Antihydrogen trapped for 1000 seconds

A new experiment from the ALPHA collaboration, based at CERN, has created and trapped antihydrogen atoms for 1000 seconds, 6000 times longer than their previous attempts which trapped antihydrogen for 172 ms. Having antihydrogen trapped for this period allows the possibility of studying fundamental properties of antimatter in detail including the possibility of how it is affected by gravity. Although antimatter is believed to fall under gravity, that needs to be checked along with the other basic principles of physics.

The magnetic trap and detector used to trap antihydrogen for 1000 seconds.

The magnetic trap and detector used to trap antihydrogen for 1000 seconds.

The antihydrogen is first created by making antiprotons from equipment that was previously used to run the Large Electron Positron (LEP) collider at CERN. Those are mixed with a beam of positrons for about 1 second inside a magnetic trap.

Some of the antiprotons bind with the positrons to form antihydrogen, which is believed to be stable, just as hydrogen is. Most of the antihydrogen escapes the trap or annihilates by hitting the trap walls. Any leftover antiprotons or positrons are cleared out of the way with an electric field so there is just antihydrogen left. After this process, the physicists have about a few tens of thousands of antiatoms in their traps. Over time they escape the trap or are allowed to escape and the annihilations are recorded with a particle physics detector that surrounds the trap.

Theoretical analysis suggests that antiatoms could be trapped from anywhere between 300 and 100,000 seconds, so the measurement is consistent with the predictions. However, it also opens up the possibility that the antihydrogen could be trapped for considerably longer than 1000 seconds. Regular matter atoms can be trapped for times as long as 10-30 minutes.

Ref: arXiv:1104.4982

Posted April 28th, 2011 in Uncategorized.

One comment:

  1. mehmet emin ozel:

    how do we know that what is left is antihydrogen rather than hydrogen? do they have different energy levels? or do they emit anti-photons?

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