Effect of vacancy defect clusters on the optical property of the aluminium filter used for the space solar telescope

We investigate the microstructures of the pure aluminium foil and filter used on the space solar telescope, irradiated by photons with different doses. The vacancy defect clusters induced by proton irradiation in both samples are characterized by transmission electron microscopy, and the density and the size distribution of vacancy defect clusters are determined. Their transmittances are measured before and after irradiating the samples by protons with energy E = 100 keV and dose = 6 × 10 11 /mm 2 . Our experimental results show that the density and the size of vacancy defect clusters increase with the increase of irradiation doses in the irradiated pure aluminium foils. As irradiation dose increases, vacancies incline to form larger defect clusters. In the irradiated filter, a large number of banded void defects are observed at the agglomerate boundary, which results in the degradation of the optical and mechanical performances of the filter after proton irradiation.     

Ni离子辐照国产ZIRLO合金的辐照性能研究

国产ZIRLO合金是CAP1400重要的燃料包壳管候选材料之一，因此需要在使用前对该材料进行辐照性能考验。研究了国产ZIRLO合金的辐照性能随辐照温度和损伤剂量的变化。辐照实验在中国原子能科学研究院HI-13串列加速器上，采用80 MeV的Ni离子进行，辐照产生的损伤采用透射电子显微镜、能量色散谱和纳米压痕法等方法表征。国产ZIRLO合金在300℃经10 dpa损伤剂量辐照后观察到均匀分布的析出颗粒，同样剂量在700℃辐照析出颗粒数目减少，析出相的主要成分为Nb。辐照后出现硬化现象，辐照损伤剂量越大，硬化程度越高；随着辐照温度升高，辐照硬化呈减小趋势。The domestic ZIRLO is a promising candidate of cladding materials for CAP1400. It is necessary to test its radiation properties before its use. In this paper, the radiation properties of the domestic ZIRLO have been studied as functions of irradiation temperature and dose respectively. The experiment was performed at the HI-13 tandem accelerator of China Institute of Atomic Energy by using 80 MeV Ni ions at different temperature and different dose. The transmission electron microscopy, electron dispersive spectroscopy and nano-indentation were used to characterize the radiation damage. The experimental results show that the precipitates are uniformly distributed at 10 dpa and 300℃, while at 700℃ the number of precipitates is reduced. Among all the precipitates, Nbisthe dominant element. Hardening phenomenon was also observed after irradiation, the higher the radiation dose, the higher the degree of hardening, and it illustrates a decreasing tendency with the increasing of the irradiation temperature.     

0.56GeV C6+离子在YIG上的辐照效应

用穆斯堡尔谱学、正电子湮没技术和高分辨电子显微镜等方法研究了高能碳离子在石榴石铁氧体材料上的辐照效应,辐照效应引起材料微结构变化源于缺陷和缺陷团,导致缺陷周围磁结构变化,内场趋向各向同性,辐照并且使得晶胞参数变大;引起材料磁性能变化源于由于O~2—空位形成而使超交换场降低,从而减小超精细场。 The vacancies and vacancy clusters induced by the irradiation lead to the change of themagnetic structure around the defects. The reduction of the hyperfine magnetic field is caused by thelower superexchange field due to the formation of the O~(2-) vacancies. The change of direction of thehyperfine field has been also observed in Mossbauer spectra. On the other hand, the X-raydiffraction showed that the defects give rise to an increase of the lattice constant of the samples.     

Characterization of Microstructure and Stability of Precipitation in SIMP Steel Irradiated with Energetic Fe Ions

A type of home-made reduced activation martensitic steel, high silicon(SIMP) steel, is homogeneously irradiated with energetic Fe ions to the doses of 0.1, 0.25 and 1 displacement per atom(dpa), respectively, at 300°C and1 dpa, at 400℃. Microstructural changes are investigated in detail by transmission electron microscopy with cross-section technique. Interstitial defects and defect clusters induced by Fe-ion irradiation are observed in all the specimens under different conditions. It is found that with increasing irradiation temperature, size of defect clusters increases while the density drops quickly. The results of element chemical mapping from the STEM images indicate that the Si element enrichment and Ta element depletion occur inside the precipitates in the matrix of SIMP steel irradiated to a dose of 1 dpa at 300℃. Correlations between the microstructure and irradiation conditions are briefly discussed.     

