marco@ncsc.navy.mil (Barbarisi) (10/18/89)
From: marco@ncsc.navy.mil (Barbarisi)
On the practicality of particle beams as weapons...
The only place a particle beam (e.g., a beam of protons or neutrons)
will have in useful range is in a near vacuum - space. On Earth
the air will scatter and absorb even the most
powerful beams within a few meters, rendering them useless as weapons.
Further, the 'most powerful beams' can only be produced by
many kilometers of massive accelerator equipment. In space, the
equipment would probably be more manageable and effective, though it
would present a very large target (assuming there's a way to get the
equipment into space).
For example, Wiedner and Sells give an absorption range for 10 MeV
protons of 1.17 m in air and 0.63 mm in aluminum. That's not very far.
I worked with a 10 MeV Van De Graaf accelerator for a while. We used it
to shoot 1 - 5 MeV proton, electron, and alpha beams at thin film
semiconductor targets. The purpose was to perfect a _Non-Destructive_
technique to analyze the compostion of the films. Our biggest problem
was aligning and evacuating the beam channel. The beam channel was massive
and rested on massive supports. Yet if you bumped into it (or stared at it
too hard) it went out of alignment and you didn't get a beam. Also, even
when the channel was evacuated to 20 millibars, you could still clearly
see the proton beam ionizing residual air in the channel (via the glow
of the plasma). As best I recall, the whole setup was about 15 meters
long and weighed mucho tons.
Except for residual radiation, nothing placed in the path of the beam was
measureably damaged. Of course, we didn't put rice paper in there either.
I don't know how to produce a high power neutron beam,
but I suspect it ain't easy.
Summary of the advantages of particle beam weapons:
1) They make good bomb shelters
Summary of disadvantages:
1) Very short range
2) Very large and very massive
3) Very delicate
4) Very very very expensive
Marco C. Barbarisi
Naval Coastal Systems Center
marco@ncsc.navy.mil
My cat formulates all my opinions for me - she has no affiliation with
the Government, the Navy, or stir-fry cooks.