Study visit at CERN

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GU Journal visiting

Text: EVA LUNDGREN Photo: JOHAN WINGBORG

CERN, the world’s largest particle physics laboratory, is where the most fundamental phenomena in the universe are studied, where antimatter is created and where the Higgs particle was discovered.

It is also where the Department of Physics conducts a field trip every year.

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Fredrik Wenander holds a lecture for Dag Hanstorp and Rouwaida Yassin.

Annie Ringvall Moberg is a PhD student at Isolde.

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prepared and work effectively while you are there. In November last year, we succeeded with the measurement we had been struggling with for so many years, so it was a major breakthrough.

In this project, thirty researchers from several universities participate. Five of the researchers are from the University of Gothenburg. Their work is devoted to an element called astatine. It is estimated that there are only about 70 milligrams of the element in the part of the earth’s crust that can be mined, and the reason it is so rare is that it has a half-life of just one second. Obviously, this makes it difficult to study.

CERN IS JUST OUTSIDE Geneva and is like a small community, full of laboratories, a noisy canteen, coffee machines, ATMs and a souvenir shop for the many visitors from all over the world. Research is carried out here within the fields of particle physics, nuclear physics, biology and nuclear medicine.

Each year, the Department of Physics invites students who are in their third year of the physics programme or who are undertaking teacher training specializing in physics on a trip to CERN. Three upper-secondary school teachers are also invited.

This year’s visit took place on 15–18 May and the hosts were Professor Dag Hanstorp and PhD student Annie Ringvall Moberg. They both work on a project at ISOL- DE, a facility for the production of radioactive isotopes.

– At ISOLDE, elements that do not occur naturally, but which can have interesting properties, are produced, says Dag Hanstorp. You can apply for research time, and you can also order which beam you want to investigate, and then you have three days to carry out your tests. In the five years my group’s project has been underway, we have been allocated research time on three occasions, so it is really important to be well

– THAT IS WHY we create new elements at ISOLDE where it is possible to investigate them. We bombard uranium with extremely high-energy protons, which results in nuclear reactions where all existing elements are formed, one after another, including astatine. The resulting astatine isotope that we obtain has a half-life of about seven hours. What we succeeded in doing in November was to measure the isotope’s electron affinity, which provides fundamental information about its chemical and physical properties, which were previously unknown.

The fact that Dag Hanstorp’s research team was successful in their experiments was a relief for several reasons. For example, the Large Hadron Collider (LHC) closed just a week later for maintenance, for the replacement of magnets and other updates, which will go on for approximately two years.

THAT STUDENTS GET to visit CERN, look at the various facilities and meet the researchers, Dag Hanstorp believes is important, not least to motivate them to pursue post-graduate studies.

– We were also accompanied by three physics teachers from the University of Gothenburg’s catchment area. It is about inspiring people and increasing the knowledge of everything that is interesting in the vast field of physics, and teachers of course play a crucial role in this.

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– I was at CERN for the first time on a field trip in the spring of 2015, and then as a summer student for eight weeks. One year later, when I was able to start my PhD project here, it was a dream come true.

Annie Ringvall Moberg, who works at ISOLDE – a kind of isotope factory for material that cannot be studied in nature, tells us.

IT INVOLVES HEAVY, radioactive material that quickly decays in nature and therefore cannot be studied, says Annie Ringvall Moberg.

– Primarily, we are interested in astatine, the world’s rarest element, which has a half-life of one second. The isotope we produce here has a half-life of 7 hours.

Annie Ringvall Moberg is studying experimental physics. It involves a lot of practical work but also a lot of theory.

– I REALLY APPRECIATE this mix and that I get to work with people from very different backgrounds. I have also been involved in building a test and development lab for ISOLDE. This means that I have learned about the hardware and what you can do with it, which naturally I found very beneficial.

Although Annie Ringvall Moberg’s study of astatine is pure basic research, there is also a very practical

application. This involves a particular type of cancer therapy, targeted alpha therapy, and Sahlgrenska University Hospital is one of the world leaders.

