Conference Proceeding (refereed)

How long antihydrogen atoms linger in the ALPHA magnetic trap is an important characteristic of the ALPHA apparatus. The initial trapping experiments in 2010 (Andresen Nature 468, 673–676, 2010) were conducted with 38 detected antiatoms confined for 172 ms and in 2011 (Andresen Nature Phys. 7, 558–564, 2011) with seven for 1000 s.

Andrea Capra & ALPHA Collaboration

Article for Kvant: The Search for Antigravity

One of our members, Peter Granum, has written an outreach article for the journal of the Danish Physics and Astronomy Society KVANT.

Written Outreach
Outreach Article
Outreach Article
Written Outreach
Conference Proceeding (refereed)
The ALPHA experiment at CERN is designed to produce and trap antihydrogen to the purpose of making a precise comparison with hydrogen. The basic technique consists of driving an antihydrogen resonance which will cause the antiatom to leave the trap and annihilate. [...]

Andrea Capra for the ALPHA Collaboration

Student
Logo of Marquette University

Manipulation of antiprotons, positrons and other charged particles

In ALPHA, charged particles are trapped using a Penning-Malmberg trap. The most commonly trapped particles in our trap are the antiproton and the positron - the two ingredients to produce antihydrogen. Antihydrogen is electrically neutral, so it cannot be confined with the electric fields used to confine the charged positrons and antiprotons. Instead we use an ‘Ioffe-Pritchard trap’.

Diagnostic Tools

With the exception of modes, presently we can only detect antimatter in our apparatus by destructive methods (we either need to splat our particles onto a detector surface or annihilate the antimatter into the trap wall). While working with antimatter makes almost everything very difficult, fortunately detection is often very efficient.

We either detect the charge of particles in our apparatus (Faraday Cup, MCP, temperature measurements), or the annihilation products. When antimatter comes in contact with matter, it annihilates. This annihilation releases lots of energy and subatomic particles. These products are then detected either with the Plastic Scintillators, TPC, SVD.