Linear superconductive electromagnetic acceleration in a vaccum

[bobbythekid]

Can you calculate the exit velocity of a 25kg ferrous slug from a linear electromagnetic accelerator of a length of about one thousand metres when applied in a vacuum when superconductive electromagnets are used?

 

Bonus question:

 

Can you calculate the level of energy required (joules or volts, your choice)

 

Extra question:

 

Can you calculate the cost of this product? we can assume that there is not coating or anything, just a bare kilometre long linear electromagnetic accelerator. include source if possible.

[swansont]

Without being given any of the technical details, the answer is "no".

[Raider5678]

Can you give me some more information,

Top speed of the slug

Acceleration rate

Power of the electromagnetic accelerator

 

Also, to have enough liquid nitrogen alone would cost a fortune.

About 400 trillion dollars.

Per minute.

Edited June 8, 2016 by Raider5678

[EdEarl]

https://en.wikipedia.org/wiki/Railgun#Mathematical_formula

[swansont]

Also, to have enough liquid nitrogen alone would cost a fortune.

About 400 trillion dollars.

Per minute.

 

 

Oh, baloney. Liquid nitrogen is fairly cheap. The LHC pre-cools their superconductors with liquid nitrogen (9000 metric tonnes) before using the much more expensive liquid helium.

http://www.symmetrymagazine.org/article/december-2014/lhc-filled-with-liquid-helium

 

and the LHC is a much more ambitious project than a railgun, even if the latter is a km long.

[John Cuthber]

Can you calculate the exit velocity of a 25kg ferrous slug from a linear electromagnetic accelerator of a length of about one thousand metres when applied in a vacuum when superconductive electromagnets are used?

 

 

Quite possibly less than it would be if you didn't use superconducting magnets.

At high field strengths things stop superconducting, so by imposing a condition that the magnets are superconducting, you are limiting the field strength.

Since a coil gun doesn't need to power the magnets for a long time, the energy savings you get from superconductors are less important.

 

Also, if I'm allowed to use a non magnetic stainless steel as the "ferrous" slug, then the answer might be "pretty much zero".

 

What question are you trying to answer?

[Raider5678]

Oh, baloney. Liquid nitrogen is fairly cheap. The LHC pre-cools their superconductors with liquid nitrogen (9000 metric tonnes) before using the much more expensive liquid helium.

http://www.symmetrymagazine.org/article/december-2014/lhc-filled-with-liquid-helium

 

and the LHC is a much more ambitious project than a railgun, even if the latter is a km long.

I don't really know a lot about liquid nitrogen, i figured it would take quite a bit of It to cool even a small section... Then again I'm probably wrong.

[imatfaal]

Can you give me some more information,

Top speed of the slug

Acceleration rate

Power of the electromagnetic accelerator

 

Also, to have enough liquid nitrogen alone would cost a fortune.

About 400 trillion dollars.

Per minute.

 

Liquid nitrogen is cheap. In a vacuum the top speed is pretty much unlimited until you start getting relativistic and I do not want to be on the same continent as a 25kg slug travelling at relativistic speeds wrto the earth. But you are right the OP needs to provide far more info or maybe search the net for some of the presently operating rail guns etc (the US Navy has a doozy that was featured here a year or so ago)

 

BTW Railguns - tbomk - are not simple linear accelerators and rely on the slug forming an electrical contact with both rails, the (huge) current flowing in this circuit causes magnetic fields, and with currents flowing in magnetic field you get force

[Enthalpy]

There are varied designs for electromagnetic guns.

 

A common one indeed has just two rails "shorted" (and this is difficult) by the round. The strong current makes itself the induction as it passes in the rails. The main limit is the quality of the moving contact. It's usually graphite since the rest is worse, and it vaporizes, which contributes by the plasma to a contact, but loses power and erodes the rails and the round, destroying the round if exaggerating. Forces on the rails are bad but easier to cope with.

 

One other design switches many coils after an other, preferibly overlapping, to attract a ferromagnetic round.

 

In both cases, I too fear that superconductors are worse than metals because they limit the induction.

 

Coils could also repel the round acting as a short-circuited loop. As far as I know (and I ignore much) this design is less good as a gun. But it's standard at lithotriptors to repel a conductive membrane as a sound transmitter. An inventor wanted to accelerate D-T rounds that way for fusion, and last time I checked it, the design failed because of superconductor limitations.