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The Athena Project - Creating Antimatter

Discussion in 'Serious' started by _rahoul, 2 Jun 2004.

  1. _rahoul

    _rahoul What's a Dremel?

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    This is truly amazing, i personally had no idea Physics had progressed so far. Scientists at CERN (http://www.cern.ch/) the worlds largest Particle Physics Laboratry successfully created antimatter. Now i quit studying science back in 1999 but this is incredible, right?

    For those that dont know: Antimatter is the most powerful energy source known to man. It releases energy with 100% efficiency (nuclear fission is 1.5% efficient). It creates no pollution or radiation, a single droplet could power New York City for a full day. Of course Antimatter is incredibly unstable, if it so much as touches matter (air, the ground anything) it "annihilates" the matter. A single gram of Antimatter has the destructive capability of a 20-kiloton bomb, ie: one the size of the H-Bomb dropped on Hiroshima.

    Here is the first published article
    http://athena-positrons.web.cern.ch/ATHENA-positrons/wwwathena/Documents/nature01096_r.pdf

    here is te Athena Project website
    http://athena.web.cern.ch/athena/
     
    Last edited: 3 Jun 2004
  2. RPC_Student

    RPC_Student Banned

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    /me considers the posibilities of an anti-matter ray gun
     
  3. Dgephri

    Dgephri What's a Dremel?

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    I guess the process of Antimatter annihilation may be 100% efficient, just remember to take into account the INPUT energy to create that source...

    How much power is needed to cool the apparatus, create the radioactive sources, contain the antiprotons and positrons, isolate the antihydrogen, detect the annihilation events, and collect the resulting energy?

    This may in fact only relate to 1-2% of the whole, who knows what the ratio is in the end.

    Indeed, when harnessed, it will be immensly useful but at the same time even more dangerous than Nuclear reactors (how about an antimatter leak?). I don't mean "Star Trek" style but imagine a single antihydrogen atom leak that first destroys a connection duct, then destroys the containment apparatus, then exposes all the antihydrogen into the positive matter nearby.
     
  4. calnen

    calnen moo!!

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    'Antimatter' is actually not as rare as all that. 11pm's a little late to go into it, but this isnt the first time it's been produced by any means. Basically, each fundamental particle in nature has an 'anti' equivalent, with the same mass but opposite charge, spin etc. An 'anti-electron' is called a positron - they're seen all the time as a bi-product of 'beta' (IIRC) radioactive decay. The only reason they're called the 'anti' particles is that the 'normal' ones were seen first, as they're more common.

    Anyway.
    I though I'd heard about someone producing a stable 'anti-atom' before, but guess I was wrong.
     
  5. nohope4me

    nohope4me What's a Dremel?

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    Antimatter's been produced in specialist labs for years. (Well, a few, anyway.)
     
  6. Guest-16

    Guest-16 Guest

    Not produced, isolated.

    They isolated a single anti-helium atom once iirc, then after studying it to totality let it out and it went *pop* :) from 1 atom!

    Dgephri - not only making it, but USING it as well. Nuclear reacters are so inefficient because the heat is used to heat water to turn generators etc so the amount of heat not used is significant. But with regards to antimatter - its like splitting the atom; could be used for good but will inevitably be used in bombs and another arms race.
     
  7. jonesie

    jonesie What's a Dremel?

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    You better believe it :)

    They're looking at creating larger molecules at the moment but it's damn hard to get those antiprotons and positrons sitting there for long enough to do so.

    positrons (anti-electrons) occur naturally from certain types of radioactive decay. antiprotons are made by smashing protons together. The collision energy causes a proton-antiproton pair to pop into existance, from where the antiproton can be harvested. Antiprotons were first observed in 1955 at the Bevatron in Berkeley.

    The reason I know a bit about this is due to my (and phaSe's) lecture prof and supervisor this year in germany being deeply involved in current antihydrogen production (well, ok, he was involved in the previous incarnation of ATHENA at cern :) ).

    Sorry, I'll stop showing off :p

    Besides phaSe is now gonna come correct some mistake I made (should have revised that course more!)


    so altogether quite funkeh..

    n.b. don't get any ideas about then being a viable power supply - it takes way more energy to power production than you get from the annihilation atm...
     
  8. phaSe

    phaSe What's a Dremel?

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    nahh ill let you off on that one :thumb:

    bindi - yes produced, but isolating it as well seems like a sensible idea....

    for those interested in why anit-matter is useful to study try looking up CPT violation and the standard model. (and of course, it just sounds cool!)

    RoB
     
    Last edited: 5 Jun 2004
  9. Uncle Psychosis

    Uncle Psychosis Classically Trained

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    Bizarrely enough, I actually wrote a research article based on that very paper at Uni last year :)

    Whats special about ATHENA is that they produced "cold" anti-matter- in order to use the anti-matter to test the CPT theorem they need it to have low energy, and so they need it "cold". However, you can't just take normal anti-matter and cool it down, because it doesn't work.

    Sadly, as some people have pointed out, anti-matter is not nearly as exciting as it sounds.

    I think it was Paul Dirac who first postulated the existence of anti-matter. Basically, every fundamental particle has an anti-matter equivalent- with opposite charge but other similar characteristics.

    The CPT theorem is to do with parity of charge, space, and time.

    If I remember properly, an anti-particle going backwards in time is the same as its corresponding "normal" particle going forwards.

    What they want to do at ATHENA is test the CPT theorem. Its quite hard to explain so I suggest google.

    The basic gist of it is that an electron circling a proton (ie a hydrogen atom) behaves the same as a positron circling an anti-proton.

