[Klaustrophobia]

if it makes you feel better i've got (in 1.5 months anyway) a NUCLEAR engineering degree and don't know a lot of that.  but in my defense we don't really care about anything but neutrons.

[Dragon]

These particles are the realm of quantum physics and are not really important outside of it.
It is likely that other specializations wouldn't care about them.
Neither of them except the neutrino exisits long enough to mean much outside of the atomic nucleus and neutrinos (is that the correct pural form?) are so dinky that it is only possible to detect their presence by checking for missing energy, since they only interact with gravity or weak nuclear force, neither of which can be realiably used in detectors (which also means that they don't deserve anything more than a footnote when talking about most nuclear reactions from a practical POV).

[Klaustrophobia]

according to my astrophysics professor, there actually ARE giant neutrino detectors buried in the earth.  they use them to detect supernovas and whatnot by the countrate jumping from 2/min to 10/min

[General Battuta]

The neutrino detectors are giant buried water tanks. They are awesome.

[Astronomiya]

an EMP (moreso in an atmosphere than in space)

There will be no EMP in space, at least none that matters, because there's no atmospheric electrons to go about blaring synchrotron radiation and bremssthralung all over the damn place.

I don't see neutrinos involved, really.

What Battuta said, and also:  Holy pair production Batman!  Given the extremely high radiation and particle density that will be present in the annihilating matter, you'll get a ton of pair production, and this produces additional opportunities to generate neutrinos and other particles that will carry away energy in forms not conducive to making things dead.  Whether or not this creates enough neutrinos to carry away 50% of the energy, I don't know, but 50% conversion efficiency is certainly plausible, mostly because not all the reaction mass will react, as it's going to be getting blown apart by the already reacting matter/antimatter.

Yes, that would work - for all the ships in close proximity. Would be interesting to do the math on how much gamma radiation would be needed for hull plating to absorb enough energy to start significantly heating up, though. It'll cause radiation sickness long before that happens, I would wager, but don't take my word for it, it's just my intuition.

Not necessarily.  We can assume the armor plating is not very thin, and is probably made of uber-materials up to a meter thick in places (SWAG though this may be).  I would wager that these would be able to absorb almost all of the gamma flux, and most of this would go into shock heating the armor, causing deep cracks, vaporization, and all around failure of the hull.  It most likely would not push it around much.

The problem is, gamma rays spread evenly from a point source, and their effectiveness reduces in inverse square of distance. The even distribution means that at reasonably short distance, they won't be doing much damage at all (at least immediate damage - they may cause radiation sickness, but that doesn't immediately put a warship down like compromised hull structure will.

If you instead convert most of the energy from the reaction into kinetic energy (assuming you can do this) and send shrapnel from the blast site, you get a much more "coarse" distribution of possible damage - but at the same time, the damage delivery is more efficient. The probability of getting hit by pieces of shrapnel will decrease in the inverse square of distance, but individual pieces of shrapnel don't lose their initial kinetic energy, which means the individual pieces of shrapnel retain their effectiveness regardless if distance, unlike a free gamma burst.

You can't do this.  Because the gamma rays will have essentially random momenta and energies (with several peaks around the annihilation energies of the various particles), the absorption of a whole lot of them will not be very effective at propelling something in the direction you want it to go without converting most of the kinetic energy the gamma rays had into thermal motion.  This has the side effect of vaporizing anything you might want to encase the bomb with (find me a material that can withstand millions of Kelvins, and we'll talk).  This also has the side effect of rendering the rest of your post moot, though your math looks right, even if you did use way too many sig figs.

The best bet is to detonate the bomb as close as possible to the hull of the enemy ship, to compromise its hull through extreme shock heating.  We see this in game as well, to a more ridiculous degree, where a near miss does jack squat, while a direct hit can be some major hurt.

The neutrino detectors are giant buried water tanks. They are awesome.

The first one was a big-ass tank of bleach down a deep mine.

[General Battuta]

an EMP (moreso in an atmosphere than in space)

There will be no EMP in space, at least none that matters, because there's no atmospheric electrons to go about blaring synchrotron radiation and bremssthralung all over the damn place.

