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Sample records for astrid-2 emma magnetic

  1. Astrid-2 EMMA Magnetic Calibration

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Risbo, Torben

    1998-01-01

    The Swedish micro-satellite Astrid-2 contains a tri-axial fluxgate magnetometer with the sensor co-located with a Technical University of Denmark (DTU) star camera for absolute attitude, and extended about 0.9 m on a hinged boom. The magnetometer is part of the RIT EMMA electric and magnetic fields...... experiment built as a collaboration between the DTU, Department of Automation and the Department of Plasma Physics, The Alfvenlaboratory, Royal Institute of Technology (RIT), Stockholm. The final magnetic calibration of the Astrid-2 satellite was done at the Lovoe Magnetic Observatory under the Geological...... Survey of Sweden near Stockholm on the night of May 15.-16., 1997. The magnetic calibration and the intercalibration between the star camera and the magnetic sensor was performed by measuring the Earth's magnetic field and simultaneously observing the star sky with the camera. The rotation matrix between...

  2. EMMA - the Electric and Magnetic Monitor of the Aurora on Astrid-2

    Directory of Open Access Journals (Sweden)

    L. G. Blomberg

    2004-01-01

    Full Text Available The Astrid-2 mission has dual primary objectives. First, it is an orbiting instrument platform for studying auroral electrodynamics. Second, it is a technology demonstration of the feasibility of using micro-satellites for innovative space plasma physics research. The EMMA instrument, which we discuss in the present paper, is designed to provide simultaneous sampling of two electric and three magnetic field components up to about 1kHz. The spin plane components of the electric field are measured by two pairs of opposing probes extended by wire booms with a separation distance of 6.7m. The probes have titanium nitride (TiN surfaces, which has proved to be a material with excellent properties for providing good electrical contact between probe and plasma. The wire booms are of a new design in which the booms in the stowed position are wound around the exterior of the spacecraft body. The boom system was flown for the first time on this mission and worked flawlessly. The magnetic field is measured by a tri-axial fluxgate sensor located at the tip of a rigid, hinged boom extended along the spacecraft spin axis and facing away from the Sun. The new advanced-design fluxgate magnetometer uses digital signal processors for detection and feedback, thereby reducing the analogue circuitry to a minimum. The instrument characteristics as well as a brief review of the science accomplished and planned are presented. Key words. Ionosphere (auroral ionosphere. Magnetospheric physics (magnetosphere-ionosphere interactions. Space plasma physics (instruments and techniques

  3. EMMA - the Electric and Magnetic Monitor of the Aurora on Astrid-2

    Directory of Open Access Journals (Sweden)

    L. G. Blomberg

    2004-01-01

    Full Text Available The Astrid-2 mission has dual primary objectives. First, it is an orbiting instrument platform for studying auroral electrodynamics. Second, it is a technology demonstration of the feasibility of using micro-satellites for innovative space plasma physics research. The EMMA instrument, which we discuss in the present paper, is designed to provide simultaneous sampling of two electric and three magnetic field components up to about 1kHz. The spin plane components of the electric field are measured by two pairs of opposing probes extended by wire booms with a separation distance of 6.7m. The probes have titanium nitride (TiN surfaces, which has proved to be a material with excellent properties for providing good electrical contact between probe and plasma. The wire booms are of a new design in which the booms in the stowed position are wound around the exterior of the spacecraft body. The boom system was flown for the first time on this mission and worked flawlessly. The magnetic field is measured by a tri-axial fluxgate sensor located at the tip of a rigid, hinged boom extended along the spacecraft spin axis and facing away from the Sun. The new advanced-design fluxgate magnetometer uses digital signal processors for detection and feedback, thereby reducing the analogue circuitry to a minimum. The instrument characteristics as well as a brief review of the science accomplished and planned are presented.

    Key words. Ionosphere (auroral ionosphere. Magnetospheric physics (magnetosphere-ionosphere interactions. Space plasma physics (instruments and techniques

  4. EMMA - the electric and magnetic monitor of the aurora on Astrid-2

    DEFF Research Database (Denmark)

    Blomberg, L.G.; Marklund, G.T.; Lindqvist, P.A.

    2004-01-01

    discuss in the present paper, is designed to provide simultaneous sampling of two electric and three magnetic field components up to about 1 kHz. The spin plane components of the electric field are measured by two pairs of opposing probes extended by wire booms with a separation distance of 6.7 m....... The probes have titanium nitride (TiN) surfaces. which has proved to be a material with excellent properties for providing good electrical contact between probe and plasma. The wire booms are of a new design in which the booms in the stowed position are wound around the exterior of the spacecraft body...

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

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2005-07-01

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

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

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2005-07-01

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

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

  7. Modelling the Earth's Main Magnetic Field by the spinning Astrid-2 satellite

    DEFF Research Database (Denmark)

    Merayo, Jose Maria Garcia; Jørgensen, Peter Siegbjørn; Risbo, T.

    1999-01-01

    and therefore the mapping of the Earth's magnetic field may be possible. The spinning of the spacecraft about a certain axis makes the stabilisation in space possible. This fact and the well distributed data over the globe makes the magnetic data well suited for the estimation of the magnetic field model......The Swedish micro-satellite Astrid-2 was successfully launched into a near polar orbit last December 98. Despite the fact that its primary mission was the research of Auroral phenomena, the magnetic instrumentation has been designed to accomplish high resolution vector field magnetic measurements...... at the spacecraft altitude (circa 1000km). Several methods for field modelling are presented in this paper with the assumption that the direction of the spin axis is nearly constant. In any case the orientation of the magnetometer is to bedetermined simultaneously with the instrument calibration and main field...

  8. Emma

    NARCIS (Netherlands)

    Austen, Jane

    2005-01-01

    When Emma Woodhouse sets out on a career of match-making in the little town of Highbury she manages to cause confusion at every step. Jane Austen was particularly proud of Emma, in which she takes apart the desires and foibles of small-town society with unnerving accuracy.

  9. The spinning Astrid-2 satellite used for modeling the Earth's main magnetic field

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Jørgensen, P.S.; Risbo, T.

    2002-01-01

    orientation of the magnetometer could then be determined simultaneously with the instrument intrinsic calibration and the estimate of main field model coefficients. Hence, apart from the scientific use of the magnetic data, the attitude of the spacecraft may be estimated with high precision....

  10. Digital fluxgate magnetometer for the "Astrid-2" satellite

    DEFF Research Database (Denmark)

    Pedersen, Erik Bøje; Primdahl, Fritz; Petersen, Jan Raagaard

    1999-01-01

    The design and performance of the Astrid-2 magnetometer are described. The magnetometer uses mathematical routines implemented by software for commercially available digital dignal processors to determine the magnetic field from the fluxgate sensor. The sensor is from the latest generation of amo...

  11. Statistics of Joule heating in the auroral zone and polar cap using Astrid-2 satellite Poynting flux

    Directory of Open Access Journals (Sweden)

    A. Olsson

    2004-12-01

    Full Text Available We make a statistical study of ionospheric Joule heating with the Poynting flux method using six months of Astrid-2/EMMA electric and magnetic field data during 1999 (solar maximum year. For the background magnetic field we use the IGRF model. Our results are in agreement with earlier statistical satellite studies using both the ΣPE2 method and the Poynting flux method. We present a rather comprehensive set of fitted Joule heating formulas expressing the Joule heating in given magnetic local time (MLT and invariant latitude (ILAT range under given solar illumination conditions as a function of the Kp index, the AE index, the Akasofu epsilon parameter and the solar wind kinetic energy flux. The study thus provides improved and more detailed estimates of the statistical Joule heating. Such estimates are necessary building blocks for future quantitative studies of the power budget in the magnetosphere and in the nightside auroral region. Key words. Ionosphere (electric fields and currents; ionosphere-magnetosphere interactions – Magnetospheric physics (magnetospheric configuration and dynamics

  12. Astrid-2, an advanced microsatellite for auroral research

    Directory of Open Access Journals (Sweden)

    G. T. Marklund

    Full Text Available The successful launch of the Swedish microsatellite Astrid-2 in December 1998 began a new era of auroral research, with advanced microprobes of 30 kg or less used as research tools. Innovative technologies and low-mass solutions were used for the sensors and deployment systems to allow a fairly complete set of scientific instruments within the 10 kg allocated for the scientific payload. A newly developed wire boom deployment system proved to function excellently. During its seven month lifetime Astrid-2 collected more than 26 Gbytes of high-quality data of auroral electric and magnetic fields, and auroral particle and plasma characteristics from approximately 3000 orbits at an inclination of 83° and an altitude of about 1000 km. Scientific results cover a broad range of topics, from the physics of energization of auroral particles to how the magnetosphere responds to the energy input from the solar wind and global magnetic field modelling. The fulfilment of both the technological and the scientific mission objectives has opened entirely new possibilities to carry out low-budget multipoint measurements in near-Earth space.

    Key words. Ionosphere (auroral ionosphere; instruments and techniques – Magnetospheric physics (auroral phenomena

  13. Astrid-2 and ground-based observations of the auroral bulge in the middle of the nightside convection throat

    Directory of Open Access Journals (Sweden)

    G. T. Marklund

    2001-06-01

    Full Text Available Results concerning the electrodynamics of the nightside auroral bulge are presented based on simultaneous satellite and ground-based observations. The satellite data include Astrid-2 measurements of electric fields, currents and particles from a midnight auroral oval crossing and Polar UVI images of the large-scale auroral distribution. The ground-based observations include STARE and SuperDARN electric fields and magnetic records from the Greenland and MIRACLE magnetometer network, the latter including stations from northern Scandinavia north to Svalbard. At the time of the Astrid-2 crossing the ground-based data reveal intense electrojet activity, both to the east and west of the Astrid-2 trajectory, related to the Polar observations of the auroral bulge but not necessarily to a typical substorm. The energetic electron fluxes measured by Astrid-2 across the auroral oval were generally weak being consistent with a gap observed in the auroral luminosity distribution. The electric field across the oval was directed westward, intensifying close to the poleward boundary followed by a decrease in the polar cap. The combined observations suggests that Astrid-2 was moving close to the separatrix between the dusk and dawn convection cells in a region of low conductivity. The constant westward direction of the electric field across the oval indicates that current continuity was maintained, not by polarisation electric fields (as in a Cowling channel, but solely by localized up- and downward field-aligned currents in good agreement with the Astrid-2 magnetometer data. The absence of a polarisation electric field and thus of an intense westward closure current between the dawn and dusk convection cells is consistent with the relatively weak precipitation and low conductivity in the convection throat. Thus, the Cowling current model is not adequate for describing the electrodynamics of the nightside auroral bulge treated here.Key words. Ionosphere (auroral

  14. EMMA Commissioning

    CERN Document Server

    Muratori, B D; Saveliev, Y M; Smith, S L; Tzenov, S I; Holder, D J; Berg, J S; Keil, E; Johnstone, C; Koscielniak, S R

    2010-01-01

    EMMA (Elec­tron Ma­chine with Many Ap­pli­ca­tions) is a pro­to­type non-scal­ing elec­tron FFAG to be host­ed at Dares­bury Lab­o­ra­to­ry. NS-FFAGs re­lat­ed to EMMA have an un­prece­dent­ed po­ten­tial for med­i­cal ac­cel­er­a­tors for car­bon and pro­ton hadron ther­a­py. It also rep­re­sents a pos­si­ble ac­tive el­e­ment for an ADSR (Ac­cel­er­a­tor Driv­en Sub-crit­i­cal Re­ac­tor). This paper sum­maris­es the com­mis­sion­ing plans for this ma­chine to­geth­er with the major steps and ex­per­i­ments in­volved along the way. A de­scrip­tion of how the 10 to 20 MeV beam is achieved with­in ALICE is also given, as well as ex­trac­tion from the EMMA ring to the di­ag­nos­tics line and then dump.

  15. The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

    Directory of Open Access Journals (Sweden)

    O. Norberg

    2001-06-01

    Full Text Available The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.Key words. Ionosphere (instruments and techniques – Magnetospheric physics (auroral phenomena; instruments and techniques

  16. EMMA: Towards multicultural learning

    Directory of Open Access Journals (Sweden)

    Ruth Kerr

    2016-05-01

    Full Text Available Interest on the part of European Institutions to explore the potential of MOOCs for providing the kind of inclusive and multicultural education that was needed for 21st century learners was confirmed by funding of projects such as EMMA (http://www.europeanmoocs.eu. The definition of “European” for the EMMA consortium was based on diversity - of culture, language and approach - and integration of the same. This paper looks at how EMMA is responding to the challenge of embracing diversity and integration in the same technological artefact through the use of embedded translation services, and an experimental PLE. We will also introduce the ad hoc evaluation services that are designed to test the impact of the EMMA concept.

  17. Fluxgate sensor for the vector magnetometer onboard the ’Astrid-2’ satellite

    DEFF Research Database (Denmark)

    Brauer, Peter; Risbo, T.; Merayo, José M.G.

    2000-01-01

    satellite called 'Orsted'. To obtain good axial stability special attention is drawn to the mechanical construction of the tri-axial sensor configuration. Almost all parts of the sensor are machined from the glassy material MACOR(R) that has approximately the same thermal expansion coefficient as the core...... ribbon. The single axis compensated ringcore sensors are known to have some linearity problems with large uncompensated fields perpendicular to the measuring axis, This phenomenon is also seen for the Astrid-2 sensor, and from a coil-calibration of the flight-spare sensor we observe: non-linearities...

  18. Reading embodied consciousness in "Emma".

    Science.gov (United States)

    Harbus, Antonina

    2011-01-01

    The language of Emma (1815) reflects Jane Austen's developing view of embodied consciousness and her particular interest in this novel in the physical manifestations of emotions, such as blushes and nervous responses. The discursive exploration of the inner life in Emma is the product of a cultural context that features emerging brain science and Austen's own conceptualization of the psychophysical nature of emotions. This article analyzes the language of mind and emotion in Emma, to contend that Austen grapples with the implications of the idea of embodied consciousness in a narrative that contrasts mind reading with interpreting the body.

  19. Emma Goldman: Crusader for Children

    Science.gov (United States)

    Denman, Joy

    1977-01-01

    Author concentrates not on the fiery anarchism for which "Red" Emma Goldman was internationally famous, but on the dilemmas of an anarchist-educator as reflected in her attitude toward children. (Editor/RK)

  20. Comparison of EMMA Parameter Predictions

    CERN Document Server

    Keil, E

    2010-01-01

    This note compares the results for cell tunes, radial offsets at the centre of the long straight section, and time of flight from five programs in the baseline lattice of EMMA, the FFAG electron model under construction at the Daresbury Laboratory. The results are shown in graphs and tables. Both agreements and disagreements between programs are found.

  1. EMMA - gordost Finljandii / Viktoria Panova

    Index Scriptorium Estoniae

    Panova, Viktoria

    2006-01-01

    Soomes Espoos avati uus kaasaegse kunsti muuseum EMMA (Espoo Museum of Modern Art). Põhiekspositsiooni kõrval saab näha nelja ajutist näitust: Kazimir Malevitshi maale, ühenduse "Bubnovõi valet" loomingut, Shirin Neshati foto- ja videoloomingut ning Timo Kelaranta fotokunsti

  2. Emma Goldman: A Study in Female Agitation.

    Science.gov (United States)

    Berry, Elizabeth

    The role of the agitator in society and the special characteristics of women agitators--in particular, Emma Goldman, an American anarchist from the early twentieth century--are discussed in this paper. Specific examples of the rhetoric used by Emma Goldman in her speeches (supporting anarchism, against women's suffrage, against abortion control,…

  3. EMMA: a new paradigm in configurable software

    International Nuclear Information System (INIS)

    Nogiec, J. M.; Trombly-Freytag, K.

    2017-01-01

    EMMA is a framework designed to create a family of configurable software systems, with emphasis on extensibility and flexibility. It is based on a loosely coupled, event driven architecture. The EMMA framework has been built upon the premise of composing software systems from independent components. It opens up opportunities for reuse of components and their functionality and composing them together in many different ways. As a result, it provides the developer of test and measurement applications with a lightweight alternative to microservices, while sharing their various advantages, including composability, loose coupling, encapsulation, and reuse.

  4. EMMA: a new paradigm in configurable software

    Science.gov (United States)

    Nogiec, J. M.; Trombly-Freytag, K.

    2017-10-01

    EMMA is a framework designed to create a family of configurable software systems, with emphasis on extensibility and flexibility. It is based on a loosely coupled, event driven architecture. The EMMA framework has been built upon the premise of composing software systems from independent components. It opens up opportunities for reuse of components and their functionality and composing them together in many different ways. It provides the developer of test and measurement applications with a lightweight alternative to microservices, while sharing their various advantages, including composability, loose coupling, encapsulation, and reuse.

  5. EAS selection in the EMMA underground array

    DEFF Research Database (Denmark)

    Sarkamo, J.; Bezrukov, L.; Enqvist, T.

    2013-01-01

    The first measurements of the Experiment with MultiMuon Array (EMMA) have been analyzed for the selection of the Extensive Air Showers (EAS). Test data were recorded with an underground muon tracking station and a satellite station separated laterally by 10 metres. Events with tracks distributed...

  6. Teaching the 'A' Level Text: Emma.

    Science.gov (United States)

    Huband, David

    1987-01-01

    Notes how important it is that any critical writing assignments should take into account the individual reading, and that the teacher's role is to steer discussion that stems from a class of individual readings. Explores some of the aspects of Jane Austen's novel "Emma" to which students readily respond. (HTH)

  7. Learning analytics approach of EMMA project

    NARCIS (Netherlands)

    Tammets, Kairit; Brouns, Francis

    2014-01-01

    The EMMA project provides a MOOC platform to aggregate and delivers massive open online courses (MOOC) in multiple languages from a variety of European universities. Learning analytics play an important role in MOOCs to support the individual needs of the learner.

  8. Underground cosmic-ray experiment EMMA

    DEFF Research Database (Denmark)

    Kuusiniemi, P.; Bezrukov, L.; Enqvist, T.

    2013-01-01

    EMMA (Experiment with MultiMuon Array) is a new approach to study the composition of cosmic rays at the knee region (1 – 10 PeV). The array will measure the multiplicity and lateral distribution of the high-energy muon component of an air shower and its arrival direction on an event-by-event basis...

  9. Visuaalisen ilmeen suunnittelu / Make Up Emma Puhakka

    OpenAIRE

    Puhakka, Roosa

    2017-01-01

    Opinnäytetyössä luon visuaalisen ilmeen meikkitaiteilija Emma Puhakalle. Työni taustaksi olen keskittynyt brändäykseen, brändi-ilmeen luomiseen, henkilöbrändäykseen sekä pohtinut myös brändistrategiaa. Suunnittelutyössä toteutan visuaalisen ilmeen asiakkaalleni ja mallinnan uuden ilmeen jalkautumisen eri materiaaleihin. Suunnittelen mm. logon, yrityksen värimaailman, kuosin ja määrittelen typografian. Opinnäytetyöni lopputulos on brändimanuaali, joka pitää sisällään visuaalisen ilmeen...

  10. The EMMA Non-scaling FFAG

    CERN Document Server

    Edgecock, Thomas; Clarke, James; Griffiths, Stephen; Hill, Clive; Jamison, Steven; Jones, James; Kalinin, Alexander; Marinov, Kiril; Marks, Neil; McIntosh, Peter; Muratori, Bruno; Orrett, Joseph; Saveliev, Yuri; Shepherd, Ben; Smith, Robert; Smith, Susan; Tzenov, Stephan; Wheelhouse, Alan; Berg, J. Scott; Bliss, Neil; Martlew, Brian; White, Christopher; Craddock, Michael; Crisp, James; Johnstone, Carol; Giboudot, Yoel; Keil, Eberhard; Kelliher, David; Machida, Shinji; Koscielniak, Shane; Meot, Francois; Pasternak, Jaroslaw; Sheehy, Suzanne; Yokoi, Takeichiro

    2010-01-01

    The Elec­tron Model for Many Ap­pli­ca­tions (EMMA) will be the World's first non-scal­ing FFAG and is under con­struc­tion at the STFC Dares­bury Lab­o­ra­to­ry in the UK. Con­struc­tion is due for com­ple­tion in March 2010 and will be fol­lowed by com­mis­sion­ing with beam and a de­tailed ex­per­i­men­tal pro­gramme to study the func­tion­ing of this type of ac­cel­er­a­tor. This paper will give an overview of the mo­ti­va­tion for the pro­ject and de­scribe the EMMA de­sign and hard­ware. The first re­sults from com­mis­sion­ing will be pre­sent­ed in a sep­a­rate paper.

  11. Neutron generator power supply modeling in EMMA

    International Nuclear Information System (INIS)

    Robinson, A.C.; Farnsworth, A.V.; Montgomery, S.T.; Peery, J.S.; Merewether, K.O.

    1996-01-01

    Sandia National Laboratories has prime responsibility for neutron generator design and manufacturing, and is committed to developing predictive tools for modeling neutron generator performance. An important aspect of understanding component performance is explosively driven ferroelectric power supply modeling. EMMA (ElectroMechanical Modeling in ALEGRA) is a three dimensional compile time version of Sandia's ALEGRA code. The code is built on top of the general ALEGRA framework for parallel shock-physics computations but also includes additional capability for modeling the electric potential field in dielectrics. The overall package includes shock propagation due to explosive detonation, depoling of ferroelectric ceramics, electric field calculation and coupling with a general lumped element circuit equation system. The AZTEC parallel iterative solver is used to solve for the electric potential. The DASPK differential algebraic equation package is used to solve the circuit equation system. Sample calculations are described

  12. EmmA, An Evolution Memory Management Assistant

    National Research Council Canada - National Science Library

    McCullough, Daryl

    2000-01-01

    .... EMMA differs from current project management tools in that it manages not only the system requirements that developers must satisfy, but also the context in which the developers develop the system...

  13. EMMA The World's First Non-scaling FFAG

    CERN Document Server

    Edgecock, R; Machida, S; Beard, C; Bliss, N; Clarke, J; Hill, C; Jamison, S; Kalinin, A; Marinov, K; Marks, N; Martlew, B; McIntosh, P; Muratori, B; Owen, H; Saveliev, Yu; Shepherd, B; Smith, R; Smith, S; Tzenov, S; White, C; Wooldridge, E; Berg, J S; Trbojevic, D; Craddock, M; Koscielniak, S; Crisp, J; Johnstone, C; Giboudot, Y; Keil, E; Méot, F; Yokoi, T

    2008-01-01

    EMMA – the Electron Model of Many Applications – is to be built at the STFC Daresbury Laboratory in the UK and will be the first non-scaling FFAG ever constructed. EMMA will be used to demonstrate the principle of this type of accelerator and study its features in detail. The design of the machine and its hardware components are now far advanced and construction is due for completion in Autumn 2009.

  14. EMMA-The world's first non-scaling FFAG

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, R [Cockcroft Institute of Accelerator Science and Technology, Daresbury, Warrington, WA4 4AD (United Kingdom); Manchester University, Manchester, M13 9PL (United Kingdom); Berg, J.S. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Beard, C. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Bliss, N.; Clarke, J. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Craddock, M.K. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Crisp, J. [Fermi National Accelerator Laboratory, Batavia, IL 60510-5011 (United States); Edgecock, R., E-mail: rob.edgecock@stfc.ac.u [STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX (United Kingdom); Giboudot, Y. [Brunel University, Uxbridge, Middlesex, UB8 3PH (United Kingdom); Goudket, P.; Griffiths, S.; Hill, C.; Jamison, S. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Johnstone, C. [Fermi National Accelerator Laboratory, Batavia, IL 60510-5011 (United States); Kalinin, A. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Keil, E. [CERN, Geneva, CH-1211 (Switzerland); Kelliher, D. [STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX (United Kingdom); Koscielniak, S. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Machida, S. [STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX (United Kingdom); Marinov, K. [STFC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom)

    2010-12-01

    Due to the combination of fixed magnetic field operation with strong focusing, non-scaling FFAGs have a significant potential for future particle accelerator applications. However, this technology has a number of unique features, which must be fully studied before this potential can be realised. To do this, a proof-of-principle non-scaling FFAG, called EMMA - Electron Model for Many Applications - has been constructed at the STFC Daresbury Laboratory in the UK. It has been designed by an international collaboration of accelerator scientists and engineers. It will demonstrate the principle of non-scaling FFAGs and be used to study the features of this type of accelerator in detail.

  15. Dense ion clouds of 0.1 − 2 keV ions inside the CPS-region observed by Astrid-2

    Directory of Open Access Journals (Sweden)

    O. Norberg

    Full Text Available Data from the Astrid-2 satellite taken between April and July 1999 show several examples of dense ion clouds in the 0.1–2 keV energy range inside the inner mag-netosphere, both in the northern and southern hemispheres. These inner magnetospheric ion clouds are found predomi-nantly in the early morning sector, suggesting that they could have originated from substorm-related ion injections on the night side. However, their location and density show no cor-relation with Kp, and their energy-latitude dispersion is not easily reproduced by a simple particle drift model. There-fore, these ion clouds are not necessarily caused by substorm-related ion injections. Alternative explanations for the ion clouds are the direct solar wind injections and up-welling ions from the other hemisphere. These explanations do not, however, account for all of the observations.Key words. Magnetospheric physics (energetic particles, trapped; magnetospheric configuration and dynamics; storm and substorms

  16. Nonlinear kinematics for piezoelectricity in ALEGRA-EMMA.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, John Anthony; Fuller, Timothy Jesse

    2013-09-01

    This report develops and documents nonlinear kinematic relations needed to implement piezoelectric constitutive models in ALEGRA-EMMA [5], where calculations involving large displacements and rotations are routine. Kinematic relationships are established using Gausss law and Faradays law; this presentation on kinematics goes beyond piezoelectric materials and is applicable to all dielectric materials. The report then turns to practical details of implementing piezoelectric models in an application code where material principal axes are rarely aligned with user defined problem coordinate axes. This portion of the report is somewhat pedagogical but is necessary in order to establish documentation for the piezoelectric implementation in ALEGRA-EMMA. This involves transforming elastic, piezoelectric, and permittivity moduli from material principal axes to problem coordinate axes. The report concludes with an overview of the piezoelectric implementation in ALEGRA-EMMA and small verification examples.

  17. Garri Potter povzroslel! / Daniel Radcliffe, Emma Watson ; interv. Stass Tõrkin

    Index Scriptorium Estoniae

    Radcliffe, Daniel, 1989-

    2005-01-01

    Peaosatäitja järjekorras neljandas Potteri ekraniseeringus "Harry Potter ja tulepeeker" endast, oma tegelaskuju arengust. Samas ka lühiintervjuu näitlejanna Emma Watsoniga. Režissöör Mike Newell : Suurbritannia-USA 2005

  18. Bootcamp EMMA MOOC Assessment for learning in practice

    NARCIS (Netherlands)

    Firssova, Olga; Brouns, Francis

    2016-01-01

    At the EDEN Conference an introduction to the EMMA platform will be combined with learning activities relevant to the topic of Formative Assessment. EDEN conference participants will have an opportunity to join the MOOC prior to the conference or at the conference. A range of learning activities

  19. A different voice: Mary Hays's the Memoirs of Emma Courtney.

    Science.gov (United States)

    Sharma, A

    2001-01-01

    Mary Hays wrote in the decade of the 1790s, a period of intense creative flowering in England. Writing in a period enshrined to the works of the canonical Wordsworth and Coleridge, Hays explored through her Jacobinical novel, The Memoirs of Emma Courtney, the contentious relationship between self and society. Like other Jacobin women writers - Elizabeth Inchbald, Charlotte Smith and Mary Wollstonecraft - Mary Hays too used her novel to explode the insidious connection between education and gender construction. Emma Courtney is a landmark novel that wrestles with the paradigm of decorum and propriety which disallows women from voicing their aspirations. In the process, Hays merges the plots of the domestic novel of courtship and love with the novel of ideas to create a searing portrait of women's intellectual confinement and psychic dissonance in a society that only projects them in terms of their gender construction. Memoirs of Emma Courtney is a remarkable novel in its depiction of the emotional imbalance created by thwarted desire: intellectual and sexual.

  20. Positiivne ränne Baltimaade kunstielus / Emma Duester ; intervjueerinud Laura Põld

    Index Scriptorium Estoniae

    Duester, Emma

    2015-01-01

    Emma Duesteri dissertatsioonist, mille raames uuriti Tallinna, Riia ja Vilniuse päritolu kunstnike sisserännet Suurbritanniasse. Mobiilsusest immigratsiooniküsimuse kontekstis, kunstielust Baltimaades

  1. Emma Zunz by Jorge Luis Borges: the Concept of Justice

    OpenAIRE

    Rosa Vila

    2014-01-01

    Emma Zunz, by Jorge Luis Borges, is the story of a girl who decides to kill her boss in order to avenge her father’s death, believing that her father’s version of an event that occurred years before was true. Thus, she devises a secret plan, which includes losing her virginity to a complete stranger, shortly before committing the crime, so she could argue that her boss had raped her and that she killed him in self-defense. Firstly, the text shows the contrast between formal justic...

  2. Microstorie magistrali: Emma Tettoni fra carduccianesimo e reti emancipative

    Directory of Open Access Journals (Sweden)

    Loredana Magazzeni

    2015-12-01

    Full Text Available Emma Tettoni (Novara, 1859 – Bergamo, 1891 was a teacher in secondary schools for women, headmistress of the Scuola normale femminile in Rovigo (Italy, student of Giosuè Carducci at Bologna University (1879-1881 and classmate of Giovanni Pascoli and Giulia Cavallari Cantalamessa. She devoted her life to teaching and writing, considering them prerequisites for female emancipation. Moving from her correspondence with the great Italian poet - teacher, but also from her female friendship network, it is possible to trace the phases of her arduous life as social and professional engaged young woman. Because of the novelty of her ideas, expressed in education lectures (on love, women’s work, women scientists and the faults of Italian mothers, she suffered the painful ostracism of conservative factions. In 1890 she joined the organization of VI Centenary of Beatrice Portinari, in Florence.

  3. EPA data for EMMA of Peatland Discharge to an Alaskan Stream Journal of Hydrology 2015

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains primarily the EPA generated data for the EMMA (End-Member-Mixing Analysis) model that was presented in the associated J. of Hydrology (2015)...

  4. Analysis on the Tragedy Figure of Gustave Flaubert——Emma in Madam Bovary

    Institute of Scientific and Technical Information of China (English)

    申辰瑜

    2015-01-01

    Emma is considered to be the most successful character created by Flaubert,though arouse fierce criticize at the time of her first debut. Finally,the novel receives the due respect and attention and Emma,becomes the center of the discussion of numerous readers and critics. In this paper,I would like to provide my analysis of Madam Bovary,focusing on the tragic traits of this character and attempt to fi nd the answers.

  5. Emma Zunz by Jorge Luis Borges: the Concept of Justice

    Directory of Open Access Journals (Sweden)

    Rosa Vila

    2014-12-01

    Full Text Available Emma Zunz, by Jorge Luis Borges, is the story of a girl who decides to kill her boss in order to avenge her father’s death, believing that her father’s version of an event that occurred years before was true. Thus, she devises a secret plan, which includes losing her virginity to a complete stranger, shortly before committing the crime, so she could argue that her boss had raped her and that she killed him in self-defense. Firstly, the text shows the contrast between formal justice and taking justice into own hands. Secondly, the question of self-inflicted punishment, which in the story takes place before the perpetration of the crime. Finally, the issue whether truth is the version that can be inferred from the evidence presented in a trial, or the one which is kept to themselves by those involved in a crime. Emma Zunz, de Jorge Luis Borges, es la historia de una chica que decide matar a su jefe para vengar la muerte de su padre, creyendo que la versión de su padre de un hecho que ocurrió años atrás era cierta. De este modo, diseña un plan secreto, que incluye la pérdida de su virginidad con un desconocido, poco antes de cometer el crimen, para poder argumentar que su jefe la había violado y que ella lo mató en defensa propia. En primer lugar, el texto muestra el contraste entre la justicia formal y la justicia por cuenta propia. En segundo lugar, la cuestión de la pena infligida a uno mismo, lo que en la historia se produce antes de la comisión del delito. Por último, la cuestión de si la verdad es la versión que se puede inferir de las pruebas presentadas en un juicio, o la que se guardan para sí mismas las personas involucradas en un crimen. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=2519490

  6. EMMA: A new underground cosmic-ray experiment

    International Nuclear Information System (INIS)

    Enqvist, T; Foehr, V; Joutsenvaara, J; Jaemsen, T; Keraenen, P; Kuusiniemi, P; Laitala, H; Lehtola, M; Mattila, A; Narkilahti, J; Peltoniemi, J; Remes, H; Reponen, M; Raeihae, T; Sarkamo, J; Shen, C; Vaittinen, M; Zhang, Z; Ding, L; Zhu, Q; Roos, M; Dzaparova, I; Karpov, S; Kurenya, A; Petkov, V; Yanin, A; Fynbo, H

    2006-01-01

    A cosmic-ray experiment of new type is under construction in the Pyhaesalmi mine in the underground laboratory of the University of Oulu, Finland. It aims to study the composition of cosmic rays at and above the knee region (energy above 1 PeV). The experiment, called EMMA, covers about 150 m 2 of detector area, and the setup is capable of measuring the multiplicity and the lateral distribution of underground muons, and the arrival direction of the air shower. The detector is placed at the depth of about 85 metres (corresponding about 240 mwe) which gives a threshold energy of muons of about 45 GeV. The rock overburden filters out all other particles of the air shower except the high-energy muons. These high-energy muons originate at high altitudes close to the first interaction of the primary cosmic ray and they carry more information about the primary than low-energy muons. The full-size detector is supposed to run by the end of 2007

  7. Withstanding trauma: the significance of Emma Eckstein's circumcision to Freud's Irma dream.

    Science.gov (United States)

    Bonomi, Carlo

    2013-07-01

    The author considers the medical rationale for Wilhelm Fliess's operation on Emma Eckstein's nose in February 1895 and interprets the possible role that this played in Freud's dream of Irma's injection five months later. The author's main argument is that Emma likely endured female castration as a child and that she therefore experienced the surgery to her nose in 1895 as a retraumatization of her childhood trauma. The author further argues that Freud's unconscious identification with Emma, which broke through in his dream of Irma's injection with resistances and apotropaic defenses, served to accentuate his own "masculine protest". The understanding brought to light by the present interpretation of Freud's Irma dream, when coupled with our previous knowledge of Freud, allows us to better grasp the unconscious logic and origins of psychoanalysis itself.(1.) © 2013 The Psychoanalytic Quarterly, Inc.

  8. CHARACTERISATION OF THE ALICE ACCELERATOR AS AN INJECTOR FOR THE EMMA NS-FFAG

    CERN Document Server

    Garland, J M; McKenzie, J W; Muratori, B D

    2010-01-01

    EMMA (ElectronModel with Many Applications) is the first proof-of-principle non-scaling FFAG accelerator and is presently under construction at Daresbury Laboratory in the UK. To probe different parts of the bunch phase space during the acceleration from 10 to 20 MeV (which requires rapid resonance crossing), electron bunches are needed with sufficiently small emittance. To understand the phase space painting into the 3000 mm-mrad EMMA acceptance, we have modelled ALICE (Accelerators and Lasers in Combined Experiments) - which acts as an injector for EMMA - using GPT and compared the estimated emittances with measurements made with a variety of screen-based methods. Although the emittances are not yet as small as desired, we obtain reasonable agreement between simulation and measurement.

  9. An Adaptive Display to Treat Stress-Related Disorders: EMMA's World

    Science.gov (United States)

    Banos, R. M.; Botella, C.; Guillen, V.; Garcia-Palacios, A.; Quero, S.; Breton-Lopez, J.; Alcaniz, M.

    2009-01-01

    Most of the virtual environments currently available in the field of psychological treatments were designed to solve a specific problem. Our research group has developed a versatile virtual reality system (an adaptive display) called "EMMA's world", which can address a wide range of problems. It was designed to assist in clinical situations where…

  10. Two Case Histories, Ishbel Ross and Emma Bugbee: Women Journalists Ride the Rail with the Suffragettes.

    Science.gov (United States)

    Merrick, Beverly G.

    The rise to prominence of the women's suffrage movement in the World War I years brought women reporters into U.S. newsrooms for the first time. In 1911 Emma Bugbee became the first woman hired as a "hard" news reporter for the "New York Tribune" (later the "Herald Tribune"). Ishbel Ross, author of "Ladies of the…

  11. Amando de olhos abertos: Emma Goldman e o dissenso político nos EUA Loving with open eyes: Emma Goldman and the political dissent in the Unites States

    Directory of Open Access Journals (Sweden)

    Cecilia Azevedo

    2007-12-01

    Full Text Available Este artigo apresenta a trajetória de Emma Goldman, grande nome do anarquismo, pacifismo e feminismo nos EUA, procurando apresentá- la como uma representante da chamada tradição de dissenso neste país que, ao longo de toda sua história, tem disputado os sentidos a serem atribuídos aos ideais nacionais. Em meio à atual guerra no Iraque, a memória e o legado de Emma Goldman vêm sendo recuperados no embate político em torno do sentido do americanismo.This article presents the life of Emma Goldman, who played a central role in the history of anarchism, pacifism and feminism in the United States. In the present days, when a new war is taking place in Iraq, the memory and legacy of Emma Goldman are being reassessed amidst the debate over the political meaning of Americanism.

