
354 Compact Plasma and Focused Ion Beams
positions along the beam axis after the last electrode (L
3
). The intercepted
beam current and transmitted beam current collected by the Faraday cup
are measured using the current meters. Wire methods use a 20 μm Tungsten
wire to intercept the beam with the same 1 μm precision linear motion, and
the beam current through the wire is measured. The speed of motion of the
motorized linear feed-through can be varied in the range of 10–100 μm/s,
and the beam current from the knife edge and Faraday cup are acquired in
the computer using LabVIEW with a precision of 10 data points per second.
Since the linear feed- ...