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      in Energy

      Finding community in high-energy-density physics

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      Skylar Dannhoff knew one thing: She did not want to be working alone.

      As an undergraduate at Case Western Reserve University, she had committed to a senior project that often felt like solitary lab work, a feeling heightened by the pandemic. Though it was an enriching experience, she was determined to find a graduate school environment that would foster community, one “with lots of people, lots of collaboration; where it’s impossible to work until 3 a.m. without anyone noticing.” A unique group at the Plasma Science and Fusion Center (PSFC) looked promising: the High-Energy-Density Physics (HEDP) division, a lead partner in the National Nuclear Security Administration’s Center for Excellence at MIT.

      “It was a shot in the dark, just more of a whim than anything,” she says of her request to join HEDP on her application to MIT’s Department of Physics. “And then, somehow, they reached out to me. I told them I’m willing to learn about plasma. I didn’t know anything about it.”

      What she did know was that the HEDP group collaborates with other U.S. laboratories on an approach to creating fusion energy known as inertial confinement fusion (ICF). One version of the technique, known as direct-drive ICF, aims multiple laser beams symmetrically onto a spherical capsule filled with nuclear fuel. The other, indirect-drive ICF, instead aims multiple lasers beams into a gold cylindrical cavity called a hohlraum, within which the spherical fuel capsule is positioned. The laser beams are configured to hit the inner hohlraum wall, generating a “bath” of X-rays, which in turn compress the fuel capsule.

      Imploding the capsule generates intense fusion energy within a tiny fraction of a second (an order of tens of picoseconds). In August 2021, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) used this method to produce an historic fusion yield of 1.3 megajoules, putting researchers within reach of “ignition,” the point where the self-sustained fusion burn spreads into the surrounding fuel, leading to a high fusion-energy gain.  

      Joining the group just a month before this long-sought success, Dannhoff was impressed more with the response of her new teammates and the ICF community than with the scientific milestone. “I got a better appreciation for people who had spent their entire careers working on this project, just chugging along doing their best, ignoring the naysayers. I was excited for the people.”

      Dannhoff is now working toward extending the success of NIF and other ICF experiments, like the OMEGA laser at the University of Rochester’s Laboratory for Laser Energetics. Under the supervision of Senior Research Scientist Chikang Li, she is studying what happens to the flow of plasma within the hohlraum cavity during indirect ICF experiments, particularly for hohlraums with inner-wall aerogel foam linings. Experiments, over the last decade, have shown just how excruciatingly precise the symmetry in ICF targets must be. The more symmetric the X-ray drive, the more effective the implosion, and it is possible that these foam linings will improve the X-ray symmetry and drive efficiency.

      Dannhoff is specifically interested in studying the behavior of silicon and tantalum-based foam liners. She is as concerned with the challenges of the people at General Atomics (GA) and LLNL who are creating these targets as she is with the scientific outcome.

      “I just had a meeting with GA yesterday,” she notes. “And it’s a really tricky process. It’s kind of pushing the boundaries of what is doable at the moment. I got a much better sense of how demanding this project is for them, how much we’re asking of them.”

      What excites Dannhoff is the teamwork she observes, both at MIT and between ICF institutions around the United States. With roughly 10 graduate students and postdocs down the hall, each with an assigned lead role in lab management, she knows she can consult an expert on almost any question. And collaborators across the country are just an email away. “Any information that people can give you, they will give you, and usually very freely,” she notes. “Everyone just wants to see this work.”

      That Dannhoff is a natural team player is also evidenced in her hobbies. A hockey goalie, she prioritizes playing with MIT’s intramural teams, “because goalies are a little hard to come by. I just play with whoever needs a goalie on that night, and it’s a lot of fun.”

      She is also a member of the radio community, a fellowship she first embraced at Case Western — a moment she describes as a turning point in her life. “I literally don’t know who I would be today if I hadn’t figured out radio is something I’m interested in,” she admits. The MIT Radio Society provided the perfect landing pad for her arrival in Cambridge, full of the kinds of supportive, interesting, knowledgeable students she had befriended as an undergraduate. She credits radio with helping her realize that she could make her greatest contributions to science by focusing on engineering.

      Danhoff gets philosophical as she marvels at the invisible waves that surround us.

      “Not just radio waves: every wave,” she asserts. “The voice is the everywhere. Music, signal, space phenomena: it’s always around. And all we have to do is make the right little device and have the right circuit elements put in the right order to unmix and mix the signals and amplify them. And bada-bing, bada-boom, we’re talking with the universe.”

      “Maybe that epitomizes physics to me,” she adds. “We’re trying to listen to the universe, and it’s talking to us. We just have to come up with the right tools and hear what it’s trying to say.” More

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      in Energy

      MIT students contribute to success of historic fusion experiment

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      For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition in a laboratory, a grand challenge of the 21st century. The High-Energy-Density Physics (HEDP) group at MIT’s Plasma Science and Fusion Center has focused on an approach called inertial confinement fusion (ICF), which uses lasers to implode a pellet of fuel in a quest for ignition. This group, including nine former and current MIT students, was crucial to an historic ICF ignition experiment performed in 2021; the results were published on the anniversary of that success.

