激光靶丸全表面检测与功率谱特征评价

本工作基于靶丸全球面测量的经纬迹线法,应用由原子力显微镜、精密回转气浮轴系及辅助转位轴系等组成的靶丸表面形貌测量系统,对直径0.34mm的空心塑料靶丸表面进行了测量实验。实验选择了圆周9条经圆(间隔20°),每个经圆方向上纬圆间隔10μm,最大偏移20μm的方案,获取了靶丸全球面的经纬测量迹线,并对测量结果进行了模数-功率谱特征曲线和表面均方根粗糙度的分析。     

W/BDD薄膜电极制备及其电化学性能研究

利用化学气相沉积（CVD）法研制了一种钨基硼掺杂金刚石（W/BDD）薄膜电极,通过扫描电镜和Raman光谱考察了W/BDD薄膜电极的性能,通过电化学方法测定了其在LiCl-KCl熔盐中的电化学窗口和电化学性能。结果表明,研制的W/BDD薄膜电极的BDD薄膜有较好的微观结构;W/BDD薄膜电极在LiCl-KCl熔盐中的电化学窗口约为3.5 V(-2.5～1.0 V,相对于Ag/AgCl参比极电位);电解过程中,氧离子不与W/BDD薄膜电极表面BDD薄膜层的碳反应,直接被氧化为氧原子;长时间电解不会改变电极表面薄膜层的形貌和结构。     

W/BDD薄膜电极制备及其电化学性能研究

利用化学气相沉积(CVD)法研制了一种钨基硼掺杂金刚石(W/BDD)薄膜电极,通过扫描电镜和Raman光谱考察了W/BDD薄膜电极的性能,通过电化学方法测定了其在LiCl-KCl熔盐中的电化学窗口和电化学性能。结果表明,研制的W/BDD薄膜电极的BDD薄膜有较好的微观结构;W/BDD薄膜电极在LiCl-KCl熔盐中的电化学窗口约为3.5 V(-2.5～1.0 V,相对于Ag/AgCl参比极电位);电解过程中,氧离子不与W/BDD薄膜电极表面BDD薄膜层的碳反应,直接被氧化为氧原子;长时间电解不会改变电极表面薄膜层的形貌和结构。     

三步法接枝聚合苯胺制备抗静电织物

结合辐射接枝聚合和原位氧化还原聚合,通过三步处理,将聚苯胺(PANI)共价接枝到普通棉织物上,得到具有较好导电性的导电织物。通过红外光谱(FT-IR)和X-射线光电子能谱(XPS)表征三步接枝过程中棉织物的化学结构变化,证明了PANI被成功接枝到棉织物表面。用扫描电子显微镜(SEM)以及接触角(CA)表征处理过程中棉织物的微观形貌及表面性质变化。结果表明,接枝后棉纤维表面完全被PANI接枝层所覆盖,且所得织物的表面疏水性明显增大。接枝棉织物的导电性测试证明,材料具有较好的导电性能,当PANI接枝率为10.2%(重量分数)时,其表面电阻可降到108?/?的量级,达到了抗静电织物的要求。     

背散射分析测定锗(锂漂移)表面的氟化钙薄膜厚度

在制造同轴锗(锂漂移)探测器时,为了减少表面漏电流、降低噪声,需要在锗表面生长一层有一定厚度的氟化钙复盖膜。因此,在选择加工工艺条件时,要求测量此层的厚度。 背散射分析一般不适合于测量重基体表面上的轻材料薄膜.我们用测量基体背散射能谱的位移量的方法,测出了锗(锂漂移)表面上氟化钙薄膜的厚度。     

激光核聚变靶表面几何参数扫描探针测量技术

应用改造的原子力显微镜(AFM)作为传感系统,配合精密回转气浮轴系和三维微定位装置,实现了对激光核聚变靶球圆周方位形状误差的精密测量.采用该测量技术获得的靶球表面几何参数的测量数据及分析结果可为制靶工艺提供检测手段,并为激光打靶实验提供准确的靶球表面形貌参数.     