  12. Bravo Emma! Music in the life and work of Charles Darwin.

    Science.gov (United States)

    Derry, J F

    2009-03-01

    The long-term marital dance of Emma and Charles Darwin was set to the routine beat of an almost daily piano recital. Emma was a proficient pianist, and so a quality instrument was a welcome and appropriate house-warming present for their first marital home in London. That same piano accompanied the Darwins on their move to Downe before being upgraded for a newer model, which is still there, whilst another, cheaper piano may have played in Charles Darwin's work, particularly on earthworms. Whilst he lamented his own lack of musicality, Darwin revelled in his wife's prowess, a capacity that he recognised could be inherited, not least through observation of his own children. The evolution of musicality, he reasoned, was rooted in sexual attraction as a form of communication that preceded language.

  13. Revised age of deglaciation of Lake Emma based on new radiocarbon and macrofossil analyses

    Science.gov (United States)

    Elias, S.A.; Carrara, P.E.; Toolin, L.J.; Jull, A.J.T.

    1991-01-01

    Previous radiocarbon ages of detrital moss fragments in basal organic sediments of Lake Emma indicated that extensive deglaciation of the San Juan Mountains occurred prior to 14,900 yr B.P. (Carrara et al., 1984). Paleoecological analyses of insect and plant macrofossils from these basal sediments cast doubt on the reliability of the radiocarbon ages. Subsequent accelerator radiocarbon dates of insect fossils and wood fragments indicate an early Holocene age, rather than a late Pleistocene age, for the basal sediments of Lake Emma. These new radiocarbon ages suggest that by at least 10,000 yr B.P. deglaciation of the San Juan Mountains was complete. The insect and plant macrofossils from the basal organic sediments indicate a higher-than-present treeline during the early Holocene. The insect assemblages consisted of about 30% bark beetles, which contrasts markedly with the composition of insects from modern lake sediments and modern specimens collected in the Lake Emma cirque, in which bark beetles comprise only about 3% of the assemblages. In addition, in the fossil assemblages there were a number of flightless insect species (not subject to upslope transport by wind) indicative of coniferous forest environments. These insects were likewise absent in the modern assemblage. ?? 1991.

  14. iPhone, Android, or Kindle: The Emma S. Clark Memorial Library Has an App for That and So Can You

    Science.gov (United States)

    Johnson, Bob; Gutmann, Ted

    2013-01-01

    If you are like the millions of people buying the latest smartphone, iPhone 5, or Samsung Galaxy S III, your local library should have something to offer you. The Emma S. Clark Memorial Library, for one, has an app for that! Dubbed "Emma Mobile," the library's application works with iOS (Apple), Android (Google), and Amazon Kindle Fire…

  15. Mikropropagasi Dendrobium “Emma Pink” (Orchidaceae pada Media Kultur In Vitro

    Directory of Open Access Journals (Sweden)

    ASTRI NUGROHO

    2006-05-01

    Full Text Available An experiment of micropropagation of the orchid Dendrobium “Emma Pink” on the media Vacin and Went using tissue culture technique has been done. The explant was obtained from the young stem of Dendrobium “Emma Pink”. Induction stage was started by culturing the first, second, third, fourth axilar buds counted from the base of the stem and apical bud. The most potential bud to be used as a source for an explant was identified from the serial culturing of explant on the liquid media with various combinations of growth regulator kinetin and IAA. The media were placed on a shaker at 90 rpm. The second and the third axilar buds were the most potential sources of explant at 10-5 M kinetin and 5.10-7 M IAA, with the degree of success for the formation of protocorm like bodies (protocorm- like bodies were 56.25% and 43.75% respectively. The formation and multiplication of buds were obtained from protocorm-like bodies which were cultured in the solid media in the addition of 10-4 M kinetin and 5.10-6M IAA. The multiplication rate of the buds has continuously increased during the subcultures with an average multiplication rate of 3.25 buds/4 weeks, 4.59 buds/4 weeks, 6.32 buds/4 weeks and 8.80 buds/4 weeks respectively. The roots were formed when the buds were cultured in the solid media by adding 5.10-6 M kinetin and M IAA. The degree of acclimatization success of Dendrobium “Emma Pink” was 93.33% for the rooted bud and 53.33% for the unrooted bud.

  16. MODELLING OF THE EMMA NS-FFAG INJECTION LINE USING GPT

    CERN Document Server

    D’Arcy, R T P; Muratori, B D; Jones, J

    2010-01-01

    EMMA (Elec­tron Ma­chine with Many Ap­pli­ca­tions) is a pro­to­type non-scal­ing Fixed Field Al­ter­nat­ing Gra­di­ent (NS-FFAG) ac­cel­er­a­tor present­ly under con­struc­tion at Dares­bury Lab­o­ra­to­ry, UK. The en­er­gy re­cov­ery linac ALICE will serve as an in­jec­tor for EMMA with­in the en­er­gy range of 10 to 20 MeV. The in­jec­tion line con­sists of a sym­met­ric 30° dog­leg to ex­tract the beam from ALICE, a match­ing sec­tion and a to­mog­ra­phy sec­tion for trans­verse emit­tance mea­sure­ments. This is fol­lowed by a trans­port sec­tion to the in­jec­tion point of the EMMA ring. Com­mis­sion­ing of the EMMA in­jec­tion line start­ed in early 2010. A num­ber of dif­fer­ent in­jec­tion en­er­gy and bunch charge regimes are planned; for some of the regimes the ef­fects of space charge will be sig­nif­i­cant. It is there­fore nec­es­sary to model the elec­tron beam trans­port in this line using a code ca­pa­ble of both...

  17. "I am a trained nurse": the nursing identity of anarchist and radical Emma Goldman.

    Science.gov (United States)

    Connolly, Cynthia Anne

    2010-01-01

    For more than a century, scholars have analyzed the many dimensions of Emma Goldman. Remembered as an agent of revolution, feminism, sexual freedom, anarchy, and atheism, Goldman's motives, personality, and actions have generated an entire subgenre of historical scholarship. But although Goldman practiced nursing in New York City for ten years, one facet of her life that has been neglected is her nursing identity. Goldman's autobiography, Living My Life, reveals the way her nursing experiences informed her evolving anarchist political philosophy and international activism. She valued nursing for many reasons--for the economic independence it offered, identity it provided, and sense of community and connectivity she believed it encouraged. Finally, for Goldman, nursing represented was a vehicle to understand people's struggles and as a way of translating political philosophy into meaningful, practical solutions.

  18. "EMMA Study: a Brazilian community-based cohort study of stroke mortality and morbidity"

    Directory of Open Access Journals (Sweden)

    Alessandra Carvalho Goulart

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Stroke has a high burden of disability and mortality. The aim here was to evaluate epidemiology, risk factors and prognosis for stroke in the EMMA Study (Study of Stroke Mortality and Morbidity. DESIGN AND SETTINGS: Prospective community-based cohort carried out in Hospital Universitário, University of São Paulo, 2006-2014. METHODS: Stroke data based on fatal and non-fatal events were assessed, including sociodemographic data, mortality and predictors, which were evaluated by means of logistic regression and survival analyses. RESULTS: Stroke subtype was better defined in the hospital setting than in the local community. In the hospital phase, around 70% were first events and the ischemic subtype. Among cerebrovascular risk factors, the frequency of alcohol intake was higher in hemorrhagic stroke (HS than in ischemic stroke (IS cases (35.4% versus 12.3%, P < 0.001. Low education was associated with higher risk of death, particularly after six months among IS cases (odds ratio, OR, 4.31; 95% confidence interval, CI, 1.34-13.91. The risk of death due to hemorrhagic stroke was greater than for ischemic stroke and reached its maximum 10 days after the event (OR: 3.31; 95% CI: 1.55-7.05. Four-year survival analysis on 665 cases of first stroke (82.6% ischemic and 17.4% hemorrhagic showed an overall survival rate of 48%. At four years, the highest risks of death were in relation to ischemic stroke and illiteracy (hazard ratio, HR: 1.83; 95% CI: 1.26-2.68 and diabetes (HR: 1.45; 95% CI: 1.07-1.97. Major depression presented worse one-year survival (HR: 4.60; 95% CI: 1.36-15.55. CONCLUSION: Over the long term, the EMMA database will provide additional information for planning resources destined for the public healthcare system.

  19. "EMMA Study: a Brazilian community-based cohort study of stroke mortality and morbidity".

    Science.gov (United States)

    Goulart, Alessandra Carvalho

    2016-01-01

    Stroke has a high burden of disability and mortality. The aim here was to evaluate epidemiology, risk factors and prognosis for stroke in the EMMA Study (Study of Stroke Mortality and Morbidity). Prospective community-based cohort carried out in Hospital Universitário, University of São Paulo, 2006-2014. Stroke data based on fatal and non-fatal events were assessed, including sociodemographic data, mortality and predictors, which were evaluated by means of logistic regression and survival analyses. Stroke subtype was better defined in the hospital setting than in the local community. In the hospital phase, around 70% were first events and the ischemic subtype. Among cerebrovascular risk factors, the frequency of alcohol intake was higher in hemorrhagic stroke (HS) than in ischemic stroke (IS) cases (35.4% versus 12.3%, P hemorrhagic stroke was greater than for ischemic stroke and reached its maximum 10 days after the event (OR: 3.31; 95% CI: 1.55-7.05). Four-year survival analysis on 665 cases of first stroke (82.6% ischemic and 17.4% hemorrhagic) showed an overall survival rate of 48%. At four years, the highest risks of death were in relation to ischemic stroke and illiteracy (hazard ratio, HR: 1.83; 95% CI: 1.26-2.68) and diabetes (HR: 1.45; 95% CI: 1.07-1.97). Major depression presented worse one-year survival (HR: 4.60; 95% CI: 1.36-15.55). Over the long term, the EMMA database will provide additional information for planning resources destined for the public healthcare system.

  20. EMMA: An Extensible Mammalian Modular Assembly Toolkit for the Rapid Design and Production of Diverse Expression Vectors.

    Science.gov (United States)

    Martella, Andrea; Matjusaitis, Mantas; Auxillos, Jamie; Pollard, Steven M; Cai, Yizhi

    2017-07-21

    Mammalian plasmid expression vectors are critical reagents underpinning many facets of research across biology, biomedical research, and the biotechnology industry. Traditional cloning methods often require laborious manual design and assembly of plasmids using tailored sequential cloning steps. This process can be protracted, complicated, expensive, and error-prone. New tools and strategies that facilitate the efficient design and production of bespoke vectors would help relieve a current bottleneck for researchers. To address this, we have developed an extensible mammalian modular assembly kit (EMMA). This enables rapid and efficient modular assembly of mammalian expression vectors in a one-tube, one-step golden-gate cloning reaction, using a standardized library of compatible genetic parts. The high modularity, flexibility, and extensibility of EMMA provide a simple method for the production of functionally diverse mammalian expression vectors. We demonstrate the value of this toolkit by constructing and validating a range of representative vectors, such as transient and stable expression vectors (transposon based vectors), targeting vectors, inducible systems, polycistronic expression cassettes, fusion proteins, and fluorescent reporters. The method also supports simple assembly combinatorial libraries and hierarchical assembly for production of larger multigenetic cargos. In summary, EMMA is compatible with automated production, and novel genetic parts can be easily incorporated, providing new opportunities for mammalian synthetic biology.

  1. The English Village in Emma: An Empirical Study of Heritage Dramas, Location Filming and Host Communities

    Directory of Open Access Journals (Sweden)

    Lavinia Brydon

    2017-07-01

    Full Text Available This article considers location filming for heritage dramas in rural England, focusing on the experiences of the communities that “host” television crews during production. The article specifically examines the filming of the 2009 BBC adaptation of Jane Austen’s Emma, for which the historic Kent village, Chilham, doubled as the fictional Highbury. In doing so, it interrogates two central aspects. First, it illuminates some of the practical issues and economic and cultural impact of location filming for heritage dramas within rural areas. Second, it reflects upon how a community experiences and responds to its status as the host of such a series, considering the impact this has upon questions of identity and heritage. The article draws upon original empirical research, oral history interviews and community archive building conducted within the Chilham community and with Kent Film Office. It explores the memories and experiences of the local population involved in the television location filming process, as both spectators and participants. We thus consider the significance of location from the point of view of those who solicit, resist, profit from, and are caused problems by the temporary transformation of their local space into a television drama shooting space, forging new connections between production practices, location shooting and heritage series and national television/cinema.

  2. Diagnostic System Commissioning of the EMMA NS-FFAG Facility at Daresbury Laboratory

    CERN Document Server

    Kalinin, A

    2010-01-01

    We pre­sent pre­lim­i­nary re­sults of beam di­ag­nos­tics for the world's first Non-Scal­ing FFAG Ac­cel­er­a­tor 'EMMA'. Amongst other means, a sin­gle-shot/turn-by-turn BPM sys­tem is used, that was first test­ed on the ALICE in­jec­tor. The BPM sys­tem uti­lizes a front-end con­ver­sion of but­ton pick­up sig­nals into flat-top-en­ve­lope 700 MHz bursts, time-do­main mul­ti­plex­ing (in each plane, sig­nals are made spaced by 13.8 ns), and the man­u­fac­ture of both syn­chronous de­tec­tor and ADC clocks di­rect­ly from the beam sig­nal. The sys­tem per­for­mance is dis­cussed; re­sults of beam-based res­o­lu­tion mea­sure­ment are given. First turn beam tra­jec­to­ries fur­thest from the Sep­tum and Kick­er are pre­sent­ed.

  3. Characterization of the Complete Mitochondrion Genome of Diurnal Moth Amata emma (Butler) (Lepidoptera: Erebidae) and Its Phylogenetic Implications

    Science.gov (United States)

    Lu, Hui-Fen; Su, Tian-Juan; Luo, A-Rong; Zhu, Chao-Dong; Wu, Chun-Sheng

    2013-01-01

    Mitogenomes can provide information for phylogenetic analyses and evolutionary biology. The complete mitochondrial genome of Amata emma (Lepidoptera: Erebidae) was sequenced and analyzed in the study. The circular genome is 15,463 bp in size, with the gene content, orientation and order identical to other ditrysian insects. The genome composition of the major strand shows highly A+T biased and exhibits negative AT-skew and GC-skew. The initial codons are the canonical putative start codons ATN with the exception of cox1 gene which uses CGA instead. Ten genes share complete termination codons TAA, and three genes use incomplete stop codons TA or T. Additionally, the codon distribution and Relative Synonymous Codon Usage of the 13 PCGs in the A. emma mitogenome are consistent with those in other Noctuid mitogenomes. All tRNA genes have typical cloverleaf secondary structures, except for the trnS1 (AGN) gene, in which the dihydrouridine (DHU) arm is simplified down to a loop. The secondary structures of two rRNA genes broadly conform with the models proposed for these genes of other Lepidopteran insects. Except for the A+T-rich region, there are three major intergenic spacers, spanning at least 10 bp and five overlapping regions. There are obvious differences in the A+T-rich region between A. emma and other Lepidopteran insects reported previously except that the A+T-rich region contains an ‘ATAGA’ -like motif followed by a 19 bp poly-T stretch and a (AT)9 element preceded by the ‘ATTTA’ motif. It neither has a poly-A (in the α strand) upstream trnM nor potential stem-loop structures and just has some simple structures like (AT)nGTAT. The phylogenetic relationships based on nucleotide sequences of 13 PCGs using Bayesian inference and maximum likelihood methods provided a well-supported a broader outline of Lepidoptera and which agree with the traditional morphological classification and recently working, but with a much higher support. PMID:24069145

  4. Cronotopos y autobiografía epistolar como mecanismos de autorreflexión en Memoria por correspondencia, de Emma Reyes

    OpenAIRE

    Trujillo Henao, Isabel Cristina

    2015-01-01

    En el libro Memoria por correspondencia (2012), la artista plástica Emma Reyes, cuenta una historia que inicia en sus primeros recuerdos y que va hasta sus 20 años, usando el género de la autobiografía epistolar -- Este análisis busca, tomando como base la teoría de cronotopos de Mijail Bajtin y del mismo género literario, encontrar y describir los diversos elementos que ayudan a dar cuenta del proceso de autorreflexión experimentado por la autora -- Así, se hallarán y describirán las herrami...

  5. D11.3.1: Results from the operation of EMMA using the new diagnostics

    CERN Document Server

    Machida, S

    2012-01-01

    In a Fixed-Field, Alternating-Gradient (FFAG) accelerator, eliminating pulsed magnet operation permits rapid acceleration to synchrotron energies, but with a much higher beam-pulse repetition rate. Conceived in the 1950s, FFAGs are enjoying renewed interest, fuelled by the need to rapidly accelerate unstable muons for future high energy physics colliders. Until now a ‘scaling’ principle has been applied to avoid beam blow-up and loss. Removing this restriction produces a new breed of FFAG, a non-scaling variant, allowing powerful advances in machine characteristics. We report on the first non-scaling FFAG, in which orbits are compacted to within 10 mm in radius over an electron momentum range of 12 to 18 MeV/c. In this strictly linear-gradient FFAG, unstable beam regions are crossed, but acceleration via a novel serpentine channel is so rapid that no significant beam disruption is observed. This result has significant implications for future particle accelerators, particularly muon and high-intensity prot...

  6. Magnets

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)

  7. Compact and energy saving magnet technology for particle accelerators

    International Nuclear Information System (INIS)

    Baurichter, A.

    2013-01-01

    Despite the fact that funding agencies and industrial users of particle accelerators get more and more alerted about costs of civil engineering, installation and operation, only little effort has been put into development of sustainable, energy and cost saving accelerator technology. In order to reduce the total-cost-of ownership of accelerator magnets, operating at high electrical power for twenty years or more, permanent magnet based Green Magnet technology has been developed at a consortium around Danfysik's R and D team. Together with our partners from ISA, Aarhus University, the Aarhus School of Engineering, the company Sintex and Aalborg University all obstacles in applying permanent magnet technology as e.g. thermal drift and inhomogeneities of magnetic fields have been overcome. The first Green Magnet has now been operated for more than half a year in an Accelerator Mass Spectrometry facility at the ETH in Zurich. The performance of this B=0.43T 90 deg. H-type bending magnet and the most recently builtB=1T, 30 deg. C-type Green Magnet for the synchrotron light source ASTRID2 at ISA in Aarhus will be presented. Danfysik also is designing, manufacturing and testing 60 compact magnet systems, developed at MAX-Lab for the new MAXIV 3.0 GeV synchrotron light source. In addition, 12 for the 1.5 GeV light source and another 12 for the new SOLARIS light source in Krakow, Poland are buying built. Up to a dozen or more magnet functions have been integrated into one yoke of these compact magnet systems, which makes the new MAXIV light sources compact, energy saving and at the same time very bright. Test results and design concepts of the new MAXIV and SOLARIS magnets will be presented. (author)

  8. Tunnetades kuumust / Emma Duncan

    Index Scriptorium Estoniae

    Duncan, Emma

    2006-01-01

    Autor prognoosib, et juba lähiajal hakkavad Valitsustevahelise Kliimamuutuste Ekspertrühma (IPCC- Intergovernmental Panel on Climate Change) aruanded mõjutama poliitikakujundamist maailmas. Diagramm: Elavhõbedasammas kerkib

  9. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  10. Fundamentos Curriculares del Liceo Laboratorio Emma Gamboa: Construcción teórica a partir de una Institución Participativa

    Directory of Open Access Journals (Sweden)

    Gurdián Fernández, Alicia

    2002-12-01

    Full Text Available Este artículo presenta los fundamentos teóricos del Proyecto Pedagógico del Liceo Laboratorio Emma Gamboa elaborados por las investigadoras a partir de una reflexión teórica que retoma la visión y la misión con las que se creó el Liceo, la percepción y el análisis en el marco de una evaluación curricular llevada a cabo por las investigadoras, el personal docente y docente administrativo. Estos fundamentos son resultado de una investigación participativa que permitió al personal docente y docente administrativo del período de 1996 a 1998, definir las premisas conceptuales que caracterizan a ese proyecto curricular desde un punto de vista epistemológico.

  11. “La excavación” de Roa Bastos y “Emma Zunz” de Borges, en honor a la verdad

    Directory of Open Access Journals (Sweden)

    Cecilia Rubio Rubio

    2014-06-01

    Full Text Available En este artículo presento la relación intertextual entre el relato “La excavación” (El trueno entre las hojas, 1953 de Augusto Roa Bastos y el borgia- no “Emma Zunz” (El Aleph, 1949, a partir del análisis contrastivo. Ade- más, presento y comento la segunda versión de “La excavación” (Madera quemada, 1967 y la comparo con la primera, advirtiendo el alejamiento de la intertextualidad con Borges. Finalmente, someto a interpretación este cambio, comentando la distinción entre “verdad moral” y “verdad factual” que se presenta en los dos relatos.

  12. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  13. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  14. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  15. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  16. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  17. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  18. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  19. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  20. The Conflict between Lived Religion and State Control of Poor Relief. The Case of Emma Mäkinen’s Private Orphanage at the Turn of the 20th Century

    Directory of Open Access Journals (Sweden)

    Annola Johanna

    2015-10-01

    Full Text Available The article discusses the conflict between lived religion and the state control of poor relief in a modernizing society by analysing the case of Emma Mäkinen’s private orphanage. Emma Mäkinen’s philanthropic work among neglected children was motivated by her Evangelical Revivalist conviction. Because of her trust in the transformative power of faith, she considered it appropriate to establish an orphanage next to a shelter for ‘fallen’ women. This decision led her onto a collision course with the State Inspector of Poor Relief and the general public, who did not share her religious views but emphasized the legislative and moral aspects vis-à-vis organizing social work. The conflict demonstrates, firstly, how the ancien régime and the traditional religious authority of the Evangelical Lutheran state church in particular was challenged by individual agency in voluntary associations such as the Evangelical Revivalist Free Mission. Secondly, the case of Emma Mäkinen’s orphanage reflects how new kinds of boundaries were created by the encroaching of state control into the sphere of private philanthropy, followed by the strengthening role of scientific theories and nationalistic thinking in social work. Thirdly, the conflict opens up a view on border-crossings, thus emphasizing the undefined nature of a modernizing society.

  1. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  2. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  3. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  4. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  5. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  6. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  7. 19.gadsimta Anglijas naratīvs japāņu animācijas seriālā „Emma: A Victorian Romance”

    OpenAIRE

    Čiževska, Inese

    2014-01-01

    Bakalaura darba mērķis ir noskaidrot, kā ar dažādiem stāstījuma veidiem, zīmēm un simboliem tiek reprezentēta 19.gs.Anglija, kādas ir līdzīgās un atšķirīgās iezīmes starp vēsturisko un animācijas seriālā atveidoto vidi. Darbā tiek analizēts japāņu animācijas seriāls „Emma: A Victorian Romance”. Empīriskie dati iegūti, veicot naratīva analīzi un semiotisko analīzi, ar kuru palīdzību tiks noskaidrots, kā caur japāņu kultūras prizmu tiek attēlota 19.gs. Anglija. Iegūtie rezultāti sniedz inf...

  8. Magnetic

    Science.gov (United States)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  9. MAGNET

    CERN Multimedia

    Benoit Curé

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  10. MAGNET

    CERN Document Server

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  11. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  12. Improved Peak Capacity for Capillary Electrophoretic Separations of Enzyme Inhibitors with Activity-Based Detection Using Magnetic Bead Microreactors

    Science.gov (United States)

    Yan, Xiaoyan; Gilman, S. Douglass

    2010-01-01

    A technique for separating and detecting enzyme inhibitors was developed using capillary electrophoresis with an enzyme microreactor. The on-column enzyme microreactor was constructed using NdFeB magnet(s) to immobilize alkaline phosphatase-coated superparamagnetic beads (2.8 μm diameter) inside a capillary before the detection window. Enzyme inhibition assays were performed by injecting a plug of inhibitor into a capillary filled with the substrate, AttoPhos. Product generated in the enzyme microreactor was detected by laser-induced fluorescence. Inhibitor zones electrophoresed through the capillary, passed through the enzyme microreactor, and were observed as negative peaks due to decreased product formation. The goal of this study was to improve peak capacities for inhibitor separations relative to previous work, which combined continuous engagement electrophoretically mediated microanalysis (EMMA) and transient engagement EMMA to study enzyme inhibition. The effects of electric field strength, bead injection time and inhibitor concentrations on peak capacity and peak width were investigated. Peak capacities were increased to ≥20 under optimal conditions of electric field strength and bead injection time for inhibition assays with arsenate and theophylline. Five reversible inhibitors of alkaline phosphatase (theophylline, vanadate, arsenate, L-tryptophan and tungstate) were separated and detected to demonstrate the ability of this technique to analyze complex inhibitor mixtures. PMID:20024913

  13. Magnets and magnetic materials

    International Nuclear Information System (INIS)

    Meuris, Ch.; Rifflet, J.M.

    2007-01-01

    The Large Hadron Collider (LHC), the world's largest highest-energy particle collider that the CERN plans to commission in 2008, gets a double boost from superconducting magnet technology. Superconducting magnets are first used to guide the particles scheduled for collision through the accelerator, and then to observe the events triggered by the collision inside giant detectors in a known magnetic field. Despite the installation's massive dimensions, all this is done with minimal expenditure of energy. (author)

  14. Magnetism and magnetic materials

    International Nuclear Information System (INIS)

    1990-01-01

    It describes the actual status of physics in Brazil concerning the study of magnetism and magnetic materials. It gives an overview of different research groups in Brazil, their needs, as well as the investments needed to improve the area. (A.C.A.S.)

  15. Specialty magnets

    International Nuclear Information System (INIS)

    Halbach, K.

    1986-07-01

    A number of basic conceptual designs are explained for magnet systems that use permanent magnet materials. Included are iron free multipoles and hybrid magnets. Also appended is a discussion of the manufacturing process and magnetic properties of some permanent magnet materials

  16. Magnetic Spinner

    Science.gov (United States)

    Ouseph, P. J.

    2006-01-01

    A science toy sometimes called the "magnetic spinner" is an interesting class demonstration to illustrate the principles of magnetic levitation. It can also be used to demonstrate Faraday's law and a horizontally suspended physical pendulum. The levitated part contains two circular magnets encased in a plastic housing. Each magnet stays…

  17. Magnetic skyrmions

    Science.gov (United States)

    2018-06-01

    Welcome to the special issue of Journal of Magnetism and Magnetic Materials on magnetic skyrmions. We are proud to present, with great pleasure, a timely collection of 9 original research articles on the recent hot topic "magnetic skyrmions" which studies the static and dynamic properties of skyrmions and the methods to control them in a variety of ways, including magnetic field, electric current and applied strain.

  18. Superconducting Magnets

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Starting from the beam requirements for accelerator magnets, we will outline the main issues and the physical limitations for producing strong and pure magnetic fields with superconductors. The seminar will mainly focus on the magnets for the accelerator, and give some hints on the magnets for the experiments. Prerequisite knowledge: Basic knowledge of Maxwell equations, and linear optics for particle accelerators (FODO cell, beta functions).

  19. Magnetic strings

    International Nuclear Information System (INIS)

    Chaves, Max

    2006-01-01

    The conception of the magnetic string is presented as an infinitely thin bundle of magnetic flux lines. The magnetic strings are surrounded by a film of current that rotates around them, and are a solution of Maxwell's equations. The magnetic potential contains a line singularity, and its stability can be established topologically. A few comments are added on the possibility that they may exist at a cosmological scale as relics of the Big Bang. (author) [es

  20. Magnetic Materials

    Science.gov (United States)

    Spaldin, Nicola A.

    2003-04-01

    Magnetic materials are the foundation of multi-billion dollar industries and the focus of intensive research across many disciplines. This book covers the fundamentals, basic theories and applications of magnetism and conventional magnetic materials. Based on a lecture course given by Nicola Spaldin in the Materials Department at University of California, Santa Barbara, the book is ideal for a one- semester course in magnetic materials. It contains numerous homework problems and solutions.

  1. Automated Modular Magnetic Resonance Imaging Clinical Decision Support System (MIROR): An Application in Pediatric Cancer Diagnosis.

    Science.gov (United States)

    Zarinabad, Niloufar; Meeus, Emma M; Manias, Karen; Foster, Katharine; Peet, Andrew

    2018-05-02

    Advances in magnetic resonance imaging and the introduction of clinical decision support systems has underlined the need for an analysis tool to extract and analyze relevant information from magnetic resonance imaging data to aid decision making, prevent errors, and enhance health care. The aim of this study was to design and develop a modular medical image region of interest analysis tool and repository (MIROR) for automatic processing, classification, evaluation, and representation of advanced magnetic resonance imaging data. The clinical decision support system was developed and evaluated for diffusion-weighted imaging of body tumors in children (cohort of 48 children, with 37 malignant and 11 benign tumors). Mevislab software and Python have been used for the development of MIROR. Regions of interests were drawn around benign and malignant body tumors on different diffusion parametric maps, and extracted information was used to discriminate the malignant tumors from benign tumors. Using MIROR, the various histogram parameters derived for each tumor case when compared with the information in the repository provided additional information for tumor characterization and facilitated the discrimination between benign and malignant tumors. Clinical decision support system cross-validation showed high sensitivity and specificity in discriminating between these tumor groups using histogram parameters. MIROR, as a diagnostic tool and repository, allowed the interpretation and analysis of magnetic resonance imaging images to be more accessible and comprehensive for clinicians. It aims to increase clinicians' skillset by introducing newer techniques and up-to-date findings to their repertoire and make information from previous cases available to aid decision making. The modular-based format of the tool allows integration of analyses that are not readily available clinically and streamlines the future developments. ©Niloufar Zarinabad, Emma M Meeus, Karen Manias

  2. Superconducting magnets

    International Nuclear Information System (INIS)

    1994-08-01

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-T c superconductor at low temperature

  3. Superconducting magnets

    International Nuclear Information System (INIS)

    Willen, E.

    1996-01-01

    Superconducting dipole magnets for high energy colliders are discussed. As an example, the magnets recently built for the Relativistic Heavy Ion Collider at Brookhaven are reviewed. Their technical performance and the cost for the industry-built production dipoles are given. The cost data is generalized in order to extrapolate the cost of magnets for a new machine

  4. Magnetic Hysteresis

    CERN Document Server

    Della Torre, Edward

    2000-01-01

    Understanding magnetic hysteresis is vitally important to the development of the science of magnetism as a whole and to the advancement of practical magnetic device applications. Magnetic Hysteresis, by acclaimed expert Edward Della Torre, presents a clear explanation of the connection between physical principles and phenomenological hysteresis. This comprehensive book offers a lucid analysis that enables the reader to save valuable time by reducing trial-and-error design. Dr. Della Torre uses physical principles to modify Preisach modeling and to describe the complex behavior of magnetic media. While Pretsach modeling is a useful mathematical tool, its congruency and deletion properties present limitations to accurate descriptions of magnetic materials. Step-by-step, this book describes the modifications that can overcome these limitations. Special attention is given to the use of feedback around a Preisach transducer to remove the congruency restriction, and to the use of accommodation and aftereffect model...

  5. Planetary Magnetism

    Science.gov (United States)

    Connerney, J. E. P.

    2007-01-01

    The chapter on Planetary Magnetism by Connerney describes the magnetic fields of the planets, from Mercury to Neptune, including the large satellites (Moon, Ganymede) that have or once had active dynamos. The chapter describes the spacecraft missions and observations that, along with select remote observations, form the basis of our knowledge of planetary magnetic fields. Connerney describes the methods of analysis used to characterize planetary magnetic fields, and the models used to represent the main field (due to dynamo action in the planet's interior) and/or remnant magnetic fields locked in the planet's crust, where appropriate. These observations provide valuable insights into dynamo generation of magnetic fields, the structure and composition of planetary interiors, and the evolution of planets.

  6. Magnetic levitation

    OpenAIRE

    Štěpánek,B.; Paleček,M.

    2015-01-01

    The paper deals with magnetism and its influence on superconducting materials. We describe the discovery and development of superconductivity, superconducting levitation and its use in future technology - called. MAGLEV speed trains. We show the interaction of the magnetic field of a strong neodymium magnet and high-temperature superconductor, cooled with liquid nitrogen at about -200 ° C. Of superconductors at this temperature becomes perfect diamagnetic material. That is ejected from the ma...

  7. Magnet Systems

    Data.gov (United States)

    Federal Laboratory Consortium — Over the decades, Fermilab has been responsible for the design, construction, test and analysis of hundreds of conventional and superconducting accelerator magnets...

  8. Planetary Magnetism

    International Nuclear Information System (INIS)

    Russell, C.T.

    1980-01-01

    Planetary spacecraft have now probed the magnetic fields of all the terrestrial planets, the moon, Jupiter, and Saturn. These measurements reveal that dynamos are active in at least four of the planets, Mercury, the earth, Jupiter, and Saturn but that Venus and Mars appear to have at most only very weak planetary magnetic fields. The moon may have once possessed an internal dynamo, for the surface rocks are magnetized. The large satellites of the outer solar system are candidates for dynamo action in addition to the large planets themselves. Of these satellites the one most likely to generate its own internal magnetic field is Io

  9. Magnetics Processing

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetics Processing Lab equipped to perform testing of magnetometers, integrate them into aircraft systems, and perform data analysis, including noise reduction...

  10. Magnetic starspots

    International Nuclear Information System (INIS)

    Jahn, K.; Stepien, K.

    1984-01-01

    Models of large magnetic starspots with an axisymmetric untwisted magnetic field on late type stars are discussed. It is assumed that the magnetic field reduces the efficiency of convection inside the spot. A unique relation between the stellar mass and the difference of effective temperatures of the spot and the surrounding photosphere is adopted from observations. It is equivalent to the reduction of a s (the mixing length theory parameter) inside the spot to the value 0.15 independently of the stellar mass. The surface magnetic field of large spots covering a considerable part of the stellar surface is a decreasing function of the magnetic flux. Hence a coverage of a star by magnetic regions rapidly increases as a function of the magnetic flux in a narrow range of fluxes. This behaviour can explain the Vaughan-Preston gap. Recent observations of magnetic fields on G and K type stars are in a good agreement with our predictions. 35 refs., 3 figs., 4 tabs. (author)

  11. Magnetic superlattices

    International Nuclear Information System (INIS)

    Kwo, J.; Hong, M.; McWhan, D.B.; Yafet, Y.; Fleming, R.M.; DiSalvo, F.J.; Waszczak, J.V.; Majkrzak, C.F.; Gibbs, D.; Goldmann, A.I.; Boni, P.; Bohr, J.; Grimm, H.; Bohr, J.; Chien, C.L.; Grimm, H.; Cable, J.W.

    1988-01-01

    Single crystal magnetic rare earth superlattices were synthesized by molecular beam epitaxy. The studies include four rare earth systems: Gd-Y, Dy-Y, Ho-Y, and Gd-Dy. The magnetic properties and the long-range spin order are reviewed in terms of the interfacial behavior, and the interlayer exchange coupling across Y medium

  12. Magnetic Field

    DEFF Research Database (Denmark)

    Olsen, Nils

    2015-01-01

    he Earth has a large and complicated magnetic field, the major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. Magnetic field observations provide one of the few tools for remote sensing the Earth’s deep interior, especially regarding the dynamics...... of the fluid flow at the top of the core. However, what is measured at or near the surface of the Earth is the superposition of the core field and fields caused by magnetized rocks in the Earth’s crust, by electric currents flowing in the ionosphere, magnetosphere, and oceans, and by currents induced...... in the Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field...

  13. Lunar magnetism

    Science.gov (United States)

    Hood, L. L.; Sonett, C. P.; Srnka, L. J.

    1984-01-01

    Aspects of lunar paleomagnetic and electromagnetic sounding results which appear inconsistent with the hypothesis that an ancient core dynamo was the dominant source of the observed crustal magnetism are discussed. Evidence is summarized involving a correlation between observed magnetic anomalies and ejecta blankets from impact events which indicates the possible importance of local mechanisms involving meteoroid impact processes in generating strong magnetic fields at the lunar surface. A reply is given to the latter argument which also presents recent evidence of a lunar iron core.

  14. Rare earth permanent magnet with easy magnetization

    International Nuclear Information System (INIS)

    Kim, A.S.; Camp, F.E.

    1998-01-01

    Rare earth permanent magnets have high energy products and coercivities, and thus the volume miniaturization of magnetic devices has been possible with improved magnetic performance. Although the high energy products of these rare earth permanent magnets provide substantial advantages for magnetic design and application, the strong magnetic force of the magnetized magnets makes assembly difficult. Therefore, a special device is needed to assemble the magnetized magnets. On the other hand, unmagnetized magnets are assembled and then they are magnetized. The assembled magnets are generally more difficult to magnetize than unassembled magnets because a much less effective magnetic field may be applied to them. This is particularly true for the rare earth permanent magnets because they usually need a much higher magnetic field to be fully magnetized than alnico or ferrite magnets. To obtain optimum magnetic properties, the required minimum magnetizing fields for SmCo 5 , Sm 2 TM 17 and Nd 2 Fe 14 B magnets were reported as 25-30 kOe, 45-60 kOe and 25-30 kOe, respectively. If the required magnetizing field for full saturation could be lowered, the effective utilization of magnetic properties would be maximized and the magnetic design option could be expanded with reduced restrictions. To meet this demand, we have sought to lower the field required for full magnetic saturation, and found that an increase in Dy content in R-(Fe,Co,Cu)-B type magnets lowers the field required for full saturation as well as improves the temperature stability. By increasing the H ci with Dy addition from 14 kOe to 24 and 34 kOe, the field required for full magnetic saturation decreases from about 20 to 15 and 10 kOe, respectively. This dual benefit will open up new application areas with more freedom for magnet design options. The mechanism for the lower magnetizing fields will be discussed. (orig.)