      On Aug. 8, 2021, researchers at the National Ignition Facility (NIF), Lawrence Livermore National Laboratory (LLNL), used 192 laser beams to illuminate the inside of a tiny gold cylinder encapsulating a spherical capsule filled with deuterium-tritium fuel in their quest to produce significant fusion energy. Although researchers had followed this process many times before, using different parameters, this time the ensuing implosion produced an historic fusion yield of 1.37 megaJoules, as measured by a suite of neutron diagnostics. These included the MIT-developed and analyzed Magnetic Recoil Spectrometer (MRS). This result was published in Physical Review Letters on Aug. 8, the one-year anniversary of the ground-breaking development, unequivocally indicating that the first controlled fusion experiment reached ignition.

      Governed by the Lawson criterion, a plasma ignites when the internal fusion heating power is high enough to overcome the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop that very rapidly increases the plasma temperature. In the case of ICF, ignition is a state where the fusion plasma can initiate a “fuel burn propagation” into the surrounding dense and cold fuel, enabling the possibility of high fusion-energy gain.

      “This historic result certainly demonstrates that the ignition threshold is a real concept, with well-predicted theoretical calculations, and that a fusion plasma can be ignited in a laboratory” says HEDP Division Head Johan Frenje.

      The HEDP division has contributed to the success of the ignition program at the NIF for more than a decade by providing and using a dozen diagnostics, implemented by MIT PhD students and staff, which have been critical for assessing the performance of an implosion. The hundreds of co-authors on the paper attest to the collaborative effort that went into this milestone. MIT’s contributors included the only student co-authors.

      “The students are responsible for implementing and using a diagnostic to obtain data important to the ICF program at the NIF, says Frenje. “Being responsible for running a diagnostic at the NIF has allowed them to actively participate in the scientific dialog and thus get directly exposed to cutting-edge science.”

      Students involved from the MIT Department of Physics were Neel Kabadi, Graeme Sutcliffe, Tim Johnson, Jacob Pearcy, and Ben Reichelt; students from the Department of Nuclear Science and Engineering included Brandon Lahmann, Patrick Adrian, and Justin Kunimune.

      In addition, former student Alex Zylstra PhD ’15, now a physicist at LLNL, was the experimental lead of this record implosion experiment. More

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      in Energy

      High energy and hungry for the hardest problems

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      A high school track star and valedictorian, Anne White has always relished moving fast and clearing high hurdles. Since joining the Department of Nuclear Science and Engineering (NSE) in 2009 she has produced path-breaking fusion research, helped attract a more diverse cohort of students and scholars into the discipline, and, during a worldwide pandemic, assumed the role of department head as well as co-lead of an Institute-wide initiative to address climate change. For her exceptional leadership, innovation, and accomplishments in education and research, White was named the School of Engineering Distinguished Professor of Engineering in July 2020.

      But White declares little interest in recognition or promotions. “I don’t care about all that stuff,” she says. She’s in the race for much bigger stakes. “I want to find ways to save the world with nuclear,” she says.

      Tackling turbulence

      It was this goal that drew White to MIT. Her research, honed during graduate studies at the University of California at Los Angeles, involved developing a detailed understanding of conditions inside fusion devices, and resolving issues critical to realizing the vision of fusion energy — a carbon-free, nearly limitless source of power generated by 150-million-degree plasma.

      Harnessing this superheated, gaseous form of matter requires a special donut-shaped device called a tokamak, which contains the plasma within magnetic fields. When White entered fusion around the turn of the millennium, models of plasma behavior in tokamaks didn’t reliably match observed or experimental conditions. She was determined to change that picture, working with MIT’s state-of-the-art research tokamak, Alcator C-Mod.

      Play video

      Alcator C-Mod Tokamak Tour

      White believed solving the fusion puzzle meant getting a handle on plasma turbulence — the process by which charged atomic particles, breaking out of magnetic confinement, transport heat from the core to the cool edges of the tokamak. Although researchers knew that fusion energy depends on containing and controlling the heat of plasma reactions, White recalls that when she began grad school, “it was not widely accepted that turbulence was important, and that it was central to heat transport. She “felt it was critical to compare experimental measurements to first principles physics models, so we could demonstrate the significance of turbulence and give tokamak models better predictive ability.”

      In a series of groundbreaking studies, White’s team created the tools for measuring turbulence in different conditions, and developed computational models that could account for variations in turbulence, all validated by experiments. She was one of the first fusion scientists both to perform experiments and conduct simulations. “We lived in the domain between these two worlds,” she says.

