It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, January 17, 2025
SUPERGLUE IS TOXIC
Polymer research shows potential replacement for common superglues with a reusable and biodegradable alternative
Researchers have developed an adhesive polymer that is stronger than current commercially available options while also being biodegradable, tunable, and reusable
Credit: Please credit Colorado State University Department of Chemistry
EMBARGO: THIST CONTENT IS UNDER EMBARGO UNTIL 2 PM U.S. EASTERN STANDARD TIME ON JANUARY 16, 2025. INTERESTED MEDIA MAY RECIVE A PREVIEW COPY OF THE JOURNAL ARTICLE IN ADVANCE OF THAT DATE OR CONDUCT INTERVIEWS, BUT THE INFORMATION MAY NOT BE PUBLISHED, BROADCAST, OR POSTED ONLINE UNTIL AFTER THE RELEASE WINDOW.
Researchers at Colorado State University and their partners have developed an adhesive polymer that is stronger than current commercially available options while also being biodegradable and reusable. The findings – described in Science – show how the common, naturally occurring polymer P3HB can be chemically re-engineered for use as a strong yet sustainable bonding agent.
Adhesives are commonly used in automotives, packaging, electronics, solar cells and construction, among many other areas. Together they make up a roughly $50 billion industry that supports much of our modern life but also contributes to the mounting issue of plastic waste. The paper describes the team’s work using experimental, simulation and process modeling to develop a replacement polymer.
The project was led by University Distinguished Professor Eugene Chen in the Department of Chemistry. Other partners on the paper include Gregg Beckham at the National Renewable Energy Laboratory and Professor Ting Xu at the University of California, Berkley and researchers from their groups.
Chen said that poly(3-hydroxybutyrate), or P3HB, is a natural, biobased and biodegradable polymer that can be produced by microbes under the right biological conditions. While the polymer is not adhesive when made that way, his lab was able to chemically re-engineer its structure to now deliver stronger adhesion than the common petroleum-derived, nonbiodegradable options when used on various substrates or surfaces such as aluminum, glass and wood. The adhesion strength of the re-engineered P3HB can also be tuned to accommodate different application needs.
The findings are part of a larger goal by Chen’s group to improve and expand our ability to tackle the global plastics pollution crisis. His team is involved in many efforts to develop chemically recyclable, biodegradable and, overall, more sustainable alternatives to today’s plastic materials. He said that while many people inherently recognize the life cycle issues that come with a disposable water bottle, adhesives present more daunting issues with fewer potential solutions.
“Petroleum-based thermoset adhesives such as Gorilla Glue and J-B Weld, along with thermoplastic hot melts, can be very difficult or even impossible to recycle or recover – primarily because of their strong bonds to other materials,” he said. “Our approach instead offers a biodegradable material that can be used in a variety of industries with tunable or even higher strength compared to those options.”
Ethan Quinn is a Ph.D. student at CSU and served as a co-lead author on the paper with postdoctoral researcher Zhen Zhang. Quinn said he and Zhang led work around the creation and testing of the material.
“We developed a sample P3HB glue stick and were able to use it with a commercially available glue gun to test its application in sealing cardboard boxes and other properties on steel plates,” Quinn said. “I knew the data supported it being stronger than other options, but I was shocked that we were able to show that it far out-performs typical hot-melt options – holding up to 20 pounds in place compared to the 15 pounds an existing adhesive could not manage.”
Chen said P3HB is biodegradable under a variety of instances, including managed and unmanaged environments. That means it will biodegrade naturally in landfills just as well as salty ocean water or soils, for example. That expands the range of possible options for dealing with the material at the end of its life cycle. The P3HB adhesive can also be recovered, reprocessed and reused.
The CSU team will now start work on ways to commercialize the polymer for broad use.
“We are working on two different approaches aiming for mass production, including ways to lower the overall cost and environmental impacts,” Chen said. “The analysis performed by the NREL team has identified key areas where we could make improvements, and we will continue to work with the BOTTLE Consortium on those scaling efforts.”
