Breit–Wheeler process as described by Gregory Breit and John A. Wheeler in 1934, is the simplest mechanism ever predicted by which pure light can be transformed into matter. They suggested that conversion could be possible by smashing only two particles of light (photons), which would then result in the formation of an electron and a positron.
Although the process sounded theoretically possible, it has never been experimented. However, the new research at London’s Imperial College has shed some light on the process which establishes the possibility to convert light into matter (and even E into mc2). The experiment involves two different stages.
- In order to achieve collisions in a photon-photon collider, the scientists would use an extremely powerful high-intensity laser to speed up electrons, but slightly less than the speed of light. They would then fire the electrons into a slab of gold to create a beam of photons a billion times more powerful than normal visible light.
- It would also involve a tiny gold can called a hohlraum, which would be treated by high-energy laser at its inner surface. This would then create a thermal radiation field, generating light similar to the light emitted by stars.
Further, the photon beam achieved in the first stage would then be directed through the center of the can, causing the photons from the two sources to collide and form electrons and positrons. This would detect the formation of the electrons and positrons when the photons left the can. “Despite all physicists accepting the theory to be true, when Breit and Wheeler first proposed the theory, they said that they never expected it be shown in the laboratory. Today, nearly 80 years later, we prove them wrong,” said Steve Rose from the Department of Physics at Imperial College London.