Intense electro-magnetic waves generated by nuclear explosions at high altitudes or generated as intentional electro-magnetic interference using electro-magnetic pulse generators or the like are called EMPs (electro-magnetic pulses). EMPs have a great impact, causing damage to or destruction of electronic equipment and extensively paralyzing society. In today's highly electronics-oriented society, countermeasures against EMPs are an urgent issue. Generally, the countermeasures include shielding the electro-magnetic waves that propagate through space (e.g., blocking with metal, etc.) and absorbing the overvoltage and overcurrent induced in cables by EMPs with protection circuits. However, vents and other openings cannot be blocked because of their function. Mitsubishi Heavy Industries, Ltd. has developed, created, and fabricated a structure that can provide vents with countermeasures against EMPs while minimizing the reduction in their cooling (pressure loss) performance that should be inherent, utilizing detailed simulation, additive manufacturing, and other technologies. Then, we have confirmed that this structure can actually provide both electro-magnetic shielding and pressure loss performance.
