The Shielding of Electromagnetic Pulses by Use of Magnetic Materials

An experimental verification of previous theoretical work on the diffusion of saturated regions in magnetic materials has been accomplished. The diffusion times for the saturated region in Hipernom® tubes have been measured for various exciting magnetic fields and pulse durations. The calculated and experimentally obtained diffusion times are in excellent agreement. Exciting pulse currents up to several thousand amperes have been impressed on the test samples which varied in thickness from 5 to 18 mils. Saturation diffusion times for a 6 mil tube varied from 6 to 0.3 µ sec. depending on the impressed magnetic field amplitude as predicted by the theory. Prior to punch through of the saturated region, little or no magnetic field leakage was detected in the interior of the test samples.