Leading Recommendation: To strengthen its global leadership in high energy density (HED) science and address future national needs, the NNSA should exploit and enhance the capabilities of its flagship HED facilities (e.g., the National Ignition Facility, Z Pulsed Power Facility, and Omega Laser Facility) by establishing plans over the next 5 years for (1) extending, upgrading, or replacing those facilities; (2) increasing the promotion of forefront technology development, including in high-intensity lasers; (3) enhancing academic capabilities and mid-scale facilities; and (4) broadening remote access to its major experimental and computing facilities.

Leading Recommendation: To enhance career pathways for high energy density science research at NNSA facilities, the NNSA should (1) broaden its current programs for achieving excellence through diversity, equity, and inclusion while improving workplace climate and (2) develop a strategic plan for balancing security and proliferation concerns with openness and accessibility, such as for collaborators internationally, and with academia and the private sector.

Major Recommendation: The NNSA should work with the academic and national laboratory user community, relevant government agencies, and industry to develop a high-performance computing (HPC) strategy for high energy density science over the next 2 years. This strategy should include benchmarking and the verification and validation of codes, code comparisons, the close integration of simulations using HPC with experiments, co-development of hardware and software for the research community, open-source documentation of codes and experimental results in a standardized open format (e.g., to enhance use and effectiveness of machine learning and artificial intelligence tools), and an industry-relevant implementation plan.

Major Recommendation: The NNSA and the national laboratories should, in coordination with partner science agencies (e.g., including the Department of Energy’s Office of Science and the National Science Foundation), academia, and industry, set expectations for rigorous benchmark experiments that can provide solid foundations for multi-scale high energy density simulations. Particular emphasis should be given to characterizing material properties under extreme and non-equilibrium conditions, including conditions accessible at university- and mid-scale facilities, and develop a new generation of diagnostics that can take advantage of modern technology such as higher repetition rate (e.g., compact light sources) that access a range of time and length scales.

Major Recommendation: The inertial confinement fusion community should redouble efforts to focus on the underlying basic science to (1) achieve robust ignition and the maximum yield with optimal efficiency, (2) establish the best uses of laboratory burning plasmas, and (3) help identify the best path for future experimental and computational facilities. In particular, the sustainment of innovation and breakthrough research will require a careful balance between yield-producing and non-ignition experiments. Additionally, the NNSA should work with the relevant agencies (e.g., the Department of Energy’s Fusion Energy Sciences and Advanced Research Projects Agency–Energy and the National Science Foundation) and private industry to leverage research in inertial fusion energy and—where possible—partner in research areas of mutual interest.

Recommendation: The NNSA should take steps to enable institutions working on high energy density research to (1) assess the workplace climate; (2) get help from subject-matter experts to make explicit and quantifiable diversity, equity, inclusion, and accessibility (DEIA) goals; and (3) implement and ensure achievement of these DEIA goals.

Recommendation: The NNSA should support more internships, postdoctoral opportunities, faculty visitorships, and early career programs in high energy density science, coordinating across the NNSA in a manner similar to that supported by the Department of Energy’s Office of Science.

Recommendation: The NNSA should provide explicit support and recognition for national laboratory scientists to increase collaborations, mentorship, and outreach with the fundamental research community, in order to build public excitement and the future workforce. Examples include joint appointments or sabbatical opportunities and travel/lectureship programs that partner with minority-serving institutions and the public at large.

Recommendation: The NNSA should periodically assess and, where possible, reduce barriers to university collaborations—for example, by formally recognizing the importance of, and therefore supporting and rewarding, laboratory staff engaged in effective collaborations.

Recommendation: NNSA laboratories should enforce concrete policies for accountability around intolerable, unacceptable behaviors.

Recommendation: In addition to training PhD scientists, NNSA laboratories should invest in educational (apprenticeship) programs at institutions for training of technicians and technical staff at the bachelor’s or master’s level, doing so in line with the laboratories’ diversity, equity, inclusion, and accessibility goals.

Recommendation: NNSA national laboratories should promote collaborations with academia by sharing data related to unclassified research (in consistent data format) and providing open/educational versions of their computational codes.

Recommendation:TheNNSAshouldcollaborativelydevelopindustry-relevant technical roadmaps for critical capabilities in computation, diagnostics, and

targets and provide more—and more frequent—funding opportunities for industry to provide these capabilities.

Recommendation: To strengthen its global leadership in high energy density science and address future national needs, the NNSA should increase the promotion of forefront technology development, and in particular take the necessary steps to achieve ultra-high power laser capabilities on par with what is being developed around the world.

Recommendation: To enhance career pathways for high energy density science research at NNSA facilities, the NNSA should promote international collaborations and increase remote access to those facilities.