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通过非线性变换和特殊设计结点的B样条函数方法研究计算了囚禁于巴基球内的钠原子的里德堡能级结构和振子强度.计算结果表明,巴基球等效势阱深度可以有选择的影响和改变里德堡原子的特性. 相似文献
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在球坐标下采用基组展开方法计算了均匀磁场中的氢原子高Rydberg态能谱和振子强度谱.径向和角向均采用高阶B样条基组. 径向采用B样条基组能很好地描述束缚态与连续态的耦合;角向采用B样条基组有效地减少了基组维数,计算效率得到大幅度提高. 用上述方法计算了磁场中氢原子Rydberg态-40cm-1到零场电离阈的高精度抗磁谱并与已有理论和实验结果作了比较. 该方法适用于低于离化阈的所有能区的精确谱计算并易于推广到非氢原子、交叉场中的原子以及高于离化阈的正能区光谱的计算.
关键词:
氢原子
B样条基组
能谱
振子强度谱 相似文献
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用多组态Dirac-Fock方法,并系统考虑相对论效应、电子关联、弛豫效应等重要贡献,计算了NII离子2s22p3s 3P1—2s22p21D2和2s22p3s 1P1—2s22p23P0,1,2自旋禁戒跃迁概率和振子强度-通过比较计算证实:弛豫和关联效应对禁戒跃迁概率的影响非常大,考虑了这些效应后,计算结果有显著的改善-由跃迁概率和振子强度的计算值推断,2s22p3s 3P1—2s22p21D2的谱线强度应该比原有的理论预言值小-
关键词:
跃迁概率
多组态Dirac-Fock方法 相似文献
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囚禁于巴基球内的原子的里德堡特性 总被引:1,自引:0,他引:1
通过非线性变换和特殊设计结点的B样条函数研究计算了囚禁于巴基球内的氢原子里德堡能级结构和振子强度 .结果表明 ,巴基球等效势阱深度可以有选择的影响和改变里德堡原子的特性 ;囚禁原子拥有很多自由原子所没有的奇特性质. Rydberg energy levels and oscillator strength of endohedrally confined H atom have been calculated by using a nonlinear algebraic mapping technique and B-spline method.The boundary conditions are conveniently satisfied with a specially designing knot sequence.Our results show that endohedral can selectively alter the properties and energy levels of Rydberg atoms, and such atoms possess some properties and behaviours which are not previously met or studied in free systems. 相似文献
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本文探讨了快电子碰撞下判别原子跃迁多极性的方法,指出了从实验上由广义振子强度比和光学振子强度比及中间耦合系数的归一化特性来确定中间耦合系数的方法.然后以氩原子为例,计算了其价壳层激发的中间耦合系数,并在2500 eV入射能量下实验测量了氩原子跃迁到3p54s[3/2]1和3p54s′[1/2]1的广义振子强度比,在此基础上阐明了氩原子价壳层激发的多极性,从实验上获得了氩原子3p54s[3/2]1和3p54s′[1/2]1的中间耦合系数.本文得出了LS耦合的波函数足以描述氩原子的光子或快带电粒子碰撞激发过程的结论,这是由于氩原子基态的LS耦合特性在快电子激发过程中选择了激发态波函数中的单态成份决定的.并指明该结论可以推广到描述其它原子的光子或快带电粒子的碰撞激发过程. 相似文献
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G. Blüge K. Langanke H. G. Reusch C. Rolfs 《Zeitschrift für Physik A Hadrons and Nuclei》1989,333(2):219-227
We have performed a microscopic study of the3He(d,p) α reaction at astrophysical energies within the framework of the Resonating Group Method adopting three different effective nucleon-nucleon interactions. The calculations suggest that the low-energy3He(d,p) α cross section is in good approximation given by the contribution arising from the 3/2+ resonant state atE R =245 keV. In fact, the low-energy data can be better (and more physically) described by a single Breit-Wigner resonance parametrization than by a polynomial fit. Our fit to the3He(d,p) α cross section results in a noticeable reduction in the uncertainties of the resonance parameters of the 3/2+ resonant state as well as in a significantly improved extrapolation of the data to astrophysically important energies. On the basis of this extrapolation we were able to quantitatively deduce the enhancement of the low-energy cross section due to electron screening effects from the data of Krauss et al. and Engstler et al. These experimental enhancement factors were compared with various theoretical models which are all based on the Born-Oppenheimer approximation. As the models underestimate the observed enhancement we suggest that the theoretical study of electron screening effects requires a dynamical treatment. 相似文献
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L—shell absorption measurement and simulation of x—ray—heated constrained material 总被引:1,自引:0,他引:1 下载免费PDF全文
Using the newly-designed multi-layered target, we obtain a homogeneous Al sample plasma at high density, low electron temperature, and in near local thermodynamic equilibrium. L-shell resonance absorption lines of Li-like and Be-like ions, as well as satellites are clearly observed. Transition arrays such as 2s-3p, 2s2-2s3p and 2s2p-2p3p are identified. We present the calculation method based on the unresolved transition array model, and we compare the measured transmission spectrum with the calculated results. The electron temperature of the constrained sample plasma is determined to be 34eV with a variation of ±2eV. 相似文献
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The 96Mo(p, n) and 96Mo(p, nγ) reactions have been studied for proton energies between 3.8 and 5.5 MeV. Energy levels in 96Tc up to 632 keV excitation energy have been determined. Possible spin and parity assignments are given for several levels based on the neutron enhancement and angular distributions observed on and off resonance of the isobaric analog state in 97Tc, as well as the observed γ-yields. The first excited state reported at 34 keV was found to be a close doublet only 0.8 keV apart. The observation of this doublet in the (p, n) reaction was used to determine the ground state Q-value Q = ? 3.760±0.010 MeV. 相似文献
