Hitachi Cable completes toroidal field dummy cable

On 22 September at the Hitaka worksite in Japan, Hitachi-Cable and its sub-contractor J-Power Systems (JPS) successfully completed the fabrication of a copper dummy cable unit length measuring 784 m for the ITER toroidal field coils. The Japanese Domestic Agency (JA-DA) is the second Domestic Agency among those involved in the toroidal field conductor procurement to demonstrate its ability to fabricate a dummy cable unit length of at least 760 m. In all, Japan is responsible for procuring 23 km of toroidal field conductor through the Japanese Domestic Agency, and Hitachi-Cable has been awarded the first contract for cabling toroidal field conductor in Japan.

The completion of a dummy length is a key achievement, and a necessary step before cabling superconducting wires as part of the cabling procedure qualification. The toroidal field cable consists of more than 1,400 strands arranged in five, multi-twisted stages. The cabling is carried out in five stages on various types of cabling machines, the most impressive being the big planetary machine used to assemble the fifth stage. Takahaki Isono from the Japanese Domestic Agency and Denis Bessette from the ITER Organization attended this critical step at the Hikata worksite on 21—22 September.

The dummy cable was fabricated at a rate of approximately 1 metre per minute; the cabling work started at 5 p.m. on 21 September and ended at 4 a.m. on 22 September. Big cabling machines operate 24 hours a day! The cabling went very smoothly thanks to the preparatory work of Ishibashi-san from Hitachi-Cable and the skilled operators of JPS who managed to complete the unit length without damaging a single strand. After clearing the cabling procedure hold point, the Japanese Domestic Agency can now prepare for the next challenge: the cabling of a 100-metre toroidal field conductor unit length with superconducting wires for qualification.