Performance Studies of a Quadrupole Mass Filter

Abstract

The transmission efficiency and the resolving power of a quadrupole mass filter have been investigated as functions of entrance aperture size and frequency of excitation. The aperture size was varied from 10 to 40% of the rod diameter, and the frequency of excitation from 0.87 to 1.7 Mc. Larger transmitted ion currents at lower transmission efficiencies are observed with the larger aperture sizes. Higher resolution is obtained more readily with smaller apertures and higher frequencies.