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GeV Acceleration In 3 Centimeters
Posted by
kdawson
on Tue Oct 03, 2006 11:01 PM
from the make-your-nose-bleed dept.
from the make-your-nose-bleed dept.
ZonkerWilliam writes, "Here is a very interesting article, for the scientific community at least, on an advancement in laser wakefield particle accelerators. Being able to accelerate electrons to 1 Gev in the space of 3.3 cm calls up visions of portable devices that can be used anywhere: think of portable cancer therapies, if they can do the same for positrons, portable PET scans, possible use in compact fusion devices, capturing the dearly departed, etc. The uses are mind boggling." From the article: "By comparison, SLAC, the Stanford Linear Accelerator Center, boosts electrons to 50 GeV over a distance of two miles... The Berkeley Lab group and their Oxford collaborators... achieve a 50th of SLAC's beam energy in just one-100,000th of SLAC's length." I doubt that this tech will fit on a table top anytime soon. The article quotes the Berkeley researcher: "We believe we can [get to 10 GB] with an accelerator less than a meter long — although we'll probably need 30 meters' worth of laser path."
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Blasters (Score:2, Funny)
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What is this "blaster" you speak of? (Score:4, Funny)
Why on earth would Han want to "blast" anything, as is? He's a perfectly legitimate businessman, brought into hard times by a pair of misfits who attack people with Mag Lites... or at least that's the latest Lucas version.
Parent
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heh (Score:2)
At last! (Score:4, Funny)
Forgive me for my lack of knowledge (Score:3, Interesting)
I'm not that educated in lasers, it wasn't as big of a study as mass-power mini railguns (no joking) to me. Someone PLEASE inform me and nobody bother modding me, I just want answers for my education.
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It might be that's what they mean by "laser path" above, i.e. even th
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They seem to have some ungodly powerful pen form-factor lasers as it is, good enough for cauterizing wounds or being visible in pure daylight with near any basic primary color during daylight. And these are for mainly military use, so I'd probably err on the side of caution on these guys as to the real power of even a LED-based laser, I fail to see how you're going to maintain a gas-based laser in that small of a form factor with the limited amount of powe
Re:Forgive me for my lack of knowledge (Score:5, Interesting)
That said, I don't see very many posts yet which address the central importance of this news. So let me do that now. THIS IS HUGE HUGE HUGE NEWS. I would be shocked if the LOASIS group weren't on stage with the king of Sweden in a decade or so. Seriously, that's how big this is. No one expected things to happen this fast in wakefield acceleration. No one. Just two years ago I posted a story [slashdot.org] here about the latest achievement of the same wakefield acceleration research group. They were then at 80 MeV electron energies over millimeters of acceleration distance using a 10 terawatt laser pulse. With 1,000-2,000 trillion watt (petawatt) lasers coming on line in the next few years [rochester.edu] and this new multi-cm acceleration distance possibility it is not beyond the realm of the plausible to expect to see hundred GeV, possibly even TeV energies coming out of these things. It takes the Stanford linear electron accelerator 2 miles to accelerate its 50 GeV electron positron beams! What we are witnessing is nothing short of a revolution in particle acclerators that will open up new frontiers of high TeV scale particle physics faster than anyone ever thought possible. This is the sort of breakthrough that happens once in 3 or 4 decades.... if you're lucky.
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Again, I may be wrong, but from the understanding I hav
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Who ya gonna call? Ghostbusters! (Score:3, Funny)
Holy Jesus, we can capture ghosts now with our 1 inch laser PET scans!!!
Reading between the lines. (Score:2)
So, are you saying that we can now capture ghosts with a particle thrower (Proton Pack). Damn, SciFi really DOES pave the way toward the future...
Excuse me now while I hide from the Stay-Puft Marshmallow Man!
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I'm glad Wikipedia has an article on "Ghostbusters equipment".
Now it just needs to be edited with this new information about GeV acceleration! We finally know how it works!
more to it than just how many G or TeV's (Score:2)
Imagine (Score:2, Interesting)
No seriously. If you can get 1GeV in 3cm and 10GeV in a few meters, the LHC is redundant before it got completed.
It would kick ass if a group of undergrads somewhere complete an accelerator with the energy of the LHC and start testing the weak theory days before the LHC becomes operational. What was the cost of it again?
Re:Imagine (Score:4, Informative)
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Yes, exactly! Because... it was... I mean, uh... wait.
Er. Nope. Sorry. Didn't understand a word of that.
Would someone care to translate?
Re:Imagine (Score:5, Informative)
You know those desk decorations that have about 5 metal ball suspended from wires? If you lift one and let go, gravity imparts energy on one of those balls. When it hits the next ball, it transfers energy to the other ball, which in turn hits the next ball, transfers its energy, so on and so forth. When the last ball has nothing more to hit, it swings out from the kinetic energy imparted on it. This is pretty much how electricity works.
An electron Volt is a method of measuring the kinetic energy for individual particles. It translates directly to the voltage/joules calculations we all know and love, except that it only involves one particle instead of a wire full of them. Most commonly, this term is used in particle physics where the energy of a single particle matters.
