Building a better particle weapon.

[Simon_Jester]

If you mean direct spallation of neutrons by proton impact, compared to neutron capture that (a) requires much higher particle energy (to overcome the nucleus charge barrier) and (b) has a much lower reaction cross section (due to deflection and the high probability of the protons getting thermalised by electron interactions before they can impact a nucleus). Consider that the particle energy required for direct spallation is similar to the energy required to fuse the two nuclei, and fusing anything but the lightest ions is really hard with current technology (not that fusing even deuterium is easy). This isn't CERN where you can spend as long as you like slowly accelerating small bunches of particles, in a weaponised application power efficiency and beam luminosity are critical. Using heavier beam ions (alpha particles up) means they have a higher inertia-to-charge to overcome the charge barrier, but at sub-cosmic energies they're still going to have a vastly smaller cross-section than a pure neutron beam (that we see in fission reactor meltdowns).

Touché. Most of my knowledge is in the context of research accelerators, and I may not have thought as hard about generalizing it as I should have.

[LaCroix]

Just a curious question - would it be possible to sterilize a ship with relatively 'little' damage by sweeping an particle beam across it, tow it into storage for 'clean up & cool down', patch the hull, slap new electronics in and add it to your fleet? I got the idea of two empires locked in eternal war as they predominantly use that weaponry (in order to capture valuable ships) and thus, ships permanently change hands. (Interstellar trench warfare, basically.)

[biostem]

Just a curious question - would it be possible to sterilize a ship with relatively 'little' damage by sweeping an particle beam across it, tow it into storage for 'clean up & cool down', patch the hull, slap new electronics in and add it to your fleet? I got the idea of two empires locked in eternal war as they predominantly use that weaponry (in order to capture valuable ships) and thus, ships permanently change hands. (Interstellar trench warfare, basically.)

Depending upon what you mean by "sterilize", you could just have a small drone fly through the innards of the ship, emitting UV rays everywhere - they sell UV wands you can use to sterilize counter tops and such, today.

[LaCroix]

Depending upon what you mean by "sterilize", you could just have a small drone fly through the innards of the ship, emitting UV rays everywhere - they sell UV wands you can use to sterilize counter tops and such, today.

'Sterilize', as in 'kill everything alive in it, including/especially the crew'.

[biostem]

Depending upon what you mean by "sterilize", you could just have a small drone fly through the innards of the ship, emitting UV rays everywhere - they sell UV wands you can use to sterilize counter tops and such, today.

'Sterilize', as in 'kill everything alive in it, including/especially the crew'.

Ah, well in that case, it's be tougher - any advanced space vessel will have to include radiation shielding to protect the crew. Overcoming that without breaching the hull would be a chore - perhaps something that breaches the hull or if the radiation shielding is some sort of active system, you could try to interrupt that.

It be interesting if there was a setting where ships fired missiles that attempted to interface w/ an enemy's computer system and hack or interfere with it.

[Sea Skimmer]

Just a curious question - would it be possible to sterilize a ship with relatively 'little' damage by sweeping an particle beam across it, tow it into storage for 'clean up & cool down', patch the hull, slap new electronics in and add it to your fleet? I got the idea of two empires locked in eternal war as they predominantly use that weaponry (in order to capture valuable ships) and thus, ships permanently change hands. (Interstellar trench warfare, basically.)

If the ship was very lightly armored, more or less no real armor, then maybe so with a gamma ray weapon. I'm not sure anything else is going to work without causing structural damage on the impact side, and even gamma rays will do some of that given enough of them.

Of course ere such a tactic viable, by any means, then the enemy would just employ scuttling charges of some form. Like say maybe a small atomic bomb, or even just small conventional explosives in key points that are heavily shielded, or even fused by something directly sensitive to lethal levels of radiation. So after the first one or two times this works, you'd start capturing scrap. You've given the enemy no chance of living or escaping, why would he do otherwise?

Rewiring and replumbing an enemy vessel as complicated as a space going war ship meanwhile would have to be nightmarish anyway, potentially more effort then building a completely new ship. Go see the rebuild of carrier Baku for Indian use which did cost as much as a new ship, then imagine doing the same job with no blueprints.