      White’s turbulence models opened up approaches for managing turbulence and maximizing tokamak performance, paving the way for net-energy fusion energy devices, including ITER, the world’s largest fusion experiment, and SPARC, a compact, high-magnetic-field tokamak, a collaboration between MIT’s Plasma Science and Fusion Center and Commonwealth Fusion Systems.

      Laser-focused on turbulence

      Growing up in the desert city of Yuma, Arizona, White spent her free time outdoors, hiking and camping. “I was always in the space of protecting the environment,” she says. The daughter of two lawyers who taught her “to argue quickly and efficiently,” she excelled in math and physics in high school. Awarded a full ride at the University of Arizona, she was intent on a path in science, one where she could tackle problems like global warming, as it was known then. Physics seemed like the natural concentration for her.

      But there was unexpected pushback. The physics advisor believed her physics grades were lackluster. “I said, ‘Who cares what this guy thinks; I’ll take physics classes anyway,’” recalls White. Being tenacious and “thick skinned,” says White, turned out to be life-altering. “I took nuclear physics, which opened my eyes to fission, which then set me off on a path of understanding nuclear power and advanced nuclear systems,” she says. Math classes introduced her to chaotic systems, and she decided she wanted to study turbulence. Then, at a Society of Physics Students meeting White says she attended for the free food, she learned about fusion.

      “I realized this was what I wanted to do,” says White. “I became totally laser focused on turbulence and tokamaks.”

      At UCLA, she began to develop instruments and methods for measuring and modeling plasma turbulence, working on three different fusion research reactors, and earning fellowships from the Department of Energy (DOE) during her graduate and post-graduate years in fusion energy science. At MIT, she received a DOE Early Career Award that enabled her to build a research team that she now considers her “legacy.”

      As she expanded her research portfolio, White was also intent on incorporating fusion into the NSE curriculum at the undergraduate and graduate level, and more broadly, on making NSE a destination for students concerned about climate change. In recognition of her efforts, she received the 2014 Junior Bose Teaching Award. She also helped design the EdX course, Nuclear Engineering: Science, Systems and Society, introducing thousands of online learners to the potential of the field. “I have to be in the classroom,” she says. “I have to be with students, interacting, and sharing knowledge and lines of inquiry with them.”

      But even as she deepened her engagement with teaching and with her fusion research, which was helping spur development of new fusion energy technologies, White could not resist leaping into a consequential new undertaking: chairing the department. “It sounds cheesy, but I did it for my kid,” she says. “I can be helpful working on fusion, but I thought, what if I can help more by enabling other people across all areas of nuclear? This department gave me so much, I wanted to give back.”

      Although the pandemic struck just months after she stepped into the role in 2019, White propelled the department toward a new strategic plan. “It captures all the urgency and passion of the faculty, and is attractive to new students, with more undergraduates enrolling and more graduate students applying,” she says. White sees the department advancing the broader goals of the field, “articulating why nuclear is fundamentally important across many dimensions for carbon-free electricity and generation.” This means getting students involved in advanced fission technologies such as nuclear batteries and small modular reactors, as well as giving them an education in fusion that will help catalyze a nascent energy industry.

      Restless for a challenge

      White feels she’s still growing into the leadership role. “I’m really enthusiastic and sometimes too intense for people, so I have to dial it back during challenging conversations,” she says. She recently completed a Harvard Business School course on leadership.

      As the recently named co-chair of MIT’s Climate Nucleus (along with Professor Noelle Selin), charged with overseeing MIT’s campus initiatives around climate change, White says she draws on a repertoire of skills that come naturally to her: listening carefully, building consensus, and seeing value in the diversity of opinion. She is optimistic about mobilizing the Institute around goals to lower MIT’s carbon footprint, “using the entire campus as a research lab,” she says.

      In the midst of this push, White continues to advance projects of concern to her, such as making nuclear physics education more accessible. She developed an in-class module involving a simple particle detector for measuring background radiation. “Any high school or university student could build this experiment in 10 minutes and see alpha particle clusters and muons,” she says.

      White is also planning to host “Rising Stars,” an international conference intended to help underrepresented groups break barriers to entry in the field of nuclear science and engineering. “Grand intellectual challenges like saving the world appeal to all genders and backgrounds,” she says.

      These projects, her departmental and institutional duties, and most recently a new job chairing DOE’s Fusion Energy Sciences Advisory Committee leave her precious little time for a life outside work. But she makes time for walks and backpacking with her husband and toddler son, and reading the latest books by female faculty colleagues, such as “The New Breed,” by Media Lab robotics researcher Kate Darling, and “When People Want Punishment,” by Lily Tsai, Ford Professor of Political Science. “There are so many things I don’t know and want to understand,” says White.

