| 摘要 |
<p>A lens system 1 for a plurality of charged particle beams comprises a lens body 10 with a first pole piece 12, a second pole piece 14 and a plurality of lens openings 16 for the respective charged particle beams; a common excitation coil 20 arranged around the plurality of lens openings 16 for providing a respective first magnetic flux to the lens openings; and a compensation coil 30 arranged between the lens openings 16 for providing a respective second magnetic flux to at least some of the lens openings so as to compensate for an asymmetry of the first magnetic flux.</p> |
