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

Abstract

The trapped field BT and temperature rise ΔT 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 BT(C) on the ϕ 65 mm bulk is as small as 1.9 T at Ts = 40 K for the single pulse field application of Bex = 6.7 T, which is smaller than that of the ϕ 45 mm bulk (BT(C) = 3.2 T). The total trapped flux ΦT on the ϕ 65 mm bulk is, however, about twice as large as that on the ϕ 45 mm bulk. The magnetic fluxes cannot sufficiently intrude into the center of the ϕ 65 mm bulk at Ts = 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).