From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “Nuclear fusion – European joint experiment achieves energy record”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

2.8.24
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

The Joint European Torus [JET] tokamak generator based at the Culham Center for Fusion Energy located at the Culham Science Centre, near Culham, Oxfordshire, England.

At the Joint European Torus (JET) in the UK, a European research team has succeeded in generating 69 megajoules of energy from 0.2 milligrams of fuel. This is the largest amount of energy ever achieved in a fusion experiment.

Fusion power plants are designed to fuse light atomic nuclei, following the example of the sun, in order to harness huge amounts of energy for humanity from very small amounts of fuel. The European research consortium EUROfusion is pursuing the concept of magnetic fusion, which is considered by experts to be the most advanced. With the large-scale experiments ASDEX Upgrade [below] and Wendelstein 7-X [below], the MPG Institute for Plasma Physics (IPP) is driving forward research into this in Germany.

Plasma discharge #104,522: The energy record was achieved in this JET experiment. Photo: UKAEA / EUROfusion.

Fusion power plants are designed to fuse light atomic nuclei, following the example of the sun, in order to harness huge amounts of energy for humanity from very small amounts of fuel. The European research consortium EUROfusion is pursuing the concept of magnetic fusion, which is considered by experts to be the most advanced. With the large-scale experiments ASDEX Upgrade and Wendelstein 7-X, the Max Planck Institute for Plasma Physics (IPP) is driving forward research into this in Germany.

For experiments with the fuel of future power plants (deuterium and tritium), Europe’s scientists operated the JET research facility near Oxford together with the UK Atomic Energy Authority (UKAEA). A new world record was set there on 3 October 2023: 69 megajoules of fusion energy were released in the form of fast neutrons during a 5.2 second plasma discharge. 0.2 milligrams of fuel were required for this. The same amount of energy would have required about 2 kilograms of lignite – ten million times as much. JET thus beat its own record from 2021 (59 megajoules in 5 seconds).

“This world record is actually a by-product. It was not actively planned, but we were hoping for it,” explains IPP scientist Dr Athina Kappatou, who worked for JET as one of nine Task Force Leaders. “This experimental campaign was mainly about achieving the different conditions necessary for a future power plant and thus testing realistic scenarios. One positive aspect, however, was that the experiments from two years ago could also be successfully reproduced and even surpassed.” The latter was the case with the record-breaking experiment. The entire campaign is essential for the future operation of the international fusion plant ITER, which is currently being built in southern France, as well as for the planned European demonstration power plant DEMO. Over 300 scientists and engineers from EUROfusion contributed to these landmark experiments.

ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France.

The graph shows the progress of the deuterium-tritium campaigns at JET: in 1997, high power was achieved for a short time, but in the last energy records in 2021 and 2023 it was also possible to maintain this for several seconds. Graphic: UKAEA / EUROfusion.

The JET record did not achieve a positive energy balance – in other words, more heating energy had to be invested in the plasma than fusion energy was generated. In fact, an “energy gain” is physically impossible with JET and all other current magnetic fusion experiments worldwide. For a positive energy balance, these fusion plants must exceed a certain size, which will be the case with ITER.

The record-breaking experiment (JET pulse #104522) in the autumn was one of the last ever at JET. After four decades the facility ceased operations at the end of 2023.

Fusion Energy Record at JET.

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply” near the bottom of the post.

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Please help promote STEM in your local schools.

Stem Education Coalition

The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE) is a physics institute for the investigation of plasma physics, with the aim of working towards fusion power. The institute also works on surface physics, also with focus on problems of fusion power.

The IPP is an institute of the MPG Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

ASDEX tokamak at MPG Institute for Plasma Physics.

Wendelstein 7-X fusion device at MPG Institute for Plasma Physics (IPP) in Greifswald (DE) 2011.

It also cooperates with the ITER and JET projects.

MPG Society for the Advancement of Science [MPG Gesellschaft zur Förderung der Wissenschaften e. V.] is a formally independent non-governmental and non-profit association of German research institutes founded in 1911 as the Kaiser Wilhelm Society and renamed the Max Planck Society in 1948 in honor of its former president, theoretical physicist Max Planck. The society is funded by the federal and state governments of Germany as well as other sources.

According to its primary goal, the MPG Society supports fundamental research in the natural, life and social sciences, the arts and humanities in its 83 (as of January 2014) MPG Institutes. The society has a total staff of approximately 17,000 permanent employees, including 5,470 scientists, plus around 4,600 non-tenured scientists and guests. Society budget for 2015 was about €1.7 billion.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the MPG Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the MPG Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society very highly in the world for science research, and very highly in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

The MPG Society consists of over 80 research institutes. In addition, the society funds a number of MPG Research Groups (MPRG) and International MPG Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University focusing on neuroscience.
The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.

Internally, MPG Institutes are organized into research departments headed by directors such that each MPI has several directors, a position roughly comparable to anything from full professor to department head at a university. Other core members include Junior and Senior Research Fellows.

In addition, there are several associated institutes:

International Max Planck Research Schools

Together with the Association of Universities and other Education Institutions in Germany, the MPG Society established numerous International MPG Research Schools (IMPRS) to promote junior scientists:

• Cologne Graduate School of Ageing Research, Cologne
• International Max Planck Research School for Intelligent Systems, at the Max Planck Institute for Intelligent Systems located in Tübingen and Stuttgart
• International Max Planck Research School on Adapting Behavior in a Fundamentally Uncertain World (Uncertainty School), at the Max Planck Institutes for Economics, for Human Development, and/or Research on Collective Goods
• International Max Planck Research School for Analysis, Design and Optimization in Chemical and Biochemical Process Engineering, Magdeburg
• International Max Planck Research School for Astronomy and Cosmic Physics, Heidelberg at the MPI for Astronomy
• International Max Planck Research School for Astrophysics, Garching at the MPI for Astrophysics
• International Max Planck Research School for Complex Surfaces in Material Sciences, Berlin
• International Max Planck Research School for Computer Science, Saarbrücken
• International Max Planck Research School for Earth System Modeling, Hamburg
• International Max Planck Research School for Elementary Particle Physics, Munich, at the MPI for Physics
• International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, Marburg at the Max Planck Institute for Terrestrial Microbiology
• International Max Planck Research School for Evolutionary Biology, Plön at the Max Planck Institute for Evolutionary Biology
• International Max Planck Research School “From Molecules to Organisms”, Tübingen at the Max Planck Institute for Developmental Biology
• International Max Planck Research School for Global Biogeochemical Cycles, Jena at the Max Planck Institute for Biogeochemistry
• International Max Planck Research School on Gravitational Wave Astronomy, Hannover and Potsdam MPI for Gravitational Physics
• International Max Planck Research School for Heart and Lung Research, Bad Nauheim at the Max Planck Institute for Heart and Lung Research
• International Max Planck Research School for Infectious Diseases and Immunity, Berlin at the Max Planck Institute for Infection Biology
• International Max Planck Research School for Language Sciences, Nijmegen
• International Max Planck Research School for Neurosciences, Göttingen
• International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen
• International Max Planck Research School for Marine Microbiology (MarMic), joint program of the Max Planck Institute for Marine Microbiology in Bremen, the University of Bremen, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, and the Jacobs University Bremen
• International Max Planck Research School for Maritime Affairs, Hamburg
• International Max Planck Research School for Molecular and Cellular Biology, Freiburg
• International Max Planck Research School for Molecular and Cellular Life Sciences, Munich
• International Max Planck Research School for Molecular Biology, Göttingen
• International Max Planck Research School for Molecular Cell Biology and Bioengineering, Dresden
• International Max Planck Research School Molecular Biomedicine, program combined with the ‘Graduate Programm Cell Dynamics And Disease’ at the University of Münster and the Max Planck Institute for Molecular Biomedicine
• International Max Planck Research School on Multiscale Bio-Systems, Potsdam
• International Max Planck Research School for Organismal Biology, at the University of Konstanz and the Max Planck Institute for Ornithology
• International Max Planck Research School on Reactive Structure Analysis for Chemical Reactions (IMPRS RECHARGE), Mülheim an der Ruhr, at the Max Planck Institute for Chemical Energy Conversion
• International Max Planck Research School for Science and Technology of Nano-Systems, Halle at Max Planck Institute of Microstructure Physics
• International Max Planck Research School for Solar System Science at the University of Göttingen hosted by MPI for Solar System Research
• International Max Planck Research School for Astronomy and Astrophysics, Bonn, at the MPI for Radio Astronomy (formerly the International Max Planck Research School for Radio and Infrared Astronomy)
• International Max Planck Research School for the Social and Political Constitution of the Economy, Cologne
• International Max Planck Research School for Surface and Interface Engineering in Advanced Materials, Düsseldorf at Max Planck Institute for Iron Research GmbH
• International Max Planck Research School for Ultrafast Imaging and Structural Dynamics, Hamburg

