ALPHA Collaboration
Antihydrogen has, like many atoms and especially hydrogen, a small magnetic dipole moment. A dipole moment is another way of saying that the atom behaves a bit as if it was a tiny magnet with a north and a south pole. Normally such small magnets are attracted to other magnets. However, some atoms in some states behave such that they are repelled by magnetic fields. This means that the atoms could possibly be trapped in space by making a minimum of the magnetic field. ALPHA is trying to do just that with antihydrogen. By a clever arrangement of magnets, ALPHA has a so-called magnetic minimum trap, in which antihydrogen may be trapped.