Liquid metal ion source

A liquid metal ion source (LMIS) is an ion source which uses metal that is heated to the liquid state and used to form an electrospray to form ions. An electrospray Taylor cone is formed by the application of a strong electric field and ions are produced by field evaporation at the sharp tip of the cone, which has a high electric field. Ions from a LMIS are used in ion implantation and in focused ion beam instruments. Typically gallium is preferred for its low melting point, low vapor pressure, its relatively unreactive nature, and because the gallium ion is sufficiently heavy for ion milling.