Question: What is the most unexpected thing that happened to you while experimenting?

Clara Nellist answered on 19 Mar 2014:

The most unexpected thing that happened to me was when I used the pixel detectors (a device to measure where particles are) that i work on in a joint experiment with a group called AEgIS.

They are studying antimatter at CERN and specifically they want to know if antimatter is pulled by gravity, like ordinary matter is, or if there is a chance that antimatter is actually pushed by gravity. We were testing my detectors (like a sensor in a digital camera) in a beam of antiprotons to see if they would work well for their experiment. I knew that the anti-protons would annihilate with the particles in the first few layers of the detector, creating some new particles. But I didn’t know that we would be able to clearly see the tracks of the new particles created from the annihilations. It was very exciting!

One of the most surprising things that has happened at CERN while they were running an experiment is the beer bottle story. This happened in 1996, before the LHC had been built. There was another particle accelerator in the same tunnel, called The Large Electron Positron collider. They had just finished doing some upgrades to the machine, but when they tried to send a beam around it wasn’t working. When they went to check it out, they found some beer bottles had been left in the path of the beam! Fortunately, because LEP ran at lower energy, nothing was damaged.