I’ve got a crazy, silly question…could we, with todays technology, build an antimatter warhead, if we could actually somehow miraculously get ahold of enough antimatter on demand (say…13kg of anti-hydrogen) to make a decent “bang”?
And, if so, could anyone guess on how big a setup you’d need to contain the antimatter? Could it be portable enough to put on a ship, or even a large enough rocket?
For the record, I’m guessing the answer is “no, it wouldn’t work.” But, y’know, I’m still curious, and it couldn’t hurt to find out for sure. So…can anyone enlighten me?
[And I’m going to assume that no one has to worry about me trying to build one of these in my basement]
I’d say your biggest problem would be containing the stuff until you want the gigantic boom to happen. You’d probably need some kind of magnetic containment vessel and you’d live in fear of a power failure. Although maybe you could get away with just cooling it down to pretty close to absolute zero – then all you’d have to do to fire it is raise the temperature.
Sounds to me like the basic question is: what kind of setup would be necessary to keep 13kg of antimatter from coming into contact with any ordinary matter until you push the big red button and try to shove all of it into contact with ordinary matter at once?
I presume that a magnetic confinement of some kind would work if your antimatter was capable of being manipulated by magnetism. Antimatter plasma in a toroid, perhaps? I’m sure plenty of people here know about this kind of thing.
13 kg of antimatter?!!! Are you trying to blow up the planet?
[sub]please don’t say yes[/sub]
Well, if you had it in the form of anti-iron, you could suspend it in solid form in a magnetic ‘pocket’, inside a vacuum container. Just pray to Og that the suspension fields don’t go down before your weapon is at its target. On the other hand, it wouldn’t be radioactive, and would be harder to detect.
The tricky part would be introducing it to your regular matter (regular iron, perhaps?) in such a way that the explosions from the first matter/antimatter annihilations do not get in the way of the rest of them. (Unless, of course, that’s what you want…)
I understand that similar constraints limit the effects of really big fusion bombs: a bomb with 100 megatonnes does not yield 100 times the effect of one with 1 megatonne.
13Kg of antimatter would generate 23.4 × 10[sup]17[/sup] joules of energy and would likely blow off a substantial portion of the earth’s crust at the point of detonation and might destroy the atmosphere. You need to scale your weapon back just a tad.
To clarify this a bit: The basic net nuclear reaction in the core of a star is four hydrogen nuclei to one helium nucleus. But this doesn’t conserve charge, so we need to throw in a couple more positively charged particles on the product side of the equation. There isn’t enough energy available for more protons, so you get positrons (anti-electrons) out. These will eventually annihilate with whatever electrons happened to be around (there are as many electrons in the Sun as protons, so there’s bound to be some handy). A complete reaction would be something like 4 H -> He + 2 e[sup]+[/sup] + 2 [symbol]n[/symbol][sub]e[/sub] + photons, followed by e[sup]+[/sup] + e[sup]-[/sup] -> photons ([symbol]n[/symbol][sub]e[/sub] is an electron neutrino, e[sup]+[/sup] is a positron, and e[sup]-[/sup] is an ordinary (negative) electron). The photons released eventually transport the energy out of the core, through a long and winding path of many collisions, and the neutrinoes come more or less straight out, being nearly unimpeded by matter.
No antimatter makes it out of the core of the Sun, but some is involved in the process. Human-produced fusion reactions, however, generally use deuterium or tritium rather than hydrogen-1, and so need not involve any positrons.
Wait, is that just the energy in the antimatter, or the energy of the antimatter AND the equivilant mass of matter? By running your figure ( 2.34e+18, right?) through a couple of converters, I’m only getting a little over half a gigaton. (I could easily be screwing up my numbers, though.)
From my understanding, it leaks out of the magnetic bottle in a fairly short time, like a few minutes. Also, they only make a very little bit at a time, like about 100 atoms, although my info on this is several years old, so could be wrong. I’m talking about anti-hydrogen atoms here, not anti-protons and positrons, which are made in much larger quantities.
Check out issue 199 (Sept. 2005) of the Fortean Times for a one-page article on just this topic, with links to further info. It looks like the Air Force was–at least at one point–requesting research proposals for advanced weapons systems including “Positron Energy Conversion and Advanced Energetics”.
Yeah, I get 559.27 gigatons in my calculations too. That’s big, but Tsar Bomba topped out at 100 megatons, which isn’t too far away. .5 gigatons would be a huge blast, but not too big that it you couldn’t use it against far away enemy nations.
If you want to blow up the Earth, you are going to need 1,300,000,000,000 tonnes of antimatter, to overcome the Earth’s gravitational binding energy.
To me, positrons may be ‘technically’ antimatter, but should probably be qualified as such to not make people think you’re talking about a complete enough range of antimatter as to accurately mirror-reflect normal matter.
Specifically, in a thread about antimatter weapons, it kind of seems evident that people are going to be thinking about antimatter particles that pack a bigger punch… antiprotons and antineutrons for instance.
Even if you solve the problem of containment, there’s the difficult problem of getting enough antimatter to react at once. If you just released antimatter into the air, or brought it to contact with a solid matter, the first milligram of antimatter to react would scatter the rest of it in every which direction. It probably won’t be a very effective explosion, just a lot of heat.
Fission bombs have the same problem, only it’s more serious because it stops reacting as soon as it’s broken apart.
