Chapter 13 - Selected Topics II: Hollow atoms in micro-capillaries

Abstract

The chapter discusses collisions of low-energy multicharged ions with metal and other surfaces. When a highly charged ion approaches a metal surface, it is accelerated toward the surface by interacting with its image charge. Before plunging into the surface, it captures target electrons into excited states, mainly into outer shells with radii much larger than those of the shells initially occupied. As a result, a hollow atom is formed, in which outer shells are populated, whereas inner shells still remain vacant. The classical over-barrier model is employed in various connections within atomic collision physics and is adopted to ion-surface processes. It is found that although, for a fixed position of one of the charges, the potential is proportional to the inverse distance, the change of the image charge's position during the approach leads to a reduction by a half factor.