely tachyonic field, DBI-essence, Chaplygin gas, hessence dark energy, k-essenece and dilaton dark energy have been investigated. We have also reconstructed the potential functions and the scalar fields in this scenario.

Sayani Maity; Shuvendu Chakraborty; Ujjal Debnath

2011-04-12T23:59:59.000Z

34

A linear helicon plasma device with controllable magnetic field gradient  

Science Conference Proceedings (OSTI)

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.

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

35

Analysis and Design of a High Power Density Axial Flux Permanent Magnet Linear Synchronous Machine Used for Stirling System  

Science Conference Proceedings (OSTI)

a high power density axial flux permanent magnet linear synchronous machine and the stirling system will be introduced. This machine is a tubular axial flux permanent magnet machine. It comprises two parts: stator and mover. With the 2D finite-element ... Keywords: permanent magnet, stirling engine, linear motor

Ping Zheng; Xuhui Gan; Lin Li

2010-09-01T23:59:59.000Z

36

Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider  

Science Conference Proceedings (OSTI)

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 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0-20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micrometer during the 20% adjustment. In an effort to reduce estimated costs and increase reliability, several designs using hybrid permanent magnets have been developed. All magnets have iron poles and use either Samarium Cobalt or Neodymium Iron to provide the magnetic fields. Two prototypes use rotating rods containing permanent magnetic material to vary the gradient. Gradient changes of 20% and center shifts of less than 20 microns have been measured. These data are compared to an equivalent electromagnet prototype.

James T Volk et al.

2001-09-24T23:59:59.000Z

37

Design and optimization strategies for muscle-like direct-drive linear permanent-magnet motors  

Science Conference Proceedings (OSTI)

We report a new approach to the design of direct-drive linear permanent-magnet motors for use in general-purpose robotic actuation, with particular attention to applications in bird-scale flapping-wing robots. We show a simple, quantitative analytical ... Keywords: Actuator design, electric motors, muscle

Bryan P Ruddy; Ian W Hunter

2011-06-01T23:59:59.000Z

38

Design of Vertical Transportation System Driven by Permanent Magnet Linear Synchronous Motor Signal Acquisition  

Science Conference Proceedings (OSTI)

Permanent Magnet Linear Synchronous Motor(PMLSM) Vertical Transportation system is a new kind of ropeless hoisting system. In addition to the complications of dynamic state characteristic, the examination of some signals is also very difficult. In this ... Keywords: PMLSM, Signal Acquisition, Hardware Designs, Software

Wang Chang Li; Zhang You Dong; Zhao Liang

2012-08-01T23:59:59.000Z

39

Contribution of Eu 4f states to the magnetic anisotropy of EuO  

Science Conference Proceedings (OSTI)

Anisotropic x-ray magnetic linear dichroism (AXMLD) provides a novel element-, site-, shell-, and symmetry-selective techniques to study the magnetic anisotropy induced by a crystalline electric field. The weak Eu2+ M4,5 AXMLD observed in EuO(001) indicates that the Eu 4f states are not rotationally invariant and hence contribute weakly to the magnetic anisotropy of EuO. The results are contrasted with those obtained for 3d transition metal oxides.

Arenholz, E.; Schmehl, A.; Schlom, D.G.; van der Laan, G.

2008-09-11T23:59:59.000Z

40

FE Magnetic Field Analysis Simulation Models based Design, Development, Control and Testing of An Axial Flux Permanent Magnet Linear Oscillating Motor  

E-Print Network (OSTI)

Abstract- Development, finite element(FE) analysis of magnetic field distribution, performance, control and testing of a new axial flux permanent magnet linear oscillating motor (PMLOM) along with a suitable speed and thrust control technique is described in this paper. The PMLOM can perform precision oscillation task without exceeding the given limit on allowable average power dissipation. The use of new powerful permanent magnet materials such as Neodymium-Iron-Boron alloys can greatly improve the performance of electrical machines. Also its performance parameters, such as the force, current etc. are experimentally assessed. The objective of this paper is to determine the forces for aluminium mover embedded with rare earth permanent magnet experimentally and analytically through FEMM software and develop a microcontroller based IGBT Inverter for its control. Index Terms- Axial flux machine, finite element analysis, microcontroller based IGBT inverter, permanent magnet linear oscillating motor, rare earth permanent magnet. I.

Govindaraj T; Prof Dr; Ashoke K. Ganguli

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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41

Spin-polarized relativistic linear-muffin-tin-orbital method: Volume-dependent electronic structure and magnetic moment of plutonium  

Science Conference Proceedings (OSTI)

The linear-muffin-tin-orbital method is generalized to the case of relativistic and spin-polarized self-consistent band calculations. Our formalism is analogous to the standard orthogonal--linear-muffin-tin-orbital formalism, except that the potential functions and the potential parameters are now matrices. The method is used to perform density-functional calculations for fcc plutonium with different atomic volumes. The formation of spin and orbital magnetic moments, as well as the changes in the energy bands for volume changes corresponding to the {alpha}-{delta} transition, are investigated. The calculated magnetic moments agree quite well with the experimental ones.

Solovyev, I.V. (Institute of Chemistry, Ural Branch of U.S.S.R. Academy of Science, Sverdlovsk GSP-145, U.S.S.R. (SU)); Liechtenstein, A.I. (Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany (DE)); Gubanov, V.A. (Institute of Chemistry, Ural Branch of U.S.S.R. Academy of Science, Sverdlovsk GSP-145, U.S.S.R. (SU)); Antropov, V.P. (Institute of Metal Physics, Ural Branch of U.S.S.R. Academy of Science, Sverdlosk GSP-145, U.S.S.R. (SU)); Andersen, O.K. (Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany (DE))

1991-06-15T23:59:59.000Z

42

Magnetic Energy and Helicity Budgets in the Active-Region Solar Corona. I. Linear Force-Free Approximation  

E-Print Network (OSTI)

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.

Manolis K. Georgoulis; Barry J. Labonte

2005-01-01T23:59:59.000Z

43

Magnetic Energy and Helicity Budgets in the Active-Region Solar Corona. I. Linear Force-Free Approximation  

E-Print Network (OSTI)

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.

M. K. Georgoulis; Barry J. LaBonte

2007-06-27T23:59:59.000Z

44

Spin relaxation and linear-in-electric-field frequency shift in an arbitrary, time-independent magnetic field  

Science Conference Proceedings (OSTI)

A method is presented to calculate the spin relaxation times T{sub 1}, T{sub 2} due to a nonuniform magnetic field, and the linear-in-electric-field precession frequency shift {delta}{omega}{sub E} when an electric field is present, in the diffusion approximation for spins confined to a rectangular cell. It is found that the rectangular cell geometry admits of a general result for T{sub 1}, T{sub 2}, and {delta}{omega}{sub E} in terms of the spatial cosine-transform components of the magnetic field.

Clayton, Steven Michael [Los Alamos National Laboratory

2010-12-03T23:59:59.000Z

45

Determination of the Fe magnetic anisotropies and the CoO frozen spins in epitaxial CoO/Fe/Ag(001)  

SciTech Connect

CoO/Fe/Ag(001) films were grown epitaxially and studied by X-ray Magnetic Circular Dichroism (XMCD) and X-ray Magnetic Linear Dichroism (XMLD). After field cooling along the Fe[100] axis to 80 K, exchange bias, uniaxial anisotropy, and 4-fold anisotropy of the films were determined by hysteresis loop and XMCD measurements by rotating the Fe magnetization within the film plane. The CoO frozen spins were determined by XMLD measurement as a function of CoO thickness.We find that among the exchange bias, uniaxial anisotropy, and 4-fold anisotropy, only the uniaxial magnetic anisotropy follows thickness dependence of the CoO frozen spins.

Meng, J. Li, Y.; Park, J. S.; Jenkins, C. A.; Arenholz, E.; Scholl, A.; Tan, A.; Son, H.; Zhao, H. W.; Hwang, Chanyong; Qiu, Z. Q.

2011-04-28T23:59:59.000Z

46

SIMULTANEOUS MEASUREMENT OF CIRCULAR DICHROISM AND FLUORESCENCE POLARIZATION ANISOTROPY.  

Science Conference Proceedings (OSTI)

Circular dichroism and fluorescence polarization anisotropy are important tools for characterizing biomolecular systems. Both are used extensively in kinetic experiments involving stopped- or continuous flow systems as well as titrations and steady-state spectroscopy. This paper presents the theory for determining circular dichroism and fluorescence polarization anisotropy simultaneously, thus insuring the two parameters are recorded under exactly the same conditions and at exactly the same time in kinetic experiments. The approach to measuring circular dichroism is that used in almost all conventional dichrographs. Two arrangements for measuring fluorescence polarization anisotropy are described. One uses a single fluorescence detector and signal processing with a lock-in amplifier that is similar to the measurement of circular dichroism. The second approach uses classic ''T'' format detection optics, and thus can be used with conventional photon-counting detection electronics. Simple extensions permit the simultaneous measurement of the absorption and excitation intensity corrected fluorescence intensity.

SUTHERLAND,J.C.

2002-01-19T23:59:59.000Z

47

The effect of two-temperature post-shock accretion flow on the linear polarization pulse in magnetic cataclysmic variables  

E-Print Network (OSTI)

The temperatures of electrons and ions in the post-shock accretion region of a magnetic cataclysmic variable (mCV) will be equal at sufficiently high mass flow rates or for sufficiently weak magnetic fields. At lower mass flow rates or in stronger magnetic fields, efficient cyclotron cooling will cool the electrons faster than the electrons can cool the ions and a two-temperature flow will result. Here we investigate the differences in polarized radiation expected from mCV post-shock accretion columns modeled with one- and two-temperature hydrodynamics. In an mCV model with one accretion region, a magnetic field >~30 MG and a specific mass flow rate of ~0.5 g/cm/cm/s, along with a relatively generic geometric orientation of the system, we find that in the ultraviolet either a single linear polarization pulse per binary orbit or two pulses per binary orbit can be expected, depending on the accretion column hydrodynamic structure (one- or two-temperature) modeled. Under conditions where the physical flow is two...

Sarty, Gordon E; Wu, Kinwah

2008-01-01T23:59:59.000Z

48

High Resolution Millimeter-Wave Mapping of Linearly Polarized Dust Emission: Magnetic Field Structure in Orion  

E-Print Network (OSTI)

We present 1.3 and 3.3 mm polarization maps of Orion-KL obtained with the BIMA array at approximately 4 arcsec resolution. Thermal emission from magnetically aligned dust grains produces the polarization. Along the Orion ``ridge'' the polarization position angle varies smoothly from about 10 degrees to 40 degrees, in agreement with previous lower resolution maps. In a small region south of the Orion ``hot core,'' however, the position angle changes by 90 degrees. This abrupt change in polarization direction is not necessarily the signpost of a twisted magnetic field. Rather, in this localized region processes other than the usual Davis-Greenstein mechanism might align the dust grains with their long axes parallel with the field, orthogonal to their normal orientation.

R. Rao; R. M. Crutcher; R. L. Plambeck; M. C. H. Wright

1998-05-21T23:59:59.000Z

49

Circular dichroism: A general theory based on quantum electrodynamics  

Science Conference Proceedings (OSTI)

A theory of circular dichroism is developed through a direct calculation of the absorption rates for circularly polarized light on molecules. From this a differential rate as between left and right circularly polarized light is calculated. This is immediately related to the experimental data on circular dichroism. When the calculations are restricted to the dipole approximation we reproduce the rotatory strength in the form of a differential Einstein B coefficient. Higher moments are considered in detail and their effects analyzed for both the locked?in situation and the case of randomly oriented molecular absorbers. A general expression is obtained for the differential absorption rate.

E. A. Power; T. Thirunamachandran

1974-01-01T23:59:59.000Z

50

Observational Study of Higher Dimensional Magnetic Universe in Non-linear Electrodynamics  

E-Print Network (OSTI)

In this work, we have considered the flat FRW model of the universe in $(n+2)$-dimensions filled with the dark matter and the magnetic field. We present the Hubble parameter in terms of the observable parameters $\\Omega_{m0}$ and $H_{0}$ with the redshift $z$ and the other parameters like $B_{0},\\omega, \\mu_{0},\\delta,n,w_{m}$. The natures of magnetic field $B$, deceleration parameter $q$ and $Om$ diagnostic have also been analyzed for accelerating expansion of the universe. From Stern data set (12 points), we have obtained the bounds of the arbitrary parameters by minimizing the $\\chi^{2}$ test. The best-fit values of the parameters are obtained by 66%, 90% and 99% confidence levels. Now to find the bounds of the parameters ($B_{0},\\omega$) and to draw the statistical confidence contour, we fixed four parameters $\\mu_{0},\\delta,n,w_{m}$. Here the parameter $n$ determines the higher dimensions and we perform comparative study between three cases : 4D $(n=2)$, 5D $(n=3)$ and 6D $(n=4)$ respectively. Next due to joint analysis with BAO observation, we have also obtained the bounds of the parameters ($B_{0},\\omega$) by fixing other parameters $\\mu_{0},\\delta,n,w_{m}$ for 4D, 5D and 6D. The best fit of distance modulus for our theoretical model and the Supernova Type Ia Union2 sample are drawn for different dimensions.

Chayan Ranjit; Shuvendu Chakraborty; Ujjal Debnath

2013-04-04T23:59:59.000Z

51

Electromagnetic momentum and the energy-momentum tensor in a linear medium with magnetic and dielectric properties  

E-Print Network (OSTI)

The well-defined total energy and total momentum in a thermodynamically closed system with complete equations of motion is 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. We discuss the uniqueness conditions for the elements of the energy-momentum tensor that are based on the conservation of total energy and total momentum. We write the tensor continuity equation and derive the continuity equations for energy and momentum from the total energy-momentum tensor. The equations of motion for the fields are recast in a form that is consistent with the energy-momentum tensor formalism. The Abraham-Minkowski momentum controversy is resolved in favor of a total momentum that is conserved in a closed system with complete equations of motion.

Crenshaw, Michael E

2013-01-01T23:59:59.000Z

52

An Automated Magnet Positioning System For Use in the Next Linear Collider  

SciTech Connect

The Next Linear Collider (NLC) is conceived as the world?¢????s most powerful electron-positron particle accelerator. Throughout the NLC, the beam itself will be used to measure errors in the positions of the lattice elements. This beam-based alignment strategy is an essential element of the NLC?¢????s design and precision adjustment systems have been identified as a critical enabling technology. Square One proposes a new type of precision manipulator that could be adapted for applications throughout the accelerator. As envisioned, this ?¢????Tri-Sphere?¢??? Adjustment System will possess up to six, non-redundant degrees of freedom, be capable of sub-micron resolutions and have ultimate load capacities in excess of 10,000 kg. The system will accommodate thermal expansions and contractions of the objects being supported and can be either motorized or manually actuated. Phase I development tasks will include detailed manipulator design, solution of the associated kinematic equations of motion and evaluation of actuators, gear reducers and transmission systems. The Phase I effort will culminate in the fabrication and full evaluation of a system prototype. A successfully developed Tri-Sphere manipulator could also be used to actively position critical fusion optics, adjust communication dishes or perform parts handling tasks in harsh manufacturing environments.

Viola, Robert J.

2006-02-21T23:59:59.000Z

53

LINEAR ACCELERATOR  

DOE Patents (OSTI)

Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

Christofilos, N.C.; Polk, I.J.

1959-02-17T23:59:59.000Z

54

Studies of the magnetic structure at the ferromagnet - antiferromagnet interface  

SciTech Connect

Antiferromagnetic layers are a scientifically challenging component in magneto-electronic devices such as magnetic sensors in hard disk heads, or magnetic RAM elements. In this paper we show that photo-electron emission microscopy (PEEM) is capable of determining the magnetic structure at the interface of ferromagnets and antiferromagnets with high spatial resolution (down to 20 nm). Dichroism effects at the L edges of the magnetic 3d transition metals, using circularly or linearly polarized soft x-rays from a synchrotron source, give rise to a magnetic image contrast. Images, acquired with the PEEM2 experiment at the Advanced Light Source, show magnetic contrast for antiferromagnetic LaFeO{sub 3}, microscopically resolving the magnetic domain structure in an antiferromagnetically ordered thin film for the first time. Magnetic coupling between LaFeO{sub 3} and an adjacent Co layer results in a complete correlation of their magnetic domain structures. From field dependent measurements a unidirectional anisotropy resulting in a local exchange bias of up to 30 Oe in single domains could be deduced. The elemental specificity and the quantitative magnetic sensitivity render PEEM a perfect tool to study magnetic coupling effects in multi-layered thin film samples.

Scholl, A.; Nolting, F.; Stohr, J.; Luning, J.; Seo, J.W.; Locquet, J.-P.; Anders, S.; Ohldag, H.; Padmore, H.A.

2001-01-02T23:59:59.000Z

55

IEEE TRANSACTIONS ON MAGNETICS, VOL. 47, NO. 12, DECEMBER 2011 4809 A Linear Doubly Salient Permanent-Magnet Motor With Modular and  

E-Print Network (OSTI)

Permanent-Magnet Motor With Modular and Complementary Structure Ruiwu Cao1;2, Ming Cheng1, Chris Mi2, Wei permanent magnet (LDSPM) motor is particularly suitable for long stator applications due to its simple, and higher magnet utilization factor than the existing one. Index Terms--Double salient motor, finite

Mi, Chunting "Chris"

56

Effects of magnetic non-linearities on a stored proton beam and their implications for superconducting storage rings  

SciTech Connect

A nonlinear lens may be used to study the effect of high-order multipolar field imperfections on a stored proton beam. Such a nonlinear lens is particulary suitable to simulate field imperfections of the types encountered in coil dominated superconducting magnets. We have studied experimentally at the SPS the effect of high order (5th and 8th) single isolated resonances driven by the nonlinear lens. The width of these resonances is of the order one expects to be caused by field errors in superconducting magnets of the SSC type. The experiment shows that, in absence of tune modulation, these resonances are harmless. Slow crossings of the resonance, on the other hand, have destructive effects on the beam, much more so than fast crossings caused by synchrotron oscillations. In the design of future storage rings, sources of low-frequency tune modulation should be avoided as a way to reduce the harmful effects of high order multipolar field imperfection.

Cornacchia, M.; Evans, L.

1985-06-01T23:59:59.000Z

57

Mesoscopic Magnetic/Semiconductor Heterostructures  

Science Conference Proceedings (OSTI)

We report the experimental results of Fe and Fe3O4 nanostructures on GaAs(100) surfaces and hybrid Ferromagnetic/Semiconductor/Ferromagnetic (FM/SC/FM) spintronic devices. Element specific x-ray magnetic circular dichroism (XMCD) ... Keywords: Epitaxial ferromagnetic thin film, ferromagnetic/semiconductor hybrid structures, spintronics

Yong Bing Xu; E. Ahmad; Yong Xiong Lu; J. S. Claydon; Ya Zhai; G. van der Laan

2006-09-01T23:59:59.000Z

58

Linear electric field frequency shift (important for next generation electric dipole moment searches) induced in confined gases by a magnetic field gradient  

E-Print Network (OSTI)

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.

Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux

2006-07-17T23:59:59.000Z

59

-Interface effects on the magnetic moment of Co and Cu in CoCu granular alloys  

SciTech Connect

We report on x-ray magnetic circular dichroism experiments performed on Co{sub 5}Cu{sub 95} annealed granular alloys with giant magnetoresistance. Results on the Co-L{sub 2,3} edge evidence a direct correlation between the Co orbital and spin magnetic moment and the Co clusters interfacial roughness. On the other hand, we have found dichroism on the Cu-L{sub 2,3} edge, revealing an induced magnetic polarization of the Cu interfacial atoms. The magnetic moment of the Cu atoms is mainly of spin character and is ferromagnetically coupled with the Co magnetic moment.

Garcia Prieto, A.; Fdez-Gubieda, M.L.; Chaboy, J.; Laguna-Marco, M.A.; Muro, T.; Nakamura, T. [Departamento de Electricidad y Electronica, Universidad del Pais Vasco (UPV/EHU), Apartado 644, 48080 Bilbao (Spain); Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, 50009 Zaragoza (Spain); CITIMAC, Universidad de Cantabria, Avenida de los Castros s/n, 39005 Santander (Spain); Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148 (Japan)

2005-12-01T23:59:59.000Z

60

Protein Circular Dichroism Data Bank (PCDDB): Data Bank and Website Design  

E-Print Network (OSTI)

;5:567­571. 9. Wien F, Wallace BA. Calcium fluoride micro cells for synchrotron radiation circular dichroism modeling and drug design pro- gram. J Mol Graphics 1990;8:52­56. 7. Guideline Q6B, International Conference

Janes, Bob

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Optical Dichroism by Nonlinear Excitations in Graphene Nanoribbons  

E-Print Network (OSTI)

The honeycomb carbon structure of graphene and nanotubes has a dynamics which can give rise to a spectrum. This can be excited via the interaction with an external electromagnetic field. In this work, non-linear waves on graphene and nanotubes associated with the carbon structure are investigated using a gauge model. Typical energies are estimated and there scaling with the nanoribbon width investigated. Furthermore, the soliton-photon interaction depends on the incident photon polarization. In particular, we find that the nanoribbon is transparent when the polarization is along the largest length. Relying on the scaling with the width, we suggest a way to experimentally identify the soliton waves in nanoribbons.

C. E. Cordeiro; A. Delfino; T. Frederico; O. Oliveira; W. de Paula

2013-02-15T23:59:59.000Z

62

magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

I I Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

63

Magnetic soft x-ray microscopy-imaging fast spin dynamics inmagnetic nanostructures  

SciTech Connect

Magnetic soft X-ray microscopy combines 15nm spatial resolution with 70ps time resolution and elemental sensitivity. Fresnel zone plates are used as X-ray optics and X-ray magnetic circular dichroism serves as magnetic contrast mechanism. Thus scientifically interesting and technologically relevant low dimensional nanomagnetic systems can be imaged at fundamental length and ultrafast time scales in a unique way. Studies include magnetization reversal in magnetic multilayers, nanopatterned systems, vortex dynamics in nanoelements and spin current induced phenomena.

Fischer, Peter; Kim, Dong-Hyun; Mesler, Brooke L.; Chao, Weilun; Sakdinawat, Anne E.; Anderson, Erik H.

2007-06-01T23:59:59.000Z

64

Equilibrium magnetic states in individual hemispherical permalloy caps  

Science Conference Proceedings (OSTI)

The magnetization distributions in individual soft magnetic permalloy caps on non-magnetic spherical particles with sizes ranging from 50 to 800 nm are investigated. We experimentally visualize the magnetic structures at the resolution limit of the x-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM). By analyzing the so-called tail contrast in XMCD-PEEM, the spatial resolution is significantly enhanced, which allowed us to explore magnetic vortices and their displacement on curved surfaces. Furthermore, cap nanostructures are modeled as extruded hemispheres to determine theoretically the phase diagram of equilibrium magnetic states. The calculated phase diagram agrees well with the experimental observations.

Streubel, Robert; Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany); Kravchuk, Volodymyr P.; Gaididei, Yuri [Bogolyubov Institute for Theoretical Physics, 03143 Kiev (Ukraine); Sheka, Denis D. [Radiophysics Faculty, Taras Shevchenko National University of Kiev, 01601 Kiev (Ukraine); Makarov, Denys [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Kronast, Florian [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, 12489 Berlin (Germany)

2012-09-24T23:59:59.000Z

65

Remote Sensing of Chromospheric Magnetic Fields via the Hanle and Zeeman Effects  

E-Print Network (OSTI)

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.

J. Trujillo Bueno; R. Manso Sainz

2007-11-16T23:59:59.000Z

66

Characteristics of Graphitic Films for Carbon Based Magnetism and Electronics  

E-Print Network (OSTI)

solenoid magnet up to 14 T. VSM linear motor module (R) andsolenoid magnet up to 14 T. VSM linear motor module (R) and

Hong, Jeongmin

2009-01-01T23:59:59.000Z

67

An Investigation of the Effects of a Driven Plasma Rotation on Fluctuation in a Magnetized Linear Plasma Source. Final Technical Report  

SciTech Connect

The rotation of a plasma is one of the most fundamental global modes of plasma behavior. It is the zeroth order plasma response to a transverse electric field. In its simplest kinetic form, the so-called E x B drift (here, E is the electric field vector and B is the magnetic field vector), both the ions and the electrons will undergo a drift in the same direction. This motion is considered a universal mode of a plasma since the mechanism of the E x B drift is, to zero-order, independent of both the mass and the charge of the particles.

Thomas, E.

2004-05-18T23:59:59.000Z

68

Detailed discussion of a linear electric field frequency shift (important for next generation) electric dipole moment searches) induced in confined gases by a magnetic field gradient: Implications for electric dipole moment experiments (II)  

E-Print Network (OSTI)

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.

A. L. Barabanov; R. Golub; S. K. Lamoreaux

2005-12-08T23:59:59.000Z

69

Linear Quadratic  

E-Print Network (OSTI)

The proposal of Reshef et. al. (MIC) is an interesting new approach for discovering non-linear dependencies among pairs of measurements in exploratory data mining. However, it has a potentially serious drawback. The authors laud the fact that MIC has no preference for some alternatives over others, but as the authors know, there is no free lunch in Statistics: tests which strive to have high power against all alternatives can have low power in many important situations. To investigate this, we ran simulations to compare the power of MIC to that of standard Pearson correlation and distance correlation (dcor) Szkely & Rizzo (2009). We simulated pairs of variables with different relationships (most of which were considered by the Reshef et. al.), but with varying levels of noise added. To determine proper cutoffs for testing the independence hypothesis, we simulated independent data with the appropriate marginals. As one can see from the Figure, MIC has lower power than dcor, in every case except the somewhat pathological

Noah Simon; Robert Tibshirani; Noah Simon; Robert Tibshirani

2011-01-01T23:59:59.000Z

70

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

Notes Notes LCC - 0038 29/04/00 CBP Tech Note - 234 Transverse Field Profile of the NLC Damping Rings Electromagnet Wiggler 29 April 2000 17 J. Corlett and S. Marks Lawrence Berkeley National Laboratory M. C. Ross Stanford Linear Accelerator Center Stanford, CA Abstract: The primary effort for damping ring wiggler studies has been to develop a credible radiation hard electromagnet wiggler conceptual design that meets NLC main electron and positron damping ring physics requirements [1]. Based upon an early assessment of requirements, a hybrid magnet similar to existing designs satisfies basic requirements. However, radiation damage is potentially a serious problem for the Nd-Fe-B permanent magnet material, and cost remains an issue for samarium cobalt magnets. Superconducting magnet designs have not been

71

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor when it 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.

Parsons, W.M.

1991-03-19T23:59:59.000Z

72

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

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.

Parsons, W.M.

1992-12-29T23:59:59.000Z

73

Nonferromagnetic linear variable differential transformer  

DOE Patents (OSTI)

A nonferromagnetic linear variable differential transformer for accurately measuring mechanical displacements in the presence of high magnetic fields is provided. The device utilizes a movable primary coil inside a fixed secondary coil that consists of two series-opposed windings. Operation is such that the secondary output voltage is maintained in phase (depending on polarity) with the primary voltage. The transducer is well-suited to long cable runs and is useful for measuring small displacements in the presence of high or alternating magnetic fields.

Ellis, James F. (Powell, TN); Walstrom, Peter L. (Oak Ridge, TN)

1977-06-14T23:59:59.000Z

74

Linearized gyro-kinetic equation  

SciTech Connect

An ordering of the linearized Fokker-Planck equation is performed in which gyroradius corrections are retained to lowest order and the radial dependence appropriate for sheared magnetic fields is treated without resorting to a WKB technique. This description is shown to be necessary to obtain the proper radial dependence when the product of the poloidal wavenumber and the gyroradius is large (k rho much greater than 1). A like particle collision operator valid for arbitrary k rho also has been derived. In addition, neoclassical, drift, finite $beta$ (plasma pressure/magnetic pressure), and unperturbed toroidal electric field modifications are treated. (auth)

Catto, P.J.; Tsang, K.T.

