As of 30 November this year, Russian scientists will no longer have access to the facilities of the European Organisation for Nuclear Research, including the Large Hadron Collider. This is not the only loss for Russian scientists, nor is it the only instrument of science to which access has been cut off due to Russia’s invasion of Ukraine. T-invariant takes the example of the European XFEL free electron laser to understand what this means for science and prospects for co-operation and what scientists who have lost access to this modern and promising research method are doing.
A bit of history
Let’s start with the historical background, and it’s hard to know whether it’s more about pride in the talent of scientists who started their scientific careers in Russia, or sadness about the lost opportunities and the number of talented specialists who are forced to leave our country.
Even in a good optical microscope it is impossible to see objects smaller than the wavelength in the spectrum of visible light. Not surprisingly, the discovery by Wilhelm Roentgen at the end of the nineteenth century of X-rays, the wavelength of which is much smaller, gave researchers new perspectives in the natural sciences and medicine. Suffice it to recall the role of X-rays in the discovery of the double structure of DNA. High-energy physics developed in parallel. At first, the radiation of accelerating elementary particles was predicted theoretically. But in 1931 the first particle accelerator, the cyclotron, was built . It was only about 10 centimetres in diameter and accelerated protons to only 80 kiloelectronvolts.
As a charged particle moves with acceleration, it emits photons. The higher the particle speed, the higher the photon energy. Until recently, synchrotrons were considered to be one of the most powerful sources of X-rays. In them, electrons move at near-light speeds around a circle with a diameter of hundreds of metres and experience centripetal acceleration due to rotating magnets.
A new word in science is the free-electron laser. In this device, the source of radiation is a beam of electrons in vacuum, passing through a series of magnets arranged in a special way (ondulator) and thus emitting photons in the form of X-rays.
The main news about the life of scientists during the war, videos and infographics – in the T-invariant telegram channel. Subscribe so you don’t miss out.
Today there are powerful synchrotrons in almost every developed country. But gradually the scientific community has come round to the idea that it is not at all necessary for each country to build its own powerful accelerator. It is possible to build a public facility, provide a team to monitor and improve performance, and let others use it for their own research.
The role of scientists from the Institute of Nuclear Physics (INP SB RAS) in Novosibirsk Akademgorodok in creating free electron lasersis interesting . The design of such lasers was proposed in 1980 by Evgeny Saldin, an employee of the Institute of Nuclear Physics SB RAS. The first experimental confirmation of the possibility of resonatorless X-ray LSE was made in the early 2000s in the USA (with the participation of Nikolay Vinokurov and other former employees of INP SB RAS: Emil Trakhtenberg and Isaac Wasserman) and in Germany (again by former INP SB RAS staff members: Mikhail Yurkov and the already mentioned Evgeny Saldin). The LCLS (a free electron laser facility located at the SLAC National Accelerator Laboratory in Menlo Park, California) was built and launched in 2009 by staff from five U.S. government laboratories, including more than a dozen former employees of the same institute.
What is XFEL
TheEuropean XFEL is first and foremost the free electron laser itself, which is located in 3.4 kilometres of underground tunnels from the DESY campus in Hamburg to Schönefeld in Schleswig-Holstein. It also provides workplaces for 300 XFEL scientists, engineers, technicians and administrative staff, as well as guests of the research centre, and various laboratories, including sample preparation. It is an opportunity to use intense ultrashort X-ray flashes to study extremely fast processes, tiny structures and extreme states of matter.
European XFEL. Photo: cen.acs.org
– Free electron laser is not quite an accurate term,” says a European XFEL specialist with whom we had a chance to talk. – I think that the term has moved from the conventional laser because of the exponential growth of radiation, which is there and there. Laser is an abbreviation of Light Amplification by Stimulated Emission of Radiation, which means “light amplification by stimulated emission of radiation”, which is not quite true for XFEL. The main difference is that a conventional laser does not work on free electrons, but on electrons bound to an atom.
The European XFEL, like other similar devices, starts with the generation of a high-energy electron beam. The electrons are accelerated using a linear accelerator based on superconducting technology. The beam is accelerated almost to the speed of light, reaching very high energies (up to 17.5 gigaelectronvolts). To accelerate the electrons to these energies and focus them, the linear accelerator uses magnetic fields. When the electron beam reaches high energy, it is directed into a special section with alternating magnets called an ondulator. In the ondulator, the electrons begin to move along a wave-like path. In this process, the electrons emit X-ray photons (hard X-rays up to 20 kiloelectronvolts).
