NIF&PS Intern Brings New Perspectives to NIF
Marie Durivaux was a unique choice for an internship to develop additional tools and further analyze laser beam quality at NIF.
Durivaux was at the time a graduate student in engineering, with a special interest in optics and photonics, at the Institut d’Optique Graduate School of Paris-Saclay University. She is completing a three-year apprenticeship with the French Alternative Energies and Atomic Energy Commission (CEA).
Since she already had experience with how laser beam shaping is done at the CEA’s Laser Mégajoule (LMJ), which like NIF is one of the world’s biggest laser research facilities, she was prepared for an internship with NIF’s Laser Science & Systems Engineering (LSSE) program.
Moreover, Durivaux’s journey across the Atlantic Ocean was made possible by French engineering program requirements that compel students to complete a mandatory semester abroad, providing them with the opportunity to experience an international setting.
“At NIF, I saw the other side of things, so it's very interesting to see both from a work-environment perspective, but also from the scientific perspective,” Durivaux says. “It's laser physics and computer science.”
Durivaux, who graduated in December, says she was excited about working in the field of optics and photonics, “the next big thing after electronics,” and proud that her work contributed to improve the understanding of NIF beam spatial quality.
She enjoyed “making sure NIF keeps being as efficient as possible for the next decades to come and boosting the energy performance even higher,” she says.
The internship required an “understanding of how the laser works and the technologies and tools that you need to put in place,” says Jean-Michel Di Nicola, LSSE co-program director. “So, Marie was a perfect fit. We were really lucky to have her.”
The strong history of collaboration between LLNL and the CEA was interwoven into her Livermore internship, which involved programmable spatial shaper (PSS) devices. The PSS devices are designed to spatially modulate the fluence (spatial energy distribution) of the beams and reduce the hot spots at the main laser output, lowering the flaw initiation rate that is strongly driven by the hot spots. These devices are also used to deploy small circular obscurations—so-called “spot blockers”—to arrest the growth of flaws in NIF’s final optics (see “Spot-Shadowing Damage on Laser Optics”).
In the summer of 2023, the annual co-chair meeting between LLNL, CEA, and the National Nuclear Security Administration (NNSA) focused, beyond the scientific and technical exchanges, on building the next generation of laser facility stewards, including cross-training of interns and career employees to serve the NNSA’s science-based Stockpile Stewardship Program to ensure the safety and security of the nation’s nuclear deterrent.
Durivaux stood out because her CEA apprenticeship included analyzing data about the quality of beam shaping at LMJ, making it easier to compare the beam quality obtained on the two facilities.
“It was really good that Marie had the background on optics, optical engineering, and image and signal processing,” Di Nicola says. “But she also was acquainted with high-energy inertial confinement fusion, so she could be really quick on her feet and have an impact almost a couple of days after landing.”
When she arrived at NIF last summer, she was able to compare and contrast the methodologies used at both facilities. Her role also was to enhance the image analysis software with a system engineering view of the entire process with the NIF laser performance and computer science teams. During her internship, Marie worked closely with Kathleen McCandless, group leader in NIF Computing and also the lead for the Laser Performance Operations Model software team.
“It was not something in total contrast to what she was doing, but it opened up her horizons, doing something in a different way, in a different culture, in a different environment, with different tools,” Di Nicola says.
Meanwhile, LLNL is always open to “learning a different point of view of peers who are also on the international stage,” he says. “Because if we are just talking to ourselves inside the fence, we may be missing big-time opportunities for improvement.”
Durivaux also gained new perspectives. She enjoyed comparing the histories of LMJ and NIF, which started experiments in 2009 only when construction of all 192 beamlines was completed and comparing their relative performance. LMJ, which is conducting experiments while the facility is still being constructed, has to date reached about 300 kilojoules of ultraviolet energy and will continue its energy rampup over the next several years.
“The French took a different approach,” she says. “They’re both building LMJ, getting the beamlines in, and using it for experiments.”
The internship proved enlightening for Durivaux.
“The internship had a much tighter connection to research and theoretical physics than what I was exposed to during my previous experiences,” she says. “The perspective I gained through Jean-Michel's mentorship and the sneak peek into that part of the work helped me anchor and contextualize my skills, as well as gain insight into the direction of my professional career.”
She noted the cultural differences as well. “Although I wouldn't say LLNL and NIF are typical examples of U.S. work culture, they still present a stark contrast to the French way of doing things,” she says. “Being exposed to these cultural differences is enlightening and thought-provoking.
“On a personal level though, the most significant impact was that it forced me to step out of my comfort zone—both from a work and social point of view—allowing me to grow in confidence and ‘outgoingness.’ In France, we have a saying: “Le voyage forme la jeunesse,” which translates to “Travel shapes youth.”
Her route to becoming a scientist wasn’t always so obvious. She always loved science and mathematics, especially since her parents were engineers. Her three brothers were also interested in science. “It kind of runs in the family,” she says.
At a very young age, however, she engaged in several years of intensive training pursuing her dream to become a professional ballet dancer.
“Then going into high school, I had to choose between either continuing that career or focusing on my studies, and I realized it was more fulfilling to study science,” she says.
“I liked the idea of discovering the truth about the world, the underlying truth, and that it’s a human endeavor to strive for more knowledge. The mindset of science, the scientific method, is a net benefit for people to know and practice in their daily lives, even if we don’t do science as a job.”
More Information:
“LLNL Hosts French Alternative Energies and Atomic Energy Commission Leaders,” NIF & Photon Science News, September 10, 2024
“Spot-Shadowing Damage on Laser Optics,” Science & Technology Review, June 2024
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