  15. Magnetic monopoles

    International Nuclear Information System (INIS)

    Fryberger, D.

    1984-12-01

    In this talk on magnetic monopoles, first the author briefly reviews some historical background; then, the author describes what several different types of monopoles might look like; and finally the author discusses the experimental situation. 81 references

  16. Quantum magnetism

    CERN Document Server

    Richter, Johannes; Farnell, Damian; Bishop, Raymod

    2004-01-01

    The investigation of magnetic systems where quantum effects play a dominant role has become a very active branch of solid-state-physics research in its own right. The first three chapters of the "Quantum Magnetism" survey conceptual problems and provide insights into the classes of systems considered, namely one-dimensional, two-dimensional and molecular magnets. The following chapters introduce the methods used in the field of quantum magnetism, including spin wave analysis, exact diagonalization, quantum field theory, coupled cluster methods and the Bethe ansatz. The book closes with a chapter on quantum phase transitions and a contribution that puts the wealth of phenomena into the context of experimental solid-state physics. Closing a gap in the literature, this volume is intended both as an introductory text at postgraduate level and as a modern, comprehensive reference for researchers in the field.

  17. Magnetic monopoles

    International Nuclear Information System (INIS)

    Preskill, J

    1984-01-01

    This article offers a review of the physics of the magnetic monopole, which, although as yet unseen, offers sound theoretical reasons to believe that it must exist. Several theories are presented and equations are given. The idea that magnetic monopoles, stable particles carrying magnetic charges, ought to exist has, according to the authors, proved to be very durable. One theory presented demonstrates the consistency of magnetic monopoles with quantum electrodynamics. Another theory demonstrates the necessity of monopoles in grand unified gauge theories. The authors believe it is reasonable to expect the monopole to be an extremely heavy stable elementary particle. The stability of the classical monopole solution given is ensured by a topological principle explained

  18. Magnetic Bacteria.

    Science.gov (United States)

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  19. LHC magnets

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Preparations for the LHC proton collider to be built in CERN's LEP tunnel continue to make good progress. In particular development work for the high field superconducting magnets to guide the almost 8 TeVproton beams through the 'tight' curve of the 27-kilometre ring are proceeding well, while the magnet designs and lattice configuration are evolving in the light of ongoing experience. At the Evian LHC Experiments meeting, this progress was covered by Giorgio Brianti

  20. Superconducting magnet

    Science.gov (United States)

    1985-01-01

    Extensive computer based engineering design effort resulted in optimization of a superconducting magnet design with an average bulk current density of approximately 12KA/cm(2). Twisted, stranded 0.0045 inch diameter NbTi superconductor in a copper matrix was selected. Winding the coil from this bundle facilitated uniform winding of the small diameter wire. Test coils were wound using a first lot of the wire. The actual packing density was measured from these. Interwinding voltage break down tests on the test coils indicated the need for adjustment of the wire insulation on the lot of wire subsequently ordered for construction of the delivered superconducting magnet. Using the actual packing densities from the test coils, a final magnet design, with the required enhancement and field profile, was generated. All mechanical and thermal design parameters were then also fixed. The superconducting magnet was then fabricated and tested. The first test was made with the magnet immersed in liquid helium at 4.2K. The second test was conducted at 2K in vacuum. In the latter test, the magnet was conduction cooled from the mounting flange end.

  1. Magnetizing of permanent magnet using HTS bulk magnet

    International Nuclear Information System (INIS)

    Oka, Tetsuo; Muraya, Tomoki; Kawasaki, Nobutaka; Fukui, Satoshi; Ogawa, Jun; Sato, Takao; Terasawa, Toshihisa

    2011-01-01

    A demagnetized Nd-Fe-B permanent magnet was scanned just above the magnetic pole containing the HTS bulk magnet, generating a magnetic field of 3.27 T. The magnet sample was subsequently found to be fully magnetized in the open space of the static magnetic fields. We examined the magnetic field distributions when the magnetic poles were scanned twice to activate the magnetic plates inversely with various overlap distances between the tracks of the HTS bulk magnet. The magnetic field of the 'rewritten' magnet reached the values of the magnetically saturated region of the material, showing steep gradients at the border of each magnetic pole. As a replacement for conventional pulse field magnetizing methods, this technique is proposed to expand the degree of freedom in the design of electromagnetic devices, and is proposed as a novel practical method for magnetizing rare-earth magnets, which have excellent magnetic performance and require intense fields of more than 3 T to be activated. (author)

  2. Magnetic spring based on two permanent magnets

    International Nuclear Information System (INIS)

    Tsivilitsin, V.Yu.; Mil'man, Yu.V.; Goncharuk, V.A.; Bondar, I.B.

    2011-01-01

    A new type of the magnetic spring construction 'two permanent magnets' has been considered. A mathematical expression for the estimation of a pulling-in force has been offered. This expression is verified experimentally on the produced operating magnetic spring. The theoretical and experimental data are in good accordance. A number of advantages of the magnetic spring over the construction 'permanent magnet - magnetic circuit' such as an insignificant friction force between two magnets and a higher pulling force are discussed.

  3. Magnetic reheating

    Science.gov (United States)

    Saga, Shohei; Tashiro, Hiroyuki; Yokoyama, Shuichiro

    2018-02-01

    We provide a new bound on the amplitude of primordial magnetic fields (PMFs) by using a novel mechanism, magnetic reheating. The damping of the magnetohydrodynamics fluid motions in a primordial plasma brings the dissipation of the PMFs. In the early Universe with z ≳ 2 × 106, cosmic microwave background (CMB) photons are quickly thermalized with the dissipated energy and shift to a different Planck distribution with a new temperature. In other words, the PMF dissipation changes the baryon-to-photon number ratio, and we name such a process magnetic reheating. From the current baryon-to-photon number ratio obtained from the big bang nucleosynthesis and CMB observations, we put the strongest constraint on the PMFs on small scales which CMB observations cannot access, B0 ≲ 1.0 μG at the scales 104 generation mechanisms of PMFs in the early Universe.

  4. Magnetic monopoles and dipoles

    CERN Multimedia

    Dominguez, Daniel

    2016-01-01

    Conventional bar magnets are also called ‘magnetic dipoles’ because they have two magnetic poles (a “North” and a “South” magnetic pole, like the Earth). In theory, “magnetic monopoles” could exist that act like an isolated “magnetic charge”, i.e. either a “North” or a “South” magnetic pole.

  5. Designing a magnet for magnetic refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerk, R

    2010-03-15

    This thesis investigates the design and optimization of a permanent magnet assembly for use in a magnetic refrigeration device. The heart of magnetic refrigeration is the adiabatic temperature change in the magnetocaloric material which is caused by the magnetic field. In order to design an ideal magnet assembly the magnetocaloric materials and the refrigeration process itself and their properties and performance as a function of magnetic field are investigated. For the magnetocaloric materials it is the magnetization, specific heat capacity and adiabatic temperature that are investigated as functions of the magnetic field. Following this the process utilized by a magnetic refrigerator to provide cooling is investigated using a publicly available one dimensional numerical model. This process is called active magnetic regeneration (AMR). The aim is to determine the performance of the AMR as a function of the magnetic field in order to learn the properties of the optimal magnet assembly. The performance of the AMR as a function of the synchronization and width of the magnetic field with respect to the AMR cycle, the ramp rate and maximum value of the magnetic field are investigated. Other published magnet designs used in magnetic refrigeration devices are also evaluated, using a figure of merit based on the properties of the investigated magnetocaloric materials, to learn the properties of the best magnet designs to date. Following this investigation the Halbach cylinder, which is a hollow permanent magnet cylinder with a rotating remanent flux density, is investigated in detail as it forms the basis of many magnet designs used in magnetic refrigeration. Here the optimal dimensions of a Halbach cylinder, as well as analytical calculations of the magnetic field for a Halbach cylinder of infinite length, are presented. Once it has been determined which properties are desirable for a magnet used in magnetic refrigeration the design of a new magnet is described. This is

  6. Magnetic collectors

    International Nuclear Information System (INIS)

    Frew, J.D.

    1980-01-01

    A collector for use in a magnetic separator is formed by isostatically pressing a metal which is resistant to attack by acid about ferromagnetic bodies whereby to encase the bodies in the metal. In one arrangement, as shown, the bodies are encapsulated between inner and outer cylinders. In other arrangements the encapsulating metal is in the form of a tube or planar sheets. The bodies are of Fe or an oxide thereof and the acid-resistant metal parts may be of stainless steel, Au, Pt, Pa or an alloy. The magnetic separator is intended for use in removing particles from liquids during the reprocessing of nuclear fuel materials. (author)

  7. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1980-03-01

    The 'ingredients' which control a phase transition in well defined system as well as in random ones (e.g. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' we find the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  8. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1981-01-01

    The 'ingredients' which control a phase transition in well defined systems as well as in random ones (e.q. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system are found. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  9. Magnetic particles

    Science.gov (United States)

    Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)

    1989-01-01

    Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.

  10. Magnetics Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetics Research Facility houses three Helmholtz coils that generate magnetic fields in three perpendicular directions to balance the earth's magnetic field....

  11. Random magnetism

    International Nuclear Information System (INIS)

    Tahir-Kheli, R.A.

    1975-01-01

    A few simple problems relating to random magnetic systems are presented. Translational symmetry, only on the macroscopic scale, is assumed for these systems. A random set of parameters, on the microscopic scale, for the various regions of these systems is also assumed. A probability distribution for randomness is obeyed. Knowledge of the form of these probability distributions, is assumed in all cases [pt

  12. Magnetic Design of Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Todesco, E [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    In this paper we discuss the main principles of magnetic design for superconducting magnets (dipoles and quadrupoles) for particle accelerators. We give approximated equations that govern the relation between the field/gradient, the current density, the type of superconductor (Nb−Ti or Nb3Sn), the thickness of the coil, and the fraction of stabilizer. We also state the main principle controlling the field quality optimization, and discuss the role of iron. A few examples are given to show the application of the equations and their validity limits.

  13. Neutron Scattering studies of magnetic molecular magnets

    International Nuclear Information System (INIS)

    Chaboussant, G.

    2009-01-01

    This work deals with inelastic neutron scattering studies of magnetic molecular magnets and focuses on their magnetic properties at low temperature and low energies. Several molecular magnets (Mn 12 , V 15 , Ni 12 , Mn 4 , etc.) are reviewed. Inelastic neutron scattering is shown to be a perfectly suited spectroscopy tool to -a) probe magnetic energy levels in such systems and -b) provide key information to understand the quantum tunnel effect of the magnetization in molecular spin clusters. (author)

  14. Enhancing the magnetic properties of magnetic nanoparticles

    DEFF Research Database (Denmark)

    Ahlburg, Jakob; Saura-Múzquiz, Matilde; Stingaciu, Marian

    with a similar magnetic performance. There are several different ways of enhancing magnetic properties of 3d magnetic compounds. This includes, size control, core-shell particles or mixing hard and soft magnetic materials together to achieve an exchange coupling between the compounds and enhancing the magnetic...... energy product. In order to control the particle size, a hydrothermal synthesis is preferred. This followed by reduction or the oxides into either core shell particles, or a mixture of magnetic oxides and a metallic phase....

  15. 2444-IJBCS-Article-Emma N'Draman Donou

    African Journals Online (AJOL)

    hp

    faite sur les prélèvements sanguins de 30 drépanocytaires homozygotes SSFA2. Après induction de la ... The study was done on the blood samples of 30 SSFA2 homozygote patients with sickle cell anemia. After induction of the sickling of red blood cells, the addition of the aqueous extract of the plant allowed the ...

  16. Y Emma Bovary aprendió a hablar en gallego...

    Directory of Open Access Journals (Sweden)

    Cecilia Fernández Santomé

    2012-05-01

    Full Text Available Les traductions des œuvres de Flaubert sont nombreuses. Cet abondant flux de versions comporte une multiplicité de solutions aux « problèmes » que les textes flaubertiens peuvent poser au médiateur linguistique. Ainsi, l’adaptation de leur esthétique particulière et du ton général de l’écriture ne repose pas toujours sur les mêmes stratégies formelles, qui varient suivant les traits du système littéraire récepteur de l’œuvre traduite. Pourtant, la traduction en galicien de Madame Bovary est imprégnée non seulement des caractéristiques propres à cette langue, mais encore des dispositions inhérentes à un champ littéraire encore peu consolidé.Flaubert’s works have been translated into an important number of languages all around the world. These versions present different solutions to the “problems” of Flaubert’s style. In fact, translated books content many aesthetic and formal modifications that are intimately related to the strategies actives into the literary system that receives the resultant text. However, there is a kind of double gaze in the translator’s work that hides the simultaneous development of other aspects that are not literary features. The Galician translation of Madame Bovary shows how stylistic choices are determined by extra-literary politics into a cultural system that is already not completely consolidated.Son muchas las traducciones existentes de las obras de Flaubert. Esta multitud de versiones conlleva la existencia de múltiples soluciones a los “problemas” que los textos de origen presentan al traductor. De hecho, la adaptación de la particular estética de los mismos y del tono general de su escritura no sigue un patrón único, al variar en función de las características inherentes al sistema literario receptor de la obra traducida. Es más, el respeto al principio de literalidad o las libertades del traductor, disimulan aspectos más allá de lo estrictamente literario y que también conviene tener en cuenta. La traducción al gallego de Madame Bovary está impregnada no solamente de las disposiciones lingüísticas propias de dicho idioma, sino que en ella pueden descifrarse algunos de los rasgos que afectan al desarrollo de un campo literario aún en proceso de consolidación.

  17. How can the EMMA approach to learning analytics improve employability?

    NARCIS (Netherlands)

    Brouns, Francis; Tammets, Kairit; Padrón-Nápoles, Carmen

    2014-01-01

    In our current society there is a strong need for citizens to work on their employability and to develop key competences. Developing those competences should starts during formal education, but maintained throughout working life. MOOCs can accommodate several of the needs of the lifelong learners.

  18. Bootcamp EMMA MOOC Assessment for learning in practice

    NARCIS (Netherlands)

    Firssova, Olga; Brouns, Francis

    2016-01-01

    Formative assessment or assessment for learning is a relevant theme for teachers and educationalists. Formative assessment is a valuable tool for supporting the learning process. It is applied during learning and offers you more and better opportunities to guide your students. Formative assessment

  19. Magnetic resonance annual 1986

    International Nuclear Information System (INIS)

    Kressel, H.Y.

    1986-01-01

    This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging

  20. Designing a magnet for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

    This thesis investigates the design and optimization of a permanent magnet assembly for use in a magnetic refrigeration device. The heart of magnetic refrigeration is the adiabatic temperature change in the magnetocaloric material which is caused by the magnetic field. In order to design an ideal...... magnet assembly the magnetocaloric materials and the refrigeration process itself and their properties and performance as a function of magnetic field are investigated. For the magnetocaloric materials it is the magnetization, specific heat capacity and adiabatic temperature that are investigated...... as a function of the magnetic field in order to learn the properties of the optimal magnet assembly. The performance of the AMR as a function of the synchronization and width of the magnetic field with respect to the AMR cycle, the ramp rate and maximum value of the magnetic field are investigated. Other...

  1. Magnetic monopoles

    International Nuclear Information System (INIS)

    Shnir, Ya.M.

    2005-01-01

    This monograph addresses the field theoretical aspects of magnetic monopoles. Written for graduate students as well as researchers, the author demonstrates the interplay between mathematics and physics. He delves into details as necessary and develops many techniques that find applications in modern theoretical physics. This introduction to the basic ideas used for the description and construction of monopoles is also the first coherent presentation of the concept of magnetic monopoles. It arises in many different contexts in modern theoretical physics, from classical mechanics and electrodynamics to multidimensional branes. The book summarizes the present status of the theory and gives an extensive but carefully selected bibliography on the subject. The first part deals with the Dirac monopole, followed in part two by the monopole in non-abelian gauge theories. The third part is devoted to monopoles in supersymmetric Yang-Mills theories. (orig.)

  2. magnetic horn

    CERN Document Server

    Neutrinos and antineutrinos are ideal for probing the weak force because it is effectively the only force they feel. How were they made? Protons fired into a metal target produce a tangle of secondary particles. A magnetic horn like this one, invented by Simon Van der Meer, selected pions and focused them into a sharp beam. Pions decay into muons and neutrinos or antineutrinos. The muons were stopped in a wall of 3000 tons of iron and 1000 tons of concrete, leaving the neutrinos or antineutrinos to reach the Gargamelle bubble chamber. A simple change of magnetic field direction on the horn flipped between focusing positively- or negatively-charged pion beams, and so between neutrinos and antineutrinos.

  3. Magnetic Reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Masaaki Yamada, Russell Kulsrud and Hantao Ji

    2009-09-17

    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.

  4. Planetary magnetism

    International Nuclear Information System (INIS)

    Dolginov, Sh.Sh.

    1977-01-01

    Experimental data on magnetic fields of planets are surveyed. The magnetic fields of the Earth, Jupiter, Mars, Mercury, Venus, and the Moon are considered in detail. A similarity of the physical models of both the planets of the Earth group and the giant planets was revealed. The fields of the planets and of the Earth are compared in the scheme of the precession dynamo and in the kinematic scheme. Proceeding from the assumption that the Poincare forces and their ratio to other forces are model-similar in the cores of all the planets, the values of Hsub(i)/Hsub(E) are calculated, where Hsub(i) and Hsub(E) are the field strengths of the i-th planet and that of the Earth. The experimental data on the dynamic compression of the Mercury confirm the calculations made. It is concluded that the problem of the origin and moving forces of the terrestrial magnetic field may be resolved only within the framework of comparative planetology

  5. MAGNET / INFRASTRUCTURE

    CERN Multimedia

    D. Campi

    The final fast discharge of the Magnet took place on 3rd of November. The Coil reached a temperature of 70K by internal energy dissipation. By injecting a current of 200 A room temperature was reached on the 23rd November. During the heating of the coil un-connecting of the first magnet connectors on YBO was started to give the earliest possible access to the assembly groups and to continue the installation of the muon chambers. The removal of the pumping lines and the disconnection of the vacuum system was instead done as soon as the room temperature was reached: more precisely from the 4 to the 18 December. The disconnection of the transfer line from the cold box and the completion of the removal of the control cables of the vacuum system and cryogenics was done at last. In January 2007 the disconnection of MCS-MSS, CDS, vacuum racks and their cable trays was also achieved. After coil disconnection the effort of the magnet team has been mainly devoted in optimizing the lowering and reassembly of the a...

  6. Magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bihler, Christoph

    2009-04-15

    In this thesis we investigated in detail the properties of Ga{sub 1-x}Mn{sub x}As, Ga{sub 1-x}Mn{sub x}P, and Ga{sub 1-x}Mn{sub x}N dilute magnetic semiconductor thin films with a focus on the magnetic anisotropy and the changes of their properties upon hydrogenation. We applied two complementary spectroscopic techniques to address the position of H in magnetic semiconductors: (i) Electron paramagnetic resonance, which provides direct information on the symmetry of the crystal field of the Mn{sup 2+} atoms and (ii) x-ray absorption fine structure analysis which allows to probe the local crystallographic neighborhood of the absorbing Mn atom via analysing the fine structure at the Mn K absorption edge. Finally, we discussed the obstacles that have to be overcome to achieve Curie temperatures above the current maximum in Ga{sub 1-x}Mn{sub x}As of 185 K. Here, we outlined in detail the generic problem of the formation of precipitates at the example of Ge:MN. (orig.)

  7. Magnetic Reconnection

    International Nuclear Information System (INIS)

    Yamada, Masaaki; Kulsrud, Russell; Ji, Hantao

    2009-01-01

    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-fluid 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 briefly discussed.

  8. Magnetic elements for switching magnetization magnetic force microscopy tips

    International Nuclear Information System (INIS)

    Cambel, V.; Elias, P.; Gregusova, D.; Martaus, J.; Fedor, J.; Karapetrov, G.; Novosad, V.

    2010-01-01

    Using combination of micromagnetic calculations and magnetic force microscopy (MFM) imaging we find optimal parameters for novel magnetic tips suitable for switching magnetization MFM. Switching magnetization MFM is based on two-pass scanning atomic force microscopy with reversed tip magnetization between the scans. Within the technique the sum of the scanned data with reversed tip magnetization depicts local atomic forces, while their difference maps the local magnetic forces. Here we propose the design and calculate the magnetic properties of tips suitable for this scanning probe technique. We find that for best performance the spin-polarized tips must exhibit low magnetic moment, low switching fields, and single-domain state at remanence. The switching field of such tips is calculated and optimum shape of the Permalloy elements for the tips is found. We show excellent correspondence between calculated and experimental results for Py elements.

  9. Magnetic Measurement and Magnet Tutorial, Part 3

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Jack

    2003-07-15

    Magnetic measurements, like magnet design, is a broad subject. It is the intention of this lecture to cover only a small part of the field, regarding the characterization of the line integral field quality of multipole magnets (dipoles, quadrupoles and sextupoles) using compensated rotating coils. Other areas which are not covered are magnet mapping, AC measurements and sweeping wire measurements.

  10. Surface magnetic field measurement with magnetic shielding

    Czech Academy of Sciences Publication Activity Database

    Perevertov, Oleksiy

    2010-01-01

    Roč. 61, č. 7 (2010), 66-68 ISSN 1335-3632 Grant - others:AVČR(CZ) M100100906 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic hysteresis * magnetic field measurement * magnetic shielding * extrapolation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.270, year: 2010

  11. An optimized magnet for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

    A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halbach cylinder magnet design and dimensioning and segmenting this design in an optimum way followed by the construction...... of the actual magnet. The final design generates a peak value of 1.24 T, an average flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an average low flux density of 0.08 T also in a 2 L volume. The working point of all the permanent magnet blocks in the design is very close...... to the maximum energy density. The final design is characterized in terms of a performance parameter, and it is shown that it is one of the best performing magnet designs published for magnetic refrigeration....

  12. An optimized magnet for magnetic refrigeration

    International Nuclear Information System (INIS)

    Bjork, R.; Bahl, C.R.H.; Smith, A.; Christensen, D.V.; Pryds, N.

    2010-01-01

    A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halbach cylinder magnet design and dimensioning and segmenting this design in an optimum way followed by the construction of the actual magnet. The final design generates a peak value of 1.24 T, an average flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an average low flux density of 0.08 T also in a 2 L volume. The working point of all the permanent magnet blocks in the design is very close to the maximum energy density. The final design is characterized in terms of a performance parameter, and it is shown that it is one of the best performing magnet designs published for magnetic refrigeration.

  13. Enhancing the magnetic properties of magnetic nanoparticles

    DEFF Research Database (Denmark)

    Ahlburg, Jakob; Saura-Múzquiz, Matilde; Stingaciu, Marian

    with a similar magnetic performance. There are several different ways of enhancing magnetic properties of 3d magnetic compounds. This includes, size control, core-shell particles or mixing hard and soft magnetic materials together to achieve an exchange coupling between the compounds and enhancing the magnetic...... energy product. In order to control the particle size, a hydrothermal synthesis is preferred. This followed by reduction or the oxides into either core shell particles, or a mixture of magnetic oxides and a metallic phase.......Strong magnets with a high energy product are vital when optimizing the efficiency in the electric industry. But since the rare earth metals, normally used for making strong permanent magnets, are both expensive and difficult to mine, a great demand has come to cheaper types of magnets...

  14. Magnetization reversal in ultrashort magnetic field pulses

    International Nuclear Information System (INIS)

    Bauer, M.; Lopusnik, R.; Fassbender, J.; Hillebrands, B.

    2000-01-01

    We report the switching properties of a thin magnetic film subject to an ultrashort, laterally localized magnetic field pulse, obtained by numerical investigations. The magnetization distribution in the film is calculated on a grid assuming Stoner-like coherent rotation within the grid square size. Perpendicularly and in-plane magnetized films exhibit a magnetization reversal due to a 4 ps magnetic field pulse. Outside the central region the pulse duration is short compared to the precession period. In this area the evolution of the magnetization during the field pulse does not depend strongly on magnetic damping and/or pulse shape. However, the final magnetization distribution is affected by the magnetic damping. Although the pulse duration is short compared to the precession period, the time needed for the relaxation of the magnetization to the equilibrium state is rather large. The influence of the different magnetic anisotropy contributions and the magnetic damping parameter enters into the magnetization reversal process. Comparing the case of perpendicular anisotropy with different kinds of in-plane anisotropies, a principal difference is found due to the symmetry of the shape anisotropy with respect to the anisotropy in question

  15. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    GROSU Marian C

    2015-05-01

    Full Text Available A coated material is a composite structure that consists of at least two components: base material and coating layer. The purpose of coating is to provide special properties to base material, with potential to be applied in EMI shielding and diverse smart technical fields. This paper reports the results of a study about some physical and magnetic properties of coated woven fabrics made from cotton yarns with fineness of 17 metric count. For this aim, a plain woven fabric was coated with a solution hard magnetic polymer based. As hard magnetic powder, barium hexaferrite (BaFe12O19 was selected. The plain woven fabric used as base has been coated with five solutions having different amounts of hard magnetic powder (15% - 45% in order to obtain five different magnetic woven fabrics. A comparison of physical properties regarding weight (g/m2, thickness (mm, degree of charging (% and magnetic properties of magnetic woven samples were presented. Saturation magnetizing (emu/g, residual magnetizing (emu/g and coercive force (kA/m of pure hard magnetic powder and woven fabrics have been studied as hysteresis characteristics. The magnetic properties of the woven fabrics depend on the mass percentage of magnetic powder from coating solution. Also, the residual magnetism and coercive field of woven fabrics represents only a part of bulk barium hexafferite residual magnetism and coercive field.

  16. Magnet innovations for linacs

    International Nuclear Information System (INIS)

    Halbach, K.

    1986-01-01

    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 of past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs are presented

  17. Magnet innovations for linacs

    International Nuclear Information System (INIS)

    Halbach, K.

    1986-06-01

    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

  18. Magnetic guns with cylindrical permanent magnets

    DEFF Research Database (Denmark)

    Vokoun, David; Beleggia, Marco; Heller, Luděk

    2012-01-01

    The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative...... of the magnetostatic interaction energy. For comparison, the forces involved are also calculated numerically using finite elements methods. Based on the conservation of the magnetostatic and kinetic energies, the exit and asymptotic velocities are determined. The derived formulas can be used to optimize the generated...... forces and motion of the inner cylindrical magnet....

  19. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

  20. Magnetic nanocomposite sensor

    KAUST Repository

    Alfadhel, Ahmed; Li, Bodong; Kosel, Jü rgen

    2016-01-01

    A magnetic nanocomposite device is described herein for a wide range of sensing applications. The device utilizes the permanent magnetic behavior of the nanowires to allow operation without the application of an additional magnetic field

  1. Magnetism of Carbonados

    Science.gov (United States)

    Kletetschka, G.; Taylor, P. T.; Wasilewski, P. J.

    2000-01-01

    Origin of Carbonado is not clear. Magnetism of Carbonado comes from the surface, indicating contemporary formation of both the surface and magnetic carriers. The interior of carbonado is relatively free of magnetic phases.

  2. Magnetic propulsion for magnetically levitated trains

    Energy Technology Data Exchange (ETDEWEB)

    Melville, P H

    1973-12-01

    One of the main problems associated with magnetically levitated trains is the means of propulsion. A system is described whereby the repulsion from the superconducting magnets, in addition to levitating the train, can also be used to propel it.

  3. Nuclear magnetic resonance and earth magnetic field

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Nuclear magnetic resonance concerns nuclei whose spin is different from 0. These nuclei exposed to a magnetic field is comparable to a peg top spinning around its axis while being moved by a precession movement called Larmor precession. This article presents an experiment whose aim is to reveal nuclear magnetism of nuclei by observing Larmor precession phenomena due to the earth magnetic field. The earth magnetic field being too weak, it is necessary to increase the magnetization of the sample during a polarization phase. First the sample is submitted to a magnetic field B perpendicular to the earth magnetic field B 0 , then B is cut off and the nuclei move back to their equilibrium position by executing a precession movement due to B 0 field. (A.C.)

  4. Magnetic guns with cylindrical permanent magnets

    Czech Academy of Sciences Publication Activity Database

    Vokoun, David; Beleggia, M.; Heller, Luděk

    2012-01-01

    Roč. 324, č. 9 (2012), s. 1715-1719 ISSN 0304-8853 R&D Projects: GA ČR(CZ) GAP107/11/0391; GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : permanent magnet * cylindrical magnet * Earnshaw's theorem * magnetic gun * magnetostatic interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.826, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304885311008997

  5. Magnetic Field Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...

  6. Developing bulk exchange spring magnets

    Science.gov (United States)

    Mccall, Scott K.; Kuntz, Joshua D.

    2017-06-27

    A method of making a bulk exchange spring magnet by providing a magnetically soft material, providing a hard magnetic material, and producing a composite of said magnetically soft material and said hard magnetic material to make the bulk exchange spring magnet. The step of producing a composite of magnetically soft material and hard magnetic material is accomplished by electrophoretic deposition of the magnetically soft material and the hard magnetic material to make the bulk exchange spring magnet.

  7. Magnetic resonance of low dimensional magnetic solids

    Energy Technology Data Exchange (ETDEWEB)

    Gatteschi, D.; Ferraro, F.; Sessoli, R. (Florence Univ. (Italy))

    1994-06-01

    The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs.

  8. Magnetic resonance of low dimensional magnetic solids

    International Nuclear Information System (INIS)

    Gatteschi, D.; Ferraro, F.; Sessoli, R.

    1994-01-01

    The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs

  9. Magnetic Barkhausen noise at different magnetization conditions

    Czech Academy of Sciences Publication Activity Database

    Stupakov, Alexandr; Perevertov, Oleksiy; Neslušan, M.

    2015-01-01

    Roč. 66, č. 7 (2015), s. 10-13 ISSN 1335-3632 R&D Projects: GA ČR GA13-18993S Institutional support: RVO:68378271 Keywords : Barkhausen noise * surface magnetic field * magnetization control * magnetic hysteresis * digital feedback loop Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 0.407, year: 2015

  10. Integrated magnetic transformer assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an integrated magnetics transformer assembly comprising a first magnetically permeable core forming a first substantially closed magnetic flux path and a second magnetically permeable core forming a second substantially closed magnetic flux path. A first input...... inductor winding is wound around a first predetermined segment of the first magnetically permeable core and a second input inductor winding is wound around a first predetermined segment of the second magnetically permeable core. The integrated magnetics transformer assembly further comprises a first output......-winding of the first output inductor winding and the first half-winding of the second output inductor winding are configured to produce aligned, i.e. in the same direction, magnetic fluxes through the first substantially closed magnetic flux path. The integrated magnetics transformer assembly is well- suited for use...

  11. MAGNETIC DENSITOMETER

    Science.gov (United States)

    McCann, J.A.; Jones, R.H.

    1961-08-15

    A magnetic densitometer for locating defects and metallic inclusions in materials is described. The apparatus consists of two primary coils connected in series opposition and adapted te be placed in inductive relation to the material under test, a source of constant frequency alternating current coupled across the primary coil combination, a pick-up coil disposed in symmetrical inductive relationship with said primary coils, a phase-shifter coupled to the output of the energizing source. The output of the phase-shifter is coupled in series with the pick-up coil. An amplifier is provided selective to the third harmonic of the energizing source frequency. The series combination of the pick-up coil and the phase-shifter output are connected across the input of the amplifier, and an amplitude comparitor is coupled to the output of the amplifier and the energizing source for comparing the instantaneous amplitude of the amplifier output and the instantaneous output of the energizing source and producing an output proportional to the difference in amplitude. A recorder is coupled to the output of the amplitude comparison means to give an indication of the amplitude difference, thereby providing a permanent presentation of the character of the changes in characteristics exhibited by the material under test. (AEC)

  12. Hoosier Magnetics

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-09-30

    Hoosier Magnetics proposes to replace the indirect clinker water cooling system with a cooling system that recycles heat from the hot ferrite to preheat the combustion air. This innovative process would significantly reduce the amount of natural gas required to heat the combustion air while eliminating Hoosier’s largest source of downtime. According to the Department of Energy’s Industrial Technologies Program for Energy Efficiency and Renewable Energy, process temperature is customarily used as a rough indication of where preheating air will be cost effective. Previous studies have concluded that processes operating above 1,600° F are ideal candidates for the utilization of pre-heated combustion air. Hoosier Magnetics’ operating temperatures run between 1800-2200° F making Hoosier the perfect candidate. Using preheated air at 1200° F will result in 35% fuel savings, or $298,935 annually. Additionally, the new system would have improved process reliability and result in both production efficiency increases and cost savings. This technology is NOT practiced or utilized on a wide-spread basis but could have a significant energy reduction impact in many different high heat utilizing industries in the country. While the energy savings is apparent with this theory the application and design of such a process has not been studied.

  13. Environmental magnetism

    CERN Document Server

    Thompson, Roy

    1986-01-01

    The scientist will be forced, in the unenthusiastic words of one of my scientific colleagues, 'to slosh about in the primordial ooze known as inter-disciplinary studies'. John Passmore Man's responsibility for nature The present text has arisen from some thirteen years advances in our perception, appraisal and creative use of collaboration between the two authors. During that of order in natural systems. Out of this can come period, upwards of a dozen postgraduates in enhanced insight into processes, structures and Edinburgh, the New University of Ulster and Liver­ systems interactions on all temporal and spatial scales pool have been closely involved in exploring many of and at all integrative levels from subatomic to cosmic. the applications of magnetic measurements described In the environment, elements of order are often in the second half of the book. Much of the text is difficult to appraise and analyse, not only because of based on their work, both published and unpublished. intrinsic complexity, but ...

  14. Magnetic domains the analysis of magnetic microstructures

    CERN Document Server

    Hubert, Alex

    1998-01-01

    The book gives a systematic and comprehensive survey of the complete area of magnetic microstructures. It reaches from micromagnetism of nanoparticles to complex structures of extended magnetic materials. The book starts with a comprehensive evaluation of traditional and modern experimental methods for the observation of magnetic domains and continues with the treatment of important methods for the theoretical analysis of magnetic microcstructures. A survey of the necessary techniques in materials characterization is given. The book offers an observation and analysis of magnetic domains in all

  15. Transient anisotropic magnetic field calculation

    International Nuclear Information System (INIS)

    Jesenik, Marko; Gorican, Viktor; Trlep, Mladen; Hamler, Anton; Stumberger, Bojan

    2006-01-01

    For anisotropic magnetic material, nonlinear magnetic characteristics of the material are described with magnetization curves for different magnetization directions. The paper presents transient finite element calculation of the magnetic field in the anisotropic magnetic material based on the measured magnetization curves for different magnetization directions. For the verification of the calculation method some results of the calculation are compared with the measurement

  16. Laced permanent magnet quadrupole drift tube magnets

    International Nuclear Information System (INIS)

    Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

    1988-10-01

    A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs

  17. Designing magnets with prescribed magnetic fields

    International Nuclear Information System (INIS)

    Liu Liping

    2011-01-01

    We present a novel design method capable of finding the magnetization densities that generate prescribed magnetic fields. The method is based on the solution to a simple variational inequality and the resulting designs have simple piecewise-constant magnetization densities. By this method, we obtain new designs of magnets that generate commonly used magnetic fields: uniform magnetic fields, self-shielding fields, quadrupole fields and sextupole fields. Further, it is worth noting that this method is not limited to the presented examples, and in particular, three-dimensional designs can be constructed in a similar manner. In conclusion, this novel design method is anticipated to have broad applications where specific magnetic fields are important for the performance of the devices.

  18. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    Energy Technology Data Exchange (ETDEWEB)

    Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

    2012-09-15

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

  19. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    International Nuclear Information System (INIS)

    Vasilevskaya, Tatiana M.; Sementsov, Dmitriy I.; Shutyi, Anatoliy M.

    2012-01-01

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: ► An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. ► Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. ► Both regular and chaotic precession modes are realized within bifurcation resonance range. ► Appearance of dynamic bistability is typical for bifurcation resonance.

  20. Micro magnetic modeling of magnetization reversal in permanent magnets

    International Nuclear Information System (INIS)

    Toussaint, J.C.; Kevorkian, B.; Givord, D.; Rossignol, M.F.