Effect of tellurium(Te~(4+)) irradiation on microstructure and associated irradiation-induced hardening

The GH3535 alloy samples were irradiated using 15-Me V Te~(4+) ions at 650℃ to a dose of 0.5, 3.0, 10, and 20 dpa, respectively. The Te atoms distribution and microstructure evolution were examined by electron probe microanalysis(EPMA)and transmission electron microscopy(TEM). The nano-indenter was then used to measure the nano-hardness changes of samples before and after irradiation. TEM results showed the formation of dislocation loops in the irradiated samples.Their mean diameters increase with the increase of irradiation dose and tends to be saturated when irradiation dose exceeds10 dpa. The ratio of yield strength increments calculated by dispersed barrier hardening(DBH) model is basically consistent with that of nano-hardness increments measured by nano-indenter. In addition, the relationship between the nano-hardness increments and dpa for the GH3535 alloy irradiated by Te ions has been revealed in the study.     

γ辐照后硼硅酸盐玻璃的吸收光谱研究

玻璃固化体是用来固化放射性废物的硅酸盐。作为放射性废物处理的第一道工程屏障，它的耐辐照性能尤其引人注目。本工作使用硼硅酸盐玻璃模拟玻璃固化体材料，用不同剂量的γ射线辐照硼硅酸盐玻璃模拟天然放射性对固化体的辐照损伤。通过测量和分析辐照后硼硅酸盐玻璃的吸收光谱，证实了辐照后在玻璃中产生了E'缺陷，非桥氧空位色心、过氧自由基以及过桥氧联接等缺陷。此外，还得出了不同微观结构随吸收剂量的演化关系。对于辐照后产生的缺陷，它们的浓度都随吸收剂量的增加而增大。同时，发现玻璃在辐照后其吸收光谱的带隙随着剂量的增加而逐渐变窄；而当吸收剂量大于等于105 Gy时，玻璃的带隙则达到饱和值。Vitrification is one kind of silicates which is used for immobilization of high-level waste (HLW). As the first engineered barrier of HLW disposition, its anti-irradiation characteristic is particularly noticeable. Vitrification is replaced by borosilicate glass to investigate radiation effect, and the irradiation damage generated by natural radioactivity in vitrification is simulated by different doses gamma rays on borosilicate glass. By measuring and analyzing the absorption spectrum of irradiated borosilicate glasses, it is confirmed that E'defect, non-bridging oxygen hole center, peroxy dangling bond and bridge oxygen link, etc. are induced in borosilicate glass after irradiation. Furthermore, the relations between the defects and absorbed doses are shown. For the concentrations of these defects induced by irradiation, all of them increase with absorbed dose. Meanwhile, absorption band gap in borosilicate glass after irradiation decreases with absorbed dose and the band gap becomes saturated when absorbed dose is equal to or greater than 105 Gy.     

12C6+离子束辐照番茄种子当代效应

利用辐射能量为80 MeV/u 的12C6+重离子束辐照番茄种子, 辐照剂量分别为30, 60, 90, 120和160 Gy研究其对番茄M1代的生物学效应。结果表明, 随着辐照剂量的增大, 番茄的发芽率和成苗率降低, 且成苗率明显低于发芽率, 发现辐照损伤主要抑制了根的生长; MDA和脯氨酸含量变化的总体趋势为随着辐照剂量的增大先升后降再升高, 说明高剂量C离子辐照对生物膜造成更严重的损伤; APX活性随着辐照剂量的增大呈先升后降再升高的趋势, 表明APX在清除活性氧中起主要作用; POD和SOD活性的总体趋势是随着辐照剂量的增大而降低, 且明显低于对照组。综合分析表明, 12C6+重离子束辐照番茄种子, 对M1代具有明显的损伤效应, 高剂量辐照对番茄种子造成的损伤更大, 使酶的活性降低, 抑制植株生长。 To investigate the M1 biological effects of heavy ions irradiation on Lycopersicon esculentum Mill., its seeds were irradiated by 12C6+heavy ions (80 MeV/u) with the dosages of 30, 60, 90, 120 and 160 Gy respectively . The results showed that with doses increased gradually, germination rate and seedling rate of Lycopersicon esculentum Mill. were decreased, and the latter was lower than the former, mainly due to the inhibition of root growth. The irradiation increased the content of MDA and proline evidently, showing irradiation could damage biomembrane, and also decreased the activities of POD and SOD with distinct inhibition pattern. However, the low dose and high dose irradiation promoted APX activity, illustrating APX was induced to protect irradiation injury. In brief, exposure to 12C6+ heavy ions had obvious injury effects on the seeds of Lycopersicon esculentum Mill.. Heavy ions irradiation damaged biomembrane, inhibited activities of enzymes, and finally inhibited the growth of the first generation of these seeds.     

