Aperture Gas Flow Restriction

摘要

A mass spectrometer is disclosed comprising two vacuum chambers maintained at different pressures. The two vacuum chambers are interconnected by a differential pumping aperture. The effective area of the opening between the two vacuum chambers may be varied by rotating a disk having an aperture in front of the differential pumping aperture so as to vary the gas flow rate through the opening and between the two chambers.

主权项

1. A mass spectrometer comprising:
two chambers to be maintained at different pressures in use, wherein the two chambers are interconnected by an opening for transmitting ions from one of the chambers to the other of the chambers; and a first device for varying the area of the opening so as to vary the gas flow rate through the opening and between the chambers in use; an ion storage device downstream of said opening, wherein said ion storage device is synchronised with said opening such that ions are transmitted through said opening into said ion storage device when the opening has a large area and ions are prevented from being transmitted through said opening into said ion storage device when the opening has a relatively smaller area or is closed.