    1996-01-01

    Micro magnetic numerical 3 D calculation is presented in this paper to investigate the effect of a soft magnetic heterogeneity on the magnetization reversal of a single hard magnetic grain. Both equilibrium and transient magnetization configurations are obtained by solving the dynamic Landau-Lifshitz-Gilbert (L.L.G.) equation. A modified forward difference method is used to integrate the time dependent L.L.G. equation without conflicting with the constraint of constant magnetic moment. A continuum view of the material medium is adopted and the spatial finite difference method is used to describe the system as a set of cubic elements. In each element the magnetization is interpolated with quadratic polynomial functions and constrained to follow the Brown condition at the surface. A multigrid approach is developed to calculate the magnetic potential and the resulting stray field associated with a given microstructure. The calculated properties are compared to actual properties of Nd Fe B sintered magnets. Assuming a soft nucleus of 160 angstrom diameter and 80 angstrom depth, the calculated coercive field is about 1.45 T, close to experimental values and the calculated angular dependence of H c resembles experimental behaviours. (author)

  1. Magnetic confinement

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)

    2005-07-01

    The Frascati Tokamak Upgrade (FTU) is a compact, high-magnetic-field tokamak capable of operating at density and magnetic field values similar to, or even encompassing, those of International Thermonuclear Experimental Reactor (ITER) and therefore provides a unique opportunity to explore physics issues that are directly relevant to ITER. During 2004 the experimental activities were focussed on fully exploiting the lower hybrid system (for generating and controlling the plasma current) and the electron cyclotron heating system (joint experiment with the Institute of Plasma Physics of the National Research Council, Milan). With all four gyrotrons in operation, full electron cyclotron power was achieved up to a record level of 1.5 MW. By simultaneously injecting lower hybrid waves, to tailor the plasma current radial profile, and electron cyclotron waves, to heat the plasma centre, good confinement regimes with internal transport barriers were obtained at the highest plasma density values ever achieved for this operation regime (n {approx}1.5X10{sup 20}m{sup -3}). Specific studies were devoted to optimising the coupling of lower hybrid waves to the plasma (by real-time control of the plasma position) and to generating current by electron cyclotron current drive. The new scanning CO{sub 2} interferometer (developed by the Reversed Field Experiment Consortium) for high spatial and time resolution (1 cm/50 {mu}s) density profile measurements was extensively used. The Thomson scattering diagnostic was upgraded and enabled observation of scattered signals associated with the Confinement background plasma dynamics. As for theoretical studies on the dynamics of turbulence in plasmas, the transition from Bohm-like scaling to gyro-Bohm scaling of the local plasma diffusivity was demonstrated on the basis of a generalised four wave model (joint collaboration with Princeton Plasma Physics Laboratory and the University of California at Irvine). The transition from weak to strong

  2. Magnetic confinement

    International Nuclear Information System (INIS)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo

    2005-01-01

    The Frascati Tokamak Upgrade (FTU) is a compact, high-magnetic-field tokamak capable of operating at density and magnetic field values similar to, or even encompassing, those of International Thermonuclear Experimental Reactor (ITER) and therefore provides a unique opportunity to explore physics issues that are directly relevant to ITER. During 2004 the experimental activities were focussed on fully exploiting the lower hybrid system (for generating and controlling the plasma current) and the electron cyclotron heating system (joint experiment with the Institute of Plasma Physics of the National Research Council, Milan). With all four gyrotrons in operation, full electron cyclotron power was achieved up to a record level of 1.5 MW. By simultaneously injecting lower hybrid waves, to tailor the plasma current radial profile, and electron cyclotron waves, to heat the plasma centre, good confinement regimes with internal transport barriers were obtained at the highest plasma density values ever achieved for this operation regime (n ∼1.5X10 20 m -3 ). Specific studies were devoted to optimising the coupling of lower hybrid waves to the plasma (by real-time control of the plasma position) and to generating current by electron cyclotron current drive. The new scanning CO 2 interferometer (developed by the Reversed Field Experiment Consortium) for high spatial and time resolution (1 cm/50 μs) density profile measurements was extensively used. The Thomson scattering diagnostic was upgraded and enabled observation of scattered signals associated with the Confinement background plasma dynamics. As for theoretical studies on the dynamics of turbulence in plasmas, the transition from Bohm-like scaling to gyro-Bohm scaling of the local plasma diffusivity was demonstrated on the basis of a generalised four wave model (joint collaboration with Princeton Plasma Physics Laboratory and the University of California at Irvine). The transition from weak to strong energetic particle

  3. Magnetic-flux pump

    Science.gov (United States)

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A magnetic flux pump is described for increasing the intensity of a magnetic field by transferring flux from one location to the magnetic field. The device includes a pair of communicating cavities formed in a block of superconducting material, and a piston for displacing the trapped magnetic flux into the secondary cavity producing a field having an intense flux density.

  4. Superconducting magnets 1992

    International Nuclear Information System (INIS)

    1993-06-01

    This report discusses the following topics on Superconducting Magnets; SSC Magnet Industrialization; Collider Quadrupole Development; A Record-Setting Magnet; D20: The Push Beyond 10T; Nonaccelerator Applications; APC Materials Development; High-T c at Low Temperature; Cable and Cabling-Machine Development; and Analytical Magnet Design

  5. Magnetic multilayer structure

    Science.gov (United States)

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  6. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1985-02-01

    The basic properties of the Hamiltonian representation of magnetic fields in canonical form are reviewed. The theory of canonical magnetic perturbation theory is then developed and applied to the time evolution of a magnetic field embedded in a toroidal plasma. Finally, the extension of the energy principle to tearing modes, utilizing the magnetic field line Hamiltonian, is outlined

  7. Magnetic effects in electrochemistry

    Directory of Open Access Journals (Sweden)

    NEBOJSA D. NIKOLIC

    2005-05-01

    Full Text Available The effect of imposed magnetic fields onto the electrodeposition of magnetic (nickel and non – magnetic (copper metals was analysed. Also, magnetic properties of electrochemically obtained nanocontacts were examined. An effort to establish a possible correlation between the morphologies of the nanocontacts and the effect of the very large ballistic magnetoresistance (BMR effect was made.

  8. Introduction to permanent magnets

    International Nuclear Information System (INIS)

    Zijlstra, H.

    1985-01-01

    Some general considerations concerning the application of permanent magnets are developed. The relevant magnet properties are discussed, with particular reference to Nd-Fe-B alloy. The author comes to the following conclusions; the air gap field B should be high, for high electrical efficiency; the magnet should face the air gap, for efficient use of the magnet material; the magnet material should therefore have a high remanence; and the new Nd-Fe-B magnet fits in nicely, having (potentially) the highest remanence ever reported in permanent magnets, combined with sufficient coercivity to sustain it

  9. SLC kicker magnet limitations

    International Nuclear Information System (INIS)

    Cassel, R.; Donaldson, A.; Mattison, T.; Bowden, G.; Weaver, J.; Bulos, F.; Fiander, D.

    1991-01-01

    The SLC Damping Ring kicker magnets requires a fast magnetic field rise time of 58 nsec, a peak field of 800 gauss, a pulse amplitude stability of 0.01%, and a reasonable operational lifetime. The original kicker magnets designed by SLAC and at Fermi were not able to fulfill the SLC kicker requirements. Extensive studies were conducted to determine the limitation in the magnets, response of the ferrite in kicker magnet, and the modifications needed to improve the kicker magnet performance. The paper details the SLAC and Fermi kicker magnets limitation of performance

  10. Hybrid superconducting magnetic suspensions

    International Nuclear Information System (INIS)

    Tixador, P.; Hiebel, P.; Brunet, Y.; Chaud, X.; Gautier-Picard, P.

    1996-01-01

    Superconductors, especially high T c ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO

  11. High gradient magnetic separation

    International Nuclear Information System (INIS)

    Prothero, D.H.

    1982-01-01

    In a process in which magnetic material is trapped in a filter disposed in a magnetic field, and is unloaded by passing a fluid through the filter in the absence of the initial magnetic field, the magnetic field is first reduced to an intermediate value to allow unloading of the more weakly magnetic particles, the more strongly magnetic particles being retained and subsequently unloaded by further reduction of the magnetic field. Stage by stage reduction of the magnetic field during unloading allows separation of different species from the mixture. As an example the method can be applied to the separation of uranium compounds from mine ores. The uranium compounds are magnetic, while most of the other constituents of the ore are non-magnetic. The starting material is a suspension of the ore. Water is used for unloading. The filter material in this case is stainless steel balls. (author)

  12. Neutron scattering and magnetism

    International Nuclear Information System (INIS)

    Mackintosh, A.R.

    1983-01-01

    Those properties of the neutron which make it a unique tool for the study of magnetism are described. The scattering of neutrons by magnetic solids is briefly reviewed, with emphasis on the information on the magnetic structure and dynamics which is inherent in the scattering cross-section. The contribution of neutron scattering to our understanding of magnetic ordering, excitations and phase transitions is illustrated by experimental results on a variety of magnetic crystals. (author)

  13. Ultrafast magnetization dynamics

    OpenAIRE

    Woodford, Simon

    2008-01-01

    This thesis addresses ultrafast magnetization dynamics from a theoretical perspective. The manipulation of magnetization using the inverse Faraday effect has been studied, as well as magnetic relaxation processes in quantum dots. The inverse Faraday effect – the generation of a magnetic field by nonresonant, circularly polarized light – offers the possibility to control and reverse magnetization on a timescale of a few hundred femtoseconds. This is important both for the technological advant...

  14. Stacked magnet superconducting bearing

    International Nuclear Information System (INIS)

    Rigney, T.K. II; Saville, M.P.

    1993-01-01

    A superconducting bearing is described, comprising: a plurality of permanent magnets magnetized end-to-end and stacked side-by-side in alternating polarity, such that flux lines flow between ends of adjacent magnets; isolating means, disposed between said adjacent magnets, for reducing flux leakage between opposing sides of said adjacent magnets; and a member made of superconducting material having at least one surface in communication with said flux lines

  15. Magnetic Damping For Maglev

    Directory of Open Access Journals (Sweden)

    S. Zhu

    1998-01-01

    Full Text Available Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.

  16. Magnetically operated check valve

    Science.gov (United States)

    Morris, Brian G.; Bozeman, Richard J., Jr.

    1994-06-01

    A magnetically operated check valve is disclosed. The valve is comprised of a valve body and a movable poppet disposed therein. A magnet attracts the poppet to hold the valve shut until the force of fluid flow through the valve overcomes the magnetic attraction and moves the poppet to an unseated, open position. The poppet and magnet are configured and disposed to trap a magnetically attracted particulate and prevent it from flowing to a valve seating region.

  17. Magnetic novae

    Science.gov (United States)

    Zemko, Polina; Orio, Marina

    2016-07-01

    We present the results of optical and X-ray observations of two quiescent novae, V2491 Cyg and V4743 Sgr. Our observations suggest the intriguing possibility of localization of hydrogen burning in magnetic novae, in which accretion is streamed to the polar caps. V2491 Cyg was observed with Suzaku more than 2 years after the outburst and V4743 Sgr was observed with XMM Newton 2 and 3.5 years after maximum. In the framework of a monitoring program of novae previously observed as super soft X-ray sources we also obtained optical spectra of V4743 Sgr with the SALT telescope 11.5 years after the eruption and of V2491 Cyg with the 6m Big Azimutal Telescope 4 and 7 years post-outburst. In order to confirm the possible white dwarf spin period of V2491 Cyg measured in the Suzaku observations we obtained photometric data using the 90cm WIYN telescope at Kitt Peak and the 1.2 m telescope in Crimea. We found that V4743 Sgr is an intermediate polar (IP) and V2491 Cyg is a strong IP candidate. Both novae show modulation of their X-ray light curves and have X-ray spectra typical of IPs. The Suzaku and XMM Newton exposures revealed that the spectra of both novae have a very soft blackbody-like component with a temperature close to that of the hydrogen burning white dwarfs in their SSS phases, but with flux by at least two orders of magnitude lower, implying a possible shrinking of emitting regions in the thin atmosphere that is heated by nuclear burning underneath it. In quiescent IPs, independently of the burning, an ultrasoft X-ray flux component originates at times in the polar regions irradiated by the accretion column, but the soft component of V4743 Sgr disappeared in 2006, indicating that the origin may be different from accretion. We suggest it may have been due to an atmospheric temperature gradient on the white dwarf surface, or to continuing localized thermonuclear burning at the bottom of the envelope, before complete turn-off. The optical spectra of V2491 Cyg and V

  18. Intrinsic magnetic torque at low magnetic induction

    International Nuclear Information System (INIS)

    Doria, M.M.; Oliveira, I.G. de.

    1993-01-01

    Using anisotropic London theory the intrinsic magnetic torque for extreme type II uniaxial superconductors for any value of the magnetic induction is obtained. It is considered the vortex lines straight and take into account the contribution of the supercurrents flowing inside the vortex core within the London theory. It is shown that the interline and intra line free energies give opposite torque contributions, the first drives the magnetic induction parallel to the superconductor's axis of symmetry and the second orthogonal to it. At high magnetic induction torque expression obtained generalizes V. Kogan's formula since it has no free parameters other than the anisotropy γ = m 1 /m 3 and the Ginzburg-Landau parameter κ. At low magnetic induction it is proposed a way to observe vortex chains effects in the total torque based on the fact that London theory is linear and the energy to make a single vortex line in space is independent of the magnetic induction. (author)

  19. Magnetization of Paraffin-Based Magnetic Nanocolloids

    Science.gov (United States)

    Dikanskii, Yu. I.; Ispiryan, A. G.; Kunikin, S. A.; Radionov, A. V.

    2018-01-01

    Using paraffin-based magnetic nanocolloids as an example, the reasons for maxima in the temperature dependence of the magnetic susceptibility of magnetic colloids have been discussed. The behavior of these dependences in a wide temperature interval has been analyzed for colloids in solid and liquid states. It has been concluded that the maximum observed at the melting point of paraffin can be attributed to freezing Brownian degrees of freedom in magnetite coarse particles, the magnetic moment of which is intimately related to the solid matrix. The second main maximum, which arises in the solid state, is explained by the superparamagnetic-magnetically hard transition of most fine particles at lower temperatures. It has been noted that the flatness of this maximum results from the polydispersity of the magnetic nanoparticle ensemble.

  20. Manufacturing methods and magnetic characteristics of magnetic wood

    International Nuclear Information System (INIS)

    Oka, H.; Hojo, A.; Osada, H.; Namizaki, Y.; Taniuchi, H.

    2004-01-01

    The relationship between wood construction and DC magnetic characteristics for three types of magnetic wood was experimentally investigated. The results show that the magnetic characteristics of each type of magnetic wood are dependent on the magnetic materials, the density of the magnetic material and the construction of the wood. Furthermore, it was determined that the relationship between the fiber direction and the magnetic path direction of the magnetic wood influenced the wood's magnetic characteristics

  1. Magnetization effects in superconducting dipole magnets

    International Nuclear Information System (INIS)

    Ishimoto, H.; Peters, R.E.; Price, M.E.; Yamada, R.

    1977-01-01

    Magnetization effect of superconductors on the field quality was investigated for some of the typical Energy Doubler bending magnets. Calculations were made using the computor program GFUN2D and compared with some measured results. Agreement between them is good. The field quality at low excitation is mainly determined by the magnetization effect. A similar effect due to a stainless collar mechanical support was also calculated, although it is not as big as the first one

  2. Magnetic field modification of optical magnetic dipoles.

    Science.gov (United States)

    Armelles, Gaspar; Caballero, Blanca; Cebollada, Alfonso; Garcia-Martin, Antonio; Meneses-Rodríguez, David

    2015-03-11

    Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate.

  3. Magnetic design of a FFAG superconducting magnet

    International Nuclear Information System (INIS)

    Obana, T.; Ogitsu, T.; Nakamoto, T.; Sasaki, K.; Yamamoto, A.; Yoshimoto, M.; Mori, Y.; Orikasa, T.

    2005-01-01

    A superconducting magnet for a Fixed Field Alternating Gradient (FFAG) accelerator has been proposed. The required magnetic field is static and proportional to the k-th power of the orbit radius where k is the geometrical field index of the accelerator. In 2D, the required magnetic field can be generated with the optimized cross section of the coil. The cross section of the coils is a left-right asymmetry to simplify the cross section and ellipse to downsize the magnet. Local and integral 3D fields along the beam trajectory are evaluated with using new type of 3D coil configuration

  4. Magnetization reversal in single molecule magnets

    Science.gov (United States)

    Bokacheva, Louisa

    2002-09-01

    I have studied the magnetization reversal in single molecule magnets (SMMs). SMMs are Van der Waals crystals, consisting of identical molecules containing transition metal ions, with high spin and large uniaxial magnetic anisotropy. They can be considered as ensembles of identical, iso-oriented nanomagnets. At high temperature, these materials behave as superparamagnets and their magnetization reversal occurs by thermal activation. At low temperature they become blocked, and their magnetic relaxation occurs via thermally assisted tunneling or pure quantum tunneling through the anisotropy barrier. We have conducted detailed experimental studies of the magnetization reversal in SMM material Mn12-acetate (Mn12) with S = 10. Low temperature measurements were conducted using micro-Hall effect magnetometry. We performed hysteresis and relaxation studies as a function of temperature, transverse field, and magnetization state of the sample. We identified magnetic sublevels that dominate the tunneling at a given field, temperature and magnetization. We observed a crossover between thermally assisted and pure quantum tunneling. The form of this crossover depends on the magnitude and direction of the applied field. This crossover is abrupt (first-order) and occurs in a narrow temperature interval (tunneling mechanisms in Mn12.

  5. Computational quantum magnetism: Role of noncollinear magnetism

    International Nuclear Information System (INIS)

    Freeman, Arthur J.; Nakamura, Kohji

    2009-01-01

    We are witnessing today a golden age of innovation with novel magnetic materials and with discoveries important for both basic science and device applications. Computation and simulation have played a key role in the dramatic advances of the past and those we are witnessing today. A goal-driving computational science-simulations of every-increasing complexity of more and more realistic models has been brought into greater focus with greater computing power to run sophisticated and powerful software codes like our highly precise full-potential linearized augmented plane wave (FLAPW) method. Indeed, significant progress has been achieved from advanced first-principles FLAPW calculations for the predictions of surface/interface magnetism. One recently resolved challenging issue is the role of noncollinear magnetism (NCM) that arises not only through the SOC, but also from the breaking of symmetry at surfaces and interfaces. For this, we will further review some specific advances we are witnessing today, including complex magnetic phenomena from noncollinear magnetism with no shape approximation for the magnetization (perpendicular MCA in transition-metal overlayers and superlattices; unidirectional anisotropy and exchange bias in FM and AFM bilayers; constricted domain walls important in quantum spin interfaces; and curling magnetic nano-scale dots as new candidates for non-volatile memory applications) and most recently providing new predictions and understanding of magnetism in novel materials such as magnetic semiconductors and multi-ferroic systems

  6. Advanced Magnetic Nanostructures

    CERN Document Server

    Sellmyer, David

    2006-01-01

    Advanced Magnetic Nanostructures is devoted to the fabrication, characterization, experimental investigation, theoretical understanding, and utilization of advanced magnetic nanostructures. Focus is on various types of 'bottom-up' and 'top-down' artificial nanostructures, as contrasted to naturally occurring magnetic nanostructures, such as iron-oxide inclusions in magnetic rocks, and to structures such as perfect thin films. Chapter 1 is an introduction into some basic concepts, such as the definitions of basic magnetic quantities. Chapters 2-4 are devoted to the theory of magnetic nanostructures, Chapter 5 deals with the characterization of the structures, and Chapters 6-10 are devoted to specific systems. Applications of advanced magnetic nanostructures are discussed in Chapters11-15 and, finally, the appendix lists and briefly discusses magnetic properties of typical starting materials. Industrial and academic researchers in magnetism and related areas such as nanotechnology, materials science, and theore...

  7. The magnet database system

    International Nuclear Information System (INIS)

    Baggett, P.; Delagi, N.; Leedy, R.; Marshall, W.; Robinson, S.L.; Tompkins, J.C.

    1991-01-01

    This paper describes the current status of MagCom, a central database of SSC magnet information that is available to all magnet scientists via network connections. The database has been designed to contain the specifications and measured values of important properties for major materials, plus configuration information (specifying which individual items were used in each cable, coil, and magnet) and the test results on completed magnets. These data will help magnet scientists to track and control the production process and to correlate the performance of magnets with the properties of their constituents

  8. AGS superconducting bending magnets

    International Nuclear Information System (INIS)

    Robins, K.E.; Sampson, W.B.; McInturff, A.D.; Dahl, P.F.; Abbatiello, F.; Aggus, J.; Bamberger, J.; Brown, D.; Damm, R.; Kassner, D.; Lasky, C.; Schlafke, A.

    1976-01-01

    Four large aperture superconducting bending magnets are being built for use in the experimental beams at the AGS. Each of these magnets is 2.5 m long and has a room temperature aperture of 20 cm. The magnets are similar in design to the dipoles being developed for ISABELLE and employ a low temperature iron core. Results are presented on the ''training'' behavior of the magnets and a comparison will be made with the smaller aperture versions of this design. The magnet field measurements include end fields and leakage fields as well as the harmonic components of the straight section of the magnet

  9. Magnet and device for magnetic density separation

    NARCIS (Netherlands)

    Polinder, H.; Rem, P.C.

    2014-01-01

    A planar magnet for magnetic density separation, comprising an array of pole pieces succeeding in longitudinal direction of a mounting plane, each pole piece having a body extending transversely along the mounting plane with a substantially constant cross section that includes a top segment that is

  10. Magnetic properties of diluted magnetic semiconductors

    NARCIS (Netherlands)

    Jonge, de W.J.M.; Swagten, H.J.M.

    1991-01-01

    A review will be given of the magnetic characteristics of diluted magnetic semiconductors and the relation with the driving exchange mechanisms. II–VI as well as IV–VI compounds will be considered. The relevance of the long-range interaction and the role of the carrier concentration will be

  11. Magnetically modified biocells in constant magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, E.G.; Panina, L.K. [Saint Petersburg State University, St. Petersburg (Russian Federation); Kolikov, V.A., E-mail: kolikov1@yandex.ru [Institute for Electrophysics and Electric Power of the RAS, St. Petersburg (Russian Federation); Bogomolova, E.V. [Botanical Institute of the RAS after V.L.Komarov, St. Petersburg (Russian Federation); Snetov, V.N. [Institute for Electrophysics and Electric Power of the RAS, St. Petersburg (Russian Federation); Cherepkova, I.A. [Saint Petersburg State Institute of Technology, St. Petersburg (Russian Federation); Kiselev, A.A. [Institute for Electrophysics and Electric Power of the RAS, St. Petersburg (Russian Federation)

    2017-02-01

    Paper addresses the inverse problem in determining the area, where the external constant magnetic field captures the biological cells modified by the magnetic nanoparticles. Zero velocity isolines, in area where the modified cells are captured by the magnetic field were determined by numerical method for two locations of the magnet. The problem was solved taking into account the gravitational field, magnetic induction, density of medium, concentration and size of cells, and size and magnetization of nanoparticles attached to the cell. Increase in the number of the nanoparticles attached to the cell and decrease in the cell’ size, enlarges the area, where the modified cells are captured and concentrated by the magnet. Solution is confirmed by the visible pattern formation of the modified cells Saccharomyces cerevisiae. - Highlights: • The inverse problem was solved for finding zero velocity isolines of magnetically modified biological cells. • Solution of the inverse problem depends on the size of cells and the number of nanoparticles attached to the single cell. • The experimental data are in agreement with theoretical solution.

  12. Active Magnetic Bearings – Magnetic Forces

    DEFF Research Database (Denmark)

    Kjølhede, Klaus

    2006-01-01

    Parameter identification procedures and model validation are major steps towards intelligent machines supported by active magnetic bearings (AMB). The ability of measuring the electromagnetic bearing forces, or deriving them from measuring the magnetic flux, strongly contributes to the model...... of the work is the characterization of magnetic forces by using two experimental different experimental approaches. Such approaches are investigated and described in details. A special test rig is designed where the 4 poles - AMB is able to generate forces up to 1900 N. The high precision characterization...... of the magnetic forces are led by using different experimental tests: (I) by using hall sensors mounted directly on the poles (precise measurements of the magnetic flux) and by an auxiliary system, composed of strain gages and flexible beams attached to the rotor; (II) by measuring the input current and bearing...

  13. Magnetization reversal mechanisms under oblique magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Ntallis, N.; Efthimiadis, K.G., E-mail: kge@auth.gr

    2017-03-01

    In this work finite element micromagnetic simulations were performed in order to study the reversal mechanisms of spherical ferromagnetic particles with uniaxial magnetocrystalline anisotropy, when they are magnetized along an oblique direction with respect to the anisotropy axis. Magnetization loops are taken in different directions of external magnetic field, at different anisotropy constants and particle sizes. In the simulation results, the three reversal mechanisms (coherent, curling and domains) are observed and new phenomena arise due to the action of oblique magnetic fields. Moreover, the dependence of the critical fields with respect to the angle of the external field is presented. - Highlights: • Finite element micromagnetic simulation of the three different reversal mechanisms. • For the curling mechanism, the new phenomenon is the rotation of the vortex. • In the domain reversal mechanism, the formed domain wall is smaller than 180°. • In soft ferromagnetic particles a rearrangement of the magnetic domains is observed.

  14. Single molecule magnets from magnetic building blocks

    Science.gov (United States)

    Kroener, W.; Paretzki, A.; Cervetti, C.; Hohloch, S.; Rauschenbach, S.; Kern, K.; Dressel, M.; Bogani, L.; M&üLler, P.

    2013-03-01

    We provide a basic set of magnetic building blocks that can be rationally assembled, similar to magnetic LEGO bricks, in order to create a huge variety of magnetic behavior. Using rare-earth centers and multipyridine ligands, fine-tuning of intra and intermolecular exchange interaction is demonstrated. We have investigated a series of molecules with monomeric, dimeric and trimeric lanthanide centers using SQUID susceptometry and Hall bar magnetometry. A home-made micro-Hall-probe magnetometer was used to measure magnetic hysteresis loops at mK temperatures and fields up to 17 T. All compounds show hysteresis below blocking temperatures of 3 to 4 K. The correlation of the assembly of the building blocks with the magnetic properties will be discussed.

  15. Magnetic shielding for MRI superconducting magnets

    International Nuclear Information System (INIS)

    Ishiyama, A.; Hirooka, H.

    1991-01-01

    This paper describes an optimal design of a highly homogeneous superconducting coil system with magnetic shielding for Magnetic Resonance Imaging (MRI). The presented optimal design method; which is originally proposed in our earlier papers, is a combination of the hybrid finite element and boundary element method for analysis of an axially symmetric nonlinear open boundary magnetic field problem, and the mathematical programming method for solving the corresponding optimization problem. In this paper, the multi-objective goal programming method and the nonlinear least squares method have been adopted. The optimal design results of 1.5- and 4.7-Tesla-magnet systems with different types of magnetic shielding for whole-body imaging are compared and the advantages of a combination of active and yoke shields are shown

  16. Magnetic Resonance Imaging

    Science.gov (United States)

    ... Permanent cosmetics or tattoos Dentures/teeth with magnetic keepers Other implants that involve magnets Medication patch (i. ... or longer. You’ll be told ahead of time just how long your scan is expected to ...

  17. An integrated magnetics component

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an integrated magnetics component comprising a magnetically permeable core comprising a base member extending in a horizontal plane and first, second, third and fourth legs protruding substantially perpendicularly from the base member. First, second, third...... and fourth output inductor windings are wound around the first, second, third and fourth legs, respectively. A first input conductor of the integrated magnetics component has a first conductor axis and extends in-between the first, second, third and fourth legs to induce a first magnetic flux through a first...... flux path of the magnetically permeable core. A second input conductor of the integrated magnetics component has a second coil axis extending substantially perpendicularly to the first conductor axis to induce a second magnetic flux through a second flux path of the magnetically permeable core...

  18. Magnetic Field Grid Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Properties Calculator will computes the estimated values of Earth's magnetic field(declination, inclination, vertical component, northerly...

  19. ISR magnet power supplies

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    At the left, for the main magnets, the 18 kV switchgear is in the foreground and at the rear are cubicles with rectifiers and filters. At the right, rear, are rectifiers for pole face windings and auxiliary magnets.

  20. Magnet Quench 101

    OpenAIRE

    Bottura, L.

    2014-01-01

    This paper gives a broad summary of the physical phenomena associated with the quench of a superconducting magnet. This paper gives a broad summary of the physical phenomena associated with the quench of a superconducting magnet.

  1. Big magnetoresistance: magnetic polarons

    International Nuclear Information System (INIS)

    Teresa, J.M. de; Ibarra, M.R.

    1997-01-01

    By using several macro and microscopic experimental techniques we have given evidence for magnetoresistance in manganese oxides caused by the effect of the magnetic field on the magnetic polarons. (Author) 3 refs

  2. Enhanced Magnetic Model 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Magnetic Model (EMM) extends to degree and order 720, resolving magnetic anomalies down to 56 km wavelength. The higher resolution of the EMM results in...

  3. Enhanced Magnetic Model 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Magnetic Model (EMM) extends to degree and order 720, resolving magnetic anomalies down to 56 km wavelength. The higher resolution of the EMM results in...

  4. Magnetism basics and applications

    CERN Document Server

    Stefanita, Carmen-Gabriela

    2012-01-01

    This textbook is aimed at engineering students who are likely to come across magnetics applications in their professional practice. Whether designing lithography equipment containing ferromagnetic brushes, or detecting defects in aeronautics, some basic knowledge of 21st century magnetism is needed. From the magnetic tape on the pocket credit card to the read head in a personal computer, people run into magnetism in many products. Furthermore, in a variety of disciplines tools of the trade exploit magnetic principles, and many interdisciplinary laboratory research areas cross paths with magnetic phenomena that may seem mysterious to the untrained mind. Therefore, this course offers a broad coverage of magnetism topics encountered more often in this millenium, revealing key concepts on which many practical applications rest. Some traditional subjects in magnetism are discussed in the first half of the book, followed by areas likely to spark the curiosity of those more interested in today’s technological achi...

  5. Permanent quadrupole magnets

    International Nuclear Information System (INIS)

    Bush, E.D. Jr.

    1976-01-01

    A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. (author)

  6. Magnetic fusion technology

    CERN Document Server

    Dolan, Thomas J

    2014-01-01

    Magnetic Fusion Technology describes the technologies that are required for successful development of nuclear fusion power plants using strong magnetic fields. These technologies include: ? magnet systems, ? plasma heating systems, ? control systems, ? energy conversion systems, ? advanced materials development, ? vacuum systems, ? cryogenic systems, ? plasma diagnostics, ? safety systems, and ? power plant design studies. Magnetic Fusion Technology will be useful to students and to specialists working in energy research.

  7. Supercollider: Magnet update

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-07-15

    The heart of the proposed US Superconducting Supercollider (SSC) is the set of superconducting magnets to hold its beams in orbit. Approximately 8,000 dipoles and 2,000 quadrupoles are needed, as well as many other special magnets. In addition the 2 TeV high energy booster would also be a superconducting machine, using about 1,200 magnets. In all, some 12,000 superconducting magnets would need to be precision built at the lowest possible cost.

  8. Supercollider: Magnet update

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The heart of the proposed US Superconducting Supercollider (SSC) is the set of superconducting magnets to hold its beams in orbit. Approximately 8,000 dipoles and 2,000 quadrupoles are needed, as well as many other special magnets. In addition the 2 TeV high energy booster would also be a superconducting machine, using about 1,200 magnets. In all, some 12,000 superconducting magnets would need to be precision built at the lowest possible cost

  9. Elements of magnetic switching

    International Nuclear Information System (INIS)

    Aaland, K.

    1983-01-01

    This chapter describes magnetic switching as a method of connecting a capacitor bank (source) to a load; reviews several successful applications of magnetic switching, and discusses switching transformers, limitations and future possibilities. Some of the inflexibility and especially the high cost of magnetic materials may be overcome with the availability of the new splash cooled ribbons (Metglas). Experience has shown that magnetics works despite shock, radiation or noise interferences

  10. Modular tokamak magnetic system

    International Nuclear Information System (INIS)

    Yang, T.F.

    1988-01-01

    This patent describes a tokamak reactor including a vacuum vessel, toroidal confining magnetic field coils disposed concentrically around the minor radius of the vacuum vessel, and poloidal confining magnetic field coils, an ohmic heating coil system comprising at least one magnetic coil disposed concentrically around a toroidal field coil, wherein the magnetic coil is wound around the toroidal field coil such that the ohmic heating coil enclosed the toroidal field coil

  11. Magnetic actuators and sensors

    CERN Document Server

    Brauer, John R

    2014-01-01

    An accessible, comprehensive guide on magnetic actuators and sensors, this fully updated second edition of Magnetic Actuators and Sensors includes the latest advances, numerous worked calculations, illustrations, and real-life applications. Covering magnetics, actuators, sensors, and systems, with updates of new technologies and techniques, this exemplary learning tool emphasizes computer-aided design techniques, especially magnetic finite element analysis, commonly used by today's engineers. Detailed calculations, numerous illustrations, and discussions of discrepancies make this text an inva

  12. Iron dominated magnets

    International Nuclear Information System (INIS)

    Fischer, G.E.

    1985-07-01

    These two lectures on iron dominated magnets are meant for the student of accelerator science and contain general treatments of the subjects design and construction. The material is arranged in the categories: General Concepts and Cost Considerations, Profile Configuration and Harmonics, Magnetic Measurements, a few examples of ''special magnets'' and Materials and Practices. Extensive literature is provided

  13. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  14. Noble gas magnetic resonator

    Science.gov (United States)

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2014-04-15

    Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.

  15. Magnetic modes in superlattices

    International Nuclear Information System (INIS)

    Oliveira, F.A.

    1990-04-01

    A first discussion of reciprocal propagation of magnetic modes in a superlattice is presented. In the absence of an applied external magnetic field a superllatice made of alternate layers of the type antiferromagnetic-non-magnetic materials presents effects similar to those of phonons in a dielectric superlattice. (A.C.A.S.) [pt

  16. Iron dominated magnets

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G.E.

    1985-07-01

    These two lectures on iron dominated magnets are meant for the student of accelerator science and contain general treatments of the subjects design and construction. The material is arranged in the categories: General Concepts and Cost Considerations, Profile Configuration and Harmonics, Magnetic Measurements, a few examples of ''special magnets'' and Materials and Practices. Extensive literature is provided.

  17. Pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Cohen, M.D.

    1986-01-01

    This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

  18. Color and magnetic charge

    International Nuclear Information System (INIS)

    Kim, B.R.

    1976-01-01

    Schwinger's conjecture that the color degree of freedom of a quark is equivalent to its degree of freedom of taking different magnetic charges provides a plausible motivation for extending color to leptons. Leptons are just quarks with zero magnetic charges. It is shown that baryon number and lepton number can be replaced by fermion number and magnetic charge

  19. Rare earth permanent magnets

    International Nuclear Information System (INIS)

    Higuchi, Akira

    1992-01-01

    This paper is a review of the new technologies for Nd-Fe-B magnets, their markets and future perspectives. This type of magnet is a product approaching the ideal magnet, and is based upon the development history of two previous generations of Sm-Co alloy systems and the recent progress on physical and metallurgical research. (orig.)

  20. Magnetic polarizability of pion

    Energy Technology Data Exchange (ETDEWEB)

    Luschevskaya, E.V., E-mail: luschevskaya@itep.ru [Institute for Theoretical and Experimental Physics, Bolshaia Cheremushkinskaia 25, 117218 Moscow (Russian Federation); School of Biomedicine, Far Eastern Federal University, 690950 Vladivostok (Russian Federation); Solovjeva, O.E., E-mail: olga.solovjeva@itep.ru [Institute for Theoretical and Experimental Physics, Bolshaia Cheremushkinskaia 25, 117218 Moscow (Russian Federation); Teryaev, O.V., E-mail: teryaev@theor.jinr.ru [Joint Institute for Nuclear Research, Dubna, 141980 (Russian Federation); National Research Nuclear University “MEPhI” (Moscow Engineering Physics Institute), Kashirskoe highway, 31, 115409 Moscow (Russian Federation)

    2016-10-10

    We explore the energy dependence of π mesons off the background Abelian magnetic field on the base of quenched SU(3) lattice gauge theory and calculate the magnetic dipole polarizability of charged and neutral pions for various lattice volumes and lattice spacings. The contribution of the magnetic hyperpolarizability to the neutral pion energy has been also found.

  1. Omnigenous magnetic fields

    International Nuclear Information System (INIS)

    Stupakov, G.V.

    1982-01-01

    In omnigenous magnetic fields particles' drift surfaces coincide with plasma magnetic surfaces. In this paper we formulate equations of omnigenous magnetic fields in natural curvilinear coordinates. An analysis of fields which are omnigenous only in the paraxial approximation is presented. (author)

  2. Magnetism in meteorites

    Science.gov (United States)

    Herndon, J. M.; Rowe, M. W.

    1974-01-01

    An overview is presented of magnetism in meteorites. A glossary of magnetism terminology followed by discussion of the various techniques used for magnetism studies in meteorites are included. The generalized results from use of these techniques by workers in the field are described. A brief critical analysis is offered.

  3. The Galactic magnetic fields

    International Nuclear Information System (INIS)

    Han Jinlin

    2006-01-01

    A good progress has been made on studies of Galactic magnetic fields in last 10 years. I describe what we want to know about the Galactic magnetic fields, and then review we current knowledge about magnetic fields in the Galactic disk, the Galactic halo and the field strengths. I also listed many unsolved problems on this area

  4. RF and magnets

    International Nuclear Information System (INIS)

    Hutcheon, R.M.

    1986-01-01

    Examples of how applied radiofrequency and magnet technology are used, and could be used, in the nuclear medical field are presented. Specific examples are: 1) the THERAC 25 electron accelerator project; 2) large, high field magnet systems for nuclear magnetic resonance (NMR); 3) the superconducting cyclotron; and 4. hyperthermia treatment. Emphasis is placed on the example of hyperthermia treatment

  5. The magnetic properties of the hollow cylindrical ideal remanence magnet

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

    2016-01-01

    We consider the magnetic properties of the hollow cylindrical ideal remanence magnet. This magnet is the cylindrical permanent magnet that generates a uniform field in the cylinder bore, using the least amount of magnetic energy to do so. The remanence distribution of this magnet is derived...

  6. The Juno Magnetic Field Investigation

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Benn, Mathias; Bjarnø, Jonas Bækby

    2017-01-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter’s planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor ...

  7. Cosmic Magnetic Fields

    Science.gov (United States)

    Sánchez Almeida, J.; Martínez González, M. J.

