On Wed, 4/9/14, xxxxxx@shadowgard.com <xxxxxx@shadowgard.com> wrote:

Subject: Re: [TML] Two articles of interest
To: "Ian Wood" <xxxxxx@xtra.co.nz>, "The Traveller Mailing List" <xxxxxx@travellercentral.com>
Date: Wednesday, April 9, 2014, 3:17 AM

On 8 Apr 2014 at 18:20,
Ian Wood wrote:

> the
OTU description of gauss weapons includes "use of
electromagnetic fields to accelerate a projectile"
> (or words to that effect) which I assume
is different from a rail gun that just uses electrical
charge.
>
> The rail
gun must have huge energy densities in its rails, causing
bits to ablate away as fiery plasma,
>
where as a gauss gun I guess would have a more distributed
energy and hence perhaps a less visible signature.

railguns use (if I recall
correctly) JxB forces. They require a
steady *strong* magnetic field (vertical if the
gun is aimed parallel
to the ground). A
high current flows between the rails (from right to
left in the gun is aime horizontally). The
reaction between the
magnetic field and the
curreent throws the projectile forward.

So there will be a signature from the current
flow in addition to any
stray plasma as the
projectile exits.

"gauss" weapons are apparently linear
accelerators (aka "mass
drivers"). As such they'd use a series
of coils with the ones ahead
of the
projectile attracting it iand the ones behind repelling
it.

This requires *very*
finicky timing or switching. And of high power
levels.

This
generates one *hell* of an EM signature de to transient
fields
and current flows. Be very
distinctive as well.

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I'd just like to add a note;

As I recall, L-5 Society members did some research at MIT way-back-when w/ linear accelerators.

I recall an article in the 'L-5 News' stating that while the 'push-pull' technique was initially used it was abandoned in favor of 'pull' only as this greatly simplified things & didn't really affect performance that much.