A method of reconstruction of critical current profiles from measurements o
f a hysteretic AC loss is proposed. As an example, we have applied this app
roach to study the degradation in the bulk melt-textured HTS sample with a
resonance oscillations technique developed earlier for granular HTS samples
and now modified to study HTS bulks. The critical current density profile
was determined after the degradation in the thin undersurface layer of abou
t 60 mu m. (C) 1998 Elsevier Science B.V. All rights reserved.