How to build a gamma-ray laser with antimatter hybrid

How to build a gamma-ray laser with antimatter hybrid - New Scientist: "HALF matter, half antimatter, positronium atoms teeter on the brink of annihilation. Now there's a way to make these unstable atoms survive much longer, a key step towards making a powerful gamma-ray laser.



All the elements in the periodic table consist of atoms with a nucleus of positively charged protons, orbited by the same number of negatively charged electrons. Positronium, symbol Ps, is different. It consists of an electron and a positron orbiting each other (see diagram). A positron is the electron's antimatter counterpart. Though positively charged like the proton, it has just 0.0005 times its mass. Positronium "atoms" survive less than a millionth of a second before the electron and positron annihilate in a burst of gamma rays."