Ionization Photoelectron Interference Effects And Dynamics Properties Of The Imaging Spectroscopy

With the advent of the quantum electrodynamics and laser, the interactions between the material and light become the focal point of the academia. The interactions between the light and molecular lead to the molecular dissociation, the interactions between the light and atoms can cause the electrons ionization. The study of the photoionization is a very effective tool to the research of the internal structure for the atoms and molecular. And the photoelectron spectroscopy has been widely used to study photoionization and photodetachment processes of various species from atoms to clusters.In this paper, a new photoelectron spectrometer of the photoelectron spectroscopy imaging technique has been used to analyze the process of photoionization. The paper is divided into four parts:Part One: Some of the basic theory for the paper.Part Two: Theoretical explanations of the technique photoelectron imaging: The principle of the photoelectron imaging spectroscopy and the theory deduction are presented. Also, the theoretical analysis of the photoelectron image on the detector is advanced. The electronic excitation and the ionization process of the density matrix equation are obtained. The value for simulation is derived by the numerical method (Runge-Kutta method).Part Three: Based on the principle of the photoelectron imaging spectrometry, taking sodium atoms as an example, the characters of the photoelectrons angular distribution and the interference effect , which are produced from double-level of the D state of the atomic sodium, are investigated analytically by using the two-photon resonance and three-photon ionization. The energy and the space angular distribution of the photoelectrons are described expressly by the photoelectron imaging. The results show that, the spatial distribution of photoelectrons is closely related to spherical harmonics Y_LM^* (θ,(?)), this function led the spatial distribution of the photoelectron. As a result of the interaction of multi-channel ionization would lead to the coherent superposition of photoelectron in the detector , the photoelectron angular distribution patterns become more complex. The result for the analysis of the photoelectrons angular distribution possesses significances.Part Four: The technique of photoelectron imaging spectroscopy allows direct visualization on a position sensitive detector of the initial velocity and the angular distribution of electrons emitted in a photoionization process. The interaction of the photoelectron with its ionic core is neglected. This is realistic for the case of electrons of kinetic energy large enough. However, the Coulomb attraction between the electron and the ionic core cannot be neglected when slow electrons are concerned. At low initial kinetic energy, it is possible to obtain a photoelectron image displaying a complex structure which carries additional information on the initial velocity distribution, instead of the single ring expected for a single ionization channel. The paper is based on the equation of the movement of the photoelectrons in the parabola coordinates, the trajectory and movement characteristic of the photoelectrons are analyzed for the various cases. The radiuses of the photoelectrons project onto the detector are investigated for the photoelectrons taking on various kinetic energies. The results show that the fast photoelectron imaging spectrometry shows the energy feature of the photoelectrons, as well as the information of the space distribution of the photoelectron orbital. The slowing photoelectron imaging spectrometry is correlative with the energy of the photoelectron, and the photoelectrons focus mostly on the center of the photoelectron imaging spectrometry.