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We describe herein the characteristics of a \Nb3\Sn cable inserted into a conduit (cable-in-conduit conductor) for the International Thermonuclear Experimental Reactor toroidal field (TF) coil and central solenoid (CS). During insertion, the pulling force almost linearly increases as a function of the length li of cable is inserted. The slope of these curves for the CS cables are approximately 74% that for the TF cable, although the mass per unit length of the CS cable is approximately 63% that of the TF cable. Thus, friction between the CS cable and the conduit is slightly greater than that between the TF cable and the conduit. The number Np of rotations at the cable point for the TF cable increases to 50 almost linearly versus li. For li<150\ \m, Np for the CS cables also increases almost linearly with a slightly greater slope than for the TF cable. However, the slope decreases, and Np becomes constant at 30 for li>600\ \m. During compaction, the number Nt of rotations at the tail of the TF cable, the 613-m-long CS cable, and the 918-m-long CS cable increases almost linearly versus compacted cable length to 23, 36, and 69, respectively. The X-ray transmission imaging of the CS conductor clarifies the distributions of the fifth-stage twist pitch of the cable (lp) over the entire length of the conductor. These results are consistent with a geometric analysis based on Np and Nt. The results for lp peak at the cable point; thus, a sample of the conductor should be taken from the point to investigate how lp elongation affects conductor performance. [ABSTRACT FROM PUBLISHER]

The Japan Atomic Energy Research Institute developed a jacket material called JK2LB (0.03C–22Mn-13Cr-9Ni-1Mo-0.2N-B) for the Central Solenoid (CS) conductor in the International Thermonuclear Experimental Reactor (ITER). To demonstrate production feasibility of CS conductor jacket, trial fabrication of a full size jacket using hot extrusion followed by cold drawing of the JK2LB billets was performed. As a result of dimensional measurement, the ITER dimensional requirement for circle-in-square jacket has been achievable. We achieved the requirement of 0.2 % yield strength >1000 MPa and KIC(J) ≥ 130 MPa√m for solution treated + aged jacket. It has been observed that applied cold work strongly affects the toughness of jacket before and after aging. We estimate that C and N reduction will be required to achieve the required strength and fracture toughness for ITER CS jacket. The fabrication R&D has prepared us for mass production of jacket for the ITER CS conductor procurement. [ABSTRACT FROM AUTHOR]