Developing research capabilities for extreme environments
For several decades, PLS scientists have explored matter at extreme temperatures and pressures—an exciting research field that continues to rapidly evolve. They bring their expertise in high energy density science (HEDS) to research projects involving fusion science, materials at extreme conditions, astrophysics, stockpile modernization, and our nation’s deterrence capabilities. For example, PLS researchers played key roles on teams that achieved thermonuclear ignition at LLNL’s National Ignition Facility (NIF). They also study HED behavior relevant to assessing the performance of our nation’s aging nuclear stockpile and future defense capabilities.
New diagnostics, models, and experimental designs
One way that PLS research teams contribute to these efforts is by developing and fielding diagnostics used in HEDS experiments, including experiments at NIF used to study fusion energy and weapons physics. Physicists and materials science experts from PLS helped develop and refine most of the 150+ NIF diagnostic instruments. Dozens of these optical, x-ray, and nuclear diagnostics are used during each NIF experiment, helping researchers collect and analyze data regarding extreme conditions. Examples include:
- X-ray imaging diagnostics that enable ignition by tuning the drive symmetry and revealing the impact of target features and imperfections.
- Diagnostics used during high-yield shots, such as high-resolution imaging of hydrodynamic instabilities.
- Diagnostics that measure diffraction patterns, enabling researchers to analyze the structure of highly compressed materials.
Many of these diagnostic concepts are tested during experiments at smaller laser facilities, including LLNL’s Jupiter Laser Facility, as well as lasers located at other research facilities. Following this initial research stage, new diagnostics are deployed and refined at NIF.
In addition, multidisciplinary teams from our directorate’s Physics, Materials Science, and Nuclear and Chemical Sciences divisions help plan and conduct HEDS experiments with scientists from NIF, as well as researchers from LLNL’s Strategic Deterrence Directorate. For example, they develop new experimental designs to achieve ignition and tune those designs to attain successful implosions. PLS teams also contribute to NIF experiments by:
- Developing and testing new laser optics that can withstand higher laser intensities.
- Improving target fabrication in order to reduce tiny defects that introduce errors during HEDS experiments.
- Exploring ways to leverage additive manufacturing techniques to fabricate targets.
Our teams also develop and refine models powered by LLNL’s supercomputers that can simulate processes that occur during HEDS experiments. These models are used in radiation hydrodynamics codes to more accurately simulate ignition and HEDS experiments. They help scientists reduce the time needed to design and scale-up new solutions.
Collaborations drive innovation
As our teams explore ways to tackle emerging challenges—such as creating new diagnostics and new target designs, they collaborate with internal and external partners. These multidisciplinary, multi-institutional research teams include experts from LLNL and our partnering national labs and academic institutions.
In addition, we are expanding our collaborations with industry experts, enabling us to leverage their insight as we study options for producing commercial fusion energy, including inertial confinement fusion and magnetic fusion energy. The Livermore Institute for Fusion Technology (LIFT) helps foster these new connections, recognizing that together, we can accelerate development of innovative solutions.
Studying our solar system and looking to the future
Although most of the HEDS activities involving PLS scientists have a national security or fusion energy research focus, our researchers do also study the physics of our solar system, from Earth’s core to supernovae. These investments impact basic science, while also bolstering development of future HEDS capabilities that can be used in our deterrence and fusion science research.
As I reflect on our past accomplishments in HEDS research, I’m also eager to see where we will head in the future. I’m confident that PLS researchers will continue developing innovative new solutions that will enable us to study higher temperatures and pressures than we can explore today. This research domain is changing rapidly, and we want to be ready to meet tomorrow’s challenges.
– Glenn Fox, PLS Principal Associate Director
