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Title: Atomistic simulations of helium, hydrogen, and self-interstitial diffusion inside dislocation cores in tungsten

Abstract

Tritium retention and microstructural modifications due to helium accumulation are two of the main concerns regarding plasma-facing materials in fusion applications. Crystal defects in tungsten (W), such as grain boundaries and dislocations, can serve as traps or channels for diffusion of hydrogen (H) and helium (He), and, as such, can affect the transport of these species. In this work reported herein, we study the diffusion of hydrogen, helium and self-interstitial atoms (SIA) inside screw and edge dislocations in W using molecular dynamics simulations. Stable sites for interstitials in dislocations are identified using a free-volume analysis and energy barriers for diffusion are predicted using a combination of the nudged elastic band (NEB) method and finite temperature molecular dynamics simulations. Overall, the simulations predict higher energetic barriers for He and H diffusion in both screw and edge dislocations compared to the bulk. However, the diffusion mechanism in both dislocations are shown to differ: simulations predict that interstitials are constrained to move in short channels inside the edge dislocation core so that long-range diffusion along the dislocation line happens only with the motion of the dislocation. In contrast, 1D diffusion of the interstitial along the dislocation core, independent of dislocation motion, is observedmore » for screw dislocations.« less

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21). Scientific Discovery through Advanced Computing (SciDAC); USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1604004
Report Number(s):
[LA-UR-19-28989]
[Journal ID: ISSN 0029-5515]
Grant/Contract Number:  
[89233218CNA000001; SC0008875; AC02-05CH11231]
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
[ Journal Volume: 60; Journal Issue: 2]; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
dislocations; plasma facing materials; tungsten; interstitials; molecular dynamics; fusion reactor materials

Citation Formats

Mathew, Nithin, Perez, Danny, and Martinez Saez, Enrique. Atomistic simulations of helium, hydrogen, and self-interstitial diffusion inside dislocation cores in tungsten. United States: N. p., 2020. Web. doi:10.1088/1741-4326/ab6061.
Mathew, Nithin, Perez, Danny, & Martinez Saez, Enrique. Atomistic simulations of helium, hydrogen, and self-interstitial diffusion inside dislocation cores in tungsten. United States. doi:10.1088/1741-4326/ab6061.
Mathew, Nithin, Perez, Danny, and Martinez Saez, Enrique. Fri . "Atomistic simulations of helium, hydrogen, and self-interstitial diffusion inside dislocation cores in tungsten". United States. doi:10.1088/1741-4326/ab6061.
@article{osti_1604004,
title = {Atomistic simulations of helium, hydrogen, and self-interstitial diffusion inside dislocation cores in tungsten},
author = {Mathew, Nithin and Perez, Danny and Martinez Saez, Enrique},
abstractNote = {Tritium retention and microstructural modifications due to helium accumulation are two of the main concerns regarding plasma-facing materials in fusion applications. Crystal defects in tungsten (W), such as grain boundaries and dislocations, can serve as traps or channels for diffusion of hydrogen (H) and helium (He), and, as such, can affect the transport of these species. In this work reported herein, we study the diffusion of hydrogen, helium and self-interstitial atoms (SIA) inside screw and edge dislocations in W using molecular dynamics simulations. Stable sites for interstitials in dislocations are identified using a free-volume analysis and energy barriers for diffusion are predicted using a combination of the nudged elastic band (NEB) method and finite temperature molecular dynamics simulations. Overall, the simulations predict higher energetic barriers for He and H diffusion in both screw and edge dislocations compared to the bulk. However, the diffusion mechanism in both dislocations are shown to differ: simulations predict that interstitials are constrained to move in short channels inside the edge dislocation core so that long-range diffusion along the dislocation line happens only with the motion of the dislocation. In contrast, 1D diffusion of the interstitial along the dislocation core, independent of dislocation motion, is observed for screw dislocations.},
doi = {10.1088/1741-4326/ab6061},
journal = {Nuclear Fusion},
number = [2],
volume = [60],
place = {United States},
year = {2020},
month = {1}
}

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Works referenced in this record:

Hydrogen distribution induced screw dislocation core spreading in tungsten
journal, September 2019


Multiscale modelling of the interaction of hydrogen with interstitial defects and dislocations in BCC tungsten
journal, November 2017


H trapping and mobility in nanostructured tungsten grain boundaries: a combined experimental and theoretical approach
journal, September 2015


Formation mechanism of bubbles and holes on tungsten surface with low-energy and high-flux helium plasma irradiation in NAGDIS-II
journal, August 2004


Trapping of hydrogen and helium at dislocations in tungsten: an ab initio study
journal, October 2017


Theory and simulation of the diffusion of kinks on dislocations in bcc metals
journal, February 2013


The Use of Tungsten in Fusion Reactors: A Review of the Hydrogen Retention and Migration Properties
journal, January 2001


Hydrogen diffusion and trapping in nanocrystalline tungsten
journal, March 2015


Atomsk: A tool for manipulating and converting atomic data files
journal, December 2015


Influence of grain boundaries on the radiation-induced defects and hydrogen in nanostructured and coarse-grained tungsten
journal, January 2017


Dislocation mechanism of deuterium retention in tungsten under plasma implantation
journal, August 2014


Molecular dynamics study of melting and freezing of small Lennard-Jones clusters
journal, September 1987

  • Honeycutt, J. Dana.; Andersen, Hans C.
  • The Journal of Physical Chemistry, Vol. 91, Issue 19, p. 4950-4963
  • DOI: 10.1021/j100303a014

