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1.
A novel insertion device for electron storage rings called the MAX-Wiggler has been constructed at MAX-lab. The MAX-Wiggler is a cold bore superconducting wiggler magnet with 47 3.5-T poles and a period length of 61 mm aimed for the production of X-rays at the 1.5-GeV electron storage ring MAX-II at MAX-lab. The MAX-Wiggler consists of 98 racetrack coils connected in series in the superconducting magnet and the total stored magnetic energy at the nominal maximum field strength of 3.5 T is 48 kJ. This paper describes the quench analysis of the magnet. Several protection schemes have been evaluated, such as an external dump resistor and safety switch or subdivision of the series of coils into sections with shunt resistors or silicon diodes in parallel to each group of coils in a section. It has been found that the most suitable protection scheme, in order to prevent the superconducting coils from getting overheated, is subdivision with a shunt path containing silicon diodes operating at liquid helium temperatures. The MAX-Wiggler has been commissioned and it has survived the quenches occurring during the initial training of the superconducting coils. 相似文献
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B. N. Hubert R. Zhou T. G. Holesinger W. L. Hults A. Lacerda A. S. Murray R. D. Ray CM. Buford L. G. Phillips A. Kebede J. L. Smith 《Journal of Electronic Materials》1995,24(12):1869-1872
The silver cladding for high-temperature superconducting wire can be modified for various applications by alloying. For example,
for powder-in-tube wire, stiffer cladding improves the smoothness of the interface. For large coils, higher strength is needed
at low temperatures to hold them together. Power applications require more resistance in the cladding. We have made a survey
of the properties of alloys to check their feasibility for various applications. Alloys with several elements added to silver
have been prepared and evaluated for hardness, electrical properties, and compatibility with high-temperature superconductors
during processing. 相似文献
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《Applied Superconductivity, IEEE Transactions on》2009,19(4):3645-3652
6.
The use of Fourier-transform techniques provides exact integral expressions for the forces on polygonal dc current coils moving over a conducting sheet. These expressions are applied to investigate magnetic levitation of proposed high-speed transportation. Extensive numerical data have been analyzed to determine the performance dependence of the system parameters such as velocity, coil shape, array configuration, clearance, and track thickness, conductivity and permeability. In terms of potential applications, a comparison between the superconducting repulsive and ferromagnetic attractive systems is given. 相似文献
7.
CSIRO has had a long-term research effort in superconductivity, in particular, since the discovery of HTS which promised big prospects. Significant progress has been made in research and development of HTS electronic devices and systems for practical applications such as mineral and exploration as well as some niche applications in emerging science and technology areas. This article presents an overview of the CSIRO research activities in HTS superconducting electronics since 1987, outlining the HTS junction and device technology as well as various application systems develop by the group. 相似文献
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D. U. Gubser 《Journal of Electronic Materials》1995,24(12):1843-1850
Superconducting bismuth-cuprate wires, coils, and magnets are being produced by industry as part of a program to test the
viability of using such magnets in Naval systems. Tests of prototype magnets, coils, and wires reveal progress in commercially
produced products. The larger magnets will be installed in an existing superconducting homopolar motor and operated initially
at 4.2K to test the performance. It is anticipated that approximately 400 Hp will be achieved by the motor. This article reports
on the initial tests of the magnets, coils, and wires as well as the development program to improve their performance. 相似文献
9.
Minseok Joo Tae Kuk Ko 《Applied Superconductivity, IEEE Transactions on》1999,9(3):4613-4618
An improved model of the current limiting devices such as the high-Tc superconducting fault current limiter (SFCL) and the reactor have been developed. The high-Tc SFCL mainly consists of the primary copper coil, the secondary high-Tc superconducting rings, and the damping coils, which are magnetically coupled through a three-legged magnetic core. Because a portion of the magnetic flux above the saturation point generated by the fault current is cancelled by the damping coil, thereby the magnetic core is prevented from getting into the saturated state. The limiting current level and the saturation of the core could be controlled by the air-gap length of the central leg with the damping coil. A new design of the SFCL is found to increase the effective impedance by about 60 to 70%, compared to the SFCL design without the damping coils 相似文献
10.
CSIRO has had a long-term research effort in superconductivity, in particular, since the discovery of HTS which promised big prospects. Significant progress has been made in research and development of HTS electronic devices and systems for practical applications such as mineral and exploration as well as some niche applications in emerging science and technology areas. This article presents an overview of the CSIRO research activities in HTS supercon- ducting electronics since 1987, outlining the HTS junction and device technology as well as various application systems developed by the group. 相似文献
11.
