Swaging was investigated as a fabrication process for high-density Zn-bonded Sm-Fe-N magnets, which mainly consisted of Sm 2 Fe 17 N x , and their magnetic properties were investigated. The demagnetization curves of the annealed specimens with or without swaging suggested that swaging improved the magnetic polarization. The specimen swaged with a reduction ratio (R) of 82%, a high maximum energy product ((BH ) max ) of 67.8 kJ·m ¹3 with a high coercivity (H cJ ) of 1.89 MA·m ¹1 was obtained. Sm-Fe-N particles were pulverized and the dispersion of Zn particles was improved during swaging, the density of specimens increased resulting in the increase in H cJ and (BH ) max .

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Magnetic fluctuation noise due to a pinned layer (Nmag-pin) was measured to improve head-amp SNR by using fabricated heads, and the results were confirmed through micro-magnetic simulations. An experiment revealed that the Nmag-pin decreased as exchange coupling Jk and/or sensor aspect ratio (SH/Twr) increased. These results were consistent with the simulated ones. Reduced Nmag-pin was expected by both increasing Jk and larger SH/Twr. The simulations indicated that the head with Jk ~ 1.3 erg/cm 2 suppressed most Nmag-pin, and demonstrated improved head-amp SNR around 1 dB.

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The design of open-access elliptical cross-section magnet systems has recently come under consideration. Obtaining values for the forces generated within these unusual magnets is important to progress the designs towards feasible instruments. This paper presents a novel and flexible method for the rapid computation of forces within elliptical magnets. The method is demonstrated by the analysis of a clinical magnetic resonance imaging magnet of elliptical cross-section and open design. The analysis reveals the non-symmetric nature of the generated Maxwell forces, which are an important consideration, particularly in the design of superconducting systems.