Optimizing The Ion Source Parameters Thermostar; Thermostar™ With Test Gas Air; Thermostar™ With Calibration Unit (Pftba) - Pfeiffer Vacuum OmniStar GSD 300 O1 Operating Manual

4.4 Optimizing the Ion Source Parameters
ThermoStar™
Optimize the ion source parameters in regular intervals, in parti-
cular during the first time operation and after all service work on
the ion source.
The optimization procedure differs, depending on the existing
configuration and available test gas.
• Optimization with test gas air → section 4.4.1
• Optimization with calibration unit (PFTBA) → section 4.4.2
• Optimization with test gas argon → section 4.4.3
4.4.1 ThermoStar™ with Test Gas Air
Optimize with air if no special test gas is available.
Start <TuneUp>
In the menu bar choose <Tune>
Choose <Ion Source>
Adjust all parameters as shown in the picture below
Choose <Display/Measure Data > for displaying the peak
groups of nitrogen and oxygen
Optimize:
•
Test at which RF Polarity the better peak shapes are
obtained and choose the corresponding polarity.
•
Set Field-Axis in such a way that a useful resolution
and peak shape are obtained.
•
Alternatingly optimize Extraction and Focus to
maximum peak height.
Quit:
•
Close <Tune Ion Source QMA 200>
•
Save the changes by confirming the prompt with <YES>
•
Close <TuneUp>
BG 805 071 BE (9904) GSD300.om
4.4.2 ThermoStar™ with Calibration Unit (PFTBA)
The calibration substance PerFluorTriButylAmin yields mass
peaks up to 614 amu. It is ideal for optimizing ion source settings
in the high mass range.
Start <TuneUp>
Turn off SEM/Emission:
•
In the menu bar choose <Setup>
•
Choose <SEM/Emission Control> (or ctrl+c)
•
Turn off SEM and Filament
•
Close the window with <OK>
Open the valve of the calibration unit:
•
In the menu bar choose <Manual>
•
Choose <DI/DO...>
•
Double click Valve to activate it
•
Close the window with <OK>
Wait 10s (compensation of the pressure rise caused
by opening the calibration unit)
Turn on SEM/Emission:
•
In the menu bar choose <Setup> (or ctrl+c)
•
Choose <SEM/Emission Control>
•
Turn on SEM and Filament
•
Close the window with <OK>
In the menu bar choose <Tune>
Choose <Ion Source>
Adjust all parameters as shown in the picture below
Choose <Display/Measure Data > for displaying the peak
group around mass 129 amu
Optimize:
•
Test at which RF Polarity the better peak shapes are
obtained and choose the corresponding polarity.
•
Set Field-Axis in such a way that a useful resolution
and peak shape are obtained.
•
Alternatingly optimize Extraction and Focus to
maximum peak height.
Initial start up 21