A novel positioning method for Hall magnetic field measurement of heavy ion accelerator

In the magnetic field measurement of accelerator magnets, the precise positioning of the magnetic field measurement system and the magnet is a basic and very important part. By analyzing the mechanical structure and working principle of Hall magnetic field measurement system, a novel positioning method is proposed in this research for the high-precision and fast positioning of magnet and Hall magnetic field measurement system. By measuring the geometric elements of the magnetic field measurement system and the calibration benchmark of the magnet, the geometric relationship between the magnetic field measurement system and the magnet is established, so as to quickly locate the magnet to the position and attitude required by the magnetic field measurement. The mechanical structure of the Hall probe of the magnetic field measurement system is optimized. Two special ceramic reflectors are installed on the vertical and horizontal axes corresponding to the center of the Hall sensor, and the two ceramic reflectors installed on the Hall probe is monitored with a laser tracker. In this way the Hall sensor can be intuitively positioned at the geometric center of the magnet with an accuracy better than 0.05 mm. In the measurement process, the magnetic field measurement trajectory of Hall sensor in the magnet can also be detected by monitoring the coordinates of ceramic reflector in real time. The practical application in Space Environment Simulation and Research Infrastructure (SESRI) magnet magnetic field measurement show that, compared with the traditional positioning method, the proposed positioning method not only improves the repeatability of Hall magnetic field measurement integral field by nearly 10 times, but also improves the positioning efficiency of magnetic field measurement. These results have verified the practicability and effectiveness of the proposed positioning method.