Patent ID: 7399119

Claim:
A method for measuring an alignment of a detector, said method comprising.; positioning a collimator having movable cams and collimating a radiation beam; sweeping edges of the collimated radiation beam across the first cell and the second cell of the detector by successively moving the cams in a plurality of discrete positions; generating, by the first cell, a first signal curve as the collimated radiation beam is swept across the first cell; generating, by the second cell, a second signal curve as the collimated radiation beam is swept across the second cell; determining, based on the first and second signal curves, positions of the cams at which the first and second signal curves measure the same signal intensity; and determining, by a processor, the alignment of the detector with respect to the collimated radiation beam, said determining the alignment is based on a plurality of signals from the first cell of the detector and the second cell of the detector, and said determining the alignment is independent of a shape of the collimated radiation beam.