共查询到19条相似文献,搜索用时 78 毫秒
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用密耦近似方法计算了同位素He原子与NO分子碰撞体系的总微分截面、弹性微分截面和非弹性微分截面,总结了同位素He原子对He-NO碰撞体系微分截面的影响. 计算结果表明:在同一入射能量下,随着入射同位素He原子质量增加,总微分截面在0°时的角分布逐渐增大;同位素He原子与NO分子碰撞发生的彩虹现象越明显. 同时,体系约化质量增加的效应大于相对碰撞速度减小的效应,使散射振荡间隔逐渐减小.
关键词:
He-NO
密耦近似
微分截面
同位素效应 相似文献
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基于作者构造的He-HBr体系的各向异性势,采用密耦方法计算了3He,4He,6He和7He与HBr分子在碰撞能量分别为40和75meV时的微分截面,详细讨论了入射氦同位素对微分截面的影响.结果表明:在相同碰撞能量时,随着同位素氦原子质量的增加,总微分截面在0° 时的角分布逐渐增大,同一级衍射振荡极小值位置逐渐向小散射角方向移动;弹性与总非弹性截面交界角逐渐减小,总非弹性截面逐渐增加.碰撞能量越低,入射同位素He原子的
关键词:
同位素效应
微分截面
各向异性势
He-HBr体系 相似文献
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Ne-HCl相互作用势及微分散射截面的研究 总被引:1,自引:0,他引:1
使用Huxley解析势能函数拟合在CCSD(T)/aug-cc-pV5Z-33211理论水平下精确计算的相互作用能数据,得到了Ne-HCl复合物的相互作用势.在此基础上,我们首次完成了入射能量分别为40,60,75和100 meV时,Ne-HCl碰撞微分散射截面的密耦计算,并获得了总微分截面、弹性微分截面和转动激发微分截面随散射角变化的趋势.我们希望计算结果能对Ne-HCl散射的实验和理论研究提供参考信息. 相似文献
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低能氖原子与H2(D2、T2)分子碰撞微分截面的研究 总被引:6,自引:0,他引:6
用密耦方法及Tang-Toennies势模型计算了Ne-H2(D2、T2)碰撞体系的转动激发碰撞截面,得到了H2分子的对称同位素替代情形下Ne-H2(D2、T2)三碰撞体系总截面及微分截面的变化规律. 相似文献
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首先用Huxley势函数形式拟合了在RCCSD(T)/aug-cc-pVTZ+bf理论水平下计算的He-NO相互作用能数据,获得了He原子与NO分子相互作用的各向异性势,然后采用密耦近似方法计算了He-NO碰撞体系的总微分截面、弹性微分截面和非弹性微分截面,并总结了微分散射截面的变化规律. 结果表明,拟合势不但表达形式简洁,而且较好地描述了He-NO系统相互作用的各向异性特征;利用碰撞体系分子间势的量子化学从头计算结果,可解决势能参数难以确定的问题,对进一步研究原子与分子碰撞机理有一定参考价值.
关键词:
各向异性势
势能参数
密耦近似
微分截面 相似文献
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运用费曼微扰方法分别计算了在磁偶极场、电偶极场和均匀静电场及静磁场中光子转化成轴子的非极化微分截面.在电偶极场中,沿光子传播方向及其反方向上的非极化微分截面为零;而在磁偶极场中,在上述方向上通常则具有非零的微分截面,但当光子传播方向平行于磁场偶极距矢量时,该微分截面为零.在均匀的静磁场和均匀静电场中,只有在光子传播方向及其反方向上具有非零的微分截面,但后者小于前者.在轴子质量趋于零的极限条件下,上述过程和光子转化为引力子的过程表现出某些非常类似的性质.
