Speaker
Description
"The development of Nb3Sn high-field conductor has been executed based on a CERN-KEK collaborative agreement.The scope of the development programme of Nb3Sn high-field conductor is to develop, produce, in representative lengths, and characterize Nb3Sn strand with enhanced characteristics. The final goal is to achieve, in representative unit lengths of material, the following development targets on the basis of magnets performance, for the Nb3Sn conductor:
a) A non-copper critical current density at 4.2 K and 16 T (Jc (4.2 K, 16 T)) of at least 1500 A/mm2;
b) A strand diameter of not more than 1 mm;
c) A fraction of stabilizer to superconductor in the strand of about 1;
d) An equivalent diameter of the superconducting Nb3Sn filaments of less than 50 m;
e) A low electrical resistivity of the copper stabilizer of the strand, i.e. a Residual Resistivity Ratio (RRR) of the copper after strand reaction of above 150.
Based on the agreement, KEK started the R&D program in collaboration with Japanese universities; Tohoku University and Tokai University, and Japanese manufacturers; JASTEC and Furukawa electric. Two technologies are chosen as primary candidates, one is the JASTEC distributed Tin (DT) method and the other is Nb tube method by Furukawa. Several R&D wires were already produced and intense characterization of the wires were made by Japanes collaboraters as well as by CERN.
The current status of the program will be reported.
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