Comparative Study of Magnetic Characteristics of Air-Core and Iron-Core High-Temperature Superconducting Quadrupole Magnets

Measurement of Magnetic Field Properties of a 3.0 T/m Air-Core HTS Quadrupole Magnet and Optimal Shape Design to Increase the Critical Current Reduced by the Incident Magnetic Field

“…We measured the magnetic field at the measuring points of reference in a radius of 70 mm inside the beam tube, and calculated the magnetic field properties. We confirmed that the fabricated air-core HTS quadrupole magnet meets the required magnetic field quality.However, in our previous comparative studies, we found that the air-core model has a stronger magnetic field applied to the coil, where the superconducting wire is located compared to the iron core model [10]. The air-core HTS quadrupole magnet, which must satisfy the required field characteristics only by the HTS wire, generates a larger magnetic field inside the superconducting coil than the iron-core model.…”

“…However, in our previous comparative studies, we found that the air-core model has a stronger magnetic field applied to the coil, where the superconducting wire is located compared to the iron core model [10]. The air-core HTS quadrupole magnet, which must satisfy the required field characteristics only by the HTS wire, generates a larger magnetic field inside the superconducting coil than the iron-core model.…”

“…Therefore, a new quadrupole magnet has been proposed with two differences [8]: replacing the LTS with the HTS wires, and removing the iron-core. As an initial study to replace the existing quadrupole magnets, the effects of the manufacturing error, and the comparison of the characteristics with the iron core, were performed [9,10]. However, no case has been reported on the construction and operation of quadrupole magnets using HTS wires detached from the iron-core.…”

“…Therefore, in applications using HTS wires, the lowest critical current in all sections is evaluated as the critical current of the entire magnet, because the magnet is continuously winding the HTS tape. Therefore, in general, while predicting the critical current of superconducting magnets, including iron-core quadrupole magnets, only the perpendicular magnetic field is considered [6,7,10]. However, the recently developed 2G HTS tapes have different critical current characteristics than those of conventional 2G HTS tapes, because of the introduction of an artificial pinning center to improve its magnetic field performance [17,18].…”