共查询到20条相似文献,搜索用时 62 毫秒
1.
本用自旋平均静态交换势三体扭曲波波恩近似(DWBA)计算了Li^ (1s^2)和He(1s^2)、K^ (3p^6)和Ar(3p^6)在1000eV入射能下的共面不对称(e,2e)三重微分截面(TDCS)。通过比较离子和原子靶三重微分截面的角分布,表明两体碰撞图像在离子靶的情形不成立。 相似文献
2.
本文用自旋平均静态交换势三体扭曲波波恩近似(DWBA)计算了Li+(1s2)和He(1s2)、K+(3p6) 和Ar(3p6)在1?000?eV入射能下的共面不对称(e, 2e)三重微分截面(TDCS).通过比较离子和原子靶三重微分截面的角分布,表明两体碰撞图像在离子靶的情形不成立. 相似文献
3.
4.
对208Pb的低激发态分立能级属性和相关平均振幅或形变参数进行了系统研究,利用扭曲波波恩近似方法系统计算了12个分立能级的中子直接非弹性散射截面. The amplitudes or form factors of the low discrete levels of 208 Pb are investigated systematically, the neutron direct inelastic scattering cross sections from 12 levels on 208 Pb are calculated. 相似文献
5.
采用扭曲波玻恩近似理论计算了共面对称几何条件下类Ne离子2p轨道电子在不同出射电子能量下的(e,2e)反应三重微分截面,出射电子能量分别为3,5,7.5,10,15,20,30和50 eV.计算结果表明,随着出射电子能量的增大和核电荷数Z的增大,三重微分截面的幅度逐渐减小.除Ne以外,对其他离子,在出射电子角度为150?附近出现了一个新的结构,对比不同出射电子能量时的(e,2e)反应三重微分截面,发现这个结构的幅度随着出射电子的能量先增大后减小,文中用一种两次两体碰撞过程对这些现象进行了解释. 相似文献
6.
Xe(4d~(10))(e,2e)反应三重微分截面的理论研究 总被引:1,自引:1,他引:0
采用修正后的扭曲波玻恩近似理论,计算了共面不对称几何条件下Xe(4d~(10))(e,2e)反应的三重微分截面.散射电子能量为1000 eV,敲出电子能量为20 eV,散射电子角度分别固定在2°,4°和7.5°.理论计算与Avaldi等人的实验结果和扭曲波玻恩近似理论计算进行了比较,发现出射电子之间的后碰撞相互作用较弱,极化效应在反应过程中起着重要作用. 相似文献
7.
采用修正后的扭曲波玻恩近似理论,计算了共面不对称几何条件下Xe(4d10)(e, 2e)反应的三重微分截面。散射电子能量为1000eV,敲出电子能量为20eV,散射电子角度分别固定在2o,4o和7.5o。理论计算与Avaldi等人的实验结果和扭曲波玻恩近似理论计算进行了比较,发现出射电子之间的后碰撞相互作用较弱,极化效应在反应过程中起着重要作用。 相似文献
8.
9.
利用扭曲波波恩近似方法及AUTOSTRUCTURE (AS)程序,快速精确地计算了类氖Ar8+离子2s22p6、2s22p53s、2s22p53p、2s22p53d、2s2p63s、2s2p63p和2s2p63d组态的能级以及当电子碰撞能量为75.0、125.0、175.0、250.0 (Ry)时,从j能态到i能态的碰撞强度.并且与已有的研究成果进行了对比.结果表明,采用扭曲波波恩近似并结合AUTOSTRUCTURE (AS)程序的研究方法,可以成为研究原子或离子碰撞强度的有效途径。 相似文献
10.
利用扭曲波波恩近似方法及AUTOSTRUCTURE(AS)程序,快速精确地计算了类氖Ar8+离子2s22p6、2s22p53s、2s22p53p、2s22p53d、2s2p63s、2s2p63p和2s2p63d组态的能级以及当电子碰撞能量为75.0、125.0、175.0、250.0(Ry)时,从j能态到i能态的碰撞强度.并且与已有的研究成果进行了对比.结果表明,采用扭曲波波恩近似并结合AUTOSTRUCTURE(AS)程序的研究方法,可以成为研究原子或离子碰撞强度的有效途径. 相似文献
11.
