A novel simulation method to evaluate the collection performance of a monolithic active pixel sensor

A novel simulation method is presented in this paper to evaluate the collection performance of monolithic active pixel sensor (MAPS) devices for minimum ionizing particle tracking. A simplified 3D matrix pixel structure is built using the computer aided design software Sentaurus. The virtual device is then divided into hundreds of parts and an independent customized X photon model is involved in each part to simulate the conditions under ⁵⁵Fe radiation. After data processing and analysis, charge collection efficiency, collection time and diffusion conditions can be estimated in detail. In order to verify the reliability of the method, comparisons are made between the simulations and experiments. Although there are some defects, it can be concluded that the proposed idea is a feasible method for the evaluation of the MAPS collection performance.     

激光红外主被动复合导引系统

提出了采用激光主动三维成像技术配合被动红外成像技术共同工作的复合导引体制,用于提升地对地导弹的作战效能及对于隐身目标的识别能力。给出了各分系统的设计方案,并提出了合理的导引策略。该套系统能够兼顾红外大视场搜索及激光小视场三维成像,丰富的目标图像信息更加有利于对作战目标进行准确识别。整套复合光学导引系统结构简单、加工难度适中,在将整套导引系统口径控制在100 mm左右的情况下,同样能够实现4 km以上距离的导引。该项技术的提出对于我国复合导引技术的发展及我军导弹作战能力的提升有着重要意义。     

Strategy of manufacturing components with designed internal structure by selective laser melting of metallic powder

Application of selective laser melting for manufacturing three-dimensional objects represents one of the promising directions to solve challenging industrial problems. This approach permits to extend dramatically the freedom of design and manufacture by allowing, for example, to create an object with desired shape and internal structure in a single fabrication step. The design of the part can be tailored to meet specific functions and properties (e.g. physical, mechanical, chemical, biological, etc.) using different materials. Metallic objects were manufactured by Phenix PM 100 machine from Inconel 625 powder. The objective was to analyze the influence of the manufacturing strategy on the internal structure and mechanical properties of the components manufactured by selective laser melting technology. Anisotropy of the internal structure and mechanical properties of the fabricated objects were studied.     

Titanium and aluminum nitride synthesis via layer by layer LA-CVD

The possibility of the layer-by-layer synthesis of 3D parts from nitrides of titanium or aluminum by selective laser sintering/melting is discussed. The relationship between laser processing parameters and structure and phase content of sintered/melted samples are studied by means of optical metallography, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Optimal parameters of SLM process for AlN and TiN synthesis are determined. Solid 3D parts containing a TiN phase are produced from Ti powder. Distortion of the crystalline lattice of AlN and TiN phases is observed with the laser energy input.     

Status of PRESS-MAG-O: The experimental apparatus to probe materials and phenomena under extreme conditions at Frascati

In this contribution we up-to-date the status of the PRESS-MAG-O device, a new instrument under commissioning at the INFN designed to perform magnetic and spectroscopic experiments on samples under extreme conditions. The system has been designed to work at SINBAD, the IR synchrotron radiation beamline operational at DAΦNE. The instrument, that is the result of a significant R&D, will allow performing concurrent high harmonic ac magnetic susceptibility measurements and magneto-optic experiments on a sample under high pressure, with a variable DC magnetic field in a wide temperature range. The vacuum vessel has been designed with four crossing windows to allow optical measurements in the transmission geometry on the sample loaded inside a Diamond Anvil Cell. A new superconducting miniaturized micro-SQUID gradiometer has been also developed to detect the low magnetic signal of the sample and a customized optical system has also been designed to perform IR synchrotron radiation experiments.     

三维射频加速腔程序包MAFIA的开发和应用

介绍了三维射频加速器计算机辅助设计(CAD)程序包MAFIA的特点、功能及其应用。用CAD的方法实现了射频加速器特别是非轴对称带耦合腔的加速器的三维腔形设计。同时介绍了节省内存、节约机时的模型方法,使得在中小型机器上运行大程序(八万条)成为可能。文章主要对L波段的加速腔进行了数值模拟,并和实验进行了比较,结果符合较好;通过三维数值模拟及图形模拟的方法比较了各种形状谐振腔的性能;计算分析了输入耦合腔及高阶模耦合器对加速腔电磁场分布等参量的影响;提出了加耦合器后谐振频率改变的补偿方法。     

