The Effects of a Stabilizer Thickness of the YBCO Coated Conductor (CC) on the Quench/Recovery Characteristics

Kwon, Na Young; Kim, H S; Kim, K L; Hahn, Seungyong; Kim, H.-R; Hyun, Ok-Bae; Kim, H M; Kim, W S; Park, C; Lee, H G

doi:10.1109/tasc.2009.2039864

Cited by 19 publications

(4 citation statements)

References 6 publications

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“…We used a chemical etching method to remove a predetermined length of the stabilizers covering the GdBCO to expose a portion of the bare GdBCO surface without degrading the superconductivity. [19][20][21][22] The ends of two bare GdBCO CCs are overlapped by rotating one CC 1801 (to form a lap-type joint). The exposed portions of the superconducting layers are held together, and pressure is applied.…”

Section: Methodsmentioning

confidence: 99%

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

et al. 2014

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Second-generation (2G) GdBCO-coated conductors (CCs) are promising for superconducting magnet applications because of their high critical current (I c ) density, low dependency of the I c on the external magnetic field, good mechanical properties and reasonable cost, which offer opportunities to develop ultra-high-field magnets. However, they have not been used in hightemperature superconducting (HTS) applications with persistent current mode (PCM) operation such as nuclear magnetic resonance/magnetic resonance imaging magnets owing to unavailability of fabrication techniques for proper joining and contacts. Here we report a resistance-free joint, termed a 'superconducting joint', for 2G GdBCO CCs that forms a direct connection to establish a superconducting closed loop for PCM operation. The I c value of the joined CCs is identical to that of the parent conductors in a liquid nitrogen bath (77 K). Moreover, the initially induced magnetic field of a model GdBCO coil containing a superconducting joint is maintained without decreasing, indicating the complete absence of electrical resistance. Thus, this fabrication method is a unique practical solution for lengthening the 2G HTS CCs and, more importantly, achieving PCM operation in 2G HTS magnet applications, including ultra-high-field nuclear magnetic resonance/magnetic resonance imaging magnets generating more than 1 GHz.

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Section: Methodsmentioning

confidence: 99%

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

et al. 2014

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“…To establish a GdBCO-GdBCO CC joint, the Ag stabilizer layer on top of the GdBCO layer had to be eliminated and chemical etching was used. The etchant (silver etchant TFA from Transene) was diluted with de-ionized water (50% by weight) to moderate the etching reaction to achieve a homogeneously etched surface [38][39][40][41].…”

Section: Effects Of Procedures For Laser Drilling and Etching Processmentioning

confidence: 99%

Laser drilling: enhancing superconducting joint of GdBa₂Cu₃O_{7 −δ}coated conductors

Park

Lee

et al. 2014

Supercond. Sci. Technol.

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While GdBa 2 Cu 3 O 7 − δ (GdBCO) coated conductors (CCs) have been proposed for superconducting applications, they have not been used in devices with persistent current mode (PCM) operation because of a lack of joining techniques. A superconducting joint of CCs, formed via melting diffusion and oxygenation annealing, offers no electrical resistance between the CCs, thus establishing a superconducting closed loop for PCM operation. Because superconductivity degrades with oxygen out-diffusion during melting diffusion, oxygenation annealing allows oxygen diffusion into the GdBCO lattices. As effective oxygenation annealing requires oxygen pathways in the joint, low solubility and diffusivity of oxygen in the buffer and CC substrate hinder full superconductivity recovery. Here we show a laser-drilling technique to produce microholes as conduits on the surfaces of GdBCO CCs' to promote oxygen in-diffusion, which resulted in reduced superconductivity recovery time. Superconductivity was fully recovered after laser drilling, melting diffusion at 850 °C for 1 min, and oxygenation annealing at 500 °C for 350 h.

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“…It is necessary to focus on studying the quenching characteristic of YBCO material to realize the engineering application of R-SFCL. At present, many scholars have conducted extensive and in-depth research on the different characteristics of YBCO superconducting tape including quenching behavior under AC or DC overcurrent [15,16,17,18,19,20,21,22], quench propagation [23,24,25,26], quenching recovery [27,28,29,30], thermal and mechanical properties [31,32], minimum quench energy [33,34], maximum operating condition [35], and the effect of different materials on quenching behavior [36,37,38], which provide a solid foundation for the use of superconducting tape in design and fabrication of R-SFCL. However, there are few studies on common characteristics of quenching resistance of 2G HTS tape under AC and DC overcurrent, which is necessary and basic for R-SFCL design and research.…”

Section: Introductionmentioning

confidence: 99%

Study on Quenching Characteristics and Resistance Equivalent Estimation Method of Second-Generation High Temperature Superconducting Tape under Different Overcurrent

Liang

Ren

et al. 2019

Materials

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In this paper, through AC and DC overcurrent tests on second generation high temperature superconducting tape (2G HTS tape), we respectively summarize the typical types of quenching resistance and corresponding quenching degree, in which there are three types under AC overcurrent and two types under DC overcurrent. According to experimental results, a rule was found that, when 2G HTS tape quenches to normal state, the relationship between quenching resistance and joule heat generated from 2G HTS tape presents a fixed trend line, and the influence of liquid nitrogen can be ignored. Then, the characteristics and rules of quenching resistance found in experiments are well explained and confirmed by a detailed 3D finite element model of 2G HTS tape including electromagnetic field and thermal field. Finally, based on above works, our group proposes a new equivalent method to estimate the quenching resistance, where the results of AC and DC overcurrent experiments can be equivalent to each other within a certain range. Compared with FEM, the method has the following advantages: (i) The method is simple and easy to implement. (ii) This method combines precision and computational efficiency. (iii) With superconducting tape quenching to normal state, this method presents a good consistency with experimental results.

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The Effects of a Stabilizer Thickness of the YBCO Coated Conductor (CC) on the Quench/Recovery Characteristics

Cited by 19 publications

References 6 publications

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

Laser drilling: enhancing superconducting joint of GdBa₂Cu₃O_{7 −δ}coated conductors

Study on Quenching Characteristics and Resistance Equivalent Estimation Method of Second-Generation High Temperature Superconducting Tape under Different Overcurrent

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The Effects of a Stabilizer Thickness of the YBCO Coated Conductor (CC) on the Quench/Recovery Characteristics

Cited by 19 publications

References 6 publications

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

A superconducting joint for GdBa2Cu3O7−δ-coated conductors

Laser drilling: enhancing superconducting joint of GdBa2Cu3O7 −δcoated conductors

Study on Quenching Characteristics and Resistance Equivalent Estimation Method of Second-Generation High Temperature Superconducting Tape under Different Overcurrent

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Laser drilling: enhancing superconducting joint of GdBa₂Cu₃O_{7 −δ}coated conductors