From MIT News: “On the right path to fusion energy”

MIT News
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From MIT News

December 21, 2018
Peter Dunn

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A fusion power plant could provide clean, carbon-free energy with an essentially unlimited fuel supply. From the point of view of electrical power generation, the fusion device is just another heat source that could be used in a conventional thermal conversion cycle. Image courtesy of PSFC, adapted from Wikimedia Commons.

A new report on the development of fusion as an energy source, written at the request of the U.S. Secretary of Energy, proposes adoption of a national fusion strategy that closely aligns with the course charted in recent years by MIT’s Plasma Science and Fusion Center (PSFC) and privately funded Commonwealth Fusion Systems (CFS), a recent MIT spinout.

Fusion technology has long held the promise of producing safe, abundant, carbon-free electricity, while struggling to overcome the daunting challenges of creating and harnessing fusion reactions to produce net energy gain. But the Consensus Study Report from the National Academies of Science, Engineering, and Medicine states that magnetic-confinement fusion technology (an MIT focus since the 1970s) is now “sufficiently advanced to propose a path to demonstrate fusion generated energy within the next several decades.”

It recommends continued U.S. participation in the international ITER fusion facility project and “a national program of accompanying research and technology leading to the construction of a compact pilot plant that produces electricity from fusion at the lowest possible capital cost.”

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

That approach (which the report says would require up to $200 million in additional annual funding for several decades) leverages opportunities presented by new-generation superconducting magnets, reactor materials, simulators, and other relevant technologies. Of particular emphasis from the committee is the advances in high-temperature superconducting magnets which can access higher fields and smaller machines. The report recommends a U.S. program to prove out high-field large-bore magnets. They are seen as enabling faster and less-costly cycles of learning and development than extremely large experiments like ITER, which will not come on line until 2025, while still benefitting from the knowledge that emerges from those programs.

This smaller-faster-cheaper approach is embodied in the SPARC reactor concept, which was developed at the PSFC and forms the foundation of CFS’s aggressive effort to demonstrate energy-gain fusion by the mid-2020s and produce practical reactor designs by the early 2030s.

MIT SPARC fusion reactor tokamak

This approach is based on the similar conclusion that high-field high-temperature magnets represent a game-changing technology. A $30 million program between CFS and MIT to demonstrate the high-field large bore superconducting magnets is underway at MIT and is a key step to a compact fusion energy system. Despite a handful of other privately funded fusion companies having offered roughly comparable timelines, the National Academies report does not envision demonstration fusion reactors appearing until the 2050 time frame.

The report also affirms that the scientific underpinnings of the tokamak approach have been strengthened over the previous decade, giving increasing confidence that this approach, which is the basis of ITER and SPARC, is capable of achieving net energy gain and forming the basis for a power plant. Based on this increased confidence the committee recommends moving forward with technology developments for a pilot power plant that would put power on the grid.

“The National Academies are a very thoughtful organization, and they’re typically very conservative,” says Bob Mumgaard, chief executive officer of CFS. “We’re glad to see them come out with a message that it’s time to move into fusion, and that compact and economical is the way to go. We think development should go faster, but it gives validation to people who want to tackle the challenge and lays out things we can do in the U.S. that will lead toward putting power on the grid.”

Andrew Holland, director of the recently formed Fusion Industry Association and Senior Fellow for Energy and Climate at the American Security Project, notes that the report’s authors were charged with creating “a consensus science report that reflects current pathways, and the current pathway is to build ITER and go through the experimental process there, while meanwhile designing a pilot plant, DEMO.”

Shifting the consensus toward a faster way forward, adds Holland, will require experimental results from companies like CFS. “That’s why it’s notable to have privately funded companies in the U.S. and around the world pursuing the scientific results that will bear this out. And it’s certainly important that this study is aimed at getting the government-based science community to think about a strategic plan. It should be seen as part of a starting gun for the fusion community coming together and organizing its own process.”

Or, as Martin Greenwald, deputy director of the PSFC and a veteran fusion researcher, puts it, “There’s a tendency in our community to argue about a 20-year plan or a 30-year plan, but we don’t want to take our eyes off what we need to do in the next three to five years. We might not have consensus on the long scale, but we need one for what to do now, and that’s been the consistent message since we announced the SPARC project — engaging the broader community and taking the initiative.

“The key thing to us is that if fusion is going to have an impact on climate change, we need answers quickly, we can’t wait until the end of century, and that’s driving the schedule. The private money that’s coming in helps, but public funding should engage with and complement that. Each side has an appropriate role. National labs don’t build power plants, and private companies don’t do basic research.”