– The trials involve injecting astatine that is linked to an antibody, which then seeks out and attacks the cancer cells. The astatine then decays by sending out so-called alpha particles that have a range the distance of a single cell. You could compare it to a target-seeking missile, which destroys the cancer cells, but does not harm the surrounding healthy tissue. The fundamental knowledge we have now obtained about the properties of astatine will hopefully be used to make the treatment method more efficient.

ANNIE RINGVALL MOBERG together with Dag Hanstorp were the hosts of the field trip to CERN. She held lectures, showed people around the area and told them about her work.

– I think it is very useful to explain your research to others. When I was an undergraduate myself, I thought it was exciting to meet doctoral students, who you can talk to in a more relaxed way. But it is also interesting for me personally, to meet dedicated students. They ask a lot of questions, sometimes about things I haven’t thought about myself, which of course means that I have to reconsider my approach.

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What was the high point of your visit to CERN? I think perhaps it was the CMS, the Compact Muon Solenoid, one of the detectors at the LHC accelerator.

Wearing hairnets and hard hats, guided by postdoc Leonora Vesterbacka, the visitors from the University of Gothenburg took the elevator 100 metres underground to look at one of the particle detectors that are hunting for more information about the elusive Higgs particle and theories beyond the Standard Model.

THE VISIT TO CERN involves a packed programme of lectures and tours every day.

– It was really tough, but I’m glad they packed in as much as possible. In addition to the CMS, we visited Atlas, the world’s largest detector, in terms of volume, ever constructed for a particle accelerator. I think the whole field trip was very well planned, not least meeting Annie, who told us what it is like working here as a doctoral student. I’m also fascinated by the fact that all the collaborations seem to work very well, explains

physics student Adnan Jordamovic. He thinks he will continue his studies to Master’s level eventually.

Another student, Anton Krouthén, was also satisfied with the trip.

– I WOULD NEVER have been able to obtain this indepth knowledge if I had visited CERN as an ordinary tourist. The programme also connected well with what we have studied. I appreciate the trip being so intense; they have given me so much more than I expected.

Rouwaida Yassin, subject coordinator in physics at Hässleholm’s technical school, points out that there is not much information about nuclear and atomic physics in the upper-secondary school curricula.

– I have organized various field trips myself and therefore have great appreciation for all the work that has gone into this field trip. What fascinates me most is realising everything human beings are capable of. Imagine being here, where so many researchers spend years working on and committing to major or minor experiments. There are no words to describe that feeling, it can only be experienced right here at CERN.

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Dag Hanstorp discussing with Anton Krouthén and Adnan Jordamovic.

Facts

Fundamental physics is perhaps what most people associate with CERN.

The matter we know of, that is everything from human cells to galaxies, make up only about 5 percent of the universe; the rest consists of dark matter (23 percent) and dark energy (72 percent). The model that describes the smallest particles in the universe and three of the fundamental forces, is called the standard model. The model includes however, not the force of gravity.

Scientists hope that, with continued experiments at the LHC, they will be able to confirm theories beyond the standard model, theories which include the gravitational force as well as new findings of particles. In addition, researchers also hope the LHC experiments will provide direct clues to what dark matter and dark energy actually is.

Much of the world’s progress within particle physics is made at CERN. For example, in June 2012 researchers announced that they had found the Higgs boson that describes why some particles have mass. At CERN, researchers have also succeeded in producing antimatter.

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Dag Hanstorp has been able to use Isolde at CERN three times during five years.

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Facts CERN

CERN is the world’s largest particle physics laboratory, located near Geneva. The facility was founded in 1954 by 12 countries, including Sweden. Today, the laboratory has 23 member countries.

CERN has 2,500 employees and 6,500 guest researchers from 500 universities all over the world.

CERN is perhaps best known for the Large Hadron Collider (LHC) particle accelerator. It consists of a 27-kilometre circular tunnel where particles travelling in opposite directions collide with one another. The main magnets in the tunnel operate at a temperature of –271.3 degrees Celsius, which is colder than out in the universe and as close as you can get to absolute zero, –273.15 degrees Celsius.

It was also at CERN that Tim Berners-Lee developed the World Wide Web, where the first website was created on December 20, 1990.

GU Journal has made a film about CERN

Watch the film:

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