    2018-05-01

    Magnetic fields play an important role in many astrophysical processes. They are difficult to detect and characterize since often their properties have to be inferred through interpreting the polarization of the light. Magnetic fields are also challenging to model and understand. Magnetized plasmas behave following highly non-linear differential equations having no general solution, so that every astrophysical problem represents a special case to be studied independently. Hence, magnetic fields are often an inconvenient subject which is overlooked or simply neglected (the elephant in the room, as they are dubbed in poster of the school). Such difficulty burdens the research on magnetic fields, which has evolved to become a very technical subject, with many small disconnected communities studying specific aspects and details. The school tried to amend the situation by providing a unifying view of the subject. The students had a chance to understand the behavior of magnetic fields in all astrophysical contexts, from cosmology to the Sun, and from starbursts to AGNs. The school was planed to present a balanced yet complete review of our knowledge, with excursions into the unknown to point out present and future lines of research. The subject of Cosmic Magnetic Fields was split into seven different topics: cosmic magnetic field essentials, solar magnetic fields, stellar magnetic fields, the role of magnetic fields on AGN feedback, magnetic fields in galaxies, magnetic fields in galaxy clusters and at larger scales, and primordial magnetic fields and magnetic fields in the early Universe. The corresponding lectures were delivered by seven well known and experienced scientists that have played key roles in the major advances of the field during the last years: F. Cattaneo, P. Judge, O. Kochukhov, R. Keppens, R. Beck, K. Dolag, and F. Finelli. Their lectures were recorded and are freely available at the IAC website: http://iactalks.iac.es/talks/serie/19.

  8. Magnetic hyperthermia with hard-magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kashevsky, Bronislav E., E-mail: bekas@itmo.by [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Kashevsky, Sergey B.; Korenkov, Victor S. [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Istomin, Yuri P. [N. N. Alexandrov National Cancer Center of Belarus, Lesnoy-2, Minsk 223040 (Belarus); Terpinskaya, Tatyana I.; Ulashchik, Vladimir S. [Institute of Physiology, Belarus Academy of Sciences, Akademicheskaya str. 28, Minsk 220072 (Belarus)

    2015-04-15

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner–Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner–Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body. - Highlights: • Hard-magnetic nanoparticles are shown superior for hyperthetmia to superparamagnetic. • Optimal system parameters are found from magnetic reversal model in movable particle. • Penetrating suspension of HM particles with aggregation-independent SAR is developed. • For the first time, mice with tumors are healed in AC field acceptable for human body.

  9. Magnetism and metallurgy of soft magnetic materials

    CERN Document Server

    Chen, Chih-Wen

    2011-01-01

    Soft magnetic materials are economically and technologically the most important of all magnetic materials. In particular, the development of new materials and novel applications for the computer and telecommunications industries during the past few decades has immensely broadened the scope and altered the nature of soft magnetic materials. In addition to metallic substances, nonmetallic compounds and amorphous thin films are coming increasingly important. This thorough, well-organized volume - on of the most comprehensive treatments available - offers a coherent, logical presentation of the p

  10. Magnetism: a supramolecular function

    International Nuclear Information System (INIS)

    Decurtins, S.; Pellaux, R.; Schmalle, H.W.

    1996-01-01

    The field of molecule-based magnetism has developed tremendously in the last few years. Two different extended molecular - hence supramolecular -systems are presented. The Prussian-blue analogues show some of the highest magnetic ordering temperature of any class of molecular magnets, T c = 315 K, whereas the class of transition-metal oxalate-bridged compounds exhibits a diversity of magnetic phenomena. Especially for the latter compounds, the elastic neutron scattering technique has successfully been proven to trace the magnetic structure of these supramolecular and chiral compounds. (author) 18 figs., 25 refs

  11. Magnetic resonance imaging apparatus

    International Nuclear Information System (INIS)

    Ehnholm, G.J.

    1991-01-01

    This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

  12. Magnetic Check Valve

    Science.gov (United States)

    Morris, Brian G.; Bozeman, Richard J., Jr.

    1994-01-01

    Poppet in proposed check valve restored to closed condition by magnetic attraction instead of spring force. Oscillations suppressed, with consequent reduction of wear. Stationary magnetic disk mounted just upstream of poppet, also containing magnet. Valve body nonmagnetic. Forward pressure or flow would push poppet away from stationary magnetic disk so fluid flows easily around poppet. Stop in valve body prevents poppet from being swept away. When flow stopped or started to reverse, magnetic attraction draws poppet back to disk. Poppet then engages floating O-ring, thereby closing valve and preventing reverse flow. Floating O-ring facilitates sealing at low loads.

  13. Magnetic nanocomposite sensor

    KAUST Repository

    Alfadhel, Ahmed

    2016-05-06

    A magnetic nanocomposite device is described herein for a wide range of sensing applications. The device utilizes the permanent magnetic behavior of the nanowires to allow operation without the application of an additional magnetic field to magnetize the nanowires, which simplifies miniaturization and integration into microsystems. In5 addition, the nanocomposite benefits from the high elasticity and easy patterning of the polymer-based material, leading to a corrosion-resistant, flexible material that can be used to realize extreme sensitivity. In combination with magnetic sensor elements patterned underneath the nanocomposite, the nanocomposite device realizes highly sensitive and power efficient flexible artificial cilia sensors for flow measurement or tactile sensing.

  14. Magnetism: a supramolecular function

    Energy Technology Data Exchange (ETDEWEB)

    Decurtins, S; Pellaux, R; Schmalle, H W [Zurich Univ., Inst. fuer Anorganische Chemie, Zurich (Switzerland)

    1996-11-01

    The field of molecule-based magnetism has developed tremendously in the last few years. Two different extended molecular - hence supramolecular -systems are presented. The Prussian-blue analogues show some of the highest magnetic ordering temperature of any class of molecular magnets, T{sub c} = 315 K, whereas the class of transition-metal oxalate-bridged compounds exhibits a diversity of magnetic phenomena. Especially for the latter compounds, the elastic neutron scattering technique has successfully been proven to trace the magnetic structure of these supramolecular and chiral compounds. (author) 18 figs., 25 refs.

  15. Magnets in dentistry

    Directory of Open Access Journals (Sweden)

    Vidya S Bhat

    2013-01-01

    Full Text Available Magnets have generated great interest within dentistry. They have been used for various applications in orthodontics and prosthodontics. Earlier use of magnets was limited due to the unavailability of small size magnets, but after the introduction of rare earth magnets and their availability in smaller sizes, their use has increased considerably. They can be placed within prostheses without being obtrusive in the mouth. Their main use in orthodontics has been for tooth movement and in prosthodontics has been in maxillofacial prosthesis and in overdentures as retentive aids. This article reviews the types of magnets available and their application in maxillofacial prosthesis and overdentures, followed by other advantages and disadvantages.

  16. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  17. Optimally segmented magnetic structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bahl, Christian; Bjørk, Rasmus

    We present a semi-analytical algorithm for magnet design problems, which calculates the optimal way to subdivide a given design region into uniformly magnetized segments.The availability of powerful rare-earth magnetic materials such as Nd-Fe-B has broadened the range of applications of permanent...... is not available.We will illustrate the results for magnet design problems from different areas, such as electric motors/generators (as the example in the picture), beam focusing for particle accelerators and magnetic refrigeration devices.......We present a semi-analytical algorithm for magnet design problems, which calculates the optimal way to subdivide a given design region into uniformly magnetized segments.The availability of powerful rare-earth magnetic materials such as Nd-Fe-B has broadened the range of applications of permanent...... magnets[1][2]. However, the powerful rare-earth magnets are generally expensive, so both the scientific and industrial communities have devoted a lot of effort into developing suitable design methods. Even so, many magnet optimization algorithms either are based on heuristic approaches[3...

  18. Superconducting pulsed magnets

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Lecture 1. Introduction to Superconducting Materials Type 1,2 and high temperature superconductors; their critical temperature, field & current density. Persistent screening currents and the critical state model. Lecture 2. Magnetization and AC Loss How screening currents cause irreversible magnetization and hysteresis loops. Field errors caused by screening currents. Flux jumping. The general formulation of ac loss in terms of magnetization. AC losses caused by screening currents. Lecture 3. Twisted Wires and Cables Filamentary composite wires and the losses caused by coupling currents between filaments, the need for twisting. Why we need cables and how the coupling currents in cables contribute more ac loss. Field errors caused by coupling currents. Lecture 4. AC Losses in Magnets, Cooling and Measurement Summary of all loss mechanisms and calculation of total losses in the magnet. The need for cooling to minimize temperature rise in a magnet. Measuring ac losses in wires and in magnets. Lecture 5. Stab...

  19. The magnet database system

    International Nuclear Information System (INIS)

    Ball, M.J.; Delagi, N.; Horton, B.; Ivey, J.C.; Leedy, R.; Li, X.; Marshall, B.; Robinson, S.L.; Tompkins, J.C.

    1992-01-01

    The Test Department of the Magnet Systems Division of the Superconducting Super Collider Laboratory (SSCL) is developing a central database of SSC magnet information that will be available to all magnet scientists at the SSCL or elsewhere, via network connections. The database contains information on the magnets' major components, configuration information (specifying which individual items were used in each cable, coil, and magnet), measurements made at major fabrication stages, and the test results on completed magnets. These data will facilitate the correlation of magnet performance with the properties of its constituents. Recent efforts have focused on the development of procedures for user-friendly access to the data, including displays in the format of the production open-quotes travelerclose quotes data sheets, standard summary reports, and a graphical interface for ad hoc queues and plots

  20. Magnetism in the nineties

    International Nuclear Information System (INIS)

    Freeman, A.J.; Gschneider, K.A. Jr

    1991-01-01

    This special volume aims at providing a historical perspective of the developments that have taken place since the first volume of the Journal of Magnetism and Magnetic Materials, that appeared in late 1975, to identify the most important issues and to provide a perspective for developments anticipated in the 1990's. The papers contained in this book cover many of the scientifically exciting and technologically important aspects of magnetism. They deal with research on various materials including amorphous, permanent and semiconducting magnets, magnetic and magneto-optic recording materials, strongly correlated electron systems and high Tc-superconductors. Several important experimental methods for measuring magnetic behaviour are covered, but the book also contains in-depth theoretical research of fundamental problems in magnetism

  1. Magnetically recoverable nanocatalysts

    KAUST Repository

    Polshettiwar, Vivek

    2011-05-11

    A broad overview on magnetically recoverable nanocatalysts is presented and the use of magnetic nanomaterials as catalysts is discussed. Magnetic materials are used as organocatalysts and their applications range to challenging reactions, such as hydroformylation and olefin metathesis. Magnetic nanomaterials are also being used in environmental applications, such as for photo- and biocatalysis and for the adsorption and removal of pollutants from air and water. These materials show great promise as enantioselective catalysts, which are used extensively for the synthesis of medicines, drugs, and other bioactive molecules. By functionalizing these materials using chiral ligands, a series of chiral nanocatalysts can be designed, offering great potential to reuse these otherwise expensive catalyst systems. Characterization of magnetic catalysts is often a challenging task, and NMR characterization of these catalysts is difficult because the magnetic nature of the materials interferes with the magnetic field of the spectrometer.

  2. Conventional magnets. Pt. 2

    International Nuclear Information System (INIS)

    Marks, N.

    1994-01-01

    This second paper covers the wide range of techniques associated with a.c. and pulsed magnets and associated power supplies. The necessary changes in magnet design to minimise eddy losses in low frequency magnets are first considered and this leads to a broader discussion of the different types of steel used in magnet yokes. Inductance is then considered and the traditional power supply circuit used for a.c. magnets is described. The paper then presents a simple description of the higher-frequency pulsed magnets and supply circuits used for injection and extraction and contrasts a number of different design concepts for both kicker and septum systems. In conclusion, the relevant properties of high-frequency magnetic materials are briefly reviewed. (orig.)

  3. The OPERA magnetic spectrometer

    CERN Document Server

    Ambrosio, M; Dusini, S; Dulach, B; Fanin, C; Felici, G; Corso, F D; Garfagnini, A; Grianti, F; Gustavino, C; Monacelli, P; Paoloni, A; Stanco, L; Spinetti, M; Terranova, F; Votano, L

    2004-01-01

    The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Final...

  4. Invisible magnetic sensors

    Science.gov (United States)

    Mach-Batlle, Rosa; Navau, Carles; Sanchez, Alvaro

    2018-04-01

    Sensing magnetic fields is essential in many applications in biomedicine, transportation, or smart cities. The distortion magnetic sensors create in response to the field they are detecting may hinder their use, for example, in applications requiring dense packaging of sensors or accurately shaped field distributions. For sensing electromagnetic waves, cloaking shells that reduce the scattering of sensors have been introduced. However, the problem of making a magnetic sensor undetectable remains unsolved. Here, we present a general strategy on how to make a sensor magnetically invisible while keeping its ability to sense. The sensor is rendered undetectable by surrounding it with a spherical shell having a tailored magnetic permeability. Our method can be applied to arbitrary shaped magnetic sensors in arbitrary magnetic fields. The invisibility can be made exact when the sensor is spherical and the probed field is uniform. A metasurface composed of superconducting pieces is presented as a practical realization of the ideal invisibility shell.

  5. Magnetically recoverable nanocatalysts

    KAUST Repository

    Polshettiwar, Vivek; Luque, Rafael L.; Fihri, Aziz; Zhu, Haibo; Bouhrara, Mohamed; Basset, Jean-Marie

    2011-01-01

    A broad overview on magnetically recoverable nanocatalysts is presented and the use of magnetic nanomaterials as catalysts is discussed. Magnetic materials are used as organocatalysts and their applications range to challenging reactions, such as hydroformylation and olefin metathesis. Magnetic nanomaterials are also being used in environmental applications, such as for photo- and biocatalysis and for the adsorption and removal of pollutants from air and water. These materials show great promise as enantioselective catalysts, which are used extensively for the synthesis of medicines, drugs, and other bioactive molecules. By functionalizing these materials using chiral ligands, a series of chiral nanocatalysts can be designed, offering great potential to reuse these otherwise expensive catalyst systems. Characterization of magnetic catalysts is often a challenging task, and NMR characterization of these catalysts is difficult because the magnetic nature of the materials interferes with the magnetic field of the spectrometer.

  6. Permanent quadrupole magnets

    International Nuclear Information System (INIS)

    Bush, E.D. Jr.

    1976-01-01

    A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. Based on preliminary tests, it was seen that permanent quadrupole magnets can offer a low cost, reliable solution in applications requiring small, fixed-field focusing devices for use in ion or electron-beam transport systems. Permanent magnets do require special considerations in design, fabrication, handling, and service that are different than encountered in conventional quadrupole magnets. If these basic conditions are satisfied, the resulting beam-focusing device would be stable, maintenance free, with virtually an indefinite lifetime

  7. Magnetism in lanthanide superlattices

    DEFF Research Database (Denmark)

    Goff, J.P.; Sarthour, R.S.; McMorrow, D.F.

    2000-01-01

    Neutron diffraction studies of heavy rare-earth superlattices have revealed the stabilization of novel magnetic phases chat are not present in bulk materials. The most striking result is the propagation of the magnetic ordering through nonmagnetic spacer materials. Here we describe some recent X......-ray magnetic resonant scattering studies of light rare-earth superlattices, which illuminate the mechanism of interlayer coupling, and provide access to different areas of Physics. such as the interplay between superconductivity and magnetism. Magnetic X-ray diffraction is found to be particularly well suited...... to the study of the modulated magnetic structures in superlattices, and provides unique information on the conduction-electron spin-density wave responsible for the propagation of magnetic order. (C) 2000 Elsevier Science B.V. All rights reserved....

  8. Microscale magnetic compasses

    Science.gov (United States)

    Shiozawa, Hidetsugu; Zhang, Desai; Eisterer, Michael; Ayala, Paola; Pichler, Thomas; McCartney, Martha R.; Smith, David J.

    2017-09-01

    Microscale magnetic compasses have been synthesized with high yield. These ferromagnetic iron carbide nano-particles, which are encapsulated in a pair of parallel carbon needles, change their orientation in response to an external magnetic field. Electron holography reveals magnetic fields confined to the vicinity of the bicone-shaped particles, which are composed of only a few ferromagnetic domains. Aligned magnetically and encapsulated in an acrylate polymer matrix, these micro-compasses exhibit anisotropic bulk magnetic permeability with an easy axis normal to the needle direction that can be understood as a result of the anisotropic demagnetizing field of a non-spherical single-domain particle. This novel type of material with orthogonal magnetic and structural axes could be highly useful as magnetic components in electromagnetic wave absorbent materials and magnetorheological fluids.

  9. In-situ magnetization of NdFeB magnets for permanent magnet machines

    International Nuclear Information System (INIS)

    Chang, L.; Eastham, T.R.; Dawson, G.E.

    1991-01-01

    In-situ magnetizers are needed to facilitate the assembly of permanent magnet machines and to remagnetize the magnets after weakening due to a fault condition. The air-core magnetizer in association with the silicon steel lamination structure of the rotor has advantages over its iron-core counterpart. This novel method has been used to magnetize the NdFeB magnets in a 30-hp permanent magnet synchronous motor. The magnetizing capability for different magnetizer geometries was investigated for the magnetization of NdFeB material. The design, testing, and operation of this magnetizer are reported in this paper

  10. Wood construction and magnetic characteristics of impregnated type magnetic wood

    International Nuclear Information System (INIS)

    Oka, Hideo; Hojo, Atsushi; Seki, Kyoushiro; Takashiba, Toshio

    2002-01-01

    The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability

  11. Mercury's Lithospheric Magnetization

    Science.gov (United States)

    Johnson, C.; Phillips, R. J.; Philpott, L. C.; Al Asad, M.; Plattner, A.; Mast, S.; Kinczyk, M. J.; Prockter, L. M.

    2017-12-01

    Magnetic field data obtained by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have been used to demonstrate the presence of lithospheric magnetization on Mercury. Larger amplitude fields resulting from the core dynamo and the strongly time-varying magnetospheric current systems are first estimated and subtracted from the magnetic field data to isolate lithospheric signals with wavelengths less than 500 km. These signals (hereafter referred to as data) are only observed at spacecraft altitudes less than 120 km, and are typically a few to 10 nT in amplitude. We present and compare equivalent source dipole magnetization models for latitudes 35°N to 75°N obtained from two distinct approaches to constrain the distribution and origin of lithospheric magnetization. First, models that fit either the data or the surface field predicted from a regional spherical harmonic representation of the data (see Plattner & Johnson abstract) and that minimize the root mean square (RMS) value of the magnetization are derived. Second, models in which the spatial distribution of magnetization required to fit the data is minimized are derived using the approach of Parker (1991). As seen previously, the largest amplitudes of lithospheric magnetization are concentrated around the Caloris basin. With this exception, across the northern hemisphere there are no overall correlations of magnetization with surface geology, although higher magnetizations are found in regions with darker surfaces. Similarly, there is no systematic correlation of magnetization signatures with crater materials, although there are specific instances of craters with interiors or ejecta that have magnetizations distinct from the surrounding region. For the latter case, we observe no correlation of the occurrence of these signatures with crater degradation state (a proxy for age). At the lowest spacecraft altitudes (source depths less than O(10 km) are unlikely in most regions

  12. Magnetic Field Measurements in Beam Guiding Magnets

    CERN Document Server

    Henrichsen, K N

    1998-01-01

    Electromagnets used as beam guiding elements in particle accelerators and colliders require very tight tole-rances on their magnetic fields and on their alignment along the particle path. This article describes the methods and equipment used for magnetic measurements in beam transport magnets. Descriptions are given of magnetic resonance techniques, various induction coil methods, Hall generator measurements, the fluxgate magnetometer as well as the recently developed method of beam based alignment. References of historical nature as well as citations of recent work are given. The present commercial availability of the different sensors and asso-ciated equipment is indicated. Finally we shall try to analyze possible future needs for developments in those fields.

  13. Magnetic Excitations and Magnetic Ordering in Praseodymium

    DEFF Research Database (Denmark)

    Houmann, Jens Christian Gylden; Chapellier, M.; Mackintosh, A. R.

    1975-01-01

    The dispersion relations for magnetic excitons propagating on the hexagonal sites of double-hcp Pr provide clear evidence for a pronounced anisotropy in the exchange. The energy of the excitations decreases rapidly as the temperature is lowered, but becomes almost constant below about 7 K......, in agreement with a random-phase-approximation calculation. No evidence of magnetic ordering has been observed above 0.4 K, although the exchange is close to the critical value necessary for an antiferromagnetic state....

  14. Performance of Magnetic Filter for Separation of Magnetic Gel Particles

    OpenAIRE

    栗延, 俊太郎; 尾崎, 博明; 渡辺, 恒雄; クリノブ, シュンタロウ; オザキ, ヒロアキ; ワタナベ, ツネオ; Shuntaro, KURINOBU; Hiroaki, OZAKI; Tuneo, WATANABE

    2003-01-01

    We have developed a new wastewater treatment process using magnetic gel particles containing immobilized microorganisms and magnetic particles. The performance of magnetic gel particles using a magnetic filter is very important to control the process. In this study, the performance of a magnetic filter was studied for magnetic gel, particles. Agar particles containing magnetite particles were used as gel particles. The recovery and the relative retention area of magnetic gel particles on the ...

  15. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.; Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  16. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira.

    1997-01-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process

  17. Magnetism in Medicine

    Science.gov (United States)

    Schenck, John

    2000-03-01

    For centuries physicians, scientists and others have postulated an important role, either as a cause of disease or as a mode of therapy, for magnetism in medicine. Although there is a straightforward role in the removal of magnetic foreign bodies, the majority of the proposed magnetic applications have been controversial and have often been attributed by mainstream practitioners to fraud, quackery or self-deception. Calculations indicate that many of the proposed methods of action, e.g., the field-induced alignment of water molecules or alterations in blood flow, are of negligible magnitude. Nonetheless, even at the present time, the use of small surface magnets (magnetotherapy) to treat arthritis and similar diseases is a widespread form of folk medicine and is said to involve sales of approximately one billion dollars per year. Another medical application of magnetism associated with Mesmer and others (eventually known as animal magnetism) has been discredited, but has had a culturally significant role in the development of hypnotism and as one of the sources of modern psychotherapy. Over the last two decades, in marked contrast to previous applications of magnetism to medicine, magnetic resonance imaging or MRI, has become firmly established as a clinical diagnostic tool. MRI permits the non-invasive study of subtle biological processes in intact, living organisms and approximately 150,000,000 diagnostic studies have been performed since its clinical introduction in the early 1980s. The dramatically swift and widespread acceptance of MRI was made possible by scientific and engineering advances - including nuclear magnetic resonance, computer technology and whole-body-sized, high field superconducting magnets - in the decades following World War Two. Although presently used much less than MRI, additional applications, including nerve and muscle stimulation by pulsed magnetic fields, the use of magnetic forces to guide surgical instruments, and imaging utilizing

  18. Kicker magnet design

    International Nuclear Information System (INIS)

    Li, Z.; Thiessen, H.A.

    1989-01-01

    In this paper, the kicker magnet is studied by use of the program POISSON. For using the dc-code POISSON in the ac problem of the kicker magnet, an approximation of the ac effects is made, this simplifying the ac problem into a dc problem. The study of the magnet is taken in two steps: assuming the γ of the ferrite material is fixed in the calculation to get a preliminary design of the magnet; using the real B /minus/ H curve of the CMD5005 ferrite material in the calculation to get the final design of the magnet. The stored energy, the excitation curve and the excitation efficiency of the kicker magnet are also discussed. 10 figs., 7 tabs

  19. The 2017 Magnetism Roadmap

    Science.gov (United States)

    Sander, D.; Valenzuela, S. O.; Makarov, D.; Marrows, C. H.; Fullerton, E. E.; Fischer, P.; McCord, J.; Vavassori, P.; Mangin, S.; Pirro, P.; Hillebrands, B.; Kent, A. D.; Jungwirth, T.; Gutfleisch, O.; Kim, C. G.; Berger, A.

    2017-09-01

    Building upon the success and relevance of the 2014 Magnetism Roadmap, this 2017 Magnetism Roadmap edition follows a similar general layout, even if its focus is naturally shifted, and a different group of experts and, thus, viewpoints are being collected and presented. More importantly, key developments have changed the research landscape in very relevant ways, so that a novel view onto some of the most crucial developments is warranted, and thus, this 2017 Magnetism Roadmap article is a timely endeavour. The change in landscape is hereby not exclusively scientific, but also reflects the magnetism related industrial application portfolio. Specifically, Hard Disk Drive technology, which still dominates digital storage and will continue to do so for many years, if not decades, has now limited its footprint in the scientific and research community, whereas significantly growing interest in magnetism and magnetic materials in relation to energy applications is noticeable, and other technological fields are emerging as well. Also, more and more work is occurring in which complex topologies of magnetically ordered states are being explored, hereby aiming at a technological utilization of the very theoretical concepts that were recognised by the 2016 Nobel Prize in Physics. Given this somewhat shifted scenario, it seemed appropriate to select topics for this Roadmap article that represent the three core pillars of magnetism, namely magnetic materials, magnetic phenomena and associated characterization techniques, as well as applications of magnetism. While many of the contributions in this Roadmap have clearly overlapping relevance in all three fields, their relative focus is mostly associated to one of the three pillars. In this way, the interconnecting roles of having suitable magnetic materials, understanding (and being able to characterize) the underlying physics of their behaviour and utilizing them for applications and devices is well illustrated, thus giving an

  20. The 2017 Magnetism Roadmap

    International Nuclear Information System (INIS)

    Sander, D; Valenzuela, S O; Makarov, D

    2017-01-01

    Building upon the success and relevance of the 2014 Magnetism Roadmap, this 2017 Magnetism Roadmap edition follows a similar general layout, even if its focus is naturally shifted, and a different group of experts and, thus, viewpoints are being collected and presented. More importantly, key developments have changed the research landscape in very relevant ways, so that a novel view onto some of the most crucial developments is warranted, and thus, this 2017 Magnetism Roadmap article is a timely endeavour. The change in landscape is hereby not exclusively scientific, but also reflects the magnetism related industrial application portfolio. Specifically, Hard Disk Drive technology, which still dominates digital storage and will continue to do so for many years, if not decades, has now limited its footprint in the scientific and research community, whereas significantly growing interest in magnetism and magnetic materials in relation to energy applications is noticeable, and other technological fields are emerging as well. Also, more and more work is occurring in which complex topologies of magnetically ordered states are being explored, hereby aiming at a technological utilization of the very theoretical concepts that were recognised by the 2016 Nobel Prize in Physics. Given this somewhat shifted scenario, it seemed appropriate to select topics for this Roadmap article that represent the three core pillars of magnetism, namely magnetic materials, magnetic phenomena and associated characterization techniques, as well as applications of magnetism. While many of the contributions in this Roadmap have clearly overlapping relevance in all three fields, their relative focus is mostly associated to one of the three pillars. In this way, the interconnecting roles of having suitable magnetic materials, understanding (and being able to characterize) the underlying physics of their behaviour and utilizing them for applications and devices is well illustrated, thus giving an

  1. Nuclear magnetic resonance apparatus

    International Nuclear Information System (INIS)

    Lambert, R.

    1991-01-01

    In order to include the effect of a magnetic object in a subject under investigation, Nuclear Magnetic Resonance (NMR) apparatus is operable at more than one radio frequency (RF) frequency. The apparatus allows normal practice as far as obtaining an NMR response or image from a given nuclear species is concerned, but, in addition, interrogates the nuclear spin system at a frequency which is different from the resonance frequency normally used for the given nuclear species, as determined from the applied magnetic field. The magnetic field close to a magnetised or magnetisable object is modified and the given nuclear species gives a response at the different frequency. Thus detection of a signal at the frequency indicates the presence of the chosen nuclei close to the magnetised or magnetisable object. Applications include validation of an object detection or automatic shape inspection system in the presence of magnetic impurities, and the detection of magnetic particles which affect measurement of liquid flow in a pipe. (author)

  2. Magnetic nanoparticle assemblies

    CERN Document Server

    Trohidou, Kalliopi N

    2014-01-01

    Magnetic nanoparticles with diameters in the range of a few nanometers are today at the cutting edge of modern technology and innovation because of their use in numerous applications ranging from engineering to biomedicine. A great deal of scientific interest has been focused on the functionalization of magnetic nanoparticle assemblies. The understanding of interparticle interactions is necessary to clarify the physics of these assemblies and their use in the development of high-performance magnetic materials. This book reviews prominent research studies on the static and dynamic magnetic properties of nanoparticle assemblies, gathering together experimental and computational techniques in an effort to reveal their optimized magnetic properties for biomedical use and as ultra-high magnetic recording media.

  3. Superconducting accelerator magnet design

    International Nuclear Information System (INIS)

    Wolff, S.

    1994-01-01

    Superconducting dipoles, quadrupoles and correction magnets are necessary to achieve the high magnetic fields required for big accelerators presently in construction or in the design phase. Different designs of superconducting accelerator magnets are described and the designs chosen at the big accelerator laboratories are presented. The most frequently used cosθ coil configuration is discussed in detail. Approaches for calculating the magnetic field quality including coil end fields are presented. Design details of the cables, coils, mechanical structures, yokes, helium vessels and cryostats including thermal radiation shields and support structures used in superconducting magnets are given. Necessary material properties are mentioned. Finally, the main results of magnetic field measurements and quench statistics are presented. (orig.)

  4. Remanent magnetism at Mars

    Science.gov (United States)

    Curtis, S. A.; Ness, N. F.

    1988-01-01

    It is shown that a strong case can be made for an intrinsic magnetic field of dynamo origin for Mars earlier in its history. The typical equatorial magnetic field intensity would have been equal to about 0.01-0.1 gauss. The earlier dynamo activity is no longer extant, but a significant remanent magnetic field may exist. A highly non-dipole magnetic field could result from the remanent magnetization of the surface. Remanent magnetization may thus play an important role in the Mars solar wind interactions, in contrast to Venus with its surface temperatures above the Curie point. The anomalous characteristics of Mars'solar wind interaction compared to that of Venus may be explicable on this basis.

  5. Passive magnetic bearing system

    Science.gov (United States)

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  6. Magnetic particle separation using controllable magnetic force switches

    International Nuclear Information System (INIS)

    Wei Zunghang; Lee, C.-P.; Lai, M.-F.

    2010-01-01

    Magnetic particle separation is very important in biomedical applications. In this study, a magnetic particle microseparator is proposed that uses micro magnets to produce open/closed magnetic flux for switching on/off the separation. When all magnets are magnetized in the same direction, the magnetic force switch for separation is on; almost all magnetic particles are trapped in the channel side walls and the separation rate can reach 95%. When the magnetization directions of adjacent magnets are opposite, the magnetic force switch for separation is off, and most magnetic particles pass through the microchannel without being trapped. For the separation of multi-sized magnetic particles, the proposed microseparator is numerically demonstrated to have high separation rate.

  7. Permanent magnet based dipole magnets for next generation light sources

    Directory of Open Access Journals (Sweden)

    Takahiro Watanabe

    2017-07-01

    Full Text Available We have developed permanent magnet based dipole magnets for the next generation light sources. Permanent magnets are advantageous over electromagnets in that they consume less power, are physically more compact, and there is a less risk of power supply failure. However, experience with electromagnets and permanent magnets in the field of accelerators shows that there are still challenges to replacing main magnets of accelerators for light sources with permanent magnets. These include the adjustability of the magnetic field, the temperature dependence of permanent magnets, and the issue of demagnetization. In this paper, we present a design for magnets for future light sources, supported by experimental and numerical results.

  8. Organic magnetic field sensor

    Energy Technology Data Exchange (ETDEWEB)

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  9. Magnetic conditioning in superfluid

    International Nuclear Information System (INIS)

    Caspi, S.

    1988-08-01

    Improvements in superconducting magnet technology have reduced to a handful the number of training quenches typical of dipole magnets. The number of training quenches in long (17 m) and short (1--2 m) SSC magnets are now about the same (operating at 6.6 tesla and 4.4 K). Yet the steps necessary to totally eliminate training are in the future RandD plans for magnet construction and conductor motion prevention. The accepted hypothesis is that Lorentz forces and poor mechanical properties of superconducting cables are the cause of conductor motion. Conductor motion reduces the stored energy in the cable by converting it into heat. The small amount of heat generated (millijoules) during motion is usually enough to quench the magnet when it is close to short sample. During training, the magnet performance normally improves with the number of quenches. It is not the quench itself that improves magnet performance but rather the fact that once conductor motion has occurred it will probably not repeat itself unless subjected to higher forces. Conditioning is a process that enables the magnet to reduce its stored energy without causing a premature quench. During the conditioning process the magnet is further cooled from its operating temperature of 4.4 K to 1.8 K by converting He I into He II. As a result the magnet is placed in a state where it has excess stability as well as excellent heat transfer capabilities. Although this does not eliminate motion, if the magnet is now cycled to /approximately/10% above its operating field at 4.4 K (which is above short sample) the excess stability should be enough to prevent quenching and reduce the probability of conductor motion and training once the magnet has been warmed back up to its operating temperature of 4.4 K. 3 refs., 5 figs

  10. Magnetic conditioning in superfluid

    Energy Technology Data Exchange (ETDEWEB)

    Caspi, S.

    1988-08-01

    Improvements in superconducting magnet technology have reduced to a handful the number of training quenches typical of dipole magnets. The number of training quenches in long (17 m) and short (1--2 m) SSC magnets are now about the same (operating at 6.6 tesla and 4.4 K). Yet the steps necessary to totally eliminate training are in the future RandD plans for magnet construction and conductor motion prevention. The accepted hypothesis is that Lorentz forces and poor mechanical properties of superconducting cables are the cause of conductor motion. Conductor motion reduces the stored energy in the cable by converting it into heat. The small amount of heat generated (millijoules) during motion is usually enough to quench the magnet when it is close to short sample. During training, the magnet performance normally improves with the number of quenches. It is not the quench itself that improves magnet performance but rather the fact that once conductor motion has occurred it will probably not repeat itself unless subjected to higher forces. Conditioning is a process that enables the magnet to reduce its stored energy without causing a premature quench. During the conditioning process the magnet is further cooled from its operating temperature of 4.4 K to 1.8 K by converting He I into He II. As a result the magnet is placed in a state where it has excess stability as well as excellent heat transfer capabilities. Although this does not eliminate motion, if the magnet is now cycled to /approximately/10% above its operating field at 4.4 K (which is above short sample) the excess stability should be enough to prevent quenching and reduce the probability of conductor motion and training once the magnet has been warmed back up to its operating temperature of 4.4 K. 3 refs., 5 figs.

  11. Controlling magnetic field profiles

    International Nuclear Information System (INIS)

    Freeman, J.R.

    1979-04-01

    A method for designing solenoid magnets with controlled field profiles is discussed. The method, originated by D.B. Montgomery, minimizes both the field errors and the power consumption. An NOS time-sharing computer program for the CDC-6600, entitled MAGCOR, was constructed to provide an interactive magnet design capability. Results obtained during the design of magnets for a radial line electron accelerator are presented. 9 figures

  12. Generation of magnetic fields for accelerators with permanent magnets

    International Nuclear Information System (INIS)

    Meinander, T.

    1994-01-01

    Commercially available permanent magnet materials and their properties are reviewed. Advantages and disadvantages of using permanent magnets as compared to electromagnets for the generation of specific magnetic fields are discussed. Basic permanent magnet configurations in multipole magnets and insertion devices are presented. (orig.)

  13. Magnetic and viscoelastic response of elastomers with hard magnetic filler

    International Nuclear Information System (INIS)

    Kramarenko, E Yu; Chertovich, A V; Semisalova, A S; Makarova, L A; Perov, N S; Khokhlov, A R; Stepanov, G V

    2015-01-01

    Magnetic elastomers (MEs) based on a silicone matrix and magnetically hard NdFeB particles have been synthesized and their magnetic and viscoelastic properties have been studied depending on the size and concentration of magnetic particles and the magnetizing field. It has been shown that magnetic particles can rotate in soft polymer matrix under applied magnetic field, this fact leading to some features in both magnetic and viscoelastic properties. In the maximum magnetic field used magnetization of MEs with smaller particles is larger while the coercivity is smaller due to higher mobility of the particles within the polymer matrix. Viscoelastic behavior is characterized by long relaxation times due to restructuring of the magnetic filler under the influence of an applied mechanical force and magnetic interactions. The storage and loss moduli of magnetically hard elastomers grow significantly with magnetizing field. The magnetic response of the magnetized samples depends on the mutual orientation of the external magnetic field and the internal sample magnetization. Due to the particle rotation within the polymer matrix, the loss factor increases abruptly when the magnetic field is turned on in the opposite direction to the sample magnetization, further decreasing with time. Moduli versus field dependences have minimum at non-zero field and are characterized by a high asymmetry with respect to the field direction. (paper)

  14. The dynamic behavior of magnetic fluid adsorbed to small permanent magnet in alternating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sudo, Seiichi, E-mail: sudo@akita-pu.ac.j [Faculty of Systems Science and Technology, Akita Prefectural University, Ebinokuchi 84-4, Yurihonjo 015-0055 (Japan); Asano, Daisaku [Faculty of Systems Science and Technology, Akita Prefectural University, Ebinokuchi 84-4, Yurihonjo 015-0055 (Japan); Takana, Hidemasa; Nishiyama, Hideya [Institute of Fluid Science, Tohoku University, Katahira 2-1-1, Aobaku, Sendai 980-8577 (Japan)

    2011-05-15

    The dynamic behavior of a magnetic fluid adsorbed to a small NdFeB permanent magnet subjected to an alternating magnetic field was studied with a high speed video camera system. The directions of alternating magnetic field are parallel and opposite to that of the permanent magnet. It was found that the surface of magnetic fluid responds to the external alternating magnetic field in elongation and contraction with a lot of spikes. Generation of a capillary magnetic fluid jet was observed in the neighbourhood of a specific frequency of alternating field. The effect of gravitational force on surface phenomena of magnetic fluid adsorbed to the permanent magnet was revealed. - Research Highlights: Magnetic fluid of the system responds to alternating magnetic field with higher frequencies. Large-amplitude surface motions of magnetic fluid occur at the specific frequencies of the external field. Capillary jets of magnetic fluid are generated at the natural frequency of the system.

