Laser Fusion Pioneer Lindl Celebrates Five Decades at LLNL

NIF Senior Scientist John Lindl, who was instrumental in launching LLNL’s successful effort to achieve fusion ignition, has been recognized for his 50 years of service at the Laboratory.

NIF & Photon Science Principal Associate Director Jeff Wisoff praised Lindl’s long and productive career during a recent employee picnic. “That’s just an incredible contribution to the Lab over so many years,” Wisoff said.

In response, Lindl noted that he’s actually in his 51st year, but he said being part of the team that achieved ignition in his 50th year on Dec. 5, 2022, “was amazing” and that “there’s no better award that I could have gotten.

“Livermore has been unique in getting to this point,” Lindl said. “There’s no other laboratory anywhere in the world that’s within a decade or two of the accomplishment that we’ve made.

“It’s required the sustained support of every (LLNL) director since Roger Batzel (Lab director from 1971 to 1988),” he said. “Without that kind of sustained support, this kind of accomplishment for something this hard couldn’t have ever been done.

“So I’m proud to be here and I hope to be here for years to come. IFE (inertial fusion energy) is the future.”

Shortly after ignition was achieved, Lindl, who presented the original proposal for NIF to the National Academy of Science in 1989, recalled how the Academy gave the project only a 50-50 chance that it would actually work.

“I would say that, by far, the majority of the scientific community was very skeptical, if not downright dismissive, of the likelihood that we would succeed,” he said. “But there have been enough people who believed we could do it and sustained the support for what we’ve been doing that got us to this point.

“Fortunately, we were on the positive side of the 50-50 proposition.”

Lindl majored in engineering physics at Cornell; as a senior, his fascination with lightning led him to take an elective course in plasma physics. He decided to pursue a graduate degree in plasma physics at Princeton University, where he received his Ph.D. in astrophysics, and hoped to do a thesis on lightning but was unable to find a thesis advisor on the subject. Through his thesis advisor John Dawson, he learned about the early work on inertial fusion at LLNL.

He joined the Laboratory in 1972 as a physicist concentrating on fluid instabilities and high-gain inertial confinement fusion (ICF) targets, and soon began researching the effects of laser-plasma interactions with a team that included fellow inertial fusion pioneers John Nuckolls, who served as Lab Director from 1988 to 1994, George Zimmerman, Lowell Wood, Claire Max—Lindl’s classmate at Princeton—and Bill Kruer—also from Princeton—among others (see “A Legacy of Lasers and Laser Fusion Pioneers”).

“At the time, there weren’t many jobs in fusion,” Lindl later recalled. “This was a program that was just getting off the ground, and it seemed like an intriguing opportunity for a young person like me to get involved in a whole different approach to fusion. Magnetic fusion was by then already 20-plus years old and a relatively mature field compared to laser fusion, which was just getting going.”

In 1976, Lindl designed the first laser-driven x-ray drive implosions, a successful series of experiments that used the single-beam Cyclops laser. He became the leader of the Laser Target Design Group in 1978, was named associate program leader for theory and target design in the ICF Program in 1983, and was selected as program leader of the Nova Laser Program in 1990.

Lindl’s integrated model for ignition served as the basis for the 10-beam Nova, which was designed to test the key physics issues and to ultimately set the design requirements for NIF, a two-megajoule laser intended to demonstrate thermonuclear ignition and burn in the laboratory.

In 1993, Secretary of Energy Hazel O’Leary declassified much of the previously secret data that LLNL scientists had developed over the previous two decades regarding ICF. Lindl was encouraged to write a lengthy scientific paper in the journal Physics of Plasmas summarizing the work, which to this day is often the first article cited by ICF researchers around the world. In 2020 Stanford University listed Lindl among the top 2 percent of the most-cited researchers worldwide throughout their careers.

The article was so successful that in 1997, Lindl turned his material into a seminal book, Inertial Confinement Fusion: The Quest for Ignition and Energy Gain Using Indirect Drive, a widely used reference for the science of inertial fusion. Besides being a reference work for the fundamental physics of ICF, the book summarized the key accomplishments of the ICF program from the early 1970s until the declassification of ICF in 1993.

