The Role of Computing Technologies in Modeling Implosions in Inertial Confinement Fusion

Author: P. B. Radha (University of Rochester, Laboratory for Laser Energetics (LLE))

Abstract

Inertial Confinement Fusion (ICF) is one of the leading candidates for a power plant employing nuclear fusion as the energy source. In this approach, a pellet containing isotopes of hydrogen is imploded using nominally identical beams of a laser. Ignition is said to occur when more energy is released from the implosion than the incident energy of the laser. ICF requires the modeling of complex multidimensional fluid flows including the interaction of lasers with plasmas, heat conduction, radiation transport, and charged-particle transport in plasmas. In the typical approach to simulate these implosions hydrodynamic codes are used, that must include all these pieces of computationally intensive and inter-dependent physics. The assumption of spherical symmetry considerably eases the computational burden. However, realistic nonuniformities in the pellet and the driving laser need to be modeled to make predictions about ignition. Consequently, large-scale multidimensional simulations were considered impractical only a few years ago. Advances in computing, including the use of parallel computers have enabled vast improvements in the computational speed of such simulations. As a result, numerical simulations have been used to interpret experimental data and make detailed predictions for ignition. In this talk, a relatively new ICF-hydrodynamics code that exploits existing computing technologies such as tools for cross-platform development, parallel approaches to simulations and their post-processing will be described. The challenges imposed by these large-scale simulations on computing infrastructure at the LLE will be discussed. Finally, some of the physical insights gained from simulations and their impact on ignition will be discussed.

This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority. The support of DOE does not constitute an endorsement by DOE of the views expressed in this article.