Mass Analyzer; Figure 20. Ltq Xl Linear Ion Trap Rod Assembly - Thermo Scientific LTQ Series Hardware Manual

Mass Analyzer

Components
Thermo Scientific
The mass analyzer is the site where ion manipulation and mass analysis occur, which includes
ion storage, ion isolation, CID, and ion ejection. This section describes the components of
the mass analyzer, voltages applied to the mass analyzer electrodes, presence of helium
damping gas in the mass analyzer cavity, and mass analyzer operation during mass analysis.
The LXQ and LTQ XL mass spectrometers contain a single two-dimensional linear ion trap.
The Velos Pro mass spectrometer contains a dual-cell two-dimensional linear ion trap.
The linear ion traps are square arrays of precision-machined and precision-aligned hyperbolic
rods. In the LXQ and LTQ XL mass spectrometers, the two rods in the x-dimension have
slots. In the Velos Pro mass spectrometer, all rods have a slot. Ions are ejected only through the
x-rods during scan out. In each trap, rods opposite each other in the array are connected
electrically. You can consider the four rods of each section to be two pairs of two rods each.
LXQ and LTQ XL
The mass analyzer in the LXQ and LTQ XL mass spectrometers consists of a front lens, linear
ion trap, and back lens. The front and back lenses are metal plates with a circular hole in the
center through which the ion beam passes. The front and back lenses provide conductance
limits.
The LXQ rods have one section and the LTQ XL rods have three sections.
the basic design of the linear ion trap.

Figure 20. LTQ XL linear ion trap rod assembly

Y
Z
X
Center section
Front section
2
Functional Description
Mass Spectrometer
Figure 20 shows
Back section
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