中低能入射电子与氦离子碰撞的(e,2e)反应三重微分截面 总被引:1,自引:1,他引:0
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),并考虑了入射道的库仑相互作用及出射电子的交换对称性,计算了在共面-等能分享-固定相对角度几何情况下,入射能量分别为:58.4、68、81.6、108.8和174.4eV的He+(e,2e)反应三重微分截面.结果表明,在较低碰撞能量散射中,入射道库仑场对两体碰撞起主要作用. A corrrelated three body continuum wavefunction proposed by Brauner et al has been recently modified further to allow for three body effects by introducing Somerfeld parameters (Berakdar and Briggs). The triple differential cross sections for electron impact ionization of He+ in coplanar equal energy sharing and fixed relative angle geometry are calculated. The initial channel wavefunction involves a Coulomb wavefunction due to the long range Coulomb attraction between the incident... 相似文献
12.
13.
利用修正的BBK理论,考虑入射道的库仑相互作用及出射道电子的交换对称性,在共面-等能分享-垂直角度碰撞几何中,计算了能量分别为85.6、105.6、227.6和375.6eV的入射电子碰撞Li+(ls)电离的三重微分截面.讨论了干涉效应、关联效应及入射道库仑场对截面的影响.Based on revised BBK theory, triple differential cross sections (TDCS) have been calculated for ionization of Li + (ls) by electron impact. A coplaner, equal energy, fixed re1ative angle kinematics are chosen and the particular case where the scattered and ionized electrons emerge perpendicular to each other is emphasized. The incoming electron state is considered by a Coulomb wave from the long range... 相似文献
14.
We report the observation of the zero-phonon structure of the 0.9 eV absorption in GaAs: Cr, which correspond to intracenter Cr2+ transition. This result and the existence of the stable Cr2+ state in our n-type GaAs: Cr samples, allow to consider that Cr2+ is the dominant chromium state in these crystals. 相似文献
15.
16.
17.
The differntial elastic scattering cross sections of Zr for 14.2MeV neutrons are measured by the associated particle time-flight method at angles from 10° to 140°.The corrections for neutron flux attenuation,multiple scattering and finite geometry are performed by using Monte-Carlo method.The experimental results are compared with the available lata from other work and the theoretical calculation. 相似文献
18.
Physics of Atomic Nuclei - Differential cross sections for elastic scattering of hydrogen-isotope nuclei are used in simulations of facilities where fusion reactions are initiated and in... 相似文献
19.
The differential and integral cross sections for electron impact excitation of lithium from the ground state 1s22s to excited states 1s22p, 1s23l (l=s, p, d) and 1s24l (l=s, p, d, f)at incident energies ranging from 5 eV to 25 eV are calculated by using a full relativistic distorted wave method. The target state wavefunctions are calculated by using the Grasp92 code. The continuum orbitals are computed in the distorted-wave approximation, in which the direct and exchange potentials among all the electrons are included. A part of the cross sections are compared with the available experimental data and with the previous theoretical values. It is found that, for the integral cross sections, the present calculations are in good agreement with the time-independent distorted wave method calculation, for differential cross sections, our results agree with the experimental data very well. 相似文献
20.
在中高能质子诱发散裂反应相关核工程设计中,可靠的蒙特卡罗模拟程序结合核反应理论模型具有较好的理论指导意义。本工作中,利用GEANT4耦合INCL4和ABLA理论模型以及FLUKA耦合PEANUT模型模拟计算了几百MeV至几个GeV质子轰击Be,Al,Fe,W,U等靶后30°,60°,120°,150°出射角产生的散裂中子双微分截面,并与现有实验数据进行了比较。结果发现,FLUKA和GEANT4模拟计算较好地再现了Al,Fe,W,U等靶实验测量数据。然而,模拟结果明显低估了Be靶出射中子能量小于10 MeV能区的实验数据。For the design of nuclear engineering related with medium-high energy proton induced spallation reaction,the reliable Monte Carlo simulation codes coupled with nuclear reaction models have a good theoretical guidance.In this work,the production spallation neutron double differential cross sections at 30°,60°,120°,150°emission angle for Be,Al,Fe,W,U target materials at incident proton energies between several hundred MeV and GeV are theoretically calculated by using the GEANT4 coupled INCL4 and ABLA,and the FLUKA coupled PEANUT.The calculated results were compared with the available experimental data.It is found that the GEANT4 and FLUKA calculations well reproduced the experimental measurement of Al,Fe,W,U target materials.However,calculations obviously underestimated the emission neutrons of Be target for lower than 10 MeV energy range. 相似文献