Photoionization process in the ionosphere

ABSTRACTMs.c.ThesisPHOTOIONIZATION PROCESS IN THE IONOSPHERESerap CEZİBARAKFırat UniversityGraduate School of Natural and Applied SciencesDepartment of Physics2005, Page: 50In this study, photoionization processes in the ionosphere and the effects of loss and gain, dueto by physical and chemical processes on the ionosphere have been investigated. Photoionization dueto the Solar EUV and X-rays has been changed by the the flux strength, different wavelength solarradiations ionizes different atoms and molekules, density of atom molecules, their present height in theionosphere and ionization cross sections. Also, It has been needed more energy when the second andthird ionization happened and ionization cross sections changed with the structural features of theionospheric components. It has been determined that charge exchange reactions, cosmic radiation andcollisions cause the photoionization. Mostly atomic oxygen, moleculer oxygen and molecular nitrogenassist to the free electron production in the ionosphere.Keywords:Ionosphere, Photoionization, Photoionization cross sectionX