共查询到20条相似文献,搜索用时 15 毫秒
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采用Skupshy-Lee(S-L)球谐模分解方法,按一个简化的物理模型,对激光直接驱动聚变中不同束-靶条件下的靶面初始辐照不均匀度的均方根偏差进行了数值计算,由此分析了在光束完全对称排布的多光束辐照系统中,光束截面光强分布,聚焦透镜F数,离焦参数(靶心室焦距离与靶丸半径之比),光束数这几个主要因素对辐照的均匀性的影响。 相似文献
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Journal of Russian Laser Research - Irradiation of a thermonuclear capsule by a laser-induced X-ray pulse (indirect drive) is a way to maximally reduce the inhomogeneity of the capsule heating and,... 相似文献
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Noriaki Nishi Takahisa Jitsuno Koji Tsubakimoto Shinichi Matsuoka Noriaki Miyanaga Masahiro Nakatsuka 《Optical Review》2000,7(3):216-220
A two-dimensional multi-lens array 350 mm in diameter with spherical element lenses has been tested to improve the irradiation uniformity of a high power glass laser for inertial confinement fusion (ICF). A circular shape for the element lens aperture is chosen to eliminate azimuthally asymmetric intensity distribution. An approximate flat-top intensity distribution is obtained with a lens array of 37 lenses. Beam patterns of a coherent laser and partially coherent light (PCL) with the random phase plate (RPP) and the multi-lens array (MLA) are measured in a GEKKO XII glass laser system. Spherical mode structure of the irradiation nonuniformity of 5.6% with MLA is estimated with cos3 θ distribution of absorption coefficient in the target plasma. 相似文献
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We have investigated the spectral characteristics of scattered radiation ( = 0.69 m and = 1.06 m) under probing laser action (q = 103 W/cm2) on a textolite target of streamline shape blown by a cold two-phase stream (with talc and black particles). By the measured transverse scattering indicatrices the dependences of the scattered radiation intensity on the probing angles and the sort of particles and their number density in the stream have been established. The relative contributions of particles of the stream and the target surface to the total scattering by the target–two-phase-stream system have been determined. 相似文献
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Bel’kov S. A. Bondarenko S. V. Garanin S. G. Gus’kov S. Yu. Demchenko N. N. Zmitrenko N. V. Kuchugov P. A. Stepanov R. V. Shcherbakov V. A. Yakhin R. A. 《Journal of Experimental and Theoretical Physics》2020,131(4):636-644
Journal of Experimental and Theoretical Physics - The compression and burning of a fusion target ignited by a focused shock wave produced at the action of a time-profiled second harmonic laser... 相似文献
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A simple scheme based on the uniform distribution for the placement of numerous laser beams in the context o~ fiber-based laser fusion is proposed. It is theoretically demonstrated that all modes of the geometrical factor can be eliminated if sufflcient laser beams are uniformly distributed on the sphere. In the case of a finite number of laser beams, a quasi-uniform distribution of beams can be achieved based on the equal area subdivision algorithm. Numerical simulations indicate that with the increasing number of laser beams, the order of the dominant geometrical mode increases, and the irradiation nonuniformity decreases accordingly. 相似文献
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Glazyrin S. I. Lykov V. A. Karpov S. A. Karlykhanov N. G. Gryaznykh D. A. Bychenkov V. Yu. 《JETP Letters》2022,116(2):83-89
JETP Letters - High gradients of electron temperature appear in plasma corona under direct laser irradiation of inertial confinement fusion targets. This results in nonlocality of heat transport.... 相似文献
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V. S. Burakov A. F. Bokhonov M. I. Nedel'ko N. A. Savastenko N. V. Tarasenko 《Journal of Applied Spectroscopy》2002,69(6):907-912
