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6 6 . . 6 6 . . 3 3 L L o o w w e e r r C C o o l l u u m m n n
1. Anode
2. Ion trap
3. Drift tube
4. Astigmatism lenses
5. Focus lens
6. Deflection lenses
1. Ground fingers (3 pcs)
2. Column protection foil
3. Metallisation cone
4. Cone holder ring
58
The anode (1) acts as a ground point and the ac-
celeration voltage is applied between the grid cup
and the anode.
To protect the cathode from the melt process an
ion trap (2) is located inside the anode.
The drift tube (3) shields the electron beam and
acts as a pressure reducer since the top compart-
ment requires a much lower vacuum level than the
build chamber.
A set of magnetic lenses shapes and controls the
beam.
• Astigmatism 1+2
• Focus
• Deflection X+Y
The column is cooled by air to keep critical parts at
normal temperature during operation.
The magnetic lenses are positioned around a ce-
ramic tube, the inside of which is covered with a
thin metal foil. The purpose of the foil is to prevent
charge buildup which would disturb the beam, and
simplify removal of metallization.
The foil is divided into two parts:
• Column protection foil
• Metallisation cone
The column protection foil is held in place and
grounded via three "fingers" (1) in the top while the
metallisation cone is held in place by a cone holder
ring.
02
OM-710430
en-GB
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