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Manufacturing of superconducting Nb3Sn based Cable-in-Conduit Conductor (CICC) for Toroidal Field (TF) coils for the ITER tokamak under the responsibility of the ITER Domestic Agency for the Republic of Korea, ITER Korea, has been in progress since early 2012. Production of sufficient CICC needed to fabricate the first TF coil solely using Korean (KO) conductor has been achieved. Furthermore, low temperature performance verification tests near ITER operating conditions on a second CICC sample, following tests on a sample from the first KO CICC destined for an ITER TF coil, have recently been performed at the EPFL-CRPP SULTAN facility in Villigen, Switzerland. This paper provides an overview on all CICC that is destined for the first ITER TF coil to be fabricated with KO CICC, along with a brief summary of the results of the low temperature performance verification tests on KO CICC samples.

We have developed an apparatus to investigate the effect of transverse stress under axial strain on the critical current of superconducting strands. An internal tin Nb3Sn wire is soldered on a C-shape ring (called Pacman) made of 2% beryllium doped copper alloy and axial strain from -0.7 to 0.7% can be applied. The actual strain on a sample was estimated from a comparison with the critical current measurement results using a Walter spiral probe. Reversible transverse stress effects on the critical current were studied in this work and the transverse pressure was applied up to 40 MPa under ±0.5% axial strain. The critical current was initially increased about 3% as transverse load was applied and then decreased almost linearly under compressive axial strain. Similar behavior is observed under tensile axial strain but the critical current decreases rather sharply at higher load. A unified description based on 3 dimensional deviatoric strain was difficult for the sample studied in this work.

A revised specification of ITER TF conductor was proposed as "Option2" for the baseline design. The cabling pitches of early stages and the void fraction were adjusted in the consequence of previous R&D programs to improve the degradation of performance against cyclic current loadings in the magnetic field. To obtain the characteristics of the developed design, which are related to the effect of the electromagnetic load, the mechanical parameters and the contact resistances between components of cable were investigated employing a specially developed device of cryogenic press in the transverse direction for a short sample of the conductor cable. Through the measurements, the mechanical characteristics against the cyclic loads were discussed, as well as the effect on inter-strand resistances, according to the cable design.

We propose a simple linear precoder for selection-type cooperative multiple-input multiple-output communication systems. After a received symbol vector is detected at destination, the link which has the highest minimum receive substream signal-to-noise-ratio between the source-destination link and the source-relay-destination link is selected as a transmission link. Under the assumption that the full channel state information is available at every node, source and relay precodering scheme, which is suitable for zero-forcing detector, is proposed. Simulation results show that the performance of the proposed relaying technique is comparable to that of the near-optimal linear protocol while offering lower computational complexity.

The ITER tokamak being constructed in southern France will incorporate a central solenoid (CS) coil consisting of 6 modules stacked one on top of the other. Each module will be constructed from round-in-square $\hbox{Nb}_{3}\hbox{Sn}$ based superconducting cable-in-conduit conductor (CICC). Production of CS conductor for the ITER tokamak had been delayed due to discoveries of faster than expected performance degradation. Investigations into mitigating this shortfall have included using internal-tin (IT) route $\hbox{Nb}_{3}\hbox{Sn}$ strand in place of the bronze (BR) route strand that was originally proposed. Prototype ITER CS conductor samples have been produced using IT route $\hbox{Nb}_{3}\hbox{Sn}$ strand in conjunction with cabling optimization, and conductor performance tests show that they satisfy ITER performance requirements. One of the suppliers of IT route ITER $\hbox{Nb}_{3}\hbox{Sn}$ strand, which will be supplying superconducting strand for ITER CS conductor, is Kiswire Advanced Technology Ltd. (KAT) of Daejeon, Korea. The characteristics of their prototype $\hbox{Nb}_{3}\hbox{Sn}$ strand for ITER CS conductor are presented. Furthermore, performance degradation of the CS strand due to possible strand deformations during the cabling process was also investigated. The results show similarities as well as differences with recent results obtained with BR route $\hbox{Nb}_{3}\hbox{Sn}$ strand. However, direct interpretation of the strand deformation versus performance results may not lead to correct predictions of cable performance because of the strand contact interaction mechanism investigated.