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1.
利用鞍点复转动及全实加关联的方法,计算了LiⅠ等电子序列[(1s2p)3P,4d]2P0及[(1s2s)1S,5p]2P0自电离态的能量和宽度.计算结果中包括相对论修正和质量极化修正.文中讨论了自电离宽度随核电荷数Z的变化关系,同时也讨论了精细结构分裂值及相对论修正随核电荷数Z的变化关系.  相似文献   

2.
类铍子BeⅠ到OV的自电离态单重P态和单重S态在n=2到n=3能量域的几个最低的能级位置是利用多组态耦合的方法计算了的。并且利用Feshbach投影算符对类铍离子自电离态进行了理论分析。对于能够找到的实验测量、我们的计算与实验一致。  相似文献   

3.
对F原子的光电离截面,人们已经做了大量实验研究,并观察到了大量的自电离共振结构.而与实验相比,理论计算仍存在一定的差异.本文通过对靶态的能量进行修正,利用R矩阵方法计算了F原子基态在3P-1D电离阈值能量范围内的分波光电离截面、总光电离截面以及自电离共振2P4(1D)ns2D,2P4(1D)md2P和2P4(1D)md2D系列的共振位置,并与最新的多组态Hartree-Fock理论计算及实验结果进行了比较,我们的结果与实验符合得更好.  相似文献   

4.
Yb原子里德伯态及价态的场电离阈   总被引:3,自引:1,他引:2       下载免费PDF全文
用偏振激光两步激发得到Yb原子不同|m|值的里德伯态和4f~(13)5d6s6p价态,采用脉冲场电离方法测定了6sns~1S_0(n=21—28),m=0和6snd~1D_2(n=20—27),|m|=0,1各里德伯态及4f~(13)5d6s6p价态的电离阈值。引入stark有效量子数n_s对电离阈值作了计算。对实验和计算结果作了对比分析。讨论了场电离过程中价态与里德伯态之间的相互作用及其对电离阈值的影响。 关键词:  相似文献   

5.
采用三台可调渚激光实施孤立实激发,分三步将处于基态的Ba原子激发到6P1/2nd(J=1,3)和6p3/2nd(J=1,3)自电离态上,获得了分别从6snd1D2(n=7-15)和6sad3D2(n=7-12)激发而得到的6p1/2nd(J=1,3)和6p3/2nd(J=1,3)自电离光谱,重点对主量子数n较低的自电离态进行了实验研究.通过光谱的线形拟合得到了上述能级的位置和宽度等数据,进而获得了量子弓损和约化宽度等信息.通过对不同系列的自电离光谱的分析和比较,详细讨论了这些自电离态的光谱特征及其复杂光谱结构的成因.  相似文献   

6.
利用全相对论性多组态Dirac-Fock方法系统地计算了碱土金属激发态1D-1S电四极光谱跃迁的能级间隔,跃迁几率和振子强度,计算中考虑了重要的核的有限体积效应,Breit修正和QED修正,所得结果和最近的实验数据及理论计算值进行了比较,并探讨了采用电四极矩作为中间共振,获得碱土金属元素的高里德伯态,特别是自电离态的可能性.  相似文献   

7.
曾民勇  何志贤 《物理学报》1995,44(2):196-203
使用组态相互作用理论详细分析He的双重激发自电离态,以及第一电离阈植附近非谐振区e-He~+散射的位相移动,这种位相移动反映了非谐振区内电子——电子短程相互作用.获得了单重态和三重态的S,P,D分波的高精度位相移动,与现有理论计算结果相比,符合得很好. 关键词:  相似文献   

8.
激光诱导自电离及其光电子能谱   总被引:1,自引:0,他引:1       下载免费PDF全文
赵力耕  徐至展 《物理学报》1987,36(4):467-472
在Pano自电离理论基础上,用预解算子方法研究了激光诱导自电离共振及光电子的能量分布,得到了光电子能谱上四个峰值的位置和宽度的严格表达式,推导了某一峰消失时光场参数(光强、频率〕和原子参数(自电离宽度、Fano参量q)之间应满足的关系,详细讨论了光场稳定自电离态的问题。 关键词:  相似文献   

9.
本文采用速度影像技术对Eu原子的自电离弹射电子的动力学过程进行了系统研究.实验采用三步孤立实激发方法分步从基态4f76s6s8S7/2经中间态4f76s6p6P5/2激发到4f76s8s8P7/2Rydberg态上,然后将其进一步共振激发至4f76p1/2(J=3)8s和4f76p1/2(J=4)8s自电离态.根据所用的激发路径及其选择定则可以得出自电离态的总角动量的可能取值;通过自电离过程能量守恒和角动量守恒原理推测自电离衰变对应的离子终态信息.利用电子透镜对上述自电离过程中产生的弹射电子进行聚焦和成像,通过位置敏感探测器对其动能进行分辨,运用速度影像技术进行数学变换和计算得到弹射电子的能量分布,分析并给出Eu原子自电离衰变分支比.同时通过调谐第三步激光的波长,得出了分支比随光子能量的变化规律,探讨了实现Eu离子粒子数反转的可能性.  相似文献   

10.
采用鞍点变分方法和鞍点复数转动方法,并考虑相对论修正、质量极化效应,计算了类锂等电子系列(Z=10~20) 1s2s2 2S态的电离势、Auger跃迁率和辐射跃迁率.同时还计算了QED效应和高阶相对论修正对电离势的贡献.  相似文献   

11.
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.  相似文献   

12.
A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.  相似文献   

13.
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.  相似文献   

14.
The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.  相似文献   

15.
16.
A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.  相似文献   

17.
A transient suppression method for piezoelectric ceramic transducer is presented. By adding some special pedestal pulses to the original transmitted signal, the transient effects in the output of the transducer can be just precisely transmission by use of a narrowband transducer. canceled, thereby achieving the broadband The experimental results show that the transient responses of the sinusoid pulses and coded signals are suppressed successfully and the acoustic waveforms radiated into the surrounding water are improved significantly.  相似文献   

18.
We experimentally demonstrate amplitude squeezed soliton utilizing intensity-dependent self-phase modulation in an asymmetric Sagnac interferometer.The system.whose components are connected via ferrule connector/physical connection(FC/PC)fiber connectors,constitutes all-fiber configuration to generate squeezed soliton.Soliton amplitude reduction measured by homodyne detection is near 4.0 dB below the shot-noise level.Optimal squeezing fields in both simple and compact all-fiber configuration are obtained.  相似文献   

19.
The(2 1)-dimensional nonlinear Schr(o)dinger(NLS)equation with spatially inhomogeneous nonlinearities is investigated,which describes propagation of light in(2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities.New types of optical modes and nonlinear effects in optical media are presented numerically.The results reveal that the regular split of beam can be obtained in (2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities,by adjusting the guiding parameter.Furthermore,the stability of beam regular split is discussed numerically,and the results reveal that the beam regular split is stable to the finite initial perturbations.  相似文献   

20.
In the real-world application of face recognition system, owing to the difficulties of collecting samples or storage space of systems, only one sample image per person is stored in the system, which is so-called one sample per person problem. Moreover, pose and illumination have impact on recognition performance. We propose a novel pose and illumination robust algorithm for face recognition with a single training image per person to solve the above limitations. Experimental results show that the proposed algorithm is an efficient and practical approach for face recognition.  相似文献   

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