SEARCH Articles Figures Tables A cut-away view of the Theimo Fisher Orbitrap mass analyzer. Ions are moving in spirals around a spindle-hke-shaped central electrode . An image current induced by moving ions is detected via a differential amplifier between the two halves of the outer orbitrap electrode. The m z of different ions in the orbitrap can be determined from respective frequencies of oscillation after a Fourier transform. Reproduced from Ref. with permission. Wiley-VCH, Weinheim, 2006. [Publishers Imprint]