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

Among others:
• Max Planck Institute for Neurobiology of Behavior – caesar, Bonn
• Max Planck Institute for Aeronomics in Katlenburg-Lindau was renamed to Max Planck Institute for Solar System Research in 2004;
• Max Planck Institute for Biology in Tübingen was closed in 2005;
• Max Planck Institute for Cell Biology in Ladenburg b. Heidelberg was closed in 2003;
• Max Planck Institute for Economics in Jena was renamed to the Max Planck Institute for the Science of Human History in 2014;
• Max Planck Institute for Ionospheric Research in Katlenburg-Lindau was renamed to Max Planck Institute for Aeronomics in 1958;
• Max Planck Institute for Metals Research, Stuttgart
• Max Planck Institute of Oceanic Biology in Wilhelmshaven was renamed to Max Planck Institute of Cell Biology in 1968 and moved to Ladenburg 1977;
• Max Planck Institute for Psychological Research in Munich merged into the Max Planck Institute for Human Cognitive and Brain Sciences in 2004;
• Max Planck Institute for Protein and Leather Research in Regensburg moved to Munich 1957 and was united with the Max Planck Institute for Biochemistry in 1977;
• Max Planck Institute for Virus Research in Tübingen was renamed as Max Planck Institute for Developmental Biology in 1985;
• Max Planck Institute for the Study of the Scientific-Technical World in Starnberg (from 1970 until 1981 (closed)) directed by Carl Friedrich von Weizsäcker and Jürgen Habermas.
• Max Planck Institute for Behavioral Physiology
• Max Planck Institute of Experimental Endocrinology
• Max Planck Institute for Foreign and International Social Law
• Max Planck Institute for Physics and Astrophysics
• Max Planck Research Unit for Enzymology of Protein Folding
• Max Planck Institute for Biology of Ageing

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “Why artificial intelligence is gaining importance in fusion research”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

10.25.23
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

ASDEX Upgrade fusion experiment at IPP in Garching: Artificial intelligence can control the plasma state and find measurement errors in experiments.
Credit: Jan Hosan/MPG Institute for Plasma Physics.

Software tools like ChatGPT made machine learning and AI popular worldwide this year. At the Max Planck Institute for Plasma Physics (IPP), researchers have been successfully developing such algorithms for science for some time.

Fusion reactions take place in plasmas with temperatures of many millions of degrees Celsius, i.e. in states of matter with charged particles (ions and electrons). On the way to a fusion power plant, it is of central importance to be able to generate certain plasma states in a targeted manner. Whether this can be achieved in an experiment can only ever be determined by indirect measurements – and that is anything but trivial. This is because a plasma is a highly complex, inhomogeneous and constantly changing entity that is also invisible to the human eye in the essential areas. That’s why experimental facilities like ASDEX Upgrade and Wendelstein 7-X are surrounded by an armada of high-tech measuring instruments that generate several gigabytes of measurement data during every second of a plasma discharge.

In order to be able to evaluate these enormous amounts of data, machine learning (ML) methods are increasingly being used. After all, that is precisely the strength of artificial intelligence (AI): If you feed it enough training data, it can recognize patterns in gigantic amounts of data and derive principles from them.

“We have built up quite a bit of expertise in this field at IPP over the past few years,” explains working group leader Dr. Udo von Toussaint. “And the number of researchers at the institute developing AI algorithms continues to grow.” The most recent example of the IPP’s successes: when the journal Contributions to Plasma Physics published a special issue on “Machine learning methods in plasma physics” in June with important current work on this topic, three of twelve articles came from the IPP. Dr von Toussaint was part of the editorial team for the issue.

Finding and correcting fundamental measurement errors

One of these papers deals with a fundamental problem of experimental physics that occurs particularly frequently in plasma physics: how to detect “outliers” in measurements – i.e. measured values that must be sorted out so that they do not falsify the result. In fusion experiments, for example, they often occur because the neutrons released in the process unintentionally hit diagnostic imaging instruments and cause results that have nothing to do with the physical phenomenon actually being studied.

Doctoral student Katharina Rath (IPP, Ludwig-Maximilians-Universität Munich) developed an algorithm for robust data analysis in a team with other researchers. The challenge: In simple experiments, outliers can usually be detected with the naked eye because they do not fit into the series of values; in plasma physics, however, multi-dimensional data clouds of measured values arise that defy simple assessment. Classical training strategies in machine learning also have problems dealing with outliers. “It is the strength of the IPP to develop strategies here that nevertheless work. We succeeded in this work with the help of so-called Student t-processes,” says Udo von Toussaint. What’s more, the algorithm should also be able to estimate missing measuring points in the future. In extreme cases, it could even be possible, for example in the event of a temporary failure of one of the many measuring devices, to interpolate its missing results from the values of the other diagnostics.

AI to control the plasma state

Another groundbreaking work in the field of machine learning, which has now been published by IPP and other researchers, deals with the live detection of the state of plasma equilibrium in stellarators such as Wendelstein 7-X. The aim is to achieve this ideal state of plasma equilibrium. In general, this ideal state of the plasma should be reached and maintained. “Because we cannot see the plasma as a whole, we have to rely here on derived measurands such as magnetic field strength, luminosity effects and temperature measurements on the wall of the vessel,” explains Udo von Toussaint. “Nevertheless, there is a very high probability that we are often off by a few centimetres when determining the shape of the plasma.”

Only if the position and shape of the plasma can be determined live during experiments it is possible to establish and maintain a suitable state of equilibrium by readjusting external parameters. For an adapted control, however, it is important to estimate the uncertainty of these data – otherwise the control could react too strongly to erroneous signals. Doctoral student Robert Köberl (IPP, TUM, TU Graz), together with other researchers, developed an algorithm for this purpose that can not only reconstruct the plasma state (the MHD equilibrium) but at the same time determine which error range results from the measured values. “We can’t yet calculate fast, robust and accurate at the same time, because that would clearly overtax the capabilities of today’s computers,” says Dr von Toussaint. “But the calculation of the error range can provide an important basis for decision-making in experiment control.” If the algorithm indicates a high deviation from the plasma equilibrium and a small error range, the experiment control would have to readjust. If, on the other hand, the error range is large, it would doubt the measured value and not react.

Physics and AI: stronger as a team

An increasingly important field is the consideration of existing boundary conditions when training and applying machine learning methods. In plasma physics in particular, there is extensive knowledge about the allowed states of plasmas, since they are subject to energy and momentum conservation, for example. IPP Director Prof. Eric Sonnendrücker (IPP) was recently awarded the Dawson Award for his fundamental work in this field.

However, it is often very difficult to consistently integrate these existing boundary conditions into the commonly used AI/ML methods. Here, IPP scientists Dr. Tomasz Tyranowski and Dr. Michael Kraus were able to significantly improve the long-term stability of plasma simulations for one of the fundamental model systems in plasma physics (Dr. Tyranowski has since followed a call to the University of Twente). It is about the Vlasov model, in which the so-called symplectic equation structure is now correctly taken into account in the AI algorithms.

“These examples show that machine learning methods are often perfectly suited to solving problems in plasma physics,” judges Udo von Toussaint. “But our findings can also help completely different scientific disciplines.” The fact that solutions from AI/ML research can often be used universally was recently demonstrated by the annual MaxEnt conference (International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering), which took place at IPP in Garching in July 2023. This year, artificial intelligence and machine learning were a big topic.

MaxEnt brings together researchers who use probabilistic models – mathematical models based on random variables and their probability distributions – to solve problems from a wide range of disciplines: It’s about materials science and engineering, earthquake probabilities, medicine and, indeed, plasma physics. “We all learn from each other there,” says Udo von Toussaint. And so it happens that AI/ML algorithms from the IPP are also used in the geosciences and meteorology, for example – or vice versa.