1976-01-01T23:59:59.000Z

75

XMCD  

NLE Websites -- All DOE Office Websites (Extended Search)

optics, the term "dichroism" refers to changes in the absorption of optics, the term "dichroism" refers to changes in the absorption of polarized light on passing through a material in two different directions. Since materials typically absorb one color of white light preferentially, the material appears with two different colors for the two light directions - it is di- (two-) c hroic (colored). Today, the term dichroism is used more generally to reflect the dependence of photon absorption of a material on polarization. The origin of the dichroism effect can be anisotropies in the charge or the spin in the material. In the latter case we speak of magnetic dichroism. Here we briefly discuss the principles and applications of magnetic dichroism techniques in the x-ray region, the X-Ray Magnetic Circular Dichroism (XMCD) and X-Ray Magnetic Linear Dichroism (XML D)

76

Deflection gating for time-resolved x-ray magnetic circular dichroism-photoemission electron microscopy using synchrotron radiation  

SciTech Connect

In this paper, we present a newly developed gating technique for a time-resolving photoemission microscope. The technique makes use of an electrostatic deflector within the microscope's electron optical system for fast switching between two electron-optical paths, one of which is used for imaging, while the other is blocked by an aperture stop. The system can be operated with a switching time of 20 ns and shows superior dark current rejection. We report on the application of this new gating technique to exploit the time structure in the injection bunch pattern of the synchrotron radiation source BESSY II at Helmholtz-Zentrum Berlin for time-resolved measurements in the picosecond regime.

Wiemann, C.; Kaiser, A. M.; Cramm, S. [Peter Gruenberg Institut PGI-6 'Electronic Properties', Research Centre Juelich, D-52425 Juelich (Germany); Schneider, C. M. [Peter Gruenberg Institut PGI-6 'Electronic Properties', Research Centre Juelich, D-52425 Juelich (Germany); Fakultaet fuer Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, D-47048 Duisburg (Germany)

2012-06-15T23:59:59.000Z

77

Linear Thermite Charge  

The Linear Thermite Charge (LTC) is designed to rapidly cut through concrete and steel structural components by using extremely high temperature thermite reactions jetted through a linear nozzle.

78

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host such as GaAs, ZnO, or GaN. The interaction among these spins leads to ferromagnetic order at low temperatures, which is necessary to create spin-polarized carriers. A research team working at ALS Beamline 4.0.2 and European Synchrotron Radiation Facility Beamline ID8 made a big leap forward in clarifying the microscopic picture of magnetism and anisotropy in Mn-doped GaAs by resolving localized and hybridized d states using angle-dependent x-ray magnetic circular dichroism (XMCD) measurements.

79

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electronic Structure and Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Wednesday, 29 November 2006 00:00 The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host such as GaAs, ZnO, or GaN. The interaction among these spins leads to ferromagnetic order at low temperatures, which is necessary to create spin-polarized carriers. A research team working at ALS Beamline 4.0.2 and European Synchrotron Radiation Facility Beamline ID8 made a big leap forward in clarifying the microscopic picture of magnetism and anisotropy in Mn-doped GaAs by resolving localized and hybridized d states using angle-dependent x-ray magnetic circular dichroism (XMCD) measurements.

80

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host such as GaAs, ZnO, or GaN. The interaction among these spins leads to ferromagnetic order at low temperatures, which is necessary to create spin-polarized carriers. A research team working at ALS Beamline 4.0.2 and European Synchrotron Radiation Facility Beamline ID8 made a big leap forward in clarifying the microscopic picture of magnetism and anisotropy in Mn-doped GaAs by resolving localized and hybridized d states using angle-dependent x-ray magnetic circular dichroism (XMCD) measurements.

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Cable Winding Tests Superconducting Cable Winding Tests To increase the transfer function, a 6 around 1 cable was next used. This cable is more efficient because it allows the packing of more conductor within the volume surrounding the support tube. This also lowers the inductance of the coil, making quench protection easier, but requires a higher operating current. Traded off is the minimum radius of curvature that can be tolerated by the bonding process as well as the insulation integrity. For this test, the first layer was designed for a length of 8 inches, and the second layer is 6 inches long. The lengths were chosen to allow inspection of the different features which were designed in. The pole spacers on the first layer for this test were chosen to be solid copper wire, instead of the standard G-10 spacer. The copper allows for a

82

IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 27, NO. 2, JUNE 2012 489 Modeling of a Complementary and Modular Linear  

E-Print Network (OSTI)

and Modular Linear Flux-Switching Permanent Magnet Motor for Urban Rail Transit Applications Ruiwu Cao-switching permanent magnet (MLFSPM) motor is investi- gated, in which both the magnets and armature windings incorporates the high power density of a linear permanent magnet synchronous motor and the simple structure

Mi, Chunting "Chris"

83

Thermolysis of (1R,2R)-1,2-dideuteriocyclobutane. An application of vibrational circular dichroism to kinetic analysis  

SciTech Connect

The relative rates of geometric isomerization to racemization have been studied for the title compound by using a combination of infrared (IR) and vibrational circular dichroism (VCD) spectroscopies, respectively. The results are interpreted with a kinetic and mechanistic scheme which parallels that used by Berson, Pedersen, and Carpenter on a similar study of chiral cyclopropane-d/sub 2/ thermolysis. Relative rates of isomerization to stereomutation of 1.5 +/- 0.4 were obtained which can be interpreted to be consistent with a mechanism best described by random methylene rotation in tetramethylene-d/sub 2/. This is the first application of VCD to kinetic analysis, and the advantages of IR techniques over the more usually employed UV spectroscopies to this type of basic mechanistic problem are illustrated.

Chickos, J.S.; Annamalai, A.; Keiderling, T.A.

1986-07-23T23:59:59.000Z

84

Soft x-ray circular dichroism and scattering using a modulated elliptically polarizing wiggler and double synchronous detection  

Science Conference Proceedings (OSTI)

We have constructed an experimental station (beamline) at the National Synchrotron Light Source to measure circular dichroism (CD) using soft x-rays (250 {le} hv {le} 900 eV) from a time modulated elliptically polarizing wiggler. The polarization of the soft x-ray beam switches periodically between two opposite polarizations, hence permitting the use of phase-sensitive (lock-in) detection. While the wiggler can be modulated at frequencies up to 100 Hz, switching transients limit the actual practical frequency to {approx}25 Hz. With analog detection, switching transients are blocked by a chopper synchronized to the frequency and phase of the wiggler. The CD is obtained from the ratio of the signal recovered at the frequency of polarization modulation, f, to the average beam intensity, which is recovered by synchronous detection at frequency 2f.

Sutherland, J.C.; Polewski, K.; Monteleone, D.C. [and others

1998-01-23T23:59:59.000Z

85

Structural Study on Moving Magnet Compressor for Stirling Engine  

Science Conference Proceedings (OSTI)

The article describes a structural study on moving magnet compressor for Stirling engine. The performance of Stirling engine is determined by the linear compressor. The article first establishes mathematics models for ordinary linear compressors and ... Keywords: Stirling engine, moving magnet linear compressor, CAE, magnet field analysis

Ding Guozhong; Zhang Xiaoqing; He Mingshun; Shu Shuiming

2010-06-01T23:59:59.000Z

86

Linear collider: a preview  

Science Conference Proceedings (OSTI)

Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

Wiedemann, H.

1981-11-01T23:59:59.000Z

87

Linear phase compressive filter  

DOE Patents (OSTI)

A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

88

Detroit as linear city.  

E-Print Network (OSTI)

??Detroit is a city in decline. Through strategic withdrawal into a linear city its main artery -Woodward Avenue- becomes an assembly line that holds different (more)

Kuys, J.I.

2012-01-01T23:59:59.000Z

89

Focusing in Linear Accelerators  

DOE R&D Accomplishments (OSTI)

Review of the theory of focusing in linear accelerators with comments on the incompatibility of phase stability and first-order focusing in a simple accelerator.

McMillan, E. M.

1950-08-24T23:59:59.000Z

90

Linear Graphene Plasmons  

Science Conference Proceedings (OSTI)

The coupling of the plasmon spectra of graphene and a nearby thick plasma is examined here in detail. The coupled modes include linear plasmons. Keywords: Graphene, plasmons, surface

N. J.M. Horing

2010-11-01T23:59:59.000Z

91

Optimisation of a transverse flux linear PM generator using 3D Finite Element Analysis.  

E-Print Network (OSTI)

??ENGLISH ABSTRACT: Several transverse flux and longitudinal flux linear generator topologies exist for freepiston Stirling engine applications. In this thesis the transverse flux permanent magnet (more)

Schutte, Jacques

2011-01-01T23:59:59.000Z

92

Evidence of a barrier oxidation dependence on the interfacialmagnetism in co/alumina based magnetic tunnel junctions  

SciTech Connect

Soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co L{sub 2,3} edge have been applied to explore the near-interfacial magnetism of Co electrodes in Co/alumina based magnetic tunnel junctions. By taking into account the formation of CoO at the FM/barrier interface, the change in the total magnetic moment on metallic Co atoms as a function of barrier oxidation has been determined. The results demonstrate a strong correlation between the Co moments and measured TMR values, and an enhancement in the Co moments for moderate oxidation times.

Telling, N.D.; van der Laan, G.; Ladak, S.; Hicken, R.J.; Arenholz, E.

2005-09-29T23:59:59.000Z

93

Linear Motor Powered Transportation  

E-Print Network (OSTI)

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. ...

Thornton, Richard D.

94

North Linear Accelerator  

NLE Websites -- All DOE Office Websites (Extended Search)

North Linear Accelerator North Linear Accelerator Building Exterior Beam Enclosure Level Walk to the North Spreader North Recombiner Extras! North Linear Accelerator The North Linear Accelerator is one of the two long, straight sections of Jefferson Lab's accelerator. Electrons gain energy in this section by passing through acceleration cavities. There are 160 cavities in this straightaway, all lined up end to end. That's enough cavities to increase an electron's energy by 400 million volts each time it passes through this section. Electrons can pass though this section as many as five times! The cavities are powered by microwaves that travel down the skinny rectangular pipes from the service buildings above ground. Since the cavities won't work right unless they are kept very cold, they

95

Edges and linearization  

E-Print Network (OSTI)

This thesis is concerned with how grammar determines the phonological consequence of syntactic dislocation. It centers on a hypothesis regarding the linearization of movement chains - the Edge Condition on Copy Deletion, ...

Trinh, Tue H. (Tue Huu)

2011-01-01T23:59:59.000Z

96

Algebraic theory of linear viscoelastic nemattodynamics Part 2: Linear viscoelastic nematic viscoelasticity  

E-Print Network (OSTI)

This second part of paper develops a theory of linear viscoelastic nematodynamics applicable to LCP. The viscous and elastic nematic components in theory are described by using the LEP approach for viscous nematics and de Gennes free energy for weakly elastic nematic elastomers. The case of applied external magnetic field exemplifies the occurrence of non-symmetric stresses. In spite of multi- (10) parametric character of the theory, the use of nematic operators presents it in an elegant form. When the magnetic field is absent, the theory is simplified for symmetric case with 6 parameters, and takes an extremely simple, 2-parametric form for viscoelastic nematodynamics with possible soft deformation modes. It is shown that the linear nematodynamics is always reduced to the LEP-like equations where the coefficients are changed for linear memory functionals whose parameters are calculated from original viscosities and moduli.

Arkady I. Leonov

2004-09-10T23:59:59.000Z

97

Next Linear Collider Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

Welcome to the Next Linear Collider NLC Home Page If you would like to learn about linear colliders in general and about this next-generation linear collider project's mission,...

98

Imaging nanoscale magnetic structures with polarized soft x-ray photons  

SciTech Connect

Imaging nanoscale magnetic structures and their fast dynamics is scientifically interesting and technologically of highest relevance. The combination of circularly polarized soft X-ray photons which provide a strong X-ray magnetic circular dichroism effect at characteristic X-ray absorption edges, with a high resolution soft X-ray microscope utilizing Fresnel zone plate optics allows to study in a unique way the stochastical behavior in the magnetization reversal process of thin films and the ultrafast dynamics of magnetic vortices and domain walls in confined ferromagnetic structures. Future sources of fsec short and high intense soft X-ray photon pulses hold the promise of magnetic imaging down to fundamental magnetic length and time scales.

Fischer, P.; Im, M.-Y.

2010-01-18T23:59:59.000Z

99

XMCD experimental station optimized for ultrathin magnetic films at HiSOR-BL14  

Science Conference Proceedings (OSTI)

We have constructed a system for in situ X-ray magnetic circular dichroism (XMCD) measurements of ultrathin magnetic films at the soft X-ray beamline HiSOR-BL14 at Hiroshima Synchrotron Radiation Center. The XMCD experimental station is directly connected to the beamline, and equipped with a sample fabrication chamber where various types of ultrathin magnetic films can be grown with monatomic layer control. XMCD spectra of the as-grown samples can be measured with adequate precision for the analysis of magnetic moments, under proper control of the light polarization in the beamline optics. This system has enabled the investigation of natural magnetic states in the ultrathin magnetic films without the influence of surface oxidation or any cap-layers.

Sawada, Masahiro; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hirohisma, Hiroshima 739-0046 (Japan); Ueno, Tetsuro; Tagashira, Tetsuro [Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan); Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hirohisma, Hiroshima 739-0046 (Japan); Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan)

2010-06-23T23:59:59.000Z

100

Portable Linear Accelerator Development  

Science Conference Proceedings (OSTI)

This report describes Minac-3, a miniaturized linear accelerator system. It covers the current equipment capabilities and achievable modifications, applications information for prospective users, and technical information on high-energy radiography that is useful for familiarization and planning. The design basis, development, and applications history of Minac are also summarized.

1982-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Evaluation of Power Extraction to Linear Gain Scheduling Controllers in a Small Wind Energy Conversion System  

Science Conference Proceedings (OSTI)

Renewable energy sources have focused a special attention in wind energy conversion systems, where the goal is maximal power extraction. This paper presents an evaluation of the linear controllers eigen structure assingment, linear quadratic regulator, ... Keywords: Wind turbines, permanent magnet synchronous generator, eigenstructure assingment, linear quadratic regulator, loop shaping design procedure

Santiago Sanchez Acevedo; Eduardo Giraldo; Edilson Delgado Trejos

2010-09-01T23:59:59.000Z

102

The TESLA superconducting linear collider  

Science Conference Proceedings (OSTI)

This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA).

R. Brinkmann; the TESLA Collaboration

1997-01-01T23:59:59.000Z

103

Linear induction accelerator  

DOE Patents (OSTI)

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.

Buttram, M.T.; Ginn, J.W.

1988-06-21T23:59:59.000Z

104

Linear Solar Models  

E-Print Network (OSTI)

We present a new approach to study the properties of the sun. We consider small variations of the physical and chemical properties of the sun with respect to Standard Solar Model predictions and we linearize the structure equations to relate them to the properties of the solar plasma. By assuming that the (variation of) the present solar composition can be estimated from the (variation of) the nuclear reaction rates and elemental diffusion efficiency in the present sun, we obtain a linear system of ordinary differential equations which can be used to calculate the response of the sun to an arbitrary modification of the input parameters (opacity, cross sections, etc.). This new approach is intended to be a complement to the traditional methods for solar model calculation and allows to investigate in a more efficient and transparent way the role of parameters and assumptions in solar model construction. We verify that these Linear Solar Models recover the predictions of the traditional solar models with an high...

Villante, F L

2009-01-01T23:59:59.000Z

105

Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators  

SciTech Connect

Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.

V.S. Morozov, S.A. Bogacz, Y.R. Roblin, K.B. Beard

2012-06-01T23:59:59.000Z

106

NON-LINEAR MODELING OF THE RHIC INTERACTION REGIONS.  

Science Conference Proceedings (OSTI)

For RHIC's collision lattices the dominant sources of transverse non-linearities are located in the interaction regions. The field quality is available for most of the magnets in the interaction regions from the magnetic measurements, or from extrapolations of these measurements. We discuss the implementation of these measurements in the MADX models of the Blue and the Yellow rings and their impact on beam stability.

TOMAS,R.FISCHER,W.JAIN,A.LUO,Y.PILAT,F.

2004-07-05T23:59:59.000Z

107

Optical linear algebra  

SciTech Connect

Many of the linear algebra operations and algorithms possible on optical matrix-vector processors are reviewed. Emphasis is given to the use of direct solutions and their realization on systolic optical processors. As an example, implicit and explicit solutions to partial differential equations are considered. The matrix-decomposition required is found to be the major operation recommended for optical realization. The pipelining and flow of data and operations are noted to be key issues in the realization of any algorithm on an optical systolic array processor. A realization of the direct solution by householder qr decomposition is provided as a specific case study. 19 references.

Casasent, D.; Ghosh, A.

1983-01-01T23:59:59.000Z

108

Magnetic field gradient effects on Rayleigh-Taylor instability with continuous magnetic field and density profiles  

SciTech Connect

In this paper, the effects of magnetic field gradient (i.e., the magnetic field transition layer effects) on the Rayleigh-Taylor instability (RTI) with continuous magnetic field and density profiles are investigated analytically. The transition layers of magnetic field and density with two different typical profiles are studied and the analytic expressions of the linear growth rate of the RTI are obtained. It is found that the magnetic field effects strongly reduce the linear growth rate of the RTI, especially when the perturbation wavelength is short. The linear growth rate of the RTI increases with the thickness of the magnetic field transition layer, especially for the case of small thickness of the magnetic field transition layer. When the magnetic field transition layer width is long enough, the linear growth rate of the RTI can be saturated. Thus when one increases the width of the magnetic field transition layer, the linear growth rate of the RTI increases only in a certain range, which depends on the magnetic field strength. The numerical results are compared with the analytic linear growth rates and they agree well with each other.

Yang, B. L. [Graduate School, China Academy of Engineering Physics, Beijing 100088 (China); Wang, L. F.; Ye, W. H. [HEDPS and CAPT, Peking University, Beijing 100871 (China); LCP, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Xue, C. [LCP, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

2011-07-15T23:59:59.000Z

109

Nonlinear Energy Collimation System for Linear Colliders  

E-Print Network (OSTI)

The post-linac energy collimation system of multi-TeV linear colliders is designed to fulfil an important function of protection of the Beam Delivery System (BDS) against miss-steered beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This is a very challenging task, assuming the nominal CLIC beam parameters at 1.5 TeV beam energy. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a skew sextupole pair for energy collimation. Performance simulation results are also presented.

Resta-Lopez, Javier

2011-01-01T23:59:59.000Z

110

Linear Collider Collaboration Tech Notes LCC-0110  

NLE Websites -- All DOE Office Websites (Extended Search)

0 0 December 2002 Post-Target Beamline Design for Proposed FFTB Experiment with Polarized Positrons Y. K. Batygin and J. C. Sheppard Stanford Linear Accelerator Center Stanford University Menlo Park, CA 04025 Abstract: The beamline after positron production target for the proposed experiment E-166 is discussed. The beamline includes bending magnets and solenoid to deliver polarized positron beam from the target to polarimeter. Results of simulation indicate that transmission efficiency of 1...3 % with beam polarization of 60...80 % can be obtained if beam energy resolution is required while the transmission of 40...77 % and polarization of 40% can be obtained without beam energy resolution. 13 December 2002

111

Piecewise Linear Modeling and Analysis  

Science Conference Proceedings (OSTI)

From the Publisher:Piecewise Linear Modeling and Analysis explains in detail all possible model descriptions to efficiently store piecewise linear functions starting with the Chua descriptions. Detailed explanation on how the model parameter can be obtained ...

Domine M. W. Leenaerts; Wim M. Van Bokhoven

1998-07-01T23:59:59.000Z

112

History of Proton Linear Accelerators  

DOE R&D Accomplishments (OSTI)

Some personal recollections are presented that relate to the author`s experience developing linear accelerators, particularly for protons. (LEW)

Alvarez, L. W.

1987-01-00T23:59:59.000Z

113

Linearized Additive Classifiers  

E-Print Network (OSTI)

We revisit the additive model learning literature and adapt a penalized spline formulation due to Eilers and Marx, to train additive classifiers efficiently. We also propose two new embeddings based two classes of orthogonal basis with orthogonal derivatives, which can also be used to efficiently learn additive classifiers. This paper follows the popular theme in the current literature where kernel SVMs are learned much more efficiently using a approximate embedding and linear machine. In this paper we show that spline basis are especially well suited for learning additive models because of their sparsity structure and the ease of computing the embedding which enables one to train these models in an online manner, without incurring the memory overhead of precomputing the storing the embeddings. We show interesting connections between B-Spline basis and histogram intersection kernel and show that for a particular choice of regularization and degree of the B-Splines, our proposed learning algorithm closely appr...

Maji, Subhransu

2011-01-01T23:59:59.000Z

114

HEAVY ION LINEAR ACCELERATOR  

DOE Patents (OSTI)

A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

Van Atta, C.M.; Beringer, R.; Smith, L.

1959-01-01T23:59:59.000Z

115

Development of a Novel Linear Magnetostrictive Actuator  

E-Print Network (OSTI)

This dissertation presents the development of a novel linear magnetostrictive actuator. The magnetostrictive material used here is Terfenol-D, an alloy of the formula Tb0.3Dy0.7Fe1.92. In response to a traveling magnetic field inside the Terfenol-D element, it moves in the opposite direction with a peristaltic motion. The proposed design offers the flexibility to operate the actuator in various configurations including local and conventional three-phase excitation. The conceptual design of the linear magnetostrictive actuator was performed during which different configurations were analyzed. Finite Element Analysis (FEA) was extensively used for magnetic circuit design and analysis in conceptual design. Eventually one of these designs was chosen based on which detailed design of linear magnetostrictive actuator was carried out. A new force transmission assembly incorporates spring washers to avoid the wear due to the sudden collision of Terfenol-D element with the force transmission assembly. All mechanical parts were then fabricated at the mechanical engineering machine shop. The power electronics to operate the motor in a local three-phase mode was designed and implemented. It was demonstrated that the power consumption can be reduced significantly by operating the magnetostrictive linear actuator in the local excitation mode. A finite-element model of the actuator was developed using ATILA and an empirical model was presented using the data gathered from numerous tests performed on the actuator. The closed-loop control system was implemented using relay control which resulted in an optimal closed-loop performance. The magnetostrictive actuator has demonstrated 410-N load capacity with a travel range of 45 mm, and the maximum speed is 9 mm/min. The maximum power consumption by the motor is 95 W. The sensorless control of the linear magnetostrictive actuator was successfully conducted using two different approaches. First, using a linear-approximation method, we achieved a position estimation capability with 1 mm error. Then, an adaptive neuro-fuzzy inference system was employed for estimating the position which resulted in a position estimation capability with only a 0.5 mm error.

Sadighi, Ali

2010-08-01T23:59:59.000Z

116

Propulsion and stabilization system for magnetically levitated vehicles  

DOE Patents (OSTI)

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

Coffey, Howard T. (Darien, IL)

1993-06-29T23:59:59.000Z

117

Propulsion and stabilization system for magnetically levitated vehicles  

DOE Patents (OSTI)

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

Coffey, H.T.

1992-12-31T23:59:59.000Z

118

Use of POISSON to calculate the effect of magnetization in superconducting magnets  

SciTech Connect

The code POISSON is used to model a superconducting magnet. Two methods are used: a linear and reversible magnetization curve for which an analytical solution is compared with that of POISSON and a measured magnetization curve of a superconducting cable is introduced into POISSON and the results are compared with measurements. 13 figs. (WRF)

Caspi, S.; Gilbert, W.S.; Helm, M.; Laslett, L.J.

1985-08-01T23:59:59.000Z

119

Superconducting Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

magnet technology has allowed physicists to attain higher energies in circular accelerators. One can obtain higher magnetic fields because there is no resistance in a...

120

Linear induction pump  

DOE Patents (OSTI)

Electromagnetic linear induction pump for liquid metal which includes a unitary pump duct. The duct comprises two substantially flat parallel spaced-apart wall members, one being located above the other and two parallel opposing side members interconnecting the wall members. Located within the duct are a plurality of web members interconnecting the wall members and extending parallel to the side members whereby the wall members, side members and web members define a plurality of fluid passageways, each of the fluid passageways having substantially the same cross-sectional flow area. Attached to an outer surface of each side member is an electrically conductive end bar for the passage of an induced current therethrough. A multi-phase, electrical stator is located adjacent each of the wall members. The duct, stators, and end bars are enclosed in a housing which is provided with an inlet and outlet in fluid communication with opposite ends of the fluid passageways in the pump duct. In accordance with a preferred embodiment, the inlet and outlet includes a transition means which provides for a transition from a round cross-sectional flow path to a substantially rectangular cross-sectional flow path defined by the pump duct.

Meisner, John W. (Newbury Park, CA); Moore, Robert M. (Canoga Park, CA); Bienvenue, Louis L. (Chatsworth, CA)

1985-03-19T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Berkeley Proton Linear Accelerator  

DOE R&D Accomplishments (OSTI)

A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

1953-10-13T23:59:59.000Z

122

Solving linear program as linear system in polynomial time  

Science Conference Proceedings (OSTI)

A physically concise polynomial-time iterative-cum-non-iterative algorithm is presented to solve the linear program (LP) Minc^txsubject toAx=b,x>=0. The iterative part-a variation of Karmarkar projective transformation algorithm-is essentially due to ... Keywords: Barnes algorithm, Error-free computation, Linear program, Linear system, Matlab program, Polynomial-time iterative-cum-non-iterative algorithm

Syamal K. Sen; Suja Ramakrishnan; Ravi P. Agarwal

2011-03-01T23:59:59.000Z

123

Linear Accelerator | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

electrons emitted from a cathode heated to 1100 C. The electrons are accelerated by high-voltage alternating electric fields in a linear accelerator (linac; photo below)....

124

Common Origin of the Circular-dichroism Pattern in ARPES of SrTiO3 and CuxBi2Se3  

SciTech Connect

We investigate circular dichroism in the angular distribution (CDAD) of photoelectrons from SrTiO{sub 3}:Nb and Cu{sub x}Bi{sub 2}Se{sub 3} recorded by 7-eV laser ARPES. In addition to the well-known node that occurs in CDAD when the incidence plane matches the mirror plane of the crystal, we show that another type of node occurs when the mirror plane of the crystal is vertical to the incidence plane and the electronic state is two dimensional. The flower-shaped CDAD's occurring around the Fermi level of SrTiO{sub 3}:Nb and around the Dirac point of Cu{sub x}Bi{sub 2}Se{sub 3} are explained on equal footings. A surface-state-to-surface-resonance transition is indicated for the topological state of Cu{sub x}Bi{sub 2}Se{sub 3}.

Bell, Christopher

2011-08-19T23:59:59.000Z

125

High force density linear permanent magnet motors : "electromagnetic muscle actuators"  

E-Print Network (OSTI)

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, ...

Ruddy, Bryan P. (Bryan Paul), 1983-

2012-01-01T23:59:59.000Z

126

Implementing Distributed Systems Using Linear Naming  

E-Print Network (OSTI)

Linear graph reduction is a simple computational model in which the cost of naming things is explicitly represented. The key idea is the notion of "linearity". A name is linear if it is only used once, so with linear ...

Bawden, Alan

1993-03-01T23:59:59.000Z

127

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

1 03/12/99 1 03/12/99 NLC Damping Ring Wiggler Studies 1999 December 3, 1999 J. Corlett, N. Hartmann, K. Kennedy, G. Koehler, S. Marks, J. Rasson, T. Saleh Lawrence Berkeley National Laboratory Berkeley, CA, USA Abstract: The primary objective of FY99 was to develop credible conceptual wiggler requirements. Three magnet technologies were considered: electromagnet, hybrid permanent magnet and superconducting. Based upon an early assessment of requirements, a hybrid magnet similar to existing designs, with appropriate modification of gap and period, satisfies basic requirements. However, radiation damage is potentially a serious problem for the ND-FE-B permanent magnet material, and cost remains an issue for samarium cobalt magnets. Therefore the primary effort was put into developing a radiation-hard electromagnet wiggler conceptual

128

Linear Collider Collaboration Tech Notes LCC-0109  

NLE Websites -- All DOE Office Websites (Extended Search)

9 9 TESLA 2002-11 CBP Tech Note-269 November 2002 Alignment Stability Models for Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Linear collider damping rings are highly sensitive to magnet alignment. Emittance tuning simulations for current designs of damping rings for TESLA and NLC have given encouraging results, but depend on invasive measurements of dispersion. The frequency with which such measurements must be made is therefore an operational issue, and depends on the time stability of the alignment. In this note, we consider three effects that lead to misalignment and the need to retune the damping ring: (1)

129

Acceleration Modules in Linear Induction Accelerators  

E-Print Network (OSTI)

Linear Induction Accelerator (LIA) is a unique type of accelerator, which is capable to accelerate kiloAmpere charged particle current to tens of MeV energy. The present development of LIA in MHz busting mode and successful application into synchrotron broaden LIAs usage scope. Although transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. Authors examined the transition of the magnetic cores functions during LIA acceleration modules evolution, distinguished transformer type and transmission line type LIA acceleration modules, and reconsidered several related issues based on transmission line type LIA acceleration module. The clarified understanding should be helpful in the further development and design of the LIA acceleration modules.

