Following closely on the heals of a major advance last November, when atoms of antimatter were trapped for the first time, the article, entitled “Confinement of Antihydrogen for 1000 Seconds”, details how scientists – including a team from Swansea University’s Department of Physics – have held some antihydrogen atoms for periods in excess of 15 minutes, in a manner which bodes well for future experiments aimed at studying the properties of this unique object.
Professor Mike Charlton, who leads the Swansea effort, said: “Our aim is to study antihydrogen, and make detailed comparisons with ordinary hydrogen. Whilst hydrogen is the most abundant element in the Universe, it seems that antihydrogen has only ever been formed in our experiments here on Earth. Why there was no antimatter left when the Universe became cold enough for atoms to form remains a great mystery – and one we hope to shed some light upon.”
The Swansea team – Professor Mike Charlton, Dr Niels Madsen, Dr Dirk Peter van der Werf and Dr Stefan Eriksson – are an important part of the collaborative ALPHA (Anti-hydrogen Laser PHysics Apparatus) project at CERN, the European Organisation for Nuclear Research, in Geneva. The project also involves physicists from the University of Liverpool, led by Professor Paul Nolan. The work is supported by the Engineering and Physical Sciences Research Council (EPSRC).
Controlled production of antihydrogen atoms in the laboratory has been possible for nearly a decade, when the ATHENA project made its first breakthrough. Swansea University physicists were also major players in ATHENA, the first experiment to produce copious amounts of cold antihydrogen, which was also based at CERN. However, all of these anti-atoms were quickly annihilated when they come into contact with matter. This has now changed with the latest ALPHA breakthrough. Nonetheless, painstaking preparation of the antiparticles is necessary to trap antihydrogen as the state-of-the-art ALPHA apparatus can only hold atoms with an energy a 100 billion times lower than that of the particles delivered by CERN.
“This latest development is a huge step towards measurements on antihydrogen and we are planning first experiments for later in the year,” said Swansea University Physicist Dr Niels Madsen, who is currently on sabbatical at CERN after winning a prestigious Royal Society Leverhulme Trust Senior Research Fellowship. “We have increased the efficiency with which we trap the antihydrogen atoms AND held onto some of them for long periods, already increasing our capability several thousand times over what we reported last November”, he added.