Application of the prebending strain effect on CuNb/Nb3Sn superconducting coils fabricated by a react-and-wind method

Gen Nishijima, Hidetoshi Oguro, Satoshi Awaji, Kazumune Katagiri, Kazutomi Miyoshi, Shin Ichiro Meguro, Kazuo Watanabe

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


We have found that prebending treatment, which is repeated bending load at room temperature, greatly enhances the critical current, upper critical field and critical temperature of practical Nb3Sn superconducting wires. In this paper, we focus on the application of the prebending strain effect to practical superconducting coils fabricated by a react-and-wind method. To demonstrate the prebending strain effect on the react-and-wind coil, we prepared two kinds of CuNb /Nb3Sn superconducting monolayer coils. For one of the coils, the superconducting wire of 1.0 mm diameter was repeatedly bent by using ten fixed pulleys before the winding process, resulting in a prebending strain value of 1.0%. The final winding diameter of both coils was 200 mm and the number of turns was 49. In the compressive stress condition, the critical current of the coil with 1.0% prebending strain was 296 A at 11 T, which was larger than that of the coil with 0% prebending strain. These values were much larger than the critical current of the witness sample. The results indicate that the prebending treatment enhanced the coil critical current. In the case of the hoop stress condition, the coil critical currents were approximately 230 A at 11 T for both coils. The maximum electromagnetic hoop stress was calculated to be 360 MPa. The short sample tensile test results qualitatively explained the critical current deterioration of the coil. Furthermore, the 360 MPa hoop stress did not deteriorate the critical current irreversibly.

Original languageEnglish
Pages (from-to)S261-S265
JournalSuperconductor Science and Technology
Issue number12
Publication statusPublished - 2005 Dec 1

ASJC Scopus subject areas

  • Ceramics and Composites
  • Condensed Matter Physics
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


Dive into the research topics of 'Application of the prebending strain effect on CuNb/Nb<sub>3</sub>Sn superconducting coils fabricated by a react-and-wind method'. Together they form a unique fingerprint.

Cite this