The ability to 3D print exact replacement electronic parts would help, but then you'd still need the software to make them work as designed. Hope you have some really advanced AI to figure that out for you so it doesn't take a decade for people to write it, ideally one that wont just program the ship to kill you in the process. Even then you still need to map all the systems accurate to even try, or completely replace them. Which goes back to build a new ship issue. Hulls are cheap, systems and engines are not. This is bound to only get worse in space warfare when a shipyard might be built into a giant nickle-iron sort of asteroid that provides near unlimited hull material to start with.

Capturing warships in space is really not a viable idea if the combat is grounded in anything even close to reality. Depending on how hard of sci fi you go for, even bringing damaged hulks back to base might not be viable from lack of available delta-v budget or just the shear amount of time wasted accelerating the enemy hulk up to a useful velocity in the correct direction. Though perhaps you could push the hulk onto a course home, then leave it behind to coast the rest of the way while your own ship goes on ahead. Some engine concepts will give near unlimited delta-v budget, but rather low thrust like say a fission fragment engines so your limitation might be endurance in time governed by supplies rather then fuel.

[Starglider]

Hulls are cheap, systems and engines are not.

Good analysis as usual Skimmer. For sufficiently advanced (i.e. nano) technology, the damage mechanism that makes radiation kill people tends to inherently make it scrap systems as well. In some sci-fi settings hulls can be expensive and worth salvaging because they're made of something other than normal matter, which takes massive time/energy/facilities to make (e.g. 'quantum crystalline' and 'molecularly bonded' armor in Star Wars, 'Silaris plating' in Mass Effect, various bastardisations of 'neutronium' in Star Trek, PTUs in Schlock Mercenary). Exotic materials of this class are not entirely implausible - there are some theoretical models, from ring carbon reinforced SWNT composite, up to some far out femotech concepts - but right now we're not sure any of them can actually be made.

[Simon_Jester]

Capturing warships in space is really not a viable idea if the combat is grounded in anything even close to reality.

The only exception I can think of to this is if you capture them by compelling their surrender when they're still at least semi-functional and broadly repairable.

[Sea Skimmer]

Good analysis as usual Skimmer. For sufficiently advanced (i.e. nano) technology, the damage mechanism that makes radiation kill people tends to inherently make it scrap systems as well. In some sci-fi settings hulls can be expensive and worth salvaging because they're made of something other than normal matter, which takes massive time/energy/facilities to make (e.g. 'quantum crystalline' and 'molecularly bonded' armor in Star Wars, 'Silaris plating' in Mass Effect, various bastardisations of 'neutronium' in Star Trek, PTUs in Schlock Mercenary). Exotic materials of this class are not entirely implausible - there are some theoretical models, from ring carbon reinforced SWNT composite, up to some far out femotech concepts - but right now we're not sure any of them can actually be made.

I certainly use concepts like that in my own fiction, control of the special elements is a strategic advantage, with radically varying operational and tactical meaning, but I also stay the hell away from space war.

Even then, a big issue is even if such super materials can be made, this would not always mean they can be usefully recycled into a material of similar quality, or at much of a cost advantage. Many modern superalloys of steel for example can be recycled into other good steel, but you wont get back that superalloy property without elaborate and time consuming heat treatments. Some need to be resmelted with additions of scrap and alloying materials rather then just cast again to even try. Ceramics and composites can be all over the place on this topic, and presumably even more so in sci fi. I think authors generally tend to go for the melt it back into whatever approach because its straightforward and production processes are kind of not reader friendly fiction, which is fine, but not something one can just assume out of hand.

Course it is plausible that even known metals might end up being so precious that they are worth stripping out of the hulks in mid space. I can imagine some recycling bots being left behind to strip down a space hulk and smelt down the electronics to extract platinum and a few other elements which may always be genuinely rare for example. The bigger the ships get on both sides, the more viable an approach like this becomes as of course this would mean you notice the mass of your robot salvage-smelter barge carried by the fleet's tanker less, and it can gains you more.

This sort of approach could also be useful if the fleet has repair ships, or on board repair facilities with it which can make use of captured material. Turning an enemy hulk into missiles would be potentially very useful on a long campaign, and you'll always need plating for hull repairs which might just be cut right off enemy hulks. Amusing precedent exist for this sort of thing, such as the USN finally fixing its submarine torpedo detonator problems in WW2 at Oahu with firing pins cut from the propeller of a Japanese Zero shot down December 7th! The alloy happened to be just right for the required weight reduction while still sufficiently hardened to fire the charge.

