Turning Light into Matter via Photon-Photon Collision

Here’s an interesting piece of scientific news that comes via Phys.org.

Scientists at the Imperial College London think they have discovered a method that can turn light into matter — a concept that was theorized in in 1934 by Breit and Wheeler, but has never been experimentally demonstrated. Physicists Oliver Pike, Steve Rose and others believe that the technology needed to carry out a demonstration of this process is now available using a collider, and they came up with the idea as they were working in the field of fusion physics. The experiment is described as follows in the article:

The collider experiment that the scientists have proposed involves two key steps. First, the scientists would use an extremely powerful high-intensity laser to speed up electrons to just below the speed of light. They would then fire these electrons into a slab of gold to create a beam of photons a billion times more energetic than visible light.

The next stage of the experiment involves a tiny gold can called a hohlraum (German for ’empty room’). Scientists would fire a high-energy laser at the inner surface of this gold can, to create a thermal radiation field, generating light similar to the light emitted by stars.

They would then direct the photon beam from the first stage of the experiment through the centre of the can, causing the photons from the two sources to collide and form electrons and positrons. It would then be possible to detect the formation of the electrons and positrons when they exited the can.

For a light-to-matter process demonstrable experimentally would of course be a remarkable scientific breakthrough — and it will be interesting to follow progress in this area. The full report of their research can be found in Nature Photonics here (full access is only available for paid subscribers)