Development of a Novel Iron Core of Fe-Based Nanocrystalline Strip for Scanning Magnet

Fe-based nanocrystalline materials is a typical soft-magnetic material with advantages such as high saturated magnetic flux, high resistivity and low magnetostriction coefficient. By utilizing a specialized winding process, the ultra-thin strip has been successfully applied for use in scanning magnetic cores. For static field, the simulated and tested integral magnetic field uniformity is consistent, and tested effective length is slightly shorter than simulated one. The static magnetic field can meet the needs of scanning magnets. For transient field, the new iron core has less magnetic field delay and distortion compared to silicon steel sheet iron. The simulated maximum magnetic field delay is reduced from 161 Gauss to 16 Gauss. The maximum magnetic field delay of silicon steel sheet iron under test is 87 Gauss, and the corresponding data of the new iron core is almost 0 Gauss. With the weakening of the magnetic field delay, the magnetic field distortion should also be suppressed. With the novel iron core, the magnetic field of the scanning magnet can be improved, thereby reducing the distance from the scanning magnet to the terminal. Rotating gantry is the focus of current research on proton and heavy ion therapy accelerator facilities. This novel iron core can facilitate a decrease in the rotating diameter and weight of the gantry, while enhancing the scanning accuracy. Moreover, the novel iron core can be exploited in scenarios where ferrite cores are “excess capacity”, but traditional silicon steel cores are “insufficient capacity”, such as for certain bump magnets used in synchrotrons.