Quadera Pfeiffer программа управления (1248465), страница 12
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The number ofavailable filaments depends on theion source type.•EmissionCurrentNumber > 0Filament emission current.FilamentProtectionCurrentNumber > 0•This parameter is applied to thefilament that is selected under"Filament Number".Maximum filament current, used toprotect the filament.This parameter is applied to thefilament that is selected under"Filament Number".105QUADERA HTML HelpParameterRangeDescription•IonReferenceAny numberIon source voltages.•Cathode•Focus•Field Axis•Extraction•InnerDeflection•OuterDeflection•Wehnelt106These parameters are applied to thefilament and the ion source type thatis selected under "Filament Number"and "Ion Source Type", respectively.The available parameters depend onthe used ion source.
For detailedinformation, please refer to theoperating instructions of the QMG andthe used ion source.You find the procedures to optimizethe ion source potentials for theQMG700 with QMA400/410/430 in theoperating instructions BG 805983BD/E.QUADERACrossbeam Ion SourceThis topic applies to the QMG220.Proceed as follows to optimize the crossbeam ion source:1. Select the filament and operate it with 1 mA emission current forapproximately half an hour. The message "Emission Error" appearsrepeatedly: start with reduced emission current and increase it slowly.Default settings:•Emission Current:1 mA•Protection Current:4.0 A•RF-Polarity:•Ion Reference:150 V•Cathode:-70 V•Focus:•Field Axis:-10 V•Extract:-50 Vpos-5 V3. Wait until the pressure reaches < 10-7 mbar and the residual gas spectrumremains stable.4.
Introduce a test gas, such as air, into the recipient for a pressure of 10-6 mbar.Otherwise, use the residual gas to perform the optimization procedure.5. Repeatedly record spectra of the relevant peaks (e.g. 25…34 m/e). Observeintensity, resolution, and peak shape.6. Optimize the ion source voltages:a. Check which "RF-Polarity" ("pos" or "neg") results in the better peak shapeand select this polarity.b. Optimize "Cathode" for best sensitivity.c.
Adjust "Field Axis" for useful resolution and peak shape.d. Optimize "Extract" and "Focus" alternately for maximum peak height.The ion source is optimized.107QUADERA HTML HelpGrid Ion SourceThis topic applies to the QMG220.Proceed as follows to optimize the grid ion source:1. Select the filament and operate it with 2 mA emission current forapproximately half an hour. The message "Emission Error" appearsrepeatedly: start with reduced emission current and increase it slowly.Default settings:•Emission Current:2 mA•Protection Current:4.0 A•RF-Polarity:•Ion Reference:150 V•Cathode:-90 V•Field Axis:-12 VposVary the "Field Axis" potential to optimize sensitivity, peak shape, andresolution.3.
Wait until the pressure reaches < 10-8 mbar and the residual gas spectrumremains stable.4. Repeatedly record spectra of the relevant peaks (e.g. 25…34 m/e). Observeintensity, resolution, and peak shape.5. Optimize the ion source voltages:a. Check which "RF-Polarity" ("pos" or "neg") results in the better peak shapeand select this polarity.b. Optimize "Cathode" for best sensitivity.c. Adjust "Field Axis" for useful resolution and peak shape.The ion source is optimized.108QUADERASPM Ion SourceThis topic applies to the QMG220.Proceed as follows to optimize the SPM ion source:1.
Select the filament and operate it with 1 mA emission current forapproximately half an hour. The message "Emission Error" appearsrepeatedly: start with reduced emission current and increase it slowly.2. Introduce a process gas, such as argon, into the process chamber for apressure of 10-3…10-2 mbar.3. Repeatedly record spectra of the relevant peaks (e.g. argon 32…41 m/e).Observe intensity, resolution, and peak shape.Default settings:•Emission Current:1 mA•Protection Current:•Ion Reference:•Cathode:•Focus:-2.0 V•Field Axis:-2.0 V•Extract:3.5 mA105 V-40.0 V-60 V4. Optimize the ion source voltages:a.
Set "Field Axis" to -5 V.b. Decrease "Field Axis" for useful resolution and peak shape.The ion source is optimized.109QUADERA HTML HelpOpen High Sensitivity Ion SourceThis topic applies to the QMG220.Proceed as follows to optimize the open high sensitivity ion source:1. Select the filament and operate it with 2 mA emission current forapproximately half an hour ("Protection Current" at 3.5 A). The message"Emission Error" appears repeatedly: start with reduced emission current andincrease it slowly.Default settings:•Emission Current:2 mA•Protection Current:3.5 A•RF-Polarity:•Ion Reference:150 V•Cathode:-75 V•Focus:-5 V•Field Axis:-7 V•Extract:pos-50 V3. Wait until the pressure reaches < 10-7 mbar and the residual gas spectrumremains stable.4.