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A compound-nucleus mechanism is considered for the reaction where the isobaric analogue resonance (IAR) is populated by a (p, n) stage and decays later emitting a proton p?. It is shown that this mechanism leads to an enhancement in the p? spectra near the IAR energy of the type expected from t · T charge exchange. This phenomenon is general, and will occur whenever the analogue state is not populated selectively in the entrance channel. For the case 91Zr(p, np?)90Zr(g.s.) we estimate the contribution to the cross section due to this mechanism. It is found that the model reproduces the shape of the measured cross section and a normalization consistent with the uncertainties of the data. In order to handle fine-structure properties of the IAR, we develop a version of the external-mixing model particularly adapted for these purposes. 相似文献
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D. Cords D.D. Carmony A.F. Garfinkel F.J. Loeffler L.K. Rangan R.L. Lander D.E. Pellett P.M. Yager F.T. Meiere W.L. Yen 《Nuclear Physics B》1973,54(1):109-116
We have analysed the Kπ spectrum (4 827 events) of the reaction K+n→K+π?p at 9 GeV/c and find evidence of a broad S-wave enhancement which may be interpreted as a resonance. For production of Kπ masses above 890 GeV/c2, we have assumed the dominance of pion exchange. 相似文献
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E. Satoh 《Nuclear Physics B》1976,102(1):51-60
The Λp invariant-mass distribution in the reaction K?d → π?Λp, which is observed Cline et al., has two enhancements: just below the ΣN threshold and just above the ΛN threshold. We have calculated the Λp invariant mass distribution with the two-channel formalism. It has been well discussed in our previous paper that the enhancement just below the ΣN threshold is mainly due to a Λp resonance. In our previous paper, we have interpreted the enhancement just above the ΛN threshold as the two-channel final state interaction or a Λp final state interaction associated with the ΣΛ conversion process. The physical meaning will be intensively discussed in this paper. In fact, we have clearly shown, in this paper, that the effect due to the ΣΛ conversion process is in the enhancement just above the ΛN threshold. If the experimental data should be interpreted by the two-step process K?d → π?(ΣN) → π?Λp, the effect due to the ΣΛ conversion process should have appeared in the experimental data, although some experimental data do not show the enhancement just above the ΛN threshold. 相似文献
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G. M. Ter-Akoopian D. D. Bogdanov A. S. Fomichev Y. T. Oganessian A. M. Rodin S. I. Sidorchuk S. V. Stepantsov R. Wolski P. Roussel-Chomaz W. Mittig H. Savajols M. S. Golovkov A. A. Korsheninnikov I. Tanihata E. A. Kuzmin E. Y. Nikolski A. A. Ogloblin 《Acta Physica Hungarica A》2001,14(1-4):395-404
The angular distribution of 26 MeV/n 8He ions elastically scattered from a gaseous helium target was measured in a wide CM angular range. Results are discussed in terms of the potential scattering and neutron transfer. The angular distributions of elastic scattering as well as 1n and 2n transfer reactions of these ions on protons are presented. Finite-range DWBA calculations made for the 2n transfer reaction leading to the ground (0+) and excited (2+) states of 6He underestimate the cross section for 2n transfer to 6He(0+). Analysis of data for this reaction channel suggests the importance of a direct 5H-cluster exchange process. A resonance state of 5H with an energy of 2 MeV above the decay threshold n+n+ 3H was obtained for the first time by making use of the reaction p(6He,2He)5H. 相似文献
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Sabyasachi Kar Y.K. Ho 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,107(2):315-322
We have investigated the effect of surrounding plasmas on several singly excited and doubly excited meta-stable bound states of helium atom using highly correlated basis functions for singly excited S, P, D states and CI-type basis functions for doubly excited meta-stable D states. Plasma effect is taken care of by using a screened Coulomb (Yukawa) potential obtained from the Debye model that admits a variety of plasma conditions, and such a model plays an important role in plasma spectroscopy. The wavelengths for transitions from the 1snp 1P° (n=2,3)→1s21Se, 1snp 3P° (n=2,3)→1s2s 3Se, 2pnp 1Pe (n=3,4)→1s2p 1P°, 2pnp 3Pe (n=2,3)→1s2p 3P°, 2pnd 1D° (n=3,4)→1s3d 1De, 2pnd 3D° (n=3,4)→1s3d 3De, 2p3p 1Pe→2pnd 1D° (n=3,4), 2pnd 1D°(n=3, 4)→2p4p 1Pe, 2pnp 3Pe (n=2,3)→2p3d 3D°, and 2pnp 3Pe (n=2,3)→2p4d 3D° of helium atom in plasmas for various Debye lengths are reported. 相似文献
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The energy levels of 92Nb were observed in the 92Zr(p, n) reaction by use of the neutron time-of-flight technique. Limits on the spins and parities of the 92Nb levels were placed by observing the enhancement in the relative yield of the final states at an isobaric analog resonance and by the measurement of the relative yield off resonance. The measured enhancements and off-resonance yields are compared with values calculated using the statistical compoundnucleus model. Comparison of results from the two methods is used to obtain spin-parity assignments for nine energy levels lying between 976 and 1739 keV in 92Nb. 相似文献