ULTRAHIGH-RESOLUTION FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE MASS-SPECTROMETER

A new Fourier transform ion cyclotron resonance mass spectrometer is described in three sections: magnet, vacuum system, and electronics/data system. Each component is described in detail (e.g., manufacturer's part numbers, drawings, circuit schematics, etc.). Of special interest is the high-frequency signal generation and processing required to extend the lower-mass limit for singly charged ions to 1 u. In particular, two new multiple heterodyne techniques for high-frequency measurements are described, as well as a method for producing a long-duration electron beam, and the implementation of z-axis ejection for selective removal of unwanted ions of various mass-to-charge ratios.