Embodiments of the invention describe methods and apparatus for assigning
a beam intensity profile to a gas cluster ion beam and processing
workpieces using a gas cluster ion beam. One embodiment includes
generating a gas cluster ion beam in a gas cluster ion beam processing
apparatus, collecting parametric data relating to the spatial intensity
of the gas cluster ion beam, and generating a beam intensity profile
describing the spatial intensity of the gas cluster ion beam by fitting a
mathematical functional shape to the parametric data. Another embodiment
describes a method for processing a workpiece using a gas cluster ion
beam.