Study of HTS Wires at High Magnetic Fields

Turrioni, D.; Barzi, E.; Lamm, M.J.; Yamada, R.; Zlobin, A.V.; Kikuchi, A.

doi:10.1109/tasc.2009.2017877

Cited by 32 publications

(17 citation statements)

References 13 publications

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“…The sample used is a standard Cu stabilized YBCO 2G conductor produced by Superpower Inc. As described in [9], Fig.1. shows a top view of thermal and electrical contacts.…”

Section: B Samplesmentioning

confidence: 99%

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Quench Characteristics of a Cu-Stabilized 2G HTS Conductor

Young

Chappell

Falorio

et al. 2011

IEEE Trans. Appl. Supercond.

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Abstract-The prospect of medium/high field superconducting magnets using 2G HTS tapes is approaching to reality with continued enhancement in the performance of these conductors. Direct measurements of 1d adiabatic quench initiation and propagation of a Cu-stabilized 2G conductor have been carried out with spatial-temporal recording of temperature and voltage following the deposition of various local heat pulses to the conductor at different temperatures between 40K and 64K carrying different transport currents. It was found that the stabilizer-free 2G tape maintains the unique characteristics previously measured in non-stabilized tape of increasing MPZ with transport current and higher quench energy at lower temperatures. The minimum quench energy, minimum propagation zone (MPZ) length are determined as a function of temperature and transport current. The change in MPZ size is investigated with measured temperature dependent E-J characteristics. The results add more detail to help understand the unique characteristics of increasing MPZ with transport current and lower temperatures.

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“…The sample used is a standard Cu stabilized YBCO 2G conductor produced by Superpower Inc. As described in [9], Fig.1. shows a top view of thermal and electrical contacts.…”

Section: B Samplesmentioning

confidence: 99%

“…Both decrease linearly with temperature. From the reduced critical current the field was estimated to be ~0.1T, [9]. V0 V1 V2 V3 V4 V5 V6 V7 T0b T1 T2 T3 T4 T5 T6 T7 B 1MX-08…”

Section: A Thermal-electrical Propertiesmentioning

confidence: 99%

Quench Characteristics of a Cu-Stabilized 2G HTS Conductor

Young

Chappell

Falorio

et al. 2011

IEEE Trans. Appl. Supercond.

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“…In a first stage of this study, the critical current density in the superconductor (J c ) was taken equal to 244 A/mm 2 , i.e. the extrapolated J c value at ~40T [1]. All other properties are taken at room temperature.…”

Section: Introductionmentioning

confidence: 99%

Analytical Study of Stress State in HTS Solenoids

Barzi¹,

Terzini²

2009

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“…11,12 The HTS shim can operate even in a >12-T field and above liquid helium (LHe) temperatures. 13,14 Slim ($1-mm radial build), it can be placed inside the magnet assembly, avoiding the disadvantages inherent in the conventional NbTi shim. We believe that the HTS shim described here will become a key design option for NMR magnets, including those operated LHe-free, even at > 4:2 K. Although not restricted to GHz-class NMR magnets, 1,[15][16][17] the HTS shim may find its dddddssdsdsd application in these NMR magnets, because each >1-GHz NMR magnet contains an insert of nested HTS coils, which may collectively be modeled as a thick-walled diamagnet.…”

mentioning

confidence: 99%

“…Despite this inductive reduction, the 20-A and 40-A results demonstrate that it is possible to control shim current precisely. If operated at 4.2 K in its self field, the shim should be able to carry up to 500 A, 13,14 generating a gradient field of $50 gauss/cm, which corresponds to $200 ppm of 1-GHz (23.5 T) field. Since the field by a loop current is inversely proportional to the loop radius, the 500 A Â 1-turn single-loop HTS shim is equivalent to a 250-turn LTS shim of an average winding diameter 10 times that of the single HTS shim and operating at a typical maximum of 20 A.…”

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confidence: 99%

Persistent-mode high-temperature superconductor shim coils: A design concept and experimental results of a prototype Z1 high-temperature superconductor shim

Iwasa

Hahn

Voccio

et al. 2013

Applied Physics Letters

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Design, fabrication, and test results of a type persistent-mode high-temperature superconductor (HTS) shim coil are presented. A prototype Z1 rectangle-loop shim, cut from 46-mm wide Y-Ba-Cu-O tape manufactured by AMSC, was fabricated and tested at 77 K. The HTS shim, much thinner than the conventional NbTi shim, is placed inside the main magnet and immune to its diamagnetic wall effects. Combined with the >12-T and >10-K operation capability, the HTS shim offers a versatile design option for nuclear magnetic resonance (NMR) magnets, liquid-helium-free as well as conventional, and is particularly attractive in the next generation NMR magnets. For the NMR (nuclear magnetic resonance) superconducting magnet, its field over a target space where a specimen (the object of spectroscopy) is placed must be very homogeneous. For a high-resolution NMR magnet, this inhomogeneity can be as severe as 0.01 ppm over a 30-mm diameter spherical volume (DSV). The "raw" field of most superconducting magnets is not good enough for NMR spectroscopy and therefore it must be shimmed to a homogeneous field over the specimen volume. [1][2][3] Generally, the superconducting NMR magnet is equipped with its own set of superconducting shim coils ("shims"), currently all wound with NbTi, a low-temperature superconductor (LTS). Because of their field limitations (<12 T even at 1.8 K) and size (typically 15-30 mm radial build), NbTi shims have always been located outside the magnet assembly, i.e., radially furthest away from the magnet center where the sample is placed. This is chiefly because no superconducting shims suitable for the high-field center region have been available. Here, we describe the design concept of the high-temperature superconductor (HTS) shims and results of a prototype Z1 shim, built and operated.For a shim placed outside the magnet assembly, there are two inherent technical disadvantages: (1) at a great distance it must work harder to generate a required shimming field, i.e., a greater ampere (current)-turns (coil size); and (2) its field is attenuated by the "diamagnetic" walls of the magnet assembly, comprising many superconducting coils, as it reaches the magnet center. Worse, this field attenuation is asymmetric to the center and has strong hysteresis.Diamagnetic effect is the manifestation of a screening current induced by a field impinging on a "Bean" cylinder. 1,4-10 We may thus consider a superconducting coil as a Bean cylinder of a diamagnetic wall D thick. 4 Although D cannot be equated directly to the size of a superconductor strand, typically $50 lm for LTS and millimeters for HTS, LTS coils generally have much less attenuating and distorting effects of the diamagnetic wall than HTS coils. However, a sheer size of LTS in a typical all-LTS NMR magnet makes diamagnetic effects in LTS magnets not negligible.In this paper, we describe a design concept for superconducting shims prepared from a "wide" tape of coated YBCO HTS. 11,12 The HTS shim can operate even in a >12-T field and above liquid helium (LHe) tempe...

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Study of HTS Wires at High Magnetic Fields

Cited by 32 publications

References 13 publications

Quench Characteristics of a Cu-Stabilized 2G HTS Conductor

Quench Characteristics of a Cu-Stabilized 2G HTS Conductor

Analytical Study of Stress State in HTS Solenoids

Persistent-mode high-temperature superconductor shim coils: A design concept and experimental results of a prototype Z1 high-temperature superconductor shim

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