[sci.military] Question on magnetic pulse.

reed@cs.washington.edu (Renee Reed) (01/16/91)

From: reed@cs.washington.edu (Renee Reed)


	Please excuse my ignorance.  I was attached to medical. (USAF)
		
	
	I would like to ask what will happen to the electrical, ie. computer
	controlled communication systems in the event that some nation
	does detonate a nuclear device?   I remember some time ago,
	hearing that all one had to do to put the military, industry,
	business, and government out of commission, was detonate a
	nuclear bomb over the atmosphere and that the resulting electrical
	magnetic pulse would destroy all the computer communications.
	Is this a possibility?  If it is, and if some nation does go
	nuclear, then what will the effect be on local military?  Isn't
	just about everything chip driven now? I know much of the 
	equipment is in beefed up containers, but think that is for
	temp and vibration protection.  Any ideas?   I'm thinking
	of the scenario where Israel goes nuclear to defend in the
	event of an attack by Iraq. 


	--Renee

brooksp@hpcc01.corp.hp.com (Peter Brooks) (01/18/91)

From: Peter Brooks <brooksp@hpcc01.corp.hp.com>
Renee Reed asks:


	I would like to ask what will happen to the electrical, ie. computer
	controlled communication systems in the event that some nation
	does detonate a nuclear device?   

I have to dust off my memories on the ElectroMagnetic Pulse (EMP)
effect.  For it to be effective, it has to be a high airburst, so that
lots of radiation triggers secondary electrons in the ionosphere.
Turning that into English, you would have to have a really high airburst,
one that is specifically intended for its EMP effect.  This is a wild
guess, but you would probably have to get a warhead up to 100,000 feet
for an EMP to occur.

I think some of our equipment is shielded from EMP.  In general, the 
higher the technology of the electronics, the more inherently
sensitive it is, and the better the shielding must be.  Tubes are
effectively immune, while VLSI computer chips are the most sensitive.

I would presume that a nuclear strike against Baghdad would be a
relatively low level airburst.  Thus, EMP should not be
a factor.  Is there a real expert on the net?

Pete Brooks

rxtgep@minyos.xx.rmit.OZ.AU (Glen Pill) (01/18/91)

From: rxtgep@minyos.xx.rmit.OZ.AU (Glen Pill)

>From article <1991Jan16.012543.8861@cbnews.att.com>, by reed@cs.washington.edu (Renee Reed):
> 
> 	Please excuse my ignorance.  I was attached to medical. (USAF)
> 		
> 	
> 	I would like to ask what will happen to the electrical, ie. computer
> 	controlled communication systems in the event that some nation
> 	does detonate a nuclear device?   I remember some time ago,
> 	hearing that all one had to do to put the military, industry,
> 	business, and government out of commission, was detonate a
> 	nuclear bomb over the atmosphere and that the resulting electrical
> 	magnetic pulse would destroy all the computer communications.

That used to be the case.  Apparently a lot of research has been conducted on
this subject (for obvious reasons) and all military equipment is now screened
against EMP effects.  Civilian equipment will most likely be the only equipment
to suffer from EMP effects.  Also, from one book I was reading on the subject,
the author said that electronic equipment using valves was less prone to
failure from EMP, which the USSR was researching into.

--
Glen Pill                              ACSNet: rxtgep@minyos.xx.rmit.oz.au
RMIT Computer Centre                   Snail : 124 LaTrobe St, Melb. Oz. 3000.
                                       Phone : +61 3 660 2538

cramer@uunet.UU.NET (Clayton Cramer) (01/19/91)

From: optilink!cramer@uunet.UU.NET (Clayton Cramer)

In article <1991Jan16.012543.8861@cbnews.att.com>, reed@cs.washington.edu (Renee Reed) writes:
> 	I would like to ask what will happen to the electrical, ie. computer
> 	controlled communication systems in the event that some nation
> 	does detonate a nuclear device?   I remember some time ago,
> 	hearing that all one had to do to put the military, industry,
> 	business, and government out of commission, was detonate a
> 	nuclear bomb over the atmosphere and that the resulting electrical
> 	magnetic pulse would destroy all the computer communications.
> 	Is this a possibility?  If it is, and if some nation does go
> 	nuclear, then what will the effect be on local military?  Isn't
> 	just about everything chip driven now? I know much of the 
> 	equipment is in beefed up containers, but think that is for
> 	temp and vibration protection.  Any ideas?   I'm thinking
> 	of the scenario where Israel goes nuclear to defend in the
> 	event of an attack by Iraq. 
> 
> 	--Renee

You have it a little exaggerated.  EMP can cause either permanent
or temporary disability in many electronic devices, depending how
well they are protected.  For example, it is possible to shield
some electronics from EMP by putting a solid copper sheet around the
electronics, and providing grounding.  Disconnecting antennas &
unplugging equipment from anything that provides a large receiving
array for EMP can be protective.  This is also an argument for
using fiber optics in telephone systems (in particular, DSC/Optilink
fiber optics digital loop carriers :-)) since fiber optics doesn't
turn into a giant EMP antenna like copper wire does.

I understand that MOS/FET technology is especially prone to permanent
damage, however.

But remember that you have to be line of sight for EMP damage.
A 100 megaton bomb 100 miles above Kansas City would supposedly
destroy of disable electronics throughout the Midwest -- but 
a nuclear explosion in the Mideast isn't going to wipe out
electronics here.

For those of us who keep significant quantities of small arms
ammunition at home: EMP can set off large quantities of ammunition
if there are no insulators between the cases -- part of why I
no longer keep rifle ammunition stored in stripper clips.
-- 
Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer
Motto for San Francisco's "peace" activists: Think globally, fight locally.
======================================================================
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