Early quasi-steady electro-magnetic fields about conducting surfaces

Step changes in current through either grounded or ungrounded wires lying o n the surface of a uniformly conducting half-space produce image current so urces within the surface of the conductor. This image current is effectivel y the only source term for initial changes in partial derivative (t) B-z, E -x and E-y. The general steady state electric and magnetic field components resulting from steady currents flowing through either grounded or unground ed wires of finite length lying on the surface of a uniform half- space are derived. Then the operators mapping these steady fields into the early val ues of partial derivative (t) B-z, E-x and E-y on or above the conducting h alf-plane resulting from instantaneously stopping the current flRow through the wires are derived.