Electron source
AssigneeIsotopx Ltd
InventorsDamian Paul Tootell, Anthony Michael Jones
Life of this patent
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Abstract
An electron source in a gas-source mass spectrometer the electron source comprising: an electron emitter cathode presenting a thermionic electron emitter surface in communication with a gas-source chamber of the gas-source mass spectrometer for providing electrons there to; a heater element electrically isolated from the electron emitter cathode and arranged to be heated by an electrical current therein and to radiate heat to the electron emitter cathode sufficient to liberate electrons thermionically from said electron emitter surface, therewith to provide a source of electrons for use in ionising a gas the gas-source chamber.
Claims17
A gas-source mass spectrometer comprising an electron source, the electron source comprising:
- an electron emitter cathode presenting a thermionic electron emitter surface in communication with a gas-source chamber of the gas-source mass spectrometer for providing electrons there to;
- a heater element electrically isolated from the electron emitter cathode and arranged to be heated by an electrical current therein and to radiate heat to the electron emitter cathode sufficient to liberate electrons thermionically from said electron emitter surface, therewith to provide a source of electrons for use in ionising a gas the gas-source chamber;
- in which the electron emitter cathode comprises a base part which bears a coating of thermionically emissive material presenting the electron emitter surface;
- and
- in which said coating comprises a material selected from:
- an alkaline earth oxide;
- osmium (Os);
- ruthenium (Ru).
Dependencies are inferred from the claim text.