The design of an energy-focussing mass spectrometer

Abstract Two versions of a recoil mass spectrometer are discussed and compared with respect to their resolution power, solid-angle acceptance and optical properties. One version consists of a quadrupole doublet followed by an electrostatic deflector, a magnet, a second electrostatic deflector and a doublet. In the second version the doublets are replaced by triplets which results in a much better performance. The electrostatic deflectors will have a variable gap and an electrode voltage of ± 300 kV.