Trapped field and temperature rise on a φ 65 mm GdBaCuO bulk by pulse field magnetization

The trapped field B-T and temperature rise Delta T on a large GdBaCuO superconducting bulk (65 mm in diameter) have been investigated during pulse field magnetization (PFM), and compared with those on GdBaCuO bulk with a diameter of 45 mm. The maximum trapped field at the bulk center B-T( C) on the phi 65 mm bulk is as small as 1.9 T at T-s = 40 K for the single pulse field application of B-ex = 6.7 T, which is smaller than that of the f 45 mm bulk (B-T( C) = 3.2 T). The total trapped flux phi(T) on the phi 65 mm bulk is, however, about twice as large as that on the phi 45 mm bulk. The magnetic fluxes cannot sufficiently intrude into the center of the phi 65 mm bulk at T-s = 40 K for pulse field applications up to 6.7 T, whereas a large number of the magnetic fluxes are trapped at the peripheral region of the bulk. The trapped field characteristics for both bulks with different diameters can be roughly interpreted by a simple critical state model under zero field cooling (ZFC).