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Anti-Matter Created By Laser At Livermore
Posted by
kdawson
on Tue Nov 18, 2008 12:28 AM
from the billions-and-billiions dept.
from the billions-and-billiions dept.
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.
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Hey! (Score:4, Funny)
Re:Hey! (Score:5, Funny)
Don't lase me, bro!
Parent
Quick question for anyone with the knowledge (Score:5, Insightful)
Does anyone know if this might someday lead to antimatter plants? From a special on discovery, I heard that antimatter has a 100% mass to energy conversion, and uranium/plutonium is very expensive to enrich, so using gold for energy wouldn't be too impractical. This would be very exciting research if it does mean cheap energy at that scale with no pollution.
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Re:Quick question for anyone with the knowledge (Score:5, Insightful)
No. While antimatter may have a 100% mass to energy conversion, it takes more energy to create it than it gives off.
Parent
Re:Quick question for anyone with the knowledge (Score:5, Informative)
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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Re:Quick question for anyone with the knowledge (Score:4, Informative)
Anti-matter has mass, ordinary mass, just like matter.
Parent
Re:Quick question for anyone with the knowledge (Score:5, Insightful)
The point is having the ability to produce lots of these particles in a directed manner, capture and store them for further study.
Previously the main source for antimatter was certain types of radioactive decay and nuclear reactions.
(example: if you go to the hospital for PET imaging - they inject you with radioactive material that decays by emitting anti-electrons = positrons)
If you want something that could potentially produce energy, this is not it - although in studying the process and the particles we might eventually learn how to produce antimatter more efficiently (to store energy) or perhaps even with net gain by inducing some sort of nuclear reaction.
Parent
Re:Quick question for anyone with the knowledge (Score:4, Funny)
You need to channel the matter and anti-matter streams through dilithium crystals.
I think you need to use anti-hydrogen though, not just anti-electrons.
Parent
Re:Quick question for anyone with the knowledge (Score:4, Informative)
Wow...reading this thread makes me a bit sad, and I can only hope that all the participants in this conversation up to now were not exclusively schooled in the US. (Sadly, I suspect it is so.)
Physics is the study of manifestations and transformations of energy. One of the basic laws of physics is that energy is conserved. If you pump so many GeV of energy in the form of coherent radiation into gold atoms, it seems from this article that some fraction of that energy is converted into positrons. When those positrons collide with electrons in equal numbers (as they're sure to do in this universe given even a very short period of time), the matter-antimatter pair annihilate each other and mass is converted back to radiation energy.
The amount of energy released in this annihilation is equal to the amount used to create the positrons in the first place, which is necessarily less than the energy of the laser light incident on the gold atoms. Some of that incident light is going to be lost knocking electrons off, knocking gold atoms out, heating the gold, getting absorbed and re-emitted as a different frequency of light, etc. We've only been looking at the actual point of energy transformation, too...if we go even further back in the chain, we have to look into the efficiency of the laser itself. Certainly less than 100% of the energy consumed by the device is emitted as a coherent light beam even before we look at how this beam is interacting with the gold.
So, by definition, antimatter cannot be a first energy source in this universe. Antimatter could be useful as a means of storing a large amount of energy, but not as an ultimate source. (Unless we find a naturally occurring, ready source of antimatter that we can harvest, which would probably require a wormhole to an alternate universe and a means of controlling that wormhole. Uh oh, queue up the Star Trek / Stargate SG-1 nerds...)
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Re:Quick question for anyone with the knowledge (Score:5, Interesting)
Parent
Re:Quick question for anyone with the knowledge (Score:5, Insightful)
Make hydrogen containers with very thin gold walls - or more likely frozen pellets coated with gold. Bombard the gold with a laser, turning the surface layer into antimatter. Antimatter annihilates with the matter below it and creates an explosion, which heats and compresses the hydrogen, igniting a fusion reaction.
It is, essentially, the equivalent of a fission-initiated fusion, which is proven to work and work well. The difference is that there's no lower bound to the size of an antimatter explosion - even a single electron and positron annihilate - so you can make the explosion be of suitable size for a power plant. And of course annihilation, as the name implies, doesn't leave behind radioactive materials, just gamma rays.
Besides, Laser Antimatter Fusion is pretty much the epitome of cool ;).
