Patent ID: 6762405
Filing Date: 2004-07-13
Classification: H01J

Abstract:
A matrix-assisted laser desorption ionization system comprising:a) a sample receiving chamber for receiving one or more samples; b) a mass spectrometer for analyzing the samples in said chamber; c) a UV laser for providing a laser beam along a first beam path that does not intersect said sample; d) a beam expander located along said first beam path for increasing the spot size of said laser beam and directing said laser beam along a second beam path that does not intersect said sample; e) a focusing system located along said second beam path for focusing said laser beam through a predetermined range of spot sizes; said laser beam incidenting on the approximate optical center of said focusing system; f) a high reflecting mirror in optical communication with said focusing system for reflecting said focused beam on a third beam path that intersects said sample at a predetermined strike point and at a preselected spot size; g) said focusing system being movable along said second beam path so that the spot size of said beam point can be varied without substantial change of said strike point.