2025-2028 Awards

Colorado School of Mines will develop and study granulation techniques that have higher levels of processing controls compared to legacy granulation techniques for high explosives. Using data driven methods and designs, new granulation techniques will be developed that improve upon the current achievable yields and variable controls, producing pressed HE articles with superior physical properties and performance characteristics. Not only is performance a crucial metric of success but is also critical that the proposed granulation methods also prove to produce less hazardous waste material, are sustainable in a production setting, and display potential for scale up-processes. Mines has also established a strong relationship with through collaborative efforts with not only LLNL, but LANL and Sandia National Lab. The efforts of this research will be used to train the next generation of scientists and engineers with expertise that may one day be recruited to work at DOE/NNSA institutions. Mines ERL offers unique opportunities for students to work hands-on with energetic materials under direct supervision, often obtaining experience and knowledge that other institutions may be incapable of facilitating. Students learn the important aspects of safety while designing and conducting their own experiments.

The overarching goals of this research program are: (1) to contribute high-precision nuclear data needed to evaluate the performance of Los Alamos National Laboratory (LANL) designed fuel capsules at the National Ignition Facility (NIF) by using the unique features of the facilities available at the Triangle Universities Nuclear Laboratory (TUNL), e.g., high-intensity mono-energetic neutron beams, an array of excellent HPGe detectors (coaxial, planar, BEGe, and clover), and digital data-acquisition systems, and (2) to educate the next generation of nuclear physicists with expertise in performing neutron and charged particle-induced reaction cross-section measurements. Additionally, they will continue their longtime fruitful collaboration with scientists from LANL through this project. In an effort to obtain cross sections for reactions on tungsten isotopes with higher accuracy and self-consistency, they propose to carry out the following measurements: 1. natW(n,2n) in 0.5 MeV energy steps from 8 to 14 MeV 2. natW(d,n) and natW(d,2n) in 0.5 MeV energy steps from threshold up to 14 MeV 3. natW(p,n) in 0.5 MeV energy steps from threshold up to 14 MeV

The objective of this project is to reduce uncertainties in nuclear data, across a broad neutron energy range, for neutron-induced γ-ray emission from elements that comprise common structural materials: lead, copper, and nickel. This will involve the unique capabilities of TUNL (Triangle Universities Nuclear Laboratory) tandem accelerator laboratory (located on Duke University’s campus) to measure the (n,n’γ) γ-ray production cross sections, which are a potential signature resulting from active interrogation using high energy neutrons. These cross sections will be measured for incident neutron energies from 4.6 to 14 MeV in approximately 2 MeV steps.

The proposed project includes experimental investigations aimed at probing the influence of mesoscale structure on shock wave dissipation and spall failure in Ti alloys. The specific objectives include generating microstructures through controlled heat treatment of additively manufactured beta-phase Ti-5Al-5V-5Mo-3Cr and compositionally-gradient Ti-Ta alloys; determining the extent of shock wave dispersion/disruption caused by competing modes of plasticity via martensitic/twinning transitions or dislocation-mediated slip; establishing effects of dissipative processes on strain-rate strengthening/softening in microstructurally complex Ti alloys and their influence on spall failure strength and damage; mapping process-structure-property-performance through effects of pre-existing and evolving microstructure on dissipative processes and resulting spall failure properties; and educating and training students with scientific knowledge and skillsets in experimental investigations of shock compression, time-resolved optical/x-ray diagnostics, additive manufacturing, and microstructure characterization.

