Development of a 20 kA high temperature superconductor current lead

Heller, R.; Friesinger, G.; Fuchs, A.M.; Mito, T.; Satoh, Shuichi; Takahata, K.; Tasca, M.; Vögel, Martin

doi:10.1016/s0011-2275(01)00101-1

Cited by 16 publications

(9 citation statements)

References 15 publications

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“…The HTS part manufactured by American Superconductor (AMSC) is cooled by heat conduction from the 4.5 K end and the HEX part manufactured in the Forschungszentrum Karlsruhe is cooled with 50 K helium gas. This concept was also successfully applied in the former 20 kA HTS current lead program [1], [4]. The results of optimization studies indicate that a broad minimum of the required refrigerator input power is reached at a temperature of 65 K at the warm end of the HTS and the use of 50 K helium gas to cool the HEX part of the current lead [5].…”

Section: Description Of the Hts Current Leadmentioning

confidence: 99%

Experimental Results of a 70 kA High Temperature Superconductor Current Lead Demonstrator for the ITER Magnet System

Heller

Darweschsad

Dittrich

et al. 2005

IEEE Trans. Appl. Supercond.

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In the frame of the European Fusion Technology Programme, the Forschungszentrum Karlsruhe and the CRPP Villigen have designed and built a 70 kA current lead for the ITER TF Coils using High Temperature Superconductors (HTS). At the beginning of 2004 the HTS current lead was installed and tested in the TOSKA facility of the Forschungszentrum Karlsruhe. The scope of the experiment was to characterize the current lead in steady state conditions and to explore the operation limits as well. For this, the temperature profile, the contact resistances, the heat load at 4.5 K, the required 50 K He mass flow rate, and the temperature margin were evaluated. The safety margin in case of a loss of He mass flow was studied, too. The paper describes the experimental results as well as the thermal and electrical models developed.Index Terms-Current leads, fusion magnets, high temperature superconductor.

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Section: Description Of the Hts Current Leadmentioning

confidence: 99%

Experimental Results of a 70 kA High Temperature Superconductor Current Lead Demonstrator for the ITER Magnet System

Heller

Darweschsad

Dittrich

et al. 2005

IEEE Trans. Appl. Supercond.

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“…For example, and can be determined with the least squares fitting when the measurements are repeated at different values of . Finally (5) and the total heat leak in the lead can be estimated as . It is worth noting that in practice depends on .…”

Section: Thermal Resistances and Heat Leakmentioning

confidence: 99%

“…HTS current leads are usually made with HTS tapes or with a HTS bulk in between high conductivity copper terminals. When the HTS bulk is used the heat load can be four times smaller compared to the HTS tapes [5]. However, then there can be problems with electrical and mechanical stability [6].…”

Section: Introductionmentioning

confidence: 99%

Measured Performance of Different Solders in Bi2223/Ag Current Leads

Hiltunen

Korpela

Laine

et al. 2008

IEEE Trans. Appl. Supercond.

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In superconducting magnet systems the current leads are usually divided into two parts. Normal metal like brass or copper is often used in the first part from the room temperature to the temperature of the radiation shield. The second part down to the magnet is made of high temperature superconductors (HTS). HTS leads can reduce the conductive heat load because they have poor thermal conductivity. Since HTS wires are lossless with direct current and have fair tolerance to the magnetic field only Ohmic losses are generated in the contact resistances at the current terminals. Thus, efficient current leads require that appropriate solders are used to reduce the contact resistances. In this paper, the thermal and contact resistances as well as thermal conduction losses of Bi-2223/Ag current leads are experimentally investigated using indium-and tin-based solders at operation temperatures between 20 and 77 K. Finally, the measured data is utilized to design an efficient HTS current lead to the current range of 0-1000 A.

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“…The HTS module is cooled by heat conduction from the 4.5 K level and the copper part is cooled with 50 K helium. This concept was also successfully applied in the former 20 kA HTS current lead program [10,11]. The optimum temperatures of both the helium and the conductor at the cold end of the heat exchanger depend on the assumed refrigerator efficiency, the engineering critical current density of the Bi-2223 tapes at the warm end operating temperature and the cross-section of the stainless steel support.…”

Section: Hts Current Leadmentioning

confidence: 99%