vertical ionization

https://doi.org/10.1351/goldbook.V06610
A process whereby an electron is removed from a molecule in its ground or an @E02257@ so rapidly that a positive ion is produced without change in the positions or momenta of the atoms. The resultant ion is often in an @E02257@.
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 [Terms] [Paper]