共查询到17条相似文献,搜索用时 125 毫秒
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基于处理裸核离子与中性原子碰撞电离过程的OBKN和ECPSSR理论模型,系统计算了不同裸核离子与中性原子碰撞K壳层电子俘获截面和直接电离截面,并与其它文献已有的理论和实验结果进行了比较.研究结果表明:碰撞能量较低时,电子俘获截面大于直接电离截面,随着碰撞能量的增加,电子俘获截面和直接电离截面均是先增大后减小且直接电离截面减小地非常缓慢,高能时,直接电离截面大于电子俘获截面.当入射炮弹离子速度接近0.67倍靶原子K壳层电子速度时,电子俘获截面达到最大值,而当入射炮弹离子速度接近靶原子K壳层电子速度时,直接电离截面达到最大值. 相似文献
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基于处理裸核离子与中性原子碰撞电离过程的OBKN和ECPSSR理论模型,系统计算了不同裸核离子与中性原子碰撞K壳层电子俘获截面和直接电离截面,并与其它文献已有的理论和实验结果进行了比较.研究结果表明:碰撞能量较低时,电子俘获截面大于直接电离截面,随着碰撞能量的增加,电子俘获截面和直接电离截面均是先增大后减小且直接电离截面减小地非常缓慢,高能时,直接电离截面大于电子俘获截面.当入射炮弹离子速度接近0.67倍靶原子K壳层电子速度时,电子俘获截面达到最大值,而当入射炮弹离子速度接近靶原子K壳层电子速度时,直接电离截面达到最大值. 相似文献
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核衰变产生的X射线和俄歇电子数据计算 总被引:1,自引:0,他引:1
核衰变过程中,内转换电子发射和电子俘获能在原子电子壳层内留下空穴.其他原子电子壳层的电子将填补这些空穴,其原子电子位置将重排,并发射X射线和俄歇电子.X射线和俄歇电子的能量由原子电子结合能计算得到,X射线和俄歇电子的强度分别由内转换电子发射和电子俘获在原子电子壳层内留下的空穴数,X射线荧光产额,和空穴转移系数计算得到.本文简要介绍核衰变产生的X射线和俄歇电子数据的计算方法、计算程序与工作流程,并以核衰变为例说明其具体应用和简要讨论与总结. 相似文献
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本文提出了一种计算多电荷离子与原子碰撞中K壳层电子俘获截面的新方法,称为模型势Oppenheimer-Brinkman-Krammer近似(MPOBK)。在该方法中我们用模型势来描述K电子所处的有效场,同时在波函数中考虑屏蔽效应。我们得到的K壳层总俘获截面是一个表解析达式。对H~ 、He~(2 )-Ne,H~ 、He~(2 )-C及O~(5 ,6 )-Ar体系的计算表明本文结果较好地与实验数据一致。 相似文献
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应用双中心原子轨道强耦合方法研究He2+-H-碰撞的单次电荷转移过程.计算中,对入射粒子He2+,包含n=1~7的所有束缚态,计算的能量本征值与NIST标准数据在百分之几的精度内符合很好;对靶H-,包括一个束缚态1s和五个连续态ns(n=2~6),束缚态能量与他人理论结果一致.在4~400 keV的入射粒子能量范围,计算单电子俘获过程的总截面及到各个壳层上的态选择截面.发现在较低的入射粒子能量,电子主要俘获到He+离子主量子数n=3~5的壳层,高能区俘获到n=2的壳层为主;对同一主量子数n,在低能区俘获到高角动量态(l=n-1,n-2)的电荷转移截面相对较大,在高能区主要俘获到l=1的p壳层.同时还计算入射粒子能量分别为4 keV和400 keV时,电子俘获到激发态辐射退激发产生的电荷转移发射光谱,并发现cascade效应的影响很大. 相似文献
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利用基于多组态Dirac-Fock方法的程序包GRASP92和RATIP以及最新发展的RERR06程序,详细计算了高离化态金离子(类镍Au51+、类铜Au50+和类锌Au49+)俘获一个自由电子到nl(n=4—8,l=0—3)壳层的辐射复合谱以及相应的辐射退激发谱.理论计算的辐射复合谱很好地重现了实验谱.研究结果表明:对类镍Au51+、类铜Au50+和类锌Au49+而言,将一个自由电子俘获到n=4壳层的概率最大;在辐射复合过程之后,处在n=4壳层的俘获电子的辐射退激发谱线最强,并且体现了整个辐射退激发谱的主要特征. 相似文献
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The absolute differential cross sections of scattering of hydrogen atoms resulting from an electron capture and an electron capture ionization are measured for collisions of 4.5- and 11-keV protons with argon and xenon atoms. The range of scattering angles is 0°–2°. From the scattering differential cross section found experimentally, the probabilities of single-electron capture and electron capture ionization as a function of the impact parameter are calculated. The dependences of the incident particle scattering angle on the impact parameter (deviation function) for interactions with Ar and Xe atoms are calculated in terms of classical mechanics using the Moliére—Yukawa potential to describe the interaction of atomic particles. Analysis is given to the probabilities of electron capture and electron capture ionization versus the impact parameter and to the distribution of the electron density on different electron shells in a target atom versus a distance to the core. It is concluded that only electrons from the outer shell of the target atom are involved in the process of electron capture ionization. The cross section of electron capture ionization is calculated in the proton energy range 5–20 keV. 相似文献
