Slashdot Mirror
Design Starting For Matter-Antimatter Collider
couch_warrior writes "The Register is carrying a story on the early design efforts for the next generation of high-energy particle accelerators. They will be linear, and will collide matter and antimatter in the form of electrons and positrons. The obvious question will be: once we have a matter-antimatter reactor, how long till we have warp drive, and will the Vulcans show up for a sneak-peak?"
The obvious question will be: once we have a matter-antimatter reactor, how long till we have warp drive, and will the Vulcans show up for a sneak-peak?"
Maybe in a Star Trek convention...
Keptin, I'm giving you all she's got!
The obvious question will be: once we have a matter-antimatter reactor, how long till we have warp drive, and will the Vulcans show up for a sneak-peak?"
Actually, I think the next question would be: "Now how can get some antimatter?"
It's my understanding that we can only manufacture ridiculously minute quantities of the stuff, and that may take more energy to make than we'll get out of it anyways.
Unfortunately, a matter/anti matter reactor is not enough to create an Alcubierre drive.. We still need some Exotic Matter.. And a lot of it..
So .. go back to sleep.. nothing to see here..
--Ivan
There's a matter-antimatter collider in production since the 1990's. It's called the Tevatron, it collides protons with antiprotons and it is in Illinois.
The +/- designs are last gen ^ X, not next gen. If The Register followed the history details closely, a good number of computer startups came from a club that met at SLAC, the Stanford Linear Accelerator. Yes, the design is that old and older.
As for the 'obvious question', if the supposedly obligatory SF reference comes out sounding like so much shite, leave it out, OK?
Between these two details, TFA could have predated /. by a decade.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
They should be OK as long as they don't use any of those damned Klingon Crystals. Otherwise they'll need access to the nuclear wessels.
There were already some electron-positron colliders, the LEP for example. I think the new thing about this collider is that it is a linear and for high energy. In an electron/positron synchrotron the particles are flying in circles, permanently loosing energy to synchrotron radiation. This is why a linear design will allow to achieve higher energies.
PET scanning uses radioisotope Beta decay to Neutron, Neutrino and Positron, Positron -> Electron annihilation -> Gamma -> detection.
This is using an existing source of positrons, beta radiation.
http://en.wikipedia.org/wiki/Positron_emission
The non-trivial stuff is making anti-atoms. That's quite difficult.
http://en.wikipedia.org/wiki/Antimatter#Artificial_production
Contrary to popular belief, life is not a bitch. It is far far worse.
Peak: top of a mountain.
And the daily Slashdot malapropism award goes to samzenpus.
You're wrong, cooling is a major issue in orbit (only radiative cooling works), power would also be a major issue and that's not including all of that lovely high energy radiation you get in orbit disrupting your delicate experiment.
until some space-junk slams into it.... ;-)
... is what it used to be called. CERN in Switzerland had it. http://en.wikipedia.org/wiki/Lep
There are always many different designs being investigated, even up to fairly advanced stages. This doesn't mean that any of those is going to be build. You have to realize that in order to make decisions that cost several M$, you have to know what you can do and how to achieve it beforehand, in great detail.
CLIC is definitely one of the bigger things currently in investigation. The ILC (lepton machine) is another one. There's also big interest in Neutrino Factories, Superbeams, Betabeams, etc.
What we want to build (maybe in 2020) depends crucially on what the LHC finds and on new results in the neutrino sector (measurement of the 13-angle).
It is more likely that a representative from the Intergalactic Patent office will show up and attempt to begin negotiations for royalty premiums.
Participatory Governance : The only feasible option for a real democracy, where everyone really does have a say.
It's about wakefields and the possibility of reducing their external effects by detuning. What makes this interesting is that the proposals for next-gen small accelerators are about deliberately using wakefields to achieve very high acceleration over very short ranges, effectively getting particles to surf on laser-induced wakefields.
The guy with the proposal also manages to give a spectacularly bad example of detuning - bells, anyone? - which fully complies with the Bad Analogy requirements, i.e. detuning is nothing at all like having lots of bells, and the analogy doesn't provide any insight at all into what is happening. Detuning is more like resting a finger gently on a vibrating guitar string.
