Low-energy helium plasma effects on textured micro-porous tungsten

Gao, Edward; Doerner, R.; Williams, Benjamin S.; Ghoniem, Nasr M.

doi:10.1016/j.jnucmat.2019.01.047

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…Moreover, nanoporosity from magnetron deposited films can be responsible for higher densities of bubble nucleation sites but this porosity can reduce with irradiation [29] due to adatom accumulation occurring before reaching a stable bubble size. Nanoporous materials were shown to enhance irradiation tolerance in different materials [30][31][32]. Nanoporosity and possible impurities can also limit the mean free path of defect mobility and thus explain the high density of He bubbles in the NCW.…”

Section: He Bubble Evolution As a Function Of He + Fluencementioning

confidence: 99%

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

et al. 2020

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The use of ultrafine and nanocrystalline materials is a proposed pathway to mitigate irradiation damage in nuclear fusion components. Here, we examine the radiation tolerance of helium bubble formation in 85 nm (average grain size) nanocrystalline-equiaxed-grained tungsten and an ultrafine tungsten-TiC alloy under extreme low energy helium implantation at 1223 K via in-situ transmission electron microscope (TEM). Helium bubble damage evolution in terms of number density, size, and total volume contribution to grain matrices has been determined as a function of He + implantation fluence. The outputs were compared to previously published results on severe plastically deformed (SPD) tungsten implanted under the same conditions. Large helium bubbles were formed on the grain boundaries and helium bubble damage evolution profiles are shown to differ among the different materials with less overall damage in the nanocrystalline tungsten. Compared to previous works, the results in this work indicate that the nanocrystalline tungsten should possess a fuzz formation threshold more than one order of magnitude higher than coarse-grained tungsten.

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Section: He Bubble Evolution As a Function Of He + Fluencementioning

confidence: 99%

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

et al. 2020

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“…Surface microstructures have also been studied under MCF conditions and, although in this case there exist more irradiation facilities, the high fluxes of low-energy ions complicate the development of a solid material able to withstand the irradiation conditions. Nonetheless, recent works report on significant improvements for micro-modified surfaces [35,36]. Further size reduction from the micrometre to the nanometre level has been explored, and nanostructured materials are regarded as a viable alternative to prevent He accumulation and the associated bubble growth [37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

Highly porous tungsten for plasma-facing applications in nuclear fusion power plants: a computational analysis of hollow nanoparticles

et al. 2020

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Plasma-facing materials (PFMs) for nuclear fusion, either in inertial confinement fusion (ICF) or in magnetic confinement fusion (MCF) approaches, must withstand extremely hostile irradiation conditions. Mitigation strategies are plausible in some cases, but usually the best, or even the only, solution for feasible plant designs is to rely on PFMs able to tolerate these irradiation conditions. Unfortunately, many studies report a lack of appropriate materials that have a good thermomechanical response and are not prone to deterioration by means of irradiation damage. The most deleterious effects are vacancy clustering and the retention of light species, as is the case for tungsten. In an attempt to find new radiation-resistant materials, we studied tungsten hollow nanoparticles under different irradiation scenarios that mimic ICF and MCF conditions. By means of classical molecular dynamics, we determined that these particles can resist astonishingly high temperatures (up to ∼3000 K) and huge internal pressures (>5 GPa at 3000 K) before rupture. In addition, in the case of gentle pressure increase (ICF scenarios), a self-healing mechanism leads to the formation of an opening through which gas atoms are able to escape. The opening disappears as the pressure drops, restoring the original particle. Regarding radiation damage, object kinetic Monte Carlo simulations show an additional self-healing mechanism. At the temperatures of interest, defects (including clusters) easily reach the nanoparticle surface and disappear, which makes the hollow nanoparticles promising for ICF designs. The situation is less promising for MCF because the huge ion densities expected at the surface of PFMs lead to inevitable particle rupture.

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Mechanical properties and deformation mechanism of tungsten/titanium hybrid foam

Zhang

Wei

et al. 2023

International Journal of Refractory Metals and Hard Materials

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Low-energy helium plasma effects on textured micro-porous tungsten

Cited by 6 publications

References 29 publications

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

Highly porous tungsten for plasma-facing applications in nuclear fusion power plants: a computational analysis of hollow nanoparticles

Mechanical properties and deformation mechanism of tungsten/titanium hybrid foam

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