Session B5: Electromagnetic Pulse Phenomena

EMP Threats to US National Security: Congressional Responses

The US Congress is considering how best to respond to concerns that EMP is a real and present danger to US security. The threats come from a variety of areas: solar storms, non-nuclear EMP from man-made machines and devices; and nuclear EMP from a nuclear device exploded above CONUS or other critical areas important to the United States and its allies. Responses have to date included passage in the House of legislation to protect the electrical grid in the United States from such threats and hearings before the Homeland Security Committee. Additional efforts include examining missile defense responses, protection of the maritime domain, and hardening of US military and related civilian infrastructure. The House of Representatives has also examined what Europe, the European Union and NATO, both government and private industry, have done in these areas. Complicating matters are related issues of cyber-security and overall homeland security priorities.   

Nuclear Electromagnetic Pulse Review

Electromagnetic Pulse (EMP) from nuclear detonations have been observed for well over half a century. Beginning in the mid-to-late 1950s, the physics and modeling of EMP has been researched and will continue into the foreseeable future. The EMP environment propagates hundreds of miles from its origins and causes interference for all types of electronic instrumentation. This includes military, municipal and industry based electronic infrastructures such as power generation and distribution, command and control systems, systems used in financial and emergency services, electronic monitoring and communications networks, to mention some key infrastructure elements. Research into EMP has included originating physics, propagation and electromagnetic field coupling analyses and measurement-sensor development. Several methods for calculating EMP induced transient interference (voltage and current induction) will be briefly discussed and protection techniques reviewed. These methods can be mathematically simple or involve challenging boundary value solution techniques. A few illustrative calculations will demonstrate the concern for electronic system operability. Analyses such as the Wunsch-Bell model for electronic upset or damage, and the Singularity Expansion Method (SEM) put forth by Dr. Carl Baum, will facilitate the concern for EMP effects. The SEM determines the voltages and currents induced from transient electromagnetic fields in terms of natural modes of various types of electronic platforms (aerospace vehicles or land-based assets -- fixed or mobile). Full-scale facility and laboratory simulation and response measurement approaches will be discussed. The talk will conclude with a discussion of some present research activities.