Development of HTS Sextupole Magnet for Accelerator

A prototype high-temperature superconducting （HTS） sextupole magnet for the SuperKEKB interaction region has been designed, fabricated and tested. The magnet consists of two types of sextupole coils, normal and skew coil, wound with a REBCO coated conductor 4 mm in width. The design field gradients of the normal and skew coil are 200 T/m2 and 20 T/m2 at 30 K, respectively. The assembled magnet has an aperture of 128 mm, and a length of 332 mm. After fabrication, the test of the magnet was performed in LN2 and in LHe, and the properties of the magnet including field quality were studied. The design, fabrication and performance of the magnet are presented.