Prof Charlton said: "Our anti-hydrogen
measurement was an historic achievement in anti-matter science.
Walter Oelert of the Juelich Institute for Nuclear Physics Research in Germany and his German and Italian colleagues reported that they created the 11 atoms of anti-hydrogen during a three-week experiment at CERN last September, but withheld the news until they and independent experts had thoroughly checked their results, which will be published in a forthcoming issue of the journal Physical Review B.
We're absolutely sure now," he said in an interview, "and the experiment shows without doubt that anti-hydrogen can exist.
Prof Charlton said: "Our anti-hydrogen measurements are an historic achievement in anti-matter science.
The aim of the ALPHA experiment at Cern, which brings together scientists from eight countries including the UK, USA, Canada and Japan, is detailed studies of anti-hydrogen atoms - the anti-matter counterpart of the simplest atom, hydrogen.
That is a significant improvement on past efforts to create anti-matter, which have managed to generate some anti-hydrogen atoms, but they blinked out of existence almost as soon as they were created.
It is the longest time period that anti-hydrogen has been captured, and a major advance since last November, when atoms of anti-matter were trapped for the first time.
Previous attempts to create antimatter have only managed to generate anti-hydrogen
atoms so short-lived that they hardly exist.
You would need 10,000,000,000,000,000,000 times that amount to have enough anti-hydrogen
gas to fill a toy balloon.
Mike Charlton, a physics professor at University of Wales, Swansea, has been mentioned in dispatches by the Engineering and Physical Research Council for helping to create anti-hydrogen
atoms so they can be studied.
The task the Welsh researchers are now involved in is helping to examine the tiny amount of anti-hydrogen
produced and to compare it with normal hydrogen.
2m Antimatter Decelerator to produce the simplest anti-atom, anti-hydrogen
, to help scientists around the world probe the differences between matter and anti-matter and shed light on how the universe started life.