In extreme conditions, characterized by large Mach, Atwood and Schmidt numbers, the mixing process in flows of interest to DOE-NNSA laboratories is highly inhomogeneous and characterized by multiple length and time scales, depending on material properties. There is a strong nonlinear coupling between the mixing process and the underlying turbulence. Detailed data for miscible fluids, suitable for Inertial Confinement Fusion (ICF) model development and validation, is not available for multi-layer configurations, typical of ICF targets. The vision of this proposal is to use novel experimental platforms at the Georgia Tech STAM Lab and state-of-the-art diagnostics to significantly advance the understanding of shock- and buoyancy-driven flows at extreme parameter regimes (of Reynolds number, Mach number, Atwood number). The proposed studies of hydrodynamics-dominated mixing (Rayleigh-Taylor, Richtmyer-Meshkov, and Kelvin-Helmholtz instabilities driven flows) and turbulence under these extreme conditions will allow validation of engineering models for ICF target design and energy deposition. Recent technological advances in quantitative two-tracer Planar Laser Induced Fluorescence (PLIF), for the first time, allow us to experimentally quantify temporally evolving multi-scale interactions between fine scale turbulence and coherent structures associated with underlying hydrodynamic instabilities. The result of this research will be: (a) the development of reliable experimental data sets for the complex set of conditions described, which will be shared with the NNSA community, (b) the advancement of the theoretical understanding of the development of turbulence in instability-driven flows of the type described, and to learn how to better model them, (c) the further development of a new multi-physics probe (two-tracer fluorescence) for mixing studies, and (d) development of a new shock-plasma interaction platform for low-energy density environment turbulent flows, which allows for high resolution density and velocity measurements. The scientific output will provide NNSA scientists with benchmark data to support the verification and validation of existing numerical codes and enhance the development of more predictive models for turbulent mixing that support DOE/NNSA’s objectives.

The main objectives of the proposed project are (1) determining material properties of Earth-like worlds and Water-worlds up to about 1 Tera Pascal (TPa) using the Sandia National Laboratory Z machine, (2) understanding the internal structure of exoplanets and possibility of life on them, and (3) understanding the planet formation/accretion process and how it may lead to the diversity of observed planets.

The objectives can be summarized as follows: 1) Generate new detailed XRT and XRD characterization of heterogeneous geomaterials for a quantitative understanding of morphology, phase fractions, and texture which can be used to initialize digital twins in mesoscale models prior to impact experiments They will study sandstones and quartzite with varying porosity (1-25%) and SiO2 content (77-95%), as well as single-crystal SiO2 in different shock-direction orientations. 2) Generate new in-situ XPCI and XRD data on samples subjected to high strain rates (~104 s-1) and pressures (>1 GPa), capturing kinematics and pore collapse, melt, and phase transitions as well as macroscopic strength. 3) Develop and use new data analysis algorithms and mesoscale models initialized with data from Task 1 outlined in the project narrative and integrated with data from Task 2 to provide quantitative insight into how porosity, phase content, and texture influence thermodynamic and constitutive processes at finely resolved timescales, in dimensions (i.e., 3D) inaccessible to X-ray probes on such short timescales, and at continuum scales.

Michigan State University (MSU) develops advanced models of nuclear fission based on nuclear density functional theory and its time-dependent extensions. They will carry out global calculation of (i) fission yields used in astrophysical simulations of r-process nucleosynthesis and (ii) fission lifetimes of actinide and transactinide nuclei. The fission codes developed under this proposal will be freely used by NNSA researchers and, generally, by the low-energy nuclear physics community. MSU will train junior scientists and students to apply nuclear many-body techniques to describe nuclear fission and other low-energy nuclear phenomena.

The Facility of Rare Isotope Beams (FRIB) at Michigan State University provides the opportunity of obtaining important data on masses of rare isotopes by leveraging high-precision Penning trap mass spectrometry and isotopes produced through in-flight production and separation. This project combines hardware developments that will extend the reach of high-precision mass spectrometry and collaboration between FRIB and LANL scientists to utilize these new capabilities to maximum effect. The objectives of the proposed project are: • Precision mass measurements on radioactive isotopes to provide data that are relevant for Nuclear Structure, Nuclear Astrophysics, and National Security, as identified by FRIB and LANL collaborators and commonly proposed to the FRIB PAC. • Enhancing performance of Penning trap mass spectrometry to maximize the scientific reach in these areas through development of new techniques. • Training students to obtain a broad set of technical, experimental, and analytical skills that prepare them for potential careers at DOE/NNSA laboratories.

The five objectives for the proposed project are as follows. (1) Establish optimized protocol for synthesizing and characterizing trivalent americium and curium, by synthesis and characterization of appropriate surrogate tris pyrazolyl borate lanthanide, namely Nd, Eu, and Gd, compounds with the metals on the single milligram scale. (2) Establish optimized protocol for synthesizing and characterizing tetravalent plutonium by synthesis and characterization of appropriate surrogate tris pyrazolyl borate lanthanide, namely Ce, compounds with the metal on the single milligram scale. (3) Establish optimized protocol for synthesizing and characterizing divalent americium by synthesis and characterization of appropriate surrogate tris pyrazolyl borate lanthanide, namely Eu, Sm, Tm, and Yb, compounds with the metals on the single milligram scale. (4) Synthesize and characterize trivalent americium and curium, divalent americium, and tetravalent plutonium tris pyrazolyl borate compounds. (5) Discover the solubility and stability of the proposed actinide compounds and their lanthanide analogs.

