Re: [FT] How screens work (was Re: UNSC designs)

On Tue, 11 Jan 2000 RWHofrich@aol.com wrote:

> In a message dated 1/10/00 9:21:02 PM Eastern Standard Time, 
> beth.fulton@marine.csiro.au writes:
> 
> >  All of which looks grand and very sensible, but doesn't really
answer my
> >  question about how you think screens may even vaguely work ;)
> 
> Here's my try at how screens work--since beams can be defined as
charged 
> particle beams (I am assuming electron, since that's easier to go
FAST)

speed isn't necessarily good; if they go faster, they suffer more from
magnetic fields (the force on a moving charge in a magnetic field is
proportional to its speed, as well as to its charge and the field
strength), plus electrons are lighter than, say, protons or ions, so
they
are going to get knocked about more than other particles by the same
forces; both of these things make electron beams easier to deflect than
proton/ion beams.

> which 
> is why they can casue widespread system failures, then screens could
be some 
> sort of Faraday Field/Cage or some other electro-magnetic mumbo-jumbo.

afaik, a Faraday cage is a structure built of metal (or some other
conductor), through which radio waves cannot pass (sort of); i'm not
sure
wrapping a ship in a big copper cage is exactly what many people think
of
when they ponder screens! :)

but what i think is being got at here is the idea of some sort of
electromagnetic field around the ship, which disrupts charged particle
beams.

if the beam is electrons, charging the ship negatively should do it; if
it's protons, positively (it may be that the charge you need to be
effective is so big it would make life on the ship hard, though!).

i favour some sort of oscillating (call it 'non-Maxwellian', it sounds
cooler) magnetic field myself. a similar sort of thing is used in (wait
for it) quadrupole magnetic lenses, used to focus ion beams in, amongst
other things, mass spectrometers (you learn some seriously random things
on a biochemistry course, i tell you :( ); it should thus be possible to
build some sort of 'anti-lens' employing similar principles which
disrupts
ion beams moving through its field. i'm not sure how you'd screen the
ship
from the effects, though; you might be able to arrange the generators so
that the field over the ship was zero or weak, and there was only a
strong
field in the area around it.

> So, 
> that means the shape of the field could vary from "along ship
skin/hull (via 
> embedded network)" or "100 meter circle centered on Generator" or
anything in 
> between.

i'll drink to that.

tom