RSS- EUROfusion https://www.euro-fusion.org/ en-gb TYPO3 News Sun, 19 Sep 2021 22:31:37 +0200 Sun, 19 Sep 2021 22:31:37 +0200 31 TYPO3 EXT:news news-936 Tue, 27 Jul 2021 11:34:37 +0200 Croatian support for the DONES project https://www.euro-fusion.org/news/detail/croatian-support-for-the-dones-project/ DONES is the first ESFRI project in which Croatia plays a key role and the second most important device in a large international fusion energy project, right after ITER. In 2018, DONES was included among the ESFRI projects, strategically important for the EU, as a Spanish-Croatian initiative. Read the original article in Croatian

Google Translate this article

 

This story was originally published by our Croatian Consortium Member Ruđer Bošković Institute (RBI).

]]>
Highlights RSS-feed Member News
news-935 Tue, 27 Jul 2021 09:31:55 +0200 Start-up of the new OLMAT facility https://www.euro-fusion.org/news/detail/start-up-of-the-new-olmat-facility/ study of materials under extreme thermal loads On July 2 the installation of the OLMAT facility (Optimization of Advanced Liquid Metal Targets) at the National Fusion Laboratory was completed. The facility is the only one of its kind in Spain and one of the few existing in Europe. It can be used to test materials, both solid and liquid, under extreme heat flow conditions, on the order of those that exist on the surface of the Sun itself.

Read the original article in Spanish

Google Translate this article

 

This story was originally published by our Spanish Consortium Member CIEMAT.

 

]]>
Highlights RSS-feed Member News
news-934 Tue, 27 Jul 2021 09:05:02 +0200 JT-60SA https://www.euro-fusion.org/news/detail/jt-60sa/ The latest on integrated commissioning The JT-60SA tokamak—a joint program of fusion research and development agreed and co-financed by the European Atomic Energy Community (Euratom) and the government of Japan—entered its integrated commissioning phase in late 2020, after a six-year project to modify and modernize the existing JT-60U tokamak at the Naka Fusion Institute in Japan.

During the step-by-step integrated commissioning process, the air was first evacuated from the vacuum vessel and surrounding cryostat before the device's superconducting magnets were slowly cooled to the temperature of 4 K (- 269 °C). Next, the vacuum vessel was "baked" to 200 °C to rid it of moisture and any possible residual contaminants. Finally the magnets were energized—first independently and then as a full group.

In March 2021, during the coil energization test of poloidal field coil EF1, feeder joints were damaged. Experts from both Japan and Europe investigated the cause of the damage and determined that the joints of the EF1 feeders needed to be reinforced with greater insulation.

Repairs will be carried out on the incriminated joints and others to prevent recurrence of the incident. Once the repairs and improvements are completed, EF1 will undergo further testing to determine that it can withstand even worst-case conditions and ensure that it is ready for operation.

JT-60SA integrated commissioning is expected to resume in February 2022.

Find out more on the JT-60SA website.

 

This story was originally published by our partner ITER.

]]>
Highlights RSS-feed Partner News
news-933 Tue, 27 Jul 2021 08:19:52 +0200 New diagnostic will improve understanding of plasma in Super-X divertor region https://www.euro-fusion.org/news/detail/new-diagnostic-will-improve-understanding-of-plasma-in-super-x-divertor-region/ A new, multi-wavelength imaging (MWI) camera diagnostic fitted on MAST Upgrade, will offer scientists a picture of the impact that the machine’s Super X divertor design has on the hot, charged plasma. A new, multi-wavelength imaging (MWI) camera diagnostic fitted on MAST Upgrade, will offer scientists a picture of the impact that the machine’s Super X divertor design has on the hot, charged plasma.

The Super X divertor or ‘exhaust’ system on MAST Upgrade has already shown at least a tenfold reduction in the heat leaving the main plasma chamber. And now, thanks to a new filtered imaging system – which provides 11 views of the divertor simultaneously – scientists will be able to get more insight into how this divertor works than ever before.

Light emitted by the plasma in the divertor region is routinely measured by scientists in order to work out the plasma conditions and plasma performance. The MWI has 11 cameras, each of which is filtered so as to target a different wavelength band of this emitted light — i.e. a different color. Due to a physics process called ‘spectral line emission’, these different wavelength bands correspond to light emitted by different elements that are present in the plasma. This means that some of the MWI cameras can be used to capture videos of the main hydrogen fuel, while others can be used to capture videos of impurity elements like carbon and helium at the same time. Since the original MAST experiment only had a single filtered camera viewing its divertor, the MWI captures a lot more useful data each time the experiment runs.

The MWI system has been developed over the last three years through a collaboration between Durham University, the University of York and scientists at Culham. It builds on similar work by scientists at the Dutch Institute For Fundamental Energy Research (DIFFER) and the TCV tokamak in Switzerland. DIFFER collaborators are now playing an important role in helping scientists at Culham interpret the MWI data taken on MAST Upgrade.

Joe Allcock, Spherical Tokamak Imaging Researcher at UKAEA, said: “The MWI camera system is essentially 11 cameras in a row inside a large black box with a tube at one end. This tube looks down through a port window and into the divertor region below the main plasma chamber.

Shown in red in the diagram is the path taken by light through the system (Xiande Feng, Durham University)

Joe added that one of the key performance indicators of a divertor was the amount of power deposited by the plasma onto the walls.

“We developed this Super X design because our physics simulations predict we should see a drop in the power that’s reaching the divertor target.  By comparing these simulations to data from the MWI and other diagnostics, we can gauge how accurate our physics understanding is, and how reliable our predictions will be when we design a future fusion reactor.

“Whereas other diagnostic techniques – like the Thomson scattering laser system – offer an excellent picture at a few single points in the plasma, the MWI has a wide view, helping us build up a comprehensive idea of what is happening, and where, across the divertor. This is essential for improving our understanding of the physics behind the Super X.”

