Thermal gradient effect on hydrogen transport in tungsten

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Alturk, Sanad, Jeffries, Jacob, Kose, Muhammed, Martinez, Enrique
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912739103866880
author Alturk, Sanad
Jeffries, Jacob
Kose, Muhammed
Martinez, Enrique
author_facet Alturk, Sanad
Jeffries, Jacob
Kose, Muhammed
Martinez, Enrique
contents One key challenge for efficiency and safety in fusion devices is the retention of tritium (T) in plasma-facing components. Tritium retention generates radioactive concerns and decreases the amount of fuel available to generate power. Hence, understanding the behavior of T in tungsten (W), as the main candidate as armor material, is critical to the deployment of fusion as a reliable energy source. In this work, we have studied the effect of a thermal gradient in the transport properties of hydrogen (as a T surrogate) in pure W. Strong thermal gradients develop in the divertor as a result of the intense energy fluxes arriving at the material. We have developed an analytical approach to compute the heat of transport ($Q^*$) that is parameterized from molecular dynamics (MD) simulations. $Q^*$ is a parameter needed in irreversible thermodynamics frameworks to understand mass transport in the presence of thermal gradients. We show that $Q^*$ can be written as a function of temperature, temperature gradient, a characteristic length and the ratio of the rates towards hot and cold regions. Furthermore, we describe how, to first order, the dependence of $Q^*$ on the thermal gradient vanishes, in agreement with MD results. On average, we find $Q^*=-5.41\times 10^{-3}kT^2~\text{eV}$ for H in pure W, with $k$ the Boltzmann constant and $T$ the temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2508_09169
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Thermal gradient effect on hydrogen transport in tungsten
Alturk, Sanad
Jeffries, Jacob
Kose, Muhammed
Martinez, Enrique
Materials Science
Plasma Physics
One key challenge for efficiency and safety in fusion devices is the retention of tritium (T) in plasma-facing components. Tritium retention generates radioactive concerns and decreases the amount of fuel available to generate power. Hence, understanding the behavior of T in tungsten (W), as the main candidate as armor material, is critical to the deployment of fusion as a reliable energy source. In this work, we have studied the effect of a thermal gradient in the transport properties of hydrogen (as a T surrogate) in pure W. Strong thermal gradients develop in the divertor as a result of the intense energy fluxes arriving at the material. We have developed an analytical approach to compute the heat of transport ($Q^*$) that is parameterized from molecular dynamics (MD) simulations. $Q^*$ is a parameter needed in irreversible thermodynamics frameworks to understand mass transport in the presence of thermal gradients. We show that $Q^*$ can be written as a function of temperature, temperature gradient, a characteristic length and the ratio of the rates towards hot and cold regions. Furthermore, we describe how, to first order, the dependence of $Q^*$ on the thermal gradient vanishes, in agreement with MD results. On average, we find $Q^*=-5.41\times 10^{-3}kT^2~\text{eV}$ for H in pure W, with $k$ the Boltzmann constant and $T$ the temperature.
title Thermal gradient effect on hydrogen transport in tungsten
topic Materials Science
Plasma Physics
url https://arxiv.org/abs/2508.09169