While several approaches to fusion are being pursued in public and private organizations, the National Academies report focuses exclusively on magnetic confinement technology. This reflects the report’s role in the Department of Energy’s response to a 2016 Congressional request for information on U.S. participation in ITER, a magnetic-confinement project. The report committee’s 19 experts, who conducted two years of research, were also charged with exploring related questions of “how best to advance the fusion sciences in the U.S.” and “the scientific justification and needs for strengthening the foundations for realizing fusion energy given a potential choice of U.S. participation or not in the ITER project.”

The report’s publication comes at a time of renewed activity and interest in fusion energy, with some 20 private companies pursuing its development, increased funding in the most recent federal budget, and the formation of the Fusion Industry Association to advocate for the community as a whole. But the report cautions that “the absence of a long-term research strategy for the United States is particularly evident when compared to the plans of our international partners.”

That situation may be evolving. “We had a very nice meeting of stakeholders a month and a half ago in DC, and there was a lot of resonance among private companies, the research community, the Department of Energy, and Congressional staffers from both parties,” says Greenwald. “It seems like there’s momentum, though we don’t know yet just what form it will take.” He adds that the establishment of an industry association is very helpful for navigating and communicating in Washington.

“We would love to see the government have a role in things that lift all fusion companies, like advanced materials labs, the process of extracting heat from reactors, additive manufacturing, simulations, and other tools,” says Mumgaard. “There are many opportunities for collaboration and cooperation; every company will have a different mix of partnerships, even on personnel exchange as we do with MIT.”

See the full article here .


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From PPPL: “Newest supercomputer to help develop fusion energy in international device”


From PPPL

July 25, 2018
John Greenwald

Scientists led by Stephen Jardin, principal research physicist and head of the Computational Plasma Physics Group at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), have won 40 million core hours of supercomputer time to simulate plasma disruptions that can halt fusion reactions and damage fusion facilities, so that scientists can learn how to stop them. The PPPL team will apply its findings to ITER, the international tokamak under construction in France to demonstrate the practicality of fusion energy. The results could help ITER operators mitigate the large-scale disruptions the facility inevitably will face.

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

Receipt of the highly competitive 2018 ASCR Leadership Computing Challenge (ALCC) award entitles the physicists to simulate the disruption on Cori, the newest and most powerful supercomputer at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory.

NERSC Cray Cori II supercomputer at NERSC at LBNL, named after Gerty Cori, the first American woman to win a Nobel Prize in science

NERSC, a U.S. Department of Energy Office of Science user facility, is a world leader in accelerating scientific discovery through computation.

Model the entire disruption

“Our objective is to model development of the entire disruption from stability to instability to completion of the event,” said Jardin, who has led previous studies of plasma breakdowns. “Our software can now simulate the full sequence of an ITER disruption, which could not be done before.”

Fusion, the power that drives the sun and stars, is the fusing of light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

The award of 40 million core hours on Cori, a supercomputer named for Nobel Prize-winning biochemist Gerty Cori that has hundreds of thousands of cores that act in parallel, will enable the physicists to complete in weeks what a single-core laptop computer would need thousands of years to accomplish. The high-performance computing machine will scale up simulations for ITER and perform other tasks that less powerful computers would be unable to complete.

On Cori the team will run the M3D-C1 code primarily developed by Jardin and PPPL physicist Nate Ferraro. The code, developed and upgraded over a decade, will evolve the disruption simulation forward in a realistic manner to produce quantitative results. PPPL now uses the code to perform similar studies for current fusion facilities for validation.

The simulations will also cover strategies for the mitigation of ITER disruptions, which could develop from start to finish within roughly a tenth of a second. Such strategies require a firm understanding of the physics behind mitigations, which the PPPL team aims to create. Together with Jardin and Ferraro on the team are physicist Isabel Krebs and computational scientist Jin Chen.

See the full article here .


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Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

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From Max Planck Institute for Plasma Physics: IPP’s ELISE test rig achieves first ITER objective

MPIPP bloc

From Max Planck Institute for Plasma Physics

July 04, 2018
Isabella Milch

Neutral-particle heating for ITER / Fast-hydrogen-particle beam for plasma heating.

The heating beam in the ELISE test rig at Max Planck Institute for Plasma Physics (IPP) at Garching near Munich has attained the values needed for ITER: It can maintain for 1,000 seconds a particle beam composed of negatively charged hydrogen ions with the current strength of 23 amperes desired by ITER.
ELISE is serving to prepare one of the heating methods that are to bring the plasma of the international ITER test reactor to several million degrees. The core piece is a novel high-frequency ion source developed at IPP that produces the high-energy particle beam.

