Posted on 09/03/2017 9:12:20 PM PDT by bigbob
The EMP Commission was established pursuant to title XIV of the Floyd D. Spence National Defense Authorization Act for Fiscal Year 2001 (as enacted into law by Public Law 106-398; 114 Stat. 1654A-345). Duties of the EMP Commission include assessing:
- the nature and magnitude of potential high-altitude EMP threats to the United States from all potentially hostile states or non-state actors that have or could acquire nuclear weapons and ballistic missiles enabling them to perform a high-altitude EMP attack against the United States within the next 15 years;
- the vulnerability of United States military and especially civilian systems to an EMP attack, giving special attention to vulnerability of the civilian infrastructure as a matter of emergency preparedness; the capability of the United States to repair and recover from damage inflicted on United States military and civilian systems by an EMP attack; and
- the feasibility and cost of hardening select military and civilian systems against EMP attack. The Commission is charged with identifying any steps it believes should be taken by the United States to better protect its military and civilian systems from EMP attack.
Multiple reports and briefings associated with this effort have been produced by the EMP Commission including an Executive Report (PDF, 578KB) and a Critical National Infrastructures Report (PDF, 7MB) describing findings and recommendations.
The EMP Commission was reestablished via the National Defense Authorization Act for Fiscal Year 2006 to continue its efforts to monitor, investigate, make recommendations, and report to Congress on the evolving threat to the United States from electromagnetic pulse attack resulting from the detonation of a nuclear weapon or weapons at high altitude.
Agreed. Compliance testing at an OATS.
I saw one OTAS that tested for EMP. It was in a huge facility (so that you could park a fighter jet, etc. in it and test it immunity).
Commercial electronics is vulnerable but the design has improved in recent years. I have seen the evolution. Lastly, the physical geometries of the electronics have gotten smaller which would mean that it would require higher and higher frequencies to affect its operation. Higher frequencies can be easier to control. So maybe there is an inherent immunity?
Good EMC design (as you probably know) is not a simple thing.
The physical geometries of the electronics does help, but if you connect it to anything conductive (power supply cord) you negate the advantage of a smaller geometry.
The other thing is that as microprocessors evolve, they also have reduced geometry in the semiconductor substrate. This reduced geometry between semiconductor junctions requires less energy to arc across the gap (meaning the EMP has to couple less energy into a processor to disrupt, damage, or destroy it.
Noise is noise. Blasting anything with a broadband noise source like is produced in a nuke (15hz up to 400MHz from one website)) will find its vulnerabilities. Its susceptibilities.
BTW, this is roughly the frequency range for emissions compliance testing. Susceptibility testing is now done but is still limited (or was limited). Good news is that engineers are doing a better job of designing systems.
But at a higher frequency? Smaller wavelength?
Also, the other side — skin effect which can increase the current density?
My experience with higher frequencies is that they tend to not propagate well through an enclosure or system. So by the time the energy hits the circuit in question, it is greatly attenuated. Then again, I could be wrong.
On the other hand, engineers are not designing for susceptibility at higher frequencies. Only enough to pass the regulatory requirements (with some margin). But as a general rule, good “RF design” will offer some immunity.
generally, for EMC purposes, higher frequencies (radiated) penetrate into an enclosure better than lower frequencies.
lower frequencies conduct better than higher frequencies into enclosures.
However, higher frequencies couple into cables of typical dimensions better than lower frequencies.
You’re right. Good RF design comes into play for EMP tolerance.
Also, not all of the electronics in an enclosure are small geometries. Probably only the digital stuff like the processors and chip sets and memory buses but the power circuitry and IO circuitry is probably larger geometries.
Anyway, it would be an interesting study to determine who susceptible our electronics is to broadband emissions.
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