Thermal ionization

Thermal ionization, also known as surface ionization or contact ionization, is a physical process whereby the atoms are desorbed from a hot surface, and in the process are ionized. Thermal ionization, also known as surface ionization or contact ionization, is a physical process whereby the atoms are desorbed from a hot surface, and in the process are ionized. Thermal ionization is used to make simple ion sources, for mass spectrometry and for generating ion beams. Thermal ionization has seen extensive use in determining atomic weights, in addition to being used in many geological/nuclear applications. The likelihood of ionization is a function of the filament temperature, the work function of the filament substrate and the ionization energy of the element. This is summarised in the Saha-Langmuir equation: