Patent ID: 6744041
Filing Date: 2004-06-01
Classification: H01J

Abstract:
Apparatus for the collection and focusing of gas-phase ions or particles at or near atmospheric pressure, the apparatus comprising:a. dispersive source of ions; b. a conductive high transmission surface populated with a plurality of holes through which said ions pass unobstructed on the way to a collector target, aperture, or tube; said high transmission surface having a topside and an underside, said high transmission surface being supplied with an attracting electric potential by connection to a voltage supply, and generating an electrostatic field between said source of ions and said topside of said high transmission surface; said high transmission surface also being shaped to affect high focusing fields on the focusing side, underside, of said high transmission surface, whereby said electrostatic field at said underside of said high transmission surface is greater than said electrostatic field at said topside of said high transmission surface; c. a target surface for receiving ions or transmitting focused ions through opening of target aperture, or tube in said target surface; said target surface held at a second ion-attracting and higher strength electric potential by connection to said voltage supply, and generating an electrostatic field between said underside of said high transmission surface and said opening of said target aperture or tube which has electrostatic field lines that are concentrated on a relatively reduced cross-sectional area of said target surface, said opening of said target aperture, or opening of said tube; d. an inner field-shaping electrode for focusing ions exiting the underside of said high transmission surface whereby approximately all said ions are focused toward said reduced cross-sectional area on said target surface.