Structure and emission of highly ionized atoms

After a brief review concerning the production of highly ionised atoms and the various radiation phenomena caused by ionised species in plasmas, the internal structure of atoms and ions and their oscillator strengths are discussed in detail as a function of the nuclear charge. Special attention is paid to many electron systems which show strong restructuration effects in their level system accompanied by irregularities of the oscillator strengths of individual spectral lines. These irregularities are caused by different effects such as level crossing and configuration interaction. Relativistic effects play an important role in the ground complex of many-electron systems. Examples are given which show the close relation between level restructurating and change of the oscillator strengths within given isoelectronic sequences as a function of nuclear charge. The influence of very strong magnetic fields on the level structure and on the oscillator strengths of hydrogen-like species is also discussed