Artificial Intelligence and Machine Learning

AI is usually understood as the ability of a computer to react independently to input or information from outside and to learn from it. Machine learning algorithms are an essential component of AI. These are essentially systems that are fed with training data and develop statistical models that enable them to recognise regularities and patterns. Machine learning encompasses many different methods. Its most prominent representatives are artificial neural networks and stochastic processes (such as Gaussian processes). The well-known AI tool ChatGPT is based on neural networks.

Publications:

Contributions to Plasma Physics

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply” near the bottom of the post.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

The MPG Society consists of over 80 research institutes. In addition, the society funds a number of Max Planck Research Groups (MPRG) and International Max Planck Research Schools (IMPRS). The purpose of establishing independent research groups at various universities is to strengthen the required networking between universities and institutes of the Max Planck Society.
The research units are primarily located across Europe with a few in South Korea and the U.S. In 2007, the Society established its first non-European centre, with an institute on the Jupiter campus of Florida Atlantic University (US) focusing on neuroscience.
The MPG Institutes operate independently from, though in close cooperation with, the universities, and focus on innovative research which does not fit into the university structure due to their interdisciplinary or transdisciplinary nature or which require resources that cannot be met by the state universities.

In addition, there are several associated institutes:

International Max Planck Research Schools

Together with the Association of Universities and other Education Institutions in Germany, the Max Planck Society established numerous International Max Planck Research Schools (IMPRS) to promote junior scientists:

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “An alternative for the energy supply of ASDEX Upgrade”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

8.22.23 [Just found this.]
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

If the flywheel generator EZ2 at the MPG Institute for Plasma Physics (IPP) (DE) no replacement would be available. Supercapacitors could be a solution.

ASDEX tokamak at MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE).

Electrical engineer Antonio Magnanimo describes a new concept for generating electricity for the IPP tokamak ASDEX Upgrade using supercapacitors. He developed this as part of his doctoral thesis at IPP which he finished in June. In the meantime, Dr Magnanimo has taken up a position at MIT.

The 4-SM demonstrator: the rack is composed of four independent sections containing each a submodule. The output terminals of each submodule are on the right side of the rack and they can be connected either via cables or copper bars (as in the photo). The lowest submodule (SM 1) is connected to the output power cables connecting the prototype with the test load. Credit: Antonio Magnanimo /MPG Institute for Plasma Physics.

The electrical power of the tokamak experiment ASDEX Upgrade at the MPG Institute for Plasma Physics (DE) is provided by three independent flywheel generators. They are charged up before the start of each experiment with up to 15 megawatts for several minutes. The stored energy is then used to satisfy the high-power needs during an experiment – called plasma pulse – of up to 450 megawatts. The three flywheel generators have been built only for this experiment more than 30 years ago. The largest one, EZ2 (built in 1973), could not be replaced in case of a major fault. Since the flywheel generators market has changed in the last decades, there exist no present company able to produce nowadays a flywheel generator with this size. Therefore, the development of an alternative power supply system with high power and energy and fully controllable output is planned.

The first idea consisted in conducting a feasibility study on the adoption of several smaller flywheel generators in parallel to reach the same power required by EZ2, but the outcome of this research was not successful due to synchronization issues. Since modern flywheel generators seem to be not an option, IPP decided to search for a different technology with similar energy and power density. Common batteries have higher energy density but too low power density, leading to a huge excess of (unused) energy in order to reach the required power; capacitors on the other hand have a very high power density, but a low energy density leading to an extreme expensive and large solution. For these reasons it has been decided to investigate on the upcoming technology of supercapacitors, which fits with flywheel generators in terms of both energy and power density. In order to deliver the required power to ASDEX Upgrade coils however supercapacitors are not enough, and a proper power converter is necessary taking into account a suitable safety concept.

How the idea for a modular system came about.

Submodule experimental setup Photo: Antonio Magnanimo/MPG Institute for Plasma Physics.

There exist already some supercapacitors-based power supplies for fusion applications, but all those systems use supercapacitors in a most simple configuration, meaning as a single passive bank integrated into a single powerful converter controlling the full energy flux. This would be the equivalent supercapacitor-based solution of a flywheel generator which would solve the current problem of replacing EZ2, but on the other hand it would present its main concern: supercapacitors are sensitive against overvoltage and they cause an electric short circuit in case of a failure. If this happens, the energy of thousands of parallel or serial connected cells could be injected into the faulty cell which is equivalent to a huge explosion. Loss of the full device and millions of Euro investment would be the consequence. This concern led to the search of a modular system and from here the idea of combining together supercapacitors with the modular multilevel converter was born: this converter has several identical small-scale power converter modules (submodules) that can control individually small scale supercapacitor modules; in this way in case of failure of a single supercapacitor module or submodule, the whole converter would not be affected or it could even continue the operation with a proper fault management. Right now there exists no similar solution as the one described in my dissertation on the free market, and for this reason it has been decided to keep the design as much flexible as possible, so that in case of need it can be adapted for different tokamak loads (poloidal field coils, heating systems…) or even non-fusion applications (e.g. electrical grid stability).

Working principle of supercapacitors

Supercapacitors are well known for their balanced ratio of energy and power density. Thanks to their high power density, supercapacitors have several potential applications, but they are mainly used for Uninterruptible Power Systems (UPS) and Hybrid Electric Vehicles (HEV). However, this technology does not provide enough energy for use in purely electric cars without being combined with a battery system.

Fundamentally a supercapacitor consists of two metal plates separated by an insulator, just like an ordinary capacitor. The separator, however, is porous and is soaked in an electrolyte. Since the ions of the electrolyte can move freely through the separator, positive and negative ions move in opposite directions and cling to their respective electrodes. The electrolyte acts as an (ion) conductor. The important feature in supercapacitors is that the inner surface of each electrode is not a smooth surface but it is rather padded with activated (porous) carbon. This results in a surface area that is up to 100.000 times as large as the surface area of an ordinary capacitor. The large surface area of a supercapacitor, however, is not the only novel feature of the device. Since charges are carried by ions attached to the inner surfaces of the electrodes these cannot be neutralised by electrons up to voltages of a few volts, the distance between the positive and negative charges at each electrode is on the order of a few Angstrom (one Angstrom corresponds approximately to the typical distance between atoms in a crystal compound and is the ten-millionth part of a millimetre). By maximizing the surface area and minimizing this distance, supercapacitors achieve extremely high values of capacitance (thousands of Farad for each cell). If the distance between the electrodes would be a millimeter, the electrode area of a single cell would have to be of the size of Germany. Because it is only one Angstrom, the area size is equal to approximately 30 soccer fields.

The use of supercapacitors for higher voltages is possible only by making use of supercapacitors modules, composed by several cells connected in serial. However, it is usually necessary to introduce active or passive components to balance evenly the modules internal voltages, thus increasing the global costs and complexity. In order to mitigate these inconveniences, manufacturers provide assembled modules reaching hundreds of Volts and Farad.

Applications of supercapacitors in fusion research.

One of the first fusion applications where supercapacitors have been used is PROTO- SPHERA in Italy, a “Spherical Tokamak” with the scientific goal to get rid of the central transformer. Another example is the Divertor Tokamak Test (DTT) facility, currently under construction in Italy. DTT is a large fusion experiment expected to provide relevant contributions to ITER and DEMO by investigating the problem of the power exhaust. DTT has six modules composing the central solenoid and six poloidal magnets, all superconductive and supplied by independent circuits via supercapacitors.

The power supply systems at PROTO- SPHERA and at DTT are both designed in such a way that in case of a major failure, the entire supercapacitor system would be damaged – analogous to the failure of a flywheel at ASDEX Upgrade. A solution that could replace a flywheel generator at IPP has to be capable to continue the operation even in case of local small faults, due to the importance of the experiments conducted and the much higher involved stored energy.

“My concept for ASDEX upgrade is based on a modular multilevel converter (MMC). The MMC has received considerable attention since the beginning of this century and it has become one of the most attractive converters for high-power applications such as High-Voltage DC (HVDC) converters or railway power supplies, but also fusion devices’ power supplies. This converter, thanks to the discrete-leveled output voltage and its identical submodules by which it is composed, represents a promising alternative to replace the flywheel generator EZ2. The modular concept separates the total stored energy into thousands of smaller storages which can be kept separated even in case of fault.

