New way to create antimatter

Physicists at the University of California, Riverside, USA, have discovered a new way to create positronium, a strange atom and only exist for a short time and the atom itself can help answer for what happened to antimatter in the universe, explaining why, what properties of antimatter helped to create the universe.

Positronium is made up of an electron and its own antimatter counterpart, positron. Positronium has applications in the development of more precise positron emission tomography, also called scanning (PET) and basic physics research.

Recently, antimatter has become a hot topic when scientists at CERN, the European nuclear research organization, trap the hydrogen atoms for more than 15 minutes. Until then, the presence of antiparticles was recorded only in parts of a second.

Physicists study at UC Riverside University, USA

In the lab at UC Riverside, USA, the first physicists exposed irradiated silicon samples to laser light. Next they implanted positrons on the surface of silicon. They discovered that the electron-emitting laser light then linked to the positrons to form positronium .

" With this method, a significant amount of positronium can be produced in a wide range of temperatures and is fully controllable," said David Cassidy, project scientist, assistant in the department. Physics and Astronomy, people are doing research with colleagues. " Other methods for making positronium from the surface require heating the sample at very high temperatures. Our method works at most temperature thresholds, including very low temperature thresholds ."

Cassidy explains that when positrons are implanted in materials, they can be trapped on the surface of the material, and will quickly find and destroy electrons.

" In the experiment, we found that laser surface irradiation before positrons hit electrons would enable positrons to leave the surface of the material and avoid electrons being destroyed by them. " , according to Allen Mills, Cassidy's professor of physics and astronomy, at the lab. " This is the way to make positronium, spontaneously, positronium is emitted from the surface of the material. Free Positronium lasts 200 times longer than the surface of the material, so it is easily detected. " .

The results are published in Physical Review Letters , issued July 15, 2011.

The researchers chose silicon in their tests because of their wide application in the field of electronics, solid, inexpensive and efficient.

" Indeed, at very low temperatures, Silicon is the best material to produce positronium, at least in short bursts ," Cassidy said.

The researcher's ultimate goal is to make accurate measurements on positronium to better understand its antimatter and properties, as well as to find ways to isolate it for longer periods of time.

Cassidy and Mills were invited to participate in the study by Professor Harry Tom, and chairman of the Physics and Astronomy Society, and Tomu H. Hisakado, a graduate student in Mills's lab.

In the near future, the team hopes to cool positronium to deliver energy under other experimental uses, and also create " Bose - Einstein condensate " for positronium - gather positronium atoms in the same quantum state. together.

" The creation of a Bose - Einstein's positronium will actually push the boundaries of what is possible in terms of true measurement, " Cassidy said. " Such measurements shed more light on the properties of antimatter and helped us probe why there is asymmetry between matter and antimatter in the universe ."

This research is funded by the National Science Foundation and the US Air Force Research Laboratory.