Mass Spectrometer Analysis

The image below is a mass spectrometer analysis of the residual gases remaining in a high vacuum system after pumping to a pressure around 10-10 torr and baking at around 150 C. The water, carbon monoxide and carbon dioxide are commonly the remaining gases in laboratory high vacuum systems. The largest signal was from molecular hydrogen, with a peak height almost three times that of carbon monoxide. The peak at 19 had been puzzling to the experimenters until they had determined that teflon releases some flourine at those temperatures, so the source was apparently the teflon insulation on wires inside the vacuum. The vertical axis shows ion current in 10-7 Amperes.

Image courtesy of Victor Bellito

Magnetic field concepts
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