Parent
Re: (Score:3, Insightful)
Re:Quick question for anyone with the knowledge (Score:4, Interesting)
I heard on TV that an omnipotent sky monkey plans to torture us all in a volcano forever because some woman made out of a guy's rib ate a snack with a talking snake.
And that was supposed to be an education show!
Parent
Not enough anti-sunlight (Score:3, Funny)
> Does anyone know if this might someday lead to antimatter plants?
Nah, there isn't enough anti-sunlight for them to grow....
Holy Mackerel! (Score:5, Interesting)
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 [fnal.gov]. 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 [wikipedia.org]. Possibly even enough to power new forms of interplanetary propulsion.
Am I the only one who's getting really excited about this? /dreamer
Re:Holy Mackerel! (Score:4, Funny)
...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?
probably. they still haven't been able to crystallize di-lithium yet.
Parent
Re:Holy Mackerel! (Score:4, Insightful)
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.
The great thing about this for spaceflight isn't that it takes a lot or a little to produce antimatter, but rather that the density of usable energy is orders upon orders of magnitude greater than chemical or electric rockets. Denser energy leads to more fuel carried leads to greater delta v leads to semi-relativist flight leads to hate leads to suffering. These can even be used within the atmosphere to launch rockets from the ground easier than you can say "prompt gamma ray output".
Parent
Re:Holy Mackerel! (Score:5, Insightful)
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.
If true, this is the 1940s all over again -- only on a larger scale. A thimbleful of antimatter would make any H-bomb look like a popgun. (...and yeah, I know we're not yet talking about anywhere near that order of magnitude. Yet.) It would certainly help with space exploration -- but we humans can't even be completely trusted with gunpowder and jet airplanes yet. *sigh*
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Re:Holy Mackerel! (Score:5, Insightful)
Not really. We've already done the whole Cold War/Mutually Assured Destruction thing. Our weapons are already far, far larger than we could ever deploy here on Earth. Making them that much bigger only makes them that much more useless. At best, the only real advantage would be that they could be scaled down.
Until we start looking at warfare on an interplanetary or interstellar scale, our existing nukes and possible antimatter warheads are going to sit in their silos and go unused. Or in the case of antimatter bombs, I simply hope they're not built. The idea of a large-scale antimatter warhead being prevented from detonation by mere magnetic fields maintained by the nearest power plant is not an appealing idea. Just disrupt the power infrastructure for long enough and we'll blow ourselves to kingdom come. :-/
Parent
Re:Holy Mackerel! (Score:5, Informative)
Yeah, once. (Twice if you want to be pedantic.) Then never again. The whole point was that the display of force showed that the weapons were too dangerous to use. As long as the various sides have them pointed at each other, no one dares use them.
The only reason why the Cold War was so terrible was that the USA and the USSR were both waiting for the other to attack. Since neither one liked each other much (for both idealogical and practical reasons) the chance that an armed conflict would happen between the two powers was pretty darn high. Except that an armed conflict might precipitate into a nuclear war should either side feel backed into a corner.
Thus the reason why the US didn't win Vietnam. The chance of starting a nuclear war was too great to risk pressing the war to a conclusion. Which raised the (very legitimate) question of why we were even in the conflict to begin with.
Parent
Re: (Score:3, Insightful)
To say nukes were only used once or twice is terribly misleading. Nukes were only used in a military capacity twice. Even more accurately, they were only used in a military capacity against strategic targets twice. They've been used for political posturing and military advancement approximately 2,000 times [wikipedia.org] in various settings and with varied payloads.
This isn't intended to devalue the magnitude of the decision to effectively annihilate large numbers of human populations or suggest th
Re:Holy Mackerel! (Score:5, Informative)
If you're referring to Hiroshima and Nagasaki, you're wrong. Both of those devices were in the kilotons, not megatons.
Parent
Re: (Score:3, Insightful)
Which eventually lead to the solution of bankrupting the USSR. (Something which would have eventually happened anyway, just much slower.)
Or, to be exact, it didn't happen [slashdot.org].
Re: (Score:3, Informative)
LOL!!! ROFL!! I laughed so hard my drink came out my nose!
Representative Democracy? In what possibly way could you misconstrue that? The ruling elite (Elites, Politicians, Corporations, Military Industrial Complex) pass laws ALL THE TIME that no American wants.