      Yet even at leisure, White doesn’t slow down. “It’s restlessness: I love to learn, and anytime someone says a problem is hard, or impossible, I want to tackle it,” she says. There’s no time off, she believes, when the goal is “solving climate change and amplifying the work of other people trying to solve it.” More

    • 88 Shares149 Views

      in Environment

      High-energy and hungry for the hardest problems

      by

      A high school track star and valedictorian, Anne White has always relished moving fast and clearing high hurdles. Since joining the Department of Nuclear Science and Engineering (NSE) in 2009 she has produced path-breaking fusion research, helped attract a more diverse cohort of students and scholars into the discipline, and, during a worldwide pandemic, assumed the role of department head as well as co-lead of an Institute-wide initiative to address climate change. For her exceptional leadership, innovation, and accomplishments in education and research, White was named the School of Engineering Distinguished Professor of Engineering in July 2020.

      But White declares little interest in recognition or promotions. “I don’t care about all that stuff,” she says. She’s in the race for much bigger stakes. “I want to find ways to save the world with nuclear,” she says.

      Tackling turbulence

      It was this goal that drew White to MIT. Her research, honed during graduate studies at the University of California at Los Angeles, involved developing a detailed understanding of conditions inside fusion devices, and resolving issues critical to realizing the vision of fusion energy — a carbon-free, nearly limitless source of power generated by 150-million-degree plasma.

      Harnessing this superheated, gaseous form of matter requires a special donut-shaped device called a tokamak, which contains the plasma within magnetic fields. When White entered fusion around the turn of the millennium, models of plasma behavior in tokamaks didn’t reliably match observed or experimental conditions. She was determined to change that picture, working with MIT’s state-of-the-art research tokamak, Alcator C-Mod.

      Play video

      Alcator C-Mod Tokamak Tour

      White believed solving the fusion puzzle meant getting a handle on plasma turbulence — the process by which charged atomic particles, breaking out of magnetic confinement, transport heat from the core to the cool edges of the tokamak. Although researchers knew that fusion energy depends on containing and controlling the heat of plasma reactions, White recalls that when she began grad school, “it was not widely accepted that turbulence was important, and that it was central to heat transport. She “felt it was critical to compare experimental measurements to first principles physics models, so we could demonstrate the significance of turbulence and give tokamak models better predictive ability.”

      In a series of groundbreaking studies, White’s team created the tools for measuring turbulence in different conditions, and developed computational models that could account for variations in turbulence, all validated by experiments. She was one of the first fusion scientists both to perform experiments and conduct simulations. “We lived in the domain between these two worlds,” she says.

      White’s turbulence models opened up approaches for managing turbulence and maximizing tokamak performance, paving the way for net-energy fusion energy devices, including ITER, the world’s largest fusion experiment, and SPARC, a compact, high-magnetic-field tokamak, a collaboration between MIT’s Plasma Science and Fusion Center and Commonwealth Fusion Systems.

      Laser-focused on turbulence

      Growing up in the desert city of Yuma, Arizona, White spent her free time outdoors, hiking and camping. “I was always in the space of protecting the environment,” she says. The daughter of two lawyers who taught her “to argue quickly and efficiently,” she excelled in math and physics in high school. Awarded a full ride at the University of Arizona, she was intent on a path in science, one where she could tackle problems like global warming, as it was known then. Physics seemed like the natural concentration for her.

      But there was unexpected pushback. The physics advisor believed her physics grades were lackluster. “I said, ‘Who cares what this guy thinks; I’ll take physics classes anyway,’” recalls White. Being tenacious and “thick skinned,” says White, turned out to be life-altering. “I took nuclear physics, which opened my eyes to fission, which then set me off on a path of understanding nuclear power and advanced nuclear systems,” she says. Math classes introduced her to chaotic systems, and she decided she wanted to study turbulence. Then, at a Society of Physics Students meeting White says she attended for the free food, she learned about fusion.

      “I realized this was what I wanted to do,” says White. “I became totally laser focused on turbulence and tokamaks.”

      At UCLA, she began to develop instruments and methods for measuring and modeling plasma turbulence, working on three different fusion research reactors, and earning fellowships from the Department of Energy (DOE) during her graduate and post-graduate years in fusion energy science. At MIT, she received a DOE Early Career Award that enabled her to build a research team that she now considers her “legacy.”

      As she expanded her research portfolio, White was also intent on incorporating fusion into the NSE curriculum at the undergraduate and graduate level, and more broadly, on making NSE a destination for students concerned about climate change. In recognition of her efforts, she received the 2014 Junior Bose Teaching Award. She also helped design the EdX course, Nuclear Engineering: Science, Systems and Society, introducing thousands of online learners to the potential of the field. “I have to be in the classroom,” she says. “I have to be with students, interacting, and sharing knowledge and lines of inquiry with them.”

      But even as she deepened her engagement with teaching and with her fusion research, which was helping spur development of new fusion energy technologies, White could not resist leaping into a consequential new undertaking: chairing the department. “It sounds cheesy, but I did it for my kid,” she says. “I can be helpful working on fusion, but I thought, what if I can help more by enabling other people across all areas of nuclear? This department gave me so much, I wanted to give back.”

