Trapped Field Characteristics and Fracture Behavior of REBaCuO Bulk Ring During Pulsed Field Magnetization

We have performed pulsed field magnetization (PFM) for the GdBaCuO ring bulk (60 mm in outer diameter, 36 mm in inner diameter, and 17 mm in thickness) with an aluminum alloy bandage at 65 K. When a magnetic pulsed field over 3 T was applied, a fracture was confirmed in the bulk by the trapped field profile. Using a numerical simulation by a finite-element method, the trapped field and the hoop (σ
_θ
) and radial (σ
_r
) stresses were analyzed. A huge compressive stress concentrated at the inner peripheral edge of the ring bulk mainly by the thermal contraction. The additional compressive stress was applied by the flux-pinning-induced magnetostriction around the maximum field during PFM. The mechanical reinforcement in the inner periphery part of the ring bulk must be considered during PFM using a cylinder.