In an electron multiplier (discrete dynode detector), one electron triggers the release of more electrons in a cascade.
Is it possible that a "large" number of electrons hitting the detector can temporarily (course of hours) reduce the number of electrons available to amplify future incident electrons? (E.g. is there a cumulative recharge time?)
Or is it possible for the anode to have temporarily reduced sensitivity if the electrons are not flushed quickly enough?
(Assume real-world, non-ideal physics. This is an actual mass spec we're talking about. Something is causing reduced sensitivity over the course of hours of usage, aside from reduced transmission and ionization due to dirt.)