The National Ignition Facility: Ushering in a new age for high energy density science

Abstract

The National Ignition Facility (NIF) [E. I. Moses, J. Phys.: Conf. Ser. 112, 012003 (2008); https://lasers.llnl.gov/], completed in March 2009, is the highest energy laser ever constructed. The high temperatures and densities achievable at NIF will enable a number of experiments in inertial confinement fusion and stockpile stewardship, as well as access to new regimes in a variety of experiments relevant to x-ray astronomy, laser-plasma interactions, hydrodynamic instabilities, nuclear astrophysics, and planetary science. The experiments will impact research on black holes and other accreting objects, the understanding of stellar evolution and explosions, nuclear reactions in dense plasmas relevant to stellar nucleosynthesis, properties of warm dense matter in planetary interiors, molecular cloud dynamics and star formation, and fusion energy generation.

Molecular dynamics studies of electron-ion temperature equilibration in hydrogen plasmas within the coupled-mode regime

“…It is in this sense that a description of the collision rate in terms of a Coulomb-logarithm, ln λ ei = ln (b max /b min ), is sensible, where the maximum impact parameter, b max , is identified with the static electron-only Debye length. Such simplifications in turn form the basis for analytic in-line models of electron-ion T -equilibration widely used in ICF simulation codes [1,2].…”

“…The phenomenon of electron-ion temperature equilibration is important for the study of inertial confinement fusion (ICF), since the asymmetric manner in which α-particle fusion products deposit energy naturally creates such a temperature-split (T -split) at certain key regions and times within an imploding capsule [1,2]. While much of the ICF capsule material is DT, the 50-50 mixture of deuterium and tritium, the presence of an outer, so-called, ablator layer in such capsules creates the possibility of admixture of higher-Z (ionic charge) elements (C, Be, and/or dopants like Ge and W) into the DT fuel.…”

Capsule modeling of high foot implosion experiments on the National Ignition Facility

“…What is the state of 'understanding' of indirect drive inertial confinement fusion (ICF) implosion experiments on the National Ignition Facility (NIF) [1]? Do the experiments agree with expectations based on the known experimental conditions, or are there discrepancies to suggest that the current physical picture of these implosions is incomplete?…”

Hydrodynamic instability experiments with three-dimensional modulations at the National Ignition Facility

“…Hydrodynamic instabilities (including Rayleigh-Taylor and Richtmyer-Meshkov instabilities) and mix play a central role in the performance degradation of spherical implosions in ICF [2,3] . In recent high-compression experiments at the National Ignition Facility (NIF) [4] , the highest fuel areal densities (ρ R) were achieved in implosions with ignitionrelevant implosion velocities [5,6] . These key performance parameters were close to the goal of the ignition point design [7] , but the neutron yields were significantly reduced from expectations [5,6] .…”