硼缓冲注入层对氮化硼薄膜生长的影响

采用射频磁控溅射法在注硼的硅和高速钢基体上沉积制备c-BN薄膜,采用红外光谱(Infrared spectra,IR)、X射线光电子能谱(X-ray photoelectron spectrum,XPS)和原子力显微镜(Atomicforce microscopy, AFM)等分析方法对沉积的薄膜进行了表征分析.实验结果表明:硅基体上离子注硼有利于c-BN薄膜内应力的降低;合适的注硼量注入高速钢基体有利于c-BN的生成和薄膜内应力的降低.AFM分析表明,注硼处理的高速钢基体上沉积的薄膜表面形貌平整,结晶性较好.此外也采用XPS方法对硅和高速钢基体硼过渡层进行了成分与组织结构分析,探索研究了硼缓冲层对c-BN薄膜生长的影响.     

激光核聚变靶表面几何参数扫描探针测量技术

应用改造的原子力显微镜（AFM）作为传感系统，配合精密回转气浮轴系和三维微定位装置，实现了对激光核聚变靶球圆周方位形状误差的精密测量。采用该测量技术获得的靶球表面几何参数的测量数据及分析结果可为制靶工艺提供检测手段，并为激光打靶实验提供准确的靶球表面形貌参数。     

SOI 硅微剂量探测器对中子和伽马辐射场线能谱测量的GEANT4模拟研究

绝缘体上硅(SOI)硅微剂量测量系统可以通过测量中子和伽马混合辐射场的线能谱来获取不同类型辐射的剂量当量贡献。本文根据SOI硅微剂量探测器物理设计,采用GEANT4软件建模对Cf-252中子和伽马混合辐射场及Co-60伽马辐射线能谱测量进行蒙特卡罗模拟,并进一步分析了SOI探测器转换层对伽马线能谱测量的影响。结果表明,SOI硅微剂量探测器能够区分中子和伽马的剂量贡献,并且伽马线能谱峰值随着转换层厚度发生变化,有可能利用该特性实现不同贯穿深度下伽马辐射剂量贡献的测量。模拟分析结果可为SOI硅微剂量探测器设计及应用提供参考。     

电沉积法铀辐照靶性能检测技术研究

对电沉积铀靶进行了系统的检测技术研究.通过分光光度法测其电镀收率;运用扫描电子显微镜、X射线能谱和红外光谱对电沉积层的表面形貌、微区成分和结构组成进行分析和表征;采用低频振动试验检测铀沉积层的牢固性;考虑到入堆辐照的安全性,计算了靶件的发热量并用γ谱仪测试了靶件中铀分布的均匀性.介绍了这些无损检测技术的方法和检测结果.     

Modelling effect of magnetic field on material removal in dry electrical discharge machining

One of the reasons for increased material removal rate in magnetic field assisted dry electrical discharge machining(EDM) is confinement of plasma due to Lorentz forces.This paper presents a mathematical model to evaluate the effect of external magnetic field on crater depth and diameter in single-and multiple-discharge EDM process.The model incorporates three main effects of the magnetic field,which include plasma confinement,mean free path reduction and pulsating magnetic field effects.Upon the application of an external magnetic field,Lorentz forces that are developed across the plasma column confine the plasma column.Also,the magnetic field reduces the mean free path of electrons due to an increase in the plasma pressure and cycloidal path taken by the electrons between the electrodes.As the mean free path of electrons reduces,more ionization occurs in plasma column and eventually an increase in the current density at the inter-electrode gap occurs.The model results for crater depth and its diameter in single discharge dry EDM process show an error of 9%-10%over the respective experimental values.     

Boat sampling and inservice inspections of the reactor pressure vessel weld No. 4 at Kozloduy NPP, Unit 1

The paper deals with reactor pressure vessel (RPV) boat sampling performed at Kozloduy Nuclear Power Plant, Unit 1, from August to November 1996. Kozloduy NPP, Unit 1 has no reactor vessel material surveillance program. Changes in the material fracture toughness resulting from the fast neutron irradiation which cannot be monitored without removal of the vessel material. Therefore, the main objective of the project was to cut samples from the RPV wall in order to obtain samples of the RPV material for further structural analyses. The most critical area, i.e. weld No. 4 was determined as a location for boat sampling. Replication technique was applied in order to obtain precise determination of the weld geometry necessary for positioning of the cutting tool prior to boat sampling, and determination of divot depth left after boat sampling and grinding of sample sites. Boat sampling was performed by electrical discharge machining (EDM). Grinding of sample sites was implemented to minimize stress concentration effects on sample sites, to eliminate surface irregularities resulting from EDM process, and to eliminate recast layer on the surface of the EDM cut. Ultrasonic, liquid penetrant, magnetic particles, and visual examinations were performed after grinding to establish baseline data in the boat sampling area. The project preparation activities, apart from EDM process, and the site organization lead was entrusted to INETEC. The activities were funded by the PHARE program of the European Commission.     

