Helmholtz is now 30 years old and we’re presenting the Association’s successes in 30 stories. One of them describes the successful collaboration with universities. This was also demonstrated by the successful outcome of the Excellence Strategy: Helmholtz Centers will be part of 32 clusters in the coming funding period. But we’re also making breakthroughs beyond these lighthouses. A team led by the University of Rostock and the Helmholtz-Zentrum Dresden-Rossendorf has succeeded for the first time in measuring liquid carbon, which will play an important role in future technologies such as nuclear fusion. And: In his viewpoint piece, Jan S. Hesthaven emphasizes the necessity of free science across borders for such achievements and explains how he plans to make KIT even more international.

Enjoy reading!

Since May, we have been telling moving and inspiring stories from three decades of Helmholtz under the motto “30 Years – 30 Stories” and posting one story a day together with our research centers on social media. Discover Helmholtz stories  

The aim of the call is to promote and initiate activities that address the challenges and methods of imaging in various Helmholtz research fields and centers. A particular focus is on the development of innovative approaches that significantly advance the processing of image data from sensor to publication. The application deadline is July 30, 2025. Apply now

Liquid carbon can be found e.g. at the core of planets and will play an important role in future technologies like nuclear fusion. Until recently, however, very little was known about carbon in its liquid form because it was practically impossible to study in the lab: Under normal atmospheric pressure, carbon does not melt but immediately changes into a gaseous state. Only under extreme pressure and at temperatures of approximately 4,500 degrees Celsius – the highest melting point of any material – does carbon become liquid. No manmade container could withstand that.

Laser compression, on the other hand, can turn solid carbon into liquid for fractions of a second. So, the challenge became using those fractions of a second to take measurements. What was previously unimaginable has now become a reality at European XFEL: Located in Schenefeld near Hamburg, the world’s largest x-ray laser is capable of generating ultrashort pulses. In the experiment, the high-energy pulses of the DIPOLE100-X laser drive compression waves through a solid carbon sample and liquefy the material for several nanoseconds, i.e., several billionths of a second. During this incredibly short time, the sample is irradiated with European XFEL’s ultrashort x-ray laser flash. The carbon atoms scatter the x-ray light – similar to the way light is diffracted by a grating. The diffraction pattern allows conclusions to be drawn about the current arrangement of the atoms in the liquid carbon. The entire experiment only takes a few seconds but is repeated again and again, each time with a slightly delayed x-ray pulse or under slightly different pressure and temperature conditions. In turn, these “snapshots” are combined to make animations, an approach that has allowed researchers to trace the transition from solid to liquid one step at a time.

The measurements revealed that, with four nearest neighbors each, the systemics of liquid carbon are similar to those of solid diamond. “This is the first time we’ve ever been able to observe the structure of liquid carbon experimentally. Our experiment confirms the predictions made by advanced simulations of liquid carbon. We’re looking at a complex form of liquid, comparable to water, that has very special structural properties,” explains the head of the research collaboration’s Carbon Working Group, Prof. Dominik Kraus from the University of Rostock and HZDR.

The experts also managed to precisely narrow down the substance’s melting point. Up to now, the theoretical predictions on the structure and melting point had diverged significantly. But precise knowledge is crucial for planetary modelling and certain concepts for power generation based on nuclear fusion.

Structure of liquid carbon measured for the first time (HZDR)

Childhood brain tumors develop early in highly specialized nerve cells

Medulloblastomas, or childhood brain tumors in children, are thought to develop between the first trimester of pregnancy and the end of the first year of life. Researchers at the Hopp Children’s Cancer Center Heidelberg (KiTZ), German Cancer Research Center (DKFZ) and Heidelberg University Hospital (UKHD) have now published their findings in the journal Nature.  more

Successful experiments at GSI/FAIR reveal new island of asymmetric fission

An international research team has identified an unexpected region of heavy, neutron-deficient isotopes in the nuclear chart where nuclear fission is predominantly governed by an asymmetric mode. Their findings will improve our understanding of the processes that create heavy elements in the universe and represent an important step in advancing theories on nuclear fission and fusion. They have just been published in the journal Nature. more

Image: HZB

Atoosa Meseck is a physicist at the Helmholtz-Zentrum Berlin and a professor at Johannes Gutenberg University in Mainz. Together with her team, she develops concepts and magnetic systems to generate light for experiments at accelerator facilities. She enjoys it when physics surprises her.

I work with a team of 15 colleagues on so-called undulators – essential components for synchrotron radiation sources. Electrons are accelerated to nearly the speed of light at these facilities. Our magnetic systems set them on a slalom course, causing them to emit energy in the form of light: synchrotron radiation. Researchers around the world use this unique light for their experiments – for example, to develop new batteries or catalysts. We develop and manufacture the undulators ourselves, often as customized individual pieces. We also supply them to other international research centers, paving the way for exciting research.

