First controlled production of atomic antimatter

Physicists have just achieved the world’s first controlled production of anti-hydrogen atoms, the crucial first step towards precision studies of its properties.

This achievement has opened up the potential to cool, trap and study anti-atoms.

A team from the University of Wales – Swansea, led by Professor Michael Charlton, played a key role in this major breakthrough as part of an international consortium, ATHENA. The Swindon based Engineering and Physical Sciences Research Council provided funding for the Swansea team of £1.2M over the past 6 years.

“This is a milestone that has opened up new horizons, to enable scientists to study symmetry in nature and explore the fundamental laws of physics which govern the universe, said Prof Charlton. “We are also asking the related question ‘where has all the antimatter gone?’ Today our Universe appears to consist entirely of matter: but we know that equal amounts of matter and antimatter were created in the Big Bang.”

The first step in producing anti-atoms is to confine positive and negative antiparticles in traps at very low temperature. Then they are slowly allowed to react in ultra-high vacuum, which is essential, as the antiparticles will annihilate when they meet normal matter. The result of the interaction is the first and simplest of anti-atoms, anti-hydrogen.

The breakthrough is timely as it coincides with the centenary of the birth of Paul Dirac, who first predicted in 1930, that every particle has an equivalent antiparticle. The British physicists at Swansea played a vital role in the project by making the trap for the positively charged antiparticles, known as positrons.

Professor Charlton acknowledges the support he has received for this research, “EPSRC took a chance in funding this highly speculative project in 1996. This acted as a catalyst, which persuaded other countries to contribute to the ATHENA consortium.”