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One of the accelerator grids that get the hydrogen atoms in the ELISE ion source to the right velocity. The particle beam is extracted as individual beams through 640 small apertures in the grid surface of about a square metre. Photo: IPP

The international ITER (Latin for ‘the way’) test reactor, now being built in France as a world-wide cooperation, is to demonstrate that a fusion fire supplying energy is possible.

Iter experimental tokamak nuclear fusion reactor that is being built next to the Cadarache facility in Saint Paul les-Durance south of France

Like the sun, a future fusion power plant is to derive energy from fusion of atomic nuclei. The fuel, viz. a hydrogen plasma, has to be confined without wall contact in a magnetic field cage and be heated to ignition temperatures exceeding 100 million degrees. ITER is to produce 500 megawatts of fusion power, this being ten times as much as needed beforehand to heat the plasma.

About half of this plasma heating will be provided by the neutral-particle heating: Fast hydrogen atoms injected through the magnetic field cage into the plasma transfer their energy to the plasma particles by way of collisions. For this purpose, an ion source produces from hydrogen gas charged hydrogen ions that are accelerated by high voltage and finally re-neutralised so that, as fast hydrogen atoms, they can penetrate into the plasma unhampered by the magnetic field.

This method enables present-day heating systems, e.g. that for IPP’s ASDEX Upgrade fusion device at Garching, to bring the plasma to a multiple of the sun’s temperature at the click of a button. The ITER large-scale device, however, presents higher requirements: For example, the particle beams have to be much thicker and the individual particles be much faster than hitherto so that they can penetrate the voluminous ITER plasma to a sufficient depth. Two particle beams with cross-sections about the size of an ordinary door are to feed 16.5 megawatts of heating power into the ITER plasma. ITER will thus greatly surpass the particle beams used in today’s fusion devices, which make do with cross-sections about the size of a dinner plate and much lower velocity.

Therefore, instead of the positively charged ions used hitherto, which cannot be effectively neutralised at high energies, for ITER it is necessary to use negatively charged ions, which are extremely fragile. A high-frequency ion source developed for the purpose at IPP was incorporated in the ITER design. At the end of 2012 IPP was given a contract for further development and adaptions to ITER requirements.

The ELISE (Extraction from a Large Ion Source Experiment) test rig constitutes a source half as large as that for ITER later. ELISE generates an ion beam with a cross-sectional area of about a square metre. The increased format made it necessary to revise the previous technical solutions for the heating method (see PI 2/2015). ELISE has advanced step by step to new orders of magnitude. “Now we are able to produce the desired 23-ampere particle beam of negatively charged hydrogen ions, stable, homogeneous and lasting 1,000 seconds”, states Professor Dr Ursel Fantz, head of IPP’s ITER Technology and Diagnostics division. “The gas pressure in the source and the quantity of electrons retained also meet ITER’s requirements”. It was only the current density of the ion beam that was not quite attained, this being due to the limited power capability of the high-voltage supply available.

Where does it go from here?

Now that ELISE has attained the ion current required by ITER with ordinary hydrogen it is time to tackle the second part of the task and produce ion beams from deuterium, the heavy isotope of hydrogen, albeit not just for 1,000 seconds, but for a whole hour. The system in the original size will be investigated by Italy’s fusion institute, ENEA, in Padua, who will collaborate with IPP. The SPIDER (Source for Production of Ions of Deuterium Extracted from Radio-frequency Plasma) test device was commissioned at Padua in early June. The target data: one-hour pulses with full ITER beam cross-section and 6 megawatts of power in hydrogen and deuterium.

See the full article here .


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MPIPP campus

The Max Planck Institute of Plasma Physics (Max-Planck-Institut für Plasmaphysik, IPP) 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)
the experimental stellarator Wendelstein 7-AS (in operation until 2002)
the experimental stellarator Wendelstein 7-X (awaiting licensing)
a tandem accelerator

It also cooperates with the ITER and JET projects.

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From AIP: “Lifetime of primary runaway electrons estimated for high-plasma-current fusion devices”

AIP Publishing Bloc

American Institute of Physics

November 2017
Meeri Kim

Analysis of field and collision influence on runaway electrons produced during plasma disruptions provides insight into lifetime trends.

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No image caption or credit.

For ITER and other high-plasma-current fusion devices, runaway electrons are a matter of concern.

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

[ITER, way behind schedule and way over budget, is about as good as it gets in the search for Fusion Technology, which has been 30 years away for the last thirty years.]

