AC impedance of a dipole

Hello,

I am at the moment trying to simulate a simple system and I am having a few problems.

I am trying to calculate the self impedance of a dipole located inside a full space of conductivity 0 and permittivity 80.

The dipole is composed of two electrodes represented by two spheres, one is at a potential of 1V and the other is set at the ground. I put the spheres in a rectangle representing the full space.

I would like to plot the self impedance of the dipole as a function of frequency. The self impedance can be expressed as :

Z = (Vt2 - Vt1)/i

Where Vt2 and Vt1 are the potential of the two electrodes and i is the current fed to an electrode. I do a study with in frequency domain : range(1,10,1000).

I then attempt to plot a 1D plot -> Global with frequency in x axis and impedance in y axis.

I do not know what to put in the expression for the Y axis, indeed i would like to plot the formula above but I am unable to find how to express Vt1, Vt2 and i. Is it possible ?

Is there a way to plot directly the self impedance of the dipole with Comsol ?

Thank you very much for your help

Anthony