Wang, Shaoheng

2013-01-01T23:59:59.000Z

130

BEAM-BASED NON-LINEAR OPTICS CORRECTIONS IN COLLIDERS.  

Science Conference Proceedings (OSTI)

A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, that gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 4 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non-linear correction techniques.

PILAT, R.; LUO, Y.; MALITSKY, N.; PTITSYN, V.

2005-05-16T23:59:59.000Z

131

Original articles: Vortex states in axially symmetric superconductors in applied magnetic field  

Science Conference Proceedings (OSTI)

We solve analytically the linearized Ginzburg-Landau (GL) equation in the presence of an uniform magnetic field with cylindrical boundary conditions. The solution of the non-linear GL equation is provided as an expansion in the basis of linearized solutions. ... Keywords: Axial magnetic field, Mesoscopic superconductivity, Nonlinear Ginzburg-Landau equation, Vortex

Andrei Ludu; Milorad V. Miloevi?; Francois M. Peeters

2012-03-01T23:59:59.000Z

132

Adjustable permanent quadrupoles for the next linear collider  

Science Conference Proceedings (OSTI)

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.

James T. Volk et al.

2001-06-22T23:59:59.000Z

133

Superconducting Magnet Division | Brookhaven National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Magnet Division Superconducting Magnet Division Home Production & Testing LHC Dipole Acceptance APUL Schedule (pdf) Projects Main Projects HTS Magnet Program High Field Magnet R&D Linear Collider Final Focus e Lens Solenoid Correctors for J-PARC Correctors for SuperKEKB IR Magnets LARP APUL Past Projects BEPC-II IR Quadrupoles Bio-Med Variable Field MRI GSI Rapid Cycling Magnets Helical Magnets HERA upgrade LHC IR Dipoles RHIC Publications Search Publications Selected Cryogenic Data Notebook Proceedings of the 1968 Summer Study on Superconducting Devices and Accelerators Meetings & Workshops Safety Environmental, Safety & Health ES&H Documents Lockout-Tagout Personnel Staff Pages Ramesh Gupta Brett Parker Peter Wanderer Pe ter Wanderer, head of Brookhaven's Superconducting Magnet Division,

134

Magnetic Storms  

Science Conference Proceedings (OSTI)

... magnetic reversal. As there is no predictive science of geomagnetism, we currently lack even simple forecasts. Our scientific ...

2010-10-05T23:59:59.000Z

135

Magnetic Imaging  

Science Conference Proceedings (OSTI)

... data-storage and permanent magnets with increased energy products, in ... Optimization of future materials, including improved yields, requires an ...

2012-10-02T23:59:59.000Z

136

Magnetic Properties  

Science Conference Proceedings (OSTI)

...Since the discovery of high-temperature superconductors in 1986 (Ref 10), the demonstration of magnetic flux exclusion

137

Linear diffusion into a Faraday cage.  

SciTech Connect

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.

Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

2011-11-01T23:59:59.000Z

138

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

section. The new bends are 34 times stronger than in the ZDR type design and generate an order of magnitude larger dispersion. Magnet parameters at 8 GeV for the new optics are...

139

Radio-frequency quadrupole resonator for linear accelerator  

DOE Patents (OSTI)

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.

Moretti, A.

1982-10-19T23:59:59.000Z

140

Constructions of fault tolerant linear compressors and linear decompressors  

E-Print Network (OSTI)

Abstract The constructions of optical buffers is one of the most critically sought after optical technologies in all-optical packet-switched networks, and constructing optical buffers directly via optical Switches and fiber Delay Lines (SDL) has received a lot of attention recently in the literature. A practical and challenging issue of the constructions of optical buffers that has not been addressed before is on the fault tolerant capability of such constructions. In this paper, we focus on the constructions of fault tolerant linear compressors and linear decompressors. The basic network element for our constructions is scaled optical memory cell, which is constructed by a 2 2 optical crossbar switch and a fiber delay line. We give a multistage construction of a self-routing linear compressor by a concatenation of scaled optical memory cells. We also show that if the delays, say d1, d2,..., dM, of the fibers in the scaled optical memory cells satisfy a certain condition (specifically, the condition in (A2) given in Section I), then our multistage construction can be operated as a self-routing linear compressor with maximum delay ? M?F even after up to F of the M scaled optical memory cells fail to function properly, where 0 ? F ? M ? 1. Furthermore, we prove that our multistage construction with the fiber delays d1, d2,..., dM given by the generalized Fibonacci series of order F is the best among all constructions of a linear compressor that can tolerate up to F faulty scaled optical memory cells by using M scaled optical memory cells. Similarly results are also obtained for the constructions of fault tolerant linear decompressors. I.

Cheng-shang Chang; Tsz-hsuan Chao; Jay Cheng; Duan-shin Lee

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

SunShot Initiative: Linear Fresnel  

NLE Websites -- All DOE Office Websites (Extended Search)

Linear Fresnel to someone by Linear Fresnel to someone by E-mail Share SunShot Initiative: Linear Fresnel on Facebook Tweet about SunShot Initiative: Linear Fresnel on Twitter Bookmark SunShot Initiative: Linear Fresnel on Google Bookmark SunShot Initiative: Linear Fresnel on Delicious Rank SunShot Initiative: Linear Fresnel on Digg Find More places to share SunShot Initiative: Linear Fresnel on AddThis.com... Concentrating Solar Power Systems Parabolic Trough Linear Fresnel Power Tower Dish Engine Components Competitive Awards Staff Photovoltaics Systems Integration Balance of Systems Linear Fresnel DOE funds solar research and development (R&D) in linear Fresnel systems as one of four CSP technologies aiming to meet the goals of the SunShot Initiative. Linear Fresnel systems, which are a type of linear

142

Non-linear image processing  

SciTech Connect

Processing of nuclear medicine images is generally performed by essentially linear methods with the non-negativity condition being applied as the only non-linear process. The various methods used: matrix methods in signal space and Fourier or Hadamard transforms in frequency or sequency space are essentially equivalent. Further improvement in images can be obtained by the use of inherently non-linear methods. The recent development of an approximation to a least-difference method (as opposed to a least-square method) has led to an appreciation of the effects of data bounding and to the development of a more powerful process. Data bounding (modification of statistically improbable data values) is an inherently non-linear method with considerable promise. Strong bounding depending on two-dimensional least-squares fitting yields a reduction of mottling (buttermilk effect) not attainable with linear processes. A pre- bounding process removing very bad points is used to protect the strong bounding process from incorrectly modifying data points due to the weight of an extreme but yet unbounded point as the fitting area approaches it. (auth)

Bell, P.R.; Dillon, R.S.; Bell, M.R.

1976-01-01T23:59:59.000Z

143

LINEAR COUNT-RATE METER  

DOE Patents (OSTI)

A linear count-rate meter is designed to provide a highly linear output while receiving counting rates from one cycle per second to 100,000 cycles per second. Input pulses enter a linear discriminator and then are fed to a trigger circuit which produces positive pulses of uniform width and amplitude. The trigger circuit is connected to a one-shot multivibrator. The multivibrator output pulses have a selected width. Feedback means are provided for preventing transistor saturation in the multivibrator which improves the rise and decay times of the output pulses. The multivibrator is connected to a diode-switched, constant current metering circuit. A selected constant current is switched to an averaging circuit for each pulse received, and for a time determined by the received pulse width. The average output meter current is proportional to the product of the counting rate, the constant current, and the multivibrator output pulse width.

Henry, J.J.

1961-09-01T23:59:59.000Z

144

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

6, 27/05/99 6, 27/05/99 Tolerances of Random RF Jitters in X-Band Main Linacs May 27, 1999 Kiyoshi KUBO KEK Tsukuba, Japan Abstract: Tracking simulations have been performed for the main linacs of an X-band linear collider. We discuss the choice of phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. Tolerances of Random RF Jitters in X-Band Main Linacs K. Kubo, KEK Abstract Tracking simulations have been performed for main linacs of X-band linear collider. We discuss about choice of the phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. 1 INTRODUCTION In order to preserve the low emittance through the main linacs of future linear colliders, various effects

145

Magnetic Materials  

Science Conference Proceedings (OSTI)

Oct 27, 2009 ... Extreme magnetic fields (>2 tesla), especially when combined with temperature, are being shown to revolutionize materials processing and...

146

A polynomial projection algorithm for linear programming  

E-Print Network (OSTI)

Jul 5, 2013 ... Abstract: We propose a polynomial algorithm for linear programming. The algorithm represents a linear optimization or decision problem in the...

147

Annual Planning Summaries: Stanford Linear Accelerator (SLAC...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stanford Linear Accelerator (SLAC) Annual Planning Summaries: Stanford Linear Accelerator (SLAC) Document(s) Available For Download January 11, 2012 2012 Annual Planning Summary...

148

Linear Circuits Designation: Required course  

E-Print Network (OSTI)

circuits. Node and mesh analysis. Operational amplifiers. Signal acquisition and conditioning. Electric, 11k). Objective 4: To acquaint students with the rudiments of electrical-to-mechanical energy) Steady-state and dynamic behavior of linear, lumped-parameter electrical circuits. Kirchoff's laws. RLC

Krstic, Miroslav

149

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry. 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.

McComas, David J. (Los Alamos, NM); Nordholt, Jane E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

150

Linear electric field mass spectrometry  

DOE Patents (OSTI)

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.

McComas, D.J.; Nordholt, J.E.

1992-12-01T23:59:59.000Z

151

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

McComas, D.J.; Nordholt, J.E.

1991-03-29T23:59:59.000Z

152

Superconducting Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

Mit Hilfe der Technologie supraleitender Magnete lassen sich in Mit Hilfe der Technologie supraleitender Magnete lassen sich in Ringbeschleunigern höhere Energien erreichen. Weil supraleitende Spulen keinen elektrischen Widerstand aufweisen, können damit stärkere Magnetfelder erzeugt werden. In normal leitenden Elektromagneten wird - wegen des elektrischen Widerstands der Drähte - die Spule aufgeheizt. Auf diese Weise geht sehr viel Energie in Form von Wärme verloren, was die Energiekosten dieser Magnete in die Höhe treibt. Supraleitende Spulen erlauben es, Magnete grosser Feldstärke unter günstigen Bedingungen zu betreiben und damit die Energiekosten zu senken. Durch den Einbau supraleitender Spulen in den Ringbeschleuniger von Fermilab konnte dessen Energie verdoppelt werden.Auch der im Bau befindliche "Large Hadron Collider" am CERN wird supraleitende Magnete

153

Magnetic nanotubes  

DOE Patents (OSTI)

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.

Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

2010-11-16T23:59:59.000Z

154

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

Notes Notes LCC - 0018, 15/06/99 Rev B, June 2002 Correct Account of RF Deflections in Linac Acceleration June 15, 1999 G.V. Stupakov Stanford Linear Accelerator Center Stanford, California Abstract: During acceleration in the linac structure, the beam not only increases its longitudinal momentum, but also experiences a transverse kick from the accelerating mode which is linear in accelerating gradient. This effect is neglected in such computer codes as LIAR and TRANSPORT. We derived the Hamiltonian equations that describe the effect of RF deflection into the acceleration process and included it into the computational engine of LIAR. By comparing orbits for the NLC main linac, we found that the difference between the two algorithms is about 10\%. The effect will be more pronounced at smaller

155

Solving Fuzzy Linear Regression with Hybrid Optimization  

Science Conference Proceedings (OSTI)

Fuzzy linear regression is an important tool to find the linear inexact relationship between uncertain data. We then propose a hybrid optimization method based on tabu search and harmony search as a potential way of solving fuzzy linear regression. The ... Keywords: Fuzzy linear regression, Harmony search, Hybrid optimization, Tabu search

M. H. Mashinchi; M. A. Orgun; M. Mashinchi

2009-12-01T23:59:59.000Z

156

Cast dielectric composite linear accelerator  

DOE Patents (OSTI)

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.

Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)

2009-11-10T23:59:59.000Z

157

Segmented rail linear induction motor  

DOE Patents (OSTI)

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.

Cowan, Jr., Maynard (1107 Stagecoach Rd. SE., Albuquerque, NM 87123); Marder, Barry M. (1412 Pinnacle View Dr. NE., Albuquerque, NM 87123)

1996-01-01T23:59:59.000Z

158

Segmented rail linear induction motor  

DOE Patents (OSTI)

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.

Cowan, M. Jr.; Marder, B.M.

1996-09-03T23:59:59.000Z

159

Precision linear ramp function generator  

DOE Patents (OSTI)

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.

Jatko, W.B.; McNeilly, D.R.; Thacker, L.H.

1984-08-01T23:59:59.000Z

160

Charged relativistic fluids and non-linear electrodynamics  

E-Print Network (OSTI)

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.

T. Dereli; R. W. Tucker

2010-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Nuclear Magnetic Resonance Laboratory  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance Laboratory. ... A 600 MHz Nuclear Magnetic Resonance Spectrometer. Analytical Data Compilation Reference Materials. ...

2012-10-01T23:59:59.000Z

162

Low-temperature magnetization of (Ga,Mn) As semiconductors  

E-Print Network (OSTI)

We report on a comprehensive study of the ferromagnetic moment per Mn atom in (Ga,Mn)As ferromagnetic semiconductors. Theoretical discussion is based on microscopic calculations and on an effective model of Mn local moments antiferromagnetically coupled to valence band hole spins. The validity of the effective model over the range of doping studied is assessed by comparing with microscopic tight-binding/coherent-potential approximation calculations. Using the virtual crystal k center dot p model for hole states, we evaluate the zero-temperature mean-field contributions to the magnetization from the hole kinetic and exchange energies, and magnetization suppression due to quantum fluctuations of Mn moment orientations around their mean-field ground state values. Experimental low-temperature ferromagnetic moments per Mn are obtained by superconducting quantum interference device and x-ray magnetic circular dichroism measurements in a series of (Ga,Mn)As semiconductors with nominal Mn doping ranging from similar to 2 to 8%. Hall measurements in as-grown and annealed samples are used to estimate the number of uncompensated substitutional Mn moments. Based on our comparison between experiment and theory we conclude that all these Mn moments in high quality (Ga,Mn)As materials have nearly parallel ground state alignment.

Jungwirth, T.; Masek, J.; Wang, KY; Edmonds, KW; Sawicki, M.; Polini, M.; Sinova, Jairo; MacDonald, AH; Campion, RP; Zhao, LX; Farley, NRS; Johal, TK; van der Laan, G.; Foxon, CT; Gallagher, BL.

2006-01-01T23:59:59.000Z

163

Learning About Magnets!  

NLE Websites -- All DOE Office Websites (Extended Search)

the the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a force that can "attract" or "repel" other magnets and magnetic materials, like iron or nickel. What is a Magnet? This bar magnet is a permanent magnet. Permanent magnets can be found in the Earth as rocks and metals. Magnets have

164

Laminated grid and web magnetic cores  

DOE Patents (OSTI)

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.

Sefko, John (Monroeville, PA); Pavlik, Norman M. (Plum Borough, PA)

1984-01-01T23:59:59.000Z

165

Inverse Faraday Effect with Linearly Polarized Laser Pulses  

Science Conference Proceedings (OSTI)

The inverse Faraday effect is usually associated with circularly polarized radiation; here, we show that it can also occur for linearly polarized radiation. The quasistatic axial magnetic field generated by a laser propagating in plasma can be calculated by considering both the spin and the orbital angular momenta of the laser pulse. A net spin is present when the radiation is circularly polarized and a net orbital angular momentum is present if there is any deviation from perfect rotational symmetry. The orbital angular momentum gives an additional contribution to the axial magnetic field that can enhance or reduce the effect usually attributed to circular polarization and strongly depends on the intensity profile of the Laguerre-Gaussian modes involving the azimuthal and radial mode numbers.

Ali, S. [Instituto de Plasmas e Fusao Nuclear--Laboratorio Associado, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Davies, J. R.; Mendonca, J. T. [Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

2010-07-16T23:59:59.000Z

166

Thoughts on Incorporating HPRF in a Linear Cooling Channel  

DOE Green Energy (OSTI)

We discuss a possible implementation of high-pressure gas-filled RF (HPRF) cavities in a linear cooling channel for muons and some of the technical issues that must be dealt with. The approach we describe is a hybrid approach that uses high-pressure hydrogen gas to avoid cavity breakdown, along with discrete LiH absorbers to provide the majority of the energy loss. Initial simulations show that the channel performs as well as the original vacuum RF channel while potentially avoiding the degradation in RF gradient associated with the strong magnetic field in the cooling channel.

Gallardo, Juan C.; Zisman, Michael S

2009-08-20T23:59:59.000Z

167

The Next Linear Collider Program  

NLE Websites -- All DOE Office Websites (Extended Search)

To use the left side navigation on this page, you will need to turn on To use the left side navigation on this page, you will need to turn on Javascript. You do not need JavaScript to use the text-based navigation bar at the bottom of the page. The Next Linear Collider at SLAC Navbar MISSION: Scientists expect research at this facility to answer fundamental questions about the behavior of matter and the origins of the Universe. NLC 8-Pack on the Drawing Board What's New In the Next Linear Collider: • NLC Newsletter October, 2001 • NLC Snowmass report 2001 • NLC All Hands Talk, August 2001 Upcoming Events: • Fall 2001 Working Sessions, Oct. 22-23, 2001 • Pulse Compression Workshop, Oct. 22-24, 2001 • Machine Advisory Committee Mtg., Oct. 24-26, 2001 • ISG-7 at KEK, Nov. 12-15, 2001 • LC' 02 at SLAC, Feb. 4-8, 2002 NLC Website Search: Entire SLAC Web | Help |

168

Neutrino magnetic moment in a magnetized plasma  

E-Print Network (OSTI)

The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.

N. V. Mikheev; E. N. Narynskaya

2010-11-08T23:59:59.000Z

169

Impact of Permanent Magnet Field on Inductance Variation of a PMLSM Julien Gomand1  

E-Print Network (OSTI)

of Surface Mounted Permanent Magnet Linear Synchronous Motors are generally presented with constantImpact of Permanent Magnet Field on Inductance Variation of a PMLSM Julien Gomand1 , Ghislain Remy1 Linear drive, Modelling, Estimation technique, Synchronous motor, Harmonics. Abstract Analytical models

Paris-Sud XI, Université de

170

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

SciTech Connect

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.

Qiao, S.; /Stanford U., Appl. Phys. Dept. /SLAC, SSRL /LBNL, ALS /Fudan U.; Ma, De-wei; Feng, Dong-lai; /Fudan U.; Hussain, Z.; /LBNL, ALS; Shen, Z.-X.; /Stanford U., Appl. Phys. Dept. /SLAC, SSRL

2009-06-19T23:59:59.000Z

171

Linear Concentrator Systems for Concentrating Solar Power  

Energy.gov (U.S. Department of Energy (DOE))

Linear concentrating solar power (CSP) collectors capture the sun's energy with large mirrors that reflect and focus the sunlight onto a linear receiver tube. The receiver contains a fluid that is...

172

A polynomial projection algorithm for linear programming  

E-Print Network (OSTI)

a linear optimization or decision problem in the form of a system of linear ... we understand the number of arithmetic and the other elementary operations ..... where M is a diagonal matrix whose entries on the main diagonal are non-

173

Proof Synthesis and Reflection for Linear Arithmetic  

Science Conference Proceedings (OSTI)

This article presents detailed implementations of quantifier elimination for both integer and real linear arithmetic for theorem provers. The underlying algorithms are those by Cooper (for Z) and by Ferrante and Rackoff ... Keywords: Linear arithmetic, Proof synthesis, Reflection

Amine Chaieb; Tobias Nipkow

2008-07-01T23:59:59.000Z

174

New architecture for RF power amplifier linearization  

E-Print Network (OSTI)

Power amplifier linearization has become an important part of the transmitter system as 3G and developing 4G communication standards require higher linearity than ever before. The thesis proposes two power amplifier ...

Boo, Hyun H

2009-01-01T23:59:59.000Z

175

Linear Stability of Modons on a Sphere  

Science Conference Proceedings (OSTI)

The linear stability of two stationary dipolar modon solutions of the nondivergent barotropic vorticity equation on a rotating sphere is investigated. A numerical normal mode analysis of the linearized equation is performed by solving the ...

E. C. Neven

2001-08-01T23:59:59.000Z

176

PLATO: a new piecewise linear simulation tool  

Science Conference Proceedings (OSTI)

This paper describes the basic concepts of a new piecewise linear circuit simulation program called PLATO. Piecewise linear modeling is a very generic and powerful approach to the modeling of electronic components. It allows for the use of macro modeling ...

M. T. van Stiphout; J. T. J. van Eijndhoven; H. W. Buurman

1990-03-01T23:59:59.000Z

177

Energy Basics: Linear Concentrator Systems for Concentrating...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Solar Photovoltaics Concentrating Solar Power Linear...

178

Summary of Linear Elastic Fracture Mechanics Concepts  

Science Conference Proceedings (OSTI)

...in this Volume."Stress Intensity Factors"A brief summary of linear elastic fracture mechanics (LEFM) concepts

179

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

5 08//00 5 08//00 Study of Beam Energy Spectrum Measurement in the NLC Extraction Line August 2000 Yuri Nosochkov and Tor Raubenheimer Stanford Linear Accelerator Center Stanford, CA Abstract: The NLC extraction line optics includes a secondary focal point with a very small _- function and 2 cm dispersion which can be used for measurement of outgoing beam energy spread. In this study, we performed tracking simulations to transport the NLC disrupted beam from the Interaction Point (IP) to the extraction line secondary focus (the IP image), `measure' the transverse beam pro_le at the IP image and reconstruct the beam energy spectrum. The resultant distribution was compared with the original energy spectrum at the IP. Study of Beam Energy Spectrum Measurement

180

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

2 03/12/99 2 03/12/99 PEP-II RF Cavity Revisited December 3, 1999 R. Rimmer, G. Koehler, D. Li, N. Hartmann, N. Folwell, J. Hodgson, B. McCandless Lawrence Berkeley National Laboratory Stanford Linear Accelerator Center Berkeley, CA, USA Stanford, CA, USA Abstract: This report describes the results of numerical simulations of the PEP-II RF cavity performed after the completion of the construction phase of the project and comparisons are made to previous calculations and measured results. These analyses were performed to evaluate new calculation techniques for the HOM distribution and RF surface heating that were not available at the time of the original design. These include the use of a high frequency electromagnetic element in ANSYS and the new Omega 3P code to study wall

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

4, 10/03/00 4, 10/03/00 Luminosity for NLC Design Variations March 10, 1999 K.A. Thompson and T.O. Raubenheimer Stanford Linear Accelerator Center Stanford, CA, USA Abstract: In this note we give Guineapig simulation results for the luminosity and luminosity spectrum of three baseline NLC designs at 0.5~TeV and 1.0~TeV and compare the simulation results with analytic approximations. We examine the effects of varying several design parameters away from the NLC-B-500 and NLC-B-1000 designs, in order to study possible trade-offs of parameters that could ease tolerances, increase luminosity, or help to optimize machine operation for specific physics processes. Luminosity for NLC Design Variations K.A. Thompson and T.O.Raubenheimer INTRODUCTION In this note we give Guineapig [l] simulation results for the luminosity and

182

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

1 1 May 2001 Lattice Description for NLC Damping Rings at 120 Hz Andrzej Wolski Lawrence Berkeley National Laboratory Abstract: We present a lattice design for the NLC Main Damping Rings at 120 Hz repe tition rate. A total wiggler length of a little over 46 m is needed to achieve the damping time required for extracted, normalized, vertical emittance below 0.02 mm mrad. The dynamic aperture (using a linear model for the wiggler) is in excess of 15 times the injected beam size. The principal lattice parameters and characteristics are presented in this note; we also outline results of studies of alignment and field quality tolerances. CBP Tech Note-227 LCC-0061 Lattice Description for NLC Main Damping Rings at 120 Hz Andrzej Wolski Lawrence Berkeley National Laboratory

183

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

0 0 April 2001 Rev.1 July 2003 Guide to LIBXSIF, a Library for Parsing the Extended Standard Input Format of Accelerated Beamlines Peter G. Tenenbaum Stanford Linear Accelerator Center Stanford University Stanford, CA Abstract: We describe LIBXSIF, a standalone library for parsing the Extended Standard Input Format of accelerator beamlines. Included in the description are: documentation of user commands; full description of permitted accelerator elements and their attributes; the construction of beamline lists; the mechanics of adding LIBXSIF to an existing program; and "under the hood" details for users who wish to modify the library or are merely morbidly curious. Guide to LIBXSIF, a Library for Parsing the Extended Standard Input Format of

184

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

NLC Home Page NLC Technical SLAC The LCC Tech Note series was started in July 1998 to document the JLC/NLC collaborative design effort. The notes are numbered sequentially and may also be given a SLAC, FNAL, LBNL, LLNL and/or KEK publication number. The LCC notes will be distributed through the Web in electronic form as PDF files -- the authors are responsible for keeping the original documents. Other document series are the NLC Notes that were started for the SLAC ZDR, the KEK ATF Notes, and at some future time there should be a series of Technical (NLD) Notes to document work on detector studies for the next-generation linear collider. LCC-0001 "Memorandum of Understanding between KEK and SLAC," 2/98. LCC-0002 "Transparencies and Summaries from the 1st ISG meeting: January 1998," G. Loew, ed., 2/98.

185

Reticle stage based linear dosimeter  

DOE Patents (OSTI)

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.

Berger, Kurt W. (Livermore, CA)

2007-03-27T23:59:59.000Z

186

On the equivalence of linear complementarity problems  

Science Conference Proceedings (OSTI)

We show that the Extended Linear Complementarity Problem (ELCP) can be recast as a standard Linear Complementarity Problem (LCP) provided that the surplus variables or the feasible set of the ELCP are bounded. Since many extensions of the LCP are special ... Keywords: Complementarity problems, Integer programming, Linear complementarity problem, Nonlinear algorithms, Optimization

B. De Schutter; W. P. M. H. Heemels; A. Bemporad

2002-08-01T23:59:59.000Z

187

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Scale Superconducting Magnetic Energy Storage Plant", IEEEfor SlIperconducting Magnetic Energy Storage Unit", inSuperconducting Magnetic Energy Storage Plant, Advances in

Hassenzahl, W.

2011-01-01T23:59:59.000Z

188

Magnetization Characterization Laboratory  

Science Conference Proceedings (OSTI)

... use of magnetic materials for motors, generators, transformers ... all depend on the specific magnetic characteristics of ... For example, a magnet used in ...

2012-10-23T23:59:59.000Z

189

MAGNETIC GRID  

DOE Patents (OSTI)

An electronic grid is designed employing magnetic forces for controlling the passage of charged particles. The grid is particularly applicable to use in gas-filled tubes such as ignitrons. thyratrons, etc., since the magnetic grid action is impartial to the polarity of the charged particles and, accordingly. the sheath effects encountered with electrostatic grids are not present. The grid comprises a conductor having sections spaced apart and extending in substantially opposite directions in the same plane, the ends of the conductor being adapted for connection to a current source.

Post, R.F.

1960-08-01T23:59:59.000Z

190

Ground State Magnetic Moments of Mirror Nuclei Studied at NSCL  

E-Print Network (OSTI)

Progress in the measurement of the ground state magnetic moments of mirror nuclei at NSCL is presented. The systematic trend of the spin expectation value $$ and the linear behavior of $\\gamma_p$ versus $\\gamma_n$, both extracted from the magnetic moments of mirror partners, are updated to include all available data.

P. F. Mantica; K. Minamisono

2009-01-22T23:59:59.000Z

191

Reference variables generation using a fuzzy trajectory controller for PM tubular linear synchronous motor drive  

Science Conference Proceedings (OSTI)

The usage of linear permanent-magnet (PM) actuators, and their associated controllers, increases in a wide variety of applications, due to the exhibited high force density, robustness, and accuracy. The s-curve motion profiling is the motion trajectory ... Keywords: fuzzy logic control, modelling and simulation, trajectory tracking

R. Lus; J. C. Quadrado

2005-06-01T23:59:59.000Z

192

Questions about Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

off just the north (or just the south) end of a magnet? Are magnets stronger than gravity? Hold a magnet in the air. Place a nail against it. The magnet holds the nail up...

193

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation  

E-Print Network (OSTI)

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation Shan to regulate the speed of a permanent magnet synchronous motor where the design is based on a linearized state rejection, constraints, quadratic programming. 1. Introduction Permanent Magnet Synchronous Motors (PMSMs

194

magnets2  

NLE Websites -- All DOE Office Websites (Extended Search)

II II Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

195

Magnetic Reconnection  

SciTech Connect

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.

