Pulsed-power-driven high energy density physics and inertial confinement fusion research

TLDR

The Z accelerator at Sandia National Laboratories delivers ~20 MA load currents, generating magnetic fields exceeding 1000 T and megabar‑to‑gigabar pressures for high‑energy‑density physics and inertial confinement fusion research. The project aims to upgrade the Z accelerator over five years, targeting nearly 3 MJ x‑ray output at >300 TW by 2007. Using a z‑pinch configuration, the Z accelerator’s magnetic pressure supersonically implodes a wire‑array plasma to achieve ~10 MJ cm⁻³ energy densities and >1 keV temperatures, while alternative setups drive isentropic compression to >3 Mbar and accelerate flyer plates to >30 km s⁻¹ for EOS studies, with research conducted in collaboration worldwide. The Z accelerator produces ~2 MJ x‑ray energies at >200 TW, enabling ICF capsule implosions with improved symmetry and neutron yield, and a range of HEDP experiments such as radiation‑driven jets, EOS up to 10 Mbar, phase transitions, material strength studies, and detailed z‑pinch wire‑array dynamics, supported by advanced radiation‑magnetohydrodynamic simulations.

Abstract

The Z accelerator [R. B. Spielman, W. A. Stygar, J. F. Seamen et al., Proceedings of the 11th International Pulsed Power Conference, Baltimore, MD, 1997, edited by G. Cooperstein and I. Vitkovitsky (IEEE, Piscataway, NJ, 1997), Vol. 1, p. 709] at Sandia National Laboratories delivers ∼20MA load currents to create high magnetic fields (>1000T) and high pressures (megabar to gigabar). In a z-pinch configuration, the magnetic pressure (the Lorentz force) supersonically implodes a plasma created from a cylindrical wire array, which at stagnation typically generates a plasma with energy densities of about 10MJ∕cm3 and temperatures >1keV at 0.1% of solid density. These plasmas produce x-ray energies approaching 2MJ at powers >200TW for inertial confinement fusion (ICF) and high energy density physics (HEDP) experiments. In an alternative configuration, the large magnetic pressure directly drives isentropic compression experiments to pressures >3Mbar and accelerates flyer plates to >30km∕s for equation of state (EOS) experiments at pressures up to 10Mbar in aluminum. Development of multidimensional radiation-magnetohydrodynamic codes, coupled with more accurate material models (e.g., quantum molecular dynamics calculations with density functional theory), has produced synergy between validating the simulations and guiding the experiments. Z is now routinely used to drive ICF capsule implosions (focusing on implosion symmetry and neutron production) and to perform HEDP experiments (including radiation-driven hydrodynamic jets, EOS, phase transitions, strength of materials, and detailed behavior of z-pinch wire-array initiation and implosion). This research is performed in collaboration with many other groups from around the world. A five year project to enhance the capability and precision of Z, to be completed in 2007, will result in x-ray energies of nearly 3MJ at x-ray powers >300TW.