SrI 4dnp和4dnf奇宇称J=1系列自电离态光谱

用激光三步激发方法,以4d^{2 3}P₀价态为中间态,观察了Sr原子4dnp和4dnf奇宇称J=1系列自电离态光谱,在59570—60300cm^-1范围内,测定了60个自电离能级,其中大多数可归属于分别收敛于4d²D_3/2和4d²D_5/2电离限的6个自电离系列,讨论了光谱线的线型和组态相互作用。 关键词：     

Ba原子6pnd(J=1, 3)自电离光谱的实验研究

采用三台可调谐激光实施孤立实激发,分三步将处于基态的Ba原子激发到6p_1/2nd(J=1,3)和6p_3/2nd(J=1,3)自电离态上,获得了分别从6snd¹D₂(n=7—15)和6snd³D₂(n=7—12) 激发而得到的6p_1/2nd(J=1,3)和6p_3/2nd (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,进而获得了量子亏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. 关键词： 孤立实激发 组态相互作用 自电离态     

类钠铜离子的激发自电离

在扭曲波库仑玻恩交换近似下计算了类钠铜离子２ｐ^６３ｓ＋ｅ^-→２ｐ⁵３ｓ３ｌ＋ｅ^-（ｌ＝０，１，２）的内壳层激发截面．结合单组态近似和组态相互作用两种情况下计算的自电离分支比，计算了上述组态的激发自电离截面．结果表明，在入射电子能量为１０９０ｅＶ时，组态相互作用使２ｐ⁵３ｓ３ｄ总的激发自电离截面增大至单组态近似的近两倍；而使２ｐ⁵３ｓ²组态的激发自电离截面减小为单组态近似的３６％；２ｐ⁵３ｓ３ｐ组态的激发自电离截面只是略有下降 关键词：     

AlI原子2D吸收谱的多通道量子数亏损理论分析

本文用多通道量子数亏损理论分析计算了AlI原子的²D吸收谱。采取具有三个不同电离阈的三个分解通道的混合模型。在适当选择了与能量有关的参数μ_α,D_α以及转换矩阵元U_iα之后,计算了第一电离阈和第二电离阈之间的²D自电离谱,并与Roig的测量结果作了比较。利用上述参数延伸到分立能域,得到²D能级的里德伯系列及其振子强度值。其结果与Lin和Weiss的分析以及相关的实验相符。 关键词：     

CH2Br2的同步辐射光电离研究:10—12eV范围内CH2Br2的振动自电离态

报道在超声射流冷却条件下用同步辐射ＶＵＶ光源研究ＣＨ₂Ｂｒ₂的振动自电离结构．根据测量的１０５—１２３ｎｍ范围内母体离子（ＣＨ₂Ｂｒ₂⁺）的光电离产率曲线，获得ＣＨ₂Ｂｒ₂的绝热电离势为１０.２３±０.０１ｅＶ．ＣＨ₂Ｂｒ₂⁺的最低三个电子激发态，即Ａ（²Ａ₂），Ｂ（²Ｂ₁），Ｃ（²Ａ₁）分别位于１０.７８±０.０１ｅＶ，１１.２０±０.０１ｅＶ和１１.２７±０.０１ｅＶ．在１１５.０１—１２１.１５ｎｍ范围内，观察到ＣＨ₂Ｂｒ₂自电离峰叠加在若干台阶结构上，台阶平均宽度为７１６.８±４０.０ｃｍ^-1，对应于ＣＨ₂Ｂｒ₂⁺（Ｘ²Ｂ₂）中Ｂｒ-Ｃ-Ｂｒ反对称的伸缩振动（ｖ₉），所有的峰均归属为收敛于ＣＨ₂Ｂｒ₂⁺（Ｘ²Ｂ₂，ｖ⁺）振动能级的ｎｓ，ｎｐ和ｎｄ自电离Ｒｙｄｂｅｒｇ态．此外，对ＣＨ₂Ｂｒ₂光解离电离产生离子型自由基ＣＨ₂Ｂｒ⁺（Ｘ）的光电离产率曲线的结构也进行了归属 关键词：     

