Center for Computational Physics Developments

Code 6440

The CCPD is responsible for the development and application of new computational techniques, algorithms, and diagnostics to problems of general interest. The primary areas of activity are in computational gasdynamics, laser plasma interaction, inertial confinement fusion, applications of Monotonic Lagrangian Grid (MLG) to particle codes, solar terrestrial interactions, astrophysics, and electromagnetic and acoustic scattering. Of major interest is the development of Massively Parallel Processing for Computational Fluid Dynamics and Computational Physics.

Research in Inertial Confinement Fusion

Research is directed to understand the basic physics in the design of high-gain direct drive Inertial Confinement Fusion (ICF) pellets. In this concept laser light is used to symmetrically implode a spherical pellet to sufficiently high densities and temperatures to achieve thermonuclear fusion. This requires very symmetric illumination and a stable hydrodynamic implosion. Two- and three-dimensional state-of-the-art radiation hydrodynamics codes are being developed and applied study the dynamics of both planar and spherical targets to provide better understanding of how to control the Rayleigh- Taylor instability. This project is part of a DOE program in the Plasma Physics Division where a new 5MJ laser facility with the worlds most uniform high powered laser has recently been brought on line. The results of experiments on that facility will be used to benchmark the codes and provide more confidence in pellet designs.

Research in Solar Activity and Heliospheric Dynamics

A major research effort is underway to exploit Massively Parallel Processing in developing a better understanding of the sun's behavior. In conjunction with the NASA HPCC program the "Science Grand Challenge: To understand the solar driving engine, the mechanism of solar activity and the dynamics of the heliosphere" has been undertaken. The range of scales necessary to model the sun spans several orders of magnitude requiring very large 3D numerical simulation codes using spectral, finite volume, and particle techniques developed to run on massively parallel computer systems. Solar activity is the underlying driver for many of the important phenomena in space physics. Some of the questions that will be address in this research program are: What photospheric magnetic and velocity fields lead to solar flares? Are prominence eruptions and coronal mass ejection due to a loss of equilibrium in a 3D magnetic field? The answers to these and other questions will help develop a predictive capability of phenomena having a direct impact on earth.

fig 1. Advanced computer models allow studies of perturbations well into the nonlinear regime. Simulations show that short (a) and long (c) wavelengths will not be harmful but intermediate (b) wavelengths need experimental evaluation.

fig 2. Isosurfaces of (Top) magnetic field magnitude and (bottom) electric current magnitude illustrating three stages in magnetic flux tube reconnection from numerical simulations using highly parallelized Fourier collocation algorithm on the NRL CM5E.

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Last modified: December 19, 1996

Laboratory for Computational Physics and Computational Physics /