      Although the pandemic struck just months after she stepped into the role in 2019, White propelled the department toward a new strategic plan. “It captures all the urgency and passion of the faculty, and is attractive to new students, with more undergraduates enrolling and more graduate students applying,” she says. White sees the department advancing the broader goals of the field, “articulating why nuclear is fundamentally important across many dimensions for carbon-free electricity and generation.” This means getting students involved in advanced fission technologies such as nuclear batteries and small modular reactors, as well as giving them an education in fusion that will help catalyze a nascent energy industry.

      Restless for a challenge

      White feels she’s still growing into the leadership role. “I’m really enthusiastic and sometimes too intense for people, so I have to dial it back during challenging conversations,” she says. She recently completed a Harvard Business School course on leadership.

      As the recently named co-chair of MIT’s Climate Nucleus (along with Professor Noelle Selin), charged with overseeing MIT’s campus initiatives around climate change, White says she draws on a repertoire of skills that come naturally to her: listening carefully, building consensus, and seeing value in the diversity of opinion. She is optimistic about mobilizing the Institute around goals to lower MIT’s carbon footprint, “using the entire campus as a research lab,” she says.

      In the midst of this push, White continues to advance projects of concern to her, such as making nuclear physics education more accessible. She developed an in-class module involving a simple particle detector for measuring background radiation. “Any high school or university student could build this experiment in 10 minutes and see alpha particle clusters and muons,” she says.

      White is also planning to host “Rising Stars,” an international conference intended to help underrepresented groups break barriers to entry in the field of nuclear science and engineering. “Grand intellectual challenges like saving the world appeal to all genders and backgrounds,” she says.

      These projects, her departmental and institutional duties, and most recently a new job chairing DOE’s Fusion Energy Sciences Advisory Committee leave her precious little time for a life outside work. But she makes time for walks and backpacking with her husband and toddler son, and reading the latest books by female faculty colleagues, such as “The New Breed,” by Media Lab robotics researcher Kate Darling, and “When People Want Punishment,” by Lily Tsai, Ford Professor of Political Science. “There are so many things I don’t know and want to understand,” says White.

      Yet even at leisure, White doesn’t slow down. “It’s restlessness: I love to learn, and anytime someone says a problem is hard, or impossible, I want to tackle it,” she says. There’s no time off, she believes, when the goal is “solving climate change and amplifying the work of other people trying to solve it.” More

    • 175 Shares179 Views

      in Energy

      Bridging careers in aerospace manufacturing and fusion energy, with a focus on intentional inclusion

      by

      “A big theme of my life has been focusing on intentional inclusion and how I can create environments where people can really bring their whole authentic selves to work,” says Joy Dunn ’08. As the vice president of operations at Commonwealth Fusion Systems, an MIT spinout working to achieve commercial fusion energy, Dunn looks for solutions to the world’s greatest climate challenges — while creating an open and equitable work environment where everyone can succeed.

      This theme has been cultivated throughout her professional and personal life, including as a Young Global Leader at the World Economic Forum and as a board member at Out for Undergrad, an organization that works with LGBTQ+ college students to help them achieve their personal and professional goals. Through her careers both in aerospace and energy, Dunn has striven to instill a sense of equity and inclusion from the inside out.

      Developing a love for space

      Dunn’s childhood was shaped by space. “I was really inspired as a kid to be an astronaut,” she says, “and for me that never stopped.” Dunn’s parents — both of whom had careers in the aerospace industry — encouraged her from an early age to pursue her interests, from building model rockets to visiting the National Air and Space Museum to attending space camp. A large inspiration for this passion arose when she received a signed photo from Sally Ride — the first American woman in space — that read, “To Joy, reach for the stars.”

      As her interests continued to grow in middle school, she and her mom looked to see what it would take to become an astronaut, asking questions such as “what are the common career paths?” and “what schools did astronauts typically go to?” They quickly found that MIT was at the top of that list, and by seventh grade, Dunn had set her sights on the Institute. 

      After years of hard work, Dunn entered MIT in fall 2004 with a major in aeronautical and astronautical engineering (AeroAstro). At MIT, she remained fully committed to her passion while also expanding into other activities such as varsity softball, the MIT Undergraduate Association, and the Alpha Chi Omega sorority.

      One of the highlights of Dunn’s college career was Unified Engineering, a year-long course required for all AeroAstro majors that provides a foundational knowledge of aerospace engineering — culminating in a team competition where students design and build remote-controlled planes to be pitted against each other. “My team actually got first place, which was very exciting,” she recalls. “And I honestly give a lot of that credit to our pilot. He did a very good job of not crashing!” In fact, that pilot was Warren Hoburg ’08, a former assistant professor in AeroAstro and current NASA astronaut training for a mission on the International Space Station.

      Pursuing her passion at SpaceX

      Dunn’s undergraduate experience culminated with an internship at the aerospace manufacturing company SpaceX in summer 2008. “It was by far my favorite internship of the ones that I had in college. I got to work on really hands-on projects and had the same amount of responsibility as a full-time employee,” she says.