Masaaki Yamada, Russell Kulsrud and Hantao Ji

2009-09-17T23:59:59.000Z

196

Improved Linear Programming Decoding using Frustrated Cycles  

E-Print Network (OSTI)

We consider transmission over a binary-input additive white Gaussian noise channel using low-density parity-check codes. One of the most popular techniques for decoding low-density parity-check codes is the linear programming decoder. In general, the linear programming decoder is suboptimal. I.e., the word error rate is higher than the optimal, maximum a posteriori decoder. In this paper we present a systematic approach to enhance the linear program decoder. More precisely, in the cases where the linear program outputs a fractional solution, we give a simple algorithm to identify frustrated cycles which cause the output of the linear program to be fractional. Then adding these cycles, adaptively to the basic linear program, we show improved word error rate performance.

Kudekar, Shrinivas; Chertkov, Misha

2011-01-01T23:59:59.000Z

197

Dynamic Linear Production Games under Uncertainty  

E-Print Network (OSTI)

Oct 2, 2013 ... Abstract: In situations where uncertain costs are shared over time, static ... under uncertainty, generalizing classical linear production games to...

198

Siting the International Linear Collider at Hanford  

SciTech Connect

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.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-03-15T23:59:59.000Z

199

Siting the International Linear Collider at Hanford  

SciTech Connect

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.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-05-01T23:59:59.000Z

200

An Adaptive Linear Approximation Algorithm for Copositive ...  

E-Print Network (OSTI)

linear algebra literature (a good survey is [1]), but the optimization community has only recently .... relations v ? 0 and M ? 0 will be understood entrywise.

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Subcritical Fission Reactor Based on Linear Collider  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an accelerator--driven sub--critical reactor.

I. F. Ginzburg

2005-07-29T23:59:59.000Z

202

18.06 Linear Algebra, Fall 2002  

E-Print Network (OSTI)

Basic subject on matrix theory and linear algebra, emphasizing topics useful in other disciplines, including systems of equations, vector spaces, determinants, eigenvalues, similarity, and positive definite matrices. ...

Strang, Gilbert

203

Magnetic positioner having a single moving part  

DOE Patents (OSTI)

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.

Trumper, David L. (Plaistow, NH); Kim, Won-Jong (Cambridge, MA)

1999-01-01T23:59:59.000Z

204

n-Linear Algebra of type II  

E-Print Network (OSTI)

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.

W. B. Vasantha Kandasamy; Florentin Smarandache

2009-02-01T23:59:59.000Z

205

International linear collider reference design report  

E-Print Network (OSTI)

Klystron A pk Pulse transformer average power output @ 5 Hzclosed loop. A LV transformer provides power in the shaftmodulators, pulse transformers); dc magnet power supplies;

Aarons, G.

2008-01-01T23:59:59.000Z

206

Theory of magnetization transport in a spatially varying magnetic field derived from entropic considerations  

E-Print Network (OSTI)

A theory of magnetization transport of a single spin-species in a spatially varying magnetic field is derived from entropic considerations. The theory describes thermodynamic transport in the language of differential geometry. Both magnetization diffusion and separation are predicted from a sample geometry, a magnetic field geometry, an entropy density function, and a single space-time scale. It is expressed first and most generally as coupled nonlinear partial differential equations, which are valid for the regime of high dipole-energy and magnetization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the SMT parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is derived, and is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield. Differences among the three models are illustrated by numerical solution. A family of analytic, steady-state solutions to the nonlinear transport equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. A steady-state solution for the magnetization is shown to be equivalent to the widely applied separation equation of Fenske. Moreover, we show that the SMT parameter is functionally related to the relative volatility parameter of Fenske.

Rico A. R. Picone; Joseph L. Garbini; John A. Sidles

2013-10-28T23:59:59.000Z

207

On the representation by linear superpositions  

Science Conference Proceedings (OSTI)

In a number of papers, Y. Sternfeld investigated the problems of representation of continuous and bounded functions by linear superpositions. In particular, he proved that if such representation holds for continuous functions, then it holds for bounded ... Keywords: 26B40, 41A05, 41A63, Closed path, Linear superposition, Ridge function

Vugar E. Ismailov

2008-04-01T23:59:59.000Z

208

Branching vs. Linear Time: Final Showdown  

Science Conference Proceedings (OSTI)

The discussion of the relative merits of linear- versus branching-time frameworks goes back to early 1980s. One of the beliefs dominating this discussion has been that "while specifying is easier in LTL (linear-temporal logic), verification is easier ...

Moshe Y. Vardi

2001-04-01T23:59:59.000Z

209

Exact acceleration of linear object detectors  

Science Conference Proceedings (OSTI)

We describe a general and exact method to considerably speed up linear object detection systems operating in a sliding, multi-scale window fashion, such as the individual part detectors of part-based models. The main bottleneck of many of those systems ... Keywords: linear object detection, part-based models

Charles Dubout; Fran$#231;ois Fleuret

2012-10-01T23:59:59.000Z

210

Smart Suspension System for Linear Guideways  

Science Conference Proceedings (OSTI)

This paper presents a new method for the semi-active control of the span system of linear guideways subjected to a travelling load. Two elastic beams are coupled by a set of controlled dampers. The relative velocity of the spans provides an opportunity ... Keywords: Linear guideway, Moving load, Semi-active control, Smart suspension system, Vibration control

Dominik Pisarski; Czeslaw I. Bajer

2011-06-01T23:59:59.000Z

211

Weighted locally linear embedding for dimension reduction  

Science Conference Proceedings (OSTI)

The low-dimensional representation of high-dimensional data and the concise description of its intrinsic structures are central problems in data analysis. In this paper, an unsupervised learning algorithm called weighted locally linear embedding (WLLE) ... Keywords: Feature extraction, Locally linear embedding, Manifold learning, Nonlinear dimensionality reduction

Yaozhang Pan; Shuzhi Sam Ge; Abdullah Al Mamun

2009-05-01T23:59:59.000Z

212

On linear models for nonlinear systems  

Science Conference Proceedings (OSTI)

Best linear time-invariant (LTI) approximations are analysed for several interesting classes of discrete nonlinear time-invariant systems. These include nonlinear finite impulse response systems and a class of nonsmooth systems called bi-gain systems. ... Keywords: Approximation, Discrete-time systems, Frchet derivative, Linear models, Nonlinear systems, System identification, Wiener systems

P. M. MKil; J. R. Partington

2003-01-01T23:59:59.000Z

213

Piecewise Linear Modeling: Theory, Guidelines, and Applications  

E-Print Network (OSTI)

Statistical analysis underlies most published research in every scientific field of study. A common statistical tool for the analysis of cross-sectional data is the general linear model, or multiple regression. For the analysis of time series data, the most commonly employed tool is autoregressive integrated moving averages (ARIMA), which also is implicitly linear.

Kenneth O. Cogger

2006-01-01T23:59:59.000Z

214

Independent Oversight Inspection, Stanford Linear Accelerator Center -  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stanford Linear Accelerator Stanford Linear Accelerator Center - January 2007 Independent Oversight Inspection, Stanford Linear Accelerator Center - January 2007 January 2007 Inspection of Environment, Safety, and Health Programs at the Stanford Linear Accelerator Center The U.S. Department of Energy (DOE) Office of Independent Oversight, within the Office of Health, Safety and Security, conducted an inspection of environment, safety, and health (ES&H) programs at the DOE Stanford Linear Accelerator Center (SLAC) during October and November 2006. The inspection was performed by Independent Oversight's Office of Environment, Safety and Health Evaluations. Since the 2004 Type A electrical accident, SSO and SLAC have made improvements in many aspects of ES&H programs. However, the deficiencies in

215

Superconducting magnet  

DOE Patents (OSTI)

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.

Satti, John A. (Naperville, IL)

1980-01-01T23:59:59.000Z

216

Magnet innovations for linacs  

Science Conference Proceedings (OSTI)

It is possible to produce large magnetic fields at the aperture of permanent magnet quadrupoles, even when the magnetic aperture is very small. That, combined with their compactness, makes permanent magnet quadrupoles very powerful components of small aperture linacs. Results will be presented about past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs.

Halbach, K.

1986-06-01T23:59:59.000Z

217

On the Relative Performance of Linear vs. Piecewise-Linear-Threshold Intertemporal Incentives  

Science Conference Proceedings (OSTI)

This paper employs numerical simulations to compare the relative performance of linear contracts with piecewise-linear-threshold contracts in the case where the agent chooses actions over time. These contracts are restricted to be functions of the ending ... Keywords: dynamic programming, intertemporal incentives, linear contracts, salesforce compensation

Joseph Y. Chen; Bruce L. Miller

2009-10-01T23:59:59.000Z

218

Linear reachability problems and minimal solutions to linear Diophantine equation systems  

Science Conference Proceedings (OSTI)

The linear reachability problem for finite state transition systems is to decide whether there is an execution path in a given finite state transition system such that the counts of labels on the path satisfy a given linear constraint. Using some known ... Keywords: linear diophantine equation systems, minimal solutions, model-checking, reachability, timed automata

Gaoyan Xie; Cheng Li; Zhe Dang

2004-11-01T23:59:59.000Z

219

Magnetics and the body  

NLE Websites -- All DOE Office Websites (Extended Search)

no magnetic "charges"), such as from electromagnets. Magnetic fields are measured in Tesla (T) or Gauss (G). The Tesla is a very large unit (1 T 10,000 G). Most large magnets...

220

Learning About Magnets!  

NLE Websites -- All DOE Office Websites (Extended Search)

the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a force...

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

ALS superbend magnet system  

E-Print Network (OSTI)

ALS Superbend Magnet System J. Zbasnik , S. T. Wang ,of a High-Field Magnet for the ALS, Transactions AppliedRefrigeration options for the ALS Superbend dipole magnets,

2000-01-01T23:59:59.000Z

222

Linear Collider Collaboration Tech Notes LCC-0104  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 October 2002 Beamstrahlung Photon Load on the TESLA Extraction Septum Blade Andrei Seryi Stanford Linear Accelerator Center Stanford, CA 94309, USA Abstract: This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design. Beamstrahlung Photon Load on the TESLA Extraction Septum Blade ANDREI SERYI STANFORD LINEAR

223

Optically isolated signal coupler with linear response  

DOE Patents (OSTI)

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.

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

224

Helical Magnets Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC, the basic construction unit is a superconducting dipole magnet producing a four tesla dipole field that rotates through 360 degrees in a length of 2.4 meters. The magnets...

225

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances

Hassenzahl, W.

2011-01-01T23:59:59.000Z

226

Magnetization of neutron matter  

SciTech Connect

In this paper, we compute magnetization of neutron matter at strong magnetic field using the lowest order constrained variational (LOCV) technique.

Bigdeli, M. [Department of Physics, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

2011-09-21T23:59:59.000Z

227

Regenerator for Magnetic Refrigerants  

Ames Laboratory researchers have developed a new magnetic material that can be used at low temperatures (sub liquid hydrogen) for magnetic refrigerators.

228

Magnetic Materials Group Homepage  

Science Conference Proceedings (OSTI)

... and simulation to become the driving force in ... develop a real-time magnetic domain imaging ... data-storage and permanent magnets with increased ...

2012-12-03T23:59:59.000Z

229

NSLS II: Magnetism  

NLE Websites -- All DOE Office Websites (Extended Search)

spatial ordering of the magnetic moments that is superimposed on the crystal lattice. Why these atomic magnetic moments survive and how they arrange in the solid is the...

230

Linear Anelastic Equations for Atmospheric Vortices  

Science Conference Proceedings (OSTI)

A linear anelastic-vortex model is derived using assumptions appropriate to waves on vortices with scales similar to tropical cyclones. The equation set is derived through application of a multiple-scaling technique, such that the radial ...

Daniel Hodyss; David S. Nolan

2007-08-01T23:59:59.000Z

231

Fun with sub-linear time algorithms  

Science Conference Proceedings (OSTI)

Provided that one is willing to use randomness and to tolerate an approximate answer, many computational problems admit ultrafast algorithms that run in less than linear time in the length of the input. In many interesting cases, even algorithms that ...

Luca Trevisan

2007-06-01T23:59:59.000Z

232

Linear Concentrator Systems | Open Energy Information  

Open Energy Info (EERE)

Linear Concentrator Systems Linear Concentrator Systems Jump to: navigation, search Introduction Linear concentrating collector fields consist of a large number of collectors in parallel rows that are typically aligned in a north-south orientation to maximize both annual and summertime energy collection. With a single-axis sun-tracking system, this configuration enables the mirrors to track the sun from east to west during the day, ensuring that the sun reflects continuously onto the receiver tubes. Parabolic Trough Systems The predominant CSP systems currently in operation in the United States are linear concentrators using parabolic trough collectors. In such a system, the receiver tube is positioned along the focal line of each parabola-shaped reflector. The tube is fixed to the mirror structure and

233

18.06 Linear Algebra, Spring 2005  

E-Print Network (OSTI)

This is a basic subject on matrix theory and linear algebra. Emphasis is given to topics that will be useful in other disciplines, including systems of equations, vector spaces, determinants, eigenvalues, similarity, and ...

Strang, Gilbert

234

Linear Prediction of Indian Monsoon Rainfall  

Science Conference Proceedings (OSTI)

This paper proposes a strategy for selecting the best linear prediction model for Indian monsoon rainfall. In this strategy, a cross-validation procedure first screens out all models that perform poorly on independent data, then the error ...

Timothy DelSole; J. Shukla

2002-12-01T23:59:59.000Z

235

General linear cameras : theory and applications  

E-Print Network (OSTI)

I present a General Linear Camera (GLC) model that unifies many previous camera models into a single representation. The GLC model describes all perspective (pinhole), orthographic, and many multiperspective (including ...

Yu, Jingyi, 1978-

2005-01-01T23:59:59.000Z

236

EOF-Based Linear Prediction Algorithm: Theory  

Science Conference Proceedings (OSTI)

This study considers the theory of a general three-dimensional (space and time) statistical prediction/extrapolation algorithm. The predictor is in the form of a linear data filter. The prediction kernel is based on the minimization of prediction ...

Kwang-Y. Kim; Gerald R. North

1998-11-01T23:59:59.000Z

237

Linear Thermodynamics of Rodlike DNA Filtration  

E-Print Network (OSTI)

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 ...

Li, Zirui

238

Linear Baroclinic Instability in the Martian Atmosphere  

Science Conference Proceedings (OSTI)

The linear baroclinic instability of zonal-mean flows like those in the wintertime Martian atmosphere under both relatively nondusty and highly dusty conditions is examined using a spherical quasi-geostrophic model. The basic states are idealized,...

Jeffrey R. Barnes

1984-05-01T23:59:59.000Z

239

PERVASIVE LINEAR POLARIZATION SIGNALS IN THE QUIET SUN  

Science Conference Proceedings (OSTI)

This paper investigates the distribution of linear polarization signals in the quiet-Sun internetwork using ultra-deep spectropolarimetric data. We reduce the noise of the observations as much as is feasible by adding single-slit measurements of the Zeeman-sensitive Fe I 630 nm lines taken by the Hinode spectropolarimeter. The integrated Stokes spectra are employed to determine the fraction of the field of view covered by linear polarization signals. We find that up to 69% of the quiet solar surface at disk center shows Stokes Q or U profiles with amplitudes larger than 0.032% (4.5 times the noise level of 7 Multiplication-Sign 10{sup -5} reached by the longer integrations). The mere presence of linear polarization in most of the quiet Sun implies that the weak internetwork fields must be highly inclined, but we quantify this by inverting those pixels with Stokes Q or U signals well above the noise. This allows for a precise determination of the field inclination, field strength, and field azimuth because the information carried by all four Stokes spectra is used simultaneously. The inversion is performed for 53% of the observed field of view at a noise level of 1.3 Multiplication-Sign 10{sup -4} I{sub c}. The derived magnetic distributions are thus representative of more than half of the quiet-Sun internetwork. Our results confirm the conclusions drawn from previous analyses using mainly Stokes I and V: internetwork fields are very inclined, but except in azimuth they do not seem to be isotropically distributed.

Bellot Rubio, L. R. [Instituto de Astrofisica de Andalucia (CSIC), Apdo. 3004, E-18080 Granada (Spain); Orozco Suarez, D., E-mail: lbellot@iaa.es [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2012-09-20T23:59:59.000Z

240

A linear program for testing local realism  

E-Print Network (OSTI)

We present a linear program that is capable of determining whether a set of correlations can be captured by a local realistic model. If the correlations can be described by such a model, the linear program outputs a joint probability distribution that produces the given correlations. If the correlations cannot be described under the assumption of local realism, the program outputs a Bell inequality violated by the correlations.

Matthew B. Elliott

2009-05-18T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Complex bodies with memory: linearized setting  

E-Print Network (OSTI)

The mechanics of complex bodies with memory effects is discussed in linearized setting. The attention is focused on the characterization of free energies in terms of minimum work and maximum recoverable work in the bulk and along a discontinuity surface endowed with its own surface energy, a surface internal to the body. To this aim, use is made of techniques proposed by Del Piero. Consequences of the Clausius-Duhem inequality are investigated for complex bodies with instantaneous linear elastic response.

Paolo Maria Mariano; Paolo Paoletti

2008-05-28T23:59:59.000Z

242

Photon Linear Collider Gamma-Gamma Summary  

SciTech Connect

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.

Gronberg, J

2012-02-27T23:59:59.000Z

243

Ferrofluid spin-up flows from uniform and non-uniform rotating magnetic fields  

E-Print Network (OSTI)

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 ...

Khushrushahi, Shahriar Rohinton

2010-01-01T23:59:59.000Z

244

Lecture Notes on Classical Linear Logic 15-816: Linear Logic  

E-Print Network (OSTI)

Originally, linear logic was conceived by Girard [Gir87] as a classical system, with one-sided sequents, an involutive negation, and an appropriate law of excluded middle. For a number of the applications, such as functional computation, logic programming, and implicit computational complexity the intuitionistic version is more suitable. In the case of concurrent computation, both classical and intuitionistic systems may be used, although the additional expressiveness afforded by the intuitionistic system seems to have some advantages even in that setting. In this lecture we present classical linear logic and then show that we can easily interpret it intuitionistically. Briefly, classical linear logic can be modeled intuitionistically as deriving a contradiction from linear assumptions. This is shown via a so-called double-negation translation. Its parametric nature allows a number of additional variants of classical linear logic to be explained intuitionistically, in particular the so-called mix rules. 1 Classical Linear Sequents

Frank Pfenning

2012-01-01T23:59:59.000Z

245

Use of miniature magnetic sensors for real-time control of the induction heating process  

DOE Patents (OSTI)

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).

Bentley, Anthony E. (Tijeras, NM); Kelley, John Bruce (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

246

Non-linear dynamic of rotor-stator system with non-linear bearing clearance  

E-Print Network (OSTI)

The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

Jean-Jacques Sinou; Fabrice Thouverez

2008-01-19T23:59:59.000Z

247

Non-linear dynamic of rotor-stator system with non-linear bearing clearance  

E-Print Network (OSTI)

The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

Sinou, Jean-Jacques

2008-01-01T23:59:59.000Z

248

Linear Collider Collaboration Tech Notes LCC-0100  

NLE Websites -- All DOE Office Websites (Extended Search)

100 100 August 2002 Systematic Ground Motion and Macroalignment for Linear Colliders Rainer Pitthan Stanford Linear Accelerator Center Stanford University Stanford, CA 94309, USA Abstract: Future colliders with their µm-range operational tolerances still need to be classically aligned to the 50 - 100 µm range, and kept there, over the km range. This requirement will not be a show-stopper, but not be trivial either. 50 µm movements over a betatron wavelength is a the range where systematic long term motions can prevent efficient operation. Systematic Ground Motion and Macro-Alignment for Linear Colliders Complete talk at: http://www-project.slac.stanford.edu/lc/wkshp/snowmass2001/t6/info/pitthan july

249

Piecewise linear car-following modeling  

E-Print Network (OSTI)

We present a traffic model which extends the linear car-following model as well as the min-plus traffic model (a model based on the min-plus algebra). A discrete-time car-dynamics describing the traffic on a 1-lane road without passing is interpreted as a dynamic programming equation of a stochastic optimal control problem of a Markov chain. This variational formulation permits to characterize the stability of the car-dynamics and to calculte the stationary regimes when they exist. The model is based on a piecewise linear approximation of the fundamental traffic diagram.

Farhi, Nadir

2011-01-01T23:59:59.000Z

250

HTS Magnet Program | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

HTS Magnet Program HTS Magnet Program High Temperature Superconductors (HTS) have the potential to revolutionize the field of superconducting magnets for particle accelerators, energy storage and medical applications. This is because of the fact that as compared to the conventional Low Temperature Superconductors (LTS), the critical current density (Jc ) of HTS falls slowly both: as a function of increasing field, and as a function of increasing temperature These unique properties can be utilized to design and build: HTS magnets that produce very high fields (20 - 50 T) HTS magnets that operate at elevated temperatures (20 - 77 K) This is a significant step forward over the convention LTS magnets which generally operate at a temperature of ~4 K and with field usually limited

251

Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets  

SciTech Connect

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.

None

2010-10-01T23:59:59.000Z

252

LINEAR TO NON-LINEAR RHEOLOGY OF WHEAT FLOUR DOUGH TREVOR S.K. NG1  

E-Print Network (OSTI)

LINEAR TO NON-LINEAR RHEOLOGY OF WHEAT FLOUR DOUGH TREVOR S.K. NG1 , GARETH H. MCKINLEY1 *, MADESH.9.2006 Abstract: We provide an overview of transient extensional rheometry techniques for wheat flour doughs wheat flour; mixed to a constant time (360 s/peak-mixed) and a fixed water ratio by weight (66

253

Specification-guided controller synthesis for linear systems and safe linear-time temporal logic  

Science Conference Proceedings (OSTI)

In this paper we present and analyze a novel algorithm to synthesize controllers enforcing linear temporal logic specifications on discrete-time linear systems. The central step within this approach is the computation of the maximal controlled invariant ... Keywords: controller synthesis, robustness

Matthias Rungger; Manuel Mazo, Jr.; Paulo Tabuada

2013-04-01T23:59:59.000Z

254

Modelagem e anlise de um compressor linear para refrigerao domstica.  

E-Print Network (OSTI)

??Compressores lineares utilizam um atuador linear para acionar o pisto diretamente em seu movimento alternativo, eliminando vrios mancais que convertem o movimento rotativo em alternativo (more)

Emlio Rodrigues Hlse

2008-01-01T23:59:59.000Z

255

2011 Annual Planning Summary for Stanford Linear Accelerator...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stanford Linear Accelerator Center Site Office (SLAC) 2011 Annual Planning Summary for Stanford Linear Accelerator Center Site Office (SLAC) The ongoing and projected Environmental...

256

Physics 321 Linear Momentum and Its Conservation  

E-Print Network (OSTI)

Physics 321 Hour 5 Linear Momentum and Its Conservation Four kinds of "collisions" · Elastic: T conserved · Inelastic: some energy loss · Totally inelastic: objects stick ­ maximum energy loss ­ energy inelastic collision timereversed Momentum Conservation In what collisions can you apply momentum

Hart, Gus

257

Linear rotation-invariant coordinates for meshes  

Science Conference Proceedings (OSTI)

We introduce a rigid motion invariant mesh representation based on discrete forms defined on the mesh. The reconstruction of mesh geometry from this representation requires solving two sparse linear systems that arise from the discrete forms: the first ... Keywords: local frames, mesh editing, rigid-motion invariant shape representation, shape blending

Yaron Lipman; Olga Sorkine; David Levin; Daniel Cohen-Or

2005-07-01T23:59:59.000Z

258

Optimal aggregation of linear time series models  

Science Conference Proceedings (OSTI)

Aggregation is a central and mainly unsolved problem in econometrics. When considering linear time series models, a widely used method is to replace the disaggregate model by an aggregative one in which the variables are grouped and replaced by sums ... Keywords: Aggregation, Industrial classification, Threshold accepting

J. Chipman; P. Winker

2005-04-01T23:59:59.000Z

259

DARK ENERGY AND NONLINEAR PERTURBATIONS  

E-Print Network (OSTI)

Dark energy might have an influence on the formation of nonlinear structures during the cosmic history. For example, in models in which dark energy couples to dark matter, it will be nonhomogeneous and will influence on the collapse of a dark matter overdensity. We use the spherical collapse model to estimate how much influence dark energy might have. 1.

C. Van; De Bruck; D. F. Mota

2005-01-01T23:59:59.000Z

260

Dark Energy and Non-linear Perturbations  

E-Print Network (OSTI)

Dark energy might have an influence on the formation of non--linear structures during the cosmic history. For example, in models in which dark energy couples to dark matter, it will be non--homogeneous and will influence the collapse of a dark matter overdensity. We use the spherical collapse model to estimate how much influence dark energy might have.

C. van de Bruck; D. F. Mota

2005-01-14T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Can linear approximation improve performance prediction ?  

Science Conference Proceedings (OSTI)

Software performance evaluation relies on the ability of simple models to predict the performance of complex systems. Often, however, the models are not capturing potentially relevant effects in system behavior, such as sharing of memory caches or sharing ... Keywords: linear models, performance modeling, resource sharing

Vlastimil Babka; Petr T?ma

2011-10-01T23:59:59.000Z

262

Linear Response of Metals Within TDCDFT  

E-Print Network (OSTI)

Linear Response of Metals Within TDCDFT Pina Romaniello Theoretical Chemistry, Material Science Results Conclusions #12;extended systems Emac(r, t) = 1 |r| r (Eext (r , t) + Eind (r , t)) dr Pmac(r, t) = - 1 |r| t r j(r , t )dr dt ! Macroscopic field and polarization ! Response to transverse fields

Giraud, Olivier

263

Constructing Uncertainty Sets for Robust Linear Optimization  

Science Conference Proceedings (OSTI)

In this paper, we propose a methodology for constructing uncertainty sets within the framework of robust optimization for linear optimization problems with uncertain parameters. Our approach relies on decision maker risk preferences. Specifically, we ... Keywords: coherent risk measures, distortion risk measures, robust optimization, uncertainty sets

Dimitris Bertsimas; David B. Brown

2009-11-01T23:59:59.000Z

264

Stability analysis of switched linear singular systems  

Science Conference Proceedings (OSTI)

This paper addresses the stability analysis problem for switched linear continuous-time singular systems. First, based on the equivalent dynamics decomposition form, a refined description for state jumps of the switched singular system is presented, ... Keywords: Average dwell time, Exponential stability, State jumps, Switched singular systems

Lei Zhou, Daniel W. C. Ho, Guisheng Zhai

2013-05-01T23:59:59.000Z

265

On linear combinations of -terms Lionel Vaux  

E-Print Network (OSTI)

On linear combinations of -terms Lionel Vaux Institut de Math´ematiques de Luminy, CNRS UMR 6206, endowing the set of terms with a structure of R-module, where R is a fixed set of scalars. Terms with values in a vector space. We then extend -reduction on those algebraic -terms as follows: at + u reduces

Paris-Sud XI, Université de

266

Multi-label linear discriminant analysis  

Science Conference Proceedings (OSTI)

Multi-label problems arise frequently in image and video annotations, and many other related applications such as multi-topic text categorization, music classification, etc. Like other computer vision tasks, multi-label image and video annotations also ... Keywords: image annotation, multi-label classification, multi-label linear discriminant analysis

Hua Wang; Chris Ding; Heng Huang

2010-09-01T23:59:59.000Z

267

Dirichlet Process Mixtures of Generalized Linear Models  

Science Conference Proceedings (OSTI)

We propose Dirichlet Process mixtures of Generalized Linear Models (DP-GLM), a new class of methods for nonparametric regression. Given a data set of input-response pairs, the DP-GLM produces a global model of the joint distribution through a mixture ...

Lauren A. Hannah; David M. Blei; Warren B. Powell

2011-02-01T23:59:59.000Z

268

COLIN: planning with continuous linear numeric change  

Science Conference Proceedings (OSTI)

In this paper we describe COLIN, a forward-chaining heuristic search planner, capable of reasoning with COntinuous LINear numeric change, in addition to the full temporal semantics of PDDL2.1. Through this work we make two advances to the state-of-the-art ...