 

The photograph shows what the MWI looks like installed on MAST Upgrade. copyright UKAEA

 

 

This story was originally published by our UK Consortium Member UKAEA.

]]>
Highlights RSS-feed Member News
news-932 Mon, 26 Jul 2021 09:31:53 +0200 Dutch Magnum-PSI sees reduced plasma impact on reactor wall https://www.euro-fusion.org/news/detail/dutch-magnum-psi-sees-reduced-plasma-impact-on-reactor-wall/ Recent experiments have shown that the velocity of the plasma flux near the wall in Magnum-PSI is going down with increasing plasma density. “Magnum-PSI can create very high density plasmas and we are interested in the impact of the plasmas on the wall and the plasma-facing components,” says Jonathan van den Berg-Stolp. He is the first author of a publication which was recently accepted by Nuclear Fusion. Jonathan van den Berg is a PhD student in the Plasma Edge Physics and Diagnostics group at DIFFER. Recent experiments have shown that the velocity of the plasma flux near the wall in Magnum-PSI is going down with increasing plasma density.

When a plasma touches the wall, the electrically charged particles (ions) in the plasma are neutralized. This neutralized gas interacts with the ions. Especially in the dense conditions of Magnum-PSI, this interaction reduces the speed and energy of the #plasma near the wall. In this way, the plasma load on the wall is reduced. This happens in a region only a few millimeters away from the wall.

These results are relevant to fusion reactors like ITER, which is being built in southern France. At the bottom of the ITER vacuum vessel, which will contain the plasma of the reactor, a divertor will extract heat and ash produced by the fusion reaction. The divertor is made of tungsten, the metal with the highest melting point, and it protects the surrounding walls from high temperatures and high-speed neutrons.

“There is an overlap between Magnum-PSI and ITER divertor conditions,” says Van den Berg , “and the near-surface interaction region in ITER is expected to be even smaller than in Magnum-PSI. But it is also good to keep in mind that Magnum-PSI and ITER do not have the same geometry and angle of plasma incidence, which will affect the interaction with the neutral gas.” Therefore it is important to include these effects in the modeling of plasma-wall interaction in future fusion machines.”

Publication
Jonathan van den Berg-Stolp, Hennie Johannes van der Meiden, Ivo G J Classen, Jordy Vernimmen, Yu Li, John Scholten, Serge Brons and Gerard J Van Rooij
Thermalized collisional pre-sheath detected in dense plasma with coherent and incoherent Thomson scattering
Nuclear Fusion, Accepted Manuscript online 2 July 2021

 

This story was originally published by our Dutch Consortium Member DIFFER

]]>
Highlights RSS-feed Member News
news-931 Wed, 14 Jul 2021 08:57:00 +0200 First Governing Council for promoting IFMIF-DONES in Granada https://www.euro-fusion.org/news/detail/first-governing-council-for-promoting-ifmif-dones-in-granada/ The Consortium for the promotion of IFMIF-DONES in Granada begins with the first meeting of its Governing Council. Read the original article in Spanish

Google Translate this article

This story was originally published by our Spanish Consortium Member CIEMAT.

]]>
Highlights RSS-feed Member News
news-930 Thu, 08 Jul 2021 07:57:20 +0200 A cooled exhaust for Wendelstein 7-X https://www.euro-fusion.org/news/detail/a-cooled-exhaust-for-wendelstein-7-x/ Thanks to a newly-installed actively-cooled exhaust, the German stellarator Wendelstein 7-X at IPP Greifswald will be able to maintain its fusion plasma for up to 30 minutes - a fusion milestone. Some find the spiraling design of a stellarator the height of beauty, others can't stand its asymmetric looks. A stellarator's magnets - necessary to keep the hot, charged fusion fuel (plasma) away from the inner walls - are individually shaped and positioned for an ideal magnetic confinement.

Aesthetics (and the engineering hurdles to constructing a stellarator in the first place) are not high on the list of concerns for the experts at the IPP in Greifswald. Their Wendelstein 7-X stellarator is the world's most advanced in its class, and may offer a road to fusion energy that outperforms the trusted tokamak design with longer, more stable discharges.

Performance boost

After first experimental campaigns starting in 2015, Wendelstein 7-X (W7-X for friends) is now undergoing a major upgrade campaign. The most recent milestone to celebrate is an important step in the process: completing the new, actively-cooled divertor (exhaust) of the stellarator. The new water-cooled divertor components (designed at KiP and ITZ Garching) will usher the fantastic fusion heat out of the device, allowing it to run for up to 30 minutes per experiment.

The shape and positioning of Wendelstein 7-X's magnets were calculated by supercomputer to optimally confine the hot plasma in the stellarator. Credit: IPP

Limits of technology

On Friday 18 June 2021, the last of a total of 60 divertor modules was installed in the Wendelstein 7-X plasma vessel. With this, an extremely important technical milestone was reached and after 20 months of assembly time, all actively-cooled divertor target modules have now been successfully integrated. All water connections have been leak-tested locally, some critical flanges at 29 times the atmospheric pressure.

With one narrow exception, all the modules met their tolerance requirements, far below the millimeter scale. This is a major success at the limits of what is technically feasible, and was only possible thanks to an outstanding assembly team – work preparation, technologists, shift supervisors, welders, fitters, vacuum and quality assurance.

A critical collaboration during the upgrade campaign has been the work between the assembly and scientific departments. Together, they evaluated (mostly minor) deviations in the assembly phase and worked out how to manage them.

The current engineering shutdown will continue throughout the year so that a new and improved W7-X can restart its fusion experiments in 2022. According to the current plan, the assembly of the remaining vessel installations, including rework, can be completed by 9 December 2021.

Roadmap to Fusion Energy

Stellarator research is one of the eight missions in the EUROfusion Roadmap to Fusion Energy. This roadmap represents the most comprehensive fusion R&D programme in the word and lays out everything to advance fusion from the lab to the demonstrator stage.

