The Development Of (E,2e+Ion) Spectrometer And The Studies Of Collision Dynamics Of Charged Particles With Atoms And Molecules

The collision dynamics of atoms and molecules by electron and middle energy ion have been studied in this thesis. The thesis consists of two parts:electron collisions and ion collisions.In the part of electron collisions, we designed a fast electron (e,2e+ion) co-incidence spectrometer based on the high energy resolution electron momentum spectrometer in our laboratory. In the design, an ion imaging system is added to the spectrometer and the performance of the imaging system has been tested. A new data acquisition system is developed for the (e,2e+ion) spectrometer. The spectrometer can thus work in (e,2e),(e, ion)(e, e+ion) or (e,2e+ion) mode for electron momentum spectroscopy, molecular excitation/ionizatiion-dissociation or Coulomb explosion studies. In the part of ion collisions, we carried out an ex-periment of250keV H2+collision with He target using the Reaction Microscopes. The process of mutual ionization of projectile and target are studied in detail. In the experiment, almost all of the final state particles are measured in coincidence. The three dimensional momentum vectors of the two continuum electrons and the recoil ions are reconstructed. The momentum correlation of the final particles is investigated and the molecular orientation effect is also studied.The electron momentum spectroscopy of1-iodopropane is studied using elec-tron momentum spectrometer.There are nine chapters in this thesis. The details of each chapter are de-scribed as following:Chapter1introduces the recent progresses of the electron collision dynamics as well as the ion collision dynamics.In chapter2, the experimental techniques used in this thesis for electron momentum spectrometer and Reaction Microscopes are summarized. These tech- niques include electron and ion imaging, diffusion of molecular beam, supersonic gas jet, position sensitive detector, the method to perform charge digitization and high resolution time measurements.Chapter3provides a brief introduction of the theory of electron momentum spectroscopy and an overview of the development of (e,2e) experimental setup. We also summarize the (e.2e+ion) measurement carried out in recent years. The scientific aims of our new designed (e,2e+ion) spectrometer and its relation with electron momentum spectroscopy is clarified.In chapter4, the design of (e,2e+ion) spectrometer based on the high energy resolution electron momentum spectrometer in our laboratory is introduced. In this chapter we describe the overall working principle of the new setup. We develop a new multi-coincidence measurement system for the new apparatus and a data acquisition system based on the PXI bus.The initial commissioning process of the (e,2e+ion) spectrometer is made in chapter5. We choose the electron impact ionization of Ar and the Coulomb explosion of CO2to testify the performance of the momentum imaging system. A off-line data analyzing software is developed based on the GO4package.The collision dynamics of ion collision and the associated kinematics are described in chapter6.The mutual projectile and target ionization process of250keV H2++He is studied in chapter7. The final state electron-electron-recoil ion correlation is analyzed. Different correlation dynamics are found in the direction parallel or perpendicular to the incident projectile. The projectile molecule orientation effect of the ionization cross section is investigated in the final part of this chapter.The electron momentum spectroscopy of1-iodopropane is studied in chapter8. We find that the electron momentum profiles are influenced by the ultrafast movement of the nucleuses. The spin-orbital coupling and intramolecular inter-action have been compared.The summarization and prospects are given in chapter9.