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MULTI-HEARTH ELECTRON BEAM SOURCE ～EGO-４０M～
NOTE
1.
Make functional check of the flow switch in the following way before starting the coater.
Close the cooling water valve temporarily to check that the GUN WATER indicator goes
out. Then slowly open the valve to feed water and check that the indicator lights when
the flow rate exceeds the necessary minimum value mentioned in the EB Gun instruction
manual. If the flow switch does not operate properly, adjust the operating point.
2.
The life of the insulator and filament largely depends on the operating conditions of the EB
Gun. This section describes the frequency for checking the insulator and filament so that
the life expectancy under user's operating conditions can be known.
3.
The filament lead, made of copper, tends to be worn by ionized gas particles in sputtering. A
worn lead may be heated and broken if the EB Gun is operated at high power. Loose
connection causes an unstable filament current because of the contact resistance and will
result in an unstable beam current. In that event, the connection will be heated. The
lead is subject to local sputtering. Replace it when the thickness of the sputtered portion
has become 80
4.
If the lead of the X-axis or Y-axis for the deflecting coil is within 20 mm from the filament
lead, discharge will take place between the two wires and may break down the magnet
control circuit. Make sure the lead is not in a state susceptible to short with ground or to
breakage at the joint with the deflecting coil feedthrough or terminal. Use care especially
after change of filament or cleaning of the crucible area.
5.
The high voltage feedthrough is heated with heat from the EB Gun. This temperature cyclic
makes screws easily loosened and periodical retightening necessary.
6.
The emitter assembly gets very hot during operation. The temperature cycle tends to
loosen screws and the screws must be retightened periodically.
7.
Imperfect grounding can be very dangerous. Check the connections of the ground cable
and avoid use of an unnecessarily long ground cable. For grounding requirements, see the
E/B gun power supply instruction manual.
8.
It is recommended to use distilled water for cooling maintain cooling efficiency. Generally,
city water or well water can be used as it is, but its quality must be less than 100 ppm (hard
water of which salts contents in one liter are 100 mg as converted to calcium carbonate).
Water of poor quality tends to deposit fur on the inside wall of the crucible water path, not
only deteriorating heat conductance and lowering the cooling effect, but also melting the
crucible locally and perforating it.
9.
The multi-hearth type EB Gun uses an O-ring for the shaft seal to seal water and vacuum.
To the O-ring is applied vacuum grease as lubricant, but there can be a leak due to
shortage of grease or plastic deformation of the O-ring even within the warranty period. It
is recommended to change the O-ring and apply grease to the shaft seal area once every
six months for caution's sake.
of the initial size.
36
６．MAINTENANCE
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