Thermal ionization

The ionization of a neutral species through contact with a high temperature surface.

This occurs where an atom or molecule interacts with a heated surface or is in a gaseous environment at high temperature. (Examples include a capillary arc plasma, a microwave plasma and an inductively coupled plasma.)

http://goldbook.iupac.org/T06303.html

Takes place when an atom or molecule interacts with a heated surface or is in a gaseous environment at high temperature. Examples of the latter may be a capillary arc plasma, a microwave plasma or an inductively coupled plasma.

Source:

PAC, 1991, 63, 1541 (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1548

Orange Book, p. 203

Method used to ionize solid samples on a hot surface of a metal filament.