Amanda Coles; Andrew Coles; Maria Fox; Derek Long

2012-05-01T23:59:59.000Z

269

A general approach to heteroscedastic linear regression  

Science Conference Proceedings (OSTI)

Our article presents a general treatment of the linear regression model, in which the error distribution is modelled nonparametrically and the error variances may be heteroscedastic, thus eliminating the need to transform the dependent variable in many ... Keywords: Density estimation, Dirichlet process mixture, Heteroscedasticity, Model checking, Nonparametric regression, Variable selection

David S. Leslie; Robert Kohn; David J. Nott

2007-06-01T23:59:59.000Z

270

Tamper resistant magnetic stripes  

DOE Patents (OSTI)

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.

Naylor, Richard Brian (Albuquerque, NM); Sharp, Donald J. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

271

Magnet reliability in the Fermilab Main Injector and implications for the ILC  

Science Conference Proceedings (OSTI)

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.

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

272

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

273

The neutrino self-energy in a magnetized medium  

E-Print Network (OSTI)

In this work we calculate the neutrino self-energy in presence of a magnetized medium. The magnetized medium consists of electrons, positrons, neutrinos and a uniform classical magnetic field. The calculation is done assuming the background magnetic field is weak compared to the $W$-Boson mass squared, as a consequence of which only linear order corrections in the field are included in the $W$ boson propagator. The electron propagator consists all order corrections in the background field. Although the neutrino self-energy in a magnetized medium in various limiting cases has been calculated previously in this article we produce the most general expression of the self-energy in absence of the Landau quantization of the charged gauge fields. We calculate the effect of the Landau quantization of the charged leptons on the neutrino self-energy in the general case. Our calculation is specifically suited for situations where the background plasma may be CP symmetric.

Alberto Bravo Garcia; Kaushik Bhattacharya; Sarira Sahu

2007-06-27T23:59:59.000Z

274

Performance of An Adjustable Strength Permanent Magnet Quadrupole  

SciTech Connect

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.

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

275

Molecular gyroscopes and biological effects of weak ELF magnetic fields  

E-Print Network (OSTI)

Extremely-low-frequency magnetic fields are known to affect biological systems. In many cases, biological effects display `windows' in biologically effective parameters of the magnetic fields: most dramatic is the fact that relatively intense magnetic fields sometimes do not cause appreciable effect, while smaller fields of the order of 10--100 $\\mu$T do. Linear resonant physical processes do not explain frequency windows in this case. Amplitude window phenomena suggest a nonlinear physical mechanism. Such a nonlinear mechanism has been proposed recently to explain those `windows'. It considers quantum-interference effects on protein-bound substrate ions. Magnetic fields cause an interference of ion quantum states and change the probability of ion-protein dissociation. This ion-interference mechanism predicts specific magnetic-field frequency and amplitude windows within which biological effects occur. It agrees with a lot of experiments. However, according to the mechanism, the lifetime $\\Gamma^{-1}$ of ion ...

Savin, A V

2002-01-01T23:59:59.000Z

276

LHC Magnet Program | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnet Program Magnet Program The Superconducting Magnet Division is building a number of dipole magnets for the Large Hadron Collider (LHC), which is now under construction at CERN in Geneva, Switzerland. Scheduled to begin operation in 2007, this machine will collide beams of protons with the unprecedented energy of 7 TeV per beam to explore the nature of matter at its most basic level (RHIC can collide beams of protons with energies of 0.25 TeV, but is mostly used to collide heavy ions with energies of 0.1 TeV per nucleon). The magnets are being built as part of the US program, recommended by the High Energy Physics Advisory Panel (HEPAP) and approved by Congress, to contribute to the construction and, later, use of that frontier machine by the US high energy physics community. Fermi National Accelerator Laboratory (FNAL) and

277

Active magnetic regenerator  

SciTech Connect

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.

Barclay, John A. (Los Alamos, NM); Steyert, William A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

278

ALS superbend magnet performance  

E-Print Network (OSTI)

ALS Superbend Magnet Performance S. Marks, J. Zbasnik, W.the Advanced Light Source (ALS), with the fourth magnet as ahe Advanced Light Source (ALS) at the Lawrence Berkeley

2001-01-01T23:59:59.000Z

279

An Improved Sensorless Control System of Permanent Magnet Synchronous Motor  

Science Conference Proceedings (OSTI)

To improve the performance of permanent magnet synchronous motor sensor less control system, the phase offset caused by the low pass filter must be considering. In this paper, to apply the linear control theory to PMSM system. The introduced control ... Keywords: PMSM, Reduced-order Observer, Group Time Delay, Adaptive, Sensorless

Long Tang, Hong-Lin Ou Yang, Chao Meng, Xin-Yuan Li, Xu-Jie Mo

2013-01-01T23:59:59.000Z

280

Triggering for Magnetic Field Measurements of the LCLS Undulators  

Science Conference Proceedings (OSTI)

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.

Hacker, Kirsten

2010-12-13T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Magnetic Materials Staff  

Science Conference Proceedings (OSTI)

... Materials Science and Engineering Division Staff Directory; MML Organization. Contact. Magnetic Materials Group Robert Shull, Group Leader. ...

2012-10-09T23:59:59.000Z

282

Minimum Magnetic Energy Theorem  

E-Print Network (OSTI)

The Thomson's Theorem states that static charge distributions in conductors show up at the conducting surfaces in an equipotential configuration, so that the electrostatic energy is a minimum. In this work we study an analogue statement for magnetic systems: in a given set of conductors, the stored magnetic field energy reaches the minimum value for superficial current distributions so that the magnetic vector potential is tangent to the conductors surfaces. This is the counterpart of Thomson's theorem for the magnetic field.

Fiolhais, M C N

2008-01-01T23:59:59.000Z

283

Superconducting magnet of Aurora  

Science Conference Proceedings (OSTI)

The AURORAsuperconducting magnet system is composed of a cylindrical single?body magnet and a refrigeration system for superconducting coils. The magnet generates B z =1 T on the central orbit at the 150 MeV electron beam injection energy and B z =4.3 T at the 650 MeV storage energy. The diameter of the central orbit is 1 m. Iron poles and yokes are used for shielding the magnetic field

T. Takayama; SHI Accelerator Research Group

1989-01-01T23:59:59.000Z

284

Irreversible magnetic switch  

DOE Patents (OSTI)

This invention is comprised of an irreversible magnetic switch containing a ferromagnetic amorphous metal having a predetermined crystallization temperature in its inductor magnetic path. With the incorporation of such material, the magnetic properties after cooling from a high temperature excursion above its crystallization temperature are only a fraction of the original value. The difference is used to provide a safety feature in the magnetic switch.

Karnowsky, M.M.; Yost, F.G.

1991-12-31T23:59:59.000Z

285

Magnetic Nanoparticle Metrology  

Science Conference Proceedings (OSTI)

... T2 relaxation times, hysteretic energy loss, etc ... Optimization of magnetic nanoparticle synthesis for ... competition between lattice energies and dipolar ...

2012-12-03T23:59:59.000Z

286

Magnetic nanohole superlattices  

DOE Patents (OSTI)

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.

Liu, Feng

2013-05-14T23:59:59.000Z

287

Tunable Magnetic Regenerator/Refrigerant  

Magnetic regenerators utilize the magnetocaloric effect--the ability of a magnetic field to reduce the magnetic part of a solid materials entropy, generating heat, and then removing the magnetic field, permitting the reduction of temperature with the ...

288

Observation of low magnetic field density peaks in helicon plasma  

SciTech Connect

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.

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

289

Automatic tuning for linearly tunable filter  

E-Print Network (OSTI)

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 magnitude and Q. A gm-C biquadratic filter is designed to demonstrate the proposed tuning circuitry. The project includes a phase locked loop (PLL) based frequency tuning loop, reference clock generator, and differential difference amplifier (DDA) for dealing with frequency and Q factor tuning loop and linearly tunable second order gm-C bandpass filter. Simulation results for a 10 MHz prototype filter using AMI 0.5?m process is presented. The chip testing results show that the automatic frequency tuning error is 2.5% for the 10 MHz case.

Huang, Sung-Ling

2003-05-01T23:59:59.000Z

290

Recent Progress in Nonlinear and Linear Solvers  

SciTech Connect

We discuss two approaches for tackling algebraic systems, one is based on block preconditioning and the other is based on multifrontal and hierarchical matrix methods. First we consider a new preconditioner framework for supporting implicit time integration within an atmospheric climate model. We give an overview of the computational infrastructure used in atmospheric climate studies, address specific challenges of weak-scalability of numerical methods used in these codes, outline a strategy for addressing these challenges, and provide details about the software infrastructure being developed to implement these ideas. In the second part, we present our recent results of employing hierarchically semiseparable low-rank structure in a multifrontal factorization framework. This leads to superfast linear solvers for elliptic PDEs and effective preconditioners for a wider class of sparse linear systems.

Lott, P Aaron [Lawrence Livermore National Laboratory (LLNL); Elman, Howard [University of Maryland; Evans, Katherine J [ORNL; Li, X S [Lawrence Berkeley National Laboratory (LBNL); Salinger, Andy [Sandia National Laboratories (SNL); Woodward, Carol [Lawrence Livermore National Laboratory (LLNL)

2011-01-01T23:59:59.000Z

291

Fair SMG and Linear Time Model Checking  

E-Print Network (OSTI)

SMG is a system designed to generate a finite state model of a program from the program itself and an operational semantics for the programming language. This finite state model can then be model-checked to verify desired temporal properties of the original program. In this paper we first show how we have incorporated notions of fairness into SMG; in particular, a user is now able to define semantics with "fair" constructs, for example, parallel, repetitive choice, etc. The user can, indeed, mix different forms of fairness checking. Secondly we describe a practical approach to model checking of linear temporal formulae over the fair structures generated by SMG. Our approach is a refinement and extension of the fair-satisfiability algorithms, presented earlier by Lichtenstein and Pnueli, together with techniques developed in our practical implementations of decision procedures for linear temporal logic.

Howard Barringer; Michael D. Fisher; Graham D. Gough

1989-01-01T23:59:59.000Z

292

Subcritical Fission Reactor Based on Linear  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an acceleratordriven subcritical reactor. ? The project of Linear Collider (LC) contains one essential element that is not present in other colliders. Here each electron (or positron or photon) bunch will be used only once, and physical collision leave two very dense and strongly collimated beams of high energy electrons or/and photons with precisely known time structure. We consider, for definiteness, electron beam parameters of the TESLA project [1] particle energy Ee = 250 GeV, number of electrons per second Ne = 2.7 10 14 /s, mean beam power Pb ? 11 MWt, transverse size and angular spread negligible. (1) In the Photon Collider mode the used beams contain photons, electrons and

I. F. Ginzburg

2005-01-01T23:59:59.000Z

293

Linear source approximation in CASMO5  

Science Conference Proceedings (OSTI)

A Linear Source (LS) approximation has been implemented in the two-dimensional Method of Characteristics (MOC) transport solver in a prototype version of CASMO5. The LS approximation, which relies on the computation of trajectory-based spatial moments over source regions to obtain the linear source expansion coefficients, improves the solution accuracy relative to the 'flat' or constant source approximation. In addition, the LS formulation is capable of treating arbitrarily-shaped source regions and is compatible with standard Coarse-Mesh Finite Difference (CMFD) acceleration. Numerical tests presented in this paper for the C5G7 MOX benchmark show that, for comparable accuracy with respect to the reference solution, the LS approximation can reduce the run time by a factor of four and the memory requirements by a factor often relative to the FS scheme. (authors)

Ferrer, R.; Rhodes, J. [Studsvik Scandpower, Inc., 504 Shoup Ave., Idaho Falls, ID 83402 (United States); Smith, K. [Dept. of Nuclear Science and Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

2012-07-01T23:59:59.000Z

294

An LED pulser for measuring photomultiplier linearity  

E-Print Network (OSTI)

A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 80 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to LED gain drifts. Instead, a finite-difference measurement is made using two LEDs which need not be calibrated with respect to one another. These measurements give a better than 1% mapping of the response function, allowing for the testing and development of particularly linear PMT bases.

Friend, M; Quinn, B

2011-01-01T23:59:59.000Z

295

The explicit linear quadratic regulator for constrained systems  

Science Conference Proceedings (OSTI)

We present a technique to compute the explicit state-feedback solution to both the finite and infinite horizon linear quadratic optimal control problem subject to state and input constraints. We show that this closed form solution is piecewise linear ... Keywords: Constraints, Linear quadratic regulators, Piecewise linear controllers, Predictive control

Alberto Bemporad; Manfred Morari; Vivek Dua; Efstratios N. Pistikopoulos

2002-01-01T23:59:59.000Z

296

Linear control of nearly singularly perturbed hydropower plants  

Science Conference Proceedings (OSTI)

Keywords: linear optimal regulator, order reduction, power station control, recursive algorithms, singular perturbations

Dobrila Skataric; Zoran Gajic

1992-01-01T23:59:59.000Z

297

Linear Representations and Isospectrality with Boundary Conditions  

E-Print Network (OSTI)

We present a method for constructing families of isospectral systems, using linear representations of finite groups. We focus on quantum graphs, for which we give a complete treatment. However, the method presented can be applied to other systems such as manifolds and two-dimensional drums. This is demonstrated by reproducing some known isospectral drums, and new examples are obtained as well. In particular, Sunada's method is a special case of the one presented.

Ori Parzanchevski; Ram Band

2008-06-05T23:59:59.000Z

298

Linearity Testing of Photovoltaic Cells (Poster)  

DOE Green Energy (OSTI)

International PV standards require that the short-circuit current or response of the reference device be linear with total irradiance. Accredited calibration laboratories can not assume that their reference device is linear unless another accredited laboratory has performed the measurement. The NREL PV performance laboratory is ISO 17025 accredited for primary reference cell, secondary reference cell and secondary module calibrations. Limited labor resources necessitated the development of a technique to determine linearity without taking significant labor or technical skill. The two-lamp method is insensitive to the spectrum of the light or spatial nonuniformity changing as the irradiance is varied. It does assume that the temperature does not change with irradiance and that the light-source spectrum resembles the solar spectrum. This requirement is only because nonlinear mechanisms in the photo-current are wavelength dependent. A laser for example may show the same device as linear or very nonlinear with irradiance depending on the wavelength. The two-lamp method assumes that the lamp intensities when individually irradiating the sample are the same as when both lamps irradiate the sample. The presence of room light only limits the lowest irradiance that can be evaluated. Unlike other methods, the two-lamp method does not allow the current to be corrected for nonlinear effects. The most appealing aspect of the two-lamp method when compared with other methods for a high-volume calibration laboratory is that it is fast and does not require operator intervention to change the irradiances and is difficult for the operator to make mistakes that would affect the outcome.

Emery, K.; Winter, S.; Pinegar, S.; Nalley, D.

2006-05-01T23:59:59.000Z

299

Linear conductance through parallel coupled quantum dots  

Science Conference Proceedings (OSTI)

We study the electronic transport through two parallel coupled quantum dots (QDs), employing the X-boson treatment for the single impurity Anderson model. We compute the linear conductance (LC) and transmission coefficient for different regimes of the ... Keywords: 71.10.Ay, 71.27.+a, 73.21.La, 73.23.-b, Fano resonance, Kondo effect, Quantum dot, Transport, X-boson

R. Franco; J. Silva-Valencia; M. S. Figueira

2008-03-01T23:59:59.000Z

300

Heat conductivity in linear mixing systems  

E-Print Network (OSTI)

We present analytical and numerical results on the heat conduction in a linear mixing system. In particular we consider a quasi one dimensional channel with triangular scatterers with internal angles irrational multiples of pi and we show that the system obeys Fourier law of heat conduction. Therefore deterministic diffusion and normal heat transport which are usually associated to full hyperbolicity, actually take place in systems without exponential instability.

Baowen Li; Giulio Casati; Jiao Wang

2002-08-06T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Subsonic Free Surface Waves in Linear Elasticity  

E-Print Network (OSTI)

For general anisotropic linear elastic solids with smooth boundaries, Rayleigh-type surface waves are studied. Using spectral factorizations of matrix polynomials, a self-contained exposition of the case of a homogeneous half-space is given first. The main result is about inhomogeneous anisotropic bodies with curved surfaces. The existence of subsonic free surface waves is shown by giving ray series asymptotic expansions, including formulas for the transport equation.

Snke Hansen

2013-02-20T23:59:59.000Z

302

MEASUREMENT OF LINEAR COUPLING RESONANCE IN RHIC.  

Science Conference Proceedings (OSTI)

Linear coupling is one of the factors that determine beam lifetime in RHIC. The traditional method of measuring the minimum tune separation requires a tune scan and can't be done parasitically or during the acceleration ramp. A new technique of using ac dipoles to measure linear coupling resonance has been developed at RHIC. This method measures the degree of coupling by comparing the amplitude of the horizontal coherent excitation with the amplitude of the vertical coherent excitation if the beam is excited by the vertical AC dipole and vice versa. One advantage of this method is that it can be done without changing tunes from the normal machine working points. In principle, this method can also localize the coupling source by mapping out the coupling driving terms throughout the ring. This is very useful for local decoupling the interaction regions in RHIC. A beam experiment of measuring linear coupling has been performed in RHIC during its 2003 run, and the analysis of the experimental data is discussed in this paper.

BAI,M.PILAT,F.SATOGATA,T.TOMAS,R.

2002-05-12T23:59:59.000Z

303

Linearity Testing of Photovoltaic Cells: Preprint  

DOE Green Energy (OSTI)

Photovoltaic devices are rated in terms of their peak power with respect to a specific spectrum, total irradiance, and temperature. To rate photovoltaic devices, a reference detector is required whose response is linear with total irradiance. This paper describes a procedure to determine the linearity of the short-circuit current (Isc) versus the total irradiance (Etot) by illuminating a reference cell with two lamps. A device is linear if the current measured with both lamps illuminating the cell is the same as the sum of the currents with each lamp illuminating the cell. The two-lamp method is insensitive to the light spectra or spatial nonuniformity changing with irradiance. The two-lamp method is rapid, easy to implement, and does not require operator intervention to change the irradiances. The presence of room light only limits the lowest irradiance that can be evaluated. Unlike other methods, the two-lamp method does not allow the current to be corrected for nonlinear effects.

Emery, K.; Winter, S.; Pinegar, S.; Nalley D.

2006-05-01T23:59:59.000Z

304

Control of nanoparticle size, reactivity and magnetic properties during the bioproduction of magnetite by Geobacter sulfurreducens  

Science Conference Proceedings (OSTI)

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.

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

305

Implicit Methods for the Magnetohydrodynamic Description of Magnetically Confined Plasmas  

SciTech Connect

Implicit algorithms are essential for predicting the slow growth and saturation of global instabilities in todays 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, todays 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.

S.C. Jardin

2010-09-28T23:59:59.000Z

306

Summary of HQ01e magnetic measurements  

SciTech Connect

The magnetic measurements of HQ01e, a 1 m long LHC Accelerator Research Program (LARP) high-gradient quadrupole model, were performed at 4.4 K and above 40 K at the magnet test facility of LBNL in July 2011. The 120 mm aperture cos2? Nb{sub 3}Sn magnet was designed with accelerator magnet features including alignment and field quality. Conductor-limited gradient was 195 T/m at 4.4 K. During the measurement, a ramp rate of 10 A/s was used and measurements at the nominal current of 14.2 kA (82% of short-sample limit with a gradient of 160 T/m) were performed using the 250 mm long printed-circuit board rotating probe developed by FNAL. At 14.2 kA, 2.7 units of b{sub 6} and 0.7 units of b{sub 10} were measured. Large persistent current contribution and strong dynamic effects were observed. We analyzed the allowed and non-allowed harmonics obtained during the measurements above 40 K and at the nominal current. Significant change of the skew sextupole occurred between 50 K and 95 K. The allowed multipole and the low-order non-allowed multipoles at the straight section were explained through the rigid displacement of coil blocks with an amplitude less than 100 ?m. We also attempted to correlate the coil asymmetry (a{sub 3} and b{sub 3}) with the measured coil pole azimuthal strain. The dynamic multipole measured at the magnetic straight section varied linearly with the ramp rate of magnet current ranging from 10 A/s to 60 A/s. It was attributed to the inter-strand coupling currents with low crossover resistance. The crossover resistance of the cables at the inner layer of the magnet was estimated to range between 0.2 ?? to 0.7 ??.

Wang, X.; Caspi, S.; Cheng, D. W.; Dietderich, D. R.; Felice, H.; Ferracin, P.; Godeke, A.; Hafalia, A.R.; Joseph, J. M.; Lizarazo, J.; Marchevsky, M.; Sabbi, G. L.; Ghosh, A.; Schmalzle, J.; Wanderer, P.; Ambrosio, G.; Bossert, R.; Chlachidze, G.; DiMarco, J.; Zlobin, A.V.; Milanese, A.; Todesco, E.

2011-11-28T23:59:59.000Z

307

Magnetic damping for maglev  

DOE Green Energy (OSTI)

Magnetic damping is one of the important parameters to control the response and stability of maglev systems. An experimental study is presented to measure the magnetic damping using a direct method. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters on magnetic damping such as conductivity, gap, excitation frequency, and oscillation amplitude. The experimental technique is capable of measuring all magnetic damping coefficients, some of which can not be measured by an indirect method.

Chen, S.S.; Zhu, S.; Cai, Y.; Rote, D.M. [Argonne National Lab., IL (United States). Energy Technology Div.

1994-12-31T23:59:59.000Z

308

Magnetically attached sputter targets  

DOE Patents (OSTI)

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.

Makowiecki, D.M.; McKernan, M.A.

1994-02-15T23:59:59.000Z

309

Linear Collider Physics Resource Book Snowmass 2001  

Science Conference Proceedings (OSTI)

The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

Ronan (Editor), M.T.

2001-06-01T23:59:59.000Z

310

Linear Collider Collaboration Tech Notes LCC-0108  

NLE Websites -- All DOE Office Websites (Extended Search)

8 8 TESLA 2002-10 CBP Tech Note-268 November 2002 Comparison of Emittance Tuning Simulations in the NLC and TESLA Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Vertical emittance is a critical issue for future linear collider damping rings. Both NLC and TESLA specify vertical emittance of the order of a few picometers, below values currently achieved in any storage ring. Simulations show that algorithms based on correcting the closed orbit and the vertical dispersion can be effective in reducing the vertical emittance to the required levels, in the presence of a limited subset of

311

Maxwell's equations, linear gravity, and twistors  

SciTech Connect

A detailed outline is presented of several convergent points of view connecting the self-dual and anti-self-dual fields with their free data. This is doen for the Maxwell and for linearized gravity as exemplifying the approaches. The Sparling equation provides one tool of great power and characterizes one approach. The twistor theory of Penrose yields another equally powerful point of view. The links between these two basic approaches given in this paper provide a unification that allows workers and others with interest in this area to proceed more readily toward the goal of understanding the full nonlinear Einstein equations.

Kozameh, C.N.; Newman, E.T.; Porter, J.R.

1984-11-01T23:59:59.000Z

312

Experimental quantum private queries with linear optics  

Science Conference Proceedings (OSTI)

The quantum private query is a quantum cryptographic protocol to recover information from a database, preserving both user and data privacy: the user can test whether someone has retained information on which query was asked and the database provider can test the amount of information released. Here we discuss a variant of the quantum private query algorithm that admits a simple linear optical implementation: it employs the photon's momentum (or time slot) as address qubits and its polarization as bus qubit. A proof-of-principle experimental realization is implemented.

De Martini, Francesco [Dipartimento di Fisica, dell'Universita 'La Sapienza', Roma 00185 (Italy); Accademia Nazionale dei Lincei, via della Lungara 10, Roma 00165 (Italy); Giovannetti, Vittorio [NEST-CNR-INFM and Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Lloyd, Seth [MIT, RLE, and Department of Mechanical Engineering, MIT 3-160, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Maccone, Lorenzo [Institute for Scientific Interchange, 10133 Torino (Italy); QUIT, Dip. Fisica A. Volta, 27100 Pavia (Italy); Nagali, Eleonora; Sansoni, Linda; Sciarrino, Fabio [Dipartimento di Fisica, dell'Universita 'La Sapienza', Roma 00185 (Italy)

2009-07-15T23:59:59.000Z

313

Linear Collider Collaboration Tech Notes LCC-0099  

NLE Websites -- All DOE Office Websites (Extended Search)

099 099 August 2002 Space Charge Dynamics of Bright Electron Beams Alexander W. Chao, Rainer Pitthan, Toshiki Tajima, Dian Yeremian Stanford Linear Accelerator Center Stanford University Abstract: The longitudinal dynamics and its coupling with the transverse dynamics of bunched beams with strong space charge are analyzed. We introduce a self-consistent Vlasov description for the longitudinal phase space similar to the familiar description for the transverse phase space using a Kapchinskij-Vladimirskij (K-V) distribution [1]. A longitudinal beam envelope equation is derived. An exact solution is then obtained when coupling to the transverse dynamics is ignored. This longitudinal envelope equation is coupled to the transverse envelope

314

Solar receiver heliostat reflector having a linear drive and position information system  

DOE Patents (OSTI)

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.

Horton, Richard H. (Schenectady, NY)

1980-01-01T23:59:59.000Z

315

Second order particle motion equations and linear chromaticity calculation in accelerator rings  

SciTech Connect

The first part of this note presents a thorough study on the second order particle motion equations, both in continuous field and in hard edges, with emphasis put on the latter. Having quite general conditions and strict mathematical treatments, it provides a sound ground from which many problems can be solved without fear of being misled. Then the linear CHR calculation is inspected, the first step being a general analytical expression of the transverse oscillation phase increment due to a small disturbance. The expression for the CHR is then readily obtained since tune is the transverse oscillation number per turn and the CHR is the linear dependence of the tune on particle energy/momentum deviation. The last part gives the formulae for practical CHR calculation, which are general enough to include almost all the magnet types commonly used in various accelerator rings and are simpler than can be found elsewhere.

Liu, R.Z.

1984-01-01T23:59:59.000Z

316

Novel design and implementation of a permanent magnet linear tubular generator for ocean wave energy conversion.  

E-Print Network (OSTI)

??The worlds energy consumption is growing at an alarming rate and the need for renewable energy is apparent now more than ever. Estimates have shown (more)

[No author

2007-01-01T23:59:59.000Z

317

Simplest Potential Conservation Laws of Linear Evolution Equations  

E-Print Network (OSTI)

Every simplest potential conservation law of any (1+1)-dimensional linear evolution equation of even order proves induced by a local conservation law of the same equation. This claim is true also for linear simplest potential conservation laws of (1+1)-dimensional linear evolution equations of odd order, which are related to linear potential systems. We also derive an effective criterion for checking whether a quadratic conservation law of a simplest linear potential system is a purely potential conservation law of a (1+1)-dimensional linear evolution equation of odd order.

Boyko, Vyacheslav M

2010-01-01T23:59:59.000Z

318

Effect of trapping in a degenerate plasma in the presence of a quantizing magnetic field  

SciTech Connect

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.

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

319

Frequency scaling of linear super-colliders  

SciTech Connect

The development of electron-positron linear colliders in the TeV energy range will be facilitated by the development of high-power rf sources at frequencies above 2856 MHz. Present S-band technology, represented by the SLC, would require a length in excess of 50 km per linac to accelerate particles to energies above 1 TeV. By raising the rf driving frequency, the rf breakdown limit is increased, thereby allowing the length of the accelerators to be reduced. Currently available rf power sources set the realizable gradient limit in an rf linac at frequencies above S-band. This paper presents a model for the frequency scaling of linear colliders, with luminosity scaled in proportion to the square of the center-of-mass energy. Since wakefield effects are the dominant deleterious effect, a separate single-bunch simulation model is described which calculates the evolution of the beam bunch with specified wakefields, including the effects of using programmed phase positioning and Landau damping. The results presented here have been obtained for a SLAC structure, scaled in proportion to wavelength.

Mondelli, A.; Chernin, D.; Drobot, A.; Reiser, M.; Granatstein, V.

1986-06-01T23:59:59.000Z

320

High Field Magnet R&D |Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

High Field Magnet R&D High Field Magnet R&D The Superconducting Magnet Division is developing advanced magnet designs and magnet-related technologies for high field accelerator magnets. We are currently working on magnets for three inter-related programs: High Field Magnets for Muon Collider Papers, Presentations Common Coil Magnets Papers, Presentations Interaction Region Magnets Papers, Presentations High Temperature Superconductor (HTS) Magnets Papers, Presentations This is part of a multi-lab superconducting magnet development program for new accelerator facilities that would be part of the U.S. High Energy Physics program. These programs (@BNL, @FNAL, @LBNL) are quite complimentary to each other, so that magnet designs and technologies developed at one laboratory can be easily transferred to another. The BNL

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321

Broadening and shifting of the methanol 119 {mu}m gain line of linear and circular polarization by collision with chiral molecules  

Science Conference Proceedings (OSTI)

Evidence of circular dichroism has been observed in the spectral properties of a gas of left-right symmetric molecules. This dichroism comes about as the result of collisions of the symmetric molecules with left-right asymmetric molecules introduced as a buffer gas. In this sense, the dichroism can be said to have been transferred from the chiral buffer molecules to the symmetric, non-chiral molecules of the background vapor. This transferred dichroism appears as broadening in the gain line of the symmetric molecule which is asymmetric with respect to the right or left handedness of a circularly polarized probe. The broadening of the 119 {mu}m line of the methanol molecule was observed using infrared-far infrared double resonance spectroscopy.