Not so! This is a common thing to say but not striiiiictly true. In atmosphere the mighty EMP is produced by pumped-up air molecules relaxing and letting out photons. Even in vacuum, however, the explosion itself will release light, which is by definition an electromagnetic pulse. I doubt it'll have any effect on hardened military equipment whatsoever, though.

(Even a conventional explosion in atmosphere can generate an EMP of sorts, to my understanding.)

[Astronomiya]

Not so! This is a common thing to say but not striiiiictly true. In atmosphere the mighty EMP is produced by pumped-up air molecules relaxing and letting out photons. Even in vacuum, however, the explosion itself will release light, which is by definition an electromagnetic pulse. I doubt it'll have any effect on hardened military equipment whatsoever, though.

Your second and third sentences are correct, but not the first.  There are three components to an atmospheric EMP, named E1, E2, and E3.  E1 is what I was talking about, and is what does most of the damage, given its incredible speed (less than a microsecond) and high strength (up to 6.6 MW/m^2).  E2 is caused by the Compton scattering of gamma rays towards the Earth's surface by the atmosphere; it is generally no more harmful to protected electronics than a lightning strike would be.  E3 is a geomagnetic-storm like effect cause by the explosion literally pushing the Earth's magnetic field away from the detonation point, followed by the field relaxing back to its previous configuration, just like after a CME.

In space, E2 will be the only significant pulse, and it won't do anything to military electronics, especially since spaceships are giant Faraday cages.  So yeah, I guess it's wrong to say "no EMP in space," but "no EMP that matters in space" still holds.

[Herra Tohtori]

Yes, that would work - for all the ships in close proximity. Would be interesting to do the math on how much gamma radiation would be needed for hull plating to absorb enough energy to start significantly heating up, though. It'll cause radiation sickness long before that happens, I would wager, but don't take my word for it, it's just my intuition.

Not necessarily.  We can assume the armor plating is not very thin, and is probably made of uber-materials up to a meter thick in places (SWAG though this may be).  I would wager that these would be able to absorb almost all of the gamma flux, and most of this would go into shock heating the armor, causing deep cracks, vaporization, and all around failure of the hull.  It most likely would not push it around much.

Shock heating basically is what I was talking about. Depending on the thermal capacity of the hull material and the temperature jump (caused by the absorbed gamma rays' energy) it would be interesting to know how much of a temperature jump the hull could withstand, and also how much of the absorbed heat could be radiated back into space and how fast.

The problem is, gamma rays spread evenly from a point source, and their effectiveness reduces in inverse square of distance. The even distribution means that at reasonably short distance, they won't be doing much damage at all (at least immediate damage - they may cause radiation sickness, but that doesn't immediately put a warship down like compromised hull structure will.

If you instead convert most of the energy from the reaction into kinetic energy (assuming you can do this) and send shrapnel from the blast site, you get a much more "coarse" distribution of possible damage - but at the same time, the damage delivery is more efficient. The probability of getting hit by pieces of shrapnel will decrease in the inverse square of distance, but individual pieces of shrapnel don't lose their initial kinetic energy, which means the individual pieces of shrapnel retain their effectiveness regardless if distance, unlike a free gamma burst.

You can't do this.  Because the gamma rays will have essentially random momenta and energies (with several peaks around the annihilation energies of the various particles), the absorption of a whole lot of them will not be very effective at propelling something in the direction you want it to go without converting most of the kinetic energy the gamma rays had into thermal motion.

This is exactly what I described. Basically what I suggested was to surround the annihilation source with a shell (or mantle) of material with high attenuation coefficient, sufficiently thick to absorb majority of the gamma burst and vaporize as a result.

This core device would be surrounded by the shrapnel pieces, which would be accelerated into great speed by the expanding vapours.

What I ignored in my calculations is the thermal energy required to heat the mantle mass and vaporize it. Which, depending on material used and its amount, might cause a significant energy bleed from the available kinetic energy for shrapnel.

This has the side effect of vaporizing anything you might want to encase the bomb with (find me a material that can withstand millions of Kelvins, and we'll talk).  This also has the side effect of rendering the rest of your post moot, though your math looks right, even if you did use way too many sig figs.

The idea would be to use high-density mantle mass that would absorb enough gamma rays to vaporize, and the expanding vapours would generate both a mechanical shockwave (as well as an EMP since it'll essentially be totally ionized plasma) and accelerate the shrapnel pieces outward from the detonation center.