Kalsi S.S. Szczepanowski A. Snitchler G. Picard H. Sidi-Yekhlef A. Connor B. Schwall R.E. MacKinnon B. Tallon J.L. Todd G. Neale R. 《Applied Superconductivity, IEEE Transactions on》1998,8(1):30-33
This paper describes the design, construction, and testing of an ion beam switching high-temperature superconducting (HTS) magnet installed at Institute of Geological and Nuclear Science (IGNS) in New Zealand. It was designed by a consortium comprising American Superconductor Corporation (ASC), ISYS, Applied Engineering Technologies (AET), the New Zealand Institute for Industrial Research and Development (IRL), and Alphatech. The work was also supported in part by New Zealand Foundation for Research and Technology-Technology for Business Growth Programme. The magnet generates 0.72 T in the airgap between two 410×700 mm warm iron poles. The Bi-2223 HTS coils are conduction-cooled with a single stage Gifford-McMahon (G-M) type cryocooler for steady-state operation. The magnet was fully tested at ASC during the fall of 1996. This represents the first large-scale fully operational HTS physics magnet announced so far. The successful operation of this magnet has verified maturation of HTS magnet technology employing conduction cooling techniques with G-M type cryocoolers. Long term operation of this magnet in continuous use will prove the reliability of HTS magnet systems in critical applications and is expected to open future opportunities for HTS in other related areas 相似文献
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Bellesia B. Remondino V. Scandale W. Todesco E. Vollinger C. 《Applied Superconductivity, IEEE Transactions on》2004,14(2):219-222
The Large Hadron Collider (LHC) (1995), a proton-proton superconducting accelerator, will consist of about 8400 superconducting magnet units, all operating in superfluid helium at a temperature of 1.9 K. The design of the superconducting main dipole magnets for the LHC is guided by the requirement of an extremely high field quality in the magnet aperture which is mainly defined by the layout of the superconducting coil and the position of the conductors. In order to avoid conductor movements within the magnet cross-section, the superconducting coils are held in place by surrounding stainless steel collars. In this paper, we review the dependence of field harmonics in the LHC main dipoles on dimensions of the hardware components of the collared coils. An analysis of the dimensional measurements of these components which are used in the collared coils produced so far is given. Sensitivity tables which are worked out through a coupled magneto-static model give the variation of the multipoles on collars, copper wedge dimensions and cable geometry. A Monte Carlo method is used to simulate the effects of possible errors on the multipoles. 相似文献
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介观系统中的电导量子化 总被引:1,自引:0,他引:1
对介观系统电子输运性质的研究是当前凝聚态物理研究中的活跃领域。介观尺度下,由于量子力学效应,出现了一些特殊的物理现象,如电导量子化。本文从理论和实验两方面对介观输运领域的研究情况作了简要回顾,介绍了一些较新的研究成果,并讨论了电导量子化在下一代集成电路中可能的应用方向。 相似文献
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Kroger H. Hilbert C. Gibson D.A. Ghoshal U. Smith L.N. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1989,77(8):1287-1301
The discovery of superconductors whose critical temperatures are above liquid nitrogen temperature has prompted considerable interest in hybrid superconducting-semiconducting electronics applications. The authors review the efforts to hybridize these technologies. Some of these efforts have already been demonstrated on a laboratory scale; others are at present just theoretical proposals. Hybridization is possible on the system, circuit, and device levels. The authors review studies of the applications of superconductors for interconnecting semiconductor systems and combining semiconductor and superconductor devices to enhance the performance of both digital and analog systems. Novel circuit combinations of superconducting and semiconducting devices are mentioned, as are proposals to combine these materials on the device level. It is noted that the use of hybrid combinations may permit some electronic functions to be performed better than either technology could perform separately 相似文献
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《Applied Superconductivity, IEEE Transactions on》2008,18(3):1692-1697
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《Applied Superconductivity》1999,6(6):247-257
A new design concept of the axisymmetric magnet system generating the very high pulsed magnetic field which is superimposed on the bias magnetic field of the superconducting magnet is presented. The pulsed magnet consists of two coaxial coils which are wound in opposite directions. The geometry of both pulsed coils, i.e. the working (inner) one and the compensating (outer) one is designed in such a way that the mutual coupling between the small pulsed magnet and the outer superconducting magnet is practically zero. This configuration prevents the rise of the high induced voltage on the current leads of the superconducting magnet when the pulsed magnet is being energised, hence resulting naturally in protection of the system (superconducting magnet and the current source) against possible damage. Further, it is predicted that the stray field of the pulsed magnet, which gives rise e.g. to the eddy currents in the winding of the superconducting magnet, is considerably decreased. The simple theory enabling the design of the geometry of the compensating pulsed coil is derived. The advantages of this new concept are demonstrated on the results of the theoretical analysis using, as an example, one of the pulsed coils that were designed and fabricated in the Clarendon Laboratory, in connection with the Oxford Instrument superconducting magnet (Clarendon hybrid outer) which can generate a steady magnetic field up to 10 T in a room temperature working space with a diameter of 240 mm. 相似文献
