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Ion Transmission and Mass Analysis
Ion Optics
Thermo Scientific Orbitrap Fusion Series Hardware Manual 31
The lens L0 is a metal disk with a small hole in the center through which the ion beam passes
(Figure 15). The mass spectrometer applies an electrical potential (positive for positive ions
and negative for negative ions) to lens L0 to aid in ion transmission. (The system ground is
referenced to the C-trap potential, not earth ground.) Lens L0, which mounts to the MP00
RF lens, also acts as a vacuum baffle between the MP00 and MP0 ion optics chambers.
Figure 15. Lens L0
MP0 Ion Optics
The MP0 ion optics, also called the active beam guide (ABG), transmits ions from the MP00
ion optics through a 90-degree arc along the central axis to quadrupole Q1. The curved
design reduces noise by preventing neutral species and high-velocity clusters from entering
Q1. The MP0 ion optics include multipole MP0 and lenses TK1 and TK2 (Turner-Kruger
lenses). See Figure 13 for the location of these components.
Multipole MP0 consists of a pair of PCBs arranged parallel to each other and separated by a
small distance (Figure 16). The multipole’s design of individual electrode segments allows the
mass spectrometer to implement a DC gradient in addition to the RF voltage. This provides
an axial field along the length of the device to provide fast and consistent ion flight times
through the device.
Figure 16. Multipole MP0
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