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1.
滕华国  徐至展  胡畏  王炎森  方渡飞 《物理学报》1996,45(11):1788-1792
在扭曲波库仑玻恩交换近似下计算了类钠铜离子2p3s+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:  相似文献   

2.
在He+离子和Ar原子碰撞过程中,同样存在着电子俘获激发和直接激发两种过程。本文把实验结果同He+离子和Ne原子碰撞体系进行了比较,发现:在入射离子速度较小时,实验所得到的Hel三重态发射截面要大得多;当入射离子He+的速度大于一个原子单位(2.2×108cm/s)时,情况则相反。因此,在俘获电子过程中,势能亏损同He+离子的入射速度是两个非常重要的因素,而且它们之间存在一个竞争过程。入射离子He 关键词:  相似文献   

3.
本文通过观测Ne+离子与Li原子碰撞中的发射谱,对碰撞中的电子俘获和靶激发过程进行了研究。在可见光范围给出了所观察到的各条谱线的发射截面及相应上能级的激发截面。对电子俘获过程与能量亏损和靶原了电离势的关系进行了讨论。Ne+离子能量范围为20—150keV 关键词:  相似文献   

4.
本文用荧光法测量Rb(62D)原子与基态Rb原子,H2分子碰撞转移截面。结果表明:Rb(62D)-Rb(52s)转移截面为σfs=67×10-14cm2tr=4.3×10-14cm2,Rb(62D)—H2转移截面为σfs 关键词:  相似文献   

5.
赵洪英  戴长建  关锋 《物理学报》2009,58(1):215-222
采用两步激发共振光电离技术研究了Sm原子的偶宇称高激发态光谱.实验采用了两条激发路线:1)第一束激光的波长固定在478.44nm以便将Sm原子从4f66s27F1]态激发至4f66s6p[7D1]态,再用第二束激光使其波长从480nm扫描至530nm,将Sm原子进一步激发至待测的高激发态;2)第一束激光的波长固定在574.8 关键词: Sm原子 光谱 分步激发 共振电离  相似文献   

6.
原子激发态的二体电子关联变分计算   总被引:1,自引:0,他引:1       下载免费PDF全文
范永昌  李名生  李白文 《物理学报》1988,37(10):1633-1639
本文将Wilets等人提出并由作者加以改进的二体电子关联变分方法推广到多电子原子一般激发态结构的计算。对He原子及其等电子系列(1s)(nl)电子组态的激发单重态n1L、三重态n3L,Be原子及其等电子系列(1s)2(2s)(nl)3L和B原子(1s)2(2s)2(nl)2L等激发态进行了计算,结果表明:这种方法的波函数结构简单,便于应用,不仅计算量小, 关键词:  相似文献   

7.
本文在q×(20—150)keV的能量范围内,通过光学测量,对He+和He2+离子与碱余属原子Li碰撞过程中的靶激发过程进行了研究。由光学多道分析系统(OMA),测得LiI 670.8nm(2p→2s),LiI610.4nm(3d→2p),LiI460.3nm(4d→2p)和LiI812.6nm(3s→2p)谱线。给出所观察到的谱线的发射截面和相立的Li(2p)激发截面。对He+与Li碰撞过程,LiI670.8nm谱线发射截面与Aumayr 关键词:  相似文献   

8.
双电荷离子He2+与Ne,Ar原子碰撞中的激发态   总被引:1,自引:0,他引:1       下载免费PDF全文
实验用光学多道分析系统(OMA)测量了He2+和Ne,Ar碰撞过程中的发射光谱,结果表明,这些碰撞体系存在着三种激发过程:双电子俘获激发过程、单电子俘获激发过程和直接激发过程。给出了HeI,HeII,NeI,NeII和ArI,ArII谱线的发射截面,并对He2++Ne和He2++Ar两个碰撞体系的发射截面作了一些比较,发现在入射离子速度相同的情况下,后者的发射截面要比前者大得多,并对此进行了定性讨论。OMA的光谱波长范围为200—800nm。入射离子He2+的能量范围为140—340keV。 关键词:  相似文献   

9.
He+离子和Ne原子碰撞过程中激发态的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
在He+离子和Ne原子碰撞过程中,我们发现两种碰撞激发过程,一种是电子俘获激发过程,另一种是直接激发过程。本实验用光学多道分析系统(OMA)对这些过程进行了光学测量,给出了发射截面数据。入射离子实验室能量范围为70—150keV。 关键词:  相似文献   

10.
Ru原子高Rydberg态研究   总被引:1,自引:0,他引:1       下载免费PDF全文
本文描述用激光共振激发-场电离实验方法测定Ru原子的4d7(4F)ns(n=28—45)和4d7(4F)nd(n=26—48)系列Rydberg能级,并应用非线性拟合得到了Ru原子的第一电离阈值。采用相对论性自洽场方法对所得能级以及相应的量子亏损作了计算,理论与实验结果符合得很好。此外还将本文所得的第一电离阈值与已有数据作了比较。 关键词:  相似文献   

