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This paper describes a new method for the magnetic force analysis of high [T.sub.c] superconductor based on the flux flow and creep model. The introduction of the artificial conductivity, which is used in the conventional method, is not needed. The CPU time requirement of the calculations is considerably lower than that in the case of the conventional method. Thereby th vibration of a levitated permanent magnet was numerically analyzed by taking into account the flux flow and creep.

The flux line structures in the high-Tc superconductor Bi2+xSr2-xCaCu2O8+x (BSCCO) are explored by using small-angle neutron scattering which was previously used to elucidate the spatial alignment of flux lines in YBa2Cu3O7-y (YBCO). The clear diffraction signal which vanishes on raising temperature at constant field, is evident at low fields and temperatures. The signal is absent at fields over 0.1 T, even at the lowest temperatures, possibly because the pinning of individual pancakes distorts straight flux lines.