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钴、镍和铜离子的类钠件线谱 总被引:2,自引:1,他引:1
以激光辐照固体平面靶产生的高温等离子体作为辐射源,利用平晶x射线谱仪观测了钴、镍和铜的类氖离子2p-3d跃迁的长波类钠伴线x射线光谱。根据等电子数序规律外推,与观测波长值比较,给出了对这些伴线进行辨认的结果。 相似文献
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在电子碰撞激发类Ne锗X光激光实验的基础上,对线状等离子体空间分布特性进行定量测量和分析。首次给出了线状等离子体分布尺度,同时也研究了不同的激光参数和靶结构对等离子体状态的影响。 相似文献
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对磁场约束下激光诱导铜等离子体光谱强度演化进行了实验研究,分析了在磁场约束环境下的等离子体光谱强度演化过程以及激光能量对光谱增强的影响.实验结果表明:在磁场约束下铜等离子体内原子光谱和离子光谱均有所增强,在磁场约束下Cu I 510.55 nm谱线强度时间演化过程中在1.2—5.7μs时间范围内附近出现双峰结构,在距离靶材表面0—1.4 mm空间范围内磁场约束Cu I 510.55 nm光谱增强明显.Cu I510.55 nm和Cu I 515.32 nm光谱增强因子随激光能量的增加呈单调递减变化,激光能量20 mJ时增强因子最大分别为11和8.对磁场约束下等离子体发射光谱强度增强的物理原因进行了探讨. 相似文献
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激光大气等离子体光谱特性实验研究 总被引:19,自引:5,他引:14
报道了对波长为1.06μm的脉冲激光在气体样品中产生的等离子体进行光谱研究的结果。气体样品为一个标准大气压的纯氮、纯氧和空气,光谱探测范围为300~900nm。结果表明,各种气体样品的激光等离子体光谱均表现为连续谱和线状谱的叠加,文中分别给出了连续谱和线状谱的基本特征,讨论了这些特征与等离子体物理特性的关系,并分析了纯氮、纯氧与空气激光等离子体光谱之间的异同。给出了激光等离子体光谱的时间演化和空间分布的基本特征,并初步讨论了与这些特征相关的等离子体物理特性。这些结果有助于加深对激光等离子体特性和机理,特别是对等离子体产生后的弛豫过程和复合机制的了解。 相似文献
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本文研究了类锂硅离子和类钠铜离子两种复合X射线激光的增益空间分布,结果表明复合X射线激光的增益出现在离靶面一定距离的中等等离子体电子密度区,而近靶面高密度区存在自吸收现象. 相似文献
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冯贤平 《核聚变与等离子体物理》1988,(2)
本文在临界密度区域内激光场趋于零的假设下,系统地研究了由强激光辐照非均匀等离子体引起临界密度变陡的现象,给出了较为精确、完备的描述等离子体密度结构的各种参数和等离子体密度的坪台结构。 相似文献
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为了研究激光推进技术中激光与材料相互作用的机制,获取等离子体状态参数及力学参数,采用Nd:YAG被动调Q固体激光器烧蚀硬铝,通过激光诱导等离子体光谱技术测得等离子体光谱和温度,由冲量摆测得力学参数。实验结果显示:在激光功率密度0.534×108 W/cm2时,靶材表面的等离子体温度在等离子体辐射过程中呈二次曲线衰减;改变靶材等离子体点燃阈值附近的激光功率密度时,随着功率密度的增加,等离子体温度、冲量耦合系数也随着增大,当功率密度达到靶材的等离子体点燃阈值时,各参数达到最大,此后随着功率密度增加,由于等离子体对能量的屏蔽作用,导致靶材表面的等离子体温度降低,等离子体获得的动能减少,靶材耦合的冲量降低。 相似文献
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J. Zhang K. Sugioka K. Midorikawa 《Applied Physics A: Materials Science & Processing》1998,67(5):545-549
+ :YAG laser (266 nm) is reported. With the assistance of plasma resulting from laser irradiation on a metal target, the fused-quartz
substrate is easily etched by the 266-nm laser beam in spite of the fact that the substrate is transparent to this wavelength.
In contrast, no ablation takes place without the metal target, but damage is generated on the substrate surface. The ablated
region is observed by optical microscopy and scanning probe microscopy (SPM), which reveal a fine grating structure (line
spacing of 20 μm) without any severe damage. A series of experiments on the dependence of the ablation rate and the threshold
laser fluence on ablation parameters, such as laser fluence, the number of pulses, and the distance between the fused quartz
and the metal target is performed. On the basis of the results, three possible mechanisms of direct plasma interaction, plasma
heating, and metal film deposition are discussed.
Received: 27 February 1998/Accepted: 5 June 1998 相似文献
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基于细致组态(DCA)方法和跃迁系列群 (UTA) 模型,采用全相对论处理并结合量子亏损理论,计算了金Au激光等离子体的M带5f-3d跃迁的透射谱, 给出了金等离子体在不同电子温度和电子密度的时空电离态特性,平均电离度,离子丰度和离子内各能级的布居数,并模拟出Au等离子体的M 带5f-3d跃迁的细致谱线,其计算结果可对激光等离子体透射谱的电子温度和电子密度进行精密诊断. 相似文献
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Misra A. Thareja R.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(6):1553-1558
Fast photography is used to investigate the expansion dynamics of the laser ablated plasmas in various ambient atmospheres and laser energies. Dependence of plasma parameters such as velocity, temperature, density, and pressure on time and ambient atmosphere is presented. The measured vapor pressure and temperature decrease with the increase in ambient gas pressure. The images of the expanding plumes are used to locate the shocked region and hence to estimate the plasma parameters in the shocked regime. The calculated plasma parameters are used to optimize target-substrate distance, a key parameter for laser ablation deposition of thin films 相似文献
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Laser-induced breakdown spectroscopy (LIBS) was applied for parametric studies of titanium (Ti) plasma using single and double
pulsed laser excitation scheme. Here a pulsed Nd:YAG laser was employed for generation of laser produced plasma from solid
Ti target at ambient pressure. Several ionized titanium lines were recorded in the 312–334 nm UV region. The temporal evolution
of plasma parameters such as excitation temperature and electron number density was evaluated. The effect of incident laser
irradiance, position of the laser beam focal point with respect to the surface of illumination, single and double laser pulse
effect on plasma parameters were also investigated. This study contributes to a better understanding of the LIBS plasma dynamics
of the double laser pulse effect on the temporal evolution of various Ti emission lines, the detection sensitivity and the
optimal dynamics of plasma for ionized states of Ti. The results demonstrate a faster decay of the continuum and spectral
lines and a shorter plasma life time for the double pulse excitation scheme as compared with single laser pulse excitation.
For double pulse excitation technique, the emissions of Ti lines intensities are enhanced by a factor of five which could
help in the improvement of analytical performance of LIBS technique. In addition, this study proved that to avoid inhomogeneous
effects in the laser produced plasma under high laser intensities, short delay times between the incident laser pulse and
ICCD gate are required. 相似文献
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The generation of relativistic electromagnetic solitons in plasma with spatiotemporal density modulation is investigated.
When two counter-propagating laser pulses overlap in underdense plasma, the interaction between the pulses and plasma modulates
the electron and ion densities resulting in localized, stable, long-living relativistic electromagnetic solitons. They are
caused by the Stimulated Raman Scattering instability. The dependence of the formation of relativistic electromagnetic solitons
on the ion motion, plasma parameters, and laser parameters is studied by particle-in-cell simulations as well. 相似文献