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Employing recently developed magneto-optical trap recoil ion momentum spectroscopy(MOTRIMS) combined with cold atoms,strong laser pulse,and ultrafast technologies,we study momentum distributions of the multiply ionized cold rubidium(Rb) induced by the elliptically polarized laser pulses(35 fs,1.3×1015 W/cm2).The complete vector momenta of Rbn+ ions up to charge state n=4 are recorded with extremely high resolution(0.12 a.u.for Rb+).Variations of charac...  相似文献   
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Electron scattering from argon in a laser field is investigated empolying the second-order perturbation theory. The absolute differential cross sections of e-Ar scattering with multiphoton exchange in special scattering geometries G1 (for small-angle scattering) and G2 are calculated. Our results are found to be better than other theoretical results as compared with the experimental data.  相似文献   
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Asymmetry parameter β2 for photoionization of helium leaving the He+ ion in the n=2 level and differential cross sections(DCSs) in the n=2,3,4 levels with photon emission angle θ=900 are provided at photon energies 69-76.8 eV employing the R-matrix method with a 20-term target representation, in which five polarization orbitals \bar{6}l are included. The asymmetry parameter β2 and the DCS, in the n=2 level in the region of 69-73 eV, are in good agreement with available experimental and theoretical results. Above the n=3 threshold, we present new theoretical results along with measurements. No theoretical and experimental results can be used to compare with the present calculations of the DCSs for photoionization into the He+ ion in the n=3,4 levels.  相似文献   
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Asymmetry parameterβ2 for photoionization of helium leaving the He+ ion in the n = 2 level and differential cross sections(DCSs) in the n = 2, 3, 4 levels with photon emission angle θ=90°are provided at photon energies 69-76.8 eV employing the R-matrix method with a 20-term target representation, in which five polarization orbitals 6l are included. The asymmetry parameter β2 and the DCS, in the n=2 level in the region of 69-73eV, are in good agreement with available experimental and theoretical results. Above the n = 3 threshold, we present new theoretical results along with measurements. No theoretical and experimental results can be used to compare with the present calculations of the DCSs for photoionization into the He+ ion in the n = 3, 4 levels.  相似文献   
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电子被氩,氪,氙原子散射总截面的光学模型研究   总被引:1,自引:0,他引:1  
文中基于光学模型势方法,详细分析并改进了一种准自由模型吸收势,把它作为光学模型的虚部,在能量0.1-300eV的范围内计算了电子被Ar,Kr,Xe原子散射的总截面,计算结果与实验值进行了比较。  相似文献   
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We present an approach,a Terahertz streaking-assisted photoelectron spectrum(THz SAPS),to achieve direct observations of ultrafast coherence dynamics with timescales beyond the pulse duration.Using a 24 fs probe pulse,the THz SAPS enables us to well visualize Rabi oscillations of 11.76 fs and quantum beats of 2.62 fs between the 5S1/2 and 5P3/2 in rubidium atoms.The numerical results show that the THz SAPS can simultaneously achieve high resolution in both frequency and time domains without the limitation of Heisenberg uncertainty of the probe pulse.The long probe pulse promises sufficiently high frequency resolution in photoelectron spectroscopy allowing to observe Autler-Townes splittings,whereas the streaking THz field enhances temporal resolution for not only Rabi oscillations but also quantum beats between the ground and excited states.The THz SAPS demonstrates a potential applicability for observation and manipulation of ultrafast coherence processes in frequency and time domains.  相似文献   
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利用二阶微扰论的方法计算了动量转移与激光场的偏振方向垂直条件下,电子-He原子碰撞的自由-自由跃迁的单光子和两光子交换的微分截面,结果与最近的实验结果符合得很好。  相似文献   
9.
最近的CO2激光辅助电子-原子碰撞的测量结果与K-W公式存在着非常大的差异,用玻恩近似理论对此进行了详细的研究.结果表明第二玻恩近似结果与实验结果符合得比较好,K-W公式的预言只相当于第一玻恩近似.同时,计算表明电子-原子间的极化势在激光辅助电子-原子散射过程中起着重要的作用. 关键词:  相似文献   
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模拟仿真了速度成像谱仪中解离电子/离子飞行运动轨迹,获得电子/离子动量三维分布的真实图像,针对时间戳相机Tpx3Cam在动量分布探测成像中存在的团簇效应问题,发展了适用于高计数率情况下的中心算法。仿真结果显示,提出的中心算法可以减少约一个数量级的数据容量,并让单像素位置精度提高到0.1像素,实现了粒子动量分布的超分辨位置成像。模拟ns态电子电离和N2分子(1,1)通道库伦爆炸实验,发现中心算法能够使电子平行于探测器平面的动量分辨提升30%;使库伦爆炸产生的N+飞行时间谱分辨提升80%。同时,在具有背景气体干扰情况下,对CO分子库伦爆炸产物离子进行半径协方差分析,提出的中心算法成功观测到C+和O+的关联。  相似文献   
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