Problem would be to make the mantle out of a material that has high gamma attenuation factor (density), and the absorbed energy should be sufficient to vaporize the mantle while leaving most of the shrapnel materials relatively unaffected.

The best bet is to detonate the bomb as close as possible to the hull of the enemy ship, to compromise its hull through extreme shock heating.  We see this in game as well, to a more ridiculous degree, where a near miss does jack squat, while a direct hit can be some major hurt.

That is definitely the simplest way to utilize an annihilation based explosive device.

Just trying to figure out a way to convert gamma burst into kinetic energy, and gamma->thermal->kinetic felt the simplest, though in hindsight I realise I did forget to subtract the required thermal energy from the available kinetic energy. And now I realize that the thermal to kinetic conversion isn't quite simple because I would have to calculate the vapour expansion velocity as function of time (v(0) would have the highest value and would give the upper limit for the shrapnel velocities), vapour density as function of time, and based on that calculate the force it would exert on a piece of shrapnel... gah. A bit too complex to do on my free time.

[FoeHammer]

This may sound like a stupid question, but wouldn't it be simpler to just allow the antimatter to hit the ship and annihilate whatever material the hull is made of?  It seems to me like this would have a far more devastating effect than relying on the explosions themselves to take care of it.

[The E]

Easier, yes. But not more destructive. A properly shaped and designed warhead can be more reliably destructive, and more efficient, than a simple application of AM to the hull.

[General Battuta]

This may sound like a stupid question, but wouldn't it be simpler to just allow the antimatter to hit the ship and annihilate whatever material the hull is made of?  It seems to me like this would have a far more devastating effect than relying on the explosions themselves to take care of it.

Not...necessarily. You can't guarantee that all the antimatter in your warhead will annihilate properly with the hull, and the blast will be omnidirectional (in fact, guessing intuitively, most of it will probably 'richochet' back into space.)

Doing it inside your warhead allows you to maximize yield and maybe even get a nice jet of radiation and plasma going.

[Dragon]

If a torpedo buried itself inside the the armor and propelled antimatter forwards so it only anihilates with a small part of the warhead's nose and hull plating in front of it could also be effective. I don't have any equations for that though.

[-Norbert-]

As an anti-subsystem weapon that also does some hull damage?

[Snail]

If a torpedo buried itself inside the the armor and propelled antimatter forwards so it only anihilates with a small part of the warhead's nose and hull plating in front of it could also be effective. I don't have any equations for that though.

Shaped charge antimatter?

[Astronomiya]

Shock heating basically is what I was talking about. Depending on the thermal capacity of the hull material and the temperature jump (caused by the absorbed gamma rays' energy) it would be interesting to know how much of a temperature jump the hull could withstand, and also how much of the absorbed heat could be radiated back into space and how fast.

Assuming a direct hit, the radiation dump will be easily enough to vaporize any material you care to put there, no matter how transparent to gammas it is.  As strong as FS ship hulls are, to my knowledge they cannot withstand a million degree instant temperature change; no conceivable atom can withstand that kind of temperature, much less molecules and macroscopic materials.  This will cause a very destructive shockwave to propagate through the hull, most likely thoroughly compromising it in the affected area.  Going to game mechanics (yeah, I know, I know, but we don't have anything else to go on), since we don't see large portions of ships getting utterly vaporized by Harbingers/Helioses, we can assume they have some sort of field or super dense material that is able to "conduct," as it were, most of the received energy all along the ship's hull, spreading it out and preventing the ship from being destroyed immediately on impact.  Therefore, when a ship's hull is "critical," this whatever it is is at capacity, and will soon be unable to control where the energy goes, resulting in the ship going kablooie.

This is exactly what I described. Basically what I suggested was to surround the annihilation source with a shell (or mantle) of material with high attenuation coefficient, sufficiently thick to absorb majority of the gamma burst and vaporize as a result.

This core device would be surrounded by the shrapnel pieces, which would be accelerated into great speed by the expanding vapours.

What I ignored in my calculations is the thermal energy required to heat the mantle mass and vaporize it. Which, depending on material used and its amount, might cause a significant energy bleed from the available kinetic energy for shrapnel.