The role of political partisanship and moral beliefs in leadership selection
Society for Personality and Social Psychology
New research forthcoming in Social Psychological and Personality Science illuminates why liberals and conservatives often support different types of leaders. The study shows that these preferences stem from differences in moral priorities rather than mere partisan bias.
"This research helps explain why people across the political spectrum often support such different types of leaders," explains lead researcher Harrison Miller, of Florida State University. "Rather than simply attributing these differences to political bias, our findings suggest these preferences are rooted in fundamental moral values."
The research found that conservatives tend to favor dominant leaders who employ assertiveness and formal authority, while liberals prefer prestigious leaders who lead through knowledge and earned respect. These preferences closely align with each group's core moral beliefs.
"Conservatives tend to prioritize group loyalty and respect for authority, which aligns with dominant leadership styles. Liberals typically emphasize fairness and care for vulnerable populations, which aligns with prestige-based leadership styles," says Miller.
"Understanding these underlying moral motivations can help reduce political polarization by showing how different leadership preferences emerge from sincere moral convictions rather than mere partisan bias."
The findings provide new insight into recent global political trends. "Recent years have seen the rise of more assertive, dominance-oriented political leaders globally," notes Miller. "Our research helps explain why such leaders often receive strong support from politically conservative voters - not necessarily because these voters are inherently authoritarian, but because such leaders appear to embody moral values around group loyalty and traditional authority that conservatives prioritize."
The researchers emphasize that their findings should not be oversimplified. "This research should not be used to suggest that either leadership style or set of moral priorities is superior," Miller cautions. "Both dominant and prestige-based leadership styles can be effective in different contexts. Additionally, while we found general patterns in moral preferences between liberals and conservatives, individual variation exists within both groups."
This work bridges previously separate theories about moral foundations and leadership styles, offering a new framework for understanding political behavior. "It's important to emphasize that our research reveals the complexity of leadership preferences rather than reducing them to simple political divisions," concludes Miller. "Understanding the moral beliefs that may underly leadership support could help bridge political divides by fostering mutual understanding of different viewpoints."
This natural moral sense was perverted, Kropotkin says, by the superstitions surrounding law, religion and authority, deliberately cultivated by conquerors, ...
Fresh, direct evidence for tiny drops of quark-gluon plasma
Particles of light emitted from collisions of deuterons with gold ions provide direct evidence that energetic jets get 'stuck' — a key signature of quark-gluon plasma
DOE/Brookhaven National Laboratory
image:
Stony Brook University physicists Gabor David and Axel Drees sketch out how a signal of jet energy loss in deuteron-gold collisions at the Relativistic Heavy Ion Collider (RHIC) supports the case that these collisions create small specks of quark-gluon plasma, a form of matter that permeated the early universe.
Credit: Kevin Coughlin/Brookhaven National Laboratory
UPTON, N.Y. — A new analysis of data from the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) reveals fresh evidence that collisions of even very small nuclei with large ones might create tiny specks of a quark-gluon plasma (QGP). Scientists believe such a substance of free quarks and gluons, the building blocks of protons and neutrons, permeated the universe a fraction of a second after the Big Bang. RHIC’s energetic smashups of gold ions — the nuclei of gold atoms that have been stripped of their electrons — routinely create a QGP by “melting” these nuclear building blocks so scientists can study the QGP’s properties.
Physicists originally thought that collisions of smaller ions with large ones wouldn’t create a QGP because the small ion wouldn’t deposit enough energy to melt the large ion’s protons and neutrons. But evidence from PHENIX has long suggested that these small collision systems generate particle flow patterns that are consistent with the existence of tiny specks of the primordial soup, the QGP. The new findings, just published in Physical Review Letters, bolster the case for these tiny droplets of the QGP. The paper provides the first direct evidence that energetic particles generated in RHIC’s small collision systems sometimes lose energy and slow down significantly on the way out.
