The University of California, Riverside physicists have found a new approach to generate positronium, an atom with a short lifespan, to help solve queries related to antimatter in the universe such as why nature preferred matter over antimatter when the universe was created.
Initially, the physicists irradiated silicon samples using laser light and embedded positrons on the silicon surface. They discovered that the laser light helps to release the silicon electrons that attach with the positrons to form positronium.
A scientist in the Department of Physics and Astronomy, David Cassidy, who conducted the research with co-workers, stated that using this method, it is possible to produce considerable quantities of positronium in a controlled manner and in a broad temperature range.. Heating to a very high temperature is not required, instead positronium may be created, even at low temperatures. According to Allen Mills, a physics and astronomy professor, the research shows that surface irradiation with laser just prior to arrival of positrons causes the emitting of electrons, which enables the positrons be released from the surface and not get destroyed. This is possible by the forming of positronium. Free positrons have a longer lifespan than surface positrons and are easy to identify. The results of the study will be published in the July 15 issue of Physical Review Letters. The physicists selected silicon as it is suitable for a wide range of applications including electronics. Moreover, silicon is strong, inexpensive and renders high-efficiency.
The researchers wanted to conduct accurate measurements on positronium to achieve an overall understanding of antimatter and its characteristics. They also wanted to know if positronium could be kept isolated for longer durations. The research team hopes to bring the positronium to reduced levels of energy emission for other experimental purposes and to develop a "Bose-Einstein condensate" for positronium.
Source: http://www.ucr.edu/