Gamma-ray laser moves a step closer to reality
Hollow spherical bubbles filled with gas made from positronium atoms (a key component of a gamma laser) are stable in liquid helium, according to a new study.
When an electron collides with its antiparticle, the positron, they can annihilate, creating powerful electromagnetic radiation called gamma radiation, or form an exotic hydrogen-like bound state atom called positronium. To create a gamma laser beam, positronium must be in a Bose-Einstein condensate state to allow more interactions and amplify the radiation.
Calculations by physicist Allen Mills of the University of California at Riverside show that a bubble of millions of such exotic atoms in liquid helium will exist as a Bose-Einstein condensate of matter-antimatter and will be six times denser than air..
Helium becomes liquid only at extremely low temperatures and has a negative affinity for positronium. Bubbles are formed in it and exist for a long time due to the fact that helium repels positronium.
Mills says his lab is already tuning a beam of antimatter in search of the predicted exotic bubbles. The closest experimental results can be the observation of the tunneling of positronium through the graphene sheet, as well as the formation of a laser beam of positronium atoms.
Gamma laser could be used for medical imaging, spacecraft, quantum computers and cancer treatment.
We also previously reported that scientists found a new way to measure gravity using pairs of atoms.
text: Ilya Bauer, photo: University of California, Riverside