Experimental Test of the Magnetic Field Active Shimming Method for Air-Core HTS Quadruple Magnet

Quadruple magnets are used as superconducting magnets in accelerator systems and to focus the accelerated beam particles. Therefore, studies are being conducted to implement HTS quadruple magnets in hot cell regions that possess high heat loads in accelerator systems. Additionally, studies on air-core HTS quadruple magnet (AHQM), which do not possess an iron yoke, are also being carried out. This magnet is suitable for the use in hot cell regions and generates a higher magnetic field. Further, magnetic field characteristic of the magnet are linear with respect to the operating current. However, the magnetic field of an AHQM can be the sensitively affected by manufacturing and assembly errors because the iron yoke is removed. After the manufacturing of the magnet, magnetic field shimming is used to compensate for magnetic field errors. This paper presents the optimum design and process for the copper wire bunch active shim (CBAS) method. Furthermore, a test model of the CBAS method is constructed based on the design, and the characteristics and applicability of the proposed model are analyzed.