The main focus of EUROfusion is on the most mature fusion device design: the ring-shaped tokamak. Stellarators, although more challenging from an engineering perspective, could offer an alternative pathway to fusion energy through their intrinsically stable and long-lasting plasma discharges.

This story was originally published by our German Consortium Member Max Planck Institute for Plasma Physics (IPP) in Greifswald on their internal W7-X blog.

author: Dr Thomas Klinger, editor: Gieljan de Vries

]]>
RSS-feed Member News
news-929 Tue, 06 Jul 2021 08:57:22 +0200 Spanish bid to host IFMIF-DONES in Granada https://www.euro-fusion.org/news/detail/spanish-bid-to-host-ifmif-dones-in-granada/ On June 9th, a consortium agreement was signed to promote the Spanish bid to host the international fusion materials research facility IFMIF-DONES in Granada, Spain. Read the original article in Spanish

Google Translate this article

This story was originally published by our Spanish Consortium Member CIEMAT.

]]>
Highlights RSS-feed Member News
news-928 Thu, 01 Jul 2021 10:22:29 +0200 Science from the decommissioned experiment RFX-mod https://www.euro-fusion.org/news/detail/science-from-the-decommissioned-experiment-rfx-mod/ Is it possible to obtain scientific data from a machine that has been disassembled since 2016? The team of the RFX Consortium believes so. Read the original article in Italian

Google Translate this article

This story was originally published by our Italian Consortium Member Consorzio RFX

]]>
Highlights RSS-feed Member News
news-927 Thu, 01 Jul 2021 09:59:41 +0200 ITER Robots : la 10ème finale a eu lieu! https://www.euro-fusion.org/news/detail/iter-robots-la-10eme-finale-a-eu-lieu/ The final of the ITER Robots competition took place on June 15, in the gymnasium of the College of Puy Sainte Reparade. Check out this video summary! Read the original article in French

Google Translate this article

This story was originally published by our French Consortium Member CEA-IRFM.

]]>
Highlights RSS-feed Member News
news-926 Thu, 01 Jul 2021 08:43:05 +0200 Europe ready to prove the fabrication of Test Blanket Modules https://www.euro-fusion.org/news/2021/june/europe-ready-to-prove-the-fabrication-of-test-blanket-modules/ ITER will provide a unique opportunity to test mock-ups of different breeding blanket concepts. Highlights RSS-feed Partner News news-925 Wed, 30 Jun 2021 12:09:29 +0200 Interview Marco de Baar: a bumpy way up https://www.euro-fusion.org/news/2021/june/interview-marco-de-baar-a-bumpy-way-up/ Marco de Baar always knew that he would eventually hold a senior position in research. But he never thought this would be possible at DIFFER, the institute that he has called his home since 2007. Nevertheless, he is now DIFFER’s scientific director, albeit in a challenging year. Highlights RSS-feed Member News news-924 Wed, 30 Jun 2021 12:00:40 +0200 Strong Culham participation at leading European fusion conference https://www.euro-fusion.org/news/detail/strong-culham-participation-at-leading-european-fusion-conference/ Culham scientists will share their expert research at the 47th European Physical Society’s (EPS) Plasma Physics conference this week (June 21 – June 25). Of particular note at the event – Europe’s premier fusion science conference, hosted online for the first time ever – will be a plenary talk from UKAEA Chief Scientist William Morris. Entitled “Towards a Fusion Reactor: Integration of Physics and Technology”, William’s talk aims to provide an overview of the scientific and technical challenges facing the development of fusion energy and the importance of an integrated approach to developing designs for power plants, such as the EU DEMO and UK STEP programmes.

Further UKAEA contributions include Kevin Verhaegh’s talk accompanying his EPS PhD research award. This focuses on developing techniques to understand divertor detachment (techniques used to minimise contact between the fusion device’s plasma fuel and its ‘divertor’ exhaust system) using spectroscopic techniques on the Swiss tokamak, TCV. This has led to new insights into understanding what drives the dissipation of particles in tokamak divertors – something essential for future fusion devices, including ITER and beyond. These techniques will be applied to UKAEA’s MAST Upgrade experiment to better understand the potential benefits of advanced divertor configurations.

Other work presented by UKAEA at the event ranges from disruption mitigation in JET and stability in the core and edge of tokamak plasmas, to instabilities caused by fusion reactions, exhaust physics and the importance of confronting scientific and engineering challenges to develop integrated power plant designs.

UKAEA’s Science Programme Leader for MAST Upgrade, James Harrison, said: “It’s great to see such strong participation in Europe’s most prestigious plasma physics conference, with over 12 UKAEA researchers attending.

“The breadth of contributions, on key topics for ITER and other future fusion devices, shows how we’re making a strong contribution to the success of fusion energy.”

For more information please visit the EPS website.

This story was originally published by our UK Consortium Member UKAEA.

]]>
Highlights RSS-feed Member News
news-922 Mon, 28 Jun 2021 07:45:10 +0200 Wendelstein 7-X upgrading for next experimental campaign https://www.euro-fusion.org/news/2021/june/wendelstein-7-x-upgrading-for-next-experimental-campaign-copy-1/ An upgrade to the optimized stellarator fusion experiment Wendelstein 7-X at IPP in Greifswald, Germany will make it possible to stretch plasma discharges at high heating power to half an hour in duration. Highlights RSS-feed Member News news-921 Wed, 23 Jun 2021 12:37:12 +0200 Digital twins for fusion plasmas https://www.euro-fusion.org/news/detail/digital-twins-for-fusion-plasmas/ Major advances in plasma modelling and simulation allow for predicting what a fusion plasma will do instead of needing to interpret after the fact. A recent publication from Max Planck Institute for Plasma Physics (IPP) on the theoretical prediction of a novel transport barrier in a fusion plasma and its subsequent experimental confirmation (Physical Review Letters) exemplifies how dramatically the power of plasma simulations and modelling has grown in recent years. A Europe-wide project on plasma theory and simulation is to enhance this development. The aim is to create virtual plasma models as digital twins of real plasmas.

