Basic research in physics often consumes a great deal of energy, but there are visionaries who have been pushing through plans for how to save energy in the largest experiments for years. The chairman of the FZU's International Advisory Board, particle physicist Eckhard Elsen, is one of them. The former research director at CERN is also behind the upgrade plans for the particle accelerator - the High Luminosity Large Hadron Collider.
You once said in an interview that at CERN you worked with the brightest minds in the international community. Was it a challenge for you or rather a lot of stress?
A nice thing was that I got advice from a whole range of different people and so I was able to get a broad picture myself relatively easily; that was an interesting thing about the research director's job. Suggestions I hadn't thought of myself were particularly welcome. I then evaluated them, implemented them and, above all, explained them further.
I am of the opinion that I cannot represent more complex ideas unless I have understood them in principle at least. This basic understanding is necessary in order to be able to explain to a larger community, and especially to the funding agencies, what the funds are being used for.
In general, it is a good approach to first listen to what good ideas come in. This may not always have been easy for my staff because I wanted to understand the good ideas at least to some extent, which also took time. I am of the opinion that I cannot represent more complex ideas unless I have understood them in principle at least. This basic understanding is necessary in order to be able to explain to a larger community, and especially to the funding agencies, what the funds are being used for. So, I also may have challenged the experts from the finance committee to try and understand the science.
Which of your ideas will now be realised by your successor?
A big topic of the five years was the upgrade of the experiments and the accelerator, after the physics results following the Higgs discovery had practically suggested the path to the High Luminosity Large Hadron Collider. During the discussions, there were always changes in the ideas for building the detectors, which were really good, but then often needed more funding. Compromises had to be found here, which was accomplished. Soon there was no longer any doubt - even in the Council, the supervisory board of CERN - that the High Luminosity Large Hadron Collider would be the right experimental proposal for the next twenty years and more.
Another issue I wanted to get going was that computing should become more energy-efficient, more sustainable. Today everyone talks about it, but when I came to CERN, about 40% of the energy for cooling the computer centre was lost unused. So, it was a question of building a highly efficient computing centre, which will be completed in these years. Since the waste heat is also used to heat flats, megawatt savings can be achieved.
And as far as energy consumption in the accelerators is concerned, many programmes on how to save are underway. Magnets are being designed to be superconducting; operation is being levelled, injection does not come at peak times of power consumption, it is going in the direction of using the power when others are not using it. If we want to accelerate particles, we need to become more efficient, and a big step has been taken with radio frequency resonators that power the particles. They were typically only 60% efficient. Even an increase to 68% means a huge saving for the operation of the facilities and more is possible. I see this as an obligation to society and a necessity because cheap nuclear power from France is also a thing of the past. Unfortunately, the last few months in Europe have shown that the grid supply is quite sensitive.
What will be the societal consequences of the energy efficiency drive at CERN?
All accelerators in medical irradiation centres need energy, and efficiency will also be optimised by allowing us to adapt the treatment to the specific needs of the patient. Individualised treatment is becoming much more relevant than it used to be. Today, it is almost possible to measure the effect on the tumour during irradiation. The patient is then treated in a very specific way, minimising the radiation damage. This is an important development where not only the accelerators but also the detectors being developed at CERN play an important role. You need the inspiring environment of CERN so that such ideas can really be implemented.
Places like CERN contribute to the kind of knowledge that not only enriches humanity, but also provides the wellspring of ideas that become the technologies of the future.
You are known for your broad perspective, how is it that you manage not to lose sight of what is happening elsewhere?
CERN is a very inspiring place to work at and new ideas about research, technology and computing abound. Of course, there are also other research institutes that implement inspiring ideas and, above all, students and young researchers who constantly bring new ideas and implement them in their work. Thematically, I am now perhaps even trying to see further than I did as CERN research director, where it was primarily about physics. I now work at the Frankfurt Institute for Advanced Studies, where it's also about brain research. I would like to understand, for example, why our brain works so much more efficiently than the computers we build today. I'm talking about many orders of magnitude here.
Particle physicist Eckhard Elsen, Scientific Director of the Frankfurt Institute for Advanced Studies (FIAS), was Director of Research and Computational Sciences at CERN from 2016 to 2020. After completing his doctorate at the University of Hamburg, he worked at the Stanford National Accelerator Laboratory in California and the University of Heidelberg, and for many years at the German Electron Synchrotron (DESY).