The Lund Nuclear Microprobe sub-micron set-up. Part I: Ion optics calculation

The conclusion from the calculations was that to obtain the smallest possible beam, the two-stage focusing system should be used. Such a focusing system (a doublet at each stage) has been chosen for the new sub-micron set-up at the Lund NMP laboratory. The first stage focuses the beam in an intermediate chamber, which has a high-resolution optical viewing system facilitating more control over the beam spot. This real image of the first stage is then used as a virtual object for the second stage.