„IMPACT is very important in terms of international competition“

Dr. Kiselev, the IMPACT project is still in the planning phase. Would you like to do some advance publicity for it?

With IMPACT, we want to realise a crucial upgrade to a large and central facility at PSI, namely our proton accelerator HIPA. The planned expansion is a further contribution to keeping the research landscape of Switzerland at the top level internationally. That is why IMPACT is of strategic importance for PSI. The prerequisite, however, is that the Swiss Parliament agrees. This is the established process for funding large projects within the framework of the Swiss Roadmap for Research Infrastructures.

And IMPACT is already on this Roadmap?

Yes, since the summer of 2023, when the Swiss State Secretariat for Education, Research, and Innovation SERI published its ERI Dispatch 2025-2028. The Swiss Parliament will decide on this ERI Dispatch, and thus on the financing for IMPACT, at the end of 2024. At PSI we already have experience with this process: We have successfuly navigated this procedure for the construction of our newest large research facility SwissFEL as well as for SLS 2.0, the current project to upgrade our Swiss Light Source.

What makes the proton accelerator HIPA so special now?

In February 2024, HIPA will celebrate its 50th anniversary. And you can say that the facility has been enabling top-level research in many disciplines for five decades. Facilities of this size do not lose their importance. They even increase in value if you invest in them consistently over time. We are doing this now with the planned upgrade, among other things, and thus HIPA will also be able to serve future generations of researchers. Other, comparable facilities around the world are investing too, and they’re catching up.

Does that mean HIPA is the top facility of its kind worldwide?

It is, actually, in some of its parameters. HIPA delivers an intense, continuous beam of accelerated protons. Protons are positively charged particles that are found in every atom. At PSI, the accelerated protons are guided into enormous halls, to various large research facilities, where they are used to generate additional so-called secondary particles. With these secondary particles, scientific investigations are carried out at more than 30 different experiment stations.

Muons are one type of secondary particle that we use a lot at PSI. These are somewhat less well-known elementary particles, but they, too, arise completely naturally, for example in our atmosphere. At PSI we generate them in a targeted manner. We have the highest intensity of muons, worldwide, that can be used in experiments. Other facilities around the world are now catching up, at least in part, through their own further developments. IMPACT is very important in terms of international competition, because with it we will increase our maximum muon flux here at PSI by a factor of 100 and will, in the future, make 10 billion muons per second available for research in particle physics and materials science.

And why are such enormous numbers of muons needed?

Muons are unstable and therefore decay into other particles after a short time. Such particle decays are very exciting scientifically, since they can reveal a lot about the fundamental rules of physics. Research at CERN is also pursuing this approach.

For example, at PSI we are searching for certain decays in muons that would point to a world beyond the standard model of particle physics. This standard model is meant to describe our entire universe, to the greatest extent possible, but there are several astrophysical observations that contradict it. Therefore, these particular decays are being investigated in international collaborations, and leading experiments are taking place here at PSI. With the muon flux available up to now, we soon will have exhausted the possibilities for finding the critical particle decays. In the future, we will only make further progress on this research question by increasing our muon flux even more, thanks to IMPACT.

Will IMPACT also help us address more mundane questions and problems?

We also use muons to investigate novel materials. This reveals fundamental properties of materials, and that‘s important for the development of new technologies. IMPACT will lead to the ability to measure much smaller samples more rapidly, and to examine a larger area than before, from the surface down into the solids within. With that we can gain new insights in materials science.

Second, IMPACT will also help in nuclear medicine. We are planning an entirely new facility that will serve research into targeted, personalised cancer therapy. Here the emphasis is on developing so-called radionuclides or radiopharmaceuticals for medicine. These are already being used today to treat a few types of cancer. We want to be able to provide the right radionuclides for every type of cancer and every stage of cancer. Our focus is on radionuclides of the same chemical element, which can be used both to diagnose and then to fight cancer. This dual use has the major advantage that you can predict quite well how the body will react to the treatment, so that you can adjust the dose if necessary.

Now, the Swiss Parliament will not decide on financing until the end of 2024, and yet a lot of work needs to be done in preparation for IMPACT. How does that work?

If a positive decision on financing is made at the end of 2024, the first physical renovations will have to begin shortly afterwards, since IMPACT is planned for the research funding period beginning in 2025. So the planning and a lot of preparatory work has to be done now. PSI is investing in this itself and has pledged 1.2 million Swiss francs per year for 2022, 2023, and 2024 for preparatory work.

Could you give some concrete examples of this preliminary work?

First, we produced a 300-page Conceptual Design Report CDR in January 2022. It already contains the basic plan, from the scientific motivation to the first technical concepts and calculations. This report was the basis for PSI’s own pre-financing. Next up is the Technical Design Report TDR, which contains the technical elaborations of the concepts. This would correspond, in the case of building a house, to the detailed construction plan in compliance with applicable regulations. For this we are currently creating the concepts and CAD models – that is, computer-aided design models – for each individual future component. This amounts to thousands of CAD models that we are currently putting together in huge three-dimensional puzzles, with an enormous number of details and technical challenges.

You have indicated that the renovation will affect several areas in the halls around HIPA.

That’s right, and we’re taking advantage of this opportunity to optimise routes and processes. For example, the evacuation routes in the hall: We have managed to make these shorter than before thanks to the renovations, and in the future they will no longer include any stairways. This will make our facilities even safer and naturally benefits everyone.

In addition, a cryo-station, where liquid helium is filled for use in experiments, has to make way. We have taken this as an opportunity to move it to a new location that will be more accessible. Up to now, the cryo-station stands elevated, so practically all the filling containers need to be transported there and back by crane, which costs us a lot of time over the course of the year. At the new location, it will be much easier to access, and we can eliminate more than half of the 2,000 crane transports per year.

To make such a complex, large-scale project manageable at all, what does it take?

I would say: an engaged project management team and the involvement of more than 100 other experts from five PSI divisions. The IMPACT upgrade project affects researchers in biology and chemistry, in neutron and muon research, and in nuclear energy and safety, and beyond that the people in the area of large research facilities, and finally in logistics. Even for the inherently interdisciplinary PSI, that makes it a unique collaboration on a single large-scale project.

Coordinating this is certainly demanding, but it is also very exciting, because all of the experts involved have very valuable input to offer. And it is precisely this diversity of competencies we have here at PSI that is our strength. From the researchers at the beamlines to the experts on so-called targets, magnets, beam diagnostics, and simulations, and on to the development of detectors, the necessary infrastructure without which nothing works, and much more, all under the watchful eye of occupational safety – we have all that expertise on site, and we need them all.