{'fraction_non_alphanumeric': 0.025906735751295335, 'fraction_numerical': 0.02461139896373057, 'mean_word_length': 4.725925925925926, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Excitation and Magnetic Field Performances of a Prototype REBCO Sextupole Coil at 4.2 K

A prototype REBa2Cu3Oy (REBCO) sextupole coil was designed and fabricated for the chromaticity correction of an asymmetric–energy collider, named SuperKEKB. The REBCO sextupole coil consists of the six two-layer-rectangular coils, which are wound with a 4-mm-wide coated conductor and impregnated with the epoxy resin. The inner bore radius and coil length are 75 mm and 200 mm, respectively. The designed sextupole field gradient is 200 T/m2 at an operating current of 250 A. We conducted a series of the experiments on the REBCO sextupole coil after the fabrication. In this paper, we present the experimental results of the excitation test and magnetic field measurement at 4.2 K.