Asymptotic surface field of slot antenna on coated cylindrical conductor

It is shown that the asymptotic field near a conducting cylinder with a dissipative coating and circumferential delta source decreases as z^-n with distance z from the source. When the excitation varies as e^{im phi} with azimuthal angle phi , the relations n= mod m mod (m not=0) and n=2 (m=0) determine the power n.