Magnetic acceleration of a ship in space (hyper-particle-acceleration?)

[Fedko]

Magnetic acceleration of a "ship" in space (hyper-particle-acceleration?)

ok...was taking a shower and suddenly I imagined something that I thuoght was pretty neat. Now, I am way into sci fi and such, but imagine for a second that if funding and resources was not a problem, that a magnetic accelerator (similar to the ones used in particle accelerators) was built in space. now...this accelerator would be massive...maybe a few hundred kilometers long for the speeds I'm imagining, but regardless...since this would be built in space the vacuum neccesary for accelerating objects to "unlimited" speeds would be available...I imagine that on the other end a large magnetic "net" would "catch" the vessel in a similar fashion

...but I was wondering what kind of factors I would be dealing with in stating the energy needed to propel an object with magnets (metric ton hunk of steel), what a realistic velocity could be considering that it was a 100-kilometer long accelerator with superconducting magnets, and how effective it could be compared to fuel driven vessels

I have no knowledge of electromagnetics and E=mc^2 doesn't seem to really fit in this kind of equation considering the speed of the vessel

suggestions?

 

[russ_watters]

Welcome to PF.

The quality of the vacuum is not the limiting factor for particle accelerators, so there isn't much benefit to building them in space.

Particle accelerators are already used to propel spacecraft : that's what an ion drive is. http://en.wikipedia.org/wiki/Ion_thruster

 

[Fedko]

I'm not talking about shooting particles out of the backside of a ship for a push...I'm talking about literally using the ship as a "particle" and "accelerating" it across space...like putting the ship in a slingshot

 

[russ_watters]

I'm not talking about shooting particles out of the backside of a ship for a push...I'm talking about literally using the ship as a "particle" and "accelerating" it across space...like putting the ship in a slingshot

Oh, ok. Like a rail gun. That idea has been proposed for launching satellites from earth. It wouldn't work very well in space because the launcher would recoil.

 

[Fedko]

Oh, ok. Like a rail gun. That idea has been proposed for launching satellites from earth. It wouldn't work very well in space because the launcher would recoil.

hmm...true...lol...you would end up firing the accelerator in the opposite direction at half the force intended for the ship...
what if it were mounted to a larger object...like a moon?

 

[mdtzparadise]

The main issue this method would have would be the same all other systems of propulsion have. The amount of energy required to accelerate a unit of mass increases exponentially as velocity increases. It would still require a vast amount of energy to accelerate the craft to useful speeds, i.e. speeds at which the craft could reach neighboring stars in one lifetime. What this idea could do, however, is increase the efficiency in which current craft are accelerated. Current systems of propulsion tend to lose a lot energy in the form of heat. A well-designed magnetic accelerator could maximize the energy efficiency of the acceleration. Which could make it take half the time to get to Mars or something. But considering the cost of building such an accelerator, as well as the obvious problem of where the phenomenal amount of energy required to run the accelerator would come from (think about it--conventional particle accelerators here on Earth require unbelievable amounts of energy to accelerate single atoms), it's not a hugely feasible idea for the purposes of doubling craft velocities.

 

[Fedko]

The main issue this method would have would be the same all other systems of propulsion have. The amount of energy required to accelerate a unit of mass increases exponentially as velocity increases. It would still require a vast amount of energy to accelerate the craft to useful speeds, i.e. speeds at which the craft could reach neighboring stars in one lifetime. What this idea could do, however, is increase the efficiency in which current craft are accelerated. Current systems of propulsion tend to lose a lot energy in the form of heat. A well-designed magnetic accelerator could maximize the energy efficiency of the acceleration. Which could make it take half the time to get to Mars or something. But considering the cost of building such an accelerator, as well as the obvious problem of where the phenomenal amount of energy required to run the accelerator would come from (think about it--conventional particle accelerators here on Earth require unbelievable amounts of energy to accelerate single atoms), it's not a hugely feasible idea for the purposes of doubling craft velocities.

I'm not proposing speeds that would provide interstellar travel, merely speeds that would allow us to travel the solar system in relatively short ammounts of time...a large enough solar plant(whatever that means) could easily provide the energy required if this was built in space...the initial boost would require much less power in space due to the fact that Earth's atmosphere and gravity aren't affecting it, andthe power to accelerate an atom to near light speed compared to the power needed to accelerate a vessel to maybe...idk...100k or 200k kilometers per hour aren't as close as it seems...I think that in this case the limit would become how much acceleration the human body can tolerate(if we can travel this way)I was just wondering what some of the math and principles necessary to calculate the energy need and speeds possible are

 

[Buckleymanor]

Oh, ok. Like a rail gun. That idea has been proposed for launching satellites from earth. It wouldn't work very well in space because the launcher would recoil.

What if two identical rail guns were tied together in space.
They launched satellites or craft of identical mass at the same time in opposite directions.

 

[Bob S]

Hi fedco-
Here is an interesting form of particle accelerator, called a betatron, that uses magnetic fields, actually dB/dt, to accelerate charged particles. There is no requirement to use any other forces than the magnetic field itself to accelerate the particles. Electrons have been accelerated to over 300 million volts using this method.

http://teachers.web.cern.ch/teachers/archiv/HST2001/accelerators/teachers notes/betatron.htm
Bob S