The only exception I can think of to this is if you capture them by compelling their surrender when they're still at least semi-functional and broadly repairable.

That would tend to depend on how well equipped people are for abandoning ship (space suit vs nuclear powered armored life boat), and how likely an enemy, or friendly forces are to recover the escape system. As generally one would expect the crew to attempt to abandon and scuttle rather then surrender a usable hull even if crippled. The last time major warships surrendered at sea was at Tsushima and even then it was a bit unusual, and primarily to save the vast number of wounded littering the decks of the Russian ships whom had no possible hope were they to be sunk. Space is likely to murder the hell out of wounded anyway. Bad bad place to fight a war, kind of on par with fighting on earth if we replaced all the air with nerve gas ahead of time. Except you can also always freeze to death or cook alive. I'm reminded of my Cloudy With a Chance of Mustard Gas concept now.

Anything close to realistic space warfare would be very monotonous and very fatalistic. The crew is more likely to be aged veterans (of service, maybe not war) then young adults, people who may have joined after they had children rather then before, people utterly determined to win, and completely expecting to die trying. They aren't just going to give up to be hauled away to some alien world or remote capsule in space where they may be more medical experiment then even prisoner. Depending of course on if aliens are involved or not. Getting home might not just be unlikely but a near physical impossibility. Its sort of perfect to encourage fighting to the death even if nothing is ever overtly made to be suicidal.

Now you start going softer in the sci fi, FTL above all else, and now we have a lot more dynamics at work.

[Sky Captain]

If you use magnetic fields to accelerate particles couldn't similar system be used to deflect most of the particles away from critical components? There are real proposals to use magnetic fields to protect crew habitats from solar flare particles during long missions so in theory it should work also against particle beam weapons.

[Simon_Jester]

Up to a limit maybe, but at some point that's like asking "if you use chemical energy to accelerate bullets couldn't you use other chemical energy to slow the bullets back down?" Magnetic fields as particle shielding would work better than some weird system for stopping bullets by throwing explosions in their path, but that should convey the idea.

[Esquire]

Isn't that the basic principle behind ERA?

[Simon_Jester]

ERA is not so good against solid impactors though- just because the incoming uranium spear was accelerated by chemical energy does not mean the chemical energy of a detonating ERA brick will stop it from piercing your armor.

ERA is actually more effective against projectiles whose dynamics are a bit more complicated (i.e. shaped charge jets).

I mean, it's not that this is an inherently bad idea or could never work. The point is that in real life, you can seldom rely on being able to stop an attack in the fires of Mount Doom where it was made purely by virtue of relying on the same principle that made the attack possible.

[Sea Skimmer]

Isn't that the basic principle behind ERA?

The basic principle of present day ERA to be clear, is lateral disruption. The ERA disrupts the threat, pushing it at an angle relative to its existing direction of travel, spreading it out and thus depriving it of its desired concentrated punch at a tiny point on the passive armor. It will hardly do anything to alter the impact velocity of the mass involved, be it a long rod or shaped charge jet.

If a projectile hits ERA at a 90 degree angle the ERA is almost completely ineffective, less effective then passive armor would have been in some cases because it cannot significantly disrupt the length of threat. It can blow apart the tip some, but that's it (scale matters though, a 2lb RPG is much more sensitive to tip disruption then say, a 17lb Hellfire warhead). This is why for example the heavy ERA on Russian tank turrets is mounted in large wedges even though these involve far more mass then vertical blocks. That ensures, since the incoming threat is likely to be on a nearly flat trajectory, something like a 45 degree relative angle which works fairly well.

Forms of ERA other then present standards are possible though.

On the original point, magnetic fields can deflect particles and have been proposed by NASA for making shielding systems for a future Mars spacecraft, but generating a strong enough magnetic field to affect a large anti ship weapon would be difficult to say the least and wont work equally well against all types of threats. Earth has one hell of a magnetic field and still gets bombardment by all kinds of stuff for example.

[Sky Captain]

How would electronic systems on missiles and other small craft fare in heavy particle beam combat? It seems that adequate shielding to bring down radiation levels to human tolerable levels would need many meters of armour that would be problematic even on very large ships. Missiles can't have thick and heavy radiation shielding so it seems missile warhead and guidance electronics would get rad killed long before reaching effective attack range.

IIRC during Cold war there was missile defence proposal that involved space based particle beam weapon that would rad kill inkoming ICBM warheads.

