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Title: Thermal desorption spectroscopy of high fluence irradiated ultrafine and nanocrystalline tungsten: helium trapping and desorption correlated with morphology

Journal Article · · Nuclear Fusion

Here, microstructural changes due to displacement damage and helium desorption are two phenomena that occur in tungsten plasma facing materials in fusion reactors. Nanocrystalline metals are being investigated as radiation tolerant materials that can mitigate these microstructural changes and better trap helium along their grain boundaries. Here, we investigate the performance of three tungsten grades (nanocrystalline, ultrafine and ITER grade tungsten), exposed to a high fluence of 4 keV helium at both RT and 773 K, during a thermal desorption spectroscopy (TDS) experiment. An investigation of the microstructure in pre-and post-TDS sample sets was performed. The amount of desorbed helium was shown to be highest in the ITER grade tungsten and lowest in the nanocrystalline tungsten. Correlating the desorption spectra and the microstructure (grain boundaries decorated with nanopores and crack formation) and comparing with previous literature on coarse grained tungsten samples at similar irradiation and TDS conditions, revealed the importance of grain boundaries in trapping helium and limiting helium desorption up to a high temperature of 1350 K in agreement with transmission electron microscopy studies on helium irradiated tungsten which showed preferential and large facetted bubble formation along the grain boundaries in the nanocrystalline tungsten grade.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1419755
Report Number(s):
LA-UR-17-24924; TRN: US1801388
Journal Information:
Nuclear Fusion, Vol. 58, Issue 1; ISSN 0029-5515
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 23 works
Citation information provided by
Web of Science

References (63)

