Patent ID: 6525314
Filing Date: 2003-02-25
Classification: H01J

Abstract:
A mass spectrometer comprising:an ion source for producing ions, each ion having a mass to charge ratio; an ion filter for selectively passing ions according to mass to charge ratio, the ion filter coupled to receive ions from the ion source; an ion deflector for deflecting ions through a first angle, the ion deflector coupled to receive ions from the ion filter; a collision cell for fragmenting ions to produce fragments, the collision cell coupled to receive ions from the ion deflector; and an ion detector coupled to receive fragments from the collision cell; a fragment deflector for deflecting ions through a second angle, the fragment deflector coupled to receive fragments from the collision cell; and a fragment filter for selectively passing fragments according to mass to charge ratio, the fragment filter coupled to receive fragments from the fragment deflector; wherein the ion detector is coupled to receive fragments from the collision cell via the fragment deflector and the fragment filter; wherein the collision cell includes a gas enclosure defining an ion entry aperture and a fragment exit aperture; the mass spectrometer further comprising a gas removal ring for removing gas from a region proximate to an aperture of the gas enclosure.