[Cykeisme]

If you use magnetic fields to accelerate particles couldn't similar system be used to deflect most of the particles away from critical components? There are real proposals to use magnetic fields to protect crew habitats from solar flare particles during long missions so in theory it should work also against particle beam weapons.

Just speaking from intuition here.. the weapon will be accelerating its particle stream down a long barrel (as mentioned, one hundreds of meters long would be ideal), and all this time it will be in close proximity to the source of the magnetic fields generated along the barrel.

Meanwhile, the target ship won't be able to affect the stream until it's already fairly close to its hull, whereby it won't have sufficient time to apply significant deflection onto the particles before they've impacted.

So unless the target ship has a curved tubular barrel (that functions much the same as the weapon barrel) with one end pointed precisely toward the firing ship, such that it "catches" the beam and deflects it, it doesn't seem likely you can generate a defensive magnetic field that can do much.

Unless, of course, the defensive magnetic field is many orders of magnitude much more intense than the weapons' fields.. in which case we'd probably be dealing with opposing forces with a huge technological disparity.

[Cykeisme]

Whoops, by the last paragraph I meant that if the defensive magnetic field was many orders of magnitude stronger than the offensive weapon's accelerator fields, then it would be able to deflect the incoming particle stream even though it has a shorter distance to act on the particles.

But the fact that the defenders can generate fields so much stronger probably means that they're technologically kicking butt anyway.

[Simon_Jester]

It's not that simple, because what accelerates particles is the application of rapidly-changing magnetic fields- a changing magnetic field, creating an electric field, as per Maxwell's Laws.

While what deflects them is the mere existence of any magnetic field (changing or constant) that points at an angle to their line of flight.

So there's some hope, because the shield isn't simply a mirror image of the gun... but only so much, because you're still dealing with particles that may be very energetic indeed.

[biostem]

I'm no physicist, but if vessel A was firing some sort of electron-cannon at vessel B, and vessel B was able to impart their hull with a very strong negative charge, could they deflect or lessen the impact of vessel A's weapons? Similarly, if protons were used, could a positive charge accomplish the same thing? I suppose, however, that doing so in a manner that wouldn't screw up your own equipment, would be difficult. I've also read some info on this site describing "superconducting panels" that could help disperse the impact of energy weapons - would it be possible to implement something like this, and would it be possible to use energy weapon impacts to essentially fuel retaliatory strikes back at the originating craft?

[Simon_Jester]

Shield against particle beams by charging the hull? The charge density required would probably be high enough to blow apart your own hull from the electrostatic forces involved.

Superconducting materials allowing you to recharge your own batteries? Good question. There might be some way to arrange it but it's outside the technology we can talk about with confidence.

[Cykeisme]

It's not that simple, because what accelerates particles is the application of rapidly-changing magnetic fields- a changing magnetic field, creating an electric field, as per Maxwell's Laws.

While what deflects them is the mere existence of any magnetic field (changing or constant) that points at an angle to their line of flight.

So there's some hope, because the shield isn't simply a mirror image of the gun... but only so much, because you're still dealing with particles that may be very energetic indeed.

I clearly need to do some research on basic physics then :O


Regarding superconducting materials as protection against particle beams (and capturing the energy of the incoming particle stream), I suppose that'll possibly deal with the electrical charge, but would such materials do anything to ward off the momentum transfer and kinetic energy of the stream?

[Borgholio]

Regarding superconducting materials as protection against particle beams (and capturing the energy of the incoming particle stream), I suppose that'll possibly deal with the electrical charge, but would such materials do anything to ward off the momentum transfer and kinetic energy of the stream?

Unlikely. Smashing a superconductor with a hammer will trash it probably easier than if it was made out of ultra-dense materials designed to ward off physical attacks.

[Simon_Jester]

The real problem is that for a "particle beam" as we understand the concept, the individual particles are moving so fast they don't act like a stream of bullets or cannonballs that smash things up. They don't act like an electric current or some kind of imagined "lightning gun." They don't even act like a concentrated beam of light (or infrared or whatever) that heats things up.

They act like a very intense stream of hard radiation. Possibly one intense enough that its heat transfer has noticeable melting/vaporizing effects, but still, hard radiation.

Exposing a superconducting surface to such radiation is going to screw with its material properties. Screw with a superconductor's material properties more than a very little bit and it ceases to be a superconductor.