Experimental Study on Surface Dielectric Barrier Discharge Plasma Actuator with Different Encapsulated Electrode Widths for Airflow Control at Atmospheric Pressure

The surface dielectric barrier discharge(SDBD) plasma actuator has shown great promise as an aerodynamic flow control device. In this paper, the encapsulated electrode width of a SDBD actuator is changed to study the airflow acceleration behavior. The effects of encapsulated electrode width on the actuator performance are experimentally investigated by measuring the dielectric layer surface potential, time-averaged ionic wind velocity and thrust force. Experimental results show that the airflow velocity and thrust force increase with the encapsulated electrode width. The results can be attributed to the distinct plasma distribution at different encapsulated electrode widths.     

Study on Glow Discharge Plasma Used in Polyester Surface Modification

To achieve an atmospheric pressure glow discharge(APGD)in air and modify the surface of polyester thread using plasma,the electric field distribution and discharge characteristics under different conditions were studied.We found that the region with a strong electric field,which was formed in a tiny gap between two electrodes constituting a line-line contact electrode structure,provided the initial electron for the entire discharge process.Thus,the discharge voltage was reduced.The dielectric barrier of the line-line contact electrodes can inhibit the generation of secondary electrons.Thus,the transient current pulse discharge was reduced significantly,and an APGD in air was achieved.We designed double layer line-line contact electrodes,which can generate the APGD on the surface of a material under treatment directly.A noticeable change in the surface morphology of polyester fiber was visualized with the aid of a scanning electron microscope(SEM).Two electrode structures–the multi-row line-line and double-helix line-line contact electrodes–were designed.A large area of the APGD plasma with flat and curved surfaces can be formed in air using these contact electrodes.This can improve the efficiency of surface treatment and is significant for the application of the APGD plasma in industries.     

Study on water treatment effect of dispersion discharge plasma based on flowing water film electrode

To improve the utilization rate of plasma active species,in this study,a closed non-uniform air gap is formed by a flowing water film electrode and a sawtooth insulating dielectric layer to realize the diffuse glow discharge in the atmosphere.Firstly,the electric field distribution characteristics of non-uniform air gap in the sawtooth dielectric layer are studied,and the influence of aspect ratio on the characteristics of diffuse discharge plasma is discussed.Subsequently,the effects of wire mesh,the inclination angle of the dielectric plate,and liquid inlet velocity on the flow characteristics of the water film electrode are analyzed.The results show that the non-uniform electric field distribution formed in the sawtooth groove can effectively inhibit the filamentous discharge,and the 1 mm flowing water film is directly used as the electrode,and high-active plasma is formed directly on the lower surface of the water film.In addition,a plasma flowing water treatment device is built to treat the methyl orange solution and observe its decolorization effect.The experimental results show that after 50 min of treatment,the decolorization rate of the methyl orange solution reaches 96％,which provides a new idea for industrial applications of wastewater treatment.     

高温气冷堆用含硼碳对水蒸气的吸附特性研究

高温气冷堆中使用了大量的碳材料,其中含硼碳（BC）因其优秀的物理特性而被大量用于堆芯的结构材料。BC是一种典型的多孔材料,暴露于空气中会吸附水分等杂质,其对水蒸气的吸附和脱附特性将直接影响初装堆芯的除湿过程。通过动态吸附和脱附实验详细测定了BC的水蒸气吸附等温线,使用低相对湿度的吸附数据拟合BET方程,并得到高相对湿度下的BET预测值。研究结果表明,水蒸气在BC表面属于多层物理吸附,脱附曲线较吸附曲线有一定的滞后,水蒸气能深入进材料内部,这也导致在较高的相对湿度下很难达到吸附和脱附平衡。     

Aerosol,Gas, and Swarf Production during Underwater Cutting of Reactor Core Internals Using Electron Discharge Machining

