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Huang X.,Nanjing University of Aeronautics and Astronautics | Gong P.,Nanjing University of Aeronautics and Astronautics | Gong P.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Wen L.-S.,Nanjing University of Aeronautics and Astronautics | And 4 more authors.
Hedianzixue Yu Tance Jishu/Nuclear Electronics and Detection Technology | Year: 2016

This paper introduced the development of a multifunctional and wide range radiation detection system. The system used GM tube and NaI(TI) gamma spectrometer, through embedded design, experimental calibration, spectrum to dose conversion algorithm, software development and other work can achieve wide dose rate range, double parameters detection, automatic temperature drift correction, wireless data transmission and detection trajectory calibration function. The system can be equipped with unmanned rotor aircraft and other equipment for remote detection, which have a certain radiation environment. The experimental results show that the dose rate measurement error of system in the radiation field of 0.01 μGy/h~100 mGy/h is less than 8%; In 3 km distance, the upper PC can obtain the working path, the gamma ray spectrum and the dose rate. © 2016, Editorial Board of Nuclear Electronics & Detection Tech. All right reserved.


Chai H.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Ni M.,Nanjing University of Aeronautics and Astronautics | And 5 more authors.
Journal of Applied Polymer Science | Year: 2016

Novel, flexible, lead-free X-ray-shielding composites were prepared with a high-functional methyl vinyl silicone rubber (VMQ) matrix with W and Bi2O3 as filler materials. To verify the advanced properties of the lead-free material, composites with the same mass fraction of PbO were compared. With the X-ray energy ranging from 48 to 185 keV, the W/Bi2O3/VMQ composites exhibited higher X-ray-shielding properties. As the filler volume fraction decreased, the tensile strength, elongation, tear strength, and flexibility of the W/Bi2O3/VMQ composites increased. The Shore hardness of the W/Bi2O3/VMQ composites had a maximum value of 46.6 HA and was still very flexible. With decreasing filler volume fraction, the water-vapor transmission performances of the W/Bi2O3/VMQ composites increased, and the W/Bi2O3/VMQ composites also showed better water-vapor permeability. The heat-transfer properties of the W/Bi2O3/VMQ composites increased with increasing W content, and when the W content exceeded 70 wt %, the thermal conductivity of the W/Bi2O3/VMQ material was about 70.45% higher than that of the PbO/VMQ composite. © 2015 Wiley Periodicals, Inc.


Wang P.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Chai H.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
Fusion Engineering and Design | Year: 2015

The design and fabrication of shielding materials with good heat-resistance and mechanical properties is a major problem in the radiation shielding field. In this paper, based on gamma ray and neutron shielding theory, a continuous carbon-fiber reinforced Sm2O3/polyimide gamma ray/neutron shielding material was fabricated by hot-pressing method. The material's application behavior was subsequently evaluated using neutron shielding, photon shielding, mechanical tensile, and thermogravimetric analysis-differential scanning calorimetry tests. The results show that the tensile strength of the novel shielding material exceeds 200MPa, which makes it of similar strength to aluminum alloy. The material does not undergo crosslinking and decomposition reactions at 300°C and it can be used in such environments for long periods of time. The continuous carbon-fiber reinforced Sm2O3/polyimide material has a good shielding performance with respect to gamma rays and neutrons. The material thus has good prospects for use in fusion reactor system and nuclear waste disposal applications. © 2015 Elsevier B.V.


Chen F.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Huang H.,Nanjing University of Aeronautics and Astronautics | And 7 more authors.
ACS Applied Materials and Interfaces | Year: 2016

Cr/W multilayer nanocomposites were presented in the paper as potential candidate materials for the plasma facing components in fusion reactors. We used neutron reflectometry to measure the depth profile of helium in the multienergy He ions irradiated [Cr/W (50 nm)]3 multilayers. Results showed that He-rich layers with low neutron scattering potential energy form at the Cr/W interfaces, which is in great agreement with previous modeling results of other multilayers. This phenomenon provided a strong evidence for the He trapping effects of Cr/W interfaces and implied the possibility of using the Cr/W multilayer nanocomposites as great He-tolerant plasma facing materials. © 2016 American Chemical Society.