关键词:
轴子
光子
微分截面 相似文献
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The differential elastic neutron scattering cross sections of141Pr were measured at the incident neutron energies of 1.2, 1.7 and 1.9 MeV in the angular range between 25 and 150 degrees. At 1.7 MeV the differential inelastic neutron scattering cross sections corresponding toQ=?1122 keV, and at 1.9 MeV the ones corresponding toQ=?1122, andQ=?1295 keV were also determined. In a transmission experiment, the total cross section was measured between 0.50 and 2.42 MeV. The total and differential cross sections were calculated using the nuclear optical model. The calculated results were compared with the experimental data. 相似文献
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NEUTRON PHYSICS GROUP OF NUCLEAR PHYSICS LABORATORY 《中国物理C(英文版)》1978,2(5):450-460
Using time of flight technique the elastic differential cross sections were measured for neutrons from natural Fe, Cu, and Pb in the energy range 1.10 to 1.40 MeV.The effect of neutron attenuation and multiple scattering in the sample is corrected by extrapolation of the experimental results. The correction of scattering angles due to the finite source-sample-detector geometry is also considered. The measured elastic differential cross sections are expressed by Legendre polynomial expansions, from which the total cross sections are obtained.The Optical-Model Calculations are carried out which show a reasonable consistency with the measured values. 相似文献
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E. G. Sheikin 《Technical Physics》2010,55(1):1-9
A new model differential cross section is proposed for describing elastic scattering of electrons in simulating the passage
of electrons through a substance by the Monte Carlo method. This differential cross section correctly describes the first
and second transport scattering cross sections, but is characterized by the total elastic scattering cross section much smaller
than the actual value of the total elastic scattering cross section. The application of this differential cross section makes
it possible to considerably reduce the number of elastic collisions in the Monte Carlo simulation of passage of electrons
in a substance and to model the passage of high-energy electrons using the individual collision model. 相似文献
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ZHANG Rong YANG Yong-Xu LU Xiao LI Qing-Run 《理论物理通讯》2007,47(4):711-714
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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Technical Physics - We have measured the absolute values of total cross sections of capture of one and two electrons by He2+ ions from argon atoms. The differential scattering cross sections have... 相似文献
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This paper describes methods that have been developed for the accurate measurement of total and differential bulk acoustic scattering cross sections. Analysis is made of the sources of uncertainty entailed in measurements of this kind and a complete derivation is developed for the angular variation of the interrogated scattering volume. Experimentally determined values of differential scattering cross sections are reported for specimens of skeletal muscle, blood, liver, and secondary tumors arising in liver, obtained in the frequency range 4-7 MHz for scattering angles in the practically attainable range 60 degrees-150 degrees and also at 180 degrees (backscatter). A basis for extrapolating these results to other scattering angles can be derived from a combination of theoretical and experimental considerations, as presented in a companion paper [J. Acoust. Soc. Am. 79, 2048-2054 (1986)]. Based on such extrapolation, values for total scattering cross sections are estimated for the above tissues, the values are compared with determinations by different techniques as reported by other authors, and corresponding estimates are derived for the contribution of scattering processes to total attenuation in the tissues. 相似文献
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Yu. I. Romanov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(6):793-796
The possibility of detecting the anomalous neutrino magnetic moment from comparison of the “electromagnetic” and “electroweak” contributions to the differential and total cross sections of neutrino-electron scattering is considered. The results of quantitative analysis and a graphical image of the cross sections are presented for the case of scattering of beryllium solar neutrinos by an electronic target. 相似文献
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He-N_2势能表面对散射截面的影响 总被引:8,自引:5,他引:8
从总散射截面、微分散射截面和分波散射截面三方面对He-N2体系的三个势能表面进行了详细比较。计算中采用了精确度较高的密耦(Close-Coupling)近似方法(E=64meV),计算结果与MKeil等的实验结果基本相符。研究结果表明:势能球平均零点能位置、势阱深度、排斥势的强度以及势能在势阱附近的方向性都对散射截面有较大的影响,为根据散射截面准确地确定He-N2体系的相互作用势能参数提供了一种新依据。 相似文献
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根据中子与天然Zr及其同位素反应的总截面,去弹截面和弹性散射角分布的实验数据,得到一组普适的光学模型势参数;应用得到的光学模型势参数,光学模型,Hauser-Feshbach理论,预平衡反应的激子模型和扭曲波玻恩近似理论,系统计算和分析了中子与90,91,92,94Zr反应的非弹散射角分布和双微分截面,理论结果与实验很好的一致. 相似文献