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

 Subject: Re: [TML] Two articles of interest
 To: "Ian Wood" <dawnhaven@xtra.co.nz>, "The Traveller Mailing List" <tml@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.