Search

The ITER Organization (10) and the Institute of Plasma Physics at the Chinese Academy of Sciences (ASIPP) are jointly developing the 68 kA current leads using High Temperature Superconductors for the superconducting Toroidal Field (TF) magnet system of the International Thermonuclear Experimental Reactor, ITER. The proposed design consists of a conventional helium cooled heat exchanger operating between 65 K and 320 K and an HTS module covering the low temperature end using Bi-2223 tapes. The first HTS current lead prototypes will be tested in the EAST tokamak facility at ASIPP. This paper discusses the design of the first, 68 kA, TF HTS lead, which is the main emphasis of this first stage of the ITER current lead development program. [ABSTRACT FROM AUTHOR]

For the superconducting magnet system of the International Thermonuclear Experimental Reactor, ITER, 60 current leads for a total current of more than 2500 kA are needed. To reduce the resultant large refrigerator load at 4.5 K, High Temperature Superconductor current leads (HTS-CL) could be used. Therefore, EFDA CSU Garching had launched a development program for a 70 kA HTS-CL demonstrator. The Forschungszentrum Karlsruhe and CRPP developed and built this CL optimized for 50 K Helium operation. In 2004, the CL was successfully tested in the TOSKA facility at the Forschungszentrum Karlsruhe. The very encouraging results lead to testing this CL with 80 K Helium because ITER provides a large 80 K Helium cooling capacity for the thermal shields. At the end of last year, the test could be successfully performed demonstrating that high current capacity current leads can be stably operated at about 80–85 K. Recently, the CL was retested using liquid nitrogen which would be an interesting alternative option. In this paper, the test results for the 80 K He cooling operation as well as for the operation with LN2 are presented and compared to the results obtained before for nominal conditions. [ABSTRACT FROM AUTHOR]

Numerous manufacturers and different strand processing techniques are involved with the production of the Nb3 Sn strand material required for ITER. The superconducting transport properties of brittle Nb3 Sn layers strongly depend on their strain state. Hence, the thermal compression and the substantial transverse load in combination with the key choice for the cabling pattern of the CICCs, will determine their performance. Knowledge of the influence of axial strain, periodic bending, and contact stress on the critical current (Ic) of the used Nb3 Sn strands is inevitable to gain sufficient confidence in an economic design and a stable operation of ITER. We have measured the Ic and n-value of Nb3 Sn strands from various manufacturers in the TARSIS facility, when subjected to spatial periodic bending and contact stress. The Ic and n-values have been determined for applied axial compressive and tensile strain varying from -0.8% up to +0.5%, between T = 4.2 K and 10 K and B = 6 T to 14 T. The strain sensitivity varies appreciably for different strand types. We present a selection of the results obtained so far. [ABSTRACT FROM AUTHOR]

Assesses the radial plate design of the Toroidal Field superconducting coil winding pack of the International Thermonuclear Experimental Reactor. Design options for the winding pack; Features of the radial plate design; Effective elastic characteristics of the winding pack; Stress analysis.

Evaluates the performance of the coils made of Cable-In-Conduit Nb3Sn conductors for the Central Solenoid of the International Thermonuclear Experimental Reactor. Performance of fast ramp tests; Distribution of the current inside the cable; Measurement of the critical current; Determination of the fastest possible current ramps.

Focuses on the development of an Nb3Sn conductor joint for the Central Solenoid (CS) Model Coil of the International Thermonuclear Experimental Reactor. Configuration of the butt joint for the CS Model Coil; Fabrication of hairpin cable; Joint resistance; Measurement of the quench current in various temperatures and fields.