The
ionization of any species by interaction with heavy particles (which may be ions or neutral
atoms) formed as a result of the fission of a suitable
nuclide adjacent to a target supporting the sample.
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