My work is about the interactions between matter and light. What fascinates me most is when we discover that physics behaves differently than expected. We take nothing for granted – and it is precisely these surprises that drive me as a scientist.

I often think back to a topic from my postdoctoral research: cloaking and metamaterials. Materials’ refractive index can be manipulated in such a way that objects coated with metamaterials appear to be invisible. And I’m convinced they could do much more. For example, we could use them to develop new types of optics for our beamlines. We currently direct the light generated in accelerators to various experiments one after the other. With metamaterials, the light could potentially be distributed to several experiments at once – which would be much more efficient and put the beam to better use! I’m very excited about trying out such approaches. Our successor source BESSY III could also benefit from this.

I would like to talk to Joschka Fischer about the responsibility of science, especially when it comes to research with potential military applications. Where does the responsibility of researchers end and that of politicians begin? As a politician, Fischer has seen firsthand that you always have to weigh your own ideals against the political realities. Talking with him would certainly be very informative.

The free exchange of ideas and the cross-border meeting of minds are the lifeblood of science. When political ideologies begin to obstruct these exchanges, more is at stake than just individual research projects. In the United States – until recently a global beacon of scientific openness – we are seeing increasing restrictions: Climate research, gender studies, and public health have become politicized, budgets are being slashed, and international collaboration is being questioned. Science is being exploited – or even attacked.

But scientific freedom is more than a value; it is essential. Especially in times of global uncertainty. Cross-border collaboration is key to scientific excellence and to the resilience of societies worldwide. Just consider the challenges of our time, from climate change to pandemic preparedness. Even during the Cold War – a low point in political dialogue – scientific exchange remained largely possible between nations. Continuing this tradition is not at odds with institutional neutrality; on the contrary, it reflects a deeply held conviction: that science must remain open, even – and especially – when political relations are strained.

This openness must be matched with strategy. Karlsruhe Institute of Technology (KIT) has sent a clear signal in this regard. By appointing a Danish president with academic roots in Switzerland and the United States, KIT has deliberately chosen an international outlook. I am honored by this trust – which also speaks to the institution’s remarkable openness.

But that openness is also a challenge for us. We’re on the right path, but we’re not there yet. As a student in Denmark, I saw for myself how crucial international networks are for scientific progress, especially in smaller countries. That lesson has stayed with me. True international excellence requires more than partnerships – it requires an environment that welcomes talents from around the world and helps them thrive.

We also need to prepare our students and staff to operate in global contexts. Bilingualism is an important step in that direction. English is gaining in importance – but German remains essential to who we are. With more than 200 years of history in Karlsruhe and the Baden region, KIT’s regional roots are a core part of our identity. Internationalism and regionalism are not opposites – they enrich each other.

KIT sees itself as an active player in an international network – within Europe and beyond. The Helmholtz Association strongly supports us in this mission. But we must also take action ourselves: by opening up career paths, creating reliable institutional frameworks, and enhancing our international visibility.

Germany needs to pursue internationalization – not just as a principle, but as a practical necessity. Like many European countries, Germany faces demographic decline. For KIT, with its strong ties to industry, this means that internationalization is not an option – it is a prerequisite for securing the future of education and innovation.

Internationalization is also a form of lived diversity. It brings fresh perspectives, fosters innovation, and connects people across the borders created by culture, language and nations. It’s not only a scientific asset; it’s an economic and societal imperative. Now more than ever.

Science can rebuild the bridges politics tears down. Amid geopolitical tensions, scientific collaboration creates a space for dialogue and mutual understanding. If we embrace internationalization not only as a strategy but as a mindset, science can become more than a tool for knowledge – it can become a vehicle for hope.

Around 75 years after the birth of quantum mechanics, fundamental findings on orbital and intrinsic angular momentum – the so-called spin-orbit coupling of electrons – formed the point of departure for developing the topological insulator, a completely new type of material. “The topological insulator represents a special class of materials because it is characterized by unique electronic behavior,” explains solid-state physicist Oliver Rader from the Helmholtz-Zentrum Berlin (HZB). On the inside, the insulator is non-conductive, i.e. insulating, for electric current. On its surface, however, current can flow virtually loss-free – a bit like a coffee can, although the topological insulator is made of a homogeneous material.

Read in Browser

Newsletter auf Deutsch abonnieren

Published by: Helmholtz Association of German Research Centres, Anna-Louisa-Karsch-Str.2, 10178 Berlin

Editors: Sebastian Grote, Franziska Roeder, Martin Trinkaus
Questions to the editors should be sent to monthly@helmholtz.de

Photo credit: Phil Dera (Editorial)

No subscription yet? Click here to register

If you no longer wish to receive our newsletter, simply click here: Unsubscribe

© Helmholtz