Interesting Plasma Weapon Concept

[Zixinus]

Welcome to the forum.

First off, why are the aliens invading/attacking? The reason may define their weaponry very well. Also, can you explain the alien's attitude towards battle in general?

For example, in the case of a research, aliens may be equipped with what I would call "glue-hose". Essentially, a hose that spray very quickly drying, cement-like material that may stop any potentially interesting specimen with minimal harm. A lethal backup weapon may also be useful if the thing fails.

Alternatively, if the aliens want to eliminate a city without regard of damage, they would just throw some rocks from space, ie, orbital bombardment. Very effective and devastating, and surprisingly easy once you are in outer space. In case of your typical magically-propelled UFO, its easy. Intercepting such targets may be a plot-point in the game, although, for smacking incoming asteroids I think an ICBM may do the trick. Or not?

Also, robots can be great shock-troops. No sense in wasting powerfully augmented warriors to battle enemies, when a hoard of mass-produced automatons can weaken potential enemies.

To run it down, sending in warriors on foot, like in X-com, is only worthwhile if you want something from an area. In the case of a city, possible persons like important people or intellectuals, or materials and resources like fuels from an atomic plant. To cause damage in general, is not worth it.

An attitude that you should keep in mind, is that any soldier or experienced warrior would rather choose simple and reliable weapons over complicated ones. That's why plasma weapons are worthless: they are overly complicated thus unreliable, ineffective compared to weapons like lasers or conventional firearms and just plain pointless. Beyond that, the more fire-power one has, the better.

I also recall from a sci-fi book, that if you spray concentrated oxygen towards an oxygen-breather's nose, it will make them sleepy. Or was that carbon-dioxide?

For more hints, I recommend to study this site: http://www.projectrho.com/rocket/index.html

It's mainly focused on futuristic rockets, but stuff like aliens and side-arms.

[brianeyci]

Zixinus, I think the man is well aware of some of the things you're saying. X-Com isn't something he invented, and the motives for the aliens coming to Earth are pretty clear.

The question is Winter if you want a more realistic game, or a better game. The two are not always the same. This is SLAM, so I don't think many people will have much patience for a plasma weapon. If you want a better game maybe try the Games and Computers forum. Or else be prepared to debate the science behind plasma weapons themselves, which I don't think you really want to do. If I were you I would just forget the fluff and make a better game.

If you absolutely have to have a reason for a weapon to be called "plasma weapon" I would say pick something simple like some part of the weapon utilizing plasma, rather than the balls containing plasma. Nobody thinks that Arnold's taking about a 40 watt power output when he's talking about a plasma rifle in Terminator, so you don't have to take plasma weapon literally either.

[The Duchess of Zeon]

Hello, everyone -- first post here. I'm Winter, lead story dev for UFO:AI. Adrian Magnus posted a link to this thread on the UFO:AI forums, and after reading the whole thing, I figured I'd drop in.

I'll begin by admitting that I don't know a hell of a lot about plasma physics. Nor do I have much free time for research, especially for a freebie side project (much as I love the game). When I do get into it, I simply don't have the background to understand most of the reference material that's available. Other times we're forced to play a bit loose with realism due to engine limitations or the quirkiness of a particular 3d model.

Even so, while I may not always achieve it, I do try to ground every bit of material in reality as much as I can. This would be easier if I had some knowledgeable people I could count on to give me some pointers and exchange/critique ideas. So, good posters of this forum, I'd like to invite those of you who think your brains are up to the challenge to join the project and keep us writers on the plausibility track.

We may not be able to satisfy every detail to the exacting specifications of reality, due to flaws both technical and personal, but we try. And I think that's important in this day of cartoon games that throw physics and plausibility out completely because it makes development slightly more difficult.

Anyone who's interested, please post here to let me know.

Regards,
Winter

I would seriously suggest simply looking into particle beam cannon as an alternative; I use them entirely as the main energy weapons of the Taloran Star Empire and they were actually researched starting two years before anyone looked into lasers.

To quoeth from a basic summary of the concept:

"The general idea of particle-beam weaponry is to hit a target object with a stream of accelerated particles moving at near the speed of light and therefore carrying tremendous kinetic energy; the particles transfer their kinetic energy to the atoms in the molecules of the target upon striking, much as a cue ball transfers its energy to the racked balls in billiards, thus exciting the target's atoms and superheating the target object in a short time, leading to explosion either of the surface layer or the interior of the target."

