STABILITY STUDY OF HIGH-CURRENT SUPERCONDUCTING CABLES FOR ACCELERATOR MAGNETS

L. Shirshovª, I. Bogdanov, S. Kozub, P. Shcherbakov, P. Slabodchikov, L. Tkachenko, V. Zubko

Institute of High Energy Physics, Protvino, Russia

Abstract

One of the main requirements to superconducting magnet is its stability, what can be estimated by means Minimum Quench Energy. MQE of Rutherford-type cables with different resistive coating of composite Cu-matrix NbTi multifilament strands has been measured. The equipment for MQE measurements of short cable samples versus magnetic fields is described. Current through the hairpin sample is created by superconducting transformer; the critical current of the primary winding is 100 A, which allows one to measure MQE of short samples at currents up to 15 kA. Current through the sample is measured with help of Rogowsky coil and integrator. In order to generate the heat disturbance in samples, the miniature heaters are used. The energy, released in heater, is changed step by step consecutively and the threshold energy, which causes quench (i.e. MQE), is found by this way. We measured dependencies of MQE upon the sample currents as well critical currents for the superconducting cables in magnetic fields up to 6.5 T. Experimental study of MQE was performed for 19-strands transposed cables, consisting of 0.85 mm diameter wires with natural oxide, Ni and Cr resistive coatings. A computer code for calculations of MQE in a cable has been created.

ª – corresponding author

Paper 

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