摘要 |
A mass spectrometer comprising: a first Time of Flight mass analyser arranged and adapted to analyse positive ions; a second Time of Flight mass analyser arranged and adapted to analyse negative ions, wherein said second Time of Flight mass analyser is arranged adjacent to said first Time of Flight mass analyser; and a pusher electrode (13) common to said first and second Time of Flight mass analysers, wherein said first Time of Flight mass analyser further comprises a first grid electrode (14a) and said second Time of Flight mass analyser further comprises a first grid electrode (14b); wherein, in use, ions are arranged to arrive in an orthogonal acceleration extraction region arranged between said pusher electrode (13) and said first grid electrodes (14a, 14b) and wherein ions are directed into either said first Time of Flight mass analyser or said second Time of Flight mass analyser by choosing the polarity of a voltage pulse applied to said pusher electrode (13). |