Re: Fuel, Ramjets, and the Darwin Awards (was Re: in 'defense' of FT missiles... ;-) )

At 07:29 PM 5/7/97 -0300, you wrote:
>Besides, aren't ramjet fields vulnerable to a widely sprayed mass of 
>fissionable particles ?  I thought the ramjet would bring it together
and 
>form a critical mass, destroying the ship.

I'm not sure. My physics studies were 15 years ago and a friend has
borrowed
the only book I still have that might help me here. I wonder if you can
tailor the field to scoop low mass particles only. What you want is
hydrogen, which has a low atomic mass. Fissionables are much higher in
mass,
and you might be able to filter them. 

On the other hand, the suggestions I've seen have the hydrogen scooped
in
the front end into a fusion reactor. It might be possible to control the
field so that you wouldn't achieve critical mass until the particles are
scooped into the reaction chamber, in which case a fission reaction
would
simply be a small belch compared to the fusion energy released. 

I'm not sure about the field's power. My understanding is that while the
field might do some nasty damage to a ship in its wake, it wouldn't suck
a
ship down the magnetic funnel. I guess the question is whether or not
you
can control the amount of mass sucked down the funnel, and if so to what
degree. I'd imagine that this would be a critical problem, or the first
time
you fly through a cometary tail the huge funnel would suck enough mass
into
the front of the ship that it would destroy it in a collision. 

It's time to talk to a friend of mine about this...

Allan Goodall:	agoodall@sympatico.ca 
"You'll want to hear about my new obsession.
 I'm riding high upon a deep depression. 
 I'm only happy when it rains."    - Garbage