A Comparative Study of Experimental and Simulated Trapped Magnetic Field of MgB2 Bulks Prepared by the Magnesium Vapor Transport Process

A prototype MgB2 bulk with a diameter of 20 mm and a thickness of 2 mm was synthesized using the MVT (Magnesium Vapor Transport) method, which can realize dense and high-purity MgB2 bulks by transporting and diffusing pure magnesium vapor into boron pellets. Owing to its superior Jc-B characteristic, the obtained bulk by the MVT method exhibited, compared to similar bulks synthesized by the conventional in-situ method, a comparable trapped magnetic field at only one-tenth the thickness. Using the measured Jc(B) data, the influence of the geometry and the size of the bulk synthesized by the MVT method on the trapped magnetic field was investigated by numerical simulation. The simulation results suggest that a bulk fabricated by the MVT method can efficiently achieve a large trapped magnetic field with a thinner thickness for a fixed diameter than a bulk fabricated by the in-situ method.