Triple Differential Cross Sections for the Simultaneous Ionization and Excitation of He by Electron and Positron Impact.

Autor: Haque, A., Mistry, T., Jana, D., Mandal, B., Mondal, M., Purkait, M.
Zdroj: International Journal of Theoretical Physics; Apr2024, Vol. 63 Issue 4, p1-13, 13p
Abstrakt: Four-body formalism of the three-Coulomb wave (3CW-4B) model has been employed to investigate the simultaneous ionization and excitation of He by the impact of fast electron and positron. In this method, the incident wave is described by a plane wave, and the final state wavefunction is a product of the three-Coulomb wave due to the correlated motion of the three unbound charged particles. The triple differential cross sections (TDCS) are calculated and analysed for both the asymmetric coplanar and perpendicular geometries for the incident energies of 0.57, 1.5, and 5.5 keV at several electron emission energies. The distinguishing features have been noted in the angular distribution of the ejected electron. A significant difference in the TDCS structure, especially in the region of binary and recoil peak is found by choosing two different forms of bound state wave function of He in its ground state. The results of the 3CW-4B model are compared to the available experimental and theoretical findings. We find a very good agreement between the present result and the experimental data for pure single ionization, whereas some disagreement has been found in the process of simultaneous ionization with excitation to the n=2 state of H e + . Finally, by changing the sign of the projectile’s charge, significant differences have been observed between the two sets of results for electron and positron impact. [ABSTRACT FROM AUTHOR]
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