  15. Magnetic Structure of Erbium

    DEFF Research Database (Denmark)

    Gibbs, D.; Bohr, Jakob; Axe, J. D.

    1986-01-01

    We present a synchrotron x-ray scattering study of the magnetic phases of erbium. In addition to the magnetic scattering located at the fundamental wave vector τm we also observe scattering from magnetoelastically induced charge modulations at the fundamental wave vector, at twice the fundamental......, and at positions split symmetrically about the fundamental. As the temperature is lowered below 52 K the charge and magnetic scattering display a sequence of lock-in transitions to rational wave vectors. A spin-slip description of the magnetic structure is presented which explains the wave vectors...

  16. Magnetic S-parameter

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2010-01-01

    We propose a direct test of the existence of gauge duals for nonsupersymmetric asymptotically free gauge theories developing an infrared fixed point by computing the S-parameter in the electric and dual magnetic description. In particular we show that at the lower bound of the conformal window...... the magnetic S-parameter, i.e. the one determined via the dual magnetic gauge theory, assumes a simple expression in terms of the elementary magnetic degrees of freedom. The results further support our recent conjecture of the existence of a universal lower bound on the S parameter and indicates...

  17. Manufacturing the MFTF magnet

    International Nuclear Information System (INIS)

    Dalder, E.N.C.; Hinkle, R.E.; Hodges, A.J.

    1980-01-01

    The Mirror Fusion Test Facility (MFTF) is a large mirror program experiment for magnetic fusion energy. It will combine and extend the near-classical plasma confinement achieved in 2XIIB with advanced neutral-beam and magnet technologies. The product of ion density and confinement time will be improved more than an order of magnitude, while the superconducting magnet weight will be extrapolated from 15 tons in Baseball II to 375 tons in MFTF. Recent reactor studies show that the MFTF will traverse much of the distance in magnet technology towards the reactor regime

  18. Advanced Nanostructured Magnetic Materials

    National Research Council Canada - National Science Library

    Sellmyer, David J

    2004-01-01

    ... out. Novel physical systems have been synthesized and studied including: hard/soft nanocomposites, magnetic nanowires, thermally processed multilayer films, and nanoparticle-assembled composites...

  19. Magnets becoming more super

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-09-15

    With the twenty year struggle to master superconducting magnets for accelerators behind them, magnet specialists are now very confident of their ability to use superconductivity in accelerator design. Superconductor performance has improved considerably in the past few years and we may well see the number of these magnets escalate from the present figure of about a thousand to over fifteen thousand within the next decade. This confidence emerged clearly from a recent Workshop at Brookhaven, organized by the Panel on Superconducting Magnets and Cryogenics set up by the International Committee on Future Accelerators (ICFA)

  20. Nuclear magnetic resonance scattering

    International Nuclear Information System (INIS)

    Young, I.R.

    1985-01-01

    A nuclear magnetic resonance apparatus is described including a magnet system which is capable of providing a steady magnetic field along an axis, and is constructed so as to define a plurality of regions along the axis in each of which the field is substantially homogeneous so that in each region an imaging operation may be separately carried out. Iron shields increase the field homogeneity. In use, each patient lies on a wheeled trolley which is provided with magnetic field gradient coils and an RF coil system, some of the coils being movable to facilitate positioning of the patient, and there are terminals for connection to a common computing and control facility. (author)

  1. Electromechanical magnetization switching

    Energy Technology Data Exchange (ETDEWEB)

    Chudnovsky, Eugene M. [Department of Physics and Astronomy, Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589 (United States); Jaafar, Reem [Department of Mathematics, Engineering and Computer Science, LaGuardia Community College, The City University of New York, 31-10 Thomson Avenue, Long Island City, New York 11101 (United States)

    2015-03-14

    We show that the magnetization of a torsional oscillator that, in addition to the magnetic moment also possesses an electrical polarization, can be switched by the electric field that ignites mechanical oscillations at the frequency comparable to the frequency of the ferromagnetic resonance. The 180° switching arises from the spin-rotation coupling and is not prohibited by the different symmetry of the magnetic moment and the electric field as in the case of a stationary magnet. Analytical equations describing the system have been derived and investigated numerically. Phase diagrams showing the range of parameters required for the switching have been obtained.

  2. Electromechanical magnetization switching

    International Nuclear Information System (INIS)

    Chudnovsky, Eugene M.; Jaafar, Reem

    2015-01-01

    We show that the magnetization of a torsional oscillator that, in addition to the magnetic moment also possesses an electrical polarization, can be switched by the electric field that ignites mechanical oscillations at the frequency comparable to the frequency of the ferromagnetic resonance. The 180° switching arises from the spin-rotation coupling and is not prohibited by the different symmetry of the magnetic moment and the electric field as in the case of a stationary magnet. Analytical equations describing the system have been derived and investigated numerically. Phase diagrams showing the range of parameters required for the switching have been obtained

  3. Magnetically leviated superconducting bearing

    Science.gov (United States)

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    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.

  4. Cochlear implant magnet retrofit.

    Science.gov (United States)

    Cohen, N L; Breda, S D; Hoffman, R A

    1988-06-01

    An implantable magnet is now available for patients who have received the standard Nucleus 22-channel cochlear implant and who are not able to wear the headband satisfactorily. This magnet is attached in piggy-back fashion to the previously implanted receiver/stimulator by means of a brief operation under local anesthesia. Two patients have received this magnet retrofit, and are now wearing the headset with greater comfort and satisfaction. It is felt that the availability of this magnet will increase patient compliance in regard to hours of implant usage.

  5. Magnetic vortex filament flows

    International Nuclear Information System (INIS)

    Barros, Manuel; Cabrerizo, Jose L.; Fernandez, Manuel; Romero, Alfonso

    2007-01-01

    We exhibit a variational approach to study the magnetic flow associated with a Killing magnetic field in dimension 3. In this context, the solutions of the Lorentz force equation are viewed as Kirchhoff elastic rods and conversely. This provides an amazing connection between two apparently unrelated physical models and, in particular, it ties the classical elastic theory with the Hall effect. Then, these magnetic flows can be regarded as vortex filament flows within the localized induction approximation. The Hasimoto transformation can be used to see the magnetic trajectories as solutions of the cubic nonlinear Schroedinger equation showing the solitonic nature of those

  6. Magnetic rubber inspection (MRI)

    International Nuclear Information System (INIS)

    Carro, L.

    1997-01-01

    Magnetic Rubber Inspection (MRI) was developed to inspect for small cracks and flaws encountered in high performance aircraft. A formula of very fine magnetic particles immersed in a room temperature curing rubber is catalysed and poured into dams (retainers) on the surface of the part to be inspected. Inducing a magnetic field then causes the particles to be drawn to discontinuities in the component under test. These indicating particles are held to the discontinuity by magnetic attraction, as the rubber cures. The solid rubber cast (Replica) is then removed and examined under a microscope for indicating lines of particle concentrations. 3 refs., 6 figs

  7. LHCb experiment magnets

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The leading members of the LHCb magnet project, from left to right: Pierre-Ange Giudici, who organized and supervised the industrial production of the coils; Marcello Losasso, who performed the 3D calculations to optimise the magnetic field; Olivier Jamet, responsible for the 3D design; Jean Renaud, in charge of the magnet assembly, and Wilfried Flegel, project leader. The LHCb detector will investigate matter-antimatter differences in B mesons at the LHC. The coils of the detector's huge dipole magnet are seen here in April 2004.

  8. Magnetism v.5

    CERN Document Server

    Suhl, Harry

    1973-01-01

    Magnetism, Volume V: Magnetic Properties of Metallic Alloys deals with the magnetic properties of metallic alloys and covers topics ranging from conditions favoring the localization of effective moments to the s-d model and the Kondo effect, along with perturbative, scattering, and Green's function theories of the s-d model. Asymptotically exact methods used in addressing the Kondo problem are also described.Comprised of 12 chapters, this volume begins with a review of experimental results and phenomenology concerning the formation of local magnetic moments in metals, followed by a Har

  9. Strong Magnetic Field Characterisation

    Science.gov (United States)

    2012-04-01

    an advertised surface field of approximately 0.5 T were used to supply the static magnetic field source. The disc magnet had a diameter of 50 mm and... colour bar indicates the magnetic field strength set to an arbitrary 0.25 T. The white area has a field >0.25 T. The size of the arrow is proportional...9 shows the magnetic field strength along a slice in the XZ plane. The colours represent the total UNCLASSIFIED 10 UNCLASSIFIED DSTO-TR-2699

  10. Conventional magnets. Pt. 1

    International Nuclear Information System (INIS)

    Marks, N.

    1994-01-01

    The design and construction of conventional, steel-cored, direct-current magnets are discussed. Laplace's equation and the associated cylindrical harmonic solutions in two dimensions are established. The equations are used to define the ideal pole shapes and required excitation for dipole, quadrupole and sextupole magnets. Standard magnet geometries are then considered and criteria determining the coil design are presented. The use of codes for predicting flux density distributions and the iterative techniques used for pole face design are then discussed. This includes a description of the use of two-dimensional codes to generate suitable magnet end geometries. Finally, standard constructional techniques for cores and coils are described. (orig.)

  11. Magnetic study of turbidites

    Science.gov (United States)

    Tanty, Cyrielle; Valet, Jean Pierre; Carlut, Julie

    2015-04-01

    Turbidites induce sedimentary reworking and re-deposition caused by tsunami, earthquake, volcanic processes, and other catastrophic events. They result from rapid depositional processes and are thus considered not being pertinent for comparison with pelagic sediments. Turbidites are evidently ruled out from paleomagnetic records dealing with time-series. Consequently, no attention has ever been paid to the magnetization of turbidites which is fully justified if the high level of turbulence governing the depositional processes influences the acquisition of magnetization. In certain conditions like channeled turbidity currents, levees of sediment are generated and then associated with relatively calm although very fast redeposition processes. Such conditions will thus govern the subsequent acquisition of magnetization through mechanical lock-in of the magnetic grains. This situation is actually quite similar to what happens during the experiences of artificial redeposition that are conducted in laboratory. Therefore, combining laboratory experiments and studies of natural turbidites could reveal important information on the processes involved in the acquisition of magnetization, especially if the comparison with the overlying hemipelagic sediments does not show any striking difference. We will present the results of magnetic measurements performed on four different and relatively recent turbidites. We selected different origins associated either with spillover of channeled turbidity currents or with co-seismic faulting. Each event is characterized by a different thickness (ten to few tens of cm), lithology and mean granulometry (few tens of μm to hundreds of μm). We have carried out measurements of magnetic susceptibility, magnetic remanence, anisotropy of magnetic susceptibility (AMS) and we also scrutinize the evolution of various rock magnetic parameters (ARM, IRM, S ratio, magnetic grain sizes, hysteresis parameters…). The magnetic characteristics of the

  12. Ultrafast magnetization dynamics in diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Morandi, O [INRIA Nancy Grand-Est and Institut de Recherche en Mathematiques Avancees, 7 rue Rene Descartes, F-67084 Strasbourg (France); Hervieux, P-A; Manfredi, G [Institut de Physique et Chimie des Materiaux de Strasbourg, 23 rue du Loess, F-67037 Strasbourg (France)], E-mail: morandi@dipmat.univpm.it

    2009-07-15

    We present a dynamical model that successfully explains the observed time evolution of the magnetization in diluted magnetic semiconductor quantum wells after weak laser excitation. Based on the pseudo-fermion formalism and a second-order many-particle expansion of the exact p-d exchange interaction, our approach goes beyond the usual mean-field approximation. It includes both the sub-picosecond demagnetization dynamics and the slower relaxation processes that restore the initial ferromagnetic order in a nanosecond timescale. In agreement with experimental results, our numerical simulations show that, depending on the value of the initial lattice temperature, a subsequent enhancement of the total magnetization may be observed within the timescale of a few hundred picoseconds.

  13. High performance permanent magnet materials

    International Nuclear Information System (INIS)

    Sankar, S.G.; Herbst, J.F.; Koon, N.C.

    1987-01-01

    This book contains 25 selections. Some of the titles are: Initial magnetization behavior of rapidly quenched neodymium-iron-boron magnets; Optimization of liquid dynamic compaction for Fe-Nd-B magnet alloys; Misch-metal and/or aluminum substitutions in Nd-Fe-B permanent magnets; and NdFeB magnets with improved temperature characteristics

  14. Magnetic fields at Neptune

    International Nuclear Information System (INIS)

    Ness, N.F.; Acuna, M.H.; Burlaga, L.F.; Connerney, J.E.P.; Lepping, R.P.; Neubauer, F.M.

    1989-01-01

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10 -5 gauss) was observed near closest approach, at a distance of 1.18 R N . The planetary magnetic field between 4 and 15 R N can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R N and inclined by 47 degrees with respect to the rotation axis. Within 4 R N , the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes in the diurnally varying magnetosphere configuration. In an astrophysical context, the magnetic field of Neptune, like that of Uranus, may be described as that of an oblique rotator

  15. Magnetic Particle inspection by DC and AC magnetization current

    International Nuclear Information System (INIS)

    Lim, Zhong Soo; Kim, Goo Hwa

    1996-01-01

    Dry magnetic particle inspection was performed to detect the surface defects of the steel billets. The detectability was evaluated according to magnetizing current, temperature, and amount of the magnetic particles on material. We selected a certain set of steel compositions for target materials. Their magnetic properties are measured with B-H hysteresis graph. Results of the magnetic particle inspection(MPI) by direct magnetizing current was compared with results of the finite element method calculations, which were verified by measurement of the magnetic leakage flux above the surface of material. For square rod materials, the magnetic flux density at the corner was about 30% of that at the face center with sufficiently large direct magnetizing current, while it is about 70% with alternating magnetizing current. Alternating magnetizing current generates rather uniform magnetic flux density running from the center to the corner except for the region of about 10 mm extending from the corner.

  16. Tuning magnetic avalanches in the molecular magnet Mn12 -acetate

    Science.gov (United States)

    McHugh, S.; Wen, Bo; Ma, Xiang; Sarachik, M. P.; Myasoedov, Y.; Zeldov, E.; Bagai, R.; Christou, G.

    2009-05-01

    Using micron-sized Hall sensor arrays to obtain time-resolved measurements of the local magnetization, we report a systematic study in the molecular magnet Mn12 acetate of magnetic avalanches controllably triggered in different fixed external magnetic fields and for different values of the initial magnetization. The speeds of propagation of the spin-reversal fronts are in good overall agreement with the theory of magnetic deflagration of Garanin and Chudnovsky [Phys. Rev. B 76, 054410 (2007)].

  17. Magnetic moment measurement of magnetic nanoparticles using atomic force microscopy

    International Nuclear Information System (INIS)

    Park, J-W; Lee, E-C; Ju, H; Yoo, I S; Chang, W-S; Chung, B H; Kim, B S

    2008-01-01

    Magnetic moment per unit mass of magnetic nanoparticles was found by using the atomic force microscope (AFM). The mass of the nanoparticles was acquired from the resonance frequency shift of the particle-attached AFM probe and magnetic force measurement was also carried out with the AFM. Combining with magnetic field strength, the magnetic moment per unit mass of the nanoparticles was determined as a function of magnetic field strength. (technical design note)

  18. Structure and magnetic field of periodic permanent magnetic focusing system with open magnetic rings

    International Nuclear Information System (INIS)

    Peng Long; Li Lezhong; Yang Dingyu; Zhu Xinghua; Li Yuanxun

    2011-01-01

    The magnetic field along the central axis for an axially magnetized permanent magnetic ring was investigated by analytical and finite element methods. For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. A new structure of periodic permanent magnet focusing system with open magnetic rings is proposed. The structure provides a satisfactory magnetic field with a stable peak value of 120 mT for a traveling wave tube system. - Research highlights: → For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. → A new structure of periodic permanent magnet (PPM) focusing system with open magnetic rings is proposed. → The new PPM focusing system with open magnetic rings meets the requirements for TWT system.

  19. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  20. CERN: LHC magnets

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    With test magnets for CERN's LHC proton-proton collider regularly attaining field strengths which show that 10 Tesla is not forbidden territory, attention turns to why and where quenches happen. If 'training' can be reduced, superconducting magnets become easier to commission

  1. Wobbly Corner: Magnetism

    Science.gov (United States)

    Corbett, Lisa; Maklad, Rania; Dunne, Mick; Grace, Pierre

    2014-01-01

    During a final seminar with BA year 4 science specialist trainee teachers, the authors posed a question about the difficulties associated with understanding magnetism. The ensuing discussion focused on a number of concerns commonly identified by students, which may also be of interest to classroom teachers teaching magnetism. Issues raised…

  2. Cosmological magnetic fields - V

    Indian Academy of Sciences (India)

    Magnetic fields seem to be everywhere that we can look in the universe, from our own ... The field tensor is observer-independent, while the electric and magnetic .... based on string theory [11], in which vacuum fluctuations of the field are ...

  3. Magnetizing the universe

    Indian Academy of Sciences (India)

    K. Subramanian, ”Magnetizing the Universe”, PoS proceedings, arXiv:0802.2804. IAS Annual ... If this electric field has a curl, can re-generate magnetic fields. ∂B. ∂t .... How to do mean field theory in presence of strong noise? Does the Early ...

  4. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab

  5. Checking BEBC superconducting magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The superconducting coils of the magnet for the 3.7 m Big European Bubble Chamber (BEBC) had to be checked, see Annual Report 1974, p. 60. The photo shows a dismantled pancake. By December 1974 the magnet reached again the field design value of 3.5 T.

  6. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Magnetic resonance imaging (MRI) is a new and innovative technique that affords anatomic images in multiple planes and that may provide information about tissue characterization. The magnetic resonance images are obtained by placing the patient or the area of interest within a powerful, highly uniform, static magnetic field. Magnetized protons (hydrogen nuclei) within the patient align like small magnets in this field. Radiofrequency pulses are then used to create an oscillating magnetic field perpendicular to the main field. Magnetic resonance images differ from those produced by x-rays: the latter are associated with absorption of x-ray energy while magnetic resonance images are based on proton density and proton relaxation dynamics. Proton characteristics vary according to the tissue under examination and reflect its physical and chemical properties. To resolve issues regarding safety and efficacy, the Warren Grant Magnuson Clinical Center and the Office of Medical Applications of Research of the National Institutes of Health (NIH) convened a consensus conference about MRI Oct 26 through 28, 1987. At the NIH, the Consensus Development Conference brings together investigators in the biomedical sciences, clinical investigators, practicing physicians, and consumer and special interest groups to make a scientific assessment of technologies, including drugs, devices, and procedures, and to seek agreement on their safety and effectiveness

  7. Magnetic field on board

    International Nuclear Information System (INIS)

    Estevez Radio, H.; Fernandez Arenal, C.A.

    1995-01-01

    Here, the calculation of the magnetic field on board ships is performed, using matrix calculus, in a similar way as when the magnetic field in matter is studied. Thus the final formulas are written in a more compact form and they are obtained through a simpler way, more suitable for the university education. (Author)

  8. Magnetic sensor device

    NARCIS (Netherlands)

    2009-01-01

    The present invention provides a sensor device and a method for detg. the presence and/or amt. of target moieties in a sample fluid, the target moieties being labeled with magnetic or magnetizable objects. The sensor device comprises a magnetic field generating means adapted for applying a retention

  9. New permanent magnets

    Science.gov (United States)

    Müller, K.-H.; Krabbes, G.; Fink, J.; Gruß, S.; Kirchner, A.; Fuchs, G.; Schultz, L.

    2001-05-01

    Permanent magnets play an important role and are widely spread in daily-life applications. Due to their very low costs, large availability of the row materials and their high chemical stability, hard ferrites are still dominant in the permanent magnet market although their relatively poor magnetic properties are a distinct disadvantage. Today's high-performance magnets are mostly made from Nd 2Fe 14B. The aim of research is to combine the large spontaneous magnetization of 3d metals with strong anisotropy fields known from rare-earth transition-metal compounds and, at the same time, to maintain a high value of the Curie temperature. However, the number of iron-rich rare-earth intermetallics is very limited and, consequently, not much success can be noted in this field for the last 10 years. One alternative concept is to use magnetic fields trapped in type II superconductors where much higher fields can be achieved compared to conventional rare-earth magnets. Very recently, we obtained a trapped field as high as 14.4 T in a melt-textured YBCO bulk sample of a few centimeters in diameter. This is the highest value ever achieved in a bulk superconductor. The trapped field of a superconductor is not governed by the Laplace equation and, therefore, levitation works without any additional (active) stabilization. The disadvantage of these magnets is their low working temperature (of liquid nitrogen and below).

  10. The LHCb magnet

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The LHCb magnet consists of two huge 27 tonne coils mounted inside a 1450 tonne iron yoke. As charged particles pass through the magnet's field their trajectories will be bent according to their momentum, allowing their momentum to be measured as they pass through the detector walls. LHCb will study bottom quarks, which will be produced close to the two colliding proton beams.

  11. PS auxiliary magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  12. AGS Booster prototype magnets

    Energy Technology Data Exchange (ETDEWEB)

    Danby, G.; Jackson, J.; Lee, Y.Y.; Phillips, R.; Brodowski, J.; Jablonski, E.; Keohane, G.; McDowell, B.; Rodger, E.

    1987-03-19

    Prototype magnets have been designed and constructed for two half cells of the AGS Booster. The lattice requires 2.4m long dipoles, each curved by 10/sup 0/. The multi-use Booster injector requires several very different standard magnet cycles, capable of instantaneous interchange using computer control from dc up to 10 Hz.

  13. AGS booster prototype magnets

    International Nuclear Information System (INIS)

    Danby, G.; Jackson, J.; Lee, Y.Y.; Phillips, R.; Brodowski, J.; Jablonski, E.; Keohane, G.; McDowell, B.; Rodger, E.

    1987-01-01

    Prototype magnets have been designed and constructed for two half cells of the AGS Booster. The lattice requires 2.4m long dipoles, each curved by 10 0 . The multi-use Booster injector requires several very different standard magnet cycles, capable of instantaneous interchange using computer control from dc up to 10 Hz

  14. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1984-03-01

    The magnetic field line Hamiltonian and the associated canonical form for the magnetic field are important concepts both for understanding toroidal plasma physics and for practical calculations. A number of important properties of the canonical or Hamiltonian representation are derived and their importance is explained

  15. Superconducting magnets for HERA

    International Nuclear Information System (INIS)

    Wolff, S.

    1987-01-01

    The Hadron-Electron-Ring Accelerator (HERA) presently under construction at DESY, Hamburg, consists of an electron storage ring of 30 GeV and a proton storage ring of 820 GeV. Superconducting magnets are used for the proton ring. There are 416 superconducting bending magnets of 4.698 T central field and 8.824 m magnetic length, 224 superconducting quadrupoles of 91.2 T/m central gradient and many superconducting correction dipoles, quadrupoles and sextupoles. The main dipoles and quadrupoles consist of two-layer coils of 75 mm inner diameter clammed with aluminium (for the dipoles) or stainless steel laminations (for the quadrupoles). The collared coils are surrounded by a laminated cold iron yoke and supported inside a low loss cryostat. The protection system uses cold diodes to bypass the current around a quenching magnet. The magnets are cooled with one phase helium supplied by a 3 block central refrigeration system of 20 kW refrigeration power at 4.3 K. Two helium is returned through the magnets in good thermal contact with the one phase helium in the dipoles for temperature control. This paper describes the magnet system and gives the results obtained for prototype magnets

  16. Effective magnetic Hamiltonians

    Czech Academy of Sciences Publication Activity Database

    Drchal, Václav; Kudrnovský, Josef; Turek, I.

    2013-01-01

    Roč. 26, č. 5 (2013), s. 1997-2000 ISSN 1557-1939 R&D Projects: GA ČR GA202/09/0775 Institutional support: RVO:68378271 Keywords : effective magnetic Hamiltonian * ab initio * magnetic structure Subject RIV: BE - Theoretical Physics Impact factor: 0.930, year: 2013

  17. Selected topics in magnetism

    CERN Document Server

    Gupta, L C

    1993-01-01

    Part of the ""Frontiers in Solid State Sciences"" series, this volume presents essays on such topics as spin fluctuations in Heisenberg magnets, quenching of spin fluctuations by high magnetic fields, and kondo effect and heavy fermions in rare earths amongst others.

  18. One thousand magnets delivered!

    CERN Multimedia

    2005-01-01

    The little matchstick-like objects, neatly lined up like colouring pencils in their box, are in fact LHC magnets seen from the air. These particular ones are being stored at Point 19 just alongside SM18, the magnet assembly and testing hall, which can be seen on the right of the picture. On the right in the background, is the Meyrin site.

  19. MAGNETIC FIELDS OF STARS

    OpenAIRE

    Bychkov, V. D.; Bychkova, L. V.; Madej, J.

    2008-01-01

    Now it is known about 1212 stars of the main sequence and giants (from them 610 stars - it is chemically peculiarity (CP) stars) for which direct measurements of magnetic fields were spent (Bychkov et al.,2008). Let's consider, what representations were generated about magnetic fields (MT) of stars on the basis of available observations data.

  20. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  1. CERN: LHC magnets

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-08-15

    With test magnets for CERN's LHC proton-proton collider regularly attaining field strengths which show that 10 Tesla is not forbidden territory, attention turns to why and where quenches happen. If 'training' can be reduced, superconducting magnets become easier to commission.

  2. Magnetic photon scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.

    1987-05-01

    The report reviews, at an introductory level, the theory of photon scattering from condensed matter. Magnetic scattering, which arises from first-order relativistic corrections to the Thomson scattering amplitude, is treated in detail and related to the corresponding interaction in the magnetic neutron diffraction amplitude. (author)

  3. ISR magnet model

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    Field measurements being made on the ISR magnet model. In the foreground, the poleface windings can be seen - as distinct from the large exciting coils - together with their supply cables. These windings are mainly used to compensate the saturation effects at high fields. The steel plates forming the yoke are welded together along the whole length of the magnet.

  4. Magnetic-island formation

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1983-08-01

    The response of a finite conductivity plasma to resonant magnetic perturbations is studied. The equations, which are derived for the time development of magnetic islands, help one interpret the singular currents which occur under the assumption of perfect plasma conductivity. The relation to the Rutherford regime of resistive instabilities is given

  5. Passive magnetic bearing configurations

    Science.gov (United States)

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    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.

  6. Solid state magnetism

    CERN Document Server

    Crangle, John

    1991-01-01

    Solid state magnetism is important and attempts to understand magnetic properties have led to an increasingly deep insight into the fundamental make up of solids. Both experimental and theoretical research into magnetism continue to be very active, yet there is still much ground to cover before there can be a full understanding. There is a strong interplay between the developments of materials science and of magnetism. Hundreds of new materials have been dis­ covered, often with previously unobserved and puzzling magnetic prop­ erties. A large and growing technology exists that is based on the magnetic properties of materials. Very many devices used in everyday life involve magnetism and new applications are being invented all the time. Under­ standing the fundamental background to the applications is vital to using and developing them. The aim of this book is to provide a simple, up-to-date introduction to the study of solid state magnetism, both intrinsic and technical. It is designed to meet the needs a...

  7. A Magnetic Circuit Demonstration.

    Science.gov (United States)

    Vanderkooy, John; Lowe, June

    1995-01-01

    Presents a demonstration designed to illustrate Faraday's, Ampere's, and Lenz's laws and to reinforce the concepts through the analysis of a two-loop magnetic circuit. Can be made dramatic and challenging for sophisticated students but is suitable for an introductory course in electricity and magnetism. (JRH)

  8. MFTF magnet cryogenics

    International Nuclear Information System (INIS)

    VanSant, J.H.

    1981-07-01

    The prime requirement of the cryogenics of the magnets is to assure a superconducting state for the magnet coils, a large task considering their enormous size. The following presentation addresses the principal topics that have been considered in this cryogenic design

  9. TMX magnets: mechanical design

    International Nuclear Information System (INIS)

    Hinkle, R.E.; Harvey, A.R.; Calderon, M.O.; Chargin, A.K.; Chen, F.F.K.; Denhoy, B.S.; Horvath, J.A.; Reed, J.R.; Waugh, A.F.

    1977-01-01

    The Tandem Mirror Experiment (TMX) system, part of the Lawrence Livermore Laboratory magnetic mirror program incorporates in its design various types of coils or magnets. This paper describes the physical construction of each coil within the system as well as the structural design required for their support and installation

  10. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

  11. Magnetic Particle Technology

    Science.gov (United States)

    Oliveira, Luiz C.A.; A. Rios, Rachel V.R.; Fabris, Jose D.; Lago, Rachel M.; Sapag, Karim

    2004-01-01

    An exciting laboratory environment is activated by the preparation and novel use of magnetic materials to decontaminate water through adsorption and magnetic removal of metals and organics. This uncomplicated technique is also adaptable to the possible application of adsorbents to numerous other environmental substances.

  12. Magnetic entropy and cooling

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl; Kuhn, Luise Theil; Bahl, Christian Robert Haffenden

    2010-01-01

    Some manifestations of magnetism are well-known and utilized on an everyday basis, e.g. using a refrigerator magnet for hanging that important note on the refrigerator door. Others are, so far, more exotic, such as cooling by making use of the magnetocaloric eect. This eect can cause a change...... in the temperature of a magnetic material when a magnetic eld is applied or removed. For many years, experimentalists have made use of dilute paramagnetic materials to achieve milliKelvin temperatures by use of the magnetocaloric eect. Also, research is done on materials, which might be used for hydrogen, helium...... or nitrogen liquefaction or for room-temperature cooling. The magnetocaloric eect can further be used to determine phase transition boundaries, if a change in the magnetic state occurs at the boundary.In this talk, I will introduce the magnetocaloric eect (MCE) and the two equations, which characterize...

  13. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  14. Physics of magnetic nanostructures

    CERN Document Server

    Owens, Frank J

    2015-01-01

    This book discusses how the important properties of materials such as the cohesive energy, and the electronic and vibrational structures are affected when materials have at least one length in the nanometer range. The author uses relatively simple models of the solid state to explain why these changes in the size and dimension in the nanometer regime occur. The text also reviews the physics of magnetism and experimental methods of measuring magnetic properties necessary to understanding how nanosizing affects magnetism. Various kinds of magnetic structures are presented by the author in order to explain how nanosizing influences their magnetic properties. The book also presents potential and actual applications of nanomaterials in the fields of medicine and computer data storage.

  15. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  16. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  17. The ELETTRA fast magnets

    International Nuclear Information System (INIS)

    Tommasini, D.

    1992-01-01

    The design of the fast magnets to be used to inject the electron beam into the 2 GeV storage ring Elettra is presented and discussed. Injection makes use of two types of fast magnets: the septa and the kickers. There are two identical septa magnets of the so called 'eddy current' type, which will be housed in a vacuum tank. The orbit bump is generated by four identical kicker magnets symmetrically placed around the mid-point of a single straight section: they will be in air with an internal vacuum chamber. Extensive electric and magnetic tests have been performed on prototypes, and the relevant results are presented and discussed. (author) 6 refs.; 6 figs.; 2 tabs

  18. Hybrid Magnetic Shielding

    Science.gov (United States)

    Royal, Kevin; Crawford, Christopher; Mullins, Andrew; Porter, Greg; Blanton, Hunter; Johnstone, Connor; Kistler, Ben; Olivera, Daniela

    2017-09-01

    The search for the electric dipole moment of the neutron requires the ambient magnetic field to be on the pT scale which is accomplished with large magnetic shielding rooms. These rooms are fitted with large mu-metal sheets to allow for passive cancellation of background magnetic fields. Active shielding technology cannot uniformly cancel background magnetic fields. These issues can be remedied by combining the methods into a hybrid system. The design used is composed of panels that have an active layer of cancellation between two sheets of mu-metal. The panels form a cube and draw in magnetic fields perpendicular to the surface which can then be reduced using active shielding. This work is supported by the Department of Energy under Contract DE-SC0008107.

  19. Chiral Magnetic Spirals

    International Nuclear Information System (INIS)

    Basar, Goekce; Dunne, Gerald V.; Kharzeev, Dmitri E.

    2010-01-01

    We argue that the presence of a very strong magnetic field in the chirally broken phase induces inhomogeneous expectation values, of a spiral nature along the magnetic field axis, for the currents of charge and chirality, when there is finite baryon density or an imbalance between left and right chiralities. This 'chiral magnetic spiral' is a gapless excitation transporting the currents of (i) charge (at finite chirality), and (ii) chirality (at finite baryon density) along the direction of the magnetic field. In both cases it also induces in the transverse directions oscillating currents of charge and chirality. In heavy ion collisions, the chiral magnetic spiral possibly provides contributions both to the out-of-plane and the in-plane dynamical charge fluctuations recently observed at BNL RHIC.

  20. Continuous magnetic flux pump

    Science.gov (United States)

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A method and means for altering the intensity of a magnetic field by transposing flux from one location to the location desired fro the magnetic field are examined. The device described includes a pair of communicating cavities formed in a block of superconducting material, is dimensioned to be insertable into one of the cavities and to substantially fill the cavity. Magnetic flux is first trapped in the cavities by establishing a magnetic field while the superconducting material is above the critical temperature at which it goes superconducting. Thereafter, the temperature of the material is reduced below the critical value, and then the exciting magnetic field may be removed. By varying the ratios of the areas of the two cavities, it is possible to produce a field having much greater flux density in the second, smaller cavity, into which the flux transposed.

  1. Superconducting magnets for ISABELLE

    International Nuclear Information System (INIS)

    Sampson, W.B.

    1976-01-01

    The application of superconducting magnet technology to high-energy accelerators has been studied at BNL for many years. Recently this effort has focused on the magnet system for the proposed Intersecting Storage Accelerator, ISABELLE. Several full-sized dipole and quadrupole magnets were fabricated and tested. A dipole was successfully operated using a high pressure forced circulation refrigeration system similar to that proposed for the accelerator. This magnet reached a maximum central field of 4.9 T, considerably above the design field of 3.9 T. A quadrupole of similar design was equally successful, achieving a gradient of 71 T/m compared to the design value of 53 T/m. A summary is given of the present status of the magnet development program, and the direction of future work is outlined

  2. Magnet pole tips

    Science.gov (United States)

    Thorn, Craig E.; Chasman, Chellis; Baltz, Anthony J.

    1984-04-24

    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.

  3. GHz nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.; Drobny, G.; Trewhella, J.

    1994-12-01

    For the past dozen years, 500- and 600-MHz spectrometers have become available in many laboratories. The first 600-MHz NMR spectrometer (at Carnegie Mellon University) was commissioned more than 15 years ago and, until 1994, represented the highest field available for high-resolution NMR. This year, we have witnessed unprecedented progress in the development of very high field magnets for NMR spectroscopy, including the delivery of the first commercial 750-MHz NMR spectrometers. In addition, NMR signals have been obtained from 20-Tesla magnets (850 MHz for {sup 1}H`s) at both Los Alamos National Laboratory and Florida State University in the NHMFL (National High Magnetic Field Laboratory). These preliminary experiments have been performed in magnets with 100-ppm homogeneity, but a 20-Tesla magnet developed for the NHMFL will be brought to field this year with a projected homogeneity of 0.1 ppm over a 1-cm-diam spherical volume.

  4. Magnetic diffuse scattering

    International Nuclear Information System (INIS)

    Cable, J.W.

    1987-01-01

    The diffuse scattering of neutrons from magnetic materials provides unique and important information regarding the spatial correlations of the atoms and the spins. Such measurements have been extensively applied to magnetically ordered systems, such as the ferromagnetic binary alloys, for which the observed correlations describe the magnetic moment fluctuations associated with local environment effects. With the advent of polarization analysis, these techniques are increasingly being applied to study disordered paramagnetic systems such as the spin-glasses and the diluted magnetic semiconductors. The spin-pair correlations obtained are essential in understanding the exchange interactions of such systems. In this paper, we describe recent neutron diffuse scattering results on the atom-pair and spin-pair correlations in some of these disordered magnetic systems. 56 refs

  5. Great magnetic storms

    International Nuclear Information System (INIS)

    Tsurutani, B.T.; Yen Te Lee; Tang, F.; Gonzalez, W.D.

    1992-01-01

    The five largest magnetic storms that occurred between 1971 and 1986 are studied to determine their solar and interplanetary causes. All of the events are found to be associated with high speed solar wind streams led by collisionless shocks. The high speed streams are clearly related to identifiable solar flares. It is found that (1) it is the extreme values of the southward interplanetary magnetic fields rather than solar wind speeds that are the primary causes of great magnetic storms, (2) shocked and draped sheath fields preceding the driver gas (magnetic cloud) are at least as effective in causing the onset of great magnetic storms (3 of 5 events ) as the strong fields within the driver gas itself, and (3) precursor southward fields ahead of the high speed streams allow the shock compression mechanism (item 2) to be particularly geoeffective

  6. Metallic Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Hernando

    2005-01-01

    Full Text Available In this paper, we reviewed some relevant aspects of the magnetic properties of metallic nanoparticles with small size (below 4 nm, covering the size effects in nanoparticles of magnetic materials, as well as the appearance of magnetism at the nanoscale in materials that are nonferromagnetic in bulk. These results are distributed along the text that has been organized around three important items: fundamental magnetic properties, different fabrication procedures, and characterization techniques. A general introduction and some experimental results recently obtained in Pd and Au nanoparticles have also been included. Finally, the more promising applications of magnetic nanoparticles in biomedicine are indicated. Special care was taken to complete the literature available on the subject.

