Analysis and interpretation of the full set (2000–2002) of TCS tests in conductor 1A of the ITER Central Solenoid Model Coil

Abstract

The full set of T CS measurements performed during 2000-2002 on conductor 1A of the ITER Central Solenoid Model Coil (CSMC) of the International Thermonuclear Experimental Reactor (ITER) is analysed with the extensively validated M&M code. Under the assumptions of uniform strand properties and uniform current distribution among strands, the performance of this ''average'' strand in the cable is deduced from the best fit of the measured voltage-inlet temperature characteristics. Two fitting parameters are chosen: an ad-hoc additional contribution Ôe extra Õ to the longitudinal strain of the average strand in the cable, and the average-strand (or cable ''effective'') index ÔnÕ of the electric field-current density characteristic. It is shown that the average strand in the CSMC performed less well than expected from the strand database--an increasingly negative e extra being needed to reproduce the coil behaviour at increasing transport currents, and that the cable effective n is clearly below the measured n of the strand. It is argued that this average-strand performance reduction in the CSMC is most likely related to mechanical load effects.

Performance of Japanese $\hbox{Nb}_{3}\hbox{Sn}$ Conductors for ITER Toroidal Field Coils

“…The upper and lower axes are the current in conductor and strand, where and the is the number of strands. The n-values are almost the same as that in the TF model coil [7] and much smaller than that in strands [9]. …”

Implications of NbTi Short-Sample Test Results and Analysis for the ITER Poloidal Field Conductor Insert (PFCI)

“…Both the main winding and the bus bar have been simulated, accounting for the heat transfer and heat generation in the IJ (whose resistance is conservatively assumed equal to 10 ). Three different rates: 2 mK/s, 1 mK/s and 0.5 mK/s, are considered for the inlet helium heating, mimicking a slow multi-step (staircase) heating strategy, as applied in the past to other ITER Insert and Model Coils [6]. The helium in the bus bar is kept at 4.5 K. For the critical properties of the NbTi strands, the ITER Design Criteria and the set of parameters suggested in [4] have been adopted.…”

Radiation Field Prediction System Using Solutions of Exterior Steady-State Radiation Problem

“…In the comparison of the performances of the strands and the GJ SULTAN sample, the effect of the Incoloy magnetization has been neglected. Numerical calculations for the CSMC [5] indicate that the contribution of the Incoloy jacket to the magnetic field is between 75 and 150 mT, depending on the position in the cable. For the considered SULTAN fields between 9 and 11 T, the contribution of the Incoloy to the magnetic field can be neglected.…”