having charged particle optical column 102 with an electron source 115 beam optics 135 a magnetic immersion lens 104 the optical column 102 may be controlled by electronics 136 referred to herein as a beam driver the beam driver 136 may control the electron source 115 beam optics 135 and immersion lens 104 in this example the beam optics 135 extract electrons from the source 115 and form them into a primary beam that travels in the direction of the target 101 the immersion lens 104 focuses the primary beam into a narrow spot at the surface of the target electrons from the electron beam column 102 are focused onto a target surface 101 which may be an integrated circuit wafer or a test wafer the target 101 is supported by a stage 118 the electrons may be scanned across the surface of the target 101 e g by magnet deflecting fields provided by one or more scanning coils or electrostatic deflector plates 106 in some implementations the beam scanner driver 108 may provide current to deflector coils 106 via a beam scanner driver 108 in other implementations the beam scanner driver 108 may apply voltages to electrostatic deflector plates to scan the electron beam across the target 101 alternatively the stage 118 may include a stage scanning mechanism 111 and stage scanner driver 119 configured to move the target along x y plane parallel to the surface of the target 101 in one or more directions relative to the optical column 102 in some implementations the stage scanning mechanism 111 and stage scanner driver 119 may move the stage in one direction e g the.