Geometry effects in the sol and divertor

Geometry effects in the SOL and divertor, which are the main focus of a variety of present tokamaks, are reviewed. Since divertor detachment constitutes a central element in this context, some basic results on divertor detachment are also summarised. The discussion of issues that played a role in recent experimental campaigns and their theoretical and numerical analysis form a major part of the paper. Emphasis is placed on gas target related effects. An attempt is made to reduce the impact of geometry to a small number of basic mechanisms.