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应用不可分辨跃迁阵(UTA)模型结合相对论多组态Dirac-Fock方法,对金激光等离子体0.40~0.62nm范围内的带状谱和线状谱的主要特征参数进行了计算和分析,理论计算值和实验结果较之于单纯用UTA模型计算所得结果符合得更好。研究表明,对于谱线数目较少而又稀疏的跃迁,基于线谱的单独计算对UTA模型进行修正是合理和必要的。 相似文献
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Al原子共振双线跃迁几率实验研究 总被引:3,自引:0,他引:3
我们用Nd:YAG脉冲激光烧蚀金属Al靶产生等离子体,利用时间分辨技术摄取Al等离子体辐射时间分辨谱,获得Al原子共振双线辐射谱;通过积分谱线下的面积,计算共振双线强度;根据共振双线强度比,推断Al原子共振双线跃迁几率比,并与理论计算结果比较。结果发现,实验结果与理论计算符合的很好。 相似文献
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在星光II激光装置上,采用PET平面晶体谱仪与宽20μm的狭缝构成一维空间分辨光谱测量系统,对金平面靶激光等离子体进行观测,获得了沿靶面法向一维空间分辨的金M带发射谱。在实验谱中观察到了Au元素类Ni离子的电四极跃迁线3p63d10(1S0) 3p53d104d(3/2,5/2)J=1。利用电四极跃迁线对电子密度的敏感特性,开展了金激光等离子体电子密度诊断的尝试,确定出利用该谱线进行电子密度诊断的有效范围大致在1019~4.5×1021cm-3之间。 相似文献
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利用Nd∶YAG激光作用于真空腔内的高纯固体钼(Mo)靶产生等离子体,并测量了不同脉冲激光功率密度下Mo等离子体在2~9 nm范围内的时间积分光谱。基于碰撞辐射平衡模型(CRM)和Cowan程序计算得到不可分辨跃迁峰(UTA)原子光谱数据,并假设谱线展宽为高斯线形,获得了在不同电子温度和电子密度下的理论模拟光谱,模拟光谱与实验光谱吻合的较好。实验与理论研究光谱表明:Mo ⅩⅥ-Mo ⅩⅫ离子的3d-4f不可分辨跃迁峰位于水窗波段,通过控制脉冲激光参数和采用合适的等离子体约束条件,获得水窗辐射波段Mo离子的高丰度布居,有望将激光Mo等离子用于单脉冲活体细胞显微成像水窗光源。 相似文献
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在“星光-Ⅱ”钕玻璃激光装置上,聚焦三倍频激光束于真空室内Au微点靶表面,形成高剥离 态热等离子体光源.用Pentaerythritol(PET)(2d=0.8742nm)平晶谱仪,摄录了Au离子在0.3 —0.4nm范围内的X射线发射谱.基于相对论性多组态Dirac-Fock程序包,建立了相对论性次 组态平均能计算程序,结合自旋-轨道劈裂跃迁系(SOSA)理论,计算了Au离子类Cu至类Ge离 子细致带结构谱孤立峰的中心波长和半高全宽.26条3d—nf(n=5,6,7)类Ni至类As离子子组态 跃迁形成的
关键词:
金
精细结构
自旋-轨道劈裂跃迁系
不可分辨跃迁系
X射线 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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使用细致组态/不可分辨跃迁系模型计算了不同的温度、密度下金等离子体的辐射平均自由程,注意到了一个普遍存在的理论现象--低温区鼓包现象,并从光子的分频自由程和权重函数两个方面探讨了该现象形成的物理机制. 相似文献
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使用细致组态/不可分辨跃迁系模型计算了不同的温度、密度下金等离子体的辐射平均自由程,注意到了一个普遍存在的理论现象——低温区鼓包现象,并从光子的分频自由程和权重函数两个方面探讨了该现象形成的物理机制. 相似文献
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在“星光Ⅱ”装置上,采用新型双盘靶研究X射线谱在次级得到改造的特性,并测量出初、次级等离子体碰撞的速度.这种双盘靶一定程度上避免了初级等离子体喷射的影响,可以提高烧蚀次级X射线的干净性.采用两台软X射线谱仪分别对初级和次级辐射的X射线进行测量,采用X射线条纹相机测量双盘靶等离子体喷射的时空扫描图象,并对实验结果进行简单的物理分析
关键词:
双盘靶
X射线再辐射
等离子体碰撞 相似文献
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V. S. Belyaev V. I. Vinogradov A. S. Kurilov A. I. Magunov A. P. Matafonov T. A. Pikuz I. Yu. Skobelev A. Ya. Faenov 《Journal of Experimental and Theoretical Physics》2003,96(5):897-903
X-ray emission spectra of the plasma created at the surface of magnesium, aluminum, copper, and zinc targets heated by 1-ps laser pulses with a peak power density of up to 1016 W/cm2 were measured. The effect of a picosecond prepulse on the spectra was studied for various power densities and intensity contrasts of the main laser pulse. It is established that the emission spectra of laser plasmas are weakly affected by a change from 105 to 107 in the main pulse contrast relative to the first prepulse. Variations in the parameters of emission from aluminum and magnesium plasmas were calculated using relative intensities and widths of the resonance lines of H-and He-like ions and their two-electron satellite peaks. 相似文献
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为了准确诊断激光等离子体的电子密度,提出了一种基于极化光谱的类氦共振线与互组合线相对强度比诊断电子密度的方法.该法考虑了激光等离子体发射的X射线存在极化的特性,用极化光谱理论对测量的类氦共振线和互组合线光谱相对强度比进行精密校正,再推导等离子体的电子密度.在2×10 J激光装置上进行了实验,使用极化PET(002)晶体谱仪测量了Al类氦离子光谱,利用光谱的极化特性推出Al等离子体的电子密度约为1.5×1020 cm-3.结果表明极化X光谱推导等离子体电子密度方法适合激光高温高密等离子体诊断. 相似文献
