CERN Open Days – Day 2 – Visiting ALICE (A Large Ion Collider Experiment) and the Prévessin Site

Our guide taking us underground where the actual particle transport take place – this is part of the 27km tunnel of the Large Hadron Collider. Our guide is a physicist with CERN since 1983 and is also shown here being interviewed in French!

Read Day 1 here – visiting LHCb (Large Hadron Collider beauty experiment), the CERN Axion Solar Telescope (CAST) searching for axions, LHCb Data Centre, and Scintillating Fibre Tracker

During the ‘long shutdown‘ CERN opened many of its site to be visited upon by thousands of visitors over a two day weekend on 14 and 15 of September 2019. I was one of those visitors, after having found out about the whole event in June on the morning that registrations opened.

ALICE (A Large Ion Collider Experiment) is a heavy-ion detector on the Large Hadron Collider (LHC) ring. It is designed to study the physics of strongly interacting matter at extreme energy densities, where a phase of matter called quark-gluon plasma forms.

The ALICE Experiment seek to answer some fundamental questions, such as:

  • What happens to matter when it is heated to 100,000 times the temperature at the centre of the Sun?
  • Why do protons and neutrons weigh 100 times more than the quarks they are made of?
  • Can the quarks inside the protons and neutrons be freed?

Waiting for the tour was a process in itself – at least three hours spent standing in 25 to 27C sunny weather somewhere in a French village alongside many other people!

Close up, ALICE experiment. Note the absorber in the middle.
A lot of work happens underground beneath the ALICE site. Not part of ALICE in particular, but rather a part of the overall LHC experiment.
The ALICE portion of the LHC experiment itself though currently in the process of being upgraded as seen by the scaffolding.
Awesome Canadian guide who is also at CERN – arrived there studying engineering at a university in Vancouver. However this is not the guide itself talking to us about the specifics.
The underground area where the magic happens. Well, not really magic! This is where the particle collisions take place, or at least the transport of said particles.

Visiting the Prévessin Site

Unfortunately, I was really tired after ALICE and briefly spent time at the CERN Prévessin site which is named after a nearby French village. I went to an exhibition tent set up which also covered the specifics of LHC. The amount of specifics covered – from the absolute minute right through to the 27 or so kilometre site was amazing.