Transport critical current of solenoidal MgB<sub>2</sub>/Cu coils fabricated using a wind-reaction<i>in situ</i>technique

Soltanian, Saeid; Horvat, J.; Wang, X L; Tomsic, M.; Dou, Shi Xue

doi:10.1088/0953-2048/16/1/102

Cited by 35 publications

(22 citation statements)

References 11 publications

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“…For practical applications, long wires and demonstration devices should be fabricated. Generally speaking, compared to the short samples, there will be a Jc deterioration in the long wire [18]. But the Jc property of the long pnictide wire should be still acceptable for engineering uses.…”

Section: Introductionmentioning

confidence: 99%

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Zhang

Oguro

Yao

et al. 2017

IEEE Trans. Appl. Supercond.

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Abstract-Iron-pnictides are hotly studied since 2008 in the superconducting materials research area, due to their special properties and unclear mechanism. Big achievement has been made in the pnictide research during the past years. For practical uses, pnictide superconductor should be fabricated in a long wire form which can be used for different devices. In this work, 100 m class 7-core Sr0.6K0.4Fe2As2 (Sr122) tapes have been made using the powder-in-tube technique, which is reported for the first time. Clearly, an average Jc of 1.3×10 4 A/cm 2 at 10 T was reached over the 115 meter length, showing a high property and good uniformity of 100 meter level Sr122 tapes. Using the 10 m long Sr122 tapes, two double-pancake coils were fabricated by a wind and reaction technique. No transport current could be measured for the coil made from the mono-filamentary tape. However, transport Ic was obtained in the coil made from the 7-filamentary tape. The factors which affect the superconducting property of the coil were discussed in this work.  Index Terms-Coil, critical current density, pnictide, long tape.

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Section: Introductionmentioning

confidence: 99%

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Zhang

Oguro

Yao

et al. 2017

IEEE Trans. Appl. Supercond.

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“…Soltanian, Dou, et al, [14] Musenich et al [21] reported on pancake coils wound from tape which carried 347 A at 4.2 K in the coil and generated 0.75 T.…”

Section: Introductionmentioning

confidence: 99%

Solenoidal coils made from monofilamentary and multifilamentary MgB₂strands

Sumption¹,

Bhatia²,

Buta³

et al. 2005

Supercond. Sci. Technol.

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Three solenoids have been wound and with MgB 2 strand and tested for transport properties. One of the coils was wound with Cu-sheathed monofilamentary strand and the other two with a seven filament strand with Nb-reaction barriers, Cu stabilization, and an outer monel sheath. The wires were first S-glass insulated, then wound onto an OFHC Cu former. The coils were then heat treated at 675°C/30 min (monofilamentary strand) and 700°C/20 min (multifilamentary strand). Smaller (1 m) segments of representative strand were also wound into barrel-form samples and HT along with the coils. After HT the coils were epoxy impregnated. Transport J c measurements were performed at various taps along the coil lengths. Measurements were made initially in liquid helium, and then as a function of temperature up to 30 K. Homogeneity of response along the coils was investigated and a comparison to the short sample results was made. Each coil contained more than 100 m of 0.84-1.01 mm OD strand. One of the 7 strand coils reached 222 A at 4.2 K, self field, with a J c of 300 kA/cm 2 in the SC and a winding pack J e of 23 kA/cm 2 .At 20 K these values were 175 kA/cm 2 and 13.4 kA/cm 2 . Magnet bore fields of 1.5 T and 0.87 T were achieved at 4.2 K and 20 K, respectively. The other multifilamentary coil gave similar results. Keywords Strand FabricationThe continuous tube forming/filling (CTFF) process was used to produce Table 1. For further details on these multifilamentary strands, see [24]. Coil Winding, Heat Treatment, Epoxy ImpregnationThe former was solenoidal and made from OFHC Cu. The strands for all three coils were insulated with S-glass insulation. The coils had from 364 to 538 turns of strand, see Table 2. Cu-1 was HT for 675°C/30 min, while NbCu-7A and B were HT for 700°C/20 min. The ramp up time was 2.5 h and the ramp-down time was approximately 5-6 h, and all HT were performed under flowing Ar. Coils Cu-1 and NbCu-7A were vacuum impregnated with mixed Stycast 1266 epoxy heated to 40°C. NbCu-7B was merely dipped into degassed epoxy (40°C). After removal from the epoxy bath the coil curing was performed in air (at room temperature). Total curing time was estimated at 6-12 h. Coil Measurement and ResultsTransport properties of the coils were measured in a LHe cryostat (Figure 1 shows Cu-1 mounted and ready for insertion). The 4.2 K measurements were performed in liquid He, while higher temperature measurements were made as the coil warmed up.Two Cernox temperature sensors were mounted on the coil, one on the top and one on the bottom. The temperature difference across the coil was never greater than 0.3 K. Voltage taps were placed an various places along the winding. The typical distance between successive taps was about 14-20 m. The field was measured with a cryogenic hall probe and a Bell gaussmeter calibrated to achieve a 2% or better accuracy. The probe was inserted in the center of the bore during measurement. from the strands with a Nb-chemical barrier (Table 2), as might be expected. Strand and coil J e val...

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“…Because the fabrication of MgB can occur by conventional metal-working processes, the barrier to experimentation is low. The problems of fabricating MgB conductors commercially are being addressed by Hyper Tech Research, Columbus, OH [101], Columbus Superconductors, Genova, Italy [102], Hitachi, Hitachi City, Japan, and NIMS in Japan [103], and many other laboratories worldwide, as a good recent survey makes clear [12]. Several groups have fabricated more than 100-m lengths of prototype wires.…”

Section: Magnesium Diboridementioning

confidence: 99%

Superconducting materials for large scale applications

2004

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Transport critical current of solenoidal MgB₂/Cu coils fabricated using a wind-reactionin situtechnique

Cited by 35 publications

References 11 publications

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Solenoidal coils made from monofilamentary and multifilamentary MgB₂strands

Superconducting materials for large scale applications

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Transport critical current of solenoidal MgB2/Cu coils fabricated using a wind-reactionin situtechnique

Cited by 35 publications

References 11 publications

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Superconducting Properties of 100-m Class Sr0.6K0.4Fe2As2 Tape and Pancake Coils

Solenoidal coils made from monofilamentary and multifilamentary MgB2strands

Superconducting materials for large scale applications

Contact Info

Product

Resources

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Transport critical current of solenoidal MgB₂/Cu coils fabricated using a wind-reactionin situtechnique

Solenoidal coils made from monofilamentary and multifilamentary MgB₂strands