Feb. 7, 2023 — Lawrence Livermore National Laboratory (LLNL)’s historic achievement of fusion ignition on December 5th at the National Ignition Facility (NIF) positions the United States with a “unique opportunity” to further lead the world scientific community’s pursuit of developing fusion as a future source of clean energy, according to a newly released report.

Capitalizing on that opportunity will require a renewed, robust and rapidly paced program of inertial fusion energy (IFE) research that coordinates efforts from the public, private and academic sectors. This conclusion comes from the U.S. Department of Energy (DOE) Office of Science-sponsored “IFE Basic Research Needs” (BRN) report, which resulted from a three-day workshop last June and many months of work by a panel of experts.

“There is a huge amount of momentum in the fusion field right now, which gives us a very special opportunity to grow the national IFE program and accelerate the development of fusion energy by leveraging our leadership in inertial confinement fusion (ICF), developing new collaborations through public-private partnerships and working closely with DOE and the community,” said LLNL physicist Tammy Ma, the lead for the Laboratory’s Inertial Fusion Energy Institutional Initiative.

The virtual Basic Research Needs workshop, chaired by Ma and Professor Riccardo Betti of the University of Rochester, brought researchers and IFE supporters together to explore the science, technology and investments needed to realize IFE’s potential (see “DOE Workshop Examines Inertial Fusion Energy Research Needs”).

The workshop, held from June 21 to 23, was convened as momentum for IFE accelerated in the wake of NIF’s Aug. 8, 2021 experiment that produced 1.35 megajoules (MJ) of  fusion energy, bringing NIF to the threshold of ignition.

During the months both before and following the workshop, 120 panelists invited by DOE worked together to author the “Basic Research Needs” report, which will become a foundational guide for DOE to establish a national IFE program.

The report was basically completed by Dec. 5. But on that day, NIF provided IFE an even bigger shot of momentum when an ICF experiment attained ignition—the long-sought “proof of concept” that the same thermonuclear fusion reaction that powers the sun, the stars and nuclear weapons, can be reproduced in a laboratory.

NIF, the world’s largest and most energetic laser system, used its 192 lasers for an ICF experiment that yielded 3.15 megajoules (MJ) of energy compared to 2.05 MJ of laser energy that was delivered to the target. This feat established a scientific energy gain of 1.5, over the gain of 1 used by the National Academy of Sciences to define ignition, and provides the “unique opportunity right now to grow the national program by nourishing and leveraging our (US) leadership in ICF,” the 250-page report said.

“With the demonstration of ignition on the NIF, we are at a critical juncture in IFE research,” the report said. “As a community, we can exploit the growing scientific basis of fusion ignition, burn and energy gain for practical applications. We have the opportunity now to incorporate and integrate multiple emerging technologies to make rapid progress.”

But the current infrastructure around ICF, which supports the National Nuclear Security Administration (NNSA)’s Stockpile Stewardship program, and high energy density (HED) physics, designed to improve fundamental understanding of extreme environments, “is insufficient to demonstrate the feasibility of IFE today,” the report said. “A dedicated IFE program is necessary to push for improved utilization of existing infrastructure by increasing the shots available to IFE research.”

The formidable scientific and technological challenges that lie ahead before fusion energy becomes fast, efficient, economical and reliable enough “can be overcome with expanded, coordinated research, development and deployment programs and strategic public-private partnerships,” the report said.

The BRN report’s findings are:

• IFE and magnetic fusion energy (MFE) — which uses powerful magnetic fields — are two main approaches that have different technical risks and benefits. Both should be considered important parts of the DOE’s Fusion Energy Sciences research and development portfolio. Creating and growing a healthy new national IFE program will require the IFE and MFE sectors collaborating to take advantage of technological developments to address common issues.
• NIF’s demonstration of thermonuclear ignition “constitutes a pivotal point in the development of inertial fusion energy.”
• Ignition and other major advances in IFE-relevant physics and technology during the past several decades were mostly funded under the nation’s national security mission, an investment that makes the U.S. “the recognized leader in IFE science and technology.”
• With private industry driving the commercialization of fusion energy in the U.S., “public-private partnerships could greatly accelerate the development of all fusion energy concepts.”
• “Accelerating IFE will require a suite of dedicated, new and upgraded facilities to increase the rate of learning and test new technologies.”
• ICF computer modeling codes primarily reside at NNSA national laboratories, including LLNL. The codes were “built on decades of investment and expertise and constitute a valuable resource for advancing IFE science and technology,” the report said. An assessment of how to access ICF codes optimally and securely for IFE development should be carried out with NNSA.
• Improved diversity, equity and inclusion measures are needed to enhance the climate and culture of the broader field of fusion and plasma research.

Additionally, the report said one national IFE team or partnership should be formed to focus on “making the best use of existing facilities.” The report notes that an IFE science and technology push could leverage existing resources such as LaserNetUS, a broad network of university and government laser research facilities that includes LLNL’s Jupiter Laser Facility.

The report acknowledged that developing a fusion pilot plant still faces challenges that could take years or decades to surmount. Accelerating progress toward building those pilot plants will require evaluating and identifying the most promising concepts and taking advantage of emerging technologies such as exascale computing, artificial intelligence, machine learning, advanced manufacturing and high-rep-rate laser systems.

“We have a unique opportunity right now to grow the national program by nourishing and leveraging our leadership in ICF with unique and world-leading competencies in the underlying science and technology that underpins IFE,” the report said.

LLNL has already been out in front in helping spur development of IFE, including sponsoring a  community workshop last February on the potential for ICF research to generate commercially viable IFE and participating in a DOE workshop on public-private fusion energy partnerships in June.

The Lab also organized a two-day conference, held on Oct. 27 and Nov. 10, that was aimed at creating a “collaboratory” effort between U.S. national laboratories, university researchers and private companies working on various aspects of fusion energy development.

LLNL Director Kim Budil said the achievement of ignition at NIF signals the time is now for a major push to make IFE a reality.

“This report provides an important roadmap to tackle the significant scientific and engineering challenges that still lie ahead on the path toward a fusion energy future,” Budil said. “The report outlines exciting opportunities for LLNL to partner with the entire fusion energy community as we work together to accelerate the development of IFE during what promises to be a transformational decade of high energy density science and fusion research.”

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Source: Benny Evangelista, LLNL