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1.
Two-colour stepwise excitation and photoionization schemes are adopted to study the spectra of high-lying states of the Sm atom. These bound even-parity states are excited with three different excitation paths from the 4f66s6p7DJ (J = 1, 2, 3) intermediate states, respectively. They are probed by photoionization process with an extra photon driving them to the continuum states. In this experiment, 270 states are detected in an energy range from 36160 cm-1 to 42250 cm-1, 109 of which are newly discovered, while the rest of them are confirmed to be the energy levels reported previously. Furthermore, based on the J-momentum selection rules of three excitation paths, a unique assignment of J-momentum for all observed states is determined, eliminating all remaining ambiguities in the literature. Finally, 53 single-colour transitions originating from the scanning laser are also identified. For all the relevant transitions, the information about their relative intensities is also given in the paper. 相似文献
2.
Spectra of autoionizing states of the Sm atom in an energy region between 45948.9 cm-1 and 46943.6 cm-1 are systematically investigated by a three-color multi-step resonant excitation scheme with three different excitation paths.The three intermediate states,4f 66s7s 7F3,4f 66s7s 7F4,and 4f 66s7s 9F5 are employed for the three paths,respectively.Based on precise calibration of wavelength,the level energies of 112 autoionizing states are determined with the line widths and the relative line intensities of the related transitions.The possible influence of configuration interaction on the line shape of autoionizing state is also discussed.In addition,a unique value of J,the total angular momentum,is assigned to all detected states by comparing the three spectra obtained with the different excitation paths. 相似文献
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4.
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[ 8P5/2], 4f76s6p[ 8P7/2]
and 4f76s6p[ 8P9/2] 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. 相似文献
5.
6.
LI Ming DAI ChangJian & XIE Jun Key Laboratory of Display Materials Photoelectric Devices Ministry of Education Tianjin China School of Science Tianjin University of Technology Tianjin 《中国科学:物理学 力学 天文学(英文版)》2011,(6)
The odd-parity high-lying states of the Sm atom are investigated systematically by a three-color resonant excitation scheme with two different excitation paths.The two intermediate states,4f 6 6s7s 7 F 0 and 4f 6 6s7s 7 F 1 are employed for paths I and II,respectively.Fifty-seven bound states are detected with paths I and II in the energy range between 44188 and 45515 cm 1,while 64 autoionizing states are found in the energy range from 45528 to 45761 cm 1.Not only the level energies of all observed states,b... 相似文献
7.
Wen-Jie Qin Chang-Jian Dai Ying Xiao 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(1):63-70
In this work, 4f 66pnl and 4f 55d6snl (l=0,2) autoionizing states of the samarium (Sm) atom, especially those with lower principal quantum number, have been studied, using the isolated-core excitation scheme with three dye lasers. In the energy region between 57 990 and 61 030 cm−1, there are 74 autoionizing states of the Sm atom observed. These states can be classified into the autoionization series converging to four different ionization limits. In most cases, the line shapes of these autoionizing states are nearly symmetric, from which the level energies and widths can be easily obtained by fitting the experimental spectra to the Lorentzian profiles. In addition, several spectroscopic properties of these autoionizing states, such as configuration interaction, are also discussed. 相似文献
8.
采用光电离探测方法,对钐原子奇宇称束缚激发态进行了系统研究.通过设计三条不同的激发路径, 采用共振激发方式,先将钐原子分三步从基态激发到不同的束缚激发态,然后采用光电离手段对其进行探测. 通过对第三步激发光的波长进行大范围的扫描,在同一能域内获得了三组不同的光谱. 通过比对三条路径所得到的三组光谱,不仅精确确定了大量奇宇称束缚激发态的能级位置, 而且还获得了相应跃迁的相对强度的信息.最后,通过运用三条不同的激发路径的选择定则, 还确定了上述能级的总角动量.
关键词:
钐原子
束缚激发态
奇宇称
光电离探测 相似文献
9.
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 相似文献
10.
