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1.
姚云飞  陈长进 《中国物理》1999,8(3):167-173
The double differential cross sections for electron impact ionization of helium at incident energies of 200 eV, 100 eV and 64.6 eV have been calculated in the BBK model. The present results are found to be in generally good agreement with the latest measurements of R?der et al. and the theoretical results of the convergent close-coupling method although some quantitative discrepancy remains.  相似文献   
2.
在电子碰撞He原子同时电离同时激发的(e, 2e)反应中,利用DWBA模型,考虑了入射通道基态He原子两种不同的初态波函数,计算了He原子同时电离激发反应的三重微分截面(TDCS),并与实验数据进行比较。结果表明,有关联的Sliverman波函数计算得到的TDCS与实验数据吻合的更好点。  相似文献   
3.
利用标准一阶扭曲波玻恩近似方法(DWBA)计算了共面双对称几何条件下不同能量电子碰撞电离Ne原子的三重微分截面(TDCS),与Nixon和Murray[1]最新的实验测量数据进行比较.当入射电子能量较低时,理论计算结果和实验数据符合较差;而随着入射电子能量的增加,符合程度逐渐改善.  相似文献   
4.
Within the framework of the first-order Born approximation, the triple differential cross sections (TDCSs) for simultaneous ionization and excitation of helium are calculated. The wave function of the ejected electron is chosen to be orthogonal or non-orthogonal to the wave function of the bound electron before ionization. It is found that the orthogonality has a strong effect on the TDCS, especially when plane waves and Coulomb waves are used to describe the projectile and the ejected electron.  相似文献   
5.
EXCHANGE AND FINAL CHANNEL SCREENING EFFECTS IN (e, 2e) PROCESSES   总被引:3,自引:0,他引:3       下载免费PDF全文
陈长进  徐克尊 《中国物理》2001,10(4):290-294
The DS3C model has been improved by taking into account the final channel screening effects. The triple differential cross sections for electron impact ionization of helium at an incident energy of 40 eV are considered. The results of the present DS3C model are compared with the absolute measurements and those of other theoretical models. It has also been shown in which situation the exchange effects are crucial.  相似文献   
6.
低能电子离化He原子(e,2e)反应中的动力学屏蔽   总被引:3,自引:0,他引:3       下载免费PDF全文
在三体索末菲参量修正的基础上,进一步对(e,2e)反应的末态He+中核外电子的有效屏蔽给出修正-这种修正反映了末态四粒子间的动力学屏蔽-并用修正后的索末菲参量计算了入射能量为50eV时,共面不对称几何条件下电子离化He原子的三重微分截面-所得结果与convergent close-coupling理论结果及最新绝对测量的实验数据进行比较,发现当敲出电子能量为10eV时,理论曲线更接近实验数据- 关键词:  相似文献   
7.
陈长进  徐克尊 《中国物理》1999,8(5):331-341
The triple differential cross sections for the ionization of helium from its ground state 11S and metastable states 21S and 23S in coplanar asymmetric geometry by 150, 250 and 400 eV electrons have been calculated in the BBK model. The present results are compared with the experimental data and/or the other theoretical ones. It has been found that the structures for the metastable states differ markedly from those for the ground state. The collision mechanisms for the new structures appearing in the cross sections for the ionization from metastable states have been analysed. And it has been shown how the intensity of recoil peak changes due to the size of the electron orbital. In addition, the optimal kinematical situations for the cross sections are explored for future experiment.  相似文献   
8.
We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The diffraction fringes, i.e., the vertical stripe-like structure, observed in the experimental two-dimensional photoelectron momentum distributions of Gopal et al. (2009 Phys. Rev. Lett. 103 053001) have been attributed to the interplay of the intra- and inter-cycle interferences. The pure numerical calculations by solving the time-dependent Schrrdinger equation are also performed and the results are compared with the experimental measurements directly. It has been found that the position of the stripe-like structure can be used to determine the duration of the laser pulses used in experiments.  相似文献   
9.
利用Berakdar和Briggs对BBK波函数Sommerfeld参数的修正结果,即考虑第三个粒子存在对两个粒子间相互作用的影响,考虑了入射道的库仑相互作用及出射粒子的交换对称性,计算了在共面等能分配几何情况下低能电子碰撞He+(e,2e)反应绝对三重微分截面.结果表明,入射道库仑场对较低的入射能量及小的碰撞参数的三重微分截面影响较大. 关键词:  相似文献   
10.
MOMENTUM CORRELATION OF ELECTRON-HYDROGEN IONIZATION   总被引:5,自引:0,他引:5       下载免费PDF全文
张穗萌  陈长进 《中国物理》1999,8(7):496-502
Following the work of Berakdar, the momentum correlation in the three-body Coulomb continuum problem is considered by the introduction of effective Sommerfeld parameters for both symmetric and asymmetric geometry. The triple differential cross sections for electron impact ionization of atomic hydrogen at incident energies of 54.4 and 150 eV in asymmetric geometry are calculated. Results are compared with the related measurements and the only existing theoretical results of the convergent close-coupling method. They are in good agreement with experiment, though some small quantitative discrepancies remain.  相似文献   
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