Today, we visited CERN. Visits and guided tours are free, although guided tours book up very fast in the summer. Tickets aren’t available for a guided tour on a certain day until 15 days before, and in summer can be booked up in seconds.
First, we went to the globe, where there is an exhibit called the Universe of Particles. In the exhibition, there were various displays of things that are connected to CERN, like papers about the Higgs-Boson particle, an original proposal for the internet, and the first particle accelerator. There were also touch-screen displays showing graphics about the accelerators and a projected film about the development of particles right after the Big Bang.
Once we were finished with the Universe of Particles, it was nearly time for our tour. Nate didn’t come on it, since the minimum recommended age for the tours is 12. The three of us got our visitors badges, then waited until we were told to go into a presentation room, where the basic structure of the tour was introduced and another guide tried to fix the tech problems that come with conference or meeting room screens. He got it working, and we were given a presentation on what CERN is.
After that, the tour group was split up into two groups that did the tour in opposite orders. We started by going to look at the first particle accelerator at CERN, the Synchrocyclotron. It was constructed in 1957, right after CERN was created. The walls of the building it’s in are 5 meters thick!
After looking at a presentation about the Synchrocyclotron projected onto it, we went into the other permanent exhibit, the Microcosm. At the beginning of it, there was a map of the accelerators and an explanation of where they get the protons that they accelerate – They are extracted from hydrogen.
The next part of the permanent exhibit showed the acceleration pipe. It’s only around 60 cm in diameter. Inside, there are two pipes that are only a couple cm in diameter, which is where the proton beams go. Around that are superconductor coils that produce the magnetic field, using 18500 amps, which are surrounded by insulation.
After seeing the acceleration pipe, we looked at a cross-section of a detector. It has several detection layers – the pixel detector to detect the location of the particles coming off of the collision, a magnetic field to cause the particles to turn to detect the velocity of the particles as well, surrounded by crystal detectors that measure the energy of the particle by turning the energy into light, surrounded by muon detectors. The detectors are very large – the CMS is the smallest, and it is 15 meters high and 21 meters long.