碳化硅中惰性气体离子辐照引起缺陷的研究

综述了有关碳化硅材料中惰性气体离子引起辐照缺陷研究的进展。包括借助多种方法对氦离子辐照的碳化硅中氦泡集团形成的剂量阈值的实验研究，基于过冷固体假设对氦泡阈值的理论解释，不同剂量氦泡的两种形态及其机理的研究，以及重惰性气体离子（Ne，Xe）辐照下缺陷演化的特点。This paper gives a review of our recent studies on the defect production in silicon carbide induced by energetic inert-gas-ion irradiation. The work includes the study of the dose threshold for helium bubble formation by combining TEM, RBS-channeling and PAS, the theoretical analysis of the dose threshold for bubble formation based on the Frozen-Matrix assumption, two types of bubble arrangement at different dose regions and the study of damage um-ion production behavior in the case of irradiation with heavier inert-gas-ions （ Ne, Xe） as a comparison to heliirradiation.     

III-V族化合物半导体材料的高能重离子辐照效应

用高能（５００ＭｅＶ）Ｎｅ离子束对ＧａＡｓ和ＩｎＰ进行了辐照，用ＭｏｎｔｅＣａｒｌｏ模拟、正电子湮没谱学以及红外光谱研究了辐照产生的缺陷特性．结果表明，在未辐照的样品中存在单空位，经辐照后，可在样品中产生单空位；当剂量较大时，还会形成双空位甚至尺寸较大的空洞．红外光谱测量发现，在辐照后的ＧａＡｓ样品中有非晶区形成．此外，辐照在样品中还产生了反位缺陷ＧａＡｓ和ＩｎＰ以及受主杂质ＺｎＩｎ．对经１０１４ｉｏｎｓ／ｃｍ２剂量辐照的ＩｎＰ进行了光学实验，在辐照后的ＩｎＰ材料中发现了亚稳态中心． Both GaAs and InP were irradiated by high energy (500 MeV) Ne ions. The Monte Carlo simulation, positron annihilation and IR spectroscopy were used to study the radiation induced defects. The result showed that monovacancies existed in as grown samples, but more monovacancies were introduced, after Ne ions irradiation, and with increasing radiation dose, divacancies were formed, and eventually large voids were observed. The IR measurement for irradiated GaAs samples confirmed the...     

电子辐照改性PAN/PEO基体凝胶电解质对染料敏化太阳电池性能的提高

采用电子束（EB）对聚丙烯腈/聚氧化乙烯（PAN/PEO）凝胶电解质进行了剂量为13～260 kGy的辐照, 并对辐照改性的电解质组装的染料敏化太阳电池(DSSC)进行了性能测量。 结果表明, 改性后的DSSC的光电转化效率比改性前的高; 并且随EB辐照剂量的增加, DSSC效率先迅速增加(0～65 kGy), 然后缓慢减小(65～130 kGy)直至趋于一个平衡值(130～260 kGy)。 提升DSSC效率的最佳辐照剂量为65 kGy, 此时效率提高了约36%。 对比DSSC短路电流、 开路电压和填充因子随辐照剂量的变化, 发现DSSC效率的提高主要是由短路电流的提高引起的。 测量表明, 辐照改性后的DSSC时间稳定性得到了改善, 并且辐照剂量越高, 稳定性的改善越明显。 In this work, PAN/PEO (polyacrylonitrile/polyethylene oxide) based gel electrolyte was irradiated by electron beam (EB) with dose from 13 to 260 kGy. Then, DSSC (dye sensitized solar cell) was fabricated by the irradiated electrolyte and characterized. The results show that the efficiency of the DSSC fabricated by irradiated electrolyte is promoted comparing with DSSC fabricated by un irradiated electrolyte. And with irradiation dose increasing, the DSSC efficiency increases rapidly at first (0～65 kGy), then, drops down slowly (65～130 kGy), finally trends to a stable value (130～260 kGy). It indicates that there is an optimal irradiation dose, at which the promotion of DSSC efficiency is the highest, approximate 36%. Observed from the change of short circuit current, open circuit voltage and fill factor, short circuit current promotion by EB irradiation is found to be the main reason of DSSC performance promotion. The time stability measurement of the DSSC indicates that EB irradiation on PAN/PEO electrolyte reduces the loss of efficiency and the limiting effects become more apparent as the irradiation dose increases.     