“We found, for the first time in a small collision system, the suppression of energetic particles, which is one of two main pieces of evidence for the QGP,” said PHENIX Collaboration Spokesperson Yasuyuki Akiba, a physicist at Japan’s RIKEN Nishina Center for Accelerator-Based Science and Experiment Group Leader at the RIKEN-BNL Research Center (RBRC) at Brookhaven Lab.
Jet quenching as a sign of QGP
Looking for the suppression of high-energy jets of particles, or jet “quenching,” has been a key goal from the earliest days at RHIC, a DOE Office of Science user facility for nuclear physics research that began operating at Brookhaven Lab in 2000. Jets are created when a quark or gluon within a proton or neutron in one of RHIC’s ion beams collides intensely with a quark or gluon in the nuclear particles that make up the beam traveling in the opposite direction. These strong interactions can kick single quarks or gluons free from the colliding nuclear building blocks with tremendous amounts of energy, which quickly transforms the energetic particles into cascades, or jets, of other particles.
If the collision doesn’t melt the nuclear matter into a soup of free quarks and gluons — the QGP — then these energetic jets of particles, or their decay products, sail out freely to be counted by RHIC’s detectors. But if the collisions do form a QGP, the kicked-free quark or gluon, despite its energy, gets caught up in interactions with the quarks and gluons that make up the plasma.
“Those interactions lead to energy loss,” explained Gabor David, a PHENIX physicist from Stony Brook University (SBU) who was one of the leaders of the new analysis.
“You can think about it like the difference between running through air and running through water,” he said. The QGP is like the water; it slows the particles down. As a result, jets reach the detector with only a fraction of their original energy.
To look for this suppression, the physicists first must estimate the number of energetic particles that would be expected from the gold-gold smashups by mathematically scaling up from simple proton-proton collisions to the number of protons and neutrons involved in collisions of heavier ions such as gold. The calculated values indirectly indicate whether the collision happens dead-center between the two gold ions or if it’s a glancing collision where the ions sideswipe one another at the edges. Central collisions are expected to create more jets than peripheral ones. But they’re also more likely to generate bigger QGP and therefore higher jet suppression.
This method has worked beautifully for the gold-gold smashups.
“We expected we should see 1,000 times the number of energetic particles, or jets, in the most central gold-gold collisions compared to proton-proton collisions,” Akiba said. “But we saw only about 200 times the proton-proton level, one-fifth the expected number. That’s a factor of five suppression.”
This jet suppression is a clear sign that the gold-gold collisions are generating the QGP. It’s also consistent with another key signature of the QGP formation in these collisions — namely, characteristic patterns of particle flow caused by hydrodynamic properties of the “perfect liquid” plasma.
When PHENIX scientists observed similar hydrodynamic flow patterns in small collision systems, hinting that there might be tiny drops of the QGP, they set out to search for jet suppression in those events as well. The results were a surprise: While the most central collisions of particles such as deuterons — one proton and one neutron — with gold ions exhibited signs of jet suppression, more peripheral collisions seemed to show an increase in energetic jets.
“There was no explanation for why this should happen — absolutely none,” David said.
Turning to direct photons
As it turns out, the surprising increase was an artifact of the indirect way the physicists had determined the centrality of the collisions. They discovered this by trying an alternate and more direct approach, as described in the new paper. Instead of using calculations based on a geometric model to estimate the number of nuclear particles — protons and neutrons — participating in the collisions, they used a direct measurement of those interactions by counting so-called “direct” photons.
This is possible because just as a RHIC collision can kick an energetic quark or gluon free, that interaction can also produce a high energy photon, or particle of light. These direct photons are produced in the collision right along with and in amounts proportional to the kicked-free quarks and gluons.
So, by counting the direct photons that strike their detector, the PHENIX scientists could directly measure the centrality of the collisions and know exactly how many energetic quarks or gluons were kicked free — that is, how many jets to expect.
“The more central the collision is, the more interactions there can be between the quarks and gluons of a small colliding deuteron with the quarks and gluons in the protons and neutrons of a gold ion,” explained Axel Drees of SBU, another leader of the analysis. “So, central smashups produce more direct photons and should produce more energetic jet particles than glancing collisions do.”