The fact that a small percentage of us voted was just the decision being made between a Douche and a Turd Sandwich. Senators and Congressmen create and pass laws and funding measures all the time that only benefit th
Re:Holy Mackerel! (Score:4, Funny)
It wasn't a war, it was a police action.
Parent
Re:Holy Mackerel! (Score:5, Informative)
60e6*1e3 kcal / c^2= 2.8 kg [google.com] of antimatter will give any H-bomb look like.. uh.. something that's the same size as an H-bomb. H-bombs have been proposed (and postulated to have been built) that are larger than 60 MT, and a pop-gun typically has only a few Joules, so you'd need many orders of magnitude more than 2 kg of antimatter to make an H-bomb look like a pop-gun. something like.. four times the mass of mount Everest, in antimatter.
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Re:Holy Mackerel! (Score:5, Interesting)
Parent
Re:Holy Mackerel! (Score:4, Interesting)
What would happen if you aerosolized said cube with a small explosive?
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Re:Holy Mackerel! (Score:4, Funny)
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Re:Holy Mackerel! (Score:4, Interesting)
(60e6 * 1e3 kcal) / (c^2) = 2.7931967 grams. That is about a factor 1000 less.
The largest H-bomb ever build/detonated, the russian Tsar Bomb, was about 50MT, but capable of 100MT. I never heard of anything larger, but is/was there?
Parent
Re:Holy Mackerel! (Score:5, Informative)
It should be (60e6 * 1e3 kcal) / (2*c^2) = 1.39659835 since the normal matter that will also be annihilated will contribute to the mass-energy conversion.
Parent
Re:Holy Mackerel! (Score:4, Funny)
Possibly even enough to power new forms of interplanetary propulsion
Yeah, because NASA (and similar agencies around the world) have whopping piles of cash laying around for this.
Reporter: What's it like to fly the new spaceship?
Pilot: Like burning a load of gold as fast as I can!
Yeah, and you think the class warfare rhetoric between the rich and poor nations is bad now?!?
Parent
Re:Holy Mackerel! (Score:4, Informative)
Yeah, research dollars would never fund anything like that. Except when they [wikipedia.org] do [wikipedia.org].
Is it really so hard to click through the links? :-/
FWIW, there are quite a few antimatter engines on the drawing board. They're only missing one key component: Antimatter. And this new technology may be the key to providing it in spades. (Relatively speaking, of course.)
Parent
Re: (Score:3, Funny)
Re:Holy Mackerel! (Score:5, Funny)
Just use a zpm to power it.
Parent
Re: (Score:3, Interesting)
I don't think this compares with Fermilab. The fine article is talking about creating positrons, not anti-protons. This isn't the first time I've heard about creating positrons from a laser shown upon a gold foil target. Here are two (from 2004 and 2001 respectively) that I just found on Google Scholar describing a result and a theory behind the positron production:
http://llacolen.ciencias.uchile.cl/~vmunoz/download/papers/wclpp05.pdf [uchile.cl]
http://www-project.slac.stanford.edu/lc/local/PolarizedPositrons/doc/Class [stanford.edu]
Re:Holy Mackerel! (Score:5, Insightful)
Why is everyone so hung up on an energy-positive reaction? Antimatter is the ultimate in fuel for space-propulsion as it produces the highest theoretical amount of energy for the least possible mass. (i.e. 100% conversion - losses to nuetrinos that cannot be captured) This plays well into the rocket formula, giving antimatter drives a specific impulse unattainable with other rocket methodologies. In fact, the far-flung future may see c-ships [fourmilab.ch] traveling the stars based on matter-antimatter drives.
What I want verified is not if this process is energy efficient or not. I want to know if this process is several orders of magnitude more efficient than the current Fermilab and CERN processes.
Once again, antimatter catalyzation makes the fuel more efficient for its weight and thus plays well into the rocket formula.
Parent
Re: (Score:3, Funny)
That would probably be why I said, "i.e. 100% conversion - losses to nuetrinos that cannot be captured". Apologies for mixing in the minus sign rather than spelling it out. As I mentioned previously, it's late and my frain is bried. ;-)
Re:Holy Mackerel! (Score:5, Interesting)
I did the calculations for an earlier post:
If you accelerate at 9.8m/s^2 for half the journey and -9.8m/s^2 for the second half of the journey (so that it's just like earth's gravity) then you would arrive at the planet after:
1.94 arccosh(n/1.94 + 1) years
For n=10.5 light years, this gives 4.9 years.
