共查询到17条相似文献,搜索用时 156 毫秒
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实验研究了钛原子在293~321 nm波段的共振增强多光子电离. 采用激光烧蚀和超声射流相结合的实验技术来制备自由原子,由飞行时间质谱仪实现对钛原子光电离产物的检测. 从离子信号强度对和激光强度的依赖关系导出了钛原子价电子激发态的光电离截面. 实验测量的一些激发态光电离截面在0.2~6.0 Mb. 通过对46Ti、47Ti、48Ti的光电离截面测量研究,没有发现明显的同位素依赖性. 相似文献
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使用R-矩阵方法,采用三态密耦图象计算了锂原子激发态1s^22p^2P的光电离截面,并给出了不同分波及不同过程的截面,计算结果揭示了光电离过程中的Rydberg系列共振,并指出在非共振区光电离截面不是单调变化的。 相似文献
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用共振电离质谱测定铀原子奇宇称高激发态能级 总被引:1,自引:1,他引:0
对铀原子单色和双色多光子共振电离光谱开展了深入的研究。报道了用双色三步共振光电离技术测量位于33003 ̄34264cm^-1范围内的奇宇称高激发态能级的位置。利用总角动量选择定则指定了这些能级的总角动量J值。 相似文献
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铈原子偶宇称自电离态激光共振电离光谱 总被引:1,自引:1,他引:0
给出了利用三色三光子激光共振电离光谱技术研究铈原子偶宇称自电离态的结果。27个有较大跃迁截面高奇宇称激发态被用作第二激发态。第三台染料激光波长在634~670nm范围内扫描,发现了141个偶宇称自电离态能级。为了寻求最佳电离方案,对有较大自电离态能级跃迁截面的各电离路径进行了初步的判定,推荐了8条较佳的电离路径。 相似文献
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拉曼光谱是研究水中生物分子重要的有效方法之一,然而由于拉曼散射截面小,特别是水分子的电子激发态能级高,因此水中生物分子的拉曼光谱测量甚为困难。将液芯光纤技术和共振拉曼技术结合起来,可大幅度提高拉曼光谱强度。实验中用可以获得最大的共振拉曼光谱强度的514.5 nm Ar+离子激光激发,分别用石英和Teflon液芯光纤对水中β-胡萝卜素生物分子进行了痕量检测研究。结果表明应用石英液芯光纤和Teflon液芯光纤可分别检测浓度为10-7~10-9mol·L-1和10-9~10-10mol·L-1的β-胡萝卜素。 相似文献
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V. N. Lokhman D. D. Ogurok E. A. Ryabov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):59-67
We report about effective ionization of iodine atoms and CF3I molecules under the action of intense XeCl laser radiation (308 nm). The only ion fragment resulting from the irradiation
of the CF3I molecules is the I+ ion. We have studied the influence of the intensity, spectral composition, and polarization of the laser radiation used on
the intensity
of the ion signal and the shape of its time-of-flight peak. Based on the
analysis of the results obtained, we have suggested the mechanism of this
effect. The conclusion drawn is that the ionization of the iodine atoms by
the ordinary XeCl laser with a nonselective cavity results from a three- (2 + 1)-photon REMPI process. This process is in
turn due to the presence of accidental two-photon resonances between various spectral components of the laser radiation and
the corresponding intermediate excited states of the iodine atom. The probability of ionization of the atoms from their ground
state I(2P3/2) by the radiation of the ordinary XeCl laser is more than two orders of magnitude higher than the probability of their ionization
from the metastable state I*(2P1/2). The ionization of the CF3I molecules by the XeCl laser radiation occurs as a result of a four-photon process involving the preliminary one-photon dissociation
of these molecules and the subsequent (2 + 1)-photon REMPI of the resultant neutral iodine atoms. 相似文献
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B. B. Zelener S. A. Saakyan V. A. Sautenkov E. A. Manykin B. V. Zelener V. E. Fortov 《Journal of Experimental and Theoretical Physics》2015,121(6):950-954
The spectra of excited lithium-7 atoms prepared in a magneto-optical trap are studied using a UV laser. The laser diagnostics of the energy of Rydberg atoms is developed based on measurements of the change in resonance fluorescence intensity of ultracold atoms as the exciting UV radiation frequency passes through the Rydberg transition frequency. The energies of various nS configurations are obtained in a broad range of the principal quantum number n from 38 to 165. The values of the quantum defect and ionization energy obtained in experiments and predicted theoretically are discussed. 相似文献
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The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained in the range of 420-480 nm with a Nd:YAG pumped optical parametric generator and amplifier. The spectral linescan be attributed to NO X2П(v" = 0, 1) → A2∑(v' = 0, 1) transitions. In this wavelength range, NO molecules are ionized via the resonant intermediate state A2∑+ and by a (2 + 2) REMPI process. The dependence of ion signals on laser intensity and gas pressure is discussed. The variation of the ionization signal versus laser intensity is near quartic. This is in good agreement with theory. 相似文献