Patent ID: 8723117

Claim:
A secondary charged particle detection device for detection of a signal beam, comprising: a detector arrangement having at least two detection elements with active detection areas, wherein the active detection areas are separated by a gap; and a particle optics configured for separating the signal beam into a first portion of the signal beam and into at least one second portion of the signal beam, and configured for focusing the first portion of the signal beam and the at least one second portion of the signal beam, wherein the particle optics comprises an aperture plate having at least one first aperture opening in the aperture plate, and at least one second aperture opening in the aperture plate, wherein the at least one second aperture opening is at least one second radially outer aperture opening, and wherein the aperture plate is configured to be biased to one potential surrounding the at least one first aperture opening and the at least one second aperture opening.