Professors Liddick and Spyrou from Michigan State University (MSU) will collaborate with the research teams at the University of Olso, Norway, Lawrence Livermore National Laboratory (LLNL), and Los Alamos National Laboratory (LANL) with the specific objective to use a new method to infer neutron capture, (n,γ), cross sections on short-lived isotopes. The technique will be applied to nuclei of interest for both stockpile stewardship and astrophysics at both FRIB and ANL. The project will also strengthen the connection between young researchers in university-based nuclear science programs and staff at the national laboratories. Students and postdoctoral researchers trained in nuclear science techniques will be exposed to national security problems and will spend extended periods of time at the national laboratories interacting with laboratory personnel.

The experimental objectives are to provide high-accuracy cross section measurements of 14N(n, p), 15N(n,p), 10Be(α,n)13C, and 35Cl(n,p). The neutron-induced reactions will lead to better modeling in applications such as neutron economy and transport through the fuel of nuclear reactors. The 10Be(α,n)13C cross section measurements are important for understanding the astrophysical origin of Be and B isotopes. The object of the data evaluation research is to develop more reliable evaluation procedures and to better understand the model uncertainties in data evaluation.

The primary objective of the proposed work is experimentally constraining statistical quantities such as nuclear level densities (NLD), γ-strength functions (γSF), and optical model potentials (OMPs), which are key inputs in the Hauser Feshbach (HF) calculations used for reaction cross sections. Despite the fact that reaction cross sections on fission fragments play a vital role across a wide range of applications, their theoretical interpretation and experimental constraints are still not fully understood. Experimentally constrained NLDs and γSFs are therefore indispensable for determining reaction cross sections near and far from stability in such areas as stockpile stewardship, nuclear data evaluations, high density plasma environments, reactor physics, and astrophysics. The secondary objective is to develop experimental techniques and computational models, and to train the next generation of nuclear scientists involving them in the NNSA enterprise by creating a pipeline to national laboratories. Students and postdoctoral researchers funded by the proposed work will travel to external facilities for experiments and gain invaluable experiences with our laboratory partners.

In recent explosive tests at the DOE/NNSA, clouds of micrometer cerium particles have been observed ejected into hydrogen environments where they react on microsecond timescales. Current models of the fundamental cerium hydride particle reactions are highly speculative, and predicted radiative temperatures do not match measured values. This project proposes to close knowledge gaps via the first-ever experimental observations of individual cerium particles reacting in hydrogen gas. Spatially fixed particles will be investigated with unique electrodynamic levitation and Joule heated wire configurations. Evolving particle sizes and hydride crust dynamics will be captured with MHz rate microscopy. Concurrently, particle temperatures will be quantified with multi-spectral pyrometry, and gas-phase thermal boundary layers will be measured with advanced laser spectroscopic diagnostics. The combined experimental results will be used to validate current models and derive model improvements to capture observed experimental behavior.

Metal additive manufacturing (AM) offers new opportunities to enhance component performance by customizing parts for their relevant use cases. With layer-by-layer printing of complex parts, AM can create functionally graded materials (FGMs) that continuously transform from one element to another – generating regionally-varied properties fit to the functional requirements. Despite its immense opportunity, metal AM’s implementation is limited by the significant performance variability due to the rapidly evolving harsh environments that transform and degrade materials in ways that we struggle to control. Fundamental studies reveal complex multi-physics trends that are difficult to reconcile, but for the full versatility of LPBF to be exploited, we require new operando X-ray diagnostics. This SSAA project is developing a new class of operando multiscale X-ray microscopes to directly map critical science required for reliable metal-AM – focusing on laser powder bed fusion (LPBF). The previous SSAA award developed the first nanoscale operando imaging of LPBF and directly revealed defect formation mechanisms not previously understood. The objective of the present proposal is to use and develop the novel microscopes to study the alloy mixing behaviors of in-situ alloying required for FGMs. The novel nano- and microscale microscopes will quantify the initial driving forces for Al-Cu mixing dynamics originating from a mixture of pure elemental powders. They will then directly measure the 3D flow dynamics in-situ for the first time by developing the operando Limited View Tomography (LVT) of LPBF. By establishing a suite of time-resolved 2D and 3D X-ray microscopes with analysis methods to track statistical dynamics, the new experimental “toolbox” will connect the complex multi-phase dynamics native to the extreme conditions of LPBF to solve open challenges for FGMs.

