STUDY OF ELECTRICAL STEEL MAGNETIC PROPERTIES FOR FAST CYCLING MAGNETS OF SIS100 AND SIS300 RINGS

The operating conditions of yoke steels in superconducting magnets of the SIS100 and SIS300 are at 4.2 K and involve unipolar cycles with high magnetic induction. The results of measurements of different classes of electrical steels, both isotropic and anisotropic, under the operating conditions of superconducting dipoles, are presented. The measurements were carried out on ring samples in a quasistatic mode. Dependence of B on H, as well as values of Hc and hysteresis losses during bipolar and unipolar cycles, were determined from hysteresis loops at different temperatures. The anisotropy of steels was measured at room temperature on strip samples, cut along and perpendicular to the rolling direction. A comparison of results on ring and strip samples was carried out. The results of calculations of hysteresis and eddy current losses in the iron yoke of a fast-cycling dipole for the SIS300 are presented. Recommendations regarding the choice of steel grades for fast cycle superconducting magnets are given.