Abstract: An apparatus and process in which a particle beam is used to introduce a pattern into an energy sensitive material is disclosed. A coil assembly is used to selectively control both the orientation of the particle beam relative to the substrate on which the energy sensitive material is applied and the magnification or demagnification of the image in the particle beam. The coil assembly comprises at least two coils. The particle beam is projected through the coil assembly. The coil assembly is used to rotate the particle beam to compensate for an observed difference between the actual substrate orientation and the desired substrate orientation. The coils in the coil assembly are excited so that the desired rotation is introduced into the particle beam by the cumulative effects of the magnetic fields generated by the excited coils in the coil assembly.