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Announcements Science

NC State Creates Most Powerful Positron Beam Ever 214

eldavojohn writes "A fairly large breakthrough took place earlier this month with the most powerful man-made antimatter electron beam ever being created at North Carolina State University. Professor Hawari who worked on the project explains its benefits: 'The idea here is that if we create this intense beam of antimatter electrons — the complete opposite of the electron, basically — we can then use them in investigating and understanding the new types of materials being used in many applications.'"
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NC State Creates Most Powerful Positron Beam Ever

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  • by burtosis ( 1124179 ) on Monday October 22, 2007 @06:33PM (#21078425)
    http://positrons.physics.lsa.umich.edu/nanopos/Publications/Reprints/Annual%20Rev%20Materials%20Research%20PAS%202006.pdf [umich.edu] Used mostly for characterizing porus materials. Fun read if you find materials or nuclear science interesting, however perhaps too boring to put forth as informations in TFA.
  • by Derling Whirvish ( 636322 ) on Monday October 22, 2007 @06:36PM (#21078465) Journal
    So if you shot a powerful positron beam at something and also shot a powerful electron beam at it also, would you have a continuous antimatter explosion at the crossover point?
  • Useless without... (Score:3, Interesting)

    by clarkcox3 ( 194009 ) <slashdot@clarkcox.com> on Monday October 22, 2007 @07:21PM (#21078955) Homepage
    OK, this article is useless without some mention of how powerful this beam is. They say that the reactor itself puts out 5MW, but nothing of the beam itself.
  • by Ungrounded Lightning ( 62228 ) on Monday October 22, 2007 @07:34PM (#21079075) Journal
    But with an electron beam ... you could potentially create a floating point of light?

    Naw. It would have to hit something to glow. And it wouldn't be much of a beam with an acceleration voltage in the single-digit volts needed to produce visible light when the electrons slam into something.

    As for trying to make a middle-of-the-air display by intersecting electron and positron beams: While half-MeV gamma-ray photons count as "light" they don't count as "visible light" (unless the light is really bright and an unfocused, all-over-the-retina, dying-cell sensation counts as "visible"). They're more than 100,000 times as "ultra" as "ultra-violet".
  • by Anonymous Coward on Monday October 22, 2007 @07:47PM (#21079189)
    I don't see how this post is insightful -- it doesn't say anything factual. I have been around a research reactor at Cornell, before they closed it (in 2001 I think they finally did). They showed us how it operates. We (the students in the Nuclear Engineering class) were in the control room when they let it go critical. Those reactors are a completely different design than power-generating or breeder reactors. By design they cannot go critical for more than a millisecond or so -- the nuclear reaction shuts itself down due to the nature of the neutron crossection of Uranium. The reactor at Cornell was an open reactor -- it was at the bottom of a pool of water and one could look at it from above -- it glowed nice and blue. Also those are reactors that run on Uranium that is only weakly enriched and cannot be used for weapons.
  • Not Quite (Score:5, Interesting)

    by el_munkie ( 145510 ) on Monday October 22, 2007 @08:57PM (#21079749)
    I took a class that involved going to the University of Texas' learning reactor. To get in the front door, one had to get buzzed in by someone behind a desk. To get to the controls or the reactor, one had to get past several security measures and some very solid metal doors. The first time the prof took us back there, he warned us that the door could only be open for 3 minutes. I asked him what happened if that time was exceeded, and he said that a SWAT team would be there within five.
  • by rcani ( 831229 ) on Tuesday October 23, 2007 @12:44AM (#21081359)
    Honestly, stealing reactor materials from the Pulstar probably wouldn't be that hard. When you think about the amount of time spent planning the 9/11 attacks, a couple of semesters to become a reactor operator wouldn't be that big a deal. or there are others experiments going on in the reactor bay, so I assume the people running those experiments have access. Once you have physical access to the reactor you wouldn't need weapons or SCUBA gear, particularly assuming you don't mind death from radiation poisoning/cancer. just pull the rods out and put them in a box. then stroll off campus.

    (lawyer note: I don't recommend this, you will probably get caught and spend the rest of your life in jail, plus it's just plain a bad idea)
  • by LinearBob ( 258695 ) on Tuesday October 23, 2007 @12:46AM (#21081371)
    Thank you for your kind remarks.

    I used to work at SLAC, and I got to know something about how the whole machine worked and what we (as a member of the team who made it work) were doing. You are 100% correct about beer and bubble chambers. At one time SLAC had a huge bubble chamber filled with liquid hydrogen (as I recall, I could be wrong). They also had a huge cloud chamber, and even a very large spark chamber, and giant solenoid magnets around those chambers, to make charged particles leave curved tracks. Back then, they photographed each pulse of the accelerator as seen in the bubble chamber, the cloud chamber, or the spark chamber (something like 5 to 10 pulses per second) on black and white movie film. They then had teams of people studying those films, frame by frame, looking for "interesting events". I'm sure the folks doing this visual analysis rapidly developed eye strain. I'm also sure the development of the particle detector (as represented by SLD) was a great improvement, both because the experimental machinery could run faster, and because computers could do the data analysis much faster and more accurately than people.

    Although I am no longer working for SLAC, I always thought SLAC was a great place to work. There was so much history there that I could see and touch, and I sometimes got to talk with the people who were there when exciting discoveries were made. SLAC was where quarks were first observed in the form of three small (but hard) pits in the middle of a large squishy thing called a proton. They made this discovery by studying the scattering of some high speed electrons shot into a tank of liquid hydrogen. They then shot the same high speed electron beam into a tank of liquid deuterium. Deuterium has one proton and one neutron in its nucleus. To derive what the neutron looked like, they subtracted out what the scattering effect was from liquid hydrogen (which has only a proton in it's nucleus) and from that concluded that neutrons also were large squishy things with three hard pits in the middle, just like protons.

    SLAC and the team that performed this high speed electron scattering experiment won a Nobel Prize for their work.

    SLAC is also where the quark theory was tested in one of the first storage rings called SPEAR, earning SLAC another Nobel Prize. The Tau particle was found there, too, although the tau had been recorded but not recognized in other places. The discovery of the tau earned SLAC their third Nobel Prize.

    While I worked there, my email and newsgroup signature line was, "Nobel Prizes R Us!"
  • Re:Obligatry (Score:3, Interesting)

    by love-blood-rhetoric ( 880992 ) <alyndaker@@@gmail...com> on Tuesday October 23, 2007 @08:21AM (#21083367)
    So, I would really like to know the characteristics of this beam. Are they creating and destroying positrons with the highest flux in the world? Here at CHESS [cornell.edu], we run a beam of positrons as well as electrons in CESR with an energy of 5GeV @ 240mA. Granted they are recirculating through the ring, but the instantaneous power of this is [nearly and for effect] 1.21 GW. However, it if one were to direct this at a target, you would destroy the entire beam in nanoseconds. The sustained power would be that which the gun and linac can provide which is still huge (10's of MeV @ 10's of mA), albeit for 10's of minutes before the gun must cool.

    I do wish the article gave more information. If someone has some, please post it.

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