This shows the path of ions as they travel through a simulated Einzel lens. The ion mass is 200kDa accelerated to 40kV, the middle plate potential is at 200V and the plate size is 1m – these are very large settings used to show the focusing effect more easily and are not practical settings.
Wikiezz
CC BY-SA 3.0
<a class="external free" href="https://en.wikipedia.org/wiki/Image:Einzel_lens_ions.png">http://en.wikipedia.org/wiki/Image:Einzel_lens_ions.png</a>