As part of my dissertation, I built a small-scale demonstrator (1:550) to validate the designed converter. It is composed by four identical submodules, which can be connected in serial, parallel or combined serial/parallel connection. The aim of the demonstrator was to verify the results of the simulations I had previously carried out with the PLECS software tool. The supercapacitor module is a custom solution built for this specific project from the SPSCAP company. The module is composed of 48 supercapacitor cells in series, each of which has a capacitance of 3200 F and 2.7 V of nominal voltage. The module has no active electronics in it and it is treated as a passive single component, even though it presents a passive balancing system for its internal cells.

After having properly designed and tested the single submodule, three additional submodules have been built in order to test them in serial, parallel and combined serial/parallel operation. The serial operation was used to test the developed control strategy, the parallel was crucial for the scalability of the system and their combination validated the integration of both aspects into a single device.”

A system for ASDEX upgrade would have to consist of 2200 submodules

All tests confirmed the results of the simulations. Therefore, the developed model can be used as a reference to scale the prototype to a larger size device. An estimation leads to 2200 total modules required to replace the flywheel generator EZ2. With about 400 cubic-meters the supercapacitor design would require approximately the same volume that is occupied by the EZ2.

Even though the main goals of the project have been achieved, there still are some critical points to be faced before proceeding with the building up of a full-scale converter:

Power stage filter optimization: the designed power stage filter is a laboratory prototype. Therefore it is not optimized both in size and cost, and a proper optimization is recommended in case of scaling up of the converter;
Losses reduction: due to the main application for which this prototype has been built, losses minimization has been not the main focus of the work. In case of usage of the proposed converter for applications where low losses are a priority, this has to be kept into account;
Control optimization: one of the main limits of the propotype control comes from the adopted standard microcontrollers and by upgrading them the speed of the control can be significantly improved.
Finalization of the communication and the safety system for permanent operation at full size.
Safe power grid connection for a probably stepwise growing device.
Defining if or which other components should be upgraded will be a task that future designers should face depending on the application of the converter.

The construction of a demonstrator was possible in the laboratory at IPP. In order to further develop the concept towards 2200 modules, cooperation with industrial partners will be necessary.

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply” near the bottom of the post.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “New discovery points the way to more compact fusion power plants”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

4.11.23
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

A magnetic cage keeps the more than 100 million degree Celsius hot plasmas in nuclear fusion devices at a distance from the vessel wall so that they do not melt.

Now researchers at the Max Planck Institute for Plasma Physics (IPP) have found a way to significantly reduce this distance. This could make it possible to build smaller and cheaper fusion reactors for energy production. The work was published in the journal Physical Review Letters [below].

Plasma vessel of ASDEX Upgrade. The circular channel at the bottom contains the divertor. Credit: MPI for Plasma Physics/Volker Rohde.

The international experimental reactor ITER, which is currently being built in southern France, represents the most advanced way to generate energy in a fusion power plant.

The design follows the tokamak principle, i.e., a fusion plasma at more than 100 million degrees is confined in a magnetic field shaped like a donut. This concept prevents the hot plasma from coming into contact with the enclosing wall and damaging it. The ASDEX Upgrade tokamak experiment at IPP in Garching near Munich serves as a blueprint for ITER and later fusion power plants. Important elements for ITER were developed here. And plasma operating conditions and components for later power plants can already be tested today.

The hot plasma moves closer to the divertor

A central element of ASDEX Upgrade and all modern magnetic fusion facilities is the divertor. This is a part of the vessel wall that is particularly heat-resistant and requires an elaborate design. “At the divertor arrives the heat from the plasma at the wall. In later power plants, the fusion product helium-4 will also be extracted there,” Prof. Ulrich Stroth explained, head of the Plasma Edge and Wall Division at IPP. “In this region, the wall load is particularly high.” The divertor tiles of ASDEX Upgrade and also of ITER are therefore made of tungsten, the chemical element with the highest melting temperature of all (3422° C).

Without countermeasures, 20 percent of the fusion power of the plasma would reach the divertor surfaces. At approx. 200 megawatts per square metre, that would be roughly the same conditions as on the surface of the sun. However, the divertor in ITER and also future fusion power plants will only be able to cope with a maximum of 10 megawatts per square metre. For this reason, small amounts of impurities (often nitrogen) are added to the plasma. These extract most of its thermal energy by converting it into ultraviolet light. Nevertheless, the plasma edge (the separatrix) must be kept at a distance from the divertor to protect it. In ASDEX Upgrade until now, this has been at least 25 centimetres (measured from the lower plasma tip – the X-point – to the edges of the divertor).

X-point radiator opens up new possibilities for fusion reactor design

This cross-section through one half of the plasma vessel of ASDEX Upgrade shows in bright colours the electromagnetic radiation in the UV spectral range by the X-point radiator. The divertor is shown schematically below. The red line indicates the plasma edge (separatrix), which in this case was placed very close to the divertor. This could allow the construction of smaller and cheaper plasma vessels if their shape is adapted accordingly. The electromagnetic radiation was measured with a bolometer. Graphic: MPI for Plasma Physics.

Now, researchers at IPP have succeeded in reducing this distance to fewer than 5 centimetres without damaging the wall. “We specifically use the X-point radiator for this, a phenomenon we discovered about a decade ago during experiments at ASDEX Upgrade,” IPP researcher Dr Matthias Bernert said. “The X-point radiator occurs in specifically shaped magnetic cages when the amount of added nitrogen exceeds a certain value.” This leads to formation of a small, dense volume that radiates particularly strongly in the UV range. “Such impurities give us somewhat poorer plasma properties, but if we set the X-point radiator to a fixed position by varying the nitrogen injection, we can run the experiments at higher power without damaging the device/divertor,” Dr Bernert explained.

In camera images from the vacuum vessel, the X-point radiator (XPR for short) can be seen as a blue glowing ring in the plasma, as it also emits some visible light in addition to the UV radiation. IPP researchers have recently intensively investigated the XPR.

The X-point radiator emits not only UV light but also visible blue light in a ring-shaped area above the divertor. The left picture shows a camera image (below the normal red glow of the cold plasma edge). On the right is a numerical simulation of the X-point radiator phenomenon.

Nevertheless, chance also played a role in the current discovery: “We accidentally moved the plasma edge much closer to the divertor than we had intended,” IPP physicist Dr Tilmann Lunt said. “We were very surprised that ASDEX Upgrade coped with this without any problems.” Because the effect could be confirmed in further experiments, the researchers now know: when the X-point radiator is present, significantly more thermal energy is converted into UV radiation than previously assumed. The plasma then radiates up to 90 percent of the energy in all directions.

Fusion power plants could be built more compact and cheaper

This leads to conclusions that could be very favourable for the construction of future fusion power plants:

Divertors can be built smaller and technologically much simpler than before (Compact Radiative Divertor).
Because the plasma moves closer to the divertor, the vacuum vessel volume can be better utilised. Initial calculations show that if the vessel were optimally shaped, it would be possible to almost double the plasma volume while maintaining the same dimensions. This would also increase the achievable fusion power. But the researchers first have to verify this in further experiments.

In addition, the use of the X-point radiator also helps against edge localised modes (ELMs): violent energy eruptions at the plasma edge that recur at regular intervals and expel about a tenth of the plasma energy towards the wall. ITER and future fusion reactors would be damaged by such eruptions.

“We are dealing with a significant discovery in fusion research,” is therefore also the verdict of IPP Division Director Ulrich Stroth. “The X-point radiator opens up completely new possibilities for us in the development of a power plant. We will further investigate the theory behind it and try to understand it better by new experiments at ASDEX Upgrade.” The Garching tokamak will soon be ideally equipped for this: By summer 2024, it will be provided with a new upper divertor. Its special coils will make it possible to deform the magnetic field close to the divertor freely and thus also optimize the conditions for the X-point radiator.

Physical Review Letters

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “Wendelstein 7-X reaches milestone – Power plasma generated with gigajoule energy turnover over eight minutes”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

2.22.23

Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

In 2023, an energy turnover of 1 gigajoule should be achieved. Now the researchers have even managed 1.3 gigajoules – and a new record for the discharge time of Wendelstein 7-X: The hot plasma could be maintained for eight minutes.

During the three-year renovation work, which ended last summer, Wendelstein 7-X was mainly equipped with water cooling of the wall elements and an extended heating system. The latter can now couple twice as much power into the plasma as before. Since then, the nuclear fusion experiment can be operated in new parameter ranges. “We are now approaching ever higher energy values,” explains Prof. Dr. Thomas Klinger, Head of Stellarator Dynamics and Transport at the MPG Institute for Plasma Physics (IPP) in Greifswald. “We have to proceed step by step so as not to overload and damage the system.”