But unlike the quarks and gluons, the photons don’t interact with the QGP.
“If photons are created, they escape the QGP completely without any energy loss,” Drees said.
So, if there’s no QGP, the photons and energetic particles should be detected in proportionate amounts. But if in central collisions the number of energetic jet particles detected is significantly lower than the number of direct photons of the same energy, that could be a sign that a QGP is present, quenching the jets.
Niveditha Ramasubramanian, who was a graduate student advised by David at the time, undertook the challenging task of teasing out the direct photon signals from PHENIX’s deuteron-gold collision data. When her analysis was complete, the earlier, unexplained increase in jets emerging from peripheral collisions completely disappeared. But there was still a strong signal of suppression in the most central collisions.
“The initial motivation to do this complex analysis was only to better understand the strange increase in energetic jets in peripheral collisions, which we did,” said Ramasubramanian, a co-author on the paper who earned her Ph.D. — and a Thesis Award at the 2022 RHIC & AGS Users Meeting — for her contributions to this result. Now a staff scientist at the French National Centre for Scientific Research, she added, “The suppression that we observed in the most central collisions was entirely unexpected.”
“When we use the direct photons as a precise, accurate measure of the collision centrality, we can see the suppression [in central collisions] unambiguously,” Akiba said.
David noted that, “The new method relies solely on observable quantities, avoiding the use of theoretical models.”
The next step will be to apply the same method to other small collision systems.
“Ongoing analyses of PHENIX’s proton-gold and helium-3-gold data with the same technique will help to further clarify the origins of this suppression to confirm our current understanding or rule it out by competing explanations,” Drees said.
This research was funded by the DOE Office of Science (NP), the National Science Foundation, and a range of U.S. and international universities and organizations listed in the scientific paper. The PHENIX experiment collected data at RHIC from 2000 until 2016 and, as this paper indicates, analysis of its data is ongoing.
Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest 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, visit science.energy.gov.
PHENIX Collaboration Spokesperson Yasuyuki Akiba at the PHENIX detector, which collected data at the Relativistic Heavy Ion Collider (RHIC) from 2000 to 2016. A new analysis of PHENIX data provides fresh evidence that collisions of small particles with large nuclei create small specks of quark-gluon plasma.
Credit
Brookhaven National Laboratory
A penchant for photons and neutral pions: PHENIX is particularly good at detecting photons (wavy lines, γ). To detect jets, PHENIX measures the photons that neutral pions (π0) — often the leading particles that make up jets — decay into. Distinguishing between direct photons — those that come from the interaction of quarks and gluons in the collision — and decay photons, like those from the decay of a neutral pion or other particles in a jet, is a complicated, but well-established and proven procedure and was essential to the new PHENIX result. The image shows the difference between an energetic jet emerging from a proton-proton (p-p) collision, where no quark-gluon plasma (QGP) forms, and a jet that gets "quenched" — or loses energy — in a collision of a deuteron (d) with a gold (Au) nucleus. Note that direct photons (lower γ) emerge unaffected from each collision. The combination of equal-energy direct photons with jet-energy loss is a clear sign that QGP is forming in central deuteron-gold collisions.
Disentangling Centrality Bias and Final-State Effects in the Production of High-𝑝𝑇 Neutral Pions Using Direct Photon in 𝑑+Au Collisions at √𝑠𝑁𝑁=200 GeV
Article Publication Date
15-Jan-2025
SCI-FI-TEK-70YRS IN THE MAKING
UT secures $20 million DOE grant to develop critical nuclear fusion materials
University of Tennessee at Knoxville
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Professor Steven Zinkle, UT-ORNL Governor’s Chair for Nuclear Materials, talks with Munireach Nannory, first-year masters student, Civil and Structural Engineering, while preparing to test materials samples using a 3MV tandem accelerator with multiple beamlines and stations in the Ion Beam Materials Laboratory (IBML) inside Senter Hall.