    Its all very interesting, but I've rambled for far too long.

    Sam
     
  10. _rahoul

    _rahoul What's a Dremel?

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    lol

    i had just finished reading Dan Brown's book "Angels and Demons" and had read every site with reference to antimatter, CERN, the Illuminati and physics when i made this thread. It seemed very exciting at the time. Im just a poor Arts students newayz, all this stuff is so far over my head i cant even see the bottom of it.

    In my "home" forum, this same thread lasted 200 posts, but that was because ppl arent as educated as they seem to be here in Bit Tech and the discussion was mainly about Warp Drive and Osama Bin Laden making an Antimatter bomb :S . :duh:
     
  11. Uncle Psychosis

    Uncle Psychosis Classically Trained

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    I found the review article wot I wrote, here is a wee exerpt:

    "One of the key theories underlying modern particle physics is the CPT theorem. This theorem states that physical laws are invariant under the three combined operations of charge conjugation, parity, and time. In other words, if we replace a particle with its anti-matter counterpart, reverse the spatial-coordinates, and then replace time with “negative time” in our equations then the laws of physics should remain unchanged. That is, if we hold a “mirror” to the universe then we should not have to change anything.

    The CPT theorem has already been tested for invariance using the mass ratios of the electron/positron (a positron is an anti-electron) and of the proton/anti-proton. However, in order to test the theorem more thoroughly a more advanced experimental set-up is required.

    The hydrogen atom is one of the most studied systems in science. As a result, our knowledge and understanding of the hydrogen atom is extensive. An anti-hydrogen atom (figure 1) consists of a positron orbiting an anti-proton. According to the CPT theorem, if we were to study anti-hydrogen then we should gain the same observations as for “normal” hydrogen............

    ..........................The ATHENA scientists want to study the spectrum of anti-hydrogen in order to compare it to the known spectrum of hydrogen. In particular, they want to study the frequency of the transition from the first excited state to the ground state (the 1s-2s transition). In hydrogen, this frequency has been measured to an accuracy of 1.8 parts in 10^14. If they could measure the spectrum of anti-hydrogen to such a high accuracy then this would be an extensive test of the CPT theorem.

    In principle it is possible to obtain similar precision in the study of anti-hydrogen, but only if the anti-hydrogen atoms have low energies- i.e. if they are sufficiently cold (of the order a few Kelvin). However, this is easier in theory than in practice- anti-hydrogen particles cannot be cooled in a conventional manner because they annihilate when they interact with normal matter (i.e. liquid helium). For this reason, the anti-hydrogen required for study would have to be created cold. The ATHENA project has found a method of producing these cold anti-hydrogen atoms."

    If anyone is *really* interested I will post a linky to the whole thing that I wrote.

    Cheers

    Sam
     
  12. _rahoul

    _rahoul What's a Dremel?

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    ach du leiber!

    im amazed i can actually understand most of that, fascinating. I knew reading A brief history of time in 7th grade would prove to be useful
     
  13. phaSe

    phaSe What's a Dremel?

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    looks like it was a pretty nice report Uncle Psychosis :thumb:
    Anti-matter was indeed first postulated by Dirac, in that there was a solution to the Dirac Equation with positive charge, ie a positron.

    I believe the first anti-hydrogen was created at LEAR, which as you say has 'hot' or had lots of energy. At ATHENA cold antihydrogen was created so that spectroscopy could be done on the anti-particles to test CPT. As far as i know, they didnt actually do the spectroscopy, just showed that it would be possible as creating cold anti-hydrogen is possible.

    CPT, or charge, parity and time, means that, as Uncle Psycosis said, an antiparticle (opposite charge), that is a mirror-image (opposite parity), and going backwards through time (opposite time) should behave just the same as a real particle going forwards through time. Just reversing one (generally) doesnt make the universe look the same. (Just CP symmetry is generally ok, but not in all cases.)

    I dont tend to talk much physics on forums because it usually degenerates to antimatter bombs, time travel and super-conducting everythings! :rolleyes:

    RoB
     
  14. jonesie

    jonesie What's a Dremel?

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    *feels pwned* :blush:
     
  15. savethegaywhales

    savethegaywhales What's a Dremel?

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    I'm still a high school student so a lot of this is over my head. Can anyone point me to a site where this is explained well and correctly? Would appreciate it greatly.
     
  16. _rahoul

    _rahoul What's a Dremel?

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    http://livefromcern.web.cern.ch/livefromcern/antimatter/

    and heres a good explanation:

    This is the thread where i first posted this topic. A lot of discussion resulted out of it. (although most of it was crap)
    http://games.bigpond.com/pc/messageboards/subs/?action=show&id=2407830
     
  17. savethegaywhales

    savethegaywhales What's a Dremel?

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  18. Haddy

    Haddy World Domination

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    great...another potential weapon for us to blow the crap out eachother with....

    one step closer to star trek though =P
     
  19. Piratetaco

    Piratetaco is always right

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    just think.we may all be wearing skin tight one piece jumpsuits in a bit.
     
  20. Krikkit

    Krikkit All glory to the hypnotoad! Super Moderator

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    :sigh: Shame this always degenerates into Star-Trek when someone says the buzz-word (anti-matter). It's a fascinating subject really, we did quite a lot of it in AS-level physics this year, although we didn't study the ATHENA project or anything quite as new, although we did read about the previous project where they created the positrons and anti-protons at CERN. I didn't know that the boffins at CERN managed to move the project quite that far and actually create an anti-atom of something just yet. :D
     

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