Fabrication of the First US ITER TF Conductor Sample for Qualification in SULTAN Facility

Abstract

A pair of 3.5 m long ITER TF size straight conductors has been fabricated into a conductor short sample and submitted to the SULTAN facility at CRPP for cold test. The sample used a triplet-based cabling pattern in one leg and a septuplet-based in the other. The legs had different cabling pattern and strand diameters, but the same void fraction. To assure the accuracy in measurement of the conductor current sharing temperature, it is important to have uniform current distribution in the cable, which requires uniformly low interstrand resistivity in the joint. In the present sample, the cable/subcable wraps and the chrome plating on all strands were removed from the cable in the termination, followed by compacting and heat treating the termination in a Glidcop sleeve. To improve current transfer, the sintered termination was further filled with soft solder before it was soldered to the copper profile. To clarify the effectiveness of short sample instrumentation, the sample was equipped with enhanced number of sensors and with sensor mounts penetrating the conductor jacket for the thermometers and voltage taps positioned in the high field zone. This paper presents the experiences in sample fabrication and instrumentation, and outlines the parameters used in the key processes.