J.S. Bakos; G. Djotyan; Zsuzsa Soerlei; J. Szigeti; D. K. Mansfield; J. Sarkozi

2000-06-21T23:59:59.000Z

322

Point and Interval Forecasting of Spot Electricity Prices: Linear vs. Non-Linear Time Series Models  

E-Print Network (OSTI)

In this paper we assess the short-term forecasting power of different time series models in the electricity spot market. In particular we calibrate AR/ARX (X stands for exogenous/fundamental variable system load in our study), AR/ARX-GARCH, TAR/TARX and Markov regime-switching models to California Power Exchange (CalPX) system spot prices. We then use them for out-ofsample point and interval forecasting in normal and extremely volatile periods preceding the market crash in winter 2000/2001. We find evidence that (i) non-linear, threshold regime-switching (TAR/TARX) models outperform their linear counterparts, both in point and interval forecasting, and that (ii) an additional GARCH component generally decreases point forecasting efficiency. Interestingly, the former result challenges a number of previously published studies on the failure of non-linear regime-switching models in forecasting.

Adam Misiorek; Stefan Trueck; Rafal Weron

2006-01-01T23:59:59.000Z

323

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Cool Magnetic Molecules Cool Magnetic Molecules Print Wednesday, 25 May 2011 00:00 Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

324

Current-driven instability of magnetic jets  

E-Print Network (OSTI)

MHD instabilities can be responsible for the complex morphology of astrophysical jets. We consider the stability properties of jets containing both the azimuthal and axial field of subthermal strength. The presence of the magnetic field with complex topology in jets is suggested by theoretical models and it is consistent with recent observations. Stability is discussed by means of a linear analysis of the ideal MHD equations.We argue that, in the presence of azimuthal and axial magnetic fields, the jet is always unstable to non-axisymmetric perturbations. Stabilization does not occur even if the strengths of these field components are comparable. If the axial field is weaker than the azimuthal one, instability occurs for perturbations with any azimuthal wave number $m$, and the growth rate reach a saturation value for small values of $m$. If the axial field is stronger than the toroidal one, the instability shows off for perturbations with relatively large $m$.

Bonanno, Alfio

2010-01-01T23:59:59.000Z

325

Pulse magnetic welder  

DOE Patents (OSTI)

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.

Christiansen, D.W.; Brown, W.F.

1984-01-01T23:59:59.000Z

326

Magnetic latching solenoid  

DOE Patents (OSTI)

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.

Marts, Donna J. (Idaho Falls, ID); Richardson, John G. (Idaho Falls, ID); Albano, Richard K. (Idaho Falls, ID); Morrison, Jr., John L. (Idaho Falls, ID)

1995-01-01T23:59:59.000Z

327

MAGNETIC TOPOLOGY OF BUBBLES IN QUIESCENT PROMINENCES  

Science Conference Proceedings (OSTI)

We study a polar-crown prominence with a bubble and its plume observed in several coronal filters by the SDO/AIA and in H{alpha} by the MSDP spectrograph in Bialkow (Poland) to address the following questions: what is the brightness of prominence bubbles in EUV with respect to the corona outside of the prominence and the prominence coronal cavity? What is the geometry and topology of the magnetic field in the bubble? What is the nature of the vertical threads seen within prominences? We find that the brightness of the bubble and plume is lower than the brightness of the corona outside of the prominence, and is similar to that of the coronal cavity. We constructed linear force-free models of prominences with bubbles, where the flux rope is perturbed by inclusion of parasitic bipoles. The arcade field lines of the bipole create the bubble, which is thus devoid of magnetic dips. Shearing the bipole or adding a second one can lead to cusp-shaped prominences with bubbles similar to the observed ones. The bubbles have complex magnetic topology, with a pair of coronal magnetic null points linked by a separator outlining the boundary between the bubble and the prominence body. We conjecture that plume formation involves magnetic reconnection at the separator. Depending on the viewing angle, the prominence can appear either anvil-shaped with predominantly horizontal structures, or cusp-shaped with predominantly vertical structuring. The latter is an artifact of the alignment of magnetic dips with respect to the prominence axis and the line of sight.

Dudik, J. [DAPEM, Faculty of Mathematics Physics and Computer Science, Comenius University, Mlynska Dolina F2, 84248 Bratislava (Slovakia); Aulanier, G.; Schmieder, B. [Observatoire de Paris, LESIA, UMR 8109 (CNRS), F-92195 Meudon Principal Cedex (France); Zapior, M. [Astronomical Institute, University of Wroclaw, Kopernika 11, 51622 Wroclaw (Poland); Heinzel, P., E-mail: dudik@fmph.uniba.sk [Astronomical Institute of the Academy of Sciences of the Czech Republic, Fricova 298, 25165 Ondrejov (Czech Republic)

2012-12-10T23:59:59.000Z

328

Magnetically leviated superconducting bearing  

DOE Patents (OSTI)

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.

Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)

1993-01-01T23:59:59.000Z

329

Nanostructrured Magnetic Materials  

Science Conference Proceedings (OSTI)

Aug 8, 2013 ... The demand for OFF-ON becomes increasingly important as ... The residual magnetic flux density and maximum energy product of the...

330

Rare Earth Magnets  

Science Conference Proceedings (OSTI)

Mar 6, 2013 ... Performance and Endurance of Nd-Fe-B Sintered Magnets in E-Motor Application Conditions: Martina Moore1; Ralph Sueptitz1; Margitta...

331

Rare Earth Magnets  

Science Conference Proceedings (OSTI)

Aug 8, 2013 ... Current high performance permanent magnets (PM) for traction motors of (hybrid) electric vehicles use substantial amount of Dy in Nd-Fe-B...

332

Magnetic Materials and Properties  

Science Conference Proceedings (OSTI)

Aug 5, 2013 ... Following vacuum distillation of the Mg-RE alloy, 98% pure RE metals can be recovered, which are then used to synthesize permanent magnet...

333

Neutrino Propagation in a Strongly Magnetized Medium  

E-Print Network (OSTI)

We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit ($M_{W}\\gg \\sqrt{B}\\gg m_{e},T,\\mu ,| \\mathbf{p}| $) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong $B\\gg T^{2}$ and weakly-strong $B \\gtrsim T^{2}$ fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a term of interaction between the magnetic field and an induced neutrino magnetic moment, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For strong and weakly-strong fields, it is found that the field-dependent correction to the neutrino energy in a neutral medium is much larger than the thermal one. Possible applications to cosmology and astrophysics are considered.

E. Elizalde; E. J. Ferrer; V. de la Incera

2004-04-26T23:59:59.000Z

334

Neutrino Propagation in a Strongly Magnetized Medium  

E-Print Network (OSTI)

We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit ($M_{W}\\gg \\sqrt{B}\\gg m_{e},T,\\mu ,| \\mathbf{p}| $) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong $B\\gg T^{2}$ and weakly-strong $B \\gtrsim T^{2}$ fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a magnetic-field neutrino-induced-magnetic-moment interaction term, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For str...

Elizalde, E; De la Incera, V

2004-01-01T23:59:59.000Z

335

Molten metal feed system controlled with a traveling magnetic field  

DOE Patents (OSTI)

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.

Praeg, Walter F. (Palos Park, IL)

1991-01-01T23:59:59.000Z

336

Molten metal feed system controlled with a traveling magnetic field  

DOE Patents (OSTI)

An apparatus for controlling the feed of molten metal in a continuous metal casting system comprising 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} {minus} 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 characteristic of the metal being cast. 8 figs.

Praeg, W.F.

1989-03-06T23:59:59.000Z

337

ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE  

SciTech Connect

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.

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

338

Magnetism Highlights| Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetism Magnetism SHARE Magnetism Highlights 1-5 of 5 Results ARCS maps collaborative magnetic spin behavior in iron telluride December 01, 2011 - Researchers have long thought that magnetism and superconductivity are mutually exclusive. The former typically involves localized atomic electrons. The latter requires freely propagating, itinerant electrons. Unexpected Magnetic Excitations in Doped Insulator Surprise Researchers October 01, 2011 - When doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. Neutron Analysis Reveals Unique Atomic-Scale Behavior of "Cobalt Blue" September 01, 2011 - Neutron scattering studies of "cobalt blue," a

339

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers  

NLE Websites -- All DOE Office Websites (Extended Search)

Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Linear Electric Field Time-Of-Flight Ion Mass Spectrometers Time-of-flight mass spectrometer comprising a first drift...

340

Classification of linearly compact simple Jordan and generalized Poisson superalgebras  

E-Print Network (OSTI)

We classify all linearly compact simple Jordan superalgebras over an algebraically closed field of characteristic zero. As a corollary, we deduce the classification of all linearly compact unital simple generalized Poisson superalgebras.

Nicoletta Cantarini; Victor G. Kac; To Ernest; Borisovich Vinberg

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Solid-State Lighting: LED Replacements for Linear Fluorescent...  

NLE Websites -- All DOE Office Websites (Extended Search)

LED Replacements for Linear Fluorescent Lamps Webcast to someone by E-mail Share Solid-State Lighting: LED Replacements for Linear Fluorescent Lamps Webcast on Facebook Tweet about...

342

Quantum-mechanical linear filtering of random signal sequences  

Science Conference Proceedings (OSTI)

The problem of estimating a member of a scalar random signal sequence with quantum-mechanical measurements is considered. The minimum variance linear estimator based on an optimal present quantum measurement and optimal linear processing of past measurements ...

J. Baras; R. Harger; Young Park

1976-01-01T23:59:59.000Z

343

AN EFFICIENT ALGORITHM FOR SECOND-ORDER CONE LINEAR ...  

E-Print Network (OSTI)

linear transformation M ? Rnn in the second-order cone linear comple- ..... does not require extra storage except for the vector y(k) and several scalars. This.

344

Linear Baroclinic instability with the Geostrophic Momentum Approximation  

Science Conference Proceedings (OSTI)

The linear Eady model of baroclinic instability with the geostrophic momentum (GM) approximation is solved analytically in physical space and shown to be identical to linear three-dimensional semigeostrophic theory. Both the growth rates and the ...

Peter R. Bannon

1989-02-01T23:59:59.000Z

345

Math 21a Linear Algebra Information for students, Fall 2002  

E-Print Network (OSTI)

/intro.html Grader: TBA Text: LINEAR ALGEBRA, 3rd edition, by J. Fraleigh and R. Beauregard, Addison Wesley Longman

Kleinbock, Dmitry

346

Linear Collider Collaboration Tech Notes LCC-0063  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 May 2001 Varying alpha/lambda in NLC Structures - BNS Damping and Emittance Growth G. Stupakov and Z. Li Stanford Linear Accelerator Center Stanford, CA Abstract: In this note we consider the effect of varying this iris opening in the NLC structures on the beam dynamics and the rf efficiency in the linac. Varying a/λ in NLC structures - BNS damping and emittance growth G. Stupakov and Z. Li SLAC, Stanford University, Stanford, CA 94309 In this note we consider the effect of the varying the iris opening a in the NLC structures on the beam dynamics and the RF efficiency in the linac. The most important consequence of the variation of the iris openings is the change of the longitudinal and transverse wakefields. Wake as a function of parameter a for the NLC structures has been previously calculated by K. Bane. Here we will use his

347

Linear Collider Collaboration Tech Notes LCC-70  

NLE Websites -- All DOE Office Websites (Extended Search)

70 70 August 2001 Design Studies of Positron Collection for the NLC Yuri K. Batygin, Ninod K. Bharadwaj, David C. Schultz ,John C. Sheppard Stanford Linear Accelerator Center Stanford, CA Abstract: The positron source for the NLC project utilizes a 6.2 GeV electron beam interacting in a high-Z positron production target. The electromagnetic shower in the target results in large energy deposition which can cause damage to the target. Optimization of the collection system is required to insure long-term operation of the target with needed high positron yield into the 6-dimensional acceptance of the subsequent pre-damping ring. Positron tracking through the accelerating system indicates a dilution of the initial positron phase space density. Results of simulations indicate that a

348

Linear Collider Collaboration Tech Notes LCC-0101  

NLE Websites -- All DOE Office Websites (Extended Search)

1 1 August 2002 Collimator Wakefield Calculations for ILC-TRC Report Peter Tenenbaum Stanford Linear Accelerator Center Stanford University Stanford, CA 94309, USA Abstract: We summarize the formalism of collimator wakefields and their effect on beams that are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems. Collimator Wakefield Calculations for ILC-TRC Report P. Tenenbaum LCC-Note-0101 20-Aug-2002 Abstract We summarize the formalism of collimator wakefields and their effect on beams which are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems. 1 Introduction One of the beam dynamics effects which must be evaluated for the

349

Symmetry Breaking in Linearly Coupled Dynamical Lattices  

E-Print Network (OSTI)

We examine one- and two-dimensional (1D and 2D) models of linearly coupled lattices of the discrete-nonlinear-Schr{\\"{o}}dinger type. Analyzing ground states of the systems with equal powers in the two components, we find a symmetry-breaking phenomenon beyond a critical value of the squared $l^2$-norm. Asymmetric states, with unequal powers in their components, emerge through a subcritical pitchfork bifurcation, which, for very weakly coupled lattices, changes into a supercritical one. We identify the stability of various solution branches. Dynamical manifestations of the symmetry breaking are studied by simulating the evolution of the unstable branches. The results present the first example of spontaneous symmetry breaking in 2D lattice solitons. This feature has no counterpart in the continuum limit, because of the collapse instability in the latter case.

Herring, G; Malomed, B A; Carretero-Gonzlez, R; Frantzeskakis, D J

2007-01-01T23:59:59.000Z

350

BEPC-II Magnet Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

BEPC-II Magnet Project BEPC-II Magnet Project Project Overview The BEPC-II magnets are Interaction Region magnets to be used as part of an upgrade to the Beijing Electron Positron Collider. Two magnets will be produced, both of which will be inserted within the solenoidal detector at one of the collision points. Since the best use of the quadrupole focusing in this case requires placing the magnet as close to the collision point as possible, these magnets will be used within the magnetic field of the detector. This constrains the materials that can be used for construction to only non-magnetic materials. It also places severe demands on the structure of the magnet and it's holding supports due to the reaction forces between the solenoid and the magnet. To create the coil pattern for the final magnet, the coils will be

351

International linear collider reference design report  

Science Conference Proceedings (OSTI)

The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

Aarons, G.

2007-06-22T23:59:59.000Z

352

Technical Section: Linear approximation of Bidirectional Reflectance Distribution Functions  

Science Conference Proceedings (OSTI)

Various empirical and theoretical models of the surface reflectance have been introduced so far. Most of these models are based on functions with non-linear parameters and therefore faces some computational difficulties involved in non-linear optimization ... Keywords: BRDF representation, Linear models, Principal components, Reflection models, Rendering

Aydin Ozturk; Murat Kurt; Ahmet Bilgili; Cengiz Gungor

2008-04-01T23:59:59.000Z

353

Solving Systems of Linear Equations with Relaxed Monte Carlo Method  

Science Conference Proceedings (OSTI)

The problem of solving systems of linear algebraic equations by parallel Monte Carlo numerical methods is considered. A parallel Monte Carlo method with relaxation is presented. This is a report of a research in progress, showing the effectiveness of ... Keywords: Monte Carlo method, linear solver, parallel algorithms, systems of linear algebraic equations

Chih Jeng Kenneth Tan

2002-05-01T23:59:59.000Z

354

Wiggler plane focusing in a linear free electron laser  

DOE Patents (OSTI)

Free electron laser apparatus that provides a magnetic centering force to turn or focus a non-axial electron toward the longitudinal axis as desired. The focusing effect is provided by wiggler magnet pole faces that are approximately parabolically shaped.

Scharlemann, Ernst T. (Livermore, CA)

1988-01-01T23:59:59.000Z

355

Passive magnetic bearing configurations  

Science Conference Proceedings (OSTI)

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.

Post, Richard F. (Walnut Creek, CA)

2011-01-25T23:59:59.000Z

356

EXOTIC MAGNETS FOR ACCELERATORS.  

SciTech Connect

Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

WANDERER, P.

2005-09-18T23:59:59.000Z

357

Modeling of the charging characteristic of linear-type superconducting power supply using granular-based radial basis function neural networks  

Science Conference Proceedings (OSTI)

Since superconducting coils cause the current decay due to connection resistance and intrinsic characteristic in the persistent current mode, various current compensations should be required to maintain stable property in the superconducting magnet system. ... Keywords: Charging characteristic, Fuzzy C-means (FCM) clustering method, Granular-based radial basis function neural network, Information granules, K-means clustering, Linear-type superconducting power supply

H. -S. Park; W. Pedrycz; Y. -D. Chung; S. -K. Oh

2012-01-01T23:59:59.000Z

358

Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

3 - 6/13/06 3 - 6/13/06 Superconducting Magnet Division S&T Committee Program Review June 22-23, 2006 Conference Room A, Bldg. 725, BNL DRAFT AGENDA Thursday, June 22 0830 Executive Session to address the charge S. Aronson (25 min) 0855 Welcome S. Aronson (5 min) 0900 Superconducting Magnet Division Status & M. Harrison (45 + 15 min) Issues - mission statement, core competencies, themes, program, problems, etc. 1000 Themes - Nb3Sn, HTS, Direct wind, Accelerator integration, P. Wanderer (20 + 10 min) rapid cycling Core Competencies 1030 Superconducting Materials A. Ghosh (20 + 5 min) 1055 Break 1110 Magnetic Design R. Gupta (20 + 5 min) 1135 Magnet Construction M. Anerella (20 + 5 min) 1200 Magnet Testing G. Ganetis (20 + 5 min)

359

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

360

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

362

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

363

Magnet pole tips  

DOE Patents (OSTI)

An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

Thorn, Craig E. (Wading River, NY); Chasman, Chellis (Setauket, NY); Baltz, Anthony J. (Coram, NY)

1984-04-24T23:59:59.000Z

364

Magnet pole tips  

DOE Patents (OSTI)

An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

Thorn, C.E.; Chasman, C.; Baltz, A.J.

1981-11-19T23:59:59.000Z

365

Cool Magnetic Molecules  

NLE Websites -- All DOE Office Websites (Extended Search)

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

366

Magnetization of neutron star matter  

E-Print Network (OSTI)

The magnetization of neutron star matter in magnetic fields is studied by employing the FSUGold interaction. It is found that the magnetic susceptibilities of the charged particles (proton, electron and muon) can be larger than that of neutron. The effects of the anomalous magnetic moments (AMM) of each component on the magnetic susceptibility are examined in detail. It is found that the proton and electron AMM affect their respective magnetic susceptibility evidently in strong magnetic fields. In addition, they are the protons instead of the electrons that contribute most significantly to the magnetization of the neutron star matter in a relative weak magnetic field, and the induced magnetic field due to the magnetization can be appear to be very large. Finally, the effect of the density-dependent symmetry energy on the magnetization is discussed.

Dong, Jianmin; Gu, Jianzhong

2013-01-01T23:59:59.000Z

367

The Solar Coronal Magnetic Field Measurements With SOLARC  

E-Print Network (OSTI)

Direct solar coronal magnetic field measurements have become possible since recent development of high-sensitivity infrared detection technology. The SOLARC instrument installed on Mt. Haleakala is such a polarimetric coronagraph that was designed for routinely observing Stokes parameter profiles in near infrared (NIR) wavelengthes. The Fe$^{+12}$ 1075 nm forbidden coronal emission line (CEL) is potential for weak coronal magnetic field detection. As a first step the potential field model has been used to compare with the SOLARC observation in the Fe$^{+12}$ 1075 nm line (Liu and Lin 2008). It's found that the potential fields can be a zeroth-order proxy for approaching the observed coronal field above a simple stable sunspot. In this paper we further discuss several nodi that are hampering the progress for reconstructing the real coronal magnetic field structures. They include the well-known Van Vleck effect in linear polarization signals, ignorance of the information of the NIR emission sources (i.e., inversion problem of coronal magnetic fields), a fat lot of global non-linear force-free field tools available for better modeling coronal magnetic fields, and so on.

Y. Liu; H. Lin

2008-09-04T23:59:59.000Z

368

Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State  

E-Print Network (OSTI)

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 ...

Rgnier, S

2008-01-01T23:59:59.000Z

369

Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State  

E-Print Network (OSTI)

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.

S. Regnier; E. R. Priest

2008-05-12T23:59:59.000Z

370

Magnetic moments of T=3/2 mirror pairs  

Science Conference Proceedings (OSTI)

We predict values of the magnetic moments of T=3/2 proton-rich fp-shell nuclei in the mass range A=43-53, by using known values for their neutron-rich mirrors together with shell-model estimates for small quantities. We extend the analysis to those T=3/2 sd-shell mirror pairs for which both the T{sub z}=-3/2 and T{sub z}=+3/2 magnetic moments have been measured. We find that these obey the same linear relation as previously deduced for T=1/2 mirror pairs.

Perez, S. M. [Department of Physics, University of Cape Town, Private Bag, Rondebosch 7700 (South Africa); iThemba LABS, P. O. Box 722, Somerset West 7129 (South Africa); Richter, W. A. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Brown, B. A. [Department of Physics and Astronomy, and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Horoi, M. [Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859 (United States)

2010-12-15T23:59:59.000Z

371

Governance of the International Linear Collider Project  

SciTech Connect

Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency, clearly apportioned at both a national and global level, is essential if the project is to be realised. Finally, models for running costs and decommissioning at the conclusion of the ILC project are proposed. This document represents an interim report of the bodies and individuals studying these questions inside the structure set up and supervised by the International Committee for Future Accelerators (ICFA). It represents a request for comment to the international community in all relevant disciplines, scientific, technical and most importantly, political. Many areas require further study and some, in particular the site selection process, have not yet progressed sufficiently to be addressed in detail in this document. Discussion raised by this document will be vital in framing the final proposals due to be published in 2012 in the Technical Design Report being prepared by the Global Design Effort of the ILC.

Foster, B.; /Oxford U.; Barish, B.; /Caltech; Delahaye, J.P.; /CERN; Dosselli, U.; /INFN, Padua; Elsen, E.; /DESY; Harrison, M.; /Brookhaven; Mnich, J.; /DESY; Paterson, J.M.; /SLAC; Richard, F.; /Orsay, LAL; Stapnes, S.; /CERN; Suzuki, A.; /KEK, Tsukuba; Wormser, G.; /Orsay, LAL; Yamada, S.; /KEK, Tsukuba

2012-05-31T23:59:59.000Z

372

Magnetic Thin Films and Devices  

Science Conference Proceedings (OSTI)

... metal atoms that form small magnets with Curie ... a toggle operation of the magnetic state of ... A high-frequency probe driving a microwave waveguide ...

2010-10-05T23:59:59.000Z

373

Permanent Magnets for Energy Applications  

Science Conference Proceedings (OSTI)

Mar 13, 2012 ... Magnetic Materials for Energy Applications II: Permanent Magnets for ... to 500% in the last 12 months, the most unstable being the price of Dy.

374

Experiment Hazard Class 9 - Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

hazard classification applies to all experiments involving magnets, magnetic fields, and electric fields. Other hazard classifications such as electrical safety and their...

375

Nanostructured Materials for Magnetic Refrigeration  

Science Conference Proceedings (OSTI)

... of Nd-Fe-B Magnets to the Megawatt Scale Generator for the Wind Turbine ... Low Loss, High Power Density Magnetics in Inductor/Transformer Cores for Army ...

376

Search Publications | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Rapid Cycling Magnets Helical Magnets HERA upgrade LHC IR Dipoles RHIC Publications Search Publications Selected Cryogenic Data Notebook Proceedings of the 1968 Summer Study on...

377

Prediction of Magnetic Storms by Nonlinear Models  

E-Print Network (OSTI)

The strong correlation between magnetic storms and southward interplanetary magnetic field (IMF) is well known from linear prediction filter studies using the Dst and IMF data. However, the linear filters change significantly from one storm to another and thus are limited in their predicting ability. Previous studies have indicated nonlinearity in the magnetospheric response as the ring current decay rate varies with the Dst value during storms. We present in this letter nonlinear models for the evolution of the Dst based on the OMNI database for 1964-1990. When solar wind data are available in advance, the evolution of storms can be predicted from the Dst and IMF data. Solar wind data, however, are not available most of the time or are available typically an hour or less in advance. Therefore, we have developed nonlinear predictive models based on the Dst data alone. In the absence of solar wind data, these models cannot predict the storm onset, but can predict the storm evolution, an...

J. A. Valdivia; A. S. Sharma; K. Papadopoulos

1996-01-01T23:59:59.000Z

378

Precision envelope detector and linear rectifier circuitry  

DOE Patents (OSTI)

Disclosed is a method and apparatus for the precise linear rectification and envelope detection of oscillatory signals. The signal is applied to a voltage-to-current converter which supplies current to a constant current sink. The connection between the converter and the sink is also applied through a diode and an output load resistor to a ground connection. The connection is also connected to ground through a second diode of opposite polarity from the diode in series with the load resistor. Very small amplitude voltage signals applied to the converter will cause a small change in the output current of the converter, and the difference between the output current and the constant current sink will be applied either directly to ground through the single diode, or across the output load resistor, dependent upon the polarity. Disclosed also is a full-wave rectifier utilizing constant current sinks and voltage-to-current converters. Additionally, disclosed is a combination of the voltage-to-current converters with differential integrated circuit preamplifiers to boost the initial signal amplitude, and with low pass filtering applied so as to obtain a video or signal envelope output.

Davis, Thomas J. (Richland, WA)

1980-01-01T23:59:59.000Z

379

Linearized Functional Minimization for Inverse Modeling  

SciTech Connect

Heterogeneous aquifers typically consist of multiple lithofacies, whose spatial arrangement significantly affects flow and transport. The estimation of these lithofacies is complicated by the scarcity of data and by the lack of a clear correlation between identifiable geologic indicators and attributes. We introduce a new inverse-modeling approach to estimate both the spatial extent of hydrofacies and their properties from sparse measurements of hydraulic conductivity and hydraulic head. Our approach is to minimize a functional defined on the vectors of values of hydraulic conductivity and hydraulic head fields defined on regular grids at a user-determined resolution. This functional is constructed to (i) enforce the relationship between conductivity and heads provided by the groundwater flow equation, (ii) penalize deviations of the reconstructed fields from measurements where they are available, and (iii) penalize reconstructed fields that are not piece-wise smooth. We develop an iterative solver for this functional that exploits a local linearization of the mapping from conductivity to head. This approach provides a computationally efficient algorithm that rapidly converges to a solution. A series of numerical experiments demonstrates the robustness of our approach.

Wohlberg, Brendt [Los Alamos National Laboratory; Tartakovsky, Daniel M. [University of California, San Diego; Dentz, Marco [Institute of Environmental Assessment and Water Research, Barcelona, Spain

2012-06-21T23:59:59.000Z

380

Linear air-fuel sensor development  

DOE Green Energy (OSTI)

The electrochemical zirconia solid electrolyte oxygen sensor, is extensively used for monitoring oxygen concentrations in various fields. They are currently utilized in automobiles to monitor the exhaust gas composition and control the air-to-fuel ratio, thus reducing harmful emission components and improving fuel economy. Zirconia oxygen sensors, are divided into two classes of devices: (1) potentiometric or logarithmic air/fuel sensors; and (2) amperometric or linear air/fuel sensors. The potentiometric sensors are ideally suited to monitor the air-to-fuel ratio close to the complete combustion stoichiometry; a value of about 14.8 to 1 parts by volume. This occurs because the oxygen concentration changes by many orders of magnitude as the air/fuel ratio is varied through the stoichiometric value. However, the potentiometric sensor is not very sensitive to changes in oxygen partial pressure away from the stoichiometric point due to the logarithmic dependence of the output voltage signal on the oxygen partial pressure. It is often advantageous to operate gasoline power piston engines with excess combustion air; this improves fuel economy and reduces hydrocarbon emissions. To maintain stable combustion away from stoichiometry, and enable engines to operate in the excess oxygen (lean burn) region several limiting-current amperometric sensors have been reported. These sensors are based on the electrochemical oxygen ion pumping of a zirconia electrolyte. They typically show reproducible limiting current plateaus with an applied voltage caused by the gas diffusion overpotential at the cathode.