“I first learned about ICF from his famous 1995 Physics of Plasmas article when I was a postdoc at UCLA,” said LLNL ICF Chief Scientist Omar Hurricane. “Many researchers in ICF learned the basics from Lindl’s many written works. He is still a prolific author even today.”

Lindl became ICF scientific director in 1994, and beginning in 2000, he led LLNL’s newly combined magnetic and inertial fusion energy programs. Construction of NIF, the world’s largest and highest-energy laser system, began in 1997 and was completed in 2009; Lindl served as NIF Programs chief scientist from 2006 to 2013.

“It was my great good fortune to join Livermore just as the capabilities in modeling, lasers, and diagnostics were reaching a level of maturity that would enable a sustained effort to achieve fusion ignition in the laboratory,” he said. “Livermore’s long-standing willingness to take big risks for big rewards has provided me with the unique opportunity to pursue this grand-challenge scientific goal.”

More than ten years ago, while NIF was still under construction, Lindl discussed how fusion research can support the growing international drive for fusion energy and thus benefit human civilization.

“To me, by almost any measure, this is a great time to be alive,” he said. “The question to me is how do we sustain and expand the wealth we have, particularly in the West, so that the rest of the world can live in similar well-being. Energy is a key component of that. Energy and wealth generally scale together.”

The Promise of Fusion

According to Lindl, it’s clear that the world will eventually deplete its supply of fossil fuels. Renewable sources such as solar, wind, and wave power are good alternatives, but can’t fulfill all of our needs, he said. And while nuclear fission has a demonstrated capability with many attractive features as an energy source, Lindl acknowledged that serious problems, such as waste disposal, still need to be addressed.

“Fusion has the largest energy potential of all options for the future, with many attractive features,” he said. “The problem of radioactive waste is greatly reduced compared to fission. The fuel is widely available, with one barrel of seawater containing roughly the equivalent to 300 barrels of oil in the hydrogen isotope deuterium.”

While NIF’s research focuses on supporting LLNL’s stockpile stewardship mission, achievement of ignition also encourages people to take commercial fusion power seriously, Lindl said recently.

“Having now achieved a target gain greater than one, people are now seriously (asking,) ‘All right, how do we make the next step?’” he said.

The son of a forester, Lindl is an avid hiker who enjoys backpacking and exploring the Livermore wine country with his family. He celebrated his 60th birthday in 2006 by going on a solitary 500-mile walk through the Sierras.

“For all the years my daughters were growing up, backpacking trips were our family vacation,” he said. “They started at six and seven and still like it!

“I do not get out as often or for as long as I used to, but my daughters cleared their schedules last fall so they could take me on a five-day backpack trip to a place we love in the Emigrant Wilderness.”

Lindl is a Fellow of the American Physical Society (APS) and of the American Association for the Advancement of Science. He was awarded the 2007 James Clerk Maxwell Prize in Plasma Physics by the APS. He also received the Edward Teller Medal from the American Nuclear Society in 1993 and the E.O. Lawrence Award for his work in ICF in 1994. He is the recipient of the 2000 Fusion Power Associates Leadership Award and was named an LLNL Distinguished Member of Technical Staff in 2011 for his extraordinary scientific and technical contributions to the Laboratory and its missions.

“I like to think of human knowledge as sort of a tapestry that you’re working on,” Lindl said. “You have a giant puzzle, where you have a few pieces, and you’re trying to figure out where the next piece should go and what is it going to look like when it’s all done.

“In our case,” he continued, “you actually have to make the pieces. You don’t just have a box where you’re trying to put them together. You have to make the pieces and try to figure out whether you got it right or not—whether it fits.

“Achieving fusion ignition in the laboratory has been an extraordinary challenge, and our recent success on the NIF provides an important piece in the overall tapestry of knowledge now available to all human beings.”

More Information:

“Development of the indirect‐drive approach to inertial confinement fusion and the target physics basis for ignition and gain,” Physics of Plasmas, November 1, 1995

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