SGEMP-induced transfer admittance coupling in cable bundles

The coupling of energy to the inner wires of an electrical cable bundle exposed to nuclear X-rays which involves the transfer admittance of the inner bundle shields is analyzed. In this coupling mode, the electric field induced by SGEMP between the outer and inner shields couples to the wires via small apertures in the inner shields. The transfer admittance-coupled response is calculated for a generic cable bundle by utilizing an equivalent circuit model, and the results are compared with the direct injection response. The sensitivity of the response to significant cable parameters is examined, and the limitations of the model are noted. It is found that an insulating tape wrap adjacent to the outer shield, usually present as an aid in fabrication, can reduce the response by about an order of magnitude.