Pulse mode electron generator
AssigneeAlcatel
InventorDidier Pierrejean
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Abstract
The pulse mode electron generator of the invention includes a field emission cathode with electron-emitting micropoints associated with a grid biased by means for positively biasing the grid and an anode attracting electrons emitted by the cathode. The grid is biased by a permanent positive pre-bias voltage generator delivering a rest voltage which is slightly lower than the emission threshold voltage of the cathode and in series with a positive pulse voltage generator delivering a pulse component of sufficient value to exceed the emission threshold voltage of the cathode. This facilitates the pulse mode production of electrons and reduces the power consumption needed to produce the electrons.
Claims8
A pulse mode electron generator including a field emission cathode with electron emitting micropoints associated with a grid biased by means for positively biasing the grid and an anode attracting electrons emitted by the cathode, wherein the means for positively biasing the grid generate a grid bias voltage taking:
- a rest voltage value which, during non-emission of electrons, remains between zero and the active bias voltage of the grid from which the anode receives a non-negligible flow of electrons from the cathode, or
- an emission voltage value which, during emission of electrons, is higher than an active bias voltage of the grid.
A time-of-flight mass spectrometer, including a pulse mode electron generator having a field emission cathode with electron-emitting micropoints associated with a grid biased by means for positively biasing the grip and an anode attracting electrons emitted by the cathode, wherein the means for positively biasing the grid generate a grid bias voltage taking:
- a rest voltage value which, during emission of electrons, remains between zero and the active bias voltage of the grid from which the anode receives a non-negligible flow of electrons from the cathode, or
- an emission voltage value which, during emission of electrons, is higher than said active bias voltage of the grid.
A pulse mode electron generator including a field emission cathode with electron emitting micropoints associated with a grid biased by means for positively biasing the grid and an anode attracting electrons emitted by the cathode, wherein the means for positively v biasing the grid generate a grid bias voltage taking:
- an emission voltage value which, during emission of electrons is higher than an active bias voltage of the grid, or
- a rest voltage value which, during non emission of electrons, remains between 0 volt and the said active bias voltage of the grid.
A pulse mode electron generator including a field emission cathode with electron emitting micropoints associated with a grid biased by means for positively biasing the grid and an anode attracting electrons emitted by the cathode, wherein the means for positively biasing the grid generate a grid bias voltage comprising a permanent positive pre-bias voltage on which is superimposed a positive bias voltage pulse component.
Dependencies are inferred from the claim text.