Temperature-Stable Magnetic Sector for Mass Spectrometer

A magnetic sector in a proposed miniature mass spectrometer would include (1) a permanent magnet made of a high-energy-product material, (2) a conventional ferromagnetic yoke, and (3) a small temperature-compensating magnetic shunt. In the absence of the temperature compensation, it would be necessary to restrict the operation of the miniature mass spectrometer to a controlled-temperature environment. With the temperature compensation, the instrument could be used to perform chemical analyses in a variety of laboratory, industrial, and field environments over a wide range of temperatures.