Positive ion detector for mass spectrometer - has scintillator inside upper electrode, slowing down ion flow towards emitter electrode

摘要

The positive ion detector for a mass spectrometer has a stainless steel chamber (17) with a glass window (12) under its cover. Above the glass is the photo cathode (12) of a dynamic multiplier. The inlet (19) for the ion beam is at the bottom. On a block (28) inside, with a plate electrode (16) inside, with a slot through it. At the top is an upper plate electrode (6) with an emitter electrode (8) spaced above it. Between these electrodes is an intermediate electrode (7). Above them is an electrode (9) with a glass scintillator (10) in the centre. This electrode acts as a braking electrode, absorbing energy so that the ions fall with reduced energy on the emitter electrode (8).