The world's largest pulsed superconducting coil was successfully tested by charging up to 13 T and 46 kA with a stored energy of 640 MJ. The ITER central solenoid (CS) model coil and CS insert coil were developed and fabricated through an international collaboration, and their cooldown and charging tests were successfully carried out by international test and operation teams. In pulsed charging tests, where the original goal was 0.4 T/s up to 13 T, the CS model coil and the CS insert coil achieved ramp rates to 13 T of 0.6 T/s and 1.2 T/s, respectively. In addition, the CS insert coil was charged and discharged 10 003 times in the 13 T background field of the CS model coil and no degradation of the operational temperature margin directly coming from this cyclic operation was observed. These test results fulfilled all the goals of CS model coil development by confirming the validity of the engineering design and demonstrating that the ITER coils can now be constructed with confidence.

Ahtrud -The conductor Joint is one of the key technologics for superconducting coils. A butt type joint has been successfully developed for Ihe ITER magnets.The 46kA NbSSn conductors arc conncctcd by the diffuslon bonding technique in vacuum, after the reaction of NbJSn. The advantage o f this joint is low losses against pulse fietd, because the compacted part is very small compared with other types of joint. I5 butt joints have alrcady bcon fabricated in the ITER CS Model Coil, According to the test results of the full-size conductor samples, these butt joints will be operated stably in the pulsc operation, because the temperature increase due to ac losses and Joule heating by jolnt resistance is very small and the joint has sufficiently high temperature margin,

Abstrad-Japan Atomic Energy Research Institute(JAERI)has been developing 13-T, 40-kA conductors for the ITER Central Solenoid Scalable Model Coil. The conductors are composed of high performance (NbTi)jSn strands and titanium conduit. In this development work, 15-km length strand fabrication from a 100-kg billet, chrome plating, cabling of 675 or 768 strands, jacketing of titanium conduit, and so on were conducted by two mass production lines. In this paper, several test results are reported such as critical current measurements of full-scale conductors and AC loss measurements of sub-scale conductors.Previously, experimental strands, which had an 800-Nmmz nonapper current density (Jc) at 12 T and a 6-pm effective filament diameter (De@ [2][3][4], were manufactured by a bronze process, using only a 10-kg billet. As the next step in strand technology, strands of 15-km length were fabricated using a 100-kg billet to provide a database for mass production. In practice, full-scale conductors of 20-m length were manufactured in order to evaluate the full-scale conductor, as shown in Fig. 1.In this paper, measurements of critical current (IC) of fullscale conductors and AC losses of sub-scale conductors are evaluated as an estimate of conductor performance.

No abstract

No abstract