OT: EMP and Equipment

[David H. Barr]

http://www.globalsecurity.org/military/library/report/1996/apjemp.htm

For more information, scan the 1996 report found here regarding
non-nuclear EMP devices of the coaxial FCG / Vircator type.  Basically
you've got a small chemical explosive which ramps up in series and
either directly affects the source in the 1ghz range or is pumped
through a Vircator to target a range of frequencies.

The two points of entry are "front door" antennas, dishes, etc.; and
"back door" comm cables, electrical lines, etc.  Like previous posters
mentioned, a Faraday cage, fibre network connections, and good design
can contain a significant fraction of the damage.  A good EMP hardened
server design can be seen, as well.

http://www.globalsecurity.org/military/library/report/1996/faraday.gif

-dhbarr.

PS: Ever since that Popular Mechanics article on the subject, I've
been intrigued.  I don't know why.




On 5/4/05, Allison <ajp166 at bellatlantic.net> wrote:
> >
> >Subject: OT: EMP and Equipment
> >   From: Al Hartman <alhartman at yahoo.com>
> 
> >Let's say that tomorrow, and EMP weapon is employed
> >over a major city in this country.
> >
> >Is there anything an average citizen can do to protect
> >their Computers (Classic or otherwise)?
> 
> Yes.
> 
> 
> >Would having them unplugged help?
> 
> Yes.
> 
> 
> >Or must they be shielded in some way?
> 
> It would help.
> 
> The reason for the terse questions is your asking a broad
> question.  Basically EMP is a sudden expansion then contraction
> of a magnetic field. From basic electronics there are two ways
> to generate power using magnets (or their fields) one is to move
> the wire and the other is to move the magnet.
> 
> The amount of energy induced into a wire is dependent on how many
> lines of force you traverse and thats related to how strong the
> magnets field is (also how close).
> 
> We get EMP from two sources, one common.  The nuke version can
> be very strong but if your close enough for EMP then you may be
> too close to worry.  The other common source is lightinging, every
> bolt we see represents a momentary huge current that collapses
> very quckly with the attendent magnetic fields. There are two
> protection methods applied for lightining.  One being electrostatic
> and the other recognizes the electromagnetic.  Protection for the
> latter is simple most of the time.  Disconnect the power cord,
> antennas, and any control lines.  In short remove any "wires" that
> can have an induced field and transfer that voltage inside to the
> sensitive parts.  Ideally for complete protection a iron or steel
> case with no breaks is best protection against near misses.  In
> both cases distance fromthe event is a really good thing as
> magnetic fields are squarelaw IE: at twice the distance it's
> one quarter strength.
> 
> So yes you can protect your hardware, assuming your far enough
> away to survive. You still ahve to worry about high energy
> particles (neutrons, beta and gamma particles) and other
> radiations ( Xrays and infared).
> 
> 
> Allison
> 
>