ABSTRACT
In this chapter, we introduce some fundamental aspects of core level spectroscopies. The characteristics of core holes and core level spectroscopies will be given, and x-ray absorption and x-ray emission will be discussed on the basis of the interaction of x-rays with matter. We mainly confi ne ourselves to the one-electron approximation (the effect of electron-electron interactions on the core level spectroscopy will be discussed in detail from Chapters 3 to 8). At the end of the chapter, the x-ray and electron sources that are used for the core level spectroscopy are given.