  7. Magnetic particle inspection

    Science.gov (United States)

    Sastri, Sankar

    1990-01-01

    The purpose of this experiment is to familiarize the student with magnetic particle inspection and relate it to classification of various defects. Magnetic particle inspection is a method of detecting the presence of cracks, laps, tears, inclusions, and similar discontinuities in ferromagnetic materials such as iron and steel. This method will most clearly show defects that are perpendicular to the magnetic field. The Magnaglo method uses a liquid which is sprayed on the workpiece to be inspected, and the part is magnetized at the same time. The workpiece is then viewed under a black light, and the presence of discontinuity is shown by the formation of a bright indication formed by the magnetic particles over the discontinuity. The equipment and experimental procedures are described.

  8. Halbach Magnets for CBETA

    Energy Technology Data Exchange (ETDEWEB)

    Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-30

    A principle of the non-scaling Fixed Field Alternating Gradient (NS-FFAG) is that different energy beam has orbit oscillations Δx around the central circular orbit in both positive and negative direction within a small radial aperture as: Δx=Dx*δp/p. For the central circular orbit Δx=0, or for the combined function magnets the field is equal to Bo (B (x) = Bo + G*x). The smallest orbit offsets Δx are obtained when the defocusing magnet provides most of the bending for the central energy, while the focusing magnet could be even the regular quadrupole with the central orbit in the middle. Stable orbits for a very large energy range [in the case of CBETA this is 4 times in energy], is obtained using opposite polarity magnets producing linear magnetic fields, small dispersion, and very strong focusing.

  9. Halbach Magnets for CBETA

    Energy Technology Data Exchange (ETDEWEB)

    Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-01-19

    A principle of the non-scaling Fixed Field Alternating Gradient (NS-FFAG) is that different energy beam has orbit oscillations Δx around the central circular orbit in both positive and negative direction within a small radial aperture as: Δx=Dx*δp/p. For the central circular orbit Δx=0, or for the combined function magnets the field is equal to Bo (B (x) = Bo + G* x). The smallest orbit offsets Δx are obtained when the defocusing magnet provides most of the bending for the central energy, while the focusing magnet could be even the regular quadrupole with the central orbit in the middle. Stable orbits for a very large energy range [in the case of CBETA this is 4 times in energy], is obtained using opposite polarity magnets producing linear magnetic fields, small dispersion, and very strong focusing.

  10. Nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Ethier, R.; Melanson, D.; Peters, T.M.

    1983-01-01

    Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr

  11. The magnetic properties of the hollow cylindrical ideal remanence magnet

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

    2016-01-01

    We consider the magnetic properties of the hollow cylindrical ideal remanence magnet. This magnet is the cylindrical permanent magnet that generates a uniform field in the cylinder bore, using the least amount of magnetic energy to do so. The remanence distribution of this magnet is derived...... and the generated field is compared to that of a Halbach cylinder of equal dimensions. The ideal remanence magnet is shown in most cases to generate a significantly lower field than the equivalent Halbach cylinder, although the field is generated with higher efficiency. The most efficient Halbach cylinder is shown...... to generate a field exactly twice as large as the equivalent ideal remanence magnet....

  12. Magnetic separation of antibiotics by electrochemical magnetic seeding

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, I; Toyoda, K [Department of Agricultural Engineering and Socio Economics, Kobe University, Nada, Kobe 657-8501 (Japan); Beneragama, N; Umetsu, K [Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan)

    2009-03-01

    Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

  13. Magnetic separation of antibiotics by electrochemical magnetic seeding

    International Nuclear Information System (INIS)

    Ihara, I; Toyoda, K; Beneragama, N; Umetsu, K

    2009-01-01

    Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

  14. Nanoparticulated magnetic drug delivery systems: Preparation and magnetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Morais, P C, E-mail: pcmor@unb.b [Universidade de BrasIlia, Instituto de Fisica, Nucleo de Fisica Aplicada, Brasilia DF 70910-900 (Brazil)

    2010-03-01

    This paper describes how magnetic resonance can be successfully used as a tool to help customize and quantify nanosized magnetic particles while labeling cells and administered in animals for targeting different biological sites. Customization of magnetic nanoparticles is addressed here in terms of production of complex magnetic drug delivery systems whereas quantification of magnetic nanoparticle in different biological compartments emerges as a key experimental information to assess time-dependent magnetic nanoparticle biodistribution profiles. Examples of using magnetic resonance in unfolding information regarding the pharmacokinetics of intravenously-injected surface-functionalized magnetic nanoparticles in animals are included in the paper.

  15. Standard Wiggler magnets

    International Nuclear Information System (INIS)

    Winick, H.; Helm, R.H.

    1977-09-01

    Interest in Wiggler magnets (a close sequence of transverse fields with alternating polarity) to extend and enhance the spectrum of synchrotron radiation from electron storage rings has increased significantly during the past few years. Standard wigglers, i.e., wigglers in which interference effects on the spectrum of synchrotron radiation are not important, are considered. In standard wigglers the spectrum of synchrotron radiation has the same general shape as the spectrum from ring bending magnets. However, the critical energy of the wiggler spectrum may be different. The critical energy of the wiggler spectrum is given by epsilon/sub CW/ = epsilon/sub CB/(B/sub W//B/sub B/) where epsilon/sub CB/ is the critical energy from the bending magnets and B/sub W/ and B/sub B/ are the magnetic field strengths of the wiggler magnet and bending magnets respectively. Since most electron storage rings operate with relatively low bending magnet fields (B/sub B/ less than or equal to 12 kG), even a modest wiggler magnet field (less than or equal to 18 kG) can significantly increase the critical energy. Such magnets are planned for ADONE and SPEAR. Higher field (30 to 50 kG) superconducting magnets are planned at Brookhaven, Daresbury, and Novosibirsk to produce even larger increase in the critical energy. For some standard wigglers a further enhancement of the spectrum is produced due tothe superposition of the radiation from the individual poles. Wiggler designs are discussed as well as the effect of wigglers on the synchrotron radiation spectrum and on the operation of storage rings

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  17. Orbital studies of lunar magnetism

    Science.gov (United States)

    Mcleod, M. G.; Coleman, P. J., Jr.

    1982-01-01

    Limitations of present lunar magnetic maps are considered. Optimal processing of satellite derived magnetic anomaly data is also considered. Studies of coastal and core geomagnetism are discussed. Lunar remanent and induced lunar magnetization are included.

  18. Magnetization processes in thin magnetic wires

    International Nuclear Information System (INIS)

    Varga, R.; Garcia, K.L.; Zhukov, A.; Vazquez, M.; Ipatov, M.; Gonzalez, J.; Zhukova, V.; Vojtanik, P.

    2006-01-01

    Amorphous magnetic microwires are novel materials, which are characterized by the unique magnetic properties. Their magnetization process runs through the depining and subsequent propagation of the single-domain wall. This allows us to study the magnetization processes of the single-domain wall either in static (when the domain wall lies in its potential) or dynamic (when the domain wall propagates along the wire) mode. In the given work, we present surprising results that were found during the single-domain wall switching and propagation in microwires. The negative critical propagation field during the propagation of the single-domain wall in microwires has been found. Moreover, new contribution (based on the structural relaxation) to the domain wall damping during its propagation in microwire was found. The complex shape of the single-domain wall potential, which consists of two contributions, has been found in microwires. The magnetoelastic one coming from the magnetoelastic interaction of the domain wall with the stresses applied on microwires and the stresses introduced during the microwire's production and stabilization one coming from the structural relaxation on atomic level

  19. Magnetically Coupled Magnet-Spring Oscillators

    Science.gov (United States)

    Donoso, G.; Ladera, C. L.; Martin, P.

    2010-01-01

    A system of two magnets hung from two vertical springs and oscillating in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled oscillators. The electromagnetically coupled oscillations of these oscillators are experimentally and theoretically studied. Its coupling is electromagnetic instead of…

  20. Magnetic measurements inside the Omicron magnet.

    CERN Multimedia

    1977-01-01

    The multipurpose detection system (Omicron) built at the SC in the late seventies in the Proton Hall made use of the large aperture magnet (on loan from Rutherford Lab, 85 cm gap height, 1 m width, 1.8 m length, 1 Tesla peak field). See CERN Courier 17 (1977) p. 61.

  1. Review of Micro Magnetic Generator

    OpenAIRE

    Lin DU; Gengchen SHI; Jingjing ZHAO

    2014-01-01

    This paper discusses the research progress of micro magnetic generator systems. Micro magnetic generator systems convert energy from the environment to electric energy with advantages as high reliability, high power density, long life time and can be applied to extreme environment. This paper summarizes methods for improving generator performance of micro magnetic generator, including rotational magnetic generator, vibrational magnetic generator and hybrid magnetic generator, analyzes and com...

  2. Active Magnetic Regenerative Liquefier

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, John A. [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Oseen-Send, Kathryn [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Ferguson, Luke [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Pouresfandiary, Jamshid [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Cousins, Anand [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Ralph, Heather [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Hampto, Tom [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States)

    2016-01-12

    This final report for the DOE Project entitled Active Magnetic Regenerative Liquefier (AMRL) funded under Grant DE-FG36-08GO18064 to Heracles Energy Corporation d.b.a. Prometheus Energy (Heracles/Prometheus) describes an active magnetic regenerative refrigerator (AMRR) prototype designed and built during the period from July 2008 through May 2011. The primary goal of this project was to make significant technical advances toward highly efficient liquefaction of hydrogen. Conventional hydrogen liquefiers at any scale have a maximum FOM of ~0.35 due primarily to the intrinsic difficulty of rapid, efficient compression of either hydrogen or helium working gases. Numerical simulation modeling of high performance AMRL designs indicates certain designs have promise to increase thermodynamic efficiency from a FOM of ~0.35 toward ~0.5 to ~0.6. The technical approach was the use of solid magnetic working refrigerants cycled in and out of high magnetic fields to build an efficient active regenerative magnetic refrigeration module providing cooling power for AMRL. A single-stage reciprocating AMRR with a design temperature span from ~290 K to ~120 K was built and tested with dual magnetic regenerators moving in and out of the conductively-cooled superconducting magnet subsystem. The heat transfer fluid (helium) was coupled to the process stream (refrigeration/liquefaction load) via high performance heat exchangers. In order to maximize AMRR efficiency a helium bypass loop with adjustable flow was incorporated in the design because the thermal mass of magnetic refrigerants is higher in low magnetic field than in high magnetic field. Heracles/Prometheus designed experiments to measure AMRR performance under a variety of different operational parameters such as cycle frequency, magnetic field strength, heat transfer fluid flow rate, amount of bypass flow of the heat transfer fluid while measuring work input, temperature span, cooling capability as a function of cold temperature

  3. Review and comparison of magnet designs for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

    One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving...... the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated...... and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, Λcool. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis...

  4. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    to facilitate real-time monitoring of the experiments. The set-up and experimental protocol are described in detail. Results are presented for ’active’ magnetic bead separators, where on-chip microfabricated electromagnets supply the magnetic field and field gradients necessary for magnetic bead separation....... It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside...

  5. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

  6. Magnetism a very short introduction

    CERN Document Server

    Blundell, Stephen J

    2012-01-01

    Magnetism: A Very Short Introduction explains the mysteries and importance of magnetism. For centuries magnetism has been used for various exploits: as a great healer, a navigation aid through compasses, and through motors, generators, and turbines it has given us power. Our understanding of electricity and magnetism, from the work of Galvani, Ampère, Faraday, and Tesla is explored, and how Maxwell and Faraday's work led to the unification of electricity and magnetism is explained. With a discussion of the relationship between magnetism and relativity, quantum magnetism, and its impact on computers and information storage, how magnetism has changed our fundamental understanding of the Universe is shown.

  7. Investigations on the magnetization behavior of magnetic composite particles

    Energy Technology Data Exchange (ETDEWEB)

    Eichholz, Christian [Process Research and Chemical Engineering, BASF SE, Ludwigshafen (Germany); Knoll, Johannes, E-mail: johannes.knoll@kit.edu [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Lerche, Dietmar [L.U.M. GmbH, Berlin (Germany); Nirschl, Hermann [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2014-11-15

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data.

  8. Investigations on the magnetization behavior of magnetic composite particles

    International Nuclear Information System (INIS)

    Eichholz, Christian; Knoll, Johannes; Lerche, Dietmar; Nirschl, Hermann

    2014-01-01

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data

  9. Superposition of DC magnetic fields by cascading multiple magnets in magnetic loops

    Directory of Open Access Journals (Sweden)

    Fei Sun

    2015-09-01

    Full Text Available A novel method that can effectively collect the DC magnetic field produced by multiple separated magnets is proposed. With the proposed idea of a magnetic loop, the DC magnetic field produced by these separated magnets can be effectively superimposed together. The separated magnets can be cascaded in series or in parallel. A novel nested magnetic loop is also proposed to achieve a higher DC magnetic field in the common air region without increasing the DC magnetic field in each magnetic loop. The magnetic loop can be made by a magnetic hose, which is designed by transformation optics and can be realized by the combination of super-conductors and ferromagnetic materials.

  10. MAGNETIC CIRCUIT EQUIVALENT OF THE SYNCHRONOUS MOTOR WITH INCORPORATED MAGNETS

    Directory of Open Access Journals (Sweden)

    Fyong Le Ngo

    2015-01-01

    Full Text Available Magnetic circuitry computation is one of the central stages of designing a synchronous motor with incorporated magnets, which can be performed by means of a simplified method of the magnetic-circuits equivalent modeling. The article studies the magnetic circuit of the motor with the rotor-incorporated magnets, which includes four sectors: constant magnets with the field pole extension made of magnetically soft steel, magniflux dispersion sections containing air barriers and steel bridges; the air gap; the stator grooves, cogs and the frame yoke. The authors introduce an equivalent model of the magnetic circuit. High-energy magnets with a linear demagnetization curve are employed in the capacity of constant magnets. Two magnets create the magnetic flux for one pole. The decline of magnetic potential in the steel of the pole is negligible consequent on the admission that the poles magnetic inductivity µ = ∞. The rotor design provides for the air barriers and the steel bridges that close leakage flux. The induction-permeability curve linearization serves for the bridges magnetic saturation accountability and presents a polygonal line consisting of two linear sections. The estimation of the magnet circuit section including the cogs and the frame yoke is executed with account of the steel saturation, their magnetic conductivities thereat being dependent on the saturation rate. Relying on the equivalent model of the magnetic circuit, the authors deduce a system of two equations written from the first and the second Kirchhoff laws of the magnetic circuits. These equations allow solving two problems: specifying dimensions of the magnets by the preset value of the magnetic flow in the clearance and determining the clearance magnetic flow at the preset motor rotor-and-stator design.

  11. TPC magnet cryogenic system

    International Nuclear Information System (INIS)

    Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

    1980-03-01

    The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system

  12. TMX magnet control system

    International Nuclear Information System (INIS)

    Goerz, D.A.

    1978-01-01

    A control system utilizing a microcomputer has been developed that controls the power supplies driving the Tandem Mirror Experiment (TMX) magnet set and monitors magnet coil operation. The magnet set consists of 18 magnet coils that are driven by 26 dc power supplies. There are two possible modes of operation with this system: a pulse mode where the coils are pulsed on for several seconds with a dc power consumption of 16 MW; and a continuous mode where the coils can run steady state at 10 percent of maximum current ratings. The processor has been given an active control role and serves as an interface between the operator and electronic circuitry that controls the magnet power supplies. This microcomputer also collects and processes data from many analog singal monitors in the coil circuits and numerous status signals from the supplies. Placing the microcomputer in an active control role has yielded a compact, cost effective system that simplifies the magnet system operation and has proven to be very reliable. This paper will describe the TMX magnet control sytem and discuss its development

  13. High energy magnetic excitations

    International Nuclear Information System (INIS)

    Endoh, Yasuo

    1988-01-01

    The report emphasizes that the current development in condensed matter physics opens a research field fit to inelastic neutron scattering experiments in the eV range which is easilly accessed by spallation neutron sources. Several important subjects adopted at thermal reactors are shown. It is desired to extend the implementation of the spectroscopic experiments for investigation of higher energy magnetic excitations. For La 2 CuO 4 , which is the mother crystal of the first high Tc materials found by Bednortz and Muller, it seems to be believed that the magnetism is well characterized by the two-dimensional Heisenberg antiferromagnetic Hamiltonian, and it is widely accepted that the magnetism is a most probable progenitor of high Tc superconductors. The unusual properties of spin correlations in this crystal have been studied extensively by standard neutron scattering techniques with steady neutrons at BNL. FeSi is not ordered magnetically but shows a very unique feature of temperature induced magnetism, which also has been studied extensively by using the thermal neutron scattering technique at BNL. In these experiments, polarized neutrons are indispensable to extract the clean magnetic components out of other components of non-magnetic scattering. (N.K.)

  14. Magnetic Coordinate Systems

    Science.gov (United States)

    Laundal, K. M.; Richmond, A. D.

    2017-03-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  15. Magnetic vortex racetrack memory

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Liwei D.; Jin, Yongmei M., E-mail: ymjin@mtu.edu

    2017-02-01

    We report a new type of racetrack memory based on current-controlled movement of magnetic vortices in magnetic nanowires with rectangular cross-section and weak perpendicular anisotropy. Data are stored through the core polarity of vortices and each vortex carries a data bit. Besides high density, non-volatility, fast data access, and low power as offered by domain wall racetrack memory, magnetic vortex racetrack memory has additional advantages of no need for constrictions to define data bits, changeable information density, adjustable current magnitude for data propagation, and versatile means of ultrafast vortex core switching. By using micromagnetic simulations, current-controlled motion of magnetic vortices in cobalt nanowire is demonstrated for racetrack memory applications. - Highlights: • Advance fundamental knowledge of current-driven magnetic vortex phenomena. • Report appealing new magnetic racetrack memory based on current-controlled magnetic vortices in nanowires. • Provide a novel approach to adjust current magnitude for data propagation. • Overcome the limitations of domain wall racetrack memory.

  16. Magnetic Exitations in Praseodymium

    DEFF Research Database (Denmark)

    Houmann, Jens Christian Gylden; Rainford, B. D.; Jensen, J.

    1979-01-01

    The magnetic excitations in a single crystal of dhcp Pr have been studied by inelastic neutron scattering. The excitations on the hexagonal sites, and their dependence on magnetic fields up to 43 kOe applied in the basal plane, have been analyzed in terms of a Hamiltonian in which exchange, crystal......-field, and magnetoelastic interactions are included. The exchange is found to be strongly anisotropic, and this anisotropy is manifested directly in a splitting of most branches of the dispersion relations. By considering a variety of magnetic properties, we have been able to determine the crystal-field level scheme...

  17. Low Current Magnet

    Science.gov (United States)

    1992-01-01

    Because Goddard Space Flight Center needed a way to cool sensors aboard the AXAF, a low current superconducting magnet was developed under contract by Cryomagnetics, Inc. The magnet, now commercially available, reduced the rate of helium consumption, extending the lifetime of the AXAF's x-ray spectrometer. On Earth, it offers a way to reduce operating costs through smaller, less expensive power supplies and reduced use of coolant. The magnet has particular advantages for MRI systems, as it is safer and has lower maintenance requirements.

  18. A paradigm called magnetism

    CERN Document Server

    Dattagupta, Sushanta

    2008-01-01

    This book provides an overview of how diverse issues of Magnetism have implications for other areas of physics. Attention will be drawn to different aspects of many-body physics, which first appeared in Magnetism but have had deep impact in different branches of physics. Each of these aspects will be illustrated schematically and in terms of physical examples, chosen from multicritical phenomena, quantum phase transition, spin glasses, relaxation, phase ordering and quantum dissipation. A unique feature of this book is a unified and coherent discussion of magnetic phenomena, presented in a luc

  19. Magnetic separations in biotechnology.

    Science.gov (United States)

    Borlido, L; Azevedo, A M; Roque, A C A; Aires-Barros, M R

    2013-12-01

    Magnetic separations are probably one of the most versatile separation processes in biotechnology as they are able to purify cells, viruses, proteins and nucleic acids directly from crude samples. The fast and gentle process in combination with its easy scale-up and automation provide unique advantages over other separation techniques. In the midst of this process are the magnetic adsorbents tailored for the envisioned target and whose complex synthesis spans over multiple fields of science. In this context, this article reviews both the synthesis and tailoring of magnetic adsorbents for bioseparations as well as their ultimate application. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Frontiers in Magnetic Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Magnetic Materials focuses on the current achievements and state-of-the-art advancements in magnetic materials. Several lines of development- High-Tc Superconductivity, Nanotechnology and refined experimental techniques among them – raised knowledge and interest in magnetic materials remarkably. The book comprises 24 chapters on the most relevant topics written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students.

  1. Development of magnetic materials

    International Nuclear Information System (INIS)

    Bar'yakhtar, V.

    2000-01-01

    In the paper are presented both experimental and theoretical basic results of physics of magnetic materials. The special attention is given to a problem of creation of magnetic materials for recording and reproduction of the information. The influence of fundamental scientific results on process of creation of materials with the given properties and constriction of devices and facilities of new generation, and return influence of financing of scientific researches on process of discovering of new unknown fundamental properties of magnetic materials is considered. (author)

  2. MFTF magnet cryostability

    International Nuclear Information System (INIS)

    VanSant, J.H.

    1979-01-01

    A pair of large superconducting magnets will be installed in the Mirror Fusion Test Facility (MFTF), which is to begin operation in 1981. To ensure a stable superconducting state for the niobium-titanium (Nb-Ti) conductor, special consideration has been given to certain aspects of the magnet system design. These include the conductor, joints, coil assembly, vapor plenums, liquid-helium (LHe) supply system, and current leads. Heat transfer is the main consideration; i.e., the helium quality and temperature are limited so that the superconductor will perform satisfactorily in the magnet environment

  3. Magnetic-seeding filtration

    International Nuclear Information System (INIS)

    Depaoli, D.

    1996-01-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes

  4. Numerical analysis of thermally actuated magnets for magnetization of superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Li Quan; Yan Yu; Rawlings, Colin; Coombs, Tim, E-mail: ql229@cam.ac.u [EPEC Superconductivity Group, Engineering Department, University of Cambridge, Trumpington Street. Cambridge, CB2 1PZ (United Kingdom)

    2010-06-01

    Superconductors, such as YBCO bulks, have extremely high potential magnetic flux densities, comparing to rare earth magnets. Therefore, the magnetization of superconductors has attracted broad attention and contribution from both academic research and industry. In this paper, a novel technique is proposed to magnetize superconductors. Unusually, instead of using high magnetic fields and pulses, repeatedly magnetic waves with strength of as low as rare earth magnets are applied. These magnetic waves, generated by thermally controlling a Gadolinium (Gd) bulk with a rare earth magnet underneath, travel over the flat surface of a YBCO bulk and get trapped little by little. Thus, a very small magnetic field can be used to build up a very large magnetic field. In this paper, the modelling results of thermally actuated magnetic waves are presented showing how to transfer sequentially applied thermal pulses into magnetic waves. The experiment results of the magnetization of YBCO bulk are also presented to demonstrate how superconductors are progressively magnetized by small magnetic field

  5. Effective magnetic moment of neutrinos in strong magnetic fields

    International Nuclear Information System (INIS)

    Perez M, A.; Perez R, H.; Masood, S.S.; Gaitan, R.; Rodriguez R, S.

    2002-01-01

    In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)

  6. MAGNETIC VISCOSITY IN NdFeB MAGNETS

    OpenAIRE

    Martinez , J.; Missell , F.

    1988-01-01

    The relaxation of the magnetization is calculated for isotropic and anisotropic magnets. For NdFeB magnets, the dependence of Sv on texture, above room temperature, is roughly consistent with the model, while the NdDyFeB magnets show no dependence upon texture.

  7. Numerical analysis of thermally actuated magnets for magnetization of superconductors

    International Nuclear Information System (INIS)

    Li Quan; Yan Yu; Rawlings, Colin; Coombs, Tim

    2010-01-01

    Superconductors, such as YBCO bulks, have extremely high potential magnetic flux densities, comparing to rare earth magnets. Therefore, the magnetization of superconductors has attracted broad attention and contribution from both academic research and industry. In this paper, a novel technique is proposed to magnetize superconductors. Unusually, instead of using high magnetic fields and pulses, repeatedly magnetic waves with strength of as low as rare earth magnets are applied. These magnetic waves, generated by thermally controlling a Gadolinium (Gd) bulk with a rare earth magnet underneath, travel over the flat surface of a YBCO bulk and get trapped little by little. Thus, a very small magnetic field can be used to build up a very large magnetic field. In this paper, the modelling results of thermally actuated magnetic waves are presented showing how to transfer sequentially applied thermal pulses into magnetic waves. The experiment results of the magnetization of YBCO bulk are also presented to demonstrate how superconductors are progressively magnetized by small magnetic field

  8. Connection between microstructure and magnetic properties of soft magnetic materials

    International Nuclear Information System (INIS)

    Bertotti, G.

    2008-01-01

    The magnetic behavior of soft magnetic materials is discussed with some emphasis on the connection between macroscopic properties and underlying micromagnetic energy aspects. It is shown that important conceptual gaps still exist in the interpretation of macroscopic magnetic properties in terms of the micromagnetic formulation. Different aspects of hysteresis modeling, power loss prediction and magnetic non-destructive evaluation are discussed in this perspective

  9. Magnetic shielding for coreless linear permanent magnet motors

    NARCIS (Netherlands)

    Pluk, K.J.W.; Jansen, J.W.; Lomonova, E.

    2013-01-01

    This paper concerns the local reduction of the magnetic flux density by means of magnetic shielding. Using a spatial frequency description, a 2-D semi-analytical periodic model is obtained for a coreless single-sided linear permanent magnet motor. The magnetic shield is included in the modeling

  10. Relaxation of the magnetization in magnetic molecules

    Science.gov (United States)

    Carretta, S.; Bianchi, A.; Liviotti, E.; Santini, P.; Amoretti, G.

    2006-04-01

    Several mechanisms characterize the relaxation dynamics in magnetic molecules. We investigate two of them, spin-lattice coupling and incoherent quantum tunneling. The effect of the phonon heat bath is studied by analyzing the exponential time decay of the autocorrelation of the magnetization. We show that in ferromagnetic (Cu6) and antiferromagnetic (Fe6) molecular rings this decay is characterized by a single characteristic time. At very low temperature, relaxation through incoherent quantum tunneling may occur in nanomagnets such as Fe8 or Ni4. The mixing between levels with different values of the total spin (S mixing) greatly influences this mechanism. In particular, we demonstrate that a fourth-order anisotropy term O44, required to interpret experimental electron paramagnetic resonance and relaxation data in Ni4, naturally arises when S mixing is considered in calculations.

  11. Behaviour of magnetic superconductors in a magnetic field

    International Nuclear Information System (INIS)

    Buzdin, A.I.

    1984-01-01

    The behaviour of magnetic superconductors with close ferromagnetic and superconducting transition temperatures in a magnetic field is considered. It is shown that on lowering of the temperature the superconducting transition changes from a second to first order transition. The respective critical fields and dependence of the magnetization on the magnetic field and temperature are found. The magnetization discontinuity in the vortex core in magnetic superconductors is noted. Due to this property and the relatively large scattering cross section, magnetic superconductors are convenient for studying the superconducting vortex lattice by neutron diffraction techniques

  12. Generating the optimal magnetic field for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Insinga, Andrea Roberto; Smith, Anders

    2016-01-01

    In a magnetic refrigeration device the magnet is the single most expensive component, and therefore it is crucially important to ensure that an effective magnetic field as possible is generated using the least amount of permanent magnets. Here we present a method for calculating the optimal...... remanence distribution for any desired magnetic field. The method is based on the reciprocity theorem, which through the use of virtual magnets can be used to calculate the optimal remanence distribution. Furthermore, we present a method for segmenting a given magnet design that always results...... in the optimal segmentation, for any number of segments specified. These two methods are used to determine the optimal magnet design of a 12-piece, two-pole concentric cylindrical magnet for use in a continuously rotating magnetic refrigeration device....

  13. Magnetic leakage shield of septum magnet for SPring-8 synchrotron

    International Nuclear Information System (INIS)

    Abe, Hiroshi; Aoki, Tsuyoshi; Fukami, Kenji

    1997-01-01

    This paper describes magnetic field measurements of the prototype septum magnet and countermeasure for reducing the leakage magnetic fields in the incidence and the extraction parts of the SPring-8 synchrotron. We studied and developed 'leakage magnetic shield' on the basis of the tests data got in these measurements. Consequentially, it succeeded in reducing effects of the leakage field to about 50% by installing the shield board in the magnet main body. Then, it was possible to manufacture the magnet which sufficiently held the effect of the leakage field for the electron and positron beam. In this examination, we confirmed the reproduction with the magnetic field distribution of the magnet measured in the manufacturer. We developed and produced of the septum magnets which were carried out determination of the shapes of the magnetic shielding. (author)

  14. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  15. Last PS magnet refurbished

    CERN Multimedia

    2009-01-01

    PS Magnet Refurbishment Programme Completed. The 51st and final refurbished magnet was transported to the PS on Tuesday 3 February. The repair and consolidation work on the PS started back in 2003 when two magnets and a busbar connection were found to be faulty during routine high-voltage tests. The cause of the fault was a combination of age and radiation on electrical insulation. After further investigation the decision was taken to overhaul half of the PS’s 100 magnets to reduce the risk of a similar fault. As from 20 February the PS ring will start a five-week test programme to be ready for operation at the end of March.

  16. World Magnetic Model 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  17. World Magnetic Model 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  18. Magnets for Pain Relief

    Science.gov (United States)

    ... NCCIH NCCIH At a Glance Mission and Vision Organizational Structure Director's Message Strategic Plans & Reports Budget & ... © Matthew Lester Magnets are often marketed for different types of pain, such as foot or back pain ...

  19. Self pumping magnetic cooling

    International Nuclear Information System (INIS)

    Chaudhary, V; Wang, Z; Ray, A; Ramanujan, R V; Sridhar, I

    2017-01-01

    Efficient thermal management and heat recovery devices are of high technological significance for innovative energy conservation solutions. We describe a study of a self-pumping magnetic cooling device, which does not require external energy input, employing Mn–Zn ferrite nanoparticles suspended in water. The device performance depends strongly on magnetic field strength, nanoparticle content in the fluid and heat load temperature. Cooling (Δ T ) by ∼20 °C and ∼28 °C was achieved by the application of 0.3 T magnetic field when the initial temperature of the heat load was 64 °C and 87 °C, respectively. These experiments results were in good agreement with simulations performed with COMSOL Multiphysics. Our system is a self-regulating device; as the heat load increases, the magnetization of the ferrofluid decreases; leading to an increase in the fluid velocity and consequently, faster heat transfer from the heat source to the heat sink. (letter)

  20. Magnetic separation of algae

    Science.gov (United States)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  1. Synthetic magnetic opals

    Indian Academy of Sciences (India)

    2JDS Uniphase Corporation, 625 Industrial Way, Eatontown, NJ 07724, USA ..... the Swedish funding agency VINNOVA for financing this project. VA, PS ... [5] B D Cullity, Introduction to magnetic materials (Addison-Wesley Publishing Co.) p.

  2. Magnetic Resonance (MR) Defecography

    Science.gov (United States)

    ... to a CD or uploaded to a digital cloud server. Magnetic resonance (MR) defecography is a special ... with you. top of page What are the benefits vs. risks? Benefits MR defecography helps assess pelvic ...

  3. LHC bending magnet coil

    CERN Multimedia

    A short test version of coil of wire used for the LHC dipole magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair.

  4. Photons and magnetization

    Czech Academy of Sciences Publication Activity Database

    Pile, P.; Němec, P.; Jungwirth, Tomáš

    2013-01-01

    Roč. 7, č. 6 (2013), s. 500 ISSN 1749-4885 Institutional support: RVO:68378271 Keywords : spintronics * photonics * magneto-optics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 29.958, year: 2013

  5. Magnetic resonance angiography (MRA)

    International Nuclear Information System (INIS)

    Arlart, I.P.; Guhl, L.

    1992-01-01

    An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

  6. Magnetic Resonance Cholangiopancreatography (MRCP)

    Science.gov (United States)

    ... radio waves and a computer to evaluate the liver, gallbladder, bile ducts, pancreas and pancreatic duct for disease. It is ... of the hepatobiliary and pancreatic systems, including the liver, gallbladder, bile ducts, pancreas and pancreatic duct . Magnetic resonance imaging (MRI) ...

  7. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  8. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb$_{3}$Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  9. Magnetic ''islandography'' in tokamaks

    International Nuclear Information System (INIS)

    Callen, J.D.; Waddell, B.V.; Hicks, H.R.

    1978-09-01

    Tearing modes are shown to be responsible for most of the experimentally observed macroscopic behavior of tokamak discharges. The effects of these collective magnetic perturbations on magnetic topology and plasma transport in tokamaks are shown to provide plausible explanations for: internal disruptions (m/n = 1); Mirnov oscillations (m/n = 2,3...); and major disruptions (coupling of 2/1-3/2 modes). The nonlinear evolution of the tearing modes is followed with fully three-dimensional computer codes. The effects on plasma confinement of the magnetic islands or stochastic field lines induced by the macroscopic tearing modes are discussed and compared with experiment. Finally, microscopic magnetic perturbations are shown to provide a natural model for the microscopic anomalous transport processes in tokamaks

  10. Ferumoxtran-10 advanced magnetics.

    NARCIS (Netherlands)

    Leenders, W.P.J.

    2003-01-01

    Ferumoxtran-10 (Combidex) is an ultra-small superparamagnetic iron oxide molecular resonance imaging contrast agent under development by Advanced Magnetics Ltd and Guerbet for the principal indication of lymph node imaging.

  11. Airborne Magnetic Trackline Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receive airborne magnetic survey data from US and non-US...

  12. 1000th magnet delivered!

    CERN Multimedia

    2006-01-01

    On Monday 20 February members of the AT Department marked the delivery of the 1000th superconducting dipole magnet to CERN. Only 232 more of the dipole magnets are needed for the LHC. The 35 tonne-dipoles are 15 meters long and are being manufactured by three companies: Babcock Noell Nuclear in Germany (which finished its contract in November 2005), Ansaldo Superconduttori in Italy and Alstom-Jeumont in France. "The production is proceeding well and we expect to be complete in October as previously foreseen," said Lucio Rossi, Head of the Magnets and Superconductors Group (AT-MAS). In total, 1650 main magnets are needed for the LHC, of which 1300 have been delivered.

  13. 1000th magnet delivered!

    CERN Multimedia

    2006-01-01

    On Monday 20 February members of the AT Department marked the delivery of the 1000th superconducting dipole magnet to CERN. Only 232 more of the dipole magnets are needed for the LHC. The 35-tonne-dipoles are 15 meters long and are being manufactured by three companies: Babcock Noell Nuclear in Germany (which completed its contract in November 2005), Ansaldo Superconduttori in Italy and Alstom-Jeumont in France. 'The production is proceeding well and we expect to be complete in October as foreseen,' said Lucio Rossi, Head of the Magnets and Superconductors Group (AT-MAS). In total, 1650 main magnets are needed for the LHC, of which 1300 have already been delivered.

  14. Expansion of magnetic clouds

    International Nuclear Information System (INIS)

    Suess, S.T.

    1987-01-01

    Magnetic clouds are a carefully defined subclass of all interplanetary signatures of coronal mass ejections whose geometry is thought to be that of a cylinder embedded in a plane. It has been found that the total magnetic pressure inside the clouds is higher than the ion pressure outside, and that the clouds are expanding at 1 AU at about half the local Alfven speed. The geometry of the clouds is such that even though the magnetic pressure inside is larger than the total pressure outside, expansion will not occur because the pressure is balanced by magnetic tension - the pinch effect. The evidence for expansion of clouds at 1 AU is nevertheless quite strong so another reason for its existence must be found. It is demonstrated that the observations can be reproduced by taking into account the effects of geometrical distortion of the low plasma beta clouds as they move away from the Sun

  15. ISR Radial Field Magnet

    CERN Multimedia

    1983-01-01

    There were 37 (normal) + 3 (special) Radial Field magnets in the ISR to adjust vertically the closed orbit. Gap heights and strengths were 200 mm and .12 Tm in the normal magnets, 220 mm and .18 Tm in the special ones. The core length was 430 mm in both types. Due to their small length as compared to the gap heights the end fringe field errors were very important and had to be compensated by suitably shaping the poles. In order to save on cables, as these magnets were located very far from their power supplies, the coils of the normal type magnets were formed by many turns of solid cpper conductor with some interleaved layers of hollow conductor directly cooled by circulating water

  16. Magnetic vortex racetrack memory

    Science.gov (United States)

    Geng, Liwei D.; Jin, Yongmei M.

    2017-02-01

    We report a new type of racetrack memory based on current-controlled movement of magnetic vortices in magnetic nanowires with rectangular cross-section and weak perpendicular anisotropy. Data are stored through the core polarity of vortices and each vortex carries a data bit. Besides high density, non-volatility, fast data access, and low power as offered by domain wall racetrack memory, magnetic vortex racetrack memory has additional advantages of no need for constrictions to define data bits, changeable information density, adjustable current magnitude for data propagation, and versatile means of ultrafast vortex core switching. By using micromagnetic simulations, current-controlled motion of magnetic vortices in cobalt nanowire is demonstrated for racetrack memory applications.

