Responses of a Conducting Cylinder to Pulsed Surface Current Injection

Part of the effort to develop a portable EMP surveillance technique has been dedicated to studies of the responses of a hollow conducting cylinder containing bulkheads and an interior wire (Refs. 1-3). An objective of such studies was to evaluate the surface current injection technique (SCIT) as an EMP surveillance tool using a simple test object with known resonance structure. Both plane-wave illumination and pulsed surface current injection have been employed to induce currents on an inner wire which connects the conducting bulkheads with various terminations. Either one or two deliberate apertures were opened in the skin of the cylinder. Measurements of surface responses and currents on the inner wire were conducted with test techniques and equipment commonly employed in EMP tests of aircraft. In the paper below, measured responses obtained under SCIT excitation are presented and compared with corresponding responses to simulated plane-wave excitation. Computed surface current densities and interior currents obtained with the THREDE finite-difference code are contrasted with empirical SCIT data. Techniques for extending the useable data records are examined as a means of reducing the deterministic error bounds estimated for the experimental data.