铕原子4f76pns系列自电离态的光谱和动力学过程

通过共振激发技术和速度影像法对铕原子4f⁷6pns（n=7,8）自电离态进行了系统性的研究。首先采用三步共振激发技术探测光谱,通过前两步固定波长的激光将铕原子激发到4f⁷6p²态上后扫描第三步激光的波长,使得三步激光的能量总和位于铕原子4f⁷6pns（n=7,8）自电离态能域附近,从而得到该自电离态的光谱;然后采用速度影像法对其动力学过程进行探测,经过数据分析得到铕原子4f⁷6pns（n=7,8）自电离态的衰变分支比和弹射电子的角分布。不仅从光谱中观察到了强烈的组态相互作用并且确定了部分能态的总角动量,从自电离弹射电子角分布中观察到铕原子4f⁷6pns（n=7,8）自电离态复杂的物理机制,还在该能域内观测到了粒子数反转。最后,本文还对孤立实激发技术在探测低n值自电离态光谱的适用性进行了讨论。     

激光诱导自电离及其光电子能谱

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：     

钪原子的自电离里德伯能级3d4s(1D2)nf2 D3/2,3d4s(1D2)nf2 F5/2和3d4s(1D2)np2 D3/2<

在多通道量子亏损理论框架下,利用相对论多通道理论,分别在冻结实近似和考虑偶极极化下计算钪原子的J^π=(3/2)^-,(5/2)^-的三个收敛于 3d4s(¹D₂)的自电离里德伯系列的能级.对3d4s(¹D₂)np²D_3/2和3d4s(^{1 关键词： 相对论多通道理论 多通道量子亏损理论 电子-电子关联 自电离里德伯系列}     

类钠离子的电子碰撞电离截面

利用相对论修正扭曲波玻恩交换近似,计算了8个类钠离子的电子碰撞直接电离和激发自电离截面.基于这些结果,给出了计算类钠等电子系离子(18≤Z≤39)直接电离和激发自电离截面的高精度拟合公式.计算结果与现有的实验值和其他理论值比较,相当一致 关键词： 电离截面 组态相互作用 扭曲波玻恩交换近似 拟合公式     

F3+和Ne4+离子的光电离截面的理论计算

利用R矩阵方法计算了F³⁺和Ne⁴⁺离子的基态2s²2p²(³P)和激发态2s²2p² (¹D,¹S),2s2p³ (⁵S^o)的分波光电离截面、总光电离截面,分析辨认出了这些离子在自光电离过 关键词： 3+离子和Ne⁴⁺离子')" href="#">F³⁺离子和Ne⁴⁺离子 光电离 自电离共振 R矩阵')" href="#">R矩阵     

Eu原子4f76s(7S)np系列自电离谱的观察和测定

用激光三步共振激发方法观察了Eu原子的自电离谱。测定了Eu原子偶宇称,能量在45740.3—47341.0cm^-1范围的75个能级位置,识别了收敛于Eull 4f⁷6s ⁷S₃的4f⁷6s(⁷S)np(n=12—46)的自电离里德伯系列。报道了这一系列在此能量范围的能级位置及量子亏损数据。 关键词：     

Narrow 3-photon autoionizing resonances in Tl and Yb

Narrow autoionizing resonances have been observed in Yb and Tl using direct 3-photon excitation of ground state atoms. The linewidth is 0.9 cm^-1 in Yb and 0.4 cm^-1 in Tl. Autoionizing levels in both atoms correspond to doubly excited electronic states. This is the first observation of such states in Tl.     

利用自电离探测技术研究Sm原子Rydberg态光谱

采用孤立实激发与自电离探测技术相结合的方法对Sm原子偶宇称高激发态进行了系统研究.按照不同的自电离通道将所测数据进行了分类和比较,并进行了详细讨论.不仅报道了许多收敛于不同电离限的Rydberg态的能级位置和跃迁的相对强度等信息,而且还把处于同一能域内的Rydberg态和价态进行了辨识.另外,不但提供了一种有效识别不同类型的高激发态的鉴别技术,而且还对处于41800 cm^-1到43800 cm^-1能域内的Rydberg态和价态的光谱特性进行了详细分析和讨论. 关键词： 自电离探测 Rydberg态 Sm原子     

Two-color photoionization spectroscopy of uranium in a U–Ne hollow cathode discharge tube