The University of Tennessee, Knoxville’s Tickle College of Engineering has been awarded a $20 million grant from the U.S. Department of Energy for a groundbreaking project led by UT-Oak Ridge National Laboratory Governor’s Chair for Nuclear Materials Steve Zinkle. The project, known as the Integrated Materials Program to Accelerate Chamber Technologies, or IMPACT, aims to revolutionize the design and manufacturing of high-performance materials for fusion energy systems.
“We are excited to embark on this ambitious program,” Zinkle said. “Our assembled multidisciplinary team includes experts with a demonstrated track record of using science-based methods to rapidly design, fabricate and deploy advanced structural materials.”
One of the biggest challenges in making fusion energy commercially viable is the lack of nuclear-code-qualified high-temperature structural materials that can be used in fusion reactors. IMPACT aims to create a process and database for the first-ever American Society of Mechanical Engineers Boiler and Pressure Vessel code qualification for a fusion material and to demonstrate how these new materials can more quickly move from code qualification to engineering application.
UT has one of the best nuclear engineering programs in the country, including a new minor that launched in fall 2024. The IMPACT team led by Zinkle includes three other Tickle College of Engineering faculty members: Eric Lass, an assistant professor in the Department of Materials Science and Engineering; Bradley Jared, an associate professor in the Department of Mechanical, Aerospace, and Biomedical Engineering; and Khalid Hattar, an associate professor in the Department of Nuclear Engineering.
The DOE launched the FIRE Collaboratives initiative last year to establish collaborative networks that bridge the gap between fusion research and industry.
FIRE Collaboratives consist of teams from government facilities, academia and industry that come together to address technical challenges on the road to commercial fusion development. Through the FIRE Collaboratives, the DOE hopes to accelerate the transition of scientific discoveries into commercial fusion applications.
The other institutions involved in the project are Oak Ridge National Laboratory; Stony Brook University; the University of Michigan; Northwestern University; Massachusetts Institute of Technology; the University of California, Santa Barbara; Idaho National Laboratory; the University of Miami; and the University of California, Los Angeles.
US Department of Energy announces selectees for $107 million fusioninnovation research engine collaboratives, and progress in milestone program inspired by NASA
New awards from DOE will support acceleration of commercial fusion energy toward viability
DOE/US Department of Energy
WASHINGTON, D.C. — The U.S. Department of Energy (DOE) today announced $107 million in funding for six projects in the Fusion Innovative Research Engine (FIRE) Collaboratives, and that several privately funded fusion companies have completed early critical-path science and technology (S&T) milestones in the Milestone-Based Fusion Development Program (“the Milestone Program”). Both programs, administered by DOE’s Fusion Energy Sciences (FES) program in the Office of Science, are cornerstones of DOE’s fusion strategyto accelerate the viability of commercial fusion energy.
“The launch of the DOE Milestone Program and FIRE Collaboratives are critical steps in accelerating progress toward the U.S. Bold Decadal Vision for Commercial Fusion Energy,” said Deputy Secretary of Energy David Turk. “As the world races to make fusion a viable source of energy for industry and consumers, these programs signal that the U.S. intends to be the first to commercialize fusion energy through strong partnerships among our National Laboratories, universities, and the private sector to realize industry-led designs for fusion pilot plants.”
FIRE Collaboratives Project Selections
The FIRE Collaboratives are aimed at creating a fusion energy S&T innovation ecosystem by forming virtual, centrally managed teams called “Collaboratives” that have a collective goal of bridging FES’s basic science research programs with the needs of the growing fusion industry, including the activities supported under the Milestone Program.
This initiative represents a significant step forward in FES’s commitment to advancing fusion energy research and development, and aims to create new economic opportunities, maintain US leadership in fusion, bolster US-based manufacturing and supply chains, and enable the development of technologies crucial for national security, energy security, and defense.
