Trace Analysis Using Position-Sensitive Detection in Magnetic Sector Mass Spectrometry

A position-sensitive ion detection system for trace analysis with magnetic sector mass spectrometers is described in detail, with particular application to high temperature mass spectrometry. The detection system consists of two stacked microchannel plates (Chevron assembly) backed by a resistive anode encoder and associated electronics. The range of masses simultaneously detectable is m to 1.2m. For electron impact ionization of silver at an electron energy of 10.5 eV, the sensitivity is 1.6 × 10 −7 Pa, and the mass resolution is 260 at mass 80 (valley 10% of the peak height definition). Additional applications for the detection system are discussed.