From “never” to now: NIF through the lens of 60 Minutes

January 23, 2023, 12:00PMNuclear News
NIF in winter (Photo: LLNL)

“Star Power” is the name 60 Minutes producers gave their interpretation of the recent experiment at the National Ignition Facility (NIF) that achieved fusion ignition and net gain. Views from inside Lawrence Livermore National Laboratory captured by TV cameras and aired Sunday, January 15—of some of NIF’s 192 lasers, banks of capacitors, target assembly labs, and even the remains of the target assembly blasted in the December 5 breakthrough—are well worth the watch for those of us who are unlikely to visit the site in person.

In just over 13 minutes of airtime, 60 Minutes correspondent Scott Pelley asked questions about the experiment he likened to the Wright brothers’ first flight and probed the prospects—and timeline—for inertial fusion energy (IFE) in conversations designed to pique the interest of his TV audience. (Eyelashes and cat whiskers have been used to apply glue during target assembly? Who knew?)

The three LLNL employees interviewed by Pelley were among those who spoke during a livestreamed DOE panel discussion and media Q&A on December 13. Nuclear Newswire went back to hear what they had to say on that day and learned why there is good reason to expect NIF to break its latest record sooner rather than later. Inspired by 60 Minutes, we also revisited the long years of work at NIF that preceded ignition—as recorded in headlines from the Nuclear News archives.

NIF’s growing pains: Current LLNL lab director Kim Budil acknowledged to Pelley that NIF had earned nicknames over the years such as the “Not Ignition Facility,” “Never Ignition Facility,” and “Nearly Ignition Facility.” But now, Budil said, “This recent event has really put the ignition in the NIF.”

Construction of NIF, as a controlled fusion machine to study high-energy, high-density conditions in detail—and in service of the nation’s nuclear deterrent—began in 1997. Nuclear News recorded several steps along the way, including what then LLNL associate director at large John Nuckolls shared at the 1994 ANS Annual Meeting about plans for NIF and the potential of IFE (Aug. 1994, p. 64):

In a magnetic fusion power plant, overall costs are significantly increased by the costs of the giant magnetic confinement system and the large-scale size set by the relatively low-density fusion plasma and by neutron damage to the first wall. It has been suggested that lower costs may be achieved by utilizing inertial confinement of the fusion plasma. Then the magnetic confinement system would be eliminated, the first wall could be shielded from neutron damage by fluid layers, and the scale size could be reduced. However, for [IFE], a low-cost driver technology must be developed to ignite small-scale fusion explosions.

For a power plant, an indirect-drive target similar to that to be tested on NIF would be driven by a high-efficiency, high-average-power heavy-ion accelerator such as that now being developed at the Lawrence Berkeley Laboratory.

Once NIF construction was complete in 2009, nearly 200 ignition attempts were made over 13 years. From 2010 to 2022, these Nuclear News headlines told the story of NIF—and suggest how it got its nicknames:

NIF’s 1-MJ shot sets stage for ignition demo (Mar. 2010, p. 103)—“The NIF is scheduled to begin experiments this summer with what are referred to as ‘ignition-like fuel capsules’ to show whether this system can produce ignition and significant net energy gain. . . .”

GAO finds problems at National Ignition Facility (June 2010, p. 118)—“Later this year, the National Ignition Facility at Lawrence Livermore National Laboratory may become the first controlled thermonuclear fusion facility in the world to achieve ignition of deuterium-tritium fuel. The Government Accountability Office, however, has doubts about whether the NIF will achieve ignition at all, in this year or any other. . . .”

NIF achieved its first 500-terawatt laser shot (Aug. 2012, p. 175)—“The National Ignition Facility at Lawrence Livermore National Laboratory is continuing to advance toward the goal of ignition of fusion fuel, although the July 5 firing was not set up to attempt this, as the target did not contain the mix of deuterium and tritium necessary for high-gain fusion. The shot was stated as ‘more than’ 500 TW, and it delivered 1.85 megajoules of energy to the target. . . .”