The goal of this proposal is to use correlated neutron-high-resolution γ-ray data to improve knowledge of (n,xn’γ) reaction cross sections on nuclides of interest to stewardship science. The program will utilize the Gamma Energy Neutron Energy Spectrometer for Inelastic Scattering (GENESIS) array at the LBNL 88-Inch cyclotron to perform the first-ever neutron-high-resolution gamma coincident measurements on the nuclei of interest. They will utilize the intense thick target deuteron break-up neutron source at the Lawrence Berkeley National Laboratory 88-Inch cyclotron to cover the entire energy range of interest to stockpile stewardship while simultaneously allowing for energy-integral validation measurements of non-elastic channels via post-irradiation activation. Two graduate students working with the members of the Bay Area Nuclear Data group and a staff scientist from LLNL will lead in the analysis of the data from these experiments. They will then work with reaction and fission modeling experts at LANL and LLNL to iteratively produce modeled correlated events that will be propagated through a benchmarked simulation of GENESIS and compared to measured data. The variance between the measured and modeled data response will then be used to provide a self-consistent measurement set of cross sections that are well-suited to the production of a new reaction and fission evaluations. This combined measurement+theory “forward modeling” approach was pioneered in the thesis of recent UCB graduate Joseph Gordon. The project will include completion of the analysis/interpretation of a bismuth data set taken in year 3 of the current proposal and then perform a new campaign of measurements on the fissionable nucleus 238U.

The objectives of this project are (1) to investigate the behavior of matter under extreme conditions of pressure, temperature, and magnetic field, (2) to obtain a greater understanding of the physics of d- and, particularly, f-electron materials, and (3) to train the next generation of scientists in the performance of technically demanding static high-pressure experiments for the purpose of studying matter under extreme conditions. The study of the effect of high-pressure on the properties of d- and f-electron materials constitutes the core of the research outlined in this proposal and the training under this program is in support of Stockpile Stewardship.

238Pu is in high demand for its ability to generate heat effectively (570 W/kg), sustain it over extended periods (t1/2=88y), and emits minimal radiation (there is no hard γ-radiation). These properties have led to significant market growth driven by various countries’ ambitious plans to develop isolated regions on Earth and in space. 238Pu can be produced via the irradiation of 237Np targets. The Pu separation from Np can be achieved using solvent extraction with tributyl phosphate (TBP), owing to decades of experience with PUREX processing of nuclear materials. Unfortunately, this separation process requires numerous extraction cycles to achieve efficiency, and a more effective extractant would accelerate the process. The newer neutral extractant di-1-methyl heptyl methyl phosphonate (DMHMP) promises to enhance actinide extractions. However, new chemical information is needed to confirm that DMHMP will efficiently separate Pu from Np targets. Our central hypothesis is that DMHMP is a superior extractant for Np/Pu separation compared to the commonly used ligands and will help facilitate 238Pu production. The goal of this research is to characterize the separation of Pu from an Np source using DMHMP through the quantification of Np III,IV,V, and VI and PuIII,IV,V, and VI extraction by DMHMP using radiochemical, spectroscopic, and computational techniques. Our specific objectives are A. Quantify the distribution coefficients of Np III,IV,V, and VI and Pu III,IV,V, and VI by DMHMP from HNO3 solutions; B. Determine the stoichiometry of Np and Pu extraction reactions and the coordination of Np/Pu-DMHMP complexes; C. Quantify the thermodynamic parameters associated with the extraction of Np and Pu; D. Train artificial intelligence (AI) algorithms to predict Np/Pu thermodynamics.

