A plasma cutter is a common machine shop tool. Supplied with pressurized shop air, it emits a continuous jet of that air containing a good bit of plasma. The creation of said plasma results in this jet being extremely hot - hot enough to cut metal. The velocity of the jet isn’t high enough to cause damage by itself, but it’s fast enough (controlled by the supply air pressure) to blow the now-molten metal out of the way.
The rate at which the cut progresses depends primarily on the power of the plasma cutter, the thickness of the material being cut, and the width of the plasma jet. I’ve used a handheld plasma cutter that plugs into an ordinary 110V outlet (so, no more than ~1500 watts) and can cut through 1/4" steel plate, moving along at a “reasonable” rate. I’ve watched a much more powerful handheld plasma cutter that used a 220V outlet (5000-10,000 watts) and could cut through 1" thick steel at a reasonable rate.
If you want something that can cut through 12" thick steel quickly enough to be considered a weapon rather than a tool, it will take a lot of power. Your Shiva Star exemplifies this: it discharges 2 megajoules from its capacitor bank in 1 microsecond, which works out to 2 terawatts. The problem is that if this energy is used in the form of an ordinary plasma cutter, it won’t cut through the steel that fast; heat transfer just doesn’t transfer energy in that quickly.
In reading that article, they speak of the plasma toroid traveling at a significant fraction (3%) of the speed of light, and damaging the target by blasting it with X-rays that would fry the electronics. That’s far different from the damage that would be caused by a kinetic penetrator fired by a rail gun, the purpose of which would be to cause massive mechanical damage.
That is F=ma. I believe what you are looking for is kinetic energy, which is E=0.5*mv^2 . So it is velocity squared there, showing how much more important velocity is than mass.
Silly question…if these plasma weapons fire at such extreme velocities, then why do the projectiles from plasma weapons in video games (Thinking Fallout) travel so slowly?
Well, mostly because they work under the “what looks cool” principle rather than any attempt at scientific accuracy. It’s not likely that a plasma weapon would turn targets into glowing goo, either.
Although it might be possible to design slow moving plasma weapons, the plasma projectiles held together magnetically; that’s one common portrayal of plasma weapons in fiction.
Keep in mind this is all pretty much hypothetical. And I wouldn’t say no mechancal damage at all; it’s just that from reading about it, it appears that the primary mechanism by which the system was expected to disable incoming missiles was by frying the onboard electronics with radiation. Cite:
I would not expect extensive thermal damage, since the exposure to high-temperature plasma would be extremely brief; the worst you might do is incinerate the paint on the surface of the missile.
Mechanical shock is harder to assess. Yes, the plasma is hauling ass, but it may have very low density, which means it could be significantly dispersed by the time it reaches its target. Whatever momentum it had could potentiall be distributed over a large impact area. Might be a really good thump, might severely deform a missile body. I have my doubts about it cutting a missile in half like a kinetic penetrator.
I wouldn’t. It’s science fiction. You might as well try to explain Dark Helmet’s ability to remotely crush the balls of his senior officers.
My take is they had to appear slower then ‘laser weapons’ as laser being light and all obeys the speed limit, plasma being matter and not light leaves a cushion just incase.
I guess i got my answers.
one more thing. off topic.
are railguns able to achieve relativistic speeds?
assuming material science and recoil dampening tech catch up.
it seems the only way for it to be viable for space weapon and transportation use
Hard to discuss plasma weapons without specifying the technology behind it. My understanding is that plasma is ionized gas, so its mass should be quite low. Therefore, I imagine that kinetic force would be minimal, and real damage would be thermal / electrical.
It’s game balance. Plasma weapons are generally more powerful (being spooky future weapons) so their drawback is that the projectiles move slowly and can be dodged. See the opposite in a lot of Unreal and Quake inspired games: the railgun, which does mediocre damage but can instantly hit across the map.
This is the main problem with plasma weapons. The ball or toroid of plasma will expand immediately after firing; if the target is a safe distance away the plasma will have expanded until it is as weak as a candle flame, and if the target is close enough to be damaged then the person firing the weapon will be in danger too.
That’s why solid projectiles are more useful than plasma weapons - they can remain whole while travelling. It helps if they explode on impact, due to explosive charge or kinetic energy; they then become a sort of plasma weapon at long distance.