These highly accelerated electrons, produced in great numbers during plasma disruptions, can form a runaway beam that hits and damages the wall of the machine.

A recent U.S. initiative called SCREAM (Simulation Center for Runaway Electron Avoidance and Mitigation) combines theoretical models with advanced simulation and analysis to address the runaway problem. As part of SCREAM, two physicists used kinetic analysis to predict the lifetime of primary runaway electrons, reporting the results in Physics of Plasmas.

The authors wanted to understand the distribution of primary runaway electrons by taking into account the interplay of three factors: acceleration by electric field, collisions with plasma electrons and ions, and synchrotron losses. Their analysis dealt with the kinetic equation for relativistic electrons in a straight and homogeneous magnetic field, which they were able to simplify and rescale to highlight its similarity features.
They found that the lifetime of seed runaways increases exponentially with the electric field, with the rate depending on a combination of parameters collectively called “alpha,” that includes the effects of ion charge and synchrotron time scale. For alpha much less than one, the lifetimes can be long when the electric field is only slightly about the renowned Connor-Hastie critical value, when the friction, or drag, on the relativistic electrons from ion collisions becomes energy independent and the electrons can be accelerated continuously. For alpha much larger than one, significantly stronger electric fields are necessary for runaway seed electron survival.

Long-lived runaway electrons have greater opportunity to multiply via an avalanche effect. Knowing the parameter range that creates long lifetimes will inform ITER researchers about what regimes to avoid in planned experiments.

See the full article here .

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AIP serves a federation of physical science societies in a common mission to promote physics and allied fields.

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From BNL: “Designing New Metal Alloys Using Engineered Nanostructures”

Brookhaven Lab

Stony Brook University assistant professor Jason Trelewicz brings his research to design and stabilize nanostructures in metals to Brookhaven Lab’s Center for Functional Nanomaterials.

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Materials scientist Jason Trelewicz in an electron microscopy laboratory at Brookhaven’s Center for Functional Nanomaterials, where he characterizes nanoscale structures in metals mixed with other elements.

Materials science is a field that Jason Trelewicz has been interested in since he was a young child, when his father—an engineer—would bring him to work. In the materials lab at his father’s workplace, Trelewicz would use optical microscopes to zoom in on material surfaces, intrigued by all the distinct features he would see as light interacted with different samples.

Now, Trelewicz—an assistant professor in the College of Engineering and Applied Sciences’ Department of Materials Science and Chemical Engineering with a joint appointment in the Institute for Advanced Computational Science at Stony Brook University and principal investigator of the Engineered Metallic Nanostructures Laboratory—takes advantage of the much higher magnifications of electron microscopes to see tiny nanostructures in fine detail and learn what happens when they are exposed to heat, radiation, and mechanical forces. In particular, Trelewicz is interested in nanostructured metal alloys (metals mixed with other elements) that incorporate nanometer-sized features into classical materials to enhance their performance. The information collected from electron microscopy studies helps him understand interactions between structural and chemical features at the nanoscale. This understanding can then be employed to tune the properties of materials for use in everything from aerospace and automotive components to consumer electronics and nuclear reactors.

Since 2012, when he arrived at Stony Brook University, Trelewicz has been using the electron microscopes and the high-performance computing (HPC) cluster at the Center for Functional Nanomaterials (CFN)—a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven National Laboratory—to perform his research.

“At the time, I was looking for ways to apply my idea of stabilizing nanostructures in metals to an application-oriented problem,” said Trelewicz. “I’ve long been interested in nuclear energy technologies, initially reading about fusion in grade school. The idea of recreating the processes responsible for the energy we receive from the sun here on earth was captivating, and fueled my interest in nuclear energy throughout my entire academic career. Though we are still very far away from a fusion reactor that generates power, a large international team on a project under construction in France called ITER is working to demonstrate a prolonged fusion reaction at a large scale.”

Plasma-facing materials for fusion reactors

Nuclear fusion—the reaction in which atomic nuclei collide—could provide a nearly unlimited supply of safe, clean energy, like that naturally produced by the sun through fusing hydrogen nuclei into helium atoms. Harnessing this carbon-free energy in reactors requires generating and sustaining a plasma, an ionized gas, at the very high temperatures at which fusion occurs (about six times hotter than the sun’s core) while confining it using magnetic fields. Of the many challenges currently facing fusion reactor demonstrations, one of particular interest to Trelewicz is creating viable materials to build a reactor.

