An arrangement in which ions with a desired range of quotients mass/charge are trapped
by making them describe
stable paths under the effect of a static and a high-frequency electric quadrupole field.
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 1546