Trapped Magnetic Field in Proton Irradiated Melt-Textured Y-Ba-Cu-O Superconductors

ABSTRACTThe trapped magnetic fields in high energy proton irradiated melt-textured Y-Ba-Cu-O (MT-Y123) high temperature superconductors (HTS) materials have been studied. Prototype of mini-magnet, about 1 cm3 which retains about 14, 200 G @ 77 K, has been made with these proton irradiated samples. Quasi-persistent magnetic field near 3 to 5 Tesla in liquid nitrogen is feasible with our current MT-Y123 samples. Two types of motors have been tested successfully by replacing metallic permanent magnet with the trapped field in MT-Y123 samples.The trapped magnetic field mapping technique is used to study the superconducting properties of the MT-Y123 materials. Granular structures in MT-Y123 samples can be observed directly by the field mapping method. A phenomenological current model has been developed to account for the trapped field intensity and profile in HTS samples. The trapped field can be reproduced very well by this model. Remenant magnetic moment trapped by MT-Y123 samples measured by this mapping method and by standard VSM will be discussed. The effect of high energy proton (160–210 MeV) bombardment on the field trapping capability and stability will be discussed.