Abstract
A time-of-flight mass spectrometer controlled by a micro-computer has been proposed. The operating procedure of this instrument is based on a pulse counting technique. The instrument has following operating modes : 1) qualitative mass analysis and 2) simultaneous analysis of three kinds of ions. One of these modes can be selected from the software installed in the micro-computer. The spectrometer has been applied to dc vacuum prebreakdown measurements. It is found that carriers of the prebreakdown currents are ions of residual gases in a vacuum chamber. The usefulness of this system for analyzing ions of low intensity has been demonstrated.
