Time-of-flight mass spectrometer with spatial focusing of a broad mass range

摘要

The invention relates to time-of-flight mass spectrometers which operate with pulsed ionization of superficially adsorbed analyte substances and with an improvement in the mass resolution by means of a time-delayed start of the ion acceleration; in particular with ion-accelerating voltages which change over time after a delayed start in order to obtain a constant mass resolution over broad mass ranges. Since the varying acceleration produces a broadening of the ion beam at right angles to the direction of flight, and this broadening increases with the ion mass, the invention proposes to compensate, to the desired extent, for the broadening of the ion beam with the aid of an additional ion-optical lens whose voltage is also varied over time. The invention also relates to measurement methods therefor.