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CERN Antimatter Experiment Produces First Beam of Antihydrogen
An anonymous reader writes "Matter and antimatter annihilate immediately when they meet, so aside from creating antihydrogen, one of the key challenges for physicists is to keep antiatoms away from ordinary matter. To do so, experiments take advantage of antihydrogen's magnetic properties (which are similar to hydrogen's) and use very strong non-uniform magnetic fields to trap antiatoms long enough to study them. However, the strong magnetic field gradients degrade the spectroscopic properties of the (anti)atoms. To allow for clean high-resolution spectroscopy, the ASACUSA collaboration developed an innovative set-up to transfer antihydrogen atoms to a region where they can be studied in flight, far from the strong magnetic field (scientific paper)."
Sulphur Hexafluoride already does this.
This may be a case where the experts are too close to the problem to see the simple solution.
Put the antihydrogen in a container made of antimatter, then annihilation will not be an issue.
Perhaps some sort of rigid anti-dirigible
Stuff that anti-matters.
'Weapons that don't work if there is matter between you and the target' are probably kind of a niche at present...
There are no known reports of fatalities due to it, and there are no regulations against its use, so I conclude it must be perfectly safe!
What a fool believes, he sees, no wise man has the power to reason away.
So, basically, if an enemy got hold of this, it wouldn't matter? ;)
http://arxiv.org/abs/1106.0847
One of the most interesting physics papers I've read in recent years. Does away with dark matter by presuming that antimatter has the opposite gravitational sign as matter (which pops out very naturally once you apply CPT to general relativity).
As the electromagnetic force is almost 10^40 times stronger than gravity, it would be virtually impossible to test with anti-protons or positrons. But with electrically neutral anti-hydrogen, it becomes potentially testable.
Note that it can settle in the lungs, if you inhale too much and can't exhale it you can suffocate. You won't feel it either because the CO2 will rise and exit the lungs. If you experiment with breathing it in, stand on your head after a few seconds and breathe out/in deeply.
Not a sentence!
The annihilation of a single hydrogen atom probably isn't going to hurt much, it's not that much energy.
Parent and GP's suggestions might work in SF, but in real physics, a powerful laser blast will just break the ordinary matter into smaller pieces, which will still be sitting in the way. As for the positrons, they won't quite annihilate the ordinary matter; some of them would annihilate with electrons, but most of them would convert neutrons into protons, if I remember the nuclear chemistry chapters of my bachelor's courses correctly. The resulting unstable cores would either decay or fission, but the products would still be ordinary matter, and no matter (pun not intended) how long you keep repeating this, there would still be a lot of ordinary matter left that cannot be converted to energy any further by bombarding with positrons.
Here's a serious answer, just in case you're not going along with the joking tone of the 2 posts I replied to...
I thought we were (implicitly) talking about the presence of air making terrestrial use of the weapon impossible. Particles coming loose tend to fly around at high speeds is somewhat random directions. Some of them will remain in the way of the antimatter projectile/beam, some of them will go out of the way but hit a molecule and return where they came from, some of them will create some backscatter effect (like a billiard ball being launched at high speed on a pool table full of other balls), causing molecules of air to get into the way. Even if one could fire a hypothetical ray that clearly annihilates all matter ahead of an antimatter projectile/beam, air would quickly rush into the vacuum being created (of course, having such a ray at one's disposal would mostly remove the point of using an antimatter projectile/beam). Whatever happens, there won't be the necessary hard vacuum for the antimatter projectile/beam to proceed. Even air at very low density would exert an incredibly strong braking/beam dispersal force because of the energy released when it collides with antimatter.
Also, in the present discussion, gravity is far too weak a force to be relevant at all. If you have to wait for gravity to remove stuff out of the way, air will have been given time to take that stuff's place a hundred times over. That's why there's no hard vacuum behind objects in (subsonic) free fall. Now in space, there is no air, but little gravity either...
They turn into "energy", but it may not be very straightforward. Electrons and anti-electrons (positrons) usually annihilate to a pair of gamma rays - about as close to "pure" energy as you can get.
Anti protons and protons annihilate in a more ugly fashion since each is a bag of quarks. You can get pions that decay into neutrinos and muons which then decay into positrons and neutrinos. The muon decay is fairly slow - ~2 microseconds, enough for them to travel almost a kilometer.
In the end you get gamma rays, neutrinos (of various types), electrons and positrons. The combined energy (both their mass energy and their kinetic energy) of all the particles adds up to the original mass energy of the matter and antimatter, and any other energy put into the process.
Because protons and anti-protons are complex, it is very difficult to make anti-protons - only something like 1/100,000 collisions generates one, the rest just make pions and other junk. Then once you have the anti-protons its difficult to slow them down enough and cool them to where they will combine with the positrons. Is a very impressive and complicated experiment.
BTW- it is not a path to any reasonable energy storage, the efficiency of making anti-protons is much too low. I don't know of any even design concepts that would have usable efficiency.
I'm a proton, and it blew my electrons clean off, you insensitive clod! I had to move in with relatives to remain stable.
Table-ized A.I.