采用双色三步激发和光电离过程,对Sm原子的偶宇称高激发态的光谱进行了研究.先采用两条激发路线分别将Sm原子两步共振激发至待测的高激发态,然后利用光电离技术对其进行探测.分别将第一束激光的波长固定在627.50nm和624.41nm上,以便将Sm原子从亚稳态共振激发到由4f66s6p电子组态所构成的两个原子状态上.第二束激光在440-700nm的波段范围内扫描,不仅使Sm原子在30040-38065cm-1能域内的偶宇称高激发态上布居,将其进一步光电离,测量了其光谱.通过光谱定标和选择定则等分析手段,本工作不仅精确获得了136个态的能级位置,而且也唯一确定了其总角动量,并且给出了相关跃迁的相对谱线强度. 相似文献
11.
G. Cabello L. Lillo B. Chornik R. del Río 《Journal of Physics and Chemistry of Solids》2010,71(9):1367-1372
Thin films of ZrO2 loaded with 10, 30 and 50 mol% Sm were prepared by a photochemical method using thin films of metal acetylacetonate complexes as precursors. The photolysis of these films induces the fragmentation of the acetylacetonate ligand and the partial reduction of metal ion together with volatile organic compounds. When the metallic complex is exposed to air, the product of the reaction is metal oxide. The photoreactivity of these films was monitored by FT-IR spectroscopy, followed by a post-annealing treatment process. The obtained films were characterized by X-ray photoelectron spectroscopy and atomic force microscopy.Photoluminescense studies of the films employed 400 nm radiation for excitation of the Sm ions present. The emission spectra showed signals arising from the 4G5/2→6HJ (J=3/2, 7/2, 9/2) transitions, where the 4G5/2→6H3/2 transition has the highest intensity. The concentration dependence of the PL intensity was also studied. A maximum PL intensity was observed with 10 mol% Sm content but then diminished with higher Sm concentrations. 相似文献
12.
<正>Using the isolated-core-excitation scheme and three-step laser resonance ionization spectroscopy approach,this paper,for the first time,has systematically investigated the autoionization spectra of atomic Sm,belonging to the 4f~66pnl and 4f~55d6snl(l=0,2) configurations.In the experiment,the first two tunable dye lasers are employed to excite the Sm atom from its initial state to the different 4f~66snl bound Rydberg states,then the third dye laser is scanned to drive the atom to the doubly-excited autoionizing states.With the above excitation scheme,the measured transition profiles of the autoionizing states are nearly symmetric,from which the level energies and widths can be easily obtained. 相似文献
13.
In this work, a three-step autoionization detection method and direct
photoionization detection method are employed to measure the highly
excited even-parity states of the Sm atom in the energy region
between 36360~cm-1 and 40800~cm-1. Comparisons between
the results from the two detection techniques enable us to
discriminate the Rydberg states from the valence states in the same
energy region with the information of level energies, possible J
values and their relative intensities. Furthermore, in the
experiment two different excitation schemes are designed to obtain
the spectra of highly excited even-parity states of the Sm atom.
With a detailed analysis of the experimental data, this work not
only confirms the results about many spectral data from the
literature with different excitation schemes, but also reports new
spectral data on 29 Rydberg states and 23 valence states. 相似文献
14.
《Nuclear Physics A》1997,613(3):209-236
The reaction 148Sm(p,t)146Sm was studied at Ep = 26 MeV. Fifty-six excited states in the final N = 84 nucleus were observed below Eexc = 4.2 MeV and their angular distributions were measured at 8 angles. Spin and parity assignments are made for 37 of them, based on the determination of the transferred angular momentum L. Ten excited Jπ = 0+ states were identified. The emerging excitation energies of the Jπ = 0+ states and the monopole strength distribution in 146Sm are compared with those observed in nearby nuclei and with results of calculations done in the framework of the Particle-Core Coupling Model. The main features of the experimental results are interpreted using a superposition of two types of configurations: two-particle states coupled to the collective excitations of the N = 82 core and two holes coupled to the collective excitations of the N = 86 core. Calculations show also that two-phonon⊗two-particle configurations are spread over many states and their identification becomes difficult. 相似文献
15.
