Abstract
World-wide many storage-cooler rings for highly ionized atoms are presently under construction. The common idea for all these projects is to enhance the phase-space density of the stored ions by "cooling" with a collinear, "cold" electron beam. One hopes to reach finally a relative momentum spread Δp/p of the ions smaller than 10−5. Therewith exciting perspectives would be opened for precision experiments in fundamental-, atomic- and nuclear physics. Some of those future experiments will be discussed in more detail.