Patent ID: 9640379
Date: 2017-05-02
CPC Classifications: H01J

Claim:
1. A method of operating a mass spectrometer vacuum interface comprising a skimmer apparatus having a skimmer aperture and an internal surface, the method comprising: providing a channel-forming member within the skimmer apparatus to divide a region within the skimmer apparatus into a central region and an outwardly extending channel region and to establish an outwardly directed flow along the internal surface of the skimmer apparatus to remove or significantly reduce the opportunity for material to be deposited on the internal surface of the skimmer apparatus, the channel-forming member being disposed within a recess in the internal surface and in conductive contact with the skimmer apparatus whereby the channel-forming member is electrically neutral relative to the skimmer apparatus, wherein the outwardly directed flow is a laminar flow from the skimmer aperture.