共查询到18条相似文献,搜索用时 140 毫秒
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在惯性约束聚变(ICF)实验中,点火靶丸表面(界面)的粗糙度和缺陷所产生的流体力学不稳定性是决定点火成功与否的关键因素之一,设计和研制流体力学不稳定性分解实验用靶是解决该问题的主要技术手段。结合国内外的研究现状和神光-Ⅱ激光装置的特点,设计并研制了一种新型柱状激波管。该靶型由三种介质组成,分别为调制聚苯乙烯(CH)圆片、柱状碳气凝胶(CRF)和CH微套管。调制CH圆片和柱状CRF通过微加工技术装配到CH微套管内,封装后形成柱状激波管。介绍了该靶型的设计原理和详细的制备工艺,并对相应的靶参数进行了测量。结果表明:柱状CRF气凝胶具有较好的成型性,长度、直径和密度分别为1000μm、730μm和250mg·cm-3;CH圆片的厚度和直径分别为15μm和730μm,表面调制图形的周期和峰谷差分别为100μm和4.3μm;实验得到的柱状激波管的轴向和径向最大装配误差分别为2μm和3μm。 相似文献
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惯性约束聚变(ICF)中的瑞利-泰勒不稳定性(RTI)研究需要基于多种结构的调制靶,针对目前调制靶制备的工艺问题,采用双光子3D打印工艺制备了平面调制、平面复合调制及球壳型调制三种典型结构的调制靶,靶材料为光敏树脂(95%:C23H38N2O8,5%:C4H6O2)。采用激光共聚焦显微成像分析了三种调制靶的实际结构参数,三种靶型的实测形貌及其参数与设计结构及参数具有良好匹配度。为进一步验证双光子3D打印新型工艺制备调制靶的可行性,实验团队在“神光Ⅱ”高功率激光实验装置上进行了纳秒激光打靶实验,结果显示靶表面的调制在激光直接驱动下受RTI的作用随时间呈增长趋势,初始峰谷值为4μm的调制在激光驱动2.5 ns后形成了长度达100μm的高密度射流,表明基于高精度3D打印工艺制备结构复杂的调制靶用于RTI研究具有较高可行性。 相似文献
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用于ICF实验的掺溴聚苯乙烯平面调制箔靶 总被引:1,自引:0,他引:1
以掺溴聚苯乙烯平面调制箔靶的制备为主,介绍通过激光干涉法结合图形转移工艺获得具有正弦起伏图形的掺溴聚苯乙烯平面调制箔靶的工艺.对表面调制起伏图形的精确转移进行研究,以SEM和台阶仪监控图形转移过程,控制耦合在调制图形上的表面粗糙度. 相似文献
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针对如何实现微小尺度(μm~mm)靶零件装配过程中的在线检测,研制了应用于微靶装配的显微视觉检测系统,并对系统的构成与显微成像、图像预处理、特征检测等关键图像处理技术进行了详细论述。提出了针对微靶零件的新型多重滤波除噪算法和几何特征检测算法,并以铝台阶、柱腔等微靶零件为应用实例开展了实验研究。结果表明,该系统采用的算法能有效、快速、准确地对靶零件进行几何特征和实时位置检测,在检测视场为3mm时,其检测精度≤3μm,角度检测精度≤0.1°,适用于ICF微靶等微型器件的微装配。 相似文献
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Spectral enhancement of thermal radiation by laser fabricating grating structure on nickel surface 下载免费PDF全文
《中国物理 B》2015,(5)
Previous studies have shown some correlations between the optical properties of objects and their surface patterns. We fabricate tens of micrometer period gratings by femtosecond laser direct writing technology on polished nickel targets and measure their thermal radiation spectra at a temperature of 623 K by Fourier transform infrared(FTIR) spectrometry. The results show an obvious major enhanced peak in which the wavelength is slightly larger than the grating period. Surface plasmon resonance(SPR) and Kirchhoff's law of thermal radiation are applied to give this phenomenon a preliminary explanation. In addition, we utilized rigorous coupled wave analysis(RCWA) to simulate the absorption spectrum of the grating surface. The experiment results show good agreement with the simulation results. 相似文献
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The optical properties of gold layer deposited on antireflection subwavelength-structured surface are first exposed. The experimental results of the reflectances and transmittances for several different thicknesses of gold-deposited layers on the subwavelength structures are carried out. The nanostructured surface with spatial period and a diameter of about 230 nm and height of about 150 nm on polyethylene terphthalate (PET) film is fabricated by micro-replication process of UV imprinting. Comparing these with the bare gold-deposited layer and bare nanostructure, the results show that the optical films with the suitable gold layer deposited on antireflection subwavelength-structured surface has high transmittance and low glare in the visible spectral range and high reflectance in the infrared range. That is to say, when the antireflection subwavelength-structured surface is coated with a gold layer of several tens of nm thickness, it will have some unique optical characters. 相似文献
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N. N. Gorobei A. S. Luk’yanenko A. E. Chmel 《Journal of Experimental and Theoretical Physics》2005,101(3):468-471
A time-ordered sequence of topographic images of a stressed amorphous Fe70Cr15B15 ribbon is presented. It is shown that the surface of this material (unlike polycrystalline metal foil) has a fractal structure due to the nonequilibrium conditions of its formation. As a tensile stress of about 500 MPa is applied to the surface, the fractal dimension of the surface increases from 1.21±0.02 to 1.34±0.03, then drops to 1.12±0.03, and finally increases to 1.22±0.02. In about 1.5 hours, a complex surface morphology characterized by a roughness amplitude of several tens of nanometers evolves into a regular pattern of shear bands with amplitude of about 300 nm. Self-affine changes in surface morphology are explained by competition between several processes, including crack propagation, surface smoothing, and self-diffusion. 相似文献