A new type of transport barrier in fusion plasmas that improves the magnetic confinement of the plasma was predicted by a team of theorists at IPP with the help of state-of-the-art simulations. Caused by fast plasma particles, the barrier should be able to strongly suppress turbulences in the plasma locally. An experiment planned according to corresponding specifications in the Garching ASDEX Upgrade fusion device was subsequently able to confirm this theoretical prediction: fast particles generated by precisely applied heating of the plasma with radio waves created an area in the centre of the plasma with the expected improved confinement properties. The work has now been accepted for publication by the the scientific journal Physical Review Letters (A. Di Siena et al., preprint: http://arxiv.org/abs/2010.14839).

“This great success of theory,” says Professor Frank Jenko, head of Tokamak Theory division at IPP in Garching, “is just one of many examples that show how dramatically plasma simulations and modelling have improved in recent years.” The available computer power has also greatly increased, so that sophisticated computational models have become able to describe the complex physics of plasma very well. This makes quantitative predictions possible - a “giant leap forward” compared to the past twenty years: “Instead of merely interpreting measurement data, as was previously the case,” says Frank Jenko, “theory and simulation now provide models with reliable predictive power in many subject areas”. In addition, in the supercomputer theory can now bring together phenomena that were previously studied separately – such as the physics of fast particles and turbulence – and thus elucidate increasingly complex relationships.

In the European fusion programme, coordinated by the EUROfusion consortium, the aim is to use the new possibilities to optimally prepare the operation of the international ITER experiment and the design of the DEMO demonstration power plant planned to follow. With strategically selected projects, the E-TASC initiative (EUROfusion - Theory and Advanced Simulation Coordination) is providing a new structure for this part of the research. A Europe-wide coordinated work programme on open key questions in theory, simulation, verification and validation – supported by new standard software to be developed – is to advance the development of predictive power in plasma physics, materials science and engineering.

Of the fourteen research projects selected in this framework for the work plan for 2021 to 2025, which EUROfusion awarded to scientists throughout Europe, five went to IPP in Garching and Greifswald. Also, one of the five expert teams for high-performance computing and code optimisation will be based here. “The ambitious goal we are pursuing with E-TASC is to create virtual plasma models as digital twins of real plasmas,” explains Frank Jenko, one of the two chairs of the E-TASC Scientific Advisory Board. This “plasma in the computer” is to be gradually joined by models of other DEMO subsystems in order to gradually build up a digital design and simulation capability for the power plant that is as comprehensive as possible.

This article was originally published by our member IPP.

]]>
Highlights RSS-feed Member News
news-920 Wed, 23 Jun 2021 10:32:16 +0200 Strong Portuguese participation at ECPD2021 https://www.euro-fusion.org/news/detail/strong-portuguese-participation-at-ecpd2021/ Two researchers from the Portuguese EUROfusion member IPFN contributed with oral presentations to the 4th edition of European Conference on Plasmas diagnostics, showcasing their state-of-the-art projects. Two IPFN researchers contributed with 2 oral presentations at the 4th edition of European Conferenceon Plasmas diagnostics that took place online between 7 and 11 June 2021,  recognizing the state-of art activity they are developing in the field.

The  European Conference on Plasma Diagnostics is a biennial event that aims at bringing together physicists or other scientists working on diagnostics for magnetic confinement fusion, beam plasmas and inertial fusion, low-temperature and industrial plasmas, and basic and astrophysical plasmas. The chairman of the International Scientific Committee of this edition is also an IPFN researcher, Bruno Soares Gonçalves.

This year ECPD2021 had the participation of more than 160  scientists and engineers from different countries over the course of 5 days. IPFN researchers were authors of 6 contributions and co-authors of other several presented works, in collaboration with international teams. Among those, we highlight the oral contribution from Daniel Hachmeister , an APPLAUsE Phd student, and from  Filipe Silva an IPFN researcher

Daniel Hachmeister presented his work developed in the frame of his PhD work, entitled “The impact of inverted density gradients on density profiles measured by reflectometry”

Filipe Silva presented his work on the progresses on “Benchmarking 2D against 3D FDTD codes for the assessment of the measurement performance of a low field side plasma position reflectometry”

The next conference will be ECPD2023, in Salamanca.

This article was originally published by our member IPFN.

]]>
Highlights RSS-feed Member News
news-919 Wed, 23 Jun 2021 10:08:55 +0200 ITER Feedthrough prototypes pass testing successfully https://www.euro-fusion.org/news/detail/iter-feedthrough-prototypes-pass-testing-successfully/ F4E Diagnostics and their supplier IDOM have performed extensive tests on the connectors that will carry ITER data from inside the experiment to experts outside. ITER requires an extensive diagnostic system to monitor the experiment. Inside the Vacuum Vessel, there will be many sensors to measure the temperature, irradiation, composition, etc. of the plasma. The signals produced by the sensors will travel through the walls of the vacuum vessel so that experts outside can interpret the data.

Cables carrying those signals must be very resistant to withstand the extreme conditions of ITER. Moreover, as the vacuum vessel is hermetically sealed, cables must run through it without breaking the vacuum. The F4E Diagnostics Team, together with the F4E supplier IDOM, have been working on different feedthrough prototypes to accomplish these objectives. Last year, we saw some promising results at the beginning of the testing campaign.

As a continuation of this activity, from December 2020 until last March, the prototypes have gone through a series of tests designed to push them to their limits. It is as if the prototypes had undergone a series of dramatic episodes in a very short span of time: an unexpected release of vapour (pressure test), an earthquake (accidental vibration test), a collision with another object (impact test), a fire (overtemperature test), etc. After all these events, one could expect that the prototypes would be severely damaged. But it was not the case. The final leak test showed that the prototypes still kept a level of tightness almost as good as at the beginning of the whole process.

