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1.
将光学势方法与可加性规则(additivityrule)相结合,我们计算了能量在10-1000eV范围内正电子被分子(H2,N2,HCl,NH3,CH4,SF6)散射的总截面,计算结果与已有的实验结果进行了比较。  相似文献   

2.
利用可加性规则和作者最近提出的经验公式计算了能量在10eV-1000eV范围内电子被NO2和SO2分子散射的总截面,并对计算结果进行了讨论计算结果与已有的实验和理论结果进行了比较。  相似文献   

3.
500—4250eV电子对CO2的散射全截面绝对测量   总被引:2,自引:0,他引:2  
对中能电子与二氧化碳分子碰撞的散射全截面测量,给出500-4250eV电子对CO2的绝对散射全截面。对测量结果作了曲线拟合,并与已有的实验和理论结果进行了比较  相似文献   

4.
此文采用由原子轨道线性组合构成的自洽场分子轨道(SCF-LCAO-MO),用一级玻恩近似(FBA)计算了能量为100-5000eV的电子与弹性散射的微分截面和全截面。由于采用了Gauss函数的线性组合拟合Slater函数的方法(STO-KG),得到了弹性散射微分截面的解析表达式,使计算大大简化。计算得到的电子和N2,CO散射的总截面和实验结果进行了比较,当入射电子的能量大于1keV时,理论值和实验值之间符合得很好。  相似文献   

5.
低能电子与氩原子散射总截面的绝对测量   总被引:1,自引:0,他引:1  
利用电子散射飞行时间谱仪,测量了1—50eV能量范围的电子与氩原子散射绝对总截面(TCS),测量精度达到5%。实验结果与同类实验和近期的理论结果进行了比较,在实验误差范围内符合得较好。  相似文献   

6.
在准自由电子气模型的基础上得到一种不含自由参数的正电子吸收势,把它作为光学势的虚部,计算了能量在最小非弹性阀值到100eV范围内正电子被He、Ne、Ar原子散射的总截面和能量为200eV和300eV时的散射微分截面,计算结果与实验进行了比较。  相似文献   

7.
此文采用由原子轨道线性组合构成的自洽场分子轨道,用一级玻恩近似计算了能量为100-5000eV的电子与N2(^1Σ^+g、CO(^1Σ^+)弹性散射的微分截面和全截面。由于采用Gauss函数的线性组合拟合Slater函数的方法,得到了弹性散射微分截面的解析表达式,使计算大大简化,计算得到的电子和N2,CO散射的总截面和实验结果进行了比较,当入射电子的能量大于1keV时,理论值和实验值之间符合得很好  相似文献   

8.
将原子核散射理论中的光学势方法应用于正、负电子被原子散射的计算,提出了不含任意参数的光学势以及由此确定散射矩阵元的方法,计算了低能(≤50eV)正、负电子被Na散射的总截面并与实验结果进行了比较。  相似文献   

9.
1—50ev能区e—He散射总截面的绝对测量   总被引:2,自引:0,他引:2       下载免费PDF全文
李泰华  冯安平  杨勇 《物理学报》1994,43(3):380-388
文章详细地介绍了一台快脉冲电子飞行时间谱仪,在谱仪上测量了1—50eV能区的e—He散射绝对总截面(TCS),测量的精度优于5%,与其它的实验结果和理论计算值比较,在误差范围内符合得较好,文章也介绍了实验方法和误差分析。 关键词:  相似文献   

10.
将原子核散射理论中的光学势方法应用于正、负电子被原子散射的计算,提出了不含任意参数的光学势以及由此确定散射矩阵元的方法,计算了低能(≤50eV)正、负电子被Na散射的总截面并与实验结果进行了比较。  相似文献   

11.
在考虑分子内原子间的几何屏蔽效应随电子入射能量变化的基础上, 提出了一种能够在中、高能区准确计算“电子-分子”散射总截面的可加性规则修正方法. 利用这一修正后的可加性规则并使用“电子-C, H, O, N原子”散射总截面的实验数据, 在50—5000 eV内计算了电子被NO, N2O, NO2和C2H6分子散射的总截面, 且将计算结果与实验结果及其他理论结果进行了比较. 结果表明, 利用这一方法修正过的可加性规则进行计 关键词: 电子散射 可加性规则 总截面 几何屏蔽效应  相似文献   

12.
1INTRODUCTIONSimplehydrocarbonmoleculesasanimportantcomponentintheplanetaryandcometaryatmosphereandasadominantmaterialinthefi...  相似文献   

