Theoretical Analysis Of Ne Atom (e,2e) Processes In The Coplanar Double-symmetric Geometry And Post Collision Interaction Influences

Electron impact single ionization process (also known as (e,2e) process) on atoms and molecules is of great importance in physics. The theoretical investigations of (e,2e) processes on atoms and molecules provide a platform to obtain relevant knowledge of collision dynamics and the characteristic structure of targets by studying the triple differential cross sections (TDCS). Relevant data of TDCS are also needed in astrophysics, controlled nuclear fusion, plasma physics and others. In different geometrical arrangements,(e,2e) processes have been studied extensively on simple targets such as H and He, and there are a good agreement between theoretical predictions and experimental data. By using new experimental techniques, the experiments toward to investigate the (e,2e) processes on multi-electron atoms or molecules. For complex multi-electron atomic targets (not including molecular targets), the agreements between experimental data and theoretical predictions are unsatisfactory, which is a challenge to many excellent theories It has been the main task for theorists that improving the old theories or developing some new theories to explain the multi-electron atoms or molecules (e,2e) processes. Ne is a multi-electron atom, which is just between the "simple" He atom and the "complex" Ar atom. Ne can be considered as a simpler model of Ar atom. Therefore the (e,2e) researching of Ne will be valuable to the study of more complex atoms and molecules.According to the prophase investigation, the theoretical studies of electron impact ionization of Ne atom were mainly focused on the case of large energy transfer. Recently, the experimental workers reported some (e,2e) experimental data of Ne (2p) impacted by electron of different energies in the coplanar double-symmetric geometry, which would be helpful to the understanding of Ne atom.In this thesis, we studied the (e,2e) processes of Ne atom in the coplanar double-symmetric geometry. In the frame of standard first-order distorted wave Born approximation (DWBA), the TDCS of (e,2e) processes were calculated in the coplanar double-symmetric geometry for many different energies of incident electron, and the calculations were compared with the latest experimental data. It is found that when the incident electron energies are very low, the theoretical calculations are in poor agreement with the experimental data, and as the incident electron energies increased, the degree of agreement is improved. Then the post collision interaction (PCI) is employed, by which there is a certain improvement in the near threshold and low energies range; although some differences between experimental data and calculations are still exist, the model including PCI is in better agreement with the experiment, especially the forward scattering peak structure. Finally, by changing the atomic potential of Ne, some new calculations are performed, and the results are compared with the standard DWBA and the experimental data; except a poor agreement in the near threshold regime, good agreement of theory and experiment are found in a wild energy-range, where the central peak structure is also predicted successfully.There are six chapters in this thesis. Chapter one includes an introduction, the origin of (e,2e) experiments, and the progress in researching, ended by an overview of the whole thesis. Chapter two introduces the fundamental of (e,2e) processes (the experiment geometries, the differential cross sections and main collision mechanisms) and some successful theoretical models Chapter three mainly includes the framework of the first-order DWBA, and a related calculations of Ne (2p) atom (e,2e) processes for different incident electron energies (from near threshold to the intermediate energies) in the coplanar double-symmetric geometry, with a comparison with the experimental data. Chapter four modifies the first-order DWBA used in chapter three by including the post collision interaction which is characterized by Gamow factor; and the agreement is remarkably improved. In chapter five, we assume the incident electron potential is the Ne3p or4p atomic potential, and the new theoretical results are compared with the experimental data. In chapter six, the work of this thesis is summarized, with a preview of development trend of the (e,2e) processes experiments and theory. We hoped the related work of this thesis would provide some valuable information to the other researchers.