Garzon, F. [Los Alamos National Lab., NM (United States); Miller, C. [General Motors, Flint, MI (United States). GM/Delphi E. Division

1996-12-14T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Liquid cooled, linear focus solar cell receiver  

DOE Patents (OSTI)

Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

Kirpich, A.S.

1983-12-08T23:59:59.000Z

382

Liquid cooled, linear focus solar cell receiver  

DOE Patents (OSTI)

Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

Kirpich, Aaron S. (Broomall, PA)

1985-01-01T23:59:59.000Z

383

Magnetically Driven Accretion  

E-Print Network (OSTI)

We carried out 2.5-dimensional resistive magnetohydrodynamic simulations to study the effects of magnetic diffusivity on magnetically driven mass accretion and jet formation. The initial state is a constant angular-momentum torus threaded by large-scale vertical magnetic fields. Since the angular momentum of the torus is extracted due to magnetic braking, the torus medium falls toward the central region. The infalling matter twists the large-scale magnetic fields and drives bipolar jets. We found that (1) when the normalized magnetic diffusivity, ? ? ?/(r0VK0), where VK0 is the Keplerian rotation speed at a reference radius r = r0, is small (? ? 10 ?3), mass accretion and jet formation take place intermittently; (2) when 10 ?3 ? ? ? 10 ?2, the system evolves toward a quasi-steady state; and (3) when ? ? 10 ?2 the accretion/mass 1 outflow rate decreases with ? and approaches 0. The results of these simulations indicate that in the center of a galaxy which has a super-massive ( ? 10 9 M?) black hole, a massive ( ? 10 8 M?) gas torus and magnetic braking provide a mass accretion rate which is sufficient to explain the activity of AGNs when ? ? 5 10?2.

Takuhito Kuwabara; Kazunari Shibata; Takahiro Kudoh

2000-01-01T23:59:59.000Z

384

High power linear pulsed beam annealer  

DOE Patents (OSTI)

A high power pulsed electron beam is produced in a system comprised of an electron gun having a heated cathode, control grid, focus ring, and a curved drift tube. The drift tube is maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring and to thereby eliminate space charge. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube and imparts motion on electrons in a spiral path for shallow penetration of the electrons into a target. The curvature of the tube is selected so there is no line of sight between the cathode and a target holder positioned within a second drift tube spaced coaxially from the curved tube. The second tube and the target holder are maintained at a reference voltage that decelerates the electrons. A second coil surrounding the second drift tube maintains the electron beam focused about the axis of the second drift tube and compresses the electron beam to the area of the target. The target holder can be adjusted to position the target where the cross section of the beam matches the area of the target.

Strathman, Michael D. (Concord, CA); Sadana, Devendra K. (Berkeley, CA); True, Richard B. (Sunnyvale, CA)

1983-01-01T23:59:59.000Z

385

Magnetic field generator  

DOE Patents (OSTI)

A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

Krienin, Frank (Shoreham, NY)

1990-01-01T23:59:59.000Z

386

Moment free toroidal magnet  

DOE Patents (OSTI)

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.

Bonanos, Peter (East Brunswick, NJ)

1983-01-01T23:59:59.000Z

387

Permanent magnet energy conversion machine with magnet mounting arrangement  

DOE Patents (OSTI)

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.

Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN)

1999-01-01T23:59:59.000Z

388

Ion-acoustic cnoidal wave and associated non-linear ion flux in dusty plasma  

Science Conference Proceedings (OSTI)

Using reductive perturbation method with appropriate boundary conditions, coupled evolution equations for first and second order potentials are derived for ion-acoustic waves in a collisionless, un-magnetized plasma consisting of hot isothermal electrons, cold ions, and massive mobile charged dust grains. The boundary conditions give rise to renormalization term, which enable us to eliminate secular contribution in higher order terms. Determining the non secular solution of these coupled equations, expressions for wave phase velocity and averaged non-linear ion flux associated with ion-acoustic cnoidal wave are obtained. Variation of the wave phase velocity and averaged non-linear ion flux as a function of modulus (k{sup 2}) dependent wave amplitude are numerically examined for different values of dust concentration, charge on dust grains, and mass ratio of dust grains with plasma ions. It is found that for a given amplitude, the presence of positively (negatively) charged dust grains in plasma decreases (increases) the wave phase velocity. This behavior is more pronounced with increase in dust concentrations or increase in charge on dust grains or decrease in mass ratio of dust grains. The averaged non-linear ion flux associated with wave is positive (negative) for negatively (positively) charged dust grains in the plasma and increases (decreases) with modulus (k{sup 2}) dependent wave amplitude. For given amplitude, it increases (decreases) as dust concentration or charge of negatively (positively) charged dust grains increases in the plasma.

Jain, S. L. [Poornima Group of Institution, Sitapura, Jaipur 302022 (India); Tiwari, R. S. [Regional College for Education, Research and Technology, Jaipur 302022 (India); Mishra, M. K. [Department of Physics, University of Rajasthan, Jaipur 302004 (India)

2012-10-15T23:59:59.000Z

389

A Novel MagPipe Pipeline transportation system using linear motor drives  

Science Conference Proceedings (OSTI)

A novel capsule pipeline transportation system using linear motor drives, called Magplane MagPipe, is under development with the intention to replace trucks and railways for hauling materials from the mine to the rail head, power plant, or processing plant with reduced operating cost and energy consumption. The initial demonstration of a MagPipe line in Inner Mongolia will be a 500-m-long double-pipe coal transport system with the design transportation capacity of 3 Mega-Mg per year. The pipeline consists of 6-m-long plastic pipe modules with an I-beam suspension system inside the pipe to carry sets of five coupled capsules. The pipe will also contain noncontinuous motor winding modules spaced at 50-m intervals. A set of Halbach-arrayed permanent magnets on the bottom of the capsules interact with the linear motor windings to provide propulsion. The motor is driven by variable frequency drives outside the pipe to control the speed. This paper briefly describes the overall MagPipe pipeline transportation system, including the preliminary conclusions of the linear synchronous motor analysis.

Fang, J.R.; Montgomery, D.B.; Roderick, L. [Magplane Technology Inc., Littleton, MA (United States)

2009-11-15T23:59:59.000Z

390

Radio frequency pulse compression experiments at SLAC (Stanford Linear Accelerator Center)  

Science Conference Proceedings (OSTI)

Proposed future positron-electron linear colliders would be capable of investigating fundamental processes of interest in the 0.5--5 TeV beam-energy range. At the SLAC Linear Collider (SLC) gradient of about 20 MV/m this would imply prohibitive lengths of about 50--250 kilometers per linac. We can reduce the length by increasing the gradient but this implies high peak power, on the order of 400-- to 1000-MW at X-Band. One possible way to generate high peak power is to generate a relatively long pulse at a relatively low power and compress it into a short pulse with higher peak power. It is possible to compress before DC to RF conversion, as is done using magnetic switching for induction linacs, or after DC to RF conversion, as is done for the SLC. Using RF pulse compression it is possible to boost the 50-- to 100-MW output that has already been obtained from high-power X-Band klystrons the levels required by the linear colliders. In this note only radio frequency pulse compression (RFPC) is considered.

Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Miller, R.H.; Nantista, C.; Spalek, G.; Wilson, P.B.

1991-01-01T23:59:59.000Z

391

High-gradient compact linear accelerator  

DOE Patents (OSTI)

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

Carder, B.M.

1995-12-31T23:59:59.000Z

392

Stability Issues in Ambient-Temperature Passive Magnetic Bearing Systems  

DOE Green Energy (OSTI)

The ambient-temperature passive magnetic bearing system developed at the Lawrence Livermore National Laboratory achieves rotor-dynamic stability by employing special combinations of levitating and stabilizing elements. These elements, energized by permanent magnet material, create the magnetic and electrodynamic forces that are required for the stable levitation of rotating systems, such as energy-storage flywheels. Stability criteria, derived from theory, describe the bearing element parameters, i.e., stiffnesses and damping coefficients, that are required both to assure stable levitation (''Earnshaw-stability''), and stability against whirl-type rotor-dynamic instabilities. The work described in this report concerns experimental measurements and computer simulations that address some critical aspects of this overall stability problem. Experimentally, a test device was built to measure the damping coefficient of dampers that employ eddy currents induced in a metallic disc. Another test device was constructed for the purpose of measuring the displacement-dependent drag coefficient of annular permanent magnet bearing elements. In the theoretical developments a computer code was written for the purpose of simulating the rotor-dynamics of our passive bearing systems. This code is capable of investigating rotor-dynamic stability effects for both small-amplitude transient displacements (i.e., those within the linear regime), and for large-amplitude displacements, where non-linear effects can become dominant. Under the latter conditions a bearing system that is stable for small-amplitude displacements may undergo a rapidly growing rotor-dynamic instability once a critical displacement is exceeded. A new result of the study was to demonstrate that stiffness anisotropy of the bearing elements (which can be designed into our bearing system) is strongly stabilizing, not only in the linear regime, but also in the non-linear regime.

Post, R.F.

2000-02-17T23:59:59.000Z

393

MagneticsLab  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetics Laboratory Magnetics Laboratory Manufacturing Technologies The Magnetics Lab provides customers with design, prototyping, packaging solutions and production of unique magnetic and resistive components from millivolts to extremely high voltage (250KV) components. Capabilities * Design review of specification and requirements * Design and develop from sketches, verbal ideas, or circuit design parameters * Coil windings of any size or configuration * Coil diameter from 0.1 to 24 inches * Low temperature and high temperature coils * Precision resistors from 0.1 ohms to 2 megaohms (non-inductive) * Special high voltage transformers (2KV to 250KV) and high voltage loads (38K ohms to 100K ohms and 2KV to 250KV) Resources * Computer Aided Mechanical Design (Solid Works 3D CAD System) for mechanical

394

AFRD - Superconducting Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Magnets Superconducting Magnets Home Organization Diversity Safety Links Gallery/History Updated July 2008 Ever-stronger magnets (which must be cost-effective as well) are a key to building tomorrow's high-energy accelerators and upgrading today's. Our role— not only a leading R&D group but also the administrators of the multi-institutional National Conductor Development Program— to create both evolutionary improvements and paradigm shifts in the application of accelerator magnets, providing innovative technology that enables new science. Improvements in conductor, innovative structures to solve the challenges of high fields and brittle superconductors, and integration of computerized design and analysis tools are key. The performance requirements of modern accelerators continue to press the

395

Magnetic gripper device  

DOE Patents (OSTI)

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.

1992-12-31T23:59:59.000Z

396

Computing with magnets  

Science Conference Proceedings (OSTI)

Researchers are finding ways to develop ultra-efficient and nonvolatile computer processors out of nanoscale magnets. A number of obstacles, however, stand in the way of their commercialization.

Gary Anthes

2012-03-01T23:59:59.000Z

397

Modular tokamak magnetic system  

DOE Patents (OSTI)

A modular tokamak system comprised of a plurality of interlocking modules. Each module is comprised of a vacuum vessel section, a toroidal field coil, modular saddle coils which generate a poloidal magnetic field and ohmic heating coils.

Yang, Tien-Fang

1986-11-20T23:59:59.000Z

398

SUPERCONDUCTING MAGNET DIVISION  

NLE Websites -- All DOE Office Websites (Extended Search)

MAGNET DIVISION CY 2013 Tier 1 Inspection Schedule Frequency Building Q1 Q2 Q3 Q4 S 902B (Offices) 11713 62013 S 902A (Offices) 11713 62013 Q 902-High Bay Shop 22113 5...

399

Superconducting combined function magnets  

SciTech Connect

Superconducting accelerators and storage rings, presently under construction or in the design phase, are based on separate dipole and quadrupole magnets. It is here suggested that a hybrid lattice configuration consisting of dipoles and combined function gradient magnets would: (1) reduce the number of magnet units and their total cost; and (2) increase the filling factor and thus the energy at a given field. Coil cross sections are presented for the example of the Brookhaven Colliding Beam Accelerator. An asymmetric two-layer cable gradient magnet would have transfer functions of 10.42 G/A and 0.628 G cm/sup -1//A versus 15.77 G/A and 2.03 G cm/sup -1//A of the present separate dipoles and quadrupoles.

Hahn, H.; Fernow, R.C.

1983-01-01T23:59:59.000Z

400

Magnetism in the spiral galaxy NGC 6946: magnetic arms, depolarization rings, dynamo modes and helical fields  

E-Print Network (OSTI)

The spiral galaxy NGC 6946 was observed in total intensity and linear polarization in five radio bands between 3cm and 21cm. At the inner edge of the inner gas spiral arm the ordered magnetic field is only mildly compressed and turns smoothly, to become aligned along the gas arm. Hence the field is not shocked and is probably connected to the warm, diffuse gas. At larger radii, two bright magnetic arms between the optical arms are visible in polarized intensity. The field in the northern magnetic arm is almost totally aligned. Faraday rotation measures (RM) in these arms are consistent with the superposition of two low azimuthal dynamo modes. Three more magnetic arms are discovered in the outer galaxy, located between HI arms. Due to strong Faraday depolarization the galaxy is not transparent to polarized waves at 18cm and 20cm. The large-scale asymmetry in depolarization with respect to the major axis may be another indication of large-scale helical fields. Three depolarization rings of almost zero polarization seen at 20cm are probably generated by differential Faraday rotation in HII complexes in NGC 6946 of 300-500 pc size. - In the gas/optical spiral arms, the total (mostly turbulent) magnetic field is amplified to \\simeq 20\\muG. Its energy density is \\simeq 10 times larger than that of the ionized gas and is similar to that of the turbulent gas motions in the inner galaxy. The magnetic energy exceeds that of the turbulent energy in the outer galaxy.

Rainer Beck

2007-05-29T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Magnetic fluorescent lamp  

DOE Patents (OSTI)

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.

Berman, S.M.; Richardson R.W.

1983-12-29T23:59:59.000Z

402

Microstructure Characterization of Magnetic-Pulse-Welded AA 6061-T6 by Electron Backscattered Diffraction  

Science Conference Proceedings (OSTI)

The grain boundary crystallographic misorientations of magnetic-pulse-welded (MPW) aluminum alloy (AA) 6061-T6 in linear and tubular configurations were examined using the electron backscattered diffraction (EBSD) technique. A refined structure of heavily deformed grains with higher grain boundary angles was observed in linear welds. Significant spalling was observed away from the joints, in the interior of tubular welds. The results show the complex interaction of shock waves with the materials during this impact welding process.

Zhang, Yuan [Ohio State University; Babu, Suresh [Ohio State University; Zhang, P [Edison Welding Institute; Kenik, Edward A [ORNL; Daehn, Glenn [Ohio State University

2008-01-01T23:59:59.000Z

403

LABORATORY VI ELECTRICITY FROM MAGNETISM  

E-Print Network (OSTI)

the magnetic field and its effect on moving charges. You also saw how electric currents could create magnetic the magnetic flux through a coil of wire to produce an electric current. You will investigate the current are necessary for a magnetic field to produce an electric current. · Determine the direction of a current

Minnesota, University of

404

Electronic, Magnetic & Photonic Materials Division  

Science Conference Proceedings (OSTI)

... Committee Energy Conversion and Storage Committee Magnetic Materials Committee Nanomaterials Committee Thin Films and Interfaces Committee.

405

Applicability of the linearly perturbed FRW metric and Newtonian cosmology  

E-Print Network (OSTI)

It has been argued that the effect of cosmological structure formation on the average expansion rate is negligible, because the linear approximation to the metric remains applicable in the regime of non-linear density perturbations. We discuss why the arguments based on the linear theory are not valid. We emphasise the difference between Newtonian gravity and the weak field, small velocity limit of general relativity in the cosmological setting.

Syksy Rasanen

2010-02-25T23:59:59.000Z

406

Freely oriented portable superconducting magnet  

SciTech Connect

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.

Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)

2010-01-12T23:59:59.000Z

407

Modification of {Delta}{sup Prime} by magnetic feedback and kinetic effects  

SciTech Connect

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.

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

408

Deconfinement to quark matter in neutron stars - The influence of strong magnetic fields  

Science Conference Proceedings (OSTI)

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.

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

409

A MODEL FOR DETERMINING DIPOLE, QUADRUPOLE, AND COMBINED FUNCTION MAGNET COSTS.  

SciTech Connect

One of the most important considerations in designing large accelerators is cost. This paper describes a model for estimating accelerator magnet costs, including their dependences on length, radius, and field. The reasoning behind the cost model is explained, and the parameters of the model are chosen so as to correctly give the costs of a few selected magnets. A comparison is made with earlier formulae. Estimates are also given for other costs linearly dependent on length, and for 200 MHz superconducting RF.

PALMER, R.B.; BERG,S.J.

2004-09-14T23:59:59.000Z

410

MAGNETIC NEUTRON SCATTERING  

SciTech Connect

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

ZALIZNYAK,I.A.; LEE,S.H.

2004-07-30T23:59:59.000Z

411

RHIC Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Project RHIC Project The Superconducting Magnet Division supplied 1740 magnetic elements, in 888 cryostats, for the RHIC facility at BNL. Of these, 780 magnetic elements were manufactured by Northrop-Grumman (Bethpage, NY) and 360 were made by Everson Electric (Bethlehem, PA). The magnets made in industry used designs developed at BNL. The first cooldown of the magnets for the RHIC engineering run was in 1999. Since then, the magnets have operated very reliably. arc dipole coil and yoke Arc dipole coil and yoke, with magnetic flux lines The magnets provide modest field (3.45 Teslas in the arc dipoles) in a cost-effective design. Key features in the principal bending and focusing magnets include the use of NbTi Rutherford cable, a single-layer coil, and cold iron as both yoke and collar. The magnets operate in forced-flow

412

Ground Magnetics | Open Energy Information  

Open Energy Info (EERE)

Ground Magnetics Ground Magnetics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Magnetics Details Activities (15) Areas (12) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Magnetic Techniques Parent Exploration Technique: Magnetic Techniques Information Provided by Technique Lithology: Presence of magnetic minerals such as magnetite. Stratigraphic/Structural: Mapping of basement structures, horst blocks, fault systems, fracture zones, dykes and intrusions. Hydrological: The circulation of hydrothermal fluid may impact the magnetic susceptibility of rocks. Thermal: Rocks lose their magnetic properties at the Curie temperature (580° C for magnetite) [1] and, upon cooling, remagnetize in the present magnetic field orientation. The Curie point depth in the subsurface may be determined in a magnetic survey to provide information about hydrothermal activity in a region.

413

Segmented rail linear induction motor - Energy Innovation Portal  

A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The ...

414

Optimization Online - Mixed-Integer Linear Methods for Layout ...  

E-Print Network (OSTI)

Nov 27, 2012 ... Mixed-Integer Linear Methods for Layout-Optimization of Screening ... Abstract: The industrial treatment of waste paper in order to regain...

415

Nonconvergence of the plain Newton-min algorithm for linear ...  

E-Print Network (OSTI)

Apr 7, 2010 ... accounts on the use of interior point methods to solve linear ...... mineral precipitation-dissolution reactions by a semismooth Newton method.

416

the matricial relaxation of a linear matrix inequality - Optimization ...  

E-Print Network (OSTI)

There does not seem to exist a clean linear Nichtnegativstellensatz. We found ... techniques to commuting variables and derive a clean classical Putinar...

417

ESS 2012 Peer Review - Linear Analysis of Power Electronics for...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Linear Analysis of Power Electronics for Energy Storage Systems Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly...

418

Free piston variable-stroke linear-alternator generator ...  

A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The ...

419

The Klynac: An Integrated Klystron and Linear Accelerator  

SciTech Connect

The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system

Potter, J. M., Schwellenbach, D., Meidinger, A.

2012-08-07T23:59:59.000Z

420

Solution of a Linearized Model of Heisenberg's Fundamental Equation II  

E-Print Network (OSTI)

A linearized version of Heisenberg's fundamental equation is solved, and the solutions satisfy the axioms of a relativistic quantum field theory with a fundamental length.

E. Brning; S. Nagamachi

2008-04-11T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

On linear infeasibility arising in intensity-modulated radiation ...  

E-Print Network (OSTI)

Nov 5, 2007 ... Abstract: Intensity--modulated radiation therapy (IMRT) gives rise to systems of linear inequalities, representing the effects of radiation on the...

422

Lattice based extended formulations for integer linear equality systems  

E-Print Network (OSTI)

Feb 28, 2007 ... Lattice based extended formulations for integer linear equality systems. Karen Aardal (karen.aardal ***at*** cwi.nl) Laurence A. Wolsey (wolsey...

423

Math 22a Linear Algebra Information for students, Fall 2009  

E-Print Network (OSTI)

://people.brandeis.edu/~kleinboc/Math22a/intro.html Grader: TBA Text: LINEAR ALGEBRA, 3rd edition, by J. Fraleigh and R. Beauregard

Kleinbock, Dmitry

424

Mixed-Integer Models for Nonseparable Piecewise Linear ...  

E-Print Network (OSTI)

55. Society for Industrial and Applied Mathematics. Wilson, D. L. 1998. Polyhedral methods for piecewise-linear functions. Ph.D. thesis, University of Kentucky.

425

Influence of primordial magnetic fields on 21 cm emission  

E-Print Network (OSTI)

Magnetic fields in the early universe can significantly alter the thermal evolution and the ionization history during the dark ages. This is reflected in the 21 cm line of atomic hydrogen, which is coupled to the gas temperature through collisions at high redshifts, and through the Wouthuysen-Field effect at low redshifts. We present a semi-analytic model for star formation and the build-up of a Lyman alpha background in the presence of magnetic fields, and calculate the evolution of the mean 21 cm brightness temperature and its frequency gradient as a function of redshift. We further discuss the evolution of linear fluctuations in temperature and ionization in the presence of magnetic fields and calculate the effect on the 21 cm power spectrum. At high redshifts, the signal is increased compared to the non-magnetic case due to the additional heat input into the IGM from ambipolar diffusion and the decay of MHD turbulence. At lower redshifts, the formation of luminous objects and the build-up of a Lyman alpha background can be delayed by a redshift interval of 10 due to the strong increase of the filtering mass scale in the presence of magnetic fields. This tends to decrease the 21 cm signal compared to the zero-field case. In summary, we find that 21 cm observations may become a promising tool to constrain primordial magnetic fields.

Dominik R. G. Schleicher; Robi Banerjee; Ralf S. Klessen

2008-08-11T23:59:59.000Z

426

Stabilization of the Rayleigh-Taylor instability in quantum magnetized plasmas  

Science Conference Proceedings (OSTI)

In this research, stabilization of the Rayleigh-Taylor instability (RTI) due to density gradients, magnetic fields, and quantum effects, in an ideal incompressible plasma, is studied analytically and numerically. A second-order ordinary differential equation (ODE) for the RTI including quantum corrections, with a continuous density profile, in a uniform external magnetic field, is obtained. Analytic expressions of the linear growth rate of the RTI, considering modifications of density gradients, magnetic fields, and quantum effects, are presented. Numerical approaches are performed to solve the second-order ODE. The analytical model proposed here agrees with the numerical calculation. It is found that the density gradients, the magnetic fields, and the quantum effects, respectively, have a stabilizing effect on the RTI (reduce the linear growth of the RTI). The RTI can be completely quenched by the magnetic field stabilization and/or the quantum effect stabilization in proper circumstances leading to a cutoff wavelength. The quantum effect stabilization plays a central role in systems with large Atwood number and small normalized density gradient scale length. The presence of external transverse magnetic fields beside the quantum effects will bring about more stability on the RTI. The stabilization of the linear growth of the RTI, for parameters closely related to inertial confinement fusion and white dwarfs, is discussed. Results could potentially be valuable for the RTI treatment to analyze the mixing in supernovas and other RTI-driven objects.

Wang, L. F.; Ye, W. H.; He, X. T. [HEDPS and CAPT, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Yang, B. L. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Graduate School, China Academy of Engineering Physics, Beijing 100088 (China)

2012-07-15T23:59:59.000Z

427

GSI Rapid Cycling Magnets Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

GSI Rapid Cycling Magnets Project GSI Rapid Cycling Magnets Project While superconducting magnets easily achieve higher magnetic fields at lower cost than conventional electromagnets, it is very difficult to ramp superconducting magnets very quickly. But exactly that is needed at the planned new facility of GSI, the Gesellschaft für Schwerionenforschung (Institute for Heavy Ion Research), in Darmstadt, Germany. In the magnets of the SIS 200 ring, one of the components of the new facility, the magnetic field must be ramped from 0.5 Tesla to 4 Tesla at a rate of 1 Tesla per second. This ramp rate is almost 25 times faster than the ramp rate of the Relativistic Heavy Ion Collider (RHIC) magnets at Brookhaven National Lab (BNL), which ramp at a rate of 0.042 Tesla per second. While the SIS 200 magnets also require a slightly higher field strength than the

428

Stability of the toroidal magnetic field in rotating stars  

E-Print Network (OSTI)

The magnetic field in stellar radiation zones can play an important role in phenomena such as mixing, angular momentum transport, etc. We study the effect of rotation on the stability of a predominantly toroidal magnetic field in the radiation zone. In particular we considered the stability in spherical geometry by means of a linear analysis in the Boussinesq approximation. It is found that the effect of rotation on the stability depends on a magnetic configuration. If the toroidal field increases with the spherical radius, the instability cannot be suppressed entirely even by a very fast rotation. Rotation can only decrease the growth rate of instability. If the field decreases with the radius, the instability has a threshold and can be completey suppressed.

Bonanno, Alfio

2013-01-01T23:59:59.000Z

429

Non-axisymmetric instability of axisymmetric magnetic fields  

E-Print Network (OSTI)

The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this paper, we concentrate mainly on the behavior of non-axisymmetric perturbations in axisymmetric magnetic configurations. The stability is treated by a linear analysis of ideal MHD equations.In the presence of an axial field, it is shown that the instability can occur for a wide range of the azimuthal wavenumber $m$, and its growth rate increases with increasing $m$. At given $m$, the growth rate is at its maximum for perturbations with the axial wave-vector that makes the Alfv\\'en frequency approximately vanishing. We argue that the instability of magnetic configurations in the ideal MHD can typically be dominated by perturbations with very short azimuthal and axial wavelengths.

Bonanno, Alfio

2008-01-01T23:59:59.000Z

430

Linear Gain for the Microbunching Instability in an RF Compressor  

E-Print Network (OSTI)

Instability in an RF Compressor M. Venturini Lawrencefor investigating this instability in rf compressors. We useapplied to magnetic compressors [2, 3] and derive some

Venturini, M.

2010-01-01T23:59:59.000Z

431

R&D ERL: Magnetic measurements of the ERL magnets  

SciTech Connect

The magnet system of ERL consists of G5 solenoids, 6Q12 quadrupoles with 0.58 T/m gradient, 3D60 dipoles with 0.4 T central field, 15 and 30 degree Z-bend injection line dipole/quadrupole combined function magnets, and extraction line magnets. More details about the magnets can be found in a report by G. Mahler. Field quality in all the 6Q12 quadrupoles, 3D60 dipoles and the injection line magnets has been measured with either a rotating coil, or a Hall probe mapper. This report presents the results of these magnetic measurements.

Jain, A.

2010-08-01T23:59:59.000Z

432

Magnets and Power Supplies  

NLE Websites -- All DOE Office Websites (Extended Search)

Bibliography Up: APS Storage Ring Parameters Previous: Longitudinal Bibliography 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 supplies 1 Magnetic length 3.06 m Core length 3.00 m Bending radius 38.9611 m Power supply limit 500.0 A Field at 7 GeV 0.599 T Dipole trim coils Number 80+1 No. of power supplies 80 Magnetic length 3.06 m Core length 3.00 m Power supply limit 20.0 A Maximum field 0.04 T Horizontal Correction Dipoles Number 317 No. of power supplies 317 Magnetic length 0.160 m Core length 0.07 m Power supply limit 150.0 A Maximum field 0.16 T Max. deflection at 7 GeV 1.1 mrad Vertical Corrector Dipoles Number 317 No. of power supplies 317

433

Magnetic reconnection launcher  

DOE Patents (OSTI)

An electromagnetic launcher includes a plurality of electrical stages which are energized sequentially in synchrony with the passage of a projectile. 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 by magnetic reconnection as the gap portion 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 at both the rear vertical surface of 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 and fit loosely within the gap between the opposing coils.