So you have virtually instanteous firing - to - hit times at anything less than interplanetary starship combat ranges (and in such engagements, weapons operating at near the speed of light offer the capability to score some hits--3% hit rates is usually more than enough in heavy ship combat, which could be accomplished with computer course predictors and pattern firing at distances probably out to several million KM.), and you get an extremely rapid explosive decoupling effect in the target from superheating, or else even inside the person, which would be wickedly fatal. It would be like combining the effects of dum-dum and exploding bullets, except more powerful. And range would be limited only by attrition of the beam through the atmosphere, which could give it a pretty copious killing distance.

[Ford Prefect]

Of course Duchess, you'd have to think about whether those particles are charged or not - within an atmosphere, I think you can't use neutral particle beams within an atmosphere (something about mutual repulsion? It's all fuzzy). Though with a charged particle weapon, you could certainly imitate a lightning bolt with it. The ionised 'conduit' of air you'd be using would essentially be a pillar of plasma

And to Winter, I'm not exactly much of a physicist, but I can tell you that if you want a plasma weapon, then you you rely on speed to get it to your target, rather than using some sort of containment. The Hellbores of the Bolos, mentioned earlier by Admiral Valdemar are a good example. Bizarrely, Sergeant Schlock's plasma cannon has a more likely effect - it really is nothing more than a particle beam, just with a different name.

[Winston Blake]

Of course Duchess, you'd have to think about whether those particles are charged or not - within an atmosphere, I think you can't use neutral particle beams within an atmosphere (something about mutual repulsion? It's all fuzzy). Though with a charged particle weapon, you could certainly imitate a lightning bolt with it. The ionised 'conduit' of air you'd be using would essentially be a pillar of plasma.

You can use an NPB in the atmosphere if you want to, but there's no point in bothering with the neutralisation component. As I understand it, a CPB will neutralise itself as it punches through the air, leaving a halo of lower energy ions around it (of the same charge as the beam was initially). In fact, NPBs are based on that effect - stripping off the extra electron from negative ions only requires a small amount of gas at the end.

[Zixinus]

I understand that there is the problem of accuracy and how freakin' huge such a particle accelerator would be?

[metavac]

How about a ball lightning weapon?

[Darth Wong]

How about a ball lightning weapon?

Precisely how would that be a good sci-fi weapon? It wouldn't even work at all in space since it's obviously an atmospheric effect, and it occurs rarely enough that nobody has even filmed a natural occurrence so there is very little research on the subject. This means that any theory of how it works (and upon which you would base the description of a sci-fi weapon) is sketchy at best, and could be totally bogus. And at best, it would only have the same kind of destructive effect as a small lightning strike.

Go with lasers, particle beams, and missiles.

[metavac]

How about a ball lightning weapon?

Precisely how would that be a good sci-fi weapon? It wouldn't even work at all in space since it's obviously an atmospheric effect, and it occurs rarely enough that nobody has even filmed a natural occurrence so there is very little research on the subject. This means that any theory of how it works (and upon which you would base the description of a sci-fi weapon) is sketchy at best, and could be totally bogus. And at best, it would only have the same kind of destructive effect as a small lightning strike.

Go with lasers, particle beams, and missiles.

First, ball lightning research is hardly sketchy. Scientists have proposed numerous analogues that model the phenomena to one degree or another at least one is emerging as a prevailing contender with experimental evidence (a, b,c, d).

Second, the first post referred to a plasma pistol. I don't propose that such a weapon be used in a vacuum. Obviously you need some sort of medium in which an arc can propagate.

[Darth Wong]

First, ball lightning research is hardly sketchy. Scientists have proposed numerous analogues that model the phenomena to one degree or another at least one is emerging as a prevailing contender with experimental evidence (a, b,c, d).

That is the definition of "sketchy": competing models which bear little resemblance to one another, and for whom experimental evidence is only beginning to emerge. One of the greatest mistakes Star Trek tends to make is taking every sketchy idea and building on it.

Second, the first post referred to a plasma pistol. I don't propose that such a weapon be used in a vacuum. Obviously you need some sort of medium in which an arc can propagate.

OK, ask yourself the following questions before proposing any sci-fi technology as a replacement for bullets in infantry combat:

1) Would it be more lethal?
2) Would it travel at more than 1km/s?
3) Would it be easily deflected?

Those questions must be asked even if you make the usual fantastic sci-fi assumption that any complex device can be made arbitrarily small, safe, energetic, and reliable.

[Beowulf]

2) Would it travel at more than 1km/s?

