Non-linearity influences on the axial secular-motion spectrum of ions confined in a Fourier transform ion trap mass spectrometer. Experimental studies.
A Fourier transform operating mode is applied to an ion trap. The trap is truncated at 2r(0) and presents unwanted defects that induce confinement electric-field non-linearities. Ion axial secular-motion spectrum is examined by experiments near the resonance line beta(z) = 0.5. Ion-loss processes and ion axial-motion peak splitting are observed. In the non-linear ion trap, the ion-motion frequency depends on its initial conditions in position and velocity. This brings an enlargement of the motion-frequency peak and limits the resolution. With a 2r(0) truncated ion trap, the Fourier transform ion trap mass spectrometer (FTIT-MS) leads experimentally to a mass resolution of about 4000 at 130 u.
Carette
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M
Université de Provence, Ecole Polytechnique Universitaire de Marseille, Laboratoire IUSTI-UMR CNRS 6595, Equipe Instrumentation de Procédés et Systèmes en Ecoulement, Technopôle de Château-Gombert, F13453 Marseille cedex 13, France.
Zerega
Y
Y