Extend the random-walk shielding-potential viscosity model to hot temperature regime

TL;DR

This paper extends a viscosity model based on random-walk ions and Debye shielding to higher temperatures, enabling accurate shear viscosity calculations for various plasmas across a broad temperature and density range.

Contribution

The authors develop an extended random-walk shielding-potential viscosity model that applies to a wider temperature regime by reconsidering collision distances, improving shear viscosity predictions for one component plasmas.

Findings

Model accurately predicts shear viscosity for multiple elements.

Applicable across a wide temperature and density range.

Enhances previous low-temperature viscosity models.

Abstract

The transport properties of matter have been widely investigated. In particular, shear viscosity over a wide parameter space is crucial for various applications, such as designing inertial confinement fusion (ICF) targets and determining the Rayleigh-Taylor instability. In this work, an extended random-walk shielding-potential viscosity model (ext-RWSP-VM) based on the statistics of random-walk ions and the Debye shielding effect is proposed to elevate the temperature limit of RWSP-VM [Phys. Rev. E 106, 014142] in evaluating the shear viscosity of one component plasma. In the extended model, we reconsider the collision distance that is introduced by hard-sphere concept, hence, it is applicable in wide temperature regime rather than a narrower one in which RWSP-VM is applicable. The results of H, C, Al, Fe, Ge, W, and U show that the extended model provides a systematic way to calculate the shear viscosity of arbitrary one component plasma at the densities from about 0.1 to 10 times the normal density (the density at room temperature and 1 standard atmosphere). This work will help to develop viscosity model in wide regime when combined with our previous low temperature viscosity model [AIP Adv. 11, 015043].