Monte Carlo Analysis of the EMP Response of a Random-Lay Cable

A numerical model of the time-domain response of a randomly configured, multiconductor bundle excited by a nuclear electromagnetic pulse (EMP) is described. The model represents the cable as a multiconductor, multisegment transmission line; individual conductors in a segment are randomly connected to those of adjacent segments. The segment length is determined by a randomization scale length. Specific calculations for an unshielded, 10-conductor cable excited by an EMP signal are discussed and statistical parameters of the induced cable signals are presented. A heuristic model of the cable response is developed, based on the combined contributions of signals excited in individual segments. Reasonable agreement between the heuristic model and the detailed numerical results is found. The results provide useful scaling relationships for an arbitrary N-conductor, N-segment bundle. The methods developed can be extended and used in interpreting the results of system-level experiments and for system response evaluation.