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arXiv · 2006.01401

Implementing a microphysics model in hydrodynamic simulations to study the initial plasma formation in dielectric ablator materials for direct-drive implosions

Arnab Kar·S. X. Hu·G. Duchateau·J. Carroll-Nellenback·P. B. Radha
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Abstract

A microphysics model to describe the photoionization and impact ionization processes in dielectric ablator materials like plastic has been implemented into the one-dimensional hydrodynamic code LILAC for planar and spherical targets. At present, the initial plasma formation during the early stages of a laser drive is modeled in an ad hoc manner, until the formation of a critical surface. Implementation of the physics-based models predicts higher values of electron temperature and pressure than the ad hoc model. Moreover, the numerical predictions are consistent with previous experimental observations of the shine-through mechanism in plastic ablators. For planar targets, a decompression of the rear end of the target was observed that is similar to recent experiments. An application of this model is to understand the laser-imprint mechanism that is caused by nonuniform laser irradiation due to a single beam speckle.

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Arnab Kar, S. X. Hu, G. Duchateau, J. Carroll-Nellenback, P. B. Radha. 2020-06-02. Implementing a microphysics model in hydrodynamic simulations to study the initial plasma formation in dielectric ablator materials for direct-drive implosions. https://doi.org/10.1103/physreve.101.063202

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