Kewl, now we can realize "Angels and Demons" (coming to a theatre near you).
Terry On Fri, Nov 21, 2008 at 3:53 PM, Harry Veeder <[EMAIL PROTECTED]> wrote: > > > >> News >> Laser creates billions of antimatter particles >> Wednesday, 19 November 2008 >> Cosmos Online >> >> >> Positron factory: Physicist Hui Chen sets up targets for the anti- >> matter experiment at the LLNL laser facility. >> >> Credit: LLNL >> >> SYDNEY: By shooting a laser through a gold disc no bigger than the >> head of a drawing pin, physicists have created more than 100 >> billion particles of antimatter. >> The ability to create vast numbers of positrons in the laboratory >> opens the door to new avenues of research, they say. These include >> an understanding of the physics behind black holes, gamma ray >> bursts and why more matter than antimatter survived the Big Bang. >> >> Super-sized portion of positrons >> >> "We've detected far more antimatter than anyone else has ever >> measured in a laser experiment," said Hui Chen, a physicist at the >> Lawrence Livermore National Laboratory (LLNL) in California, U.S., >> who led the experiment. "We've demonstrated the creation of a >> significant number of positrons using a short-pulse laser." >> >> Previous experiments made smaller quantities of positrons using >> lasers and paper-thin targets - but new simulations showed that >> millimetre-thick gold could be a far more effective source, said >> the researchers, who report their finding this week at the American >> Physical Society's Division of Plasma Physics Meeting in Dallas, >> South Carolina. >> >> Chen and her team used a short, ultra-intense laser to irradiate a >> millimetre-thick gold target. >> >> In the experimental set-up, the laser ionises and accelerates >> electrons, which are driven right through the gold target. On their >> way, the electrons interact with the gold nuclei, which serve as a >> catalyst to create positrons. >> >> Electron's opposite number >> >> The electrons give off packets of pure energy, which decay into >> matter and antimatter, following the predictions of Einstein's >> famous equation that relates matter and energy. By concentrating >> the energy in space and time, the laser produces positrons more >> rapidly and in greater density than ever before in the laboratory. >> >> Positrons are the antimatter equivalent to the electron, and behave >> in a similar way, though they have the opposite charge (see, New >> twist to matter-antimatter mystery, Cosmos Online). >> >> The researchers took advantage of this property to detect them, by >> using a typical device to detect electrons (a spectrometer) and >> equipping it to detect particles with opposite polarity as well. >> >> "By creating this much antimatter, we can study in more detail >> whether antimatter really is just like matter, and perhaps gain >> more clues as to why the universe we see has more matter than >> antimatter," said LLNL team member Peter Beiersdorfer. >> >> >> "We've entered a new era," Beiersdorfer added. "Now, that we've >> looked for it, it's almost like it hit us right on the head. We >> envision a centre for antimatter research, using lasers as cheaper >> antimatter factories." >> >> Particles of antimatter are almost immediately annihilated by >> contact with normal matter, and converted to pure energy in the >> form of gamma rays. >> >> There is considerable speculation as to why the observable universe >> appears to be almost entirely matter, whether other universes could >> be almost entirely antimatter, and what might be possible if >> antimatter could be harnessed. >> >> Product of energetic celestial events >> >> Normal matter and antimatter are thought to have been in balance in >> the very early universe, but, due to a mysterious 'asymmetry', the >> antimatter decayed or was annihilated, and today very little remains. >> >> Over the years, physicists had theorised about antimatter, but it >> wasn't confirmed to exist experimentally until 1932. >> >> High-energy cosmic rays impacting Earth's atmosphere produce minute >> quantities of antimatter in the resulting jets, and physicists have >> learned to produce modest amounts of anti-matter using traditional >> particle accelerators and smaller laser set-ups in the lab. >> >> Antimatter may also be churned our in regions like the centre of >> the Milky Way and other galaxies, where very energetic celestial >> events occur. The presence of the resulting antimatter is >> detectable by the gamma rays produced when positrons are destroyed >> when they come into contact with nearby matter. >> >> ### >> With the Lawrence Livermore National Laboratory. >> >> >> [Non-text portions of this message have been removed] > >
