Electromagnetic Field Distribution and Frequency Response for EMP Excitation of an S-280 EMP Shelter

Abstract

The electromagnetic field response has been calculated for an S-280 shelter with both resistive and inductive door seam impedances in an NEMP environment. Peak field distributions were calculated throughout the shelter showing the greatest amplitude near the seams. The frequency response, calculated at various points throughout the shelter show a clear delineation between high frequency propagating modes and lower frequency evanescent modes. The propagating modes start with the lowest frequency near the fundamental resonance mode of the shelter. The peaks of the shelter resonance spectrum dominate the high frequency range.