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A model of the ITER tokamak, an experimental machine designed to harness the energy of fusion. A powerful magnetic field is used to confine the plasma, which is held in a doughnut-shaped vessel. Credit: ITER Organization.

“The formidable materials challenges for fusion are where I saw an opportunity for my research—developing materials that can survive inside the fusion reactor, where the plasma will generate high heat fluxes, high thermal stresses, and high particle and neutron fluxes,” said Trelewicz. “The operational conditions in this environment are among the harshest in which one could expect a material to function.”

A primary candidate for such “plasma-facing material” is tungsten, because of its high melting point—the highest one among metals in pure form—and low sputtering yield (number of atoms ejected by energetic ions from the plasma). However, tungsten’s stability against recrystallization, oxidation resistance, long-term radiation tolerance, and mechanical performance are problematic.

Trelewicz thinks that designing tungsten alloys with precisely tailored nanostructures could be a way to overcome these problems. In August, he received a $750,000 five-year award from the DOE’s Early Career Research Program to develop stable nanocrystalline tungsten alloys that can withstand the demanding environment of a fusion reactor. His research is combining simulations that model atomic interactions and experiments involving real-time ion irradiation exposure and mechanical testing to understand the fundamental mechanisms responsible for the alloys’ thermal stability, radiation tolerance and mechanical performance. The insights from this research will inform the design of more resilient alloys for fusion applications.

In addition to the computational resources they use at their home institution, Trelewicz and his lab group are using the HPC cluster at the CFN—and those at other DOE facilities, such as Titan at Oak Ridge Leadership Computing Facility (a DOE Office of Science User Facility at Oak Ridge National Laboratory)—to conduct large-scale atomistic simulations as part of the project.

ORNL Cray Titan XK7 Supercomputer

“The length scales of the structures we want to design into our materials are on the order of a few nanometers to 100 nanometers, and a single simulation can involve up to 10 million atoms,” said Trelewicz. “Using HPC clusters, we can build a system atom-by-atom, representative of the structure we would like to explore experimentally, and run simulations to study the response of that system under various external stimuli. For example, we can fire a high-energy atom into the system and watch what happens to the material and how it evolves, hundreds or thousands of times. Once damage has accumulated in the structure, we can simulate thermal and mechanical forces to understand how defect structure impacts other behavior.”

These simulations inform the structures and chemistries of experimental alloys, which Trelewicz and his students fabricate at Stony Brook University through high-energy milling. To characterize the nanoscale structure and chemical distribution of the engineered alloys, they extensively use the microscopy facilities at the CFN—including scanning electron microscopes, transmission electron microscopes, and scanning transmission electron microscopes. Imaging is conducted at high resolution and often combined with heating within the microscope to examine in real time how the structures evolve with temperature. Experiments are also conducted at other DOE national labs, such as Sandia through collaboration with materials scientist Khalid Hattar of the Ion Beam Laboratory. Here, students in Trelewicz’s research group simultaneously irradiate the engineered alloys with an ion beam and image them with an electron microscope over the course of many days.

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Trelewicz and his students irradiated a nanostructured tungsten-titanium alloy with high-energy gold ions to explore the radiation tolerance of this novel material.

“Though this damage does not compare to what the material would experience in a reactor, it provides a starting point to evaluate whether or not the engineered material could indeed address some of the limitations of tungsten for fusion applications,” said Trelewicz.

Electron microscopy at the CFN has played a key role in an exciting discovery that Trelewicz’s students recently made: an unexpected metastable-to-stable phase transition in thin films of nanostructured tungsten. This phase transition drives an abnormal “grain” growth process in which some crystalline nanostructure features grow very dramatically at the expense of others. When the students added chromium and titanium to tungsten, this metastable phase was completely eliminated, in turn enhancing the thermal stability of the material.

“One of the great aspects of having both experimental and computational components to our research is that when we learn new things from our experiments, we can go back and tailor the simulations to more accurately reflect the actual materials,” said Trelewicz.

Other projects in Trelewicz’s research group.

The research with tungsten is only one of many projects ongoing in the Engineered Metallic Nanostructures Laboratory.

“All of our projects fall under the umbrella of developing new metal alloys with enhanced and/or multifunctional properties,” said Trelewicz. “We are looking at different strategies to optimize material performance by collectively tailoring chemistry and microstructure in our materials. Much of the science lies in understanding the nanoscale mechanisms that govern the properties we measure at the macroscale.”

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Jason Trelewicz (left) with Olivia Donaldson, who recently graduated with her PhD from Trelewicz’s group, and Jonathan Gentile, a current doctoral student, in front of the scanning electron microscope/focused-ion beam at Stony Brook University’s Advanced Energy Center. Credit: Stony Brook University.

