The UAA visits CERN
09 Jul 2011 in Alumni by Janneke van Kilsdonk
June 11th and 12th: Geneva, Switzerland
The world's biggest particle physics experiment, the biggest international scientific collaborative effort in human history, the birthplace of the World Wide Web, at forefront of technology for computing and wide area networking, expected to address some of the most fundamental questions of physics such as the experimental observation of the Higgs boson. Interested in a visit which could cover all this?
Yes, we were! After gathering at the station and the first round of counting people, we departed in a bus towards the CERN main entrance. The ride was a tough one for the bus driver. Nearby CERN there were some road works and off course all UNITECH engineers already saw the bus would never fit through those pawns. And they were right... The bus did not survive the trip without some scars.
At CERN we shortly visited the museum: The Globe of Science and Innovation. It was a round shaped, futuristic space in which the exponents were shown in interactive bubbles. If people were not overwhelmed by the exhibition they were by the technologies used to present it.
CERN in general
After a quick pizza, there was a PowerPoint presentation about CERN in general. Some interesting facts:
- CERN is one of the world’s largest and most respected centers for scientific research.
- CERN was founded in 1954 as Conseil Européen pour la Recherche Nucléaire. Today, CERN’s main area of research is particle physics. Because of this, the laboratory operated by CERN is commonly referred to as the European Laboratory for Particle Physics.
- CERN is run by 20 European Member States. Scientists come from around the world to use CERN’s facilities.
- CERN employs just fewer than 2400 people. Some 10000 visiting scientists, half of the world’s particle physicists, come to CERN for their research. They represent 608 universities and 113 nationalities.
- Tim Berners-Lee, a scientist at CERN, invented the World Wide Web (WWW) in 1989. The Web was originally conceived and developed to meet the demand for automatic information sharing between scientists working in different universities and institutes all over the world.
The research done in CERN is aimed to get insight in how matter is built up: of which particles it does exist and what are the forces holding them together. This research is done by letting particles beams smash under very high speed (almost the speed of light). During the collapse the particles will fall apart in elementary parts such as quarks. By studying those events, scientists hope to be able to define a theory that explains the four fundamental forces (electromagnetism, strong interaction, weak interaction and gravitation) in one elementary force. And they hope to find the Higgs boson, the particle that gives mass to all other particles.
And then the part where we all looked forward to: a tour along the different accelerators! CERN has six accelerators. The LHC (Large Hadron Collider) is the newest, biggest and most well-known one. During our UNITECH trip we followed the ‘lifecycle’ of the particles. We started at the LINAC2, an older facility which is still in use. One bottle of hydrogen gas (approximately 2l content) is enough to deliver all particles needed for 2 years of experimenting! It was our first experience with the amazing contradictories in scale. LINAC2 separates the electron from the proton, and starts the first acceleration. This is done by magnetic fields. These fields are generated by conductive material in the shape of a donut, which are placed behind one another and changes poles with high frequency. This respectively pulls or pushes the beam of particles towards the hole of the donuts. After LINAC2, the proton will be further accelerated in the circular PS Booster, PS, SPS and finally LHC. In the LHC it will hopefully collide (comparable with the scattergun approach, hoping that some bullets collide) with another proton which was accelerated in the opposite direction.
Then we visited LINAC3 were –certain periods of the year– lead ions (existing of several neutrons and protons) are accelerated. The collapses between the ions should give scientist more insight in how the universe originated (what happened during the big bang?).
We also saw a part of the controlling facility. By each accelerator information of the running of the entire system is shown. At the moment we were there, no experiments were currently running in the LHC. But we could see that it had been running that morning.
Unfortunately it was not possible to actually visit the LHC. Therefore we visited the LHCs testing facility, where the parts have been tested before construction in the ring. During this part of the tour, focus shifted from science and research towards engineering. In order to generate the enormous speed and energy levels of the particles some extreme measures are needed. First of all, it needs an incredibly strong magnetic field. This has been done by using super conductors. In order to keep the metal in super conductive state, it needs to be strongly cooled (till circa 2 Kelvin). Secondly an almost perfect vacuum is fundamental, in order to eliminate disturbing particles which are “flying around” in the accelerator. Third, tolerances as good as zero during construction are required. The 27 km long ring was constructed underground and exists of parts of about 15 meters (which are incredibly heavy). These all needed to be connected to one another very carefully. And finally measuring devises needed to be developed although it is not known what needs to be measured, since that is what we would like to find out. Very impressive!
After so much information and impressions we could share our thoughts during a tasty dinner in the Novotel. After dinner the ambiance shifted from satisfied over relaxed towards party mood. Genève is a great place to go out! The place where we went was very relaxed and all people were dressed very stylish.
The next day we started with a tour in the United Nations building. From the beta side we radically shifted to the alpha one. It was interesting to see the big conference rooms – which we normally see in the news bulletin on TV – in real live. We have even sat in one of the rooms! The guide explained to us why the United Nations has been founded and spoke about its role in peace negotiations all over the world. Realizing the amount of people which are involved in those kind of negotiations and the interests that are at stake in certain discussion, changed my conception on politics. This is highly complex problem solving as well, but in another force field.
During the day there were several times of saying goodbye to people who could not join to visit ALICE. No, she is not a pretty woman; it is A Large Ion Collider Experiment. Luckily, I was one of the people who could join. Andrea’s cousin is doing research at ALICE and showed us around. First of all we had a small lecture regarding the theory:
- Matter exists of molecules which exist of atoms which contain a nucleus and electrons flying around it. The nucleus exists of protons (and neutrons), which exists of quarks.
- In nature everything has a contradictory part (matter and anti-matter), since the total momentum (energy and/or mass) remains constant.
One of the research topics at ALICE is to try to understand how our universe came into being, if there is always as much matter as anti-matter. This is done by colliding lead ions which generate a so called soup of quarks for a fraction of a second. By studying what happens afterwards; how the quarks organize themselves, become protons or neutrons and eventually nuclei again. The explanation on how the measuring devices register this event and process it was to abstract for me. Not only the measuring devices were complex, also the data processing. The amount of data generated is enormous. It is not possible to save every result. Therefore a selection is made on which data is saved and which isn’t. Since researches from all over the world use this data, a separation has been made between the off-grid and on-grid part. At the end we quickly got a glance of the controlling room, which looked like the home base of a rocket launch!
And with all due respect, CERN is definitely rocket science and even more than that! It was a great opportunity to visit CERN. Andrea and Giorgio, thanks a lot for organizing this fantastic event!
You can find the rest of the pictures here
Janneke van Kilsdonk, UAA Alumna 2007