Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Molecules of positronium observed in the laboratory for the first time

Research by UCR physicists could help the development of gamma-ray lasers, explain how matter came to dominate the universe

Physicists at UC Riverside have created molecular positronium, an entirely new object in the laboratory. Briefly stable, each molecule is made up of a pair of electrons and a pair of their antiparticles, called positrons.

The research paves the way for studying multi-positronium interactions – useful for generating coherent gamma radiation – and could one day help develop fusion power generation as well as directed energy weapons such as gamma-ray lasers. It also could help explain how the observable universe ended up with so much more matter than “antimatter.”

Study results appear in the Sept. 13 issue of Nature.

The researchers made the positronium molecules by firing intense bursts of positrons into a thin film of porous silica, which is the chemical name for the mineral quartz. Upon slowing down in silica, the positrons were captured by ordinary electrons to form positronium atoms.

Positronium atoms, by nature, are extremely short-lived. But those positronium atoms that stuck to the internal pore surfaces of silica, the way dirt particles might cling to the inside surface of the holes in a sponge, lived long enough to interact with one another to form molecules of positronium, the physicists found.

“Silica acts in effect like a useful cage, trapping positronium atoms,” said David Cassidy, the lead author of the research paper and an assistant researcher working in the laboratory of Allen Mills, a professor of physics, the research paper’s coauthor. “This is the first step in our experiments. What we hope to achieve next is to get many more of the positronium atoms to interact simultaneously with one another – not just two positronium atoms at a time.”

When an electron meets a positron, their mutual annihilation may ensue or positronium, a briefly stable, hydrogen-like atom, may be formed. The stability of a positronium atom is threatened again when the atom collides with another positronium atom. Such a collision of two positronium atoms can result in their annihilation, accompanied by the production of a powerful and energetic type of electromagnetic radiation called gamma radiation, or the creation of a molecule of positronium, the kind Cassidy and Mills observed in their lab.

“Their research is giving us new ways to understand matter and antimatter,” said Clifford M. Surko, a professor of physics at UC San Diego, who was not involved in the research. “It also provides novel techniques to create even larger collections of antimatter that will likely lead to new science and, potentially, to important new technologies.”

Matter, the “stuff” that every known object is made of, and antimatter cannot co-exist close to each other for more than a very small measure of time because they annihilate each other to release enormous amounts of energy in the form of gamma radiation. The apparent asymmetry of matter and antimatter in the visible universe is an unsolved problem in physics.

Currently, antimatter finds use in medicine where it helps identify diseases with the Positron Emission Tomography or PET scan.

Cassidy and Mills plan to work next on using a more intense positron source to generate a “Bose-Einstein condensate” of positronium – a collection of positronium atoms that are in the same quantum state, allowing for more interactions and gamma radiation. According to them, such a condensate would be necessary for the development of a gamma-ray laser.

Iqbal Pittalwala | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht A new kind of quantum bits in two dimensions
19.03.2018 | Vienna University of Technology

nachricht 'Frequency combs' ID chemicals within the mid-infrared spectral region
16.03.2018 | American Institute of Physics

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

A new kind of quantum bits in two dimensions

19.03.2018 | Physics and Astronomy

Scientists have a new way to gauge the growth of nanowires

19.03.2018 | Materials Sciences

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Science & Research
Overview of more VideoLinks >>>