Tecnalia, an IDOM subcontractor, has been in charge of performing this test battery. “This test campaign has been really a challenge due to the wide variety of tests involved and of course due to the pandemic period that inevitably slowed down its execution. The challenge was finally overcome thanks to the professionalism of Tecnalia, CTA (for vibration tests) and IDOM technicians,” explains Isabel Aramburu, Tecnalia Materials Engineering Lab Manager.

Iñigo Eletxigerra, IDOM Project Team Leader, also stresses the work prior to these tests. “The successful completion of the qualification tests for the In-Vessel electrical feedthroughs is the culmination of several years of design and prototyping works carried out by an excellent team.”

Miguel Pérez, F4E Project Manager, welcomes the results. “We are very satisfied, and to some extent very positively surprised, with the results of this qualification campaign on the In-Vessel electrical feedthroughs. Currently, we are in the process of concluding the final design review. We expect to produce the drawings that will be given to the manufacturers within the year and to start fabricating the item in 2022.”

This article was originally published by our partner F4E.

]]>
Highlights RSS-feed Partner News
news-918 Mon, 14 Jun 2021 11:32:39 +0200 Eleven EUROfusion Researcher Grants awarded https://www.euro-fusion.org/news/2021/june/eleven-eurofusion-researcher-grants-awarded/ The EUROfusion consortium for the realisation of fusion energy has awarded eleven EUROfusion Researcher Grants (ERG) to talented post-doctoral researchers across Europe. Highlights RSS-feed EUROfusion news-917 Mon, 14 Jun 2021 10:07:05 +0200 Bursting the bubble of artificial solar flares https://www.euro-fusion.org/news/detail/bursting-the-bubble-of-artificial-solar-flares/ Triggering artificial solar flares early may help protect the inner wall of fusion research devices, show EUROfusion researchers. Build an artificial sun and you will get artificial solar flares. Our own star is a roiling mass of plasma (hot, ionised gas) that sometimes shoots powerful eruptions into space. Like the Sun, the hot plasma in a fusion device doesn't sit there quietly - it bucks against its magnetic restraints, building up pressure until all of a sudden a stream of energy hotter than the surface of the sun bursts forth headed towards the inner wall of the vacuum chamber.

Needless to say, fusion researchers are eager to learn how to dampen these flares they call Edge Localised Modes, ELMs for short, before they cause any damage. Understanding and controlling such plasma instabilities to ensure smooth, high-performance plasmas is one of the eight missions in the EUROfusion Roadmap to Realising Fusion Energy."

Lightning strike

Left unchecked, ELMs can eventually blast the inner wall of a fusion device with a heat pulse of up to a thousand megawatts per square meter. If you're hazy on the units, that's more intense than a blowtorch, hotter even than the surface of the sun, and in fact is most comparable to a lightning strike. Too many of those ELMs, and the power plant would need to shut down for costly repairs, causing delays to important fusion research.

ELMs could be good, however. Counter-intuitively, causing the plasma to produce ELMs more often than it would on its own may actually reduce the heat load on the plasma exhaust components of a tokamak fusion device. This important finding is the result of detailed computer simulations by a European research team lead by Andres Cathey at the German Max Planck Institute for Plasma Physics (IPP).

In the scientific journal Plasma Physics and Controlled Fusion, Cathey and his colleagues show how shooting the plasma edge with a tiny pellet of frozen deuterium triggers a smaller, more manageable ELM ahead of time. Their new virtual simulations match actual experiments performed at EUROfusion research tokamak devices like JET and ASDEX Upgrade, as well as at the U.S. tokamak DIII-D.

Balancing energy and area

As in all complex systems, just popping ELMs early isn't the end of this story. A trade-off will be necessary, because the simulations show that a triggered ELM focuses its energy on a smaller wall area than an unmitigated one. Achieving the right balance between the reduced ELM size and deposition area will therefore crucial to properly use this ELM control method. Still, bursting the bubble might just turn out to be a great idea for future fusion power plants.

Scientific publication:

Comparing spontaneous and pellet-triggered ELMs via non-linear extended MHD simulations

 

]]>
Highlights RSS-feed EUROfusion
news-916 Thu, 10 Jun 2021 08:49:01 +0200 ORNL reprises key supporting role in historic fusion experiments As part of a long-running collaboration with Europe, ORNL is supporting landmark experiments aiming for a fusion milestone. Highlights RSS-feed Partner News news-914 Wed, 26 May 2021 14:16:20 +0200 Symposium: fusion from a social science perspective https://www.euro-fusion.org/news/2021/may/symposium-fusion-from-a-social-science-perspective/ A symposium on 18 June explores the historical, organisational, diplomatic and economical sides of fusion. Highlights RSS-feed news-913 Mon, 24 May 2021 11:00:00 +0200 Danish universities join fusion forces https://www.euro-fusion.org/news/detail/danish-universities-join-fusion-forces/ The new DANfusion consortium brings together groups from four Danish universities to strengthen the nation's fusion research. Følgeforskningscenter

With a 40,000 Euro grant from the Danish government, researchers from four Danish universities have set up the new fusion consortium DANfusion. This new initiative will serve as a forum where these physics and engineering researchers can come together to work on research and development for fusion.

DANfusion is the newest of Denmark's følgeforskningscentre (research follow-up centres) funded by Denmark's Ministry of Higher Education and Science. These centres exist to strengthen and grow the national academic communities connected to European Big Science facilities. With DANfusion, there are now four centres linked to ITER, F4E and EUROfusion, CERN, ESA, ESO, ESS, ILL, XFEL and soon the EMBL.

Enhancing collaboration

In addition to the Technical University of Denmark (DTU), the Danish EUROfusion member, DANfusion includes research groups from Aarhus University, Aalborg University and the University of Southern Denmark in Odense. DANfusion will use their government grant to allow researchers to travel to national and international fusion experiments to get to know the field. The grant will also facilitate national meetings to foster collaboration, and will allow PhD students to join fusion-relevant summer schools.