X-rays are enhanced by the effect of spontaneous emission. At first, electrons emit photons chaotically. However, the photons then begin to synchronise and amplify each other, producing radiation that is similar in properties to laser radiation. The power of this X-ray radiation is 6-7 orders of magnitude higher than synchrotron radiation and 20 orders of magnitude higher than the radiation in a familiar X-ray tube, which is used by doctors.
– The process of amplification in LSE is similar to the effect when in a concert hall microphone is brought too close to the speaker, to which he himself is connected – suddenly there is a very powerful sound signal – says in an interview with the publication “Science in Siberia” Andrei Trebushin, at that time a senior laboratory assistant at the Institute of Nuclear Physics SB RAS, and now an employee of the European XFEL. – This process is called noise signal amplification in a feedback amplifier.
Why XFEL is needed
– Imagine that you came to a football match, sat down in your seats and saw only the initial score, 0:0, and the result of the match – say, 5:1. You are shown only two frames and you do not know how the game was played,” explains the main differences between XFEL and synchrotron in an interview with the Atomic Energy 2.0 portal, Sergey Molodtsov, Scientific Director of XFEL Evropean. – For example, the European accelerator ESRF with a pulse length of light thousands of times longer than that of XFEL allows us to see the initial state of matter and the final product of the reaction we are studying. All the most interesting things remain behind the scenes.
But XFEL, in his view, allows you to see in detail all that is left behind. According to the European XFEL website, the free-electron laser allows scientists to shoot “molecular cinema”.
In 2009, Ada Yonath, Venkatraman Ramakrishnan and Thomas Steitz won Nobel prizes “for studying the structure and function of the ribosome”. It took them 20 years to assemble crystals of single ribosome molecules and get a reasonably clear picture of their structure. Today it can be done more easily. A large number of photons allows you to get the necessary data literally in one “shot” XFEL on a single molecule. So the existence of XFEL promises us in the near future to unravel the structure of many biological molecules, viruses and crystals. Understanding the structure of these objects, as well as their temporal changes, could be the basis for the development of future drugs and treatments. Among the interests of European XFEL are energy, including the creation of artificial photosynthesis, catalysts, information technology, water research, astrophysics, etc.
It may seem that free electron lasers have supplanted and replaced synchrotrons.
– These are just two different tools, using which you can study different facets of the same problem,” one of the employees of the INPh SB RAS told T-invariant us. – SKIF (Siberian ring photon source) is being built (and hopefully will be successfully completed) near Novosibirsk Akademgorodok. To say that we are building an obsolete facility would be fundamentally wrong.
– If you look, you will notice that next to all the existing free electron lasers there is a large synchrotron,” points out an employee of the European XFEL. – This is no coincidence. They have a very similar field of application, but the parameters are different. It is like comparing two cameras, one of which shoots in ultraviolet. There are powerful synchrotrons near European XFEL as well.
The control room at DESY Bahrenfeld, from which the accelerator is controlled. Photo: xfel.eu
Optical computers caught up in the war
In biology, a synapse is a contact between two neurons or between a neuron and a cell of some organ. In our organism, the impulse is transmitted chemically: a neuron releases a special substance – a mediator – into the synaptic cleft, which generates a nerve impulse in a neighbouring cell. Egor Pritotsky, being a researcher at the Laboratory of Neuromorphic Optical Systems of the Institute of Laser and Information Technology Problems of the Russian Academy of Sciences, a branch of the Federal Research Centre “Crystallography and Photonics” of the Russian Academy of Sciences, worked on the creation of artificial synapses for neuromorphic systems, where the impulse can be transmitted optically. This would significantly increase performance, speed, and a variety of other characteristics. The work of Pritotsky and his colleagues is based on materials that change their phase state under the influence of laser pulses: from polycrystalline to amorphous and back again. They were able to study the change in optical properties of nanofilms during such a phase transition (refraction, reflection, absorption of light), calculate the structures themselves and the degree of exposure to obtain the desired properties at different ranges.
Up-to-date videos about science during the war, interviews, podcasts and streamings with famous scientists – on the YouTube-channel T-invariant. Become our subscriber!
