Early in 1989, while most of us were gathered in the Mediterranean five-centuries-old city of Alacant, the idea of a school on stopping and particle penetration phenomena came to our minds. Later that year when discussing this plan with some of the participants in the 13th International Conference on Atomic Collisions in Solids in Aarhus, we were pleased to note that the proposal was warmly welcomed indeed by the community. An Advanced Study Institute on this or a related subject had not been organized in the last decade. Because of the progress made particularly in the interaction of high...