"Our goal is to strengthen the connections and collaboration between all the fusion-relevant research groups at Danish universities", says DANfusion leader and fusion veteran Søren Bang Korsholm at DTU. "Working together on a Big Science theme like fusion offers great advantages to Danish researchers - and to the field we're joining!" As an example, he mentions the experience in remote handling and power electronics that the new research groups bring in. "The fact that three of our members already won EUROfusion research grants on their first application shows that we can offer valuable contributions to EUROfusion by involving a broader field of researchers ".

Later this year, the DANfusion partners will meet for an extended kick-off meeting to discuss joint activities in research and knowledge transfer. At EUROfusion, we look forward to hearing more from them!

EUROfusion represents the collaborative spirit of the European fusion research landscape. Our thirty consortium members in the EU, Switzerland, United Kingdom and Ukraine connect over 150 universities, research institutes and companies to the European effort to realise fusion energy, with access to research programmes, funding and top research facilities.

 

]]>
Highlights RSS-feed EUROfusion
news-912 Tue, 11 May 2021 09:02:00 +0200 Hungary’s secret to growing top fusion talent https://www.euro-fusion.org/news/2021/may/hungarys-secret-to-growing-top-fusion-talent/ Young fusion researchers shine in student competition. Highlights RSS-feed EUROfusion news-911 Wed, 05 May 2021 09:13:33 +0200 KIT Prints Tungsten Components by Electron Beam Melting https://www.euro-fusion.org/news/detail/kit-prints-tungsten-components-by-electron-beam-melting/ Researchers of KIT have developed an innovative approach to making brittle Tungsten soft. Tungsten has the highest melting point of all metals, 3,422 degrees Celsius. This makes the material ideal for use at high temperatures in e.g. space rocket nozzles, heating elements of high-temperature furnaces, or the fusion reactor. However, the metal is highly brittle and, hence, difficult to process. Researchers of Karlsruhe Institute of Technology (KIT) have developed an innovative approach to making this brittle material soft. To process tungsten, they have determined new process parameters for electron beam melting.

Tungsten is a metal with very attractive properties: It is corrosion-resistant and as heavy as gold. In the form of tungsten carbide, it is as hard as diamond. And it has the highest melting point of all metals, 3,422 degrees Celsius. However, the metal is highly brittle at room temperature. Due to its properties, tungsten is difficult to process using conventional methods. Processing is expensive and time-consuming. An alternative is 3D printing that allows to produce tungsten components that require hardly any finishing. “At the moment, we are working on the additive manufacture of tungsten components by electron beam melting, EBM for short,” says Dr. Steffen Antusch from the Institute for Applied Materials – Materials Science and Engineering (IAM-WK) of KIT. The team succeeded in adapting the EBM process to tungsten. Having developed specific process parameters, 3D printing of tungsten components is now possible. “This metal can be applied in many areas. Thanks to its special properties, it is ideally suited for high-temperature applications in energy and light technologies, aerospace industry, and medical engineering. It is indispensable in modern high-tech industry,” says Alexander Klein, IAM-WK.

Pre-heating Enables Processing of Brittle Materials

EBM is an additive manufacturing method. Electrons accelerated under vacuum selectively melt metal powder and, in this way, produce a 3D component in an additive way, that is layer by layer. The big advantage of this method consists in the energy source used, the electron beam. It is used to pre-heat the metal powder and the carrier plate prior to melting, as a result of which deformation and inherent stress are reduced. It is possible to process materials that easily break at room temperature and can be deformed at high temperature.

However, the materials used must be electrically conductive. Hence, the process is not suited for ceramic materials, as EBM is based on the principle of electric charging.

Lightweight Titanium Components for KA-RaceIng

Originally, EBM was developed to process titanium alloys and materials needing higher process temperatures. So far, EBM has been used to produce lightweight titanium components for KIT’s KA-RaceIng formula student project.

Under research programs of the Helmholtz Association and EUROfusion, the European Fusion Programme, IAM-WK studies materials and processes for future high-temperature applications in the area of fusion energy or medical engineering.

More about the KIT Materials Center: https://www.kit.edu/topics/materials.php

This article originally appeared on the website of EUROfusion consortium member KIT.

]]>
Highlights RSS-feed Member News
news-906 Fri, 30 Apr 2021 10:00:00 +0200 EU-US Breakthrough Mitigates Effects of Fusion Instabilities https://www.euro-fusion.org/news/2021/april/eu-us-breakthrough-mitigates-effects-of-fusion-instabilities/ A new braking technique can protect future fusion devices from damage caused when fast electrons erupt from their 150-million-degree fusion plasma. Highlights RSS-feed Press releases news-908 Fri, 30 Apr 2021 09:10:00 +0200 High Performance Computing and GENE-3D https://www.euro-fusion.org/news/detail/high-performance-computing-and-gene-3d/ HPC plays an important role in the field of nuclear fusion. Supercomputers all over the world are used to simulate plasma-wall interactions, plasma turbulence, neutron loading, and optimization problems such as the one undertaken to design the stellarator W7-X. High Performance Computing (HPC) has been driving advances in science, technology, medicine, and many other fields since its beginnings in the 1960s. After some years of developing the technology, the Cray-1 supercomputer debuted in 1975 with a processing capability of 160 megaFLOPS. (FLOPS stands for Floating Point Operations Per Second, which is a measure of how many calculations a computer can perform. A computer at 10 FLOPS can perform roughly 10 calculations per second. A megaFLOPS is one million, or 106, FLOPS.) It’s expected that systems coming online in 2021 will break the "exascale" barrier, achieving exaFLOPS performance (exaFLOPS means one billion billion, or 1018, FLOPS).

HPC plays an important role in the field of nuclear fusion. Supercomputers all over the world are used to simulate plasma-wall interactions, plasma turbulence, neutron loading, and optimization problems such as the one undertaken to design the stellarator W7-X. How has this role evolved over time, from the emergence of supercomputing until now? How will this role change in the exascale era? We asked Frank Jenko, head of the Tokamak Theory department at IPP Garching and lead developer of the GENE code.

