Article
Chemistry, Physical
W. W. Zhang, P. H. Shi, B. D. Yao, L. Wu, X. Y. Wu, L. Q. Shi, Y. X. Wang
Summary: The research utilized molecular dynamics simulations to study the evolution of tungsten surface morphology under helium irradiation, revealing that the generation and bursting of helium bubbles lead to surface protrusions, ultimately forming a fiber-like structure. The diffusion, aggregation, and bursting of helium bubbles are crucial processes driving the changes in surface morphology.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Dong-Dong Jiang, Jian-Li Shao, An-Min He, Pei Wang
Summary: This study investigates the individual and combined effects of He bubbles and grain boundaries on the spallation of aluminum at different strain rates. The results show that both He bubbles and grain boundaries decrease the spall strength, with the presence of a grain boundary reducing the effect of He bubbles by about 50%. Additionally, it is found that He bubbles inhibit void nucleation and growth, while grain boundaries determine the location and mechanism of void or He bubble nucleation and growth, resulting in a more rapid reduction in spall strength in polycrystals compared to single crystals as the strain rate decreases. Furthermore, a linear relationship is observed between the spall strength of polycrystalline Al and the fraction of He atoms when the He concentration is below 0.4 at.%.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Mechanical
Wei-Dong Wu, Jian-Li Shao
Summary: The coalescence mechanism of helium bubbles in aluminum under shock compression is revealed using atomistic simulations and theoretical analysis. Two coalescence modes driven by ligament failure and interface deformation are discovered. The time required for coalescence is predicted using the Frenkel-like model based on the balance of surface tension and viscous forces. The findings provide insights into the mechanical properties of irradiated metals.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Qi Zhu, Jian-Li Shao, Pei Wang
Summary: This study investigates the dynamic response of He bubbles in bicrystal Cu under uniaxial compression and tension using molecular dynamics simulations. It reveals that the different positions of He bubbles in grain interiors and grain boundaries result in different behaviors, particularly affecting the yielding behaviors of the material.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Nuclear Science & Technology
Jiechao Cui, Qing Hou, Min Li, Mingjie Qiu
Summary: This study investigates the radiation damage in tungsten used as a plasma-facing material in fusion reactors. It finds that the least defects are produced when cascades overlap with bubbles with specific helium-to-vacancy ratios, while other bubbles may facilitate defect formation. The study identifies two mechanisms for generating dislocation loops and advances our understanding of radiation damage in complex environments.
NUCLEAR MATERIALS AND ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Qi Zhu, Jianli Shao, Pei Wang
Summary: This work uses molecular dynamics simulations to reveal the interaction mechanism between helium bubbles and grain boundaries in bicrystal copper under shear loading. The influences of helium/vacancy ratio, temperature, and bubble diameter on the interaction mechanism are clarified.
Article
Materials Science, Multidisciplinary
Meng Huang, Jianyu Zhu, Jun Wu
Summary: This paper studies the collision cascades of NaI crystals by means of molecular dynamics simulation, providing a theoretical basis for the research of radiation damage of NaI crystals. The calculated threshold displacement energies of NaI crystals show that the maximum values for recoiled Na and I atoms are 49.5 eV and 80.6 eV respectively at a material temperature of 300 K. The simulation and analysis of collision cascade processes reveal the variation laws between the number of displaced atoms, atom spatial distribution in the NaI crystal, and time.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Ke Xu, Shuo Jin, Yu-Hao Li, Hong-Bo Zhou, Hongxian Xie, Ning Gao, Fei Gao, Guang-Hong Lu
Summary: This study reveals the crucial process of loop-punching during the growth of helium bubbles in metals through molecular dynamics simulations. The observation of two plastic deformation modes, tangential PD and normal PD, provides an explanation for the two-stage loop-punching.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Physics, Applied
Pandong Lin, Junfeng Nie, Meidan Liu
Summary: The molecular dynamics method is used to study irradiation-induced damage, showing that an increase in PKA energy, vacancy concentration, and tensile pre-strain leads to more defects, while an increase in temperature reduces defect numbers. Tensile tests indicate that the mechanical properties of irradiated Fe decrease with an increase in Frenkel pairs.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2021)
Article
Crystallography
Hai Huang, Xiaoting Yuan, Xiaoxin Ge, Qing Peng
Summary: This study investigates the effects of intrinsic and irradiation-induced defects in graphene on the displacement damage and He diffusion in Ni-graphene nanocomposites. The results show that the presence of intrinsic defects significantly affects the Ni lattice structure near the Ni-graphene interface. The irradiation-induced defects, on the other hand, do not decrease the ability of the interface to trap He atoms/clusters and may even improve it.
Article
Chemistry, Physical
Yuan Xiang, Bin Zhang, Liqun Shi
Summary: Using molecular dynamics simulations, this study investigates the evolution of deuterium bubbles in tungsten, including the formation, growth, and burst. The effects of flux, temperature, and incident energy of deuterium on the evolution and position of the bubbles are discussed. It is found that the evolution of bubbles is more difficult on surfaces with higher crystal face density.
