正电子冲击下氦电离三重微分截面的理论计算

我们发展了一种正电子碰撞原子电离的畸变波Born近似方法, 在这个方法中,正负电子偶素通道通过一个ab initio的光学势附加到入射粒子和靶的相互作用势上,且通道对电离作用被第一次被考虑在正电子碰撞原子电离的过程中. 应用这个方法计算了在50 eV入射能量范围氦的电离的三重微分截面,计算结果和实验数据很好的符合.     

Total cross sections scattering at of positron-sodium low energies

A new calculation for the total cross section of positron-sodium scattering is performed in an energy range down to a few tenths of one electron volt using the coupled-channel optical method.The ionization continuum and the positronium formation channels are included via an equivalent-local complex potential.The role played by the break-up and rearrangement processes in the low energy positron-sodium scattering is also investigated.The total scattering cross section is reported and compared with the available theoretical and experimental data.     

Coupled-channels optical calculation of positronben hydrogen resonances

An application of the coupled-channels optical method is given for the energy-dependent phenomena of positron-hydrogen resonances below the n=2 excitation threshold. The equivalent local optical potential is used to account for the target polarization and positronium formation. The calculation includes 9 explicitly physical coupled channels. The lowest S-wave resonance energy position and new resonances are found. Angular dependence of the cross section in the resonance region are investigated.     

Coupled-channel optical calculation for positron—lithium scattering

Positron scattering with atomic lithium is investigated by using a coupled-channel optical method.The ionization continuum and positronium formation channels are taken into account via a complex equivalent-local optical potential.The positronium formation cross sections and the ionization cross sections,as well as the total scattering cross sections,are reported at energies above 3 eV and compared with available experimental and theoretical data.     

Resonant Auger Scattering by Attosecond X-Ray Pulses

As x-ray probe pulses approach the subfemtosecond range, conventional x-ray photoelectron spectroscopy(XPS) is expected to experience a reduction in spectral resolution due to the effects of the pulse broadening.However, in the case of resonant x-ray photoemission, also known as resonant Auger scattering(RAS), the spectroscopic technique maintains spectral resolution when an x-ray pulse is precisely tuned to a core-excited state. We present theoretical simulations of XPS and RAS spectra on a sho...     

Coupled-Channels Optical Calculation for Electron Scattering from Metastable Helium

Coupled-channels optical calculations for total and resonance excitation integral cross sections for electron scattering on the metastable level 2^1,3S of helium are presented. The results are in agreement with other theoretical and experimental data.     

Elastic and inelastic positron-helium scattering

Elastic and inelastic positron--helium scatterings have been investigated with the coupled-channel optical method (CCO). Ionization continuum and positronium formation channels are included via a complex equivalent-local optical potential. Calculations are reported of cross sections of elastic scattering, total excitation and n=2, 3, and 4 excitations of ground-state helium for incident energies from 30~eV to 400~eV. The present calculation shows that the ionization and Ps-formation channels significantly affect the cross sections of elastic and inelastic positron--helium scatterings.     

Resonance phenomena and threshold features in positron—helium scattering

Investigations of resonances and threshold behaviors in positron-helium scattering have been made using the momentum-space coupled-channels optical method.The positronium formation channels are considered via an equivalent-local complex potential.The s-wave resonances and the Wigner cusp feature at the positronium(n = 1) formation threshold are compared with the previous reports.The p-and the d-wave resonances and a Wigner cusp feature at the positronium(n = 2) formation threshold are reported for the first time.     

Total cross sections of positronben sodium scattering at low energies

A new calculation for the total cross section of positron-sodium scattering is performed in an energy range down to a few tenths of one electron volt using the coupled-channel optical method. The ionization continuum and the positronium formation channels are included via an equivalent-local complex potential. The role played by the break-up and rearrangement processes in the low energy positron-sodium scattering is also investigated. The total scattering cross section is reported and compared with the available theoretical and experimental data.     

Coupled-channels optical calculation of positron-hydrogen resonances

An application of the coupled-channels optical method is given for the energy-dependent phenomena of positron-hydrogen resonances below the n=2 excitation threshold.The equivalent local optical potential is used to account for the target polarization and positronium formation.The calculation includes 9 explicitly physical coupled channels.The lowest S-wave resonance energy position and new resonances are found.Angular dependence of the cross section in the resonance region are investigated.