Complex permittivity formulation for induced polarization effect in
transient electromagnetics
Abstract
We have studied the relevance of permittivity as an indicator of the IP
effect in transient electromagnetics. The approach is based on a
mathematical formulation of a dielectric model, where we assume that the
free electrons of the induced current are weakly bound electrons
included in a complex frequency-dependent permittivity. We combine this
dielectric function to Maxwell’s equations in order to obtain a modified
Helmholtz equation whose new term contains the polarization parameters
of the medium. The resultant convolution in Ohm’s Law was solved by the
concept of memory variables transforming the convolution into a set of
time-dependent ODE, where the storage of the full-time series of the
electric field is no longer needed. The final model allows any Cole-Cole
Model (CCM) in the electromagnetic fields through the Debye Function
Expansion (DFE) and makes it possible to incorporate additional
information into the canonical property of conductivity through the
dispersive permittivity.