Quantum Beam Science

9 pages, 2568 KiB

Open AccessArticle

Effect of Irradiation on Corrosion Behavior of 316L Steel in Lead-Bismuth Eutectic with Different Oxygen Concentrations

by Nariaki Okubo, Yuki Fujimura and Masakatsu Tomobe

Quantum Beam Sci. 2021, 5(3), 27; https://doi.org/10.3390/qubs5030027 - 31 Aug 2021

Cited by 7 | Viewed by 3655

In an accelerator-driven system (ADS), the beam window material of the spallation neutron target is heavily irradiated under severe conditions, in which the radiation damage and corrosion co-occur because of high-energy neutron and/or proton irradiation in the lead–bismuth flow. The materials used in [...] Read more.

In an accelerator-driven system (ADS), the beam window material of the spallation neutron target is heavily irradiated under severe conditions, in which the radiation damage and corrosion co-occur because of high-energy neutron and/or proton irradiation in the lead–bismuth flow. The materials used in ADSs must be compatible with the liquid metal (lead–bismuth eutectic (LBE)) to prevent issues such as liquid metal embrittlement (LME) and liquid metal corrosion (LMC). This study considers the LMC behavior after ion irradiation of 316L austenitic steel for self-ion irradiations followed by the corrosion tests in LBE with critical oxygen concentration. The 316L samples were irradiated by 10.5 MeV-Fe³⁺ ions at a temperature of 450 °C, up to 50 displacements per atom (dpa). After the corrosion test performed at 450 °C in LBE with low oxygen concentration, a surface of the nonirradiated area was not oxidized but appeared with locally corrosive morphology, Ni depletion, whereas an iron/chromium oxide layer fully covered the irradiated area. In the case of the corrosion surface with high oxygen concentration in LBE, the surface of the nonirradiated area was covered by an iron oxide layer only, whereas the irradiated area was covered by the duplex layers comprising iron and iron/chromium oxides. It is suggested that irradiation can enhance the oxide layer formation because of the enhancement of Fe and/or oxygen diffusion induced by the radiation defects in 316L steel. Full article

(This article belongs to the Special Issue The Modifications of Metallic and Inorganic Materials by Using Energetic Ion/Electron Beams)

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11 pages, 4624 KiB

Open AccessArticle

Correlation between Microstructural Change and Irradiation Hardening Behavior of He-Irradiated V–Cr–Ti Alloys with Low Ti Addition

by Ken-ichi Fukumoto, Shuichiro Miura, Yoshiki Kitamura, Ryoya Ishigami and Takuya Nagasaka

Quantum Beam Sci. 2021, 5(3), 26; https://doi.org/10.3390/qubs5030026 - 31 Aug 2021

Cited by 9 | Viewed by 2684

Abstract

V–4Cr–xTi (x = 0 to 4) alloys were used to investigate the additional effect of Cr, Ti and interstitial impurities on the microstructural evolution in He-irradiated V–Cr–Ti alloys to minimize radioactivity after fusion neutron irradiation. Transmission electron microscopy and atom probe tomography were [...] Read more.

V–4Cr–xTi (x = 0 to 4) alloys were used to investigate the additional effect of Cr, Ti and interstitial impurities on the microstructural evolution in He-irradiated V–Cr–Ti alloys to minimize radioactivity after fusion neutron irradiation. Transmission electron microscopy and atom probe tomography were carried out to the He-irradiated specimens at 500 °C with 0.5 dpa at peak damage. A flash electro-polishing method for the FIB-extracted specimen was established for the ion-irradiated vanadium alloys. The microstructural evolution of the irradiation-induced titanium-oxycarbonitride, Ti(CON) precipitates was observed and was influenced by the effect of Ti addition on the Ti(CON) precipitation. Apparent Ti(CON) precipitates formed in V-4Cr-xTi with 2% addition of Ti. In the V-4Cr-1Ti alloy, a high density Ti enriched cluster was formed. The origin of the irradiation hardening increase resulted from the size distribution of Ti(CON) precipitation from the dispersed barrier-hardening theory. Full article

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7 pages, 1372 KiB

Open AccessFeature PaperArticle

Proton-Cluster-Beam Lethality and Mutagenicity in Bacillus subtilis Spores

by Yoshihiro Hase, Katsuya Satoh, Atsuya Chiba, Yoshimi Hirano, Kengo Moribayashi and Kazumasa Narumi

Quantum Beam Sci. 2021, 5(3), 25; https://doi.org/10.3390/qubs5030025 - 28 Aug 2021

Cited by 4 | Viewed by 3867

Abstract

The unique energy transfer characteristics of swift cluster ions have attracted the attention of many researchers working on the analysis or processing of material surfaces, but the effects on living organisms remain unclear. We irradiated B. subtilis spores with monomer and cluster proton [...] Read more.