FES is pleased to announce the first awards for the FIRE Collaboratives that support materials and technologies required by a diverse set of fusion concepts. They include developing nuclear blanket testing capabilities at Idaho National Laboratory, materials development at the University of Tennessee – Knoxville, materials testing and advanced simulation capabilities at the Massachusetts Institute of Technology, target injector technology for inertial fusion energy concepts, and fusion fuel-cycle testing capabilities at Savannah River National Laboratory.
Total anticipated funding for FIRE collaboratives is $180 million for projects lasting up to four years in duration. Additional awards drawing from the same pool of proposals may be made in the future. This is contingent on the availability of funds appropriated by Congress.
Selection for award negotiations is not a commitment by DOE to issue an award or provide funding. Before funding is issued, DOE and the applicants will undergo a negotiation process, and DOE may cancel negotiations and rescind the selection for any reason during that time.
Progress in the Milestone Program
The Milestone Program is modeled in part after the NASA Commercial Orbital Transportation Services (COTS) program. With relatively modest federal investments, the COTS program enabled private companies to meet early technical milestones on the way to building today’s commercial space-launch industry.
Analogous to the earlier NASA COTS program, privately funded fusion companies in the DOE Milestone Program pursue both S&T and business/commercialization milestones (mutually negotiated with DOE). They receive federal payments after DOE verifies completion of each milestone through independent, expert review. The private company provides greater than 50% (in many cases much greater than 50%) of the cost to meet milestones. The company benefits both through the non-dilutive capital it receives from the government as well as through DOE’s validation of milestone completion, which are both helpful for subsequent private fundraising.
Thus, the Milestone Program acts as a catalyst, where strategic federal investments are significantly amplified with follow-on private funding. To date, Milestone awardees have collectively raised over $350 million of new private funding since their selection into the program was announced in May 2023, compared to the $46 million of federal funding initially committed for negotiated milestones. The benefit to the U.S. public is the de-risking of multiple fusion-development paths that have both been peer-reviewed to be technically credible and are well aligned with commercial factors and needs.
Specifically, the 8 awardees of the present DOE Milestone Program are working to resolve critical-path S&T gaps, in partnership with national laboratories and universities, toward realizing preliminary engineering designs for their fusion pilot plants (FPPs). The most aggressive and well-funded of the awardees are aiming for successful FPP preliminary-design reviews by the late 2020s to meet the ambitious and aspirational timeline of realizing an operating FPP by the mid-2030s.
S&T milestones that have been met by companies thus far include the following:
Whole-device modeling of simple mirror equilibria to enable scientific energy gains of at least 5 for the tandem-mirror approach to fusion energy (Realta Fusion)
Down selection to a family of optimized stellarator equilibria taking into account multiple factors of plasma confinement, stability, and stellarator components and subsystems (Thea Energy)
Engineering design, prototyping, and operation of a single, high-temperature-superconducting magnet coil that is the building block of Thea Energy’s approach to generating 3-dimensional, optimized stellarator fields using only planar coils (Thea Energy).
Quantitative metrics were required to be met for these milestones. The specific metrics are typically protected information of the companies. The other Milestone awardees are Commonwealth Fusion Systems, Tokamak Energy, Type One Energy, Xcimer Energy, and Zap Energy, all of whom are working on their early S&T milestones as well.
All 8 awardees are presently working toward presenting pre-conceptual designs and technology roadmaps of their FPP concepts within the first 18 months of the Milestone program—roughly late 2025 (18 months into the Milestone Program). If they successfully meet these milestones, they will proceed into the next phase of the Milestone Program, where all the awardees are planning to build and operate major next-step integrated experiments and/or demonstrate some of the critical underlying technologies for their FPPs. Continued progress in the Milestone program is contingent on Congressional appropriations, successful negotiation of future milestones, and successful progress in the program.
The DOE Milestone-Based Fusion Development Program was first authorized in the Energy Act of 2020 and received its first funding appropriation in fiscal year 2022. The program was announced in September 2022 and, following a rigorous merit-review process, 8 selectees were announced in May 2023. Initially, $46 million has been obligated for the first 18 months of the program. The program is authorized for a total of $415 million through fiscal year 2027 in the CHIPS and Science Act of 2022.