The laser plasma produced by irradiation of a graphite target simultaneously by the first and second harmonics of two Nd3+:YAG lasers has been studied by emission spectroscopy methods. The delay between radiation pulses () varied from 0 to 700 sec. It is established that in the absence of a delay between pulses ( = 0) the increase in the intensity of plasma emission at the wavelengths corresponding to the radiative transitions of the C2 and C3 molecules is of nonradiative character. The plasma produced by laser radiation at the wavelength = 1064 nm exerts its influence on the radiation spectrum of the plasma produced by laser radiation at the wavelength = 532 nm, if the magnitude of the delay between laser pulses does not exceed 30 sec. The most probable reason for this character of influence of the prepulse on the laser plasma radiation spectrum is sublimation of soot particles caused by laser radiation at = 532 nm. 相似文献
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The excitation of eigen surface waves by tubular electron beams in cylindrical discharge devices is studied. The influence of the wave‐field azimuthal structure on the excitation efficiency and nonlinear stage of the plasmabeam instability is investigated both numerically and analytically. Analytical expressions for the saturation amplitude and excitation efficiency of the wave under study are derived. They are found to agree well with results obtained by numerical modelling of the plasma‐beam interaction presented in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Samokhin A. A. Shashkov E. V. Vorobiev N. S. Zubko A. E. 《Physics of Wave Phenomena》2019,27(4):268-270
Physics of Wave Phenomena - A possibility of calibrating a piezo transducer by comparing thermoacoustic and vaporization pressure signals generated in a metal (liquid mercury) irradiated with... 相似文献
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以钢/铝双硬度爆炸焊接复合靶为研究对象,采用系列弹道实验和数值模拟方法,研究了其在球形弹丸垂直侵彻作用下的抗侵彻性能。侵彻实验利用直径为14.5mm的滑膛枪发射直径为6mm的钢质球形弹丸;采用LS-DYNA3D非线性有限元程序和有限元-光滑粒子流体动力学(FE-SPH)耦合法,进行数值模拟。基于实验和数值模拟结果,分析了不同靶板的毁伤机理和破坏模式,以及靶板厚度、强度等因素对复合靶抗侵彻性能的影响。结果表明:在球形弹丸的垂直侵彻作用下,钢面板发生剪切冲塞破坏,铝背板发生延性扩孔破坏;对于双层靶而言,钢面板与铝背板的厚度比约为2/3时,复合靶的抗侵彻性能最差;数值计算结果与实验结果吻合良好,表明FE-SPH耦合算法可较好地预测双层复合靶板的抗侵彻性能。 相似文献
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随机分布粒子侧向散射光特性的实验研究 总被引:4,自引:2,他引:2
两种不同直径(0.22μm和0.494μm)的粒子与过滤的蒸馏水制作不同体积分数的悬浮液作为散射介质。比较了微粒子群侧向散射光中垂直与水平两种偏振光的强度分布。实验结果表明,直径大的粒子其侧向散射光中水平方向线偏振强度远远小于直径小的粒子,而垂直方向线偏振强度却完全相反,远远大于直径小的粒子。 相似文献
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An experimental investigation was conducted to explore the characteristics of microscopic boiling induced by firing a microsecond pulsed laser beam on a thin platinum (Pt) film that immerged in the liquid nitrogen (LN2) cryostat. High-speed photography aided by a high-voltage lighting system was employed to visually observe the bubble formation and the dynamical boiling process of LN2. A rapid transient temperature-measuring system was designed to record the temperature evolution of the heating surface. Explosive boiling, characterized by bubble cluster, was observed within LN2 at the early stage of laser heating, and conventional boiling followed after a certain time. The transition time, therefore, was introduced for separating these two different boiling modes. The temperature of Pt film rose sharply to its maximum during laser pulse, with a very high rising rate of about 107 K/s, and then dropped rapidly after laser irradiation. A model of bubble cluster was proposed to describe the explosive boiling heat transfer, and the latent heat released by bubble collapse in explosive boiling was explored as an important mechanism considerably influencing the boiling heat transfer. 相似文献
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激光照射人血液荧光光谱变化的研究 总被引:2,自引:1,他引:2
采用OMA Ⅲ微弱信号检测系统研究了人血液荧光光谱在激光照射下的变化情况。结果表明 :在6 32 8nmHe Ne激光诱导下 ,不同血液在 6 70 ,730 ,981nm附近出现三个荧光峰 ;荧光强度在一定范围内与照射激光功率呈线性变化关系 ;随着激光照射时间的增加 ,三个峰位上的荧光强度下降 ,8min后趋于隐定值 ;在激光照射过程中 ,三个峰位出现不同数值的移动。 相似文献