Stacked ring ion guide

Giles, K. Pringle, S.D. Worthington, K.R. Little, D. Wildgoose, J.L. Bateman, R.H., Applications of a travelling wave-based radio-frequency-only stacked ring ion guide. Rapid Commun. Mass Spectrom. 2004, 18, 2401-2414. 

The initial setup was developed into a hybrid quadrapole-ion-mobility-TOF instrument [148], The collision cell region of this instrument features three traveling-wave stacked ring ion guides, of which the middle one is used as ion-mobility drift tube and the other two may be used as collision cell, when applicable. The 185 imn long IMS part is operated at pressures up to 1 mbar with up to 200 ml/min Ar whereas the collision cells are 100 mm long and operated at 10 mbar with up to 10 ml/min gas [148]. The system can be used for a wide variety of applications. 

Fig. 4.70. A stacked ring ion guide. Rings are connected to an RF drive voltage in alteration of the phase. Normally tens of pairs are used to build one ion guide. Ions entering from the left experience a deep radial potential well with comparatively steep walls toward the inner ring surfaces when traveling though the apertures. Reproduced from Ref. [242] with permission. Elsevier Science Publishers, 2007.

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