State-of-the-art fusion simulation leads three scientists to the 2024 Kaul Foundation Prize
Prize Their simulation is one of many critical insights that have come from decades of work on a computer code known as XGC
DOE/Princeton Plasma Physics Laboratory
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The winners of the 2024 Kaul Foundation Prize for Excellence in Plasma Physics Research and Technology Development: PPPL’s Seung-Hoe Ku, Choongseok (CS) Chang, and Robert Hager.
Credit: Michael Livingston / PPPL Communications Department
Three scientists were awarded the 2024 Kaul Foundation Prize for Excellence in Plasma Physics Research and Technology Development based on their decades of groundbreaking research about how plasma behaves in fusion reactors.
Recently, the scientists – in collaboration with researchers from the Massachusetts Institute of Technology (MIT) and other collaborators working on the DIII-D fusion device at General Atomics – determined that these simulations closely matched experiments in the DIII-D. The research showed that the turbulence doubles the exhaust layer width in conditions similar to what would be found in a commercial-scale reactor such as ITER. This is an important experimental validation that XGC can describe the relevant underlying physics, helping support XGC predictions that ITER could have a much broader exhaust footprint than what has been predicted by present tokamak data.
This simulation code has been critical for a great deal of research that has advanced fusion science. The code simulates the whole volume of a tokamak plasma, especially the edge region of the magnetically confined plasma that includes the area where magnetic field lines cross, which is known as the X-point. This area is particularly important to study because of its reduced confining magnetic field strength, which can allow plasma particles to escape confinement. XGC is widely considered one of the best such codes available and is used by researchers worldwide on some of the planet’s most powerful computers.
“This work has brought great honor to the Lab,” said PPPL Director Steve Cowley when he presented the award at PPPL’s annual State of the Lab address. “This high-performance computing exascale project code, developed at our Lab, is also being honored by the U.S. Secretary of Energy with the prestigious Secretary’s Honor Award as part of the broader exascale computing initiative.”
Using very powerful hardware, exascale computers can perform one quintillion (or a billion billion) calculations per second, which makes them faster than the most powerful supercomputers currently used.
Each recipient of the annual Kaul Foundation Prize receives $7,500 in recognition of their scientific achievement. The prize was established with funds from the late PPPL Director Ronald C. Davidson’s 1993 Award for Excellence in Science, Education and Physics. It honors outstanding contributions to research in plasma physics.
Notably, the 2024 winners used XGC to determine critical details about how ions and electrons escape the core plasma during fusion when the plasma is confined by magnetic fields inside a tokamak. Their highly sophisticated simulation is for ITER, the multinational fusion facility under construction in France. The simulation suggests that a key region of the ITER wall should not get as hot as once feared based on the experimental data from present-day tokamaks.
“We would like to thank the national and international XGC team members. For the divertor heat load research, credit goes to the ITER Organization collaborators led by Alberto Loarte and Richard Pitts; PPPL, DIII-D, Alcator C-Mod, National Spherical Torus Experiment and Lawrence Livermore National Laboratory participants in the 2016 DOE Office of Science national theory milestone activities that led to the discovery of the ion leakage and turbulent electron loss physics that are responsible for plasma exhaust. We also thank the joint PPPL/DIII-D research team led by Alessandro Bortolon for the XGC application on DIII-D edge plasma and Darin Ernst of MIT for collaborating with us to simulate his experiments in ITER-like conditions, which turned out to be ideal for validating the XGC simulations,” said Chang.
“We hope to see more experimental validations on other tokamaks. We also would like to thank the tremendous support from the DOE program managers, DOE computer centers and PPPL management, which made the research possible.”
Choongseok (CS) Chang
After graduating with a doctoral degree in physics from the University of Texas at Austin in 1979, Chang was a senior scientist at General Atomics in San Diego before holding a tenure position at the Korea Advanced Institute of Science & Technology (KAIST). He later moved back to the U.S. and worked at the Courant Institute of Mathematical Sciences at New York University (NYU) before ultimately landing at PPPL in 2011.
