Trapped Field Properties of GdBaCuO Bulk Superconductors of Various Diameters Magnetized by Pulsed Fields Using an Identical Split Coil

In this paper, the trapped field properties of GdBaCuO disk bulk superconductors of various diameters during pulsed-field magnetization (PFM) using an identical split coil at 65 K have been investigated both experimentally and numerically. The maximum trapped field, B T max , of the φ43-mm bulk was larger than that of the φ30-mm bulk. However, B T max of the φ65-mm bulk was smaller than that of the φ43-mm bulk and the trapped field profile exhibited a distorted "C-shaped" profile. Using the numerical simulation, these results for the φ65-mm bulk can be explained by an inhomogeneous temperature profile and the larger generated heat, Q, due to the lower cooling power of the refrigerator compared to the generated heat. The important issues to achieve higher and homogeneous trapped fields are discussed when using split-coil PFM for larger bulks.