Mass Spectroscopy (MS) Applications as Residual Gas Analyzer (RGA)

1. Mass Spectroscopy (MS) Applications as Residual Gas Analyzer (RGA)

2. Residual Gas Analyzer (RGA) Carbon Monoxide sample Various Ions e + C Hot wire + C O + O C O ++ 1) Creates an environment with a large ion population. 2) Separates ions by their mass to charge ratio. 3) Detects ions with same mass to charge ratio. A detector that senses ions that come through the quadrupoles Intensity The quadrupole rods direct select mass to charge ions down middle path depending on magnetic fields applied to pole pairs. 12 14 16 28 10 50 Mass/charge Note: The intensity of first three mass to charge ratios shown are much smaller than the intensity of the 28 m/z signal.

3. quadrupoles ion generation

4. Graph records the number and type of ions that reach the detector Atoms from vacuum chamber Detector Electromagnetic quadrupoles Select ions that reach detector Ions form and are drawn between quadrupoles 0.7 0 current hot ionizing filament Residual Gas Analyzer

5. Although the molecule was ionized into three different types of ions: The electromagnetic field around the quadrupoles only allowed the “red” type of ions to reach the detector. The “blue” ions and the “purple” ions crashed into the sides of the metal rods (the quadrupoles) before they could reach the detector.

6. This time the electromagnetic field around the quadrupoles was changed. The three types of ions were formed but the quadrupoles only allowed the “blue” type of ions to reach the detector. The “red” ions and the “purple” ions crashed into the sides of the metal rods (the quadrupoles) before they could reach the detector.

7. the electromagnetic field around the quadrupoles was changed for a third time only the “purple” type of ions reach the detector. The “red” ions and the “blue” ions crashed into the sides of the metal rods (the quadrupoles) before they could reach the detector.

8. electronics for the quadrupole mass spec vacuum chamber quadrupole mass spectrometer installed specific gas source for a vacuum training system Mass Spectra – Residual Gas Analysis The quadrupole attached to this vacuum training system is used to monitor the gas composition in the vacuum system. For this application, the mass spec is called a Residual Gas Analyzer, RGA. RGA’s are used to monitor the relative amounts of different gases in the vacuum chamber.

9. Electronics for the quadrupole mass spec Vacuum chamber Quadrupole installed in a mass spectrometer application Specific gas source for a vacuum training system Mass Spectra – Residual Gas Analysis Many high tech consumer items are made in vacuum chambers of various sizes. There are particular gases in specific amounts required for different application processes performed in a vacuum system. A quadrupole mass spec (or RGA) attached to the vacuum system is one way to monitor the gases composition and amounts in the chamber to assure high quality control.

10. Mass Spectra – RGA Spectra Mass spectra of gases in the vacuum system are analyzed by the attached RGA image and stored on a linked computer