Transport Properties of CuNb Reinforced &lt;inline-formula&gt; &lt;tex-math notation="TeX"&gt;$\hbox{Nb}_{3}\hbox{Sn}$&lt;/tex-math&gt;&lt;/inline-formula&gt; Rutherford Coils in High Fields

Watanabe

Supercond. Sci. Technol.

et al. 2016

A large-bore 14-T CuNb/Nb3Sn Rutherford coil was developed for a 25 T cryogen-free superconducting magnet. The magnet consisted of a low-temperature superconducting (LTS) magnet of NbTi and Nb3Sn Rutherford coils, and a high-temperature superconducting magnet. The Nb3Sn Rutherford coil was fabricated by the react-and-wind method for the first time. The LTS magnet reached the designed operation current of 854 A without a training quench at a 1 h ramp rate. The central magnetic field generated by the LTS magnet was measured by a Hall sensor to be 14.0 T at 854 A in a 300 mm cold bore.

Section: Introductionmentioning

confidence: 77%

Performance of a 14-T CuNb/Nb₃Sn Rutherford coil with a 300 mm wide cold bore

Watanabe

Supercond. Sci. Technol.

et al. 2016

“…All the Nb 3 Sn solenoid coils were made using a react-and-wind (R&W) method. In addition, we applied pre-bending to the reacted Rutherford Nb 3 Sn cables before winding [13][14][15][16]. The load factor of the L1 coil, which operates under the most severe conditions, is 49%.…”

Section: Lts Coilmentioning

confidence: 99%

First performance test of a 25 T cryogen-free superconducting magnet

Watanabe

Supercond. Sci. Technol.

et al. 2017

152

A 25 T cryogen-free superconducting magnet (25T-CSM) was developed and installed at the High Field Laboratory for Superconducting Materials (HFLSM), IMR, Tohoku University. The 25T-CSM consists of a high-temperature superconducting (HTS) coil and a low-temperature superconducting (LTS) coil. A high-strength CuNb/Nb3Sn Rutherford cable with a reinforcing stabilizer CuNb composite is adopted for the middle LTS section coil. All the coils were impregnated using an epoxy resin for conduction cooling. Initially, a GdBa2Cu3Oy (Gd123) coil was designed as the HTS insert coil, and then a Bi2Sr2Ca2Cu3Oy (Bi2223) coil was also developed. The HTS insert and the LTS (CuNb/Nb3Sn and NbTi) outsert coils are cooled by two 4K GM and two GM/JT cryocoolers, respectively. The LTS coils successfully generated a central magnetic field of 14 T at an operating current of 854 A without any training quench. The Gd123 coil generated 10.15 T at an operating current of 132.6 A in the absence of a background field. Subsequently, the operating current of the Gd123 insert was increased in a step-by-step manner under a background field of 14 T. The Gd123 coil could be operated up to 124.0 A stably, which corresponds to 23.55 T, but quenched at around 124.6 A (23.61 T). The Bi2223 insert coil using a Ni-alloy reinforced Bi2223 tape successfully generated 11.48 T at an operation current of 204.7A in a stand-alone test and 24.57 T in a background field of 14 T. The differences between the calculated and the measured values of the central magnetic fields are about 0.4 T for the Gd123 insert and 0.1 T for the Bi2223 insert around 24 T.

Internal Strain Measurement for a <inline-formula> <tex-math notation="TeX">$\hbox{Nb}_{3}\hbox{Sn}$</tex-math></inline-formula> Rutherford Cable Using Neutron Diffraction

Takahashi

IEEE Trans. Appl. Supercond.

et al. 2015

Self Cite

A Rutherford-type cable is one of candidate conductors for a large-scale or high-field superconducting magnet. It is important to evaluate the internal strain state of strand consisting of a cabling conductor to understand the strain dependence of superconducting properties. Internal lattice strains under a tensile load for Nb-rod-processed Nb 3 Sn Rutherford cable with and without the prebending treatment were measured directly by neutron diffraction at room and low temperatures. Stress-lattice strain curves of Nb 3 Sn were obtained, and it was found that the internal lattice strain is smaller than the strain measured on the cable surface by an extensometer above 100 to 150 MPa. It is important to evaluate not only the strain on the cable surface but also the internal strain of a strand in cabling conductors.Index Terms-Internal strain, Nb 3 Sn, neutron diffraction, Rutherford cable.