Helium retention behavior in simultaneously He+-H2+ irradiated tungsten

Zhou, Qilai; Azuma, Keisuke; Togari, Akihiro; Yajima, Miyuki; Tokitani, M.; Masuzaki, S.; Yoshida, N.; Hara, Masanori; Hatano, Yuji; Oya, Yasuhisa

doi:10.1016/j.jnucmat.2018.02.035

Cited by 17 publications

(6 citation statements)

References 25 publications

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“…Hydrogen isotopes will be trapped by helium-vacancy clusters and their retention in tungsten will increase. The interaction between helium and hydrogen isotopes will accelerate an obvious degradation in irradiation performance [26][27][28], which was investigated under the sequence-ion (H/He or He/H) irradiation [29,30]. The corresponding research results show that the different orders of hydrogen and helium irradiation obviously affects the irradiation results such as the evolution, size, density and distribution characteristics of loops and bubbles.…”

Section: Introductionmentioning

confidence: 99%

In-situ transmission electron microscopy observation of the evolution of dislocation loops and gas bubbles in tungsten during H2+ and He+ dual-beam irradiation

Ding

Liu

et al. 2021

Tungsten

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Dislocation loop and gas bubble evolution in tungsten were in-situ investigated under 30 keV H 2 + and He + dual-beam irradiation at 973 K and 1173 K. The average size and number density of dislocation loops and gas bubbles were obtained as a function of irradiation dose. The quantitative calculation and analysis of the migration distance of 1/2 ⟨111⟩ loops at low irradiation dose indicated that the main mechanism of the formation of ⟨100⟩ loops should be attributed to the high-density helium cluster inducement mechanism, instead of the 1/2 ⟨111⟩ loop reaction mechanism. H 2 + and He + dual-beam irradiation induced the formation of ⟨100⟩ loops and 1/2 ⟨111⟩ loops, while increasing the irradiation temperature would increase ⟨100⟩ loop percentage. The percentage of ⟨100⟩ loops was approximately 18.6% at 973 K and increased to 22.9% at 1173 K. The loop reaction between two 1/2 ⟨111⟩ loops to form a large-sized 1/2 ⟨111⟩ loop was in-situ observed, which induced not only the decrease of the number of 1/2 ⟨111⟩ loops but also the significant increase of their sizes. The ⟨100⟩ loops impeded the movement of dislocation line and tended to escape from it instead of being absorbed. With the increase of irradiation dose, the yield strength increment ( Δ loop ) caused by the change of loop size and density increased first and then decreased slightly, while the yield strength increment ( Δ bubble ) caused by the change of bubble size and density always increased. Meanwhile, within the current irradiation dose range, Δ loop was much larger than Δ bubble .

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Section: Introductionmentioning

confidence: 99%

In-situ transmission electron microscopy observation of the evolution of dislocation loops and gas bubbles in tungsten during H2+ and He+ dual-beam irradiation

Ding

Liu

et al. 2021

Tungsten

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“…Some other general materials test facilities are available in NIFS. In particular, FETEM-EDS (Field Emission Transmission Electron Microscope-Energy Dispersive X-ray Spectrometer), FIB 10 (Focused Ion Beam), GD-OES (Glow Discharge Optical Emission Spectrometer), Imaging Plate system, and TDS (Thermal Desorption Spectrometer) 34 have been installed in the radiationcontrolled area of LHD site, allowing characterization of the specimens exposed to D-D plasma of LHD. This activity is promoted mostly by the Large Helical Device Project in NIFS.…”

Section: Ii-b Major Fusion Engineering Facilities In Nifs and Their C...mentioning

confidence: 99%

“…Tritium system for LHD 10 Thermal Desorption Spectroscopy 34 Application of proton conductors 85 Water detritiation 86,87 Non-destructive retention measurements 88 41 Table 2. Examples of infrastructure in Universities used for fusion engineering research.…”

Section: Research Subjects Major Emphases Key Facilities In Nifs Exam...mentioning

confidence: 99%

Overview of Fusion Engineering Research in Japan Focusing on Activities in NIFS and Universities

Muroga

Fukada

Hayashi

2019

Fusion Science and Technology

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This paper provides an overview of Japanese fusion engineering research activities focusing on those being carried out by NIFS and Japanese universities (Universities). NIFS is promoting the Fusion Engineering Research Project as one of the three research projects. The majority of the activity in the project is being carried out by collaboration with Universities. Utilizing core facilities installed in NIFS and the unique infrastructures of Universities, collaboration between NIFS and Universities is performed in superconducting magnet, liquid breeder blanket, advanced materials, high heat flux components, and tritium safety. NIFS also carries out international collaboration programs, such as Japan-China, Japan-USA, and IEA-based collaborations, promoting participation of University researchers. Responsibility division with QST, and contributions to ITER-BA and "Action Plan toward DEMO Development" are also reported.

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“…H isotope retention should be minimized to prevent interference with fuel reactions and to reduce tritium (T) inventory. Recent research has established that H and He not only cause damage to W separately but also exhibit synergistic effects that further increase H isotope retention in W, thereby impairing material structure and performance [17,18]. Experiments using mixed ion beam and plasma accelerators have demonstrated that under mixed H and He exposures, the interaction between H isotopes and He significantly enhances H retention [19,20].…”

Section: Introductionmentioning

confidence: 99%

Temperature-dependent bubble growth under synergistic interactions of hydrogen and helium in tungsten

Niu,

Qin,

Suman

et al. 2024

Nucl. Fusion

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A novel theoretical model based on modified diffusion rate equations is proposed to simulate the retention of hydrogen isotopes and the dynamics of bubble growth in tungsten (W) when exposed to simultaneous hydrogen (H) and helium (He) plasma irradiations. Simulation is conducted to assess the influence of temperature as well as simultaneous H and He irradiation at an increasing fluence. Not only to develop a holistic understanding but also to substantiate simulation findings about synergy between H and He plasma irradiation, a W sample is exposed sequentially to H and He plasma at 873 K using the large-power material irradiation experimental system (LP-MIES). The topographical changes in the W sample are investigated using atomic force microscopy (AFM) after each plasma irradiation exposure sequence. Simulation results reveal that the ability of a bubble containing both H and He to trap adjacent H/He atoms is primarily governed by their individual partial pressure within the bubble. Furthermore, at elevated temperatures, the synergy between H and He significantly enhances the retention of H isotopes in W. AFM micrographs of the W sample exposed to both H and He plasma irradiation show a severely damaged and locally delaminated layer, absent in the sample exposed only to either H or He, conclusively establishing evidence of synergy between H and He irradiation effects. The average bubble radius computed using the model aligns excellently with experimentally determined values obtained through SEM/AFM analysis. The robustness of the proposed model is also assessed by comparing bubble radius and H isotopes retention at various temperatures with experimental data reported in the literature.

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Helium retention behavior in simultaneously He+-H2+ irradiated tungsten

Cited by 17 publications

References 25 publications

In-situ transmission electron microscopy observation of the evolution of dislocation loops and gas bubbles in tungsten during H2+ and He+ dual-beam irradiation

In-situ transmission electron microscopy observation of the evolution of dislocation loops and gas bubbles in tungsten during H2+ and He+ dual-beam irradiation

Overview of Fusion Engineering Research in Japan Focusing on Activities in NIFS and Universities

Temperature-dependent bubble growth under synergistic interactions of hydrogen and helium in tungsten

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