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In recent years, polymer nanoparticles have been investigated with great interest due to their potential applications in the fields of electronics, photonics, and biotechnology. Here, we report the spontaneous formation of polymer nanoparticles from a clear solution containing a nonvolatile poor solvent by slow evaporation of a volatile good solvent. During evaporation of the good solvent, the solution gradually turns turbid. After evaporation, polymer nanoparticles of homogeneous shape and size are dispersed in the poor solvent. Homogeneous nucleation and successive growth of polymer particles takes place during the dynamic nonequilibrium process of solvent evaporation. The size of the particles, ranging from tens of nanometers to micrometer scale, depends on both polymer concentration and the solvent mixing ratio. Because of the physical generality of the particle formation mechanism, this procedure is applicable to a wide variety of polymers with suitable combinations of solvents. Here, we also show unique features, surface structures and surface properties of polymer nanoparticles prepared by this method. 相似文献
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Xiaochang Ni K. K. Anoop X. Wang D. Paparo S. Amoruso R. Bruzzese 《Applied Physics A: Materials Science & Processing》2014,117(1):111-115
We investigated the ion laser-produced plasma plume generated during ultrafast laser ablation of copper and silicon targets in high vacuum. The ablation plasma was induced by ≈50 fs, 800 nm Ti:Sa laser pulses irradiating the target surface at an angle of 45°. An ion probe was used to investigate the time-of-flight profiles of the emitted ions in a laser fluence range from the ablation threshold up to ≈10 J/cm2. The angular distribution of the ion flux and average velocity of the produced ions were studied by moving the ion probe on a circle around the ablation spot. The angular distribution of the ion flux is well described by an adiabatic and isentropic model of expansion of a plume produced by laser ablation of solid targets. The angular distribution of the ion flux narrows as the laser pulse fluence increases. Moreover, the ion average velocity reaches values of several tens of km/s, evidencing the presence of ions with kinetic energy of several hundred eV. Finally, the ion flux energy is confined in a narrow angular region around the target normal. 相似文献
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《Solid State Communications》2002,121(9-10):513-517
Reflectance properties of ZnSe epilayers grown on GaAs substrates are studied at 80 K. Oscillation features are observed in the region of exciton resonance which are significantly different depending on the epilayer thickness L. For optically thin layers with thickness in the range of several tens of nanometer, reflectance oscillations appear above the light-hole (lh) exciton, while for optically thick layers with thickness in the range of a micrometer, reflectance oscillations appear between 1s and 2s excitons. These oscillations are interpreted as the quantized levels of the exciton center-of-mass motion in the lower branch of the polariton for optically thin layers and Fabry–Perot modes in the upper branch of the polariton for optically thick layers, respectively. The reflectance data are analyzed in the frame work of a dielectric function with a polariton dispersion. 相似文献
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B. Hou J. Nees A. Mordovanakis M. Wilcox G. Mourou L.M. Chen J.-C. Kieffer C.C. Chamberlain A. Krol 《Applied physics. B, Lasers and optics》2006,83(1):81-85
Interaction of relativistic intensity laser pulses encompassed at focus by a volume of a few wavelengths cubed with solids
is examined. Spectroscopy of hard X-rays of several metallic targets, including Cu, Ge, Mo, Ag, and Sn, irradiated in this
regime at a high repetition rate (0.4 kHz), has been experimentally studied. The Kα and Kβ peaks of all targets were obtained. Averaged electron temperatures of several tens of keV and total X-ray conversion efficiencies
up to 0.02% are calculated. The X-ray source size is measured to be ∼10 micron with varying elliptical shape.
PACS 52.38.Ph; 52.59.Px; 52.70.La 相似文献