Design of the HTS Current Leads for ITER

Ballarino, A.; Bauer, P.; Bi, Yangfan; Devred, A.; Ding, Kaizong; Foussat, A.; Mitchell, N.; Shen, Guang; Song, Yuntao; Taylor, T. Matthew; Yang, Yi; Zhou, Teng

doi:10.1109/tasc.2011.2175192

Cited by 48 publications

(11 citation statements)

References 9 publications

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“…For a full-wave flux pump under the chosen operating parameters, the resulting cryogenic heat loads during charging and maintenance modes are then 314 W and 69 W, respectively. ITER plans to use binary copper-HTS current leads [5], with an intermediate stage at 65 K. The copper stage optimally leaks about 25 W/kA to this intermediate stage [6].…”

Section: Design Parameters Of a 60 Ka Flux Pumpmentioning

confidence: 99%

“…Therefore, an reactor-like tokamak with 18 field coils would need a flux pump cryostat of only 3.6 m 3 ; comparable to a standard server rack. This may be separate from the reactor cryostat, linked by HTS current leads [5]. Additional room temperature components include the transformer and switch coil power supplies, which can be of modest size.…”

Section: Design Parameters Of a 60 Ka Flux Pumpmentioning

confidence: 99%

“…Energizing and sustaining such an inductive load at high current is extraordinarily difficult, requiring large, reactive power-electronic systems [4]. The superconducting magnets operate at cryogenic temperatures, and current must be conveyed into the cryostat using current leads [5]. Current leads inevitably leak heat into the cryostat; the amount of which depends on the current lead design [6].…”

Section: Introductionmentioning

confidence: 99%

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Design of a 60 kA Flux Pump for Fusion Toroidal Field Coils

Rice

Geng

Bumby

et al. 2022

IEEE Trans. Appl. Supercond.

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High-temperature superconducting (HTS) magnets offer a novel pathway to magnetically confined fusion energy generation. Reactor-scale fusion devices require tens of kA of current to generate large toroidal fields for magnetic confinement.Operating HTS magnets at kA-current levels is difficult due to unavoidable joint resistances that require active driving of current. The large footprint and energy demand of a solidstate power supply and multi-kA current leads present significant constraints on the size, cost and efficiency of a fusion tokamak. An alternative approach is to use an HTS flux pump, which can generate and sustain persistent currents in HTS coils at the kAlevels required by fusion magnet systems. Here, we outline the design of a 60 kA transformer-rectifier flux pump for energizing and sustaining an 80 mH HTS fusion magnet. The flux pump is driven by an iron-core transformer with copper primary and HTS secondary windings. This is rectified by switching elements in the superconducting circuit into a uni-directional dc voltage output which charges the inductive load. To charge the load coil to 60 kA in 24 hours, an output dc voltage of 55 mV is needed. However, only 6 mV is required to maintain a long-term steady current of 60 kA. Such a device can significantly reduce the cost and footprint of future fusion reactor designs.

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Section: Design Parameters Of a 60 Ka Flux Pumpmentioning

confidence: 99%

Section: Design Parameters Of a 60 Ka Flux Pumpmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Design of a 60 kA Flux Pump for Fusion Toroidal Field Coils

Rice

Geng

Bumby

et al. 2022

IEEE Trans. Appl. Supercond.

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“…They include two types of superconducting busbars: the Main Busbars (MB), supplying the TF, CS and PF coils and the Correction coil Busbars (CB) supplying the CCs. They also include 60 High Temperature Superconductor (HTS) current leads of various types [11]. The HTS lead designs rely on BSCCO 2223/Ag-Au tapes, with fin-type heat exchanger extrapolated from the HTS lead designs developed by CERN for the Large Hadron Collider (LHC).…”

Section: Iter Tokamak and Magnet Systemmentioning

confidence: 99%

Challenges and status of ITER conductor production

Devred

Backbier

Bessette

et al. 2014

Supercond. Sci. Technol.

174

118

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Taking the relay of the Large Hadron Collider (LHC) at CERN, ITER has become the largest project in applied superconductivity. In addition to its technical complexity, ITER is also a management challenge as it relies on an unprecedented collaboration of 7 partners, representing more than half of the world population, who provide 90% of the components as in-kind contributions. The ITER magnet system has a stored energy of 51 GJ and involves 6 of the ITER partners. The coils are wound from Cable-In-Conduit Conductors (CICCs) made up of superconducting and copper strands assembled into a fully transposed, rope-type cable, inserted into a conduit of butt-welded austenitic steel tubes. The conductors for the Toroidal Field (TF) and Central Solenoid (CS) coils require about 500 tons of Nb 3 Sn strands while the Poloidal Field (PF) and Correction Coil (CC) and busbar conductors need around 250 tons of Nb-Ti strands. The required amount of Nb 3 Sn strands far exceeds pre-existing industrial capacity and has called for a significant worldwide production scale up. The TF conductors are the first ITER components to be mass produced and are more than 50% complete. During its life time, the CS coil will have to sustain several tens of thousands of electromagnetic (EM) cycles to high current and field conditions, way beyond anything a large Nb 3 Sn coil has ever experienced. Following a comprehensive R&D program, a technical solution has been found for the CS conductor, which ensures stable performance versus EM and thermal cycling. Productions of PF, CC and busbar conductors are also underway. After an introduction to the ITER project and magnet system, we describe the ITER conductor procurements and the Quality Assurance/Quality Control programs that have been implemented to ensure production uniformity across numerous suppliers. Then, we provide examples of technical challenges that have been encountered and we present a status of ITER conductor production worldwide.

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“…Superconducting cables are most widely used in power systems and fusion reactors. [1][2][3][4][5] Recently, high-temperature superconductors (HTS) are also extensively utilized in areas such as magnetic-resonance imaging (MRI), fault current limiters, and magnetic energy storage. [6][7][8][9][10] The determinant in all these applications is alternating-current (AC) losses, to reduce whom a number of methods have been developed or proposed.…”

Section: Introductionmentioning

confidence: 99%

Alternating-current losses in two-layer superconducting cables consisting of second-generation superconductors coated by U-shaped ferromagnetic materials

2013

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Alternating-current losses in a two-layer superconducting cable, each layer being composed of 15 closely-spaced rectangular wires made up of second-generation superconductors when the ends of wires are coated by either a non-magnetic or strong ferromagnetic material having a U profile is numerically investigated. Computations are carried out through the finite-element method. The alternating-current losses do not increase significantly if the relative permeability of the coating is increased three orders of magnitude, provided that the current amplitude is less than half of the critical current in a superconducting wire. However, the losses are much higher for ferromagnetic coating if the amplitude of the applied current oscillating at 50 Hz is close to the critical current. The ferromagnetic coating is seen to accumulate the magnetic field lines normally on its surfaces, while the field lines are parallel to the long axes of the wires, leading to more significant flux penetration in the coated regions. This facilitates a uniform low-loss current flow in the uncoated regions of the wires. In contrast, coating with a non-magnetic material gives rise to a considerably smaller current flow in the uncoated regions, whereas the low-loss flow is maintained in the coated regions. Moreover, the current flows in opposite directions in the coated and uncoated regions, where the direction in each region is converse for the two materials.

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Design of the HTS Current Leads for ITER

Cited by 48 publications

References 9 publications

Design of a 60 kA Flux Pump for Fusion Toroidal Field Coils

Design of a 60 kA Flux Pump for Fusion Toroidal Field Coils

Challenges and status of ITER conductor production

Alternating-current losses in two-layer superconducting cables consisting of second-generation superconductors coated by U-shaped ferromagnetic materials

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