5
Ion Source and Inlet Valve
Ion Source
172
DSQ II Hardware Manual
Thermo Scientific
Ion Volume
The ion volume is where the molecules interact with energetic electrons to form ions.
Different ion volumes are needed for EI, PCI, and NCI operation modes. These optimized
geometries maximize sensitivity for each ionization mode. An NCI ion volume offers a
compromise in sensitivity for both EI and CI and is best for NCI. It allows you to switch
ionization modes from one run to the next. This is especially useful for qualitative analysis.
The ion volume consists of the ion volume holder and the ion volume. The ion volume is
located in the center of the ion source.
Figure 89.
EI, PCI, NCI, and CEI Ion Volumes
1
Electron Entrance Hole
3
Ion Exit Hole
2
GC Effluent, Calibration Gas, CI
Reagent Gas entrance hole
4
Electron Exit Hole
1
Closed Exit Ion Volume
PCI Ion Volume
NCI Ion Volume
EI Ion Volume
2
3
4
1
2
3
1
2
3
4
1
2
3
4
Summary of Contents for DSQ II
Page 1: ...DSQ II Hardware Manual 120299 0002 Revision C December 1 2009 ...
Page 4: ......
Page 8: ......
Page 36: ...1 Basic Operations Shutting Down the GC MS System 20 DSQ II Hardware Manual Thermo Scientific ...
Page 198: ...5 Ion Source and Inlet Valve Inlet Valve Upgrade 182 DSQ II Hardware Manual Thermo Scientific ...
Page 202: ...6 Prefilter and Quadrupole 186 DSQ II Hardware Manual Thermo Scientific ...
Page 206: ...7 Ion Detector Electron Multiplier 190 DSQ II Hardware Manual Thermo Scientific ...
Page 242: ...226 DSQ II Hardware Manual Thermo Scientific Index ...