Faller antimaterie oppover?

An article [in Norwegian] by our PhD student Helga Margrete Holmestad on the AEgIS experiment at CERN. Aftenposten is one of the largest newpapers in Norway.

Crowdcrafting… ou la science citoyenne

CQFD is a radio program that presents science news via the national broadcaster RTS.
Today's radio program [in French] focuses on crowdcrafting, using two examples: the AEgIS (public science project), and a satellite image crowdcrafting project, also run from CERN.

A moiré deflectometer for antimatter

The AEgIS collaboration at CERN (an international consortium of 25 institutions) has demonstrated a method to measure a very small deflection (smaller than the thickness of a human hair) of a beam of antiprotons, the antimatter counterpart of the proton. This is achieved by putting arrays of fine slits inside the beam (left figure), allowing only certain trajectories to pass these obstacles and to hit a detector. The arrival point of the surviving antiprotons is recorded with an emulsion detector that, like a photographic film, takes snap-shots of the antiprotons’ annihilation – the process in which antimatter and matter meet and subsequently reform into other particles. An example of such an “annihilation star” can be seen in the central figure below. These arrival positions are then compared to fringes of light produced by the same slits (right figure) – making it possible to determine the force that deflected the antiprotons. It is interesting that this method called moiré deflectometry only needs very few particles to work and is there therefore ideal for particles as rare as antimatter.



This demonstration results from the effort of an interdisciplinary and multinational group of physicists, combining techniques from different fields of physics. In future experiments, this method could be employed to measure the effect of Earth's gravity on antihydrogen, a force that is much smaller that the electromagnetic force measured here.

Join the dots to measure antimatter

Antimatter experiment seeks help from the crowd

Fat antiatoms, laser beams and matter-antimatter asymmetry

AEgIS apparatus at the end of 2012

Antimatter mysteries 3: Does antimatter fall up?

Apples falling...