The content of this book describes in detail the results of the present measurements of the partial and total doubly differential cross sections for the multiple-ionization of rare gas atoms by electron impact. These measurements show, beside other trends, the role of Auger transitions in the production of multiply ionized atoms in the region where the incident electron energy is sufficient to produce inner shell ionization. Other processes like Coster-Kronig transitions and shake off also contribute towards increasing the charge of the ions. The incident electron having energy of 6 keV, for example, in a collision with xenon atom can remove up to nine electrons! (*) X-ray-ion coincidence spectroscopy of the electron xenon atom collisions is also described. The present measurements of doubly differential cross sections for the dissociative and non-dissociative ionization of hydrogen, sulfur dioxide and sulfur hexa fluoride molecular gases by electron impact are also described in the text of this book. The results of the measurements for sulfur dioxide molecule show how this major atmospheric pollutant can be removed from the atmosphere by electron impact dissociation of this molecule. The present results of the measurements for sulfur hexa fluoride give an insight into the dissociation properties of this molecular gas, which is being so widely used as a gaseous insulator in the electrical circuits. The book also describes the present measurements of the polarization parameters of the fluorescence radiation emitted by the electron-impact-excited atoms of sodium and potassium. In these investigations the target atoms are polarized, therefore, the measurements of the polarization parameters give information about the electron atom interaction in terms of the interference, direct and exchange interaction channels.