APPLIED SURFACE SCIENCE
(2022)
Article
Thermodynamics
Patrick Sullivan, Duncan Dockar, Ryan Enright, Matthew K. Borg, Rohit Pillai
Summary: This study investigates the growth process of heterogeneous vapor bubbles under different surface conditions and finds that surface wettability plays an important role in the shape and dynamics of the bubbles. These findings have the potential to improve the performance of systems involving phase change from liquid to vapor.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Review
Chemistry, Physical
Yu-Jie Chen, Wei Lu, Bo Yu, Wen-Quan Tao, Wenjing Zhou, Qun Cao
Summary: Bubble nucleation in boiling heat transfer is a microscale phenomenon. The commonly used molecular dynamics simulation method often requires an unreasonable heating temperature to achieve bubble nucleation in liquid argon. This study proposes a revised potential model for bubble nucleation study of argon, which can lower the onset nucleation temperature and avoid the unreasonable change of liquid argon properties.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Materials Science, Multidisciplinary
Shang Tian, Chaohui He, Huan He, Wenlong Liao, Yurong Bai, Yonghong Li
Summary: The study investigates displacement cascades evolution in GaAs using molecular dynamics simulations, revealing that higher PKA energy leads to a slight delay in the onset of heat spike phase. The non-linear increase in surviving defect count with PKA energy rise is attributed to directly amorphous pockets, and medium and large vacancy clusters only emerge in the middle of cascades.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Jianqi Xi, Yeqi Shi, Vitaly Pronskikh, Frederique Pellemoine, Dane Morgan, Izabela Szlufarska
Summary: Using atomistic simulations, we investigated the behavior of helium bubbles in beryllium, focusing on their shape, stability, and diffusivity. We found that helium bubbles become unstable and change shape through plastic deformation when the helium-vacancy ratio exceeds 1.25. The dominant diffusion mechanism of helium bubbles changes from surface diffusion to volume diffusion at around 900 K. The results provide valuable insights into the microstructural evolution and properties of irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Instruments & Instrumentation
Taisei Hayashi, Kensei Ichiba, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida
Summary: In this study, Cr-doped Mg4Ta2O9 single crystals with different doping levels were synthesized using the floating zone method, and their photoluminescence and scintillation properties were evaluated. The results showed that Cr-doped Mg4Ta2O9 single crystals exhibited broad emission bands in the near-infrared region and showed scintillation characteristics within specific wavelength ranges. Additionally, the samples with different Cr doping levels demonstrated different lower detection limits based on the dose rate response function.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. Marouf, A. C. Chami, Y. Boudouma
Summary: This study develops a Monte Carlo simulation approach to describe proton-induced secondary electron emission in solids. Theoretical modeling based on the Mott's elastic scattering cross-section and Lindhard's dielectric function was used to calculate the double differential cross-section (DDCS) of excited electrons and describe electron transport in the medium. The results for aluminum show the angular and energy distributions of backscattered electrons for incident protons with energy below 25 keV at normal incidence, and the total electron emission yield also agrees well with available measurements.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Weipeng Yan, Baojun Duan, Zijian Zhu, Yan Song, Guzhou Song, Jiming Ma, Binkang Li, Yucheng Liu
Summary: This article reports on the scintillation performance of Lithium-doped 2D (PEA)2PbBr4 perovskite single crystals synthesized at room temperature. The crystals exhibit fast decay time, high light yield, and high spatial resolution, making them highly promising for medical diagnostic applications.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
S. B. Vishwakarma, S. K. Dubey, R. L. Dubey, I. Sulania, D. Kanjilal
Summary: Investigations have been conducted on the implanted SiO2 thin film after thermal annealing using various analytical techniques. The results revealed the absence of vacancy defects, variations in vibrational modes and the formation of new structures. The photoluminescence intensity of the annealed SiO2 samples was higher, with a decrease in non-radiative defect centers and an increase in radiative Si:SiO2 interface states. Additionally, the presence of silicon nanoclusters formed after annealing resulted in an additional radiative recombination peak. Furthermore, the formation of new SiOx structures was observed after thermal annealing.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
M. Koshimizu, S. Kurashima, A. Kimura, M. Taguchi
Summary: By observing the scintillation time profiles of CeF3 under irradiations of pulsed beams with different LETs, we found that the initial decay was faster for higher LET, which is consistent with previous studies on other self-activated scintillators. This faster decay at higher LET can be explained by the competition between the scintillation caused by 5d-4f transition of Ce3+ ions and quenching due to the interaction between excited Ce3+ ions close to each other.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)
Article
Instruments & Instrumentation
Junjie Shi, Jianhong Hao, Fang Zhang, Qiang Zhao, Bixi Xue, Jieqing Fan, Zhiwei Dong
Summary: This study examined the neutralization process and beam quality of a hydrogen beam by emitting negative hydrogen ions to a hydrogen target. The findings showed that the neutralization efficiency was influenced by variables such as the transport distance, energy, and target gas density. However, the maximal neutralization efficiency was not affected by the density of the target gas or the energy of the negative hydrogen ions.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2024)