Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

When matter and antimatter collide

27.12.2010
Antimatter, a substance that often features in science fiction, is routinely created at the CERN particle physics laboratory in Geneva, Switzerland, to provide us with a better understanding of atoms and molecules.

Now, RIKEN scientists, as part of a collaborative team with researchers from Denmark, Japan, the United Kingdom and Hungary, have shown that antiprotons—particles with the same mass as a proton but negatively charged—collide with molecules in a very different way from their interaction with atoms1. The result sets an important benchmark for testing future atomic-collision theories.

RIKEN scientist Yasunori Yamazaki explains that to assess such collisions: “We shot the simplest negatively charged particles, slow antiprotons, at the simplest molecular target, molecular hydrogen.” Slow antiprotons are a unique probe of atoms and molecules because their negative charge does not attract electrons—thereby simplifying theoretical modelling. Further, slower projectile speeds mean longer-lasting, stronger interactions and avoid the need for complicated relativistic calculations.

The scientists at CERN created antiprotons by firing a beam of high-speed protons into a block of the metal iridium. Then, in a facility known as the Antiproton Decelerator, they used magnets to focus the antiprotons before applying strong electric fields to slow them down to approximately 10% of the speed of light. Yamazaki and his colleagues trapped and cooled these antiprotons to 0.01% of the velocity of light before accelerating them one by one to the desired velocity (Fig. 1). They then slammed antiprotons into a gas of molecular deuterium—a pair of bound hydrogen atoms each with a nucleus comprising one proton and one neutron—and used sensitive equipment to detect the remnants of the collision.

Yamazaki and the team found that the likelihood of the ionization of the deuterium molecules scales linearly with the antiproton velocity. This is contrary to what is expected for the atomic target, hydrogen. “This was a big surprise, and it infers that our understanding of atomic collision dynamics, even at a qualitative level, is still in its infancy,” says Yamazaki. The team suggests that molecular targets provide a mechanism for suppressing the ionization process. As an antiproton approaches one of the protons in the molecule, the presence of the second proton shifts the orbiting electron cloud. The slower the antiproton, the more time the electron has to adjust, and hence the smaller the chance of ionization.

The team now hopes to investigate how ionization depends on the antiproton–target distance and the orientation at the moment of collision.

The corresponding author for this highlight is based at the Atomic Physics Laboratory, RIKEN Advanced Science Institute.

Journal information

Knudsen, H., Torii, H.A., Charlton, M., Enomoto, Y., Georgescu, I., Hunniford, C.A., Kim, C.H., Kanai, Y., Kristiansen, H.-P.E., Kuroda, N., et al. Target structure induced suppression of the ionization cross section for very low energy antiproton–hydrogen collisions. Physical Review Letters 105, 213201 (2010).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>