11.
本文通过光学方法,在q×(20—140)keV能量范围内,研究了He+和He2+离子与碱金属原子Na碰撞中的靶激发过程。通过光学多道分析系统(OMA),对He+与Na碰撞过程,观察到NaI589.0+589.6nm(3p→3s),NaI818.3nm(3d→3p)和NaI568.8nm(4d→3p)等谱线。对He2+与Na碰撞过程,只观察到NaI589.0+589.6nm谱线。计算了所有观察到的谱线的发射截面和Na(3 关键词:  相似文献   

12.
李大万  潘广炎  杨锋 《物理学报》1996,45(9):1444-1449
用发射光谱法研究了同种元素氮的分子离子N+2和原子离子N+与Ne原子碰撞产生的激发态,获得了靶激发、入射分子离子的分解激发、入射原子离子的激发以及两种离子与靶之间的电荷转移激发等信息.计算了各发射谱线的发射截面.对两种离子引起的谱线发射截面的差异进行了分析,得出一些初步结论,并对此作了些定性解释  相似文献   

13.
The cross sections for proton capture by 11B to the ground and excited states of 12C have been measured in the proton energy interval between 18 and 43 MeV. The ground-state cross section shows good agreement with theoretical calculations including correlations. Capture photons have also been observed to all the residual 1p-1h states of 12C having a dominant 1p?132 hole: the corresponding cross sections systematically show a giant resonance whose energy increases with the increasing excitation energy of the “background” level. The resonances at 27.4, 31, 33.2, 37 and 43 MeV, seem to show observable interference effects.  相似文献   

14.
Using the effective operator formalism, the importance of ground-state correlations on photonuclear cross sections is studied. For purposes of orientation, a bound-state calculation is first performed to take into account the mixing of 2p-2h and 3p-3h configurations into the 1p-1h dipole states. Inclusion of these configurations is found to affect the energies of the 1p-1h states in opposite directions and the combined effect, including that on the transition strengths, is negligible. Most of the reduction in the absorption comes from the ground-state correlations of which the A-dependence is examined with a model interaction. We then proceed to calculate the excitation function for the reactions using effective dipole matrix elements obtained from the continuum wave functions of the coupled-channels calculation. Application to the case of 16O leads to a reduction of about 25 % in the cross sections.  相似文献   

15.
The excitation cross sections of transitions from the 3 P o and 3 D o levels of a nickel atom in electron-atom collisions at an exciting-electron energy of 50 eV have been analyzed by the method of extended crossing beams with detection of the optical signal from excited atoms. Eleven optical excitation functions have been recorded in the electron-energy range of 0?C200 eV. The direct excitation cross sections of the energy levels and the contribution of the cascade transitions were calculated using the data obtained.  相似文献   

16.
The 210Po(t, α)209Bi reaction has been studied at 20 MeV triton energy with an overall resolution of 20 keV FWHM. Absolute cross sections were established by a comparison of the (t, α) intensities to elastic triton scattering. The three lowest single-proton states in 209Bi were observed and spectroscopic factors were extracted from the measured cross sections by DWBA analysis. Starting at 2.43 MeV, six levels were strongly excited. These states have large 2p-1h proton components. The spectroscopic factors were extracted by a comparison of 210Po(t, α) cross sections to 208Pb(t, α)207T1 single-proton-hole cross sections measured previously at the same bombarding energy. The observed states and their properties were analyzed within the framework of the particle- (or hole) vibration coupling model. Surface vibrational states in 208Pb coupled to single protons as well as the proton pair addition modes (states in 210Po) coupled to a proton-hole were included in the analysis.  相似文献   

17.
High resolution proton energy spectra from the 4He(γ,p) reaction have been measured with tagged photons in the range Eγ = 130–525 MeV using the large Mainz NaI(Tl) spectrometer at \([Theta _p^{lab} = 37.1^circ ]\) . Three separate reaction channels were identified, viz. 4He(γ,p)t two-body breakup, 4He photodisintegration via two-nucleon photon absorption processes and the quasifree pion production channel. Differential cross sections are presented for each of these channels as a function of photon energy. The sum of the two-nucleon photon absorption and the quasifree pion production differential cross sections, in the CM system, resembles that of the corresponding free-nucleon differential cross section when Fermi motion is taken into account.  相似文献   

18.
New measurements of the photoionization cross sections from the 4p 2P1/2,3/2, 5d 2D5/2,3/2 and 7s 2S1/2 excited states of potassium are presented. The cross sections have been measured by two-step excitation and ionization using a Nd:YAG laser in conjunction with a thermionic diode ion detector. By applying the saturation technique, the absolute values of the cross sections from the 4p 2P3/2 and 4p 2P1/2 states at 355 nm are determined as 7.2±1.1 and 5.6±0.8 Mb, respectively. The photoionization cross section from the 5d 2D5/2,3/2 excited state has been measured using two excitation paths, two-step excitation and two-photon excitation from the ground state. The measured values of the cross sections from the 5d 2D5/2 state by two-photon excitation from the ground state is 28.9±4.3 Mb, whereas in the two-step excitation, the cross section from the 5d 2D3/2 state via the 4p 2P1/2 state and from the 5d 2D5/2,3/2 states via the 4p 2P3/2 state are determined as 25.1±3.8 and 30.2±4.5 Mb, respectively. Besides, we have measured the photoionization cross sections from the 7s 2S1/2 excited state using the two-photon excitation from the ground state as 0.61±0.09 Mb.  相似文献   

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