基于LabVIEW的超快激光制造系统设计

针对当前大部分超快激光制造系统中存在的三维移动平台控制软件和光学显微镜软件集成化程度低而导致的操作方式繁琐等问题,设计了一种基于LabVIEW软件开发平台的集成化超快激光制造系统控制软件,以实现对超快激光制造系统的高效调控。该系统由飞秒激光器、三维移动平台、在线监测CCD、激光功率计、快门和计算机等六部分构成。设计思路是基于LabVIEW软件平台的多线程编程技术,将飞秒激光束的通断与三维移动平台的移动实现协调控制,采用CCD相机对样品进行对焦和监控加工状态,利用激光功率计对激光功率进行在线监测,并将其集成于同一界面以实现控制。实验证明,与常见超快激光制造系统相比,该系统稳定度高、操作简单、界面简洁、可扩展性强、调节效率高。     

Alumina-zirconium ceramics synthesis by selective laser sintering/melting

In the present paper, porous refractory ceramics synthesized by selective laser sintering/melting from a mixture of zirconium dioxide, aluminum and/or alumina powders are subjected to optical metallography and X-ray analysis to study their microstructure and phase composition depending on the laser processing parameters. It is shown that high-speed laser sintering in air yields ceramics with dense structure and a uniform distribution of the stabilizing phases. The obtained ceramic-matrix composites may be used as thermal and electrical insulators and wear resistant coating in solid oxide fuel cells, crucibles, heating elements, medical tools. The possibility to reinforce refractory ceramics by laser synthesis is shown on the example of tetragonal dioxide of zirconium with hardened micro-inclusion of Al₂O₃. By applying finely dispersed Y₂O₃ powder inclusions, the type of the ceramic structure is significantly changed.     

Femtosecond laser assisted production of dichroitic 3D structures in composite glass containing Ag nanoparticles

Three-dimensional, permanent anisotropic modifications in glass containing spherical Ag nanoparticles are demonstrated using multicolor fs laser irradiation. The method can produce dichroism by deformation of nanoparticles to oblong shapes oriented parallel to the laser polarization. Using samples with a vertical gradient of the fill factor of Ag nanoparticles in the glass substrate and an accordingly inhomogeneous broadening of the surface plasmon band, modifications in various depths can be made using different excitation wavelengths. The induced modifications are reversible: heating to ≈600 °C restores the spherical shape of Ag nanoparticles. This technique could be used in manufacturing of different, 3D, polarization and wavelength selective micro-devices such as polarizers, filters, gratings, display and rewriting optical 3D data storage devices. PACS 78.55.Hx; 78.67.Bf; 78.40.Ha     

拉曼链系统用空间滤波器设计的实验研究

进行了惯性约束聚变（ＩＣＦ）准分子激光拉曼链工程的基础研究工作。为给出拉曼链中所用空间滤波器的设计要求和可靠性,进行了详细的设计实验判断性研究。给出研究过程和结果,并对设计结论和优化方法进行了基础分析。还据实验结果讨论了适用于高功率激光系统的空间滤波器的设计中面临的焦距和滤波小孔孔径选择的不确定性、滤长和光束功率密度对选择小孔的影响等问题。     

Direct manufacturing of Cu-based alloy parts by selective laser melting

The frequent defects of the metal parts, such as non-fully melting, thermal strain, and balling, which are produced by selective laser melting (SLM) that is a novel method of one-step manufacturing, are analyzed theoretically and experimentally. The processing parameters significantly affect the quality of the final parts, and simultaneously, the appropriate laser mode and the special scanning strategy assure a satisfying quality of the final parts. The SLM experiment is carried out using Cu-based powder. The metal part is divided into several scanned regions, each of which is scanned twice at the cross direction with different scanning speeds. The microstructure is analyzed on microscope. The results show that the part is metallurgically bonded entity with a relative density of 95%, and the microstructure is composed of equiaxial crystal and dendritic crystal whose distributions are mainly decided by the scanning strategy.     

