E-J characteristics and ac losses in a superconducting Bi(2223) hollow cylinder

E-J characteristics in a hollow cylindrical Bi(2223) bulk sample were measured by an inductive method at various temperatures (50-77 K) and various bias flux densities (0.5-5 T). Observed a.c. losses of the same sample at 50 K and 60 K showed remarkable frequency dependences which are inconsistent with the critical state model. The internal distributions of B, E and J and also the a.c. loss were estimated numerically by solving the Maxwell equations with the measured E-J characteristics. While the calculated internal distributions of B, E and J showed noticeable deviations from those predicted by the critical state model, the numerical analysis of the a.c. losses agreed quantitatively with the observed data in wide ranges of temperature and bias magnetic field. This fact indicates that we can estimate the a.c. loss of the bulk sample from the observed d.c. E-J characteristics. (C) 1997 Elsevier Science Ltd.