Mechanical Characteristics Analysis of Stacked Magnet of Rare Earth Barium Copper Oxide Closed-Loop Superconducting Gourd-Shaped Loop

ObjectivesHigh-field superconducting magnets have great application value in many fields. Due to the immature welding technology, the second-generation high-temperature superconducting magnets cannot achieve persistent current mode operation. A rare earth barium copper oxide (REBCO) closed-loop superconducting gourd-shaped loop stacked magnet can achieve unimpeded closed-loop operation. It has been verified that it has the functions of flux density amplification and flux accumulation, and has the potential to achieve high magnetic field output. Therefore, it is crucial to study whether this magnet can maintain stability under high current and high magnetic field conditions.MethodsA three-dimensional finite element model of this REBCO closed-loop superconducting gourd-shaped loop stacked magnet was established to analyze its electromagnetic response and stress-strain distribution under the field cold excitation method.ResultsThe electromagnetic force per unit volume of the stacked magnet decreases gradually from the inner diameter to the outer diameter of the circular loop, with higher values at both ends and lower values in the middle, it presented a “U” shaped distribution. Additionally, the areas with significant stress are located at the connecting bridge and the junction between the loop and the bridge, making these regions prone to deformation and potential quench risks.ConclusionsThe analysis of the distribution characteristics of stress and strain of the magnet has a reference significance for improving the geometric shape of the gourd-shaped double-hole closed-loop superconducting sheet and the structure of the stacked magnet, and is of great significance to the safe operation of the magnet.