Test Results of the High Temperature Superconductor Prototype Current Leads for Wendelstein 7-X

Heller, R.; Drotziger, S.; Fietz, W.H.; Fink, S.; Heiduk, M.; Kienzler, A.; Lange, Christian; Lietzow, R.; Möhring, Tobias; Rohr, P.C.; Rummel, Thomas; Mönnich, T.; Buscher, Klaus-Peter

doi:10.1109/tasc.2010.2096371

Cited by 25 publications

(15 citation statements)

References 8 publications

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“…3 (bottom) the left hand side shows the warm end of the CL at room temperature whereas the right hand side is the 60 K region at the transition to the HTS module. A more detailed description can be found in [4]. Fig.…”

Section: B Hts Insert and Heat Exchangermentioning

confidence: 99%

Current Leads for the Wendelstein 7-X Superconducting Magnet System

Rummel

Schauer

Moennich

et al. 2014

IEEE Trans. Plasma Sci.

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Abstract-The stellarator fusion experiment Wendelstein 7-X (W7-X) is presently under assembly at the Greifswald branch of the Max Planck Institute for Plasma Physics (IPP), Germany. The W7-X superconducting magnet system basically consists of 50 non planar and 20 planar coils including the interconnecting bus bars, and the support structure. The seven electrical circuits with ten coils each in series, are supplied by 14 current leads (CL) operating between the cryogenic and ambient temperature environments. A special feature of these feed throughs is their upside-down orientation to save space in the vicinity of the machine. Basic electrical CL requirements are maximal steady state currents of 18.2 kA and voltage strengths of 13 kV to ground. A W7-X current lead consists of a copper conductor which also acts as a heat exchanger at the warm end side, in its continuation of a high temperature superconductor (HTS) part, and at the cold end side of a copper bar with integrated Nb 3 Sn rods. All components are fully contained within a CL vacuum chamber which is separated from the main W7-X cryostat vacuum. The high voltage electrical insulation is built up of a glass tape epoxy resin system. Mechanical support of the current leads is achieved by a warm and cold glass fiber reinforced plastic flange. There are three He cooling circuits: one for the bus bar and contact cooling, one for the cold end of the CL (both at about 5 K), and one for the CL's heat exchanger (entrance temperature about 50 K). After intensive tests of two prototypes the series production has been established and completed. The current leads were tested at room temperature (high voltage, helium leaks, instrumentation, etc.), and with electrical currents up to the maximum current at cryogenic temperatures. The paper gives an overview of the basic CL design requirements and layout as well as on the fabrication and acceptance tests. Further, a description of the assembly progress is given.

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Section: B Hts Insert and Heat Exchangermentioning

confidence: 99%

Current Leads for the Wendelstein 7-X Superconducting Magnet System

Rummel

Schauer

Moennich

et al. 2014

IEEE Trans. Plasma Sci.

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“…The test comprises the following parts [13]: Measurement of heat load at 4.5 K with zero current, steady state operation at currents up to 20 kA and long time test with 18.2 kA, ramp tests (simulating W7-X operation), Quench tests, Loss of mass flow (LOFA) tests.…”

Section: Current Leadsmentioning

confidence: 99%

The Superconducting Magnet System of the Stellarator Wendelstein 7-X

Rummel

Riße

Ehrke

et al. 2012

IEEE Trans. Plasma Sci.

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Abstract-The stellarator fusion experimental device Wendelstein 7-X (W7-X) is presently under assembly at the Greifswald branch of the Max-Planck-Institut für Plasmaphysik (IPP), Germany. The superconducting magnet system consists of 50 non planar coils, 20 planar coils, a superconducting bus system and 14 current leads. It is organized in seven electrical circuits with ten coils, the bus system for the interconnection and two current leads each. The magnet system is cooled by supercritical helium. It is enclosed in a cryostat with an outer diameter of 16 meters formed by the plasma vessel and the outer vessel. There are five different types of non planar coils having dimensions of 3.5 x 2.5 x 1.5 meters in maximum and a weight of about 5.5 tons. The two different types of the planar coils are nearly circular coils with a diameter of up to 4.5 meters and a weight of about 3 tons. The superconducting bus bar system connects the coils to each other and provides the connection to the current leads inside the cryostat. All types of coils and the bus system use the W7-X superconductor, a forced flow cable-in-conduit superconductor with 243 copper stabilized NbTi strands with an outer aluminumalloy jacket. The current leads provide the transfer of the electrical current from the room temperature bus bar system outside the cryostat to the superconducting parts inside the cryostat. Their special feature is the upside down orientation with the cold end at the top.

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“…The standard voltage level was 10 mV with 100 ms integration time. For some special experiments the voltage level was increased to 50 mV (details see [4]). 5 gives an overview of the W7-X CL prototype test with cool down, experimental campaign and warm up.…”

Section: Electronics and Quench Detectionmentioning

confidence: 99%

“…To this end of the HEX the HTS module is connected that is conduction cooled only and leads the current to the CL cold end that is actively cooled with 4.5 K He. Details can be found in [2][3][4]. To test the CLs after production, a dedicated test bed "CuLTKa" (Current Lead Test facility Karlsruhe) is under construction at KIT.…”

Section: Introductionmentioning

confidence: 99%

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Test Arrangement for the W7-X HTS-Current Lead Prototype Testing

Fietz

Drotziger

Fink

et al. 2011

IEEE Trans. Appl. Supercond.

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The Karlsruhe Institute of Technology (KIT) is responsible for the design, construction and testing of the high temperature superconductor (HTS) current leads for the stellarator Wendelstein 7-X (W7-X) which is presently under construction at the Greifswald branch of the Max-Planck-Institute for Plasma Physics. Because the W7-X current leads are mounted with the warm end at the bottom a special test cryostat has been built and is attached to the main cryostat of the TOSKA facility of KIT. Two prototypes of these current leads are tested in this cryostat under W7-X relevant conditions. The test conditions with respect to cryogenic, control, current supply, data acquisition and quench detection of the test setup for the prototype test at TOSKA is described. The performance of the MC plug used to power the HTS current leads is described in detail.

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Test Results of the High Temperature Superconductor Prototype Current Leads for Wendelstein 7-X

Cited by 25 publications

References 8 publications

Current Leads for the Wendelstein 7-X Superconducting Magnet System

Current Leads for the Wendelstein 7-X Superconducting Magnet System

The Superconducting Magnet System of the Stellarator Wendelstein 7-X

Test Arrangement for the W7-X HTS-Current Lead Prototype Testing

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