Gas Scattering as a Limit to Trace Sensitivity in Analytical Mass Spectrometers

Publisher Website
Google Scholar
Abstract
The distribution of elastically scattered ions in the image plane of a one-directional focusing mass spectrometer is calculated. The spectrometer is of the homogeneous magnetic sector type with the exit slit inside the field. It is shown that elastic scattering of beam ions by residual gas molecules results in peak broadening incompatible with the requirement of a high abundance sensitivity. A special two-sector instrument with reduced scattering contribution is proposed.