      By the end of the internship, she was hired as a propulsion development engineer for the Dragon spacecraft, where she helped to build the thrusters for the first Dragon mission. Eventually, she transferred to the role of manufacturing engineer. “A lot of what I’ve done in my life is building things and looking for process improvements,” so it was a natural fit. From there, she rose through the ranks, eventually becoming the senior manager of spacecraft manufacturing engineering, where she oversaw all the manufacturing, test, and integration engineers working on Dragon. “It was pretty incredible to go from building thrusters to building the whole vehicle,” she says.

      During her tenure, Dunn also co-founded SpaceX’s Women’s Network and its LGBT affinity group, Out and Allied. “It was about providing spaces for employees to get together and provide a sense of community,” she says. Through these groups, she helped start mentorship and community outreach programs, as well as helped grow the pipeline of women in leadership roles for the company.

      In spite of all her successes at SpaceX, she couldn’t help but think about what came next. “I had been at SpaceX for almost a decade and had these thoughts of, ‘do I want to do another tour of duty or look at doing something else?’ The main criteria I set for myself was to do something that is equally or more world-changing than SpaceX.”

      A pivot to fusion

      It was at this time in 2018 that Dunn received an email from a former mentor asking if she had heard about a fusion energy startup called Commonwealth Fusion Systems (CFS) that worked with the MIT Plasma Science and Fusion Center. “I didn’t know much about fusion at all,” she says. “I had heard about it as a science project that was still many, many years away as a viable energy source.”

      After learning more about the technology and company, “I was just like, ‘holy cow, this has the potential to be even more world-changing than what SpaceX is doing.’” She adds, “I decided that I wanted to spend my time and brainpower focusing on cleaning up the planet instead of getting off it.”

      After connecting with CFS CEO Bob Mumgaard SM ’15, PhD ’15, Dunn joined the company and returned to Cambridge as the head of manufacturing. While moving from the aerospace industry to fusion energy was a large shift, she said her first project — building a fusion-relevant, high-temperature superconducting magnet capable of achieving 20 tesla — tied back into her life of being a builder who likes to get her hands on things.

      Over the course of two years, she oversaw the production and scaling of the magnet manufacturing process. When she first came in, the magnets were being constructed in a time-consuming and manual way. “One of the things I’m most proud of from this project is teaching MIT research scientists how to think like manufacturing engineers,” she says. “It was a great symbiotic relationship. The MIT folks taught us the physics and science behind the magnets, and we came in to figure out how to make them into a more manufacturable product.”

      In September 2021, CFS tested this high-temperature superconducting magnet and achieved its goal of 20 tesla. This was a pivotal moment for the company that brought it one step closer to achieving its goal of producing net-positive fusion power. Now, CFS has begun work on a new campus in Devens, Massachusetts, to house their manufacturing operations and SPARC fusion device. Dunn plays a pivotal role in this expansion as well. In March 2021, she was promoted to the head of operations, which expanded her responsibilities beyond managing manufacturing to include facilities, construction, safety, and quality. “It’s been incredible to watch the campus grow from a pile of dirt … into full buildings.”

      In addition to the groundbreaking work, Dunn highlights the culture of inclusiveness as something that makes CFS stand apart to her. “One of the main reasons that drew me to CFS was hearing from the company founders about their thoughts on diversity, equity, and inclusion, and how they wanted to make that a key focus for their company. That’s been so important in my career, and I’m really excited to see how much that’s valued at CFS.” The company has carried this out through programs such as Fusion Inclusion, an initiative that aims to build a strong and inclusive community from the inside out.

      Dunn stresses “the impact that fusion can have on our world and for addressing issues of environmental injustice through an equitable distribution of power and electricity.” Adding, “That’s a huge lever that we have. I’m excited to watch CFS grow and for us to make a really positive impact on the world in that way.”

      This article appears in the Spring 2022 issue of Energy Futures, the magazine of the MIT Energy Initiative. More

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      in Energy

      Fusion’s newest ambassador

      by

      When high school senior Tuba Balta emailed MIT Plasma Science and Fusion Center (PSFC) Director Dennis Whyte in February, she was not certain she would get a response. As part of her final semester at BASIS Charter School, in Washington, she had been searching unsuccessfully for someone to sponsor an internship in fusion energy, a topic that had recently begun to fascinate her because “it’s not figured out yet.” Time was running out if she was to include the internship as part of her senior project.

      “I never say ‘no’ to a student,” says Whyte, who felt she could provide a youthful perspective on communicating the science of fusion to the general public.

      Posters explaining the basics of fusion science were being considered for the walls of a PSFC lounge area, a space used to welcome visitors who might not know much about the center’s focus: What is fusion? What is plasma? What is magnetic confinement fusion? What is a tokamak?

      Why couldn’t Balta be tasked with coming up with text for these posters, written specifically to be understandable, even intriguing, to her peers?

