National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

Pressure Gradient Effects On Two-Dimensional Plasma Expansion.

DE200515014567

Publication Date	2004
Personal Author	Moon, S.; Smith, R. F.; Dunn, J.; Keenan, R.; Nilsen, J.; Hunter, J. R.; Filevich, J.; Rocca, J. J.; Marconi, M. C.; Shlyaptsev, V. N.
Page Count	10
Abstract	The electron density evolution of a laser-heated Al plasma is measured using a diffraction grating interferometer (DGI) at different times, relative to the peak of a 600ps plasma forming pulse. This gives an effective moving picture of how the plasma evolves in space and in time. The experimental results show pronounced two dimensional effects such as significant lateral transport and an on-axis density dip. We use 2-D hydrodynamic simulations in order to calculate the contributions of various physical mechanisms driving the plasma expansion. Density depressions have been observed before for high intensities laser drivers (pondermotive force) and for lower intensities were the pumping pulse lasts for several nanoseconds (coronal x-ray ray heating). For the plasma conditions explored here, simulations suggest that the on-axis density dip can be explained by rapid movement of material laterally due to the large pressure gradients set up by the tightly focused laser beam.
Keywords	Plasma density Pressure gradients Interferometry Electron density X-ray lasers Laser beams Irradiation Diffraction Two dimensional Simulations
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200607

Pressure Gradient Effects On Two-Dimensional Plasma Expansion.

Pressure Gradient Effects On Two-Dimensional Plasma Expansion.
DE200515014567

Publication Date	2004
Personal Author	Moon, S.; Smith, R. F.; Dunn, J.; Keenan, R.; Nilsen, J.; Hunter, J. R.; Filevich, J.; Rocca, J. J.; Marconi, M. C.; Shlyaptsev, V. N.
Page Count	10
Abstract	The electron density evolution of a laser-heated Al plasma is measured using a diffraction grating interferometer (DGI) at different times, relative to the peak of a 600ps plasma forming pulse. This gives an effective moving picture of how the plasma evolves in space and in time. The experimental results show pronounced two dimensional effects such as significant lateral transport and an on-axis density dip. We use 2-D hydrodynamic simulations in order to calculate the contributions of various physical mechanisms driving the plasma expansion. Density depressions have been observed before for high intensities laser drivers (pondermotive force) and for lower intensities were the pumping pulse lasts for several nanoseconds (coronal x-ray ray heating). For the plasma conditions explored here, simulations suggest that the on-axis density dip can be explained by rapid movement of material laterally due to the large pressure gradients set up by the tightly focused laser beam.
Keywords	Plasma density Pressure gradients Interferometry Electron density X-ray lasers Laser beams Irradiation Diffraction Two dimensional Simulations
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200607