On February 15, 2023, the researchers reached a new milestone: For the first time, they were able to achieve an energy turnover of 1.3 gigajoules in this plant. This increased the best value from the time before the conversion (75 megajoules) by a factor of 17. The energy turnover results from the coupled heating power multiplied by the duration of the discharge. Power plant operation is only possible if it is possible to continuously couple large amounts of energy into the plasma and dissipate the resulting heat again.

Plasma discharge lasted eight minutes

The greatest heat flows in Wendelstein 7-X are conducted via particularly heat-resistant, so-called divertor baffle plates. They are part of the inner wall, which has been cooled by a network of a total of 6.8 kilometers of water pipes since the conversion. No other fusion research facility in the world today has such a comprehensively cooled wall. The plasma heating consists of three components, namely the newly installed ion heating, the heating by neutral particle injection and the microwave electron heating. For the current record, the electron microwave heating was particularly important, because only it is able to couple large powers over periods of several minutes. The energy turnover of 1.3 gigajoules was achieved with an average heating output of 2.7 megawatts, with the discharge lasting over 480 seconds – this is also a new record for Wendelstein 7-X and one of the best in the world. Before the conversion, Wendelstein 7-X achieved maximum plasma times of 100 seconds with significantly lower heating power.

Within a few years, according to the plan, the energy turnover at Wendelstein 7-X is to be increased to 18 gigajoules, whereby the plasma is then to be kept stable for half an hour.

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “Nuclear fusion simulation to pioneer transition to exascale supercomputers”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

12.19.22
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

The EU Commission is providing 2.14 million euros in funding to take the GENE simulation code developed at the MPG Institute for Plasma Physics (IPP) to a new level. By using exascale supercomputers, it enables digital twins of nuclear fusion experiments such as ITER in future.

IPP, the Max Planck Computing and Data Facility (MPCDF) and the Technical University of Munich will work together on the project.

Plasma physics has been one of the most important drivers for the further development of supercomputers since the 1960s. This is because plasmas are highly complex entities that cannot be detected with simple physical models. Almost the entire universe consists of such plasmas, which are extremely dynamic mixtures of predominantly charged particles (ions and electrons). Our sun and all other stars generate energy from this through nuclear fusion. Researchers need supercomputers to make this process usable on earth and to better understand the processes in the universe.

GENE computer simulation of plasma turbulence in the Garching tokamak experiment ASDEX Upgrade.

With regard to future fusion power plants, corresponding losses of plasma particles and energy must be minimized.

The MPG Computing and Data Facility (MPCDF) in Garching was launched in 1960 and the National Energy Research Supercomputer Center (NERSC) in the USA in 1974 as tools for plasma research.

___________________________________________________________
MPG Computing and Data Facility (MPCDF) at Garching (DE)

The Ada supercomputer at the MPG Computing and Data Facility in Garching (DE).

HYDRA supercomputer at the Max Planck Computing and Data Facility in Garching bei München (DE)

MPG Supercomputer Raven at MPG Supercomputer Center and Data Facility Garching (DE).

MPG Supercomputer Cobra at MPG Supercomputer Center Garching (DE).

___________________________________________________________

National Energy Research Scientific Computing Center (NERSC) at The DOE’s Lawrence Berkeley National Laboratory

Cray Cori II supercomputer at National Energy Research Scientific Computing Center(US) at DOE’s Lawrence Berkeley National Laboratory(US), named after Gerty Cori, the first American woman to win a Nobel Prize in science.

NERSC Hopper Cray XE6 supercomputer, named after Grace Hopper, One of the first programmers of the Harvard Mark I computer.

Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supercomputer.

NERSC is a DOE Office of Science User Facility.

When the US supercomputer Roadrunner at The DOE’s Los Alamos National Laboratory was the first to break the petascale barrier in 2009 (i.e. it was able to perform more than 10^15 = one quadrillion computing operations per second), a plasma simulation code called VPIC played an important role.

Supercomputer Roadrunner at The DOE’s Los Alamos National Laboratory.

On the way to exascale supercomputers

In the forthcoming leap in high-performance computing, plasma modelling will again be among the pioneering applications: It is about the launch of the first exascale computers in Europe. By definition, these can perform at least one trillion computing operations per second (1 quintillion = 10^18, written out as 1 with 18 zeros). From 2024 onwards, there will be supercomputers in Europe that exceed this threshold. The European Commission is providing a total of more than seven million euros to prepare four simulation codes for plasmas for the exascale era.

A total of 2.14 million euros of the funding sum will go to the Garching site near Munich (the German Federal Ministry of Education and Research is providing half of the funding amount): The MPG Institute for Plasma Physics (IPP), the MPG Computing and Data Facility (MPCDF) and the Technical University of Munich (Department of Computer Science) will use it to jointly raise the GENE code to a new level from January 2023. GENE (Gyrokinetic Electromagnetic Numerical Experiment) is an open-source code that is used worldwide, especially for research into nuclear fusion plasmas. It is therefore used wherever researchers are working on generating energy on earth, following the example of the sun.

Comparison of the sizes of ASDEX Upgrade (Garching, Germany; pictured front left), JET (Culham, UK; front right) and ITER (Cadarache, France, back). The computational effort increases about 10-fold from one experiment to the next.

Predicting fusion experiments for the first time

“With today’s capabilities, GENE can already explain the physical causes of experimental results that we achieve, for example, with our fusion experiment ASDEX Upgrade at IPP,” Prof. Frank Jenko explained, Head of Tokamak Theory at IPP in Garching. He wrote the first version of GENE in 1999 and has been steadily developing the code with international teams ever since. “With an exascale version of GENE, we are now taking the step from interpretation to prediction of experiments. We want to create a virtual fusion plasma, the digital twin of a real plant, so to speak,” Jenko explained the goal.

He and his cooperation partners are also involved with ITER [above], the largest fusion experiment in the world, which is currently being built in Cadarache in southern France. ITER is supposed to generate ten times more fusion power than the amount of heating power that needs to be put into it. The facility is designed as a preliminary stage of a future fusion power plant that will then actually supply electricity. To achieve this goal, scientists will have to adjust a variety of experimental parameters at ITER to find the most favorable combination, which would probably take many years through trial and error alone. An optimized GENE code should significantly speed up fusion research. With it, scientists will be able to calculate configurations in advance and rule out many others in advance.

Why is the switch to exascale computers so complex?

“Unfortunately, it is not enough to simply transfer the previous programmes to the new computers,” Prof. Jenko said. “Performance leaps in new supercomputers are largely made possible by new hardware architectures today. Only if we adapt our codes to this can we really calculate faster.”

Prof. Jenko illustrates the task with the processing of files in the analogue world. “If the task is to evaluate ten thematically closed file folders, ten people can probably do it ten times faster than one. But if suddenly 10,000 people are available for the ten folders, that only brings something if I completely reorganize and divide the work,” Prof. Jenko explained. It becomes even more complicated when the 10,000 people have different skills that need to be used optimally. This is also the case if the evaluation of some folders depends on the results obtained from other folders.

The researchers face comparable tasks in the transition to exascale computers: “Today’s supercomputers achieve their performance increase by handling more and more computing tasks in parallel and by increasingly using graphics processors in addition to classical processors, both of which, however, have different strengths,” says Jenko. To prepare the GENE code for future computer generations, his team therefore includes experts who are involved in the design of future hardware generations. Co-design is the name given to this collaboration in the industry.

In the end, not only fusion research will benefit from the project: “With the GENE code, we are pioneers in the transition to exascale computers,” Prof. Jenko stated. “What we learn in the process will also help developers of other programmes.”

About the European Commission’s funding programme

In early 2022, the European Commission published a call for tenders on “Centres of Excellence Preparing Applications in the Exascale Era“. The aim is to prepare applications that are at the forefront of technological development and have a broad user base for use on future European exascale supercomputers. The aim is also to promote a giant leap in answering key scientific questions in this way. The projects are funded half by the EU Commission and half by the nations whose institutions participate.

