An experimental investigation of electromagnetic penetration through apertures in a conducting cylinder

Exterior and interior responses obtained with a test cylinder subjected to illumination by the electron magnetic pulse (EMP) simulator for aircraft that is located at the Naval Air Test Center (in Patuxent River, MD) are discussed. Excitation of the inner wire through one or two apertures is examined for configurations in which the orientation of apertures with respect to the ground and the terminations at the ends of the interior wire are varied. After discussing the experiment and presenting test data, comparisons between numerical estimates of surface and interior responses and measured data are made. Results indicate that with aperture coupling to an interior wire, the fundamental exterior resonance induces a prominent interior response at the exterior resonance frequency. Details of the interior responses are found to be quite sensitive to the termination conditions.