Susceptibility of superconductor disks and rings with and without flux creep

for rings with general hole radius a1 and general creep exponent n. Next the exact formulation for rings in a perpendicular applied field Ha(t) is presented in the form of an equation of motion for the current density in thick rings and disks or the sheet current in thin rings and disks. This method is used to compute general magnetization curves m(Ha) and ac susceptibilities x of rings with and without creep, accounting also for nonconstant Jc(B). Typical current and field (B) profiles are depicted. The initial slope of m(Ha) ~the ideal diamagnetic moment! and the field of full penetration are expressed as functions of the inner and outer ring radii a1 and a. A scaling law is derived which states that for arbitrary creep exponent n the complex nonlinear ac susceptibility x(H0 ,v) depends only on the combination H021 /v of the ac amplitude H0 and the ac frequency v/2p. This scaling law thus connects the known dependencies x5x(v) in the ohmic limit (n51) and x5x(H0) in the Bean limit ( n!‘). @S0163-1829~97!01921-8#