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激光等离子体软X射线辐射能谱时间分辨测量研究 总被引:1,自引:1,他引:0
利用(国内最近研制成功的)带聚酰亚胺膜底衬的金透射光栅与软X射线条纹相机相配合,(在LF11~#激光装置上)使用波长为0.53μm的激光打靶,测量了平面Au靶软X射线时间分辨能谱。测量结果观察到了金等离子体的O带辐射强度随时间增加的现象。文章计算了光栅的衍射效率,并讨论了影响测量谱的几个关键因素。 相似文献
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A new high spectral resolution crystal spectrometer is designed to measure very low emissive X-ray spectra of laser-produced plasma in 0.5-0.9 nm range. A large open aperture (30 ×20 (mm)) mica (002) spherically bent crystal with curvature radius R = 380 mm is used as dispersive and focusing element. The imaging plate is employed to obtain high spectral resolution with effective area of 30 × 80 (mm). The long designed path of the X-ray spectrometer beam is 980 mm from the source to the detector via the crystal. Experiment is carried out at a 20-J laser facility. X-ray spectra in an absolute intensity scale is obtained from Al laserproduced plasmas created by laser energy of 6.78 J. Samples of spectra obtained with spectral resolution of up to E/△E - 1500 are presented. The results clearly show that the device is good to diagnose laser high-density plasmas. 相似文献
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R.W. Lee B.L. Whitten R.E. Stout 《Journal of Quantitative Spectroscopy & Radiative Transfer》1984,32(1):91-101
X-ray spectroscopy is a powerful tool for understanding the kinetics of highly ionized plasmas. Its usefulness depends on the accuracy of the model used in analyzing spectra. We have developed a computer code for modeling and analyzing plasmas which is highly accurate as well as fast and easy to use. It produces synthetic spectra for hydrogen-like and helium-like ions at arbitrary density and temperature. Populations are calculated from rate equations including all relevant collisional and radiative process. The level populations of the hydrogen, helium and lithium-like ionization stages are calculated explicitly; those of all other ionization stages are lumped into one level. The microfield distribution and the shape of the line profiles are determined using detailed calculations. The code includes graphics to plot line ratios and synthetic spectra, and to do on-line analysis of experiments. The usefulness of this technique is demonstrated by analyzing the spectra from three different experiments: a laser irradiated aluminum disk; a neon gas puff pinch; and a laser imploded gas microballon. 相似文献
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Temporally resolved emission spectra (360-630 nm) of carbon ablation plasmas produced during laser hole boring by a 25-ns duration 1-J ruby laser pulse are presented. The emitted line radiation originates from, C+++ to C+ depending upon the time relative to the laser pulse. Plasma temperatures of 12-14 eV during the laser pulse to about 4 eV, 140 ns after the laser pulse are obtained by comparing the spectroscopic results to a collisional-radiative equilibrium (CRE) model which bridges the gap between the local thermodynamic equilibrium (LTE) model and the coronal model. 相似文献
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The results are presented on the observation of X-ray spectra of plasmas formed by 250-psec laser pulses focusing on Ti, Fe and Cr targets. Specific characteristics of the spectra obtained are explained on the basis of a transient heating model. 相似文献