Secondary products (aerosol, gas and swarf) are released in the work area when cutting nuclear reactor components are underwater during component replacement. We studied the characteristics and behavior of the secondary products produced during cutting of highly radioactive metals using electric discharge machinery (EDM) underwater. The ratio of the weight of the aerosol produced to the melted weight of a workpiece that was cut using EDM, both with a Ag/W alloy electrode and a carbon electrode, was about 1 × 10^?3. The aerosol had a high concentration of manganese with a high vapor pressure. The production ratio was expressed as the aerosol production rate (ppm) = ?4:6 × 10^?2 Tb + 1:4 × 10² (Tb: boiling point (K)). The EDM cutting produced metal vapors which condensed into particles. Air-borne nickel carbonyl was produced during the EDM cutting of nickel and carbon monoxide with a carbon electrode, and a high efficiency particulate air filter and a charcoal filter were used effectively. In the case of a Ag/W electrode, the swarf contained oxide particles of around 20 mm and hydroxide particles with a diameter of around 10 mm. The water clean-up system was able to purify water with over 95% filtration efficiency using a 1 μm pore-pleated filter cartridge.     

Boron carbide as a target for the SPES project

Within the framework of the research on targets for the SPES project (Selective Production of Exotic Species), porous boron carbide (B₄C) based materials were produced from the carbothermal reduction of boric acid and two different carbon sources, i.e. citric acid and phenolic resin. Samples composition and microstructural morphology were studied by means of X-ray diffraction spectrometry (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS). The amount of total porosity was obtained from the comparison between the theoretical density and the measured bulk density. To better characterize the material microstructure, nitrogen physisorption measurements were performed in order to obtain data about the type of generated porosity and the specific surface area of the samples. Analysis performed on the samples show that after the final thermal treatment they are composed of boron carbide and residual free carbon, whose quantity is related to the processes involved in the two synthesis. Remarkable differences in the overall weight loss have been noticed for the two different reactions, resulting in different densities and pore size distributions, but in both cases similar values of specific surface area (SSA) were obtained.     

Enhanced by Dielectric Barrier Discharge Plasma Pretreatment Irradiated by High-Intensity Pulsed Ion Beam

In order to develop a more economical pretreatment method for electroless nickel plating, a dielectric barrier discharge (DBD) plasma at atmospheric pressure was used to improve the hydrophilicity and adhesion of poly (ethylene terephthalate) (PET) nonwoven fabric. The properties of the PET nonwoven fabric including its liquid absorptive capacity (WA), aging behavior, surface chemical composition, morphology of the surface, adhesion strength, surface electrical resistivity and electromagnetic interference (EMI)- shielding effectiveness (SE) were studied. The liquid absorptive capacity (WA) increased due to the incorporation of oxygen-containing and nitrogen-containing functional groups on the surface of PET nonwoven fabric after DBD air-plasma treatment. The surface morphology of the nonwoven fibers became rougher after plasma treatment. Therefore, the surface was more prone to absorb tin sensitizer and palladium catalyst to form an active layer for the deposition of electroless nickel. SEM and X-ray diffraction (XRD) measurements indicated that a uniform coating of nickel was formed on the PET nonwoven fabric. The average EMI-SE of Ni-plating of PET nonwoven fabric maintained a relatively stable value (38.2 to 37.3 dB) in a frequency range of 50 to 1500 MHz. It is concluded that DBD is feasible for pretreatment of nonwoven fabric for electroless nickel plating to prepare functional material with good EMI-SE properties.     

Surface treatment of titanium dioxide nanopowder using rotary electrode dielectric barrier discharge reactor

Titanium dioxide (TiO2) nanopowder (P-25;Degussa AG) was treated using dielectric barrier discharge (DBD) in a rotary electrode DBD (RE-DBD) reactor.Its electrical and optical characteristics were investigated during RE-DBD generation.The treated TiO2 nanopowder properties and structures were analyzed using x-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR).After RE-DBD treatment,XRD measurements indicated that the anatase peak theta positions shifted from 25.3° to 25.1°,which can be attributed to the substitution of new functional groups in the TiO2 lattice.The FTIR results show that hydroxyl groups (OH) at 3400 cm-1 increased considerably.The mechanism used to modify the TiO2 nanopowder surface by air DBD treatment was confirmed from optical emission spectrum measurements.Reactive species,such as OH radical,ozone and atomic oxygen can play key roles in hydroxyl formation on the TiO2 nanopowder surface.