Focus Area 1: Advancing understanding of millimeter gap vacuum power flow to maximize coupled energy
Why is this important?
Pulsed power drivers are highly efficient at transferring energy to their targets, typically coupling over 90% of the current and more than 80% of the energy. However, achieving 100% efficiency is limited by the ability to direct Poynting flux effectively through anode-cathode (AK) gaps. Optimizing the AK gap distance is critical: smaller gaps reduce impedance but risk being dominated by gap plasmas, which disrupt Poynting flux flow. Each millimeter reduction in a power feed gap can have significant (e.g. 10%) increased power coupling efficiency.
Advanced diagnostics are crucial to achieving high-resolution, statistically significant measurements in pulsed magnetic systems. These diagnostics enable more accurate modeling, inform experimental designs, and accelerate understanding of critical power flow processes. They also reduce facility dependency and encourage collaboration, broadening the application of high-precision measurement tools.
What gaps will the new pilot uniquely close?
The pilot program will address several critical challenges, including:
- Developing advanced diagnostic tools to measure current and voltage at millimeter and sub millimeter distances from the Z axis, overcoming long-standing measurement limitations
- Enabling the deployment of gated XUV/x-ray spectrometers, X-ray diffraction (XRD) systems, two-color interferometry, fast bolometers, and complete optical systems such as Photon Doppler Velocimetry (PDV) and fiber-based Faraday systems for precise velocity and magnetic field measurements.
- Facilitating innovative measurement techniques to analyze power flow dynamics with unprecedented detail, including gated spectrometers for time-resolved analysis and hydrogen spectral line diagnostics for plasma characterization.
Focus Area 2: Millimeter-scale high velocity stability control to increase plasma energy density at low drive energy
Why is this important?
Achieving stable high-velocity plasma flow at the millimeter scale is essential for increasing plasma energy density without requiring excessive drive energy. Stability at these scales is critical for precise control of plasma behavior, ensuring consistent energy delivery and enhancing experimental reproducibility. Advancing our understanding and control of instabilities in millimeter-scale plasmas can enable breakthroughs in applications such as high-energy-density physics, inertial confinement fusion, and advanced materials research.
Controlling instabilities at such small scales requires both innovative engineering solutions and advanced diagnostic techniques capable of resolving rapid changes in plasma velocity and density. This is particularly important for optimizing plasma compression and energy transfer while minimizing energy losses due to turbulence or instability.
What gaps will the new pilot uniquely close?
The pilot program will address key challenges in high-velocity stability control by:
- Developing and validating models for plasma behavior at millimeter scales to predict and mitigate or exploit instabilities.
- Enhancing diagnostic capabilities to resolve plasma velocity, density, and other key parameters in real time.
- Implementing innovative plasma shaping techniques to achieve stable compression and higher energy densities with lower drive energies.
- Designing fast-response systems to adjust experimental parameters dynamically, ensuring stability across a wide range of conditions.
Focus Area 3: Statistically Significant Measurements of Material Constitutive Properties (“Microphysics”) to Inform and Improve Advanced Modeling Techniques
Why is this important?
Understanding the constitutive properties of materials at small scales is critical for advancing conductivity tables and other data sets essential to high-fidelity modeling. These properties underpin simulations and predictions for high-energy-density physics and national security applications. Generating statistically significant measurements is necessary to reduce uncertainties and improve the predictive power of advanced models.
Developing small-scale conductivity tables, for example, would provide a much-needed foundation for simulations that support applications such as high-throughput experiments at NNSA facilities. Achieving this level of detail requires a high-repetition-rate approach to collect robust data across a wide range of experimental conditions.
What gaps will the new pilot uniquely close?
The pilot program will address several critical challenges:
- High Repetition Rates: Implementing systems capable of achieving the necessary rep-rates for generating comprehensive material property tables, enabling statistically significant data collection.
- Technology Development for High-Throughput Systems: Advancing technologies required for future NNSA facilities, including:
- Target Fabrication and Installation: Designing scalable processes for producing and integrating precision experimental targets.
- Charging and Switching Technologies: Developing robust, efficient systems to support rapid experimentation cycles.
- Integration of Experimental Systems: Establishing platforms that combine high throughput with precision diagnostics, enabling continuous data generation and processing.
