Circular Mass Spectrometer for High Speed Gas Analysis

The circular cycloidal mass spec (our patent application 10/981,511) is derived from the standard linear cycloid analyzer. Instead of crossed uniform electric and magnetic fields, the electric field has circular symmetry. Thus the ion trajectories proceed periodically around the center. This provides long trajectories (high resolution) within a small analyzer, typically 50 mm in diameter (low weight, low cost). We propose the arrangement of two concentrically arranged analyzers, the inner one for H2 and He separation and the outer one for N2, O2, and Ar. Five collectors allow the simultaneous continuous registration of all gases without scanning the field (high speed analysis). The pumping system will contain an ion getter triode pump and a non-evaporable getter pump combination. As an inlet we propose a fast 1-step membrane inlet. The complete unit will require less than 3500 cm3 with a weight of ca. 10 kg.