频移分离型三维激光多普勒测速仪研究

研究一种采用频移分离方法的新型三维激光多普勒测速仪（３ＤＬＤＶ）。该仪器以单色Ｈｅ－Ｎｅ激光器和单只光电探测器并配合简单的光学发射和接收系统即实现了三维速度分量的同时测量。三个分量的速度信号由声光调制器引入的三种光学频移区分，通过电子滤波器完成信号的相互分离。在光学发射系统设计中采用独特的单轴四光束结构，通过光束组合形成三双光束差动模式的激光多普勒测速仪光。本文中还给出了该仪器的系统设计参数并分析     

Manufacturing geometrically complex nozzle-type parts by means of selective laser melting

The possibility of manufacturing of such geometrically complex parts as nozzles via the selective laser melting of heat-resistant cobalt alloy is demonstrated. The mechanisms responsible for forming the structure of investigated alloys under the conditions of selective laser melting are characterized. The physicomechanical properties of the resulting parts are determined.     

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介绍了用于保护HL-2A装置远红外激光干涉仪探测器的双色滤波器。根据双色滤波器理论优化设计了双色滤波器的外型和结构,并首次用于HL-2A远红外激光干涉仪密度测量系统。实验结果表明,当双色滤波器长度l=0.2mm,直径d=0.23mm,孔之间的间隔s=0.33mm时,双色滤波器能够很好地隔离68GHz的ECRH波带来的干扰,并对890GHz的HCN激光波有较好的透过率。     

双色滤波器在远红外激光干涉仪上的应用

介绍了用于保护HL-2A装置远红外激光干涉仪探测器的双色滤波器。根据双色滤波器理论优化设计了双色滤波器的外型和结构,并首次用于HL-2A远红外激光干涉仪密度测量系统。实验结果表明,当双色滤波器长度l=0.2mm,直径d=0.23mm,孔之间的间隔s=0.33mm时,双色滤波器能够很好地隔离68GHz的ECRH波带来的干扰,并对890GHz的HCN激光波有较好的透过率。     

Effect of precursor preoxidation on the structure of phenolic resin-based activated carbon spheres

Activated carbon spheres with 3D hierarchical porous structure were prepared from phenol-formaldehyde resins with oxidation treatment in air and physical activation in an inert atmosphere. Based on the results of thermogravimetric analysis, infrared spectrometer (IR), scanning electron microscopy (SEM) and nitrogen adsorption/desorption, the effect of preoxidation on the morphology and structure of activated carbon spheres was investigated. The results show that decomposition and crosslinking reactions occur during the preoxidation and the structural changes of precursor generated by the preoxidation lead to differences in the pore structure of activated carbon spheres. The carbon spheres exhibit the unique 3D hierarchical porous structure, high specific surface area of 1897 m²/g and high pore volume of 2.22 cm³/g.     

近红外光上转换发光显示器中干涉过滤膜的设计

介绍了近红外光上转换发光显示器的结构及其原理,为了进一步提高该显示器的亮度等性能并避免近红外光从屏上泄露,根据多层干涉过滤膜设计原理设计了该显示器所需的两个多层干涉过滤膜：一个为在可见光420~800 nm短波段高反射,近红外光800~1000 nm长波段高透射特性的LP膜;另一个为特性与之对应相反的SP膜.采用对称膜的设计并用MATLAB语言进行了仿真优化,得到了总层数为21,厚度分别为1586.8 nm和2157.8 nm的LP膜和SP膜,该膜系在整个波段和较大角度范围内都具有很好的透反特性考虑多层薄膜制备中存在材料折射率和膜层厚度偏差,该设计膜系具有较大的制造容差.     

激光荧光肺癌诊断图象处理系统滤光片的研制

本文论述用于激光荧光肺癌诊断图象处理系统滤光片的膜系设计,制备这套滤光片所采取的工艺措施,最后给出研制的结果。     

Laser printing of conformal and multi-level 3D interconnects

A crucial challenge in three-dimensional multi-chip assemblies is to establish electrical connections between discrete devices. Here, we apply laser printing of congruent voxels of silver nanopaste for the fabrication of conformal and 3D multi-level interconnects. By controlling laser fluence, various 3D electrodes including freestanding tabs and side contacts over vertical walls can be directly printed without the need for sacrificial layers, chemical etching or electroplating. The electrical characteristics of the printed interconnects are similar to those currently in use by the semiconductor industry. These results are a promising step forward in the generation of customized interconnects for 3D microelectronics.