Abstract: The present invention relates to electron multiplier apparatus of the type used in ion detectors. In one form, the invention is an electron multiplier having two or more electron emissive surfaces, each having a different composition so as to together limit or overcome an acute gain effect on the electron multiplier due to the exposure of the two or more electron emissive surfaces to water molecules. Alternatively, the multiplier may have a single electron emissive surface of mixed composition comprising a first composition component and a second composition component so as to together limit or overcome an acute gain effect on the electron multiplier due to the exposure of the electron emissive surface to water molecules.

Abstract: Ion detectors of the type used in scientific instrumentation, such as mass spectrometers. More particularly, a self-contained particle detector includes an enclosure formed in part by a transmission mode secondary electron emissive element, the enclosure defining an internal environment and an external environment, wherein the transmission mode secondary electron emissive element has an externally facing surface and an internally facing surface and is configured such that impact of a particle on the externally facing surface causes emission of one or more secondary electrons from the internally facing surface.

Abstract: The present invention relates to electron multiplier apparatus of the type used in ion detectors. In one form, the invention is an electron multiplier having two or more electron emissive surfaces, each having a different composition so as to together limit or overcome an acute gain effect on the electron multiplier due to the exposure of the two or more electron emissive surfaces to water molecules. Alternatively, the multiplier may have a single electron emissive surface of mixed composition comprising a first composition component and a second composition component so as to together limit or overcome an acute gain effect on the electron multiplier due to the exposure of the electron emissive surface to water molecules.

Abstract: Ion detectors of the type used in scientific instrumentation, such as mass spectrometers. More particularly, a self-contained particle detector includes an enclosure formed in part by a transmission mode secondary electron emissive element, the enclosure defining an internal environment and an external environment, wherein the transmission mode secondary electron emissive element has an externally facing surface and an internally facing surface and is configured such that impact of a particle on the externally facing surface causes emission of one or more secondary electrons from the internally facing surface.