Introduce a test gas, such as air, into the recipient for a pressure of 10-6 mbar.Otherwise, use the residual gas to perform the optimization procedure.5. Repeatedly record spectra of the relevant peaks (e.g. 25…34 m/e). Observeintensity, resolution, and peak shape.6. Optimize the ion source voltages:a. Check which "RF-Polarity" ("pos" or "neg") results in the better peak shapeand select this polarity.b. Optimize "Cathode" for best sensitivity.c.
Adjust "Field Axis" for useful resolution and peak shape.d. Optimize "Extract" and "Focus" alternately for maximum peak height.The ion source is optimized.110QUADERAGastight High Sensitivity Ion SourceThis topic applies to the QMG220.Proceed as follows to optimize the gastight high sensitivity ion source:•Using air as test gas,•Using argon and avoiding double ionizationUsing air if no specific test gas is available1. Select the filament and operate it with 1 mA emission current forapproximately half an hour ("Protection Current" at 3.5 A).
The message"Emission Error" appears repeatedly: start with reduced emission current andincrease it slowly.Default settings for air as test gas:•Emission Current:1 mA•Protection Current:3.5 A•RF-Polarity:•Ion Reference:150 V•Cathode:-60 V•Focus:-5 V•Field Axis:-7 V•Extract:pos-50 V2. Repeatedly record spectra of the relevant peaks (e.g. 25…34 m/e). Observeintensity, resolution, and peak shape.3. Optimize the ion source voltages:a. Check which "RF-Polarity" ("pos" or "neg") results in the better peak shapeand select this polarity.b. Optimize "Cathode" for best sensitivity.c.
Adjust "Field Axis" for useful resolution and peak shape.d. Optimize "Extract" and "Focus" alternately for maximum peak height.The ion source is optimized.111QUADERA HTML HelpUsing argon and avoiding double ionization1. Select the filament and operate it with 1 mA emission current forapproximately half an hour ("Protection Current" at 3.5 A). When the message"Emission Error" appears repeatedly start with reduced emission current andincrease it slowly.Default settings for argon as test gas:•Emission Current:1 mA•Protection Current:3.5 A•RF-Polarity:•Ion Reference:105 V•Cathode:-40 V•Focus:-5 V•Field Axis:-6 V•Extract:pos-50 V2.
Repeatedly record spectra of the relevant peaks (e.g. 35…42 m/e). Observeintensity, resolution, and peak shape.3. Optimize the ion source voltages:a. Check which "RF-Polarity" ("pos" or "neg") results in the better peak shapeand select this polarity.b. Leave "Cathode" at -40 V to avoid double ionization.c.
Adjust "Field Axis" for useful resolution and peak shape.d. Optimize "Extract" and "Focus" alternately for maximum peak height.The ion source is optimized.112QUADERATuning the Mass ScaleCalibrating the Mass ScaleBasicsGas components are represented by integer mass numbers. Typically, the measuringapparatus causes small deviations between the nominal mass number and the actualposition of the peak maximum. The correct position of the peak maxima is usuallyclose to theoretical value, e.g.
at 13.95 instead of 14.00. However, an exactmeasurement requires measuring the peak maximum. To achieve best accuracy inmeasurements, the exact position of the peak maxima has to be determined bycalibrating the mass scale.ProcedureQUADERA® uses two steps to calibrate the mass scale:•Coarse tuning:Two parameters are used to shift and to shrink or stretch the mass scale. Thiscoarse tuning will be applied to all measurements,•Fine tuning:The fine tuning is based on the coarse tuning and compensates nonlinearity ofthe mass scale.
This fine tuning is applied to sample measurements and scanstair measurements, and also to scan-analog measurements with theQMG700.Two scan analog measurements in various mass ranges are used for tuning of themass scale. The recipe parameters are defined in the calibration project for the massscale. Use the recipe editor to change the parameters. Normally, scanned massesrange from one up to many masses.NOTE:It is preferred that the two scans cover a mass range as wide as possible.One peak should appear at a very low mass number, another one at a veryhigh mass number.Scan recording begins when the calibration project is started.
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