In response to this call for proposals, an interdisciplinary team was formed under the leadership of KTH Stockholm around the topic of plasma physics, involving not only the IPP but also the MPCDF, the Technical University of Munich and eight other partners from Europe. The corresponding proposal “Pushing Flagship Plasma Simulation Codes to Tackle Exascale-Enabled Grand Challenges via Performance Optimization and Codesign (Plasma-PEPSC)” has now been selected by the European Commission for a four-year funding period (from 1 January 2023) after a detailed review and has been awarded funding of more than seven million euros. Of this, 2.14 million euros will be allocated to the further development of the GENE code. The German Federal Ministry of Education and Research is providing 50 per cent of the funding.

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE) And The Vienna University of Technology [Technische Universität Wien](AT) : “A new solution to one of the major problems of fusion research”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

And

The Vienna University of Technology [Technische Universität Wien](AT)

10.11.22
Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

Current experiments and simulations show how to avoid destructive plasma instabilities in fusion reactors like ITER.

Type-I ELM plasma instabilities can melt the walls of fusion devices. A team of researchers from the Max Planck Institute for Plasma Physics (IPP) and the Vienna University of Technology (TU Wien) found a way to get them under control. Their work is published in the renowned journal Physical Review Letters [below].

Nuclear fusion power plants could one day provide a sustainable solution to our energy problems. That is why research is being carried out worldwide on this method of energy generation, which imitates processes on the sun. For the principle to work on Earth, plasmas must be heated to at least 100 million degrees Celsius in reactors. Magnetic fields enclose the plasma so that the wall of the reactor does not melt. This only works because the outermost centimetres in the magnetically formed plasma edge are extremely well insulated. In this region, however, plasma instabilities, so-called edge localised modes (ELMs), occur frequently. During such an event, energetic particles from the plasma may hit the wall of the reactor, potentially damaging it.

From left to right: Georg Harrer (TU Wien), Lidija Radovanovic (TU Wien), Elisabeth Wolfrum (IPP Garching), Friedrich Aumayr (TU Wien) holding a 3D printed 1:100 model of ITER.

Researchers from the Max Planck Institute for Plasma Physics (IPP) in Garching and from the Vienna University of Technology have now been able to show: There is an operating mode for fusion reactors that avoids this problem. Instead of large, potentially destructive instabilities, one intentionally accepts many small instabilities that do not pose a problem for the reactor’s wall. “Our work represents a breakthrough in understanding the occurrence and prevention of large Type I ELMs,” says Elisabeth Wolfrum, research group leader at IPP in Garching, Germany, and professor at TU Wien. “The operation regime we propose is probably the most promising scenario for future fusion power plant plasmas.” The results have now been published in the journal Physical Review Letters [below] as “Editors’ Suggestion”.

The renaissance of a disregarded mode of operation

In a toroidal tokamak fusion reactor, ultra-hot plasma particles move at high speeds. Powerful magnetic coils ensure that the particles remain confined instead of hitting the reactor wall with destructive force. “However, you don’t want to isolate the plasma perfectly from the reactor wall either; after all, new fuel has to be added and the helium produced during fusion has to be removed,” explains Friedrich Aumayr, professor of Ion & Plasma Physics at the Institute of Applied Physics of TU Wien in Vienna, Austria.

Cross-section of the toroidal tokamak plasma in ASDEX Upgrade; The left picture shows the usual operation regime, where strong instabilities (called Type-I ELMs) occur; right, the new regime of operation, with its more triangular cross section. If at the same time the density of the plasma at the edge is increased, the dangerous Type-I ELMs can be prevented and a quasi-continuous exhaust (QCE) operational regime can be achieved. Credit: G. Harrer & L. Radovanovic, TU Wien.

The details of the dynamics inside the reactor are complicated: The motion of the particles depends on plasma density, temperature and magnetic field. Depending on how one chooses these parameters, different regimes of operation are possible. A long-standing collaboration between the TU Vienna group of Friedrich Aumayr and the IPP Garching group coordinated by Elisabeth Wolfrum now lead to in an operating regime that can prevent the particularly destructive plasma instabilities called “Type-I ELMs”.

Already a few years ago, experiments have shown a recipe against the dangerous Type-I ELMs: the plasma is slightly deformed by the magnetic coils so that its plasma cross-section is no longer elliptical but resembles a rounded triangle. Simultanously, the density of the plasma is increased, especially at the edge. “At first, however, this was thought to be a scenario that only occurs in currently running smaller machines such as ASDEX Upgrade at IPP in Garching and is irrelevant for a reactor,” explains Lidija Radovanovic, who is currently working on her PhD thesis on this topic at TU Wien. “However, with new experiments and simulations, we have now been able to show: The regime can prevent the dangerous instabilities even in parameter ranges foreseen for reactors.”

Like a pot with a lid

Due to the triangular shape of the plasma and the controlled injection of additional particles at the plasma edge, many small instabilities occur – several thousand times per second. “These small particle bursts hit the wall of the reactor faster than it can heat up and cool down again,” says Georg Harrer, lead author of the paper, who received a two-year EUROfusion Researcher Grant from the EU to further study the new operation regime. “Therefore, these individual instabilities do not play a major role for the reactor wall.” But as the team has been able to show through detailed simulation calculations, these mini-instabilities prevent the large instabilities that would otherwise cause damage.

“It’s a bit like a cooking pot with a lid, where the water starts to boil,” Georg Harrer explains. “If pressure keeps building up, the lid will lift and rattle heavily due to the escaping steam. But if you tilt the lid slightly, then steam can continuously escape, and the lid remains stable and doesn’t rattle.” This fusion reactor operation regime can be implemented in a variety of reactors – not only at the ASDEX Upgrade reactor in Garching [below], but also at ITER currently under construction in France, or even in future DEMO fusion plants.

Science paper:
Physical Review Letters

See the full article here .

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

At The Vienna University of Technology [Technische Universität Wien](AT), we have been conducting research, teaching and learning under the motto ‘Technology for people’ for over 200 years. TU Wien has evolved into an open academic institution where discussions can happen, opinions can be voiced and arguments will be heard. Although everyone may have different individual philosophies and approaches to life, the staff, management personnel and students at TU Wien all promote open-mindedness and tolerance.

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “This discovery made ITER possible”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

10.26.22

Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

Forty years ago, physicists at the MPG Institute for Plasma Physics found a new plasma state that could be particularly suitable for energy production: the H-mode. On 8 November 1982, the corresponding paper [Physical Review Letters (below)] was published, giving fusion research a worldwide boost. To this day, the investigation of the H-mode is one of their most important fields of work.

The breakthrough came on a Thursday when – as often before – plasmas with neutral beam heating were to be studied at high temperatures. These plasmas were of a stubborn uniformity. “But in the middle of the series, the important plasma parameters suddenly changed. All the scientists in the ASDEX [below] control room realized that something extraordinary had happened,” Prof. Dr. Friedrich Wagner recalled, who was responsible for this area of research at ASDEX at the time. At first on this 4 February 1982, many believed that they were dealing with “dirty discharges” and large sawtooths, i.e. internal energy relaxations. In fact, Prof. Wagner and his colleagues at the MPG Institute for Plasma Physics (IPP) in Garching made one of the most important discoveries in nuclear fusion research to date: they found the H-mode.

The corresponding article appeared in the journal Physical Review Letters [below] 40 years ago, on 8 November 1982. It ended a long phase of stagnation and disappointment in the fusion community about the usefulness of neutral beam heating. It is true that in the 1970s researchers had been able to heat plasmas to remarkable ion temperatures of seven kiloelectronvolts, which briefly triggered a veritable euphoria. But it soon turned out that the high plasma temperatures were bought by a decrease in energy confinement. It was like heating a room vigorously while simultaneously opening the windows. This plasma behavior posed a threat to the further development of a fusion power plant.

Computer simulation of a Type I ELM lasting 500 microseconds. The image shows a cross-section through the donut-shaped vacuum vessel of a tokamak. Recurrent eruptions form at the edge of the fusion plasma at regular intervals. These ELMs occur when the plasma is operated in the H-mode. The figure is based on calculations with the code JOREK in the publication A. Cathey et al 2020 Nucl. Fusion [below] 60 124007. Credit: A. Cathey, M. Hoelzl/MPG Institute for Plasma Physics.

Many in the fusion community thought the H-mode was a measurement error

Today, this unfavorable operating state is called L-mode (Low-Confinement Mode). Wagner’s discovery at ASDEX, the predecessor of the current Garching experiment ASDEX Upgrade, is called High-Confinement Mode, or H-mode for short. That this was actually a new plasma state was initially disputed. “I went to the Varenna Summer School in Italy in June 1982, where I presented our results publicly for the first time. American colleagues in particular spread the word afterwards that we were not measuring the plasma flow correctly in ASDEX,” Prof. Wagner stated, who later became director at IPP. It was only at the next important symposium in September in Baltimore that he convinced his colleagues after they had “grilled” him in an hour-long discussion beforehand. A little later, they too were able to produce the new plasma state in their facilities.