Low temperature diffusivity of self-interstitial defects in tungsten
journal, July 2017

  • Swinburne, Thomas D.; Ma, Pui-Wai; Dudarev, Sergei L.
  • New Journal of Physics, Vol. 19, Issue 7
  • DOI: 10.1088/1367-2630/aa78ea

Atomistic simulation of single kinks of screw dislocations in α-Fe
journal, April 2009


ITER overview
journal, April 1997


Analytical interatomic potential for modeling nonequilibrium processes in the W–C–H system
journal, December 2005

  • Juslin, N.; Erhart, P.; Träskelin, P.
  • Journal of Applied Physics, Vol. 98, Issue 12
  • DOI: 10.1063/1.2149492

Loop-punching suppression induced by growth of helium bubble pair in tungsten
journal, December 2018

  • Gao, N.; Cui, M. H.; Setyawan, W.
  • Journal of Applied Physics, Vol. 124, Issue 23
  • DOI: 10.1063/1.5053138

Fast Parallel Algorithms for Short-Range Molecular Dynamics
journal, March 1995


A computational method to identify interstitial sites in complex materials
journal, May 2008


Effect of interatomic potential on the energetics of hydrogen and helium-vacancy complexes in bulk, or near surfaces of tungsten
journal, December 2018


Trapping of hydrogen and helium at an {110}<111> edge dislocation in tungsten
journal, February 2017


New helium bubble growth mode at a symmetric grain-boundary in tungsten: accelerated molecular dynamics study
journal, July 2018


Hydrogen retention in plasma-facing materials and its consequences on tokamak operation
journal, February 1997


A climbing image nudged elastic band method for finding saddle points and minimum energy paths
journal, December 2000

  • Henkelman, Graeme; Uberuaga, Blas P.; Jónsson, Hannes
  • The Journal of Chemical Physics, Vol. 113, Issue 22, p. 9901-9904
  • DOI: 10.1063/1.1329672

Tritium retention in plasma facing components for NET/ITER fusion devices
journal, December 1991


In-Vessel Tritium Retention and Removal in ITER-FEAT
journal, January 2001


A triangulation-based method to identify dislocations in atomistic models
journal, October 2014


Theoretical evaluation of the role of crystal defects on local equilibrium and effective diffusivity of hydrogen in iron
journal, January 2017


Interatomic potentials for simulation of He bubble formation in W
journal, January 2013


Dynamics of Small Mobile Helium Clusters Near a Symmetric Tilt Grain Boundary of Plasma-Exposed Tungsten
journal, January 2017

  • Hu, Lin; Hammond, Karl D.; Wirth, Brian D.
  • Fusion Science and Technology, Vol. 71, Issue 1
  • DOI: 10.13182/FST16-105

Helium segregation and transport behavior near ⟨100⟩ and ⟨110⟩ symmetric tilt grain boundaries in tungsten
journal, June 2018

  • Yang, Zhuocen; Hu, Lin; Maroudas, Dimitrios
  • Journal of Applied Physics, Vol. 123, Issue 22
  • DOI: 10.1063/1.5026617

Dislocation climbing mechanism for helium bubble growth in tungsten
journal, April 2018


Dislocations mediate hydrogen retention in tungsten
journal, March 2014


Thermal stability of helium–vacancy clusters in iron
journal, April 2003

  • Morishita, K.; Sugano, R.; Wirth, B. D.
  • Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 202
  • DOI: 10.1016/S0168-583X(02)01832-3

Solution and Diffusion of Hydrogen in Tungsten
journal, May 1969

  • Frauenfelder, R.
  • Journal of Vacuum Science and Technology, Vol. 6, Issue 3
  • DOI: 10.1116/1.1492699

On the binding of nanometric hydrogen–helium clusters in tungsten
journal, October 2014


Interaction of hydrogen with dislocations in tungsten: An atomistic study
journal, October 2015


Incident ion energy dependence of bubble formation on tungsten surface with low energy and high flux helium plasma irradiation
journal, March 2003


“Conjugate Channeling” Effect in Dislocation Core Diffusion: Carbon Transport in Dislocated BCC Iron
journal, April 2013


A new interatomic potential function for helium
journal, January 1968


Interatomic potentials for modelling radiation defects and dislocations in tungsten
journal, September 2013


Many-body central force potentials for tungsten
journal, June 2014

  • Bonny, G.; Terentyev, D.; Bakaev, A.
  • Modelling and Simulation in Materials Science and Engineering, Vol. 22, Issue 5
  • DOI: 10.1088/0965-0393/22/5/053001

Slow diffusion of hydrogen at a screw dislocation core in α -iron
journal, July 2011


Helium, hydrogen, and fuzz in plasma-facing materials
journal, October 2017


Tritium retention in tungsten exposed to intense fluxes of 100 eV tritons
journal, March 1999


Improved tangent estimate in the nudged elastic band method for finding minimum energy paths and saddle points
journal, December 2000

  • Henkelman, Graeme; Jónsson, Hannes
  • The Journal of Chemical Physics, Vol. 113, Issue 22
  • DOI: 10.1063/1.1323224

Stress-induced hydrogen self-trapping in tungsten
journal, October 2018


The influence of the annealing temperature on deuterium retention in self-damaged tungsten
journal, January 2016


Plasma-material interactions in current tokamaks and their implications for next step fusion reactors
journal, December 2001