  17. Magnetic Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Robert H. Morris

    2014-11-01

    Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

  18. Large Superconducting Magnet Systems

    Energy Technology Data Exchange (ETDEWEB)

    Védrine, P [Saclay (France)

    2014-07-01

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  19. Novel Magnetic Devices

    National Research Council Canada - National Science Library

    Schuller, Ivan

    2007-01-01

    ...: ballistic magnetoresistance, magnetic field proximity effect and spin drag. These three phenomena would then be exploited for the design of novel device architectures and to investigate the physical principles behind these devices...

  20. Magnetic electron scattering

    International Nuclear Information System (INIS)

    Peterson, G.A.

    1989-01-01

    We briefly review some of the motivations, early results, and techniques of magnetic elastic and inelastic electron-nucleus scattering. We then discuss recent results, especially those acquired at high momentum transfers. 50 refs., 19 figs

  1. Magnetic fields in cosmology

    International Nuclear Information System (INIS)

    Madsen, M.S.

    1989-01-01

    The possible role of a large-scale relic magnetic field in the history of the Universe is considered. The perturbation of the cosmic microwave back-ground radiation on large angular scales due to a homogeneous magnetic field is estimated in a simple relativistic model. This allows corresponding limits to be placed on the magnitude of any such large-scale relic magnetic field at the present time. These limits are essentially the strongest which can be set on the largest scales. A corresponding bound is obtained by use of the requirement that the field should not spoil the predictions of primordial nucleosynthesis. It is noted that the existence of large-scale cosmic magnetic fields would circumvent the limits previously set - also on the basis of nucleosynthesis considerations - on the large-scale anisotropy now present in the Universe. (author)

  2. Magnetic interactions between nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Mikkel Fougt; Frandsen, Cathrine

    2010-01-01

    We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state...... of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples...... of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions....

  3. Magnetic resonance angiography

    Science.gov (United States)

    ... Saunders; 2015:chap 17. Litt H, Carpenter JP. Magnetic resonance imaging. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

  4. Magnetic reconnection during eruptive magnetic flux ropes

    Science.gov (United States)

    Mei, Z. X.; Keppens, R.; Roussev, I. I.; Lin, J.

    2017-08-01

    Aims: We perform a three-dimensional (3D) high resolution numerical simulation in isothermal magnetohydrodynamics to study the magnetic reconnection process in a current sheet (CS) formed during an eruption of a twisted magnetic flux rope (MFR). Because the twist distribution violates the Kruskal-Shafranov condition, the kink instability occurs, and the MFR is distorted. The centre part of the MFR loses its equilibrium and erupts upward, which leads to the formation of a 3D CS underneath it. Methods: In order to study the magnetic reconnection inside the CS in detail, mesh refinement has been used to reduce the numerical diffusion and we estimate a Lundquist number S = 104 in the vicinity of the CS. Results: The refined mesh allows us to resolve fine structures inside the 3D CS: a bifurcating sheet structure signaling the 3D generalization of Petschek slow shocks, some distorted-cylindrical substructures due to the tearing mode instabilities, and two turbulence regions near the upper and the lower tips of the CS. The topological characteristics of the MFR depend sensitively on the observer's viewing angle: it presents as a sigmoid structure, an outwardly expanding MFR with helical distortion, or a flare-CS-coronal mass ejection symbiosis as in 2D flux-rope models when observed from the top, the front, or the side. The movie associated to Fig. 2 is available at http://www.aanda.org

  5. The 2017 magnetism roadmap

    Czech Academy of Sciences Publication Activity Database

    Sander, D.; Valenzuela, S.O.; Makarov, D.; Marrows, C.H.; Fullerton, E.E.; Fischer, P.; McCord, J.; Vavassori, P.; Mangin, S.; Pirro, P.; Hillebrands, B.; Kent, A.D.; Jungwirth, Tomáš; Gutfleisch, O.; Kim, C.G.; Berger, A.

    2017-01-01

    Roč. 50, č. 36 (2017), s. 1-33, č. článku 363001. ISSN 0022-3727 R&D Projects: GA MŠk LM2015087; GA ČR GB14-37427G Institutional support: RVO:68378271 Keywords : magnetism * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.588, year: 2016

  6. Magnetic coupling device

    Science.gov (United States)

    Nance, Thomas A [Aiken, SC

    2009-08-18

    A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.

  7. Magnetic-fusion program

    International Nuclear Information System (INIS)

    1980-08-01

    In February 1980, the Director of Energy Research requested that the Energy Research Advisory Board (ERAB) review the Department of Energy (DOE) Magnetic Fusion Program. Of particular concern to the DOE was the judicious choice of the next major steps toward demonstration of economic power production from fusion. Of equal concern was the overall soundness of the DOE Magnetic Fusion Program: its pace, scope, and funding profiles. Their finding and recommendations are included

  8. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Robertson, Angus

    1990-01-01

    An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs

  9. A superconducting magnetic gear

    International Nuclear Information System (INIS)

    Campbell, A M

    2016-01-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844–46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further. (paper)

  10. LHC Magnet test failure

    CERN Multimedia

    2007-01-01

    "On Tueday, March 22, a Fermilab-built quadrupole magnet, one of an "inner triplet" of three focusing magnets, failed a high-pressure test at Point 5 in the tunnel of the LHC accelerator at CERN. Since Tuesday, teams at CERN and Fermilab have worked closely together to address the problem and have identified the cause of the failure. Now they are at work on a solution.:" (1 page)

  11. Nuclear magnetic resonance gyroscope

    International Nuclear Information System (INIS)

    Grover, B.C.

    1984-01-01

    A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor

  12. Biofunctionalized Magnetic Nanowires

    KAUST Repository

    Kosel, Jurgen

    2013-12-19

    Magnetic nanowires can be used as an alternative method overcoming the limitations of current cancer treatments that lack specificity and are highly cytotoxic. Nanowires are developed so that they selectively attach to cancer cells via antibodies, potentially destroying them when a magnetic field induces their vibration. This will transmit a mechanical force to the targeted cells, which is expected to induce apoptosis on the cancer cells.

  13. EUCARD magnet development

    OpenAIRE

    de Rijk, Gijs

    2011-01-01

    The FP7-EuCARD work package 7 (WP7), "HFM: Superconducting High Field Magnets for higher luminosities and energies" is a collaboration between 12 European institutes and firms with the objective of developing high field magnet technology. WP7 foresees to construct a 13 T dipole with a 100 mm aperture, a B = 6 T high temperature superconductor (HTS) dipole insert, a superconducting HTS link and a superconducting helical undulator.

  14. Magnetic field dosimeter development

    International Nuclear Information System (INIS)

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation

  15. Nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    In a method of imaging a body in which nuclear magnetic resonance is excited in a region including part of the body, and the free induction decay signal is measured, a known quantity of a material of known nuclear magnetic resonance properties, for example a bag of water, is included in the region so as to enhance the measured free induction decay signal. This then reduces the generation of noise during subsequent processing of the signal. (author)

  16. AA, bending magnet, BLG

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The very particular lattice of the AA required 2 types of dipole (bending magnets; BLG, long and narrow; BST, short and wide). The BLG had a steel length of 4.70 m, a good field width of 0.24 m, and a weight of about 70 t. Jean-Claude Brunet inspects the lower half of a BLG. For the BST magnets see 7811105 and 8006036.

  17. Biomimetic magnetic nanoparticles

    OpenAIRE

    Klem, Michael T.; Young, Mark; Douglas, Trevor

    2005-01-01

    Magnetic nanoparticles are of considerable interest because of their potential use in high-density memory devices, spintronics, and applications in diagnostic medicine. The conditions for synthesis of these materials are often complicated by their high reaction temperatures, costly reagents, and post-processing requirements. Practical applications of magnetic nanoparticles will require the development of alternate synthetic strategies that can overcome these impediments. Biomimetic approaches...

  18. Superconducting magnets for accelerators

    International Nuclear Information System (INIS)

    Denisov, Yu.N.

    1979-01-01

    Expediency of usage and possibilities arising in application of superconducting devices in magnetic systems of accelerators and experimental nuclear-physical devices are studied. Parameters of specific devices are given. It is emphasized that at the existing level of technological possibilities, construction and usage of superconducting magnetic systems in experimental nuclear physics should be thought of as possible, from the engineering, and expedient, from the economical viewpoints [ru

  19. Biofunctionalized Magnetic Nanowires

    KAUST Repository

    Kosel, Jü rgen; Ravasi, Timothy; Contreras Gerenas, Maria Fernanda

    2013-01-01

    Magnetic nanowires can be used as an alternative method overcoming the limitations of current cancer treatments that lack specificity and are highly cytotoxic. Nanowires are developed so that they selectively attach to cancer cells via antibodies, potentially destroying them when a magnetic field induces their vibration. This will transmit a mechanical force to the targeted cells, which is expected to induce apoptosis on the cancer cells.

  20. Magnetic biosensor system to detect biological targets

    KAUST Repository

    Li, Fuquan; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    magnetic concentration, magnetic as well as mechanical trapping and magnetic sensing. Target detection is based on the size difference between bare magnetic beads and magnetic beads with targets attached. This method remedies the need for a coating layer

  1. Wiggler magnets at SSRL

    International Nuclear Information System (INIS)

    Winick, H.

    1980-01-01

    A wiggler magnet has been installed in SPEAR and has been routinely used as a radiation source for Beam Line IV at SSRL since March, 1979. The magnets is 1.22 m long. It has five full central poles and two end half-poles producing a total of three complete small amplitude (<= 1 mm) oscillations of the electron beam in traversing the magnet. The magnet has been operated with the peak field in the central full poles at 17.2 kG and produces an intense beam of synchrotron radiation extending to 12 keV and beyond even at the lowest operating energies of SPEAR (1.5 GeV). It is compatible with all phases of colliding-beam operation of SPEAR and has improved the colliding-beam luminosity. The results of measurements on the spectrum and intensity of the radiation produced by the Wiggler will be presented. The measured effects of the wiggler on the stored beam tunes, energy spread and emittance will also be presented. Plans will also be described for installing additional high field wiggler magnets in SPEAR and also weak-field, many-period undulator magnets in both SPEAR and PEP. (orig.)

  2. Superconducting Magnets for Accelerators

    Science.gov (United States)

    Brianti, G.; Tortschanoff, T.

    1993-03-01

    This chapter describes the main features of superconducting magnets for high energy synchrotrons and colliders. It refers to magnets presently used and under development for the most advanced accelerators projects, both recently constructed or in the preparatory phase. These magnets, using the technology mainly based on the NbTi conductor, are described from the aspect of design, materials, construction and performance. The trend toward higher performance can be gauged from the doubling of design field in less than a decade from about 4 T for the Tevatron to 10 T for the LHC. Special properties of the superconducting accelerator magnets, such as their general layout and the need of extensive computational treatment, the limits of performance inherent to the available conductors, the requirements on the structural design are described. The contribution is completed by elaborating on persistent current effects, quench protection and the cryostat design. As examples the main magnets for HERA and SSC, as well as the twin-aperture magnets for LHC, are presented.

  3. Nanolubricant: magnetic nanoparticle based

    Science.gov (United States)

    Trivedi, Kinjal; Parekh, Kinnari; Upadhyay, Ramesh V.

    2017-11-01

    In the present study magnetic nanoparticles of Fe3O4 having average particle diameter, 11.7 nm were synthesized using chemical coprecipitation technique and dispersed in alpha olefin hydrocarbon synthetic lubricating oil. The solid weight fraction of magnetic nanoparticles in the lubricating oil was varied from 0 wt% to 10 wt%. The tribological properties were studied using four-ball tester. The results demonstrate that the coefficient of friction and wear scar diameter reduces by 45% and 30%, respectively at an optimal value, i.e. 4 wt% of magnetic nanoparticles concentration. The surface characterization of worn surface was carried out using a scanning electron microscope, and energy dispersive spectroscopy. These results implied that rolling mechanism is responsible to reduce coefficient of friction while magnetic nanoparticles act as the spacer between the asperities and reduces the wear scar diameter. The surface roughness of the worn surface studied using an atomic force microscope shows a reduction in surface roughness by a factor of four when magnetic nanoparticles are used as an additive. The positive response of magnetic nanoparticles in a lubricating oil, shows the potential replacement of conventional lubricating oil.

  4. Magnetic Fields Versus Gravity

    Science.gov (United States)

    Hensley, Kerry

    2018-04-01

    Deep within giant molecular clouds, hidden by dense gas and dust, stars form. Unprecedented data from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal the intricate magnetic structureswoven throughout one of the most massive star-forming regions in the Milky Way.How Stars Are BornThe Horsehead Nebulasdense column of gas and dust is opaque to visible light, but this infrared image reveals the young stars hidden in the dust. [NASA/ESA/Hubble Heritage Team]Simple theory dictates that when a dense clump of molecular gas becomes massive enough that its self-gravity overwhelms the thermal pressure of the cloud, the gas collapses and forms a star. In reality, however, star formation is more complicated than a simple give and take between gravity and pressure. Thedusty molecular gas in stellar nurseries is permeated with magnetic fields, which are thought to impede the inward pull of gravity and slow the rate of star formation.How can we learn about the magnetic fields of distant objects? One way is by measuring dust polarization. An elongated dust grain will tend to align itself with its short axis parallel to the direction of the magnetic field. This systematic alignment of the dust grains along the magnetic field lines polarizes the dust grains emission perpendicular to the local magnetic field. This allows us to infer the direction of the magnetic field from the direction of polarization.Magnetic field orientations for protostars e2 and e8 derived from Submillimeter Array observations (panels a through c) and ALMA observations (panels d and e). Click to enlarge. [Adapted from Koch et al. 2018]Tracing Magnetic FieldsPatrick Koch (Academia Sinica, Taiwan) and collaborators used high-sensitivity ALMA observations of dust polarization to learn more about the magnetic field morphology of Milky Way star-forming region W51. W51 is one of the largest star-forming regions in our galaxy, home to high-mass protostars e2, e8, and North.The ALMA observations reveal

  5. Magnetic metallic multilayers

    International Nuclear Information System (INIS)

    Hood, R.Q.

    1994-04-01

    Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons

  6. Magnet cooling economics

    International Nuclear Information System (INIS)

    Parmer, J.F.; Liggett, M.W.

    1985-01-01

    The recommendation to use superfluid helium II in superconducting magnet design has become more prevalent in recent years. Advanced fusion reactor studies such as the Mirror Advanced Reactor Study recently completed by the Lawrence Livermore National Laboratory (LLML) have based superconducting magnet design on the use of He II because of reduced magnet volume, improved stability characteristics, or increased superconductor critical current at fields above 9 Tesla. This paper reports the results of a study to determine the capital costs ($/watt) and the operating costs (watts/watt) of refrigeration systems in the 1.8K to 300K temperature range. The cost data is applied to a 1.8K magnet that is subject to neutronic heating wherein the magnet case is insulated from the winding so that the case can be cooled at a higher temperature (less costly) than the winding. The life cycle cost (capital plus operating) is reported as a function of coil temperature and insulation thickness. In some cases there is an optimum, least-cost thickness. In addition, the basic data can be used to evaluate the impact of neutron shielding effectiveness trades on the combined shield, magnet, cryorefrigerator, and operating life cycle cost

  7. High magnetic field MRI system

    International Nuclear Information System (INIS)

    Maeda, Hideaki; Urata, Masami; Satoh, Kozo

    1990-01-01

    A high field superconducting magnet, 4-5 T in central magnetic field, is required for magnetic resonance spectroscopic imaging (MRSI) on 31 P, essential nuclei for energy metabolism of human body. This paper reviews superconducting magnets for high field MRSI systems. Examples of the cross-sectional image and the spectrum of living animals are shown in the paper. (author)

  8. Quenches in large superconducting magnets

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Alston-Garnjost, M.; Green, M.A.; Lecomte, P.; Smits, R.G.; Taylor, J.D.; Vuillemin, V.

    1977-08-01

    The development of large high current density superconducting magnets requires an understanding of the quench process by which the magnet goes normal. A theory which describes the quench process in large superconducting magnets is presented and compared with experimental measurements. The use of a quench theory to improve the design of large high current density superconducting magnets is discussed

  9. MAGNETIC NEUTRON SCATTERING

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-30

    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

  10. Magnetic flux concentration methods for magnetic energy harvesting module

    Directory of Open Access Journals (Sweden)

    Wakiwaka Hiroyuki

    2013-01-01

    Full Text Available This paper presents magnetic flux concentration methods for magnetic energy harvesting module. The purpose of this study is to harvest 1 mW energy with a Brooks coil 2 cm in diameter from environmental magnetic field at 60 Hz. Because the harvesting power is proportional to the square of the magnetic flux density, we consider the use of a magnetic flux concentration coil and a magnetic core. The magnetic flux concentration coil consists of an air­core Brooks coil and a resonant capacitor. When a uniform magnetic field crossed the coil, the magnetic flux distribution around the coil was changed. It is found that the magnetic field in an area is concentrated larger than 20 times compared with the uniform magnetic field. Compared with the air­core coil, our designed magnetic core makes the harvested energy ten­fold. According to ICNIRP2010 guideline, the acceptable level of magnetic field is 0.2 mT in the frequency range between 25 Hz and 400 Hz. Without the two magnetic flux concentration methods, the corresponding energy is limited to 1 µW. In contrast, our experimental results successfully demonstrate energy harvesting of 1 mW from a magnetic field of 0.03 mT at 60 Hz.

  11. Freely oriented portable superconducting magnet

    Science.gov (United States)

    Schmierer, Eric N [Los Alamos, NM; Prenger, F Coyne [Los Alamos, NM; Hill, Dallas D [Los Alamos, NM

    2010-01-12

    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.

  12. Magnetically responsive calcium carbonate microcrystals.

    Science.gov (United States)

    Fakhrullin, Rawil F; Bikmullin, Aidar G; Nurgaliev, Danis K

    2009-09-01

    Here we report the fabrication of magnetically responsive calcium carbonate microcrystals produced by coprecipitation of calcium carbonate in the presence of citrate-stabilized iron oxide nanoparticles. We demonstrate that the calcite microcrystals obtained possess superparamagnetic properties due to incorporated magnetite nanoparticles and can be manipulated by an external magnetic field. The microcrystals doped with magnetic nanoparticles were utilized as templates for the fabrication of hollow polyelectrolyte microcapsules, which retain the magnetic properties of the sacrificial cores and might be spatially manipulated using a permanent magnet, thus providing the magnetic-field-facilitated delivery and separation of materials templated on magnetically responsive calcite microcrystals.

  13. Synthesis of magnetic polymeric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2010-05-13

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  14. Synthesis of magnetic polymeric microspheres

    International Nuclear Information System (INIS)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I

    2010-01-01

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  15. Handbook of Advanced Magnetic Materials

    CERN Document Server

    Liu, Yi; Shindo, Daisuke

    2006-01-01

    From high-capacity, inexpensive hard drives to mag-lev trains, recent achievements in magnetic materials research have made the dreams of a few decades ago reality. The objective of Handbook of Advanced Magnetic Materials is to provide a timely, comprehensive review of recent progress in magnetic materials research. This broad yet detailed reference consists of four volumes: 1.) Nanostructured advanced magnetic materials, 2.) Characterization and simulation of advanced magnetic materials, 3.) Processing of advanced magnetic materials, and 4.) Properties and applications of advanced magnetic materials The first volume documents and explains recent development of nanostructured magnetic materials, emphasizing size effects. The second volume provides a comprehensive review of both experimental methods and simulation techniques for the characterization of magnetic materials. The third volume comprehensively reviews recent developments in the processing and manufacturing of advanced magnetic materials. With the co...

  16. Streaming flows produced by oscillating interface of magnetic fluid adsorbed on a permanent magnet in alternating magnetic field

    Science.gov (United States)

    Sudo, S.; Ito, M.; Ishimoto, Y.; Nix, S.

    2017-04-01

    This paper describes microstreaming flows generated by oscillating interface of magnetic fluid adsorbed on a circular cylindrical permanent magnet in alternating magnetic field. The interface of magnetic fluid adsorbed on the NdFeB magnet responds to the external alternating magnetic flied as harmonic oscillation. The directions of alternating magnetic field are parallel and antiparallel to the magnetic field of permanent magnet. The oscillation of magnetic fluid interface generates streaming flow around the magnet-magnetic fluid element in water. Microstreaming flows are observed with a high-speed video camera analysis system. The flow pattern generated by magnetic fluid motion depends on the Keulegan-Carpenter number and the Reynolds number.

  17. Magnetic Nanocomposite Cilia Sensors

    KAUST Repository

    Alfadhel, Ahmed

    2016-07-19

    Recent progress in the development of artificial skin concepts is a result of the increased demand for providing environment perception such as touch and flow sensing to robots, prosthetics and surgical tools. Tactile sensors are the essential components of artificial skins and attracted considerable attention that led to the development of different technologies for mimicking the complex sense of touch in humans. This dissertation work is devoted to the development of a bioinspired tactile sensing technology that imitates the extremely sensitive hair-like cilia receptors found in nature. The artificial cilia are fabricated from permanent magnetic, biocompatible and highly elastic nanocomposite material, and integrated on a giant magneto-impedance magnetic sensor to measure the stray field. A force that bends the cilia changes the stray field and is therefore detected with the magnetic sensor, providing high performance in terms of sensitivity, power consumption and versatility. The nanocomposite is made of Fe nanowires (NWs) incorporated into polydimethylsiloxane (PDMS). Fe NWs have a high remanent magnetization, due the shape anisotropy; thus, they are acting as permanent nano-magnets. This allows remote device operation and avoids the need for a magnetic field to magnetize the NWs, benefiting miniaturization and the possible range of applications. The magnetic properties of the nanocomposite can be easily tuned by modifying the NWs concentration or by aligning the NWs to define a magnetic anisotropy. Tactile sensors are realized on flexible and rigid substrates that can detect flow, vertical and shear forces statically and dynamically, with a high resolution and wide operating range. The advantage to operate the sensors in liquids and air has been utilized to measure flows in different fluids in a microfluidic channel. Various dynamic studies were conducted with the tactile sensor demonstrating the detection of moving objects or the texture of objects. Overall

  18. Negative magnetic relaxation in superconductors

    Directory of Open Access Journals (Sweden)

    Krasnoperov E.P.

    2013-01-01

    Full Text Available It was observed that the trapped magnetic moment of HTS tablets or annuli increases in time (negative relaxation if they are not completely magnetized by a pulsed magnetic field. It is shown, in the framework of the Bean critical-state model, that the radial temperature gradient appearing in tablets or annuli during a pulsed field magnetization can explain the negative magnetic relaxation in the superconductor.

  19. Magnetic circuit with large blocks from NdFeB magnets for suspended magnetic separators

    Czech Academy of Sciences Publication Activity Database

    Žežulka, Václav

    2010-01-01

    Roč. 7, č. 2 (2010), s. 227-235 ISSN 1214-9705 Institutional research plan: CEZ:AV0Z30460519 Keywords : magnetic circuits * magnetic separation * permanent magnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.452, year: 2010 www.irsm.cas.cz/?Lang=CZE&Menu=25,0,0,0

  20. Magnetism and magnetic materials probed with neutron scattering

    International Nuclear Information System (INIS)

    Velthuis, S.G.E. te; Pappas, C.

    2014-01-01

    Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale. - Highlights: • Introduction to Current Perspective series titled Magnetism and Magnetic Materials probed with Neutron Scattering. • Elastic and inelastic neutron scattering in systems with magnetic frustration and superconductivity. • Small angle neutron scattering and polarized neutron reflectometry in studying magnetism at the nanoscale. • Imaging of magnetic fields and domains

  1. Superconducting permanent magnets and their application in magnetic levitation

    International Nuclear Information System (INIS)

    Schultz, L.; Krabbes, G.; Fuchs, G.; Pfeiffer, W.; Mueller, K.H.

    2002-01-01

    Superconducting permanent magnets form a completely new class of permanent magnets. Of course, they must be cooled to 77 K or below. At very low temperatures (24 K) their magnetization can be a factor of 10 higher than that of the best conventional magnets, providing magnetic forces and energies which are up to two orders of magnitude higher. These new supermagnets became only recently available by the extreme improvement of the quality of melt-textured massive YBa 2 Cu 3 O x samples. Besides having a high magnetization, these superconducting permanent magnets can freeze in any given magnetic field configuration allowing completely new applications like superconducting transport systems or superconducting magnetic bearings. (orig.)

  2. Magnetism and magnetic materials probed with neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Velthuis, S.G.E. te, E-mail: tevelthuis@anl.gov [Materials Science Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, IL 60439 (United States); Pappas, C. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, NL-2629JB Delft (Netherlands)

    2014-01-15

    Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale. - Highlights: • Introduction to Current Perspective series titled Magnetism and Magnetic Materials probed with Neutron Scattering. • Elastic and inelastic neutron scattering in systems with magnetic frustration and superconductivity. • Small angle neutron scattering and polarized neutron reflectometry in studying magnetism at the nanoscale. • Imaging of magnetic fields and domains.

  3. On the absorbing force of magnetic fields acting on magnetic particle under magnetic particle examination

    International Nuclear Information System (INIS)

    Maeda, N.

    1988-01-01

    During the magnetic particle examination, magnetic particles near defects are deposited by an absorbing force of magnetic fields acting on the magnetic particles. Therefore, a quantitative determination of this absorbing force is a theoretical and experimental basis for solving various problems associated with magnetic particle examinations. The absorbing force is formulated based on a magnetic dipole model, and a measuring method of the absorbing force using magnetic fields formed around linear current is proposed. Measurements according to this method produced appropriate results, verifying the validation of the concept and the measuring method

  4. Magnetic Thermometer: Thermal effect on the Agglomeration of Magnetic Nanoparticles by Magnetic field

    Science.gov (United States)

    Jin, Daeseong; Kim, Hackjin

    2018-03-01

    We have investigated the agglomeration of magnetite nanoparticles in the aqueous solution under magnetic field by measuring temporal change of magnetic weight. The magnetic weight corresponds to the force due to the magnetization of magnetic materials. Superparamagnetic magnetite nanoparticles are synthesized and used in this work. When the aqueous solution of magnetite nanoparticle is placed under magnetic field, the magnetic weight of the sample jumps instantaneously by Neel and Brown mechanisms and thereafter increases steadily following a stretched exponential function as the nanoparticles agglomerate, which results from the distribution of energy barriers involved in the dynamics. Thermal motions of nanoparticles in the agglomerate perturb the ordered structure of the agglomerate to reduce the magnetic weight. Fluctuation of the structural order of the agglomerate by temperature change is much faster than the formation of agglomerate and explained well with the Boltzmann distribution, which suggests that the magnetic weight of the agglomerate works as a magnetic thermometer.

  5. LHC magnet support post

    CERN Multimedia

    1995-01-01

    A prototype magnet support for the Large Hadron Collider (LHC). The magnet supports have to bridge a difference in temperature of 300 degrees. Electrical connections, instrumentation and the posts on which the magnets stand are the only points where heat transfer can happen through conduction. They are all carefully designed to draw off heat progressively. The posts are made of 4 mm thick glass-fibre– epoxy composite material. Each post supports 10 000 kg of magnet and leaks just 0.1 W of heat. This piece required a long development period which started in the early ’90s and continued until the end of the decade. The wires next to the support post are wires from strain gauges, which are employed to measure the stress level in the material when the support is mechanically loaded. These supports are mechanically optimized to withstand a weight of up to 100Kn (10 tons) while being as thin as possible to minimize conduction heat to magnets. This is the reason why the stress measurement was extensively done...

  6. Magnetic safety matches

    Science.gov (United States)

    Lindén, J.; Lindberg, M.; Greggas, A.; Jylhävuori, N.; Norrgrann, H.; Lill, J. O.

    2017-07-01

    In addition to the main ingredients; sulfur, potassium chlorate and carbon, ordinary safety matches contain various dyes, glues etc, giving the head of the match an even texture and appealing color. Among the common reddish-brown matches there are several types, which after ignition can be attracted by a strong magnet. Before ignition the match head is generally not attracted by the magnet. An elemental analysis based on proton-induced x-ray emission was performed to single out iron as the element responsible for the observed magnetism. 57Fe Mössbauer spectroscopy was used for identifying the various types of iron-compounds, present before and after ignition, responsible for the macroscopic magnetism: Fe2O3 before and Fe3O4 after. The reaction was verified by mixing the main chemicals in the match-head with Fe2O3 in glue and mounting the mixture on a match stick. The ash residue after igniting the mixture was magnetic.

  7. Magnetic Fluxtube Tunneling

    Science.gov (United States)

    Dahlburg, Russell B.; Antiochos,, Spiro K.; Norton, D.

    1996-01-01

    We present numerical simulations of the collision and subsequent interaction of two initially orthogonal, twisted, force free field magnetic fluxtubes. The simulations were carried out using a new three dimensional explicit parallelized Fourier collocation algorithm for solving the viscoresistive equations of compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the fluxtubes can 'tunnel' through each other. Two key conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch much greater than 1, and the magnetic Lundquist number must be somewhat large, greater than or equal to 2880. This tunneling behavior has not been seen previously in studies of either vortex tube or magnetic fluxtube interactions. An examination of magnetic field lines shows that tunneling is due to a double reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections and 'pass' through each other. The implications of these results for solar and space plasmas are discussed.

  8. Magnetic binary nanofillers

    International Nuclear Information System (INIS)

    Morales Mendoza, N.; Goyanes, S.; Chiliotte, C.; Bekeris, V.; Rubiolo, G.; Candal, R.

    2012-01-01

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 °C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 μm) and sample B (smaller than 50 μm). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of α-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing α-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 μm showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 μm. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  9. Magnetic binary nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Morales Mendoza, N. [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Goyanes, S. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Chiliotte, C.; Bekeris, V. [LBT, Dep. De Fisica, FCEN-UBA. Ciudad Universitaria, Pab1, C1428EGA CABA (Argentina); Rubiolo, G. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Unidad de Actividad Materiales, CNEA, Av Gral. Paz 1499, San Martin (1650), Prov. de Bs As (Argentina); Candal, R., E-mail: candal@qi.fcen.uba.ar [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); Escuela de Ciencia y Tecnologia, 3iA, Universidad de Gral. San Martin, San Martin, Prov. Bs As (Argentina)

    2012-08-15

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 Degree-Sign C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 {mu}m) and sample B (smaller than 50 {mu}m). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of {alpha}-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing {alpha}-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 {mu}m showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 {mu}m. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  10. Overdentures with magnetic attachments.

    Science.gov (United States)

    Gillings, B R; Samant, A

    1990-10-01

    Magnets were used only occasionally for dental purposes several decades ago. Since the advent of rare earth magnet alloys, however, intraoral magnets are shaping the course of aesthetics and retention for both complete and removable partial overdentures. Their benefits include simplicity, low cost, self-adjustment, inherent stress breaking, automatic reseating after denture displacement, comparative freedom of lateral denture movement, a low potential for trauma to the retained roots, and elimination of the need for adjustment in service. The clinical procedures involved in their application do not require any special skills, and the options offered by the various manufacturers give the dentist a wide variety of choices in selecting an appropriate treatment plan. Clinical experience has shown that magnetic retention offers an economical alternative for teeth that would otherwise require expensive or extensive restorative treatment, and can be used as an effective and often superior replacement for failed bridgework. Finally, it is clear that overdenture treatment per se is a valuable option for the dentist, and the use of magnets expands this option to the retention of tooth roots that might otherwise be scheduled for extraction. The natural tooth root, even if periodontally involved, can serve as a useful aid in denture support and retention, and should be regarded as at least as good as, and in most cases superior to, an implant. It is also much less expensive.

  11. Magnetically Coupled Calorimeters

    Science.gov (United States)

    Bandler, Simon

    2011-01-01

    Calorimeters that utilize the temperature sensitivity of magnetism have been under development for over 20 years. They have targeted a variety of different applications that require very high resolution spectroscopy. I will describe the properties of this sensor technology that distinguish it from other low temperature detectors and emphasize the types of application to which they appear best suited. I will review what has been learned so far about the best materials, geometries, and read-out amplifiers and our understanding of the measured performance and theoretical limits. I will introduce some of the applications where magnetic calorimeters are being used and also where they are in development for future experiments. So far, most magnetic calorimeter research has concentrated on the use of paramagnets to provide temperature sensitivity; recent studies have also focused on magnetically coupled calorimeters that utilize the diamagnetic response of superconductors. I will present some of the highlights of this research, and contrast the properties of the two magnetically coupled calorimeter types.

  12. R&D ERL: Magnetic measurements of the ERL magnets

    Energy Technology Data Exchange (ETDEWEB)

    Jain, A.

    2010-08-01

    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.

  13. Modified small angle magnetization rotation method in multilayer magnetic microwires

    International Nuclear Information System (INIS)

    Torrejon, J.; Badini, G.; Pirota, K.; Vazquez, M.

    2007-01-01

    The small angle magnetization rotation (SAMR) technique is a widely used method to quantify magnetostriction in elongated ultrasoft magnetic materials. In the present work, we introduce significant optimization of the method, particularly simplification of the required equipment, profiting of the very peculiar characteristics of a recently introduced family of multilayer magnetic microwires consisting of a soft magnetic core, insulating intermediate layer and a hard magnetic outer layer. The introduced modified SAMR method is used not only to determine the saturation magnetostriction constant of the soft magnetic nucleus but also the magnetoelastic and magnetostatic coupling. This new method has a great potential in multifunctional sensor applications

  14. Differential magnetic force microscope imaging.

    Science.gov (United States)

    Wang, Ying; Wang, Zuobin; Liu, Jinyun; Hou, Liwei

    2015-01-01

    This paper presents a method for differential magnetic force microscope imaging based on a two-pass scanning procedure to extract differential magnetic forces and eliminate or significantly reduce background forces with reversed tip magnetization. In the work, the difference of two scanned images with reversed tip magnetization was used to express the local magnetic forces. The magnetic sample was first scanned with a low lift distance between the MFM tip and the sample surface, and the magnetization direction of the probe was then changed after the first scan to perform the second scan. The differential magnetic force image was obtained through the subtraction of the two images from the two scans. The theoretical and experimental results have shown that the proposed method for differential magnetic force microscope imaging is able to reduce the effect of background or environment interference forces, and offers an improved image contrast and signal to noise ratio (SNR). © Wiley Periodicals, Inc.

  15. Magnetic x-ray microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Paul G [Computer-Aided Engineering Center, University of Wisconsin, Madison, WI 53706 (United States); Isaacs, Eric D [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2006-08-07

    Magnetic x-ray microdiffraction uses the structural specificity of x-ray diffraction to probe complex magnetic structures at the length scales relevant to physical phenomena including domain dynamics and phase transitions. Conventional magnetic crystallography techniques such as neutron or x-ray diffraction lack this spatial resolution. The combination of both reciprocal space and real space resolution with a rich magnetic cross section allows new microscopy techniques to be developed and applied to magnetism at the scale of single domains. Potential applications include a wide range of magnetic problems in nanomagnetism, the interaction of strain, polarization and magnetization in complex oxides and spatially resolved studies of magnetic phase transitions. We present the physical basis for x-ray microdiffraction and magnetic scattering processes, review microdiffraction domain imaging techniques in antiferromagnetic and ferromagnetic materials and discuss potential directions for studies. (topical review)

  16. Cosmic magnetic fields

    CERN Document Server

    Kronberg, Philipp P

    2016-01-01

    Magnetic fields are important in the Universe and their effects contain the key to many astrophysical phenomena that are otherwise impossible to understand. This book presents an up-to-date overview of this fast-growing topic and its interconnections to plasma processes, astroparticle physics, high energy astrophysics, and cosmic evolution. The phenomenology and impact of magnetic fields are described in diverse astrophysical contexts within the Universe, from galaxies to the filaments and voids of the intergalactic medium, and out to the largest redshifts. The presentation of mathematical formulae is accessible and is designed to add insight into the broad range of topics discussed. Written for graduate students and researchers in astrophysics and related disciplines, this volume will inspire readers to devise new ways of thinking about magnetic fields in space on galaxy scales and beyond.

  17. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  18. Magnetic Focusing Horn

    CERN Multimedia

    1974-01-01

    This magnetic focusing horn was used for the AA (antiproton accumulator). Its development was an important step towards using CERN's Super Proton Synchrotron as a proton - antiproton collider. This eventually led to the discovery of the W and Z particles in 1983. Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 -, three hundred thousand million - antiprotons.

  19. Diffraction. Single crystal, magnetic

    International Nuclear Information System (INIS)

    Heger, G.

    1999-01-01

    The analysis of crystal structure and magnetic ordering is usually based on diffraction phenomena caused by the interaction of matter with X-rays, neutrons, or electrons. Complementary information is achieved due to the different character of X-rays, neutrons and electrons, and hence their different interactions with matter and further practical aspects. X-ray diffraction using conventional laboratory equipment and/or synchrotron installations is the most important method for structure analyses. The purpose of this paper is to discuss special cases, for which, in addition to this indispensable part, neutrons are required to solve structural problems. Even though the huge intensity of modern synchrotron sources allows in principle the study of magnetic X-ray scattering the investigation of magnetic structures is still one of the most important applications of neutron diffraction. (K.A.)

  20. Superconducting magnetic coil

    Science.gov (United States)

    Aized, Dawood; Schwall, Robert E.

    1996-06-11

    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.