As an A-level science student, it’s never too early to adventure out into the real world, to see what it’s like working in a laboratory. For Annabelle Gill, the institute in question just happened to be the world-renowned CERN particle-physics laboratory in Geneva. There, she had the opportunity to spend a week meeting a host of CERN employees, from experimental physicists and electronics engineers to computing specialists and technicians, as she learnt about the many different experiments and devices housed in the Swiss and French countryside. She describes the fascinating facilities she visited, the people she met, and the variety of jobs she discovered are available to STEM students at research facilities like CERN.
In the last week of the summer term, my school – Hayesfield Girls’ School in Bath – asks all year-12 students (aged 16 or 17) to undertake a week of work experience. I was really lucky to get the chance to do my work experience at CERN, the particle-physics laboratory near Geneva, Switzerland, which houses the Large Hadron Collider (LHC). Much to my delight, my week was organized by electronics engineer Eva Gousiou, who is part of CERN’s Women in Technology group, so I got to spend time with many female scientists and engineers.
Monday
I started my week with high-energy physicist and University of Pittsburgh research associate Marilena Bandieramonte, who works on the ATLAS experiment, the largest detector at CERN. She initially showed me around the CERN visitor centre, which gives a great introduction to the overall purpose of the research at CERN.
In the afternoon, she described her work to me, which includes creating simulations for the ATLAS detector. She explained how her models can be employed by the ATLAS users to simulate their detector experiments and predict the likely outcomes.
Tuesday
The next day, I continued shadowing Bandieramonte, as she worked on improving the user interface for the ATLAS simulations, and I had the chance to visit the ATLAS control room. This was an exciting opportunity – while I had visited CERN previously on a guided tour, I’d only been able to see the control room from outside. But this time I was allowed to enter the room itself and see exactly what goes on in there.
Massive screens full of data and figures cover all the walls, showing information about the condition of the ATLAS detector. If anything were to go wrong, the researchers in the control room could make necessary adjustments. In the afternoon I attended a weekly ATLAS debrief, which included a general status update where they noted that the previous week the LHC had recorded collisions at its highest ever energy.
Wednesday
My third day’s plan was to meet Sophie Baron, an engineer in the experimental physics department, but this could not go ahead, as she had come down with COVID-19. However, I was able to learn about the group on a Zoom call with her instead.
I later met up with Baron’s colleague Philippa Hazell, who showed me around their laboratories, where they design and test the electronic systems and components used in the various experiments at CERN. She explained that the electronic chips they use could be affected by radiation from the particle collisions. To prevent this, the chips are designed with the digital logic repeated three times – and the majority decision used as the outcome.
Thursday
I spent the penultimate day with electromechanical technician Ellen Milne in the radiofrequency (RF) department, where they generate the signals used to accelerate particles in the RF cavities of the Super Proton Synchrotron (SPS) accelerator. This is the second largest machine at CERN, and it provides the accelerated particle beams for the LHC. I was able to see how they generate the power, including seeing tests done on an 800 MHz radio-frequency klystron.
After this I was driven out to visit the LHCb and CERN Axion Solar Telescope (CAST) experiments. LHCb studies the beauty (bottom) quark, and is looking to find a reason for the differences in the amounts of matter and antimatter within our universe. Meanwhile, CAST is an experiment searching for axioms – theorized particles that, should they exist, could be found in the centre of the Sun. They are also a candidate dark-matter particle, and their existence might help in explaining the matter–antimatter discrepancy, by tapping into the weak force.
Friday
On my last morning, I spent time with computer engineer Florentia Protopsalti, who works in the IT department. She took me into the control room for the Data Centre, from which CERN’s entire scientific, admin and computing infrastructure is run. Protopsalti explained that all the data from the experiments are sent there to be sorted. The majority of this information is not scientifically significant, so algorithms are used to decide which data to store and which to discard.
In the afternoon, I had the chance to meet with Eva Gousiou, who had arranged the whole job-shadowing week for me. She took me to see the CERN Control Centre. This is where they monitor and control the accelerators, including the Linear Accelerator 4 (LINAC4), SPS and the LHC, as well as controlling the cryogenics and tunnel access. I got to see lots of the screens displaying information surrounding the condition of the accelerators. Generally, the older the accelerator, the more that has to be done manually from the control room, whereas newer accelerators such as LINAC4 are more automated and require less input.
Overall, I really enjoyed my week at CERN. Everyone was really welcoming and, as well as my hosts, lots of other people offered to show me round their labs and explain things to me. I was particularly surprised by how many people had programming skills and how this was needed for their jobs. It made me think about my future career and the possible job options available at labs like CERN.