The goal of this project is to develop and implement innovative solution combustion synthesis (SCS) methods for preparing highly radioactive plutonium (Pu) and americium (Am) targets, which are essential for nuclear science measurements. The central hypothesis is that the self-generated heat during rapid SCS can produce robust radioactive targets more effectively than traditional methods. To address technical challenges such as the complexities and stabilities of Pu and Am oxides at the nanoscale and the scarcity of isotopically pure Pu and Am, extensive investigations will be conducted using surrogate materials, complemented by molecular dynamics (MD) simulations and machine learning (ML) methods. The research objectives include investigating high-throughput SCS reactions of surrogate and actinide oxides, conducting atomistic simulations to understand SCS mechanisms, and using ML to optimize synthesis conditions. Additionally, the project aims to prepare and characterize thin film targets and educate a student body to strengthen the workforce pipeline to national laboratories. This project will leverage advanced scientific instrumentation and facilities at the University of Notre Dame to achieve its goals.

Nuclear reaction cross sections are integral to a complete understanding of stellar nucleosynthesis, nuclear-energy applications, and national security concerns. Of particular interest to these fields are photodisintegration and radiative capture reactions involving neutrons. Within this project, a direct measurement of the (n, γ) reaction cross sections on 90Zr at energies where a statistical model approach is valid will be performed using the dance array. The goal of this work is to provide a benchmark for the recent surrogate method work. A new technique utilizing particle-absorption reactions that has been developed by the pi under the current nnsa award for an indirect measurement of the (n, γ) cross section will be utilized to continue indirect measurements of n-capture reactions. The technique will be employed to indirectly determine the (n, γ) cross sections via simultaneous measurement of (p, γ) and (p, n) reactions. The project will also explore the possibility of measuring the (α, n) reactions near the n-emission threshold using the summing detector, and the further use of those measurements to constrain (n, γ) cross sections. The summing technique will also be used to constrain the statistical properties of 91Nb via the multi-step cascade (msc) analysis method. The results of this work will allow for better constraint of the 90Nb(n, γ)91Nb reaction and will shed light on the statistical properties of nuclei in the A≈90 mass region. The impact of the current award and the work proposed here on the modeling of the nucleosynthesis s- and p-processes will be investigated through network calculations. Abundance flows will be modeled to understand the mechanisms of production of heavy nuclei in various stellar environments.

The University of Rochester proposes a concerted experimental and numerical effort to furnish a holistic description of the physics of laser-driven collapsing foams in ICF targets and establish how they can be simulated with high-enough fidelity to enable ICF foam-based designs. The project aims to (i) shed light on the dynamics of foam implosions, (ii) study the emergence and development of microturbulence, (iii) characterize transport processes (viz., heat conduction and viscosity), and (iv) assess the limitations of foam equations of state (EOS) and opacities. The specific research questions addressed by this project include: (1) Is there an effective EOS that can be used to model foams through the different implosion phases without capturing the microstructure? How is the opacity of low-Z foams altered by the microstructure if radiation transport is modeled with flux-limited multi-group diffusion? (2) Since turbulence is seeded as soon as the first shock goes through the foam, what happens to the turbulent kinetic energy when the foam is adiabatically compressed and during convergence and stagnation, when kinetic energy is converted into internal energy? Is the turbulent kinetic energy a major channel of energy transfer that takes energy away from the internal energy of the imploded core? (3) Does the intrinsic nonuniformity of foam seed hydrodynamic instabilities or is the wavelength so short that the seeded modes are ablatively stabilized?

This project will address one of the outstanding challenges in dynamic compression science: achieving a fundamental understanding of solid-liquid phase transitions at extreme pressures and temperatures. Motivated by outstanding scientific challenges and new opportunities opened up by dynamic compression experiments and MD simulations, they propose an innovative research program that will address two key questions: How do solids melt or liquids crystallize under dynamic compression, and what is the atomic structure and properties of hot-dense liquids? They will investigate: (1) the orientation-dependent non-equilibrium and time-dependent shock melting of SiC and diamond by a combination of predicting MD simulations and experiments at Omega EP and NIF; (2) metastable supercooled carbon liquid and to study crystallization of kinetically frustrated BC8 post-diamond phase of carbon; 3) the atomic structure of hot dense carbon and SiC liquids using predictive MD simulations, specifically focusing on unusual phenomena, such as pressure-dependent atomic restructuring including potential dissociation of extended bonding networks, liquid-liquid phase transitions and resulting changes in the physical properties, such as heat capacity and viscosity. The scientific goals of this project are: • Determine fundamental mechanisms of non-equilibrium orientation-dependent shock melting of diamond and SiC • Investigate metastable supercooled carbon liquid and study crystallization of diamond and kinetically frustrated BC8 post-diamond phase of carbon • Uncover complex behavior of hot, dense carbon and SiC liquids at extreme pressures and temperatures The broader impact objectives of the project are: • Provide unique experience for graduate student and postdoctoral associate to work together with NNSA collaborators during on-site summer practica and during experiments at national and international user facilities. • Strengthen on-going and highly productive collaboration with NNSA scientists by devising innovative theory-inspired experiments and executing them at national and international user facilities

