Results of the TF conductor performance qualification samples for the ITER project

Abstract

The performance of the toroidal field (TF) magnet conductors for the ITER machine are qualified by a short full-size sample (4 m) current sharing temperature (Tcs) test in the SULTAN facility at CRPP in Villigen, Switzerland, using the operating current of 68 kA and the design peak field of 11.8 T. Several samples, including at least one from each of the six ITER Domestic Agencies participating in TF conductor fabrication (China, European Union, Japan, Russia, South Korea and the United States), have been qualified by the ITER Organization after achieving Tcs values of 6.0–6.9 K, after 700–1000 electromagnetic cycles. These Tcs values exceed the ITER specification and enabled the industrial production of these long-lead items for the ITER tokamak to begin in each Domestic Agency. Some of these samples did not pass the qualification test. In this paper, we summarize the performance of the qualified samples, analyze the effect of strand performance on conductor performance, and discuss the details of the test results.

Comparisons of internal self-field magnetic flux densities between recent Nb3Sn fusion magnet CICC cable designs

“…In terms of temporal assumptions, the model has been developed to explain the results of the ITER CICC performance tests with pseudo direct current [10]. Though AC performance of the CICC using the cable model could be inferred, such as that ITER CS CICC with STP cable would have larger AC losses than original design cable, comparisons or detailed studies of AC test results have yet to be performed with the model.…”

“…The testing which was performed at the SULTAN facility of the Swiss Plasma Center, located within the Paul Scherrer Institute in Villigen, Switzerland verifies conductor performance under simulated operating conditions within the ITER tokamak [8][9][10]. The ITER CS CICC which has to operate in magnetic fields up to 12.34 T is expected to be energized 60,000 times over the ITER tokamak lifetime.…”

Preliminary Performance Test Results of First CICC From Korea Destined for an ITER TF Magnet

“…The 4 m TF conductor CICC performance test sample was prepared according to standardized procedures agreed to amongst ITER Domestic Agencies (DAs) and the ITER International Organization (IO) [4], [8], [9]. The procedures involve first straightening and cutting the 4 m sample to exactly 3419 mm.…”

“…Like the procedures for sample preparation, the procedures for low temperature performance testing were also defined and agreed to amongst the DAs and the IO [4], [9]. The testing consists of instrumentation checks followed by an AC loss measurement, a background measurement at high field but without conductor current (baseline run) and then initial measurements of the current sharing temperature (T cs ), the critical current (I c ), and n-index.…”

Analysis of Nb3Sn Strand Microstructure After Full-size SULTAN Test of ITER TF Conductor Sample

“…Since Nb 3 Sn is a brittle compound its critical current is very sensitive to strain and stresses that cabled strands are subjected to during the ITER operating. Testing of short straight samples of full-size ITER TF CICC in the SULTAN facility has mostly shown that significant degradation of the current sharing temperature T cs takes place during multiple electromagnetic cycling [1,2]. Among multiple effects that may contribute to the degradation, damage of the strands in form of filamentary cracks is considered as an important factor.…”