A sequential radial mirror analyzer (RMA) (100) for facilitating rotationally symmetric detection of charged particles caused by a charged beam incident on a specimen (112) is disclosed. The RMA comprises a 0V equipotential exit grid (116), and a plurality of electrodes (119, 120a, 120b, 120c) electrically configured to generate corresponding electrostatic fields for deflecting at least some of the charged particles of a single energy level to exit through the exit grid (116) to form a second-order focal point on a detector (106). The second-order focal point is associated with the single energy level, and the detector (106) is disposed external to the corresponding electrostatic fields. A related method is also disclosed.