Temperature stability of magnetic field for periodic permanent-magnet focusing system

Abstract

In this study, finite element analysis based on an Ansoft Maxwell software was used to reveal the temperature stability of a magnet ring and the equivalent structural periodic permanent-magnet (PPM) focusing system. It is found that with the temperature increasing, the decrease rate of magnetic induction peak (B z)max of single magnet ring is greater than that of remanence B r of magnet in the range from room temperature to 200 °C, however, the PPM focusing system do have the same temperature characteristics of permanent-magnet materials. It indicates that the magnetic temperature properties of the PPM system can be effectively controlled by adjusting the temperature properties of the magnets. Moreover, the higher permeability of the magnets indicates the less H cb, giving rise to lower magnetic induction peak \( ( {B_{\text{z}} })^{\prime }_{\hbox{max} }. \) Finally, it should be noted that the magnetic orientation deviation angle θ (<15°) of permanent magnets has little effect on the focusing magnetic field of the PPM system at different temperatures and the temperature stability. The obtained results are beneficial to the design and selection of permanent magnets for PPM focusing system.