The primary project objective is to investigate experimentally the beta-delayed neutron emission and inform nuclear models with the experimental results. This includes investigations of beta-decay strength distribution for the nuclei with large neutron excess large beta-decay energies, and small neutron separation energies with a particular focus on the fission fragments. The recent results show a dual nature of the process of neutron emission from excited states populated in beta decay. In many cases, the statistical nature consistent with the decay of the structureless system was observed; in a few cases, strong departures from this model were observed. This observation will have long-ranging consequences, and they propose to continue to investigate this for a larger group of isotopes and explore neutron emission systematically. The University of Tennessee will also attempt to study beta-delayed two-neutron emission. Knowledge of the beta-delayed neutron data is of interest to various nuclear science communities and connects to Stewardship Science and reactor physics. Students and postdocs' involvement in developing detectors and designing experiments provides them with exposure and training in cutting-edge experimental methods.

This project will advance artificial intelligence (AI) and physics-informed machine learning (PIML) technologies to enable modeling structure-property-performance (SPP) linkages in multi-phase, heterogeneous energetic compounds. Relative to the stockpile stewardship mission of NNSA, the sensitivity and performance of energetic materials are determined by microstructural features—relative arrangements and fractional volumes of components such as crystals, binder, inclusions, and defects. Under shock or impact loading, either intentional or accidental, energetic materials exhibit complex patterns of deformations and energy localizations in microstructures, exhibiting sharply evolving temperature and pressure fields and reaction fronts. Technical challenges arise in that, to model the reactive mechanics of energetic composites, a PIML-based AI model must contend with mathematical and computational challenges due to intricate interactions among heterogeneous material constituents under extreme pressure, temperature, and stress. To address these challenges, the study team has pioneered a suite of AI technologies, including physics-aware recurrent convolutions (PARC), to model the reactive dynamics of energetic materials, which was successfully validated on pressed Class V HMX explosives. However, the current state of the art is limited to relatively simple single-phase, homogeneous energetic mixtures (e.g., HMX crystals and voids alone). In contrast, energetic materials in real-world DOE/NNSA applications are often multi-phase (crystals, voids, binders, metal additives, etc.) and heterogeneous mixture of energetic crystals (e.g., CL-20/HMX cocrystals; HMX/TATB, etc.), rendering a variety of mathematical, computational, and data scientific challenges. This project will address such a gap in the current body of knowledge and deliver an AI-based framework to discover SPP relationships in multiphase heterogeneous energetic mixtures.

This study is to investigate the crystallization, chemistry and structure arising from complex interfaces of quantum mixtures (QM: mixtures of H2, He and other light molecules such as C, N2, O2, CO2, and H2O under high pressure-temperature (PT) conditions and gain fundamental insights into novel pressure-regulated crystallization of QM, unusual chemical reaction in inert QM, and novel conducting states and phase behaviors of quantum fluids mixtures (QFM). The emphasis of the proposed research will be on probing time-evolution of chemical bonding and metastable structures of highly diffusive quantum interfaces, utilizing state of the art dynamic-diamond anvil cell (d-DAC) and dynamic precompression experiments, coupled with time-resolved Raman spectroscopy, high-speed microscopy, and time-resolved x-ray diffraction at advanced 3rd and 4th generation light sources. The present work will also develop high PT technologies needed for fundamental research in NNSA’s stockpile stewardship program, generate fundamental data and knowledge that will benefit NNSA’s PSAAP, and provide exceptional education and training opportunities for graduate students for future workforce at the NNSA laboratories.