ABSTRACT
The electron beam ion source (EBIS) was invented by Donets in 1965. The story of elecrton beam ion trap (EBIT) starts with experience from the Berkeley EBIS. The distinction between EBIS and EBIT as different devices is therefore arbitrary; to conclude, S stands for source, T stands for trap; a more precise name for a device that may serve both applications could be EBIST. The basic layout of an EBIS/T essentially looks like a traveling-wave tube amplifier, waiting for modulation. While EBIT finds its application in atomic physics studies, EBIS is a successful injector of fully stripped light ions into synchrotrons but also may be useful for high-charge states of heavy ions. Important for the understanding of EBIS/EBIT physics is the space charge compensation by thermal ions, the heating of trapped ions by electrons, the cooling by ion-ion collisions, and the combined influence on the charge evolution under stepwise ionization.