NIF ignition work will be on hold for three years (Jan. 2013, p. 75)—“In a late November report required by a congressional directive, the NNSA [National Nuclear Security Administration] stated that because the National Ignition Facility did not meet its goal of achieving the ignition of fusion fuel by the end of fiscal year 2012, the ICF [inertial confinement fusion] effort will focus on further research using the University of Rochester’s Omega laser and Sandia National Laboratories’ Z Machine, as well as the NIF at Lawrence Livermore National Laboratory. The research will be aimed at resolving issues that arose in the ignition effort, such as why the computer codes that simulated how the NIF fusion fuel pellets should have imploded and ignited did not agree with the results of real-world experiments. . . .”

What’s next for the inertial confinement fusion effort? (Mar. 2013, p. 98)—“Despite the enthusiasm and confidence of earlier years, the National Ignition Campaign, which ended on September 30, 2012, was unable to achieve the ignition of fusion fuel using the laser-driven National Ignition Facility at Lawrence Livermore National Laboratory. The Department of Energy recently issued a report by a team of experts who reviewed the NIC’s work as the campaign ended. . . .”

Did NIF produce net energy? (Nov. 2013, p. 80)—“The passage seemed carefully worded, even properly British: ‘The BBC understands that during an experiment in late September, the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel—the first time this had been achieved at any fusion facility in the world.’

“This was the fifth paragraph in an article posted on the BBC news website on October 7, and it referred to the National Ignition Facility at Lawrence Livermore National Laboratory in the United States. Paul Rincon, the website’s science editor, did not provide details of the experiment, nor did he identify or quote individuals who had participated in it. In the immediate aftermath of the article’s posting, however, there were indications that the author had sufficient reason to make the statement. . . .”

By one definition, NIF exceeded breakeven (Apr. 2014, p. 66)—“The mystery of the National Ignition Facility’s experimental results from last September was resolved for certain in the journal Nature on February 12, with the publication of a paper by Lawrence Livermore National Laboratory researchers. It was already known that these experiments had produced the best results yet at NIF, although while the paper was undergoing peer review, LLNL declined to state officially that a break-even milestone had been achieved. It is a narrowly defined breakeven, however, far short of complete net energy gain or NIF’s true goal, ignition of all of the fuel in a pellet. . . .”

NNSA establishes less ambitious goal (Aug. 2016, p. 124)—“The Department of Energy’s National Nuclear Security Administration, which oversees the federally funded ICF program, decided—after the missed 2012 ignition target date—to set new goals and planned to spend at least three years on this effort. In its 2016 Inertial Confinement Fusion Program Framework, the NNSA announced those goals, the principal one of which is to ‘determine the efficacy of NIF for achieving ignition,’ and to make this determination by 2020. . . .”

National Ignition Facility experiment achieves record-breaking yield (Oct. 2021, p. 92)—“A single experiment lasting a split second has injected a burst of enthusiasm into the fusion community—a realm where progress has been measured in decades—and captured the attention of the general media as well. Lawrence Livermore National Laboratory announced on August 17 that an August 8 experiment at the National Ignition Facility had yielded more than 1.3 megajoules of energy—eight times more than the yield from experiments conducted this spring and 25 times more than NIF’s 2018 record yield. . . .”

Breakeven breakthrough at the National Ignition Facility (Newswire, December 13, 2022)—“It’s official: Early in the morning on December 5 at Lawrence Livermore National Laboratory’s National Ignition Facility, the laser-triggered implosion of a meticulously engineered capsule of deuterium and tritium about the size of a peppercorn yielded, for the first time on Earth, more energy from a fusion reaction than was delivered to the capsule. The input of 2.05 megajoules to the target heated the diamond-shelled, spherical capsule to over 3 million degrees Celsius and yielded 3.15 MJ of fusion energy output. The achievement was announced earlier today by officials and scientists representing the Department of Energy and its National Nuclear Security Administration, the White House, and LLNL during a livestreamed event. . . .”

Fusion conflation: After Tammy Ma, lead for LLNL’s Inertial Fusion Energy Institutional Initiative, explained to Pelley how the NIF’s rep rate and energy yield would need to be scaled up for a laser IFE power plant, Pelley questioned the goal of “achieving commercial fusion within a decade” offered by energy secretary Jennifer Granholm during the December 13 livestream.

Pelley’s reporting focused on the decades that may be required for laser IFE, while mentioning that “more than 30 private companies designing various approaches to fusion power, including using magnets, not lasers. Three billion dollars in private money flowed into those companies in the last 13 months, including bets by Bill Gates and Google.”

