Spacecrafts powered by antimatter — the mirror image of the matter that our universe is made of — have been a common science-fiction trope for decades. As opposed to chemical fuels, several tons of which are needed to produce a substantive thrust, just milligrams of antimatter, which annihilates in a massive flash of energy when it comes in contact with matter, can power a manned mission to Mars.
The problem? Antimatter is dauntingly expensive to make, both in terms of the money and energy required. In 1999, NASA estimated that it may take up to $62.5 trillion to make just one gram of antihydrogen.
“If all the antimatter ever made by humans were annihilated at once, the energy produced wouldn’t even be enough to boil a cup of tea,” Diana Kwon wrote for Symmetry magazine last year.
Now, a team of researchers from the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) have figured out a way to manufacture antimatter in an efficient and cost-effective manner — by focussing high-powered laser pulses.
Their calculations, described in the latest issue of the journal Physics of Plasmas, are based on a concept called quantum electrodynamics (QED), which states that a strong electric field can convert matter-antimatter particles from a virtual state to a real one, where they are directly observable.
This, the researchers argue, can give rise to what is known as a QED cascade — a chain reaction of sorts that is yet to be observed in a laboratory.
“It begins with acceleration of electrons and positrons within the laser field,” co-author Igor Kostyukov from IAP RAS, said in a statement. “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 next step would be to use the calculations to actually carry out the process in a lab, which, if successful, could pave the way for the manufacture of cheap antimatter to power the spaceships of the not-so-distant future.
“It offers new insights into the properties of these types of interactions,” Kostyukov said. “More practical applications may include the development of advanced ideas for the laser-plasma sources of high-energy photons and positrons whose brilliance significantly exceeds that of the modern sources.”