Thermo Scientific ISQ, Руководство пользователя

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7
Optimizing Your Method
Modifying an Automatic Tune
94 ISQ User Guide Thermo Scientific
Figure 80. Configuring the Lenses Options
• Device —Use this pull-down menu to select the component you want to tune
according to the settings in the other columns.
– Repeller —Select this option to control how the repeller pushes the ions out of
the ionization region. The voltage applied to this component will have a very
strong effect on the energy of the ion beam, which will have a strong effect on the
resolution and the intensity. The lower the voltage, the better the resolution.
However, higher voltages will prevent ions from striking the repeller surface,
which leads to better robustness. Typical values are 0 to 5 V, although a dirty
system may have the repeller climb as high as 12.5 V. We do not recommend
setting the repeller any higher.
– Lens 1 —Select this option to control Lens 1, which is the first of three lenses
that the ions see as they leave the ionization region. These three lenses act as a
focusing element to maximize the ion beam intensity that is entering the ion
guide. This field is typically set between -35 and -50 V.
– Lens 2 —Select this option to control Lens 2, which is the second of three lenses
that the ions see as they leave the ionization region. These three lenses act as a
focusing element to maximize the ion beam intensity that is entering the ion
guide. This field is typically set between 0 and -15 V in EI mode. In CI, the
optimal voltage may be between 0 and -30 V.