Time-domain calculation of the leakage of SGEMP transients through braided cable shields

The author presents a time-domain technique for calculating the leakage of SGEMP (system-generated electromagnetic pulse) transients through braided cable shields. Detailed numerical results are given to illustrate the effects of spatial and temporal variations in shield current and voltage on the transient that penetrates to the inner conductor of a braided shield cable. Results are presented for various types of SGEMP shield excitations, including electric-field excitation, magnetic-field coupling, and direct drive due to knock-on electrons. The variability of results obtained indicates that it is necessary to consider details of the expected transients when using low-weight braided shield cables for SGEMP protection