      Meeting the team

      Although most of the internship would be virtual, Balta visited MIT to meet Whyte and others who would guide her progress. A tour of the center showed her the past and future of the PSFC, one lab area revealing on her left the remains of the decades-long Alcator C-Mod tokamak and on her right the testing area for new superconducting magnets crucial to SPARC, designed in collaboration with MIT spinoff Commonwealth Fusion Systems.

      With Whyte, graduate student Rachel Bielajew, and Outreach Coordinator Paul Rivenberg guiding her content and style, Balta focused on one of eight posters each week. Her school also required her to keep a weekly blog of her progress, detailing what she was learning in the process of creating the posters.

      Finding her voice

      Balta admits that she was not looking forward to this part of the school assignment. But she decided to have fun with it, adopting an enthusiastic and conversational tone, as if she were sitting with friends around a lunch table. Each week, she was able to work out what she was composing for her posters and her final project by trying it out on her friends in the blog.

      Her posts won praise from her schoolmates for their clarity, as when in Week 3 she explained the concept of turbulence as it relates to fusion research, sending her readers to their kitchen faucets to experiment with the pressure and velocity of running tap water.

      The voice she found through her blog served her well during her final presentation about fusion at a school expo for classmates, parents, and the general public.

      “Most people are intimidated by the topic, which they shouldn’t be,” says Balta. “And it just made me happy to help other people understand it.”

      Her favorite part of the internship? “Getting to talk to people whose papers I was reading and ask them questions. Because when it comes to fusion, you can’t just look it up on Google.”

      Awaiting her first year at the University of Chicago, Balta reflects on the team spirit she experienced in communicating with researchers at the PSFC.

      “I think that was one of my big takeaways,” she says, “that you have to work together. And you should, because you’re always going to be missing some piece of information; but there’s always going to be somebody else who has that piece, and we can all help each other out.” More

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      Evan Leppink: Seeking a way to better stabilize the fusion environment

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      “Fusion energy was always one of those kind-of sci-fi technologies that you read about,” says nuclear science and engineering PhD candidate Evan Leppink. He’s recalling the time before fusion became a part of his daily hands-on experience at MIT’s Plasma Science and Fusion Center, where he is studying a unique way to drive current in a tokamak plasma using radiofrequency (RF) waves. 

      Now, an award from the U.S. Department of Energy’s (DOE) Office of Science Graduate Student Research (SCGSR) Program will support his work with a 12-month residency at the DIII-D National Fusion Facility in San Diego, California.

      Like all tokamaks, DIII-D generates hot plasma inside a doughnut-shaped vacuum chamber wrapped with magnets. Because plasma will follow magnetic field lines, tokamaks are able to contain the turbulent plasma fuel as it gets hotter and denser, keeping it away from the edges of the chamber where it could damage the wall materials. A key part of the tokamak concept is that part of the magnetic field is created by electrical currents in the plasma itself, which helps to confine and stabilize the configuration. Researchers often launch high-power RF waves into tokamaks to drive that current.

      Leppink will be contributing to research, led by his MIT advisor Steve Wukitch, that pursues launching RF waves in DIII-D using a unique compact antenna placed on the tokamak center column. Typically, antennas are placed inside the tokamak on the outer edge of the doughnut, farthest from the central hole (or column), primarily because access and installation are easier there. This is known as the “low-field side,” because the magnetic field is lower there than at the central column, the “high-field side.” This MIT-led experiment, for the first time, will mount an antenna on the high-field side. There is some theoretical evidence that placing the wave launcher there could improve power penetration and current drive efficiency. And because the plasma environment is less harsh on this side, the antenna will survive longer, a factor important for any future power-producing tokamak.

      Leppink’s work on DIII-D focuses specifically on measuring the density of plasmas generated in the tokamak, for which he developed a “reflectometer.” This small antenna launches microwaves into the plasma, which reflect back to the antenna to be measured. The time that it takes for these microwaves to traverse the plasma provides information about the plasma density, allowing researchers to build up detailed density profiles, data critical for injecting RF power into the plasma.

      “Research shows that when we try to inject these waves into the plasma to drive the current, they can lose power as they travel through the edge region of the tokamak, and can even have problems entering the core of the plasma, where we would most like to direct them,” says Leppink. “My diagnostic will measure that edge region on the high-field side near the launcher in great detail, which provides us a way to directly verify calculations or compare actual results with simulation results.”

      Although focused on his own research, Leppink has excelled at priming other students for success in their studies and research. In 2021 he received the NSE Outstanding Teaching Assistant and Mentorship Award.

      “The highlights of TA’ing for me were the times when I could watch students go from struggling with a difficult topic to fully understanding it, often with just a nudge in the right direction and then allowing them to follow their own intuition the rest of the way,” he says.

      The right direction for Leppink points toward San Diego and RF current drive experiments on DIII-D. He is grateful for the support from the SCGSR, a program created to prepare graduate students like him for science, technology, engineering, or mathematics careers important to the DOE Office of Science mission. It provides graduate thesis research opportunities through extended residency at DOE national laboratories. He has already made several trips to DIII-D, in part to install his reflectometer, and has been impressed with the size of the operation.

