Laser control of electron capture

Electron capture during collisions of He2+ and O6+ on state-prepared Na*(3p) was investigated by means of photo emission spectroscopy (PES). In chapter two a brief overview of the theoretical models used to describe single electron capture is given. First, the over-barrier model is dealt with, since it elucidates the dominant charge exchange processes. It is used throughout this thesis to outline the most important parameters of charge transfer for the collision systems under study. Next, the fundamentals are given of the classical-trajectory Monte Carlo calculations, which are used to support our experimental results in the last two chapters. finally an outline of close-coupling calculations is given. In chapter three a detailed desciption of the design of the apparatus, is presented, as well as the method to prepare and monitor the excited and aligned Na*(3p) target. In the second half of this thesis the experimental results are discussed. In chapter four the results of charge transfer and target excitation in the He2+ + Na(3s) collision system in the energy range 0f 2-9 keV amu-1 are given. In chapter five the experimental results for charge transfer in the He2+ + Na*(3p) collision system are presented. The influence of alignment effects on electron capture into the dominant He+(n=4) level has been studied by observing the HeII(4-3) emission line in an energy range of 3-13 keV amu-1. Finally, the O6+ + Na*(3p) collision system is presented in chapter six. 37 figs., 11 tabs., 120 refs