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《原子与分子物理学报》2018,(4)
主要研究了全电离等离子体的散射相移、传输截面和电导率.相移应用WKB方法计算,且计算结果与使用精确计算方法得到的结果非常一致,证明了所用计算方法的正确性和准确性.在对传输截面的计算中,观察到了形状共振,这种共振是由于半束缚态的消失产生的.电导率的计算应用了Chapman-Enskog方法,并与其它理论和实验结果进行了比较. 相似文献
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本文研究了近理想等离子体中的电子弹性散射过程.利用Debye-Hückel模型考虑等离子体环境对电子与离子间相互作用的屏蔽效应.结合分波法计算了不同Debye长度情况下,电子与不同核电荷数离子散射的分波相移和微分散射截面.研究了散射波函数、分波相移和微分截面随等离子体屏蔽参数的变化规律.最后,基于Spitzer公式, 初步讨论了分波法计算的等离子体的电导率与卢瑟福公式计算的电导率之间的区别. 相似文献
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本文研究了近理想等离子体中的电子弹性散射过程.利用Debye-Htickel模型考虑等离子体环境对电子与离子间相互作用的屏蔽效应.结合分波法计算了不同Debye长度情况下,电子与不同核电荷数离子散射的分波相移和微分散射截面.研究了散射波函数、分波相移和微分截面随等离子体屏蔽参数的变化规律.最后,基于Spitzer公式,初步讨论了分波法计算的等离子体的电导率与卢瑟福公式计算的电导率之间的区别. 相似文献
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在双电子复合过程发生的能量范围内,发射X光子的原子过程除双电子复合过程外还有辐射复合、共振激发、共振复合以及直接激发原子过程. 本文使用相对论组态相互作用方法计算了这些过程的截面,比较了在双电子复合过程发生的能量范围内这些原子过程的截面与双电子复合过程截面,探讨了这些过程对双电子复合过程的影响. 研究结果表明,辐射复合截面随入射电子束能量的增大迅速减小,在双电子复合能量范围内几乎为一常数,可以作为本底来处理;共振激发和共振复合过程对双电子复合过程的影响可以忽略不计;当入射电子束能量高于靶离子的第一激发能时,电子碰撞直接激发截面与高Rydberg态的截面连成一片,随着入射电子束能量的增加,电子碰撞直接激发截面越来越大,这时必须考虑直接激发过程. 使用相对论组态相互作用方法计算了类氖氙离子的双电子复合截面,其结果与已有的部分实验和理论结果很吻合. 相似文献
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在双电子复合过程发生的能量范围内,发射X光子的原子过程除双电子复合过程外还有辐射复合、共振激发、共振复合以及直接激发原子过程.本文使用相对论组态相互作用方法计算了这些过程的截面,比较了在双电子复合过程发生的能量范围内这些原子过程的截面与双电子复合过程截面,探讨了这些过程对双电子复合过程的影响.研究结果表明,辐射复合截面随入射电子束能量的增大迅速减小,在双电子复合能量范围内几乎为一常数,可以作为本底来处理;共振激发和共振复合过程对双电子复合过程的影响可以忽略不计;当入射电子束能量高于靶离子的第一激发能时,电子碰撞直接激发截面与高Rydberg态的截面连成一片,随着入射电子束能量的增加,电子碰撞直接激发截面越来越大,这时必须考虑直接激发过程.使用相对论组态相互作用方法计算了类氖氙离子的双电子复合截面,其结果与已有的部分实验和理论结果很吻合. 相似文献
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Multiple-excitation cross sections for the scattering of 70.4 MeV 12C ions on the even neodymium isotopes are calculated by the method of angle-dependent phase shifts. The results are compared with the data. 相似文献
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A method for the semiclassical calculation of the total cross section in atomic and molecular elastic collisions, for the glory energy range, is reported. The parameters needed for the calculation of the glory undulatory component of the cross section are obtained from a few JWKB phase shifts for impact parameters near the glory impact parameter. The smooth component of the cross section is obtained from JB phase shifts for the long range attraction. The procedure, suitable for every potential model, is accurate and much faster than a full JWKB calculation. A discussion of some typical results is reported and an analysis of the information obtainable from experimental absolute cross sections is also given. 相似文献
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V. K. Lukyanov 《Physics of Atomic Nuclei》2006,69(6):1033-1044
Nucleus-nucleus scattering is considered in the high-energy approximation and on the basis of Glauber-Sitenko microscopic theory in the optical limit. Analytic expressions for eikonal phase shifts are given for the case of Fermi-type realistic potentials and nuclear-density distributions. The effect of taking into account the distortions of the trajectories of the nuclei involved and the nuclear-density dependence of nucleon-nucleon forces on the total reactions cross sections is illustrated. The sensitivity of the reaction cross sections to the choice of model for the 6He projectile nucleus, which involves a neutron halo, is explored. Semimicroscopic optical potentials are introduced in order to describe differential cross sections for elastic scattering. The results of the present calculations are compared with available experimental data. 相似文献
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Williamm M. Macdonald 《Nuclear Physics A》1983,395(1):221-234
A theory of optical phase shifts (OPS) developed for analyzing low-energy resonant cross sections is applied to analyze the total cross section for low-energy neutrons on n + 32S. Phase shifts of a model for the optical potential are calculated at complex energies and compared with the OPS in order to determine the depth of its real and absorptive potentials. 相似文献
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Results of calculations of nucleon-nucleon scattering phase shifts (S-, P- and D-wave) and delta-production cross sections are presented for a quark potential model with channel coupling in both generator-coordinate and resonating-group formalisms. The dependence of the results on various input assumptions is shown. The interpretation in terms of a local potential is discussed, as are the extensions to the calculation necessary for agreement with experiment. 相似文献
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Relative differential cross sections of neutrons elastically scattered from 4He were measured at neutron energies of 0.55, 0.84, 1.16 and 1.33 MeV. The scattered neutrons were detected in a time-of-flight spectrometer for c.m. angles ranging from 25° to 161°. The relative differential cross sections are compared to curves generated from phase shifts published elsewhere. 相似文献
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F. Binon P. Duteil M. Gouanére L. Hugon J. Jansen J.-P. Lagnaux H. Palevsky J.-P. Peigneux M. Spighel J.-P. Stroot 《Nuclear Physics A》1978,298(3):499-529
Differential cross sections for negative pion scattering on 4He have been measured at five pion kinetic energies between 110 and 260 MeV in the angular range from 5° to 180°. Total cross sections have also been measured at eleven energies between 67 and 285 MeV. The differential cross sections have been fitted with a phenomenological expression for the nuclear scattering amplitude. Conventional phase shifts have been reconstructed starting from the parameters of the fits. 相似文献
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P.A.M. Guichon 《Nuclear Physics A》1983,402(3):541-554
Forward (p, n) reaction cross sections are expressed in terms of nucleon-nucleon phase shifts. The ratio of the probabilities for triggering Gamow-Teller or Fermi transitions is found to be in quite good agreement with experiment. New np scattering experiments are also suggested in order to improve the interpretation of (p, n) reactions. 相似文献