摘要 |
A lens arrangement (30) for the focusing of a beam of electrically charged particles (24) in the beam path of imaging systems, more particularly in mass spectrometers (10), is indicated, the lens arrangement (30) being connected to an electrical voltage supply. The lens arrangement (30) is situated at the location or in the vicinity of the intermediate image (29) produced by the imaging system, and consists of a plurality of plates (32 to 35) disposed in succession, with aligned transmission apertures (38 to 41), the plates being connected to adjustable electrical voltages.
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