High-Field Characteristics of Superconducting Wires Measured in a Pulsed Magnet

In this article, we examine materials behavior in the magnetic field region from about 40 T to 500 T using pulsed magnet technology. Examples of materials science using two different pulsed magnet technologies are described in this article.Semicontinuous MagnetsSince the late 1960s, the University of Amsterdam has operated a semicontinuous magnetic field installation that produces magnetic fields up to 40 T with typical time constants of about one second. The magnet coil is constructed from hard-drawn copper wire with a reinforcement cylinder of maraging steel positioned at roughly one third of the outer diameter. Before operation, the coil is cooled to 30 K by cold neon gas. The power for this installation is taken directly from a 10 kV connection to the public electricity grid. By means of a thyristor-based power control system, highly flexible field-time profiles can be realized: step-wise pulses can be generated with field levels constant within 10−4 during 100 ms; linearly increasing and decreasing fields as well as exponentially ripple-free decreasing fields are other examples of standard field-time profiles. Among the measuring techniques frequently used are magnetization, magneto-transport, quantum oscillations, relaxation phenomena, etc. Temperatures at which experiments can be performed range from 400 mK to room temperature. In the Netherlands, the Amsterdam High Field Facility has recently been combined with the High Magnetic Field Laboratory in Nijmegen, where static magnetic fields up to 30 T are produced in hybrid magnet systems, to form the Amsterdam-Nijmegen Magnet Laboratory (ANML). The high field research of ANML comprises semiconductors, magnetism in transition-metal compounds, heavy-fermion physics, superconductors, organic conductors, and magnetic separation. We present here a few selected topics.

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High-Field Pulsed Magnet Wound of Cu-Ag Alloy Wire

Japanese Journal of Applied Physics ◽

10.1143/jjap.32.l1027 ◽

1993 ◽

Vol 32 (Part 2, No. 7B) ◽

pp. L1027-L1029 ◽

Cited By ~ 12

Author(s):

Toshihisa Asano ◽

Yoshikazu Sakai ◽

Kiyoshi Inoue ◽

Mitsutake Oshikiri ◽

Hiroshi Maeda

Keyword(s):

High Field ◽

Alloy Wire ◽

Pulsed Magnet

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High-Strength Nb3Sn Wire Development for Compact Superconducting Magnets

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.1841 ◽

2007 ◽

Vol 546-549 ◽

pp. 1841-1848 ◽

Cited By ~ 2

Author(s):

K. Watanabe ◽

Satoshi Awaji ◽

Gen Nishijima

Keyword(s):

High Field ◽

Magnetic Energy ◽

Superconducting Magnets ◽

Small Diameter ◽

High Strength ◽

Superconducting Magnet ◽

Hybrid Magnet ◽

Superconducting Wires ◽

External Reinforcement ◽

Nb3sn Strand

A superconducting magnet with a magnetic energy of E = B2/2μo [J/m3] has to overcome a magnetic force of P = B2/2μo [Pa] in the same expression. This means that a high-field 20 T superconducting magnet produces an electromagnetic force of 160 MPa. In order to stand such a large force, Nb3Sn superconducting wires are usually reinforced by the hard-copper housing as an external reinforcement method or the stainless steel winding as a mechanical backup of an outermost Nb3Sn coil. If we focus on a compact superconducting magnet like a cryocooled superconducting magnet, a high-strength superconducting wire with a small diameter size of 1- 2 mm is required. The High-Field Laboratory for Superconducting Materials, IMR, Tohoku University has developed Nb3Sn wires internally reinforced with CuNb or CuNbTi composite. These high-strength Nb3Sn wires were successfully employed to construct the unique compact cryocooled 28 T hybrid magnet and the cryocooled 18 T high-temperature superconducting magnet. In addition, we found that the prebending effect for high-strength Nb3Sn wires outstandingly improves the Tc, Bc2 and Ic properties. As a next step, we intend to develop new Nb3Sn strand cables with the strong mechanical property of 500 MPa, applying the prebending effect for a future 22 T-φ400 mm room temperature bore superconducting magnet of a 50 T-class hybrid magnet.

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Recent R&D on Superconducting Wires for High-Field Magnet

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.2081 ◽

2014 ◽

Vol 783-786 ◽

pp. 2081-2090 ◽

Cited By ~ 4

Author(s):

Xin Zhe Jin ◽

Tatsushi Nakamoto ◽

Kiyosumi Tsuchiya ◽

Akira Yamamoto ◽

Toru Ogitsu ◽

...

Keyword(s):

Critical Current ◽

High Field ◽

Materials Science ◽

Rapid Heating ◽

High Temperature Superconductors ◽

Experimental Studies ◽

High Energy ◽

Superconducting Wires ◽

Neutron Diffractometer ◽

High Field Magnet

Development for superconducting wires of materials such as Nb3Al and the high-temperature superconductors (HTS such as REBCO, Bi2223, and Bi2212) has been carried out for high-field magnet applications. It is known that these types of wire exhibit very different characteristics and performance for different applications. The development of Nb3Al wire for high-field accelerator magnet has resulted in remarkable achievements in critical current using a Rapid Heating and Quenching (RHQ) method by High Energy Accelerator Research Organization (KEK) and National Institute for Materials Science (NIMS). As one example of a characteristic of Nb3Al, the strain sensitivity of the critical current in the RHQ-Nb3Al wire is better than that of Nb3Sn wire. A strain study is needed to further the development of a high-filed magnet; therefore, we have carried out experimental studies using the neutron diffractometer at J-PARC Takumi. Researchers have recently achieved the highest critical current density for REBCO wires in a high-field above 15 T. For this reason, REBCO wire has been considered for high-field magnet NMR applications in Riken. But several obstacles remain, including coil degradation, shielding current and thermal runaway. In this paper, R&D on recent advances for applications will be presented.

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Mechanical design of a dual-cryostat instrument for a high-field pulsed magnet

Diamond Light Source Proceedings ◽

10.1017/s2044820110000730 ◽

2010 ◽

Vol 1 (MEDSI-6) ◽

Cited By ~ 1

Author(s):

D. Capatina ◽

Z. Islam ◽

E. Trakhtenberg ◽

H. Nojiri ◽

Y. Narumi

Keyword(s):

Liquid Nitrogen ◽

High Field ◽

Mechanical Design ◽

Closed Cycle ◽

Pulsed Magnet ◽

Magnet Coil ◽

Liquid Nitrogen Cooling ◽

Photon Source ◽

Cycle Refrigerator ◽

Closed Cycle Refrigerator

The engineering of a dual-cryostat for a pulsed-magnet instrument at the Advanced Photon Source is presented. The dual-cryostat independently cools the magnet coil (using liquid-nitrogen) and the sample (using a closed-cycle refrigerator). Liquid-nitrogen cooling may allow a repetition rate of a few minutes for peak fields near 30 T. The system is unique in that the liquid-nitrogen cryostat incorporates a double-funnel vacuum tube passing through the solenoid's bore in order to preserve the entire angular range allowed by the magnet bore for scattering studies. Second, the use of a separate refrigerator for the sample allows precise positioning of samples in the bore while minimizing magnet vibrations propagating to the sample during pulsed-field generation.

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