Prototype HTS Sextupole Magnet for SuperKEKB Interaction Region

A prototype high-temperature superconductor (HTS) sextupole magnet for the SuperKEKB Interaction Region was fabricated and tested in order to gain experience in the fabrication of HTS magnets as well as to understand their characteristics. The designed field strength of the sextupole magnet is 200 T/m
²
at 30 K. The coil of the magnet has an inner radius of 75 mm and a length of 200 mm. Furthermore, the magnet consists of six rectangular coils wound with a REBa
₂
Cu
₃
O
_7-x
(REBCO) coated conductor, which is 4 mm wide and was impregnated with epoxy resin. After fabrication, the magnet was tested in LN
₂
and it was confirmed that the magnet had been fabricated with no degradation of the conductor properties. In this paper, we briefly present the design and fabrication of the magnet, and the test results at 77 K including the properties of the magnetic field.