Mass spectrometer system including an ion source operable under high pressure conditions, and a two-stage pumping arrangement

摘要

A mass spectrometer system includes an ion source effective to produce ions within a viscous flow region. A pumping arrangement is effective to produce a further viscous flow region of lower pressure than the first region, ions passing through the further region into a molecular flow region. The energy of the ions is defined as they enter the molecular flow region.