22 minutes. Prof. Friedrich Wagner tells us how he discovered H-mode.

“The discovery of the H-mode is what made ITER possible in the first place,” Prof. Dr. Elisabeth Wolfrum explained, who continues research on the H-mode at IPP today.

ITER, the largest fusion device in the world, is currently being built in Cadarache in southern France. It is designed to generate ten times more power from fusion plasma than is supplied in heating power. The fact that ITER is modeled on ASDEX and also ASDEX Upgrade is also due to the H-mode. This plasma state first appeared in ASDEX because the plasma in the donut-shaped vacuum vessel of the tokamak type was shaped for the first time not round, but pointed. Physicists call the tip the X-point. This is where excess energy is guided into the diverter, more or less the ash box of a fusion reactor. Today, this design is standard in all fusion facilities that use magnetic fields to confine the plasma.

The H-mode leads to the formation of an insulating layer at the plasma edge

Shortly after the discovery of the H-mode, it was shown at ASDEX why plasmas in this state can confine energy twice as well as in the L-mode. “A very effective insulating layer forms at the outer edge of the plasma,” Prof. Wolfrum explained. “The temperature difference between its outside and the side facing the plasma interior is several million degrees Celsius.” However, the physicists also discovered an unpleasant side effect of the H-mode: violent energy flares – called edge localized modes (ELMs) – occur at the plasma edge at regular intervals. “In ASDEX Upgrade, ELMs are tolerable, but in the much larger ITER they would be so strong that they would melt the wall of the vacuum vessel,” Prof. Wolfrum said. ITER is being built with four times the vessel radius of ASDEX Upgrade, which would probably result in ELM energies ten to 15 times as strong as in ASDEX Upgrade. Therefore, suppression of these perturbations is one of the most important areas of research in fusion physics.

Computer simulation of Type I ELMs occurring periodically and ejecting particles and heat from the plasma. The figure shows a cross-section through the donut-shaped vacuum vessel of a tokamak. These recurring eruptions form at regular intervals at the edge of the fusion plasma. ELMs occur when the plasma is operated in the H-mode. The figure is based on calculations with the code JOREK in the publication A. Cathey et al 2020 Nucl. Fusion 60 124007. Credit: A. Cathey, M. Hoelzl/MPG Institute for Plasma Physics.

Central questions concerning H-mode are still unanswered 40 years after its discovery. For example: How exactly can the transition from L-mode to H-mode be explained physically? Or: How thick is the insulation layer, the edge transport barrier? There is still no numerical model that can completely represent the H-mode. So far, theorists have to feed their computer codes with certain initial assumptions to calculate individual phenomena of the H-mode. What they have not yet succeeded in doing is programming a model in which the transition from L-mode to H-mode follows quasi inevitably from physics. With such a model, it would then also be possible to predict the accessibility of the H-mode and the parameters of the ELMs in the not yet completed ITER experiment.

In search of the perfect numerical model

This perfect code would have to combine three physical approaches to plasmas: neoclassical transport, magnetohydrodynamics (see explanations below) and turbulence-focused models. Current codes tend to focus on one of these approaches and, even with this simplification, often keep the world’s best supercomputers busy for months answering limited questions. But the models are getting better and the computers are getting faster.

Two numerical, non-linear models in particular are in use at IPP, both of which are being further developed by international teams with IPP’s participation:

JOREK is based on the magnetohydrodynamic equations.
GENE focuses on micro-turbulences in plasmas.

“Through the interplay of experiments and computer models, we have learned a lot in understanding the H-mode in recent years,” explains Wolfrum. “The theorists compare our experimental results with their numerical models, incorporate necessary physical refinements and thereby in turn obtain results that point us in the direction of new experiments.”

These also always involve adjusting the parameters of plasma density, temperature and magnetic field, which ultimately determine the movement of the particles in the plasma and produce certain modes, i.e. operating modes. Because measurement technology has improved rapidly over the last four decades, plasmas can now be measured more precisely than when the H-mode was discovered, which helps to better describe and understand the plasma state.

What researchers now know: the plasma flows with different velocities at the edge, and it is these flow shears that play a decisive role in the formation of the edge transport barrier. They reduce turbulence at the plasma edge and thus lead to the specific properties of the H-mode.

Strategies for suppressing eruptions at the plasma edge

Science has also recently made great strides in the suppression of large edge localised modes called Type-I ELMs. There are two promising strategies against the large energy eruptions:

1. Weak magnetic pertubation fields can completely eliminate ELMs in the best case. In this method, the otherwise completely axisymmetric magnetic field to confine the plasma is slightly deformed, which, however, reduces the energy confinement time by 10 to 20 percent. Since 2011, the IPP has been researching at ASDEX Upgrade how these pertubation fields must be placed. This method is particularly effective for low plasma densities at the edge. the pertubation fields amount to one part per thousand of the strong toroidal field.
2. The formation of large Type I ELMs can also be prevented by promoting the formation of smaller harmless ELMs. To do this, the otherwise elliptical shape of the plasma cross-section is deformed in the direction of a rounded triangle with the help of magnets. The plasma density at the edge is increased. By selectively blowing more particles into the plasma from the outside, small plasma eruptions then occur at the edge several thousand times per second, which are so benign that they cannot endanger the vessel wall.

“Through H-mode research, we are getting closer and closer to plasma operating states that are most suitable for large fusion facilities like ITER,” Prof. Elisabeth Wolfrum summarised. The now emeritus H-mode discoverer Prof. Friedrich Wagner is excited about the completely new possibilities that the fusion facility in southern France will offer once it is completed: “ITER will be an instrument like we’ve never had on Earth before.” From his work on ASDEX – and especially from the H-mode year 1982 – he has learned one thing: “Progress does not always develop linearly. In between, there are completely unexpected big leaps forward. That’s what makes science so exciting.”

Science papers:
Physical Review Letters 1982
Nuclear Fusion 2020

See the full article here .

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE) And The Vienna University of Technology [TU Wien-Technische Universität Wien] (AT) : “A new solution to one of the major problems of fusion research”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

And

The Vienna University of Technology [TU Wien-Technische Universität Wien] (AT)

10.11.22

Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

Dr. Georg Harrer
Institute of Applied Physics
TU Wien
+43 1 58801 13434
+43 664 4001145
harrer@iap.tuwien.ac.at

Prof. Friedrich Aumayr
Institute of Applied Physics
TU Wien
+43 1 58801 13430
+43 664 605883471
friedrich.aumayr@tuwien.ac.at

Current experiments and simulations show how to avoid destructive plasma instabilities in fusion reactors like ITER.

The renaissance of a disregarded mode of operation

“However, with new experiments and simulations, we have now been able to show: The regime can prevent the dangerous instabilities even in parameter ranges foreseen for reactors.”

Like a pot with a lid

“It’s a bit like a cooking pot with a lid, where the water starts to boil,” Georg Harrer explains. “If pressure keeps building up, the lid will lift and rattle heavily due to the escaping steam. But if you tilt the lid slightly, then steam can continuously escape, and the lid remains stable and doesn’t rattle.” This fusion reactor operation regime can be implemented in a variety of reactors – not only at the ASDEX Upgrade reactor in Garching, but also at ITER currently under construction in France, or even in future DEMO fusion plants.

Science paper:
Physical Review Letters

See the full article here .

five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.

Stem Education Coalition

At The Vienna University of Technology [TU Wien-Technische Universität Wien] (AT) we have been conducting research, teaching and learning under the motto “Technology for people” for over 200 years. TU Wien has evolved into an open academic institution where discussions can happen, opinions can be voiced and arguments will be heard. Although everyone may have different individual philosophies and approaches to life, the staff, management personnel and students at TU Wien all promote open-mindedness and tolerance.

The Vienna University of Technology [TU Wien Technische Universität Wien] is one of the major universities in Vienna, Austria. The university has received extensive international and domestic recognition in teaching as well as in research, and it is a highly esteemed partner of innovation-oriented enterprises. It currently has about 28,100 students (29% women), eight faculties and about 5,000 staff members (3,800 academics).