All this article really tells me is that wakefields are very hot in particle accelerator research, and efforts are focussing on reducing their unwanted effects as well as extracting more energy from them.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
maybe by Prostetnic Vogon Jeltz himself now back to the poetry
Kind of like your karma points for that comment ;)
Okay now correct me if I'm wrong on this, but if I remember correctly, Positrons and Electrons are in the group of Leptons. More generally they are a type of fermion. I understand that fermions make up Baryons and so forth, but aren't we getting ahead of ourselves when we call this reactor a "matter-anitmatter" reactor? Wouldn't it be more fitting to call it a "particle-antiparticle" reactor?
Are you lost?
Genesis 1:32 And God typed
I thought it had something to do with time... Like, positrons were electrons going the other way in time, which is why they annihilate when they collide and produce a photon. Really the electron is hitting a photon and turning around in time. Likewise with pair production. Anyone know if this is right? I honestly think that quantum physics book was chock full of lies...
When you're afraid to download music illegally in your own home, then the terrorists have won!
As preparation for the PET scan you were given an injection with a radioactive tracer which decays via positron emission. The PET scanner doesn't generate any radiation, it simply detects the 511 keV gamma rays produced when the positrons in the tracer annihilate with an electron.
Actually, IIRC Dirac predicted a particle with negative mass. Depending on how you do the math, opposite charge and negative mass can have the same behavior. It is still an open question how gravity affects antimatter, and some folks are trying to figure a way to measure it.
Damped detuning is precisely absorbing energy in such a way that the spectrum broadens, the guitar string analogy. "Damped" = removing energy, "detuning" = broadening spectrum.
This is like a system of resonators all with slightly different peak frequencies which cannot co-excite one another, which is neither damping nor detuning. If you want to see an everyday damped detuning system, look under your car at the engine mounts. Not only do they absorb energy (the rubber is deliberately made with energy-absorbing additives) but as they are compressed their stiffness varies, thus changing the resonant frequency of the engine assembly during the vibration. Does that look like a ring of bells?
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
I thought it had something to do with time... Like, positrons were electrons going the other way in time, which is why they annihilate when they collide and produce a photon. Really the electron is hitting a photon and turning around in time. Likewise with pair production. Anyone know if this is right? I honestly think that quantum physics book was chock full of lies...
If I remember correctly, that theory comes from Feynman diagrams. It is a pretty interesting theory, and you can get some other very interesting ideas out of it. As with most other aspects of particle physics, how "true" it is can be debated at length, but the mathematics works, which is probably enough for most physicists.
and opposite spin...
For sure! I mean, like they're not really annihilating each other, it's just a game they play. It's for the best anyway.
Anybody remember that poem about when Dr.Edward Teller met Dr.Edward Anti-Teller?
Do not mock my vision of impractical footwear
and you'll shut up most of the people that are gonna bitch about it blowing up a killing us all
I doubt it. Many of those people seemed like the sort who are noisy regardless of whether or not they really have anything useful to say.
Space game using normal deck of cards: http://BattleCards.org
Anti-Matter is like matter, but with a opposite
property (spin, charge, etc) that nullify between
them, releasing photons (and neutrinos and
another fancy particles)
Actually, you can collide anything vs anything,
but you need to see the quark composition of the
particles to try to predict the outcome (pretty
hard, cause everything will collide vs
everything, primarly the target ones, next the
newly formed particles, just with fewer
interactions...
from wikipedia http://en.wikipedia.org/wiki/Antimatter
"In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. For example, an antielectron (a positron, an electron with a positive charge) and an antiproton (a proton with a negative charge) could form an antihydrogen atom in the same way that an electron and a proton form a normal matter hydrogen atom. Furthermore, mixing matter and antimatter would lead to the annihilation of both in the same way that mixing antiparticles and particles does, thus giving rise to high-energy photons (gamma rays) or other particleâ"antiparticle pairs."
No.
I drank what? -- Socrates
Actually, the technical paper was published a few months later, in one of the most respected scientific journals in the world, Physical Review Letters. Please see "Relativistic Positron Creation Using Ultraintense Short Pulse Lasers" H. Chen, et. al., Phys. Rev. Lett. 102 , 105001(issue of 13 March 2009) In addition to this, these results were also reproduced at the LLE laser facility at the University of Rochester, where an order of magnitude more positrons were observed, over what was reported in the original new release.
