Pulsed Power as a Science: Predictive Simulations for Beams, Z-Pinches, and Other Applications

This article is based on my plenary presentation that was associated with my Peter Haas Award, where I overview my 40 years of research and the people with whom I have had the pleasure of working, both domestically and internationally. In 1978, Sandia's electron beam fusion program emerged from a weapons simulator community that was machine oriented and relied on design principles and J. Charlie Martin (JCM) criteria. The simulation tools were primarily used retrospectively. Fusions' extraordinary requirements stimulated tremendous innovation in pulsed power, beams, pinches, and simulation tools. I started by developing ion beam deposition and transport models that were integrated into radiation-hydrodynamics codes; validated by experiments on Gamble II and Proto I; and helped initiate Sandia's light-ion-beam fusion program. Strategic Defense Initiative (SDI) program research led to the development of the Integrated Tiger Series (ITS) suite of electron-photon Monte Carlo codes (1985). A research on Particle Beam Fusion Accelerator I (PBFA-I) and PBFA-II on generating, transporting, and focusing ion beams required developing transport, diagnostic simulation, and analysis tools, which were used in focusing protons to 5 TW/cm
²
(1991) and lithium beams to 2 TW/cm
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and heating hohlraums to 65 eV (1996). They also helped identify anode plasma formation by electron heating as the source of diode impedance collapse leading to efforts to include electron-electrode interaction models into particle-in-cell (PIC) codes and initiating hybrid fluid-PIC development (IPROP, LSP). Electrode physics remains a power flow grand challenge for high-yield fusion. In 1999, I led rad-magnetohydrodynamic (MHD) development [arbitrary-Lagrangian-Eulerian general research applications high-energy-density physics (ALEGRA-HEDP)] and oversaw equation of state (EOS) and conductivity model development using quantum molecular dynamics/density function theory (QMD/DFT), resulting in predictive capabilities for dynamic material experiments. Improved z-pinch dynamic hohlraum modeling and experiments resulted in thermonuclear neutrons (2004). 3-D wire array dynamics were modeled and understood. We developed advanced radiographic sources and built a linear transformer driver (LTD) test bed. At the Naval Research Laboratory (NRL), I have overseen advances in modeling and experiments in beams, pinches, pulsed power, and their applications (2009-). My goal throughout has been to develop and validate predictive simulation tools, making pulsed power a Science.