Antimatter trapped and studied for first time
By Ben Coxworth
November 18, 2010
An international collaboration of 15 research institutions have produced and trapped antimatter atoms for the first time ever. The feat was part of the ALPHA experiment, which is being conducted at Switzerland’s CERN particle physics laboratory. It could be a step towards answering one the biggest cosmological questions of all time.
Using CERN’s one-of-a-kind low-energy antiproton decelerator, scientists were able to produce antihydrogen atoms. Whereas hydrogen atoms consist of one proton orbited by one electron, the antihydrogen atoms consisted of an antiproton orbited by a positron (or “anti-electron”). Nine man-made antihydrogen atoms were first created at CERN in 1995, then additional experiments in 2002 showed that it was possible to create them in larger numbers. What’s unique about this latest achievement is the fact that the scientists were able to store the atoms long enough to study them – a whopping almost-two-tenths of a second.
Anyone who’s read Angels and Demons will know that storing antimatter is a tricky process. Due to the fact that matter and antimatter contain opposite charges, the two will annihilate (i.e: destroy one another) if they touch. To overcome this problem, at least temporarily, the scientists used a Minimum Magnetic Field Trap. This bottle-shaped device incorporates strong electric and magnetic fields to keep the antimatter atoms from coming into contact with its walls. Using this technology, a total of 38 atoms were observed.
According to the Big Bang theory, equal amounts of matter and antimatter should have been created when the universe was formed. What puzzles scientists now is the question of where all that antimatter disappeared to.
“For reasons that no one yet understands, nature ruled out antimatter,” said Jeffrey Hangst of Aarhus University, Denmark, spokesman for the ALPHA collaboration. “It is thus very rewarding, and a bit overwhelming, to look at the ALPHA device and know that it contains stable, neutral atoms of antimatter... This inspires us to work that much harder to see if antimatter holds some secret.”
The research was just published in the journal Nature.
All images courtesy of CERN, except where noted.