Through a National Science Foundation CAREER (Faculty Early Career Development Program) award, Trelewicz and his research group are exploring another class of high-strength alloys—amorphous metals, or “metallic glasses,” which are metals that have a disordered atomic structure akin to glass. Compared to everyday metals, metallic glasses are often inherently higher strength but usually very brittle, and it is difficult to make them in large parts such as bulk sheets. Trelewicz’s team is designing interfaces and engineering them into the metallic glasses—initially iron-based and later zirconium-based ones—to enhance the toughness of the materials, and exploring additive manufacturing processes to enable sheet-metal production. They will use the Nanofabrication Facility at the CFN to fabricate thin films of these interface-engineered metallic glasses for in situ analysis using electron microscopy techniques.

In a similar project, they are seeking to understand how introducing a crystalline phase into a zirconium-based amorphous alloy to form a metallic glass matrix composite (composed of both amorphous and crystalline phases) augments the deformation process relative to that of regular metallic glasses. Metallic glasses usually fail catastrophically because strain becomes localized into shear bands. Introducing crystalline regions in the metallic glasses could inhibit the process by which strain localizes in the material. They have already demonstrated that the presence of the crystalline phase fundamentally alters the mechanism through which the shear bands form.

Trelewicz and his group are also exploring the deformation behavior of metallic “nanolaminates” that consist of alternating crystalline and amorphous layers, and are trying to approach the theoretical limit of strength in lightweight aluminum alloys through synergistic chemical doping strategies (adding other elements to a material to change its properties).

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Trelewicz and his students perform large-scale atomistic simulations to explore the segregation of solute species to grain boundaries (GBs)—interfaces between grains—in nanostructured alloys, as shown here for an aluminum-magnesium (Al-Mg) system, and its implications for the governing deformation mechanisms. They are using the insights gained through these simulations to design lightweight alloys with theoretical strengths.

“We leverage resources of the CFN for every project ongoing in my research group,” said Trelewicz. “We extensively use the electron microscopy facilities to look at material micro- and nanostructure, very often at how interfaces are coupled with compositional inhomogeneities—information that helps us stabilize and design interfacial networks in nanostructured metal alloys. Computational modeling and simulation enabled by the HPC clusters at the CFN informs what we do in our experiments.”

Beyond his work at CFN, Trelewicz collaborates with his departmental colleagues to characterize materials at the National Synchrotron Light Source II—another DOE Office of Science User Facility at Brookhaven.

BNL NSLS-II


BNL NSLS II

“There are various ways to characterize structural and chemical inhomogeneities,” said Trelewicz. “We look at small amounts of material through the electron microscopes at CFN and on more of a bulk level at NSLS-II through techniques such as x-ray diffraction and the micro/nano probe. We combine this local and global information to thoroughly characterize a material and use this information to optimize its properties.”

Future of next-generation materials

When he is not doing research, Trelewicz is typically busy with student outreach. He connects with the technology departments at various schools, providing them with materials engineering design projects. The students not only participate in the engineering aspects of materials design but are also trained on how to use 3D printers and other tools that are critical in today’s society to manufacture products more cost effectively and with better performance.

Going forward, Trelewicz would like to expand his collaborations at the CFN and help establish his research in metallic nanostructures as a core area supported by CFN and, ultimately, DOE, to achieve unprecedented properties in classical materials.

“Being able to learn something new every day, using that knowledge to have an impact on society, and seeing my students fill gaps in our current understanding are what make my career as a professor so rewarding,” said Trelewicz. “With the resources of Stony Brook University, nearby CFN, and other DOE labs, I have an amazing platform to make contributions to the field of materials science and metallurgy.”

Trelewicz holds a bachelor’s degree in engineering science from Stony Brook University and a doctorate in materials science and engineering with a concentration in technology innovation from MIT. Before returning to academia in 2012, Trelewicz spent four years in industry managing technology development and transition of harsh-environment sensors produced by additive manufacturing processes. He is the recipient of a 2017 Department of Energy Early Career Research Award, 2016 National Science Foundation CAREER award, and 2015 Young Leaders Professional Development Award from The Minerals, Metals & Materials Society (TMS), and is an active member of several professional organizations, including TMS, the Materials Research Society, and ASM International (the Materials Information Society).

