Parameterization of a two-stage mass spectrometer performing second-order space focusing

High mass resolution can be achieved with a time-of-flight mass spectrometer performing first-order space focusing in combination with supersonic molecular beams. The introduction of a second-order correction of the space focus allows an enhancement of the resolution. We present a general parameterization for designing a two-stage mass spectrometer performing second-order space focusing. This formalism is well suited for the design of instruments devoted to the study of clusters in molecular beams. Numerical simulations of the performance are presented.