TA-53 Accelerator Site
The Nation’s ability to certify the stockpile without nuclear testing relies on expert judgment informed by simulation of past nuclear tests and the ongoing Stockpile Stewardship Program. A key part of this program focuses on the behavior of weapons materials under all weapons conditions. Today, simulations of weapons materials lack the ability to represent micro- and mesoscale phenomena because of gaps in our fundamental understanding. This leaves uncertainty about how specific materials will perform, even when the atomic-scale structure is known. To mitigate uncertainty, additional performance margin must be included. In the case of manufacture, it leaves an inability to predict how processing affects microstructure and ultimately, integrated performance.
Today’s stockpile is subject to several pressures. Each of these pressures demands a high-confidence predictive response to changes that might be required of the stockpile. There are an unprecedented number of warhead life-extensions in which aging and obsolescence will dictate component replacement and material substitution. The New-START reduction in the number of active stockpile warheads, when combined with drivers that favor a smaller inactive stockpile, demand improved confidence in our ability to predict performance. Safety considerations are prompting the incorporation of insensitive high explosive (IHE) throughout the stockpile. The desire for common components and interoperability across systems places a higher burden on confident prediction of a less diverse stockpile.
The MPDH will be a user facility capable of creating dynamic extremes and diagnosing material behavior and performance over a wide range of scales. By providing simultaneous photon, proton, and electron probes interior to the material of interest—in particular tracking the transient evolution of the stress and strain or granular motion throughout the region of interest—MPDH will provide the detailed information required by fundamental theories of dynamic material behavior to predict bulk performance.
The MaRIE 1.0 MPDH provides a unique capability for simultaneous, multi-probe measurements of in situ transient phenomena in relevant dynamic extremes. MaRIE 1.0 will be the only very-hard XFEL (42-keV fundamental) capable of penetrating multigranular high-Z samples (compared to LCLS/LCLS II at 8 keV/13 keV and EXFEL at 15–20 keV). MaRIE 1.0 will be designed to allow multiple x-ray pulses over the nanosecond time scales of shock transit of grains, and thus a higher repetition frequency than Linac Coherent Light Source (LCLS) (120 Hz) or the European X-ray Free-Electron Laser (XFEL), European X-ray Free-Electron Laser (EXFEL) (5 MHz). Compared to any other light source in the world, whether an X-ray Free-Electron Laser (XFEL) or synchrotron, only MaRIE 1.0 will allow simultaneous x-ray scattering with proton radiography; and only MaRIE 1.0 will use the associated electron beam for high space and time resolution electron radiography. Compared to high-energy-density science facilities for dynamic materials (such as National Ignition Facility (NIF) or Z), MaRIE 1.0 will also feature multiple diagnostics of the material state and will have the highest-quality x-ray beam. The stress range of the dynamic extremes provided by MaRIE 1.0 will not be as large as some facilities, but the flexibility of choosing loading paths in pressure-density space will be unique. Finally, MPDH will allow experiments on the full range of materials of interest, up to and including plutonium.
The M4 will provide a user facility with integrated capabilities for predicting, controlling, and characterizing material properties at the mesoscale. Predictive simulation across scales that can relate bulk performance to meso- and microscale chemical and structural properties is a central feature of the Dynamic Materials Performance “First Experiments.” Success from a facility perspective necessitates an integrated approach in which modeling, making, and measuring are closely coupled. “Modeling” must integrate theory, modeling, and computation with experiment through co-design.
The MaRIE 1.0 M4 Facility provides unique collocated and integrated synthesis, characterization, and co-design capabilities for controlling material properties at the mesoscale. The need for integrated facilities to solve challenging multiscale problems is being realized across the country. Success at the nano length scale has been realized in the semiconductor industry and at MESA, as well as through DOE’s Nanoscience Research Centers. Facilities such as the Energy Sciences Facility at ANL are currently being constructed to address mesoscale challenges of advanced energy materials through integration of existing capabilities. No such facility exists either with M4’s unique synthesis and characterization capabilities or for weapons materials with the appropriate authorization basis and security requirements.