From: utzoo!decvax!cca!York@MIT-MULTICS@sri-unix
Newsgroups: net.physics
Title: Re: rail-guns
Article-I.D.: sri-unix.4689
Posted: Tue Dec  7 09:38:55 1982
Received: Wed Dec  8 03:18:43 1982

From:  York at MIT-MULTICS (William M. York)
Rail guns are a popular topic these days.  I'm sure that there are many
available references.  Try any good science or engineering library.
There have even been fairly extensive articles in Popular Science and
the like.

There are several different designs.  The basic idea behind at least one
of them is to take two parallel rails and connect them electrically with
a piece of copper (for example).  You then discharge a large capacitor
bank through this circuit.  The copper connector vaporizes, and the
resulting plasma (still conducting) begins to travel "frictionlessly"
down the rails due to the magnetic field, propelling a projectile in
front of it.  Simultaneously (for pratical purposes) you use an
explosive to bring the "breach" ends of the rails together very rapidly.
This raises the magnetic flux tremendously, increasing the acceleration
dramatically.

I believe that in some tests they have accelerated small lexan cubes up
to escape velocity.  Thinking about the energy of a small cube (of
almost any mass) travelling at 11m/sec will show you why the military is
interested.

I'm sure that there are people on this list who can give you more
detailed information.  Have fun.