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Copyright 1999 2000  2001  Web Author: Glen A. Williamson webmaster@williamson-labs.com
View from Kwaj
Description
Army  Doc
Links

Electro Magnetic Pulse

Project Starfish-High Altitude ThermoNuclear Detonations; 
Missiles Launched from Johnston, Island.   -->Map
Map of Islands
 
High Altitude Thermo-Nuclear Shots Blind RADARs and Interrupt Communications.
 .
Seen from Kwajalein, Atoll  1500 mi away.
Still Champion, the Mighty  Vacuum Tube. 
 Nature's  Neon
The Humble Transistor didn't stand a chance.
.
    Anecdotes:
Right after WWII, during one Nevada test, circuit breakers, 90 miles away, were tripped; thus giving early hints of EMP.
In the 1964 presidential election, Johnson ver Goldwater, there was a campaign issue of U.S. preparedness against the U.S.S.R. Nuclear threat. The Goldwater side asserted that we were vulnerable to EMP. The Administration claimed there was no such thing as EMP. At the same time, the IEE's (IEEE) technical journal, Spectrum, just happen to publish an article, written by several Bell Labs engineers, on how to harden telephone communications systems against EMP. 

The article showed how a repeater building could be constructed using interconnected conductors in the building's construction such that they acted as a "squirrel cage rotor" as in an A.C. motor--a shorted turn; this was covered by continuous copper Faraday shielding, allowing no unexposed openings. Additionally, there were buried triple shielded coax conduits coming and going from the building, with four #8 copper cables buried adjacent to the conduits. 
 

In point of fact, the high altitude blast is the most damaging to electronic devices, as well as, communications. The faster the derivative (di-dt) of the PULSE, the more energetic the resultant induced field (wave). 
 

There are two possible mechanisms that can destroy any semiconductor:
1) Excessive current, causing melting of the device junctions.

2) Reverse voltages, e.g., for a device that runs with a positive supply, if a negative voltage is applied, the junction is easily ruptured, thus causing instant failure. This mechanism requires significantly less energy to cause damage.

It is fair to say that both mechanisms are at work in an EMP environment.
 

I don't remember hearing of anything happening on Kwaj as a result of the shots. Of course, all of the technical facilities there were heavily shielded. Knowing that there were artifacts in Hawaii, I am surprised we didn't experience the same...
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   Description:
ElectroMagnetic Pulse (EMP) 
is produced by nuclear explosions at high altitudes, High-altitude EMP, or HEMP.
Table 2-2. EMP waveform summary 
Type
Peak Amplitude
Timeframe
     
  HEMP
50 kV/m
Few nsec to 200 nsec
  Surface-burst    
Source region 
1 MV/m 
Few nsec to 1 microsec
 
10 kV/m 
1 microsec to 0.1 sec
Radiated region
 
1 microsec to 100 microsec
  Air-burst    
 Source region 
Similar to surface-burst
.
 Radiated region
300 V/m at 5 km, typical (highly dependent on HOB)
10 nanosec to 5 microsec
  SGEMP
100 kV/m
  Few nanosec to 100 nanosec
  MHn-EMp
30 V/km
  0.1 sec to 100 sec
..
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The view From Kwaj--
See Photo
Map of Islands
Kwajalein Link
Kwaj Missles Link
It was about 21:00 Kwajalein time, and I was just leaving an outdoor movie. All of a sudden there was a flash--like someone had just taken a picture. I looked around, but there were no cameras. Than I heard several people say that the "Johnston Shot" was scheduled for tonight. 

I looked up in the eastern sky-- toward Johnston, Island about 1500 miles away --and there, high in the sky, was the beginning of a thin Arc of very bright White light. It appeared in the shape of a rainbow, except it didn't span from horizon to horizon. 

The impression was that the light was somehow being shaped by the Earth's curvature, i.e.,  reflecting off the ocean's surface. 

After about ten to fifteen minutes it reached its brightest. 

During this time I walked to the Navy's Ham Shack--KX6BU where a buddy of mine--Bill Campbell, W5UHF had been running phone patches back to the States. He said that while he was talking to a "regular on twenty" [meters], all of a sudden there was a flash, and the band instantly went DEAD! "No signals & no noise." "It was as if the receiver had been turned OFF!" 

By the time I arrived (~20 to 30 minutes), the "band" was starting to return. Except: instead of rapid fading-- QSB, there was rapid "worbling"-- a definite aural frequency shifting." It was as if someone were wiggling the tuning knob (PTO) of the Collins 32 S-1 SSB receiver. I have never--before, nor since-- heard such a sound. I concluded that it had to be Doppler shifting of the ~ 14.300 MHz signals, caused-- I assumed --by the ThermoNuclear (>1 Megaton) Induced  Ionospheric Turbulence
 

Copyright 1999 2000  2001  2002  Web Author: Glen A. Williamson webmaster@williamson-labs.com

Suggestions are Solicited, P l e a s e !

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 LINKS:
U.S. Army  EMP document

fas.org/.../emp

Discussion of EMP by Deputy Director DSWA

Lightning  Protection

Map of Islands

Kwajalein Link

Kwaj Missles Link