Patent ID: 8796638

Claim:
A charged particle lens assembly comprising: a central region comprising: a first hollow body defining a first exterior end, a first interior end and a first axis extending from the first exterior end to the first interior end along a centerline, wherein the first hollow body is substantially linear along the first axis and the first hollow body has a first aspect ratio of between 1.3 and 1.6 defined by a longitudinal length divided by a diameter of the first exterior end, the first interior end, or both; a second hollow body defining a second interior end positioned relative to the first interior end, a second exterior end and a second axis extending from the second interior end to the second exterior end and aligned with the first axis, wherein the second hollow body is substantially linear along the second axis and the second hollow body has a second aspect ratio of between 1.3 and 1.6 defined by a longitudinal length divided by a diameter of the second interior end, the second exterior end, or both; and an interior aperture between the first interior end of the first hollow body and the second interior end of the second hollow body and spaced from the first axis and the second axis; a first electrode assembly positioned relative to the first exterior end of the first hollow body and defining a first aperture spaced from the first axis for receiving an incident beam of charged particles; and a second electrode assembly positioned relative to the second exterior end of the second hollow body and defining a second aperture spaced from the second axis for passing charged particles out of the lens assembly, the central region configured to, when a first electric potential is applied to the first hollow body and a second electric potential is applied to the second hollow body, direct a supply of charged particles incident from the first aperture through the first hollow body towards the interior aperture and from the interior aperture towards the second aperture for exiting the assembly.