EFFECTS OF GAUSSIAN-BEAM SIZE ON DIFFRACTION MEASUREMENT ERRORS

A numerical simulation has been performed for the diffraction of a gau ssian beam at a wire in the Fraunhofer approximation. The wire is symm etrically disposed with respect to the beam axis in the calculations o n the shifts in the diffraction minima, while an unsymmetrical positio n has been used in calculating the diffraction pattern, which is chara cterized by change in the minima and maxima. Conditions are evaluated under which one can use the homogeneous-beam approximation in diffract ion measurements.