Outgassing of CCD Components in the Vacuum
Annex
Annex A Manual for the residual gas analyzer
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Annex B Key fragment ions |
Annex A:
Manual for the residual gas analyzer
("Pfeiffer QMS 200 F2")
1. The software ("Quadstar 422 V 6.0")
Quadstar 422 consists of seven independent subprograms. These programs were actually developed to operate the Pfeiffer QMS 422, but most functions work for the QMS 200 in the same way. The subprograms of interest in our case are the following four:
- Measure is the actual measurement program. With this, various scans of a probe can be started and controlled.
- Dispsav is a short form for "Display Saved Values" and represents the analyzing program. Stored data can be displayed and processed here.
- Service is a service program. From here, leak tests and measurements of the total pressure can be made.
- Utility contains a spectra library.
2. Getting started
- Assemble the vacuum chamber with the turbo-molecular pump, the residual gas analyzer and a vacuum sensor. With a cable, connect the latter two.
Never run the system without this connection!
As the gas analyzer could be damaged at pressures higher than 10-4 mbar, it will be switched off automatically using this control device if critical pressures are reached. - Connect the residual gas analyzer via a serial interface with a PC or laptop. The software needs WINDOWS 3.1 or higher.
- Switch on the turbo-molecular pump, the system has to be closed before.
- Make a leak-test to check that all parts of the experimental chamber are hermetically sealed. Helium can be used as a test gas. Start the Service subprogram and click on Measure: Leak Test . A smaller window appears, in which the measured pressure in the chamber is plotted versus time.
- Start the Parset subprogram and click on Config: QMS . Check that ``SEM + FIL'' is set to ``INTERN'', so the emission can be started and switched off manually. In the same subprogram now click on Setup: General and check that the ``Simulation Mode'' is ``Off''.
3. Measuring a probe
Preparing the measurement
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Making a spectrum of a probe Start the program Measurement. Spectral scans can be plotted as a histogram ("bargraph") or as a continuous curve ("analog").
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Saving a spectrum Start a bargraph or analog scan as explained above.
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Data processing Saved spectra can be viewed in the subprogram Dispsav. Select Scan: Analog Data or Scan: Bargraph Cycles respectively.
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Printing By selecting File: Print in the subprogram Dispsav the current spectrum will be printed as an ASCII table only.
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Subtracting two spectra
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4. Known problems
- Some subprograms of "Quadstar 422 V 6.0" cannot be run simultaneously.
- Don't forget to switch off the emission explicitly. Closing the program or a reboot of the PC leaves the emission unchanged.
- There are only inconvenient possibilities of subtracting spectra.
Annex B:
Key fragment ions
Mass number [m/e] | Key fragments | Probable parent molecule | Additional mass number [m/e] |