Plasma–surface interaction, scrape-off layer and divertor physics: implications for ITER journal August 2007
Tungsten: an option for divertor and main chamber plasma facing components in future fusion devices journal March 2005
Formation mechanism of bubbles and holes on tungsten surface with low-energy and high-flux helium plasma irradiation in NAGDIS-II journal August 2004
Suppression of blister formation and deuterium retention on tungsten surface due to mechanical polishing and helium pre-exposure journal June 2005
Helium and deuterium implantation in tungsten at elevated temperatures journal December 2005
Surface damage in ultrafine and multimodal grained tungsten materials induced by low energy helium irradiation journal March 2013
Formation of helium induced nanostructure ‘fuzz’ on various tungsten grades journal September 2010
Materials challenges in nuclear energy journal February 2013
Structural materials for fission & fusion energy journal November 2009
Effect of Alloy Composition & Helium ion-irradiation on the Mechanical Properties of Tungsten, Tungsten-Tantalum & Tungsten-Rhenium for Fusion Power Applications journal January 2013
Structural materials for Gen-IV nuclear reactors: Challenges and opportunities journal December 2008
An equilibrium model for tungsten fuzz in an eroding plasma environment journal March 2011
Helium retention of plasma facing materials journal March 1999
The influence of high grain boundary density on helium retention in tungsten journal February 2015
In-situ TEM observation of the response of ultrafine- and nanocrystalline-grained tungsten to extreme irradiation environments journal May 2014
In-situ TEM/heavy ion irradiation on ultrafine-and nanocrystalline-grained tungsten: Effect of 3 MeV Si, Cu and W ions journal January 2015
Defect-interface interactions journal October 2015
Effect of grain boundary character on sink efficiency journal October 2012
Observations of suppressed retention and blistering for tungsten exposed to deuterium–helium mixture plasmas journal May 2009
Calculated grain size-dependent vacancy supersaturation and its effect on void formation journal April 1974
Nucleation of helium bubbles on dislocations, dislocation networks and dislocations in grain boundaries during 600 MeV proton irradiation of aluminium journal August 1984
Interface Structure and Radiation Damage Resistance in Cu-Nb Multilayer Nanocomposites journal April 2008
Radiation damage near grain boundaries journal October 2003
Efficient Annealing of Radiation Damage Near Grain Boundaries via Interstitial Emission journal March 2010
Ultrafine tungsten as a plasma-facing component in fusion devices: effect of high flux, high fluence low energy helium irradiation journal June 2014
Helium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions journal March 2015
Influence of grain boundaries on the radiation-induced defects and hydrogen in nanostructured and coarse-grained tungsten journal January 2017
Microstructure and mechanical properties of super-strong nanocrystalline tungsten processed by high-pressure torsion journal September 2006
Microstructure refinement of tungsten by surface deformation for irradiation damage resistance journal January 2014
Material ejection and surface morphology changes during transient heat loading of tungsten as plasma-facing component in fusion devices journal February 2015
Thermal desorption and surface modification of He+ implanted into tungsten journal August 2004
Flux dependence of deuterium retention in single crystal tungsten journal December 2002
ScientiFig: a tool to build publication-ready scientific figures journal October 2013
Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples journal November 2014
High Resolution Focused Ion Beams: FIB and its Applications: The Physics of Liquid Metal Ion Sources and Ion Optics and Their Application to Focused Ion Beam Technology book January 2003
Effects of Low Energy and High Flux Helium/Hydrogen Plasma Irradiation on Tungsten as Plasma Facing Material journal June 2005
SRIM – The stopping and range of ions in matter (2010)
  • Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
  • Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12 https://doi.org/10.1016/j.nimb.2010.02.091
journal June 2010
Long-Range Migration of Self-Interstitial Atoms in Tungsten journal December 1975
Vacancy defect mobilities and binding energies obtained from annealing studies journal February 1978
First temperature stage evolution of irradiation-induced defects in tungsten studied by positron annihilation spectroscopy journal May 2008
Range Profiles of 300- and 475-eV He + 4 Ions and the Diffusivity of He 4 in Tungsten journal February 1979
Helium diffusion in tungsten: A molecular dynamics study journal May 2013
The behavior of small helium clusters near free surfaces in tungsten journal November 2014
Microstructure evolution in tungsten during low-energy helium ion irradiation journal December 2000
Assessment of tungsten for use in the ITER plasma facing components journal October 1998
Recrystallization, grain growth and the ductile-brittle transition in tungsten sheet journal August 1967
Thermal desorption of helium from polycrystalline Ni irradiated to fluences ranging from to journal December 1987
TEM observation of the growth process of helium nanobubbles on tungsten: Nanostructure formation mechanism journal November 2011
Dynamic fuel retention in tokamak wall materials: An in situ laboratory study of deuterium release from polycrystalline tungsten at room temperature journal December 2015
The response of polycrystalline tungsten to 30keV helium ion implantation at normal incidence and high temperatures journal June 2012
A description of stress driven bubble growth of helium implanted tungsten journal May 2009
A description of bubble growth and gas release of helium implanted tungsten journal April 2009
Helium bubble nucleation in bcc iron studied by kinetic Monte Carlo simulations journal April 2007
Retention and thermal desorption of helium in pure tungsten journal November 2016
Grain size threshold for enhanced irradiation resistance in nanocrystalline and ultrafine tungsten journal February 2017
Reduction of helium ash by selective helium pumping journal September 1994
Poloidal divertor configuration with ripple limiters for a fusion experimental reactor journal July 1995
Effect of He on D retention in W exposed to low-energy, high-fluence (D, He, Ar) mixture plasmas journal August 2011
Helium irradiation effects on tritium retention and long-term tritium release properties in polycrystalline tungsten journal August 2015
Early stage damage of ultrafine-grained tungsten materials exposed to low energy helium ion irradiation journal April 2015
Ion channeling effects on the focused ion beam milling of Cu
  • Kempshall, B. W.; Schwarz, S. M.; Prenitzer, B. I.
  • Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, Vol. 19, Issue 3 https://doi.org/10.1116/1.1368670
journal January 2001
Motion of swift charged particles, as influenced by strings of atoms in crystals journal September 1964
THE INFLUENCE OF CHANNELING ON Cu SINGLE‐CRYSTAL SPUTTERING journal April 1966

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