Visit to ATLAS at CERN
July 17, 2008
On July 18, 2008 I had the pleasure to see the ATLAS experiment at CERN, on a tour organized by Martin Jäkel. The three hour train ride from Basel to the Geneva airport was uneventful (except that the ICN continually swayed back and forth, making it difficult to walk down the aisle, and leaving one a bit seasick at the end of the trip). I quickly recoverd at lunch in the CERN cafeteria, and since the weather was good we could sit outside on the terrace. We had to wait a bit for a table, as the place was packed with physicists of all ages, discusssing their latest adventures. The magnet on the lawn (representing one of 1200 in the LHC tunnel) provided a small preview of the gigantic scale of the experiment we soon would see.
The LHC tunnel was already closed, and the two-month cooling period for the super-conducting magnets had already been long under way. Around the 6km.-diameter, circular ring of the large hadron collider ring (LHC) there are four experimental areas. The largest area is named ATLAS, and this is what we visited. But the ATLAS detector could still accomodate visitors for a few more days, even though official visits had come to an end. We were lucky indeed to be able to see this work of art.
The underground area is big enough to contain a five-story apartment building. What an extraordinary experience to actually visit the detector and its surroundings! In the photo I am standing on the catwalk, level with the center of the detector, and some 60 meters underground. This experiment represents the most extraordinary feat of engineering I had ever seen or even imagined. Not only is it impressive in the large, but when one inspects it closer and closer it is mind-boggling in every small detail. LHC will begin to operate shortly. At the moment CERN is clearly the experimental location where the most exciting new physics can be anticipated. You can sense the uplifting atmosphere of excitement everywhere, for all around many people are hard at work, and talking excitedly about what has been achieved and about what might lie ahead.
From left to right: 1. Cafeteria anticipation. 2. Shaft over the detector; just covered today--too bad. 3. Entrance to the experiment. 4. Visitor helmets. 5. Computer racks. 6. Cables and gas lines.
7. Detector view. 8. Catwalk with the muon chamber behind. 9. Martin in his element. 10. Argon expansion tank.
From left to right: 1. Elevator entrance with display, “Guide necessary.” 2.ID Checks. 3.Martin got through.
4. “Don't leave any metal tools inside!!” (Especially with 6 Tesla magnetic fields.)
5. Safe for key to visitor's door. 6. Get the code and log your visitors. 7.Part of many photo displays.