1 | H+ | H2 | 2 |
H2O | 16, 17, 18 | ||
CxHy | 12, 13, 14, 26, 27 | ||
2 | H2+ | H2 | 1 |
He2+ | He | 4 | |
4 | He+ | He | 2 |
6 | C2+ | CO | 12, 28, 29 |
CO2 | 12, 28, 44 | ||
CxHy | 12, 13, 14, 26, 27 | ||
7 | N2+ | N2 | 14, 28, 29 |
8 | O2+ | O2 | 16, 32, 34 |
H2O | 16, 17, 18 | ||
12 | C+ | CO | 28, 29 |
CO2 | 28, 29, 44 | ||
CxHy | 13, 14, 26, 27 | ||
13 | CH+ | CxHy | 12, 14, 26, 27 |
14 | N+ | N2 | 28, 29 |
NH3 | 15, 16, 17 | ||
CH2+ | CxHy | 12, 13, 26, 27 | |
CO2+ | CO | 28, 29 | |
15 | CH3+ | CxHy | 12, 13, 14, 26, 27 |
NH+ | NH3 | 14, 16, 17 | |
16 | O+ | O2 | 32, 34 |
H2O | 17, 18 | ||
CH4+ | CH4 | 12, 13, 14, 15 | |
NH2+ | NH3 | 14, 15, 17 | |
17 | OH+ | H2O | 16, 18 |
NH3+ | NH3 | 14, 15, 16 | |
18 | H2O+ | H2O | 16, 17 |
19 | F+ | F2 | 38 |
HF | 20 | ||
20Ne+ | Ne | 22 | |
Ar2+ | Ar | 40 | |
20 | HF+ | HF | 19 |
22 | CO22+ | CO2 | 6, 12, 28, 29, 44 |
22Ne+ | Ne | 20 | |
24 | C2+ | CxHy | 12, 13, 14, 26, 27 |
26 | C2H2+ | CxHy | 12, 13, 14, 24, 27 |
27 | C2H3+ | CxHy | 12, 13, 14, 24, 26 |
28 | N2+ | N2 | 7, 14, 29 |
C2H4+ | CxHy | 12, 13, 14, 24, 26 | |
CO+ | CO | 6, 12, 29 | |
CO2 | 6, 12, 29, 44 | ||
29 | C2H5+ | CxHy | 12, 13, 14, 24, 26, 27, 28 |
14N15N+ | N2 | 7, 14, 28 | |
30 | C2H6+ | C2H6 | 12, 13, 14, 24, 26, 27, 28, 29 |
NO+ | NO | 14, 16 | |
31 | C2H2OH+ | C2H3OH | 26, 28, 29 |
CF+ | CF | ||
32 | O2+ | O2 | 8, 16, 34 |
S+ | H2S | 33, 34 | |
SO2 | 34, 64 | ||
34 | H232S+ | H2S | 32, 33 |
34S+ | 32, 33 | ||
16O18O+ | O2 | 8, 16, 32 | |
35 | 35Cl+ | Cl2 | 37, 70, 72, 74 |
HCl | 36, 37, 38 | ||
36 | H35Cl+ | HCl | 35, 37, 38 |
36Ar+ | Ar | 20, 38, 40 | |
37 | 37Cl+ | Cl2 | 35, 70, 72, 74 |
HCl | 35, 36, 38 | ||
38 | H37Cl+ | HCl | 35, 36, 37 |
C3H2+ | CxHy | 12, 13, 14, 24, 26, 27, 28 | |
38Ar+ | Ar | 20, 36, 40 | |
39 | C3H3+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38 |
39K+ | K | 41 | |
40 | Ar+ | Ar | 36, 38 |
C3H4+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 | |
41 | C3H5+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 |
41K+ | K | 39 | |
42 | C3H6+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 |
43 | C3H7+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 |
C2H3O+ | C2H5OH (alcohol) |
31, 44, 45, 46 | |
44 | C3H8+ | C3H8 | 41, 42, 43 |
CO2+ | CO2 | 6, 12, 28, 29 | |
C2H4OH+ | C2H5OH (alcohol) |
31, 43, 45, 46 | |
N2O+ | N2O | 14, 16, 28 | |
45 | C2H5O+ | C2H5OH (alcohol) |
31, 43, 44, 46 |
13CO2+ | CO2 | 6, 12, 28, 29, 44 | |
46 | NO2+ | NO2 | 14, 16 |
C2H5OH+ | C2H5OH (alcohol) |
31, 43, 44, 45 | |
48 | SO+ | SO2 | 32, 64 |
50 | CF2+ | CF2 | |
55 | C4H7+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 |
57 | C4H9+ | CxHy | 12, 13, 14, 24, 26, 27, 28, 38, 39 |
58 | (CH3)2CO+ | C3H6O (acetone) |
43 |
64 | SO2+ | SO2 | 32, 48 |
69 | CF3+ | CF3 | |
77 | C6H5+ | Phenyl | 50, 51, 52 |
78 | C6H6+ | C6H6 (benzene) |
50, 51, 52 |
"92.5" | 185Re2+ | Rhenium | "93.5", 185, 187 |
"93.5" | 187Re2+ | Rhenium (filament) |
"92.5", 185, 187 |
149 | Phthalic ester (softening agent) |
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182 | 182W+ | Tungsten (filament) |
183, 184, 186 |
183 | 183W+ | Tungsten (filament) |
182, 184, 186 |
184 | 184W+ | Tungsten (filament) |
182, 183, 186 |
185 | 185Re+ | Rhenium (filament) |
187 |
187 | 187Re+ | Rhenium (filament) |
185 |