Secondary‐electron emission by energetic ions incident on metal surfaces

An experimental technique, especially well adapted to measure secondary‐electron coefficients for energetic ions incident on any charge‐collector surface, is described. The technique uses a laser‐produced plasma as an ion source, a high‐energy ion analyzer as an ion energy and species filter, and a tubular electrode arrangement to suppress or attract the secondary electrons at the charge collectors. The secondary‐electron coefficients for several ionization states of carbon and hydrogen ions incident on copper surfaces are given as a function of incident ion energy between 15 and 150 keV/Z.