      “It takes a little while to kind of compartmentalize everything and say, ‘OK, well, here’s my part of the machine. This is what I’m doing.’ It can definitely be overwhelming at times. But I’m blessed to be able to work on what has been the workhorse tokamak of the United States for the past few decades.” More

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      in Energy

      MIT expands research collaboration with Commonwealth Fusion Systems to build net energy fusion machine, SPARC

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      MIT’s Plasma Science and Fusion Center (PSFC) will substantially expand its fusion energy research and education activities under a new five-year agreement with Institute spinout Commonwealth Fusion Systems (CFS).

      “This expanded relationship puts MIT and PSFC in a prime position to be an even stronger academic leader that can help deliver the research and education needs of the burgeoning fusion energy industry, in part by utilizing the world’s first burning plasma and net energy fusion machine, SPARC,” says PSFC director Dennis Whyte. “CFS will build SPARC and develop a commercial fusion product, while MIT PSFC will focus on its core mission of cutting-edge research and education.”

      Commercial fusion energy has the potential to play a significant role in combating climate change, and there is a concurrent increase in interest from the energy sector, governments, and foundations. The new agreement, administered by the MIT Energy Initiative (MITEI), where CFS is a startup member, will help PSFC expand its fusion technology efforts with a wider variety of sponsors. The collaboration enables rapid execution at scale and technology transfer into the commercial sector as soon as possible.

      This new agreement doubles CFS’ financial commitment to PSFC, enabling greater recruitment and support of students, staff, and faculty. “We’ll significantly increase the number of graduate students and postdocs, and just as important they will be working on a more diverse set of fusion science and technology topics,” notes Whyte. It extends the collaboration between PSFC and CFS that resulted in numerous advances toward fusion power plants, including last fall’s demonstration of a high-temperature superconducting (HTS) fusion electromagnet with record-setting field strength of 20 tesla.

      The combined magnetic fusion efforts at PSFC will surpass those in place during the operations of the pioneering Alcator C-Mod tokamak device that operated from 1993 to 2016. This increase in activity reflects a moment when multiple fusion energy technologies are seeing rapidly accelerating development worldwide, and the emergence of a new fusion energy industry that would require thousands of trained people.

      MITEI director Robert Armstrong adds, “Our goal from the beginning was to create a membership model that would allow startups who have specific research challenges to leverage the MITEI ecosystem, including MIT faculty, students, and other MITEI members. The team at the PSFC and MITEI have worked seamlessly to support CFS, and we are excited for this next phase of the relationship.”

      PSFC is supporting CFS’ efforts toward realizing the SPARC fusion platform, which facilitates rapid development and refinement of elements (including HTS magnets) needed to build ARC, a compact, modular, high-field fusion power plant that would set the stage for commercial fusion energy production. The concepts originated in Whyte’s nuclear science and engineering class 22.63 (Principles of Fusion Engineering) and have been carried forward by students and PSFC staff, many of whom helped found CFS; the new activity will expand research into advanced technologies for the envisioned pilot plant.

      “This has been an incredibly effective collaboration that has resulted in a major breakthrough for commercial fusion with the successful demonstration of revolutionary fusion magnet technology that will enable the world’s first commercially relevant net energy fusion device, SPARC, currently under construction,” says Bob Mumgaard SM ’15, PhD ’15, CEO of Commonwealth Fusion Systems. “We look forward to this next phase in the collaboration with MIT as we tackle the critical research challenges ahead for the next steps toward fusion power plant development.”

      In the push for commercial fusion energy, the next five years are critical, requiring intensive work on materials longevity, heat transfer, fuel recycling, maintenance, and other crucial aspects of power plant development. It will need innovation from almost every engineering discipline. “Having great teams working now, it will cut the time needed to move from SPARC to ARC, and really unleash the creativity. And the thing MIT does so well is cut across disciplines,” says Whyte.

      “To address the climate crisis, the world needs to deploy existing clean energy solutions as widely and as quickly as possible, while at the same time developing new technologies — and our goal is that those new technologies will include fusion power,” says Maria T. Zuber, MIT’s vice president for research. “To make new climate solutions a reality, we need focused, sustained collaborations like the one between MIT and Commonwealth Fusion Systems. Delivering fusion power onto the grid is a monumental challenge, and the combined capabilities of these two organizations are what the challenge demands.”

      On a strategic level, climate change and the imperative need for widely implementable carbon-free energy have helped orient the PSFC team toward scalability. “Building one or 10 fusion plants doesn’t make a difference — we have to build thousands,” says Whyte. “The design decisions we make will impact the ability to do that down the road. The real enemy here is time, and we want to remove as many impediments as possible and commit to funding a new generation of scientific leaders. Those are critically important in a field with as much interdisciplinary integration as fusion.” More