The unique energy transfer characteristics of swift cluster ions have attracted the attention of many researchers working on the analysis or processing of material surfaces, but the effects on living organisms remain unclear. We irradiated B. subtilis spores with monomer and cluster proton beams and examined their lethality; the 2 MeV H₂⁺ shows a clearly lower lethality than 340 keV H⁺, even though both have a comparable linear energy transfer. The 2 MeV H₂⁺ dissociates into a pair of 1 MeV H⁺ by losing the bonding electrons at the target surface. The estimated internuclear distance and the radial dose distribution suggest that the spread of deposited total energy over two areas separated by just several nanometers greatly diminishes beam lethality and that the energy density in the very center of the trajectory, possibly within a 1 nm radius, has a great impact on lethality. We also performed a whole genome resequencing of the surviving colonies to compare the molecular nature of mutations but failed to find a clear difference in overall characteristics. Our results suggest that cluster beams may be a useful tool for understanding biological effects of high linear energy transfer radiation. Full article

(This article belongs to the Special Issue Swift Cluster Ion Beams: Basic Processes and Applications)

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4 pages, 206 KiB

Open AccessErratum

Erratum: Cureton et al. Review of Swift Heavy Ion Irradiation Effects in CeO₂. Quantum Beam Sci. 2021, 5, 19

by William F. Cureton, Cameron L. Tracy and Maik Lang

Quantum Beam Sci. 2021, 5(3), 24; https://doi.org/10.3390/qubs5030024 - 6 Aug 2021

Cited by 1 | Viewed by 2412

Abstract

During the final production steps after the proofreading of this paper [...] Full article

20 pages, 18557 KiB

Open AccessReview

Control and Modification of Nanostructured Materials by Electron Beam Irradiation

by Shun-Ichiro Tanaka

Quantum Beam Sci. 2021, 5(3), 23; https://doi.org/10.3390/qubs5030023 - 21 Jul 2021

Cited by 4 | Viewed by 4393

Abstract

I have proposed a bottom-up technology utilising irradiation with active beams, such as electrons and ions, to achieve nanostructures with a size of 3–40 nm. This can be used as a nanotechnology that provides the desired structures, materials, and phases at desired positions. [...] Read more.

I have proposed a bottom-up technology utilising irradiation with active beams, such as electrons and ions, to achieve nanostructures with a size of 3–40 nm. This can be used as a nanotechnology that provides the desired structures, materials, and phases at desired positions. Electron beam irradiation of metastable θ-Al₂O₃, more than 10¹⁹ e/cm²s in a transmission electron microscope (TEM), enables the production of oxide-free Al nanoparticles, which can be manipulated to undergo migration, bonding, rotation, revolution, and embedding. The manipulations are facilitated by momentum transfer from electrons to nanoparticles, which takes advantage of the spiral trajectory of the electron beam in the magnetic field of the TEM pole piece. Furthermore, onion-like fullerenes and intercalated structures on amorphous carbon films are induced through catalytic reactions. δ-, θ-Al₂O₃ ball/wire hybrid nanostructures were obtained in a short time using an electron irradiation flashing mode that switches between 10¹⁹ and 10²² e/cm²s. Various α-Al₂O₃ nanostructures, such as encapsulated nanoballs or nanorods, are also produced. In addition, the preparation or control of Pt, W, and Cu nanoparticles can be achieved by electron beam irradiation with a higher intensity. Full article

(This article belongs to the Special Issue The Modifications of Metallic and Inorganic Materials by Using Energetic Ion/Electron Beams)

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10 pages, 3473 KiB

Open AccessFeature PaperArticle

Validation of a Sapphire Gas-Pressure Cell for Real-Time In Situ Neutron Diffraction Studies of Hydrogenation Reactions

by Raphael Finger, Thomas C. Hansen and Holger Kohlmann

Quantum Beam Sci. 2021, 5(3), 22; https://doi.org/10.3390/qubs5030022 - 15 Jul 2021

Cited by 4 | Viewed by 2983

Abstract

A gas-pressure cell, based on a leuco-sapphire single-crystal, serving as a pressure vessel and sample holder, is presented for real time in situ studies of solid-gas hydrogenation reactions. A stainless steel corpus, coated with neutron absorbing varnish, allows alignment for the single-crystal sample [...] Read more.

