The equivalence of matter and energy was first enshrined in the laws of physics by the famous E=mc2 equation, and since then we have been using it to get energy out of matter in nuclear power plants.
Now, Russian researchers have looked into the opposite effect. By using a powerful laser, they plan to create antimatter from light. The team has produce detailed calculations on how to use ultrahigh-intensity lasers to create electrons and positrons.
While positrons are one of the simplest antimatter particles, being just the opposite of the electron, it is difficult to create many of them with very high energy. This might be the right way to do it.
The team, from the Institute of Applied Physics of the Russian Academy of Sciences, has worked on a specific prediction of a theory called quantum electrodynamics (QED), which describes how matter and light interact at the quantum level.
The prediction states that given a very strong electric field, it is possible to form electron-positron pairs. In a simplistic way, the field turns the virtual particles that inhabit the vacuum into real particles we can observe.
In a paper, published in Physics of Plasma, the team worked out how to use this idea to create a QED cascade – a self-sustaining emission of electron-positron pairs.
“Think of it as a chain reaction in which each chain link consists of sequential processes,” Igor Kostyukov said in a statement. “It begins with acceleration of electrons and positrons within the laser field. This is followed by emission of high-energy photons by the accelerated electrons and positrons. Then, the decay of high-energy photons produces electron-positron pairs, which go on to new generations of cascade particles. A QED cascade leads to an avalanche-like production of electron-positron high-energy photon plasmas.”
The researchers simulated the interaction between some foil and very powerful laser pulses to create strong electric fields, much stronger than those found in atoms. They discovered that the modeled set up would create the QED cascade and a large number of positrons.
The researchers will continue to expand this simulation, trying to understand what would happen in more realistic and chaotic scenarios, which could potentially be turned into real-life applications for generating plasma.