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We propose a general theory to analyse and design the wireless power transfer (WPT) systems based on impedance matching. We take two commonly used structures as examples, the transformer-coupling-based WPT and the series/parallel capacitor-based WPT, to show how to design the impedance matching network (IMN) to obtain the maximum transfer efficiency and the maximum output power. Using the impedance matching theory (IMT), we derive a simple expression of the overall transfer efficiency by the coils’ quality factors and the coupling coefficient, which has perfect accuracy compared to full-circuit simulations. Full-wave electromagnetic software, CST Microwave Studio, has been used to extract the parameters of coils, thus providing us a comprehensive way to simulate WPT systems directly from the coils’ physical model. We have also discussed the relationship between the output power and the transfer efficiency, and found that the maximum output power and the maximum transfer efficiency may occur at different frequencies. Hence, both power and efficiency should be considered in real WPT applications. To validate the proposed theory, two types of WPT experiments have been conducted using 30 cm-diameter coils for lighting a 20 W light bulb with 60% efficiency over a distance of 50 cm. The experimental results have very good agreements to the theoretical predictions. 相似文献
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Sivasubramaniam K. Huang X. Laskaris E. T. Zhang T. Bray J. W. Forgarty J. M. Nold R. A. 《Applied Superconductivity, IEEE Transactions on》2006,16(4):1971-1975
High-temperature superconducting (HTS) coils are generally stable against transient thermal disturbances. Protection against spontaneous quenches is not a main design issue for an HTS coil. However, HTS coils used in many electric devices such as motors, generators, transformers, and current limiters will operate under over-current fault conditions, which may result in a coil quench and thermal runaway. Those electric devices should be able to ride through some grid fault conditions and remain functional. This requires a certain over-current capability of the HTS coils. This paper discusses the over-current requirements from grid faults and the thermal transient responses of a BSCCO coil. It presents the analysis results of the coil subjected to over-current pulses at different operating conditions. The study also investigates the thermal runaway current and its relationship with the over-current pulse 相似文献
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Donald U. Gubser Thomas L. Francavilla Robert J. Soulen Dean L. Mitchell 《Journal of Electronic Materials》1993,22(10):1305-1309
The Navy has had a long standing interest in power applications of superconductivity. Recent advances in high temperature
superconducting (HTS) materials have caused the Navy science and technology community to assess the potential of HTS magnets
for Naval applications. A program has begun to test HTS conductors and magnets in order to determine realistic performance
expectations from which to determine proper systems integration. This paper presents some early results of industrially produced
HTS magnets and discusses possible Naval applications. Speculative application toward magneto-hydrodynamic (MHD) propulsion
is also discussed-specifically with respect to HTS materials. 相似文献
20.
Balsamo E.P. Gislon P. Pasotti G. Ricci M.V. Spadoni M. Minervini J.V. Vysotsky V.S. 《Applied Superconductivity, IEEE Transactions on》2000,10(2):1598-1602
It is believed that critical current reduction in multistrand superconducting cables at nonsteady state conditions is caused by a nonuniform current distribution among strands. This was experimentally proven for small model cables, but is still not verified for large cables. In the ENEA Frascati Laboratory, an ITER relevant, large superconducting magnet has been tested at different field ramp rates. By means of numerous local miniature field sensors (Hall probes and pickup coils) located in a few positions along the conductor, current redistribution phenomena inside the cable have been studied. Fast and slow local field changes have been studied to quantify the current nonuniformity. It has been shown that severe current nonuniformity does exist in the cable and that induced current loops are generated, which decay with very long time constants (up to 104-105 s) 相似文献