Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New research by UCR physicists could help develop gamma ray lasers and produce fusion power

03.05.2010
Researchers isolate collection of “pure” or spin polarized positronium atoms for the first time

Positronium is a short-lived system in which an electron and its anti-particle are bound together.

In 2007, physicists at the University of California, Riverside created molecular positronium, a brand-new substance, in the laboratory. Now they have succeeded in isolating for the first time a sample of spin polarized positronium atoms.

Study results appear this week in the journal Physical Review Letters.

Spin is a fundamental and intrinsic property of an electron, and refers to the electron's angular momentum. Spin polarized atoms are atoms that are all in the same spin state. A collection of spin polarized positronium atoms is needed to make a special form of matter, called the Bose-Einstein condensate (BEC). The BEC, predicted in 1924 and created in 1995, allows scientists to study atoms in a unique manner.

"We achieved our result by increasing the density of the positronium atoms in our lab experiment," 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. "At such a high density, positronium atoms get annihilated simply by interacting with each other. But it turns out that not all the positronium atoms get annihilated under these conditions."

Cassidy explained that positronium atoms come in two types – say, an up type and a down type. The positronium atoms are only annihilated when an up type meets a down type. Two atoms of the same type do not affect each other.

"So if you have 50 percent ups and 50 percent downs and you squeeze them all together they will totally annihilate and turn into gamma rays," he said. "But if you have, for example, about 66 percent ups and 33 percent downs, then only half of the ups will be destroyed. You will get a load of gamma rays – but in the end you will be left with only one type of atom – in this case, up atoms.

"This is an important development for making the BEC," Cassidy said, "because you have effectively purified your sample of positronium. And you need a pure collection of spin aligned atoms to make the BEC."

When atoms are in the BEC state, they are essentially stopped (or they move extremely slowly), facilitating their study. Non-BEC atoms on the other hand whiz around at very high speeds, making them harder to study.

"There are fundamental processes that can be looked at in new ways when you have matter in the BEC state," Mills said. "Having Bose-condensed atoms makes it easier to probe the way they interact under certain conditions. Moreover, to have motionless positronium atoms is an important aspect for making something called a gamma ray laser, which could have military and numerous scientific applications."

According to Mills and Cassidy, the new research could lead also to the production of fusion power, which is power generated by nuclear fusion reactions.

"The eventual production of a positronium condensate could help us understand why the universe is made of matter and not antimatter or just pure energy," Cassidy said. "It could also one day help us measure the gravitational interaction of antimatter with matter. At present, nobody knows for sure if antimatter falls up or down."

The National Science Foundation and the U.S. Air Force supported the research.

Cassidy and Mills were joined in the study by Vincent Meligne, a graduate student in Mills's lab.

The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 18,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.

A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Physics and Astronomy:

nachricht NASA's SDO sees partial eclipse in space
29.05.2017 | NASA/Goddard Space Flight Center

nachricht Strathclyde-led research develops world's highest gain high-power laser amplifier
29.05.2017 | University of Strathclyde

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: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>