– It was important to control the levels of light transmission in a controlled way, as it happens in already existing artificial neural networks, – explains Egor Pritotsky. – We wanted to create, in a sense, an analogue of a quantum computer that would work on the principles of optics. Optical processors can occupy the niche of accelerating the training of neural networks and creating their own neural networks. Optics can overcome the theoretical fundamental limit of silicon machines in terms of data processing speed. The creation of optical processors is not just the next step in the creation of new supercomputers, it is a huge leap in the development of IT technologies and the processing of large databases.
There are already a number of theoretical works that show the existence of such reversible phase transitions for a whole range of materials, which were carried out on linear or ring accelerators. An important question remains: how exactly this knowledge can be used in practice.
– The processes we studied are very fast,” explains Pritotsky. – And you can only see them in dynamics at accelerators. We were preparing an application for the use of the XFEL accelerator in Europe from an inter-institutional group of three scientific institutes. It is important that Russian scientists, as it was explained to us, had a quota in the use of XFEL. In this case we would be provided with everything we needed, no additional expenses (except for transport) were expected. We would have our own time on the equipment and the opportunity to publish our results in leading international scientific journals. I participated in an online XFEL conference where we discussed this project with the FXE instrument (the XFEL laboratory where the femtosecond laser is used to initiate phase transitions).
The online meeting with European XFEL took place on 23 February 2022. On 22 March, the European XFEL website announced that cooperation with Russian organisations was being terminated and that no new applications would be accepted.
– We didn’t need to organise a new meeting to realise that our application had no future,” says Egor Pritotsky. And, as he points out, not only did the Russian team’s opportunity to conduct research at European XFEL disappear, but the team itself also disintegrated: the institute where he worked came under the aegis of the Kurchatov Institute. Part of the team was forced to leave science, but even those who remained reoriented themselves to other projects and topics under new priorities.
According to Pritotsky, funding for research became more difficult to obtain after the liquidation of the Russian Foundation for Basic Research. For example, on a grant from the Russian Foundation for Basic Research, some of the money must first be paid in taxes, and some of it must be transferred to the institute on whose behalf the grant was submitted. But even the remaining money often goes to the grant applicants, but the corresponding amount is deducted from their salaries, and they can only get the same money as before they applied for the grant.
Egor Pritotsky signed the Open Letter of Russian Scientists and Science Journalists Against War and left Russia with his family in early March 2022 with the first wave.
– Back then it was still possible to express your opinion, but after that the legislation changed a lot,” Egor believes. – They asked for a resignation letter and dismissed us in one day without pay from the beginning of 2022. We consciously decided to leave the country after 24 February and we do not regret our decision. We really hope that all this will end and there will be a world where scientists and teachers can develop science and education.
Now Egor works as a teacher in the UAE and is looking for opportunities to return to science and continue his research.
What have we lost?
This question was difficult to answer for all of our interviewees. Among the most frequent answers were the following:
- The opportunity to use technology that is at the cutting edge of science.
Today, there are literally only a handful of free electron lasers in the world. Besides Germany, there are such facilities in Italy (FERMI in Trieste), in the United States (LCLS at the SLAC National Accelerator Laboratory, California), in Japan (SACLA at the Harima RIKEN Institute in Hyogo Prefecture), in South Korea (PAL-XFEL at the Pohang Accelerator Laboratory), and in Sweden (SwissFEL at the Paul Scherrer Institute, Aargau Canton). But all of them are currently inaccessible to Russian scientists.
– This is a great loss, – Egor Pritotsky is sure. – It is impossible to imagine modern science without world-class instruments. And the X-ray free-electron laser is one of such devices. Probably, a ban on participation in such research is comparable to banning athletes from participating in the Olympics. The opportunity to work in one’s own labs, only on one’s own devices, and then publish only in Russian journals is not the most promising path.
We talked to colleagues at conferences on microelectronics, and their heads, academicians, told young specialists how far behind Soviet science was in their field, being cut off from the rest of the world. For the scientific community, openness, the ability to exchange ideas and results, is very important.
- The opportunity to save money.
EUR 1.3 billion was spent on the construction of the European XFEL alone. The annual operating costs are about 120 million euros. This is a huge sum – such an expensive project in both construction and utilisation is probably within the means of the Russian budget. But joint construction and use is much more favourable both economically and diplomatically. In order for the centre not only to function but also to develop, it is necessary not only to invest money but also to find new ideas. It is much easier for a collective project of several countries to do this than alone.
