Ion Optics; Figure 15. Mp00 Rf Lens (Ltq Xl On The Left And Velos Pro On The Right) - Thermo Scientific LTQ Series Hardware Manual

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Functional Description
Mass Spectrometer

Ion Optics

MP00 Ion Optics
MP0 Ion Optics
20 LTQ Series Hardware Manual
The following ion optics focus the ions produced in the API source and transmit them to the
mass analyzer:
• MP00 Ion Optics
• MP0 Ion Optics
• MP1 Ion Optics
The MP00 ion optics are the optics located closest to the API source. The MP00 ion optics
include the MP00 rf lens and the lens L0.
For the LXQ, LTQ XL, and LTQ Velos mass spectrometers, the square-metal elements of the
MP00 rf lens act as an ion-focusing device (first image in
spectrometer, the MP00 rf lens is an array of eight cylindrical metal elements (second image
in Figure 15). An rf voltage applied to the elements creates an electric field that guides the ions
along the axis of the lens. A dc voltage offset from ground applied to multipole MP00 (called
the multipole 00 offset voltage) increases the translational kinetic energy of the ions that
emerge from the skimmer or exit lens. During ion focusing, the offset voltage is negative for
positive ions and positive for negative ions.

Figure 15. MP00 rf lens (LTQ XL on the left and Velos Pro on the right)

The lens L0 is a metal plate with a small hole in one end through which the ion beam passes.
A potential is applied to lens L0 to aid in ion transmission. Lens L0 also acts as a vacuum
baffle between the multipole MP00 and MP0 ion optics chambers.
The MP0 ion optics transmit ions from the MP00 ion optics to the mass analyzer. The MP0
ion optics include MP0 and lens L1.
The square-profile rods of the multipole MP0 act as an ion transmission device
and Figure 17). An rf voltage applied to the rods creates an electric field that guides the ions
along the axis of the multipole. The MP0 offset voltage increases the translational kinetic
energy of ions that emerge from MP00.
Figure 15). For the Velos Pro mass
(Figure 16
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