4
Ion Transmission and Mass Analysis
Ion Optics
34 TSQ Endura and TSQ Quantiva Hardware Manual Thermo Scientific
The ion optics focus the gas-phase sample ions into the mass analyzer. This section describes
the following:
• MP00 Ion Optics
• MP0 Ion Optics
MP00 Ion Optics
Ions pass through the exit lens and move toward the MP00 ion optics, which are located
between the API source interface and the MP0 ion optics. The MP00 ion optics include the
MP00 RF lens and the L0 lens. For the location of these components, see Figure 17.
The MP00 RF lens is an array of eight metal elements (Figure 18). The mass spectrometer
applies an RF voltage to the elements, generating an electric field that guides the ions along
the axis of the lens.
A DC voltage offset from ground and applied to MP00 (called the MP00 offset voltage)
increases the translational kinetic energy (TKE) of ions emerging from the exit lens. During
ion focusing, the offset voltage is negative for positive ions and positive for negative ions.
Increasing the offset voltage increases the TKE of the ions.
Figure 18. MP00 RF lens
The lens L0 is a metal disk with a small hole in the center through which the ion beam passes
(Figure 19). The mass spectrometer applies an electrical potential (positive for positive ions
and negative for negative ions) to lens L0 to aid in ion transmission. Lens L0, which mounts
to the MP00 RF lens, also acts as a vacuum baffle between the MP00 and MP0 ion optics
chambers.
Figure 19. Lens L0
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