Chang’s long career in plasma physics has focused on solving key theoretical challenges to make fusion a reliable source of electricity. Chang has spent decades leading multidisciplinary teams of physicists, applied mathematicians and computer scientists — including those who use artificial intelligence — to lead the development of XGC and simulate the extremely complex environment inside fusion reactors.
“Plasma is not a single physics phenomenon. Several physics interact together. But that was a very difficult theory to develop,” said Chang. Additionally, the problem was multiscale, meaning it needed to be studied at multiple levels of detail.
“Fortunately, I had a hunch in the late 1990s that computers would become more and more powerful so we could solve these problems,” Chang said. He recruited “a few brilliant students” to work on this important task. Among them, Ku was the main workforce. At the time, creating models that considered multiple physics simultaneously was considered nearly impossible. But Chang and the talented team – especially Ku – persisted. Ultimately, the work developing the necessary computer codes that could realize his multiphysics vision would receive substantial funding from the DOE and recognition from major U.S. computer centers. The success of this work eventually led Chang to resign from his positions in Korea and at NYU to fully dedicate himself to the XGC project and scientific discovery at PPPL. More young and talented physicists joined the development team and raised the code to a higher capability level. Among them, Hager became another distinguished developer and physics researcher.
One of the most rewarding aspects for Chang is seeing his younger group members become successful computational physicists in their own right. His advice to young physicists is to think big. “Don’t be afraid to attack challenging and ambitious scientific problems,” he said.
Seung-Hoe Ku
Ku has been a research physicist at the Lab since 2011, following Chang’s move. He received his doctoral degree in physics from KAIST in 2004.
Ku has been deeply involved in the research and development of the XGC code for decades, starting from when he was a graduate student at KAIST. Ku was effectively the sole person writing an initial version of what would one day become the backbone of XGC while he was still a graduate student.
“This has been a lifelong pursuit,” Ku said. He has seen the code through many iterations, moving it from a two-dimensional code into three dimensions and adding code to include turbulence, for example.
“When I extended it to 3D, a few people came on board to help with code performance,” Ku said. Now, many people around the world are working on XGC, with Ku and Hager focusing on managing the core of the code.
Ku has been interested in physics since middle school. In high school, he also developed an interest in coding. With some friends, Ku wrote what he describes as a precursor to the popular video game Angry Birds. “You throw the ball, and then it calculates the trajectory,” Ku said. “At the time, it was just for fun. But I think that’s my first physics simulation of particles.”
Ku would like to thank his wife, Haehyun Nam, for her patience.
Robert Hager
Hager received a doctoral degree in plasma physics jointly from the Technical University of Munich and the Max Planck Institute for Plasma Physics in 2011. The following year, he came to PPPL as a postdoctoral researcher. Hager has been working with Chang and Ku on XGC ever since. He became a core developer and is now a research physicist at the Lab.
“Winning the Kaul Prize is confirmation that what we’ve been doing all those years actually makes sense and produces good results,” Hager said. People sometimes question why he would work so hard on a code that is so complex it can only run using the world’s most powerful computers. “Now, finally, I think more people are seeing our results and realizing we can reproduce what people are seeing in experiments and get better insights,” Hager said.
In addition to being one of the main authors and managers of XGC, Hager is also responsible for training and supporting XGC users worldwide.
Hager says the field was definitely the right choice for him. “As a scientist, you sometimes have long stretches where nothing seems to work. But when you find a solution, you understand something new, and that is so rewarding. I also like the technical aspect, tinkering with computer tools.”
Like many in the field, Hager was initially drawn to plasma physics because of the environmental aspect of clean energy from fusion. However, there were also personal factors: His position at Max Planck brought him closer to his girlfriend, who he would later marry. “I would like to thank my wife, Sofia, my Ph.D. supervisor Klaus Hallatschek and everyone who helped make XGC what it is today.”
