Patent ID: 9437410
Filing Date: 2016-09-06
CPC Classification: H01J

Claim Text:
1. A mass spectrometer system comprising: an ion source for generating ions at substantially atmospheric pressure; a sampling member having an orifice therein, the sampling member forming a vacuum chamber with a mass spectrometer; a curtain plate between the ion source and the sampling member, the curtain plate having an aperture therein, the curtain plate aperture being coaxially aligned with the sampling member orifice, the aperture having a cross-section and being spaced from the sampling member to define a flow passage between the curtain plate and the sampling member, and to define an annular gap between the orifice and the aperture, the area of the annular gap being less than the cross-sectional area of the aperture; a power supply for applying a voltage to the curtain plate to direct ions from the ion source to the aperture in the curtain plate; and a curtain gas flow mechanism for directing a curtain gas into the flow passage and the annular gap, wherein the curtain gas forms a high velocity jet in front of the orifice.