What has been built here is a micro particle-accelerator capable of imparting massive velocities on individual electrons. This is useful for things like advanced medical scanners [wikipedia.org] which bombard a target with a small number of high energy particles in order to get 3D image of the object. With a small enough particle accelerator, we could begin building devices like the medical tricorders you see in Star Trek. That's never been possible before.
Parent
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Well, this depends on what context you're talking about. In a metal conductor, you're absolutely right - an individual electron crosses a potential difference at a speed much much less (generally a fraction of a millimeter per second) than that of the effect of electricity (which is close to c). In a vacuum, when energy is imparted by a particle accelerato
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idiot editors (Score:5, Informative)
GeV = giga electron Volts
Also, TFA links to an illustrated version [lbl.gov] of the story.
Free Electron Laser (Score:2)
It can be tuned to just above the highest energy absorption line (the "K edge") of the chemical element, and that element can be used for total reflection mirror at grazing angles. Thus Lead can be used to create optic for FEL X-ray laser tuned to Lead K-edge. Effective X-ray laser becoming possible without any nuclear blast. And even portable X-
What fun! (Score:2)
-b
Tricorders? (Score:2)
Capturing the Dearly Departed (Score:5, Funny)
When using a portable particle accelerator, always remember this important safety tip:
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Portable???? (Score:2)
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The actual speed... 0.999999869 c (Score:4, Informative)
1GeV = energy = gamma * m * c^2 (gamma = 1/sqrt(1-v^2/c^2))
1 GeV / c^2 / m = gamma
1957 = gamma = 1/sqrt(1-v^2/c^2)
v/c = 0.999999869
Interesting fact: we usually hear about E = mc^2. That's the direct matter->energy conversion when the matter is at rest: if the matter is moving, we add on a factor of "gamma" -- which, at small velocities, is about 1 + 1/2 * v^2/c^2 (giving E = mc^2 + 1/2 mv^2, or rest mass + classical kinetic energy!)
Portable TW generator for my Toyota Prius? (Score:3, Insightful)
I'll get one of these, throw away the whole electron/laser surf part, and just use the portable 9TW generator in my Toyota Prius.
That should get me from 0 to escape velocity in 1 microsecond.
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If the pulse lasts only one attosecond, then 9TW gives you only nine-millionths of a joule. Not much energy at all.
Sadly, the responses to this confirm (Score:5, Interesting)
Reading the responses, there is frequently a lack of understanding of just how big this stuff is, just what it takes to produce things like wakefield accelerators and the difference between instantaneous power in watts and available energy.
Which reminds me of a true story. One company I worked for, the MD (aka CEO) decided we had to have a carbon dioxide laser to replace the ruby laser in one of our products. He talked to an academic researcher and asked how big the laser would need to be. The researcher said 10cm long and was promptly hired.
Six months later he had a prototype. The laser was a ceramic tube with fittings on a stand, genuinely about 150mm long with the fittings. Behind it was a room full of high voltage equipment, giant capacitors, carbon dioxide cylinders, extractor fans and, in fact, a water cooling system connected to a pressure main.
It took the MD a litle time to realise that this stuff was all part of making the laser go. He then asked when it would all be reduced in size to fit into a hand held box. The researcher's response? "You never told me you wanted the electrics to go in a box. You just said you wanted a four inch long laser."
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A slight misunderstanding (Score:4, Informative)
PET scans don't use accelerated positrons. A radioisotope is injected into the patient, which emits a positron when it decays. The positron immediately annihilates with an electron and emits two gamma rays. The gamma rays are detected and used to build the scan. To make the radioisotope you need a proton accelerator, but these are already very compact at 2-3m diameter, and anyway don't need to be near the patient.
Fusion, of course, has nothing to do with accelerating electrons.
I thought geeks knew this stuff, or do they only need to pretend these days?
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Try googling for "beam fusion" "inertial confinement fusion" and stuff like that.
Here:
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Fusion, of course, has nothing to do with accelerating electrons.
But it sometimes has something to do with accelerating charged ions. For example, accelerating protons at a target of 7Li or 11B could induce some degree of aneutronic fusion (ie, little of the fusion outcome would be energy-stealing neutrons). I don't think it'd be anywhere near breakeven, but it's a start.Re: (Score:2, Funny)
The racoons and possums I was able to deal with myself in fairly short order, but it took 18 years to get rid of that damned cat.
KFG
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I am starting an old computer museum, and I dont have
one of those yet.
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I don't know what kind of modifications you've done to your PET, but my PET can't do more than 40x25 character mode. So I don't really see the point in hooking a scanner up to it. Even if you find a vet from the great computer wars, I seriously doubt he'd be able to help. He'd probably just tell you to get a Commodore 64 instead. At least it had bitmapped graphics.
You kids and your screwy ideas.
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Cancer patients getting radiation treatment need a lot of care. I am not sure that they would have much of a chance of surviving at a local solar powered clinic with an MD and maybe a nurse running the show.
Local clinics need to provide general care. Ideally any seriously ill patent would be transported to a larger care hospital for specialized care.
The money that it would t
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It is not for electron beams that this would be a boon. It is rather for other particles (protons, heavy ions). The footprint of such facilities is pretty large. In the US there are currently a number of proton treatment centers. Protons allow you to generate more conformal treatments (e.g. treating tumor not healthy tissue) with very low levels of doses elsewhere in the body. The latter is important for patients expected to have long survival times (these are becoming more