Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Thousands of cold anti-atoms produced at CERN

19.09.2002


An international team of physicists working at the Antiproton Decelerator (AD) facility at CERN has announced the first controlled production of large numbers of antihydrogen atoms at low energies. After mixing cold clouds of trapped positrons and antiprotons - the antiparticles of the familiar electron and proton - under closely monitored conditions, the ATHENA collaboration has identified antihydrogen atoms, formed when positrons bind together with antiprotons. The results are published online today by the journal Nature.



Says Professor Luciano Maiani, Director General of CERN, "The controlled production of antihydrogen observed in ATHENA is a great technological and scientific event. Even more so because ATHENA has produced antihydrogen in unexpectedly abundant quantities. I’d like also to recognise the contribution of the ATRAP experiment at CERN, which has pioneered the technology of trapping cold antiprotons and positrons, an essential step towards the present discovery."

The ATHENA experiment, which is run by a collaboration of 39 scientists from 9 different institutions worldwide, saw its first clear signals for antihydrogen in August - appropriately, the 100th anniversary of the birth of theorist Paul Dirac who predicted the existence of antimatter in the late 1920s. Says ATHENA spokesman, Rolf Landua,"The experiment is a major milestone in antimatter science and an important first step on the road to high precision comparisons of hydrogen and antihydrogen. Such measurements will provide information vital to our understanding of the Universe and in particular why nature has a preference for matter over antimatter."


The method ATHENA uses overcomes the two main limitations of previous experiments both at CERN and at Fermilab in the US, which produced only a few anti-atoms per day with velocities close to the speed of light. First, the AD takes high energy antiprotons and slows them down to the leisurely pace - by CERN’s standards - of a tenth of the speed of light. ATHENA then traps the antiprotons in a "cage" created by electromagnetic fields, and reduces their velocity further to a few millionths of the speed of light. The ATHENA apparatus captures and slows down - or "cools" - about 10,000 antiprotons from each bunch that arrives from the AD. The next stage is to mix them with about 75 million cold positrons. These are collected from the decay of a radioactive isotope, then caught within a second trap, and finally transferred to a third, "mixing" trap. It is here that cold - that is, very slow - antihydrogen atoms may form.

Central to ATHENA’s observations is the antihydrogen annihilation detector, which surrounds the trap where the antiprotons and positrons are mixed. When a positron and an antiproton bind together to form a neutral antihydrogen atom, it escapes the trapping electromagnetic fields, which are set up by metal electrodes. The anti-atom then strikes one of the electrodes, and the positron and antiproton annihilate separately, with an electron and a proton, respectively, in the surface of the metal.

The detector provides unambiguous evidence for antihydrogen by detecting the simultaneous annihilations of the antiproton and the positron, which occur at the same time and at the same position. ATHENA finds that several anti-atoms per second are produced on average during the procedure that mixes the positrons and antiprotons. So far the experiment has produced about 50,000 antihydrogen atoms.

ATHENA is one of two experiments set up to search for cold antihydrogen at the AD. Last year the ATRAP experiment was the first to use cold positrons to cool antiprotons. The experiment also successfully confined both ingredients of cold antihydrogen in the same trap structure. This simultaneous trapping of positrons and antiprotons was first demonstrated by TRAP, the predecessor to ATRAP, which operated on the Low Energy Antiproton Ring (LEAR) at CERN.

These breakthroughs at CERN are important milestones on the way to trapping, accumulating and cooling antihydrogen. Cold antihydrogen will be a new tool for precision studies in a broad range of science. Most fundamental will be the comparison of the interaction of hydrogen and antihydrogen with electromagnetic and gravitational fields. Any difference between matter and antimatter, however small, would have profound consequences for our fundamental understanding of Nature and the Universe.

Christine Sutton | alfa
Further information:
http://info.web.cern.ch/info/Press/

More articles from Physics and Astronomy:

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

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: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>