强流脉冲电子束作用下金属纯Cu的微观结构状态——空位簇缺陷及表面微孔结构

利用强流脉冲(HCPEB)电子束技术对多晶纯Cu进行了辐照处理,并利用透射电镜对HCPEB诱发的空位簇缺陷进行了表征.实验结果表明,HCPEP辐照金属可在纯Cu表层诱发大量的过饱和空位,并形成四方形空位胞及空位型位错圈和堆垛层错四面体(SFT),HCPEB瞬间的加热和冷却诱发的幅值极大的应力和极高的应变导致的整个原子平面的位移是空位簇缺陷形成的主要原因.此外,扫描电镜分析表明HCPEB辐照可以在纯Cu表面形成高密度、弥散分布和尺寸细小的微孔.过饱和空位或空位团簇沿晶体缺陷向表面扩散、凝聚是表面微孔形成的根     

质子辐照对纯铝薄膜微观结构的影响

利用透射电子显微镜(TEM)详细分析了不同剂量的质子辐照纯铝薄膜样品的微观结构, 质子的能量E=160 keV.实验表明，质子辐照能够在Al薄膜中诱发空位位错圈，在实验范围内，位错密度随辐照剂量的增加而增加；质子辐照在1×10¹¹—4×10¹¹/mm²范围内随辐照剂量的增加，位错圈数量密度以及位错圈尺寸都随之增加.在较高剂量6×10¹¹/mm²辐照下，位错圈数量密度减小，但其尺寸显著 关键词： 质子辐照 空位簇缺陷 位错圈 微观结构     

Kinetic analysis of dynamic point defect pinning in aluminium initiated by strain rate changes

The role of point defect production during deformation was examined by sealing the vacancy sinks in the grain boundaries with solutes to magnify its effect upon instantaneous strain-rate changes. AA1100 aluminium sheets were thermal-mechanically treated to result in a grain size of about 25 µm and in grain boundaries that were not capable of acting as efficient vacancy sinks. Tensile tests at various temperatures ranging from 78 to 300 K showed that above 195 K, the pinning effect could be quantitatively analysed. A rate equation analysis for mono- and di-vacancy recovery was adopted to perform fits to the deduced change in flow stress with time after strain-rate change from which apparent activation energies were derived. This examination indicates that the migrating species are predominantly di-vacancies. It is concluded that point-defect atmospheres have the capacity to glide in unison with mobile dislocations and hence are sensitive to the magnitude of the strain rate and temperature.     

On the interaction between a vacancy and self-interstitial atom clusters in metals

Atomic-scale computer simulation is used to study the interaction between a vacancy and a cluster of self-interstitial atoms in metals with hcp, fcc and bcc crystal structure: α-zirconium, copper and α-iron. Effects of cluster size, atomic structure, dislocation nature of the cluster side and temperature are investigated. A vacancy can recombine with any interstitial in small clusters and this does not affect cluster mobility. With increasing sizes clusters develop dislocation character and their interaction with vacancies depends on whether the cluster sides dissociate into partial dislocations. A vacancy recombines only on undissociated sides and corners created with undissociated segments. Vacancies inside the cluster perimeter do not recombine but restrict cluster mobility. Temperature enhances recombination by either increasing the number of recombination sites or assisting vacancy diffusion towards such sites. The results are discussed with relevance to differences in irradiation microstructure evolution of bcc, fcc and hcp metals and higher level theoretical modelling techniques.     

不锈钢辐射损伤随温度和剂量的变化(英文)

用重离子辐照模拟和正电子湮没寿命技术研究了改进型316L不锈钢在21 和33 dpa辐照剂量下的辐照损伤在室温到802 °C温度范围随辐照温度变化和室温下0—100 dpa剂量范围随辐照剂量变化. 在580 °C左右实验观察到辐照肿胀峰， 在21 和33 dpa辐照剂量下相应的空位团分别由14和19个空位组成， 尺度分别为0.68 和0.82 nm. 空位团尺寸随辐照剂量增加， 在100 dpa时空位团由8个空位组成， 尺度为0.55 nm. 实验结果表明， 在改进型316L不锈钢中辐照损伤随辐照温度变化更灵敏.     