Uh, Mike? Most infantry rifles don't even manage 1km/s. 5.56 NATO just manages 3000 fps, and a plasma pistol would only have to match the performance of a pistol, which is around 1/3 that velocity.

[metavac]

That is the definition of "sketchy": competing models which bear little resemblance to one another, and for whom experimental evidence is only beginning to emerge.

Except in this case we're discussing potentially different phenomena, conveniently tossed under one label and unified by a thin thread involving electrical breakdown in gases. It's entirely conceivable that ball lightning observed in nature consists results from a number of distinct processes.

One of the greatest mistakes Star Trek tends to make is taking every sketchy idea and building on it.

ST's writers didn't just take sketchy ideas, they often lifted terms and invented some gibberish to give them entirely new if not terribly meaningful definitions.

OK, ask yourself the following questions before proposing any sci-fi technology as a replacement for bullets in infantry combat:

1) Would it be more lethal?
2) Would it travel at more than 1km/s?
3) Would it be easily deflected?

Those questions must be asked even if you make the usual fantastic sci-fi assumption that any complex device can be made arbitrarily small, safe, energetic, and reliable.

This I don't know for certain since I don't know how plasmoids are modeled (the ideal gas law doesn't work here). That's why I asked the question.

[Darth Wong]

2) Would it travel at more than 1km/s?

Uh, Mike? Most infantry rifles don't even manage 1km/s. 5.56 NATO just manages 3000 fps, and a plasma pistol would only have to match the performance of a pistol, which is around 1/3 that velocity.

3000 fps is close enough to 3300 fps (1 km/s) that 1 km/s is a reasonable approximation IMO. But yes, you are correct that I was thinking about rifles, not pistols. In any case, I'm assuming that this hypothetical sci-fi weapon should be markedly superior to modern weapons, not just matching them. If it merely matches a modern weapon, one must wonder why they bother with the added complexity.

[Darth Wong]

This I don't know for certain since I don't know how plasmoids are modeled (the ideal gas law doesn't work here). That's why I asked the question.

Well, as long as you're persisting, since ball lightning is has neutral buoyancy in atmosphere (which is why it floats), it would make a terrible weapon regardless of its underlying model. Neutral buoyancy means it is no more dense than atmosphere, which means it can't possibly be hurled at 1 km/s at anyone because aerodynamic drag forces will be huge in relation to its momentum.

[Zixinus]

What of rocket bullets? Surely, since the gyrojet project has been resurrected under Deathwind (http://www.deathwind.com/project.htm), it may hold some interest.

It may be unideal for close ranges, but for long ranges it is more ideal as it contentiously propels itself. I also think that the close-range problem could be solved.

The interesting part is that you could do various things with the bullet, put mini-explosives in the tip, cover it with diamond (artificial diamond production is good enough for that, even if expensive at the moment), make darts, etc.


Also, regarding the idea, say there is a ultra-high temperature superconductor that can be produced enough to be used in bullets. Say, we charge it up as best as we can, shoot it out with some kind of launcher (magnetic or otherwise). Say, we make a circuit that closes when it hits something solid. What would happen? I also understand that superconductors could be quite violent.
Perhaps a large enough bullet could store a few droplets worth of quickly-generated plasma, store it till it hits the target, and make the plasma violently eject wolfram shrapnel?

Just some musings.

[Ariphaos]

What of rocket bullets? Surely, since the gyrojet project has been resurrected under Deathwind (http://www.deathwind.com/project.htm), it may hold some interest.

Well, LOSAT was a bullet-guided projectile, though I don't know if the successor (CKEM) is. I still find that highly amusing...

The interesting part is that you could do various things with the bullet, put mini-explosives in the tip, cover it with diamond (artificial diamond production is good enough for that, even if expensive at the moment), make darts, etc.

We use tungsten carbide tips now, for such purposes.

Also, regarding the idea, say there is a ultra-high temperature superconductor that can be produced enough to be used in bullets. Say, we charge it up as best as we can, shoot it out with some kind of launcher (magnetic or otherwise). Say, we make a circuit that closes when it hits something solid. What would happen? I also understand that superconductors could be quite violent.

This is essentially a flying capacitor. Does not strike me as being particularly viable.

Perhaps a large enough bullet could store a few droplets worth of quickly-generated plasma, store it till it hits the target, and make the plasma violently eject wolfram shrapnel?

HEAT warheads work along similar lines (ejecting a secondary 'projectile') but with far superior results.

