We have reinvestigated the B-X and C-X band systems of CuCl by recording the laser- induced fluorescence excitation spectra in 20400-21800 cm^-1. The rotational analyses in Hund＇s case （a） revealed unambiguously a singlet-to-singlet transition nature. The radiative lifetimes were measured to be 4.670 and 4.667 μs, respectively, which are much longer than that expected for a pure singlet of CuCl. This implies that the fluorescence mechanism in the B or C band systems lies in the mixing of the singlets （^1II and ^1E^＋） and triplets （^3II0,1,2） and that the two excited states observed in our experiment might be the singlets that have been strongly ＂contaminated＂ by their triplet neighbors.
Metastable 40Ar＊ atoms are produced in the two metastable states 3p54s [3/2]2 and 3p5 4s′ [1/2]0 in a pulsed DC discharge in a beam, and are subsequently excited to the even-parity autoionizing resonance series 3pSnp′[3/2]1,2, 3p5 np′ [1/2]1, and 3p5nf′[5/2]3 using single photon excitation with a pulsed dye laser. The excitation spectra of the even-parity autoion- izing resonance series from the metastable 40Ar＊ are obtained by recording the autoionized Ar＋ ions with time-of-flight ion detection in the photon energy range of 32500-35600 cm-1 with an experimental bandwidth of 〈0.1 cm-1. A wealth of autoionizing resonances are newly observed, from which more precise and systematic spectroscopic data of the level energies and quantum defects are derived.
Laser-induced fluorescence excitation spectra of jet-cooled CoS molecules have been recorded in the energy range of 15200-19000 cm^-1. Five transition progressions have been reported for the first time, the assignments of these progressions have been derived from a rotational analysis of vibronic bands and they are determined to be [15.58]^4△7/2-X^4△7/2, [16.02]^4△7/2- X^4△7/2, [16.50]^4△7/2-X^4△T/2, [17.80]^4II5/2-X^4△7/2, and [18.00]^4△7/2-X^4△7/2 transitions. In addition, under the supersonic jet condition the fluorescent lifetimes of these vibronic states were measured by exponentially fitting the fluorescence decay. Based on the observed spectra and the measured lifetimes of the vibronic states, the newly identified electronic states are discussed.
The even-parity autoionizing resonance series 5p^5np＇ [3/2]1, [1/2]1, and 5p^5nf＇ [5/2]3 of xenon have been investigated, excited from the two metastable states 5p^56s [3/2]2 and 5p^56s＇ [1/2]0 in the photon energy range of 28000-42000 cm^-1 with experimental bandwidth of -0.1 cm^-1. The excitation spectra of the even-parity autoionizing resonance series show typical asymmetric line shapes. New level energies, quantum defects, line profile indices and resonance widths, resonance lifetimes and reduced widths of the autoionizing resonances are derived by a Fano-type line-shape analysis. The line profile index and the resonance width are shown to be approximately proportional to the effective principal quantum number. The line separation of the 5p^5np＇ autoionizing resonances is discussed.
Based on previous laser-induced fluorescence excitation spectroscopy work, the vibrational constants of neutral FeS in the X5 △ electronic state were obtained by directly mapping the ground-state vibrational levels up to v＂=3 using conventional laser-induced dispersed fluorescence spectroscopy. The vibrational frequency of FeS（X5 △） （518±5 cm-1） agrees well with that reported in a recent PES measurement （520±30 cm-1） [J. Phys. Chem. A 107, 2821 （2003）] which is the only one prior experimental vibrational frequency value for the 5 △ state of FeS. Careful comparisons of our experimental results and those documented in the literature （mainly from theoretical predictions） suggest that the ground state of FeS is 5 △ state.
在单光子29000~40000 cm 1能量范围内,获得亚稳态4p55s[3/2]2和4p55s′[1/2]0Kr原子向其4p5np′[3/2]1,2,[1/2]1和4p5nf′[5/2]3序列自电离Rydberg态跃迁的共振增强激发光谱,光谱线宽≈0.1 cm 1.这些偶宇称自电离态的激发谱呈现明显的不对称线形,如此高分辨的激发谱大部分是首次报道.根据Fano线形关系对激发谱进行系统地分析,获得许多新的系统的能级位置、量子亏损、线性因子、共振宽度、共振态寿命和衰减宽度等数据,基于实验拟合所得的系统参数,我们发现线形因子和共振宽度相对有效量子数呈线性关系.另外还分析了4p5np′序列的能级间距.