Interaction of point defects with twin boundaries in Au： A molecular dynamics study

The molecular dynamics simulation technique with many-body and semi-empirical potentials （based on the embedded atom method potentials） has been used to calculate the interactions of point defects with （1 1 1）, （1 1 3）, and （1 2 0） twin boundaries in Au at different temperatures. The interactions of single-, di-, and tri-vacancies （at on- and off-mirror sites） with the twin interfaces at 300 K are calculated. All vacancy clusters are favorable at the on-mirror arrangement near the （1 1 3） twin boundary. Single- and di-vacancies are more favorable at the on-mirror sites near the （1 1 l） twin boundary, while they are favorable at the oft-mirror sites near the （1 2 0） twin boundary. Almost all vacancy clusters energetically prefer to lie in planes closest to the interface rather than away from it, except for tri-vacancies near the （1 2 0） interface at the off-mirror site and for 3.3 and 3.4 vacancy clusters at both sites near the （1 1 1） interface, which are favorable away from the interface. The interaction energy is high at high temperatures.     

强流脉冲电子束辐照诱发纯钼表面的损伤效应及结构缺陷

利用强流脉冲电子束（HCPEB）装置对纯钼表面进行辐照处理,并利用X射线衍射仪,扫描电子显微镜（SEM）、透射电子显微镜（TEM）详细分析了辐照表面的微观结构和损伤效应. 1次HCPEB辐照后,纯钼表层积聚了极大的残余应力,多次辐照后表面未融化区域出现大量绝热剪切带,且局部区域发生开裂. 微观结构分析显示,辐照后材料表面形成发散状的位错组态和大量空位簇缺陷;绝热剪切带内部是尺寸为1 μm 左右等轴状的再结晶晶粒. 剪切带造成的材料表面局部软化以及间隙原子偏聚于晶界是材料发生开裂的主要原因. 另外,表面熔化区域可形成尺寸为20 nm左右的纳米晶. 关键词： 强流脉冲电子束 纯钼 绝热剪切带 空位簇缺陷     

Evolution of ion-irradiated point defect concentration by cluster dynamics simulation

The relationship between ions irradiation and the induced microstructures(point defects, dislocations, clusters, etc.)could be better analyzed and explained by simulation. The mean field rate theory and cluster dynamics are used to simulate the effect of implanted Fe on the point defects concentration quantitatively. It is found that the depth distribution of point defect concentration is relatively gentle than that of damage calculated by SRIM software. Specifically, the damage rate and point defect concentration increase by 1.5 times and 0.6 times from depth of 120 nm to 825 nm, respectively. With the consideration of implanted Fe ions, which effectively act as interstitial atoms at the depth of high ion implantation rate, the vacancy concentration C_v decreases significantly after reaching the peak value, while the interstitial atom concentration C_i increases significantly after decline of the previous stage. At the peak depth of ion implantation, C_v dropped by 86%, and C_i increased by 6.2 times. Therefore, the implanted ions should be considered into the point defects concentration under high dose of heavy ion irradiation, which may help predict the concentration distribution of defect clusters, further analyzing the evolution behavior of solute precipitation.     

Point Defect Production Under High Internal Stress Without Dislocations in Ni and Cu

Kiritani et al. have observed a large number of small vacancy clusters without dislocations at the tip of torn portions of fcc metals such as Au, Ag, Cu and Ni. Small vacancy clusters, rather than dislocation cell structures, have also been observed after high-speed compressive deformation, suggesting the possibility of plastic deformation without dislocations. In this paper, in order to investigate the mechanism of deformation without dislocations, change in formation energy of point defects under high internal stress was estimated by computer simulation. Elastic deformation up to - 20% strain was found to provide a remarkable lowering of formation energy of point defects. For example, when Ni is subjected to elastic strain, the formation energy of an interstitial atom decreases to 40% that without strain and the formation energy of a vacancy decreases to 51% that without strain. The number of point defects formed under thermal equilibrium during deformation was evaluated. The number was judged to be insufficient for explaining the formation of vacancy clusters as observed in experiments.