A gas-pressure cell, based on a leuco-sapphire single-crystal, serving as a pressure vessel and sample holder, is presented for real time in situ studies of solid-gas hydrogenation reactions. A stainless steel corpus, coated with neutron absorbing varnish, allows alignment for the single-crystal sample holder for minimizing contributions to the diffraction pattern. Openings in the corpus enable neutron scattering as well as contactless temperature surveillance and laser heating. The gas-pressure cell is validated via the deuteration of palladium powder, giving reliable neutron diffraction data at the high-intensity diffractometer D20 at the Institut Laue-Langevin (ILL), Grenoble, France. It was tested up to 15.0 MPa of hydrogen pressure at room temperature, 718 K at ambient pressure and 584 K at 9.5 MPa of hydrogen pressure. Full article

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12 pages, 6297 KiB

Open AccessFeature PaperArticle

Fabrication of Size- and Shape-Controlled Platinum Cones by Ion-Track Etching and Electrodeposition Techniques for Electrocatalytic Applications

by Yuma Sato, Hiroshi Koshikawa, Shunya Yamamoto, Masaki Sugimoto, Shin-ichi Sawada and Tetsuya Yamaki

Quantum Beam Sci. 2021, 5(3), 21; https://doi.org/10.3390/qubs5030021 - 1 Jul 2021

Cited by 3 | Viewed by 3382

Abstract

The micro/nanocone structures of noble metals play a critical role as heterogeneous electrocatalysts that provide excellent activity. We successfully fabricated platinum cones by electrodeposition using non-penetrated porous membranes as templates. This method involved the preparation of template membranes by the swift-heavy-ion irradiation of [...] Read more.

The micro/nanocone structures of noble metals play a critical role as heterogeneous electrocatalysts that provide excellent activity. We successfully fabricated platinum cones by electrodeposition using non-penetrated porous membranes as templates. This method involved the preparation of template membranes by the swift-heavy-ion irradiation of commercially available polycarbonate films and subsequent chemical etching in an aqueous NaOH solution. The surface diameter, depth, aspect ratio and cone angle of the resulting conical pores were controlled in the ranges of approximately 70–1500 nm, 0.7–11 μm, 4–12 and 5–13°, respectively, by varying the etching conditions, which finally produced size- and shape-controlled platinum cones with nanotips. In order to demonstrate the electrocatalytic activity, electrochemical measurements were performed for the ethanol oxidation reaction. The oxidation activity was found to be up to 3.2 times higher for the platinum cone arrays than for the platinum plate. Ion-track etching combined with electrodeposition has the potential to be an effective method for the fabrication of micro/nanocones with high electrocatalytic performance. Full article

(This article belongs to the Special Issue The Modifications of Metallic and Inorganic Materials by Using Energetic Ion/Electron Beams)

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9 pages, 2223 KiB

Open AccessArticle

Phase Transformation by 100 keV Electron Irradiation in Partially Stabilized Zirconia

by Yasuki Okuno and Nariaki Okubo

Quantum Beam Sci. 2021, 5(3), 20; https://doi.org/10.3390/qubs5030020 - 25 Jun 2021

Cited by 4 | Viewed by 3016

Abstract

Partially stabilized zirconia (PSZ) is considered for use as an oxygen-sensor material in liquid lead-bismuth eutectic (LBE) alloys in the radiation environment of an acceleration-driven system (ADS). To predict its lifetime for operating in an ADS, the effects of radiation on the PSZ [...] Read more.

Partially stabilized zirconia (PSZ) is considered for use as an oxygen-sensor material in liquid lead-bismuth eutectic (LBE) alloys in the radiation environment of an acceleration-driven system (ADS). To predict its lifetime for operating in an ADS, the effects of radiation on the PSZ were clarified in this study. A tetragonal PSZ was irradiated with 100 keV electrons and analyzed by X-ray diffraction (XRD). The results indicate that the phase transition in the PSZ, from the tetragonal to the monoclinic phase, was caused after the irradiation. The deposition energy of the lattice and the deposition energy for the displacement damage of a 100 keV electron in the PSZ are estimated using the particle and heavy ion transport code system and the non-ionizing energy loss, respectively. The results suggest that conventional radiation effects, such as stopping power, are not the main mechanism behind the phase transition. The phase transition is known to be caused by the low-temperature degradation of the PSZ and is attributed to the shift of oxygen ions to oxygen sites. When the electron beam is incident to the material, the kinetic energy deposition and excitation-related processes are caused, and it is suggested to be a factor of the phase transition. Full article

(This article belongs to the Special Issue The Modifications of Metallic and Inorganic Materials by Using Energetic Ion/Electron Beams)

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Quantum Beam Sci., Volume 5, Issue 3 (September 2021) – 8 articles

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