Electron induced dissociation devices and methods

Abstract

Pole electrodes () are disclosed for use in an ion reaction apparatus, e.g., an electron induced dissociation cell, to reduce fouling due to polymer build-up and increase the useful lifetime of such electrodes. To reduce fouling, the novel pole electrode designs include a X-shaped aperture () in lieu of the conventional central circular aperture. The pole electrodes are particularly useful in systems having a plurality of branched electrodes () defining a first axis for controlled passage of charged ions and a transverse axis for passage of an electron beam. The pole electrodes are adapted for disposition between an electron source and the branched electrodes to provide an aperture for passage of an electron beam while also impeding escape of ions and reaction products from the apparatus. The X-shaped aperture eliminates or reduces the portion of the pole electrode surface that is most prone to fouling by polymeric build-up.