Whole body ultra-magnetic field 14 T magnetic resonance imag-ing (MRI) magnet is now under design at Institute of Plasma Physics, Chinese Academy of Sciences, the main coil based on the preliminary designed of Nb3Sn Rutherford cable in Channel Conductor (RICC). Rutherford cable is a core components of the conductor. During the fabrication process of Rutherford cable, the strands were subject...
The brittle intermetallic Nb3Sn superconductor is currently being used to develop high field magnets in the framework of the Hi-Luminosity upgrade of the Large Hadron Collider at CERN. Despite its excellent superconductive properties, Nb3Sn wires suffer from significant critical current Ic reduction due to the transverse load applied during the magnets’ assembly and energization.
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The accelerator magnets for the High Luminosity upgrade of the Large Hadron Collider (HL-LHC) use $\mathrm{Nb_3Sn}$ conductor to achieve in-field performance exceeding Nb-Ti based technologies. To sustain the Lorentz forces during operation, a pre-compression is applied to the conductor during the fabrication of the magnet. This can lead to an irreversible degradation due to the mechanical...
As known, the cold-rolled thin Nb-Ti tapes demonstrates very strong anisotropy of pinning force regarding rolling direction and external magnetic field because of dense anisotropic grain boundary structure. This leads in particular to form of “fish-tail” feature in low-field area of magnetization loops in inclined field due to competition of self-field and small external field in media with...
New generation accelerators, such as future circular collider (FCC), require superconducting dipole magnets with non-copper $J_c$ of 1500 A/mm$^2$ at 16 T, 4.2 K. Nb$_3$Sn is the only proven superconductor with large-scale industrial production. Still, present Nb$_3$Sn wires can not meet the required conditions, and improvement in the fabrication is needed. Kobe Steel Ltd. has developed...
Typical Cable In Conduit (CIC) typed Nb3Sn conductor applied for the fusion magnets are manufactured by twisting multiple Nb3Sn strands based on the current-carrying specification. Jc degradation by the cyclic loading in the CIC conductors was confirmed. This is caused by the Nb3Sn filament breakage by applying the huge electromagnetic force (i.e. transverse compressive load). Therefore, the...
In this work, we summarize the results of an experimental campaign of inductive and transport measurements aimed at the evaluation of the electromechanical performances of a 0.85 mm diameter RRP® wire relevant for the HiLumi LHC project. SEM micrographs have been used to evaluate the sub-element diameter and Cu/non-Cu ratio, whereas the chemical composition across the sub-element sections has...
Nb3Al superconducting wires have high critical current and low strain sensitivity of the superconducting properties. Therefore, many Nb3Al wires were developed for accelerator or fusion magnets. In this study, critical current and mechanical properties of various Nb3Al wires were investigated. Some kinds of rapid heating, quenching and transformation (RHQT) processed Nb3Al wires were prepared....
Hf addition together with Ta to the Nb cores results in significant refinement of the Nb3Sn grain morphology, leading to large enhancement of flux pinning characteristics. That is why it attracts much interest in the field of Nb3Sn wire development. This effect has been confirmed so far for the internal tin Nb3Sn wires. However, this effect should be naturally expected also for the bronze...
Using magnetization techniques to determine the temperature dependence of critical current in Nb3Sn wires is attractive. However, there is a known mismatch in the temperature scaling characterizations when using magnetization data compared to transport data. From a practical stand point, it is the latter that matters, as performance prediction, margin calculations, and other aspects of...
For the High Luminosity upgrade of the Large Hadron Collider (HL-LHC), CERN has procured about 20 tons of high critical current density Jc (>1200 A/mm2 at 15 T, 4.22 K) and high RRR (>150) wire from Bruker-EAS and Bruker-OST (1135 km of the 0.7 mm 108/127 RRP wire; 590 km of the 0.85 mm 192 bundle-barrier PIT wire and; 2180 km of the 0.85 mm 108/127 RRP wire). This conductor has been used for...
In the industry for Nb3Sn conductors at the moment, it is considered that 16 mass% is a limit of the tin content for the bronze process as well as a limit of the critical current density (Jc). Because the mechanical performance of the bronze dramatically changes from ductile to brittle with increasing the thin concentration over 16 mass%. Therefore, the internal tin process using pure tin...
