Earlier this year, a research collaboration at CERN announced that it had created a few dozen atoms of antihydrogen, the antimatter equivalent of the more familiar hydrogen atoms. These anti-atoms were kept in existence for just under 200 milliseconds before they annihilated in collisions with the container walls. Now, the same team is back with the announcement that it has created hundreds of atoms of antihydrogen, some of which were kept around for over 15 minutes—long enough to start contemplating doing some serious science with them.
The trap used to catch the antihydrogen is the same one used in the last experiment. It uses superconducting magnets to keep the antiatoms away from the container walls, taking advantage of the tiny magnetic moment created by the spatial distance between the antiproton nucleus and the positron (antielectron) orbiting it. The differences are so tiny that the trap will only work if the antihydrogen has an energy of 50μeV (micro electron Volt), which makes for quite a challenge, since the antiprotons start the process at 3keV. The big increase in the number of trapped atoms has largely come about through better ways of slowing down and cooling the starting materials.