Luminescence spectra and excitation spectra in 150-420 nm spectral region have been recorded at room temperature for polycrystalline sample of (0.5%)Eu3+:CsGd2F7. The relatively intense emission has been observed from 5D3, 5D2 and 5D1 levels. Emission and excitation spectra prove that the excitation energy is efficiently transferred from the 6GJ and 6IJ levels of Gd3+ ions to Eu3+ ions. The visible quantum cutting via downconversion has been detected, with efficiency of the cross-relaxation step of ∼50%. 相似文献
16.
W.J. Qin C.J. Dai Y. Xiao 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(7-8):997-1004
The investigation of the samarium (Sm) atom autoionizing states, belonging to the 4f6 6pnl and 4f5 5d6snl (l=0, 2) configurations, has been carried out by using a three-step isolated-core-excitation (ICE) scheme. Fifty-seven new autoionizing states of the Sm atom have been observed in the energy region between 60,700 and 66,500 cm?1. These autoionizing states are classified into five autoionization series in the light of different ionization limits. In most cases, the transition profiles of these autoionizing states are nearly symmetric, from which the peak positions and widths can be easily obtained by Lorentzian-profile-fitting procedure. Some autoionizing states have multi-peak profiles whose spectroscopic properties are analyzed in order to understand the complicated structures. 相似文献
17.
Lithium cesium mixed alkali borate glasses of the composition 67B2O3·xLi2O·(32−x)Cs2O (where x=8, 12, 16, 20 and 24) containing 1 mol% Nd2O3 were prepared by melt quenching. The absorption spectra of Nd3+ were studied from the experimental oscillator strengths and the Judd-Ofelt intensity parameters were obtained. The intensity parameters are used to determine the radiative decay rates (emission probabilities of transitions) (AT), branching ratios (β) and integrated absorption cross-sections (Σ) of the Nd3+ transitions from the excited state J manifolds to the lower lying J′ manifolds. Radiative lifetimes (τR) are estimated for certain excited states of Nd3+ in these mixed alkali borate glasses. Luminescence spectra were measured and the emission cross-sections (σp) were evaluated for the three emission transitions. The variation of luminescence intensity with x was recorded for the three transitions at different excitation power to see the effect of mixed alkalies in these borate glasses. 相似文献
18.
Measurements of the inelastic scattering of 30 MeV protons from 138Ba and 144Sm have been carried out with 7–10 keV energy resolution. Differential cross sections were measured for levels up through 3.4 MeV excitation energy. For most of these states Jπ assignments are suggested on the basis of angular distributions distinctly characteristic of angular momentum transfer L = 2, 3, 4,or 6. 相似文献
19.
The frequencies of 5s 3 S 1-np 3 P 1 Rydberg transitions, quantum defects for n=15–50, and energies of high-lying P states of the Zn atom were measured by three-step laser excitation with subsequent ionization by a pulsed electric field. Free Zn atoms were produced through effusion of Zn vapor from an atomizer during the thermal dissociation of ZnS molecules. The evaporation kinetics was studied, and the ZnS vapor pressure was measured by the detection of photoionic signals of Zn. 相似文献
20.
The emission spectra of single and polyterbium centers have been measured at the excitation of CaSO4:Tb3+ phosphors with different charge compensators (Na+, calcium vacancies, etc.) by 3.8–35 eV photons or 5 and 300 keV electrons at 6–300 K. The possible mechanisms providing quantum yield above unity for green (5D4 → 7FJ) and blue emission (5D3 → 7FJ) of Tb3+ at the direct intracenter excitation, excitation of oxyanions or creation of hot (nonrelaxed) electrons and holes have been discussed. On the basis of thermally stimulated luminescence at 6–600 K, the peculiarities of the hopping diffusion of relaxed electrons and holes and their tentative low-temperature self-trapping have been considered. 相似文献