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Figure 1. RGA Recall Screen of Cart #3 Data

Image Removed

Figure 2. Leak Valve 

Figure 3. Calibration Percentage Calculations

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Step 1: Faraday Calibration

1. Close 'Process Eye Window' fully, and reopen.
2. Select the EasyView window and select the Faraday calibration and hit next
3. In the next window, be sure that the correct RGA head is selected and hit next. 
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4. Under “configuration name” select EasyView. This window will show you the current settings for the device that was selected in the previous screen. Write down these values (Current Faraday Sensitivity, last calibrated, Electron energy, Filament Emission, Ion Energy, and Extractor Volts). Hit next
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5. This window asks to select the mass peak to use for calibration. Type 28 into the field for the mass to be used for Faraday calibration and use the pressure at the cold cathode (1e-6 Torr) as the anticipated process pressure gauge reading. Use the calculated contribution percentage from the spreadsheet. Hit next.
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6. This window gives you various runtime options. Select:
   1. Run with no operator intervention
   2. Acquire data from the peak center only
   3. Apply the results of this calibration to both filaments.
   4. **** Double check that the pressure at the cold cathode still reads what you said the anticipated pressure gauge reading would be and if not open the leak valve slightly more and hit finish.
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7. Start collecting data in EasyView with the Faraday cup and wait until it gives a sum of scanned mass value. Compare this to the value at the cold cathode. If it is within a factor of 3 of the cold cathode then continue. If not, repeat the calibration.

Step 2: Multiplier 1&2 Calibration

1. Close 'Process Eye Window' fully, and reopen.
2. Select the multiplier calibration button  and hit next.
3. Choose 'Multiplier 1' and hit next
4. Select 'Use Faraday detector to determine the pressure at the calibration mass and hit Next
   1. Image Added
5. Change the mass to be used to 28 and hit next
6. Select 'Define the gain in terms of the exact gain
   1. Enter 50 for the Detector gain and hit Next
7. Select 'Run with no operator intervention', 'acquire data from the peak centre only', and 'apply the results of this calibration to both filaments'
   1. Double Check that the pressure at the CCG still reads the anticipated value, if not, open the leak valve slightly to until CCG reads that anticipated value
8. Hit Finish
9. Repeat M1 Steps 1-7 for Multiplier 2 calibration, except now entering 100 for Detector gain

Step 3: Multiplier 3 Calibration

**This step requires a lower pressure throughout the system, so close the leak valve, allowing systems to reach e-8's or e-9s regime. Mentioned regime is required for Multiplier 3 to function properly.

1. Close 'Process Eye Window' fully, and reopen.
2. Once in the e-8 or e-9 regime, Select the multiplier calibration button Image Added and hit next.
3. Scale to an externa, pressure gauge on the process Chamber
   1. Insert CCG Value
4. Change the mass to be used to 28 and hit next
5. Select 'Define the gain in terms of the exact gain
   1. Enter 200 for detector gain
6. Select 'Run with no operator intervention', 'acquire data from the peak centre only', and 'apply the results of this calibration to both filaments'
   1. Double Check that the pressure at the CCG still reads the anticipated value, if not, open the leak valve slightly to until CCG reads that anticipated value
7. Hit Finish

Step 4: Testing Calibration Status/Effectivity

**For pressures lower than 1e-7, multiplier 3 should be used for scanning.

1. Collect data, about 4 scans, in accuracy 5, with Multiplier 3.
2. Observe the pressure (sum of scanned masses) at the RGA head
3. It should now be within a factor of 2 of the CCG
   1. If this is not the case, repeat the calibration process for the multipliers, increasing or decreasing the gain depending on if the pressure reads to low or too high, respectively
4. Collect 2 hours of data, Accuracy 6, and report RGA status to Peter, and later to ServiceNow

Related Documents

• HPS_FRS_Template_and_Outline .docx 
  • Look at section 7.2 (RGA Calibration)

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