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Anti-Matter Created By Laser At Livermore
zootropole alerts us to a press release issued today by Lawrence Livermore National Laboratory, announcing the production of 'billions of particles of anti-matter.' "Take a gold sample the size of the head of a push pin, shoot a laser through it, and suddenly more than 100 billion particles of anti-matter appear. The anti-matter, also known as positrons, shoots out of the target in a cone-shaped plasma 'jet.' This new ability to create a large number of positrons in a small laboratory opens the door to several fresh avenues of anti-matter research, including an understanding of the physics underlying various astrophysical phenomena such as black holes and gamma ray bursts." The press release doesn't characterize the laser used in this experiment, but it may have been this one.
Does anyone know how much energy this takes? They mentioned the previous petawatt laser experiment that was decommissioned, but I didn't see where it mentioend the power required for this experiment. If the laser guess by kdawson is correct, we could be looking at a mere 400 joules per 1E11 positrons. Which (if I'm not mistaken) would be an unheard of efficiency for creating antimatter! (Can someone verify? My brain is fried at the moment.)
What I find interesting is that this level of production is competitive with Fermilab. Even if they ran this twice an hour, they'd handily meet or outstrip Fermilab production.
Even more interesting is the possibility for mass manufacture of antimatter. By using mass-produced gold targets, you could rotate the materials in and out of the machine every few seconds, creating previously unseen amounts of antimatter. Such a process could easily provide materials for an antimatter catalyzed fission drive. Possibly even enough to power new forms of interplanetary propulsion.
Am I the only one who's getting really excited about this? /dreamer
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Take a gold sample the size of the head of a push pin, shoot a laser through it, and suddenly more than 100 billion particles of anti-matter appear.
It's so simple, I wish I'd thought of it!
Don't lase me, bro!
Be relentless!
You can't generate a net positive energy source with antimatter. Best you can hope for is to use the antimatter as a form of energy storage (think battery, fuel, etc). Of course, storage problems make it impractical for nearly every use, so don't expect anti-matter cars... ever. Space travel, however, would greatly benefit from a decent means of generating antimatter, since fuel mass trumps most other concerns in that field and anti-matter provides the most thrust/mass of any theoretical substance.
They created billions of positrons with a high power laser. The antimass(?) of a positron is the mass of an electron or 9.1E-31. Let's round it up and say we have 1E+12 positrons. Combine them with 1E+12 electrons, you get
9.1E-31*2E+12*(3E+8)^2=0.018 J.
Now I'm guessing the laser used is pretty powerful and that it consumes a lot of energy. If we take the specs of the laser linked in the summary, then it used 150J on one pulse which is not the true amount of energy they put into the device (it says it takes 30minutes between pulses at full power). The energy used is thousands or millions of times greater than the energy gained.
Of course, lasers might not be the most energy efficient way of creating antimatter but that doesn't change the fact that if you want to turn m matter into antimatter you will need at least 2*mc^2 energy (at least that's my intuitive guess).
Nuclear devices emit huge amount of energy with relatively small energy inputs because the reaction is selfsustaining, something inside the reaction keeps it alive. What you want is something that destabilizes matter and makes it turn into energy by, say, throwing a special particle at neutrons and/or protons. Turning it into antimatter only to collide it with matter afterwards is just a huge waste of energy.
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