[Starglider]

Also, regarding the idea, say there is a ultra-high temperature superconductor that can be produced enough to be used in bullets. Say, we charge it up as best as we can, shoot it out with some kind of launcher (magnetic or otherwise). Say, we make a circuit that closes when it hits something solid. What would happen? I also understand that superconductors could be quite violent.

This is essentially a flying capacitor. Does not strike me as being particularly viable.

Superconducting power storage is already under development and cheap room temperature superconductors could potentially make this application a good idea, probably as a grenade-launcher replacement (the advantages being storing more energy than an explosive and the rounds being inert in storage). We have no idea how to make any sort of room temperature superconductor right now, let alone one cheap enough to be used in this application, but unlike many other magic materials it is relatively plausible. However it would not be a circuit that closes when it hits something; a superconducting storage loop is already a closed circuit (energised by an induction coil in the launcher), the energy stored in it is released when the circuit is broken. It is this simplicity that makes the idea cost effective, though of course you still need a very powerful portable generator to run the weapon.

HEAT warheads work along similar lines (ejecting a secondary 'projectile') but with far superior results.

Large superconductor-based shells could work in exactly the same way but with a higher energy density.

[The Duchess of Zeon]

If you anti-gravity technology already in your story, there is little reason why you can't just use that in a railgun. You could get awesome accelerations out of a rifle, then, without worrying about the recoil sending your soldiers flying a hundred feet. It is not terribly realistic, but if you have one, the other is not less plausible, and if you're aiming for realism it's better to have one fundamentally unrealistic technology rather than two.

[Winston Blake]

Well, LOSAT was a bullet-guided projectile, though I don't know if the successor (CKEM) is. I still find that highly amusing...

What does 'bullet-guided' mean?

This is essentially a flying capacitor. Does not strike me as being particularly viable.

Superconducting power storage is already under development and cheap room temperature superconductors could potentially make this application a good idea, probably as a grenade-launcher replacement (the advantages being storing more energy than an explosive and the rounds being inert in storage).

Can you point me to anything that supports that?

[Sea Skimmer]

Well, LOSAT was a bullet-guided projectile, though I don't know if the successor (CKEM) is. I still find that highly amusing...

Bullet-guided? That one doesn’t make sense.

But in any case, LOSAT used a sort of beamrider command guidance, with a pulsed laser on the firing unit sending course corrections to the missile (rather then the missile semi actively homing in on a spot of laser light). This method was used because it was cheap (in terms of the one use electronics on the missile), and because semi active guidance just wouldn’t have worked through the massive smoke cloud firing the thing made.

As far as I can tell C-KEM is using a really screwy kind of laser command guidance, which does not require a direct line of sight between the laser on the launcher and the laser receiver on the missile. Instead the receivers on the missile are mounted on its sides, rather then the rear, and can detect the guidance laser reflecting off the surrounding atmosphere….. Its an interesting idea but its too early in development to know if its really going to work out. Supposedly this would make the missile much less prone to interference from smoke and dust, or active enemy countermeasures.



If you want a guided bullet then you’ve got two problems. Guidance, and flight control. Probably the only workable flight control method for something you could call a bullet is a method which uses rings of tiny explosive charges. Exploding charges in the rings in a precise sequence can make pretty substantial course changes, and without any great loss in velocity. This technology has been demonstrated in principal with some pretty small projectiles but its still far away from being practical.

For the guidance system a laser beam rider ought to work well enough, its pretty simple technology and its within reason for it to be miniaturized to the point that it could fit in a bullet.

However overall you’ve now got a bullet which costs as much as an anti tank missile, as it is built on a nanotech assembly line, and which has lower mass and inferior aerodynamics compared to a normal projectile. What’s more, most gunfire in combat is only aimed in a general sense towards the enemy, so unless your solider has a very clear target, which he could probably hit with a normal bullet, the guidance system is no advantage at all./

[Ariphaos]

What does 'bullet-guided' mean?

It was my first internship at SGP. Essentially, while the LOSAT projectile was spinning, it would fire off bullets (I think it was something closer to shotgun shells) to make course corrections. This was 1998 so it might have changed since then.

Superconducting power storage is already under development and cheap room temperature superconductors could potentially make this application a good idea, probably as a grenade-launcher replacement (the advantages being storing more energy than an explosive and the rounds being inert in storage).

If you have two superconducting plates storing a net charge on either side of a projectile, there is a physical limit to how much you can feasibly store before they will self-discharge. I don't know offhand how close we are to physical limits in modern capacitors but the problem is not storing energy in the plates themselves. What is needed is some sort of superinsulator.

