LASER DESORPTION MASS SPECTROMETER WITH UNIFORM ILLUMINATION OF THE SAMPLE

摘要

Systems and methods for rastering a series of illumination pulses across the surface of a sample under investigation in a mass spectrometer system so as to create a two dimensional illumination pattern (raster pattern) on the sample. A probe interface that engages a probe is configured to translate the probe along a first direction, and a pulse deflection mechanism is configured to vary the pulse-probe intersect position along a second direction. A control system, implementing a rastering algorithm, provides control signals to the pulse deflection mechanism to adjust the pulse path and the probe translation mechanism to adjust the probe position so that each illumination pulse impinges on one of a plurality of addressable locations on the sample. The resulting raster pattern may cover the entire sample or one or more portions of the sample, depending on the spot size and the displacement distances for each pulse along the first and second directions. Ions desorbed from the sample by each pulse are detected, and a corresponding series of spectra are generated for each of the series of pulses. The spectrum resulting from each pulse may be combined with others to form a combined spectrum for the portion of the sample illuminated by the raster pattern.