Ion beam analyzer and method for determining the field desorption - characteristic groe sen in the case of an ion beam analyzer

摘要

The ion beam from a field desorption source in a double focusing magnetic mass spectrometer is monitored by disabling the electric sector of the mass analyzer such that the ion beam is not deflected. An opening is provided in the wall of the electric sector such that the undeflected ion beam may pass therethrough to a detector. This permits the characteristics of the field desorption source to be ascertained more quickly and easily so that a mass analysis may be performed. The monitor may be operated automatically to vary a characteristic of the field desorption source until ions are detected. Thereafter, the electric sector is energized and an analysis performed.