To set the stage, HPC use in fusion research has come a long way since HPC’s beginnings in the 60s. What were the first uses of HPC in fusion research, and how has this evolved over the years?

HPC has always been extremely important for fusion research, given that the fundamental equations (kinetic or fluid) as well as many physical phenomena (like turbulence) are inherently nonlinear, limiting the capabilities of analytical theory. Initially, the focus was on very simple, highly idealized models, since they were more tractable with the HPC resources of the day. With time, the models became more and more comprehensive and realistic, however, allowing for quantitative comparisons with experimental measurements. This happened first in the context of areas like linear magnetohydrodynamics (MHD) and neoclassical transport, which tend to be more accessible to computation overall. Later, the focus shifted to more complex issues like turbulent transport and nonlinear MHD. More recently, we have come to realize that many physical processes in fusion plasmas that have been investigated in isolation over many years are actually deeply connected, say the physics of energetic particles and turbulent transport. So we are entering the multi-physics, multi-scale era of fusion simulation.

Among the various ways fusion researchers use HPC is for modelling plasma turbulence. Can you explain what makes this application complex, yet worthwhile?

Turbulence is widely considered one of the most important and fascinating unsolved problems in physics. It is a paradigmatic example of nonlinear dynamics in complex systems, involving a continuous exchange of energy between a very large number of degrees of freedom and combining elements of chaos and order in interesting ways. Moreover, turbulence connects fundamental questions in theoretical physics and mathematics with a range of neighboring disciplines, from astrophysics to biophysics. At the same time, turbulence is of immense practical importance in numerous application areas, including weather prediction and combustion. In the context of fusion research, turbulence sets the global energy confinement time, which is of course a key figure of merit of any magnetic confinement fusion device. Therefore, it is our aim to understand, predict, and control turbulent transport, and to study its interactions with other physical processes, like MHD instabilities and edge physics. A predictive capability in the area of plasma turbulence constitutes a key element of a future virtual fusion plasma.

You’ve kindly provided us with a video of a plasma turbulence simulation from GENE-3D, one of the recent gyrokinetic codes developed in your group. (To view the video and its description, click here.) What makes this code and this simulation unique, and how did HPC enable this?

Plasma turbulence simulations are based on the gyrokinetic equations. First attempts to solve these equations on HPC systems, as a proof-of-principle, were undertaken in the 80s and 90s, based on a long list of simplifying assumptions. At this stage, the emphasis was mainly on understanding the fundamental character of plasma turbulence. Starting around 2000, the simulations gradually became more realistic, providing quantitative results which can be compared to experimental findings. The GENE family of codes played an important role in this context. The first version of GENE used a simple flux-tube geometry, minimizing the computational cost. Later, full-volume simulations became possible, but only for axisymmetric devices, i.e., tokamaks. Several years ago, a full-flux-surface version of GENE was developed and applied to stellarators. And finally, in 2020, after a multi-year code development effort, we were able to arrive at GENE-3D, which allows for full-volume simulations for stellarators, including important physical effects like magnetic field fluctuations and collisions. First applications to Wendelstein 7-X have been initiated, enabled by state-of-the-art HPC systems. These systems are vital in allowing us to accurately capture the turbulent dynamics in these complex geometries.

Finally, a new era of HPC, namely the exascale era, is due to begin this year. In your opinion, what avenues of fusion research will this open, and what benefits could this have for the fusion field? What will HPC not be capable of?

The prospects of exascale computing are very intriguing for fusion research. For the first time, we will be able to accurately capture essential aspects of fusion plasmas based on first-principles models, including various interactions between different physical processes. This development will allow us to become truly predictive, extrapolating from existing devices and plasma regimes to future ones with a high level of confidence. Needless to say that such a capability will greatly facilitate the development and optimization of next-step devices and future power plants. While a full-blown virtual tokamak or stellarator may be out of reach for quite some time, critical aspects of fusion physics, from heat and particle exhaust to the avoidance and control of disruptions, will greatly benefit from such efforts. Exascale computing is therefore viewed by many as a likely game changer for fusion research, offering new pathways to guiding and accelerating it. It is the right new "technology" at the right time, promising exciting new R&D opportunities.

More information about GENE-3D, and many other resources, are available on the FuseNet website Educational Materials page.

This article originally appeared on the  website of EUROfusion partner FuseNET.

 

 

 

 

]]>
Highlights RSS-feed Partner News
news-910 Thu, 29 Apr 2021 10:36:00 +0200 Virtual reality guides engineers to perform ITER maintenance works https://www.euro-fusion.org/news/detail/virtual-reality-guides-engineers-to-perform-iter-maintenance-works/ Imagine having to repair the biggest fusion device without being able to step inside. Imagine having to repair the biggest fusion device without being able to step inside. Massive pieces of expensive equipment installed with millimetric precision requiring checks; heavy components which may need to be replaced after time, smaller components difficult to reach with no cameras views to do the job. How does one open the doors of ITER, which holds the key to abundant energy, and gets to fix it? Welcome to the universe of virtual reality visualisation, robotics and software working hand in hand from a distance to let engineers to be hands-on with maintenance.

Europe is responsible for three of the ITER Remote Handling systems, which are progressing in parallel, to support experts with the maintenance of the divertor; the neutral beam; the operation and transport of the  cask and plugs. Regardless of the specificities of these systems, they will need to operate in a seamless manner with the latest robotics technology and software. After testing various products in the market, and assessing their compatibility with the ITER environment, F4E has selected VR4Robots developed by Tree C Technology. VTT, Finland’s Technical Research Centre, carried out the selection process in collaboration with Bernhard Haist, expert in Remote Handling systems.

The tool, will help engineers to visualise maintenance processes, simulate or perform in real time remote handling operations, and be used by more than one users in parallel. Europe is also aiming at another twinning exercise building a bridge between the Genrobot software, which will introduce a sense of coherence amongst the various interfaces of the system, and VR4Robots, which will help the remote operators to see the exact location of the robotics equipment in the vessel with a real-time refresh rate.