What Pelley didn’t mention is that most of those funds went to magnetic fusion energy (MFE) concepts, which thanks to decades of tokamak research around the world and recent advances in superconducting magnets may be closer to deployment than IFE. Several private companies have announced fusion power goals in the early 2030s. International megaproject ITER, near-term MFE demonstrations with a smaller footprint planned by private companies, and hybrid magneto-inertial fusion concepts with demos planned—all perhaps closer to operation than power from laser-driven IFE—did not get a mention on 60 Minutes.

As Ma said on December 13 during the DOE’s livestream, “There’s definitely pros and cons for each different approach. . . . Both magnetic fusion and inertial have made great advances in the past couple of years. There’s also been enormous private sector investment, actually more on the magnetic side than the inertial side in recent years.

“I think what we’ve been able to demonstrate on the NIF is a burning plasma, and we’ve gotten gain. However, like [Budil] alluded to, we’re a little bit farther behind [magnetic fusion] in some of the technology developments because that’s just not what we’ve been focused on the past few years. That being said, there’s a lot of commonalities between the two, where we can learn from each other. . . . A win for either inertial or magnetic confinement is a win for all of us, and we really just want to see fusion energy happen.”

Not just a lucky shot: On 60 Minutes, Pelley asked Budil: “Can you do it again?”

“Absolutely,” she replied.

The six LLNL researchers Budil introduced as “the rockstars from Livermore” in the December 13 DOE livestreamed panel discussion and Q&A moderated by Mark Herrmann, LLNL program director for weapons physics and design, provided details about the December 5 shot. Some of those details help explain why the team is confident that the net gain they achieved predicts future success—and wasn’t just a lucky shot.

Laser capabilities: Jean-Michel Di Nicola, chief engineer for the NIF laser system, explained that his team is “in the process of modernizing what we call the front end of the laser, which is based on fiberoptics technology. The NIF laser was first commissioned at low level in 2001, so this part of the laser was literally 20 years old. And as you can imagine, in the telecom industry over 20 years there have been many revolutions, and so we were able to catch up and capitalize on the latest technologies to improve this delivery.”

Target design changes: Recent design changes take advantage of those new laser capabilities, including “making the capsule that holds the fusion fuel a little bit thicker. That does two things: that gives us more margin for achieving ignition when we have nonoptimal fielding conditions, as well as it lets us burn up more of the DT [deuterium-tritium] fusion fuel,” explained Annie Kritcher, the principal designer and team lead for integrated modeling.

Target imperfections: Michael Stadermann, the target fabrication program manager, explained on 60 Minutes that “the precision that we need for making these shells is extreme. The shells are almost perfectly round. They have a roughness that is a hundred times better than a mirror.”

Yet compared to the target used for the previous record shot of August 2021, the target used on December 5 “had a substantial number of flaws,” Stadermann explained on December 13. “How strongly an experiment is affected by the flaws depends on the design input . . . and it looks like the result from [December 5] is a more robust design that is less affected. This is very encouraging for us because we know that the shell that we shot had flaws in it, and this gives us confidence that we can make shells of equal quality or even better quality in the future, that we’ll be able to reproduce this experiment or even improve on it.”

Calculated symmetry: Kritcher explained that an experimental shot in September 2022 took advantage of both the recent laser improvements and a thicker shell to achieve a yield close to the 1.3 MJ of August 2021, but with a target capsule that (like the one used December 5) had more flaws. For the December shot that achieved ignition, “The only changes to the input conditions were to improve [the] intrinsic low-modes asymmetry,” Kritcher said, which makes “the implosion more symmetric as it’s coming in. You can better couple your driver energy to the hot plasma.”

Kritcher explained, “During the second half of the laser time history, we transferred more energy between laser beams to control the symmetry. That’s actually quite a useful tool. . . . You can move energy between beams and control symmetry that way. In doing so, you have to go back and readjust the symmetry during the first half of the laser pulse and we did that making an additional adjustment with improved models based on data that were collected just in the last few months. We really do rely on our models to benchmark against tuning data and then extrapolate out to the design space.”

Fuel burn: Just 4 percent of the DT fuel in the December 5 target capsule actually burned, according to Alex Zylstra, the principal experimentalist for the record-breaking shot. That leaves plenty of room for improvement—and fusion energy gain.

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