A U–Ne hollow cathode discharge tube is used as a source of uranium atomic vapors as well as a photoelectron/photoion detector for carrying out two-color three-photon photoionization spectroscopy of uranium. Using the uranium excitation transition 0 cm⁻¹ (⁵L ₆ ⁰ ) → 16 900.38 cm⁻¹ (⁷M₇) at 591.5-nm laser wavelength as a first step transition and scanning the wavelength of a second laser from 558 to 568 nm, high-lying odd-parity atomic levels of uranium are studied in the energy region 34 500–34 813 cm⁻¹. All the expected 21 odd-parity atomic levels identified by various researchers in this region are observed in a single spectrum, demonstrating the high sensitivity achieved therein. In addition to this, we have identified eight autoionization resonances of uranium starting from its odd-parity atomic level at 33 801.06 cm⁻¹ pumped by two-photon excitation. Four out of these eight autoionization resonances are observed for the first time.     

新型激光晶体Yb:KY(WO4)2的结构与光谱

采用顶部籽晶提拉法，以K₂W₂O₇为助溶剂，生长了Yb:KY(WO₄)₂新型激光晶体.经热重-差热分析，确定晶体熔点为1045℃，相变温度为1010℃.X射线粉末衍射测试，验证所生长的晶体为β-Yb:KY(WO₄)₂.晶体结构分析确定Yb:KY(WO₄)₂晶体由WO₆八面体连接而成，WO₆八面体是由双氧桥(WOOW)及单氧桥(WOW)构成.晶体粉末样品室温下的红外及拉曼光谱测试，确定WO₆原子基团、双氧桥及单氧桥的振动频率.晶体的吸收峰位于940nm，980nm，发射峰位于989nm—1030nm. 关键词： 晶体结构 光谱 晶体生长     

Observation of autoionization resonances in uranium by step-wise laser photoionization

A large number of autoionization resonances have been observed in uranium in the energy range 50,590–51,560cm^–1 by two-step three-photon ionization technique, using two copper vapor laser pumped dye lasers. A Rydberg series converging to the ionization limit of UII at 1749cm^–1 (⁶ L _13/2) has been identified. Some of these resonances are very narrow with a fwhm of 0.1cm^–1. Possible origins of these are discussed.     

Investigation of odd-parity Rydberg states of Eu I with autoionization detection

Isolated-core-excitation (ICE) scheme and autoionization detection are employed to study the bound Rydberg states of europium atom. The high-lying states with odd parity have been measured using the autoionization detection method with three different excitation paths via 4f⁷6s6p[ ⁸P_5/2], 4f⁷6s6p[ ⁸P_7/2] and 4f⁷6s6p[ ⁸P_9/2] intermediate states, respectively. In this paper the spectra of bound Rydberg states of Eu atom are reported, which cover the energy regions from 36000~cm^-1 to 38250~cm^-1 and from 38900~cm^-1 to 39500 cm^-1. The study provides the information about level energy, the possible J values and relative line intensity as well as the effective principal quantum number n^* for these states. This work not only confirms the previous results of many states, but also discovers 11 new Rydberg states of Eu atom.     

Nuclear orientation of171Lu and173Lu

The decays of¹⁷¹Lu and¹⁷³Lu have been studied by means of nuclear orientation. External perturbations of two¹⁷¹Yb levels have been observed. Unambiguous spin assignments have been made for several levels in¹⁷¹Yb and mixing ratios of the transitions in¹⁷¹Yb and¹⁷³Yb have been deduced. The properties of the¹⁷¹Yb and¹⁷³Yb rotational bands have been studied using the quasiparticle-phonon model including a Coriolis interaction.     

Bulk crystal growth and efficient diode-pumped laser performance of Yb3+:Sc2SiO5

A bulk crystal of Yb:Sc₂SiO₅ (Yb:SSO) with favorable thermal properties was successfully obtained by the Czochralski method. The energy level diagrams for Yb:SSO crystal were determined by optical spectroscopic analysis and semi-empirical crystal-field calculations using the simple overlap model. The full width at half maximum of the absorption band centering at 976 nm was calculated to be 24 nm with a peak absorption cross-section of 9.2×10^-21 cm². The largest ground-state splitting of Yb³⁺ ions is up to 1027 cm^-1 in a SSO crystal host. Efficient diode-pumped laser performance of Yb:SSO was primarily demonstrated with a slope efficiency of 45% and output power of 3.55 W.