The Tune window tuning controls B-31
Extraction Voltage This is the high voltage applied to the extraction
rods. Normally the extraction voltage is 12000 V.
The voltage and leakage current are shown as
readbacks. The voltage should be increased from
zero to 12000 V manually in increments of 2000 V.
Tip: If excessive current leakage is seen, the rods
should be cleaned.
Current Leakage If the value rises above a steady value of 10 µA,
there is an excessive leakage of the extraction
voltage to the ground. This indicates that the
source is dirty and requires cleaning.
See also: Cleaning the complete outer source on
page 10-37.
Beam Steering The beam steering is a voltage added to one side of
Focus 3 lens and taken off the other side of Focus 3
lens. This has the effect of steering the beam to the
left or right.
The readback for one side of the Focus 3 lens is
shown next to Beam Steering and the other side of
the Focus 3 lens is shown next to Focus 3, as
shown in the following figure:
Focus 1 Voltage on the first focusing lens.
Focus 2 Voltage on the second focusing lens.
Focus 3 Voltage on the third focusing lens.
FI Tune tab parameters: (Continued)
Parameter Description
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