“VR4Robots was originally developed for the interactive visualisation of the remote handling operations in JET. Since then, several ITER Parties have adopted VR4Robots digital twin technology, which is also playing an important role in the decommissioning of nuclear reactors worldwide, like in Fukushima,” explains Gerard Weder, CEO of Tree C Technology B.V.  “We are proud that the latest generation of VR4Robots has been selected by F4E, following a thorough evaluation, as the virtual reality system for the remote handling system of the ITER Divertor, and look forward to the collaboration.”

Emilio Ruiz Morales, has been following this subject closely on behalf of F4E. He is the person behind the ambitious plan, to make the various interfaces speak the same language and see with the same pair of eyes. “We needed an efficient and versatile tool to fit the needs of our various systems we are manufacturing. VR4Robots is offering us this flexibility and our ITER counterparts in Japan have opted for the same. Our aim is to test it towards the end of this year in DTP2, Finland, where we have a test facility for the remote handling system of the ITER Divertor,” he explains.

Carlo Damiani, F4E Remote Handling Programme Manager, highlights the importance of this recent development. “It’s amazing and challenging at the same time to develop and deploy all these different technologies for our Remote Handling systems. One day, all of them will work together seamlessly. The operators in the remote handling control room will perform their duties immersed in a reality where virtual and physical objects will interact between them and will allow operators to perform their tasks smoothly and effectively.”

This article originally appeared on the website of EUROfusion consortium partner Fusion for Energy.

 

 

]]>
Highlights RSS-feed Partner News
news-909 Mon, 26 Apr 2021 08:18:00 +0200 Machine learning speeds up modelling of nuclear fusion https://www.euro-fusion.org/news/detail/machine-learning-speeds-up-modelling-of-nuclear-fusion/ News from EUROfusion member DIFFER: Using machine learning is a promising trend in modelling the behaviour of the plasma inside a nuclear fusion reactor. DIFFER researchers are pioneering very fast neural network models for plasma turbulence. On the long road to a future commercial nuclear fusion device, predicting the behaviour of the super hot plasma inside the reactor is one of the crucial building blocks. This building block includes, among others, understanding the heating of the plasma, its magnetohydrodynamic properties and its turbulence.

It is for the turbulence part that DIFFER researchers Jonathan Citrin, Aaron Ho and Karel van de Plassche recently achieved a great speed-up of the modelling time by using neural networks, a specific type of machine learning. The work is detailed in a new paper in the journal Physics of Plasmas, entitled Neural network surrogate of QuaLiKiz using JET experimental data to populate training space.

Bottlenecks

“The future of machine learning in modelling fusion is great”, says Citrin, head of the Integrated Modelling and Transport group at DIFFER. “My long term vision is that we will use neural network surrogates for all sub-models needed to simulate the plasma that presently form computational bottlenecks, for which no other model reduction is feasible. My group is pioneering a neural network model for turbulence, but I am confident that the same technique can also be used for modelling additional physics components.”

10.000x faster

Physicists Karel van de Plassche and Aaron Ho both developed neural network models for plasma turbulence. They demonstrated that their neural network models are accurate enough to replace the currently used reduced-physics model. That model is itself a simplification of the full physical equations that describe the plasma’s behaviour, but is still accurate, and is fast enough to generate extensive training sets. The network is trained on input and output data of the reduced-physics model.

Ho built a model that was trained on data of EUROfusion device JET in the UK. At 10.000 times faster than the original turbulence model, this removes a bottleneck in reactor modelling which as a result became 100 times faster than before. “We also demonstrated that our models have value for the people in the control room”, tells Ho. “We simulated a scenario (planned plasma discharge - editor) fast and accurate enough so that if the experimentalists had a question on scenario design, we were able to give them the answer fast enough. They were impressed with the speed.” Ho successfully defended his PhD-thesis on March 17th 2021.

Van de Plassche developed a model that is slightly less accurate than Ho’s model but can be used on various device, such as the future ITER. Furthermore, it achieved a speed-up of a factor 100.000 as compared to the reduced-physics model. “There is only one other group in the world that also developed a neural network model like ours”, says Van de Plassche. “We want to get as close a possible to a real-time simulation of the plasma, bridging 12 orders of magnitude in calculation speed from simulating the full physical equations.”

Integrated modeling

On April 1 2021 a new European project will start that organises the full integrated modelling of the plasma. DIFFER scientists will play an important role in that project. Citrin: “Thanks to the work of Aaron and Karel our neural network modelling is strongly embedded in the European integrated modelling effort. We are looking forward to this new cooperation.”

The new cooperation might also prepare the way to using the neural network models of the DIFFER-researchers in ITER, the largest experimental fusion device in the world that is presently being built in Cadarache in France. “My ultimate dream is that our neural network models will contribute to the way operators in the control room can do their job”, concludes Citrin.

This article originally appeared on the website of our member DIFFER.

This article originally appeared on the website of EUROfusion consortium member DIFFER.

 

 

]]>
Highlights RSS-feed Member News
news-907 Tue, 20 Apr 2021 11:27:08 +0200 CHIMERA to transform fusion component testing https://www.euro-fusion.org/news/2021/april/chimera-to-transform-fusion-component-testing/ Construction of a unique machine for testing fusion components is underway at EUROfusion partner UKAEA. Highlights RSS-feed news-905 Wed, 07 Apr 2021 11:07:12 +0200 New HPC hub aims to harness the sun's energy https://www.euro-fusion.org/news/2021/april/new-high-performance-computing-hub-aims-to-harness-the-suns-energy/ EPFL will soon be home to a European hub for high-performance computing focused on fusion power – a potential source of clean, risk-free energy. As part of this effort, EPFL’s Swiss Plasma Center will lead a campus-wide, cross-disciplinary research team. Highlights RSS-feed