Preliminary study of a superconducting bulk magnet for the Maglev train

One of the prospective applications of high critical temperature supercondu ctors is a superconducting magnet for the magnetically levitated (Maglev) t rain. Recent development shows that REBaCuO and LRE(light rare-earth)BaCuO superconductors prepared by melt processes have a high critical current den sity at 77 K and high magnetic fields. LRE-Ba-Cu-O bulk superconductors mel t-processed in a reduced oxygen atmosphere, named oxygen-controlled-melt-gr owth (OCMG) process are very promising for high field application as a supe rconducting permanent magnet with liquid nitrogen refrigeration. Compared t o good quality melt-grown REBaCuO bulks, LREBaCuO bulks exhibit larger crit ical current densities in high magnetic fields and much improved irreversib ility field at 77 K, implying that more effective flux pinning can be reali zed in a commercially feasible way. In this study, we discuss the possibili ty of a superconducting bulk magnet for a Maglev train. A preliminary desig n of the bulk magnet and also melt processing for REBaCuO and LREBaCuO bulk superconductors and their characteristic superconducting properties are pr esented.