The university’s teaching and research is focused on engineering, computer science, and natural sciences. The university’s educational offerings have achieved wide international and domestic recognition.

Research

Development work in almost all areas of technology is encouraged by the interaction between basic research and the different fields of engineering sciences at TU Wien. Also, the framework of cooperative projects with other universities, research institutes and business sector partners is established by the research section of TU Wien. TU Wien has sharpened its research profile by defining competence fields and setting up interdisciplinary collaboration centres, and clearer outlines will be developed.

Research focus points of TU Wien are introduced as computational science and engineering, quantum physics and quantum technologies, materials and matter, information and communication technology and energy and environment.

The EU Research Support (EURS) provides services at TU Wien and informs both researchers and administrative staff in preparing and carrying out EU research projects.

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE): “On the Way to the next Stellarator Generation”

From The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik] (DE)

7.8.22

Frank Fleschner
Press officer
+49 89 3299-1317
press@ipp.mpg.de

How can even better stellarators be built in the future? This is the key question that an international group of theoretical physicists pursued at the Simons Workshop at IPP in Greifswald. The two-week format was the culmination of a scientific collaboration that is probably unique worldwide – funded by the Simons Foundation.

Prof. Dr. Amitava Bhattacharjee (left) and Prof. Dr. Per Helander at the Simons Workshop 2022. Photo: IPP.

For a fortnight, not all eyes were focused on the display screen in the Günter Grieger lecture theatre. Researchers walked around the room. Others sat together in groups and discussed with each other, while other participants joined in via video conference. Coffee breaks were scheduled, but many of the scientists just kept working – and decided for themselves when to go outside. The Simons Workshop at the Max Planck Institute for Plasma Physics (IPP) in Greifswald (27 June to 8 July 2022) deliberately left researchers free space so that the unexpected could emerge. “Of course, we also set a framework,” explains host Prof. Dr. Per Helander, head of the stellarator theory department at IPP in Greifswald. So there were usually two to three lectures a day that specified topics. “But otherwise, we fully rely on self-organization of the participants.”

Theorists optimize magnetic fields

Technically, the Simons Workshop was about the next generation of stellarators. These devices pursue one of the two concepts (the other being tokamaks) that physicists hope to use in the future to generate energy through magnetic confinement of fusion plasmas.

The Joint European Torus tokamak generator based at the Culham Center for Fusion Energy located at the Culham Science Centre, near Culham, Oxfordshire, England.

While the sun uses powerful gravitational forces to cause atomic nuclei to fuse, physical tricks are needed on earth to mimic this kind of energy generation. And this is where magnetic cages come into play, such as those used by tokamaks and stellarators. Whereas these extremely strong magnetic fields are shaped axially symmetrically in tokamaks, stellarators follow a completely different concept: using specifically twisted magnetic coils, they generate complex asymmetric fields, which can overcome the technical disadvantages of tokamaks.

The largest and most powerful stellarator facility in the world is Wendelstein 7-X at the IPP in Greifswald – whose design demanded high performance from theoretical physicists and required the use of elaborate computer simulations.

“With stellarators we have many more possibilities than with tokamaks to achieve better results by optimizing the magnetic field,” says Prof. Helander. IPP scientists had demonstrated how effective optimization strategies are for stellarators in a publication in the renowned journal Nature in 2021.

Funding from the Simons Foundation

The participants of the Simons Workshop are working on using their theories to make stellarators possible that will one day far surpass the performance of Wendelstein 7-X. To this end, the international specialists have come together to form what is probably a unique scientific collaboration worldwide: the Simons Collaboration on Hidden Symmetries and Fusion Energy. Since 2018, the international project has been funded by the US Simons Foundation with two million dollars annually.

Stellarators are a unique scientific concept of such complexity that we can only advance it together, says Prof. Dr. Amitava Bhattacharjee, a physicist at Princeton University in New Jersey, and leader of the Simons Collaboration. All of our members agree that they discuss all of their interim findings with each other and hold nothing back. There is a video conference every fortnight – always in the morning between eight and nine o clock US East Coast time. We call it the Simons Hour, explains Prof Bhattacharjee. A core team of 20 researchers is almost always there, he says. Sometimes, however, 80 stellerator specialists join in. Once a year in March, they meet in person in Princeton and in New York.

The highlight of the collaboration, however, is the Simons Workshop, which has had to be cancelled so far due to the Corona pandemic, but which is to take place regularly in the coming years. The event in Greifswald was therefore also a premiere. 74 scientists took part. Because some of them fell ill with Covid-19, not all of them were able to come to the IPP in person, but were only connected via video conference. They only partially experienced the intensive character of the Simons Workshop: Scientists from different institutions around the world meeting in one place for a fortnight – to work together and also spend free time together.

Accelerated scientific progress

During two weeks of Simons Workshop, many of the most important aspects of stellarator optimization were addressed – such as minimizing turbulence in the plasma, fast ions that carry much of the energy generated during fusion, and diverters that cleanse the plasma of reaction products in fusion facilities. “A particularly promising result of the collaboration is the new computer code SIMSOPT, which achieves better results than previous methods,” says Prof. Helander. This makes it possible, for example, to design stellarators that can confine alpha particles (i.e. the helium-4 nuclei produced during fusion) better than the large-scale international fusion experiment ITER – a facility based on the tokamak principle which is currently under construction.

Alpha particles are supposed to heat the plasma in fusion power plants, thereby helping to sustain the fusion reaction. SIMSOPT can also design stellarator concepts in which micro-turbulence of the ITG (Ion Temperature Gradient) type is significantly reduced compared to Wendelstein 7-X.

For Prof. Bhattacharjee, the successes of the Simons Collaboration are no coincidence. He is certain: The intensive collaboration dramatically accelerates scientific progress.

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The MPG Institute for Plasma Physics [MPG Institut für Plasmaphysik](DE) is a physics institute for the investigation of plasma physics, with the aim of working towards fusion power. The institute also works on surface physics, also with focus on problems of fusion power.

The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

It owns several large devices, namely

the experimental tokamak ASDEX Upgrade (in operation since 1991)

It also cooperates with the ITER and JET projects.

The MPG Institutes focus on excellence in research. The MPG Society has a world-leading reputation as a science and technology research organization, with 33 Nobel Prizes awarded to their scientists, and is generally regarded as the foremost basic research organization in Europe and the world. In 2013, the Nature Publishing Index placed the MPG institutes fifth worldwide in terms of research published in Nature journals (after Harvard University, The Massachusetts Institute of Technology, Stanford University and The National Institutes of Health). In terms of total research volume (unweighted by citations or impact), the Max Planck Society is only outranked by The Chinese Academy of Sciences [中国科学院](CN), The Russian Academy of Sciences [Росси́йская акаде́мия нау́к](RU) and Harvard University. The Thomson Reuters-Science Watch website placed the MPG Society as the second leading research organization worldwide following Harvard University, in terms of the impact of the produced research over science fields.

The MPG Society and its predecessor Kaiser Wilhelm Society hosted several renowned scientists in their fields, including Otto Hahn, Werner Heisenberg, and Albert Einstein.

History

The organization was established in 1911 as the Kaiser Wilhelm Society, or Kaiser-Wilhelm-Gesellschaft (KWG), a non-governmental research organization named for the then German emperor. The KWG was one of the world’s leading research organizations; its board of directors included scientists like Walther Bothe, Peter Debye, Albert Einstein, and Fritz Haber. In 1946, Otto Hahn assumed the position of President of KWG, and in 1948, the society was renamed the Max Planck Society (MPG) after its former President (1930–37) Max Planck, who died in 1947.

The MPG Society has a world-leading reputation as a science and technology research organization. In 2006, the Times Higher Education Supplement rankings of non-university research institutions (based on international peer review by academics) placed the MPG Society as No.1 in the world for science research, and No.3 in technology research (behind AT&T Corporation and The DOE’s Argonne National Laboratory.

The domain mpg.de attracted at least 1.7 million visitors annually by 2008 according to a Compete.com study.

MPG Institutes and research groups

In addition, there are several associated institutes:

International Max Planck Research Schools

Max Planck Schools

• Max Planck School of Cognition
• Max Planck School Matter to Life
• Max Planck School of Photonics

Max Planck Center

• The Max Planck Centre for Attosecond Science (MPC-AS), POSTECH Pohang
• The Max Planck POSTECH Center for Complex Phase Materials, POSTECH Pohang

Max Planck Institutes