196,274 research outputs found
Superconducting Magnetic Systems for High Energy Polarized Physics
No full textThe work of this thesis has been dedicated to the interaction region of the new generation experiments using internal storage cell . The items addressed concern both the gas polarized target and the tracking magnet, that are strictly connected. The gas target consist of the combination of a polarized atomic source, and a storage cell coaxial with the beam. In the atomic source, a system of small sextupoles polarizes and focalizes the atoms, that are injected in the storage cell. The cell is immersed in a holding magnetic field that assures longitudinal or transverse polarization. The field of the tracking magnet, surrounding the interaction region, must be null where the cell is located, to keep the polarization in the cell
Study of a Sextupole Round Coil Superferric Magnet
No full textThe LASA Laboratory (INFN, Milan) is developing a new type of superferric magnets suitable to arbitrary multipole order, which we refer to as round coil superferric magnets. It is based on the previous proposal of I. F. Malyshev and V. Kashikhin. This type of magnet is suitable for strain-sensitive superconductors because it only uses a single round coil, which has a large bending radius, to create the magnetic field. The round yoke with arbitrary multipoles is able to create the desired harmonic component for the magnet. A preliminary electromagnetic design of such magnet in sextupole configuration was presented, using MgB2superconducting tape for the coil. In this paper, we present the advances in the study for the construction of the prototype. We analyze the electromagnetic properties of the coil and of the round multipole iron yoke, focusing on the optimization of the main desired multipole harmonic. We also study the mechanics and quench protection, considering a new type of MgB2superconducting cable for the coils. At the end of 2017, the magnet will be assembled in the LASA laboratories and then tested in 2018
An update on IRIS demonstrators
No full textIRIS (Innovative Research Infrastructure on applied Superconductivity) is a major project to build a research infrastructure in applied superconductivity, recently approved in Italy and led by INFN Milano. In this framework, we are developing two superconducting energy savings devices, both working at 20 K either in helium gas flow or by cold-heads: An HTS dipole (Energy Saving Superconducting Magnet) and a 1 GW rated superconducting line (Green SuperConducting Line). ESMA is an HTS ReBCO metal insulated racetrack dipole, this magnet will be 1 m long with a medium-sized round bore of 70 mm diameter and a maximum central field of 10 T. The paper reports the design updates, presenting and discussing the main technological choices (coil layout, ramping time, etc.). An R&D plan is supporting the technology choices and the construction that will be carried out in Industry will also be included. We are also developing a 130 m long MgB2 Superconducting Line (GSCL), capable of carrying 40 kA at 25 kV, an almost zero-dissipation DC transmission line. The paper will present the up-to-date status of the IRIS energy-saving devices, ESMA and GSCL: design, tests, and production
Quench Localization in the High Order Corrector Magnets using the Harmonic Field Method
No full textINFN LASA, within the CERN-INFN research collaboration for the Hi-Luminosity LHC upgrade project, has been entrusted for the series production qualification of the High Order Corrector magnets. The magnets, designed with a superferric configuration, are tested at 4.2 K in a stacked layout to evaluate the training performance and to characterize the magnetic field. This paper presents an in-depth analysis of different quench events of the High Order Corrector magnets. In this analysis, the reconstruction of the quenched coil position has been performed by measuring the residual magnetic field after the magnet has been discharged. The method used for the quench localization considers the effects of the superconductor coil magnetization, which is canceled by the transition to the normal resistive state only in the quenched coil, on the residual magnetic field. Experimental results of real events during the magnet series tests are presented and analyzed. The model previously developed for the field quality calculation has been extended to consider different quenched coils in the same event. The results are here compared and discussed. From the comparison between the model and the experimental data, the position of the quenched coil/coils has been directly retrieved for all the magnet orders and cross-checked with the acquired voltages from the magnet. The simplicity of this method and its effectiveness make it a promising way to further improve the diagnostic system of the superconducting magnets with a superferric design similar to the High Order Corrector magnets
Design and Plan of a 10 T HTS Energy Saving Dipole Magnet for the Italian Facility IRIS
No full textIRIS is a large project aiming at building a research infrastructure on applied superconductivity, recently approved in Italy, under the leadership of INFN. In this program we are currently designing an HTS dipole of nearly 1 m of length and of medium size bore, 80 mm x 50 mm, with a central field of 10 T, doubling the record field obtained in HTS dipoles. The paper reports the design of the dipole, presents and discusses the main technological choices (coil layout, finite inter-turn resistance, ramping time, etc.) and the R&D plan that will be carried out to support the technology choices and the construction that will be carried out in Industry. The dipole will be eventually used as background field in the IRIS cable test facility at Genoa (Italy)
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
A Magnesium Diboride Test Line Rated 1 GW Conceptual Design
No full textInnovative Research Infrastructure on applied Superconductivity (IRIS) is a major project to build a research infrastructure in applied superconductivity, recently approved in Italy and led by INFN. As part of this programme, we are currently designing a Green Superconducting Line (GSL), 130 m long and designed to carry 40 kA of current at 25 kV, 1 GW of power, with almost zero dissipation. The article will present the up-to-date conceptual design status for the GSL. The line will eventually be tested in the new facility being prepared by INFN-Salerno and the University of Salerno (Italy)
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A bulk superconducting MgB<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="mml7" display="inline" overflow="scroll" altimg="si1.gif"><mml:msub><mml:mrow /><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math> cylinder for holding transversely polarized targets
No full textAn innovative solution is being pursued for the challenging magnetic problem of producing an internal transverse field around a polarized target, while shielding out an external longitudinal field from a detector. A hollow bulk superconductor can trap a transverse field that is present when cooled through its transition temperature, and also shield its interior from any subsequent field changes. A feasibility study with a prototype bulk MgB2superconducting cylinder is described. Promising measurements taken of the interior field retention and exterior field exclusion, together with the corresponding long-term stability performance, are reported. In the context of an electron scattering experiment, such a solution minimizes beam deflection and the energy loss of reaction products, while also eliminating the heat load to the target cryostat from current leads that would be used with conventional electromagnets
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