For other values of distance:
4.3 ly nearest star 3.6 years
27 ly Vega 6.6 years
30,000 ly Center of our galaxy 20 years
2,000,000 ly Andromeda galaxy 28 years
(For distances bigger than about a thousand million light years, the formulas given here is inadequate because the universe is expanding. General Relativity would have to be used to work out those cases.)
So for someone in the rocket, they could arrive at the planet in 4.9 years.
If you had an 100% efficient engine (using anti-matter/matter), the fuel required would be:
d Stopping at: M
4.3 ly Nearest star 38 kg
27 ly Vega 886 kg
30,000 ly Center of our galaxy 955,000 tonnes
2,000,000 ly Andromeda galaxy 4.2 thousand million tonnes
I find it fascinating that within a human lifetime (for the people in the rocket) we could travel to another galaxy.
(I'm a theoretical particle physicist)
Parent
Re:Holy Mackerel! (Score:4, Insightful)
> you didn't account at all for relativistic effects at all.
It fully takes into account SR effects.
> A big question is how come you can travel faster than light
It doesn't. All times as for the people in the spaceship, as I stated. The reason it takes less time is because of time dilation.
> when you get to Vega everyone who sent you will be long dead.
Indeed.
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Re:Holy Mackerel! (Score:5, Insightful)
Time dilation and distance contraction. This are special relativity effects.
For the people on earth, the ship takes 4 million years to travel 4 million light years at close to the speed of light. But for people in the rocket, it can be a very short amount of time.
Parent
doh! (Score:5, Funny)
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!
Lasers (Score:5, Funny)
Is there anything they can't do?
Re:Lasers (Score:5, Interesting)
It's even more amazing when you consider that when lasers were first developed, no one thought they would have much practical use. They were "A solution looking for a problem."
http://www.press.uchicago.edu/Misc/Chicago/284158_townes.html [uchicago.edu]
Now, try to imagine modern technology without lasers...
Parent
Hot plasma jets! (Score:5, Funny)
The anti-matter, also known as positrons, shoots out of the target in a cone-shaped plasma 'jet.'
Apparently, it seems I can create anti-matter from eating too much TacoBell.
Wow PET scans anyone? (Score:3, Interesting)
This may open the possibility of cheaper PET scans. Currently, the limitation of PET scans is the answer to this question: "How far away is the nearest Cyclotron?" The half life of the radioactive material used in Positron Emission Tomography, typically Flourine-18, is ~110 minutes. With a laser that can generate positrons, you could have a mobile PET scan unit that would only need to rely on being able to connect to the grid.
BTM
Where's the boom? (Score:3, Funny)
I would think they're touching matter, since they didn't just harmlessly disappear.
Isn't there supposed to be an enormous explosion when matter and anti-matter meet?
Or is that fiction? or friction? Or fission? Or fusion? or confusion?
Re:Where's the boom? (Score:5, Informative)
You are fantastically overestimating how much they made. 100 billion particles seems like a lot, but it's actually only about 9.1x10^-17 grams (91 attograms). You could likely be physically standing right in front of the thing, in the middle of the spray of particles, and not notice anything.
Parent
Science Journalism Critique FAIL (Score:4, Informative)
Either that, or he/she just isn't a good writer -- that statement implies that all positrons are anti-matter and all anti-matter is positrons. Only the first statement is true.
Nice try, but not true. Your argument would be correct if the statement had read "Anti-matter, also know as positrons...", but it does not. Rather the author says "The antimiater, also known as positrons...".
This sentence only refers to the antimatter created during this experiment. And, near as I can tell, positrons are indeed the only form of antimatter produced in the experiment.
The lesson here - don't post smug messages denouncing someones incorrect grammar when their grammar is in fact correct. Check your facts.
Parent
Re: (Score:3, Funny)
That sounds dangerous. I, for one, am not willing to welcome our new robotic overlords! (Or regular human overlords with robot armies). Intel would need to come up with a scheme to keep the robots from harming people. Some sort of set of axioms... rules... laws, even... that would apply to all the robots they made, in order to keep them in line. Otherwise it would never work.