Cowan, Maynard (Albuquerque, NM)

1989-01-01T23:59:59.000Z

434

Active magnetic regenerator  

DOE Patents (OSTI)

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)

Barclay, J.A.; Steyert, W.A.

1981-01-27T23:59:59.000Z

435

Pipelining with common operands for power-efficient linear systems  

Science Conference Proceedings (OSTI)

We propose a systematic pipelining method for a linear system to minimize power and maximize throughput, given a constraint on the number of pipeline stages and a set of resource constraints. Unlike most existing pipelining approaches, our method takes ... Keywords: common operand, linear system, operand sharing, pipelining, power

Daehong Kim; Dongwan Shin; Kiyoung Choi

2005-09-01T23:59:59.000Z

436

Drift tube suspension for high intensity linear accelerators  

DOE Patents (OSTI)

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

1980-03-11T23:59:59.000Z

437

Non-linear image representation based on IDP with NN  

Science Conference Proceedings (OSTI)

In this paper is offered a method for non-linear still image representation based on pyramidal decomposition with a neural network. This approach is developed by analogy with the hypothesis for the way humans do image recognition using consecutive approximations ... Keywords: neural networks, non-linear image representation, pyramidal decomposition

Roumen Kountchev; Stuart Rubin; Mariofanna Milanova; Vladimir Todorov; Roumiana Kountcheva

2009-09-01T23:59:59.000Z

438

Brief paper: Axiomatic characterization of linear differential systems (and operators)  

Science Conference Proceedings (OSTI)

In his IEEE Trans. Aut. Contr. paper in 1991, Willems posed the following question: given a set of smooth trajectories, when does there exist a linear constant coefficient differential operator whose kernel is precisely the given set? We show that the ... Keywords: Jet-closed, Jet-determined, Jets, LTID systems, Linear differential operators, t-adic topologies

Vakhtang Lomadze

2012-05-01T23:59:59.000Z

439

Goodness-of-fit tests in semi-linear models  

Science Conference Proceedings (OSTI)

Specification tests for the error distribution are proposed in semi-linear models, including the partial linear model and additive models. The tests utilize an integrated distance involving the empirical characteristic function of properly estimated ... Keywords: Bootstrap test, Empirical characteristic function, Goodness-of-fit test, Semiparametric model, Symmetry test

Simos G. Meintanis; Jochen Einbeck

2012-07-01T23:59:59.000Z

440

Exact distribution of individual displacements in linear probing hashing  

Science Conference Proceedings (OSTI)

This paper studies the distribution of individual displacements for the standard and the Robin Hood linear probing hashing algorithms. When the a table of size m has n elements, the distribution of the search cost of a random element is ... Keywords: Linear probing, distributional analysis, individual displacements

Alfredo Viola

2005-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Computation of the constrained infinite time linear quadratic regulator  

Science Conference Proceedings (OSTI)

This paper presents an efficient algorithm for computing the solution to the constrained infinite-time, linear quadratic regulator (CLQR) problem for discrete time systems. The algorithm combines multi-parametric quadratic programming with reachability ... Keywords: Constrained infinite horizon control, Invariant Set, Linear quadratic regulator, Model predictive control

Pascal Grieder; Francesco Borrelli; Fabio Torrisi; Manfred Morari

2004-04-01T23:59:59.000Z

442

FirstOrder Representations of Discrete Linear MultidimensionalSystems  

Science Conference Proceedings (OSTI)

The classical local statespace models for discrete multidimensional linear systems, as proposed by Roesser or Fornasini and Marchesini, require causality of the resulting transfer matrices. We consider a generalization comprising non-causal ... Keywords: (Laurent) polynomial matrices, behavior, first, input, kernel and image representation, linear fractional transformation, minimality, order representation, output structure, properness

Eva Zerz

2000-10-01T23:59:59.000Z

443

Dynamic linear combination of two-class classifiers  

Science Conference Proceedings (OSTI)

In two-class problems, the linear combination of the outputs (scores) of an ensemble of classifiers is widely used to attain high performance. In this paper we investigate some techniques aimed at dynamically estimate the coefficients of the linear combination ... Keywords: biometric systems, classifier ensembles, two-class classification

Carlo Lobrano; Roberto Tronci; Giorgio Giacinto; Fabio Roli

2010-08-01T23:59:59.000Z

444

The generalized HSS method for solving singular linear systems  

Science Conference Proceedings (OSTI)

For the singular, non-Hermitian, and positive semidefinite linear systems, we propose an alternating-direction iterative method with two parameters based on the Hermitian and skew-Hermitian splitting. The semi-convergence analysis and the quasi-optimal ... Keywords: Hermitian and skew-Hermitian splitting, Iterative method, Non-Hermitian matrix, Positive semidefinite matrix, Semi-convergence, Singular linear system

Wen Li; Yang-Peng Liu; Xiao-Fei Peng

2012-03-01T23:59:59.000Z

445

Optimal control for linear-rate multi-mode systems  

Science Conference Proceedings (OSTI)

Linear-Rate Multi-Mode Systems is a model that can be seen both as a subclass of switched linear systems with imposed global safety constraints and as hybrid automata with no guards on transitions. We study the existence and design of a controller for ...

Dominik Wojtczak

2013-08-01T23:59:59.000Z

446

A Low-Power Wide-Linear-Range Transconductance Amplifier  

Science Conference Proceedings (OSTI)

The linear range of approximately 75 mV of traditional subthreshold transconductance amplifiers is too small for certain applicationsfor example, for filters in electronic cochleas, where it is desirable to handle loud sounds without ... Keywords: amplifier, cochlea, degeneration, dynamic range, low-power, noise, transconductance, wide-linear-range

Rahul Sarpeshkar; Richard F. Lyon; Carver Mead

1997-05-01T23:59:59.000Z

447

Variable-energy drift-tube linear accelerator  

SciTech Connect

A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM); Potter, James M. (Los Alamos, NM); Stovall, James E. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

448

Drift tube suspension for high intensity linear accelerators  

SciTech Connect

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, Donald J. (Los Alamos, NM); Schamaun, Roger G. (Los Alamos, NM); Clark, Donald C. (Los Alamos, NM); Potter, R. Christopher (Los Alamos, NM); Frank, Joseph A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

449

Linear and nonlinear degenerate boundary value problems in Besov spaces  

Science Conference Proceedings (OSTI)

The boundary value problems for linear and nonlinear degenerate differential-operator equations in Banach-valued Besov spaces are studied. Several conditions for the separability of linear elliptic problems are given. Moreover, the positivity and the ... Keywords: Banach-valued Besov spaces, Boundary value problems, Differential-operator equations, Interpolation of Banach spaces, Operator-valued multipliers

Veli B. Shakhmurov; Ravi P. Agarwal

2009-03-01T23:59:59.000Z

450

Towards dense linear algebra for hybrid GPU accelerated manycore systems  

Science Conference Proceedings (OSTI)

We highlight the trends leading to the increased appeal of using hybrid multicore+GPU systems for high performance computing. We present a set of techniques that can be used to develop efficient dense linear algebra algorithms for these systems. We illustrate ... Keywords: Dense linear algebra, Graphics processing units, Hybrid computing, Multicore processors, Parallel algorithms

Stanimire Tomov; Jack Dongarra; Marc Baboulin

2010-06-01T23:59:59.000Z

451

Linear Models: Useful Tools to Analyze GCM Results  

Science Conference Proceedings (OSTI)

Using a two-level linear, steady state model, we diagnose the 40-day mean response of a GCM to a tropical sea surface temperature (SST) anomaly. The time-mean anomalies produced by the GCM are simulated as linear response to the anomalous ...

C. J. Kok; J. D. Opsteegh; H. M. van den Dool

1987-09-01T23:59:59.000Z

452

Fitting a Linear Autoregressive Model for Long-Range Forecasting  

Science Conference Proceedings (OSTI)

Methods of fitting a linear autoregressive model to a stationary time series are summarized. Parameters of the linear autoregressive model were estimated by the Durbin stepwise procedure and the order of this model was chosen by means of a t-test ...

C. S. Yao

1983-04-01T23:59:59.000Z

453

Robust likelihood inference for regression parameters in partially linear models  

Science Conference Proceedings (OSTI)

A robust likelihood approach is proposed for inference about regression parameters in partially-linear models. More specifically, normality is adopted as the working model and is properly corrected to accomplish the objective. Knowledge about the true ... Keywords: Generalized additive models, Partially-linear models, Robust likelihood

Chung-Wei Shen; Tsung-Shan Tsou; N. Balakrishnan

2011-04-01T23:59:59.000Z

454

Minimal Realizations of Linear Systems: The "Shortest Basis" Approach  

E-Print Network (OSTI)

Given a discrete-time linear system C, a shortest basis for C is a set of linearly independent generators for C with the least possible lengths. A basis B is a shortest basis if and only if it has the predictable span ...

Forney, G. David, Jr.

455

Reorientation of linear switched systems using state feedback  

Science Conference Proceedings (OSTI)

A characterisation is obtained for the controlled and conditioned invariants of a linear switched system under feedback. The existence of a maximal consistent subspace with feedback is shown and is computed. A few sufficient conditions under which the ... Keywords: Consistent subspace, Jump subspace, Linear complementarity systems, State feedback, Switched systems, Well-posedness

H. Priyadarshan, Harish K. Pillai

2013-06-01T23:59:59.000Z

456

On the modulus algorithm for the linear complementarity problem  

Science Conference Proceedings (OSTI)

Concerning three subclasses of P-matrices the modulus algorithm and the projected successive overrelaxation (PSOR) method solving the linear complementarity problem are compared to each other with respect to convergence. It is shown that the modulus ... Keywords: H-matrix, Linear complementarity problem, P-matrix, PSOR method

Uwe SchFer

2004-07-01T23:59:59.000Z

457

Linear-optics manipulations of photon-loss codes  

E-Print Network (OSTI)

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

Konrad Banaszek; Wojciech Wasilewski

2007-02-09T23:59:59.000Z

458

Magnetic Techniques | Open Energy Information  

Open Energy Info (EERE)

Magnetic Techniques Magnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Magnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Magnetic Techniques Parent Exploration Technique: Geophysical Techniques Information Provided by Technique Lithology: Presence of magnetic minerals such as magnetite. Stratigraphic/Structural: Mapping of basement structures, horst blocks, fault systems, fracture zones, dykes and intrusions. Hydrological: The circulation of hydrothermal fluid may impact the magnetic susceptibility of rocks. Thermal: Rocks lose their magnetic properties at the Curie temperature (580° C for magnetite) [1] and, upon cooling, remagnetize in the present magnetic field orientation. The Curie point depth in the subsurface may be determined in a magnetic survey to provide information about hydrothermal activity in a region.

459

Linear Concentrator System Basics for Concentrating Solar Power |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Linear Concentrator System Basics for Concentrating Solar Power Linear Concentrator System Basics for Concentrating Solar Power Linear Concentrator System Basics for Concentrating Solar Power August 20, 2013 - 4:45pm Addthis Photo of numerous parallel rows of parabolic trough collectors tracking the sun. Cooling towers and other generator equipment are in the midst of the troughs, and two water tanks are in the background. The Solar Electric Generating Station IV power plant in California consists of many parallel rows of parabolic trough collectors that track the sun. The cooling towers can be seen with the water plume rising into the air, and white water tanks are in the background. Credit: Sandia National Laboratory / PIX 14955 Linear concentrating solar power (CSP) collectors capture the sun's energy with large mirrors that reflect and focus the sunlight onto a linear

460

MHK Technologies/The Linear Generator | Open Energy Information  

Open Energy Info (EERE)

Linear Generator Linear Generator < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage The Linear Generator.jpg Technology Profile Primary Organization Trident Energy Ltd Project(s) where this technology is utilized *MHK Projects/TE4 Technology Resource Click here Wave Technology Type Click here Point Absorber Technology Readiness Level Click here TRL 1-3: Discovery / Concept Definition / Early Stage Development & Design & Engineering Technology Description The simplicity of the Trident Energy solution is based around the fact that the system has only one moving part - float / linear generator translator, which is powered by the motion of floats placed in the sea. As waves pass through the wavefarm, so the floats rise and fall. This causes relative motion between the two components of the linear generator (the translator and stator) and electricity is immediately generated. There is absolutely no contact between the two parts of the generator as the energy conversion is entirely electromagnetic.

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Purely magnetic spacetimes  

E-Print Network (OSTI)

Spacetimes in which the electric part of the Weyl tensor vanishes (relative to some timelike unit vector field) are said to be purely magnetic. Examples of purely magnetic spacetimes are known and are relatively easy to construct, if no restrictions are placed on the energy-momentum tensor. However it has long been conjectured that purely magnetic vacuum spacetimes (with or without a cosmological constant) do not exist. The history of this conjecture is reviewed and some advances made in the last year are described briefly. A generalisation of this conjecture first suggested for type D vacuum spacetimes by Ferrando and Saez is stated and proved in a number of special cases. Finally an approach to a general proof of the conjecture is described using the Newman-Penrose formalism based on a canonical null tetrad of the Weyl tensor.

Alan Barnes

2004-01-15T23:59:59.000Z

462

Superconducting magnetic coil  

DOE Patents (OSTI)

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.

Aized, D.; Schwall, R.E.

1999-06-22T23:59:59.000Z

463

Wave breaking phenomenon of lower-hybrid oscillations induced by a background inhomogeneous magnetic field  

Science Conference Proceedings (OSTI)

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.

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

464

Requirements of Magnetic Materials for Current Technological ...  

Science Conference Proceedings (OSTI)

Mar 3, 2011 ... Magnetic Materials for Energy Applications: Requirements of Magnetic ... Hard magnetic materials play a significant role in many green...

465

Experiment #7: Magnetic Deflection of Beta Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

of magnetism. Materials Geiger counter Wooden block (to hold the source) Aluminum shield with hole (for Geiger counter) Two cow magnets Magnet holders Sr-90 (beta source)...

466

Magnetic imaging of shipwrecks  

E-Print Network (OSTI)

The ferromagnetic material in a shipwreck on the seabed causes a modification to the earth's magnetic field which can be measured at the surface. Proton magnetometer measurements at the surface are used to locate wrecks. Here I discuss how to interpret such data to explore the shape and orientation of the shipwreck on the seabed. I give details of how to model shipwrecks and deduce the magnetic signal that results. I also discuss how to analyse data in a more general way. As examples, I present and analyse data on the shipwrecks of YSTROOM and BOUBOULINA (ex COLONEL LAMB).

Michael, C

2011-01-01T23:59:59.000Z

467

The solar magnetic field  

E-Print Network (OSTI)

The magnetic field of the Sun is the underlying cause of the many diverse phenomena combined under the heading of solar activity. Here we describe the magnetic field as it threads its way from the bottom of the convection zone, where it is built up by the solar dynamo, to the solar surface, where it manifests itself in the form of sunspots and faculae, and beyond into the outer solar atmosphere and, finally, into the heliosphere. On the way it, transports energy from the surface and the subsurface layers into the solar corona, where it heats the gas and accelerates the solar wind.

Solanki, Sami K; Schssler, Manfred; 10.1088/0034-4885/69/3/R02

2010-01-01T23:59:59.000Z

468

Fast superconducting magnetic field switch  

DOE Patents (OSTI)

The superconducting magnetic switch or fast kicker magnet is employed with an electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater than the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. Magnetic switches and particularly fast kicker magnets are used in the accelerator industry to quickly deflect particle beams into and out of various transport lines, storage rings, dumps, and specifically to differentially route individual bunches of particles from a train of bunches which are injected or ejected from a given ring.

Goren, Y.; Mahale, N.K.

1995-12-31T23:59:59.000Z

469

Results from a Prototype Chicane-Based Energy Spectrometer for a Linear Collider  

E-Print Network (OSTI)

The International Linear Collider and other proposed high energy e+ e- machines aim to measure with unprecedented precision Standard Model quantities and new, not yet discovered phenomena. One of the main requirements for achieving this goal is a measurement of the incident beam energy with an uncertainty close to 1e-4. This article presents the analysis of data from a prototype energy spectrometer commissioned in 2006--2007 in SLAC's End Station A beamline. The prototype was a 4-magnet chicane equipped with beam position monitors measuring small changes of the beam orbit through the chicane at different beam energies. A single bunch energy resolution close to 5e-4 was measured, which is satisfactory for most scenarios. We also report on the operational experience with the chicane-based spectrometer and suggest ways of improving its performance.

A. Lyapin; H. J. Schreiber; M. Viti; C. Adolphsen; R. Arnold; S. Boogert; G. Boorman; M. V. Chistiakova; F. Gournaris; V. Duginov; C. Hast; M. D. Hildreth; C. Hlaing; F. Jackson; O. Khainovsky; Yu. G. Kolomensky; S. Kostromin; K. Kumar; B. Maiheu; D. McCormick; D. J. Miller; N. Morozov; T. Orimoto; E. Petigura; M. Sadre-Bazzaz; M. Slater; Z. Szalata; M. Thomson; D. Ward; M. Wendt; M. Wing; M. Woods

2010-11-01T23:59:59.000Z

470

Divertor conditions relevant for fusion reactors achieved with linear plasma generator  

Science Conference Proceedings (OSTI)

Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6 Multiplication-Sign 10{sup 20} m{sup -3} and electron temperatures up to 3.7 eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4 MW m{sup -2} and 10{sup 24} m{sup -2} s{sup -1}, respectively. We have shown that the plasma surface interactions are dominated by the incoming ions. The achieved conditions correspond very well to the projected conditions at the divertor strike zones of fusion reactors such as ITER. In addition, the machine has an unprecedented high gas efficiency.

Eck, H. J. N. van; Lof, A.; Meiden, H. J. van der; Rooij, G. J. van; Scholten, J.; Zeijlmans van Emmichoven, P. A. [FOM Institute DIFFER - Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Kleyn, A. W. [FOM Institute DIFFER - Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Van't Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam (Netherlands)

2012-11-26T23:59:59.000Z

471

Low energy improvements to the Fermilab 400-MeV linear accelerator  

SciTech Connect

Improvements in the Fermilab operating 400-MeV linear accelerator injector are required to achieve the beam intensity and emittance requirement of the Proton Driver design study [5]. It has been determined that these requirements can be achieved by replacing the components in the Linac below 10 MeV. An improved H{sup {minus}} ion source with an electrostatic transport to a two-section Radio-Frequency Quadrupole (RFQ) accelerator, with the RFQ sections separated by a magnetic five-dimensional phase-space imaging system as used in an earlier Fermilab/SAIC PET Project, and a new 10-MeV drift-tube linac cavity have been studied. It appears possible that an H{sup {minus}} intensity of 4.5 x 10{sup 13} ions per pulse with an improvement in beam emittance from the present system can be achieved with the proposed changes.

Don E. Young et al.

2001-07-02T23:59:59.000Z

472

ANALYSIS OF HIGH FIELD NON-LINEAR LOSSES ON SRF SURFACES DUE TO SPECIFIC TOPOGRAPHIC ROUGHNESS  

Science Conference Proceedings (OSTI)

The high-field performance of SRF cavities will eventually be limited by the realization of fundamental material limits, whether it is Hc1 or Hsh, or some derivative thereof, at which the superconductivity is lost. Before reaching this fundamental field limit at the macro level, it must be encountered at localized, perhaps microscopic, sites of field enhancement due to local topography. If such sites are small enough, they may produce thermally stabilized normal-conducting regions which contribute non-linear losses when viewed from the macro resonant field perspective, and thus produce degradation in Q0. We have undertaken a calculation of local surface magnetic field enhancement from specific fine topographic structure by conformal mapping method and numerically. A solution of the resulting normal conducting volume has been derived and the corresponding RF Ohmic loss simulated.

Chen Xu,Charles Reece,Michael Kelley

2012-07-01T23:59:59.000Z

473

Linear and nonlinear coupled drift and ion acoustic waves in collisional pair ion-electron magnetoplasma  

SciTech Connect

Linear and nonlinear coupled electrostatic drift and ion acoustic waves are studied in inhomogeneous, collisional pair ion-electron plasma. The Korteweg-de Vries-Burgers (KdVB) equation for a medium where both dispersion and dissipation are present is derived. An attempt is made to obtain exact solution of KdVB equation by using modified tanh-coth method for arbitrary velocity of nonlinear drift wave. Another exact solution for KdVB is obtained, which gives a structure of shock wave. Korteweg-de Vries (KdV) and Burgers equations are derived in limiting cases with solitary and monotonic shock solutions, respectively. Effects of species density, magnetic field, obliqueness, and the acoustic to drift velocity ratio on the solitary and shock solutions are investigated. The results discussed are useful in understanding of low frequency electrostatic waves at laboratory pair ion plasmas.

Mushtaq, A. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan); School of Physics, University of Sydney, New South Wales 2006 (Australia); Saeed, R.; Haque, Q. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan)

2011-04-15T23:59:59.000Z

474

Linear and nonlinear dynamics of current-driven waves in dusty plasmas  

SciTech Connect

The linear and nonlinear dynamics of a recently proposed plasma mode of dusty plasma is studied using kappa distribution for electrons. This electrostatic wave can propagate in the plasma due to the sheared flow of electrons and ions parallel to the external magnetic field in the presence of stationary dust. The coupling of this wave with the usual drift wave and ion acoustic wave is investigated. D'Angelo's mode is also modified in the presence of superthermal electrons. In the nonlinear regime, the wave can give rise to dipolar vortex structures if the shear in flow is weaker and tripolar vortices if the flow has steeper gradient. The results have been applied to Saturn's magnetosphere corresponding to negatively charged dust grains. But the theoretical model is applicable for positively charged dust as well. This work will be useful for future observations and studies of dusty environments of planets and comets.

Ahmad, Ali [National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Ali Shan, S.; Haque, Q. [National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Saleem, H. [National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan)

2012-09-15T23:59:59.000Z

475

Spin excitations in K2Fe4+xSe5: Linear response approach  

Science Conference Proceedings (OSTI)

Using ab initio linear response techniques we calculate spin-wave spectra in K2Fe4+xSe5, and find them to be in excellent agreement with a recent experiment. The spectrum can be described reasonably well by a localized spin Hamiltonian restricted to first and second nearest neighbor couplings. We confirm that exchange coupling between nearest neighbor Fe magnetic moments is strongly anisotropic, and show directly that in the ideal system this anisotropy has an itinerant nature which can be imitated by introducing higher order terms in the effective localized spin Hamiltonian (biquadratic coupling). In the real system, structural relaxation provides an additional source of the exchange anisotropy of approximately the same magnitude. The dependence of spin-wave spectra on the filling of Fe vacancy sites is also discussed.

Ke, Liqin; van Schilfgaarde, Mark; Antropov, Vladimir

2012-07-17T23:59:59.000Z

476

Preliminary design of linear alternator dynamometer for free piston Stirling engines. Final report  

SciTech Connect

A preliminary design of a linear alternator type dynamometer for testing free piston Stirling engines (FPSEs) is prepared. The purpose of the dynamometer is to provide the FPSEs with simulated loads such as double-acting inertia compressors for heat pumps, hydraulic pumps, and linear alternators. The dynamometer has two major components: the electromechanical transducer and the control system. The electromechanical transducer consists of a light-weight armature coil tube plunger moving in a permanent magnet field provided by cylindrical magnets made of Samarium Cobalt. The electrical connection to the moving armature coil is accomplished using flexible leads made of thin Beryllium Copper strips on thin high-temperature polyamid ribbons and bent in a U shape. The dynamometer control system utilizes active force control scheme and consists of a microprocessor-based, negative-feedback, control system and the power supply capable of supplying to and absorbing power from the electromechanical transducer. The control system operates in two modes simultaneously: the foreground mode and the background mode. The foreground mode instantaneously regulates the current to the armature coil according to the predetermined load force profile. The background mode continually refines the load force profile and upgrades the foreground mode load force profile until convergence is reached. The digital simulation of the entire system including the control system, the dynamometer, and the RE-1000 FPSE showed that the dynamometer is capable of simulating various loads very accurately and fast. It is expected that experimental investigations of FPSEs operating with the dynamometer-simulated loads will help to accurately predict the FPSEs' performance characteristics under actual load conditions. The dynamometer would also help to design a more suitable load device for a particular application. 10 refs.

Lee, K.P.; Toscano, W.M.

1985-06-01T23:59:59.000Z

477

Moving Magnet Series with  

E-Print Network (OSTI)

material allows for exceptional flux densi- ties in the air gap. The intense magnetic field strengthV/Degree/Second, +/-10% Current, RMS 2.3 2.4 4.1 3.9 A, Maximum Current, Peak 6 8 20 20 A, Maximum Small Angle Step

Kleinfeld, David

478

Rotary magnetic heat pump  

DOE Patents (OSTI)

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.

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

479

Permanent Magnet Materials  

Science Conference Proceedings (OSTI)

Table 4   Applications of permanent magnet materials...material Primary reason for selection Alternative material Condition or reason favoring selection of alternative material Aircraft magnetos, military or civilian SmCo Maximum energy per unit volume Cast Alnico 5 Availability or cost restraint Alternators SmCo Compactness and reliability Ferrite...

480

National Magnetic Anomaly Map  

DOE Green Energy (OSTI)

A record of the conclusions of a three-day meeting and workshop of the Committee for a National Magnetic Anomaly Map held in February 1976 is presented. The purpose of he workshop was to prepare a statement of the benefits, objectives, specifications, and requirements of a NMAM and establish a working plan for producing the map. (ACR)

Not Available

1976-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic linear dichroism" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Magnetic resonance apparatus  

SciTech Connect

Means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial component of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.

Jackson, Jasper A. (Los Alamos, NM); Cooper, Richard K. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

482

Permanent Magnet Materials  

Science Conference Proceedings (OSTI)

Table 4 Applications of permanent magnet materials...material Primary reason for selection Alternative material Condition or reason favoring selection of alternative material Aircraft magnetos, military or civilian SmCo Maximum energy per unit volume Cast Alnico 5 Availability or cost restraint Alternators SmCo Compactness and reliability Ferrite...

483

Rotary magnetic heat pump  

DOE Patents (OSTI)

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, L.D.

1987-02-11T23:59:59.000Z

484

Magnetic refrigeration apparatus and method  

SciTech Connect

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.

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

485

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Wednesday, 28 March 2012 00:00 Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

486

Development of a Toolkit for Calculating Linear, Change-Point Linear and Multiple-Linear Inverse Building Energy Analysis Models, ASHRAE Research Project 1050-RP, Final Report  

E-Print Network (OSTI)

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 application for developing regression models of building energy use. IMT can identify single and multi-variable least-squares regression models. It can also identify variable-base degree-day and single and multi-variable change-point models, which have been shown to be especially useful for modeling building energy use. This report includes background information about IMT and the models, instructions for its installation and operation, and the results of accuracy and robustness testing.

Kissock, J. K.; Haberl, J. S.; Claridge, D. E.

2002-11-01T23:59:59.000Z

487

The effect of linear terms in a quadratic Hamiltonian  

E-Print Network (OSTI)

For a non-relativistic particle subject to a Hamiltonian that is quadratic in position and momentum, with coefficients that may vary with time, it is shown that the effect of the linear terms in the Hamiltonian is just a spatial translation of the wave function and a change in its phase. The shifts in position and phase can be expressed in terms of classical trajectories. This simple effect of the linear terms is related to the fact that all moments about the centroid of the wave function evolve independently of the linear terms.

Mark Andrews

2009-06-19T23:59:59.000Z

488

Asynchronous parallel generating set search for linearly-constrained optimization.  

SciTech Connect

Generating set search (GSS) is a family of direct search methods that encompasses generalized pattern search and related methods. We describe an algorithm for asynchronous linearly-constrained GSS, which has some complexities that make it different from both the asynchronous bound-constrained case as well as the synchronous linearly-constrained case. The algorithm has been implemented in the APPSPACK software framework and we present results from an extensive numerical study using CUTEr test problems. We discuss the results, both positive and negative, and conclude that GSS is a reliable method for solving small-to-medium sized linearly-constrained optimization problems without derivatives.

Lewis, Robert Michael (; ); Griffin, Joshua D.; Kolda, Tamara Gibson

2006-08-01T23:59:59.000Z

489

Magnetic Devices and Nanostructures (2005)  

Science Conference Proceedings (OSTI)

... Molecular nanomagnets, which are the smallest well defined magnetic ... moment of a specimen as microwave stimulation causes resonance at ...

2010-10-13T23:59:59.000Z

490

Evolution of twisted magnetic fields  

SciTech Connect

The magnetic field of the solar corona evolves quasistatically in response to slowly changing photospheric boundary conditions. The