image and text from berkeley.edu"Physicists working at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, have succeeded in trapping antihydrogen — the antimatter equivalent of the hydrogen atom — a milestone that could soon lead to experiments on a form of matter that disappeared mysteriously shortly after the birth of the universe 14 billion years ago.
An octupole magnet was critical to trapping antihydrogen atoms. A simple octupole magnetic field is produced by eight bar magnets in a plane with their north and south poles arrayed radially to create a magnetic minimum at the center. The antihydrogen atom is trapped in the center because of its magnetic moment, which itself is equivalent to a tiny bar magnet. The bar magnets above and below the octupole plane in this artist's rendition represent the mirror magnets that keep the atoms from squirting out the ends of the trap. (Katie Bertsche)The first artificially produced low energy antihydrogen atoms — consisting of a positron, or antimatter electron, orbiting an antiproton nucleus — were created at CERN in 2002, but until now the atoms have struck normal matter and annihilated in a flash of gamma-rays within microseconds of creation."