At CERN, that is, at home

We begin our visit at the Community Support Centre. On a Monday morning, near the CERN complex, we encounter many people heading to work or, like us, to get their passes. The atmosphere is surprisingly similar to what we know from our university campus – there’s a pleasant excitement in the air as the new week of challenges begins.

After obtaining special access cards, we can begin our tour of the facility. However, the term "facility" doesn't fully capture the scale of this place. CERN covers an area of 620 hectares, partly on the French side and partly on the Swiss side of the border (though for visitors, the border is practically imperceptible – it runs through CERN buildings). On its grounds, we can find nearly 700 different buildings connected by a 30-kilometer network of roads. However, CERN is not just what we see on the surface; it is also – and perhaps primarily – a massive underground infrastructure. This is the case with the ALICE detector (A Large Ion Collider Experiment), which is accessed via a shaft over 50 meters deep. And it is ALICE, one of the four major experiments at the Large Hadron Collider (LHC), that marks the first stop on our journey.

The rich interior of ALICE

Our guide is Łukasz Graczykowski, PhD (ENG), associate professor at WUT, who has been involved with the experiment for many years. Although, due to ongoing data collection and the resulting radiation and powerful electromagnets, we cannot go down to the detector itself, we visit a multimedia exhibition that explains the structure and purpose of ALICE.

The main goal of ALICE is to understand matter – where it came from and whether its form has always been the same as the one we know today and recognize with our senses. The history of the Universe begins with the moment of the Big Bang. According to the narrator, as a result of it, within less than one millionth of a second, all the particles in the Universe were created. For a brief moment, they formed a dense, hot "soup," known as quark-gluon plasma, where quarks moved freely. Researchers want to examine the properties of this primordial state of matter in order to understand how the matter of the Universe was born.

– We accelerate lead nuclei to speeds close to the speed of light – explains Łukasz Graczykowski, our physicist and ALICE Team Leader. – In the collisions, we recreate the extreme conditions that existed in the first moments after the Big Bang, when protons and neutrons essentially melted, freeing quarks from their bonds with gluons. We study the process of the expansion and cooling of the quark-gluon plasma and observe the formation of particles that make up the matter we know.

These processes, of course, cannot be seen with the naked eye. Everything that happens in the detector is recorded by a team of several interconnected systems, which together can be understood as a massive three-dimensional digital camera with a billion pixels and extremely high resolution, capturing the directions and energy of particles produced in the collision.

Someone stays awake so others can sleep

CERN's detectors are a dream for engineers. Built with immense precision, they consist of numerous components designed to ensure uninterrupted operation for extended periods. This is crucial, as every minute of downtime in data collection and analysis results in significant losses. One hour of LHC operation is worth approximately 10,000 euros – here, time truly is money.

Although the systems are built with great care, someone always has to oversee their proper functioning. In the ALICE complex, there is an unassuming room known as the Run Control Center, which controls the experiment. One of the key features there is the Event Display, which operates continuously and provides the monitoring team with immediate insights into potential issues, both with the hardware and the software.

We have the opportunity to have a brief conversation with Zuzanna Chochulska, MSc (ENG), a doctoral student at both our university and the Czech Technical University in Prague, who was in the middle of one of her shifts in the control room.

– Each shift is an 8-hour cycle, during which those on duty must respond to any alarming signals related to the detector's operation – explains Zuzanna Chochulska. – The shifts are rotational, which can be a challenge for the body. Vigilance must be maintained at all times, day and night, and one must react swiftly to the information provided by the system.

Among the responsibilities, she lists monitoring data collection and the system used for this purpose, checking the status of individual subdetectors, and overseeing the condition of each detector. Access to data quality control is also essential.

What happens if something alarming occurs and there is a suspicion of a malfunction? In that case, shift workers are assisted by experts who are on standby 24 hours a day, including weekends and holidays. Usually, these experts try to resolve the issue remotely by logging into the CERN network and the experiment system. If that is not possible, they must be able to arrive on-site within thirty minutes.

In special cases, when there is a need to access the core of the experiment and diagnose a problem, it is often necessary to shut down part of the detector and wait for the right moment to allow a visit to the underground facilities. Each descent is accompanied by a safety protocol, starting with an iris scan—this is a necessary step to open the airlock doors before descending into the experiment. Every specialist who descends in the lift must be equipped with a helmet, non-slip shoes, and a dosimeter. In the rare case of working in areas where dangerous gas leaks may occur, one must also wear a specific type of mask. Importantly, no expert can enter the lower levels before the area has been inspected by personnel from the Radioprotection section.

