For the improvement of the critical current density of a multifilamentary Nb3Sn strand, a high integrity of Nb filaments should be obtained by the optimal cold-drawing process for reducing the cross-section of the filaments. However, as the number of drawing cycles increases, the strain-hardening exponent of the Nb filaments also increases, which consequently hinders the area reduction, and...
The degradation of transport current property by the mechanical strain on the practical Nb3Sn wire is serious problem to apply for the future fusion magnet operated under higher electromagnetic force. Recently, we developed various Zn solid solution ternary Cu-Sn alloy (Cu-Sn-Zn) matrices for the internal matrix strengthened Nb3Sn wires. Zn remained homogeneously into the matrices after the...
In the past much of the emphasis in the development of Nb3Sn superconducting strands has been on improving the non-Cu critical current density (Jc). Different design Nb3Sn strands were manufactured by the bronze route artificially doped with titanium in bronze. The influences of bronze to Nb volume ratio, filament diameter and Ti content were studied.Bronze to Nb volume ratio affected Jc...
Practical Nb3Sn superconductive strands of composite material were utilized for a cable-in-conduit conductor (CICC) for ITER central solenoid (CS) which consist of 576 Nb3Sn strands, 288 Cu strands and a stainless-steel jacket. During the manufacture of CS, heat treatment up to 923 K is applied to the CICC for reaction of Sn and Nb in Nb3Sn strands. the CICC is cooled down to approximately 4 K...
For the high luminosity upgrade of the large hadron collider (LHC) the US accelerator research program (LARP) is developing a magnet designated MQXF and its associated 40 strand Nb3Sn Rutherford cable designated QXF. To suppress interstrand coupling currents generated during field ramp 25 μm thick stainless steel cores may be included in the QXF cables. For the present study cables with cores...
In the ITER magnets consisting of Nb3Sn conductors, the magnets are fabricated through the so-called wind & react (W & R) technique. In the W & R process, the conductors are wound prior to the heat treatment to form the Nb3Sn superconducting strands from the non-superconducting ductile precursor ones. Then the heat-treated windings are encased into the radial plate keeping their winding shape...
The "Facility for Antiproton and Ion Research - FAIR" will be built near the premises of the renowned physical research institute GSI Helmholtzzentrum für Schwerionenforschung GmbH in Darmstadt Germany. The company Luvata has been the sole supplier for low loss Superconducting wires for the SIS100 main magnets. SIS100 is a ring accelerator (heavy ion synchrotron) with a circumference of 1100...
Nb-rod-method Cu-Nb reinforced bronze process Nb3Sn (Cu-Nb/Nb3Sn) wires are applicable to React-and-Wind processed Nb3Sn coils. The Cu-Nb composite material functions as a reinforcing stabilizer during the superconducting magnet operation. Moreover, it suppresses the damage of reacted Nb3Sn filaments due to the applied stress during manufacturing process such as the pre-bending treatment, the...
After mass production for ITER, Western Superconducting Technologies, Co. Ltd. (WST) still takes great efforts at internal-tin (IT) Nb3Sn strand with higher Jc and lower Qh, for next generation of fusion reactors, such as DEMO in Europe and CFETR in China. Three routes, i.e. Cu split, Sn spacers and 37 subelements were carried out to obtain such strand, based on the structure and process of IT...
The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. The experiment makes use of three large superconducting solenoids: the Production Solenoid (PS), the Transport Solenoid (TS), and the Detector Solenoid (DS). The TS is an “S-shaped” solenoid with a warm-bore aperture of half a meter and field between 2.5 and 2.0 T....
A rig was fabricated to test single-strand excitation and current sharing in Nb3Sn Rutherford Cables. Measurements were performed on a 40 centimeters length of 27-strand cored and non-cored cables which were mounted on a U-shaped holder. Samples were reacted and epoxy impregnated using magnet-like protocols. Current was injected into a single strand at varying I/Ic and a heat pulse was used to...
High-performance Nb3Al superconducting wire has wide potential applications in high-field magnets, magnetic confinement fusion, high energy particle accelerator, etc. However, km-grade Nb3Al wires with high-performance are still not available to the large-scale engineering application due some fabrication problems and intrinsic physic-chemistry properties. In this paper, we reported the...
An apparatus is constructed for Nb3Al short wires heat treatment with rapid heating and quenching (RHQ) method. Multifilamentary Nb/Al precursors are fabricated by rod-in-tube (RIT), powder-in-tube (PIT) and jelly-roll (JR) processes. These precursors are RHQ heat treated in the apparatus and then transformation heat treated at 800 °C for 10 h in a vacuum furnace. Transport and magnetization...
