GB814134A - Magnetic electron multiplier - Google Patents

Abstract

814,134. Electron multipliers. BENDIX AVIATION CORPORATION. Feb. 22, 1956 [Feb. 28, 1955], No. 5528/56. Addition to 811,452. Class 39(1). An electron multiplier as specified in Claim 6 of the parent Specification includes further electrodes defining a second channel extending generally transversely to the first channel defined between the switching plates of the prior Specification, with the first channel opening into one side of the second channel, and means are provided for normally maintaining one electric field in the second channel to deflect the electrons in one direction through that channel and also for imposing a different electric field in the second channel to deflect the electrons in the opposite direction. As shown the electron stream from a cathode 10 at -75 volts i.e. a plate of the multiplier of the prior Specification is introduced through a gate device 12 corresponding to that described in that Specification which operates to permit or prevent the passage of electrons into the space between first and second electrodes 18, 20 at - 180 and 0 volts respectively and is then deflected to anode 26 or anode 28 at zero potential according as to whether the parallel control electrode 22, normally at +20 volts, is being subjected to a pulse of -220 volts from a generator 38 or not, the stream also being subjected to a normal magnetic field of 350 gauss from pole pieces 40. The multiplier and switch are used in conjunction with a time-of-flight mass spectrometer.