Bi-2212/Ag high-field magnets

Okada, Minoru; Tanaka, Kazuhide; Wakuda, T.; Ohata, K.; Sato, Junichi; Toko, Kiyoshi; Kitaguchi, Hitoshi; Wada, Hitoshi

doi:10.1016/s0921-4534(00)00143-x

Cited by 12 publications

(15 citation statements)

References 3 publications

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“…By 2000 Hitachi had developed the first and possibly the only HTS coil that became part of a high-field user magnet [43]. It replaced the inner Nb 3 Sn section of the NIMS 21.1 T superconducting magnet to create a new 50 mm bore 21.1 T LTS/HTS high-field magnet that was operated for 1.5 years 15 .…”

Section: Brief History Of Insert Coilsmentioning

confidence: 99%

“…Slight degradation of the coil performance is observed due to thermal cycling after operation at 2 K [44]. Another Hitachi-developed HTS insert reminiscent of their 1996 coil is operated in this 21.1 T background field creating a field increment of almost 2 T for a record central field of 23.42 T [43,14].…”

Section: Brief History Of Insert Coilsmentioning

confidence: 99%

“…These conductors showed relevant current density levels and little anisotropy. Layer wound solenoids equipped with persistent current switches were tested [43]. However, Hitachi ended their Bi-2212 activities before any round-wire solenoids were tested in background magnetic field, terminating the most promising HTS magnet technology development activity at the time.…”

Section: Brief History Of Insert Coilsmentioning

confidence: 99%

“…It is crucial to realize that anisotropy defined as the ratio of the J e in parallel and J e in perpendicular magnetic field has no meaning in the context of insert coils, as magnetic field angles above about 10° are unlikely in inserts 43 . APC improve flux pinning and J e most around magnetic field angles of 90 degrees, with reduced benefit for smaller angles often approaching no measurable benefit below magnetic field angles of 20° [107] or 10° degrees [94].…”

Section: Artificial Pinning Centersmentioning

confidence: 99%

“…The latter points describe the design requirements on the superconductor. The resulting plot contains both the design requirements and the anisotropic conductor properties, projected on the J e (φ) plane for the maximum 43 In the three example inserts used in this Chapter the maximum field angle is always below 7°.…”

Section: Case 3: the Average Grain Misalignment Does Not Describe Animentioning

confidence: 99%

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High-temperature superconductors in high-field magnets

Weijers

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Preface and acknowledgementThis thesis deals with selected topics out of a wide research and development effort on HTS insert coil technology. Its origin goes back to the founding charter of the NHMFL in the year 1988 which listed the goal of realizing a 25 T superconducting magnet as one of the milestones the NHMFL was to achieve. High-temperature superconductors had only just been discovered and the required technology was non-existent. The path to where we are now has been eventful and a real learning experience. From the early days in the mid-1990-ies of the 'Wind and Pray" approach when coil testing relentlessly pointed out the shortcomings of both conductor and coil technologies at the time to the first successful "mini-coils" (around coil number 70) to the successive 1 T, 3 T and 5 T inserts (the latter reaching 25 T and bringing the total of numbered coils over 300 a decade later) to the promise of 30 + T superconducting user magnets with coated conductors in the not-toodistant future.Lacking the funds to buy the very expensive conductors, a collaboration was established with industry. This approach has served us well and resulted in a wide assortment of conductors to work with. New superconductors were donated in exchange for feedback on its performance as observed in our magnet technology development program. We also tested complete coils built by ourselves or by partners, in background magnetic field, a task for which the NHMFL facilities are well suited.This work is centered on the 5T insert coil for a total magnetic field of 25 T, but the research and development effort is interwoven with and inseparable from the broader HTS insert coil technology development program. Therefore discussions on a wider range of conductors and coils in line with the broader scope of this thesis are presented.While I take full responsibility for the described NHMFL insert coil designs, analysis and interpretation of the data on coils and conductors, having executed or been directly involved with all experiments described and having wound many a coil, this work has had the benefit of many direct and indirect contributions of a large number of people inside and outside the NHMFL. In contrast, developing this thesis itself has been the loneliest work I have ever done, but ultimately just as rewarding. There are many people that I would like to thank for their contributions to the HTS insert program in general and this thesis in particular.

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Section: Brief History Of Insert Coilsmentioning

confidence: 99%