– Shareholder contributions were made to the construction of the facility, and the process has been completed. The Russian contribution to the total construction budget was 27 per cent, which is based on the percentage of shares in the facility,” Bernd Ebeling, Head of Press Relations at European XFEL, explains to T-invariant the economic component of Russia’s participation in the project. – Shareholders also contribute to the annual operation of the facility. From 2024, contributions to the operation budget take into account both the shareholding percentage and the use of the facility by users from the shareholder countries. As users associated with Russian organisations are currently not allowed to come to European XFEL to conduct or participate in experiments due to EU sanctions, the Russian contribution to the operation budget has been significantly reduced to about 17%. No compensation is envisaged because research time at European XFEL (beamtime) is allocated free of charge on the basis of scientific excellence and not on the basis of shareholder contributions. In other words: shareholders do not contribute to get beamtime. They contribute to the operating costs to make the research facility available to the global scientific community for the benefit of society
- Openness and links with the West
Egor Pritotsky notes that in laser physics, active participation of Russian scientists in international conferences, publications in international prestigious journals, and international grant programmes are replaced by closedness, secrecy, and work for the defence industry.
It would seem that Western science has an alternative: China and other Asian countries. Egor Pritotsky doubts that they can become a real alternative.
– Such a sharp turn of Western science (scientific institutes of Europe and America) away from us and us from Western science towards Asian countries, primarily China, is not a very good decision,” he believes. – I have a colleague who is recruiting staff for a laboratory in Shanghai. He is very interested in it, China today remains virtually the only possible supplier of high-quality optics, in particular diffraction gratings, which he needs. But I personally, as well as many of my colleagues, do not see myself in Shanghai. There is a good laser institute there, all the necessary equipment, both Chinese-made and European. Good scholarship, interesting projects.
But the conditions are unacceptable for me. I have to come to Beijing, live there for six months, learn Chinese, pass an exam, and only then start working in Shanghai and move my family there. I am not ready to part with my family for such a long time. Besides, a different mentality, the experience of the COVID-19 epidemic and the limitations of the internet are discouraging.
Our interlocutor from the INP also does not see working in China as an alternative. He hopes that all these problems are temporary and that after the change of power (“it can’t last long”) all the lost ties, primarily in science, will be quickly restored. In the meantime, access to foreign scientific journals and the possibility to participate in conferences without affiliation remain.
Professor Ebeling from the European XFEL does not rule out the possibility of Russian scientists working without Russian affiliation:
– Scientists working at Russian institutions are indeed currently unable to participate in experiments at European XFEL and other facilities. But Russian scientists working at institutions outside Russia continue to work at European XFEL and contribute to our scientific results. We also continue to work with graduate students from Russia. We have had fruitful co-operation with Russian scientists in the past and their contribution to European XFEL has been significant.
P.S. Why most of the interlocutors in the article are anonymous
During the preparation of this article, we contacted many experts, both those personally known to us and those whose names are mentioned in numerous interviews on similar topics, in scientific articles or on the websites of various institutes. Most of the recipients (both in Russia and Germany) simply ignored our questions and requests for interviews. Those who agreed to talk to us anonymously explained to us this behaviour of their colleagues.
– When I give an interview as an employee of European XFEL, I speak on behalf of the whole institute. This means that I have to get written permission from my superiors and perhaps find out their position on certain issues. What I have told you is my personal position. And the institute may not agree with it. To be honest, I simply don’t have the time or inclination to get involved in this bureaucratic procedure,” says a European XFEL employee.
– You are raising a very sensitive and controversial topic,” explains his colleague. – Every word you say on such a topic would weigh too much and could be misinterpreted. I am a scientist and I don’t want to play these diplomatic games.
– It is probably unpleasant, but quite expected,” says their Russian colleague. – Look at what and what kind of cases are brought in Russia, including against scientists. Your publication will certainly not solve the problem, but the person who gave the interview may well face these problems. Why take the risk? It would be easier for most people to just ignore you.
You can support the work of T-invariant by subscribing to our Patreon and choosing a convenient donation amount.
Text: Yulia Chernaya
Yulia Chernaya 4.10.2024