Citation needed
wha'? where am i?
Here's the basic concept: positive-energy antiparticle travelling forwards in time == negative-energy particle travelling backwards in time. Note that in the 'real' world, only positive energies are possible, so we observe both particles and antiparticles with positive energy.
In a bit more detail:
The expression for the propagation of the particle contains an oscillating exponential term:
exp(-i*E*t)
where E = energy and t = time (hbar is set to 1).
Using the equivalence I mentioned above, both energy and time are multiplied by -1 for an antiparticle, so we have:
exp(-i*-E*-t) == exp(-i*E*t)
- so the net result is the same in reality.
Feynman diagrams don't show time flow - just 'beginning', 'middle' and 'end'. However all antiparticles are drawn with 'backwards' arrows to reflect the situation described above. Even though in reality they are travelling forwards in time, we can also think of, say, an electron colliding with a photon and then moving away backwards in time, as alluded to in the GP. It's a piece of mathematical trickery or a fundamental underlying truth, take your pick...
Check in LLNL's annual reports, going back to 1944. In none of them will you find a mention by me of knowledge of a poem about Dr. Teller. In fact, if you scour all academic journals, LoC, and wikipedia, you will not find any mention of my knowledge of any poem, outside of J. R. R. Tolkien's Cat . My non-knowledge of poetry about physicists is quite well non-documented.
I drank what? -- Socrates
There can be only 1.
Why is it so hard to only have politicians for a few years, then have them go away?
April 5th 2063 Duh!
Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
Redundant? No, it was an honest mistake and I really don't think that moderation was fair. It's quite clear he had meant to type "fr1st p0st!!!" but had his hand offset on the home row by one while he was typing. Growing up on Macs which had the little keyboard indicator nubbies under the middle fingers instead of the index fingers, I would frequently type out something in the IRCs and not realize my mistakeuntil I had already told everybody gege tgat;s wgat tiyr nin saud kast buggt!!
+1 Disagree
And then we can all flashforward 2 Min 17 Seconds.
It could explain why we see more matter than anti-matter. We're less than 50% of the way through time. Think of the matter/antimatter ratio as a universal progress bar...
But quotes for the "free market cost of antimatter" are based on the fantastic costs of generating it in an accelerator.
Why pay? - antimatter is available for free! One cosmic ray passes through every cubic centimetre of your body every second that you stand on the Earth's surface and about half are anti-muons. In addition, since they are available everywhere on Earth (and other planets with atmospheres) storage is not a problem - wherever you go there will still be anti-matter there for you!
They probably started testing the technology: http://www.russiatoday.com/Top_News/2009-10-08/ufo-halo-sky-baffles.html
CERN's LHC is notable for being the first collider that doesn't collide antiparticles. Colliding antiparticles is the standard design.
You might remember that the tunnel LHC is using was previously occupied by the LEP collider, which stands for "large electron/positron". The Tevatron also collides protons and antiprotons.
Since protons and antiprotons curve in opposite directions in a magnetic field, it's very convenient to build one set of magnets and use them for `two beams of particles in going in opposite directions.
LHC, as the first proton/proton collider, has a much more complicated magnet design because it needs to generate two different magnetic fields. But the number of particles it needs is so high that it was impractical (and even more expensive) to generate that many antiprotons.
Yes! Although the citation is sadly, not complete - there was a point where they shook hands and disappeared (presumably to the accompaniment of four quanta of extremely hard radiation).
Do not mock my vision of impractical footwear
by biryokumaru (822262)
by Dragonslicer (991472)
As I recall, there was a half-way serious proposal by Wheeler (http://en.wikipedia.org/wiki/John_Archibald_Wheeler) that the entire electron+positron (+/- photon? I'm not sure) count of the universe was simply one electron ricocheting forward and backward through time, occasionally meeting itself coming/ going, annihilating and spending part of it's voyage as a photon. ... in one of Lawrence Krauss' books, perhaps?
I remember reading it
Sorry to be so vague - I made notes ; they're in my PDA ; my PDA won't boot; and the backup is on the server at home, which I won't see for a couple of weeks.
Ah, Google helps. Search for "Wheeler electron positron "backwards in time" "
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"