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One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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From PPPL: “PPPL completes shipment of electrical components to power site for ITER, the international fusion experiment”


PPPL

October 16, 2017
Jeanne Jackson DeVoe

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Electrical components procured by PPPL. Pictured clockwise: switchgear, HV protection and control cubicles, resistors, and insulators. (Photo by Photo courtesy of © ITER Organization, http://www.iter.org/)

The arrival of six truckloads of electrical supplies at a warehouse for the international ITER fusion experiment on Oct. 2 brings to a successful conclusion a massive project that will provide 120 megawatts of power – enough to light up a small city − to the 445-acre ITER site in France.

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

The Princeton Plasma Physics Laboratory (PPPL), with assistance from the Department of Energy’s Princeton Site Office, headed the $34 million, five-year project on behalf of US ITER to provide three quarters of the components for the steady-state electrical network (SSEN), which provides electricity for the lights, pumps, computers, heating, ventilation and air conditioning to the huge fusion energy experiment. ITER connected the first transformer to France’s electrical grid in March. The European Union is providing the other 25 percent.

The shipment was the 35th and final delivery of equipment from companies all over the world, including from the United States over the past three years.

“I think it’s a great accomplishment to finish this,” said Hutch Neilson, head of ITER Fabrication. “The successful completion of the SSEN program is a very important accomplishment both for the US ITER project and for PPPL as a partner in the US ITER project.”

The six trucks that arrived carried a total of 63 crates of uninterruptible power supply equipment weighing 107 metric tons. The trucks took a seven-hour, 452-mile journey from Gutor UPS and Power Conversion in Wettingen, Switzerland, northwest of Zurich, to an ITER storage facility in Port-Saint-Louis-Du-Rhône, France. The equipment will eventually be used to provide emergency power to critical ITER systems in the event of a power outage.

“This represents the culmination of a very complex series of technical specifications and global purchases, and we are grateful to the entire PPPL team and their vendors for outstanding commitment and performance”, said Ned Sauthoff, director of the US ITER Project Office at Oak Ridge National Laboratory, where all U.S. contributions to ITER are managed for the U.S. Department of Energy’s Office of Science.

A device known as a tokamak, ITER will be the largest and most powerful fusion machine in the world. Designed to produce 500 megawatts of fusion power for 50 megawatts of input power, it will be the first fusion device to create net energy – it will get more energy out than is put in. Fusion is the process by which stars like the sun create energy – the fusing of light elements

A separate electrical system for the pulsed power electrical network (PPEN), procured by China, will power the ITER tokamak.

The first SSEN delivery in 2014 was among the first plant components to be delivered to the ITER site. The SSEN project is now one of the first U.S. packages to be completed in its entirety, Neilson said. He noted that the final shipment arrived 10 days ahead of PPPL’s deadline.

In addition to the electrical components, PPPL is also responsible for seven diagnostic instruments and for integrating the instruments inside ITER port plugs. While PPPL is continuing work on an antenna for one diagnostic, most of the diagnostic and port integration work has been put on hold amid uncertainty over U.S. funding for its contributions to ITER.

The SSEN project was a complex enterprise. PPPL researched potential suppliers, solicited and accepted bids, and oversaw the production and testing of electrical components in 16 separate packages worth a total of about $30 million. The effort involved PPPL engineers, as well as procurement and quality assurance staff members who worked to make sure that the components met ITER specifications and would do exactly what they are supposed to do. “It’s really important that we deliver to ITER equipment that exactly meets the requirements they specify and that it be quality equipment that doesn’t give them trouble down the road,” Neilson said. “So every member of the team makes sure that gets done.”

Many of the components were for the high-voltage switchyard. A massive transformer procured by PPPL was connected to the French electrical grid in March. PPPL procured and managed the purchase and transportation of the 87-ton transformer and three others, which were built in South Korea by Hyundai Heavy Industries, a branch of the company known for producing cars. =

The SSEN components came from as close to home as Mount Pleasant, Pennsylvania, to as far away as Turkey, with other components coming from Mexico, Italy, Spain, France, Germany, South Korea and the Netherlands.

John Dellas, the head of electrical systems and the team leader for the project, has been working on the ITER SSEN project for the entire five years of the program. He traveled to Schweinfurt, Germany, to oversee testing of the control and protection systems for the high-voltage switchyard.

Dellas took over the project from Charles Neumeyer after Neumeyer became engineering director for the NSTX-U Recovery Project last year. Dellas said Neumeyer deserves most of the credit for the program. “Charlie took the team down to the 10-yard line and I put everything in the end zone,” Dellas said. “I was working with Charlie but Charlie was the quarterback.”