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Effects of an ultra-strong magnetic field on electron capture rates for 55Co are analyzed in the nuclear shell model and under the Landau energy levels quantized approximation in the ultra-strong magnetic field, and the electron capture rates on 10 abundant iron group nuclei at the surface of a magnetar are given. The results show that electron capture rates on 55Co are increased greatly in the ultra-strong magnetic field, by about 3 orders of magnitude generally. These conclusions play an important role in future study of the evolution of magnetars. 相似文献
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The cross section for inelastic backward electron scattering on 1p shell nuclei at incident energy Ee = 70 MeV is calculated in the shell model. Comparison is made with radiative pion capture and muon capture. It is shown that the T> branch of the M2 resonance in (e, e') and the main maxima in the (π?, γ) response function are formed by identical partial transitions. We consider the basic features of the M2 resonance excitation in 1p shell nuclei and predict configurational and isospin splitting of this mode. 相似文献
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利用冷靶反冲离子动量谱仪装置系统研究了20—40 keV He2+-He碰撞体系的态选择单电子俘获过程,实验获得了单电子俘获过程的态选择截面以及角微分截面.在所研究的能区范围,电子俘获到L壳层的截面最大,为主要的反应道,这与分子库仑过垒模型的反应窗理论的预测一致.实验测量的态选择截面与原子轨道紧耦合的计算结果很好地符合,与光谱方法的测量结果存在一定的差别,主要原因是光谱方法不能测量完整的反应通道信息.实验结果表明,总角微分截面在小角度范围主要来源于电子俘获到基态的贡献,在大角度范围主要来自电子俘获到激发态的贡献;电子俘获到基态的和激发态的角微分截面均出现振荡结构,这种振荡来源于电子俘获反应中分子轨道之间的相干效应.实验测量的角微分截面与其他实验和紧耦合方法的计算结果进行了比较和分析.
关键词:
冷靶反冲离子动量谱仪
态选择电子俘获
态选择截面
角微分截面 相似文献
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V. V. Kashkovskii 《Russian Physics Journal》2006,49(12):1301-1313
The mechanism of electron capture into acceleration that takes into account the electret properties of the accelerating chamber
shell is described. The electron capture into acceleration is a self-consistent problem. It is demonstrated that the electron
capture into acceleration is caused by the interaction of the injected electrons with the electric field of the charge created
on the side interior wall of the chamber by electrons dropped out of the acceleration. The spectrum of the captured electrons
is not normal. A large number of low-energy electrons are presented in the spectrum. Two and more peaks previously unknown
are revealed in the dependence of the captured charge on the injected charge for large values of the injected charge. The
results obtained are in agreement with the data of previous experimental studies. The captured charge and the dose rate of
bremsstrahlung from a target correspond to their actual values for betatrons with accelerated electron energies of 6 and 10
MeV. Results of simulation can be used to design accelerating chambers and electron injection systems of betatrons and other
cyclic accelerators.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 35–45, December, 2006. 相似文献
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D. H. Jakubaßa-Amundsen 《Zeitschrift für Physik A Hadrons and Nuclei》1984,316(2):161-167
Within the semiclassical strong potential Born approximation (SPB) we have calculated the electron capture from theK andL shell of a heavy target atom by protons using two different peaking approximations. Both total capture cross sections and impact parameter distributions are compared with the impulse approximation (IA) and in the case of transfer from the ArK-shell also with an exact evaluation of the SPB and with experimental data. While for theK shell, all theories give a similar impact-parameter dependence, there is a substantial difference between IA and SPB results for the 2s subshell. 相似文献