13.
在考虑分子内成键原子间的电子云重叠效应的基础上,提出了一种能够在中、高能区准确计算“电子-分子”散射总截面的修正势方法.利用可加性规则及Hartree-Fock波函数,使用这一修正过的复光学势,在30—5000eV内对电子被4个等电子(Z=18)分子(HCl,H2S,PH3和SiH4)散射的总截面进行了计算,并将理论计算值与实验结果及其他理论值进行了比较.结果表明,利用这一修正过的复光学势及可加性规则进行计算,所得理论值与实验结果更为接近. 关键词: 电子散射 总截面 可加性规则 束缚原子  相似文献   

14.
The method of relativistic optical potential is applied to studying elastic scattering of electrons by europium and ytterbium atoms in a wide range of collision energies up to 2 keV. The angular dependences of the scattering differential cross sections and the energy dependences of the scattering integral (total, elastic, momentum transfer, and viscosity) cross sections are calculated in both spin-polarized and spin-unpolarized approximations. It is shown that the spin-polarized approximation should be used to calculate the scattering cross sections at energies below 10 eV for a europium atom. The low-energy scattering of an electron by a europium atom is characterized by P-, D-, and F-wave shape resonances. For an ytterbium atom, the calculated cross sections are in good agreement with available experimental data and with those obtained by calculation in terms of the relativistic convergent close-coupling method.  相似文献   

15.
使用可加性规则,在Hartree-Fock水平上计算了30-3000eV的正电子被三个分子(O2、H2O及CH4)散射的总截面。计算正电子被三个分子散射的总截面时,首次使用了被束缚原子概念修正过的复光学势(这一复光学势考虑了分子中两个原子间的电子云重叠效应)。将正电子被这三个分子散射的总截面计算结果与实验结果及其它理论计算结果进行了比较,结果显示出在30-3000eV内,文中的计算结果与实验结果及其它理论计算结果具有较好的一致性。因此,可加性规则与修正后的复光学势相结合,完全适用于正电子被分子散射的总截面的计算。  相似文献   

16.
A fitting formula based on the Born approximation is used to fit the total cross sections for electron scattering by diatomic molecules (CO, N2, NO, O2 and HCl) in the intermediate- and high-energy range. By analyzing the fitted parameters and the total cross sections, we found that the internuclear distance of the constituent atoms plays an important role in the e-diatomic molecule collision process. Thus a new semi-empirical formula has been obtained. There is no free parameter in the formula, and the dependence of the total cross sections on the internuclear distance has been reflected clearly. The total cross sections for electron scattering by CO, N2, NO, O2 and HCl have been calculated over an incident energy range of 10–4000 eV. The results agree well with other available experimental and calculation data.  相似文献   

17.
Taking into consideration the changes of the geometric shielding effect in a molecule as the energy of incident electrons varies, this paper presents an empirical fraction, which depends on the energy of incident electrons, the target's molecular dimension and the atomic and electronic numbers in the molecule. Using this empirical fraction, it proposes a new formulation of the additivity rule. Employing the new additivity rule, it calculates the total cross sections of electron scattering by C2H4, C6H6, C6H14 and C8H18 over the energy range from 50 to 5000eV. In order to exclude the calculation deviations caused by solving the radial Schrodinger equation of electron scattering by atoms, here the atomic cross sections are derived from the experimental total cross section results of simple molecules (H2, O2, CO) via the inversion algorithm. The quantitative total cross sections are compared with those obtained by experiments and other theories, and good agreement is obtained over a wide energy range, even at energy of several tens of eV.  相似文献   

18.
A new experimental technique for the measurements of the total cross section for electron scattering from atoms and molecules at very low energy is described. Momentum transfer cross sections for scattering from Ar, Kr and Xe at very low energies were carefully derived using the modified effective range theory from the recently measured total cross sections, which were obtained with a new experimental technique utilizing the threshold photoelectron source. A significant discrepancy between the momentum cross sections derived from the present analysis and those determined in the previous electron swarm studies was found at energies below 100 meV. The findings emphasize the need of further high precision experiments in the very low energy region as well as re-analysis of the previous swarm data.  相似文献   

19.
利用可加性规则,使用Hartree-Fock 波函数,采用被束缚原子概念修正过的复光学势,首次在100~5 000eV内对电子被具有较多电子数的氟代甲烷分子散射的总截面进行了计算,且将计算值与实验值及经验公式进行了比较,得出了被束缚原子概念修正过的复光学势可成功用于"电子-氟代甲烷"散射总截面计算的结论;研究了"电子-氟代甲烷"的散射总截面与目标分子总电子数及电子入射能量间的关系,初步分析了结构因子与总电荷数相关的原因,并指出了对复光学势进行进一步修正时应遵循的原则.  相似文献   

20.
In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-160 scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.  相似文献   

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