The greatest expertise in this field belongs to Krystian Rosłon, who has overseen both the entire ALICE experiment and the key FIT (Fast Interaction Trigger) system at various stages, and has recently taken on the role of FIT Detector Control System Technical Coordinator. Our FIT experts also include Maciej Czarnynoga, MSc (ENG) and Monika Kutyła, MSc (ENG). As the CERN team members say: "No FIT, no ALICE." Without the FIT detector, ALICE cannot function, and without our specialists, ensuring the operation of FIT is impossible.

Continuous development

The people overseeing CERN experiments seem to be driven by a tremendous sense of responsibility for the proper functioning of the system and the success of the experiment, which involves research teams from all over the world. However, even more work is on the horizon. Maciej Czarnynoga, MSc (ENG), is part of the team developing the new subdetector, FoCal (Forward Calorimeter), which presents new opportunities not only for researchers but also for students.

Involving students and doctoral candidates in work at CERN is one of the priorities for WUT researchers. It not only ensures them opportunities for scientific development but also aims to broaden activities to encompass not just data analysis within a single experiment but also the creation of automation and control systems, improving data quality, and designing and constructing new detectors. Equally important is maintaining continuity—knowledge and personnel circulate, making it essential to pass the baton to younger generations and introduce new cohorts to the intricacies of the experiments conducted there.

This year, WUT managed to send a group of as many as 35 students and doctoral students to CERN. These young individuals hail not only from the Faculty of Physics but also from the Faculties of Electronics and Information Technology, Electrical Engineering, Mathematics and Information Science, Power and Aeronautical Engineering, Mechatronics, and Automotive and Construction Machinery Engineering. Krystian Rosłon and Maciej Czarnynoga decided to invite a few members of this group to participate in technical internships. After an initial selection process and interviews, five lucky individuals were given the opportunity to take their first steps in a world-leading particle physics research center. Their trip was made possible, among other things, by funding from the “Excellence Initiative – Research University” program and a ministerial grant.

Although CERN inspires global admiration, there are also skeptical voices. As an institution that consumes substantial resources, including contributions from member states, the inevitable question arises: whether and how these enormous investments yield returns.

The answer is both simple and complex, as it pertains to the essence of fundamental research. Its goal is not to create ready-to-deploy solutions, but to acquire new knowledge about specific phenomena, formulating and testing hypotheses. While searching out the truth about the origins of the universe, antimatter, and dark matter excites the minds of researchers and enthusiasts, it may not be sufficient proof of usefulness for many skeptics. Fortunately, CERN has demonstrated that fundamental research often produces "side effects" that positively impact people's lives around the world. Among these, one can mention the World Wide Web, PET diagnostics, and hadron therapy.

Investments in CERN pay off with interest. However, it is a process that can take decades, requiring immense patience. This is made clear by a visit to the Antimatter Factory, where particles, instead of being accelerated, are slowed down by a decelerator—then, the antiparticles travel to the infrastructure of several experiments, including AEgIS.

– When matter and antimatter collide, annihilation occurs – explains Jakub Zieliński, a doctoral student. – In theory, this could be used to develop an energy source of tremendous power, but it's still a vision for the future." He notes that so far, the amount of antihydrogen—neutral and "stable" antimatter—produced would only be enough to power a 60W light bulb for a few hours.

It requires daily, systematic work, research, and creating the conditions for freely discovering the laws governing both known and not yet fully understood phenomena. ALICE, AEgIS, as well as CMS, NA61/SHINE, and COMPASS are experiments in which researchers from the Warsaw University of Technology, including the Faculty of Physics, have made significant contributions. Poland has been a full member of CERN for over 30 years, and the Warsaw University of Technology is, in a sense, a co-owner of the experiments it helps fund. All indications suggest that our presence at this center will continue to grow. It is no surprise, then, that for physicists and many other engineers from the Warsaw University of Technology, CERN truly is a second home – just as Poland is officially a co-owner of CERN, the Warsaw University of Technology is a co-owner of the experiments it helps finance.