Matter-antimatter molecule could pave way for ultra-powerful laser

Scientists at the University of California at Riverside have created molecular positronium, in which two positrons - antimatter siblings of electrons - are bound together by electrons, in the laboratory. This exotic molecule could also hold the clue to powerful gamma-ray lasers, they say.

London, Sept 19 : Scientists at the University of California at Riverside have created molecular positronium, in which two positrons - antimatter siblings of electrons - are bound together by electrons, in the laboratory. This exotic molecule could also hold the clue to powerful gamma-ray lasers, they say.

Electrons and positrons have equal and opposite charges, and can become bound together by their electrical attraction, just as a positively charged proton is orbited by an electron in ordinary hydrogen atoms.

In theory, positronium atoms - electron-positron pairs - should also be able to pair up to form molecules, just as two hydrogen atoms form H2, scientists say.

However, positronium atoms typically survive for less than a millionth of a second before they self-destruct, when isolated in vacuum.

The matter and antimatter annihilate each other, releasing a burst of energy in the form of gamma-rays, surviving for less than 150 nanoseconds.

Now, David Cassidy and Allen Mills at the University of California at Riverside, have finally made matter and antimatter remain stable.

First, they trapped positrons in a thin film of porous silica. Those positrons captured electrons to form positronium atoms, and the pattern of decay rates signalled that some of these atoms had teamed up to form a positronium molecule, denoted as Ps2.

The scientists say if positronium atoms could be forced to merge into a kind of "super-atom" condensate, it would decay in bursts of identical gamma rays, which could lead to gamma-ray lasers a million times more powerful than standard lasers.

"It's like comparing a chemical explosion with a nuclear explosion", said Cassidy.

The findings appear in the September issue of the New Scientist magazine.

ANI