In this paper a procedure for magnetic hysteresis measurement in quasi-static regime with a controlled rate of change of the magnetic polarization is proposed. The waveform of the polarization is modulated by means of iterative augmentation using an inverse approach. The setup, the measurement principle and the logical diagram of the procedure algorithm are presented. Experimental results obtained with the new procedure, applied on soft magnetic materials are presented. The measurements made at 0.1 Hz and 1 Hz show a difference of the characteristic values in the range of 5 % to 8 %. The paper demonstrates that, with this new procedure, quicker and more reliable measurements could be obtained.

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Rrecently, great effort has been put into improving the performance of particle accelerator magnets by selecting materials with appropriate magnetic properties. The chemical composition and the manufacturing process of these materials determine their magnetic properties. This paper deals with a comparative analysis of the electric and magnetic properties of a broad range of electrical steels and correlates these properties to their chemical composition, in order to select the optimum grade of steel for a magnetic core. The tested samples are electrical steels with Si content in the interval (0.446-3.310)% and Al content in the interval (0.0029-1.260)%. The magnetic tests have been performed with the Epstein frame in quasi-static conditions and measurements of the electrical resistivity have been obtained according to IEC standards. The major hysteresis cycles are presented for each material and their shape are related to the chemical composition. The electrical steel of grade M 140-35 S is the most appropriate for this application.

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