You would need a large, not very dense medium to do this properly, because you need to spread the energy out over a large enough area that whatever the initial casing comes into contact with isn't vaporized, etc.  This makes for a rather unwieldy bomb.  Far better to just get the bomb real close and let the gamma rays do their dirty work.

That is definitely the simplest way to utilize an annihilation based explosive device.

Just trying to figure out a way to convert gamma burst into kinetic energy, and gamma->thermal->kinetic felt the simplest, though in hindsight I realise I did forget to subtract the required thermal energy from the available kinetic energy. And now I realize that the thermal to kinetic conversion isn't quite simple because I would have to calculate the vapour expansion velocity as function of time (v(0) would have the highest value and would give the upper limit for the shrapnel velocities), vapour density as function of time, and based on that calculate the force it would exert on a piece of shrapnel... gah. A bit too complex to do on my free time.

The problem is that without something like the Earth's atmosphere to attenuate the radiation over several hundred meters or so, and thence violently thermally expand, the thermal effects are so overwhelming as to utterly vaporize anything you try to encase the bomb with.  This is why nuclear weapons are ultra-super awesome tools of destruction on Earth, but merely awesome tools of destruction in space.  A very good explanation of how nukes (and by extension, M/AM weapons) work in space can be found at this site.

Shaped charge antimatter?

Yup.  The site I link to above also describes a design for a nuclear shaped charge that would work for an M/AM bomb with a little modification.

[Snail]

Shaped charge meson bombs.

[SomeGuyWithAName]

I am beginning to love this thread more and more, because I am actually learning quite a bit of pop-science sci-fi pseudoknowledge, which I absolutely love to death.

Now, because I obviously lack the knowledge of both physics and weapon technology of others in this thread, let me say this as sort of a "dumb question":

In my imagination the best way to use antimatter bombs would be a shaped charge, which something like a 60/40 antimatter/matter ratio. In my sci-fi imagination it would work thusly: Concentrate the gamma burst as much as possible, and weakening the structure of the hull at the same point, by concentrating a stream of energized antimatter into the hull.

Now comes the part where I really am unsure if this would work as I think: In the highly energized surroundings I would expect the antimatter overflow to annihilate parts of the armor - of course on a nuclear level. That would mean that the elements of the alloy change, probably also become unstable isotopes, and themselves cause alpha and beta decay, which then could also further affect it's surroundings.

(Of course, one would assume in the immediate area, everything would break down no matter what, with the mere amount of energy released, so it actually may be completely pointless to begin with, now that I think about it)

If they would really use some sort of sci-fi super-dense elements from the island of stability like Ununquadium, I could imagine it breaking down completely in an array of decays down to a sub-Uranium level eventually.

Also, due to part of the reaction taking place inside the hull, the resulting energy should also be absorbed more efficiently by the hull, while even a shaped charge would waste most of it's energy into space.

As I said, I am really not that knowledgeable about it, and even though we can't really talk about realism anyway, all of the above is just a pile of half thought ideas...  I love making things up with the little bit of trivia in my head. I actually had an idea of even more ludicrous ways, involving using sci-fi-plot-energy-fields to condense it into a cascade of small antimatter black holes, which would then burst into a mixture of Hawking radiation and "piled up" gamma radiation as soon as they lose their mass inside the hull. I highly doubt it would even begin to work, but it just sounds so wonderfully, ludicrously absurd.

Now, meson bombs... They are completely up to our imagination in how they are supposed to work I guess? I mean, did they explain it in Freespace lore or did they do what any sensible Sci Fi writer does: Add the word bomb to a cool sounding particle?

[General Battuta]

Meson bombs almost make sense.

quark-gluon weapons **** yeah

[-Sara-]

I always wondered why subspace wasn't explored further by the GTVA as a direct weapon. Spawning a subspace aperture inside the bowels of a spacefaring vessel can be quite devastating. With the technology reverse engineered from the Knossos portal it should not be too farfetched.

[-Norbert-]

I guess it might have something to do with the GTVA only starting to dabble in such technology. Even the rapidly recharging jumpdrives of the Carthage and Arteus are officially labled experimental technology.
But if I have the techroom describtions correctly in my head the Vishnan bombs utilize subspace.

I wouldn't be surprised if the GTVA and/or the UEF would build like weapons (allthough much weaker of course) from the scan-data the 14th battlegroup collected from Vishnan weapons in WiH 2 or BP3.