II.

The Magnetic-Deflection Mass Spectrometer

In a magnetic-deflection mass spectrometer, ions with a positive unit charge are created from the sample and accelerated by an electrostatic field. A magnetic field deflects the ions according to their mass. Ions with a certain mass strike the detector. Less massive ions are deflected too much and miss the detector, and more massive ions are not deflected enough and miss the detector. The strength of the magnetic field slowly varies so the detector can measure the relative proportions of all the constituents of the sample. The detector is often connected to a computer that processes the data.