Neumeyer worked on the project from 2006, when the project was in the planning stages, until 2016. He said he was happy to see the project completed. “It’s very gratifying to see roughly 10 years of work come to a satisfying conclusion under budget and on schedule,” he said.

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PPPL campus

Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

#applied-research-technology, #fusion-technology, #iter, #physics, #pppl, #ssen-steady-state-electrical-network

From PPPL: “Research led by PPPL provides reassurance that heat flux will be manageable in ITER”


PPPL

September 26, 2017
John Greenwald

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A major issue facing ITER, the international tokamak under construction in France that will be the first magnetic fusion device to produce net energy, is whether the crucial divertor plates that will exhaust waste heat from the device can withstand the high heat flux, or load, that will strike them. Alarming projections extrapolated from existing tokamaks suggest that the heat flux could be so narrow and concentrated as to damage the tungsten divertor plates in the seven-story, 23,000 ton tokamak and require frequent and costly repairs. This flux could be comparable to the heat load experienced by spacecraft re-entering Earth’s atmosphere.

New findings of an international team led by physicist C.S. Chang of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) paint a more positive picture. Results of the collaboration, which has spent two years simulating the heat flux, indicate that the width could be well within the capacity of the divertor plates to tolerate.

Good news for ITER

“This could be very good news for ITER,” Chang said of the findings, published in August in the journal Nuclear Fusion. “This indicates that ITER can produce 10 times more power than it consumes, as planned, without damaging the divertor plates prematurely.”

At ITER, spokesperson Laban Coblentz, said the simulations were of great interest and highly relevant to the ITER project. He said ITER would be keen to see experimental benchmarking, performed for example by the Joint European Torus (JET) at the Culham Centre for Fusion Energy in the United Kingdom, to strengthen confidence in the simulation results.

Joint European Torus, at the Culham Centre for Fusion Energy in the United Kingdom

Chang’s team used the highly sophisticated XGC1 plasma turbulence computer simulation code developed at PPPL to create the new estimate. The simulation projected a width of 6 millimeters for the heat flux in ITER when measured in a standardized way among tokamaks, far greater than the less-than 1 millimeter width projected through use of experimental data.

Deriving projections of narrow width from experimental data were researchers at major worldwide facilities. In the United States, these tokamaks were the National Spherical Torus Experiment before its upgrade at PPPL; the Alcator C-Mod facility at MIT, which ceased operations at the end of 2016; and the DIII-D National Fusion Facility that General Atomics operates for the DOE in San Diego.

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National Spherical Torus Experiment at PPPL

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Alcator C-Mod tokamak at MIT

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DIII-D National Fusion Facility, San Diego

Widely different conditions

The discrepancy between the experimental projections and simulation predictions, said Chang, stems from the fact that conditions inside ITER will be too different from those in existing tokamaks for the empirical predictions to be valid. Key differences include the behavior of plasma particles within today’s machines compared with the expected behavior of particles in ITER. For example, while ions contribute significantly to the heat width in the three U.S. machines, turbulent electrons will play a greater role in ITER, rendering extrapolations unreliable.

Chang’s team used basic physics principles, rather than empirical projections based on the data from existing machines, to derive the simulated wider prediction. The team first tested whether the code could predict the heat flux width produced in experiments on the U.S. tokamaks, and found the predictions to be valid.

Researchers then used the code to project the width of the heat flux in an estimated model of ITER edge plasma. The simulation predicted the greater heat-flux width that will be sustainable within the current ITER design.

Supercomputers enabled simulation

Supercomputers made this simulation possible. Validating the code on the existing tokamaks and producing the findings took some 300 million core hours on Titan and Cori, two of the most powerful U.S. supercomputers, housed at the DOE’s Oak Ridge Leadership Computing Facility and the National Energy Research Scientific Computing Center, respectively.

ORNL Cray XK7 Titan Supercomputer

NERSC Cray Cori II supercomputer

A core hour is one processor, or core, running for one hour.

Researchers from eight U.S. and European institutions collaborated on this research. In addition to PPPL, the institutions included ITER, the Culham Centre for Fusion Energy, the Institute of Atomic and Subatomic Physics at the Technical University of Vienna, General Atomics, MIT, Oak Ridge National Laboratory and Lawrence Livermore National Laboratory.

Support for this work comes from the DOE Office of Science Offices of Fusion Energy Sciences and Office of Advanced Scientific Computing Research.

See the full article here .

Please help promote STEM in your local schools.

STEM Icon

Stem Education Coalition


PPPL campus

Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

#applied-research-technology, #fusion-technology, #iter, #pppl-princeton-plasma-physics-laboratory