Liu J.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Chen F.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
Science China Technological Sciences | Year: 2015

Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induced vacancy formation in CLAM, F82H and α-Fe with different neutron energies and objective laws of the effect of vacancy concentration on mechanical properties of α-Fe. Damage of these typical metal engineering materials caused by neutrons is mainly displacement damage, while the displacement damage rate and the non-ionizing effect of neutrons decrease with the increase of neutron energy. The elastic modulus, yield strength, and ultimate strength of α-Fe are in the order of magnitude of GPa. However, the elastic modulus is not constant but decreases with the increase of strain at the elastic deformation stage. The ultimate strength reaches its maximum value when vacancy concentration in α-Fe is 0.2%. On this basis, decreasing or increasing the number of vacancies reduces the ultimate strength. © 2015 Science China Press and Springer-Verlag Berlin Heidelberg


Liu J.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Chen F.,Nanjing University of Aeronautics and Astronautics | And 4 more authors.
Diamond and Related Materials | Year: 2016

It is of great significance to provide theoretical guidance to the application of carbon nanotubes as adhesive materials via the investigation on their adhesion force. In this paper, molecular dynamics was adopted to investigate the adhesion force between the graphene substrate and the carbon nanotubes with varying deformation degrees and diverse types of irradiation induced defects at different temperatures. No obvious adhesion force was found between the carbon nanotube and graphene until the deformation degree of the former reached > 70%. The adhesion force would be maintained at a high level when the temperature was in the range of 280–320 K, which limited its application. Moreover, the adhesion force between carbon nanotube with vacancies and graphene substrate would decrease with increasing size of vacancies. Finally, compared with monovacancies and divacancies, Stone-Wales defects most remarkably reduced the adhesion force of carbon nanotubes. © 2016 Elsevier B.V.


Chen F.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Yang Y.,Nanjing University of Aeronautics and Astronautics | And 4 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2015

Abstract Metallic multilayer nanocomposites are known to have excellent interface self-healing performance when it comes to repairing irradiation damages, thus showing promise as structural materials for advanced nuclear power systems. The present study investigated the neutron irradiation displacement damage rate, spectra of the primary knocked-on atoms (PKAs) produced in the cascade collision, and the H/He ratio in four kinds of metallic multilayer nanocomposites (Cu/Nb, Ag/V, Fe/W, and Ti/Ta) versus neutrons' energy. Results suggest that the three neutron induced damage effects in all multilayer systems increased with the increasing of incident neutrons' energy. For fission reactor environment (1 MeV), multilayer's displacement damage rate is 5-10 × 1022 dpa/(n/cm2) and the mean PKAs energy is about 16 keV, without any noteworthy H/He produced. Fe/W multilayer seems very suitable among these four systems. For fusion reactor environment (14 MeV), the dominant damage effect varies in different multilayer systems. Fe/W multilayer has the lowest displacement damage under the same neutron flux but its gaseous transmutation production is the highest. Considering the displacement damage and transmutation, the irradiation resistance of Ag/V and Ti/Ta systems seems much greater than those of the other two. © 2015 Elsevier B.V.


Li H.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Chen F.,Nanjing University of Aeronautics and Astronautics | And 4 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2016

The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments. © 2016 Elsevier B.V. All rights reserved.


Wang P.,Nanjing University of Aeronautics and Astronautics | Wang P.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | And 4 more authors.
Nuclear Engineering and Design | Year: 2015

A novel LiF, Sm2O3, Gd2O3/carbon fibre/polyimide material was designed in order to improve the neutron absorbing performance of the spent fuel storage basket in this paper. The volume fraction of three kinds of neutron absorbers (LiF, Sm2O3and Gd2O3) in polyimide was optimised by Monte Carlo method. Calculation results showed that the novel neutron-absorbing material, in which the volume ratio of LiF, Sm2O3and Gd2O3 was 1:2:13, can achieve the best absorption capacity. Based on the calculated results, the basket material was fabricated by compression moulding, and its mechanical behaviour, thermal behaviour, and irradiation resistant behaviour were evaluated, respectively. The experimental results proved that the tensile strength of the novel neutron-absorbing material was between 195 and 346 MPa and the maximum service temperature was up to 300 °C. Gamma irradiation dose was limited to 160 kGy, the bending strength of the material kept increasing from 10 to 19 MPa. © 2014 Elsevier B.V. All rights reserved.


Chen F.,Nanjing University of Aeronautics and Astronautics | Tang X.,Nanjing University of Aeronautics and Astronautics | Tang X.,Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering | Yang Y.,Nanjing University of Aeronautics and Astronautics | And 5 more authors.
Journal of Nuclear Materials | Year: 2016

We investigated the radiation damage resistance of the Fe/Ni multilayer nanocomposites by molecular dynamics. In the paper, two types of interface configuration with different orientation relationship were constructed. Their morphology evolution and number of final surviving defects induced by cascade collisions were discussed respectively. The interfaces of the two types of Fe/Ni multilayers kept distinct during the long-time relaxation before cascade. The comparison of surviving defects number produced by PKA with 5 keV at 100 K showed that the Fe/Ni multilayers have greater radiation tolerance than that of the bulk materials. However, the orientation relationship of the interface influences the defects self-healing capability greatly when the multilayers are irradiated by higher energy PKA or at high temperature. The radiation damage resistance of the Nishiyama - Wassermann type Fe/Ni multilayers which have larger lattice misfit is more stable than that of the Kurdjumov - Sachs type. © 2015 Elsevier B.V.

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