Magnetic alignment methods for stretched wire systems in the measurement of insertion device magnetic field integrals at HEPS

The stretched wire system was widely employed in the development of insertion devices for HEPS, owing to its capability for rapid, high-precision, and efficient magnetic field integral measurements. However, the alignment accuracy of the wire remains a critical factor influencing the precision of these measurements. Traditional mechanical alignment methods are insufficient for high-precision requirements, as they cannot compensate for the inherent offset between the mechanical and magnetic centers. To address this limitation, this paper proposes two novel magnetic alignment methods based on theoretical analysis and experimental research. The first method was tailored for measuring single magnetic blocks. By evaluating the magnetic field integral with the block positioned in specific orientations, this method effectively eliminated measurement biases caused by angular deviations between the wire and the magnetic block, significantly improving measurement accuracy. The second method was designed for entire insertion devices. It introduced an innovative approach utilizing attached iron slices to generate a new reference signal, thereby reducing measurement biases between the Hall and stretched wire systems and enhancing the reliability of overall performance assessments. These magnetic alignment methods offered an efficient and innovative solution to improve the precision of magnetic field integral measurements at HEPS.