[Starglider]

(the advantages being storing more energy than an explosive and the rounds being inert in storage).

Can you point me to anything that supports that?

The energy stored in an inductor is half the inductance multiplied by the square of the current. Imagine a coil that fits into an artillery shell, 10cm in diameter and 20cm long, with a nickel-iron core and wire with a 1mm^2 cross section. L = core permeability * turns^2 * cross-section / length, which I make to be approximately 10,000 henries. A low temperature superconductor such as niobium-tin can support current densities of around 200,000 amps/cm^2. Ignoring critical magnetic field issues, that gives an energy storage capacity of 20 gigajoules, equivalent to a little under 5 tons of TNT. Unfortunately the magnetic field strength would be somewhere around 100 teslas, while niobium-tin stops superconducting at a little over 24 teslas. Actual energy storage capacity would be a sixteenth of that, ignoring core saturation issues (which would probably drag it down further), but then I haven't made any effort to optimise the coil geometry (I just picked the easiest to analyse baseline).

Clearly the actual energy storage is critically dependent on the material properties of the semiconductor. Real life high temperature superconductors (that work at liquid nitrogen temperatures) have rather lower critical field and current densities, as well as being fragile enough that I doubt there's any way to make them survive being fired out of a coilgun at millions of g. However if you have a magic material that replicates low temperature superconductor properties at room temperature, while being cheap and robust enough to make shells out of, this could be quite viable.

[Darth Wong]

(the advantages being storing more energy than an explosive and the rounds being inert in storage).

Can you point me to anything that supports that?

The energy stored in an inductor is half the inductance multiplied by the square of the current. Imagine a coil that fits into an artillery shell, 10cm in diameter and 20cm long, with a nickel-iron core and wire with a 1mm^2 cross section. L = core permeability * turns^2 * cross-section / length, which I make to be approximately 10,000 henries. A low temperature superconductor such as niobium-tin can support current densities of around 200,000 amps/cm^2. Ignoring critical magnetic field issues, that gives an energy storage capacity of 20 gigajoules, equivalent to a little under 5 tons of TNT. Unfortunately the magnetic field strength would be somewhere around 100 teslas, while niobium-tin stops superconducting at a little over 24 teslas. Actual energy storage capacity would be a sixteenth of that, ignoring core saturation issues (which would probably drag it down further), but then I haven't made any effort to optimise the coil geometry (I just picked the easiest to analyse baseline).

Clearly the actual energy storage is critically dependent on the material properties of the semiconductor. Real life high temperature superconductors (that work at liquid nitrogen temperatures) have rather lower critical field and current densities, as well as being fragile enough that I doubt there's any way to make them survive being fired out of a coilgun at millions of g. However if you have a magic material that replicates low temperature superconductor properties at room temperature, while being cheap and robust enough to make shells out of, this could be quite viable.

The problem with a straight energy comparison is that we're not talking about nuclear yields, where the sheer quantity is so large that transfer mechanisms become less significant. At smaller yields, the transfer mechanism is very important, and an explosive couples very efficiently to the object it is intended to destroy because of the high-velocity shockwave. An abrupt exothermal electrical energy release would not have the same effect.

[Starglider]

At smaller yields, the transfer mechanism is very important, and an explosive couples very efficiently to the object it is intended to destroy because of the high-velocity shockwave. An abrupt exothermal electrical energy release would not have the same effect.

Isn't dumping heat equivalent to a tonne or so of detonating TNT into an artillery shell going to create an explosion anyway? It'll vaporise the coil, and then you've just got a very hot expanding gas as you'd have when a HE shell goes off. The only obvious difference to a HE shell I can see is that some fraction of the energy is going to be radiated as an electromagnetic pulse (which may cause a little eddy heating in conductive armour materials), but unfortunately I don't know how to calculate that (it will be a minority of the energy though). To make a shaped charge warhead I expect you'd explosively disrupt the superconducting loop with an initiator charge, and design the coil core to make your penetrating jet.

[metavac]

To make a shaped charge warhead I expect you'd explosively disrupt the superconducting loop with an initiator charge, and design the coil core to make your penetrating jet.

That'll just blow the loop into charged fragments with the explosive force of the initiator charge. To dissipate loop power explosively, you need to fault the circuit, either by shorting it or overloading it. The arcs generated will hopefully break down insulating material enough fast enough to do damage.